xref: /openbmc/u-boot/scripts/dtc/libfdt/libfdt.h (revision e3396ffd)
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	0x02
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
fdt_offset_ptr_w(void * fdt,int offset,int checklen)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  * Note that this code only works on device tree versions >= 16. fdt_getprop()
531  * works on all versions.
532  *
533  * returns:
534  *	pointer to the structure representing the property
535  *		if lenp is non-NULL, *lenp contains the length of the property
536  *		value (>=0)
537  *	NULL, on error
538  *		if lenp is non-NULL, *lenp contains an error code (<0):
539  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
540  *		-FDT_ERR_BADMAGIC,
541  *		-FDT_ERR_BADVERSION,
542  *		-FDT_ERR_BADSTATE,
543  *		-FDT_ERR_BADSTRUCTURE,
544  *		-FDT_ERR_TRUNCATED, standard meanings
545  */
546 const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
547 						      int offset,
548 						      int *lenp);
549 
550 /**
551  * fdt_get_property_namelen - find a property based on substring
552  * @fdt: pointer to the device tree blob
553  * @nodeoffset: offset of the node whose property to find
554  * @name: name of the property to find
555  * @namelen: number of characters of name to consider
556  * @lenp: pointer to an integer variable (will be overwritten) or NULL
557  *
558  * Identical to fdt_get_property(), but only examine the first namelen
559  * characters of name for matching the property name.
560  */
561 #ifndef SWIG /* Not available in Python */
562 const struct fdt_property *fdt_get_property_namelen(const void *fdt,
563 						    int nodeoffset,
564 						    const char *name,
565 						    int namelen, int *lenp);
566 #endif
567 
568 /**
569  * fdt_get_property - find a given property in a given node
570  * @fdt: pointer to the device tree blob
571  * @nodeoffset: offset of the node whose property to find
572  * @name: name of the property to find
573  * @lenp: pointer to an integer variable (will be overwritten) or NULL
574  *
575  * fdt_get_property() retrieves a pointer to the fdt_property
576  * structure within the device tree blob corresponding to the property
577  * named 'name' of the node at offset nodeoffset.  If lenp is
578  * non-NULL, the length of the property value is also returned, in the
579  * integer pointed to by lenp.
580  *
581  * returns:
582  *	pointer to the structure representing the property
583  *		if lenp is non-NULL, *lenp contains the length of the property
584  *		value (>=0)
585  *	NULL, on error
586  *		if lenp is non-NULL, *lenp contains an error code (<0):
587  *		-FDT_ERR_NOTFOUND, node does not have named property
588  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE
589  *			tag
590  *		-FDT_ERR_BADMAGIC,
591  *		-FDT_ERR_BADVERSION,
592  *		-FDT_ERR_BADSTATE,
593  *		-FDT_ERR_BADSTRUCTURE,
594  *		-FDT_ERR_TRUNCATED, standard meanings
595  */
596 const struct fdt_property *fdt_get_property(const void *fdt, int nodeoffset,
597 					    const char *name, int *lenp);
fdt_get_property_w(void * fdt,int nodeoffset,const char * name,int * lenp)598 static inline struct fdt_property *fdt_get_property_w(void *fdt, int nodeoffset,
599 						      const char *name,
600 						      int *lenp)
601 {
602 	return (struct fdt_property *)(uintptr_t)
603 		fdt_get_property(fdt, nodeoffset, name, lenp);
604 }
605 
606 /**
607  * fdt_getprop_by_offset - retrieve the value of a property at a given offset
608  * @fdt: pointer to the device tree blob
609  * @ffset: offset of the property to read
610  * @namep: pointer to a string variable (will be overwritten) or NULL
611  * @lenp: pointer to an integer variable (will be overwritten) or NULL
612  *
613  * fdt_getprop_by_offset() retrieves a pointer to the value of the
614  * property at structure block offset 'offset' (this will be a pointer
615  * to within the device blob itself, not a copy of the value).  If
616  * lenp is non-NULL, the length of the property value is also
617  * returned, in the integer pointed to by lenp.  If namep is non-NULL,
618  * the property's namne will also be returned in the char * pointed to
619  * by namep (this will be a pointer to within the device tree's string
620  * block, not a new copy of the name).
621  *
622  * returns:
623  *	pointer to the property's value
624  *		if lenp is non-NULL, *lenp contains the length of the property
625  *		value (>=0)
626  *		if namep is non-NULL *namep contiains a pointer to the property
627  *		name.
628  *	NULL, on error
629  *		if lenp is non-NULL, *lenp contains an error code (<0):
630  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
631  *		-FDT_ERR_BADMAGIC,
632  *		-FDT_ERR_BADVERSION,
633  *		-FDT_ERR_BADSTATE,
634  *		-FDT_ERR_BADSTRUCTURE,
635  *		-FDT_ERR_TRUNCATED, standard meanings
636  */
637 #ifndef SWIG /* This function is not useful in Python */
638 const void *fdt_getprop_by_offset(const void *fdt, int offset,
639 				  const char **namep, int *lenp);
640 #endif
641 
642 /**
643  * fdt_getprop_namelen - get property value based on substring
644  * @fdt: pointer to the device tree blob
645  * @nodeoffset: offset of the node whose property to find
646  * @name: name of the property to find
647  * @namelen: number of characters of name to consider
648  * @lenp: pointer to an integer variable (will be overwritten) or NULL
649  *
650  * Identical to fdt_getprop(), but only examine the first namelen
651  * characters of name for matching the property name.
652  */
653 #ifndef SWIG /* Not available in Python */
654 const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
655 				const char *name, int namelen, int *lenp);
fdt_getprop_namelen_w(void * fdt,int nodeoffset,const char * name,int namelen,int * lenp)656 static inline void *fdt_getprop_namelen_w(void *fdt, int nodeoffset,
657 					  const char *name, int namelen,
658 					  int *lenp)
659 {
660 	return (void *)(uintptr_t)fdt_getprop_namelen(fdt, nodeoffset, name,
661 						      namelen, lenp);
662 }
663 #endif
664 
665 /**
666  * fdt_getprop - retrieve the value of a given property
667  * @fdt: pointer to the device tree blob
668  * @nodeoffset: offset of the node whose property to find
669  * @name: name of the property to find
670  * @lenp: pointer to an integer variable (will be overwritten) or NULL
671  *
672  * fdt_getprop() retrieves a pointer to the value of the property
673  * named 'name' of the node at offset nodeoffset (this will be a
674  * pointer to within the device blob itself, not a copy of the value).
675  * If lenp is non-NULL, the length of the property value is also
676  * returned, in the integer pointed to by lenp.
677  *
678  * returns:
679  *	pointer to the property's value
680  *		if lenp is non-NULL, *lenp contains the length of the property
681  *		value (>=0)
682  *	NULL, on error
683  *		if lenp is non-NULL, *lenp contains an error code (<0):
684  *		-FDT_ERR_NOTFOUND, node does not have named property
685  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE
686  *			tag
687  *		-FDT_ERR_BADMAGIC,
688  *		-FDT_ERR_BADVERSION,
689  *		-FDT_ERR_BADSTATE,
690  *		-FDT_ERR_BADSTRUCTURE,
691  *		-FDT_ERR_TRUNCATED, standard meanings
692  */
693 const void *fdt_getprop(const void *fdt, int nodeoffset,
694 			const char *name, int *lenp);
fdt_getprop_w(void * fdt,int nodeoffset,const char * name,int * lenp)695 static inline void *fdt_getprop_w(void *fdt, int nodeoffset,
696 				  const char *name, int *lenp)
697 {
698 	return (void *)(uintptr_t)fdt_getprop(fdt, nodeoffset, name, lenp);
699 }
700 
701 /**
702  * fdt_get_phandle - retrieve the phandle of a given node
703  * @fdt: pointer to the device tree blob
704  * @nodeoffset: structure block offset of the node
705  *
706  * fdt_get_phandle() retrieves the phandle of the device tree node at
707  * structure block offset nodeoffset.
708  *
709  * returns:
710  *	the phandle of the node at nodeoffset, on success (!= 0, != -1)
711  *	0, if the node has no phandle, or another error occurs
712  */
713 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset);
714 
715 /**
716  * fdt_get_alias_namelen - get alias based on substring
717  * @fdt: pointer to the device tree blob
718  * @name: name of the alias th look up
719  * @namelen: number of characters of name to consider
720  *
721  * Identical to fdt_get_alias(), but only examine the first namelen
722  * characters of name for matching the alias name.
723  */
724 #ifndef SWIG /* Not available in Python */
725 const char *fdt_get_alias_namelen(const void *fdt,
726 				  const char *name, int namelen);
727 #endif
728 
729 /**
730  * fdt_get_alias - retrieve the path referenced by a given alias
731  * @fdt: pointer to the device tree blob
732  * @name: name of the alias th look up
733  *
734  * fdt_get_alias() retrieves the value of a given alias.  That is, the
735  * value of the property named 'name' in the node /aliases.
736  *
737  * returns:
738  *	a pointer to the expansion of the alias named 'name', if it exists
739  *	NULL, if the given alias or the /aliases node does not exist
740  */
741 const char *fdt_get_alias(const void *fdt, const char *name);
742 
743 /**
744  * fdt_get_path - determine the full path of a node
745  * @fdt: pointer to the device tree blob
746  * @nodeoffset: offset of the node whose path to find
747  * @buf: character buffer to contain the returned path (will be overwritten)
748  * @buflen: size of the character buffer at buf
749  *
750  * fdt_get_path() computes the full path of the node at offset
751  * nodeoffset, and records that path in the buffer at buf.
752  *
753  * NOTE: This function is expensive, as it must scan the device tree
754  * structure from the start to nodeoffset.
755  *
756  * returns:
757  *	0, on success
758  *		buf contains the absolute path of the node at
759  *		nodeoffset, as a NUL-terminated string.
760  *	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
761  *	-FDT_ERR_NOSPACE, the path of the given node is longer than (bufsize-1)
762  *		characters and will not fit in the given buffer.
763  *	-FDT_ERR_BADMAGIC,
764  *	-FDT_ERR_BADVERSION,
765  *	-FDT_ERR_BADSTATE,
766  *	-FDT_ERR_BADSTRUCTURE, standard meanings
767  */
768 int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen);
769 
770 /**
771  * fdt_supernode_atdepth_offset - find a specific ancestor of a node
772  * @fdt: pointer to the device tree blob
773  * @nodeoffset: offset of the node whose parent to find
774  * @supernodedepth: depth of the ancestor to find
775  * @nodedepth: pointer to an integer variable (will be overwritten) or NULL
776  *
777  * fdt_supernode_atdepth_offset() finds an ancestor of the given node
778  * at a specific depth from the root (where the root itself has depth
779  * 0, its immediate subnodes depth 1 and so forth).  So
780  *	fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, NULL);
781  * will always return 0, the offset of the root node.  If the node at
782  * nodeoffset has depth D, then:
783  *	fdt_supernode_atdepth_offset(fdt, nodeoffset, D, NULL);
784  * will return nodeoffset itself.
785  *
786  * NOTE: This function is expensive, as it must scan the device tree
787  * structure from the start to nodeoffset.
788  *
789  * returns:
790  *	structure block offset of the node at node offset's ancestor
791  *		of depth supernodedepth (>=0), on success
792  *	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
793  *	-FDT_ERR_NOTFOUND, supernodedepth was greater than the depth of
794  *		nodeoffset
795  *	-FDT_ERR_BADMAGIC,
796  *	-FDT_ERR_BADVERSION,
797  *	-FDT_ERR_BADSTATE,
798  *	-FDT_ERR_BADSTRUCTURE, standard meanings
799  */
800 int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
801 				 int supernodedepth, int *nodedepth);
802 
803 /**
804  * fdt_node_depth - find the depth of a given node
805  * @fdt: pointer to the device tree blob
806  * @nodeoffset: offset of the node whose parent to find
807  *
808  * fdt_node_depth() finds the depth of a given node.  The root node
809  * has depth 0, its immediate subnodes depth 1 and so forth.
810  *
811  * NOTE: This function is expensive, as it must scan the device tree
812  * structure from the start to nodeoffset.
813  *
814  * returns:
815  *	depth of the node at nodeoffset (>=0), on success
816  *	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
817  *	-FDT_ERR_BADMAGIC,
818  *	-FDT_ERR_BADVERSION,
819  *	-FDT_ERR_BADSTATE,
820  *	-FDT_ERR_BADSTRUCTURE, standard meanings
821  */
822 int fdt_node_depth(const void *fdt, int nodeoffset);
823 
824 /**
825  * fdt_parent_offset - find the parent of a given node
826  * @fdt: pointer to the device tree blob
827  * @nodeoffset: offset of the node whose parent to find
828  *
829  * fdt_parent_offset() locates the parent node of a given node (that
830  * is, it finds the offset of the node which contains the node at
831  * nodeoffset as a subnode).
832  *
833  * NOTE: This function is expensive, as it must scan the device tree
834  * structure from the start to nodeoffset, *twice*.
835  *
836  * returns:
837  *	structure block offset of the parent of the node at nodeoffset
838  *		(>=0), on success
839  *	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
840  *	-FDT_ERR_BADMAGIC,
841  *	-FDT_ERR_BADVERSION,
842  *	-FDT_ERR_BADSTATE,
843  *	-FDT_ERR_BADSTRUCTURE, standard meanings
844  */
845 int fdt_parent_offset(const void *fdt, int nodeoffset);
846 
847 /**
848  * fdt_node_offset_by_prop_value - find nodes with a given property value
849  * @fdt: pointer to the device tree blob
850  * @startoffset: only find nodes after this offset
851  * @propname: property name to check
852  * @propval: property value to search for
853  * @proplen: length of the value in propval
854  *
855  * fdt_node_offset_by_prop_value() returns the offset of the first
856  * node after startoffset, which has a property named propname whose
857  * value is of length proplen and has value equal to propval; or if
858  * startoffset is -1, the very first such node in the tree.
859  *
860  * To iterate through all nodes matching the criterion, the following
861  * idiom can be used:
862  *	offset = fdt_node_offset_by_prop_value(fdt, -1, propname,
863  *					       propval, proplen);
864  *	while (offset != -FDT_ERR_NOTFOUND) {
865  *		// other code here
866  *		offset = fdt_node_offset_by_prop_value(fdt, offset, propname,
867  *						       propval, proplen);
868  *	}
869  *
870  * Note the -1 in the first call to the function, if 0 is used here
871  * instead, the function will never locate the root node, even if it
872  * matches the criterion.
873  *
874  * returns:
875  *	structure block offset of the located node (>= 0, >startoffset),
876  *		 on success
877  *	-FDT_ERR_NOTFOUND, no node matching the criterion exists in the
878  *		tree after startoffset
879  *	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
880  *	-FDT_ERR_BADMAGIC,
881  *	-FDT_ERR_BADVERSION,
882  *	-FDT_ERR_BADSTATE,
883  *	-FDT_ERR_BADSTRUCTURE, standard meanings
884  */
885 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
886 				  const char *propname,
887 				  const void *propval, int proplen);
888 
889 /**
890  * fdt_node_offset_by_phandle - find the node with a given phandle
891  * @fdt: pointer to the device tree blob
892  * @phandle: phandle value
893  *
894  * fdt_node_offset_by_phandle() returns the offset of the node
895  * which has the given phandle value.  If there is more than one node
896  * in the tree with the given phandle (an invalid tree), results are
897  * undefined.
898  *
899  * returns:
900  *	structure block offset of the located node (>= 0), on success
901  *	-FDT_ERR_NOTFOUND, no node with that phandle exists
902  *	-FDT_ERR_BADPHANDLE, given phandle value was invalid (0 or -1)
903  *	-FDT_ERR_BADMAGIC,
904  *	-FDT_ERR_BADVERSION,
905  *	-FDT_ERR_BADSTATE,
906  *	-FDT_ERR_BADSTRUCTURE, standard meanings
907  */
908 int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle);
909 
910 /**
911  * fdt_node_check_compatible: check a node's compatible property
912  * @fdt: pointer to the device tree blob
913  * @nodeoffset: offset of a tree node
914  * @compatible: string to match against
915  *
916  *
917  * fdt_node_check_compatible() returns 0 if the given node contains a
918  * 'compatible' property with the given string as one of its elements,
919  * it returns non-zero otherwise, or on error.
920  *
921  * returns:
922  *	0, if the node has a 'compatible' property listing the given string
923  *	1, if the node has a 'compatible' property, but it does not list
924  *		the given string
925  *	-FDT_ERR_NOTFOUND, if the given node has no 'compatible' property
926  *	-FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag
927  *	-FDT_ERR_BADMAGIC,
928  *	-FDT_ERR_BADVERSION,
929  *	-FDT_ERR_BADSTATE,
930  *	-FDT_ERR_BADSTRUCTURE, standard meanings
931  */
932 int fdt_node_check_compatible(const void *fdt, int nodeoffset,
933 			      const char *compatible);
934 
935 /**
936  * fdt_node_offset_by_compatible - find nodes with a given 'compatible' value
937  * @fdt: pointer to the device tree blob
938  * @startoffset: only find nodes after this offset
939  * @compatible: 'compatible' string to match against
940  *
941  * fdt_node_offset_by_compatible() returns the offset of the first
942  * node after startoffset, which has a 'compatible' property which
943  * lists the given compatible string; or if startoffset is -1, the
944  * very first such node in the tree.
945  *
946  * To iterate through all nodes matching the criterion, the following
947  * idiom can be used:
948  *	offset = fdt_node_offset_by_compatible(fdt, -1, compatible);
949  *	while (offset != -FDT_ERR_NOTFOUND) {
950  *		// other code here
951  *		offset = fdt_node_offset_by_compatible(fdt, offset, compatible);
952  *	}
953  *
954  * Note the -1 in the first call to the function, if 0 is used here
955  * instead, the function will never locate the root node, even if it
956  * matches the criterion.
957  *
958  * returns:
959  *	structure block offset of the located node (>= 0, >startoffset),
960  *		 on success
961  *	-FDT_ERR_NOTFOUND, no node matching the criterion exists in the
962  *		tree after startoffset
963  *	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
964  *	-FDT_ERR_BADMAGIC,
965  *	-FDT_ERR_BADVERSION,
966  *	-FDT_ERR_BADSTATE,
967  *	-FDT_ERR_BADSTRUCTURE, standard meanings
968  */
969 int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
970 				  const char *compatible);
971 
972 /**
973  * fdt_stringlist_contains - check a string list property for a string
974  * @strlist: Property containing a list of strings to check
975  * @listlen: Length of property
976  * @str: String to search for
977  *
978  * This is a utility function provided for convenience. The list contains
979  * one or more strings, each terminated by \0, as is found in a device tree
980  * "compatible" property.
981  *
982  * @return: 1 if the string is found in the list, 0 not found, or invalid list
983  */
984 int fdt_stringlist_contains(const char *strlist, int listlen, const char *str);
985 
986 /**
987  * fdt_stringlist_count - count the number of strings in a string list
988  * @fdt: pointer to the device tree blob
989  * @nodeoffset: offset of a tree node
990  * @property: name of the property containing the string list
991  * @return:
992  *   the number of strings in the given property
993  *   -FDT_ERR_BADVALUE if the property value is not NUL-terminated
994  *   -FDT_ERR_NOTFOUND if the property does not exist
995  */
996 int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property);
997 
998 /**
999  * fdt_stringlist_search - find a string in a string list and return its index
1000  * @fdt: pointer to the device tree blob
1001  * @nodeoffset: offset of a tree node
1002  * @property: name of the property containing the string list
1003  * @string: string to look up in the string list
1004  *
1005  * Note that it is possible for this function to succeed on property values
1006  * that are not NUL-terminated. That's because the function will stop after
1007  * finding the first occurrence of @string. This can for example happen with
1008  * small-valued cell properties, such as #address-cells, when searching for
1009  * the empty string.
1010  *
1011  * @return:
1012  *   the index of the string in the list of strings
1013  *   -FDT_ERR_BADVALUE if the property value is not NUL-terminated
1014  *   -FDT_ERR_NOTFOUND if the property does not exist or does not contain
1015  *                     the given string
1016  */
1017 int fdt_stringlist_search(const void *fdt, int nodeoffset, const char *property,
1018 			  const char *string);
1019 
1020 /**
1021  * fdt_stringlist_get() - obtain the string at a given index in a string list
1022  * @fdt: pointer to the device tree blob
1023  * @nodeoffset: offset of a tree node
1024  * @property: name of the property containing the string list
1025  * @index: index of the string to return
1026  * @lenp: return location for the string length or an error code on failure
1027  *
1028  * Note that this will successfully extract strings from properties with
1029  * non-NUL-terminated values. For example on small-valued cell properties
1030  * this function will return the empty string.
1031  *
1032  * If non-NULL, the length of the string (on success) or a negative error-code
1033  * (on failure) will be stored in the integer pointer to by lenp.
1034  *
1035  * @return:
1036  *   A pointer to the string at the given index in the string list or NULL on
1037  *   failure. On success the length of the string will be stored in the memory
1038  *   location pointed to by the lenp parameter, if non-NULL. On failure one of
1039  *   the following negative error codes will be returned in the lenp parameter
1040  *   (if non-NULL):
1041  *     -FDT_ERR_BADVALUE if the property value is not NUL-terminated
1042  *     -FDT_ERR_NOTFOUND if the property does not exist
1043  */
1044 const char *fdt_stringlist_get(const void *fdt, int nodeoffset,
1045 			       const char *property, int index,
1046 			       int *lenp);
1047 
1048 /**********************************************************************/
1049 /* Read-only functions (addressing related)                           */
1050 /**********************************************************************/
1051 
1052 /**
1053  * FDT_MAX_NCELLS - maximum value for #address-cells and #size-cells
1054  *
1055  * This is the maximum value for #address-cells, #size-cells and
1056  * similar properties that will be processed by libfdt.  IEE1275
1057  * requires that OF implementations handle values up to 4.
1058  * Implementations may support larger values, but in practice higher
1059  * values aren't used.
1060  */
1061 #define FDT_MAX_NCELLS		4
1062 
1063 /**
1064  * fdt_address_cells - retrieve address size for a bus represented in the tree
1065  * @fdt: pointer to the device tree blob
1066  * @nodeoffset: offset of the node to find the address size for
1067  *
1068  * When the node has a valid #address-cells property, returns its value.
1069  *
1070  * returns:
1071  *	0 <= n < FDT_MAX_NCELLS, on success
1072  *      2, if the node has no #address-cells property
1073  *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
1074  *		#address-cells property
1075  *	-FDT_ERR_BADMAGIC,
1076  *	-FDT_ERR_BADVERSION,
1077  *	-FDT_ERR_BADSTATE,
1078  *	-FDT_ERR_BADSTRUCTURE,
1079  *	-FDT_ERR_TRUNCATED, standard meanings
1080  */
1081 int fdt_address_cells(const void *fdt, int nodeoffset);
1082 
1083 /**
1084  * fdt_size_cells - retrieve address range size for a bus represented in the
1085  *                  tree
1086  * @fdt: pointer to the device tree blob
1087  * @nodeoffset: offset of the node to find the address range size for
1088  *
1089  * When the node has a valid #size-cells property, returns its value.
1090  *
1091  * returns:
1092  *	0 <= n < FDT_MAX_NCELLS, on success
1093  *      2, if the node has no #address-cells property
1094  *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
1095  *		#size-cells property
1096  *	-FDT_ERR_BADMAGIC,
1097  *	-FDT_ERR_BADVERSION,
1098  *	-FDT_ERR_BADSTATE,
1099  *	-FDT_ERR_BADSTRUCTURE,
1100  *	-FDT_ERR_TRUNCATED, standard meanings
1101  */
1102 int fdt_size_cells(const void *fdt, int nodeoffset);
1103 
1104 
1105 /**********************************************************************/
1106 /* Write-in-place functions                                           */
1107 /**********************************************************************/
1108 
1109 /**
1110  * fdt_setprop_inplace_namelen_partial - change a property's value,
1111  *                                       but not its size
1112  * @fdt: pointer to the device tree blob
1113  * @nodeoffset: offset of the node whose property to change
1114  * @name: name of the property to change
1115  * @namelen: number of characters of name to consider
1116  * @idx: index of the property to change in the array
1117  * @val: pointer to data to replace the property value with
1118  * @len: length of the property value
1119  *
1120  * Identical to fdt_setprop_inplace(), but modifies the given property
1121  * starting from the given index, and using only the first characters
1122  * of the name. It is useful when you want to manipulate only one value of
1123  * an array and you have a string that doesn't end with \0.
1124  */
1125 #ifndef SWIG /* Not available in Python */
1126 int fdt_setprop_inplace_namelen_partial(void *fdt, int nodeoffset,
1127 					const char *name, int namelen,
1128 					uint32_t idx, const void *val,
1129 					int len);
1130 #endif
1131 
1132 /**
1133  * fdt_setprop_inplace - change a property's value, but not its size
1134  * @fdt: pointer to the device tree blob
1135  * @nodeoffset: offset of the node whose property to change
1136  * @name: name of the property to change
1137  * @val: pointer to data to replace the property value with
1138  * @len: length of the property value
1139  *
1140  * fdt_setprop_inplace() replaces the value of a given property with
1141  * the data in val, of length len.  This function cannot change the
1142  * size of a property, and so will only work if len is equal to the
1143  * current length of the property.
1144  *
1145  * This function will alter only the bytes in the blob which contain
1146  * the given property value, and will not alter or move any other part
1147  * of the tree.
1148  *
1149  * returns:
1150  *	0, on success
1151  *	-FDT_ERR_NOSPACE, if len is not equal to the property's current length
1152  *	-FDT_ERR_NOTFOUND, node does not have the named property
1153  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1154  *	-FDT_ERR_BADMAGIC,
1155  *	-FDT_ERR_BADVERSION,
1156  *	-FDT_ERR_BADSTATE,
1157  *	-FDT_ERR_BADSTRUCTURE,
1158  *	-FDT_ERR_TRUNCATED, standard meanings
1159  */
1160 #ifndef SWIG /* Not available in Python */
1161 int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
1162 			const void *val, int len);
1163 #endif
1164 
1165 /**
1166  * fdt_setprop_inplace_u32 - change the value of a 32-bit integer property
1167  * @fdt: pointer to the device tree blob
1168  * @nodeoffset: offset of the node whose property to change
1169  * @name: name of the property to change
1170  * @val: 32-bit integer value to replace the property with
1171  *
1172  * fdt_setprop_inplace_u32() replaces the value of a given property
1173  * with the 32-bit integer value in val, converting val to big-endian
1174  * if necessary.  This function cannot change the size of a property,
1175  * and so will only work if the property already exists and has length
1176  * 4.
1177  *
1178  * This function will alter only the bytes in the blob which contain
1179  * the given property value, and will not alter or move any other part
1180  * of the tree.
1181  *
1182  * returns:
1183  *	0, on success
1184  *	-FDT_ERR_NOSPACE, if the property's length is not equal to 4
1185  *	-FDT_ERR_NOTFOUND, node does not have the named property
1186  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1187  *	-FDT_ERR_BADMAGIC,
1188  *	-FDT_ERR_BADVERSION,
1189  *	-FDT_ERR_BADSTATE,
1190  *	-FDT_ERR_BADSTRUCTURE,
1191  *	-FDT_ERR_TRUNCATED, standard meanings
1192  */
fdt_setprop_inplace_u32(void * fdt,int nodeoffset,const char * name,uint32_t val)1193 static inline int fdt_setprop_inplace_u32(void *fdt, int nodeoffset,
1194 					  const char *name, uint32_t val)
1195 {
1196 	fdt32_t tmp = cpu_to_fdt32(val);
1197 	return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1198 }
1199 
1200 /**
1201  * fdt_setprop_inplace_u64 - change the value of a 64-bit integer property
1202  * @fdt: pointer to the device tree blob
1203  * @nodeoffset: offset of the node whose property to change
1204  * @name: name of the property to change
1205  * @val: 64-bit integer value to replace the property with
1206  *
1207  * fdt_setprop_inplace_u64() replaces the value of a given property
1208  * with the 64-bit integer value in val, converting val to big-endian
1209  * if necessary.  This function cannot change the size of a property,
1210  * and so will only work if the property already exists and has length
1211  * 8.
1212  *
1213  * This function will alter only the bytes in the blob which contain
1214  * the given property value, and will not alter or move any other part
1215  * of the tree.
1216  *
1217  * returns:
1218  *	0, on success
1219  *	-FDT_ERR_NOSPACE, if the property's length is not equal to 8
1220  *	-FDT_ERR_NOTFOUND, node does not have the named property
1221  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1222  *	-FDT_ERR_BADMAGIC,
1223  *	-FDT_ERR_BADVERSION,
1224  *	-FDT_ERR_BADSTATE,
1225  *	-FDT_ERR_BADSTRUCTURE,
1226  *	-FDT_ERR_TRUNCATED, standard meanings
1227  */
fdt_setprop_inplace_u64(void * fdt,int nodeoffset,const char * name,uint64_t val)1228 static inline int fdt_setprop_inplace_u64(void *fdt, int nodeoffset,
1229 					  const char *name, uint64_t val)
1230 {
1231 	fdt64_t tmp = cpu_to_fdt64(val);
1232 	return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1233 }
1234 
1235 /**
1236  * fdt_setprop_inplace_cell - change the value of a single-cell property
1237  *
1238  * This is an alternative name for fdt_setprop_inplace_u32()
1239  */
fdt_setprop_inplace_cell(void * fdt,int nodeoffset,const char * name,uint32_t val)1240 static inline int fdt_setprop_inplace_cell(void *fdt, int nodeoffset,
1241 					   const char *name, uint32_t val)
1242 {
1243 	return fdt_setprop_inplace_u32(fdt, nodeoffset, name, val);
1244 }
1245 
1246 /**
1247  * fdt_nop_property - replace a property with nop tags
1248  * @fdt: pointer to the device tree blob
1249  * @nodeoffset: offset of the node whose property to nop
1250  * @name: name of the property to nop
1251  *
1252  * fdt_nop_property() will replace a given property's representation
1253  * in the blob with FDT_NOP tags, effectively removing it from the
1254  * tree.
1255  *
1256  * This function will alter only the bytes in the blob which contain
1257  * the property, and will not alter or move any other part of the
1258  * tree.
1259  *
1260  * returns:
1261  *	0, on success
1262  *	-FDT_ERR_NOTFOUND, node does not have the named property
1263  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1264  *	-FDT_ERR_BADMAGIC,
1265  *	-FDT_ERR_BADVERSION,
1266  *	-FDT_ERR_BADSTATE,
1267  *	-FDT_ERR_BADSTRUCTURE,
1268  *	-FDT_ERR_TRUNCATED, standard meanings
1269  */
1270 int fdt_nop_property(void *fdt, int nodeoffset, const char *name);
1271 
1272 /**
1273  * fdt_nop_node - replace a node (subtree) with nop tags
1274  * @fdt: pointer to the device tree blob
1275  * @nodeoffset: offset of the node to nop
1276  *
1277  * fdt_nop_node() will replace a given node's representation in the
1278  * blob, including all its subnodes, if any, with FDT_NOP tags,
1279  * effectively removing it from the tree.
1280  *
1281  * This function will alter only the bytes in the blob which contain
1282  * the node and its properties and subnodes, and will not alter or
1283  * move any other part of the tree.
1284  *
1285  * returns:
1286  *	0, on success
1287  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1288  *	-FDT_ERR_BADMAGIC,
1289  *	-FDT_ERR_BADVERSION,
1290  *	-FDT_ERR_BADSTATE,
1291  *	-FDT_ERR_BADSTRUCTURE,
1292  *	-FDT_ERR_TRUNCATED, standard meanings
1293  */
1294 int fdt_nop_node(void *fdt, int nodeoffset);
1295 
1296 /**********************************************************************/
1297 /* Sequential write functions                                         */
1298 /**********************************************************************/
1299 
1300 int fdt_create(void *buf, int bufsize);
1301 int fdt_resize(void *fdt, void *buf, int bufsize);
1302 int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size);
1303 int fdt_finish_reservemap(void *fdt);
1304 int fdt_begin_node(void *fdt, const char *name);
1305 int fdt_property(void *fdt, const char *name, const void *val, int len);
fdt_property_u32(void * fdt,const char * name,uint32_t val)1306 static inline int fdt_property_u32(void *fdt, const char *name, uint32_t val)
1307 {
1308 	fdt32_t tmp = cpu_to_fdt32(val);
1309 	return fdt_property(fdt, name, &tmp, sizeof(tmp));
1310 }
fdt_property_u64(void * fdt,const char * name,uint64_t val)1311 static inline int fdt_property_u64(void *fdt, const char *name, uint64_t val)
1312 {
1313 	fdt64_t tmp = cpu_to_fdt64(val);
1314 	return fdt_property(fdt, name, &tmp, sizeof(tmp));
1315 }
1316 
1317 #ifndef SWIG /* Not available in Python */
fdt_property_cell(void * fdt,const char * name,uint32_t val)1318 static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val)
1319 {
1320 	return fdt_property_u32(fdt, name, val);
1321 }
1322 #endif
1323 
1324 /**
1325  * fdt_property_placeholder - add a new property and return a ptr to its value
1326  *
1327  * @fdt: pointer to the device tree blob
1328  * @name: name of property to add
1329  * @len: length of property value in bytes
1330  * @valp: returns a pointer to where where the value should be placed
1331  *
1332  * returns:
1333  *	0, on success
1334  *	-FDT_ERR_BADMAGIC,
1335  *	-FDT_ERR_NOSPACE, standard meanings
1336  */
1337 int fdt_property_placeholder(void *fdt, const char *name, int len, void **valp);
1338 
1339 #define fdt_property_string(fdt, name, str) \
1340 	fdt_property(fdt, name, str, strlen(str)+1)
1341 int fdt_end_node(void *fdt);
1342 int fdt_finish(void *fdt);
1343 
1344 /**********************************************************************/
1345 /* Read-write functions                                               */
1346 /**********************************************************************/
1347 
1348 int fdt_create_empty_tree(void *buf, int bufsize);
1349 int fdt_open_into(const void *fdt, void *buf, int bufsize);
1350 int fdt_pack(void *fdt);
1351 
1352 /**
1353  * fdt_add_mem_rsv - add one memory reserve map entry
1354  * @fdt: pointer to the device tree blob
1355  * @address, @size: 64-bit values (native endian)
1356  *
1357  * Adds a reserve map entry to the given blob reserving a region at
1358  * address address of length size.
1359  *
1360  * This function will insert data into the reserve map and will
1361  * therefore change the indexes of some entries in the table.
1362  *
1363  * returns:
1364  *	0, on success
1365  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1366  *		contain the new reservation entry
1367  *	-FDT_ERR_BADMAGIC,
1368  *	-FDT_ERR_BADVERSION,
1369  *	-FDT_ERR_BADSTATE,
1370  *	-FDT_ERR_BADSTRUCTURE,
1371  *	-FDT_ERR_BADLAYOUT,
1372  *	-FDT_ERR_TRUNCATED, standard meanings
1373  */
1374 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size);
1375 
1376 /**
1377  * fdt_del_mem_rsv - remove a memory reserve map entry
1378  * @fdt: pointer to the device tree blob
1379  * @n: entry to remove
1380  *
1381  * fdt_del_mem_rsv() removes the n-th memory reserve map entry from
1382  * the blob.
1383  *
1384  * This function will delete data from the reservation table and will
1385  * therefore change the indexes of some entries in the table.
1386  *
1387  * returns:
1388  *	0, on success
1389  *	-FDT_ERR_NOTFOUND, there is no entry of the given index (i.e. there
1390  *		are less than n+1 reserve map entries)
1391  *	-FDT_ERR_BADMAGIC,
1392  *	-FDT_ERR_BADVERSION,
1393  *	-FDT_ERR_BADSTATE,
1394  *	-FDT_ERR_BADSTRUCTURE,
1395  *	-FDT_ERR_BADLAYOUT,
1396  *	-FDT_ERR_TRUNCATED, standard meanings
1397  */
1398 int fdt_del_mem_rsv(void *fdt, int n);
1399 
1400 /**
1401  * fdt_set_name - change the name of a given node
1402  * @fdt: pointer to the device tree blob
1403  * @nodeoffset: structure block offset of a node
1404  * @name: name to give the node
1405  *
1406  * fdt_set_name() replaces the name (including unit address, if any)
1407  * of the given node with the given string.  NOTE: this function can't
1408  * efficiently check if the new name is unique amongst the given
1409  * node's siblings; results are undefined if this function is invoked
1410  * with a name equal to one of the given node's siblings.
1411  *
1412  * This function may insert or delete data from the blob, and will
1413  * therefore change the offsets of some existing nodes.
1414  *
1415  * returns:
1416  *	0, on success
1417  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob
1418  *		to contain the new name
1419  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1420  *	-FDT_ERR_BADMAGIC,
1421  *	-FDT_ERR_BADVERSION,
1422  *	-FDT_ERR_BADSTATE, standard meanings
1423  */
1424 int fdt_set_name(void *fdt, int nodeoffset, const char *name);
1425 
1426 /**
1427  * fdt_setprop - create or change a property
1428  * @fdt: pointer to the device tree blob
1429  * @nodeoffset: offset of the node whose property to change
1430  * @name: name of the property to change
1431  * @val: pointer to data to set the property value to
1432  * @len: length of the property value
1433  *
1434  * fdt_setprop() sets the value of the named property in the given
1435  * node to the given value and length, creating the property if it
1436  * does not already exist.
1437  *
1438  * This function may insert or delete data from the blob, and will
1439  * therefore change the offsets of some existing nodes.
1440  *
1441  * returns:
1442  *	0, on success
1443  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1444  *		contain the new property value
1445  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1446  *	-FDT_ERR_BADLAYOUT,
1447  *	-FDT_ERR_BADMAGIC,
1448  *	-FDT_ERR_BADVERSION,
1449  *	-FDT_ERR_BADSTATE,
1450  *	-FDT_ERR_BADSTRUCTURE,
1451  *	-FDT_ERR_BADLAYOUT,
1452  *	-FDT_ERR_TRUNCATED, standard meanings
1453  */
1454 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
1455 		const void *val, int len);
1456 
1457 /**
1458  * fdt_setprop_placeholder - allocate space for a property
1459  * @fdt: pointer to the device tree blob
1460  * @nodeoffset: offset of the node whose property to change
1461  * @name: name of the property to change
1462  * @len: length of the property value
1463  * @prop_data: return pointer to property data
1464  *
1465  * fdt_setprop_placeholer() allocates the named property in the given node.
1466  * If the property exists it is resized. In either case a pointer to the
1467  * property data is returned.
1468  *
1469  * This function may insert or delete data from the blob, and will
1470  * therefore change the offsets of some existing nodes.
1471  *
1472  * returns:
1473  *	0, on success
1474  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1475  *		contain the new property value
1476  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1477  *	-FDT_ERR_BADLAYOUT,
1478  *	-FDT_ERR_BADMAGIC,
1479  *	-FDT_ERR_BADVERSION,
1480  *	-FDT_ERR_BADSTATE,
1481  *	-FDT_ERR_BADSTRUCTURE,
1482  *	-FDT_ERR_BADLAYOUT,
1483  *	-FDT_ERR_TRUNCATED, standard meanings
1484  */
1485 int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name,
1486 			    int len, void **prop_data);
1487 
1488 /**
1489  * fdt_setprop_u32 - set a property to a 32-bit integer
1490  * @fdt: pointer to the device tree blob
1491  * @nodeoffset: offset of the node whose property to change
1492  * @name: name of the property to change
1493  * @val: 32-bit integer value for the property (native endian)
1494  *
1495  * fdt_setprop_u32() sets the value of the named property in the given
1496  * node to the given 32-bit integer value (converting to big-endian if
1497  * necessary), or creates a new property with that value if it does
1498  * not already exist.
1499  *
1500  * This function may insert or delete data from the blob, and will
1501  * therefore change the offsets of some existing nodes.
1502  *
1503  * returns:
1504  *	0, on success
1505  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1506  *		contain the new property value
1507  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1508  *	-FDT_ERR_BADLAYOUT,
1509  *	-FDT_ERR_BADMAGIC,
1510  *	-FDT_ERR_BADVERSION,
1511  *	-FDT_ERR_BADSTATE,
1512  *	-FDT_ERR_BADSTRUCTURE,
1513  *	-FDT_ERR_BADLAYOUT,
1514  *	-FDT_ERR_TRUNCATED, standard meanings
1515  */
fdt_setprop_u32(void * fdt,int nodeoffset,const char * name,uint32_t val)1516 static inline int fdt_setprop_u32(void *fdt, int nodeoffset, const char *name,
1517 				  uint32_t val)
1518 {
1519 	fdt32_t tmp = cpu_to_fdt32(val);
1520 	return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1521 }
1522 
1523 /**
1524  * fdt_setprop_u64 - set a property to a 64-bit integer
1525  * @fdt: pointer to the device tree blob
1526  * @nodeoffset: offset of the node whose property to change
1527  * @name: name of the property to change
1528  * @val: 64-bit integer value for the property (native endian)
1529  *
1530  * fdt_setprop_u64() sets the value of the named property in the given
1531  * node to the given 64-bit integer value (converting to big-endian if
1532  * necessary), or creates a new property with that value if it does
1533  * not already exist.
1534  *
1535  * This function may insert or delete data from the blob, and will
1536  * therefore change the offsets of some existing nodes.
1537  *
1538  * returns:
1539  *	0, on success
1540  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1541  *		contain the new property value
1542  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1543  *	-FDT_ERR_BADLAYOUT,
1544  *	-FDT_ERR_BADMAGIC,
1545  *	-FDT_ERR_BADVERSION,
1546  *	-FDT_ERR_BADSTATE,
1547  *	-FDT_ERR_BADSTRUCTURE,
1548  *	-FDT_ERR_BADLAYOUT,
1549  *	-FDT_ERR_TRUNCATED, standard meanings
1550  */
fdt_setprop_u64(void * fdt,int nodeoffset,const char * name,uint64_t val)1551 static inline int fdt_setprop_u64(void *fdt, int nodeoffset, const char *name,
1552 				  uint64_t val)
1553 {
1554 	fdt64_t tmp = cpu_to_fdt64(val);
1555 	return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1556 }
1557 
1558 /**
1559  * fdt_setprop_cell - set a property to a single cell value
1560  *
1561  * This is an alternative name for fdt_setprop_u32()
1562  */
fdt_setprop_cell(void * fdt,int nodeoffset,const char * name,uint32_t val)1563 static inline int fdt_setprop_cell(void *fdt, int nodeoffset, const char *name,
1564 				   uint32_t val)
1565 {
1566 	return fdt_setprop_u32(fdt, nodeoffset, name, val);
1567 }
1568 
1569 /**
1570  * fdt_setprop_string - set a property to a string value
1571  * @fdt: pointer to the device tree blob
1572  * @nodeoffset: offset of the node whose property to change
1573  * @name: name of the property to change
1574  * @str: string value for the property
1575  *
1576  * fdt_setprop_string() sets the value of the named property in the
1577  * given node to the given string value (using the length of the
1578  * string to determine the new length of the property), or creates a
1579  * new property with that value if it does not already exist.
1580  *
1581  * This function may insert or delete data from the blob, and will
1582  * therefore change the offsets of some existing nodes.
1583  *
1584  * returns:
1585  *	0, on success
1586  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1587  *		contain the new property value
1588  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1589  *	-FDT_ERR_BADLAYOUT,
1590  *	-FDT_ERR_BADMAGIC,
1591  *	-FDT_ERR_BADVERSION,
1592  *	-FDT_ERR_BADSTATE,
1593  *	-FDT_ERR_BADSTRUCTURE,
1594  *	-FDT_ERR_BADLAYOUT,
1595  *	-FDT_ERR_TRUNCATED, standard meanings
1596  */
1597 #define fdt_setprop_string(fdt, nodeoffset, name, str) \
1598 	fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1599 
1600 
1601 /**
1602  * fdt_setprop_empty - set a property to an empty value
1603  * @fdt: pointer to the device tree blob
1604  * @nodeoffset: offset of the node whose property to change
1605  * @name: name of the property to change
1606  *
1607  * fdt_setprop_empty() sets the value of the named property in the
1608  * given node to an empty (zero length) value, or creates a new empty
1609  * property if it does not already exist.
1610  *
1611  * This function may insert or delete data from the blob, and will
1612  * therefore change the offsets of some existing nodes.
1613  *
1614  * returns:
1615  *	0, on success
1616  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1617  *		contain the new property value
1618  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1619  *	-FDT_ERR_BADLAYOUT,
1620  *	-FDT_ERR_BADMAGIC,
1621  *	-FDT_ERR_BADVERSION,
1622  *	-FDT_ERR_BADSTATE,
1623  *	-FDT_ERR_BADSTRUCTURE,
1624  *	-FDT_ERR_BADLAYOUT,
1625  *	-FDT_ERR_TRUNCATED, standard meanings
1626  */
1627 #define fdt_setprop_empty(fdt, nodeoffset, name) \
1628 	fdt_setprop((fdt), (nodeoffset), (name), NULL, 0)
1629 
1630 /**
1631  * fdt_appendprop - append to or create a property
1632  * @fdt: pointer to the device tree blob
1633  * @nodeoffset: offset of the node whose property to change
1634  * @name: name of the property to append to
1635  * @val: pointer to data to append to the property value
1636  * @len: length of the data to append to the property value
1637  *
1638  * fdt_appendprop() appends the value to the named property in the
1639  * given node, creating the property if it does not already exist.
1640  *
1641  * This function may insert data into the blob, and will therefore
1642  * change the offsets of some existing nodes.
1643  *
1644  * returns:
1645  *	0, on success
1646  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1647  *		contain the new property value
1648  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1649  *	-FDT_ERR_BADLAYOUT,
1650  *	-FDT_ERR_BADMAGIC,
1651  *	-FDT_ERR_BADVERSION,
1652  *	-FDT_ERR_BADSTATE,
1653  *	-FDT_ERR_BADSTRUCTURE,
1654  *	-FDT_ERR_BADLAYOUT,
1655  *	-FDT_ERR_TRUNCATED, standard meanings
1656  */
1657 int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
1658 		   const void *val, int len);
1659 
1660 /**
1661  * fdt_appendprop_u32 - append a 32-bit integer value to a property
1662  * @fdt: pointer to the device tree blob
1663  * @nodeoffset: offset of the node whose property to change
1664  * @name: name of the property to change
1665  * @val: 32-bit integer value to append to the property (native endian)
1666  *
1667  * fdt_appendprop_u32() appends the given 32-bit integer value
1668  * (converting to big-endian if necessary) to the value of the named
1669  * property in the given node, or creates a new property with that
1670  * value if it does not already exist.
1671  *
1672  * This function may insert data into the blob, and will therefore
1673  * change the offsets of some existing nodes.
1674  *
1675  * returns:
1676  *	0, on success
1677  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1678  *		contain the new property value
1679  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1680  *	-FDT_ERR_BADLAYOUT,
1681  *	-FDT_ERR_BADMAGIC,
1682  *	-FDT_ERR_BADVERSION,
1683  *	-FDT_ERR_BADSTATE,
1684  *	-FDT_ERR_BADSTRUCTURE,
1685  *	-FDT_ERR_BADLAYOUT,
1686  *	-FDT_ERR_TRUNCATED, standard meanings
1687  */
fdt_appendprop_u32(void * fdt,int nodeoffset,const char * name,uint32_t val)1688 static inline int fdt_appendprop_u32(void *fdt, int nodeoffset,
1689 				     const char *name, uint32_t val)
1690 {
1691 	fdt32_t tmp = cpu_to_fdt32(val);
1692 	return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1693 }
1694 
1695 /**
1696  * fdt_appendprop_u64 - append a 64-bit integer value to a property
1697  * @fdt: pointer to the device tree blob
1698  * @nodeoffset: offset of the node whose property to change
1699  * @name: name of the property to change
1700  * @val: 64-bit integer value to append to the property (native endian)
1701  *
1702  * fdt_appendprop_u64() appends the given 64-bit integer value
1703  * (converting to big-endian if necessary) to the value of the named
1704  * property in the given node, or creates a new property with that
1705  * value if it does not already exist.
1706  *
1707  * This function may insert data into the blob, and will therefore
1708  * change the offsets of some existing nodes.
1709  *
1710  * returns:
1711  *	0, on success
1712  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1713  *		contain the new property value
1714  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1715  *	-FDT_ERR_BADLAYOUT,
1716  *	-FDT_ERR_BADMAGIC,
1717  *	-FDT_ERR_BADVERSION,
1718  *	-FDT_ERR_BADSTATE,
1719  *	-FDT_ERR_BADSTRUCTURE,
1720  *	-FDT_ERR_BADLAYOUT,
1721  *	-FDT_ERR_TRUNCATED, standard meanings
1722  */
fdt_appendprop_u64(void * fdt,int nodeoffset,const char * name,uint64_t val)1723 static inline int fdt_appendprop_u64(void *fdt, int nodeoffset,
1724 				     const char *name, uint64_t val)
1725 {
1726 	fdt64_t tmp = cpu_to_fdt64(val);
1727 	return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1728 }
1729 
1730 /**
1731  * fdt_appendprop_cell - append a single cell value to a property
1732  *
1733  * This is an alternative name for fdt_appendprop_u32()
1734  */
fdt_appendprop_cell(void * fdt,int nodeoffset,const char * name,uint32_t val)1735 static inline int fdt_appendprop_cell(void *fdt, int nodeoffset,
1736 				      const char *name, uint32_t val)
1737 {
1738 	return fdt_appendprop_u32(fdt, nodeoffset, name, val);
1739 }
1740 
1741 /**
1742  * fdt_appendprop_string - append a string to a property
1743  * @fdt: pointer to the device tree blob
1744  * @nodeoffset: offset of the node whose property to change
1745  * @name: name of the property to change
1746  * @str: string value to append to the property
1747  *
1748  * fdt_appendprop_string() appends the given string to the value of
1749  * the named property in the given node, or creates a new property
1750  * with that value if it does not already exist.
1751  *
1752  * This function may insert data into the blob, and will therefore
1753  * change the offsets of some existing nodes.
1754  *
1755  * returns:
1756  *	0, on success
1757  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1758  *		contain the new property value
1759  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1760  *	-FDT_ERR_BADLAYOUT,
1761  *	-FDT_ERR_BADMAGIC,
1762  *	-FDT_ERR_BADVERSION,
1763  *	-FDT_ERR_BADSTATE,
1764  *	-FDT_ERR_BADSTRUCTURE,
1765  *	-FDT_ERR_BADLAYOUT,
1766  *	-FDT_ERR_TRUNCATED, standard meanings
1767  */
1768 #define fdt_appendprop_string(fdt, nodeoffset, name, str) \
1769 	fdt_appendprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1770 
1771 /**
1772  * fdt_delprop - delete a property
1773  * @fdt: pointer to the device tree blob
1774  * @nodeoffset: offset of the node whose property to nop
1775  * @name: name of the property to nop
1776  *
1777  * fdt_del_property() will delete the given property.
1778  *
1779  * This function will delete data from the blob, and will therefore
1780  * change the offsets of some existing nodes.
1781  *
1782  * returns:
1783  *	0, on success
1784  *	-FDT_ERR_NOTFOUND, node does not have the named property
1785  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1786  *	-FDT_ERR_BADLAYOUT,
1787  *	-FDT_ERR_BADMAGIC,
1788  *	-FDT_ERR_BADVERSION,
1789  *	-FDT_ERR_BADSTATE,
1790  *	-FDT_ERR_BADSTRUCTURE,
1791  *	-FDT_ERR_TRUNCATED, standard meanings
1792  */
1793 int fdt_delprop(void *fdt, int nodeoffset, const char *name);
1794 
1795 /**
1796  * fdt_add_subnode_namelen - creates a new node based on substring
1797  * @fdt: pointer to the device tree blob
1798  * @parentoffset: structure block offset of a node
1799  * @name: name of the subnode to locate
1800  * @namelen: number of characters of name to consider
1801  *
1802  * Identical to fdt_add_subnode(), but use only the first namelen
1803  * characters of name as the name of the new node.  This is useful for
1804  * creating subnodes based on a portion of a larger string, such as a
1805  * full path.
1806  */
1807 #ifndef SWIG /* Not available in Python */
1808 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
1809 			    const char *name, int namelen);
1810 #endif
1811 
1812 /**
1813  * fdt_add_subnode - creates a new node
1814  * @fdt: pointer to the device tree blob
1815  * @parentoffset: structure block offset of a node
1816  * @name: name of the subnode to locate
1817  *
1818  * fdt_add_subnode() creates a new node as a subnode of the node at
1819  * structure block offset parentoffset, with the given name (which
1820  * should include the unit address, if any).
1821  *
1822  * This function will insert data into the blob, and will therefore
1823  * change the offsets of some existing nodes.
1824 
1825  * returns:
1826  *	structure block offset of the created nodeequested subnode (>=0), on
1827  *		success
1828  *	-FDT_ERR_NOTFOUND, if the requested subnode does not exist
1829  *	-FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE
1830  *		tag
1831  *	-FDT_ERR_EXISTS, if the node at parentoffset already has a subnode of
1832  *		the given name
1833  *	-FDT_ERR_NOSPACE, if there is insufficient free space in the
1834  *		blob to contain the new node
1835  *	-FDT_ERR_NOSPACE
1836  *	-FDT_ERR_BADLAYOUT
1837  *      -FDT_ERR_BADMAGIC,
1838  *	-FDT_ERR_BADVERSION,
1839  *	-FDT_ERR_BADSTATE,
1840  *	-FDT_ERR_BADSTRUCTURE,
1841  *	-FDT_ERR_TRUNCATED, standard meanings.
1842  */
1843 int fdt_add_subnode(void *fdt, int parentoffset, const char *name);
1844 
1845 /**
1846  * fdt_del_node - delete a node (subtree)
1847  * @fdt: pointer to the device tree blob
1848  * @nodeoffset: offset of the node to nop
1849  *
1850  * fdt_del_node() will remove the given node, including all its
1851  * subnodes if any, from the blob.
1852  *
1853  * This function will delete data from the blob, and will therefore
1854  * change the offsets of some existing nodes.
1855  *
1856  * returns:
1857  *	0, on success
1858  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1859  *	-FDT_ERR_BADLAYOUT,
1860  *	-FDT_ERR_BADMAGIC,
1861  *	-FDT_ERR_BADVERSION,
1862  *	-FDT_ERR_BADSTATE,
1863  *	-FDT_ERR_BADSTRUCTURE,
1864  *	-FDT_ERR_TRUNCATED, standard meanings
1865  */
1866 int fdt_del_node(void *fdt, int nodeoffset);
1867 
1868 /**
1869  * fdt_overlay_apply - Applies a DT overlay on a base DT
1870  * @fdt: pointer to the base device tree blob
1871  * @fdto: pointer to the device tree overlay blob
1872  *
1873  * fdt_overlay_apply() will apply the given device tree overlay on the
1874  * given base device tree.
1875  *
1876  * Expect the base device tree to be modified, even if the function
1877  * returns an error.
1878  *
1879  * returns:
1880  *	0, on success
1881  *	-FDT_ERR_NOSPACE, there's not enough space in the base device tree
1882  *	-FDT_ERR_NOTFOUND, the overlay points to some inexistant nodes or
1883  *		properties in the base DT
1884  *	-FDT_ERR_BADPHANDLE,
1885  *	-FDT_ERR_BADOVERLAY,
1886  *	-FDT_ERR_NOPHANDLES,
1887  *	-FDT_ERR_INTERNAL,
1888  *	-FDT_ERR_BADLAYOUT,
1889  *	-FDT_ERR_BADMAGIC,
1890  *	-FDT_ERR_BADOFFSET,
1891  *	-FDT_ERR_BADPATH,
1892  *	-FDT_ERR_BADVERSION,
1893  *	-FDT_ERR_BADSTRUCTURE,
1894  *	-FDT_ERR_BADSTATE,
1895  *	-FDT_ERR_TRUNCATED, standard meanings
1896  */
1897 int fdt_overlay_apply(void *fdt, void *fdto);
1898 
1899 /**********************************************************************/
1900 /* Debugging / informational functions                                */
1901 /**********************************************************************/
1902 
1903 const char *fdt_strerror(int errval);
1904 
1905 #endif /* LIBFDT_H */
1906