[PATCH] fdt: Add a subnodes iterator macro
From: Maxime Ripard <hidden>
Date: 2016-05-27 08:28:45
Subsystem:
the rest · Maintainer:
Linus Torvalds
From: Thierry Reding <redacted> The fdt_for_each_subnode() iterator macro provided by this patch can be used to iterate over a device tree node's subnodes. At each iteration a loop variable will be set to the next subnode. Acked-by: Simon Glass <redacted> Signed-off-by: Thierry Reding <redacted> --- libfdt/libfdt.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+)
diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h
index 2dfc6d9e5ce7..f3cbb637be41 100644
--- a/libfdt/libfdt.h
+++ b/libfdt/libfdt.h@@ -163,6 +163,31 @@ int fdt_first_subnode(const void *fdt, int offset); */ int fdt_next_subnode(const void *fdt, int offset); +/** + * fdt_for_each_subnode - iterate over all subnodes of a parent + * + * This is actually a wrapper around a for loop and would be used like so: + * + * fdt_for_each_subnode(fdt, node, parent) { + * ... + * use node + * ... + * } + * + * Note that this is implemented as a macro and node is used as iterator in + * the loop. It should therefore be a locally allocated variable. The parent + * variable on the other hand is never modified, so it can be constant or + * even a literal. + * + * @fdt: FDT blob (const void *) + * @node: child node (int) + * @parent: parent node (int) + */ +#define fdt_for_each_subnode(fdt, node, parent) \ + for (node = fdt_first_subnode(fdt, parent); \ + node >= 0; \ + node = fdt_next_subnode(fdt, node)) + /**********************************************************************/ /* General functions */ /**********************************************************************/
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2.8.2