This patch adds option to enable dynamic backlight for eDP panel that supports this feature via DPCD register and set minimum / maximum brightness to 0% and 100% of the normal brightness.
Change-Id: I52f04b814bb4cd9df570ab59094ae974b9baec5b Signed-off-by: Puthikorn Voravootivat puthik@chromium.org --- drivers/gpu/drm/i915/i915_params.c | 5 +++++ drivers/gpu/drm/i915/i915_params.h | 3 ++- drivers/gpu/drm/i915/intel_dp_aux_backlight.c | 26 ++++++++++++++++++++++++++ 3 files changed, 33 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c index 3758ae1f11b4..d84042ddf1fc 100644 --- a/drivers/gpu/drm/i915/i915_params.c +++ b/drivers/gpu/drm/i915/i915_params.c @@ -65,6 +65,7 @@ struct i915_params i915 __read_mostly = { .inject_load_failure = 0, .enable_dpcd_backlight = -1, .enable_gvt = false, + .enable_dbc = true, };
module_param_named(modeset, i915.modeset, int, 0400); @@ -254,3 +255,7 @@ MODULE_PARM_DESC(enable_dpcd_backlight, module_param_named(enable_gvt, i915.enable_gvt, bool, 0400); MODULE_PARM_DESC(enable_gvt, "Enable support for Intel GVT-g graphics virtualization host support(default:false)"); + +module_param_named_unsafe(enable_dbc, i915.enable_dbc, bool, 0600); +MODULE_PARM_DESC(enable_dbc, + "Enable support for dynamic backlight control (default:true)"); diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h index 643dfaf41c1f..99f68d853c18 100644 --- a/drivers/gpu/drm/i915/i915_params.h +++ b/drivers/gpu/drm/i915/i915_params.h @@ -67,7 +67,8 @@ func(bool, verbose_state_checks); \ func(bool, nuclear_pageflip); \ func(bool, enable_dp_mst); \ - func(bool, enable_gvt) + func(bool, enable_gvt); \ + func(bool, enable_dbc)
#define MEMBER(T, member) T member struct i915_params { diff --git a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c index b73b3d431a82..b2f4cc975a3e 100644 --- a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c +++ b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c @@ -172,6 +172,24 @@ static bool intel_dp_aux_set_pwm_freq(struct intel_connector *connector) return true; }
+/* +* Set minimum / maximum dynamic brightness percentage. This value is expressed +* as the percentage of normal brightness in 5% increments. +*/ +static bool +intel_dp_aux_set_dynamic_backlight_percent(struct intel_dp *intel_dp, + u32 min, u32 max) +{ + u8 dbc[] = { DIV_ROUND_CLOSEST(min, 5), DIV_ROUND_CLOSEST(max, 5) }; + + if (drm_dp_dpcd_write(&intel_dp->aux, DP_EDP_DBC_MINIMUM_BRIGHTNESS_SET, + dbc, sizeof(dbc)) < 0) { + DRM_DEBUG_KMS("Failed to write aux DBC brightness level\n"); + return false; + } + return true; +} + static void intel_dp_aux_enable_backlight(struct intel_connector *connector) { struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base); @@ -205,6 +223,14 @@ static void intel_dp_aux_enable_backlight(struct intel_connector *connector) if (intel_dp_aux_set_pwm_freq(connector)) new_dpcd_buf |= DP_EDP_BACKLIGHT_FREQ_AUX_SET_ENABLE;
+ if (i915.enable_dbc && + (intel_dp->edp_dpcd[2] & DP_EDP_DYNAMIC_BACKLIGHT_CAP)) { + if(intel_dp_aux_set_dynamic_backlight_percent(intel_dp, 0, 100)) { + new_dpcd_buf |= DP_EDP_DYNAMIC_BACKLIGHT_ENABLE; + DRM_DEBUG_KMS("Enable dynamic brightness.\n"); + } + } + if (new_dpcd_buf != dpcd_buf) { if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, new_dpcd_buf) < 0) {