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