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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-30 09:22:00 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-30 09:22:00 -0700 |
| commit | 034dd340b08be1f2f0477ad16131d609f9dbd53c (patch) | |
| tree | 2536f4b2d7893ccd916b5abdf3c454ad6edc03c2 /Documentation/driver-api/media | |
| download | linux-stable-034dd340b08be1f2f0477ad16131d609f9dbd53c.tar.gz linux-stable-034dd340b08be1f2f0477ad16131d609f9dbd53c.zip | |
Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted
Pull tracing fixes from Steven Rostedt:
- Fix error output of boot instance creation failure
Currently if a boot instance creation fails, instead of printing out
the name of the instance that failed, it prints "(null)". That is
because it prints "cur_str" that had already been processed by
strsep(). Print the saved name instead.
While at it, print the error code of the failure.
- Fix use-after-free for same named historgrams
Histograms can be named so that they can be used in multiple events.
But if the named histogram has a variable attached, the second event
that uses the named histogram which duplicates it and needs to free
the original after duplication leaves the old variable in place and
still visible. If another histogram uses than variable, it will use
the stale one which will try to reference the freed duplicate
histogram and crash the kernel.
Free the duplicate variables along with the duplicated histogram
data.
- Check return value of kthread_run() in event self test
The events self tests uses a kthread for testing but does not check
if it succeeded in creating a kthread. If the kthread creation were
to fail, the code will still try to call kthread_stop() on the error
returned.
- Fix race between reading trace_pipe and updating subbuffer size
If a user is reading the trace_pipe file at the same time they update
the ring buffer sub-buffer size, can cause the trace_pipe read to
read stale data. Add trace_access_lock() around updating the ring
buffer sub-buffer size.
- Fix eventfs_inode on failure path in creation of the events directory
In the creation of the "events" directory, if after allocating the
eventfs_inode a failure is detected, it calls cleanup_ei() which
calls free_ei(). The free_ei() will test if eventfs_inode being freed
has no children. It is a bug if it does. But on the failure case of
the creation of the "events" directory, the children lists have not
yet been initialized and the free will trigger a warning because
list_empty() on an uninitialized list returns false.
Move the initialization into init_ei() where it makes more sense and
makes sure that a created eventfs_inode has its lists initialized
upon creation.
- Check return value of kthread_run() in ftrace direct sample code
The sample code that shows how to use the ftrace direct calls does
not test the return of kthread_run() to see if it succeeds. Return a
failure if the kthread_run() doesn't succeed.
- Clear user events state on fork in case of alloc failure
On fork, the child gets a pointer to the parent's user events state.
It makes a copy of it then updates the child's pointer to it. But if
the allocation fails, the duplication function leaves the child with
a pointer to its parent's descriptor. When the child cleans up its
data, it will free the parent's descriptor while the parent is still
using it.
In the duplication function, set the child's user_event_mm to NULL
before testing if the allocation succeeded, and when it exits it will
not free the parent's descriptor.
- Fix retry exhaustion in simple ring buffer reader swap
simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
post-decrements it only after a failed link replacement. On the final
attempt, a successful replacement leaves retry at zero, while a
failed replacement leaves it at -1.
But the check for success expects the retry value to be non-zero and
exits with an error on zero. This is the opposite result. Fix it.
- Fail nicely when the remote swap_reader_page() returns an error
Currently, if the swap_reader_page() of a remote buffer fails, it
triggers a WARN_ON_ONCE() and continues normally. Instead, have it
exit with an error and a pr_warn() print instead of a full WARNING.
* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Stop remote reader update when page swap fails
tracing: Fix retry exhaustion in simple ring buffer reader swap
tracing/user_events: Clear copied tracing state before fork duplication
samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
eventfs: Initialize ei->children and ei->list in init_ei()
tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
tracing: Fix crash passing ERR_PTR to kthread_stop()
tracing: Fix use-after-free with same-name named triggers
tracing: Fix logged instance name on creation failure
Diffstat (limited to 'Documentation/driver-api/media')
59 files changed, 13571 insertions, 0 deletions
diff --git a/Documentation/driver-api/media/camera-sensor.rst b/Documentation/driver-api/media/camera-sensor.rst new file mode 100644 index 000000000..c8552f70f --- /dev/null +++ b/Documentation/driver-api/media/camera-sensor.rst @@ -0,0 +1,158 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. _media_writing_camera_sensor_drivers: + +Writing camera sensor drivers +============================= + +This document covers the in-kernel APIs only. For the best practices on +userspace API implementation in camera sensor drivers, please see +:ref:`media_using_camera_sensor_drivers`. + +CSI-2, parallel and BT.656 buses +-------------------------------- + +Please see :ref:`transmitter-receiver`. + +Handling clocks +--------------- + +Camera sensors have an internal clock tree including a PLL and a number of +divisors. The clock tree is generally configured by the driver based on a few +input parameters that are specific to the hardware: the external clock frequency +and the link frequency. The two parameters generally are obtained from system +firmware. **No other frequencies should be used in any circumstances.** + +The reason why the clock frequencies are so important is that the clock signals +come out of the SoC, and in many cases a specific frequency is designed to be +used in the system. Using another frequency may cause harmful effects +elsewhere. Therefore only the pre-determined frequencies are configurable by the +user. + +The external clock frequency shall be retrieved by obtaining the external clock +using the ``devm_v4l2_sensor_clk_get()`` helper function, and then getting its +frequency with ``clk_get_rate()``. Usage of the helper function guarantees +correct behaviour regardless of whether the sensor is integrated in a DT-based +or ACPI-based system. + +ACPI +~~~~ + +ACPI-based systems typically don't register the sensor external clock with the +kernel, but specify the external clock frequency in the ``clock-frequency`` +_DSD property. The ``devm_v4l2_sensor_clk_get()`` helper creates and returns a +fixed clock set at that rate. + +Devicetree +~~~~~~~~~~ + +Devicetree-based systems declare the sensor external clock in the device tree +and reference it from the sensor node. The preferred way to select the external +clock frequency is to use the ``assigned-clocks``, ``assigned-clock-parents`` +and ``assigned-clock-rates`` properties in the sensor node to set the clock +rate. See the `clock device tree bindings +<https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/clock/clock.yaml>`_ +for more information. The ``devm_v4l2_sensor_clk_get()`` helper retrieves and +returns that clock. + +This approach has the drawback that there's no guarantee that the frequency +hasn't been modified directly or indirectly by another driver, or supported by +the board's clock tree to begin with. Changes to the Common Clock Framework API +are required to ensure reliability. + +Power management +---------------- + +Camera sensors are used in conjunction with other devices to form a camera +pipeline. They must obey the rules listed herein to ensure coherent power +management over the pipeline. + +Camera sensor drivers are responsible for controlling the power state of the +device they otherwise control as well. They shall use runtime PM to manage +power states. Runtime PM shall be enabled at probe time and disabled at remove +time. Drivers should enable runtime PM autosuspend. Also see +:ref:`async sub-device registration <media-registering-async-subdevs>`. + +The runtime PM handlers shall handle clocks, regulators, GPIOs, and other +system resources required to power the sensor up and down. For drivers that +don't use any of those resources (such as drivers that support ACPI systems +only), the runtime PM handlers may be left unimplemented. + +In general, the device shall be powered on at least when its registers are +being accessed and when it is streaming. Drivers should use +``pm_runtime_resume_and_get()`` when starting streaming and +``pm_runtime_put()`` or ``pm_runtime_put_autosuspend()`` when stopping +streaming. They may power the device up at probe time (for example to read +identification registers), but should not keep it powered unconditionally after +probe. + +At system suspend time, the whole camera pipeline must stop streaming, and +restart when the system is resumed. This requires coordination between the +camera sensor and the rest of the camera pipeline. Bridge drivers are +responsible for this coordination, and instruct camera sensors to stop and +restart streaming by calling the appropriate subdev operations +(``.enable_streams()`` or ``.disable_streams()``). Camera sensor drivers shall +therefore **not** keep track of the streaming state to stop streaming in the PM +suspend handler and restart it in the resume handler. Drivers should in general +not implement the system PM handlers. + +Camera sensor drivers shall **not** implement the subdev ``.s_power()`` +operation, as it is deprecated. While this operation is implemented in some +existing drivers as they predate the deprecation, new drivers shall use runtime +PM instead. If you feel you need to begin calling ``.s_power()`` from an ISP or +a bridge driver, instead add runtime PM support to the sensor driver you are +using and drop its ``.s_power()`` handler. + +Please also see :ref:`examples <media-camera-sensor-examples>`. + +Control framework +~~~~~~~~~~~~~~~~~ + +``v4l2_ctrl_handler_setup()`` function may not be used in the device's runtime +PM ``runtime_resume`` callback, as it has no way to figure out the power state +of the device. This is because the power state of the device is only changed +after the power state transition has taken place. The ``s_ctrl`` callback can be +used to obtain device's power state after the power state transition: + +.. c:function:: int pm_runtime_get_if_active(struct device *dev); + +The function returns a non-zero value if it succeeded getting the power count or +runtime PM was disabled, in either of which cases the driver may proceed to +access the device. + +Rotation, orientation and flipping +---------------------------------- + +Use ``v4l2_fwnode_device_parse()`` to obtain rotation and orientation +information from system firmware and ``v4l2_ctrl_new_fwnode_properties()`` to +register the appropriate controls. + +.. _media-camera-sensor-examples: + +Example drivers +--------------- + +Features implemented by sensor drivers vary, and depending on the set of +supported features and other qualities, particular sensor drivers better serve +the purpose of an example. The following drivers are known to be good examples: + +.. flat-table:: Example sensor drivers + :header-rows: 0 + :widths: 1 1 1 2 + + * - Driver name + - File(s) + - Driver type + - Example topic + * - CCS + - ``drivers/media/i2c/ccs/`` + - Freely configurable + - Power management (ACPI and DT), UAPI + * - imx219 + - ``drivers/media/i2c/imx219.c`` + - Register list based + - Power management (DT), UAPI, mode selection + * - imx319 + - ``drivers/media/i2c/imx319.c`` + - Register list based + - Power management (ACPI and DT) diff --git a/Documentation/driver-api/media/cec-core.rst b/Documentation/driver-api/media/cec-core.rst new file mode 100644 index 000000000..f1ffdec38 --- /dev/null +++ b/Documentation/driver-api/media/cec-core.rst @@ -0,0 +1,502 @@ +.. SPDX-License-Identifier: GPL-2.0 + +CEC Kernel Support +================== + +The CEC framework provides a unified kernel interface for use with HDMI CEC +hardware. It is designed to handle a multiple types of hardware (receivers, +transmitters, USB dongles). The framework also gives the option to decide +what to do in the kernel driver and what should be handled by userspace +applications. In addition it integrates the remote control passthrough +feature into the kernel's remote control framework. + + +The CEC Protocol +---------------- + +The CEC protocol enables consumer electronic devices to communicate with each +other through the HDMI connection. The protocol uses logical addresses in the +communication. The logical address is strictly connected with the functionality +provided by the device. The TV acting as the communication hub is always +assigned address 0. The physical address is determined by the physical +connection between devices. + +The CEC framework described here is up to date with the CEC 2.0 specification. +It is documented in the HDMI 1.4 specification with the new 2.0 bits documented +in the HDMI 2.0 specification. But for most of the features the freely available +HDMI 1.3a specification is sufficient: + +https://www.hdmi.org/spec/index + + +CEC Adapter Interface +--------------------- + +The struct cec_adapter represents the CEC adapter hardware. It is created by +calling cec_allocate_adapter() and deleted by calling cec_delete_adapter(): + +.. c:function:: + struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops, \ + void *priv, const char *name, \ + u32 caps, u8 available_las); + +.. c:function:: + void cec_delete_adapter(struct cec_adapter *adap); + +To create an adapter you need to pass the following information: + +ops: + adapter operations which are called by the CEC framework and that you + have to implement. + +priv: + will be stored in adap->priv and can be used by the adapter ops. + Use cec_get_drvdata(adap) to get the priv pointer. + +name: + the name of the CEC adapter. Note: this name will be copied. + +caps: + capabilities of the CEC adapter. These capabilities determine the + capabilities of the hardware and which parts are to be handled + by userspace and which parts are handled by kernelspace. The + capabilities are returned by CEC_ADAP_G_CAPS. + +available_las: + the number of simultaneous logical addresses that this + adapter can handle. Must be 1 <= available_las <= CEC_MAX_LOG_ADDRS. + +To obtain the priv pointer use this helper function: + +.. c:function:: + void *cec_get_drvdata(const struct cec_adapter *adap); + +To register the /dev/cecX device node and the remote control device (if +CEC_CAP_RC is set) you call: + +.. c:function:: + int cec_register_adapter(struct cec_adapter *adap, \ + struct device *parent); + +where parent is the parent device. + +To unregister the devices call: + +.. c:function:: + void cec_unregister_adapter(struct cec_adapter *adap); + +Note: if cec_register_adapter() fails, then call cec_delete_adapter() to +clean up. But if cec_register_adapter() succeeded, then only call +cec_unregister_adapter() to clean up, never cec_delete_adapter(). The +unregister function will delete the adapter automatically once the last user +of that /dev/cecX device has closed its file handle. + + +Implementing the Low-Level CEC Adapter +-------------------------------------- + +The following low-level adapter operations have to be implemented in +your driver: + +.. c:struct:: cec_adap_ops + +.. code-block:: none + + struct cec_adap_ops + { + /* Low-level callbacks */ + int (*adap_enable)(struct cec_adapter *adap, bool enable); + int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable); + int (*adap_monitor_pin_enable)(struct cec_adapter *adap, bool enable); + int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr); + void (*adap_unconfigured)(struct cec_adapter *adap); + int (*adap_transmit)(struct cec_adapter *adap, u8 attempts, + u32 signal_free_time, struct cec_msg *msg); + void (*adap_nb_transmit_canceled)(struct cec_adapter *adap, + const struct cec_msg *msg); + void (*adap_status)(struct cec_adapter *adap, struct seq_file *file); + void (*adap_free)(struct cec_adapter *adap); + + /* Error injection callbacks */ + ... + + /* High-level callback */ + ... + }; + +These low-level ops deal with various aspects of controlling the CEC adapter +hardware. They are all called with the mutex adap->lock held. + + +To enable/disable the hardware:: + + int (*adap_enable)(struct cec_adapter *adap, bool enable); + +This callback enables or disables the CEC hardware. Enabling the CEC hardware +means powering it up in a state where no logical addresses are claimed. The +physical address will always be valid if CEC_CAP_NEEDS_HPD is set. If that +capability is not set, then the physical address can change while the CEC +hardware is enabled. CEC drivers should not set CEC_CAP_NEEDS_HPD unless +the hardware design requires that as this will make it impossible to wake +up displays that pull the HPD low when in standby mode. The initial +state of the CEC adapter after calling cec_allocate_adapter() is disabled. + +Note that adap_enable must return 0 if enable is false. + + +To enable/disable the 'monitor all' mode:: + + int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable); + +If enabled, then the adapter should be put in a mode to also monitor messages +that are not for us. Not all hardware supports this and this function is only +called if the CEC_CAP_MONITOR_ALL capability is set. This callback is optional +(some hardware may always be in 'monitor all' mode). + +Note that adap_monitor_all_enable must return 0 if enable is false. + + +To enable/disable the 'monitor pin' mode:: + + int (*adap_monitor_pin_enable)(struct cec_adapter *adap, bool enable); + +If enabled, then the adapter should be put in a mode to also monitor CEC pin +changes. Not all hardware supports this and this function is only called if +the CEC_CAP_MONITOR_PIN capability is set. This callback is optional +(some hardware may always be in 'monitor pin' mode). + +Note that adap_monitor_pin_enable must return 0 if enable is false. + + +To program a new logical address:: + + int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr); + +If logical_addr == CEC_LOG_ADDR_INVALID then all programmed logical addresses +are to be erased. Otherwise the given logical address should be programmed. +If the maximum number of available logical addresses is exceeded, then it +should return -ENXIO. Once a logical address is programmed the CEC hardware +can receive directed messages to that address. + +Note that adap_log_addr must return 0 if logical_addr is CEC_LOG_ADDR_INVALID. + + +Called when the adapter is unconfigured:: + + void (*adap_unconfigured)(struct cec_adapter *adap); + +The adapter is unconfigured. If the driver has to take specific actions after +unconfiguration, then that can be done through this optional callback. + + +To transmit a new message:: + + int (*adap_transmit)(struct cec_adapter *adap, u8 attempts, + u32 signal_free_time, struct cec_msg *msg); + +This transmits a new message. The attempts argument is the suggested number of +attempts for the transmit. + +The signal_free_time is the number of data bit periods that the adapter should +wait when the line is free before attempting to send a message. This value +depends on whether this transmit is a retry, a message from a new initiator or +a new message for the same initiator. Most hardware will handle this +automatically, but in some cases this information is needed. + +The CEC_FREE_TIME_TO_USEC macro can be used to convert signal_free_time to +microseconds (one data bit period is 2.4 ms). + + +To pass on the result of a canceled non-blocking transmit:: + + void (*adap_nb_transmit_canceled)(struct cec_adapter *adap, + const struct cec_msg *msg); + +This optional callback can be used to obtain the result of a canceled +non-blocking transmit with sequence number msg->sequence. This is +called if the transmit was aborted, the transmit timed out (i.e. the +hardware never signaled that the transmit finished), or the transmit +was successful, but the wait for the expected reply was either aborted +or it timed out. + + +To log the current CEC hardware status:: + + void (*adap_status)(struct cec_adapter *adap, struct seq_file *file); + +This optional callback can be used to show the status of the CEC hardware. +The status is available through debugfs: cat /sys/kernel/debug/cec/cecX/status + +To free any resources when the adapter is deleted:: + + void (*adap_free)(struct cec_adapter *adap); + +This optional callback can be used to free any resources that might have been +allocated by the driver. It's called from cec_delete_adapter. + + +Your adapter driver will also have to react to events (typically interrupt +driven) by calling into the framework in the following situations: + +When a transmit finished (successfully or otherwise):: + + void cec_transmit_done(struct cec_adapter *adap, u8 status, + u8 arb_lost_cnt, u8 nack_cnt, u8 low_drive_cnt, + u8 error_cnt); + +or:: + + void cec_transmit_attempt_done(struct cec_adapter *adap, u8 status); + +The status can be one of: + +CEC_TX_STATUS_OK: + the transmit was successful. + +CEC_TX_STATUS_ARB_LOST: + arbitration was lost: another CEC initiator + took control of the CEC line and you lost the arbitration. + +CEC_TX_STATUS_NACK: + the message was nacked (for a directed message) or + acked (for a broadcast message). A retransmission is needed. + +CEC_TX_STATUS_LOW_DRIVE: + low drive was detected on the CEC bus. This indicates that + a follower detected an error on the bus and requested a + retransmission. + +CEC_TX_STATUS_ERROR: + some unspecified error occurred: this can be one of ARB_LOST + or LOW_DRIVE if the hardware cannot differentiate or something + else entirely. Some hardware only supports OK and FAIL as the + result of a transmit, i.e. there is no way to differentiate + between the different possible errors. In that case map FAIL + to CEC_TX_STATUS_NACK and not to CEC_TX_STATUS_ERROR. + +CEC_TX_STATUS_MAX_RETRIES: + could not transmit the message after trying multiple times. + Should only be set by the driver if it has hardware support for + retrying messages. If set, then the framework assumes that it + doesn't have to make another attempt to transmit the message + since the hardware did that already. + +The hardware must be able to differentiate between OK, NACK and 'something +else'. + +The \*_cnt arguments are the number of error conditions that were seen. +This may be 0 if no information is available. Drivers that do not support +hardware retry can just set the counter corresponding to the transmit error +to 1, if the hardware does support retry then either set these counters to +0 if the hardware provides no feedback of which errors occurred and how many +times, or fill in the correct values as reported by the hardware. + +Be aware that calling these functions can immediately start a new transmit +if there is one pending in the queue. So make sure that the hardware is in +a state where new transmits can be started *before* calling these functions. + +The cec_transmit_attempt_done() function is a helper for cases where the +hardware never retries, so the transmit is always for just a single +attempt. It will call cec_transmit_done() in turn, filling in 1 for the +count argument corresponding to the status. Or all 0 if the status was OK. + +When a CEC message was received: + +.. c:function:: + void cec_received_msg(struct cec_adapter *adap, struct cec_msg *msg); + +Speaks for itself. + +Implementing the interrupt handler +---------------------------------- + +Typically the CEC hardware provides interrupts that signal when a transmit +finished and whether it was successful or not, and it provides and interrupt +when a CEC message was received. + +The CEC driver should always process the transmit interrupts first before +handling the receive interrupt. The framework expects to see the cec_transmit_done +call before the cec_received_msg call, otherwise it can get confused if the +received message was in reply to the transmitted message. + +Optional: Implementing Error Injection Support +---------------------------------------------- + +If the CEC adapter supports Error Injection functionality, then that can +be exposed through the Error Injection callbacks: + +.. code-block:: none + + struct cec_adap_ops { + /* Low-level callbacks */ + ... + + /* Error injection callbacks */ + int (*error_inj_show)(struct cec_adapter *adap, struct seq_file *sf); + bool (*error_inj_parse_line)(struct cec_adapter *adap, char *line); + + /* High-level CEC message callback */ + ... + }; + +If both callbacks are set, then an ``error-inj`` file will appear in debugfs. +The basic syntax is as follows: + +Leading spaces/tabs are ignored. If the next character is a ``#`` or the end of the +line was reached, then the whole line is ignored. Otherwise a command is expected. + +This basic parsing is done in the CEC Framework. It is up to the driver to decide +what commands to implement. The only requirement is that the command ``clear`` without +any arguments must be implemented and that it will remove all current error injection +commands. + +This ensures that you can always do ``echo clear >error-inj`` to clear any error +injections without having to know the details of the driver-specific commands. + +Note that the output of ``error-inj`` shall be valid as input to ``error-inj``. +So this must work: + +.. code-block:: none + + $ cat error-inj >einj.txt + $ cat einj.txt >error-inj + +The first callback is called when this file is read and it should show the +current error injection state:: + + int (*error_inj_show)(struct cec_adapter *adap, struct seq_file *sf); + +It is recommended that it starts with a comment block with basic usage +information. It returns 0 for success and an error otherwise. + +The second callback will parse commands written to the ``error-inj`` file:: + + bool (*error_inj_parse_line)(struct cec_adapter *adap, char *line); + +The ``line`` argument points to the start of the command. Any leading +spaces or tabs have already been skipped. It is a single line only (so there +are no embedded newlines) and it is 0-terminated. The callback is free to +modify the contents of the buffer. It is only called for lines containing a +command, so this callback is never called for empty lines or comment lines. + +Return true if the command was valid or false if there were syntax errors. + +Implementing the High-Level CEC Adapter +--------------------------------------- + +The low-level operations drive the hardware, the high-level operations are +CEC protocol driven. The high-level callbacks are called without the adap->lock +mutex being held. The following high-level callbacks are available: + +.. code-block:: none + + struct cec_adap_ops { + /* Low-level callbacks */ + ... + + /* Error injection callbacks */ + ... + + /* High-level CEC message callback */ + void (*configured)(struct cec_adapter *adap); + int (*received)(struct cec_adapter *adap, struct cec_msg *msg); + }; + +Called when the adapter is configured:: + + void (*configured)(struct cec_adapter *adap); + +The adapter is fully configured, i.e. all logical addresses have been +successfully claimed. If the driver has to take specific actions after +configuration, then that can be done through this optional callback. + + +The received() callback allows the driver to optionally handle a newly +received CEC message:: + + int (*received)(struct cec_adapter *adap, struct cec_msg *msg); + +If the driver wants to process a CEC message, then it can implement this +callback. If it doesn't want to handle this message, then it should return +-ENOMSG, otherwise the CEC framework assumes it processed this message and +it will not do anything with it. + + +CEC framework functions +----------------------- + +CEC Adapter drivers can call the following CEC framework functions: + +.. c:function:: + int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg, \ + bool block); + +Transmit a CEC message. If block is true, then wait until the message has been +transmitted, otherwise just queue it and return. + +.. c:function:: + void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, bool block); + +Change the physical address. This function will set adap->phys_addr and +send an event if it has changed. If cec_s_log_addrs() has been called and +the physical address has become valid, then the CEC framework will start +claiming the logical addresses. If block is true, then this function won't +return until this process has finished. + +When the physical address is set to a valid value the CEC adapter will +be enabled (see the adap_enable op). When it is set to CEC_PHYS_ADDR_INVALID, +then the CEC adapter will be disabled. If you change a valid physical address +to another valid physical address, then this function will first set the +address to CEC_PHYS_ADDR_INVALID before enabling the new physical address. + +.. c:function:: + void cec_s_phys_addr_from_edid(struct cec_adapter *adap, \ + const struct edid *edid); + +A helper function that extracts the physical address from the edid struct +and calls cec_s_phys_addr() with that address, or CEC_PHYS_ADDR_INVALID +if the EDID did not contain a physical address or edid was a NULL pointer. + +.. c:function:: + int cec_s_log_addrs(struct cec_adapter *adap, \ + struct cec_log_addrs *log_addrs, bool block); + +Claim the CEC logical addresses. Should never be called if CEC_CAP_LOG_ADDRS +is set. If block is true, then wait until the logical addresses have been +claimed, otherwise just queue it and return. To unconfigure all logical +addresses call this function with log_addrs set to NULL or with +log_addrs->num_log_addrs set to 0. The block argument is ignored when +unconfiguring. This function will just return if the physical address is +invalid. Once the physical address becomes valid, then the framework will +attempt to claim these logical addresses. + +CEC Pin framework +----------------- + +Most CEC hardware operates on full CEC messages where the software provides +the message and the hardware handles the low-level CEC protocol. But some +hardware only drives the CEC pin and software has to handle the low-level +CEC protocol. The CEC pin framework was created to handle such devices. + +Note that due to the close-to-realtime requirements it can never be guaranteed +to work 100%. This framework uses highres timers internally, but if a +timer goes off too late by more than 300 microseconds wrong results can +occur. In reality it appears to be fairly reliable. + +One advantage of this low-level implementation is that it can be used as +a cheap CEC analyser, especially if interrupts can be used to detect +CEC pin transitions from low to high or vice versa. + +.. kernel-doc:: include/media/cec-pin.h + +CEC Notifier framework +---------------------- + +Most drm HDMI implementations have an integrated CEC implementation and no +notifier support is needed. But some have independent CEC implementations +that have their own driver. This could be an IP block for an SoC or a +completely separate chip that deals with the CEC pin. For those cases a +drm driver can install a notifier and use the notifier to inform the +CEC driver about changes in the physical address. + +.. kernel-doc:: include/media/cec-notifier.h diff --git a/Documentation/driver-api/media/drivers/bttv-devel.rst b/Documentation/driver-api/media/drivers/bttv-devel.rst new file mode 100644 index 000000000..0885a0456 --- /dev/null +++ b/Documentation/driver-api/media/drivers/bttv-devel.rst @@ -0,0 +1,116 @@ +.. SPDX-License-Identifier: GPL-2.0 + +The bttv driver +=============== + +bttv and sound mini howto +------------------------- + +There are a lot of different bt848/849/878/879 based boards available. +Making video work often is not a big deal, because this is handled +completely by the bt8xx chip, which is common on all boards. But +sound is handled in slightly different ways on each board. + +To handle the grabber boards correctly, there is a array tvcards[] in +bttv-cards.c, which holds the information required for each board. +Sound will work only, if the correct entry is used (for video it often +makes no difference). The bttv driver prints a line to the kernel +log, telling which card type is used. Like this one:: + + bttv0: model: BT848(Hauppauge old) [autodetected] + +You should verify this is correct. If it isn't, you have to pass the +correct board type as insmod argument, ``insmod bttv card=2`` for +example. The file Documentation/admin-guide/media/bttv-cardlist.rst has a list +of valid arguments for card. + +If your card isn't listed there, you might check the source code for +new entries which are not listed yet. If there isn't one for your +card, you can check if one of the existing entries does work for you +(just trial and error...). + +Some boards have an extra processor for sound to do stereo decoding +and other nice features. The msp34xx chips are used by Hauppauge for +example. If your board has one, you might have to load a helper +module like ``msp3400`` to make sound work. If there isn't one for the +chip used on your board: Bad luck. Start writing a new one. Well, +you might want to check the video4linux mailing list archive first... + +Of course you need a correctly installed soundcard unless you have the +speakers connected directly to the grabber board. Hint: check the +mixer settings too. ALSA for example has everything muted by default. + + +How sound works in detail +~~~~~~~~~~~~~~~~~~~~~~~~~ + +Still doesn't work? Looks like some driver hacking is required. +Below is a do-it-yourself description for you. + +The bt8xx chips have 32 general purpose pins, and registers to control +these pins. One register is the output enable register +(``BT848_GPIO_OUT_EN``), it says which pins are actively driven by the +bt848 chip. Another one is the data register (``BT848_GPIO_DATA``), where +you can get/set the status if these pins. They can be used for input +and output. + +Most grabber board vendors use these pins to control an external chip +which does the sound routing. But every board is a little different. +These pins are also used by some companies to drive remote control +receiver chips. Some boards use the i2c bus instead of the gpio pins +to connect the mux chip. + +As mentioned above, there is a array which holds the required +information for each known board. You basically have to create a new +line for your board. The important fields are these two:: + + struct tvcard + { + [ ... ] + u32 gpiomask; + u32 audiomux[6]; /* Tuner, Radio, external, internal, mute, stereo */ + }; + +gpiomask specifies which pins are used to control the audio mux chip. +The corresponding bits in the output enable register +(``BT848_GPIO_OUT_EN``) will be set as these pins must be driven by the +bt848 chip. + +The ``audiomux[]`` array holds the data values for the different inputs +(i.e. which pins must be high/low for tuner/mute/...). This will be +written to the data register (``BT848_GPIO_DATA``) to switch the audio +mux. + + +What you have to do is figure out the correct values for gpiomask and +the audiomux array. If you have Windows and the drivers four your +card installed, you might to check out if you can read these registers +values used by the windows driver. A tool to do this is available +from http://btwincap.sourceforge.net/download.html. + +You might also dig around in the ``*.ini`` files of the Windows applications. +You can have a look at the board to see which of the gpio pins are +connected at all and then start trial-and-error ... + + +Starting with release 0.7.41 bttv has a number of insmod options to +make the gpio debugging easier: + + ================= ============================================== + bttv_gpio=0/1 enable/disable gpio debug messages + gpiomask=n set the gpiomask value + audiomux=i,j,... set the values of the audiomux array + audioall=a set the values of the audiomux array (one + value for all array elements, useful to check + out which effect the particular value has). + ================= ============================================== + +The messages printed with ``bttv_gpio=1`` look like this:: + + bttv0: gpio: en=00000027, out=00000024 in=00ffffd8 [audio: off] + + en = output _en_able register (BT848_GPIO_OUT_EN) + out = _out_put bits of the data register (BT848_GPIO_DATA), + i.e. BT848_GPIO_DATA & BT848_GPIO_OUT_EN + in = _in_put bits of the data register, + i.e. BT848_GPIO_DATA & ~BT848_GPIO_OUT_EN diff --git a/Documentation/driver-api/media/drivers/ccs/ccs-regs.asc b/Documentation/driver-api/media/drivers/ccs/ccs-regs.asc new file mode 100644 index 000000000..bbf9213c3 --- /dev/null +++ b/Documentation/driver-api/media/drivers/ccs/ccs-regs.asc @@ -0,0 +1,1041 @@ +# SPDX-License-Identifier: GPL-2.0-only OR BSD-3-Clause +# Copyright (C) 2019--2020 Intel Corporation + +# register rflags +# - f field LSB MSB rflags +# - e enum value # after a field +# - e enum value [LSB MSB] +# - b bool bit +# - l arg name min max elsize [discontig...] +# +# rflags +# 8, 16, 32 register bits (default is 8) +# v1.1 defined in version 1.1 +# f formula +# float_ireal iReal or IEEE 754; 32 bits +# ireal unsigned iReal + +# general status registers +module_model_id 0x0000 16 +module_revision_number_major 0x0002 8 +frame_count 0x0005 8 +pixel_order 0x0006 8 +- e GRBG 0 +- e RGGB 1 +- e BGGR 2 +- e GBRG 3 +MIPI_CCS_version 0x0007 8 +- e v1_0 0x10 +- e v1_1 0x11 +- f major 4 7 +- f minor 0 3 +data_pedestal 0x0008 16 +module_manufacturer_id 0x000e 16 +module_revision_number_minor 0x0010 8 +module_date_year 0x0012 8 +module_date_month 0x0013 8 +module_date_day 0x0014 8 +module_date_phase 0x0015 8 +- f 0 2 +- e ts 0 +- e es 1 +- e cs 2 +- e mp 3 +sensor_model_id 0x0016 16 +sensor_revision_number 0x0018 8 +sensor_firmware_version 0x001a 8 +serial_number 0x001c 32 +sensor_manufacturer_id 0x0020 16 +sensor_revision_number_16 0x0022 16 + +# frame format description registers +frame_format_model_type 0x0040 8 +- e 2-byte 1 +- e 4-byte 2 +frame_format_model_subtype 0x0041 8 +- f rows 0 3 +- f columns 4 7 +frame_format_descriptor(n) 0x0042 16 f +- l n 0 14 2 +- f pixels 0 11 +- f pcode 12 15 +- e embedded 1 +- e dummy_pixel 2 +- e black_pixel 3 +- e dark_pixel 4 +- e visible_pixel 5 +- e manuf_specific_0 8 +- e manuf_specific_1 9 +- e manuf_specific_2 10 +- e manuf_specific_3 11 +- e manuf_specific_4 12 +- e manuf_specific_5 13 +- e manuf_specific_6 14 +frame_format_descriptor_4(n) 0x0060 32 f +- l n 0 7 4 +- f pixels 0 15 +- f pcode 28 31 +- e embedded 1 +- e dummy_pixel 2 +- e black_pixel 3 +- e dark_pixel 4 +- e visible_pixel 5 +- e manuf_specific_0 8 +- e manuf_specific_1 9 +- e manuf_specific_2 10 +- e manuf_specific_3 11 +- e manuf_specific_4 12 +- e manuf_specific_5 13 +- e manuf_specific_6 14 + +# analog gain description registers +analog_gain_capability 0x0080 16 +- e global 0 +- e alternate_global 2 +analog_gain_code_min 0x0084 16 +analog_gain_code_max 0x0086 16 +analog_gain_code_step 0x0088 16 +analog_gain_type 0x008a 16 +analog_gain_m0 0x008c 16 +analog_gain_c0 0x008e 16 +analog_gain_m1 0x0090 16 +analog_gain_c1 0x0092 16 +analog_linear_gain_min 0x0094 16 v1.1 +analog_linear_gain_max 0x0096 16 v1.1 +analog_linear_gain_step_size 0x0098 16 v1.1 +analog_exponential_gain_min 0x009a 16 v1.1 +analog_exponential_gain_max 0x009c 16 v1.1 +analog_exponential_gain_step_size 0x009e 16 v1.1 + +# data format description registers +data_format_model_type 0x00c0 8 +- e normal 1 +- e extended 2 +data_format_model_subtype 0x00c1 8 +- f rows 0 3 +- f columns 4 7 +data_format_descriptor(n) 0x00c2 16 f +- l n 0 15 2 +- f compressed 0 7 +- f uncompressed 8 15 + +# general set-up registers +mode_select 0x0100 8 +- e software_standby 0 +- e streaming 1 +image_orientation 0x0101 8 +- b horizontal_mirror 0 +- b vertical_flip 1 +software_reset 0x0103 8 +- e off 0 +- e on 1 +grouped_parameter_hold 0x0104 8 +mask_corrupted_frames 0x0105 8 +- e allow 0 +- e mask 1 +fast_standby_ctrl 0x0106 8 +- e complete_frames 0 +- e frame_truncation 1 +CCI_address_ctrl 0x0107 8 +2nd_CCI_if_ctrl 0x0108 8 +- b enable 0 +- b ack 1 +2nd_CCI_address_ctrl 0x0109 8 +CSI_channel_identifier 0x0110 8 +CSI_signaling_mode 0x0111 8 +- e csi_2_dphy 2 +- e csi_2_cphy 3 +CSI_data_format 0x0112 16 +CSI_lane_mode 0x0114 8 +DPCM_Frame_DT 0x011d 8 +Bottom_embedded_data_DT 0x011e 8 +Bottom_embedded_data_VC 0x011f 8 + +gain_mode 0x0120 8 +- e global 0 +- e alternate 1 +ADC_bit_depth 0x0121 8 +emb_data_ctrl 0x0122 v1.1 +- b raw8_packing_for_raw16 0 +- b raw10_packing_for_raw20 1 +- b raw12_packing_for_raw24 2 + +GPIO_TRIG_mode 0x0130 8 +extclk_frequency_mhz 0x0136 16 ireal +temp_sensor_ctrl 0x0138 8 +- b enable 0 +temp_sensor_mode 0x0139 8 +temp_sensor_output 0x013a 8 + +# integration time registers +fine_integration_time 0x0200 16 +coarse_integration_time 0x0202 16 + +# analog gain registers +analog_gain_code_global 0x0204 16 +analog_linear_gain_global 0x0206 16 v1.1 +analog_exponential_gain_global 0x0208 16 v1.1 + +# digital gain registers +digital_gain_global 0x020e 16 + +# hdr control registers +Short_analog_gain_global 0x0216 16 +Short_digital_gain_global 0x0218 16 + +HDR_mode 0x0220 8 +- b enabled 0 +- b separate_analog_gain 1 +- b upscaling 2 +- b reset_sync 3 +- b timing_mode 4 +- b exposure_ctrl_direct 5 +- b separate_digital_gain 6 +HDR_resolution_reduction 0x0221 8 +- f row 0 3 +- f column 4 7 +Exposure_ratio 0x0222 8 +HDR_internal_bit_depth 0x0223 8 +Direct_short_integration_time 0x0224 16 +Short_analog_linear_gain_global 0x0226 16 v1.1 +Short_analog_exponential_gain_global 0x0228 16 v1.1 + +# clock set-up registers +vt_pix_clk_div 0x0300 16 +vt_sys_clk_div 0x0302 16 +pre_pll_clk_div 0x0304 16 +#vt_pre_pll_clk_div 0x0304 16 +pll_multiplier 0x0306 16 +#vt_pll_multiplier 0x0306 16 +op_pix_clk_div 0x0308 16 +op_sys_clk_div 0x030a 16 +op_pre_pll_clk_div 0x030c 16 +op_pll_multiplier 0x030e 16 +pll_mode 0x0310 8 +- f 0 0 +- e single 0 +- e dual 1 +op_pix_clk_div_rev 0x0312 16 v1.1 +op_sys_clk_div_rev 0x0314 16 v1.1 + +# frame timing registers +frame_length_lines 0x0340 16 +line_length_pck 0x0342 16 + +# image size registers +x_addr_start 0x0344 16 +y_addr_start 0x0346 16 +x_addr_end 0x0348 16 +y_addr_end 0x034a 16 +x_output_size 0x034c 16 +y_output_size 0x034e 16 + +# timing mode registers +Frame_length_ctrl 0x0350 8 +- b automatic 0 +Timing_mode_ctrl 0x0352 8 +- b manual_readout 0 +- b delayed_exposure 1 +Start_readout_rs 0x0353 8 +- b manual_readout_start 0 +Frame_margin 0x0354 16 + +# sub-sampling registers +x_even_inc 0x0380 16 +x_odd_inc 0x0382 16 +y_even_inc 0x0384 16 +y_odd_inc 0x0386 16 + +# monochrome readout registers +monochrome_en 0x0390 v1.1 +- e enabled 0 + +# image scaling registers +Scaling_mode 0x0400 16 +- e no_scaling 0 +- e horizontal 1 +scale_m 0x0404 16 +scale_n 0x0406 16 +digital_crop_x_offset 0x0408 16 +digital_crop_y_offset 0x040a 16 +digital_crop_image_width 0x040c 16 +digital_crop_image_height 0x040e 16 + +# image compression registers +compression_mode 0x0500 16 +- e none 0 +- e dpcm_pcm_simple 1 + +# test pattern registers +test_pattern_mode 0x0600 16 +- e none 0 +- e solid_color 1 +- e color_bars 2 +- e fade_to_grey 3 +- e pn9 4 +- e color_tile 5 +test_data_red 0x0602 16 +test_data_greenR 0x0604 16 +test_data_blue 0x0606 16 +test_data_greenB 0x0608 16 +value_step_size_smooth 0x060a 8 +value_step_size_quantised 0x060b 8 + +# phy configuration registers +tclk_post 0x0800 8 +ths_prepare 0x0801 8 +ths_zero_min 0x0802 8 +ths_trail 0x0803 8 +tclk_trail_min 0x0804 8 +tclk_prepare 0x0805 8 +tclk_zero 0x0806 8 +tlpx 0x0807 8 +phy_ctrl 0x0808 8 +- e auto 0 +- e UI 1 +- e manual 2 +tclk_post_ex 0x080a 16 +ths_prepare_ex 0x080c 16 +ths_zero_min_ex 0x080e 16 +ths_trail_ex 0x0810 16 +tclk_trail_min_ex 0x0812 16 +tclk_prepare_ex 0x0814 16 +tclk_zero_ex 0x0816 16 +tlpx_ex 0x0818 16 + +# link rate register +requested_link_rate 0x0820 32 u16.16 + +# equalization control registers +DPHY_equalization_mode 0x0824 8 v1.1 +- b eq2 0 +PHY_equalization_ctrl 0x0825 8 v1.1 +- b enable 0 + +# d-phy preamble control registers +DPHY_preamble_ctrl 0x0826 8 v1.1 +- b enable 0 +DPHY_preamble_length 0x0826 8 v1.1 + +# d-phy spread spectrum control registers +PHY_SSC_ctrl 0x0828 8 v1.1 +- b enable 0 + +# manual lp control register +manual_LP_ctrl 0x0829 8 v1.1 +- b enable 0 + +# additional phy configuration registers +twakeup 0x082a v1.1 +tinit 0x082b v1.1 +ths_exit 0x082c v1.1 +ths_exit_ex 0x082e 16 v1.1 + +# phy calibration configuration registers +PHY_periodic_calibration_ctrl 0x0830 8 +- b frame_blanking 0 +PHY_periodic_calibration_interval 0x0831 8 +PHY_init_calibration_ctrl 0x0832 8 +- b stream_start 0 +DPHY_calibration_mode 0x0833 8 v1.1 +- b also_alternate 0 +CPHY_calibration_mode 0x0834 8 v1.1 +- e format_1 0 +- e format_2 1 +- e format_3 2 +t3_calpreamble_length 0x0835 8 v1.1 +t3_calpreamble_length_per 0x0836 8 v1.1 +t3_calaltseq_length 0x0837 8 v1.1 +t3_calaltseq_length_per 0x0838 8 v1.1 +FM2_init_seed 0x083a 16 v1.1 +t3_caludefseq_length 0x083c 16 v1.1 +t3_caludefseq_length_per 0x083e 16 v1.1 + +# c-phy manual control registers +TGR_Preamble_Length 0x0841 8 +- b preamable_prog_seq 7 +- f begin_preamble_length 0 5 +TGR_Post_Length 0x0842 8 +- f post_length 0 4 +TGR_Preamble_Prog_Sequence(n2) 0x0843 +- l n2 0 6 1 +- f symbol_n_1 3 5 +- f symbol_n 0 2 +t3_prepare 0x084e 16 +t3_lpx 0x0850 16 + +# alps control register +ALPS_ctrl 0x085a 8 +- b lvlp_dphy 0 +- b lvlp_cphy 1 +- b alp_cphy 2 + +# lrte control registers +TX_REG_CSI_EPD_EN_SSP_cphy 0x0860 16 +TX_REG_CSI_EPD_OP_SLP_cphy 0x0862 16 +TX_REG_CSI_EPD_EN_SSP_dphy 0x0864 16 +TX_REG_CSI_EPD_OP_SLP_dphy 0x0866 16 +TX_REG_CSI_EPD_MISC_OPTION_cphy 0x0868 v1.1 +TX_REG_CSI_EPD_MISC_OPTION_dphy 0x0869 v1.1 + +# scrambling control registers +Scrambling_ctrl 0x0870 +- b enabled 0 +- f 2 3 +- e 1_seed_cphy 0 +- e 4_seed_cphy 3 +lane_seed_value(seed, lane) 0x0872 16 +- l seed 0 3 0x10 +- l lane 0 7 0x2 + +# usl control registers +TX_USL_REV_ENTRY 0x08c0 16 v1.1 +TX_USL_REV_Clock_Counter 0x08c2 16 v1.1 +TX_USL_REV_LP_Counter 0x08c4 16 v1.1 +TX_USL_REV_Frame_Counter 0x08c6 16 v1.1 +TX_USL_REV_Chronological_Timer 0x08c8 16 v1.1 +TX_USL_FWD_ENTRY 0x08ca 16 v1.1 +TX_USL_GPIO 0x08cc 16 v1.1 +TX_USL_Operation 0x08ce 16 v1.1 +- b reset 0 +TX_USL_ALP_ctrl 0x08d0 16 v1.1 +- b clock_pause 0 +TX_USL_APP_BTA_ACK_TIMEOUT 0x08d2 16 v1.1 +TX_USL_SNS_BTA_ACK_TIMEOUT 0x08d2 16 v1.1 +USL_Clock_Mode_d_ctrl 0x08d2 v1.1 +- b cont_clock_standby 0 +- b cont_clock_vblank 1 +- b cont_clock_hblank 2 + +# binning configuration registers +binning_mode 0x0900 8 +binning_type 0x0901 8 +binning_weighting 0x0902 8 + +# data transfer interface registers +data_transfer_if_1_ctrl 0x0a00 8 +- b enable 0 +- b write 1 +- b clear_error 2 +data_transfer_if_1_status 0x0a01 8 +- b read_if_ready 0 +- b write_if_ready 1 +- b data_corrupted 2 +- b improper_if_usage 3 +data_transfer_if_1_page_select 0x0a02 8 +data_transfer_if_1_data(p) 0x0a04 8 f +- l p 0 63 1 + +# image processing and sensor correction configuration registers +shading_correction_en 0x0b00 8 +- b enable 0 +luminance_correction_level 0x0b01 8 +green_imbalance_filter_en 0x0b02 8 +- b enable 0 +mapped_defect_correct_en 0x0b05 8 +- b enable 0 +single_defect_correct_en 0x0b06 8 +- b enable 0 +dynamic_couplet_correct_en 0x0b08 8 +- b enable 0 +combined_defect_correct_en 0x0b0a 8 +- b enable 0 +module_specific_correction_en 0x0b0c 8 +- b enable 0 +dynamic_triplet_defect_correct_en 0x0b13 8 +- b enable 0 +NF_ctrl 0x0b15 8 +- b luma 0 +- b chroma 1 +- b combined 2 + +# optical black pixel readout registers +OB_readout_control 0x0b30 8 +- b enable 0 +- b interleaving 1 +OB_virtual_channel 0x0b31 8 +OB_DT 0x0b32 8 +OB_data_format 0x0b33 8 + +# color temperature feedback registers +color_temperature 0x0b8c 16 +absolute_gain_greenr 0x0b8e 16 +absolute_gain_red 0x0b90 16 +absolute_gain_blue 0x0b92 16 +absolute_gain_greenb 0x0b94 16 + +# cfa conversion registers +CFA_conversion_ctrl 0x0ba0 v1.1 +- b bayer_conversion_enable 0 + +# flash strobe and sa strobe control registers +flash_strobe_adjustment 0x0c12 8 +flash_strobe_start_point 0x0c14 16 +tflash_strobe_delay_rs_ctrl 0x0c16 16 +tflash_strobe_width_high_rs_ctrl 0x0c18 16 +flash_mode_rs 0x0c1a 8 +- b continuous 0 +- b truncate 1 +- b async 3 +flash_trigger_rs 0x0c1b 8 +flash_status 0x0c1c 8 +- b retimed 0 +sa_strobe_mode 0x0c1d 8 +- b continuous 0 +- b truncate 1 +- b async 3 +- b adjust_edge 4 +sa_strobe_start_point 0x0c1e 16 +tsa_strobe_delay_ctrl 0x0c20 16 +tsa_strobe_width_ctrl 0x0c22 16 +sa_strobe_trigger 0x0c24 8 +sa_strobe_status 0x0c25 8 +- b retimed 0 +tSA_strobe_re_delay_ctrl 0x0c30 16 +tSA_strobe_fe_delay_ctrl 0x0c32 16 + +# pdaf control registers +PDAF_ctrl 0x0d00 16 +- b enable 0 +- b processed 1 +- b interleaved 2 +- b visible_pdaf_correction 3 +PDAF_VC 0x0d02 8 +PDAF_DT 0x0d03 8 +pd_x_addr_start 0x0d04 16 +pd_y_addr_start 0x0d06 16 +pd_x_addr_end 0x0d08 16 +pd_y_addr_end 0x0d0a 16 + +# bracketing interface configuration registers +bracketing_LUT_ctrl 0x0e00 8 +bracketing_LUT_mode 0x0e01 8 +- b continue_streaming 0 +- b loop_mode 1 +bracketing_LUT_entry_ctrl 0x0e02 8 +bracketing_LUT_frame(n) 0x0e10 v1.1 f +- l n 0 0xef 1 + +# integration time and gain parameter limit registers +integration_time_capability 0x1000 16 +- b fine 0 +coarse_integration_time_min 0x1004 16 +coarse_integration_time_max_margin 0x1006 16 +fine_integration_time_min 0x1008 16 +fine_integration_time_max_margin 0x100a 16 + +# digital gain parameter limit registers +digital_gain_capability 0x1081 +- e none 0 +- e global 2 +digital_gain_min 0x1084 16 +digital_gain_max 0x1086 16 +digital_gain_step_size 0x1088 16 + +# data pedestal capability registers +Pedestal_capability 0x10e0 8 v1.1 + +# adc capability registers +ADC_capability 0x10f0 8 +- b bit_depth_ctrl 0 +ADC_bit_depth_capability 0x10f4 32 v1.1 + +# video timing parameter limit registers +min_ext_clk_freq_mhz 0x1100 32 float_ireal +max_ext_clk_freq_mhz 0x1104 32 float_ireal +min_pre_pll_clk_div 0x1108 16 +# min_vt_pre_pll_clk_div 0x1108 16 +max_pre_pll_clk_div 0x110a 16 +# max_vt_pre_pll_clk_div 0x110a 16 +min_pll_ip_clk_freq_mhz 0x110c 32 float_ireal +# min_vt_pll_ip_clk_freq_mhz 0x110c 32 float_ireal +max_pll_ip_clk_freq_mhz 0x1110 32 float_ireal +# max_vt_pll_ip_clk_freq_mhz 0x1110 32 float_ireal +min_pll_multiplier 0x1114 16 +# min_vt_pll_multiplier 0x1114 16 +max_pll_multiplier 0x1116 16 +# max_vt_pll_multiplier 0x1116 16 +min_pll_op_clk_freq_mhz 0x1118 32 float_ireal +max_pll_op_clk_freq_mhz 0x111c 32 float_ireal + +# video timing set-up capability registers +min_vt_sys_clk_div 0x1120 16 +max_vt_sys_clk_div 0x1122 16 +min_vt_sys_clk_freq_mhz 0x1124 32 float_ireal +max_vt_sys_clk_freq_mhz 0x1128 32 float_ireal +min_vt_pix_clk_freq_mhz 0x112c 32 float_ireal +max_vt_pix_clk_freq_mhz 0x1130 32 float_ireal +min_vt_pix_clk_div 0x1134 16 +max_vt_pix_clk_div 0x1136 16 +clock_calculation 0x1138 +- b lane_speed 0 +- b link_decoupled 1 +- b dual_pll_op_sys_ddr 2 +- b dual_pll_op_pix_ddr 3 +num_of_vt_lanes 0x1139 +num_of_op_lanes 0x113a +op_bits_per_lane 0x113b 8 v1.1 + +# frame timing parameter limits +min_frame_length_lines 0x1140 16 +max_frame_length_lines 0x1142 16 +min_line_length_pck 0x1144 16 +max_line_length_pck 0x1146 16 +min_line_blanking_pck 0x1148 16 +min_frame_blanking_lines 0x114a 16 +min_line_length_pck_step_size 0x114c +timing_mode_capability 0x114d +- b auto_frame_length 0 +- b rolling_shutter_manual_readout 2 +- b delayed_exposure_start 3 +- b manual_exposure_embedded_data 4 +frame_margin_max_value 0x114e 16 +frame_margin_min_value 0x1150 +gain_delay_type 0x1151 +- e fixed 0 +- e variable 1 + +# output clock set-up capability registers +min_op_sys_clk_div 0x1160 16 +max_op_sys_clk_div 0x1162 16 +min_op_sys_clk_freq_mhz 0x1164 32 float_ireal +max_op_sys_clk_freq_mhz 0x1168 32 float_ireal +min_op_pix_clk_div 0x116c 16 +max_op_pix_clk_div 0x116e 16 +min_op_pix_clk_freq_mhz 0x1170 32 float_ireal +max_op_pix_clk_freq_mhz 0x1174 32 float_ireal + +# image size parameter limit registers +x_addr_min 0x1180 16 +y_addr_min 0x1182 16 +x_addr_max 0x1184 16 +y_addr_max 0x1186 16 +min_x_output_size 0x1188 16 +min_y_output_size 0x118a 16 +max_x_output_size 0x118c 16 +max_y_output_size 0x118e 16 + +x_addr_start_div_constant 0x1190 v1.1 +y_addr_start_div_constant 0x1191 v1.1 +x_addr_end_div_constant 0x1192 v1.1 +y_addr_end_div_constant 0x1193 v1.1 +x_size_div 0x1194 v1.1 +y_size_div 0x1195 v1.1 +x_output_div 0x1196 v1.1 +y_output_div 0x1197 v1.1 +non_flexible_resolution_support 0x1198 v1.1 +- b new_pix_addr 0 +- b new_output_res 1 +- b output_crop_no_pad 2 +- b output_size_lane_dep 3 + +min_op_pre_pll_clk_div 0x11a0 16 +max_op_pre_pll_clk_div 0x11a2 16 +min_op_pll_ip_clk_freq_mhz 0x11a4 32 float_ireal +max_op_pll_ip_clk_freq_mhz 0x11a8 32 float_ireal +min_op_pll_multiplier 0x11ac 16 +max_op_pll_multiplier 0x11ae 16 +min_op_pll_op_clk_freq_mhz 0x11b0 32 float_ireal +max_op_pll_op_clk_freq_mhz 0x11b4 32 float_ireal +clock_tree_pll_capability 0x11b8 8 +- b dual_pll 0 +- b single_pll 1 +- b ext_divider 2 +- b flexible_op_pix_clk_div 3 +clock_capa_type_capability 0x11b9 v1.1 +- b ireal 0 + +# sub-sampling parameters limit registers +min_even_inc 0x11c0 16 +min_odd_inc 0x11c2 16 +max_even_inc 0x11c4 16 +max_odd_inc 0x11c6 16 +aux_subsamp_capability 0x11c8 v1.1 +- b factor_power_of_2 1 +aux_subsamp_mono_capability 0x11c9 v1.1 +- b factor_power_of_2 1 +monochrome_capability 0x11ca v1.1 +- e inc_odd 0 +- e inc_even 1 +pixel_readout_capability 0x11cb v1.1 +- e bayer 0 +- e monochrome 1 +- e bayer_and_mono 2 +min_even_inc_mono 0x11cc 16 v1.1 +max_even_inc_mono 0x11ce 16 v1.1 +min_odd_inc_mono 0x11d0 16 v1.1 +max_odd_inc_mono 0x11d2 16 v1.1 +min_even_inc_bc2 0x11d4 16 v1.1 +max_even_inc_bc2 0x11d6 16 v1.1 +min_odd_inc_bc2 0x11d8 16 v1.1 +max_odd_inc_bc2 0x11da 16 v1.1 +min_even_inc_mono_bc2 0x11dc 16 v1.1 +max_even_inc_mono_bc2 0x11de 16 v1.1 +min_odd_inc_mono_bc2 0x11f0 16 v1.1 +max_odd_inc_mono_bc2 0x11f2 16 v1.1 + +# image scaling limit parameters +scaling_capability 0x1200 16 +- e none 0 +- e horizontal 1 +- e reserved 2 +scaler_m_min 0x1204 16 +scaler_m_max 0x1206 16 +scaler_n_min 0x1208 16 +scaler_n_max 0x120a 16 +digital_crop_capability 0x120e +- e none 0 +- e input_crop 1 + +# hdr limit registers +hdr_capability_1 0x1210 +- b 2x2_binning 0 +- b combined_analog_gain 1 +- b separate_analog_gain 2 +- b upscaling 3 +- b reset_sync 4 +- b direct_short_exp_timing 5 +- b direct_short_exp_synthesis 6 +min_hdr_bit_depth 0x1211 +hdr_resolution_sub_types 0x1212 +hdr_resolution_sub_type(n) 0x1213 +- l n 0 1 1 +- f row 0 3 +- f column 4 7 +hdr_capability_2 0x121b +- b combined_digital_gain 0 +- b separate_digital_gain 1 +- b timing_mode 3 +- b synthesis_mode 4 +max_hdr_bit_depth 0x121c + +# usl capability register +usl_support_capability 0x1230 v1.1 +- b clock_tree 0 +- b rev_clock_tree 1 +- b rev_clock_calc 2 +usl_clock_mode_d_capability 0x1231 v1.1 +- b cont_clock_standby 0 +- b cont_clock_vblank 1 +- b cont_clock_hblank 2 +- b noncont_clock_standby 3 +- b noncont_clock_vblank 4 +- b noncont_clock_hblank 5 +min_op_sys_clk_div_rev 0x1234 v1.1 +max_op_sys_clk_div_rev 0x1236 v1.1 +min_op_pix_clk_div_rev 0x1238 v1.1 +max_op_pix_clk_div_rev 0x123a v1.1 +min_op_sys_clk_freq_rev_mhz 0x123c 32 v1.1 float_ireal +max_op_sys_clk_freq_rev_mhz 0x1240 32 v1.1 float_ireal +min_op_pix_clk_freq_rev_mhz 0x1244 32 v1.1 float_ireal +max_op_pix_clk_freq_rev_mhz 0x1248 32 v1.1 float_ireal +max_bitrate_rev_d_mode_mbps 0x124c 32 v1.1 ireal +max_symrate_rev_c_mode_msps 0x1250 32 v1.1 ireal + +# image compression capability registers +compression_capability 0x1300 +- b dpcm_pcm_simple 0 + +# test mode capability registers +test_mode_capability 0x1310 16 +- b solid_color 0 +- b color_bars 1 +- b fade_to_grey 2 +- b pn9 3 +- b color_tile 5 +pn9_data_format1 0x1312 +pn9_data_format2 0x1313 +pn9_data_format3 0x1314 +pn9_data_format4 0x1315 +pn9_misc_capability 0x1316 +- f num_pixels 0 2 +- b compression 3 +test_pattern_capability 0x1317 v1.1 +- b no_repeat 1 +pattern_size_div_m1 0x1318 v1.1 + +# fifo capability registers +fifo_support_capability 0x1502 +- e none 0 +- e derating 1 +- e derating_overrating 2 + +# csi-2 capability registers +phy_ctrl_capability 0x1600 +- b auto_phy_ctl 0 +- b ui_phy_ctl 1 +- b dphy_time_ui_reg_1_ctl 2 +- b dphy_time_ui_reg_2_ctl 3 +- b dphy_time_ctl 4 +- b dphy_ext_time_ui_reg_1_ctl 5 +- b dphy_ext_time_ui_reg_2_ctl 6 +- b dphy_ext_time_ctl 7 +csi_dphy_lane_mode_capability 0x1601 +- b 1_lane 0 +- b 2_lane 1 +- b 3_lane 2 +- b 4_lane 3 +- b 5_lane 4 +- b 6_lane 5 +- b 7_lane 6 +- b 8_lane 7 +csi_signaling_mode_capability 0x1602 +- b csi_dphy 2 +- b csi_cphy 3 +fast_standby_capability 0x1603 +- e no_frame_truncation 0 +- e frame_truncation 1 +csi_address_control_capability 0x1604 +- b cci_addr_change 0 +- b 2nd_cci_addr 1 +- b sw_changeable_2nd_cci_addr 2 +data_type_capability 0x1605 +- b dpcm_programmable 0 +- b bottom_embedded_dt_programmable 1 +- b bottom_embedded_vc_programmable 2 +- b ext_vc_range 3 +csi_cphy_lane_mode_capability 0x1606 +- b 1_lane 0 +- b 2_lane 1 +- b 3_lane 2 +- b 4_lane 3 +- b 5_lane 4 +- b 6_lane 5 +- b 7_lane 6 +- b 8_lane 7 +emb_data_capability 0x1607 v1.1 +- b two_bytes_per_raw16 0 +- b two_bytes_per_raw20 1 +- b two_bytes_per_raw24 2 +- b no_one_byte_per_raw16 3 +- b no_one_byte_per_raw20 4 +- b no_one_byte_per_raw24 5 +max_per_lane_bitrate_lane_d_mode_mbps(n) 0x1608 32 ireal +- l n 0 7 4 4,0x32 +temp_sensor_capability 0x1618 +- b supported 0 +- b CCS_format 1 +- b reset_0x80 2 +max_per_lane_bitrate_lane_c_mode_mbps(n) 0x161a 32 ireal +- l n 0 7 4 4,0x30 +dphy_equalization_capability 0x162b +- b equalization_ctrl 0 +- b eq1 1 +- b eq2 2 +cphy_equalization_capability 0x162c +- b equalization_ctrl 0 +dphy_preamble_capability 0x162d +- b preamble_seq_ctrl 0 +dphy_ssc_capability 0x162e +- b supported 0 +cphy_calibration_capability 0x162f +- b manual 0 +- b manual_streaming 1 +- b format_1_ctrl 2 +- b format_2_ctrl 3 +- b format_3_ctrl 4 +dphy_calibration_capability 0x1630 +- b manual 0 +- b manual_streaming 1 +- b alternate_seq 2 +phy_ctrl_capability_2 0x1631 +- b tgr_length 0 +- b tgr_preamble_prog_seq 1 +- b extra_cphy_manual_timing 2 +- b clock_based_manual_cdphy 3 +- b clock_based_manual_dphy 4 +- b clock_based_manual_cphy 5 +- b manual_lp_dphy 6 +- b manual_lp_cphy 7 +lrte_cphy_capability 0x1632 +- b pdq_short 0 +- b spacer_short 1 +- b pdq_long 2 +- b spacer_long 3 +- b spacer_no_pdq 4 +lrte_dphy_capability 0x1633 +- b pdq_short_opt1 0 +- b spacer_short_opt1 1 +- b pdq_long_opt1 2 +- b spacer_long_opt1 3 +- b spacer_short_opt2 4 +- b spacer_long_opt2 5 +- b spacer_no_pdq_opt1 6 +- b spacer_variable_opt2 7 +alps_capability_dphy 0x1634 +- e lvlp_not_supported 0 0x3 +- e lvlp_supported 1 0x3 +- e controllable_lvlp 2 0x3 +alps_capability_cphy 0x1635 +- e lvlp_not_supported 0 0x3 +- e lvlp_supported 1 0x3 +- e controllable_lvlp 2 0x3 +- e alp_not_supported 0xc 0xc +- e alp_supported 0xd 0xc +- e controllable_alp 0xe 0xc +scrambling_capability 0x1636 +- b scrambling_supported 0 +- f max_seeds_per_lane_c 1 2 +- e 1 0 +- e 4 3 +- f num_seed_regs 3 5 +- e 0 0 +- e 1 1 +- e 4 4 +- b num_seed_per_lane 6 +dphy_manual_constant 0x1637 +cphy_manual_constant 0x1638 +CSI2_interface_capability_misc 0x1639 v1.1 +- b eotp_short_pkt_opt2 0 +PHY_ctrl_capability_3 0x165c v1.1 +- b dphy_timing_not_multiple 0 +- b dphy_min_timing_value_1 1 +- b twakeup_supported 2 +- b tinit_supported 3 +- b ths_exit_supported 4 +- b cphy_timing_not_multiple 5 +- b cphy_min_timing_value_1 6 +dphy_sf 0x165d v1.1 +cphy_sf 0x165e v1.1 +- f twakeup 0 3 +- f tinit 4 7 +dphy_limits_1 0x165f v1.1 +- f ths_prepare 0 3 +- f ths_zero 4 7 +dphy_limits_2 0x1660 v1.1 +- f ths_trail 0 3 +- f tclk_trail_min 4 7 +dphy_limits_3 0x1661 v1.1 +- f tclk_prepare 0 3 +- f tclk_zero 4 7 +dphy_limits_4 0x1662 v1.1 +- f tclk_post 0 3 +- f tlpx 4 7 +dphy_limits_5 0x1663 v1.1 +- f ths_exit 0 3 +- f twakeup 4 7 +dphy_limits_6 0x1664 v1.1 +- f tinit 0 3 +cphy_limits_1 0x1665 v1.1 +- f t3_prepare_max 0 3 +- f t3_lpx_max 4 7 +cphy_limits_2 0x1666 v1.1 +- f ths_exit_max 0 3 +- f twakeup_max 4 7 +cphy_limits_3 0x1667 v1.1 +- f tinit_max 0 3 + +# binning capability registers +min_frame_length_lines_bin 0x1700 16 +max_frame_length_lines_bin 0x1702 16 +min_line_length_pck_bin 0x1704 16 +max_line_length_pck_bin 0x1706 16 +min_line_blanking_pck_bin 0x1708 16 +fine_integration_time_min_bin 0x170a 16 +fine_integration_time_max_margin_bin 0x170c 16 +binning_capability 0x1710 +- e unsupported 0 +- e binning_then_subsampling 1 +- e subsampling_then_binning 2 +binning_weighting_capability 0x1711 +- b averaged 0 +- b summed 1 +- b bayer_corrected 2 +- b module_specific_weight 3 +binning_sub_types 0x1712 +binning_sub_type(n) 0x1713 +- l n 0 63 1 +- f row 0 3 +- f column 4 7 +binning_weighting_mono_capability 0x1771 v1.1 +- b averaged 0 +- b summed 1 +- b bayer_corrected 2 +- b module_specific_weight 3 +binning_sub_types_mono 0x1772 v1.1 +binning_sub_type_mono(n) 0x1773 v1.1 f +- l n 0 63 1 + +# data transfer interface capability registers +data_transfer_if_capability 0x1800 +- b supported 0 +- b polling 2 + +# sensor correction capability registers +shading_correction_capability 0x1900 +- b color_shading 0 +- b luminance_correction 1 +green_imbalance_capability 0x1901 +- b supported 0 +module_specific_correction_capability 0x1903 +defect_correction_capability 0x1904 16 +- b mapped_defect 0 +- b dynamic_couplet 2 +- b dynamic_single 5 +- b combined_dynamic 8 +defect_correction_capability_2 0x1906 16 +- b dynamic_triplet 3 +nf_capability 0x1908 +- b luma 0 +- b chroma 1 +- b combined 2 + +# optical black readout capability registers +ob_readout_capability 0x1980 +- b controllable_readout 0 +- b visible_pixel_readout 1 +- b different_vc_readout 2 +- b different_dt_readout 3 +- b prog_data_format 4 + +# color feedback capability registers +color_feedback_capability 0x1987 +- b kelvin 0 +- b awb_gain 1 + +# cfa pattern capability registers +CFA_pattern_capability 0x1990 v1.1 +- e bayer 0 +- e monochrome 1 +- e 4x4_quad_bayer 2 +- e vendor_specific 3 +CFA_pattern_conversion_capability 0x1991 v1.1 +- b bayer 0 + +# timer capability registers +flash_mode_capability 0x1a02 +- b single_strobe 0 +sa_strobe_mode_capability 0x1a03 +- b fixed_width 0 +- b edge_ctrl 1 + +# soft reset capability registers +reset_max_delay 0x1a10 v1.1 +reset_min_time 0x1a11 v1.1 + +# pdaf capability registers +pdaf_capability_1 0x1b80 +- b supported 0 +- b processed_bottom_embedded 1 +- b processed_interleaved 2 +- b raw_bottom_embedded 3 +- b raw_interleaved 4 +- b visible_pdaf_correction 5 +- b vc_interleaving 6 +- b dt_interleaving 7 +pdaf_capability_2 0x1b81 +- b ROI 0 +- b after_digital_crop 1 +- b ctrl_retimed 2 + +# bracketing interface capability registers +bracketing_lut_capability_1 0x1c00 +- b coarse_integration 0 +- b global_analog_gain 1 +- b flash 4 +- b global_digital_gain 5 +- b alternate_global_analog_gain 6 +bracketing_lut_capability_2 0x1c01 +- b single_bracketing_mode 0 +- b looped_bracketing_mode 1 +bracketing_lut_size 0x1c02 diff --git a/Documentation/driver-api/media/drivers/ccs/ccs.rst b/Documentation/driver-api/media/drivers/ccs/ccs.rst new file mode 100644 index 000000000..5d4451339 --- /dev/null +++ b/Documentation/driver-api/media/drivers/ccs/ccs.rst @@ -0,0 +1,82 @@ +.. SPDX-License-Identifier: GPL-2.0-only OR BSD-3-Clause + +.. include:: <isonum.txt> + +.. _media-ccs-driver: + +MIPI CCS camera sensor driver +============================= + +The MIPI CCS camera sensor driver is a generic driver for `MIPI CCS +<https://www.mipi.org/specifications/camera-command-set>`_ compliant +camera sensors. + +Also see :ref:`the CCS driver UAPI documentation <media-ccs-uapi>`. + +CCS static data +--------------- + +The MIPI CCS driver supports CCS static data for all compliant devices, +including not just those compliant with CCS 1.1 but also CCS 1.0 and SMIA(++). +For CCS the file names are formed as + + ccs/ccs-sensor-vvvv-mmmm-rrrr.fw (sensor) and + ccs/ccs-module-vvvv-mmmm-rrrr.fw (module). + +For SMIA++ compliant devices the corresponding file names are + + ccs/smiapp-sensor-vv-mmmm-rr.fw (sensor) and + ccs/smiapp-module-vv-mmmm-rrrr.fw (module). + +For SMIA (non-++) compliant devices the static data file name is + + ccs/smia-sensor-vv-mmmm-rr.fw (sensor). + +vvvv or vv denotes MIPI and SMIA manufacturer IDs respectively, mmmm model ID +and rrrr or rr revision number. + +CCS tools +~~~~~~~~~ + +`CCS tools <https://github.com/MIPI-Alliance/ccs-tools/>`_ is a set of +tools for working with CCS static data files. CCS tools includes a +definition of the human-readable CCS static data YAML format and includes a +program to convert it to a binary. + +Register definition generator +----------------------------- + +The ccs-regs.asc file contains MIPI CCS register definitions that are used +to produce C source code files for definitions that can be better used by +programs written in C language. As there are many dependencies between the +produced files, please do not modify them manually as it's error-prone and +in vain, but instead change the script producing them. + +Usage +~~~~~ + +Conventionally the script is called this way to update the CCS driver +definitions: + +.. code-block:: none + + $ Documentation/driver-api/media/drivers/ccs/mk-ccs-regs -k \ + -e drivers/media/i2c/ccs/ccs-regs.h \ + -L drivers/media/i2c/ccs/ccs-limits.h \ + -l drivers/media/i2c/ccs/ccs-limits.c \ + -c Documentation/driver-api/media/drivers/ccs/ccs-regs.asc + +CCS PLL calculator +================== + +The CCS PLL calculator is used to compute the PLL configuration, given sensor's +capabilities as well as board configuration and user specified configuration. As +the configuration space that encompasses all these configurations is vast, the +PLL calculator isn't entirely trivial. Yet it is relatively simple to use for a +driver. + +The PLL model implemented by the PLL calculator corresponds to MIPI CCS 1.1. + +.. kernel-doc:: drivers/media/i2c/ccs-pll.h + +**Copyright** |copy| 2020 Intel Corporation diff --git a/Documentation/driver-api/media/drivers/ccs/mk-ccs-regs b/Documentation/driver-api/media/drivers/ccs/mk-ccs-regs new file mode 100755 index 000000000..3d3152b45 --- /dev/null +++ b/Documentation/driver-api/media/drivers/ccs/mk-ccs-regs @@ -0,0 +1,480 @@ +#!/usr/bin/perl -w +# SPDX-License-Identifier: GPL-2.0-only OR BSD-3-Clause +# Copyright (C) 2019--2020 Intel Corporation + +use Getopt::Long qw(:config no_ignore_case); +use File::Basename; + +my $ccsregs = "ccs-regs.asc"; +my $header; +my $regarray; +my $limitc; +my $limith; +my $kernel; +my $help; + +GetOptions("ccsregs|c=s" => \$ccsregs, + "header|e=s" => \$header, + "regarray|r=s" => \$regarray, + "limitc|l=s" => \$limitc, + "limith|L=s" => \$limith, + "kernel|k" => \$kernel, + "help|h" => \$help) or die "can't parse options"; + +$help = 1 if ! defined $header || ! defined $limitc || ! defined $limith; + +if (defined $help) { + print <<EOH +$0 - Create CCS register definitions for C + +usage: $0 -c ccs-regs.asc -e header -r regarray -l limit-c -L limit-header [-k] + + -c ccs register file + -e header file name + -r register description array file name + -l limit and capability array file name + -L limit and capability header file name + -k generate files for kernel space consumption +EOH + ; + exit 0; +} + +my $lh_hdr = ! defined $kernel + ? '#include "ccs-os.h"' . "\n" + : "#include <linux/bits.h>\n#include <linux/types.h>\n"; +my $uint32_t = ! defined $kernel ? 'uint32_t' : 'u32'; +my $uint16_t = ! defined $kernel ? 'uint16_t' : 'u16'; + +open(my $R, "< $ccsregs") or die "can't open $ccsregs"; + +open(my $H, "> $header") or die "can't open $header"; +my $A; +if (defined $regarray) { + open($A, "> $regarray") or die "can't open $regarray"; +} +open(my $LC, "> $limitc") or die "can't open $limitc"; +open(my $LH, "> $limith") or die "can't open $limith"; + +my %this; + +sub is_limit_reg($) { + my $addr = hex $_[0]; + + return 0 if $addr < 0x40; # weed out status registers + return 0 if $addr >= 0x100 && $addr < 0xfff; # weed out configuration registers + + return 1; +} + +my $uc_header = basename uc $header; +$uc_header =~ s/[^A-Z0-9]/_/g; + +my $copyright = "/* Copyright (C) 2019--2020 Intel Corporation */\n"; +my $license = "SPDX-License-Identifier: GPL-2.0-only OR BSD-3-Clause"; +my $note = "/*\n * Generated by $0;\n * do not modify.\n */\n"; + +for my $fh ($A, $LC) { + print $fh "// $license\n$copyright$note\n" if defined $fh; +} + +for my $fh ($H, $LH) { + print $fh "/* $license */\n$copyright$note\n"; +} + +print $H <<EOF +#ifndef __${uc_header}__ +#define __${uc_header}__ + +EOF + ; + +print $H <<EOF +#include <linux/bits.h> + +#include <media/v4l2-cci.h> + +EOF + if defined $kernel; + +print $H "#define CCS_FL_BASE " . + (defined $kernel ? "CCI_REG_PRIVATE_SHIFT" : 16) . "\n"; + +my $flag = -1; +my $all_flags; + +sub bit_def($) { + my $bit = shift @_; + + if (defined $kernel) { + return "BIT$bit" if $bit =~ /^\(.*\)$/; + return "BIT($bit)"; + } + return "(1U << $bit)"; +} + +sub flag_str($$) { + my ($flag, $check) = @_; + + $$flag++; + + my $flag_str = !$$flag ? "CCS_FL_BASE" : "(CCS_FL_BASE + $$flag)"; + + $flag_str = bit_def($flag_str); + + $$check .= " | " if defined $$check; + + $$check .= $flag_str; + + return $flag_str; +} + +if (! defined $kernel) { + print $H "#define CCS_FL_16BIT " . flag_str(\$flag, \$all_flags) . "\n"; + print $H "#define CCS_FL_32BIT " . flag_str(\$flag, \$all_flags) . "\n"; +} + +print $H "#define CCS_FL_FLOAT_IREAL " . flag_str(\$flag, \$all_flags) . "\n"; +print $H "#define CCS_FL_IREAL " . flag_str(\$flag, \$all_flags) . "\n"; +print $H "#define CCS_BUILD_BUG \\ + BUILD_BUG_ON(~CCI_REG_PRIVATE_MASK & ($all_flags))\n" + if defined $kernel; + +print $H <<EOF + +#define CCS_R_ADDR(r) ((r) & 0xffff) + +EOF + if ! defined $kernel; + +print $A <<EOF +#include <stdint.h> +#include <stdio.h> +#include "ccs-extra.h" +#include "ccs-regs.h" + +EOF + if defined $A; + +my $uc_limith = basename uc $limith; +$uc_limith =~ s/[^A-Z0-9]/_/g; + +print $LH <<EOF +#ifndef __${uc_limith}__ +#define __${uc_limith}__ + +$lh_hdr +struct ccs_limit { + $uint32_t reg; + $uint16_t size; + $uint16_t flags; + const char *name; +}; + +EOF + ; +print $LH "#define CCS_L_FL_SAME_REG " . bit_def(0) . "\n\n"; + +print $LH <<EOF +extern const struct ccs_limit ccs_limits[]; + +EOF + ; + +print $LC <<EOF +#include "ccs-limits.h" +#include "ccs-regs.h" + +const struct ccs_limit ccs_limits[] = { +EOF + ; + +my $limitcount = 0; +my $argdescs; +my $reglist = "const struct ccs_reg_desc ccs_reg_desc[] = {\n"; + +sub name_split($$) { + my ($name, $addr) = @_; + my $args; + + $name =~ /([^\(]+?)(\(.*)/; + ($name, $args) = ($1, $2); + $args = [split /,\s*/, $args]; + foreach my $t (@$args) { + $t =~ s/[\(\)]//g; + $t =~ s/\//\\\//g; + } + + return ($name, $addr, $args); +} + +sub tabconv($) { + $_ = shift; + + my @l = split "\n", $_; + + map { + s/ {8,8}/\t/g; + s/\t\K +//; + } @l; + + return (join "\n", @l) . "\n"; +} + +sub elem_bits(@) { + my @flags = @_; + + return 16 if grep /^16$/, @flags; + return 32 if grep /^32$/, @flags; + return 8; +} + +sub arr_size($) { + my $this = $_[0]; + my $size = $this->{elsize}; + my $h = $this->{argparams}; + + foreach my $arg (@{$this->{args}}) { + my $apref = $h->{$arg}; + + $size *= $apref->{max} - $apref->{min} + 1; + } + + return $size; +} + +sub print_args($$$) { + my ($this, $postfix, $is_same_reg) = @_; + my ($args, $argparams, $name) = + ($this->{args}, $this->{argparams}, $this->{name}); + my $varname = "ccs_reg_arg_" . (lc $name) . $postfix; + my @mins; + my @sorted_args = @{$this->{sorted_args}}; + my $lim_arg; + my $size = arr_size($this); + + $argdescs .= "static const struct ccs_reg_arg " . $varname . "[] = {\n"; + + foreach my $sorted_arg (@sorted_args) { + push @mins, $argparams->{$sorted_arg}->{min}; + } + + foreach my $sorted_arg (@sorted_args) { + my $h = $argparams->{$sorted_arg}; + + $argdescs .= "\t{ \"$sorted_arg\", $h->{min}, $h->{max}, $h->{elsize} },\n"; + + $lim_arg .= defined $lim_arg ? ", $h->{min}" : "$h->{min}"; + } + + $argdescs .= "};\n\n"; + + $reglist .= "\t{ CCS_R_" . (uc $name) . "(" . (join ",", (@mins)) . + "), $size, sizeof($varname) / sizeof(*$varname)," . + " \"" . (lc $name) . "\", $varname },\n"; + + print $LC tabconv sprintf "\t{ CCS_R_" . (uc $name) . "($lim_arg), " . + $size . ", " . ($is_same_reg ? "CCS_L_FL_SAME_REG" : "0") . + ", \"$name" . (defined $this->{discontig} ? " $lim_arg" : "") . "\" },\n" + if is_limit_reg $this->{base_addr}; +} + +my $hdr_data; + +while (<$R>) { + chop; + s/^\s*//; + next if /^[#;]/ || /^$/; + if (s/^-\s*//) { + if (s/^b\s*//) { + my ($bit, $addr) = split /\t+/; + $bit = uc $bit; + $hdr_data .= sprintf "#define %-62s %s", "CCS_" . (uc ${this{name}}) ."_$bit", bit_def($addr) . "\n"; + } elsif (s/^f\s*//) { + s/[,\.-]/_/g; + my @a = split /\s+/; + my ($msb, $lsb, $this_field) = reverse @a; + @a = ( { "name" => "SHIFT", "addr" => $lsb, "fmt" => "%uU", }, + { "name" => "MASK", "addr" => (1 << ($msb + 1)) - 1 - ((1 << $lsb) - 1), "fmt" => "0x%" . join(".", ($this{"elsize"} >> 2) x 2) . "x" } ); + $this{"field"} = $this_field; + foreach my $ar (@a) { + #print $ar->{fmt}."\n"; + $hdr_data .= sprintf "#define %-62s " . $ar->{"fmt"} . "\n", "CCS_" . (uc $this{"name"}) . (defined $this_field ? "_" . uc $this_field : "") . "_" . $ar->{"name"}, $ar->{"addr"} . "\n"; + } + } elsif (s/^e\s*//) { + s/[,\.-]/_/g; + my ($enum, $addr) = split /\s+/; + $enum = uc $enum; + $hdr_data .= sprintf "#define %-62s %s", "CCS_" . (uc ${this{name}}) . (defined $this{"field"} ? "_" . uc $this{"field"} : "") ."_$enum", $addr . ($addr =~ /0x/i ? "" : "U") . "\n"; + } elsif (s/^l\s*//) { + my ($arg, $min, $max, $elsize, @discontig) = split /\s+/; + my $size; + + foreach my $num ($min, $max) { + $num = hex $num if $num =~ /0x/i; + } + + $hdr_data .= sprintf "#define %-62s %s", "CCS_LIM_" . (uc ${this{name}} . "_MIN_$arg"), $min . ($min =~ /0x/i ? "" : "U") . "\n"; + $hdr_data .= sprintf "#define %-62s %s", "CCS_LIM_" . (uc ${this{name}} . "_MAX_$arg"), $max . ($max =~ /0x/i ? "" : "U") . "\n"; + + my $h = $this{argparams}; + + $h->{$arg} = { "min" => $min, + "max" => $max, + "elsize" => $elsize =~ /^0x/ ? hex $elsize : $elsize, + "discontig" => \@discontig }; + + $this{discontig} = $arg if @discontig; + + next if $#{$this{args}} + 1 != scalar keys %{$this{argparams}}; + + my $reg_formula = "$this{addr}"; + my $lim_formula; + + chop $reg_formula; + + $reg_formula = "(" . $reg_formula if $this{flagstring} ne ""; + + foreach my $arg (@{$this{args}}) { + my $d = $h->{$arg}->{discontig}; + my $times = $h->{$arg}->{elsize} != 1 ? + " * " . $h->{$arg}->{elsize} : ""; + + if (@$d) { + my ($lim, $offset) = split /,/, $d->[0]; + + $reg_formula .= " + (($arg) < $lim ? ($arg)$times : $offset + (($arg) - $lim)$times)"; + } else { + $reg_formula .= " + ($arg)$times"; + } + + $lim_formula .= (defined $lim_formula ? " + " : "") . "($arg)$times"; + } + + $reg_formula .= ")"; + $lim_formula =~ s/^\(([a-z0-9]+)\)$/$1/i; + + print $H tabconv sprintf("#define %-62s %s", "CCS_R_" . (uc $this{name}) . + $this{arglist}, $reg_formula . + (($this{flagstring} eq "") ? "" : + " | " . $this{flagstring} . ")") . "\n"); + + print $H tabconv $hdr_data; + undef $hdr_data; + + # Sort arguments in descending order by size + @{$this{sorted_args}} = sort { + $h->{$a}->{elsize} <= $h->{$b}->{elsize} + } @{$this{args}}; + + if (defined $this{discontig}) { + my $da = $this{argparams}->{$this{discontig}}; + my ($first_discontig) = split /,/, $da->{discontig}->[0]; + my $max = $da->{max}; + + $da->{max} = $first_discontig - 1; + print_args(\%this, "", 0); + + $da->{min} = $da->{max} + 1; + $da->{max} = $max; + print_args(\%this, $first_discontig, 1); + } else { + print_args(\%this, "", 0); + } + + next unless is_limit_reg $this{base_addr}; + + print $LH tabconv sprintf "#define %-63s%s\n", + "CCS_L_" . (uc $this{name}) . "_OFFSET(" . + (join ", ", @{$this{args}}) . ")", "($lim_formula)"; + } + + if (! @{$this{args}}) { + print $H tabconv($hdr_data); + undef $hdr_data; + } + + next; + } + + my ($name, $addr, @flags) = split /\t+/, $_; + my $args = []; + + my $sp; + + ($name, $addr, $args) = name_split($name, $addr) if /\(.*\)/; + + $name =~ s/[,\.-]/_/g; + + my $flagstring = ""; + my $bits = elem_bits(@flags); + if (! defined $kernel) { + $flagstring .= "| CCS_FL_16BIT " if $bits == 16; + $flagstring .= "| CCS_FL_32BIT " if $bits == 32; + } + $flagstring .= "| CCS_FL_FLOAT_IREAL " if grep /^float_ireal$/, @flags; + $flagstring .= "| CCS_FL_IREAL " if grep /^ireal$/, @flags; + $flagstring =~ s/^\| //; + $flagstring =~ s/ $//; + $flagstring = "($flagstring)" if $flagstring =~ /\|/; + my $base_addr = $addr; + $addr = "CCI_REG$bits($addr)" if defined $kernel; + + if ($flagstring ne "" && !@$args) { + $addr = "($addr | $flagstring)"; + $flagstring = ""; + } + + my $arglist = @$args ? "(" . (join ", ", @$args) . ")" : ""; + $hdr_data .= sprintf "#define %-62s %s\n", "CCS_R_" . (uc $name), $addr + if !@$args; + + $name =~ s/\(.*//; + + %this = ( name => $name, + addr => $addr, + flagstring => $flagstring, + base_addr => $base_addr, + argparams => {}, + args => $args, + arglist => $arglist, + elsize => $bits / 8, + ); + + if (!@$args) { + $reglist .= "\t{ CCS_R_" . (uc $name) . ", 1, 0, \"" . (lc $name) . "\", NULL },\n"; + print $H tabconv $hdr_data; + undef $hdr_data; + + print $LC tabconv sprintf "\t{ CCS_R_" . (uc $name) . ", " . + $this{elsize} . ", 0, \"$name\" },\n" + if is_limit_reg $this{base_addr}; + } + + print $LH tabconv sprintf "#define %-63s%s\n", + "CCS_L_" . (uc $this{name}), $limitcount++ + if is_limit_reg $this{base_addr}; +} + +if (defined $A) { + print $A $argdescs, $reglist; + + print $A "\t{ 0 }\n"; + + print $A "};\n"; +} + +print $H "\n#endif /* __${uc_header}__ */\n"; + +print $LH tabconv sprintf "#define %-63s%s\n", "CCS_L_LAST", $limitcount; + +print $LH "\n#endif /* __${uc_limith}__ */\n"; + +print $LC "\t{ 0 } /* Guardian */\n"; +print $LC "};\n"; + +close($R); +close($H); +close($A) if defined $A; +close($LC); +close($LH); diff --git a/Documentation/driver-api/media/drivers/contributors.rst b/Documentation/driver-api/media/drivers/contributors.rst new file mode 100644 index 000000000..f23b6e6fa --- /dev/null +++ b/Documentation/driver-api/media/drivers/contributors.rst @@ -0,0 +1,131 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Contributors +============ + +.. note:: + + This documentation is outdated. There are several other DVB contributors + that aren't listed below. + +Thanks go to the following people for patches and contributions: + +- Michael Hunold <m.hunold@gmx.de> + + - for the initial saa7146 driver and its recent overhaul + +- Christian Theiss + + - for his work on the initial Linux DVB driver + +- Marcus Metzler <mocm@metzlerbros.de> and + Ralph Metzler <rjkm@metzlerbros.de> + + - for their continuing work on the DVB driver + +- Michael Holzt <kju@debian.org> + + - for his contributions to the dvb-net driver + +- Diego Picciani <d.picciani@novacomp.it> + + - for CyberLogin for Linux which allows logging onto EON + (in case you are wondering where CyberLogin is, EON changed its login + procedure and CyberLogin is no longer used.) + +- Martin Schaller <martin@smurf.franken.de> + + - for patching the cable card decoder driver + +- Klaus Schmidinger <Klaus.Schmidinger@cadsoft.de> + + - for various fixes regarding tuning, OSD and CI stuff and his work on VDR + +- Steve Brown <sbrown@cortland.com> + + - for his AFC kernel thread + +- Christoph Martin <martin@uni-mainz.de> + + - for his LIRC infrared handler + +- Andreas Oberritter <obi@linuxtv.org>, + Dennis Noermann <dennis.noermann@noernet.de>, + Felix Domke <tmbinc@elitedvb.net>, + Florian Schirmer <jolt@tuxbox.org>, + Ronny Strutz <3des@elitedvb.de>, + Wolfram Joost <dbox2@frokaschwei.de> + and all the other dbox2 people + + - for many bugfixes in the generic DVB Core, frontend drivers and + their work on the dbox2 port of the DVB driver + +- Oliver Endriss <o.endriss@gmx.de> + + - for many bugfixes + +- Andrew de Quincey <adq_dvb@lidskialf.net> + + - for the tda1004x frontend driver, and various bugfixes + +- Peter Schildmann <peter.schildmann@web.de> + + - for the driver for the Technisat SkyStar2 PCI DVB card + +- Vadim Catana <skystar@moldova.cc>, + Roberto Ragusa <r.ragusa@libero.it> and + Augusto Cardoso <augusto@carhil.net> + + - for all the work for the FlexCopII chipset by B2C2,Inc. + +- Davor Emard <emard@softhome.net> + + - for his work on the budget drivers, the demux code, + the module unloading problems, ... + +- Hans-Frieder Vogt <hfvogt@arcor.de> + + - for his work on calculating and checking the crc's for the + TechnoTrend/Hauppauge DEC driver firmware + +- Michael Dreher <michael@5dot1.de> and + Andreas 'randy' Weinberger + + - for the support of the Fujitsu-Siemens Activy budget DVB-S + +- Kenneth Aafløy <ke-aa@frisurf.no> + + - for adding support for Typhoon DVB-S budget card + +- Ernst Peinlich <e.peinlich@inode.at> + + - for tuning/DiSEqC support for the DEC 3000-s + +- Peter Beutner <p.beutner@gmx.net> + + - for the IR code for the ttusb-dec driver + +- Wilson Michaels <wilsonmichaels@earthlink.net> + + - for the lgdt330x frontend driver, and various bugfixes + +- Michael Krufky <mkrufky@linuxtv.org> + + - for maintaining v4l/dvb inter-tree dependencies + +- Taylor Jacob <rtjacob@earthlink.net> + + - for the nxt2002 frontend driver + +- Jean-Francois Thibert <jeanfrancois@sagetv.com> + + - for the nxt2004 frontend driver + +- Kirk Lapray <kirk.lapray@gmail.com> + + - for the or51211 and or51132 frontend drivers, and + for merging the nxt2002 and nxt2004 modules into a + single nxt200x frontend driver. + +(If you think you should be in this list, but you are not, drop a +line to the DVB mailing list) diff --git a/Documentation/driver-api/media/drivers/cx2341x-devel.rst b/Documentation/driver-api/media/drivers/cx2341x-devel.rst new file mode 100644 index 000000000..97699df6e --- /dev/null +++ b/Documentation/driver-api/media/drivers/cx2341x-devel.rst @@ -0,0 +1,3685 @@ +.. SPDX-License-Identifier: GPL-2.0 + +The cx2341x driver +================== + +Memory at cx2341x chips +----------------------- + +This section describes the cx2341x memory map and documents some of the +register space. + +.. note:: the memory long words are little-endian ('intel format'). + +.. warning:: + + This information was figured out from searching through the memory + and registers, this information may not be correct and is certainly + not complete, and was not derived from anything more than searching + through the memory space with commands like: + + .. code-block:: none + + ivtvctl -O min=0x02000000,max=0x020000ff + + So take this as is, I'm always searching for more stuff, it's a large + register space :-). + +Memory Map +~~~~~~~~~~ + +The cx2341x exposes its entire 64M memory space to the PCI host via the PCI BAR0 +(Base Address Register 0). The addresses here are offsets relative to the +address held in BAR0. + +.. code-block:: none + + 0x00000000-0x00ffffff Encoder memory space + 0x00000000-0x0003ffff Encode.rom + ???-??? MPEG buffer(s) + ???-??? Raw video capture buffer(s) + ???-??? Raw audio capture buffer(s) + ???-??? Display buffers (6 or 9) + + 0x01000000-0x01ffffff Decoder memory space + 0x01000000-0x0103ffff Decode.rom + ???-??? MPEG buffers(s) + 0x0114b000-0x0115afff Audio.rom (deprecated?) + + 0x02000000-0x0200ffff Register Space + +Registers +~~~~~~~~~ + +The registers occupy the 64k space starting at the 0x02000000 offset from BAR0. +All of these registers are 32 bits wide. + +.. code-block:: none + + DMA Registers 0x000-0xff: + + 0x00 - Control: + 0=reset/cancel, 1=read, 2=write, 4=stop + 0x04 - DMA status: + 1=read busy, 2=write busy, 4=read error, 8=write error, 16=link list error + 0x08 - pci DMA pointer for read link list + 0x0c - pci DMA pointer for write link list + 0x10 - read/write DMA enable: + 1=read enable, 2=write enable + 0x14 - always 0xffffffff, if set any lower instability occurs, 0x00 crashes + 0x18 - ?? + 0x1c - always 0x20 or 32, smaller values slow down DMA transactions + 0x20 - always value of 0x780a010a + 0x24-0x3c - usually just random values??? + 0x40 - Interrupt status + 0x44 - Write a bit here and shows up in Interrupt status 0x40 + 0x48 - Interrupt Mask + 0x4C - always value of 0xfffdffff, + if changed to 0xffffffff DMA write interrupts break. + 0x50 - always 0xffffffff + 0x54 - always 0xffffffff (0x4c, 0x50, 0x54 seem like interrupt masks, are + 3 processors on chip, Java ones, VPU, SPU, APU, maybe these are the + interrupt masks???). + 0x60-0x7C - random values + 0x80 - first write linked list reg, for Encoder Memory addr + 0x84 - first write linked list reg, for pci memory addr + 0x88 - first write linked list reg, for length of buffer in memory addr + (|0x80000000 or this for last link) + 0x8c-0xdc - rest of write linked list reg, 8 sets of 3 total, DMA goes here + from linked list addr in reg 0x0c, firmware must push through or + something. + 0xe0 - first (and only) read linked list reg, for pci memory addr + 0xe4 - first (and only) read linked list reg, for Decoder memory addr + 0xe8 - first (and only) read linked list reg, for length of buffer + 0xec-0xff - Nothing seems to be in these registers, 0xec-f4 are 0x00000000. + +Memory locations for Encoder Buffers 0x700-0x7ff: + +These registers show offsets of memory locations pertaining to each +buffer area used for encoding, have to shift them by <<1 first. + +- 0x07F8: Encoder SDRAM refresh +- 0x07FC: Encoder SDRAM pre-charge + +Memory locations for Decoder Buffers 0x800-0x8ff: + +These registers show offsets of memory locations pertaining to each +buffer area used for decoding, have to shift them by <<1 first. + +- 0x08F8: Decoder SDRAM refresh +- 0x08FC: Decoder SDRAM pre-charge + +Other memory locations: + +- 0x2800: Video Display Module control +- 0x2D00: AO (audio output?) control +- 0x2D24: Bytes Flushed +- 0x7000: LSB I2C write clock bit (inverted) +- 0x7004: LSB I2C write data bit (inverted) +- 0x7008: LSB I2C read clock bit +- 0x700c: LSB I2C read data bit +- 0x9008: GPIO get input state +- 0x900c: GPIO set output state +- 0x9020: GPIO direction (Bit7 (GPIO 0..7) - 0:input, 1:output) +- 0x9050: SPU control +- 0x9054: Reset HW blocks +- 0x9058: VPU control +- 0xA018: Bit6: interrupt pending? +- 0xA064: APU command + + +Interrupt Status Register +~~~~~~~~~~~~~~~~~~~~~~~~~ + +The definition of the bits in the interrupt status register 0x0040, and the +interrupt mask 0x0048. If a bit is cleared in the mask, then we want our ISR to +execute. + +- bit 31 Encoder Start Capture +- bit 30 Encoder EOS +- bit 29 Encoder VBI capture +- bit 28 Encoder Video Input Module reset event +- bit 27 Encoder DMA complete +- bit 24 Decoder audio mode change detection event (through event notification) +- bit 22 Decoder data request +- bit 20 Decoder DMA complete +- bit 19 Decoder VBI re-insertion +- bit 18 Decoder DMA err (linked-list bad) + +Missing documentation +--------------------- + +- Encoder API post(?) +- Decoder API post(?) +- Decoder VTRACE event + + +The cx2341x firmware upload +--------------------------- + +This document describes how to upload the cx2341x firmware to the card. + +How to find +~~~~~~~~~~~ + +See the web pages of the various projects that uses this chip for information +on how to obtain the firmware. + +The firmware stored in a Windows driver can be detected as follows: + +- Each firmware image is 256k bytes. +- The 1st 32-bit word of the Encoder image is 0x0000da7 +- The 1st 32-bit word of the Decoder image is 0x00003a7 +- The 2nd 32-bit word of both images is 0xaa55bb66 + +How to load +~~~~~~~~~~~ + +- Issue the FWapi command to stop the encoder if it is running. Wait for the + command to complete. +- Issue the FWapi command to stop the decoder if it is running. Wait for the + command to complete. +- Issue the I2C command to the digitizer to stop emitting VSYNC events. +- Issue the FWapi command to halt the encoder's firmware. +- Sleep for 10ms. +- Issue the FWapi command to halt the decoder's firmware. +- Sleep for 10ms. +- Write 0x00000000 to register 0x2800 to stop the Video Display Module. +- Write 0x00000005 to register 0x2D00 to stop the AO (audio output?). +- Write 0x00000000 to register 0xA064 to ping? the APU. +- Write 0xFFFFFFFE to register 0x9058 to stop the VPU. +- Write 0xFFFFFFFF to register 0x9054 to reset the HW blocks. +- Write 0x00000001 to register 0x9050 to stop the SPU. +- Sleep for 10ms. +- Write 0x0000001A to register 0x07FC to init the Encoder SDRAM's pre-charge. +- Write 0x80000640 to register 0x07F8 to init the Encoder SDRAM's refresh to 1us. +- Write 0x0000001A to register 0x08FC to init the Decoder SDRAM's pre-charge. +- Write 0x80000640 to register 0x08F8 to init the Decoder SDRAM's refresh to 1us. +- Sleep for 512ms. (600ms is recommended) +- Transfer the encoder's firmware image to offset 0 in Encoder memory space. +- Transfer the decoder's firmware image to offset 0 in Decoder memory space. +- Use a read-modify-write operation to Clear bit 0 of register 0x9050 to + re-enable the SPU. +- Sleep for 1 second. +- Use a read-modify-write operation to Clear bits 3 and 0 of register 0x9058 + to re-enable the VPU. +- Sleep for 1 second. +- Issue status API commands to both firmware images to verify. + + +How to call the firmware API +---------------------------- + +The preferred calling convention is known as the firmware mailbox. The +mailboxes are basically a fixed length array that serves as the call-stack. + +Firmware mailboxes can be located by searching the encoder and decoder memory +for a 16 byte signature. That signature will be located on a 256-byte boundary. + +Signature: + +.. code-block:: none + + 0x78, 0x56, 0x34, 0x12, 0x12, 0x78, 0x56, 0x34, + 0x34, 0x12, 0x78, 0x56, 0x56, 0x34, 0x12, 0x78 + +The firmware implements 20 mailboxes of 20 32-bit words. The first 10 are +reserved for API calls. The second 10 are used by the firmware for event +notification. + + ====== ================= + Index Name + ====== ================= + 0 Flags + 1 Command + 2 Return value + 3 Timeout + 4-19 Parameter/Result + ====== ================= + + +The flags are defined in the following table. The direction is from the +perspective of the firmware. + + ==== ========== ============================================ + Bit Direction Purpose + ==== ========== ============================================ + 2 O Firmware has processed the command. + 1 I Driver has finished setting the parameters. + 0 I Driver is using this mailbox. + ==== ========== ============================================ + +The command is a 32-bit enumerator. The API specifics may be found in this +chapter. + +The return value is a 32-bit enumerator. Only two values are currently defined: + +- 0=success +- -1=command undefined. + +There are 16 parameters/results 32-bit fields. The driver populates these fields +with values for all the parameters required by the call. The driver overwrites +these fields with result values returned by the call. + +The timeout value protects the card from a hung driver thread. If the driver +doesn't handle the completed call within the timeout specified, the firmware +will reset that mailbox. + +To make an API call, the driver iterates over each mailbox looking for the +first one available (bit 0 has been cleared). The driver sets that bit, fills +in the command enumerator, the timeout value and any required parameters. The +driver then sets the parameter ready bit (bit 1). The firmware scans the +mailboxes for pending commands, processes them, sets the result code, populates +the result value array with that call's return values and sets the call +complete bit (bit 2). Once bit 2 is set, the driver should retrieve the results +and clear all the flags. If the driver does not perform this task within the +time set in the timeout register, the firmware will reset that mailbox. + +Event notifications are sent from the firmware to the host. The host tells the +firmware which events it is interested in via an API call. That call tells the +firmware which notification mailbox to use. The firmware signals the host via +an interrupt. Only the 16 Results fields are used, the Flags, Command, Return +value and Timeout words are not used. + + +OSD firmware API description +---------------------------- + +.. note:: this API is part of the decoder firmware, so it's cx23415 only. + + + +CX2341X_OSD_GET_FRAMEBUFFER +~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 65/0x41 + +Description +^^^^^^^^^^^ + +Return base and length of contiguous OSD memory. + +Result[0] +^^^^^^^^^ + +OSD base address + +Result[1] +^^^^^^^^^ + +OSD length + + + +CX2341X_OSD_GET_PIXEL_FORMAT +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 66/0x42 + +Description +^^^^^^^^^^^ + +Query OSD format + +Result[0] +^^^^^^^^^ + +0=8bit index +1=16bit RGB 5:6:5 +2=16bit ARGB 1:5:5:5 +3=16bit ARGB 1:4:4:4 +4=32bit ARGB 8:8:8:8 + + + +CX2341X_OSD_SET_PIXEL_FORMAT +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 67/0x43 + +Description +^^^^^^^^^^^ + +Assign pixel format + +Param[0] +^^^^^^^^ + +- 0=8bit index +- 1=16bit RGB 5:6:5 +- 2=16bit ARGB 1:5:5:5 +- 3=16bit ARGB 1:4:4:4 +- 4=32bit ARGB 8:8:8:8 + + + +CX2341X_OSD_GET_STATE +~~~~~~~~~~~~~~~~~~~~~ + +Enum: 68/0x44 + +Description +^^^^^^^^^^^ + +Query OSD state + +Result[0] +^^^^^^^^^ + +- Bit 0 0=off, 1=on +- Bits 1:2 alpha control +- Bits 3:5 pixel format + + + +CX2341X_OSD_SET_STATE +~~~~~~~~~~~~~~~~~~~~~ + +Enum: 69/0x45 + +Description +^^^^^^^^^^^ + +OSD switch + +Param[0] +^^^^^^^^ + +0=off, 1=on + + + +CX2341X_OSD_GET_OSD_COORDS +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 70/0x46 + +Description +^^^^^^^^^^^ + +Retrieve coordinates of OSD area blended with video + +Result[0] +^^^^^^^^^ + +OSD buffer address + +Result[1] +^^^^^^^^^ + +Stride in pixels + +Result[2] +^^^^^^^^^ + +Lines in OSD buffer + +Result[3] +^^^^^^^^^ + +Horizontal offset in buffer + +Result[4] +^^^^^^^^^ + +Vertical offset in buffer + + + +CX2341X_OSD_SET_OSD_COORDS +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 71/0x47 + +Description +^^^^^^^^^^^ + +Assign the coordinates of the OSD area to blend with video + +Param[0] +^^^^^^^^ + +buffer address + +Param[1] +^^^^^^^^ + +buffer stride in pixels + +Param[2] +^^^^^^^^ + +lines in buffer + +Param[3] +^^^^^^^^ + +horizontal offset + +Param[4] +^^^^^^^^ + +vertical offset + + + +CX2341X_OSD_GET_SCREEN_COORDS +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 72/0x48 + +Description +^^^^^^^^^^^ + +Retrieve OSD screen area coordinates + +Result[0] +^^^^^^^^^ + +top left horizontal offset + +Result[1] +^^^^^^^^^ + +top left vertical offset + +Result[2] +^^^^^^^^^ + +bottom right horizontal offset + +Result[3] +^^^^^^^^^ + +bottom right vertical offset + + + +CX2341X_OSD_SET_SCREEN_COORDS +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 73/0x49 + +Description +^^^^^^^^^^^ + +Assign the coordinates of the screen area to blend with video + +Param[0] +^^^^^^^^ + +top left horizontal offset + +Param[1] +^^^^^^^^ + +top left vertical offset + +Param[2] +^^^^^^^^ + +bottom left horizontal offset + +Param[3] +^^^^^^^^ + +bottom left vertical offset + + + +CX2341X_OSD_GET_GLOBAL_ALPHA +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 74/0x4A + +Description +^^^^^^^^^^^ + +Retrieve OSD global alpha + +Result[0] +^^^^^^^^^ + +global alpha: 0=off, 1=on + +Result[1] +^^^^^^^^^ + +bits 0:7 global alpha + + + +CX2341X_OSD_SET_GLOBAL_ALPHA +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 75/0x4B + +Description +^^^^^^^^^^^ + +Update global alpha + +Param[0] +^^^^^^^^ + +global alpha: 0=off, 1=on + +Param[1] +^^^^^^^^ + +global alpha (8 bits) + +Param[2] +^^^^^^^^ + +local alpha: 0=on, 1=off + + + +CX2341X_OSD_SET_BLEND_COORDS +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 78/0x4C + +Description +^^^^^^^^^^^ + +Move start of blending area within display buffer + +Param[0] +^^^^^^^^ + +horizontal offset in buffer + +Param[1] +^^^^^^^^ + +vertical offset in buffer + + + +CX2341X_OSD_GET_FLICKER_STATE +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 79/0x4F + +Description +^^^^^^^^^^^ + +Retrieve flicker reduction module state + +Result[0] +^^^^^^^^^ + +flicker state: 0=off, 1=on + + + +CX2341X_OSD_SET_FLICKER_STATE +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 80/0x50 + +Description +^^^^^^^^^^^ + +Set flicker reduction module state + +Param[0] +^^^^^^^^ + +State: 0=off, 1=on + + + +CX2341X_OSD_BLT_COPY +~~~~~~~~~~~~~~~~~~~~ + +Enum: 82/0x52 + +Description +^^^^^^^^^^^ + +BLT copy + +Param[0] +^^^^^^^^ + +.. code-block:: none + + '0000' zero + '0001' ~destination AND ~source + '0010' ~destination AND source + '0011' ~destination + '0100' destination AND ~source + '0101' ~source + '0110' destination XOR source + '0111' ~destination OR ~source + '1000' ~destination AND ~source + '1001' destination XNOR source + '1010' source + '1011' ~destination OR source + '1100' destination + '1101' destination OR ~source + '1110' destination OR source + '1111' one + + +Param[1] +^^^^^^^^ + +Resulting alpha blending + +- '01' source_alpha +- '10' destination_alpha +- '11' source_alpha*destination_alpha+1 + (zero if both source and destination alpha are zero) + +Param[2] +^^^^^^^^ + +.. code-block:: none + + '00' output_pixel = source_pixel + + '01' if source_alpha=0: + output_pixel = destination_pixel + if 256 > source_alpha > 1: + output_pixel = ((source_alpha + 1)*source_pixel + + (255 - source_alpha)*destination_pixel)/256 + + '10' if destination_alpha=0: + output_pixel = source_pixel + if 255 > destination_alpha > 0: + output_pixel = ((255 - destination_alpha)*source_pixel + + (destination_alpha + 1)*destination_pixel)/256 + + '11' if source_alpha=0: + source_temp = 0 + if source_alpha=255: + source_temp = source_pixel*256 + if 255 > source_alpha > 0: + source_temp = source_pixel*(source_alpha + 1) + if destination_alpha=0: + destination_temp = 0 + if destination_alpha=255: + destination_temp = destination_pixel*256 + if 255 > destination_alpha > 0: + destination_temp = destination_pixel*(destination_alpha + 1) + output_pixel = (source_temp + destination_temp)/256 + +Param[3] +^^^^^^^^ + +width + +Param[4] +^^^^^^^^ + +height + +Param[5] +^^^^^^^^ + +destination pixel mask + +Param[6] +^^^^^^^^ + +destination rectangle start address + +Param[7] +^^^^^^^^ + +destination stride in dwords + +Param[8] +^^^^^^^^ + +source stride in dwords + +Param[9] +^^^^^^^^ + +source rectangle start address + + + +CX2341X_OSD_BLT_FILL +~~~~~~~~~~~~~~~~~~~~ + +Enum: 83/0x53 + +Description +^^^^^^^^^^^ + +BLT fill color + +Param[0] +^^^^^^^^ + +Same as Param[0] on API 0x52 + +Param[1] +^^^^^^^^ + +Same as Param[1] on API 0x52 + +Param[2] +^^^^^^^^ + +Same as Param[2] on API 0x52 + +Param[3] +^^^^^^^^ + +width + +Param[4] +^^^^^^^^ + +height + +Param[5] +^^^^^^^^ + +destination pixel mask + +Param[6] +^^^^^^^^ + +destination rectangle start address + +Param[7] +^^^^^^^^ + +destination stride in dwords + +Param[8] +^^^^^^^^ + +color fill value + + + +CX2341X_OSD_BLT_TEXT +~~~~~~~~~~~~~~~~~~~~ + +Enum: 84/0x54 + +Description +^^^^^^^^^^^ + +BLT for 8 bit alpha text source + +Param[0] +^^^^^^^^ + +Same as Param[0] on API 0x52 + +Param[1] +^^^^^^^^ + +Same as Param[1] on API 0x52 + +Param[2] +^^^^^^^^ + +Same as Param[2] on API 0x52 + +Param[3] +^^^^^^^^ + +width + +Param[4] +^^^^^^^^ + +height + +Param[5] +^^^^^^^^ + +destination pixel mask + +Param[6] +^^^^^^^^ + +destination rectangle start address + +Param[7] +^^^^^^^^ + +destination stride in dwords + +Param[8] +^^^^^^^^ + +source stride in dwords + +Param[9] +^^^^^^^^ + +source rectangle start address + +Param[10] +^^^^^^^^^ + +color fill value + + + +CX2341X_OSD_SET_FRAMEBUFFER_WINDOW +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 86/0x56 + +Description +^^^^^^^^^^^ + +Positions the main output window on the screen. The coordinates must be +such that the entire window fits on the screen. + +Param[0] +^^^^^^^^ + +window width + +Param[1] +^^^^^^^^ + +window height + +Param[2] +^^^^^^^^ + +top left window corner horizontal offset + +Param[3] +^^^^^^^^ + +top left window corner vertical offset + + + +CX2341X_OSD_SET_CHROMA_KEY +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 96/0x60 + +Description +^^^^^^^^^^^ + +Chroma key switch and color + +Param[0] +^^^^^^^^ + +state: 0=off, 1=on + +Param[1] +^^^^^^^^ + +color + + + +CX2341X_OSD_GET_ALPHA_CONTENT_INDEX +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 97/0x61 + +Description +^^^^^^^^^^^ + +Retrieve alpha content index + +Result[0] +^^^^^^^^^ + +alpha content index, Range 0:15 + + + +CX2341X_OSD_SET_ALPHA_CONTENT_INDEX +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 98/0x62 + +Description +^^^^^^^^^^^ + +Assign alpha content index + +Param[0] +^^^^^^^^ + +alpha content index, range 0:15 + + +Encoder firmware API description +-------------------------------- + +CX2341X_ENC_PING_FW +~~~~~~~~~~~~~~~~~~~ + +Enum: 128/0x80 + +Description +^^^^^^^^^^^ + +Does nothing. Can be used to check if the firmware is responding. + + + +CX2341X_ENC_START_CAPTURE +~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 129/0x81 + +Description +^^^^^^^^^^^ + +Commences the capture of video, audio and/or VBI data. All encoding +parameters must be initialized prior to this API call. Captures frames +continuously or until a predefined number of frames have been captured. + +Param[0] +^^^^^^^^ + +Capture stream type: + + - 0=MPEG + - 1=Raw + - 2=Raw passthrough + - 3=VBI + + +Param[1] +^^^^^^^^ + +Bitmask: + + - Bit 0 when set, captures YUV + - Bit 1 when set, captures PCM audio + - Bit 2 when set, captures VBI (same as param[0]=3) + - Bit 3 when set, the capture destination is the decoder + (same as param[0]=2) + - Bit 4 when set, the capture destination is the host + +.. note:: this parameter is only meaningful for RAW capture type. + + + +CX2341X_ENC_STOP_CAPTURE +~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 130/0x82 + +Description +^^^^^^^^^^^ + +Ends a capture in progress + +Param[0] +^^^^^^^^ + +- 0=stop at end of GOP (generates IRQ) +- 1=stop immediate (no IRQ) + +Param[1] +^^^^^^^^ + +Stream type to stop, see param[0] of API 0x81 + +Param[2] +^^^^^^^^ + +Subtype, see param[1] of API 0x81 + + + +CX2341X_ENC_SET_AUDIO_ID +~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 137/0x89 + +Description +^^^^^^^^^^^ + +Assigns the transport stream ID of the encoded audio stream + +Param[0] +^^^^^^^^ + +Audio Stream ID + + + +CX2341X_ENC_SET_VIDEO_ID +~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 139/0x8B + +Description +^^^^^^^^^^^ + +Set video transport stream ID + +Param[0] +^^^^^^^^ + +Video stream ID + + + +CX2341X_ENC_SET_PCR_ID +~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 141/0x8D + +Description +^^^^^^^^^^^ + +Assigns the transport stream ID for PCR packets + +Param[0] +^^^^^^^^ + +PCR Stream ID + + + +CX2341X_ENC_SET_FRAME_RATE +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 143/0x8F + +Description +^^^^^^^^^^^ + +Set video frames per second. Change occurs at start of new GOP. + +Param[0] +^^^^^^^^ + +- 0=30fps +- 1=25fps + + + +CX2341X_ENC_SET_FRAME_SIZE +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 145/0x91 + +Description +^^^^^^^^^^^ + +Select video stream encoding resolution. + +Param[0] +^^^^^^^^ + +Height in lines. Default 480 + +Param[1] +^^^^^^^^ + +Width in pixels. Default 720 + + + +CX2341X_ENC_SET_BIT_RATE +~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 149/0x95 + +Description +^^^^^^^^^^^ + +Assign average video stream bitrate. + +Param[0] +^^^^^^^^ + +0=variable bitrate, 1=constant bitrate + +Param[1] +^^^^^^^^ + +bitrate in bits per second + +Param[2] +^^^^^^^^ + +peak bitrate in bits per second, divided by 400 + +Param[3] +^^^^^^^^ + +Mux bitrate in bits per second, divided by 400. May be 0 (default). + +Param[4] +^^^^^^^^ + +Rate Control VBR Padding + +Param[5] +^^^^^^^^ + +VBV Buffer used by encoder + +.. note:: + + #) Param\[3\] and Param\[4\] seem to be always 0 + #) Param\[5\] doesn't seem to be used. + + + +CX2341X_ENC_SET_GOP_PROPERTIES +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 151/0x97 + +Description +^^^^^^^^^^^ + +Setup the GOP structure + +Param[0] +^^^^^^^^ + +GOP size (maximum is 34) + +Param[1] +^^^^^^^^ + +Number of B frames between the I and P frame, plus 1. +For example: IBBPBBPBBPBB --> GOP size: 12, number of B frames: 2+1 = 3 + +.. note:: + + GOP size must be a multiple of (B-frames + 1). + + + +CX2341X_ENC_SET_ASPECT_RATIO +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 153/0x99 + +Description +^^^^^^^^^^^ + +Sets the encoding aspect ratio. Changes in the aspect ratio take effect +at the start of the next GOP. + +Param[0] +^^^^^^^^ + +- '0000' forbidden +- '0001' 1:1 square +- '0010' 4:3 +- '0011' 16:9 +- '0100' 2.21:1 +- '0101' to '1111' reserved + + + +CX2341X_ENC_SET_DNR_FILTER_MODE +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 155/0x9B + +Description +^^^^^^^^^^^ + +Assign Dynamic Noise Reduction operating mode + +Param[0] +^^^^^^^^ + +Bit0: Spatial filter, set=auto, clear=manual +Bit1: Temporal filter, set=auto, clear=manual + +Param[1] +^^^^^^^^ + +Median filter: + +- 0=Disabled +- 1=Horizontal +- 2=Vertical +- 3=Horiz/Vert +- 4=Diagonal + + + +CX2341X_ENC_SET_DNR_FILTER_PROPS +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 157/0x9D + +Description +^^^^^^^^^^^ + +These Dynamic Noise Reduction filter values are only meaningful when +the respective filter is set to "manual" (See API 0x9B) + +Param[0] +^^^^^^^^ + +Spatial filter: default 0, range 0:15 + +Param[1] +^^^^^^^^ + +Temporal filter: default 0, range 0:31 + + + +CX2341X_ENC_SET_CORING_LEVELS +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 159/0x9F + +Description +^^^^^^^^^^^ + +Assign Dynamic Noise Reduction median filter properties. + +Param[0] +^^^^^^^^ + +Threshold above which the luminance median filter is enabled. +Default: 0, range 0:255 + +Param[1] +^^^^^^^^ + +Threshold below which the luminance median filter is enabled. +Default: 255, range 0:255 + +Param[2] +^^^^^^^^ + +Threshold above which the chrominance median filter is enabled. +Default: 0, range 0:255 + +Param[3] +^^^^^^^^ + +Threshold below which the chrominance median filter is enabled. +Default: 255, range 0:255 + + + +CX2341X_ENC_SET_SPATIAL_FILTER_TYPE +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 161/0xA1 + +Description +^^^^^^^^^^^ + +Assign spatial prefilter parameters + +Param[0] +^^^^^^^^ + +Luminance filter + +- 0=Off +- 1=1D Horizontal +- 2=1D Vertical +- 3=2D H/V Separable (default) +- 4=2D Symmetric non-separable + +Param[1] +^^^^^^^^ + +Chrominance filter + +- 0=Off +- 1=1D Horizontal (default) + + + +CX2341X_ENC_SET_VBI_LINE +~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 183/0xB7 + +Description +^^^^^^^^^^^ + +Selects VBI line number. + +Param[0] +^^^^^^^^ + +- Bits 0:4 line number +- Bit 31 0=top_field, 1=bottom_field +- Bits 0:31 all set specifies "all lines" + +Param[1] +^^^^^^^^ + +VBI line information features: 0=disabled, 1=enabled + +Param[2] +^^^^^^^^ + +Slicing: 0=None, 1=Closed Caption +Almost certainly not implemented. Set to 0. + +Param[3] +^^^^^^^^ + +Luminance samples in this line. +Almost certainly not implemented. Set to 0. + +Param[4] +^^^^^^^^ + +Chrominance samples in this line +Almost certainly not implemented. Set to 0. + + + +CX2341X_ENC_SET_STREAM_TYPE +~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 185/0xB9 + +Description +^^^^^^^^^^^ + +Assign stream type + +.. note:: + + Transport stream is not working in recent firmwares. + And in older firmwares the timestamps in the TS seem to be + unreliable. + +Param[0] +^^^^^^^^ + +- 0=Program stream +- 1=Transport stream +- 2=MPEG1 stream +- 3=PES A/V stream +- 5=PES Video stream +- 7=PES Audio stream +- 10=DVD stream +- 11=VCD stream +- 12=SVCD stream +- 13=DVD_S1 stream +- 14=DVD_S2 stream + + + +CX2341X_ENC_SET_OUTPUT_PORT +~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 187/0xBB + +Description +^^^^^^^^^^^ + +Assign stream output port. Normally 0 when the data is copied through +the PCI bus (DMA), and 1 when the data is streamed to another chip +(pvrusb and cx88-blackbird). + +Param[0] +^^^^^^^^ + +- 0=Memory (default) +- 1=Streaming +- 2=Serial + +Param[1] +^^^^^^^^ + +Unknown, but leaving this to 0 seems to work best. Indications are that +this might have to do with USB support, although passing anything but 0 +only breaks things. + + + +CX2341X_ENC_SET_AUDIO_PROPERTIES +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 189/0xBD + +Description +^^^^^^^^^^^ + +Set audio stream properties, may be called while encoding is in progress. + +.. note:: + + All bitfields are consistent with ISO11172 documentation except + bits 2:3 which ISO docs define as: + + - '11' Layer I + - '10' Layer II + - '01' Layer III + - '00' Undefined + + This discrepancy may indicate a possible error in the documentation. + Testing indicated that only Layer II is actually working, and that + the minimum bitrate should be 192 kbps. + +Param[0] +^^^^^^^^ + +Bitmask: + +.. code-block:: none + + 0:1 '00' 44.1Khz + '01' 48Khz + '10' 32Khz + '11' reserved + + 2:3 '01'=Layer I + '10'=Layer II + + 4:7 Bitrate: + Index | Layer I | Layer II + ------+-------------+------------ + '0000' | free format | free format + '0001' | 32 kbit/s | 32 kbit/s + '0010' | 64 kbit/s | 48 kbit/s + '0011' | 96 kbit/s | 56 kbit/s + '0100' | 128 kbit/s | 64 kbit/s + '0101' | 160 kbit/s | 80 kbit/s + '0110' | 192 kbit/s | 96 kbit/s + '0111' | 224 kbit/s | 112 kbit/s + '1000' | 256 kbit/s | 128 kbit/s + '1001' | 288 kbit/s | 160 kbit/s + '1010' | 320 kbit/s | 192 kbit/s + '1011' | 352 kbit/s | 224 kbit/s + '1100' | 384 kbit/s | 256 kbit/s + '1101' | 416 kbit/s | 320 kbit/s + '1110' | 448 kbit/s | 384 kbit/s + + .. note:: + + For Layer II, not all combinations of total bitrate + and mode are allowed. See ISO11172-3 3-Annex B, + Table 3-B.2 + + 8:9 '00'=Stereo + '01'=JointStereo + '10'=Dual + '11'=Mono + + .. note:: + + The cx23415 cannot decode Joint Stereo properly. + + 10:11 Mode Extension used in joint_stereo mode. + In Layer I and II they indicate which subbands are in + intensity_stereo. All other subbands are coded in stereo. + '00' subbands 4-31 in intensity_stereo, bound==4 + '01' subbands 8-31 in intensity_stereo, bound==8 + '10' subbands 12-31 in intensity_stereo, bound==12 + '11' subbands 16-31 in intensity_stereo, bound==16 + + 12:13 Emphasis: + '00' None + '01' 50/15uS + '10' reserved + '11' CCITT J.17 + + 14 CRC: + '0' off + '1' on + + 15 Copyright: + '0' off + '1' on + + 16 Generation: + '0' copy + '1' original + + + +CX2341X_ENC_HALT_FW +~~~~~~~~~~~~~~~~~~~ + +Enum: 195/0xC3 + +Description +^^^^^^^^^^^ + +The firmware is halted and no further API calls are serviced until the +firmware is uploaded again. + + + +CX2341X_ENC_GET_VERSION +~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 196/0xC4 + +Description +^^^^^^^^^^^ + +Returns the version of the encoder firmware. + +Result[0] +^^^^^^^^^ + +Version bitmask: +- Bits 0:15 build +- Bits 16:23 minor +- Bits 24:31 major + + + +CX2341X_ENC_SET_GOP_CLOSURE +~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 197/0xC5 + +Description +^^^^^^^^^^^ + +Assigns the GOP open/close property. + +Param[0] +^^^^^^^^ + +- 0=Open +- 1=Closed + + + +CX2341X_ENC_GET_SEQ_END +~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 198/0xC6 + +Description +^^^^^^^^^^^ + +Obtains the sequence end code of the encoder's buffer. When a capture +is started a number of interrupts are still generated, the last of +which will have Result[0] set to 1 and Result[1] will contain the size +of the buffer. + +Result[0] +^^^^^^^^^ + +State of the transfer (1 if last buffer) + +Result[1] +^^^^^^^^^ + +If Result[0] is 1, this contains the size of the last buffer, undefined +otherwise. + + + +CX2341X_ENC_SET_PGM_INDEX_INFO +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 199/0xC7 + +Description +^^^^^^^^^^^ + +Sets the Program Index Information. +The information is stored as follows: + +.. code-block:: c + + struct info { + u32 length; // Length of this frame + u32 offset_low; // Offset in the file of the + u32 offset_high; // start of this frame + u32 mask1; // Bits 0-2 are the type mask: + // 1=I, 2=P, 4=B + // 0=End of Program Index, other fields + // are invalid. + u32 pts; // The PTS of the frame + u32 mask2; // Bit 0 is bit 32 of the pts. + }; + u32 table_ptr; + struct info index[400]; + +The table_ptr is the encoder memory address in the table were +*new* entries will be written. + +.. note:: This is a ringbuffer, so the table_ptr will wraparound. + +Param[0] +^^^^^^^^ + +Picture Mask: +- 0=No index capture +- 1=I frames +- 3=I,P frames +- 7=I,P,B frames + +(Seems to be ignored, it always indexes I, P and B frames) + +Param[1] +^^^^^^^^ + +Elements requested (up to 400) + +Result[0] +^^^^^^^^^ + +Offset in the encoder memory of the start of the table. + +Result[1] +^^^^^^^^^ + +Number of allocated elements up to a maximum of Param[1] + + + +CX2341X_ENC_SET_VBI_CONFIG +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 200/0xC8 + +Description +^^^^^^^^^^^ + +Configure VBI settings + +Param[0] +^^^^^^^^ + +Bitmap: + +.. code-block:: none + + 0 Mode '0' Sliced, '1' Raw + 1:3 Insertion: + '000' insert in extension & user data + '001' insert in private packets + '010' separate stream and user data + '111' separate stream and private data + 8:15 Stream ID (normally 0xBD) + +Param[1] +^^^^^^^^ + +Frames per interrupt (max 8). Only valid in raw mode. + +Param[2] +^^^^^^^^ + +Total raw VBI frames. Only valid in raw mode. + +Param[3] +^^^^^^^^ + +Start codes + +Param[4] +^^^^^^^^ + +Stop codes + +Param[5] +^^^^^^^^ + +Lines per frame + +Param[6] +^^^^^^^^ + +Byte per line + +Result[0] +^^^^^^^^^ + +Observed frames per interrupt in raw mode only. Rage 1 to Param[1] + +Result[1] +^^^^^^^^^ + +Observed number of frames in raw mode. Range 1 to Param[2] + +Result[2] +^^^^^^^^^ + +Memory offset to start or raw VBI data + + + +CX2341X_ENC_SET_DMA_BLOCK_SIZE +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 201/0xC9 + +Description +^^^^^^^^^^^ + +Set DMA transfer block size + +Param[0] +^^^^^^^^ + +DMA transfer block size in bytes or frames. When unit is bytes, +supported block sizes are 2^7, 2^8 and 2^9 bytes. + +Param[1] +^^^^^^^^ + +Unit: 0=bytes, 1=frames + + + +CX2341X_ENC_GET_PREV_DMA_INFO_MB_10 +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 202/0xCA + +Description +^^^^^^^^^^^ + +Returns information on the previous DMA transfer in conjunction with +bit 27 of the interrupt mask. Uses mailbox 10. + +Result[0] +^^^^^^^^^ + +Type of stream + +Result[1] +^^^^^^^^^ + +Address Offset + +Result[2] +^^^^^^^^^ + +Maximum size of transfer + + + +CX2341X_ENC_GET_PREV_DMA_INFO_MB_9 +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 203/0xCB + +Description +^^^^^^^^^^^ + +Returns information on the previous DMA transfer in conjunction with +bit 27 or 18 of the interrupt mask. Uses mailbox 9. + +Result[0] +^^^^^^^^^ + +Status bits: +- 0 read completed +- 1 write completed +- 2 DMA read error +- 3 DMA write error +- 4 Scatter-Gather array error + +Result[1] +^^^^^^^^^ + +DMA type + +Result[2] +^^^^^^^^^ + +Presentation Time Stamp bits 0..31 + +Result[3] +^^^^^^^^^ + +Presentation Time Stamp bit 32 + + + +CX2341X_ENC_SCHED_DMA_TO_HOST +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 204/0xCC + +Description +^^^^^^^^^^^ + +Setup DMA to host operation + +Param[0] +^^^^^^^^ + +Memory address of link list + +Param[1] +^^^^^^^^ + +Length of link list (wtf: what units ???) + +Param[2] +^^^^^^^^ + +DMA type (0=MPEG) + + + +CX2341X_ENC_INITIALIZE_INPUT +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 205/0xCD + +Description +^^^^^^^^^^^ + +Initializes the video input + + + +CX2341X_ENC_SET_FRAME_DROP_RATE +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 208/0xD0 + +Description +^^^^^^^^^^^ + +For each frame captured, skip specified number of frames. + +Param[0] +^^^^^^^^ + +Number of frames to skip + + + +CX2341X_ENC_PAUSE_ENCODER +~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 210/0xD2 + +Description +^^^^^^^^^^^ + +During a pause condition, all frames are dropped instead of being encoded. + +Param[0] +^^^^^^^^ + +- 0=Pause encoding +- 1=Continue encoding + + + +CX2341X_ENC_REFRESH_INPUT +~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 211/0xD3 + +Description +^^^^^^^^^^^ + +Refreshes the video input + + + +CX2341X_ENC_SET_COPYRIGHT +~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 212/0xD4 + +Description +^^^^^^^^^^^ + +Sets stream copyright property + +Param[0] +^^^^^^^^ + + +- 0=Stream is not copyrighted +- 1=Stream is copyrighted + + + +CX2341X_ENC_SET_EVENT_NOTIFICATION +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 213/0xD5 + +Description +^^^^^^^^^^^ + +Setup firmware to notify the host about a particular event. Host must +unmask the interrupt bit. + +Param[0] +^^^^^^^^ + +Event (0=refresh encoder input) + +Param[1] +^^^^^^^^ + +Notification 0=disabled 1=enabled + +Param[2] +^^^^^^^^ + +Interrupt bit + +Param[3] +^^^^^^^^ + +Mailbox slot, -1 if no mailbox required. + + + +CX2341X_ENC_SET_NUM_VSYNC_LINES +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 214/0xD6 + +Description +^^^^^^^^^^^ + +Depending on the analog video decoder used, this assigns the number +of lines for field 1 and 2. + +Param[0] +^^^^^^^^ + +Field 1 number of lines: +- 0x00EF for SAA7114 +- 0x00F0 for SAA7115 +- 0x0105 for Micronas + +Param[1] +^^^^^^^^ + +Field 2 number of lines: +- 0x00EF for SAA7114 +- 0x00F0 for SAA7115 +- 0x0106 for Micronas + + + +CX2341X_ENC_SET_PLACEHOLDER +~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 215/0xD7 + +Description +^^^^^^^^^^^ + +Provides a mechanism of inserting custom user data in the MPEG stream. + +Param[0] +^^^^^^^^ + +- 0=extension & user data +- 1=private packet with stream ID 0xBD + +Param[1] +^^^^^^^^ + +Rate at which to insert data, in units of frames (for private packet) +or GOPs (for ext. & user data) + +Param[2] +^^^^^^^^ + +Number of data DWORDs (below) to insert + +Param[3] +^^^^^^^^ + +Custom data 0 + +Param[4] +^^^^^^^^ + +Custom data 1 + +Param[5] +^^^^^^^^ + +Custom data 2 + +Param[6] +^^^^^^^^ + +Custom data 3 + +Param[7] +^^^^^^^^ + +Custom data 4 + +Param[8] +^^^^^^^^ + +Custom data 5 + +Param[9] +^^^^^^^^ + +Custom data 6 + +Param[10] +^^^^^^^^^ + +Custom data 7 + +Param[11] +^^^^^^^^^ + +Custom data 8 + + + +CX2341X_ENC_MUTE_VIDEO +~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 217/0xD9 + +Description +^^^^^^^^^^^ + +Video muting + +Param[0] +^^^^^^^^ + +Bit usage: + +.. code-block:: none + + 0 '0'=video not muted + '1'=video muted, creates frames with the YUV color defined below + 1:7 Unused + 8:15 V chrominance information + 16:23 U chrominance information + 24:31 Y luminance information + + + +CX2341X_ENC_MUTE_AUDIO +~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 218/0xDA + +Description +^^^^^^^^^^^ + +Audio muting + +Param[0] +^^^^^^^^ + +- 0=audio not muted +- 1=audio muted (produces silent mpeg audio stream) + + + +CX2341X_ENC_SET_VERT_CROP_LINE +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 219/0xDB + +Description +^^^^^^^^^^^ + +Something to do with 'Vertical Crop Line' + +Param[0] +^^^^^^^^ + +If saa7114 and raw VBI capture and 60 Hz, then set to 10001. +Else 0. + + + +CX2341X_ENC_MISC +~~~~~~~~~~~~~~~~ + +Enum: 220/0xDC + +Description +^^^^^^^^^^^ + +Miscellaneous actions. Not known for 100% what it does. It's really a +sort of ioctl call. The first parameter is a command number, the second +the value. + +Param[0] +^^^^^^^^ + +Command number: + +.. code-block:: none + + 1=set initial SCR value when starting encoding (works). + 2=set quality mode (apparently some test setting). + 3=setup advanced VIM protection handling. + Always 1 for the cx23416 and 0 for cx23415. + 4=generate DVD compatible PTS timestamps + 5=USB flush mode + 6=something to do with the quantization matrix + 7=set navigation pack insertion for DVD: adds 0xbf (private stream 2) + packets to the MPEG. The size of these packets is 2048 bytes (including + the header of 6 bytes: 0x000001bf + length). The payload is zeroed and + it is up to the application to fill them in. These packets are apparently + inserted every four frames. + 8=enable scene change detection (seems to be a failure) + 9=set history parameters of the video input module + 10=set input field order of VIM + 11=set quantization matrix + 12=reset audio interface after channel change or input switch (has no argument). + Needed for the cx2584x, not needed for the mspx4xx, but it doesn't seem to + do any harm calling it regardless. + 13=set audio volume delay + 14=set audio delay + + +Param[1] +^^^^^^^^ + +Command value. + +Decoder firmware API description +-------------------------------- + +.. note:: this API is part of the decoder firmware, so it's cx23415 only. + + + +CX2341X_DEC_PING_FW +~~~~~~~~~~~~~~~~~~~ + +Enum: 0/0x00 + +Description +^^^^^^^^^^^ + +This API call does nothing. It may be used to check if the firmware +is responding. + + + +CX2341X_DEC_START_PLAYBACK +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 1/0x01 + +Description +^^^^^^^^^^^ + +Begin or resume playback. + +Param[0] +^^^^^^^^ + +0 based frame number in GOP to begin playback from. + +Param[1] +^^^^^^^^ + +Specifies the number of muted audio frames to play before normal +audio resumes. (This is not implemented in the firmware, leave at 0) + + + +CX2341X_DEC_STOP_PLAYBACK +~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 2/0x02 + +Description +^^^^^^^^^^^ + +Ends playback and clears all decoder buffers. If PTS is not zero, +playback stops at specified PTS. + +Param[0] +^^^^^^^^ + +Display 0=last frame, 1=black + +.. note:: + + this takes effect immediately, so if you want to wait for a PTS, + then use '0', otherwise the screen goes to black at once. + You can call this later (even if there is no playback) with a 1 value + to set the screen to black. + +Param[1] +^^^^^^^^ + +PTS low + +Param[2] +^^^^^^^^ + +PTS high + + + +CX2341X_DEC_SET_PLAYBACK_SPEED +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 3/0x03 + +Description +^^^^^^^^^^^ + +Playback stream at speed other than normal. There are two modes of +operation: + + - Smooth: host transfers entire stream and firmware drops unused + frames. + - Coarse: host drops frames based on indexing as required to achieve + desired speed. + +Param[0] +^^^^^^^^ + +.. code-block:: none + + Bitmap: + 0:7 0 normal + 1 fast only "1.5 times" + n nX fast, 1/nX slow + 30 Framedrop: + '0' during 1.5 times play, every other B frame is dropped + '1' during 1.5 times play, stream is unchanged (bitrate + must not exceed 8mbps) + 31 Speed: + '0' slow + '1' fast + +.. note:: + + n is limited to 2. Anything higher does not result in + faster playback. Instead the host should start dropping frames. + +Param[1] +^^^^^^^^ + +Direction: 0=forward, 1=reverse + +.. note:: + + to make reverse playback work you have to write full GOPs in + reverse order. + +Param[2] +^^^^^^^^ + +.. code-block:: none + + Picture mask: + 1=I frames + 3=I, P frames + 7=I, P, B frames + +Param[3] +^^^^^^^^ + +B frames per GOP (for reverse play only) + +.. note:: + + for reverse playback the Picture Mask should be set to I or I, P. + Adding B frames to the mask will result in corrupt video. This field + has to be set to the correct value in order to keep the timing correct. + +Param[4] +^^^^^^^^ + +Mute audio: 0=disable, 1=enable + +Param[5] +^^^^^^^^ + +Display 0=frame, 1=field + +Param[6] +^^^^^^^^ + +Specifies the number of muted audio frames to play before normal audio +resumes. (Not implemented in the firmware, leave at 0) + + + +CX2341X_DEC_STEP_VIDEO +~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 5/0x05 + +Description +^^^^^^^^^^^ + +Each call to this API steps the playback to the next unit defined below +in the current playback direction. + +Param[0] +^^^^^^^^ + +0=frame, 1=top field, 2=bottom field + + + +CX2341X_DEC_SET_DMA_BLOCK_SIZE +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 8/0x08 + +Description +^^^^^^^^^^^ + +Set DMA transfer block size. Counterpart to API 0xC9 + +Param[0] +^^^^^^^^ + +DMA transfer block size in bytes. A different size may be specified +when issuing the DMA transfer command. + + + +CX2341X_DEC_GET_XFER_INFO +~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 9/0x09 + +Description +^^^^^^^^^^^ + +This API call may be used to detect an end of stream condition. + +Result[0] +^^^^^^^^^ + +Stream type + +Result[1] +^^^^^^^^^ + +Address offset + +Result[2] +^^^^^^^^^ + +Maximum bytes to transfer + +Result[3] +^^^^^^^^^ + +Buffer fullness + + + +CX2341X_DEC_GET_DMA_STATUS +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 10/0x0A + +Description +^^^^^^^^^^^ + +Status of the last DMA transfer + +Result[0] +^^^^^^^^^ + +Bit 1 set means transfer complete +Bit 2 set means DMA error +Bit 3 set means linked list error + +Result[1] +^^^^^^^^^ + +DMA type: 0=MPEG, 1=OSD, 2=YUV + + + +CX2341X_DEC_SCHED_DMA_FROM_HOST +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 11/0x0B + +Description +^^^^^^^^^^^ + +Setup DMA from host operation. Counterpart to API 0xCC + +Param[0] +^^^^^^^^ + +Memory address of link list + +Param[1] +^^^^^^^^ + +Total # of bytes to transfer + +Param[2] +^^^^^^^^ + +DMA type (0=MPEG, 1=OSD, 2=YUV) + + + +CX2341X_DEC_PAUSE_PLAYBACK +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 13/0x0D + +Description +^^^^^^^^^^^ + +Freeze playback immediately. In this mode, when internal buffers are +full, no more data will be accepted and data request IRQs will be +masked. + +Param[0] +^^^^^^^^ + +Display: 0=last frame, 1=black + + + +CX2341X_DEC_HALT_FW +~~~~~~~~~~~~~~~~~~~ + +Enum: 14/0x0E + +Description +^^^^^^^^^^^ + +The firmware is halted and no further API calls are serviced until +the firmware is uploaded again. + + + +CX2341X_DEC_SET_STANDARD +~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 16/0x10 + +Description +^^^^^^^^^^^ + +Selects display standard + +Param[0] +^^^^^^^^ + +0=NTSC, 1=PAL + + + +CX2341X_DEC_GET_VERSION +~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 17/0x11 + +Description +^^^^^^^^^^^ + +Returns decoder firmware version information + +Result[0] +^^^^^^^^^ + +Version bitmask: + - Bits 0:15 build + - Bits 16:23 minor + - Bits 24:31 major + + + +CX2341X_DEC_SET_STREAM_INPUT +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 20/0x14 + +Description +^^^^^^^^^^^ + +Select decoder stream input port + +Param[0] +^^^^^^^^ + +0=memory (default), 1=streaming + + + +CX2341X_DEC_GET_TIMING_INFO +~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 21/0x15 + +Description +^^^^^^^^^^^ + +Returns timing information from start of playback + +Result[0] +^^^^^^^^^ + +Frame count by decode order + +Result[1] +^^^^^^^^^ + +Video PTS bits 0:31 by display order + +Result[2] +^^^^^^^^^ + +Video PTS bit 32 by display order + +Result[3] +^^^^^^^^^ + +SCR bits 0:31 by display order + +Result[4] +^^^^^^^^^ + +SCR bit 32 by display order + + + +CX2341X_DEC_SET_AUDIO_MODE +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 22/0x16 + +Description +^^^^^^^^^^^ + +Select audio mode + +Param[0] +^^^^^^^^ + +Dual mono mode action + 0=Stereo, 1=Left, 2=Right, 3=Mono, 4=Swap, -1=Unchanged + +Param[1] +^^^^^^^^ + +Stereo mode action: + 0=Stereo, 1=Left, 2=Right, 3=Mono, 4=Swap, -1=Unchanged + + + +CX2341X_DEC_SET_EVENT_NOTIFICATION +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 23/0x17 + +Description +^^^^^^^^^^^ + +Setup firmware to notify the host about a particular event. +Counterpart to API 0xD5 + +Param[0] +^^^^^^^^ + +Event: + - 0=Audio mode change between mono, (joint) stereo and dual channel. + - 3=Decoder started + - 4=Unknown: goes off 10-15 times per second while decoding. + - 5=Some sync event: goes off once per frame. + +Param[1] +^^^^^^^^ + +Notification 0=disabled, 1=enabled + +Param[2] +^^^^^^^^ + +Interrupt bit + +Param[3] +^^^^^^^^ + +Mailbox slot, -1 if no mailbox required. + + + +CX2341X_DEC_SET_DISPLAY_BUFFERS +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 24/0x18 + +Description +^^^^^^^^^^^ + +Number of display buffers. To decode all frames in reverse playback you +must use nine buffers. + +Param[0] +^^^^^^^^ + +0=six buffers, 1=nine buffers + + + +CX2341X_DEC_EXTRACT_VBI +~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 25/0x19 + +Description +^^^^^^^^^^^ + +Extracts VBI data + +Param[0] +^^^^^^^^ + +0=extract from extension & user data, 1=extract from private packets + +Result[0] +^^^^^^^^^ + +VBI table location + +Result[1] +^^^^^^^^^ + +VBI table size + + + +CX2341X_DEC_SET_DECODER_SOURCE +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 26/0x1A + +Description +^^^^^^^^^^^ + +Selects decoder source. Ensure that the parameters passed to this +API match the encoder settings. + +Param[0] +^^^^^^^^ + +Mode: 0=MPEG from host, 1=YUV from encoder, 2=YUV from host + +Param[1] +^^^^^^^^ + +YUV picture width + +Param[2] +^^^^^^^^ + +YUV picture height + +Param[3] +^^^^^^^^ + +Bitmap: see Param[0] of API 0xBD + + + +CX2341X_DEC_SET_PREBUFFERING +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Enum: 30/0x1E + +Description +^^^^^^^^^^^ + +Decoder prebuffering, when enabled up to 128KB are buffered for +streams <8mpbs or 640KB for streams >8mbps + +Param[0] +^^^^^^^^ + +0=off, 1=on + +PVR350 Video decoder registers 0x02002800 -> 0x02002B00 +------------------------------------------------------- + +Author: Ian Armstrong <ian@iarmst.demon.co.uk> + +Version: v0.4 + +Date: 12 March 2007 + + +This list has been worked out through trial and error. There will be mistakes +and omissions. Some registers have no obvious effect so it's hard to say what +they do, while others interact with each other, or require a certain load +sequence. Horizontal filter setup is one example, with six registers working +in unison and requiring a certain load sequence to correctly configure. The +indexed colour palette is much easier to set at just two registers, but again +it requires a certain load sequence. + +Some registers are fussy about what they are set to. Load in a bad value & the +decoder will fail. A firmware reload will often recover, but sometimes a reset +is required. For registers containing size information, setting them to 0 is +generally a bad idea. For other control registers i.e. 2878, you'll only find +out what values are bad when it hangs. + +.. code-block:: none + + -------------------------------------------------------------------------------- + 2800 + bit 0 + Decoder enable + 0 = disable + 1 = enable + -------------------------------------------------------------------------------- + 2804 + bits 0:31 + Decoder horizontal Y alias register 1 + --------------- + 2808 + bits 0:31 + Decoder horizontal Y alias register 2 + --------------- + 280C + bits 0:31 + Decoder horizontal Y alias register 3 + --------------- + 2810 + bits 0:31 + Decoder horizontal Y alias register 4 + --------------- + 2814 + bits 0:31 + Decoder horizontal Y alias register 5 + --------------- + 2818 + bits 0:31 + Decoder horizontal Y alias trigger + + These six registers control the horizontal aliasing filter for the Y plane. + The first five registers must all be loaded before accessing the trigger + (2818), as this register actually clocks the data through for the first + five. + + To correctly program set the filter, this whole procedure must be done 16 + times. The actual register contents are copied from a lookup-table in the + firmware which contains 4 different filter settings. + + -------------------------------------------------------------------------------- + 281C + bits 0:31 + Decoder horizontal UV alias register 1 + --------------- + 2820 + bits 0:31 + Decoder horizontal UV alias register 2 + --------------- + 2824 + bits 0:31 + Decoder horizontal UV alias register 3 + --------------- + 2828 + bits 0:31 + Decoder horizontal UV alias register 4 + --------------- + 282C + bits 0:31 + Decoder horizontal UV alias register 5 + --------------- + 2830 + bits 0:31 + Decoder horizontal UV alias trigger + + These six registers control the horizontal aliasing for the UV plane. + Operation is the same as the Y filter, with 2830 being the trigger + register. + + -------------------------------------------------------------------------------- + 2834 + bits 0:15 + Decoder Y source width in pixels + + bits 16:31 + Decoder Y destination width in pixels + --------------- + 2838 + bits 0:15 + Decoder UV source width in pixels + + bits 16:31 + Decoder UV destination width in pixels + + NOTE: For both registers, the resulting image must be fully visible on + screen. If the image exceeds the right edge both the source and destination + size must be adjusted to reflect the visible portion. For the source width, + you must take into account the scaling when calculating the new value. + -------------------------------------------------------------------------------- + + 283C + bits 0:31 + Decoder Y horizontal scaling + Normally = Reg 2854 >> 2 + --------------- + 2840 + bits 0:31 + Decoder ?? unknown - horizontal scaling + Usually 0x00080514 + --------------- + 2844 + bits 0:31 + Decoder UV horizontal scaling + Normally = Reg 2854 >> 2 + --------------- + 2848 + bits 0:31 + Decoder ?? unknown - horizontal scaling + Usually 0x00100514 + --------------- + 284C + bits 0:31 + Decoder ?? unknown - Y plane + Usually 0x00200020 + --------------- + 2850 + bits 0:31 + Decoder ?? unknown - UV plane + Usually 0x00200020 + --------------- + 2854 + bits 0:31 + Decoder 'master' value for horizontal scaling + --------------- + 2858 + bits 0:31 + Decoder ?? unknown + Usually 0 + --------------- + 285C + bits 0:31 + Decoder ?? unknown + Normally = Reg 2854 >> 1 + --------------- + 2860 + bits 0:31 + Decoder ?? unknown + Usually 0 + --------------- + 2864 + bits 0:31 + Decoder ?? unknown + Normally = Reg 2854 >> 1 + --------------- + 2868 + bits 0:31 + Decoder ?? unknown + Usually 0 + + Most of these registers either control horizontal scaling, or appear linked + to it in some way. Register 2854 contains the 'master' value & the other + registers can be calculated from that one. You must also remember to + correctly set the divider in Reg 2874. + + To enlarge: + Reg 2854 = (source_width * 0x00200000) / destination_width + Reg 2874 = No divide + + To reduce from full size down to half size: + Reg 2854 = (source_width/2 * 0x00200000) / destination width + Reg 2874 = Divide by 2 + + To reduce from half size down to quarter size: + Reg 2854 = (source_width/4 * 0x00200000) / destination width + Reg 2874 = Divide by 4 + + The result is always rounded up. + + -------------------------------------------------------------------------------- + 286C + bits 0:15 + Decoder horizontal Y buffer offset + + bits 15:31 + Decoder horizontal UV buffer offset + + Offset into the video image buffer. If the offset is gradually incremented, + the on screen image will move left & wrap around higher up on the right. + + -------------------------------------------------------------------------------- + 2870 + bits 0:15 + Decoder horizontal Y output offset + + bits 16:31 + Decoder horizontal UV output offset + + Offsets the actual video output. Controls output alignment of the Y & UV + planes. The higher the value, the greater the shift to the left. Use + reg 2890 to move the image right. + + -------------------------------------------------------------------------------- + 2874 + bits 0:1 + Decoder horizontal Y output size divider + 00 = No divide + 01 = Divide by 2 + 10 = Divide by 3 + + bits 4:5 + Decoder horizontal UV output size divider + 00 = No divide + 01 = Divide by 2 + 10 = Divide by 3 + + bit 8 + Decoder ?? unknown + 0 = Normal + 1 = Affects video output levels + + bit 16 + Decoder ?? unknown + 0 = Normal + 1 = Disable horizontal filter + + -------------------------------------------------------------------------------- + 2878 + bit 0 + ?? unknown + + bit 1 + osd on/off + 0 = osd off + 1 = osd on + + bit 2 + Decoder + osd video timing + 0 = NTSC + 1 = PAL + + bits 3:4 + ?? unknown + + bit 5 + Decoder + osd + Swaps upper & lower fields + + -------------------------------------------------------------------------------- + 287C + bits 0:10 + Decoder & osd ?? unknown + Moves entire screen horizontally. Starts at 0x005 with the screen + shifted heavily to the right. Incrementing in steps of 0x004 will + gradually shift the screen to the left. + + bits 11:31 + ?? unknown + + Normally contents are 0x00101111 (NTSC) or 0x1010111d (PAL) + + -------------------------------------------------------------------------------- + 2880 -------- ?? unknown + 2884 -------- ?? unknown + -------------------------------------------------------------------------------- + 2888 + bit 0 + Decoder + osd ?? unknown + 0 = Normal + 1 = Misaligned fields (Correctable through 289C & 28A4) + + bit 4 + ?? unknown + + bit 8 + ?? unknown + + Warning: Bad values will require a firmware reload to recover. + Known to be bad are 0x000,0x011,0x100,0x111 + -------------------------------------------------------------------------------- + 288C + bits 0:15 + osd ?? unknown + Appears to affect the osd position stability. The higher the value the + more unstable it becomes. Decoder output remains stable. + + bits 16:31 + osd ?? unknown + Same as bits 0:15 + + -------------------------------------------------------------------------------- + 2890 + bits 0:11 + Decoder output horizontal offset. + + Horizontal offset moves the video image right. A small left shift is + possible, but it's better to use reg 2870 for that due to its greater + range. + + NOTE: Video corruption will occur if video window is shifted off the right + edge. To avoid this read the notes for 2834 & 2838. + -------------------------------------------------------------------------------- + 2894 + bits 0:23 + Decoder output video surround colour. + + Contains the colour (in yuv) used to fill the screen when the video is + running in a window. + -------------------------------------------------------------------------------- + 2898 + bits 0:23 + Decoder video window colour + Contains the colour (in yuv) used to fill the video window when the + video is turned off. + + bit 24 + Decoder video output + 0 = Video on + 1 = Video off + + bit 28 + Decoder plane order + 0 = Y,UV + 1 = UV,Y + + bit 29 + Decoder second plane byte order + 0 = Normal (UV) + 1 = Swapped (VU) + + In normal usage, the first plane is Y & the second plane is UV. Though the + order of the planes can be swapped, only the byte order of the second plane + can be swapped. This isn't much use for the Y plane, but can be useful for + the UV plane. + + -------------------------------------------------------------------------------- + 289C + bits 0:15 + Decoder vertical field offset 1 + + bits 16:31 + Decoder vertical field offset 2 + + Controls field output vertical alignment. The higher the number, the lower + the image on screen. Known starting values are 0x011E0017 (NTSC) & + 0x01500017 (PAL) + -------------------------------------------------------------------------------- + 28A0 + bits 0:15 + Decoder & osd width in pixels + + bits 16:31 + Decoder & osd height in pixels + + All output from the decoder & osd are disabled beyond this area. Decoder + output will simply go black outside of this region. If the osd tries to + exceed this area it will become corrupt. + -------------------------------------------------------------------------------- + 28A4 + bits 0:11 + osd left shift. + + Has a range of 0x770->0x7FF. With the exception of 0, any value outside of + this range corrupts the osd. + -------------------------------------------------------------------------------- + 28A8 + bits 0:15 + osd vertical field offset 1 + + bits 16:31 + osd vertical field offset 2 + + Controls field output vertical alignment. The higher the number, the lower + the image on screen. Known starting values are 0x011E0017 (NTSC) & + 0x01500017 (PAL) + -------------------------------------------------------------------------------- + 28AC -------- ?? unknown + | + V + 28BC -------- ?? unknown + -------------------------------------------------------------------------------- + 28C0 + bit 0 + Current output field + 0 = first field + 1 = second field + + bits 16:31 + Current scanline + The scanline counts from the top line of the first field + through to the last line of the second field. + -------------------------------------------------------------------------------- + 28C4 -------- ?? unknown + | + V + 28F8 -------- ?? unknown + -------------------------------------------------------------------------------- + 28FC + bit 0 + ?? unknown + 0 = Normal + 1 = Breaks decoder & osd output + -------------------------------------------------------------------------------- + 2900 + bits 0:31 + Decoder vertical Y alias register 1 + --------------- + 2904 + bits 0:31 + Decoder vertical Y alias register 2 + --------------- + 2908 + bits 0:31 + Decoder vertical Y alias trigger + + These three registers control the vertical aliasing filter for the Y plane. + Operation is similar to the horizontal Y filter (2804). The only real + difference is that there are only two registers to set before accessing + the trigger register (2908). As for the horizontal filter, the values are + taken from a lookup table in the firmware, and the procedure must be + repeated 16 times to fully program the filter. + -------------------------------------------------------------------------------- + 290C + bits 0:31 + Decoder vertical UV alias register 1 + --------------- + 2910 + bits 0:31 + Decoder vertical UV alias register 2 + --------------- + 2914 + bits 0:31 + Decoder vertical UV alias trigger + + These three registers control the vertical aliasing filter for the UV + plane. Operation is the same as the Y filter, with 2914 being the trigger. + -------------------------------------------------------------------------------- + 2918 + bits 0:15 + Decoder Y source height in pixels + + bits 16:31 + Decoder Y destination height in pixels + --------------- + 291C + bits 0:15 + Decoder UV source height in pixels divided by 2 + + bits 16:31 + Decoder UV destination height in pixels + + NOTE: For both registers, the resulting image must be fully visible on + screen. If the image exceeds the bottom edge both the source and + destination size must be adjusted to reflect the visible portion. For the + source height, you must take into account the scaling when calculating the + new value. + -------------------------------------------------------------------------------- + 2920 + bits 0:31 + Decoder Y vertical scaling + Normally = Reg 2930 >> 2 + --------------- + 2924 + bits 0:31 + Decoder Y vertical scaling + Normally = Reg 2920 + 0x514 + --------------- + 2928 + bits 0:31 + Decoder UV vertical scaling + When enlarging = Reg 2930 >> 2 + When reducing = Reg 2930 >> 3 + --------------- + 292C + bits 0:31 + Decoder UV vertical scaling + Normally = Reg 2928 + 0x514 + --------------- + 2930 + bits 0:31 + Decoder 'master' value for vertical scaling + --------------- + 2934 + bits 0:31 + Decoder ?? unknown - Y vertical scaling + --------------- + 2938 + bits 0:31 + Decoder Y vertical scaling + Normally = Reg 2930 + --------------- + 293C + bits 0:31 + Decoder ?? unknown - Y vertical scaling + --------------- + 2940 + bits 0:31 + Decoder UV vertical scaling + When enlarging = Reg 2930 >> 1 + When reducing = Reg 2930 + --------------- + 2944 + bits 0:31 + Decoder ?? unknown - UV vertical scaling + --------------- + 2948 + bits 0:31 + Decoder UV vertical scaling + Normally = Reg 2940 + --------------- + 294C + bits 0:31 + Decoder ?? unknown - UV vertical scaling + + Most of these registers either control vertical scaling, or appear linked + to it in some way. Register 2930 contains the 'master' value & all other + registers can be calculated from that one. You must also remember to + correctly set the divider in Reg 296C + + To enlarge: + Reg 2930 = (source_height * 0x00200000) / destination_height + Reg 296C = No divide + + To reduce from full size down to half size: + Reg 2930 = (source_height/2 * 0x00200000) / destination height + Reg 296C = Divide by 2 + + To reduce from half down to quarter. + Reg 2930 = (source_height/4 * 0x00200000) / destination height + Reg 296C = Divide by 4 + + -------------------------------------------------------------------------------- + 2950 + bits 0:15 + Decoder Y line index into display buffer, first field + + bits 16:31 + Decoder Y vertical line skip, first field + -------------------------------------------------------------------------------- + 2954 + bits 0:15 + Decoder Y line index into display buffer, second field + + bits 16:31 + Decoder Y vertical line skip, second field + -------------------------------------------------------------------------------- + 2958 + bits 0:15 + Decoder UV line index into display buffer, first field + + bits 16:31 + Decoder UV vertical line skip, first field + -------------------------------------------------------------------------------- + 295C + bits 0:15 + Decoder UV line index into display buffer, second field + + bits 16:31 + Decoder UV vertical line skip, second field + -------------------------------------------------------------------------------- + 2960 + bits 0:15 + Decoder destination height minus 1 + + bits 16:31 + Decoder destination height divided by 2 + -------------------------------------------------------------------------------- + 2964 + bits 0:15 + Decoder Y vertical offset, second field + + bits 16:31 + Decoder Y vertical offset, first field + + These two registers shift the Y plane up. The higher the number, the + greater the shift. + -------------------------------------------------------------------------------- + 2968 + bits 0:15 + Decoder UV vertical offset, second field + + bits 16:31 + Decoder UV vertical offset, first field + + These two registers shift the UV plane up. The higher the number, the + greater the shift. + -------------------------------------------------------------------------------- + 296C + bits 0:1 + Decoder vertical Y output size divider + 00 = No divide + 01 = Divide by 2 + 10 = Divide by 4 + + bits 8:9 + Decoder vertical UV output size divider + 00 = No divide + 01 = Divide by 2 + 10 = Divide by 4 + -------------------------------------------------------------------------------- + 2970 + bit 0 + Decoder ?? unknown + 0 = Normal + 1 = Affect video output levels + + bit 16 + Decoder ?? unknown + 0 = Normal + 1 = Disable vertical filter + + -------------------------------------------------------------------------------- + 2974 -------- ?? unknown + | + V + 29EF -------- ?? unknown + -------------------------------------------------------------------------------- + 2A00 + bits 0:2 + osd colour mode + 000 = 8 bit indexed + 001 = 16 bit (565) + 010 = 15 bit (555) + 011 = 12 bit (444) + 100 = 32 bit (8888) + + bits 4:5 + osd display bpp + 01 = 8 bit + 10 = 16 bit + 11 = 32 bit + + bit 8 + osd global alpha + 0 = Off + 1 = On + + bit 9 + osd local alpha + 0 = Off + 1 = On + + bit 10 + osd colour key + 0 = Off + 1 = On + + bit 11 + osd ?? unknown + Must be 1 + + bit 13 + osd colour space + 0 = ARGB + 1 = AYVU + + bits 16:31 + osd ?? unknown + Must be 0x001B (some kind of buffer pointer ?) + + When the bits-per-pixel is set to 8, the colour mode is ignored and + assumed to be 8 bit indexed. For 16 & 32 bits-per-pixel the colour depth + is honoured, and when using a colour depth that requires fewer bytes than + allocated the extra bytes are used as padding. So for a 32 bpp with 8 bit + index colour, there are 3 padding bytes per pixel. It's also possible to + select 16bpp with a 32 bit colour mode. This results in the pixel width + being doubled, but the color key will not work as expected in this mode. + + Colour key is as it suggests. You designate a colour which will become + completely transparent. When using 565, 555 or 444 colour modes, the + colour key is always 16 bits wide. The colour to key on is set in Reg 2A18. + + Local alpha works differently depending on the colour mode. For 32bpp & 8 + bit indexed, local alpha is a per-pixel 256 step transparency, with 0 being + transparent and 255 being solid. For the 16bpp modes 555 & 444, the unused + bit(s) act as a simple transparency switch, with 0 being solid & 1 being + fully transparent. There is no local alpha support for 16bit 565. + + Global alpha is a 256 step transparency that applies to the entire osd, + with 0 being transparent & 255 being solid. + + It's possible to combine colour key, local alpha & global alpha. + -------------------------------------------------------------------------------- + 2A04 + bits 0:15 + osd x coord for left edge + + bits 16:31 + osd y coord for top edge + --------------- + 2A08 + bits 0:15 + osd x coord for right edge + + bits 16:31 + osd y coord for bottom edge + + For both registers, (0,0) = top left corner of the display area. These + registers do not control the osd size, only where it's positioned & how + much is visible. The visible osd area cannot exceed the right edge of the + display, otherwise the osd will become corrupt. See reg 2A10 for + setting osd width. + -------------------------------------------------------------------------------- + 2A0C + bits 0:31 + osd buffer index + + An index into the osd buffer. Slowly incrementing this moves the osd left, + wrapping around onto the right edge + -------------------------------------------------------------------------------- + 2A10 + bits 0:11 + osd buffer 32 bit word width + + Contains the width of the osd measured in 32 bit words. This means that all + colour modes are restricted to a byte width which is divisible by 4. + -------------------------------------------------------------------------------- + 2A14 + bits 0:15 + osd height in pixels + + bits 16:32 + osd line index into buffer + osd will start displaying from this line. + -------------------------------------------------------------------------------- + 2A18 + bits 0:31 + osd colour key + + Contains the colour value which will be transparent. + -------------------------------------------------------------------------------- + 2A1C + bits 0:7 + osd global alpha + + Contains the global alpha value (equiv ivtvfbctl --alpha XX) + -------------------------------------------------------------------------------- + 2A20 -------- ?? unknown + | + V + 2A2C -------- ?? unknown + -------------------------------------------------------------------------------- + 2A30 + bits 0:7 + osd colour to change in indexed palette + --------------- + 2A34 + bits 0:31 + osd colour for indexed palette + + To set the new palette, first load the index of the colour to change into + 2A30, then load the new colour into 2A34. The full palette is 256 colours, + so the index range is 0x00-0xFF + -------------------------------------------------------------------------------- + 2A38 -------- ?? unknown + 2A3C -------- ?? unknown + -------------------------------------------------------------------------------- + 2A40 + bits 0:31 + osd ?? unknown + + Affects overall brightness, wrapping around to black + -------------------------------------------------------------------------------- + 2A44 + bits 0:31 + osd ?? unknown + + Green tint + -------------------------------------------------------------------------------- + 2A48 + bits 0:31 + osd ?? unknown + + Red tint + -------------------------------------------------------------------------------- + 2A4C + bits 0:31 + osd ?? unknown + + Affects overall brightness, wrapping around to black + -------------------------------------------------------------------------------- + 2A50 + bits 0:31 + osd ?? unknown + + Colour shift + -------------------------------------------------------------------------------- + 2A54 + bits 0:31 + osd ?? unknown + + Colour shift + -------------------------------------------------------------------------------- + 2A58 -------- ?? unknown + | + V + 2AFC -------- ?? unknown + -------------------------------------------------------------------------------- + 2B00 + bit 0 + osd filter control + 0 = filter off + 1 = filter on + + bits 1:4 + osd ?? unknown + + -------------------------------------------------------------------------------- + +The cx231xx DMA engine +---------------------- + + +This page describes the structures and procedures used by the cx2341x DMA +engine. + +Introduction +~~~~~~~~~~~~ + +The cx2341x PCI interface is busmaster capable. This means it has a DMA +engine to efficiently transfer large volumes of data between the card and main +memory without requiring help from a CPU. Like most hardware, it must operate +on contiguous physical memory. This is difficult to come by in large quantities +on virtual memory machines. + +Therefore, it also supports a technique called "scatter-gather". The card can +transfer multiple buffers in one operation. Instead of allocating one large +contiguous buffer, the driver can allocate several smaller buffers. + +In practice, I've seen the average transfer to be roughly 80K, but transfers +above 128K were not uncommon, particularly at startup. The 128K figure is +important, because that is the largest block that the kernel can normally +allocate. Even still, 128K blocks are hard to come by, so the driver writer is +urged to choose a smaller block size and learn the scatter-gather technique. + +Mailbox #10 is reserved for DMA transfer information. + +Note: the hardware expects little-endian data ('intel format'). + +Flow +~~~~ + +This section describes, in general, the order of events when handling DMA +transfers. Detailed information follows this section. + +- The card raises the Encoder interrupt. +- The driver reads the transfer type, offset and size from Mailbox #10. +- The driver constructs the scatter-gather array from enough free dma buffers + to cover the size. +- The driver schedules the DMA transfer via the ScheduleDMAtoHost API call. +- The card raises the DMA Complete interrupt. +- The driver checks the DMA status register for any errors. +- The driver post-processes the newly transferred buffers. + +NOTE! It is possible that the Encoder and DMA Complete interrupts get raised +simultaneously. (End of the last, start of the next, etc.) + +Mailbox #10 +~~~~~~~~~~~ + +The Flags, Command, Return Value and Timeout fields are ignored. + +- Name: Mailbox #10 +- Results[0]: Type: 0: MPEG. +- Results[1]: Offset: The position relative to the card's memory space. +- Results[2]: Size: The exact number of bytes to transfer. + +My speculation is that since the StartCapture API has a capture type of "RAW" +available, that the type field will have other values that correspond to YUV +and PCM data. + +Scatter-Gather Array +~~~~~~~~~~~~~~~~~~~~ + +The scatter-gather array is a contiguously allocated block of memory that +tells the card the source and destination of each data-block to transfer. +Card "addresses" are derived from the offset supplied by Mailbox #10. Host +addresses are the physical memory location of the target DMA buffer. + +Each S-G array element is a struct of three 32-bit words. The first word is +the source address, the second is the destination address. Both take up the +entire 32 bits. The lowest 18 bits of the third word is the transfer byte +count. The high-bit of the third word is the "last" flag. The last-flag tells +the card to raise the DMA_DONE interrupt. From hard personal experience, if +you forget to set this bit, the card will still "work" but the stream will +most likely get corrupted. + +The transfer count must be a multiple of 256. Therefore, the driver will need +to track how much data in the target buffer is valid and deal with it +accordingly. + +Array Element: + +- 32-bit Source Address +- 32-bit Destination Address +- 14-bit reserved (high bit is the last flag) +- 18-bit byte count + +DMA Transfer Status +~~~~~~~~~~~~~~~~~~~ + +Register 0x0004 holds the DMA Transfer Status: + +- bit 0: read completed +- bit 1: write completed +- bit 2: DMA read error +- bit 3: DMA write error +- bit 4: Scatter-Gather array error diff --git a/Documentation/driver-api/media/drivers/cx88-devel.rst b/Documentation/driver-api/media/drivers/cx88-devel.rst new file mode 100644 index 000000000..cfe7c03f4 --- /dev/null +++ b/Documentation/driver-api/media/drivers/cx88-devel.rst @@ -0,0 +1,113 @@ +.. SPDX-License-Identifier: GPL-2.0 + +The cx88 driver +=============== + +Author: Gerd Hoffmann + +Documentation missing at the cx88 datasheet +------------------------------------------- + +MO_OUTPUT_FORMAT (0x310164) + +.. code-block:: none + + Previous default from DScaler: 0x1c1f0008 + Digit 8: 31-28 + 28: PREVREMOD = 1 + + Digit 7: 27-24 (0xc = 12 = b1100 ) + 27: COMBALT = 1 + 26: PAL_INV_PHASE + (DScaler apparently set this to 1, resulted in sucky picture) + + Digits 6,5: 23-16 + 25-16: COMB_RANGE = 0x1f [default] (9 bits -> max 512) + + Digit 4: 15-12 + 15: DISIFX = 0 + 14: INVCBF = 0 + 13: DISADAPT = 0 + 12: NARROWADAPT = 0 + + Digit 3: 11-8 + 11: FORCE2H + 10: FORCEREMD + 9: NCHROMAEN + 8: NREMODEN + + Digit 2: 7-4 + 7-6: YCORE + 5-4: CCORE + + Digit 1: 3-0 + 3: RANGE = 1 + 2: HACTEXT + 1: HSFMT + +0x47 is the sync byte for MPEG-2 transport stream packets. +Datasheet incorrectly states to use 47 decimal. 188 is the length. +All DVB compliant frontends output packets with this start code. + +Hauppauge WinTV cx88 IR information +----------------------------------- + +The controls for the mux are GPIO [0,1] for source, and GPIO 2 for muting. + +====== ======== ================================================= +GPIO0 GPIO1 +====== ======== ================================================= + 0 0 TV Audio + 1 0 FM radio + 0 1 Line-In + 1 1 Mono tuner bypass or CD passthru (tuner specific) +====== ======== ================================================= + +GPIO 16(I believe) is tied to the IR port (if present). + + +From the data sheet: + +- Register 24'h20004 PCI Interrupt Status + + - bit [18] IR_SMP_INT Set when 32 input samples have been collected over + - gpio[16] pin into GP_SAMPLE register. + +What's missing from the data sheet: + +- Setup 4KHz sampling rate (roughly 2x oversampled; good enough for our RC5 + compat remote) +- set register 0x35C050 to 0xa80a80 +- enable sampling +- set register 0x35C054 to 0x5 +- enable the IRQ bit 18 in the interrupt mask register (and + provide for a handler) + +GP_SAMPLE register is at 0x35C058 + +Bits are then right shifted into the GP_SAMPLE register at the specified +rate; you get an interrupt when a full DWORD is received. +You need to recover the actual RC5 bits out of the (oversampled) IR sensor +bits. (Hint: look for the 0/1and 1/0 crossings of the RC5 bi-phase data) An +actual raw RC5 code will span 2-3 DWORDS, depending on the actual alignment. + +I'm pretty sure when no IR signal is present the receiver is always in a +marking state(1); but stray light, etc can cause intermittent noise values +as well. Remember, this is a free running sample of the IR receiver state +over time, so don't assume any sample starts at any particular place. + +Additional info +~~~~~~~~~~~~~~~ + +This data sheet (google search) seems to have a lovely description of the +RC5 basics: +http://www.atmel.com/dyn/resources/prod_documents/doc2817.pdf + +This document has more data: +http://www.nenya.be/beor/electronics/rc5.htm + +This document has a how to decode a bi-phase data stream: +http://www.ee.washington.edu/circuit_archive/text/ir_decode.txt + +This document has still more info: +http://www.xs4all.nl/~sbp/knowledge/ir/rc5.htm diff --git a/Documentation/driver-api/media/drivers/dvb-usb.rst b/Documentation/driver-api/media/drivers/dvb-usb.rst new file mode 100644 index 000000000..b2d5d9e62 --- /dev/null +++ b/Documentation/driver-api/media/drivers/dvb-usb.rst @@ -0,0 +1,357 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Idea behind the dvb-usb-framework +================================= + +.. note:: + + #) This documentation is outdated. Please check at the DVB wiki + at https://linuxtv.org/wiki for more updated info. + + #) **deprecated:** Newer DVB USB drivers should use the dvb-usb-v2 framework. + +In March 2005 I got the new Twinhan USB2.0 DVB-T device. They provided specs +and a firmware. + +Quite keen I wanted to put the driver (with some quirks of course) into dibusb. +After reading some specs and doing some USB snooping, it realized, that the +dibusb-driver would be a complete mess afterwards. So I decided to do it in a +different way: With the help of a dvb-usb-framework. + +The framework provides generic functions (mostly kernel API calls), such as: + +- Transport Stream URB handling in conjunction with dvb-demux-feed-control + (bulk and isoc are supported) +- registering the device for the DVB-API +- registering an I2C-adapter if applicable +- remote-control/input-device handling +- firmware requesting and loading (currently just for the Cypress USB + controllers) +- other functions/methods which can be shared by several drivers (such as + functions for bulk-control-commands) +- TODO: a I2C-chunker. It creates device-specific chunks of register-accesses + depending on length of a register and the number of values that can be + multi-written and multi-read. + +The source code of the particular DVB USB devices does just the communication +with the device via the bus. The connection between the DVB-API-functionality +is done via callbacks, assigned in a static device-description (struct +dvb_usb_device) each device-driver has to have. + +For an example have a look in drivers/media/usb/dvb-usb/vp7045*. + +Objective is to migrate all the usb-devices (dibusb, cinergyT2, maybe the +ttusb; flexcop-usb already benefits from the generic flexcop-device) to use +the dvb-usb-lib. + +TODO: dynamic enabling and disabling of the pid-filter in regard to number of +feeds requested. + +Supported devices +----------------- + +See the LinuxTV DVB Wiki at https://linuxtv.org for a complete list of +cards/drivers/firmwares: +https://linuxtv.org/wiki/index.php/DVB_USB + +0. History & News: + + 2005-06-30 + + - added support for WideView WT-220U (Thanks to Steve Chang) + + 2005-05-30 + + - added basic isochronous support to the dvb-usb-framework + - added support for Conexant Hybrid reference design and Nebula + DigiTV USB + + 2005-04-17 + + - all dibusb devices ported to make use of the dvb-usb-framework + + 2005-04-02 + + - re-enabled and improved remote control code. + + 2005-03-31 + + - ported the Yakumo/Hama/Typhoon DVB-T USB2.0 device to dvb-usb. + + 2005-03-30 + + - first commit of the dvb-usb-module based on the dibusb-source. + First device is a new driver for the + TwinhanDTV Alpha / MagicBox II USB2.0-only DVB-T device. + - (change from dvb-dibusb to dvb-usb) + + 2005-03-28 + + - added support for the AVerMedia AverTV DVB-T USB2.0 device + (Thanks to Glen Harris and Jiun-Kuei Jung, AVerMedia) + + 2005-03-14 + + - added support for the Typhoon/Yakumo/HAMA DVB-T mobile USB2.0 + + 2005-02-11 + + - added support for the KWorld/ADSTech Instant DVB-T USB2.0. + Thanks a lot to Joachim von Caron + + 2005-02-02 + - added support for the Hauppauge Win-TV Nova-T USB2 + + 2005-01-31 + - distorted streaming is gone for USB1.1 devices + + 2005-01-13 + + - moved the mirrored pid_filter_table back to dvb-dibusb + first almost working version for HanfTek UMT-010 + found out, that Yakumo/HAMA/Typhoon are predecessors of the HanfTek UMT-010 + + 2005-01-10 + + - refactoring completed, now everything is very delightful + + - tuner quirks for some weird devices (Artec T1 AN2235 device has sometimes a + Panasonic Tuner assembled). Tunerprobing implemented. + Thanks a lot to Gunnar Wittich. + + 2004-12-29 + + - after several days of struggling around bug of no returning URBs fixed. + + 2004-12-26 + + - refactored the dibusb-driver, split into separate files + - i2c-probing enabled + + 2004-12-06 + + - possibility for demod i2c-address probing + - new usb IDs (Compro, Artec) + + 2004-11-23 + + - merged changes from DiB3000MC_ver2.1 + - revised the debugging + - possibility to deliver the complete TS for USB2.0 + + 2004-11-21 + + - first working version of the dib3000mc/p frontend driver. + + 2004-11-12 + + - added additional remote control keys. Thanks to Uwe Hanke. + + 2004-11-07 + + - added remote control support. Thanks to David Matthews. + + 2004-11-05 + + - added support for a new devices (Grandtec/Avermedia/Artec) + - merged my changes (for dib3000mb/dibusb) to the FE_REFACTORING, because it became HEAD + - moved transfer control (pid filter, fifo control) from usb driver to frontend, it seems + better settled there (added xfer_ops-struct) + - created a common files for frontends (mc/p/mb) + + 2004-09-28 + + - added support for a new device (Unknown, vendor ID is Hyper-Paltek) + + 2004-09-20 + + - added support for a new device (Compro DVB-U2000), thanks + to Amaury Demol for reporting + - changed usb TS transfer method (several urbs, stopping transfer + before setting a new pid) + + 2004-09-13 + + - added support for a new device (Artec T1 USB TVBOX), thanks + to Christian Motschke for reporting + + 2004-09-05 + + - released the dibusb device and dib3000mb-frontend driver + (old news for vp7041.c) + + 2004-07-15 + + - found out, by accident, that the device has a TUA6010XS for PLL + + 2004-07-12 + + - figured out, that the driver should also work with the + CTS Portable (Chinese Television System) + + 2004-07-08 + + - firmware-extraction-2.422-problem solved, driver is now working + properly with firmware extracted from 2.422 + - #if for 2.6.4 (dvb), compile issue + - changed firmware handling, see vp7041.txt sec 1.1 + + 2004-07-02 + + - some tuner modifications, v0.1, cleanups, first public + + 2004-06-28 + + - now using the dvb_dmx_swfilter_packets, everything runs fine now + + 2004-06-27 + + - able to watch and switching channels (pre-alpha) + - no section filtering yet + + 2004-06-06 + + - first TS received, but kernel oops :/ + + 2004-05-14 + + - firmware loader is working + + 2004-05-11 + + - start writing the driver + +How to use? +----------- + +Firmware +~~~~~~~~ + +Most of the USB drivers need to download a firmware to the device before start +working. + +Have a look at the Wikipage for the DVB-USB-drivers to find out, which firmware +you need for your device: + +https://linuxtv.org/wiki/index.php/DVB_USB + +Compiling +~~~~~~~~~ + +Since the driver is in the linux kernel, activating the driver in +your favorite config-environment should sufficient. I recommend +to compile the driver as module. Hotplug does the rest. + +If you use dvb-kernel enter the build-2.6 directory run 'make' and 'insmod.sh +load' afterwards. + +Loading the drivers +~~~~~~~~~~~~~~~~~~~ + +Hotplug is able to load the driver, when it is needed (because you plugged +in the device). + +If you want to enable debug output, you have to load the driver manually and +from within the dvb-kernel cvs repository. + +first have a look, which debug level are available: + +.. code-block:: none + + # modinfo dvb-usb + # modinfo dvb-usb-vp7045 + + etc. + +.. code-block:: none + + modprobe dvb-usb debug=<level> + modprobe dvb-usb-vp7045 debug=<level> + etc. + +should do the trick. + +When the driver is loaded successfully, the firmware file was in +the right place and the device is connected, the "Power"-LED should be +turned on. + +At this point you should be able to start a dvb-capable application. I'm use +(t|s)zap, mplayer and dvbscan to test the basics. VDR-xine provides the +long-term test scenario. + +Known problems and bugs +----------------------- + +- Don't remove the USB device while running an DVB application, your system + will go crazy or die most likely. + +Adding support for devices +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +TODO + +USB1.1 Bandwidth limitation +~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +A lot of the currently supported devices are USB1.1 and thus they have a +maximum bandwidth of about 5-6 MBit/s when connected to a USB2.0 hub. +This is not enough for receiving the complete transport stream of a +DVB-T channel (which is about 16 MBit/s). Normally this is not a +problem, if you only want to watch TV (this does not apply for HDTV), +but watching a channel while recording another channel on the same +frequency simply does not work very well. This applies to all USB1.1 +DVB-T devices, not just the dvb-usb-devices) + +The bug, where the TS is distorted by a heavy usage of the device is gone +definitely. All dvb-usb-devices I was using (Twinhan, Kworld, DiBcom) are +working like charm now with VDR. Sometimes I even was able to record a channel +and watch another one. + +Comments +~~~~~~~~ + +Patches, comments and suggestions are very very welcome. + +3. Acknowledgements +------------------- + + Amaury Demol (Amaury.Demol@parrot.com) and Francois Kanounnikoff from DiBcom for + providing specs, code and help, on which the dvb-dibusb, dib3000mb and + dib3000mc are based. + + David Matthews for identifying a new device type (Artec T1 with AN2235) + and for extending dibusb with remote control event handling. Thank you. + + Alex Woods for frequently answering question about usb and dvb + stuff, a big thank you. + + Bernd Wagner for helping with huge bug reports and discussions. + + Gunnar Wittich and Joachim von Caron for their trust for providing + root-shells on their machines to implement support for new devices. + + Allan Third and Michael Hutchinson for their help to write the Nebula + digitv-driver. + + Glen Harris for bringing up, that there is a new dibusb-device and Jiun-Kuei + Jung from AVerMedia who kindly provided a special firmware to get the device + up and running in Linux. + + Jennifer Chen, Jeff and Jack from Twinhan for kindly supporting by + writing the vp7045-driver. + + Steve Chang from WideView for providing information for new devices and + firmware files. + + Michael Paxton for submitting remote control keymaps. + + Some guys on the linux-dvb mailing list for encouraging me. + + Peter Schildmann >peter.schildmann-nospam-at-web.de< for his + user-level firmware loader, which saves a lot of time + (when writing the vp7041 driver) + + Ulf Hermenau for helping me out with traditional chinese. + + André Smoktun and Christian Frömmel for supporting me with + hardware and listening to my problems very patiently. diff --git a/Documentation/driver-api/media/drivers/fimc-devel.rst b/Documentation/driver-api/media/drivers/fimc-devel.rst new file mode 100644 index 000000000..4c6b7c8be --- /dev/null +++ b/Documentation/driver-api/media/drivers/fimc-devel.rst @@ -0,0 +1,33 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. include:: <isonum.txt> + +The Samsung S5P/EXYNOS4 FIMC driver +=================================== + +Copyright |copy| 2012 - 2013 Samsung Electronics Co., Ltd. + +Files partitioning +------------------ + +- media device driver + + drivers/media/platform/samsung/exynos4-is/media-dev.[ch] + +- camera capture video device driver + + drivers/media/platform/samsung/exynos4-is/fimc-capture.c + +- MIPI-CSI2 receiver subdev + + drivers/media/platform/samsung/exynos4-is/mipi-csis.[ch] + +- video post-processor (mem-to-mem) + + drivers/media/platform/samsung/exynos4-is/fimc-core.c + +- common files + + drivers/media/platform/samsung/exynos4-is/fimc-core.h + drivers/media/platform/samsung/exynos4-is/fimc-reg.h + drivers/media/platform/samsung/exynos4-is/regs-fimc.h diff --git a/Documentation/driver-api/media/drivers/frontends.rst b/Documentation/driver-api/media/drivers/frontends.rst new file mode 100644 index 000000000..7b8336ece --- /dev/null +++ b/Documentation/driver-api/media/drivers/frontends.rst @@ -0,0 +1,32 @@ +.. SPDX-License-Identifier: GPL-2.0 + +**************** +Frontend drivers +**************** + +Frontend attach headers +*********************** + +.. Keep it on alphabetic order + +.. kernel-doc:: drivers/media/dvb-frontends/a8293.h +.. kernel-doc:: drivers/media/dvb-frontends/af9013.h +.. kernel-doc:: drivers/media/dvb-frontends/ascot2e.h +.. kernel-doc:: drivers/media/dvb-frontends/cxd2820r.h +.. kernel-doc:: drivers/media/dvb-frontends/drxk.h +.. kernel-doc:: drivers/media/dvb-frontends/dvb-pll.h +.. kernel-doc:: drivers/media/dvb-frontends/helene.h +.. kernel-doc:: drivers/media/dvb-frontends/horus3a.h +.. kernel-doc:: drivers/media/dvb-frontends/ix2505v.h +.. kernel-doc:: drivers/media/dvb-frontends/m88ds3103.h +.. kernel-doc:: drivers/media/dvb-frontends/mb86a20s.h +.. kernel-doc:: drivers/media/dvb-frontends/mn88472.h +.. kernel-doc:: drivers/media/dvb-frontends/rtl2830.h +.. kernel-doc:: drivers/media/dvb-frontends/rtl2832.h +.. kernel-doc:: drivers/media/dvb-frontends/rtl2832_sdr.h +.. kernel-doc:: drivers/media/dvb-frontends/stb6000.h +.. kernel-doc:: drivers/media/dvb-frontends/tda10071.h +.. kernel-doc:: drivers/media/dvb-frontends/tda826x.h +.. kernel-doc:: drivers/media/dvb-frontends/zd1301_demod.h +.. kernel-doc:: drivers/media/dvb-frontends/zl10036.h + diff --git a/Documentation/driver-api/media/drivers/index.rst b/Documentation/driver-api/media/drivers/index.rst new file mode 100644 index 000000000..7f6f3dcd5 --- /dev/null +++ b/Documentation/driver-api/media/drivers/index.rst @@ -0,0 +1,41 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. include:: <isonum.txt> + +=================================== +Media driver-specific documentation +=================================== + +Video4Linux (V4L) drivers +========================= + +.. toctree:: + :maxdepth: 5 + + bttv-devel + cx2341x-devel + cx88-devel + fimc-devel + pvrusb2 + pxa_camera + radiotrack + rkisp1 + saa7134-devel + sh_mobile_ceu_camera + tuners + vimc-devel + zoran + ccs/ccs + ipu6 + + +Digital TV drivers +================== + +.. toctree:: + :maxdepth: 5 + + dvb-usb + frontends + vidtv + contributors diff --git a/Documentation/driver-api/media/drivers/ipu6.rst b/Documentation/driver-api/media/drivers/ipu6.rst new file mode 100644 index 000000000..88f6498e7 --- /dev/null +++ b/Documentation/driver-api/media/drivers/ipu6.rst @@ -0,0 +1,190 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================== +Intel IPU6 Driver +================== + +Author: Bingbu Cao <bingbu.cao@intel.com> + +Overview +========= + +Intel IPU6 is the sixth generation of Intel Image Processing Unit used in some +Intel Chipsets such as Tiger Lake, Jasper Lake, Alder Lake, Raptor Lake and +Meteor Lake. IPU6 consists of two major systems: Input System (ISYS) and +Processing System (PSYS). IPU6 are visible on the PCI bus as a single device, it +can be found by ``lspci``: + +``0000:00:05.0 Multimedia controller: Intel Corporation Device xxxx (rev xx)`` + +IPU6 has a 16 MB BAR in PCI configuration Space for MMIO registers which is +visible for driver. + +Buttress +========= + +The IPU6 is connecting to the system fabric with Buttress which is enabling host +driver to control the IPU6, it also allows IPU6 access the system memory to +store and load frame pixel streams and any other metadata. + +Buttress mainly manages several system functionalities: power management, +interrupt handling, firmware authentication and global timer sync. + +ISYS and PSYS Power flow +------------------------ + +IPU6 driver initialize the ISYS and PSYS power up or down request by setting the +Buttress frequency control register for ISYS and PSYS +(``IPU6_BUTTRESS_REG_IS_FREQ_CTL`` and ``IPU6_BUTTRESS_REG_PS_FREQ_CTL``) in +function: + +.. c:function:: int ipu6_buttress_power(...) + +Buttress forwards the request to Punit, after Punit execute the power up flow, +Buttress indicates driver that ISYS or PSYS is powered up by updating the power +status registers. + +.. Note:: ISYS power up needs take place prior to PSYS power up, ISYS power down + needs take place after PSYS power down due to hardware limitation. + +Interrupt +--------- + +IPU6 interrupt can be generated as MSI or INTA, interrupt will be triggered when +ISYS, PSYS, Buttress event or error happen, driver can get the interrupt cause +by reading the interrupt status register ``BUTTRESS_REG_ISR_STATUS``, driver +clears the irq status and then calls specific ISYS or PSYS irq handler. + +.. c:function:: irqreturn_t ipu6_buttress_isr(int irq, ...) + +Security and firmware authentication +------------------------------------- + +To address the IPU6 firmware security concerns, the IPU6 firmware needs to +undergo an authentication process before it is allowed to executed on the IPU6 +internal processors. The IPU6 driver will work with Converged Security Engine +(CSE) to complete authentication process. The CSE is responsible of +authenticating the IPU6 firmware. The authenticated firmware binary is copied +into an isolated memory region. Firmware authentication process is implemented +by CSE following an IPC handshake with the IPU6 driver. There are some Buttress +registers used by the CSE and the IPU6 driver to communicate with each other via +IPC. + +.. c:function:: int ipu6_buttress_authenticate(...) + +Global timer sync +----------------- + +The IPU6 driver initiates a Hammock Harbor synchronization flow each time it +starts camera operation. The IPU6 will synchronizes an internal counter in the +Buttress with a copy of the SoC time, this counter maintains the up-to-date time +until camera operation is stopped. The IPU6 driver can use this time counter to +calibrate the timestamp based on the timestamp in response event from firmware. + +.. c:function:: int ipu6_buttress_start_tsc_sync(...) + +DMA and MMU +============ + +The IPU6 has its own scalar processor where the firmware run at and an internal +32-bit virtual address space. The IPU6 has MMU address translation hardware to +allow that scalar processors to access the internal memory and external system +memory through IPU6 virtual address. The address translation is based on two +levels of page lookup tables stored in system memory which are maintained by the +IPU6 driver. The IPU6 driver sets the level-1 page table base address to MMU +register and allows MMU to perform page table lookups. + +The IPU6 driver exports its own DMA operations. The IPU6 driver will update the +page table entries for each DMA operation and invalidate the MMU TLB after each +unmap and free. + +Firmware file format +==================== + +The IPU6 firmware is in Code Partition Directory (CPD) file format. The CPD +firmware contains a CPD header, several CPD entries and components. The CPD +component includes 3 entries - manifest, metadata and module data. Manifest and +metadata are defined by CSE and used by CSE for authentication. Module data is +specific to IPU6 which holds the binary data of firmware called package +directory. The IPU6 driver (``ipu6-cpd.c`` in particular) parses and validates +the CPD firmware file and gets the package directory binary data of the IPU6 +firmware, copies it to specific DMA buffer and sets its base address to Buttress +``FW_SOURCE_BASE`` register. Finally the CSE will do authentication for this +firmware binary. + + +Syscom interface +================ + +The IPU6 driver communicates with firmware via the Syscom ABI. Syscom is an +inter-processor communication mechanism between the IPU scalar processors and +the CPU. There are a number of resources shared between firmware and software. +A system memory region where the message queues reside, firmware can access the +memory region via the IPU MMU. The Syscom queues are FIFO fixed depth queues +with a configurable number of tokens (messages). There are also common IPU6 MMIO +registers where the queue read and write indices reside. Software and firmware +function as producer and consumer of tokens in the queues and update the write +and read indices separately when sending or receiving each message. + +The IPU6 driver must prepare and configure the number of input and output +queues, configure the count of tokens per queue and the size of per token before +initiating and starting the communication with firmware. Firmware and software +must use same configurations. The IPU6 Buttress has a number of firmware boot +parameter registers which can be used to store the address of configuration and +initialise the Syscom state, then driver can request firmware to start and run via +setting the scalar processor control status register. + +Input System +============ + +IPU6 input system consists of MIPI D-PHY and several CSI-2 receivers. It can +capture image pixel data from camera sensors or other MIPI CSI-2 output devices. + +D-PHYs and CSI-2 ports lane mapping +----------------------------------- + +The IPU6 integrates different D-PHY IPs on different SoCs, on Tiger Lake and +Alder Lake, IPU6 integrates MCD10 D-PHY, IPU6SE on Jasper Lake integrates JSL +D-PHY and IPU6EP on Meteor Lake integrates a Synopsys DWC D-PHY. There is an +adaptional layer between D-PHY and CSI-2 receiver controller which includes port +configuration, PHY wrapper or private test interfaces for D-PHY. There are 3 +D-PHY drivers ``ipu6-isys-mcd-phy.c``, ``ipu6-isys-jsl-phy.c`` and +``ipu6-isys-dwc-phy.c`` program the above 3 D-PHYs in IPU6. + +Different IPU6 versions have different D-PHY lanes mappings, On Tiger Lake, +there are 12 data lanes and 8 clock lanes, IPU6 support maximum 8 CSI-2 ports, +see the PPI mmapping in ``ipu6-isys-mcd-phy.c`` for more information. On Jasper +Lake and Alder Lake, D-PHY has 8 data lanes and 4 clock lanes, the IPU6 supports +maximum 4 CSI-2 ports. For Meteor Lake, D-PHY has 12 data lanes and 6 clock +lanes so IPU6 support maximum 6 CSI-2 ports. + +.. Note:: Each pair of CSI-2 two ports is a single unit that can share the data + lanes. For example, for CSI-2 port 0 and 1, CSI-2 port 0 support + maximum 4 data lanes, CSI-2 port 1 support maximum 2 data lanes, CSI-2 + port 0 with 2 data lanes can work together with CSI-2 port 1 with 2 + data lanes. If trying to use CSI-2 port 0 with 4 lanes, CSI-2 port 1 + will not be available as the 4 data lanes are shared by CSI-2 port 0 + and 1. The same applies to CSI ports 2/3, 4/5 and 7/8. + +ISYS firmware ABIs +------------------ + +The IPU6 firmware implements a series of ABIs for software access. In general, +software firstly prepares the stream configuration ``struct +ipu6_fw_isys_stream_cfg_data_abi`` and sends the configuration to firmware via +sending ``STREAM_OPEN`` command. Stream configuration includes input pins and +output pins, input pin ``struct ipu6_fw_isys_input_pin_info_abi`` defines the +resolution and data type of input source, output pin ``struct +ipu6_fw_isys_output_pin_info_abi`` defines the output resolution, stride and +frame format, etc. + +Once the driver gets the interrupt from firmware that indicates stream open +successfully, the driver will send the ``STREAM_START`` and ``STREAM_CAPTURE`` +command to request firmware to start capturing image frames. ``STREAM_CAPTURE`` +command queues the buffers to firmware with ``struct +ipu6_fw_isys_frame_buff_set``, software then waits for the interrupt and +response from firmware, ``PIN_DATA_READY`` means a buffer is ready on a specific +output pin and then software can return the buffer to user. + +.. Note:: See :ref:`Examples<ipu6_isys_capture_examples>` about how to do + capture by IPU6 ISYS driver. diff --git a/Documentation/driver-api/media/drivers/pvrusb2.rst b/Documentation/driver-api/media/drivers/pvrusb2.rst new file mode 100644 index 000000000..cbd9359c2 --- /dev/null +++ b/Documentation/driver-api/media/drivers/pvrusb2.rst @@ -0,0 +1,202 @@ +.. SPDX-License-Identifier: GPL-2.0 + +The pvrusb2 driver +================== + +Author: Mike Isely <isely@pobox.com> + +Background +---------- + +This driver is intended for the "Hauppauge WinTV PVR USB 2.0", which +is a USB 2.0 hosted TV Tuner. This driver is a work in progress. +Its history started with the reverse-engineering effort by Björn +Danielsson <pvrusb2@dax.nu> whose web page can be found here: +http://pvrusb2.dax.nu/ + +From there Aurelien Alleaume <slts@free.fr> began an effort to +create a video4linux compatible driver. I began with Aurelien's +last known snapshot and evolved the driver to the state it is in +here. + +More information on this driver can be found at: +https://www.isely.net/pvrusb2.html + + +This driver has a strong separation of layers. They are very +roughly: + +1. Low level wire-protocol implementation with the device. + +2. I2C adaptor implementation and corresponding I2C client drivers + implemented elsewhere in V4L. + +3. High level hardware driver implementation which coordinates all + activities that ensure correct operation of the device. + +4. A "context" layer which manages instancing of driver, setup, + tear-down, arbitration, and interaction with high level + interfaces appropriately as devices are hotplugged in the + system. + +5. High level interfaces which glue the driver to various published + Linux APIs (V4L, sysfs, maybe DVB in the future). + +The most important shearing layer is between the top 2 layers. A +lot of work went into the driver to ensure that any kind of +conceivable API can be laid on top of the core driver. (Yes, the +driver internally leverages V4L to do its work but that really has +nothing to do with the API published by the driver to the outside +world.) The architecture allows for different APIs to +simultaneously access the driver. I have a strong sense of fairness +about APIs and also feel that it is a good design principle to keep +implementation and interface isolated from each other. Thus while +right now the V4L high level interface is the most complete, the +sysfs high level interface will work equally well for similar +functions, and there's no reason I see right now why it shouldn't be +possible to produce a DVB high level interface that can sit right +alongside V4L. + +Building +-------- + +To build these modules essentially amounts to just running "Make", +but you need the kernel source tree nearby and you will likely also +want to set a few controlling environment variables first in order +to link things up with that source tree. Please see the Makefile +here for comments that explain how to do that. + +Source file list / functional overview +-------------------------------------- + +(Note: The term "module" used below generally refers to loosely +defined functional units within the pvrusb2 driver and bears no +relation to the Linux kernel's concept of a loadable module.) + +pvrusb2-audio.[ch] - This is glue logic that resides between this + driver and the msp3400.ko I2C client driver (which is found + elsewhere in V4L). + +pvrusb2-context.[ch] - This module implements the context for an + instance of the driver. Everything else eventually ties back to + or is otherwise instanced within the data structures implemented + here. Hotplugging is ultimately coordinated here. All high level + interfaces tie into the driver through this module. This module + helps arbitrate each interface's access to the actual driver core, + and is designed to allow concurrent access through multiple + instances of multiple interfaces (thus you can for example change + the tuner's frequency through sysfs while simultaneously streaming + video through V4L out to an instance of mplayer). + +pvrusb2-debug.h - This header defines a printk() wrapper and a mask + of debugging bit definitions for the various kinds of debug + messages that can be enabled within the driver. + +pvrusb2-debugifc.[ch] - This module implements a crude command line + oriented debug interface into the driver. Aside from being part + of the process for implementing manual firmware extraction (see + the pvrusb2 web site mentioned earlier), probably I'm the only one + who has ever used this. It is mainly a debugging aid. + +pvrusb2-eeprom.[ch] - This is glue logic that resides between this + driver the tveeprom.ko module, which is itself implemented + elsewhere in V4L. + +pvrusb2-encoder.[ch] - This module implements all protocol needed to + interact with the Conexant mpeg2 encoder chip within the pvrusb2 + device. It is a crude echo of corresponding logic in ivtv, + however the design goals (strict isolation) and physical layer + (proxy through USB instead of PCI) are enough different that this + implementation had to be completely different. + +pvrusb2-hdw-internal.h - This header defines the core data structure + in the driver used to track ALL internal state related to control + of the hardware. Nobody outside of the core hardware-handling + modules should have any business using this header. All external + access to the driver should be through one of the high level + interfaces (e.g. V4L, sysfs, etc), and in fact even those high + level interfaces are restricted to the API defined in + pvrusb2-hdw.h and NOT this header. + +pvrusb2-hdw.h - This header defines the full internal API for + controlling the hardware. High level interfaces (e.g. V4L, sysfs) + will work through here. + +pvrusb2-hdw.c - This module implements all the various bits of logic + that handle overall control of a specific pvrusb2 device. + (Policy, instantiation, and arbitration of pvrusb2 devices fall + within the jurisdiction of pvrusb-context not here). + +pvrusb2-i2c-chips-\*.c - These modules implement the glue logic to + tie together and configure various I2C modules as they attach to + the I2C bus. There are two versions of this file. The "v4l2" + version is intended to be used in-tree alongside V4L, where we + implement just the logic that makes sense for a pure V4L + environment. The "all" version is intended for use outside of + V4L, where we might encounter other possibly "challenging" modules + from ivtv or older kernel snapshots (or even the support modules + in the standalone snapshot). + +pvrusb2-i2c-cmd-v4l1.[ch] - This module implements generic V4L1 + compatible commands to the I2C modules. It is here where state + changes inside the pvrusb2 driver are translated into V4L1 + commands that are in turn send to the various I2C modules. + +pvrusb2-i2c-cmd-v4l2.[ch] - This module implements generic V4L2 + compatible commands to the I2C modules. It is here where state + changes inside the pvrusb2 driver are translated into V4L2 + commands that are in turn send to the various I2C modules. + +pvrusb2-i2c-core.[ch] - This module provides an implementation of a + kernel-friendly I2C adaptor driver, through which other external + I2C client drivers (e.g. msp3400, tuner, lirc) may connect and + operate corresponding chips within the pvrusb2 device. It is + through here that other V4L modules can reach into this driver to + operate specific pieces (and those modules are in turn driven by + glue logic which is coordinated by pvrusb2-hdw, doled out by + pvrusb2-context, and then ultimately made available to users + through one of the high level interfaces). + +pvrusb2-io.[ch] - This module implements a very low level ring of + transfer buffers, required in order to stream data from the + device. This module is *very* low level. It only operates the + buffers and makes no attempt to define any policy or mechanism for + how such buffers might be used. + +pvrusb2-ioread.[ch] - This module layers on top of pvrusb2-io.[ch] + to provide a streaming API usable by a read() system call style of + I/O. Right now this is the only layer on top of pvrusb2-io.[ch], + however the underlying architecture here was intended to allow for + other styles of I/O to be implemented with additional modules, like + mmap()'ed buffers or something even more exotic. + +pvrusb2-main.c - This is the top level of the driver. Module level + and USB core entry points are here. This is our "main". + +pvrusb2-sysfs.[ch] - This is the high level interface which ties the + pvrusb2 driver into sysfs. Through this interface you can do + everything with the driver except actually stream data. + +pvrusb2-tuner.[ch] - This is glue logic that resides between this + driver and the tuner.ko I2C client driver (which is found + elsewhere in V4L). + +pvrusb2-util.h - This header defines some common macros used + throughout the driver. These macros are not really specific to + the driver, but they had to go somewhere. + +pvrusb2-v4l2.[ch] - This is the high level interface which ties the + pvrusb2 driver into video4linux. It is through here that V4L + applications can open and operate the driver in the usual V4L + ways. Note that **ALL** V4L functionality is published only + through here and nowhere else. + +pvrusb2-video-\*.[ch] - This is glue logic that resides between this + driver and the saa711x.ko I2C client driver (which is found + elsewhere in V4L). Note that saa711x.ko used to be known as + saa7115.ko in ivtv. There are two versions of this; one is + selected depending on the particular saa711[5x].ko that is found. + +pvrusb2.h - This header contains compile time tunable parameters + (and at the moment the driver has very little that needs to be + tuned). diff --git a/Documentation/driver-api/media/drivers/pxa_camera.rst b/Documentation/driver-api/media/drivers/pxa_camera.rst new file mode 100644 index 000000000..46919919b --- /dev/null +++ b/Documentation/driver-api/media/drivers/pxa_camera.rst @@ -0,0 +1,194 @@ +.. SPDX-License-Identifier: GPL-2.0 + +PXA-Camera Host Driver +====================== + +Author: Robert Jarzmik <robert.jarzmik@free.fr> + +Constraints +----------- + +a) Image size for YUV422P format + All YUV422P images are enforced to have width x height % 16 = 0. + This is due to DMA constraints, which transfers only planes of 8 byte + multiples. + + +Global video workflow +--------------------- + +a) QCI stopped + Initially, the QCI interface is stopped. + When a buffer is queued, start_streaming is called and the QCI starts. + +b) QCI started + More buffers can be queued while the QCI is started without halting the + capture. The new buffers are "appended" at the tail of the DMA chain, and + smoothly captured one frame after the other. + + Once a buffer is filled in the QCI interface, it is marked as "DONE" and + removed from the active buffers list. It can be then requeud or dequeued by + userland application. + + Once the last buffer is filled in, the QCI interface stops. + +c) Capture global finite state machine schema + +.. code-block:: none + + +----+ +---+ +----+ + | DQ | | Q | | DQ | + | v | v | v + +-----------+ +------------------------+ + | STOP | | Wait for capture start | + +-----------+ Q +------------------------+ + +-> | QCI: stop | ------------------> | QCI: run | <------------+ + | | DMA: stop | | DMA: stop | | + | +-----------+ +-----> +------------------------+ | + | / | | + | / +---+ +----+ | | + |capture list empty / | Q | | DQ | | QCI Irq EOF | + | / | v | v v | + | +--------------------+ +----------------------+ | + | | DMA hotlink missed | | Capture running | | + | +--------------------+ +----------------------+ | + | | QCI: run | +-----> | QCI: run | <-+ | + | | DMA: stop | / | DMA: run | | | + | +--------------------+ / +----------------------+ | Other | + | ^ /DMA still | | channels | + | | capture list / running | DMA Irq End | not | + | | not empty / | | finished | + | | / v | yet | + | +----------------------+ +----------------------+ | | + | | Videobuf released | | Channel completed | | | + | +----------------------+ +----------------------+ | | + +-- | QCI: run | | QCI: run | --+ | + | DMA: run | | DMA: run | | + +----------------------+ +----------------------+ | + ^ / | | + | no overrun / | overrun | + | / v | + +--------------------+ / +----------------------+ | + | Frame completed | / | Frame overran | | + +--------------------+ <-----+ +----------------------+ restart frame | + | QCI: run | | QCI: stop | --------------+ + | DMA: run | | DMA: stop | + +--------------------+ +----------------------+ + + Legend: - each box is a FSM state + - each arrow is the condition to transition to another state + - an arrow with a comment is a mandatory transition (no condition) + - arrow "Q" means : a buffer was enqueued + - arrow "DQ" means : a buffer was dequeued + - "QCI: stop" means the QCI interface is not enabled + - "DMA: stop" means all 3 DMA channels are stopped + - "DMA: run" means at least 1 DMA channel is still running + +DMA usage +--------- + +a) DMA flow + - first buffer queued for capture + Once a first buffer is queued for capture, the QCI is started, but data + transfer is not started. On "End Of Frame" interrupt, the irq handler + starts the DMA chain. + - capture of one videobuffer + The DMA chain starts transferring data into videobuffer RAM pages. + When all pages are transferred, the DMA irq is raised on "ENDINTR" status + - finishing one videobuffer + The DMA irq handler marks the videobuffer as "done", and removes it from + the active running queue + Meanwhile, the next videobuffer (if there is one), is transferred by DMA + - finishing the last videobuffer + On the DMA irq of the last videobuffer, the QCI is stopped. + +b) DMA prepared buffer will have this structure + +.. code-block:: none + + +------------+-----+---------------+-----------------+ + | desc-sg[0] | ... | desc-sg[last] | finisher/linker | + +------------+-----+---------------+-----------------+ + +This structure is pointed by dma->sg_cpu. +The descriptors are used as follows: + +- desc-sg[i]: i-th descriptor, transferring the i-th sg + element to the video buffer scatter gather +- finisher: has ddadr=DADDR_STOP, dcmd=ENDIRQEN +- linker: has ddadr= desc-sg[0] of next video buffer, dcmd=0 + +For the next schema, let's assume d0=desc-sg[0] .. dN=desc-sg[N], +"f" stands for finisher and "l" for linker. +A typical running chain is : + +.. code-block:: none + + Videobuffer 1 Videobuffer 2 + +---------+----+---+ +----+----+----+---+ + | d0 | .. | dN | l | | d0 | .. | dN | f | + +---------+----+-|-+ ^----+----+----+---+ + | | + +----+ + +After the chaining is finished, the chain looks like : + +.. code-block:: none + + Videobuffer 1 Videobuffer 2 Videobuffer 3 + +---------+----+---+ +----+----+----+---+ +----+----+----+---+ + | d0 | .. | dN | l | | d0 | .. | dN | l | | d0 | .. | dN | f | + +---------+----+-|-+ ^----+----+----+-|-+ ^----+----+----+---+ + | | | | + +----+ +----+ + new_link + +c) DMA hot chaining timeslice issue + +As DMA chaining is done while DMA _is_ running, the linking may be done +while the DMA jumps from one Videobuffer to another. On the schema, that +would be a problem if the following sequence is encountered : + +- DMA chain is Videobuffer1 + Videobuffer2 +- pxa_videobuf_queue() is called to queue Videobuffer3 +- DMA controller finishes Videobuffer2, and DMA stops + +.. code-block:: none + + => + Videobuffer 1 Videobuffer 2 + +---------+----+---+ +----+----+----+---+ + | d0 | .. | dN | l | | d0 | .. | dN | f | + +---------+----+-|-+ ^----+----+----+-^-+ + | | | + +----+ +-- DMA DDADR loads DDADR_STOP + +- pxa_dma_add_tail_buf() is called, the Videobuffer2 "finisher" is + replaced by a "linker" to Videobuffer3 (creation of new_link) +- pxa_videobuf_queue() finishes +- the DMA irq handler is called, which terminates Videobuffer2 +- Videobuffer3 capture is not scheduled on DMA chain (as it stopped !!!) + +.. code-block:: none + + Videobuffer 1 Videobuffer 2 Videobuffer 3 + +---------+----+---+ +----+----+----+---+ +----+----+----+---+ + | d0 | .. | dN | l | | d0 | .. | dN | l | | d0 | .. | dN | f | + +---------+----+-|-+ ^----+----+----+-|-+ ^----+----+----+---+ + | | | | + +----+ +----+ + new_link + DMA DDADR still is DDADR_STOP + +- pxa_camera_check_link_miss() is called + This checks if the DMA is finished and a buffer is still on the + pcdev->capture list. If that's the case, the capture will be restarted, + and Videobuffer3 is scheduled on DMA chain. +- the DMA irq handler finishes + +.. note:: + + If DMA stops just after pxa_camera_check_link_miss() reads DDADR() + value, we have the guarantee that the DMA irq handler will be called back + when the DMA will finish the buffer, and pxa_camera_check_link_miss() will + be called again, to reschedule Videobuffer3. diff --git a/Documentation/driver-api/media/drivers/radiotrack.rst b/Documentation/driver-api/media/drivers/radiotrack.rst new file mode 100644 index 000000000..a85cb6205 --- /dev/null +++ b/Documentation/driver-api/media/drivers/radiotrack.rst @@ -0,0 +1,168 @@ +.. SPDX-License-Identifier: GPL-2.0 + +The Radiotrack radio driver +=========================== + +Author: Stephen M. Benoit <benoits@servicepro.com> + +Date: Dec 14, 1996 + +ACKNOWLEDGMENTS +---------------- + +This document was made based on 'C' code for Linux from Gideon le Grange +(legrang@active.co.za or legrang@cs.sun.ac.za) in 1994, and elaborations from +Frans Brinkman (brinkman@esd.nl) in 1996. The results reported here are from +experiments that the author performed on his own setup, so your mileage may +vary... I make no guarantees, claims or warranties to the suitability or +validity of this information. No other documentation on the AIMS +Lab (http://www.aimslab.com/) RadioTrack card was made available to the +author. This document is offered in the hopes that it might help users who +want to use the RadioTrack card in an environment other than MS Windows. + +WHY THIS DOCUMENT? +------------------ + +I have a RadioTrack card from back when I ran an MS-Windows platform. After +converting to Linux, I found Gideon le Grange's command-line software for +running the card, and found that it was good! Frans Brinkman made a +comfortable X-windows interface, and added a scanning feature. For hack +value, I wanted to see if the tuner could be tuned beyond the usual FM radio +broadcast band, so I could pick up the audio carriers from North American +broadcast TV channels, situated just below and above the 87.0-109.0 MHz range. +I did not get much success, but I learned about programming ioports under +Linux and gained some insights about the hardware design used for the card. + +So, without further delay, here are the details. + + +PHYSICAL DESCRIPTION +-------------------- + +The RadioTrack card is an ISA 8-bit FM radio card. The radio frequency (RF) +input is simply an antenna lead, and the output is a power audio signal +available through a miniature phone plug. Its RF frequencies of operation are +more or less limited from 87.0 to 109.0 MHz (the commercial FM broadcast +band). Although the registers can be programmed to request frequencies beyond +these limits, experiments did not give promising results. The variable +frequency oscillator (VFO) that demodulates the intermediate frequency (IF) +signal probably has a small range of useful frequencies, and wraps around or +gets clipped beyond the limits mentioned above. + + +CONTROLLING THE CARD WITH IOPORT +-------------------------------- + +The RadioTrack (base) ioport is configurable for 0x30c or 0x20c. Only one +ioport seems to be involved. The ioport decoding circuitry must be pretty +simple, as individual ioport bits are directly matched to specific functions +(or blocks) of the radio card. This way, many functions can be changed in +parallel with one write to the ioport. The only feedback available through +the ioports appears to be the "Stereo Detect" bit. + +The bits of the ioport are arranged as follows: + +.. code-block:: none + + MSb LSb + +------+------+------+--------+--------+-------+---------+--------+ + | VolA | VolB | ???? | Stereo | Radio | TuneA | TuneB | Tune | + | (+) | (-) | | Detect | Audio | (bit) | (latch) | Update | + | | | | Enable | Enable | | | Enable | + +------+------+------+--------+--------+-------+---------+--------+ + + +==== ==== ================================= +VolA VolB Description +==== ==== ================================= +0 0 audio mute +0 1 volume + (some delay required) +1 0 volume - (some delay required) +1 1 stay at present volume +==== ==== ================================= + +==================== =========== +Stereo Detect Enable Description +==================== =========== +0 No Detect +1 Detect +==================== =========== + +Results available by reading ioport >60 msec after last port write. + + 0xff ==> no stereo detected, 0xfd ==> stereo detected. + +============================= ============================= +Radio to Audio (path) Enable Description +============================= ============================= +0 Disable path (silence) +1 Enable path (audio produced) +============================= ============================= + +===== ===== ================== +TuneA TuneB Description +===== ===== ================== +0 0 "zero" bit phase 1 +0 1 "zero" bit phase 2 +1 0 "one" bit phase 1 +1 1 "one" bit phase 2 +===== ===== ================== + + +24-bit code, where bits = (freq*40) + 10486188. +The Most Significant 11 bits must be 1010 xxxx 0x0 to be valid. +The bits are shifted in LSb first. + +================== =========================== +Tune Update Enable Description +================== =========================== +0 Tuner held constant +1 Tuner updating in progress +================== =========================== + + +PROGRAMMING EXAMPLES +-------------------- + +.. code-block:: none + + Default: BASE <-- 0xc8 (current volume, no stereo detect, + radio enable, tuner adjust disable) + + Card Off: BASE <-- 0x00 (audio mute, no stereo detect, + radio disable, tuner adjust disable) + + Card On: BASE <-- 0x00 (see "Card Off", clears any unfinished business) + BASE <-- 0xc8 (see "Default") + + Volume Down: BASE <-- 0x48 (volume down, no stereo detect, + radio enable, tuner adjust disable) + wait 10 msec + BASE <-- 0xc8 (see "Default") + + Volume Up: BASE <-- 0x88 (volume up, no stereo detect, + radio enable, tuner adjust disable) + wait 10 msec + BASE <-- 0xc8 (see "Default") + + Check Stereo: BASE <-- 0xd8 (current volume, stereo detect, + radio enable, tuner adjust disable) + wait 100 msec + x <-- BASE (read ioport) + BASE <-- 0xc8 (see "Default") + + x=0xff ==> "not stereo", x=0xfd ==> "stereo detected" + + Set Frequency: code = (freq*40) + 10486188 + foreach of the 24 bits in code, + (from Least to Most Significant): + to write a "zero" bit, + BASE <-- 0x01 (audio mute, no stereo detect, radio + disable, "zero" bit phase 1, tuner adjust) + BASE <-- 0x03 (audio mute, no stereo detect, radio + disable, "zero" bit phase 2, tuner adjust) + to write a "one" bit, + BASE <-- 0x05 (audio mute, no stereo detect, radio + disable, "one" bit phase 1, tuner adjust) + BASE <-- 0x07 (audio mute, no stereo detect, radio + disable, "one" bit phase 2, tuner adjust) diff --git a/Documentation/driver-api/media/drivers/rkisp1.rst b/Documentation/driver-api/media/drivers/rkisp1.rst new file mode 100644 index 000000000..ea336958a --- /dev/null +++ b/Documentation/driver-api/media/drivers/rkisp1.rst @@ -0,0 +1,43 @@ +.. SPDX-License-Identifier: GPL-2.0 + +The Rockchip Image Signal Processor Driver (rkisp1) +=================================================== + +Versions and their differences +------------------------------ + +The rkisp1 block underwent some changes between SoC implementations. +The vendor designates them as: + +- V10: used at least in rk3288 and rk3399 +- V11: declared in the original vendor code, but not used +- V12: used at least in rk3326 and px30 +- V13: used at least in rk1808 +- V20: used in rk3568 and beyond + +Right now the kernel supports rkisp1 implementations based +on V10 and V12 variants. V11 does not seem to be actually used +and V13 will need some more additions but isn't researched yet, +especially as it seems to be limited to the rk1808 which hasn't +reached much market spread. + +V20 on the other hand will probably be used in future SoCs and +has seen really big changes in the vendor kernel, so will need +quite a bit of research. + +Changes from V10 to V12 +----------------------- + +- V12 supports a new CSI-host implementation but can still + also use the same implementation from V10 +- The module for lens shading correction got changed + from 12bit to 13bit width +- The AWB and AEC modules got replaced to support finer + grained data collection + +Changes from V12 to V13 +----------------------- + +The list for V13 is incomplete and needs further investigation. + +- V13 does not support the old CSI-host implementation anymore diff --git a/Documentation/driver-api/media/drivers/saa7134-devel.rst b/Documentation/driver-api/media/drivers/saa7134-devel.rst new file mode 100644 index 000000000..167fd729b --- /dev/null +++ b/Documentation/driver-api/media/drivers/saa7134-devel.rst @@ -0,0 +1,67 @@ +.. SPDX-License-Identifier: GPL-2.0 + +The saa7134 driver +================== + +Author Gerd Hoffmann + + +Card Variations: +---------------- + +Cards can use either of these two crystals (xtal): + +- 32.11 MHz -> .audio_clock=0x187de7 +- 24.576MHz -> .audio_clock=0x200000 (xtal * .audio_clock = 51539600) + +Some details about 30/34/35: + +- saa7130 - low-price chip, doesn't have mute, that is why all those + cards should have .mute field defined in their tuner structure. + +- saa7134 - usual chip + +- saa7133/35 - saa7135 is probably a marketing decision, since all those + chips identifies itself as 33 on pci. + +LifeView GPIOs +-------------- + +This section was authored by: Peter Missel <peter.missel@onlinehome.de> + +- LifeView FlyTV Platinum FM (LR214WF) + + - GP27 MDT2005 PB4 pin 10 + - GP26 MDT2005 PB3 pin 9 + - GP25 MDT2005 PB2 pin 8 + - GP23 MDT2005 PB1 pin 7 + - GP22 MDT2005 PB0 pin 6 + - GP21 MDT2005 PB5 pin 11 + - GP20 MDT2005 PB6 pin 12 + - GP19 MDT2005 PB7 pin 13 + - nc MDT2005 PA3 pin 2 + - Remote MDT2005 PA2 pin 1 + - GP18 MDT2005 PA1 pin 18 + - nc MDT2005 PA0 pin 17 strap low + - GP17 Strap "GP7"=High + - GP16 Strap "GP6"=High + + - 0=Radio 1=TV + - Drives SA630D ENCH1 and HEF4052 A1 pinsto do FM radio through + SIF input + + - GP15 nc + - GP14 nc + - GP13 nc + - GP12 Strap "GP5" = High + - GP11 Strap "GP4" = High + - GP10 Strap "GP3" = High + - GP09 Strap "GP2" = Low + - GP08 Strap "GP1" = Low + - GP07.00 nc + +Credits +------- + +andrew.stevens@philips.com + werner.leeb@philips.com for providing +saa7134 hardware specs and sample board. diff --git a/Documentation/driver-api/media/drivers/sh_mobile_ceu_camera.rst b/Documentation/driver-api/media/drivers/sh_mobile_ceu_camera.rst new file mode 100644 index 000000000..822fcb836 --- /dev/null +++ b/Documentation/driver-api/media/drivers/sh_mobile_ceu_camera.rst @@ -0,0 +1,142 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Cropping and Scaling algorithm, used in the sh_mobile_ceu_camera driver +======================================================================= + +Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de> + +Terminology +----------- + +sensor scales: horizontal and vertical scales, configured by the sensor driver +host scales: -"- host driver +combined scales: sensor_scale * host_scale + + +Generic scaling / cropping scheme +--------------------------------- + +.. code-block:: none + + -1-- + | + -2-- -\ + | --\ + | --\ + +-5-- . -- -3-- -\ + | `... -\ + | `... -4-- . - -7.. + | `. + | `. .6-- + | + | . .6'- + | .´ + | ... -4'- .´ + | ...´ - -7'. + +-5'- .´ -/ + | -- -3'- -/ + | --/ + | --/ + -2'- -/ + | + | + -1'- + +In the above chart minuses and slashes represent "real" data amounts, points and +accents represent "useful" data, basically, CEU scaled and cropped output, +mapped back onto the client's source plane. + +Such a configuration can be produced by user requests: + +S_CROP(left / top = (5) - (1), width / height = (5') - (5)) +S_FMT(width / height = (6') - (6)) + +Here: + +(1) to (1') - whole max width or height +(1) to (2) - sensor cropped left or top +(2) to (2') - sensor cropped width or height +(3) to (3') - sensor scale +(3) to (4) - CEU cropped left or top +(4) to (4') - CEU cropped width or height +(5) to (5') - reverse sensor scale applied to CEU cropped width or height +(2) to (5) - reverse sensor scale applied to CEU cropped left or top +(6) to (6') - CEU scale - user window + + +S_FMT +----- + +Do not touch input rectangle - it is already optimal. + +1. Calculate current sensor scales: + + scale_s = ((2') - (2)) / ((3') - (3)) + +2. Calculate "effective" input crop (sensor subwindow) - CEU crop scaled back at +current sensor scales onto input window - this is user S_CROP: + + width_u = (5') - (5) = ((4') - (4)) * scale_s + +3. Calculate new combined scales from "effective" input window to requested user +window: + + scale_comb = width_u / ((6') - (6)) + +4. Calculate sensor output window by applying combined scales to real input +window: + + width_s_out = ((7') - (7)) = ((2') - (2)) / scale_comb + +5. Apply iterative sensor S_FMT for sensor output window. + + subdev->video_ops->s_fmt(.width = width_s_out) + +6. Retrieve sensor output window (g_fmt) + +7. Calculate new sensor scales: + + scale_s_new = ((3')_new - (3)_new) / ((2') - (2)) + +8. Calculate new CEU crop - apply sensor scales to previously calculated +"effective" crop: + + width_ceu = (4')_new - (4)_new = width_u / scale_s_new + left_ceu = (4)_new - (3)_new = ((5) - (2)) / scale_s_new + +9. Use CEU cropping to crop to the new window: + + ceu_crop(.width = width_ceu, .left = left_ceu) + +10. Use CEU scaling to scale to the requested user window: + + scale_ceu = width_ceu / width + + +S_CROP +------ + +The :ref:`V4L2 crop API <crop-scale>` says: + +"...specification does not define an origin or units. However by convention +drivers should horizontally count unscaled samples relative to 0H." + +We choose to follow the advise and interpret cropping units as client input +pixels. + +Cropping is performed in the following 6 steps: + +1. Request exactly user rectangle from the sensor. + +2. If smaller - iterate until a larger one is obtained. Result: sensor cropped + to 2 : 2', target crop 5 : 5', current output format 6' - 6. + +3. In the previous step the sensor has tried to preserve its output frame as + good as possible, but it could have changed. Retrieve it again. + +4. Sensor scaled to 3 : 3'. Sensor's scale is (2' - 2) / (3' - 3). Calculate + intermediate window: 4' - 4 = (5' - 5) * (3' - 3) / (2' - 2) + +5. Calculate and apply host scale = (6' - 6) / (4' - 4) + +6. Calculate and apply host crop: 6 - 7 = (5 - 2) * (6' - 6) / (5' - 5) diff --git a/Documentation/driver-api/media/drivers/tuners.rst b/Documentation/driver-api/media/drivers/tuners.rst new file mode 100644 index 000000000..d7924141c --- /dev/null +++ b/Documentation/driver-api/media/drivers/tuners.rst @@ -0,0 +1,133 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Tuner drivers +============= + +Simple tuner Programming +------------------------ + +There are some flavors of Tuner programming APIs. +These differ mainly by the bandswitch byte. + +- L= LG_API (VHF_LO=0x01, VHF_HI=0x02, UHF=0x08, radio=0x04) +- P= PHILIPS_API (VHF_LO=0xA0, VHF_HI=0x90, UHF=0x30, radio=0x04) +- T= TEMIC_API (VHF_LO=0x02, VHF_HI=0x04, UHF=0x01) +- A= ALPS_API (VHF_LO=0x14, VHF_HI=0x12, UHF=0x11) +- M= PHILIPS_MK3 (VHF_LO=0x01, VHF_HI=0x02, UHF=0x04, radio=0x19) + +Tuner Manufacturers +------------------- + +- Samsung Tuner identification: (e.g. TCPM9091PD27) + +.. code-block:: none + + TCP [ABCJLMNQ] 90[89][125] [DP] [ACD] 27 [ABCD] + [ABCJLMNQ]: + A= BG+DK + B= BG + C= I+DK + J= NTSC-Japan + L= Secam LL + M= BG+I+DK + N= NTSC + Q= BG+I+DK+LL + [89]: ? + [125]: + 2: No FM + 5: With FM + [DP]: + D= NTSC + P= PAL + [ACD]: + A= F-connector + C= Phono connector + D= Din Jack + [ABCD]: + 3-wire/I2C tuning, 2-band/3-band + +These Tuners are PHILIPS_API compatible. + +Philips Tuner identification: (e.g. FM1216MF) + +.. code-block:: none + + F[IRMQ]12[1345]6{MF|ME|MP} + F[IRMQ]: + FI12x6: Tuner Series + FR12x6: Tuner + Radio IF + FM12x6: Tuner + FM + FQ12x6: special + FMR12x6: special + TD15xx: Digital Tuner ATSC + 12[1345]6: + 1216: PAL BG + 1236: NTSC + 1246: PAL I + 1256: Pal DK + {MF|ME|MP} + MF: BG LL w/ Secam (Multi France) + ME: BG DK I LL (Multi Europe) + MP: BG DK I (Multi PAL) + MR: BG DK M (?) + MG: BG DKI M (?) + MK2 series PHILIPS_API, most tuners are compatible to this one ! + MK3 series introduced in 2002 w/ PHILIPS_MK3_API + +Temic Tuner identification: (.e.g 4006FH5) + +.. code-block:: none + + 4[01][0136][269]F[HYNR]5 + 40x2: Tuner (5V/33V), TEMIC_API. + 40x6: Tuner 5V + 41xx: Tuner compact + 40x9: Tuner+FM compact + [0136] + xx0x: PAL BG + xx1x: Pal DK, Secam LL + xx3x: NTSC + xx6x: PAL I + F[HYNR]5 + FH5: Pal BG + FY5: others + FN5: multistandard + FR5: w/ FM radio + 3X xxxx: order number with specific connector + Note: Only 40x2 series has TEMIC_API, all newer tuners have PHILIPS_API. + +LG Innotek Tuner: + +- TPI8NSR11 : NTSC J/M (TPI8NSR01 w/FM) (P,210/497) +- TPI8PSB11 : PAL B/G (TPI8PSB01 w/FM) (P,170/450) +- TAPC-I701 : PAL I (TAPC-I001 w/FM) (P,170/450) +- TPI8PSB12 : PAL D/K+B/G (TPI8PSB02 w/FM) (P,170/450) +- TAPC-H701P: NTSC_JP (TAPC-H001P w/FM) (L,170/450) +- TAPC-G701P: PAL B/G (TAPC-G001P w/FM) (L,170/450) +- TAPC-W701P: PAL I (TAPC-W001P w/FM) (L,170/450) +- TAPC-Q703P: PAL D/K (TAPC-Q001P w/FM) (L,170/450) +- TAPC-Q704P: PAL D/K+I (L,170/450) +- TAPC-G702P: PAL D/K+B/G (L,170/450) + +- TADC-H002F: NTSC (L,175/410?; 2-B, C-W+11, W+12-69) +- TADC-M201D: PAL D/K+B/G+I (L,143/425) (sound control at I2C address 0xc8) +- TADC-T003F: NTSC Taiwan (L,175/410?; 2-B, C-W+11, W+12-69) + +Suffix: + - P= Standard phono female socket + - D= IEC female socket + - F= F-connector + +Other Tuners: + +- TCL2002MB-1 : PAL BG + DK =TUNER_LG_PAL_NEW_TAPC +- TCL2002MB-1F: PAL BG + DK w/FM =PHILIPS_PAL +- TCL2002MI-2 : PAL I = ?? + +ALPS Tuners: + +- Most are LG_API compatible +- TSCH6 has ALPS_API (TSCH5 ?) +- TSBE1 has extra API 05,02,08 Control_byte=0xCB Source:[#f1]_ + +.. [#f1] conexant100029b-PCI-Decoder-ApplicationNote.pdf diff --git a/Documentation/driver-api/media/drivers/vidtv.rst b/Documentation/driver-api/media/drivers/vidtv.rst new file mode 100644 index 000000000..54f269f47 --- /dev/null +++ b/Documentation/driver-api/media/drivers/vidtv.rst @@ -0,0 +1,513 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================================ +vidtv: Virtual Digital TV driver +================================ + +Author: Daniel W. S. Almeida <dwlsalmeida@gmail.com>, June 2020. + +Background +---------- + +Vidtv is a virtual DVB driver that aims to serve as a reference for driver +writers by serving as a template. It also validates the existing media DVB +APIs, thus helping userspace application writers. + +Currently, it consists of: + +- A fake tuner driver, which will report a bad signal quality if the chosen + frequency is too far away from a table of valid frequencies for a + particular delivery system. + +- A fake demod driver, which will constantly poll the fake signal quality + returned by the tuner, simulating a device that can lose/reacquire a lock + on the signal depending on the CNR levels. + +- A fake bridge driver, which is the module responsible for modprobing the + fake tuner and demod modules and implementing the demux logic. This module + takes parameters at initialization that will dictate how the simulation + behaves. + +- Code responsible for encoding a valid MPEG Transport Stream, which is then + passed to the bridge driver. This fake stream contains some hardcoded content. + For now, we have a single, audio-only channel containing a single MPEG + Elementary Stream, which in turn contains a SMPTE 302m encoded sine-wave. + Note that this particular encoder was chosen because it is the easiest + way to encode PCM audio data in a MPEG Transport Stream. + +Building vidtv +-------------- +vidtv is a test driver and thus is **not** enabled by default when +compiling the kernel. + +In order to enable compilation of vidtv: + +- Enable **DVB_TEST_DRIVERS**, then +- Enable **DVB_VIDTV** + +When compiled as a module, expect the following .ko files: + +- dvb_vidtv_tuner.ko + +- dvb_vidtv_demod.ko + +- dvb_vidtv_bridge.ko + +Running vidtv +------------- +When compiled as a module, run:: + + modprobe vidtv + +That's it! The bridge driver will initialize the tuner and demod drivers as +part of its own initialization. + +By default, it will accept the following frequencies: + + - 474 MHz for DVB-T/T2/C; + - 11,362 GHz for DVB-S/S2. + +For satellite systems, the driver simulates an universal extended +LNBf, with frequencies at Ku-Band, ranging from 10.7 GHz to 12.75 GHz. + +You can optionally define some command-line arguments to vidtv. + +Command-line arguments to vidtv +------------------------------- +Below is a list of all arguments that can be supplied to vidtv: + +drop_tslock_prob_on_low_snr + Probability of losing the TS lock if the signal quality is bad. + This probability be used by the fake demodulator driver to + eventually return a status of 0 when the signal quality is not + good. + +recover_tslock_prob_on_good_snr: + Probability recovering the TS lock when the signal improves. This + probability be used by the fake demodulator driver to eventually + return a status of 0x1f when/if the signal quality improves. + +mock_power_up_delay_msec + Simulate a power up delay. Default: 0. + +mock_tune_delay_msec + Simulate a tune delay. Default 0. + +vidtv_valid_dvb_t_freqs + Valid DVB-T frequencies to simulate, in Hz. + +vidtv_valid_dvb_c_freqs + Valid DVB-C frequencies to simulate, in Hz. + +vidtv_valid_dvb_s_freqs + Valid DVB-S/S2 frequencies to simulate at Ku-Band, in kHz. + +max_frequency_shift_hz, + Maximum shift in HZ allowed when tuning in a channel. + +si_period_msec + How often to send SI packets. Default: 40ms. + +pcr_period_msec + How often to send PCR packets. Default: 40ms. + +mux_rate_kbytes_sec + Attempt to maintain this bit rate by inserting TS null packets, if + necessary. Default: 4096. + +pcr_pid, + PCR PID for all channels. Default: 0x200. + +mux_buf_sz_pkts, + Size for the mux buffer in multiples of 188 bytes. + +vidtv internal structure +------------------------ +The kernel modules are split in the following way: + +vidtv_tuner.[ch] + Implements a fake tuner DVB driver. + +vidtv_demod.[ch] + Implements a fake demodulator DVB driver. + +vidtv_bridge.[ch] + Implements a bridge driver. + +The MPEG related code is split in the following way: + +vidtv_ts.[ch] + Code to work with MPEG TS packets, such as TS headers, adaptation + fields, PCR packets and NULL packets. + +vidtv_psi.[ch] + This is the PSI generator. PSI packets contain general information + about a MPEG Transport Stream. A PSI generator is needed so + userspace apps can retrieve information about the Transport Stream + and eventually tune into a (dummy) channel. + + Because the generator is implemented in a separate file, it can be + reused elsewhere in the media subsystem. + + Currently vidtv supports working with 5 PSI tables: PAT, PMT, + SDT, NIT and EIT. + + The specification for PAT and PMT can be found in *ISO 13818-1: + Systems*, while the specification for the SDT, NIT, EIT can be found in *ETSI + EN 300 468: Specification for Service Information (SI) in DVB + systems*. + + It isn't strictly necessary, but using a real TS file helps when + debugging PSI tables. Vidtv currently tries to replicate the PSI + structure found in this file: `TS1Globo.ts + <https://tsduck.io/streams/brazil-isdb-tb/TS1globo.ts>`_. + + A good way to visualize the structure of streams is by using + `DVBInspector <https://sourceforge.net/projects/dvbinspector/>`_. + +vidtv_pes.[ch] + Implements the PES logic to convert encoder data into MPEG TS + packets. These can then be fed into a TS multiplexer and eventually + into userspace. + +vidtv_encoder.h + An interface for vidtv encoders. New encoders can be added to this + driver by implementing the calls in this file. + +vidtv_s302m.[ch] + Implements a S302M encoder to make it possible to insert PCM audio + data in the generated MPEG Transport Stream. The relevant + specification is available online as *SMPTE 302M-2007: Television - + Mapping of AES3 Data into MPEG-2 Transport Stream*. + + + The resulting MPEG Elementary Stream is conveyed in a private + stream with a S302M registration descriptor attached. + + This shall enable passing an audio signal into userspace so it can + be decoded and played by media software. The corresponding decoder + in ffmpeg is located in 'libavcodec/s302m.c' and is experimental. + +vidtv_channel.[ch] + Implements a 'channel' abstraction. + + When vidtv boots, it will create some hardcoded channels: + + #. Their services will be concatenated to populate the SDT. + + #. Their programs will be concatenated to populate the PAT + + #. Their events will be concatenated to populate the EIT + + #. For each program in the PAT, a PMT section will be created + + #. The PMT section for a channel will be assigned its streams. + + #. Every stream will have its corresponding encoder polled in a + loop to produce TS packets. + These packets may be interleaved by the muxer and then delivered + to the bridge. + +vidtv_mux.[ch] + Implements a MPEG TS mux, loosely based on the ffmpeg + implementation in "libavcodec/mpegtsenc.c" + + The muxer runs a loop which is responsible for: + + #. Keeping track of the amount of time elapsed since the last + iteration. + + #. Polling encoders in order to fetch 'elapsed_time' worth of data. + + #. Inserting PSI and/or PCR packets, if needed. + + #. Padding the resulting stream with NULL packets if + necessary in order to maintain the chosen bit rate. + + #. Delivering the resulting TS packets to the bridge + driver so it can pass them to the demux. + +Testing vidtv with v4l-utils +---------------------------- + +Using the tools in v4l-utils is a great way to test and inspect the output of +vidtv. It is hosted here: `v4l-utils Documentation +<https://linuxtv.org/wiki/index.php/V4l-utils>`_. + +From its webpage:: + + The v4l-utils are a series of packages for handling media devices. + + It is hosted at http://git.linuxtv.org/v4l-utils.git, and packaged + on most distributions. + + It provides a series of libraries and utilities to be used to + control several aspect of the media boards. + + +Start by installing v4l-utils and then modprobing vidtv:: + + modprobe dvb_vidtv_bridge + +If the driver is OK, it should load and its probing code will run. This will +pull in the tuner and demod drivers. + +Using dvb-fe-tool +~~~~~~~~~~~~~~~~~ + +The first step to check whether the demod loaded successfully is to run:: + + $ dvb-fe-tool + Device Dummy demod for DVB-T/T2/C/S/S2 (/dev/dvb/adapter0/frontend0) capabilities: + CAN_FEC_1_2 + CAN_FEC_2_3 + CAN_FEC_3_4 + CAN_FEC_4_5 + CAN_FEC_5_6 + CAN_FEC_6_7 + CAN_FEC_7_8 + CAN_FEC_8_9 + CAN_FEC_AUTO + CAN_GUARD_INTERVAL_AUTO + CAN_HIERARCHY_AUTO + CAN_INVERSION_AUTO + CAN_QAM_16 + CAN_QAM_32 + CAN_QAM_64 + CAN_QAM_128 + CAN_QAM_256 + CAN_QAM_AUTO + CAN_QPSK + CAN_TRANSMISSION_MODE_AUTO + DVB API Version 5.11, Current v5 delivery system: DVBC/ANNEX_A + Supported delivery systems: + DVBT + DVBT2 + [DVBC/ANNEX_A] + DVBS + DVBS2 + Frequency range for the current standard: + From: 51.0 MHz + To: 2.15 GHz + Step: 62.5 kHz + Tolerance: 29.5 MHz + Symbol rate ranges for the current standard: + From: 1.00 MBauds + To: 45.0 MBauds + +This should return what is currently set up at the demod struct, i.e.:: + + static const struct dvb_frontend_ops vidtv_demod_ops = { + .delsys = { + SYS_DVBT, + SYS_DVBT2, + SYS_DVBC_ANNEX_A, + SYS_DVBS, + SYS_DVBS2, + }, + + .info = { + .name = "Dummy demod for DVB-T/T2/C/S/S2", + .frequency_min_hz = 51 * MHz, + .frequency_max_hz = 2150 * MHz, + .frequency_stepsize_hz = 62500, + .frequency_tolerance_hz = 29500 * kHz, + .symbol_rate_min = 1000000, + .symbol_rate_max = 45000000, + + .caps = FE_CAN_FEC_1_2 | + FE_CAN_FEC_2_3 | + FE_CAN_FEC_3_4 | + FE_CAN_FEC_4_5 | + FE_CAN_FEC_5_6 | + FE_CAN_FEC_6_7 | + FE_CAN_FEC_7_8 | + FE_CAN_FEC_8_9 | + FE_CAN_QAM_16 | + FE_CAN_QAM_64 | + FE_CAN_QAM_32 | + FE_CAN_QAM_128 | + FE_CAN_QAM_256 | + FE_CAN_QAM_AUTO | + FE_CAN_QPSK | + FE_CAN_FEC_AUTO | + FE_CAN_INVERSION_AUTO | + FE_CAN_TRANSMISSION_MODE_AUTO | + FE_CAN_GUARD_INTERVAL_AUTO | + FE_CAN_HIERARCHY_AUTO, + } + + .... + +For more information on dvb-fe-tools check its online documentation here: +`dvb-fe-tool Documentation +<https://www.linuxtv.org/wiki/index.php/Dvb-fe-tool>`_. + +Using dvb-scan +~~~~~~~~~~~~~~ + +In order to tune into a channel and read the PSI tables, we can use dvb-scan. + +For this, one should provide a configuration file known as a 'scan file', +here's an example:: + + [Channel] + FREQUENCY = 474000000 + MODULATION = QAM/AUTO + SYMBOL_RATE = 6940000 + INNER_FEC = AUTO + DELIVERY_SYSTEM = DVBC/ANNEX_A + +.. note:: + The parameters depend on the video standard you're testing. + +.. note:: + Vidtv is a fake driver and does not validate much of the information + in the scan file. Just specifying 'FREQUENCY' and 'DELIVERY_SYSTEM' + should be enough for DVB-T/DVB-T2. For DVB-S/DVB-C however, you + should also provide 'SYMBOL_RATE'. + +You can browse scan tables online here: `dvb-scan-tables +<https://git.linuxtv.org/dtv-scan-tables.git>`_. + +Assuming this channel is named 'channel.conf', you can then run:: + + $ dvbv5-scan channel.conf + dvbv5-scan ~/vidtv.conf + ERROR command BANDWIDTH_HZ (5) not found during retrieve + Cannot calc frequency shift. Either bandwidth/symbol-rate is unavailable (yet). + Scanning frequency #1 330000000 + (0x00) Signal= -68.00dBm + Scanning frequency #2 474000000 + Lock (0x1f) Signal= -34.45dBm C/N= 33.74dB UCB= 0 + Service Beethoven, provider LinuxTV.org: digital television + +For more information on dvb-scan, check its documentation online here: +`dvb-scan Documentation <https://www.linuxtv.org/wiki/index.php/Dvbscan>`_. + +Using dvb-zap +~~~~~~~~~~~~~ + +dvbv5-zap is a command line tool that can be used to record MPEG-TS to disk. The +typical use is to tune into a channel and put it into record mode. The example +below - which is taken from the documentation - illustrates that\ [1]_:: + + $ dvbv5-zap -c dvb_channel.conf "beethoven" -o music.ts -P -t 10 + using demux 'dvb0.demux0' + reading channels from file 'dvb_channel.conf' + tuning to 474000000 Hz + pass all PID's to TS + dvb_set_pesfilter 8192 + dvb_dev_set_bufsize: buffer set to 6160384 + Lock (0x1f) Quality= Good Signal= -34.66dBm C/N= 33.41dB UCB= 0 postBER= 0 preBER= 1.05x10^-3 PER= 0 + Lock (0x1f) Quality= Good Signal= -34.57dBm C/N= 33.46dB UCB= 0 postBER= 0 preBER= 1.05x10^-3 PER= 0 + Record to file 'music.ts' started + received 24587768 bytes (2401 Kbytes/sec) + Lock (0x1f) Quality= Good Signal= -34.42dBm C/N= 33.89dB UCB= 0 postBER= 0 preBER= 2.44x10^-3 PER= 0 + +.. [1] In this example, it records 10 seconds with all program ID's stored + at the music.ts file. + + +The channel can be watched by playing the contents of the stream with some +player that recognizes the MPEG-TS format, such as ``mplayer`` or ``vlc``. + +By playing the contents of the stream one can visually inspect the workings of +vidtv, e.g., to play a recorded TS file with:: + + $ mplayer music.ts + +or, alternatively, running this command on one terminal:: + + $ dvbv5-zap -c dvb_channel.conf "beethoven" -P -r & + +And, on a second terminal, playing the contents from DVR interface with:: + + $ mplayer /dev/dvb/adapter0/dvr0 + +For more information on dvb-zap check its online documentation here: +`dvb-zap Documentation +<https://www.linuxtv.org/wiki/index.php/Dvbv5-zap>`_. +See also: `zap <https://www.linuxtv.org/wiki/index.php/Zap>`_. + + +What can still be improved in vidtv +----------------------------------- + +Add *debugfs* integration +~~~~~~~~~~~~~~~~~~~~~~~~~ + +Although frontend drivers provide DVBv5 statistics via the .read_status +call, a nice addition would be to make additional statistics available to +userspace via debugfs, which is a simple-to-use, RAM-based filesystem +specifically designed for debug purposes. + +The logic for this would be implemented on a separate file so as not to +pollute the frontend driver. These statistics are driver-specific and can +be useful during tests. + +The Siano driver is one example of a driver using +debugfs to convey driver-specific statistics to userspace and it can be +used as a reference. + +This should be further enabled and disabled via a Kconfig +option for convenience. + +Add a way to test video +~~~~~~~~~~~~~~~~~~~~~~~ + +Currently, vidtv can only encode PCM audio. It would be great to implement +a barebones version of MPEG-2 video encoding so we can also test video. The +first place to look into is *ISO 13818-2: Information technology — Generic +coding of moving pictures and associated audio information — Part 2: Video*, +which covers the encoding of compressed video in MPEG Transport Streams. + +This might optionally use the Video4Linux2 Test Pattern Generator, v4l2-tpg, +which resides at:: + + drivers/media/common/v4l2-tpg/ + + +Add white noise simulation +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The vidtv tuner already has code to identify whether the chosen frequency +is too far away from a table of valid frequencies. For now, this means that +the demodulator can eventually lose the lock on the signal, since the tuner will +report a bad signal quality. + +A nice addition is to simulate some noise when the signal quality is bad by: + +- Randomly dropping some TS packets. This will trigger a continuity error if the + continuity counter is updated but the packet is not passed on to the demux. + +- Updating the error statistics accordingly (e.g. BER, etc). + +- Simulating some noise in the encoded data. + +Functions and structs used within vidtv +--------------------------------------- + +.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_bridge.h + +.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_channel.h + +.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_demod.h + +.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_encoder.h + +.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_mux.h + +.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_pes.h + +.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_psi.h + +.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_s302m.h + +.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_ts.h + +.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_tuner.h + +.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_common.c + +.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_tuner.c diff --git a/Documentation/driver-api/media/drivers/vimc-devel.rst b/Documentation/driver-api/media/drivers/vimc-devel.rst new file mode 100644 index 000000000..9e984f914 --- /dev/null +++ b/Documentation/driver-api/media/drivers/vimc-devel.rst @@ -0,0 +1,15 @@ +.. SPDX-License-Identifier: GPL-2.0 + +The Virtual Media Controller Driver (vimc) +========================================== + +Source code documentation +------------------------- + +vimc-streamer +~~~~~~~~~~~~~ + +.. kernel-doc:: drivers/media/test-drivers/vimc/vimc-streamer.h + :internal: + +.. kernel-doc:: drivers/media/test-drivers/vimc/vimc-streamer.c diff --git a/Documentation/driver-api/media/drivers/zoran.rst b/Documentation/driver-api/media/drivers/zoran.rst new file mode 100644 index 000000000..2538473c3 --- /dev/null +++ b/Documentation/driver-api/media/drivers/zoran.rst @@ -0,0 +1,575 @@ +.. SPDX-License-Identifier: GPL-2.0 + +The Zoran driver +================ + +unified zoran driver (zr360x7, zoran, buz, dc10(+), dc30(+), lml33) + +website: http://mjpeg.sourceforge.net/driver-zoran/ + + +Frequently Asked Questions +-------------------------- + +What cards are supported +------------------------ + +Iomega Buz, Linux Media Labs LML33/LML33R10, Pinnacle/Miro +DC10/DC10+/DC30/DC30+ and related boards (available under various names). + +Iomega Buz +~~~~~~~~~~ + +* Zoran zr36067 PCI controller +* Zoran zr36060 MJPEG codec +* Philips saa7111 TV decoder +* Philips saa7185 TV encoder + +Drivers to use: videodev, i2c-core, i2c-algo-bit, +videocodec, saa7111, saa7185, zr36060, zr36067 + +Inputs/outputs: Composite and S-video + +Norms: PAL, SECAM (720x576 @ 25 fps), NTSC (720x480 @ 29.97 fps) + +Card number: 7 + +AverMedia 6 Eyes AVS6EYES +~~~~~~~~~~~~~~~~~~~~~~~~~ + +* Zoran zr36067 PCI controller +* Zoran zr36060 MJPEG codec +* Samsung ks0127 TV decoder +* Conexant bt866 TV encoder + +Drivers to use: videodev, i2c-core, i2c-algo-bit, +videocodec, ks0127, bt866, zr36060, zr36067 + +Inputs/outputs: + Six physical inputs. 1-6 are composite, + 1-2, 3-4, 5-6 doubles as S-video, + 1-3 triples as component. + One composite output. + +Norms: PAL, SECAM (720x576 @ 25 fps), NTSC (720x480 @ 29.97 fps) + +Card number: 8 + +.. note:: + + Not autodetected, card=8 is necessary. + +Linux Media Labs LML33 +~~~~~~~~~~~~~~~~~~~~~~ + +* Zoran zr36067 PCI controller +* Zoran zr36060 MJPEG codec +* Brooktree bt819 TV decoder +* Brooktree bt856 TV encoder + +Drivers to use: videodev, i2c-core, i2c-algo-bit, +videocodec, bt819, bt856, zr36060, zr36067 + +Inputs/outputs: Composite and S-video + +Norms: PAL (720x576 @ 25 fps), NTSC (720x480 @ 29.97 fps) + +Card number: 5 + +Linux Media Labs LML33R10 +~~~~~~~~~~~~~~~~~~~~~~~~~ + +* Zoran zr36067 PCI controller +* Zoran zr36060 MJPEG codec +* Philips saa7114 TV decoder +* Analog Devices adv7170 TV encoder + +Drivers to use: videodev, i2c-core, i2c-algo-bit, +videocodec, saa7114, adv7170, zr36060, zr36067 + +Inputs/outputs: Composite and S-video + +Norms: PAL (720x576 @ 25 fps), NTSC (720x480 @ 29.97 fps) + +Card number: 6 + +Pinnacle/Miro DC10(new) +~~~~~~~~~~~~~~~~~~~~~~~ + +* Zoran zr36057 PCI controller +* Zoran zr36060 MJPEG codec +* Philips saa7110a TV decoder +* Analog Devices adv7176 TV encoder + +Drivers to use: videodev, i2c-core, i2c-algo-bit, +videocodec, saa7110, adv7175, zr36060, zr36067 + +Inputs/outputs: Composite, S-video and Internal + +Norms: PAL, SECAM (768x576 @ 25 fps), NTSC (640x480 @ 29.97 fps) + +Card number: 1 + +Pinnacle/Miro DC10+ +~~~~~~~~~~~~~~~~~~~ + +* Zoran zr36067 PCI controller +* Zoran zr36060 MJPEG codec +* Philips saa7110a TV decoder +* Analog Devices adv7176 TV encoder + +Drivers to use: videodev, i2c-core, i2c-algo-bit, +videocodec, saa7110, adv7175, zr36060, zr36067 + +Inputs/outputs: Composite, S-video and Internal + +Norms: PAL, SECAM (768x576 @ 25 fps), NTSC (640x480 @ 29.97 fps) + +Card number: 2 + +Pinnacle/Miro DC10(old) +~~~~~~~~~~~~~~~~~~~~~~~ + +* Zoran zr36057 PCI controller +* Zoran zr36050 MJPEG codec +* Zoran zr36016 Video Front End or Fuji md0211 Video Front End (clone?) +* Micronas vpx3220a TV decoder +* mse3000 TV encoder or Analog Devices adv7176 TV encoder + +Drivers to use: videodev, i2c-core, i2c-algo-bit, +videocodec, vpx3220, mse3000/adv7175, zr36050, zr36016, zr36067 + +Inputs/outputs: Composite, S-video and Internal + +Norms: PAL, SECAM (768x576 @ 25 fps), NTSC (640x480 @ 29.97 fps) + +Card number: 0 + +Pinnacle/Miro DC30 +~~~~~~~~~~~~~~~~~~ + +* Zoran zr36057 PCI controller +* Zoran zr36050 MJPEG codec +* Zoran zr36016 Video Front End +* Micronas vpx3225d/vpx3220a/vpx3216b TV decoder +* Analog Devices adv7176 TV encoder + +Drivers to use: videodev, i2c-core, i2c-algo-bit, +videocodec, vpx3220/vpx3224, adv7175, zr36050, zr36016, zr36067 + +Inputs/outputs: Composite, S-video and Internal + +Norms: PAL, SECAM (768x576 @ 25 fps), NTSC (640x480 @ 29.97 fps) + +Card number: 3 + +Pinnacle/Miro DC30+ +~~~~~~~~~~~~~~~~~~~ + +* Zoran zr36067 PCI controller +* Zoran zr36050 MJPEG codec +* Zoran zr36016 Video Front End +* Micronas vpx3225d/vpx3220a/vpx3216b TV decoder +* Analog Devices adv7176 TV encoder + +Drivers to use: videodev, i2c-core, i2c-algo-bit, +videocodec, vpx3220/vpx3224, adv7175, zr36050, zr36015, zr36067 + +Inputs/outputs: Composite, S-video and Internal + +Norms: PAL, SECAM (768x576 @ 25 fps), NTSC (640x480 @ 29.97 fps) + +Card number: 4 + +.. note:: + + #) No module for the mse3000 is available yet + #) No module for the vpx3224 is available yet + +1.1 What the TV decoder can do an what not +------------------------------------------ + +The best know TV standards are NTSC/PAL/SECAM. but for decoding a frame that +information is not enough. There are several formats of the TV standards. +And not every TV decoder is able to handle every format. Also the every +combination is supported by the driver. There are currently 11 different +tv broadcast formats all aver the world. + +The CCIR defines parameters needed for broadcasting the signal. +The CCIR has defined different standards: A,B,D,E,F,G,D,H,I,K,K1,L,M,N,... +The CCIR says not much about the colorsystem used !!! +And talking about a colorsystem says not to much about how it is broadcast. + +The CCIR standards A,E,F are not used any more. + +When you speak about NTSC, you usually mean the standard: CCIR - M using +the NTSC colorsystem which is used in the USA, Japan, Mexico, Canada +and a few others. + +When you talk about PAL, you usually mean: CCIR - B/G using the PAL +colorsystem which is used in many Countries. + +When you talk about SECAM, you mean: CCIR - L using the SECAM Colorsystem +which is used in France, and a few others. + +There the other version of SECAM, CCIR - D/K is used in Bulgaria, China, +Slovakai, Hungary, Korea (Rep.), Poland, Rumania and a others. + +The CCIR - H uses the PAL colorsystem (sometimes SECAM) and is used in +Egypt, Libya, Sri Lanka, Syrain Arab. Rep. + +The CCIR - I uses the PAL colorsystem, and is used in Great Britain, Hong Kong, +Ireland, Nigeria, South Africa. + +The CCIR - N uses the PAL colorsystem and PAL frame size but the NTSC framerate, +and is used in Argentina, Uruguay, and a few others + +We do not talk about how the audio is broadcast ! + +A rather good sites about the TV standards are: +http://www.sony.jp/support/ +http://info.electronicwerkstatt.de/bereiche/fernsehtechnik/frequenzen_und_normen/Fernsehnormen/ +and http://www.cabl.com/restaurant/channel.html + +Other weird things around: NTSC 4.43 is a modificated NTSC, which is mainly +used in PAL VCR's that are able to play back NTSC. PAL 60 seems to be the same +as NTSC 4.43 . The Datasheets also talk about NTSC 44, It seems as if it would +be the same as NTSC 4.43. +NTSC Combs seems to be a decoder mode where the decoder uses a comb filter +to split coma and luma instead of a Delay line. + +But I did not defiantly find out what NTSC Comb is. + +Philips saa7111 TV decoder +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +- was introduced in 1997, is used in the BUZ and +- can handle: PAL B/G/H/I, PAL N, PAL M, NTSC M, NTSC N, NTSC 4.43 and SECAM + +Philips saa7110a TV decoder +~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +- was introduced in 1995, is used in the Pinnacle/Miro DC10(new), DC10+ and +- can handle: PAL B/G, NTSC M and SECAM + +Philips saa7114 TV decoder +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +- was introduced in 2000, is used in the LML33R10 and +- can handle: PAL B/G/D/H/I/N, PAL N, PAL M, NTSC M, NTSC 4.43 and SECAM + +Brooktree bt819 TV decoder +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +- was introduced in 1996, and is used in the LML33 and +- can handle: PAL B/D/G/H/I, NTSC M + +Micronas vpx3220a TV decoder +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +- was introduced in 1996, is used in the DC30 and DC30+ and +- can handle: PAL B/G/H/I, PAL N, PAL M, NTSC M, NTSC 44, PAL 60, SECAM,NTSC Comb + +Samsung ks0127 TV decoder +~~~~~~~~~~~~~~~~~~~~~~~~~ + +- is used in the AVS6EYES card and +- can handle: NTSC-M/N/44, PAL-M/N/B/G/H/I/D/K/L and SECAM + + +What the TV encoder can do an what not +-------------------------------------- + +The TV encoder is doing the "same" as the decoder, but in the other direction. +You feed them digital data and the generate a Composite or SVHS signal. +For information about the colorsystems and TV norm take a look in the +TV decoder section. + +Philips saa7185 TV Encoder +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +- was introduced in 1996, is used in the BUZ +- can generate: PAL B/G, NTSC M + +Brooktree bt856 TV Encoder +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +- was introduced in 1994, is used in the LML33 +- can generate: PAL B/D/G/H/I/N, PAL M, NTSC M, PAL-N (Argentina) + +Analog Devices adv7170 TV Encoder +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +- was introduced in 2000, is used in the LML300R10 +- can generate: PAL B/D/G/H/I/N, PAL M, NTSC M, PAL 60 + +Analog Devices adv7175 TV Encoder +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +- was introduced in 1996, is used in the DC10, DC10+, DC10 old, DC30, DC30+ +- can generate: PAL B/D/G/H/I/N, PAL M, NTSC M + +ITT mse3000 TV encoder +~~~~~~~~~~~~~~~~~~~~~~ + +- was introduced in 1991, is used in the DC10 old +- can generate: PAL , NTSC , SECAM + +Conexant bt866 TV encoder +~~~~~~~~~~~~~~~~~~~~~~~~~ + +- is used in AVS6EYES, and +- can generate: NTSC/PAL, PAL-M, PAL-N + +The adv717x, should be able to produce PAL N. But you find nothing PAL N +specific in the registers. Seem that you have to reuse a other standard +to generate PAL N, maybe it would work if you use the PAL M settings. + +How do I get this damn thing to work +------------------------------------ + +Load zr36067.o. If it can't autodetect your card, use the card=X insmod +option with X being the card number as given in the previous section. +To have more than one card, use card=X1[,X2[,X3,[X4[..]]]] + +To automate this, add the following to your /etc/modprobe.d/zoran.conf: + +options zr36067 card=X1[,X2[,X3[,X4[..]]]] +alias char-major-81-0 zr36067 + +One thing to keep in mind is that this doesn't load zr36067.o itself yet. It +just automates loading. If you start using xawtv, the device won't load on +some systems, since you're trying to load modules as a user, which is not +allowed ("permission denied"). A quick workaround is to add 'Load "v4l"' to +XF86Config-4 when you use X by default, or to run 'v4l-conf -c <device>' in +one of your startup scripts (normally rc.local) if you don't use X. Both +make sure that the modules are loaded on startup, under the root account. + +What mainboard should I use (or why doesn't my card work) +--------------------------------------------------------- + + +<insert lousy disclaimer here>. In short: good=SiS/Intel, bad=VIA. + +Experience tells us that people with a Buz, on average, have more problems +than users with a DC10+/LML33. Also, it tells us that people owning a VIA- +based mainboard (ktXXX, MVP3) have more problems than users with a mainboard +based on a different chipset. Here's some notes from Andrew Stevens: + +Here's my experience of using LML33 and Buz on various motherboards: + +- VIA MVP3 + - Forget it. Pointless. Doesn't work. +- Intel 430FX (Pentium 200) + - LML33 perfect, Buz tolerable (3 or 4 frames dropped per movie) +- Intel 440BX (early stepping) + - LML33 tolerable. Buz starting to get annoying (6-10 frames/hour) +- Intel 440BX (late stepping) + - Buz tolerable, LML3 almost perfect (occasional single frame drops) +- SiS735 + - LML33 perfect, Buz tolerable. +- VIA KT133(*) + - LML33 starting to get annoying, Buz poor enough that I have up. + +- Both 440BX boards were dual CPU versions. + +Bernhard Praschinger later added: + +- AMD 751 + - Buz perfect-tolerable +- AMD 760 + - Buz perfect-tolerable + +In general, people on the user mailinglist won't give you much of a chance +if you have a VIA-based motherboard. They may be cheap, but sometimes, you'd +rather want to spend some more money on better boards. In general, VIA +mainboard's IDE/PCI performance will also suck badly compared to others. +You'll noticed the DC10+/DC30+ aren't mentioned anywhere in the overview. +Basically, you can assume that if the Buz works, the LML33 will work too. If +the LML33 works, the DC10+/DC30+ will work too. They're most tolerant to +different mainboard chipsets from all of the supported cards. + +If you experience timeouts during capture, buy a better mainboard or lower +the quality/buffersize during capture (see 'Concerning buffer sizes, quality, +output size etc.'). If it hangs, there's little we can do as of now. Check +your IRQs and make sure the card has its own interrupts. + +Programming interface +--------------------- + +This driver conforms to video4linux2. Support for V4L1 and for the custom +zoran ioctls has been removed in kernel 2.6.38. + +For programming example, please, look at lavrec.c and lavplay.c code in +the MJPEG-tools (http://mjpeg.sf.net/). + +Additional notes for software developers: + + The driver returns maxwidth and maxheight parameters according to + the current TV standard (norm). Therefore, the software which + communicates with the driver and "asks" for these parameters should + first set the correct norm. Well, it seems logically correct: TV + standard is "more constant" for current country than geometry + settings of a variety of TV capture cards which may work in ITU or + square pixel format. + +Applications +------------ + +Applications known to work with this driver: + +TV viewing: + +* xawtv +* kwintv +* probably any TV application that supports video4linux or video4linux2. + +MJPEG capture/playback: + +* mjpegtools/lavtools (or Linux Video Studio) +* gstreamer +* mplayer + +General raw capture: + +* xawtv +* gstreamer +* probably any application that supports video4linux or video4linux2 + +Video editing: + +* Cinelerra +* MainActor +* mjpegtools (or Linux Video Studio) + + +Concerning buffer sizes, quality, output size etc. +-------------------------------------------------- + + +The zr36060 can do 1:2 JPEG compression. This is really the theoretical +maximum that the chipset can reach. The driver can, however, limit compression +to a maximum (size) of 1:4. The reason for this is that some cards (e.g. Buz) +can't handle 1:2 compression without stopping capture after only a few minutes. +With 1:4, it'll mostly work. If you have a Buz, use 'low_bitrate=1' to go into +1:4 max. compression mode. + +100% JPEG quality is thus 1:2 compression in practice. So for a full PAL frame +(size 720x576). The JPEG fields are stored in YUY2 format, so the size of the +fields are 720x288x16/2 bits/field (2 fields/frame) = 207360 bytes/field x 2 = +414720 bytes/frame (add some more bytes for headers and DHT (huffman)/DQT +(quantization) tables, and you'll get to something like 512kB per frame for +1:2 compression. For 1:4 compression, you'd have frames of half this size. + +Some additional explanation by Martin Samuelsson, which also explains the +importance of buffer sizes: +-- +> Hmm, I do not think it is really that way. With the current (downloaded +> at 18:00 Monday) driver I get that output sizes for 10 sec: +> -q 50 -b 128 : 24.283.332 Bytes +> -q 50 -b 256 : 48.442.368 +> -q 25 -b 128 : 24.655.992 +> -q 25 -b 256 : 25.859.820 + +I woke up, and can't go to sleep again. I'll kill some time explaining why +this doesn't look strange to me. + +Let's do some math using a width of 704 pixels. I'm not sure whether the Buz +actually use that number or not, but that's not too important right now. + +704x288 pixels, one field, is 202752 pixels. Divided by 64 pixels per block; +3168 blocks per field. Each pixel consist of two bytes; 128 bytes per block; +1024 bits per block. 100% in the new driver mean 1:2 compression; the maximum +output becomes 512 bits per block. Actually 510, but 512 is simpler to use +for calculations. + +Let's say that we specify d1q50. We thus want 256 bits per block; times 3168 +becomes 811008 bits; 101376 bytes per field. We're talking raw bits and bytes +here, so we don't need to do any fancy corrections for bits-per-pixel or such +things. 101376 bytes per field. + +d1 video contains two fields per frame. Those sum up to 202752 bytes per +frame, and one of those frames goes into each buffer. + +But wait a second! -b128 gives 128kB buffers! It's not possible to cram +202752 bytes of JPEG data into 128kB! + +This is what the driver notice and automatically compensate for in your +examples. Let's do some math using this information: + +128kB is 131072 bytes. In this buffer, we want to store two fields, which +leaves 65536 bytes for each field. Using 3168 blocks per field, we get +20.68686868... available bytes per block; 165 bits. We can't allow the +request for 256 bits per block when there's only 165 bits available! The -q50 +option is silently overridden, and the -b128 option takes precedence, leaving +us with the equivalence of -q32. + +This gives us a data rate of 165 bits per block, which, times 3168, sums up +to 65340 bytes per field, out of the allowed 65536. The current driver has +another level of rate limiting; it won't accept -q values that fill more than +6/8 of the specified buffers. (I'm not sure why. "Playing it safe" seem to be +a safe bet. Personally, I think I would have lowered requested-bits-per-block +by one, or something like that.) We can't use 165 bits per block, but have to +lower it again, to 6/8 of the available buffer space: We end up with 124 bits +per block, the equivalence of -q24. With 128kB buffers, you can't use greater +than -q24 at -d1. (And PAL, and 704 pixels width...) + +The third example is limited to -q24 through the same process. The second +example, using very similar calculations, is limited to -q48. The only +example that actually grab at the specified -q value is the last one, which +is clearly visible, looking at the file size. +-- + +Conclusion: the quality of the resulting movie depends on buffer size, quality, +whether or not you use 'low_bitrate=1' as insmod option for the zr36060.c +module to do 1:4 instead of 1:2 compression, etc. + +If you experience timeouts, lowering the quality/buffersize or using +'low_bitrate=1 as insmod option for zr36060.o might actually help, as is +proven by the Buz. + +It hangs/crashes/fails/whatevers! Help! +--------------------------------------- + +Make sure that the card has its own interrupts (see /proc/interrupts), check +the output of dmesg at high verbosity (load zr36067.o with debug=2, +load all other modules with debug=1). Check that your mainboard is favorable +(see question 2) and if not, test the card in another computer. Also see the +notes given in question 3 and try lowering quality/buffersize/capturesize +if recording fails after a period of time. + +If all this doesn't help, give a clear description of the problem including +detailed hardware information (memory+brand, mainboard+chipset+brand, which +MJPEG card, processor, other PCI cards that might be of interest), give the +system PnP information (/proc/interrupts, /proc/dma, /proc/devices), and give +the kernel version, driver version, glibc version, gcc version and any other +information that might possibly be of interest. Also provide the dmesg output +at high verbosity. See 'Contacting' on how to contact the developers. + +Maintainers/Contacting +---------------------- + +Previous maintainers/developers of this driver are +- Laurent Pinchart <laurent.pinchart@skynet.be> +- Ronald Bultje rbultje@ronald.bitfreak.net +- Serguei Miridonov <mirsev@cicese.mx> +- Wolfgang Scherr <scherr@net4you.net> +- Dave Perks <dperks@ibm.net> +- Rainer Johanni <Rainer@Johanni.de> + +Driver's License +---------------- + + This driver is distributed under the terms of the General Public License. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + +See http://www.gnu.org/ for more information. diff --git a/Documentation/driver-api/media/dtv-ca.rst b/Documentation/driver-api/media/dtv-ca.rst new file mode 100644 index 000000000..8a09862b4 --- /dev/null +++ b/Documentation/driver-api/media/dtv-ca.rst @@ -0,0 +1,6 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Digital TV Conditional Access kABI +---------------------------------- + +.. kernel-doc:: include/media/dvb_ca_en50221.h diff --git a/Documentation/driver-api/media/dtv-common.rst b/Documentation/driver-api/media/dtv-common.rst new file mode 100644 index 000000000..207a22bca --- /dev/null +++ b/Documentation/driver-api/media/dtv-common.rst @@ -0,0 +1,53 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Digital TV Common functions +--------------------------- + +DVB devices +~~~~~~~~~~~ + +Those functions are responsible for handling the DVB device nodes. + +.. kernel-doc:: include/media/dvbdev.h + +Digital TV Ring buffer +~~~~~~~~~~~~~~~~~~~~~~ + +Those routines implement ring buffers used to handle digital TV data and +copy it from/to userspace. + +.. note:: + + 1) For performance reasons read and write routines don't check buffer sizes + and/or number of bytes free/available. This has to be done before these + routines are called. For example: + + .. code-block:: c + + /* write @buflen: bytes */ + free = dvb_ringbuffer_free(rbuf); + if (free >= buflen) + count = dvb_ringbuffer_write(rbuf, buffer, buflen); + else + /* do something */ + + /* read min. 1000, max. @bufsize: bytes */ + avail = dvb_ringbuffer_avail(rbuf); + if (avail >= 1000) + count = dvb_ringbuffer_read(rbuf, buffer, min(avail, bufsize)); + else + /* do something */ + + 2) If there is exactly one reader and one writer, there is no need + to lock read or write operations. + Two or more readers must be locked against each other. + Flushing the buffer counts as a read operation. + Resetting the buffer counts as a read and write operation. + Two or more writers must be locked against each other. + +.. kernel-doc:: include/media/dvb_ringbuffer.h + +Digital TV VB2 handler +~~~~~~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: include/media/dvb_vb2.h diff --git a/Documentation/driver-api/media/dtv-core.rst b/Documentation/driver-api/media/dtv-core.rst new file mode 100644 index 000000000..82c5b85ed --- /dev/null +++ b/Documentation/driver-api/media/dtv-core.rst @@ -0,0 +1,39 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Digital TV (DVB) devices +------------------------ + +Digital TV devices are implemented by several different drivers: + +- A bridge driver that is responsible to talk with the bus where the other + devices are connected (PCI, USB, SPI), bind to the other drivers and + implement the digital demux logic (either in software or in hardware); + +- Frontend drivers that are usually implemented as two separate drivers: + + - A tuner driver that implements the logic which commands the part of + the hardware responsible for tuning into a digital TV transponder or + physical channel. The output of a tuner is usually a baseband or + Intermediate Frequency (IF) signal; + + - A demodulator driver (a.k.a "demod") that implements the logic which + commands the digital TV decoding hardware. The output of a demod is + a digital stream, with multiple audio, video and data channels typically + multiplexed using MPEG Transport Stream [#f1]_. + +On most hardware, the frontend drivers talk with the bridge driver using an +I2C bus. + +.. [#f1] Some standards use TCP/IP for multiplexing data, like DVB-H (an + abandoned standard, not used anymore) and ATSC version 3.0 current + proposals. Currently, the DVB subsystem doesn't implement those standards. + + +.. toctree:: + :maxdepth: 1 + + dtv-common + dtv-frontend + dtv-demux + dtv-ca + dtv-net diff --git a/Documentation/driver-api/media/dtv-demux.rst b/Documentation/driver-api/media/dtv-demux.rst new file mode 100644 index 000000000..144124142 --- /dev/null +++ b/Documentation/driver-api/media/dtv-demux.rst @@ -0,0 +1,84 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Digital TV Demux kABI +--------------------- + +Digital TV Demux +~~~~~~~~~~~~~~~~ + +The Kernel Digital TV Demux kABI defines a driver-internal interface for +registering low-level, hardware specific driver to a hardware independent +demux layer. It is only of interest for Digital TV device driver writers. +The header file for this kABI is named ``demux.h`` and located in +``include/media``. + +The demux kABI should be implemented for each demux in the system. It is +used to select the TS source of a demux and to manage the demux resources. +When the demux client allocates a resource via the demux kABI, it receives +a pointer to the kABI of that resource. + +Each demux receives its TS input from a DVB front-end or from memory, as +set via this demux kABI. In a system with more than one front-end, the kABI +can be used to select one of the DVB front-ends as a TS source for a demux, +unless this is fixed in the HW platform. + +The demux kABI only controls front-ends regarding to their connections with +demuxes; the kABI used to set the other front-end parameters, such as +tuning, are defined via the Digital TV Frontend kABI. + +The functions that implement the abstract interface demux should be defined +static or module private and registered to the Demux core for external +access. It is not necessary to implement every function in the struct +:c:type:`dmx_demux`. For example, a demux interface might support Section filtering, +but not PES filtering. The kABI client is expected to check the value of any +function pointer before calling the function: the value of ``NULL`` means +that the function is not available. + +Whenever the functions of the demux API modify shared data, the +possibilities of lost update and race condition problems should be +addressed, e.g. by protecting parts of code with mutexes. + +Note that functions called from a bottom half context must not sleep. +Even a simple memory allocation without using ``GFP_ATOMIC`` can result in a +kernel thread being put to sleep if swapping is needed. For example, the +Linux Kernel calls the functions of a network device interface from a +bottom half context. Thus, if a demux kABI function is called from network +device code, the function must not sleep. + +Demux Callback API +~~~~~~~~~~~~~~~~~~ + +This kernel-space API comprises the callback functions that deliver filtered +data to the demux client. Unlike the other DVB kABIs, these functions are +provided by the client and called from the demux code. + +The function pointers of this abstract interface are not packed into a +structure as in the other demux APIs, because the callback functions are +registered and used independent of each other. As an example, it is possible +for the API client to provide several callback functions for receiving TS +packets and no callbacks for PES packets or sections. + +The functions that implement the callback API need not be re-entrant: when +a demux driver calls one of these functions, the driver is not allowed to +call the function again before the original call returns. If a callback is +triggered by a hardware interrupt, it is recommended to use the Linux +bottom half mechanism or start a tasklet instead of making the callback +function call directly from a hardware interrupt. + +This mechanism is implemented by :c:func:`dmx_ts_cb()` and :c:func:`dmx_section_cb()` +callbacks. + +Digital TV Demux device registration functions and data structures +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: include/media/dmxdev.h + +High-level Digital TV demux interface +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: include/media/dvb_demux.h + +Driver-internal low-level hardware specific driver demux interface +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: include/media/demux.h diff --git a/Documentation/driver-api/media/dtv-frontend.rst b/Documentation/driver-api/media/dtv-frontend.rst new file mode 100644 index 000000000..ea43cdb5b --- /dev/null +++ b/Documentation/driver-api/media/dtv-frontend.rst @@ -0,0 +1,445 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Digital TV Frontend kABI +------------------------ + +Digital TV Frontend +~~~~~~~~~~~~~~~~~~~ + +The Digital TV Frontend kABI defines a driver-internal interface for +registering low-level, hardware specific driver to a hardware independent +frontend layer. It is only of interest for Digital TV device driver writers. +The header file for this API is named ``dvb_frontend.h`` and located in +``include/media/``. + +Demodulator driver +^^^^^^^^^^^^^^^^^^ + +The demodulator driver is responsible for talking with the decoding part of the +hardware. Such driver should implement :c:type:`dvb_frontend_ops`, which +tells what type of digital TV standards are supported, and points to a +series of functions that allow the DVB core to command the hardware via +the code under ``include/media/dvb_frontend.c``. + +A typical example of such struct in a driver ``foo`` is:: + + static struct dvb_frontend_ops foo_ops = { + .delsys = { SYS_DVBT, SYS_DVBT2, SYS_DVBC_ANNEX_A }, + .info = { + .name = "foo DVB-T/T2/C driver", + .caps = FE_CAN_FEC_1_2 | + FE_CAN_FEC_2_3 | + FE_CAN_FEC_3_4 | + FE_CAN_FEC_5_6 | + FE_CAN_FEC_7_8 | + FE_CAN_FEC_AUTO | + FE_CAN_QPSK | + FE_CAN_QAM_16 | + FE_CAN_QAM_32 | + FE_CAN_QAM_64 | + FE_CAN_QAM_128 | + FE_CAN_QAM_256 | + FE_CAN_QAM_AUTO | + FE_CAN_TRANSMISSION_MODE_AUTO | + FE_CAN_GUARD_INTERVAL_AUTO | + FE_CAN_HIERARCHY_AUTO | + FE_CAN_MUTE_TS | + FE_CAN_2G_MODULATION, + .frequency_min = 42000000, /* Hz */ + .frequency_max = 1002000000, /* Hz */ + .symbol_rate_min = 870000, + .symbol_rate_max = 11700000 + }, + .init = foo_init, + .sleep = foo_sleep, + .release = foo_release, + .set_frontend = foo_set_frontend, + .get_frontend = foo_get_frontend, + .read_status = foo_get_status_and_stats, + .tune = foo_tune, + .i2c_gate_ctrl = foo_i2c_gate_ctrl, + .get_frontend_algo = foo_get_algo, + }; + +A typical example of such struct in a driver ``bar`` meant to be used on +Satellite TV reception is:: + + static const struct dvb_frontend_ops bar_ops = { + .delsys = { SYS_DVBS, SYS_DVBS2 }, + .info = { + .name = "Bar DVB-S/S2 demodulator", + .frequency_min = 500000, /* KHz */ + .frequency_max = 2500000, /* KHz */ + .frequency_stepsize = 0, + .symbol_rate_min = 1000000, + .symbol_rate_max = 45000000, + .symbol_rate_tolerance = 500, + .caps = FE_CAN_INVERSION_AUTO | + FE_CAN_FEC_AUTO | + FE_CAN_QPSK, + }, + .init = bar_init, + .sleep = bar_sleep, + .release = bar_release, + .set_frontend = bar_set_frontend, + .get_frontend = bar_get_frontend, + .read_status = bar_get_status_and_stats, + .i2c_gate_ctrl = bar_i2c_gate_ctrl, + .get_frontend_algo = bar_get_algo, + .tune = bar_tune, + + /* Satellite-specific */ + .diseqc_send_master_cmd = bar_send_diseqc_msg, + .diseqc_send_burst = bar_send_burst, + .set_tone = bar_set_tone, + .set_voltage = bar_set_voltage, + }; + +.. note:: + + #) For satellite digital TV standards (DVB-S, DVB-S2, ISDB-S), the + frequencies are specified in kHz, while, for terrestrial and cable + standards, they're specified in Hz. Due to that, if the same frontend + supports both types, you'll need to have two separate + :c:type:`dvb_frontend_ops` structures, one for each standard. + #) The ``.i2c_gate_ctrl`` field is present only when the hardware has + allows controlling an I2C gate (either directly of via some GPIO pin), + in order to remove the tuner from the I2C bus after a channel is + tuned. + #) All new drivers should implement the + :ref:`DVBv5 statistics <dvbv5_stats>` via ``.read_status``. + Yet, there are a number of callbacks meant to get statistics for + signal strength, S/N and UCB. Those are there to provide backward + compatibility with legacy applications that don't support the DVBv5 + API. Implementing those callbacks are optional. Those callbacks may be + removed in the future, after we have all existing drivers supporting + DVBv5 stats. + #) Other callbacks are required for satellite TV standards, in order to + control LNBf and DiSEqC: ``.diseqc_send_master_cmd``, + ``.diseqc_send_burst``, ``.set_tone``, ``.set_voltage``. + +.. |delta| unicode:: U+00394 + +The ``include/media/dvb_frontend.c`` has a kernel thread which is +responsible for tuning the device. It supports multiple algorithms to +detect a channel, as defined at enum :c:func:`dvbfe_algo`. + +The algorithm to be used is obtained via ``.get_frontend_algo``. If the driver +doesn't fill its field at struct dvb_frontend_ops, it will default to +``DVBFE_ALGO_SW``, meaning that the dvb-core will do a zigzag when tuning, +e. g. it will try first to use the specified center frequency ``f``, +then, it will do ``f`` + |delta|, ``f`` - |delta|, ``f`` + 2 x |delta|, +``f`` - 2 x |delta| and so on. + +If the hardware has internally a some sort of zigzag algorithm, you should +define a ``.get_frontend_algo`` function that would return ``DVBFE_ALGO_HW``. + +.. note:: + + The core frontend support also supports + a third type (``DVBFE_ALGO_CUSTOM``), in order to allow the driver to + define its own hardware-assisted algorithm. Very few hardware need to + use it nowadays. Using ``DVBFE_ALGO_CUSTOM`` require to provide other + function callbacks at struct dvb_frontend_ops. + +Attaching frontend driver to the bridge driver +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Before using the Digital TV frontend core, the bridge driver should attach +the frontend demod, tuner and SEC devices and call +:c:func:`dvb_register_frontend()`, +in order to register the new frontend at the subsystem. At device +detach/removal, the bridge driver should call +:c:func:`dvb_unregister_frontend()` to +remove the frontend from the core and then :c:func:`dvb_frontend_detach()` +to free the memory allocated by the frontend drivers. + +The drivers should also call :c:func:`dvb_frontend_suspend()` as part of +their handler for the :c:type:`device_driver`.\ ``suspend()``, and +:c:func:`dvb_frontend_resume()` as +part of their handler for :c:type:`device_driver`.\ ``resume()``. + +A few other optional functions are provided to handle some special cases. + +.. _dvbv5_stats: + +Digital TV Frontend statistics +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Introduction +^^^^^^^^^^^^ + +Digital TV frontends provide a range of +:ref:`statistics <frontend-stat-properties>` meant to help tuning the device +and measuring the quality of service. + +For each statistics measurement, the driver should set the type of scale used, +or ``FE_SCALE_NOT_AVAILABLE`` if the statistics is not available on a given +time. Drivers should also provide the number of statistics for each type. +that's usually 1 for most video standards [#f2]_. + +Drivers should initialize each statistic counters with length and +scale at its init code. For example, if the frontend provides signal +strength, it should have, on its init code:: + + struct dtv_frontend_properties *c = &state->fe.dtv_property_cache; + + c->strength.len = 1; + c->strength.stat[0].scale = FE_SCALE_NOT_AVAILABLE; + +And, when the statistics got updated, set the scale:: + + c->strength.stat[0].scale = FE_SCALE_DECIBEL; + c->strength.stat[0].uvalue = strength; + +.. [#f2] For ISDB-T, it may provide both a global statistics and a per-layer + set of statistics. On such cases, len should be equal to 4. The first + value corresponds to the global stat; the other ones to each layer, e. g.: + + - c->cnr.stat[0] for global S/N carrier ratio, + - c->cnr.stat[1] for Layer A S/N carrier ratio, + - c->cnr.stat[2] for layer B S/N carrier ratio, + - c->cnr.stat[3] for layer C S/N carrier ratio. + +.. note:: Please prefer to use ``FE_SCALE_DECIBEL`` instead of + ``FE_SCALE_RELATIVE`` for signal strength and CNR measurements. + +Groups of statistics +^^^^^^^^^^^^^^^^^^^^ + +There are several groups of statistics currently supported: + +Signal strength (:ref:`DTV-STAT-SIGNAL-STRENGTH`) + - Measures the signal strength level at the analog part of the tuner or + demod. + + - Typically obtained from the gain applied to the tuner and/or frontend + in order to detect the carrier. When no carrier is detected, the gain is + at the maximum value (so, strength is on its minimal). + + - As the gain is visible through the set of registers that adjust the gain, + typically, this statistics is always available [#f3]_. + + - Drivers should try to make it available all the times, as these statistics + can be used when adjusting an antenna position and to check for troubles + at the cabling. + + .. [#f3] On a few devices, the gain keeps floating if there is no carrier. + On such devices, strength report should check first if carrier is + detected at the tuner (``FE_HAS_CARRIER``, see :c:type:`fe_status`), + and otherwise return the lowest possible value. + +Carrier Signal to Noise ratio (:ref:`DTV-STAT-CNR`) + - Signal to Noise ratio for the main carrier. + + - Signal to Noise measurement depends on the device. On some hardware, it is + available when the main carrier is detected. On those hardware, CNR + measurement usually comes from the tuner (e. g. after ``FE_HAS_CARRIER``, + see :c:type:`fe_status`). + + On other devices, it requires inner FEC decoding, + as the frontend measures it indirectly from other parameters (e. g. after + ``FE_HAS_VITERBI``, see :c:type:`fe_status`). + + Having it available after inner FEC is more common. + +Bit counts post-FEC (:ref:`DTV-STAT-POST-ERROR-BIT-COUNT` and :ref:`DTV-STAT-POST-TOTAL-BIT-COUNT`) + - Those counters measure the number of bits and bit errors after + the forward error correction (FEC) on the inner coding block + (after Viterbi, LDPC or other inner code). + + - Due to its nature, those statistics depend on full coding lock + (e. g. after ``FE_HAS_SYNC`` or after ``FE_HAS_LOCK``, + see :c:type:`fe_status`). + +Bit counts pre-FEC (:ref:`DTV-STAT-PRE-ERROR-BIT-COUNT` and :ref:`DTV-STAT-PRE-TOTAL-BIT-COUNT`) + - Those counters measure the number of bits and bit errors before + the forward error correction (FEC) on the inner coding block + (before Viterbi, LDPC or other inner code). + + - Not all frontends provide this kind of statistics. + + - Due to its nature, those statistics depend on inner coding lock (e. g. + after ``FE_HAS_VITERBI``, see :c:type:`fe_status`). + +Block counts (:ref:`DTV-STAT-ERROR-BLOCK-COUNT` and :ref:`DTV-STAT-TOTAL-BLOCK-COUNT`) + - Those counters measure the number of blocks and block errors after + the forward error correction (FEC) on the inner coding block + (before Viterbi, LDPC or other inner code). + + - Due to its nature, those statistics depend on full coding lock + (e. g. after ``FE_HAS_SYNC`` or after + ``FE_HAS_LOCK``, see :c:type:`fe_status`). + +.. note:: All counters should be monotonically increased as they're + collected from the hardware. + +A typical example of the logic that handle status and statistics is:: + + static int foo_get_status_and_stats(struct dvb_frontend *fe) + { + struct foo_state *state = fe->demodulator_priv; + struct dtv_frontend_properties *c = &fe->dtv_property_cache; + + int rc; + enum fe_status *status; + + /* Both status and strength are always available */ + rc = foo_read_status(fe, &status); + if (rc < 0) + return rc; + + rc = foo_read_strength(fe); + if (rc < 0) + return rc; + + /* Check if CNR is available */ + if (!(fe->status & FE_HAS_CARRIER)) + return 0; + + rc = foo_read_cnr(fe); + if (rc < 0) + return rc; + + /* Check if pre-BER stats are available */ + if (!(fe->status & FE_HAS_VITERBI)) + return 0; + + rc = foo_get_pre_ber(fe); + if (rc < 0) + return rc; + + /* Check if post-BER stats are available */ + if (!(fe->status & FE_HAS_SYNC)) + return 0; + + rc = foo_get_post_ber(fe); + if (rc < 0) + return rc; + } + + static const struct dvb_frontend_ops ops = { + /* ... */ + .read_status = foo_get_status_and_stats, + }; + +Statistics collection +^^^^^^^^^^^^^^^^^^^^^ + +On almost all frontend hardware, the bit and byte counts are stored by +the hardware after a certain amount of time or after the total bit/block +counter reaches a certain value (usually programmable), for example, on +every 1000 ms or after receiving 1,000,000 bits. + +So, if you read the registers too soon, you'll end by reading the same +value as in the previous reading, causing the monotonic value to be +incremented too often. + +Drivers should take the responsibility to avoid too often reads. That +can be done using two approaches: + +if the driver have a bit that indicates when a collected data is ready +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +Driver should check such bit before making the statistics available. + +An example of such behavior can be found at this code snippet (adapted +from mb86a20s driver's logic):: + + static int foo_get_pre_ber(struct dvb_frontend *fe) + { + struct foo_state *state = fe->demodulator_priv; + struct dtv_frontend_properties *c = &fe->dtv_property_cache; + int rc, bit_error; + + /* Check if the BER measures are already available */ + rc = foo_read_u8(state, 0x54); + if (rc < 0) + return rc; + + if (!rc) + return 0; + + /* Read Bit Error Count */ + bit_error = foo_read_u32(state, 0x55); + if (bit_error < 0) + return bit_error; + + /* Read Total Bit Count */ + rc = foo_read_u32(state, 0x51); + if (rc < 0) + return rc; + + c->pre_bit_error.stat[0].scale = FE_SCALE_COUNTER; + c->pre_bit_error.stat[0].uvalue += bit_error; + c->pre_bit_count.stat[0].scale = FE_SCALE_COUNTER; + c->pre_bit_count.stat[0].uvalue += rc; + + return 0; + } + +If the driver doesn't provide a statistics available check bit +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +A few devices, however, may not provide a way to check if the stats are +available (or the way to check it is unknown). They may not even provide +a way to directly read the total number of bits or blocks. + +On those devices, the driver need to ensure that it won't be reading from +the register too often and/or estimate the total number of bits/blocks. + +On such drivers, a typical routine to get statistics would be like +(adapted from dib8000 driver's logic):: + + struct foo_state { + /* ... */ + + unsigned long per_jiffies_stats; + } + + static int foo_get_pre_ber(struct dvb_frontend *fe) + { + struct foo_state *state = fe->demodulator_priv; + struct dtv_frontend_properties *c = &fe->dtv_property_cache; + int rc, bit_error; + u64 bits; + + /* Check if time for stats was elapsed */ + if (!time_after(jiffies, state->per_jiffies_stats)) + return 0; + + /* Next stat should be collected in 1000 ms */ + state->per_jiffies_stats = jiffies + msecs_to_jiffies(1000); + + /* Read Bit Error Count */ + bit_error = foo_read_u32(state, 0x55); + if (bit_error < 0) + return bit_error; + + /* + * On this particular frontend, there's no register that + * would provide the number of bits per 1000ms sample. So, + * some function would calculate it based on DTV properties + */ + bits = get_number_of_bits_per_1000ms(fe); + + c->pre_bit_error.stat[0].scale = FE_SCALE_COUNTER; + c->pre_bit_error.stat[0].uvalue += bit_error; + c->pre_bit_count.stat[0].scale = FE_SCALE_COUNTER; + c->pre_bit_count.stat[0].uvalue += bits; + + return 0; + } + +Please notice that, on both cases, we're getting the statistics using the +:c:type:`dvb_frontend_ops` ``.read_status`` callback. The rationale is that +the frontend core will automatically call this function periodically +(usually, 3 times per second, when the frontend is locked). + +That warrants that we won't miss to collect a counter and increment the +monotonic stats at the right time. + +Digital TV Frontend functions and types +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: include/media/dvb_frontend.h diff --git a/Documentation/driver-api/media/dtv-net.rst b/Documentation/driver-api/media/dtv-net.rst new file mode 100644 index 000000000..deb6bffe9 --- /dev/null +++ b/Documentation/driver-api/media/dtv-net.rst @@ -0,0 +1,6 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Digital TV Network kABI +----------------------- + +.. kernel-doc:: include/media/dvb_net.h diff --git a/Documentation/driver-api/media/index.rst b/Documentation/driver-api/media/index.rst new file mode 100644 index 000000000..08fc2cfc0 --- /dev/null +++ b/Documentation/driver-api/media/index.rst @@ -0,0 +1,55 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. include:: <isonum.txt> + +=================================== +Media subsystem kernel internal API +=================================== + +This section contains usage information about media subsystem and +its supported drivers. + +Please see: + +Documentation/admin-guide/media/index.rst + + - for usage information about media subsystem and supported drivers; + +Documentation/userspace-api/media/index.rst + + - for the userspace APIs used on media devices. + + +.. toctree:: + :caption: Table of Contents + :maxdepth: 5 + :numbered: + + maintainer-entry-profile + media-committers + + v4l2-core + dtv-core + rc-core + mc-core + cec-core + tx-rx + camera-sensor + + drivers/index + +**Copyright** |copy| 2009-2020 : LinuxTV Developers + +:: + + This documentation is free software; you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by the Free + Software Foundation; either version 2 of the License, or (at your option) any + later version. + + This program is distributed in the hope that it will be useful, but WITHOUT + ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + more details. + + For more details see the file COPYING in the source distribution of Linux. diff --git a/Documentation/driver-api/media/maintainer-entry-profile.rst b/Documentation/driver-api/media/maintainer-entry-profile.rst new file mode 100644 index 000000000..7806d8312 --- /dev/null +++ b/Documentation/driver-api/media/maintainer-entry-profile.rst @@ -0,0 +1,549 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Media Subsystem Profile +======================= + +Overview +-------- + +The Linux Media Community (aka: the LinuxTV Community) is formed by +developers working on Linux Kernel Media Subsystem, together with users +who also play an important role in testing the code. + +The Media Subsystem has code to support a wide variety of media-related +devices: stream capture, analog and digital TV streams, cameras, +video codecs, video processing (resizers, etc.), radio, remote controllers, +HDMI CEC and media pipeline control. + +The Media Subsystem consists of the following directories in the kernel +tree: + + - drivers/media + - drivers/staging/media + - include/media + - Documentation/devicetree/bindings/media/\ [1]_ + - Documentation/admin-guide/media + - Documentation/driver-api/media + - Documentation/userspace-api/media + +.. [1] Device tree bindings are maintained by the + OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS maintainers + (see the MAINTAINERS file). So, changes there must be reviewed + by them before being merged into the media subsystem's development + tree. + +Both media userspace and Kernel APIs are documented and the documentation +must be kept in sync with the API changes. It means that all patches that +add new features to the subsystem must also bring changes to the +corresponding API documentation. + +Media Maintainers +----------------- + +Media Maintainers are not just people capable of writing code, but they +are developers who have demonstrated their ability to collaborate with +the team, get the most knowledgeable people to review code, contribute +high-quality code, and follow through to fix issues (in code or tests). + +Due to the size and wide scope of the media subsystem, multiple layers of +maintainers are required, each with their own areas of expertise: + +- **Media Driver Maintainer**: + Responsible for one or more drivers within the Media Subsystem. They + are listed in the MAINTAINERS file as maintainer for those drivers. Media + Driver Maintainers review patches for those drivers, provide feedback if + patches do not follow the subsystem rules, or are not using the + media kernel or userspace APIs correctly, or if they have poor code + quality. + + If you are the patch author, you work with other Media + Maintainers to ensure your patches are reviewed. + + Some Media Driver Maintainers have additional responsibilities. They have + been granted Patchwork access and keep + `Patchwork <https://patchwork.linuxtv.org/project/linux-media/list/>`_ + up to date, decide when patches are ready for merging, and create Pull + Requests for the Media Subsystem Maintainers to merge. + +- **Media Core Maintainer**: + Media Driver Maintainers with Patchwork access who are also responsible for + one or more media core frameworks. + + Core framework changes are done via consensus between the relevant Media + Core Maintainers. Media Maintainers may include core framework changes in + their Pull Requests if they are signed off by the relevant Media Core + Maintainers. + +- **Media Subsystem Maintainers**: + Media Core Maintainers who are also responsible for the subsystem as a + whole, with access to the entire subsystem. Responsible for merging Pull + Requests from other Media Maintainers. + + Userspace API/ABI changes are made via consensus among Media Subsystem + Maintainers\ [2]_. Media Maintainers may include API/ABI changes in + their Pull Requests if they are signed off by all Media Subsystem + Maintainers. + +All Media Maintainers shall agree with the Kernel development process as +described in Documentation/process/index.rst and with the Kernel development +rules in the Kernel documentation, including its code of conduct. + +Media Maintainers are often reachable via the #linux-media IRC channel at OFTC. + +.. [2] Everything that would break backward compatibility with existing + non-kernel code are API/ABI changes. This includes ioctl and sysfs + interfaces, v4l2 controls, and their behaviors. + +Patchwork Access +---------------- + +All Media Maintainers who have been granted Patchwork access shall ensure that +`Patchwork <https://patchwork.linuxtv.org/project/linux-media/list/>`_ +will reflect the current status, e.g. patches shall be delegated to the Media +Maintainer who is handling them and the patch status shall be updated according +to these rules: + +- ``Under Review``: Used if the patch requires a second opinion + or when it is part of a Pull Request; +- ``Superseded``: There is a newer version of the patch posted to the + mailing list. +- ``Duplicated``: There was another patch doing the same thing from someone + else that was accepted. +- ``Not Applicable``: Use for patch series that are not merged at media.git + tree (e.g. drm, dmabuf, upstream merge, etc.) but were cross-posted to the + linux-media mailing list. +- ``Accepted``: Once a patch is merged in the multi-committer tree. Only Media + Maintainers with commit rights are allowed to set this state. + +If Media Maintainers decide not to accept a patch, they should reply to the +patch authors by e‑mail, explaining why it is not accepted, and +update `Patchwork <https://patchwork.linuxtv.org/project/linux-media/list/>`_ +accordingly with one of the following statuses: + +- ``Changes Requested``: if a new revision was requested; +- ``Rejected``: if the proposed change is not acceptable at all. + +.. Note:: + + Patchwork supports a couple of clients to help semi-automate + status updates via its REST interface: + + https://patchwork.readthedocs.io/en/latest/usage/clients/ + +For patches that fall within their area of responsibility a Media Maintainer +also decides when those patches are ready for merging, and create Pull Requests +for the Media Subsystem Maintainers to merge. + +The most important aspect of becoming a Media Maintainer with Patchwork access +is that you have demonstrated an ability to give good code reviews. We value +your ability to deliver thorough, constructive code reviews. + +As such, potential maintainers must earn enough credibility and trust from the +Linux Media Community. To do that, developers shall be familiar with the open +source model and have been active in the Linux Kernel community for some time, +and, in particular, in the media subsystem. + +In addition to actually making the code changes, you are basically +demonstrating your: + +- commitment to the project; +- ability to collaborate with the team and communicate well; +- understanding of how upstream and the Linux Media Community work + (policies, processes for testing, code review, ...) +- reasonable knowledge about: + + - the Kernel development process: + Documentation/process/index.rst + + - the Media development profile: + Documentation/driver-api/media/maintainer-entry-profile.rst + +- understanding of the projects' code base and coding style; +- ability to provide feedback to the patch authors; +- ability to judge when a patch might be ready for review and to submit; +- ability to write good code (last but certainly not least). + +Media Driver Maintainers that desire to get Patchwork access are encouraged +to participate at the yearly Linux Media Summit, typically co-located with +a Linux-related conference. These summits are announced on the linux-media +mailing list. + +If you are doing such tasks and have become a valued developer, an +existing Media Maintainer can nominate you to the Media Subsystem Maintainers. + +The ultimate responsibility for accepting a nominated maintainer is up to +the subsystem's maintainers. The nominated maintainer must have earned a trust +relationship with all Media Subsystem Maintainers, as, by being granted +Patchwork access, you will take over part of their maintenance tasks. + +Media Committers +---------------- + +Experienced and trusted Media Maintainers may be granted commit rights +which allow them to directly push patches to the media development tree instead +of posting a Pull Request for the Media Subsystem Maintainers. This helps +offloading some of the work of the Media Subsystem Maintainers. + +More details about Media Committers' roles and responsibilities can be +found here: :ref:`Media Committers`. + +Media development sites +----------------------- + +The `LinuxTV <https://linuxtv.org/>`_ web site hosts news about the subsystem, +together with: + +- `Wiki pages <https://www.linuxtv.org/wiki/index.php/Main_Page>`_; +- `Patchwork <https://patchwork.linuxtv.org/project/linux-media/list/>`_; +- `Linux Media documentation <https://linuxtv.org/docs.php>`_; +- and more. + +The main development trees used by the media subsystem are at: + +- Stable tree: + - https://git.linuxtv.org/media.git/ + +- Media committers tree: + - https://gitlab.freedesktop.org/linux-media/media-committers.git + + Please note that it can be rebased, although only as a last resort. + +- Media development trees, including apps and CI: + + - https://git.linuxtv.org/ + - https://gitlab.freedesktop.org/linux-media/ + + +.. _Media development workflow: + +Media development workflow +++++++++++++++++++++++++++ + +All changes for the media subsystem shall be sent first as e-mails to the +media mailing list, following the process documented at +Documentation/process/index.rst. + +It means that patches shall be submitted as plain text only via e-mail to +linux-media@vger.kernel.org (aka: LMML). While subscription is not mandatory, +you can find details about how to subscribe to it and to see its archives at: + + https://subspace.kernel.org/vger.kernel.org.html + +Emails with HTML will be automatically rejected by the mail server. + +It could be wise to also copy the relevant Media Maintainer(s). You should use +``scripts/get_maintainers.pl`` to identify whom else needs to be copied. +Please always copy driver's authors and maintainers. + +To minimize the chance of merge conflicts for your patch series, and make it +easier to backport patches to stable Kernels, we recommend that you use the +following baseline for your patch series: + +1. Features for the next mainline release: + + - baseline shall be the ``media-committers.git next`` branch; + +2. Bug fixes for the next mainline release: + + - baseline shall be the ``media-committers.git next`` branch. If the + changes depend on a fix from the ``media-committers.git fixes`` + branch, then you can use that as baseline. + +3. Bug fixes for the current mainline release (-rcX): + + - baseline shall be the latest mainline -rcX release or the + ``media-committers.git fixes`` branch if changes depend on a mainline + fix that is not yet merged; + +.. Note:: + + See https://www.kernel.org/category/releases.html for an overview + about Kernel release types. + +Patches with fixes shall have: + +- a ``Fixes:`` tag pointing to the first commit that introduced the bug; +- when applicable, a ``Cc: stable@vger.kernel.org``. + +Patches that were fixing bugs publicly reported by someone at the +linux-media@vger.kernel.org mailing list shall have: + +- a ``Reported-by:`` tag immediately followed by a ``Closes:`` tag. + +Patches that change API shall update documentation accordingly at the +same patch series. + +See Documentation/process/index.rst for more details about e-mail submission. + +Once a patch is submitted, it may follow either one of the following +workflows: + +a. Media Maintainers' workflow: Media Maintainers post the Pull Requests, + which are handled by the Media Subsystem Maintainers:: + + +-------+ +------------+ +------+ +-------+ +---------------------+ + |e-mail |-->|picked up by|-->|code |-->|pull |-->|Subsystem Maintainers| + |to LMML| |Patchwork | |review| |request| |merge in | + | | | | | | | | |media-committers.git | + +-------+ +------------+ +------+ +-------+ +---------------------+ + + For this workflow, Pull Requests are generated by Media Maintainers with + Patchwork access. If you do not have Patchwork access, then please don't + submit Pull Requests, as they will not be processed. + +b. Media Committers' workflow: patches are handled by Media Maintainers with + commit rights:: + + +-------+ +------------+ +------+ +--------------------------+ + |e-mail |-->|picked up by|-->|code |-->|Media Committers merge in | + |to LMML| |Patchwork | |review| |media-committers.git | + +-------+ +------------+ +------+ +--------------------------+ + +When patches are picked up by +`Patchwork <https://patchwork.linuxtv.org/project/linux-media/list/>`_ +and when merged at media-committers, Media CI bots will check for errors and +may provide e-mail feedback about patch problems. When this happens, the patch +submitter must fix them or explain why the errors are false positives. + +Patches will only be moved to the next stage in these two workflows if they +pass on Media CI or if there are false-positives in the Media CI reports. + +For both workflows, all patches shall be properly reviewed at +linux-media@vger.kernel.org (LMML) before being merged in +``media-committers.git``. Media patches will be reviewed in a timely manner +by the maintainers and reviewers as listed in the MAINTAINERS file. + +Media Maintainers shall request reviews from other Media Maintainers and +developers where applicable, i.e. because those developers have more +knowledge about some areas that are changed by a patch. + +There shall be no open issues or unresolved or conflicting feedback +from anyone. Clear them up first. Defer to the Media Subsystem +Maintainers if needed. + +Failures during e-mail submission ++++++++++++++++++++++++++++++++++ + +Media's workflow is heavily based on Patchwork, meaning that, once a patch +is submitted, the e-mail will first be accepted by the mailing list +server, and, after a while, it should appear at: + + - https://patchwork.linuxtv.org/project/linux-media/list/ + +If it doesn't automatically appear there after some time [3]_, then +probably something went wrong on your submission. Please check if the +email is in plain text\ [4]_ only and if your emailer is not mangling +whitespaces before complaining or submitting them again. + +To troubleshoot problems, you should first check if the mailing list +server has accepted your patch, by looking at: + + - https://lore.kernel.org/linux-media/ + +If the patch is there and not at +`Patchwork <https://patchwork.linuxtv.org/project/linux-media/list/>`_, +it is likely that your e-mailer mangled the patch. Patchwork internally +has logic that checks if the received e-mail contains a valid patch. +Any whitespace and new line breakages mangling the patch won't be recognized by +`Patchwork <https://patchwork.linuxtv.org/project/linux-media/list/>`_, +and such a patch will be rejected. + +.. [3] It usually takes a few minutes for the patch to arrive, but + the e-mail server may be busy, so it may take a longer time + for a patch to be picked by + `Patchwork <https://patchwork.linuxtv.org/project/linux-media/list/>`_. + +.. [4] If your email contains HTML, the mailing list server will simply + drop it, without any further notice. + +.. _media-developers-gpg: + +Authentication for pull and merge requests +++++++++++++++++++++++++++++++++++++++++++ + +The authenticity of developers submitting Pull Requests and merge requests +shall be validated by using the Linux Kernel Web of Trust, with PGP signing +at some moment. See: :ref:`kernel_org_trust_repository`. + +With the Pull Request workflow, Pull Requests shall use PGP-signed tags. + +With the committers' workflow, this is ensured at the time merge request +rights will be granted to the gitlab instance used by the media-committers.git +tree, after receiving the e-mail documented in +:ref:`media-committer-agreement`. + +For more details about PGP signing, please read +Documentation/process/maintainer-pgp-guide.rst. + +Maintaining media maintainer status +----------------------------------- + +See :ref:`Maintain Media Status`. + +List of Media Maintainers +------------------------- + +The Media Maintainers listed here all have patchwork access and can +make Pull Requests or have commit rights. + +The Media Subsystem Maintainers are: + - Mauro Carvalho Chehab <mchehab@kernel.org> + - Hans Verkuil <hverkuil@kernel.org> + +The Media Core Maintainers are: + - Sakari Ailus <sakari.ailus@linux.intel.com> + + - Media controller drivers + - Core media controller framework + - ISP + - sensor drivers + - v4l2-async and v4l2-fwnode core frameworks + - v4l2-flash-led-class core framework + + - Mauro Carvalho Chehab <mchehab@kernel.org> + + - DVB + + - Laurent Pinchart <laurent.pinchart@ideasonboard.com> + + - Media controller drivers + - Core media controller framework + - ISP + + - Hans Verkuil <hverkuil@kernel.org> + + - V4L2 drivers + - V4L2 and videobuf2 core frameworks + - HDMI CEC drivers + - HDMI CEC core framework + + - Sean Young <sean@mess.org> + + - Remote Controller (infrared) drivers + - Remote Controller (infrared) core framework + +The Media Driver Maintainers responsible for specific areas are: + - Nicolas Dufresne <nicolas.dufresne@collabora.com> + + - Codec drivers + - M2M driver not otherwise delegated + + - Bryan O'Donoghue <bryan.odonoghue@linaro.org> + + - Qualcomm drivers + + - Ricardo Ribalda <ribalda@chromium.org> + + - Media-CI + +Submit Checklist Addendum +------------------------- + +Patches that change the Open Firmware/Device Tree bindings must be +reviewed by the Device Tree maintainers. So, DT maintainers should be +Cc:ed when those are submitted via devicetree@vger.kernel.org mailing +list. + +There is a set of compliance tools at https://git.linuxtv.org/v4l-utils.git/ +that should be used in order to check if the drivers are properly +implementing the media APIs: + +==================== ======================================================= +Type Utility +==================== ======================================================= +V4L2 drivers\ [5]_ ``v4l2-compliance`` +V4L2 virtual drivers ``contrib/test/test-media`` +CEC drivers ``cec-compliance`` +==================== ======================================================= + +.. [5] The ``v4l2-compliance`` utility also covers the media controller usage + inside V4L2 drivers. + +Those tests need to pass before the patches go upstream. + +Also, please notice that we build the Kernel with:: + + make CF=-D__CHECK_ENDIAN__ CONFIG_DEBUG_SECTION_MISMATCH=y C=1 W=1 CHECK=check_script + +Where the check script is:: + + #!/bin/bash + /devel/smatch/smatch -p=kernel $@ >&2 + /devel/sparse/sparse $@ >&2 + +Be sure to not introduce new warnings on your patches without a +very good reason. + +Please see `Media development workflow`_ for e-mail submission rules. + +Style Cleanup Patches ++++++++++++++++++++++ + +Style cleanups are welcome when they come together with other changes +at the files where the style changes will affect. + +We may accept pure standalone style cleanups, but they should ideally +be one patch for the whole subsystem (if the cleanup is low volume), +or at least be grouped per directory. So, for example, if you're doing a +big cleanup change set at drivers under drivers/media, please send a single +patch for all drivers under drivers/media/pci, another one for +drivers/media/usb and so on. + +Coding Style Addendum ++++++++++++++++++++++ + +Media development uses ``checkpatch.pl`` on strict mode to verify the code +style, e.g.:: + + $ ./scripts/checkpatch.pl --strict --max-line-length=80 + +In principle, patches should follow the coding style rules, but exceptions +are allowed if there are good reasons. On such case, maintainers and reviewers +may question about the rationale for not addressing the ``checkpatch.pl``. + +Please notice that the goal here is to improve code readability. On +a few cases, ``checkpatch.pl`` may actually point to something that would +look worse. So, you should use good sense. + +Note that addressing one ``checkpatch.pl`` issue (of any kind) alone may lead +to having longer lines than 80 characters per line. While this is not +strictly prohibited, efforts should be made towards staying within 80 +characters per line. This could include using re-factoring code that leads +to less indentation, shorter variable or function names and last but not +least, simply wrapping the lines. + +In particular, we accept lines with more than 80 columns: + + - on strings, as they shouldn't be broken due to line length limits; + - when a function or variable name needs to have a long identifier name, + which makes hard to honor the 80 columns limit; + - on arithmetic expressions, when breaking lines makes them harder to + read; + - when they avoid a line ending with an open parenthesis or an open + bracket. + +Key Cycle Dates +--------------- + +New submissions can be sent at any time, but if they are intended to hit the +next merge window they should be sent before -rc5, and ideally stabilized +in the linux-media branch by -rc6. + +Review Cadence +-------------- + +Provided that your patch has landed in +`Patchwork <https://patchwork.linuxtv.org/project/linux-media/list/>`_, it +should be sooner or later handled, so you don't need to re-submit a patch. + +Except for important bug fixes, we don't usually add new patches to the +development tree between -rc6 and the next -rc1. + +Please notice that the media subsystem is a high traffic one, so it +could take a while for us to be able to review your patches. Feel free +to ping if you don't get a feedback in a couple of weeks or to ask +other developers to publicly add ``Reviewed-by:`` and, more importantly, +``Tested-by:`` tags. + +Please note that we expect a detailed description for ``Tested-by:``, +identifying what boards were used during the test and what it was tested. diff --git a/Documentation/driver-api/media/mc-core.rst b/Documentation/driver-api/media/mc-core.rst new file mode 100644 index 000000000..1d010bd7e --- /dev/null +++ b/Documentation/driver-api/media/mc-core.rst @@ -0,0 +1,341 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Media Controller devices +------------------------ + +Media Controller +~~~~~~~~~~~~~~~~ + +The media controller userspace API is documented in +:ref:`the Media Controller uAPI book <media_controller>`. This document focus +on the kernel-side implementation of the media framework. + +Abstract media device model +^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Discovering a device internal topology, and configuring it at runtime, is one +of the goals of the media framework. To achieve this, hardware devices are +modelled as an oriented graph of building blocks called entities connected +through pads. + +An entity is a basic media hardware building block. It can correspond to +a large variety of logical blocks such as physical hardware devices +(CMOS sensor for instance), logical hardware devices (a building block +in a System-on-Chip image processing pipeline), DMA channels or physical +connectors. + +A pad is a connection endpoint through which an entity can interact with +other entities. Data (not restricted to video) produced by an entity +flows from the entity's output to one or more entity inputs. Pads should +not be confused with physical pins at chip boundaries. + +A link is a point-to-point oriented connection between two pads, either +on the same entity or on different entities. Data flows from a source +pad to a sink pad. + +Media device +^^^^^^^^^^^^ + +A media device is represented by a struct media_device +instance, defined in ``include/media/media-device.h``. +Allocation of the structure is handled by the media device driver, usually by +embedding the :c:type:`media_device` instance in a larger driver-specific +structure. + +Drivers initialise media device instances by calling +:c:func:`media_device_init()`. After initialising a media device instance, it is +registered by calling :c:func:`__media_device_register()` via the macro +``media_device_register()`` and unregistered by calling +:c:func:`media_device_unregister()`. An initialised media device must be +eventually cleaned up by calling :c:func:`media_device_cleanup()`. + +Note that it is not allowed to unregister a media device instance that was not +previously registered, or clean up a media device instance that was not +previously initialised. + +Entities +^^^^^^^^ + +Entities are represented by a struct media_entity +instance, defined in ``include/media/media-entity.h``. The structure is usually +embedded into a higher-level structure, such as +:c:type:`v4l2_subdev` or :c:type:`video_device` +instances, although drivers can allocate entities directly. + +Drivers initialize entity pads by calling +:c:func:`media_entity_pads_init()`. + +Drivers register entities with a media device by calling +:c:func:`media_device_register_entity()` +and unregistered by calling +:c:func:`media_device_unregister_entity()`. + +Interfaces +^^^^^^^^^^ + +Interfaces are represented by a +struct media_interface instance, defined in +``include/media/media-entity.h``. Currently, only one type of interface is +defined: a device node. Such interfaces are represented by a +struct media_intf_devnode. + +Drivers initialize and create device node interfaces by calling +:c:func:`media_devnode_create()` +and remove them by calling: +:c:func:`media_devnode_remove()`. + +Pads +^^^^ +Pads are represented by a struct media_pad instance, +defined in ``include/media/media-entity.h``. Each entity stores its pads in +a pads array managed by the entity driver. Drivers usually embed the array in +a driver-specific structure. + +Pads are identified by their entity and their 0-based index in the pads +array. + +Both information are stored in the struct media_pad, +making the struct media_pad pointer the canonical way +to store and pass link references. + +Pads have flags that describe the pad capabilities and state. + +``MEDIA_PAD_FL_SINK`` indicates that the pad supports sinking data. +``MEDIA_PAD_FL_SOURCE`` indicates that the pad supports sourcing data. + +.. note:: + + One and only one of ``MEDIA_PAD_FL_SINK`` or ``MEDIA_PAD_FL_SOURCE`` must + be set for each pad. + +Links +^^^^^ + +Links are represented by a struct media_link instance, +defined in ``include/media/media-entity.h``. There are two types of links: + +**1. pad to pad links**: + +Associate two entities via their PADs. Each entity has a list that points +to all links originating at or targeting any of its pads. +A given link is thus stored twice, once in the source entity and once in +the target entity. + +Drivers create pad to pad links by calling: +:c:func:`media_create_pad_link()` and remove with +:c:func:`media_entity_remove_links()`. + +**2. interface to entity links**: + +Associate one interface to a Link. + +Drivers create interface to entity links by calling: +:c:func:`media_create_intf_link()` and remove with +:c:func:`media_remove_intf_links()`. + +.. note:: + + Links can only be created after having both ends already created. + +Links have flags that describe the link capabilities and state. The +valid values are described at :c:func:`media_create_pad_link()` and +:c:func:`media_create_intf_link()`. + +Graph traversal +^^^^^^^^^^^^^^^ + +The media framework provides APIs to traverse media graphs, locating connected +entities and links. + +To iterate over all entities belonging to a media device, drivers can use +the media_device_for_each_entity macro, defined in +``include/media/media-device.h``. + +.. code-block:: c + + struct media_entity *entity; + + media_device_for_each_entity(entity, mdev) { + // entity will point to each entity in turn + ... + } + +Helper functions can be used to find a link between two given pads, or a pad +connected to another pad through an enabled link +(:c:func:`media_entity_find_link()`, :c:func:`media_pad_remote_pad_first()`, +:c:func:`media_entity_remote_source_pad_unique()` and +:c:func:`media_pad_remote_pad_unique()`). + +Use count and power handling +^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Due to the wide differences between drivers regarding power management +needs, the media controller does not implement power management. However, +the struct media_entity includes a ``use_count`` +field that media drivers +can use to track the number of users of every entity for power management +needs. + +The :c:type:`media_entity<media_entity>`.\ ``use_count`` field is owned by +media drivers and must not be +touched by entity drivers. Access to the field must be protected by the +:c:type:`media_device`.\ ``graph_mutex`` lock. + +Links setup +^^^^^^^^^^^ + +Link properties can be modified at runtime by calling +:c:func:`media_entity_setup_link()`. + +Pipelines and media streams +^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +A media stream is a stream of pixels or metadata originating from one or more +source devices (such as a sensors) and flowing through media entity pads +towards the final sinks. The stream can be modified on the route by the +devices (e.g. scaling or pixel format conversions), or it can be split into +multiple branches, or multiple branches can be merged. + +A media pipeline is a set of media streams which are interdependent. This +interdependency can be caused by the hardware (e.g. configuration of a second +stream cannot be changed if the first stream has been enabled) or by the driver +due to the software design. Most commonly a media pipeline consists of a single +stream which does not branch. + +When starting streaming, drivers must notify all entities in the pipeline to +prevent link states from being modified during streaming by calling +:c:func:`media_pipeline_start()`. + +The function will mark all the pads which are part of the pipeline as streaming. + +The struct media_pipeline instance pointed to by the pipe argument will be +stored in every pad in the pipeline. Drivers should embed the struct +media_pipeline in higher-level pipeline structures and can then access the +pipeline through the struct media_pad pipe field. + +Calls to :c:func:`media_pipeline_start()` can be nested. +The pipeline pointer must be identical for all nested calls to the function. + +:c:func:`media_pipeline_start()` may return an error. In that case, +it will clean up any of the changes it did by itself. + +When stopping the stream, drivers must notify the entities with +:c:func:`media_pipeline_stop()`. + +If multiple calls to :c:func:`media_pipeline_start()` have been +made the same number of :c:func:`media_pipeline_stop()` calls +are required to stop streaming. +The :c:type:`media_entity`.\ ``pipe`` field is reset to ``NULL`` on the last +nested stop call. + +Link configuration will fail with ``-EBUSY`` by default if either end of the +link is a streaming entity. Links that can be modified while streaming must +be marked with the ``MEDIA_LNK_FL_DYNAMIC`` flag. + +If other operations need to be disallowed on streaming entities (such as +changing entities configuration parameters) drivers can explicitly check the +media_entity stream_count field to find out if an entity is streaming. This +operation must be done with the media_device graph_mutex held. + +Link validation +^^^^^^^^^^^^^^^ + +Link validation is performed by :c:func:`media_pipeline_start()` +for any entity which has sink pads in the pipeline. The +:c:type:`media_entity`.\ ``link_validate()`` callback is used for that +purpose. In ``link_validate()`` callback, entity driver should check +that the properties of the source pad of the connected entity and its own +sink pad match. It is up to the type of the entity (and in the end, the +properties of the hardware) what matching actually means. + +Subsystems should facilitate link validation by providing subsystem specific +helper functions to provide easy access for commonly needed information, and +in the end provide a way to use driver-specific callbacks. + +Pipeline traversal +^^^^^^^^^^^^^^^^^^ + +Once a pipeline has been constructed with :c:func:`media_pipeline_start()`, +drivers can iterate over entities or pads in the pipeline with the +:c:macro:´media_pipeline_for_each_entity` and +:c:macro:´media_pipeline_for_each_pad` macros. Iterating over pads is +straightforward: + +.. code-block:: c + + media_pipeline_pad_iter iter; + struct media_pad *pad; + + media_pipeline_for_each_pad(pipe, &iter, pad) { + /* 'pad' will point to each pad in turn */ + ... + } + +To iterate over entities, the iterator needs to be initialized and cleaned up +as an additional steps: + +.. code-block:: c + + media_pipeline_entity_iter iter; + struct media_entity *entity; + int ret; + + ret = media_pipeline_entity_iter_init(pipe, &iter); + if (ret) + ...; + + media_pipeline_for_each_entity(pipe, &iter, entity) { + /* 'entity' will point to each entity in turn */ + ... + } + + media_pipeline_entity_iter_cleanup(&iter); + +Media Controller Device Allocator API +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +When the media device belongs to more than one driver, the shared media +device is allocated with the shared struct device as the key for look ups. + +The shared media device should stay in registered state until the last +driver unregisters it. In addition, the media device should be released when +all the references are released. Each driver gets a reference to the media +device during probe, when it allocates the media device. If media device is +already allocated, the allocate API bumps up the refcount and returns the +existing media device. The driver puts the reference back in its disconnect +routine when it calls :c:func:`media_device_delete()`. + +The media device is unregistered and cleaned up from the kref put handler to +ensure that the media device stays in registered state until the last driver +unregisters the media device. + +**Driver Usage** + +Drivers should use the appropriate media-core routines to manage the shared +media device life-time handling the two states: +1. allocate -> register -> delete +2. get reference to already registered device -> delete + +call :c:func:`media_device_delete()` routine to make sure the shared media +device delete is handled correctly. + +**driver probe:** +Call :c:func:`media_device_usb_allocate()` to allocate or get a reference +Call :c:func:`media_device_register()`, if media devnode isn't registered + +**driver disconnect:** +Call :c:func:`media_device_delete()` to free the media_device. Freeing is +handled by the kref put handler. + +API Definitions +^^^^^^^^^^^^^^^ + +.. kernel-doc:: include/media/media-device.h + +.. kernel-doc:: include/media/media-devnode.h + +.. kernel-doc:: include/media/media-entity.h + +.. kernel-doc:: include/media/media-request.h + +.. kernel-doc:: include/media/media-dev-allocator.h diff --git a/Documentation/driver-api/media/media-committers.rst b/Documentation/driver-api/media/media-committers.rst new file mode 100644 index 000000000..a905856f6 --- /dev/null +++ b/Documentation/driver-api/media/media-committers.rst @@ -0,0 +1,203 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. _Media Committers: + +Media Committers +================ + +Who is a Media Committer? +------------------------- + +A Media Committer is a Media Maintainer with patchwork access who has been +granted commit access to push patches from other developers and their own +patches to the +`media-committers <https://gitlab.freedesktop.org/linux-media/media-committers>`_ +tree. + +These commit rights are granted with expectation of responsibility: +committers are people who care about the Linux Kernel as a whole and +about the Linux media subsystem and want to advance its development. It +is also based on a trust relationship among other committers, maintainers +and the Linux Media community. + +As Media Committer you have the following additional responsibilities: + +1. Patches you authored must have a ``Signed-off-by``, ``Reviewed-by`` + or ``Acked-by`` from another Media Maintainer; +2. If a patch introduces a regression, then that must be corrected as soon + as possible. Typically the patch is either reverted, or an additional + patch is committed to fix the regression; +3. If patches are fixing bugs against already released Kernels, including + the reverts mentioned above, the Media Committer shall add the needed + tags. Please see :ref:`Media development workflow` for more details. +4. All Media Committers are responsible for maintaining + `Patchwork <https://patchwork.linuxtv.org/project/linux-media/list/>`_, + updating the state of the patches they review or merge. + + +Becoming a Media Committer +-------------------------- + +Existing Media Committers can nominate a Media Maintainer to be granted +commit rights. The Media Maintainer must have patchwork access, +have been reviewing patches from third parties for some time, and has +demonstrated a good understanding of the maintainer's duties and processes. + +The ultimate responsibility for accepting a nominated committer is up to +the Media Subsystem Maintainers. The nominated committer must have earned a +trust relationship with all Media Subsystem Maintainers, as, by granting you +commit rights, part of their responsibilities are handed over to you. + +Due to that, to become a Media Committer, a consensus between all Media +Subsystem Maintainers is required. + +.. Note:: + + In order to preserve/protect the developers that could have their commit + rights granted, denied or removed as well as the subsystem maintainers who + have the task to accept or deny commit rights, all communication related to + changing commit rights should happen in private as much as possible. + +.. _media-committer-agreement: + +Media Committer's agreement +--------------------------- + +Once a nominated committer is accepted by all Media Subsystem Maintainers, +they will ask if the developer is interested in the nomination and discuss +what area(s) of the media subsystem the committer will be responsible for. +Those areas will typically be the same as the areas that the nominated +committer is already maintaining. + +When the developer accepts being a committer, the new committer shall +explicitly accept the Kernel development policies described under its +Documentation/, and in particular to the rules in this document, by writing +an e-mail to media-committers@linuxtv.org, with a declaration of intent +following the model below:: + + I, John Doe, would like to change my status to: Committer + + As Media Maintainer I accept commit rights for the following areas of + the media subsystem: + + ... + + For the purpose of committing patches to the media-committers tree, + I'll be using my user https://gitlab.freedesktop.org/users/<username>. + +Followed by a formal declaration of agreement with the Kernel development +rules:: + + I agree to follow the Kernel development rules described at: + + https://www.kernel.org/doc/html/latest/driver-api/media/media-committers.rst + + and to the Linux Kernel development process rules. + + I agree to abide by the Code of Conduct as documented in: + https://www.kernel.org/doc/html/latest/process/code-of-conduct.rst + + I am aware that I can, at any point of time, retire. In that case, I will + send an e-mail to notify the Media Subsystem Maintainers for them to revoke + my commit rights. + + I am aware that the Kernel development rules change over time. + By doing a new push to media-committers tree, I understand that I agree + to follow the rules in effect at the time of the commit. + +That e-mail shall be signed via the Kernel Web of trust with a PGP key cross +signed by other Kernel and media developers. As described at +:ref:`media-developers-gpg`, the PGP signature, together with the gitlab user +security are fundamental components that ensure the authenticity of the merge +requests that will happen at the media-committers.git tree. + +In case the kernel development process changes, by merging new commits to the +`media-committers tree <https://gitlab.freedesktop.org/linux-media/media-committers>`_, +the Media Committer implicitly declares their agreement with the latest +version of the documented process including the contents of this file. + +If a Media Committer decides to retire, it is the committer's duty to +notify the Media Subsystem Maintainers about that decision. + +.. note:: + + 1. Changes to the kernel media development process shall be announced in + the media-committers mailing list with a reasonable review period. All + committers are automatically subscribed to that mailing list; + 2. Due to the distributed nature of the Kernel development, it is + possible that kernel development process changes may end being + reviewed/merged at the Linux Docs and/or at the Linux Kernel mailing + lists, especially for the contents under Documentation/process and for + trivial typo fixes. + +Media Core Committers +--------------------- + +A Media Core Committer is a Media Core Maintainer with commit rights. + +As described in Documentation/driver-api/media/maintainer-entry-profile.rst, +a Media Core Maintainer maintains media core frameworks as well, besides +just drivers, and so is allowed to change core files and the media subsystem's +Kernel API. The extent of the core committer's grants will be detailed by the +Media Subsystem Maintainers when they nominate a Media Core Committer. + +Existing Media Committers may become Media Core Committers and vice versa. +Such decisions will be taken in consensus among the Media Subsystem +Maintainers. + +Media committers rules +---------------------- + +Media committers shall do their best efforts to avoid merging patches that +would break any existing drivers. If it breaks, fixup or revert patches +shall be merged as soon as possible, aiming to be merged at the same Kernel +cycle the bug is reported. + +Media committers shall behave accordingly to the rights granted by +the Media Subsystem Maintainers, especially with regards of the scope of changes +they may apply directly at the media-committers tree. That scope can +change over time on a mutual agreement between Media Committers and +Media Subsystem Maintainers. + +The Media Committer workflow is described at :ref:`Media development workflow`. + +.. _Maintain Media Status: + +Maintaining Media Maintainer or Committer status +------------------------------------------------ + +A community of maintainers working together to move the Linux Kernel +forward is essential to creating successful projects that are rewarding +to work on. If there are problems or disagreements within the community, +they can usually be solved through healthy discussion and debate. + +In the unhappy event that a Media Maintainer or Committer continues to +disregard good citizenship (or actively disrupts the project), we may need +to revoke that person's status. In such cases, if someone suggests the +revocation with a good reason, then after discussing this among the Media +Maintainers, the final decision is taken by the Media Subsystem Maintainers. + +As the decision to become a Media Maintainer or Committer comes from a +consensus between Media Subsystem Maintainers, a single Media Subsystem +Maintainer not trusting the Media Maintainer or Committer anymore is enough +to revoke their maintenance, Patchwork grants and/or commit rights. + +Having commit rights revoked doesn't prevent Media Maintainers to keep +contributing to the subsystem either via the pull request or via email workflow +as documented at the :ref:`Media development workflow`. + +If a maintainer is inactive for more than a couple of Kernel cycles, +maintainers will try to reach you via e-mail. If not possible, they may +revoke their maintainer/patchwork and committer rights and update MAINTAINERS +file entries accordingly. If you wish to resume contributing as maintainer +later on, then contact the Media Subsystem Maintainers to ask if your +maintenance, Patchwork grants and commit rights can be restored. + +References +---------- + +Much of this was inspired by/copied from the committer policies of: + +- `Chromium <https://chromium.googlesource.com/chromium/src/+/main/docs/contributing.md>`_; +- `WebKit <https://webkit.org/commit-and-review-policy/>`_; +- `Mozilla <https://www.mozilla.org/hacking/committer/>`_. diff --git a/Documentation/driver-api/media/rc-core.rst b/Documentation/driver-api/media/rc-core.rst new file mode 100644 index 000000000..53f5e643b --- /dev/null +++ b/Documentation/driver-api/media/rc-core.rst @@ -0,0 +1,88 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Remote Controller devices +------------------------- + +Remote Controller core +~~~~~~~~~~~~~~~~~~~~~~ + +The remote controller core implements infrastructure to receive and send +remote controller keyboard keystrokes and mouse events. + +Every time a key is pressed on a remote controller, a scan code is produced. +Also, on most hardware, keeping a key pressed for more than a few dozens of +milliseconds produce a repeat key event. That's somewhat similar to what +a normal keyboard or mouse is handled internally on Linux\ [#f1]_. So, the +remote controller core is implemented on the top of the linux input/evdev +interface. + +.. [#f1] + + The main difference is that, on keyboard events, the keyboard controller + produces one event for a key press and another one for key release. On + infrared-based remote controllers, there's no key release event. Instead, + an extra code is produced to indicate key repeats. + +However, most of the remote controllers use infrared (IR) to transmit signals. +As there are several protocols used to modulate infrared signals, one +important part of the core is dedicated to adjust the driver and the core +system to support the infrared protocol used by the emitter. + +The infrared transmission is done by blinking a infrared emitter using a +carrier. The carrier can be switched on or off by the IR transmitter +hardware. When the carrier is switched on, it is called *PULSE*. +When the carrier is switched off, it is called *SPACE*. + +In other words, a typical IR transmission can be viewed as a sequence of +*PULSE* and *SPACE* events, each with a given duration. + +The carrier parameters (frequency, duty cycle) and the intervals for +*PULSE* and *SPACE* events depend on the protocol. +For example, the NEC protocol uses a carrier of 38kHz, and transmissions +start with a 9ms *PULSE* and a 4.5ms SPACE. It then transmits 16 bits of +scan code, being 8 bits for address (usually it is a fixed number for a +given remote controller), followed by 8 bits of code. A bit "1" is modulated +with 560µs *PULSE* followed by 1690µs *SPACE* and a bit "0" is modulated +with 560µs *PULSE* followed by 560µs *SPACE*. + +At receiver, a simple low-pass filter can be used to convert the received +signal in a sequence of *PULSE/SPACE* events, filtering out the carrier +frequency. Due to that, the receiver doesn't care about the carrier's +actual frequency parameters: all it has to do is to measure the amount +of time it receives *PULSE/SPACE* events. +So, a simple IR receiver hardware will just provide a sequence of timings +for those events to the Kernel. The drivers for hardware with such kind of +receivers are identified by ``RC_DRIVER_IR_RAW``, as defined by +:c:type:`rc_driver_type`\ [#f2]_. Other hardware come with a +microcontroller that decode the *PULSE/SPACE* sequence and return scan +codes to the Kernel. Such kind of receivers are identified +by ``RC_DRIVER_SCANCODE``. + +.. [#f2] + + The RC core also supports devices that have just IR emitters, + without any receivers. Right now, all such devices work only in + raw TX mode. Such kind of hardware is identified as + ``RC_DRIVER_IR_RAW_TX``. + +When the RC core receives events produced by ``RC_DRIVER_IR_RAW`` IR +receivers, it needs to decode the IR protocol, in order to obtain the +corresponding scan code. The protocols supported by the RC core are +defined at enum :c:type:`rc_proto`. + +When the RC code receives a scan code (either directly, by a driver +of the type ``RC_DRIVER_SCANCODE``, or via its IR decoders), it needs +to convert into a Linux input event code. This is done via a mapping +table. + +The Kernel has support for mapping tables available on most media +devices. It also supports loading a table in runtime, via some +sysfs nodes. See the :ref:`RC userspace API <Remote_controllers_Intro>` +for more details. + +Remote controller data structures and functions +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +.. kernel-doc:: include/media/rc-core.h + +.. kernel-doc:: include/media/rc-map.h diff --git a/Documentation/driver-api/media/tx-rx.rst b/Documentation/driver-api/media/tx-rx.rst new file mode 100644 index 000000000..7df240781 --- /dev/null +++ b/Documentation/driver-api/media/tx-rx.rst @@ -0,0 +1,145 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. _transmitter-receiver: + +Pixel data transmitter and receiver drivers +=========================================== + +V4L2 supports various devices that transmit and receive pixel data. Examples of +these devices include a camera sensor, a TV tuner and a parallel, a BT.656 or a +CSI-2 receiver in an SoC. + +Bus types +--------- + +The following buses are the most common. This section discusses these two only. + +MIPI CSI-2 +^^^^^^^^^^ + +CSI-2 is a data bus intended for transferring images from cameras to +the host SoC. It is defined by the `MIPI alliance`_. + +.. _`MIPI alliance`: https://www.mipi.org/ + +Parallel and BT.656 +^^^^^^^^^^^^^^^^^^^ + +The parallel and `BT.656`_ buses transport one bit of data on each clock cycle +per data line. The parallel bus uses synchronisation and other additional +signals whereas BT.656 embeds synchronisation. + +.. _`BT.656`: https://en.wikipedia.org/wiki/ITU-R_BT.656 + +Transmitter drivers +------------------- + +Transmitter drivers generally need to provide the receiver drivers with the +configuration of the transmitter. What is required depends on the type of the +bus. These are common for both buses. + +Media bus pixel code +^^^^^^^^^^^^^^^^^^^^ + +See :ref:`v4l2-mbus-pixelcode`. + +Link frequency +^^^^^^^^^^^^^^ + +The :ref:`V4L2_CID_LINK_FREQ <v4l2-cid-link-freq>` control is used to tell the +receiver the frequency of the bus (i.e. it is not the same as the symbol rate). + +Drivers that do not have user-configurable link frequency should report it +through the ``.get_mbus_config()`` subdev pad operation, in the ``link_freq`` +field of struct v4l2_mbus_config, instead of through controls. + +Receiver drivers should use :c:func:`v4l2_get_link_freq` helper to obtain the +link frequency from the transmitter sub-device. + +``.enable_streams()`` and ``.disable_streams()`` callbacks +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The struct v4l2_subdev_pad_ops->enable_streams() and struct +v4l2_subdev_pad_ops->disable_streams() callbacks are used by the receiver driver +to control the transmitter driver's streaming state. These callbacks may not be +called directly, but by using ``v4l2_subdev_enable_streams()`` and +``v4l2_subdev_disable_streams()``. + +Stopping the transmitter +^^^^^^^^^^^^^^^^^^^^^^^^ + +A transmitter stops sending the stream of images as a result of +calling the ``.disable_streams()`` callback. Some transmitters may stop the +stream at a frame boundary whereas others stop immediately, +effectively leaving the current frame unfinished. The receiver driver +should not make assumptions either way, but function properly in both +cases. + +CSI-2 transmitter drivers +------------------------- + +Pixel rate +^^^^^^^^^^ + +The pixel rate on the bus is calculated as follows:: + + pixel_rate = link_freq * 2 * nr_of_lanes * 16 / k / bits_per_sample + +where + +.. list-table:: variables in pixel rate calculation + :header-rows: 1 + + * - variable or constant + - description + * - link_freq + - The value of the :ref:`V4L2_CID_LINK_FREQ <v4l2-cid-link-freq>` integer64 + menu item. + * - nr_of_lanes + - Number of data lanes used on the CSI-2 link. + * - 2 + - Data is transferred on both rising and falling edge of the signal. + * - bits_per_sample + - Number of bits per sample. + * - k + - 16 for D-PHY and 7 for C-PHY. + +Information on whether D-PHY or C-PHY is used, and the value of ``nr_of_lanes``, can be obtained from the OF endpoint configuration. + +.. note:: + + The pixel rate calculated this way is **not** the same thing as the + pixel rate on the camera sensor's pixel array which is indicated by the + :ref:`V4L2_CID_PIXEL_RATE <v4l2-cid-pixel-rate>` control. + +LP-11 and LP-111 states +^^^^^^^^^^^^^^^^^^^^^^^ + +As part of transitioning to high speed mode, a CSI-2 transmitter typically +briefly sets the bus to LP-11 or LP-111 state, depending on the PHY. This period +may be as short as 100 µs, during which the receiver observes this state and +proceeds its own part of high speed mode transition. + +Most receivers are capable of autonomously handling this once the software has +configured them to do so, but there are receivers which require software +involvement in observing LP-11 or LP-111 state. 100 µs is a brief period to hit +in software, especially when there is no interrupt telling something is +happening. + +One way to address this is to configure the transmitter side explicitly to LP-11 +or LP-111 state, which requires support from the transmitter hardware. This is +not universally available. Many devices return to this state once streaming is +stopped while the state after power-on is LP-00 or LP-000. + +The ``.pre_streamon()`` callback may be used to prepare a transmitter for +transitioning to streaming state, but not yet start streaming. Similarly, the +``.post_streamoff()`` callback is used to undo what was done by the +``.pre_streamon()`` callback. The caller of ``.pre_streamon()`` is thus required +to call ``.post_streamoff()`` for each successful call of ``.pre_streamon()``. + +In the context of CSI-2, the ``.pre_streamon()`` callback is used to transition +the transmitter to the LP-11 or LP-111 state. This also requires powering on the +device, so this should be only done when it is needed. + +Receiver drivers that do not need explicit LP-11 or LP-111 state setup are +waived from calling the two callbacks. diff --git a/Documentation/driver-api/media/v4l2-async.rst b/Documentation/driver-api/media/v4l2-async.rst new file mode 100644 index 000000000..3422330b3 --- /dev/null +++ b/Documentation/driver-api/media/v4l2-async.rst @@ -0,0 +1,5 @@ +.. SPDX-License-Identifier: GPL-2.0 + +V4L2 async kAPI +^^^^^^^^^^^^^^^ +.. kernel-doc:: include/media/v4l2-async.h diff --git a/Documentation/driver-api/media/v4l2-cci.rst b/Documentation/driver-api/media/v4l2-cci.rst new file mode 100644 index 000000000..dd297a40e --- /dev/null +++ b/Documentation/driver-api/media/v4l2-cci.rst @@ -0,0 +1,5 @@ +.. SPDX-License-Identifier: GPL-2.0 + +V4L2 CCI kAPI +^^^^^^^^^^^^^ +.. kernel-doc:: include/media/v4l2-cci.h diff --git a/Documentation/driver-api/media/v4l2-common.rst b/Documentation/driver-api/media/v4l2-common.rst new file mode 100644 index 000000000..b1e70eb56 --- /dev/null +++ b/Documentation/driver-api/media/v4l2-common.rst @@ -0,0 +1,8 @@ +.. SPDX-License-Identifier: GPL-2.0 + +V4L2 common functions and data structures +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +.. kernel-doc:: include/media/v4l2-common.h + +.. kernel-doc:: include/media/v4l2-ioctl.h diff --git a/Documentation/driver-api/media/v4l2-controls.rst b/Documentation/driver-api/media/v4l2-controls.rst new file mode 100644 index 000000000..fc0490758 --- /dev/null +++ b/Documentation/driver-api/media/v4l2-controls.rst @@ -0,0 +1,820 @@ +.. SPDX-License-Identifier: GPL-2.0 + +V4L2 Controls +============= + +Introduction +------------ + +The V4L2 control API seems simple enough, but quickly becomes very hard to +implement correctly in drivers. But much of the code needed to handle controls +is actually not driver specific and can be moved to the V4L core framework. + +After all, the only part that a driver developer is interested in is: + +1) How do I add a control? +2) How do I set the control's value? (i.e. s_ctrl) + +And occasionally: + +3) How do I get the control's value? (i.e. g_volatile_ctrl) +4) How do I validate the user's proposed control value? (i.e. try_ctrl) + +All the rest is something that can be done centrally. + +The control framework was created in order to implement all the rules of the +V4L2 specification with respect to controls in a central place. And to make +life as easy as possible for the driver developer. + +Note that the control framework relies on the presence of a struct +:c:type:`v4l2_device` for V4L2 drivers and struct v4l2_subdev for +sub-device drivers. + + +Objects in the framework +------------------------ + +There are two main objects: + +The :c:type:`v4l2_ctrl` object describes the control properties and keeps +track of the control's value (both the current value and the proposed new +value). + +:c:type:`v4l2_ctrl_handler` is the object that keeps track of controls. It +maintains a list of v4l2_ctrl objects that it owns and another list of +references to controls, possibly to controls owned by other handlers. + + +Basic usage for V4L2 and sub-device drivers +------------------------------------------- + +1) Prepare the driver: + +.. code-block:: c + + #include <media/v4l2-ctrls.h> + +1.1) Add the handler to your driver's top-level struct: + +For V4L2 drivers: + +.. code-block:: c + + struct foo_dev { + ... + struct v4l2_device v4l2_dev; + ... + struct v4l2_ctrl_handler ctrl_handler; + ... + }; + +For sub-device drivers: + +.. code-block:: c + + struct foo_dev { + ... + struct v4l2_subdev sd; + ... + struct v4l2_ctrl_handler ctrl_handler; + ... + }; + +1.2) Initialize the handler: + +.. code-block:: c + + v4l2_ctrl_handler_init(&foo->ctrl_handler, nr_of_controls); + +The second argument is a hint telling the function how many controls this +handler is expected to handle. It will allocate a hashtable based on this +information. It is a hint only. + +1.3) Hook the control handler into the driver: + +For V4L2 drivers: + +.. code-block:: c + + foo->v4l2_dev.ctrl_handler = &foo->ctrl_handler; + +For sub-device drivers: + +.. code-block:: c + + foo->sd.ctrl_handler = &foo->ctrl_handler; + +1.4) Clean up the handler at the end: + +.. code-block:: c + + v4l2_ctrl_handler_free(&foo->ctrl_handler); + +:c:func:`v4l2_ctrl_handler_free` does not touch the handler's ``error`` field. + +2) Add controls: + +You add non-menu controls by calling :c:func:`v4l2_ctrl_new_std`: + +.. code-block:: c + + struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl, + const struct v4l2_ctrl_ops *ops, + u32 id, s32 min, s32 max, u32 step, s32 def); + +Menu and integer menu controls are added by calling +:c:func:`v4l2_ctrl_new_std_menu`: + +.. code-block:: c + + struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl, + const struct v4l2_ctrl_ops *ops, + u32 id, s32 max, s32 skip_mask, s32 def); + +Menu controls with a driver specific menu are added by calling +:c:func:`v4l2_ctrl_new_std_menu_items`: + +.. code-block:: c + + struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items( + struct v4l2_ctrl_handler *hdl, + const struct v4l2_ctrl_ops *ops, u32 id, s32 max, + s32 skip_mask, s32 def, const char * const *qmenu); + +Standard compound controls can be added by calling +:c:func:`v4l2_ctrl_new_std_compound`: + +.. code-block:: c + + struct v4l2_ctrl *v4l2_ctrl_new_std_compound(struct v4l2_ctrl_handler *hdl, + const struct v4l2_ctrl_ops *ops, u32 id, + const union v4l2_ctrl_ptr p_def); + +Integer menu controls with a driver specific menu can be added by calling +:c:func:`v4l2_ctrl_new_int_menu`: + +.. code-block:: c + + struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl, + const struct v4l2_ctrl_ops *ops, + u32 id, s32 max, s32 def, const s64 *qmenu_int); + +These functions are typically called right after the +:c:func:`v4l2_ctrl_handler_init`: + +.. code-block:: c + + static const s64 exp_bias_qmenu[] = { + -2, -1, 0, 1, 2 + }; + static const char * const test_pattern[] = { + "Disabled", + "Vertical Bars", + "Solid Black", + "Solid White", + }; + + v4l2_ctrl_handler_init(&foo->ctrl_handler, nr_of_controls); + v4l2_ctrl_new_std(&foo->ctrl_handler, &foo_ctrl_ops, + V4L2_CID_BRIGHTNESS, 0, 255, 1, 128); + v4l2_ctrl_new_std(&foo->ctrl_handler, &foo_ctrl_ops, + V4L2_CID_CONTRAST, 0, 255, 1, 128); + v4l2_ctrl_new_std_menu(&foo->ctrl_handler, &foo_ctrl_ops, + V4L2_CID_POWER_LINE_FREQUENCY, + V4L2_CID_POWER_LINE_FREQUENCY_60HZ, 0, + V4L2_CID_POWER_LINE_FREQUENCY_DISABLED); + v4l2_ctrl_new_int_menu(&foo->ctrl_handler, &foo_ctrl_ops, + V4L2_CID_EXPOSURE_BIAS, + ARRAY_SIZE(exp_bias_qmenu) - 1, + ARRAY_SIZE(exp_bias_qmenu) / 2 - 1, + exp_bias_qmenu); + v4l2_ctrl_new_std_menu_items(&foo->ctrl_handler, &foo_ctrl_ops, + V4L2_CID_TEST_PATTERN, ARRAY_SIZE(test_pattern) - 1, 0, + 0, test_pattern); + ... + if (foo->ctrl_handler.error) + return v4l2_ctrl_handler_free(&foo->ctrl_handler); + +The :c:func:`v4l2_ctrl_new_std` function returns the v4l2_ctrl pointer to +the new control, but if you do not need to access the pointer outside the +control ops, then there is no need to store it. + +The :c:func:`v4l2_ctrl_new_std` function will fill in most fields based on +the control ID except for the min, max, step and default values. These are +passed in the last four arguments. These values are driver specific while +control attributes like type, name, flags are all global. The control's +current value will be set to the default value. + +The :c:func:`v4l2_ctrl_new_std_menu` function is very similar but it is +used for menu controls. There is no min argument since that is always 0 for +menu controls, and instead of a step there is a skip_mask argument: if bit +X is 1, then menu item X is skipped. + +The :c:func:`v4l2_ctrl_new_int_menu` function creates a new standard +integer menu control with driver-specific items in the menu. It differs +from v4l2_ctrl_new_std_menu in that it doesn't have the mask argument and +takes as the last argument an array of signed 64-bit integers that form an +exact menu item list. + +The :c:func:`v4l2_ctrl_new_std_menu_items` function is very similar to +v4l2_ctrl_new_std_menu but takes an extra parameter qmenu, which is the +driver specific menu for an otherwise standard menu control. A good example +for this control is the test pattern control for capture/display/sensors +devices that have the capability to generate test patterns. These test +patterns are hardware specific, so the contents of the menu will vary from +device to device. + +Note that if something fails, the function will return NULL or an error and +set ctrl_handler->error to the error code. If ctrl_handler->error was already +set, then it will just return and do nothing. This is also true for +v4l2_ctrl_handler_init if it cannot allocate the internal data structure. + +This makes it easy to init the handler and just add all controls and only check +the error code at the end. Saves a lot of repetitive error checking. + +It is recommended to add controls in ascending control ID order: it will be +a bit faster that way. + +3) Optionally force initial control setup: + +.. code-block:: c + + v4l2_ctrl_handler_setup(&foo->ctrl_handler); + +This will call s_ctrl for all controls unconditionally. Effectively this +initializes the hardware to the default control values. It is recommended +that you do this as this ensures that both the internal data structures and +the hardware are in sync. + +4) Finally: implement the :c:type:`v4l2_ctrl_ops` + +.. code-block:: c + + static const struct v4l2_ctrl_ops foo_ctrl_ops = { + .s_ctrl = foo_s_ctrl, + }; + +Usually all you need is s_ctrl: + +.. code-block:: c + + static int foo_s_ctrl(struct v4l2_ctrl *ctrl) + { + struct foo *state = container_of(ctrl->handler, struct foo, ctrl_handler); + + switch (ctrl->id) { + case V4L2_CID_BRIGHTNESS: + write_reg(0x123, ctrl->val); + break; + case V4L2_CID_CONTRAST: + write_reg(0x456, ctrl->val); + break; + } + return 0; + } + +The control ops are called with the v4l2_ctrl pointer as argument. +The new control value has already been validated, so all you need to do is +to actually update the hardware registers. + +You're done! And this is sufficient for most of the drivers we have. No need +to do any validation of control values, or implement QUERYCTRL, QUERY_EXT_CTRL +and QUERYMENU. And G/S_CTRL as well as G/TRY/S_EXT_CTRLS are automatically supported. + + +.. note:: + + The remainder sections deal with more advanced controls topics and scenarios. + In practice the basic usage as described above is sufficient for most drivers. + + +Inheriting Sub-device Controls +------------------------------ + +When a sub-device is registered with a V4L2 driver by calling +v4l2_device_register_subdev() and the ctrl_handler fields of both v4l2_subdev +and v4l2_device are set, then the controls of the subdev will become +automatically available in the V4L2 driver as well. If the subdev driver +contains controls that already exist in the V4L2 driver, then those will be +skipped (so a V4L2 driver can always override a subdev control). + +What happens here is that v4l2_device_register_subdev() calls +v4l2_ctrl_add_handler() adding the controls of the subdev to the controls +of v4l2_device. + + +Accessing Control Values +------------------------ + +The following union is used inside the control framework to access control +values: + +.. code-block:: c + + union v4l2_ctrl_ptr { + s32 *p_s32; + s64 *p_s64; + char *p_char; + void *p; + }; + +The v4l2_ctrl struct contains these fields that can be used to access both +current and new values: + +.. code-block:: c + + s32 val; + struct { + s32 val; + } cur; + + + union v4l2_ctrl_ptr p_new; + union v4l2_ctrl_ptr p_cur; + +If the control has a simple s32 type, then: + +.. code-block:: c + + &ctrl->val == ctrl->p_new.p_s32 + &ctrl->cur.val == ctrl->p_cur.p_s32 + +For all other types use ctrl->p_cur.p<something>. Basically the val +and cur.val fields can be considered an alias since these are used so often. + +Within the control ops you can freely use these. The val and cur.val speak for +themselves. The p_char pointers point to character buffers of length +ctrl->maximum + 1, and are always 0-terminated. + +Unless the control is marked volatile the p_cur field points to the +current cached control value. When you create a new control this value is made +identical to the default value. After calling v4l2_ctrl_handler_setup() this +value is passed to the hardware. It is generally a good idea to call this +function. + +Whenever a new value is set that new value is automatically cached. This means +that most drivers do not need to implement the g_volatile_ctrl() op. The +exception is for controls that return a volatile register such as a signal +strength read-out that changes continuously. In that case you will need to +implement g_volatile_ctrl like this: + +.. code-block:: c + + static int foo_g_volatile_ctrl(struct v4l2_ctrl *ctrl) + { + switch (ctrl->id) { + case V4L2_CID_BRIGHTNESS: + ctrl->val = read_reg(0x123); + break; + } + } + +Note that you use the 'new value' union as well in g_volatile_ctrl. In general +controls that need to implement g_volatile_ctrl are read-only controls. If they +are not, a V4L2_EVENT_CTRL_CH_VALUE will not be generated when the control +changes. + +To mark a control as volatile you have to set V4L2_CTRL_FLAG_VOLATILE: + +.. code-block:: c + + ctrl = v4l2_ctrl_new_std(&sd->ctrl_handler, ...); + if (ctrl) + ctrl->flags |= V4L2_CTRL_FLAG_VOLATILE; + +For try/s_ctrl the new values (i.e. as passed by the user) are filled in and +you can modify them in try_ctrl or set them in s_ctrl. The 'cur' union +contains the current value, which you can use (but not change!) as well. + +If s_ctrl returns 0 (OK), then the control framework will copy the new final +values to the 'cur' union. + +While in g_volatile/s/try_ctrl you can access the value of all controls owned +by the same handler since the handler's lock is held. If you need to access +the value of controls owned by other handlers, then you have to be very careful +not to introduce deadlocks. + +Outside of the control ops you have to go through to helper functions to get +or set a single control value safely in your driver: + +.. code-block:: c + + s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl); + int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val); + +These functions go through the control framework just as VIDIOC_G/S_CTRL ioctls +do. Don't use these inside the control ops g_volatile/s/try_ctrl, though, that +will result in a deadlock since these helpers lock the handler as well. + +You can also take the handler lock yourself: + +.. code-block:: c + + mutex_lock(&state->ctrl_handler.lock); + pr_info("String value is '%s'\n", ctrl1->p_cur.p_char); + pr_info("Integer value is '%s'\n", ctrl2->cur.val); + mutex_unlock(&state->ctrl_handler.lock); + + +Menu Controls +------------- + +The v4l2_ctrl struct contains this union: + +.. code-block:: c + + union { + u32 step; + u32 menu_skip_mask; + }; + +For menu controls menu_skip_mask is used. What it does is that it allows you +to easily exclude certain menu items. This is used in the VIDIOC_QUERYMENU +implementation where you can return -EINVAL if a certain menu item is not +present. Note that VIDIOC_QUERYCTRL always returns a step value of 1 for +menu controls. + +A good example is the MPEG Audio Layer II Bitrate menu control where the +menu is a list of standardized possible bitrates. But in practice hardware +implementations will only support a subset of those. By setting the skip +mask you can tell the framework which menu items should be skipped. Setting +it to 0 means that all menu items are supported. + +You set this mask either through the v4l2_ctrl_config struct for a custom +control, or by calling v4l2_ctrl_new_std_menu(). + + +Custom Controls +--------------- + +Driver specific controls can be created using v4l2_ctrl_new_custom(): + +.. code-block:: c + + static const struct v4l2_ctrl_config ctrl_filter = { + .ops = &ctrl_custom_ops, + .id = V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER, + .name = "Spatial Filter", + .type = V4L2_CTRL_TYPE_INTEGER, + .flags = V4L2_CTRL_FLAG_SLIDER, + .max = 15, + .step = 1, + }; + + ctrl = v4l2_ctrl_new_custom(&foo->ctrl_handler, &ctrl_filter, NULL); + +The last argument is the priv pointer which can be set to driver-specific +private data. + +The v4l2_ctrl_config struct also has a field to set the is_private flag. + +If the name field is not set, then the framework will assume this is a standard +control and will fill in the name, type and flags fields accordingly. + + +Active and Grabbed Controls +--------------------------- + +If you get more complex relationships between controls, then you may have to +activate and deactivate controls. For example, if the Chroma AGC control is +on, then the Chroma Gain control is inactive. That is, you may set it, but +the value will not be used by the hardware as long as the automatic gain +control is on. Typically user interfaces can disable such input fields. + +You can set the 'active' status using v4l2_ctrl_activate(). By default all +controls are active. Note that the framework does not check for this flag. +It is meant purely for GUIs. The function is typically called from within +s_ctrl. + +The other flag is the 'grabbed' flag. A grabbed control means that you cannot +change it because it is in use by some resource. Typical examples are MPEG +bitrate controls that cannot be changed while capturing is in progress. + +If a control is set to 'grabbed' using v4l2_ctrl_grab(), then the framework +will return -EBUSY if an attempt is made to set this control. The +v4l2_ctrl_grab() function is typically called from the driver when it +starts or stops streaming. + + +Control Clusters +---------------- + +By default all controls are independent from the others. But in more +complex scenarios you can get dependencies from one control to another. +In that case you need to 'cluster' them: + +.. code-block:: c + + struct foo { + struct v4l2_ctrl_handler ctrl_handler; + #define AUDIO_CL_VOLUME (0) + #define AUDIO_CL_MUTE (1) + struct v4l2_ctrl *audio_cluster[2]; + ... + }; + + state->audio_cluster[AUDIO_CL_VOLUME] = + v4l2_ctrl_new_std(&state->ctrl_handler, ...); + state->audio_cluster[AUDIO_CL_MUTE] = + v4l2_ctrl_new_std(&state->ctrl_handler, ...); + v4l2_ctrl_cluster(ARRAY_SIZE(state->audio_cluster), state->audio_cluster); + +From now on whenever one or more of the controls belonging to the same +cluster is set (or 'gotten', or 'tried'), only the control ops of the first +control ('volume' in this example) is called. You effectively create a new +composite control. Similar to how a 'struct' works in C. + +So when s_ctrl is called with V4L2_CID_AUDIO_VOLUME as argument, you should set +all two controls belonging to the audio_cluster: + +.. code-block:: c + + static int foo_s_ctrl(struct v4l2_ctrl *ctrl) + { + struct foo *state = container_of(ctrl->handler, struct foo, ctrl_handler); + + switch (ctrl->id) { + case V4L2_CID_AUDIO_VOLUME: { + struct v4l2_ctrl *mute = ctrl->cluster[AUDIO_CL_MUTE]; + + write_reg(0x123, mute->val ? 0 : ctrl->val); + break; + } + case V4L2_CID_CONTRAST: + write_reg(0x456, ctrl->val); + break; + } + return 0; + } + +In the example above the following are equivalent for the VOLUME case: + +.. code-block:: c + + ctrl == ctrl->cluster[AUDIO_CL_VOLUME] == state->audio_cluster[AUDIO_CL_VOLUME] + ctrl->cluster[AUDIO_CL_MUTE] == state->audio_cluster[AUDIO_CL_MUTE] + +In practice using cluster arrays like this becomes very tiresome. So instead +the following equivalent method is used: + +.. code-block:: c + + struct { + /* audio cluster */ + struct v4l2_ctrl *volume; + struct v4l2_ctrl *mute; + }; + +The anonymous struct is used to clearly 'cluster' these two control pointers, +but it serves no other purpose. The effect is the same as creating an +array with two control pointers. So you can just do: + +.. code-block:: c + + state->volume = v4l2_ctrl_new_std(&state->ctrl_handler, ...); + state->mute = v4l2_ctrl_new_std(&state->ctrl_handler, ...); + v4l2_ctrl_cluster(2, &state->volume); + +And in foo_s_ctrl you can use these pointers directly: state->mute->val. + +Note that controls in a cluster may be NULL. For example, if for some +reason mute was never added (because the hardware doesn't support that +particular feature), then mute will be NULL. So in that case we have a +cluster of 2 controls, of which only 1 is actually instantiated. The +only restriction is that the first control of the cluster must always be +present, since that is the 'master' control of the cluster. The master +control is the one that identifies the cluster and that provides the +pointer to the v4l2_ctrl_ops struct that is used for that cluster. + +Obviously, all controls in the cluster array must be initialized to either +a valid control or to NULL. + +In rare cases you might want to know which controls of a cluster actually +were set explicitly by the user. For this you can check the 'is_new' flag of +each control. For example, in the case of a volume/mute cluster the 'is_new' +flag of the mute control would be set if the user called VIDIOC_S_CTRL for +mute only. If the user would call VIDIOC_S_EXT_CTRLS for both mute and volume +controls, then the 'is_new' flag would be 1 for both controls. + +The 'is_new' flag is always 1 when called from v4l2_ctrl_handler_setup(). + + +Handling autogain/gain-type Controls with Auto Clusters +------------------------------------------------------- + +A common type of control cluster is one that handles 'auto-foo/foo'-type +controls. Typical examples are autogain/gain, autoexposure/exposure, +autowhitebalance/red balance/blue balance. In all cases you have one control +that determines whether another control is handled automatically by the hardware, +or whether it is under manual control from the user. + +If the cluster is in automatic mode, then the manual controls should be +marked inactive and volatile. When the volatile controls are read the +g_volatile_ctrl operation should return the value that the hardware's automatic +mode set up automatically. + +If the cluster is put in manual mode, then the manual controls should become +active again and the volatile flag is cleared (so g_volatile_ctrl is no longer +called while in manual mode). In addition just before switching to manual mode +the current values as determined by the auto mode are copied as the new manual +values. + +Finally the V4L2_CTRL_FLAG_UPDATE should be set for the auto control since +changing that control affects the control flags of the manual controls. + +In order to simplify this a special variation of v4l2_ctrl_cluster was +introduced: + +.. code-block:: c + + void v4l2_ctrl_auto_cluster(unsigned ncontrols, struct v4l2_ctrl **controls, + u8 manual_val, bool set_volatile); + +The first two arguments are identical to v4l2_ctrl_cluster. The third argument +tells the framework which value switches the cluster into manual mode. The +last argument will optionally set V4L2_CTRL_FLAG_VOLATILE for the non-auto controls. +If it is false, then the manual controls are never volatile. You would typically +use that if the hardware does not give you the option to read back to values as +determined by the auto mode (e.g. if autogain is on, the hardware doesn't allow +you to obtain the current gain value). + +The first control of the cluster is assumed to be the 'auto' control. + +Using this function will ensure that you don't need to handle all the complex +flag and volatile handling. + + +VIDIOC_LOG_STATUS Support +------------------------- + +This ioctl allow you to dump the current status of a driver to the kernel log. +The v4l2_ctrl_handler_log_status(ctrl_handler, prefix) can be used to dump the +value of the controls owned by the given handler to the log. You can supply a +prefix as well. If the prefix didn't end with a space, then ': ' will be added +for you. + + +Different Handlers for Different Video Nodes +-------------------------------------------- + +Usually the V4L2 driver has just one control handler that is global for +all video nodes. But you can also specify different control handlers for +different video nodes. You can do that by manually setting the ctrl_handler +field of struct video_device. + +That is no problem if there are no subdevs involved but if there are, then +you need to block the automatic merging of subdev controls to the global +control handler. You do that by simply setting the ctrl_handler field in +struct v4l2_device to NULL. Now v4l2_device_register_subdev() will no longer +merge subdev controls. + +After each subdev was added, you will then have to call v4l2_ctrl_add_handler +manually to add the subdev's control handler (sd->ctrl_handler) to the desired +control handler. This control handler may be specific to the video_device or +for a subset of video_device's. For example: the radio device nodes only have +audio controls, while the video and vbi device nodes share the same control +handler for the audio and video controls. + +If you want to have one handler (e.g. for a radio device node) have a subset +of another handler (e.g. for a video device node), then you should first add +the controls to the first handler, add the other controls to the second +handler and finally add the first handler to the second. For example: + +.. code-block:: c + + v4l2_ctrl_new_std(&radio_ctrl_handler, &radio_ops, V4L2_CID_AUDIO_VOLUME, ...); + v4l2_ctrl_new_std(&radio_ctrl_handler, &radio_ops, V4L2_CID_AUDIO_MUTE, ...); + v4l2_ctrl_new_std(&video_ctrl_handler, &video_ops, V4L2_CID_BRIGHTNESS, ...); + v4l2_ctrl_new_std(&video_ctrl_handler, &video_ops, V4L2_CID_CONTRAST, ...); + v4l2_ctrl_add_handler(&video_ctrl_handler, &radio_ctrl_handler, NULL); + +The last argument to v4l2_ctrl_add_handler() is a filter function that allows +you to filter which controls will be added. Set it to NULL if you want to add +all controls. + +Or you can add specific controls to a handler: + +.. code-block:: c + + volume = v4l2_ctrl_new_std(&video_ctrl_handler, &ops, V4L2_CID_AUDIO_VOLUME, ...); + v4l2_ctrl_new_std(&video_ctrl_handler, &ops, V4L2_CID_BRIGHTNESS, ...); + v4l2_ctrl_new_std(&video_ctrl_handler, &ops, V4L2_CID_CONTRAST, ...); + +What you should not do is make two identical controls for two handlers. +For example: + +.. code-block:: c + + v4l2_ctrl_new_std(&radio_ctrl_handler, &radio_ops, V4L2_CID_AUDIO_MUTE, ...); + v4l2_ctrl_new_std(&video_ctrl_handler, &video_ops, V4L2_CID_AUDIO_MUTE, ...); + +This would be bad since muting the radio would not change the video mute +control. The rule is to have one control for each hardware 'knob' that you +can twiddle. + + +Finding Controls +---------------- + +Normally you have created the controls yourself and you can store the struct +v4l2_ctrl pointer into your own struct. + +But sometimes you need to find a control from another handler that you do +not own. For example, if you have to find a volume control from a subdev. + +You can do that by calling v4l2_ctrl_find: + +.. code-block:: c + + struct v4l2_ctrl *volume; + + volume = v4l2_ctrl_find(sd->ctrl_handler, V4L2_CID_AUDIO_VOLUME); + +Since v4l2_ctrl_find will lock the handler you have to be careful where you +use it. For example, this is not a good idea: + +.. code-block:: c + + struct v4l2_ctrl_handler ctrl_handler; + + v4l2_ctrl_new_std(&ctrl_handler, &video_ops, V4L2_CID_BRIGHTNESS, ...); + v4l2_ctrl_new_std(&ctrl_handler, &video_ops, V4L2_CID_CONTRAST, ...); + +...and in video_ops.s_ctrl: + +.. code-block:: c + + case V4L2_CID_BRIGHTNESS: + contrast = v4l2_find_ctrl(&ctrl_handler, V4L2_CID_CONTRAST); + ... + +When s_ctrl is called by the framework the ctrl_handler.lock is already taken, so +attempting to find another control from the same handler will deadlock. + +It is recommended not to use this function from inside the control ops. + + +Preventing Controls inheritance +------------------------------- + +When one control handler is added to another using v4l2_ctrl_add_handler, then +by default all controls from one are merged to the other. But a subdev might +have low-level controls that make sense for some advanced embedded system, but +not when it is used in consumer-level hardware. In that case you want to keep +those low-level controls local to the subdev. You can do this by simply +setting the 'is_private' flag of the control to 1: + +.. code-block:: c + + static const struct v4l2_ctrl_config ctrl_private = { + .ops = &ctrl_custom_ops, + .id = V4L2_CID_..., + .name = "Some Private Control", + .type = V4L2_CTRL_TYPE_INTEGER, + .max = 15, + .step = 1, + .is_private = 1, + }; + + ctrl = v4l2_ctrl_new_custom(&foo->ctrl_handler, &ctrl_private, NULL); + +These controls will now be skipped when v4l2_ctrl_add_handler is called. + + +V4L2_CTRL_TYPE_CTRL_CLASS Controls +---------------------------------- + +Controls of this type can be used by GUIs to get the name of the control class. +A fully featured GUI can make a dialog with multiple tabs with each tab +containing the controls belonging to a particular control class. The name of +each tab can be found by querying a special control with ID <control class | 1>. + +Drivers do not have to care about this. The framework will automatically add +a control of this type whenever the first control belonging to a new control +class is added. + + +Adding Notify Callbacks +----------------------- + +Sometimes the platform or bridge driver needs to be notified when a control +from a sub-device driver changes. You can set a notify callback by calling +this function: + +.. code-block:: c + + void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, + void (*notify)(struct v4l2_ctrl *ctrl, void *priv), void *priv); + +Whenever the give control changes value the notify callback will be called +with a pointer to the control and the priv pointer that was passed with +v4l2_ctrl_notify. Note that the control's handler lock is held when the +notify function is called. + +There can be only one notify function per control handler. Any attempt +to set another notify function will cause a WARN_ON. + +v4l2_ctrl functions and data structures +--------------------------------------- + +.. kernel-doc:: include/media/v4l2-ctrls.h diff --git a/Documentation/driver-api/media/v4l2-core.rst b/Documentation/driver-api/media/v4l2-core.rst new file mode 100644 index 000000000..a5f5102c6 --- /dev/null +++ b/Documentation/driver-api/media/v4l2-core.rst @@ -0,0 +1,30 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Video4Linux devices +------------------- + +.. toctree:: + :maxdepth: 1 + + v4l2-intro + v4l2-dev + v4l2-device + v4l2-fh + v4l2-subdev + v4l2-event + v4l2-controls + v4l2-videobuf2 + v4l2-dv-timings + v4l2-flash-led-class + v4l2-mc + v4l2-mediabus + v4l2-mem2mem + v4l2-async + v4l2-fwnode + v4l2-cci + v4l2-rect + v4l2-tuner + v4l2-common + v4l2-tveeprom + v4l2-jpeg + v4l2-isp diff --git a/Documentation/driver-api/media/v4l2-dev.rst b/Documentation/driver-api/media/v4l2-dev.rst new file mode 100644 index 000000000..dd239ad42 --- /dev/null +++ b/Documentation/driver-api/media/v4l2-dev.rst @@ -0,0 +1,367 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Video device' s internal representation +======================================= + +The actual device nodes in the ``/dev`` directory are created using the +:c:type:`video_device` struct (``v4l2-dev.h``). This struct can either be +allocated dynamically or embedded in a larger struct. + +To allocate it dynamically use :c:func:`video_device_alloc`: + +.. code-block:: c + + struct video_device *vdev = video_device_alloc(); + + if (vdev == NULL) + return -ENOMEM; + + vdev->release = video_device_release; + +If you embed it in a larger struct, then you must set the ``release()`` +callback to your own function: + +.. code-block:: c + + struct video_device *vdev = &my_vdev->vdev; + + vdev->release = my_vdev_release; + +The ``release()`` callback must be set and it is called when the last user +of the video device exits. + +The default :c:func:`video_device_release` callback currently +just calls ``kfree`` to free the allocated memory. + +There is also a :c:func:`video_device_release_empty` function that does +nothing (is empty) and should be used if the struct is embedded and there +is nothing to do when it is released. + +You should also set these fields of :c:type:`video_device`: + +- :c:type:`video_device`->v4l2_dev: must be set to the :c:type:`v4l2_device` + parent device. + +- :c:type:`video_device`->name: set to something descriptive and unique. + +- :c:type:`video_device`->vfl_dir: set this to ``VFL_DIR_RX`` for capture + devices (``VFL_DIR_RX`` has value 0, so this is normally already the + default), set to ``VFL_DIR_TX`` for output devices and ``VFL_DIR_M2M`` for mem2mem (codec) devices. + +- :c:type:`video_device`->fops: set to the :c:type:`v4l2_file_operations` + struct. + +- :c:type:`video_device`->ioctl_ops: if you use the :c:type:`v4l2_ioctl_ops` + to simplify ioctl maintenance (highly recommended to use this and it might + become compulsory in the future!), then set this to your + :c:type:`v4l2_ioctl_ops` struct. The :c:type:`video_device`->vfl_type and + :c:type:`video_device`->vfl_dir fields are used to disable ops that do not + match the type/dir combination. E.g. VBI ops are disabled for non-VBI nodes, + and output ops are disabled for a capture device. This makes it possible to + provide just one :c:type:`v4l2_ioctl_ops` struct for both vbi and + video nodes. + +- :c:type:`video_device`->lock: leave to ``NULL`` if you want to do all the + locking in the driver. Otherwise you give it a pointer to a struct + ``mutex_lock`` and before the :c:type:`video_device`->unlocked_ioctl + file operation is called this lock will be taken by the core and released + afterwards. See the next section for more details. + +- :c:type:`video_device`->queue: a pointer to the struct vb2_queue + associated with this device node. + If queue is not ``NULL``, and queue->lock is not ``NULL``, then queue->lock + is used for the queuing ioctls (``VIDIOC_REQBUFS``, ``CREATE_BUFS``, + ``QBUF``, ``DQBUF``, ``QUERYBUF``, ``PREPARE_BUF``, ``STREAMON`` and + ``STREAMOFF``) instead of the lock above. + That way the :ref:`vb2 <vb2_framework>` queuing framework does not have + to wait for other ioctls. This queue pointer is also used by the + :ref:`vb2 <vb2_framework>` helper functions to check for + queuing ownership (i.e. is the filehandle calling it allowed to do the + operation). + +- :c:type:`video_device`->prio: keeps track of the priorities. Used to + implement ``VIDIOC_G_PRIORITY`` and ``VIDIOC_S_PRIORITY``. + If left to ``NULL``, then it will use the struct v4l2_prio_state + in :c:type:`v4l2_device`. If you want to have a separate priority state per + (group of) device node(s), then you can point it to your own struct + :c:type:`v4l2_prio_state`. + +- :c:type:`video_device`->dev_parent: you only set this if v4l2_device was + registered with ``NULL`` as the parent ``device`` struct. This only happens + in cases where one hardware device has multiple PCI devices that all share + the same :c:type:`v4l2_device` core. + + The cx88 driver is an example of this: one core :c:type:`v4l2_device` struct, + but it is used by both a raw video PCI device (cx8800) and a MPEG PCI device + (cx8802). Since the :c:type:`v4l2_device` cannot be associated with two PCI + devices at the same time it is setup without a parent device. But when the + struct video_device is initialized you **do** know which parent + PCI device to use and so you set ``dev_device`` to the correct PCI device. + +If you use :c:type:`v4l2_ioctl_ops`, then you should set +:c:type:`video_device`->unlocked_ioctl to :c:func:`video_ioctl2` in your +:c:type:`v4l2_file_operations` struct. + +In some cases you want to tell the core that a function you had specified in +your :c:type:`v4l2_ioctl_ops` should be ignored. You can mark such ioctls by +calling this function before :c:func:`video_register_device` is called: + + :c:func:`v4l2_disable_ioctl <v4l2_disable_ioctl>` + (:c:type:`vdev <video_device>`, cmd). + +This tends to be needed if based on external factors (e.g. which card is +being used) you want to turns off certain features in :c:type:`v4l2_ioctl_ops` +without having to make a new struct. + +The :c:type:`v4l2_file_operations` struct is a subset of file_operations. +The main difference is that the inode argument is omitted since it is never +used. + +If integration with the media framework is needed, you must initialize the +:c:type:`media_entity` struct embedded in the :c:type:`video_device` struct +(entity field) by calling :c:func:`media_entity_pads_init`: + +.. code-block:: c + + struct media_pad *pad = &my_vdev->pad; + int err; + + err = media_entity_pads_init(&vdev->entity, 1, pad); + +The pads array must have been previously initialized. There is no need to +manually set the struct media_entity type and name fields. + +A reference to the entity will be automatically acquired/released when the +video device is opened/closed. + +ioctls and locking +------------------ + +The V4L core provides optional locking services. The main service is the +lock field in struct video_device, which is a pointer to a mutex. +If you set this pointer, then that will be used by unlocked_ioctl to +serialize all ioctls. + +If you are using the :ref:`videobuf2 framework <vb2_framework>`, then there +is a second lock that you can set: :c:type:`video_device`->queue->lock. If +set, then this lock will be used instead of :c:type:`video_device`->lock +to serialize all queuing ioctls (see the previous section +for the full list of those ioctls). + +The advantage of using a different lock for the queuing ioctls is that for some +drivers (particularly USB drivers) certain commands such as setting controls +can take a long time, so you want to use a separate lock for the buffer queuing +ioctls. That way your ``VIDIOC_DQBUF`` doesn't stall because the driver is busy +changing the e.g. exposure of the webcam. + +Of course, you can always do all the locking yourself by leaving both lock +pointers at ``NULL``. + +In the case of :ref:`videobuf2 <vb2_framework>` you must set the ``queue->lock`` +pointer to the lock you use to serialize the queuing ioctls. This ensures that +that lock is released while waiting in ``VIDIOC_DQBUF`` for a buffer to arrive, +and it is retaken afterwards. + +The implementation of a hotplug disconnect should also take the lock from +:c:type:`video_device` before calling v4l2_device_disconnect. If you are also +using :c:type:`video_device`->queue->lock, then you have to first lock +:c:type:`video_device`->queue->lock followed by :c:type:`video_device`->lock. +That way you can be sure no ioctl is running when you call +:c:func:`v4l2_device_disconnect`. + +Video device registration +------------------------- + +Next you register the video device with :c:func:`video_register_device`. +This will create the character device for you. + +.. code-block:: c + + err = video_register_device(vdev, VFL_TYPE_VIDEO, -1); + if (err) { + video_device_release(vdev); /* or kfree(my_vdev); */ + return err; + } + +If the :c:type:`v4l2_device` parent device has a not ``NULL`` mdev field, +the video device entity will be automatically registered with the media +device. + +Which device is registered depends on the type argument. The following +types exist: + +========================== ==================== ============================== +:c:type:`vfl_devnode_type` Device name Usage +========================== ==================== ============================== +``VFL_TYPE_VIDEO`` ``/dev/videoX`` for video input/output devices +``VFL_TYPE_VBI`` ``/dev/vbiX`` for vertical blank data (i.e. + closed captions, teletext) +``VFL_TYPE_RADIO`` ``/dev/radioX`` for radio tuners +``VFL_TYPE_SUBDEV`` ``/dev/v4l-subdevX`` for V4L2 subdevices +``VFL_TYPE_SDR`` ``/dev/swradioX`` for Software Defined Radio + (SDR) tuners +``VFL_TYPE_TOUCH`` ``/dev/v4l-touchX`` for touch sensors +========================== ==================== ============================== + +The last argument gives you a certain amount of control over the device +node number used (i.e. the X in ``videoX``). Normally you will pass -1 +to let the v4l2 framework pick the first free number. But sometimes users +want to select a specific node number. It is common that drivers allow +the user to select a specific device node number through a driver module +option. That number is then passed to this function and video_register_device +will attempt to select that device node number. If that number was already +in use, then the next free device node number will be selected and it +will send a warning to the kernel log. + +Another use-case is if a driver creates many devices. In that case it can +be useful to place different video devices in separate ranges. For example, +video capture devices start at 0, video output devices start at 16. +So you can use the last argument to specify a minimum device node number +and the v4l2 framework will try to pick the first free number that is equal +or higher to what you passed. If that fails, then it will just pick the +first free number. + +Since in this case you do not care about a warning about not being able +to select the specified device node number, you can call the function +:c:func:`video_register_device_no_warn` instead. + +Whenever a device node is created some attributes are also created for you. +If you look in ``/sys/class/video4linux`` you see the devices. Go into e.g. +``video0`` and you will see 'name', 'dev_debug' and 'index' attributes. The +'name' attribute is the 'name' field of the video_device struct. The +'dev_debug' attribute can be used to enable core debugging. See the next +section for more detailed information on this. + +The 'index' attribute is the index of the device node: for each call to +:c:func:`video_register_device()` the index is just increased by 1. The +first video device node you register always starts with index 0. + +Users can setup udev rules that utilize the index attribute to make fancy +device names (e.g. '``mpegX``' for MPEG video capture device nodes). + +After the device was successfully registered, then you can use these fields: + +- :c:type:`video_device`->vfl_type: the device type passed to + :c:func:`video_register_device`. +- :c:type:`video_device`->minor: the assigned device minor number. +- :c:type:`video_device`->num: the device node number (i.e. the X in + ``videoX``). +- :c:type:`video_device`->index: the device index number. + +If the registration failed, then you need to call +:c:func:`video_device_release` to free the allocated :c:type:`video_device` +struct, or free your own struct if the :c:type:`video_device` was embedded in +it. The ``vdev->release()`` callback will never be called if the registration +failed, nor should you ever attempt to unregister the device if the +registration failed. + +video device debugging +---------------------- + +The 'dev_debug' attribute that is created for each video, vbi, radio or swradio +device in ``/sys/class/video4linux/<devX>/`` allows you to enable logging of +file operations. + +It is a bitmask and the following bits can be set: + +.. tabularcolumns:: |p{5ex}|L| + +===== ================================================================ +Mask Description +===== ================================================================ +0x01 Log the ioctl name and error code. VIDIOC_(D)QBUF ioctls are + only logged if bit 0x08 is also set. +0x02 Log the ioctl name arguments and error code. VIDIOC_(D)QBUF + ioctls are + only logged if bit 0x08 is also set. +0x04 Log the file operations open, release, read, write, mmap and + get_unmapped_area. The read and write operations are only + logged if bit 0x08 is also set. +0x08 Log the read and write file operations and the VIDIOC_QBUF and + VIDIOC_DQBUF ioctls. +0x10 Log the poll file operation. +0x20 Log error and messages in the control operations. +===== ================================================================ + +Video device cleanup +-------------------- + +When the video device nodes have to be removed, either during the unload +of the driver or because the USB device was disconnected, then you should +unregister them with: + + :c:func:`video_unregister_device` + (:c:type:`vdev <video_device>`); + +This will remove the device nodes from sysfs (causing udev to remove them +from ``/dev``). + +After :c:func:`video_unregister_device` returns no new opens can be done. +However, in the case of USB devices some application might still have one of +these device nodes open. So after the unregister all file operations (except +release, of course) will return an error as well. + +When the last user of the video device node exits, then the ``vdev->release()`` +callback is called and you can do the final cleanup there. + +Don't forget to cleanup the media entity associated with the video device if +it has been initialized: + + :c:func:`media_entity_cleanup <media_entity_cleanup>` + (&vdev->entity); + +This can be done from the release callback. + + +helper functions +---------------- + +There are a few useful helper functions: + +- file and :c:type:`video_device` private data + +You can set/get driver private data in the video_device struct using: + + :c:func:`video_get_drvdata <video_get_drvdata>` + (:c:type:`vdev <video_device>`); + + :c:func:`video_set_drvdata <video_set_drvdata>` + (:c:type:`vdev <video_device>`); + +Note that you can safely call :c:func:`video_set_drvdata` before calling +:c:func:`video_register_device`. + +And this function: + + :c:func:`video_devdata <video_devdata>` + (struct file \*file); + +returns the video_device belonging to the file struct. + +The :c:func:`video_devdata` function combines :c:func:`video_get_drvdata` +with :c:func:`video_devdata`: + + :c:func:`video_drvdata <video_drvdata>` + (struct file \*file); + +You can go from a :c:type:`video_device` struct to the v4l2_device struct using: + +.. code-block:: c + + struct v4l2_device *v4l2_dev = vdev->v4l2_dev; + +- Device node name + +The :c:type:`video_device` node kernel name can be retrieved using: + + :c:func:`video_device_node_name <video_device_node_name>` + (:c:type:`vdev <video_device>`); + +The name is used as a hint by userspace tools such as udev. The function +should be used where possible instead of accessing the video_device::num and +video_device::minor fields. + +video_device functions and data structures +------------------------------------------ + +.. kernel-doc:: include/media/v4l2-dev.h diff --git a/Documentation/driver-api/media/v4l2-device.rst b/Documentation/driver-api/media/v4l2-device.rst new file mode 100644 index 000000000..7bd9c45f5 --- /dev/null +++ b/Documentation/driver-api/media/v4l2-device.rst @@ -0,0 +1,146 @@ +.. SPDX-License-Identifier: GPL-2.0 + +V4L2 device instance +-------------------- + +Each device instance is represented by a struct v4l2_device. +Very simple devices can just allocate this struct, but most of the time you +would embed this struct inside a larger struct. + +You must register the device instance by calling: + + :c:func:`v4l2_device_register <v4l2_device_register>` + (dev, :c:type:`v4l2_dev <v4l2_device>`). + +Registration will initialize the :c:type:`v4l2_device` struct. If the +dev->driver_data field is ``NULL``, it will be linked to +:c:type:`v4l2_dev <v4l2_device>` argument. + +Drivers that want integration with the media device framework need to set +dev->driver_data manually to point to the driver-specific device structure +that embed the struct v4l2_device instance. This is achieved by a +``dev_set_drvdata()`` call before registering the V4L2 device instance. +They must also set the struct v4l2_device mdev field to point to a +properly initialized and registered :c:type:`media_device` instance. + +If :c:type:`v4l2_dev <v4l2_device>`\ ->name is empty then it will be set to a +value derived from dev (driver name followed by the bus_id, to be precise). +If you set it up before calling :c:func:`v4l2_device_register` then it will +be untouched. If dev is ``NULL``, then you **must** setup +:c:type:`v4l2_dev <v4l2_device>`\ ->name before calling +:c:func:`v4l2_device_register`. + +You can use :c:func:`v4l2_device_set_name` to set the name based on a driver +name and a driver-global atomic_t instance. This will generate names like +``ivtv0``, ``ivtv1``, etc. If the name ends with a digit, then it will insert +a dash: ``cx18-0``, ``cx18-1``, etc. This function returns the instance number. + +The first ``dev`` argument is normally the ``struct device`` pointer of a +``pci_dev``, ``usb_interface`` or ``platform_device``. It is rare for dev to +be ``NULL``, but it happens with ISA devices or when one device creates +multiple PCI devices, thus making it impossible to associate +:c:type:`v4l2_dev <v4l2_device>` with a particular parent. + +You can also supply a ``notify()`` callback that can be called by sub-devices +to notify you of events. Whether you need to set this depends on the +sub-device. Any notifications a sub-device supports must be defined in a header +in ``include/media/subdevice.h``. + +V4L2 devices are unregistered by calling: + + :c:func:`v4l2_device_unregister` + (:c:type:`v4l2_dev <v4l2_device>`). + +If the dev->driver_data field points to :c:type:`v4l2_dev <v4l2_device>`, +it will be reset to ``NULL``. Unregistering will also automatically unregister +all subdevs from the device. + +If you have a hotpluggable device (e.g. a USB device), then when a disconnect +happens the parent device becomes invalid. Since :c:type:`v4l2_device` has a +pointer to that parent device it has to be cleared as well to mark that the +parent is gone. To do this call: + + :c:func:`v4l2_device_disconnect` + (:c:type:`v4l2_dev <v4l2_device>`). + +This does *not* unregister the subdevs, so you still need to call the +:c:func:`v4l2_device_unregister` function for that. If your driver is not +hotpluggable, then there is no need to call :c:func:`v4l2_device_disconnect`. + +Sometimes you need to iterate over all devices registered by a specific +driver. This is usually the case if multiple device drivers use the same +hardware. E.g. the ivtvfb driver is a framebuffer driver that uses the ivtv +hardware. The same is true for alsa drivers for example. + +You can iterate over all registered devices as follows: + +.. code-block:: c + + static int callback(struct device *dev, void *p) + { + struct v4l2_device *v4l2_dev = dev_get_drvdata(dev); + + /* test if this device was inited */ + if (v4l2_dev == NULL) + return 0; + ... + return 0; + } + + int iterate(void *p) + { + struct device_driver *drv; + int err; + + /* Find driver 'ivtv' on the PCI bus. + pci_bus_type is a global. For USB buses use usb_bus_type. */ + drv = driver_find("ivtv", &pci_bus_type); + /* iterate over all ivtv device instances */ + err = driver_for_each_device(drv, NULL, p, callback); + put_driver(drv); + return err; + } + +Sometimes you need to keep a running counter of the device instance. This is +commonly used to map a device instance to an index of a module option array. + +The recommended approach is as follows: + +.. code-block:: c + + static atomic_t drv_instance = ATOMIC_INIT(0); + + static int drv_probe(struct pci_dev *pdev, const struct pci_device_id *pci_id) + { + ... + state->instance = atomic_inc_return(&drv_instance) - 1; + } + +If you have multiple device nodes then it can be difficult to know when it is +safe to unregister :c:type:`v4l2_device` for hotpluggable devices. For this +purpose :c:type:`v4l2_device` has refcounting support. The refcount is +increased whenever :c:func:`video_register_device` is called and it is +decreased whenever that device node is released. When the refcount reaches +zero, then the :c:type:`v4l2_device` release() callback is called. You can +do your final cleanup there. + +If other device nodes (e.g. ALSA) are created, then you can increase and +decrease the refcount manually as well by calling: + + :c:func:`v4l2_device_get` + (:c:type:`v4l2_dev <v4l2_device>`). + +or: + + :c:func:`v4l2_device_put` + (:c:type:`v4l2_dev <v4l2_device>`). + +Since the initial refcount is 1 you also need to call +:c:func:`v4l2_device_put` in the ``disconnect()`` callback (for USB devices) +or in the ``remove()`` callback (for e.g. PCI devices), otherwise the refcount +will never reach 0. + +v4l2_device functions and data structures +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +.. kernel-doc:: include/media/v4l2-device.h diff --git a/Documentation/driver-api/media/v4l2-dv-timings.rst b/Documentation/driver-api/media/v4l2-dv-timings.rst new file mode 100644 index 000000000..b178f9315 --- /dev/null +++ b/Documentation/driver-api/media/v4l2-dv-timings.rst @@ -0,0 +1,6 @@ +.. SPDX-License-Identifier: GPL-2.0 + +V4L2 DV Timings functions +^^^^^^^^^^^^^^^^^^^^^^^^^ + +.. kernel-doc:: include/media/v4l2-dv-timings.h diff --git a/Documentation/driver-api/media/v4l2-event.rst b/Documentation/driver-api/media/v4l2-event.rst new file mode 100644 index 000000000..52d4fbc5d --- /dev/null +++ b/Documentation/driver-api/media/v4l2-event.rst @@ -0,0 +1,181 @@ +.. SPDX-License-Identifier: GPL-2.0 + +V4L2 events +----------- + +The V4L2 events provide a generic way to pass events to user space. +The driver must use :c:type:`v4l2_fh` to be able to support V4L2 events. + +Events are subscribed per-filehandle. An event specification consists of a +``type`` and is optionally associated with an object identified through the +``id`` field. If unused, then the ``id`` is 0. So an event is uniquely +identified by the ``(type, id)`` tuple. + +The :c:type:`v4l2_fh` struct has a list of subscribed events on its +``subscribed`` field. + +When the user subscribes to an event, a :c:type:`v4l2_subscribed_event` +struct is added to :c:type:`v4l2_fh`\ ``.subscribed``, one for every +subscribed event. + +Each :c:type:`v4l2_subscribed_event` struct ends with a +:c:type:`v4l2_kevent` ringbuffer, with the size given by the caller +of :c:func:`v4l2_event_subscribe`. This ringbuffer is used to store any events +raised by the driver. + +So every ``(type, ID)`` event tuple will have its own +:c:type:`v4l2_kevent` ringbuffer. This guarantees that if a driver is +generating lots of events of one type in a short time, then that will +not overwrite events of another type. + +But if you get more events of one type than the size of the +:c:type:`v4l2_kevent` ringbuffer, then the oldest event will be dropped +and the new one added. + +The :c:type:`v4l2_kevent` struct links into the ``available`` +list of the :c:type:`v4l2_fh` struct so :ref:`VIDIOC_DQEVENT` will +know which event to dequeue first. + +Finally, if the event subscription is associated with a particular object +such as a V4L2 control, then that object needs to know about that as well +so that an event can be raised by that object. So the ``node`` field can +be used to link the :c:type:`v4l2_subscribed_event` struct into a list of +such objects. + +So to summarize: + +- struct v4l2_fh has two lists: one of the ``subscribed`` events, + and one of the ``available`` events. + +- struct v4l2_subscribed_event has a ringbuffer of raised + (pending) events of that particular type. + +- If struct v4l2_subscribed_event is associated with a specific + object, then that object will have an internal list of + struct v4l2_subscribed_event so it knows who subscribed an + event to that object. + +Furthermore, the internal struct v4l2_subscribed_event has +``merge()`` and ``replace()`` callbacks which drivers can set. These +callbacks are called when a new event is raised and there is no more room. + +The ``replace()`` callback allows you to replace the payload of the old event +with that of the new event, merging any relevant data from the old payload +into the new payload that replaces it. It is called when this event type has +a ringbuffer with size is one, i.e. only one event can be stored in the +ringbuffer. + +The ``merge()`` callback allows you to merge the oldest event payload into +that of the second-oldest event payload. It is called when +the ringbuffer has size is greater than one. + +This way no status information is lost, just the intermediate steps leading +up to that state. + +A good example of these ``replace``/``merge`` callbacks is in v4l2-event.c: +``ctrls_replace()`` and ``ctrls_merge()`` callbacks for the control event. + +.. note:: + these callbacks can be called from interrupt context, so they must + be fast. + +In order to queue events to video device, drivers should call: + + :c:func:`v4l2_event_queue <v4l2_event_queue>` + (:c:type:`vdev <video_device>`, :c:type:`ev <v4l2_event>`) + +The driver's only responsibility is to fill in the type and the data fields. +The other fields will be filled in by V4L2. + +Event subscription +~~~~~~~~~~~~~~~~~~ + +Subscribing to an event is via: + + :c:func:`v4l2_event_subscribe <v4l2_event_subscribe>` + (:c:type:`fh <v4l2_fh>`, :c:type:`sub <v4l2_event_subscription>` , + elems, :c:type:`ops <v4l2_subscribed_event_ops>`) + + +This function is used to implement :c:type:`video_device`-> +:c:type:`ioctl_ops <v4l2_ioctl_ops>`-> ``vidioc_subscribe_event``, +but the driver must check first if the driver is able to produce events +with specified event id, and then should call +:c:func:`v4l2_event_subscribe` to subscribe the event. + +The elems argument is the size of the event queue for this event. If it is 0, +then the framework will fill in a default value (this depends on the event +type). + +The ops argument allows the driver to specify a number of callbacks: + +.. tabularcolumns:: |p{1.5cm}|p{16.0cm}| + +======== ============================================================== +Callback Description +======== ============================================================== +add called when a new listener gets added (subscribing to the same + event twice will only cause this callback to get called once) +del called when a listener stops listening +replace replace event 'old' with event 'new'. +merge merge event 'old' into event 'new'. +======== ============================================================== + +All 4 callbacks are optional, if you don't want to specify any callbacks +the ops argument itself maybe ``NULL``. + +Unsubscribing an event +~~~~~~~~~~~~~~~~~~~~~~ + +Unsubscribing to an event is via: + + :c:func:`v4l2_event_unsubscribe <v4l2_event_unsubscribe>` + (:c:type:`fh <v4l2_fh>`, :c:type:`sub <v4l2_event_subscription>`) + +This function is used to implement :c:type:`video_device`-> +:c:type:`ioctl_ops <v4l2_ioctl_ops>`-> ``vidioc_unsubscribe_event``. +A driver may call :c:func:`v4l2_event_unsubscribe` directly unless it +wants to be involved in unsubscription process. + +The special type ``V4L2_EVENT_ALL`` may be used to unsubscribe all events. The +drivers may want to handle this in a special way. + +Check if there's a pending event +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Checking if there's a pending event is via: + + :c:func:`v4l2_event_pending <v4l2_event_pending>` + (:c:type:`fh <v4l2_fh>`) + + +This function returns the number of pending events. Useful when implementing +poll. + +How events work +~~~~~~~~~~~~~~~ + +Events are delivered to user space through the poll system call. The driver +can use :c:type:`v4l2_fh`->wait (a wait_queue_head_t) as the argument for +``poll_wait()``. + +There are standard and private events. New standard events must use the +smallest available event type. The drivers must allocate their events from +their own class starting from class base. Class base is +``V4L2_EVENT_PRIVATE_START`` + n * 1000 where n is the lowest available number. +The first event type in the class is reserved for future use, so the first +available event type is 'class base + 1'. + +An example on how the V4L2 events may be used can be found in the OMAP +3 ISP driver (``drivers/media/platform/ti/omap3isp``). + +A subdev can directly send an event to the :c:type:`v4l2_device` notify +function with ``V4L2_DEVICE_NOTIFY_EVENT``. This allows the bridge to map +the subdev that sends the event to the video node(s) associated with the +subdev that need to be informed about such an event. + +V4L2 event functions and data structures +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +.. kernel-doc:: include/media/v4l2-event.h + diff --git a/Documentation/driver-api/media/v4l2-fh.rst b/Documentation/driver-api/media/v4l2-fh.rst new file mode 100644 index 000000000..ff1fdd897 --- /dev/null +++ b/Documentation/driver-api/media/v4l2-fh.rst @@ -0,0 +1,136 @@ +.. SPDX-License-Identifier: GPL-2.0 + +V4L2 File handles +----------------- + +struct v4l2_fh provides a way to easily keep file handle specific data that is +used by the V4L2 framework. Its usage is mandatory in all drivers. + +struct v4l2_fh is allocated in the driver's ``open()`` file operation handler. +It is typically embedded in a larger driver-specific structure. The +:c:type:`v4l2_fh` must be initialized with a call to :c:func:`v4l2_fh_init`, +and added to the video device with :c:func:`v4l2_fh_add`. This associates the +:c:type:`v4l2_fh` with the :c:type:`file` by setting ``file->private_data`` to +point to the :c:type:`v4l2_fh`. + +Similarly, the struct v4l2_fh is freed in the driver's ``release()`` file +operation handler. It must be removed from the video device with +:c:func:`v4l2_fh_del` and cleaned up with :c:func:`v4l2_fh_exit` before being +freed. + +Drivers must not access ``file->private_data`` directly. They can retrieve the +:c:type:`v4l2_fh` associated with a :c:type:`file` by calling +:c:func:`file_to_v4l2_fh`. Drivers can extract their own file handle structure +by using the container_of macro. + +Example: + +.. code-block:: c + + struct my_fh { + int blah; + struct v4l2_fh fh; + }; + + ... + + int my_open(struct file *file) + { + struct my_fh *my_fh; + struct video_device *vfd; + int ret; + + ... + + my_fh = kzalloc_obj(*my_fh); + + ... + + v4l2_fh_init(&my_fh->fh, vfd); + + ... + + v4l2_fh_add(&my_fh->fh, file); + return 0; + } + + int my_release(struct file *file) + { + struct v4l2_fh *fh = file_to_v4l2_fh(file); + struct my_fh *my_fh = container_of(fh, struct my_fh, fh); + + ... + v4l2_fh_del(&my_fh->fh, file); + v4l2_fh_exit(&my_fh->fh); + kfree(my_fh); + return 0; + } + +Below is a short description of the :c:type:`v4l2_fh` functions used: + +:c:func:`v4l2_fh_init <v4l2_fh_init>` +(:c:type:`fh <v4l2_fh>`, :c:type:`vdev <video_device>`) + +- Initialise the file handle. This **MUST** be performed in the driver's + :c:type:`v4l2_file_operations`->open() handler. + +:c:func:`v4l2_fh_add <v4l2_fh_add>` +(:c:type:`fh <v4l2_fh>`, struct file \*filp) + +- Add a :c:type:`v4l2_fh` to :c:type:`video_device` file handle list. + Must be called once the file handle is completely initialized. + +:c:func:`v4l2_fh_del <v4l2_fh_del>` +(:c:type:`fh <v4l2_fh>`, struct file \*filp) + +- Unassociate the file handle from :c:type:`video_device`. The file handle + exit function may now be called. + +:c:func:`v4l2_fh_exit <v4l2_fh_exit>` +(:c:type:`fh <v4l2_fh>`) + +- Uninitialise the file handle. After uninitialisation the :c:type:`v4l2_fh` + memory can be freed. + +:c:func:`file_to_v4l2_fh <file_to_v4l2_fh>` +(struct file \*filp) + +- Retrieve the :c:type:`v4l2_fh` instance associated with a :c:type:`file`. + +If struct v4l2_fh is not embedded, then you can use these helper functions: + +:c:func:`v4l2_fh_open <v4l2_fh_open>` +(struct file \*filp) + +- This allocates a struct v4l2_fh, initializes it and adds it to + the struct video_device associated with the file struct. + +:c:func:`v4l2_fh_release <v4l2_fh_release>` +(struct file \*filp) + +- This deletes it from the struct video_device associated with the + file struct, uninitialised the :c:type:`v4l2_fh` and frees it. + +These two functions can be plugged into the v4l2_file_operation's ``open()`` +and ``release()`` ops. + +Several drivers need to do something when the first file handle is opened and +when the last file handle closes. Two helper functions were added to check +whether the :c:type:`v4l2_fh` struct is the only open filehandle of the +associated device node: + +:c:func:`v4l2_fh_is_singular <v4l2_fh_is_singular>` +(:c:type:`fh <v4l2_fh>`) + +- Returns 1 if the file handle is the only open file handle, else 0. + +:c:func:`v4l2_fh_is_singular_file <v4l2_fh_is_singular_file>` +(struct file \*filp) + +- Same, but it calls v4l2_fh_is_singular with filp->private_data. + + +V4L2 fh functions and data structures +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +.. kernel-doc:: include/media/v4l2-fh.h diff --git a/Documentation/driver-api/media/v4l2-flash-led-class.rst b/Documentation/driver-api/media/v4l2-flash-led-class.rst new file mode 100644 index 000000000..2aa6bed9b --- /dev/null +++ b/Documentation/driver-api/media/v4l2-flash-led-class.rst @@ -0,0 +1,6 @@ +.. SPDX-License-Identifier: GPL-2.0 + +V4L2 flash functions and data structures +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +.. kernel-doc:: include/media/v4l2-flash-led-class.h diff --git a/Documentation/driver-api/media/v4l2-fwnode.rst b/Documentation/driver-api/media/v4l2-fwnode.rst new file mode 100644 index 000000000..e313b6cdd --- /dev/null +++ b/Documentation/driver-api/media/v4l2-fwnode.rst @@ -0,0 +1,5 @@ +.. SPDX-License-Identifier: GPL-2.0 + +V4L2 fwnode kAPI +^^^^^^^^^^^^^^^^ +.. kernel-doc:: include/media/v4l2-fwnode.h diff --git a/Documentation/driver-api/media/v4l2-intro.rst b/Documentation/driver-api/media/v4l2-intro.rst new file mode 100644 index 000000000..4d54fa9d7 --- /dev/null +++ b/Documentation/driver-api/media/v4l2-intro.rst @@ -0,0 +1,76 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Introduction +------------ + +The V4L2 drivers tend to be very complex due to the complexity of the +hardware: most devices have multiple ICs, export multiple device nodes in +/dev, and create also non-V4L2 devices such as DVB, ALSA, FB, I2C and input +(IR) devices. + +Especially the fact that V4L2 drivers have to setup supporting ICs to +do audio/video muxing/encoding/decoding makes it more complex than most. +Usually these ICs are connected to the main bridge driver through one or +more I2C buses, but other buses can also be used. Such devices are +called 'sub-devices'. + +For a long time the framework was limited to the video_device struct for +creating V4L device nodes and video_buf for handling the video buffers +(note that this document does not discuss the video_buf framework). + +This meant that all drivers had to do the setup of device instances and +connecting to sub-devices themselves. Some of this is quite complicated +to do right and many drivers never did do it correctly. + +There is also a lot of common code that could never be refactored due to +the lack of a framework. + +So this framework sets up the basic building blocks that all drivers +need and this same framework should make it much easier to refactor +common code into utility functions shared by all drivers. + +A good example to look at as a reference is the v4l2-pci-skeleton.c +source that is available in samples/v4l/. It is a skeleton driver for +a PCI capture card, and demonstrates how to use the V4L2 driver +framework. It can be used as a template for real PCI video capture driver. + +Structure of a V4L driver +------------------------- + +All drivers have the following structure: + +1) A struct for each device instance containing the device state. + +2) A way of initializing and commanding sub-devices (if any). + +3) Creating V4L2 device nodes (/dev/videoX, /dev/vbiX and /dev/radioX) + and keeping track of device-node specific data. + +4) Filehandle-specific structs containing per-filehandle data; + +5) video buffer handling. + +This is a rough schematic of how it all relates: + +.. code-block:: none + + device instances + | + +-sub-device instances + | + \-V4L2 device nodes + | + \-filehandle instances + + +Structure of the V4L2 framework +------------------------------- + +The framework closely resembles the driver structure: it has a v4l2_device +struct for the device instance data, a v4l2_subdev struct to refer to +sub-device instances, the video_device struct stores V4L2 device node data +and the v4l2_fh struct keeps track of filehandle instances. + +The V4L2 framework also optionally integrates with the media framework. If a +driver sets the struct v4l2_device mdev field, sub-devices and video nodes +will automatically appear in the media framework as entities. diff --git a/Documentation/driver-api/media/v4l2-isp.rst b/Documentation/driver-api/media/v4l2-isp.rst new file mode 100644 index 000000000..618ae614f --- /dev/null +++ b/Documentation/driver-api/media/v4l2-isp.rst @@ -0,0 +1,49 @@ +.. SPDX-License-Identifier: GPL-2.0 + +V4L2 generic ISP parameters and statistics support +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Design rationale +================ + +ISP configuration parameters and statistics are processed and collected by +drivers and exchanged with userspace through data types that usually +reflect the ISP peripheral registers layout. + +Each ISP driver defines its own metadata output format for parameters and +a metadata capture format for statistics. The buffer layout is realized by a +set of C structures that reflects the registers layout. The number and types +of C structures is fixed by the format definition and becomes part of the Linux +kernel uAPI/uABI interface. + +Because of the hard requirement of backward compatibility when extending the +user API/ABI interface, modifying an ISP driver capture or output metadata +format after it has been accepted by mainline is very hard if not impossible. + +It generally happens, in fact, that after the first accepted revision of an ISP +driver the buffers layout need to be modified, either to support new hardware +blocks, to fix bugs or to support different revisions of the hardware. + +Each of these situations would require defining a new metadata format, making it +really hard to maintain and extend drivers and requiring userspace to use +the correct format depending on the kernel revision in use. + +V4L2 ISP configuration parameters +================================= + +For these reasons, Video4Linux2 defines generic types for ISP configuration +parameters and statistics. Drivers are still expected to define their own +formats for their metadata output and capture nodes, but the buffers layout can +be defined using the extensible and versioned types defined by +include/uapi/linux/media/v4l2-isp.h. + +Drivers are expected to provide the definitions of their supported ISP blocks +and the expected maximum size of a buffer. + +For driver developers a set of helper functions to assist them with validation +of the buffer received from userspace is available in +drivers/media/v4l2-core/v4l2-isp.c + +V4L2 ISP support driver documentation +===================================== +.. kernel-doc:: include/media/v4l2-isp.h diff --git a/Documentation/driver-api/media/v4l2-jpeg.rst b/Documentation/driver-api/media/v4l2-jpeg.rst new file mode 100644 index 000000000..af3bc52f8 --- /dev/null +++ b/Documentation/driver-api/media/v4l2-jpeg.rst @@ -0,0 +1,10 @@ +.. SPDX-License-Identifier: GPL-2.0 + +V4L2 JPEG header related functions and data structures +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +.. kernel-doc:: include/media/v4l2-jpeg.h + :internal: + +.. kernel-doc:: drivers/media/v4l2-core/v4l2-jpeg.c + :export: diff --git a/Documentation/driver-api/media/v4l2-mc.rst b/Documentation/driver-api/media/v4l2-mc.rst new file mode 100644 index 000000000..0c352ac58 --- /dev/null +++ b/Documentation/driver-api/media/v4l2-mc.rst @@ -0,0 +1,6 @@ +.. SPDX-License-Identifier: GPL-2.0 + +V4L2 Media Controller functions and data structures +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +.. kernel-doc:: include/media/v4l2-mc.h diff --git a/Documentation/driver-api/media/v4l2-mediabus.rst b/Documentation/driver-api/media/v4l2-mediabus.rst new file mode 100644 index 000000000..1f2254cba --- /dev/null +++ b/Documentation/driver-api/media/v4l2-mediabus.rst @@ -0,0 +1,6 @@ +.. SPDX-License-Identifier: GPL-2.0 + +V4L2 Media Bus functions and data structures +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +.. kernel-doc:: include/media/v4l2-mediabus.h diff --git a/Documentation/driver-api/media/v4l2-mem2mem.rst b/Documentation/driver-api/media/v4l2-mem2mem.rst new file mode 100644 index 000000000..a43b31cc8 --- /dev/null +++ b/Documentation/driver-api/media/v4l2-mem2mem.rst @@ -0,0 +1,6 @@ +.. SPDX-License-Identifier: GPL-2.0 + +V4L2 Memory to Memory functions and data structures +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +.. kernel-doc:: include/media/v4l2-mem2mem.h diff --git a/Documentation/driver-api/media/v4l2-rect.rst b/Documentation/driver-api/media/v4l2-rect.rst new file mode 100644 index 000000000..fc315cd84 --- /dev/null +++ b/Documentation/driver-api/media/v4l2-rect.rst @@ -0,0 +1,6 @@ +.. SPDX-License-Identifier: GPL-2.0 + +V4L2 rect helper functions +^^^^^^^^^^^^^^^^^^^^^^^^^^ + +.. kernel-doc:: include/media/v4l2-rect.h diff --git a/Documentation/driver-api/media/v4l2-subdev.rst b/Documentation/driver-api/media/v4l2-subdev.rst new file mode 100644 index 000000000..13aec460e --- /dev/null +++ b/Documentation/driver-api/media/v4l2-subdev.rst @@ -0,0 +1,644 @@ +.. SPDX-License-Identifier: GPL-2.0 + +V4L2 sub-devices +---------------- + +Many drivers need to communicate with sub-devices. These devices can do all +sort of tasks, but most commonly they handle audio and/or video muxing, +encoding or decoding. For webcams common sub-devices are sensors and camera +controllers. + +Usually these are I2C devices, but not necessarily. In order to provide the +driver with a consistent interface to these sub-devices the +:c:type:`v4l2_subdev` struct (v4l2-subdev.h) was created. + +Each sub-device driver must have a :c:type:`v4l2_subdev` struct. This struct +can be stand-alone for simple sub-devices or it might be embedded in a larger +struct if more state information needs to be stored. Usually there is a +low-level device struct (e.g. ``i2c_client``) that contains the device data as +setup by the kernel. It is recommended to store that pointer in the private +data of :c:type:`v4l2_subdev` using :c:func:`v4l2_set_subdevdata`. That makes +it easy to go from a :c:type:`v4l2_subdev` to the actual low-level bus-specific +device data. + +You also need a way to go from the low-level struct to :c:type:`v4l2_subdev`. +For the common i2c_client struct the i2c_set_clientdata() call is used to store +a :c:type:`v4l2_subdev` pointer, for other buses you may have to use other +methods. + +Bridges might also need to store per-subdev private data, such as a pointer to +bridge-specific per-subdev private data. The :c:type:`v4l2_subdev` structure +provides host private data for that purpose that can be accessed with +:c:func:`v4l2_get_subdev_hostdata` and :c:func:`v4l2_set_subdev_hostdata`. + +From the bridge driver perspective, you load the sub-device module and somehow +obtain the :c:type:`v4l2_subdev` pointer. For i2c devices this is easy: you call +``i2c_get_clientdata()``. For other buses something similar needs to be done. +Helper functions exist for sub-devices on an I2C bus that do most of this +tricky work for you. + +Each :c:type:`v4l2_subdev` contains function pointers that sub-device drivers +can implement (or leave ``NULL`` if it is not applicable). Since sub-devices can +do so many different things and you do not want to end up with a huge ops struct +of which only a handful of ops are commonly implemented, the function pointers +are sorted according to category and each category has its own ops struct. + +The top-level ops struct contains pointers to the category ops structs, which +may be NULL if the subdev driver does not support anything from that category. + +It looks like this: + +.. code-block:: c + + struct v4l2_subdev_core_ops { + int (*log_status)(struct v4l2_subdev *sd); + int (*init)(struct v4l2_subdev *sd, u32 val); + ... + }; + + struct v4l2_subdev_tuner_ops { + ... + }; + + struct v4l2_subdev_audio_ops { + ... + }; + + struct v4l2_subdev_video_ops { + ... + }; + + struct v4l2_subdev_pad_ops { + ... + }; + + struct v4l2_subdev_ops { + const struct v4l2_subdev_core_ops *core; + const struct v4l2_subdev_tuner_ops *tuner; + const struct v4l2_subdev_audio_ops *audio; + const struct v4l2_subdev_video_ops *video; + const struct v4l2_subdev_pad_ops *video; + }; + +The core ops are common to all subdevs, the other categories are implemented +depending on the sub-device. E.g. a video device is unlikely to support the +audio ops and vice versa. + +This setup limits the number of function pointers while still making it easy +to add new ops and categories. + +A sub-device driver initializes the :c:type:`v4l2_subdev` struct using: + + :c:func:`v4l2_subdev_init <v4l2_subdev_init>` + (:c:type:`sd <v4l2_subdev>`, &\ :c:type:`ops <v4l2_subdev_ops>`). + + +Afterwards you need to initialize :c:type:`sd <v4l2_subdev>`->name with a +unique name and set the module owner. This is done for you if you use the +i2c helper functions. + +If integration with the media framework is needed, you must initialize the +:c:type:`media_entity` struct embedded in the :c:type:`v4l2_subdev` struct +(entity field) by calling :c:func:`media_entity_pads_init`, if the entity has +pads: + +.. code-block:: c + + struct media_pad *pads = &my_sd->pads; + int err; + + err = media_entity_pads_init(&sd->entity, npads, pads); + +The pads array must have been previously initialized. There is no need to +manually set the struct media_entity function and name fields, but the +revision field must be initialized if needed. + +A reference to the entity will be automatically acquired/released when the +subdev device node (if any) is opened/closed. + +Don't forget to cleanup the media entity before the sub-device is destroyed: + +.. code-block:: c + + media_entity_cleanup(&sd->entity); + +If a sub-device driver implements sink pads, the subdev driver may set the +link_validate field in :c:type:`v4l2_subdev_pad_ops` to provide its own link +validation function. For every link in the pipeline, the link_validate pad +operation of the sink end of the link is called. In both cases the driver is +still responsible for validating the correctness of the format configuration +between sub-devices and video nodes. + +If link_validate op is not set, the default function +:c:func:`v4l2_subdev_link_validate_default` is used instead. This function +ensures that width, height and the media bus pixel code are equal on both source +and sink of the link. Subdev drivers are also free to use this function to +perform the checks mentioned above in addition to their own checks. + +Subdev registration +~~~~~~~~~~~~~~~~~~~ + +There are currently two ways to register subdevices with the V4L2 core. The +first (traditional) possibility is to have subdevices registered by bridge +drivers. This can be done when the bridge driver has the complete information +about subdevices connected to it and knows exactly when to register them. This +is typically the case for internal subdevices, like video data processing units +within SoCs or complex PCI(e) boards, camera sensors in USB cameras or connected +to SoCs, which pass information about them to bridge drivers, usually in their +platform data. + +There are however also situations where subdevices have to be registered +asynchronously to bridge devices. An example of such a configuration is a Device +Tree based system where information about subdevices is made available to the +system independently from the bridge devices, e.g. when subdevices are defined +in DT as I2C device nodes. The API used in this second case is described further +below. + +Using one or the other registration method only affects the probing process, the +run-time bridge-subdevice interaction is in both cases the same. + +Registering synchronous sub-devices +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +In the **synchronous** case a device (bridge) driver needs to register the +:c:type:`v4l2_subdev` with the v4l2_device: + + :c:func:`v4l2_device_register_subdev <v4l2_device_register_subdev>` + (:c:type:`v4l2_dev <v4l2_device>`, :c:type:`sd <v4l2_subdev>`). + +This can fail if the subdev module disappeared before it could be registered. +After this function was called successfully the subdev->dev field points to +the :c:type:`v4l2_device`. + +If the v4l2_device parent device has a non-NULL mdev field, the sub-device +entity will be automatically registered with the media device. + +You can unregister a sub-device using: + + :c:func:`v4l2_device_unregister_subdev <v4l2_device_unregister_subdev>` + (:c:type:`sd <v4l2_subdev>`). + +Afterwards the subdev module can be unloaded and +:c:type:`sd <v4l2_subdev>`->dev == ``NULL``. + +.. _media-registering-async-subdevs: + +Registering asynchronous sub-devices +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +In the **asynchronous** case subdevice probing can be invoked independently of +the bridge driver availability. The subdevice driver then has to verify whether +all the requirements for a successful probing are satisfied. This can include a +check for a master clock availability. If any of the conditions aren't satisfied +the driver might decide to return ``-EPROBE_DEFER`` to request further reprobing +attempts. Once all conditions are met the subdevice shall be registered using +the :c:func:`v4l2_async_register_subdev` function. Unregistration is +performed using the :c:func:`v4l2_async_unregister_subdev` call. Subdevices +registered this way are stored in a global list of subdevices, ready to be +picked up by bridge drivers. + +Drivers must complete all initialization of the sub-device before +registering it using :c:func:`v4l2_async_register_subdev`, including +enabling runtime PM. This is because the sub-device becomes accessible +as soon as it gets registered. + +Asynchronous sub-device notifiers +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Bridge drivers in turn have to register a notifier object. This is performed +using the :c:func:`v4l2_async_nf_register` call. To unregister the notifier the +driver has to call :c:func:`v4l2_async_nf_unregister`. Before releasing memory +of an unregister notifier, it must be cleaned up by calling +:c:func:`v4l2_async_nf_cleanup`. + +Before registering the notifier, bridge drivers must do two things: first, the +notifier must be initialized using the :c:func:`v4l2_async_nf_init`. Second, +bridge drivers can then begin to form a list of async connection descriptors +that the bridge device needs for its +operation. :c:func:`v4l2_async_nf_add_fwnode`, +:c:func:`v4l2_async_nf_add_fwnode_remote` and :c:func:`v4l2_async_nf_add_i2c` + +Async connection descriptors describe connections to external sub-devices the +drivers for which are not yet probed. Based on an async connection, a media data +or ancillary link may be created when the related sub-device becomes +available. There may be one or more async connections to a given sub-device but +this is not known at the time of adding the connections to the notifier. Async +connections are bound as matching async sub-devices are found, one by one. + +Asynchronous sub-device notifier for sub-devices +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +A driver that registers an asynchronous sub-device may also register an +asynchronous notifier. This is called an asynchronous sub-device notifier and the +process is similar to that of a bridge driver apart from that the notifier is +initialised using :c:func:`v4l2_async_subdev_nf_init` instead. A sub-device +notifier may complete only after the V4L2 device becomes available, i.e. there's +a path via async sub-devices and notifiers to a notifier that is not an +asynchronous sub-device notifier. + +Asynchronous sub-device registration helper for camera sensor drivers +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +:c:func:`v4l2_async_register_subdev_sensor` is a helper function for sensor +drivers registering their own async connection, but it also registers a notifier +and further registers async connections for lens and flash devices found in +firmware. The notifier for the sub-device is unregistered and cleaned up with +the async sub-device, using :c:func:`v4l2_async_unregister_subdev`. + +Asynchronous sub-device notifier example +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +These functions allocate an async connection descriptor which is of type struct +:c:type:`v4l2_async_connection` embedded in a driver-specific struct. The &struct +:c:type:`v4l2_async_connection` shall be the first member of this struct: + +.. code-block:: c + + struct my_async_connection { + struct v4l2_async_connection asc; + ... + }; + + struct my_async_connection *my_asc; + struct fwnode_handle *ep; + + ... + + my_asc = v4l2_async_nf_add_fwnode_remote(¬ifier, ep, + struct my_async_connection); + fwnode_handle_put(ep); + + if (IS_ERR(my_asc)) + return PTR_ERR(my_asc); + +Asynchronous sub-device notifier callbacks +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The V4L2 core will then use these connection descriptors to match asynchronously +registered subdevices to them. If a match is detected the ``.bound()`` notifier +callback is called. After all connections have been bound the .complete() +callback is called. When a connection is removed from the system the +``.unbind()`` method is called. All three callbacks are optional. + +Drivers can store any type of custom data in their driver-specific +:c:type:`v4l2_async_connection` wrapper. If any of that data requires special +handling when the structure is freed, drivers must implement the ``.destroy()`` +notifier callback. The framework will call it right before freeing the +:c:type:`v4l2_async_connection`. + +Calling subdev operations +~~~~~~~~~~~~~~~~~~~~~~~~~ + +The advantage of using :c:type:`v4l2_subdev` is that it is a generic struct and +does not contain any knowledge about the underlying hardware. So a driver might +contain several subdevs that use an I2C bus, but also a subdev that is +controlled through GPIO pins. This distinction is only relevant when setting +up the device, but once the subdev is registered it is completely transparent. + +Once the subdev has been registered you can call an ops function either +directly: + +.. code-block:: c + + err = sd->ops->core->g_std(sd, &norm); + +but it is better and easier to use this macro: + +.. code-block:: c + + err = v4l2_subdev_call(sd, core, g_std, &norm); + +The macro will do the right ``NULL`` pointer checks and returns ``-ENODEV`` +if :c:type:`sd <v4l2_subdev>` is ``NULL``, ``-ENOIOCTLCMD`` if either +:c:type:`sd <v4l2_subdev>`->core or :c:type:`sd <v4l2_subdev>`->core->g_std is ``NULL``, or the actual result of the +:c:type:`sd <v4l2_subdev>`->ops->core->g_std ops. + +It is also possible to call all or a subset of the sub-devices: + +.. code-block:: c + + v4l2_device_call_all(v4l2_dev, 0, core, g_std, &norm); + +Any subdev that does not support this ops is skipped and error results are +ignored. If you want to check for errors use this: + +.. code-block:: c + + err = v4l2_device_call_until_err(v4l2_dev, 0, core, g_std, &norm); + +Any error except ``-ENOIOCTLCMD`` will exit the loop with that error. If no +errors (except ``-ENOIOCTLCMD``) occurred, then 0 is returned. + +The second argument to both calls is a group ID. If 0, then all subdevs are +called. If non-zero, then only those whose group ID match that value will +be called. Before a bridge driver registers a subdev it can set +:c:type:`sd <v4l2_subdev>`->grp_id to whatever value it wants (it's 0 by +default). This value is owned by the bridge driver and the sub-device driver +will never modify or use it. + +The group ID gives the bridge driver more control how callbacks are called. +For example, there may be multiple audio chips on a board, each capable of +changing the volume. But usually only one will actually be used when the +user want to change the volume. You can set the group ID for that subdev to +e.g. AUDIO_CONTROLLER and specify that as the group ID value when calling +``v4l2_device_call_all()``. That ensures that it will only go to the subdev +that needs it. + +If the sub-device needs to notify its v4l2_device parent of an event, then +it can call ``v4l2_subdev_notify(sd, notification, arg)``. This macro checks +whether there is a ``notify()`` callback defined and returns ``-ENODEV`` if not. +Otherwise the result of the ``notify()`` call is returned. + +V4L2 sub-device userspace API +----------------------------- + +Bridge drivers traditionally expose one or multiple video nodes to userspace, +and control subdevices through the :c:type:`v4l2_subdev_ops` operations in +response to video node operations. This hides the complexity of the underlying +hardware from applications. For complex devices, finer-grained control of the +device than what the video nodes offer may be required. In those cases, bridge +drivers that implement :ref:`the media controller API <media_controller>` may +opt for making the subdevice operations directly accessible from userspace. + +Device nodes named ``v4l-subdev``\ *X* can be created in ``/dev`` to access +sub-devices directly. If a sub-device supports direct userspace configuration +it must set the ``V4L2_SUBDEV_FL_HAS_DEVNODE`` flag before being registered. + +After registering sub-devices, the :c:type:`v4l2_device` driver can create +device nodes for all registered sub-devices marked with +``V4L2_SUBDEV_FL_HAS_DEVNODE`` by calling +:c:func:`v4l2_device_register_subdev_nodes`. Those device nodes will be +automatically removed when sub-devices are unregistered. + +The device node handles a subset of the V4L2 API. + +``VIDIOC_QUERYCTRL``, +``VIDIOC_QUERYMENU``, +``VIDIOC_G_CTRL``, +``VIDIOC_S_CTRL``, +``VIDIOC_G_EXT_CTRLS``, +``VIDIOC_S_EXT_CTRLS`` and +``VIDIOC_TRY_EXT_CTRLS``: + + The controls ioctls are identical to the ones defined in V4L2. They + behave identically, with the only exception that they deal only with + controls implemented in the sub-device. Depending on the driver, those + controls can be also be accessed through one (or several) V4L2 device + nodes. + +``VIDIOC_DQEVENT``, +``VIDIOC_SUBSCRIBE_EVENT`` and +``VIDIOC_UNSUBSCRIBE_EVENT`` + + The events ioctls are identical to the ones defined in V4L2. They + behave identically, with the only exception that they deal only with + events generated by the sub-device. Depending on the driver, those + events can also be reported by one (or several) V4L2 device nodes. + + Sub-device drivers that want to use events need to set the + ``V4L2_SUBDEV_FL_HAS_EVENTS`` :c:type:`v4l2_subdev`.flags before registering + the sub-device. After registration events can be queued as usual on the + :c:type:`v4l2_subdev`.devnode device node. + + To properly support events, the ``poll()`` file operation is also + implemented. + +Private ioctls + + All ioctls not in the above list are passed directly to the sub-device + driver through the core::ioctl operation. + +Read-only sub-device userspace API +---------------------------------- + +Bridge drivers that control their connected subdevices through direct calls to +the kernel API realized by :c:type:`v4l2_subdev_ops` structure do not usually +want userspace to be able to change the same parameters through the subdevice +device node and thus do not usually register any. + +It is sometimes useful to report to userspace the current subdevice +configuration through a read-only API, that does not permit applications to +change to the device parameters but allows interfacing to the subdevice device +node to inspect them. + +For instance, to implement cameras based on computational photography, userspace +needs to know the detailed camera sensor configuration (in terms of skipping, +binning, cropping and scaling) for each supported output resolution. To support +such use cases, bridge drivers may expose the subdevice operations to userspace +through a read-only API. + +To create a read-only device node for all the subdevices registered with the +``V4L2_SUBDEV_FL_HAS_DEVNODE`` set, the :c:type:`v4l2_device` driver should call +:c:func:`v4l2_device_register_ro_subdev_nodes`. + +Access to the following ioctls for userspace applications is restricted on +sub-device device nodes registered with +:c:func:`v4l2_device_register_ro_subdev_nodes`. + +``VIDIOC_SUBDEV_S_FMT``, +``VIDIOC_SUBDEV_S_CROP``, +``VIDIOC_SUBDEV_S_SELECTION``: + + These ioctls are only allowed on a read-only subdevice device node + for the :ref:`V4L2_SUBDEV_FORMAT_TRY <v4l2-subdev-format-whence>` + formats and selection rectangles. + +``VIDIOC_SUBDEV_S_FRAME_INTERVAL``, +``VIDIOC_SUBDEV_S_DV_TIMINGS``, +``VIDIOC_SUBDEV_S_STD``: + + These ioctls are not allowed on a read-only subdevice node. + +In case the ioctl is not allowed, or the format to modify is set to +``V4L2_SUBDEV_FORMAT_ACTIVE``, the core returns a negative error code and +the errno variable is set to ``-EPERM``. + +I2C sub-device drivers +---------------------- + +Since these drivers are so common, special helper functions are available to +ease the use of these drivers (``v4l2-common.h``). + +The recommended method of adding :c:type:`v4l2_subdev` support to an I2C driver +is to embed the :c:type:`v4l2_subdev` struct into the state struct that is +created for each I2C device instance. Very simple devices have no state +struct and in that case you can just create a :c:type:`v4l2_subdev` directly. + +A typical state struct would look like this (where 'chipname' is replaced by +the name of the chip): + +.. code-block:: c + + struct chipname_state { + struct v4l2_subdev sd; + ... /* additional state fields */ + }; + +Initialize the :c:type:`v4l2_subdev` struct as follows: + +.. code-block:: c + + v4l2_i2c_subdev_init(&state->sd, client, subdev_ops); + +This function will fill in all the fields of :c:type:`v4l2_subdev` ensure that +the :c:type:`v4l2_subdev` and i2c_client both point to one another. + +You should also add a helper inline function to go from a :c:type:`v4l2_subdev` +pointer to a chipname_state struct: + +.. code-block:: c + + static inline struct chipname_state *to_state(struct v4l2_subdev *sd) + { + return container_of(sd, struct chipname_state, sd); + } + +Use this to go from the :c:type:`v4l2_subdev` struct to the ``i2c_client`` +struct: + +.. code-block:: c + + struct i2c_client *client = v4l2_get_subdevdata(sd); + +And this to go from an ``i2c_client`` to a :c:type:`v4l2_subdev` struct: + +.. code-block:: c + + struct v4l2_subdev *sd = i2c_get_clientdata(client); + +Make sure to call +:c:func:`v4l2_device_unregister_subdev`\ (:c:type:`sd <v4l2_subdev>`) +when the ``remove()`` callback is called. This will unregister the sub-device +from the bridge driver. It is safe to call this even if the sub-device was +never registered. + +You need to do this because when the bridge driver destroys the i2c adapter +the ``remove()`` callbacks are called of the i2c devices on that adapter. +After that the corresponding v4l2_subdev structures are invalid, so they +have to be unregistered first. Calling +:c:func:`v4l2_device_unregister_subdev`\ (:c:type:`sd <v4l2_subdev>`) +from the ``remove()`` callback ensures that this is always done correctly. + + +The bridge driver also has some helper functions it can use: + +.. code-block:: c + + struct v4l2_subdev *sd = v4l2_i2c_new_subdev(v4l2_dev, adapter, + "module_foo", "chipid", 0x36, NULL); + +This loads the given module (can be ``NULL`` if no module needs to be loaded) +and calls :c:func:`i2c_new_client_device` with the given ``i2c_adapter`` and +chip/address arguments. If all goes well, then it registers the subdev with +the v4l2_device. + +You can also use the last argument of :c:func:`v4l2_i2c_new_subdev` to pass +an array of possible I2C addresses that it should probe. These probe addresses +are only used if the previous argument is 0. A non-zero argument means that you +know the exact i2c address so in that case no probing will take place. + +Both functions return ``NULL`` if something went wrong. + +Note that the chipid you pass to :c:func:`v4l2_i2c_new_subdev` is usually +the same as the module name. It allows you to specify a chip variant, e.g. +"saa7114" or "saa7115". In general though the i2c driver autodetects this. +The use of chipid is something that needs to be looked at more closely at a +later date. It differs between i2c drivers and as such can be confusing. +To see which chip variants are supported you can look in the i2c driver code +for the i2c_device_id table. This lists all the possibilities. + +There are one more helper function: + +:c:func:`v4l2_i2c_new_subdev_board` uses an :c:type:`i2c_board_info` struct +which is passed to the i2c driver and replaces the irq, platform_data and addr +arguments. + +If the subdev supports the s_config core ops, then that op is called with +the irq and platform_data arguments after the subdev was setup. + +The :c:func:`v4l2_i2c_new_subdev` function will call +:c:func:`v4l2_i2c_new_subdev_board`, internally filling a +:c:type:`i2c_board_info` structure using the ``client_type`` and the +``addr`` to fill it. + +Centrally managed subdev active state +------------------------------------- + +Traditionally V4L2 subdev drivers maintained internal state for the active +device configuration. This is often implemented as e.g. an array of struct +v4l2_mbus_framefmt, one entry for each pad, and similarly for crop and compose +rectangles. + +In addition to the active configuration, each subdev file handle has a struct +v4l2_subdev_state, managed by the V4L2 core, which contains the try +configuration. + +To simplify the subdev drivers the V4L2 subdev API now optionally supports a +centrally managed active configuration represented by +:c:type:`v4l2_subdev_state`. One instance of state, which contains the active +device configuration, is stored in the sub-device itself as part of +the :c:type:`v4l2_subdev` structure, while the core associates a try state to +each open file handle, to store the try configuration related to that file +handle. + +Sub-device drivers can opt-in and use state to manage their active configuration +by initializing the subdevice state with a call to v4l2_subdev_init_finalize() +before registering the sub-device. They must also call v4l2_subdev_cleanup() +to release all the allocated resources before unregistering the sub-device. +The core automatically allocates and initializes a state for each open file +handle to store the try configurations and frees it when closing the file +handle. + +V4L2 sub-device operations that use both the :ref:`ACTIVE and TRY formats +<v4l2-subdev-format-whence>` receive the correct state to operate on through +the 'state' parameter. The state must be locked and unlocked by the +caller by calling :c:func:`v4l2_subdev_lock_state()` and +:c:func:`v4l2_subdev_unlock_state()`. The caller can do so by calling the subdev +operation through the :c:func:`v4l2_subdev_call_state_active()` macro. + +Operations that do not receive a state parameter implicitly operate on the +subdevice active state, which drivers can exclusively access by +calling :c:func:`v4l2_subdev_lock_and_get_active_state()`. The sub-device active +state must equally be released by calling :c:func:`v4l2_subdev_unlock_state()`. + +Drivers must never manually access the state stored in the :c:type:`v4l2_subdev` +or in the file handle without going through the designated helpers. + +While the V4L2 core passes the correct try or active state to the subdevice +operations, many existing device drivers pass a NULL state when calling +operations with :c:func:`v4l2_subdev_call()`. This legacy construct causes +issues with subdevice drivers that let the V4L2 core manage the active state, +as they expect to receive the appropriate state as a parameter. To help the +conversion of subdevice drivers to a managed active state without having to +convert all callers at the same time, an additional wrapper layer has been +added to v4l2_subdev_call(), which handles the NULL case by getting and locking +the callee's active state with :c:func:`v4l2_subdev_lock_and_get_active_state()`, +and unlocking the state after the call. + +The whole subdev state is in reality split into three parts: the +v4l2_subdev_state, subdev controls and subdev driver's internal state. In the +future these parts should be combined into a single state. For the time being +we need a way to handle the locking for these parts. This can be accomplished +by sharing a lock. The v4l2_ctrl_handler already supports this via its 'lock' +pointer and the same model is used with states. The driver can do the following +before calling v4l2_subdev_init_finalize(): + +.. code-block:: c + + sd->ctrl_handler->lock = &priv->mutex; + sd->state_lock = &priv->mutex; + +This shares the driver's private mutex between the controls and the states. + +Streams, multiplexed media pads and internal routing +---------------------------------------------------- + +A subdevice driver can implement support for multiplexed streams by setting +the V4L2_SUBDEV_FL_STREAMS subdev flag and implementing support for +centrally managed subdev active state, routing and stream based +configuration. + +V4L2 sub-device functions and data structures +--------------------------------------------- + +.. kernel-doc:: include/media/v4l2-subdev.h diff --git a/Documentation/driver-api/media/v4l2-tuner.rst b/Documentation/driver-api/media/v4l2-tuner.rst new file mode 100644 index 000000000..e6caa3321 --- /dev/null +++ b/Documentation/driver-api/media/v4l2-tuner.rst @@ -0,0 +1,8 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Tuner functions and data structures +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +.. kernel-doc:: include/media/tuner.h + +.. kernel-doc:: include/media/tuner-types.h diff --git a/Documentation/driver-api/media/v4l2-tveeprom.rst b/Documentation/driver-api/media/v4l2-tveeprom.rst new file mode 100644 index 000000000..43fb391ed --- /dev/null +++ b/Documentation/driver-api/media/v4l2-tveeprom.rst @@ -0,0 +1,6 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Hauppauge TV EEPROM functions and data structures +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +.. kernel-doc:: include/media/tveeprom.h diff --git a/Documentation/driver-api/media/v4l2-videobuf2.rst b/Documentation/driver-api/media/v4l2-videobuf2.rst new file mode 100644 index 000000000..1044f64ff --- /dev/null +++ b/Documentation/driver-api/media/v4l2-videobuf2.rst @@ -0,0 +1,12 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. _vb2_framework: + +V4L2 videobuf2 functions and data structures +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +.. kernel-doc:: include/media/videobuf2-core.h + +.. kernel-doc:: include/media/videobuf2-v4l2.h + +.. kernel-doc:: include/media/videobuf2-memops.h |