From aac07d49d00b4bc8ca3f4aca0f3ad26385fb1d37 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Thu, 4 Sep 2014 16:27:24 -0600 Subject: dm: fdt: Add a function to look up a chosen node Within /chosen we may have a node which points to another node, similar to how /aliases works. Add a helper function to do this lookup. Signed-off-by: Simon Glass --- include/fdtdec.h | 12 ++++++++++++ lib/fdtdec.c | 15 +++++++++++++++ 2 files changed, 27 insertions(+) diff --git a/include/fdtdec.h b/include/fdtdec.h index 856e6cf..4f5aafb 100644 --- a/include/fdtdec.h +++ b/include/fdtdec.h @@ -374,6 +374,18 @@ int fdtdec_get_alias_seq(const void *blob, const char *base, int node, */ int fdtdec_get_alias_node(const void *blob, const char *name); +/** + * Get the offset of the given chosen node + * + * This looks up a property in /chosen containing the path to another node, + * then finds the offset of that node. + * + * @param blob Device tree blob (if NULL, then error is returned) + * @param name Property name, e.g. "stdout-path" + * @return Node offset referred to by that chosen node, or -ve FDT_ERR_... + */ +int fdtdec_get_chosen_node(const void *blob, const char *name); + /* * Get the name for a compatible ID * diff --git a/lib/fdtdec.c b/lib/fdtdec.c index eb5aa20..2b08be2 100644 --- a/lib/fdtdec.c +++ b/lib/fdtdec.c @@ -380,6 +380,21 @@ int fdtdec_get_alias_node(const void *blob, const char *name) return fdt_path_offset(blob, prop); } +int fdtdec_get_chosen_node(const void *blob, const char *name) +{ + const char *prop; + int chosen_node; + int len; + + if (!blob) + return -FDT_ERR_NOTFOUND; + chosen_node = fdt_path_offset(blob, "/chosen"); + prop = fdt_getprop(blob, chosen_node, name, &len); + if (!prop) + return -FDT_ERR_NOTFOUND; + return fdt_path_offset(blob, prop); +} + int fdtdec_check_fdt(void) { /* -- cgit v1.1