From 9c6098685a1d5df72da61ff7838ebb1524796869 Mon Sep 17 00:00:00 2001 From: Shannon Zhao Date: Thu, 7 Apr 2016 20:03:33 +0800 Subject: [PATCH] FDT: Add a helper to get the subnode by given name Sometimes it needs to check if there is a subnode of given node in FDT by given name. Introduce this helper to get the subnode if it exists. CC: Rob Herring Signed-off-by: Shannon Zhao Acked-by: Stefano Stabellini Acked-by: Rob Herring Tested-by: Julien Grall --- drivers/of/fdt.c | 13 +++++++++++++ include/linux/of_fdt.h | 2 ++ 2 files changed, 15 insertions(+) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 33daffc4392c..0e02947a8a7a 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -743,6 +743,19 @@ int __init of_scan_flat_dt(int (*it)(unsigned long node, return rc; } +/** + * of_get_flat_dt_subnode_by_name - get the subnode by given 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) +{ + return fdt_subnode_offset(initial_boot_params, node, uname); +} + /** * of_get_flat_dt_root - find the root node in the flat blob */ diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index 901ec01c9fba..26c3302ae58f 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -53,6 +53,8 @@ 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); -- 2.20.1