xref: /OK3568_Linux_fs/kernel/Documentation/ABI/testing/sysfs-bus-platform (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunWhat:		/sys/bus/platform/devices/.../driver_override
2*4882a593SmuzhiyunDate:		April 2014
3*4882a593SmuzhiyunContact:	Kim Phillips <kim.phillips@freescale.com>
4*4882a593SmuzhiyunDescription:
5*4882a593Smuzhiyun		This file allows the driver for a device to be specified which
6*4882a593Smuzhiyun		will override standard OF, ACPI, ID table, and name matching.
7*4882a593Smuzhiyun		When specified, only a driver with a name matching the value
8*4882a593Smuzhiyun		written to driver_override will have an opportunity to bind
9*4882a593Smuzhiyun		to the device.  The override is specified by writing a string
10*4882a593Smuzhiyun		to the driver_override file (echo vfio-platform > \
11*4882a593Smuzhiyun		driver_override) and may be cleared with an empty string
12*4882a593Smuzhiyun		(echo > driver_override).  This returns the device to standard
13*4882a593Smuzhiyun		matching rules binding.  Writing to driver_override does not
14*4882a593Smuzhiyun		automatically unbind the device from its current driver or make
15*4882a593Smuzhiyun		any attempt to automatically load the specified driver.  If no
16*4882a593Smuzhiyun		driver with a matching name is currently loaded in the kernel,
17*4882a593Smuzhiyun		the device will not bind to any driver.  This also allows
18*4882a593Smuzhiyun		devices to opt-out of driver binding using a driver_override
19*4882a593Smuzhiyun		name such as "none".  Only a single driver may be specified in
20*4882a593Smuzhiyun		the override, there is no support for parsing delimiters.
21*4882a593Smuzhiyun
22*4882a593SmuzhiyunWhat:		/sys/bus/platform/devices/.../numa_node
23*4882a593SmuzhiyunDate:		June 2020
24*4882a593SmuzhiyunContact:	Barry Song <song.bao.hua@hisilicon.com>
25*4882a593SmuzhiyunDescription:
26*4882a593Smuzhiyun		This file contains the NUMA node to which the platform device
27*4882a593Smuzhiyun		is attached. It won't be visible if the node is unknown. The
28*4882a593Smuzhiyun		value comes from an ACPI _PXM method or a similar firmware
29*4882a593Smuzhiyun		source. Initial users for this file would be devices like
30*4882a593Smuzhiyun		arm smmu which are populated by arm64 acpi_iort.
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