diff options
| author | Anthony Koo <Anthony.Koo@amd.com> | 2019-03-28 12:39:48 -0400 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2019-04-15 00:19:16 -0500 |
| commit | 3be0a0b8501585120f8de68e9077ca143024139b (patch) | |
| tree | a6ef51bdc4c780ca8a5d3a418a51d1483ed5f872 /drivers/gpu | |
| parent | 93abb05fd5d6f3042320ae3c485b034d7c5e8e54 (diff) | |
drm/amd/display: Add switch for Fractional PWM on or off
[Why]
Some LED Driver might not like Fractional PWM especially at extreme
ranges near 0% or 100%.
For example, backlight flashing could be observed.
We want a way to switch fractional PWM on/off either for debug, or
possibly production.
[How]
Add DC code that can send new FW command to enable/disable
fractional PWM.
Signed-off-by: Anthony Koo <Anthony.Koo@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/dc.h | 1 | ||||
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/dce/dce_abm.c | 18 |
2 files changed, 19 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h index dc6a2c236ba7..704e5430d4dc 100644 --- a/drivers/gpu/drm/amd/display/dc/dc.h +++ b/drivers/gpu/drm/amd/display/dc/dc.h @@ -183,6 +183,7 @@ struct dc_config { bool disable_disp_pll_sharing; bool fbc_support; bool optimize_edp_link_rate; + bool disable_fractional_pwm; bool allow_seamless_boot_optimization; }; diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c b/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c index da96229db53a..855360b1414f 100644 --- a/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c +++ b/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c @@ -50,6 +50,7 @@ #define MCP_ABM_LEVEL_SET 0x65 #define MCP_ABM_PIPE_SET 0x66 #define MCP_BL_SET 0x67 +#define MCP_BL_SET_PWM_FRAC 0x6A /* Enable or disable Fractional PWM */ #define MCP_DISABLE_ABM_IMMEDIATELY 255 @@ -390,6 +391,23 @@ static bool dce_abm_init_backlight(struct abm *abm) REG_UPDATE(BL_PWM_GRP1_REG_LOCK, BL_PWM_GRP1_REG_LOCK, 0); + /* Wait until microcontroller is ready to process interrupt */ + REG_WAIT(MASTER_COMM_CNTL_REG, MASTER_COMM_INTERRUPT, 0, 100, 800); + + /* Set PWM fractional enable/disable */ + value = (abm->ctx->dc->config.disable_fractional_pwm == false) ? 1 : 0; + REG_WRITE(MASTER_COMM_DATA_REG1, value); + + /* Set command to enable or disable fractional PWM microcontroller */ + REG_UPDATE(MASTER_COMM_CMD_REG, MASTER_COMM_CMD_REG_BYTE0, + MCP_BL_SET_PWM_FRAC); + + /* Notify microcontroller of new command */ + REG_UPDATE(MASTER_COMM_CNTL_REG, MASTER_COMM_INTERRUPT, 1); + + /* Ensure command has been executed before continuing */ + REG_WAIT(MASTER_COMM_CNTL_REG, MASTER_COMM_INTERRUPT, 0, 100, 800); + return true; } |