[PATCH 23/26] drm/amd/display: Increase Backlight Gain Step Size

[sunpeng.li at amd.com]

From: Eryk Brol <eryk.brol at amd.com>

[Why]
Some backlight tests fail due to backlight settling
taking too long. This happens because the step
size used to change backlight levels is too small.

[How]
1. Change the size of the backlight gain step size
2. Change how DMCU firmware gets the step size value
   so that it is passed in by driver during DMCU initn

Signed-off-by: Eryk Brol <eryk.brol at amd.com>
Reviewed-by: Jun Lei <Jun.Lei at amd.com>
Acked-by: Leo Li <sunpeng.li at amd.com>
---
 drivers/gpu/drm/amd/display/dc/dce/dce_dmcu.c | 3 +++
 drivers/gpu/drm/amd/display/dc/dce/dce_dmcu.h | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_dmcu.c b/drivers/gpu/drm/amd/display/dc/dce/dce_dmcu.c
index 6504227..c2bc36f 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_dmcu.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_dmcu.c
@@ -388,6 +388,9 @@ static bool dcn10_dmcu_init(struct dmcu *dmcu)
 		/* Set initialized ramping boundary value */
 		REG_WRITE(MASTER_COMM_DATA_REG1, 0xFFFF);
 
+		/* Set backlight ramping stepsize */
+		REG_WRITE(MASTER_COMM_DATA_REG2, abm_gain_stepsize);
+
 		/* Set command to initialize microcontroller */
 		REG_UPDATE(MASTER_COMM_CMD_REG, MASTER_COMM_CMD_REG_BYTE0,
 			MCP_INIT_DMCU);
diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_dmcu.h b/drivers/gpu/drm/amd/display/dc/dce/dce_dmcu.h
index 60ce56f..5bd0df5 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_dmcu.h
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_dmcu.h
@@ -263,4 +263,6 @@ struct dmcu *dcn10_dmcu_create(
 
 void dce_dmcu_destroy(struct dmcu **dmcu);
 
+static const uint32_t abm_gain_stepsize = 0x0060;
+
 #endif /* _DCE_ABM_H_ */
-- 
2.7.4