drm/i915: Pass the current pipe from eDP init to backlight setup

On VLV/CHV both pipes A and B have their own backlight control
registers. In order to correctly read out the current hardware state at
init we need to know which pipe is driving the eDP port. Pass that
information down from the eDP init code into the backlight code.

To determine the correct pipe we first look at which pipe is currently
configured in the port control register, if that look invalid we look
at which pipe's PPS is currently controlling the port, and if that
too looks invalid we just assume pipe A.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -510,7 +510,7 @@ struct drm_i915_display_funcs {
 	/* display clock increase/decrease */
 	/* pll clock increase/decrease */
 
-	int (*setup_backlight)(struct intel_connector *connector);
+	int (*setup_backlight)(struct intel_connector *connector, enum pipe pipe);
 	uint32_t (*get_backlight)(struct intel_connector *connector);
 	void (*set_backlight)(struct intel_connector *connector,
 			      uint32_t level);

drivers/gpu/drm/i915/intel_dp.c

@@ -5212,6 +5212,7 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
 	bool has_dpcd;
 	struct drm_display_mode *scan;
 	struct edid *edid;
+	enum pipe pipe = INVALID_PIPE;
 
 	intel_dp->drrs_state.type = DRRS_NOT_SUPPORTED;
 
@@ -5280,11 +5281,30 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
 	if (IS_VALLEYVIEW(dev)) {
 		intel_dp->edp_notifier.notifier_call = edp_notify_handler;
 		register_reboot_notifier(&intel_dp->edp_notifier);
+
+		/*
+		 * Figure out the current pipe for the initial backlight setup.
+		 * If the current pipe isn't valid, try the PPS pipe, and if that
+		 * fails just assume pipe A.
+		 */
+		if (IS_CHERRYVIEW(dev))
+			pipe = DP_PORT_TO_PIPE_CHV(intel_dp->DP);
+		else
+			pipe = PORT_TO_PIPE(intel_dp->DP);
+
+		if (pipe != PIPE_A && pipe != PIPE_B)
+			pipe = intel_dp->pps_pipe;
+
+		if (pipe != PIPE_A && pipe != PIPE_B)
+			pipe = PIPE_A;
+
+		DRM_DEBUG_KMS("using pipe %c for initial backlight setup\n",
+			      pipe_name(pipe));
 	}
 
 	intel_panel_init(&intel_connector->panel, fixed_mode, downclock_mode);
 	intel_connector->panel.backlight_power = intel_edp_backlight_power;
-	intel_panel_setup_backlight(connector);
+	intel_panel_setup_backlight(connector, pipe);
 
 	return true;
 }

drivers/gpu/drm/i915/intel_drv.h

@@ -1096,7 +1096,7 @@ void intel_gmch_panel_fitting(struct intel_crtc *crtc,
 			      int fitting_mode);
 void intel_panel_set_backlight_acpi(struct intel_connector *connector,
 				    u32 level, u32 max);
-int intel_panel_setup_backlight(struct drm_connector *connector);
+int intel_panel_setup_backlight(struct drm_connector *connector, enum pipe pipe);
 void intel_panel_enable_backlight(struct intel_connector *connector);
 void intel_panel_disable_backlight(struct intel_connector *connector);
 void intel_panel_destroy_backlight(struct drm_connector *connector);

drivers/gpu/drm/i915/intel_lvds.c

@@ -1116,7 +1116,7 @@ void intel_lvds_init(struct drm_device *dev)
 	drm_connector_register(connector);
 
 	intel_panel_init(&intel_connector->panel, fixed_mode, downclock_mode);
-	intel_panel_setup_backlight(connector);
+	intel_panel_setup_backlight(connector, INVALID_PIPE);
 
 	return;
 

drivers/gpu/drm/i915/intel_panel.c

@@ -1117,7 +1117,7 @@ static u32 get_backlight_min_vbt(struct intel_connector *connector)
 		     0, panel->backlight.max);
 }
 
-static int bdw_setup_backlight(struct intel_connector *connector)
+static int bdw_setup_backlight(struct intel_connector *connector, enum pipe unused)
 {
 	struct drm_device *dev = connector->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -1143,7 +1143,7 @@ static int bdw_setup_backlight(struct intel_connector *connector)
 	return 0;
 }
 
-static int pch_setup_backlight(struct intel_connector *connector)
+static int pch_setup_backlight(struct intel_connector *connector, enum pipe unused)
 {
 	struct drm_device *dev = connector->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -1170,7 +1170,7 @@ static int pch_setup_backlight(struct intel_connector *connector)
 	return 0;
 }
 
-static int i9xx_setup_backlight(struct intel_connector *connector)
+static int i9xx_setup_backlight(struct intel_connector *connector, enum pipe unused)
 {
 	struct drm_device *dev = connector->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -1202,7 +1202,7 @@ static int i9xx_setup_backlight(struct intel_connector *connector)
 	return 0;
 }
 
-static int i965_setup_backlight(struct intel_connector *connector)
+static int i965_setup_backlight(struct intel_connector *connector, enum pipe unused)
 {
 	struct drm_device *dev = connector->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -1232,37 +1232,40 @@ static int i965_setup_backlight(struct intel_connector *connector)
 	return 0;
 }
 
-static int vlv_setup_backlight(struct intel_connector *connector)
+static int vlv_setup_backlight(struct intel_connector *connector, enum pipe pipe)
 {
 	struct drm_device *dev = connector->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_panel *panel = &connector->panel;
-	enum pipe pipe;
+	enum pipe p;
 	u32 ctl, ctl2, val;
 
-	for_each_pipe(dev_priv, pipe) {
-		u32 cur_val = I915_READ(VLV_BLC_PWM_CTL(pipe));
+	for_each_pipe(dev_priv, p) {
+		u32 cur_val = I915_READ(VLV_BLC_PWM_CTL(p));
 
 		/* Skip if the modulation freq is already set */
 		if (cur_val & ~BACKLIGHT_DUTY_CYCLE_MASK)
 			continue;
 
 		cur_val &= BACKLIGHT_DUTY_CYCLE_MASK;
-		I915_WRITE(VLV_BLC_PWM_CTL(pipe), (0xf42 << 16) |
+		I915_WRITE(VLV_BLC_PWM_CTL(p), (0xf42 << 16) |
 			   cur_val);
 	}
 
-	ctl2 = I915_READ(VLV_BLC_PWM_CTL2(PIPE_A));
+	if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
+		return -ENODEV;
+
+	ctl2 = I915_READ(VLV_BLC_PWM_CTL2(pipe));
 	panel->backlight.active_low_pwm = ctl2 & BLM_POLARITY_I965;
 
-	ctl = I915_READ(VLV_BLC_PWM_CTL(PIPE_A));
+	ctl = I915_READ(VLV_BLC_PWM_CTL(pipe));
 	panel->backlight.max = ctl >> 16;
 	if (!panel->backlight.max)
 		return -ENODEV;
 
 	panel->backlight.min = get_backlight_min_vbt(connector);
 
-	val = _vlv_get_backlight(dev, PIPE_A);
+	val = _vlv_get_backlight(dev, pipe);
 	panel->backlight.level = intel_panel_compute_brightness(connector, val);
 
 	panel->backlight.enabled = (ctl2 & BLM_PWM_ENABLE) &&
@@ -1271,7 +1274,7 @@ static int vlv_setup_backlight(struct intel_connector *connector)
 	return 0;
 }
 
-int intel_panel_setup_backlight(struct drm_connector *connector)
+int intel_panel_setup_backlight(struct drm_connector *connector, enum pipe pipe)
 {
 	struct drm_device *dev = connector->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -1290,7 +1293,7 @@ int intel_panel_setup_backlight(struct drm_connector *connector)
 
 	/* set level and max in panel struct */
 	mutex_lock(&dev_priv->backlight_lock);
-	ret = dev_priv->display.setup_backlight(intel_connector);
+	ret = dev_priv->display.setup_backlight(intel_connector, pipe);
 	mutex_unlock(&dev_priv->backlight_lock);
 
 	if (ret) {