[PATCH v9 04/19] drm/display: hdmi-state-helper: Act on color format DRM property

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

With the introduction of the "color format" DRM property, which allows
userspace to request a specific color format, the HDMI state helper
should implement this.

Implement it by translating the requested drm_connector_color_format to
a drm_output_color_format enum value as per the logic HDMI should use
for this: Auto is translated to RGB, and a fallback to YUV420 is only
performed if the original color format was auto.

Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
---
 drivers/gpu/drm/display/drm_hdmi_state_helper.c | 28 +++++++++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
index 9f3b696aceeb..31c6d55fa995 100644
--- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
@@ -669,10 +669,34 @@ hdmi_compute_config(const struct drm_connector *connector,
 	unsigned int max_bpc = clamp_t(unsigned int,
 				       conn_state->max_bpc,
 				       8, connector->max_bpc);
+	enum drm_output_color_format fmt;
 	int ret;
 
-	ret = hdmi_compute_format_bpc(connector, conn_state, mode, max_bpc,
-				      DRM_OUTPUT_COLOR_FORMAT_RGB444);
+	switch (conn_state->color_format) {
+	case DRM_CONNECTOR_COLOR_FORMAT_AUTO:
+	case DRM_CONNECTOR_COLOR_FORMAT_RGB444:
+		fmt = DRM_OUTPUT_COLOR_FORMAT_RGB444;
+		break;
+	case DRM_CONNECTOR_COLOR_FORMAT_YCBCR444:
+		fmt = DRM_OUTPUT_COLOR_FORMAT_YCBCR444;
+		break;
+	case DRM_CONNECTOR_COLOR_FORMAT_YCBCR422:
+		fmt = DRM_OUTPUT_COLOR_FORMAT_YCBCR422;
+		break;
+	case DRM_CONNECTOR_COLOR_FORMAT_YCBCR420:
+		fmt = DRM_OUTPUT_COLOR_FORMAT_YCBCR420;
+		break;
+	default:
+		drm_dbg_kms(connector->dev, "HDMI does not support color format '%d'.\n",
+			    conn_state->color_format);
+		return -EINVAL;
+	}
+
+	ret = hdmi_compute_format_bpc(connector, conn_state, mode, max_bpc, fmt);
+
+	if (conn_state->color_format != DRM_CONNECTOR_COLOR_FORMAT_AUTO)
+		return ret;
+
 	if (ret) {
 		if (connector->ycbcr_420_allowed) {
 			ret = hdmi_compute_format_bpc(connector, conn_state,

-- 
2.53.0