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v3.1
 
  1/*
  2 * Procedures for creating, accessing and interpreting the device tree.
  3 *
  4 * Paul Mackerras	August 1996.
  5 * Copyright (C) 1996-2005 Paul Mackerras.
  6 *
  7 *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
  8 *    {engebret|bergner}@us.ibm.com
  9 *
 10 *  Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
 11 *
 12 *  Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
 13 *  Grant Likely.
 14 *
 15 *      This program is free software; you can redistribute it and/or
 16 *      modify it under the terms of the GNU General Public License
 17 *      as published by the Free Software Foundation; either version
 18 *      2 of the License, or (at your option) any later version.
 19 */
 
 
 
 
 
 
 20#include <linux/module.h>
 21#include <linux/of.h>
 
 
 22#include <linux/spinlock.h>
 23#include <linux/slab.h>
 
 24#include <linux/proc_fs.h>
 25
 26struct device_node *allnodes;
 
 
 
 
 
 27struct device_node *of_chosen;
 
 
 
 
 28
 29/* use when traversing tree through the allnext, child, sibling,
 
 
 
 
 
 
 
 
 
 
 30 * or parent members of struct device_node.
 31 */
 32DEFINE_RWLOCK(devtree_lock);
 33
 34int of_n_addr_cells(struct device_node *np)
 35{
 36	const __be32 *ip;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 37
 38	do {
 39		if (np->parent)
 40			np = np->parent;
 41		ip = of_get_property(np, "#address-cells", NULL);
 42		if (ip)
 43			return be32_to_cpup(ip);
 44	} while (np->parent);
 45	/* No #address-cells property for the root node */
 46	return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
 47}
 
 
 
 
 
 
 
 
 48EXPORT_SYMBOL(of_n_addr_cells);
 49
 50int of_n_size_cells(struct device_node *np)
 51{
 52	const __be32 *ip;
 
 
 
 
 53
 54	do {
 55		if (np->parent)
 56			np = np->parent;
 57		ip = of_get_property(np, "#size-cells", NULL);
 58		if (ip)
 59			return be32_to_cpup(ip);
 60	} while (np->parent);
 61	/* No #size-cells property for the root node */
 62	return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
 63}
 
 
 
 
 
 
 
 
 64EXPORT_SYMBOL(of_n_size_cells);
 65
 66#if !defined(CONFIG_SPARC)   /* SPARC doesn't do ref counting (yet) */
 67/**
 68 *	of_node_get - Increment refcount of a node
 69 *	@node:	Node to inc refcount, NULL is supported to
 70 *		simplify writing of callers
 71 *
 72 *	Returns node.
 73 */
 74struct device_node *of_node_get(struct device_node *node)
 75{
 76	if (node)
 77		kref_get(&node->kref);
 78	return node;
 79}
 80EXPORT_SYMBOL(of_node_get);
 81
 82static inline struct device_node *kref_to_device_node(struct kref *kref)
 
 
 
 
 
 83{
 84	return container_of(kref, struct device_node, kref);
 85}
 86
 87/**
 88 *	of_node_release - release a dynamically allocated node
 89 *	@kref:  kref element of the node to be released
 90 *
 91 *	In of_node_put() this function is passed to kref_put()
 92 *	as the destructor.
 93 */
 94static void of_node_release(struct kref *kref)
 95{
 96	struct device_node *node = kref_to_device_node(kref);
 97	struct property *prop = node->properties;
 98
 99	/* We should never be releasing nodes that haven't been detached. */
100	if (!of_node_check_flag(node, OF_DETACHED)) {
101		pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name);
102		dump_stack();
103		kref_init(&node->kref);
104		return;
105	}
106
107	if (!of_node_check_flag(node, OF_DYNAMIC))
108		return;
109
110	while (prop) {
111		struct property *next = prop->next;
112		kfree(prop->name);
113		kfree(prop->value);
114		kfree(prop);
115		prop = next;
116
117		if (!prop) {
118			prop = node->deadprops;
119			node->deadprops = NULL;
120		}
121	}
122	kfree(node->full_name);
123	kfree(node->data);
124	kfree(node);
125}
126
127/**
128 *	of_node_put - Decrement refcount of a node
129 *	@node:	Node to dec refcount, NULL is supported to
130 *		simplify writing of callers
131 *
132 */
133void of_node_put(struct device_node *node)
134{
135	if (node)
136		kref_put(&node->kref, of_node_release);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
137}
138EXPORT_SYMBOL(of_node_put);
139#endif /* !CONFIG_SPARC */
140
141struct property *of_find_property(const struct device_node *np,
142				  const char *name,
143				  int *lenp)
144{
145	struct property *pp;
146
147	if (!np)
148		return NULL;
149
150	read_lock(&devtree_lock);
151	for (pp = np->properties; pp != 0; pp = pp->next) {
152		if (of_prop_cmp(pp->name, name) == 0) {
153			if (lenp != 0)
154				*lenp = pp->length;
155			break;
156		}
157	}
158	read_unlock(&devtree_lock);
 
 
 
 
 
 
 
 
 
 
 
 
 
159
160	return pp;
161}
162EXPORT_SYMBOL(of_find_property);
163
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
164/**
165 * of_find_all_nodes - Get next node in global list
166 * @prev:	Previous node or NULL to start iteration
167 *		of_node_put() will be called on it
168 *
169 * Returns a node pointer with refcount incremented, use
170 * of_node_put() on it when done.
171 */
172struct device_node *of_find_all_nodes(struct device_node *prev)
173{
174	struct device_node *np;
 
175
176	read_lock(&devtree_lock);
177	np = prev ? prev->allnext : allnodes;
178	for (; np != NULL; np = np->allnext)
179		if (of_node_get(np))
180			break;
181	of_node_put(prev);
182	read_unlock(&devtree_lock);
183	return np;
184}
185EXPORT_SYMBOL(of_find_all_nodes);
186
187/*
188 * Find a property with a given name for a given node
189 * and return the value.
190 */
 
 
 
 
 
 
 
 
 
 
 
 
191const void *of_get_property(const struct device_node *np, const char *name,
192			 int *lenp)
193{
194	struct property *pp = of_find_property(np, name, lenp);
195
196	return pp ? pp->value : NULL;
197}
198EXPORT_SYMBOL(of_get_property);
199
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
200/** Checks if the given "compat" string matches one of the strings in
201 * the device's "compatible" property
202 */
203int of_device_is_compatible(const struct device_node *device,
204		const char *compat)
205{
206	const char* cp;
207	int cplen, l;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
208
209	cp = of_get_property(device, "compatible", &cplen);
210	if (cp == NULL)
211		return 0;
212	while (cplen > 0) {
213		if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
214			return 1;
215		l = strlen(cp) + 1;
216		cp += l;
217		cplen -= l;
218	}
219
220	return 0;
221}
222EXPORT_SYMBOL(of_device_is_compatible);
223
224/**
225 * of_machine_is_compatible - Test root of device tree for a given compatible value
226 * @compat: compatible string to look for in root node's compatible property.
227 *
228 * Returns true if the root node has the given value in its
229 * compatible property.
230 */
231int of_machine_is_compatible(const char *compat)
232{
233	struct device_node *root;
234	int rc = 0;
235
236	root = of_find_node_by_path("/");
237	if (root) {
238		rc = of_device_is_compatible(root, compat);
239		of_node_put(root);
240	}
241	return rc;
242}
243EXPORT_SYMBOL(of_machine_is_compatible);
244
245/**
246 *  of_device_is_available - check if a device is available for use
247 *
248 *  @device: Node to check for availability
249 *
250 *  Returns 1 if the status property is absent or set to "okay" or "ok",
251 *  0 otherwise
252 */
253int of_device_is_available(const struct device_node *device)
254{
255	const char *status;
256	int statlen;
257
258	status = of_get_property(device, "status", &statlen);
 
 
 
259	if (status == NULL)
260		return 1;
261
262	if (statlen > 0) {
263		if (!strcmp(status, "okay") || !strcmp(status, "ok"))
264			return 1;
265	}
266
267	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
268}
269EXPORT_SYMBOL(of_device_is_available);
270
271/**
272 *	of_get_parent - Get a node's parent if any
273 *	@node:	Node to get parent
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
274 *
275 *	Returns a node pointer with refcount incremented, use
276 *	of_node_put() on it when done.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
277 */
278struct device_node *of_get_parent(const struct device_node *node)
279{
280	struct device_node *np;
 
281
282	if (!node)
283		return NULL;
284
285	read_lock(&devtree_lock);
286	np = of_node_get(node->parent);
287	read_unlock(&devtree_lock);
288	return np;
289}
290EXPORT_SYMBOL(of_get_parent);
291
292/**
293 *	of_get_next_parent - Iterate to a node's parent
294 *	@node:	Node to get parent of
295 *
296 * 	This is like of_get_parent() except that it drops the
297 * 	refcount on the passed node, making it suitable for iterating
298 * 	through a node's parents.
299 *
300 *	Returns a node pointer with refcount incremented, use
301 *	of_node_put() on it when done.
302 */
303struct device_node *of_get_next_parent(struct device_node *node)
304{
305	struct device_node *parent;
 
306
307	if (!node)
308		return NULL;
309
310	read_lock(&devtree_lock);
311	parent = of_node_get(node->parent);
312	of_node_put(node);
313	read_unlock(&devtree_lock);
314	return parent;
315}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
316
317/**
318 *	of_get_next_child - Iterate a node childs
319 *	@node:	parent node
320 *	@prev:	previous child of the parent node, or NULL to get first
321 *
322 *	Returns a node pointer with refcount incremented, use
323 *	of_node_put() on it when done.
 
324 */
325struct device_node *of_get_next_child(const struct device_node *node,
326	struct device_node *prev)
327{
328	struct device_node *next;
 
329
330	read_lock(&devtree_lock);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
331	next = prev ? prev->sibling : node->child;
332	for (; next; next = next->sibling)
 
 
333		if (of_node_get(next))
334			break;
 
335	of_node_put(prev);
336	read_unlock(&devtree_lock);
337	return next;
338}
339EXPORT_SYMBOL(of_get_next_child);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
340
341/**
342 *	of_find_node_by_path - Find a node matching a full OF path
343 *	@path:	The full path to match
 
344 *
345 *	Returns a node pointer with refcount incremented, use
346 *	of_node_put() on it when done.
 
 
 
347 */
348struct device_node *of_find_node_by_path(const char *path)
 
349{
350	struct device_node *np = allnodes;
351
352	read_lock(&devtree_lock);
353	for (; np; np = np->allnext) {
354		if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
355		    && of_node_get(np))
356			break;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
357	}
358	read_unlock(&devtree_lock);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
359	return np;
360}
361EXPORT_SYMBOL(of_find_node_by_path);
362
363/**
364 *	of_find_node_by_name - Find a node by its "name" property
365 *	@from:	The node to start searching from or NULL, the node
366 *		you pass will not be searched, only the next one
367 *		will; typically, you pass what the previous call
368 *		returned. of_node_put() will be called on it
369 *	@name:	The name string to match against
370 *
371 *	Returns a node pointer with refcount incremented, use
372 *	of_node_put() on it when done.
373 */
374struct device_node *of_find_node_by_name(struct device_node *from,
375	const char *name)
376{
377	struct device_node *np;
 
378
379	read_lock(&devtree_lock);
380	np = from ? from->allnext : allnodes;
381	for (; np; np = np->allnext)
382		if (np->name && (of_node_cmp(np->name, name) == 0)
383		    && of_node_get(np))
384			break;
385	of_node_put(from);
386	read_unlock(&devtree_lock);
387	return np;
388}
389EXPORT_SYMBOL(of_find_node_by_name);
390
391/**
392 *	of_find_node_by_type - Find a node by its "device_type" property
393 *	@from:	The node to start searching from, or NULL to start searching
394 *		the entire device tree. The node you pass will not be
395 *		searched, only the next one will; typically, you pass
396 *		what the previous call returned. of_node_put() will be
397 *		called on from for you.
398 *	@type:	The type string to match against
399 *
400 *	Returns a node pointer with refcount incremented, use
401 *	of_node_put() on it when done.
402 */
403struct device_node *of_find_node_by_type(struct device_node *from,
404	const char *type)
405{
406	struct device_node *np;
 
407
408	read_lock(&devtree_lock);
409	np = from ? from->allnext : allnodes;
410	for (; np; np = np->allnext)
411		if (np->type && (of_node_cmp(np->type, type) == 0)
412		    && of_node_get(np))
413			break;
414	of_node_put(from);
415	read_unlock(&devtree_lock);
416	return np;
417}
418EXPORT_SYMBOL(of_find_node_by_type);
419
420/**
421 *	of_find_compatible_node - Find a node based on type and one of the
422 *                                tokens in its "compatible" property
423 *	@from:		The node to start searching from or NULL, the node
424 *			you pass will not be searched, only the next one
425 *			will; typically, you pass what the previous call
426 *			returned. of_node_put() will be called on it
427 *	@type:		The type string to match "device_type" or NULL to ignore
428 *	@compatible:	The string to match to one of the tokens in the device
429 *			"compatible" list.
430 *
431 *	Returns a node pointer with refcount incremented, use
432 *	of_node_put() on it when done.
433 */
434struct device_node *of_find_compatible_node(struct device_node *from,
435	const char *type, const char *compatible)
436{
437	struct device_node *np;
 
438
439	read_lock(&devtree_lock);
440	np = from ? from->allnext : allnodes;
441	for (; np; np = np->allnext) {
442		if (type
443		    && !(np->type && (of_node_cmp(np->type, type) == 0)))
444			continue;
445		if (of_device_is_compatible(np, compatible) && of_node_get(np))
446			break;
447	}
448	of_node_put(from);
449	read_unlock(&devtree_lock);
450	return np;
451}
452EXPORT_SYMBOL(of_find_compatible_node);
453
454/**
455 *	of_find_node_with_property - Find a node which has a property with
456 *                                   the given name.
457 *	@from:		The node to start searching from or NULL, the node
458 *			you pass will not be searched, only the next one
459 *			will; typically, you pass what the previous call
460 *			returned. of_node_put() will be called on it
461 *	@prop_name:	The name of the property to look for.
462 *
463 *	Returns a node pointer with refcount incremented, use
464 *	of_node_put() on it when done.
465 */
466struct device_node *of_find_node_with_property(struct device_node *from,
467	const char *prop_name)
468{
469	struct device_node *np;
470	struct property *pp;
 
471
472	read_lock(&devtree_lock);
473	np = from ? from->allnext : allnodes;
474	for (; np; np = np->allnext) {
475		for (pp = np->properties; pp != 0; pp = pp->next) {
476			if (of_prop_cmp(pp->name, prop_name) == 0) {
477				of_node_get(np);
478				goto out;
479			}
480		}
481	}
482out:
483	of_node_put(from);
484	read_unlock(&devtree_lock);
485	return np;
486}
487EXPORT_SYMBOL(of_find_node_with_property);
488
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
489/**
490 * of_match_node - Tell if an device_node has a matching of_match structure
491 *	@matches:	array of of device match structures to search in
492 *	@node:		the of device structure to match against
493 *
494 *	Low level utility function used by device matching.
495 */
496const struct of_device_id *of_match_node(const struct of_device_id *matches,
497					 const struct device_node *node)
498{
499	if (!matches)
500		return NULL;
501
502	while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
503		int match = 1;
504		if (matches->name[0])
505			match &= node->name
506				&& !strcmp(matches->name, node->name);
507		if (matches->type[0])
508			match &= node->type
509				&& !strcmp(matches->type, node->type);
510		if (matches->compatible[0])
511			match &= of_device_is_compatible(node,
512						matches->compatible);
513		if (match)
514			return matches;
515		matches++;
516	}
517	return NULL;
518}
519EXPORT_SYMBOL(of_match_node);
520
521/**
522 *	of_find_matching_node - Find a node based on an of_device_id match
523 *				table.
524 *	@from:		The node to start searching from or NULL, the node
525 *			you pass will not be searched, only the next one
526 *			will; typically, you pass what the previous call
527 *			returned. of_node_put() will be called on it
528 *	@matches:	array of of device match structures to search in
529 *
530 *	Returns a node pointer with refcount incremented, use
531 *	of_node_put() on it when done.
532 */
533struct device_node *of_find_matching_node(struct device_node *from,
534					  const struct of_device_id *matches)
 
 
535{
536	struct device_node *np;
 
 
537
538	read_lock(&devtree_lock);
539	np = from ? from->allnext : allnodes;
540	for (; np; np = np->allnext) {
541		if (of_match_node(matches, np) && of_node_get(np))
 
 
 
 
 
542			break;
 
543	}
544	of_node_put(from);
545	read_unlock(&devtree_lock);
546	return np;
547}
548EXPORT_SYMBOL(of_find_matching_node);
549
550/**
551 * of_modalias_node - Lookup appropriate modalias for a device node
552 * @node:	pointer to a device tree node
553 * @modalias:	Pointer to buffer that modalias value will be copied into
554 * @len:	Length of modalias value
555 *
556 * Based on the value of the compatible property, this routine will attempt
557 * to choose an appropriate modalias value for a particular device tree node.
558 * It does this by stripping the manufacturer prefix (as delimited by a ',')
559 * from the first entry in the compatible list property.
560 *
561 * This routine returns 0 on success, <0 on failure.
562 */
563int of_modalias_node(struct device_node *node, char *modalias, int len)
564{
565	const char *compatible, *p;
566	int cplen;
567
568	compatible = of_get_property(node, "compatible", &cplen);
569	if (!compatible || strlen(compatible) > cplen)
570		return -ENODEV;
571	p = strchr(compatible, ',');
572	strlcpy(modalias, p ? p + 1 : compatible, len);
573	return 0;
574}
575EXPORT_SYMBOL_GPL(of_modalias_node);
576
577/**
578 * of_find_node_by_phandle - Find a node given a phandle
579 * @handle:	phandle of the node to find
580 *
581 * Returns a node pointer with refcount incremented, use
582 * of_node_put() on it when done.
583 */
584struct device_node *of_find_node_by_phandle(phandle handle)
585{
586	struct device_node *np;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
587
588	read_lock(&devtree_lock);
589	for (np = allnodes; np; np = np->allnext)
590		if (np->phandle == handle)
591			break;
592	of_node_get(np);
593	read_unlock(&devtree_lock);
594	return np;
595}
596EXPORT_SYMBOL(of_find_node_by_phandle);
597
598/**
599 * of_property_read_u32_array - Find and read an array of 32 bit integers
600 * from a property.
601 *
602 * @np:		device node from which the property value is to be read.
603 * @propname:	name of the property to be searched.
604 * @out_value:	pointer to return value, modified only if return value is 0.
605 *
606 * Search for a property in a device node and read 32-bit value(s) from
607 * it. Returns 0 on success, -EINVAL if the property does not exist,
608 * -ENODATA if property does not have a value, and -EOVERFLOW if the
609 * property data isn't large enough.
610 *
611 * The out_value is modified only if a valid u32 value can be decoded.
612 */
613int of_property_read_u32_array(const struct device_node *np,
614			       const char *propname, u32 *out_values,
615			       size_t sz)
616{
617	struct property *prop = of_find_property(np, propname, NULL);
618	const __be32 *val;
 
 
619
620	if (!prop)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
621		return -EINVAL;
622	if (!prop->value)
623		return -ENODATA;
624	if ((sz * sizeof(*out_values)) > prop->length)
625		return -EOVERFLOW;
626
627	val = prop->value;
628	while (sz--)
629		*out_values++ = be32_to_cpup(val++);
 
 
 
 
630	return 0;
631}
632EXPORT_SYMBOL_GPL(of_property_read_u32_array);
633
634/**
635 * of_property_read_string - Find and read a string from a property
636 * @np:		device node from which the property value is to be read.
637 * @propname:	name of the property to be searched.
638 * @out_string:	pointer to null terminated return string, modified only if
639 *		return value is 0.
640 *
641 * Search for a property in a device tree node and retrieve a null
642 * terminated string value (pointer to data, not a copy). Returns 0 on
643 * success, -EINVAL if the property does not exist, -ENODATA if property
644 * does not have a value, and -EILSEQ if the string is not null-terminated
645 * within the length of the property data.
646 *
647 * The out_string pointer is modified only if a valid string can be decoded.
648 */
649int of_property_read_string(struct device_node *np, const char *propname,
650				const char **out_string)
651{
652	struct property *prop = of_find_property(np, propname, NULL);
653	if (!prop)
654		return -EINVAL;
655	if (!prop->value)
656		return -ENODATA;
657	if (strnlen(prop->value, prop->length) >= prop->length)
658		return -EILSEQ;
659	*out_string = prop->value;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
660	return 0;
 
 
 
 
 
 
 
 
661}
662EXPORT_SYMBOL_GPL(of_property_read_string);
663
664/**
665 * of_parse_phandle - Resolve a phandle property to a device_node pointer
666 * @np: Pointer to device node holding phandle property
667 * @phandle_name: Name of property holding a phandle value
668 * @index: For properties holding a table of phandles, this is the index into
669 *         the table
670 *
671 * Returns the device_node pointer with refcount incremented.  Use
672 * of_node_put() on it when done.
673 */
674struct device_node *
675of_parse_phandle(struct device_node *np, const char *phandle_name, int index)
676{
677	const __be32 *phandle;
678	int size;
679
680	phandle = of_get_property(np, phandle_name, &size);
681	if ((!phandle) || (size < sizeof(*phandle) * (index + 1)))
682		return NULL;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
683
684	return of_find_node_by_phandle(be32_to_cpup(phandle + index));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
685}
686EXPORT_SYMBOL(of_parse_phandle);
687
688/**
689 * of_parse_phandles_with_args - Find a node pointed by phandle in a list
690 * @np:		pointer to a device tree node containing a list
691 * @list_name:	property name that contains a list
692 * @cells_name:	property name that specifies phandles' arguments count
693 * @index:	index of a phandle to parse out
694 * @out_node:	optional pointer to device_node struct pointer (will be filled)
695 * @out_args:	optional pointer to arguments pointer (will be filled)
696 *
697 * This function is useful to parse lists of phandles and their arguments.
698 * Returns 0 on success and fills out_node and out_args, on error returns
699 * appropriate errno value.
700 *
701 * Example:
702 *
703 * phandle1: node1 {
704 * 	#list-cells = <2>;
705 * }
706 *
707 * phandle2: node2 {
708 * 	#list-cells = <1>;
709 * }
710 *
711 * node3 {
712 * 	list = <&phandle1 1 2 &phandle2 3>;
713 * }
714 *
715 * To get a device_node of the `node2' node you may call this:
716 * of_parse_phandles_with_args(node3, "list", "#list-cells", 2, &node2, &args);
717 */
718int of_parse_phandles_with_args(struct device_node *np, const char *list_name,
719				const char *cells_name, int index,
720				struct device_node **out_node,
721				const void **out_args)
722{
723	int ret = -EINVAL;
724	const __be32 *list;
725	const __be32 *list_end;
726	int size;
727	int cur_index = 0;
728	struct device_node *node = NULL;
729	const void *args = NULL;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
730
731	list = of_get_property(np, list_name, &size);
732	if (!list) {
733		ret = -ENOENT;
734		goto err0;
735	}
736	list_end = list + size / sizeof(*list);
737
738	while (list < list_end) {
739		const __be32 *cells;
740		phandle phandle;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
741
742		phandle = be32_to_cpup(list++);
743		args = list;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
744
745		/* one cell hole in the list = <>; */
746		if (!phandle)
747			goto next;
 
748
749		node = of_find_node_by_phandle(phandle);
750		if (!node) {
751			pr_debug("%s: could not find phandle\n",
752				 np->full_name);
753			goto err0;
754		}
 
 
 
 
 
 
 
755
756		cells = of_get_property(node, cells_name, &size);
757		if (!cells || size != sizeof(*cells)) {
758			pr_debug("%s: could not get %s for %s\n",
759				 np->full_name, cells_name, node->full_name);
760			goto err1;
761		}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
762
763		list += be32_to_cpup(cells);
764		if (list > list_end) {
765			pr_debug("%s: insufficient arguments length\n",
766				 np->full_name);
767			goto err1;
768		}
769next:
770		if (cur_index == index)
771			break;
772
773		of_node_put(node);
774		node = NULL;
775		args = NULL;
776		cur_index++;
777	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
778
779	if (!node) {
780		/*
781		 * args w/o node indicates that the loop above has stopped at
782		 * the 'hole' cell. Report this differently.
783		 */
784		if (args)
785			ret = -EEXIST;
786		else
787			ret = -ENOENT;
788		goto err0;
789	}
790
791	if (out_node)
792		*out_node = node;
793	if (out_args)
794		*out_args = args;
795
796	return 0;
797err1:
798	of_node_put(node);
799err0:
800	pr_debug("%s failed with status %d\n", __func__, ret);
801	return ret;
 
802}
803EXPORT_SYMBOL(of_parse_phandles_with_args);
804
805/**
806 * prom_add_property - Add a property to a node
 
 
807 */
808int prom_add_property(struct device_node *np, struct property *prop)
809{
810	struct property **next;
811	unsigned long flags;
812
813	prop->next = NULL;
814	write_lock_irqsave(&devtree_lock, flags);
815	next = &np->properties;
816	while (*next) {
817		if (strcmp(prop->name, (*next)->name) == 0) {
818			/* duplicate ! don't insert it */
819			write_unlock_irqrestore(&devtree_lock, flags);
820			return -1;
821		}
822		next = &(*next)->next;
823	}
824	*next = prop;
825	write_unlock_irqrestore(&devtree_lock, flags);
826
827#ifdef CONFIG_PROC_DEVICETREE
828	/* try to add to proc as well if it was initialized */
829	if (np->pde)
830		proc_device_tree_add_prop(np->pde, prop);
831#endif /* CONFIG_PROC_DEVICETREE */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
832
833	return 0;
834}
835
836/**
837 * prom_remove_property - Remove a property from a node.
 
 
838 *
839 * Note that we don't actually remove it, since we have given out
840 * who-knows-how-many pointers to the data using get-property.
841 * Instead we just move the property to the "dead properties"
842 * list, so it won't be found any more.
843 */
844int prom_remove_property(struct device_node *np, struct property *prop)
845{
846	struct property **next;
847	unsigned long flags;
848	int found = 0;
849
850	write_lock_irqsave(&devtree_lock, flags);
851	next = &np->properties;
852	while (*next) {
853		if (*next == prop) {
854			/* found the node */
855			*next = prop->next;
856			prop->next = np->deadprops;
857			np->deadprops = prop;
858			found = 1;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
859			break;
860		}
861		next = &(*next)->next;
862	}
863	write_unlock_irqrestore(&devtree_lock, flags);
864
865	if (!found)
866		return -ENODEV;
867
868#ifdef CONFIG_PROC_DEVICETREE
869	/* try to remove the proc node as well */
870	if (np->pde)
871		proc_device_tree_remove_prop(np->pde, prop);
872#endif /* CONFIG_PROC_DEVICETREE */
 
 
 
 
 
 
873
874	return 0;
875}
876
877/*
878 * prom_update_property - Update a property in a node.
 
879 *
880 * Note that we don't actually remove it, since we have given out
881 * who-knows-how-many pointers to the data using get-property.
882 * Instead we just move the property to the "dead properties" list,
883 * and add the new property to the property list
884 */
885int prom_update_property(struct device_node *np,
886			 struct property *newprop,
887			 struct property *oldprop)
888{
889	struct property **next;
890	unsigned long flags;
891	int found = 0;
892
893	write_lock_irqsave(&devtree_lock, flags);
894	next = &np->properties;
895	while (*next) {
896		if (*next == oldprop) {
897			/* found the node */
898			newprop->next = oldprop->next;
899			*next = newprop;
900			oldprop->next = np->deadprops;
901			np->deadprops = oldprop;
902			found = 1;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
903			break;
904		}
905		next = &(*next)->next;
906	}
907	write_unlock_irqrestore(&devtree_lock, flags);
908
909	if (!found)
910		return -ENODEV;
 
 
 
 
 
 
 
 
 
 
 
 
 
911
912#ifdef CONFIG_PROC_DEVICETREE
913	/* try to add to proc as well if it was initialized */
914	if (np->pde)
915		proc_device_tree_update_prop(np->pde, newprop, oldprop);
916#endif /* CONFIG_PROC_DEVICETREE */
917
918	return 0;
 
 
 
 
 
919}
 
920
921#if defined(CONFIG_OF_DYNAMIC)
922/*
923 * Support for dynamic device trees.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
924 *
925 * On some platforms, the device tree can be manipulated at runtime.
926 * The routines in this section support adding, removing and changing
927 * device tree nodes.
928 */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
929
930/**
931 * of_attach_node - Plug a device node into the tree and global list.
 
 
 
 
 
 
932 */
933void of_attach_node(struct device_node *np)
934{
935	unsigned long flags;
 
 
 
 
 
 
 
936
937	write_lock_irqsave(&devtree_lock, flags);
938	np->sibling = np->parent->child;
939	np->allnext = allnodes;
940	np->parent->child = np;
941	allnodes = np;
942	write_unlock_irqrestore(&devtree_lock, flags);
943}
944
945/**
946 * of_detach_node - "Unplug" a node from the device tree.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
947 *
948 * The caller must hold a reference to the node.  The memory associated with
949 * the node is not freed until its refcount goes to zero.
950 */
951void of_detach_node(struct device_node *np)
 
 
952{
953	struct device_node *parent;
954	unsigned long flags;
 
955
956	write_lock_irqsave(&devtree_lock, flags);
 
957
958	parent = np->parent;
959	if (!parent)
960		goto out_unlock;
961
962	if (allnodes == np)
963		allnodes = np->allnext;
964	else {
965		struct device_node *prev;
966		for (prev = allnodes;
967		     prev->allnext != np;
968		     prev = prev->allnext)
969			;
970		prev->allnext = np->allnext;
971	}
972
973	if (parent->child == np)
974		parent->child = np->sibling;
975	else {
976		struct device_node *prevsib;
977		for (prevsib = np->parent->child;
978		     prevsib->sibling != np;
979		     prevsib = prevsib->sibling)
980			;
981		prevsib->sibling = np->sibling;
982	}
983
984	of_node_set_flag(np, OF_DETACHED);
 
 
 
 
985
986out_unlock:
987	write_unlock_irqrestore(&devtree_lock, flags);
988}
989#endif /* defined(CONFIG_OF_DYNAMIC) */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
990
v6.2
   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Procedures for creating, accessing and interpreting the device tree.
   4 *
   5 * Paul Mackerras	August 1996.
   6 * Copyright (C) 1996-2005 Paul Mackerras.
   7 *
   8 *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
   9 *    {engebret|bergner}@us.ibm.com
  10 *
  11 *  Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
  12 *
  13 *  Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
  14 *  Grant Likely.
 
 
 
 
 
  15 */
  16
  17#define pr_fmt(fmt)	"OF: " fmt
  18
  19#include <linux/console.h>
  20#include <linux/ctype.h>
  21#include <linux/cpu.h>
  22#include <linux/module.h>
  23#include <linux/of.h>
  24#include <linux/of_device.h>
  25#include <linux/of_graph.h>
  26#include <linux/spinlock.h>
  27#include <linux/slab.h>
  28#include <linux/string.h>
  29#include <linux/proc_fs.h>
  30
  31#include "of_private.h"
  32
  33LIST_HEAD(aliases_lookup);
  34
  35struct device_node *of_root;
  36EXPORT_SYMBOL(of_root);
  37struct device_node *of_chosen;
  38EXPORT_SYMBOL(of_chosen);
  39struct device_node *of_aliases;
  40struct device_node *of_stdout;
  41static const char *of_stdout_options;
  42
  43struct kset *of_kset;
  44
  45/*
  46 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
  47 * This mutex must be held whenever modifications are being made to the
  48 * device tree. The of_{attach,detach}_node() and
  49 * of_{add,remove,update}_property() helpers make sure this happens.
  50 */
  51DEFINE_MUTEX(of_mutex);
  52
  53/* use when traversing tree through the child, sibling,
  54 * or parent members of struct device_node.
  55 */
  56DEFINE_RAW_SPINLOCK(devtree_lock);
  57
  58bool of_node_name_eq(const struct device_node *np, const char *name)
  59{
  60	const char *node_name;
  61	size_t len;
  62
  63	if (!np)
  64		return false;
  65
  66	node_name = kbasename(np->full_name);
  67	len = strchrnul(node_name, '@') - node_name;
  68
  69	return (strlen(name) == len) && (strncmp(node_name, name, len) == 0);
  70}
  71EXPORT_SYMBOL(of_node_name_eq);
  72
  73bool of_node_name_prefix(const struct device_node *np, const char *prefix)
  74{
  75	if (!np)
  76		return false;
  77
  78	return strncmp(kbasename(np->full_name), prefix, strlen(prefix)) == 0;
  79}
  80EXPORT_SYMBOL(of_node_name_prefix);
  81
  82static bool __of_node_is_type(const struct device_node *np, const char *type)
  83{
  84	const char *match = __of_get_property(np, "device_type", NULL);
  85
  86	return np && match && type && !strcmp(match, type);
  87}
  88
  89int of_bus_n_addr_cells(struct device_node *np)
  90{
  91	u32 cells;
  92
  93	for (; np; np = np->parent)
  94		if (!of_property_read_u32(np, "#address-cells", &cells))
  95			return cells;
  96
 
 
 
 
 
 
 
  97	/* No #address-cells property for the root node */
  98	return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
  99}
 100
 101int of_n_addr_cells(struct device_node *np)
 102{
 103	if (np->parent)
 104		np = np->parent;
 105
 106	return of_bus_n_addr_cells(np);
 107}
 108EXPORT_SYMBOL(of_n_addr_cells);
 109
 110int of_bus_n_size_cells(struct device_node *np)
 111{
 112	u32 cells;
 113
 114	for (; np; np = np->parent)
 115		if (!of_property_read_u32(np, "#size-cells", &cells))
 116			return cells;
 117
 
 
 
 
 
 
 
 118	/* No #size-cells property for the root node */
 119	return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
 120}
 121
 122int of_n_size_cells(struct device_node *np)
 123{
 124	if (np->parent)
 125		np = np->parent;
 126
 127	return of_bus_n_size_cells(np);
 128}
 129EXPORT_SYMBOL(of_n_size_cells);
 130
 131#ifdef CONFIG_NUMA
 132int __weak of_node_to_nid(struct device_node *np)
 
 
 
 
 
 
 
 133{
 134	return NUMA_NO_NODE;
 
 
 135}
 136#endif
 137
 138#define OF_PHANDLE_CACHE_BITS	7
 139#define OF_PHANDLE_CACHE_SZ	BIT(OF_PHANDLE_CACHE_BITS)
 140
 141static struct device_node *phandle_cache[OF_PHANDLE_CACHE_SZ];
 142
 143static u32 of_phandle_cache_hash(phandle handle)
 144{
 145	return hash_32(handle, OF_PHANDLE_CACHE_BITS);
 146}
 147
 148/*
 149 * Caller must hold devtree_lock.
 
 
 
 
 150 */
 151void __of_phandle_cache_inv_entry(phandle handle)
 152{
 153	u32 handle_hash;
 154	struct device_node *np;
 
 
 
 
 
 
 
 
 155
 156	if (!handle)
 157		return;
 158
 159	handle_hash = of_phandle_cache_hash(handle);
 
 
 
 
 
 160
 161	np = phandle_cache[handle_hash];
 162	if (np && handle == np->phandle)
 163		phandle_cache[handle_hash] = NULL;
 
 
 
 
 
 164}
 165
 166void __init of_core_init(void)
 
 
 
 
 
 
 167{
 168	struct device_node *np;
 169
 170
 171	/* Create the kset, and register existing nodes */
 172	mutex_lock(&of_mutex);
 173	of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
 174	if (!of_kset) {
 175		mutex_unlock(&of_mutex);
 176		pr_err("failed to register existing nodes\n");
 177		return;
 178	}
 179	for_each_of_allnodes(np) {
 180		__of_attach_node_sysfs(np);
 181		if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)])
 182			phandle_cache[of_phandle_cache_hash(np->phandle)] = np;
 183	}
 184	mutex_unlock(&of_mutex);
 185
 186	/* Symlink in /proc as required by userspace ABI */
 187	if (of_root)
 188		proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
 189}
 
 
 190
 191static struct property *__of_find_property(const struct device_node *np,
 192					   const char *name, int *lenp)
 
 193{
 194	struct property *pp;
 195
 196	if (!np)
 197		return NULL;
 198
 199	for (pp = np->properties; pp; pp = pp->next) {
 
 200		if (of_prop_cmp(pp->name, name) == 0) {
 201			if (lenp)
 202				*lenp = pp->length;
 203			break;
 204		}
 205	}
 206
 207	return pp;
 208}
 209
 210struct property *of_find_property(const struct device_node *np,
 211				  const char *name,
 212				  int *lenp)
 213{
 214	struct property *pp;
 215	unsigned long flags;
 216
 217	raw_spin_lock_irqsave(&devtree_lock, flags);
 218	pp = __of_find_property(np, name, lenp);
 219	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 220
 221	return pp;
 222}
 223EXPORT_SYMBOL(of_find_property);
 224
 225struct device_node *__of_find_all_nodes(struct device_node *prev)
 226{
 227	struct device_node *np;
 228	if (!prev) {
 229		np = of_root;
 230	} else if (prev->child) {
 231		np = prev->child;
 232	} else {
 233		/* Walk back up looking for a sibling, or the end of the structure */
 234		np = prev;
 235		while (np->parent && !np->sibling)
 236			np = np->parent;
 237		np = np->sibling; /* Might be null at the end of the tree */
 238	}
 239	return np;
 240}
 241
 242/**
 243 * of_find_all_nodes - Get next node in global list
 244 * @prev:	Previous node or NULL to start iteration
 245 *		of_node_put() will be called on it
 246 *
 247 * Return: A node pointer with refcount incremented, use
 248 * of_node_put() on it when done.
 249 */
 250struct device_node *of_find_all_nodes(struct device_node *prev)
 251{
 252	struct device_node *np;
 253	unsigned long flags;
 254
 255	raw_spin_lock_irqsave(&devtree_lock, flags);
 256	np = __of_find_all_nodes(prev);
 257	of_node_get(np);
 
 
 258	of_node_put(prev);
 259	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 260	return np;
 261}
 262EXPORT_SYMBOL(of_find_all_nodes);
 263
 264/*
 265 * Find a property with a given name for a given node
 266 * and return the value.
 267 */
 268const void *__of_get_property(const struct device_node *np,
 269			      const char *name, int *lenp)
 270{
 271	struct property *pp = __of_find_property(np, name, lenp);
 272
 273	return pp ? pp->value : NULL;
 274}
 275
 276/*
 277 * Find a property with a given name for a given node
 278 * and return the value.
 279 */
 280const void *of_get_property(const struct device_node *np, const char *name,
 281			    int *lenp)
 282{
 283	struct property *pp = of_find_property(np, name, lenp);
 284
 285	return pp ? pp->value : NULL;
 286}
 287EXPORT_SYMBOL(of_get_property);
 288
 289/**
 290 * of_get_cpu_hwid - Get the hardware ID from a CPU device node
 291 *
 292 * @cpun: CPU number(logical index) for which device node is required
 293 * @thread: The local thread number to get the hardware ID for.
 294 *
 295 * Return: The hardware ID for the CPU node or ~0ULL if not found.
 296 */
 297u64 of_get_cpu_hwid(struct device_node *cpun, unsigned int thread)
 298{
 299	const __be32 *cell;
 300	int ac, len;
 301
 302	ac = of_n_addr_cells(cpun);
 303	cell = of_get_property(cpun, "reg", &len);
 304	if (!cell || !ac || ((sizeof(*cell) * ac * (thread + 1)) > len))
 305		return ~0ULL;
 306
 307	cell += ac * thread;
 308	return of_read_number(cell, ac);
 309}
 310
 311/*
 312 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
 313 *
 314 * @cpu: logical cpu index of a core/thread
 315 * @phys_id: physical identifier of a core/thread
 316 *
 317 * CPU logical to physical index mapping is architecture specific.
 318 * However this __weak function provides a default match of physical
 319 * id to logical cpu index. phys_id provided here is usually values read
 320 * from the device tree which must match the hardware internal registers.
 321 *
 322 * Returns true if the physical identifier and the logical cpu index
 323 * correspond to the same core/thread, false otherwise.
 324 */
 325bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
 326{
 327	return (u32)phys_id == cpu;
 328}
 329
 330/*
 331 * Checks if the given "prop_name" property holds the physical id of the
 332 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
 333 * NULL, local thread number within the core is returned in it.
 334 */
 335static bool __of_find_n_match_cpu_property(struct device_node *cpun,
 336			const char *prop_name, int cpu, unsigned int *thread)
 337{
 338	const __be32 *cell;
 339	int ac, prop_len, tid;
 340	u64 hwid;
 341
 342	ac = of_n_addr_cells(cpun);
 343	cell = of_get_property(cpun, prop_name, &prop_len);
 344	if (!cell && !ac && arch_match_cpu_phys_id(cpu, 0))
 345		return true;
 346	if (!cell || !ac)
 347		return false;
 348	prop_len /= sizeof(*cell) * ac;
 349	for (tid = 0; tid < prop_len; tid++) {
 350		hwid = of_read_number(cell, ac);
 351		if (arch_match_cpu_phys_id(cpu, hwid)) {
 352			if (thread)
 353				*thread = tid;
 354			return true;
 355		}
 356		cell += ac;
 357	}
 358	return false;
 359}
 360
 361/*
 362 * arch_find_n_match_cpu_physical_id - See if the given device node is
 363 * for the cpu corresponding to logical cpu 'cpu'.  Return true if so,
 364 * else false.  If 'thread' is non-NULL, the local thread number within the
 365 * core is returned in it.
 366 */
 367bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
 368					      int cpu, unsigned int *thread)
 369{
 370	/* Check for non-standard "ibm,ppc-interrupt-server#s" property
 371	 * for thread ids on PowerPC. If it doesn't exist fallback to
 372	 * standard "reg" property.
 373	 */
 374	if (IS_ENABLED(CONFIG_PPC) &&
 375	    __of_find_n_match_cpu_property(cpun,
 376					   "ibm,ppc-interrupt-server#s",
 377					   cpu, thread))
 378		return true;
 379
 380	return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
 381}
 382
 383/**
 384 * of_get_cpu_node - Get device node associated with the given logical CPU
 385 *
 386 * @cpu: CPU number(logical index) for which device node is required
 387 * @thread: if not NULL, local thread number within the physical core is
 388 *          returned
 389 *
 390 * The main purpose of this function is to retrieve the device node for the
 391 * given logical CPU index. It should be used to initialize the of_node in
 392 * cpu device. Once of_node in cpu device is populated, all the further
 393 * references can use that instead.
 394 *
 395 * CPU logical to physical index mapping is architecture specific and is built
 396 * before booting secondary cores. This function uses arch_match_cpu_phys_id
 397 * which can be overridden by architecture specific implementation.
 398 *
 399 * Return: A node pointer for the logical cpu with refcount incremented, use
 400 * of_node_put() on it when done. Returns NULL if not found.
 401 */
 402struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
 403{
 404	struct device_node *cpun;
 405
 406	for_each_of_cpu_node(cpun) {
 407		if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
 408			return cpun;
 409	}
 410	return NULL;
 411}
 412EXPORT_SYMBOL(of_get_cpu_node);
 413
 414/**
 415 * of_cpu_node_to_id: Get the logical CPU number for a given device_node
 416 *
 417 * @cpu_node: Pointer to the device_node for CPU.
 418 *
 419 * Return: The logical CPU number of the given CPU device_node or -ENODEV if the
 420 * CPU is not found.
 421 */
 422int of_cpu_node_to_id(struct device_node *cpu_node)
 423{
 424	int cpu;
 425	bool found = false;
 426	struct device_node *np;
 427
 428	for_each_possible_cpu(cpu) {
 429		np = of_cpu_device_node_get(cpu);
 430		found = (cpu_node == np);
 431		of_node_put(np);
 432		if (found)
 433			return cpu;
 434	}
 435
 436	return -ENODEV;
 437}
 438EXPORT_SYMBOL(of_cpu_node_to_id);
 439
 440/**
 441 * of_get_cpu_state_node - Get CPU's idle state node at the given index
 442 *
 443 * @cpu_node: The device node for the CPU
 444 * @index: The index in the list of the idle states
 445 *
 446 * Two generic methods can be used to describe a CPU's idle states, either via
 447 * a flattened description through the "cpu-idle-states" binding or via the
 448 * hierarchical layout, using the "power-domains" and the "domain-idle-states"
 449 * bindings. This function check for both and returns the idle state node for
 450 * the requested index.
 451 *
 452 * Return: An idle state node if found at @index. The refcount is incremented
 453 * for it, so call of_node_put() on it when done. Returns NULL if not found.
 454 */
 455struct device_node *of_get_cpu_state_node(struct device_node *cpu_node,
 456					  int index)
 457{
 458	struct of_phandle_args args;
 459	int err;
 460
 461	err = of_parse_phandle_with_args(cpu_node, "power-domains",
 462					"#power-domain-cells", 0, &args);
 463	if (!err) {
 464		struct device_node *state_node =
 465			of_parse_phandle(args.np, "domain-idle-states", index);
 466
 467		of_node_put(args.np);
 468		if (state_node)
 469			return state_node;
 470	}
 471
 472	return of_parse_phandle(cpu_node, "cpu-idle-states", index);
 473}
 474EXPORT_SYMBOL(of_get_cpu_state_node);
 475
 476/**
 477 * __of_device_is_compatible() - Check if the node matches given constraints
 478 * @device: pointer to node
 479 * @compat: required compatible string, NULL or "" for any match
 480 * @type: required device_type value, NULL or "" for any match
 481 * @name: required node name, NULL or "" for any match
 482 *
 483 * Checks if the given @compat, @type and @name strings match the
 484 * properties of the given @device. A constraints can be skipped by
 485 * passing NULL or an empty string as the constraint.
 486 *
 487 * Returns 0 for no match, and a positive integer on match. The return
 488 * value is a relative score with larger values indicating better
 489 * matches. The score is weighted for the most specific compatible value
 490 * to get the highest score. Matching type is next, followed by matching
 491 * name. Practically speaking, this results in the following priority
 492 * order for matches:
 493 *
 494 * 1. specific compatible && type && name
 495 * 2. specific compatible && type
 496 * 3. specific compatible && name
 497 * 4. specific compatible
 498 * 5. general compatible && type && name
 499 * 6. general compatible && type
 500 * 7. general compatible && name
 501 * 8. general compatible
 502 * 9. type && name
 503 * 10. type
 504 * 11. name
 505 */
 506static int __of_device_is_compatible(const struct device_node *device,
 507				     const char *compat, const char *type, const char *name)
 508{
 509	struct property *prop;
 510	const char *cp;
 511	int index = 0, score = 0;
 512
 513	/* Compatible match has highest priority */
 514	if (compat && compat[0]) {
 515		prop = __of_find_property(device, "compatible", NULL);
 516		for (cp = of_prop_next_string(prop, NULL); cp;
 517		     cp = of_prop_next_string(prop, cp), index++) {
 518			if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
 519				score = INT_MAX/2 - (index << 2);
 520				break;
 521			}
 522		}
 523		if (!score)
 524			return 0;
 525	}
 526
 527	/* Matching type is better than matching name */
 528	if (type && type[0]) {
 529		if (!__of_node_is_type(device, type))
 530			return 0;
 531		score += 2;
 532	}
 533
 534	/* Matching name is a bit better than not */
 535	if (name && name[0]) {
 536		if (!of_node_name_eq(device, name))
 537			return 0;
 538		score++;
 539	}
 540
 541	return score;
 542}
 543
 544/** Checks if the given "compat" string matches one of the strings in
 545 * the device's "compatible" property
 546 */
 547int of_device_is_compatible(const struct device_node *device,
 548		const char *compat)
 549{
 550	unsigned long flags;
 551	int res;
 552
 553	raw_spin_lock_irqsave(&devtree_lock, flags);
 554	res = __of_device_is_compatible(device, compat, NULL, NULL);
 555	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 556	return res;
 557}
 558EXPORT_SYMBOL(of_device_is_compatible);
 559
 560/** Checks if the device is compatible with any of the entries in
 561 *  a NULL terminated array of strings. Returns the best match
 562 *  score or 0.
 563 */
 564int of_device_compatible_match(const struct device_node *device,
 565			       const char *const *compat)
 566{
 567	unsigned int tmp, score = 0;
 568
 569	if (!compat)
 
 570		return 0;
 571
 572	while (*compat) {
 573		tmp = of_device_is_compatible(device, *compat);
 574		if (tmp > score)
 575			score = tmp;
 576		compat++;
 577	}
 578
 579	return score;
 580}
 581EXPORT_SYMBOL_GPL(of_device_compatible_match);
 582
 583/**
 584 * of_machine_is_compatible - Test root of device tree for a given compatible value
 585 * @compat: compatible string to look for in root node's compatible property.
 586 *
 587 * Return: A positive integer if the root node has the given value in its
 588 * compatible property.
 589 */
 590int of_machine_is_compatible(const char *compat)
 591{
 592	struct device_node *root;
 593	int rc = 0;
 594
 595	root = of_find_node_by_path("/");
 596	if (root) {
 597		rc = of_device_is_compatible(root, compat);
 598		of_node_put(root);
 599	}
 600	return rc;
 601}
 602EXPORT_SYMBOL(of_machine_is_compatible);
 603
 604/**
 605 *  __of_device_is_available - check if a device is available for use
 606 *
 607 *  @device: Node to check for availability, with locks already held
 608 *
 609 *  Return: True if the status property is absent or set to "okay" or "ok",
 610 *  false otherwise
 611 */
 612static bool __of_device_is_available(const struct device_node *device)
 613{
 614	const char *status;
 615	int statlen;
 616
 617	if (!device)
 618		return false;
 619
 620	status = __of_get_property(device, "status", &statlen);
 621	if (status == NULL)
 622		return true;
 623
 624	if (statlen > 0) {
 625		if (!strcmp(status, "okay") || !strcmp(status, "ok"))
 626			return true;
 627	}
 628
 629	return false;
 630}
 631
 632/**
 633 *  of_device_is_available - check if a device is available for use
 634 *
 635 *  @device: Node to check for availability
 636 *
 637 *  Return: True if the status property is absent or set to "okay" or "ok",
 638 *  false otherwise
 639 */
 640bool of_device_is_available(const struct device_node *device)
 641{
 642	unsigned long flags;
 643	bool res;
 644
 645	raw_spin_lock_irqsave(&devtree_lock, flags);
 646	res = __of_device_is_available(device);
 647	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 648	return res;
 649
 650}
 651EXPORT_SYMBOL(of_device_is_available);
 652
 653/**
 654 *  __of_device_is_fail - check if a device has status "fail" or "fail-..."
 655 *
 656 *  @device: Node to check status for, with locks already held
 657 *
 658 *  Return: True if the status property is set to "fail" or "fail-..." (for any
 659 *  error code suffix), false otherwise
 660 */
 661static bool __of_device_is_fail(const struct device_node *device)
 662{
 663	const char *status;
 664
 665	if (!device)
 666		return false;
 667
 668	status = __of_get_property(device, "status", NULL);
 669	if (status == NULL)
 670		return false;
 671
 672	return !strcmp(status, "fail") || !strncmp(status, "fail-", 5);
 673}
 674
 675/**
 676 *  of_device_is_big_endian - check if a device has BE registers
 677 *
 678 *  @device: Node to check for endianness
 679 *
 680 *  Return: True if the device has a "big-endian" property, or if the kernel
 681 *  was compiled for BE *and* the device has a "native-endian" property.
 682 *  Returns false otherwise.
 683 *
 684 *  Callers would nominally use ioread32be/iowrite32be if
 685 *  of_device_is_big_endian() == true, or readl/writel otherwise.
 686 */
 687bool of_device_is_big_endian(const struct device_node *device)
 688{
 689	if (of_property_read_bool(device, "big-endian"))
 690		return true;
 691	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
 692	    of_property_read_bool(device, "native-endian"))
 693		return true;
 694	return false;
 695}
 696EXPORT_SYMBOL(of_device_is_big_endian);
 697
 698/**
 699 * of_get_parent - Get a node's parent if any
 700 * @node:	Node to get parent
 701 *
 702 * Return: A node pointer with refcount incremented, use
 703 * of_node_put() on it when done.
 704 */
 705struct device_node *of_get_parent(const struct device_node *node)
 706{
 707	struct device_node *np;
 708	unsigned long flags;
 709
 710	if (!node)
 711		return NULL;
 712
 713	raw_spin_lock_irqsave(&devtree_lock, flags);
 714	np = of_node_get(node->parent);
 715	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 716	return np;
 717}
 718EXPORT_SYMBOL(of_get_parent);
 719
 720/**
 721 * of_get_next_parent - Iterate to a node's parent
 722 * @node:	Node to get parent of
 723 *
 724 * This is like of_get_parent() except that it drops the
 725 * refcount on the passed node, making it suitable for iterating
 726 * through a node's parents.
 727 *
 728 * Return: A node pointer with refcount incremented, use
 729 * of_node_put() on it when done.
 730 */
 731struct device_node *of_get_next_parent(struct device_node *node)
 732{
 733	struct device_node *parent;
 734	unsigned long flags;
 735
 736	if (!node)
 737		return NULL;
 738
 739	raw_spin_lock_irqsave(&devtree_lock, flags);
 740	parent = of_node_get(node->parent);
 741	of_node_put(node);
 742	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 743	return parent;
 744}
 745EXPORT_SYMBOL(of_get_next_parent);
 746
 747static struct device_node *__of_get_next_child(const struct device_node *node,
 748						struct device_node *prev)
 749{
 750	struct device_node *next;
 751
 752	if (!node)
 753		return NULL;
 754
 755	next = prev ? prev->sibling : node->child;
 756	of_node_get(next);
 757	of_node_put(prev);
 758	return next;
 759}
 760#define __for_each_child_of_node(parent, child) \
 761	for (child = __of_get_next_child(parent, NULL); child != NULL; \
 762	     child = __of_get_next_child(parent, child))
 763
 764/**
 765 * of_get_next_child - Iterate a node childs
 766 * @node:	parent node
 767 * @prev:	previous child of the parent node, or NULL to get first
 768 *
 769 * Return: A node pointer with refcount incremented, use of_node_put() on
 770 * it when done. Returns NULL when prev is the last child. Decrements the
 771 * refcount of prev.
 772 */
 773struct device_node *of_get_next_child(const struct device_node *node,
 774	struct device_node *prev)
 775{
 776	struct device_node *next;
 777	unsigned long flags;
 778
 779	raw_spin_lock_irqsave(&devtree_lock, flags);
 780	next = __of_get_next_child(node, prev);
 781	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 782	return next;
 783}
 784EXPORT_SYMBOL(of_get_next_child);
 785
 786/**
 787 * of_get_next_available_child - Find the next available child node
 788 * @node:	parent node
 789 * @prev:	previous child of the parent node, or NULL to get first
 790 *
 791 * This function is like of_get_next_child(), except that it
 792 * automatically skips any disabled nodes (i.e. status = "disabled").
 793 */
 794struct device_node *of_get_next_available_child(const struct device_node *node,
 795	struct device_node *prev)
 796{
 797	struct device_node *next;
 798	unsigned long flags;
 799
 800	if (!node)
 801		return NULL;
 802
 803	raw_spin_lock_irqsave(&devtree_lock, flags);
 804	next = prev ? prev->sibling : node->child;
 805	for (; next; next = next->sibling) {
 806		if (!__of_device_is_available(next))
 807			continue;
 808		if (of_node_get(next))
 809			break;
 810	}
 811	of_node_put(prev);
 812	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 813	return next;
 814}
 815EXPORT_SYMBOL(of_get_next_available_child);
 816
 817/**
 818 * of_get_next_cpu_node - Iterate on cpu nodes
 819 * @prev:	previous child of the /cpus node, or NULL to get first
 820 *
 821 * Unusable CPUs (those with the status property set to "fail" or "fail-...")
 822 * will be skipped.
 823 *
 824 * Return: A cpu node pointer with refcount incremented, use of_node_put()
 825 * on it when done. Returns NULL when prev is the last child. Decrements
 826 * the refcount of prev.
 827 */
 828struct device_node *of_get_next_cpu_node(struct device_node *prev)
 829{
 830	struct device_node *next = NULL;
 831	unsigned long flags;
 832	struct device_node *node;
 833
 834	if (!prev)
 835		node = of_find_node_by_path("/cpus");
 836
 837	raw_spin_lock_irqsave(&devtree_lock, flags);
 838	if (prev)
 839		next = prev->sibling;
 840	else if (node) {
 841		next = node->child;
 842		of_node_put(node);
 843	}
 844	for (; next; next = next->sibling) {
 845		if (__of_device_is_fail(next))
 846			continue;
 847		if (!(of_node_name_eq(next, "cpu") ||
 848		      __of_node_is_type(next, "cpu")))
 849			continue;
 850		if (of_node_get(next))
 851			break;
 852	}
 853	of_node_put(prev);
 854	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 855	return next;
 856}
 857EXPORT_SYMBOL(of_get_next_cpu_node);
 858
 859/**
 860 * of_get_compatible_child - Find compatible child node
 861 * @parent:	parent node
 862 * @compatible:	compatible string
 863 *
 864 * Lookup child node whose compatible property contains the given compatible
 865 * string.
 866 *
 867 * Return: a node pointer with refcount incremented, use of_node_put() on it
 868 * when done; or NULL if not found.
 869 */
 870struct device_node *of_get_compatible_child(const struct device_node *parent,
 871				const char *compatible)
 872{
 873	struct device_node *child;
 874
 875	for_each_child_of_node(parent, child) {
 876		if (of_device_is_compatible(child, compatible))
 877			break;
 878	}
 879
 880	return child;
 881}
 882EXPORT_SYMBOL(of_get_compatible_child);
 883
 884/**
 885 * of_get_child_by_name - Find the child node by name for a given parent
 886 * @node:	parent node
 887 * @name:	child name to look for.
 888 *
 889 * This function looks for child node for given matching name
 890 *
 891 * Return: A node pointer if found, with refcount incremented, use
 892 * of_node_put() on it when done.
 893 * Returns NULL if node is not found.
 894 */
 895struct device_node *of_get_child_by_name(const struct device_node *node,
 896				const char *name)
 897{
 898	struct device_node *child;
 899
 900	for_each_child_of_node(node, child)
 901		if (of_node_name_eq(child, name))
 
 
 902			break;
 903	return child;
 904}
 905EXPORT_SYMBOL(of_get_child_by_name);
 906
 907struct device_node *__of_find_node_by_path(struct device_node *parent,
 908						const char *path)
 909{
 910	struct device_node *child;
 911	int len;
 912
 913	len = strcspn(path, "/:");
 914	if (!len)
 915		return NULL;
 916
 917	__for_each_child_of_node(parent, child) {
 918		const char *name = kbasename(child->full_name);
 919		if (strncmp(path, name, len) == 0 && (strlen(name) == len))
 920			return child;
 921	}
 922	return NULL;
 923}
 924
 925struct device_node *__of_find_node_by_full_path(struct device_node *node,
 926						const char *path)
 927{
 928	const char *separator = strchr(path, ':');
 929
 930	while (node && *path == '/') {
 931		struct device_node *tmp = node;
 932
 933		path++; /* Increment past '/' delimiter */
 934		node = __of_find_node_by_path(node, path);
 935		of_node_put(tmp);
 936		path = strchrnul(path, '/');
 937		if (separator && separator < path)
 938			break;
 939	}
 940	return node;
 941}
 942
 943/**
 944 * of_find_node_opts_by_path - Find a node matching a full OF path
 945 * @path: Either the full path to match, or if the path does not
 946 *       start with '/', the name of a property of the /aliases
 947 *       node (an alias).  In the case of an alias, the node
 948 *       matching the alias' value will be returned.
 949 * @opts: Address of a pointer into which to store the start of
 950 *       an options string appended to the end of the path with
 951 *       a ':' separator.
 952 *
 953 * Valid paths:
 954 *  * /foo/bar	Full path
 955 *  * foo	Valid alias
 956 *  * foo/bar	Valid alias + relative path
 957 *
 958 * Return: A node pointer with refcount incremented, use
 959 * of_node_put() on it when done.
 960 */
 961struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
 962{
 963	struct device_node *np = NULL;
 964	struct property *pp;
 965	unsigned long flags;
 966	const char *separator = strchr(path, ':');
 967
 968	if (opts)
 969		*opts = separator ? separator + 1 : NULL;
 970
 971	if (strcmp(path, "/") == 0)
 972		return of_node_get(of_root);
 973
 974	/* The path could begin with an alias */
 975	if (*path != '/') {
 976		int len;
 977		const char *p = separator;
 978
 979		if (!p)
 980			p = strchrnul(path, '/');
 981		len = p - path;
 982
 983		/* of_aliases must not be NULL */
 984		if (!of_aliases)
 985			return NULL;
 986
 987		for_each_property_of_node(of_aliases, pp) {
 988			if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
 989				np = of_find_node_by_path(pp->value);
 990				break;
 991			}
 992		}
 993		if (!np)
 994			return NULL;
 995		path = p;
 996	}
 997
 998	/* Step down the tree matching path components */
 999	raw_spin_lock_irqsave(&devtree_lock, flags);
1000	if (!np)
1001		np = of_node_get(of_root);
1002	np = __of_find_node_by_full_path(np, path);
1003	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1004	return np;
1005}
1006EXPORT_SYMBOL(of_find_node_opts_by_path);
1007
1008/**
1009 * of_find_node_by_name - Find a node by its "name" property
1010 * @from:	The node to start searching from or NULL; the node
1011 *		you pass will not be searched, only the next one
1012 *		will. Typically, you pass what the previous call
1013 *		returned. of_node_put() will be called on @from.
1014 * @name:	The name string to match against
1015 *
1016 * Return: A node pointer with refcount incremented, use
1017 * of_node_put() on it when done.
1018 */
1019struct device_node *of_find_node_by_name(struct device_node *from,
1020	const char *name)
1021{
1022	struct device_node *np;
1023	unsigned long flags;
1024
1025	raw_spin_lock_irqsave(&devtree_lock, flags);
1026	for_each_of_allnodes_from(from, np)
1027		if (of_node_name_eq(np, name) && of_node_get(np))
 
 
1028			break;
1029	of_node_put(from);
1030	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1031	return np;
1032}
1033EXPORT_SYMBOL(of_find_node_by_name);
1034
1035/**
1036 * of_find_node_by_type - Find a node by its "device_type" property
1037 * @from:	The node to start searching from, or NULL to start searching
1038 *		the entire device tree. The node you pass will not be
1039 *		searched, only the next one will; typically, you pass
1040 *		what the previous call returned. of_node_put() will be
1041 *		called on from for you.
1042 * @type:	The type string to match against
1043 *
1044 * Return: A node pointer with refcount incremented, use
1045 * of_node_put() on it when done.
1046 */
1047struct device_node *of_find_node_by_type(struct device_node *from,
1048	const char *type)
1049{
1050	struct device_node *np;
1051	unsigned long flags;
1052
1053	raw_spin_lock_irqsave(&devtree_lock, flags);
1054	for_each_of_allnodes_from(from, np)
1055		if (__of_node_is_type(np, type) && of_node_get(np))
 
 
1056			break;
1057	of_node_put(from);
1058	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1059	return np;
1060}
1061EXPORT_SYMBOL(of_find_node_by_type);
1062
1063/**
1064 * of_find_compatible_node - Find a node based on type and one of the
1065 *                                tokens in its "compatible" property
1066 * @from:	The node to start searching from or NULL, the node
1067 *		you pass will not be searched, only the next one
1068 *		will; typically, you pass what the previous call
1069 *		returned. of_node_put() will be called on it
1070 * @type:	The type string to match "device_type" or NULL to ignore
1071 * @compatible:	The string to match to one of the tokens in the device
1072 *		"compatible" list.
1073 *
1074 * Return: A node pointer with refcount incremented, use
1075 * of_node_put() on it when done.
1076 */
1077struct device_node *of_find_compatible_node(struct device_node *from,
1078	const char *type, const char *compatible)
1079{
1080	struct device_node *np;
1081	unsigned long flags;
1082
1083	raw_spin_lock_irqsave(&devtree_lock, flags);
1084	for_each_of_allnodes_from(from, np)
1085		if (__of_device_is_compatible(np, compatible, type, NULL) &&
1086		    of_node_get(np))
 
 
 
1087			break;
 
1088	of_node_put(from);
1089	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1090	return np;
1091}
1092EXPORT_SYMBOL(of_find_compatible_node);
1093
1094/**
1095 * of_find_node_with_property - Find a node which has a property with
1096 *                              the given name.
1097 * @from:	The node to start searching from or NULL, the node
1098 *		you pass will not be searched, only the next one
1099 *		will; typically, you pass what the previous call
1100 *		returned. of_node_put() will be called on it
1101 * @prop_name:	The name of the property to look for.
1102 *
1103 * Return: A node pointer with refcount incremented, use
1104 * of_node_put() on it when done.
1105 */
1106struct device_node *of_find_node_with_property(struct device_node *from,
1107	const char *prop_name)
1108{
1109	struct device_node *np;
1110	struct property *pp;
1111	unsigned long flags;
1112
1113	raw_spin_lock_irqsave(&devtree_lock, flags);
1114	for_each_of_allnodes_from(from, np) {
1115		for (pp = np->properties; pp; pp = pp->next) {
 
1116			if (of_prop_cmp(pp->name, prop_name) == 0) {
1117				of_node_get(np);
1118				goto out;
1119			}
1120		}
1121	}
1122out:
1123	of_node_put(from);
1124	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1125	return np;
1126}
1127EXPORT_SYMBOL(of_find_node_with_property);
1128
1129static
1130const struct of_device_id *__of_match_node(const struct of_device_id *matches,
1131					   const struct device_node *node)
1132{
1133	const struct of_device_id *best_match = NULL;
1134	int score, best_score = 0;
1135
1136	if (!matches)
1137		return NULL;
1138
1139	for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
1140		score = __of_device_is_compatible(node, matches->compatible,
1141						  matches->type, matches->name);
1142		if (score > best_score) {
1143			best_match = matches;
1144			best_score = score;
1145		}
1146	}
1147
1148	return best_match;
1149}
1150
1151/**
1152 * of_match_node - Tell if a device_node has a matching of_match structure
1153 * @matches:	array of of device match structures to search in
1154 * @node:	the of device structure to match against
1155 *
1156 * Low level utility function used by device matching.
1157 */
1158const struct of_device_id *of_match_node(const struct of_device_id *matches,
1159					 const struct device_node *node)
1160{
1161	const struct of_device_id *match;
1162	unsigned long flags;
1163
1164	raw_spin_lock_irqsave(&devtree_lock, flags);
1165	match = __of_match_node(matches, node);
1166	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1167	return match;
 
 
 
 
 
 
 
 
 
 
 
 
1168}
1169EXPORT_SYMBOL(of_match_node);
1170
1171/**
1172 * of_find_matching_node_and_match - Find a node based on an of_device_id
1173 *				     match table.
1174 * @from:	The node to start searching from or NULL, the node
1175 *		you pass will not be searched, only the next one
1176 *		will; typically, you pass what the previous call
1177 *		returned. of_node_put() will be called on it
1178 * @matches:	array of of device match structures to search in
1179 * @match:	Updated to point at the matches entry which matched
1180 *
1181 * Return: A node pointer with refcount incremented, use
1182 * of_node_put() on it when done.
1183 */
1184struct device_node *of_find_matching_node_and_match(struct device_node *from,
1185					const struct of_device_id *matches,
1186					const struct of_device_id **match)
1187{
1188	struct device_node *np;
1189	const struct of_device_id *m;
1190	unsigned long flags;
1191
1192	if (match)
1193		*match = NULL;
1194
1195	raw_spin_lock_irqsave(&devtree_lock, flags);
1196	for_each_of_allnodes_from(from, np) {
1197		m = __of_match_node(matches, np);
1198		if (m && of_node_get(np)) {
1199			if (match)
1200				*match = m;
1201			break;
1202		}
1203	}
1204	of_node_put(from);
1205	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1206	return np;
1207}
1208EXPORT_SYMBOL(of_find_matching_node_and_match);
1209
1210/**
1211 * of_modalias_node - Lookup appropriate modalias for a device node
1212 * @node:	pointer to a device tree node
1213 * @modalias:	Pointer to buffer that modalias value will be copied into
1214 * @len:	Length of modalias value
1215 *
1216 * Based on the value of the compatible property, this routine will attempt
1217 * to choose an appropriate modalias value for a particular device tree node.
1218 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1219 * from the first entry in the compatible list property.
1220 *
1221 * Return: This routine returns 0 on success, <0 on failure.
1222 */
1223int of_modalias_node(struct device_node *node, char *modalias, int len)
1224{
1225	const char *compatible, *p;
1226	int cplen;
1227
1228	compatible = of_get_property(node, "compatible", &cplen);
1229	if (!compatible || strlen(compatible) > cplen)
1230		return -ENODEV;
1231	p = strchr(compatible, ',');
1232	strscpy(modalias, p ? p + 1 : compatible, len);
1233	return 0;
1234}
1235EXPORT_SYMBOL_GPL(of_modalias_node);
1236
1237/**
1238 * of_find_node_by_phandle - Find a node given a phandle
1239 * @handle:	phandle of the node to find
1240 *
1241 * Return: A node pointer with refcount incremented, use
1242 * of_node_put() on it when done.
1243 */
1244struct device_node *of_find_node_by_phandle(phandle handle)
1245{
1246	struct device_node *np = NULL;
1247	unsigned long flags;
1248	u32 handle_hash;
1249
1250	if (!handle)
1251		return NULL;
1252
1253	handle_hash = of_phandle_cache_hash(handle);
1254
1255	raw_spin_lock_irqsave(&devtree_lock, flags);
1256
1257	if (phandle_cache[handle_hash] &&
1258	    handle == phandle_cache[handle_hash]->phandle)
1259		np = phandle_cache[handle_hash];
1260
1261	if (!np) {
1262		for_each_of_allnodes(np)
1263			if (np->phandle == handle &&
1264			    !of_node_check_flag(np, OF_DETACHED)) {
1265				phandle_cache[handle_hash] = np;
1266				break;
1267			}
1268	}
1269
 
 
 
 
1270	of_node_get(np);
1271	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1272	return np;
1273}
1274EXPORT_SYMBOL(of_find_node_by_phandle);
1275
1276void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1277{
1278	int i;
1279	printk("%s %pOF", msg, args->np);
1280	for (i = 0; i < args->args_count; i++) {
1281		const char delim = i ? ',' : ':';
1282
1283		pr_cont("%c%08x", delim, args->args[i]);
1284	}
1285	pr_cont("\n");
1286}
1287
1288int of_phandle_iterator_init(struct of_phandle_iterator *it,
1289		const struct device_node *np,
1290		const char *list_name,
1291		const char *cells_name,
1292		int cell_count)
1293{
1294	const __be32 *list;
1295	int size;
1296
1297	memset(it, 0, sizeof(*it));
1298
1299	/*
1300	 * one of cell_count or cells_name must be provided to determine the
1301	 * argument length.
1302	 */
1303	if (cell_count < 0 && !cells_name)
1304		return -EINVAL;
1305
1306	list = of_get_property(np, list_name, &size);
1307	if (!list)
1308		return -ENOENT;
1309
1310	it->cells_name = cells_name;
1311	it->cell_count = cell_count;
1312	it->parent = np;
1313	it->list_end = list + size / sizeof(*list);
1314	it->phandle_end = list;
1315	it->cur = list;
1316
1317	return 0;
1318}
1319EXPORT_SYMBOL_GPL(of_phandle_iterator_init);
1320
1321int of_phandle_iterator_next(struct of_phandle_iterator *it)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1322{
1323	uint32_t count = 0;
1324
1325	if (it->node) {
1326		of_node_put(it->node);
1327		it->node = NULL;
1328	}
1329
1330	if (!it->cur || it->phandle_end >= it->list_end)
1331		return -ENOENT;
1332
1333	it->cur = it->phandle_end;
1334
1335	/* If phandle is 0, then it is an empty entry with no arguments. */
1336	it->phandle = be32_to_cpup(it->cur++);
1337
1338	if (it->phandle) {
1339
1340		/*
1341		 * Find the provider node and parse the #*-cells property to
1342		 * determine the argument length.
1343		 */
1344		it->node = of_find_node_by_phandle(it->phandle);
1345
1346		if (it->cells_name) {
1347			if (!it->node) {
1348				pr_err("%pOF: could not find phandle %d\n",
1349				       it->parent, it->phandle);
1350				goto err;
1351			}
1352
1353			if (of_property_read_u32(it->node, it->cells_name,
1354						 &count)) {
1355				/*
1356				 * If both cell_count and cells_name is given,
1357				 * fall back to cell_count in absence
1358				 * of the cells_name property
1359				 */
1360				if (it->cell_count >= 0) {
1361					count = it->cell_count;
1362				} else {
1363					pr_err("%pOF: could not get %s for %pOF\n",
1364					       it->parent,
1365					       it->cells_name,
1366					       it->node);
1367					goto err;
1368				}
1369			}
1370		} else {
1371			count = it->cell_count;
1372		}
1373
1374		/*
1375		 * Make sure that the arguments actually fit in the remaining
1376		 * property data length
1377		 */
1378		if (it->cur + count > it->list_end) {
1379			if (it->cells_name)
1380				pr_err("%pOF: %s = %d found %td\n",
1381					it->parent, it->cells_name,
1382					count, it->list_end - it->cur);
1383			else
1384				pr_err("%pOF: phandle %s needs %d, found %td\n",
1385					it->parent, of_node_full_name(it->node),
1386					count, it->list_end - it->cur);
1387			goto err;
1388		}
1389	}
1390
1391	it->phandle_end = it->cur + count;
1392	it->cur_count = count;
1393
1394	return 0;
1395
1396err:
1397	if (it->node) {
1398		of_node_put(it->node);
1399		it->node = NULL;
1400	}
1401
1402	return -EINVAL;
1403}
1404EXPORT_SYMBOL_GPL(of_phandle_iterator_next);
1405
1406int of_phandle_iterator_args(struct of_phandle_iterator *it,
1407			     uint32_t *args,
1408			     int size)
 
 
 
 
 
 
 
 
 
1409{
1410	int i, count;
 
1411
1412	count = it->cur_count;
1413
1414	if (WARN_ON(size < count))
1415		count = size;
1416
1417	for (i = 0; i < count; i++)
1418		args[i] = be32_to_cpup(it->cur++);
1419
1420	return count;
1421}
1422
1423int __of_parse_phandle_with_args(const struct device_node *np,
1424				 const char *list_name,
1425				 const char *cells_name,
1426				 int cell_count, int index,
1427				 struct of_phandle_args *out_args)
1428{
1429	struct of_phandle_iterator it;
1430	int rc, cur_index = 0;
1431
1432	if (index < 0)
1433		return -EINVAL;
1434
1435	/* Loop over the phandles until all the requested entry is found */
1436	of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
1437		/*
1438		 * All of the error cases bail out of the loop, so at
1439		 * this point, the parsing is successful. If the requested
1440		 * index matches, then fill the out_args structure and return,
1441		 * or return -ENOENT for an empty entry.
1442		 */
1443		rc = -ENOENT;
1444		if (cur_index == index) {
1445			if (!it.phandle)
1446				goto err;
1447
1448			if (out_args) {
1449				int c;
1450
1451				c = of_phandle_iterator_args(&it,
1452							     out_args->args,
1453							     MAX_PHANDLE_ARGS);
1454				out_args->np = it.node;
1455				out_args->args_count = c;
1456			} else {
1457				of_node_put(it.node);
1458			}
1459
1460			/* Found it! return success */
1461			return 0;
1462		}
1463
1464		cur_index++;
1465	}
1466
1467	/*
1468	 * Unlock node before returning result; will be one of:
1469	 * -ENOENT : index is for empty phandle
1470	 * -EINVAL : parsing error on data
1471	 */
1472
1473 err:
1474	of_node_put(it.node);
1475	return rc;
1476}
1477EXPORT_SYMBOL(__of_parse_phandle_with_args);
1478
1479/**
1480 * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it
1481 * @np:		pointer to a device tree node containing a list
1482 * @list_name:	property name that contains a list
1483 * @stem_name:	stem of property names that specify phandles' arguments count
1484 * @index:	index of a phandle to parse out
1485 * @out_args:	optional pointer to output arguments structure (will be filled)
 
1486 *
1487 * This function is useful to parse lists of phandles and their arguments.
1488 * Returns 0 on success and fills out_args, on error returns appropriate errno
1489 * value. The difference between this function and of_parse_phandle_with_args()
1490 * is that this API remaps a phandle if the node the phandle points to has
1491 * a <@stem_name>-map property.
1492 *
1493 * Caller is responsible to call of_node_put() on the returned out_args->np
1494 * pointer.
1495 *
1496 * Example::
1497 *
1498 *  phandle1: node1 {
1499 *  	#list-cells = <2>;
1500 *  };
1501 *
1502 *  phandle2: node2 {
1503 *  	#list-cells = <1>;
1504 *  };
1505 *
1506 *  phandle3: node3 {
1507 *  	#list-cells = <1>;
1508 *  	list-map = <0 &phandle2 3>,
1509 *  		   <1 &phandle2 2>,
1510 *  		   <2 &phandle1 5 1>;
1511 *  	list-map-mask = <0x3>;
1512 *  };
1513 *
1514 *  node4 {
1515 *  	list = <&phandle1 1 2 &phandle3 0>;
1516 *  };
1517 *
1518 * To get a device_node of the ``node2`` node you may call this:
1519 * of_parse_phandle_with_args(node4, "list", "list", 1, &args);
1520 */
1521int of_parse_phandle_with_args_map(const struct device_node *np,
1522				   const char *list_name,
1523				   const char *stem_name,
1524				   int index, struct of_phandle_args *out_args)
1525{
1526	char *cells_name, *map_name = NULL, *mask_name = NULL;
1527	char *pass_name = NULL;
1528	struct device_node *cur, *new = NULL;
1529	const __be32 *map, *mask, *pass;
1530	static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 };
1531	static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = 0 };
1532	__be32 initial_match_array[MAX_PHANDLE_ARGS];
1533	const __be32 *match_array = initial_match_array;
1534	int i, ret, map_len, match;
1535	u32 list_size, new_size;
1536
1537	if (index < 0)
1538		return -EINVAL;
 
 
 
 
1539
1540	cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
1541	if (!cells_name)
1542		return -ENOMEM;
1543
1544	ret = -ENOMEM;
1545	map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name);
1546	if (!map_name)
1547		goto free;
1548
1549	mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
1550	if (!mask_name)
1551		goto free;
1552
1553	pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
1554	if (!pass_name)
1555		goto free;
1556
1557	ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
1558					   out_args);
1559	if (ret)
1560		goto free;
1561
1562	/* Get the #<list>-cells property */
1563	cur = out_args->np;
1564	ret = of_property_read_u32(cur, cells_name, &list_size);
1565	if (ret < 0)
1566		goto put;
1567
1568	/* Precalculate the match array - this simplifies match loop */
1569	for (i = 0; i < list_size; i++)
1570		initial_match_array[i] = cpu_to_be32(out_args->args[i]);
1571
1572	ret = -EINVAL;
1573	while (cur) {
1574		/* Get the <list>-map property */
1575		map = of_get_property(cur, map_name, &map_len);
1576		if (!map) {
1577			ret = 0;
1578			goto free;
1579		}
1580		map_len /= sizeof(u32);
1581
1582		/* Get the <list>-map-mask property (optional) */
1583		mask = of_get_property(cur, mask_name, NULL);
1584		if (!mask)
1585			mask = dummy_mask;
1586		/* Iterate through <list>-map property */
1587		match = 0;
1588		while (map_len > (list_size + 1) && !match) {
1589			/* Compare specifiers */
1590			match = 1;
1591			for (i = 0; i < list_size; i++, map_len--)
1592				match &= !((match_array[i] ^ *map++) & mask[i]);
1593
1594			of_node_put(new);
1595			new = of_find_node_by_phandle(be32_to_cpup(map));
1596			map++;
1597			map_len--;
1598
1599			/* Check if not found */
1600			if (!new)
1601				goto put;
1602
1603			if (!of_device_is_available(new))
1604				match = 0;
1605
1606			ret = of_property_read_u32(new, cells_name, &new_size);
1607			if (ret)
1608				goto put;
1609
1610			/* Check for malformed properties */
1611			if (WARN_ON(new_size > MAX_PHANDLE_ARGS))
1612				goto put;
1613			if (map_len < new_size)
1614				goto put;
1615
1616			/* Move forward by new node's #<list>-cells amount */
1617			map += new_size;
1618			map_len -= new_size;
1619		}
1620		if (!match)
1621			goto put;
1622
1623		/* Get the <list>-map-pass-thru property (optional) */
1624		pass = of_get_property(cur, pass_name, NULL);
1625		if (!pass)
1626			pass = dummy_pass;
1627
1628		/*
1629		 * Successfully parsed a <list>-map translation; copy new
1630		 * specifier into the out_args structure, keeping the
1631		 * bits specified in <list>-map-pass-thru.
1632		 */
1633		match_array = map - new_size;
1634		for (i = 0; i < new_size; i++) {
1635			__be32 val = *(map - new_size + i);
1636
1637			if (i < list_size) {
1638				val &= ~pass[i];
1639				val |= cpu_to_be32(out_args->args[i]) & pass[i];
1640			}
1641
1642			out_args->args[i] = be32_to_cpu(val);
 
 
 
 
1643		}
1644		out_args->args_count = list_size = new_size;
1645		/* Iterate again with new provider */
1646		out_args->np = new;
1647		of_node_put(cur);
1648		cur = new;
1649	}
1650put:
1651	of_node_put(cur);
1652	of_node_put(new);
1653free:
1654	kfree(mask_name);
1655	kfree(map_name);
1656	kfree(cells_name);
1657	kfree(pass_name);
1658
1659	return ret;
1660}
1661EXPORT_SYMBOL(of_parse_phandle_with_args_map);
 
 
 
 
 
 
1662
1663/**
1664 * of_count_phandle_with_args() - Find the number of phandles references in a property
1665 * @np:		pointer to a device tree node containing a list
1666 * @list_name:	property name that contains a list
1667 * @cells_name:	property name that specifies phandles' arguments count
1668 *
1669 * Return: The number of phandle + argument tuples within a property. It
1670 * is a typical pattern to encode a list of phandle and variable
1671 * arguments into a single property. The number of arguments is encoded
1672 * by a property in the phandle-target node. For example, a gpios
1673 * property would contain a list of GPIO specifies consisting of a
1674 * phandle and 1 or more arguments. The number of arguments are
1675 * determined by the #gpio-cells property in the node pointed to by the
1676 * phandle.
1677 */
1678int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1679				const char *cells_name)
1680{
1681	struct of_phandle_iterator it;
1682	int rc, cur_index = 0;
1683
1684	/*
1685	 * If cells_name is NULL we assume a cell count of 0. This makes
1686	 * counting the phandles trivial as each 32bit word in the list is a
1687	 * phandle and no arguments are to consider. So we don't iterate through
1688	 * the list but just use the length to determine the phandle count.
1689	 */
1690	if (!cells_name) {
1691		const __be32 *list;
1692		int size;
1693
1694		list = of_get_property(np, list_name, &size);
1695		if (!list)
1696			return -ENOENT;
1697
1698		return size / sizeof(*list);
 
 
 
 
 
 
 
 
 
1699	}
1700
1701	rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
1702	if (rc)
1703		return rc;
 
1704
1705	while ((rc = of_phandle_iterator_next(&it)) == 0)
1706		cur_index += 1;
1707
1708	if (rc != -ENOENT)
1709		return rc;
1710
1711	return cur_index;
1712}
1713EXPORT_SYMBOL(of_count_phandle_with_args);
1714
1715/**
1716 * __of_add_property - Add a property to a node without lock operations
1717 * @np:		Caller's Device Node
1718 * @prop:	Property to add
1719 */
1720int __of_add_property(struct device_node *np, struct property *prop)
1721{
1722	struct property **next;
 
1723
1724	prop->next = NULL;
 
1725	next = &np->properties;
1726	while (*next) {
1727		if (strcmp(prop->name, (*next)->name) == 0)
1728			/* duplicate ! don't insert it */
1729			return -EEXIST;
1730
 
1731		next = &(*next)->next;
1732	}
1733	*next = prop;
 
1734
1735	return 0;
1736}
1737
1738/**
1739 * of_add_property - Add a property to a node
1740 * @np:		Caller's Device Node
1741 * @prop:	Property to add
1742 */
1743int of_add_property(struct device_node *np, struct property *prop)
1744{
1745	unsigned long flags;
1746	int rc;
1747
1748	mutex_lock(&of_mutex);
1749
1750	raw_spin_lock_irqsave(&devtree_lock, flags);
1751	rc = __of_add_property(np, prop);
1752	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1753
1754	if (!rc)
1755		__of_add_property_sysfs(np, prop);
1756
1757	mutex_unlock(&of_mutex);
1758
1759	if (!rc)
1760		of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1761
1762	return rc;
1763}
1764EXPORT_SYMBOL_GPL(of_add_property);
1765
1766int __of_remove_property(struct device_node *np, struct property *prop)
1767{
1768	struct property **next;
1769
1770	for (next = &np->properties; *next; next = &(*next)->next) {
1771		if (*next == prop)
1772			break;
1773	}
1774	if (*next == NULL)
1775		return -ENODEV;
1776
1777	/* found the node */
1778	*next = prop->next;
1779	prop->next = np->deadprops;
1780	np->deadprops = prop;
1781
1782	return 0;
1783}
1784
1785/**
1786 * of_remove_property - Remove a property from a node.
1787 * @np:		Caller's Device Node
1788 * @prop:	Property to remove
1789 *
1790 * Note that we don't actually remove it, since we have given out
1791 * who-knows-how-many pointers to the data using get-property.
1792 * Instead we just move the property to the "dead properties"
1793 * list, so it won't be found any more.
1794 */
1795int of_remove_property(struct device_node *np, struct property *prop)
1796{
 
1797	unsigned long flags;
1798	int rc;
1799
1800	if (!prop)
1801		return -ENODEV;
1802
1803	mutex_lock(&of_mutex);
1804
1805	raw_spin_lock_irqsave(&devtree_lock, flags);
1806	rc = __of_remove_property(np, prop);
1807	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1808
1809	if (!rc)
1810		__of_remove_property_sysfs(np, prop);
1811
1812	mutex_unlock(&of_mutex);
1813
1814	if (!rc)
1815		of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1816
1817	return rc;
1818}
1819EXPORT_SYMBOL_GPL(of_remove_property);
1820
1821int __of_update_property(struct device_node *np, struct property *newprop,
1822		struct property **oldpropp)
1823{
1824	struct property **next, *oldprop;
1825
1826	for (next = &np->properties; *next; next = &(*next)->next) {
1827		if (of_prop_cmp((*next)->name, newprop->name) == 0)
1828			break;
 
 
1829	}
1830	*oldpropp = oldprop = *next;
 
 
 
1831
1832	if (oldprop) {
1833		/* replace the node */
1834		newprop->next = oldprop->next;
1835		*next = newprop;
1836		oldprop->next = np->deadprops;
1837		np->deadprops = oldprop;
1838	} else {
1839		/* new node */
1840		newprop->next = NULL;
1841		*next = newprop;
1842	}
1843
1844	return 0;
1845}
1846
1847/*
1848 * of_update_property - Update a property in a node, if the property does
1849 * not exist, add it.
1850 *
1851 * Note that we don't actually remove it, since we have given out
1852 * who-knows-how-many pointers to the data using get-property.
1853 * Instead we just move the property to the "dead properties" list,
1854 * and add the new property to the property list
1855 */
1856int of_update_property(struct device_node *np, struct property *newprop)
 
 
1857{
1858	struct property *oldprop;
1859	unsigned long flags;
1860	int rc;
1861
1862	if (!newprop->name)
1863		return -EINVAL;
1864
1865	mutex_lock(&of_mutex);
1866
1867	raw_spin_lock_irqsave(&devtree_lock, flags);
1868	rc = __of_update_property(np, newprop, &oldprop);
1869	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1870
1871	if (!rc)
1872		__of_update_property_sysfs(np, newprop, oldprop);
1873
1874	mutex_unlock(&of_mutex);
1875
1876	if (!rc)
1877		of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1878
1879	return rc;
1880}
1881
1882static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1883			 int id, const char *stem, int stem_len)
1884{
1885	ap->np = np;
1886	ap->id = id;
1887	strncpy(ap->stem, stem, stem_len);
1888	ap->stem[stem_len] = 0;
1889	list_add_tail(&ap->link, &aliases_lookup);
1890	pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n",
1891		 ap->alias, ap->stem, ap->id, np);
1892}
1893
1894/**
1895 * of_alias_scan - Scan all properties of the 'aliases' node
1896 * @dt_alloc:	An allocator that provides a virtual address to memory
1897 *		for storing the resulting tree
1898 *
1899 * The function scans all the properties of the 'aliases' node and populates
1900 * the global lookup table with the properties.  It returns the
1901 * number of alias properties found, or an error code in case of failure.
1902 */
1903void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1904{
1905	struct property *pp;
1906
1907	of_aliases = of_find_node_by_path("/aliases");
1908	of_chosen = of_find_node_by_path("/chosen");
1909	if (of_chosen == NULL)
1910		of_chosen = of_find_node_by_path("/chosen@0");
1911
1912	if (of_chosen) {
1913		/* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1914		const char *name = NULL;
1915
1916		if (of_property_read_string(of_chosen, "stdout-path", &name))
1917			of_property_read_string(of_chosen, "linux,stdout-path",
1918						&name);
1919		if (IS_ENABLED(CONFIG_PPC) && !name)
1920			of_property_read_string(of_aliases, "stdout", &name);
1921		if (name)
1922			of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
1923		if (of_stdout)
1924			of_stdout->fwnode.flags |= FWNODE_FLAG_BEST_EFFORT;
1925	}
1926
1927	if (!of_aliases)
1928		return;
1929
1930	for_each_property_of_node(of_aliases, pp) {
1931		const char *start = pp->name;
1932		const char *end = start + strlen(start);
1933		struct device_node *np;
1934		struct alias_prop *ap;
1935		int id, len;
1936
1937		/* Skip those we do not want to proceed */
1938		if (!strcmp(pp->name, "name") ||
1939		    !strcmp(pp->name, "phandle") ||
1940		    !strcmp(pp->name, "linux,phandle"))
1941			continue;
1942
1943		np = of_find_node_by_path(pp->value);
1944		if (!np)
1945			continue;
1946
1947		/* walk the alias backwards to extract the id and work out
1948		 * the 'stem' string */
1949		while (isdigit(*(end-1)) && end > start)
1950			end--;
1951		len = end - start;
1952
1953		if (kstrtoint(end, 10, &id) < 0)
1954			continue;
1955
1956		/* Allocate an alias_prop with enough space for the stem */
1957		ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap));
1958		if (!ap)
1959			continue;
1960		memset(ap, 0, sizeof(*ap) + len + 1);
1961		ap->alias = start;
1962		of_alias_add(ap, np, id, start, len);
1963	}
1964}
1965
1966/**
1967 * of_alias_get_id - Get alias id for the given device_node
1968 * @np:		Pointer to the given device_node
1969 * @stem:	Alias stem of the given device_node
1970 *
1971 * The function travels the lookup table to get the alias id for the given
1972 * device_node and alias stem.
1973 *
1974 * Return: The alias id if found.
1975 */
1976int of_alias_get_id(struct device_node *np, const char *stem)
1977{
1978	struct alias_prop *app;
1979	int id = -ENODEV;
1980
1981	mutex_lock(&of_mutex);
1982	list_for_each_entry(app, &aliases_lookup, link) {
1983		if (strcmp(app->stem, stem) != 0)
1984			continue;
1985
1986		if (np == app->np) {
1987			id = app->id;
1988			break;
1989		}
 
1990	}
1991	mutex_unlock(&of_mutex);
1992
1993	return id;
1994}
1995EXPORT_SYMBOL_GPL(of_alias_get_id);
1996
1997/**
1998 * of_alias_get_highest_id - Get highest alias id for the given stem
1999 * @stem:	Alias stem to be examined
2000 *
2001 * The function travels the lookup table to get the highest alias id for the
2002 * given alias stem.  It returns the alias id if found.
2003 */
2004int of_alias_get_highest_id(const char *stem)
2005{
2006	struct alias_prop *app;
2007	int id = -ENODEV;
2008
2009	mutex_lock(&of_mutex);
2010	list_for_each_entry(app, &aliases_lookup, link) {
2011		if (strcmp(app->stem, stem) != 0)
2012			continue;
 
2013
2014		if (app->id > id)
2015			id = app->id;
2016	}
2017	mutex_unlock(&of_mutex);
2018
2019	return id;
2020}
2021EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
2022
2023/**
2024 * of_console_check() - Test and setup console for DT setup
2025 * @dn: Pointer to device node
2026 * @name: Name to use for preferred console without index. ex. "ttyS"
2027 * @index: Index to use for preferred console.
2028 *
2029 * Check if the given device node matches the stdout-path property in the
2030 * /chosen node. If it does then register it as the preferred console.
2031 *
2032 * Return: TRUE if console successfully setup. Otherwise return FALSE.
2033 */
2034bool of_console_check(struct device_node *dn, char *name, int index)
2035{
2036	if (!dn || dn != of_stdout || console_set_on_cmdline)
2037		return false;
2038
2039	/*
2040	 * XXX: cast `options' to char pointer to suppress complication
2041	 * warnings: printk, UART and console drivers expect char pointer.
2042	 */
2043	return !add_preferred_console(name, index, (char *)of_stdout_options);
2044}
2045EXPORT_SYMBOL_GPL(of_console_check);
2046
2047/**
2048 * of_find_next_cache_node - Find a node's subsidiary cache
2049 * @np:	node of type "cpu" or "cache"
2050 *
2051 * Return: A node pointer with refcount incremented, use
2052 * of_node_put() on it when done.  Caller should hold a reference
2053 * to np.
2054 */
2055struct device_node *of_find_next_cache_node(const struct device_node *np)
2056{
2057	struct device_node *child, *cache_node;
2058
2059	cache_node = of_parse_phandle(np, "l2-cache", 0);
2060	if (!cache_node)
2061		cache_node = of_parse_phandle(np, "next-level-cache", 0);
2062
2063	if (cache_node)
2064		return cache_node;
2065
2066	/* OF on pmac has nodes instead of properties named "l2-cache"
2067	 * beneath CPU nodes.
2068	 */
2069	if (IS_ENABLED(CONFIG_PPC_PMAC) && of_node_is_type(np, "cpu"))
2070		for_each_child_of_node(np, child)
2071			if (of_node_is_type(child, "cache"))
2072				return child;
2073
2074	return NULL;
2075}
2076
2077/**
2078 * of_find_last_cache_level - Find the level at which the last cache is
2079 * 		present for the given logical cpu
2080 *
2081 * @cpu: cpu number(logical index) for which the last cache level is needed
2082 *
2083 * Return: The level at which the last cache is present. It is exactly
2084 * same as  the total number of cache levels for the given logical cpu.
2085 */
2086int of_find_last_cache_level(unsigned int cpu)
2087{
2088	u32 cache_level = 0;
2089	struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
2090
2091	while (np) {
2092		of_node_put(prev);
2093		prev = np;
2094		np = of_find_next_cache_node(np);
2095	}
2096
2097	of_property_read_u32(prev, "cache-level", &cache_level);
2098	of_node_put(prev);
2099
2100	return cache_level;
 
 
2101}
2102
2103/**
2104 * of_map_id - Translate an ID through a downstream mapping.
2105 * @np: root complex device node.
2106 * @id: device ID to map.
2107 * @map_name: property name of the map to use.
2108 * @map_mask_name: optional property name of the mask to use.
2109 * @target: optional pointer to a target device node.
2110 * @id_out: optional pointer to receive the translated ID.
2111 *
2112 * Given a device ID, look up the appropriate implementation-defined
2113 * platform ID and/or the target device which receives transactions on that
2114 * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
2115 * @id_out may be NULL if only the other is required. If @target points to
2116 * a non-NULL device node pointer, only entries targeting that node will be
2117 * matched; if it points to a NULL value, it will receive the device node of
2118 * the first matching target phandle, with a reference held.
2119 *
2120 * Return: 0 on success or a standard error code on failure.
 
2121 */
2122int of_map_id(struct device_node *np, u32 id,
2123	       const char *map_name, const char *map_mask_name,
2124	       struct device_node **target, u32 *id_out)
2125{
2126	u32 map_mask, masked_id;
2127	int map_len;
2128	const __be32 *map = NULL;
2129
2130	if (!np || !map_name || (!target && !id_out))
2131		return -EINVAL;
2132
2133	map = of_get_property(np, map_name, &map_len);
2134	if (!map) {
2135		if (target)
2136			return -ENODEV;
2137		/* Otherwise, no map implies no translation */
2138		*id_out = id;
2139		return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2140	}
2141
2142	if (!map_len || map_len % (4 * sizeof(*map))) {
2143		pr_err("%pOF: Error: Bad %s length: %d\n", np,
2144			map_name, map_len);
2145		return -EINVAL;
2146	}
2147
2148	/* The default is to select all bits. */
2149	map_mask = 0xffffffff;
2150
2151	/*
2152	 * Can be overridden by "{iommu,msi}-map-mask" property.
2153	 * If of_property_read_u32() fails, the default is used.
2154	 */
2155	if (map_mask_name)
2156		of_property_read_u32(np, map_mask_name, &map_mask);
2157
2158	masked_id = map_mask & id;
2159	for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
2160		struct device_node *phandle_node;
2161		u32 id_base = be32_to_cpup(map + 0);
2162		u32 phandle = be32_to_cpup(map + 1);
2163		u32 out_base = be32_to_cpup(map + 2);
2164		u32 id_len = be32_to_cpup(map + 3);
2165
2166		if (id_base & ~map_mask) {
2167			pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores id-base (0x%x)\n",
2168				np, map_name, map_name,
2169				map_mask, id_base);
2170			return -EFAULT;
2171		}
2172
2173		if (masked_id < id_base || masked_id >= id_base + id_len)
2174			continue;
2175
2176		phandle_node = of_find_node_by_phandle(phandle);
2177		if (!phandle_node)
2178			return -ENODEV;
2179
2180		if (target) {
2181			if (*target)
2182				of_node_put(phandle_node);
2183			else
2184				*target = phandle_node;
2185
2186			if (*target != phandle_node)
2187				continue;
2188		}
2189
2190		if (id_out)
2191			*id_out = masked_id - id_base + out_base;
2192
2193		pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
2194			np, map_name, map_mask, id_base, out_base,
2195			id_len, id, masked_id - id_base + out_base);
2196		return 0;
2197	}
2198
2199	pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name,
2200		id, target && *target ? *target : NULL);
2201
2202	/* Bypasses translation */
2203	if (id_out)
2204		*id_out = id;
2205	return 0;
2206}
2207EXPORT_SYMBOL_GPL(of_map_id);