xref: /openbmc/u-boot/scripts/dtc/libfdt/libfdt.h (revision 9dbaebcf)
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: Attempted 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 	 * This can be caused either by an invalid phandle property
84 	 * length, or the phandle value was either 0 or -1, which are
85 	 * not permitted. */
86 #define FDT_ERR_BADSTATE	7
87 	/* FDT_ERR_BADSTATE: Function was passed an incomplete device
88 	 * tree created by the sequential-write functions, which is
89 	 * not sufficiently complete for the requested operation. */
90 
91 /* Error codes: codes for bad device tree blobs */
92 #define FDT_ERR_TRUNCATED	8
93 	/* FDT_ERR_TRUNCATED: Structure block of the given device tree
94 	 * ends without an FDT_END tag. */
95 #define FDT_ERR_BADMAGIC	9
96 	/* FDT_ERR_BADMAGIC: Given "device tree" appears not to be a
97 	 * device tree at all - it is missing the flattened device
98 	 * tree magic number. */
99 #define FDT_ERR_BADVERSION	10
100 	/* FDT_ERR_BADVERSION: Given device tree has a version which
101 	 * can't be handled by the requested operation.  For
102 	 * read-write functions, this may mean that fdt_open_into() is
103 	 * required to convert the tree to the expected version. */
104 #define FDT_ERR_BADSTRUCTURE	11
105 	/* FDT_ERR_BADSTRUCTURE: Given device tree has a corrupt
106 	 * structure block or other serious error (e.g. misnested
107 	 * nodes, or subnodes preceding properties). */
108 #define FDT_ERR_BADLAYOUT	12
109 	/* FDT_ERR_BADLAYOUT: For read-write functions, the given
110 	 * device tree has it's sub-blocks in an order that the
111 	 * function can't handle (memory reserve map, then structure,
112 	 * then strings).  Use fdt_open_into() to reorganize the tree
113 	 * into a form suitable for the read-write operations. */
114 
115 /* "Can't happen" error indicating a bug in libfdt */
116 #define FDT_ERR_INTERNAL	13
117 	/* FDT_ERR_INTERNAL: libfdt has failed an internal assertion.
118 	 * Should never be returned, if it is, it indicates a bug in
119 	 * libfdt itself. */
120 
121 /* Errors in device tree content */
122 #define FDT_ERR_BADNCELLS	14
123 	/* FDT_ERR_BADNCELLS: Device tree has a #address-cells, #size-cells
124 	 * or similar property with a bad format or value */
125 
126 #define FDT_ERR_BADVALUE	15
127 	/* FDT_ERR_BADVALUE: Device tree has a property with an unexpected
128 	 * value. For example: a property expected to contain a string list
129 	 * is not NUL-terminated within the length of its value. */
130 
131 #define FDT_ERR_BADOVERLAY	16
132 	/* FDT_ERR_BADOVERLAY: The device tree overlay, while
133 	 * correctly structured, cannot be applied due to some
134 	 * unexpected or missing value, property or node. */
135 
136 #define FDT_ERR_NOPHANDLES	17
137 	/* FDT_ERR_NOPHANDLES: The device tree doesn't have any
138 	 * phandle available anymore without causing an overflow */
139 
140 #define FDT_ERR_MAX		17
141 
142 /**********************************************************************/
143 /* Low-level functions (you probably don't need these)                */
144 /**********************************************************************/
145 
146 #ifndef SWIG /* This function is not useful in Python */
147 const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int checklen);
148 #endif
149 static inline void *fdt_offset_ptr_w(void *fdt, int offset, int checklen)
150 {
151 	return (void *)(uintptr_t)fdt_offset_ptr(fdt, offset, checklen);
152 }
153 
154 uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset);
155 
156 /**********************************************************************/
157 /* Traversal functions                                                */
158 /**********************************************************************/
159 
160 int fdt_next_node(const void *fdt, int offset, int *depth);
161 
162 /**
163  * fdt_first_subnode() - get offset of first direct subnode
164  *
165  * @fdt:	FDT blob
166  * @offset:	Offset of node to check
167  * @return offset of first subnode, or -FDT_ERR_NOTFOUND if there is none
168  */
169 int fdt_first_subnode(const void *fdt, int offset);
170 
171 /**
172  * fdt_next_subnode() - get offset of next direct subnode
173  *
174  * After first calling fdt_first_subnode(), call this function repeatedly to
175  * get direct subnodes of a parent node.
176  *
177  * @fdt:	FDT blob
178  * @offset:	Offset of previous subnode
179  * @return offset of next subnode, or -FDT_ERR_NOTFOUND if there are no more
180  * subnodes
181  */
182 int fdt_next_subnode(const void *fdt, int offset);
183 
184 /**
185  * fdt_for_each_subnode - iterate over all subnodes of a parent
186  *
187  * @node:	child node (int, lvalue)
188  * @fdt:	FDT blob (const void *)
189  * @parent:	parent node (int)
190  *
191  * This is actually a wrapper around a for loop and would be used like so:
192  *
193  *	fdt_for_each_subnode(node, fdt, parent) {
194  *		Use node
195  *		...
196  *	}
197  *
198  *	if ((node < 0) && (node != -FDT_ERR_NOT_FOUND)) {
199  *		Error handling
200  *	}
201  *
202  * Note that this is implemented as a macro and @node is used as
203  * iterator in the loop. The parent variable be constant or even a
204  * literal.
205  *
206  */
207 #define fdt_for_each_subnode(node, fdt, parent)		\
208 	for (node = fdt_first_subnode(fdt, parent);	\
209 	     node >= 0;					\
210 	     node = fdt_next_subnode(fdt, node))
211 
212 /**********************************************************************/
213 /* General functions                                                  */
214 /**********************************************************************/
215 #define fdt_get_header(fdt, field) \
216 	(fdt32_to_cpu(((const struct fdt_header *)(fdt))->field))
217 #define fdt_magic(fdt)			(fdt_get_header(fdt, magic))
218 #define fdt_totalsize(fdt)		(fdt_get_header(fdt, totalsize))
219 #define fdt_off_dt_struct(fdt)		(fdt_get_header(fdt, off_dt_struct))
220 #define fdt_off_dt_strings(fdt)		(fdt_get_header(fdt, off_dt_strings))
221 #define fdt_off_mem_rsvmap(fdt)		(fdt_get_header(fdt, off_mem_rsvmap))
222 #define fdt_version(fdt)		(fdt_get_header(fdt, version))
223 #define fdt_last_comp_version(fdt)	(fdt_get_header(fdt, last_comp_version))
224 #define fdt_boot_cpuid_phys(fdt)	(fdt_get_header(fdt, boot_cpuid_phys))
225 #define fdt_size_dt_strings(fdt)	(fdt_get_header(fdt, size_dt_strings))
226 #define fdt_size_dt_struct(fdt)		(fdt_get_header(fdt, size_dt_struct))
227 
228 #define __fdt_set_hdr(name) \
229 	static inline void fdt_set_##name(void *fdt, uint32_t val) \
230 	{ \
231 		struct fdt_header *fdth = (struct fdt_header *)fdt; \
232 		fdth->name = cpu_to_fdt32(val); \
233 	}
234 __fdt_set_hdr(magic);
235 __fdt_set_hdr(totalsize);
236 __fdt_set_hdr(off_dt_struct);
237 __fdt_set_hdr(off_dt_strings);
238 __fdt_set_hdr(off_mem_rsvmap);
239 __fdt_set_hdr(version);
240 __fdt_set_hdr(last_comp_version);
241 __fdt_set_hdr(boot_cpuid_phys);
242 __fdt_set_hdr(size_dt_strings);
243 __fdt_set_hdr(size_dt_struct);
244 #undef __fdt_set_hdr
245 
246 /**
247  * fdt_check_header - sanity check a device tree or possible device tree
248  * @fdt: pointer to data which might be a flattened device tree
249  *
250  * fdt_check_header() checks that the given buffer contains what
251  * appears to be a flattened device tree with sane information in its
252  * header.
253  *
254  * returns:
255  *     0, if the buffer appears to contain a valid device tree
256  *     -FDT_ERR_BADMAGIC,
257  *     -FDT_ERR_BADVERSION,
258  *     -FDT_ERR_BADSTATE, standard meanings, as above
259  */
260 int fdt_check_header(const void *fdt);
261 
262 /**
263  * fdt_move - move a device tree around in memory
264  * @fdt: pointer to the device tree to move
265  * @buf: pointer to memory where the device is to be moved
266  * @bufsize: size of the memory space at buf
267  *
268  * fdt_move() relocates, if possible, the device tree blob located at
269  * fdt to the buffer at buf of size bufsize.  The buffer may overlap
270  * with the existing device tree blob at fdt.  Therefore,
271  *     fdt_move(fdt, fdt, fdt_totalsize(fdt))
272  * should always succeed.
273  *
274  * returns:
275  *     0, on success
276  *     -FDT_ERR_NOSPACE, bufsize is insufficient to contain the device tree
277  *     -FDT_ERR_BADMAGIC,
278  *     -FDT_ERR_BADVERSION,
279  *     -FDT_ERR_BADSTATE, standard meanings
280  */
281 int fdt_move(const void *fdt, void *buf, int bufsize);
282 
283 /**********************************************************************/
284 /* Read-only functions                                                */
285 /**********************************************************************/
286 
287 /**
288  * fdt_string - retrieve a string from the strings block of a device tree
289  * @fdt: pointer to the device tree blob
290  * @stroffset: offset of the string within the strings block (native endian)
291  *
292  * fdt_string() retrieves a pointer to a single string from the
293  * strings block of the device tree blob at fdt.
294  *
295  * returns:
296  *     a pointer to the string, on success
297  *     NULL, if stroffset is out of bounds
298  */
299 const char *fdt_string(const void *fdt, int stroffset);
300 
301 /**
302  * fdt_get_max_phandle - retrieves the highest phandle in a tree
303  * @fdt: pointer to the device tree blob
304  *
305  * fdt_get_max_phandle retrieves the highest phandle in the given
306  * device tree. This will ignore badly formatted phandles, or phandles
307  * with a value of 0 or -1.
308  *
309  * returns:
310  *      the highest phandle on success
311  *      0, if no phandle was found in the device tree
312  *      -1, if an error occurred
313  */
314 uint32_t fdt_get_max_phandle(const void *fdt);
315 
316 /**
317  * fdt_num_mem_rsv - retrieve the number of memory reserve map entries
318  * @fdt: pointer to the device tree blob
319  *
320  * Returns the number of entries in the device tree blob's memory
321  * reservation map.  This does not include the terminating 0,0 entry
322  * or any other (0,0) entries reserved for expansion.
323  *
324  * returns:
325  *     the number of entries
326  */
327 int fdt_num_mem_rsv(const void *fdt);
328 
329 /**
330  * fdt_get_mem_rsv - retrieve one memory reserve map entry
331  * @fdt: pointer to the device tree blob
332  * @address, @size: pointers to 64-bit variables
333  *
334  * On success, *address and *size will contain the address and size of
335  * the n-th reserve map entry from the device tree blob, in
336  * native-endian format.
337  *
338  * returns:
339  *     0, on success
340  *     -FDT_ERR_BADMAGIC,
341  *     -FDT_ERR_BADVERSION,
342  *     -FDT_ERR_BADSTATE, standard meanings
343  */
344 int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size);
345 
346 /**
347  * fdt_subnode_offset_namelen - find a subnode based on substring
348  * @fdt: pointer to the device tree blob
349  * @parentoffset: structure block offset of a node
350  * @name: name of the subnode to locate
351  * @namelen: number of characters of name to consider
352  *
353  * Identical to fdt_subnode_offset(), but only examine the first
354  * namelen characters of name for matching the subnode name.  This is
355  * useful for finding subnodes based on a portion of a larger string,
356  * such as a full path.
357  */
358 #ifndef SWIG /* Not available in Python */
359 int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
360 			       const char *name, int namelen);
361 #endif
362 /**
363  * fdt_subnode_offset - find a subnode of a given node
364  * @fdt: pointer to the device tree blob
365  * @parentoffset: structure block offset of a node
366  * @name: name of the subnode to locate
367  *
368  * fdt_subnode_offset() finds a subnode of the node at structure block
369  * offset parentoffset with the given name.  name may include a unit
370  * address, in which case fdt_subnode_offset() will find the subnode
371  * with that unit address, or the unit address may be omitted, in
372  * which case fdt_subnode_offset() will find an arbitrary subnode
373  * whose name excluding unit address matches the given name.
374  *
375  * returns:
376  *	structure block offset of the requested subnode (>=0), on success
377  *	-FDT_ERR_NOTFOUND, if the requested subnode does not exist
378  *	-FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE
379  *		tag
380  *	-FDT_ERR_BADMAGIC,
381  *	-FDT_ERR_BADVERSION,
382  *	-FDT_ERR_BADSTATE,
383  *	-FDT_ERR_BADSTRUCTURE,
384  *	-FDT_ERR_TRUNCATED, standard meanings.
385  */
386 int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name);
387 
388 /**
389  * fdt_path_offset_namelen - find a tree node by its full path
390  * @fdt: pointer to the device tree blob
391  * @path: full path of the node to locate
392  * @namelen: number of characters of path to consider
393  *
394  * Identical to fdt_path_offset(), but only consider the first namelen
395  * characters of path as the path name.
396  */
397 #ifndef SWIG /* Not available in Python */
398 int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen);
399 #endif
400 
401 /**
402  * fdt_path_offset - find a tree node by its full path
403  * @fdt: pointer to the device tree blob
404  * @path: full path of the node to locate
405  *
406  * fdt_path_offset() finds a node of a given path in the device tree.
407  * Each path component may omit the unit address portion, but the
408  * results of this are undefined if any such path component is
409  * ambiguous (that is if there are multiple nodes at the relevant
410  * level matching the given component, differentiated only by unit
411  * address).
412  *
413  * returns:
414  *	structure block offset of the node with the requested path (>=0), on
415  *		success
416  *	-FDT_ERR_BADPATH, given path does not begin with '/' or is invalid
417  *	-FDT_ERR_NOTFOUND, if the requested node does not exist
418  *      -FDT_ERR_BADMAGIC,
419  *	-FDT_ERR_BADVERSION,
420  *	-FDT_ERR_BADSTATE,
421  *	-FDT_ERR_BADSTRUCTURE,
422  *	-FDT_ERR_TRUNCATED, standard meanings.
423  */
424 int fdt_path_offset(const void *fdt, const char *path);
425 
426 /**
427  * fdt_get_name - retrieve the name of a given node
428  * @fdt: pointer to the device tree blob
429  * @nodeoffset: structure block offset of the starting node
430  * @lenp: pointer to an integer variable (will be overwritten) or NULL
431  *
432  * fdt_get_name() retrieves the name (including unit address) of the
433  * device tree node at structure block offset nodeoffset.  If lenp is
434  * non-NULL, the length of this name is also returned, in the integer
435  * pointed to by lenp.
436  *
437  * returns:
438  *	pointer to the node's name, on success
439  *		If lenp is non-NULL, *lenp contains the length of that name
440  *			(>=0)
441  *	NULL, on error
442  *		if lenp is non-NULL *lenp contains an error code (<0):
443  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE
444  *			tag
445  *		-FDT_ERR_BADMAGIC,
446  *		-FDT_ERR_BADVERSION,
447  *		-FDT_ERR_BADSTATE, standard meanings
448  */
449 const char *fdt_get_name(const void *fdt, int nodeoffset, int *lenp);
450 
451 /**
452  * fdt_first_property_offset - find the offset of a node's first property
453  * @fdt: pointer to the device tree blob
454  * @nodeoffset: structure block offset of a node
455  *
456  * fdt_first_property_offset() finds the first property of the node at
457  * the given structure block offset.
458  *
459  * returns:
460  *	structure block offset of the property (>=0), on success
461  *	-FDT_ERR_NOTFOUND, if the requested node has no properties
462  *	-FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_BEGIN_NODE tag
463  *      -FDT_ERR_BADMAGIC,
464  *	-FDT_ERR_BADVERSION,
465  *	-FDT_ERR_BADSTATE,
466  *	-FDT_ERR_BADSTRUCTURE,
467  *	-FDT_ERR_TRUNCATED, standard meanings.
468  */
469 int fdt_first_property_offset(const void *fdt, int nodeoffset);
470 
471 /**
472  * fdt_next_property_offset - step through a node's properties
473  * @fdt: pointer to the device tree blob
474  * @offset: structure block offset of a property
475  *
476  * fdt_next_property_offset() finds the property immediately after the
477  * one at the given structure block offset.  This will be a property
478  * of the same node as the given property.
479  *
480  * returns:
481  *	structure block offset of the next property (>=0), on success
482  *	-FDT_ERR_NOTFOUND, if the given property is the last in its node
483  *	-FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_PROP tag
484  *      -FDT_ERR_BADMAGIC,
485  *	-FDT_ERR_BADVERSION,
486  *	-FDT_ERR_BADSTATE,
487  *	-FDT_ERR_BADSTRUCTURE,
488  *	-FDT_ERR_TRUNCATED, standard meanings.
489  */
490 int fdt_next_property_offset(const void *fdt, int offset);
491 
492 /**
493  * fdt_for_each_property_offset - iterate over all properties of a node
494  *
495  * @property_offset:	property offset (int, lvalue)
496  * @fdt:		FDT blob (const void *)
497  * @node:		node offset (int)
498  *
499  * This is actually a wrapper around a for loop and would be used like so:
500  *
501  *	fdt_for_each_property_offset(property, fdt, node) {
502  *		Use property
503  *		...
504  *	}
505  *
506  *	if ((property < 0) && (property != -FDT_ERR_NOT_FOUND)) {
507  *		Error handling
508  *	}
509  *
510  * Note that this is implemented as a macro and property is used as
511  * iterator in the loop. The node variable can be constant or even a
512  * literal.
513  */
514 #define fdt_for_each_property_offset(property, fdt, node)	\
515 	for (property = fdt_first_property_offset(fdt, node);	\
516 	     property >= 0;					\
517 	     property = fdt_next_property_offset(fdt, property))
518 
519 /**
520  * fdt_get_property_by_offset - retrieve the property at a given offset
521  * @fdt: pointer to the device tree blob
522  * @offset: offset of the property to retrieve
523  * @lenp: pointer to an integer variable (will be overwritten) or NULL
524  *
525  * fdt_get_property_by_offset() retrieves a pointer to the
526  * fdt_property structure within the device tree blob at the given
527  * offset.  If lenp is non-NULL, the length of the property value is
528  * also returned, in the integer pointed to by lenp.
529  *
530  * returns:
531  *	pointer to the structure representing the property
532  *		if lenp is non-NULL, *lenp contains the length of the property
533  *		value (>=0)
534  *	NULL, on error
535  *		if lenp is non-NULL, *lenp contains an error code (<0):
536  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
537  *		-FDT_ERR_BADMAGIC,
538  *		-FDT_ERR_BADVERSION,
539  *		-FDT_ERR_BADSTATE,
540  *		-FDT_ERR_BADSTRUCTURE,
541  *		-FDT_ERR_TRUNCATED, standard meanings
542  */
543 const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
544 						      int offset,
545 						      int *lenp);
546 
547 /**
548  * fdt_get_property_namelen - find a property based on substring
549  * @fdt: pointer to the device tree blob
550  * @nodeoffset: offset of the node whose property to find
551  * @name: name of the property to find
552  * @namelen: number of characters of name to consider
553  * @lenp: pointer to an integer variable (will be overwritten) or NULL
554  *
555  * Identical to fdt_get_property(), but only examine the first namelen
556  * characters of name for matching the property name.
557  */
558 #ifndef SWIG /* Not available in Python */
559 const struct fdt_property *fdt_get_property_namelen(const void *fdt,
560 						    int nodeoffset,
561 						    const char *name,
562 						    int namelen, int *lenp);
563 #endif
564 
565 /**
566  * fdt_get_property - find a given property in a given node
567  * @fdt: pointer to the device tree blob
568  * @nodeoffset: offset of the node whose property to find
569  * @name: name of the property to find
570  * @lenp: pointer to an integer variable (will be overwritten) or NULL
571  *
572  * fdt_get_property() retrieves a pointer to the fdt_property
573  * structure within the device tree blob corresponding to the property
574  * named 'name' of the node at offset nodeoffset.  If lenp is
575  * non-NULL, the length of the property value is also returned, in the
576  * integer pointed to by lenp.
577  *
578  * returns:
579  *	pointer to the structure representing the property
580  *		if lenp is non-NULL, *lenp contains the length of the property
581  *		value (>=0)
582  *	NULL, on error
583  *		if lenp is non-NULL, *lenp contains an error code (<0):
584  *		-FDT_ERR_NOTFOUND, node does not have named property
585  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE
586  *			tag
587  *		-FDT_ERR_BADMAGIC,
588  *		-FDT_ERR_BADVERSION,
589  *		-FDT_ERR_BADSTATE,
590  *		-FDT_ERR_BADSTRUCTURE,
591  *		-FDT_ERR_TRUNCATED, standard meanings
592  */
593 const struct fdt_property *fdt_get_property(const void *fdt, int nodeoffset,
594 					    const char *name, int *lenp);
595 static inline struct fdt_property *fdt_get_property_w(void *fdt, int nodeoffset,
596 						      const char *name,
597 						      int *lenp)
598 {
599 	return (struct fdt_property *)(uintptr_t)
600 		fdt_get_property(fdt, nodeoffset, name, lenp);
601 }
602 
603 /**
604  * fdt_getprop_by_offset - retrieve the value of a property at a given offset
605  * @fdt: pointer to the device tree blob
606  * @ffset: offset of the property to read
607  * @namep: pointer to a string variable (will be overwritten) or NULL
608  * @lenp: pointer to an integer variable (will be overwritten) or NULL
609  *
610  * fdt_getprop_by_offset() retrieves a pointer to the value of the
611  * property at structure block offset 'offset' (this will be a pointer
612  * to within the device blob itself, not a copy of the value).  If
613  * lenp is non-NULL, the length of the property value is also
614  * returned, in the integer pointed to by lenp.  If namep is non-NULL,
615  * the property's namne will also be returned in the char * pointed to
616  * by namep (this will be a pointer to within the device tree's string
617  * block, not a new copy of the name).
618  *
619  * returns:
620  *	pointer to the property's value
621  *		if lenp is non-NULL, *lenp contains the length of the property
622  *		value (>=0)
623  *		if namep is non-NULL *namep contiains a pointer to the property
624  *		name.
625  *	NULL, on error
626  *		if lenp is non-NULL, *lenp contains an error code (<0):
627  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
628  *		-FDT_ERR_BADMAGIC,
629  *		-FDT_ERR_BADVERSION,
630  *		-FDT_ERR_BADSTATE,
631  *		-FDT_ERR_BADSTRUCTURE,
632  *		-FDT_ERR_TRUNCATED, standard meanings
633  */
634 #ifndef SWIG /* This function is not useful in Python */
635 const void *fdt_getprop_by_offset(const void *fdt, int offset,
636 				  const char **namep, int *lenp);
637 #endif
638 
639 /**
640  * fdt_getprop_namelen - get property value based on substring
641  * @fdt: pointer to the device tree blob
642  * @nodeoffset: offset of the node whose property to find
643  * @name: name of the property to find
644  * @namelen: number of characters of name to consider
645  * @lenp: pointer to an integer variable (will be overwritten) or NULL
646  *
647  * Identical to fdt_getprop(), but only examine the first namelen
648  * characters of name for matching the property name.
649  */
650 #ifndef SWIG /* Not available in Python */
651 const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
652 				const char *name, int namelen, int *lenp);
653 static inline void *fdt_getprop_namelen_w(void *fdt, int nodeoffset,
654 					  const char *name, int namelen,
655 					  int *lenp)
656 {
657 	return (void *)(uintptr_t)fdt_getprop_namelen(fdt, nodeoffset, name,
658 						      namelen, lenp);
659 }
660 #endif
661 
662 /**
663  * fdt_getprop - retrieve the value of a given property
664  * @fdt: pointer to the device tree blob
665  * @nodeoffset: offset of the node whose property to find
666  * @name: name of the property to find
667  * @lenp: pointer to an integer variable (will be overwritten) or NULL
668  *
669  * fdt_getprop() retrieves a pointer to the value of the property
670  * named 'name' of the node at offset nodeoffset (this will be a
671  * pointer to within the device blob itself, not a copy of the value).
672  * If lenp is non-NULL, the length of the property value is also
673  * returned, in the integer pointed to by lenp.
674  *
675  * returns:
676  *	pointer to the property's value
677  *		if lenp is non-NULL, *lenp contains the length of the property
678  *		value (>=0)
679  *	NULL, on error
680  *		if lenp is non-NULL, *lenp contains an error code (<0):
681  *		-FDT_ERR_NOTFOUND, node does not have named property
682  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE
683  *			tag
684  *		-FDT_ERR_BADMAGIC,
685  *		-FDT_ERR_BADVERSION,
686  *		-FDT_ERR_BADSTATE,
687  *		-FDT_ERR_BADSTRUCTURE,
688  *		-FDT_ERR_TRUNCATED, standard meanings
689  */
690 const void *fdt_getprop(const void *fdt, int nodeoffset,
691 			const char *name, int *lenp);
692 static inline void *fdt_getprop_w(void *fdt, int nodeoffset,
693 				  const char *name, int *lenp)
694 {
695 	return (void *)(uintptr_t)fdt_getprop(fdt, nodeoffset, name, lenp);
696 }
697 
698 /**
699  * fdt_get_phandle - retrieve the phandle of a given node
700  * @fdt: pointer to the device tree blob
701  * @nodeoffset: structure block offset of the node
702  *
703  * fdt_get_phandle() retrieves the phandle of the device tree node at
704  * structure block offset nodeoffset.
705  *
706  * returns:
707  *	the phandle of the node at nodeoffset, on success (!= 0, != -1)
708  *	0, if the node has no phandle, or another error occurs
709  */
710 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset);
711 
712 /**
713  * fdt_get_alias_namelen - get alias based on substring
714  * @fdt: pointer to the device tree blob
715  * @name: name of the alias th look up
716  * @namelen: number of characters of name to consider
717  *
718  * Identical to fdt_get_alias(), but only examine the first namelen
719  * characters of name for matching the alias name.
720  */
721 #ifndef SWIG /* Not available in Python */
722 const char *fdt_get_alias_namelen(const void *fdt,
723 				  const char *name, int namelen);
724 #endif
725 
726 /**
727  * fdt_get_alias - retrieve the path referenced by a given alias
728  * @fdt: pointer to the device tree blob
729  * @name: name of the alias th look up
730  *
731  * fdt_get_alias() retrieves the value of a given alias.  That is, the
732  * value of the property named 'name' in the node /aliases.
733  *
734  * returns:
735  *	a pointer to the expansion of the alias named 'name', if it exists
736  *	NULL, if the given alias or the /aliases node does not exist
737  */
738 const char *fdt_get_alias(const void *fdt, const char *name);
739 
740 /**
741  * fdt_get_path - determine the full path of a node
742  * @fdt: pointer to the device tree blob
743  * @nodeoffset: offset of the node whose path to find
744  * @buf: character buffer to contain the returned path (will be overwritten)
745  * @buflen: size of the character buffer at buf
746  *
747  * fdt_get_path() computes the full path of the node at offset
748  * nodeoffset, and records that path in the buffer at buf.
749  *
750  * NOTE: This function is expensive, as it must scan the device tree
751  * structure from the start to nodeoffset.
752  *
753  * returns:
754  *	0, on success
755  *		buf contains the absolute path of the node at
756  *		nodeoffset, as a NUL-terminated string.
757  *	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
758  *	-FDT_ERR_NOSPACE, the path of the given node is longer than (bufsize-1)
759  *		characters and will not fit in the given buffer.
760  *	-FDT_ERR_BADMAGIC,
761  *	-FDT_ERR_BADVERSION,
762  *	-FDT_ERR_BADSTATE,
763  *	-FDT_ERR_BADSTRUCTURE, standard meanings
764  */
765 int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen);
766 
767 /**
768  * fdt_supernode_atdepth_offset - find a specific ancestor of a node
769  * @fdt: pointer to the device tree blob
770  * @nodeoffset: offset of the node whose parent to find
771  * @supernodedepth: depth of the ancestor to find
772  * @nodedepth: pointer to an integer variable (will be overwritten) or NULL
773  *
774  * fdt_supernode_atdepth_offset() finds an ancestor of the given node
775  * at a specific depth from the root (where the root itself has depth
776  * 0, its immediate subnodes depth 1 and so forth).  So
777  *	fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, NULL);
778  * will always return 0, the offset of the root node.  If the node at
779  * nodeoffset has depth D, then:
780  *	fdt_supernode_atdepth_offset(fdt, nodeoffset, D, NULL);
781  * will return nodeoffset itself.
782  *
783  * NOTE: This function is expensive, as it must scan the device tree
784  * structure from the start to nodeoffset.
785  *
786  * returns:
787  *	structure block offset of the node at node offset's ancestor
788  *		of depth supernodedepth (>=0), on success
789  *	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
790  *	-FDT_ERR_NOTFOUND, supernodedepth was greater than the depth of
791  *		nodeoffset
792  *	-FDT_ERR_BADMAGIC,
793  *	-FDT_ERR_BADVERSION,
794  *	-FDT_ERR_BADSTATE,
795  *	-FDT_ERR_BADSTRUCTURE, standard meanings
796  */
797 int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
798 				 int supernodedepth, int *nodedepth);
799 
800 /**
801  * fdt_node_depth - find the depth of a given node
802  * @fdt: pointer to the device tree blob
803  * @nodeoffset: offset of the node whose parent to find
804  *
805  * fdt_node_depth() finds the depth of a given node.  The root node
806  * has depth 0, its immediate subnodes depth 1 and so forth.
807  *
808  * NOTE: This function is expensive, as it must scan the device tree
809  * structure from the start to nodeoffset.
810  *
811  * returns:
812  *	depth of the node at nodeoffset (>=0), on success
813  *	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
814  *	-FDT_ERR_BADMAGIC,
815  *	-FDT_ERR_BADVERSION,
816  *	-FDT_ERR_BADSTATE,
817  *	-FDT_ERR_BADSTRUCTURE, standard meanings
818  */
819 int fdt_node_depth(const void *fdt, int nodeoffset);
820 
821 /**
822  * fdt_parent_offset - find the parent of a given node
823  * @fdt: pointer to the device tree blob
824  * @nodeoffset: offset of the node whose parent to find
825  *
826  * fdt_parent_offset() locates the parent node of a given node (that
827  * is, it finds the offset of the node which contains the node at
828  * nodeoffset as a subnode).
829  *
830  * NOTE: This function is expensive, as it must scan the device tree
831  * structure from the start to nodeoffset, *twice*.
832  *
833  * returns:
834  *	structure block offset of the parent of the node at nodeoffset
835  *		(>=0), on success
836  *	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
837  *	-FDT_ERR_BADMAGIC,
838  *	-FDT_ERR_BADVERSION,
839  *	-FDT_ERR_BADSTATE,
840  *	-FDT_ERR_BADSTRUCTURE, standard meanings
841  */
842 int fdt_parent_offset(const void *fdt, int nodeoffset);
843 
844 /**
845  * fdt_node_offset_by_prop_value - find nodes with a given property value
846  * @fdt: pointer to the device tree blob
847  * @startoffset: only find nodes after this offset
848  * @propname: property name to check
849  * @propval: property value to search for
850  * @proplen: length of the value in propval
851  *
852  * fdt_node_offset_by_prop_value() returns the offset of the first
853  * node after startoffset, which has a property named propname whose
854  * value is of length proplen and has value equal to propval; or if
855  * startoffset is -1, the very first such node in the tree.
856  *
857  * To iterate through all nodes matching the criterion, the following
858  * idiom can be used:
859  *	offset = fdt_node_offset_by_prop_value(fdt, -1, propname,
860  *					       propval, proplen);
861  *	while (offset != -FDT_ERR_NOTFOUND) {
862  *		// other code here
863  *		offset = fdt_node_offset_by_prop_value(fdt, offset, propname,
864  *						       propval, proplen);
865  *	}
866  *
867  * Note the -1 in the first call to the function, if 0 is used here
868  * instead, the function will never locate the root node, even if it
869  * matches the criterion.
870  *
871  * returns:
872  *	structure block offset of the located node (>= 0, >startoffset),
873  *		 on success
874  *	-FDT_ERR_NOTFOUND, no node matching the criterion exists in the
875  *		tree after startoffset
876  *	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
877  *	-FDT_ERR_BADMAGIC,
878  *	-FDT_ERR_BADVERSION,
879  *	-FDT_ERR_BADSTATE,
880  *	-FDT_ERR_BADSTRUCTURE, standard meanings
881  */
882 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
883 				  const char *propname,
884 				  const void *propval, int proplen);
885 
886 /**
887  * fdt_node_offset_by_phandle - find the node with a given phandle
888  * @fdt: pointer to the device tree blob
889  * @phandle: phandle value
890  *
891  * fdt_node_offset_by_phandle() returns the offset of the node
892  * which has the given phandle value.  If there is more than one node
893  * in the tree with the given phandle (an invalid tree), results are
894  * undefined.
895  *
896  * returns:
897  *	structure block offset of the located node (>= 0), on success
898  *	-FDT_ERR_NOTFOUND, no node with that phandle exists
899  *	-FDT_ERR_BADPHANDLE, given phandle value was invalid (0 or -1)
900  *	-FDT_ERR_BADMAGIC,
901  *	-FDT_ERR_BADVERSION,
902  *	-FDT_ERR_BADSTATE,
903  *	-FDT_ERR_BADSTRUCTURE, standard meanings
904  */
905 int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle);
906 
907 /**
908  * fdt_node_check_compatible: check a node's compatible property
909  * @fdt: pointer to the device tree blob
910  * @nodeoffset: offset of a tree node
911  * @compatible: string to match against
912  *
913  *
914  * fdt_node_check_compatible() returns 0 if the given node contains a
915  * 'compatible' property with the given string as one of its elements,
916  * it returns non-zero otherwise, or on error.
917  *
918  * returns:
919  *	0, if the node has a 'compatible' property listing the given string
920  *	1, if the node has a 'compatible' property, but it does not list
921  *		the given string
922  *	-FDT_ERR_NOTFOUND, if the given node has no 'compatible' property
923  *	-FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag
924  *	-FDT_ERR_BADMAGIC,
925  *	-FDT_ERR_BADVERSION,
926  *	-FDT_ERR_BADSTATE,
927  *	-FDT_ERR_BADSTRUCTURE, standard meanings
928  */
929 int fdt_node_check_compatible(const void *fdt, int nodeoffset,
930 			      const char *compatible);
931 
932 /**
933  * fdt_node_offset_by_compatible - find nodes with a given 'compatible' value
934  * @fdt: pointer to the device tree blob
935  * @startoffset: only find nodes after this offset
936  * @compatible: 'compatible' string to match against
937  *
938  * fdt_node_offset_by_compatible() returns the offset of the first
939  * node after startoffset, which has a 'compatible' property which
940  * lists the given compatible string; or if startoffset is -1, the
941  * very first such node in the tree.
942  *
943  * To iterate through all nodes matching the criterion, the following
944  * idiom can be used:
945  *	offset = fdt_node_offset_by_compatible(fdt, -1, compatible);
946  *	while (offset != -FDT_ERR_NOTFOUND) {
947  *		// other code here
948  *		offset = fdt_node_offset_by_compatible(fdt, offset, compatible);
949  *	}
950  *
951  * Note the -1 in the first call to the function, if 0 is used here
952  * instead, the function will never locate the root node, even if it
953  * matches the criterion.
954  *
955  * returns:
956  *	structure block offset of the located node (>= 0, >startoffset),
957  *		 on success
958  *	-FDT_ERR_NOTFOUND, no node matching the criterion exists in the
959  *		tree after startoffset
960  *	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
961  *	-FDT_ERR_BADMAGIC,
962  *	-FDT_ERR_BADVERSION,
963  *	-FDT_ERR_BADSTATE,
964  *	-FDT_ERR_BADSTRUCTURE, standard meanings
965  */
966 int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
967 				  const char *compatible);
968 
969 /**
970  * fdt_stringlist_contains - check a string list property for a string
971  * @strlist: Property containing a list of strings to check
972  * @listlen: Length of property
973  * @str: String to search for
974  *
975  * This is a utility function provided for convenience. The list contains
976  * one or more strings, each terminated by \0, as is found in a device tree
977  * "compatible" property.
978  *
979  * @return: 1 if the string is found in the list, 0 not found, or invalid list
980  */
981 int fdt_stringlist_contains(const char *strlist, int listlen, const char *str);
982 
983 /**
984  * fdt_stringlist_count - count the number of strings in a string list
985  * @fdt: pointer to the device tree blob
986  * @nodeoffset: offset of a tree node
987  * @property: name of the property containing the string list
988  * @return:
989  *   the number of strings in the given property
990  *   -FDT_ERR_BADVALUE if the property value is not NUL-terminated
991  *   -FDT_ERR_NOTFOUND if the property does not exist
992  */
993 int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property);
994 
995 /**
996  * fdt_stringlist_search - find a string in a string list and return its index
997  * @fdt: pointer to the device tree blob
998  * @nodeoffset: offset of a tree node
999  * @property: name of the property containing the string list
1000  * @string: string to look up in the string list
1001  *
1002  * Note that it is possible for this function to succeed on property values
1003  * that are not NUL-terminated. That's because the function will stop after
1004  * finding the first occurrence of @string. This can for example happen with
1005  * small-valued cell properties, such as #address-cells, when searching for
1006  * the empty string.
1007  *
1008  * @return:
1009  *   the index of the string in the list of strings
1010  *   -FDT_ERR_BADVALUE if the property value is not NUL-terminated
1011  *   -FDT_ERR_NOTFOUND if the property does not exist or does not contain
1012  *                     the given string
1013  */
1014 int fdt_stringlist_search(const void *fdt, int nodeoffset, const char *property,
1015 			  const char *string);
1016 
1017 /**
1018  * fdt_stringlist_get() - obtain the string at a given index in a string list
1019  * @fdt: pointer to the device tree blob
1020  * @nodeoffset: offset of a tree node
1021  * @property: name of the property containing the string list
1022  * @index: index of the string to return
1023  * @lenp: return location for the string length or an error code on failure
1024  *
1025  * Note that this will successfully extract strings from properties with
1026  * non-NUL-terminated values. For example on small-valued cell properties
1027  * this function will return the empty string.
1028  *
1029  * If non-NULL, the length of the string (on success) or a negative error-code
1030  * (on failure) will be stored in the integer pointer to by lenp.
1031  *
1032  * @return:
1033  *   A pointer to the string at the given index in the string list or NULL on
1034  *   failure. On success the length of the string will be stored in the memory
1035  *   location pointed to by the lenp parameter, if non-NULL. On failure one of
1036  *   the following negative error codes will be returned in the lenp parameter
1037  *   (if non-NULL):
1038  *     -FDT_ERR_BADVALUE if the property value is not NUL-terminated
1039  *     -FDT_ERR_NOTFOUND if the property does not exist
1040  */
1041 const char *fdt_stringlist_get(const void *fdt, int nodeoffset,
1042 			       const char *property, int index,
1043 			       int *lenp);
1044 
1045 /**********************************************************************/
1046 /* Read-only functions (addressing related)                           */
1047 /**********************************************************************/
1048 
1049 /**
1050  * FDT_MAX_NCELLS - maximum value for #address-cells and #size-cells
1051  *
1052  * This is the maximum value for #address-cells, #size-cells and
1053  * similar properties that will be processed by libfdt.  IEE1275
1054  * requires that OF implementations handle values up to 4.
1055  * Implementations may support larger values, but in practice higher
1056  * values aren't used.
1057  */
1058 #define FDT_MAX_NCELLS		4
1059 
1060 /**
1061  * fdt_address_cells - retrieve address size for a bus represented in the tree
1062  * @fdt: pointer to the device tree blob
1063  * @nodeoffset: offset of the node to find the address size for
1064  *
1065  * When the node has a valid #address-cells property, returns its value.
1066  *
1067  * returns:
1068  *	0 <= n < FDT_MAX_NCELLS, on success
1069  *      2, if the node has no #address-cells property
1070  *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
1071  *		#address-cells property
1072  *	-FDT_ERR_BADMAGIC,
1073  *	-FDT_ERR_BADVERSION,
1074  *	-FDT_ERR_BADSTATE,
1075  *	-FDT_ERR_BADSTRUCTURE,
1076  *	-FDT_ERR_TRUNCATED, standard meanings
1077  */
1078 int fdt_address_cells(const void *fdt, int nodeoffset);
1079 
1080 /**
1081  * fdt_size_cells - retrieve address range size for a bus represented in the
1082  *                  tree
1083  * @fdt: pointer to the device tree blob
1084  * @nodeoffset: offset of the node to find the address range size for
1085  *
1086  * When the node has a valid #size-cells property, returns its value.
1087  *
1088  * returns:
1089  *	0 <= n < FDT_MAX_NCELLS, on success
1090  *      2, if the node has no #address-cells property
1091  *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
1092  *		#size-cells property
1093  *	-FDT_ERR_BADMAGIC,
1094  *	-FDT_ERR_BADVERSION,
1095  *	-FDT_ERR_BADSTATE,
1096  *	-FDT_ERR_BADSTRUCTURE,
1097  *	-FDT_ERR_TRUNCATED, standard meanings
1098  */
1099 int fdt_size_cells(const void *fdt, int nodeoffset);
1100 
1101 
1102 /**********************************************************************/
1103 /* Write-in-place functions                                           */
1104 /**********************************************************************/
1105 
1106 /**
1107  * fdt_setprop_inplace_namelen_partial - change a property's value,
1108  *                                       but not its size
1109  * @fdt: pointer to the device tree blob
1110  * @nodeoffset: offset of the node whose property to change
1111  * @name: name of the property to change
1112  * @namelen: number of characters of name to consider
1113  * @idx: index of the property to change in the array
1114  * @val: pointer to data to replace the property value with
1115  * @len: length of the property value
1116  *
1117  * Identical to fdt_setprop_inplace(), but modifies the given property
1118  * starting from the given index, and using only the first characters
1119  * of the name. It is useful when you want to manipulate only one value of
1120  * an array and you have a string that doesn't end with \0.
1121  */
1122 #ifndef SWIG /* Not available in Python */
1123 int fdt_setprop_inplace_namelen_partial(void *fdt, int nodeoffset,
1124 					const char *name, int namelen,
1125 					uint32_t idx, const void *val,
1126 					int len);
1127 #endif
1128 
1129 /**
1130  * fdt_setprop_inplace - change a property's value, but not its size
1131  * @fdt: pointer to the device tree blob
1132  * @nodeoffset: offset of the node whose property to change
1133  * @name: name of the property to change
1134  * @val: pointer to data to replace the property value with
1135  * @len: length of the property value
1136  *
1137  * fdt_setprop_inplace() replaces the value of a given property with
1138  * the data in val, of length len.  This function cannot change the
1139  * size of a property, and so will only work if len is equal to the
1140  * current length of the property.
1141  *
1142  * This function will alter only the bytes in the blob which contain
1143  * the given property value, and will not alter or move any other part
1144  * of the tree.
1145  *
1146  * returns:
1147  *	0, on success
1148  *	-FDT_ERR_NOSPACE, if len is not equal to the property's current length
1149  *	-FDT_ERR_NOTFOUND, node does not have the named property
1150  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1151  *	-FDT_ERR_BADMAGIC,
1152  *	-FDT_ERR_BADVERSION,
1153  *	-FDT_ERR_BADSTATE,
1154  *	-FDT_ERR_BADSTRUCTURE,
1155  *	-FDT_ERR_TRUNCATED, standard meanings
1156  */
1157 #ifndef SWIG /* Not available in Python */
1158 int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
1159 			const void *val, int len);
1160 #endif
1161 
1162 /**
1163  * fdt_setprop_inplace_u32 - change the value of a 32-bit integer property
1164  * @fdt: pointer to the device tree blob
1165  * @nodeoffset: offset of the node whose property to change
1166  * @name: name of the property to change
1167  * @val: 32-bit integer value to replace the property with
1168  *
1169  * fdt_setprop_inplace_u32() replaces the value of a given property
1170  * with the 32-bit integer value in val, converting val to big-endian
1171  * if necessary.  This function cannot change the size of a property,
1172  * and so will only work if the property already exists and has length
1173  * 4.
1174  *
1175  * This function will alter only the bytes in the blob which contain
1176  * the given property value, and will not alter or move any other part
1177  * of the tree.
1178  *
1179  * returns:
1180  *	0, on success
1181  *	-FDT_ERR_NOSPACE, if the property's length is not equal to 4
1182  *	-FDT_ERR_NOTFOUND, node does not have the named property
1183  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1184  *	-FDT_ERR_BADMAGIC,
1185  *	-FDT_ERR_BADVERSION,
1186  *	-FDT_ERR_BADSTATE,
1187  *	-FDT_ERR_BADSTRUCTURE,
1188  *	-FDT_ERR_TRUNCATED, standard meanings
1189  */
1190 static inline int fdt_setprop_inplace_u32(void *fdt, int nodeoffset,
1191 					  const char *name, uint32_t val)
1192 {
1193 	fdt32_t tmp = cpu_to_fdt32(val);
1194 	return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1195 }
1196 
1197 /**
1198  * fdt_setprop_inplace_u64 - change the value of a 64-bit integer property
1199  * @fdt: pointer to the device tree blob
1200  * @nodeoffset: offset of the node whose property to change
1201  * @name: name of the property to change
1202  * @val: 64-bit integer value to replace the property with
1203  *
1204  * fdt_setprop_inplace_u64() replaces the value of a given property
1205  * with the 64-bit integer value in val, converting val to big-endian
1206  * if necessary.  This function cannot change the size of a property,
1207  * and so will only work if the property already exists and has length
1208  * 8.
1209  *
1210  * This function will alter only the bytes in the blob which contain
1211  * the given property value, and will not alter or move any other part
1212  * of the tree.
1213  *
1214  * returns:
1215  *	0, on success
1216  *	-FDT_ERR_NOSPACE, if the property's length is not equal to 8
1217  *	-FDT_ERR_NOTFOUND, node does not have the named property
1218  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1219  *	-FDT_ERR_BADMAGIC,
1220  *	-FDT_ERR_BADVERSION,
1221  *	-FDT_ERR_BADSTATE,
1222  *	-FDT_ERR_BADSTRUCTURE,
1223  *	-FDT_ERR_TRUNCATED, standard meanings
1224  */
1225 static inline int fdt_setprop_inplace_u64(void *fdt, int nodeoffset,
1226 					  const char *name, uint64_t val)
1227 {
1228 	fdt64_t tmp = cpu_to_fdt64(val);
1229 	return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1230 }
1231 
1232 /**
1233  * fdt_setprop_inplace_cell - change the value of a single-cell property
1234  *
1235  * This is an alternative name for fdt_setprop_inplace_u32()
1236  */
1237 static inline int fdt_setprop_inplace_cell(void *fdt, int nodeoffset,
1238 					   const char *name, uint32_t val)
1239 {
1240 	return fdt_setprop_inplace_u32(fdt, nodeoffset, name, val);
1241 }
1242 
1243 /**
1244  * fdt_nop_property - replace a property with nop tags
1245  * @fdt: pointer to the device tree blob
1246  * @nodeoffset: offset of the node whose property to nop
1247  * @name: name of the property to nop
1248  *
1249  * fdt_nop_property() will replace a given property's representation
1250  * in the blob with FDT_NOP tags, effectively removing it from the
1251  * tree.
1252  *
1253  * This function will alter only the bytes in the blob which contain
1254  * the property, and will not alter or move any other part of the
1255  * tree.
1256  *
1257  * returns:
1258  *	0, on success
1259  *	-FDT_ERR_NOTFOUND, node does not have the named property
1260  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1261  *	-FDT_ERR_BADMAGIC,
1262  *	-FDT_ERR_BADVERSION,
1263  *	-FDT_ERR_BADSTATE,
1264  *	-FDT_ERR_BADSTRUCTURE,
1265  *	-FDT_ERR_TRUNCATED, standard meanings
1266  */
1267 int fdt_nop_property(void *fdt, int nodeoffset, const char *name);
1268 
1269 /**
1270  * fdt_nop_node - replace a node (subtree) with nop tags
1271  * @fdt: pointer to the device tree blob
1272  * @nodeoffset: offset of the node to nop
1273  *
1274  * fdt_nop_node() will replace a given node's representation in the
1275  * blob, including all its subnodes, if any, with FDT_NOP tags,
1276  * effectively removing it from the tree.
1277  *
1278  * This function will alter only the bytes in the blob which contain
1279  * the node and its properties and subnodes, and will not alter or
1280  * move any other part of the tree.
1281  *
1282  * returns:
1283  *	0, on success
1284  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1285  *	-FDT_ERR_BADMAGIC,
1286  *	-FDT_ERR_BADVERSION,
1287  *	-FDT_ERR_BADSTATE,
1288  *	-FDT_ERR_BADSTRUCTURE,
1289  *	-FDT_ERR_TRUNCATED, standard meanings
1290  */
1291 int fdt_nop_node(void *fdt, int nodeoffset);
1292 
1293 /**********************************************************************/
1294 /* Sequential write functions                                         */
1295 /**********************************************************************/
1296 
1297 int fdt_create(void *buf, int bufsize);
1298 int fdt_resize(void *fdt, void *buf, int bufsize);
1299 int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size);
1300 int fdt_finish_reservemap(void *fdt);
1301 int fdt_begin_node(void *fdt, const char *name);
1302 int fdt_property(void *fdt, const char *name, const void *val, int len);
1303 static inline int fdt_property_u32(void *fdt, const char *name, uint32_t val)
1304 {
1305 	fdt32_t tmp = cpu_to_fdt32(val);
1306 	return fdt_property(fdt, name, &tmp, sizeof(tmp));
1307 }
1308 static inline int fdt_property_u64(void *fdt, const char *name, uint64_t val)
1309 {
1310 	fdt64_t tmp = cpu_to_fdt64(val);
1311 	return fdt_property(fdt, name, &tmp, sizeof(tmp));
1312 }
1313 static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val)
1314 {
1315 	return fdt_property_u32(fdt, name, val);
1316 }
1317 
1318 /**
1319  * fdt_property_placeholder - add a new property and return a ptr to its value
1320  *
1321  * @fdt: pointer to the device tree blob
1322  * @name: name of property to add
1323  * @len: length of property value in bytes
1324  * @valp: returns a pointer to where where the value should be placed
1325  *
1326  * returns:
1327  *	0, on success
1328  *	-FDT_ERR_BADMAGIC,
1329  *	-FDT_ERR_NOSPACE, standard meanings
1330  */
1331 int fdt_property_placeholder(void *fdt, const char *name, int len, void **valp);
1332 
1333 #define fdt_property_string(fdt, name, str) \
1334 	fdt_property(fdt, name, str, strlen(str)+1)
1335 int fdt_end_node(void *fdt);
1336 int fdt_finish(void *fdt);
1337 
1338 /**********************************************************************/
1339 /* Read-write functions                                               */
1340 /**********************************************************************/
1341 
1342 int fdt_create_empty_tree(void *buf, int bufsize);
1343 int fdt_open_into(const void *fdt, void *buf, int bufsize);
1344 int fdt_pack(void *fdt);
1345 
1346 /**
1347  * fdt_add_mem_rsv - add one memory reserve map entry
1348  * @fdt: pointer to the device tree blob
1349  * @address, @size: 64-bit values (native endian)
1350  *
1351  * Adds a reserve map entry to the given blob reserving a region at
1352  * address address of length size.
1353  *
1354  * This function will insert data into the reserve map and will
1355  * therefore change the indexes of some entries in the table.
1356  *
1357  * returns:
1358  *	0, on success
1359  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1360  *		contain the new reservation entry
1361  *	-FDT_ERR_BADMAGIC,
1362  *	-FDT_ERR_BADVERSION,
1363  *	-FDT_ERR_BADSTATE,
1364  *	-FDT_ERR_BADSTRUCTURE,
1365  *	-FDT_ERR_BADLAYOUT,
1366  *	-FDT_ERR_TRUNCATED, standard meanings
1367  */
1368 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size);
1369 
1370 /**
1371  * fdt_del_mem_rsv - remove a memory reserve map entry
1372  * @fdt: pointer to the device tree blob
1373  * @n: entry to remove
1374  *
1375  * fdt_del_mem_rsv() removes the n-th memory reserve map entry from
1376  * the blob.
1377  *
1378  * This function will delete data from the reservation table and will
1379  * therefore change the indexes of some entries in the table.
1380  *
1381  * returns:
1382  *	0, on success
1383  *	-FDT_ERR_NOTFOUND, there is no entry of the given index (i.e. there
1384  *		are less than n+1 reserve map entries)
1385  *	-FDT_ERR_BADMAGIC,
1386  *	-FDT_ERR_BADVERSION,
1387  *	-FDT_ERR_BADSTATE,
1388  *	-FDT_ERR_BADSTRUCTURE,
1389  *	-FDT_ERR_BADLAYOUT,
1390  *	-FDT_ERR_TRUNCATED, standard meanings
1391  */
1392 int fdt_del_mem_rsv(void *fdt, int n);
1393 
1394 /**
1395  * fdt_set_name - change the name of a given node
1396  * @fdt: pointer to the device tree blob
1397  * @nodeoffset: structure block offset of a node
1398  * @name: name to give the node
1399  *
1400  * fdt_set_name() replaces the name (including unit address, if any)
1401  * of the given node with the given string.  NOTE: this function can't
1402  * efficiently check if the new name is unique amongst the given
1403  * node's siblings; results are undefined if this function is invoked
1404  * with a name equal to one of the given node's siblings.
1405  *
1406  * This function may insert or delete data from the blob, and will
1407  * therefore change the offsets of some existing nodes.
1408  *
1409  * returns:
1410  *	0, on success
1411  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob
1412  *		to contain the new name
1413  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1414  *	-FDT_ERR_BADMAGIC,
1415  *	-FDT_ERR_BADVERSION,
1416  *	-FDT_ERR_BADSTATE, standard meanings
1417  */
1418 int fdt_set_name(void *fdt, int nodeoffset, const char *name);
1419 
1420 /**
1421  * fdt_setprop - create or change a property
1422  * @fdt: pointer to the device tree blob
1423  * @nodeoffset: offset of the node whose property to change
1424  * @name: name of the property to change
1425  * @val: pointer to data to set the property value to
1426  * @len: length of the property value
1427  *
1428  * fdt_setprop() sets the value of the named property in the given
1429  * node to the given value and length, creating the property if it
1430  * does not already exist.
1431  *
1432  * This function may insert or delete data from the blob, and will
1433  * therefore change the offsets of some existing nodes.
1434  *
1435  * returns:
1436  *	0, on success
1437  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1438  *		contain the new property value
1439  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1440  *	-FDT_ERR_BADLAYOUT,
1441  *	-FDT_ERR_BADMAGIC,
1442  *	-FDT_ERR_BADVERSION,
1443  *	-FDT_ERR_BADSTATE,
1444  *	-FDT_ERR_BADSTRUCTURE,
1445  *	-FDT_ERR_BADLAYOUT,
1446  *	-FDT_ERR_TRUNCATED, standard meanings
1447  */
1448 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
1449 		const void *val, int len);
1450 
1451 /**
1452  * fdt_setprop _placeholder - allocate space for a property
1453  * @fdt: pointer to the device tree blob
1454  * @nodeoffset: offset of the node whose property to change
1455  * @name: name of the property to change
1456  * @len: length of the property value
1457  * @prop_data: return pointer to property data
1458  *
1459  * fdt_setprop_placeholer() allocates the named property in the given node.
1460  * If the property exists it is resized. In either case a pointer to the
1461  * property data is returned.
1462  *
1463  * This function may insert or delete data from the blob, and will
1464  * therefore change the offsets of some existing nodes.
1465  *
1466  * returns:
1467  *	0, on success
1468  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1469  *		contain the new property value
1470  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1471  *	-FDT_ERR_BADLAYOUT,
1472  *	-FDT_ERR_BADMAGIC,
1473  *	-FDT_ERR_BADVERSION,
1474  *	-FDT_ERR_BADSTATE,
1475  *	-FDT_ERR_BADSTRUCTURE,
1476  *	-FDT_ERR_BADLAYOUT,
1477  *	-FDT_ERR_TRUNCATED, standard meanings
1478  */
1479 int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name,
1480 			    int len, void **prop_data);
1481 
1482 /**
1483  * fdt_setprop_u32 - set a property to a 32-bit integer
1484  * @fdt: pointer to the device tree blob
1485  * @nodeoffset: offset of the node whose property to change
1486  * @name: name of the property to change
1487  * @val: 32-bit integer value for the property (native endian)
1488  *
1489  * fdt_setprop_u32() sets the value of the named property in the given
1490  * node to the given 32-bit integer value (converting to big-endian if
1491  * necessary), or creates a new property with that value if it does
1492  * not already exist.
1493  *
1494  * This function may insert or delete data from the blob, and will
1495  * therefore change the offsets of some existing nodes.
1496  *
1497  * returns:
1498  *	0, on success
1499  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1500  *		contain the new property value
1501  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1502  *	-FDT_ERR_BADLAYOUT,
1503  *	-FDT_ERR_BADMAGIC,
1504  *	-FDT_ERR_BADVERSION,
1505  *	-FDT_ERR_BADSTATE,
1506  *	-FDT_ERR_BADSTRUCTURE,
1507  *	-FDT_ERR_BADLAYOUT,
1508  *	-FDT_ERR_TRUNCATED, standard meanings
1509  */
1510 static inline int fdt_setprop_u32(void *fdt, int nodeoffset, const char *name,
1511 				  uint32_t val)
1512 {
1513 	fdt32_t tmp = cpu_to_fdt32(val);
1514 	return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1515 }
1516 
1517 /**
1518  * fdt_setprop_u64 - set a property to a 64-bit integer
1519  * @fdt: pointer to the device tree blob
1520  * @nodeoffset: offset of the node whose property to change
1521  * @name: name of the property to change
1522  * @val: 64-bit integer value for the property (native endian)
1523  *
1524  * fdt_setprop_u64() sets the value of the named property in the given
1525  * node to the given 64-bit integer value (converting to big-endian if
1526  * necessary), or creates a new property with that value if it does
1527  * not already exist.
1528  *
1529  * This function may insert or delete data from the blob, and will
1530  * therefore change the offsets of some existing nodes.
1531  *
1532  * returns:
1533  *	0, on success
1534  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1535  *		contain the new property value
1536  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1537  *	-FDT_ERR_BADLAYOUT,
1538  *	-FDT_ERR_BADMAGIC,
1539  *	-FDT_ERR_BADVERSION,
1540  *	-FDT_ERR_BADSTATE,
1541  *	-FDT_ERR_BADSTRUCTURE,
1542  *	-FDT_ERR_BADLAYOUT,
1543  *	-FDT_ERR_TRUNCATED, standard meanings
1544  */
1545 static inline int fdt_setprop_u64(void *fdt, int nodeoffset, const char *name,
1546 				  uint64_t val)
1547 {
1548 	fdt64_t tmp = cpu_to_fdt64(val);
1549 	return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1550 }
1551 
1552 /**
1553  * fdt_setprop_cell - set a property to a single cell value
1554  *
1555  * This is an alternative name for fdt_setprop_u32()
1556  */
1557 static inline int fdt_setprop_cell(void *fdt, int nodeoffset, const char *name,
1558 				   uint32_t val)
1559 {
1560 	return fdt_setprop_u32(fdt, nodeoffset, name, val);
1561 }
1562 
1563 /**
1564  * fdt_setprop_string - set a property to a string value
1565  * @fdt: pointer to the device tree blob
1566  * @nodeoffset: offset of the node whose property to change
1567  * @name: name of the property to change
1568  * @str: string value for the property
1569  *
1570  * fdt_setprop_string() sets the value of the named property in the
1571  * given node to the given string value (using the length of the
1572  * string to determine the new length of the property), or creates a
1573  * new property with that value if it does not already exist.
1574  *
1575  * This function may insert or delete data from the blob, and will
1576  * therefore change the offsets of some existing nodes.
1577  *
1578  * returns:
1579  *	0, on success
1580  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1581  *		contain the new property value
1582  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1583  *	-FDT_ERR_BADLAYOUT,
1584  *	-FDT_ERR_BADMAGIC,
1585  *	-FDT_ERR_BADVERSION,
1586  *	-FDT_ERR_BADSTATE,
1587  *	-FDT_ERR_BADSTRUCTURE,
1588  *	-FDT_ERR_BADLAYOUT,
1589  *	-FDT_ERR_TRUNCATED, standard meanings
1590  */
1591 #define fdt_setprop_string(fdt, nodeoffset, name, str) \
1592 	fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1593 
1594 
1595 /**
1596  * fdt_setprop_empty - set a property to an empty value
1597  * @fdt: pointer to the device tree blob
1598  * @nodeoffset: offset of the node whose property to change
1599  * @name: name of the property to change
1600  *
1601  * fdt_setprop_empty() sets the value of the named property in the
1602  * given node to an empty (zero length) value, or creates a new empty
1603  * property if it does not already exist.
1604  *
1605  * This function may insert or delete data from the blob, and will
1606  * therefore change the offsets of some existing nodes.
1607  *
1608  * returns:
1609  *	0, on success
1610  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1611  *		contain the new property value
1612  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1613  *	-FDT_ERR_BADLAYOUT,
1614  *	-FDT_ERR_BADMAGIC,
1615  *	-FDT_ERR_BADVERSION,
1616  *	-FDT_ERR_BADSTATE,
1617  *	-FDT_ERR_BADSTRUCTURE,
1618  *	-FDT_ERR_BADLAYOUT,
1619  *	-FDT_ERR_TRUNCATED, standard meanings
1620  */
1621 #define fdt_setprop_empty(fdt, nodeoffset, name) \
1622 	fdt_setprop((fdt), (nodeoffset), (name), NULL, 0)
1623 
1624 /**
1625  * fdt_appendprop - append to or create a property
1626  * @fdt: pointer to the device tree blob
1627  * @nodeoffset: offset of the node whose property to change
1628  * @name: name of the property to append to
1629  * @val: pointer to data to append to the property value
1630  * @len: length of the data to append to the property value
1631  *
1632  * fdt_appendprop() appends the value to the named property in the
1633  * given node, creating the property if it does not already exist.
1634  *
1635  * This function may insert data into the blob, and will therefore
1636  * change the offsets of some existing nodes.
1637  *
1638  * returns:
1639  *	0, on success
1640  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1641  *		contain the new property value
1642  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1643  *	-FDT_ERR_BADLAYOUT,
1644  *	-FDT_ERR_BADMAGIC,
1645  *	-FDT_ERR_BADVERSION,
1646  *	-FDT_ERR_BADSTATE,
1647  *	-FDT_ERR_BADSTRUCTURE,
1648  *	-FDT_ERR_BADLAYOUT,
1649  *	-FDT_ERR_TRUNCATED, standard meanings
1650  */
1651 int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
1652 		   const void *val, int len);
1653 
1654 /**
1655  * fdt_appendprop_u32 - append a 32-bit integer value to a property
1656  * @fdt: pointer to the device tree blob
1657  * @nodeoffset: offset of the node whose property to change
1658  * @name: name of the property to change
1659  * @val: 32-bit integer value to append to the property (native endian)
1660  *
1661  * fdt_appendprop_u32() appends the given 32-bit integer value
1662  * (converting to big-endian if necessary) to the value of the named
1663  * property in the given node, or creates a new property with that
1664  * value if it does not already exist.
1665  *
1666  * This function may insert data into the blob, and will therefore
1667  * change the offsets of some existing nodes.
1668  *
1669  * returns:
1670  *	0, on success
1671  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1672  *		contain the new property value
1673  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1674  *	-FDT_ERR_BADLAYOUT,
1675  *	-FDT_ERR_BADMAGIC,
1676  *	-FDT_ERR_BADVERSION,
1677  *	-FDT_ERR_BADSTATE,
1678  *	-FDT_ERR_BADSTRUCTURE,
1679  *	-FDT_ERR_BADLAYOUT,
1680  *	-FDT_ERR_TRUNCATED, standard meanings
1681  */
1682 static inline int fdt_appendprop_u32(void *fdt, int nodeoffset,
1683 				     const char *name, uint32_t val)
1684 {
1685 	fdt32_t tmp = cpu_to_fdt32(val);
1686 	return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1687 }
1688 
1689 /**
1690  * fdt_appendprop_u64 - append a 64-bit integer value to a property
1691  * @fdt: pointer to the device tree blob
1692  * @nodeoffset: offset of the node whose property to change
1693  * @name: name of the property to change
1694  * @val: 64-bit integer value to append to the property (native endian)
1695  *
1696  * fdt_appendprop_u64() appends the given 64-bit integer value
1697  * (converting to big-endian if necessary) to the value of the named
1698  * property in the given node, or creates a new property with that
1699  * value if it does not already exist.
1700  *
1701  * This function may insert data into the blob, and will therefore
1702  * change the offsets of some existing nodes.
1703  *
1704  * returns:
1705  *	0, on success
1706  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1707  *		contain the new property value
1708  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1709  *	-FDT_ERR_BADLAYOUT,
1710  *	-FDT_ERR_BADMAGIC,
1711  *	-FDT_ERR_BADVERSION,
1712  *	-FDT_ERR_BADSTATE,
1713  *	-FDT_ERR_BADSTRUCTURE,
1714  *	-FDT_ERR_BADLAYOUT,
1715  *	-FDT_ERR_TRUNCATED, standard meanings
1716  */
1717 static inline int fdt_appendprop_u64(void *fdt, int nodeoffset,
1718 				     const char *name, uint64_t val)
1719 {
1720 	fdt64_t tmp = cpu_to_fdt64(val);
1721 	return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1722 }
1723 
1724 /**
1725  * fdt_appendprop_cell - append a single cell value to a property
1726  *
1727  * This is an alternative name for fdt_appendprop_u32()
1728  */
1729 static inline int fdt_appendprop_cell(void *fdt, int nodeoffset,
1730 				      const char *name, uint32_t val)
1731 {
1732 	return fdt_appendprop_u32(fdt, nodeoffset, name, val);
1733 }
1734 
1735 /**
1736  * fdt_appendprop_string - append a string to a property
1737  * @fdt: pointer to the device tree blob
1738  * @nodeoffset: offset of the node whose property to change
1739  * @name: name of the property to change
1740  * @str: string value to append to the property
1741  *
1742  * fdt_appendprop_string() appends the given string to the value of
1743  * the named property in the given node, or creates a new property
1744  * with that value if it does not already exist.
1745  *
1746  * This function may insert data into the blob, and will therefore
1747  * change the offsets of some existing nodes.
1748  *
1749  * returns:
1750  *	0, on success
1751  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1752  *		contain the new property value
1753  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1754  *	-FDT_ERR_BADLAYOUT,
1755  *	-FDT_ERR_BADMAGIC,
1756  *	-FDT_ERR_BADVERSION,
1757  *	-FDT_ERR_BADSTATE,
1758  *	-FDT_ERR_BADSTRUCTURE,
1759  *	-FDT_ERR_BADLAYOUT,
1760  *	-FDT_ERR_TRUNCATED, standard meanings
1761  */
1762 #define fdt_appendprop_string(fdt, nodeoffset, name, str) \
1763 	fdt_appendprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1764 
1765 /**
1766  * fdt_delprop - delete a property
1767  * @fdt: pointer to the device tree blob
1768  * @nodeoffset: offset of the node whose property to nop
1769  * @name: name of the property to nop
1770  *
1771  * fdt_del_property() will delete the given property.
1772  *
1773  * This function will delete data from the blob, and will therefore
1774  * change the offsets of some existing nodes.
1775  *
1776  * returns:
1777  *	0, on success
1778  *	-FDT_ERR_NOTFOUND, node does not have the named property
1779  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1780  *	-FDT_ERR_BADLAYOUT,
1781  *	-FDT_ERR_BADMAGIC,
1782  *	-FDT_ERR_BADVERSION,
1783  *	-FDT_ERR_BADSTATE,
1784  *	-FDT_ERR_BADSTRUCTURE,
1785  *	-FDT_ERR_TRUNCATED, standard meanings
1786  */
1787 int fdt_delprop(void *fdt, int nodeoffset, const char *name);
1788 
1789 /**
1790  * fdt_add_subnode_namelen - creates a new node based on substring
1791  * @fdt: pointer to the device tree blob
1792  * @parentoffset: structure block offset of a node
1793  * @name: name of the subnode to locate
1794  * @namelen: number of characters of name to consider
1795  *
1796  * Identical to fdt_add_subnode(), but use only the first namelen
1797  * characters of name as the name of the new node.  This is useful for
1798  * creating subnodes based on a portion of a larger string, such as a
1799  * full path.
1800  */
1801 #ifndef SWIG /* Not available in Python */
1802 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
1803 			    const char *name, int namelen);
1804 #endif
1805 
1806 /**
1807  * fdt_add_subnode - creates a new node
1808  * @fdt: pointer to the device tree blob
1809  * @parentoffset: structure block offset of a node
1810  * @name: name of the subnode to locate
1811  *
1812  * fdt_add_subnode() creates a new node as a subnode of the node at
1813  * structure block offset parentoffset, with the given name (which
1814  * should include the unit address, if any).
1815  *
1816  * This function will insert data into the blob, and will therefore
1817  * change the offsets of some existing nodes.
1818 
1819  * returns:
1820  *	structure block offset of the created nodeequested subnode (>=0), on
1821  *		success
1822  *	-FDT_ERR_NOTFOUND, if the requested subnode does not exist
1823  *	-FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE
1824  *		tag
1825  *	-FDT_ERR_EXISTS, if the node at parentoffset already has a subnode of
1826  *		the given name
1827  *	-FDT_ERR_NOSPACE, if there is insufficient free space in the
1828  *		blob to contain the new node
1829  *	-FDT_ERR_NOSPACE
1830  *	-FDT_ERR_BADLAYOUT
1831  *      -FDT_ERR_BADMAGIC,
1832  *	-FDT_ERR_BADVERSION,
1833  *	-FDT_ERR_BADSTATE,
1834  *	-FDT_ERR_BADSTRUCTURE,
1835  *	-FDT_ERR_TRUNCATED, standard meanings.
1836  */
1837 int fdt_add_subnode(void *fdt, int parentoffset, const char *name);
1838 
1839 /**
1840  * fdt_del_node - delete a node (subtree)
1841  * @fdt: pointer to the device tree blob
1842  * @nodeoffset: offset of the node to nop
1843  *
1844  * fdt_del_node() will remove the given node, including all its
1845  * subnodes if any, from the blob.
1846  *
1847  * This function will delete data from the blob, and will therefore
1848  * change the offsets of some existing nodes.
1849  *
1850  * returns:
1851  *	0, on success
1852  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1853  *	-FDT_ERR_BADLAYOUT,
1854  *	-FDT_ERR_BADMAGIC,
1855  *	-FDT_ERR_BADVERSION,
1856  *	-FDT_ERR_BADSTATE,
1857  *	-FDT_ERR_BADSTRUCTURE,
1858  *	-FDT_ERR_TRUNCATED, standard meanings
1859  */
1860 int fdt_del_node(void *fdt, int nodeoffset);
1861 
1862 /**
1863  * fdt_overlay_apply - Applies a DT overlay on a base DT
1864  * @fdt: pointer to the base device tree blob
1865  * @fdto: pointer to the device tree overlay blob
1866  *
1867  * fdt_overlay_apply() will apply the given device tree overlay on the
1868  * given base device tree.
1869  *
1870  * Expect the base device tree to be modified, even if the function
1871  * returns an error.
1872  *
1873  * returns:
1874  *	0, on success
1875  *	-FDT_ERR_NOSPACE, there's not enough space in the base device tree
1876  *	-FDT_ERR_NOTFOUND, the overlay points to some inexistant nodes or
1877  *		properties in the base DT
1878  *	-FDT_ERR_BADPHANDLE,
1879  *	-FDT_ERR_BADOVERLAY,
1880  *	-FDT_ERR_NOPHANDLES,
1881  *	-FDT_ERR_INTERNAL,
1882  *	-FDT_ERR_BADLAYOUT,
1883  *	-FDT_ERR_BADMAGIC,
1884  *	-FDT_ERR_BADOFFSET,
1885  *	-FDT_ERR_BADPATH,
1886  *	-FDT_ERR_BADVERSION,
1887  *	-FDT_ERR_BADSTRUCTURE,
1888  *	-FDT_ERR_BADSTATE,
1889  *	-FDT_ERR_TRUNCATED, standard meanings
1890  */
1891 int fdt_overlay_apply(void *fdt, void *fdto);
1892 
1893 /**********************************************************************/
1894 /* Debugging / informational functions                                */
1895 /**********************************************************************/
1896 
1897 const char *fdt_strerror(int errval);
1898 
1899 #endif /* _LIBFDT_H */
1900