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
 

tools/dtoc/fdt_util.py

@@ -171,6 +171,24 @@ def GetByte(node, propname, default=None):
                          (node.name, propname, len(value), 1))
     return ord(value[0])
 
+def GetPhandleList(node, propname):
+    """Get a list of phandles from a property
+
+    Args:
+        node: Node object to read from
+        propname: property name to read
+
+    Returns:
+        List of phandles read, each an integer
+    """
+    prop = node.props.get(propname)
+    if not prop:
+        return None
+    value = prop.value
+    if not isinstance(value, list):
+        value = [value]
+    return [fdt32_to_cpu(v) for v in value]
+
 def GetDatatype(node, propname, datatype):
     """Get a value of a given type from a property
 

tools/dtoc/test_fdt.py

@@ -115,6 +115,9 @@ class TestFdt(unittest.TestCase):
             fdt.CheckErr(-libfdt.NOTFOUND, 'hello')
         self.assertIn('FDT_ERR_NOTFOUND: hello', str(e.exception))
 
+    def testGetFdt(self):
+        node = self.dtb.GetNode('/spl-test')
+        self.assertEqual(self.dtb, node.GetFdt())
 
 class TestNode(unittest.TestCase):
     """Test operation of the Node class"""
@@ -188,6 +191,14 @@ class TestNode(unittest.TestCase):
         self.assertIn("Internal error, property 'notstring' missing, offset ",
                       str(e.exception))
 
+    def testLookupPhandle(self):
+        """Test looking up a single phandle"""
+        dtb = fdt.FdtScan('tools/dtoc/dtoc_test_phandle.dts')
+        node = dtb.GetNode('/phandle-source2')
+        prop = node.props['clocks']
+        target = dtb.GetNode('/phandle-target')
+        self.assertEqual(target, dtb.LookupPhandle(fdt32_to_cpu(prop.value)))
+
 
 class TestProp(unittest.TestCase):
     """Test operation of the Prop class"""
@@ -394,6 +405,15 @@ class TestFdtUtil(unittest.TestCase):
         self.assertIn("property 'intval' has length 4, expecting 1",
                       str(e.exception))
 
+    def testGetPhandleList(self):
+        dtb = fdt.FdtScan('tools/dtoc/dtoc_test_phandle.dts')
+        node = dtb.GetNode('/phandle-source2')
+        self.assertEqual([1], fdt_util.GetPhandleList(node, 'clocks'))
+        node = dtb.GetNode('/phandle-source')
+        self.assertEqual([1, 2, 11, 3, 12, 13, 1],
+                         fdt_util.GetPhandleList(node, 'clocks'))
+        self.assertEqual(None, fdt_util.GetPhandleList(node, 'missing'))
+
     def testGetDataType(self):
         self.assertEqual(1, fdt_util.GetDatatype(self.node, 'intval', int))
         self.assertEqual('message', fdt_util.GetDatatype(self.node, 'stringval',