| #!/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 |
| |
| # 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' % ord(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.iteritems(): |
| 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, prop in node.props.items(): |
| 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 xrange(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) |
