headers/libs/libfdt/libfdt.h

   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_first_property_offset - find the offset of a node's first property
 347  * @fdt: pointer to the device tree blob
 348  * @nodeoffset: structure block offset of a node
 349  *
 350  * fdt_first_property_offset() finds the first property of the node at
 351  * the given structure block offset.
 352  *
 353  * returns:
 354  *      structure block offset of the property (>=0), on success
 355  *      -FDT_ERR_NOTFOUND, if the requested node has no properties
 356  *      -FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_BEGIN_NODE tag
 357  *      -FDT_ERR_BADMAGIC,
 358  *      -FDT_ERR_BADVERSION,
 359  *      -FDT_ERR_BADSTATE,
 360  *      -FDT_ERR_BADSTRUCTURE,
 361  *      -FDT_ERR_TRUNCATED, standard meanings.
 362  */
 363 int fdt_first_property_offset(const void *fdt, int nodeoffset);
 364
 365 /**
 366  * fdt_next_property_offset - step through a node's properties
 367  * @fdt: pointer to the device tree blob
 368  * @offset: structure block offset of a property
 369  *
 370  * fdt_next_property_offset() finds the property immediately after the
 371  * one at the given structure block offset.  This will be a property
 372  * of the same node as the given property.
 373  *
 374  * returns:
 375  *      structure block offset of the next property (>=0), on success
 376  *      -FDT_ERR_NOTFOUND, if the given property is the last in its node
 377  *      -FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_PROP tag
 378  *      -FDT_ERR_BADMAGIC,
 379  *      -FDT_ERR_BADVERSION,
 380  *      -FDT_ERR_BADSTATE,
 381  *      -FDT_ERR_BADSTRUCTURE,
 382  *      -FDT_ERR_TRUNCATED, standard meanings.
 383  */
 384 int fdt_next_property_offset(const void *fdt, int offset);
 385
 386 /**
 387  * fdt_get_property_by_offset - retrieve the property at a given offset
 388  * @fdt: pointer to the device tree blob
 389  * @offset: offset of the property to retrieve
 390  * @lenp: pointer to an integer variable (will be overwritten) or NULL
 391  *
 392  * fdt_get_property_by_offset() retrieves a pointer to the
 393  * fdt_property structure within the device tree blob at the given
 394  * offset.  If lenp is non-NULL, the length of the property value is
 395  * also returned, in the integer pointed to by lenp.
 396  *
 397  * returns:
 398  *      pointer to the structure representing the property
 399  *              if lenp is non-NULL, *lenp contains the length of the property
 400  *              value (>=0)
 401  *      NULL, on error
 402  *              if lenp is non-NULL, *lenp contains an error code (<0):
 403  *              -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
 404  *              -FDT_ERR_BADMAGIC,
 405  *              -FDT_ERR_BADVERSION,
 406  *              -FDT_ERR_BADSTATE,
 407  *              -FDT_ERR_BADSTRUCTURE,
 408  *              -FDT_ERR_TRUNCATED, standard meanings
 409  */
 410 const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
 411                                                       int offset,
 412                                                       int *lenp);
 413
 414 /**
 415  * fdt_get_property_namelen - find a property based on substring
 416  * @fdt: pointer to the device tree blob
 417  * @nodeoffset: offset of the node whose property to find
 418  * @name: name of the property to find
 419  * @namelen: number of characters of name to consider
 420  * @lenp: pointer to an integer variable (will be overwritten) or NULL
 421  *
 422  * Identical to fdt_get_property_namelen(), but only examine the first
 423  * namelen characters of name for matching the property name.
 424  */
 425 const struct fdt_property *fdt_get_property_namelen(const void *fdt,
 426                                                     int nodeoffset,
 427                                                     const char *name,
 428                                                     int namelen, int *lenp);
 429
 430 /**
 431  * fdt_get_property - find a given property in a given node
 432  * @fdt: pointer to the device tree blob
 433  * @nodeoffset: offset of the node whose property to find
 434  * @name: name of the property to find
 435  * @lenp: pointer to an integer variable (will be overwritten) or NULL
 436  *
 437  * fdt_get_property() retrieves a pointer to the fdt_property
 438  * structure within the device tree blob corresponding to the property
 439  * named 'name' of the node at offset nodeoffset.  If lenp is
 440  * non-NULL, the length of the property value is also returned, in the
 441  * integer pointed to by lenp.
 442  *
 443  * returns:
 444  *      pointer to the structure representing the property
 445  *              if lenp is non-NULL, *lenp contains the length of the property
 446  *              value (>=0)
 447  *      NULL, on error
 448  *              if lenp is non-NULL, *lenp contains an error code (<0):
 449  *              -FDT_ERR_NOTFOUND, node does not have named property
 450  *              -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
 451  *              -FDT_ERR_BADMAGIC,
 452  *              -FDT_ERR_BADVERSION,
 453  *              -FDT_ERR_BADSTATE,
 454  *              -FDT_ERR_BADSTRUCTURE,
 455  *              -FDT_ERR_TRUNCATED, standard meanings
 456  */
 457 const struct fdt_property *fdt_get_property(const void *fdt, int nodeoffset,
 458                                             const char *name, int *lenp);
 459 static inline struct fdt_property *fdt_get_property_w(void *fdt, int nodeoffset,
 460                                                       const char *name,
 461                                                       int *lenp)
 462 {
 463         return (struct fdt_property *)(uintptr_t)
 464                 fdt_get_property(fdt, nodeoffset, name, lenp);
 465 }
 466
 467 /**
 468  * fdt_getprop_by_offset - retrieve the value of a property at a given offset
 469  * @fdt: pointer to the device tree blob
 470  * @ffset: offset of the property to read
 471  * @namep: pointer to a string variable (will be overwritten) or NULL
 472  * @lenp: pointer to an integer variable (will be overwritten) or NULL
 473  *
 474  * fdt_getprop_by_offset() retrieves a pointer to the value of the
 475  * property at structure block offset 'offset' (this will be a pointer
 476  * to within the device blob itself, not a copy of the value).  If
 477  * lenp is non-NULL, the length of the property value is also
 478  * returned, in the integer pointed to by lenp.  If namep is non-NULL,
 479  * the property's namne will also be returned in the char * pointed to
 480  * by namep (this will be a pointer to within the device tree's string
 481  * block, not a new copy of the name).
 482  *
 483  * returns:
 484  *      pointer to the property's value
 485  *              if lenp is non-NULL, *lenp contains the length of the property
 486  *              value (>=0)
 487  *              if namep is non-NULL *namep contiains a pointer to the property
 488  *              name.
 489  *      NULL, on error
 490  *              if lenp is non-NULL, *lenp contains an error code (<0):
 491  *              -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
 492  *              -FDT_ERR_BADMAGIC,
 493  *              -FDT_ERR_BADVERSION,
 494  *              -FDT_ERR_BADSTATE,
 495  *              -FDT_ERR_BADSTRUCTURE,
 496  *              -FDT_ERR_TRUNCATED, standard meanings
 497  */
 498 const void *fdt_getprop_by_offset(const void *fdt, int offset,
 499                                   const char **namep, int *lenp);
 500
 501 /**
 502  * fdt_getprop_namelen - get property value based on substring
 503  * @fdt: pointer to the device tree blob
 504  * @nodeoffset: offset of the node whose property to find
 505  * @name: name of the property to find
 506  * @namelen: number of characters of name to consider
 507  * @lenp: pointer to an integer variable (will be overwritten) or NULL
 508  *
 509  * Identical to fdt_getprop(), but only examine the first namelen
 510  * characters of name for matching the property name.
 511  */
 512 const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
 513                                 const char *name, int namelen, int *lenp);
 514
 515 /**
 516  * fdt_getprop - retrieve the value of a given property
 517  * @fdt: pointer to the device tree blob
 518  * @nodeoffset: offset of the node whose property to find
 519  * @name: name of the property to find
 520  * @lenp: pointer to an integer variable (will be overwritten) or NULL
 521  *
 522  * fdt_getprop() retrieves a pointer to the value of the property
 523  * named 'name' of the node at offset nodeoffset (this will be a
 524  * pointer to within the device blob itself, not a copy of the value).
 525  * If lenp is non-NULL, the length of the property value is also
 526  * returned, in the integer pointed to by lenp.
 527  *
 528  * returns:
 529  *      pointer to the property's value
 530  *              if lenp is non-NULL, *lenp contains the length of the property
 531  *              value (>=0)
 532  *      NULL, on error
 533  *              if lenp is non-NULL, *lenp contains an error code (<0):
 534  *              -FDT_ERR_NOTFOUND, node does not have named property
 535  *              -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
 536  *              -FDT_ERR_BADMAGIC,
 537  *              -FDT_ERR_BADVERSION,
 538  *              -FDT_ERR_BADSTATE,
 539  *              -FDT_ERR_BADSTRUCTURE,
 540  *              -FDT_ERR_TRUNCATED, standard meanings
 541  */
 542 const void *fdt_getprop(const void *fdt, int nodeoffset,
 543                         const char *name, int *lenp);
 544 static inline void *fdt_getprop_w(void *fdt, int nodeoffset,
 545                                   const char *name, int *lenp)
 546 {
 547         return (void *)(uintptr_t)fdt_getprop(fdt, nodeoffset, name, lenp);
 548 }
 549
 550 /**
 551  * fdt_get_phandle - retrieve the phandle of a given node
 552  * @fdt: pointer to the device tree blob
 553  * @nodeoffset: structure block offset of the node
 554  *
 555  * fdt_get_phandle() retrieves the phandle of the device tree node at
 556  * structure block offset nodeoffset.
 557  *
 558  * returns:
 559  *      the phandle of the node at nodeoffset, on success (!= 0, != -1)
 560  *      0, if the node has no phandle, or another error occurs
 561  */
 562 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset);
 563
 564 /**
 565  * fdt_get_alias_namelen - get alias based on substring
 566  * @fdt: pointer to the device tree blob
 567  * @name: name of the alias th look up
 568  * @namelen: number of characters of name to consider
 569  *
 570  * Identical to fdt_get_alias(), but only examine the first namelen
 571  * characters of name for matching the alias name.
 572  */
 573 const char *fdt_get_alias_namelen(const void *fdt,
 574                                   const char *name, int namelen);
 575
 576 /**
 577  * fdt_get_alias - retreive the path referenced by a given alias
 578  * @fdt: pointer to the device tree blob
 579  * @name: name of the alias th look up
 580  *
 581  * fdt_get_alias() retrieves the value of a given alias.  That is, the
 582  * value of the property named 'name' in the node /aliases.
 583  *
 584  * returns:
 585  *      a pointer to the expansion of the alias named 'name', of it exists
 586  *      NULL, if the given alias or the /aliases node does not exist
 587  */
 588 const char *fdt_get_alias(const void *fdt, const char *name);
 589
 590 /**
 591  * fdt_get_path - determine the full path of a node
 592  * @fdt: pointer to the device tree blob
 593  * @nodeoffset: offset of the node whose path to find
 594  * @buf: character buffer to contain the returned path (will be overwritten)
 595  * @buflen: size of the character buffer at buf
 596  *
 597  * fdt_get_path() computes the full path of the node at offset
 598  * nodeoffset, and records that path in the buffer at buf.
 599  *
 600  * NOTE: This function is expensive, as it must scan the device tree
 601  * structure from the start to nodeoffset.
 602  *
 603  * returns:
 604  *      0, on success
 605  *              buf contains the absolute path of the node at
 606  *              nodeoffset, as a NUL-terminated string.
 607  *      -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 608  *      -FDT_ERR_NOSPACE, the path of the given node is longer than (bufsize-1)
 609  *              characters and will not fit in the given buffer.
 610  *      -FDT_ERR_BADMAGIC,
 611  *      -FDT_ERR_BADVERSION,
 612  *      -FDT_ERR_BADSTATE,
 613  *      -FDT_ERR_BADSTRUCTURE, standard meanings
 614  */
 615 int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen);
 616
 617 /**
 618  * fdt_supernode_atdepth_offset - find a specific ancestor of a node
 619  * @fdt: pointer to the device tree blob
 620  * @nodeoffset: offset of the node whose parent to find
 621  * @supernodedepth: depth of the ancestor to find
 622  * @nodedepth: pointer to an integer variable (will be overwritten) or NULL
 623  *
 624  * fdt_supernode_atdepth_offset() finds an ancestor of the given node
 625  * at a specific depth from the root (where the root itself has depth
 626  * 0, its immediate subnodes depth 1 and so forth).  So
 627  *      fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, NULL);
 628  * will always return 0, the offset of the root node.  If the node at
 629  * nodeoffset has depth D, then:
 630  *      fdt_supernode_atdepth_offset(fdt, nodeoffset, D, NULL);
 631  * will return nodeoffset itself.
 632  *
 633  * NOTE: This function is expensive, as it must scan the device tree
 634  * structure from the start to nodeoffset.
 635  *
 636  * returns:
 637
 638  *      structure block offset of the node at node offset's ancestor
 639  *              of depth supernodedepth (>=0), on success
 640  *      -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 641 *       -FDT_ERR_NOTFOUND, supernodedepth was greater than the depth of nodeoffset
 642  *      -FDT_ERR_BADMAGIC,
 643  *      -FDT_ERR_BADVERSION,
 644  *      -FDT_ERR_BADSTATE,
 645  *      -FDT_ERR_BADSTRUCTURE, standard meanings
 646  */
 647 int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
 648                                  int supernodedepth, int *nodedepth);
 649
 650 /**
 651  * fdt_node_depth - find the depth of a given node
 652  * @fdt: pointer to the device tree blob
 653  * @nodeoffset: offset of the node whose parent to find
 654  *
 655  * fdt_node_depth() finds the depth of a given node.  The root node
 656  * has depth 0, its immediate subnodes depth 1 and so forth.
 657  *
 658  * NOTE: This function is expensive, as it must scan the device tree
 659  * structure from the start to nodeoffset.
 660  *
 661  * returns:
 662  *      depth of the node at nodeoffset (>=0), on success
 663  *      -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 664  *      -FDT_ERR_BADMAGIC,
 665  *      -FDT_ERR_BADVERSION,
 666  *      -FDT_ERR_BADSTATE,
 667  *      -FDT_ERR_BADSTRUCTURE, standard meanings
 668  */
 669 int fdt_node_depth(const void *fdt, int nodeoffset);
 670
 671 /**
 672  * fdt_parent_offset - find the parent of a given node
 673  * @fdt: pointer to the device tree blob
 674  * @nodeoffset: offset of the node whose parent to find
 675  *
 676  * fdt_parent_offset() locates the parent node of a given node (that
 677  * is, it finds the offset of the node which contains the node at
 678  * nodeoffset as a subnode).
 679  *
 680  * NOTE: This function is expensive, as it must scan the device tree
 681  * structure from the start to nodeoffset, *twice*.
 682  *
 683  * returns:
 684  *      structure block offset of the parent of the node at nodeoffset
 685  *              (>=0), on success
 686  *      -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 687  *      -FDT_ERR_BADMAGIC,
 688  *      -FDT_ERR_BADVERSION,
 689  *      -FDT_ERR_BADSTATE,
 690  *      -FDT_ERR_BADSTRUCTURE, standard meanings
 691  */
 692 int fdt_parent_offset(const void *fdt, int nodeoffset);
 693
 694 /**
 695  * fdt_node_offset_by_prop_value - find nodes with a given property value
 696  * @fdt: pointer to the device tree blob
 697  * @startoffset: only find nodes after this offset
 698  * @propname: property name to check
 699  * @propval: property value to search for
 700  * @proplen: length of the value in propval
 701  *
 702  * fdt_node_offset_by_prop_value() returns the offset of the first
 703  * node after startoffset, which has a property named propname whose
 704  * value is of length proplen and has value equal to propval; or if
 705  * startoffset is -1, the very first such node in the tree.
 706  *
 707  * To iterate through all nodes matching the criterion, the following
 708  * idiom can be used:
 709  *      offset = fdt_node_offset_by_prop_value(fdt, -1, propname,
 710  *                                             propval, proplen);
 711  *      while (offset != -FDT_ERR_NOTFOUND) {
 712  *              // other code here
 713  *              offset = fdt_node_offset_by_prop_value(fdt, offset, propname,
 714  *                                                     propval, proplen);
 715  *      }
 716  *
 717  * Note the -1 in the first call to the function, if 0 is used here
 718  * instead, the function will never locate the root node, even if it
 719  * matches the criterion.
 720  *
 721  * returns:
 722  *      structure block offset of the located node (>= 0, >startoffset),
 723  *               on success
 724  *      -FDT_ERR_NOTFOUND, no node matching the criterion exists in the
 725  *              tree after startoffset
 726  *      -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 727  *      -FDT_ERR_BADMAGIC,
 728  *      -FDT_ERR_BADVERSION,
 729  *      -FDT_ERR_BADSTATE,
 730  *      -FDT_ERR_BADSTRUCTURE, standard meanings
 731  */
 732 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
 733                                   const char *propname,
 734                                   const void *propval, int proplen);
 735
 736 /**
 737  * fdt_node_offset_by_phandle - find the node with a given phandle
 738  * @fdt: pointer to the device tree blob
 739  * @phandle: phandle value
 740  *
 741  * fdt_node_offset_by_phandle() returns the offset of the node
 742  * which has the given phandle value.  If there is more than one node
 743  * in the tree with the given phandle (an invalid tree), results are
 744  * undefined.
 745  *
 746  * returns:
 747  *      structure block offset of the located node (>= 0), on success
 748  *      -FDT_ERR_NOTFOUND, no node with that phandle exists
 749  *      -FDT_ERR_BADPHANDLE, given phandle value was invalid (0 or -1)
 750  *      -FDT_ERR_BADMAGIC,
 751  *      -FDT_ERR_BADVERSION,
 752  *      -FDT_ERR_BADSTATE,
 753  *      -FDT_ERR_BADSTRUCTURE, standard meanings
 754  */
 755 int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle);
 756
 757 /**
 758  * fdt_node_check_compatible: check a node's compatible property
 759  * @fdt: pointer to the device tree blob
 760  * @nodeoffset: offset of a tree node
 761  * @compatible: string to match against
 762  *
 763  *
 764  * fdt_node_check_compatible() returns 0 if the given node contains a
 765  * 'compatible' property with the given string as one of its elements,
 766  * it returns non-zero otherwise, or on error.
 767  *
 768  * returns:
 769  *      0, if the node has a 'compatible' property listing the given string
 770  *      1, if the node has a 'compatible' property, but it does not list
 771  *              the given string
 772  *      -FDT_ERR_NOTFOUND, if the given node has no 'compatible' property
 773  *      -FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag
 774  *      -FDT_ERR_BADMAGIC,
 775  *      -FDT_ERR_BADVERSION,
 776  *      -FDT_ERR_BADSTATE,
 777  *      -FDT_ERR_BADSTRUCTURE, standard meanings
 778  */
 779 int fdt_node_check_compatible(const void *fdt, int nodeoffset,
 780                               const char *compatible);
 781
 782 /**
 783  * fdt_node_offset_by_compatible - find nodes with a given 'compatible' value
 784  * @fdt: pointer to the device tree blob
 785  * @startoffset: only find nodes after this offset
 786  * @compatible: 'compatible' string to match against
 787  *
 788  * fdt_node_offset_by_compatible() returns the offset of the first
 789  * node after startoffset, which has a 'compatible' property which
 790  * lists the given compatible string; or if startoffset is -1, the
 791  * very first such node in the tree.
 792  *
 793  * To iterate through all nodes matching the criterion, the following
 794  * idiom can be used:
 795  *      offset = fdt_node_offset_by_compatible(fdt, -1, compatible);
 796  *      while (offset != -FDT_ERR_NOTFOUND) {
 797  *              // other code here
 798  *              offset = fdt_node_offset_by_compatible(fdt, offset, compatible);
 799  *      }
 800  *
 801  * Note the -1 in the first call to the function, if 0 is used here
 802  * instead, the function will never locate the root node, even if it
 803  * matches the criterion.
 804  *
 805  * returns:
 806  *      structure block offset of the located node (>= 0, >startoffset),
 807  *               on success
 808  *      -FDT_ERR_NOTFOUND, no node matching the criterion exists in the
 809  *              tree after startoffset
 810  *      -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 811  *      -FDT_ERR_BADMAGIC,
 812  *      -FDT_ERR_BADVERSION,
 813  *      -FDT_ERR_BADSTATE,
 814  *      -FDT_ERR_BADSTRUCTURE, standard meanings
 815  */
 816 int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
 817                                   const char *compatible);
 818
 819 /**********************************************************************/
 820 /* Write-in-place functions                                           */
 821 /**********************************************************************/
 822
 823 /**
 824  * fdt_setprop_inplace - change a property's value, but not its size
 825  * @fdt: pointer to the device tree blob
 826  * @nodeoffset: offset of the node whose property to change
 827  * @name: name of the property to change
 828  * @val: pointer to data to replace the property value with
 829  * @len: length of the property value
 830  *
 831  * fdt_setprop_inplace() replaces the value of a given property with
 832  * the data in val, of length len.  This function cannot change the
 833  * size of a property, and so will only work if len is equal to the
 834  * current length of the property.
 835  *
 836  * This function will alter only the bytes in the blob which contain
 837  * the given property value, and will not alter or move any other part
 838  * of the tree.
 839  *
 840  * returns:
 841  *      0, on success
 842  *      -FDT_ERR_NOSPACE, if len is not equal to the property's current length
 843  *      -FDT_ERR_NOTFOUND, node does not have the named property
 844  *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
 845  *      -FDT_ERR_BADMAGIC,
 846  *      -FDT_ERR_BADVERSION,
 847  *      -FDT_ERR_BADSTATE,
 848  *      -FDT_ERR_BADSTRUCTURE,
 849  *      -FDT_ERR_TRUNCATED, standard meanings
 850  */
 851 int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
 852                         const void *val, int len);
 853
 854 /**
 855  * fdt_setprop_inplace_cell - change the value of a single-cell property
 856  * @fdt: pointer to the device tree blob
 857  * @nodeoffset: offset of the node whose property to change
 858  * @name: name of the property to change
 859  * @val: cell (32-bit integer) value to replace the property with
 860  *
 861  * fdt_setprop_inplace_cell() replaces the value of a given property
 862  * with the 32-bit integer cell value in val, converting val to
 863  * big-endian if necessary.  This function cannot change the size of a
 864  * property, and so will only work if the property already exists and
 865  * has length 4.
 866  *
 867  * This function will alter only the bytes in the blob which contain
 868  * the given property value, and will not alter or move any other part
 869  * of the tree.
 870  *
 871  * returns:
 872  *      0, on success
 873  *      -FDT_ERR_NOSPACE, if the property's length is not equal to 4
 874   *     -FDT_ERR_NOTFOUND, node does not have the named property
 875  *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
 876  *      -FDT_ERR_BADMAGIC,
 877  *      -FDT_ERR_BADVERSION,
 878  *      -FDT_ERR_BADSTATE,
 879  *      -FDT_ERR_BADSTRUCTURE,
 880  *      -FDT_ERR_TRUNCATED, standard meanings
 881  */
 882 static inline int fdt_setprop_inplace_cell(void *fdt, int nodeoffset,
 883                                            const char *name, uint32_t val)
 884 {
 885         val = cpu_to_fdt32(val);
 886         return fdt_setprop_inplace(fdt, nodeoffset, name, &val, sizeof(val));
 887 }
 888
 889 /**
 890  * fdt_nop_property - replace a property with nop tags
 891  * @fdt: pointer to the device tree blob
 892  * @nodeoffset: offset of the node whose property to nop
 893  * @name: name of the property to nop
 894  *
 895  * fdt_nop_property() will replace a given property's representation
 896  * in the blob with FDT_NOP tags, effectively removing it from the
 897  * tree.
 898  *
 899  * This function will alter only the bytes in the blob which contain
 900  * the property, and will not alter or move any other part of the
 901  * tree.
 902  *
 903  * returns:
 904  *      0, on success
 905  *      -FDT_ERR_NOTFOUND, node does not have the named property
 906  *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
 907  *      -FDT_ERR_BADMAGIC,
 908  *      -FDT_ERR_BADVERSION,
 909  *      -FDT_ERR_BADSTATE,
 910  *      -FDT_ERR_BADSTRUCTURE,
 911  *      -FDT_ERR_TRUNCATED, standard meanings
 912  */
 913 int fdt_nop_property(void *fdt, int nodeoffset, const char *name);
 914
 915 /**
 916  * fdt_nop_node - replace a node (subtree) with nop tags
 917  * @fdt: pointer to the device tree blob
 918  * @nodeoffset: offset of the node to nop
 919  *
 920  * fdt_nop_node() will replace a given node's representation in the
 921  * blob, including all its subnodes, if any, with FDT_NOP tags,
 922  * effectively removing it from the tree.
 923  *
 924  * This function will alter only the bytes in the blob which contain
 925  * the node and its properties and subnodes, and will not alter or
 926  * move any other part of the tree.
 927  *
 928  * returns:
 929  *      0, on success
 930  *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
 931  *      -FDT_ERR_BADMAGIC,
 932  *      -FDT_ERR_BADVERSION,
 933  *      -FDT_ERR_BADSTATE,
 934  *      -FDT_ERR_BADSTRUCTURE,
 935  *      -FDT_ERR_TRUNCATED, standard meanings
 936  */
 937 int fdt_nop_node(void *fdt, int nodeoffset);
 938
 939 /**********************************************************************/
 940 /* Sequential write functions                                         */
 941 /**********************************************************************/
 942
 943 int fdt_create(void *buf, int bufsize);
 944 int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size);
 945 int fdt_finish_reservemap(void *fdt);
 946 int fdt_begin_node(void *fdt, const char *name);
 947 int fdt_property(void *fdt, const char *name, const void *val, int len);
 948 static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val)
 949 {
 950         val = cpu_to_fdt32(val);
 951         return fdt_property(fdt, name, &val, sizeof(val));
 952 }
 953 #define fdt_property_string(fdt, name, str) \
 954         fdt_property(fdt, name, str, strlen(str)+1)
 955 int fdt_end_node(void *fdt);
 956 int fdt_finish(void *fdt);
 957
 958 /**********************************************************************/
 959 /* Read-write functions                                               */
 960 /**********************************************************************/
 961
 962 int fdt_open_into(const void *fdt, void *buf, int bufsize);
 963 int fdt_pack(void *fdt);
 964
 965 /**
 966  * fdt_add_mem_rsv - add one memory reserve map entry
 967  * @fdt: pointer to the device tree blob
 968  * @address, @size: 64-bit values (native endian)
 969  *
 970  * Adds a reserve map entry to the given blob reserving a region at
 971  * address address of length size.
 972  *
 973  * This function will insert data into the reserve map and will
 974  * therefore change the indexes of some entries in the table.
 975  *
 976  * returns:
 977  *      0, on success
 978  *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
 979  *              contain the new reservation entry
 980  *      -FDT_ERR_BADMAGIC,
 981  *      -FDT_ERR_BADVERSION,
 982  *      -FDT_ERR_BADSTATE,
 983  *      -FDT_ERR_BADSTRUCTURE,
 984  *      -FDT_ERR_BADLAYOUT,
 985  *      -FDT_ERR_TRUNCATED, standard meanings
 986  */
 987 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size);
 988
 989 /**
 990  * fdt_del_mem_rsv - remove a memory reserve map entry
 991  * @fdt: pointer to the device tree blob
 992  * @n: entry to remove
 993  *
 994  * fdt_del_mem_rsv() removes the n-th memory reserve map entry from
 995  * the blob.
 996  *
 997  * This function will delete data from the reservation table and will
 998  * therefore change the indexes of some entries in the table.
 999  *
1000  * returns:
1001  *      0, on success
1002  *      -FDT_ERR_NOTFOUND, there is no entry of the given index (i.e. there
1003  *              are less than n+1 reserve map entries)
1004  *      -FDT_ERR_BADMAGIC,
1005  *      -FDT_ERR_BADVERSION,
1006  *      -FDT_ERR_BADSTATE,
1007  *      -FDT_ERR_BADSTRUCTURE,
1008  *      -FDT_ERR_BADLAYOUT,
1009  *      -FDT_ERR_TRUNCATED, standard meanings
1010  */
1011 int fdt_del_mem_rsv(void *fdt, int n);
1012
1013 /**
1014  * fdt_set_name - change the name of a given node
1015  * @fdt: pointer to the device tree blob
1016  * @nodeoffset: structure block offset of a node
1017  * @name: name to give the node
1018  *
1019  * fdt_set_name() replaces the name (including unit address, if any)
1020  * of the given node with the given string.  NOTE: this function can't
1021  * efficiently check if the new name is unique amongst the given
1022  * node's siblings; results are undefined if this function is invoked
1023  * with a name equal to one of the given node's siblings.
1024  *
1025  * This function may insert or delete data from the blob, and will
1026  * therefore change the offsets of some existing nodes.
1027  *
1028  * returns:
1029  *      0, on success
1030  *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob
1031  *              to contain the new name
1032  *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1033  *      -FDT_ERR_BADMAGIC,
1034  *      -FDT_ERR_BADVERSION,
1035  *      -FDT_ERR_BADSTATE, standard meanings
1036  */
1037 int fdt_set_name(void *fdt, int nodeoffset, const char *name);
1038
1039 /**
1040  * fdt_setprop - create or change a property
1041  * @fdt: pointer to the device tree blob
1042  * @nodeoffset: offset of the node whose property to change
1043  * @name: name of the property to change
1044  * @val: pointer to data to set the property value to
1045  * @len: length of the property value
1046  *
1047  * fdt_setprop() sets the value of the named property in the given
1048  * node to the given value and length, creating the property if it
1049  * does not already exist.
1050  *
1051  * This function may insert or delete data from the blob, and will
1052  * therefore change the offsets of some existing nodes.
1053  *
1054  * returns:
1055  *      0, on success
1056  *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1057  *              contain the new property value
1058  *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1059  *      -FDT_ERR_BADLAYOUT,
1060  *      -FDT_ERR_BADMAGIC,
1061  *      -FDT_ERR_BADVERSION,
1062  *      -FDT_ERR_BADSTATE,
1063  *      -FDT_ERR_BADSTRUCTURE,
1064  *      -FDT_ERR_BADLAYOUT,
1065  *      -FDT_ERR_TRUNCATED, standard meanings
1066  */
1067 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
1068                 const void *val, int len);
1069
1070 /**
1071  * fdt_setprop_cell - set a property to a single cell value
1072  * @fdt: pointer to the device tree blob
1073  * @nodeoffset: offset of the node whose property to change
1074  * @name: name of the property to change
1075  * @val: 32-bit integer value for the property (native endian)
1076  *
1077  * fdt_setprop_cell() sets the value of the named property in the
1078  * given node to the given cell value (converting to big-endian if
1079  * necessary), or creates a new property with that value if it does
1080  * not already exist.
1081  *
1082  * This function may insert or delete data from the blob, and will
1083  * therefore change the offsets of some existing nodes.
1084  *
1085  * returns:
1086  *      0, on success
1087  *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1088  *              contain the new property value
1089  *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1090  *      -FDT_ERR_BADLAYOUT,
1091  *      -FDT_ERR_BADMAGIC,
1092  *      -FDT_ERR_BADVERSION,
1093  *      -FDT_ERR_BADSTATE,
1094  *      -FDT_ERR_BADSTRUCTURE,
1095  *      -FDT_ERR_BADLAYOUT,
1096  *      -FDT_ERR_TRUNCATED, standard meanings
1097  */
1098 static inline int fdt_setprop_cell(void *fdt, int nodeoffset, const char *name,
1099                                    uint32_t val)
1100 {
1101         val = cpu_to_fdt32(val);
1102         return fdt_setprop(fdt, nodeoffset, name, &val, sizeof(val));
1103 }
1104
1105 /**
1106  * fdt_setprop_string - set a property to a string value
1107  * @fdt: pointer to the device tree blob
1108  * @nodeoffset: offset of the node whose property to change
1109  * @name: name of the property to change
1110  * @str: string value for the property
1111  *
1112  * fdt_setprop_string() sets the value of the named property in the
1113  * given node to the given string value (using the length of the
1114  * string to determine the new length of the property), or creates a
1115  * new property with that value if it does not already exist.
1116  *
1117  * This function may insert or delete data from the blob, and will
1118  * therefore change the offsets of some existing nodes.
1119  *
1120  * returns:
1121  *      0, on success
1122  *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1123  *              contain the new property value
1124  *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1125  *      -FDT_ERR_BADLAYOUT,
1126  *      -FDT_ERR_BADMAGIC,
1127  *      -FDT_ERR_BADVERSION,
1128  *      -FDT_ERR_BADSTATE,
1129  *      -FDT_ERR_BADSTRUCTURE,
1130  *      -FDT_ERR_BADLAYOUT,
1131  *      -FDT_ERR_TRUNCATED, standard meanings
1132  */
1133 #define fdt_setprop_string(fdt, nodeoffset, name, str) \
1134         fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1135
1136 /**
1137  * fdt_delprop - delete a property
1138  * @fdt: pointer to the device tree blob
1139  * @nodeoffset: offset of the node whose property to nop
1140  * @name: name of the property to nop
1141  *
1142  * fdt_del_property() will delete the given property.
1143  *
1144  * This function will delete data from the blob, and will therefore
1145  * change the offsets of some existing nodes.
1146  *
1147  * returns:
1148  *      0, on success
1149  *      -FDT_ERR_NOTFOUND, node does not have the named property
1150  *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1151  *      -FDT_ERR_BADLAYOUT,
1152  *      -FDT_ERR_BADMAGIC,
1153  *      -FDT_ERR_BADVERSION,
1154  *      -FDT_ERR_BADSTATE,
1155  *      -FDT_ERR_BADSTRUCTURE,
1156  *      -FDT_ERR_TRUNCATED, standard meanings
1157  */
1158 int fdt_delprop(void *fdt, int nodeoffset, const char *name);
1159
1160 /**
1161  * fdt_add_subnode_namelen - creates a new node based on substring
1162  * @fdt: pointer to the device tree blob
1163  * @parentoffset: structure block offset of a node
1164  * @name: name of the subnode to locate
1165  * @namelen: number of characters of name to consider
1166  *
1167  * Identical to fdt_add_subnode(), but use only the first namelen
1168  * characters of name as the name of the new node.  This is useful for
1169  * creating subnodes based on a portion of a larger string, such as a
1170  * full path.
1171  */
1172 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
1173                             const char *name, int namelen);
1174
1175 /**
1176  * fdt_add_subnode - creates a new node
1177  * @fdt: pointer to the device tree blob
1178  * @parentoffset: structure block offset of a node
1179  * @name: name of the subnode to locate
1180  *
1181  * fdt_add_subnode() creates a new node as a subnode of the node at
1182  * structure block offset parentoffset, with the given name (which
1183  * should include the unit address, if any).
1184  *
1185  * This function will insert data into the blob, and will therefore
1186  * change the offsets of some existing nodes.
1187
1188  * returns:
1189  *      structure block offset of the created nodeequested subnode (>=0), on success
1190  *      -FDT_ERR_NOTFOUND, if the requested subnode does not exist
1191  *      -FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag
1192  *      -FDT_ERR_EXISTS, if the node at parentoffset already has a subnode of
1193  *              the given name
1194  *      -FDT_ERR_NOSPACE, if there is insufficient free space in the
1195  *              blob to contain the new node
1196  *      -FDT_ERR_NOSPACE
1197  *      -FDT_ERR_BADLAYOUT
1198  *      -FDT_ERR_BADMAGIC,
1199  *      -FDT_ERR_BADVERSION,
1200  *      -FDT_ERR_BADSTATE,
1201  *      -FDT_ERR_BADSTRUCTURE,
1202  *      -FDT_ERR_TRUNCATED, standard meanings.
1203  */
1204 int fdt_add_subnode(void *fdt, int parentoffset, const char *name);
1205
1206 /**
1207  * fdt_del_node - delete a node (subtree)
1208  * @fdt: pointer to the device tree blob
1209  * @nodeoffset: offset of the node to nop
1210  *
1211  * fdt_del_node() will remove the given node, including all its
1212  * subnodes if any, from the blob.
1213  *
1214  * This function will delete data from the blob, and will therefore
1215  * change the offsets of some existing nodes.
1216  *
1217  * returns:
1218  *      0, on success
1219  *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1220  *      -FDT_ERR_BADLAYOUT,
1221  *      -FDT_ERR_BADMAGIC,
1222  *      -FDT_ERR_BADVERSION,
1223  *      -FDT_ERR_BADSTATE,
1224  *      -FDT_ERR_BADSTRUCTURE,
1225  *      -FDT_ERR_TRUNCATED, standard meanings
1226  */
1227 int fdt_del_node(void *fdt, int nodeoffset);
1228
1229 /**********************************************************************/
1230 /* Debugging / informational functions                                */
1231 /**********************************************************************/
1232
1233 const char *fdt_strerror(int errval);
1234
1235 #endif /* _LIBFDT_H */