libfdt: Add function to explicitly expand aliases
Kumar has already added alias expansion to fdt_path_offset().
However, in some circumstances it may be convenient for the user of
libfdt to explicitly get the string expansion of an alias. This patch
adds a function to do this, fdt_get_alias(), and uses it to implement
fdt_path_offset().
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
diff --git a/libfdt/fdt_ro.c b/libfdt/fdt_ro.c
index f559eed..b705f91 100644
--- a/libfdt/fdt_ro.c
+++ b/libfdt/fdt_ro.c
@@ -145,17 +145,12 @@
/* see if we have an alias */
if (*path != '/') {
- const char *q;
- int aliasoffset = fdt_path_offset(fdt, "/aliases");
+ const char *q = strchr(path, '/');
- if (aliasoffset < 0)
- return -FDT_ERR_BADPATH;
-
- q = strchr(path, '/');
if (!q)
q = end;
- p = fdt_getprop_namelen(fdt, aliasoffset, path, q - p, NULL);
+ p = fdt_get_alias_namelen(fdt, p, q - p);
if (!p)
return -FDT_ERR_BADPATH;
offset = fdt_path_offset(fdt, p);
@@ -306,6 +301,23 @@
return fdt32_to_cpu(*php);
}
+const char *fdt_get_alias_namelen(const void *fdt,
+ const char *name, int namelen)
+{
+ int aliasoffset;
+
+ aliasoffset = fdt_path_offset(fdt, "/aliases");
+ if (aliasoffset < 0)
+ return NULL;
+
+ return fdt_getprop_namelen(fdt, aliasoffset, name, namelen, NULL);
+}
+
+const char *fdt_get_alias(const void *fdt, const char *name)
+{
+ return fdt_get_alias_namelen(fdt, name, strlen(name));
+}
+
int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen)
{
int pdepth = 0, p = 0;