dtoc: Add methods for adding and updating properties

Add a few more functions which allow creating and modifying property
values. If only we could do this so easily in the real world.

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

tools/dtoc/fdt.py

@@ -175,6 +175,16 @@ class Prop:
         self.type = TYPE_INT
         self.dirty = True
 
+    def SetData(self, bytes):
+        """Set the value of a property as bytes
+
+        Args:
+            bytes: New property value to set
+        """
+        self.bytes = str(bytes)
+        self.type, self.value = self.BytesToValue(bytes)
+        self.dirty = True
+
     def Sync(self, auto_resize=False):
         """Sync property changes back to the device tree
 
@@ -326,18 +336,78 @@ class Node:
         """
         self.props[prop_name] = Prop(self, None, prop_name, '\0' * 4)
 
+    def AddEmptyProp(self, prop_name, len):
+        """Add a property with a fixed data size, for filling in later
+
+        The device tree is marked dirty so that the value will be written to
+        the blob on the next sync.
+
+        Args:
+            prop_name: Name of property
+            len: Length of data in property
+        """
+        value = chr(0) * len
+        self.props[prop_name] = Prop(self, None, prop_name, value)
+
     def SetInt(self, prop_name, val):
         """Update an integer property int the device tree.
 
         This is not allowed to change the size of the FDT.
 
+        The device tree is marked dirty so that the value will be written to
+        the blob on the next sync.
+
         Args:
             prop_name: Name of property
             val: Value to set
         """
         self.props[prop_name].SetInt(val)
 
+    def SetData(self, prop_name, val):
+        """Set the data value of a property
+
+        The device tree is marked dirty so that the value will be written to
+        the blob on the next sync.
+
+        Args:
+            prop_name: Name of property to set
+            val: Data value to set
+        """
+        self.props[prop_name].SetData(val)
+
+    def SetString(self, prop_name, val):
+        """Set the string value of a property
+
+        The device tree is marked dirty so that the value will be written to
+        the blob on the next sync.
+
+        Args:
+            prop_name: Name of property to set
+            val: String value to set (will be \0-terminated in DT)
+        """
+        self.props[prop_name].SetData(val + chr(0))
+
+    def AddString(self, prop_name, val):
+        """Add a new string property to a node
+
+        The device tree is marked dirty so that the value will be written to
+        the blob on the next sync.
+
+        Args:
+            prop_name: Name of property to add
+            val: String value of property
+        """
+        self.props[prop_name] = Prop(self, None, prop_name, val + chr(0))
+
     def AddSubnode(self, name):
+        """Add a new subnode to the node
+
+        Args:
+            name: name of node to add
+
+        Returns:
+            New subnode that was created
+        """
         path = self.path + '/' + name
         subnode = Node(self._fdt, self, None, name, path)
         self.subnodes.append(subnode)

tools/dtoc/test_fdt.py

@@ -352,6 +352,7 @@ class TestProp(unittest.TestCase):
         with self.assertRaises(libfdt.FdtException) as e:
             self.dtb.Sync(auto_resize=False)
         self.assertIn('FDT_ERR_NOSPACE', str(e.exception))
+        self.dtb.Sync(auto_resize=True)
 
     def testAddNode(self):
         self.fdt.pack()
@@ -364,6 +365,48 @@ class TestProp(unittest.TestCase):
         offset = self.fdt.path_offset('/spl-test/subnode')
         self.assertTrue(offset > 0)
 
+    def testAddMore(self):
+        """Test various other methods for adding and setting properties"""
+        self.node.AddZeroProp('one')
+        self.dtb.Sync(auto_resize=True)
+        data = self.fdt.getprop(self.node.Offset(), 'one')
+        self.assertEqual(0, fdt32_to_cpu(data))
+
+        self.node.SetInt('one', 1)
+        self.dtb.Sync(auto_resize=False)
+        data = self.fdt.getprop(self.node.Offset(), 'one')
+        self.assertEqual(1, fdt32_to_cpu(data))
+
+        val = '123' + chr(0) + '456'
+        self.node.AddString('string', val)
+        self.dtb.Sync(auto_resize=True)
+        data = self.fdt.getprop(self.node.Offset(), 'string')
+        self.assertEqual(val + '\0', data)
+
+        self.fdt.pack()
+        self.node.SetString('string', val + 'x')
+        with self.assertRaises(libfdt.FdtException) as e:
+            self.dtb.Sync(auto_resize=False)
+        self.assertIn('FDT_ERR_NOSPACE', str(e.exception))
+        self.node.SetString('string', val[:-1])
+
+        prop = self.node.props['string']
+        prop.SetData(val)
+        self.dtb.Sync(auto_resize=False)
+        data = self.fdt.getprop(self.node.Offset(), 'string')
+        self.assertEqual(val, data)
+
+        self.node.AddEmptyProp('empty', 5)
+        self.dtb.Sync(auto_resize=True)
+        prop = self.node.props['empty']
+        prop.SetData(val)
+        self.dtb.Sync(auto_resize=False)
+        data = self.fdt.getprop(self.node.Offset(), 'empty')
+        self.assertEqual(val, data)
+
+        self.node.SetData('empty', '123')
+        self.assertEqual('123', prop.bytes)
+
 
 class TestFdtUtil(unittest.TestCase):
     """Tests for the fdt_util module