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 #include <fdt.h>
  54 #include <libfdt.h>
  55
  56 #include "libfdt_internal.h"
  57
  58 static int nodename_eq(const void *fdt, int offset,
  59                        const char *s, int len)
  60 {
  61         const char *p = fdt_offset_ptr(fdt, offset + FDT_TAGSIZE, len+1);
  62
  63         if (! p)
  64                 /* short match */
  65                 return 0;
  66
  67         if (memcmp(p, s, len) != 0)
  68                 return 0;
  69
  70         if (p[len] == '\0')
  71                 return 1;
  72         else if (!memchr(s, '@', len) && (p[len] == '@'))
  73                 return 1;
  74         else
  75                 return 0;
  76 }
  77
  78 const char *fdt_string(const void *fdt, int stroffset)
  79 {
  80         return (char *)fdt + fdt_off_dt_strings(fdt) + stroffset;
  81 }
  82
  83 int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size)
  84 {
  85         CHECK_HEADER(fdt);
  86         *address = fdt64_to_cpu(_fdt_mem_rsv(fdt, n)->address);
  87         *size = fdt64_to_cpu(_fdt_mem_rsv(fdt, n)->size);
  88         return 0;
  89 }
  90
  91 int fdt_num_mem_rsv(const void *fdt)
  92 {
  93         int i = 0;
  94
  95         while (fdt64_to_cpu(_fdt_mem_rsv(fdt, i)->size) != 0)
  96                 i++;
  97         return i;
  98 }
  99
 100 int fdt_subnode_offset_namelen(const void *fdt, int offset,
 101                                const char *name, int namelen)
 102 {
 103         int depth;
 104
 105         CHECK_HEADER(fdt);
 106
 107         for (depth = 0;
 108              offset >= 0;
 109              offset = fdt_next_node(fdt, offset, &depth)) {
 110                 if (depth < 0)
 111                         return -FDT_ERR_NOTFOUND;
 112                 else if ((depth == 1)
 113                          && nodename_eq(fdt, offset, name, namelen))
 114                         return offset;
 115         }
 116
 117         return offset; /* error */
 118 }
 119
 120 int fdt_subnode_offset(const void *fdt, int parentoffset,
 121                        const char *name)
 122 {
 123         return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name));
 124 }
 125
 126 int fdt_path_offset(const void *fdt, const char *path)
 127 {
 128         const char *end = path + strlen(path);
 129         const char *p = path;
 130         int offset = 0;
 131
 132         CHECK_HEADER(fdt);
 133
 134         if (*path != '/')
 135                 return -FDT_ERR_BADPATH;
 136
 137         while (*p) {
 138                 const char *q;
 139
 140                 while (*p == '/')
 141                         p++;
 142                 if (! *p)
 143                         return offset;
 144                 q = strchr(p, '/');
 145                 if (! q)
 146                         q = end;
 147
 148                 offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p);
 149                 if (offset < 0)
 150                         return offset;
 151
 152                 p = q;
 153         }
 154
 155         return offset;
 156 }
 157
 158 const char *fdt_get_name(const void *fdt, int nodeoffset, int *len)
 159 {
 160         const struct fdt_node_header *nh;
 161         int err;
 162
 163         if ((err = fdt_check_header(fdt)) != 0)
 164                 goto fail;
 165
 166         err = -FDT_ERR_BADOFFSET;
 167         nh = fdt_offset_ptr(fdt, nodeoffset, sizeof(*nh));
 168         if (!nh || (fdt32_to_cpu(nh->tag) != FDT_BEGIN_NODE))
 169                 goto fail;
 170
 171         if (len)
 172                 *len = strlen(nh->name);
 173
 174         return nh->name;
 175
 176  fail:
 177         if (len)
 178                 *len = err;
 179         return NULL;
 180 }
 181
 182 const struct fdt_property *fdt_get_property(const void *fdt,
 183                                             int nodeoffset,
 184                                             const char *name, int *lenp)
 185 {
 186         uint32_t tag;
 187         const struct fdt_property *prop;
 188         int namestroff;
 189         int offset, nextoffset;
 190         int err;
 191
 192         if ((err = fdt_check_header(fdt)) != 0)
 193                 goto fail;
 194
 195         err = -FDT_ERR_BADOFFSET;
 196         if (nodeoffset % FDT_TAGSIZE)
 197                 goto fail;
 198
 199         tag = fdt_next_tag(fdt, nodeoffset, &nextoffset);
 200         if (tag != FDT_BEGIN_NODE)
 201                 goto fail;
 202
 203         do {
 204                 offset = nextoffset;
 205
 206                 tag = fdt_next_tag(fdt, offset, &nextoffset);
 207                 switch (tag) {
 208                 case FDT_END:
 209                         err = -FDT_ERR_TRUNCATED;
 210                         goto fail;
 211
 212                 case FDT_BEGIN_NODE:
 213                 case FDT_END_NODE:
 214                 case FDT_NOP:
 215                         break;
 216
 217                 case FDT_PROP:
 218                         err = -FDT_ERR_BADSTRUCTURE;
 219                         prop = fdt_offset_ptr(fdt, offset, sizeof(*prop));
 220                         if (! prop)
 221                                 goto fail;
 222                         namestroff = fdt32_to_cpu(prop->nameoff);
 223                         if (streq(fdt_string(fdt, namestroff), name)) {
 224                                 /* Found it! */
 225                                 int len = fdt32_to_cpu(prop->len);
 226                                 prop = fdt_offset_ptr(fdt, offset,
 227                                                       sizeof(*prop)+len);
 228                                 if (! prop)
 229                                         goto fail;
 230
 231                                 if (lenp)
 232                                         *lenp = len;
 233
 234                                 return prop;
 235                         }
 236                         break;
 237
 238                 default:
 239                         err = -FDT_ERR_BADSTRUCTURE;
 240                         goto fail;
 241                 }
 242         } while ((tag != FDT_BEGIN_NODE) && (tag != FDT_END_NODE));
 243
 244         err = -FDT_ERR_NOTFOUND;
 245  fail:
 246         if (lenp)
 247                 *lenp = err;
 248         return NULL;
 249 }
 250
 251 const void *fdt_getprop(const void *fdt, int nodeoffset,
 252                   const char *name, int *lenp)
 253 {
 254         const struct fdt_property *prop;
 255
 256         prop = fdt_get_property(fdt, nodeoffset, name, lenp);
 257         if (! prop)
 258                 return NULL;
 259
 260         return prop->data;
 261 }
 262
 263 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
 264 {
 265         const uint32_t *php;
 266         int len;
 267
 268         php = fdt_getprop(fdt, nodeoffset, "linux,phandle", &len);
 269         if (!php || (len != sizeof(*php)))
 270                 return 0;
 271
 272         return fdt32_to_cpu(*php);
 273 }
 274
 275 int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen)
 276 {
 277         int pdepth = 0, p = 0;
 278         int offset, depth, namelen;
 279         const char *name;
 280
 281         CHECK_HEADER(fdt);
 282
 283         if (buflen < 2)
 284                 return -FDT_ERR_NOSPACE;
 285
 286         for (offset = 0, depth = 0;
 287              (offset >= 0) && (offset <= nodeoffset);
 288              offset = fdt_next_node(fdt, offset, &depth)) {
 289                 if (pdepth < depth)
 290                         continue; /* overflowed buffer */
 291
 292                 while (pdepth > depth) {
 293                         do {
 294                                 p--;
 295                         } while (buf[p-1] != '/');
 296                         pdepth--;
 297                 }
 298
 299                 name = fdt_get_name(fdt, offset, &namelen);
 300                 if (!name)
 301                         return namelen;
 302                 if ((p + namelen + 1) <= buflen) {
 303                         memcpy(buf + p, name, namelen);
 304                         p += namelen;
 305                         buf[p++] = '/';
 306                         pdepth++;
 307                 }
 308
 309                 if (offset == nodeoffset) {
 310                         if (pdepth < (depth + 1))
 311                                 return -FDT_ERR_NOSPACE;
 312
 313                         if (p > 1) /* special case so that root path is "/", not "" */
 314                                 p--;
 315                         buf[p] = '\0';
 316                         return p;
 317                 }
 318         }
 319
 320         if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
 321                 return -FDT_ERR_BADOFFSET;
 322         else if (offset == -FDT_ERR_BADOFFSET)
 323                 return -FDT_ERR_BADSTRUCTURE;
 324
 325         return offset; /* error from fdt_next_node() */
 326 }
 327
 328 int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
 329                                  int supernodedepth, int *nodedepth)
 330 {
 331         int offset, depth;
 332         int supernodeoffset = -FDT_ERR_INTERNAL;
 333
 334         CHECK_HEADER(fdt);
 335
 336         if (supernodedepth < 0)
 337                 return -FDT_ERR_NOTFOUND;
 338
 339         for (offset = 0, depth = 0;
 340              (offset >= 0) && (offset <= nodeoffset);
 341              offset = fdt_next_node(fdt, offset, &depth)) {
 342                 if (depth == supernodedepth)
 343                         supernodeoffset = offset;
 344
 345                 if (offset == nodeoffset) {
 346                         if (nodedepth)
 347                                 *nodedepth = depth;
 348
 349                         if (supernodedepth > depth)
 350                                 return -FDT_ERR_NOTFOUND;
 351                         else
 352                                 return supernodeoffset;
 353                 }
 354         }
 355
 356         if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
 357                 return -FDT_ERR_BADOFFSET;
 358         else if (offset == -FDT_ERR_BADOFFSET)
 359                 return -FDT_ERR_BADSTRUCTURE;
 360
 361         return offset; /* error from fdt_next_node() */
 362 }
 363
 364 int fdt_node_depth(const void *fdt, int nodeoffset)
 365 {
 366         int nodedepth;
 367         int err;
 368
 369         err = fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, &nodedepth);
 370         if (err)
 371                 return (err < 0) ? err : -FDT_ERR_INTERNAL;
 372         return nodedepth;
 373 }
 374
 375 int fdt_parent_offset(const void *fdt, int nodeoffset)
 376 {
 377         int nodedepth = fdt_node_depth(fdt, nodeoffset);
 378
 379         if (nodedepth < 0)
 380                 return nodedepth;
 381         return fdt_supernode_atdepth_offset(fdt, nodeoffset,
 382                                             nodedepth - 1, NULL);
 383 }
 384
 385 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
 386                                   const char *propname,
 387                                   const void *propval, int proplen)
 388 {
 389         int offset;
 390         const void *val;
 391         int len;
 392
 393         CHECK_HEADER(fdt);
 394
 395         /* FIXME: The algorithm here is pretty horrible: we scan each
 396          * property of a node in fdt_getprop(), then if that didn't
 397          * find what we want, we scan over them again making our way
 398          * to the next node.  Still it's the easiest to implement
 399          * approach; performance can come later. */
 400         for (offset = fdt_next_node(fdt, startoffset, NULL);
 401              offset >= 0;
 402              offset = fdt_next_node(fdt, offset, NULL)) {
 403                 val = fdt_getprop(fdt, offset, propname, &len);
 404                 if (val && (len == proplen)
 405                     && (memcmp(val, propval, len) == 0))
 406                         return offset;
 407         }
 408
 409         return offset; /* error from fdt_next_node() */
 410 }
 411
 412 int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle)
 413 {
 414         if ((phandle == 0) || (phandle == -1))
 415                 return -FDT_ERR_BADPHANDLE;
 416         phandle = cpu_to_fdt32(phandle);
 417         return fdt_node_offset_by_prop_value(fdt, -1, "linux,phandle",
 418                                              &phandle, sizeof(phandle));
 419 }
 420
 421 int _stringlist_contains(const void *strlist, int listlen, const char *str)
 422 {
 423         int len = strlen(str);
 424         const void *p;
 425
 426         while (listlen >= len) {
 427                 if (memcmp(str, strlist, len+1) == 0)
 428                         return 1;
 429                 p = memchr(strlist, '\0', listlen);
 430                 if (!p)
 431                         return 0; /* malformed strlist.. */
 432                 listlen -= (p-strlist) + 1;
 433                 strlist = p + 1;
 434         }
 435         return 0;
 436 }
 437
 438 int fdt_node_check_compatible(const void *fdt, int nodeoffset,
 439                               const char *compatible)
 440 {
 441         const void *prop;
 442         int len;
 443
 444         prop = fdt_getprop(fdt, nodeoffset, "compatible", &len);
 445         if (!prop)
 446                 return len;
 447         if (_stringlist_contains(prop, len, compatible))
 448                 return 0;
 449         else
 450                 return 1;
 451 }
 452
 453 int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
 454                                   const char *compatible)
 455 {
 456         int offset, err;
 457
 458         CHECK_HEADER(fdt);
 459
 460         /* FIXME: The algorithm here is pretty horrible: we scan each
 461          * property of a node in fdt_node_check_compatible(), then if
 462          * that didn't find what we want, we scan over them again
 463          * making our way to the next node.  Still it's the easiest to
 464          * implement approach; performance can come later. */
 465         for (offset = fdt_next_node(fdt, startoffset, NULL);
 466              offset >= 0;
 467              offset = fdt_next_node(fdt, offset, NULL)) {
 468                 err = fdt_node_check_compatible(fdt, offset, compatible);
 469                 if ((err < 0) && (err != -FDT_ERR_NOTFOUND))
 470                         return err;
 471                 else if (err == 0)
 472                         return offset;
 473         }
 474
 475         return offset; /* error from fdt_next_node() */
 476 }