[RFC 09/19] drm/edid: convert drm_edid_to_sad() to use cea db iter

[Jani Nikula <jani.nikula@xxxxxxxxx>]

Use the cea db iterator for short audio descriptors. We'll still stop at
the first audio data block, but not at the first CEA extension if that
doesn't have the info.

Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
---
 drivers/gpu/drm/drm_edid.c | 34 +++++++++-------------------------
 1 file changed, 9 insertions(+), 25 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 992b3578a73f..e341790521d6 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -4854,40 +4854,21 @@ static void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
  */
 int drm_edid_to_sad(struct edid *edid, struct cea_sad **sads)
 {
+	const struct cea_db *db;
+	struct cea_db_iter iter;
 	int count = 0;
-	int i, start, end, dbl;
-	const u8 *cea;
-
-	cea = drm_find_cea_extension(edid);
-	if (!cea) {
-		DRM_DEBUG_KMS("SAD: no CEA Extension found\n");
-		return 0;
-	}
-
-	if (cea_revision(cea) < 3) {
-		DRM_DEBUG_KMS("SAD: wrong CEA revision\n");
-		return 0;
-	}
-
-	if (cea_db_offsets(cea, &start, &end)) {
-		DRM_DEBUG_KMS("SAD: invalid data block offsets\n");
-		return -EPROTO;
-	}
-
-	for_each_cea_db(cea, i, start, end) {
-		const u8 *db = &cea[i];
 
+	cea_db_iter_edid_begin(edid, &iter);
+	cea_db_iter_for_each(db, &iter) {
 		if (cea_db_tag(db) == CEA_DB_AUDIO) {
 			int j;
 
-			dbl = cea_db_payload_len(db);
-
-			count = dbl / 3; /* SAD is 3B */
+			count = cea_db_payload_len(db) / 3; /* SAD is 3B */
 			*sads = kcalloc(count, sizeof(**sads), GFP_KERNEL);
 			if (!*sads)
 				return -ENOMEM;
 			for (j = 0; j < count; j++) {
-				const u8 *sad = &db[1 + j * 3];
+				const u8 *sad = &db->data[j * 3];
 
 				(*sads)[j].format = (sad[0] & 0x78) >> 3;
 				(*sads)[j].channels = sad[0] & 0x7;
@@ -4897,6 +4878,9 @@ int drm_edid_to_sad(struct edid *edid, struct cea_sad **sads)
 			break;
 		}
 	}
+	cea_db_iter_end(&iter);
+
+	DRM_DEBUG_KMS("Found %d Short Audio Descriptors\n", count);
 
 	return count;
 }
-- 
2.30.2