xref: /openbmc/linux/scripts/dtc/libfdt/libfdt.h (revision 9cfc5c90)
1 #ifndef _LIBFDT_H
2 #define _LIBFDT_H
3 /*
4  * libfdt - Flat Device Tree manipulation
5  * Copyright (C) 2006 David Gibson, IBM Corporation.
6  *
7  * libfdt is dual licensed: you can use it either under the terms of
8  * the GPL, or the BSD license, at your option.
9  *
10  *  a) This library is free software; you can redistribute it and/or
11  *     modify it under the terms of the GNU General Public License as
12  *     published by the Free Software Foundation; either version 2 of the
13  *     License, or (at your option) any later version.
14  *
15  *     This library is distributed in the hope that it will be useful,
16  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
17  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  *     GNU General Public License for more details.
19  *
20  *     You should have received a copy of the GNU General Public
21  *     License along with this library; if not, write to the Free
22  *     Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
23  *     MA 02110-1301 USA
24  *
25  * Alternatively,
26  *
27  *  b) Redistribution and use in source and binary forms, with or
28  *     without modification, are permitted provided that the following
29  *     conditions are met:
30  *
31  *     1. Redistributions of source code must retain the above
32  *        copyright notice, this list of conditions and the following
33  *        disclaimer.
34  *     2. Redistributions in binary form must reproduce the above
35  *        copyright notice, this list of conditions and the following
36  *        disclaimer in the documentation and/or other materials
37  *        provided with the distribution.
38  *
39  *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
40  *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
41  *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
42  *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
43  *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
44  *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45  *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46  *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47  *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48  *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
49  *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
50  *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
51  *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
52  */
53 
54 #include "libfdt_env.h"
55 #include "fdt.h"
56 
57 #define FDT_FIRST_SUPPORTED_VERSION	0x10
58 #define FDT_LAST_SUPPORTED_VERSION	0x11
59 
60 /* Error codes: informative error codes */
61 #define FDT_ERR_NOTFOUND	1
62 	/* FDT_ERR_NOTFOUND: The requested node or property does not exist */
63 #define FDT_ERR_EXISTS		2
64 	/* FDT_ERR_EXISTS: Attemped to create a node or property which
65 	 * already exists */
66 #define FDT_ERR_NOSPACE		3
67 	/* FDT_ERR_NOSPACE: Operation needed to expand the device
68 	 * tree, but its buffer did not have sufficient space to
69 	 * contain the expanded tree. Use fdt_open_into() to move the
70 	 * device tree to a buffer with more space. */
71 
72 /* Error codes: codes for bad parameters */
73 #define FDT_ERR_BADOFFSET	4
74 	/* FDT_ERR_BADOFFSET: Function was passed a structure block
75 	 * offset which is out-of-bounds, or which points to an
76 	 * unsuitable part of the structure for the operation. */
77 #define FDT_ERR_BADPATH		5
78 	/* FDT_ERR_BADPATH: Function was passed a badly formatted path
79 	 * (e.g. missing a leading / for a function which requires an
80 	 * absolute path) */
81 #define FDT_ERR_BADPHANDLE	6
82 	/* FDT_ERR_BADPHANDLE: Function was passed an invalid phandle
83 	 * value.  phandle values of 0 and -1 are not permitted. */
84 #define FDT_ERR_BADSTATE	7
85 	/* FDT_ERR_BADSTATE: Function was passed an incomplete device
86 	 * tree created by the sequential-write functions, which is
87 	 * not sufficiently complete for the requested operation. */
88 
89 /* Error codes: codes for bad device tree blobs */
90 #define FDT_ERR_TRUNCATED	8
91 	/* FDT_ERR_TRUNCATED: Structure block of the given device tree
92 	 * ends without an FDT_END tag. */
93 #define FDT_ERR_BADMAGIC	9
94 	/* FDT_ERR_BADMAGIC: Given "device tree" appears not to be a
95 	 * device tree at all - it is missing the flattened device
96 	 * tree magic number. */
97 #define FDT_ERR_BADVERSION	10
98 	/* FDT_ERR_BADVERSION: Given device tree has a version which
99 	 * can't be handled by the requested operation.  For
100 	 * read-write functions, this may mean that fdt_open_into() is
101 	 * required to convert the tree to the expected version. */
102 #define FDT_ERR_BADSTRUCTURE	11
103 	/* FDT_ERR_BADSTRUCTURE: Given device tree has a corrupt
104 	 * structure block or other serious error (e.g. misnested
105 	 * nodes, or subnodes preceding properties). */
106 #define FDT_ERR_BADLAYOUT	12
107 	/* FDT_ERR_BADLAYOUT: For read-write functions, the given
108 	 * device tree has it's sub-blocks in an order that the
109 	 * function can't handle (memory reserve map, then structure,
110 	 * then strings).  Use fdt_open_into() to reorganize the tree
111 	 * into a form suitable for the read-write operations. */
112 
113 /* "Can't happen" error indicating a bug in libfdt */
114 #define FDT_ERR_INTERNAL	13
115 	/* FDT_ERR_INTERNAL: libfdt has failed an internal assertion.
116 	 * Should never be returned, if it is, it indicates a bug in
117 	 * libfdt itself. */
118 
119 /* Errors in device tree content */
120 #define FDT_ERR_BADNCELLS	14
121 	/* FDT_ERR_BADNCELLS: Device tree has a #address-cells, #size-cells
122 	 * or similar property with a bad format or value */
123 
124 #define FDT_ERR_MAX		14
125 
126 /**********************************************************************/
127 /* Low-level functions (you probably don't need these)                */
128 /**********************************************************************/
129 
130 const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int checklen);
131 static inline void *fdt_offset_ptr_w(void *fdt, int offset, int checklen)
132 {
133 	return (void *)(uintptr_t)fdt_offset_ptr(fdt, offset, checklen);
134 }
135 
136 uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset);
137 
138 /**********************************************************************/
139 /* Traversal functions                                                */
140 /**********************************************************************/
141 
142 int fdt_next_node(const void *fdt, int offset, int *depth);
143 
144 /**
145  * fdt_first_subnode() - get offset of first direct subnode
146  *
147  * @fdt:	FDT blob
148  * @offset:	Offset of node to check
149  * @return offset of first subnode, or -FDT_ERR_NOTFOUND if there is none
150  */
151 int fdt_first_subnode(const void *fdt, int offset);
152 
153 /**
154  * fdt_next_subnode() - get offset of next direct subnode
155  *
156  * After first calling fdt_first_subnode(), call this function repeatedly to
157  * get direct subnodes of a parent node.
158  *
159  * @fdt:	FDT blob
160  * @offset:	Offset of previous subnode
161  * @return offset of next subnode, or -FDT_ERR_NOTFOUND if there are no more
162  * subnodes
163  */
164 int fdt_next_subnode(const void *fdt, int offset);
165 
166 /**********************************************************************/
167 /* General functions                                                  */
168 /**********************************************************************/
169 
170 #define fdt_get_header(fdt, field) \
171 	(fdt32_to_cpu(((const struct fdt_header *)(fdt))->field))
172 #define fdt_magic(fdt) 			(fdt_get_header(fdt, magic))
173 #define fdt_totalsize(fdt)		(fdt_get_header(fdt, totalsize))
174 #define fdt_off_dt_struct(fdt)		(fdt_get_header(fdt, off_dt_struct))
175 #define fdt_off_dt_strings(fdt)		(fdt_get_header(fdt, off_dt_strings))
176 #define fdt_off_mem_rsvmap(fdt)		(fdt_get_header(fdt, off_mem_rsvmap))
177 #define fdt_version(fdt)		(fdt_get_header(fdt, version))
178 #define fdt_last_comp_version(fdt) 	(fdt_get_header(fdt, last_comp_version))
179 #define fdt_boot_cpuid_phys(fdt) 	(fdt_get_header(fdt, boot_cpuid_phys))
180 #define fdt_size_dt_strings(fdt) 	(fdt_get_header(fdt, size_dt_strings))
181 #define fdt_size_dt_struct(fdt)		(fdt_get_header(fdt, size_dt_struct))
182 
183 #define __fdt_set_hdr(name) \
184 	static inline void fdt_set_##name(void *fdt, uint32_t val) \
185 	{ \
186 		struct fdt_header *fdth = (struct fdt_header*)fdt; \
187 		fdth->name = cpu_to_fdt32(val); \
188 	}
189 __fdt_set_hdr(magic);
190 __fdt_set_hdr(totalsize);
191 __fdt_set_hdr(off_dt_struct);
192 __fdt_set_hdr(off_dt_strings);
193 __fdt_set_hdr(off_mem_rsvmap);
194 __fdt_set_hdr(version);
195 __fdt_set_hdr(last_comp_version);
196 __fdt_set_hdr(boot_cpuid_phys);
197 __fdt_set_hdr(size_dt_strings);
198 __fdt_set_hdr(size_dt_struct);
199 #undef __fdt_set_hdr
200 
201 /**
202  * fdt_check_header - sanity check a device tree or possible device tree
203  * @fdt: pointer to data which might be a flattened device tree
204  *
205  * fdt_check_header() checks that the given buffer contains what
206  * appears to be a flattened device tree with sane information in its
207  * header.
208  *
209  * returns:
210  *     0, if the buffer appears to contain a valid device tree
211  *     -FDT_ERR_BADMAGIC,
212  *     -FDT_ERR_BADVERSION,
213  *     -FDT_ERR_BADSTATE, standard meanings, as above
214  */
215 int fdt_check_header(const void *fdt);
216 
217 /**
218  * fdt_move - move a device tree around in memory
219  * @fdt: pointer to the device tree to move
220  * @buf: pointer to memory where the device is to be moved
221  * @bufsize: size of the memory space at buf
222  *
223  * fdt_move() relocates, if possible, the device tree blob located at
224  * fdt to the buffer at buf of size bufsize.  The buffer may overlap
225  * with the existing device tree blob at fdt.  Therefore,
226  *     fdt_move(fdt, fdt, fdt_totalsize(fdt))
227  * should always succeed.
228  *
229  * returns:
230  *     0, on success
231  *     -FDT_ERR_NOSPACE, bufsize is insufficient to contain the device tree
232  *     -FDT_ERR_BADMAGIC,
233  *     -FDT_ERR_BADVERSION,
234  *     -FDT_ERR_BADSTATE, standard meanings
235  */
236 int fdt_move(const void *fdt, void *buf, int bufsize);
237 
238 /**********************************************************************/
239 /* Read-only functions                                                */
240 /**********************************************************************/
241 
242 /**
243  * fdt_string - retrieve a string from the strings block of a device tree
244  * @fdt: pointer to the device tree blob
245  * @stroffset: offset of the string within the strings block (native endian)
246  *
247  * fdt_string() retrieves a pointer to a single string from the
248  * strings block of the device tree blob at fdt.
249  *
250  * returns:
251  *     a pointer to the string, on success
252  *     NULL, if stroffset is out of bounds
253  */
254 const char *fdt_string(const void *fdt, int stroffset);
255 
256 /**
257  * fdt_num_mem_rsv - retrieve the number of memory reserve map entries
258  * @fdt: pointer to the device tree blob
259  *
260  * Returns the number of entries in the device tree blob's memory
261  * reservation map.  This does not include the terminating 0,0 entry
262  * or any other (0,0) entries reserved for expansion.
263  *
264  * returns:
265  *     the number of entries
266  */
267 int fdt_num_mem_rsv(const void *fdt);
268 
269 /**
270  * fdt_get_mem_rsv - retrieve one memory reserve map entry
271  * @fdt: pointer to the device tree blob
272  * @address, @size: pointers to 64-bit variables
273  *
274  * On success, *address and *size will contain the address and size of
275  * the n-th reserve map entry from the device tree blob, in
276  * native-endian format.
277  *
278  * returns:
279  *     0, on success
280  *     -FDT_ERR_BADMAGIC,
281  *     -FDT_ERR_BADVERSION,
282  *     -FDT_ERR_BADSTATE, standard meanings
283  */
284 int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size);
285 
286 /**
287  * fdt_subnode_offset_namelen - find a subnode based on substring
288  * @fdt: pointer to the device tree blob
289  * @parentoffset: structure block offset of a node
290  * @name: name of the subnode to locate
291  * @namelen: number of characters of name to consider
292  *
293  * Identical to fdt_subnode_offset(), but only examine the first
294  * namelen characters of name for matching the subnode name.  This is
295  * useful for finding subnodes based on a portion of a larger string,
296  * such as a full path.
297  */
298 int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
299 			       const char *name, int namelen);
300 /**
301  * fdt_subnode_offset - find a subnode of a given node
302  * @fdt: pointer to the device tree blob
303  * @parentoffset: structure block offset of a node
304  * @name: name of the subnode to locate
305  *
306  * fdt_subnode_offset() finds a subnode of the node at structure block
307  * offset parentoffset with the given name.  name may include a unit
308  * address, in which case fdt_subnode_offset() will find the subnode
309  * with that unit address, or the unit address may be omitted, in
310  * which case fdt_subnode_offset() will find an arbitrary subnode
311  * whose name excluding unit address matches the given name.
312  *
313  * returns:
314  *	structure block offset of the requested subnode (>=0), on success
315  *	-FDT_ERR_NOTFOUND, if the requested subnode does not exist
316  *	-FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag
317  *      -FDT_ERR_BADMAGIC,
318  *	-FDT_ERR_BADVERSION,
319  *	-FDT_ERR_BADSTATE,
320  *	-FDT_ERR_BADSTRUCTURE,
321  *	-FDT_ERR_TRUNCATED, standard meanings.
322  */
323 int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name);
324 
325 /**
326  * fdt_path_offset_namelen - find a tree node by its full path
327  * @fdt: pointer to the device tree blob
328  * @path: full path of the node to locate
329  * @namelen: number of characters of path to consider
330  *
331  * Identical to fdt_path_offset(), but only consider the first namelen
332  * characters of path as the path name.
333  */
334 int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen);
335 
336 /**
337  * fdt_path_offset - find a tree node by its full path
338  * @fdt: pointer to the device tree blob
339  * @path: full path of the node to locate
340  *
341  * fdt_path_offset() finds a node of a given path in the device tree.
342  * Each path component may omit the unit address portion, but the
343  * results of this are undefined if any such path component is
344  * ambiguous (that is if there are multiple nodes at the relevant
345  * level matching the given component, differentiated only by unit
346  * address).
347  *
348  * returns:
349  *	structure block offset of the node with the requested path (>=0), on success
350  *	-FDT_ERR_BADPATH, given path does not begin with '/' or is invalid
351  *	-FDT_ERR_NOTFOUND, if the requested node does not exist
352  *      -FDT_ERR_BADMAGIC,
353  *	-FDT_ERR_BADVERSION,
354  *	-FDT_ERR_BADSTATE,
355  *	-FDT_ERR_BADSTRUCTURE,
356  *	-FDT_ERR_TRUNCATED, standard meanings.
357  */
358 int fdt_path_offset(const void *fdt, const char *path);
359 
360 /**
361  * fdt_get_name - retrieve the name of a given node
362  * @fdt: pointer to the device tree blob
363  * @nodeoffset: structure block offset of the starting node
364  * @lenp: pointer to an integer variable (will be overwritten) or NULL
365  *
366  * fdt_get_name() retrieves the name (including unit address) of the
367  * device tree node at structure block offset nodeoffset.  If lenp is
368  * non-NULL, the length of this name is also returned, in the integer
369  * pointed to by lenp.
370  *
371  * returns:
372  *	pointer to the node's name, on success
373  *		If lenp is non-NULL, *lenp contains the length of that name (>=0)
374  *	NULL, on error
375  *		if lenp is non-NULL *lenp contains an error code (<0):
376  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
377  *		-FDT_ERR_BADMAGIC,
378  *		-FDT_ERR_BADVERSION,
379  *		-FDT_ERR_BADSTATE, standard meanings
380  */
381 const char *fdt_get_name(const void *fdt, int nodeoffset, int *lenp);
382 
383 /**
384  * fdt_first_property_offset - find the offset of a node's first property
385  * @fdt: pointer to the device tree blob
386  * @nodeoffset: structure block offset of a node
387  *
388  * fdt_first_property_offset() finds the first property of the node at
389  * the given structure block offset.
390  *
391  * returns:
392  *	structure block offset of the property (>=0), on success
393  *	-FDT_ERR_NOTFOUND, if the requested node has no properties
394  *	-FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_BEGIN_NODE tag
395  *      -FDT_ERR_BADMAGIC,
396  *	-FDT_ERR_BADVERSION,
397  *	-FDT_ERR_BADSTATE,
398  *	-FDT_ERR_BADSTRUCTURE,
399  *	-FDT_ERR_TRUNCATED, standard meanings.
400  */
401 int fdt_first_property_offset(const void *fdt, int nodeoffset);
402 
403 /**
404  * fdt_next_property_offset - step through a node's properties
405  * @fdt: pointer to the device tree blob
406  * @offset: structure block offset of a property
407  *
408  * fdt_next_property_offset() finds the property immediately after the
409  * one at the given structure block offset.  This will be a property
410  * of the same node as the given property.
411  *
412  * returns:
413  *	structure block offset of the next property (>=0), on success
414  *	-FDT_ERR_NOTFOUND, if the given property is the last in its node
415  *	-FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_PROP tag
416  *      -FDT_ERR_BADMAGIC,
417  *	-FDT_ERR_BADVERSION,
418  *	-FDT_ERR_BADSTATE,
419  *	-FDT_ERR_BADSTRUCTURE,
420  *	-FDT_ERR_TRUNCATED, standard meanings.
421  */
422 int fdt_next_property_offset(const void *fdt, int offset);
423 
424 /**
425  * fdt_get_property_by_offset - retrieve the property at a given offset
426  * @fdt: pointer to the device tree blob
427  * @offset: offset of the property to retrieve
428  * @lenp: pointer to an integer variable (will be overwritten) or NULL
429  *
430  * fdt_get_property_by_offset() retrieves a pointer to the
431  * fdt_property structure within the device tree blob at the given
432  * offset.  If lenp is non-NULL, the length of the property value is
433  * also returned, in the integer pointed to by lenp.
434  *
435  * returns:
436  *	pointer to the structure representing the property
437  *		if lenp is non-NULL, *lenp contains the length of the property
438  *		value (>=0)
439  *	NULL, on error
440  *		if lenp is non-NULL, *lenp contains an error code (<0):
441  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
442  *		-FDT_ERR_BADMAGIC,
443  *		-FDT_ERR_BADVERSION,
444  *		-FDT_ERR_BADSTATE,
445  *		-FDT_ERR_BADSTRUCTURE,
446  *		-FDT_ERR_TRUNCATED, standard meanings
447  */
448 const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
449 						      int offset,
450 						      int *lenp);
451 
452 /**
453  * fdt_get_property_namelen - find a property based on substring
454  * @fdt: pointer to the device tree blob
455  * @nodeoffset: offset of the node whose property to find
456  * @name: name of the property to find
457  * @namelen: number of characters of name to consider
458  * @lenp: pointer to an integer variable (will be overwritten) or NULL
459  *
460  * Identical to fdt_get_property_namelen(), but only examine the first
461  * namelen characters of name for matching the property name.
462  */
463 const struct fdt_property *fdt_get_property_namelen(const void *fdt,
464 						    int nodeoffset,
465 						    const char *name,
466 						    int namelen, int *lenp);
467 
468 /**
469  * fdt_get_property - find a given property in a given node
470  * @fdt: pointer to the device tree blob
471  * @nodeoffset: offset of the node whose property to find
472  * @name: name of the property to find
473  * @lenp: pointer to an integer variable (will be overwritten) or NULL
474  *
475  * fdt_get_property() retrieves a pointer to the fdt_property
476  * structure within the device tree blob corresponding to the property
477  * named 'name' of the node at offset nodeoffset.  If lenp is
478  * non-NULL, the length of the property value is also returned, in the
479  * integer pointed to by lenp.
480  *
481  * returns:
482  *	pointer to the structure representing the property
483  *		if lenp is non-NULL, *lenp contains the length of the property
484  *		value (>=0)
485  *	NULL, on error
486  *		if lenp is non-NULL, *lenp contains an error code (<0):
487  *		-FDT_ERR_NOTFOUND, node does not have named property
488  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
489  *		-FDT_ERR_BADMAGIC,
490  *		-FDT_ERR_BADVERSION,
491  *		-FDT_ERR_BADSTATE,
492  *		-FDT_ERR_BADSTRUCTURE,
493  *		-FDT_ERR_TRUNCATED, standard meanings
494  */
495 const struct fdt_property *fdt_get_property(const void *fdt, int nodeoffset,
496 					    const char *name, int *lenp);
497 static inline struct fdt_property *fdt_get_property_w(void *fdt, int nodeoffset,
498 						      const char *name,
499 						      int *lenp)
500 {
501 	return (struct fdt_property *)(uintptr_t)
502 		fdt_get_property(fdt, nodeoffset, name, lenp);
503 }
504 
505 /**
506  * fdt_getprop_by_offset - retrieve the value of a property at a given offset
507  * @fdt: pointer to the device tree blob
508  * @ffset: offset of the property to read
509  * @namep: pointer to a string variable (will be overwritten) or NULL
510  * @lenp: pointer to an integer variable (will be overwritten) or NULL
511  *
512  * fdt_getprop_by_offset() retrieves a pointer to the value of the
513  * property at structure block offset 'offset' (this will be a pointer
514  * to within the device blob itself, not a copy of the value).  If
515  * lenp is non-NULL, the length of the property value is also
516  * returned, in the integer pointed to by lenp.  If namep is non-NULL,
517  * the property's namne will also be returned in the char * pointed to
518  * by namep (this will be a pointer to within the device tree's string
519  * block, not a new copy of the name).
520  *
521  * returns:
522  *	pointer to the property's value
523  *		if lenp is non-NULL, *lenp contains the length of the property
524  *		value (>=0)
525  *		if namep is non-NULL *namep contiains a pointer to the property
526  *		name.
527  *	NULL, on error
528  *		if lenp is non-NULL, *lenp contains an error code (<0):
529  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
530  *		-FDT_ERR_BADMAGIC,
531  *		-FDT_ERR_BADVERSION,
532  *		-FDT_ERR_BADSTATE,
533  *		-FDT_ERR_BADSTRUCTURE,
534  *		-FDT_ERR_TRUNCATED, standard meanings
535  */
536 const void *fdt_getprop_by_offset(const void *fdt, int offset,
537 				  const char **namep, int *lenp);
538 
539 /**
540  * fdt_getprop_namelen - get property value based on substring
541  * @fdt: pointer to the device tree blob
542  * @nodeoffset: offset of the node whose property to find
543  * @name: name of the property to find
544  * @namelen: number of characters of name to consider
545  * @lenp: pointer to an integer variable (will be overwritten) or NULL
546  *
547  * Identical to fdt_getprop(), but only examine the first namelen
548  * characters of name for matching the property name.
549  */
550 const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
551 				const char *name, int namelen, int *lenp);
552 
553 /**
554  * fdt_getprop - retrieve the value of a given property
555  * @fdt: pointer to the device tree blob
556  * @nodeoffset: offset of the node whose property to find
557  * @name: name of the property to find
558  * @lenp: pointer to an integer variable (will be overwritten) or NULL
559  *
560  * fdt_getprop() retrieves a pointer to the value of the property
561  * named 'name' of the node at offset nodeoffset (this will be a
562  * pointer to within the device blob itself, not a copy of the value).
563  * If lenp is non-NULL, the length of the property value is also
564  * returned, in the integer pointed to by lenp.
565  *
566  * returns:
567  *	pointer to the property's value
568  *		if lenp is non-NULL, *lenp contains the length of the property
569  *		value (>=0)
570  *	NULL, on error
571  *		if lenp is non-NULL, *lenp contains an error code (<0):
572  *		-FDT_ERR_NOTFOUND, node does not have named property
573  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
574  *		-FDT_ERR_BADMAGIC,
575  *		-FDT_ERR_BADVERSION,
576  *		-FDT_ERR_BADSTATE,
577  *		-FDT_ERR_BADSTRUCTURE,
578  *		-FDT_ERR_TRUNCATED, standard meanings
579  */
580 const void *fdt_getprop(const void *fdt, int nodeoffset,
581 			const char *name, int *lenp);
582 static inline void *fdt_getprop_w(void *fdt, int nodeoffset,
583 				  const char *name, int *lenp)
584 {
585 	return (void *)(uintptr_t)fdt_getprop(fdt, nodeoffset, name, lenp);
586 }
587 
588 /**
589  * fdt_get_phandle - retrieve the phandle of a given node
590  * @fdt: pointer to the device tree blob
591  * @nodeoffset: structure block offset of the node
592  *
593  * fdt_get_phandle() retrieves the phandle of the device tree node at
594  * structure block offset nodeoffset.
595  *
596  * returns:
597  *	the phandle of the node at nodeoffset, on success (!= 0, != -1)
598  *	0, if the node has no phandle, or another error occurs
599  */
600 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset);
601 
602 /**
603  * fdt_get_alias_namelen - get alias based on substring
604  * @fdt: pointer to the device tree blob
605  * @name: name of the alias th look up
606  * @namelen: number of characters of name to consider
607  *
608  * Identical to fdt_get_alias(), but only examine the first namelen
609  * characters of name for matching the alias name.
610  */
611 const char *fdt_get_alias_namelen(const void *fdt,
612 				  const char *name, int namelen);
613 
614 /**
615  * fdt_get_alias - retreive the path referenced by a given alias
616  * @fdt: pointer to the device tree blob
617  * @name: name of the alias th look up
618  *
619  * fdt_get_alias() retrieves the value of a given alias.  That is, the
620  * value of the property named 'name' in the node /aliases.
621  *
622  * returns:
623  *	a pointer to the expansion of the alias named 'name', if it exists
624  *	NULL, if the given alias or the /aliases node does not exist
625  */
626 const char *fdt_get_alias(const void *fdt, const char *name);
627 
628 /**
629  * fdt_get_path - determine the full path of a node
630  * @fdt: pointer to the device tree blob
631  * @nodeoffset: offset of the node whose path to find
632  * @buf: character buffer to contain the returned path (will be overwritten)
633  * @buflen: size of the character buffer at buf
634  *
635  * fdt_get_path() computes the full path of the node at offset
636  * nodeoffset, and records that path in the buffer at buf.
637  *
638  * NOTE: This function is expensive, as it must scan the device tree
639  * structure from the start to nodeoffset.
640  *
641  * returns:
642  *	0, on success
643  *		buf contains the absolute path of the node at
644  *		nodeoffset, as a NUL-terminated string.
645  * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
646  *	-FDT_ERR_NOSPACE, the path of the given node is longer than (bufsize-1)
647  *		characters and will not fit in the given buffer.
648  *	-FDT_ERR_BADMAGIC,
649  *	-FDT_ERR_BADVERSION,
650  *	-FDT_ERR_BADSTATE,
651  *	-FDT_ERR_BADSTRUCTURE, standard meanings
652  */
653 int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen);
654 
655 /**
656  * fdt_supernode_atdepth_offset - find a specific ancestor of a node
657  * @fdt: pointer to the device tree blob
658  * @nodeoffset: offset of the node whose parent to find
659  * @supernodedepth: depth of the ancestor to find
660  * @nodedepth: pointer to an integer variable (will be overwritten) or NULL
661  *
662  * fdt_supernode_atdepth_offset() finds an ancestor of the given node
663  * at a specific depth from the root (where the root itself has depth
664  * 0, its immediate subnodes depth 1 and so forth).  So
665  *	fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, NULL);
666  * will always return 0, the offset of the root node.  If the node at
667  * nodeoffset has depth D, then:
668  *	fdt_supernode_atdepth_offset(fdt, nodeoffset, D, NULL);
669  * will return nodeoffset itself.
670  *
671  * NOTE: This function is expensive, as it must scan the device tree
672  * structure from the start to nodeoffset.
673  *
674  * returns:
675 
676  *	structure block offset of the node at node offset's ancestor
677  *		of depth supernodedepth (>=0), on success
678  * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
679 *	-FDT_ERR_NOTFOUND, supernodedepth was greater than the depth of nodeoffset
680  *	-FDT_ERR_BADMAGIC,
681  *	-FDT_ERR_BADVERSION,
682  *	-FDT_ERR_BADSTATE,
683  *	-FDT_ERR_BADSTRUCTURE, standard meanings
684  */
685 int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
686 				 int supernodedepth, int *nodedepth);
687 
688 /**
689  * fdt_node_depth - find the depth of a given node
690  * @fdt: pointer to the device tree blob
691  * @nodeoffset: offset of the node whose parent to find
692  *
693  * fdt_node_depth() finds the depth of a given node.  The root node
694  * has depth 0, its immediate subnodes depth 1 and so forth.
695  *
696  * NOTE: This function is expensive, as it must scan the device tree
697  * structure from the start to nodeoffset.
698  *
699  * returns:
700  *	depth of the node at nodeoffset (>=0), on success
701  * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
702  *	-FDT_ERR_BADMAGIC,
703  *	-FDT_ERR_BADVERSION,
704  *	-FDT_ERR_BADSTATE,
705  *	-FDT_ERR_BADSTRUCTURE, standard meanings
706  */
707 int fdt_node_depth(const void *fdt, int nodeoffset);
708 
709 /**
710  * fdt_parent_offset - find the parent of a given node
711  * @fdt: pointer to the device tree blob
712  * @nodeoffset: offset of the node whose parent to find
713  *
714  * fdt_parent_offset() locates the parent node of a given node (that
715  * is, it finds the offset of the node which contains the node at
716  * nodeoffset as a subnode).
717  *
718  * NOTE: This function is expensive, as it must scan the device tree
719  * structure from the start to nodeoffset, *twice*.
720  *
721  * returns:
722  *	structure block offset of the parent of the node at nodeoffset
723  *		(>=0), on success
724  * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
725  *	-FDT_ERR_BADMAGIC,
726  *	-FDT_ERR_BADVERSION,
727  *	-FDT_ERR_BADSTATE,
728  *	-FDT_ERR_BADSTRUCTURE, standard meanings
729  */
730 int fdt_parent_offset(const void *fdt, int nodeoffset);
731 
732 /**
733  * fdt_node_offset_by_prop_value - find nodes with a given property value
734  * @fdt: pointer to the device tree blob
735  * @startoffset: only find nodes after this offset
736  * @propname: property name to check
737  * @propval: property value to search for
738  * @proplen: length of the value in propval
739  *
740  * fdt_node_offset_by_prop_value() returns the offset of the first
741  * node after startoffset, which has a property named propname whose
742  * value is of length proplen and has value equal to propval; or if
743  * startoffset is -1, the very first such node in the tree.
744  *
745  * To iterate through all nodes matching the criterion, the following
746  * idiom can be used:
747  *	offset = fdt_node_offset_by_prop_value(fdt, -1, propname,
748  *					       propval, proplen);
749  *	while (offset != -FDT_ERR_NOTFOUND) {
750  *		// other code here
751  *		offset = fdt_node_offset_by_prop_value(fdt, offset, propname,
752  *						       propval, proplen);
753  *	}
754  *
755  * Note the -1 in the first call to the function, if 0 is used here
756  * instead, the function will never locate the root node, even if it
757  * matches the criterion.
758  *
759  * returns:
760  *	structure block offset of the located node (>= 0, >startoffset),
761  *		 on success
762  *	-FDT_ERR_NOTFOUND, no node matching the criterion exists in the
763  *		tree after startoffset
764  * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
765  *	-FDT_ERR_BADMAGIC,
766  *	-FDT_ERR_BADVERSION,
767  *	-FDT_ERR_BADSTATE,
768  *	-FDT_ERR_BADSTRUCTURE, standard meanings
769  */
770 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
771 				  const char *propname,
772 				  const void *propval, int proplen);
773 
774 /**
775  * fdt_node_offset_by_phandle - find the node with a given phandle
776  * @fdt: pointer to the device tree blob
777  * @phandle: phandle value
778  *
779  * fdt_node_offset_by_phandle() returns the offset of the node
780  * which has the given phandle value.  If there is more than one node
781  * in the tree with the given phandle (an invalid tree), results are
782  * undefined.
783  *
784  * returns:
785  *	structure block offset of the located node (>= 0), on success
786  *	-FDT_ERR_NOTFOUND, no node with that phandle exists
787  *	-FDT_ERR_BADPHANDLE, given phandle value was invalid (0 or -1)
788  *	-FDT_ERR_BADMAGIC,
789  *	-FDT_ERR_BADVERSION,
790  *	-FDT_ERR_BADSTATE,
791  *	-FDT_ERR_BADSTRUCTURE, standard meanings
792  */
793 int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle);
794 
795 /**
796  * fdt_node_check_compatible: check a node's compatible property
797  * @fdt: pointer to the device tree blob
798  * @nodeoffset: offset of a tree node
799  * @compatible: string to match against
800  *
801  *
802  * fdt_node_check_compatible() returns 0 if the given node contains a
803  * 'compatible' property with the given string as one of its elements,
804  * it returns non-zero otherwise, or on error.
805  *
806  * returns:
807  *	0, if the node has a 'compatible' property listing the given string
808  *	1, if the node has a 'compatible' property, but it does not list
809  *		the given string
810  *	-FDT_ERR_NOTFOUND, if the given node has no 'compatible' property
811  * 	-FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag
812  *	-FDT_ERR_BADMAGIC,
813  *	-FDT_ERR_BADVERSION,
814  *	-FDT_ERR_BADSTATE,
815  *	-FDT_ERR_BADSTRUCTURE, standard meanings
816  */
817 int fdt_node_check_compatible(const void *fdt, int nodeoffset,
818 			      const char *compatible);
819 
820 /**
821  * fdt_node_offset_by_compatible - find nodes with a given 'compatible' value
822  * @fdt: pointer to the device tree blob
823  * @startoffset: only find nodes after this offset
824  * @compatible: 'compatible' string to match against
825  *
826  * fdt_node_offset_by_compatible() returns the offset of the first
827  * node after startoffset, which has a 'compatible' property which
828  * lists the given compatible string; or if startoffset is -1, the
829  * very first such node in the tree.
830  *
831  * To iterate through all nodes matching the criterion, the following
832  * idiom can be used:
833  *	offset = fdt_node_offset_by_compatible(fdt, -1, compatible);
834  *	while (offset != -FDT_ERR_NOTFOUND) {
835  *		// other code here
836  *		offset = fdt_node_offset_by_compatible(fdt, offset, compatible);
837  *	}
838  *
839  * Note the -1 in the first call to the function, if 0 is used here
840  * instead, the function will never locate the root node, even if it
841  * matches the criterion.
842  *
843  * returns:
844  *	structure block offset of the located node (>= 0, >startoffset),
845  *		 on success
846  *	-FDT_ERR_NOTFOUND, no node matching the criterion exists in the
847  *		tree after startoffset
848  * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
849  *	-FDT_ERR_BADMAGIC,
850  *	-FDT_ERR_BADVERSION,
851  *	-FDT_ERR_BADSTATE,
852  *	-FDT_ERR_BADSTRUCTURE, standard meanings
853  */
854 int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
855 				  const char *compatible);
856 
857 /**
858  * fdt_stringlist_contains - check a string list property for a string
859  * @strlist: Property containing a list of strings to check
860  * @listlen: Length of property
861  * @str: String to search for
862  *
863  * This is a utility function provided for convenience. The list contains
864  * one or more strings, each terminated by \0, as is found in a device tree
865  * "compatible" property.
866  *
867  * @return: 1 if the string is found in the list, 0 not found, or invalid list
868  */
869 int fdt_stringlist_contains(const char *strlist, int listlen, const char *str);
870 
871 /**********************************************************************/
872 /* Read-only functions (addressing related)                           */
873 /**********************************************************************/
874 
875 /**
876  * FDT_MAX_NCELLS - maximum value for #address-cells and #size-cells
877  *
878  * This is the maximum value for #address-cells, #size-cells and
879  * similar properties that will be processed by libfdt.  IEE1275
880  * requires that OF implementations handle values up to 4.
881  * Implementations may support larger values, but in practice higher
882  * values aren't used.
883  */
884 #define FDT_MAX_NCELLS		4
885 
886 /**
887  * fdt_address_cells - retrieve address size for a bus represented in the tree
888  * @fdt: pointer to the device tree blob
889  * @nodeoffset: offset of the node to find the address size for
890  *
891  * When the node has a valid #address-cells property, returns its value.
892  *
893  * returns:
894  *	0 <= n < FDT_MAX_NCELLS, on success
895  *      2, if the node has no #address-cells property
896  *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid #address-cells property
897  *	-FDT_ERR_BADMAGIC,
898  *	-FDT_ERR_BADVERSION,
899  *	-FDT_ERR_BADSTATE,
900  *	-FDT_ERR_BADSTRUCTURE,
901  *	-FDT_ERR_TRUNCATED, standard meanings
902  */
903 int fdt_address_cells(const void *fdt, int nodeoffset);
904 
905 /**
906  * fdt_size_cells - retrieve address range size for a bus represented in the
907  *                  tree
908  * @fdt: pointer to the device tree blob
909  * @nodeoffset: offset of the node to find the address range size for
910  *
911  * When the node has a valid #size-cells property, returns its value.
912  *
913  * returns:
914  *	0 <= n < FDT_MAX_NCELLS, on success
915  *      2, if the node has no #address-cells property
916  *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid #size-cells property
917  *	-FDT_ERR_BADMAGIC,
918  *	-FDT_ERR_BADVERSION,
919  *	-FDT_ERR_BADSTATE,
920  *	-FDT_ERR_BADSTRUCTURE,
921  *	-FDT_ERR_TRUNCATED, standard meanings
922  */
923 int fdt_size_cells(const void *fdt, int nodeoffset);
924 
925 
926 /**********************************************************************/
927 /* Write-in-place functions                                           */
928 /**********************************************************************/
929 
930 /**
931  * fdt_setprop_inplace - change a property's value, but not its size
932  * @fdt: pointer to the device tree blob
933  * @nodeoffset: offset of the node whose property to change
934  * @name: name of the property to change
935  * @val: pointer to data to replace the property value with
936  * @len: length of the property value
937  *
938  * fdt_setprop_inplace() replaces the value of a given property with
939  * the data in val, of length len.  This function cannot change the
940  * size of a property, and so will only work if len is equal to the
941  * current length of the property.
942  *
943  * This function will alter only the bytes in the blob which contain
944  * the given property value, and will not alter or move any other part
945  * of the tree.
946  *
947  * returns:
948  *	0, on success
949  *	-FDT_ERR_NOSPACE, if len is not equal to the property's current length
950  *	-FDT_ERR_NOTFOUND, node does not have the named property
951  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
952  *	-FDT_ERR_BADMAGIC,
953  *	-FDT_ERR_BADVERSION,
954  *	-FDT_ERR_BADSTATE,
955  *	-FDT_ERR_BADSTRUCTURE,
956  *	-FDT_ERR_TRUNCATED, standard meanings
957  */
958 int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
959 			const void *val, int len);
960 
961 /**
962  * fdt_setprop_inplace_u32 - change the value of a 32-bit integer property
963  * @fdt: pointer to the device tree blob
964  * @nodeoffset: offset of the node whose property to change
965  * @name: name of the property to change
966  * @val: 32-bit integer value to replace the property with
967  *
968  * fdt_setprop_inplace_u32() replaces the value of a given property
969  * with the 32-bit integer value in val, converting val to big-endian
970  * if necessary.  This function cannot change the size of a property,
971  * and so will only work if the property already exists and has length
972  * 4.
973  *
974  * This function will alter only the bytes in the blob which contain
975  * the given property value, and will not alter or move any other part
976  * of the tree.
977  *
978  * returns:
979  *	0, on success
980  *	-FDT_ERR_NOSPACE, if the property's length is not equal to 4
981  *	-FDT_ERR_NOTFOUND, node does not have the named property
982  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
983  *	-FDT_ERR_BADMAGIC,
984  *	-FDT_ERR_BADVERSION,
985  *	-FDT_ERR_BADSTATE,
986  *	-FDT_ERR_BADSTRUCTURE,
987  *	-FDT_ERR_TRUNCATED, standard meanings
988  */
989 static inline int fdt_setprop_inplace_u32(void *fdt, int nodeoffset,
990 					  const char *name, uint32_t val)
991 {
992 	fdt32_t tmp = cpu_to_fdt32(val);
993 	return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
994 }
995 
996 /**
997  * fdt_setprop_inplace_u64 - change the value of a 64-bit integer property
998  * @fdt: pointer to the device tree blob
999  * @nodeoffset: offset of the node whose property to change
1000  * @name: name of the property to change
1001  * @val: 64-bit integer value to replace the property with
1002  *
1003  * fdt_setprop_inplace_u64() replaces the value of a given property
1004  * with the 64-bit integer value in val, converting val to big-endian
1005  * if necessary.  This function cannot change the size of a property,
1006  * and so will only work if the property already exists and has length
1007  * 8.
1008  *
1009  * This function will alter only the bytes in the blob which contain
1010  * the given property value, and will not alter or move any other part
1011  * of the tree.
1012  *
1013  * returns:
1014  *	0, on success
1015  *	-FDT_ERR_NOSPACE, if the property's length is not equal to 8
1016  *	-FDT_ERR_NOTFOUND, node does not have the named property
1017  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1018  *	-FDT_ERR_BADMAGIC,
1019  *	-FDT_ERR_BADVERSION,
1020  *	-FDT_ERR_BADSTATE,
1021  *	-FDT_ERR_BADSTRUCTURE,
1022  *	-FDT_ERR_TRUNCATED, standard meanings
1023  */
1024 static inline int fdt_setprop_inplace_u64(void *fdt, int nodeoffset,
1025 					  const char *name, uint64_t val)
1026 {
1027 	fdt64_t tmp = cpu_to_fdt64(val);
1028 	return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1029 }
1030 
1031 /**
1032  * fdt_setprop_inplace_cell - change the value of a single-cell property
1033  *
1034  * This is an alternative name for fdt_setprop_inplace_u32()
1035  */
1036 static inline int fdt_setprop_inplace_cell(void *fdt, int nodeoffset,
1037 					   const char *name, uint32_t val)
1038 {
1039 	return fdt_setprop_inplace_u32(fdt, nodeoffset, name, val);
1040 }
1041 
1042 /**
1043  * fdt_nop_property - replace a property with nop tags
1044  * @fdt: pointer to the device tree blob
1045  * @nodeoffset: offset of the node whose property to nop
1046  * @name: name of the property to nop
1047  *
1048  * fdt_nop_property() will replace a given property's representation
1049  * in the blob with FDT_NOP tags, effectively removing it from the
1050  * tree.
1051  *
1052  * This function will alter only the bytes in the blob which contain
1053  * the property, and will not alter or move any other part of the
1054  * tree.
1055  *
1056  * returns:
1057  *	0, on success
1058  *	-FDT_ERR_NOTFOUND, node does not have the named property
1059  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1060  *	-FDT_ERR_BADMAGIC,
1061  *	-FDT_ERR_BADVERSION,
1062  *	-FDT_ERR_BADSTATE,
1063  *	-FDT_ERR_BADSTRUCTURE,
1064  *	-FDT_ERR_TRUNCATED, standard meanings
1065  */
1066 int fdt_nop_property(void *fdt, int nodeoffset, const char *name);
1067 
1068 /**
1069  * fdt_nop_node - replace a node (subtree) with nop tags
1070  * @fdt: pointer to the device tree blob
1071  * @nodeoffset: offset of the node to nop
1072  *
1073  * fdt_nop_node() will replace a given node's representation in the
1074  * blob, including all its subnodes, if any, with FDT_NOP tags,
1075  * effectively removing it from the tree.
1076  *
1077  * This function will alter only the bytes in the blob which contain
1078  * the node and its properties and subnodes, and will not alter or
1079  * move any other part of the tree.
1080  *
1081  * returns:
1082  *	0, on success
1083  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1084  *	-FDT_ERR_BADMAGIC,
1085  *	-FDT_ERR_BADVERSION,
1086  *	-FDT_ERR_BADSTATE,
1087  *	-FDT_ERR_BADSTRUCTURE,
1088  *	-FDT_ERR_TRUNCATED, standard meanings
1089  */
1090 int fdt_nop_node(void *fdt, int nodeoffset);
1091 
1092 /**********************************************************************/
1093 /* Sequential write functions                                         */
1094 /**********************************************************************/
1095 
1096 int fdt_create(void *buf, int bufsize);
1097 int fdt_resize(void *fdt, void *buf, int bufsize);
1098 int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size);
1099 int fdt_finish_reservemap(void *fdt);
1100 int fdt_begin_node(void *fdt, const char *name);
1101 int fdt_property(void *fdt, const char *name, const void *val, int len);
1102 static inline int fdt_property_u32(void *fdt, const char *name, uint32_t val)
1103 {
1104 	fdt32_t tmp = cpu_to_fdt32(val);
1105 	return fdt_property(fdt, name, &tmp, sizeof(tmp));
1106 }
1107 static inline int fdt_property_u64(void *fdt, const char *name, uint64_t val)
1108 {
1109 	fdt64_t tmp = cpu_to_fdt64(val);
1110 	return fdt_property(fdt, name, &tmp, sizeof(tmp));
1111 }
1112 static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val)
1113 {
1114 	return fdt_property_u32(fdt, name, val);
1115 }
1116 #define fdt_property_string(fdt, name, str) \
1117 	fdt_property(fdt, name, str, strlen(str)+1)
1118 int fdt_end_node(void *fdt);
1119 int fdt_finish(void *fdt);
1120 
1121 /**********************************************************************/
1122 /* Read-write functions                                               */
1123 /**********************************************************************/
1124 
1125 int fdt_create_empty_tree(void *buf, int bufsize);
1126 int fdt_open_into(const void *fdt, void *buf, int bufsize);
1127 int fdt_pack(void *fdt);
1128 
1129 /**
1130  * fdt_add_mem_rsv - add one memory reserve map entry
1131  * @fdt: pointer to the device tree blob
1132  * @address, @size: 64-bit values (native endian)
1133  *
1134  * Adds a reserve map entry to the given blob reserving a region at
1135  * address address of length size.
1136  *
1137  * This function will insert data into the reserve map and will
1138  * therefore change the indexes of some entries in the table.
1139  *
1140  * returns:
1141  *	0, on success
1142  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1143  *		contain the new reservation entry
1144  *	-FDT_ERR_BADMAGIC,
1145  *	-FDT_ERR_BADVERSION,
1146  *	-FDT_ERR_BADSTATE,
1147  *	-FDT_ERR_BADSTRUCTURE,
1148  *	-FDT_ERR_BADLAYOUT,
1149  *	-FDT_ERR_TRUNCATED, standard meanings
1150  */
1151 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size);
1152 
1153 /**
1154  * fdt_del_mem_rsv - remove a memory reserve map entry
1155  * @fdt: pointer to the device tree blob
1156  * @n: entry to remove
1157  *
1158  * fdt_del_mem_rsv() removes the n-th memory reserve map entry from
1159  * the blob.
1160  *
1161  * This function will delete data from the reservation table and will
1162  * therefore change the indexes of some entries in the table.
1163  *
1164  * returns:
1165  *	0, on success
1166  *	-FDT_ERR_NOTFOUND, there is no entry of the given index (i.e. there
1167  *		are less than n+1 reserve map entries)
1168  *	-FDT_ERR_BADMAGIC,
1169  *	-FDT_ERR_BADVERSION,
1170  *	-FDT_ERR_BADSTATE,
1171  *	-FDT_ERR_BADSTRUCTURE,
1172  *	-FDT_ERR_BADLAYOUT,
1173  *	-FDT_ERR_TRUNCATED, standard meanings
1174  */
1175 int fdt_del_mem_rsv(void *fdt, int n);
1176 
1177 /**
1178  * fdt_set_name - change the name of a given node
1179  * @fdt: pointer to the device tree blob
1180  * @nodeoffset: structure block offset of a node
1181  * @name: name to give the node
1182  *
1183  * fdt_set_name() replaces the name (including unit address, if any)
1184  * of the given node with the given string.  NOTE: this function can't
1185  * efficiently check if the new name is unique amongst the given
1186  * node's siblings; results are undefined if this function is invoked
1187  * with a name equal to one of the given node's siblings.
1188  *
1189  * This function may insert or delete data from the blob, and will
1190  * therefore change the offsets of some existing nodes.
1191  *
1192  * returns:
1193  *	0, on success
1194  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob
1195  *		to contain the new name
1196  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1197  *	-FDT_ERR_BADMAGIC,
1198  *	-FDT_ERR_BADVERSION,
1199  *	-FDT_ERR_BADSTATE, standard meanings
1200  */
1201 int fdt_set_name(void *fdt, int nodeoffset, const char *name);
1202 
1203 /**
1204  * fdt_setprop - create or change a property
1205  * @fdt: pointer to the device tree blob
1206  * @nodeoffset: offset of the node whose property to change
1207  * @name: name of the property to change
1208  * @val: pointer to data to set the property value to
1209  * @len: length of the property value
1210  *
1211  * fdt_setprop() sets the value of the named property in the given
1212  * node to the given value and length, creating the property if it
1213  * does not already exist.
1214  *
1215  * This function may insert or delete data from the blob, and will
1216  * therefore change the offsets of some existing nodes.
1217  *
1218  * returns:
1219  *	0, on success
1220  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1221  *		contain the new property value
1222  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1223  *	-FDT_ERR_BADLAYOUT,
1224  *	-FDT_ERR_BADMAGIC,
1225  *	-FDT_ERR_BADVERSION,
1226  *	-FDT_ERR_BADSTATE,
1227  *	-FDT_ERR_BADSTRUCTURE,
1228  *	-FDT_ERR_BADLAYOUT,
1229  *	-FDT_ERR_TRUNCATED, standard meanings
1230  */
1231 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
1232 		const void *val, int len);
1233 
1234 /**
1235  * fdt_setprop_u32 - set a property to a 32-bit integer
1236  * @fdt: pointer to the device tree blob
1237  * @nodeoffset: offset of the node whose property to change
1238  * @name: name of the property to change
1239  * @val: 32-bit integer value for the property (native endian)
1240  *
1241  * fdt_setprop_u32() sets the value of the named property in the given
1242  * node to the given 32-bit integer value (converting to big-endian if
1243  * necessary), or creates a new property with that value if it does
1244  * not already exist.
1245  *
1246  * This function may insert or delete data from the blob, and will
1247  * therefore change the offsets of some existing nodes.
1248  *
1249  * returns:
1250  *	0, on success
1251  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1252  *		contain the new property value
1253  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1254  *	-FDT_ERR_BADLAYOUT,
1255  *	-FDT_ERR_BADMAGIC,
1256  *	-FDT_ERR_BADVERSION,
1257  *	-FDT_ERR_BADSTATE,
1258  *	-FDT_ERR_BADSTRUCTURE,
1259  *	-FDT_ERR_BADLAYOUT,
1260  *	-FDT_ERR_TRUNCATED, standard meanings
1261  */
1262 static inline int fdt_setprop_u32(void *fdt, int nodeoffset, const char *name,
1263 				  uint32_t val)
1264 {
1265 	fdt32_t tmp = cpu_to_fdt32(val);
1266 	return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1267 }
1268 
1269 /**
1270  * fdt_setprop_u64 - set a property to a 64-bit integer
1271  * @fdt: pointer to the device tree blob
1272  * @nodeoffset: offset of the node whose property to change
1273  * @name: name of the property to change
1274  * @val: 64-bit integer value for the property (native endian)
1275  *
1276  * fdt_setprop_u64() sets the value of the named property in the given
1277  * node to the given 64-bit integer value (converting to big-endian if
1278  * necessary), or creates a new property with that value if it does
1279  * not already exist.
1280  *
1281  * This function may insert or delete data from the blob, and will
1282  * therefore change the offsets of some existing nodes.
1283  *
1284  * returns:
1285  *	0, on success
1286  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1287  *		contain the new property value
1288  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1289  *	-FDT_ERR_BADLAYOUT,
1290  *	-FDT_ERR_BADMAGIC,
1291  *	-FDT_ERR_BADVERSION,
1292  *	-FDT_ERR_BADSTATE,
1293  *	-FDT_ERR_BADSTRUCTURE,
1294  *	-FDT_ERR_BADLAYOUT,
1295  *	-FDT_ERR_TRUNCATED, standard meanings
1296  */
1297 static inline int fdt_setprop_u64(void *fdt, int nodeoffset, const char *name,
1298 				  uint64_t val)
1299 {
1300 	fdt64_t tmp = cpu_to_fdt64(val);
1301 	return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1302 }
1303 
1304 /**
1305  * fdt_setprop_cell - set a property to a single cell value
1306  *
1307  * This is an alternative name for fdt_setprop_u32()
1308  */
1309 static inline int fdt_setprop_cell(void *fdt, int nodeoffset, const char *name,
1310 				   uint32_t val)
1311 {
1312 	return fdt_setprop_u32(fdt, nodeoffset, name, val);
1313 }
1314 
1315 /**
1316  * fdt_setprop_string - set a property to a string value
1317  * @fdt: pointer to the device tree blob
1318  * @nodeoffset: offset of the node whose property to change
1319  * @name: name of the property to change
1320  * @str: string value for the property
1321  *
1322  * fdt_setprop_string() sets the value of the named property in the
1323  * given node to the given string value (using the length of the
1324  * string to determine the new length of the property), or creates a
1325  * new property with that value if it does not already exist.
1326  *
1327  * This function may insert or delete data from the blob, and will
1328  * therefore change the offsets of some existing nodes.
1329  *
1330  * returns:
1331  *	0, on success
1332  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1333  *		contain the new property value
1334  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1335  *	-FDT_ERR_BADLAYOUT,
1336  *	-FDT_ERR_BADMAGIC,
1337  *	-FDT_ERR_BADVERSION,
1338  *	-FDT_ERR_BADSTATE,
1339  *	-FDT_ERR_BADSTRUCTURE,
1340  *	-FDT_ERR_BADLAYOUT,
1341  *	-FDT_ERR_TRUNCATED, standard meanings
1342  */
1343 #define fdt_setprop_string(fdt, nodeoffset, name, str) \
1344 	fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1345 
1346 /**
1347  * fdt_appendprop - append to or create a property
1348  * @fdt: pointer to the device tree blob
1349  * @nodeoffset: offset of the node whose property to change
1350  * @name: name of the property to append to
1351  * @val: pointer to data to append to the property value
1352  * @len: length of the data to append to the property value
1353  *
1354  * fdt_appendprop() appends the value to the named property in the
1355  * given node, creating the property if it does not already exist.
1356  *
1357  * This function may insert data into the blob, and will therefore
1358  * change the offsets of some existing nodes.
1359  *
1360  * returns:
1361  *	0, on success
1362  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1363  *		contain the new property value
1364  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1365  *	-FDT_ERR_BADLAYOUT,
1366  *	-FDT_ERR_BADMAGIC,
1367  *	-FDT_ERR_BADVERSION,
1368  *	-FDT_ERR_BADSTATE,
1369  *	-FDT_ERR_BADSTRUCTURE,
1370  *	-FDT_ERR_BADLAYOUT,
1371  *	-FDT_ERR_TRUNCATED, standard meanings
1372  */
1373 int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
1374 		   const void *val, int len);
1375 
1376 /**
1377  * fdt_appendprop_u32 - append a 32-bit integer value to a property
1378  * @fdt: pointer to the device tree blob
1379  * @nodeoffset: offset of the node whose property to change
1380  * @name: name of the property to change
1381  * @val: 32-bit integer value to append to the property (native endian)
1382  *
1383  * fdt_appendprop_u32() appends the given 32-bit integer value
1384  * (converting to big-endian if necessary) to the value of the named
1385  * property in the given node, or creates a new property with that
1386  * value if it does not already exist.
1387  *
1388  * This function may insert data into the blob, and will therefore
1389  * change the offsets of some existing nodes.
1390  *
1391  * returns:
1392  *	0, on success
1393  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1394  *		contain the new property value
1395  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1396  *	-FDT_ERR_BADLAYOUT,
1397  *	-FDT_ERR_BADMAGIC,
1398  *	-FDT_ERR_BADVERSION,
1399  *	-FDT_ERR_BADSTATE,
1400  *	-FDT_ERR_BADSTRUCTURE,
1401  *	-FDT_ERR_BADLAYOUT,
1402  *	-FDT_ERR_TRUNCATED, standard meanings
1403  */
1404 static inline int fdt_appendprop_u32(void *fdt, int nodeoffset,
1405 				     const char *name, uint32_t val)
1406 {
1407 	fdt32_t tmp = cpu_to_fdt32(val);
1408 	return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1409 }
1410 
1411 /**
1412  * fdt_appendprop_u64 - append a 64-bit integer value to a property
1413  * @fdt: pointer to the device tree blob
1414  * @nodeoffset: offset of the node whose property to change
1415  * @name: name of the property to change
1416  * @val: 64-bit integer value to append to the property (native endian)
1417  *
1418  * fdt_appendprop_u64() appends the given 64-bit integer value
1419  * (converting to big-endian if necessary) to the value of the named
1420  * property in the given node, or creates a new property with that
1421  * value if it does not already exist.
1422  *
1423  * This function may insert data into the blob, and will therefore
1424  * change the offsets of some existing nodes.
1425  *
1426  * returns:
1427  *	0, on success
1428  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1429  *		contain the new property value
1430  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1431  *	-FDT_ERR_BADLAYOUT,
1432  *	-FDT_ERR_BADMAGIC,
1433  *	-FDT_ERR_BADVERSION,
1434  *	-FDT_ERR_BADSTATE,
1435  *	-FDT_ERR_BADSTRUCTURE,
1436  *	-FDT_ERR_BADLAYOUT,
1437  *	-FDT_ERR_TRUNCATED, standard meanings
1438  */
1439 static inline int fdt_appendprop_u64(void *fdt, int nodeoffset,
1440 				     const char *name, uint64_t val)
1441 {
1442 	fdt64_t tmp = cpu_to_fdt64(val);
1443 	return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1444 }
1445 
1446 /**
1447  * fdt_appendprop_cell - append a single cell value to a property
1448  *
1449  * This is an alternative name for fdt_appendprop_u32()
1450  */
1451 static inline int fdt_appendprop_cell(void *fdt, int nodeoffset,
1452 				      const char *name, uint32_t val)
1453 {
1454 	return fdt_appendprop_u32(fdt, nodeoffset, name, val);
1455 }
1456 
1457 /**
1458  * fdt_appendprop_string - append a string to a property
1459  * @fdt: pointer to the device tree blob
1460  * @nodeoffset: offset of the node whose property to change
1461  * @name: name of the property to change
1462  * @str: string value to append to the property
1463  *
1464  * fdt_appendprop_string() appends the given string to the value of
1465  * the named property in the given node, or creates a new property
1466  * with that value if it does not already exist.
1467  *
1468  * This function may insert data into the blob, and will therefore
1469  * change the offsets of some existing nodes.
1470  *
1471  * returns:
1472  *	0, on success
1473  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1474  *		contain the new property value
1475  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1476  *	-FDT_ERR_BADLAYOUT,
1477  *	-FDT_ERR_BADMAGIC,
1478  *	-FDT_ERR_BADVERSION,
1479  *	-FDT_ERR_BADSTATE,
1480  *	-FDT_ERR_BADSTRUCTURE,
1481  *	-FDT_ERR_BADLAYOUT,
1482  *	-FDT_ERR_TRUNCATED, standard meanings
1483  */
1484 #define fdt_appendprop_string(fdt, nodeoffset, name, str) \
1485 	fdt_appendprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1486 
1487 /**
1488  * fdt_delprop - delete a property
1489  * @fdt: pointer to the device tree blob
1490  * @nodeoffset: offset of the node whose property to nop
1491  * @name: name of the property to nop
1492  *
1493  * fdt_del_property() will delete the given property.
1494  *
1495  * This function will delete data from the blob, and will therefore
1496  * change the offsets of some existing nodes.
1497  *
1498  * returns:
1499  *	0, on success
1500  *	-FDT_ERR_NOTFOUND, node does not have the named property
1501  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1502  *	-FDT_ERR_BADLAYOUT,
1503  *	-FDT_ERR_BADMAGIC,
1504  *	-FDT_ERR_BADVERSION,
1505  *	-FDT_ERR_BADSTATE,
1506  *	-FDT_ERR_BADSTRUCTURE,
1507  *	-FDT_ERR_TRUNCATED, standard meanings
1508  */
1509 int fdt_delprop(void *fdt, int nodeoffset, const char *name);
1510 
1511 /**
1512  * fdt_add_subnode_namelen - creates a new node based on substring
1513  * @fdt: pointer to the device tree blob
1514  * @parentoffset: structure block offset of a node
1515  * @name: name of the subnode to locate
1516  * @namelen: number of characters of name to consider
1517  *
1518  * Identical to fdt_add_subnode(), but use only the first namelen
1519  * characters of name as the name of the new node.  This is useful for
1520  * creating subnodes based on a portion of a larger string, such as a
1521  * full path.
1522  */
1523 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
1524 			    const char *name, int namelen);
1525 
1526 /**
1527  * fdt_add_subnode - creates a new node
1528  * @fdt: pointer to the device tree blob
1529  * @parentoffset: structure block offset of a node
1530  * @name: name of the subnode to locate
1531  *
1532  * fdt_add_subnode() creates a new node as a subnode of the node at
1533  * structure block offset parentoffset, with the given name (which
1534  * should include the unit address, if any).
1535  *
1536  * This function will insert data into the blob, and will therefore
1537  * change the offsets of some existing nodes.
1538 
1539  * returns:
1540  *	structure block offset of the created nodeequested subnode (>=0), on success
1541  *	-FDT_ERR_NOTFOUND, if the requested subnode does not exist
1542  *	-FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag
1543  *	-FDT_ERR_EXISTS, if the node at parentoffset already has a subnode of
1544  *		the given name
1545  *	-FDT_ERR_NOSPACE, if there is insufficient free space in the
1546  *		blob to contain the new node
1547  *	-FDT_ERR_NOSPACE
1548  *	-FDT_ERR_BADLAYOUT
1549  *      -FDT_ERR_BADMAGIC,
1550  *	-FDT_ERR_BADVERSION,
1551  *	-FDT_ERR_BADSTATE,
1552  *	-FDT_ERR_BADSTRUCTURE,
1553  *	-FDT_ERR_TRUNCATED, standard meanings.
1554  */
1555 int fdt_add_subnode(void *fdt, int parentoffset, const char *name);
1556 
1557 /**
1558  * fdt_del_node - delete a node (subtree)
1559  * @fdt: pointer to the device tree blob
1560  * @nodeoffset: offset of the node to nop
1561  *
1562  * fdt_del_node() will remove the given node, including all its
1563  * subnodes if any, from the blob.
1564  *
1565  * This function will delete data from the blob, and will therefore
1566  * change the offsets of some existing nodes.
1567  *
1568  * returns:
1569  *	0, on success
1570  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1571  *	-FDT_ERR_BADLAYOUT,
1572  *	-FDT_ERR_BADMAGIC,
1573  *	-FDT_ERR_BADVERSION,
1574  *	-FDT_ERR_BADSTATE,
1575  *	-FDT_ERR_BADSTRUCTURE,
1576  *	-FDT_ERR_TRUNCATED, standard meanings
1577  */
1578 int fdt_del_node(void *fdt, int nodeoffset);
1579 
1580 /**********************************************************************/
1581 /* Debugging / informational functions                                */
1582 /**********************************************************************/
1583 
1584 const char *fdt_strerror(int errval);
1585 
1586 #endif /* _LIBFDT_H */
1587