drm/edid: convert add_cea_modes() to use cea db iter

Iterate through all CTA EDID extension blocks and DisplayID CTA data
blocks to add CEA modes.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/dfa2d79db61d5eea543bef7aca7d80da3e71f99d.1651569697.git.jani.nikula@intel.com

drivers/gpu/drm/drm_edid.c

@@ -4689,46 +4689,41 @@ static void drm_parse_y420cmdb_bitmap(struct drm_connector *connector,
 static int
 add_cea_modes(struct drm_connector *connector, const struct edid *edid)
 {
-	const u8 *cea = drm_find_cea_extension(edid);
-	const u8 *db, *hdmi = NULL, *video = NULL;
-	u8 dbl, hdmi_len, video_len = 0;
+	const struct cea_db *db;
+	struct cea_db_iter iter;
 	int modes = 0;
 
-	if (cea && cea_revision(cea) >= 3) {
-		int i, start, end;
-
-		if (cea_db_offsets(cea, &start, &end))
-			return 0;
-
-		for_each_cea_db(cea, i, start, end) {
-			db = &cea[i];
-			dbl = cea_db_payload_len(db);
-
-			if (cea_db_tag(db) == CTA_DB_VIDEO) {
-				video = db + 1;
-				video_len = dbl;
-				modes += do_cea_modes(connector, video, dbl);
-			} else if (cea_db_is_hdmi_vsdb(db)) {
-				hdmi = db;
-				hdmi_len = dbl;
-			} else if (cea_db_is_y420vdb(db)) {
-				const u8 *vdb420 = &db[2];
-
-				/* Add 4:2:0(only) modes present in EDID */
-				modes += do_y420vdb_modes(connector,
-							  vdb420,
-							  dbl - 1);
-			}
+	cea_db_iter_edid_begin(edid, &iter);
+	cea_db_iter_for_each(db, &iter) {
+		const u8 *hdmi = NULL, *video = NULL;
+		u8 hdmi_len = 0, video_len = 0;
+
+		if (cea_db_tag(db) == CTA_DB_VIDEO) {
+			video = cea_db_data(db);
+			video_len = cea_db_payload_len(db);
+			modes += do_cea_modes(connector, video, video_len);
+		} else if (cea_db_is_hdmi_vsdb(db)) {
+			/* FIXME: Switch to use cea_db_data() */
+			hdmi = (const u8 *)db;
+			hdmi_len = cea_db_payload_len(db);
+		} else if (cea_db_is_y420vdb(db)) {
+			const u8 *vdb420 = cea_db_data(db) + 1;
+
+			/* Add 4:2:0(only) modes present in EDID */
+			modes += do_y420vdb_modes(connector, vdb420,
+						  cea_db_payload_len(db) - 1);
 		}
-	}
 
-	/*
-	 * We parse the HDMI VSDB after having added the cea modes as we will
-	 * be patching their flags when the sink supports stereo 3D.
-	 */
-	if (hdmi)
-		modes += do_hdmi_vsdb_modes(connector, hdmi, hdmi_len, video,
-					    video_len);
+		/*
+		 * We parse the HDMI VSDB after having added the cea modes as we
+		 * will be patching their flags when the sink supports stereo
+		 * 3D.
+		 */
+		if (hdmi)
+			modes += do_hdmi_vsdb_modes(connector, hdmi, hdmi_len,
+						    video, video_len);
+	}
+	cea_db_iter_end(&iter);
 
 	return modes;
 }