1 /* 2 * libfdt - Flat Device Tree manipulation 3 * Copyright (C) 2006 David Gibson, IBM Corporation. 4 * 5 * libfdt is dual licensed: you can use it either under the terms of 6 * the GPL, or the BSD license, at your option. 7 * 8 * a) This library is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License as 10 * published by the Free Software Foundation; either version 2 of the 11 * License, or (at your option) any later version. 12 * 13 * This library is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public 19 * License along with this library; if not, write to the Free 20 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, 21 * MA 02110-1301 USA 22 * 23 * Alternatively, 24 * 25 * b) Redistribution and use in source and binary forms, with or 26 * without modification, are permitted provided that the following 27 * conditions are met: 28 * 29 * 1. Redistributions of source code must retain the above 30 * copyright notice, this list of conditions and the following 31 * disclaimer. 32 * 2. Redistributions in binary form must reproduce the above 33 * copyright notice, this list of conditions and the following 34 * disclaimer in the documentation and/or other materials 35 * provided with the distribution. 36 * 37 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 38 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 39 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 40 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 41 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 42 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 43 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 44 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 45 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 46 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 47 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 48 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 49 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 50 */ 51 #include "libfdt_env.h" 52 53 #ifndef USE_HOSTCC 54 #include <fdt.h> 55 #include <libfdt.h> 56 #else 57 #include "fdt_host.h" 58 #endif 59 60 #include "libfdt_internal.h" 61 62 static int _fdt_nodename_eq(const void *fdt, int offset, 63 const char *s, int len) 64 { 65 const char *p = fdt_offset_ptr(fdt, offset + FDT_TAGSIZE, len+1); 66 67 if (! p) 68 /* short match */ 69 return 0; 70 71 if (memcmp(p, s, len) != 0) 72 return 0; 73 74 if (p[len] == '\0') 75 return 1; 76 else if (!memchr(s, '@', len) && (p[len] == '@')) 77 return 1; 78 else 79 return 0; 80 } 81 82 const char *fdt_string(const void *fdt, int stroffset) 83 { 84 return (const char *)fdt + fdt_off_dt_strings(fdt) + stroffset; 85 } 86 87 static int _fdt_string_eq(const void *fdt, int stroffset, 88 const char *s, int len) 89 { 90 const char *p = fdt_string(fdt, stroffset); 91 92 return (strlen(p) == len) && (memcmp(p, s, len) == 0); 93 } 94 95 int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size) 96 { 97 FDT_CHECK_HEADER(fdt); 98 *address = fdt64_to_cpu(_fdt_mem_rsv(fdt, n)->address); 99 *size = fdt64_to_cpu(_fdt_mem_rsv(fdt, n)->size); 100 return 0; 101 } 102 103 int fdt_num_mem_rsv(const void *fdt) 104 { 105 int i = 0; 106 107 while (fdt64_to_cpu(_fdt_mem_rsv(fdt, i)->size) != 0) 108 i++; 109 return i; 110 } 111 112 static int _nextprop(const void *fdt, int offset) 113 { 114 uint32_t tag; 115 int nextoffset; 116 117 do { 118 tag = fdt_next_tag(fdt, offset, &nextoffset); 119 120 switch (tag) { 121 case FDT_END: 122 if (nextoffset >= 0) 123 return -FDT_ERR_BADSTRUCTURE; 124 else 125 return nextoffset; 126 127 case FDT_PROP: 128 return offset; 129 } 130 offset = nextoffset; 131 } while (tag == FDT_NOP); 132 133 return -FDT_ERR_NOTFOUND; 134 } 135 136 int fdt_subnode_offset_namelen(const void *fdt, int offset, 137 const char *name, int namelen) 138 { 139 int depth; 140 141 FDT_CHECK_HEADER(fdt); 142 143 for (depth = 0; 144 (offset >= 0) && (depth >= 0); 145 offset = fdt_next_node(fdt, offset, &depth)) 146 if ((depth == 1) 147 && _fdt_nodename_eq(fdt, offset, name, namelen)) 148 return offset; 149 150 if (depth < 0) 151 return -FDT_ERR_NOTFOUND; 152 return offset; /* error */ 153 } 154 155 int fdt_subnode_offset(const void *fdt, int parentoffset, 156 const char *name) 157 { 158 return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name)); 159 } 160 161 int fdt_path_offset(const void *fdt, const char *path) 162 { 163 const char *end = path + strlen(path); 164 const char *p = path; 165 int offset = 0; 166 167 FDT_CHECK_HEADER(fdt); 168 169 /* see if we have an alias */ 170 if (*path != '/') { 171 const char *q = strchr(path, '/'); 172 173 if (!q) 174 q = end; 175 176 p = fdt_get_alias_namelen(fdt, p, q - p); 177 if (!p) 178 return -FDT_ERR_BADPATH; 179 offset = fdt_path_offset(fdt, p); 180 181 p = q; 182 } 183 184 while (*p) { 185 const char *q; 186 187 while (*p == '/') 188 p++; 189 if (! *p) 190 return offset; 191 q = strchr(p, '/'); 192 if (! q) 193 q = end; 194 195 offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p); 196 if (offset < 0) 197 return offset; 198 199 p = q; 200 } 201 202 return offset; 203 } 204 205 const char *fdt_get_name(const void *fdt, int nodeoffset, int *len) 206 { 207 const struct fdt_node_header *nh = _fdt_offset_ptr(fdt, nodeoffset); 208 int err; 209 210 if (((err = fdt_check_header(fdt)) != 0) 211 || ((err = _fdt_check_node_offset(fdt, nodeoffset)) < 0)) 212 goto fail; 213 214 if (len) 215 *len = strlen(nh->name); 216 217 return nh->name; 218 219 fail: 220 if (len) 221 *len = err; 222 return NULL; 223 } 224 225 int fdt_first_property_offset(const void *fdt, int nodeoffset) 226 { 227 int offset; 228 229 if ((offset = _fdt_check_node_offset(fdt, nodeoffset)) < 0) 230 return offset; 231 232 return _nextprop(fdt, offset); 233 } 234 235 int fdt_next_property_offset(const void *fdt, int offset) 236 { 237 if ((offset = _fdt_check_prop_offset(fdt, offset)) < 0) 238 return offset; 239 240 return _nextprop(fdt, offset); 241 } 242 243 const struct fdt_property *fdt_get_property_by_offset(const void *fdt, 244 int offset, 245 int *lenp) 246 { 247 int err; 248 const struct fdt_property *prop; 249 250 if ((err = _fdt_check_prop_offset(fdt, offset)) < 0) { 251 if (lenp) 252 *lenp = err; 253 return NULL; 254 } 255 256 prop = _fdt_offset_ptr(fdt, offset); 257 258 if (lenp) 259 *lenp = fdt32_to_cpu(prop->len); 260 261 return prop; 262 } 263 264 const struct fdt_property *fdt_get_property_namelen(const void *fdt, 265 int offset, 266 const char *name, 267 int namelen, int *lenp) 268 { 269 for (offset = fdt_first_property_offset(fdt, offset); 270 (offset >= 0); 271 (offset = fdt_next_property_offset(fdt, offset))) { 272 const struct fdt_property *prop; 273 274 if (!(prop = fdt_get_property_by_offset(fdt, offset, lenp))) { 275 offset = -FDT_ERR_INTERNAL; 276 break; 277 } 278 if (_fdt_string_eq(fdt, fdt32_to_cpu(prop->nameoff), 279 name, namelen)) 280 return prop; 281 } 282 283 if (lenp) 284 *lenp = offset; 285 return NULL; 286 } 287 288 const struct fdt_property *fdt_get_property(const void *fdt, 289 int nodeoffset, 290 const char *name, int *lenp) 291 { 292 return fdt_get_property_namelen(fdt, nodeoffset, name, 293 strlen(name), lenp); 294 } 295 296 const void *fdt_getprop_namelen(const void *fdt, int nodeoffset, 297 const char *name, int namelen, int *lenp) 298 { 299 const struct fdt_property *prop; 300 301 prop = fdt_get_property_namelen(fdt, nodeoffset, name, namelen, lenp); 302 if (! prop) 303 return NULL; 304 305 return prop->data; 306 } 307 308 const void *fdt_getprop_by_offset(const void *fdt, int offset, 309 const char **namep, int *lenp) 310 { 311 const struct fdt_property *prop; 312 313 prop = fdt_get_property_by_offset(fdt, offset, lenp); 314 if (!prop) 315 return NULL; 316 if (namep) 317 *namep = fdt_string(fdt, fdt32_to_cpu(prop->nameoff)); 318 return prop->data; 319 } 320 321 const void *fdt_getprop(const void *fdt, int nodeoffset, 322 const char *name, int *lenp) 323 { 324 return fdt_getprop_namelen(fdt, nodeoffset, name, strlen(name), lenp); 325 } 326 327 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset) 328 { 329 const uint32_t *php; 330 int len; 331 332 /* FIXME: This is a bit sub-optimal, since we potentially scan 333 * over all the properties twice. */ 334 php = fdt_getprop(fdt, nodeoffset, "phandle", &len); 335 if (!php || (len != sizeof(*php))) { 336 php = fdt_getprop(fdt, nodeoffset, "linux,phandle", &len); 337 if (!php || (len != sizeof(*php))) 338 return 0; 339 } 340 341 return fdt32_to_cpu(*php); 342 } 343 344 const char *fdt_get_alias_namelen(const void *fdt, 345 const char *name, int namelen) 346 { 347 int aliasoffset; 348 349 aliasoffset = fdt_path_offset(fdt, "/aliases"); 350 if (aliasoffset < 0) 351 return NULL; 352 353 return fdt_getprop_namelen(fdt, aliasoffset, name, namelen, NULL); 354 } 355 356 const char *fdt_get_alias(const void *fdt, const char *name) 357 { 358 return fdt_get_alias_namelen(fdt, name, strlen(name)); 359 } 360 361 int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen) 362 { 363 int pdepth = 0, p = 0; 364 int offset, depth, namelen; 365 const char *name; 366 367 FDT_CHECK_HEADER(fdt); 368 369 if (buflen < 2) 370 return -FDT_ERR_NOSPACE; 371 372 for (offset = 0, depth = 0; 373 (offset >= 0) && (offset <= nodeoffset); 374 offset = fdt_next_node(fdt, offset, &depth)) { 375 while (pdepth > depth) { 376 do { 377 p--; 378 } while (buf[p-1] != '/'); 379 pdepth--; 380 } 381 382 if (pdepth >= depth) { 383 name = fdt_get_name(fdt, offset, &namelen); 384 if (!name) 385 return namelen; 386 if ((p + namelen + 1) <= buflen) { 387 memcpy(buf + p, name, namelen); 388 p += namelen; 389 buf[p++] = '/'; 390 pdepth++; 391 } 392 } 393 394 if (offset == nodeoffset) { 395 if (pdepth < (depth + 1)) 396 return -FDT_ERR_NOSPACE; 397 398 if (p > 1) /* special case so that root path is "/", not "" */ 399 p--; 400 buf[p] = '\0'; 401 return 0; 402 } 403 } 404 405 if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0)) 406 return -FDT_ERR_BADOFFSET; 407 else if (offset == -FDT_ERR_BADOFFSET) 408 return -FDT_ERR_BADSTRUCTURE; 409 410 return offset; /* error from fdt_next_node() */ 411 } 412 413 int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset, 414 int supernodedepth, int *nodedepth) 415 { 416 int offset, depth; 417 int supernodeoffset = -FDT_ERR_INTERNAL; 418 419 FDT_CHECK_HEADER(fdt); 420 421 if (supernodedepth < 0) 422 return -FDT_ERR_NOTFOUND; 423 424 for (offset = 0, depth = 0; 425 (offset >= 0) && (offset <= nodeoffset); 426 offset = fdt_next_node(fdt, offset, &depth)) { 427 if (depth == supernodedepth) 428 supernodeoffset = offset; 429 430 if (offset == nodeoffset) { 431 if (nodedepth) 432 *nodedepth = depth; 433 434 if (supernodedepth > depth) 435 return -FDT_ERR_NOTFOUND; 436 else 437 return supernodeoffset; 438 } 439 } 440 441 if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0)) 442 return -FDT_ERR_BADOFFSET; 443 else if (offset == -FDT_ERR_BADOFFSET) 444 return -FDT_ERR_BADSTRUCTURE; 445 446 return offset; /* error from fdt_next_node() */ 447 } 448 449 int fdt_node_depth(const void *fdt, int nodeoffset) 450 { 451 int nodedepth; 452 int err; 453 454 err = fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, &nodedepth); 455 if (err) 456 return (err < 0) ? err : -FDT_ERR_INTERNAL; 457 return nodedepth; 458 } 459 460 int fdt_parent_offset(const void *fdt, int nodeoffset) 461 { 462 int nodedepth = fdt_node_depth(fdt, nodeoffset); 463 464 if (nodedepth < 0) 465 return nodedepth; 466 return fdt_supernode_atdepth_offset(fdt, nodeoffset, 467 nodedepth - 1, NULL); 468 } 469 470 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset, 471 const char *propname, 472 const void *propval, int proplen) 473 { 474 int offset; 475 const void *val; 476 int len; 477 478 FDT_CHECK_HEADER(fdt); 479 480 /* FIXME: The algorithm here is pretty horrible: we scan each 481 * property of a node in fdt_getprop(), then if that didn't 482 * find what we want, we scan over them again making our way 483 * to the next node. Still it's the easiest to implement 484 * approach; performance can come later. */ 485 for (offset = fdt_next_node(fdt, startoffset, NULL); 486 offset >= 0; 487 offset = fdt_next_node(fdt, offset, NULL)) { 488 val = fdt_getprop(fdt, offset, propname, &len); 489 if (val && (len == proplen) 490 && (memcmp(val, propval, len) == 0)) 491 return offset; 492 } 493 494 return offset; /* error from fdt_next_node() */ 495 } 496 497 int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle) 498 { 499 int offset; 500 501 if ((phandle == 0) || (phandle == -1)) 502 return -FDT_ERR_BADPHANDLE; 503 504 FDT_CHECK_HEADER(fdt); 505 506 /* FIXME: The algorithm here is pretty horrible: we 507 * potentially scan each property of a node in 508 * fdt_get_phandle(), then if that didn't find what 509 * we want, we scan over them again making our way to the next 510 * node. Still it's the easiest to implement approach; 511 * performance can come later. */ 512 for (offset = fdt_next_node(fdt, -1, NULL); 513 offset >= 0; 514 offset = fdt_next_node(fdt, offset, NULL)) { 515 if (fdt_get_phandle(fdt, offset) == phandle) 516 return offset; 517 } 518 519 return offset; /* error from fdt_next_node() */ 520 } 521 522 static int _fdt_stringlist_contains(const char *strlist, int listlen, 523 const char *str) 524 { 525 int len = strlen(str); 526 const char *p; 527 528 while (listlen >= len) { 529 if (memcmp(str, strlist, len+1) == 0) 530 return 1; 531 p = memchr(strlist, '\0', listlen); 532 if (!p) 533 return 0; /* malformed strlist.. */ 534 listlen -= (p-strlist) + 1; 535 strlist = p + 1; 536 } 537 return 0; 538 } 539 540 int fdt_node_check_compatible(const void *fdt, int nodeoffset, 541 const char *compatible) 542 { 543 const void *prop; 544 int len; 545 546 prop = fdt_getprop(fdt, nodeoffset, "compatible", &len); 547 if (!prop) 548 return len; 549 if (_fdt_stringlist_contains(prop, len, compatible)) 550 return 0; 551 else 552 return 1; 553 } 554 555 int fdt_node_offset_by_compatible(const void *fdt, int startoffset, 556 const char *compatible) 557 { 558 int offset, err; 559 560 FDT_CHECK_HEADER(fdt); 561 562 /* FIXME: The algorithm here is pretty horrible: we scan each 563 * property of a node in fdt_node_check_compatible(), then if 564 * that didn't find what we want, we scan over them again 565 * making our way to the next node. Still it's the easiest to 566 * implement approach; performance can come later. */ 567 for (offset = fdt_next_node(fdt, startoffset, NULL); 568 offset >= 0; 569 offset = fdt_next_node(fdt, offset, NULL)) { 570 err = fdt_node_check_compatible(fdt, offset, compatible); 571 if ((err < 0) && (err != -FDT_ERR_NOTFOUND)) 572 return err; 573 else if (err == 0) 574 return offset; 575 } 576 577 return offset; /* error from fdt_next_node() */ 578 } 579