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>

1 files changed, 11 insertions, 0 deletions

diff --git a/include/libfdt.h b/include/libfdt.h
index cf97bf0b3b..d0dea668ee 100644
--- a/include/libfdt.h
+++ b/include/libfdt.h
@@ -866,6 +866,17 @@ int fdt_stringlist_contains(const char *strlist, int listlen, const char *str);
  */
 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)                           */
 /**********************************************************************/