1 files changed, 58 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index 35630b80cd48..c1aec532281c 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -1605,3 +1605,61 @@ int drm_mode_convert_umode(struct drm_display_mode *out,
 out:
 	return ret;
 }
+
+/**
+ * drm_mode_is_420_only - if a given videomode can be only supported in YCBCR420
+ * output format
+ *
+ * @connector: drm connector under action.
+ * @mode: video mode to be tested.
+ *
+ * Returns:
+ * true if the mode can be supported in YCBCR420 format
+ * false if not.
+ */
+bool drm_mode_is_420_only(const struct drm_display_info *display,
+			  const struct drm_display_mode *mode)
+{
+	u8 vic = drm_match_cea_mode(mode);
+
+	return test_bit(vic, display->hdmi.y420_vdb_modes);
+}
+EXPORT_SYMBOL(drm_mode_is_420_only);
+
+/**
+ * drm_mode_is_420_also - if a given videomode can be supported in YCBCR420
+ * output format also (along with RGB/YCBCR444/422)
+ *
+ * @display: display under action.
+ * @mode: video mode to be tested.
+ *
+ * Returns:
+ * true if the mode can be support YCBCR420 format
+ * false if not.
+ */
+bool drm_mode_is_420_also(const struct drm_display_info *display,
+			  const struct drm_display_mode *mode)
+{
+	u8 vic = drm_match_cea_mode(mode);
+
+	return test_bit(vic, display->hdmi.y420_cmdb_modes);
+}
+EXPORT_SYMBOL(drm_mode_is_420_also);
+/**
+ * drm_mode_is_420 - if a given videomode can be supported in YCBCR420
+ * output format
+ *
+ * @display: display under action.
+ * @mode: video mode to be tested.
+ *
+ * Returns:
+ * true if the mode can be supported in YCBCR420 format
+ * false if not.
+ */
+bool drm_mode_is_420(const struct drm_display_info *display,
+		     const struct drm_display_mode *mode)
+{
+	return drm_mode_is_420_only(display, mode) ||
+		drm_mode_is_420_also(display, mode);
+}
+EXPORT_SYMBOL(drm_mode_is_420);