#!/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 from dtoc import src_scan from dtoc.src_scan import conv_name_to_c # 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-plat.c' # hdr_comment: Comment explaining the purpose of the file OutputFile = collections.namedtuple('OutputFile', ['ftype', 'fname', 'method', 'hdr_comment']) # 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']) 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 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: _scan: Scan object, for scanning and reporting on useful information from the U-Boot source code _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) _lines: Stashed list of output lines for outputting in the future _dirname: Directory to hold output files, or None for none (all files go to stdout) _struct_data (dict): OrderedDict of dtplat structures to output key (str): Node name, as a C identifier value: dict containing structure fields: key (str): Field name value: Prop object with field information _basedir (str): Base directory of source tree """ def __init__(self, scan, dtb_fname, include_disabled): self._scan = scan self._fdt = None self._dtb_fname = dtb_fname self._valid_nodes = None self._include_disabled = include_disabled self._outfile = None self._lines = [] self._dirnames = [None] * len(Ftype) self._struct_data = collections.OrderedDict() self._basedir = None 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, outfile): """Output a message indicating that this is an auto-generated file Args: outfile: OutputFile describing the file being generated """ self.out('''/* * DO NOT MODIFY * * %s. * This was generated by dtoc from a .dtb (device tree binary) file. */ ''' % outfile.hdr_comment) 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_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)) def prepare_nodes(self): """Add extra properties to the nodes we are using The following properties are added for use by dtoc: idx: Index number of this node (0=first, etc.) struct_name: Name of the struct dtd used by this node var_name: C name for this node child_devs: List of child devices for this node, each a None child_refs: Dict of references for each child: key: Position in child list (-1=head, 0=first, 1=second, ... n-1=last, n=head) seq: Sequence number of the device (unique within its uclass), or -1 not not known yet dev_ref: Reference to this device, e.g. 'DM_DEVICE_REF(serial)' driver: Driver record for this node, or None if not known uclass: Uclass record for this node, or None if not known uclass_seq: Position of this device within the uclass list (0=first, n-1=last) parent_seq: Position of this device within it siblings (0=first, n-1=last) parent_driver: Driver record of the node's parent, or None if none. We don't use node.parent.driver since node.parent may not be in the list of valid nodes """ for idx, node in enumerate(self._valid_nodes): node.idx = idx node.struct_name, _ = self._scan.get_normalized_compat_name(node) node.var_name = conv_name_to_c(node.name) node.child_devs = [] node.child_refs = {} node.seq = -1 node.dev_ref = None node.driver = None node.uclass = None node.uclass_seq = None node.parent_seq = None node.parent_driver = None @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. The results are written to self._struct_data """ structs = self._struct_data for node in self._valid_nodes: 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 struct_name before, update the existing struct if node.struct_name in structs: struct = structs[node.struct_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.struct_name] = fields for node in self._valid_nodes: struct = structs[node.struct_name] for name, prop in node.props.items(): if name not in PROP_IGNORE_LIST and name[0] != '#': prop.Widen(struct[name]) 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): """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. """ structs = self._struct_data 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, node): """Add a device declaration to the output This declares a U_BOOT_DRVINFO() for the device being processed Args: node: Node to process """ self.buf('U_BOOT_DRVINFO(%s) = {\n' % node.var_name) self.buf('\t.name\t\t= "%s",\n' % node.struct_name) self.buf('\t.plat\t= &%s%s,\n' % (VAL_PREFIX, node.var_name)) self.buf('\t.plat_size\t= sizeof(%s%s),\n' % (VAL_PREFIX, node.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, node): """Output the definition of a device's struct values Args: node (Node): Node to output """ self.buf('static struct %s%s %s%s = {\n' % (STRUCT_PREFIX, node.struct_name, VAL_PREFIX, node.var_name)) for pname in sorted(node.props): self._output_prop(node, node.props[pname]) self.buf('};\n') def process_nodes(self, need_drivers): nodes_to_output = list(self._valid_nodes) # Figure out which drivers we actually use self._scan.mark_used(nodes_to_output) for node in nodes_to_output: node.dev_ref = 'DM_DEVICE_REF(%s)' % node.var_name driver = self._scan.get_driver(node.struct_name) if not driver: if not need_drivers: continue raise ValueError("Cannot parse/find driver for '%s'" % node.struct_name) node.driver = driver parent_driver = None if node.parent in self._valid_nodes: parent_driver = self._scan.get_driver(node.parent.struct_name) if not parent_driver: if not need_drivers: continue raise ValueError( "Cannot parse/find parent driver '%s' for '%s'" % (node.parent.struct_name, node.struct_name)) node.parent_seq = len(node.parent.child_devs) node.parent.child_devs.append(node) node.parent.child_refs[node.parent_seq] = \ '&%s->sibling_node' % node.dev_ref node.parent_driver = parent_driver for node in nodes_to_output: ref = '&%s->child_head' % node.dev_ref node.child_refs[-1] = ref node.child_refs[len(node.child_devs)] = ref def output_node(self, node): """Output the C code for a node Args: node (fdt.Node): node to output """ self.buf('/* Node %s index %d */\n' % (node.path, node.idx)) self._output_values(node) self._declare_device(node) self.out(''.join(self.get_buf())) def generate_plat(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('/* Allow use of U_BOOT_DRVINFO() in this file */\n') self.out('#define DT_PLAT_C\n') self.out('\n') self.out('#include \n') self.out('#include \n') self.out('#include \n') self.out('\n') for node in self._valid_nodes: self.output_node(node) 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', DtbPlatdata.generate_structs, 'Defines the structs used to hold devicetree data'), 'platdata': OutputFile(Ftype.SOURCE, 'dt-plat.c', DtbPlatdata.generate_plat, 'Declares the U_BOOT_DRIVER() records and platform data'), } def run_steps(args, dtb_file, include_disabled, output, output_dirs, phase, warning_disabled=False, drivers_additional=None, basedir=None, scan=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 phase: The phase of U-Boot that we are generating data for, e.g. 'spl' or 'tpl'. None if not known warning_disabled (bool): True to avoid showing warnings about missing drivers drivers_additional (list): List of additional drivers to use during scanning basedir (str): Base directory of U-Boot source code. Defaults to the grandparent of this file's directory scan (src_src.Scanner): Scanner from a previous run. This can help speed up tests. Use None for normal operation 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') if not scan: scan = src_scan.Scanner(basedir, warning_disabled, drivers_additional, phase) scan.scan_drivers() do_process = True else: do_process = False plat = DtbPlatdata(scan, dtb_file, include_disabled) plat.scan_dtb() plat.scan_tree() plat.prepare_nodes() plat.scan_reg_sizes() plat.setup_output_dirs(output_dirs) plat.scan_structs() plat.scan_phandles() if do_process: plat.process_nodes(False) 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) plat.out_header(outfile) outfile.method(plat) plat.finish_output()