[PATCH v15 20/29] drm/connector: hdmi: Add RGB Quantization Range to the connector state

[Maxime Ripard]

HDMI controller drivers will need to figure out the RGB range they need
to configure based on a mode and property values. Let's expose that in
the HDMI connector state so drivers can just use that value.

Reviewed-by: Dave Stevenson <dave.stevenson at raspberrypi.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
Signed-off-by: Maxime Ripard <mripard at kernel.org>
---
 drivers/gpu/drm/display/drm_hdmi_state_helper.c | 29 +++++++++++++++++++++++++
 drivers/gpu/drm/drm_atomic.c                    |  1 +
 include/drm/drm_connector.h                     |  6 +++++
 3 files changed, 36 insertions(+)

diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
index 57c66beec5bc..f18020cfe4ea 100644
--- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
@@ -49,10 +49,37 @@ connector_state_get_mode(const struct drm_connector_state *conn_state)
 		return NULL;
 
 	return &crtc_state->mode;
 }
 
+static bool hdmi_is_limited_range(const struct drm_connector *connector,
+				  const struct drm_connector_state *conn_state)
+{
+	const struct drm_display_info *info = &connector->display_info;
+	const struct drm_display_mode *mode =
+		connector_state_get_mode(conn_state);
+
+	/*
+	 * The Broadcast RGB property only applies to RGB format, and
+	 * i915 just assumes limited range for YCbCr output, so let's
+	 * just do the same.
+	 */
+	if (conn_state->hdmi.output_format != HDMI_COLORSPACE_RGB)
+		return true;
+
+	if (conn_state->hdmi.broadcast_rgb == DRM_HDMI_BROADCAST_RGB_FULL)
+		return false;
+
+	if (conn_state->hdmi.broadcast_rgb == DRM_HDMI_BROADCAST_RGB_LIMITED)
+		return true;
+
+	if (!info->is_hdmi)
+		return false;
+
+	return drm_default_rgb_quant_range(mode) == HDMI_QUANTIZATION_RANGE_LIMITED;
+}
+
 static bool
 sink_supports_format_bpc(const struct drm_connector *connector,
 			 const struct drm_display_info *info,
 			 const struct drm_display_mode *mode,
 			 unsigned int format, unsigned int bpc)
@@ -327,10 +354,12 @@ int drm_atomic_helper_connector_hdmi_check(struct drm_connector *connector,
 		drm_atomic_get_new_connector_state(state, connector);
 	const struct drm_display_mode *mode =
 		connector_state_get_mode(new_conn_state);
 	int ret;
 
+	new_conn_state->hdmi.is_limited_range = hdmi_is_limited_range(connector, new_conn_state);
+
 	ret = hdmi_compute_config(connector, new_conn_state, mode);
 	if (ret)
 		return ret;
 
 	if (old_conn_state->hdmi.broadcast_rgb != new_conn_state->hdmi.broadcast_rgb ||
diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 3e57d98d8418..07b4b394e3bf 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1145,10 +1145,11 @@ static void drm_atomic_connector_print_state(struct drm_printer *p,
 
 	if (connector->connector_type == DRM_MODE_CONNECTOR_HDMIA ||
 	    connector->connector_type == DRM_MODE_CONNECTOR_HDMIB) {
 		drm_printf(p, "\tbroadcast_rgb=%s\n",
 			   drm_hdmi_connector_get_broadcast_rgb_name(state->hdmi.broadcast_rgb));
+		drm_printf(p, "\tis_limited_range=%c\n", state->hdmi.is_limited_range ? 'y' : 'n');
 		drm_printf(p, "\toutput_bpc=%u\n", state->hdmi.output_bpc);
 		drm_printf(p, "\toutput_format=%s\n",
 			   drm_hdmi_connector_get_output_format_name(state->hdmi.output_format));
 		drm_printf(p, "\ttmds_char_rate=%llu\n", state->hdmi.tmds_char_rate);
 	}
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index a40eaf3a8ce4..1fca26d51218 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -1068,10 +1068,16 @@ struct drm_connector_state {
 		 * @broadcast_rgb: Connector property to pass the
 		 * Broadcast RGB selection value.
 		 */
 		enum drm_hdmi_broadcast_rgb broadcast_rgb;
 
+		/**
+		 * @is_full_range: Is the output supposed to use a full
+		 * RGB Quantization Range or not?
+		 */
+		bool is_limited_range;
+
 		/**
 		 * @output_bpc: Bits per color channel to output.
 		 */
 		unsigned int output_bpc;
 

-- 
2.45.0