| #!/usr/bin/python | |
| # SPDX-License-Identifier: GPL-2.0+ | |
| # | |
| # Copyright (C) 2017 Google, Inc | |
| # Written by Simon Glass <sjg@chromium.org> | |
| # | |
| """Device tree to platform data class | |
| This supports converting device tree data to C structures definitions and | |
| static data. | |
| """ | |
| import collections | |
| import copy | |
| import sys | |
| import fdt | |
| import fdt_util | |
| import tools | |
| # 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', | |
| 'u-boot,dm-pre-reloc', | |
| 'u-boot,dm-tpl', | |
| 'u-boot,dm-spl', | |
| ] | |
| # C type declarations for the tyues we support | |
| TYPE_NAMES = { | |
| fdt.TYPE_INT: 'fdt32_t', | |
| fdt.TYPE_BYTE: 'unsigned char', | |
| fdt.TYPE_STRING: 'const char *', | |
| fdt.TYPE_BOOL: 'bool', | |
| fdt.TYPE_INT64: 'fdt64_t', | |
| } | |
| STRUCT_PREFIX = 'dtd_' | |
| VAL_PREFIX = 'dtv_' | |
| # This holds information about a property which includes phandles. | |
| # | |
| # max_args: integer: Maximum number or arguments that any phandle uses (int). | |
| # args: Number of args for each phandle in the property. The total number of | |
| # phandles is len(args). This is a list of integers. | |
| PhandleInfo = collections.namedtuple('PhandleInfo', ['max_args', 'args']) | |
| def conv_name_to_c(name): | |
| """Convert a device-tree name to a C identifier | |
| This uses multiple replace() calls instead of re.sub() since it is faster | |
| (400ms for 1m calls versus 1000ms for the 're' version). | |
| Args: | |
| name: Name to convert | |
| Return: | |
| String containing the C version of this name | |
| """ | |
| new = name.replace('@', '_at_') | |
| 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) | |
| def get_value(ftype, 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 ftype == fdt.TYPE_INT: | |
| return '%#x' % fdt_util.fdt32_to_cpu(value) | |
| elif ftype == fdt.TYPE_BYTE: | |
| return '%#x' % tools.ToByte(value[0]) | |
| elif ftype == fdt.TYPE_STRING: | |
| return '"%s"' % value | |
| elif ftype == fdt.TYPE_BOOL: | |
| return 'true' | |
| elif ftype == fdt.TYPE_INT64: | |
| return '%#x' % value | |
| def get_compat_name(node): | |
| """Get a node's first compatible string as a C identifier | |
| Args: | |
| node: Node object to check | |
| Return: | |
| Tuple: | |
| C identifier for the first compatible string | |
| List of C identifiers for all the other compatible strings | |
| (possibly empty) | |
| """ | |
| compat = node.props['compatible'].value | |
| aliases = [] | |
| 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] | |
| 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- | |
| 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 | |
| _include_disabled: true to include nodes marked status = "disabled" | |
| _outfile: The current output file (sys.stdout or a real file) | |
| _lines: Stashed list of output lines for outputting in the future | |
| """ | |
| def __init__(self, dtb_fname, include_disabled): | |
| self._fdt = None | |
| self._dtb_fname = dtb_fname | |
| self._valid_nodes = None | |
| self._include_disabled = include_disabled | |
| self._outfile = None | |
| self._lines = [] | |
| self._aliases = {} | |
| def setup_output(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, line): | |
| """Output a string to the output file | |
| Args: | |
| line: String to output | |
| """ | |
| self._outfile.write(line) | |
| def buf(self, line): | |
| """Buffer up a string to send later | |
| Args: | |
| line: String to add to our 'buffer' list | |
| """ | |
| self._lines.append(line) | |
| def get_buf(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 out_header(self): | |
| """Output a message indicating that this is an auto-generated file""" | |
| self.out('''/* | |
| * DO NOT MODIFY | |
| * | |
| * This file was generated by dtoc from a .dtb (device tree binary) file. | |
| */ | |
| ''') | |
| def get_phandle_argc(self, prop, node_name): | |
| """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: | |
| Number of argument cells is this is a phandle, else None | |
| """ | |
| if prop.name in ['clocks']: | |
| if not isinstance(prop.value, list): | |
| prop.value = [prop.value] | |
| val = prop.value | |
| i = 0 | |
| max_args = 0 | |
| args = [] | |
| while i < len(val): | |
| phandle = fdt_util.fdt32_to_cpu(val[i]) | |
| # If we get to the end of the list, stop. This can happen | |
| # since some nodes have more phandles in the list than others, | |
| # but we allocate enough space for the largest list. So those | |
| # nodes with shorter lists end up with zeroes at the end. | |
| if not phandle: | |
| break | |
| target = self._fdt.phandle_to_node.get(phandle) | |
| if not target: | |
| raise ValueError("Cannot parse '%s' in node '%s'" % | |
| (prop.name, node_name)) | |
| prop_name = '#clock-cells' | |
| cells = target.props.get(prop_name) | |
| if not cells: | |
| raise ValueError("Node '%s' has no '%s' property" % | |
| (target.name, prop_name)) | |
| num_args = fdt_util.fdt32_to_cpu(cells.value) | |
| max_args = max(max_args, num_args) | |
| args.append(num_args) | |
| i += 1 + num_args | |
| return PhandleInfo(max_args, args) | |
| return None | |
| def scan_dtb(self): | |
| """Scan the device tree to obtain a tree of nodes 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.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. | |
| Args: | |
| root: Root node for scan | |
| """ | |
| for node in root.subnodes: | |
| if 'compatible' in node.props: | |
| status = node.props.get('status') | |
| if (not self._include_disabled and not status or | |
| status.value != 'disabled'): | |
| self._valid_nodes.append(node) | |
| # recurse to handle any subnodes | |
| self.scan_node(node) | |
| def scan_tree(self): | |
| """Scan the device tree for useful information | |
| This fills in the following properties: | |
| _valid_nodes: A list of nodes we wish to consider include in the | |
| platform data | |
| """ | |
| self._valid_nodes = [] | |
| return self.scan_node(self._fdt.GetRoot()) | |
| @staticmethod | |
| def get_num_cells(node): | |
| """Get the number of cells in addresses and sizes for this node | |
| Args: | |
| node: Node to check | |
| Returns: | |
| Tuple: | |
| Number of address cells for this node | |
| Number of size cells for this node | |
| """ | |
| parent = node.parent | |
| na, ns = 2, 2 | |
| if parent: | |
| na_prop = parent.props.get('#address-cells') | |
| ns_prop = parent.props.get('#size-cells') | |
| if na_prop: | |
| na = fdt_util.fdt32_to_cpu(na_prop.value) | |
| if ns_prop: | |
| ns = fdt_util.fdt32_to_cpu(ns_prop.value) | |
| return na, ns | |
| def scan_reg_sizes(self): | |
| """Scan for 64-bit 'reg' properties and update the values | |
| This finds 'reg' properties with 64-bit data and converts the value to | |
| an array of 64-values. This allows it to be output in a way that the | |
| C code can read. | |
| """ | |
| for node in self._valid_nodes: | |
| reg = node.props.get('reg') | |
| if not reg: | |
| continue | |
| na, ns = self.get_num_cells(node) | |
| total = na + ns | |
| if reg.type != fdt.TYPE_INT: | |
| raise ValueError("Node '%s' reg property is not an int" % | |
| node.name) | |
| if len(reg.value) % total: | |
| raise ValueError("Node '%s' reg property has %d cells " | |
| 'which is not a multiple of na + ns = %d + %d)' % | |
| (node.name, len(reg.value), na, ns)) | |
| reg.na = na | |
| reg.ns = ns | |
| if na != 1 or ns != 1: | |
| reg.type = fdt.TYPE_INT64 | |
| i = 0 | |
| new_value = [] | |
| val = reg.value | |
| if not isinstance(val, list): | |
| val = [val] | |
| while i < len(val): | |
| addr = fdt_util.fdt_cells_to_cpu(val[i:], reg.na) | |
| i += na | |
| size = fdt_util.fdt_cells_to_cpu(val[i:], reg.ns) | |
| i += ns | |
| new_value += [addr, size] | |
| reg.value = new_value | |
| 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 | |
| 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. | |
| Once the widest property is determined, all other properties are | |
| updated to match that width. | |
| """ | |
| structs = {} | |
| for node in self._valid_nodes: | |
| node_name, _ = get_compat_name(node) | |
| fields = {} | |
| # Get a list of all the valid properties in this node. | |
| for name, prop in node.props.items(): | |
| if name not in PROP_IGNORE_LIST and name[0] != '#': | |
| fields[name] = copy.deepcopy(prop) | |
| # If we've seen this node_name before, update the existing struct. | |
| if node_name in structs: | |
| struct = structs[node_name] | |
| for name, prop in fields.items(): | |
| oldprop = struct.get(name) | |
| if oldprop: | |
| oldprop.Widen(prop) | |
| else: | |
| struct[name] = prop | |
| # Otherwise store this as a new struct. | |
| else: | |
| structs[node_name] = fields | |
| upto = 0 | |
| for node in self._valid_nodes: | |
| node_name, _ = 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 = get_compat_name(node) | |
| for alias in aliases: | |
| self._aliases[alias] = struct_name | |
| return structs | |
| def scan_phandles(self): | |
| """Figure out what phandles each node uses | |
| We need to be careful when outputing nodes that use phandles since | |
| they must come after the declaration of the phandles in the C file. | |
| Otherwise we get a compiler error since the phandle struct is not yet | |
| declared. | |
| This function adds to each node a list of phandle nodes that the node | |
| depends on. This allows us to output things in the right order. | |
| """ | |
| for node in self._valid_nodes: | |
| node.phandles = set() | |
| for pname, prop in node.props.items(): | |
| if pname in PROP_IGNORE_LIST or pname[0] == '#': | |
| continue | |
| info = self.get_phandle_argc(prop, node.name) | |
| if info: | |
| # Process the list as pairs of (phandle, id) | |
| pos = 0 | |
| for args in info.args: | |
| phandle_cell = prop.value[pos] | |
| phandle = fdt_util.fdt32_to_cpu(phandle_cell) | |
| target_node = self._fdt.phandle_to_node[phandle] | |
| node.phandles.add(target_node) | |
| pos += 1 + args | |
| 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_header() | |
| self.out('#include <stdbool.h>\n') | |
| self.out('#include <linux/libfdt.h>\n') | |
| # 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] | |
| info = self.get_phandle_argc(prop, structs[name]) | |
| if info: | |
| # For phandles, include a reference to the target | |
| struct_name = 'struct phandle_%d_arg' % info.max_args | |
| self.out('\t%s%s[%d]' % (tab_to(2, struct_name), | |
| conv_name_to_c(prop.name), | |
| len(info.args))) | |
| else: | |
| ptype = TYPE_NAMES[prop.type] | |
| 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.items(): | |
| if alias not in sorted(structs): | |
| self.out('#define %s%s %s%s\n'% (STRUCT_PREFIX, alias, | |
| STRUCT_PREFIX, struct_name)) | |
| def output_node(self, node): | |
| """Output the C code for a node | |
| Args: | |
| node: node to output | |
| """ | |
| struct_name, _ = get_compat_name(node) | |
| var_name = conv_name_to_c(node.name) | |
| self.buf('static const struct %s%s %s%s = {\n' % | |
| (STRUCT_PREFIX, struct_name, VAL_PREFIX, var_name)) | |
| for pname in sorted(node.props): | |
| prop = node.props[pname] | |
| if pname in PROP_IGNORE_LIST or pname[0] == '#': | |
| continue | |
| member_name = conv_name_to_c(prop.name) | |
| self.buf('\t%s= ' % tab_to(3, '.' + member_name)) | |
| # Special handling for lists | |
| if isinstance(prop.value, list): | |
| self.buf('{') | |
| vals = [] | |
| # For phandles, output a reference to the platform data | |
| # of the target node. | |
| info = self.get_phandle_argc(prop, node.name) | |
| if info: | |
| # Process the list as pairs of (phandle, id) | |
| pos = 0 | |
| for args in info.args: | |
| phandle_cell = prop.value[pos] | |
| phandle = fdt_util.fdt32_to_cpu(phandle_cell) | |
| target_node = self._fdt.phandle_to_node[phandle] | |
| name = conv_name_to_c(target_node.name) | |
| arg_values = [] | |
| for i in range(args): | |
| arg_values.append(str(fdt_util.fdt32_to_cpu(prop.value[pos + 1 + i]))) | |
| pos += 1 + args | |
| vals.append('\t{&%s%s, {%s}}' % (VAL_PREFIX, name, | |
| ', '.join(arg_values))) | |
| for val in vals: | |
| self.buf('\n\t\t%s,' % val) | |
| else: | |
| for val in prop.value: | |
| vals.append(get_value(prop.type, val)) | |
| # Put 8 values per line to avoid very long lines. | |
| for i in range(0, len(vals), 8): | |
| if i: | |
| self.buf(',\n\t\t') | |
| self.buf(', '.join(vals[i:i + 8])) | |
| self.buf('}') | |
| else: | |
| self.buf(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.out(''.join(self.get_buf())) | |
| def generate_tables(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. Where a node has | |
| multiple compatible strings, a #define is used to make them equivalent. | |
| See the documentation in doc/driver-model/of-plat.txt for more | |
| information. | |
| """ | |
| self.out_header() | |
| 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 | |
| while nodes_to_output: | |
| node = nodes_to_output[0] | |
| # Output all the node's dependencies first | |
| for req_node in node.phandles: | |
| if req_node in nodes_to_output: | |
| self.output_node(req_node) | |
| nodes_to_output.remove(req_node) | |
| self.output_node(node) | |
| nodes_to_output.remove(node) | |
| def run_steps(args, dtb_file, include_disabled, output): | |
| """Run all the steps of the dtoc tool | |
| Args: | |
| args: List of non-option arguments provided to the problem | |
| dtb_file: Filename of dtb file to process | |
| include_disabled: True to include disabled nodes | |
| output: Name of output file | |
| """ | |
| if not args: | |
| raise ValueError('Please specify a command: struct, platdata') | |
| plat = DtbPlatdata(dtb_file, include_disabled) | |
| plat.scan_dtb() | |
| plat.scan_tree() | |
| plat.scan_reg_sizes() | |
| plat.setup_output(output) | |
| structs = plat.scan_structs() | |
| plat.scan_phandles() | |
| for cmd in args[0].split(','): | |
| if cmd == 'struct': | |
| plat.generate_structs(structs) | |
| elif cmd == 'platdata': | |
| plat.generate_tables() | |
| else: | |
| raise ValueError("Unknown command '%s': (use: struct, platdata)" % | |
| cmd) |