From da8eff9943780d1e294da14f096398196316f6d6 Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Wed, 27 Jul 2016 14:55:53 +0200 Subject: libfdt: Add a subnodes iterator macro 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. Signed-off-by: Thierry Reding Signed-off-by: Maxime Ripard Signed-off-by: David Gibson --- cpukit/include/libfdt.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'cpukit/include/libfdt.h') diff --git a/cpukit/include/libfdt.h b/cpukit/include/libfdt.h index 36222fd4a6..911e548163 100644 --- a/cpukit/include/libfdt.h +++ b/cpukit/include/libfdt.h @@ -168,6 +168,34 @@ 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 + * + * @node: child node (int, lvalue) + * @fdt: FDT blob (const void *) + * @parent: parent node (int) + * + * This is actually a wrapper around a for loop and would be used like so: + * + * fdt_for_each_subnode(node, fdt, parent) { + * Use node + * ... + * } + * + * if ((node < 0) && (node != -FDT_ERR_NOT_FOUND)) { + * Error handling + * } + * + * Note that this is implemented as a macro and @node is used as + * iterator in the loop. The parent variable be constant or even a + * literal. + * + */ +#define fdt_for_each_subnode(node, fdt, parent) \ + for (node = fdt_first_subnode(fdt, parent); \ + node >= 0; \ + node = fdt_next_subnode(fdt, node)) + /**********************************************************************/ /* General functions */ /**********************************************************************/ -- cgit v1.2.3