On Tue, Jul 05, 2016 at 10:26:39AM +0200, Maxime Ripard wrote:
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
include/libfdt.h | 13 +++++++++++++ lib/libfdt/fdt_ro.c | 26 ++++++++++++++++++++++++++ 2 files changed, 39 insertions(+)
diff --git a/include/libfdt.h b/include/libfdt.h index fbbe58ceb3f1..4643be5adf39 100644 --- a/include/libfdt.h +++ b/include/libfdt.h @@ -283,6 +283,19 @@ 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 phandle in the given
- device tree
- returns:
the highest phandle on success
0, if an error occurred
This will also return 0 if there are no phandles in the entire tree, which isn't exactly an error.
- */
+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 12214c2dc2b5..503150ef1dc5 100644 --- a/lib/libfdt/fdt_ro.c +++ b/lib/libfdt/fdt_ro.c @@ -47,6 +47,32 @@ 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;
- 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;
It might be worth pointing out that *any* -1 phandle in the tree counts as an error. Since -1 phandles are sometimes used as a placeholder, ignoring them might be a better option.
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);