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

Iterate through all CTA data blocks across all CTA extensions and
DisplayID data blocks. This may gather more data than before, and if
there's duplicated data, some is overwritten by whichever comes last.

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/8bdc67aa731857111eddd08a9c192d41d40b5f5a.1651569697.git.jani.nikula@intel.com

drivers/gpu/drm/drm_edid.c

@@ -4911,12 +4911,12 @@ static void clear_eld(struct drm_connector *connector)
 static void drm_edid_to_eld(struct drm_connector *connector,
 			    const struct edid *edid)
 {
+	const struct cea_db *db;
+	struct cea_db_iter iter;
 	uint8_t *eld = connector->eld;
 	const u8 *cea;
-	const u8 *db;
 	int total_sad_count = 0;
 	int mnl;
-	int dbl;
 
 	clear_eld(connector);
 
@@ -4942,43 +4942,37 @@ static void drm_edid_to_eld(struct drm_connector *connector,
 	eld[DRM_ELD_PRODUCT_CODE0] = edid->prod_code[0];
 	eld[DRM_ELD_PRODUCT_CODE1] = edid->prod_code[1];
 
-	if (cea_revision(cea) >= 3) {
-		int i, start, end;
+	cea_db_iter_edid_begin(edid, &iter);
+	cea_db_iter_for_each(db, &iter) {
+		const u8 *data = cea_db_data(db);
+		int len = cea_db_payload_len(db);
 		int sad_count;
 
-		if (cea_db_offsets(cea, &start, &end)) {
-			start = 0;
-			end = 0;
-		}
-
-		for_each_cea_db(cea, i, start, end) {
-			db = &cea[i];
-			dbl = cea_db_payload_len(db);
-
-			switch (cea_db_tag(db)) {
-			case CTA_DB_AUDIO:
-				/* Audio Data Block, contains SADs */
-				sad_count = min(dbl / 3, 15 - total_sad_count);
-				if (sad_count >= 1)
-					memcpy(&eld[DRM_ELD_CEA_SAD(mnl, total_sad_count)],
-					       &db[1], sad_count * 3);
-				total_sad_count += sad_count;
-				break;
-			case CTA_DB_SPEAKER:
-				/* Speaker Allocation Data Block */
-				if (dbl >= 1)
-					eld[DRM_ELD_SPEAKER] = db[1];
-				break;
-			case CTA_DB_VENDOR:
-				/* HDMI Vendor-Specific Data Block */
-				if (cea_db_is_hdmi_vsdb(db))
-					drm_parse_hdmi_vsdb_audio(connector, db);
-				break;
-			default:
-				break;
-			}
+		switch (cea_db_tag(db)) {
+		case CTA_DB_AUDIO:
+			/* Audio Data Block, contains SADs */
+			sad_count = min(len / 3, 15 - total_sad_count);
+			if (sad_count >= 1)
+				memcpy(&eld[DRM_ELD_CEA_SAD(mnl, total_sad_count)],
+				       data, sad_count * 3);
+			total_sad_count += sad_count;
+			break;
+		case CTA_DB_SPEAKER:
+			/* Speaker Allocation Data Block */
+			if (len >= 1)
+				eld[DRM_ELD_SPEAKER] = data[0];
+			break;
+		case CTA_DB_VENDOR:
+			/* HDMI Vendor-Specific Data Block */
+			if (cea_db_is_hdmi_vsdb(db))
+				drm_parse_hdmi_vsdb_audio(connector, (const u8 *)db);
+			break;
+		default:
+			break;
 		}
 	}
+	cea_db_iter_end(&iter);
+
 	eld[DRM_ELD_SAD_COUNT_CONN_TYPE] |= total_sad_count << DRM_ELD_SAD_COUNT_SHIFT;
 
 	if (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort ||