From ae25eceab616d16a07bcaa434b84463d58a3bdc3 Mon Sep 17 00:00:00 2001 From: Puthikorn Voravootivat Date: Thu, 22 Jun 2017 12:03:39 -0700 Subject: [PATCH] drm/i915: Add option to support dynamic backlight via DPCD 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 Reviewed-by: Dhinakaran Pandiyan Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20170622190339.142671-4-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 5b5ab15d191f..88b9d3e6713a 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 0d6cf9138dc4..057e203e6bda 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 fea161727c6e..b25cd88fc1c5 100644 --- a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c +++ b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c @@ -173,6 +173,24 @@ 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(const struct intel_crtc_state *crtc_state, const struct drm_connector_state *conn_state) { @@ -208,6 +226,14 @@ static void intel_dp_aux_enable_backlight(const struct intel_crtc_state *crtc_st 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) { -- 2.20.1