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| author | Aishwarya Pant <aishpant@gmail.com> | 2018-02-13 19:54:10 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2018-02-21 23:36:39 +0100 |
| commit | 4f1c29d0dc7bde6df1c485f139fd8ee1d10b3485 (patch) | |
| tree | a0a939369a8ce66cac4c488862cab894da5bbddf /Documentation/ABI/testing/sysfs-bus-acpi | |
| parent | Linux 4.16-rc2 (diff) | |
| download | linux-4f1c29d0dc7bde6df1c485f139fd8ee1d10b3485.tar.xz linux-4f1c29d0dc7bde6df1c485f139fd8ee1d10b3485.zip | |
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>
Diffstat (limited to 'Documentation/ABI/testing/sysfs-bus-acpi')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-acpi | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-acpi b/Documentation/ABI/testing/sysfs-bus-acpi index 7fa9cbc75344..e7898cfe5fb1 100644 --- 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. |