radeon: expose backlight class device for legacy LVDS encoder

Allows e.g. power management daemons to control the backlight level. Inspired
by the corresponding code in radeonfb.

[mjg@redhat.com: updated to add backlight type and make the connector the parent device]
Signed-off-by: Michel Dänzer <michel@daenzer.net>
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>
Acked-by: 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>
Tested-by: Sedat Dilek <sedat.dilek@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/Kconfig b/drivers/gpu/drm/radeon/Kconfig
index 1c02d23f6fcc..9746fee59f56 100644
--- a/drivers/gpu/drm/radeon/Kconfig
+++ b/drivers/gpu/drm/radeon/Kconfig
@@ -1,6 +1,7 @@
 config DRM_RADEON_KMS
         bool "Enable modesetting on radeon by default - NEW DRIVER"
         depends on DRM_RADEON
+        select BACKLIGHT_CLASS_DEVICE
         help
           Choose this option if you want kernel modesetting enabled by default.