drm/i915/icl: Add 10-bit support for hdmi

Starting Icelake silicon supports 10-bpc hdmi to support certain
media workloads. Currently hdmi supports 8 and 12 bpc. Plumbed
in support for 10 bit hdmi.

Cc: James Ausmus <james.ausmus@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180522002558.29262-18-paulo.r.zanoni@intel.com

drivers/gpu/drm/i915/intel_hdmi.c

@@ -1566,14 +1566,23 @@ intel_hdmi_mode_valid(struct drm_connector *connector,
 	/* check if we can do 8bpc */
 	status = hdmi_port_clock_valid(hdmi, clock, true, force_dvi);
 
-	/* if we can't do 8bpc we may still be able to do 12bpc */
-	if (!HAS_GMCH_DISPLAY(dev_priv) && status != MODE_OK && hdmi->has_hdmi_sink && !force_dvi)
-		status = hdmi_port_clock_valid(hdmi, clock * 3 / 2, true, force_dvi);
+	if (hdmi->has_hdmi_sink && !force_dvi) {
+		/* if we can't do 8bpc we may still be able to do 12bpc */
+		if (status != MODE_OK && !HAS_GMCH_DISPLAY(dev_priv))
+			status = hdmi_port_clock_valid(hdmi, clock * 3 / 2,
+						       true, force_dvi);
+
+		/* if we can't do 8,12bpc we may still be able to do 10bpc */
+		if (status != MODE_OK && INTEL_GEN(dev_priv) >= 11)
+			status = hdmi_port_clock_valid(hdmi, clock * 5 / 4,
+						       true, force_dvi);
+	}
 
 	return status;
 }
 
-static bool hdmi_12bpc_possible(const struct intel_crtc_state *crtc_state)
+static bool hdmi_deep_color_possible(const struct intel_crtc_state *crtc_state,
+				     int bpc)
 {
 	struct drm_i915_private *dev_priv =
 		to_i915(crtc_state->base.crtc->dev);
@@ -1585,6 +1594,9 @@ static bool hdmi_12bpc_possible(const struct intel_crtc_state *crtc_state)
 	if (HAS_GMCH_DISPLAY(dev_priv))
 		return false;
 
+	if (bpc == 10 && INTEL_GEN(dev_priv) < 11)
+		return false;
+
 	if (crtc_state->pipe_bpp <= 8*3)
 		return false;
 
@@ -1592,7 +1604,7 @@ static bool hdmi_12bpc_possible(const struct intel_crtc_state *crtc_state)
 		return false;
 
 	/*
-	 * HDMI 12bpc affects the clocks, so it's only possible
+	 * HDMI deep color affects the clocks, so it's only possible
 	 * when not cloning with other encoder types.
 	 */
 	if (crtc_state->output_types != 1 << INTEL_OUTPUT_HDMI)
@@ -1607,16 +1619,24 @@ static bool hdmi_12bpc_possible(const struct intel_crtc_state *crtc_state)
 		if (crtc_state->ycbcr420) {
 			const struct drm_hdmi_info *hdmi = &info->hdmi;
 
-			if (!(hdmi->y420_dc_modes & DRM_EDID_YCBCR420_DC_36))
+			if (bpc == 12 && !(hdmi->y420_dc_modes &
+					   DRM_EDID_YCBCR420_DC_36))
+				return false;
+			else if (bpc == 10 && !(hdmi->y420_dc_modes &
+						DRM_EDID_YCBCR420_DC_30))
 				return false;
 		} else {
-			if (!(info->edid_hdmi_dc_modes & DRM_EDID_HDMI_DC_36))
+			if (bpc == 12 && !(info->edid_hdmi_dc_modes &
+					   DRM_EDID_HDMI_DC_36))
+				return false;
+			else if (bpc == 10 && !(info->edid_hdmi_dc_modes &
+						DRM_EDID_HDMI_DC_30))
 				return false;
 		}
 	}
 
 	/* Display WA #1139: glk */
-	if (IS_GLK_REVID(dev_priv, 0, GLK_REVID_A1) &&
+	if (bpc == 12 && IS_GLK_REVID(dev_priv, 0, GLK_REVID_A1) &&
 	    crtc_state->base.adjusted_mode.htotal > 5460)
 		return false;
 
@@ -1626,7 +1646,8 @@ static bool hdmi_12bpc_possible(const struct intel_crtc_state *crtc_state)
 static bool
 intel_hdmi_ycbcr420_config(struct drm_connector *connector,
 			   struct intel_crtc_state *config,
-			   int *clock_12bpc, int *clock_8bpc)
+			   int *clock_12bpc, int *clock_10bpc,
+			   int *clock_8bpc)
 {
 	struct intel_crtc *intel_crtc = to_intel_crtc(config->base.crtc);
 
@@ -1638,6 +1659,7 @@ intel_hdmi_ycbcr420_config(struct drm_connector *connector,
 	/* YCBCR420 TMDS rate requirement is half the pixel clock */
 	config->port_clock /= 2;
 	*clock_12bpc /= 2;
+	*clock_10bpc /= 2;
 	*clock_8bpc /= 2;
 	config->ycbcr420 = true;
 
@@ -1665,6 +1687,7 @@ bool intel_hdmi_compute_config(struct intel_encoder *encoder,
 	struct intel_digital_connector_state *intel_conn_state =
 		to_intel_digital_connector_state(conn_state);
 	int clock_8bpc = pipe_config->base.adjusted_mode.crtc_clock;
+	int clock_10bpc = clock_8bpc * 5 / 4;
 	int clock_12bpc = clock_8bpc * 3 / 2;
 	int desired_bpp;
 	bool force_dvi = intel_conn_state->force_audio == HDMI_AUDIO_OFF_DVI;
@@ -1691,12 +1714,14 @@ bool intel_hdmi_compute_config(struct intel_encoder *encoder,
 	if (adjusted_mode->flags & DRM_MODE_FLAG_DBLCLK) {
 		pipe_config->pixel_multiplier = 2;
 		clock_8bpc *= 2;
+		clock_10bpc *= 2;
 		clock_12bpc *= 2;
 	}
 
 	if (drm_mode_is_420_only(&connector->display_info, adjusted_mode)) {
 		if (!intel_hdmi_ycbcr420_config(connector, pipe_config,
-						&clock_12bpc, &clock_8bpc)) {
+						&clock_12bpc, &clock_10bpc,
+						&clock_8bpc)) {
 			DRM_ERROR("Can't support YCBCR420 output\n");
 			return false;
 		}
@@ -1714,18 +1739,25 @@ bool intel_hdmi_compute_config(struct intel_encoder *encoder,
 	}
 
 	/*
-	 * HDMI is either 12 or 8, so if the display lets 10bpc sneak
-	 * through, clamp it down. Note that g4x/vlv don't support 12bpc hdmi
-	 * outputs. We also need to check that the higher clock still fits
-	 * within limits.
+	 * Note that g4x/vlv don't support 12bpc hdmi outputs. We also need
+	 * to check that the higher clock still fits within limits.
 	 */
-	if (hdmi_12bpc_possible(pipe_config) &&
-	    hdmi_port_clock_valid(intel_hdmi, clock_12bpc, true, force_dvi) == MODE_OK) {
+	if (hdmi_deep_color_possible(pipe_config, 12) &&
+	    hdmi_port_clock_valid(intel_hdmi, clock_12bpc,
+				  true, force_dvi) == MODE_OK) {
 		DRM_DEBUG_KMS("picking bpc to 12 for HDMI output\n");
 		desired_bpp = 12*3;
 
 		/* Need to adjust the port link by 1.5x for 12bpc. */
 		pipe_config->port_clock = clock_12bpc;
+	} else if (hdmi_deep_color_possible(pipe_config, 10) &&
+		   hdmi_port_clock_valid(intel_hdmi, clock_10bpc,
+					 true, force_dvi) == MODE_OK) {
+		DRM_DEBUG_KMS("picking bpc to 10 for HDMI output\n");
+		desired_bpp = 10 * 3;
+
+		/* Need to adjust the port link by 1.25x for 10bpc. */
+		pipe_config->port_clock = clock_10bpc;
 	} else {
 		DRM_DEBUG_KMS("picking bpc to 8 for HDMI output\n");
 		desired_bpp = 8*3;