xref: /linux/Documentation/ABI/testing/sysfs-bus-wmi (revision a1ff5a7d78a036d6c2178ee5acd6ba4946243800)
1What:		/sys/bus/wmi/devices/.../driver_override
2Date:		February 2024
3Contact:	Armin Wolf <W_Armin@gmx.de>
4Description:
5		This file allows the driver for a device to be specified which
6		will override standard ID table matching.
7		When specified, only a driver with a name matching the value
8		written to driver_override will have an opportunity to bind
9		to the device.
10		The override is specified by writing a string to the
11		driver_override file (echo wmi-event-dummy > driver_override).
12		The override may be cleared with an empty string (echo > \
13		driver_override) which returns the device to standard matching
14		rules binding.
15		Writing to driver_override does not automatically unbind the
16		device from its current driver or make any attempt to automatically
17		load the specified driver. If no driver with a matching name is
18		currently loaded in the kernel, the device will not bind to any
19		driver.
20		This also allows devices to opt-out of driver binding using a
21		driver_override name such as "none". Only a single driver may be
22		specified in the override, there is no support for parsing delimiters.
23
24What:		/sys/bus/wmi/devices/.../modalias
25Date:		November 20:15
26Contact:	Andy Lutomirski <luto@kernel.org>
27Description:
28		This file contains the MODALIAS value emitted by uevent for a
29		given WMI device.
30
31		Format: wmi:XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX.
32
33What:		/sys/bus/wmi/devices/.../guid
34Date:		November 2015
35Contact:	Andy Lutomirski <luto@kernel.org>
36Description:
37		This file contains the GUID used to match WMI devices to
38		compatible WMI drivers. This GUID is not necessarily unique
39		inside a given machine, it is solely used to identify the
40		interface exposed by a given WMI device.
41
42What:		/sys/bus/wmi/devices/.../object_id
43Date:		November 2015
44Contact:	Andy Lutomirski <luto@kernel.org>
45Description:
46		This file contains the WMI object ID used internally to construct
47		the ACPI method names used by non-event WMI devices. It contains
48		two ASCII letters.
49
50What:		/sys/bus/wmi/devices/.../notify_id
51Date:		November 2015
52Contact:	Andy Lutomirski <luto@kernel.org>
53Description:
54		This file contains the WMI notify ID used internally to map ACPI
55		events to WMI event devices. It contains two ASCII letters.
56
57What:		/sys/bus/wmi/devices/.../instance_count
58Date:		November 2015
59Contact:	Andy Lutomirski <luto@kernel.org>
60Description:
61		This file contains the number of WMI object instances being
62		present on a given WMI device. It contains a non-negative
63		number.
64
65What:		/sys/bus/wmi/devices/.../expensive
66Date:		November 2015
67Contact:	Andy Lutomirski <luto@kernel.org>
68Description:
69		This file contains a boolean flag signaling if interacting with
70		the given WMI device will consume significant CPU resources.
71		The WMI driver core will take care of enabling/disabling such
72		WMI devices.
73
74What:		/sys/bus/wmi/devices/.../setable
75Date:		May 2017
76Contact:	Darren Hart (VMware) <dvhart@infradead.org>
77Description:
78		This file contains a boolean flags signaling the data block
79		aassociated with the given WMI device is writable. If the
80		given WMI device is not associated with a data block, then
81		this file will not exist.
82