common: edid: extract code for detailed timing search

Code which searches for valid detailed timing entry will be used in more
places. Extract it.

No functional change is made. However, descriptors are casted to
edid_detailed_timing instead of edid_monitor_descriptor. Descriptor can
be of either type, but since we're interested only in DTD, it is more
fitting to cast to edid_detailed_timing.
Reviewed-by: NAndre Przywara <andre.przywara@arm.com>
Signed-off-by: NJernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: NAndre Przywara <andre.przywara@arm.com>

common/edid.c

@@ -169,6 +169,29 @@ static bool cea_is_hdmi_vsdb_present(struct edid_cea861_info *info)
 	return false;
 }
 
+static bool edid_find_valid_timing(void *buf, int count,
+				   struct display_timing *timing,
+				   bool (*mode_valid)(void *priv,
+					const struct display_timing *timing),
+				   void *mode_valid_priv)
+{
+	struct edid_detailed_timing *t = buf;
+	bool found = false;
+	int i;
+
+	for (i = 0; i < count && !found; i++, t++)
+		if (EDID_DETAILED_TIMING_PIXEL_CLOCK(*t) != 0) {
+			decode_timing((u8 *)t, timing);
+			if (mode_valid)
+				found = mode_valid(mode_valid_priv,
+						   timing);
+			else
+				found = true;
+		}
+
+	return found;
+}
+
 int edid_get_timing_validate(u8 *buf, int buf_size,
 			     struct display_timing *timing,
 			     int *panel_bits_per_colourp,
@@ -177,8 +200,7 @@ int edid_get_timing_validate(u8 *buf, int buf_size,
 			     void *mode_valid_priv)
 {
 	struct edid1_info *edid = (struct edid1_info *)buf;
-	bool timing_done;
-	int i;
+	bool found;
 
 	if (buf_size < sizeof(*edid) || edid_check_info(edid)) {
 		debug("%s: Invalid buffer\n", __func__);
@@ -195,25 +217,10 @@ int edid_get_timing_validate(u8 *buf, int buf_size,
 		return -ENOENT;
 	}
 
-	/* Look for detailed timing */
-	timing_done = false;
-	for (i = 0; i < 4; i++) {
-		struct edid_monitor_descriptor *desc;
-
-		desc = &edid->monitor_details.descriptor[i];
-		if (desc->zero_flag_1 != 0) {
-			decode_timing((u8 *)desc, timing);
-			if (mode_valid)
-				timing_done = mode_valid(mode_valid_priv,
-							 timing);
-			else
-				timing_done = true;
-
-			if (timing_done)
-				break;
-		}
-	}
-	if (!timing_done)
+	/* Look for detailed timing in base EDID */
+	found = edid_find_valid_timing(edid->monitor_details.descriptor, 4,
+				       timing, mode_valid, mode_valid_priv);
+	if (!found)
 		return -EINVAL;
 
 	if (edid->version != 1 || edid->revision < 4) {