This tool can produce C struct definitions and C platform data tables. This is used to support the of-platdata feature.
Signed-off-by: Simon Glass sjg@chromium.org ---
Changes in v2: None
tools/dtoc/dtoc | 1 + tools/dtoc/dtoc.py | 365 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 366 insertions(+) create mode 120000 tools/dtoc/dtoc create mode 100755 tools/dtoc/dtoc.py
diff --git a/tools/dtoc/dtoc b/tools/dtoc/dtoc new file mode 120000 index 0000000..896ca44 --- /dev/null +++ b/tools/dtoc/dtoc @@ -0,0 +1 @@ +dtoc.py \ No newline at end of file diff --git a/tools/dtoc/dtoc.py b/tools/dtoc/dtoc.py new file mode 100755 index 0000000..6a2f6ef --- /dev/null +++ b/tools/dtoc/dtoc.py @@ -0,0 +1,365 @@ +#!/usr/bin/python +# +# Copyright (C) 2016 Google, Inc +# Written by Simon Glass sjg@chromium.org +# +# SPDX-License-Identifier: GPL-2.0+ +# + +from optparse import OptionError, OptionParser +import os +import sys + +import fdt_util + +# Bring in the patman libraries +our_path = os.path.dirname(os.path.realpath(__file__)) +sys.path.append(os.path.join(our_path, '../patman')) + +# Bring in either the normal fdt library (which relies on libfdt) or the +# fallback one (which uses fdtget and is slower). Both provide the same +# interfface for this file to use. +try: + from fdt import Fdt + import fdt + have_libfdt = True +except ImportError: + have_libfdt = False + from fdt_fallback import Fdt + import fdt_fallback as fdt + +import struct + +# When we see these properties we ignore them - i.e. do not create a structure member +PROP_IGNORE_LIST = [ + '#address-cells', + '#gpio-cells', + '#size-cells', + 'compatible', + 'linux,phandle', + "status", + 'phandle', +] + +# C type declarations for the tyues we support +TYPE_NAMES = { + fdt_util.TYPE_INT: 'fdt32_t', + fdt_util.TYPE_BYTE: 'unsigned char', + fdt_util.TYPE_STRING: 'const char *', + fdt_util.TYPE_BOOL: 'bool', +}; + +STRUCT_PREFIX = 'dtd_' +VAL_PREFIX = 'dtv_' + +def Conv_name_to_c(name): + """Convert a device-tree name to a C identifier + + Args: + name: Name to convert + Return: + String containing the C version of this name + """ + str = name.replace('@', '_at_') + 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: + """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- + constrained encvironments where the ~3KB code overhead of device tree + code is not affordable. + + Properties: + 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...) + _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) + """ + def __init__(self, dtb_fname, options): + self._dtb_fname = dtb_fname + self._valid_nodes = None + self._options = options + self._phandle_node = {} + self._outfile = None + self._lines = [] + + def SetupOutput(self, fname): + """Set up the output destination + + Once this is done, future calls to self.Out() will output to this + file. + + Args: + fname: Filename to send output to, or '-' for stdout + """ + if fname == '-': + self._outfile = sys.stdout + else: + self._outfile = open(fname, 'w') + + def Out(self, str): + """Output a string to the output file + + Args: + str: String to output + """ + self._outfile.write(str) + + def Buf(self, str): + """Buffer up a string to send later + + Args: + str: String to add to our 'buffer' list + """ + self._lines.append(str) + + def GetBuf(self): + """Get the contents of the output buffer, and clear it + + Returns: + The output buffer, which is then cleared for future use + """ + lines = self._lines + self._lines = [] + return lines + + def GetValue(self, type, value): + """Get a value as a C expression + + For integers this returns a byte-swapped (little-endian) hex string + For bytes this returns a hex string, e.g. 0x12 + For strings this returns a literal string enclosed in quotes + For booleans this return 'true' + + Args: + type: Data type (fdt_util) + value: Data value, as a string of bytes + """ + if type == fdt_util.TYPE_INT: + return '%#x' % fdt_util.fdt32_to_cpu(value) + elif type == fdt_util.TYPE_BYTE: + return '%#x' % ord(value[0]) + elif type == fdt_util.TYPE_STRING: + return '"%s"' % value + elif type == fdt_util.TYPE_BOOL: + return 'true' + + def GetCompatName(self, node): + """Get a node's first compatible string as a C identifier + + Args: + node: Node object to check + Return: + C identifier for the first compatible string + """ + compat = node.props['compatible'].value + if type(compat) == list: + compat = compat[0] + return Conv_name_to_c(compat) + + def ScanDtb(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 + device tree root node, and progress from there. + """ + self.fdt = Fdt(self._dtb_fname) + self.fdt.Scan() + + def ScanTree(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) + _valid_nodes: A list of nodes we wish to consider include in the + platform data + """ + node_list = [] + self._phandle_node = {} + for node in self.fdt.GetRoot().subnodes: + if 'compatible' in node.props: + status = node.props.get('status') + if (not 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 + + def IsPhandle(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 GenerateStructs(self): + """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') + + # Build a dict keyed by C struct name containing a dict of Prop + # object for each struct field (keyed by property name). Where the + # same struct appears multiple times, try to use the 'widest' + # property, i.e. the one with a type which can express all others. + structs = {} + for node in self._valid_nodes: + node_name = self.GetCompatName(node) + fields = {} + for name, prop in node.props.iteritems(): + if name not in PROP_IGNORE_LIST and name[0] != '#': + fields[name] = prop + if node_name in structs: + struct = structs[node_name] + for name, prop in fields.iteritems(): + oldprop = struct.get(name) + if oldprop: + struct[name].Widen(oldprop) + else: + struct[name] = prop + else: + structs[node_name] = fields + + # Output the struct definition + for name in sorted(structs): + self.Out('struct %s%s {\n' % (STRUCT_PREFIX, name)); + for pname in sorted(structs[name]): + prop = structs[name][pname] + if self.IsPhandle(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), + 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') + + def GenerateTables(self): + """Generate device defintions for the platform data + + This writes out C platform data initialisation data and + U_BOOT_DEVICE() declarations for each valid node. See the + documentation in README.of-plat 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') + node_txt_list = [] + for node in self._valid_nodes: + 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)) + for pname, prop in node.props.iteritems(): + 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)) + + # Special handling for lists + if type(prop.value) == list: + self.Buf('{') + vals = [] + # For phandles, output a reference to the platform data + # of the target node. + if self.IsPhandle(prop): + # Process the list as pairs of (phandle, id) + it = iter(prop.value) + for phandle_cell, id_cell in zip(it, 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)) + else: + for val in prop.value: + vals.append(self.GetValue(prop.type, val)) + self.Buf(', '.join(vals)) + self.Buf('}') + else: + self.Buf(self.GetValue(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('};\n') + self.Buf('\n') + + # Output phandle target nodes first, since they may be referenced + # by others + if 'phandle' in node.props: + self.Out(''.join(self.GetBuf())) + else: + node_txt_list.append(self.GetBuf()) + + # Output all the nodes which are not phandle targets themselves, but + # may reference them. This avoids the need for forward declarations. + for node_txt in node_txt_list: + self.Out(''.join(node_txt)) + + +if __name__ != "__main__": + pass + +parser = OptionParser() +parser.add_option('-d', '--dtb-file', action='store', + help='Specify the .dtb input file') +parser.add_option('--include-disabled', action='store_true', + help='Include disabled nodes') +parser.add_option('-o', '--output', action='store', default='-', + help='Select output filename') +(options, args) = parser.parse_args() + +if not args: + raise ValueError('Please specify a command: struct, platdata') + +plat = DtbPlatdata(options.dtb_file, options) +plat.ScanDtb() +plat.ScanTree() +plat.SetupOutput(options.output) + +for cmd in args[0].split(','): + if cmd == 'struct': + plat.GenerateStructs() + elif cmd == 'platdata': + plat.GenerateTables() + else: + raise ValueError("Unknown command '%s': (use: struct, platdata)" % cmd)