Add a function to retrieve the highest phandle in a given device tree.
Signed-off-by: Maxime Ripard maxime.ripard@free-electrons.com --- include/libfdt.h | 13 +++++++++++++ lib/libfdt/fdt_ro.c | 15 +++++++++++++++ 2 files changed, 28 insertions(+)
diff --git a/include/libfdt.h b/include/libfdt.h index 4e8eb9ede3a4..1e01b2c7ebdf 100644 --- a/include/libfdt.h +++ b/include/libfdt.h @@ -284,6 +284,19 @@ int fdt_move(const void *fdt, void *buf, int bufsize); const char *fdt_string(const void *fdt, int stroffset);
/** + * fdt_get_max_phandle - retrieves the highest phandle in a tree + * @fdt: pointer to the device tree blob + * + * fdt_get_max_phandle retrieves the highest phandlle in the given + * device tree + * + * returns: + * the highest phandle on success + * 0, if an error occured + */ +uint32_t fdt_get_max_phandle(const void *fdt); + +/** * fdt_num_mem_rsv - retrieve the number of memory reserve map entries * @fdt: pointer to the device tree blob * diff --git a/lib/libfdt/fdt_ro.c b/lib/libfdt/fdt_ro.c index 7b0777b67eb3..9130ce718965 100644 --- a/lib/libfdt/fdt_ro.c +++ b/lib/libfdt/fdt_ro.c @@ -47,6 +47,21 @@ static int _fdt_string_eq(const void *fdt, int stroffset, return (strnlen(p, len + 1) == len) && (memcmp(p, s, len) == 0); }
+uint32_t fdt_get_max_phandle(const void *fdt) +{ + uint32_t max_phandle = 0, phandle; + int offset; + + for (offset = fdt_next_node(fdt, -1, NULL); offset >= 0; + offset = fdt_next_node(fdt, offset, NULL)) { + phandle = fdt_get_phandle(fdt, offset); + if (phandle > max_phandle) + max_phandle = phandle; + } + + return max_phandle; +} + int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size) { FDT_CHECK_HEADER(fdt);