linux/Documentation/ABI/testing/sysfs-bus-acpi
Aishwarya Pant 4f1c29d0dc ACPI: sysfs: Update device object sysfs documentation
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>
2018-02-21 23:36:39 +01:00

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What: /sys/bus/acpi/devices/.../path
Date: December 2006
Contact: Rafael J. Wysocki <rjw@rjwysocki.net>
Description:
This attribute indicates the full path of ACPI namespace
object associated with the device object. For example,
\_SB_.PCI0.
This file is not present for device objects representing
fixed ACPI hardware features (like power and sleep
buttons).
What: /sys/bus/acpi/devices/.../modalias
Date: July 2007
Contact: Rafael J. Wysocki <rjw@rjwysocki.net>
Description:
This attribute indicates the PNP IDs of the device object.
That is acpi:HHHHHHHH:[CCCCCCC:]. Where each HHHHHHHH or
CCCCCCCC contains device object's PNPID (_HID or _CID).
What: /sys/bus/acpi/devices/.../hid
Date: April 2005
Contact: Rafael J. Wysocki <rjw@rjwysocki.net>
Description:
This attribute indicates the hardware ID (_HID) of the
device object. For example, PNP0103.
This file is present for device objects having the _HID
control method.
What: /sys/bus/acpi/devices/.../description
Date: October 2012
Contact: Rafael J. Wysocki <rjw@rjwysocki.net>
Description:
This attribute contains the output of the device object's
_STR control method, if present.
What: /sys/bus/acpi/devices/.../adr
Date: October 2012
Contact: Rafael J. Wysocki <rjw@rjwysocki.net>
Description:
This attribute contains the output of the device object's
_ADR control method, which is present for ACPI device
objects representing devices having standard enumeration
algorithms, such as PCI.
What: /sys/bus/acpi/devices/.../uid
Date: October 2012
Contact: Rafael J. Wysocki <rjw@rjwysocki.net>
Description:
This attribute contains the output of the device object's
_UID control method, if present.
What: /sys/bus/acpi/devices/.../eject
Date: December 2006
Contact: Rafael J. Wysocki <rjw@rjwysocki.net>
Description:
Writing 1 to this attribute will trigger hot removal of
this device object. This file exists for every device
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.