dtoc: Add a function to obtain a list of phandles

Add a function which can decode a property containing a list of phandles.
This is useful for finding nodes linked to a property. Also provide a way
to look up a single phandle and get the Fdt object from a Node.

Signed-off-by: Simon Glass <sjg@chromium.org>

tools/dtoc/fdt.py

@@ -181,6 +181,14 @@ class Node:
         self.subnodes = []
         self.props = {}
 
+    def GetFdt(self):
+        """Get the Fdt object for this node
+
+        Returns:
+            Fdt object
+        """
+        return self._fdt
+
     def FindNode(self, name):
         """Find a node given its name
 
@@ -314,6 +322,17 @@ class Fdt:
             with open(self._fname) as fd:
                 self._fdt_obj = libfdt.Fdt(fd.read())
 
+    def LookupPhandle(self, phandle):
+        """Look up a phandle
+
+        Args:
+            phandle: Phandle to look up (int)
+
+        Returns:
+            Node object the phandle points to
+        """
+        return self.phandle_to_node.get(phandle)
+
     def Scan(self, root='/'):
         """Scan a device tree, building up a tree of Node objects