1 /* SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) */
2 #ifndef LIBFDT_H
3 #define LIBFDT_H
4 /*
5  * libfdt - Flat Device Tree manipulation
6  * Copyright (C) 2006 David Gibson, IBM Corporation.
7  */
8 
9 #include "libfdt_env.h"
10 #include "fdt.h"
11 
12 #ifdef __cplusplus
13 extern "C" {
14 #endif
15 
16 #define FDT_FIRST_SUPPORTED_VERSION	0x02
17 #define FDT_LAST_COMPATIBLE_VERSION 0x10
18 #define FDT_LAST_SUPPORTED_VERSION	0x11
19 
20 /* Error codes: informative error codes */
21 #define FDT_ERR_NOTFOUND	1
22 	/* FDT_ERR_NOTFOUND: The requested node or property does not exist */
23 #define FDT_ERR_EXISTS		2
24 	/* FDT_ERR_EXISTS: Attempted to create a node or property which
25 	 * already exists */
26 #define FDT_ERR_NOSPACE		3
27 	/* FDT_ERR_NOSPACE: Operation needed to expand the device
28 	 * tree, but its buffer did not have sufficient space to
29 	 * contain the expanded tree. Use fdt_open_into() to move the
30 	 * device tree to a buffer with more space. */
31 
32 /* Error codes: codes for bad parameters */
33 #define FDT_ERR_BADOFFSET	4
34 	/* FDT_ERR_BADOFFSET: Function was passed a structure block
35 	 * offset which is out-of-bounds, or which points to an
36 	 * unsuitable part of the structure for the operation. */
37 #define FDT_ERR_BADPATH		5
38 	/* FDT_ERR_BADPATH: Function was passed a badly formatted path
39 	 * (e.g. missing a leading / for a function which requires an
40 	 * absolute path) */
41 #define FDT_ERR_BADPHANDLE	6
42 	/* FDT_ERR_BADPHANDLE: Function was passed an invalid phandle.
43 	 * This can be caused either by an invalid phandle property
44 	 * length, or the phandle value was either 0 or -1, which are
45 	 * not permitted. */
46 #define FDT_ERR_BADSTATE	7
47 	/* FDT_ERR_BADSTATE: Function was passed an incomplete device
48 	 * tree created by the sequential-write functions, which is
49 	 * not sufficiently complete for the requested operation. */
50 
51 /* Error codes: codes for bad device tree blobs */
52 #define FDT_ERR_TRUNCATED	8
53 	/* FDT_ERR_TRUNCATED: FDT or a sub-block is improperly
54 	 * terminated (overflows, goes outside allowed bounds, or
55 	 * isn't properly terminated).  */
56 #define FDT_ERR_BADMAGIC	9
57 	/* FDT_ERR_BADMAGIC: Given "device tree" appears not to be a
58 	 * device tree at all - it is missing the flattened device
59 	 * tree magic number. */
60 #define FDT_ERR_BADVERSION	10
61 	/* FDT_ERR_BADVERSION: Given device tree has a version which
62 	 * can't be handled by the requested operation.  For
63 	 * read-write functions, this may mean that fdt_open_into() is
64 	 * required to convert the tree to the expected version. */
65 #define FDT_ERR_BADSTRUCTURE	11
66 	/* FDT_ERR_BADSTRUCTURE: Given device tree has a corrupt
67 	 * structure block or other serious error (e.g. misnested
68 	 * nodes, or subnodes preceding properties). */
69 #define FDT_ERR_BADLAYOUT	12
70 	/* FDT_ERR_BADLAYOUT: For read-write functions, the given
71 	 * device tree has it's sub-blocks in an order that the
72 	 * function can't handle (memory reserve map, then structure,
73 	 * then strings).  Use fdt_open_into() to reorganize the tree
74 	 * into a form suitable for the read-write operations. */
75 
76 /* "Can't happen" error indicating a bug in libfdt */
77 #define FDT_ERR_INTERNAL	13
78 	/* FDT_ERR_INTERNAL: libfdt has failed an internal assertion.
79 	 * Should never be returned, if it is, it indicates a bug in
80 	 * libfdt itself. */
81 
82 /* Errors in device tree content */
83 #define FDT_ERR_BADNCELLS	14
84 	/* FDT_ERR_BADNCELLS: Device tree has a #address-cells, #size-cells
85 	 * or similar property with a bad format or value */
86 
87 #define FDT_ERR_BADVALUE	15
88 	/* FDT_ERR_BADVALUE: Device tree has a property with an unexpected
89 	 * value. For example: a property expected to contain a string list
90 	 * is not NUL-terminated within the length of its value. */
91 
92 #define FDT_ERR_BADOVERLAY	16
93 	/* FDT_ERR_BADOVERLAY: The device tree overlay, while
94 	 * correctly structured, cannot be applied due to some
95 	 * unexpected or missing value, property or node. */
96 
97 #define FDT_ERR_NOPHANDLES	17
98 	/* FDT_ERR_NOPHANDLES: The device tree doesn't have any
99 	 * phandle available anymore without causing an overflow */
100 
101 #define FDT_ERR_BADFLAGS	18
102 	/* FDT_ERR_BADFLAGS: The function was passed a flags field that
103 	 * contains invalid flags or an invalid combination of flags. */
104 
105 #define FDT_ERR_ALIGNMENT	19
106 	/* FDT_ERR_ALIGNMENT: The device tree base address is not 8-byte
107 	 * aligned. */
108 
109 #define FDT_ERR_MAX		19
110 
111 /* constants */
112 #define FDT_MAX_PHANDLE 0xfffffffe
113 	/* Valid values for phandles range from 1 to 2^32-2. */
114 
115 /**********************************************************************/
116 /* Low-level functions (you probably don't need these)                */
117 /**********************************************************************/
118 
119 #ifndef SWIG /* This function is not useful in Python */
120 const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int checklen);
121 #endif
fdt_offset_ptr_w(void * fdt,int offset,int checklen)122 static inline void *fdt_offset_ptr_w(void *fdt, int offset, int checklen)
123 {
124 	return (void *)(uintptr_t)fdt_offset_ptr(fdt, offset, checklen);
125 }
126 
127 uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset);
128 
129 /*
130  * External helpers to access words from a device tree blob. They're built
131  * to work even with unaligned pointers on platforms (such as ARMv5) that don't
132  * like unaligned loads and stores.
133  */
fdt16_ld(const fdt16_t * p)134 static inline uint16_t fdt16_ld(const fdt16_t *p)
135 {
136 	const uint8_t *bp = (const uint8_t *)p;
137 
138 	return ((uint16_t)bp[0] << 8) | bp[1];
139 }
140 
fdt32_ld(const fdt32_t * p)141 static inline uint32_t fdt32_ld(const fdt32_t *p)
142 {
143 	const uint8_t *bp = (const uint8_t *)p;
144 
145 	return ((uint32_t)bp[0] << 24)
146 		| ((uint32_t)bp[1] << 16)
147 		| ((uint32_t)bp[2] << 8)
148 		| bp[3];
149 }
150 
fdt32_st(void * property,uint32_t value)151 static inline void fdt32_st(void *property, uint32_t value)
152 {
153 	uint8_t *bp = (uint8_t *)property;
154 
155 	bp[0] = value >> 24;
156 	bp[1] = (value >> 16) & 0xff;
157 	bp[2] = (value >> 8) & 0xff;
158 	bp[3] = value & 0xff;
159 }
160 
fdt64_ld(const fdt64_t * p)161 static inline uint64_t fdt64_ld(const fdt64_t *p)
162 {
163 	const uint8_t *bp = (const uint8_t *)p;
164 
165 	return ((uint64_t)bp[0] << 56)
166 		| ((uint64_t)bp[1] << 48)
167 		| ((uint64_t)bp[2] << 40)
168 		| ((uint64_t)bp[3] << 32)
169 		| ((uint64_t)bp[4] << 24)
170 		| ((uint64_t)bp[5] << 16)
171 		| ((uint64_t)bp[6] << 8)
172 		| bp[7];
173 }
174 
fdt64_st(void * property,uint64_t value)175 static inline void fdt64_st(void *property, uint64_t value)
176 {
177 	uint8_t *bp = (uint8_t *)property;
178 
179 	bp[0] = value >> 56;
180 	bp[1] = (value >> 48) & 0xff;
181 	bp[2] = (value >> 40) & 0xff;
182 	bp[3] = (value >> 32) & 0xff;
183 	bp[4] = (value >> 24) & 0xff;
184 	bp[5] = (value >> 16) & 0xff;
185 	bp[6] = (value >> 8) & 0xff;
186 	bp[7] = value & 0xff;
187 }
188 
189 /**********************************************************************/
190 /* Traversal functions                                                */
191 /**********************************************************************/
192 
193 int fdt_next_node(const void *fdt, int offset, int *depth);
194 
195 /**
196  * fdt_first_subnode() - get offset of first direct subnode
197  * @fdt:	FDT blob
198  * @offset:	Offset of node to check
199  *
200  * Return: offset of first subnode, or -FDT_ERR_NOTFOUND if there is none
201  */
202 int fdt_first_subnode(const void *fdt, int offset);
203 
204 /**
205  * fdt_next_subnode() - get offset of next direct subnode
206  * @fdt:	FDT blob
207  * @offset:	Offset of previous subnode
208  *
209  * After first calling fdt_first_subnode(), call this function repeatedly to
210  * get direct subnodes of a parent node.
211  *
212  * Return: offset of next subnode, or -FDT_ERR_NOTFOUND if there are no more
213  *         subnodes
214  */
215 int fdt_next_subnode(const void *fdt, int offset);
216 
217 /**
218  * fdt_for_each_subnode - iterate over all subnodes of a parent
219  *
220  * @node:	child node (int, lvalue)
221  * @fdt:	FDT blob (const void *)
222  * @parent:	parent node (int)
223  *
224  * This is actually a wrapper around a for loop and would be used like so:
225  *
226  *	fdt_for_each_subnode(node, fdt, parent) {
227  *		Use node
228  *		...
229  *	}
230  *
231  *	if ((node < 0) && (node != -FDT_ERR_NOTFOUND)) {
232  *		Error handling
233  *	}
234  *
235  * Note that this is implemented as a macro and @node is used as
236  * iterator in the loop. The parent variable be constant or even a
237  * literal.
238  */
239 #define fdt_for_each_subnode(node, fdt, parent)		\
240 	for (node = fdt_first_subnode(fdt, parent);	\
241 	     node >= 0;					\
242 	     node = fdt_next_subnode(fdt, node))
243 
244 /**********************************************************************/
245 /* General functions                                                  */
246 /**********************************************************************/
247 #define fdt_get_header(fdt, field) \
248 	(fdt32_ld(&((const struct fdt_header *)(fdt))->field))
249 #define fdt_magic(fdt)			(fdt_get_header(fdt, magic))
250 #define fdt_totalsize(fdt)		(fdt_get_header(fdt, totalsize))
251 #define fdt_off_dt_struct(fdt)		(fdt_get_header(fdt, off_dt_struct))
252 #define fdt_off_dt_strings(fdt)		(fdt_get_header(fdt, off_dt_strings))
253 #define fdt_off_mem_rsvmap(fdt)		(fdt_get_header(fdt, off_mem_rsvmap))
254 #define fdt_version(fdt)		(fdt_get_header(fdt, version))
255 #define fdt_last_comp_version(fdt)	(fdt_get_header(fdt, last_comp_version))
256 #define fdt_boot_cpuid_phys(fdt)	(fdt_get_header(fdt, boot_cpuid_phys))
257 #define fdt_size_dt_strings(fdt)	(fdt_get_header(fdt, size_dt_strings))
258 #define fdt_size_dt_struct(fdt)		(fdt_get_header(fdt, size_dt_struct))
259 
260 #define fdt_set_hdr_(name) \
261 	static inline void fdt_set_##name(void *fdt, uint32_t val) \
262 	{ \
263 		struct fdt_header *fdth = (struct fdt_header *)fdt; \
264 		fdth->name = cpu_to_fdt32(val); \
265 	}
266 fdt_set_hdr_(magic);
267 fdt_set_hdr_(totalsize);
268 fdt_set_hdr_(off_dt_struct);
269 fdt_set_hdr_(off_dt_strings);
270 fdt_set_hdr_(off_mem_rsvmap);
271 fdt_set_hdr_(version);
272 fdt_set_hdr_(last_comp_version);
273 fdt_set_hdr_(boot_cpuid_phys);
274 fdt_set_hdr_(size_dt_strings);
275 fdt_set_hdr_(size_dt_struct);
276 #undef fdt_set_hdr_
277 
278 /**
279  * fdt_header_size - return the size of the tree's header
280  * @fdt: pointer to a flattened device tree
281  *
282  * Return: size of DTB header in bytes
283  */
284 size_t fdt_header_size(const void *fdt);
285 
286 /**
287  * fdt_header_size_ - internal function to get header size from a version number
288  * @version: devicetree version number
289  *
290  * Return: size of DTB header in bytes
291  */
292 size_t fdt_header_size_(uint32_t version);
293 
294 /**
295  * fdt_check_header - sanity check a device tree header
296  * @fdt: pointer to data which might be a flattened device tree
297  *
298  * fdt_check_header() checks that the given buffer contains what
299  * appears to be a flattened device tree, and that the header contains
300  * valid information (to the extent that can be determined from the
301  * header alone).
302  *
303  * returns:
304  *     0, if the buffer appears to contain a valid device tree
305  *     -FDT_ERR_BADMAGIC,
306  *     -FDT_ERR_BADVERSION,
307  *     -FDT_ERR_BADSTATE,
308  *     -FDT_ERR_TRUNCATED, standard meanings, as above
309  */
310 int fdt_check_header(const void *fdt);
311 
312 /**
313  * fdt_move - move a device tree around in memory
314  * @fdt: pointer to the device tree to move
315  * @buf: pointer to memory where the device is to be moved
316  * @bufsize: size of the memory space at buf
317  *
318  * fdt_move() relocates, if possible, the device tree blob located at
319  * fdt to the buffer at buf of size bufsize.  The buffer may overlap
320  * with the existing device tree blob at fdt.  Therefore,
321  *     fdt_move(fdt, fdt, fdt_totalsize(fdt))
322  * should always succeed.
323  *
324  * returns:
325  *     0, on success
326  *     -FDT_ERR_NOSPACE, bufsize is insufficient to contain the device tree
327  *     -FDT_ERR_BADMAGIC,
328  *     -FDT_ERR_BADVERSION,
329  *     -FDT_ERR_BADSTATE, standard meanings
330  */
331 int fdt_move(const void *fdt, void *buf, int bufsize);
332 
333 /**********************************************************************/
334 /* Read-only functions                                                */
335 /**********************************************************************/
336 
337 int fdt_check_full(const void *fdt, size_t bufsize);
338 
339 /**
340  * fdt_get_string - retrieve a string from the strings block of a device tree
341  * @fdt: pointer to the device tree blob
342  * @stroffset: offset of the string within the strings block (native endian)
343  * @lenp: optional pointer to return the string's length
344  *
345  * fdt_get_string() retrieves a pointer to a single string from the
346  * strings block of the device tree blob at fdt, and optionally also
347  * returns the string's length in *lenp.
348  *
349  * returns:
350  *     a pointer to the string, on success
351  *     NULL, if stroffset is out of bounds, or doesn't point to a valid string
352  */
353 const char *fdt_get_string(const void *fdt, int stroffset, int *lenp);
354 
355 /**
356  * fdt_string - retrieve a string from the strings block of a device tree
357  * @fdt: pointer to the device tree blob
358  * @stroffset: offset of the string within the strings block (native endian)
359  *
360  * fdt_string() retrieves a pointer to a single string from the
361  * strings block of the device tree blob at fdt.
362  *
363  * returns:
364  *     a pointer to the string, on success
365  *     NULL, if stroffset is out of bounds, or doesn't point to a valid string
366  */
367 const char *fdt_string(const void *fdt, int stroffset);
368 
369 /**
370  * fdt_find_max_phandle - find and return the highest phandle in a tree
371  * @fdt: pointer to the device tree blob
372  * @phandle: return location for the highest phandle value found in the tree
373  *
374  * fdt_find_max_phandle() finds the highest phandle value in the given device
375  * tree. The value returned in @phandle is only valid if the function returns
376  * success.
377  *
378  * returns:
379  *     0 on success or a negative error code on failure
380  */
381 int fdt_find_max_phandle(const void *fdt, uint32_t *phandle);
382 
383 /**
384  * fdt_get_max_phandle - retrieves the highest phandle in a tree
385  * @fdt: pointer to the device tree blob
386  *
387  * fdt_get_max_phandle retrieves the highest phandle in the given
388  * device tree. This will ignore badly formatted phandles, or phandles
389  * with a value of 0 or -1.
390  *
391  * This function is deprecated in favour of fdt_find_max_phandle().
392  *
393  * returns:
394  *      the highest phandle on success
395  *      0, if no phandle was found in the device tree
396  *      -1, if an error occurred
397  */
fdt_get_max_phandle(const void * fdt)398 static inline uint32_t fdt_get_max_phandle(const void *fdt)
399 {
400 	uint32_t phandle;
401 	int err;
402 
403 	err = fdt_find_max_phandle(fdt, &phandle);
404 	if (err < 0)
405 		return (uint32_t)-1;
406 
407 	return phandle;
408 }
409 
410 /**
411  * fdt_generate_phandle - return a new, unused phandle for a device tree blob
412  * @fdt: pointer to the device tree blob
413  * @phandle: return location for the new phandle
414  *
415  * Walks the device tree blob and looks for the highest phandle value. On
416  * success, the new, unused phandle value (one higher than the previously
417  * highest phandle value in the device tree blob) will be returned in the
418  * @phandle parameter.
419  *
420  * Return: 0 on success or a negative error-code on failure
421  */
422 int fdt_generate_phandle(const void *fdt, uint32_t *phandle);
423 
424 /**
425  * fdt_num_mem_rsv - retrieve the number of memory reserve map entries
426  * @fdt: pointer to the device tree blob
427  *
428  * Returns the number of entries in the device tree blob's memory
429  * reservation map.  This does not include the terminating 0,0 entry
430  * or any other (0,0) entries reserved for expansion.
431  *
432  * returns:
433  *     the number of entries
434  */
435 int fdt_num_mem_rsv(const void *fdt);
436 
437 /**
438  * fdt_get_mem_rsv - retrieve one memory reserve map entry
439  * @fdt: pointer to the device tree blob
440  * @n: index of reserve map entry
441  * @address: pointer to 64-bit variable to hold the start address
442  * @size: pointer to 64-bit variable to hold the size of the entry
443  *
444  * On success, @address and @size will contain the address and size of
445  * the n-th reserve map entry from the device tree blob, in
446  * native-endian format.
447  *
448  * returns:
449  *     0, on success
450  *     -FDT_ERR_BADMAGIC,
451  *     -FDT_ERR_BADVERSION,
452  *     -FDT_ERR_BADSTATE, standard meanings
453  */
454 int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size);
455 
456 /**
457  * fdt_subnode_offset_namelen - find a subnode based on substring
458  * @fdt: pointer to the device tree blob
459  * @parentoffset: structure block offset of a node
460  * @name: name of the subnode to locate
461  * @namelen: number of characters of name to consider
462  *
463  * Identical to fdt_subnode_offset(), but only examine the first
464  * namelen characters of name for matching the subnode name.  This is
465  * useful for finding subnodes based on a portion of a larger string,
466  * such as a full path.
467  *
468  * Return: offset of the subnode or -FDT_ERR_NOTFOUND if name not found.
469  */
470 #ifndef SWIG /* Not available in Python */
471 int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
472 			       const char *name, int namelen);
473 #endif
474 /**
475  * fdt_subnode_offset - find a subnode of a given node
476  * @fdt: pointer to the device tree blob
477  * @parentoffset: structure block offset of a node
478  * @name: name of the subnode to locate
479  *
480  * fdt_subnode_offset() finds a subnode of the node at structure block
481  * offset parentoffset with the given name.  name may include a unit
482  * address, in which case fdt_subnode_offset() will find the subnode
483  * with that unit address, or the unit address may be omitted, in
484  * which case fdt_subnode_offset() will find an arbitrary subnode
485  * whose name excluding unit address matches the given name.
486  *
487  * returns:
488  *	structure block offset of the requested subnode (>=0), on success
489  *	-FDT_ERR_NOTFOUND, if the requested subnode does not exist
490  *	-FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE
491  *		tag
492  *	-FDT_ERR_BADMAGIC,
493  *	-FDT_ERR_BADVERSION,
494  *	-FDT_ERR_BADSTATE,
495  *	-FDT_ERR_BADSTRUCTURE,
496  *	-FDT_ERR_TRUNCATED, standard meanings.
497  */
498 int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name);
499 
500 /**
501  * fdt_path_offset_namelen - find a tree node by its full path
502  * @fdt: pointer to the device tree blob
503  * @path: full path of the node to locate
504  * @namelen: number of characters of path to consider
505  *
506  * Identical to fdt_path_offset(), but only consider the first namelen
507  * characters of path as the path name.
508  *
509  * Return: offset of the node or negative libfdt error value otherwise
510  */
511 #ifndef SWIG /* Not available in Python */
512 int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen);
513 #endif
514 
515 /**
516  * fdt_path_offset - find a tree node by its full path
517  * @fdt: pointer to the device tree blob
518  * @path: full path of the node to locate
519  *
520  * fdt_path_offset() finds a node of a given path in the device tree.
521  * Each path component may omit the unit address portion, but the
522  * results of this are undefined if any such path component is
523  * ambiguous (that is if there are multiple nodes at the relevant
524  * level matching the given component, differentiated only by unit
525  * address).
526  *
527  * returns:
528  *	structure block offset of the node with the requested path (>=0), on
529  *		success
530  *	-FDT_ERR_BADPATH, given path does not begin with '/' or is invalid
531  *	-FDT_ERR_NOTFOUND, if the requested node does not exist
532  *      -FDT_ERR_BADMAGIC,
533  *	-FDT_ERR_BADVERSION,
534  *	-FDT_ERR_BADSTATE,
535  *	-FDT_ERR_BADSTRUCTURE,
536  *	-FDT_ERR_TRUNCATED, standard meanings.
537  */
538 int fdt_path_offset(const void *fdt, const char *path);
539 
540 /**
541  * fdt_get_name - retrieve the name of a given node
542  * @fdt: pointer to the device tree blob
543  * @nodeoffset: structure block offset of the starting node
544  * @lenp: pointer to an integer variable (will be overwritten) or NULL
545  *
546  * fdt_get_name() retrieves the name (including unit address) of the
547  * device tree node at structure block offset nodeoffset.  If lenp is
548  * non-NULL, the length of this name is also returned, in the integer
549  * pointed to by lenp.
550  *
551  * returns:
552  *	pointer to the node's name, on success
553  *		If lenp is non-NULL, *lenp contains the length of that name
554  *			(>=0)
555  *	NULL, on error
556  *		if lenp is non-NULL *lenp contains an error code (<0):
557  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE
558  *			tag
559  *		-FDT_ERR_BADMAGIC,
560  *		-FDT_ERR_BADVERSION,
561  *		-FDT_ERR_BADSTATE, standard meanings
562  */
563 const char *fdt_get_name(const void *fdt, int nodeoffset, int *lenp);
564 
565 /**
566  * fdt_first_property_offset - find the offset of a node's first property
567  * @fdt: pointer to the device tree blob
568  * @nodeoffset: structure block offset of a node
569  *
570  * fdt_first_property_offset() finds the first property of the node at
571  * the given structure block offset.
572  *
573  * returns:
574  *	structure block offset of the property (>=0), on success
575  *	-FDT_ERR_NOTFOUND, if the requested node has no properties
576  *	-FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_BEGIN_NODE tag
577  *      -FDT_ERR_BADMAGIC,
578  *	-FDT_ERR_BADVERSION,
579  *	-FDT_ERR_BADSTATE,
580  *	-FDT_ERR_BADSTRUCTURE,
581  *	-FDT_ERR_TRUNCATED, standard meanings.
582  */
583 int fdt_first_property_offset(const void *fdt, int nodeoffset);
584 
585 /**
586  * fdt_next_property_offset - step through a node's properties
587  * @fdt: pointer to the device tree blob
588  * @offset: structure block offset of a property
589  *
590  * fdt_next_property_offset() finds the property immediately after the
591  * one at the given structure block offset.  This will be a property
592  * of the same node as the given property.
593  *
594  * returns:
595  *	structure block offset of the next property (>=0), on success
596  *	-FDT_ERR_NOTFOUND, if the given property is the last in its node
597  *	-FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_PROP tag
598  *      -FDT_ERR_BADMAGIC,
599  *	-FDT_ERR_BADVERSION,
600  *	-FDT_ERR_BADSTATE,
601  *	-FDT_ERR_BADSTRUCTURE,
602  *	-FDT_ERR_TRUNCATED, standard meanings.
603  */
604 int fdt_next_property_offset(const void *fdt, int offset);
605 
606 /**
607  * fdt_for_each_property_offset - iterate over all properties of a node
608  *
609  * @property:	property offset (int, lvalue)
610  * @fdt:	FDT blob (const void *)
611  * @node:	node offset (int)
612  *
613  * This is actually a wrapper around a for loop and would be used like so:
614  *
615  *	fdt_for_each_property_offset(property, fdt, node) {
616  *		Use property
617  *		...
618  *	}
619  *
620  *	if ((property < 0) && (property != -FDT_ERR_NOTFOUND)) {
621  *		Error handling
622  *	}
623  *
624  * Note that this is implemented as a macro and property is used as
625  * iterator in the loop. The node variable can be constant or even a
626  * literal.
627  */
628 #define fdt_for_each_property_offset(property, fdt, node)	\
629 	for (property = fdt_first_property_offset(fdt, node);	\
630 	     property >= 0;					\
631 	     property = fdt_next_property_offset(fdt, property))
632 
633 /**
634  * fdt_get_property_by_offset - retrieve the property at a given offset
635  * @fdt: pointer to the device tree blob
636  * @offset: offset of the property to retrieve
637  * @lenp: pointer to an integer variable (will be overwritten) or NULL
638  *
639  * fdt_get_property_by_offset() retrieves a pointer to the
640  * fdt_property structure within the device tree blob at the given
641  * offset.  If lenp is non-NULL, the length of the property value is
642  * also returned, in the integer pointed to by lenp.
643  *
644  * Note that this code only works on device tree versions >= 16. fdt_getprop()
645  * works on all versions.
646  *
647  * returns:
648  *	pointer to the structure representing the property
649  *		if lenp is non-NULL, *lenp contains the length of the property
650  *		value (>=0)
651  *	NULL, on error
652  *		if lenp is non-NULL, *lenp contains an error code (<0):
653  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
654  *		-FDT_ERR_BADMAGIC,
655  *		-FDT_ERR_BADVERSION,
656  *		-FDT_ERR_BADSTATE,
657  *		-FDT_ERR_BADSTRUCTURE,
658  *		-FDT_ERR_TRUNCATED, standard meanings
659  */
660 const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
661 						      int offset,
662 						      int *lenp);
663 
664 /**
665  * fdt_get_property_namelen - find a property based on substring
666  * @fdt: pointer to the device tree blob
667  * @nodeoffset: offset of the node whose property to find
668  * @name: name of the property to find
669  * @namelen: number of characters of name to consider
670  * @lenp: pointer to an integer variable (will be overwritten) or NULL
671  *
672  * Identical to fdt_get_property(), but only examine the first namelen
673  * characters of name for matching the property name.
674  *
675  * Return: pointer to the structure representing the property, or NULL
676  *         if not found
677  */
678 #ifndef SWIG /* Not available in Python */
679 const struct fdt_property *fdt_get_property_namelen(const void *fdt,
680 						    int nodeoffset,
681 						    const char *name,
682 						    int namelen, int *lenp);
683 #endif
684 
685 /**
686  * fdt_get_property - find a given property in a given node
687  * @fdt: pointer to the device tree blob
688  * @nodeoffset: offset of the node whose property to find
689  * @name: name of the property to find
690  * @lenp: pointer to an integer variable (will be overwritten) or NULL
691  *
692  * fdt_get_property() retrieves a pointer to the fdt_property
693  * structure within the device tree blob corresponding to the property
694  * named 'name' of the node at offset nodeoffset.  If lenp is
695  * non-NULL, the length of the property value is also returned, in the
696  * integer pointed to by lenp.
697  *
698  * returns:
699  *	pointer to the structure representing the property
700  *		if lenp is non-NULL, *lenp contains the length of the property
701  *		value (>=0)
702  *	NULL, on error
703  *		if lenp is non-NULL, *lenp contains an error code (<0):
704  *		-FDT_ERR_NOTFOUND, node does not have named property
705  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE
706  *			tag
707  *		-FDT_ERR_BADMAGIC,
708  *		-FDT_ERR_BADVERSION,
709  *		-FDT_ERR_BADSTATE,
710  *		-FDT_ERR_BADSTRUCTURE,
711  *		-FDT_ERR_TRUNCATED, standard meanings
712  */
713 const struct fdt_property *fdt_get_property(const void *fdt, int nodeoffset,
714 					    const char *name, int *lenp);
fdt_get_property_w(void * fdt,int nodeoffset,const char * name,int * lenp)715 static inline struct fdt_property *fdt_get_property_w(void *fdt, int nodeoffset,
716 						      const char *name,
717 						      int *lenp)
718 {
719 	return (struct fdt_property *)(uintptr_t)
720 		fdt_get_property(fdt, nodeoffset, name, lenp);
721 }
722 
723 /**
724  * fdt_getprop_by_offset - retrieve the value of a property at a given offset
725  * @fdt: pointer to the device tree blob
726  * @offset: offset of the property to read
727  * @namep: pointer to a string variable (will be overwritten) or NULL
728  * @lenp: pointer to an integer variable (will be overwritten) or NULL
729  *
730  * fdt_getprop_by_offset() retrieves a pointer to the value of the
731  * property at structure block offset 'offset' (this will be a pointer
732  * to within the device blob itself, not a copy of the value).  If
733  * lenp is non-NULL, the length of the property value is also
734  * returned, in the integer pointed to by lenp.  If namep is non-NULL,
735  * the property's namne will also be returned in the char * pointed to
736  * by namep (this will be a pointer to within the device tree's string
737  * block, not a new copy of the name).
738  *
739  * returns:
740  *	pointer to the property's value
741  *		if lenp is non-NULL, *lenp contains the length of the property
742  *		value (>=0)
743  *		if namep is non-NULL *namep contiains a pointer to the property
744  *		name.
745  *	NULL, on error
746  *		if lenp is non-NULL, *lenp contains an error code (<0):
747  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
748  *		-FDT_ERR_BADMAGIC,
749  *		-FDT_ERR_BADVERSION,
750  *		-FDT_ERR_BADSTATE,
751  *		-FDT_ERR_BADSTRUCTURE,
752  *		-FDT_ERR_TRUNCATED, standard meanings
753  */
754 #ifndef SWIG /* This function is not useful in Python */
755 const void *fdt_getprop_by_offset(const void *fdt, int offset,
756 				  const char **namep, int *lenp);
757 #endif
758 
759 /**
760  * fdt_getprop_namelen - get property value based on substring
761  * @fdt: pointer to the device tree blob
762  * @nodeoffset: offset of the node whose property to find
763  * @name: name of the property to find
764  * @namelen: number of characters of name to consider
765  * @lenp: pointer to an integer variable (will be overwritten) or NULL
766  *
767  * Identical to fdt_getprop(), but only examine the first namelen
768  * characters of name for matching the property name.
769  *
770  * Return: pointer to the property's value or NULL on error
771  */
772 #ifndef SWIG /* Not available in Python */
773 const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
774 				const char *name, int namelen, int *lenp);
fdt_getprop_namelen_w(void * fdt,int nodeoffset,const char * name,int namelen,int * lenp)775 static inline void *fdt_getprop_namelen_w(void *fdt, int nodeoffset,
776 					  const char *name, int namelen,
777 					  int *lenp)
778 {
779 	return (void *)(uintptr_t)fdt_getprop_namelen(fdt, nodeoffset, name,
780 						      namelen, lenp);
781 }
782 #endif
783 
784 /**
785  * fdt_getprop - retrieve the value of a given property
786  * @fdt: pointer to the device tree blob
787  * @nodeoffset: offset of the node whose property to find
788  * @name: name of the property to find
789  * @lenp: pointer to an integer variable (will be overwritten) or NULL
790  *
791  * fdt_getprop() retrieves a pointer to the value of the property
792  * named @name of the node at offset @nodeoffset (this will be a
793  * pointer to within the device blob itself, not a copy of the value).
794  * If @lenp is non-NULL, the length of the property value is also
795  * returned, in the integer pointed to by @lenp.
796  *
797  * returns:
798  *	pointer to the property's value
799  *		if lenp is non-NULL, *lenp contains the length of the property
800  *		value (>=0)
801  *	NULL, on error
802  *		if lenp is non-NULL, *lenp contains an error code (<0):
803  *		-FDT_ERR_NOTFOUND, node does not have named property
804  *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE
805  *			tag
806  *		-FDT_ERR_BADMAGIC,
807  *		-FDT_ERR_BADVERSION,
808  *		-FDT_ERR_BADSTATE,
809  *		-FDT_ERR_BADSTRUCTURE,
810  *		-FDT_ERR_TRUNCATED, standard meanings
811  */
812 const void *fdt_getprop(const void *fdt, int nodeoffset,
813 			const char *name, int *lenp);
fdt_getprop_w(void * fdt,int nodeoffset,const char * name,int * lenp)814 static inline void *fdt_getprop_w(void *fdt, int nodeoffset,
815 				  const char *name, int *lenp)
816 {
817 	return (void *)(uintptr_t)fdt_getprop(fdt, nodeoffset, name, lenp);
818 }
819 
820 /**
821  * fdt_get_phandle - retrieve the phandle of a given node
822  * @fdt: pointer to the device tree blob
823  * @nodeoffset: structure block offset of the node
824  *
825  * fdt_get_phandle() retrieves the phandle of the device tree node at
826  * structure block offset nodeoffset.
827  *
828  * returns:
829  *	the phandle of the node at nodeoffset, on success (!= 0, != -1)
830  *	0, if the node has no phandle, or another error occurs
831  */
832 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset);
833 
834 /**
835  * fdt_get_alias_namelen - get alias based on substring
836  * @fdt: pointer to the device tree blob
837  * @name: name of the alias th look up
838  * @namelen: number of characters of name to consider
839  *
840  * Identical to fdt_get_alias(), but only examine the first @namelen
841  * characters of @name for matching the alias name.
842  *
843  * Return: a pointer to the expansion of the alias named @name, if it exists,
844  *	   NULL otherwise
845  */
846 #ifndef SWIG /* Not available in Python */
847 const char *fdt_get_alias_namelen(const void *fdt,
848 				  const char *name, int namelen);
849 #endif
850 
851 /**
852  * fdt_get_alias - retrieve the path referenced by a given alias
853  * @fdt: pointer to the device tree blob
854  * @name: name of the alias th look up
855  *
856  * fdt_get_alias() retrieves the value of a given alias.  That is, the
857  * value of the property named @name in the node /aliases.
858  *
859  * returns:
860  *	a pointer to the expansion of the alias named 'name', if it exists
861  *	NULL, if the given alias or the /aliases node does not exist
862  */
863 const char *fdt_get_alias(const void *fdt, const char *name);
864 
865 /**
866  * fdt_get_path - determine the full path of a node
867  * @fdt: pointer to the device tree blob
868  * @nodeoffset: offset of the node whose path to find
869  * @buf: character buffer to contain the returned path (will be overwritten)
870  * @buflen: size of the character buffer at buf
871  *
872  * fdt_get_path() computes the full path of the node at offset
873  * nodeoffset, and records that path in the buffer at buf.
874  *
875  * NOTE: This function is expensive, as it must scan the device tree
876  * structure from the start to nodeoffset.
877  *
878  * returns:
879  *	0, on success
880  *		buf contains the absolute path of the node at
881  *		nodeoffset, as a NUL-terminated string.
882  *	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
883  *	-FDT_ERR_NOSPACE, the path of the given node is longer than (bufsize-1)
884  *		characters and will not fit in the given buffer.
885  *	-FDT_ERR_BADMAGIC,
886  *	-FDT_ERR_BADVERSION,
887  *	-FDT_ERR_BADSTATE,
888  *	-FDT_ERR_BADSTRUCTURE, standard meanings
889  */
890 int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen);
891 
892 /**
893  * fdt_supernode_atdepth_offset - find a specific ancestor of a node
894  * @fdt: pointer to the device tree blob
895  * @nodeoffset: offset of the node whose parent to find
896  * @supernodedepth: depth of the ancestor to find
897  * @nodedepth: pointer to an integer variable (will be overwritten) or NULL
898  *
899  * fdt_supernode_atdepth_offset() finds an ancestor of the given node
900  * at a specific depth from the root (where the root itself has depth
901  * 0, its immediate subnodes depth 1 and so forth).  So
902  *	fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, NULL);
903  * will always return 0, the offset of the root node.  If the node at
904  * nodeoffset has depth D, then:
905  *	fdt_supernode_atdepth_offset(fdt, nodeoffset, D, NULL);
906  * will return nodeoffset itself.
907  *
908  * NOTE: This function is expensive, as it must scan the device tree
909  * structure from the start to nodeoffset.
910  *
911  * returns:
912  *	structure block offset of the node at node offset's ancestor
913  *		of depth supernodedepth (>=0), on success
914  *	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
915  *	-FDT_ERR_NOTFOUND, supernodedepth was greater than the depth of
916  *		nodeoffset
917  *	-FDT_ERR_BADMAGIC,
918  *	-FDT_ERR_BADVERSION,
919  *	-FDT_ERR_BADSTATE,
920  *	-FDT_ERR_BADSTRUCTURE, standard meanings
921  */
922 int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
923 				 int supernodedepth, int *nodedepth);
924 
925 /**
926  * fdt_node_depth - find the depth of a given node
927  * @fdt: pointer to the device tree blob
928  * @nodeoffset: offset of the node whose parent to find
929  *
930  * fdt_node_depth() finds the depth of a given node.  The root node
931  * has depth 0, its immediate subnodes depth 1 and so forth.
932  *
933  * NOTE: This function is expensive, as it must scan the device tree
934  * structure from the start to nodeoffset.
935  *
936  * returns:
937  *	depth of the node at nodeoffset (>=0), on success
938  *	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
939  *	-FDT_ERR_BADMAGIC,
940  *	-FDT_ERR_BADVERSION,
941  *	-FDT_ERR_BADSTATE,
942  *	-FDT_ERR_BADSTRUCTURE, standard meanings
943  */
944 int fdt_node_depth(const void *fdt, int nodeoffset);
945 
946 /**
947  * fdt_parent_offset - find the parent of a given node
948  * @fdt: pointer to the device tree blob
949  * @nodeoffset: offset of the node whose parent to find
950  *
951  * fdt_parent_offset() locates the parent node of a given node (that
952  * is, it finds the offset of the node which contains the node at
953  * nodeoffset as a subnode).
954  *
955  * NOTE: This function is expensive, as it must scan the device tree
956  * structure from the start to nodeoffset, *twice*.
957  *
958  * returns:
959  *	structure block offset of the parent of the node at nodeoffset
960  *		(>=0), on success
961  *	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
962  *	-FDT_ERR_BADMAGIC,
963  *	-FDT_ERR_BADVERSION,
964  *	-FDT_ERR_BADSTATE,
965  *	-FDT_ERR_BADSTRUCTURE, standard meanings
966  */
967 int fdt_parent_offset(const void *fdt, int nodeoffset);
968 
969 /**
970  * fdt_node_offset_by_prop_value - find nodes with a given property value
971  * @fdt: pointer to the device tree blob
972  * @startoffset: only find nodes after this offset
973  * @propname: property name to check
974  * @propval: property value to search for
975  * @proplen: length of the value in propval
976  *
977  * fdt_node_offset_by_prop_value() returns the offset of the first
978  * node after startoffset, which has a property named propname whose
979  * value is of length proplen and has value equal to propval; or if
980  * startoffset is -1, the very first such node in the tree.
981  *
982  * To iterate through all nodes matching the criterion, the following
983  * idiom can be used:
984  *	offset = fdt_node_offset_by_prop_value(fdt, -1, propname,
985  *					       propval, proplen);
986  *	while (offset != -FDT_ERR_NOTFOUND) {
987  *		// other code here
988  *		offset = fdt_node_offset_by_prop_value(fdt, offset, propname,
989  *						       propval, proplen);
990  *	}
991  *
992  * Note the -1 in the first call to the function, if 0 is used here
993  * instead, the function will never locate the root node, even if it
994  * matches the criterion.
995  *
996  * returns:
997  *	structure block offset of the located node (>= 0, >startoffset),
998  *		 on success
999  *	-FDT_ERR_NOTFOUND, no node matching the criterion exists in the
1000  *		tree after startoffset
1001  *	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
1002  *	-FDT_ERR_BADMAGIC,
1003  *	-FDT_ERR_BADVERSION,
1004  *	-FDT_ERR_BADSTATE,
1005  *	-FDT_ERR_BADSTRUCTURE, standard meanings
1006  */
1007 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
1008 				  const char *propname,
1009 				  const void *propval, int proplen);
1010 
1011 /**
1012  * fdt_node_offset_by_phandle - find the node with a given phandle
1013  * @fdt: pointer to the device tree blob
1014  * @phandle: phandle value
1015  *
1016  * fdt_node_offset_by_phandle() returns the offset of the node
1017  * which has the given phandle value.  If there is more than one node
1018  * in the tree with the given phandle (an invalid tree), results are
1019  * undefined.
1020  *
1021  * returns:
1022  *	structure block offset of the located node (>= 0), on success
1023  *	-FDT_ERR_NOTFOUND, no node with that phandle exists
1024  *	-FDT_ERR_BADPHANDLE, given phandle value was invalid (0 or -1)
1025  *	-FDT_ERR_BADMAGIC,
1026  *	-FDT_ERR_BADVERSION,
1027  *	-FDT_ERR_BADSTATE,
1028  *	-FDT_ERR_BADSTRUCTURE, standard meanings
1029  */
1030 int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle);
1031 
1032 /**
1033  * fdt_node_check_compatible - check a node's compatible property
1034  * @fdt: pointer to the device tree blob
1035  * @nodeoffset: offset of a tree node
1036  * @compatible: string to match against
1037  *
1038  * fdt_node_check_compatible() returns 0 if the given node contains a
1039  * @compatible property with the given string as one of its elements,
1040  * it returns non-zero otherwise, or on error.
1041  *
1042  * returns:
1043  *	0, if the node has a 'compatible' property listing the given string
1044  *	1, if the node has a 'compatible' property, but it does not list
1045  *		the given string
1046  *	-FDT_ERR_NOTFOUND, if the given node has no 'compatible' property
1047  *	-FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag
1048  *	-FDT_ERR_BADMAGIC,
1049  *	-FDT_ERR_BADVERSION,
1050  *	-FDT_ERR_BADSTATE,
1051  *	-FDT_ERR_BADSTRUCTURE, standard meanings
1052  */
1053 int fdt_node_check_compatible(const void *fdt, int nodeoffset,
1054 			      const char *compatible);
1055 
1056 /**
1057  * fdt_node_offset_by_compatible - find nodes with a given 'compatible' value
1058  * @fdt: pointer to the device tree blob
1059  * @startoffset: only find nodes after this offset
1060  * @compatible: 'compatible' string to match against
1061  *
1062  * fdt_node_offset_by_compatible() returns the offset of the first
1063  * node after startoffset, which has a 'compatible' property which
1064  * lists the given compatible string; or if startoffset is -1, the
1065  * very first such node in the tree.
1066  *
1067  * To iterate through all nodes matching the criterion, the following
1068  * idiom can be used:
1069  *	offset = fdt_node_offset_by_compatible(fdt, -1, compatible);
1070  *	while (offset != -FDT_ERR_NOTFOUND) {
1071  *		// other code here
1072  *		offset = fdt_node_offset_by_compatible(fdt, offset, compatible);
1073  *	}
1074  *
1075  * Note the -1 in the first call to the function, if 0 is used here
1076  * instead, the function will never locate the root node, even if it
1077  * matches the criterion.
1078  *
1079  * returns:
1080  *	structure block offset of the located node (>= 0, >startoffset),
1081  *		 on success
1082  *	-FDT_ERR_NOTFOUND, no node matching the criterion exists in the
1083  *		tree after startoffset
1084  *	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
1085  *	-FDT_ERR_BADMAGIC,
1086  *	-FDT_ERR_BADVERSION,
1087  *	-FDT_ERR_BADSTATE,
1088  *	-FDT_ERR_BADSTRUCTURE, standard meanings
1089  */
1090 int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
1091 				  const char *compatible);
1092 
1093 /**
1094  * fdt_stringlist_contains - check a string list property for a string
1095  * @strlist: Property containing a list of strings to check
1096  * @listlen: Length of property
1097  * @str: String to search for
1098  *
1099  * This is a utility function provided for convenience. The list contains
1100  * one or more strings, each terminated by \0, as is found in a device tree
1101  * "compatible" property.
1102  *
1103  * Return: 1 if the string is found in the list, 0 not found, or invalid list
1104  */
1105 int fdt_stringlist_contains(const char *strlist, int listlen, const char *str);
1106 
1107 /**
1108  * fdt_stringlist_count - count the number of strings in a string list
1109  * @fdt: pointer to the device tree blob
1110  * @nodeoffset: offset of a tree node
1111  * @property: name of the property containing the string list
1112  *
1113  * Return:
1114  *   the number of strings in the given property
1115  *   -FDT_ERR_BADVALUE if the property value is not NUL-terminated
1116  *   -FDT_ERR_NOTFOUND if the property does not exist
1117  */
1118 int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property);
1119 
1120 /**
1121  * fdt_stringlist_search - find a string in a string list and return its index
1122  * @fdt: pointer to the device tree blob
1123  * @nodeoffset: offset of a tree node
1124  * @property: name of the property containing the string list
1125  * @string: string to look up in the string list
1126  *
1127  * Note that it is possible for this function to succeed on property values
1128  * that are not NUL-terminated. That's because the function will stop after
1129  * finding the first occurrence of @string. This can for example happen with
1130  * small-valued cell properties, such as #address-cells, when searching for
1131  * the empty string.
1132  *
1133  * return:
1134  *   the index of the string in the list of strings
1135  *   -FDT_ERR_BADVALUE if the property value is not NUL-terminated
1136  *   -FDT_ERR_NOTFOUND if the property does not exist or does not contain
1137  *                     the given string
1138  */
1139 int fdt_stringlist_search(const void *fdt, int nodeoffset, const char *property,
1140 			  const char *string);
1141 
1142 /**
1143  * fdt_stringlist_get() - obtain the string at a given index in a string list
1144  * @fdt: pointer to the device tree blob
1145  * @nodeoffset: offset of a tree node
1146  * @property: name of the property containing the string list
1147  * @index: index of the string to return
1148  * @lenp: return location for the string length or an error code on failure
1149  *
1150  * Note that this will successfully extract strings from properties with
1151  * non-NUL-terminated values. For example on small-valued cell properties
1152  * this function will return the empty string.
1153  *
1154  * If non-NULL, the length of the string (on success) or a negative error-code
1155  * (on failure) will be stored in the integer pointer to by lenp.
1156  *
1157  * Return:
1158  *   A pointer to the string at the given index in the string list or NULL on
1159  *   failure. On success the length of the string will be stored in the memory
1160  *   location pointed to by the lenp parameter, if non-NULL. On failure one of
1161  *   the following negative error codes will be returned in the lenp parameter
1162  *   (if non-NULL):
1163  *     -FDT_ERR_BADVALUE if the property value is not NUL-terminated
1164  *     -FDT_ERR_NOTFOUND if the property does not exist
1165  */
1166 const char *fdt_stringlist_get(const void *fdt, int nodeoffset,
1167 			       const char *property, int index,
1168 			       int *lenp);
1169 
1170 /**********************************************************************/
1171 /* Read-only functions (addressing related)                           */
1172 /**********************************************************************/
1173 
1174 /**
1175  * FDT_MAX_NCELLS - maximum value for #address-cells and #size-cells
1176  *
1177  * This is the maximum value for #address-cells, #size-cells and
1178  * similar properties that will be processed by libfdt.  IEE1275
1179  * requires that OF implementations handle values up to 4.
1180  * Implementations may support larger values, but in practice higher
1181  * values aren't used.
1182  */
1183 #define FDT_MAX_NCELLS		4
1184 
1185 /**
1186  * fdt_address_cells - retrieve address size for a bus represented in the tree
1187  * @fdt: pointer to the device tree blob
1188  * @nodeoffset: offset of the node to find the address size for
1189  *
1190  * When the node has a valid #address-cells property, returns its value.
1191  *
1192  * returns:
1193  *	0 <= n < FDT_MAX_NCELLS, on success
1194  *      2, if the node has no #address-cells property
1195  *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
1196  *		#address-cells property
1197  *	-FDT_ERR_BADMAGIC,
1198  *	-FDT_ERR_BADVERSION,
1199  *	-FDT_ERR_BADSTATE,
1200  *	-FDT_ERR_BADSTRUCTURE,
1201  *	-FDT_ERR_TRUNCATED, standard meanings
1202  */
1203 int fdt_address_cells(const void *fdt, int nodeoffset);
1204 
1205 /**
1206  * fdt_size_cells - retrieve address range size for a bus represented in the
1207  *                  tree
1208  * @fdt: pointer to the device tree blob
1209  * @nodeoffset: offset of the node to find the address range size for
1210  *
1211  * When the node has a valid #size-cells property, returns its value.
1212  *
1213  * returns:
1214  *	0 <= n < FDT_MAX_NCELLS, on success
1215  *      1, if the node has no #size-cells property
1216  *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
1217  *		#size-cells property
1218  *	-FDT_ERR_BADMAGIC,
1219  *	-FDT_ERR_BADVERSION,
1220  *	-FDT_ERR_BADSTATE,
1221  *	-FDT_ERR_BADSTRUCTURE,
1222  *	-FDT_ERR_TRUNCATED, standard meanings
1223  */
1224 int fdt_size_cells(const void *fdt, int nodeoffset);
1225 
1226 
1227 /**********************************************************************/
1228 /* Write-in-place functions                                           */
1229 /**********************************************************************/
1230 
1231 /**
1232  * fdt_setprop_inplace_namelen_partial - change a property's value,
1233  *                                       but not its size
1234  * @fdt: pointer to the device tree blob
1235  * @nodeoffset: offset of the node whose property to change
1236  * @name: name of the property to change
1237  * @namelen: number of characters of name to consider
1238  * @idx: index of the property to change in the array
1239  * @val: pointer to data to replace the property value with
1240  * @len: length of the property value
1241  *
1242  * Identical to fdt_setprop_inplace(), but modifies the given property
1243  * starting from the given index, and using only the first characters
1244  * of the name. It is useful when you want to manipulate only one value of
1245  * an array and you have a string that doesn't end with \0.
1246  *
1247  * Return: 0 on success, negative libfdt error value otherwise
1248  */
1249 #ifndef SWIG /* Not available in Python */
1250 int fdt_setprop_inplace_namelen_partial(void *fdt, int nodeoffset,
1251 					const char *name, int namelen,
1252 					uint32_t idx, const void *val,
1253 					int len);
1254 #endif
1255 
1256 /**
1257  * fdt_setprop_inplace - change a property's value, but not its size
1258  * @fdt: pointer to the device tree blob
1259  * @nodeoffset: offset of the node whose property to change
1260  * @name: name of the property to change
1261  * @val: pointer to data to replace the property value with
1262  * @len: length of the property value
1263  *
1264  * fdt_setprop_inplace() replaces the value of a given property with
1265  * the data in val, of length len.  This function cannot change the
1266  * size of a property, and so will only work if len is equal to the
1267  * current length of the property.
1268  *
1269  * This function will alter only the bytes in the blob which contain
1270  * the given property value, and will not alter or move any other part
1271  * of the tree.
1272  *
1273  * returns:
1274  *	0, on success
1275  *	-FDT_ERR_NOSPACE, if len is not equal to the property's current length
1276  *	-FDT_ERR_NOTFOUND, node does not have the named property
1277  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1278  *	-FDT_ERR_BADMAGIC,
1279  *	-FDT_ERR_BADVERSION,
1280  *	-FDT_ERR_BADSTATE,
1281  *	-FDT_ERR_BADSTRUCTURE,
1282  *	-FDT_ERR_TRUNCATED, standard meanings
1283  */
1284 #ifndef SWIG /* Not available in Python */
1285 int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
1286 			const void *val, int len);
1287 #endif
1288 
1289 /**
1290  * fdt_setprop_inplace_u32 - change the value of a 32-bit integer property
1291  * @fdt: pointer to the device tree blob
1292  * @nodeoffset: offset of the node whose property to change
1293  * @name: name of the property to change
1294  * @val: 32-bit integer value to replace the property with
1295  *
1296  * fdt_setprop_inplace_u32() replaces the value of a given property
1297  * with the 32-bit integer value in val, converting val to big-endian
1298  * if necessary.  This function cannot change the size of a property,
1299  * and so will only work if the property already exists and has length
1300  * 4.
1301  *
1302  * This function will alter only the bytes in the blob which contain
1303  * the given property value, and will not alter or move any other part
1304  * of the tree.
1305  *
1306  * returns:
1307  *	0, on success
1308  *	-FDT_ERR_NOSPACE, if the property's length is not equal to 4
1309  *	-FDT_ERR_NOTFOUND, node does not have the named property
1310  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1311  *	-FDT_ERR_BADMAGIC,
1312  *	-FDT_ERR_BADVERSION,
1313  *	-FDT_ERR_BADSTATE,
1314  *	-FDT_ERR_BADSTRUCTURE,
1315  *	-FDT_ERR_TRUNCATED, standard meanings
1316  */
fdt_setprop_inplace_u32(void * fdt,int nodeoffset,const char * name,uint32_t val)1317 static inline int fdt_setprop_inplace_u32(void *fdt, int nodeoffset,
1318 					  const char *name, uint32_t val)
1319 {
1320 	fdt32_t tmp = cpu_to_fdt32(val);
1321 	return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1322 }
1323 
1324 /**
1325  * fdt_setprop_inplace_u64 - change the value of a 64-bit integer property
1326  * @fdt: pointer to the device tree blob
1327  * @nodeoffset: offset of the node whose property to change
1328  * @name: name of the property to change
1329  * @val: 64-bit integer value to replace the property with
1330  *
1331  * fdt_setprop_inplace_u64() replaces the value of a given property
1332  * with the 64-bit integer value in val, converting val to big-endian
1333  * if necessary.  This function cannot change the size of a property,
1334  * and so will only work if the property already exists and has length
1335  * 8.
1336  *
1337  * This function will alter only the bytes in the blob which contain
1338  * the given property value, and will not alter or move any other part
1339  * of the tree.
1340  *
1341  * returns:
1342  *	0, on success
1343  *	-FDT_ERR_NOSPACE, if the property's length is not equal to 8
1344  *	-FDT_ERR_NOTFOUND, node does not have the named property
1345  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1346  *	-FDT_ERR_BADMAGIC,
1347  *	-FDT_ERR_BADVERSION,
1348  *	-FDT_ERR_BADSTATE,
1349  *	-FDT_ERR_BADSTRUCTURE,
1350  *	-FDT_ERR_TRUNCATED, standard meanings
1351  */
fdt_setprop_inplace_u64(void * fdt,int nodeoffset,const char * name,uint64_t val)1352 static inline int fdt_setprop_inplace_u64(void *fdt, int nodeoffset,
1353 					  const char *name, uint64_t val)
1354 {
1355 	fdt64_t tmp = cpu_to_fdt64(val);
1356 	return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1357 }
1358 
1359 /**
1360  * fdt_setprop_inplace_cell - change the value of a single-cell property
1361  * @fdt: pointer to the device tree blob
1362  * @nodeoffset: offset of the node containing the property
1363  * @name: name of the property to change the value of
1364  * @val: new value of the 32-bit cell
1365  *
1366  * This is an alternative name for fdt_setprop_inplace_u32()
1367  * Return: 0 on success, negative libfdt error number otherwise.
1368  */
fdt_setprop_inplace_cell(void * fdt,int nodeoffset,const char * name,uint32_t val)1369 static inline int fdt_setprop_inplace_cell(void *fdt, int nodeoffset,
1370 					   const char *name, uint32_t val)
1371 {
1372 	return fdt_setprop_inplace_u32(fdt, nodeoffset, name, val);
1373 }
1374 
1375 /**
1376  * fdt_nop_property - replace a property with nop tags
1377  * @fdt: pointer to the device tree blob
1378  * @nodeoffset: offset of the node whose property to nop
1379  * @name: name of the property to nop
1380  *
1381  * fdt_nop_property() will replace a given property's representation
1382  * in the blob with FDT_NOP tags, effectively removing it from the
1383  * tree.
1384  *
1385  * This function will alter only the bytes in the blob which contain
1386  * the property, and will not alter or move any other part of the
1387  * tree.
1388  *
1389  * returns:
1390  *	0, on success
1391  *	-FDT_ERR_NOTFOUND, node does not have the named property
1392  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1393  *	-FDT_ERR_BADMAGIC,
1394  *	-FDT_ERR_BADVERSION,
1395  *	-FDT_ERR_BADSTATE,
1396  *	-FDT_ERR_BADSTRUCTURE,
1397  *	-FDT_ERR_TRUNCATED, standard meanings
1398  */
1399 int fdt_nop_property(void *fdt, int nodeoffset, const char *name);
1400 
1401 /**
1402  * fdt_nop_node - replace a node (subtree) with nop tags
1403  * @fdt: pointer to the device tree blob
1404  * @nodeoffset: offset of the node to nop
1405  *
1406  * fdt_nop_node() will replace a given node's representation in the
1407  * blob, including all its subnodes, if any, with FDT_NOP tags,
1408  * effectively removing it from the tree.
1409  *
1410  * This function will alter only the bytes in the blob which contain
1411  * the node and its properties and subnodes, and will not alter or
1412  * move any other part of the tree.
1413  *
1414  * returns:
1415  *	0, on success
1416  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1417  *	-FDT_ERR_BADMAGIC,
1418  *	-FDT_ERR_BADVERSION,
1419  *	-FDT_ERR_BADSTATE,
1420  *	-FDT_ERR_BADSTRUCTURE,
1421  *	-FDT_ERR_TRUNCATED, standard meanings
1422  */
1423 int fdt_nop_node(void *fdt, int nodeoffset);
1424 
1425 /**********************************************************************/
1426 /* Sequential write functions                                         */
1427 /**********************************************************************/
1428 
1429 /* fdt_create_with_flags flags */
1430 #define FDT_CREATE_FLAG_NO_NAME_DEDUP 0x1
1431 	/* FDT_CREATE_FLAG_NO_NAME_DEDUP: Do not try to de-duplicate property
1432 	 * names in the fdt. This can result in faster creation times, but
1433 	 * a larger fdt. */
1434 
1435 #define FDT_CREATE_FLAGS_ALL	(FDT_CREATE_FLAG_NO_NAME_DEDUP)
1436 
1437 /**
1438  * fdt_create_with_flags - begin creation of a new fdt
1439  * @buf: pointer to memory allocated where fdt will be created
1440  * @bufsize: size of the memory space at fdt
1441  * @flags: a valid combination of FDT_CREATE_FLAG_ flags, or 0.
1442  *
1443  * fdt_create_with_flags() begins the process of creating a new fdt with
1444  * the sequential write interface.
1445  *
1446  * fdt creation process must end with fdt_finished() to produce a valid fdt.
1447  *
1448  * returns:
1449  *	0, on success
1450  *	-FDT_ERR_NOSPACE, bufsize is insufficient for a minimal fdt
1451  *	-FDT_ERR_BADFLAGS, flags is not valid
1452  */
1453 int fdt_create_with_flags(void *buf, int bufsize, uint32_t flags);
1454 
1455 /**
1456  * fdt_create - begin creation of a new fdt
1457  * @buf: pointer to memory allocated where fdt will be created
1458  * @bufsize: size of the memory space at fdt
1459  *
1460  * fdt_create() is equivalent to fdt_create_with_flags() with flags=0.
1461  *
1462  * returns:
1463  *	0, on success
1464  *	-FDT_ERR_NOSPACE, bufsize is insufficient for a minimal fdt
1465  */
1466 int fdt_create(void *buf, int bufsize);
1467 
1468 int fdt_resize(void *fdt, void *buf, int bufsize);
1469 int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size);
1470 int fdt_finish_reservemap(void *fdt);
1471 int fdt_begin_node(void *fdt, const char *name);
1472 int fdt_property(void *fdt, const char *name, const void *val, int len);
fdt_property_u32(void * fdt,const char * name,uint32_t val)1473 static inline int fdt_property_u32(void *fdt, const char *name, uint32_t val)
1474 {
1475 	fdt32_t tmp = cpu_to_fdt32(val);
1476 	return fdt_property(fdt, name, &tmp, sizeof(tmp));
1477 }
fdt_property_u64(void * fdt,const char * name,uint64_t val)1478 static inline int fdt_property_u64(void *fdt, const char *name, uint64_t val)
1479 {
1480 	fdt64_t tmp = cpu_to_fdt64(val);
1481 	return fdt_property(fdt, name, &tmp, sizeof(tmp));
1482 }
1483 
1484 #ifndef SWIG /* Not available in Python */
fdt_property_cell(void * fdt,const char * name,uint32_t val)1485 static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val)
1486 {
1487 	return fdt_property_u32(fdt, name, val);
1488 }
1489 #endif
1490 
1491 /**
1492  * fdt_property_placeholder - add a new property and return a ptr to its value
1493  *
1494  * @fdt: pointer to the device tree blob
1495  * @name: name of property to add
1496  * @len: length of property value in bytes
1497  * @valp: returns a pointer to where where the value should be placed
1498  *
1499  * returns:
1500  *	0, on success
1501  *	-FDT_ERR_BADMAGIC,
1502  *	-FDT_ERR_NOSPACE, standard meanings
1503  */
1504 int fdt_property_placeholder(void *fdt, const char *name, int len, void **valp);
1505 
1506 #define fdt_property_string(fdt, name, str) \
1507 	fdt_property(fdt, name, str, strlen(str)+1)
1508 int fdt_end_node(void *fdt);
1509 int fdt_finish(void *fdt);
1510 
1511 /**********************************************************************/
1512 /* Read-write functions                                               */
1513 /**********************************************************************/
1514 
1515 int fdt_create_empty_tree(void *buf, int bufsize);
1516 int fdt_open_into(const void *fdt, void *buf, int bufsize);
1517 int fdt_pack(void *fdt);
1518 
1519 /**
1520  * fdt_add_mem_rsv - add one memory reserve map entry
1521  * @fdt: pointer to the device tree blob
1522  * @address: 64-bit start address of the reserve map entry
1523  * @size: 64-bit size of the reserved region
1524  *
1525  * Adds a reserve map entry to the given blob reserving a region at
1526  * address address of length size.
1527  *
1528  * This function will insert data into the reserve map and will
1529  * therefore change the indexes of some entries in the table.
1530  *
1531  * returns:
1532  *	0, on success
1533  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1534  *		contain the new reservation entry
1535  *	-FDT_ERR_BADMAGIC,
1536  *	-FDT_ERR_BADVERSION,
1537  *	-FDT_ERR_BADSTATE,
1538  *	-FDT_ERR_BADSTRUCTURE,
1539  *	-FDT_ERR_BADLAYOUT,
1540  *	-FDT_ERR_TRUNCATED, standard meanings
1541  */
1542 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size);
1543 
1544 /**
1545  * fdt_del_mem_rsv - remove a memory reserve map entry
1546  * @fdt: pointer to the device tree blob
1547  * @n: entry to remove
1548  *
1549  * fdt_del_mem_rsv() removes the n-th memory reserve map entry from
1550  * the blob.
1551  *
1552  * This function will delete data from the reservation table and will
1553  * therefore change the indexes of some entries in the table.
1554  *
1555  * returns:
1556  *	0, on success
1557  *	-FDT_ERR_NOTFOUND, there is no entry of the given index (i.e. there
1558  *		are less than n+1 reserve map entries)
1559  *	-FDT_ERR_BADMAGIC,
1560  *	-FDT_ERR_BADVERSION,
1561  *	-FDT_ERR_BADSTATE,
1562  *	-FDT_ERR_BADSTRUCTURE,
1563  *	-FDT_ERR_BADLAYOUT,
1564  *	-FDT_ERR_TRUNCATED, standard meanings
1565  */
1566 int fdt_del_mem_rsv(void *fdt, int n);
1567 
1568 /**
1569  * fdt_set_name - change the name of a given node
1570  * @fdt: pointer to the device tree blob
1571  * @nodeoffset: structure block offset of a node
1572  * @name: name to give the node
1573  *
1574  * fdt_set_name() replaces the name (including unit address, if any)
1575  * of the given node with the given string.  NOTE: this function can't
1576  * efficiently check if the new name is unique amongst the given
1577  * node's siblings; results are undefined if this function is invoked
1578  * with a name equal to one of the given node's siblings.
1579  *
1580  * This function may insert or delete data from the blob, and will
1581  * therefore change the offsets of some existing nodes.
1582  *
1583  * returns:
1584  *	0, on success
1585  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob
1586  *		to contain the new name
1587  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1588  *	-FDT_ERR_BADMAGIC,
1589  *	-FDT_ERR_BADVERSION,
1590  *	-FDT_ERR_BADSTATE, standard meanings
1591  */
1592 int fdt_set_name(void *fdt, int nodeoffset, const char *name);
1593 
1594 /**
1595  * fdt_setprop - create or change a property
1596  * @fdt: pointer to the device tree blob
1597  * @nodeoffset: offset of the node whose property to change
1598  * @name: name of the property to change
1599  * @val: pointer to data to set the property value to
1600  * @len: length of the property value
1601  *
1602  * fdt_setprop() sets the value of the named property in the given
1603  * node to the given value and length, creating the property if it
1604  * does not already exist.
1605  *
1606  * This function may insert or delete data from the blob, and will
1607  * therefore change the offsets of some existing nodes.
1608  *
1609  * returns:
1610  *	0, on success
1611  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1612  *		contain the new property value
1613  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1614  *	-FDT_ERR_BADLAYOUT,
1615  *	-FDT_ERR_BADMAGIC,
1616  *	-FDT_ERR_BADVERSION,
1617  *	-FDT_ERR_BADSTATE,
1618  *	-FDT_ERR_BADSTRUCTURE,
1619  *	-FDT_ERR_BADLAYOUT,
1620  *	-FDT_ERR_TRUNCATED, standard meanings
1621  */
1622 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
1623 		const void *val, int len);
1624 
1625 /**
1626  * fdt_setprop_placeholder - allocate space for a property
1627  * @fdt: pointer to the device tree blob
1628  * @nodeoffset: offset of the node whose property to change
1629  * @name: name of the property to change
1630  * @len: length of the property value
1631  * @prop_data: return pointer to property data
1632  *
1633  * fdt_setprop_placeholer() allocates the named property in the given node.
1634  * If the property exists it is resized. In either case a pointer to the
1635  * property data is returned.
1636  *
1637  * This function may insert or delete data from the blob, and will
1638  * therefore change the offsets of some existing nodes.
1639  *
1640  * returns:
1641  *	0, on success
1642  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1643  *		contain the new property value
1644  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1645  *	-FDT_ERR_BADLAYOUT,
1646  *	-FDT_ERR_BADMAGIC,
1647  *	-FDT_ERR_BADVERSION,
1648  *	-FDT_ERR_BADSTATE,
1649  *	-FDT_ERR_BADSTRUCTURE,
1650  *	-FDT_ERR_BADLAYOUT,
1651  *	-FDT_ERR_TRUNCATED, standard meanings
1652  */
1653 int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name,
1654 			    int len, void **prop_data);
1655 
1656 /**
1657  * fdt_setprop_u32 - set a property to a 32-bit integer
1658  * @fdt: pointer to the device tree blob
1659  * @nodeoffset: offset of the node whose property to change
1660  * @name: name of the property to change
1661  * @val: 32-bit integer value for the property (native endian)
1662  *
1663  * fdt_setprop_u32() sets the value of the named property in the given
1664  * node to the given 32-bit integer value (converting to big-endian if
1665  * necessary), or creates a new property with that value if it does
1666  * not already exist.
1667  *
1668  * This function may insert or delete data from the blob, and will
1669  * therefore change the offsets of some existing nodes.
1670  *
1671  * returns:
1672  *	0, on success
1673  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1674  *		contain the new property value
1675  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1676  *	-FDT_ERR_BADLAYOUT,
1677  *	-FDT_ERR_BADMAGIC,
1678  *	-FDT_ERR_BADVERSION,
1679  *	-FDT_ERR_BADSTATE,
1680  *	-FDT_ERR_BADSTRUCTURE,
1681  *	-FDT_ERR_BADLAYOUT,
1682  *	-FDT_ERR_TRUNCATED, standard meanings
1683  */
fdt_setprop_u32(void * fdt,int nodeoffset,const char * name,uint32_t val)1684 static inline int fdt_setprop_u32(void *fdt, int nodeoffset, const char *name,
1685 				  uint32_t val)
1686 {
1687 	fdt32_t tmp = cpu_to_fdt32(val);
1688 	return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1689 }
1690 
1691 /**
1692  * fdt_setprop_u64 - set a property to a 64-bit integer
1693  * @fdt: pointer to the device tree blob
1694  * @nodeoffset: offset of the node whose property to change
1695  * @name: name of the property to change
1696  * @val: 64-bit integer value for the property (native endian)
1697  *
1698  * fdt_setprop_u64() sets the value of the named property in the given
1699  * node to the given 64-bit integer value (converting to big-endian if
1700  * necessary), or creates a new property with that value if it does
1701  * not already exist.
1702  *
1703  * This function may insert or delete data from the blob, and will
1704  * therefore change the offsets of some existing nodes.
1705  *
1706  * returns:
1707  *	0, on success
1708  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1709  *		contain the new property value
1710  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1711  *	-FDT_ERR_BADLAYOUT,
1712  *	-FDT_ERR_BADMAGIC,
1713  *	-FDT_ERR_BADVERSION,
1714  *	-FDT_ERR_BADSTATE,
1715  *	-FDT_ERR_BADSTRUCTURE,
1716  *	-FDT_ERR_BADLAYOUT,
1717  *	-FDT_ERR_TRUNCATED, standard meanings
1718  */
fdt_setprop_u64(void * fdt,int nodeoffset,const char * name,uint64_t val)1719 static inline int fdt_setprop_u64(void *fdt, int nodeoffset, const char *name,
1720 				  uint64_t val)
1721 {
1722 	fdt64_t tmp = cpu_to_fdt64(val);
1723 	return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1724 }
1725 
1726 /**
1727  * fdt_setprop_cell - set a property to a single cell value
1728  * @fdt: pointer to the device tree blob
1729  * @nodeoffset: offset of the node whose property to change
1730  * @name: name of the property to change
1731  * @val: 32-bit integer value for the property (native endian)
1732  *
1733  * This is an alternative name for fdt_setprop_u32()
1734  *
1735  * Return: 0 on success, negative libfdt error value otherwise.
1736  */
fdt_setprop_cell(void * fdt,int nodeoffset,const char * name,uint32_t val)1737 static inline int fdt_setprop_cell(void *fdt, int nodeoffset, const char *name,
1738 				   uint32_t val)
1739 {
1740 	return fdt_setprop_u32(fdt, nodeoffset, name, val);
1741 }
1742 
1743 /**
1744  * fdt_setprop_string - set a property to a string value
1745  * @fdt: pointer to the device tree blob
1746  * @nodeoffset: offset of the node whose property to change
1747  * @name: name of the property to change
1748  * @str: string value for the property
1749  *
1750  * fdt_setprop_string() sets the value of the named property in the
1751  * given node to the given string value (using the length of the
1752  * string to determine the new length of the property), or creates a
1753  * new property with that value if it does not already exist.
1754  *
1755  * This function may insert or delete data from the blob, and will
1756  * therefore change the offsets of some existing nodes.
1757  *
1758  * returns:
1759  *	0, on success
1760  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1761  *		contain the new property value
1762  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1763  *	-FDT_ERR_BADLAYOUT,
1764  *	-FDT_ERR_BADMAGIC,
1765  *	-FDT_ERR_BADVERSION,
1766  *	-FDT_ERR_BADSTATE,
1767  *	-FDT_ERR_BADSTRUCTURE,
1768  *	-FDT_ERR_BADLAYOUT,
1769  *	-FDT_ERR_TRUNCATED, standard meanings
1770  */
1771 #define fdt_setprop_string(fdt, nodeoffset, name, str) \
1772 	fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1773 
1774 
1775 /**
1776  * fdt_setprop_empty - set a property to an empty value
1777  * @fdt: pointer to the device tree blob
1778  * @nodeoffset: offset of the node whose property to change
1779  * @name: name of the property to change
1780  *
1781  * fdt_setprop_empty() sets the value of the named property in the
1782  * given node to an empty (zero length) value, or creates a new empty
1783  * property if it does not already exist.
1784  *
1785  * This function may insert or delete data from the blob, and will
1786  * therefore change the offsets of some existing nodes.
1787  *
1788  * returns:
1789  *	0, on success
1790  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1791  *		contain the new property value
1792  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1793  *	-FDT_ERR_BADLAYOUT,
1794  *	-FDT_ERR_BADMAGIC,
1795  *	-FDT_ERR_BADVERSION,
1796  *	-FDT_ERR_BADSTATE,
1797  *	-FDT_ERR_BADSTRUCTURE,
1798  *	-FDT_ERR_BADLAYOUT,
1799  *	-FDT_ERR_TRUNCATED, standard meanings
1800  */
1801 #define fdt_setprop_empty(fdt, nodeoffset, name) \
1802 	fdt_setprop((fdt), (nodeoffset), (name), NULL, 0)
1803 
1804 /**
1805  * fdt_appendprop - append to or create a property
1806  * @fdt: pointer to the device tree blob
1807  * @nodeoffset: offset of the node whose property to change
1808  * @name: name of the property to append to
1809  * @val: pointer to data to append to the property value
1810  * @len: length of the data to append to the property value
1811  *
1812  * fdt_appendprop() appends the value to the named property in the
1813  * given node, creating the property if it does not already exist.
1814  *
1815  * This function may insert data into the blob, and will therefore
1816  * change the offsets of some existing nodes.
1817  *
1818  * returns:
1819  *	0, on success
1820  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1821  *		contain the new property value
1822  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1823  *	-FDT_ERR_BADLAYOUT,
1824  *	-FDT_ERR_BADMAGIC,
1825  *	-FDT_ERR_BADVERSION,
1826  *	-FDT_ERR_BADSTATE,
1827  *	-FDT_ERR_BADSTRUCTURE,
1828  *	-FDT_ERR_BADLAYOUT,
1829  *	-FDT_ERR_TRUNCATED, standard meanings
1830  */
1831 int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
1832 		   const void *val, int len);
1833 
1834 /**
1835  * fdt_appendprop_u32 - append a 32-bit integer value to a property
1836  * @fdt: pointer to the device tree blob
1837  * @nodeoffset: offset of the node whose property to change
1838  * @name: name of the property to change
1839  * @val: 32-bit integer value to append to the property (native endian)
1840  *
1841  * fdt_appendprop_u32() appends the given 32-bit integer value
1842  * (converting to big-endian if necessary) to the value of the named
1843  * property in the given node, or creates a new property with that
1844  * value if it does not already exist.
1845  *
1846  * This function may insert data into the blob, and will therefore
1847  * change the offsets of some existing nodes.
1848  *
1849  * returns:
1850  *	0, on success
1851  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1852  *		contain the new property value
1853  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1854  *	-FDT_ERR_BADLAYOUT,
1855  *	-FDT_ERR_BADMAGIC,
1856  *	-FDT_ERR_BADVERSION,
1857  *	-FDT_ERR_BADSTATE,
1858  *	-FDT_ERR_BADSTRUCTURE,
1859  *	-FDT_ERR_BADLAYOUT,
1860  *	-FDT_ERR_TRUNCATED, standard meanings
1861  */
fdt_appendprop_u32(void * fdt,int nodeoffset,const char * name,uint32_t val)1862 static inline int fdt_appendprop_u32(void *fdt, int nodeoffset,
1863 				     const char *name, uint32_t val)
1864 {
1865 	fdt32_t tmp = cpu_to_fdt32(val);
1866 	return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1867 }
1868 
1869 /**
1870  * fdt_appendprop_u64 - append a 64-bit integer value to a property
1871  * @fdt: pointer to the device tree blob
1872  * @nodeoffset: offset of the node whose property to change
1873  * @name: name of the property to change
1874  * @val: 64-bit integer value to append to the property (native endian)
1875  *
1876  * fdt_appendprop_u64() appends the given 64-bit integer value
1877  * (converting to big-endian if necessary) to the value of the named
1878  * property in the given node, or creates a new property with that
1879  * value if it does not already exist.
1880  *
1881  * This function may insert data into the blob, and will therefore
1882  * change the offsets of some existing nodes.
1883  *
1884  * returns:
1885  *	0, on success
1886  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1887  *		contain the new property value
1888  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1889  *	-FDT_ERR_BADLAYOUT,
1890  *	-FDT_ERR_BADMAGIC,
1891  *	-FDT_ERR_BADVERSION,
1892  *	-FDT_ERR_BADSTATE,
1893  *	-FDT_ERR_BADSTRUCTURE,
1894  *	-FDT_ERR_BADLAYOUT,
1895  *	-FDT_ERR_TRUNCATED, standard meanings
1896  */
fdt_appendprop_u64(void * fdt,int nodeoffset,const char * name,uint64_t val)1897 static inline int fdt_appendprop_u64(void *fdt, int nodeoffset,
1898 				     const char *name, uint64_t val)
1899 {
1900 	fdt64_t tmp = cpu_to_fdt64(val);
1901 	return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1902 }
1903 
1904 /**
1905  * fdt_appendprop_cell - append a single cell value to a property
1906  * @fdt: pointer to the device tree blob
1907  * @nodeoffset: offset of the node whose property to change
1908  * @name: name of the property to change
1909  * @val: 32-bit integer value to append to the property (native endian)
1910  *
1911  * This is an alternative name for fdt_appendprop_u32()
1912  *
1913  * Return: 0 on success, negative libfdt error value otherwise.
1914  */
fdt_appendprop_cell(void * fdt,int nodeoffset,const char * name,uint32_t val)1915 static inline int fdt_appendprop_cell(void *fdt, int nodeoffset,
1916 				      const char *name, uint32_t val)
1917 {
1918 	return fdt_appendprop_u32(fdt, nodeoffset, name, val);
1919 }
1920 
1921 /**
1922  * fdt_appendprop_string - append a string to a property
1923  * @fdt: pointer to the device tree blob
1924  * @nodeoffset: offset of the node whose property to change
1925  * @name: name of the property to change
1926  * @str: string value to append to the property
1927  *
1928  * fdt_appendprop_string() appends the given string to the value of
1929  * the named property in the given node, or creates a new property
1930  * with that value if it does not already exist.
1931  *
1932  * This function may insert data into the blob, and will therefore
1933  * change the offsets of some existing nodes.
1934  *
1935  * returns:
1936  *	0, on success
1937  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1938  *		contain the new property value
1939  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1940  *	-FDT_ERR_BADLAYOUT,
1941  *	-FDT_ERR_BADMAGIC,
1942  *	-FDT_ERR_BADVERSION,
1943  *	-FDT_ERR_BADSTATE,
1944  *	-FDT_ERR_BADSTRUCTURE,
1945  *	-FDT_ERR_BADLAYOUT,
1946  *	-FDT_ERR_TRUNCATED, standard meanings
1947  */
1948 #define fdt_appendprop_string(fdt, nodeoffset, name, str) \
1949 	fdt_appendprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1950 
1951 /**
1952  * fdt_appendprop_addrrange - append a address range property
1953  * @fdt: pointer to the device tree blob
1954  * @parent: offset of the parent node
1955  * @nodeoffset: offset of the node to add a property at
1956  * @name: name of property
1957  * @addr: start address of a given range
1958  * @size: size of a given range
1959  *
1960  * fdt_appendprop_addrrange() appends an address range value (start
1961  * address and size) to the value of the named property in the given
1962  * node, or creates a new property with that value if it does not
1963  * already exist.
1964  * If "name" is not specified, a default "reg" is used.
1965  * Cell sizes are determined by parent's #address-cells and #size-cells.
1966  *
1967  * This function may insert data into the blob, and will therefore
1968  * change the offsets of some existing nodes.
1969  *
1970  * returns:
1971  *	0, on success
1972  *	-FDT_ERR_BADLAYOUT,
1973  *	-FDT_ERR_BADMAGIC,
1974  *	-FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
1975  *		#address-cells property
1976  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1977  *	-FDT_ERR_BADSTATE,
1978  *	-FDT_ERR_BADSTRUCTURE,
1979  *	-FDT_ERR_BADVERSION,
1980  *	-FDT_ERR_BADVALUE, addr or size doesn't fit to respective cells size
1981  *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1982  *		contain a new property
1983  *	-FDT_ERR_TRUNCATED, standard meanings
1984  */
1985 int fdt_appendprop_addrrange(void *fdt, int parent, int nodeoffset,
1986 			     const char *name, uint64_t addr, uint64_t size);
1987 
1988 /**
1989  * fdt_delprop - delete a property
1990  * @fdt: pointer to the device tree blob
1991  * @nodeoffset: offset of the node whose property to nop
1992  * @name: name of the property to nop
1993  *
1994  * fdt_del_property() will delete the given property.
1995  *
1996  * This function will delete data from the blob, and will therefore
1997  * change the offsets of some existing nodes.
1998  *
1999  * returns:
2000  *	0, on success
2001  *	-FDT_ERR_NOTFOUND, node does not have the named property
2002  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
2003  *	-FDT_ERR_BADLAYOUT,
2004  *	-FDT_ERR_BADMAGIC,
2005  *	-FDT_ERR_BADVERSION,
2006  *	-FDT_ERR_BADSTATE,
2007  *	-FDT_ERR_BADSTRUCTURE,
2008  *	-FDT_ERR_TRUNCATED, standard meanings
2009  */
2010 int fdt_delprop(void *fdt, int nodeoffset, const char *name);
2011 
2012 /**
2013  * fdt_add_subnode_namelen - creates a new node based on substring
2014  * @fdt: pointer to the device tree blob
2015  * @parentoffset: structure block offset of a node
2016  * @name: name of the subnode to create
2017  * @namelen: number of characters of name to consider
2018  *
2019  * Identical to fdt_add_subnode(), but use only the first @namelen
2020  * characters of @name as the name of the new node.  This is useful for
2021  * creating subnodes based on a portion of a larger string, such as a
2022  * full path.
2023  *
2024  * Return: structure block offset of the created subnode (>=0),
2025  *	   negative libfdt error value otherwise
2026  */
2027 #ifndef SWIG /* Not available in Python */
2028 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
2029 			    const char *name, int namelen);
2030 #endif
2031 
2032 /**
2033  * fdt_add_subnode - creates a new node
2034  * @fdt: pointer to the device tree blob
2035  * @parentoffset: structure block offset of a node
2036  * @name: name of the subnode to locate
2037  *
2038  * fdt_add_subnode() creates a new node as a subnode of the node at
2039  * structure block offset parentoffset, with the given name (which
2040  * should include the unit address, if any).
2041  *
2042  * This function will insert data into the blob, and will therefore
2043  * change the offsets of some existing nodes.
2044  *
2045  * returns:
2046  *	structure block offset of the created nodeequested subnode (>=0), on
2047  *		success
2048  *	-FDT_ERR_NOTFOUND, if the requested subnode does not exist
2049  *	-FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE
2050  *		tag
2051  *	-FDT_ERR_EXISTS, if the node at parentoffset already has a subnode of
2052  *		the given name
2053  *	-FDT_ERR_NOSPACE, if there is insufficient free space in the
2054  *		blob to contain the new node
2055  *	-FDT_ERR_NOSPACE
2056  *	-FDT_ERR_BADLAYOUT
2057  *      -FDT_ERR_BADMAGIC,
2058  *	-FDT_ERR_BADVERSION,
2059  *	-FDT_ERR_BADSTATE,
2060  *	-FDT_ERR_BADSTRUCTURE,
2061  *	-FDT_ERR_TRUNCATED, standard meanings.
2062  */
2063 int fdt_add_subnode(void *fdt, int parentoffset, const char *name);
2064 
2065 /**
2066  * fdt_del_node - delete a node (subtree)
2067  * @fdt: pointer to the device tree blob
2068  * @nodeoffset: offset of the node to nop
2069  *
2070  * fdt_del_node() will remove the given node, including all its
2071  * subnodes if any, from the blob.
2072  *
2073  * This function will delete data from the blob, and will therefore
2074  * change the offsets of some existing nodes.
2075  *
2076  * returns:
2077  *	0, on success
2078  *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
2079  *	-FDT_ERR_BADLAYOUT,
2080  *	-FDT_ERR_BADMAGIC,
2081  *	-FDT_ERR_BADVERSION,
2082  *	-FDT_ERR_BADSTATE,
2083  *	-FDT_ERR_BADSTRUCTURE,
2084  *	-FDT_ERR_TRUNCATED, standard meanings
2085  */
2086 int fdt_del_node(void *fdt, int nodeoffset);
2087 
2088 /**
2089  * fdt_overlay_apply - Applies a DT overlay on a base DT
2090  * @fdt: pointer to the base device tree blob
2091  * @fdto: pointer to the device tree overlay blob
2092  *
2093  * fdt_overlay_apply() will apply the given device tree overlay on the
2094  * given base device tree.
2095  *
2096  * Expect the base device tree to be modified, even if the function
2097  * returns an error.
2098  *
2099  * returns:
2100  *	0, on success
2101  *	-FDT_ERR_NOSPACE, there's not enough space in the base device tree
2102  *	-FDT_ERR_NOTFOUND, the overlay points to some inexistant nodes or
2103  *		properties in the base DT
2104  *	-FDT_ERR_BADPHANDLE,
2105  *	-FDT_ERR_BADOVERLAY,
2106  *	-FDT_ERR_NOPHANDLES,
2107  *	-FDT_ERR_INTERNAL,
2108  *	-FDT_ERR_BADLAYOUT,
2109  *	-FDT_ERR_BADMAGIC,
2110  *	-FDT_ERR_BADOFFSET,
2111  *	-FDT_ERR_BADPATH,
2112  *	-FDT_ERR_BADVERSION,
2113  *	-FDT_ERR_BADSTRUCTURE,
2114  *	-FDT_ERR_BADSTATE,
2115  *	-FDT_ERR_TRUNCATED, standard meanings
2116  */
2117 int fdt_overlay_apply(void *fdt, void *fdto);
2118 
2119 /**********************************************************************/
2120 /* Debugging / informational functions                                */
2121 /**********************************************************************/
2122 
2123 const char *fdt_strerror(int errval);
2124 
2125 #ifdef __cplusplus
2126 }
2127 #endif
2128 
2129 #endif /* LIBFDT_H */
2130