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ACPI: sysfs: Update device object sysfs documentation

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Add documentation for two attributes, status and hrv, in
Documentation/ABI/testing/sysfs-bus-acpi.

Compiled from git logs and the ACPI specification.

Signed-off-by: Aishwarya Pant <aishpant@gmail.com>
[ rjw: Minor changes ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Aishwarya Pant 2018-02-14 00:24:10 +05:30 committed by Rafael J. Wysocki
parent 91ab883eb2
commit 4f1c29d0dc
1 changed files with 37 additions and 0 deletions
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Documentation/ABI/testing/sysfs-bus-acpi
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@ -56,3 +56,40 @@ Description:
Writing 1 to this attribute will trigger hot removal of Writing 1 to this attribute will trigger hot removal of
this device object. This file exists for every device this device object. This file exists for every device
object that has _EJ0 method. object that has _EJ0 method.
What: /sys/bus/acpi/devices/.../status
Date: Jan, 2014
Contact: Rafael J. Wysocki <rjw@rjwysocki.net>
Description:
(RO) Returns the ACPI device status: enabled, disabled or
functioning or present, if the method _STA is present.
The return value is a decimal integer representing the device's
status bitmap:
Bit [0] – Set if the device is present.
Bit [1] – Set if the device is enabled and decoding its
resources.
Bit [2] – Set if the device should be shown in the UI.
Bit [3] – Set if the device is functioning properly (cleared if
device failed its diagnostics).
Bit [4] – Set if the battery is present.
Bits [31:5] – Reserved (must be cleared)
If bit [0] is clear, then bit 1 must also be clear (a device
that is not present cannot be enabled).
Bit 0 can be clear (not present) with bit [3] set (device is
functional). This case is used to indicate a valid device for
which no device driver should be loaded.
More special cases are covered in the ACPI specification.
What: /sys/bus/acpi/devices/.../hrv
Date: Apr, 2016
Contact: Rafael J. Wysocki <rjw@rjwysocki.net>
Description:
(RO) Allows users to read the hardware version of non-PCI
hardware, if the _HRV control method is present. It is mostly
useful for non-PCI devices because lspci can list the hardware
version for PCI devices.