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 <aishp...@gmail.com>
---
Documentation/ABI/testing/sysfs-bus-acpi | 36 ++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-acpi
b/Documentation/ABI/testing/sysfs-bus-acpi
index 7fa9cbc75344..89feb01d1d0d 100644
--- a/Documentation/ABI/testing/sysfs-bus-acpi
+++ b/Documentation/ABI/testing/sysfs-bus-acpi
@@ -56,3 +56,39 @@ 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 <r...@rjwysocki.net>
+Description:
+ (RO) Displays the ACPI device status - enabled, disabled or
+ functioning or present, if the method _STA is present.
+
+ Return value is an integer containing a device 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 cleared, then bit 1 must also be cleared (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 <r...@rjwysocki.net>
+Description:
+ (RO) Allows users to read the hardware version of non-PCI
+ hardware, if the _HRV control method is present. It is most
+ useful for non-PCI devices because lspci can list the hardware
+ version for PCI devices.
--
2.16.1
