fdt: Add a function to get the index of a string
Given a device tree node and a property name, the new fdt_find_string()
function will look up a given string in the string list contained in the
property's value and return its index.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/include/libfdt.h b/include/libfdt.h
index cf97bf0..d0dea66 100644
--- a/include/libfdt.h
+++ b/include/libfdt.h
@@ -866,6 +866,17 @@
*/
int fdt_count_strings(const void *fdt, int node, const char *property);
+/**
+ * fdt_find_string - find a string in a string list and return its index
+ * @fdt: pointer to the device tree blob
+ * @node: offset of the node
+ * @property: name of the property containing the string list
+ * @string: string to look up in the string list
+ * @return: the index of the string or negative on error
+ */
+int fdt_find_string(const void *fdt, int node, const char *property,
+ const char *string);
+
/**********************************************************************/
/* Read-only functions (addressing related) */
/**********************************************************************/
diff --git a/lib/libfdt/fdt_ro.c b/lib/libfdt/fdt_ro.c
index cb06a9b..fec4a0a 100644
--- a/lib/libfdt/fdt_ro.c
+++ b/lib/libfdt/fdt_ro.c
@@ -511,6 +511,32 @@
return count;
}
+int fdt_find_string(const void *fdt, int node, const char *property,
+ const char *string)
+{
+ const char *list, *end;
+ int len, index = 0;
+
+ list = fdt_getprop(fdt, node, property, &len);
+ if (!list)
+ return len;
+
+ end = list + len;
+ len = strlen(string);
+
+ while (list < end) {
+ int l = strlen(list);
+
+ if (l == len && memcmp(list, string, len) == 0)
+ return index;
+
+ list += l + 1;
+ index++;
+ }
+
+ return -FDT_ERR_NOTFOUND;
+}
+
int fdt_node_check_compatible(const void *fdt, int nodeoffset,
const char *compatible)
{