This allows use to replace code like this:
for (ndepth = 0, count = 0, noffset = fdt_next_node(fit, images_noffset, &ndepth); (noffset >= 0) && (ndepth > 0); noffset = fdt_next_node(fit, noffset, &ndepth)) { if (ndepth == 1) ...
with:
for (ndepth = 0, noffset = fdt_next_subnode(fit, image_noffset, &ndepth); noffset >= 0; noffset = fdt_next_subnode(fit, noffset, &ndepth)) {
which is slightly better, and doesn't require two levels of indentation for code in the loop.
Signed-off-by: Simon Glass sjg@chromium.org --- Changes in v2: None
include/libfdt.h | 17 +++++++++++++++++ lib/libfdt/fdt.c | 12 ++++++++++++ 2 files changed, 29 insertions(+)
diff --git a/include/libfdt.h b/include/libfdt.h index fc7f75b..50c90d6 100644 --- a/include/libfdt.h +++ b/include/libfdt.h @@ -136,6 +136,23 @@ uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset);
int fdt_next_node(const void *fdt, int offset, int *depth);
+/** + * fdt_next_subnode() - get offset of next direct child + * + * Set depth to 0, offset to parent, then call this function repeatedly + * to get direct subnodes of a parent node. + * + * @fdt: FDT blob + * @offset: Set this to offset of parent for the first call. For + * subsquent calls, pass in the value returns from the last + * call. + * @depth: Used internally to monitor depth - set this to 0 for the + * first call. + * @return offset of next subnode, or -FDT_ERR_NOTFOUND if there are no more + * children + */ +int fdt_next_subnode(const void *fdt, int offset, int *depth); + /**********************************************************************/ /* General functions */ /**********************************************************************/ diff --git a/lib/libfdt/fdt.c b/lib/libfdt/fdt.c index 387e354..cd86811 100644 --- a/lib/libfdt/fdt.c +++ b/lib/libfdt/fdt.c @@ -202,6 +202,18 @@ int fdt_next_node(const void *fdt, int offset, int *depth) return offset; }
+int fdt_next_subnode(const void *fdt, int offset, int *depth) +{ + /* Loop until we find a direct child of the parent (depth == 1) */ + do { + offset = fdt_next_node(fdt, offset, depth); + if (offset < 0 || *depth < 1) + return -FDT_ERR_NOTFOUND; + } while (*depth > 1); + + return offset; +} + const char *_fdt_find_string(const char *strtab, int tabsize, const char *s) { int len = strlen(s) + 1;