xref: /linux/Documentation/ABI/testing/sysfs-bus-platform (revision 03ab8e6297acd1bc0eedaa050e2a1635c576fd11)
1What:		/sys/bus/platform/devices/.../driver_override
2Date:		April 2014
3Contact:	Kim Phillips <kim.phillips@freescale.com>
4Description:
5		This file allows the driver for a device to be specified which
6		will override standard OF, ACPI, ID table, and name 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.  The override is specified by writing a string
10		to the driver_override file (echo vfio-platform > \
11		driver_override) and may be cleared with an empty string
12		(echo > driver_override).  This returns the device to standard
13		matching rules binding.  Writing to driver_override does not
14		automatically unbind the device from its current driver or make
15		any attempt to automatically load the specified driver.  If no
16		driver with a matching name is currently loaded in the kernel,
17		the device will not bind to any driver.  This also allows
18		devices to opt-out of driver binding using a driver_override
19		name such as "none".  Only a single driver may be specified in
20		the override, there is no support for parsing delimiters.
21
22What:		/sys/bus/platform/devices/.../numa_node
23Date:		June 2020
24Contact:	Barry Song <song.bao.hua@hisilicon.com>
25Description:
26		This file contains the NUMA node to which the platform device
27		is attached. It won't be visible if the node is unknown. The
28		value comes from an ACPI _PXM method or a similar firmware
29		source. Initial users for this file would be devices like
30		arm smmu which are populated by arm64 acpi_iort.
31
32What:		/sys/bus/platform/devices/.../msi_irqs/
33Date:		August 2021
34Contact:	Barry Song <song.bao.hua@hisilicon.com>
35Description:
36		The /sys/devices/.../msi_irqs directory contains a variable set
37		of files, with each file being named after a corresponding msi
38		irq vector allocated to that device.
39
40What:		/sys/bus/platform/devices/.../msi_irqs/<N>
41Date:		August 2021
42Contact:	Barry Song <song.bao.hua@hisilicon.com>
43Description:
44		This attribute will show "msi" if <N> is a valid msi irq
45
46What:		/sys/bus/platform/devices/.../modalias
47Description:
48		Same as MODALIAS in the uevent at device creation.
49
50		A platform device that it is exposed via devicetree uses:
51
52			- of:N`of node name`T`type`
53
54		Other platform devices use, instead:
55
56			- platform:`driver name`
57