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1 /*
2  * libfdt - Flat Device Tree manipulation
3  * Copyright (C) 2006 David Gibson, IBM Corporation.
4  *
5  * libfdt is dual licensed: you can use it either under the terms of
6  * the GPL, or the BSD license, at your option.
7  *
8  *  a) This library is free software; you can redistribute it and/or
9  *     modify it under the terms of the GNU General Public License as
10  *     published by the Free Software Foundation; either version 2 of the
11  *     License, or (at your option) any later version.
12  *
13  *     This library is distributed in the hope that it will be useful,
14  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  *     GNU General Public License for more details.
17  *
18  *     You should have received a copy of the GNU General Public
19  *     License along with this library; if not, write to the Free
20  *     Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
21  *     MA 02110-1301 USA
22  *
23  * Alternatively,
24  *
25  *  b) Redistribution and use in source and binary forms, with or
26  *     without modification, are permitted provided that the following
27  *     conditions are met:
28  *
29  *     1. Redistributions of source code must retain the above
30  *        copyright notice, this list of conditions and the following
31  *        disclaimer.
32  *     2. Redistributions in binary form must reproduce the above
33  *        copyright notice, this list of conditions and the following
34  *        disclaimer in the documentation and/or other materials
35  *        provided with the distribution.
36  *
37  *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
38  *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
39  *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
40  *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
41  *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
42  *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
43  *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
44  *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
45  *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
46  *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
47  *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
48  *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
49  *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
50  */
51 #include "libfdt_env.h"
52 
53 #include <fdt.h>
54 #include <libfdt.h>
55 
56 #include "libfdt_internal.h"
57 
_fdt_nodename_eq(const void * fdt,int offset,const char * s,int len)58 static int _fdt_nodename_eq(const void *fdt, int offset,
59 			    const char *s, int len)
60 {
61 	const char *p = fdt_offset_ptr(fdt, offset + FDT_TAGSIZE, len+1);
62 
63 	if (! p)
64 		/* short match */
65 		return 0;
66 
67 	if (memcmp(p, s, len) != 0)
68 		return 0;
69 
70 	if (p[len] == '\0')
71 		return 1;
72 	else if (!memchr(s, '@', len) && (p[len] == '@'))
73 		return 1;
74 	else
75 		return 0;
76 }
77 
fdt_string(const void * fdt,int stroffset)78 const char *fdt_string(const void *fdt, int stroffset)
79 {
80 	return (const char *)fdt + fdt_off_dt_strings(fdt) + stroffset;
81 }
82 
_fdt_string_eq(const void * fdt,int stroffset,const char * s,int len)83 static int _fdt_string_eq(const void *fdt, int stroffset,
84 			  const char *s, int len)
85 {
86 	const char *p = fdt_string(fdt, stroffset);
87 
88 	return (strlen(p) == len) && (memcmp(p, s, len) == 0);
89 }
90 
fdt_get_max_phandle(const void * fdt)91 uint32_t fdt_get_max_phandle(const void *fdt)
92 {
93 	uint32_t max_phandle = 0;
94 	int offset;
95 
96 	for (offset = fdt_next_node(fdt, -1, NULL);;
97 	     offset = fdt_next_node(fdt, offset, NULL)) {
98 		uint32_t phandle;
99 
100 		if (offset == -FDT_ERR_NOTFOUND)
101 			return max_phandle;
102 
103 		if (offset < 0)
104 			return (uint32_t)-1;
105 
106 		phandle = fdt_get_phandle(fdt, offset);
107 		if (phandle == (uint32_t)-1)
108 			continue;
109 
110 		if (phandle > max_phandle)
111 			max_phandle = phandle;
112 	}
113 
114 	return 0;
115 }
116 
fdt_get_mem_rsv(const void * fdt,int n,uint64_t * address,uint64_t * size)117 int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size)
118 {
119 	FDT_CHECK_HEADER(fdt);
120 	*address = fdt64_to_cpu(_fdt_mem_rsv(fdt, n)->address);
121 	*size = fdt64_to_cpu(_fdt_mem_rsv(fdt, n)->size);
122 	return 0;
123 }
124 
fdt_num_mem_rsv(const void * fdt)125 int fdt_num_mem_rsv(const void *fdt)
126 {
127 	int i = 0;
128 
129 	while (fdt64_to_cpu(_fdt_mem_rsv(fdt, i)->size) != 0)
130 		i++;
131 	return i;
132 }
133 
_nextprop(const void * fdt,int offset)134 static int _nextprop(const void *fdt, int offset)
135 {
136 	uint32_t tag;
137 	int nextoffset;
138 
139 	do {
140 		tag = fdt_next_tag(fdt, offset, &nextoffset);
141 
142 		switch (tag) {
143 		case FDT_END:
144 			if (nextoffset >= 0)
145 				return -FDT_ERR_BADSTRUCTURE;
146 			else
147 				return nextoffset;
148 
149 		case FDT_PROP:
150 			return offset;
151 		}
152 		offset = nextoffset;
153 	} while (tag == FDT_NOP);
154 
155 	return -FDT_ERR_NOTFOUND;
156 }
157 
fdt_subnode_offset_namelen(const void * fdt,int offset,const char * name,int namelen)158 int fdt_subnode_offset_namelen(const void *fdt, int offset,
159 			       const char *name, int namelen)
160 {
161 	int depth;
162 
163 	FDT_CHECK_HEADER(fdt);
164 
165 	for (depth = 0;
166 	     (offset >= 0) && (depth >= 0);
167 	     offset = fdt_next_node(fdt, offset, &depth))
168 		if ((depth == 1)
169 		    && _fdt_nodename_eq(fdt, offset, name, namelen))
170 			return offset;
171 
172 	if (depth < 0)
173 		return -FDT_ERR_NOTFOUND;
174 	return offset; /* error */
175 }
176 
fdt_subnode_offset(const void * fdt,int parentoffset,const char * name)177 int fdt_subnode_offset(const void *fdt, int parentoffset,
178 		       const char *name)
179 {
180 	return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name));
181 }
182 
fdt_path_offset_namelen(const void * fdt,const char * path,int namelen)183 int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen)
184 {
185 	const char *end = path + namelen;
186 	const char *p = path;
187 	int offset = 0;
188 
189 	FDT_CHECK_HEADER(fdt);
190 
191 	/* see if we have an alias */
192 	if (*path != '/') {
193 		const char *q = memchr(path, '/', end - p);
194 
195 		if (!q)
196 			q = end;
197 
198 		p = fdt_get_alias_namelen(fdt, p, q - p);
199 		if (!p)
200 			return -FDT_ERR_BADPATH;
201 		offset = fdt_path_offset(fdt, p);
202 
203 		p = q;
204 	}
205 
206 	while (p < end) {
207 		const char *q;
208 
209 		while (*p == '/') {
210 			p++;
211 			if (p == end)
212 				return offset;
213 		}
214 		q = memchr(p, '/', end - p);
215 		if (! q)
216 			q = end;
217 
218 		offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p);
219 		if (offset < 0)
220 			return offset;
221 
222 		p = q;
223 	}
224 
225 	return offset;
226 }
227 
fdt_path_offset(const void * fdt,const char * path)228 int fdt_path_offset(const void *fdt, const char *path)
229 {
230 	return fdt_path_offset_namelen(fdt, path, strlen(path));
231 }
232 
fdt_get_name(const void * fdt,int nodeoffset,int * len)233 const char *fdt_get_name(const void *fdt, int nodeoffset, int *len)
234 {
235 	const struct fdt_node_header *nh = _fdt_offset_ptr(fdt, nodeoffset);
236 	int err;
237 
238 	if (((err = fdt_check_header(fdt)) != 0)
239 	    || ((err = _fdt_check_node_offset(fdt, nodeoffset)) < 0))
240 			goto fail;
241 
242 	if (len)
243 		*len = strlen(nh->name);
244 
245 	return nh->name;
246 
247  fail:
248 	if (len)
249 		*len = err;
250 	return NULL;
251 }
252 
fdt_first_property_offset(const void * fdt,int nodeoffset)253 int fdt_first_property_offset(const void *fdt, int nodeoffset)
254 {
255 	int offset;
256 
257 	if ((offset = _fdt_check_node_offset(fdt, nodeoffset)) < 0)
258 		return offset;
259 
260 	return _nextprop(fdt, offset);
261 }
262 
fdt_next_property_offset(const void * fdt,int offset)263 int fdt_next_property_offset(const void *fdt, int offset)
264 {
265 	if ((offset = _fdt_check_prop_offset(fdt, offset)) < 0)
266 		return offset;
267 
268 	return _nextprop(fdt, offset);
269 }
270 
fdt_get_property_by_offset(const void * fdt,int offset,int * lenp)271 const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
272 						      int offset,
273 						      int *lenp)
274 {
275 	int err;
276 	const struct fdt_property *prop;
277 
278 	if ((err = _fdt_check_prop_offset(fdt, offset)) < 0) {
279 		if (lenp)
280 			*lenp = err;
281 		return NULL;
282 	}
283 
284 	prop = _fdt_offset_ptr(fdt, offset);
285 
286 	if (lenp)
287 		*lenp = fdt32_to_cpu(prop->len);
288 
289 	return prop;
290 }
291 
fdt_get_property_namelen(const void * fdt,int offset,const char * name,int namelen,int * lenp)292 const struct fdt_property *fdt_get_property_namelen(const void *fdt,
293 						    int offset,
294 						    const char *name,
295 						    int namelen, int *lenp)
296 {
297 	for (offset = fdt_first_property_offset(fdt, offset);
298 	     (offset >= 0);
299 	     (offset = fdt_next_property_offset(fdt, offset))) {
300 		const struct fdt_property *prop;
301 
302 		if (!(prop = fdt_get_property_by_offset(fdt, offset, lenp))) {
303 			offset = -FDT_ERR_INTERNAL;
304 			break;
305 		}
306 		if (_fdt_string_eq(fdt, fdt32_to_cpu(prop->nameoff),
307 				   name, namelen))
308 			return prop;
309 	}
310 
311 	if (lenp)
312 		*lenp = offset;
313 	return NULL;
314 }
315 
fdt_get_property(const void * fdt,int nodeoffset,const char * name,int * lenp)316 const struct fdt_property *fdt_get_property(const void *fdt,
317 					    int nodeoffset,
318 					    const char *name, int *lenp)
319 {
320 	return fdt_get_property_namelen(fdt, nodeoffset, name,
321 					strlen(name), lenp);
322 }
323 
fdt_getprop_namelen(const void * fdt,int nodeoffset,const char * name,int namelen,int * lenp)324 const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
325 				const char *name, int namelen, int *lenp)
326 {
327 	const struct fdt_property *prop;
328 
329 	prop = fdt_get_property_namelen(fdt, nodeoffset, name, namelen, lenp);
330 	if (! prop)
331 		return NULL;
332 
333 	return prop->data;
334 }
335 
fdt_getprop_by_offset(const void * fdt,int offset,const char ** namep,int * lenp)336 const void *fdt_getprop_by_offset(const void *fdt, int offset,
337 				  const char **namep, int *lenp)
338 {
339 	const struct fdt_property *prop;
340 
341 	prop = fdt_get_property_by_offset(fdt, offset, lenp);
342 	if (!prop)
343 		return NULL;
344 	if (namep)
345 		*namep = fdt_string(fdt, fdt32_to_cpu(prop->nameoff));
346 	return prop->data;
347 }
348 
fdt_getprop(const void * fdt,int nodeoffset,const char * name,int * lenp)349 const void *fdt_getprop(const void *fdt, int nodeoffset,
350 			const char *name, int *lenp)
351 {
352 	return fdt_getprop_namelen(fdt, nodeoffset, name, strlen(name), lenp);
353 }
354 
fdt_get_phandle(const void * fdt,int nodeoffset)355 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
356 {
357 	const fdt32_t *php;
358 	int len;
359 
360 	/* FIXME: This is a bit sub-optimal, since we potentially scan
361 	 * over all the properties twice. */
362 	php = fdt_getprop(fdt, nodeoffset, "phandle", &len);
363 	if (!php || (len != sizeof(*php))) {
364 		php = fdt_getprop(fdt, nodeoffset, "linux,phandle", &len);
365 		if (!php || (len != sizeof(*php)))
366 			return 0;
367 	}
368 
369 	return fdt32_to_cpu(*php);
370 }
371 
fdt_get_alias_namelen(const void * fdt,const char * name,int namelen)372 const char *fdt_get_alias_namelen(const void *fdt,
373 				  const char *name, int namelen)
374 {
375 	int aliasoffset;
376 
377 	aliasoffset = fdt_path_offset(fdt, "/aliases");
378 	if (aliasoffset < 0)
379 		return NULL;
380 
381 	return fdt_getprop_namelen(fdt, aliasoffset, name, namelen, NULL);
382 }
383 
fdt_get_alias(const void * fdt,const char * name)384 const char *fdt_get_alias(const void *fdt, const char *name)
385 {
386 	return fdt_get_alias_namelen(fdt, name, strlen(name));
387 }
388 
fdt_get_path(const void * fdt,int nodeoffset,char * buf,int buflen)389 int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen)
390 {
391 	int pdepth = 0, p = 0;
392 	int offset, depth, namelen;
393 	const char *name;
394 
395 	FDT_CHECK_HEADER(fdt);
396 
397 	if (buflen < 2)
398 		return -FDT_ERR_NOSPACE;
399 
400 	for (offset = 0, depth = 0;
401 	     (offset >= 0) && (offset <= nodeoffset);
402 	     offset = fdt_next_node(fdt, offset, &depth)) {
403 		while (pdepth > depth) {
404 			do {
405 				p--;
406 			} while (buf[p-1] != '/');
407 			pdepth--;
408 		}
409 
410 		if (pdepth >= depth) {
411 			name = fdt_get_name(fdt, offset, &namelen);
412 			if (!name)
413 				return namelen;
414 			if ((p + namelen + 1) <= buflen) {
415 				memcpy(buf + p, name, namelen);
416 				p += namelen;
417 				buf[p++] = '/';
418 				pdepth++;
419 			}
420 		}
421 
422 		if (offset == nodeoffset) {
423 			if (pdepth < (depth + 1))
424 				return -FDT_ERR_NOSPACE;
425 
426 			if (p > 1) /* special case so that root path is "/", not "" */
427 				p--;
428 			buf[p] = '\0';
429 			return 0;
430 		}
431 	}
432 
433 	if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
434 		return -FDT_ERR_BADOFFSET;
435 	else if (offset == -FDT_ERR_BADOFFSET)
436 		return -FDT_ERR_BADSTRUCTURE;
437 
438 	return offset; /* error from fdt_next_node() */
439 }
440 
fdt_supernode_atdepth_offset(const void * fdt,int nodeoffset,int supernodedepth,int * nodedepth)441 int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
442 				 int supernodedepth, int *nodedepth)
443 {
444 	int offset, depth;
445 	int supernodeoffset = -FDT_ERR_INTERNAL;
446 
447 	FDT_CHECK_HEADER(fdt);
448 
449 	if (supernodedepth < 0)
450 		return -FDT_ERR_NOTFOUND;
451 
452 	for (offset = 0, depth = 0;
453 	     (offset >= 0) && (offset <= nodeoffset);
454 	     offset = fdt_next_node(fdt, offset, &depth)) {
455 		if (depth == supernodedepth)
456 			supernodeoffset = offset;
457 
458 		if (offset == nodeoffset) {
459 			if (nodedepth)
460 				*nodedepth = depth;
461 
462 			if (supernodedepth > depth)
463 				return -FDT_ERR_NOTFOUND;
464 			else
465 				return supernodeoffset;
466 		}
467 	}
468 
469 	if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
470 		return -FDT_ERR_BADOFFSET;
471 	else if (offset == -FDT_ERR_BADOFFSET)
472 		return -FDT_ERR_BADSTRUCTURE;
473 
474 	return offset; /* error from fdt_next_node() */
475 }
476 
fdt_node_depth(const void * fdt,int nodeoffset)477 int fdt_node_depth(const void *fdt, int nodeoffset)
478 {
479 	int nodedepth;
480 	int err;
481 
482 	err = fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, &nodedepth);
483 	if (err)
484 		return (err < 0) ? err : -FDT_ERR_INTERNAL;
485 	return nodedepth;
486 }
487 
fdt_parent_offset(const void * fdt,int nodeoffset)488 int fdt_parent_offset(const void *fdt, int nodeoffset)
489 {
490 	int nodedepth = fdt_node_depth(fdt, nodeoffset);
491 
492 	if (nodedepth < 0)
493 		return nodedepth;
494 	return fdt_supernode_atdepth_offset(fdt, nodeoffset,
495 					    nodedepth - 1, NULL);
496 }
497 
fdt_node_offset_by_prop_value(const void * fdt,int startoffset,const char * propname,const void * propval,int proplen)498 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
499 				  const char *propname,
500 				  const void *propval, int proplen)
501 {
502 	int offset;
503 	const void *val;
504 	int len;
505 
506 	FDT_CHECK_HEADER(fdt);
507 
508 	/* FIXME: The algorithm here is pretty horrible: we scan each
509 	 * property of a node in fdt_getprop(), then if that didn't
510 	 * find what we want, we scan over them again making our way
511 	 * to the next node.  Still it's the easiest to implement
512 	 * approach; performance can come later. */
513 	for (offset = fdt_next_node(fdt, startoffset, NULL);
514 	     offset >= 0;
515 	     offset = fdt_next_node(fdt, offset, NULL)) {
516 		val = fdt_getprop(fdt, offset, propname, &len);
517 		if (val && (len == proplen)
518 		    && (memcmp(val, propval, len) == 0))
519 			return offset;
520 	}
521 
522 	return offset; /* error from fdt_next_node() */
523 }
524 
fdt_node_offset_by_phandle(const void * fdt,uint32_t phandle)525 int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle)
526 {
527 	int offset;
528 
529 	if ((phandle == 0) || (phandle == -1))
530 		return -FDT_ERR_BADPHANDLE;
531 
532 	FDT_CHECK_HEADER(fdt);
533 
534 	/* FIXME: The algorithm here is pretty horrible: we
535 	 * potentially scan each property of a node in
536 	 * fdt_get_phandle(), then if that didn't find what
537 	 * we want, we scan over them again making our way to the next
538 	 * node.  Still it's the easiest to implement approach;
539 	 * performance can come later. */
540 	for (offset = fdt_next_node(fdt, -1, NULL);
541 	     offset >= 0;
542 	     offset = fdt_next_node(fdt, offset, NULL)) {
543 		if (fdt_get_phandle(fdt, offset) == phandle)
544 			return offset;
545 	}
546 
547 	return offset; /* error from fdt_next_node() */
548 }
549 
fdt_stringlist_contains(const char * strlist,int listlen,const char * str)550 int fdt_stringlist_contains(const char *strlist, int listlen, const char *str)
551 {
552 	int len = strlen(str);
553 	const char *p;
554 
555 	while (listlen >= len) {
556 		if (memcmp(str, strlist, len+1) == 0)
557 			return 1;
558 		p = memchr(strlist, '\0', listlen);
559 		if (!p)
560 			return 0; /* malformed strlist.. */
561 		listlen -= (p-strlist) + 1;
562 		strlist = p + 1;
563 	}
564 	return 0;
565 }
566 
fdt_stringlist_count(const void * fdt,int nodeoffset,const char * property)567 int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property)
568 {
569 	const char *list, *end;
570 	int length, count = 0;
571 
572 	list = fdt_getprop(fdt, nodeoffset, property, &length);
573 	if (!list)
574 		return -length;
575 
576 	end = list + length;
577 
578 	while (list < end) {
579 		length = strnlen(list, end - list) + 1;
580 
581 		/* Abort if the last string isn't properly NUL-terminated. */
582 		if (list + length > end)
583 			return -FDT_ERR_BADVALUE;
584 
585 		list += length;
586 		count++;
587 	}
588 
589 	return count;
590 }
591 
fdt_stringlist_search(const void * fdt,int nodeoffset,const char * property,const char * string)592 int fdt_stringlist_search(const void *fdt, int nodeoffset, const char *property,
593 			  const char *string)
594 {
595 	int length, len, idx = 0;
596 	const char *list, *end;
597 
598 	list = fdt_getprop(fdt, nodeoffset, property, &length);
599 	if (!list)
600 		return -length;
601 
602 	len = strlen(string) + 1;
603 	end = list + length;
604 
605 	while (list < end) {
606 		length = strnlen(list, end - list) + 1;
607 
608 		/* Abort if the last string isn't properly NUL-terminated. */
609 		if (list + length > end)
610 			return -FDT_ERR_BADVALUE;
611 
612 		if (length == len && memcmp(list, string, length) == 0)
613 			return idx;
614 
615 		list += length;
616 		idx++;
617 	}
618 
619 	return -FDT_ERR_NOTFOUND;
620 }
621 
fdt_stringlist_get(const void * fdt,int nodeoffset,const char * property,int idx,int * lenp)622 const char *fdt_stringlist_get(const void *fdt, int nodeoffset,
623 			       const char *property, int idx,
624 			       int *lenp)
625 {
626 	const char *list, *end;
627 	int length;
628 
629 	list = fdt_getprop(fdt, nodeoffset, property, &length);
630 	if (!list) {
631 		if (lenp)
632 			*lenp = length;
633 
634 		return NULL;
635 	}
636 
637 	end = list + length;
638 
639 	while (list < end) {
640 		length = strnlen(list, end - list) + 1;
641 
642 		/* Abort if the last string isn't properly NUL-terminated. */
643 		if (list + length > end) {
644 			if (lenp)
645 				*lenp = -FDT_ERR_BADVALUE;
646 
647 			return NULL;
648 		}
649 
650 		if (idx == 0) {
651 			if (lenp)
652 				*lenp = length - 1;
653 
654 			return list;
655 		}
656 
657 		list += length;
658 		idx--;
659 	}
660 
661 	if (lenp)
662 		*lenp = -FDT_ERR_NOTFOUND;
663 
664 	return NULL;
665 }
666 
fdt_node_check_compatible(const void * fdt,int nodeoffset,const char * compatible)667 int fdt_node_check_compatible(const void *fdt, int nodeoffset,
668 			      const char *compatible)
669 {
670 	const void *prop;
671 	int len;
672 
673 	prop = fdt_getprop(fdt, nodeoffset, "compatible", &len);
674 	if (!prop)
675 		return len;
676 
677 	return !fdt_stringlist_contains(prop, len, compatible);
678 }
679 
fdt_node_offset_by_compatible(const void * fdt,int startoffset,const char * compatible)680 int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
681 				  const char *compatible)
682 {
683 	int offset, err;
684 
685 	FDT_CHECK_HEADER(fdt);
686 
687 	/* FIXME: The algorithm here is pretty horrible: we scan each
688 	 * property of a node in fdt_node_check_compatible(), then if
689 	 * that didn't find what we want, we scan over them again
690 	 * making our way to the next node.  Still it's the easiest to
691 	 * implement approach; performance can come later. */
692 	for (offset = fdt_next_node(fdt, startoffset, NULL);
693 	     offset >= 0;
694 	     offset = fdt_next_node(fdt, offset, NULL)) {
695 		err = fdt_node_check_compatible(fdt, offset, compatible);
696 		if ((err < 0) && (err != -FDT_ERR_NOTFOUND))
697 			return err;
698 		else if (err == 0)
699 			return offset;
700 	}
701 
702 	return offset; /* error from fdt_next_node() */
703 }
704