[23/26] drm/i915: Do YCbCr 444->420 conversion via DP protocol converters

Commit Message

Ville Syrjälä Feb. 3, 2020, 3:13 p.m. UTC

From: Ville Syrjälä <[e-mail]>

For platforms that can't do native 4:2:0 outout we may still be
able to do it by getting the DP->HDMI protocol converter to
perform the 4:4:4->4:2:0 downsamling for us. In this case we
have to configure our hardware to output YCbCr 4:4:4, which we've
already hooked up so all we need to do is flip the switch.

Signed-off-by: Ville Syrjälä <[e-mail]>
---
 .../drm/i915/display/intel_display_types.h    |   1 +
 drivers/gpu/drm/i915/display/intel_dp.c       | 118 +++++++++++++++---
 drivers/gpu/drm/i915/display/intel_hdmi.c     |   8 +-
 drivers/gpu/drm/i915/display/intel_hdmi.h     |   4 +-
 4 files changed, 106 insertions(+), 25 deletions(-)

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 117fc17dae44..00471791d772 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1310,6 +1310,7 @@  struct intel_dp {
 		int min_tmds_clock, max_tmds_clock;
 		int max_dotclock;
 		u8 max_bpc;
+		bool ycbcr_444_to_420;
 	} dfp;
 };
 
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 639a0c2e5a40..3bf19d691fd5 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -1921,7 +1921,9 @@  static bool intel_dp_supports_dsc(struct intel_dp *intel_dp,
 static bool intel_dp_hdmi_ycbcr420(struct intel_dp *intel_dp,
 				   const struct intel_crtc_state *crtc_state)
 {
-	return crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR420;
+	return crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR420 ||
+		(crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR444 &&
+		 intel_dp->dfp.ycbcr_444_to_420);
 }
 
 static int intel_dp_hdmi_tmds_clock(struct intel_dp *intel_dp,
@@ -1955,9 +1957,10 @@  static bool intel_dp_hdmi_deep_color_possible(struct intel_dp *intel_dp,
 					      const struct intel_crtc_state *crtc_state,
 					      int bpc)
 {
-	bool has_hdmi_sink = intel_dp->has_hdmi_sink;
 
-	return intel_hdmi_deep_color_possible(crtc_state, bpc, has_hdmi_sink) &&
+	return intel_hdmi_deep_color_possible(crtc_state, bpc,
+					      intel_dp->has_hdmi_sink,
+					      intel_dp_hdmi_ycbcr420(intel_dp, crtc_state)) &&
 		intel_dp_hdmi_tmds_clock_valid(intel_dp, crtc_state, bpc);
 }
 
@@ -2368,11 +2371,17 @@  intel_dp_ycbcr420_config(struct intel_dp *intel_dp,
 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
 	int ret;
 
-	if (!drm_mode_is_420_only(info, adjusted_mode) ||
-	    !intel_dp_get_colorimetry_status(intel_dp) ||
-	    !connector->ycbcr_420_allowed)
+	if (!connector->ycbcr_420_allowed)
 		return 0;
 
+	if (!drm_mode_is_420_only(info, adjusted_mode))
+		return 0;
+
+	if (intel_dp->dfp.ycbcr_444_to_420) {
+		crtc_state->output_format = INTEL_OUTPUT_FORMAT_YCBCR444;
+		return 0;
+	}
+
 	crtc_state->output_format = INTEL_OUTPUT_FORMAT_YCBCR420;
 
 	/* YCBCR 420 output conversion needs a scaler */
@@ -3640,11 +3649,24 @@  void intel_dp_configure_protocol_converter(struct intel_dp *intel_dp)
 		DP_HDMI_DVI_OUTPUT_CONFIG : 0;
 
 	if (drm_dp_dpcd_writeb(&intel_dp->aux,
-			       DP_PROTOCOL_CONVERTER_CONTROL_0, tmp) <= 0)
+			       DP_PROTOCOL_CONVERTER_CONTROL_0, tmp) != 1)
 		DRM_DEBUG_KMS("Failed to set protocol converter HDMI mode to %s\n",
 			      enableddisabled(intel_dp->has_hdmi_sink));
 
-	/* TODO: configure YCbCr 4:2:2/4:2:0 conversion */
+	tmp = intel_dp->dfp.ycbcr_444_to_420 ?
+		DP_CONVERSION_TO_YCBCR420_ENABLE : 0;
+
+	if (drm_dp_dpcd_writeb(&intel_dp->aux,
+			       DP_PROTOCOL_CONVERTER_CONTROL_1, tmp) != 1)
+		DRM_DEBUG_KMS("Failed to set protocol converter YCbCr 4:2:0 conversion mode to %s\n",
+			      enableddisabled(intel_dp->dfp.ycbcr_444_to_420));
+
+	tmp = 0;
+
+	if (drm_dp_dpcd_writeb(&intel_dp->aux,
+			       DP_PROTOCOL_CONVERTER_CONTROL_2, tmp) <= 0)
+		DRM_DEBUG_KMS("Failed to set protocol converter YCbCr 4:2:2 conversion mode to %s\n",
+			      enableddisabled(false));
 }
 
 static void intel_enable_dp(struct intel_encoder *encoder,
@@ -5739,14 +5761,10 @@  intel_dp_get_edid(struct intel_dp *intel_dp)
 }
 
 static void
-intel_dp_set_edid(struct intel_dp *intel_dp)
+intel_dp_update_dfp(struct intel_dp *intel_dp,
+		    const struct edid *edid)
 {
 	struct intel_connector *connector = intel_dp->attached_connector;
-	struct edid *edid;
-
-	intel_dp_unset_edid(intel_dp);
-	edid = intel_dp_get_edid(intel_dp);
-	connector->detect_edid = edid;
 
 	intel_dp->dfp.max_bpc =
 		drm_dp_downstream_max_bpc(intel_dp->dpcd,
@@ -5771,6 +5789,66 @@  intel_dp_set_edid(struct intel_dp *intel_dp)
 		      intel_dp->dfp.max_dotclock,
 		      intel_dp->dfp.min_tmds_clock,
 		      intel_dp->dfp.max_tmds_clock);
+}
+
+static void
+intel_dp_update_420(struct intel_dp *intel_dp)
+{
+	struct intel_connector *connector = intel_dp->attached_connector;
+	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
+	bool is_branch, ycbcr_420_passthrough, ycbcr_444_to_420;
+
+	/* No YCbCr output support on gmch platforms */
+	if (HAS_GMCH(dev_priv))
+		return;
+
+	/*
+	 * ILK doesn't seem capable of DP YCbCr output. The
+	 * displayed image is severly corrupted. SNB+ is fine.
+	 */
+	if (IS_GEN(dev_priv, 5))
+		return;
+
+	is_branch = drm_dp_is_branch(intel_dp->dpcd);
+	ycbcr_420_passthrough =
+		drm_dp_downstream_420_passthrough(intel_dp->dpcd,
+						  intel_dp->downstream_ports);
+	ycbcr_444_to_420 =
+		drm_dp_downstream_444_to_420_conversion(intel_dp->dpcd,
+							intel_dp->downstream_ports);
+
+	if (INTEL_GEN(dev_priv) >= 11) {
+		/* Prefer 4:2:0 passthrough over 4:4:4->4:2:0 conversion */
+		intel_dp->dfp.ycbcr_444_to_420 =
+			ycbcr_444_to_420 && !ycbcr_420_passthrough;
+
+		connector->base.ycbcr_420_allowed =
+			!is_branch || ycbcr_444_to_420 || ycbcr_420_passthrough;
+	} else {
+		/* 4:4:4->4:2:0 conversion is the only way */
+		intel_dp->dfp.ycbcr_444_to_420 = ycbcr_444_to_420;
+
+		connector->base.ycbcr_420_allowed = ycbcr_444_to_420;
+	}
+
+	DRM_DEBUG_KMS("[CONNECTOR:%d:%s] YCbCr 4:2:0 allowed? %s, YCbCr 4:4:4->4:2:0 conversion? %s\n",
+		      connector->base.base.id, connector->base.name,
+		      yesno(connector->base.ycbcr_420_allowed),
+		      yesno(intel_dp->dfp.ycbcr_444_to_420));
+}
+
+static void
+intel_dp_set_edid(struct intel_dp *intel_dp)
+{
+	struct intel_connector *connector = intel_dp->attached_connector;
+	struct edid *edid;
+
+	intel_dp_unset_edid(intel_dp);
+	edid = intel_dp_get_edid(intel_dp);
+	connector->detect_edid = edid;
+
+	intel_dp_update_dfp(intel_dp, edid);
+	intel_dp_update_420(intel_dp);
 
 	if (edid && edid->input & DRM_EDID_INPUT_DIGITAL) {
 		intel_dp->has_hdmi_sink = drm_detect_hdmi_monitor(edid);
@@ -5783,11 +5861,11 @@  intel_dp_set_edid(struct intel_dp *intel_dp)
 static void
 intel_dp_unset_edid(struct intel_dp *intel_dp)
 {
-	struct intel_connector *intel_connector = intel_dp->attached_connector;
+	struct intel_connector *connector = intel_dp->attached_connector;
 
 	drm_dp_cec_unset_edid(&intel_dp->aux);
-	kfree(intel_connector->detect_edid);
-	intel_connector->detect_edid = NULL;
+	kfree(connector->detect_edid);
+	connector->detect_edid = NULL;
 
 	intel_dp->has_hdmi_sink = false;
 	intel_dp->has_audio = false;
@@ -5796,6 +5874,9 @@  intel_dp_unset_edid(struct intel_dp *intel_dp)
 	intel_dp->dfp.max_dotclock = 0;
 	intel_dp->dfp.min_tmds_clock = 0;
 	intel_dp->dfp.max_tmds_clock = 0;
+
+	intel_dp->dfp.ycbcr_444_to_420 = false;
+	connector->base.ycbcr_420_allowed = false;
 }
 
 static int
@@ -7703,9 +7784,6 @@  intel_dp_init_connector(struct intel_digital_port *intel_dig_port,
 		connector->interlace_allowed = true;
 	connector->doublescan_allowed = 0;
 
-	if (INTEL_GEN(dev_priv) >= 11)
-		connector->ycbcr_420_allowed = true;
-
 	intel_encoder->hpd_pin = intel_hpd_pin_default(dev_priv, port);
 
 	intel_dp_aux_init(intel_dp);
diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
index d6326a4a4a9a..9e0316f6eb3f 100644
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -2219,7 +2219,7 @@  intel_hdmi_mode_valid(struct drm_connector *connector,
 }
 
 bool intel_hdmi_deep_color_possible(const struct intel_crtc_state *crtc_state,
-				    int bpc, bool has_hdmi_sink)
+				    int bpc, bool has_hdmi_sink, bool ycbcr420_output)
 {
 	struct drm_atomic_state *state = crtc_state->uapi.state;
 	struct drm_connector_state *connector_state;
@@ -2238,7 +2238,7 @@  bool intel_hdmi_deep_color_possible(const struct intel_crtc_state *crtc_state,
 		if (connector_state->crtc != crtc_state->uapi.crtc)
 			continue;
 
-		if (crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR420) {
+		if (ycbcr420_output) {
 			const struct drm_hdmi_info *hdmi = &info->hdmi;
 
 			if (bpc == 12 && !(hdmi->y420_dc_modes &
@@ -2289,7 +2289,9 @@  static bool hdmi_deep_color_possible(const struct intel_crtc_state *crtc_state,
 		return false;
 
 	return intel_hdmi_deep_color_possible(crtc_state, bpc,
-					      crtc_state->has_hdmi_sink);
+					      crtc_state->has_hdmi_sink,
+					      crtc_state->output_format ==
+					      INTEL_OUTPUT_FORMAT_YCBCR420);
 }
 
 static bool
diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.h b/drivers/gpu/drm/i915/display/intel_hdmi.h
index bd58c929f816..52cea8beafbb 100644
--- a/drivers/gpu/drm/i915/display/intel_hdmi.h
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.h
@@ -48,7 +48,7 @@  void intel_read_infoframe(struct intel_encoder *encoder,
 			  const struct intel_crtc_state *crtc_state,
 			  enum hdmi_infoframe_type type,
 			  union hdmi_infoframe *frame);
-bool intel_hdmi_deep_color_possible(const struct intel_crtc_state *crtc_state,
-				    int bpc, bool has_hdmi_sink);
+bool intel_hdmi_deep_color_possible(const struct intel_crtc_state *crtc_state, int bpc,
+				    bool has_hdmi_sink, bool ycbcr420_output);
 
 #endif /* __INTEL_HDMI_H__ */