drm/radeon: add get_backlight_level callback
Read back the backlight level from the hw.
Needed for proper backlight restoration on resume.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/radeon_legacy_encoders.c b/drivers/gpu/drm/radeon/radeon_legacy_encoders.c
index ec00dea..8ad9c5f 100644
--- a/drivers/gpu/drm/radeon/radeon_legacy_encoders.c
+++ b/drivers/gpu/drm/radeon/radeon_legacy_encoders.c
@@ -290,6 +290,19 @@
return level;
}
+u8
+radeon_legacy_get_backlight_level(struct radeon_encoder *radeon_encoder)
+{
+ struct drm_device *dev = radeon_encoder->base.dev;
+ struct radeon_device *rdev = dev->dev_private;
+ u8 backlight_level;
+
+ backlight_level = (RREG32(RADEON_LVDS_GEN_CNTL) >>
+ RADEON_LVDS_BL_MOD_LEVEL_SHIFT) & 0xff;
+
+ return backlight_level;
+}
+
void
radeon_legacy_set_backlight_level(struct radeon_encoder *radeon_encoder, u8 level)
{