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Diffstat (limited to 'Documentation/ABI/testing/sysfs-bus-i3c')
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diff --git a/Documentation/ABI/testing/sysfs-bus-i3c b/Documentation/ABI/testing/sysfs-bus-i3c new file mode 100644 index 000000000..19f5cf8b1 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-i3c @@ -0,0 +1,194 @@ +What: /sys/bus/i3c/devices/i3c-<bus-id> +KernelVersion: 5.0 +Contact: linux-i3c@vger.kernel.org +Description: + An I3C bus. This directory will contain one sub-directory per + I3C device present on the bus. + +What: /sys/bus/i3c/devices/i3c-<bus-id>/current_master +KernelVersion: 5.0 +Contact: linux-i3c@vger.kernel.org +Description: + Expose the master that owns the bus (<bus-id>-<master-pid>) at + the time this file is read. Note that bus ownership can change + overtime, so there's no guarantee that when the read() call + returns, the value returned is still valid. + +What: /sys/bus/i3c/devices/i3c-<bus-id>/mode +KernelVersion: 5.0 +Contact: linux-i3c@vger.kernel.org +Description: + I3C bus mode. Can be "pure", "mixed-fast" or "mixed-slow". See + the I3C specification for a detailed description of what each + of these modes implies. + +What: /sys/bus/i3c/devices/i3c-<bus-id>/i3c_scl_frequency +KernelVersion: 5.0 +Contact: linux-i3c@vger.kernel.org +Description: + The frequency (expressed in Hz) of the SCL signal when + operating in I3C SDR mode. + +What: /sys/bus/i3c/devices/i3c-<bus-id>/i2c_scl_frequency +KernelVersion: 5.0 +Contact: linux-i3c@vger.kernel.org +Description: + The frequency (expressed in Hz) of the SCL signal when + operating in I2C mode. + +What: /sys/bus/i3c/devices/i3c-<bus-id>/dynamic_address +KernelVersion: 5.0 +Contact: linux-i3c@vger.kernel.org +Description: + Dynamic address assigned to the master controller. This + address may change if the bus is re-initialized. + +What: /sys/bus/i3c/devices/i3c-<bus-id>/bcr +KernelVersion: 5.0 +Contact: linux-i3c@vger.kernel.org +Description: + BCR stands for Bus Characteristics Register and express the + device capabilities in term of speed, maximum read/write + length, etc. See the I3C specification for more details. + This entry describes the BCR of the master controller driving + the bus. + +What: /sys/bus/i3c/devices/i3c-<bus-id>/dcr +KernelVersion: 5.0 +Contact: linux-i3c@vger.kernel.org +Description: + DCR stands for Device Characteristics Register and express the + device capabilities in term of exposed features. See the I3C + specification for more details. + This entry describes the DCR of the master controller driving + the bus. + +What: /sys/bus/i3c/devices/i3c-<bus-id>/pid +KernelVersion: 5.0 +Contact: linux-i3c@vger.kernel.org +Description: + PID stands for Provisioned ID and is used to uniquely identify + a device on a bus. This PID contains information about the + vendor, the part and an instance ID so that several devices of + the same type can be connected on the same bus. + See the I3C specification for more details. + This entry describes the PID of the master controller driving + the bus. + +What: /sys/bus/i3c/devices/i3c-<bus-id>/hdrcap +KernelVersion: 5.0 +Contact: linux-i3c@vger.kernel.org +Description: + Expose the HDR (High Data Rate) capabilities of a device. + Returns a list of supported HDR mode, each element is separated + by space. Modes can be "hdr-ddr", "hdr-tsp" and "hdr-tsl". + See the I3C specification for more details about these HDR + modes. + + This entry describes the HDRCAP of the master controller + driving the bus. + +What: /sys/bus/i3c/devices/i3c-<bus-id>/hotjoin +KernelVersion: 6.8 +Contact: linux-i3c@vger.kernel.org +Description: + I3C’s Hot-Join mechanism allows an I3C Device to inform the + Active Controller that a newly-joined Target is present on the + I3C Bus and is ready to receive a Dynamic Address, in order to + become fully functional on the Bus. Hot-Join is used when the + Target is mounted on the same I3C bus and remains depowered + until needed or until the Target is physically inserted into the + I3C bus + + This entry allows to enable or disable Hot-join of the Current + Controller driving the bus. + +What: /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid> +KernelVersion: 5.0 +Contact: linux-i3c@vger.kernel.org +Description: + An I3C device present on I3C bus identified by <bus-id>. Note + that all devices are represented including the master driving + the bus. + +What: /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>/dynamic_address +KernelVersion: 5.0 +Contact: linux-i3c@vger.kernel.org +Description: + Dynamic address assigned to device <bus-id>-<device-pid>. This + address may change if the bus is re-initialized. + +What: /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>/bcr +KernelVersion: 5.0 +Contact: linux-i3c@vger.kernel.org +Description: + BCR stands for Bus Characteristics Register and express the + device capabilities in term of speed, maximum read/write + length, etc. See the I3C specification for more details. + +What: /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>/dcr +KernelVersion: 5.0 +Contact: linux-i3c@vger.kernel.org +Description: + DCR stands for Device Characteristics Register and express the + device capabilities in term of exposed features. See the I3C + specification for more details. + +What: /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>/pid +KernelVersion: 5.0 +Contact: linux-i3c@vger.kernel.org +Description: + PID stands for Provisioned ID and is used to uniquely identify + a device on a bus. This PID contains information about the + vendor, the part and an instance ID so that several devices of + the same type can be connected on the same bus. + See the I3C specification for more details. + +What: /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>/hdrcap +KernelVersion: 5.0 +Contact: linux-i3c@vger.kernel.org +Description: + Expose the HDR (High Data Rate) capabilities of a device. + Returns a list of supported HDR mode, each element is separated + by space. Modes can be "hdr-ddr", "hdr-tsp" and "hdr-tsl". + + See the I3C specification for more details about these HDR + modes. + +What: /sys/bus/i3c/devices/<bus-id>-<device-pid> +KernelVersion: 5.0 +Contact: linux-i3c@vger.kernel.org +Description: + These directories are just symbolic links to + /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>. + +What: /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>/dev_nack_retry_count +KernelVersion: 6.18 +Contact: linux-i3c@vger.kernel.org +Description: + Expose the dev_nak_retry_count which controls the number of + automatic retries that will be performed by the controller when + the target device returns a NACK response. A value of 0 disables + the automatic retries. Exist only when I3C constroller supports + this retry on nack feature. + +What: /sys/bus/i3c/devices/i3c-<bus-id>/do_daa +KernelVersion: 7.0 +Contact: linux-i3c@vger.kernel.org +Description: + Write-only attribute that triggers a Dynamic Address Assignment + (DAA) procedure which discovers new I3C devices on the bus. + Writing a boolean true value (1, y, yes, true, on) to this + attribute causes the master controller to perform DAA, which + includes broadcasting an ENTDAA (Enter Dynamic Address Assignment) + Common Command Code (CCC) on the bus. Writing a false value + returns -EINVAL. + + This is useful for discovering I3C devices that were not present + during initial bus initialization and are unable to issue + Hot-Join. Only devices without a currently assigned dynamic address + will respond to the ENTDAA broadcast and be assigned addresses. + + Note that this mechanism is distinct from Hot-Join, since this is + controller-initiated discovery, while Hot-Join is device-initiated + method to provoke controller discovery procedure. |