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.
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 | 42 ++++++++++++++++++++++----- 3 files changed, 41 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c index 3758ae1f11b4..ce033d58134e 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 = false, };
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:false)"); diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h index ac02efce6e22..2de3e2850b54 100644 --- a/drivers/gpu/drm/i915/i915_params.h +++ b/drivers/gpu/drm/i915/i915_params.h @@ -67,7 +67,8 @@ func(bool, nuclear_pageflip); \ func(bool, enable_dp_mst); \ func(int, enable_dpcd_backlight); \ - 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 c89aae804659..f55af41ce3bd 100644 --- a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c +++ b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c @@ -100,11 +100,26 @@ intel_dp_aux_set_backlight(struct intel_connector *connector, u32 level) } }
+/* + * Set minimum / maximum dynamic brightness percentage. This value is expressed + * as the percentage of normal brightness in 5% increments. + */ +static void +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"); + } +} + static void intel_dp_aux_enable_backlight(struct intel_connector *connector) { struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base); - uint8_t dpcd_buf = 0; - uint8_t edp_backlight_mode = 0; + uint8_t dpcd_buf, new_dpcd_buf, edp_backlight_mode;
if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &dpcd_buf) != 1) { @@ -113,18 +128,15 @@ static void intel_dp_aux_enable_backlight(struct intel_connector *connector) return; }
+ new_dpcd_buf = dpcd_buf; edp_backlight_mode = dpcd_buf & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK;
switch (edp_backlight_mode) { case DP_EDP_BACKLIGHT_CONTROL_MODE_PWM: case DP_EDP_BACKLIGHT_CONTROL_MODE_PRESET: case DP_EDP_BACKLIGHT_CONTROL_MODE_PRODUCT: - dpcd_buf &= ~DP_EDP_BACKLIGHT_CONTROL_MODE_MASK; - dpcd_buf |= DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD; - if (drm_dp_dpcd_writeb(&intel_dp->aux, - DP_EDP_BACKLIGHT_MODE_SET_REGISTER, dpcd_buf) < 0) { - DRM_DEBUG_KMS("Failed to write aux backlight mode\n"); - } + new_dpcd_buf &= ~DP_EDP_BACKLIGHT_CONTROL_MODE_MASK; + new_dpcd_buf |= DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD; break;
/* Do nothing when it is already DPCD mode */ @@ -133,6 +145,20 @@ static void intel_dp_aux_enable_backlight(struct intel_connector *connector) break; }
+ if (i915.enable_dbc && + (intel_dp->edp_dpcd[2] & DP_EDP_DYNAMIC_BACKLIGHT_CAP)) { + new_dpcd_buf |= DP_EDP_DYNAMIC_BACKLIGHT_ENABLE; + intel_dp_aux_set_dynamic_backlight_percent(intel_dp, 0, 100); + 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) { + DRM_DEBUG_KMS("Failed to write aux backlight mode\n"); + } + } + set_aux_backlight_enable(intel_dp, true); intel_dp_aux_set_backlight(connector, connector->panel.backlight.level); }