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 #define FDT_ERR_MAX 13 120 121 /**********************************************************************/ 122 /* Low-level functions (you probably don't need these) */ 123 /**********************************************************************/ 124 125 const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int checklen); 126 static inline void *fdt_offset_ptr_w(void *fdt, int offset, int checklen) 127 { 128 return (void *)(uintptr_t)fdt_offset_ptr(fdt, offset, checklen); 129 } 130 131 uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset); 132 133 /**********************************************************************/ 134 /* Traversal functions */ 135 /**********************************************************************/ 136 137 int fdt_next_node(const void *fdt, int offset, int *depth); 138 139 /**********************************************************************/ 140 /* General functions */ 141 /**********************************************************************/ 142 143 #define fdt_get_header(fdt, field) \ 144 (fdt32_to_cpu(((const struct fdt_header *)(fdt))->field)) 145 #define fdt_magic(fdt) (fdt_get_header(fdt, magic)) 146 #define fdt_totalsize(fdt) (fdt_get_header(fdt, totalsize)) 147 #define fdt_off_dt_struct(fdt) (fdt_get_header(fdt, off_dt_struct)) 148 #define fdt_off_dt_strings(fdt) (fdt_get_header(fdt, off_dt_strings)) 149 #define fdt_off_mem_rsvmap(fdt) (fdt_get_header(fdt, off_mem_rsvmap)) 150 #define fdt_version(fdt) (fdt_get_header(fdt, version)) 151 #define fdt_last_comp_version(fdt) (fdt_get_header(fdt, last_comp_version)) 152 #define fdt_boot_cpuid_phys(fdt) (fdt_get_header(fdt, boot_cpuid_phys)) 153 #define fdt_size_dt_strings(fdt) (fdt_get_header(fdt, size_dt_strings)) 154 #define fdt_size_dt_struct(fdt) (fdt_get_header(fdt, size_dt_struct)) 155 156 #define __fdt_set_hdr(name) \ 157 static inline void fdt_set_##name(void *fdt, uint32_t val) \ 158 { \ 159 struct fdt_header *fdth = (struct fdt_header*)fdt; \ 160 fdth->name = cpu_to_fdt32(val); \ 161 } 162 __fdt_set_hdr(magic); 163 __fdt_set_hdr(totalsize); 164 __fdt_set_hdr(off_dt_struct); 165 __fdt_set_hdr(off_dt_strings); 166 __fdt_set_hdr(off_mem_rsvmap); 167 __fdt_set_hdr(version); 168 __fdt_set_hdr(last_comp_version); 169 __fdt_set_hdr(boot_cpuid_phys); 170 __fdt_set_hdr(size_dt_strings); 171 __fdt_set_hdr(size_dt_struct); 172 #undef __fdt_set_hdr 173 174 /** 175 * fdt_check_header - sanity check a device tree or possible device tree 176 * @fdt: pointer to data which might be a flattened device tree 177 * 178 * fdt_check_header() checks that the given buffer contains what 179 * appears to be a flattened device tree with sane information in its 180 * header. 181 * 182 * returns: 183 * 0, if the buffer appears to contain a valid device tree 184 * -FDT_ERR_BADMAGIC, 185 * -FDT_ERR_BADVERSION, 186 * -FDT_ERR_BADSTATE, standard meanings, as above 187 */ 188 int fdt_check_header(const void *fdt); 189 190 /** 191 * fdt_move - move a device tree around in memory 192 * @fdt: pointer to the device tree to move 193 * @buf: pointer to memory where the device is to be moved 194 * @bufsize: size of the memory space at buf 195 * 196 * fdt_move() relocates, if possible, the device tree blob located at 197 * fdt to the buffer at buf of size bufsize. The buffer may overlap 198 * with the existing device tree blob at fdt. Therefore, 199 * fdt_move(fdt, fdt, fdt_totalsize(fdt)) 200 * should always succeed. 201 * 202 * returns: 203 * 0, on success 204 * -FDT_ERR_NOSPACE, bufsize is insufficient to contain the device tree 205 * -FDT_ERR_BADMAGIC, 206 * -FDT_ERR_BADVERSION, 207 * -FDT_ERR_BADSTATE, standard meanings 208 */ 209 int fdt_move(const void *fdt, void *buf, int bufsize); 210 211 /**********************************************************************/ 212 /* Read-only functions */ 213 /**********************************************************************/ 214 215 /** 216 * fdt_string - retrieve a string from the strings block of a device tree 217 * @fdt: pointer to the device tree blob 218 * @stroffset: offset of the string within the strings block (native endian) 219 * 220 * fdt_string() retrieves a pointer to a single string from the 221 * strings block of the device tree blob at fdt. 222 * 223 * returns: 224 * a pointer to the string, on success 225 * NULL, if stroffset is out of bounds 226 */ 227 const char *fdt_string(const void *fdt, int stroffset); 228 229 /** 230 * fdt_num_mem_rsv - retrieve the number of memory reserve map entries 231 * @fdt: pointer to the device tree blob 232 * 233 * Returns the number of entries in the device tree blob's memory 234 * reservation map. This does not include the terminating 0,0 entry 235 * or any other (0,0) entries reserved for expansion. 236 * 237 * returns: 238 * the number of entries 239 */ 240 int fdt_num_mem_rsv(const void *fdt); 241 242 /** 243 * fdt_get_mem_rsv - retrieve one memory reserve map entry 244 * @fdt: pointer to the device tree blob 245 * @address, @size: pointers to 64-bit variables 246 * 247 * On success, *address and *size will contain the address and size of 248 * the n-th reserve map entry from the device tree blob, in 249 * native-endian format. 250 * 251 * returns: 252 * 0, on success 253 * -FDT_ERR_BADMAGIC, 254 * -FDT_ERR_BADVERSION, 255 * -FDT_ERR_BADSTATE, standard meanings 256 */ 257 int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size); 258 259 /** 260 * fdt_subnode_offset_namelen - find a subnode based on substring 261 * @fdt: pointer to the device tree blob 262 * @parentoffset: structure block offset of a node 263 * @name: name of the subnode to locate 264 * @namelen: number of characters of name to consider 265 * 266 * Identical to fdt_subnode_offset(), but only examine the first 267 * namelen characters of name for matching the subnode name. This is 268 * useful for finding subnodes based on a portion of a larger string, 269 * such as a full path. 270 */ 271 int fdt_subnode_offset_namelen(const void *fdt, int parentoffset, 272 const char *name, int namelen); 273 /** 274 * fdt_subnode_offset - find a subnode of a given node 275 * @fdt: pointer to the device tree blob 276 * @parentoffset: structure block offset of a node 277 * @name: name of the subnode to locate 278 * 279 * fdt_subnode_offset() finds a subnode of the node at structure block 280 * offset parentoffset with the given name. name may include a unit 281 * address, in which case fdt_subnode_offset() will find the subnode 282 * with that unit address, or the unit address may be omitted, in 283 * which case fdt_subnode_offset() will find an arbitrary subnode 284 * whose name excluding unit address matches the given name. 285 * 286 * returns: 287 * structure block offset of the requested subnode (>=0), on success 288 * -FDT_ERR_NOTFOUND, if the requested subnode does not exist 289 * -FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag 290 * -FDT_ERR_BADMAGIC, 291 * -FDT_ERR_BADVERSION, 292 * -FDT_ERR_BADSTATE, 293 * -FDT_ERR_BADSTRUCTURE, 294 * -FDT_ERR_TRUNCATED, standard meanings. 295 */ 296 int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name); 297 298 /** 299 * fdt_path_offset - find a tree node by its full path 300 * @fdt: pointer to the device tree blob 301 * @path: full path of the node to locate 302 * 303 * fdt_path_offset() finds a node of a given path in the device tree. 304 * Each path component may omit the unit address portion, but the 305 * results of this are undefined if any such path component is 306 * ambiguous (that is if there are multiple nodes at the relevant 307 * level matching the given component, differentiated only by unit 308 * address). 309 * 310 * returns: 311 * structure block offset of the node with the requested path (>=0), on success 312 * -FDT_ERR_BADPATH, given path does not begin with '/' or is invalid 313 * -FDT_ERR_NOTFOUND, if the requested node does not exist 314 * -FDT_ERR_BADMAGIC, 315 * -FDT_ERR_BADVERSION, 316 * -FDT_ERR_BADSTATE, 317 * -FDT_ERR_BADSTRUCTURE, 318 * -FDT_ERR_TRUNCATED, standard meanings. 319 */ 320 int fdt_path_offset(const void *fdt, const char *path); 321 322 /** 323 * fdt_get_name - retrieve the name of a given node 324 * @fdt: pointer to the device tree blob 325 * @nodeoffset: structure block offset of the starting node 326 * @lenp: pointer to an integer variable (will be overwritten) or NULL 327 * 328 * fdt_get_name() retrieves the name (including unit address) of the 329 * device tree node at structure block offset nodeoffset. If lenp is 330 * non-NULL, the length of this name is also returned, in the integer 331 * pointed to by lenp. 332 * 333 * returns: 334 * pointer to the node's name, on success 335 * If lenp is non-NULL, *lenp contains the length of that name (>=0) 336 * NULL, on error 337 * if lenp is non-NULL *lenp contains an error code (<0): 338 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag 339 * -FDT_ERR_BADMAGIC, 340 * -FDT_ERR_BADVERSION, 341 * -FDT_ERR_BADSTATE, standard meanings 342 */ 343 const char *fdt_get_name(const void *fdt, int nodeoffset, int *lenp); 344 345 /** 346 * fdt_get_property_namelen - find a property based on substring 347 * @fdt: pointer to the device tree blob 348 * @nodeoffset: offset of the node whose property to find 349 * @name: name of the property to find 350 * @namelen: number of characters of name to consider 351 * @lenp: pointer to an integer variable (will be overwritten) or NULL 352 * 353 * Identical to fdt_get_property_namelen(), but only examine the first 354 * namelen characters of name for matching the property name. 355 */ 356 const struct fdt_property *fdt_get_property_namelen(const void *fdt, 357 int nodeoffset, 358 const char *name, 359 int namelen, int *lenp); 360 361 /** 362 * fdt_get_property - find a given property in a given node 363 * @fdt: pointer to the device tree blob 364 * @nodeoffset: offset of the node whose property to find 365 * @name: name of the property to find 366 * @lenp: pointer to an integer variable (will be overwritten) or NULL 367 * 368 * fdt_get_property() retrieves a pointer to the fdt_property 369 * structure within the device tree blob corresponding to the property 370 * named 'name' of the node at offset nodeoffset. If lenp is 371 * non-NULL, the length of the property value is also returned, in the 372 * integer pointed to by lenp. 373 * 374 * returns: 375 * pointer to the structure representing the property 376 * if lenp is non-NULL, *lenp contains the length of the property 377 * value (>=0) 378 * NULL, on error 379 * if lenp is non-NULL, *lenp contains an error code (<0): 380 * -FDT_ERR_NOTFOUND, node does not have named property 381 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag 382 * -FDT_ERR_BADMAGIC, 383 * -FDT_ERR_BADVERSION, 384 * -FDT_ERR_BADSTATE, 385 * -FDT_ERR_BADSTRUCTURE, 386 * -FDT_ERR_TRUNCATED, standard meanings 387 */ 388 const struct fdt_property *fdt_get_property(const void *fdt, int nodeoffset, 389 const char *name, int *lenp); 390 static inline struct fdt_property *fdt_get_property_w(void *fdt, int nodeoffset, 391 const char *name, 392 int *lenp) 393 { 394 return (struct fdt_property *)(uintptr_t) 395 fdt_get_property(fdt, nodeoffset, name, lenp); 396 } 397 398 /** 399 * fdt_getprop_namelen - get property value based on substring 400 * @fdt: pointer to the device tree blob 401 * @nodeoffset: offset of the node whose property to find 402 * @name: name of the property to find 403 * @namelen: number of characters of name to consider 404 * @lenp: pointer to an integer variable (will be overwritten) or NULL 405 * 406 * Identical to fdt_getprop(), but only examine the first namelen 407 * characters of name for matching the property name. 408 */ 409 const void *fdt_getprop_namelen(const void *fdt, int nodeoffset, 410 const char *name, int namelen, int *lenp); 411 412 /** 413 * fdt_getprop - retrieve the value of a given property 414 * @fdt: pointer to the device tree blob 415 * @nodeoffset: offset of the node whose property to find 416 * @name: name of the property to find 417 * @lenp: pointer to an integer variable (will be overwritten) or NULL 418 * 419 * fdt_getprop() retrieves a pointer to the value of the property 420 * named 'name' of the node at offset nodeoffset (this will be a 421 * pointer to within the device blob itself, not a copy of the value). 422 * If lenp is non-NULL, the length of the property value is also 423 * returned, in the integer pointed to by lenp. 424 * 425 * returns: 426 * pointer to the property's value 427 * if lenp is non-NULL, *lenp contains the length of the property 428 * value (>=0) 429 * NULL, on error 430 * if lenp is non-NULL, *lenp contains an error code (<0): 431 * -FDT_ERR_NOTFOUND, node does not have named property 432 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag 433 * -FDT_ERR_BADMAGIC, 434 * -FDT_ERR_BADVERSION, 435 * -FDT_ERR_BADSTATE, 436 * -FDT_ERR_BADSTRUCTURE, 437 * -FDT_ERR_TRUNCATED, standard meanings 438 */ 439 const void *fdt_getprop(const void *fdt, int nodeoffset, 440 const char *name, int *lenp); 441 static inline void *fdt_getprop_w(void *fdt, int nodeoffset, 442 const char *name, int *lenp) 443 { 444 return (void *)(uintptr_t)fdt_getprop(fdt, nodeoffset, name, lenp); 445 } 446 447 /** 448 * fdt_get_phandle - retrieve the phandle of a given node 449 * @fdt: pointer to the device tree blob 450 * @nodeoffset: structure block offset of the node 451 * 452 * fdt_get_phandle() retrieves the phandle of the device tree node at 453 * structure block offset nodeoffset. 454 * 455 * returns: 456 * the phandle of the node at nodeoffset, on success (!= 0, != -1) 457 * 0, if the node has no phandle, or another error occurs 458 */ 459 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset); 460 461 /** 462 * fdt_get_alias_namelen - get alias based on substring 463 * @fdt: pointer to the device tree blob 464 * @name: name of the alias th look up 465 * @namelen: number of characters of name to consider 466 * 467 * Identical to fdt_get_alias(), but only examine the first namelen 468 * characters of name for matching the alias name. 469 */ 470 const char *fdt_get_alias_namelen(const void *fdt, 471 const char *name, int namelen); 472 473 /** 474 * fdt_get_alias - retreive the path referenced by a given alias 475 * @fdt: pointer to the device tree blob 476 * @name: name of the alias th look up 477 * 478 * fdt_get_alias() retrieves the value of a given alias. That is, the 479 * value of the property named 'name' in the node /aliases. 480 * 481 * returns: 482 * a pointer to the expansion of the alias named 'name', of it exists 483 * NULL, if the given alias or the /aliases node does not exist 484 */ 485 const char *fdt_get_alias(const void *fdt, const char *name); 486 487 /** 488 * fdt_get_path - determine the full path of a node 489 * @fdt: pointer to the device tree blob 490 * @nodeoffset: offset of the node whose path to find 491 * @buf: character buffer to contain the returned path (will be overwritten) 492 * @buflen: size of the character buffer at buf 493 * 494 * fdt_get_path() computes the full path of the node at offset 495 * nodeoffset, and records that path in the buffer at buf. 496 * 497 * NOTE: This function is expensive, as it must scan the device tree 498 * structure from the start to nodeoffset. 499 * 500 * returns: 501 * 0, on success 502 * buf contains the absolute path of the node at 503 * nodeoffset, as a NUL-terminated string. 504 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag 505 * -FDT_ERR_NOSPACE, the path of the given node is longer than (bufsize-1) 506 * characters and will not fit in the given buffer. 507 * -FDT_ERR_BADMAGIC, 508 * -FDT_ERR_BADVERSION, 509 * -FDT_ERR_BADSTATE, 510 * -FDT_ERR_BADSTRUCTURE, standard meanings 511 */ 512 int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen); 513 514 /** 515 * fdt_supernode_atdepth_offset - find a specific ancestor of a node 516 * @fdt: pointer to the device tree blob 517 * @nodeoffset: offset of the node whose parent to find 518 * @supernodedepth: depth of the ancestor to find 519 * @nodedepth: pointer to an integer variable (will be overwritten) or NULL 520 * 521 * fdt_supernode_atdepth_offset() finds an ancestor of the given node 522 * at a specific depth from the root (where the root itself has depth 523 * 0, its immediate subnodes depth 1 and so forth). So 524 * fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, NULL); 525 * will always return 0, the offset of the root node. If the node at 526 * nodeoffset has depth D, then: 527 * fdt_supernode_atdepth_offset(fdt, nodeoffset, D, NULL); 528 * will return nodeoffset itself. 529 * 530 * NOTE: This function is expensive, as it must scan the device tree 531 * structure from the start to nodeoffset. 532 * 533 * returns: 534 535 * structure block offset of the node at node offset's ancestor 536 * of depth supernodedepth (>=0), on success 537 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag 538 * -FDT_ERR_NOTFOUND, supernodedepth was greater than the depth of nodeoffset 539 * -FDT_ERR_BADMAGIC, 540 * -FDT_ERR_BADVERSION, 541 * -FDT_ERR_BADSTATE, 542 * -FDT_ERR_BADSTRUCTURE, standard meanings 543 */ 544 int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset, 545 int supernodedepth, int *nodedepth); 546 547 /** 548 * fdt_node_depth - find the depth of a given node 549 * @fdt: pointer to the device tree blob 550 * @nodeoffset: offset of the node whose parent to find 551 * 552 * fdt_node_depth() finds the depth of a given node. The root node 553 * has depth 0, its immediate subnodes depth 1 and so forth. 554 * 555 * NOTE: This function is expensive, as it must scan the device tree 556 * structure from the start to nodeoffset. 557 * 558 * returns: 559 * depth of the node at nodeoffset (>=0), on success 560 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag 561 * -FDT_ERR_BADMAGIC, 562 * -FDT_ERR_BADVERSION, 563 * -FDT_ERR_BADSTATE, 564 * -FDT_ERR_BADSTRUCTURE, standard meanings 565 */ 566 int fdt_node_depth(const void *fdt, int nodeoffset); 567 568 /** 569 * fdt_parent_offset - find the parent of a given node 570 * @fdt: pointer to the device tree blob 571 * @nodeoffset: offset of the node whose parent to find 572 * 573 * fdt_parent_offset() locates the parent node of a given node (that 574 * is, it finds the offset of the node which contains the node at 575 * nodeoffset as a subnode). 576 * 577 * NOTE: This function is expensive, as it must scan the device tree 578 * structure from the start to nodeoffset, *twice*. 579 * 580 * returns: 581 * structure block offset of the parent of the node at nodeoffset 582 * (>=0), on success 583 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag 584 * -FDT_ERR_BADMAGIC, 585 * -FDT_ERR_BADVERSION, 586 * -FDT_ERR_BADSTATE, 587 * -FDT_ERR_BADSTRUCTURE, standard meanings 588 */ 589 int fdt_parent_offset(const void *fdt, int nodeoffset); 590 591 /** 592 * fdt_node_offset_by_prop_value - find nodes with a given property value 593 * @fdt: pointer to the device tree blob 594 * @startoffset: only find nodes after this offset 595 * @propname: property name to check 596 * @propval: property value to search for 597 * @proplen: length of the value in propval 598 * 599 * fdt_node_offset_by_prop_value() returns the offset of the first 600 * node after startoffset, which has a property named propname whose 601 * value is of length proplen and has value equal to propval; or if 602 * startoffset is -1, the very first such node in the tree. 603 * 604 * To iterate through all nodes matching the criterion, the following 605 * idiom can be used: 606 * offset = fdt_node_offset_by_prop_value(fdt, -1, propname, 607 * propval, proplen); 608 * while (offset != -FDT_ERR_NOTFOUND) { 609 * // other code here 610 * offset = fdt_node_offset_by_prop_value(fdt, offset, propname, 611 * propval, proplen); 612 * } 613 * 614 * Note the -1 in the first call to the function, if 0 is used here 615 * instead, the function will never locate the root node, even if it 616 * matches the criterion. 617 * 618 * returns: 619 * structure block offset of the located node (>= 0, >startoffset), 620 * on success 621 * -FDT_ERR_NOTFOUND, no node matching the criterion exists in the 622 * tree after startoffset 623 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag 624 * -FDT_ERR_BADMAGIC, 625 * -FDT_ERR_BADVERSION, 626 * -FDT_ERR_BADSTATE, 627 * -FDT_ERR_BADSTRUCTURE, standard meanings 628 */ 629 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset, 630 const char *propname, 631 const void *propval, int proplen); 632 633 /** 634 * fdt_node_offset_by_phandle - find the node with a given phandle 635 * @fdt: pointer to the device tree blob 636 * @phandle: phandle value 637 * 638 * fdt_node_offset_by_phandle() returns the offset of the node 639 * which has the given phandle value. If there is more than one node 640 * in the tree with the given phandle (an invalid tree), results are 641 * undefined. 642 * 643 * returns: 644 * structure block offset of the located node (>= 0), on success 645 * -FDT_ERR_NOTFOUND, no node with that phandle exists 646 * -FDT_ERR_BADPHANDLE, given phandle value was invalid (0 or -1) 647 * -FDT_ERR_BADMAGIC, 648 * -FDT_ERR_BADVERSION, 649 * -FDT_ERR_BADSTATE, 650 * -FDT_ERR_BADSTRUCTURE, standard meanings 651 */ 652 int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle); 653 654 /** 655 * fdt_node_check_compatible: check a node's compatible property 656 * @fdt: pointer to the device tree blob 657 * @nodeoffset: offset of a tree node 658 * @compatible: string to match against 659 * 660 * 661 * fdt_node_check_compatible() returns 0 if the given node contains a 662 * 'compatible' property with the given string as one of its elements, 663 * it returns non-zero otherwise, or on error. 664 * 665 * returns: 666 * 0, if the node has a 'compatible' property listing the given string 667 * 1, if the node has a 'compatible' property, but it does not list 668 * the given string 669 * -FDT_ERR_NOTFOUND, if the given node has no 'compatible' property 670 * -FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag 671 * -FDT_ERR_BADMAGIC, 672 * -FDT_ERR_BADVERSION, 673 * -FDT_ERR_BADSTATE, 674 * -FDT_ERR_BADSTRUCTURE, standard meanings 675 */ 676 int fdt_node_check_compatible(const void *fdt, int nodeoffset, 677 const char *compatible); 678 679 /** 680 * fdt_node_offset_by_compatible - find nodes with a given 'compatible' value 681 * @fdt: pointer to the device tree blob 682 * @startoffset: only find nodes after this offset 683 * @compatible: 'compatible' string to match against 684 * 685 * fdt_node_offset_by_compatible() returns the offset of the first 686 * node after startoffset, which has a 'compatible' property which 687 * lists the given compatible string; or if startoffset is -1, the 688 * very first such node in the tree. 689 * 690 * To iterate through all nodes matching the criterion, the following 691 * idiom can be used: 692 * offset = fdt_node_offset_by_compatible(fdt, -1, compatible); 693 * while (offset != -FDT_ERR_NOTFOUND) { 694 * // other code here 695 * offset = fdt_node_offset_by_compatible(fdt, offset, compatible); 696 * } 697 * 698 * Note the -1 in the first call to the function, if 0 is used here 699 * instead, the function will never locate the root node, even if it 700 * matches the criterion. 701 * 702 * returns: 703 * structure block offset of the located node (>= 0, >startoffset), 704 * on success 705 * -FDT_ERR_NOTFOUND, no node matching the criterion exists in the 706 * tree after startoffset 707 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag 708 * -FDT_ERR_BADMAGIC, 709 * -FDT_ERR_BADVERSION, 710 * -FDT_ERR_BADSTATE, 711 * -FDT_ERR_BADSTRUCTURE, standard meanings 712 */ 713 int fdt_node_offset_by_compatible(const void *fdt, int startoffset, 714 const char *compatible); 715 716 /**********************************************************************/ 717 /* Write-in-place functions */ 718 /**********************************************************************/ 719 720 /** 721 * fdt_setprop_inplace - change a property's value, but not its size 722 * @fdt: pointer to the device tree blob 723 * @nodeoffset: offset of the node whose property to change 724 * @name: name of the property to change 725 * @val: pointer to data to replace the property value with 726 * @len: length of the property value 727 * 728 * fdt_setprop_inplace() replaces the value of a given property with 729 * the data in val, of length len. This function cannot change the 730 * size of a property, and so will only work if len is equal to the 731 * current length of the property. 732 * 733 * This function will alter only the bytes in the blob which contain 734 * the given property value, and will not alter or move any other part 735 * of the tree. 736 * 737 * returns: 738 * 0, on success 739 * -FDT_ERR_NOSPACE, if len is not equal to the property's current length 740 * -FDT_ERR_NOTFOUND, node does not have the named property 741 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag 742 * -FDT_ERR_BADMAGIC, 743 * -FDT_ERR_BADVERSION, 744 * -FDT_ERR_BADSTATE, 745 * -FDT_ERR_BADSTRUCTURE, 746 * -FDT_ERR_TRUNCATED, standard meanings 747 */ 748 int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name, 749 const void *val, int len); 750 751 /** 752 * fdt_setprop_inplace_cell - change the value of a single-cell property 753 * @fdt: pointer to the device tree blob 754 * @nodeoffset: offset of the node whose property to change 755 * @name: name of the property to change 756 * @val: cell (32-bit integer) value to replace the property with 757 * 758 * fdt_setprop_inplace_cell() replaces the value of a given property 759 * with the 32-bit integer cell value in val, converting val to 760 * big-endian if necessary. This function cannot change the size of a 761 * property, and so will only work if the property already exists and 762 * has length 4. 763 * 764 * This function will alter only the bytes in the blob which contain 765 * the given property value, and will not alter or move any other part 766 * of the tree. 767 * 768 * returns: 769 * 0, on success 770 * -FDT_ERR_NOSPACE, if the property's length is not equal to 4 771 * -FDT_ERR_NOTFOUND, node does not have the named property 772 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag 773 * -FDT_ERR_BADMAGIC, 774 * -FDT_ERR_BADVERSION, 775 * -FDT_ERR_BADSTATE, 776 * -FDT_ERR_BADSTRUCTURE, 777 * -FDT_ERR_TRUNCATED, standard meanings 778 */ 779 static inline int fdt_setprop_inplace_cell(void *fdt, int nodeoffset, 780 const char *name, uint32_t val) 781 { 782 val = cpu_to_fdt32(val); 783 return fdt_setprop_inplace(fdt, nodeoffset, name, &val, sizeof(val)); 784 } 785 786 /** 787 * fdt_nop_property - replace a property with nop tags 788 * @fdt: pointer to the device tree blob 789 * @nodeoffset: offset of the node whose property to nop 790 * @name: name of the property to nop 791 * 792 * fdt_nop_property() will replace a given property's representation 793 * in the blob with FDT_NOP tags, effectively removing it from the 794 * tree. 795 * 796 * This function will alter only the bytes in the blob which contain 797 * the property, and will not alter or move any other part of the 798 * tree. 799 * 800 * returns: 801 * 0, on success 802 * -FDT_ERR_NOTFOUND, node does not have the named property 803 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag 804 * -FDT_ERR_BADMAGIC, 805 * -FDT_ERR_BADVERSION, 806 * -FDT_ERR_BADSTATE, 807 * -FDT_ERR_BADSTRUCTURE, 808 * -FDT_ERR_TRUNCATED, standard meanings 809 */ 810 int fdt_nop_property(void *fdt, int nodeoffset, const char *name); 811 812 /** 813 * fdt_nop_node - replace a node (subtree) with nop tags 814 * @fdt: pointer to the device tree blob 815 * @nodeoffset: offset of the node to nop 816 * 817 * fdt_nop_node() will replace a given node's representation in the 818 * blob, including all its subnodes, if any, with FDT_NOP tags, 819 * effectively removing it from the tree. 820 * 821 * This function will alter only the bytes in the blob which contain 822 * the node and its properties and subnodes, and will not alter or 823 * move any other part of the tree. 824 * 825 * returns: 826 * 0, on success 827 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag 828 * -FDT_ERR_BADMAGIC, 829 * -FDT_ERR_BADVERSION, 830 * -FDT_ERR_BADSTATE, 831 * -FDT_ERR_BADSTRUCTURE, 832 * -FDT_ERR_TRUNCATED, standard meanings 833 */ 834 int fdt_nop_node(void *fdt, int nodeoffset); 835 836 /**********************************************************************/ 837 /* Sequential write functions */ 838 /**********************************************************************/ 839 840 int fdt_create(void *buf, int bufsize); 841 int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size); 842 int fdt_finish_reservemap(void *fdt); 843 int fdt_begin_node(void *fdt, const char *name); 844 int fdt_property(void *fdt, const char *name, const void *val, int len); 845 static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val) 846 { 847 val = cpu_to_fdt32(val); 848 return fdt_property(fdt, name, &val, sizeof(val)); 849 } 850 #define fdt_property_string(fdt, name, str) \ 851 fdt_property(fdt, name, str, strlen(str)+1) 852 int fdt_end_node(void *fdt); 853 int fdt_finish(void *fdt); 854 855 /**********************************************************************/ 856 /* Read-write functions */ 857 /**********************************************************************/ 858 859 int fdt_open_into(const void *fdt, void *buf, int bufsize); 860 int fdt_pack(void *fdt); 861 862 /** 863 * fdt_add_mem_rsv - add one memory reserve map entry 864 * @fdt: pointer to the device tree blob 865 * @address, @size: 64-bit values (native endian) 866 * 867 * Adds a reserve map entry to the given blob reserving a region at 868 * address address of length size. 869 * 870 * This function will insert data into the reserve map and will 871 * therefore change the indexes of some entries in the table. 872 * 873 * returns: 874 * 0, on success 875 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to 876 * contain the new reservation entry 877 * -FDT_ERR_BADMAGIC, 878 * -FDT_ERR_BADVERSION, 879 * -FDT_ERR_BADSTATE, 880 * -FDT_ERR_BADSTRUCTURE, 881 * -FDT_ERR_BADLAYOUT, 882 * -FDT_ERR_TRUNCATED, standard meanings 883 */ 884 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size); 885 886 /** 887 * fdt_del_mem_rsv - remove a memory reserve map entry 888 * @fdt: pointer to the device tree blob 889 * @n: entry to remove 890 * 891 * fdt_del_mem_rsv() removes the n-th memory reserve map entry from 892 * the blob. 893 * 894 * This function will delete data from the reservation table and will 895 * therefore change the indexes of some entries in the table. 896 * 897 * returns: 898 * 0, on success 899 * -FDT_ERR_NOTFOUND, there is no entry of the given index (i.e. there 900 * are less than n+1 reserve map entries) 901 * -FDT_ERR_BADMAGIC, 902 * -FDT_ERR_BADVERSION, 903 * -FDT_ERR_BADSTATE, 904 * -FDT_ERR_BADSTRUCTURE, 905 * -FDT_ERR_BADLAYOUT, 906 * -FDT_ERR_TRUNCATED, standard meanings 907 */ 908 int fdt_del_mem_rsv(void *fdt, int n); 909 910 /** 911 * fdt_set_name - change the name of a given node 912 * @fdt: pointer to the device tree blob 913 * @nodeoffset: structure block offset of a node 914 * @name: name to give the node 915 * 916 * fdt_set_name() replaces the name (including unit address, if any) 917 * of the given node with the given string. NOTE: this function can't 918 * efficiently check if the new name is unique amongst the given 919 * node's siblings; results are undefined if this function is invoked 920 * with a name equal to one of the given node's siblings. 921 * 922 * This function may insert or delete data from the blob, and will 923 * therefore change the offsets of some existing nodes. 924 * 925 * returns: 926 * 0, on success 927 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob 928 * to contain the new name 929 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag 930 * -FDT_ERR_BADMAGIC, 931 * -FDT_ERR_BADVERSION, 932 * -FDT_ERR_BADSTATE, standard meanings 933 */ 934 int fdt_set_name(void *fdt, int nodeoffset, const char *name); 935 936 /** 937 * fdt_setprop - create or change a property 938 * @fdt: pointer to the device tree blob 939 * @nodeoffset: offset of the node whose property to change 940 * @name: name of the property to change 941 * @val: pointer to data to set the property value to 942 * @len: length of the property value 943 * 944 * fdt_setprop() sets the value of the named property in the given 945 * node to the given value and length, creating the property if it 946 * does not already exist. 947 * 948 * This function may insert or delete data from the blob, and will 949 * therefore change the offsets of some existing nodes. 950 * 951 * returns: 952 * 0, on success 953 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to 954 * contain the new property value 955 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag 956 * -FDT_ERR_BADLAYOUT, 957 * -FDT_ERR_BADMAGIC, 958 * -FDT_ERR_BADVERSION, 959 * -FDT_ERR_BADSTATE, 960 * -FDT_ERR_BADSTRUCTURE, 961 * -FDT_ERR_BADLAYOUT, 962 * -FDT_ERR_TRUNCATED, standard meanings 963 */ 964 int fdt_setprop(void *fdt, int nodeoffset, const char *name, 965 const void *val, int len); 966 967 /** 968 * fdt_setprop_cell - set a property to a single cell value 969 * @fdt: pointer to the device tree blob 970 * @nodeoffset: offset of the node whose property to change 971 * @name: name of the property to change 972 * @val: 32-bit integer value for the property (native endian) 973 * 974 * fdt_setprop_cell() sets the value of the named property in the 975 * given node to the given cell value (converting to big-endian if 976 * necessary), or creates a new property with that value if it does 977 * not already exist. 978 * 979 * This function may insert or delete data from the blob, and will 980 * therefore change the offsets of some existing nodes. 981 * 982 * returns: 983 * 0, on success 984 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to 985 * contain the new property value 986 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag 987 * -FDT_ERR_BADLAYOUT, 988 * -FDT_ERR_BADMAGIC, 989 * -FDT_ERR_BADVERSION, 990 * -FDT_ERR_BADSTATE, 991 * -FDT_ERR_BADSTRUCTURE, 992 * -FDT_ERR_BADLAYOUT, 993 * -FDT_ERR_TRUNCATED, standard meanings 994 */ 995 static inline int fdt_setprop_cell(void *fdt, int nodeoffset, const char *name, 996 uint32_t val) 997 { 998 val = cpu_to_fdt32(val); 999 return fdt_setprop(fdt, nodeoffset, name, &val, sizeof(val)); 1000 } 1001 1002 /** 1003 * fdt_setprop_string - set a property to a string value 1004 * @fdt: pointer to the device tree blob 1005 * @nodeoffset: offset of the node whose property to change 1006 * @name: name of the property to change 1007 * @str: string value for the property 1008 * 1009 * fdt_setprop_string() sets the value of the named property in the 1010 * given node to the given string value (using the length of the 1011 * string to determine the new length of the property), or creates a 1012 * new property with that value if it does not already exist. 1013 * 1014 * This function may insert or delete data from the blob, and will 1015 * therefore change the offsets of some existing nodes. 1016 * 1017 * returns: 1018 * 0, on success 1019 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to 1020 * contain the new property value 1021 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag 1022 * -FDT_ERR_BADLAYOUT, 1023 * -FDT_ERR_BADMAGIC, 1024 * -FDT_ERR_BADVERSION, 1025 * -FDT_ERR_BADSTATE, 1026 * -FDT_ERR_BADSTRUCTURE, 1027 * -FDT_ERR_BADLAYOUT, 1028 * -FDT_ERR_TRUNCATED, standard meanings 1029 */ 1030 #define fdt_setprop_string(fdt, nodeoffset, name, str) \ 1031 fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1) 1032 1033 /** 1034 * fdt_delprop - delete a property 1035 * @fdt: pointer to the device tree blob 1036 * @nodeoffset: offset of the node whose property to nop 1037 * @name: name of the property to nop 1038 * 1039 * fdt_del_property() will delete the given property. 1040 * 1041 * This function will delete data from the blob, and will therefore 1042 * change the offsets of some existing nodes. 1043 * 1044 * returns: 1045 * 0, on success 1046 * -FDT_ERR_NOTFOUND, node does not have the named property 1047 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag 1048 * -FDT_ERR_BADLAYOUT, 1049 * -FDT_ERR_BADMAGIC, 1050 * -FDT_ERR_BADVERSION, 1051 * -FDT_ERR_BADSTATE, 1052 * -FDT_ERR_BADSTRUCTURE, 1053 * -FDT_ERR_TRUNCATED, standard meanings 1054 */ 1055 int fdt_delprop(void *fdt, int nodeoffset, const char *name); 1056 1057 /** 1058 * fdt_add_subnode_namelen - creates a new node based on substring 1059 * @fdt: pointer to the device tree blob 1060 * @parentoffset: structure block offset of a node 1061 * @name: name of the subnode to locate 1062 * @namelen: number of characters of name to consider 1063 * 1064 * Identical to fdt_add_subnode(), but use only the first namelen 1065 * characters of name as the name of the new node. This is useful for 1066 * creating subnodes based on a portion of a larger string, such as a 1067 * full path. 1068 */ 1069 int fdt_add_subnode_namelen(void *fdt, int parentoffset, 1070 const char *name, int namelen); 1071 1072 /** 1073 * fdt_add_subnode - creates a new node 1074 * @fdt: pointer to the device tree blob 1075 * @parentoffset: structure block offset of a node 1076 * @name: name of the subnode to locate 1077 * 1078 * fdt_add_subnode() creates a new node as a subnode of the node at 1079 * structure block offset parentoffset, with the given name (which 1080 * should include the unit address, if any). 1081 * 1082 * This function will insert data into the blob, and will therefore 1083 * change the offsets of some existing nodes. 1084 1085 * returns: 1086 * structure block offset of the created nodeequested subnode (>=0), on success 1087 * -FDT_ERR_NOTFOUND, if the requested subnode does not exist 1088 * -FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag 1089 * -FDT_ERR_EXISTS, if the node at parentoffset already has a subnode of 1090 * the given name 1091 * -FDT_ERR_NOSPACE, if there is insufficient free space in the 1092 * blob to contain the new node 1093 * -FDT_ERR_NOSPACE 1094 * -FDT_ERR_BADLAYOUT 1095 * -FDT_ERR_BADMAGIC, 1096 * -FDT_ERR_BADVERSION, 1097 * -FDT_ERR_BADSTATE, 1098 * -FDT_ERR_BADSTRUCTURE, 1099 * -FDT_ERR_TRUNCATED, standard meanings. 1100 */ 1101 int fdt_add_subnode(void *fdt, int parentoffset, const char *name); 1102 1103 /** 1104 * fdt_del_node - delete a node (subtree) 1105 * @fdt: pointer to the device tree blob 1106 * @nodeoffset: offset of the node to nop 1107 * 1108 * fdt_del_node() will remove the given node, including all its 1109 * subnodes if any, from the blob. 1110 * 1111 * This function will delete data from the blob, and will therefore 1112 * change the offsets of some existing nodes. 1113 * 1114 * returns: 1115 * 0, on success 1116 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag 1117 * -FDT_ERR_BADLAYOUT, 1118 * -FDT_ERR_BADMAGIC, 1119 * -FDT_ERR_BADVERSION, 1120 * -FDT_ERR_BADSTATE, 1121 * -FDT_ERR_BADSTRUCTURE, 1122 * -FDT_ERR_TRUNCATED, standard meanings 1123 */ 1124 int fdt_del_node(void *fdt, int nodeoffset); 1125 1126 /**********************************************************************/ 1127 /* Debugging / informational functions */ 1128 /**********************************************************************/ 1129 1130 const char *fdt_strerror(int errval); 1131 1132 #endif /* _LIBFDT_H */ 1133