dm: serial: Deal with stdout-path with an alias

Sometimes stdout-path contains a UART alias along with speed, etc. For
example:

	stdout-path = "serial0:115200n8";

Add support for decoding this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

drivers/serial/serial-uclass.c

@@ -29,14 +29,34 @@ static const unsigned long baudrate_table[] = CONFIG_SYS_BAUDRATE_TABLE;
 
 static void serial_find_console_or_panic(void)
 {
+	const void *blob = gd->fdt_blob;
 	struct udevice *dev;
 	int node;
 
-	if (CONFIG_IS_ENABLED(OF_CONTROL) && gd->fdt_blob) {
+	if (CONFIG_IS_ENABLED(OF_CONTROL) && blob) {
 		/* Check for a chosen console */
-		node = fdtdec_get_chosen_node(gd->fdt_blob, "stdout-path");
+		node = fdtdec_get_chosen_node(blob, "stdout-path");
+		if (node < 0) {
+			const char *str, *p, *name;
+
+			/*
+			 * Deal with things like
+			 *	stdout-path = "serial0:115200n8";
+			 *
+			 * We need to look up the alias and then follow it to
+			 * the correct node.
+			 */
+			str = fdtdec_get_chosen_prop(blob, "stdout-path");
+			if (str) {
+				p = strchr(str, ':');
+				name = fdt_get_alias_namelen(blob, str,
+						p ? p - str : strlen(str));
+				if (name)
+					node = fdt_path_offset(blob, name);
+			}
+		}
 		if (node < 0)
-			node = fdt_path_offset(gd->fdt_blob, "console");
+			node = fdt_path_offset(blob, "console");
 		if (!uclass_get_device_by_of_offset(UCLASS_SERIAL, node,
 						    &dev)) {
 			gd->cur_serial_dev = dev;
@@ -48,14 +68,14 @@ static void serial_find_console_or_panic(void)
 		* bind it anyway.
 		*/
 		if (node > 0 &&
-		    !lists_bind_fdt(gd->dm_root, gd->fdt_blob, node, &dev)) {
+		    !lists_bind_fdt(gd->dm_root, blob, node, &dev)) {
 			if (!device_probe(dev)) {
 				gd->cur_serial_dev = dev;
 				return;
 			}
 		}
 	}
-	if (!SPL_BUILD || !CONFIG_IS_ENABLED(OF_CONTROL) || !gd->fdt_blob) {
+	if (!SPL_BUILD || !CONFIG_IS_ENABLED(OF_CONTROL) || !blob) {
 		/*
 		* Try to use CONFIG_CONS_INDEX if available (it is numbered
 		* from 1!).