dtoc: Fix pylint warnings

Unfortunately I neglected to run pylint on this tool with its initial
submission. Fix the warnings.

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

2 files changed, 144 insertions, 131 deletions

diff --git a/tools/dtoc/dtb_platdata.py b/tools/dtoc/dtb_platdata.py
index 94db274c09..75adf48dea 100644
--- a/tools/dtoc/dtb_platdata.py
+++ b/tools/dtoc/dtb_platdata.py
@@ -6,7 +6,14 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
+"""Device tree to platform data class
+
+This supports converting device tree data to C structures definitions and
+static data.
+"""
+
 import copy
+import sys
 
 import fdt
 import fdt_util
@@ -31,12 +38,12 @@ TYPE_NAMES = {
     fdt.TYPE_BYTE: 'unsigned char',
     fdt.TYPE_STRING: 'const char *',
     fdt.TYPE_BOOL: 'bool',
-};
+}
 
 STRUCT_PREFIX = 'dtd_'
 VAL_PREFIX = 'dtv_'
 
-def Conv_name_to_c(name):
+def conv_name_to_c(name):
     """Convert a device-tree name to a C identifier
 
     Args:
@@ -44,19 +51,29 @@ def Conv_name_to_c(name):
     Return:
         String containing the C version of this name
     """
-    str = name.replace('@', '_at_')
-    str = str.replace('-', '_')
-    str = str.replace(',', '_')
-    str = str.replace('.', '_')
-    str = str.replace('/', '__')
-    return str
-
-def TabTo(num_tabs, str):
-    if len(str) >= num_tabs * 8:
-        return str + ' '
-    return str + '\t' * (num_tabs - len(str) // 8)
-
-class DtbPlatdata:
+    new = name.replace('@', '_at_')
+    new = new.replace('-', '_')
+    new = new.replace(',', '_')
+    new = new.replace('.', '_')
+    new = new.replace('/', '__')
+    return new
+
+def tab_to(num_tabs, line):
+    """Append tabs to a line of text to reach a tab stop.
+
+    Args:
+        num_tabs: Tab stop to obtain (0 = column 0, 1 = column 8, etc.)
+        line: Line of text to append to
+
+    Returns:
+        line with the correct number of tabs appeneded. If the line already
+        extends past that tab stop then a single space is appended.
+    """
+    if len(line) >= num_tabs * 8:
+        return line + ' '
+    return line + '\t' * (num_tabs - len(line) // 8)
+
+class DtbPlatdata(object):
     """Provide a means to convert device tree binary data to platform data
 
     The output of this process is C structures which can be used in space-
@@ -64,28 +81,29 @@ class DtbPlatdata:
     code is not affordable.
 
     Properties:
-        fdt: Fdt object, referencing the device tree
+        _fdt: Fdt object, referencing the device tree
         _dtb_fname: Filename of the input device tree binary file
         _valid_nodes: A list of Node object with compatible strings
         _options: Command-line options
-        _phandle_node: A dict of nodes indexed by phandle number (1, 2...)
+        _phandle_nodes: A dict of nodes indexed by phandle number (1, 2...)
         _outfile: The current output file (sys.stdout or a real file)
         _lines: Stashed list of output lines for outputting in the future
-        _phandle_node: A dict of Nodes indexed by phandle (an integer)
+        _phandle_nodes: A dict of Nodes indexed by phandle (an integer)
     """
     def __init__(self, dtb_fname, options):
+        self._fdt = None
         self._dtb_fname = dtb_fname
         self._valid_nodes = None
         self._options = options
-        self._phandle_node = {}
+        self._phandle_nodes = {}
         self._outfile = None
         self._lines = []
         self._aliases = {}
 
-    def SetupOutput(self, fname):
+    def setup_output(self, fname):
         """Set up the output destination
 
-        Once this is done, future calls to self.Out() will output to this
+        Once this is done, future calls to self.out() will output to this
         file.
 
         Args:
@@ -96,23 +114,23 @@ class DtbPlatdata:
         else:
             self._outfile = open(fname, 'w')
 
-    def Out(self, str):
+    def out(self, line):
         """Output a string to the output file
 
         Args:
-            str: String to output
+            line: String to output
         """
-        self._outfile.write(str)
+        self._outfile.write(line)
 
-    def Buf(self, str):
+    def buf(self, line):
         """Buffer up a string to send later
 
         Args:
-            str: String to add to our 'buffer' list
+            line: String to add to our 'buffer' list
         """
-        self._lines.append(str)
+        self._lines.append(line)
 
-    def GetBuf(self):
+    def get_buf(self):
         """Get the contents of the output buffer, and clear it
 
         Returns:
@@ -122,7 +140,8 @@ class DtbPlatdata:
         self._lines = []
         return lines
 
-    def GetValue(self, type, value):
+    @staticmethod
+    def get_value(ftype, value):
         """Get a value as a C expression
 
         For integers this returns a byte-swapped (little-endian) hex string
@@ -134,16 +153,17 @@ class DtbPlatdata:
             type: Data type (fdt_util)
             value: Data value, as a string of bytes
         """
-        if type == fdt.TYPE_INT:
+        if ftype == fdt.TYPE_INT:
             return '%#x' % fdt_util.fdt32_to_cpu(value)
-        elif type == fdt.TYPE_BYTE:
+        elif ftype == fdt.TYPE_BYTE:
             return '%#x' % ord(value[0])
-        elif type == fdt.TYPE_STRING:
+        elif ftype == fdt.TYPE_STRING:
             return '"%s"' % value
-        elif type == fdt.TYPE_BOOL:
+        elif ftype == fdt.TYPE_BOOL:
             return 'true'
 
-    def GetCompatName(self, node):
+    @staticmethod
+    def get_compat_name(node):
         """Get a node's first compatible string as a C identifier
 
         Args:
@@ -153,59 +173,55 @@ class DtbPlatdata:
         """
         compat = node.props['compatible'].value
         aliases = []
-        if type(compat) == list:
+        if isinstance(compat, list):
             compat, aliases = compat[0], compat[1:]
-        return Conv_name_to_c(compat), [Conv_name_to_c(a) for a in aliases]
+        return conv_name_to_c(compat), [conv_name_to_c(a) for a in aliases]
 
-    def ScanDtb(self):
+    def scan_dtb(self):
         """Scan the device tree to obtain a tree of notes and properties
 
-        Once this is done, self.fdt.GetRoot() can be called to obtain the
+        Once this is done, self._fdt.GetRoot() can be called to obtain the
         device tree root node, and progress from there.
         """
-        self.fdt = fdt.FdtScan(self._dtb_fname)
+        self._fdt = fdt.FdtScan(self._dtb_fname)
+
+    def scan_node(self, root):
+        """Scan a node and subnodes to build a tree of node and phandle info
+
+        This adds each node to self._valid_nodes and each phandle to
+        self._phandle_nodes.
 
-    def ScanNode(self, root):
+        Args:
+            root: Root node for scan
+        """
         for node in root.subnodes:
             if 'compatible' in node.props:
                 status = node.props.get('status')
                 if (not self._options.include_disabled and not status or
-                    status.value != 'disabled'):
+                        status.value != 'disabled'):
                     self._valid_nodes.append(node)
                     phandle_prop = node.props.get('phandle')
                     if phandle_prop:
                         phandle = phandle_prop.GetPhandle()
-                        self._phandle_node[phandle] = node
+                        self._phandle_nodes[phandle] = node
 
             # recurse to handle any subnodes
-            self.ScanNode(node);
+            self.scan_node(node)
 
-    def ScanTree(self):
+    def scan_tree(self):
         """Scan the device tree for useful information
 
         This fills in the following properties:
-            _phandle_node: A dict of Nodes indexed by phandle (an integer)
+            _phandle_nodes: A dict of Nodes indexed by phandle (an integer)
             _valid_nodes: A list of nodes we wish to consider include in the
                 platform data
         """
-        self._phandle_node = {}
+        self._phandle_nodes = {}
         self._valid_nodes = []
-        return self.ScanNode(self.fdt.GetRoot());
-
-        for node in self.fdt.GetRoot().subnodes:
-            if 'compatible' in node.props:
-                status = node.props.get('status')
-                if (not self._options.include_disabled and not status or
-                    status.value != 'disabled'):
-                    node_list.append(node)
-                    phandle_prop = node.props.get('phandle')
-                    if phandle_prop:
-                        phandle = phandle_prop.GetPhandle()
-                        self._phandle_node[phandle] = node
-
-        self._valid_nodes = node_list
+        return self.scan_node(self._fdt.GetRoot())
 
-    def IsPhandle(self, prop):
+    @staticmethod
+    def is_phandle(prop):
         """Check if a node contains phandles
 
         We have no reliable way of detecting whether a node uses a phandle
@@ -220,7 +236,7 @@ class DtbPlatdata:
             return True
         return False
 
-    def ScanStructs(self):
+    def scan_structs(self):
         """Scan the device tree building up the C structures we will use.
 
         Build a dict keyed by C struct name containing a dict of Prop
@@ -233,7 +249,7 @@ class DtbPlatdata:
         """
         structs = {}
         for node in self._valid_nodes:
-            node_name, _ = self.GetCompatName(node)
+            node_name, _ = self.get_compat_name(node)
             fields = {}
 
             # Get a list of all the valid properties in this node.
@@ -257,20 +273,20 @@ class DtbPlatdata:
 
         upto = 0
         for node in self._valid_nodes:
-            node_name, _ = self.GetCompatName(node)
+            node_name, _ = self.get_compat_name(node)
             struct = structs[node_name]
             for name, prop in node.props.items():
                 if name not in PROP_IGNORE_LIST and name[0] != '#':
                     prop.Widen(struct[name])
             upto += 1
 
-            struct_name, aliases = self.GetCompatName(node)
+            struct_name, aliases = self.get_compat_name(node)
             for alias in aliases:
                 self._aliases[alias] = struct_name
 
         return structs
 
-    def ScanPhandles(self):
+    def scan_phandles(self):
         """Figure out what phandles each node uses
 
         We need to be careful when outputing nodes that use phandles since
@@ -286,104 +302,101 @@ class DtbPlatdata:
             for pname, prop in node.props.items():
                 if pname in PROP_IGNORE_LIST or pname[0] == '#':
                     continue
-                if type(prop.value) == list:
-                    if self.IsPhandle(prop):
+                if isinstance(prop.value, list):
+                    if self.is_phandle(prop):
                         # Process the list as pairs of (phandle, id)
-                        it = iter(prop.value)
-                        for phandle_cell, id_cell in zip(it, it):
+                        value_it = iter(prop.value)
+                        for phandle_cell, _ in zip(value_it, value_it):
                             phandle = fdt_util.fdt32_to_cpu(phandle_cell)
-                            id = fdt_util.fdt32_to_cpu(id_cell)
-                            target_node = self._phandle_node[phandle]
+                            target_node = self._phandle_nodes[phandle]
                             node.phandles.add(target_node)
 
 
-    def GenerateStructs(self, structs):
+    def generate_structs(self, structs):
         """Generate struct defintions for the platform data
 
         This writes out the body of a header file consisting of structure
         definitions for node in self._valid_nodes. See the documentation in
         README.of-plat for more information.
         """
-        self.Out('#include <stdbool.h>\n')
-        self.Out('#include <libfdt.h>\n')
+        self.out('#include <stdbool.h>\n')
+        self.out('#include <libfdt.h>\n')
 
         # Output the struct definition
         for name in sorted(structs):
-            self.Out('struct %s%s {\n' % (STRUCT_PREFIX, name));
+            self.out('struct %s%s {\n' % (STRUCT_PREFIX, name))
             for pname in sorted(structs[name]):
                 prop = structs[name][pname]
-                if self.IsPhandle(prop):
+                if self.is_phandle(prop):
                     # For phandles, include a reference to the target
-                    self.Out('\t%s%s[%d]' % (TabTo(2, 'struct phandle_2_cell'),
-                                             Conv_name_to_c(prop.name),
+                    self.out('\t%s%s[%d]' % (tab_to(2, 'struct phandle_2_cell'),
+                                             conv_name_to_c(prop.name),
                                              len(prop.value) / 2))
                 else:
                     ptype = TYPE_NAMES[prop.type]
-                    self.Out('\t%s%s' % (TabTo(2, ptype),
-                                         Conv_name_to_c(prop.name)))
-                    if type(prop.value) == list:
-                        self.Out('[%d]' % len(prop.value))
-                self.Out(';\n')
-            self.Out('};\n')
+                    self.out('\t%s%s' % (tab_to(2, ptype),
+                                         conv_name_to_c(prop.name)))
+                    if isinstance(prop.value, list):
+                        self.out('[%d]' % len(prop.value))
+                self.out(';\n')
+            self.out('};\n')
 
         for alias, struct_name in self._aliases.iteritems():
-            self.Out('#define %s%s %s%s\n'% (STRUCT_PREFIX, alias,
+            self.out('#define %s%s %s%s\n'% (STRUCT_PREFIX, alias,
                                              STRUCT_PREFIX, struct_name))
 
-    def OutputNode(self, node):
+    def output_node(self, node):
         """Output the C code for a node
 
         Args:
             node: node to output
         """
-        struct_name, _ = self.GetCompatName(node)
-        var_name = Conv_name_to_c(node.name)
-        self.Buf('static struct %s%s %s%s = {\n' %
-            (STRUCT_PREFIX, struct_name, VAL_PREFIX, var_name))
+        struct_name, _ = self.get_compat_name(node)
+        var_name = conv_name_to_c(node.name)
+        self.buf('static struct %s%s %s%s = {\n' %
+                 (STRUCT_PREFIX, struct_name, VAL_PREFIX, var_name))
         for pname, prop in node.props.items():
             if pname in PROP_IGNORE_LIST or pname[0] == '#':
                 continue
-            ptype = TYPE_NAMES[prop.type]
-            member_name = Conv_name_to_c(prop.name)
-            self.Buf('\t%s= ' % TabTo(3, '.' + member_name))
+            member_name = conv_name_to_c(prop.name)
+            self.buf('\t%s= ' % tab_to(3, '.' + member_name))
 
             # Special handling for lists
-            if type(prop.value) == list:
-                self.Buf('{')
+            if isinstance(prop.value, list):
+                self.buf('{')
                 vals = []
                 # For phandles, output a reference to the platform data
                 # of the target node.
-                if self.IsPhandle(prop):
+                if self.is_phandle(prop):
                     # Process the list as pairs of (phandle, id)
-                    it = iter(prop.value)
-                    for phandle_cell, id_cell in zip(it, it):
+                    value_it = iter(prop.value)
+                    for phandle_cell, id_cell in zip(value_it, value_it):
                         phandle = fdt_util.fdt32_to_cpu(phandle_cell)
-                        id = fdt_util.fdt32_to_cpu(id_cell)
-                        target_node = self._phandle_node[phandle]
-                        name = Conv_name_to_c(target_node.name)
-                        vals.append('{&%s%s, %d}' % (VAL_PREFIX, name, id))
+                        id_num = fdt_util.fdt32_to_cpu(id_cell)
+                        target_node = self._phandle_nodes[phandle]
+                        name = conv_name_to_c(target_node.name)
+                        vals.append('{&%s%s, %d}' % (VAL_PREFIX, name, id_num))
                 else:
                     for val in prop.value:
-                        vals.append(self.GetValue(prop.type, val))
-                self.Buf(', '.join(vals))
-                self.Buf('}')
+                        vals.append(self.get_value(prop.type, val))
+                self.buf(', '.join(vals))
+                self.buf('}')
             else:
-                self.Buf(self.GetValue(prop.type, prop.value))
-            self.Buf(',\n')
-        self.Buf('};\n')
+                self.buf(self.get_value(prop.type, prop.value))
+            self.buf(',\n')
+        self.buf('};\n')
 
         # Add a device declaration
-        self.Buf('U_BOOT_DEVICE(%s) = {\n' % var_name)
-        self.Buf('\t.name\t\t= "%s",\n' % struct_name)
-        self.Buf('\t.platdata\t= &%s%s,\n' % (VAL_PREFIX, var_name))
-        self.Buf('\t.platdata_size\t= sizeof(%s%s),\n' %
-                    (VAL_PREFIX, var_name))
-        self.Buf('};\n')
-        self.Buf('\n')
+        self.buf('U_BOOT_DEVICE(%s) = {\n' % var_name)
+        self.buf('\t.name\t\t= "%s",\n' % struct_name)
+        self.buf('\t.platdata\t= &%s%s,\n' % (VAL_PREFIX, var_name))
+        self.buf('\t.platdata_size\t= sizeof(%s%s),\n' % (VAL_PREFIX, var_name))
+        self.buf('};\n')
+        self.buf('\n')
 
-        self.Out(''.join(self.GetBuf()))
+        self.out(''.join(self.get_buf()))
 
-    def GenerateTables(self):
+    def generate_tables(self):
         """Generate device defintions for the platform data
 
         This writes out C platform data initialisation data and
@@ -393,10 +406,10 @@ class DtbPlatdata:
         See the documentation in doc/driver-model/of-plat.txt for more
         information.
         """
-        self.Out('#include <common.h>\n')
-        self.Out('#include <dm.h>\n')
-        self.Out('#include <dt-structs.h>\n')
-        self.Out('\n')
+        self.out('#include <common.h>\n')
+        self.out('#include <dm.h>\n')
+        self.out('#include <dt-structs.h>\n')
+        self.out('\n')
         nodes_to_output = list(self._valid_nodes)
 
         # Keep outputing nodes until there is none left
@@ -405,7 +418,7 @@ class DtbPlatdata:
             # Output all the node's dependencies first
             for req_node in node.phandles:
                 if req_node in nodes_to_output:
-                    self.OutputNode(req_node)
+                    self.output_node(req_node)
                     nodes_to_output.remove(req_node)
-            self.OutputNode(node)
+            self.output_node(node)
             nodes_to_output.remove(node)
diff --git a/tools/dtoc/dtoc.py b/tools/dtoc/dtoc.py
index 8fc717a92d..abda9191fa 100755
--- a/tools/dtoc/dtoc.py
+++ b/tools/dtoc/dtoc.py
@@ -53,16 +53,16 @@ if not args:
     raise ValueError('Please specify a command: struct, platdata')
 
 plat = dtb_platdata.DtbPlatdata(options.dtb_file, options)
-plat.ScanDtb()
-plat.ScanTree()
-plat.SetupOutput(options.output)
-structs = plat.ScanStructs()
-plat.ScanPhandles()
+plat.scan_dtb()
+plat.scan_tree()
+plat.setup_output(options.output)
+structs = plat.scan_structs()
+plat.scan_phandles()
 
 for cmd in args[0].split(','):
     if cmd == 'struct':
-        plat.GenerateStructs(structs)
+        plat.generate_structs(structs)
     elif cmd == 'platdata':
-        plat.GenerateTables()
+        plat.generate_tables()
     else:
         raise ValueError("Unknown command '%s': (use: struct, platdata)" % cmd)