#!/usr/bin/python # SPDX-License-Identifier: GPL-2.0+ # # Copyright (C) 2017 Google, Inc # Written by Simon Glass # """Device tree to platform data class This supports converting device tree data to C structures definitions and static data. See doc/driver-model/of-plat.rst for more informaiton """ import collections import copy from enum import IntEnum import os import re import sys from dtoc import fdt from dtoc import fdt_util # 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 types 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_' class Ftype(IntEnum): SOURCE, HEADER = range(2) # This holds information about each type of output file dtoc can create # type: Type of file (Ftype) # fname: Filename excluding directory, e.g. 'dt-platdata.c' OutputFile = collections.namedtuple('OutputFile', ['ftype', 'fname']) # 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']) # Holds a single phandle link, allowing a C struct value to be assigned to point # to a device # # var_node: C variable to assign (e.g. 'dtv_mmc.clocks[0].node') # dev_name: Name of device to assign to (e.g. 'clock') PhandleLink = collections.namedtuple('PhandleLink', ['var_node', 'dev_name']) class Driver: """Information about a driver in U-Boot Attributes: name: Name of driver. For U_BOOT_DRIVER(x) this is 'x' """ def __init__(self, name): self.name = name def __eq__(self, other): return self.name == other.name def __repr__(self): return "Driver(name='%s')" % self.name 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 (str): Name to convert Return: str: 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 (int): Tab stop to obtain (0 = column 0, 1 = column 8, etc.) line (str): Line of text to append to Returns: str: 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: ftype (fdt.Type): Data type (fdt_util) value (bytes): Data value, as a string of bytes Returns: str: String representation of the value """ if ftype == fdt.Type.INT: val = '%#x' % fdt_util.fdt32_to_cpu(value) elif ftype == fdt.Type.BYTE: char = value[0] val = '%#x' % (ord(char) if isinstance(char, str) else char) elif ftype == fdt.Type.STRING: # Handle evil ACPI backslashes by adding another backslash before them. # So "\\_SB.GPO0" in the device tree effectively stays like that in C val = '"%s"' % value.replace('\\', '\\\\') elif ftype == fdt.Type.BOOL: val = 'true' else: # ftype == fdt.Type.INT64: val = '%#x' % value return val def get_compat_name(node): """Get the node's list of compatible string as a C identifiers Args: node (fdt.Node): Node object to check Return: list of str: List of C identifiers for all the compatible strings """ compat = node.props['compatible'].value if not isinstance(compat, list): compat = [compat] return [conv_name_to_c(c) for c in compat] 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. The list is ordered by conv_name_to_c(node.name) _include_disabled: true to include nodes marked status = "disabled" _outfile: The current output file (sys.stdout or a real file) _warning_disabled: true to disable warnings about driver names not found _lines: Stashed list of output lines for outputting in the future _drivers: Dict of valid driver names found in drivers/ key: Driver name value: Driver for that driver _driver_aliases: Dict that holds aliases for driver names key: Driver alias declared with U_BOOT_DRIVER_ALIAS(driver_alias, driver_name) value: Driver name declared with U_BOOT_DRIVER(driver_name) _drivers_additional: List of additional drivers to use during scanning _dirname: Directory to hold output files, or None for none (all files go to stdout) """ def __init__(self, dtb_fname, include_disabled, warning_disabled, drivers_additional=None): self._fdt = None self._dtb_fname = dtb_fname self._valid_nodes = None self._include_disabled = include_disabled self._outfile = None self._warning_disabled = warning_disabled self._lines = [] self._drivers = {} self._driver_aliases = {} self._drivers_additional = drivers_additional or [] self._dirnames = [None] * len(Ftype) def get_normalized_compat_name(self, node): """Get a node's normalized compat name Returns a valid driver name by retrieving node's list of compatible string as a C identifier and performing a check against _drivers and a lookup in driver_aliases printing a warning in case of failure. Args: node (Node): Node object to check Return: Tuple: Driver name associated with the first compatible string List of C identifiers for all the other compatible strings (possibly empty) In case of no match found, the return will be the same as get_compat_name() """ compat_list_c = get_compat_name(node) for compat_c in compat_list_c: if not compat_c in self._drivers.keys(): compat_c = self._driver_aliases.get(compat_c) if not compat_c: continue aliases_c = compat_list_c if compat_c in aliases_c: aliases_c.remove(compat_c) return compat_c, aliases_c if not self._warning_disabled: print('WARNING: the driver %s was not found in the driver list' % (compat_list_c[0])) return compat_list_c[0], compat_list_c[1:] def setup_output_dirs(self, output_dirs): """Set up the output directories This should be done before setup_output() is called Args: output_dirs (tuple of str): Directory to use for C output files. Use None to write files relative current directory Directory to use for H output files. Defaults to the C output dir """ def process_dir(ftype, dirname): if dirname: os.makedirs(dirname, exist_ok=True) self._dirnames[ftype] = dirname if output_dirs: c_dirname = output_dirs[0] h_dirname = output_dirs[1] if len(output_dirs) > 1 else c_dirname process_dir(Ftype.SOURCE, c_dirname) process_dir(Ftype.HEADER, h_dirname) def setup_output(self, ftype, fname): """Set up the output destination Once this is done, future calls to self.out() will output to this file. The file used is as follows: self._dirnames[ftype] is None: output to fname, or stdout if None self._dirnames[ftype] is not None: output to fname in that directory Calling this function multiple times will close the old file and open the new one. If they are the same file, nothing happens and output will continue to the same file. Args: ftype (str): Type of file to create ('c' or 'h') fname (str): Filename to send output to. If there is a directory in self._dirnames for this file type, it will be put in that directory """ dirname = self._dirnames[ftype] if dirname: pathname = os.path.join(dirname, fname) if self._outfile: self._outfile.close() self._outfile = open(pathname, 'w') elif fname: if not self._outfile: self._outfile = open(fname, 'w') else: self._outfile = sys.stdout def finish_output(self): """Finish outputing to a file This closes the output file, if one is in use """ if self._outfile != sys.stdout: self._outfile.close() def out(self, line): """Output a string to the output file Args: line (str): String to output """ self._outfile.write(line) def buf(self, line): """Buffer up a string to send later Args: line (str): 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: list(str): 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 (fdt.Prop): Prop object to check node_name (str): Node name, only used for raising an error Returns: int or None: Number of argument cells is this is a phandle, else None Raises: ValueError: if the phandle cannot be parsed or the required property is not present """ if prop.name in ['clocks', 'cd-gpios']: 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)) cells = None for prop_name in ['#clock-cells', '#gpio-cells']: cells = target.props.get(prop_name) if cells: break if not cells: raise ValueError("Node '%s' has no cells property" % (target.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_driver(self, fname): """Scan a driver file to build a list of driver names and aliases This procedure will populate self._drivers and self._driver_aliases Args fname: Driver filename to scan """ with open(fname, encoding='utf-8') as inf: try: buff = inf.read() except UnicodeDecodeError: # This seems to happen on older Python versions print("Skipping file '%s' due to unicode error" % fname) return # The following re will search for driver names declared as # U_BOOT_DRIVER(driver_name) drivers = re.findall(r'U_BOOT_DRIVER\((.*)\)', buff) for driver in drivers: self._drivers[driver] = Driver(driver) # The following re will search for driver aliases declared as # U_BOOT_DRIVER_ALIAS(alias, driver_name) driver_aliases = re.findall( r'U_BOOT_DRIVER_ALIAS\(\s*(\w+)\s*,\s*(\w+)\s*\)', buff) for alias in driver_aliases: # pragma: no cover if len(alias) != 2: continue self._driver_aliases[alias[1]] = alias[0] def scan_drivers(self): """Scan the driver folders to build a list of driver names and aliases This procedure will populate self._drivers and self._driver_aliases """ basedir = sys.argv[0].replace('tools/dtoc/dtoc', '') if basedir == '': basedir = './' for (dirpath, _, filenames) in os.walk(basedir): for fname in filenames: if not fname.endswith('.c'): continue self.scan_driver(dirpath + '/' + fname) for fname in self._drivers_additional: if not isinstance(fname, str) or len(fname) == 0: continue if fname[0] == '/': self.scan_driver(fname) else: self.scan_driver(basedir + '/' + fname) 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, valid_nodes): """Scan a node and subnodes to build a tree of node and phandle info This adds each node to self._valid_nodes. Args: root (Node): Root node for scan valid_nodes (list of Node): List of Node objects to add to """ 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'): valid_nodes.append(node) # recurse to handle any subnodes self.scan_node(node, valid_nodes) 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 """ valid_nodes = [] self.scan_node(self._fdt.GetRoot(), valid_nodes) self._valid_nodes = sorted(valid_nodes, key=lambda x: conv_name_to_c(x.name)) for idx, node in enumerate(self._valid_nodes): node.idx = idx @staticmethod def get_num_cells(node): """Get the number of cells in addresses and sizes for this node Args: node (fdt.None): Node to check Returns: Tuple: Number of address cells for this node Number of size cells for this node """ parent = node.parent num_addr, num_size = 2, 2 if parent: addr_prop = parent.props.get('#address-cells') size_prop = parent.props.get('#size-cells') if addr_prop: num_addr = fdt_util.fdt32_to_cpu(addr_prop.value) if size_prop: num_size = fdt_util.fdt32_to_cpu(size_prop.value) return num_addr, num_size 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 num_addr, num_size = self.get_num_cells(node) total = num_addr + num_size 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), num_addr, num_size)) reg.num_addr = num_addr reg.num_size = num_size if num_addr != 1 or num_size != 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.num_addr) i += num_addr size = fdt_util.fdt_cells_to_cpu(val[i:], reg.num_size) i += num_size 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. Returns: dict of dict: dict containing structures: key (str): Node name, as a C identifier value: dict containing structure fields: key (str): Field name value: Prop object with field information """ structs = collections.OrderedDict() for node in self._valid_nodes: node_name, _ = self.get_normalized_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 for node in self._valid_nodes: node_name, _ = self.get_normalized_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]) 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 doc/driver-model/of-plat.rst for more information. Args: structs (dict): dict containing structures: key (str): Node name, as a C identifier value: dict containing structure fields: key (str): Field name value: Prop object with field information """ self.out_header() self.out('#include \n') self.out('#include \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') def _output_list(self, node, prop): """Output the C code for a devicetree property that holds a list Args: node (fdt.Node): Node to output prop (fdt.Prop): Prop to output """ 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] 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{%d, {%s}}' % (target_node.idx, ', '.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('}') def _declare_device(self, var_name, struct_name, node_parent): """Add a device declaration to the output This declares a U_BOOT_DRVINFO() for the device being processed Args: var_name (str): C name for the node struct_name (str): Name for the dt struct associated with the node node_parent (Node): Parent of the node (or None if none) """ self.buf('U_BOOT_DRVINFO(%s) = {\n' % var_name) self.buf('\t.name\t\t= "%s",\n' % struct_name) self.buf('\t.plat\t= &%s%s,\n' % (VAL_PREFIX, var_name)) self.buf('\t.plat_size\t= sizeof(%s%s),\n' % (VAL_PREFIX, var_name)) idx = -1 if node_parent and node_parent in self._valid_nodes: idx = node_parent.idx self.buf('\t.parent_idx\t= %d,\n' % idx) self.buf('};\n') self.buf('\n') def _output_prop(self, node, prop): """Output a line containing the value of a struct member Args: node (Node): Node being output prop (Prop): Prop object to output """ if prop.name in PROP_IGNORE_LIST or prop.name[0] == '#': return 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._output_list(node, prop) else: self.buf(get_value(prop.type, prop.value)) self.buf(',\n') def _output_values(self, var_name, struct_name, node): """Output the definition of a device's struct values Args: var_name (str): C name for the node struct_name (str): Name for the dt struct associated with the node node (Node): Node being output """ self.buf('static struct %s%s %s%s = {\n' % (STRUCT_PREFIX, struct_name, VAL_PREFIX, var_name)) for pname in sorted(node.props): self._output_prop(node, node.props[pname]) self.buf('};\n') def output_node(self, node): """Output the C code for a node Args: node (fdt.Node): node to output """ struct_name, _ = self.get_normalized_compat_name(node) var_name = conv_name_to_c(node.name) self.buf('/* Node %s index %d */\n' % (node.path, node.idx)) self._output_values(var_name, struct_name, node) self._declare_device(var_name, struct_name, node.parent) 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_DRVINFO() 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.rst for more information. """ self.out_header() self.out('/* Allow use of U_BOOT_DRVINFO() in this file */\n') self.out('#define DT_PLATDATA_C\n') self.out('\n') self.out('#include \n') self.out('#include \n') self.out('#include \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) # Define dm_populate_phandle_data() which will add the linking between # nodes using DM_GET_DEVICE # dtv_dmc_at_xxx.clocks[0].node = DM_GET_DEVICE(clock_controller_at_xxx) self.buf('void dm_populate_phandle_data(void) {\n') self.buf('}\n') self.out(''.join(self.get_buf())) # Types of output file we understand # key: Command used to generate this file # value: OutputFile for this command OUTPUT_FILES = { 'struct': OutputFile(Ftype.HEADER, 'dt-structs-gen.h'), 'platdata': OutputFile(Ftype.SOURCE, 'dt-platdata.c'), } def run_steps(args, dtb_file, include_disabled, output, output_dirs, warning_disabled=False, drivers_additional=None): """Run all the steps of the dtoc tool Args: args (list): List of non-option arguments provided to the problem dtb_file (str): Filename of dtb file to process include_disabled (bool): True to include disabled nodes output (str): Name of output file (None for stdout) output_dirs (tuple of str): Directory to put C output files Directory to put H output files warning_disabled (bool): True to avoid showing warnings about missing drivers drivers_additional (list): List of additional drivers to use during scanning Raises: ValueError: if args has no command, or an unknown command """ if not args: raise ValueError('Please specify a command: struct, platdata, all') if output and output_dirs and any(output_dirs): raise ValueError('Must specify either output or output_dirs, not both') plat = DtbPlatdata(dtb_file, include_disabled, warning_disabled, drivers_additional) plat.scan_drivers() plat.scan_dtb() plat.scan_tree() plat.scan_reg_sizes() plat.setup_output_dirs(output_dirs) structs = plat.scan_structs() plat.scan_phandles() cmds = args[0].split(',') if 'all' in cmds: cmds = sorted(OUTPUT_FILES.keys()) for cmd in cmds: outfile = OUTPUT_FILES.get(cmd) if not outfile: raise ValueError("Unknown command '%s': (use: %s)" % (cmd, ', '.join(sorted(OUTPUT_FILES.keys())))) plat.setup_output(outfile.ftype, outfile.fname if output_dirs else output) if cmd == 'struct': plat.generate_structs(structs) elif cmd == 'platdata': plat.generate_tables() plat.finish_output()