Unverified Commit 618ba6ab authored by Armin Wolf's avatar Armin Wolf Committed by Ilpo Järvinen
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platform/x86: wmi: Add bus ABI documentation 



Add documentation for the WMI bus sysfs interface so userspace
applications can use it to access additional data about WMI devices.

Reviewed-by: default avatarHans de Goede <hdegoede@redhat.com>
Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: default avatarArmin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20240624173116.31314-3-W_Armin@gmx.de


Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
parent 12046f8c

Documentation/ABI/testing/sysfs-bus-wmi

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What:		/sys/bus/wmi/devices/.../driver_override

Date:		February 2024

Contact:	Armin Wolf <W_Armin@gmx.de>

Description:

		This file allows the driver for a device to be specified which

		will override standard ID table matching.

		When specified, only a driver with a name matching the value

		written to driver_override will have an opportunity to bind

		to the device.

		The override is specified by writing a string to the

		driver_override file (echo wmi-event-dummy > driver_override).

		The override may be cleared with an empty string (echo > \

		driver_override) which returns the device to standard matching

		rules binding.

		Writing to driver_override does not automatically unbind the

		device from its current driver or make any attempt to automatically

		load the specified driver. If no driver with a matching name is

		currently loaded in the kernel, the device will not bind to any

		driver.

		This also allows devices to opt-out of driver binding using a

		driver_override name such as "none". Only a single driver may be

		specified in the override, there is no support for parsing delimiters.



What:		/sys/bus/wmi/devices/.../modalias

Date:		November 20:15

Contact:	Andy Lutomirski <luto@kernel.org>

Description:

		This file contains the MODALIAS value emitted by uevent for a

		given WMI device.



		Format: wmi:XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX.



What:		/sys/bus/wmi/devices/.../guid

Date:		November 2015

Contact:	Andy Lutomirski <luto@kernel.org>

Description:

		This file contains the GUID used to match WMI devices to

		compatible WMI drivers. This GUID is not necessarily unique

		inside a given machine, it is solely used to identify the

		interface exposed by a given WMI device.



What:		/sys/bus/wmi/devices/.../object_id

Date:		November 2015

Contact:	Andy Lutomirski <luto@kernel.org>

Description:

		This file contains the WMI object ID used internally to construct

		the ACPI method names used by non-event WMI devices. It contains

		two ASCII letters.



What:		/sys/bus/wmi/devices/.../notify_id

Date:		November 2015

Contact:	Andy Lutomirski <luto@kernel.org>

Description:

		This file contains the WMI notify ID used internally to map ACPI

		events to WMI event devices. It contains two ASCII letters.



What:		/sys/bus/wmi/devices/.../instance_count

Date:		November 2015

Contact:	Andy Lutomirski <luto@kernel.org>

Description:

		This file contains the number of WMI object instances being

		present on a given WMI device. It contains a non-negative

		number.



What:		/sys/bus/wmi/devices/.../expensive

Date:		November 2015

Contact:	Andy Lutomirski <luto@kernel.org>

Description:

		This file contains a boolean flag signaling if interacting with

		the given WMI device will consume significant CPU resources.

		The WMI driver core will take care of enabling/disabling such

		WMI devices.



What:		/sys/bus/wmi/devices/.../setable

Date:		May 2017

Contact:	Darren Hart (VMware) <dvhart@infradead.org>

Description:

		This file contains a boolean flags signaling the data block

		aassociated with the given WMI device is writable. If the

		given WMI device is not associated with a data block, then

		this file will not exist.

MAINTAINERS

+1 −0
Original line number Diff line number Diff line
@@ -392,6 +392,7 @@ ACPI WMI DRIVER 
M:	Armin Wolf <W_Armin@gmx.de>

L:	platform-driver-x86@vger.kernel.org

S:	Maintained

F:	Documentation/ABI/testing/sysfs-bus-wmi

F:	Documentation/driver-api/wmi.rst

F:	Documentation/wmi/

F:	drivers/platform/x86/wmi.c