backlight: add backlight type

There may be multiple ways of controlling the backlight on a given
machine.  Allow drivers to expose the type of interface they are
providing, making it possible for userspace to make appropriate policy
decisions.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: David Airlie <airlied@linux.ie>
Cc: Alex Deucher <alexdeucher@gmail.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/backlight.h b/include/linux/backlight.h
index 4a3d52e545e1..5ffc6dda4675 100644
--- a/include/linux/backlight.h
+++ b/include/linux/backlight.h
@@ -32,6 +32,13 @@ enum backlight_update_reason {
         BACKLIGHT_UPDATE_SYSFS,
 };
 
+enum backlight_type {
+        BACKLIGHT_RAW = 1,
+        BACKLIGHT_PLATFORM,
+        BACKLIGHT_FIRMWARE,
+        BACKLIGHT_TYPE_MAX,
+};
+
 struct backlight_device;
 struct fb_info;
 
@@ -62,6 +69,8 @@ struct backlight_properties {
         /* FB Blanking active? (values as for power) */
         /* Due to be removed, please use (state & BL_CORE_FBBLANK) */
         int fb_blank;
+        /* Backlight type */
+        enum backlight_type type;
         /* Flags used to signal drivers of state changes */
         /* Upper 4 bits are reserved for driver internal use */
         unsigned int state;