From: Thierry Reding <treding@xxxxxxxxxx>
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 <sjg@xxxxxxxxxxxx>
Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
---
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 */
/**********************************************************************/
--
2.8.2
--
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