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