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>

diff --git a/Documentation/ABI/testing/sysfs-bus-acpi b/Documentation/ABI/testing/sysfs-bus-acpi
index 7fa9cbc75344dd7567a4bdaba659a70e86eb02fd..e7898cfe5fb12e8d5e4a6d52bd48dafa2c10bb22 100644 (file)
--- a/Documentation/ABI/testing/sysfs-bus-acpi
+++ b/Documentation/ABI/testing/sysfs-bus-acpi
@@ -56,3 +56,40 @@ 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.