summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--include/libfdt.h26
-rw-r--r--libfdt/fdt_ro.c26
2 files changed, 45 insertions, 7 deletions
diff --git a/include/libfdt.h b/include/libfdt.h
index 5492a53..7cad68c 100644
--- a/include/libfdt.h
+++ b/include/libfdt.h
@@ -459,6 +459,32 @@ static inline void *fdt_getprop_w(void *fdt, int nodeoffset,
uint32_t fdt_get_phandle(const void *fdt, int nodeoffset);
/**
+ * fdt_get_namelen - get alias based on substring
+ * @fdt: pointer to the device tree blob
+ * @name: name of the alias th look up
+ * @namelen: number of characters of name to consider
+ *
+ * Identical to fdt_get_alias(), but only examine the first namelen
+ * characters of name for matching the alias name.
+ */
+const char *fdt_get_alias_namelen(const void *fdt,
+ const char *name, int namelen);
+
+/**
+ * fdt_get_alias - retreive the path referenced by a given alias
+ * @fdt: pointer to the device tree blob
+ * @name: name of the alias th look up
+ *
+ * fdt_get_alias() retrieves the value of a given alias. That is, the
+ * value of the property named 'name' in the node /aliases.
+ *
+ * returns:
+ * a pointer to the expansion of the alias named 'name', of it exists
+ * NULL, if the given alias or the /aliases node does not exist
+ */
+const char *fdt_get_alias(const void *fdt, const char *name);
+
+/**
* fdt_get_path - determine the full path of a node
* @fdt: pointer to the device tree blob
* @nodeoffset: offset of the node whose path to find
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 @@ int fdt_path_offset(const void *fdt, const char *path)
/* see if we have an alias */
if (*path != '/') {
- const char *q;
- int aliasoffset = fdt_path_offset(fdt, "/aliases");
-
- if (aliasoffset < 0)
- return -FDT_ERR_BADPATH;
+ const char *q = strchr(path, '/');
- 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 @@ uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
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;