[PATCH v11 08/22] drm/i915: Implement the "color format" DRM property

[Nicolas Frattaroli <nicolas.frattaroli@collabora.com>]

This includes RGB, YUV420, YUV444 and Auto. Auto will pick RGB, unless
the mode being asked for is YUV420-only, in which case it picks YUV420.

Should the explicitly requested color format not be supported by the
sink, then an error is returned to userspace, so that it can make a
better choice.

Co-developed-by: Werner Sembach <wse@tuxedocomputers.com>
Signed-off-by: Werner Sembach <wse@tuxedocomputers.com>
Co-developed-by: Andri Yngvason <andri@yngvason.is>
Signed-off-by: Andri Yngvason <andri@yngvason.is>
Co-developed-by: Marius Vlad <marius.vlad@collabora.com>
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
---
 drivers/gpu/drm/i915/display/intel_connector.c | 10 ++++
 drivers/gpu/drm/i915/display/intel_connector.h |  1 +
 drivers/gpu/drm/i915/display/intel_dp.c        | 71 ++++++++++++++++++++-----
 drivers/gpu/drm/i915/display/intel_dp.h        |  4 ++
 drivers/gpu/drm/i915/display/intel_dp_mst.c    | 52 ++++++++++++++++++-
 drivers/gpu/drm/i915/display/intel_hdmi.c      | 72 ++++++++++++++++++++------
 6 files changed, 181 insertions(+), 29 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_connector.c b/drivers/gpu/drm/i915/display/intel_connector.c
index 7ef9338d67ab..d54ae1522b6f 100644
--- a/drivers/gpu/drm/i915/display/intel_connector.c
+++ b/drivers/gpu/drm/i915/display/intel_connector.c
@@ -38,6 +38,10 @@
 #include "intel_hdcp.h"
 #include "intel_panel.h"
 
+static const u32 supported_colorformats = BIT(DRM_OUTPUT_COLOR_FORMAT_RGB444) |
+					  BIT(DRM_OUTPUT_COLOR_FORMAT_YCBCR444) |
+					  BIT(DRM_OUTPUT_COLOR_FORMAT_YCBCR420);
+
 static void intel_connector_modeset_retry_work_fn(struct work_struct *work)
 {
 	struct intel_connector *connector = container_of(work, typeof(*connector),
@@ -321,6 +325,12 @@ intel_attach_dp_colorspace_property(struct drm_connector *connector)
 		drm_connector_attach_colorspace_property(connector);
 }
 
+void
+intel_attach_colorformat_property(struct drm_connector *connector)
+{
+	drm_connector_attach_color_format_property(connector, supported_colorformats);
+}
+
 void
 intel_attach_scaling_mode_property(struct drm_connector *connector)
 {
diff --git a/drivers/gpu/drm/i915/display/intel_connector.h b/drivers/gpu/drm/i915/display/intel_connector.h
index 0aa86626e646..fe6149d1d559 100644
--- a/drivers/gpu/drm/i915/display/intel_connector.h
+++ b/drivers/gpu/drm/i915/display/intel_connector.h
@@ -31,6 +31,7 @@ void intel_attach_broadcast_rgb_property(struct drm_connector *connector);
 void intel_attach_aspect_ratio_property(struct drm_connector *connector);
 void intel_attach_hdmi_colorspace_property(struct drm_connector *connector);
 void intel_attach_dp_colorspace_property(struct drm_connector *connector);
+void intel_attach_colorformat_property(struct drm_connector *connector);
 void intel_attach_scaling_mode_property(struct drm_connector *connector);
 void intel_connector_queue_modeset_retry_work(struct intel_connector *connector);
 void intel_connector_cancel_modeset_retry_work(struct intel_connector *connector);
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 4955bd8b11d7..31f2bb92bba6 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -1178,7 +1178,7 @@ dfp_can_convert(struct intel_dp *intel_dp,
 	return false;
 }
 
-static enum intel_output_format
+enum intel_output_format
 intel_dp_output_format(struct intel_connector *connector,
 		       enum intel_output_format sink_format)
 {
@@ -3337,17 +3337,24 @@ intel_dp_compute_output_format(struct intel_encoder *encoder,
 	struct intel_connector *connector = intel_dp->attached_connector;
 	const struct drm_display_info *info = &connector->base.display_info;
 	const struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
-	bool ycbcr_420_only;
+	enum drm_connector_color_format actual_format;
 	int ret;
 
-	ycbcr_420_only = drm_mode_is_420_only(info, adjusted_mode);
+	if ((conn_state->color_format == DRM_CONNECTOR_COLOR_FORMAT_YCBCR420 &&
+	     drm_mode_is_420(info, adjusted_mode)) ||
+	    (conn_state->color_format == DRM_CONNECTOR_COLOR_FORMAT_AUTO &&
+	     drm_mode_is_420_only(info, adjusted_mode)))
+		crtc_state->sink_format = INTEL_OUTPUT_FORMAT_YCBCR420;
+	else if (conn_state->color_format == DRM_CONNECTOR_COLOR_FORMAT_YCBCR444)
+		crtc_state->sink_format = INTEL_OUTPUT_FORMAT_YCBCR444;
+	else
+		crtc_state->sink_format = INTEL_OUTPUT_FORMAT_RGB;
 
-	if (ycbcr_420_only && !connector->base.ycbcr_420_allowed) {
+	if (crtc_state->sink_format == INTEL_OUTPUT_FORMAT_YCBCR420 &&
+	    !connector->base.ycbcr_420_allowed) {
 		drm_dbg_kms(display->drm,
-			    "YCbCr 4:2:0 mode but YCbCr 4:2:0 output not possible. Falling back to RGB.\n");
-		crtc_state->sink_format = INTEL_OUTPUT_FORMAT_RGB;
-	} else {
-		crtc_state->sink_format = intel_dp_sink_format(connector, adjusted_mode);
+			"YCbCr 4:2:0 mode requested but unsupported by connector.\n");
+		return -EINVAL;
 	}
 
 	crtc_state->output_format = intel_dp_output_format(connector, crtc_state->sink_format);
@@ -3355,9 +3362,20 @@ intel_dp_compute_output_format(struct intel_encoder *encoder,
 	ret = intel_dp_compute_link_config(encoder, crtc_state, conn_state,
 					   respect_downstream_limits);
 	if (ret) {
-		if (crtc_state->sink_format == INTEL_OUTPUT_FORMAT_YCBCR420 ||
-		    !connector->base.ycbcr_420_allowed ||
-		    !drm_mode_is_420_also(info, adjusted_mode))
+		/*
+		 * If no valid link config can be found due to bandwidth constraints,
+		 * degrade from RGB/YCbCr 4:4:4 to YCbCr 4:2:0 if permitted by
+		 * the source and sink.
+		 */
+		if (!connector->base.ycbcr_420_allowed)
+			return ret;
+		/* No point in trying YCbCr420 a second time. */
+		if (crtc_state->sink_format == INTEL_OUTPUT_FORMAT_YCBCR420)
+			return ret;
+		if (!drm_mode_is_420(info, adjusted_mode))
+			return ret;
+		/* If a non-AUTO color format is chosen, don't fall back. */
+		if (conn_state->color_format)
 			return ret;
 
 		crtc_state->sink_format = INTEL_OUTPUT_FORMAT_YCBCR420;
@@ -3365,9 +3383,36 @@ intel_dp_compute_output_format(struct intel_encoder *encoder,
 								   crtc_state->sink_format);
 		ret = intel_dp_compute_link_config(encoder, crtc_state, conn_state,
 						   respect_downstream_limits);
+		if (ret)
+			return ret;
 	}
 
-	return ret;
+	if (conn_state->color_format == DRM_CONNECTOR_COLOR_FORMAT_AUTO)
+		return 0;
+
+	switch (crtc_state->sink_format) {
+	case INTEL_OUTPUT_FORMAT_RGB:
+		actual_format = DRM_CONNECTOR_COLOR_FORMAT_RGB444;
+		break;
+	case INTEL_OUTPUT_FORMAT_YCBCR444:
+		actual_format = DRM_CONNECTOR_COLOR_FORMAT_YCBCR444;
+		break;
+	case INTEL_OUTPUT_FORMAT_YCBCR420:
+		actual_format = DRM_CONNECTOR_COLOR_FORMAT_YCBCR420;
+		break;
+	default:
+		drm_dbg_kms(display->drm, "Intel format %d has no connector equivalent\n",
+			    crtc_state->sink_format);
+		return -EINVAL;
+	}
+
+	if (actual_format != conn_state->color_format) {
+		drm_dbg_kms(display->drm, "Requested connector color format %d, got %d\n",
+			    conn_state->color_format, actual_format);
+		return -EINVAL;
+	}
+
+	return 0;
 }
 
 void
@@ -6956,6 +7001,8 @@ intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *_connec
 		intel_attach_dp_colorspace_property(&connector->base);
 	}
 
+	intel_attach_colorformat_property(&connector->base);
+
 	if (intel_dp_has_gamut_metadata_dip(&dp_to_dig_port(intel_dp)->base))
 		drm_connector_attach_hdr_output_metadata_property(&connector->base);
 
diff --git a/drivers/gpu/drm/i915/display/intel_dp.h b/drivers/gpu/drm/i915/display/intel_dp.h
index 2849b9ecdc71..c42badf752e2 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.h
+++ b/drivers/gpu/drm/i915/display/intel_dp.h
@@ -204,6 +204,10 @@ bool intel_dp_compute_config_limits(struct intel_dp *intel_dp,
 void intel_dp_get_dsc_sink_cap(u8 dpcd_rev,
 			       const struct drm_dp_desc *desc, bool is_branch,
 			       struct intel_connector *connector);
+enum intel_output_format
+intel_dp_output_format(struct intel_connector *connector,
+		       enum intel_output_format sink_format);
+
 bool intel_dp_has_gamut_metadata_dip(struct intel_encoder *encoder);
 
 bool intel_dp_link_params_valid(struct intel_dp *intel_dp, int link_rate,
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index 887b6de14e46..1b939c7adf9d 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -705,10 +705,13 @@ static int mst_stream_compute_config(struct intel_encoder *encoder,
 	struct intel_atomic_state *state = to_intel_atomic_state(conn_state->state);
 	struct intel_crtc *crtc = to_intel_crtc(pipe_config->uapi.crtc);
 	struct intel_dp *intel_dp = to_primary_dp(encoder);
+	enum drm_connector_color_format actual_format;
 	struct intel_connector *connector =
 		to_intel_connector(conn_state->connector);
 	const struct drm_display_mode *adjusted_mode =
 		&pipe_config->hw.adjusted_mode;
+	const struct drm_display_info *info =
+		&connector->base.display_info;
 	int num_joined_pipes;
 	int ret = -EINVAL;
 
@@ -719,10 +722,53 @@ static int mst_stream_compute_config(struct intel_encoder *encoder,
 	if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)
 		return -EINVAL;
 
-	pipe_config->sink_format = INTEL_OUTPUT_FORMAT_RGB;
-	pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
+	if ((conn_state->color_format == DRM_CONNECTOR_COLOR_FORMAT_YCBCR420 &&
+	     drm_mode_is_420(info, adjusted_mode)) ||
+	    (conn_state->color_format == DRM_CONNECTOR_COLOR_FORMAT_AUTO &&
+	     drm_mode_is_420_only(info, adjusted_mode))) {
+		pipe_config->sink_format = INTEL_OUTPUT_FORMAT_YCBCR420;
+	} else if (conn_state->color_format == DRM_CONNECTOR_COLOR_FORMAT_YCBCR444) {
+		pipe_config->sink_format = INTEL_OUTPUT_FORMAT_YCBCR444;
+	} else if (conn_state->color_format == DRM_CONNECTOR_COLOR_FORMAT_AUTO ||
+		   conn_state->color_format == DRM_CONNECTOR_COLOR_FORMAT_RGB444) {
+		pipe_config->sink_format = INTEL_OUTPUT_FORMAT_RGB;
+	} else {
+		drm_dbg_kms(display->drm, "Requested format %d unsupported.\n",
+			    conn_state->color_format);
+		return -EINVAL;
+	}
+
+	if (pipe_config->sink_format == INTEL_OUTPUT_FORMAT_YCBCR420 &&
+	    !connector->base.ycbcr_420_allowed) {
+		drm_dbg_kms(display->drm,
+			    "YCbCr 4:2:0 mode requested but unsupported by connector.\n");
+		return -EINVAL;
+	}
+
+	pipe_config->output_format = intel_dp_output_format(connector, pipe_config->sink_format);
 	pipe_config->has_pch_encoder = false;
 
+	/* Validate that the right format was picked if explicitly requested */
+	if (conn_state->color_format != DRM_CONNECTOR_COLOR_FORMAT_AUTO) {
+		switch (pipe_config->output_format) {
+		case INTEL_OUTPUT_FORMAT_RGB:
+			actual_format = DRM_CONNECTOR_COLOR_FORMAT_RGB444;
+			break;
+		case INTEL_OUTPUT_FORMAT_YCBCR444:
+			actual_format = DRM_CONNECTOR_COLOR_FORMAT_YCBCR444;
+			break;
+		case INTEL_OUTPUT_FORMAT_YCBCR420:
+			actual_format = DRM_CONNECTOR_COLOR_FORMAT_YCBCR420;
+			break;
+		}
+
+		if (actual_format != conn_state->color_format) {
+			drm_dbg_kms(display->drm, "Requested connector color format %d, got %d\n",
+				    conn_state->color_format, actual_format);
+			return -EINVAL;
+		}
+	}
+
 	for_each_joiner_candidate(connector, adjusted_mode, num_joined_pipes) {
 		if (num_joined_pipes > 1)
 			pipe_config->joiner_pipes = GENMASK(crtc->pipe + num_joined_pipes - 1,
@@ -1693,6 +1739,8 @@ static int mst_topology_add_connector_properties(struct intel_dp *intel_dp,
 	if (connector->base.max_bpc_property)
 		drm_connector_attach_max_bpc_property(&connector->base, 6, 12);
 
+	intel_attach_colorformat_property(&connector->base);
+
 	return drm_connector_set_path_property(&connector->base, pathprop);
 }
 
diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
index 05e898d10a2b..6b685d9a458e 100644
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -2270,33 +2270,73 @@ static int intel_hdmi_compute_output_format(struct intel_encoder *encoder,
 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
 	const struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
 	const struct drm_display_info *info = &connector->base.display_info;
-	bool ycbcr_420_only = drm_mode_is_420_only(info, adjusted_mode);
+	enum drm_connector_color_format req_fmt = conn_state->color_format;
+	enum drm_connector_color_format actual_fmt;
 	int ret;
 
-	crtc_state->sink_format =
-		intel_hdmi_sink_format(crtc_state, connector, ycbcr_420_only);
-
-	if (ycbcr_420_only && crtc_state->sink_format != INTEL_OUTPUT_FORMAT_YCBCR420) {
-		drm_dbg_kms(display->drm,
-			    "YCbCr 4:2:0 mode but YCbCr 4:2:0 output not possible. Falling back to RGB.\n");
-		crtc_state->sink_format = INTEL_OUTPUT_FORMAT_RGB;
-	}
+	if (!req_fmt)
+		crtc_state->sink_format =
+			intel_hdmi_sink_format(crtc_state, connector,
+					       drm_mode_is_420_only(info, adjusted_mode));
+	else if (req_fmt == DRM_CONNECTOR_COLOR_FORMAT_YCBCR444)
+		crtc_state->sink_format = INTEL_OUTPUT_FORMAT_YCBCR444;
+	else
+		crtc_state->sink_format =
+			intel_hdmi_sink_format(crtc_state, connector,
+					       req_fmt == DRM_CONNECTOR_COLOR_FORMAT_YCBCR420);
 
 	crtc_state->output_format = intel_hdmi_output_format(crtc_state);
 	ret = intel_hdmi_compute_clock(encoder, crtc_state, respect_downstream_limits);
 	if (ret) {
-		if (crtc_state->sink_format == INTEL_OUTPUT_FORMAT_YCBCR420 ||
-		    !crtc_state->has_hdmi_sink ||
-		    !connector->base.ycbcr_420_allowed ||
-		    !drm_mode_is_420_also(info, adjusted_mode))
+		/*
+		 * If no valid link config can be found due to bandwidth constraints,
+		 * degrade from RGB/YCbCr 4:4:4 to YCbCr 4:2:0 if permitted by
+		 * the source and sink.
+		 */
+		if (!connector->base.ycbcr_420_allowed)
+			return ret;
+		/* No point in trying YCbCr420 a second time. */
+		if (crtc_state->sink_format == INTEL_OUTPUT_FORMAT_YCBCR420)
+			return ret;
+		if (!drm_mode_is_420(info, adjusted_mode))
+			return ret;
+		/* If a non-AUTO color format is chosen, don't fall back. */
+		if (req_fmt)
 			return ret;
 
 		crtc_state->sink_format = INTEL_OUTPUT_FORMAT_YCBCR420;
 		crtc_state->output_format = intel_hdmi_output_format(crtc_state);
 		ret = intel_hdmi_compute_clock(encoder, crtc_state, respect_downstream_limits);
+		if (ret)
+			return ret;
 	}
 
-	return ret;
+	if (req_fmt == DRM_CONNECTOR_COLOR_FORMAT_AUTO)
+		return 0;
+
+	switch (crtc_state->sink_format) {
+	case INTEL_OUTPUT_FORMAT_RGB:
+		actual_fmt = DRM_CONNECTOR_COLOR_FORMAT_RGB444;
+		break;
+	case INTEL_OUTPUT_FORMAT_YCBCR444:
+		actual_fmt = DRM_CONNECTOR_COLOR_FORMAT_YCBCR444;
+		break;
+	case INTEL_OUTPUT_FORMAT_YCBCR420:
+		actual_fmt = DRM_CONNECTOR_COLOR_FORMAT_YCBCR420;
+		break;
+	default:
+		drm_dbg_kms(display->drm, "Intel format %d has no connector equivalent\n",
+			    crtc_state->sink_format);
+		return -EINVAL;
+	}
+
+	if (req_fmt != actual_fmt) {
+		drm_dbg_kms(display->drm, "Requested connector color format %d, got %d\n",
+			    req_fmt, actual_fmt);
+		return -EINVAL;
+	}
+
+	return 0;
 }
 
 static bool intel_hdmi_is_cloned(const struct intel_crtc_state *crtc_state)
@@ -2689,8 +2729,10 @@ intel_hdmi_add_properties(struct intel_hdmi *intel_hdmi, struct drm_connector *_
 	if (DISPLAY_VER(display) >= 10)
 		drm_connector_attach_hdr_output_metadata_property(&connector->base);
 
-	if (!HAS_GMCH(display))
+	if (!HAS_GMCH(display)) {
 		drm_connector_attach_max_bpc_property(&connector->base, 8, 12);
+		intel_attach_colorformat_property(&connector->base);
+	}
 }
 
 /*

-- 
2.53.0