dtoc: Make is_phandle() a member function

This function will need to have access to class members once we enhance it
to support multiple phandle values. In preparation for that, move it into
the class.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/tools/dtoc/dtb_platdata.py b/tools/dtoc/dtb_platdata.py
index 705ab27..a483d6c 100644
--- a/tools/dtoc/dtb_platdata.py
+++ b/tools/dtoc/dtb_platdata.py
@@ -116,21 +116,6 @@
         compat, aliases = compat[0], compat[1:]
     return conv_name_to_c(compat), [conv_name_to_c(a) for a in aliases]
 
-def is_phandle(prop):
-    """Check if a node contains phandles
-
-    We have no reliable way of detecting whether a node uses a phandle
-    or not. As an interim measure, use a list of known property names.
-
-    Args:
-        prop: Prop object to check
-    Return:
-        True if the object value contains phandles, else False
-    """
-    if prop.name in ['clocks']:
-        return True
-    return False
-
 
 class DtbPlatdata(object):
     """Provide a means to convert device tree binary data to platform data
@@ -196,6 +181,21 @@
         self._lines = []
         return lines
 
+    def is_phandle(self, prop):
+	"""Check if a node contains phandles
+
+	We have no reliable way of detecting whether a node uses a phandle
+	or not. As an interim measure, use a list of known property names.
+
+	Args:
+	    prop: Prop object to check
+	Return:
+	    True if the object value contains phandles, else False
+	"""
+	if prop.name in ['clocks']:
+	    return True
+	return False
+
     def scan_dtb(self):
         """Scan the device tree to obtain a tree of nodes and properties
 
@@ -359,7 +359,7 @@
                 if pname in PROP_IGNORE_LIST or pname[0] == '#':
                     continue
                 if isinstance(prop.value, list):
-                    if is_phandle(prop):
+                    if self.is_phandle(prop):
                         # Process the list as pairs of (phandle, id)
                         value_it = iter(prop.value)
                         for phandle_cell, _ in zip(value_it, value_it):
@@ -383,7 +383,7 @@
             self.out('struct %s%s {\n' % (STRUCT_PREFIX, name))
             for pname in sorted(structs[name]):
                 prop = structs[name][pname]
-                if is_phandle(prop):
+                if self.is_phandle(prop):
                     # For phandles, include a reference to the target
                     self.out('\t%s%s[%d]' % (tab_to(2, 'struct phandle_2_cell'),
                                              conv_name_to_c(prop.name),
@@ -423,7 +423,7 @@
                 vals = []
                 # For phandles, output a reference to the platform data
                 # of the target node.
-                if is_phandle(prop):
+                if self.is_phandle(prop):
                     # Process the list as pairs of (phandle, id)
                     value_it = iter(prop.value)
                     for phandle_cell, id_cell in zip(value_it, value_it):