1#!/usr/bin/python 2# SPDX-License-Identifier: GPL-2.0+ 3# 4# Copyright (C) 2017 Google, Inc 5# Written by Simon Glass <sjg@chromium.org> 6# 7 8"""Device tree to platform data class 9 10This supports converting device tree data to C structures definitions and 11static data. 12""" 13 14import collections 15import copy 16import sys 17 18import fdt 19import fdt_util 20 21# When we see these properties we ignore them - i.e. do not create a structure member 22PROP_IGNORE_LIST = [ 23 '#address-cells', 24 '#gpio-cells', 25 '#size-cells', 26 'compatible', 27 'linux,phandle', 28 "status", 29 'phandle', 30 'u-boot,dm-pre-reloc', 31 'u-boot,dm-tpl', 32 'u-boot,dm-spl', 33] 34 35# C type declarations for the tyues we support 36TYPE_NAMES = { 37 fdt.TYPE_INT: 'fdt32_t', 38 fdt.TYPE_BYTE: 'unsigned char', 39 fdt.TYPE_STRING: 'const char *', 40 fdt.TYPE_BOOL: 'bool', 41 fdt.TYPE_INT64: 'fdt64_t', 42} 43 44STRUCT_PREFIX = 'dtd_' 45VAL_PREFIX = 'dtv_' 46 47# This holds information about a property which includes phandles. 48# 49# max_args: integer: Maximum number or arguments that any phandle uses (int). 50# args: Number of args for each phandle in the property. The total number of 51# phandles is len(args). This is a list of integers. 52PhandleInfo = collections.namedtuple('PhandleInfo', ['max_args', 'args']) 53 54 55def conv_name_to_c(name): 56 """Convert a device-tree name to a C identifier 57 58 This uses multiple replace() calls instead of re.sub() since it is faster 59 (400ms for 1m calls versus 1000ms for the 're' version). 60 61 Args: 62 name: Name to convert 63 Return: 64 String containing the C version of this name 65 """ 66 new = name.replace('@', '_at_') 67 new = new.replace('-', '_') 68 new = new.replace(',', '_') 69 new = new.replace('.', '_') 70 return new 71 72def tab_to(num_tabs, line): 73 """Append tabs to a line of text to reach a tab stop. 74 75 Args: 76 num_tabs: Tab stop to obtain (0 = column 0, 1 = column 8, etc.) 77 line: Line of text to append to 78 79 Returns: 80 line with the correct number of tabs appeneded. If the line already 81 extends past that tab stop then a single space is appended. 82 """ 83 if len(line) >= num_tabs * 8: 84 return line + ' ' 85 return line + '\t' * (num_tabs - len(line) // 8) 86 87def get_value(ftype, value): 88 """Get a value as a C expression 89 90 For integers this returns a byte-swapped (little-endian) hex string 91 For bytes this returns a hex string, e.g. 0x12 92 For strings this returns a literal string enclosed in quotes 93 For booleans this return 'true' 94 95 Args: 96 type: Data type (fdt_util) 97 value: Data value, as a string of bytes 98 """ 99 if ftype == fdt.TYPE_INT: 100 return '%#x' % fdt_util.fdt32_to_cpu(value) 101 elif ftype == fdt.TYPE_BYTE: 102 return '%#x' % ord(value[0]) 103 elif ftype == fdt.TYPE_STRING: 104 return '"%s"' % value 105 elif ftype == fdt.TYPE_BOOL: 106 return 'true' 107 elif ftype == fdt.TYPE_INT64: 108 return '%#x' % value 109 110def get_compat_name(node): 111 """Get a node's first compatible string as a C identifier 112 113 Args: 114 node: Node object to check 115 Return: 116 Tuple: 117 C identifier for the first compatible string 118 List of C identifiers for all the other compatible strings 119 (possibly empty) 120 """ 121 compat = node.props['compatible'].value 122 aliases = [] 123 if isinstance(compat, list): 124 compat, aliases = compat[0], compat[1:] 125 return conv_name_to_c(compat), [conv_name_to_c(a) for a in aliases] 126 127 128class DtbPlatdata(object): 129 """Provide a means to convert device tree binary data to platform data 130 131 The output of this process is C structures which can be used in space- 132 constrained encvironments where the ~3KB code overhead of device tree 133 code is not affordable. 134 135 Properties: 136 _fdt: Fdt object, referencing the device tree 137 _dtb_fname: Filename of the input device tree binary file 138 _valid_nodes: A list of Node object with compatible strings 139 _include_disabled: true to include nodes marked status = "disabled" 140 _outfile: The current output file (sys.stdout or a real file) 141 _lines: Stashed list of output lines for outputting in the future 142 """ 143 def __init__(self, dtb_fname, include_disabled): 144 self._fdt = None 145 self._dtb_fname = dtb_fname 146 self._valid_nodes = None 147 self._include_disabled = include_disabled 148 self._outfile = None 149 self._lines = [] 150 self._aliases = {} 151 152 def setup_output(self, fname): 153 """Set up the output destination 154 155 Once this is done, future calls to self.out() will output to this 156 file. 157 158 Args: 159 fname: Filename to send output to, or '-' for stdout 160 """ 161 if fname == '-': 162 self._outfile = sys.stdout 163 else: 164 self._outfile = open(fname, 'w') 165 166 def out(self, line): 167 """Output a string to the output file 168 169 Args: 170 line: String to output 171 """ 172 self._outfile.write(line) 173 174 def buf(self, line): 175 """Buffer up a string to send later 176 177 Args: 178 line: String to add to our 'buffer' list 179 """ 180 self._lines.append(line) 181 182 def get_buf(self): 183 """Get the contents of the output buffer, and clear it 184 185 Returns: 186 The output buffer, which is then cleared for future use 187 """ 188 lines = self._lines 189 self._lines = [] 190 return lines 191 192 def out_header(self): 193 """Output a message indicating that this is an auto-generated file""" 194 self.out('''/* 195 * DO NOT MODIFY 196 * 197 * This file was generated by dtoc from a .dtb (device tree binary) file. 198 */ 199 200''') 201 202 def get_phandle_argc(self, prop, node_name): 203 """Check if a node contains phandles 204 205 We have no reliable way of detecting whether a node uses a phandle 206 or not. As an interim measure, use a list of known property names. 207 208 Args: 209 prop: Prop object to check 210 Return: 211 Number of argument cells is this is a phandle, else None 212 """ 213 if prop.name in ['clocks']: 214 if not isinstance(prop.value, list): 215 prop.value = [prop.value] 216 val = prop.value 217 i = 0 218 219 max_args = 0 220 args = [] 221 while i < len(val): 222 phandle = fdt_util.fdt32_to_cpu(val[i]) 223 # If we get to the end of the list, stop. This can happen 224 # since some nodes have more phandles in the list than others, 225 # but we allocate enough space for the largest list. So those 226 # nodes with shorter lists end up with zeroes at the end. 227 if not phandle: 228 break 229 target = self._fdt.phandle_to_node.get(phandle) 230 if not target: 231 raise ValueError("Cannot parse '%s' in node '%s'" % 232 (prop.name, node_name)) 233 prop_name = '#clock-cells' 234 cells = target.props.get(prop_name) 235 if not cells: 236 raise ValueError("Node '%s' has no '%s' property" % 237 (target.name, prop_name)) 238 num_args = fdt_util.fdt32_to_cpu(cells.value) 239 max_args = max(max_args, num_args) 240 args.append(num_args) 241 i += 1 + num_args 242 return PhandleInfo(max_args, args) 243 return None 244 245 def scan_dtb(self): 246 """Scan the device tree to obtain a tree of nodes and properties 247 248 Once this is done, self._fdt.GetRoot() can be called to obtain the 249 device tree root node, and progress from there. 250 """ 251 self._fdt = fdt.FdtScan(self._dtb_fname) 252 253 def scan_node(self, root): 254 """Scan a node and subnodes to build a tree of node and phandle info 255 256 This adds each node to self._valid_nodes. 257 258 Args: 259 root: Root node for scan 260 """ 261 for node in root.subnodes: 262 if 'compatible' in node.props: 263 status = node.props.get('status') 264 if (not self._include_disabled and not status or 265 status.value != 'disabled'): 266 self._valid_nodes.append(node) 267 268 # recurse to handle any subnodes 269 self.scan_node(node) 270 271 def scan_tree(self): 272 """Scan the device tree for useful information 273 274 This fills in the following properties: 275 _valid_nodes: A list of nodes we wish to consider include in the 276 platform data 277 """ 278 self._valid_nodes = [] 279 return self.scan_node(self._fdt.GetRoot()) 280 281 @staticmethod 282 def get_num_cells(node): 283 """Get the number of cells in addresses and sizes for this node 284 285 Args: 286 node: Node to check 287 288 Returns: 289 Tuple: 290 Number of address cells for this node 291 Number of size cells for this node 292 """ 293 parent = node.parent 294 na, ns = 2, 2 295 if parent: 296 na_prop = parent.props.get('#address-cells') 297 ns_prop = parent.props.get('#size-cells') 298 if na_prop: 299 na = fdt_util.fdt32_to_cpu(na_prop.value) 300 if ns_prop: 301 ns = fdt_util.fdt32_to_cpu(ns_prop.value) 302 return na, ns 303 304 def scan_reg_sizes(self): 305 """Scan for 64-bit 'reg' properties and update the values 306 307 This finds 'reg' properties with 64-bit data and converts the value to 308 an array of 64-values. This allows it to be output in a way that the 309 C code can read. 310 """ 311 for node in self._valid_nodes: 312 reg = node.props.get('reg') 313 if not reg: 314 continue 315 na, ns = self.get_num_cells(node) 316 total = na + ns 317 318 if reg.type != fdt.TYPE_INT: 319 raise ValueError("Node '%s' reg property is not an int") 320 if len(reg.value) % total: 321 raise ValueError("Node '%s' reg property has %d cells " 322 'which is not a multiple of na + ns = %d + %d)' % 323 (node.name, len(reg.value), na, ns)) 324 reg.na = na 325 reg.ns = ns 326 if na != 1 or ns != 1: 327 reg.type = fdt.TYPE_INT64 328 i = 0 329 new_value = [] 330 val = reg.value 331 if not isinstance(val, list): 332 val = [val] 333 while i < len(val): 334 addr = fdt_util.fdt_cells_to_cpu(val[i:], reg.na) 335 i += na 336 size = fdt_util.fdt_cells_to_cpu(val[i:], reg.ns) 337 i += ns 338 new_value += [addr, size] 339 reg.value = new_value 340 341 def scan_structs(self): 342 """Scan the device tree building up the C structures we will use. 343 344 Build a dict keyed by C struct name containing a dict of Prop 345 object for each struct field (keyed by property name). Where the 346 same struct appears multiple times, try to use the 'widest' 347 property, i.e. the one with a type which can express all others. 348 349 Once the widest property is determined, all other properties are 350 updated to match that width. 351 """ 352 structs = {} 353 for node in self._valid_nodes: 354 node_name, _ = get_compat_name(node) 355 fields = {} 356 357 # Get a list of all the valid properties in this node. 358 for name, prop in node.props.items(): 359 if name not in PROP_IGNORE_LIST and name[0] != '#': 360 fields[name] = copy.deepcopy(prop) 361 362 # If we've seen this node_name before, update the existing struct. 363 if node_name in structs: 364 struct = structs[node_name] 365 for name, prop in fields.items(): 366 oldprop = struct.get(name) 367 if oldprop: 368 oldprop.Widen(prop) 369 else: 370 struct[name] = prop 371 372 # Otherwise store this as a new struct. 373 else: 374 structs[node_name] = fields 375 376 upto = 0 377 for node in self._valid_nodes: 378 node_name, _ = get_compat_name(node) 379 struct = structs[node_name] 380 for name, prop in node.props.items(): 381 if name not in PROP_IGNORE_LIST and name[0] != '#': 382 prop.Widen(struct[name]) 383 upto += 1 384 385 struct_name, aliases = get_compat_name(node) 386 for alias in aliases: 387 self._aliases[alias] = struct_name 388 389 return structs 390 391 def scan_phandles(self): 392 """Figure out what phandles each node uses 393 394 We need to be careful when outputing nodes that use phandles since 395 they must come after the declaration of the phandles in the C file. 396 Otherwise we get a compiler error since the phandle struct is not yet 397 declared. 398 399 This function adds to each node a list of phandle nodes that the node 400 depends on. This allows us to output things in the right order. 401 """ 402 for node in self._valid_nodes: 403 node.phandles = set() 404 for pname, prop in node.props.items(): 405 if pname in PROP_IGNORE_LIST or pname[0] == '#': 406 continue 407 info = self.get_phandle_argc(prop, node.name) 408 if info: 409 # Process the list as pairs of (phandle, id) 410 pos = 0 411 for args in info.args: 412 phandle_cell = prop.value[pos] 413 phandle = fdt_util.fdt32_to_cpu(phandle_cell) 414 target_node = self._fdt.phandle_to_node[phandle] 415 node.phandles.add(target_node) 416 pos += 1 + args 417 418 419 def generate_structs(self, structs): 420 """Generate struct defintions for the platform data 421 422 This writes out the body of a header file consisting of structure 423 definitions for node in self._valid_nodes. See the documentation in 424 README.of-plat for more information. 425 """ 426 self.out_header() 427 self.out('#include <stdbool.h>\n') 428 self.out('#include <linux/libfdt.h>\n') 429 430 # Output the struct definition 431 for name in sorted(structs): 432 self.out('struct %s%s {\n' % (STRUCT_PREFIX, name)) 433 for pname in sorted(structs[name]): 434 prop = structs[name][pname] 435 info = self.get_phandle_argc(prop, structs[name]) 436 if info: 437 # For phandles, include a reference to the target 438 struct_name = 'struct phandle_%d_arg' % info.max_args 439 self.out('\t%s%s[%d]' % (tab_to(2, struct_name), 440 conv_name_to_c(prop.name), 441 len(info.args))) 442 else: 443 ptype = TYPE_NAMES[prop.type] 444 self.out('\t%s%s' % (tab_to(2, ptype), 445 conv_name_to_c(prop.name))) 446 if isinstance(prop.value, list): 447 self.out('[%d]' % len(prop.value)) 448 self.out(';\n') 449 self.out('};\n') 450 451 for alias, struct_name in self._aliases.iteritems(): 452 self.out('#define %s%s %s%s\n'% (STRUCT_PREFIX, alias, 453 STRUCT_PREFIX, struct_name)) 454 455 def output_node(self, node): 456 """Output the C code for a node 457 458 Args: 459 node: node to output 460 """ 461 struct_name, _ = get_compat_name(node) 462 var_name = conv_name_to_c(node.name) 463 self.buf('static struct %s%s %s%s = {\n' % 464 (STRUCT_PREFIX, struct_name, VAL_PREFIX, var_name)) 465 for pname, prop in node.props.items(): 466 if pname in PROP_IGNORE_LIST or pname[0] == '#': 467 continue 468 member_name = conv_name_to_c(prop.name) 469 self.buf('\t%s= ' % tab_to(3, '.' + member_name)) 470 471 # Special handling for lists 472 if isinstance(prop.value, list): 473 self.buf('{') 474 vals = [] 475 # For phandles, output a reference to the platform data 476 # of the target node. 477 info = self.get_phandle_argc(prop, node.name) 478 if info: 479 # Process the list as pairs of (phandle, id) 480 pos = 0 481 for args in info.args: 482 phandle_cell = prop.value[pos] 483 phandle = fdt_util.fdt32_to_cpu(phandle_cell) 484 target_node = self._fdt.phandle_to_node[phandle] 485 name = conv_name_to_c(target_node.name) 486 arg_values = [] 487 for i in range(args): 488 arg_values.append(str(fdt_util.fdt32_to_cpu(prop.value[pos + 1 + i]))) 489 pos += 1 + args 490 vals.append('\t{&%s%s, {%s}}' % (VAL_PREFIX, name, 491 ', '.join(arg_values))) 492 for val in vals: 493 self.buf('\n\t\t%s,' % val) 494 else: 495 for val in prop.value: 496 vals.append(get_value(prop.type, val)) 497 498 # Put 8 values per line to avoid very long lines. 499 for i in xrange(0, len(vals), 8): 500 if i: 501 self.buf(',\n\t\t') 502 self.buf(', '.join(vals[i:i + 8])) 503 self.buf('}') 504 else: 505 self.buf(get_value(prop.type, prop.value)) 506 self.buf(',\n') 507 self.buf('};\n') 508 509 # Add a device declaration 510 self.buf('U_BOOT_DEVICE(%s) = {\n' % var_name) 511 self.buf('\t.name\t\t= "%s",\n' % struct_name) 512 self.buf('\t.platdata\t= &%s%s,\n' % (VAL_PREFIX, var_name)) 513 self.buf('\t.platdata_size\t= sizeof(%s%s),\n' % (VAL_PREFIX, var_name)) 514 self.buf('};\n') 515 self.buf('\n') 516 517 self.out(''.join(self.get_buf())) 518 519 def generate_tables(self): 520 """Generate device defintions for the platform data 521 522 This writes out C platform data initialisation data and 523 U_BOOT_DEVICE() declarations for each valid node. Where a node has 524 multiple compatible strings, a #define is used to make them equivalent. 525 526 See the documentation in doc/driver-model/of-plat.txt for more 527 information. 528 """ 529 self.out_header() 530 self.out('#include <common.h>\n') 531 self.out('#include <dm.h>\n') 532 self.out('#include <dt-structs.h>\n') 533 self.out('\n') 534 nodes_to_output = list(self._valid_nodes) 535 536 # Keep outputing nodes until there is none left 537 while nodes_to_output: 538 node = nodes_to_output[0] 539 # Output all the node's dependencies first 540 for req_node in node.phandles: 541 if req_node in nodes_to_output: 542 self.output_node(req_node) 543 nodes_to_output.remove(req_node) 544 self.output_node(node) 545 nodes_to_output.remove(node) 546 547 548def run_steps(args, dtb_file, include_disabled, output): 549 """Run all the steps of the dtoc tool 550 551 Args: 552 args: List of non-option arguments provided to the problem 553 dtb_file: Filename of dtb file to process 554 include_disabled: True to include disabled nodes 555 output: Name of output file 556 """ 557 if not args: 558 raise ValueError('Please specify a command: struct, platdata') 559 560 plat = DtbPlatdata(dtb_file, include_disabled) 561 plat.scan_dtb() 562 plat.scan_tree() 563 plat.scan_reg_sizes() 564 plat.setup_output(output) 565 structs = plat.scan_structs() 566 plat.scan_phandles() 567 568 for cmd in args[0].split(','): 569 if cmd == 'struct': 570 plat.generate_structs(structs) 571 elif cmd == 'platdata': 572 plat.generate_tables() 573 else: 574 raise ValueError("Unknown command '%s': (use: struct, platdata)" % 575 cmd) 576