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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 of_platform_register_reconfig_notifier();
171
172 /* Create the kset, and register existing nodes */
173 mutex_lock(&of_mutex);
174 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
175 if (!of_kset) {
176 mutex_unlock(&of_mutex);
177 pr_err("failed to register existing nodes\n");
178 return;
179 }
180 for_each_of_allnodes(np) {
181 __of_attach_node_sysfs(np);
182 if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)])
183 phandle_cache[of_phandle_cache_hash(np->phandle)] = np;
184 }
185 mutex_unlock(&of_mutex);
186
187 /* Symlink in /proc as required by userspace ABI */
188 if (of_root)
189 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
190}
191
192static struct property *__of_find_property(const struct device_node *np,
193 const char *name, int *lenp)
194{
195 struct property *pp;
196
197 if (!np)
198 return NULL;
199
200 for (pp = np->properties; pp; pp = pp->next) {
201 if (of_prop_cmp(pp->name, name) == 0) {
202 if (lenp)
203 *lenp = pp->length;
204 break;
205 }
206 }
207
208 return pp;
209}
210
211struct property *of_find_property(const struct device_node *np,
212 const char *name,
213 int *lenp)
214{
215 struct property *pp;
216 unsigned long flags;
217
218 raw_spin_lock_irqsave(&devtree_lock, flags);
219 pp = __of_find_property(np, name, lenp);
220 raw_spin_unlock_irqrestore(&devtree_lock, flags);
221
222 return pp;
223}
224EXPORT_SYMBOL(of_find_property);
225
226struct device_node *__of_find_all_nodes(struct device_node *prev)
227{
228 struct device_node *np;
229 if (!prev) {
230 np = of_root;
231 } else if (prev->child) {
232 np = prev->child;
233 } else {
234 /* Walk back up looking for a sibling, or the end of the structure */
235 np = prev;
236 while (np->parent && !np->sibling)
237 np = np->parent;
238 np = np->sibling; /* Might be null at the end of the tree */
239 }
240 return np;
241}
242
243/**
244 * of_find_all_nodes - Get next node in global list
245 * @prev: Previous node or NULL to start iteration
246 * of_node_put() will be called on it
247 *
248 * Return: A node pointer with refcount incremented, use
249 * of_node_put() on it when done.
250 */
251struct device_node *of_find_all_nodes(struct device_node *prev)
252{
253 struct device_node *np;
254 unsigned long flags;
255
256 raw_spin_lock_irqsave(&devtree_lock, flags);
257 np = __of_find_all_nodes(prev);
258 of_node_get(np);
259 of_node_put(prev);
260 raw_spin_unlock_irqrestore(&devtree_lock, flags);
261 return np;
262}
263EXPORT_SYMBOL(of_find_all_nodes);
264
265/*
266 * Find a property with a given name for a given node
267 * and return the value.
268 */
269const void *__of_get_property(const struct device_node *np,
270 const char *name, int *lenp)
271{
272 struct property *pp = __of_find_property(np, name, lenp);
273
274 return pp ? pp->value : NULL;
275}
276
277/*
278 * Find a property with a given name for a given node
279 * and return the value.
280 */
281const void *of_get_property(const struct device_node *np, const char *name,
282 int *lenp)
283{
284 struct property *pp = of_find_property(np, name, lenp);
285
286 return pp ? pp->value : NULL;
287}
288EXPORT_SYMBOL(of_get_property);
289
290/**
291 * __of_device_is_compatible() - Check if the node matches given constraints
292 * @device: pointer to node
293 * @compat: required compatible string, NULL or "" for any match
294 * @type: required device_type value, NULL or "" for any match
295 * @name: required node name, NULL or "" for any match
296 *
297 * Checks if the given @compat, @type and @name strings match the
298 * properties of the given @device. A constraints can be skipped by
299 * passing NULL or an empty string as the constraint.
300 *
301 * Returns 0 for no match, and a positive integer on match. The return
302 * value is a relative score with larger values indicating better
303 * matches. The score is weighted for the most specific compatible value
304 * to get the highest score. Matching type is next, followed by matching
305 * name. Practically speaking, this results in the following priority
306 * order for matches:
307 *
308 * 1. specific compatible && type && name
309 * 2. specific compatible && type
310 * 3. specific compatible && name
311 * 4. specific compatible
312 * 5. general compatible && type && name
313 * 6. general compatible && type
314 * 7. general compatible && name
315 * 8. general compatible
316 * 9. type && name
317 * 10. type
318 * 11. name
319 */
320static int __of_device_is_compatible(const struct device_node *device,
321 const char *compat, const char *type, const char *name)
322{
323 struct property *prop;
324 const char *cp;
325 int index = 0, score = 0;
326
327 /* Compatible match has highest priority */
328 if (compat && compat[0]) {
329 prop = __of_find_property(device, "compatible", NULL);
330 for (cp = of_prop_next_string(prop, NULL); cp;
331 cp = of_prop_next_string(prop, cp), index++) {
332 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
333 score = INT_MAX/2 - (index << 2);
334 break;
335 }
336 }
337 if (!score)
338 return 0;
339 }
340
341 /* Matching type is better than matching name */
342 if (type && type[0]) {
343 if (!__of_node_is_type(device, type))
344 return 0;
345 score += 2;
346 }
347
348 /* Matching name is a bit better than not */
349 if (name && name[0]) {
350 if (!of_node_name_eq(device, name))
351 return 0;
352 score++;
353 }
354
355 return score;
356}
357
358/** Checks if the given "compat" string matches one of the strings in
359 * the device's "compatible" property
360 */
361int of_device_is_compatible(const struct device_node *device,
362 const char *compat)
363{
364 unsigned long flags;
365 int res;
366
367 raw_spin_lock_irqsave(&devtree_lock, flags);
368 res = __of_device_is_compatible(device, compat, NULL, NULL);
369 raw_spin_unlock_irqrestore(&devtree_lock, flags);
370 return res;
371}
372EXPORT_SYMBOL(of_device_is_compatible);
373
374/** Checks if the device is compatible with any of the entries in
375 * a NULL terminated array of strings. Returns the best match
376 * score or 0.
377 */
378int of_device_compatible_match(const struct device_node *device,
379 const char *const *compat)
380{
381 unsigned int tmp, score = 0;
382
383 if (!compat)
384 return 0;
385
386 while (*compat) {
387 tmp = of_device_is_compatible(device, *compat);
388 if (tmp > score)
389 score = tmp;
390 compat++;
391 }
392
393 return score;
394}
395EXPORT_SYMBOL_GPL(of_device_compatible_match);
396
397/**
398 * of_machine_is_compatible - Test root of device tree for a given compatible value
399 * @compat: compatible string to look for in root node's compatible property.
400 *
401 * Return: A positive integer if the root node has the given value in its
402 * compatible property.
403 */
404int of_machine_is_compatible(const char *compat)
405{
406 struct device_node *root;
407 int rc = 0;
408
409 root = of_find_node_by_path("/");
410 if (root) {
411 rc = of_device_is_compatible(root, compat);
412 of_node_put(root);
413 }
414 return rc;
415}
416EXPORT_SYMBOL(of_machine_is_compatible);
417
418/**
419 * __of_device_is_available - check if a device is available for use
420 *
421 * @device: Node to check for availability, with locks already held
422 *
423 * Return: True if the status property is absent or set to "okay" or "ok",
424 * false otherwise
425 */
426static bool __of_device_is_available(const struct device_node *device)
427{
428 const char *status;
429 int statlen;
430
431 if (!device)
432 return false;
433
434 status = __of_get_property(device, "status", &statlen);
435 if (status == NULL)
436 return true;
437
438 if (statlen > 0) {
439 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
440 return true;
441 }
442
443 return false;
444}
445
446/**
447 * of_device_is_available - check if a device is available for use
448 *
449 * @device: Node to check for availability
450 *
451 * Return: True if the status property is absent or set to "okay" or "ok",
452 * false otherwise
453 */
454bool of_device_is_available(const struct device_node *device)
455{
456 unsigned long flags;
457 bool res;
458
459 raw_spin_lock_irqsave(&devtree_lock, flags);
460 res = __of_device_is_available(device);
461 raw_spin_unlock_irqrestore(&devtree_lock, flags);
462 return res;
463
464}
465EXPORT_SYMBOL(of_device_is_available);
466
467/**
468 * __of_device_is_fail - check if a device has status "fail" or "fail-..."
469 *
470 * @device: Node to check status for, with locks already held
471 *
472 * Return: True if the status property is set to "fail" or "fail-..." (for any
473 * error code suffix), false otherwise
474 */
475static bool __of_device_is_fail(const struct device_node *device)
476{
477 const char *status;
478
479 if (!device)
480 return false;
481
482 status = __of_get_property(device, "status", NULL);
483 if (status == NULL)
484 return false;
485
486 return !strcmp(status, "fail") || !strncmp(status, "fail-", 5);
487}
488
489/**
490 * of_device_is_big_endian - check if a device has BE registers
491 *
492 * @device: Node to check for endianness
493 *
494 * Return: True if the device has a "big-endian" property, or if the kernel
495 * was compiled for BE *and* the device has a "native-endian" property.
496 * Returns false otherwise.
497 *
498 * Callers would nominally use ioread32be/iowrite32be if
499 * of_device_is_big_endian() == true, or readl/writel otherwise.
500 */
501bool of_device_is_big_endian(const struct device_node *device)
502{
503 if (of_property_read_bool(device, "big-endian"))
504 return true;
505 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
506 of_property_read_bool(device, "native-endian"))
507 return true;
508 return false;
509}
510EXPORT_SYMBOL(of_device_is_big_endian);
511
512/**
513 * of_get_parent - Get a node's parent if any
514 * @node: Node to get parent
515 *
516 * Return: A node pointer with refcount incremented, use
517 * of_node_put() on it when done.
518 */
519struct device_node *of_get_parent(const struct device_node *node)
520{
521 struct device_node *np;
522 unsigned long flags;
523
524 if (!node)
525 return NULL;
526
527 raw_spin_lock_irqsave(&devtree_lock, flags);
528 np = of_node_get(node->parent);
529 raw_spin_unlock_irqrestore(&devtree_lock, flags);
530 return np;
531}
532EXPORT_SYMBOL(of_get_parent);
533
534/**
535 * of_get_next_parent - Iterate to a node's parent
536 * @node: Node to get parent of
537 *
538 * This is like of_get_parent() except that it drops the
539 * refcount on the passed node, making it suitable for iterating
540 * through a node's parents.
541 *
542 * Return: A node pointer with refcount incremented, use
543 * of_node_put() on it when done.
544 */
545struct device_node *of_get_next_parent(struct device_node *node)
546{
547 struct device_node *parent;
548 unsigned long flags;
549
550 if (!node)
551 return NULL;
552
553 raw_spin_lock_irqsave(&devtree_lock, flags);
554 parent = of_node_get(node->parent);
555 of_node_put(node);
556 raw_spin_unlock_irqrestore(&devtree_lock, flags);
557 return parent;
558}
559EXPORT_SYMBOL(of_get_next_parent);
560
561static struct device_node *__of_get_next_child(const struct device_node *node,
562 struct device_node *prev)
563{
564 struct device_node *next;
565
566 if (!node)
567 return NULL;
568
569 next = prev ? prev->sibling : node->child;
570 of_node_get(next);
571 of_node_put(prev);
572 return next;
573}
574#define __for_each_child_of_node(parent, child) \
575 for (child = __of_get_next_child(parent, NULL); child != NULL; \
576 child = __of_get_next_child(parent, child))
577
578/**
579 * of_get_next_child - Iterate a node childs
580 * @node: parent node
581 * @prev: previous child of the parent node, or NULL to get first
582 *
583 * Return: A node pointer with refcount incremented, use of_node_put() on
584 * it when done. Returns NULL when prev is the last child. Decrements the
585 * refcount of prev.
586 */
587struct device_node *of_get_next_child(const struct device_node *node,
588 struct device_node *prev)
589{
590 struct device_node *next;
591 unsigned long flags;
592
593 raw_spin_lock_irqsave(&devtree_lock, flags);
594 next = __of_get_next_child(node, prev);
595 raw_spin_unlock_irqrestore(&devtree_lock, flags);
596 return next;
597}
598EXPORT_SYMBOL(of_get_next_child);
599
600/**
601 * of_get_next_available_child - Find the next available child node
602 * @node: parent node
603 * @prev: previous child of the parent node, or NULL to get first
604 *
605 * This function is like of_get_next_child(), except that it
606 * automatically skips any disabled nodes (i.e. status = "disabled").
607 */
608struct device_node *of_get_next_available_child(const struct device_node *node,
609 struct device_node *prev)
610{
611 struct device_node *next;
612 unsigned long flags;
613
614 if (!node)
615 return NULL;
616
617 raw_spin_lock_irqsave(&devtree_lock, flags);
618 next = prev ? prev->sibling : node->child;
619 for (; next; next = next->sibling) {
620 if (!__of_device_is_available(next))
621 continue;
622 if (of_node_get(next))
623 break;
624 }
625 of_node_put(prev);
626 raw_spin_unlock_irqrestore(&devtree_lock, flags);
627 return next;
628}
629EXPORT_SYMBOL(of_get_next_available_child);
630
631/**
632 * of_get_next_cpu_node - Iterate on cpu nodes
633 * @prev: previous child of the /cpus node, or NULL to get first
634 *
635 * Unusable CPUs (those with the status property set to "fail" or "fail-...")
636 * will be skipped.
637 *
638 * Return: A cpu node pointer with refcount incremented, use of_node_put()
639 * on it when done. Returns NULL when prev is the last child. Decrements
640 * the refcount of prev.
641 */
642struct device_node *of_get_next_cpu_node(struct device_node *prev)
643{
644 struct device_node *next = NULL;
645 unsigned long flags;
646 struct device_node *node;
647
648 if (!prev)
649 node = of_find_node_by_path("/cpus");
650
651 raw_spin_lock_irqsave(&devtree_lock, flags);
652 if (prev)
653 next = prev->sibling;
654 else if (node) {
655 next = node->child;
656 of_node_put(node);
657 }
658 for (; next; next = next->sibling) {
659 if (__of_device_is_fail(next))
660 continue;
661 if (!(of_node_name_eq(next, "cpu") ||
662 __of_node_is_type(next, "cpu")))
663 continue;
664 if (of_node_get(next))
665 break;
666 }
667 of_node_put(prev);
668 raw_spin_unlock_irqrestore(&devtree_lock, flags);
669 return next;
670}
671EXPORT_SYMBOL(of_get_next_cpu_node);
672
673/**
674 * of_get_compatible_child - Find compatible child node
675 * @parent: parent node
676 * @compatible: compatible string
677 *
678 * Lookup child node whose compatible property contains the given compatible
679 * string.
680 *
681 * Return: a node pointer with refcount incremented, use of_node_put() on it
682 * when done; or NULL if not found.
683 */
684struct device_node *of_get_compatible_child(const struct device_node *parent,
685 const char *compatible)
686{
687 struct device_node *child;
688
689 for_each_child_of_node(parent, child) {
690 if (of_device_is_compatible(child, compatible))
691 break;
692 }
693
694 return child;
695}
696EXPORT_SYMBOL(of_get_compatible_child);
697
698/**
699 * of_get_child_by_name - Find the child node by name for a given parent
700 * @node: parent node
701 * @name: child name to look for.
702 *
703 * This function looks for child node for given matching name
704 *
705 * Return: A node pointer if found, with refcount incremented, use
706 * of_node_put() on it when done.
707 * Returns NULL if node is not found.
708 */
709struct device_node *of_get_child_by_name(const struct device_node *node,
710 const char *name)
711{
712 struct device_node *child;
713
714 for_each_child_of_node(node, child)
715 if (of_node_name_eq(child, name))
716 break;
717 return child;
718}
719EXPORT_SYMBOL(of_get_child_by_name);
720
721struct device_node *__of_find_node_by_path(struct device_node *parent,
722 const char *path)
723{
724 struct device_node *child;
725 int len;
726
727 len = strcspn(path, "/:");
728 if (!len)
729 return NULL;
730
731 __for_each_child_of_node(parent, child) {
732 const char *name = kbasename(child->full_name);
733 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
734 return child;
735 }
736 return NULL;
737}
738
739struct device_node *__of_find_node_by_full_path(struct device_node *node,
740 const char *path)
741{
742 const char *separator = strchr(path, ':');
743
744 while (node && *path == '/') {
745 struct device_node *tmp = node;
746
747 path++; /* Increment past '/' delimiter */
748 node = __of_find_node_by_path(node, path);
749 of_node_put(tmp);
750 path = strchrnul(path, '/');
751 if (separator && separator < path)
752 break;
753 }
754 return node;
755}
756
757/**
758 * of_find_node_opts_by_path - Find a node matching a full OF path
759 * @path: Either the full path to match, or if the path does not
760 * start with '/', the name of a property of the /aliases
761 * node (an alias). In the case of an alias, the node
762 * matching the alias' value will be returned.
763 * @opts: Address of a pointer into which to store the start of
764 * an options string appended to the end of the path with
765 * a ':' separator.
766 *
767 * Valid paths:
768 * * /foo/bar Full path
769 * * foo Valid alias
770 * * foo/bar Valid alias + relative path
771 *
772 * Return: A node pointer with refcount incremented, use
773 * of_node_put() on it when done.
774 */
775struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
776{
777 struct device_node *np = NULL;
778 struct property *pp;
779 unsigned long flags;
780 const char *separator = strchr(path, ':');
781
782 if (opts)
783 *opts = separator ? separator + 1 : NULL;
784
785 if (strcmp(path, "/") == 0)
786 return of_node_get(of_root);
787
788 /* The path could begin with an alias */
789 if (*path != '/') {
790 int len;
791 const char *p = separator;
792
793 if (!p)
794 p = strchrnul(path, '/');
795 len = p - path;
796
797 /* of_aliases must not be NULL */
798 if (!of_aliases)
799 return NULL;
800
801 for_each_property_of_node(of_aliases, pp) {
802 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
803 np = of_find_node_by_path(pp->value);
804 break;
805 }
806 }
807 if (!np)
808 return NULL;
809 path = p;
810 }
811
812 /* Step down the tree matching path components */
813 raw_spin_lock_irqsave(&devtree_lock, flags);
814 if (!np)
815 np = of_node_get(of_root);
816 np = __of_find_node_by_full_path(np, path);
817 raw_spin_unlock_irqrestore(&devtree_lock, flags);
818 return np;
819}
820EXPORT_SYMBOL(of_find_node_opts_by_path);
821
822/**
823 * of_find_node_by_name - Find a node by its "name" property
824 * @from: The node to start searching from or NULL; the node
825 * you pass will not be searched, only the next one
826 * will. Typically, you pass what the previous call
827 * returned. of_node_put() will be called on @from.
828 * @name: The name string to match against
829 *
830 * Return: A node pointer with refcount incremented, use
831 * of_node_put() on it when done.
832 */
833struct device_node *of_find_node_by_name(struct device_node *from,
834 const char *name)
835{
836 struct device_node *np;
837 unsigned long flags;
838
839 raw_spin_lock_irqsave(&devtree_lock, flags);
840 for_each_of_allnodes_from(from, np)
841 if (of_node_name_eq(np, name) && of_node_get(np))
842 break;
843 of_node_put(from);
844 raw_spin_unlock_irqrestore(&devtree_lock, flags);
845 return np;
846}
847EXPORT_SYMBOL(of_find_node_by_name);
848
849/**
850 * of_find_node_by_type - Find a node by its "device_type" property
851 * @from: The node to start searching from, or NULL to start searching
852 * the entire device tree. The node you pass will not be
853 * searched, only the next one will; typically, you pass
854 * what the previous call returned. of_node_put() will be
855 * called on from for you.
856 * @type: The type string to match against
857 *
858 * Return: A node pointer with refcount incremented, use
859 * of_node_put() on it when done.
860 */
861struct device_node *of_find_node_by_type(struct device_node *from,
862 const char *type)
863{
864 struct device_node *np;
865 unsigned long flags;
866
867 raw_spin_lock_irqsave(&devtree_lock, flags);
868 for_each_of_allnodes_from(from, np)
869 if (__of_node_is_type(np, type) && of_node_get(np))
870 break;
871 of_node_put(from);
872 raw_spin_unlock_irqrestore(&devtree_lock, flags);
873 return np;
874}
875EXPORT_SYMBOL(of_find_node_by_type);
876
877/**
878 * of_find_compatible_node - Find a node based on type and one of the
879 * tokens in its "compatible" property
880 * @from: The node to start searching from or NULL, the node
881 * you pass will not be searched, only the next one
882 * will; typically, you pass what the previous call
883 * returned. of_node_put() will be called on it
884 * @type: The type string to match "device_type" or NULL to ignore
885 * @compatible: The string to match to one of the tokens in the device
886 * "compatible" list.
887 *
888 * Return: A node pointer with refcount incremented, use
889 * of_node_put() on it when done.
890 */
891struct device_node *of_find_compatible_node(struct device_node *from,
892 const char *type, const char *compatible)
893{
894 struct device_node *np;
895 unsigned long flags;
896
897 raw_spin_lock_irqsave(&devtree_lock, flags);
898 for_each_of_allnodes_from(from, np)
899 if (__of_device_is_compatible(np, compatible, type, NULL) &&
900 of_node_get(np))
901 break;
902 of_node_put(from);
903 raw_spin_unlock_irqrestore(&devtree_lock, flags);
904 return np;
905}
906EXPORT_SYMBOL(of_find_compatible_node);
907
908/**
909 * of_find_node_with_property - Find a node which has a property with
910 * the given name.
911 * @from: The node to start searching from or NULL, the node
912 * you pass will not be searched, only the next one
913 * will; typically, you pass what the previous call
914 * returned. of_node_put() will be called on it
915 * @prop_name: The name of the property to look for.
916 *
917 * Return: A node pointer with refcount incremented, use
918 * of_node_put() on it when done.
919 */
920struct device_node *of_find_node_with_property(struct device_node *from,
921 const char *prop_name)
922{
923 struct device_node *np;
924 struct property *pp;
925 unsigned long flags;
926
927 raw_spin_lock_irqsave(&devtree_lock, flags);
928 for_each_of_allnodes_from(from, np) {
929 for (pp = np->properties; pp; pp = pp->next) {
930 if (of_prop_cmp(pp->name, prop_name) == 0) {
931 of_node_get(np);
932 goto out;
933 }
934 }
935 }
936out:
937 of_node_put(from);
938 raw_spin_unlock_irqrestore(&devtree_lock, flags);
939 return np;
940}
941EXPORT_SYMBOL(of_find_node_with_property);
942
943static
944const struct of_device_id *__of_match_node(const struct of_device_id *matches,
945 const struct device_node *node)
946{
947 const struct of_device_id *best_match = NULL;
948 int score, best_score = 0;
949
950 if (!matches)
951 return NULL;
952
953 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
954 score = __of_device_is_compatible(node, matches->compatible,
955 matches->type, matches->name);
956 if (score > best_score) {
957 best_match = matches;
958 best_score = score;
959 }
960 }
961
962 return best_match;
963}
964
965/**
966 * of_match_node - Tell if a device_node has a matching of_match structure
967 * @matches: array of of device match structures to search in
968 * @node: the of device structure to match against
969 *
970 * Low level utility function used by device matching.
971 */
972const struct of_device_id *of_match_node(const struct of_device_id *matches,
973 const struct device_node *node)
974{
975 const struct of_device_id *match;
976 unsigned long flags;
977
978 raw_spin_lock_irqsave(&devtree_lock, flags);
979 match = __of_match_node(matches, node);
980 raw_spin_unlock_irqrestore(&devtree_lock, flags);
981 return match;
982}
983EXPORT_SYMBOL(of_match_node);
984
985/**
986 * of_find_matching_node_and_match - Find a node based on an of_device_id
987 * match table.
988 * @from: The node to start searching from or NULL, the node
989 * you pass will not be searched, only the next one
990 * will; typically, you pass what the previous call
991 * returned. of_node_put() will be called on it
992 * @matches: array of of device match structures to search in
993 * @match: Updated to point at the matches entry which matched
994 *
995 * Return: A node pointer with refcount incremented, use
996 * of_node_put() on it when done.
997 */
998struct device_node *of_find_matching_node_and_match(struct device_node *from,
999 const struct of_device_id *matches,
1000 const struct of_device_id **match)
1001{
1002 struct device_node *np;
1003 const struct of_device_id *m;
1004 unsigned long flags;
1005
1006 if (match)
1007 *match = NULL;
1008
1009 raw_spin_lock_irqsave(&devtree_lock, flags);
1010 for_each_of_allnodes_from(from, np) {
1011 m = __of_match_node(matches, np);
1012 if (m && of_node_get(np)) {
1013 if (match)
1014 *match = m;
1015 break;
1016 }
1017 }
1018 of_node_put(from);
1019 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1020 return np;
1021}
1022EXPORT_SYMBOL(of_find_matching_node_and_match);
1023
1024/**
1025 * of_alias_from_compatible - Lookup appropriate alias for a device node
1026 * depending on compatible
1027 * @node: pointer to a device tree node
1028 * @alias: Pointer to buffer that alias value will be copied into
1029 * @len: Length of alias value
1030 *
1031 * Based on the value of the compatible property, this routine will attempt
1032 * to choose an appropriate alias value for a particular device tree node.
1033 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1034 * from the first entry in the compatible list property.
1035 *
1036 * Note: The matching on just the "product" side of the compatible is a relic
1037 * from I2C and SPI. Please do not add any new user.
1038 *
1039 * Return: This routine returns 0 on success, <0 on failure.
1040 */
1041int of_alias_from_compatible(const struct device_node *node, char *alias, int len)
1042{
1043 const char *compatible, *p;
1044 int cplen;
1045
1046 compatible = of_get_property(node, "compatible", &cplen);
1047 if (!compatible || strlen(compatible) > cplen)
1048 return -ENODEV;
1049 p = strchr(compatible, ',');
1050 strscpy(alias, p ? p + 1 : compatible, len);
1051 return 0;
1052}
1053EXPORT_SYMBOL_GPL(of_alias_from_compatible);
1054
1055/**
1056 * of_find_node_by_phandle - Find a node given a phandle
1057 * @handle: phandle of the node to find
1058 *
1059 * Return: A node pointer with refcount incremented, use
1060 * of_node_put() on it when done.
1061 */
1062struct device_node *of_find_node_by_phandle(phandle handle)
1063{
1064 struct device_node *np = NULL;
1065 unsigned long flags;
1066 u32 handle_hash;
1067
1068 if (!handle)
1069 return NULL;
1070
1071 handle_hash = of_phandle_cache_hash(handle);
1072
1073 raw_spin_lock_irqsave(&devtree_lock, flags);
1074
1075 if (phandle_cache[handle_hash] &&
1076 handle == phandle_cache[handle_hash]->phandle)
1077 np = phandle_cache[handle_hash];
1078
1079 if (!np) {
1080 for_each_of_allnodes(np)
1081 if (np->phandle == handle &&
1082 !of_node_check_flag(np, OF_DETACHED)) {
1083 phandle_cache[handle_hash] = np;
1084 break;
1085 }
1086 }
1087
1088 of_node_get(np);
1089 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1090 return np;
1091}
1092EXPORT_SYMBOL(of_find_node_by_phandle);
1093
1094void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1095{
1096 int i;
1097 printk("%s %pOF", msg, args->np);
1098 for (i = 0; i < args->args_count; i++) {
1099 const char delim = i ? ',' : ':';
1100
1101 pr_cont("%c%08x", delim, args->args[i]);
1102 }
1103 pr_cont("\n");
1104}
1105
1106int of_phandle_iterator_init(struct of_phandle_iterator *it,
1107 const struct device_node *np,
1108 const char *list_name,
1109 const char *cells_name,
1110 int cell_count)
1111{
1112 const __be32 *list;
1113 int size;
1114
1115 memset(it, 0, sizeof(*it));
1116
1117 /*
1118 * one of cell_count or cells_name must be provided to determine the
1119 * argument length.
1120 */
1121 if (cell_count < 0 && !cells_name)
1122 return -EINVAL;
1123
1124 list = of_get_property(np, list_name, &size);
1125 if (!list)
1126 return -ENOENT;
1127
1128 it->cells_name = cells_name;
1129 it->cell_count = cell_count;
1130 it->parent = np;
1131 it->list_end = list + size / sizeof(*list);
1132 it->phandle_end = list;
1133 it->cur = list;
1134
1135 return 0;
1136}
1137EXPORT_SYMBOL_GPL(of_phandle_iterator_init);
1138
1139int of_phandle_iterator_next(struct of_phandle_iterator *it)
1140{
1141 uint32_t count = 0;
1142
1143 if (it->node) {
1144 of_node_put(it->node);
1145 it->node = NULL;
1146 }
1147
1148 if (!it->cur || it->phandle_end >= it->list_end)
1149 return -ENOENT;
1150
1151 it->cur = it->phandle_end;
1152
1153 /* If phandle is 0, then it is an empty entry with no arguments. */
1154 it->phandle = be32_to_cpup(it->cur++);
1155
1156 if (it->phandle) {
1157
1158 /*
1159 * Find the provider node and parse the #*-cells property to
1160 * determine the argument length.
1161 */
1162 it->node = of_find_node_by_phandle(it->phandle);
1163
1164 if (it->cells_name) {
1165 if (!it->node) {
1166 pr_err("%pOF: could not find phandle %d\n",
1167 it->parent, it->phandle);
1168 goto err;
1169 }
1170
1171 if (of_property_read_u32(it->node, it->cells_name,
1172 &count)) {
1173 /*
1174 * If both cell_count and cells_name is given,
1175 * fall back to cell_count in absence
1176 * of the cells_name property
1177 */
1178 if (it->cell_count >= 0) {
1179 count = it->cell_count;
1180 } else {
1181 pr_err("%pOF: could not get %s for %pOF\n",
1182 it->parent,
1183 it->cells_name,
1184 it->node);
1185 goto err;
1186 }
1187 }
1188 } else {
1189 count = it->cell_count;
1190 }
1191
1192 /*
1193 * Make sure that the arguments actually fit in the remaining
1194 * property data length
1195 */
1196 if (it->cur + count > it->list_end) {
1197 if (it->cells_name)
1198 pr_err("%pOF: %s = %d found %td\n",
1199 it->parent, it->cells_name,
1200 count, it->list_end - it->cur);
1201 else
1202 pr_err("%pOF: phandle %s needs %d, found %td\n",
1203 it->parent, of_node_full_name(it->node),
1204 count, it->list_end - it->cur);
1205 goto err;
1206 }
1207 }
1208
1209 it->phandle_end = it->cur + count;
1210 it->cur_count = count;
1211
1212 return 0;
1213
1214err:
1215 if (it->node) {
1216 of_node_put(it->node);
1217 it->node = NULL;
1218 }
1219
1220 return -EINVAL;
1221}
1222EXPORT_SYMBOL_GPL(of_phandle_iterator_next);
1223
1224int of_phandle_iterator_args(struct of_phandle_iterator *it,
1225 uint32_t *args,
1226 int size)
1227{
1228 int i, count;
1229
1230 count = it->cur_count;
1231
1232 if (WARN_ON(size < count))
1233 count = size;
1234
1235 for (i = 0; i < count; i++)
1236 args[i] = be32_to_cpup(it->cur++);
1237
1238 return count;
1239}
1240
1241int __of_parse_phandle_with_args(const struct device_node *np,
1242 const char *list_name,
1243 const char *cells_name,
1244 int cell_count, int index,
1245 struct of_phandle_args *out_args)
1246{
1247 struct of_phandle_iterator it;
1248 int rc, cur_index = 0;
1249
1250 if (index < 0)
1251 return -EINVAL;
1252
1253 /* Loop over the phandles until all the requested entry is found */
1254 of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
1255 /*
1256 * All of the error cases bail out of the loop, so at
1257 * this point, the parsing is successful. If the requested
1258 * index matches, then fill the out_args structure and return,
1259 * or return -ENOENT for an empty entry.
1260 */
1261 rc = -ENOENT;
1262 if (cur_index == index) {
1263 if (!it.phandle)
1264 goto err;
1265
1266 if (out_args) {
1267 int c;
1268
1269 c = of_phandle_iterator_args(&it,
1270 out_args->args,
1271 MAX_PHANDLE_ARGS);
1272 out_args->np = it.node;
1273 out_args->args_count = c;
1274 } else {
1275 of_node_put(it.node);
1276 }
1277
1278 /* Found it! return success */
1279 return 0;
1280 }
1281
1282 cur_index++;
1283 }
1284
1285 /*
1286 * Unlock node before returning result; will be one of:
1287 * -ENOENT : index is for empty phandle
1288 * -EINVAL : parsing error on data
1289 */
1290
1291 err:
1292 of_node_put(it.node);
1293 return rc;
1294}
1295EXPORT_SYMBOL(__of_parse_phandle_with_args);
1296
1297/**
1298 * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it
1299 * @np: pointer to a device tree node containing a list
1300 * @list_name: property name that contains a list
1301 * @stem_name: stem of property names that specify phandles' arguments count
1302 * @index: index of a phandle to parse out
1303 * @out_args: optional pointer to output arguments structure (will be filled)
1304 *
1305 * This function is useful to parse lists of phandles and their arguments.
1306 * Returns 0 on success and fills out_args, on error returns appropriate errno
1307 * value. The difference between this function and of_parse_phandle_with_args()
1308 * is that this API remaps a phandle if the node the phandle points to has
1309 * a <@stem_name>-map property.
1310 *
1311 * Caller is responsible to call of_node_put() on the returned out_args->np
1312 * pointer.
1313 *
1314 * Example::
1315 *
1316 * phandle1: node1 {
1317 * #list-cells = <2>;
1318 * };
1319 *
1320 * phandle2: node2 {
1321 * #list-cells = <1>;
1322 * };
1323 *
1324 * phandle3: node3 {
1325 * #list-cells = <1>;
1326 * list-map = <0 &phandle2 3>,
1327 * <1 &phandle2 2>,
1328 * <2 &phandle1 5 1>;
1329 * list-map-mask = <0x3>;
1330 * };
1331 *
1332 * node4 {
1333 * list = <&phandle1 1 2 &phandle3 0>;
1334 * };
1335 *
1336 * To get a device_node of the ``node2`` node you may call this:
1337 * of_parse_phandle_with_args(node4, "list", "list", 1, &args);
1338 */
1339int of_parse_phandle_with_args_map(const struct device_node *np,
1340 const char *list_name,
1341 const char *stem_name,
1342 int index, struct of_phandle_args *out_args)
1343{
1344 char *cells_name, *map_name = NULL, *mask_name = NULL;
1345 char *pass_name = NULL;
1346 struct device_node *cur, *new = NULL;
1347 const __be32 *map, *mask, *pass;
1348 static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 };
1349 static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = 0 };
1350 __be32 initial_match_array[MAX_PHANDLE_ARGS];
1351 const __be32 *match_array = initial_match_array;
1352 int i, ret, map_len, match;
1353 u32 list_size, new_size;
1354
1355 if (index < 0)
1356 return -EINVAL;
1357
1358 cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
1359 if (!cells_name)
1360 return -ENOMEM;
1361
1362 ret = -ENOMEM;
1363 map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name);
1364 if (!map_name)
1365 goto free;
1366
1367 mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
1368 if (!mask_name)
1369 goto free;
1370
1371 pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
1372 if (!pass_name)
1373 goto free;
1374
1375 ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
1376 out_args);
1377 if (ret)
1378 goto free;
1379
1380 /* Get the #<list>-cells property */
1381 cur = out_args->np;
1382 ret = of_property_read_u32(cur, cells_name, &list_size);
1383 if (ret < 0)
1384 goto put;
1385
1386 /* Precalculate the match array - this simplifies match loop */
1387 for (i = 0; i < list_size; i++)
1388 initial_match_array[i] = cpu_to_be32(out_args->args[i]);
1389
1390 ret = -EINVAL;
1391 while (cur) {
1392 /* Get the <list>-map property */
1393 map = of_get_property(cur, map_name, &map_len);
1394 if (!map) {
1395 ret = 0;
1396 goto free;
1397 }
1398 map_len /= sizeof(u32);
1399
1400 /* Get the <list>-map-mask property (optional) */
1401 mask = of_get_property(cur, mask_name, NULL);
1402 if (!mask)
1403 mask = dummy_mask;
1404 /* Iterate through <list>-map property */
1405 match = 0;
1406 while (map_len > (list_size + 1) && !match) {
1407 /* Compare specifiers */
1408 match = 1;
1409 for (i = 0; i < list_size; i++, map_len--)
1410 match &= !((match_array[i] ^ *map++) & mask[i]);
1411
1412 of_node_put(new);
1413 new = of_find_node_by_phandle(be32_to_cpup(map));
1414 map++;
1415 map_len--;
1416
1417 /* Check if not found */
1418 if (!new)
1419 goto put;
1420
1421 if (!of_device_is_available(new))
1422 match = 0;
1423
1424 ret = of_property_read_u32(new, cells_name, &new_size);
1425 if (ret)
1426 goto put;
1427
1428 /* Check for malformed properties */
1429 if (WARN_ON(new_size > MAX_PHANDLE_ARGS))
1430 goto put;
1431 if (map_len < new_size)
1432 goto put;
1433
1434 /* Move forward by new node's #<list>-cells amount */
1435 map += new_size;
1436 map_len -= new_size;
1437 }
1438 if (!match)
1439 goto put;
1440
1441 /* Get the <list>-map-pass-thru property (optional) */
1442 pass = of_get_property(cur, pass_name, NULL);
1443 if (!pass)
1444 pass = dummy_pass;
1445
1446 /*
1447 * Successfully parsed a <list>-map translation; copy new
1448 * specifier into the out_args structure, keeping the
1449 * bits specified in <list>-map-pass-thru.
1450 */
1451 match_array = map - new_size;
1452 for (i = 0; i < new_size; i++) {
1453 __be32 val = *(map - new_size + i);
1454
1455 if (i < list_size) {
1456 val &= ~pass[i];
1457 val |= cpu_to_be32(out_args->args[i]) & pass[i];
1458 }
1459
1460 out_args->args[i] = be32_to_cpu(val);
1461 }
1462 out_args->args_count = list_size = new_size;
1463 /* Iterate again with new provider */
1464 out_args->np = new;
1465 of_node_put(cur);
1466 cur = new;
1467 new = NULL;
1468 }
1469put:
1470 of_node_put(cur);
1471 of_node_put(new);
1472free:
1473 kfree(mask_name);
1474 kfree(map_name);
1475 kfree(cells_name);
1476 kfree(pass_name);
1477
1478 return ret;
1479}
1480EXPORT_SYMBOL(of_parse_phandle_with_args_map);
1481
1482/**
1483 * of_count_phandle_with_args() - Find the number of phandles references in a property
1484 * @np: pointer to a device tree node containing a list
1485 * @list_name: property name that contains a list
1486 * @cells_name: property name that specifies phandles' arguments count
1487 *
1488 * Return: The number of phandle + argument tuples within a property. It
1489 * is a typical pattern to encode a list of phandle and variable
1490 * arguments into a single property. The number of arguments is encoded
1491 * by a property in the phandle-target node. For example, a gpios
1492 * property would contain a list of GPIO specifies consisting of a
1493 * phandle and 1 or more arguments. The number of arguments are
1494 * determined by the #gpio-cells property in the node pointed to by the
1495 * phandle.
1496 */
1497int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1498 const char *cells_name)
1499{
1500 struct of_phandle_iterator it;
1501 int rc, cur_index = 0;
1502
1503 /*
1504 * If cells_name is NULL we assume a cell count of 0. This makes
1505 * counting the phandles trivial as each 32bit word in the list is a
1506 * phandle and no arguments are to consider. So we don't iterate through
1507 * the list but just use the length to determine the phandle count.
1508 */
1509 if (!cells_name) {
1510 const __be32 *list;
1511 int size;
1512
1513 list = of_get_property(np, list_name, &size);
1514 if (!list)
1515 return -ENOENT;
1516
1517 return size / sizeof(*list);
1518 }
1519
1520 rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
1521 if (rc)
1522 return rc;
1523
1524 while ((rc = of_phandle_iterator_next(&it)) == 0)
1525 cur_index += 1;
1526
1527 if (rc != -ENOENT)
1528 return rc;
1529
1530 return cur_index;
1531}
1532EXPORT_SYMBOL(of_count_phandle_with_args);
1533
1534static struct property *__of_remove_property_from_list(struct property **list, struct property *prop)
1535{
1536 struct property **next;
1537
1538 for (next = list; *next; next = &(*next)->next) {
1539 if (*next == prop) {
1540 *next = prop->next;
1541 prop->next = NULL;
1542 return prop;
1543 }
1544 }
1545 return NULL;
1546}
1547
1548/**
1549 * __of_add_property - Add a property to a node without lock operations
1550 * @np: Caller's Device Node
1551 * @prop: Property to add
1552 */
1553int __of_add_property(struct device_node *np, struct property *prop)
1554{
1555 int rc = 0;
1556 unsigned long flags;
1557 struct property **next;
1558
1559 raw_spin_lock_irqsave(&devtree_lock, flags);
1560
1561 __of_remove_property_from_list(&np->deadprops, prop);
1562
1563 prop->next = NULL;
1564 next = &np->properties;
1565 while (*next) {
1566 if (strcmp(prop->name, (*next)->name) == 0) {
1567 /* duplicate ! don't insert it */
1568 rc = -EEXIST;
1569 goto out_unlock;
1570 }
1571 next = &(*next)->next;
1572 }
1573 *next = prop;
1574
1575out_unlock:
1576 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1577 if (rc)
1578 return rc;
1579
1580 __of_add_property_sysfs(np, prop);
1581 return 0;
1582}
1583
1584/**
1585 * of_add_property - Add a property to a node
1586 * @np: Caller's Device Node
1587 * @prop: Property to add
1588 */
1589int of_add_property(struct device_node *np, struct property *prop)
1590{
1591 int rc;
1592
1593 mutex_lock(&of_mutex);
1594 rc = __of_add_property(np, prop);
1595 mutex_unlock(&of_mutex);
1596
1597 if (!rc)
1598 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1599
1600 return rc;
1601}
1602EXPORT_SYMBOL_GPL(of_add_property);
1603
1604int __of_remove_property(struct device_node *np, struct property *prop)
1605{
1606 unsigned long flags;
1607 int rc = -ENODEV;
1608
1609 raw_spin_lock_irqsave(&devtree_lock, flags);
1610
1611 if (__of_remove_property_from_list(&np->properties, prop)) {
1612 /* Found the property, add it to deadprops list */
1613 prop->next = np->deadprops;
1614 np->deadprops = prop;
1615 rc = 0;
1616 }
1617
1618 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1619 if (rc)
1620 return rc;
1621
1622 __of_remove_property_sysfs(np, prop);
1623 return 0;
1624}
1625
1626/**
1627 * of_remove_property - Remove a property from a node.
1628 * @np: Caller's Device Node
1629 * @prop: Property to remove
1630 *
1631 * Note that we don't actually remove it, since we have given out
1632 * who-knows-how-many pointers to the data using get-property.
1633 * Instead we just move the property to the "dead properties"
1634 * list, so it won't be found any more.
1635 */
1636int of_remove_property(struct device_node *np, struct property *prop)
1637{
1638 int rc;
1639
1640 if (!prop)
1641 return -ENODEV;
1642
1643 mutex_lock(&of_mutex);
1644 rc = __of_remove_property(np, prop);
1645 mutex_unlock(&of_mutex);
1646
1647 if (!rc)
1648 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1649
1650 return rc;
1651}
1652EXPORT_SYMBOL_GPL(of_remove_property);
1653
1654int __of_update_property(struct device_node *np, struct property *newprop,
1655 struct property **oldpropp)
1656{
1657 struct property **next, *oldprop;
1658 unsigned long flags;
1659
1660 raw_spin_lock_irqsave(&devtree_lock, flags);
1661
1662 __of_remove_property_from_list(&np->deadprops, newprop);
1663
1664 for (next = &np->properties; *next; next = &(*next)->next) {
1665 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1666 break;
1667 }
1668 *oldpropp = oldprop = *next;
1669
1670 if (oldprop) {
1671 /* replace the node */
1672 newprop->next = oldprop->next;
1673 *next = newprop;
1674 oldprop->next = np->deadprops;
1675 np->deadprops = oldprop;
1676 } else {
1677 /* new node */
1678 newprop->next = NULL;
1679 *next = newprop;
1680 }
1681
1682 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1683
1684 __of_update_property_sysfs(np, newprop, oldprop);
1685
1686 return 0;
1687}
1688
1689/*
1690 * of_update_property - Update a property in a node, if the property does
1691 * not exist, add it.
1692 *
1693 * Note that we don't actually remove it, since we have given out
1694 * who-knows-how-many pointers to the data using get-property.
1695 * Instead we just move the property to the "dead properties" list,
1696 * and add the new property to the property list
1697 */
1698int of_update_property(struct device_node *np, struct property *newprop)
1699{
1700 struct property *oldprop;
1701 int rc;
1702
1703 if (!newprop->name)
1704 return -EINVAL;
1705
1706 mutex_lock(&of_mutex);
1707 rc = __of_update_property(np, newprop, &oldprop);
1708 mutex_unlock(&of_mutex);
1709
1710 if (!rc)
1711 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1712
1713 return rc;
1714}
1715
1716static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1717 int id, const char *stem, int stem_len)
1718{
1719 ap->np = np;
1720 ap->id = id;
1721 strscpy(ap->stem, stem, stem_len + 1);
1722 list_add_tail(&ap->link, &aliases_lookup);
1723 pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n",
1724 ap->alias, ap->stem, ap->id, np);
1725}
1726
1727/**
1728 * of_alias_scan - Scan all properties of the 'aliases' node
1729 * @dt_alloc: An allocator that provides a virtual address to memory
1730 * for storing the resulting tree
1731 *
1732 * The function scans all the properties of the 'aliases' node and populates
1733 * the global lookup table with the properties. It returns the
1734 * number of alias properties found, or an error code in case of failure.
1735 */
1736void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1737{
1738 struct property *pp;
1739
1740 of_aliases = of_find_node_by_path("/aliases");
1741 of_chosen = of_find_node_by_path("/chosen");
1742 if (of_chosen == NULL)
1743 of_chosen = of_find_node_by_path("/chosen@0");
1744
1745 if (of_chosen) {
1746 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1747 const char *name = NULL;
1748
1749 if (of_property_read_string(of_chosen, "stdout-path", &name))
1750 of_property_read_string(of_chosen, "linux,stdout-path",
1751 &name);
1752 if (IS_ENABLED(CONFIG_PPC) && !name)
1753 of_property_read_string(of_aliases, "stdout", &name);
1754 if (name)
1755 of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
1756 if (of_stdout)
1757 of_stdout->fwnode.flags |= FWNODE_FLAG_BEST_EFFORT;
1758 }
1759
1760 if (!of_aliases)
1761 return;
1762
1763 for_each_property_of_node(of_aliases, pp) {
1764 const char *start = pp->name;
1765 const char *end = start + strlen(start);
1766 struct device_node *np;
1767 struct alias_prop *ap;
1768 int id, len;
1769
1770 /* Skip those we do not want to proceed */
1771 if (!strcmp(pp->name, "name") ||
1772 !strcmp(pp->name, "phandle") ||
1773 !strcmp(pp->name, "linux,phandle"))
1774 continue;
1775
1776 np = of_find_node_by_path(pp->value);
1777 if (!np)
1778 continue;
1779
1780 /* walk the alias backwards to extract the id and work out
1781 * the 'stem' string */
1782 while (isdigit(*(end-1)) && end > start)
1783 end--;
1784 len = end - start;
1785
1786 if (kstrtoint(end, 10, &id) < 0)
1787 continue;
1788
1789 /* Allocate an alias_prop with enough space for the stem */
1790 ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap));
1791 if (!ap)
1792 continue;
1793 memset(ap, 0, sizeof(*ap) + len + 1);
1794 ap->alias = start;
1795 of_alias_add(ap, np, id, start, len);
1796 }
1797}
1798
1799/**
1800 * of_alias_get_id - Get alias id for the given device_node
1801 * @np: Pointer to the given device_node
1802 * @stem: Alias stem of the given device_node
1803 *
1804 * The function travels the lookup table to get the alias id for the given
1805 * device_node and alias stem.
1806 *
1807 * Return: The alias id if found.
1808 */
1809int of_alias_get_id(struct device_node *np, const char *stem)
1810{
1811 struct alias_prop *app;
1812 int id = -ENODEV;
1813
1814 mutex_lock(&of_mutex);
1815 list_for_each_entry(app, &aliases_lookup, link) {
1816 if (strcmp(app->stem, stem) != 0)
1817 continue;
1818
1819 if (np == app->np) {
1820 id = app->id;
1821 break;
1822 }
1823 }
1824 mutex_unlock(&of_mutex);
1825
1826 return id;
1827}
1828EXPORT_SYMBOL_GPL(of_alias_get_id);
1829
1830/**
1831 * of_alias_get_highest_id - Get highest alias id for the given stem
1832 * @stem: Alias stem to be examined
1833 *
1834 * The function travels the lookup table to get the highest alias id for the
1835 * given alias stem. It returns the alias id if found.
1836 */
1837int of_alias_get_highest_id(const char *stem)
1838{
1839 struct alias_prop *app;
1840 int id = -ENODEV;
1841
1842 mutex_lock(&of_mutex);
1843 list_for_each_entry(app, &aliases_lookup, link) {
1844 if (strcmp(app->stem, stem) != 0)
1845 continue;
1846
1847 if (app->id > id)
1848 id = app->id;
1849 }
1850 mutex_unlock(&of_mutex);
1851
1852 return id;
1853}
1854EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
1855
1856/**
1857 * of_console_check() - Test and setup console for DT setup
1858 * @dn: Pointer to device node
1859 * @name: Name to use for preferred console without index. ex. "ttyS"
1860 * @index: Index to use for preferred console.
1861 *
1862 * Check if the given device node matches the stdout-path property in the
1863 * /chosen node. If it does then register it as the preferred console.
1864 *
1865 * Return: TRUE if console successfully setup. Otherwise return FALSE.
1866 */
1867bool of_console_check(struct device_node *dn, char *name, int index)
1868{
1869 if (!dn || dn != of_stdout || console_set_on_cmdline)
1870 return false;
1871
1872 /*
1873 * XXX: cast `options' to char pointer to suppress complication
1874 * warnings: printk, UART and console drivers expect char pointer.
1875 */
1876 return !add_preferred_console(name, index, (char *)of_stdout_options);
1877}
1878EXPORT_SYMBOL_GPL(of_console_check);
1879
1880/**
1881 * of_find_next_cache_node - Find a node's subsidiary cache
1882 * @np: node of type "cpu" or "cache"
1883 *
1884 * Return: A node pointer with refcount incremented, use
1885 * of_node_put() on it when done. Caller should hold a reference
1886 * to np.
1887 */
1888struct device_node *of_find_next_cache_node(const struct device_node *np)
1889{
1890 struct device_node *child, *cache_node;
1891
1892 cache_node = of_parse_phandle(np, "l2-cache", 0);
1893 if (!cache_node)
1894 cache_node = of_parse_phandle(np, "next-level-cache", 0);
1895
1896 if (cache_node)
1897 return cache_node;
1898
1899 /* OF on pmac has nodes instead of properties named "l2-cache"
1900 * beneath CPU nodes.
1901 */
1902 if (IS_ENABLED(CONFIG_PPC_PMAC) && of_node_is_type(np, "cpu"))
1903 for_each_child_of_node(np, child)
1904 if (of_node_is_type(child, "cache"))
1905 return child;
1906
1907 return NULL;
1908}
1909
1910/**
1911 * of_find_last_cache_level - Find the level at which the last cache is
1912 * present for the given logical cpu
1913 *
1914 * @cpu: cpu number(logical index) for which the last cache level is needed
1915 *
1916 * Return: The level at which the last cache is present. It is exactly
1917 * same as the total number of cache levels for the given logical cpu.
1918 */
1919int of_find_last_cache_level(unsigned int cpu)
1920{
1921 u32 cache_level = 0;
1922 struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
1923
1924 while (np) {
1925 of_node_put(prev);
1926 prev = np;
1927 np = of_find_next_cache_node(np);
1928 }
1929
1930 of_property_read_u32(prev, "cache-level", &cache_level);
1931 of_node_put(prev);
1932
1933 return cache_level;
1934}
1935
1936/**
1937 * of_map_id - Translate an ID through a downstream mapping.
1938 * @np: root complex device node.
1939 * @id: device ID to map.
1940 * @map_name: property name of the map to use.
1941 * @map_mask_name: optional property name of the mask to use.
1942 * @target: optional pointer to a target device node.
1943 * @id_out: optional pointer to receive the translated ID.
1944 *
1945 * Given a device ID, look up the appropriate implementation-defined
1946 * platform ID and/or the target device which receives transactions on that
1947 * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
1948 * @id_out may be NULL if only the other is required. If @target points to
1949 * a non-NULL device node pointer, only entries targeting that node will be
1950 * matched; if it points to a NULL value, it will receive the device node of
1951 * the first matching target phandle, with a reference held.
1952 *
1953 * Return: 0 on success or a standard error code on failure.
1954 */
1955int of_map_id(struct device_node *np, u32 id,
1956 const char *map_name, const char *map_mask_name,
1957 struct device_node **target, u32 *id_out)
1958{
1959 u32 map_mask, masked_id;
1960 int map_len;
1961 const __be32 *map = NULL;
1962
1963 if (!np || !map_name || (!target && !id_out))
1964 return -EINVAL;
1965
1966 map = of_get_property(np, map_name, &map_len);
1967 if (!map) {
1968 if (target)
1969 return -ENODEV;
1970 /* Otherwise, no map implies no translation */
1971 *id_out = id;
1972 return 0;
1973 }
1974
1975 if (!map_len || map_len % (4 * sizeof(*map))) {
1976 pr_err("%pOF: Error: Bad %s length: %d\n", np,
1977 map_name, map_len);
1978 return -EINVAL;
1979 }
1980
1981 /* The default is to select all bits. */
1982 map_mask = 0xffffffff;
1983
1984 /*
1985 * Can be overridden by "{iommu,msi}-map-mask" property.
1986 * If of_property_read_u32() fails, the default is used.
1987 */
1988 if (map_mask_name)
1989 of_property_read_u32(np, map_mask_name, &map_mask);
1990
1991 masked_id = map_mask & id;
1992 for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
1993 struct device_node *phandle_node;
1994 u32 id_base = be32_to_cpup(map + 0);
1995 u32 phandle = be32_to_cpup(map + 1);
1996 u32 out_base = be32_to_cpup(map + 2);
1997 u32 id_len = be32_to_cpup(map + 3);
1998
1999 if (id_base & ~map_mask) {
2000 pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores id-base (0x%x)\n",
2001 np, map_name, map_name,
2002 map_mask, id_base);
2003 return -EFAULT;
2004 }
2005
2006 if (masked_id < id_base || masked_id >= id_base + id_len)
2007 continue;
2008
2009 phandle_node = of_find_node_by_phandle(phandle);
2010 if (!phandle_node)
2011 return -ENODEV;
2012
2013 if (target) {
2014 if (*target)
2015 of_node_put(phandle_node);
2016 else
2017 *target = phandle_node;
2018
2019 if (*target != phandle_node)
2020 continue;
2021 }
2022
2023 if (id_out)
2024 *id_out = masked_id - id_base + out_base;
2025
2026 pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
2027 np, map_name, map_mask, id_base, out_base,
2028 id_len, id, masked_id - id_base + out_base);
2029 return 0;
2030 }
2031
2032 pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name,
2033 id, target && *target ? *target : NULL);
2034
2035 /* Bypasses translation */
2036 if (id_out)
2037 *id_out = id;
2038 return 0;
2039}
2040EXPORT_SYMBOL_GPL(of_map_id);
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
21#define pr_fmt(fmt) "OF: " fmt
22
23#include <linux/console.h>
24#include <linux/ctype.h>
25#include <linux/cpu.h>
26#include <linux/module.h>
27#include <linux/of.h>
28#include <linux/of_graph.h>
29#include <linux/spinlock.h>
30#include <linux/slab.h>
31#include <linux/string.h>
32#include <linux/proc_fs.h>
33
34#include "of_private.h"
35
36LIST_HEAD(aliases_lookup);
37
38struct device_node *of_root;
39EXPORT_SYMBOL(of_root);
40struct device_node *of_chosen;
41struct device_node *of_aliases;
42struct device_node *of_stdout;
43static const char *of_stdout_options;
44
45struct kset *of_kset;
46
47/*
48 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
49 * This mutex must be held whenever modifications are being made to the
50 * device tree. The of_{attach,detach}_node() and
51 * of_{add,remove,update}_property() helpers make sure this happens.
52 */
53DEFINE_MUTEX(of_mutex);
54
55/* use when traversing tree through the child, sibling,
56 * or parent members of struct device_node.
57 */
58DEFINE_RAW_SPINLOCK(devtree_lock);
59
60int of_n_addr_cells(struct device_node *np)
61{
62 const __be32 *ip;
63
64 do {
65 if (np->parent)
66 np = np->parent;
67 ip = of_get_property(np, "#address-cells", NULL);
68 if (ip)
69 return be32_to_cpup(ip);
70 } while (np->parent);
71 /* No #address-cells property for the root node */
72 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
73}
74EXPORT_SYMBOL(of_n_addr_cells);
75
76int of_n_size_cells(struct device_node *np)
77{
78 const __be32 *ip;
79
80 do {
81 if (np->parent)
82 np = np->parent;
83 ip = of_get_property(np, "#size-cells", NULL);
84 if (ip)
85 return be32_to_cpup(ip);
86 } while (np->parent);
87 /* No #size-cells property for the root node */
88 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
89}
90EXPORT_SYMBOL(of_n_size_cells);
91
92#ifdef CONFIG_NUMA
93int __weak of_node_to_nid(struct device_node *np)
94{
95 return NUMA_NO_NODE;
96}
97#endif
98
99#ifndef CONFIG_OF_DYNAMIC
100static void of_node_release(struct kobject *kobj)
101{
102 /* Without CONFIG_OF_DYNAMIC, no nodes gets freed */
103}
104#endif /* CONFIG_OF_DYNAMIC */
105
106struct kobj_type of_node_ktype = {
107 .release = of_node_release,
108};
109
110static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj,
111 struct bin_attribute *bin_attr, char *buf,
112 loff_t offset, size_t count)
113{
114 struct property *pp = container_of(bin_attr, struct property, attr);
115 return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length);
116}
117
118/* always return newly allocated name, caller must free after use */
119static const char *safe_name(struct kobject *kobj, const char *orig_name)
120{
121 const char *name = orig_name;
122 struct kernfs_node *kn;
123 int i = 0;
124
125 /* don't be a hero. After 16 tries give up */
126 while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) {
127 sysfs_put(kn);
128 if (name != orig_name)
129 kfree(name);
130 name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i);
131 }
132
133 if (name == orig_name) {
134 name = kstrdup(orig_name, GFP_KERNEL);
135 } else {
136 pr_warn("Duplicate name in %s, renamed to \"%s\"\n",
137 kobject_name(kobj), name);
138 }
139 return name;
140}
141
142int __of_add_property_sysfs(struct device_node *np, struct property *pp)
143{
144 int rc;
145
146 /* Important: Don't leak passwords */
147 bool secure = strncmp(pp->name, "security-", 9) == 0;
148
149 if (!IS_ENABLED(CONFIG_SYSFS))
150 return 0;
151
152 if (!of_kset || !of_node_is_attached(np))
153 return 0;
154
155 sysfs_bin_attr_init(&pp->attr);
156 pp->attr.attr.name = safe_name(&np->kobj, pp->name);
157 pp->attr.attr.mode = secure ? S_IRUSR : S_IRUGO;
158 pp->attr.size = secure ? 0 : pp->length;
159 pp->attr.read = of_node_property_read;
160
161 rc = sysfs_create_bin_file(&np->kobj, &pp->attr);
162 WARN(rc, "error adding attribute %s to node %s\n", pp->name, np->full_name);
163 return rc;
164}
165
166int __of_attach_node_sysfs(struct device_node *np)
167{
168 const char *name;
169 struct kobject *parent;
170 struct property *pp;
171 int rc;
172
173 if (!IS_ENABLED(CONFIG_SYSFS))
174 return 0;
175
176 if (!of_kset)
177 return 0;
178
179 np->kobj.kset = of_kset;
180 if (!np->parent) {
181 /* Nodes without parents are new top level trees */
182 name = safe_name(&of_kset->kobj, "base");
183 parent = NULL;
184 } else {
185 name = safe_name(&np->parent->kobj, kbasename(np->full_name));
186 parent = &np->parent->kobj;
187 }
188 if (!name)
189 return -ENOMEM;
190 rc = kobject_add(&np->kobj, parent, "%s", name);
191 kfree(name);
192 if (rc)
193 return rc;
194
195 for_each_property_of_node(np, pp)
196 __of_add_property_sysfs(np, pp);
197
198 return 0;
199}
200
201void __init of_core_init(void)
202{
203 struct device_node *np;
204
205 /* Create the kset, and register existing nodes */
206 mutex_lock(&of_mutex);
207 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
208 if (!of_kset) {
209 mutex_unlock(&of_mutex);
210 pr_err("failed to register existing nodes\n");
211 return;
212 }
213 for_each_of_allnodes(np)
214 __of_attach_node_sysfs(np);
215 mutex_unlock(&of_mutex);
216
217 /* Symlink in /proc as required by userspace ABI */
218 if (of_root)
219 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
220}
221
222static struct property *__of_find_property(const struct device_node *np,
223 const char *name, int *lenp)
224{
225 struct property *pp;
226
227 if (!np)
228 return NULL;
229
230 for (pp = np->properties; pp; pp = pp->next) {
231 if (of_prop_cmp(pp->name, name) == 0) {
232 if (lenp)
233 *lenp = pp->length;
234 break;
235 }
236 }
237
238 return pp;
239}
240
241struct property *of_find_property(const struct device_node *np,
242 const char *name,
243 int *lenp)
244{
245 struct property *pp;
246 unsigned long flags;
247
248 raw_spin_lock_irqsave(&devtree_lock, flags);
249 pp = __of_find_property(np, name, lenp);
250 raw_spin_unlock_irqrestore(&devtree_lock, flags);
251
252 return pp;
253}
254EXPORT_SYMBOL(of_find_property);
255
256struct device_node *__of_find_all_nodes(struct device_node *prev)
257{
258 struct device_node *np;
259 if (!prev) {
260 np = of_root;
261 } else if (prev->child) {
262 np = prev->child;
263 } else {
264 /* Walk back up looking for a sibling, or the end of the structure */
265 np = prev;
266 while (np->parent && !np->sibling)
267 np = np->parent;
268 np = np->sibling; /* Might be null at the end of the tree */
269 }
270 return np;
271}
272
273/**
274 * of_find_all_nodes - Get next node in global list
275 * @prev: Previous node or NULL to start iteration
276 * of_node_put() will be called on it
277 *
278 * Returns a node pointer with refcount incremented, use
279 * of_node_put() on it when done.
280 */
281struct device_node *of_find_all_nodes(struct device_node *prev)
282{
283 struct device_node *np;
284 unsigned long flags;
285
286 raw_spin_lock_irqsave(&devtree_lock, flags);
287 np = __of_find_all_nodes(prev);
288 of_node_get(np);
289 of_node_put(prev);
290 raw_spin_unlock_irqrestore(&devtree_lock, flags);
291 return np;
292}
293EXPORT_SYMBOL(of_find_all_nodes);
294
295/*
296 * Find a property with a given name for a given node
297 * and return the value.
298 */
299const void *__of_get_property(const struct device_node *np,
300 const char *name, int *lenp)
301{
302 struct property *pp = __of_find_property(np, name, lenp);
303
304 return pp ? pp->value : NULL;
305}
306
307/*
308 * Find a property with a given name for a given node
309 * and return the value.
310 */
311const void *of_get_property(const struct device_node *np, const char *name,
312 int *lenp)
313{
314 struct property *pp = of_find_property(np, name, lenp);
315
316 return pp ? pp->value : NULL;
317}
318EXPORT_SYMBOL(of_get_property);
319
320/*
321 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
322 *
323 * @cpu: logical cpu index of a core/thread
324 * @phys_id: physical identifier of a core/thread
325 *
326 * CPU logical to physical index mapping is architecture specific.
327 * However this __weak function provides a default match of physical
328 * id to logical cpu index. phys_id provided here is usually values read
329 * from the device tree which must match the hardware internal registers.
330 *
331 * Returns true if the physical identifier and the logical cpu index
332 * correspond to the same core/thread, false otherwise.
333 */
334bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
335{
336 return (u32)phys_id == cpu;
337}
338
339/**
340 * Checks if the given "prop_name" property holds the physical id of the
341 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
342 * NULL, local thread number within the core is returned in it.
343 */
344static bool __of_find_n_match_cpu_property(struct device_node *cpun,
345 const char *prop_name, int cpu, unsigned int *thread)
346{
347 const __be32 *cell;
348 int ac, prop_len, tid;
349 u64 hwid;
350
351 ac = of_n_addr_cells(cpun);
352 cell = of_get_property(cpun, prop_name, &prop_len);
353 if (!cell || !ac)
354 return false;
355 prop_len /= sizeof(*cell) * ac;
356 for (tid = 0; tid < prop_len; tid++) {
357 hwid = of_read_number(cell, ac);
358 if (arch_match_cpu_phys_id(cpu, hwid)) {
359 if (thread)
360 *thread = tid;
361 return true;
362 }
363 cell += ac;
364 }
365 return false;
366}
367
368/*
369 * arch_find_n_match_cpu_physical_id - See if the given device node is
370 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
371 * else false. If 'thread' is non-NULL, the local thread number within the
372 * core is returned in it.
373 */
374bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
375 int cpu, unsigned int *thread)
376{
377 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
378 * for thread ids on PowerPC. If it doesn't exist fallback to
379 * standard "reg" property.
380 */
381 if (IS_ENABLED(CONFIG_PPC) &&
382 __of_find_n_match_cpu_property(cpun,
383 "ibm,ppc-interrupt-server#s",
384 cpu, thread))
385 return true;
386
387 return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
388}
389
390/**
391 * of_get_cpu_node - Get device node associated with the given logical CPU
392 *
393 * @cpu: CPU number(logical index) for which device node is required
394 * @thread: if not NULL, local thread number within the physical core is
395 * returned
396 *
397 * The main purpose of this function is to retrieve the device node for the
398 * given logical CPU index. It should be used to initialize the of_node in
399 * cpu device. Once of_node in cpu device is populated, all the further
400 * references can use that instead.
401 *
402 * CPU logical to physical index mapping is architecture specific and is built
403 * before booting secondary cores. This function uses arch_match_cpu_phys_id
404 * which can be overridden by architecture specific implementation.
405 *
406 * Returns a node pointer for the logical cpu with refcount incremented, use
407 * of_node_put() on it when done. Returns NULL if not found.
408 */
409struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
410{
411 struct device_node *cpun;
412
413 for_each_node_by_type(cpun, "cpu") {
414 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
415 return cpun;
416 }
417 return NULL;
418}
419EXPORT_SYMBOL(of_get_cpu_node);
420
421/**
422 * __of_device_is_compatible() - Check if the node matches given constraints
423 * @device: pointer to node
424 * @compat: required compatible string, NULL or "" for any match
425 * @type: required device_type value, NULL or "" for any match
426 * @name: required node name, NULL or "" for any match
427 *
428 * Checks if the given @compat, @type and @name strings match the
429 * properties of the given @device. A constraints can be skipped by
430 * passing NULL or an empty string as the constraint.
431 *
432 * Returns 0 for no match, and a positive integer on match. The return
433 * value is a relative score with larger values indicating better
434 * matches. The score is weighted for the most specific compatible value
435 * to get the highest score. Matching type is next, followed by matching
436 * name. Practically speaking, this results in the following priority
437 * order for matches:
438 *
439 * 1. specific compatible && type && name
440 * 2. specific compatible && type
441 * 3. specific compatible && name
442 * 4. specific compatible
443 * 5. general compatible && type && name
444 * 6. general compatible && type
445 * 7. general compatible && name
446 * 8. general compatible
447 * 9. type && name
448 * 10. type
449 * 11. name
450 */
451static int __of_device_is_compatible(const struct device_node *device,
452 const char *compat, const char *type, const char *name)
453{
454 struct property *prop;
455 const char *cp;
456 int index = 0, score = 0;
457
458 /* Compatible match has highest priority */
459 if (compat && compat[0]) {
460 prop = __of_find_property(device, "compatible", NULL);
461 for (cp = of_prop_next_string(prop, NULL); cp;
462 cp = of_prop_next_string(prop, cp), index++) {
463 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
464 score = INT_MAX/2 - (index << 2);
465 break;
466 }
467 }
468 if (!score)
469 return 0;
470 }
471
472 /* Matching type is better than matching name */
473 if (type && type[0]) {
474 if (!device->type || of_node_cmp(type, device->type))
475 return 0;
476 score += 2;
477 }
478
479 /* Matching name is a bit better than not */
480 if (name && name[0]) {
481 if (!device->name || of_node_cmp(name, device->name))
482 return 0;
483 score++;
484 }
485
486 return score;
487}
488
489/** Checks if the given "compat" string matches one of the strings in
490 * the device's "compatible" property
491 */
492int of_device_is_compatible(const struct device_node *device,
493 const char *compat)
494{
495 unsigned long flags;
496 int res;
497
498 raw_spin_lock_irqsave(&devtree_lock, flags);
499 res = __of_device_is_compatible(device, compat, NULL, NULL);
500 raw_spin_unlock_irqrestore(&devtree_lock, flags);
501 return res;
502}
503EXPORT_SYMBOL(of_device_is_compatible);
504
505/** Checks if the device is compatible with any of the entries in
506 * a NULL terminated array of strings. Returns the best match
507 * score or 0.
508 */
509int of_device_compatible_match(struct device_node *device,
510 const char *const *compat)
511{
512 unsigned int tmp, score = 0;
513
514 if (!compat)
515 return 0;
516
517 while (*compat) {
518 tmp = of_device_is_compatible(device, *compat);
519 if (tmp > score)
520 score = tmp;
521 compat++;
522 }
523
524 return score;
525}
526
527/**
528 * of_machine_is_compatible - Test root of device tree for a given compatible value
529 * @compat: compatible string to look for in root node's compatible property.
530 *
531 * Returns a positive integer if the root node has the given value in its
532 * compatible property.
533 */
534int of_machine_is_compatible(const char *compat)
535{
536 struct device_node *root;
537 int rc = 0;
538
539 root = of_find_node_by_path("/");
540 if (root) {
541 rc = of_device_is_compatible(root, compat);
542 of_node_put(root);
543 }
544 return rc;
545}
546EXPORT_SYMBOL(of_machine_is_compatible);
547
548/**
549 * __of_device_is_available - check if a device is available for use
550 *
551 * @device: Node to check for availability, with locks already held
552 *
553 * Returns true if the status property is absent or set to "okay" or "ok",
554 * false otherwise
555 */
556static bool __of_device_is_available(const struct device_node *device)
557{
558 const char *status;
559 int statlen;
560
561 if (!device)
562 return false;
563
564 status = __of_get_property(device, "status", &statlen);
565 if (status == NULL)
566 return true;
567
568 if (statlen > 0) {
569 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
570 return true;
571 }
572
573 return false;
574}
575
576/**
577 * of_device_is_available - check if a device is available for use
578 *
579 * @device: Node to check for availability
580 *
581 * Returns true if the status property is absent or set to "okay" or "ok",
582 * false otherwise
583 */
584bool of_device_is_available(const struct device_node *device)
585{
586 unsigned long flags;
587 bool res;
588
589 raw_spin_lock_irqsave(&devtree_lock, flags);
590 res = __of_device_is_available(device);
591 raw_spin_unlock_irqrestore(&devtree_lock, flags);
592 return res;
593
594}
595EXPORT_SYMBOL(of_device_is_available);
596
597/**
598 * of_device_is_big_endian - check if a device has BE registers
599 *
600 * @device: Node to check for endianness
601 *
602 * Returns true if the device has a "big-endian" property, or if the kernel
603 * was compiled for BE *and* the device has a "native-endian" property.
604 * Returns false otherwise.
605 *
606 * Callers would nominally use ioread32be/iowrite32be if
607 * of_device_is_big_endian() == true, or readl/writel otherwise.
608 */
609bool of_device_is_big_endian(const struct device_node *device)
610{
611 if (of_property_read_bool(device, "big-endian"))
612 return true;
613 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
614 of_property_read_bool(device, "native-endian"))
615 return true;
616 return false;
617}
618EXPORT_SYMBOL(of_device_is_big_endian);
619
620/**
621 * of_get_parent - Get a node's parent if any
622 * @node: Node to get parent
623 *
624 * Returns a node pointer with refcount incremented, use
625 * of_node_put() on it when done.
626 */
627struct device_node *of_get_parent(const struct device_node *node)
628{
629 struct device_node *np;
630 unsigned long flags;
631
632 if (!node)
633 return NULL;
634
635 raw_spin_lock_irqsave(&devtree_lock, flags);
636 np = of_node_get(node->parent);
637 raw_spin_unlock_irqrestore(&devtree_lock, flags);
638 return np;
639}
640EXPORT_SYMBOL(of_get_parent);
641
642/**
643 * of_get_next_parent - Iterate to a node's parent
644 * @node: Node to get parent of
645 *
646 * This is like of_get_parent() except that it drops the
647 * refcount on the passed node, making it suitable for iterating
648 * through a node's parents.
649 *
650 * Returns a node pointer with refcount incremented, use
651 * of_node_put() on it when done.
652 */
653struct device_node *of_get_next_parent(struct device_node *node)
654{
655 struct device_node *parent;
656 unsigned long flags;
657
658 if (!node)
659 return NULL;
660
661 raw_spin_lock_irqsave(&devtree_lock, flags);
662 parent = of_node_get(node->parent);
663 of_node_put(node);
664 raw_spin_unlock_irqrestore(&devtree_lock, flags);
665 return parent;
666}
667EXPORT_SYMBOL(of_get_next_parent);
668
669static struct device_node *__of_get_next_child(const struct device_node *node,
670 struct device_node *prev)
671{
672 struct device_node *next;
673
674 if (!node)
675 return NULL;
676
677 next = prev ? prev->sibling : node->child;
678 for (; next; next = next->sibling)
679 if (of_node_get(next))
680 break;
681 of_node_put(prev);
682 return next;
683}
684#define __for_each_child_of_node(parent, child) \
685 for (child = __of_get_next_child(parent, NULL); child != NULL; \
686 child = __of_get_next_child(parent, child))
687
688/**
689 * of_get_next_child - Iterate a node childs
690 * @node: parent node
691 * @prev: previous child of the parent node, or NULL to get first
692 *
693 * Returns a node pointer with refcount incremented, use of_node_put() on
694 * it when done. Returns NULL when prev is the last child. Decrements the
695 * refcount of prev.
696 */
697struct device_node *of_get_next_child(const struct device_node *node,
698 struct device_node *prev)
699{
700 struct device_node *next;
701 unsigned long flags;
702
703 raw_spin_lock_irqsave(&devtree_lock, flags);
704 next = __of_get_next_child(node, prev);
705 raw_spin_unlock_irqrestore(&devtree_lock, flags);
706 return next;
707}
708EXPORT_SYMBOL(of_get_next_child);
709
710/**
711 * of_get_next_available_child - Find the next available child node
712 * @node: parent node
713 * @prev: previous child of the parent node, or NULL to get first
714 *
715 * This function is like of_get_next_child(), except that it
716 * automatically skips any disabled nodes (i.e. status = "disabled").
717 */
718struct device_node *of_get_next_available_child(const struct device_node *node,
719 struct device_node *prev)
720{
721 struct device_node *next;
722 unsigned long flags;
723
724 if (!node)
725 return NULL;
726
727 raw_spin_lock_irqsave(&devtree_lock, flags);
728 next = prev ? prev->sibling : node->child;
729 for (; next; next = next->sibling) {
730 if (!__of_device_is_available(next))
731 continue;
732 if (of_node_get(next))
733 break;
734 }
735 of_node_put(prev);
736 raw_spin_unlock_irqrestore(&devtree_lock, flags);
737 return next;
738}
739EXPORT_SYMBOL(of_get_next_available_child);
740
741/**
742 * of_get_child_by_name - Find the child node by name for a given parent
743 * @node: parent node
744 * @name: child name to look for.
745 *
746 * This function looks for child node for given matching name
747 *
748 * Returns a node pointer if found, with refcount incremented, use
749 * of_node_put() on it when done.
750 * Returns NULL if node is not found.
751 */
752struct device_node *of_get_child_by_name(const struct device_node *node,
753 const char *name)
754{
755 struct device_node *child;
756
757 for_each_child_of_node(node, child)
758 if (child->name && (of_node_cmp(child->name, name) == 0))
759 break;
760 return child;
761}
762EXPORT_SYMBOL(of_get_child_by_name);
763
764static struct device_node *__of_find_node_by_path(struct device_node *parent,
765 const char *path)
766{
767 struct device_node *child;
768 int len;
769
770 len = strcspn(path, "/:");
771 if (!len)
772 return NULL;
773
774 __for_each_child_of_node(parent, child) {
775 const char *name = strrchr(child->full_name, '/');
776 if (WARN(!name, "malformed device_node %s\n", child->full_name))
777 continue;
778 name++;
779 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
780 return child;
781 }
782 return NULL;
783}
784
785/**
786 * of_find_node_opts_by_path - Find a node matching a full OF path
787 * @path: Either the full path to match, or if the path does not
788 * start with '/', the name of a property of the /aliases
789 * node (an alias). In the case of an alias, the node
790 * matching the alias' value will be returned.
791 * @opts: Address of a pointer into which to store the start of
792 * an options string appended to the end of the path with
793 * a ':' separator.
794 *
795 * Valid paths:
796 * /foo/bar Full path
797 * foo Valid alias
798 * foo/bar Valid alias + relative path
799 *
800 * Returns a node pointer with refcount incremented, use
801 * of_node_put() on it when done.
802 */
803struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
804{
805 struct device_node *np = NULL;
806 struct property *pp;
807 unsigned long flags;
808 const char *separator = strchr(path, ':');
809
810 if (opts)
811 *opts = separator ? separator + 1 : NULL;
812
813 if (strcmp(path, "/") == 0)
814 return of_node_get(of_root);
815
816 /* The path could begin with an alias */
817 if (*path != '/') {
818 int len;
819 const char *p = separator;
820
821 if (!p)
822 p = strchrnul(path, '/');
823 len = p - path;
824
825 /* of_aliases must not be NULL */
826 if (!of_aliases)
827 return NULL;
828
829 for_each_property_of_node(of_aliases, pp) {
830 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
831 np = of_find_node_by_path(pp->value);
832 break;
833 }
834 }
835 if (!np)
836 return NULL;
837 path = p;
838 }
839
840 /* Step down the tree matching path components */
841 raw_spin_lock_irqsave(&devtree_lock, flags);
842 if (!np)
843 np = of_node_get(of_root);
844 while (np && *path == '/') {
845 path++; /* Increment past '/' delimiter */
846 np = __of_find_node_by_path(np, path);
847 path = strchrnul(path, '/');
848 if (separator && separator < path)
849 break;
850 }
851 raw_spin_unlock_irqrestore(&devtree_lock, flags);
852 return np;
853}
854EXPORT_SYMBOL(of_find_node_opts_by_path);
855
856/**
857 * of_find_node_by_name - Find a node by its "name" property
858 * @from: The node to start searching from or NULL, the node
859 * you pass will not be searched, only the next one
860 * will; typically, you pass what the previous call
861 * returned. of_node_put() will be called on it
862 * @name: The name string to match against
863 *
864 * Returns a node pointer with refcount incremented, use
865 * of_node_put() on it when done.
866 */
867struct device_node *of_find_node_by_name(struct device_node *from,
868 const char *name)
869{
870 struct device_node *np;
871 unsigned long flags;
872
873 raw_spin_lock_irqsave(&devtree_lock, flags);
874 for_each_of_allnodes_from(from, np)
875 if (np->name && (of_node_cmp(np->name, name) == 0)
876 && of_node_get(np))
877 break;
878 of_node_put(from);
879 raw_spin_unlock_irqrestore(&devtree_lock, flags);
880 return np;
881}
882EXPORT_SYMBOL(of_find_node_by_name);
883
884/**
885 * of_find_node_by_type - Find a node by its "device_type" property
886 * @from: The node to start searching from, or NULL to start searching
887 * the entire device tree. The node you pass will not be
888 * searched, only the next one will; typically, you pass
889 * what the previous call returned. of_node_put() will be
890 * called on from for you.
891 * @type: The type string to match against
892 *
893 * Returns a node pointer with refcount incremented, use
894 * of_node_put() on it when done.
895 */
896struct device_node *of_find_node_by_type(struct device_node *from,
897 const char *type)
898{
899 struct device_node *np;
900 unsigned long flags;
901
902 raw_spin_lock_irqsave(&devtree_lock, flags);
903 for_each_of_allnodes_from(from, np)
904 if (np->type && (of_node_cmp(np->type, type) == 0)
905 && of_node_get(np))
906 break;
907 of_node_put(from);
908 raw_spin_unlock_irqrestore(&devtree_lock, flags);
909 return np;
910}
911EXPORT_SYMBOL(of_find_node_by_type);
912
913/**
914 * of_find_compatible_node - Find a node based on type and one of the
915 * tokens in its "compatible" property
916 * @from: The node to start searching from or NULL, the node
917 * you pass will not be searched, only the next one
918 * will; typically, you pass what the previous call
919 * returned. of_node_put() will be called on it
920 * @type: The type string to match "device_type" or NULL to ignore
921 * @compatible: The string to match to one of the tokens in the device
922 * "compatible" list.
923 *
924 * Returns a node pointer with refcount incremented, use
925 * of_node_put() on it when done.
926 */
927struct device_node *of_find_compatible_node(struct device_node *from,
928 const char *type, const char *compatible)
929{
930 struct device_node *np;
931 unsigned long flags;
932
933 raw_spin_lock_irqsave(&devtree_lock, flags);
934 for_each_of_allnodes_from(from, np)
935 if (__of_device_is_compatible(np, compatible, type, NULL) &&
936 of_node_get(np))
937 break;
938 of_node_put(from);
939 raw_spin_unlock_irqrestore(&devtree_lock, flags);
940 return np;
941}
942EXPORT_SYMBOL(of_find_compatible_node);
943
944/**
945 * of_find_node_with_property - Find a node which has a property with
946 * the given name.
947 * @from: The node to start searching from or NULL, the node
948 * you pass will not be searched, only the next one
949 * will; typically, you pass what the previous call
950 * returned. of_node_put() will be called on it
951 * @prop_name: The name of the property to look for.
952 *
953 * Returns a node pointer with refcount incremented, use
954 * of_node_put() on it when done.
955 */
956struct device_node *of_find_node_with_property(struct device_node *from,
957 const char *prop_name)
958{
959 struct device_node *np;
960 struct property *pp;
961 unsigned long flags;
962
963 raw_spin_lock_irqsave(&devtree_lock, flags);
964 for_each_of_allnodes_from(from, np) {
965 for (pp = np->properties; pp; pp = pp->next) {
966 if (of_prop_cmp(pp->name, prop_name) == 0) {
967 of_node_get(np);
968 goto out;
969 }
970 }
971 }
972out:
973 of_node_put(from);
974 raw_spin_unlock_irqrestore(&devtree_lock, flags);
975 return np;
976}
977EXPORT_SYMBOL(of_find_node_with_property);
978
979static
980const struct of_device_id *__of_match_node(const struct of_device_id *matches,
981 const struct device_node *node)
982{
983 const struct of_device_id *best_match = NULL;
984 int score, best_score = 0;
985
986 if (!matches)
987 return NULL;
988
989 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
990 score = __of_device_is_compatible(node, matches->compatible,
991 matches->type, matches->name);
992 if (score > best_score) {
993 best_match = matches;
994 best_score = score;
995 }
996 }
997
998 return best_match;
999}
1000
1001/**
1002 * of_match_node - Tell if a device_node has a matching of_match structure
1003 * @matches: array of of device match structures to search in
1004 * @node: the of device structure to match against
1005 *
1006 * Low level utility function used by device matching.
1007 */
1008const struct of_device_id *of_match_node(const struct of_device_id *matches,
1009 const struct device_node *node)
1010{
1011 const struct of_device_id *match;
1012 unsigned long flags;
1013
1014 raw_spin_lock_irqsave(&devtree_lock, flags);
1015 match = __of_match_node(matches, node);
1016 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1017 return match;
1018}
1019EXPORT_SYMBOL(of_match_node);
1020
1021/**
1022 * of_find_matching_node_and_match - Find a node based on an of_device_id
1023 * match table.
1024 * @from: The node to start searching from or NULL, the node
1025 * you pass will not be searched, only the next one
1026 * will; typically, you pass what the previous call
1027 * returned. of_node_put() will be called on it
1028 * @matches: array of of device match structures to search in
1029 * @match Updated to point at the matches entry which matched
1030 *
1031 * Returns a node pointer with refcount incremented, use
1032 * of_node_put() on it when done.
1033 */
1034struct device_node *of_find_matching_node_and_match(struct device_node *from,
1035 const struct of_device_id *matches,
1036 const struct of_device_id **match)
1037{
1038 struct device_node *np;
1039 const struct of_device_id *m;
1040 unsigned long flags;
1041
1042 if (match)
1043 *match = NULL;
1044
1045 raw_spin_lock_irqsave(&devtree_lock, flags);
1046 for_each_of_allnodes_from(from, np) {
1047 m = __of_match_node(matches, np);
1048 if (m && of_node_get(np)) {
1049 if (match)
1050 *match = m;
1051 break;
1052 }
1053 }
1054 of_node_put(from);
1055 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1056 return np;
1057}
1058EXPORT_SYMBOL(of_find_matching_node_and_match);
1059
1060/**
1061 * of_modalias_node - Lookup appropriate modalias for a device node
1062 * @node: pointer to a device tree node
1063 * @modalias: Pointer to buffer that modalias value will be copied into
1064 * @len: Length of modalias value
1065 *
1066 * Based on the value of the compatible property, this routine will attempt
1067 * to choose an appropriate modalias value for a particular device tree node.
1068 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1069 * from the first entry in the compatible list property.
1070 *
1071 * This routine returns 0 on success, <0 on failure.
1072 */
1073int of_modalias_node(struct device_node *node, char *modalias, int len)
1074{
1075 const char *compatible, *p;
1076 int cplen;
1077
1078 compatible = of_get_property(node, "compatible", &cplen);
1079 if (!compatible || strlen(compatible) > cplen)
1080 return -ENODEV;
1081 p = strchr(compatible, ',');
1082 strlcpy(modalias, p ? p + 1 : compatible, len);
1083 return 0;
1084}
1085EXPORT_SYMBOL_GPL(of_modalias_node);
1086
1087/**
1088 * of_find_node_by_phandle - Find a node given a phandle
1089 * @handle: phandle of the node to find
1090 *
1091 * Returns a node pointer with refcount incremented, use
1092 * of_node_put() on it when done.
1093 */
1094struct device_node *of_find_node_by_phandle(phandle handle)
1095{
1096 struct device_node *np;
1097 unsigned long flags;
1098
1099 if (!handle)
1100 return NULL;
1101
1102 raw_spin_lock_irqsave(&devtree_lock, flags);
1103 for_each_of_allnodes(np)
1104 if (np->phandle == handle)
1105 break;
1106 of_node_get(np);
1107 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1108 return np;
1109}
1110EXPORT_SYMBOL(of_find_node_by_phandle);
1111
1112/**
1113 * of_property_count_elems_of_size - Count the number of elements in a property
1114 *
1115 * @np: device node from which the property value is to be read.
1116 * @propname: name of the property to be searched.
1117 * @elem_size: size of the individual element
1118 *
1119 * Search for a property in a device node and count the number of elements of
1120 * size elem_size in it. Returns number of elements on sucess, -EINVAL if the
1121 * property does not exist or its length does not match a multiple of elem_size
1122 * and -ENODATA if the property does not have a value.
1123 */
1124int of_property_count_elems_of_size(const struct device_node *np,
1125 const char *propname, int elem_size)
1126{
1127 struct property *prop = of_find_property(np, propname, NULL);
1128
1129 if (!prop)
1130 return -EINVAL;
1131 if (!prop->value)
1132 return -ENODATA;
1133
1134 if (prop->length % elem_size != 0) {
1135 pr_err("size of %s in node %s is not a multiple of %d\n",
1136 propname, np->full_name, elem_size);
1137 return -EINVAL;
1138 }
1139
1140 return prop->length / elem_size;
1141}
1142EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
1143
1144/**
1145 * of_find_property_value_of_size
1146 *
1147 * @np: device node from which the property value is to be read.
1148 * @propname: name of the property to be searched.
1149 * @min: minimum allowed length of property value
1150 * @max: maximum allowed length of property value (0 means unlimited)
1151 * @len: if !=NULL, actual length is written to here
1152 *
1153 * Search for a property in a device node and valid the requested size.
1154 * Returns the property value on success, -EINVAL if the property does not
1155 * exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
1156 * property data is too small or too large.
1157 *
1158 */
1159static void *of_find_property_value_of_size(const struct device_node *np,
1160 const char *propname, u32 min, u32 max, size_t *len)
1161{
1162 struct property *prop = of_find_property(np, propname, NULL);
1163
1164 if (!prop)
1165 return ERR_PTR(-EINVAL);
1166 if (!prop->value)
1167 return ERR_PTR(-ENODATA);
1168 if (prop->length < min)
1169 return ERR_PTR(-EOVERFLOW);
1170 if (max && prop->length > max)
1171 return ERR_PTR(-EOVERFLOW);
1172
1173 if (len)
1174 *len = prop->length;
1175
1176 return prop->value;
1177}
1178
1179/**
1180 * of_property_read_u32_index - Find and read a u32 from a multi-value property.
1181 *
1182 * @np: device node from which the property value is to be read.
1183 * @propname: name of the property to be searched.
1184 * @index: index of the u32 in the list of values
1185 * @out_value: pointer to return value, modified only if no error.
1186 *
1187 * Search for a property in a device node and read nth 32-bit value from
1188 * it. Returns 0 on success, -EINVAL if the property does not exist,
1189 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1190 * property data isn't large enough.
1191 *
1192 * The out_value is modified only if a valid u32 value can be decoded.
1193 */
1194int of_property_read_u32_index(const struct device_node *np,
1195 const char *propname,
1196 u32 index, u32 *out_value)
1197{
1198 const u32 *val = of_find_property_value_of_size(np, propname,
1199 ((index + 1) * sizeof(*out_value)),
1200 0,
1201 NULL);
1202
1203 if (IS_ERR(val))
1204 return PTR_ERR(val);
1205
1206 *out_value = be32_to_cpup(((__be32 *)val) + index);
1207 return 0;
1208}
1209EXPORT_SYMBOL_GPL(of_property_read_u32_index);
1210
1211/**
1212 * of_property_read_variable_u8_array - Find and read an array of u8 from a
1213 * property, with bounds on the minimum and maximum array size.
1214 *
1215 * @np: device node from which the property value is to be read.
1216 * @propname: name of the property to be searched.
1217 * @out_values: pointer to return value, modified only if return value is 0.
1218 * @sz_min: minimum number of array elements to read
1219 * @sz_max: maximum number of array elements to read, if zero there is no
1220 * upper limit on the number of elements in the dts entry but only
1221 * sz_min will be read.
1222 *
1223 * Search for a property in a device node and read 8-bit value(s) from
1224 * it. Returns number of elements read on success, -EINVAL if the property
1225 * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
1226 * if the property data is smaller than sz_min or longer than sz_max.
1227 *
1228 * dts entry of array should be like:
1229 * property = /bits/ 8 <0x50 0x60 0x70>;
1230 *
1231 * The out_values is modified only if a valid u8 value can be decoded.
1232 */
1233int of_property_read_variable_u8_array(const struct device_node *np,
1234 const char *propname, u8 *out_values,
1235 size_t sz_min, size_t sz_max)
1236{
1237 size_t sz, count;
1238 const u8 *val = of_find_property_value_of_size(np, propname,
1239 (sz_min * sizeof(*out_values)),
1240 (sz_max * sizeof(*out_values)),
1241 &sz);
1242
1243 if (IS_ERR(val))
1244 return PTR_ERR(val);
1245
1246 if (!sz_max)
1247 sz = sz_min;
1248 else
1249 sz /= sizeof(*out_values);
1250
1251 count = sz;
1252 while (count--)
1253 *out_values++ = *val++;
1254
1255 return sz;
1256}
1257EXPORT_SYMBOL_GPL(of_property_read_variable_u8_array);
1258
1259/**
1260 * of_property_read_variable_u16_array - Find and read an array of u16 from a
1261 * property, with bounds on the minimum and maximum array size.
1262 *
1263 * @np: device node from which the property value is to be read.
1264 * @propname: name of the property to be searched.
1265 * @out_values: pointer to return value, modified only if return value is 0.
1266 * @sz_min: minimum number of array elements to read
1267 * @sz_max: maximum number of array elements to read, if zero there is no
1268 * upper limit on the number of elements in the dts entry but only
1269 * sz_min will be read.
1270 *
1271 * Search for a property in a device node and read 16-bit value(s) from
1272 * it. Returns number of elements read on success, -EINVAL if the property
1273 * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
1274 * if the property data is smaller than sz_min or longer than sz_max.
1275 *
1276 * dts entry of array should be like:
1277 * property = /bits/ 16 <0x5000 0x6000 0x7000>;
1278 *
1279 * The out_values is modified only if a valid u16 value can be decoded.
1280 */
1281int of_property_read_variable_u16_array(const struct device_node *np,
1282 const char *propname, u16 *out_values,
1283 size_t sz_min, size_t sz_max)
1284{
1285 size_t sz, count;
1286 const __be16 *val = of_find_property_value_of_size(np, propname,
1287 (sz_min * sizeof(*out_values)),
1288 (sz_max * sizeof(*out_values)),
1289 &sz);
1290
1291 if (IS_ERR(val))
1292 return PTR_ERR(val);
1293
1294 if (!sz_max)
1295 sz = sz_min;
1296 else
1297 sz /= sizeof(*out_values);
1298
1299 count = sz;
1300 while (count--)
1301 *out_values++ = be16_to_cpup(val++);
1302
1303 return sz;
1304}
1305EXPORT_SYMBOL_GPL(of_property_read_variable_u16_array);
1306
1307/**
1308 * of_property_read_variable_u32_array - Find and read an array of 32 bit
1309 * integers from a property, with bounds on the minimum and maximum array size.
1310 *
1311 * @np: device node from which the property value is to be read.
1312 * @propname: name of the property to be searched.
1313 * @out_values: pointer to return value, modified only if return value is 0.
1314 * @sz_min: minimum number of array elements to read
1315 * @sz_max: maximum number of array elements to read, if zero there is no
1316 * upper limit on the number of elements in the dts entry but only
1317 * sz_min will be read.
1318 *
1319 * Search for a property in a device node and read 32-bit value(s) from
1320 * it. Returns number of elements read on success, -EINVAL if the property
1321 * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
1322 * if the property data is smaller than sz_min or longer than sz_max.
1323 *
1324 * The out_values is modified only if a valid u32 value can be decoded.
1325 */
1326int of_property_read_variable_u32_array(const struct device_node *np,
1327 const char *propname, u32 *out_values,
1328 size_t sz_min, size_t sz_max)
1329{
1330 size_t sz, count;
1331 const __be32 *val = of_find_property_value_of_size(np, propname,
1332 (sz_min * sizeof(*out_values)),
1333 (sz_max * sizeof(*out_values)),
1334 &sz);
1335
1336 if (IS_ERR(val))
1337 return PTR_ERR(val);
1338
1339 if (!sz_max)
1340 sz = sz_min;
1341 else
1342 sz /= sizeof(*out_values);
1343
1344 count = sz;
1345 while (count--)
1346 *out_values++ = be32_to_cpup(val++);
1347
1348 return sz;
1349}
1350EXPORT_SYMBOL_GPL(of_property_read_variable_u32_array);
1351
1352/**
1353 * of_property_read_u64 - Find and read a 64 bit integer from a property
1354 * @np: device node from which the property value is to be read.
1355 * @propname: name of the property to be searched.
1356 * @out_value: pointer to return value, modified only if return value is 0.
1357 *
1358 * Search for a property in a device node and read a 64-bit value from
1359 * it. Returns 0 on success, -EINVAL if the property does not exist,
1360 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1361 * property data isn't large enough.
1362 *
1363 * The out_value is modified only if a valid u64 value can be decoded.
1364 */
1365int of_property_read_u64(const struct device_node *np, const char *propname,
1366 u64 *out_value)
1367{
1368 const __be32 *val = of_find_property_value_of_size(np, propname,
1369 sizeof(*out_value),
1370 0,
1371 NULL);
1372
1373 if (IS_ERR(val))
1374 return PTR_ERR(val);
1375
1376 *out_value = of_read_number(val, 2);
1377 return 0;
1378}
1379EXPORT_SYMBOL_GPL(of_property_read_u64);
1380
1381/**
1382 * of_property_read_variable_u64_array - Find and read an array of 64 bit
1383 * integers from a property, with bounds on the minimum and maximum array size.
1384 *
1385 * @np: device node from which the property value is to be read.
1386 * @propname: name of the property to be searched.
1387 * @out_values: pointer to return value, modified only if return value is 0.
1388 * @sz_min: minimum number of array elements to read
1389 * @sz_max: maximum number of array elements to read, if zero there is no
1390 * upper limit on the number of elements in the dts entry but only
1391 * sz_min will be read.
1392 *
1393 * Search for a property in a device node and read 64-bit value(s) from
1394 * it. Returns number of elements read on success, -EINVAL if the property
1395 * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
1396 * if the property data is smaller than sz_min or longer than sz_max.
1397 *
1398 * The out_values is modified only if a valid u64 value can be decoded.
1399 */
1400int of_property_read_variable_u64_array(const struct device_node *np,
1401 const char *propname, u64 *out_values,
1402 size_t sz_min, size_t sz_max)
1403{
1404 size_t sz, count;
1405 const __be32 *val = of_find_property_value_of_size(np, propname,
1406 (sz_min * sizeof(*out_values)),
1407 (sz_max * sizeof(*out_values)),
1408 &sz);
1409
1410 if (IS_ERR(val))
1411 return PTR_ERR(val);
1412
1413 if (!sz_max)
1414 sz = sz_min;
1415 else
1416 sz /= sizeof(*out_values);
1417
1418 count = sz;
1419 while (count--) {
1420 *out_values++ = of_read_number(val, 2);
1421 val += 2;
1422 }
1423
1424 return sz;
1425}
1426EXPORT_SYMBOL_GPL(of_property_read_variable_u64_array);
1427
1428/**
1429 * of_property_read_string - Find and read a string from a property
1430 * @np: device node from which the property value is to be read.
1431 * @propname: name of the property to be searched.
1432 * @out_string: pointer to null terminated return string, modified only if
1433 * return value is 0.
1434 *
1435 * Search for a property in a device tree node and retrieve a null
1436 * terminated string value (pointer to data, not a copy). Returns 0 on
1437 * success, -EINVAL if the property does not exist, -ENODATA if property
1438 * does not have a value, and -EILSEQ if the string is not null-terminated
1439 * within the length of the property data.
1440 *
1441 * The out_string pointer is modified only if a valid string can be decoded.
1442 */
1443int of_property_read_string(const struct device_node *np, const char *propname,
1444 const char **out_string)
1445{
1446 const struct property *prop = of_find_property(np, propname, NULL);
1447 if (!prop)
1448 return -EINVAL;
1449 if (!prop->value)
1450 return -ENODATA;
1451 if (strnlen(prop->value, prop->length) >= prop->length)
1452 return -EILSEQ;
1453 *out_string = prop->value;
1454 return 0;
1455}
1456EXPORT_SYMBOL_GPL(of_property_read_string);
1457
1458/**
1459 * of_property_match_string() - Find string in a list and return index
1460 * @np: pointer to node containing string list property
1461 * @propname: string list property name
1462 * @string: pointer to string to search for in string list
1463 *
1464 * This function searches a string list property and returns the index
1465 * of a specific string value.
1466 */
1467int of_property_match_string(const struct device_node *np, const char *propname,
1468 const char *string)
1469{
1470 const struct property *prop = of_find_property(np, propname, NULL);
1471 size_t l;
1472 int i;
1473 const char *p, *end;
1474
1475 if (!prop)
1476 return -EINVAL;
1477 if (!prop->value)
1478 return -ENODATA;
1479
1480 p = prop->value;
1481 end = p + prop->length;
1482
1483 for (i = 0; p < end; i++, p += l) {
1484 l = strnlen(p, end - p) + 1;
1485 if (p + l > end)
1486 return -EILSEQ;
1487 pr_debug("comparing %s with %s\n", string, p);
1488 if (strcmp(string, p) == 0)
1489 return i; /* Found it; return index */
1490 }
1491 return -ENODATA;
1492}
1493EXPORT_SYMBOL_GPL(of_property_match_string);
1494
1495/**
1496 * of_property_read_string_helper() - Utility helper for parsing string properties
1497 * @np: device node from which the property value is to be read.
1498 * @propname: name of the property to be searched.
1499 * @out_strs: output array of string pointers.
1500 * @sz: number of array elements to read.
1501 * @skip: Number of strings to skip over at beginning of list.
1502 *
1503 * Don't call this function directly. It is a utility helper for the
1504 * of_property_read_string*() family of functions.
1505 */
1506int of_property_read_string_helper(const struct device_node *np,
1507 const char *propname, const char **out_strs,
1508 size_t sz, int skip)
1509{
1510 const struct property *prop = of_find_property(np, propname, NULL);
1511 int l = 0, i = 0;
1512 const char *p, *end;
1513
1514 if (!prop)
1515 return -EINVAL;
1516 if (!prop->value)
1517 return -ENODATA;
1518 p = prop->value;
1519 end = p + prop->length;
1520
1521 for (i = 0; p < end && (!out_strs || i < skip + sz); i++, p += l) {
1522 l = strnlen(p, end - p) + 1;
1523 if (p + l > end)
1524 return -EILSEQ;
1525 if (out_strs && i >= skip)
1526 *out_strs++ = p;
1527 }
1528 i -= skip;
1529 return i <= 0 ? -ENODATA : i;
1530}
1531EXPORT_SYMBOL_GPL(of_property_read_string_helper);
1532
1533void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1534{
1535 int i;
1536 printk("%s %s", msg, of_node_full_name(args->np));
1537 for (i = 0; i < args->args_count; i++) {
1538 const char delim = i ? ',' : ':';
1539
1540 pr_cont("%c%08x", delim, args->args[i]);
1541 }
1542 pr_cont("\n");
1543}
1544
1545int of_phandle_iterator_init(struct of_phandle_iterator *it,
1546 const struct device_node *np,
1547 const char *list_name,
1548 const char *cells_name,
1549 int cell_count)
1550{
1551 const __be32 *list;
1552 int size;
1553
1554 memset(it, 0, sizeof(*it));
1555
1556 list = of_get_property(np, list_name, &size);
1557 if (!list)
1558 return -ENOENT;
1559
1560 it->cells_name = cells_name;
1561 it->cell_count = cell_count;
1562 it->parent = np;
1563 it->list_end = list + size / sizeof(*list);
1564 it->phandle_end = list;
1565 it->cur = list;
1566
1567 return 0;
1568}
1569
1570int of_phandle_iterator_next(struct of_phandle_iterator *it)
1571{
1572 uint32_t count = 0;
1573
1574 if (it->node) {
1575 of_node_put(it->node);
1576 it->node = NULL;
1577 }
1578
1579 if (!it->cur || it->phandle_end >= it->list_end)
1580 return -ENOENT;
1581
1582 it->cur = it->phandle_end;
1583
1584 /* If phandle is 0, then it is an empty entry with no arguments. */
1585 it->phandle = be32_to_cpup(it->cur++);
1586
1587 if (it->phandle) {
1588
1589 /*
1590 * Find the provider node and parse the #*-cells property to
1591 * determine the argument length.
1592 */
1593 it->node = of_find_node_by_phandle(it->phandle);
1594
1595 if (it->cells_name) {
1596 if (!it->node) {
1597 pr_err("%s: could not find phandle\n",
1598 it->parent->full_name);
1599 goto err;
1600 }
1601
1602 if (of_property_read_u32(it->node, it->cells_name,
1603 &count)) {
1604 pr_err("%s: could not get %s for %s\n",
1605 it->parent->full_name,
1606 it->cells_name,
1607 it->node->full_name);
1608 goto err;
1609 }
1610 } else {
1611 count = it->cell_count;
1612 }
1613
1614 /*
1615 * Make sure that the arguments actually fit in the remaining
1616 * property data length
1617 */
1618 if (it->cur + count > it->list_end) {
1619 pr_err("%s: arguments longer than property\n",
1620 it->parent->full_name);
1621 goto err;
1622 }
1623 }
1624
1625 it->phandle_end = it->cur + count;
1626 it->cur_count = count;
1627
1628 return 0;
1629
1630err:
1631 if (it->node) {
1632 of_node_put(it->node);
1633 it->node = NULL;
1634 }
1635
1636 return -EINVAL;
1637}
1638
1639int of_phandle_iterator_args(struct of_phandle_iterator *it,
1640 uint32_t *args,
1641 int size)
1642{
1643 int i, count;
1644
1645 count = it->cur_count;
1646
1647 if (WARN_ON(size < count))
1648 count = size;
1649
1650 for (i = 0; i < count; i++)
1651 args[i] = be32_to_cpup(it->cur++);
1652
1653 return count;
1654}
1655
1656static int __of_parse_phandle_with_args(const struct device_node *np,
1657 const char *list_name,
1658 const char *cells_name,
1659 int cell_count, int index,
1660 struct of_phandle_args *out_args)
1661{
1662 struct of_phandle_iterator it;
1663 int rc, cur_index = 0;
1664
1665 /* Loop over the phandles until all the requested entry is found */
1666 of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
1667 /*
1668 * All of the error cases bail out of the loop, so at
1669 * this point, the parsing is successful. If the requested
1670 * index matches, then fill the out_args structure and return,
1671 * or return -ENOENT for an empty entry.
1672 */
1673 rc = -ENOENT;
1674 if (cur_index == index) {
1675 if (!it.phandle)
1676 goto err;
1677
1678 if (out_args) {
1679 int c;
1680
1681 c = of_phandle_iterator_args(&it,
1682 out_args->args,
1683 MAX_PHANDLE_ARGS);
1684 out_args->np = it.node;
1685 out_args->args_count = c;
1686 } else {
1687 of_node_put(it.node);
1688 }
1689
1690 /* Found it! return success */
1691 return 0;
1692 }
1693
1694 cur_index++;
1695 }
1696
1697 /*
1698 * Unlock node before returning result; will be one of:
1699 * -ENOENT : index is for empty phandle
1700 * -EINVAL : parsing error on data
1701 */
1702
1703 err:
1704 of_node_put(it.node);
1705 return rc;
1706}
1707
1708/**
1709 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1710 * @np: Pointer to device node holding phandle property
1711 * @phandle_name: Name of property holding a phandle value
1712 * @index: For properties holding a table of phandles, this is the index into
1713 * the table
1714 *
1715 * Returns the device_node pointer with refcount incremented. Use
1716 * of_node_put() on it when done.
1717 */
1718struct device_node *of_parse_phandle(const struct device_node *np,
1719 const char *phandle_name, int index)
1720{
1721 struct of_phandle_args args;
1722
1723 if (index < 0)
1724 return NULL;
1725
1726 if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1727 index, &args))
1728 return NULL;
1729
1730 return args.np;
1731}
1732EXPORT_SYMBOL(of_parse_phandle);
1733
1734/**
1735 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1736 * @np: pointer to a device tree node containing a list
1737 * @list_name: property name that contains a list
1738 * @cells_name: property name that specifies phandles' arguments count
1739 * @index: index of a phandle to parse out
1740 * @out_args: optional pointer to output arguments structure (will be filled)
1741 *
1742 * This function is useful to parse lists of phandles and their arguments.
1743 * Returns 0 on success and fills out_args, on error returns appropriate
1744 * errno value.
1745 *
1746 * Caller is responsible to call of_node_put() on the returned out_args->np
1747 * pointer.
1748 *
1749 * Example:
1750 *
1751 * phandle1: node1 {
1752 * #list-cells = <2>;
1753 * }
1754 *
1755 * phandle2: node2 {
1756 * #list-cells = <1>;
1757 * }
1758 *
1759 * node3 {
1760 * list = <&phandle1 1 2 &phandle2 3>;
1761 * }
1762 *
1763 * To get a device_node of the `node2' node you may call this:
1764 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1765 */
1766int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1767 const char *cells_name, int index,
1768 struct of_phandle_args *out_args)
1769{
1770 if (index < 0)
1771 return -EINVAL;
1772 return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
1773 index, out_args);
1774}
1775EXPORT_SYMBOL(of_parse_phandle_with_args);
1776
1777/**
1778 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1779 * @np: pointer to a device tree node containing a list
1780 * @list_name: property name that contains a list
1781 * @cell_count: number of argument cells following the phandle
1782 * @index: index of a phandle to parse out
1783 * @out_args: optional pointer to output arguments structure (will be filled)
1784 *
1785 * This function is useful to parse lists of phandles and their arguments.
1786 * Returns 0 on success and fills out_args, on error returns appropriate
1787 * errno value.
1788 *
1789 * Caller is responsible to call of_node_put() on the returned out_args->np
1790 * pointer.
1791 *
1792 * Example:
1793 *
1794 * phandle1: node1 {
1795 * }
1796 *
1797 * phandle2: node2 {
1798 * }
1799 *
1800 * node3 {
1801 * list = <&phandle1 0 2 &phandle2 2 3>;
1802 * }
1803 *
1804 * To get a device_node of the `node2' node you may call this:
1805 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1806 */
1807int of_parse_phandle_with_fixed_args(const struct device_node *np,
1808 const char *list_name, int cell_count,
1809 int index, struct of_phandle_args *out_args)
1810{
1811 if (index < 0)
1812 return -EINVAL;
1813 return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1814 index, out_args);
1815}
1816EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1817
1818/**
1819 * of_count_phandle_with_args() - Find the number of phandles references in a property
1820 * @np: pointer to a device tree node containing a list
1821 * @list_name: property name that contains a list
1822 * @cells_name: property name that specifies phandles' arguments count
1823 *
1824 * Returns the number of phandle + argument tuples within a property. It
1825 * is a typical pattern to encode a list of phandle and variable
1826 * arguments into a single property. The number of arguments is encoded
1827 * by a property in the phandle-target node. For example, a gpios
1828 * property would contain a list of GPIO specifies consisting of a
1829 * phandle and 1 or more arguments. The number of arguments are
1830 * determined by the #gpio-cells property in the node pointed to by the
1831 * phandle.
1832 */
1833int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1834 const char *cells_name)
1835{
1836 struct of_phandle_iterator it;
1837 int rc, cur_index = 0;
1838
1839 rc = of_phandle_iterator_init(&it, np, list_name, cells_name, 0);
1840 if (rc)
1841 return rc;
1842
1843 while ((rc = of_phandle_iterator_next(&it)) == 0)
1844 cur_index += 1;
1845
1846 if (rc != -ENOENT)
1847 return rc;
1848
1849 return cur_index;
1850}
1851EXPORT_SYMBOL(of_count_phandle_with_args);
1852
1853/**
1854 * __of_add_property - Add a property to a node without lock operations
1855 */
1856int __of_add_property(struct device_node *np, struct property *prop)
1857{
1858 struct property **next;
1859
1860 prop->next = NULL;
1861 next = &np->properties;
1862 while (*next) {
1863 if (strcmp(prop->name, (*next)->name) == 0)
1864 /* duplicate ! don't insert it */
1865 return -EEXIST;
1866
1867 next = &(*next)->next;
1868 }
1869 *next = prop;
1870
1871 return 0;
1872}
1873
1874/**
1875 * of_add_property - Add a property to a node
1876 */
1877int of_add_property(struct device_node *np, struct property *prop)
1878{
1879 unsigned long flags;
1880 int rc;
1881
1882 mutex_lock(&of_mutex);
1883
1884 raw_spin_lock_irqsave(&devtree_lock, flags);
1885 rc = __of_add_property(np, prop);
1886 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1887
1888 if (!rc)
1889 __of_add_property_sysfs(np, prop);
1890
1891 mutex_unlock(&of_mutex);
1892
1893 if (!rc)
1894 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1895
1896 return rc;
1897}
1898
1899int __of_remove_property(struct device_node *np, struct property *prop)
1900{
1901 struct property **next;
1902
1903 for (next = &np->properties; *next; next = &(*next)->next) {
1904 if (*next == prop)
1905 break;
1906 }
1907 if (*next == NULL)
1908 return -ENODEV;
1909
1910 /* found the node */
1911 *next = prop->next;
1912 prop->next = np->deadprops;
1913 np->deadprops = prop;
1914
1915 return 0;
1916}
1917
1918void __of_sysfs_remove_bin_file(struct device_node *np, struct property *prop)
1919{
1920 sysfs_remove_bin_file(&np->kobj, &prop->attr);
1921 kfree(prop->attr.attr.name);
1922}
1923
1924void __of_remove_property_sysfs(struct device_node *np, struct property *prop)
1925{
1926 if (!IS_ENABLED(CONFIG_SYSFS))
1927 return;
1928
1929 /* at early boot, bail here and defer setup to of_init() */
1930 if (of_kset && of_node_is_attached(np))
1931 __of_sysfs_remove_bin_file(np, prop);
1932}
1933
1934/**
1935 * of_remove_property - Remove a property from a node.
1936 *
1937 * Note that we don't actually remove it, since we have given out
1938 * who-knows-how-many pointers to the data using get-property.
1939 * Instead we just move the property to the "dead properties"
1940 * list, so it won't be found any more.
1941 */
1942int of_remove_property(struct device_node *np, struct property *prop)
1943{
1944 unsigned long flags;
1945 int rc;
1946
1947 if (!prop)
1948 return -ENODEV;
1949
1950 mutex_lock(&of_mutex);
1951
1952 raw_spin_lock_irqsave(&devtree_lock, flags);
1953 rc = __of_remove_property(np, prop);
1954 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1955
1956 if (!rc)
1957 __of_remove_property_sysfs(np, prop);
1958
1959 mutex_unlock(&of_mutex);
1960
1961 if (!rc)
1962 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1963
1964 return rc;
1965}
1966
1967int __of_update_property(struct device_node *np, struct property *newprop,
1968 struct property **oldpropp)
1969{
1970 struct property **next, *oldprop;
1971
1972 for (next = &np->properties; *next; next = &(*next)->next) {
1973 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1974 break;
1975 }
1976 *oldpropp = oldprop = *next;
1977
1978 if (oldprop) {
1979 /* replace the node */
1980 newprop->next = oldprop->next;
1981 *next = newprop;
1982 oldprop->next = np->deadprops;
1983 np->deadprops = oldprop;
1984 } else {
1985 /* new node */
1986 newprop->next = NULL;
1987 *next = newprop;
1988 }
1989
1990 return 0;
1991}
1992
1993void __of_update_property_sysfs(struct device_node *np, struct property *newprop,
1994 struct property *oldprop)
1995{
1996 if (!IS_ENABLED(CONFIG_SYSFS))
1997 return;
1998
1999 /* At early boot, bail out and defer setup to of_init() */
2000 if (!of_kset)
2001 return;
2002
2003 if (oldprop)
2004 __of_sysfs_remove_bin_file(np, oldprop);
2005 __of_add_property_sysfs(np, newprop);
2006}
2007
2008/*
2009 * of_update_property - Update a property in a node, if the property does
2010 * not exist, add it.
2011 *
2012 * Note that we don't actually remove it, since we have given out
2013 * who-knows-how-many pointers to the data using get-property.
2014 * Instead we just move the property to the "dead properties" list,
2015 * and add the new property to the property list
2016 */
2017int of_update_property(struct device_node *np, struct property *newprop)
2018{
2019 struct property *oldprop;
2020 unsigned long flags;
2021 int rc;
2022
2023 if (!newprop->name)
2024 return -EINVAL;
2025
2026 mutex_lock(&of_mutex);
2027
2028 raw_spin_lock_irqsave(&devtree_lock, flags);
2029 rc = __of_update_property(np, newprop, &oldprop);
2030 raw_spin_unlock_irqrestore(&devtree_lock, flags);
2031
2032 if (!rc)
2033 __of_update_property_sysfs(np, newprop, oldprop);
2034
2035 mutex_unlock(&of_mutex);
2036
2037 if (!rc)
2038 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
2039
2040 return rc;
2041}
2042
2043static void of_alias_add(struct alias_prop *ap, struct device_node *np,
2044 int id, const char *stem, int stem_len)
2045{
2046 ap->np = np;
2047 ap->id = id;
2048 strncpy(ap->stem, stem, stem_len);
2049 ap->stem[stem_len] = 0;
2050 list_add_tail(&ap->link, &aliases_lookup);
2051 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
2052 ap->alias, ap->stem, ap->id, of_node_full_name(np));
2053}
2054
2055/**
2056 * of_alias_scan - Scan all properties of the 'aliases' node
2057 *
2058 * The function scans all the properties of the 'aliases' node and populates
2059 * the global lookup table with the properties. It returns the
2060 * number of alias properties found, or an error code in case of failure.
2061 *
2062 * @dt_alloc: An allocator that provides a virtual address to memory
2063 * for storing the resulting tree
2064 */
2065void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
2066{
2067 struct property *pp;
2068
2069 of_aliases = of_find_node_by_path("/aliases");
2070 of_chosen = of_find_node_by_path("/chosen");
2071 if (of_chosen == NULL)
2072 of_chosen = of_find_node_by_path("/chosen@0");
2073
2074 if (of_chosen) {
2075 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
2076 const char *name = of_get_property(of_chosen, "stdout-path", NULL);
2077 if (!name)
2078 name = of_get_property(of_chosen, "linux,stdout-path", NULL);
2079 if (IS_ENABLED(CONFIG_PPC) && !name)
2080 name = of_get_property(of_aliases, "stdout", NULL);
2081 if (name)
2082 of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
2083 }
2084
2085 if (!of_aliases)
2086 return;
2087
2088 for_each_property_of_node(of_aliases, pp) {
2089 const char *start = pp->name;
2090 const char *end = start + strlen(start);
2091 struct device_node *np;
2092 struct alias_prop *ap;
2093 int id, len;
2094
2095 /* Skip those we do not want to proceed */
2096 if (!strcmp(pp->name, "name") ||
2097 !strcmp(pp->name, "phandle") ||
2098 !strcmp(pp->name, "linux,phandle"))
2099 continue;
2100
2101 np = of_find_node_by_path(pp->value);
2102 if (!np)
2103 continue;
2104
2105 /* walk the alias backwards to extract the id and work out
2106 * the 'stem' string */
2107 while (isdigit(*(end-1)) && end > start)
2108 end--;
2109 len = end - start;
2110
2111 if (kstrtoint(end, 10, &id) < 0)
2112 continue;
2113
2114 /* Allocate an alias_prop with enough space for the stem */
2115 ap = dt_alloc(sizeof(*ap) + len + 1, 4);
2116 if (!ap)
2117 continue;
2118 memset(ap, 0, sizeof(*ap) + len + 1);
2119 ap->alias = start;
2120 of_alias_add(ap, np, id, start, len);
2121 }
2122}
2123
2124/**
2125 * of_alias_get_id - Get alias id for the given device_node
2126 * @np: Pointer to the given device_node
2127 * @stem: Alias stem of the given device_node
2128 *
2129 * The function travels the lookup table to get the alias id for the given
2130 * device_node and alias stem. It returns the alias id if found.
2131 */
2132int of_alias_get_id(struct device_node *np, const char *stem)
2133{
2134 struct alias_prop *app;
2135 int id = -ENODEV;
2136
2137 mutex_lock(&of_mutex);
2138 list_for_each_entry(app, &aliases_lookup, link) {
2139 if (strcmp(app->stem, stem) != 0)
2140 continue;
2141
2142 if (np == app->np) {
2143 id = app->id;
2144 break;
2145 }
2146 }
2147 mutex_unlock(&of_mutex);
2148
2149 return id;
2150}
2151EXPORT_SYMBOL_GPL(of_alias_get_id);
2152
2153/**
2154 * of_alias_get_highest_id - Get highest alias id for the given stem
2155 * @stem: Alias stem to be examined
2156 *
2157 * The function travels the lookup table to get the highest alias id for the
2158 * given alias stem. It returns the alias id if found.
2159 */
2160int of_alias_get_highest_id(const char *stem)
2161{
2162 struct alias_prop *app;
2163 int id = -ENODEV;
2164
2165 mutex_lock(&of_mutex);
2166 list_for_each_entry(app, &aliases_lookup, link) {
2167 if (strcmp(app->stem, stem) != 0)
2168 continue;
2169
2170 if (app->id > id)
2171 id = app->id;
2172 }
2173 mutex_unlock(&of_mutex);
2174
2175 return id;
2176}
2177EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
2178
2179const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
2180 u32 *pu)
2181{
2182 const void *curv = cur;
2183
2184 if (!prop)
2185 return NULL;
2186
2187 if (!cur) {
2188 curv = prop->value;
2189 goto out_val;
2190 }
2191
2192 curv += sizeof(*cur);
2193 if (curv >= prop->value + prop->length)
2194 return NULL;
2195
2196out_val:
2197 *pu = be32_to_cpup(curv);
2198 return curv;
2199}
2200EXPORT_SYMBOL_GPL(of_prop_next_u32);
2201
2202const char *of_prop_next_string(struct property *prop, const char *cur)
2203{
2204 const void *curv = cur;
2205
2206 if (!prop)
2207 return NULL;
2208
2209 if (!cur)
2210 return prop->value;
2211
2212 curv += strlen(cur) + 1;
2213 if (curv >= prop->value + prop->length)
2214 return NULL;
2215
2216 return curv;
2217}
2218EXPORT_SYMBOL_GPL(of_prop_next_string);
2219
2220/**
2221 * of_console_check() - Test and setup console for DT setup
2222 * @dn - Pointer to device node
2223 * @name - Name to use for preferred console without index. ex. "ttyS"
2224 * @index - Index to use for preferred console.
2225 *
2226 * Check if the given device node matches the stdout-path property in the
2227 * /chosen node. If it does then register it as the preferred console and return
2228 * TRUE. Otherwise return FALSE.
2229 */
2230bool of_console_check(struct device_node *dn, char *name, int index)
2231{
2232 if (!dn || dn != of_stdout || console_set_on_cmdline)
2233 return false;
2234 return !add_preferred_console(name, index,
2235 kstrdup(of_stdout_options, GFP_KERNEL));
2236}
2237EXPORT_SYMBOL_GPL(of_console_check);
2238
2239/**
2240 * of_find_next_cache_node - Find a node's subsidiary cache
2241 * @np: node of type "cpu" or "cache"
2242 *
2243 * Returns a node pointer with refcount incremented, use
2244 * of_node_put() on it when done. Caller should hold a reference
2245 * to np.
2246 */
2247struct device_node *of_find_next_cache_node(const struct device_node *np)
2248{
2249 struct device_node *child;
2250 const phandle *handle;
2251
2252 handle = of_get_property(np, "l2-cache", NULL);
2253 if (!handle)
2254 handle = of_get_property(np, "next-level-cache", NULL);
2255
2256 if (handle)
2257 return of_find_node_by_phandle(be32_to_cpup(handle));
2258
2259 /* OF on pmac has nodes instead of properties named "l2-cache"
2260 * beneath CPU nodes.
2261 */
2262 if (!strcmp(np->type, "cpu"))
2263 for_each_child_of_node(np, child)
2264 if (!strcmp(child->type, "cache"))
2265 return child;
2266
2267 return NULL;
2268}
2269
2270/**
2271 * of_graph_parse_endpoint() - parse common endpoint node properties
2272 * @node: pointer to endpoint device_node
2273 * @endpoint: pointer to the OF endpoint data structure
2274 *
2275 * The caller should hold a reference to @node.
2276 */
2277int of_graph_parse_endpoint(const struct device_node *node,
2278 struct of_endpoint *endpoint)
2279{
2280 struct device_node *port_node = of_get_parent(node);
2281
2282 WARN_ONCE(!port_node, "%s(): endpoint %s has no parent node\n",
2283 __func__, node->full_name);
2284
2285 memset(endpoint, 0, sizeof(*endpoint));
2286
2287 endpoint->local_node = node;
2288 /*
2289 * It doesn't matter whether the two calls below succeed.
2290 * If they don't then the default value 0 is used.
2291 */
2292 of_property_read_u32(port_node, "reg", &endpoint->port);
2293 of_property_read_u32(node, "reg", &endpoint->id);
2294
2295 of_node_put(port_node);
2296
2297 return 0;
2298}
2299EXPORT_SYMBOL(of_graph_parse_endpoint);
2300
2301/**
2302 * of_graph_get_port_by_id() - get the port matching a given id
2303 * @parent: pointer to the parent device node
2304 * @id: id of the port
2305 *
2306 * Return: A 'port' node pointer with refcount incremented. The caller
2307 * has to use of_node_put() on it when done.
2308 */
2309struct device_node *of_graph_get_port_by_id(struct device_node *parent, u32 id)
2310{
2311 struct device_node *node, *port;
2312
2313 node = of_get_child_by_name(parent, "ports");
2314 if (node)
2315 parent = node;
2316
2317 for_each_child_of_node(parent, port) {
2318 u32 port_id = 0;
2319
2320 if (of_node_cmp(port->name, "port") != 0)
2321 continue;
2322 of_property_read_u32(port, "reg", &port_id);
2323 if (id == port_id)
2324 break;
2325 }
2326
2327 of_node_put(node);
2328
2329 return port;
2330}
2331EXPORT_SYMBOL(of_graph_get_port_by_id);
2332
2333/**
2334 * of_graph_get_next_endpoint() - get next endpoint node
2335 * @parent: pointer to the parent device node
2336 * @prev: previous endpoint node, or NULL to get first
2337 *
2338 * Return: An 'endpoint' node pointer with refcount incremented. Refcount
2339 * of the passed @prev node is decremented.
2340 */
2341struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
2342 struct device_node *prev)
2343{
2344 struct device_node *endpoint;
2345 struct device_node *port;
2346
2347 if (!parent)
2348 return NULL;
2349
2350 /*
2351 * Start by locating the port node. If no previous endpoint is specified
2352 * search for the first port node, otherwise get the previous endpoint
2353 * parent port node.
2354 */
2355 if (!prev) {
2356 struct device_node *node;
2357
2358 node = of_get_child_by_name(parent, "ports");
2359 if (node)
2360 parent = node;
2361
2362 port = of_get_child_by_name(parent, "port");
2363 of_node_put(node);
2364
2365 if (!port) {
2366 pr_err("graph: no port node found in %s\n",
2367 parent->full_name);
2368 return NULL;
2369 }
2370 } else {
2371 port = of_get_parent(prev);
2372 if (WARN_ONCE(!port, "%s(): endpoint %s has no parent node\n",
2373 __func__, prev->full_name))
2374 return NULL;
2375 }
2376
2377 while (1) {
2378 /*
2379 * Now that we have a port node, get the next endpoint by
2380 * getting the next child. If the previous endpoint is NULL this
2381 * will return the first child.
2382 */
2383 endpoint = of_get_next_child(port, prev);
2384 if (endpoint) {
2385 of_node_put(port);
2386 return endpoint;
2387 }
2388
2389 /* No more endpoints under this port, try the next one. */
2390 prev = NULL;
2391
2392 do {
2393 port = of_get_next_child(parent, port);
2394 if (!port)
2395 return NULL;
2396 } while (of_node_cmp(port->name, "port"));
2397 }
2398}
2399EXPORT_SYMBOL(of_graph_get_next_endpoint);
2400
2401/**
2402 * of_graph_get_endpoint_by_regs() - get endpoint node of specific identifiers
2403 * @parent: pointer to the parent device node
2404 * @port_reg: identifier (value of reg property) of the parent port node
2405 * @reg: identifier (value of reg property) of the endpoint node
2406 *
2407 * Return: An 'endpoint' node pointer which is identified by reg and at the same
2408 * is the child of a port node identified by port_reg. reg and port_reg are
2409 * ignored when they are -1.
2410 */
2411struct device_node *of_graph_get_endpoint_by_regs(
2412 const struct device_node *parent, int port_reg, int reg)
2413{
2414 struct of_endpoint endpoint;
2415 struct device_node *node = NULL;
2416
2417 for_each_endpoint_of_node(parent, node) {
2418 of_graph_parse_endpoint(node, &endpoint);
2419 if (((port_reg == -1) || (endpoint.port == port_reg)) &&
2420 ((reg == -1) || (endpoint.id == reg)))
2421 return node;
2422 }
2423
2424 return NULL;
2425}
2426EXPORT_SYMBOL(of_graph_get_endpoint_by_regs);
2427
2428/**
2429 * of_graph_get_remote_port_parent() - get remote port's parent node
2430 * @node: pointer to a local endpoint device_node
2431 *
2432 * Return: Remote device node associated with remote endpoint node linked
2433 * to @node. Use of_node_put() on it when done.
2434 */
2435struct device_node *of_graph_get_remote_port_parent(
2436 const struct device_node *node)
2437{
2438 struct device_node *np;
2439 unsigned int depth;
2440
2441 /* Get remote endpoint node. */
2442 np = of_parse_phandle(node, "remote-endpoint", 0);
2443
2444 /* Walk 3 levels up only if there is 'ports' node. */
2445 for (depth = 3; depth && np; depth--) {
2446 np = of_get_next_parent(np);
2447 if (depth == 2 && of_node_cmp(np->name, "ports"))
2448 break;
2449 }
2450 return np;
2451}
2452EXPORT_SYMBOL(of_graph_get_remote_port_parent);
2453
2454/**
2455 * of_graph_get_remote_port() - get remote port node
2456 * @node: pointer to a local endpoint device_node
2457 *
2458 * Return: Remote port node associated with remote endpoint node linked
2459 * to @node. Use of_node_put() on it when done.
2460 */
2461struct device_node *of_graph_get_remote_port(const struct device_node *node)
2462{
2463 struct device_node *np;
2464
2465 /* Get remote endpoint node. */
2466 np = of_parse_phandle(node, "remote-endpoint", 0);
2467 if (!np)
2468 return NULL;
2469 return of_get_next_parent(np);
2470}
2471EXPORT_SYMBOL(of_graph_get_remote_port);