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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-24 08:46:03 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-24 08:46:03 -0700 |
| commit | cf9610f9116d55c5a66ef9f1faecacabd93a9322 (patch) | |
| tree | 757a3d280760c654767631cab5ad8af2d86d1848 /Documentation/input/userio.rst | |
| download | linux-stable-cf9610f9116d55c5a66ef9f1faecacabd93a9322.tar.gz linux-stable-cf9610f9116d55c5a66ef9f1faecacabd93a9322.zip | |
Merge tag 'pinctrl-v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrlgrafted
Pull pin control updates from Linus Walleij:
"Core changes:
- Use the non-blocking mux_state_try_select() in the generic MUX pin
control back-end
- Free pin maps on pinctrl_generic_to_map() failure in the core
helpers
New hardware pin control:
- Qualcomm Maili TLMM SoC, PMG1110 PMIC, and Eliza LPASS LPI TLMM SoC
(this is for the low power audio, LPASS = Low Power Audio SubSystem
portions)
- Upboard support on top of the Intel pin controller
- Apple T6030 and T6031 support (just compatible strings)
- Samsung Exynos 8855 SoC
- Mediatek MT6858 SoC
- Rockchip RK3308B and RV1106 SoCs
- Airoha EN7523 and AN7563 SoCs
Improvements:
- Qualcomm TLMM GPIOs are unconditionally marked as wakeup capable
- Qualcomm improvements on top of the Qualcomm PDC (power domain
controller) irqchip improvements from tglx:s tree
- Qualcomm IPQ806x and IPQ9650 non-urgent pin grop fixups
- The NPCM8xx driver has been put into shape fixing many pin and
group definitions
- Some non-urgent Tegra 264 pin assignments are fixed up
- Some non-urgent fixups to Airoha AN7581 and AN7583 registers and
pin assignments, missing features etc"
* tag 'pinctrl-v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (130 commits)
dt-bindings: pinctrl: Convert TI DA850 pupd to DT schema
pinctrl: meson: sync some modify from A4
pinctrl: meson: a4: Add input enable pin configuration
pinctrl: realtek: rtd1625: remove unused group name spdif_sel
pinctrl: realtek: rtd1625: fix base_bit for VE4 GPIO 13
dt-bindings: pinctrl: microchip,pic32mzda-pinctrl: Convert to DT schema
Revert "Merge branch 'ib-rsk7204' into devel"
pinctrl: rockchip: Add RV1106 pinctrl support
dt-bindings: pinctrl: rockchip: Add RV1106 compatible
pinctrl: rockchip: Decode drive strength in the get function
pinctrl: fix PINCTRL_GENERIC_MUX not always being selectable
pinctrl: airoha: add support of an7563 SoC
dt-bindings: pinctrl: airoha: add support of an7563 pin controller
pinctrl: airoha: try to find chip scu node by phandle first
pinctrl: airoha: add support of en7523 SoC
dt-bindings: pinctrl: airoha: add support of en7523 pin controller
pinctrl: airoha: an7583: add support for olt pinmux
pinctrl: airoha: an7583: add support for pon_alt pinmux
pinctrl: airoha: an7583: add support for npu_uart pinmux
dt-bindings: pinctrl: airoha: an7583: add missed features
...
Diffstat (limited to 'Documentation/input/userio.rst')
| -rw-r--r-- | Documentation/input/userio.rst | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/Documentation/input/userio.rst b/Documentation/input/userio.rst new file mode 100644 index 000000000..7aaaa629b --- /dev/null +++ b/Documentation/input/userio.rst @@ -0,0 +1,104 @@ +.. include:: <isonum.txt> + +=================== +The userio Protocol +=================== + + +:Copyright: |copy| 2015 Lyude Paul <thatslyude@gmail.com> + +Sponsored by Red Hat + + +Introduction +============= + +This module is intended to try to make the lives of input driver developers +easier by allowing them to test various serio devices (mainly the various +touchpads found on laptops) without having to have the physical device in front +of them. userio accomplishes this by allowing any privileged userspace program +to directly interact with the kernel's serio driver and control a virtual serio +port from there. + +Usage overview +============== + +In order to interact with the userio kernel module, one simply opens the +/dev/userio character device in their applications. Commands are sent to the +kernel module by writing to the device, and any data received from the serio +driver is read as-is from the /dev/userio device. All of the structures and +macros you need to interact with the device are defined in <linux/userio.h> and +<linux/serio.h>. + +Command Structure +================= + +The struct used for sending commands to /dev/userio is as follows:: + + struct userio_cmd { + __u8 type; + __u8 data; + }; + +``type`` describes the type of command that is being sent. This can be any one +of the USERIO_CMD macros defined in <linux/userio.h>. ``data`` is the argument +that goes along with the command. In the event that the command doesn't have an +argument, this field can be left untouched and will be ignored by the kernel. +Each command should be sent by writing the struct directly to the character +device. In the event that the command you send is invalid, an error will be +returned by the character device and a more descriptive error will be printed +to the kernel log. Only one command can be sent at a time, any additional data +written to the character device after the initial command will be ignored. + +To close the virtual serio port, just close /dev/userio. + +Commands +======== + +USERIO_CMD_REGISTER +~~~~~~~~~~~~~~~~~~~ + +Registers the port with the serio driver and begins transmitting data back and +forth. Registration can only be performed once a port type is set with +USERIO_CMD_SET_PORT_TYPE. Has no argument. + +USERIO_CMD_SET_PORT_TYPE +~~~~~~~~~~~~~~~~~~~~~~~~ + +Sets the type of port we're emulating, where ``data`` is the port type being +set. Can be any of the serio type macros from <linux/serio.h>. For example: +SERIO_8042 would set the port type to be a normal PS/2 port. + +USERIO_CMD_SET_PORT_PROTO +~~~~~~~~~~~~~~~~~~~~~~~~~ + +Sets the protocol of port we're emulating, where ``data`` is the protocol being +set. Can be any of the serio proto macros from <linux/serio.h>. For example: +SERIO_IFORCE would set the port type to be an I-Force serial joystick. + +USERIO_CMD_SET_PORT_ID +~~~~~~~~~~~~~~~~~~~~~~ + +Sets the ``id`` value on the identification of port we're emulating, where +``data`` is the value being set. + +USERIO_CMD_SET_PORT_EXTRA +~~~~~~~~~~~~~~~~~~~~~~~~~ + +Sets the ``extra`` value on the identification of port we're emulating, where +``data`` is the value being set. + +USERIO_CMD_SEND_INTERRUPT +~~~~~~~~~~~~~~~~~~~~~~~~~ + +Sends an interrupt through the virtual serio port to the serio driver, where +``data`` is the interrupt data being sent. + +Userspace tools +=============== + +The userio userspace tools are able to record PS/2 devices using some of the +debugging information from i8042, and play back the devices on /dev/userio. The +latest version of these tools can be found at: + + https://github.com/Lyude/ps2emu |
