devicetree.py

#!/usr/bin/env python3
#
# Copyright (c) 2017 Intel Corporation
#
# SPDX-License-Identifier: Apache-2.0
#

# vim: ai:ts=4:sw=4

import sys
import pprint
import re

def read_until(line, fd, end):
    out = [line]
    while True:
        idx = line.find(end)
        if idx < 0:
            line = clean_line(fd.readline(), fd)
            out.append(line)
        else:
            out.append(line[idx + len(end):])
            return out

def remove_comment(line, fd):
    out = []
    while True:
        idx = line.find('/*')
        if idx < 0:
            idx = line.find('//')
            if idx < 0:
                out.append(line)
            else:
                out.append(line[:idx])
            return ' '.join(out)

        out.append(line[:idx])
        line = read_until(line[idx:], fd, '*/')[-1]

def clean_line(line, fd):
    return remove_comment(line, fd).strip()

def parse_node_name(line):
    line = line[:-1]

    if '@' in line:
        line, addr = line.split('@')
    else:
        addr = None

    if ':' in line:
        if len(line.split(':')) == 3:
            alt_label, label, name = line.split(':')
        else:
            label, name = line.split(':')
            alt_label = None
    else:
        name = line
        label = None
        alt_label = None

    if addr is None:
        return label, name.strip(), None, None, None

    if alt_label is None:
        return label, name.strip(), addr, int(addr, 16), None

    return label, name.strip(), addr, int(addr, 16), alt_label

def parse_values_internal(value, start, end, separator):
    out = []

    inside = False
    accum = []
    for ch in value:
        if not inside:
            if ch == start:
                inside = True
                accum = []
        else:
            if ch == end:
                inside = False
                out.append(''.join(accum))
                accum = []
            else:
                accum.append(ch)

    if separator == ' ':
        out = [v.split() for v in out]

    if len(out) == 1:
        return parse_value(out[0])

    return [parse_value(v) for v in out]

def parse_values(value, start, end, separator):
    out = parse_values_internal(value, start, end, separator)
    if isinstance(out, list) and \
       all(isinstance(v, str) and len(v) == 1 and not v.isalpha() for v in out):
        return bytearray(out)

    return out

def parse_value(value):
    if value == '':
        return value

    if isinstance(value, list):
        out = [parse_value(v) for v in value]
        return out[0] if len(out) == 1 else out

    if value[0] == '<':
        return parse_values(value, '<', '>', ' ')
    if value[0] == '"':
        return parse_values(value, '"', '"', ',')
    if value[0] == '[':
        return parse_values(value, '[', ']', ' ')

    if value[0] == '&':
        return {'ref': value[1:]}

    if value[0].isdigit():
        if value.startswith("0x"):
            return int(value, 16)
        if value[0] == '0':
            return int(value, 8)
        # Match alpha numeric values
        if re.match("\w", value):
            return value
        return int(value, 10)

    return value

def parse_property(property, fd):
    if '=' in property:
        key, value = property.split('=', 1)
        value = ' '.join(read_until(value, fd, ';')).strip()
        if not value.endswith(';'):
            raise SyntaxError("parse_property: missing semicolon: %s" % value)
        return key.strip(), parse_value(value[:-1])

    property = property.strip()
    if not property.endswith(';'):
        raise SyntaxError("parse_property: missing semicolon: %s" % property)

    return property[:-1].strip(), True

def build_node_name(name, addr):
    if addr is None:
        return name
    elif isinstance(addr, int):
        return '%s@%x' % (name, addr)

    return '%s@%s' % (name, addr.strip())

def parse_node(line, fd):
    label, name, addr, numeric_addr, alt_label = parse_node_name(line)

    node = {
        'label': label,
        'type': type,
        'addr': numeric_addr,
        'children': {},
        'props': {},
        'name': build_node_name(name, addr)
    }
    if alt_label:
        node['alt_name'] = alt_label

    while True:
        line = fd.readline()
        if not line:
            raise SyntaxError("parse_node: Missing } while parsing node")

        line = clean_line(line, fd)
        if not line:
            continue

        if line == "};":
            break

        if line.endswith('{'):
            new_node = parse_node(line, fd)
            node['children'][new_node['name']] = new_node
        else:
            key, value = parse_property(line, fd)
            node['props'][key] = value

    return node

def parse_file(fd, ignore_dts_version=False):
    nodes = {}
    has_v1_tag = False
    while True:
        line = fd.readline()
        if not line:
            break

        line = clean_line(line, fd)
        if not line:
            continue

        if line.startswith('/include/ '):
            _, filename = line.split()
            with open(filename.strip()[1:-1], "r") as new_fd:
                nodes.update(parse_file(new_fd, True))
        elif line == '/dts-v1/;':
            has_v1_tag = True
        elif line.startswith('/memreserve/ ') and line.endswith(';'):
            _, start, end = line.split()
            start = int(start, 16)
            end = int(end[:-1], 16)
            label = "reserved_memory_0x%x_0x%x" % (start, end)
            nodes[label] = {
                'type': 'memory',
                'reg': [start, end],
                'label': label,
                'addr': start,
                'name': '<memreserve>'
            }
        elif line.endswith('{'):
            if not has_v1_tag and not ignore_dts_version:
                raise SyntaxError("parse_file: Missing /dts-v1/ tag")

            new_node = parse_node(line, fd)
            nodes[new_node['name']] = new_node
        else:
            raise SyntaxError("parse_file: Couldn't understand the line: %s" % line)
    return nodes

def dump_refs(name, value, indent=0):
    spaces = '  ' * indent

    out = []
    if isinstance(value, dict) and 'ref' in value:
        out.append('%s\"%s\" -> \"%s\";' % (spaces, name, value['ref']))
    elif isinstance(value, list):
        for elem in value:
            out.extend(dump_refs(name, elem, indent))

    return out

def dump_all_refs(name, props, indent=0):
    out = []
    for value in props.values():
        out.extend(dump_refs(name, value, indent))
    return out

def next_subgraph(count=[0]):
    count[0] += 1
    return 'subgraph cluster_%d' % count[0]

def get_dot_node_name(node):
    name = node['name']
    return name[1:] if name[0] == '&' else name

def dump_to_dot(nodes, indent=0, start_string='digraph devicetree', name=None):
    spaces = '  ' * indent

    print("%s%s {" % (spaces, start_string))

    if name is not None:
        print("%slabel = \"%s\";" % (spaces, name))
        print("%s\"%s\";" % (spaces, name))

    ref_list = []
    for node in nodes.values():
        if node['children']:
            refs = dump_to_dot(node['children'], indent + 1, next_subgraph(),
                               get_dot_node_name(node))
            ref_list.extend(refs)
        else:
            print("%s\"%s\";" % (spaces, get_dot_node_name(node)))

    for node in nodes.values():
        refs = dump_all_refs(get_dot_node_name(node), node['props'], indent)
        ref_list.extend(refs)

    if start_string.startswith("digraph"):
        print("%s%s" % (spaces, '\n'.join(ref_list)))

    print("%s}" % spaces)

    return ref_list

def main(args):
    if len(args) == 1:
        print('Usage: %s filename.dts' % args[0])
        return 1

    if '--dot' in args:
        formatter = dump_to_dot
        args.remove('--dot')
    else:
        formatter = lambda nodes: pprint.pprint(nodes, indent=2)

    with open(args[1], "r") as fd:
        formatter(parse_file(fd))

    return 0

if __name__ == '__main__':
    sys.exit(main(sys.argv))