drm/amd: Add abm level drm property

Adaptive Backlight Management (ABM) is a feature
that reduces backlight level to save power, while
increasing pixel contrast and pixel luminance
to maintain readability and image quality.

ABM will adjust in response to the
pixel luminance of the displayed content.

ABM is made available as a drm property on eDP
monitors called "abm level", which ranges from 0 to 4.
When this property is set to 0, ABM is off.  Levels 1
to 4 represent different ranges of backlight reduction.
At higher levels both the backlight reduction and pixel
adjustment will be greater.

ABM requires DMCU firmware, which is currently available for
Raven ASICs only.  If the feature does not work, please
ensure your firmware is up to date.

v2:
Fix commit message, only attach property if DMCU loaded
v3:
Store ABM level in crtc state to accommodate dc
v4:
Fix ABM saving on dpms cycle

Signed-off-by: David Francis <David.Francis@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 10 insertions, 1 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
index 1d8bd554869b..dba6b57830c7 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -1686,6 +1686,15 @@ void dc_resume(struct dc *dc)
 		core_link_resume(dc->links[i]);
 }
 
+bool dc_is_dmcu_initialized(struct dc *dc)
+{
+	struct dmcu *dmcu = dc->res_pool->dmcu;
+
+	if (dmcu)
+		return dmcu->funcs->is_dmcu_initialized(dmcu);
+	return false;
+}
+
 bool dc_submit_i2c(
 		struct dc *dc,
 		uint32_t link_index,
@@ -1810,4 +1819,4 @@ void get_clock_requirements_for_state(struct dc_state *state, struct AsicStateEx
 	info->dcfClockDeepSleep			= (unsigned int)state->bw.dcn.clk.dcfclk_deep_sleep_khz;
 	info->fClock					= (unsigned int)state->bw.dcn.clk.fclk_khz;
 	info->phyClock					= (unsigned int)state->bw.dcn.clk.phyclk_khz;
-}
\ No newline at end of file
+}