libfdt/fdt_ro.c

   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 int fdt_subnode_offset_namelen(const void *fdt, int offset,
 113                                const char *name, int namelen)
 114 {
 115         int depth;
 116
 117         FDT_CHECK_HEADER(fdt);
 118
 119         for (depth = 0;
 120              (offset >= 0) && (depth >= 0);
 121              offset = fdt_next_node(fdt, offset, &depth))
 122                 if ((depth == 1)
 123                     && _fdt_nodename_eq(fdt, offset, name, namelen))
 124                         return offset;
 125
 126         if (depth < 0)
 127                 return -FDT_ERR_NOTFOUND;
 128         return offset; /* error */
 129 }
 130
 131 int fdt_subnode_offset(const void *fdt, int parentoffset,
 132                        const char *name)
 133 {
 134         return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name));
 135 }
 136
 137 int fdt_path_offset(const void *fdt, const char *path)
 138 {
 139         const char *end = path + strlen(path);
 140         const char *p = path;
 141         int offset = 0;
 142
 143         FDT_CHECK_HEADER(fdt);
 144
 145         /* see if we have an alias */
 146         if (*path != '/') {
 147                 const char *q = strchr(path, '/');
 148
 149                 if (!q)
 150                         q = end;
 151
 152                 p = fdt_get_alias_namelen(fdt, p, q - p);
 153                 if (!p)
 154                         return -FDT_ERR_BADPATH;
 155                 offset = fdt_path_offset(fdt, p);
 156
 157                 p = q;
 158         }
 159
 160         while (*p) {
 161                 const char *q;
 162
 163                 while (*p == '/')
 164                         p++;
 165                 if (! *p)
 166                         return offset;
 167                 q = strchr(p, '/');
 168                 if (! q)
 169                         q = end;
 170
 171                 offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p);
 172                 if (offset < 0)
 173                         return offset;
 174
 175                 p = q;
 176         }
 177
 178         return offset;
 179 }
 180
 181 const char *fdt_get_name(const void *fdt, int nodeoffset, int *len)
 182 {
 183         const struct fdt_node_header *nh = _fdt_offset_ptr(fdt, nodeoffset);
 184         int err;
 185
 186         if (((err = fdt_check_header(fdt)) != 0)
 187             || ((err = _fdt_check_node_offset(fdt, nodeoffset)) < 0))
 188                         goto fail;
 189
 190         if (len)
 191                 *len = strlen(nh->name);
 192
 193         return nh->name;
 194
 195  fail:
 196         if (len)
 197                 *len = err;
 198         return NULL;
 199 }
 200
 201 const struct fdt_property *fdt_get_property_namelen(const void *fdt,
 202                                                     int nodeoffset,
 203                                                     const char *name,
 204                                                     int namelen, int *lenp)
 205 {
 206         uint32_t tag;
 207         const struct fdt_property *prop;
 208         int offset, nextoffset;
 209         int err;
 210
 211         if (((err = fdt_check_header(fdt)) != 0)
 212             || ((err = _fdt_check_node_offset(fdt, nodeoffset)) < 0))
 213                         goto fail;
 214
 215         nextoffset = err;
 216         do {
 217                 offset = nextoffset;
 218
 219                 tag = fdt_next_tag(fdt, offset, &nextoffset);
 220                 switch (tag) {
 221                 case FDT_END:
 222                         if (nextoffset < 0)
 223                                 err = nextoffset;
 224                         else
 225                                 /* FDT_END tag with unclosed nodes */
 226                                 err = -FDT_ERR_BADSTRUCTURE;
 227                         goto fail;
 228
 229                 case FDT_PROP:
 230                         prop = _fdt_offset_ptr(fdt, offset);
 231                         if (_fdt_string_eq(fdt, fdt32_to_cpu(prop->nameoff),
 232                                            name, namelen)) {
 233                                 /* Found it! */
 234                                 if (lenp)
 235                                         *lenp = fdt32_to_cpu(prop->len);
 236
 237                                 return prop;
 238                         }
 239                         break;
 240                 }
 241         } while ((tag != FDT_BEGIN_NODE) && (tag != FDT_END_NODE));
 242
 243         err = -FDT_ERR_NOTFOUND;
 244  fail:
 245         if (lenp)
 246                 *lenp = err;
 247         return NULL;
 248 }
 249
 250 const struct fdt_property *fdt_get_property(const void *fdt,
 251                                             int nodeoffset,
 252                                             const char *name, int *lenp)
 253 {
 254         return fdt_get_property_namelen(fdt, nodeoffset, name,
 255                                         strlen(name), lenp);
 256 }
 257
 258 const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
 259                                 const char *name, int namelen, int *lenp)
 260 {
 261         const struct fdt_property *prop;
 262
 263         prop = fdt_get_property_namelen(fdt, nodeoffset, name, namelen, lenp);
 264         if (! prop)
 265                 return NULL;
 266
 267         return prop->data;
 268 }
 269
 270 const void *fdt_getprop(const void *fdt, int nodeoffset,
 271                         const char *name, int *lenp)
 272 {
 273         return fdt_getprop_namelen(fdt, nodeoffset, name, strlen(name), lenp);
 274 }
 275
 276 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
 277 {
 278         const uint32_t *php;
 279         int len;
 280
 281         php = fdt_getprop(fdt, nodeoffset, "linux,phandle", &len);
 282         if (!php || (len != sizeof(*php)))
 283                 return 0;
 284
 285         return fdt32_to_cpu(*php);
 286 }
 287
 288 const char *fdt_get_alias_namelen(const void *fdt,
 289                                   const char *name, int namelen)
 290 {
 291         int aliasoffset;
 292
 293         aliasoffset = fdt_path_offset(fdt, "/aliases");
 294         if (aliasoffset < 0)
 295                 return NULL;
 296
 297         return fdt_getprop_namelen(fdt, aliasoffset, name, namelen, NULL);
 298 }
 299
 300 const char *fdt_get_alias(const void *fdt, const char *name)
 301 {
 302         return fdt_get_alias_namelen(fdt, name, strlen(name));
 303 }
 304
 305 int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen)
 306 {
 307         int pdepth = 0, p = 0;
 308         int offset, depth, namelen;
 309         const char *name;
 310
 311         FDT_CHECK_HEADER(fdt);
 312
 313         if (buflen < 2)
 314                 return -FDT_ERR_NOSPACE;
 315
 316         for (offset = 0, depth = 0;
 317              (offset >= 0) && (offset <= nodeoffset);
 318              offset = fdt_next_node(fdt, offset, &depth)) {
 319                 while (pdepth > depth) {
 320                         do {
 321                                 p--;
 322                         } while (buf[p-1] != '/');
 323                         pdepth--;
 324                 }
 325
 326                 if (pdepth >= depth) {
 327                         name = fdt_get_name(fdt, offset, &namelen);
 328                         if (!name)
 329                                 return namelen;
 330                         if ((p + namelen + 1) <= buflen) {
 331                                 memcpy(buf + p, name, namelen);
 332                                 p += namelen;
 333                                 buf[p++] = '/';
 334                                 pdepth++;
 335                         }
 336                 }
 337
 338                 if (offset == nodeoffset) {
 339                         if (pdepth < (depth + 1))
 340                                 return -FDT_ERR_NOSPACE;
 341
 342                         if (p > 1) /* special case so that root path is "/", not "" */
 343                                 p--;
 344                         buf[p] = '\0';
 345                         return 0;
 346                 }
 347         }
 348
 349         if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
 350                 return -FDT_ERR_BADOFFSET;
 351         else if (offset == -FDT_ERR_BADOFFSET)
 352                 return -FDT_ERR_BADSTRUCTURE;
 353
 354         return offset; /* error from fdt_next_node() */
 355 }
 356
 357 int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
 358                                  int supernodedepth, int *nodedepth)
 359 {
 360         int offset, depth;
 361         int supernodeoffset = -FDT_ERR_INTERNAL;
 362
 363         FDT_CHECK_HEADER(fdt);
 364
 365         if (supernodedepth < 0)
 366                 return -FDT_ERR_NOTFOUND;
 367
 368         for (offset = 0, depth = 0;
 369              (offset >= 0) && (offset <= nodeoffset);
 370              offset = fdt_next_node(fdt, offset, &depth)) {
 371                 if (depth == supernodedepth)
 372                         supernodeoffset = offset;
 373
 374                 if (offset == nodeoffset) {
 375                         if (nodedepth)
 376                                 *nodedepth = depth;
 377
 378                         if (supernodedepth > depth)
 379                                 return -FDT_ERR_NOTFOUND;
 380                         else
 381                                 return supernodeoffset;
 382                 }
 383         }
 384
 385         if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
 386                 return -FDT_ERR_BADOFFSET;
 387         else if (offset == -FDT_ERR_BADOFFSET)
 388                 return -FDT_ERR_BADSTRUCTURE;
 389
 390         return offset; /* error from fdt_next_node() */
 391 }
 392
 393 int fdt_node_depth(const void *fdt, int nodeoffset)
 394 {
 395         int nodedepth;
 396         int err;
 397
 398         err = fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, &nodedepth);
 399         if (err)
 400                 return (err < 0) ? err : -FDT_ERR_INTERNAL;
 401         return nodedepth;
 402 }
 403
 404 int fdt_parent_offset(const void *fdt, int nodeoffset)
 405 {
 406         int nodedepth = fdt_node_depth(fdt, nodeoffset);
 407
 408         if (nodedepth < 0)
 409                 return nodedepth;
 410         return fdt_supernode_atdepth_offset(fdt, nodeoffset,
 411                                             nodedepth - 1, NULL);
 412 }
 413
 414 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
 415                                   const char *propname,
 416                                   const void *propval, int proplen)
 417 {
 418         int offset;
 419         const void *val;
 420         int len;
 421
 422         FDT_CHECK_HEADER(fdt);
 423
 424         /* FIXME: The algorithm here is pretty horrible: we scan each
 425          * property of a node in fdt_getprop(), then if that didn't
 426          * find what we want, we scan over them again making our way
 427          * to the next node.  Still it's the easiest to implement
 428          * approach; performance can come later. */
 429         for (offset = fdt_next_node(fdt, startoffset, NULL);
 430              offset >= 0;
 431              offset = fdt_next_node(fdt, offset, NULL)) {
 432                 val = fdt_getprop(fdt, offset, propname, &len);
 433                 if (val && (len == proplen)
 434                     && (memcmp(val, propval, len) == 0))
 435                         return offset;
 436         }
 437
 438         return offset; /* error from fdt_next_node() */
 439 }
 440
 441 int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle)
 442 {
 443         if ((phandle == 0) || (phandle == -1))
 444                 return -FDT_ERR_BADPHANDLE;
 445         phandle = cpu_to_fdt32(phandle);
 446         return fdt_node_offset_by_prop_value(fdt, -1, "linux,phandle",
 447                                              &phandle, sizeof(phandle));
 448 }
 449
 450 static int _fdt_stringlist_contains(const char *strlist, int listlen,
 451                                     const char *str)
 452 {
 453         int len = strlen(str);
 454         const char *p;
 455
 456         while (listlen >= len) {
 457                 if (memcmp(str, strlist, len+1) == 0)
 458                         return 1;
 459                 p = memchr(strlist, '\0', listlen);
 460                 if (!p)
 461                         return 0; /* malformed strlist.. */
 462                 listlen -= (p-strlist) + 1;
 463                 strlist = p + 1;
 464         }
 465         return 0;
 466 }
 467
 468 int fdt_node_check_compatible(const void *fdt, int nodeoffset,
 469                               const char *compatible)
 470 {
 471         const void *prop;
 472         int len;
 473
 474         prop = fdt_getprop(fdt, nodeoffset, "compatible", &len);
 475         if (!prop)
 476                 return len;
 477         if (_fdt_stringlist_contains(prop, len, compatible))
 478                 return 0;
 479         else
 480                 return 1;
 481 }
 482
 483 int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
 484                                   const char *compatible)
 485 {
 486         int offset, err;
 487
 488         FDT_CHECK_HEADER(fdt);
 489
 490         /* FIXME: The algorithm here is pretty horrible: we scan each
 491          * property of a node in fdt_node_check_compatible(), then if
 492          * that didn't find what we want, we scan over them again
 493          * making our way to the next node.  Still it's the easiest to
 494          * implement approach; performance can come later. */
 495         for (offset = fdt_next_node(fdt, startoffset, NULL);
 496              offset >= 0;
 497              offset = fdt_next_node(fdt, offset, NULL)) {
 498                 err = fdt_node_check_compatible(fdt, offset, compatible);
 499                 if ((err < 0) && (err != -FDT_ERR_NOTFOUND))
 500                         return err;
 501                 else if (err == 0)
 502                         return offset;
 503         }
 504
 505         return offset; /* error from fdt_next_node() */
 506 }