pylibfdt: Add support for fdt_parent_offset()

Add this into the class to simplify use of this function.

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

pylibfdt/libfdt.i

@@ -360,6 +360,21 @@ class Fdt:
         """
         return fdt_get_phandle(self._fdt, nodeoffset)
 
+    def parent_offset(self, nodeoffset, quiet=()):
+        """Get the offset of a node's parent
+
+        Args:
+            nodeoffset: Node offset to check
+            quiet: Errors to ignore (empty to raise on all errors)
+
+        Returns:
+            The offset of the parent node, if any
+
+        Raises:
+            FdtException if no parent found or other error occurs
+        """
+        return check_err(fdt_parent_offset(self._fdt, nodeoffset), quiet)
+
 
 class Property:
     """Holds a device tree property name and value.

tests/pylibfdt_tests.py

@@ -295,5 +295,18 @@ class PyLibfdtTests(unittest.TestCase):
         node2 = self.fdt.path_offset('/subnode@2')
         self.assertEquals(0x2000, self.fdt.get_phandle(node2))
 
+    def testParentOffset(self):
+        """Test for the parent_offset() method"""
+        self.assertEquals(-libfdt.NOTFOUND,
+                          self.fdt.parent_offset(0, QUIET_NOTFOUND))
+        with self.assertRaises(FdtException) as e:
+            self.fdt.parent_offset(0)
+        self.assertEquals(e.exception.err, -libfdt.NOTFOUND)
+
+        node1 = self.fdt.path_offset('/subnode@2')
+        self.assertEquals(0, self.fdt.parent_offset(node1))
+        node2 = self.fdt.path_offset('/subnode@2/subsubnode@0')
+        self.assertEquals(node1, self.fdt.parent_offset(node2))
+
 if __name__ == "__main__":
     unittest.main()