pylibfdt: Add support for fdt_next_node()

This function requires a bit of typemap effort to get the depth parameter
to work correctly. Add support for it, along with a test.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

pylibfdt/libfdt.i

@@ -185,6 +185,25 @@ class Fdt:
         """
         return bytearray(self._fdt)
 
+    def next_node(self, nodeoffset, depth, quiet=()):
+        """Find the next subnode
+
+        Args:
+            nodeoffset: Node offset of previous node
+            depth: The depth of the node at nodeoffset. This is used to
+                calculate the depth of the returned node
+            quiet: Errors to ignore (empty to raise on all errors)
+
+        Returns:
+            Typle:
+                Offset of the next node, if any, else a -ve error
+                Depth of the returned node, if any, else undefined
+
+        Raises:
+            FdtException if no more nodes found or other error occurs
+        """
+        return check_err(fdt_next_node(self._fdt, nodeoffset, depth), quiet)
+
     def first_subnode(self, nodeoffset, quiet=()):
         """Find the first subnode of a parent node
 
@@ -466,6 +485,7 @@ typedef int fdt32_t;
         fdt = fdt; /* avoid unused variable warning */
 }
 
+/* typemap used for fdt_get_property_by_offset() */
 %typemap(out) (struct fdt_property *) {
 	PyObject *buff;
 
@@ -488,6 +508,19 @@ typedef int fdt32_t;
 		$result = Py_BuildValue("s#", $1, *arg4);
 }
 
+/* typemaps used for fdt_next_node() */
+%typemap(in, numinputs=1) int *depth (int depth) {
+   depth = (int) PyInt_AsLong($input);
+   $1 = &depth;
+}
+
+%typemap(argout) int *depth {
+        PyObject *val = Py_BuildValue("i", *arg$argnum);
+        resultobj = SWIG_Python_AppendOutput(resultobj, val);
+}
+
+%apply int *depth { int *depth };
+
 /* We have both struct fdt_property and a function fdt_property() */
 %warnfilter(302) fdt_property;
 

tests/pylibfdt_tests.py

@@ -220,6 +220,24 @@ class PyLibfdtTests(unittest.TestCase):
         self.assertEquals(libfdt.strerror(-libfdt.NOTFOUND),
                           'FDT_ERR_NOTFOUND')
 
+    def testNextNodeOffset(self):
+        """Check that we can walk through nodes"""
+        node_list = []
+        node = 0
+        depth = 0
+        while depth >= 0:
+            node_list.append([depth, self.fdt.get_name(node)])
+            node, depth = self.fdt.next_node(node, depth, (libfdt.BADOFFSET,))
+        self.assertEquals(node_list, [
+            [0, ''],
+            [1, 'subnode@1'],
+            [2, 'subsubnode'],
+            [2, 'ss1'],
+            [1, 'subnode@2'],
+            [2, 'subsubnode@0'],
+            [2, 'ss2'],
+            ])
+
     def testFirstNextSubnodeOffset(self):
         """Check that we can walk through subnodes"""
         node_list = []