[PATCH v3 3/6] libfdt: Add max phandle retrieval function
From: Maxime Ripard <hidden>
Date: 2016-07-20 14:20:41
Subsystem:
the rest · Maintainer:
Linus Torvalds
Add a function to retrieve the highest phandle in a given device tree. Acked-by: Simon Glass <redacted> Reviewed-by: Stefan Agner <redacted> Reviewed-by: David Gibson <redacted> Signed-off-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org> --- libfdt/fdt_ro.c | 26 ++++++++++++++++++++++++++ libfdt/libfdt.h | 15 +++++++++++++++ tests/get_phandle.c | 6 ++++++ 3 files changed, 47 insertions(+)
diff --git a/libfdt/fdt_ro.c b/libfdt/fdt_ro.c
index 50cce864283c..04590984bd51 100644
--- a/libfdt/fdt_ro.c
+++ b/libfdt/fdt_ro.c@@ -88,6 +88,32 @@ static int _fdt_string_eq(const void *fdt, int stroffset, return (strlen(p) == 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 (uint32_t)-1; + + phandle = fdt_get_phandle(fdt, offset); + if (phandle == (uint32_t)-1) + continue; + + 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);
diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h
index cb2f080c81d4..1a14bc16b3d7 100644
--- a/libfdt/libfdt.h
+++ b/libfdt/libfdt.h@@ -285,6 +285,21 @@ 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. This will ignore badly formatted phandles, or phandles + * with a value of 0 or -1. + * + * returns: + * the highest phandle on success + * 0, if no phandle was found in the device tree + * -1, if an error occurred + */ +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/tests/get_phandle.c b/tests/get_phandle.c
index 2079591d4c49..22bd7b81b3f0 100644
--- a/tests/get_phandle.c
+++ b/tests/get_phandle.c@@ -44,6 +44,7 @@ static void check_phandle(void *fdt, const char *path, uint32_t checkhandle) int main(int argc, char *argv[]) { + uint32_t max; void *fdt; test_init(argc, argv);
@@ -53,5 +54,10 @@ int main(int argc, char *argv[]) check_phandle(fdt, "/subnode@2", PHANDLE_1); check_phandle(fdt, "/subnode@2/subsubnode@0", PHANDLE_2); + max = fdt_get_max_phandle(fdt); + if (max != PHANDLE_2) + FAIL("fdt_get_max_phandle returned 0x%x instead of 0x%x\n", + max, PHANDLE_2); + PASS(); }
--
2.9.0