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/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
index 266036b..5ce13b8fb 100644
--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@@ -72,6 +72,18 @@
WREG32(RADEON_BIOS_2_SCRATCH, bios_2_scratch);
}
+u8
+atombios_get_backlight_level(struct radeon_encoder *radeon_encoder)
+{
+ struct drm_device *dev = radeon_encoder->base.dev;
+ struct radeon_device *rdev = dev->dev_private;
+
+ if (!(rdev->mode_info.firmware_flags & ATOM_BIOS_INFO_BL_CONTROLLED_BY_GPU))
+ return 0;
+
+ return radeon_atom_get_backlight_level_from_reg(rdev);
+}
+
void
atombios_set_backlight_level(struct radeon_encoder *radeon_encoder, u8 level)
{