[PATCH v4 16/17] FDT: Add a helper to get specified name subnode
From: Shannon Zhao <hidden>
Date: 2016-02-05 03:08:08
Also in:
linux-devicetree, linux-efi, lkml
Subsystem:
open firmware and flattened device tree, the rest · Maintainers:
Rob Herring, Saravana Kannan, Linus Torvalds
From: Shannon Zhao <redacted> 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 <redacted> --- CC: Rob Herring <robh@kernel.org> --- 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);
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2.0.4