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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// 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/bitmap.h>
20#include <linux/console.h>
21#include <linux/ctype.h>
22#include <linux/cpu.h>
23#include <linux/module.h>
24#include <linux/of.h>
25#include <linux/of_device.h>
26#include <linux/of_graph.h>
27#include <linux/spinlock.h>
28#include <linux/slab.h>
29#include <linux/string.h>
30#include <linux/proc_fs.h>
31
32#include "of_private.h"
33
34LIST_HEAD(aliases_lookup);
35
36struct device_node *of_root;
37EXPORT_SYMBOL(of_root);
38struct device_node *of_chosen;
39struct device_node *of_aliases;
40struct device_node *of_stdout;
41static const char *of_stdout_options;
42
43struct kset *of_kset;
44
45/*
46 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
47 * This mutex must be held whenever modifications are being made to the
48 * device tree. The of_{attach,detach}_node() and
49 * of_{add,remove,update}_property() helpers make sure this happens.
50 */
51DEFINE_MUTEX(of_mutex);
52
53/* use when traversing tree through the child, sibling,
54 * or parent members of struct device_node.
55 */
56DEFINE_RAW_SPINLOCK(devtree_lock);
57
58bool of_node_name_eq(const struct device_node *np, const char *name)
59{
60 const char *node_name;
61 size_t len;
62
63 if (!np)
64 return false;
65
66 node_name = kbasename(np->full_name);
67 len = strchrnul(node_name, '@') - node_name;
68
69 return (strlen(name) == len) && (strncmp(node_name, name, len) == 0);
70}
71EXPORT_SYMBOL(of_node_name_eq);
72
73bool of_node_name_prefix(const struct device_node *np, const char *prefix)
74{
75 if (!np)
76 return false;
77
78 return strncmp(kbasename(np->full_name), prefix, strlen(prefix)) == 0;
79}
80EXPORT_SYMBOL(of_node_name_prefix);
81
82static bool __of_node_is_type(const struct device_node *np, const char *type)
83{
84 const char *match = __of_get_property(np, "device_type", NULL);
85
86 return np && match && type && !strcmp(match, type);
87}
88
89int of_bus_n_addr_cells(struct device_node *np)
90{
91 u32 cells;
92
93 for (; np; np = np->parent)
94 if (!of_property_read_u32(np, "#address-cells", &cells))
95 return cells;
96
97 /* No #address-cells property for the root node */
98 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
99}
100
101int of_n_addr_cells(struct device_node *np)
102{
103 if (np->parent)
104 np = np->parent;
105
106 return of_bus_n_addr_cells(np);
107}
108EXPORT_SYMBOL(of_n_addr_cells);
109
110int of_bus_n_size_cells(struct device_node *np)
111{
112 u32 cells;
113
114 for (; np; np = np->parent)
115 if (!of_property_read_u32(np, "#size-cells", &cells))
116 return cells;
117
118 /* No #size-cells property for the root node */
119 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
120}
121
122int of_n_size_cells(struct device_node *np)
123{
124 if (np->parent)
125 np = np->parent;
126
127 return of_bus_n_size_cells(np);
128}
129EXPORT_SYMBOL(of_n_size_cells);
130
131#ifdef CONFIG_NUMA
132int __weak of_node_to_nid(struct device_node *np)
133{
134 return NUMA_NO_NODE;
135}
136#endif
137
138#define OF_PHANDLE_CACHE_BITS 7
139#define OF_PHANDLE_CACHE_SZ BIT(OF_PHANDLE_CACHE_BITS)
140
141static struct device_node *phandle_cache[OF_PHANDLE_CACHE_SZ];
142
143static u32 of_phandle_cache_hash(phandle handle)
144{
145 return hash_32(handle, OF_PHANDLE_CACHE_BITS);
146}
147
148/*
149 * Caller must hold devtree_lock.
150 */
151void __of_phandle_cache_inv_entry(phandle handle)
152{
153 u32 handle_hash;
154 struct device_node *np;
155
156 if (!handle)
157 return;
158
159 handle_hash = of_phandle_cache_hash(handle);
160
161 np = phandle_cache[handle_hash];
162 if (np && handle == np->phandle)
163 phandle_cache[handle_hash] = NULL;
164}
165
166void __init of_core_init(void)
167{
168 struct device_node *np;
169
170
171 /* Create the kset, and register existing nodes */
172 mutex_lock(&of_mutex);
173 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
174 if (!of_kset) {
175 mutex_unlock(&of_mutex);
176 pr_err("failed to register existing nodes\n");
177 return;
178 }
179 for_each_of_allnodes(np) {
180 __of_attach_node_sysfs(np);
181 if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)])
182 phandle_cache[of_phandle_cache_hash(np->phandle)] = np;
183 }
184 mutex_unlock(&of_mutex);
185
186 /* Symlink in /proc as required by userspace ABI */
187 if (of_root)
188 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
189}
190
191static struct property *__of_find_property(const struct device_node *np,
192 const char *name, int *lenp)
193{
194 struct property *pp;
195
196 if (!np)
197 return NULL;
198
199 for (pp = np->properties; pp; pp = pp->next) {
200 if (of_prop_cmp(pp->name, name) == 0) {
201 if (lenp)
202 *lenp = pp->length;
203 break;
204 }
205 }
206
207 return pp;
208}
209
210struct property *of_find_property(const struct device_node *np,
211 const char *name,
212 int *lenp)
213{
214 struct property *pp;
215 unsigned long flags;
216
217 raw_spin_lock_irqsave(&devtree_lock, flags);
218 pp = __of_find_property(np, name, lenp);
219 raw_spin_unlock_irqrestore(&devtree_lock, flags);
220
221 return pp;
222}
223EXPORT_SYMBOL(of_find_property);
224
225struct device_node *__of_find_all_nodes(struct device_node *prev)
226{
227 struct device_node *np;
228 if (!prev) {
229 np = of_root;
230 } else if (prev->child) {
231 np = prev->child;
232 } else {
233 /* Walk back up looking for a sibling, or the end of the structure */
234 np = prev;
235 while (np->parent && !np->sibling)
236 np = np->parent;
237 np = np->sibling; /* Might be null at the end of the tree */
238 }
239 return np;
240}
241
242/**
243 * of_find_all_nodes - Get next node in global list
244 * @prev: Previous node or NULL to start iteration
245 * of_node_put() will be called on it
246 *
247 * Returns a node pointer with refcount incremented, use
248 * of_node_put() on it when done.
249 */
250struct device_node *of_find_all_nodes(struct device_node *prev)
251{
252 struct device_node *np;
253 unsigned long flags;
254
255 raw_spin_lock_irqsave(&devtree_lock, flags);
256 np = __of_find_all_nodes(prev);
257 of_node_get(np);
258 of_node_put(prev);
259 raw_spin_unlock_irqrestore(&devtree_lock, flags);
260 return np;
261}
262EXPORT_SYMBOL(of_find_all_nodes);
263
264/*
265 * Find a property with a given name for a given node
266 * and return the value.
267 */
268const void *__of_get_property(const struct device_node *np,
269 const char *name, int *lenp)
270{
271 struct property *pp = __of_find_property(np, name, lenp);
272
273 return pp ? pp->value : NULL;
274}
275
276/*
277 * Find a property with a given name for a given node
278 * and return the value.
279 */
280const void *of_get_property(const struct device_node *np, const char *name,
281 int *lenp)
282{
283 struct property *pp = of_find_property(np, name, lenp);
284
285 return pp ? pp->value : NULL;
286}
287EXPORT_SYMBOL(of_get_property);
288
289/*
290 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
291 *
292 * @cpu: logical cpu index of a core/thread
293 * @phys_id: physical identifier of a core/thread
294 *
295 * CPU logical to physical index mapping is architecture specific.
296 * However this __weak function provides a default match of physical
297 * id to logical cpu index. phys_id provided here is usually values read
298 * from the device tree which must match the hardware internal registers.
299 *
300 * Returns true if the physical identifier and the logical cpu index
301 * correspond to the same core/thread, false otherwise.
302 */
303bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
304{
305 return (u32)phys_id == cpu;
306}
307
308/**
309 * Checks if the given "prop_name" property holds the physical id of the
310 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
311 * NULL, local thread number within the core is returned in it.
312 */
313static bool __of_find_n_match_cpu_property(struct device_node *cpun,
314 const char *prop_name, int cpu, unsigned int *thread)
315{
316 const __be32 *cell;
317 int ac, prop_len, tid;
318 u64 hwid;
319
320 ac = of_n_addr_cells(cpun);
321 cell = of_get_property(cpun, prop_name, &prop_len);
322 if (!cell && !ac && arch_match_cpu_phys_id(cpu, 0))
323 return true;
324 if (!cell || !ac)
325 return false;
326 prop_len /= sizeof(*cell) * ac;
327 for (tid = 0; tid < prop_len; tid++) {
328 hwid = of_read_number(cell, ac);
329 if (arch_match_cpu_phys_id(cpu, hwid)) {
330 if (thread)
331 *thread = tid;
332 return true;
333 }
334 cell += ac;
335 }
336 return false;
337}
338
339/*
340 * arch_find_n_match_cpu_physical_id - See if the given device node is
341 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
342 * else false. If 'thread' is non-NULL, the local thread number within the
343 * core is returned in it.
344 */
345bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
346 int cpu, unsigned int *thread)
347{
348 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
349 * for thread ids on PowerPC. If it doesn't exist fallback to
350 * standard "reg" property.
351 */
352 if (IS_ENABLED(CONFIG_PPC) &&
353 __of_find_n_match_cpu_property(cpun,
354 "ibm,ppc-interrupt-server#s",
355 cpu, thread))
356 return true;
357
358 return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
359}
360
361/**
362 * of_get_cpu_node - Get device node associated with the given logical CPU
363 *
364 * @cpu: CPU number(logical index) for which device node is required
365 * @thread: if not NULL, local thread number within the physical core is
366 * returned
367 *
368 * The main purpose of this function is to retrieve the device node for the
369 * given logical CPU index. It should be used to initialize the of_node in
370 * cpu device. Once of_node in cpu device is populated, all the further
371 * references can use that instead.
372 *
373 * CPU logical to physical index mapping is architecture specific and is built
374 * before booting secondary cores. This function uses arch_match_cpu_phys_id
375 * which can be overridden by architecture specific implementation.
376 *
377 * Returns a node pointer for the logical cpu with refcount incremented, use
378 * of_node_put() on it when done. Returns NULL if not found.
379 */
380struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
381{
382 struct device_node *cpun;
383
384 for_each_of_cpu_node(cpun) {
385 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
386 return cpun;
387 }
388 return NULL;
389}
390EXPORT_SYMBOL(of_get_cpu_node);
391
392/**
393 * of_cpu_node_to_id: Get the logical CPU number for a given device_node
394 *
395 * @cpu_node: Pointer to the device_node for CPU.
396 *
397 * Returns the logical CPU number of the given CPU device_node.
398 * Returns -ENODEV if the CPU is not found.
399 */
400int of_cpu_node_to_id(struct device_node *cpu_node)
401{
402 int cpu;
403 bool found = false;
404 struct device_node *np;
405
406 for_each_possible_cpu(cpu) {
407 np = of_cpu_device_node_get(cpu);
408 found = (cpu_node == np);
409 of_node_put(np);
410 if (found)
411 return cpu;
412 }
413
414 return -ENODEV;
415}
416EXPORT_SYMBOL(of_cpu_node_to_id);
417
418/**
419 * of_get_cpu_state_node - Get CPU's idle state node at the given index
420 *
421 * @cpu_node: The device node for the CPU
422 * @index: The index in the list of the idle states
423 *
424 * Two generic methods can be used to describe a CPU's idle states, either via
425 * a flattened description through the "cpu-idle-states" binding or via the
426 * hierarchical layout, using the "power-domains" and the "domain-idle-states"
427 * bindings. This function check for both and returns the idle state node for
428 * the requested index.
429 *
430 * In case an idle state node is found at @index, the refcount is incremented
431 * for it, so call of_node_put() on it when done. Returns NULL if not found.
432 */
433struct device_node *of_get_cpu_state_node(struct device_node *cpu_node,
434 int index)
435{
436 struct of_phandle_args args;
437 int err;
438
439 err = of_parse_phandle_with_args(cpu_node, "power-domains",
440 "#power-domain-cells", 0, &args);
441 if (!err) {
442 struct device_node *state_node =
443 of_parse_phandle(args.np, "domain-idle-states", index);
444
445 of_node_put(args.np);
446 if (state_node)
447 return state_node;
448 }
449
450 return of_parse_phandle(cpu_node, "cpu-idle-states", index);
451}
452EXPORT_SYMBOL(of_get_cpu_state_node);
453
454/**
455 * __of_device_is_compatible() - Check if the node matches given constraints
456 * @device: pointer to node
457 * @compat: required compatible string, NULL or "" for any match
458 * @type: required device_type value, NULL or "" for any match
459 * @name: required node name, NULL or "" for any match
460 *
461 * Checks if the given @compat, @type and @name strings match the
462 * properties of the given @device. A constraints can be skipped by
463 * passing NULL or an empty string as the constraint.
464 *
465 * Returns 0 for no match, and a positive integer on match. The return
466 * value is a relative score with larger values indicating better
467 * matches. The score is weighted for the most specific compatible value
468 * to get the highest score. Matching type is next, followed by matching
469 * name. Practically speaking, this results in the following priority
470 * order for matches:
471 *
472 * 1. specific compatible && type && name
473 * 2. specific compatible && type
474 * 3. specific compatible && name
475 * 4. specific compatible
476 * 5. general compatible && type && name
477 * 6. general compatible && type
478 * 7. general compatible && name
479 * 8. general compatible
480 * 9. type && name
481 * 10. type
482 * 11. name
483 */
484static int __of_device_is_compatible(const struct device_node *device,
485 const char *compat, const char *type, const char *name)
486{
487 struct property *prop;
488 const char *cp;
489 int index = 0, score = 0;
490
491 /* Compatible match has highest priority */
492 if (compat && compat[0]) {
493 prop = __of_find_property(device, "compatible", NULL);
494 for (cp = of_prop_next_string(prop, NULL); cp;
495 cp = of_prop_next_string(prop, cp), index++) {
496 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
497 score = INT_MAX/2 - (index << 2);
498 break;
499 }
500 }
501 if (!score)
502 return 0;
503 }
504
505 /* Matching type is better than matching name */
506 if (type && type[0]) {
507 if (!__of_node_is_type(device, type))
508 return 0;
509 score += 2;
510 }
511
512 /* Matching name is a bit better than not */
513 if (name && name[0]) {
514 if (!of_node_name_eq(device, name))
515 return 0;
516 score++;
517 }
518
519 return score;
520}
521
522/** Checks if the given "compat" string matches one of the strings in
523 * the device's "compatible" property
524 */
525int of_device_is_compatible(const struct device_node *device,
526 const char *compat)
527{
528 unsigned long flags;
529 int res;
530
531 raw_spin_lock_irqsave(&devtree_lock, flags);
532 res = __of_device_is_compatible(device, compat, NULL, NULL);
533 raw_spin_unlock_irqrestore(&devtree_lock, flags);
534 return res;
535}
536EXPORT_SYMBOL(of_device_is_compatible);
537
538/** Checks if the device is compatible with any of the entries in
539 * a NULL terminated array of strings. Returns the best match
540 * score or 0.
541 */
542int of_device_compatible_match(struct device_node *device,
543 const char *const *compat)
544{
545 unsigned int tmp, score = 0;
546
547 if (!compat)
548 return 0;
549
550 while (*compat) {
551 tmp = of_device_is_compatible(device, *compat);
552 if (tmp > score)
553 score = tmp;
554 compat++;
555 }
556
557 return score;
558}
559
560/**
561 * of_machine_is_compatible - Test root of device tree for a given compatible value
562 * @compat: compatible string to look for in root node's compatible property.
563 *
564 * Returns a positive integer if the root node has the given value in its
565 * compatible property.
566 */
567int of_machine_is_compatible(const char *compat)
568{
569 struct device_node *root;
570 int rc = 0;
571
572 root = of_find_node_by_path("/");
573 if (root) {
574 rc = of_device_is_compatible(root, compat);
575 of_node_put(root);
576 }
577 return rc;
578}
579EXPORT_SYMBOL(of_machine_is_compatible);
580
581/**
582 * __of_device_is_available - check if a device is available for use
583 *
584 * @device: Node to check for availability, with locks already held
585 *
586 * Returns true if the status property is absent or set to "okay" or "ok",
587 * false otherwise
588 */
589static bool __of_device_is_available(const struct device_node *device)
590{
591 const char *status;
592 int statlen;
593
594 if (!device)
595 return false;
596
597 status = __of_get_property(device, "status", &statlen);
598 if (status == NULL)
599 return true;
600
601 if (statlen > 0) {
602 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
603 return true;
604 }
605
606 return false;
607}
608
609/**
610 * of_device_is_available - check if a device is available for use
611 *
612 * @device: Node to check for availability
613 *
614 * Returns true if the status property is absent or set to "okay" or "ok",
615 * false otherwise
616 */
617bool of_device_is_available(const struct device_node *device)
618{
619 unsigned long flags;
620 bool res;
621
622 raw_spin_lock_irqsave(&devtree_lock, flags);
623 res = __of_device_is_available(device);
624 raw_spin_unlock_irqrestore(&devtree_lock, flags);
625 return res;
626
627}
628EXPORT_SYMBOL(of_device_is_available);
629
630/**
631 * of_device_is_big_endian - check if a device has BE registers
632 *
633 * @device: Node to check for endianness
634 *
635 * Returns true if the device has a "big-endian" property, or if the kernel
636 * was compiled for BE *and* the device has a "native-endian" property.
637 * Returns false otherwise.
638 *
639 * Callers would nominally use ioread32be/iowrite32be if
640 * of_device_is_big_endian() == true, or readl/writel otherwise.
641 */
642bool of_device_is_big_endian(const struct device_node *device)
643{
644 if (of_property_read_bool(device, "big-endian"))
645 return true;
646 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
647 of_property_read_bool(device, "native-endian"))
648 return true;
649 return false;
650}
651EXPORT_SYMBOL(of_device_is_big_endian);
652
653/**
654 * of_get_parent - Get a node's parent if any
655 * @node: Node to get parent
656 *
657 * Returns a node pointer with refcount incremented, use
658 * of_node_put() on it when done.
659 */
660struct device_node *of_get_parent(const struct device_node *node)
661{
662 struct device_node *np;
663 unsigned long flags;
664
665 if (!node)
666 return NULL;
667
668 raw_spin_lock_irqsave(&devtree_lock, flags);
669 np = of_node_get(node->parent);
670 raw_spin_unlock_irqrestore(&devtree_lock, flags);
671 return np;
672}
673EXPORT_SYMBOL(of_get_parent);
674
675/**
676 * of_get_next_parent - Iterate to a node's parent
677 * @node: Node to get parent of
678 *
679 * This is like of_get_parent() except that it drops the
680 * refcount on the passed node, making it suitable for iterating
681 * through a node's parents.
682 *
683 * Returns a node pointer with refcount incremented, use
684 * of_node_put() on it when done.
685 */
686struct device_node *of_get_next_parent(struct device_node *node)
687{
688 struct device_node *parent;
689 unsigned long flags;
690
691 if (!node)
692 return NULL;
693
694 raw_spin_lock_irqsave(&devtree_lock, flags);
695 parent = of_node_get(node->parent);
696 of_node_put(node);
697 raw_spin_unlock_irqrestore(&devtree_lock, flags);
698 return parent;
699}
700EXPORT_SYMBOL(of_get_next_parent);
701
702static struct device_node *__of_get_next_child(const struct device_node *node,
703 struct device_node *prev)
704{
705 struct device_node *next;
706
707 if (!node)
708 return NULL;
709
710 next = prev ? prev->sibling : node->child;
711 for (; next; next = next->sibling)
712 if (of_node_get(next))
713 break;
714 of_node_put(prev);
715 return next;
716}
717#define __for_each_child_of_node(parent, child) \
718 for (child = __of_get_next_child(parent, NULL); child != NULL; \
719 child = __of_get_next_child(parent, child))
720
721/**
722 * of_get_next_child - Iterate a node childs
723 * @node: parent node
724 * @prev: previous child of the parent node, or NULL to get first
725 *
726 * Returns a node pointer with refcount incremented, use of_node_put() on
727 * it when done. Returns NULL when prev is the last child. Decrements the
728 * refcount of prev.
729 */
730struct device_node *of_get_next_child(const struct device_node *node,
731 struct device_node *prev)
732{
733 struct device_node *next;
734 unsigned long flags;
735
736 raw_spin_lock_irqsave(&devtree_lock, flags);
737 next = __of_get_next_child(node, prev);
738 raw_spin_unlock_irqrestore(&devtree_lock, flags);
739 return next;
740}
741EXPORT_SYMBOL(of_get_next_child);
742
743/**
744 * of_get_next_available_child - Find the next available child node
745 * @node: parent node
746 * @prev: previous child of the parent node, or NULL to get first
747 *
748 * This function is like of_get_next_child(), except that it
749 * automatically skips any disabled nodes (i.e. status = "disabled").
750 */
751struct device_node *of_get_next_available_child(const struct device_node *node,
752 struct device_node *prev)
753{
754 struct device_node *next;
755 unsigned long flags;
756
757 if (!node)
758 return NULL;
759
760 raw_spin_lock_irqsave(&devtree_lock, flags);
761 next = prev ? prev->sibling : node->child;
762 for (; next; next = next->sibling) {
763 if (!__of_device_is_available(next))
764 continue;
765 if (of_node_get(next))
766 break;
767 }
768 of_node_put(prev);
769 raw_spin_unlock_irqrestore(&devtree_lock, flags);
770 return next;
771}
772EXPORT_SYMBOL(of_get_next_available_child);
773
774/**
775 * of_get_next_cpu_node - Iterate on cpu nodes
776 * @prev: previous child of the /cpus node, or NULL to get first
777 *
778 * Returns a cpu node pointer with refcount incremented, use of_node_put()
779 * on it when done. Returns NULL when prev is the last child. Decrements
780 * the refcount of prev.
781 */
782struct device_node *of_get_next_cpu_node(struct device_node *prev)
783{
784 struct device_node *next = NULL;
785 unsigned long flags;
786 struct device_node *node;
787
788 if (!prev)
789 node = of_find_node_by_path("/cpus");
790
791 raw_spin_lock_irqsave(&devtree_lock, flags);
792 if (prev)
793 next = prev->sibling;
794 else if (node) {
795 next = node->child;
796 of_node_put(node);
797 }
798 for (; next; next = next->sibling) {
799 if (!(of_node_name_eq(next, "cpu") ||
800 __of_node_is_type(next, "cpu")))
801 continue;
802 if (of_node_get(next))
803 break;
804 }
805 of_node_put(prev);
806 raw_spin_unlock_irqrestore(&devtree_lock, flags);
807 return next;
808}
809EXPORT_SYMBOL(of_get_next_cpu_node);
810
811/**
812 * of_get_compatible_child - Find compatible child node
813 * @parent: parent node
814 * @compatible: compatible string
815 *
816 * Lookup child node whose compatible property contains the given compatible
817 * string.
818 *
819 * Returns a node pointer with refcount incremented, use of_node_put() on it
820 * when done; or NULL if not found.
821 */
822struct device_node *of_get_compatible_child(const struct device_node *parent,
823 const char *compatible)
824{
825 struct device_node *child;
826
827 for_each_child_of_node(parent, child) {
828 if (of_device_is_compatible(child, compatible))
829 break;
830 }
831
832 return child;
833}
834EXPORT_SYMBOL(of_get_compatible_child);
835
836/**
837 * of_get_child_by_name - Find the child node by name for a given parent
838 * @node: parent node
839 * @name: child name to look for.
840 *
841 * This function looks for child node for given matching name
842 *
843 * Returns a node pointer if found, with refcount incremented, use
844 * of_node_put() on it when done.
845 * Returns NULL if node is not found.
846 */
847struct device_node *of_get_child_by_name(const struct device_node *node,
848 const char *name)
849{
850 struct device_node *child;
851
852 for_each_child_of_node(node, child)
853 if (of_node_name_eq(child, name))
854 break;
855 return child;
856}
857EXPORT_SYMBOL(of_get_child_by_name);
858
859struct device_node *__of_find_node_by_path(struct device_node *parent,
860 const char *path)
861{
862 struct device_node *child;
863 int len;
864
865 len = strcspn(path, "/:");
866 if (!len)
867 return NULL;
868
869 __for_each_child_of_node(parent, child) {
870 const char *name = kbasename(child->full_name);
871 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
872 return child;
873 }
874 return NULL;
875}
876
877struct device_node *__of_find_node_by_full_path(struct device_node *node,
878 const char *path)
879{
880 const char *separator = strchr(path, ':');
881
882 while (node && *path == '/') {
883 struct device_node *tmp = node;
884
885 path++; /* Increment past '/' delimiter */
886 node = __of_find_node_by_path(node, path);
887 of_node_put(tmp);
888 path = strchrnul(path, '/');
889 if (separator && separator < path)
890 break;
891 }
892 return node;
893}
894
895/**
896 * of_find_node_opts_by_path - Find a node matching a full OF path
897 * @path: Either the full path to match, or if the path does not
898 * start with '/', the name of a property of the /aliases
899 * node (an alias). In the case of an alias, the node
900 * matching the alias' value will be returned.
901 * @opts: Address of a pointer into which to store the start of
902 * an options string appended to the end of the path with
903 * a ':' separator.
904 *
905 * Valid paths:
906 * /foo/bar Full path
907 * foo Valid alias
908 * foo/bar Valid alias + relative path
909 *
910 * Returns a node pointer with refcount incremented, use
911 * of_node_put() on it when done.
912 */
913struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
914{
915 struct device_node *np = NULL;
916 struct property *pp;
917 unsigned long flags;
918 const char *separator = strchr(path, ':');
919
920 if (opts)
921 *opts = separator ? separator + 1 : NULL;
922
923 if (strcmp(path, "/") == 0)
924 return of_node_get(of_root);
925
926 /* The path could begin with an alias */
927 if (*path != '/') {
928 int len;
929 const char *p = separator;
930
931 if (!p)
932 p = strchrnul(path, '/');
933 len = p - path;
934
935 /* of_aliases must not be NULL */
936 if (!of_aliases)
937 return NULL;
938
939 for_each_property_of_node(of_aliases, pp) {
940 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
941 np = of_find_node_by_path(pp->value);
942 break;
943 }
944 }
945 if (!np)
946 return NULL;
947 path = p;
948 }
949
950 /* Step down the tree matching path components */
951 raw_spin_lock_irqsave(&devtree_lock, flags);
952 if (!np)
953 np = of_node_get(of_root);
954 np = __of_find_node_by_full_path(np, path);
955 raw_spin_unlock_irqrestore(&devtree_lock, flags);
956 return np;
957}
958EXPORT_SYMBOL(of_find_node_opts_by_path);
959
960/**
961 * of_find_node_by_name - Find a node by its "name" property
962 * @from: The node to start searching from or NULL; the node
963 * you pass will not be searched, only the next one
964 * will. Typically, you pass what the previous call
965 * returned. of_node_put() will be called on @from.
966 * @name: The name string to match against
967 *
968 * Returns a node pointer with refcount incremented, use
969 * of_node_put() on it when done.
970 */
971struct device_node *of_find_node_by_name(struct device_node *from,
972 const char *name)
973{
974 struct device_node *np;
975 unsigned long flags;
976
977 raw_spin_lock_irqsave(&devtree_lock, flags);
978 for_each_of_allnodes_from(from, np)
979 if (of_node_name_eq(np, name) && of_node_get(np))
980 break;
981 of_node_put(from);
982 raw_spin_unlock_irqrestore(&devtree_lock, flags);
983 return np;
984}
985EXPORT_SYMBOL(of_find_node_by_name);
986
987/**
988 * of_find_node_by_type - Find a node by its "device_type" property
989 * @from: The node to start searching from, or NULL to start searching
990 * the entire device tree. The node you pass will not be
991 * searched, only the next one will; typically, you pass
992 * what the previous call returned. of_node_put() will be
993 * called on from for you.
994 * @type: The type string to match against
995 *
996 * Returns a node pointer with refcount incremented, use
997 * of_node_put() on it when done.
998 */
999struct device_node *of_find_node_by_type(struct device_node *from,
1000 const char *type)
1001{
1002 struct device_node *np;
1003 unsigned long flags;
1004
1005 raw_spin_lock_irqsave(&devtree_lock, flags);
1006 for_each_of_allnodes_from(from, np)
1007 if (__of_node_is_type(np, type) && of_node_get(np))
1008 break;
1009 of_node_put(from);
1010 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1011 return np;
1012}
1013EXPORT_SYMBOL(of_find_node_by_type);
1014
1015/**
1016 * of_find_compatible_node - Find a node based on type and one of the
1017 * tokens in its "compatible" property
1018 * @from: The node to start searching from or NULL, the node
1019 * you pass will not be searched, only the next one
1020 * will; typically, you pass what the previous call
1021 * returned. of_node_put() will be called on it
1022 * @type: The type string to match "device_type" or NULL to ignore
1023 * @compatible: The string to match to one of the tokens in the device
1024 * "compatible" list.
1025 *
1026 * Returns a node pointer with refcount incremented, use
1027 * of_node_put() on it when done.
1028 */
1029struct device_node *of_find_compatible_node(struct device_node *from,
1030 const char *type, const char *compatible)
1031{
1032 struct device_node *np;
1033 unsigned long flags;
1034
1035 raw_spin_lock_irqsave(&devtree_lock, flags);
1036 for_each_of_allnodes_from(from, np)
1037 if (__of_device_is_compatible(np, compatible, type, NULL) &&
1038 of_node_get(np))
1039 break;
1040 of_node_put(from);
1041 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1042 return np;
1043}
1044EXPORT_SYMBOL(of_find_compatible_node);
1045
1046/**
1047 * of_find_node_with_property - Find a node which has a property with
1048 * the given name.
1049 * @from: The node to start searching from or NULL, the node
1050 * you pass will not be searched, only the next one
1051 * will; typically, you pass what the previous call
1052 * returned. of_node_put() will be called on it
1053 * @prop_name: The name of the property to look for.
1054 *
1055 * Returns a node pointer with refcount incremented, use
1056 * of_node_put() on it when done.
1057 */
1058struct device_node *of_find_node_with_property(struct device_node *from,
1059 const char *prop_name)
1060{
1061 struct device_node *np;
1062 struct property *pp;
1063 unsigned long flags;
1064
1065 raw_spin_lock_irqsave(&devtree_lock, flags);
1066 for_each_of_allnodes_from(from, np) {
1067 for (pp = np->properties; pp; pp = pp->next) {
1068 if (of_prop_cmp(pp->name, prop_name) == 0) {
1069 of_node_get(np);
1070 goto out;
1071 }
1072 }
1073 }
1074out:
1075 of_node_put(from);
1076 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1077 return np;
1078}
1079EXPORT_SYMBOL(of_find_node_with_property);
1080
1081static
1082const struct of_device_id *__of_match_node(const struct of_device_id *matches,
1083 const struct device_node *node)
1084{
1085 const struct of_device_id *best_match = NULL;
1086 int score, best_score = 0;
1087
1088 if (!matches)
1089 return NULL;
1090
1091 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
1092 score = __of_device_is_compatible(node, matches->compatible,
1093 matches->type, matches->name);
1094 if (score > best_score) {
1095 best_match = matches;
1096 best_score = score;
1097 }
1098 }
1099
1100 return best_match;
1101}
1102
1103/**
1104 * of_match_node - Tell if a device_node has a matching of_match structure
1105 * @matches: array of of device match structures to search in
1106 * @node: the of device structure to match against
1107 *
1108 * Low level utility function used by device matching.
1109 */
1110const struct of_device_id *of_match_node(const struct of_device_id *matches,
1111 const struct device_node *node)
1112{
1113 const struct of_device_id *match;
1114 unsigned long flags;
1115
1116 raw_spin_lock_irqsave(&devtree_lock, flags);
1117 match = __of_match_node(matches, node);
1118 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1119 return match;
1120}
1121EXPORT_SYMBOL(of_match_node);
1122
1123/**
1124 * of_find_matching_node_and_match - Find a node based on an of_device_id
1125 * match table.
1126 * @from: The node to start searching from or NULL, the node
1127 * you pass will not be searched, only the next one
1128 * will; typically, you pass what the previous call
1129 * returned. of_node_put() will be called on it
1130 * @matches: array of of device match structures to search in
1131 * @match Updated to point at the matches entry which matched
1132 *
1133 * Returns a node pointer with refcount incremented, use
1134 * of_node_put() on it when done.
1135 */
1136struct device_node *of_find_matching_node_and_match(struct device_node *from,
1137 const struct of_device_id *matches,
1138 const struct of_device_id **match)
1139{
1140 struct device_node *np;
1141 const struct of_device_id *m;
1142 unsigned long flags;
1143
1144 if (match)
1145 *match = NULL;
1146
1147 raw_spin_lock_irqsave(&devtree_lock, flags);
1148 for_each_of_allnodes_from(from, np) {
1149 m = __of_match_node(matches, np);
1150 if (m && of_node_get(np)) {
1151 if (match)
1152 *match = m;
1153 break;
1154 }
1155 }
1156 of_node_put(from);
1157 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1158 return np;
1159}
1160EXPORT_SYMBOL(of_find_matching_node_and_match);
1161
1162/**
1163 * of_modalias_node - Lookup appropriate modalias for a device node
1164 * @node: pointer to a device tree node
1165 * @modalias: Pointer to buffer that modalias value will be copied into
1166 * @len: Length of modalias value
1167 *
1168 * Based on the value of the compatible property, this routine will attempt
1169 * to choose an appropriate modalias value for a particular device tree node.
1170 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1171 * from the first entry in the compatible list property.
1172 *
1173 * This routine returns 0 on success, <0 on failure.
1174 */
1175int of_modalias_node(struct device_node *node, char *modalias, int len)
1176{
1177 const char *compatible, *p;
1178 int cplen;
1179
1180 compatible = of_get_property(node, "compatible", &cplen);
1181 if (!compatible || strlen(compatible) > cplen)
1182 return -ENODEV;
1183 p = strchr(compatible, ',');
1184 strlcpy(modalias, p ? p + 1 : compatible, len);
1185 return 0;
1186}
1187EXPORT_SYMBOL_GPL(of_modalias_node);
1188
1189/**
1190 * of_find_node_by_phandle - Find a node given a phandle
1191 * @handle: phandle of the node to find
1192 *
1193 * Returns a node pointer with refcount incremented, use
1194 * of_node_put() on it when done.
1195 */
1196struct device_node *of_find_node_by_phandle(phandle handle)
1197{
1198 struct device_node *np = NULL;
1199 unsigned long flags;
1200 u32 handle_hash;
1201
1202 if (!handle)
1203 return NULL;
1204
1205 handle_hash = of_phandle_cache_hash(handle);
1206
1207 raw_spin_lock_irqsave(&devtree_lock, flags);
1208
1209 if (phandle_cache[handle_hash] &&
1210 handle == phandle_cache[handle_hash]->phandle)
1211 np = phandle_cache[handle_hash];
1212
1213 if (!np) {
1214 for_each_of_allnodes(np)
1215 if (np->phandle == handle &&
1216 !of_node_check_flag(np, OF_DETACHED)) {
1217 phandle_cache[handle_hash] = np;
1218 break;
1219 }
1220 }
1221
1222 of_node_get(np);
1223 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1224 return np;
1225}
1226EXPORT_SYMBOL(of_find_node_by_phandle);
1227
1228void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1229{
1230 int i;
1231 printk("%s %pOF", msg, args->np);
1232 for (i = 0; i < args->args_count; i++) {
1233 const char delim = i ? ',' : ':';
1234
1235 pr_cont("%c%08x", delim, args->args[i]);
1236 }
1237 pr_cont("\n");
1238}
1239
1240int of_phandle_iterator_init(struct of_phandle_iterator *it,
1241 const struct device_node *np,
1242 const char *list_name,
1243 const char *cells_name,
1244 int cell_count)
1245{
1246 const __be32 *list;
1247 int size;
1248
1249 memset(it, 0, sizeof(*it));
1250
1251 /*
1252 * one of cell_count or cells_name must be provided to determine the
1253 * argument length.
1254 */
1255 if (cell_count < 0 && !cells_name)
1256 return -EINVAL;
1257
1258 list = of_get_property(np, list_name, &size);
1259 if (!list)
1260 return -ENOENT;
1261
1262 it->cells_name = cells_name;
1263 it->cell_count = cell_count;
1264 it->parent = np;
1265 it->list_end = list + size / sizeof(*list);
1266 it->phandle_end = list;
1267 it->cur = list;
1268
1269 return 0;
1270}
1271EXPORT_SYMBOL_GPL(of_phandle_iterator_init);
1272
1273int of_phandle_iterator_next(struct of_phandle_iterator *it)
1274{
1275 uint32_t count = 0;
1276
1277 if (it->node) {
1278 of_node_put(it->node);
1279 it->node = NULL;
1280 }
1281
1282 if (!it->cur || it->phandle_end >= it->list_end)
1283 return -ENOENT;
1284
1285 it->cur = it->phandle_end;
1286
1287 /* If phandle is 0, then it is an empty entry with no arguments. */
1288 it->phandle = be32_to_cpup(it->cur++);
1289
1290 if (it->phandle) {
1291
1292 /*
1293 * Find the provider node and parse the #*-cells property to
1294 * determine the argument length.
1295 */
1296 it->node = of_find_node_by_phandle(it->phandle);
1297
1298 if (it->cells_name) {
1299 if (!it->node) {
1300 pr_err("%pOF: could not find phandle\n",
1301 it->parent);
1302 goto err;
1303 }
1304
1305 if (of_property_read_u32(it->node, it->cells_name,
1306 &count)) {
1307 /*
1308 * If both cell_count and cells_name is given,
1309 * fall back to cell_count in absence
1310 * of the cells_name property
1311 */
1312 if (it->cell_count >= 0) {
1313 count = it->cell_count;
1314 } else {
1315 pr_err("%pOF: could not get %s for %pOF\n",
1316 it->parent,
1317 it->cells_name,
1318 it->node);
1319 goto err;
1320 }
1321 }
1322 } else {
1323 count = it->cell_count;
1324 }
1325
1326 /*
1327 * Make sure that the arguments actually fit in the remaining
1328 * property data length
1329 */
1330 if (it->cur + count > it->list_end) {
1331 pr_err("%pOF: %s = %d found %d\n",
1332 it->parent, it->cells_name,
1333 count, it->cell_count);
1334 goto err;
1335 }
1336 }
1337
1338 it->phandle_end = it->cur + count;
1339 it->cur_count = count;
1340
1341 return 0;
1342
1343err:
1344 if (it->node) {
1345 of_node_put(it->node);
1346 it->node = NULL;
1347 }
1348
1349 return -EINVAL;
1350}
1351EXPORT_SYMBOL_GPL(of_phandle_iterator_next);
1352
1353int of_phandle_iterator_args(struct of_phandle_iterator *it,
1354 uint32_t *args,
1355 int size)
1356{
1357 int i, count;
1358
1359 count = it->cur_count;
1360
1361 if (WARN_ON(size < count))
1362 count = size;
1363
1364 for (i = 0; i < count; i++)
1365 args[i] = be32_to_cpup(it->cur++);
1366
1367 return count;
1368}
1369
1370static int __of_parse_phandle_with_args(const struct device_node *np,
1371 const char *list_name,
1372 const char *cells_name,
1373 int cell_count, int index,
1374 struct of_phandle_args *out_args)
1375{
1376 struct of_phandle_iterator it;
1377 int rc, cur_index = 0;
1378
1379 /* Loop over the phandles until all the requested entry is found */
1380 of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
1381 /*
1382 * All of the error cases bail out of the loop, so at
1383 * this point, the parsing is successful. If the requested
1384 * index matches, then fill the out_args structure and return,
1385 * or return -ENOENT for an empty entry.
1386 */
1387 rc = -ENOENT;
1388 if (cur_index == index) {
1389 if (!it.phandle)
1390 goto err;
1391
1392 if (out_args) {
1393 int c;
1394
1395 c = of_phandle_iterator_args(&it,
1396 out_args->args,
1397 MAX_PHANDLE_ARGS);
1398 out_args->np = it.node;
1399 out_args->args_count = c;
1400 } else {
1401 of_node_put(it.node);
1402 }
1403
1404 /* Found it! return success */
1405 return 0;
1406 }
1407
1408 cur_index++;
1409 }
1410
1411 /*
1412 * Unlock node before returning result; will be one of:
1413 * -ENOENT : index is for empty phandle
1414 * -EINVAL : parsing error on data
1415 */
1416
1417 err:
1418 of_node_put(it.node);
1419 return rc;
1420}
1421
1422/**
1423 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1424 * @np: Pointer to device node holding phandle property
1425 * @phandle_name: Name of property holding a phandle value
1426 * @index: For properties holding a table of phandles, this is the index into
1427 * the table
1428 *
1429 * Returns the device_node pointer with refcount incremented. Use
1430 * of_node_put() on it when done.
1431 */
1432struct device_node *of_parse_phandle(const struct device_node *np,
1433 const char *phandle_name, int index)
1434{
1435 struct of_phandle_args args;
1436
1437 if (index < 0)
1438 return NULL;
1439
1440 if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1441 index, &args))
1442 return NULL;
1443
1444 return args.np;
1445}
1446EXPORT_SYMBOL(of_parse_phandle);
1447
1448/**
1449 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1450 * @np: pointer to a device tree node containing a list
1451 * @list_name: property name that contains a list
1452 * @cells_name: property name that specifies phandles' arguments count
1453 * @index: index of a phandle to parse out
1454 * @out_args: optional pointer to output arguments structure (will be filled)
1455 *
1456 * This function is useful to parse lists of phandles and their arguments.
1457 * Returns 0 on success and fills out_args, on error returns appropriate
1458 * errno value.
1459 *
1460 * Caller is responsible to call of_node_put() on the returned out_args->np
1461 * pointer.
1462 *
1463 * Example:
1464 *
1465 * phandle1: node1 {
1466 * #list-cells = <2>;
1467 * }
1468 *
1469 * phandle2: node2 {
1470 * #list-cells = <1>;
1471 * }
1472 *
1473 * node3 {
1474 * list = <&phandle1 1 2 &phandle2 3>;
1475 * }
1476 *
1477 * To get a device_node of the `node2' node you may call this:
1478 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1479 */
1480int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1481 const char *cells_name, int index,
1482 struct of_phandle_args *out_args)
1483{
1484 int cell_count = -1;
1485
1486 if (index < 0)
1487 return -EINVAL;
1488
1489 /* If cells_name is NULL we assume a cell count of 0 */
1490 if (!cells_name)
1491 cell_count = 0;
1492
1493 return __of_parse_phandle_with_args(np, list_name, cells_name,
1494 cell_count, index, out_args);
1495}
1496EXPORT_SYMBOL(of_parse_phandle_with_args);
1497
1498/**
1499 * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it
1500 * @np: pointer to a device tree node containing a list
1501 * @list_name: property name that contains a list
1502 * @stem_name: stem of property names that specify phandles' arguments count
1503 * @index: index of a phandle to parse out
1504 * @out_args: optional pointer to output arguments structure (will be filled)
1505 *
1506 * This function is useful to parse lists of phandles and their arguments.
1507 * Returns 0 on success and fills out_args, on error returns appropriate errno
1508 * value. The difference between this function and of_parse_phandle_with_args()
1509 * is that this API remaps a phandle if the node the phandle points to has
1510 * a <@stem_name>-map property.
1511 *
1512 * Caller is responsible to call of_node_put() on the returned out_args->np
1513 * pointer.
1514 *
1515 * Example:
1516 *
1517 * phandle1: node1 {
1518 * #list-cells = <2>;
1519 * }
1520 *
1521 * phandle2: node2 {
1522 * #list-cells = <1>;
1523 * }
1524 *
1525 * phandle3: node3 {
1526 * #list-cells = <1>;
1527 * list-map = <0 &phandle2 3>,
1528 * <1 &phandle2 2>,
1529 * <2 &phandle1 5 1>;
1530 * list-map-mask = <0x3>;
1531 * };
1532 *
1533 * node4 {
1534 * list = <&phandle1 1 2 &phandle3 0>;
1535 * }
1536 *
1537 * To get a device_node of the `node2' node you may call this:
1538 * of_parse_phandle_with_args(node4, "list", "list", 1, &args);
1539 */
1540int of_parse_phandle_with_args_map(const struct device_node *np,
1541 const char *list_name,
1542 const char *stem_name,
1543 int index, struct of_phandle_args *out_args)
1544{
1545 char *cells_name, *map_name = NULL, *mask_name = NULL;
1546 char *pass_name = NULL;
1547 struct device_node *cur, *new = NULL;
1548 const __be32 *map, *mask, *pass;
1549 static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 };
1550 static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = 0 };
1551 __be32 initial_match_array[MAX_PHANDLE_ARGS];
1552 const __be32 *match_array = initial_match_array;
1553 int i, ret, map_len, match;
1554 u32 list_size, new_size;
1555
1556 if (index < 0)
1557 return -EINVAL;
1558
1559 cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
1560 if (!cells_name)
1561 return -ENOMEM;
1562
1563 ret = -ENOMEM;
1564 map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name);
1565 if (!map_name)
1566 goto free;
1567
1568 mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
1569 if (!mask_name)
1570 goto free;
1571
1572 pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
1573 if (!pass_name)
1574 goto free;
1575
1576 ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
1577 out_args);
1578 if (ret)
1579 goto free;
1580
1581 /* Get the #<list>-cells property */
1582 cur = out_args->np;
1583 ret = of_property_read_u32(cur, cells_name, &list_size);
1584 if (ret < 0)
1585 goto put;
1586
1587 /* Precalculate the match array - this simplifies match loop */
1588 for (i = 0; i < list_size; i++)
1589 initial_match_array[i] = cpu_to_be32(out_args->args[i]);
1590
1591 ret = -EINVAL;
1592 while (cur) {
1593 /* Get the <list>-map property */
1594 map = of_get_property(cur, map_name, &map_len);
1595 if (!map) {
1596 ret = 0;
1597 goto free;
1598 }
1599 map_len /= sizeof(u32);
1600
1601 /* Get the <list>-map-mask property (optional) */
1602 mask = of_get_property(cur, mask_name, NULL);
1603 if (!mask)
1604 mask = dummy_mask;
1605 /* Iterate through <list>-map property */
1606 match = 0;
1607 while (map_len > (list_size + 1) && !match) {
1608 /* Compare specifiers */
1609 match = 1;
1610 for (i = 0; i < list_size; i++, map_len--)
1611 match &= !((match_array[i] ^ *map++) & mask[i]);
1612
1613 of_node_put(new);
1614 new = of_find_node_by_phandle(be32_to_cpup(map));
1615 map++;
1616 map_len--;
1617
1618 /* Check if not found */
1619 if (!new)
1620 goto put;
1621
1622 if (!of_device_is_available(new))
1623 match = 0;
1624
1625 ret = of_property_read_u32(new, cells_name, &new_size);
1626 if (ret)
1627 goto put;
1628
1629 /* Check for malformed properties */
1630 if (WARN_ON(new_size > MAX_PHANDLE_ARGS))
1631 goto put;
1632 if (map_len < new_size)
1633 goto put;
1634
1635 /* Move forward by new node's #<list>-cells amount */
1636 map += new_size;
1637 map_len -= new_size;
1638 }
1639 if (!match)
1640 goto put;
1641
1642 /* Get the <list>-map-pass-thru property (optional) */
1643 pass = of_get_property(cur, pass_name, NULL);
1644 if (!pass)
1645 pass = dummy_pass;
1646
1647 /*
1648 * Successfully parsed a <list>-map translation; copy new
1649 * specifier into the out_args structure, keeping the
1650 * bits specified in <list>-map-pass-thru.
1651 */
1652 match_array = map - new_size;
1653 for (i = 0; i < new_size; i++) {
1654 __be32 val = *(map - new_size + i);
1655
1656 if (i < list_size) {
1657 val &= ~pass[i];
1658 val |= cpu_to_be32(out_args->args[i]) & pass[i];
1659 }
1660
1661 out_args->args[i] = be32_to_cpu(val);
1662 }
1663 out_args->args_count = list_size = new_size;
1664 /* Iterate again with new provider */
1665 out_args->np = new;
1666 of_node_put(cur);
1667 cur = new;
1668 }
1669put:
1670 of_node_put(cur);
1671 of_node_put(new);
1672free:
1673 kfree(mask_name);
1674 kfree(map_name);
1675 kfree(cells_name);
1676 kfree(pass_name);
1677
1678 return ret;
1679}
1680EXPORT_SYMBOL(of_parse_phandle_with_args_map);
1681
1682/**
1683 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1684 * @np: pointer to a device tree node containing a list
1685 * @list_name: property name that contains a list
1686 * @cell_count: number of argument cells following the phandle
1687 * @index: index of a phandle to parse out
1688 * @out_args: optional pointer to output arguments structure (will be filled)
1689 *
1690 * This function is useful to parse lists of phandles and their arguments.
1691 * Returns 0 on success and fills out_args, on error returns appropriate
1692 * errno value.
1693 *
1694 * Caller is responsible to call of_node_put() on the returned out_args->np
1695 * pointer.
1696 *
1697 * Example:
1698 *
1699 * phandle1: node1 {
1700 * }
1701 *
1702 * phandle2: node2 {
1703 * }
1704 *
1705 * node3 {
1706 * list = <&phandle1 0 2 &phandle2 2 3>;
1707 * }
1708 *
1709 * To get a device_node of the `node2' node you may call this:
1710 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1711 */
1712int of_parse_phandle_with_fixed_args(const struct device_node *np,
1713 const char *list_name, int cell_count,
1714 int index, struct of_phandle_args *out_args)
1715{
1716 if (index < 0)
1717 return -EINVAL;
1718 return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1719 index, out_args);
1720}
1721EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1722
1723/**
1724 * of_count_phandle_with_args() - Find the number of phandles references in a property
1725 * @np: pointer to a device tree node containing a list
1726 * @list_name: property name that contains a list
1727 * @cells_name: property name that specifies phandles' arguments count
1728 *
1729 * Returns the number of phandle + argument tuples within a property. It
1730 * is a typical pattern to encode a list of phandle and variable
1731 * arguments into a single property. The number of arguments is encoded
1732 * by a property in the phandle-target node. For example, a gpios
1733 * property would contain a list of GPIO specifies consisting of a
1734 * phandle and 1 or more arguments. The number of arguments are
1735 * determined by the #gpio-cells property in the node pointed to by the
1736 * phandle.
1737 */
1738int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1739 const char *cells_name)
1740{
1741 struct of_phandle_iterator it;
1742 int rc, cur_index = 0;
1743
1744 /*
1745 * If cells_name is NULL we assume a cell count of 0. This makes
1746 * counting the phandles trivial as each 32bit word in the list is a
1747 * phandle and no arguments are to consider. So we don't iterate through
1748 * the list but just use the length to determine the phandle count.
1749 */
1750 if (!cells_name) {
1751 const __be32 *list;
1752 int size;
1753
1754 list = of_get_property(np, list_name, &size);
1755 if (!list)
1756 return -ENOENT;
1757
1758 return size / sizeof(*list);
1759 }
1760
1761 rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
1762 if (rc)
1763 return rc;
1764
1765 while ((rc = of_phandle_iterator_next(&it)) == 0)
1766 cur_index += 1;
1767
1768 if (rc != -ENOENT)
1769 return rc;
1770
1771 return cur_index;
1772}
1773EXPORT_SYMBOL(of_count_phandle_with_args);
1774
1775/**
1776 * __of_add_property - Add a property to a node without lock operations
1777 */
1778int __of_add_property(struct device_node *np, struct property *prop)
1779{
1780 struct property **next;
1781
1782 prop->next = NULL;
1783 next = &np->properties;
1784 while (*next) {
1785 if (strcmp(prop->name, (*next)->name) == 0)
1786 /* duplicate ! don't insert it */
1787 return -EEXIST;
1788
1789 next = &(*next)->next;
1790 }
1791 *next = prop;
1792
1793 return 0;
1794}
1795
1796/**
1797 * of_add_property - Add a property to a node
1798 */
1799int of_add_property(struct device_node *np, struct property *prop)
1800{
1801 unsigned long flags;
1802 int rc;
1803
1804 mutex_lock(&of_mutex);
1805
1806 raw_spin_lock_irqsave(&devtree_lock, flags);
1807 rc = __of_add_property(np, prop);
1808 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1809
1810 if (!rc)
1811 __of_add_property_sysfs(np, prop);
1812
1813 mutex_unlock(&of_mutex);
1814
1815 if (!rc)
1816 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1817
1818 return rc;
1819}
1820
1821int __of_remove_property(struct device_node *np, struct property *prop)
1822{
1823 struct property **next;
1824
1825 for (next = &np->properties; *next; next = &(*next)->next) {
1826 if (*next == prop)
1827 break;
1828 }
1829 if (*next == NULL)
1830 return -ENODEV;
1831
1832 /* found the node */
1833 *next = prop->next;
1834 prop->next = np->deadprops;
1835 np->deadprops = prop;
1836
1837 return 0;
1838}
1839
1840/**
1841 * of_remove_property - Remove a property from a node.
1842 *
1843 * Note that we don't actually remove it, since we have given out
1844 * who-knows-how-many pointers to the data using get-property.
1845 * Instead we just move the property to the "dead properties"
1846 * list, so it won't be found any more.
1847 */
1848int of_remove_property(struct device_node *np, struct property *prop)
1849{
1850 unsigned long flags;
1851 int rc;
1852
1853 if (!prop)
1854 return -ENODEV;
1855
1856 mutex_lock(&of_mutex);
1857
1858 raw_spin_lock_irqsave(&devtree_lock, flags);
1859 rc = __of_remove_property(np, prop);
1860 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1861
1862 if (!rc)
1863 __of_remove_property_sysfs(np, prop);
1864
1865 mutex_unlock(&of_mutex);
1866
1867 if (!rc)
1868 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1869
1870 return rc;
1871}
1872
1873int __of_update_property(struct device_node *np, struct property *newprop,
1874 struct property **oldpropp)
1875{
1876 struct property **next, *oldprop;
1877
1878 for (next = &np->properties; *next; next = &(*next)->next) {
1879 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1880 break;
1881 }
1882 *oldpropp = oldprop = *next;
1883
1884 if (oldprop) {
1885 /* replace the node */
1886 newprop->next = oldprop->next;
1887 *next = newprop;
1888 oldprop->next = np->deadprops;
1889 np->deadprops = oldprop;
1890 } else {
1891 /* new node */
1892 newprop->next = NULL;
1893 *next = newprop;
1894 }
1895
1896 return 0;
1897}
1898
1899/*
1900 * of_update_property - Update a property in a node, if the property does
1901 * not exist, add it.
1902 *
1903 * Note that we don't actually remove it, since we have given out
1904 * who-knows-how-many pointers to the data using get-property.
1905 * Instead we just move the property to the "dead properties" list,
1906 * and add the new property to the property list
1907 */
1908int of_update_property(struct device_node *np, struct property *newprop)
1909{
1910 struct property *oldprop;
1911 unsigned long flags;
1912 int rc;
1913
1914 if (!newprop->name)
1915 return -EINVAL;
1916
1917 mutex_lock(&of_mutex);
1918
1919 raw_spin_lock_irqsave(&devtree_lock, flags);
1920 rc = __of_update_property(np, newprop, &oldprop);
1921 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1922
1923 if (!rc)
1924 __of_update_property_sysfs(np, newprop, oldprop);
1925
1926 mutex_unlock(&of_mutex);
1927
1928 if (!rc)
1929 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1930
1931 return rc;
1932}
1933
1934static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1935 int id, const char *stem, int stem_len)
1936{
1937 ap->np = np;
1938 ap->id = id;
1939 strncpy(ap->stem, stem, stem_len);
1940 ap->stem[stem_len] = 0;
1941 list_add_tail(&ap->link, &aliases_lookup);
1942 pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n",
1943 ap->alias, ap->stem, ap->id, np);
1944}
1945
1946/**
1947 * of_alias_scan - Scan all properties of the 'aliases' node
1948 *
1949 * The function scans all the properties of the 'aliases' node and populates
1950 * the global lookup table with the properties. It returns the
1951 * number of alias properties found, or an error code in case of failure.
1952 *
1953 * @dt_alloc: An allocator that provides a virtual address to memory
1954 * for storing the resulting tree
1955 */
1956void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1957{
1958 struct property *pp;
1959
1960 of_aliases = of_find_node_by_path("/aliases");
1961 of_chosen = of_find_node_by_path("/chosen");
1962 if (of_chosen == NULL)
1963 of_chosen = of_find_node_by_path("/chosen@0");
1964
1965 if (of_chosen) {
1966 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1967 const char *name = NULL;
1968
1969 if (of_property_read_string(of_chosen, "stdout-path", &name))
1970 of_property_read_string(of_chosen, "linux,stdout-path",
1971 &name);
1972 if (IS_ENABLED(CONFIG_PPC) && !name)
1973 of_property_read_string(of_aliases, "stdout", &name);
1974 if (name)
1975 of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
1976 }
1977
1978 if (!of_aliases)
1979 return;
1980
1981 for_each_property_of_node(of_aliases, pp) {
1982 const char *start = pp->name;
1983 const char *end = start + strlen(start);
1984 struct device_node *np;
1985 struct alias_prop *ap;
1986 int id, len;
1987
1988 /* Skip those we do not want to proceed */
1989 if (!strcmp(pp->name, "name") ||
1990 !strcmp(pp->name, "phandle") ||
1991 !strcmp(pp->name, "linux,phandle"))
1992 continue;
1993
1994 np = of_find_node_by_path(pp->value);
1995 if (!np)
1996 continue;
1997
1998 /* walk the alias backwards to extract the id and work out
1999 * the 'stem' string */
2000 while (isdigit(*(end-1)) && end > start)
2001 end--;
2002 len = end - start;
2003
2004 if (kstrtoint(end, 10, &id) < 0)
2005 continue;
2006
2007 /* Allocate an alias_prop with enough space for the stem */
2008 ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap));
2009 if (!ap)
2010 continue;
2011 memset(ap, 0, sizeof(*ap) + len + 1);
2012 ap->alias = start;
2013 of_alias_add(ap, np, id, start, len);
2014 }
2015}
2016
2017/**
2018 * of_alias_get_id - Get alias id for the given device_node
2019 * @np: Pointer to the given device_node
2020 * @stem: Alias stem of the given device_node
2021 *
2022 * The function travels the lookup table to get the alias id for the given
2023 * device_node and alias stem. It returns the alias id if found.
2024 */
2025int of_alias_get_id(struct device_node *np, const char *stem)
2026{
2027 struct alias_prop *app;
2028 int id = -ENODEV;
2029
2030 mutex_lock(&of_mutex);
2031 list_for_each_entry(app, &aliases_lookup, link) {
2032 if (strcmp(app->stem, stem) != 0)
2033 continue;
2034
2035 if (np == app->np) {
2036 id = app->id;
2037 break;
2038 }
2039 }
2040 mutex_unlock(&of_mutex);
2041
2042 return id;
2043}
2044EXPORT_SYMBOL_GPL(of_alias_get_id);
2045
2046/**
2047 * of_alias_get_alias_list - Get alias list for the given device driver
2048 * @matches: Array of OF device match structures to search in
2049 * @stem: Alias stem of the given device_node
2050 * @bitmap: Bitmap field pointer
2051 * @nbits: Maximum number of alias IDs which can be recorded in bitmap
2052 *
2053 * The function travels the lookup table to record alias ids for the given
2054 * device match structures and alias stem.
2055 *
2056 * Return: 0 or -ENOSYS when !CONFIG_OF or
2057 * -EOVERFLOW if alias ID is greater then allocated nbits
2058 */
2059int of_alias_get_alias_list(const struct of_device_id *matches,
2060 const char *stem, unsigned long *bitmap,
2061 unsigned int nbits)
2062{
2063 struct alias_prop *app;
2064 int ret = 0;
2065
2066 /* Zero bitmap field to make sure that all the time it is clean */
2067 bitmap_zero(bitmap, nbits);
2068
2069 mutex_lock(&of_mutex);
2070 pr_debug("%s: Looking for stem: %s\n", __func__, stem);
2071 list_for_each_entry(app, &aliases_lookup, link) {
2072 pr_debug("%s: stem: %s, id: %d\n",
2073 __func__, app->stem, app->id);
2074
2075 if (strcmp(app->stem, stem) != 0) {
2076 pr_debug("%s: stem comparison didn't pass %s\n",
2077 __func__, app->stem);
2078 continue;
2079 }
2080
2081 if (of_match_node(matches, app->np)) {
2082 pr_debug("%s: Allocated ID %d\n", __func__, app->id);
2083
2084 if (app->id >= nbits) {
2085 pr_warn("%s: ID %d >= than bitmap field %d\n",
2086 __func__, app->id, nbits);
2087 ret = -EOVERFLOW;
2088 } else {
2089 set_bit(app->id, bitmap);
2090 }
2091 }
2092 }
2093 mutex_unlock(&of_mutex);
2094
2095 return ret;
2096}
2097EXPORT_SYMBOL_GPL(of_alias_get_alias_list);
2098
2099/**
2100 * of_alias_get_highest_id - Get highest alias id for the given stem
2101 * @stem: Alias stem to be examined
2102 *
2103 * The function travels the lookup table to get the highest alias id for the
2104 * given alias stem. It returns the alias id if found.
2105 */
2106int of_alias_get_highest_id(const char *stem)
2107{
2108 struct alias_prop *app;
2109 int id = -ENODEV;
2110
2111 mutex_lock(&of_mutex);
2112 list_for_each_entry(app, &aliases_lookup, link) {
2113 if (strcmp(app->stem, stem) != 0)
2114 continue;
2115
2116 if (app->id > id)
2117 id = app->id;
2118 }
2119 mutex_unlock(&of_mutex);
2120
2121 return id;
2122}
2123EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
2124
2125/**
2126 * of_console_check() - Test and setup console for DT setup
2127 * @dn - Pointer to device node
2128 * @name - Name to use for preferred console without index. ex. "ttyS"
2129 * @index - Index to use for preferred console.
2130 *
2131 * Check if the given device node matches the stdout-path property in the
2132 * /chosen node. If it does then register it as the preferred console and return
2133 * TRUE. Otherwise return FALSE.
2134 */
2135bool of_console_check(struct device_node *dn, char *name, int index)
2136{
2137 if (!dn || dn != of_stdout || console_set_on_cmdline)
2138 return false;
2139
2140 /*
2141 * XXX: cast `options' to char pointer to suppress complication
2142 * warnings: printk, UART and console drivers expect char pointer.
2143 */
2144 return !add_preferred_console(name, index, (char *)of_stdout_options);
2145}
2146EXPORT_SYMBOL_GPL(of_console_check);
2147
2148/**
2149 * of_find_next_cache_node - Find a node's subsidiary cache
2150 * @np: node of type "cpu" or "cache"
2151 *
2152 * Returns a node pointer with refcount incremented, use
2153 * of_node_put() on it when done. Caller should hold a reference
2154 * to np.
2155 */
2156struct device_node *of_find_next_cache_node(const struct device_node *np)
2157{
2158 struct device_node *child, *cache_node;
2159
2160 cache_node = of_parse_phandle(np, "l2-cache", 0);
2161 if (!cache_node)
2162 cache_node = of_parse_phandle(np, "next-level-cache", 0);
2163
2164 if (cache_node)
2165 return cache_node;
2166
2167 /* OF on pmac has nodes instead of properties named "l2-cache"
2168 * beneath CPU nodes.
2169 */
2170 if (IS_ENABLED(CONFIG_PPC_PMAC) && of_node_is_type(np, "cpu"))
2171 for_each_child_of_node(np, child)
2172 if (of_node_is_type(child, "cache"))
2173 return child;
2174
2175 return NULL;
2176}
2177
2178/**
2179 * of_find_last_cache_level - Find the level at which the last cache is
2180 * present for the given logical cpu
2181 *
2182 * @cpu: cpu number(logical index) for which the last cache level is needed
2183 *
2184 * Returns the the level at which the last cache is present. It is exactly
2185 * same as the total number of cache levels for the given logical cpu.
2186 */
2187int of_find_last_cache_level(unsigned int cpu)
2188{
2189 u32 cache_level = 0;
2190 struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
2191
2192 while (np) {
2193 prev = np;
2194 of_node_put(np);
2195 np = of_find_next_cache_node(np);
2196 }
2197
2198 of_property_read_u32(prev, "cache-level", &cache_level);
2199
2200 return cache_level;
2201}
2202
2203/**
2204 * of_map_id - Translate an ID through a downstream mapping.
2205 * @np: root complex device node.
2206 * @id: device ID to map.
2207 * @map_name: property name of the map to use.
2208 * @map_mask_name: optional property name of the mask to use.
2209 * @target: optional pointer to a target device node.
2210 * @id_out: optional pointer to receive the translated ID.
2211 *
2212 * Given a device ID, look up the appropriate implementation-defined
2213 * platform ID and/or the target device which receives transactions on that
2214 * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
2215 * @id_out may be NULL if only the other is required. If @target points to
2216 * a non-NULL device node pointer, only entries targeting that node will be
2217 * matched; if it points to a NULL value, it will receive the device node of
2218 * the first matching target phandle, with a reference held.
2219 *
2220 * Return: 0 on success or a standard error code on failure.
2221 */
2222int of_map_id(struct device_node *np, u32 id,
2223 const char *map_name, const char *map_mask_name,
2224 struct device_node **target, u32 *id_out)
2225{
2226 u32 map_mask, masked_id;
2227 int map_len;
2228 const __be32 *map = NULL;
2229
2230 if (!np || !map_name || (!target && !id_out))
2231 return -EINVAL;
2232
2233 map = of_get_property(np, map_name, &map_len);
2234 if (!map) {
2235 if (target)
2236 return -ENODEV;
2237 /* Otherwise, no map implies no translation */
2238 *id_out = id;
2239 return 0;
2240 }
2241
2242 if (!map_len || map_len % (4 * sizeof(*map))) {
2243 pr_err("%pOF: Error: Bad %s length: %d\n", np,
2244 map_name, map_len);
2245 return -EINVAL;
2246 }
2247
2248 /* The default is to select all bits. */
2249 map_mask = 0xffffffff;
2250
2251 /*
2252 * Can be overridden by "{iommu,msi}-map-mask" property.
2253 * If of_property_read_u32() fails, the default is used.
2254 */
2255 if (map_mask_name)
2256 of_property_read_u32(np, map_mask_name, &map_mask);
2257
2258 masked_id = map_mask & id;
2259 for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
2260 struct device_node *phandle_node;
2261 u32 id_base = be32_to_cpup(map + 0);
2262 u32 phandle = be32_to_cpup(map + 1);
2263 u32 out_base = be32_to_cpup(map + 2);
2264 u32 id_len = be32_to_cpup(map + 3);
2265
2266 if (id_base & ~map_mask) {
2267 pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores id-base (0x%x)\n",
2268 np, map_name, map_name,
2269 map_mask, id_base);
2270 return -EFAULT;
2271 }
2272
2273 if (masked_id < id_base || masked_id >= id_base + id_len)
2274 continue;
2275
2276 phandle_node = of_find_node_by_phandle(phandle);
2277 if (!phandle_node)
2278 return -ENODEV;
2279
2280 if (target) {
2281 if (*target)
2282 of_node_put(phandle_node);
2283 else
2284 *target = phandle_node;
2285
2286 if (*target != phandle_node)
2287 continue;
2288 }
2289
2290 if (id_out)
2291 *id_out = masked_id - id_base + out_base;
2292
2293 pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
2294 np, map_name, map_mask, id_base, out_base,
2295 id_len, id, masked_id - id_base + out_base);
2296 return 0;
2297 }
2298
2299 pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name,
2300 id, target && *target ? *target : NULL);
2301
2302 /* Bypasses translation */
2303 if (id_out)
2304 *id_out = id;
2305 return 0;
2306}
2307EXPORT_SYMBOL_GPL(of_map_id);