[U-Boot] [PATCH] fdt: Fix handling of paths with options in them

[Hans de Goede]

After syncing the sunxi dts files with the upstream kernel dm/fdt sunxi
builds would no longer boot.

The problem is that stdout-path is now set like this in the upstream dts
files: stdout-path = "serial0:115200n8". The use of options in of-paths,
either after an alias name, or after a full path, e.g. stdout-path =
"/soc at 01c00000/serial at 01c28000:115200", is standard of usage, but something
which the u-boot dts code so far did not handle.

This commit fixes this, adding support for both path formats.

Signed-off-by: Hans de Goede <hdegoede at redhat.com>
---
 arch/arm/dts/sun7i-a20-pcduino3.dts |  2 +-
 lib/libfdt/fdt_ro.c                 | 25 ++++++++++++++++++++++---
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/arch/arm/dts/sun7i-a20-pcduino3.dts b/arch/arm/dts/sun7i-a20-pcduino3.dts
index cd05267..624abf2 100644
--- a/arch/arm/dts/sun7i-a20-pcduino3.dts
+++ b/arch/arm/dts/sun7i-a20-pcduino3.dts
@@ -64,7 +64,7 @@
 	};
 
 	chosen {
-		stdout-path = "serial0:115200n8";
+		stdout-path = "/soc at 01c00000/serial at 01c28000:115200";
 	};
 
 	leds {
diff --git a/lib/libfdt/fdt_ro.c b/lib/libfdt/fdt_ro.c
index 03733e5..44fc0aa 100644
--- a/lib/libfdt/fdt_ro.c
+++ b/lib/libfdt/fdt_ro.c
@@ -113,6 +113,25 @@ int fdt_subnode_offset(const void *fdt, int parentoffset,
 	return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name));
 }
 
+/*
+ * Find the next of path seperator, note we need to search for both '/' and ':'
+ * and then take the first one so that we do the rigth thing for e.g.
+ * "foo/bar:option" and "bar:option/otheroption", both of which happen, so
+ * first searching for either ':' or '/' does not work.
+ */
+static const char *fdt_path_next_seperator(const char *path)
+{
+	const char *sep1 = strchr(path, '/');
+	const char *sep2 = strchr(path, ':');
+
+	if (sep1 && sep2)
+		return (sep1 < sep2) ? sep1 : sep2;
+	else if (sep1)
+		return sep1;
+	else
+		return sep2;
+}
+
 int fdt_path_offset(const void *fdt, const char *path)
 {
 	const char *end = path + strlen(path);
@@ -123,7 +142,7 @@ int fdt_path_offset(const void *fdt, const char *path)
 
 	/* see if we have an alias */
 	if (*path != '/') {
-		const char *q = strchr(path, '/');
+		const char *q = fdt_path_next_seperator(path);
 
 		if (!q)
 			q = end;
@@ -141,9 +160,9 @@ int fdt_path_offset(const void *fdt, const char *path)
 
 		while (*p == '/')
 			p++;
-		if (! *p)
+		if (*p == '\0' || *p == ':')
 			return offset;
-		q = strchr(p, '/');
+		q = fdt_path_next_seperator(p);
 		if (! q)
 			q = end;
 
-- 
2.3.5