Merge git://git.kernel.org/pub/scm/linux/kernel/git/nico/orion into fixes

[pandora-kernel.git] / Documentation / ABI / stable / sysfs-class-backlight

diff --git a/Documentation/ABI/stable/sysfs-class-backlight b/Documentation/ABI/stable/sysfs-class-backlight
index 4d637e1..70302f3 100644 (file)
--- a/Documentation/ABI/stable/sysfs-class-backlight
+++ b/Documentation/ABI/stable/sysfs-class-backlight
@@ -34,3 +34,23 @@ Contact:     Richard Purdie <rpurdie@rpsys.net>
 Description:
                Maximum brightness for <backlight>.
 Users:         HAL
+
+What:          /sys/class/backlight/<backlight>/type
+Date:          September 2010
+KernelVersion: 2.6.37
+Contact:       Matthew Garrett <mjg@redhat.com>
+Description:
+               The type of interface controlled by <backlight>.
+               "firmware": The driver uses a standard firmware interface
+               "platform": The driver uses a platform-specific interface
+               "raw": The driver controls hardware registers directly
+
+               In the general case, when multiple backlight
+               interfaces are available for a single device, firmware
+               control should be preferred to platform control should
+               be preferred to raw control. Using a firmware
+               interface reduces the probability of confusion with
+               the hardware and the OS independently updating the
+               backlight state. Platform interfaces are mostly a
+               holdover from pre-standardisation of firmware
+               interfaces.