[PATCH v6 03/21] drm: Add enum conversions between DRM_COLOR_FORMAT and HDMI_COLORSPACE

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

While the two enums have similar values, they're not identical, and
HDMI's enum is defined as per the HDMI standard.

Add a simple conversion function from DRM to HDMI. Unexpected inputs
aren't handled in any clever way, DRM_COLOR_FORMAT_AUTO and any other
value that doesn't cleanly map to HDMI just gets returned as
HDMI_COLORSPACE_RGB.

Add a second conversion function that gets a DRM_COLOR_FORMAT from an
HDMI_COLORSPACE as well. In this case, reserved HDMI values that can't
be converted will result in an -EINVAL return value.

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>
---
 include/drm/drm_connector.h | 54 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index b5604dca728a..ffeb42f3b4a3 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -2612,6 +2612,60 @@ int drm_connector_attach_color_format_property(struct drm_connector *connector);
 
 const char *drm_get_color_format_name(enum drm_color_format color_fmt);
 
+/**
+ * drm_color_format_to_hdmi_colorspace - convert DRM color format to HDMI
+ * @fmt: the &enum drm_color_format to convert
+ *
+ * Convert a given &enum drm_color_format to an equivalent
+ * &enum hdmi_colorspace. For non-representable values and
+ * %DRM_COLOR_FORMAT_AUTO, the value %HDMI_COLORSPACE_RGB is returned.
+ *
+ * Returns: the corresponding &enum hdmi_colorspace value
+ */
+static inline enum hdmi_colorspace __pure
+drm_color_format_to_hdmi_colorspace(enum drm_color_format fmt)
+{
+	switch (fmt) {
+	default:
+	case DRM_COLOR_FORMAT_AUTO:
+	case DRM_COLOR_FORMAT_RGB444:
+		return HDMI_COLORSPACE_RGB;
+	case DRM_COLOR_FORMAT_YCBCR444:
+		return HDMI_COLORSPACE_YUV444;
+	case DRM_COLOR_FORMAT_YCBCR422:
+		return HDMI_COLORSPACE_YUV422;
+	case DRM_COLOR_FORMAT_YCBCR420:
+		return HDMI_COLORSPACE_YUV420;
+	}
+}
+
+/**
+ * drm_color_format_from_hdmi_colorspace - convert HDMI color format to DRM
+ * @fmt: the &enum hdmi_colorspace to convert
+ *
+ * Convert a given &enum hdmi_colorspace to an equivalent
+ * &enum drm_color_format. For non-representable values,
+ * %-EINVAL is returned.
+ *
+ * Returns: the corresponding &enum drm_color_format value, or %-EINVAL
+ */
+static inline enum drm_color_format __pure
+drm_color_format_from_hdmi_colorspace(enum hdmi_colorspace fmt)
+{
+	switch (fmt) {
+	default:
+		return -EINVAL;
+	case HDMI_COLORSPACE_RGB:
+		return DRM_COLOR_FORMAT_RGB444;
+	case HDMI_COLORSPACE_YUV444:
+		return DRM_COLOR_FORMAT_YCBCR444;
+	case HDMI_COLORSPACE_YUV422:
+		return DRM_COLOR_FORMAT_YCBCR422;
+	case HDMI_COLORSPACE_YUV420:
+		return DRM_COLOR_FORMAT_YCBCR420;
+	}
+}
+
 /**
  * drm_for_each_connector_iter - connector_list iterator macro
  * @connector: &struct drm_connector pointer used as cursor

-- 
2.52.0