From: Thierry Reding treding@nvidia.com
Given a device tree node and a property name, the fdt_get_string_index() 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 --- include/libfdt.h | 11 +++++++++++ lib/libfdt/fdt_ro.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+)
diff --git a/include/libfdt.h b/include/libfdt.h index e7f991b388cf..4d7fb2681669 100644 --- a/include/libfdt.h +++ b/include/libfdt.h @@ -857,6 +857,17 @@ int fdt_node_offset_by_compatible(const void *fdt, int startoffset, */ int fdt_stringlist_contains(const char *strlist, int listlen, const char *str);
+/** + * fdt_get_string_index - get the index of a string in a string list + * @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_get_string_index(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 17cd11333c1e..f211c64ca7ca 100644 --- a/lib/libfdt/fdt_ro.c +++ b/lib/libfdt/fdt_ro.c @@ -14,6 +14,8 @@
#include "libfdt_internal.h"
+#define max(x, y) (((x) < (y)) ? (y) : (x)) + static int _fdt_nodename_eq(const void *fdt, int offset, const char *s, int len) { @@ -491,6 +493,32 @@ int fdt_stringlist_contains(const char *strlist, int listlen, const char *str) return 0; }
+int fdt_get_string_index(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; + + while (list < end) { + int n = strlen(string); + int m = strlen(list); + + if (n == m && memcmp(list, string, n) == 0) + return index; + + list += max(n, m) + 1; + index++; + } + + return -FDT_ERR_NOTFOUND; +} + int fdt_node_check_compatible(const void *fdt, int nodeoffset, const char *compatible) {