From: Thierry Reding treding@nvidia.com
Given a device tree node, a property name and an index, the new function fdt_get_string_index() will return in an output argument a pointer to the index'th string in the property's value.
The fdt_get_string() is a shortcut for the above with the index being 0.
Signed-off-by: Thierry Reding treding@nvidia.com --- include/libfdt.h | 27 +++++++++++++++++++++++++++ lib/libfdt/fdt_ro.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 57 insertions(+)
diff --git a/include/libfdt.h b/include/libfdt.h index d0dea668eea2..2dfc6d9e5ce7 100644 --- a/include/libfdt.h +++ b/include/libfdt.h @@ -877,6 +877,33 @@ int fdt_count_strings(const void *fdt, int node, const char *property); int fdt_find_string(const void *fdt, int node, const char *property, const char *string);
+/** + * fdt_get_string_index() - obtain the string at a given index 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 + * @index: index of the string to return + * @output: return location for the string + * @return: 0 if the string was found or a negative error code otherwise + */ +int fdt_get_string_index(const void *fdt, int node, const char *property, + int index, const char **output); + +/** + * fdt_get_string() - obtain the string at a given index 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 + * @output: return location for the string + * @return: 0 if the string was found or a negative error code otherwise + * + * This is a shortcut for: + * + * fdt_get_string_index(fdt, node, property, 0, output). + */ +int fdt_get_string(const void *fdt, int node, const char *property, + const char **output); + /**********************************************************************/ /* Read-only functions (addressing related) */ /**********************************************************************/ diff --git a/lib/libfdt/fdt_ro.c b/lib/libfdt/fdt_ro.c index fec4a0a141fd..03733e574f71 100644 --- a/lib/libfdt/fdt_ro.c +++ b/lib/libfdt/fdt_ro.c @@ -537,6 +537,36 @@ int fdt_find_string(const void *fdt, int node, const char *property, return -FDT_ERR_NOTFOUND; }
+int fdt_get_string_index(const void *fdt, int node, const char *property, + int index, const char **output) +{ + const char *list; + int length, i; + + list = fdt_getprop(fdt, node, property, &length); + + for (i = 0; i < length; i++) { + int len = strlen(list); + + if (index == 0) { + *output = list; + return 0; + } + + list += len + 1; + i += len; + index--; + } + + return FDT_ERR_NOTFOUND; +} + +int fdt_get_string(const void *fdt, int node, const char *property, + const char **output) +{ + return fdt_get_string_index(fdt, node, property, 0, output); +} + int fdt_node_check_compatible(const void *fdt, int nodeoffset, const char *compatible) {