uboot/include/libfdt.h
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   1#ifndef _LIBFDT_H
   2#define _LIBFDT_H
   3/*
   4 * libfdt - Flat Device Tree manipulation
   5 * Copyright (C) 2006 David Gibson, IBM Corporation.
   6 *
   7 * libfdt is dual licensed: you can use it either under the terms of
   8 * the GPL, or the BSD license, at your option.
   9 *
  10 *  a) This library is free software; you can redistribute it and/or
  11 *     modify it under the terms of the GNU General Public License as
  12 *     published by the Free Software Foundation; either version 2 of the
  13 *     License, or (at your option) any later version.
  14 *
  15 *     This library is distributed in the hope that it will be useful,
  16 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 *     GNU General Public License for more details.
  19 *
  20 *     You should have received a copy of the GNU General Public
  21 *     License along with this library; if not, write to the Free
  22 *     Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
  23 *     MA 02110-1301 USA
  24 *
  25 * Alternatively,
  26 *
  27 *  b) Redistribution and use in source and binary forms, with or
  28 *     without modification, are permitted provided that the following
  29 *     conditions are met:
  30 *
  31 *     1. Redistributions of source code must retain the above
  32 *        copyright notice, this list of conditions and the following
  33 *        disclaimer.
  34 *     2. Redistributions in binary form must reproduce the above
  35 *        copyright notice, this list of conditions and the following
  36 *        disclaimer in the documentation and/or other materials
  37 *        provided with the distribution.
  38 *
  39 *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
  40 *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
  41 *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  42 *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  43 *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  44 *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45 *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46 *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47 *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48 *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  49 *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  50 *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
  51 *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  52 */
  53
  54#include <libfdt_env.h>
  55#include <fdt.h>
  56
  57#define FDT_FIRST_SUPPORTED_VERSION     0x10
  58#define FDT_LAST_SUPPORTED_VERSION      0x11
  59
  60/* Error codes: informative error codes */
  61#define FDT_ERR_NOTFOUND        1
  62        /* FDT_ERR_NOTFOUND: The requested node or property does not exist */
  63#define FDT_ERR_EXISTS          2
  64        /* FDT_ERR_EXISTS: Attemped to create a node or property which
  65         * already exists */
  66#define FDT_ERR_NOSPACE         3
  67        /* FDT_ERR_NOSPACE: Operation needed to expand the device
  68         * tree, but its buffer did not have sufficient space to
  69         * contain the expanded tree. Use fdt_open_into() to move the
  70         * device tree to a buffer with more space. */
  71
  72/* Error codes: codes for bad parameters */
  73#define FDT_ERR_BADOFFSET       4
  74        /* FDT_ERR_BADOFFSET: Function was passed a structure block
  75         * offset which is out-of-bounds, or which points to an
  76         * unsuitable part of the structure for the operation. */
  77#define FDT_ERR_BADPATH         5
  78        /* FDT_ERR_BADPATH: Function was passed a badly formatted path
  79         * (e.g. missing a leading / for a function which requires an
  80         * absolute path) */
  81#define FDT_ERR_BADPHANDLE      6
  82        /* FDT_ERR_BADPHANDLE: Function was passed an invalid phandle
  83         * value.  phandle values of 0 and -1 are not permitted. */
  84#define FDT_ERR_BADSTATE        7
  85        /* FDT_ERR_BADSTATE: Function was passed an incomplete device
  86         * tree created by the sequential-write functions, which is
  87         * not sufficiently complete for the requested operation. */
  88
  89/* Error codes: codes for bad device tree blobs */
  90#define FDT_ERR_TRUNCATED       8
  91        /* FDT_ERR_TRUNCATED: Structure block of the given device tree
  92         * ends without an FDT_END tag. */
  93#define FDT_ERR_BADMAGIC        9
  94        /* FDT_ERR_BADMAGIC: Given "device tree" appears not to be a
  95         * device tree at all - it is missing the flattened device
  96         * tree magic number. */
  97#define FDT_ERR_BADVERSION      10
  98        /* FDT_ERR_BADVERSION: Given device tree has a version which
  99         * can't be handled by the requested operation.  For
 100         * read-write functions, this may mean that fdt_open_into() is
 101         * required to convert the tree to the expected version. */
 102#define FDT_ERR_BADSTRUCTURE    11
 103        /* FDT_ERR_BADSTRUCTURE: Given device tree has a corrupt
 104         * structure block or other serious error (e.g. misnested
 105         * nodes, or subnodes preceding properties). */
 106#define FDT_ERR_BADLAYOUT       12
 107        /* FDT_ERR_BADLAYOUT: For read-write functions, the given
 108         * device tree has it's sub-blocks in an order that the
 109         * function can't handle (memory reserve map, then structure,
 110         * then strings).  Use fdt_open_into() to reorganize the tree
 111         * into a form suitable for the read-write operations. */
 112
 113/* "Can't happen" error indicating a bug in libfdt */
 114#define FDT_ERR_INTERNAL        13
 115        /* FDT_ERR_INTERNAL: libfdt has failed an internal assertion.
 116         * Should never be returned, if it is, it indicates a bug in
 117         * libfdt itself. */
 118
 119/* Errors in device tree content */
 120#define FDT_ERR_BADNCELLS       14
 121        /* FDT_ERR_BADNCELLS: Device tree has a #address-cells, #size-cells
 122         * or similar property with a bad format or value */
 123
 124#define FDT_ERR_MAX             14
 125
 126/**********************************************************************/
 127/* Low-level functions (you probably don't need these)                */
 128/**********************************************************************/
 129
 130const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int checklen);
 131static inline void *fdt_offset_ptr_w(void *fdt, int offset, int checklen)
 132{
 133        return (void *)(uintptr_t)fdt_offset_ptr(fdt, offset, checklen);
 134}
 135
 136uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset);
 137
 138/**********************************************************************/
 139/* Traversal functions                                                */
 140/**********************************************************************/
 141
 142int fdt_next_node(const void *fdt, int offset, int *depth);
 143
 144/**
 145 * fdt_first_subnode() - get offset of first direct subnode
 146 *
 147 * @fdt:        FDT blob
 148 * @offset:     Offset of node to check
 149 * @return offset of first subnode, or -FDT_ERR_NOTFOUND if there is none
 150 */
 151int fdt_first_subnode(const void *fdt, int offset);
 152
 153/**
 154 * fdt_next_subnode() - get offset of next direct subnode
 155 *
 156 * After first calling fdt_first_subnode(), call this function repeatedly to
 157 * get direct subnodes of a parent node.
 158 *
 159 * @fdt:        FDT blob
 160 * @offset:     Offset of previous subnode
 161 * @return offset of next subnode, or -FDT_ERR_NOTFOUND if there are no more
 162 * subnodes
 163 */
 164int fdt_next_subnode(const void *fdt, int offset);
 165
 166/**
 167 * fdt_for_each_subnode - iterate over all subnodes of a parent
 168 *
 169 * This is actually a wrapper around a for loop and would be used like so:
 170 *
 171 *      fdt_for_each_subnode(fdt, node, parent) {
 172 *              ...
 173 *              use node
 174 *              ...
 175 *      }
 176 *
 177 * Note that this is implemented as a macro and node is used as iterator in
 178 * the loop. It should therefore be a locally allocated variable. The parent
 179 * variable on the other hand is never modified, so it can be constant or
 180 * even a literal.
 181 *
 182 * @fdt:        FDT blob (const void *)
 183 * @node:       child node (int)
 184 * @parent:     parent node (int)
 185 */
 186#define fdt_for_each_subnode(fdt, node, parent)         \
 187        for (node = fdt_first_subnode(fdt, parent);     \
 188             node >= 0;                                 \
 189             node = fdt_next_subnode(fdt, node))
 190
 191/**********************************************************************/
 192/* General functions                                                  */
 193/**********************************************************************/
 194
 195#define fdt_get_header(fdt, field) \
 196        (fdt32_to_cpu(((const struct fdt_header *)(fdt))->field))
 197#define fdt_magic(fdt)                  (fdt_get_header(fdt, magic))
 198#define fdt_totalsize(fdt)              (fdt_get_header(fdt, totalsize))
 199#define fdt_off_dt_struct(fdt)          (fdt_get_header(fdt, off_dt_struct))
 200#define fdt_off_dt_strings(fdt)         (fdt_get_header(fdt, off_dt_strings))
 201#define fdt_off_mem_rsvmap(fdt)         (fdt_get_header(fdt, off_mem_rsvmap))
 202#define fdt_version(fdt)                (fdt_get_header(fdt, version))
 203#define fdt_last_comp_version(fdt)      (fdt_get_header(fdt, last_comp_version))
 204#define fdt_boot_cpuid_phys(fdt)        (fdt_get_header(fdt, boot_cpuid_phys))
 205#define fdt_size_dt_strings(fdt)        (fdt_get_header(fdt, size_dt_strings))
 206#define fdt_size_dt_struct(fdt)         (fdt_get_header(fdt, size_dt_struct))
 207
 208#define __fdt_set_hdr(name) \
 209        static inline void fdt_set_##name(void *fdt, uint32_t val) \
 210        { \
 211                struct fdt_header *fdth = (struct fdt_header*)fdt; \
 212                fdth->name = cpu_to_fdt32(val); \
 213        }
 214__fdt_set_hdr(magic);
 215__fdt_set_hdr(totalsize);
 216__fdt_set_hdr(off_dt_struct);
 217__fdt_set_hdr(off_dt_strings);
 218__fdt_set_hdr(off_mem_rsvmap);
 219__fdt_set_hdr(version);
 220__fdt_set_hdr(last_comp_version);
 221__fdt_set_hdr(boot_cpuid_phys);
 222__fdt_set_hdr(size_dt_strings);
 223__fdt_set_hdr(size_dt_struct);
 224#undef __fdt_set_hdr
 225
 226/**
 227 * fdt_check_header - sanity check a device tree or possible device tree
 228 * @fdt: pointer to data which might be a flattened device tree
 229 *
 230 * fdt_check_header() checks that the given buffer contains what
 231 * appears to be a flattened device tree with sane information in its
 232 * header.
 233 *
 234 * returns:
 235 *     0, if the buffer appears to contain a valid device tree
 236 *     -FDT_ERR_BADMAGIC,
 237 *     -FDT_ERR_BADVERSION,
 238 *     -FDT_ERR_BADSTATE, standard meanings, as above
 239 */
 240int fdt_check_header(const void *fdt);
 241
 242/**
 243 * fdt_move - move a device tree around in memory
 244 * @fdt: pointer to the device tree to move
 245 * @buf: pointer to memory where the device is to be moved
 246 * @bufsize: size of the memory space at buf
 247 *
 248 * fdt_move() relocates, if possible, the device tree blob located at
 249 * fdt to the buffer at buf of size bufsize.  The buffer may overlap
 250 * with the existing device tree blob at fdt.  Therefore,
 251 *     fdt_move(fdt, fdt, fdt_totalsize(fdt))
 252 * should always succeed.
 253 *
 254 * returns:
 255 *     0, on success
 256 *     -FDT_ERR_NOSPACE, bufsize is insufficient to contain the device tree
 257 *     -FDT_ERR_BADMAGIC,
 258 *     -FDT_ERR_BADVERSION,
 259 *     -FDT_ERR_BADSTATE, standard meanings
 260 */
 261int fdt_move(const void *fdt, void *buf, int bufsize);
 262
 263/**********************************************************************/
 264/* Read-only functions                                                */
 265/**********************************************************************/
 266
 267/**
 268 * fdt_string - retrieve a string from the strings block of a device tree
 269 * @fdt: pointer to the device tree blob
 270 * @stroffset: offset of the string within the strings block (native endian)
 271 *
 272 * fdt_string() retrieves a pointer to a single string from the
 273 * strings block of the device tree blob at fdt.
 274 *
 275 * returns:
 276 *     a pointer to the string, on success
 277 *     NULL, if stroffset is out of bounds
 278 */
 279const char *fdt_string(const void *fdt, int stroffset);
 280
 281/**
 282 * fdt_num_mem_rsv - retrieve the number of memory reserve map entries
 283 * @fdt: pointer to the device tree blob
 284 *
 285 * Returns the number of entries in the device tree blob's memory
 286 * reservation map.  This does not include the terminating 0,0 entry
 287 * or any other (0,0) entries reserved for expansion.
 288 *
 289 * returns:
 290 *     the number of entries
 291 */
 292int fdt_num_mem_rsv(const void *fdt);
 293
 294/**
 295 * fdt_get_mem_rsv - retrieve one memory reserve map entry
 296 * @fdt: pointer to the device tree blob
 297 * @address, @size: pointers to 64-bit variables
 298 *
 299 * On success, *address and *size will contain the address and size of
 300 * the n-th reserve map entry from the device tree blob, in
 301 * native-endian format.
 302 *
 303 * returns:
 304 *     0, on success
 305 *     -FDT_ERR_BADMAGIC,
 306 *     -FDT_ERR_BADVERSION,
 307 *     -FDT_ERR_BADSTATE, standard meanings
 308 */
 309int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size);
 310
 311/**
 312 * fdt_subnode_offset_namelen - find a subnode based on substring
 313 * @fdt: pointer to the device tree blob
 314 * @parentoffset: structure block offset of a node
 315 * @name: name of the subnode to locate
 316 * @namelen: number of characters of name to consider
 317 *
 318 * Identical to fdt_subnode_offset(), but only examine the first
 319 * namelen characters of name for matching the subnode name.  This is
 320 * useful for finding subnodes based on a portion of a larger string,
 321 * such as a full path.
 322 */
 323int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
 324                               const char *name, int namelen);
 325/**
 326 * fdt_subnode_offset - find a subnode of a given node
 327 * @fdt: pointer to the device tree blob
 328 * @parentoffset: structure block offset of a node
 329 * @name: name of the subnode to locate
 330 *
 331 * fdt_subnode_offset() finds a subnode of the node at structure block
 332 * offset parentoffset with the given name.  name may include a unit
 333 * address, in which case fdt_subnode_offset() will find the subnode
 334 * with that unit address, or the unit address may be omitted, in
 335 * which case fdt_subnode_offset() will find an arbitrary subnode
 336 * whose name excluding unit address matches the given name.
 337 *
 338 * returns:
 339 *      structure block offset of the requested subnode (>=0), on success
 340 *      -FDT_ERR_NOTFOUND, if the requested subnode does not exist
 341 *      -FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag
 342 *      -FDT_ERR_BADMAGIC,
 343 *      -FDT_ERR_BADVERSION,
 344 *      -FDT_ERR_BADSTATE,
 345 *      -FDT_ERR_BADSTRUCTURE,
 346 *      -FDT_ERR_TRUNCATED, standard meanings.
 347 */
 348int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name);
 349
 350/**
 351 * fdt_path_offset - find a tree node by its full path
 352 * @fdt: pointer to the device tree blob
 353 * @path: full path of the node to locate
 354 *
 355 * fdt_path_offset() finds a node of a given path in the device tree.
 356 * Each path component may omit the unit address portion, but the
 357 * results of this are undefined if any such path component is
 358 * ambiguous (that is if there are multiple nodes at the relevant
 359 * level matching the given component, differentiated only by unit
 360 * address).
 361 *
 362 * returns:
 363 *      structure block offset of the node with the requested path (>=0), on success
 364 *      -FDT_ERR_BADPATH, given path does not begin with '/' or is invalid
 365 *      -FDT_ERR_NOTFOUND, if the requested node does not exist
 366 *      -FDT_ERR_BADMAGIC,
 367 *      -FDT_ERR_BADVERSION,
 368 *      -FDT_ERR_BADSTATE,
 369 *      -FDT_ERR_BADSTRUCTURE,
 370 *      -FDT_ERR_TRUNCATED, standard meanings.
 371 */
 372int fdt_path_offset(const void *fdt, const char *path);
 373
 374/**
 375 * fdt_get_name - retrieve the name of a given node
 376 * @fdt: pointer to the device tree blob
 377 * @nodeoffset: structure block offset of the starting node
 378 * @lenp: pointer to an integer variable (will be overwritten) or NULL
 379 *
 380 * fdt_get_name() retrieves the name (including unit address) of the
 381 * device tree node at structure block offset nodeoffset.  If lenp is
 382 * non-NULL, the length of this name is also returned, in the integer
 383 * pointed to by lenp.
 384 *
 385 * returns:
 386 *      pointer to the node's name, on success
 387 *              If lenp is non-NULL, *lenp contains the length of that name (>=0)
 388 *      NULL, on error
 389 *              if lenp is non-NULL *lenp contains an error code (<0):
 390 *              -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
 391 *              -FDT_ERR_BADMAGIC,
 392 *              -FDT_ERR_BADVERSION,
 393 *              -FDT_ERR_BADSTATE, standard meanings
 394 */
 395const char *fdt_get_name(const void *fdt, int nodeoffset, int *lenp);
 396
 397/**
 398 * fdt_first_property_offset - find the offset of a node's first property
 399 * @fdt: pointer to the device tree blob
 400 * @nodeoffset: structure block offset of a node
 401 *
 402 * fdt_first_property_offset() finds the first property of the node at
 403 * the given structure block offset.
 404 *
 405 * returns:
 406 *      structure block offset of the property (>=0), on success
 407 *      -FDT_ERR_NOTFOUND, if the requested node has no properties
 408 *      -FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_BEGIN_NODE tag
 409 *      -FDT_ERR_BADMAGIC,
 410 *      -FDT_ERR_BADVERSION,
 411 *      -FDT_ERR_BADSTATE,
 412 *      -FDT_ERR_BADSTRUCTURE,
 413 *      -FDT_ERR_TRUNCATED, standard meanings.
 414 */
 415int fdt_first_property_offset(const void *fdt, int nodeoffset);
 416
 417/**
 418 * fdt_next_property_offset - step through a node's properties
 419 * @fdt: pointer to the device tree blob
 420 * @offset: structure block offset of a property
 421 *
 422 * fdt_next_property_offset() finds the property immediately after the
 423 * one at the given structure block offset.  This will be a property
 424 * of the same node as the given property.
 425 *
 426 * returns:
 427 *      structure block offset of the next property (>=0), on success
 428 *      -FDT_ERR_NOTFOUND, if the given property is the last in its node
 429 *      -FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_PROP tag
 430 *      -FDT_ERR_BADMAGIC,
 431 *      -FDT_ERR_BADVERSION,
 432 *      -FDT_ERR_BADSTATE,
 433 *      -FDT_ERR_BADSTRUCTURE,
 434 *      -FDT_ERR_TRUNCATED, standard meanings.
 435 */
 436int fdt_next_property_offset(const void *fdt, int offset);
 437
 438/**
 439 * fdt_get_property_by_offset - retrieve the property at a given offset
 440 * @fdt: pointer to the device tree blob
 441 * @offset: offset of the property to retrieve
 442 * @lenp: pointer to an integer variable (will be overwritten) or NULL
 443 *
 444 * fdt_get_property_by_offset() retrieves a pointer to the
 445 * fdt_property structure within the device tree blob at the given
 446 * offset.  If lenp is non-NULL, the length of the property value is
 447 * also returned, in the integer pointed to by lenp.
 448 *
 449 * returns:
 450 *      pointer to the structure representing the property
 451 *              if lenp is non-NULL, *lenp contains the length of the property
 452 *              value (>=0)
 453 *      NULL, on error
 454 *              if lenp is non-NULL, *lenp contains an error code (<0):
 455 *              -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
 456 *              -FDT_ERR_BADMAGIC,
 457 *              -FDT_ERR_BADVERSION,
 458 *              -FDT_ERR_BADSTATE,
 459 *              -FDT_ERR_BADSTRUCTURE,
 460 *              -FDT_ERR_TRUNCATED, standard meanings
 461 */
 462const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
 463                                                      int offset,
 464                                                      int *lenp);
 465
 466/**
 467 * fdt_get_property_namelen - find a property based on substring
 468 * @fdt: pointer to the device tree blob
 469 * @nodeoffset: offset of the node whose property to find
 470 * @name: name of the property to find
 471 * @namelen: number of characters of name to consider
 472 * @lenp: pointer to an integer variable (will be overwritten) or NULL
 473 *
 474 * Identical to fdt_get_property_namelen(), but only examine the first
 475 * namelen characters of name for matching the property name.
 476 */
 477const struct fdt_property *fdt_get_property_namelen(const void *fdt,
 478                                                    int nodeoffset,
 479                                                    const char *name,
 480                                                    int namelen, int *lenp);
 481
 482/**
 483 * fdt_get_property - find a given property in a given node
 484 * @fdt: pointer to the device tree blob
 485 * @nodeoffset: offset of the node whose property to find
 486 * @name: name of the property to find
 487 * @lenp: pointer to an integer variable (will be overwritten) or NULL
 488 *
 489 * fdt_get_property() retrieves a pointer to the fdt_property
 490 * structure within the device tree blob corresponding to the property
 491 * named 'name' of the node at offset nodeoffset.  If lenp is
 492 * non-NULL, the length of the property value is also returned, in the
 493 * integer pointed to by lenp.
 494 *
 495 * returns:
 496 *      pointer to the structure representing the property
 497 *              if lenp is non-NULL, *lenp contains the length of the property
 498 *              value (>=0)
 499 *      NULL, on error
 500 *              if lenp is non-NULL, *lenp contains an error code (<0):
 501 *              -FDT_ERR_NOTFOUND, node does not have named property
 502 *              -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
 503 *              -FDT_ERR_BADMAGIC,
 504 *              -FDT_ERR_BADVERSION,
 505 *              -FDT_ERR_BADSTATE,
 506 *              -FDT_ERR_BADSTRUCTURE,
 507 *              -FDT_ERR_TRUNCATED, standard meanings
 508 */
 509const struct fdt_property *fdt_get_property(const void *fdt, int nodeoffset,
 510                                            const char *name, int *lenp);
 511static inline struct fdt_property *fdt_get_property_w(void *fdt, int nodeoffset,
 512                                                      const char *name,
 513                                                      int *lenp)
 514{
 515        return (struct fdt_property *)(uintptr_t)
 516                fdt_get_property(fdt, nodeoffset, name, lenp);
 517}
 518
 519/**
 520 * fdt_getprop_by_offset - retrieve the value of a property at a given offset
 521 * @fdt: pointer to the device tree blob
 522 * @ffset: offset of the property to read
 523 * @namep: pointer to a string variable (will be overwritten) or NULL
 524 * @lenp: pointer to an integer variable (will be overwritten) or NULL
 525 *
 526 * fdt_getprop_by_offset() retrieves a pointer to the value of the
 527 * property at structure block offset 'offset' (this will be a pointer
 528 * to within the device blob itself, not a copy of the value).  If
 529 * lenp is non-NULL, the length of the property value is also
 530 * returned, in the integer pointed to by lenp.  If namep is non-NULL,
 531 * the property's namne will also be returned in the char * pointed to
 532 * by namep (this will be a pointer to within the device tree's string
 533 * block, not a new copy of the name).
 534 *
 535 * returns:
 536 *      pointer to the property's value
 537 *              if lenp is non-NULL, *lenp contains the length of the property
 538 *              value (>=0)
 539 *              if namep is non-NULL *namep contiains a pointer to the property
 540 *              name.
 541 *      NULL, on error
 542 *              if lenp is non-NULL, *lenp contains an error code (<0):
 543 *              -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
 544 *              -FDT_ERR_BADMAGIC,
 545 *              -FDT_ERR_BADVERSION,
 546 *              -FDT_ERR_BADSTATE,
 547 *              -FDT_ERR_BADSTRUCTURE,
 548 *              -FDT_ERR_TRUNCATED, standard meanings
 549 */
 550const void *fdt_getprop_by_offset(const void *fdt, int offset,
 551                                  const char **namep, int *lenp);
 552
 553/**
 554 * fdt_getprop_namelen - get property value based on substring
 555 * @fdt: pointer to the device tree blob
 556 * @nodeoffset: offset of the node whose property to find
 557 * @name: name of the property to find
 558 * @namelen: number of characters of name to consider
 559 * @lenp: pointer to an integer variable (will be overwritten) or NULL
 560 *
 561 * Identical to fdt_getprop(), but only examine the first namelen
 562 * characters of name for matching the property name.
 563 */
 564const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
 565                                const char *name, int namelen, int *lenp);
 566
 567/**
 568 * fdt_getprop - retrieve the value of a given property
 569 * @fdt: pointer to the device tree blob
 570 * @nodeoffset: offset of the node whose property to find
 571 * @name: name of the property to find
 572 * @lenp: pointer to an integer variable (will be overwritten) or NULL
 573 *
 574 * fdt_getprop() retrieves a pointer to the value of the property
 575 * named 'name' of the node at offset nodeoffset (this will be a
 576 * pointer to within the device blob itself, not a copy of the value).
 577 * If lenp is non-NULL, the length of the property value is also
 578 * returned, in the integer pointed to by lenp.
 579 *
 580 * returns:
 581 *      pointer to the property's value
 582 *              if lenp is non-NULL, *lenp contains the length of the property
 583 *              value (>=0)
 584 *      NULL, on error
 585 *              if lenp is non-NULL, *lenp contains an error code (<0):
 586 *              -FDT_ERR_NOTFOUND, node does not have named property
 587 *              -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
 588 *              -FDT_ERR_BADMAGIC,
 589 *              -FDT_ERR_BADVERSION,
 590 *              -FDT_ERR_BADSTATE,
 591 *              -FDT_ERR_BADSTRUCTURE,
 592 *              -FDT_ERR_TRUNCATED, standard meanings
 593 */
 594const void *fdt_getprop(const void *fdt, int nodeoffset,
 595                        const char *name, int *lenp);
 596static inline void *fdt_getprop_w(void *fdt, int nodeoffset,
 597                                  const char *name, int *lenp)
 598{
 599        return (void *)(uintptr_t)fdt_getprop(fdt, nodeoffset, name, lenp);
 600}
 601
 602/**
 603 * fdt_get_phandle - retrieve the phandle of a given node
 604 * @fdt: pointer to the device tree blob
 605 * @nodeoffset: structure block offset of the node
 606 *
 607 * fdt_get_phandle() retrieves the phandle of the device tree node at
 608 * structure block offset nodeoffset.
 609 *
 610 * returns:
 611 *      the phandle of the node at nodeoffset, on success (!= 0, != -1)
 612 *      0, if the node has no phandle, or another error occurs
 613 */
 614uint32_t fdt_get_phandle(const void *fdt, int nodeoffset);
 615
 616/**
 617 * fdt_get_alias_namelen - get alias based on substring
 618 * @fdt: pointer to the device tree blob
 619 * @name: name of the alias th look up
 620 * @namelen: number of characters of name to consider
 621 *
 622 * Identical to fdt_get_alias(), but only examine the first namelen
 623 * characters of name for matching the alias name.
 624 */
 625const char *fdt_get_alias_namelen(const void *fdt,
 626                                  const char *name, int namelen);
 627
 628/**
 629 * fdt_get_alias - retreive the path referenced by a given alias
 630 * @fdt: pointer to the device tree blob
 631 * @name: name of the alias th look up
 632 *
 633 * fdt_get_alias() retrieves the value of a given alias.  That is, the
 634 * value of the property named 'name' in the node /aliases.
 635 *
 636 * returns:
 637 *      a pointer to the expansion of the alias named 'name', if it exists
 638 *      NULL, if the given alias or the /aliases node does not exist
 639 */
 640const char *fdt_get_alias(const void *fdt, const char *name);
 641
 642/**
 643 * fdt_get_path - determine the full path of a node
 644 * @fdt: pointer to the device tree blob
 645 * @nodeoffset: offset of the node whose path to find
 646 * @buf: character buffer to contain the returned path (will be overwritten)
 647 * @buflen: size of the character buffer at buf
 648 *
 649 * fdt_get_path() computes the full path of the node at offset
 650 * nodeoffset, and records that path in the buffer at buf.
 651 *
 652 * NOTE: This function is expensive, as it must scan the device tree
 653 * structure from the start to nodeoffset.
 654 *
 655 * returns:
 656 *      0, on success
 657 *              buf contains the absolute path of the node at
 658 *              nodeoffset, as a NUL-terminated string.
 659 *      -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 660 *      -FDT_ERR_NOSPACE, the path of the given node is longer than (bufsize-1)
 661 *              characters and will not fit in the given buffer.
 662 *      -FDT_ERR_BADMAGIC,
 663 *      -FDT_ERR_BADVERSION,
 664 *      -FDT_ERR_BADSTATE,
 665 *      -FDT_ERR_BADSTRUCTURE, standard meanings
 666 */
 667int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen);
 668
 669/**
 670 * fdt_supernode_atdepth_offset - find a specific ancestor of a node
 671 * @fdt: pointer to the device tree blob
 672 * @nodeoffset: offset of the node whose parent to find
 673 * @supernodedepth: depth of the ancestor to find
 674 * @nodedepth: pointer to an integer variable (will be overwritten) or NULL
 675 *
 676 * fdt_supernode_atdepth_offset() finds an ancestor of the given node
 677 * at a specific depth from the root (where the root itself has depth
 678 * 0, its immediate subnodes depth 1 and so forth).  So
 679 *      fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, NULL);
 680 * will always return 0, the offset of the root node.  If the node at
 681 * nodeoffset has depth D, then:
 682 *      fdt_supernode_atdepth_offset(fdt, nodeoffset, D, NULL);
 683 * will return nodeoffset itself.
 684 *
 685 * NOTE: This function is expensive, as it must scan the device tree
 686 * structure from the start to nodeoffset.
 687 *
 688 * returns:
 689
 690 *      structure block offset of the node at node offset's ancestor
 691 *              of depth supernodedepth (>=0), on success
 692 *      -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 693*       -FDT_ERR_NOTFOUND, supernodedepth was greater than the depth of nodeoffset
 694 *      -FDT_ERR_BADMAGIC,
 695 *      -FDT_ERR_BADVERSION,
 696 *      -FDT_ERR_BADSTATE,
 697 *      -FDT_ERR_BADSTRUCTURE, standard meanings
 698 */
 699int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
 700                                 int supernodedepth, int *nodedepth);
 701
 702/**
 703 * fdt_node_depth - find the depth of a given node
 704 * @fdt: pointer to the device tree blob
 705 * @nodeoffset: offset of the node whose parent to find
 706 *
 707 * fdt_node_depth() finds the depth of a given node.  The root node
 708 * has depth 0, its immediate subnodes depth 1 and so forth.
 709 *
 710 * NOTE: This function is expensive, as it must scan the device tree
 711 * structure from the start to nodeoffset.
 712 *
 713 * returns:
 714 *      depth of the node at nodeoffset (>=0), on success
 715 *      -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 716 *      -FDT_ERR_BADMAGIC,
 717 *      -FDT_ERR_BADVERSION,
 718 *      -FDT_ERR_BADSTATE,
 719 *      -FDT_ERR_BADSTRUCTURE, standard meanings
 720 */
 721int fdt_node_depth(const void *fdt, int nodeoffset);
 722
 723/**
 724 * fdt_parent_offset - find the parent of a given node
 725 * @fdt: pointer to the device tree blob
 726 * @nodeoffset: offset of the node whose parent to find
 727 *
 728 * fdt_parent_offset() locates the parent node of a given node (that
 729 * is, it finds the offset of the node which contains the node at
 730 * nodeoffset as a subnode).
 731 *
 732 * NOTE: This function is expensive, as it must scan the device tree
 733 * structure from the start to nodeoffset, *twice*.
 734 *
 735 * returns:
 736 *      structure block offset of the parent of the node at nodeoffset
 737 *              (>=0), on success
 738 *      -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 739 *      -FDT_ERR_BADMAGIC,
 740 *      -FDT_ERR_BADVERSION,
 741 *      -FDT_ERR_BADSTATE,
 742 *      -FDT_ERR_BADSTRUCTURE, standard meanings
 743 */
 744int fdt_parent_offset(const void *fdt, int nodeoffset);
 745
 746/**
 747 * fdt_node_offset_by_prop_value - find nodes with a given property value
 748 * @fdt: pointer to the device tree blob
 749 * @startoffset: only find nodes after this offset
 750 * @propname: property name to check
 751 * @propval: property value to search for
 752 * @proplen: length of the value in propval
 753 *
 754 * fdt_node_offset_by_prop_value() returns the offset of the first
 755 * node after startoffset, which has a property named propname whose
 756 * value is of length proplen and has value equal to propval; or if
 757 * startoffset is -1, the very first such node in the tree.
 758 *
 759 * To iterate through all nodes matching the criterion, the following
 760 * idiom can be used:
 761 *      offset = fdt_node_offset_by_prop_value(fdt, -1, propname,
 762 *                                             propval, proplen);
 763 *      while (offset != -FDT_ERR_NOTFOUND) {
 764 *              // other code here
 765 *              offset = fdt_node_offset_by_prop_value(fdt, offset, propname,
 766 *                                                     propval, proplen);
 767 *      }
 768 *
 769 * Note the -1 in the first call to the function, if 0 is used here
 770 * instead, the function will never locate the root node, even if it
 771 * matches the criterion.
 772 *
 773 * returns:
 774 *      structure block offset of the located node (>= 0, >startoffset),
 775 *               on success
 776 *      -FDT_ERR_NOTFOUND, no node matching the criterion exists in the
 777 *              tree after startoffset
 778 *      -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 779 *      -FDT_ERR_BADMAGIC,
 780 *      -FDT_ERR_BADVERSION,
 781 *      -FDT_ERR_BADSTATE,
 782 *      -FDT_ERR_BADSTRUCTURE, standard meanings
 783 */
 784int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
 785                                  const char *propname,
 786                                  const void *propval, int proplen);
 787
 788/**
 789 * fdt_node_offset_by_phandle - find the node with a given phandle
 790 * @fdt: pointer to the device tree blob
 791 * @phandle: phandle value
 792 *
 793 * fdt_node_offset_by_phandle() returns the offset of the node
 794 * which has the given phandle value.  If there is more than one node
 795 * in the tree with the given phandle (an invalid tree), results are
 796 * undefined.
 797 *
 798 * returns:
 799 *      structure block offset of the located node (>= 0), on success
 800 *      -FDT_ERR_NOTFOUND, no node with that phandle exists
 801 *      -FDT_ERR_BADPHANDLE, given phandle value was invalid (0 or -1)
 802 *      -FDT_ERR_BADMAGIC,
 803 *      -FDT_ERR_BADVERSION,
 804 *      -FDT_ERR_BADSTATE,
 805 *      -FDT_ERR_BADSTRUCTURE, standard meanings
 806 */
 807int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle);
 808
 809/**
 810 * fdt_node_check_compatible: check a node's compatible property
 811 * @fdt: pointer to the device tree blob
 812 * @nodeoffset: offset of a tree node
 813 * @compatible: string to match against
 814 *
 815 *
 816 * fdt_node_check_compatible() returns 0 if the given node contains a
 817 * 'compatible' property with the given string as one of its elements,
 818 * it returns non-zero otherwise, or on error.
 819 *
 820 * returns:
 821 *      0, if the node has a 'compatible' property listing the given string
 822 *      1, if the node has a 'compatible' property, but it does not list
 823 *              the given string
 824 *      -FDT_ERR_NOTFOUND, if the given node has no 'compatible' property
 825 *      -FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag
 826 *      -FDT_ERR_BADMAGIC,
 827 *      -FDT_ERR_BADVERSION,
 828 *      -FDT_ERR_BADSTATE,
 829 *      -FDT_ERR_BADSTRUCTURE, standard meanings
 830 */
 831int fdt_node_check_compatible(const void *fdt, int nodeoffset,
 832                              const char *compatible);
 833
 834/**
 835 * fdt_node_offset_by_compatible - find nodes with a given 'compatible' value
 836 * @fdt: pointer to the device tree blob
 837 * @startoffset: only find nodes after this offset
 838 * @compatible: 'compatible' string to match against
 839 *
 840 * fdt_node_offset_by_compatible() returns the offset of the first
 841 * node after startoffset, which has a 'compatible' property which
 842 * lists the given compatible string; or if startoffset is -1, the
 843 * very first such node in the tree.
 844 *
 845 * To iterate through all nodes matching the criterion, the following
 846 * idiom can be used:
 847 *      offset = fdt_node_offset_by_compatible(fdt, -1, compatible);
 848 *      while (offset != -FDT_ERR_NOTFOUND) {
 849 *              // other code here
 850 *              offset = fdt_node_offset_by_compatible(fdt, offset, compatible);
 851 *      }
 852 *
 853 * Note the -1 in the first call to the function, if 0 is used here
 854 * instead, the function will never locate the root node, even if it
 855 * matches the criterion.
 856 *
 857 * returns:
 858 *      structure block offset of the located node (>= 0, >startoffset),
 859 *               on success
 860 *      -FDT_ERR_NOTFOUND, no node matching the criterion exists in the
 861 *              tree after startoffset
 862 *      -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 863 *      -FDT_ERR_BADMAGIC,
 864 *      -FDT_ERR_BADVERSION,
 865 *      -FDT_ERR_BADSTATE,
 866 *      -FDT_ERR_BADSTRUCTURE, standard meanings
 867 */
 868int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
 869                                  const char *compatible);
 870
 871/**
 872 * fdt_stringlist_contains - check a string list property for a string
 873 * @strlist: Property containing a list of strings to check
 874 * @listlen: Length of property
 875 * @str: String to search for
 876 *
 877 * This is a utility function provided for convenience. The list contains
 878 * one or more strings, each terminated by \0, as is found in a device tree
 879 * "compatible" property.
 880 *
 881 * @return: 1 if the string is found in the list, 0 not found, or invalid list
 882 */
 883int fdt_stringlist_contains(const char *strlist, int listlen, const char *str);
 884
 885/**
 886 * fdt_count_strings - count the number of strings in a string list
 887 * @fdt: pointer to the device tree blob
 888 * @node: offset of the node
 889 * @property: name of the property containing the string list
 890 * @return: the number of strings in the given property
 891 */
 892int fdt_count_strings(const void *fdt, int node, const char *property);
 893
 894/**
 895 * fdt_find_string - find a string in a string list and return its index
 896 * @fdt: pointer to the device tree blob
 897 * @node: offset of the node
 898 * @property: name of the property containing the string list
 899 * @string: string to look up in the string list
 900 * @return: the index of the string or negative on error
 901 */
 902int fdt_find_string(const void *fdt, int node, const char *property,
 903                    const char *string);
 904
 905/**
 906 * fdt_get_string_index() - obtain the string at a given index in a string list
 907 * @fdt: pointer to the device tree blob
 908 * @node: offset of the node
 909 * @property: name of the property containing the string list
 910 * @index: index of the string to return
 911 * @output: return location for the string
 912 * @return: 0 if the string was found or a negative error code otherwise
 913 */
 914int fdt_get_string_index(const void *fdt, int node, const char *property,
 915                         int index, const char **output);
 916
 917/**
 918 * fdt_get_string() - obtain the string at a given index in a string list
 919 * @fdt: pointer to the device tree blob
 920 * @node: offset of the node
 921 * @property: name of the property containing the string list
 922 * @output: return location for the string
 923 * @return: 0 if the string was found or a negative error code otherwise
 924 *
 925 * This is a shortcut for:
 926 *
 927 *      fdt_get_string_index(fdt, node, property, 0, output).
 928 */
 929int fdt_get_string(const void *fdt, int node, const char *property,
 930                   const char **output);
 931
 932/**********************************************************************/
 933/* Read-only functions (addressing related)                           */
 934/**********************************************************************/
 935
 936/**
 937 * FDT_MAX_NCELLS - maximum value for #address-cells and #size-cells
 938 *
 939 * This is the maximum value for #address-cells, #size-cells and
 940 * similar properties that will be processed by libfdt.  IEE1275
 941 * requires that OF implementations handle values up to 4.
 942 * Implementations may support larger values, but in practice higher
 943 * values aren't used.
 944 */
 945#define FDT_MAX_NCELLS          4
 946
 947/**
 948 * fdt_address_cells - retrieve address size for a bus represented in the tree
 949 * @fdt: pointer to the device tree blob
 950 * @nodeoffset: offset of the node to find the address size for
 951 *
 952 * When the node has a valid #address-cells property, returns its value.
 953 *
 954 * returns:
 955 *      0 <= n < FDT_MAX_NCELLS, on success
 956 *      2, if the node has no #address-cells property
 957 *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
 958 *              #address-cells property
 959 *      -FDT_ERR_BADMAGIC,
 960 *      -FDT_ERR_BADVERSION,
 961 *      -FDT_ERR_BADSTATE,
 962 *      -FDT_ERR_BADSTRUCTURE,
 963 *      -FDT_ERR_TRUNCATED, standard meanings
 964 */
 965int fdt_address_cells(const void *fdt, int nodeoffset);
 966
 967/**
 968 * fdt_size_cells - retrieve address range size for a bus represented in the
 969 *                  tree
 970 * @fdt: pointer to the device tree blob
 971 * @nodeoffset: offset of the node to find the address range size for
 972 *
 973 * When the node has a valid #size-cells property, returns its value.
 974 *
 975 * returns:
 976 *      0 <= n < FDT_MAX_NCELLS, on success
 977 *      2, if the node has no #address-cells property
 978 *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
 979 *              #size-cells property
 980 *      -FDT_ERR_BADMAGIC,
 981 *      -FDT_ERR_BADVERSION,
 982 *      -FDT_ERR_BADSTATE,
 983 *      -FDT_ERR_BADSTRUCTURE,
 984 *      -FDT_ERR_TRUNCATED, standard meanings
 985 */
 986int fdt_size_cells(const void *fdt, int nodeoffset);
 987
 988
 989/**********************************************************************/
 990/* Write-in-place functions                                           */
 991/**********************************************************************/
 992
 993/**
 994 * fdt_setprop_inplace - change a property's value, but not its size
 995 * @fdt: pointer to the device tree blob
 996 * @nodeoffset: offset of the node whose property to change
 997 * @name: name of the property to change
 998 * @val: pointer to data to replace the property value with
 999 * @len: length of the property value
1000 *
1001 * fdt_setprop_inplace() replaces the value of a given property with
1002 * the data in val, of length len.  This function cannot change the
1003 * size of a property, and so will only work if len is equal to the
1004 * current length of the property.
1005 *
1006 * This function will alter only the bytes in the blob which contain
1007 * the given property value, and will not alter or move any other part
1008 * of the tree.
1009 *
1010 * returns:
1011 *      0, on success
1012 *      -FDT_ERR_NOSPACE, if len is not equal to the property's current length
1013 *      -FDT_ERR_NOTFOUND, node does not have the named property
1014 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1015 *      -FDT_ERR_BADMAGIC,
1016 *      -FDT_ERR_BADVERSION,
1017 *      -FDT_ERR_BADSTATE,
1018 *      -FDT_ERR_BADSTRUCTURE,
1019 *      -FDT_ERR_TRUNCATED, standard meanings
1020 */
1021int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
1022                        const void *val, int len);
1023
1024/**
1025 * fdt_setprop_inplace_u32 - change the value of a 32-bit integer property
1026 * @fdt: pointer to the device tree blob
1027 * @nodeoffset: offset of the node whose property to change
1028 * @name: name of the property to change
1029 * @val: 32-bit integer value to replace the property with
1030 *
1031 * fdt_setprop_inplace_u32() replaces the value of a given property
1032 * with the 32-bit integer value in val, converting val to big-endian
1033 * if necessary.  This function cannot change the size of a property,
1034 * and so will only work if the property already exists and has length
1035 * 4.
1036 *
1037 * This function will alter only the bytes in the blob which contain
1038 * the given property value, and will not alter or move any other part
1039 * of the tree.
1040 *
1041 * returns:
1042 *      0, on success
1043 *      -FDT_ERR_NOSPACE, if the property's length is not equal to 4
1044 *      -FDT_ERR_NOTFOUND, node does not have the named property
1045 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1046 *      -FDT_ERR_BADMAGIC,
1047 *      -FDT_ERR_BADVERSION,
1048 *      -FDT_ERR_BADSTATE,
1049 *      -FDT_ERR_BADSTRUCTURE,
1050 *      -FDT_ERR_TRUNCATED, standard meanings
1051 */
1052static inline int fdt_setprop_inplace_u32(void *fdt, int nodeoffset,
1053                                          const char *name, uint32_t val)
1054{
1055        fdt32_t tmp = cpu_to_fdt32(val);
1056        return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1057}
1058
1059/**
1060 * fdt_setprop_inplace_u64 - change the value of a 64-bit integer property
1061 * @fdt: pointer to the device tree blob
1062 * @nodeoffset: offset of the node whose property to change
1063 * @name: name of the property to change
1064 * @val: 64-bit integer value to replace the property with
1065 *
1066 * fdt_setprop_inplace_u64() replaces the value of a given property
1067 * with the 64-bit integer value in val, converting val to big-endian
1068 * if necessary.  This function cannot change the size of a property,
1069 * and so will only work if the property already exists and has length
1070 * 8.
1071 *
1072 * This function will alter only the bytes in the blob which contain
1073 * the given property value, and will not alter or move any other part
1074 * of the tree.
1075 *
1076 * returns:
1077 *      0, on success
1078 *      -FDT_ERR_NOSPACE, if the property's length is not equal to 8
1079 *      -FDT_ERR_NOTFOUND, node does not have the named property
1080 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1081 *      -FDT_ERR_BADMAGIC,
1082 *      -FDT_ERR_BADVERSION,
1083 *      -FDT_ERR_BADSTATE,
1084 *      -FDT_ERR_BADSTRUCTURE,
1085 *      -FDT_ERR_TRUNCATED, standard meanings
1086 */
1087static inline int fdt_setprop_inplace_u64(void *fdt, int nodeoffset,
1088                                          const char *name, uint64_t val)
1089{
1090        fdt64_t tmp = cpu_to_fdt64(val);
1091        return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1092}
1093
1094/**
1095 * fdt_setprop_inplace_cell - change the value of a single-cell property
1096 *
1097 * This is an alternative name for fdt_setprop_inplace_u32()
1098 */
1099static inline int fdt_setprop_inplace_cell(void *fdt, int nodeoffset,
1100                                           const char *name, uint32_t val)
1101{
1102        return fdt_setprop_inplace_u32(fdt, nodeoffset, name, val);
1103}
1104
1105/**
1106 * fdt_nop_property - replace a property with nop tags
1107 * @fdt: pointer to the device tree blob
1108 * @nodeoffset: offset of the node whose property to nop
1109 * @name: name of the property to nop
1110 *
1111 * fdt_nop_property() will replace a given property's representation
1112 * in the blob with FDT_NOP tags, effectively removing it from the
1113 * tree.
1114 *
1115 * This function will alter only the bytes in the blob which contain
1116 * the property, and will not alter or move any other part of the
1117 * tree.
1118 *
1119 * returns:
1120 *      0, on success
1121 *      -FDT_ERR_NOTFOUND, node does not have the named property
1122 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1123 *      -FDT_ERR_BADMAGIC,
1124 *      -FDT_ERR_BADVERSION,
1125 *      -FDT_ERR_BADSTATE,
1126 *      -FDT_ERR_BADSTRUCTURE,
1127 *      -FDT_ERR_TRUNCATED, standard meanings
1128 */
1129int fdt_nop_property(void *fdt, int nodeoffset, const char *name);
1130
1131/**
1132 * fdt_nop_node - replace a node (subtree) with nop tags
1133 * @fdt: pointer to the device tree blob
1134 * @nodeoffset: offset of the node to nop
1135 *
1136 * fdt_nop_node() will replace a given node's representation in the
1137 * blob, including all its subnodes, if any, with FDT_NOP tags,
1138 * effectively removing it from the tree.
1139 *
1140 * This function will alter only the bytes in the blob which contain
1141 * the node and its properties and subnodes, and will not alter or
1142 * move any other part of the tree.
1143 *
1144 * returns:
1145 *      0, on success
1146 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1147 *      -FDT_ERR_BADMAGIC,
1148 *      -FDT_ERR_BADVERSION,
1149 *      -FDT_ERR_BADSTATE,
1150 *      -FDT_ERR_BADSTRUCTURE,
1151 *      -FDT_ERR_TRUNCATED, standard meanings
1152 */
1153int fdt_nop_node(void *fdt, int nodeoffset);
1154
1155/**********************************************************************/
1156/* Sequential write functions                                         */
1157/**********************************************************************/
1158
1159int fdt_create(void *buf, int bufsize);
1160int fdt_resize(void *fdt, void *buf, int bufsize);
1161int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size);
1162int fdt_finish_reservemap(void *fdt);
1163int fdt_begin_node(void *fdt, const char *name);
1164int fdt_property(void *fdt, const char *name, const void *val, int len);
1165static inline int fdt_property_u32(void *fdt, const char *name, uint32_t val)
1166{
1167        fdt32_t tmp = cpu_to_fdt32(val);
1168        return fdt_property(fdt, name, &tmp, sizeof(tmp));
1169}
1170static inline int fdt_property_u64(void *fdt, const char *name, uint64_t val)
1171{
1172        fdt64_t tmp = cpu_to_fdt64(val);
1173        return fdt_property(fdt, name, &tmp, sizeof(tmp));
1174}
1175static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val)
1176{
1177        return fdt_property_u32(fdt, name, val);
1178}
1179#define fdt_property_string(fdt, name, str) \
1180        fdt_property(fdt, name, str, strlen(str)+1)
1181int fdt_end_node(void *fdt);
1182int fdt_finish(void *fdt);
1183
1184/**********************************************************************/
1185/* Read-write functions                                               */
1186/**********************************************************************/
1187
1188int fdt_create_empty_tree(void *buf, int bufsize);
1189int fdt_open_into(const void *fdt, void *buf, int bufsize);
1190int fdt_pack(void *fdt);
1191
1192/**
1193 * fdt_add_mem_rsv - add one memory reserve map entry
1194 * @fdt: pointer to the device tree blob
1195 * @address, @size: 64-bit values (native endian)
1196 *
1197 * Adds a reserve map entry to the given blob reserving a region at
1198 * address address of length size.
1199 *
1200 * This function will insert data into the reserve map and will
1201 * therefore change the indexes of some entries in the table.
1202 *
1203 * returns:
1204 *      0, on success
1205 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1206 *              contain the new reservation entry
1207 *      -FDT_ERR_BADMAGIC,
1208 *      -FDT_ERR_BADVERSION,
1209 *      -FDT_ERR_BADSTATE,
1210 *      -FDT_ERR_BADSTRUCTURE,
1211 *      -FDT_ERR_BADLAYOUT,
1212 *      -FDT_ERR_TRUNCATED, standard meanings
1213 */
1214int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size);
1215
1216/**
1217 * fdt_del_mem_rsv - remove a memory reserve map entry
1218 * @fdt: pointer to the device tree blob
1219 * @n: entry to remove
1220 *
1221 * fdt_del_mem_rsv() removes the n-th memory reserve map entry from
1222 * the blob.
1223 *
1224 * This function will delete data from the reservation table and will
1225 * therefore change the indexes of some entries in the table.
1226 *
1227 * returns:
1228 *      0, on success
1229 *      -FDT_ERR_NOTFOUND, there is no entry of the given index (i.e. there
1230 *              are less than n+1 reserve map entries)
1231 *      -FDT_ERR_BADMAGIC,
1232 *      -FDT_ERR_BADVERSION,
1233 *      -FDT_ERR_BADSTATE,
1234 *      -FDT_ERR_BADSTRUCTURE,
1235 *      -FDT_ERR_BADLAYOUT,
1236 *      -FDT_ERR_TRUNCATED, standard meanings
1237 */
1238int fdt_del_mem_rsv(void *fdt, int n);
1239
1240/**
1241 * fdt_set_name - change the name of a given node
1242 * @fdt: pointer to the device tree blob
1243 * @nodeoffset: structure block offset of a node
1244 * @name: name to give the node
1245 *
1246 * fdt_set_name() replaces the name (including unit address, if any)
1247 * of the given node with the given string.  NOTE: this function can't
1248 * efficiently check if the new name is unique amongst the given
1249 * node's siblings; results are undefined if this function is invoked
1250 * with a name equal to one of the given node's siblings.
1251 *
1252 * This function may insert or delete data from the blob, and will
1253 * therefore change the offsets of some existing nodes.
1254 *
1255 * returns:
1256 *      0, on success
1257 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob
1258 *              to contain the new name
1259 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1260 *      -FDT_ERR_BADMAGIC,
1261 *      -FDT_ERR_BADVERSION,
1262 *      -FDT_ERR_BADSTATE, standard meanings
1263 */
1264int fdt_set_name(void *fdt, int nodeoffset, const char *name);
1265
1266/**
1267 * fdt_setprop - create or change a property
1268 * @fdt: pointer to the device tree blob
1269 * @nodeoffset: offset of the node whose property to change
1270 * @name: name of the property to change
1271 * @val: pointer to data to set the property value to
1272 * @len: length of the property value
1273 *
1274 * fdt_setprop() sets the value of the named property in the given
1275 * node to the given value and length, creating the property if it
1276 * does not already exist.
1277 *
1278 * This function may insert or delete data from the blob, and will
1279 * therefore change the offsets of some existing nodes.
1280 *
1281 * returns:
1282 *      0, on success
1283 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1284 *              contain the new property value
1285 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1286 *      -FDT_ERR_BADLAYOUT,
1287 *      -FDT_ERR_BADMAGIC,
1288 *      -FDT_ERR_BADVERSION,
1289 *      -FDT_ERR_BADSTATE,
1290 *      -FDT_ERR_BADSTRUCTURE,
1291 *      -FDT_ERR_BADLAYOUT,
1292 *      -FDT_ERR_TRUNCATED, standard meanings
1293 */
1294int fdt_setprop(void *fdt, int nodeoffset, const char *name,
1295                const void *val, int len);
1296
1297/**
1298 * fdt_setprop_u32 - set a property to a 32-bit integer
1299 * @fdt: pointer to the device tree blob
1300 * @nodeoffset: offset of the node whose property to change
1301 * @name: name of the property to change
1302 * @val: 32-bit integer value for the property (native endian)
1303 *
1304 * fdt_setprop_u32() sets the value of the named property in the given
1305 * node to the given 32-bit integer value (converting to big-endian if
1306 * necessary), or creates a new property with that value if it does
1307 * not already exist.
1308 *
1309 * This function may insert or delete data from the blob, and will
1310 * therefore change the offsets of some existing nodes.
1311 *
1312 * returns:
1313 *      0, on success
1314 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1315 *              contain the new property value
1316 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1317 *      -FDT_ERR_BADLAYOUT,
1318 *      -FDT_ERR_BADMAGIC,
1319 *      -FDT_ERR_BADVERSION,
1320 *      -FDT_ERR_BADSTATE,
1321 *      -FDT_ERR_BADSTRUCTURE,
1322 *      -FDT_ERR_BADLAYOUT,
1323 *      -FDT_ERR_TRUNCATED, standard meanings
1324 */
1325static inline int fdt_setprop_u32(void *fdt, int nodeoffset, const char *name,
1326                                  uint32_t val)
1327{
1328        fdt32_t tmp = cpu_to_fdt32(val);
1329        return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1330}
1331
1332/**
1333 * fdt_setprop_u64 - set a property to a 64-bit integer
1334 * @fdt: pointer to the device tree blob
1335 * @nodeoffset: offset of the node whose property to change
1336 * @name: name of the property to change
1337 * @val: 64-bit integer value for the property (native endian)
1338 *
1339 * fdt_setprop_u64() sets the value of the named property in the given
1340 * node to the given 64-bit integer value (converting to big-endian if
1341 * necessary), or creates a new property with that value if it does
1342 * not already exist.
1343 *
1344 * This function may insert or delete data from the blob, and will
1345 * therefore change the offsets of some existing nodes.
1346 *
1347 * returns:
1348 *      0, on success
1349 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1350 *              contain the new property value
1351 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1352 *      -FDT_ERR_BADLAYOUT,
1353 *      -FDT_ERR_BADMAGIC,
1354 *      -FDT_ERR_BADVERSION,
1355 *      -FDT_ERR_BADSTATE,
1356 *      -FDT_ERR_BADSTRUCTURE,
1357 *      -FDT_ERR_BADLAYOUT,
1358 *      -FDT_ERR_TRUNCATED, standard meanings
1359 */
1360static inline int fdt_setprop_u64(void *fdt, int nodeoffset, const char *name,
1361                                  uint64_t val)
1362{
1363        fdt64_t tmp = cpu_to_fdt64(val);
1364        return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1365}
1366
1367/**
1368 * fdt_setprop_cell - set a property to a single cell value
1369 *
1370 * This is an alternative name for fdt_setprop_u32()
1371 */
1372static inline int fdt_setprop_cell(void *fdt, int nodeoffset, const char *name,
1373                                   uint32_t val)
1374{
1375        return fdt_setprop_u32(fdt, nodeoffset, name, val);
1376}
1377
1378/**
1379 * fdt_setprop_string - set a property to a string value
1380 * @fdt: pointer to the device tree blob
1381 * @nodeoffset: offset of the node whose property to change
1382 * @name: name of the property to change
1383 * @str: string value for the property
1384 *
1385 * fdt_setprop_string() sets the value of the named property in the
1386 * given node to the given string value (using the length of the
1387 * string to determine the new length of the property), or creates a
1388 * new property with that value if it does not already exist.
1389 *
1390 * This function may insert or delete data from the blob, and will
1391 * therefore change the offsets of some existing nodes.
1392 *
1393 * returns:
1394 *      0, on success
1395 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1396 *              contain the new property value
1397 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1398 *      -FDT_ERR_BADLAYOUT,
1399 *      -FDT_ERR_BADMAGIC,
1400 *      -FDT_ERR_BADVERSION,
1401 *      -FDT_ERR_BADSTATE,
1402 *      -FDT_ERR_BADSTRUCTURE,
1403 *      -FDT_ERR_BADLAYOUT,
1404 *      -FDT_ERR_TRUNCATED, standard meanings
1405 */
1406#define fdt_setprop_string(fdt, nodeoffset, name, str) \
1407        fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1408
1409/**
1410 * fdt_appendprop - append to or create a property
1411 * @fdt: pointer to the device tree blob
1412 * @nodeoffset: offset of the node whose property to change
1413 * @name: name of the property to append to
1414 * @val: pointer to data to append to the property value
1415 * @len: length of the data to append to the property value
1416 *
1417 * fdt_appendprop() appends the value to the named property in the
1418 * given node, creating the property if it does not already exist.
1419 *
1420 * This function may insert data into the blob, and will therefore
1421 * change the offsets of some existing nodes.
1422 *
1423 * returns:
1424 *      0, on success
1425 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1426 *              contain the new property value
1427 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1428 *      -FDT_ERR_BADLAYOUT,
1429 *      -FDT_ERR_BADMAGIC,
1430 *      -FDT_ERR_BADVERSION,
1431 *      -FDT_ERR_BADSTATE,
1432 *      -FDT_ERR_BADSTRUCTURE,
1433 *      -FDT_ERR_BADLAYOUT,
1434 *      -FDT_ERR_TRUNCATED, standard meanings
1435 */
1436int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
1437                   const void *val, int len);
1438
1439/**
1440 * fdt_appendprop_u32 - append a 32-bit integer value to a property
1441 * @fdt: pointer to the device tree blob
1442 * @nodeoffset: offset of the node whose property to change
1443 * @name: name of the property to change
1444 * @val: 32-bit integer value to append to the property (native endian)
1445 *
1446 * fdt_appendprop_u32() appends the given 32-bit integer value
1447 * (converting to big-endian if necessary) to the value of the named
1448 * property in the given node, or creates a new property with that
1449 * value if it does not already exist.
1450 *
1451 * This function may insert data into the blob, and will therefore
1452 * change the offsets of some existing nodes.
1453 *
1454 * returns:
1455 *      0, on success
1456 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1457 *              contain the new property value
1458 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1459 *      -FDT_ERR_BADLAYOUT,
1460 *      -FDT_ERR_BADMAGIC,
1461 *      -FDT_ERR_BADVERSION,
1462 *      -FDT_ERR_BADSTATE,
1463 *      -FDT_ERR_BADSTRUCTURE,
1464 *      -FDT_ERR_BADLAYOUT,
1465 *      -FDT_ERR_TRUNCATED, standard meanings
1466 */
1467static inline int fdt_appendprop_u32(void *fdt, int nodeoffset,
1468                                     const char *name, uint32_t val)
1469{
1470        fdt32_t tmp = cpu_to_fdt32(val);
1471        return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1472}
1473
1474/**
1475 * fdt_appendprop_u64 - append a 64-bit integer value to a property
1476 * @fdt: pointer to the device tree blob
1477 * @nodeoffset: offset of the node whose property to change
1478 * @name: name of the property to change
1479 * @val: 64-bit integer value to append to the property (native endian)
1480 *
1481 * fdt_appendprop_u64() appends the given 64-bit integer value
1482 * (converting to big-endian if necessary) to the value of the named
1483 * property in the given node, or creates a new property with that
1484 * value if it does not already exist.
1485 *
1486 * This function may insert data into the blob, and will therefore
1487 * change the offsets of some existing nodes.
1488 *
1489 * returns:
1490 *      0, on success
1491 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1492 *              contain the new property value
1493 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1494 *      -FDT_ERR_BADLAYOUT,
1495 *      -FDT_ERR_BADMAGIC,
1496 *      -FDT_ERR_BADVERSION,
1497 *      -FDT_ERR_BADSTATE,
1498 *      -FDT_ERR_BADSTRUCTURE,
1499 *      -FDT_ERR_BADLAYOUT,
1500 *      -FDT_ERR_TRUNCATED, standard meanings
1501 */
1502static inline int fdt_appendprop_u64(void *fdt, int nodeoffset,
1503                                     const char *name, uint64_t val)
1504{
1505        fdt64_t tmp = cpu_to_fdt64(val);
1506        return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1507}
1508
1509/**
1510 * fdt_appendprop_cell - append a single cell value to a property
1511 *
1512 * This is an alternative name for fdt_appendprop_u32()
1513 */
1514static inline int fdt_appendprop_cell(void *fdt, int nodeoffset,
1515                                      const char *name, uint32_t val)
1516{
1517        return fdt_appendprop_u32(fdt, nodeoffset, name, val);
1518}
1519
1520/**
1521 * fdt_appendprop_string - append a string to a property
1522 * @fdt: pointer to the device tree blob
1523 * @nodeoffset: offset of the node whose property to change
1524 * @name: name of the property to change
1525 * @str: string value to append to the property
1526 *
1527 * fdt_appendprop_string() appends the given string to the value of
1528 * the named property in the given node, or creates a new property
1529 * with that value if it does not already exist.
1530 *
1531 * This function may insert data into the blob, and will therefore
1532 * change the offsets of some existing nodes.
1533 *
1534 * returns:
1535 *      0, on success
1536 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1537 *              contain the new property value
1538 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1539 *      -FDT_ERR_BADLAYOUT,
1540 *      -FDT_ERR_BADMAGIC,
1541 *      -FDT_ERR_BADVERSION,
1542 *      -FDT_ERR_BADSTATE,
1543 *      -FDT_ERR_BADSTRUCTURE,
1544 *      -FDT_ERR_BADLAYOUT,
1545 *      -FDT_ERR_TRUNCATED, standard meanings
1546 */
1547#define fdt_appendprop_string(fdt, nodeoffset, name, str) \
1548        fdt_appendprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1549
1550/**
1551 * fdt_delprop - delete a property
1552 * @fdt: pointer to the device tree blob
1553 * @nodeoffset: offset of the node whose property to nop
1554 * @name: name of the property to nop
1555 *
1556 * fdt_del_property() will delete the given property.
1557 *
1558 * This function will delete data from the blob, and will therefore
1559 * change the offsets of some existing nodes.
1560 *
1561 * returns:
1562 *      0, on success
1563 *      -FDT_ERR_NOTFOUND, node does not have the named property
1564 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1565 *      -FDT_ERR_BADLAYOUT,
1566 *      -FDT_ERR_BADMAGIC,
1567 *      -FDT_ERR_BADVERSION,
1568 *      -FDT_ERR_BADSTATE,
1569 *      -FDT_ERR_BADSTRUCTURE,
1570 *      -FDT_ERR_TRUNCATED, standard meanings
1571 */
1572int fdt_delprop(void *fdt, int nodeoffset, const char *name);
1573
1574/**
1575 * fdt_add_subnode_namelen - creates a new node based on substring
1576 * @fdt: pointer to the device tree blob
1577 * @parentoffset: structure block offset of a node
1578 * @name: name of the subnode to locate
1579 * @namelen: number of characters of name to consider
1580 *
1581 * Identical to fdt_add_subnode(), but use only the first namelen
1582 * characters of name as the name of the new node.  This is useful for
1583 * creating subnodes based on a portion of a larger string, such as a
1584 * full path.
1585 */
1586int fdt_add_subnode_namelen(void *fdt, int parentoffset,
1587                            const char *name, int namelen);
1588
1589/**
1590 * fdt_add_subnode - creates a new node
1591 * @fdt: pointer to the device tree blob
1592 * @parentoffset: structure block offset of a node
1593 * @name: name of the subnode to locate
1594 *
1595 * fdt_add_subnode() creates a new node as a subnode of the node at
1596 * structure block offset parentoffset, with the given name (which
1597 * should include the unit address, if any).
1598 *
1599 * This function will insert data into the blob, and will therefore
1600 * change the offsets of some existing nodes.
1601
1602 * returns:
1603 *      structure block offset of the created nodeequested subnode (>=0), on success
1604 *      -FDT_ERR_NOTFOUND, if the requested subnode does not exist
1605 *      -FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag
1606 *      -FDT_ERR_EXISTS, if the node at parentoffset already has a subnode of
1607 *              the given name
1608 *      -FDT_ERR_NOSPACE, if there is insufficient free space in the
1609 *              blob to contain the new node
1610 *      -FDT_ERR_NOSPACE
1611 *      -FDT_ERR_BADLAYOUT
1612 *      -FDT_ERR_BADMAGIC,
1613 *      -FDT_ERR_BADVERSION,
1614 *      -FDT_ERR_BADSTATE,
1615 *      -FDT_ERR_BADSTRUCTURE,
1616 *      -FDT_ERR_TRUNCATED, standard meanings.
1617 */
1618int fdt_add_subnode(void *fdt, int parentoffset, const char *name);
1619
1620/**
1621 * fdt_del_node - delete a node (subtree)
1622 * @fdt: pointer to the device tree blob
1623 * @nodeoffset: offset of the node to nop
1624 *
1625 * fdt_del_node() will remove the given node, including all its
1626 * subnodes if any, from the blob.
1627 *
1628 * This function will delete data from the blob, and will therefore
1629 * change the offsets of some existing nodes.
1630 *
1631 * returns:
1632 *      0, on success
1633 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1634 *      -FDT_ERR_BADLAYOUT,
1635 *      -FDT_ERR_BADMAGIC,
1636 *      -FDT_ERR_BADVERSION,
1637 *      -FDT_ERR_BADSTATE,
1638 *      -FDT_ERR_BADSTRUCTURE,
1639 *      -FDT_ERR_TRUNCATED, standard meanings
1640 */
1641int fdt_del_node(void *fdt, int nodeoffset);
1642
1643/**********************************************************************/
1644/* Debugging / informational functions                                */
1645/**********************************************************************/
1646
1647const char *fdt_strerror(int errval);
1648
1649struct fdt_region {
1650        int offset;
1651        int size;
1652};
1653
1654/**
1655 * fdt_find_regions() - find regions in device tree
1656 *
1657 * Given a list of nodes to include and properties to exclude, find
1658 * the regions of the device tree which describe those included parts.
1659 *
1660 * The intent is to get a list of regions which will be invariant provided
1661 * those parts are invariant. For example, if you request a list of regions
1662 * for all nodes but exclude the property "data", then you will get the
1663 * same region contents regardless of any change to "data" properties.
1664 *
1665 * This function can be used to produce a byte-stream to send to a hashing
1666 * function to verify that critical parts of the FDT have not changed.
1667 *
1668 * Nodes which are given in 'inc' are included in the region list, as
1669 * are the names of the immediate subnodes nodes (but not the properties
1670 * or subnodes of those subnodes).
1671 *
1672 * For eaxample "/" means to include the root node, all root properties
1673 * and the FDT_BEGIN_NODE and FDT_END_NODE of all subnodes of /. The latter
1674 * ensures that we capture the names of the subnodes. In a hashing situation
1675 * it prevents the root node from changing at all Any change to non-excluded
1676 * properties, names of subnodes or number of subnodes would be detected.
1677 *
1678 * When used with FITs this provides the ability to hash and sign parts of
1679 * the FIT based on different configurations in the FIT. Then it is
1680 * impossible to change anything about that configuration (include images
1681 * attached to the configuration), but it may be possible to add new
1682 * configurations, new images or new signatures within the existing
1683 * framework.
1684 *
1685 * Adding new properties to a device tree may result in the string table
1686 * being extended (if the new property names are different from those
1687 * already added). This function can optionally include a region for
1688 * the string table so that this can be part of the hash too.
1689 *
1690 * The device tree header is not included in the list.
1691 *
1692 * @fdt:        Device tree to check
1693 * @inc:        List of node paths to included
1694 * @inc_count:  Number of node paths in list
1695 * @exc_prop:   List of properties names to exclude
1696 * @exc_prop_count:     Number of properties in exclude list
1697 * @region:     Returns list of regions
1698 * @max_region: Maximum length of region list
1699 * @path:       Pointer to a temporary string for the function to use for
1700 *              building path names
1701 * @path_len:   Length of path, must be large enough to hold the longest
1702 *              path in the tree
1703 * @add_string_tab:     1 to add a region for the string table
1704 * @return number of regions in list. If this is >max_regions then the
1705 * region array was exhausted. You should increase max_regions and try
1706 * the call again.
1707 */
1708int fdt_find_regions(const void *fdt, char * const inc[], int inc_count,
1709                     char * const exc_prop[], int exc_prop_count,
1710                     struct fdt_region region[], int max_regions,
1711                     char *path, int path_len, int add_string_tab);
1712
1713#endif /* _LIBFDT_H */
1714