drm/i915: Enable/disable DRRS

Calling enable/disable DRRS when enable/disable DDI are called.
These functions are responsible for setup of drrs data (in enable) and
reset of drrs (in disable).
has_drrs is true when downclock_mode is found and SEAMLESS_DRRS is set in
the VBT. A check has been added for has_drrs in these functions, to make
sure the functions go through only if DRRS will work on the platform with
the attached panel.

V2: [By Ram]: WARN_ON is used when intel_edp_drrs_enable() is called more than
once [Rodrigo]
Signed-off-by: Vandana Kannan <vandana.kannan@intel.com>
Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_ddi.c

@@ -1610,6 +1610,7 @@ static void intel_enable_ddi(struct intel_encoder *intel_encoder)
 
 		intel_edp_backlight_on(intel_dp);
 		intel_psr_enable(intel_dp);
+		intel_edp_drrs_enable(intel_dp);
 	}
 
 	if (intel_crtc->config->has_audio) {
@@ -1635,6 +1636,7 @@ static void intel_disable_ddi(struct intel_encoder *intel_encoder)
 	if (type == INTEL_OUTPUT_EDP) {
 		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
 
+		intel_edp_drrs_disable(intel_dp);
 		intel_psr_disable(intel_dp);
 		intel_edp_backlight_off(intel_dp);
 	}

drivers/gpu/drm/i915/intel_dp.c

@@ -4822,6 +4822,61 @@ static void intel_dp_set_drrs_state(struct drm_device *dev, int refresh_rate)
 	DRM_DEBUG_KMS("eDP Refresh Rate set to : %dHz\n", refresh_rate);
 }
 
+void intel_edp_drrs_enable(struct intel_dp *intel_dp)
+{
+	struct drm_device *dev = intel_dp_to_dev(intel_dp);
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
+	struct drm_crtc *crtc = dig_port->base.base.crtc;
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+
+	if (!intel_crtc->config->has_drrs) {
+		DRM_DEBUG_KMS("Panel doesn't support DRRS\n");
+		return;
+	}
+
+	mutex_lock(&dev_priv->drrs.mutex);
+	if (WARN_ON(dev_priv->drrs.dp)) {
+		DRM_ERROR("DRRS already enabled\n");
+		goto unlock;
+	}
+
+	dev_priv->drrs.busy_frontbuffer_bits = 0;
+
+	dev_priv->drrs.dp = intel_dp;
+
+unlock:
+	mutex_unlock(&dev_priv->drrs.mutex);
+}
+
+void intel_edp_drrs_disable(struct intel_dp *intel_dp)
+{
+	struct drm_device *dev = intel_dp_to_dev(intel_dp);
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
+	struct drm_crtc *crtc = dig_port->base.base.crtc;
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+
+	if (!intel_crtc->config->has_drrs)
+		return;
+
+	mutex_lock(&dev_priv->drrs.mutex);
+	if (!dev_priv->drrs.dp) {
+		mutex_unlock(&dev_priv->drrs.mutex);
+		return;
+	}
+
+	if (dev_priv->drrs.refresh_rate_type == DRRS_LOW_RR)
+		intel_dp_set_drrs_state(dev_priv->dev,
+			intel_dp->attached_connector->panel.
+			fixed_mode->vrefresh);
+
+	dev_priv->drrs.dp = NULL;
+	mutex_unlock(&dev_priv->drrs.mutex);
+
+	cancel_delayed_work_sync(&dev_priv->drrs.work);
+}
+
 static void intel_edp_drrs_downclock_work(struct work_struct *work)
 {
 	struct drm_i915_private *dev_priv =

drivers/gpu/drm/i915/intel_drv.h

@@ -1030,6 +1030,8 @@ int intel_update_plane(struct drm_plane *plane, struct drm_crtc *crtc,
 		       uint32_t src_w, uint32_t src_h);
 int intel_disable_plane(struct drm_plane *plane);
 void intel_plane_destroy(struct drm_plane *plane);
+void intel_edp_drrs_enable(struct intel_dp *intel_dp);
+void intel_edp_drrs_disable(struct intel_dp *intel_dp);
 
 /* intel_dp_mst.c */
 int intel_dp_mst_encoder_init(struct intel_digital_port *intel_dig_port, int conn_id);