Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit ae25ecea authored by Puthikorn Voravootivat's avatar Puthikorn Voravootivat Committed by Daniel Vetter
Browse files

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: default avatarPuthikorn Voravootivat <puthik@chromium.org>
Reviewed-by: default avatarDhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170622190339.142671-4-puthik@chromium.org
parent 560a758d

drivers/gpu/drm/i915/i915_params.c

+5 −0
Original line number Diff line number Diff line
@@ -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)");

drivers/gpu/drm/i915/i915_params.h

+2 −1
Original line number Diff line number Diff line
@@ -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 {

drivers/gpu/drm/i915/intel_dp_aux_backlight.c

+26 −0
Original line number Diff line number Diff line
@@ -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) {