xref: /optee_os/core/lib/libfdt/include/libfdt.h (revision a50cb361d9e5735f197ccc87beb0d24af8315369)
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 - 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  *
330  * fdt_path_offset() finds a node of a given path in the device tree.
331  * Each path component may omit the unit address portion, but the
332  * results of this are undefined if any such path component is
333  * ambiguous (that is if there are multiple nodes at the relevant
334  * level matching the given component, differentiated only by unit
335  * address).
336  *
337  * returns:
338  *	structure block offset of the node with the requested path (>=0), on success
339  *	-FDT_ERR_BADPATH, given path does not begin with '/' or is invalid
340  *	-FDT_ERR_NOTFOUND, if the requested node does not exist
341  *      -FDT_ERR_BADMAGIC,
342  *	-FDT_ERR_BADVERSION,
343  *	-FDT_ERR_BADSTATE,
344  *	-FDT_ERR_BADSTRUCTURE,
345  *	-FDT_ERR_TRUNCATED, standard meanings.
346  */
347 int fdt_path_offset(const void *fdt, const char *path);
348 
349 /**
350  * fdt_get_name - retrieve the name of a given node
351  * @fdt: pointer to the device tree blob
352  * @nodeoffset: structure block offset of the starting node
353  * @lenp: pointer to an integer variable (will be overwritten) or NULL
354  *
355  * fdt_get_name() retrieves the name (including unit address) of the
356  * device tree node at structure block offset nodeoffset.  If lenp is
357  * non-NULL, the length of this name is also returned, in the integer
358  * pointed to by lenp.
359  *
360  * returns:
361  *	pointer to the node's name, on success
362  *		If lenp is non-NULL, *lenp contains the length of that name (>=0)
363  *	NULL, on error
364  *		if lenp is non-NULL *lenp contains an error code (<0):
365  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
366  *		-FDT_ERR_BADMAGIC,
367  *		-FDT_ERR_BADVERSION,
368  *		-FDT_ERR_BADSTATE, standard meanings
369  */
370 const char *fdt_get_name(const void *fdt, int nodeoffset, int *lenp);
371 
372 /**
373  * fdt_first_property_offset - find the offset of a node's first property
374  * @fdt: pointer to the device tree blob
375  * @nodeoffset: structure block offset of a node
376  *
377  * fdt_first_property_offset() finds the first property of the node at
378  * the given structure block offset.
379  *
380  * returns:
381  *	structure block offset of the property (>=0), on success
382  *	-FDT_ERR_NOTFOUND, if the requested node has no properties
383  *	-FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_BEGIN_NODE tag
384  *      -FDT_ERR_BADMAGIC,
385  *	-FDT_ERR_BADVERSION,
386  *	-FDT_ERR_BADSTATE,
387  *	-FDT_ERR_BADSTRUCTURE,
388  *	-FDT_ERR_TRUNCATED, standard meanings.
389  */
390 int fdt_first_property_offset(const void *fdt, int nodeoffset);
391 
392 /**
393  * fdt_next_property_offset - step through a node's properties
394  * @fdt: pointer to the device tree blob
395  * @offset: structure block offset of a property
396  *
397  * fdt_next_property_offset() finds the property immediately after the
398  * one at the given structure block offset.  This will be a property
399  * of the same node as the given property.
400  *
401  * returns:
402  *	structure block offset of the next property (>=0), on success
403  *	-FDT_ERR_NOTFOUND, if the given property is the last in its node
404  *	-FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_PROP tag
405  *      -FDT_ERR_BADMAGIC,
406  *	-FDT_ERR_BADVERSION,
407  *	-FDT_ERR_BADSTATE,
408  *	-FDT_ERR_BADSTRUCTURE,
409  *	-FDT_ERR_TRUNCATED, standard meanings.
410  */
411 int fdt_next_property_offset(const void *fdt, int offset);
412 
413 /**
414  * fdt_get_property_by_offset - retrieve the property at a given offset
415  * @fdt: pointer to the device tree blob
416  * @offset: offset of the property to retrieve
417  * @lenp: pointer to an integer variable (will be overwritten) or NULL
418  *
419  * fdt_get_property_by_offset() retrieves a pointer to the
420  * fdt_property structure within the device tree blob at the given
421  * offset.  If lenp is non-NULL, the length of the property value is
422  * also returned, in the integer pointed to by lenp.
423  *
424  * returns:
425  *	pointer to the structure representing the property
426  *		if lenp is non-NULL, *lenp contains the length of the property
427  *		value (>=0)
428  *	NULL, on error
429  *		if lenp is non-NULL, *lenp contains an error code (<0):
430  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
431  *		-FDT_ERR_BADMAGIC,
432  *		-FDT_ERR_BADVERSION,
433  *		-FDT_ERR_BADSTATE,
434  *		-FDT_ERR_BADSTRUCTURE,
435  *		-FDT_ERR_TRUNCATED, standard meanings
436  */
437 const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
438 						      int offset,
439 						      int *lenp);
440 
441 /**
442  * fdt_get_property_namelen - find a property based on substring
443  * @fdt: pointer to the device tree blob
444  * @nodeoffset: offset of the node whose property to find
445  * @name: name of the property to find
446  * @namelen: number of characters of name to consider
447  * @lenp: pointer to an integer variable (will be overwritten) or NULL
448  *
449  * Identical to fdt_get_property_namelen(), but only examine the first
450  * namelen characters of name for matching the property name.
451  */
452 const struct fdt_property *fdt_get_property_namelen(const void *fdt,
453 						    int nodeoffset,
454 						    const char *name,
455 						    int namelen, int *lenp);
456 
457 /**
458  * fdt_get_property - find a given property in a given node
459  * @fdt: pointer to the device tree blob
460  * @nodeoffset: offset of the node whose property to find
461  * @name: name of the property to find
462  * @lenp: pointer to an integer variable (will be overwritten) or NULL
463  *
464  * fdt_get_property() retrieves a pointer to the fdt_property
465  * structure within the device tree blob corresponding to the property
466  * named 'name' of the node at offset nodeoffset.  If lenp is
467  * non-NULL, the length of the property value is also returned, in the
468  * integer pointed to by lenp.
469  *
470  * returns:
471  *	pointer to the structure representing the property
472  *		if lenp is non-NULL, *lenp contains the length of the property
473  *		value (>=0)
474  *	NULL, on error
475  *		if lenp is non-NULL, *lenp contains an error code (<0):
476  *		-FDT_ERR_NOTFOUND, node does not have named property
477  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
478  *		-FDT_ERR_BADMAGIC,
479  *		-FDT_ERR_BADVERSION,
480  *		-FDT_ERR_BADSTATE,
481  *		-FDT_ERR_BADSTRUCTURE,
482  *		-FDT_ERR_TRUNCATED, standard meanings
483  */
484 const struct fdt_property *fdt_get_property(const void *fdt, int nodeoffset,
485 					    const char *name, int *lenp);
486 static inline struct fdt_property *fdt_get_property_w(void *fdt, int nodeoffset,
487 						      const char *name,
488 						      int *lenp)
489 {
490 	return (struct fdt_property *)(uintptr_t)
491 		fdt_get_property(fdt, nodeoffset, name, lenp);
492 }
493 
494 /**
495  * fdt_getprop_by_offset - retrieve the value of a property at a given offset
496  * @fdt: pointer to the device tree blob
497  * @ffset: offset of the property to read
498  * @namep: pointer to a string variable (will be overwritten) or NULL
499  * @lenp: pointer to an integer variable (will be overwritten) or NULL
500  *
501  * fdt_getprop_by_offset() retrieves a pointer to the value of the
502  * property at structure block offset 'offset' (this will be a pointer
503  * to within the device blob itself, not a copy of the value).  If
504  * lenp is non-NULL, the length of the property value is also
505  * returned, in the integer pointed to by lenp.  If namep is non-NULL,
506  * the property's namne will also be returned in the char * pointed to
507  * by namep (this will be a pointer to within the device tree's string
508  * block, not a new copy of the name).
509  *
510  * returns:
511  *	pointer to the property's value
512  *		if lenp is non-NULL, *lenp contains the length of the property
513  *		value (>=0)
514  *		if namep is non-NULL *namep contiains a pointer to the property
515  *		name.
516  *	NULL, on error
517  *		if lenp is non-NULL, *lenp contains an error code (<0):
518  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
519  *		-FDT_ERR_BADMAGIC,
520  *		-FDT_ERR_BADVERSION,
521  *		-FDT_ERR_BADSTATE,
522  *		-FDT_ERR_BADSTRUCTURE,
523  *		-FDT_ERR_TRUNCATED, standard meanings
524  */
525 const void *fdt_getprop_by_offset(const void *fdt, int offset,
526 				  const char **namep, int *lenp);
527 
528 /**
529  * fdt_getprop_namelen - get property value based on substring
530  * @fdt: pointer to the device tree blob
531  * @nodeoffset: offset of the node whose property to find
532  * @name: name of the property to find
533  * @namelen: number of characters of name to consider
534  * @lenp: pointer to an integer variable (will be overwritten) or NULL
535  *
536  * Identical to fdt_getprop(), but only examine the first namelen
537  * characters of name for matching the property name.
538  */
539 const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
540 				const char *name, int namelen, int *lenp);
541 
542 /**
543  * fdt_getprop - retrieve the value of a given property
544  * @fdt: pointer to the device tree blob
545  * @nodeoffset: offset of the node whose property to find
546  * @name: name of the property to find
547  * @lenp: pointer to an integer variable (will be overwritten) or NULL
548  *
549  * fdt_getprop() retrieves a pointer to the value of the property
550  * named 'name' of the node at offset nodeoffset (this will be a
551  * pointer to within the device blob itself, not a copy of the value).
552  * If lenp is non-NULL, the length of the property value is also
553  * returned, in the integer pointed to by lenp.
554  *
555  * returns:
556  *	pointer to the property's value
557  *		if lenp is non-NULL, *lenp contains the length of the property
558  *		value (>=0)
559  *	NULL, on error
560  *		if lenp is non-NULL, *lenp contains an error code (<0):
561  *		-FDT_ERR_NOTFOUND, node does not have named property
562  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
563  *		-FDT_ERR_BADMAGIC,
564  *		-FDT_ERR_BADVERSION,
565  *		-FDT_ERR_BADSTATE,
566  *		-FDT_ERR_BADSTRUCTURE,
567  *		-FDT_ERR_TRUNCATED, standard meanings
568  */
569 const void *fdt_getprop(const void *fdt, int nodeoffset,
570 			const char *name, int *lenp);
571 static inline void *fdt_getprop_w(void *fdt, int nodeoffset,
572 				  const char *name, int *lenp)
573 {
574 	return (void *)(uintptr_t)fdt_getprop(fdt, nodeoffset, name, lenp);
575 }
576 
577 /**
578  * fdt_get_phandle - retrieve the phandle of a given node
579  * @fdt: pointer to the device tree blob
580  * @nodeoffset: structure block offset of the node
581  *
582  * fdt_get_phandle() retrieves the phandle of the device tree node at
583  * structure block offset nodeoffset.
584  *
585  * returns:
586  *	the phandle of the node at nodeoffset, on success (!= 0, != -1)
587  *	0, if the node has no phandle, or another error occurs
588  */
589 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset);
590 
591 /**
592  * fdt_get_alias_namelen - get alias based on substring
593  * @fdt: pointer to the device tree blob
594  * @name: name of the alias th look up
595  * @namelen: number of characters of name to consider
596  *
597  * Identical to fdt_get_alias(), but only examine the first namelen
598  * characters of name for matching the alias name.
599  */
600 const char *fdt_get_alias_namelen(const void *fdt,
601 				  const char *name, int namelen);
602 
603 /**
604  * fdt_get_alias - retreive the path referenced by a given alias
605  * @fdt: pointer to the device tree blob
606  * @name: name of the alias th look up
607  *
608  * fdt_get_alias() retrieves the value of a given alias.  That is, the
609  * value of the property named 'name' in the node /aliases.
610  *
611  * returns:
612  *	a pointer to the expansion of the alias named 'name', if it exists
613  *	NULL, if the given alias or the /aliases node does not exist
614  */
615 const char *fdt_get_alias(const void *fdt, const char *name);
616 
617 /**
618  * fdt_get_path - determine the full path of a node
619  * @fdt: pointer to the device tree blob
620  * @nodeoffset: offset of the node whose path to find
621  * @buf: character buffer to contain the returned path (will be overwritten)
622  * @buflen: size of the character buffer at buf
623  *
624  * fdt_get_path() computes the full path of the node at offset
625  * nodeoffset, and records that path in the buffer at buf.
626  *
627  * NOTE: This function is expensive, as it must scan the device tree
628  * structure from the start to nodeoffset.
629  *
630  * returns:
631  *	0, on success
632  *		buf contains the absolute path of the node at
633  *		nodeoffset, as a NUL-terminated string.
634  * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
635  *	-FDT_ERR_NOSPACE, the path of the given node is longer than (bufsize-1)
636  *		characters and will not fit in the given buffer.
637  *	-FDT_ERR_BADMAGIC,
638  *	-FDT_ERR_BADVERSION,
639  *	-FDT_ERR_BADSTATE,
640  *	-FDT_ERR_BADSTRUCTURE, standard meanings
641  */
642 int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen);
643 
644 /**
645  * fdt_supernode_atdepth_offset - find a specific ancestor of a node
646  * @fdt: pointer to the device tree blob
647  * @nodeoffset: offset of the node whose parent to find
648  * @supernodedepth: depth of the ancestor to find
649  * @nodedepth: pointer to an integer variable (will be overwritten) or NULL
650  *
651  * fdt_supernode_atdepth_offset() finds an ancestor of the given node
652  * at a specific depth from the root (where the root itself has depth
653  * 0, its immediate subnodes depth 1 and so forth).  So
654  *	fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, NULL);
655  * will always return 0, the offset of the root node.  If the node at
656  * nodeoffset has depth D, then:
657  *	fdt_supernode_atdepth_offset(fdt, nodeoffset, D, NULL);
658  * will return nodeoffset itself.
659  *
660  * NOTE: This function is expensive, as it must scan the device tree
661  * structure from the start to nodeoffset.
662  *
663  * returns:
664 
665  *	structure block offset of the node at node offset's ancestor
666  *		of depth supernodedepth (>=0), on success
667  * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
668 *	-FDT_ERR_NOTFOUND, supernodedepth was greater than the depth of nodeoffset
669  *	-FDT_ERR_BADMAGIC,
670  *	-FDT_ERR_BADVERSION,
671  *	-FDT_ERR_BADSTATE,
672  *	-FDT_ERR_BADSTRUCTURE, standard meanings
673  */
674 int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
675 				 int supernodedepth, int *nodedepth);
676 
677 /**
678  * fdt_node_depth - find the depth of a given node
679  * @fdt: pointer to the device tree blob
680  * @nodeoffset: offset of the node whose parent to find
681  *
682  * fdt_node_depth() finds the depth of a given node.  The root node
683  * has depth 0, its immediate subnodes depth 1 and so forth.
684  *
685  * NOTE: This function is expensive, as it must scan the device tree
686  * structure from the start to nodeoffset.
687  *
688  * returns:
689  *	depth of the node at nodeoffset (>=0), on success
690  * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
691  *	-FDT_ERR_BADMAGIC,
692  *	-FDT_ERR_BADVERSION,
693  *	-FDT_ERR_BADSTATE,
694  *	-FDT_ERR_BADSTRUCTURE, standard meanings
695  */
696 int fdt_node_depth(const void *fdt, int nodeoffset);
697 
698 /**
699  * fdt_parent_offset - find the parent of a given node
700  * @fdt: pointer to the device tree blob
701  * @nodeoffset: offset of the node whose parent to find
702  *
703  * fdt_parent_offset() locates the parent node of a given node (that
704  * is, it finds the offset of the node which contains the node at
705  * nodeoffset as a subnode).
706  *
707  * NOTE: This function is expensive, as it must scan the device tree
708  * structure from the start to nodeoffset, *twice*.
709  *
710  * returns:
711  *	structure block offset of the parent of the node at nodeoffset
712  *		(>=0), on success
713  * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
714  *	-FDT_ERR_BADMAGIC,
715  *	-FDT_ERR_BADVERSION,
716  *	-FDT_ERR_BADSTATE,
717  *	-FDT_ERR_BADSTRUCTURE, standard meanings
718  */
719 int fdt_parent_offset(const void *fdt, int nodeoffset);
720 
721 /**
722  * fdt_node_offset_by_prop_value - find nodes with a given property value
723  * @fdt: pointer to the device tree blob
724  * @startoffset: only find nodes after this offset
725  * @propname: property name to check
726  * @propval: property value to search for
727  * @proplen: length of the value in propval
728  *
729  * fdt_node_offset_by_prop_value() returns the offset of the first
730  * node after startoffset, which has a property named propname whose
731  * value is of length proplen and has value equal to propval; or if
732  * startoffset is -1, the very first such node in the tree.
733  *
734  * To iterate through all nodes matching the criterion, the following
735  * idiom can be used:
736  *	offset = fdt_node_offset_by_prop_value(fdt, -1, propname,
737  *					       propval, proplen);
738  *	while (offset != -FDT_ERR_NOTFOUND) {
739  *		// other code here
740  *		offset = fdt_node_offset_by_prop_value(fdt, offset, propname,
741  *						       propval, proplen);
742  *	}
743  *
744  * Note the -1 in the first call to the function, if 0 is used here
745  * instead, the function will never locate the root node, even if it
746  * matches the criterion.
747  *
748  * returns:
749  *	structure block offset of the located node (>= 0, >startoffset),
750  *		 on success
751  *	-FDT_ERR_NOTFOUND, no node matching the criterion exists in the
752  *		tree after startoffset
753  * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
754  *	-FDT_ERR_BADMAGIC,
755  *	-FDT_ERR_BADVERSION,
756  *	-FDT_ERR_BADSTATE,
757  *	-FDT_ERR_BADSTRUCTURE, standard meanings
758  */
759 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
760 				  const char *propname,
761 				  const void *propval, int proplen);
762 
763 /**
764  * fdt_node_offset_by_phandle - find the node with a given phandle
765  * @fdt: pointer to the device tree blob
766  * @phandle: phandle value
767  *
768  * fdt_node_offset_by_phandle() returns the offset of the node
769  * which has the given phandle value.  If there is more than one node
770  * in the tree with the given phandle (an invalid tree), results are
771  * undefined.
772  *
773  * returns:
774  *	structure block offset of the located node (>= 0), on success
775  *	-FDT_ERR_NOTFOUND, no node with that phandle exists
776  *	-FDT_ERR_BADPHANDLE, given phandle value was invalid (0 or -1)
777  *	-FDT_ERR_BADMAGIC,
778  *	-FDT_ERR_BADVERSION,
779  *	-FDT_ERR_BADSTATE,
780  *	-FDT_ERR_BADSTRUCTURE, standard meanings
781  */
782 int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle);
783 
784 /**
785  * fdt_node_check_compatible: check a node's compatible property
786  * @fdt: pointer to the device tree blob
787  * @nodeoffset: offset of a tree node
788  * @compatible: string to match against
789  *
790  *
791  * fdt_node_check_compatible() returns 0 if the given node contains a
792  * 'compatible' property with the given string as one of its elements,
793  * it returns non-zero otherwise, or on error.
794  *
795  * returns:
796  *	0, if the node has a 'compatible' property listing the given string
797  *	1, if the node has a 'compatible' property, but it does not list
798  *		the given string
799  *	-FDT_ERR_NOTFOUND, if the given node has no 'compatible' property
800  * 	-FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag
801  *	-FDT_ERR_BADMAGIC,
802  *	-FDT_ERR_BADVERSION,
803  *	-FDT_ERR_BADSTATE,
804  *	-FDT_ERR_BADSTRUCTURE, standard meanings
805  */
806 int fdt_node_check_compatible(const void *fdt, int nodeoffset,
807 			      const char *compatible);
808 
809 /**
810  * fdt_node_offset_by_compatible - find nodes with a given 'compatible' value
811  * @fdt: pointer to the device tree blob
812  * @startoffset: only find nodes after this offset
813  * @compatible: 'compatible' string to match against
814  *
815  * fdt_node_offset_by_compatible() returns the offset of the first
816  * node after startoffset, which has a 'compatible' property which
817  * lists the given compatible string; or if startoffset is -1, the
818  * very first such node in the tree.
819  *
820  * To iterate through all nodes matching the criterion, the following
821  * idiom can be used:
822  *	offset = fdt_node_offset_by_compatible(fdt, -1, compatible);
823  *	while (offset != -FDT_ERR_NOTFOUND) {
824  *		// other code here
825  *		offset = fdt_node_offset_by_compatible(fdt, offset, compatible);
826  *	}
827  *
828  * Note the -1 in the first call to the function, if 0 is used here
829  * instead, the function will never locate the root node, even if it
830  * matches the criterion.
831  *
832  * returns:
833  *	structure block offset of the located node (>= 0, >startoffset),
834  *		 on success
835  *	-FDT_ERR_NOTFOUND, no node matching the criterion exists in the
836  *		tree after startoffset
837  * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
838  *	-FDT_ERR_BADMAGIC,
839  *	-FDT_ERR_BADVERSION,
840  *	-FDT_ERR_BADSTATE,
841  *	-FDT_ERR_BADSTRUCTURE, standard meanings
842  */
843 int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
844 				  const char *compatible);
845 
846 /**
847  * fdt_stringlist_contains - check a string list property for a string
848  * @strlist: Property containing a list of strings to check
849  * @listlen: Length of property
850  * @str: String to search for
851  *
852  * This is a utility function provided for convenience. The list contains
853  * one or more strings, each terminated by \0, as is found in a device tree
854  * "compatible" property.
855  *
856  * @return: 1 if the string is found in the list, 0 not found, or invalid list
857  */
858 int fdt_stringlist_contains(const char *strlist, int listlen, const char *str);
859 
860 /**********************************************************************/
861 /* Read-only functions (addressing related)                           */
862 /**********************************************************************/
863 
864 /**
865  * FDT_MAX_NCELLS - maximum value for #address-cells and #size-cells
866  *
867  * This is the maximum value for #address-cells, #size-cells and
868  * similar properties that will be processed by libfdt.  IEE1275
869  * requires that OF implementations handle values up to 4.
870  * Implementations may support larger values, but in practice higher
871  * values aren't used.
872  */
873 #define FDT_MAX_NCELLS		4
874 
875 /**
876  * fdt_address_cells - retrieve address size for a bus represented in the tree
877  * @fdt: pointer to the device tree blob
878  * @nodeoffset: offset of the node to find the address size for
879  *
880  * When the node has a valid #address-cells property, returns its value.
881  *
882  * returns:
883  *	0 <= n < FDT_MAX_NCELLS, on success
884  *      2, if the node has no #address-cells property
885  *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid #address-cells property
886  *	-FDT_ERR_BADMAGIC,
887  *	-FDT_ERR_BADVERSION,
888  *	-FDT_ERR_BADSTATE,
889  *	-FDT_ERR_BADSTRUCTURE,
890  *	-FDT_ERR_TRUNCATED, standard meanings
891  */
892 int fdt_address_cells(const void *fdt, int nodeoffset);
893 
894 /**
895  * fdt_size_cells - retrieve address range size for a bus represented in the
896  *                  tree
897  * @fdt: pointer to the device tree blob
898  * @nodeoffset: offset of the node to find the address range size for
899  *
900  * When the node has a valid #size-cells property, returns its value.
901  *
902  * returns:
903  *	0 <= n < FDT_MAX_NCELLS, on success
904  *      2, if the node has no #address-cells property
905  *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid #size-cells property
906  *	-FDT_ERR_BADMAGIC,
907  *	-FDT_ERR_BADVERSION,
908  *	-FDT_ERR_BADSTATE,
909  *	-FDT_ERR_BADSTRUCTURE,
910  *	-FDT_ERR_TRUNCATED, standard meanings
911  */
912 int fdt_size_cells(const void *fdt, int nodeoffset);
913 
914 
915 /**********************************************************************/
916 /* Write-in-place functions                                           */
917 /**********************************************************************/
918 
919 /**
920  * fdt_setprop_inplace - change a property's value, but not its size
921  * @fdt: pointer to the device tree blob
922  * @nodeoffset: offset of the node whose property to change
923  * @name: name of the property to change
924  * @val: pointer to data to replace the property value with
925  * @len: length of the property value
926  *
927  * fdt_setprop_inplace() replaces the value of a given property with
928  * the data in val, of length len.  This function cannot change the
929  * size of a property, and so will only work if len is equal to the
930  * current length of the property.
931  *
932  * This function will alter only the bytes in the blob which contain
933  * the given property value, and will not alter or move any other part
934  * of the tree.
935  *
936  * returns:
937  *	0, on success
938  *	-FDT_ERR_NOSPACE, if len is not equal to the property's current length
939  *	-FDT_ERR_NOTFOUND, node does not have the named property
940  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
941  *	-FDT_ERR_BADMAGIC,
942  *	-FDT_ERR_BADVERSION,
943  *	-FDT_ERR_BADSTATE,
944  *	-FDT_ERR_BADSTRUCTURE,
945  *	-FDT_ERR_TRUNCATED, standard meanings
946  */
947 int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
948 			const void *val, int len);
949 
950 /**
951  * fdt_setprop_inplace_u32 - change the value of a 32-bit integer property
952  * @fdt: pointer to the device tree blob
953  * @nodeoffset: offset of the node whose property to change
954  * @name: name of the property to change
955  * @val: 32-bit integer value to replace the property with
956  *
957  * fdt_setprop_inplace_u32() replaces the value of a given property
958  * with the 32-bit integer value in val, converting val to big-endian
959  * if necessary.  This function cannot change the size of a property,
960  * and so will only work if the property already exists and has length
961  * 4.
962  *
963  * This function will alter only the bytes in the blob which contain
964  * the given property value, and will not alter or move any other part
965  * of the tree.
966  *
967  * returns:
968  *	0, on success
969  *	-FDT_ERR_NOSPACE, if the property's length is not equal to 4
970  *	-FDT_ERR_NOTFOUND, node does not have the named property
971  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
972  *	-FDT_ERR_BADMAGIC,
973  *	-FDT_ERR_BADVERSION,
974  *	-FDT_ERR_BADSTATE,
975  *	-FDT_ERR_BADSTRUCTURE,
976  *	-FDT_ERR_TRUNCATED, standard meanings
977  */
978 static inline int fdt_setprop_inplace_u32(void *fdt, int nodeoffset,
979 					  const char *name, uint32_t val)
980 {
981 	fdt32_t tmp = cpu_to_fdt32(val);
982 	return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
983 }
984 
985 /**
986  * fdt_setprop_inplace_u64 - change the value of a 64-bit integer property
987  * @fdt: pointer to the device tree blob
988  * @nodeoffset: offset of the node whose property to change
989  * @name: name of the property to change
990  * @val: 64-bit integer value to replace the property with
991  *
992  * fdt_setprop_inplace_u64() replaces the value of a given property
993  * with the 64-bit integer value in val, converting val to big-endian
994  * if necessary.  This function cannot change the size of a property,
995  * and so will only work if the property already exists and has length
996  * 8.
997  *
998  * This function will alter only the bytes in the blob which contain
999  * the given property value, and will not alter or move any other part
1000  * of the tree.
1001  *
1002  * returns:
1003  *	0, on success
1004  *	-FDT_ERR_NOSPACE, if the property's length is not equal to 8
1005  *	-FDT_ERR_NOTFOUND, node does not have the named property
1006  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1007  *	-FDT_ERR_BADMAGIC,
1008  *	-FDT_ERR_BADVERSION,
1009  *	-FDT_ERR_BADSTATE,
1010  *	-FDT_ERR_BADSTRUCTURE,
1011  *	-FDT_ERR_TRUNCATED, standard meanings
1012  */
1013 static inline int fdt_setprop_inplace_u64(void *fdt, int nodeoffset,
1014 					  const char *name, uint64_t val)
1015 {
1016 	fdt64_t tmp = cpu_to_fdt64(val);
1017 	return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1018 }
1019 
1020 /**
1021  * fdt_setprop_inplace_cell - change the value of a single-cell property
1022  *
1023  * This is an alternative name for fdt_setprop_inplace_u32()
1024  */
1025 static inline int fdt_setprop_inplace_cell(void *fdt, int nodeoffset,
1026 					   const char *name, uint32_t val)
1027 {
1028 	return fdt_setprop_inplace_u32(fdt, nodeoffset, name, val);
1029 }
1030 
1031 /**
1032  * fdt_nop_property - replace a property with nop tags
1033  * @fdt: pointer to the device tree blob
1034  * @nodeoffset: offset of the node whose property to nop
1035  * @name: name of the property to nop
1036  *
1037  * fdt_nop_property() will replace a given property's representation
1038  * in the blob with FDT_NOP tags, effectively removing it from the
1039  * tree.
1040  *
1041  * This function will alter only the bytes in the blob which contain
1042  * the property, and will not alter or move any other part of the
1043  * tree.
1044  *
1045  * returns:
1046  *	0, on success
1047  *	-FDT_ERR_NOTFOUND, node does not have the named property
1048  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1049  *	-FDT_ERR_BADMAGIC,
1050  *	-FDT_ERR_BADVERSION,
1051  *	-FDT_ERR_BADSTATE,
1052  *	-FDT_ERR_BADSTRUCTURE,
1053  *	-FDT_ERR_TRUNCATED, standard meanings
1054  */
1055 int fdt_nop_property(void *fdt, int nodeoffset, const char *name);
1056 
1057 /**
1058  * fdt_nop_node - replace a node (subtree) with nop tags
1059  * @fdt: pointer to the device tree blob
1060  * @nodeoffset: offset of the node to nop
1061  *
1062  * fdt_nop_node() will replace a given node's representation in the
1063  * blob, including all its subnodes, if any, with FDT_NOP tags,
1064  * effectively removing it from the tree.
1065  *
1066  * This function will alter only the bytes in the blob which contain
1067  * the node and its properties and subnodes, and will not alter or
1068  * move any other part of the tree.
1069  *
1070  * returns:
1071  *	0, on success
1072  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1073  *	-FDT_ERR_BADMAGIC,
1074  *	-FDT_ERR_BADVERSION,
1075  *	-FDT_ERR_BADSTATE,
1076  *	-FDT_ERR_BADSTRUCTURE,
1077  *	-FDT_ERR_TRUNCATED, standard meanings
1078  */
1079 int fdt_nop_node(void *fdt, int nodeoffset);
1080 
1081 /**********************************************************************/
1082 /* Sequential write functions                                         */
1083 /**********************************************************************/
1084 
1085 int fdt_create(void *buf, int bufsize);
1086 int fdt_resize(void *fdt, void *buf, int bufsize);
1087 int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size);
1088 int fdt_finish_reservemap(void *fdt);
1089 int fdt_begin_node(void *fdt, const char *name);
1090 int fdt_property(void *fdt, const char *name, const void *val, int len);
1091 static inline int fdt_property_u32(void *fdt, const char *name, uint32_t val)
1092 {
1093 	fdt32_t tmp = cpu_to_fdt32(val);
1094 	return fdt_property(fdt, name, &tmp, sizeof(tmp));
1095 }
1096 static inline int fdt_property_u64(void *fdt, const char *name, uint64_t val)
1097 {
1098 	fdt64_t tmp = cpu_to_fdt64(val);
1099 	return fdt_property(fdt, name, &tmp, sizeof(tmp));
1100 }
1101 static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val)
1102 {
1103 	return fdt_property_u32(fdt, name, val);
1104 }
1105 #define fdt_property_string(fdt, name, str) \
1106 	fdt_property(fdt, name, str, strlen(str)+1)
1107 int fdt_end_node(void *fdt);
1108 int fdt_finish(void *fdt);
1109 
1110 /**********************************************************************/
1111 /* Read-write functions                                               */
1112 /**********************************************************************/
1113 
1114 int fdt_create_empty_tree(void *buf, int bufsize);
1115 int fdt_open_into(const void *fdt, void *buf, int bufsize);
1116 int fdt_pack(void *fdt);
1117 
1118 /**
1119  * fdt_add_mem_rsv - add one memory reserve map entry
1120  * @fdt: pointer to the device tree blob
1121  * @address, @size: 64-bit values (native endian)
1122  *
1123  * Adds a reserve map entry to the given blob reserving a region at
1124  * address address of length size.
1125  *
1126  * This function will insert data into the reserve map and will
1127  * therefore change the indexes of some entries in the table.
1128  *
1129  * returns:
1130  *	0, on success
1131  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1132  *		contain the new reservation entry
1133  *	-FDT_ERR_BADMAGIC,
1134  *	-FDT_ERR_BADVERSION,
1135  *	-FDT_ERR_BADSTATE,
1136  *	-FDT_ERR_BADSTRUCTURE,
1137  *	-FDT_ERR_BADLAYOUT,
1138  *	-FDT_ERR_TRUNCATED, standard meanings
1139  */
1140 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size);
1141 
1142 /**
1143  * fdt_del_mem_rsv - remove a memory reserve map entry
1144  * @fdt: pointer to the device tree blob
1145  * @n: entry to remove
1146  *
1147  * fdt_del_mem_rsv() removes the n-th memory reserve map entry from
1148  * the blob.
1149  *
1150  * This function will delete data from the reservation table and will
1151  * therefore change the indexes of some entries in the table.
1152  *
1153  * returns:
1154  *	0, on success
1155  *	-FDT_ERR_NOTFOUND, there is no entry of the given index (i.e. there
1156  *		are less than n+1 reserve map entries)
1157  *	-FDT_ERR_BADMAGIC,
1158  *	-FDT_ERR_BADVERSION,
1159  *	-FDT_ERR_BADSTATE,
1160  *	-FDT_ERR_BADSTRUCTURE,
1161  *	-FDT_ERR_BADLAYOUT,
1162  *	-FDT_ERR_TRUNCATED, standard meanings
1163  */
1164 int fdt_del_mem_rsv(void *fdt, int n);
1165 
1166 /**
1167  * fdt_set_name - change the name of a given node
1168  * @fdt: pointer to the device tree blob
1169  * @nodeoffset: structure block offset of a node
1170  * @name: name to give the node
1171  *
1172  * fdt_set_name() replaces the name (including unit address, if any)
1173  * of the given node with the given string.  NOTE: this function can't
1174  * efficiently check if the new name is unique amongst the given
1175  * node's siblings; results are undefined if this function is invoked
1176  * with a name equal to one of the given node's siblings.
1177  *
1178  * This function may insert or delete data from the blob, and will
1179  * therefore change the offsets of some existing nodes.
1180  *
1181  * returns:
1182  *	0, on success
1183  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob
1184  *		to contain the new name
1185  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1186  *	-FDT_ERR_BADMAGIC,
1187  *	-FDT_ERR_BADVERSION,
1188  *	-FDT_ERR_BADSTATE, standard meanings
1189  */
1190 int fdt_set_name(void *fdt, int nodeoffset, const char *name);
1191 
1192 /**
1193  * fdt_setprop - create or change a property
1194  * @fdt: pointer to the device tree blob
1195  * @nodeoffset: offset of the node whose property to change
1196  * @name: name of the property to change
1197  * @val: pointer to data to set the property value to
1198  * @len: length of the property value
1199  *
1200  * fdt_setprop() sets the value of the named property in the given
1201  * node to the given value and length, creating the property if it
1202  * does not already exist.
1203  *
1204  * This function may insert or delete data from the blob, and will
1205  * therefore change the offsets of some existing nodes.
1206  *
1207  * returns:
1208  *	0, on success
1209  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1210  *		contain the new property value
1211  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1212  *	-FDT_ERR_BADLAYOUT,
1213  *	-FDT_ERR_BADMAGIC,
1214  *	-FDT_ERR_BADVERSION,
1215  *	-FDT_ERR_BADSTATE,
1216  *	-FDT_ERR_BADSTRUCTURE,
1217  *	-FDT_ERR_BADLAYOUT,
1218  *	-FDT_ERR_TRUNCATED, standard meanings
1219  */
1220 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
1221 		const void *val, int len);
1222 
1223 /**
1224  * fdt_setprop_u32 - set a property to a 32-bit integer
1225  * @fdt: pointer to the device tree blob
1226  * @nodeoffset: offset of the node whose property to change
1227  * @name: name of the property to change
1228  * @val: 32-bit integer value for the property (native endian)
1229  *
1230  * fdt_setprop_u32() sets the value of the named property in the given
1231  * node to the given 32-bit integer value (converting to big-endian if
1232  * necessary), or creates a new property with that value if it does
1233  * not already exist.
1234  *
1235  * This function may insert or delete data from the blob, and will
1236  * therefore change the offsets of some existing nodes.
1237  *
1238  * returns:
1239  *	0, on success
1240  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1241  *		contain the new property value
1242  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1243  *	-FDT_ERR_BADLAYOUT,
1244  *	-FDT_ERR_BADMAGIC,
1245  *	-FDT_ERR_BADVERSION,
1246  *	-FDT_ERR_BADSTATE,
1247  *	-FDT_ERR_BADSTRUCTURE,
1248  *	-FDT_ERR_BADLAYOUT,
1249  *	-FDT_ERR_TRUNCATED, standard meanings
1250  */
1251 static inline int fdt_setprop_u32(void *fdt, int nodeoffset, const char *name,
1252 				  uint32_t val)
1253 {
1254 	fdt32_t tmp = cpu_to_fdt32(val);
1255 	return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1256 }
1257 
1258 /**
1259  * fdt_setprop_u64 - set a property to a 64-bit integer
1260  * @fdt: pointer to the device tree blob
1261  * @nodeoffset: offset of the node whose property to change
1262  * @name: name of the property to change
1263  * @val: 64-bit integer value for the property (native endian)
1264  *
1265  * fdt_setprop_u64() sets the value of the named property in the given
1266  * node to the given 64-bit integer value (converting to big-endian if
1267  * necessary), or creates a new property with that value if it does
1268  * not already exist.
1269  *
1270  * This function may insert or delete data from the blob, and will
1271  * therefore change the offsets of some existing nodes.
1272  *
1273  * returns:
1274  *	0, on success
1275  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1276  *		contain the new property value
1277  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1278  *	-FDT_ERR_BADLAYOUT,
1279  *	-FDT_ERR_BADMAGIC,
1280  *	-FDT_ERR_BADVERSION,
1281  *	-FDT_ERR_BADSTATE,
1282  *	-FDT_ERR_BADSTRUCTURE,
1283  *	-FDT_ERR_BADLAYOUT,
1284  *	-FDT_ERR_TRUNCATED, standard meanings
1285  */
1286 static inline int fdt_setprop_u64(void *fdt, int nodeoffset, const char *name,
1287 				  uint64_t val)
1288 {
1289 	fdt64_t tmp = cpu_to_fdt64(val);
1290 	return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1291 }
1292 
1293 /**
1294  * fdt_setprop_cell - set a property to a single cell value
1295  *
1296  * This is an alternative name for fdt_setprop_u32()
1297  */
1298 static inline int fdt_setprop_cell(void *fdt, int nodeoffset, const char *name,
1299 				   uint32_t val)
1300 {
1301 	return fdt_setprop_u32(fdt, nodeoffset, name, val);
1302 }
1303 
1304 /**
1305  * fdt_setprop_string - set a property to a string value
1306  * @fdt: pointer to the device tree blob
1307  * @nodeoffset: offset of the node whose property to change
1308  * @name: name of the property to change
1309  * @str: string value for the property
1310  *
1311  * fdt_setprop_string() sets the value of the named property in the
1312  * given node to the given string value (using the length of the
1313  * string to determine the new length of the property), or creates a
1314  * new property with that value if it does not already exist.
1315  *
1316  * This function may insert or delete data from the blob, and will
1317  * therefore change the offsets of some existing nodes.
1318  *
1319  * returns:
1320  *	0, on success
1321  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1322  *		contain the new property value
1323  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1324  *	-FDT_ERR_BADLAYOUT,
1325  *	-FDT_ERR_BADMAGIC,
1326  *	-FDT_ERR_BADVERSION,
1327  *	-FDT_ERR_BADSTATE,
1328  *	-FDT_ERR_BADSTRUCTURE,
1329  *	-FDT_ERR_BADLAYOUT,
1330  *	-FDT_ERR_TRUNCATED, standard meanings
1331  */
1332 #define fdt_setprop_string(fdt, nodeoffset, name, str) \
1333 	fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1334 
1335 /**
1336  * fdt_appendprop - append to or create a property
1337  * @fdt: pointer to the device tree blob
1338  * @nodeoffset: offset of the node whose property to change
1339  * @name: name of the property to append to
1340  * @val: pointer to data to append to the property value
1341  * @len: length of the data to append to the property value
1342  *
1343  * fdt_appendprop() appends the value to the named property in the
1344  * given node, creating the property if it does not already exist.
1345  *
1346  * This function may insert data into the blob, and will therefore
1347  * change the offsets of some existing nodes.
1348  *
1349  * returns:
1350  *	0, on success
1351  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1352  *		contain the new property value
1353  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1354  *	-FDT_ERR_BADLAYOUT,
1355  *	-FDT_ERR_BADMAGIC,
1356  *	-FDT_ERR_BADVERSION,
1357  *	-FDT_ERR_BADSTATE,
1358  *	-FDT_ERR_BADSTRUCTURE,
1359  *	-FDT_ERR_BADLAYOUT,
1360  *	-FDT_ERR_TRUNCATED, standard meanings
1361  */
1362 int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
1363 		   const void *val, int len);
1364 
1365 /**
1366  * fdt_appendprop_u32 - append a 32-bit integer value to a property
1367  * @fdt: pointer to the device tree blob
1368  * @nodeoffset: offset of the node whose property to change
1369  * @name: name of the property to change
1370  * @val: 32-bit integer value to append to the property (native endian)
1371  *
1372  * fdt_appendprop_u32() appends the given 32-bit integer value
1373  * (converting to big-endian if necessary) to the value of the named
1374  * property in the given node, or creates a new property with that
1375  * value if it does not already exist.
1376  *
1377  * This function may insert data into the blob, and will therefore
1378  * change the offsets of some existing nodes.
1379  *
1380  * returns:
1381  *	0, on success
1382  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1383  *		contain the new property value
1384  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1385  *	-FDT_ERR_BADLAYOUT,
1386  *	-FDT_ERR_BADMAGIC,
1387  *	-FDT_ERR_BADVERSION,
1388  *	-FDT_ERR_BADSTATE,
1389  *	-FDT_ERR_BADSTRUCTURE,
1390  *	-FDT_ERR_BADLAYOUT,
1391  *	-FDT_ERR_TRUNCATED, standard meanings
1392  */
1393 static inline int fdt_appendprop_u32(void *fdt, int nodeoffset,
1394 				     const char *name, uint32_t val)
1395 {
1396 	fdt32_t tmp = cpu_to_fdt32(val);
1397 	return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1398 }
1399 
1400 /**
1401  * fdt_appendprop_u64 - append a 64-bit integer value to a property
1402  * @fdt: pointer to the device tree blob
1403  * @nodeoffset: offset of the node whose property to change
1404  * @name: name of the property to change
1405  * @val: 64-bit integer value to append to the property (native endian)
1406  *
1407  * fdt_appendprop_u64() appends the given 64-bit integer value
1408  * (converting to big-endian if necessary) to the value of the named
1409  * property in the given node, or creates a new property with that
1410  * value if it does not already exist.
1411  *
1412  * This function may insert data into the blob, and will therefore
1413  * change the offsets of some existing nodes.
1414  *
1415  * returns:
1416  *	0, on success
1417  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1418  *		contain the new property value
1419  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1420  *	-FDT_ERR_BADLAYOUT,
1421  *	-FDT_ERR_BADMAGIC,
1422  *	-FDT_ERR_BADVERSION,
1423  *	-FDT_ERR_BADSTATE,
1424  *	-FDT_ERR_BADSTRUCTURE,
1425  *	-FDT_ERR_BADLAYOUT,
1426  *	-FDT_ERR_TRUNCATED, standard meanings
1427  */
1428 static inline int fdt_appendprop_u64(void *fdt, int nodeoffset,
1429 				     const char *name, uint64_t val)
1430 {
1431 	fdt64_t tmp = cpu_to_fdt64(val);
1432 	return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1433 }
1434 
1435 /**
1436  * fdt_appendprop_cell - append a single cell value to a property
1437  *
1438  * This is an alternative name for fdt_appendprop_u32()
1439  */
1440 static inline int fdt_appendprop_cell(void *fdt, int nodeoffset,
1441 				      const char *name, uint32_t val)
1442 {
1443 	return fdt_appendprop_u32(fdt, nodeoffset, name, val);
1444 }
1445 
1446 /**
1447  * fdt_appendprop_string - append a string to a property
1448  * @fdt: pointer to the device tree blob
1449  * @nodeoffset: offset of the node whose property to change
1450  * @name: name of the property to change
1451  * @str: string value to append to the property
1452  *
1453  * fdt_appendprop_string() appends the given string to the value of
1454  * the named property in the given node, or creates a new property
1455  * with that value if it does not already exist.
1456  *
1457  * This function may insert data into the blob, and will therefore
1458  * change the offsets of some existing nodes.
1459  *
1460  * returns:
1461  *	0, on success
1462  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1463  *		contain the new property value
1464  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1465  *	-FDT_ERR_BADLAYOUT,
1466  *	-FDT_ERR_BADMAGIC,
1467  *	-FDT_ERR_BADVERSION,
1468  *	-FDT_ERR_BADSTATE,
1469  *	-FDT_ERR_BADSTRUCTURE,
1470  *	-FDT_ERR_BADLAYOUT,
1471  *	-FDT_ERR_TRUNCATED, standard meanings
1472  */
1473 #define fdt_appendprop_string(fdt, nodeoffset, name, str) \
1474 	fdt_appendprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1475 
1476 /**
1477  * fdt_delprop - delete a property
1478  * @fdt: pointer to the device tree blob
1479  * @nodeoffset: offset of the node whose property to nop
1480  * @name: name of the property to nop
1481  *
1482  * fdt_del_property() will delete the given property.
1483  *
1484  * This function will delete data from the blob, and will therefore
1485  * change the offsets of some existing nodes.
1486  *
1487  * returns:
1488  *	0, on success
1489  *	-FDT_ERR_NOTFOUND, node does not have the named property
1490  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1491  *	-FDT_ERR_BADLAYOUT,
1492  *	-FDT_ERR_BADMAGIC,
1493  *	-FDT_ERR_BADVERSION,
1494  *	-FDT_ERR_BADSTATE,
1495  *	-FDT_ERR_BADSTRUCTURE,
1496  *	-FDT_ERR_TRUNCATED, standard meanings
1497  */
1498 int fdt_delprop(void *fdt, int nodeoffset, const char *name);
1499 
1500 /**
1501  * fdt_add_subnode_namelen - creates a new node based on substring
1502  * @fdt: pointer to the device tree blob
1503  * @parentoffset: structure block offset of a node
1504  * @name: name of the subnode to locate
1505  * @namelen: number of characters of name to consider
1506  *
1507  * Identical to fdt_add_subnode(), but use only the first namelen
1508  * characters of name as the name of the new node.  This is useful for
1509  * creating subnodes based on a portion of a larger string, such as a
1510  * full path.
1511  */
1512 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
1513 			    const char *name, int namelen);
1514 
1515 /**
1516  * fdt_add_subnode - creates a new node
1517  * @fdt: pointer to the device tree blob
1518  * @parentoffset: structure block offset of a node
1519  * @name: name of the subnode to locate
1520  *
1521  * fdt_add_subnode() creates a new node as a subnode of the node at
1522  * structure block offset parentoffset, with the given name (which
1523  * should include the unit address, if any).
1524  *
1525  * This function will insert data into the blob, and will therefore
1526  * change the offsets of some existing nodes.
1527 
1528  * returns:
1529  *	structure block offset of the created nodeequested subnode (>=0), on success
1530  *	-FDT_ERR_NOTFOUND, if the requested subnode does not exist
1531  *	-FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag
1532  *	-FDT_ERR_EXISTS, if the node at parentoffset already has a subnode of
1533  *		the given name
1534  *	-FDT_ERR_NOSPACE, if there is insufficient free space in the
1535  *		blob to contain the new node
1536  *	-FDT_ERR_NOSPACE
1537  *	-FDT_ERR_BADLAYOUT
1538  *      -FDT_ERR_BADMAGIC,
1539  *	-FDT_ERR_BADVERSION,
1540  *	-FDT_ERR_BADSTATE,
1541  *	-FDT_ERR_BADSTRUCTURE,
1542  *	-FDT_ERR_TRUNCATED, standard meanings.
1543  */
1544 int fdt_add_subnode(void *fdt, int parentoffset, const char *name);
1545 
1546 /**
1547  * fdt_del_node - delete a node (subtree)
1548  * @fdt: pointer to the device tree blob
1549  * @nodeoffset: offset of the node to nop
1550  *
1551  * fdt_del_node() will remove the given node, including all its
1552  * subnodes if any, from the blob.
1553  *
1554  * This function will delete data from the blob, and will therefore
1555  * change the offsets of some existing nodes.
1556  *
1557  * returns:
1558  *	0, on success
1559  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1560  *	-FDT_ERR_BADLAYOUT,
1561  *	-FDT_ERR_BADMAGIC,
1562  *	-FDT_ERR_BADVERSION,
1563  *	-FDT_ERR_BADSTATE,
1564  *	-FDT_ERR_BADSTRUCTURE,
1565  *	-FDT_ERR_TRUNCATED, standard meanings
1566  */
1567 int fdt_del_node(void *fdt, int nodeoffset);
1568 
1569 /**********************************************************************/
1570 /* Debugging / informational functions                                */
1571 /**********************************************************************/
1572 
1573 const char *fdt_strerror(int errval);
1574 
1575 #endif /* _LIBFDT_H */
1576