libfdt: Add max phandle retrieval function
Add a function to retrieve the highest phandle in a given device tree.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Stefan Agner <stefan@agner.ch>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/lib/libfdt/fdt_ro.c b/lib/libfdt/fdt_ro.c
index 12214c2..503150e 100644
--- a/lib/libfdt/fdt_ro.c
+++ b/lib/libfdt/fdt_ro.c
@@ -47,6 +47,32 @@
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;
+ int offset;
+
+ for (offset = fdt_next_node(fdt, -1, NULL);;
+ offset = fdt_next_node(fdt, offset, NULL)) {
+ uint32_t phandle;
+
+ if (offset == -FDT_ERR_NOTFOUND)
+ return max_phandle;
+
+ if (offset < 0)
+ return 0;
+
+ phandle = fdt_get_phandle(fdt, offset);
+ if (phandle == (uint32_t)-1)
+ return 0;
+
+ if (phandle > max_phandle)
+ max_phandle = phandle;
+ }
+
+ return 0;
+}
+
int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size)
{
FDT_CHECK_HEADER(fdt);