From: Shannon Zhao <shannon.zhao@xxxxxxxxxx> Sometimes it needs to check if there is a node in FDT by full path. Introduce this helper to get the specified name subnode if it exists. Signed-off-by: Shannon Zhao <shannon.zhao@xxxxxxxxxx> --- CC: Rob Herring <robh@xxxxxxxxxx> --- drivers/of/fdt.c | 25 +++++++++++++++++++++++++ include/linux/of_fdt.h | 2 ++ 2 files changed, 27 insertions(+) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 655f79d..eacb188 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -645,6 +645,31 @@ int __init of_scan_flat_dt(int (*it)(unsigned long node, } /** + * of_get_flat_dt_subnode_by_name - get subnode of specified node by name + * + * @node: the parent node + * @uname: the name of subnode + * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none + */ + +int of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname) +{ + const void *blob = initial_boot_params; + int offset; + const char *pathp; + + for (offset = fdt_first_subnode(blob, node); + offset >= 0; + offset = fdt_next_subnode(blob, offset)) { + pathp = fdt_get_name(blob, offset, NULL); + if (strcmp(pathp, uname) == 0) + return offset; + } + + return -FDT_ERR_NOTFOUND; +} + +/** * of_get_flat_dt_root - find the root node in the flat blob */ unsigned long __init of_get_flat_dt_root(void) diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index df9ef38..fc28162 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -52,6 +52,8 @@ extern char __dtb_end[]; extern int of_scan_flat_dt(int (*it)(unsigned long node, const char *uname, int depth, void *data), void *data); +extern int of_get_flat_dt_subnode_by_name(unsigned long node, + const char *uname); extern const void *of_get_flat_dt_prop(unsigned long node, const char *name, int *size); extern int of_flat_dt_is_compatible(unsigned long node, const char *name); -- 2.0.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html