drm: get cea video id code for a given display mode

[karo-tx-linux.git] / drivers / gpu / drm / drm_edid.c

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index fadcd44ff196f4951f3bf2bea9d74cdab06d63f3..856dcd91b3d4ba0ed040cdaa25f24d5cd45e5d66 100644 (file)
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1516,6 +1516,26 @@ u8 *drm_find_cea_extension(struct edid *edid)
 }
 EXPORT_SYMBOL(drm_find_cea_extension);
 
+/*
+ * Looks for a CEA mode matching given drm_display_mode.
+ * Returns its CEA Video ID code, or 0 if not found.
+ */
+u8 drm_match_cea_mode(struct drm_display_mode *to_match)
+{
+       struct drm_display_mode *cea_mode;
+       u8 mode;
+
+       for (mode = 0; mode < drm_num_cea_modes; mode++) {
+               cea_mode = (struct drm_display_mode *)&edid_cea_modes[mode];
+
+               if (drm_mode_equal(to_match, cea_mode))
+                       return mode + 1;
+       }
+       return 0;
+}
+EXPORT_SYMBOL(drm_match_cea_mode);
+
+
 static int
 do_cea_modes (struct drm_connector *connector, u8 *db, u8 len)
 {