linux/scripts/dtc/libfdt/libfdt.h
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   1/* SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) */
   2#ifndef LIBFDT_H
   3#define LIBFDT_H
   4/*
   5 * libfdt - Flat Device Tree manipulation
   6 * Copyright (C) 2006 David Gibson, IBM Corporation.
   7 */
   8
   9#include "libfdt_env.h"
  10#include "fdt.h"
  11
  12#ifdef __cplusplus
  13extern "C" {
  14#endif
  15
  16#define FDT_FIRST_SUPPORTED_VERSION     0x02
  17#define FDT_LAST_COMPATIBLE_VERSION 0x10
  18#define FDT_LAST_SUPPORTED_VERSION      0x11
  19
  20/* Error codes: informative error codes */
  21#define FDT_ERR_NOTFOUND        1
  22        /* FDT_ERR_NOTFOUND: The requested node or property does not exist */
  23#define FDT_ERR_EXISTS          2
  24        /* FDT_ERR_EXISTS: Attempted to create a node or property which
  25         * already exists */
  26#define FDT_ERR_NOSPACE         3
  27        /* FDT_ERR_NOSPACE: Operation needed to expand the device
  28         * tree, but its buffer did not have sufficient space to
  29         * contain the expanded tree. Use fdt_open_into() to move the
  30         * device tree to a buffer with more space. */
  31
  32/* Error codes: codes for bad parameters */
  33#define FDT_ERR_BADOFFSET       4
  34        /* FDT_ERR_BADOFFSET: Function was passed a structure block
  35         * offset which is out-of-bounds, or which points to an
  36         * unsuitable part of the structure for the operation. */
  37#define FDT_ERR_BADPATH         5
  38        /* FDT_ERR_BADPATH: Function was passed a badly formatted path
  39         * (e.g. missing a leading / for a function which requires an
  40         * absolute path) */
  41#define FDT_ERR_BADPHANDLE      6
  42        /* FDT_ERR_BADPHANDLE: Function was passed an invalid phandle.
  43         * This can be caused either by an invalid phandle property
  44         * length, or the phandle value was either 0 or -1, which are
  45         * not permitted. */
  46#define FDT_ERR_BADSTATE        7
  47        /* FDT_ERR_BADSTATE: Function was passed an incomplete device
  48         * tree created by the sequential-write functions, which is
  49         * not sufficiently complete for the requested operation. */
  50
  51/* Error codes: codes for bad device tree blobs */
  52#define FDT_ERR_TRUNCATED       8
  53        /* FDT_ERR_TRUNCATED: FDT or a sub-block is improperly
  54         * terminated (overflows, goes outside allowed bounds, or
  55         * isn't properly terminated).  */
  56#define FDT_ERR_BADMAGIC        9
  57        /* FDT_ERR_BADMAGIC: Given "device tree" appears not to be a
  58         * device tree at all - it is missing the flattened device
  59         * tree magic number. */
  60#define FDT_ERR_BADVERSION      10
  61        /* FDT_ERR_BADVERSION: Given device tree has a version which
  62         * can't be handled by the requested operation.  For
  63         * read-write functions, this may mean that fdt_open_into() is
  64         * required to convert the tree to the expected version. */
  65#define FDT_ERR_BADSTRUCTURE    11
  66        /* FDT_ERR_BADSTRUCTURE: Given device tree has a corrupt
  67         * structure block or other serious error (e.g. misnested
  68         * nodes, or subnodes preceding properties). */
  69#define FDT_ERR_BADLAYOUT       12
  70        /* FDT_ERR_BADLAYOUT: For read-write functions, the given
  71         * device tree has it's sub-blocks in an order that the
  72         * function can't handle (memory reserve map, then structure,
  73         * then strings).  Use fdt_open_into() to reorganize the tree
  74         * into a form suitable for the read-write operations. */
  75
  76/* "Can't happen" error indicating a bug in libfdt */
  77#define FDT_ERR_INTERNAL        13
  78        /* FDT_ERR_INTERNAL: libfdt has failed an internal assertion.
  79         * Should never be returned, if it is, it indicates a bug in
  80         * libfdt itself. */
  81
  82/* Errors in device tree content */
  83#define FDT_ERR_BADNCELLS       14
  84        /* FDT_ERR_BADNCELLS: Device tree has a #address-cells, #size-cells
  85         * or similar property with a bad format or value */
  86
  87#define FDT_ERR_BADVALUE        15
  88        /* FDT_ERR_BADVALUE: Device tree has a property with an unexpected
  89         * value. For example: a property expected to contain a string list
  90         * is not NUL-terminated within the length of its value. */
  91
  92#define FDT_ERR_BADOVERLAY      16
  93        /* FDT_ERR_BADOVERLAY: The device tree overlay, while
  94         * correctly structured, cannot be applied due to some
  95         * unexpected or missing value, property or node. */
  96
  97#define FDT_ERR_NOPHANDLES      17
  98        /* FDT_ERR_NOPHANDLES: The device tree doesn't have any
  99         * phandle available anymore without causing an overflow */
 100
 101#define FDT_ERR_BADFLAGS        18
 102        /* FDT_ERR_BADFLAGS: The function was passed a flags field that
 103         * contains invalid flags or an invalid combination of flags. */
 104
 105#define FDT_ERR_ALIGNMENT       19
 106        /* FDT_ERR_ALIGNMENT: The device tree base address is not 8-byte
 107         * aligned. */
 108
 109#define FDT_ERR_MAX             19
 110
 111/* constants */
 112#define FDT_MAX_PHANDLE 0xfffffffe
 113        /* Valid values for phandles range from 1 to 2^32-2. */
 114
 115/**********************************************************************/
 116/* Low-level functions (you probably don't need these)                */
 117/**********************************************************************/
 118
 119#ifndef SWIG /* This function is not useful in Python */
 120const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int checklen);
 121#endif
 122static inline void *fdt_offset_ptr_w(void *fdt, int offset, int checklen)
 123{
 124        return (void *)(uintptr_t)fdt_offset_ptr(fdt, offset, checklen);
 125}
 126
 127uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset);
 128
 129/*
 130 * External helpers to access words from a device tree blob. They're built
 131 * to work even with unaligned pointers on platforms (such as ARMv5) that don't
 132 * like unaligned loads and stores.
 133 */
 134static inline uint16_t fdt16_ld(const fdt16_t *p)
 135{
 136        const uint8_t *bp = (const uint8_t *)p;
 137
 138        return ((uint16_t)bp[0] << 8) | bp[1];
 139}
 140
 141static inline uint32_t fdt32_ld(const fdt32_t *p)
 142{
 143        const uint8_t *bp = (const uint8_t *)p;
 144
 145        return ((uint32_t)bp[0] << 24)
 146                | ((uint32_t)bp[1] << 16)
 147                | ((uint32_t)bp[2] << 8)
 148                | bp[3];
 149}
 150
 151static inline void fdt32_st(void *property, uint32_t value)
 152{
 153        uint8_t *bp = (uint8_t *)property;
 154
 155        bp[0] = value >> 24;
 156        bp[1] = (value >> 16) & 0xff;
 157        bp[2] = (value >> 8) & 0xff;
 158        bp[3] = value & 0xff;
 159}
 160
 161static inline uint64_t fdt64_ld(const fdt64_t *p)
 162{
 163        const uint8_t *bp = (const uint8_t *)p;
 164
 165        return ((uint64_t)bp[0] << 56)
 166                | ((uint64_t)bp[1] << 48)
 167                | ((uint64_t)bp[2] << 40)
 168                | ((uint64_t)bp[3] << 32)
 169                | ((uint64_t)bp[4] << 24)
 170                | ((uint64_t)bp[5] << 16)
 171                | ((uint64_t)bp[6] << 8)
 172                | bp[7];
 173}
 174
 175static inline void fdt64_st(void *property, uint64_t value)
 176{
 177        uint8_t *bp = (uint8_t *)property;
 178
 179        bp[0] = value >> 56;
 180        bp[1] = (value >> 48) & 0xff;
 181        bp[2] = (value >> 40) & 0xff;
 182        bp[3] = (value >> 32) & 0xff;
 183        bp[4] = (value >> 24) & 0xff;
 184        bp[5] = (value >> 16) & 0xff;
 185        bp[6] = (value >> 8) & 0xff;
 186        bp[7] = value & 0xff;
 187}
 188
 189/**********************************************************************/
 190/* Traversal functions                                                */
 191/**********************************************************************/
 192
 193int fdt_next_node(const void *fdt, int offset, int *depth);
 194
 195/**
 196 * fdt_first_subnode() - get offset of first direct subnode
 197 * @fdt:        FDT blob
 198 * @offset:     Offset of node to check
 199 *
 200 * Return: offset of first subnode, or -FDT_ERR_NOTFOUND if there is none
 201 */
 202int fdt_first_subnode(const void *fdt, int offset);
 203
 204/**
 205 * fdt_next_subnode() - get offset of next direct subnode
 206 * @fdt:        FDT blob
 207 * @offset:     Offset of previous subnode
 208 *
 209 * After first calling fdt_first_subnode(), call this function repeatedly to
 210 * get direct subnodes of a parent node.
 211 *
 212 * Return: offset of next subnode, or -FDT_ERR_NOTFOUND if there are no more
 213 *         subnodes
 214 */
 215int fdt_next_subnode(const void *fdt, int offset);
 216
 217/**
 218 * fdt_for_each_subnode - iterate over all subnodes of a parent
 219 *
 220 * @node:       child node (int, lvalue)
 221 * @fdt:        FDT blob (const void *)
 222 * @parent:     parent node (int)
 223 *
 224 * This is actually a wrapper around a for loop and would be used like so:
 225 *
 226 *      fdt_for_each_subnode(node, fdt, parent) {
 227 *              Use node
 228 *              ...
 229 *      }
 230 *
 231 *      if ((node < 0) && (node != -FDT_ERR_NOTFOUND)) {
 232 *              Error handling
 233 *      }
 234 *
 235 * Note that this is implemented as a macro and @node is used as
 236 * iterator in the loop. The parent variable be constant or even a
 237 * literal.
 238 */
 239#define fdt_for_each_subnode(node, fdt, parent)         \
 240        for (node = fdt_first_subnode(fdt, parent);     \
 241             node >= 0;                                 \
 242             node = fdt_next_subnode(fdt, node))
 243
 244/**********************************************************************/
 245/* General functions                                                  */
 246/**********************************************************************/
 247#define fdt_get_header(fdt, field) \
 248        (fdt32_ld(&((const struct fdt_header *)(fdt))->field))
 249#define fdt_magic(fdt)                  (fdt_get_header(fdt, magic))
 250#define fdt_totalsize(fdt)              (fdt_get_header(fdt, totalsize))
 251#define fdt_off_dt_struct(fdt)          (fdt_get_header(fdt, off_dt_struct))
 252#define fdt_off_dt_strings(fdt)         (fdt_get_header(fdt, off_dt_strings))
 253#define fdt_off_mem_rsvmap(fdt)         (fdt_get_header(fdt, off_mem_rsvmap))
 254#define fdt_version(fdt)                (fdt_get_header(fdt, version))
 255#define fdt_last_comp_version(fdt)      (fdt_get_header(fdt, last_comp_version))
 256#define fdt_boot_cpuid_phys(fdt)        (fdt_get_header(fdt, boot_cpuid_phys))
 257#define fdt_size_dt_strings(fdt)        (fdt_get_header(fdt, size_dt_strings))
 258#define fdt_size_dt_struct(fdt)         (fdt_get_header(fdt, size_dt_struct))
 259
 260#define fdt_set_hdr_(name) \
 261        static inline void fdt_set_##name(void *fdt, uint32_t val) \
 262        { \
 263                struct fdt_header *fdth = (struct fdt_header *)fdt; \
 264                fdth->name = cpu_to_fdt32(val); \
 265        }
 266fdt_set_hdr_(magic);
 267fdt_set_hdr_(totalsize);
 268fdt_set_hdr_(off_dt_struct);
 269fdt_set_hdr_(off_dt_strings);
 270fdt_set_hdr_(off_mem_rsvmap);
 271fdt_set_hdr_(version);
 272fdt_set_hdr_(last_comp_version);
 273fdt_set_hdr_(boot_cpuid_phys);
 274fdt_set_hdr_(size_dt_strings);
 275fdt_set_hdr_(size_dt_struct);
 276#undef fdt_set_hdr_
 277
 278/**
 279 * fdt_header_size - return the size of the tree's header
 280 * @fdt: pointer to a flattened device tree
 281 *
 282 * Return: size of DTB header in bytes
 283 */
 284size_t fdt_header_size(const void *fdt);
 285
 286/**
 287 * fdt_header_size_ - internal function to get header size from a version number
 288 * @version: devicetree version number
 289 *
 290 * Return: size of DTB header in bytes
 291 */
 292size_t fdt_header_size_(uint32_t version);
 293
 294/**
 295 * fdt_check_header - sanity check a device tree header
 296 * @fdt: pointer to data which might be a flattened device tree
 297 *
 298 * fdt_check_header() checks that the given buffer contains what
 299 * appears to be a flattened device tree, and that the header contains
 300 * valid information (to the extent that can be determined from the
 301 * header alone).
 302 *
 303 * returns:
 304 *     0, if the buffer appears to contain a valid device tree
 305 *     -FDT_ERR_BADMAGIC,
 306 *     -FDT_ERR_BADVERSION,
 307 *     -FDT_ERR_BADSTATE,
 308 *     -FDT_ERR_TRUNCATED, standard meanings, as above
 309 */
 310int fdt_check_header(const void *fdt);
 311
 312/**
 313 * fdt_move - move a device tree around in memory
 314 * @fdt: pointer to the device tree to move
 315 * @buf: pointer to memory where the device is to be moved
 316 * @bufsize: size of the memory space at buf
 317 *
 318 * fdt_move() relocates, if possible, the device tree blob located at
 319 * fdt to the buffer at buf of size bufsize.  The buffer may overlap
 320 * with the existing device tree blob at fdt.  Therefore,
 321 *     fdt_move(fdt, fdt, fdt_totalsize(fdt))
 322 * should always succeed.
 323 *
 324 * returns:
 325 *     0, on success
 326 *     -FDT_ERR_NOSPACE, bufsize is insufficient to contain the device tree
 327 *     -FDT_ERR_BADMAGIC,
 328 *     -FDT_ERR_BADVERSION,
 329 *     -FDT_ERR_BADSTATE, standard meanings
 330 */
 331int fdt_move(const void *fdt, void *buf, int bufsize);
 332
 333/**********************************************************************/
 334/* Read-only functions                                                */
 335/**********************************************************************/
 336
 337int fdt_check_full(const void *fdt, size_t bufsize);
 338
 339/**
 340 * fdt_get_string - retrieve a string from the strings block of a device tree
 341 * @fdt: pointer to the device tree blob
 342 * @stroffset: offset of the string within the strings block (native endian)
 343 * @lenp: optional pointer to return the string's length
 344 *
 345 * fdt_get_string() retrieves a pointer to a single string from the
 346 * strings block of the device tree blob at fdt, and optionally also
 347 * returns the string's length in *lenp.
 348 *
 349 * returns:
 350 *     a pointer to the string, on success
 351 *     NULL, if stroffset is out of bounds, or doesn't point to a valid string
 352 */
 353const char *fdt_get_string(const void *fdt, int stroffset, int *lenp);
 354
 355/**
 356 * fdt_string - retrieve a string from the strings block of a device tree
 357 * @fdt: pointer to the device tree blob
 358 * @stroffset: offset of the string within the strings block (native endian)
 359 *
 360 * fdt_string() retrieves a pointer to a single string from the
 361 * strings block of the device tree blob at fdt.
 362 *
 363 * returns:
 364 *     a pointer to the string, on success
 365 *     NULL, if stroffset is out of bounds, or doesn't point to a valid string
 366 */
 367const char *fdt_string(const void *fdt, int stroffset);
 368
 369/**
 370 * fdt_find_max_phandle - find and return the highest phandle in a tree
 371 * @fdt: pointer to the device tree blob
 372 * @phandle: return location for the highest phandle value found in the tree
 373 *
 374 * fdt_find_max_phandle() finds the highest phandle value in the given device
 375 * tree. The value returned in @phandle is only valid if the function returns
 376 * success.
 377 *
 378 * returns:
 379 *     0 on success or a negative error code on failure
 380 */
 381int fdt_find_max_phandle(const void *fdt, uint32_t *phandle);
 382
 383/**
 384 * fdt_get_max_phandle - retrieves the highest phandle in a tree
 385 * @fdt: pointer to the device tree blob
 386 *
 387 * fdt_get_max_phandle retrieves the highest phandle in the given
 388 * device tree. This will ignore badly formatted phandles, or phandles
 389 * with a value of 0 or -1.
 390 *
 391 * This function is deprecated in favour of fdt_find_max_phandle().
 392 *
 393 * returns:
 394 *      the highest phandle on success
 395 *      0, if no phandle was found in the device tree
 396 *      -1, if an error occurred
 397 */
 398static inline uint32_t fdt_get_max_phandle(const void *fdt)
 399{
 400        uint32_t phandle;
 401        int err;
 402
 403        err = fdt_find_max_phandle(fdt, &phandle);
 404        if (err < 0)
 405                return (uint32_t)-1;
 406
 407        return phandle;
 408}
 409
 410/**
 411 * fdt_generate_phandle - return a new, unused phandle for a device tree blob
 412 * @fdt: pointer to the device tree blob
 413 * @phandle: return location for the new phandle
 414 *
 415 * Walks the device tree blob and looks for the highest phandle value. On
 416 * success, the new, unused phandle value (one higher than the previously
 417 * highest phandle value in the device tree blob) will be returned in the
 418 * @phandle parameter.
 419 *
 420 * Return: 0 on success or a negative error-code on failure
 421 */
 422int fdt_generate_phandle(const void *fdt, uint32_t *phandle);
 423
 424/**
 425 * fdt_num_mem_rsv - retrieve the number of memory reserve map entries
 426 * @fdt: pointer to the device tree blob
 427 *
 428 * Returns the number of entries in the device tree blob's memory
 429 * reservation map.  This does not include the terminating 0,0 entry
 430 * or any other (0,0) entries reserved for expansion.
 431 *
 432 * returns:
 433 *     the number of entries
 434 */
 435int fdt_num_mem_rsv(const void *fdt);
 436
 437/**
 438 * fdt_get_mem_rsv - retrieve one memory reserve map entry
 439 * @fdt: pointer to the device tree blob
 440 * @n: index of reserve map entry
 441 * @address: pointer to 64-bit variable to hold the start address
 442 * @size: pointer to 64-bit variable to hold the size of the entry
 443 *
 444 * On success, @address and @size will contain the address and size of
 445 * the n-th reserve map entry from the device tree blob, in
 446 * native-endian format.
 447 *
 448 * returns:
 449 *     0, on success
 450 *     -FDT_ERR_BADMAGIC,
 451 *     -FDT_ERR_BADVERSION,
 452 *     -FDT_ERR_BADSTATE, standard meanings
 453 */
 454int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size);
 455
 456/**
 457 * fdt_subnode_offset_namelen - find a subnode based on substring
 458 * @fdt: pointer to the device tree blob
 459 * @parentoffset: structure block offset of a node
 460 * @name: name of the subnode to locate
 461 * @namelen: number of characters of name to consider
 462 *
 463 * Identical to fdt_subnode_offset(), but only examine the first
 464 * namelen characters of name for matching the subnode name.  This is
 465 * useful for finding subnodes based on a portion of a larger string,
 466 * such as a full path.
 467 *
 468 * Return: offset of the subnode or -FDT_ERR_NOTFOUND if name not found.
 469 */
 470#ifndef SWIG /* Not available in Python */
 471int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
 472                               const char *name, int namelen);
 473#endif
 474/**
 475 * fdt_subnode_offset - find a subnode of a given node
 476 * @fdt: pointer to the device tree blob
 477 * @parentoffset: structure block offset of a node
 478 * @name: name of the subnode to locate
 479 *
 480 * fdt_subnode_offset() finds a subnode of the node at structure block
 481 * offset parentoffset with the given name.  name may include a unit
 482 * address, in which case fdt_subnode_offset() will find the subnode
 483 * with that unit address, or the unit address may be omitted, in
 484 * which case fdt_subnode_offset() will find an arbitrary subnode
 485 * whose name excluding unit address matches the given name.
 486 *
 487 * returns:
 488 *      structure block offset of the requested subnode (>=0), on success
 489 *      -FDT_ERR_NOTFOUND, if the requested subnode does not exist
 490 *      -FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE
 491 *              tag
 492 *      -FDT_ERR_BADMAGIC,
 493 *      -FDT_ERR_BADVERSION,
 494 *      -FDT_ERR_BADSTATE,
 495 *      -FDT_ERR_BADSTRUCTURE,
 496 *      -FDT_ERR_TRUNCATED, standard meanings.
 497 */
 498int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name);
 499
 500/**
 501 * fdt_path_offset_namelen - find a tree node by its full path
 502 * @fdt: pointer to the device tree blob
 503 * @path: full path of the node to locate
 504 * @namelen: number of characters of path to consider
 505 *
 506 * Identical to fdt_path_offset(), but only consider the first namelen
 507 * characters of path as the path name.
 508 *
 509 * Return: offset of the node or negative libfdt error value otherwise
 510 */
 511#ifndef SWIG /* Not available in Python */
 512int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen);
 513#endif
 514
 515/**
 516 * fdt_path_offset - find a tree node by its full path
 517 * @fdt: pointer to the device tree blob
 518 * @path: full path of the node to locate
 519 *
 520 * fdt_path_offset() finds a node of a given path in the device tree.
 521 * Each path component may omit the unit address portion, but the
 522 * results of this are undefined if any such path component is
 523 * ambiguous (that is if there are multiple nodes at the relevant
 524 * level matching the given component, differentiated only by unit
 525 * address).
 526 *
 527 * returns:
 528 *      structure block offset of the node with the requested path (>=0), on
 529 *              success
 530 *      -FDT_ERR_BADPATH, given path does not begin with '/' or is invalid
 531 *      -FDT_ERR_NOTFOUND, if the requested node does not exist
 532 *      -FDT_ERR_BADMAGIC,
 533 *      -FDT_ERR_BADVERSION,
 534 *      -FDT_ERR_BADSTATE,
 535 *      -FDT_ERR_BADSTRUCTURE,
 536 *      -FDT_ERR_TRUNCATED, standard meanings.
 537 */
 538int fdt_path_offset(const void *fdt, const char *path);
 539
 540/**
 541 * fdt_get_name - retrieve the name of a given node
 542 * @fdt: pointer to the device tree blob
 543 * @nodeoffset: structure block offset of the starting node
 544 * @lenp: pointer to an integer variable (will be overwritten) or NULL
 545 *
 546 * fdt_get_name() retrieves the name (including unit address) of the
 547 * device tree node at structure block offset nodeoffset.  If lenp is
 548 * non-NULL, the length of this name is also returned, in the integer
 549 * pointed to by lenp.
 550 *
 551 * returns:
 552 *      pointer to the node's name, on success
 553 *              If lenp is non-NULL, *lenp contains the length of that name
 554 *                      (>=0)
 555 *      NULL, on error
 556 *              if lenp is non-NULL *lenp contains an error code (<0):
 557 *              -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE
 558 *                      tag
 559 *              -FDT_ERR_BADMAGIC,
 560 *              -FDT_ERR_BADVERSION,
 561 *              -FDT_ERR_BADSTATE, standard meanings
 562 */
 563const char *fdt_get_name(const void *fdt, int nodeoffset, int *lenp);
 564
 565/**
 566 * fdt_first_property_offset - find the offset of a node's first property
 567 * @fdt: pointer to the device tree blob
 568 * @nodeoffset: structure block offset of a node
 569 *
 570 * fdt_first_property_offset() finds the first property of the node at
 571 * the given structure block offset.
 572 *
 573 * returns:
 574 *      structure block offset of the property (>=0), on success
 575 *      -FDT_ERR_NOTFOUND, if the requested node has no properties
 576 *      -FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_BEGIN_NODE tag
 577 *      -FDT_ERR_BADMAGIC,
 578 *      -FDT_ERR_BADVERSION,
 579 *      -FDT_ERR_BADSTATE,
 580 *      -FDT_ERR_BADSTRUCTURE,
 581 *      -FDT_ERR_TRUNCATED, standard meanings.
 582 */
 583int fdt_first_property_offset(const void *fdt, int nodeoffset);
 584
 585/**
 586 * fdt_next_property_offset - step through a node's properties
 587 * @fdt: pointer to the device tree blob
 588 * @offset: structure block offset of a property
 589 *
 590 * fdt_next_property_offset() finds the property immediately after the
 591 * one at the given structure block offset.  This will be a property
 592 * of the same node as the given property.
 593 *
 594 * returns:
 595 *      structure block offset of the next property (>=0), on success
 596 *      -FDT_ERR_NOTFOUND, if the given property is the last in its node
 597 *      -FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_PROP tag
 598 *      -FDT_ERR_BADMAGIC,
 599 *      -FDT_ERR_BADVERSION,
 600 *      -FDT_ERR_BADSTATE,
 601 *      -FDT_ERR_BADSTRUCTURE,
 602 *      -FDT_ERR_TRUNCATED, standard meanings.
 603 */
 604int fdt_next_property_offset(const void *fdt, int offset);
 605
 606/**
 607 * fdt_for_each_property_offset - iterate over all properties of a node
 608 *
 609 * @property:   property offset (int, lvalue)
 610 * @fdt:        FDT blob (const void *)
 611 * @node:       node offset (int)
 612 *
 613 * This is actually a wrapper around a for loop and would be used like so:
 614 *
 615 *      fdt_for_each_property_offset(property, fdt, node) {
 616 *              Use property
 617 *              ...
 618 *      }
 619 *
 620 *      if ((property < 0) && (property != -FDT_ERR_NOTFOUND)) {
 621 *              Error handling
 622 *      }
 623 *
 624 * Note that this is implemented as a macro and property is used as
 625 * iterator in the loop. The node variable can be constant or even a
 626 * literal.
 627 */
 628#define fdt_for_each_property_offset(property, fdt, node)       \
 629        for (property = fdt_first_property_offset(fdt, node);   \
 630             property >= 0;                                     \
 631             property = fdt_next_property_offset(fdt, property))
 632
 633/**
 634 * fdt_get_property_by_offset - retrieve the property at a given offset
 635 * @fdt: pointer to the device tree blob
 636 * @offset: offset of the property to retrieve
 637 * @lenp: pointer to an integer variable (will be overwritten) or NULL
 638 *
 639 * fdt_get_property_by_offset() retrieves a pointer to the
 640 * fdt_property structure within the device tree blob at the given
 641 * offset.  If lenp is non-NULL, the length of the property value is
 642 * also returned, in the integer pointed to by lenp.
 643 *
 644 * Note that this code only works on device tree versions >= 16. fdt_getprop()
 645 * works on all versions.
 646 *
 647 * returns:
 648 *      pointer to the structure representing the property
 649 *              if lenp is non-NULL, *lenp contains the length of the property
 650 *              value (>=0)
 651 *      NULL, on error
 652 *              if lenp is non-NULL, *lenp contains an error code (<0):
 653 *              -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
 654 *              -FDT_ERR_BADMAGIC,
 655 *              -FDT_ERR_BADVERSION,
 656 *              -FDT_ERR_BADSTATE,
 657 *              -FDT_ERR_BADSTRUCTURE,
 658 *              -FDT_ERR_TRUNCATED, standard meanings
 659 */
 660const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
 661                                                      int offset,
 662                                                      int *lenp);
 663
 664/**
 665 * fdt_get_property_namelen - find a property based on substring
 666 * @fdt: pointer to the device tree blob
 667 * @nodeoffset: offset of the node whose property to find
 668 * @name: name of the property to find
 669 * @namelen: number of characters of name to consider
 670 * @lenp: pointer to an integer variable (will be overwritten) or NULL
 671 *
 672 * Identical to fdt_get_property(), but only examine the first namelen
 673 * characters of name for matching the property name.
 674 *
 675 * Return: pointer to the structure representing the property, or NULL
 676 *         if not found
 677 */
 678#ifndef SWIG /* Not available in Python */
 679const struct fdt_property *fdt_get_property_namelen(const void *fdt,
 680                                                    int nodeoffset,
 681                                                    const char *name,
 682                                                    int namelen, int *lenp);
 683#endif
 684
 685/**
 686 * fdt_get_property - find a given property in a given node
 687 * @fdt: pointer to the device tree blob
 688 * @nodeoffset: offset of the node whose property to find
 689 * @name: name of the property to find
 690 * @lenp: pointer to an integer variable (will be overwritten) or NULL
 691 *
 692 * fdt_get_property() retrieves a pointer to the fdt_property
 693 * structure within the device tree blob corresponding to the property
 694 * named 'name' of the node at offset nodeoffset.  If lenp is
 695 * non-NULL, the length of the property value is also returned, in the
 696 * integer pointed to by lenp.
 697 *
 698 * returns:
 699 *      pointer to the structure representing the property
 700 *              if lenp is non-NULL, *lenp contains the length of the property
 701 *              value (>=0)
 702 *      NULL, on error
 703 *              if lenp is non-NULL, *lenp contains an error code (<0):
 704 *              -FDT_ERR_NOTFOUND, node does not have named property
 705 *              -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE
 706 *                      tag
 707 *              -FDT_ERR_BADMAGIC,
 708 *              -FDT_ERR_BADVERSION,
 709 *              -FDT_ERR_BADSTATE,
 710 *              -FDT_ERR_BADSTRUCTURE,
 711 *              -FDT_ERR_TRUNCATED, standard meanings
 712 */
 713const struct fdt_property *fdt_get_property(const void *fdt, int nodeoffset,
 714                                            const char *name, int *lenp);
 715static inline struct fdt_property *fdt_get_property_w(void *fdt, int nodeoffset,
 716                                                      const char *name,
 717                                                      int *lenp)
 718{
 719        return (struct fdt_property *)(uintptr_t)
 720                fdt_get_property(fdt, nodeoffset, name, lenp);
 721}
 722
 723/**
 724 * fdt_getprop_by_offset - retrieve the value of a property at a given offset
 725 * @fdt: pointer to the device tree blob
 726 * @offset: offset of the property to read
 727 * @namep: pointer to a string variable (will be overwritten) or NULL
 728 * @lenp: pointer to an integer variable (will be overwritten) or NULL
 729 *
 730 * fdt_getprop_by_offset() retrieves a pointer to the value of the
 731 * property at structure block offset 'offset' (this will be a pointer
 732 * to within the device blob itself, not a copy of the value).  If
 733 * lenp is non-NULL, the length of the property value is also
 734 * returned, in the integer pointed to by lenp.  If namep is non-NULL,
 735 * the property's namne will also be returned in the char * pointed to
 736 * by namep (this will be a pointer to within the device tree's string
 737 * block, not a new copy of the name).
 738 *
 739 * returns:
 740 *      pointer to the property's value
 741 *              if lenp is non-NULL, *lenp contains the length of the property
 742 *              value (>=0)
 743 *              if namep is non-NULL *namep contiains a pointer to the property
 744 *              name.
 745 *      NULL, on error
 746 *              if lenp is non-NULL, *lenp contains an error code (<0):
 747 *              -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
 748 *              -FDT_ERR_BADMAGIC,
 749 *              -FDT_ERR_BADVERSION,
 750 *              -FDT_ERR_BADSTATE,
 751 *              -FDT_ERR_BADSTRUCTURE,
 752 *              -FDT_ERR_TRUNCATED, standard meanings
 753 */
 754#ifndef SWIG /* This function is not useful in Python */
 755const void *fdt_getprop_by_offset(const void *fdt, int offset,
 756                                  const char **namep, int *lenp);
 757#endif
 758
 759/**
 760 * fdt_getprop_namelen - get property value based on substring
 761 * @fdt: pointer to the device tree blob
 762 * @nodeoffset: offset of the node whose property to find
 763 * @name: name of the property to find
 764 * @namelen: number of characters of name to consider
 765 * @lenp: pointer to an integer variable (will be overwritten) or NULL
 766 *
 767 * Identical to fdt_getprop(), but only examine the first namelen
 768 * characters of name for matching the property name.
 769 *
 770 * Return: pointer to the property's value or NULL on error
 771 */
 772#ifndef SWIG /* Not available in Python */
 773const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
 774                                const char *name, int namelen, int *lenp);
 775static inline void *fdt_getprop_namelen_w(void *fdt, int nodeoffset,
 776                                          const char *name, int namelen,
 777                                          int *lenp)
 778{
 779        return (void *)(uintptr_t)fdt_getprop_namelen(fdt, nodeoffset, name,
 780                                                      namelen, lenp);
 781}
 782#endif
 783
 784/**
 785 * fdt_getprop - retrieve the value of a given property
 786 * @fdt: pointer to the device tree blob
 787 * @nodeoffset: offset of the node whose property to find
 788 * @name: name of the property to find
 789 * @lenp: pointer to an integer variable (will be overwritten) or NULL
 790 *
 791 * fdt_getprop() retrieves a pointer to the value of the property
 792 * named @name of the node at offset @nodeoffset (this will be a
 793 * pointer to within the device blob itself, not a copy of the value).
 794 * If @lenp is non-NULL, the length of the property value is also
 795 * returned, in the integer pointed to by @lenp.
 796 *
 797 * returns:
 798 *      pointer to the property's value
 799 *              if lenp is non-NULL, *lenp contains the length of the property
 800 *              value (>=0)
 801 *      NULL, on error
 802 *              if lenp is non-NULL, *lenp contains an error code (<0):
 803 *              -FDT_ERR_NOTFOUND, node does not have named property
 804 *              -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE
 805 *                      tag
 806 *              -FDT_ERR_BADMAGIC,
 807 *              -FDT_ERR_BADVERSION,
 808 *              -FDT_ERR_BADSTATE,
 809 *              -FDT_ERR_BADSTRUCTURE,
 810 *              -FDT_ERR_TRUNCATED, standard meanings
 811 */
 812const void *fdt_getprop(const void *fdt, int nodeoffset,
 813                        const char *name, int *lenp);
 814static inline void *fdt_getprop_w(void *fdt, int nodeoffset,
 815                                  const char *name, int *lenp)
 816{
 817        return (void *)(uintptr_t)fdt_getprop(fdt, nodeoffset, name, lenp);
 818}
 819
 820/**
 821 * fdt_get_phandle - retrieve the phandle of a given node
 822 * @fdt: pointer to the device tree blob
 823 * @nodeoffset: structure block offset of the node
 824 *
 825 * fdt_get_phandle() retrieves the phandle of the device tree node at
 826 * structure block offset nodeoffset.
 827 *
 828 * returns:
 829 *      the phandle of the node at nodeoffset, on success (!= 0, != -1)
 830 *      0, if the node has no phandle, or another error occurs
 831 */
 832uint32_t fdt_get_phandle(const void *fdt, int nodeoffset);
 833
 834/**
 835 * fdt_get_alias_namelen - get alias based on substring
 836 * @fdt: pointer to the device tree blob
 837 * @name: name of the alias th look up
 838 * @namelen: number of characters of name to consider
 839 *
 840 * Identical to fdt_get_alias(), but only examine the first @namelen
 841 * characters of @name for matching the alias name.
 842 *
 843 * Return: a pointer to the expansion of the alias named @name, if it exists,
 844 *         NULL otherwise
 845 */
 846#ifndef SWIG /* Not available in Python */
 847const char *fdt_get_alias_namelen(const void *fdt,
 848                                  const char *name, int namelen);
 849#endif
 850
 851/**
 852 * fdt_get_alias - retrieve the path referenced by a given alias
 853 * @fdt: pointer to the device tree blob
 854 * @name: name of the alias th look up
 855 *
 856 * fdt_get_alias() retrieves the value of a given alias.  That is, the
 857 * value of the property named @name in the node /aliases.
 858 *
 859 * returns:
 860 *      a pointer to the expansion of the alias named 'name', if it exists
 861 *      NULL, if the given alias or the /aliases node does not exist
 862 */
 863const char *fdt_get_alias(const void *fdt, const char *name);
 864
 865/**
 866 * fdt_get_path - determine the full path of a node
 867 * @fdt: pointer to the device tree blob
 868 * @nodeoffset: offset of the node whose path to find
 869 * @buf: character buffer to contain the returned path (will be overwritten)
 870 * @buflen: size of the character buffer at buf
 871 *
 872 * fdt_get_path() computes the full path of the node at offset
 873 * nodeoffset, and records that path in the buffer at buf.
 874 *
 875 * NOTE: This function is expensive, as it must scan the device tree
 876 * structure from the start to nodeoffset.
 877 *
 878 * returns:
 879 *      0, on success
 880 *              buf contains the absolute path of the node at
 881 *              nodeoffset, as a NUL-terminated string.
 882 *      -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 883 *      -FDT_ERR_NOSPACE, the path of the given node is longer than (bufsize-1)
 884 *              characters and will not fit in the given buffer.
 885 *      -FDT_ERR_BADMAGIC,
 886 *      -FDT_ERR_BADVERSION,
 887 *      -FDT_ERR_BADSTATE,
 888 *      -FDT_ERR_BADSTRUCTURE, standard meanings
 889 */
 890int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen);
 891
 892/**
 893 * fdt_supernode_atdepth_offset - find a specific ancestor of a node
 894 * @fdt: pointer to the device tree blob
 895 * @nodeoffset: offset of the node whose parent to find
 896 * @supernodedepth: depth of the ancestor to find
 897 * @nodedepth: pointer to an integer variable (will be overwritten) or NULL
 898 *
 899 * fdt_supernode_atdepth_offset() finds an ancestor of the given node
 900 * at a specific depth from the root (where the root itself has depth
 901 * 0, its immediate subnodes depth 1 and so forth).  So
 902 *      fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, NULL);
 903 * will always return 0, the offset of the root node.  If the node at
 904 * nodeoffset has depth D, then:
 905 *      fdt_supernode_atdepth_offset(fdt, nodeoffset, D, NULL);
 906 * will return nodeoffset itself.
 907 *
 908 * NOTE: This function is expensive, as it must scan the device tree
 909 * structure from the start to nodeoffset.
 910 *
 911 * returns:
 912 *      structure block offset of the node at node offset's ancestor
 913 *              of depth supernodedepth (>=0), on success
 914 *      -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 915 *      -FDT_ERR_NOTFOUND, supernodedepth was greater than the depth of
 916 *              nodeoffset
 917 *      -FDT_ERR_BADMAGIC,
 918 *      -FDT_ERR_BADVERSION,
 919 *      -FDT_ERR_BADSTATE,
 920 *      -FDT_ERR_BADSTRUCTURE, standard meanings
 921 */
 922int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
 923                                 int supernodedepth, int *nodedepth);
 924
 925/**
 926 * fdt_node_depth - find the depth of a given node
 927 * @fdt: pointer to the device tree blob
 928 * @nodeoffset: offset of the node whose parent to find
 929 *
 930 * fdt_node_depth() finds the depth of a given node.  The root node
 931 * has depth 0, its immediate subnodes depth 1 and so forth.
 932 *
 933 * NOTE: This function is expensive, as it must scan the device tree
 934 * structure from the start to nodeoffset.
 935 *
 936 * returns:
 937 *      depth of the node at nodeoffset (>=0), on success
 938 *      -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 939 *      -FDT_ERR_BADMAGIC,
 940 *      -FDT_ERR_BADVERSION,
 941 *      -FDT_ERR_BADSTATE,
 942 *      -FDT_ERR_BADSTRUCTURE, standard meanings
 943 */
 944int fdt_node_depth(const void *fdt, int nodeoffset);
 945
 946/**
 947 * fdt_parent_offset - find the parent of a given node
 948 * @fdt: pointer to the device tree blob
 949 * @nodeoffset: offset of the node whose parent to find
 950 *
 951 * fdt_parent_offset() locates the parent node of a given node (that
 952 * is, it finds the offset of the node which contains the node at
 953 * nodeoffset as a subnode).
 954 *
 955 * NOTE: This function is expensive, as it must scan the device tree
 956 * structure from the start to nodeoffset, *twice*.
 957 *
 958 * returns:
 959 *      structure block offset of the parent of the node at nodeoffset
 960 *              (>=0), on success
 961 *      -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 962 *      -FDT_ERR_BADMAGIC,
 963 *      -FDT_ERR_BADVERSION,
 964 *      -FDT_ERR_BADSTATE,
 965 *      -FDT_ERR_BADSTRUCTURE, standard meanings
 966 */
 967int fdt_parent_offset(const void *fdt, int nodeoffset);
 968
 969/**
 970 * fdt_node_offset_by_prop_value - find nodes with a given property value
 971 * @fdt: pointer to the device tree blob
 972 * @startoffset: only find nodes after this offset
 973 * @propname: property name to check
 974 * @propval: property value to search for
 975 * @proplen: length of the value in propval
 976 *
 977 * fdt_node_offset_by_prop_value() returns the offset of the first
 978 * node after startoffset, which has a property named propname whose
 979 * value is of length proplen and has value equal to propval; or if
 980 * startoffset is -1, the very first such node in the tree.
 981 *
 982 * To iterate through all nodes matching the criterion, the following
 983 * idiom can be used:
 984 *      offset = fdt_node_offset_by_prop_value(fdt, -1, propname,
 985 *                                             propval, proplen);
 986 *      while (offset != -FDT_ERR_NOTFOUND) {
 987 *              // other code here
 988 *              offset = fdt_node_offset_by_prop_value(fdt, offset, propname,
 989 *                                                     propval, proplen);
 990 *      }
 991 *
 992 * Note the -1 in the first call to the function, if 0 is used here
 993 * instead, the function will never locate the root node, even if it
 994 * matches the criterion.
 995 *
 996 * returns:
 997 *      structure block offset of the located node (>= 0, >startoffset),
 998 *               on success
 999 *      -FDT_ERR_NOTFOUND, no node matching the criterion exists in the
1000 *              tree after startoffset
1001 *      -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
1002 *      -FDT_ERR_BADMAGIC,
1003 *      -FDT_ERR_BADVERSION,
1004 *      -FDT_ERR_BADSTATE,
1005 *      -FDT_ERR_BADSTRUCTURE, standard meanings
1006 */
1007int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
1008                                  const char *propname,
1009                                  const void *propval, int proplen);
1010
1011/**
1012 * fdt_node_offset_by_phandle - find the node with a given phandle
1013 * @fdt: pointer to the device tree blob
1014 * @phandle: phandle value
1015 *
1016 * fdt_node_offset_by_phandle() returns the offset of the node
1017 * which has the given phandle value.  If there is more than one node
1018 * in the tree with the given phandle (an invalid tree), results are
1019 * undefined.
1020 *
1021 * returns:
1022 *      structure block offset of the located node (>= 0), on success
1023 *      -FDT_ERR_NOTFOUND, no node with that phandle exists
1024 *      -FDT_ERR_BADPHANDLE, given phandle value was invalid (0 or -1)
1025 *      -FDT_ERR_BADMAGIC,
1026 *      -FDT_ERR_BADVERSION,
1027 *      -FDT_ERR_BADSTATE,
1028 *      -FDT_ERR_BADSTRUCTURE, standard meanings
1029 */
1030int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle);
1031
1032/**
1033 * fdt_node_check_compatible - check a node's compatible property
1034 * @fdt: pointer to the device tree blob
1035 * @nodeoffset: offset of a tree node
1036 * @compatible: string to match against
1037 *
1038 * fdt_node_check_compatible() returns 0 if the given node contains a
1039 * @compatible property with the given string as one of its elements,
1040 * it returns non-zero otherwise, or on error.
1041 *
1042 * returns:
1043 *      0, if the node has a 'compatible' property listing the given string
1044 *      1, if the node has a 'compatible' property, but it does not list
1045 *              the given string
1046 *      -FDT_ERR_NOTFOUND, if the given node has no 'compatible' property
1047 *      -FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag
1048 *      -FDT_ERR_BADMAGIC,
1049 *      -FDT_ERR_BADVERSION,
1050 *      -FDT_ERR_BADSTATE,
1051 *      -FDT_ERR_BADSTRUCTURE, standard meanings
1052 */
1053int fdt_node_check_compatible(const void *fdt, int nodeoffset,
1054                              const char *compatible);
1055
1056/**
1057 * fdt_node_offset_by_compatible - find nodes with a given 'compatible' value
1058 * @fdt: pointer to the device tree blob
1059 * @startoffset: only find nodes after this offset
1060 * @compatible: 'compatible' string to match against
1061 *
1062 * fdt_node_offset_by_compatible() returns the offset of the first
1063 * node after startoffset, which has a 'compatible' property which
1064 * lists the given compatible string; or if startoffset is -1, the
1065 * very first such node in the tree.
1066 *
1067 * To iterate through all nodes matching the criterion, the following
1068 * idiom can be used:
1069 *      offset = fdt_node_offset_by_compatible(fdt, -1, compatible);
1070 *      while (offset != -FDT_ERR_NOTFOUND) {
1071 *              // other code here
1072 *              offset = fdt_node_offset_by_compatible(fdt, offset, compatible);
1073 *      }
1074 *
1075 * Note the -1 in the first call to the function, if 0 is used here
1076 * instead, the function will never locate the root node, even if it
1077 * matches the criterion.
1078 *
1079 * returns:
1080 *      structure block offset of the located node (>= 0, >startoffset),
1081 *               on success
1082 *      -FDT_ERR_NOTFOUND, no node matching the criterion exists in the
1083 *              tree after startoffset
1084 *      -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
1085 *      -FDT_ERR_BADMAGIC,
1086 *      -FDT_ERR_BADVERSION,
1087 *      -FDT_ERR_BADSTATE,
1088 *      -FDT_ERR_BADSTRUCTURE, standard meanings
1089 */
1090int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
1091                                  const char *compatible);
1092
1093/**
1094 * fdt_stringlist_contains - check a string list property for a string
1095 * @strlist: Property containing a list of strings to check
1096 * @listlen: Length of property
1097 * @str: String to search for
1098 *
1099 * This is a utility function provided for convenience. The list contains
1100 * one or more strings, each terminated by \0, as is found in a device tree
1101 * "compatible" property.
1102 *
1103 * Return: 1 if the string is found in the list, 0 not found, or invalid list
1104 */
1105int fdt_stringlist_contains(const char *strlist, int listlen, const char *str);
1106
1107/**
1108 * fdt_stringlist_count - count the number of strings in a string list
1109 * @fdt: pointer to the device tree blob
1110 * @nodeoffset: offset of a tree node
1111 * @property: name of the property containing the string list
1112 *
1113 * Return:
1114 *   the number of strings in the given property
1115 *   -FDT_ERR_BADVALUE if the property value is not NUL-terminated
1116 *   -FDT_ERR_NOTFOUND if the property does not exist
1117 */
1118int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property);
1119
1120/**
1121 * fdt_stringlist_search - find a string in a string list and return its index
1122 * @fdt: pointer to the device tree blob
1123 * @nodeoffset: offset of a tree node
1124 * @property: name of the property containing the string list
1125 * @string: string to look up in the string list
1126 *
1127 * Note that it is possible for this function to succeed on property values
1128 * that are not NUL-terminated. That's because the function will stop after
1129 * finding the first occurrence of @string. This can for example happen with
1130 * small-valued cell properties, such as #address-cells, when searching for
1131 * the empty string.
1132 *
1133 * return:
1134 *   the index of the string in the list of strings
1135 *   -FDT_ERR_BADVALUE if the property value is not NUL-terminated
1136 *   -FDT_ERR_NOTFOUND if the property does not exist or does not contain
1137 *                     the given string
1138 */
1139int fdt_stringlist_search(const void *fdt, int nodeoffset, const char *property,
1140                          const char *string);
1141
1142/**
1143 * fdt_stringlist_get() - obtain the string at a given index in a string list
1144 * @fdt: pointer to the device tree blob
1145 * @nodeoffset: offset of a tree node
1146 * @property: name of the property containing the string list
1147 * @index: index of the string to return
1148 * @lenp: return location for the string length or an error code on failure
1149 *
1150 * Note that this will successfully extract strings from properties with
1151 * non-NUL-terminated values. For example on small-valued cell properties
1152 * this function will return the empty string.
1153 *
1154 * If non-NULL, the length of the string (on success) or a negative error-code
1155 * (on failure) will be stored in the integer pointer to by lenp.
1156 *
1157 * Return:
1158 *   A pointer to the string at the given index in the string list or NULL on
1159 *   failure. On success the length of the string will be stored in the memory
1160 *   location pointed to by the lenp parameter, if non-NULL. On failure one of
1161 *   the following negative error codes will be returned in the lenp parameter
1162 *   (if non-NULL):
1163 *     -FDT_ERR_BADVALUE if the property value is not NUL-terminated
1164 *     -FDT_ERR_NOTFOUND if the property does not exist
1165 */
1166const char *fdt_stringlist_get(const void *fdt, int nodeoffset,
1167                               const char *property, int index,
1168                               int *lenp);
1169
1170/**********************************************************************/
1171/* Read-only functions (addressing related)                           */
1172/**********************************************************************/
1173
1174/**
1175 * FDT_MAX_NCELLS - maximum value for #address-cells and #size-cells
1176 *
1177 * This is the maximum value for #address-cells, #size-cells and
1178 * similar properties that will be processed by libfdt.  IEE1275
1179 * requires that OF implementations handle values up to 4.
1180 * Implementations may support larger values, but in practice higher
1181 * values aren't used.
1182 */
1183#define FDT_MAX_NCELLS          4
1184
1185/**
1186 * fdt_address_cells - retrieve address size for a bus represented in the tree
1187 * @fdt: pointer to the device tree blob
1188 * @nodeoffset: offset of the node to find the address size for
1189 *
1190 * When the node has a valid #address-cells property, returns its value.
1191 *
1192 * returns:
1193 *      0 <= n < FDT_MAX_NCELLS, on success
1194 *      2, if the node has no #address-cells property
1195 *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
1196 *              #address-cells property
1197 *      -FDT_ERR_BADMAGIC,
1198 *      -FDT_ERR_BADVERSION,
1199 *      -FDT_ERR_BADSTATE,
1200 *      -FDT_ERR_BADSTRUCTURE,
1201 *      -FDT_ERR_TRUNCATED, standard meanings
1202 */
1203int fdt_address_cells(const void *fdt, int nodeoffset);
1204
1205/**
1206 * fdt_size_cells - retrieve address range size for a bus represented in the
1207 *                  tree
1208 * @fdt: pointer to the device tree blob
1209 * @nodeoffset: offset of the node to find the address range size for
1210 *
1211 * When the node has a valid #size-cells property, returns its value.
1212 *
1213 * returns:
1214 *      0 <= n < FDT_MAX_NCELLS, on success
1215 *      1, if the node has no #size-cells property
1216 *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
1217 *              #size-cells property
1218 *      -FDT_ERR_BADMAGIC,
1219 *      -FDT_ERR_BADVERSION,
1220 *      -FDT_ERR_BADSTATE,
1221 *      -FDT_ERR_BADSTRUCTURE,
1222 *      -FDT_ERR_TRUNCATED, standard meanings
1223 */
1224int fdt_size_cells(const void *fdt, int nodeoffset);
1225
1226
1227/**********************************************************************/
1228/* Write-in-place functions                                           */
1229/**********************************************************************/
1230
1231/**
1232 * fdt_setprop_inplace_namelen_partial - change a property's value,
1233 *                                       but not its size
1234 * @fdt: pointer to the device tree blob
1235 * @nodeoffset: offset of the node whose property to change
1236 * @name: name of the property to change
1237 * @namelen: number of characters of name to consider
1238 * @idx: index of the property to change in the array
1239 * @val: pointer to data to replace the property value with
1240 * @len: length of the property value
1241 *
1242 * Identical to fdt_setprop_inplace(), but modifies the given property
1243 * starting from the given index, and using only the first characters
1244 * of the name. It is useful when you want to manipulate only one value of
1245 * an array and you have a string that doesn't end with \0.
1246 *
1247 * Return: 0 on success, negative libfdt error value otherwise
1248 */
1249#ifndef SWIG /* Not available in Python */
1250int fdt_setprop_inplace_namelen_partial(void *fdt, int nodeoffset,
1251                                        const char *name, int namelen,
1252                                        uint32_t idx, const void *val,
1253                                        int len);
1254#endif
1255
1256/**
1257 * fdt_setprop_inplace - change a property's value, but not its size
1258 * @fdt: pointer to the device tree blob
1259 * @nodeoffset: offset of the node whose property to change
1260 * @name: name of the property to change
1261 * @val: pointer to data to replace the property value with
1262 * @len: length of the property value
1263 *
1264 * fdt_setprop_inplace() replaces the value of a given property with
1265 * the data in val, of length len.  This function cannot change the
1266 * size of a property, and so will only work if len is equal to the
1267 * current length of the property.
1268 *
1269 * This function will alter only the bytes in the blob which contain
1270 * the given property value, and will not alter or move any other part
1271 * of the tree.
1272 *
1273 * returns:
1274 *      0, on success
1275 *      -FDT_ERR_NOSPACE, if len is not equal to the property's current length
1276 *      -FDT_ERR_NOTFOUND, node does not have the named property
1277 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1278 *      -FDT_ERR_BADMAGIC,
1279 *      -FDT_ERR_BADVERSION,
1280 *      -FDT_ERR_BADSTATE,
1281 *      -FDT_ERR_BADSTRUCTURE,
1282 *      -FDT_ERR_TRUNCATED, standard meanings
1283 */
1284#ifndef SWIG /* Not available in Python */
1285int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
1286                        const void *val, int len);
1287#endif
1288
1289/**
1290 * fdt_setprop_inplace_u32 - change the value of a 32-bit integer property
1291 * @fdt: pointer to the device tree blob
1292 * @nodeoffset: offset of the node whose property to change
1293 * @name: name of the property to change
1294 * @val: 32-bit integer value to replace the property with
1295 *
1296 * fdt_setprop_inplace_u32() replaces the value of a given property
1297 * with the 32-bit integer value in val, converting val to big-endian
1298 * if necessary.  This function cannot change the size of a property,
1299 * and so will only work if the property already exists and has length
1300 * 4.
1301 *
1302 * This function will alter only the bytes in the blob which contain
1303 * the given property value, and will not alter or move any other part
1304 * of the tree.
1305 *
1306 * returns:
1307 *      0, on success
1308 *      -FDT_ERR_NOSPACE, if the property's length is not equal to 4
1309 *      -FDT_ERR_NOTFOUND, node does not have the named property
1310 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1311 *      -FDT_ERR_BADMAGIC,
1312 *      -FDT_ERR_BADVERSION,
1313 *      -FDT_ERR_BADSTATE,
1314 *      -FDT_ERR_BADSTRUCTURE,
1315 *      -FDT_ERR_TRUNCATED, standard meanings
1316 */
1317static inline int fdt_setprop_inplace_u32(void *fdt, int nodeoffset,
1318                                          const char *name, uint32_t val)
1319{
1320        fdt32_t tmp = cpu_to_fdt32(val);
1321        return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1322}
1323
1324/**
1325 * fdt_setprop_inplace_u64 - change the value of a 64-bit integer property
1326 * @fdt: pointer to the device tree blob
1327 * @nodeoffset: offset of the node whose property to change
1328 * @name: name of the property to change
1329 * @val: 64-bit integer value to replace the property with
1330 *
1331 * fdt_setprop_inplace_u64() replaces the value of a given property
1332 * with the 64-bit integer value in val, converting val to big-endian
1333 * if necessary.  This function cannot change the size of a property,
1334 * and so will only work if the property already exists and has length
1335 * 8.
1336 *
1337 * This function will alter only the bytes in the blob which contain
1338 * the given property value, and will not alter or move any other part
1339 * of the tree.
1340 *
1341 * returns:
1342 *      0, on success
1343 *      -FDT_ERR_NOSPACE, if the property's length is not equal to 8
1344 *      -FDT_ERR_NOTFOUND, node does not have the named property
1345 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1346 *      -FDT_ERR_BADMAGIC,
1347 *      -FDT_ERR_BADVERSION,
1348 *      -FDT_ERR_BADSTATE,
1349 *      -FDT_ERR_BADSTRUCTURE,
1350 *      -FDT_ERR_TRUNCATED, standard meanings
1351 */
1352static inline int fdt_setprop_inplace_u64(void *fdt, int nodeoffset,
1353                                          const char *name, uint64_t val)
1354{
1355        fdt64_t tmp = cpu_to_fdt64(val);
1356        return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1357}
1358
1359/**
1360 * fdt_setprop_inplace_cell - change the value of a single-cell property
1361 * @fdt: pointer to the device tree blob
1362 * @nodeoffset: offset of the node containing the property
1363 * @name: name of the property to change the value of
1364 * @val: new value of the 32-bit cell
1365 *
1366 * This is an alternative name for fdt_setprop_inplace_u32()
1367 * Return: 0 on success, negative libfdt error number otherwise.
1368 */
1369static inline int fdt_setprop_inplace_cell(void *fdt, int nodeoffset,
1370                                           const char *name, uint32_t val)
1371{
1372        return fdt_setprop_inplace_u32(fdt, nodeoffset, name, val);
1373}
1374
1375/**
1376 * fdt_nop_property - replace a property with nop tags
1377 * @fdt: pointer to the device tree blob
1378 * @nodeoffset: offset of the node whose property to nop
1379 * @name: name of the property to nop
1380 *
1381 * fdt_nop_property() will replace a given property's representation
1382 * in the blob with FDT_NOP tags, effectively removing it from the
1383 * tree.
1384 *
1385 * This function will alter only the bytes in the blob which contain
1386 * the property, and will not alter or move any other part of the
1387 * tree.
1388 *
1389 * returns:
1390 *      0, on success
1391 *      -FDT_ERR_NOTFOUND, node does not have the named property
1392 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1393 *      -FDT_ERR_BADMAGIC,
1394 *      -FDT_ERR_BADVERSION,
1395 *      -FDT_ERR_BADSTATE,
1396 *      -FDT_ERR_BADSTRUCTURE,
1397 *      -FDT_ERR_TRUNCATED, standard meanings
1398 */
1399int fdt_nop_property(void *fdt, int nodeoffset, const char *name);
1400
1401/**
1402 * fdt_nop_node - replace a node (subtree) with nop tags
1403 * @fdt: pointer to the device tree blob
1404 * @nodeoffset: offset of the node to nop
1405 *
1406 * fdt_nop_node() will replace a given node's representation in the
1407 * blob, including all its subnodes, if any, with FDT_NOP tags,
1408 * effectively removing it from the tree.
1409 *
1410 * This function will alter only the bytes in the blob which contain
1411 * the node and its properties and subnodes, and will not alter or
1412 * move any other part of the tree.
1413 *
1414 * returns:
1415 *      0, on success
1416 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1417 *      -FDT_ERR_BADMAGIC,
1418 *      -FDT_ERR_BADVERSION,
1419 *      -FDT_ERR_BADSTATE,
1420 *      -FDT_ERR_BADSTRUCTURE,
1421 *      -FDT_ERR_TRUNCATED, standard meanings
1422 */
1423int fdt_nop_node(void *fdt, int nodeoffset);
1424
1425/**********************************************************************/
1426/* Sequential write functions                                         */
1427/**********************************************************************/
1428
1429/* fdt_create_with_flags flags */
1430#define FDT_CREATE_FLAG_NO_NAME_DEDUP 0x1
1431        /* FDT_CREATE_FLAG_NO_NAME_DEDUP: Do not try to de-duplicate property
1432         * names in the fdt. This can result in faster creation times, but
1433         * a larger fdt. */
1434
1435#define FDT_CREATE_FLAGS_ALL    (FDT_CREATE_FLAG_NO_NAME_DEDUP)
1436
1437/**
1438 * fdt_create_with_flags - begin creation of a new fdt
1439 * @buf: pointer to memory allocated where fdt will be created
1440 * @bufsize: size of the memory space at fdt
1441 * @flags: a valid combination of FDT_CREATE_FLAG_ flags, or 0.
1442 *
1443 * fdt_create_with_flags() begins the process of creating a new fdt with
1444 * the sequential write interface.
1445 *
1446 * fdt creation process must end with fdt_finished() to produce a valid fdt.
1447 *
1448 * returns:
1449 *      0, on success
1450 *      -FDT_ERR_NOSPACE, bufsize is insufficient for a minimal fdt
1451 *      -FDT_ERR_BADFLAGS, flags is not valid
1452 */
1453int fdt_create_with_flags(void *buf, int bufsize, uint32_t flags);
1454
1455/**
1456 * fdt_create - begin creation of a new fdt
1457 * @buf: pointer to memory allocated where fdt will be created
1458 * @bufsize: size of the memory space at fdt
1459 *
1460 * fdt_create() is equivalent to fdt_create_with_flags() with flags=0.
1461 *
1462 * returns:
1463 *      0, on success
1464 *      -FDT_ERR_NOSPACE, bufsize is insufficient for a minimal fdt
1465 */
1466int fdt_create(void *buf, int bufsize);
1467
1468int fdt_resize(void *fdt, void *buf, int bufsize);
1469int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size);
1470int fdt_finish_reservemap(void *fdt);
1471int fdt_begin_node(void *fdt, const char *name);
1472int fdt_property(void *fdt, const char *name, const void *val, int len);
1473static inline int fdt_property_u32(void *fdt, const char *name, uint32_t val)
1474{
1475        fdt32_t tmp = cpu_to_fdt32(val);
1476        return fdt_property(fdt, name, &tmp, sizeof(tmp));
1477}
1478static inline int fdt_property_u64(void *fdt, const char *name, uint64_t val)
1479{
1480        fdt64_t tmp = cpu_to_fdt64(val);
1481        return fdt_property(fdt, name, &tmp, sizeof(tmp));
1482}
1483
1484#ifndef SWIG /* Not available in Python */
1485static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val)
1486{
1487        return fdt_property_u32(fdt, name, val);
1488}
1489#endif
1490
1491/**
1492 * fdt_property_placeholder - add a new property and return a ptr to its value
1493 *
1494 * @fdt: pointer to the device tree blob
1495 * @name: name of property to add
1496 * @len: length of property value in bytes
1497 * @valp: returns a pointer to where where the value should be placed
1498 *
1499 * returns:
1500 *      0, on success
1501 *      -FDT_ERR_BADMAGIC,
1502 *      -FDT_ERR_NOSPACE, standard meanings
1503 */
1504int fdt_property_placeholder(void *fdt, const char *name, int len, void **valp);
1505
1506#define fdt_property_string(fdt, name, str) \
1507        fdt_property(fdt, name, str, strlen(str)+1)
1508int fdt_end_node(void *fdt);
1509int fdt_finish(void *fdt);
1510
1511/**********************************************************************/
1512/* Read-write functions                                               */
1513/**********************************************************************/
1514
1515int fdt_create_empty_tree(void *buf, int bufsize);
1516int fdt_open_into(const void *fdt, void *buf, int bufsize);
1517int fdt_pack(void *fdt);
1518
1519/**
1520 * fdt_add_mem_rsv - add one memory reserve map entry
1521 * @fdt: pointer to the device tree blob
1522 * @address: 64-bit start address of the reserve map entry
1523 * @size: 64-bit size of the reserved region
1524 *
1525 * Adds a reserve map entry to the given blob reserving a region at
1526 * address address of length size.
1527 *
1528 * This function will insert data into the reserve map and will
1529 * therefore change the indexes of some entries in the table.
1530 *
1531 * returns:
1532 *      0, on success
1533 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1534 *              contain the new reservation entry
1535 *      -FDT_ERR_BADMAGIC,
1536 *      -FDT_ERR_BADVERSION,
1537 *      -FDT_ERR_BADSTATE,
1538 *      -FDT_ERR_BADSTRUCTURE,
1539 *      -FDT_ERR_BADLAYOUT,
1540 *      -FDT_ERR_TRUNCATED, standard meanings
1541 */
1542int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size);
1543
1544/**
1545 * fdt_del_mem_rsv - remove a memory reserve map entry
1546 * @fdt: pointer to the device tree blob
1547 * @n: entry to remove
1548 *
1549 * fdt_del_mem_rsv() removes the n-th memory reserve map entry from
1550 * the blob.
1551 *
1552 * This function will delete data from the reservation table and will
1553 * therefore change the indexes of some entries in the table.
1554 *
1555 * returns:
1556 *      0, on success
1557 *      -FDT_ERR_NOTFOUND, there is no entry of the given index (i.e. there
1558 *              are less than n+1 reserve map entries)
1559 *      -FDT_ERR_BADMAGIC,
1560 *      -FDT_ERR_BADVERSION,
1561 *      -FDT_ERR_BADSTATE,
1562 *      -FDT_ERR_BADSTRUCTURE,
1563 *      -FDT_ERR_BADLAYOUT,
1564 *      -FDT_ERR_TRUNCATED, standard meanings
1565 */
1566int fdt_del_mem_rsv(void *fdt, int n);
1567
1568/**
1569 * fdt_set_name - change the name of a given node
1570 * @fdt: pointer to the device tree blob
1571 * @nodeoffset: structure block offset of a node
1572 * @name: name to give the node
1573 *
1574 * fdt_set_name() replaces the name (including unit address, if any)
1575 * of the given node with the given string.  NOTE: this function can't
1576 * efficiently check if the new name is unique amongst the given
1577 * node's siblings; results are undefined if this function is invoked
1578 * with a name equal to one of the given node's siblings.
1579 *
1580 * This function may insert or delete data from the blob, and will
1581 * therefore change the offsets of some existing nodes.
1582 *
1583 * returns:
1584 *      0, on success
1585 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob
1586 *              to contain the new name
1587 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1588 *      -FDT_ERR_BADMAGIC,
1589 *      -FDT_ERR_BADVERSION,
1590 *      -FDT_ERR_BADSTATE, standard meanings
1591 */
1592int fdt_set_name(void *fdt, int nodeoffset, const char *name);
1593
1594/**
1595 * fdt_setprop - create or change a property
1596 * @fdt: pointer to the device tree blob
1597 * @nodeoffset: offset of the node whose property to change
1598 * @name: name of the property to change
1599 * @val: pointer to data to set the property value to
1600 * @len: length of the property value
1601 *
1602 * fdt_setprop() sets the value of the named property in the given
1603 * node to the given value and length, creating the property if it
1604 * does not already exist.
1605 *
1606 * This function may insert or delete data from the blob, and will
1607 * therefore change the offsets of some existing nodes.
1608 *
1609 * returns:
1610 *      0, on success
1611 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1612 *              contain the new property value
1613 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1614 *      -FDT_ERR_BADLAYOUT,
1615 *      -FDT_ERR_BADMAGIC,
1616 *      -FDT_ERR_BADVERSION,
1617 *      -FDT_ERR_BADSTATE,
1618 *      -FDT_ERR_BADSTRUCTURE,
1619 *      -FDT_ERR_BADLAYOUT,
1620 *      -FDT_ERR_TRUNCATED, standard meanings
1621 */
1622int fdt_setprop(void *fdt, int nodeoffset, const char *name,
1623                const void *val, int len);
1624
1625/**
1626 * fdt_setprop_placeholder - allocate space for a property
1627 * @fdt: pointer to the device tree blob
1628 * @nodeoffset: offset of the node whose property to change
1629 * @name: name of the property to change
1630 * @len: length of the property value
1631 * @prop_data: return pointer to property data
1632 *
1633 * fdt_setprop_placeholer() allocates the named property in the given node.
1634 * If the property exists it is resized. In either case a pointer to the
1635 * property data is returned.
1636 *
1637 * This function may insert or delete data from the blob, and will
1638 * therefore change the offsets of some existing nodes.
1639 *
1640 * returns:
1641 *      0, on success
1642 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1643 *              contain the new property value
1644 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1645 *      -FDT_ERR_BADLAYOUT,
1646 *      -FDT_ERR_BADMAGIC,
1647 *      -FDT_ERR_BADVERSION,
1648 *      -FDT_ERR_BADSTATE,
1649 *      -FDT_ERR_BADSTRUCTURE,
1650 *      -FDT_ERR_BADLAYOUT,
1651 *      -FDT_ERR_TRUNCATED, standard meanings
1652 */
1653int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name,
1654                            int len, void **prop_data);
1655
1656/**
1657 * fdt_setprop_u32 - set a property to a 32-bit integer
1658 * @fdt: pointer to the device tree blob
1659 * @nodeoffset: offset of the node whose property to change
1660 * @name: name of the property to change
1661 * @val: 32-bit integer value for the property (native endian)
1662 *
1663 * fdt_setprop_u32() sets the value of the named property in the given
1664 * node to the given 32-bit integer value (converting to big-endian if
1665 * necessary), or creates a new property with that value if it does
1666 * not already exist.
1667 *
1668 * This function may insert or delete data from the blob, and will
1669 * therefore change the offsets of some existing nodes.
1670 *
1671 * returns:
1672 *      0, on success
1673 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1674 *              contain the new property value
1675 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1676 *      -FDT_ERR_BADLAYOUT,
1677 *      -FDT_ERR_BADMAGIC,
1678 *      -FDT_ERR_BADVERSION,
1679 *      -FDT_ERR_BADSTATE,
1680 *      -FDT_ERR_BADSTRUCTURE,
1681 *      -FDT_ERR_BADLAYOUT,
1682 *      -FDT_ERR_TRUNCATED, standard meanings
1683 */
1684static inline int fdt_setprop_u32(void *fdt, int nodeoffset, const char *name,
1685                                  uint32_t val)
1686{
1687        fdt32_t tmp = cpu_to_fdt32(val);
1688        return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1689}
1690
1691/**
1692 * fdt_setprop_u64 - set a property to a 64-bit integer
1693 * @fdt: pointer to the device tree blob
1694 * @nodeoffset: offset of the node whose property to change
1695 * @name: name of the property to change
1696 * @val: 64-bit integer value for the property (native endian)
1697 *
1698 * fdt_setprop_u64() sets the value of the named property in the given
1699 * node to the given 64-bit integer value (converting to big-endian if
1700 * necessary), or creates a new property with that value if it does
1701 * not already exist.
1702 *
1703 * This function may insert or delete data from the blob, and will
1704 * therefore change the offsets of some existing nodes.
1705 *
1706 * returns:
1707 *      0, on success
1708 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1709 *              contain the new property value
1710 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1711 *      -FDT_ERR_BADLAYOUT,
1712 *      -FDT_ERR_BADMAGIC,
1713 *      -FDT_ERR_BADVERSION,
1714 *      -FDT_ERR_BADSTATE,
1715 *      -FDT_ERR_BADSTRUCTURE,
1716 *      -FDT_ERR_BADLAYOUT,
1717 *      -FDT_ERR_TRUNCATED, standard meanings
1718 */
1719static inline int fdt_setprop_u64(void *fdt, int nodeoffset, const char *name,
1720                                  uint64_t val)
1721{
1722        fdt64_t tmp = cpu_to_fdt64(val);
1723        return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1724}
1725
1726/**
1727 * fdt_setprop_cell - set a property to a single cell value
1728 * @fdt: pointer to the device tree blob
1729 * @nodeoffset: offset of the node whose property to change
1730 * @name: name of the property to change
1731 * @val: 32-bit integer value for the property (native endian)
1732 *
1733 * This is an alternative name for fdt_setprop_u32()
1734 *
1735 * Return: 0 on success, negative libfdt error value otherwise.
1736 */
1737static inline int fdt_setprop_cell(void *fdt, int nodeoffset, const char *name,
1738                                   uint32_t val)
1739{
1740        return fdt_setprop_u32(fdt, nodeoffset, name, val);
1741}
1742
1743/**
1744 * fdt_setprop_string - set a property to a string value
1745 * @fdt: pointer to the device tree blob
1746 * @nodeoffset: offset of the node whose property to change
1747 * @name: name of the property to change
1748 * @str: string value for the property
1749 *
1750 * fdt_setprop_string() sets the value of the named property in the
1751 * given node to the given string value (using the length of the
1752 * string to determine the new length of the property), or creates a
1753 * new property with that value if it does not already exist.
1754 *
1755 * This function may insert or delete data from the blob, and will
1756 * therefore change the offsets of some existing nodes.
1757 *
1758 * returns:
1759 *      0, on success
1760 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1761 *              contain the new property value
1762 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1763 *      -FDT_ERR_BADLAYOUT,
1764 *      -FDT_ERR_BADMAGIC,
1765 *      -FDT_ERR_BADVERSION,
1766 *      -FDT_ERR_BADSTATE,
1767 *      -FDT_ERR_BADSTRUCTURE,
1768 *      -FDT_ERR_BADLAYOUT,
1769 *      -FDT_ERR_TRUNCATED, standard meanings
1770 */
1771#define fdt_setprop_string(fdt, nodeoffset, name, str) \
1772        fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1773
1774
1775/**
1776 * fdt_setprop_empty - set a property to an empty value
1777 * @fdt: pointer to the device tree blob
1778 * @nodeoffset: offset of the node whose property to change
1779 * @name: name of the property to change
1780 *
1781 * fdt_setprop_empty() sets the value of the named property in the
1782 * given node to an empty (zero length) value, or creates a new empty
1783 * property if it does not already exist.
1784 *
1785 * This function may insert or delete data from the blob, and will
1786 * therefore change the offsets of some existing nodes.
1787 *
1788 * returns:
1789 *      0, on success
1790 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1791 *              contain the new property value
1792 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1793 *      -FDT_ERR_BADLAYOUT,
1794 *      -FDT_ERR_BADMAGIC,
1795 *      -FDT_ERR_BADVERSION,
1796 *      -FDT_ERR_BADSTATE,
1797 *      -FDT_ERR_BADSTRUCTURE,
1798 *      -FDT_ERR_BADLAYOUT,
1799 *      -FDT_ERR_TRUNCATED, standard meanings
1800 */
1801#define fdt_setprop_empty(fdt, nodeoffset, name) \
1802        fdt_setprop((fdt), (nodeoffset), (name), NULL, 0)
1803
1804/**
1805 * fdt_appendprop - append to or create a property
1806 * @fdt: pointer to the device tree blob
1807 * @nodeoffset: offset of the node whose property to change
1808 * @name: name of the property to append to
1809 * @val: pointer to data to append to the property value
1810 * @len: length of the data to append to the property value
1811 *
1812 * fdt_appendprop() appends the value to the named property in the
1813 * given node, creating the property if it does not already exist.
1814 *
1815 * This function may insert data into the blob, and will therefore
1816 * change the offsets of some existing nodes.
1817 *
1818 * returns:
1819 *      0, on success
1820 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1821 *              contain the new property value
1822 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1823 *      -FDT_ERR_BADLAYOUT,
1824 *      -FDT_ERR_BADMAGIC,
1825 *      -FDT_ERR_BADVERSION,
1826 *      -FDT_ERR_BADSTATE,
1827 *      -FDT_ERR_BADSTRUCTURE,
1828 *      -FDT_ERR_BADLAYOUT,
1829 *      -FDT_ERR_TRUNCATED, standard meanings
1830 */
1831int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
1832                   const void *val, int len);
1833
1834/**
1835 * fdt_appendprop_u32 - append a 32-bit integer value to a property
1836 * @fdt: pointer to the device tree blob
1837 * @nodeoffset: offset of the node whose property to change
1838 * @name: name of the property to change
1839 * @val: 32-bit integer value to append to the property (native endian)
1840 *
1841 * fdt_appendprop_u32() appends the given 32-bit integer value
1842 * (converting to big-endian if necessary) to the value of the named
1843 * property in the given node, or creates a new property with that
1844 * value if it does not already exist.
1845 *
1846 * This function may insert data into the blob, and will therefore
1847 * change the offsets of some existing nodes.
1848 *
1849 * returns:
1850 *      0, on success
1851 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1852 *              contain the new property value
1853 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1854 *      -FDT_ERR_BADLAYOUT,
1855 *      -FDT_ERR_BADMAGIC,
1856 *      -FDT_ERR_BADVERSION,
1857 *      -FDT_ERR_BADSTATE,
1858 *      -FDT_ERR_BADSTRUCTURE,
1859 *      -FDT_ERR_BADLAYOUT,
1860 *      -FDT_ERR_TRUNCATED, standard meanings
1861 */
1862static inline int fdt_appendprop_u32(void *fdt, int nodeoffset,
1863                                     const char *name, uint32_t val)
1864{
1865        fdt32_t tmp = cpu_to_fdt32(val);
1866        return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1867}
1868
1869/**
1870 * fdt_appendprop_u64 - append a 64-bit integer value to a property
1871 * @fdt: pointer to the device tree blob
1872 * @nodeoffset: offset of the node whose property to change
1873 * @name: name of the property to change
1874 * @val: 64-bit integer value to append to the property (native endian)
1875 *
1876 * fdt_appendprop_u64() appends the given 64-bit integer value
1877 * (converting to big-endian if necessary) to the value of the named
1878 * property in the given node, or creates a new property with that
1879 * value if it does not already exist.
1880 *
1881 * This function may insert data into the blob, and will therefore
1882 * change the offsets of some existing nodes.
1883 *
1884 * returns:
1885 *      0, on success
1886 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1887 *              contain the new property value
1888 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1889 *      -FDT_ERR_BADLAYOUT,
1890 *      -FDT_ERR_BADMAGIC,
1891 *      -FDT_ERR_BADVERSION,
1892 *      -FDT_ERR_BADSTATE,
1893 *      -FDT_ERR_BADSTRUCTURE,
1894 *      -FDT_ERR_BADLAYOUT,
1895 *      -FDT_ERR_TRUNCATED, standard meanings
1896 */
1897static inline int fdt_appendprop_u64(void *fdt, int nodeoffset,
1898                                     const char *name, uint64_t val)
1899{
1900        fdt64_t tmp = cpu_to_fdt64(val);
1901        return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1902}
1903
1904/**
1905 * fdt_appendprop_cell - append a single cell value to a property
1906 * @fdt: pointer to the device tree blob
1907 * @nodeoffset: offset of the node whose property to change
1908 * @name: name of the property to change
1909 * @val: 32-bit integer value to append to the property (native endian)
1910 *
1911 * This is an alternative name for fdt_appendprop_u32()
1912 *
1913 * Return: 0 on success, negative libfdt error value otherwise.
1914 */
1915static inline int fdt_appendprop_cell(void *fdt, int nodeoffset,
1916                                      const char *name, uint32_t val)
1917{
1918        return fdt_appendprop_u32(fdt, nodeoffset, name, val);
1919}
1920
1921/**
1922 * fdt_appendprop_string - append a string to a property
1923 * @fdt: pointer to the device tree blob
1924 * @nodeoffset: offset of the node whose property to change
1925 * @name: name of the property to change
1926 * @str: string value to append to the property
1927 *
1928 * fdt_appendprop_string() appends the given string to the value of
1929 * the named property in the given node, or creates a new property
1930 * with that value if it does not already exist.
1931 *
1932 * This function may insert data into the blob, and will therefore
1933 * change the offsets of some existing nodes.
1934 *
1935 * returns:
1936 *      0, on success
1937 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1938 *              contain the new property value
1939 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1940 *      -FDT_ERR_BADLAYOUT,
1941 *      -FDT_ERR_BADMAGIC,
1942 *      -FDT_ERR_BADVERSION,
1943 *      -FDT_ERR_BADSTATE,
1944 *      -FDT_ERR_BADSTRUCTURE,
1945 *      -FDT_ERR_BADLAYOUT,
1946 *      -FDT_ERR_TRUNCATED, standard meanings
1947 */
1948#define fdt_appendprop_string(fdt, nodeoffset, name, str) \
1949        fdt_appendprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1950
1951/**
1952 * fdt_appendprop_addrrange - append a address range property
1953 * @fdt: pointer to the device tree blob
1954 * @parent: offset of the parent node
1955 * @nodeoffset: offset of the node to add a property at
1956 * @name: name of property
1957 * @addr: start address of a given range
1958 * @size: size of a given range
1959 *
1960 * fdt_appendprop_addrrange() appends an address range value (start
1961 * address and size) to the value of the named property in the given
1962 * node, or creates a new property with that value if it does not
1963 * already exist.
1964 * If "name" is not specified, a default "reg" is used.
1965 * Cell sizes are determined by parent's #address-cells and #size-cells.
1966 *
1967 * This function may insert data into the blob, and will therefore
1968 * change the offsets of some existing nodes.
1969 *
1970 * returns:
1971 *      0, on success
1972 *      -FDT_ERR_BADLAYOUT,
1973 *      -FDT_ERR_BADMAGIC,
1974 *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
1975 *              #address-cells property
1976 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1977 *      -FDT_ERR_BADSTATE,
1978 *      -FDT_ERR_BADSTRUCTURE,
1979 *      -FDT_ERR_BADVERSION,
1980 *      -FDT_ERR_BADVALUE, addr or size doesn't fit to respective cells size
1981 *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1982 *              contain a new property
1983 *      -FDT_ERR_TRUNCATED, standard meanings
1984 */
1985int fdt_appendprop_addrrange(void *fdt, int parent, int nodeoffset,
1986                             const char *name, uint64_t addr, uint64_t size);
1987
1988/**
1989 * fdt_delprop - delete a property
1990 * @fdt: pointer to the device tree blob
1991 * @nodeoffset: offset of the node whose property to nop
1992 * @name: name of the property to nop
1993 *
1994 * fdt_del_property() will delete the given property.
1995 *
1996 * This function will delete data from the blob, and will therefore
1997 * change the offsets of some existing nodes.
1998 *
1999 * returns:
2000 *      0, on success
2001 *      -FDT_ERR_NOTFOUND, node does not have the named property
2002 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
2003 *      -FDT_ERR_BADLAYOUT,
2004 *      -FDT_ERR_BADMAGIC,
2005 *      -FDT_ERR_BADVERSION,
2006 *      -FDT_ERR_BADSTATE,
2007 *      -FDT_ERR_BADSTRUCTURE,
2008 *      -FDT_ERR_TRUNCATED, standard meanings
2009 */
2010int fdt_delprop(void *fdt, int nodeoffset, const char *name);
2011
2012/**
2013 * fdt_add_subnode_namelen - creates a new node based on substring
2014 * @fdt: pointer to the device tree blob
2015 * @parentoffset: structure block offset of a node
2016 * @name: name of the subnode to create
2017 * @namelen: number of characters of name to consider
2018 *
2019 * Identical to fdt_add_subnode(), but use only the first @namelen
2020 * characters of @name as the name of the new node.  This is useful for
2021 * creating subnodes based on a portion of a larger string, such as a
2022 * full path.
2023 *
2024 * Return: structure block offset of the created subnode (>=0),
2025 *         negative libfdt error value otherwise
2026 */
2027#ifndef SWIG /* Not available in Python */
2028int fdt_add_subnode_namelen(void *fdt, int parentoffset,
2029                            const char *name, int namelen);
2030#endif
2031
2032/**
2033 * fdt_add_subnode - creates a new node
2034 * @fdt: pointer to the device tree blob
2035 * @parentoffset: structure block offset of a node
2036 * @name: name of the subnode to locate
2037 *
2038 * fdt_add_subnode() creates a new node as a subnode of the node at
2039 * structure block offset parentoffset, with the given name (which
2040 * should include the unit address, if any).
2041 *
2042 * This function will insert data into the blob, and will therefore
2043 * change the offsets of some existing nodes.
2044 *
2045 * returns:
2046 *      structure block offset of the created nodeequested subnode (>=0), on
2047 *              success
2048 *      -FDT_ERR_NOTFOUND, if the requested subnode does not exist
2049 *      -FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE
2050 *              tag
2051 *      -FDT_ERR_EXISTS, if the node at parentoffset already has a subnode of
2052 *              the given name
2053 *      -FDT_ERR_NOSPACE, if there is insufficient free space in the
2054 *              blob to contain the new node
2055 *      -FDT_ERR_NOSPACE
2056 *      -FDT_ERR_BADLAYOUT
2057 *      -FDT_ERR_BADMAGIC,
2058 *      -FDT_ERR_BADVERSION,
2059 *      -FDT_ERR_BADSTATE,
2060 *      -FDT_ERR_BADSTRUCTURE,
2061 *      -FDT_ERR_TRUNCATED, standard meanings.
2062 */
2063int fdt_add_subnode(void *fdt, int parentoffset, const char *name);
2064
2065/**
2066 * fdt_del_node - delete a node (subtree)
2067 * @fdt: pointer to the device tree blob
2068 * @nodeoffset: offset of the node to nop
2069 *
2070 * fdt_del_node() will remove the given node, including all its
2071 * subnodes if any, from the blob.
2072 *
2073 * This function will delete data from the blob, and will therefore
2074 * change the offsets of some existing nodes.
2075 *
2076 * returns:
2077 *      0, on success
2078 *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
2079 *      -FDT_ERR_BADLAYOUT,
2080 *      -FDT_ERR_BADMAGIC,
2081 *      -FDT_ERR_BADVERSION,
2082 *      -FDT_ERR_BADSTATE,
2083 *      -FDT_ERR_BADSTRUCTURE,
2084 *      -FDT_ERR_TRUNCATED, standard meanings
2085 */
2086int fdt_del_node(void *fdt, int nodeoffset);
2087
2088/**
2089 * fdt_overlay_apply - Applies a DT overlay on a base DT
2090 * @fdt: pointer to the base device tree blob
2091 * @fdto: pointer to the device tree overlay blob
2092 *
2093 * fdt_overlay_apply() will apply the given device tree overlay on the
2094 * given base device tree.
2095 *
2096 * Expect the base device tree to be modified, even if the function
2097 * returns an error.
2098 *
2099 * returns:
2100 *      0, on success
2101 *      -FDT_ERR_NOSPACE, there's not enough space in the base device tree
2102 *      -FDT_ERR_NOTFOUND, the overlay points to some inexistant nodes or
2103 *              properties in the base DT
2104 *      -FDT_ERR_BADPHANDLE,
2105 *      -FDT_ERR_BADOVERLAY,
2106 *      -FDT_ERR_NOPHANDLES,
2107 *      -FDT_ERR_INTERNAL,
2108 *      -FDT_ERR_BADLAYOUT,
2109 *      -FDT_ERR_BADMAGIC,
2110 *      -FDT_ERR_BADOFFSET,
2111 *      -FDT_ERR_BADPATH,
2112 *      -FDT_ERR_BADVERSION,
2113 *      -FDT_ERR_BADSTRUCTURE,
2114 *      -FDT_ERR_BADSTATE,
2115 *      -FDT_ERR_TRUNCATED, standard meanings
2116 */
2117int fdt_overlay_apply(void *fdt, void *fdto);
2118
2119/**********************************************************************/
2120/* Debugging / informational functions                                */
2121/**********************************************************************/
2122
2123const char *fdt_strerror(int errval);
2124
2125#ifdef __cplusplus
2126}
2127#endif
2128
2129#endif /* LIBFDT_H */
2130