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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/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;
39EXPORT_SYMBOL(of_chosen);
40struct device_node *of_aliases;
41struct device_node *of_stdout;
42static const char *of_stdout_options;
43
44struct kset *of_kset;
45
46/*
47 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
48 * This mutex must be held whenever modifications are being made to the
49 * device tree. The of_{attach,detach}_node() and
50 * of_{add,remove,update}_property() helpers make sure this happens.
51 */
52DEFINE_MUTEX(of_mutex);
53
54/* use when traversing tree through the child, sibling,
55 * or parent members of struct device_node.
56 */
57DEFINE_RAW_SPINLOCK(devtree_lock);
58
59bool of_node_name_eq(const struct device_node *np, const char *name)
60{
61 const char *node_name;
62 size_t len;
63
64 if (!np)
65 return false;
66
67 node_name = kbasename(np->full_name);
68 len = strchrnul(node_name, '@') - node_name;
69
70 return (strlen(name) == len) && (strncmp(node_name, name, len) == 0);
71}
72EXPORT_SYMBOL(of_node_name_eq);
73
74bool of_node_name_prefix(const struct device_node *np, const char *prefix)
75{
76 if (!np)
77 return false;
78
79 return strncmp(kbasename(np->full_name), prefix, strlen(prefix)) == 0;
80}
81EXPORT_SYMBOL(of_node_name_prefix);
82
83static bool __of_node_is_type(const struct device_node *np, const char *type)
84{
85 const char *match = __of_get_property(np, "device_type", NULL);
86
87 return np && match && type && !strcmp(match, type);
88}
89
90int of_bus_n_addr_cells(struct device_node *np)
91{
92 u32 cells;
93
94 for (; np; np = np->parent)
95 if (!of_property_read_u32(np, "#address-cells", &cells))
96 return cells;
97
98 /* No #address-cells property for the root node */
99 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
100}
101
102int of_n_addr_cells(struct device_node *np)
103{
104 if (np->parent)
105 np = np->parent;
106
107 return of_bus_n_addr_cells(np);
108}
109EXPORT_SYMBOL(of_n_addr_cells);
110
111int of_bus_n_size_cells(struct device_node *np)
112{
113 u32 cells;
114
115 for (; np; np = np->parent)
116 if (!of_property_read_u32(np, "#size-cells", &cells))
117 return cells;
118
119 /* No #size-cells property for the root node */
120 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
121}
122
123int of_n_size_cells(struct device_node *np)
124{
125 if (np->parent)
126 np = np->parent;
127
128 return of_bus_n_size_cells(np);
129}
130EXPORT_SYMBOL(of_n_size_cells);
131
132#ifdef CONFIG_NUMA
133int __weak of_node_to_nid(struct device_node *np)
134{
135 return NUMA_NO_NODE;
136}
137#endif
138
139#define OF_PHANDLE_CACHE_BITS 7
140#define OF_PHANDLE_CACHE_SZ BIT(OF_PHANDLE_CACHE_BITS)
141
142static struct device_node *phandle_cache[OF_PHANDLE_CACHE_SZ];
143
144static u32 of_phandle_cache_hash(phandle handle)
145{
146 return hash_32(handle, OF_PHANDLE_CACHE_BITS);
147}
148
149/*
150 * Caller must hold devtree_lock.
151 */
152void __of_phandle_cache_inv_entry(phandle handle)
153{
154 u32 handle_hash;
155 struct device_node *np;
156
157 if (!handle)
158 return;
159
160 handle_hash = of_phandle_cache_hash(handle);
161
162 np = phandle_cache[handle_hash];
163 if (np && handle == np->phandle)
164 phandle_cache[handle_hash] = NULL;
165}
166
167void __init of_core_init(void)
168{
169 struct device_node *np;
170
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 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
292 *
293 * @cpu: logical cpu index of a core/thread
294 * @phys_id: physical identifier of a core/thread
295 *
296 * CPU logical to physical index mapping is architecture specific.
297 * However this __weak function provides a default match of physical
298 * id to logical cpu index. phys_id provided here is usually values read
299 * from the device tree which must match the hardware internal registers.
300 *
301 * Returns true if the physical identifier and the logical cpu index
302 * correspond to the same core/thread, false otherwise.
303 */
304bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
305{
306 return (u32)phys_id == cpu;
307}
308
309/*
310 * Checks if the given "prop_name" property holds the physical id of the
311 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
312 * NULL, local thread number within the core is returned in it.
313 */
314static bool __of_find_n_match_cpu_property(struct device_node *cpun,
315 const char *prop_name, int cpu, unsigned int *thread)
316{
317 const __be32 *cell;
318 int ac, prop_len, tid;
319 u64 hwid;
320
321 ac = of_n_addr_cells(cpun);
322 cell = of_get_property(cpun, prop_name, &prop_len);
323 if (!cell && !ac && arch_match_cpu_phys_id(cpu, 0))
324 return true;
325 if (!cell || !ac)
326 return false;
327 prop_len /= sizeof(*cell) * ac;
328 for (tid = 0; tid < prop_len; tid++) {
329 hwid = of_read_number(cell, ac);
330 if (arch_match_cpu_phys_id(cpu, hwid)) {
331 if (thread)
332 *thread = tid;
333 return true;
334 }
335 cell += ac;
336 }
337 return false;
338}
339
340/*
341 * arch_find_n_match_cpu_physical_id - See if the given device node is
342 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
343 * else false. If 'thread' is non-NULL, the local thread number within the
344 * core is returned in it.
345 */
346bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
347 int cpu, unsigned int *thread)
348{
349 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
350 * for thread ids on PowerPC. If it doesn't exist fallback to
351 * standard "reg" property.
352 */
353 if (IS_ENABLED(CONFIG_PPC) &&
354 __of_find_n_match_cpu_property(cpun,
355 "ibm,ppc-interrupt-server#s",
356 cpu, thread))
357 return true;
358
359 return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
360}
361
362/**
363 * of_get_cpu_node - Get device node associated with the given logical CPU
364 *
365 * @cpu: CPU number(logical index) for which device node is required
366 * @thread: if not NULL, local thread number within the physical core is
367 * returned
368 *
369 * The main purpose of this function is to retrieve the device node for the
370 * given logical CPU index. It should be used to initialize the of_node in
371 * cpu device. Once of_node in cpu device is populated, all the further
372 * references can use that instead.
373 *
374 * CPU logical to physical index mapping is architecture specific and is built
375 * before booting secondary cores. This function uses arch_match_cpu_phys_id
376 * which can be overridden by architecture specific implementation.
377 *
378 * Return: A node pointer for the logical cpu with refcount incremented, use
379 * of_node_put() on it when done. Returns NULL if not found.
380 */
381struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
382{
383 struct device_node *cpun;
384
385 for_each_of_cpu_node(cpun) {
386 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
387 return cpun;
388 }
389 return NULL;
390}
391EXPORT_SYMBOL(of_get_cpu_node);
392
393/**
394 * of_cpu_node_to_id: Get the logical CPU number for a given device_node
395 *
396 * @cpu_node: Pointer to the device_node for CPU.
397 *
398 * Return: The logical CPU number of the given CPU device_node or -ENODEV if the
399 * CPU is not found.
400 */
401int of_cpu_node_to_id(struct device_node *cpu_node)
402{
403 int cpu;
404 bool found = false;
405 struct device_node *np;
406
407 for_each_possible_cpu(cpu) {
408 np = of_cpu_device_node_get(cpu);
409 found = (cpu_node == np);
410 of_node_put(np);
411 if (found)
412 return cpu;
413 }
414
415 return -ENODEV;
416}
417EXPORT_SYMBOL(of_cpu_node_to_id);
418
419/**
420 * of_get_cpu_state_node - Get CPU's idle state node at the given index
421 *
422 * @cpu_node: The device node for the CPU
423 * @index: The index in the list of the idle states
424 *
425 * Two generic methods can be used to describe a CPU's idle states, either via
426 * a flattened description through the "cpu-idle-states" binding or via the
427 * hierarchical layout, using the "power-domains" and the "domain-idle-states"
428 * bindings. This function check for both and returns the idle state node for
429 * the requested index.
430 *
431 * Return: An idle state node if found at @index. The refcount is incremented
432 * for it, so call of_node_put() on it when done. Returns NULL if not found.
433 */
434struct device_node *of_get_cpu_state_node(struct device_node *cpu_node,
435 int index)
436{
437 struct of_phandle_args args;
438 int err;
439
440 err = of_parse_phandle_with_args(cpu_node, "power-domains",
441 "#power-domain-cells", 0, &args);
442 if (!err) {
443 struct device_node *state_node =
444 of_parse_phandle(args.np, "domain-idle-states", index);
445
446 of_node_put(args.np);
447 if (state_node)
448 return state_node;
449 }
450
451 return of_parse_phandle(cpu_node, "cpu-idle-states", index);
452}
453EXPORT_SYMBOL(of_get_cpu_state_node);
454
455/**
456 * __of_device_is_compatible() - Check if the node matches given constraints
457 * @device: pointer to node
458 * @compat: required compatible string, NULL or "" for any match
459 * @type: required device_type value, NULL or "" for any match
460 * @name: required node name, NULL or "" for any match
461 *
462 * Checks if the given @compat, @type and @name strings match the
463 * properties of the given @device. A constraints can be skipped by
464 * passing NULL or an empty string as the constraint.
465 *
466 * Returns 0 for no match, and a positive integer on match. The return
467 * value is a relative score with larger values indicating better
468 * matches. The score is weighted for the most specific compatible value
469 * to get the highest score. Matching type is next, followed by matching
470 * name. Practically speaking, this results in the following priority
471 * order for matches:
472 *
473 * 1. specific compatible && type && name
474 * 2. specific compatible && type
475 * 3. specific compatible && name
476 * 4. specific compatible
477 * 5. general compatible && type && name
478 * 6. general compatible && type
479 * 7. general compatible && name
480 * 8. general compatible
481 * 9. type && name
482 * 10. type
483 * 11. name
484 */
485static int __of_device_is_compatible(const struct device_node *device,
486 const char *compat, const char *type, const char *name)
487{
488 struct property *prop;
489 const char *cp;
490 int index = 0, score = 0;
491
492 /* Compatible match has highest priority */
493 if (compat && compat[0]) {
494 prop = __of_find_property(device, "compatible", NULL);
495 for (cp = of_prop_next_string(prop, NULL); cp;
496 cp = of_prop_next_string(prop, cp), index++) {
497 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
498 score = INT_MAX/2 - (index << 2);
499 break;
500 }
501 }
502 if (!score)
503 return 0;
504 }
505
506 /* Matching type is better than matching name */
507 if (type && type[0]) {
508 if (!__of_node_is_type(device, type))
509 return 0;
510 score += 2;
511 }
512
513 /* Matching name is a bit better than not */
514 if (name && name[0]) {
515 if (!of_node_name_eq(device, name))
516 return 0;
517 score++;
518 }
519
520 return score;
521}
522
523/** Checks if the given "compat" string matches one of the strings in
524 * the device's "compatible" property
525 */
526int of_device_is_compatible(const struct device_node *device,
527 const char *compat)
528{
529 unsigned long flags;
530 int res;
531
532 raw_spin_lock_irqsave(&devtree_lock, flags);
533 res = __of_device_is_compatible(device, compat, NULL, NULL);
534 raw_spin_unlock_irqrestore(&devtree_lock, flags);
535 return res;
536}
537EXPORT_SYMBOL(of_device_is_compatible);
538
539/** Checks if the device is compatible with any of the entries in
540 * a NULL terminated array of strings. Returns the best match
541 * score or 0.
542 */
543int of_device_compatible_match(struct device_node *device,
544 const char *const *compat)
545{
546 unsigned int tmp, score = 0;
547
548 if (!compat)
549 return 0;
550
551 while (*compat) {
552 tmp = of_device_is_compatible(device, *compat);
553 if (tmp > score)
554 score = tmp;
555 compat++;
556 }
557
558 return score;
559}
560
561/**
562 * of_machine_is_compatible - Test root of device tree for a given compatible value
563 * @compat: compatible string to look for in root node's compatible property.
564 *
565 * Return: A positive integer if the root node has the given value in its
566 * compatible property.
567 */
568int of_machine_is_compatible(const char *compat)
569{
570 struct device_node *root;
571 int rc = 0;
572
573 root = of_find_node_by_path("/");
574 if (root) {
575 rc = of_device_is_compatible(root, compat);
576 of_node_put(root);
577 }
578 return rc;
579}
580EXPORT_SYMBOL(of_machine_is_compatible);
581
582/**
583 * __of_device_is_available - check if a device is available for use
584 *
585 * @device: Node to check for availability, with locks already held
586 *
587 * Return: True if the status property is absent or set to "okay" or "ok",
588 * false otherwise
589 */
590static bool __of_device_is_available(const struct device_node *device)
591{
592 const char *status;
593 int statlen;
594
595 if (!device)
596 return false;
597
598 status = __of_get_property(device, "status", &statlen);
599 if (status == NULL)
600 return true;
601
602 if (statlen > 0) {
603 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
604 return true;
605 }
606
607 return false;
608}
609
610/**
611 * of_device_is_available - check if a device is available for use
612 *
613 * @device: Node to check for availability
614 *
615 * Return: True if the status property is absent or set to "okay" or "ok",
616 * false otherwise
617 */
618bool of_device_is_available(const struct device_node *device)
619{
620 unsigned long flags;
621 bool res;
622
623 raw_spin_lock_irqsave(&devtree_lock, flags);
624 res = __of_device_is_available(device);
625 raw_spin_unlock_irqrestore(&devtree_lock, flags);
626 return res;
627
628}
629EXPORT_SYMBOL(of_device_is_available);
630
631/**
632 * of_device_is_big_endian - check if a device has BE registers
633 *
634 * @device: Node to check for endianness
635 *
636 * Return: True if the device has a "big-endian" property, or if the kernel
637 * was compiled for BE *and* the device has a "native-endian" property.
638 * Returns false otherwise.
639 *
640 * Callers would nominally use ioread32be/iowrite32be if
641 * of_device_is_big_endian() == true, or readl/writel otherwise.
642 */
643bool of_device_is_big_endian(const struct device_node *device)
644{
645 if (of_property_read_bool(device, "big-endian"))
646 return true;
647 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
648 of_property_read_bool(device, "native-endian"))
649 return true;
650 return false;
651}
652EXPORT_SYMBOL(of_device_is_big_endian);
653
654/**
655 * of_get_parent - Get a node's parent if any
656 * @node: Node to get parent
657 *
658 * Return: A node pointer with refcount incremented, use
659 * of_node_put() on it when done.
660 */
661struct device_node *of_get_parent(const struct device_node *node)
662{
663 struct device_node *np;
664 unsigned long flags;
665
666 if (!node)
667 return NULL;
668
669 raw_spin_lock_irqsave(&devtree_lock, flags);
670 np = of_node_get(node->parent);
671 raw_spin_unlock_irqrestore(&devtree_lock, flags);
672 return np;
673}
674EXPORT_SYMBOL(of_get_parent);
675
676/**
677 * of_get_next_parent - Iterate to a node's parent
678 * @node: Node to get parent of
679 *
680 * This is like of_get_parent() except that it drops the
681 * refcount on the passed node, making it suitable for iterating
682 * through a node's parents.
683 *
684 * Return: A node pointer with refcount incremented, use
685 * of_node_put() on it when done.
686 */
687struct device_node *of_get_next_parent(struct device_node *node)
688{
689 struct device_node *parent;
690 unsigned long flags;
691
692 if (!node)
693 return NULL;
694
695 raw_spin_lock_irqsave(&devtree_lock, flags);
696 parent = of_node_get(node->parent);
697 of_node_put(node);
698 raw_spin_unlock_irqrestore(&devtree_lock, flags);
699 return parent;
700}
701EXPORT_SYMBOL(of_get_next_parent);
702
703static struct device_node *__of_get_next_child(const struct device_node *node,
704 struct device_node *prev)
705{
706 struct device_node *next;
707
708 if (!node)
709 return NULL;
710
711 next = prev ? prev->sibling : node->child;
712 for (; next; next = next->sibling)
713 if (of_node_get(next))
714 break;
715 of_node_put(prev);
716 return next;
717}
718#define __for_each_child_of_node(parent, child) \
719 for (child = __of_get_next_child(parent, NULL); child != NULL; \
720 child = __of_get_next_child(parent, child))
721
722/**
723 * of_get_next_child - Iterate a node childs
724 * @node: parent node
725 * @prev: previous child of the parent node, or NULL to get first
726 *
727 * Return: A node pointer with refcount incremented, use of_node_put() on
728 * it when done. Returns NULL when prev is the last child. Decrements the
729 * refcount of prev.
730 */
731struct device_node *of_get_next_child(const struct device_node *node,
732 struct device_node *prev)
733{
734 struct device_node *next;
735 unsigned long flags;
736
737 raw_spin_lock_irqsave(&devtree_lock, flags);
738 next = __of_get_next_child(node, prev);
739 raw_spin_unlock_irqrestore(&devtree_lock, flags);
740 return next;
741}
742EXPORT_SYMBOL(of_get_next_child);
743
744/**
745 * of_get_next_available_child - Find the next available child node
746 * @node: parent node
747 * @prev: previous child of the parent node, or NULL to get first
748 *
749 * This function is like of_get_next_child(), except that it
750 * automatically skips any disabled nodes (i.e. status = "disabled").
751 */
752struct device_node *of_get_next_available_child(const struct device_node *node,
753 struct device_node *prev)
754{
755 struct device_node *next;
756 unsigned long flags;
757
758 if (!node)
759 return NULL;
760
761 raw_spin_lock_irqsave(&devtree_lock, flags);
762 next = prev ? prev->sibling : node->child;
763 for (; next; next = next->sibling) {
764 if (!__of_device_is_available(next))
765 continue;
766 if (of_node_get(next))
767 break;
768 }
769 of_node_put(prev);
770 raw_spin_unlock_irqrestore(&devtree_lock, flags);
771 return next;
772}
773EXPORT_SYMBOL(of_get_next_available_child);
774
775/**
776 * of_get_next_cpu_node - Iterate on cpu nodes
777 * @prev: previous child of the /cpus node, or NULL to get first
778 *
779 * Return: A cpu node pointer with refcount incremented, use of_node_put()
780 * on it when done. Returns NULL when prev is the last child. Decrements
781 * the refcount of prev.
782 */
783struct device_node *of_get_next_cpu_node(struct device_node *prev)
784{
785 struct device_node *next = NULL;
786 unsigned long flags;
787 struct device_node *node;
788
789 if (!prev)
790 node = of_find_node_by_path("/cpus");
791
792 raw_spin_lock_irqsave(&devtree_lock, flags);
793 if (prev)
794 next = prev->sibling;
795 else if (node) {
796 next = node->child;
797 of_node_put(node);
798 }
799 for (; next; next = next->sibling) {
800 if (!(of_node_name_eq(next, "cpu") ||
801 __of_node_is_type(next, "cpu")))
802 continue;
803 if (of_node_get(next))
804 break;
805 }
806 of_node_put(prev);
807 raw_spin_unlock_irqrestore(&devtree_lock, flags);
808 return next;
809}
810EXPORT_SYMBOL(of_get_next_cpu_node);
811
812/**
813 * of_get_compatible_child - Find compatible child node
814 * @parent: parent node
815 * @compatible: compatible string
816 *
817 * Lookup child node whose compatible property contains the given compatible
818 * string.
819 *
820 * Return: a node pointer with refcount incremented, use of_node_put() on it
821 * when done; or NULL if not found.
822 */
823struct device_node *of_get_compatible_child(const struct device_node *parent,
824 const char *compatible)
825{
826 struct device_node *child;
827
828 for_each_child_of_node(parent, child) {
829 if (of_device_is_compatible(child, compatible))
830 break;
831 }
832
833 return child;
834}
835EXPORT_SYMBOL(of_get_compatible_child);
836
837/**
838 * of_get_child_by_name - Find the child node by name for a given parent
839 * @node: parent node
840 * @name: child name to look for.
841 *
842 * This function looks for child node for given matching name
843 *
844 * Return: A node pointer if found, with refcount incremented, use
845 * of_node_put() on it when done.
846 * Returns NULL if node is not found.
847 */
848struct device_node *of_get_child_by_name(const struct device_node *node,
849 const char *name)
850{
851 struct device_node *child;
852
853 for_each_child_of_node(node, child)
854 if (of_node_name_eq(child, name))
855 break;
856 return child;
857}
858EXPORT_SYMBOL(of_get_child_by_name);
859
860struct device_node *__of_find_node_by_path(struct device_node *parent,
861 const char *path)
862{
863 struct device_node *child;
864 int len;
865
866 len = strcspn(path, "/:");
867 if (!len)
868 return NULL;
869
870 __for_each_child_of_node(parent, child) {
871 const char *name = kbasename(child->full_name);
872 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
873 return child;
874 }
875 return NULL;
876}
877
878struct device_node *__of_find_node_by_full_path(struct device_node *node,
879 const char *path)
880{
881 const char *separator = strchr(path, ':');
882
883 while (node && *path == '/') {
884 struct device_node *tmp = node;
885
886 path++; /* Increment past '/' delimiter */
887 node = __of_find_node_by_path(node, path);
888 of_node_put(tmp);
889 path = strchrnul(path, '/');
890 if (separator && separator < path)
891 break;
892 }
893 return node;
894}
895
896/**
897 * of_find_node_opts_by_path - Find a node matching a full OF path
898 * @path: Either the full path to match, or if the path does not
899 * start with '/', the name of a property of the /aliases
900 * node (an alias). In the case of an alias, the node
901 * matching the alias' value will be returned.
902 * @opts: Address of a pointer into which to store the start of
903 * an options string appended to the end of the path with
904 * a ':' separator.
905 *
906 * Valid paths:
907 * * /foo/bar Full path
908 * * foo Valid alias
909 * * foo/bar Valid alias + relative path
910 *
911 * Return: A node pointer with refcount incremented, use
912 * of_node_put() on it when done.
913 */
914struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
915{
916 struct device_node *np = NULL;
917 struct property *pp;
918 unsigned long flags;
919 const char *separator = strchr(path, ':');
920
921 if (opts)
922 *opts = separator ? separator + 1 : NULL;
923
924 if (strcmp(path, "/") == 0)
925 return of_node_get(of_root);
926
927 /* The path could begin with an alias */
928 if (*path != '/') {
929 int len;
930 const char *p = separator;
931
932 if (!p)
933 p = strchrnul(path, '/');
934 len = p - path;
935
936 /* of_aliases must not be NULL */
937 if (!of_aliases)
938 return NULL;
939
940 for_each_property_of_node(of_aliases, pp) {
941 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
942 np = of_find_node_by_path(pp->value);
943 break;
944 }
945 }
946 if (!np)
947 return NULL;
948 path = p;
949 }
950
951 /* Step down the tree matching path components */
952 raw_spin_lock_irqsave(&devtree_lock, flags);
953 if (!np)
954 np = of_node_get(of_root);
955 np = __of_find_node_by_full_path(np, path);
956 raw_spin_unlock_irqrestore(&devtree_lock, flags);
957 return np;
958}
959EXPORT_SYMBOL(of_find_node_opts_by_path);
960
961/**
962 * of_find_node_by_name - Find a node by its "name" property
963 * @from: The node to start searching from or NULL; the node
964 * you pass will not be searched, only the next one
965 * will. Typically, you pass what the previous call
966 * returned. of_node_put() will be called on @from.
967 * @name: The name string to match against
968 *
969 * Return: A node pointer with refcount incremented, use
970 * of_node_put() on it when done.
971 */
972struct device_node *of_find_node_by_name(struct device_node *from,
973 const char *name)
974{
975 struct device_node *np;
976 unsigned long flags;
977
978 raw_spin_lock_irqsave(&devtree_lock, flags);
979 for_each_of_allnodes_from(from, np)
980 if (of_node_name_eq(np, name) && of_node_get(np))
981 break;
982 of_node_put(from);
983 raw_spin_unlock_irqrestore(&devtree_lock, flags);
984 return np;
985}
986EXPORT_SYMBOL(of_find_node_by_name);
987
988/**
989 * of_find_node_by_type - Find a node by its "device_type" property
990 * @from: The node to start searching from, or NULL to start searching
991 * the entire device tree. The node you pass will not be
992 * searched, only the next one will; typically, you pass
993 * what the previous call returned. of_node_put() will be
994 * called on from for you.
995 * @type: The type string to match against
996 *
997 * Return: A node pointer with refcount incremented, use
998 * of_node_put() on it when done.
999 */
1000struct device_node *of_find_node_by_type(struct device_node *from,
1001 const char *type)
1002{
1003 struct device_node *np;
1004 unsigned long flags;
1005
1006 raw_spin_lock_irqsave(&devtree_lock, flags);
1007 for_each_of_allnodes_from(from, np)
1008 if (__of_node_is_type(np, type) && of_node_get(np))
1009 break;
1010 of_node_put(from);
1011 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1012 return np;
1013}
1014EXPORT_SYMBOL(of_find_node_by_type);
1015
1016/**
1017 * of_find_compatible_node - Find a node based on type and one of the
1018 * tokens in its "compatible" property
1019 * @from: The node to start searching from or NULL, the node
1020 * you pass will not be searched, only the next one
1021 * will; typically, you pass what the previous call
1022 * returned. of_node_put() will be called on it
1023 * @type: The type string to match "device_type" or NULL to ignore
1024 * @compatible: The string to match to one of the tokens in the device
1025 * "compatible" list.
1026 *
1027 * Return: A node pointer with refcount incremented, use
1028 * of_node_put() on it when done.
1029 */
1030struct device_node *of_find_compatible_node(struct device_node *from,
1031 const char *type, const char *compatible)
1032{
1033 struct device_node *np;
1034 unsigned long flags;
1035
1036 raw_spin_lock_irqsave(&devtree_lock, flags);
1037 for_each_of_allnodes_from(from, np)
1038 if (__of_device_is_compatible(np, compatible, type, NULL) &&
1039 of_node_get(np))
1040 break;
1041 of_node_put(from);
1042 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1043 return np;
1044}
1045EXPORT_SYMBOL(of_find_compatible_node);
1046
1047/**
1048 * of_find_node_with_property - Find a node which has a property with
1049 * the given name.
1050 * @from: The node to start searching from or NULL, the node
1051 * you pass will not be searched, only the next one
1052 * will; typically, you pass what the previous call
1053 * returned. of_node_put() will be called on it
1054 * @prop_name: The name of the property to look for.
1055 *
1056 * Return: A node pointer with refcount incremented, use
1057 * of_node_put() on it when done.
1058 */
1059struct device_node *of_find_node_with_property(struct device_node *from,
1060 const char *prop_name)
1061{
1062 struct device_node *np;
1063 struct property *pp;
1064 unsigned long flags;
1065
1066 raw_spin_lock_irqsave(&devtree_lock, flags);
1067 for_each_of_allnodes_from(from, np) {
1068 for (pp = np->properties; pp; pp = pp->next) {
1069 if (of_prop_cmp(pp->name, prop_name) == 0) {
1070 of_node_get(np);
1071 goto out;
1072 }
1073 }
1074 }
1075out:
1076 of_node_put(from);
1077 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1078 return np;
1079}
1080EXPORT_SYMBOL(of_find_node_with_property);
1081
1082static
1083const struct of_device_id *__of_match_node(const struct of_device_id *matches,
1084 const struct device_node *node)
1085{
1086 const struct of_device_id *best_match = NULL;
1087 int score, best_score = 0;
1088
1089 if (!matches)
1090 return NULL;
1091
1092 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
1093 score = __of_device_is_compatible(node, matches->compatible,
1094 matches->type, matches->name);
1095 if (score > best_score) {
1096 best_match = matches;
1097 best_score = score;
1098 }
1099 }
1100
1101 return best_match;
1102}
1103
1104/**
1105 * of_match_node - Tell if a device_node has a matching of_match structure
1106 * @matches: array of of device match structures to search in
1107 * @node: the of device structure to match against
1108 *
1109 * Low level utility function used by device matching.
1110 */
1111const struct of_device_id *of_match_node(const struct of_device_id *matches,
1112 const struct device_node *node)
1113{
1114 const struct of_device_id *match;
1115 unsigned long flags;
1116
1117 raw_spin_lock_irqsave(&devtree_lock, flags);
1118 match = __of_match_node(matches, node);
1119 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1120 return match;
1121}
1122EXPORT_SYMBOL(of_match_node);
1123
1124/**
1125 * of_find_matching_node_and_match - Find a node based on an of_device_id
1126 * match table.
1127 * @from: The node to start searching from or NULL, the node
1128 * you pass will not be searched, only the next one
1129 * will; typically, you pass what the previous call
1130 * returned. of_node_put() will be called on it
1131 * @matches: array of of device match structures to search in
1132 * @match: Updated to point at the matches entry which matched
1133 *
1134 * Return: A node pointer with refcount incremented, use
1135 * of_node_put() on it when done.
1136 */
1137struct device_node *of_find_matching_node_and_match(struct device_node *from,
1138 const struct of_device_id *matches,
1139 const struct of_device_id **match)
1140{
1141 struct device_node *np;
1142 const struct of_device_id *m;
1143 unsigned long flags;
1144
1145 if (match)
1146 *match = NULL;
1147
1148 raw_spin_lock_irqsave(&devtree_lock, flags);
1149 for_each_of_allnodes_from(from, np) {
1150 m = __of_match_node(matches, np);
1151 if (m && of_node_get(np)) {
1152 if (match)
1153 *match = m;
1154 break;
1155 }
1156 }
1157 of_node_put(from);
1158 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1159 return np;
1160}
1161EXPORT_SYMBOL(of_find_matching_node_and_match);
1162
1163/**
1164 * of_modalias_node - Lookup appropriate modalias for a device node
1165 * @node: pointer to a device tree node
1166 * @modalias: Pointer to buffer that modalias value will be copied into
1167 * @len: Length of modalias value
1168 *
1169 * Based on the value of the compatible property, this routine will attempt
1170 * to choose an appropriate modalias value for a particular device tree node.
1171 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1172 * from the first entry in the compatible list property.
1173 *
1174 * Return: This routine returns 0 on success, <0 on failure.
1175 */
1176int of_modalias_node(struct device_node *node, char *modalias, int len)
1177{
1178 const char *compatible, *p;
1179 int cplen;
1180
1181 compatible = of_get_property(node, "compatible", &cplen);
1182 if (!compatible || strlen(compatible) > cplen)
1183 return -ENODEV;
1184 p = strchr(compatible, ',');
1185 strlcpy(modalias, p ? p + 1 : compatible, len);
1186 return 0;
1187}
1188EXPORT_SYMBOL_GPL(of_modalias_node);
1189
1190/**
1191 * of_find_node_by_phandle - Find a node given a phandle
1192 * @handle: phandle of the node to find
1193 *
1194 * Return: A node pointer with refcount incremented, use
1195 * of_node_put() on it when done.
1196 */
1197struct device_node *of_find_node_by_phandle(phandle handle)
1198{
1199 struct device_node *np = NULL;
1200 unsigned long flags;
1201 u32 handle_hash;
1202
1203 if (!handle)
1204 return NULL;
1205
1206 handle_hash = of_phandle_cache_hash(handle);
1207
1208 raw_spin_lock_irqsave(&devtree_lock, flags);
1209
1210 if (phandle_cache[handle_hash] &&
1211 handle == phandle_cache[handle_hash]->phandle)
1212 np = phandle_cache[handle_hash];
1213
1214 if (!np) {
1215 for_each_of_allnodes(np)
1216 if (np->phandle == handle &&
1217 !of_node_check_flag(np, OF_DETACHED)) {
1218 phandle_cache[handle_hash] = np;
1219 break;
1220 }
1221 }
1222
1223 of_node_get(np);
1224 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1225 return np;
1226}
1227EXPORT_SYMBOL(of_find_node_by_phandle);
1228
1229void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1230{
1231 int i;
1232 printk("%s %pOF", msg, args->np);
1233 for (i = 0; i < args->args_count; i++) {
1234 const char delim = i ? ',' : ':';
1235
1236 pr_cont("%c%08x", delim, args->args[i]);
1237 }
1238 pr_cont("\n");
1239}
1240
1241int of_phandle_iterator_init(struct of_phandle_iterator *it,
1242 const struct device_node *np,
1243 const char *list_name,
1244 const char *cells_name,
1245 int cell_count)
1246{
1247 const __be32 *list;
1248 int size;
1249
1250 memset(it, 0, sizeof(*it));
1251
1252 /*
1253 * one of cell_count or cells_name must be provided to determine the
1254 * argument length.
1255 */
1256 if (cell_count < 0 && !cells_name)
1257 return -EINVAL;
1258
1259 list = of_get_property(np, list_name, &size);
1260 if (!list)
1261 return -ENOENT;
1262
1263 it->cells_name = cells_name;
1264 it->cell_count = cell_count;
1265 it->parent = np;
1266 it->list_end = list + size / sizeof(*list);
1267 it->phandle_end = list;
1268 it->cur = list;
1269
1270 return 0;
1271}
1272EXPORT_SYMBOL_GPL(of_phandle_iterator_init);
1273
1274int of_phandle_iterator_next(struct of_phandle_iterator *it)
1275{
1276 uint32_t count = 0;
1277
1278 if (it->node) {
1279 of_node_put(it->node);
1280 it->node = NULL;
1281 }
1282
1283 if (!it->cur || it->phandle_end >= it->list_end)
1284 return -ENOENT;
1285
1286 it->cur = it->phandle_end;
1287
1288 /* If phandle is 0, then it is an empty entry with no arguments. */
1289 it->phandle = be32_to_cpup(it->cur++);
1290
1291 if (it->phandle) {
1292
1293 /*
1294 * Find the provider node and parse the #*-cells property to
1295 * determine the argument length.
1296 */
1297 it->node = of_find_node_by_phandle(it->phandle);
1298
1299 if (it->cells_name) {
1300 if (!it->node) {
1301 pr_err("%pOF: could not find phandle %d\n",
1302 it->parent, it->phandle);
1303 goto err;
1304 }
1305
1306 if (of_property_read_u32(it->node, it->cells_name,
1307 &count)) {
1308 /*
1309 * If both cell_count and cells_name is given,
1310 * fall back to cell_count in absence
1311 * of the cells_name property
1312 */
1313 if (it->cell_count >= 0) {
1314 count = it->cell_count;
1315 } else {
1316 pr_err("%pOF: could not get %s for %pOF\n",
1317 it->parent,
1318 it->cells_name,
1319 it->node);
1320 goto err;
1321 }
1322 }
1323 } else {
1324 count = it->cell_count;
1325 }
1326
1327 /*
1328 * Make sure that the arguments actually fit in the remaining
1329 * property data length
1330 */
1331 if (it->cur + count > it->list_end) {
1332 pr_err("%pOF: %s = %d found %d\n",
1333 it->parent, it->cells_name,
1334 count, it->cell_count);
1335 goto err;
1336 }
1337 }
1338
1339 it->phandle_end = it->cur + count;
1340 it->cur_count = count;
1341
1342 return 0;
1343
1344err:
1345 if (it->node) {
1346 of_node_put(it->node);
1347 it->node = NULL;
1348 }
1349
1350 return -EINVAL;
1351}
1352EXPORT_SYMBOL_GPL(of_phandle_iterator_next);
1353
1354int of_phandle_iterator_args(struct of_phandle_iterator *it,
1355 uint32_t *args,
1356 int size)
1357{
1358 int i, count;
1359
1360 count = it->cur_count;
1361
1362 if (WARN_ON(size < count))
1363 count = size;
1364
1365 for (i = 0; i < count; i++)
1366 args[i] = be32_to_cpup(it->cur++);
1367
1368 return count;
1369}
1370
1371static int __of_parse_phandle_with_args(const struct device_node *np,
1372 const char *list_name,
1373 const char *cells_name,
1374 int cell_count, int index,
1375 struct of_phandle_args *out_args)
1376{
1377 struct of_phandle_iterator it;
1378 int rc, cur_index = 0;
1379
1380 /* Loop over the phandles until all the requested entry is found */
1381 of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
1382 /*
1383 * All of the error cases bail out of the loop, so at
1384 * this point, the parsing is successful. If the requested
1385 * index matches, then fill the out_args structure and return,
1386 * or return -ENOENT for an empty entry.
1387 */
1388 rc = -ENOENT;
1389 if (cur_index == index) {
1390 if (!it.phandle)
1391 goto err;
1392
1393 if (out_args) {
1394 int c;
1395
1396 c = of_phandle_iterator_args(&it,
1397 out_args->args,
1398 MAX_PHANDLE_ARGS);
1399 out_args->np = it.node;
1400 out_args->args_count = c;
1401 } else {
1402 of_node_put(it.node);
1403 }
1404
1405 /* Found it! return success */
1406 return 0;
1407 }
1408
1409 cur_index++;
1410 }
1411
1412 /*
1413 * Unlock node before returning result; will be one of:
1414 * -ENOENT : index is for empty phandle
1415 * -EINVAL : parsing error on data
1416 */
1417
1418 err:
1419 of_node_put(it.node);
1420 return rc;
1421}
1422
1423/**
1424 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1425 * @np: Pointer to device node holding phandle property
1426 * @phandle_name: Name of property holding a phandle value
1427 * @index: For properties holding a table of phandles, this is the index into
1428 * the table
1429 *
1430 * Return: The device_node pointer with refcount incremented. Use
1431 * of_node_put() on it when done.
1432 */
1433struct device_node *of_parse_phandle(const struct device_node *np,
1434 const char *phandle_name, int index)
1435{
1436 struct of_phandle_args args;
1437
1438 if (index < 0)
1439 return NULL;
1440
1441 if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1442 index, &args))
1443 return NULL;
1444
1445 return args.np;
1446}
1447EXPORT_SYMBOL(of_parse_phandle);
1448
1449/**
1450 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1451 * @np: pointer to a device tree node containing a list
1452 * @list_name: property name that contains a list
1453 * @cells_name: property name that specifies phandles' arguments count
1454 * @index: index of a phandle to parse out
1455 * @out_args: optional pointer to output arguments structure (will be filled)
1456 *
1457 * This function is useful to parse lists of phandles and their arguments.
1458 * Returns 0 on success and fills out_args, on error returns appropriate
1459 * errno value.
1460 *
1461 * Caller is responsible to call of_node_put() on the returned out_args->np
1462 * pointer.
1463 *
1464 * Example::
1465 *
1466 * phandle1: node1 {
1467 * #list-cells = <2>;
1468 * };
1469 *
1470 * phandle2: node2 {
1471 * #list-cells = <1>;
1472 * };
1473 *
1474 * node3 {
1475 * list = <&phandle1 1 2 &phandle2 3>;
1476 * };
1477 *
1478 * To get a device_node of the ``node2`` node you may call this:
1479 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1480 */
1481int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1482 const char *cells_name, int index,
1483 struct of_phandle_args *out_args)
1484{
1485 int cell_count = -1;
1486
1487 if (index < 0)
1488 return -EINVAL;
1489
1490 /* If cells_name is NULL we assume a cell count of 0 */
1491 if (!cells_name)
1492 cell_count = 0;
1493
1494 return __of_parse_phandle_with_args(np, list_name, cells_name,
1495 cell_count, index, out_args);
1496}
1497EXPORT_SYMBOL(of_parse_phandle_with_args);
1498
1499/**
1500 * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it
1501 * @np: pointer to a device tree node containing a list
1502 * @list_name: property name that contains a list
1503 * @stem_name: stem of property names that specify phandles' arguments count
1504 * @index: index of a phandle to parse out
1505 * @out_args: optional pointer to output arguments structure (will be filled)
1506 *
1507 * This function is useful to parse lists of phandles and their arguments.
1508 * Returns 0 on success and fills out_args, on error returns appropriate errno
1509 * value. The difference between this function and of_parse_phandle_with_args()
1510 * is that this API remaps a phandle if the node the phandle points to has
1511 * a <@stem_name>-map property.
1512 *
1513 * Caller is responsible to call of_node_put() on the returned out_args->np
1514 * pointer.
1515 *
1516 * Example::
1517 *
1518 * phandle1: node1 {
1519 * #list-cells = <2>;
1520 * };
1521 *
1522 * phandle2: node2 {
1523 * #list-cells = <1>;
1524 * };
1525 *
1526 * phandle3: node3 {
1527 * #list-cells = <1>;
1528 * list-map = <0 &phandle2 3>,
1529 * <1 &phandle2 2>,
1530 * <2 &phandle1 5 1>;
1531 * list-map-mask = <0x3>;
1532 * };
1533 *
1534 * node4 {
1535 * list = <&phandle1 1 2 &phandle3 0>;
1536 * };
1537 *
1538 * To get a device_node of the ``node2`` node you may call this:
1539 * of_parse_phandle_with_args(node4, "list", "list", 1, &args);
1540 */
1541int of_parse_phandle_with_args_map(const struct device_node *np,
1542 const char *list_name,
1543 const char *stem_name,
1544 int index, struct of_phandle_args *out_args)
1545{
1546 char *cells_name, *map_name = NULL, *mask_name = NULL;
1547 char *pass_name = NULL;
1548 struct device_node *cur, *new = NULL;
1549 const __be32 *map, *mask, *pass;
1550 static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 };
1551 static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = 0 };
1552 __be32 initial_match_array[MAX_PHANDLE_ARGS];
1553 const __be32 *match_array = initial_match_array;
1554 int i, ret, map_len, match;
1555 u32 list_size, new_size;
1556
1557 if (index < 0)
1558 return -EINVAL;
1559
1560 cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
1561 if (!cells_name)
1562 return -ENOMEM;
1563
1564 ret = -ENOMEM;
1565 map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name);
1566 if (!map_name)
1567 goto free;
1568
1569 mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
1570 if (!mask_name)
1571 goto free;
1572
1573 pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
1574 if (!pass_name)
1575 goto free;
1576
1577 ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
1578 out_args);
1579 if (ret)
1580 goto free;
1581
1582 /* Get the #<list>-cells property */
1583 cur = out_args->np;
1584 ret = of_property_read_u32(cur, cells_name, &list_size);
1585 if (ret < 0)
1586 goto put;
1587
1588 /* Precalculate the match array - this simplifies match loop */
1589 for (i = 0; i < list_size; i++)
1590 initial_match_array[i] = cpu_to_be32(out_args->args[i]);
1591
1592 ret = -EINVAL;
1593 while (cur) {
1594 /* Get the <list>-map property */
1595 map = of_get_property(cur, map_name, &map_len);
1596 if (!map) {
1597 ret = 0;
1598 goto free;
1599 }
1600 map_len /= sizeof(u32);
1601
1602 /* Get the <list>-map-mask property (optional) */
1603 mask = of_get_property(cur, mask_name, NULL);
1604 if (!mask)
1605 mask = dummy_mask;
1606 /* Iterate through <list>-map property */
1607 match = 0;
1608 while (map_len > (list_size + 1) && !match) {
1609 /* Compare specifiers */
1610 match = 1;
1611 for (i = 0; i < list_size; i++, map_len--)
1612 match &= !((match_array[i] ^ *map++) & mask[i]);
1613
1614 of_node_put(new);
1615 new = of_find_node_by_phandle(be32_to_cpup(map));
1616 map++;
1617 map_len--;
1618
1619 /* Check if not found */
1620 if (!new)
1621 goto put;
1622
1623 if (!of_device_is_available(new))
1624 match = 0;
1625
1626 ret = of_property_read_u32(new, cells_name, &new_size);
1627 if (ret)
1628 goto put;
1629
1630 /* Check for malformed properties */
1631 if (WARN_ON(new_size > MAX_PHANDLE_ARGS))
1632 goto put;
1633 if (map_len < new_size)
1634 goto put;
1635
1636 /* Move forward by new node's #<list>-cells amount */
1637 map += new_size;
1638 map_len -= new_size;
1639 }
1640 if (!match)
1641 goto put;
1642
1643 /* Get the <list>-map-pass-thru property (optional) */
1644 pass = of_get_property(cur, pass_name, NULL);
1645 if (!pass)
1646 pass = dummy_pass;
1647
1648 /*
1649 * Successfully parsed a <list>-map translation; copy new
1650 * specifier into the out_args structure, keeping the
1651 * bits specified in <list>-map-pass-thru.
1652 */
1653 match_array = map - new_size;
1654 for (i = 0; i < new_size; i++) {
1655 __be32 val = *(map - new_size + i);
1656
1657 if (i < list_size) {
1658 val &= ~pass[i];
1659 val |= cpu_to_be32(out_args->args[i]) & pass[i];
1660 }
1661
1662 out_args->args[i] = be32_to_cpu(val);
1663 }
1664 out_args->args_count = list_size = new_size;
1665 /* Iterate again with new provider */
1666 out_args->np = new;
1667 of_node_put(cur);
1668 cur = new;
1669 }
1670put:
1671 of_node_put(cur);
1672 of_node_put(new);
1673free:
1674 kfree(mask_name);
1675 kfree(map_name);
1676 kfree(cells_name);
1677 kfree(pass_name);
1678
1679 return ret;
1680}
1681EXPORT_SYMBOL(of_parse_phandle_with_args_map);
1682
1683/**
1684 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1685 * @np: pointer to a device tree node containing a list
1686 * @list_name: property name that contains a list
1687 * @cell_count: number of argument cells following the phandle
1688 * @index: index of a phandle to parse out
1689 * @out_args: optional pointer to output arguments structure (will be filled)
1690 *
1691 * This function is useful to parse lists of phandles and their arguments.
1692 * Returns 0 on success and fills out_args, on error returns appropriate
1693 * errno value.
1694 *
1695 * Caller is responsible to call of_node_put() on the returned out_args->np
1696 * pointer.
1697 *
1698 * Example::
1699 *
1700 * phandle1: node1 {
1701 * };
1702 *
1703 * phandle2: node2 {
1704 * };
1705 *
1706 * node3 {
1707 * list = <&phandle1 0 2 &phandle2 2 3>;
1708 * };
1709 *
1710 * To get a device_node of the ``node2`` node you may call this:
1711 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1712 */
1713int of_parse_phandle_with_fixed_args(const struct device_node *np,
1714 const char *list_name, int cell_count,
1715 int index, struct of_phandle_args *out_args)
1716{
1717 if (index < 0)
1718 return -EINVAL;
1719 return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1720 index, out_args);
1721}
1722EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1723
1724/**
1725 * of_count_phandle_with_args() - Find the number of phandles references in a property
1726 * @np: pointer to a device tree node containing a list
1727 * @list_name: property name that contains a list
1728 * @cells_name: property name that specifies phandles' arguments count
1729 *
1730 * Return: The number of phandle + argument tuples within a property. It
1731 * is a typical pattern to encode a list of phandle and variable
1732 * arguments into a single property. The number of arguments is encoded
1733 * by a property in the phandle-target node. For example, a gpios
1734 * property would contain a list of GPIO specifies consisting of a
1735 * phandle and 1 or more arguments. The number of arguments are
1736 * determined by the #gpio-cells property in the node pointed to by the
1737 * phandle.
1738 */
1739int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1740 const char *cells_name)
1741{
1742 struct of_phandle_iterator it;
1743 int rc, cur_index = 0;
1744
1745 /*
1746 * If cells_name is NULL we assume a cell count of 0. This makes
1747 * counting the phandles trivial as each 32bit word in the list is a
1748 * phandle and no arguments are to consider. So we don't iterate through
1749 * the list but just use the length to determine the phandle count.
1750 */
1751 if (!cells_name) {
1752 const __be32 *list;
1753 int size;
1754
1755 list = of_get_property(np, list_name, &size);
1756 if (!list)
1757 return -ENOENT;
1758
1759 return size / sizeof(*list);
1760 }
1761
1762 rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
1763 if (rc)
1764 return rc;
1765
1766 while ((rc = of_phandle_iterator_next(&it)) == 0)
1767 cur_index += 1;
1768
1769 if (rc != -ENOENT)
1770 return rc;
1771
1772 return cur_index;
1773}
1774EXPORT_SYMBOL(of_count_phandle_with_args);
1775
1776/**
1777 * __of_add_property - Add a property to a node without lock operations
1778 * @np: Caller's Device Node
1779 * @prop: Property to add
1780 */
1781int __of_add_property(struct device_node *np, struct property *prop)
1782{
1783 struct property **next;
1784
1785 prop->next = NULL;
1786 next = &np->properties;
1787 while (*next) {
1788 if (strcmp(prop->name, (*next)->name) == 0)
1789 /* duplicate ! don't insert it */
1790 return -EEXIST;
1791
1792 next = &(*next)->next;
1793 }
1794 *next = prop;
1795
1796 return 0;
1797}
1798
1799/**
1800 * of_add_property - Add a property to a node
1801 * @np: Caller's Device Node
1802 * @prop: Property to add
1803 */
1804int of_add_property(struct device_node *np, struct property *prop)
1805{
1806 unsigned long flags;
1807 int rc;
1808
1809 mutex_lock(&of_mutex);
1810
1811 raw_spin_lock_irqsave(&devtree_lock, flags);
1812 rc = __of_add_property(np, prop);
1813 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1814
1815 if (!rc)
1816 __of_add_property_sysfs(np, prop);
1817
1818 mutex_unlock(&of_mutex);
1819
1820 if (!rc)
1821 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1822
1823 return rc;
1824}
1825
1826int __of_remove_property(struct device_node *np, struct property *prop)
1827{
1828 struct property **next;
1829
1830 for (next = &np->properties; *next; next = &(*next)->next) {
1831 if (*next == prop)
1832 break;
1833 }
1834 if (*next == NULL)
1835 return -ENODEV;
1836
1837 /* found the node */
1838 *next = prop->next;
1839 prop->next = np->deadprops;
1840 np->deadprops = prop;
1841
1842 return 0;
1843}
1844
1845/**
1846 * of_remove_property - Remove a property from a node.
1847 * @np: Caller's Device Node
1848 * @prop: Property to remove
1849 *
1850 * Note that we don't actually remove it, since we have given out
1851 * who-knows-how-many pointers to the data using get-property.
1852 * Instead we just move the property to the "dead properties"
1853 * list, so it won't be found any more.
1854 */
1855int of_remove_property(struct device_node *np, struct property *prop)
1856{
1857 unsigned long flags;
1858 int rc;
1859
1860 if (!prop)
1861 return -ENODEV;
1862
1863 mutex_lock(&of_mutex);
1864
1865 raw_spin_lock_irqsave(&devtree_lock, flags);
1866 rc = __of_remove_property(np, prop);
1867 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1868
1869 if (!rc)
1870 __of_remove_property_sysfs(np, prop);
1871
1872 mutex_unlock(&of_mutex);
1873
1874 if (!rc)
1875 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1876
1877 return rc;
1878}
1879EXPORT_SYMBOL_GPL(of_remove_property);
1880
1881int __of_update_property(struct device_node *np, struct property *newprop,
1882 struct property **oldpropp)
1883{
1884 struct property **next, *oldprop;
1885
1886 for (next = &np->properties; *next; next = &(*next)->next) {
1887 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1888 break;
1889 }
1890 *oldpropp = oldprop = *next;
1891
1892 if (oldprop) {
1893 /* replace the node */
1894 newprop->next = oldprop->next;
1895 *next = newprop;
1896 oldprop->next = np->deadprops;
1897 np->deadprops = oldprop;
1898 } else {
1899 /* new node */
1900 newprop->next = NULL;
1901 *next = newprop;
1902 }
1903
1904 return 0;
1905}
1906
1907/*
1908 * of_update_property - Update a property in a node, if the property does
1909 * not exist, add it.
1910 *
1911 * Note that we don't actually remove it, since we have given out
1912 * who-knows-how-many pointers to the data using get-property.
1913 * Instead we just move the property to the "dead properties" list,
1914 * and add the new property to the property list
1915 */
1916int of_update_property(struct device_node *np, struct property *newprop)
1917{
1918 struct property *oldprop;
1919 unsigned long flags;
1920 int rc;
1921
1922 if (!newprop->name)
1923 return -EINVAL;
1924
1925 mutex_lock(&of_mutex);
1926
1927 raw_spin_lock_irqsave(&devtree_lock, flags);
1928 rc = __of_update_property(np, newprop, &oldprop);
1929 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1930
1931 if (!rc)
1932 __of_update_property_sysfs(np, newprop, oldprop);
1933
1934 mutex_unlock(&of_mutex);
1935
1936 if (!rc)
1937 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1938
1939 return rc;
1940}
1941
1942static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1943 int id, const char *stem, int stem_len)
1944{
1945 ap->np = np;
1946 ap->id = id;
1947 strncpy(ap->stem, stem, stem_len);
1948 ap->stem[stem_len] = 0;
1949 list_add_tail(&ap->link, &aliases_lookup);
1950 pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n",
1951 ap->alias, ap->stem, ap->id, np);
1952}
1953
1954/**
1955 * of_alias_scan - Scan all properties of the 'aliases' node
1956 * @dt_alloc: An allocator that provides a virtual address to memory
1957 * for storing the resulting tree
1958 *
1959 * The function scans all the properties of the 'aliases' node and populates
1960 * the global lookup table with the properties. It returns the
1961 * number of alias properties found, or an error code in case of failure.
1962 */
1963void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1964{
1965 struct property *pp;
1966
1967 of_aliases = of_find_node_by_path("/aliases");
1968 of_chosen = of_find_node_by_path("/chosen");
1969 if (of_chosen == NULL)
1970 of_chosen = of_find_node_by_path("/chosen@0");
1971
1972 if (of_chosen) {
1973 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1974 const char *name = NULL;
1975
1976 if (of_property_read_string(of_chosen, "stdout-path", &name))
1977 of_property_read_string(of_chosen, "linux,stdout-path",
1978 &name);
1979 if (IS_ENABLED(CONFIG_PPC) && !name)
1980 of_property_read_string(of_aliases, "stdout", &name);
1981 if (name)
1982 of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
1983 }
1984
1985 if (!of_aliases)
1986 return;
1987
1988 for_each_property_of_node(of_aliases, pp) {
1989 const char *start = pp->name;
1990 const char *end = start + strlen(start);
1991 struct device_node *np;
1992 struct alias_prop *ap;
1993 int id, len;
1994
1995 /* Skip those we do not want to proceed */
1996 if (!strcmp(pp->name, "name") ||
1997 !strcmp(pp->name, "phandle") ||
1998 !strcmp(pp->name, "linux,phandle"))
1999 continue;
2000
2001 np = of_find_node_by_path(pp->value);
2002 if (!np)
2003 continue;
2004
2005 /* walk the alias backwards to extract the id and work out
2006 * the 'stem' string */
2007 while (isdigit(*(end-1)) && end > start)
2008 end--;
2009 len = end - start;
2010
2011 if (kstrtoint(end, 10, &id) < 0)
2012 continue;
2013
2014 /* Allocate an alias_prop with enough space for the stem */
2015 ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap));
2016 if (!ap)
2017 continue;
2018 memset(ap, 0, sizeof(*ap) + len + 1);
2019 ap->alias = start;
2020 of_alias_add(ap, np, id, start, len);
2021 }
2022}
2023
2024/**
2025 * of_alias_get_id - Get alias id for the given device_node
2026 * @np: Pointer to the given device_node
2027 * @stem: Alias stem of the given device_node
2028 *
2029 * The function travels the lookup table to get the alias id for the given
2030 * device_node and alias stem.
2031 *
2032 * Return: The alias id if found.
2033 */
2034int of_alias_get_id(struct device_node *np, const char *stem)
2035{
2036 struct alias_prop *app;
2037 int id = -ENODEV;
2038
2039 mutex_lock(&of_mutex);
2040 list_for_each_entry(app, &aliases_lookup, link) {
2041 if (strcmp(app->stem, stem) != 0)
2042 continue;
2043
2044 if (np == app->np) {
2045 id = app->id;
2046 break;
2047 }
2048 }
2049 mutex_unlock(&of_mutex);
2050
2051 return id;
2052}
2053EXPORT_SYMBOL_GPL(of_alias_get_id);
2054
2055/**
2056 * of_alias_get_alias_list - Get alias list for the given device driver
2057 * @matches: Array of OF device match structures to search in
2058 * @stem: Alias stem of the given device_node
2059 * @bitmap: Bitmap field pointer
2060 * @nbits: Maximum number of alias IDs which can be recorded in bitmap
2061 *
2062 * The function travels the lookup table to record alias ids for the given
2063 * device match structures and alias stem.
2064 *
2065 * Return: 0 or -ENOSYS when !CONFIG_OF or
2066 * -EOVERFLOW if alias ID is greater then allocated nbits
2067 */
2068int of_alias_get_alias_list(const struct of_device_id *matches,
2069 const char *stem, unsigned long *bitmap,
2070 unsigned int nbits)
2071{
2072 struct alias_prop *app;
2073 int ret = 0;
2074
2075 /* Zero bitmap field to make sure that all the time it is clean */
2076 bitmap_zero(bitmap, nbits);
2077
2078 mutex_lock(&of_mutex);
2079 pr_debug("%s: Looking for stem: %s\n", __func__, stem);
2080 list_for_each_entry(app, &aliases_lookup, link) {
2081 pr_debug("%s: stem: %s, id: %d\n",
2082 __func__, app->stem, app->id);
2083
2084 if (strcmp(app->stem, stem) != 0) {
2085 pr_debug("%s: stem comparison didn't pass %s\n",
2086 __func__, app->stem);
2087 continue;
2088 }
2089
2090 if (of_match_node(matches, app->np)) {
2091 pr_debug("%s: Allocated ID %d\n", __func__, app->id);
2092
2093 if (app->id >= nbits) {
2094 pr_warn("%s: ID %d >= than bitmap field %d\n",
2095 __func__, app->id, nbits);
2096 ret = -EOVERFLOW;
2097 } else {
2098 set_bit(app->id, bitmap);
2099 }
2100 }
2101 }
2102 mutex_unlock(&of_mutex);
2103
2104 return ret;
2105}
2106EXPORT_SYMBOL_GPL(of_alias_get_alias_list);
2107
2108/**
2109 * of_alias_get_highest_id - Get highest alias id for the given stem
2110 * @stem: Alias stem to be examined
2111 *
2112 * The function travels the lookup table to get the highest alias id for the
2113 * given alias stem. It returns the alias id if found.
2114 */
2115int of_alias_get_highest_id(const char *stem)
2116{
2117 struct alias_prop *app;
2118 int id = -ENODEV;
2119
2120 mutex_lock(&of_mutex);
2121 list_for_each_entry(app, &aliases_lookup, link) {
2122 if (strcmp(app->stem, stem) != 0)
2123 continue;
2124
2125 if (app->id > id)
2126 id = app->id;
2127 }
2128 mutex_unlock(&of_mutex);
2129
2130 return id;
2131}
2132EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
2133
2134/**
2135 * of_console_check() - Test and setup console for DT setup
2136 * @dn: Pointer to device node
2137 * @name: Name to use for preferred console without index. ex. "ttyS"
2138 * @index: Index to use for preferred console.
2139 *
2140 * Check if the given device node matches the stdout-path property in the
2141 * /chosen node. If it does then register it as the preferred console.
2142 *
2143 * Return: TRUE if console successfully setup. Otherwise return FALSE.
2144 */
2145bool of_console_check(struct device_node *dn, char *name, int index)
2146{
2147 if (!dn || dn != of_stdout || console_set_on_cmdline)
2148 return false;
2149
2150 /*
2151 * XXX: cast `options' to char pointer to suppress complication
2152 * warnings: printk, UART and console drivers expect char pointer.
2153 */
2154 return !add_preferred_console(name, index, (char *)of_stdout_options);
2155}
2156EXPORT_SYMBOL_GPL(of_console_check);
2157
2158/**
2159 * of_find_next_cache_node - Find a node's subsidiary cache
2160 * @np: node of type "cpu" or "cache"
2161 *
2162 * Return: A node pointer with refcount incremented, use
2163 * of_node_put() on it when done. Caller should hold a reference
2164 * to np.
2165 */
2166struct device_node *of_find_next_cache_node(const struct device_node *np)
2167{
2168 struct device_node *child, *cache_node;
2169
2170 cache_node = of_parse_phandle(np, "l2-cache", 0);
2171 if (!cache_node)
2172 cache_node = of_parse_phandle(np, "next-level-cache", 0);
2173
2174 if (cache_node)
2175 return cache_node;
2176
2177 /* OF on pmac has nodes instead of properties named "l2-cache"
2178 * beneath CPU nodes.
2179 */
2180 if (IS_ENABLED(CONFIG_PPC_PMAC) && of_node_is_type(np, "cpu"))
2181 for_each_child_of_node(np, child)
2182 if (of_node_is_type(child, "cache"))
2183 return child;
2184
2185 return NULL;
2186}
2187
2188/**
2189 * of_find_last_cache_level - Find the level at which the last cache is
2190 * present for the given logical cpu
2191 *
2192 * @cpu: cpu number(logical index) for which the last cache level is needed
2193 *
2194 * Return: The the level at which the last cache is present. It is exactly
2195 * same as the total number of cache levels for the given logical cpu.
2196 */
2197int of_find_last_cache_level(unsigned int cpu)
2198{
2199 u32 cache_level = 0;
2200 struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
2201
2202 while (np) {
2203 prev = np;
2204 of_node_put(np);
2205 np = of_find_next_cache_node(np);
2206 }
2207
2208 of_property_read_u32(prev, "cache-level", &cache_level);
2209
2210 return cache_level;
2211}
2212
2213/**
2214 * of_map_id - Translate an ID through a downstream mapping.
2215 * @np: root complex device node.
2216 * @id: device ID to map.
2217 * @map_name: property name of the map to use.
2218 * @map_mask_name: optional property name of the mask to use.
2219 * @target: optional pointer to a target device node.
2220 * @id_out: optional pointer to receive the translated ID.
2221 *
2222 * Given a device ID, look up the appropriate implementation-defined
2223 * platform ID and/or the target device which receives transactions on that
2224 * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
2225 * @id_out may be NULL if only the other is required. If @target points to
2226 * a non-NULL device node pointer, only entries targeting that node will be
2227 * matched; if it points to a NULL value, it will receive the device node of
2228 * the first matching target phandle, with a reference held.
2229 *
2230 * Return: 0 on success or a standard error code on failure.
2231 */
2232int of_map_id(struct device_node *np, u32 id,
2233 const char *map_name, const char *map_mask_name,
2234 struct device_node **target, u32 *id_out)
2235{
2236 u32 map_mask, masked_id;
2237 int map_len;
2238 const __be32 *map = NULL;
2239
2240 if (!np || !map_name || (!target && !id_out))
2241 return -EINVAL;
2242
2243 map = of_get_property(np, map_name, &map_len);
2244 if (!map) {
2245 if (target)
2246 return -ENODEV;
2247 /* Otherwise, no map implies no translation */
2248 *id_out = id;
2249 return 0;
2250 }
2251
2252 if (!map_len || map_len % (4 * sizeof(*map))) {
2253 pr_err("%pOF: Error: Bad %s length: %d\n", np,
2254 map_name, map_len);
2255 return -EINVAL;
2256 }
2257
2258 /* The default is to select all bits. */
2259 map_mask = 0xffffffff;
2260
2261 /*
2262 * Can be overridden by "{iommu,msi}-map-mask" property.
2263 * If of_property_read_u32() fails, the default is used.
2264 */
2265 if (map_mask_name)
2266 of_property_read_u32(np, map_mask_name, &map_mask);
2267
2268 masked_id = map_mask & id;
2269 for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
2270 struct device_node *phandle_node;
2271 u32 id_base = be32_to_cpup(map + 0);
2272 u32 phandle = be32_to_cpup(map + 1);
2273 u32 out_base = be32_to_cpup(map + 2);
2274 u32 id_len = be32_to_cpup(map + 3);
2275
2276 if (id_base & ~map_mask) {
2277 pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores id-base (0x%x)\n",
2278 np, map_name, map_name,
2279 map_mask, id_base);
2280 return -EFAULT;
2281 }
2282
2283 if (masked_id < id_base || masked_id >= id_base + id_len)
2284 continue;
2285
2286 phandle_node = of_find_node_by_phandle(phandle);
2287 if (!phandle_node)
2288 return -ENODEV;
2289
2290 if (target) {
2291 if (*target)
2292 of_node_put(phandle_node);
2293 else
2294 *target = phandle_node;
2295
2296 if (*target != phandle_node)
2297 continue;
2298 }
2299
2300 if (id_out)
2301 *id_out = masked_id - id_base + out_base;
2302
2303 pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
2304 np, map_name, map_mask, id_base, out_base,
2305 id_len, id, masked_id - id_base + out_base);
2306 return 0;
2307 }
2308
2309 pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name,
2310 id, target && *target ? *target : NULL);
2311
2312 /* Bypasses translation */
2313 if (id_out)
2314 *id_out = id;
2315 return 0;
2316}
2317EXPORT_SYMBOL_GPL(of_map_id);
1/*
2 * Procedures for creating, accessing and interpreting the device tree.
3 *
4 * Paul Mackerras August 1996.
5 * Copyright (C) 1996-2005 Paul Mackerras.
6 *
7 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
8 * {engebret|bergner}@us.ibm.com
9 *
10 * Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
11 *
12 * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
13 * Grant Likely.
14 *
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
19 */
20#include <linux/ctype.h>
21#include <linux/cpu.h>
22#include <linux/module.h>
23#include <linux/of.h>
24#include <linux/of_graph.h>
25#include <linux/spinlock.h>
26#include <linux/slab.h>
27#include <linux/string.h>
28#include <linux/proc_fs.h>
29
30#include "of_private.h"
31
32LIST_HEAD(aliases_lookup);
33
34struct device_node *of_allnodes;
35EXPORT_SYMBOL(of_allnodes);
36struct device_node *of_chosen;
37struct device_node *of_aliases;
38static struct device_node *of_stdout;
39
40static struct kset *of_kset;
41
42/*
43 * Used to protect the of_aliases; but also overloaded to hold off addition of
44 * nodes to sysfs
45 */
46DEFINE_MUTEX(of_aliases_mutex);
47
48/* use when traversing tree through the allnext, child, sibling,
49 * or parent members of struct device_node.
50 */
51DEFINE_RAW_SPINLOCK(devtree_lock);
52
53int of_n_addr_cells(struct device_node *np)
54{
55 const __be32 *ip;
56
57 do {
58 if (np->parent)
59 np = np->parent;
60 ip = of_get_property(np, "#address-cells", NULL);
61 if (ip)
62 return be32_to_cpup(ip);
63 } while (np->parent);
64 /* No #address-cells property for the root node */
65 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
66}
67EXPORT_SYMBOL(of_n_addr_cells);
68
69int of_n_size_cells(struct device_node *np)
70{
71 const __be32 *ip;
72
73 do {
74 if (np->parent)
75 np = np->parent;
76 ip = of_get_property(np, "#size-cells", NULL);
77 if (ip)
78 return be32_to_cpup(ip);
79 } while (np->parent);
80 /* No #size-cells property for the root node */
81 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
82}
83EXPORT_SYMBOL(of_n_size_cells);
84
85#ifdef CONFIG_NUMA
86int __weak of_node_to_nid(struct device_node *np)
87{
88 return numa_node_id();
89}
90#endif
91
92#if defined(CONFIG_OF_DYNAMIC)
93/**
94 * of_node_get - Increment refcount of a node
95 * @node: Node to inc refcount, NULL is supported to
96 * simplify writing of callers
97 *
98 * Returns node.
99 */
100struct device_node *of_node_get(struct device_node *node)
101{
102 if (node)
103 kobject_get(&node->kobj);
104 return node;
105}
106EXPORT_SYMBOL(of_node_get);
107
108static inline struct device_node *kobj_to_device_node(struct kobject *kobj)
109{
110 return container_of(kobj, struct device_node, kobj);
111}
112
113/**
114 * of_node_release - release a dynamically allocated node
115 * @kref: kref element of the node to be released
116 *
117 * In of_node_put() this function is passed to kref_put()
118 * as the destructor.
119 */
120static void of_node_release(struct kobject *kobj)
121{
122 struct device_node *node = kobj_to_device_node(kobj);
123 struct property *prop = node->properties;
124
125 /* We should never be releasing nodes that haven't been detached. */
126 if (!of_node_check_flag(node, OF_DETACHED)) {
127 pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name);
128 dump_stack();
129 return;
130 }
131
132 if (!of_node_check_flag(node, OF_DYNAMIC))
133 return;
134
135 while (prop) {
136 struct property *next = prop->next;
137 kfree(prop->name);
138 kfree(prop->value);
139 kfree(prop);
140 prop = next;
141
142 if (!prop) {
143 prop = node->deadprops;
144 node->deadprops = NULL;
145 }
146 }
147 kfree(node->full_name);
148 kfree(node->data);
149 kfree(node);
150}
151
152/**
153 * of_node_put - Decrement refcount of a node
154 * @node: Node to dec refcount, NULL is supported to
155 * simplify writing of callers
156 *
157 */
158void of_node_put(struct device_node *node)
159{
160 if (node)
161 kobject_put(&node->kobj);
162}
163EXPORT_SYMBOL(of_node_put);
164#else
165static void of_node_release(struct kobject *kobj)
166{
167 /* Without CONFIG_OF_DYNAMIC, no nodes gets freed */
168}
169#endif /* CONFIG_OF_DYNAMIC */
170
171struct kobj_type of_node_ktype = {
172 .release = of_node_release,
173};
174
175static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj,
176 struct bin_attribute *bin_attr, char *buf,
177 loff_t offset, size_t count)
178{
179 struct property *pp = container_of(bin_attr, struct property, attr);
180 return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length);
181}
182
183static const char *safe_name(struct kobject *kobj, const char *orig_name)
184{
185 const char *name = orig_name;
186 struct kernfs_node *kn;
187 int i = 0;
188
189 /* don't be a hero. After 16 tries give up */
190 while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) {
191 sysfs_put(kn);
192 if (name != orig_name)
193 kfree(name);
194 name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i);
195 }
196
197 if (name != orig_name)
198 pr_warn("device-tree: Duplicate name in %s, renamed to \"%s\"\n",
199 kobject_name(kobj), name);
200 return name;
201}
202
203static int __of_add_property_sysfs(struct device_node *np, struct property *pp)
204{
205 int rc;
206
207 /* Important: Don't leak passwords */
208 bool secure = strncmp(pp->name, "security-", 9) == 0;
209
210 sysfs_bin_attr_init(&pp->attr);
211 pp->attr.attr.name = safe_name(&np->kobj, pp->name);
212 pp->attr.attr.mode = secure ? S_IRUSR : S_IRUGO;
213 pp->attr.size = secure ? 0 : pp->length;
214 pp->attr.read = of_node_property_read;
215
216 rc = sysfs_create_bin_file(&np->kobj, &pp->attr);
217 WARN(rc, "error adding attribute %s to node %s\n", pp->name, np->full_name);
218 return rc;
219}
220
221static int __of_node_add(struct device_node *np)
222{
223 const char *name;
224 struct property *pp;
225 int rc;
226
227 np->kobj.kset = of_kset;
228 if (!np->parent) {
229 /* Nodes without parents are new top level trees */
230 rc = kobject_add(&np->kobj, NULL, safe_name(&of_kset->kobj, "base"));
231 } else {
232 name = safe_name(&np->parent->kobj, kbasename(np->full_name));
233 if (!name || !name[0])
234 return -EINVAL;
235
236 rc = kobject_add(&np->kobj, &np->parent->kobj, "%s", name);
237 }
238 if (rc)
239 return rc;
240
241 for_each_property_of_node(np, pp)
242 __of_add_property_sysfs(np, pp);
243
244 return 0;
245}
246
247int of_node_add(struct device_node *np)
248{
249 int rc = 0;
250
251 BUG_ON(!of_node_is_initialized(np));
252
253 /*
254 * Grab the mutex here so that in a race condition between of_init() and
255 * of_node_add(), node addition will still be consistent.
256 */
257 mutex_lock(&of_aliases_mutex);
258 if (of_kset)
259 rc = __of_node_add(np);
260 else
261 /* This scenario may be perfectly valid, but report it anyway */
262 pr_info("of_node_add(%s) before of_init()\n", np->full_name);
263 mutex_unlock(&of_aliases_mutex);
264 return rc;
265}
266
267#if defined(CONFIG_OF_DYNAMIC)
268static void of_node_remove(struct device_node *np)
269{
270 struct property *pp;
271
272 BUG_ON(!of_node_is_initialized(np));
273
274 /* only remove properties if on sysfs */
275 if (of_node_is_attached(np)) {
276 for_each_property_of_node(np, pp)
277 sysfs_remove_bin_file(&np->kobj, &pp->attr);
278 kobject_del(&np->kobj);
279 }
280
281 /* finally remove the kobj_init ref */
282 of_node_put(np);
283}
284#endif
285
286static int __init of_init(void)
287{
288 struct device_node *np;
289
290 /* Create the kset, and register existing nodes */
291 mutex_lock(&of_aliases_mutex);
292 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
293 if (!of_kset) {
294 mutex_unlock(&of_aliases_mutex);
295 return -ENOMEM;
296 }
297 for_each_of_allnodes(np)
298 __of_node_add(np);
299 mutex_unlock(&of_aliases_mutex);
300
301 /* Symlink in /proc as required by userspace ABI */
302 if (of_allnodes)
303 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
304
305 return 0;
306}
307core_initcall(of_init);
308
309static struct property *__of_find_property(const struct device_node *np,
310 const char *name, int *lenp)
311{
312 struct property *pp;
313
314 if (!np)
315 return NULL;
316
317 for (pp = np->properties; pp; pp = pp->next) {
318 if (of_prop_cmp(pp->name, name) == 0) {
319 if (lenp)
320 *lenp = pp->length;
321 break;
322 }
323 }
324
325 return pp;
326}
327
328struct property *of_find_property(const struct device_node *np,
329 const char *name,
330 int *lenp)
331{
332 struct property *pp;
333 unsigned long flags;
334
335 raw_spin_lock_irqsave(&devtree_lock, flags);
336 pp = __of_find_property(np, name, lenp);
337 raw_spin_unlock_irqrestore(&devtree_lock, flags);
338
339 return pp;
340}
341EXPORT_SYMBOL(of_find_property);
342
343/**
344 * of_find_all_nodes - Get next node in global list
345 * @prev: Previous node or NULL to start iteration
346 * of_node_put() will be called on it
347 *
348 * Returns a node pointer with refcount incremented, use
349 * of_node_put() on it when done.
350 */
351struct device_node *of_find_all_nodes(struct device_node *prev)
352{
353 struct device_node *np;
354 unsigned long flags;
355
356 raw_spin_lock_irqsave(&devtree_lock, flags);
357 np = prev ? prev->allnext : of_allnodes;
358 for (; np != NULL; np = np->allnext)
359 if (of_node_get(np))
360 break;
361 of_node_put(prev);
362 raw_spin_unlock_irqrestore(&devtree_lock, flags);
363 return np;
364}
365EXPORT_SYMBOL(of_find_all_nodes);
366
367/*
368 * Find a property with a given name for a given node
369 * and return the value.
370 */
371static const void *__of_get_property(const struct device_node *np,
372 const char *name, int *lenp)
373{
374 struct property *pp = __of_find_property(np, name, lenp);
375
376 return pp ? pp->value : NULL;
377}
378
379/*
380 * Find a property with a given name for a given node
381 * and return the value.
382 */
383const void *of_get_property(const struct device_node *np, const char *name,
384 int *lenp)
385{
386 struct property *pp = of_find_property(np, name, lenp);
387
388 return pp ? pp->value : NULL;
389}
390EXPORT_SYMBOL(of_get_property);
391
392/*
393 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
394 *
395 * @cpu: logical cpu index of a core/thread
396 * @phys_id: physical identifier of a core/thread
397 *
398 * CPU logical to physical index mapping is architecture specific.
399 * However this __weak function provides a default match of physical
400 * id to logical cpu index. phys_id provided here is usually values read
401 * from the device tree which must match the hardware internal registers.
402 *
403 * Returns true if the physical identifier and the logical cpu index
404 * correspond to the same core/thread, false otherwise.
405 */
406bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
407{
408 return (u32)phys_id == cpu;
409}
410
411/**
412 * Checks if the given "prop_name" property holds the physical id of the
413 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
414 * NULL, local thread number within the core is returned in it.
415 */
416static bool __of_find_n_match_cpu_property(struct device_node *cpun,
417 const char *prop_name, int cpu, unsigned int *thread)
418{
419 const __be32 *cell;
420 int ac, prop_len, tid;
421 u64 hwid;
422
423 ac = of_n_addr_cells(cpun);
424 cell = of_get_property(cpun, prop_name, &prop_len);
425 if (!cell || !ac)
426 return false;
427 prop_len /= sizeof(*cell) * ac;
428 for (tid = 0; tid < prop_len; tid++) {
429 hwid = of_read_number(cell, ac);
430 if (arch_match_cpu_phys_id(cpu, hwid)) {
431 if (thread)
432 *thread = tid;
433 return true;
434 }
435 cell += ac;
436 }
437 return false;
438}
439
440/*
441 * arch_find_n_match_cpu_physical_id - See if the given device node is
442 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
443 * else false. If 'thread' is non-NULL, the local thread number within the
444 * core is returned in it.
445 */
446bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
447 int cpu, unsigned int *thread)
448{
449 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
450 * for thread ids on PowerPC. If it doesn't exist fallback to
451 * standard "reg" property.
452 */
453 if (IS_ENABLED(CONFIG_PPC) &&
454 __of_find_n_match_cpu_property(cpun,
455 "ibm,ppc-interrupt-server#s",
456 cpu, thread))
457 return true;
458
459 if (__of_find_n_match_cpu_property(cpun, "reg", cpu, thread))
460 return true;
461
462 return false;
463}
464
465/**
466 * of_get_cpu_node - Get device node associated with the given logical CPU
467 *
468 * @cpu: CPU number(logical index) for which device node is required
469 * @thread: if not NULL, local thread number within the physical core is
470 * returned
471 *
472 * The main purpose of this function is to retrieve the device node for the
473 * given logical CPU index. It should be used to initialize the of_node in
474 * cpu device. Once of_node in cpu device is populated, all the further
475 * references can use that instead.
476 *
477 * CPU logical to physical index mapping is architecture specific and is built
478 * before booting secondary cores. This function uses arch_match_cpu_phys_id
479 * which can be overridden by architecture specific implementation.
480 *
481 * Returns a node pointer for the logical cpu if found, else NULL.
482 */
483struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
484{
485 struct device_node *cpun;
486
487 for_each_node_by_type(cpun, "cpu") {
488 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
489 return cpun;
490 }
491 return NULL;
492}
493EXPORT_SYMBOL(of_get_cpu_node);
494
495/**
496 * __of_device_is_compatible() - Check if the node matches given constraints
497 * @device: pointer to node
498 * @compat: required compatible string, NULL or "" for any match
499 * @type: required device_type value, NULL or "" for any match
500 * @name: required node name, NULL or "" for any match
501 *
502 * Checks if the given @compat, @type and @name strings match the
503 * properties of the given @device. A constraints can be skipped by
504 * passing NULL or an empty string as the constraint.
505 *
506 * Returns 0 for no match, and a positive integer on match. The return
507 * value is a relative score with larger values indicating better
508 * matches. The score is weighted for the most specific compatible value
509 * to get the highest score. Matching type is next, followed by matching
510 * name. Practically speaking, this results in the following priority
511 * order for matches:
512 *
513 * 1. specific compatible && type && name
514 * 2. specific compatible && type
515 * 3. specific compatible && name
516 * 4. specific compatible
517 * 5. general compatible && type && name
518 * 6. general compatible && type
519 * 7. general compatible && name
520 * 8. general compatible
521 * 9. type && name
522 * 10. type
523 * 11. name
524 */
525static int __of_device_is_compatible(const struct device_node *device,
526 const char *compat, const char *type, const char *name)
527{
528 struct property *prop;
529 const char *cp;
530 int index = 0, score = 0;
531
532 /* Compatible match has highest priority */
533 if (compat && compat[0]) {
534 prop = __of_find_property(device, "compatible", NULL);
535 for (cp = of_prop_next_string(prop, NULL); cp;
536 cp = of_prop_next_string(prop, cp), index++) {
537 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
538 score = INT_MAX/2 - (index << 2);
539 break;
540 }
541 }
542 if (!score)
543 return 0;
544 }
545
546 /* Matching type is better than matching name */
547 if (type && type[0]) {
548 if (!device->type || of_node_cmp(type, device->type))
549 return 0;
550 score += 2;
551 }
552
553 /* Matching name is a bit better than not */
554 if (name && name[0]) {
555 if (!device->name || of_node_cmp(name, device->name))
556 return 0;
557 score++;
558 }
559
560 return score;
561}
562
563/** Checks if the given "compat" string matches one of the strings in
564 * the device's "compatible" property
565 */
566int of_device_is_compatible(const struct device_node *device,
567 const char *compat)
568{
569 unsigned long flags;
570 int res;
571
572 raw_spin_lock_irqsave(&devtree_lock, flags);
573 res = __of_device_is_compatible(device, compat, NULL, NULL);
574 raw_spin_unlock_irqrestore(&devtree_lock, flags);
575 return res;
576}
577EXPORT_SYMBOL(of_device_is_compatible);
578
579/**
580 * of_machine_is_compatible - Test root of device tree for a given compatible value
581 * @compat: compatible string to look for in root node's compatible property.
582 *
583 * Returns true if the root node has the given value in its
584 * compatible property.
585 */
586int of_machine_is_compatible(const char *compat)
587{
588 struct device_node *root;
589 int rc = 0;
590
591 root = of_find_node_by_path("/");
592 if (root) {
593 rc = of_device_is_compatible(root, compat);
594 of_node_put(root);
595 }
596 return rc;
597}
598EXPORT_SYMBOL(of_machine_is_compatible);
599
600/**
601 * __of_device_is_available - check if a device is available for use
602 *
603 * @device: Node to check for availability, with locks already held
604 *
605 * Returns 1 if the status property is absent or set to "okay" or "ok",
606 * 0 otherwise
607 */
608static int __of_device_is_available(const struct device_node *device)
609{
610 const char *status;
611 int statlen;
612
613 if (!device)
614 return 0;
615
616 status = __of_get_property(device, "status", &statlen);
617 if (status == NULL)
618 return 1;
619
620 if (statlen > 0) {
621 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
622 return 1;
623 }
624
625 return 0;
626}
627
628/**
629 * of_device_is_available - check if a device is available for use
630 *
631 * @device: Node to check for availability
632 *
633 * Returns 1 if the status property is absent or set to "okay" or "ok",
634 * 0 otherwise
635 */
636int of_device_is_available(const struct device_node *device)
637{
638 unsigned long flags;
639 int res;
640
641 raw_spin_lock_irqsave(&devtree_lock, flags);
642 res = __of_device_is_available(device);
643 raw_spin_unlock_irqrestore(&devtree_lock, flags);
644 return res;
645
646}
647EXPORT_SYMBOL(of_device_is_available);
648
649/**
650 * of_get_parent - Get a node's parent if any
651 * @node: Node to get parent
652 *
653 * Returns a node pointer with refcount incremented, use
654 * of_node_put() on it when done.
655 */
656struct device_node *of_get_parent(const struct device_node *node)
657{
658 struct device_node *np;
659 unsigned long flags;
660
661 if (!node)
662 return NULL;
663
664 raw_spin_lock_irqsave(&devtree_lock, flags);
665 np = of_node_get(node->parent);
666 raw_spin_unlock_irqrestore(&devtree_lock, flags);
667 return np;
668}
669EXPORT_SYMBOL(of_get_parent);
670
671/**
672 * of_get_next_parent - Iterate to a node's parent
673 * @node: Node to get parent of
674 *
675 * This is like of_get_parent() except that it drops the
676 * refcount on the passed node, making it suitable for iterating
677 * through a node's parents.
678 *
679 * Returns a node pointer with refcount incremented, use
680 * of_node_put() on it when done.
681 */
682struct device_node *of_get_next_parent(struct device_node *node)
683{
684 struct device_node *parent;
685 unsigned long flags;
686
687 if (!node)
688 return NULL;
689
690 raw_spin_lock_irqsave(&devtree_lock, flags);
691 parent = of_node_get(node->parent);
692 of_node_put(node);
693 raw_spin_unlock_irqrestore(&devtree_lock, flags);
694 return parent;
695}
696EXPORT_SYMBOL(of_get_next_parent);
697
698/**
699 * of_get_next_child - Iterate a node childs
700 * @node: parent node
701 * @prev: previous child of the parent node, or NULL to get first
702 *
703 * Returns a node pointer with refcount incremented, use
704 * of_node_put() on it when done.
705 */
706struct device_node *of_get_next_child(const struct device_node *node,
707 struct device_node *prev)
708{
709 struct device_node *next;
710 unsigned long flags;
711
712 raw_spin_lock_irqsave(&devtree_lock, flags);
713 next = prev ? prev->sibling : node->child;
714 for (; next; next = next->sibling)
715 if (of_node_get(next))
716 break;
717 of_node_put(prev);
718 raw_spin_unlock_irqrestore(&devtree_lock, flags);
719 return next;
720}
721EXPORT_SYMBOL(of_get_next_child);
722
723/**
724 * of_get_next_available_child - Find the next available child node
725 * @node: parent node
726 * @prev: previous child of the parent node, or NULL to get first
727 *
728 * This function is like of_get_next_child(), except that it
729 * automatically skips any disabled nodes (i.e. status = "disabled").
730 */
731struct device_node *of_get_next_available_child(const struct device_node *node,
732 struct device_node *prev)
733{
734 struct device_node *next;
735 unsigned long flags;
736
737 raw_spin_lock_irqsave(&devtree_lock, flags);
738 next = prev ? prev->sibling : node->child;
739 for (; next; next = next->sibling) {
740 if (!__of_device_is_available(next))
741 continue;
742 if (of_node_get(next))
743 break;
744 }
745 of_node_put(prev);
746 raw_spin_unlock_irqrestore(&devtree_lock, flags);
747 return next;
748}
749EXPORT_SYMBOL(of_get_next_available_child);
750
751/**
752 * of_get_child_by_name - Find the child node by name for a given parent
753 * @node: parent node
754 * @name: child name to look for.
755 *
756 * This function looks for child node for given matching name
757 *
758 * Returns a node pointer if found, with refcount incremented, use
759 * of_node_put() on it when done.
760 * Returns NULL if node is not found.
761 */
762struct device_node *of_get_child_by_name(const struct device_node *node,
763 const char *name)
764{
765 struct device_node *child;
766
767 for_each_child_of_node(node, child)
768 if (child->name && (of_node_cmp(child->name, name) == 0))
769 break;
770 return child;
771}
772EXPORT_SYMBOL(of_get_child_by_name);
773
774/**
775 * of_find_node_by_path - Find a node matching a full OF path
776 * @path: The full path to match
777 *
778 * Returns a node pointer with refcount incremented, use
779 * of_node_put() on it when done.
780 */
781struct device_node *of_find_node_by_path(const char *path)
782{
783 struct device_node *np = of_allnodes;
784 unsigned long flags;
785
786 raw_spin_lock_irqsave(&devtree_lock, flags);
787 for (; np; np = np->allnext) {
788 if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
789 && of_node_get(np))
790 break;
791 }
792 raw_spin_unlock_irqrestore(&devtree_lock, flags);
793 return np;
794}
795EXPORT_SYMBOL(of_find_node_by_path);
796
797/**
798 * of_find_node_by_name - Find a node by its "name" property
799 * @from: The node to start searching from or NULL, the node
800 * you pass will not be searched, only the next one
801 * will; typically, you pass what the previous call
802 * returned. of_node_put() will be called on it
803 * @name: The name string to match against
804 *
805 * Returns a node pointer with refcount incremented, use
806 * of_node_put() on it when done.
807 */
808struct device_node *of_find_node_by_name(struct device_node *from,
809 const char *name)
810{
811 struct device_node *np;
812 unsigned long flags;
813
814 raw_spin_lock_irqsave(&devtree_lock, flags);
815 np = from ? from->allnext : of_allnodes;
816 for (; np; np = np->allnext)
817 if (np->name && (of_node_cmp(np->name, name) == 0)
818 && of_node_get(np))
819 break;
820 of_node_put(from);
821 raw_spin_unlock_irqrestore(&devtree_lock, flags);
822 return np;
823}
824EXPORT_SYMBOL(of_find_node_by_name);
825
826/**
827 * of_find_node_by_type - Find a node by its "device_type" property
828 * @from: The node to start searching from, or NULL to start searching
829 * the entire device tree. The node you pass will not be
830 * searched, only the next one will; typically, you pass
831 * what the previous call returned. of_node_put() will be
832 * called on from for you.
833 * @type: The type string to match against
834 *
835 * Returns a node pointer with refcount incremented, use
836 * of_node_put() on it when done.
837 */
838struct device_node *of_find_node_by_type(struct device_node *from,
839 const char *type)
840{
841 struct device_node *np;
842 unsigned long flags;
843
844 raw_spin_lock_irqsave(&devtree_lock, flags);
845 np = from ? from->allnext : of_allnodes;
846 for (; np; np = np->allnext)
847 if (np->type && (of_node_cmp(np->type, type) == 0)
848 && of_node_get(np))
849 break;
850 of_node_put(from);
851 raw_spin_unlock_irqrestore(&devtree_lock, flags);
852 return np;
853}
854EXPORT_SYMBOL(of_find_node_by_type);
855
856/**
857 * of_find_compatible_node - Find a node based on type and one of the
858 * tokens in its "compatible" property
859 * @from: The node to start searching from or NULL, the node
860 * you pass will not be searched, only the next one
861 * will; typically, you pass what the previous call
862 * returned. of_node_put() will be called on it
863 * @type: The type string to match "device_type" or NULL to ignore
864 * @compatible: The string to match to one of the tokens in the device
865 * "compatible" list.
866 *
867 * Returns a node pointer with refcount incremented, use
868 * of_node_put() on it when done.
869 */
870struct device_node *of_find_compatible_node(struct device_node *from,
871 const char *type, const char *compatible)
872{
873 struct device_node *np;
874 unsigned long flags;
875
876 raw_spin_lock_irqsave(&devtree_lock, flags);
877 np = from ? from->allnext : of_allnodes;
878 for (; np; np = np->allnext) {
879 if (__of_device_is_compatible(np, compatible, type, NULL) &&
880 of_node_get(np))
881 break;
882 }
883 of_node_put(from);
884 raw_spin_unlock_irqrestore(&devtree_lock, flags);
885 return np;
886}
887EXPORT_SYMBOL(of_find_compatible_node);
888
889/**
890 * of_find_node_with_property - Find a node which has a property with
891 * the given name.
892 * @from: The node to start searching from or NULL, the node
893 * you pass will not be searched, only the next one
894 * will; typically, you pass what the previous call
895 * returned. of_node_put() will be called on it
896 * @prop_name: The name of the property to look for.
897 *
898 * Returns a node pointer with refcount incremented, use
899 * of_node_put() on it when done.
900 */
901struct device_node *of_find_node_with_property(struct device_node *from,
902 const char *prop_name)
903{
904 struct device_node *np;
905 struct property *pp;
906 unsigned long flags;
907
908 raw_spin_lock_irqsave(&devtree_lock, flags);
909 np = from ? from->allnext : of_allnodes;
910 for (; np; np = np->allnext) {
911 for (pp = np->properties; pp; pp = pp->next) {
912 if (of_prop_cmp(pp->name, prop_name) == 0) {
913 of_node_get(np);
914 goto out;
915 }
916 }
917 }
918out:
919 of_node_put(from);
920 raw_spin_unlock_irqrestore(&devtree_lock, flags);
921 return np;
922}
923EXPORT_SYMBOL(of_find_node_with_property);
924
925static
926const struct of_device_id *__of_match_node(const struct of_device_id *matches,
927 const struct device_node *node)
928{
929 const struct of_device_id *best_match = NULL;
930 int score, best_score = 0;
931
932 if (!matches)
933 return NULL;
934
935 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
936 score = __of_device_is_compatible(node, matches->compatible,
937 matches->type, matches->name);
938 if (score > best_score) {
939 best_match = matches;
940 best_score = score;
941 }
942 }
943
944 return best_match;
945}
946
947/**
948 * of_match_node - Tell if an device_node has a matching of_match structure
949 * @matches: array of of device match structures to search in
950 * @node: the of device structure to match against
951 *
952 * Low level utility function used by device matching.
953 */
954const struct of_device_id *of_match_node(const struct of_device_id *matches,
955 const struct device_node *node)
956{
957 const struct of_device_id *match;
958 unsigned long flags;
959
960 raw_spin_lock_irqsave(&devtree_lock, flags);
961 match = __of_match_node(matches, node);
962 raw_spin_unlock_irqrestore(&devtree_lock, flags);
963 return match;
964}
965EXPORT_SYMBOL(of_match_node);
966
967/**
968 * of_find_matching_node_and_match - Find a node based on an of_device_id
969 * match table.
970 * @from: The node to start searching from or NULL, the node
971 * you pass will not be searched, only the next one
972 * will; typically, you pass what the previous call
973 * returned. of_node_put() will be called on it
974 * @matches: array of of device match structures to search in
975 * @match Updated to point at the matches entry which matched
976 *
977 * Returns a node pointer with refcount incremented, use
978 * of_node_put() on it when done.
979 */
980struct device_node *of_find_matching_node_and_match(struct device_node *from,
981 const struct of_device_id *matches,
982 const struct of_device_id **match)
983{
984 struct device_node *np;
985 const struct of_device_id *m;
986 unsigned long flags;
987
988 if (match)
989 *match = NULL;
990
991 raw_spin_lock_irqsave(&devtree_lock, flags);
992 np = from ? from->allnext : of_allnodes;
993 for (; np; np = np->allnext) {
994 m = __of_match_node(matches, np);
995 if (m && of_node_get(np)) {
996 if (match)
997 *match = m;
998 break;
999 }
1000 }
1001 of_node_put(from);
1002 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1003 return np;
1004}
1005EXPORT_SYMBOL(of_find_matching_node_and_match);
1006
1007/**
1008 * of_modalias_node - Lookup appropriate modalias for a device node
1009 * @node: pointer to a device tree node
1010 * @modalias: Pointer to buffer that modalias value will be copied into
1011 * @len: Length of modalias value
1012 *
1013 * Based on the value of the compatible property, this routine will attempt
1014 * to choose an appropriate modalias value for a particular device tree node.
1015 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1016 * from the first entry in the compatible list property.
1017 *
1018 * This routine returns 0 on success, <0 on failure.
1019 */
1020int of_modalias_node(struct device_node *node, char *modalias, int len)
1021{
1022 const char *compatible, *p;
1023 int cplen;
1024
1025 compatible = of_get_property(node, "compatible", &cplen);
1026 if (!compatible || strlen(compatible) > cplen)
1027 return -ENODEV;
1028 p = strchr(compatible, ',');
1029 strlcpy(modalias, p ? p + 1 : compatible, len);
1030 return 0;
1031}
1032EXPORT_SYMBOL_GPL(of_modalias_node);
1033
1034/**
1035 * of_find_node_by_phandle - Find a node given a phandle
1036 * @handle: phandle of the node to find
1037 *
1038 * Returns a node pointer with refcount incremented, use
1039 * of_node_put() on it when done.
1040 */
1041struct device_node *of_find_node_by_phandle(phandle handle)
1042{
1043 struct device_node *np;
1044 unsigned long flags;
1045
1046 raw_spin_lock_irqsave(&devtree_lock, flags);
1047 for (np = of_allnodes; np; np = np->allnext)
1048 if (np->phandle == handle)
1049 break;
1050 of_node_get(np);
1051 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1052 return np;
1053}
1054EXPORT_SYMBOL(of_find_node_by_phandle);
1055
1056/**
1057 * of_property_count_elems_of_size - Count the number of elements in a property
1058 *
1059 * @np: device node from which the property value is to be read.
1060 * @propname: name of the property to be searched.
1061 * @elem_size: size of the individual element
1062 *
1063 * Search for a property in a device node and count the number of elements of
1064 * size elem_size in it. Returns number of elements on sucess, -EINVAL if the
1065 * property does not exist or its length does not match a multiple of elem_size
1066 * and -ENODATA if the property does not have a value.
1067 */
1068int of_property_count_elems_of_size(const struct device_node *np,
1069 const char *propname, int elem_size)
1070{
1071 struct property *prop = of_find_property(np, propname, NULL);
1072
1073 if (!prop)
1074 return -EINVAL;
1075 if (!prop->value)
1076 return -ENODATA;
1077
1078 if (prop->length % elem_size != 0) {
1079 pr_err("size of %s in node %s is not a multiple of %d\n",
1080 propname, np->full_name, elem_size);
1081 return -EINVAL;
1082 }
1083
1084 return prop->length / elem_size;
1085}
1086EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
1087
1088/**
1089 * of_find_property_value_of_size
1090 *
1091 * @np: device node from which the property value is to be read.
1092 * @propname: name of the property to be searched.
1093 * @len: requested length of property value
1094 *
1095 * Search for a property in a device node and valid the requested size.
1096 * Returns the property value on success, -EINVAL if the property does not
1097 * exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
1098 * property data isn't large enough.
1099 *
1100 */
1101static void *of_find_property_value_of_size(const struct device_node *np,
1102 const char *propname, u32 len)
1103{
1104 struct property *prop = of_find_property(np, propname, NULL);
1105
1106 if (!prop)
1107 return ERR_PTR(-EINVAL);
1108 if (!prop->value)
1109 return ERR_PTR(-ENODATA);
1110 if (len > prop->length)
1111 return ERR_PTR(-EOVERFLOW);
1112
1113 return prop->value;
1114}
1115
1116/**
1117 * of_property_read_u32_index - Find and read a u32 from a multi-value property.
1118 *
1119 * @np: device node from which the property value is to be read.
1120 * @propname: name of the property to be searched.
1121 * @index: index of the u32 in the list of values
1122 * @out_value: pointer to return value, modified only if no error.
1123 *
1124 * Search for a property in a device node and read nth 32-bit value from
1125 * it. Returns 0 on success, -EINVAL if the property does not exist,
1126 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1127 * property data isn't large enough.
1128 *
1129 * The out_value is modified only if a valid u32 value can be decoded.
1130 */
1131int of_property_read_u32_index(const struct device_node *np,
1132 const char *propname,
1133 u32 index, u32 *out_value)
1134{
1135 const u32 *val = of_find_property_value_of_size(np, propname,
1136 ((index + 1) * sizeof(*out_value)));
1137
1138 if (IS_ERR(val))
1139 return PTR_ERR(val);
1140
1141 *out_value = be32_to_cpup(((__be32 *)val) + index);
1142 return 0;
1143}
1144EXPORT_SYMBOL_GPL(of_property_read_u32_index);
1145
1146/**
1147 * of_property_read_u8_array - Find and read an array of u8 from a property.
1148 *
1149 * @np: device node from which the property value is to be read.
1150 * @propname: name of the property to be searched.
1151 * @out_values: pointer to return value, modified only if return value is 0.
1152 * @sz: number of array elements to read
1153 *
1154 * Search for a property in a device node and read 8-bit value(s) from
1155 * it. Returns 0 on success, -EINVAL if the property does not exist,
1156 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1157 * property data isn't large enough.
1158 *
1159 * dts entry of array should be like:
1160 * property = /bits/ 8 <0x50 0x60 0x70>;
1161 *
1162 * The out_values is modified only if a valid u8 value can be decoded.
1163 */
1164int of_property_read_u8_array(const struct device_node *np,
1165 const char *propname, u8 *out_values, size_t sz)
1166{
1167 const u8 *val = of_find_property_value_of_size(np, propname,
1168 (sz * sizeof(*out_values)));
1169
1170 if (IS_ERR(val))
1171 return PTR_ERR(val);
1172
1173 while (sz--)
1174 *out_values++ = *val++;
1175 return 0;
1176}
1177EXPORT_SYMBOL_GPL(of_property_read_u8_array);
1178
1179/**
1180 * of_property_read_u16_array - Find and read an array of u16 from a property.
1181 *
1182 * @np: device node from which the property value is to be read.
1183 * @propname: name of the property to be searched.
1184 * @out_values: pointer to return value, modified only if return value is 0.
1185 * @sz: number of array elements to read
1186 *
1187 * Search for a property in a device node and read 16-bit value(s) from
1188 * it. Returns 0 on success, -EINVAL if the property does not exist,
1189 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1190 * property data isn't large enough.
1191 *
1192 * dts entry of array should be like:
1193 * property = /bits/ 16 <0x5000 0x6000 0x7000>;
1194 *
1195 * The out_values is modified only if a valid u16 value can be decoded.
1196 */
1197int of_property_read_u16_array(const struct device_node *np,
1198 const char *propname, u16 *out_values, size_t sz)
1199{
1200 const __be16 *val = of_find_property_value_of_size(np, propname,
1201 (sz * sizeof(*out_values)));
1202
1203 if (IS_ERR(val))
1204 return PTR_ERR(val);
1205
1206 while (sz--)
1207 *out_values++ = be16_to_cpup(val++);
1208 return 0;
1209}
1210EXPORT_SYMBOL_GPL(of_property_read_u16_array);
1211
1212/**
1213 * of_property_read_u32_array - Find and read an array of 32 bit integers
1214 * from a property.
1215 *
1216 * @np: device node from which the property value is to be read.
1217 * @propname: name of the property to be searched.
1218 * @out_values: pointer to return value, modified only if return value is 0.
1219 * @sz: number of array elements to read
1220 *
1221 * Search for a property in a device node and read 32-bit value(s) from
1222 * it. Returns 0 on success, -EINVAL if the property does not exist,
1223 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1224 * property data isn't large enough.
1225 *
1226 * The out_values is modified only if a valid u32 value can be decoded.
1227 */
1228int of_property_read_u32_array(const struct device_node *np,
1229 const char *propname, u32 *out_values,
1230 size_t sz)
1231{
1232 const __be32 *val = of_find_property_value_of_size(np, propname,
1233 (sz * sizeof(*out_values)));
1234
1235 if (IS_ERR(val))
1236 return PTR_ERR(val);
1237
1238 while (sz--)
1239 *out_values++ = be32_to_cpup(val++);
1240 return 0;
1241}
1242EXPORT_SYMBOL_GPL(of_property_read_u32_array);
1243
1244/**
1245 * of_property_read_u64 - Find and read a 64 bit integer from a property
1246 * @np: device node from which the property value is to be read.
1247 * @propname: name of the property to be searched.
1248 * @out_value: pointer to return value, modified only if return value is 0.
1249 *
1250 * Search for a property in a device node and read a 64-bit value from
1251 * it. Returns 0 on success, -EINVAL if the property does not exist,
1252 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1253 * property data isn't large enough.
1254 *
1255 * The out_value is modified only if a valid u64 value can be decoded.
1256 */
1257int of_property_read_u64(const struct device_node *np, const char *propname,
1258 u64 *out_value)
1259{
1260 const __be32 *val = of_find_property_value_of_size(np, propname,
1261 sizeof(*out_value));
1262
1263 if (IS_ERR(val))
1264 return PTR_ERR(val);
1265
1266 *out_value = of_read_number(val, 2);
1267 return 0;
1268}
1269EXPORT_SYMBOL_GPL(of_property_read_u64);
1270
1271/**
1272 * of_property_read_string - Find and read a string from a property
1273 * @np: device node from which the property value is to be read.
1274 * @propname: name of the property to be searched.
1275 * @out_string: pointer to null terminated return string, modified only if
1276 * return value is 0.
1277 *
1278 * Search for a property in a device tree node and retrieve a null
1279 * terminated string value (pointer to data, not a copy). Returns 0 on
1280 * success, -EINVAL if the property does not exist, -ENODATA if property
1281 * does not have a value, and -EILSEQ if the string is not null-terminated
1282 * within the length of the property data.
1283 *
1284 * The out_string pointer is modified only if a valid string can be decoded.
1285 */
1286int of_property_read_string(struct device_node *np, const char *propname,
1287 const char **out_string)
1288{
1289 struct property *prop = of_find_property(np, propname, NULL);
1290 if (!prop)
1291 return -EINVAL;
1292 if (!prop->value)
1293 return -ENODATA;
1294 if (strnlen(prop->value, prop->length) >= prop->length)
1295 return -EILSEQ;
1296 *out_string = prop->value;
1297 return 0;
1298}
1299EXPORT_SYMBOL_GPL(of_property_read_string);
1300
1301/**
1302 * of_property_read_string_index - Find and read a string from a multiple
1303 * strings property.
1304 * @np: device node from which the property value is to be read.
1305 * @propname: name of the property to be searched.
1306 * @index: index of the string in the list of strings
1307 * @out_string: pointer to null terminated return string, modified only if
1308 * return value is 0.
1309 *
1310 * Search for a property in a device tree node and retrieve a null
1311 * terminated string value (pointer to data, not a copy) in the list of strings
1312 * contained in that property.
1313 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
1314 * property does not have a value, and -EILSEQ if the string is not
1315 * null-terminated within the length of the property data.
1316 *
1317 * The out_string pointer is modified only if a valid string can be decoded.
1318 */
1319int of_property_read_string_index(struct device_node *np, const char *propname,
1320 int index, const char **output)
1321{
1322 struct property *prop = of_find_property(np, propname, NULL);
1323 int i = 0;
1324 size_t l = 0, total = 0;
1325 const char *p;
1326
1327 if (!prop)
1328 return -EINVAL;
1329 if (!prop->value)
1330 return -ENODATA;
1331 if (strnlen(prop->value, prop->length) >= prop->length)
1332 return -EILSEQ;
1333
1334 p = prop->value;
1335
1336 for (i = 0; total < prop->length; total += l, p += l) {
1337 l = strlen(p) + 1;
1338 if (i++ == index) {
1339 *output = p;
1340 return 0;
1341 }
1342 }
1343 return -ENODATA;
1344}
1345EXPORT_SYMBOL_GPL(of_property_read_string_index);
1346
1347/**
1348 * of_property_match_string() - Find string in a list and return index
1349 * @np: pointer to node containing string list property
1350 * @propname: string list property name
1351 * @string: pointer to string to search for in string list
1352 *
1353 * This function searches a string list property and returns the index
1354 * of a specific string value.
1355 */
1356int of_property_match_string(struct device_node *np, const char *propname,
1357 const char *string)
1358{
1359 struct property *prop = of_find_property(np, propname, NULL);
1360 size_t l;
1361 int i;
1362 const char *p, *end;
1363
1364 if (!prop)
1365 return -EINVAL;
1366 if (!prop->value)
1367 return -ENODATA;
1368
1369 p = prop->value;
1370 end = p + prop->length;
1371
1372 for (i = 0; p < end; i++, p += l) {
1373 l = strlen(p) + 1;
1374 if (p + l > end)
1375 return -EILSEQ;
1376 pr_debug("comparing %s with %s\n", string, p);
1377 if (strcmp(string, p) == 0)
1378 return i; /* Found it; return index */
1379 }
1380 return -ENODATA;
1381}
1382EXPORT_SYMBOL_GPL(of_property_match_string);
1383
1384/**
1385 * of_property_count_strings - Find and return the number of strings from a
1386 * multiple strings property.
1387 * @np: device node from which the property value is to be read.
1388 * @propname: name of the property to be searched.
1389 *
1390 * Search for a property in a device tree node and retrieve the number of null
1391 * terminated string contain in it. Returns the number of strings on
1392 * success, -EINVAL if the property does not exist, -ENODATA if property
1393 * does not have a value, and -EILSEQ if the string is not null-terminated
1394 * within the length of the property data.
1395 */
1396int of_property_count_strings(struct device_node *np, const char *propname)
1397{
1398 struct property *prop = of_find_property(np, propname, NULL);
1399 int i = 0;
1400 size_t l = 0, total = 0;
1401 const char *p;
1402
1403 if (!prop)
1404 return -EINVAL;
1405 if (!prop->value)
1406 return -ENODATA;
1407 if (strnlen(prop->value, prop->length) >= prop->length)
1408 return -EILSEQ;
1409
1410 p = prop->value;
1411
1412 for (i = 0; total < prop->length; total += l, p += l, i++)
1413 l = strlen(p) + 1;
1414
1415 return i;
1416}
1417EXPORT_SYMBOL_GPL(of_property_count_strings);
1418
1419void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1420{
1421 int i;
1422 printk("%s %s", msg, of_node_full_name(args->np));
1423 for (i = 0; i < args->args_count; i++)
1424 printk(i ? ",%08x" : ":%08x", args->args[i]);
1425 printk("\n");
1426}
1427
1428static int __of_parse_phandle_with_args(const struct device_node *np,
1429 const char *list_name,
1430 const char *cells_name,
1431 int cell_count, int index,
1432 struct of_phandle_args *out_args)
1433{
1434 const __be32 *list, *list_end;
1435 int rc = 0, size, cur_index = 0;
1436 uint32_t count = 0;
1437 struct device_node *node = NULL;
1438 phandle phandle;
1439
1440 /* Retrieve the phandle list property */
1441 list = of_get_property(np, list_name, &size);
1442 if (!list)
1443 return -ENOENT;
1444 list_end = list + size / sizeof(*list);
1445
1446 /* Loop over the phandles until all the requested entry is found */
1447 while (list < list_end) {
1448 rc = -EINVAL;
1449 count = 0;
1450
1451 /*
1452 * If phandle is 0, then it is an empty entry with no
1453 * arguments. Skip forward to the next entry.
1454 */
1455 phandle = be32_to_cpup(list++);
1456 if (phandle) {
1457 /*
1458 * Find the provider node and parse the #*-cells
1459 * property to determine the argument length.
1460 *
1461 * This is not needed if the cell count is hard-coded
1462 * (i.e. cells_name not set, but cell_count is set),
1463 * except when we're going to return the found node
1464 * below.
1465 */
1466 if (cells_name || cur_index == index) {
1467 node = of_find_node_by_phandle(phandle);
1468 if (!node) {
1469 pr_err("%s: could not find phandle\n",
1470 np->full_name);
1471 goto err;
1472 }
1473 }
1474
1475 if (cells_name) {
1476 if (of_property_read_u32(node, cells_name,
1477 &count)) {
1478 pr_err("%s: could not get %s for %s\n",
1479 np->full_name, cells_name,
1480 node->full_name);
1481 goto err;
1482 }
1483 } else {
1484 count = cell_count;
1485 }
1486
1487 /*
1488 * Make sure that the arguments actually fit in the
1489 * remaining property data length
1490 */
1491 if (list + count > list_end) {
1492 pr_err("%s: arguments longer than property\n",
1493 np->full_name);
1494 goto err;
1495 }
1496 }
1497
1498 /*
1499 * All of the error cases above bail out of the loop, so at
1500 * this point, the parsing is successful. If the requested
1501 * index matches, then fill the out_args structure and return,
1502 * or return -ENOENT for an empty entry.
1503 */
1504 rc = -ENOENT;
1505 if (cur_index == index) {
1506 if (!phandle)
1507 goto err;
1508
1509 if (out_args) {
1510 int i;
1511 if (WARN_ON(count > MAX_PHANDLE_ARGS))
1512 count = MAX_PHANDLE_ARGS;
1513 out_args->np = node;
1514 out_args->args_count = count;
1515 for (i = 0; i < count; i++)
1516 out_args->args[i] = be32_to_cpup(list++);
1517 } else {
1518 of_node_put(node);
1519 }
1520
1521 /* Found it! return success */
1522 return 0;
1523 }
1524
1525 of_node_put(node);
1526 node = NULL;
1527 list += count;
1528 cur_index++;
1529 }
1530
1531 /*
1532 * Unlock node before returning result; will be one of:
1533 * -ENOENT : index is for empty phandle
1534 * -EINVAL : parsing error on data
1535 * [1..n] : Number of phandle (count mode; when index = -1)
1536 */
1537 rc = index < 0 ? cur_index : -ENOENT;
1538 err:
1539 if (node)
1540 of_node_put(node);
1541 return rc;
1542}
1543
1544/**
1545 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1546 * @np: Pointer to device node holding phandle property
1547 * @phandle_name: Name of property holding a phandle value
1548 * @index: For properties holding a table of phandles, this is the index into
1549 * the table
1550 *
1551 * Returns the device_node pointer with refcount incremented. Use
1552 * of_node_put() on it when done.
1553 */
1554struct device_node *of_parse_phandle(const struct device_node *np,
1555 const char *phandle_name, int index)
1556{
1557 struct of_phandle_args args;
1558
1559 if (index < 0)
1560 return NULL;
1561
1562 if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1563 index, &args))
1564 return NULL;
1565
1566 return args.np;
1567}
1568EXPORT_SYMBOL(of_parse_phandle);
1569
1570/**
1571 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1572 * @np: pointer to a device tree node containing a list
1573 * @list_name: property name that contains a list
1574 * @cells_name: property name that specifies phandles' arguments count
1575 * @index: index of a phandle to parse out
1576 * @out_args: optional pointer to output arguments structure (will be filled)
1577 *
1578 * This function is useful to parse lists of phandles and their arguments.
1579 * Returns 0 on success and fills out_args, on error returns appropriate
1580 * errno value.
1581 *
1582 * Caller is responsible to call of_node_put() on the returned out_args->node
1583 * pointer.
1584 *
1585 * Example:
1586 *
1587 * phandle1: node1 {
1588 * #list-cells = <2>;
1589 * }
1590 *
1591 * phandle2: node2 {
1592 * #list-cells = <1>;
1593 * }
1594 *
1595 * node3 {
1596 * list = <&phandle1 1 2 &phandle2 3>;
1597 * }
1598 *
1599 * To get a device_node of the `node2' node you may call this:
1600 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1601 */
1602int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1603 const char *cells_name, int index,
1604 struct of_phandle_args *out_args)
1605{
1606 if (index < 0)
1607 return -EINVAL;
1608 return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
1609 index, out_args);
1610}
1611EXPORT_SYMBOL(of_parse_phandle_with_args);
1612
1613/**
1614 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1615 * @np: pointer to a device tree node containing a list
1616 * @list_name: property name that contains a list
1617 * @cell_count: number of argument cells following the phandle
1618 * @index: index of a phandle to parse out
1619 * @out_args: optional pointer to output arguments structure (will be filled)
1620 *
1621 * This function is useful to parse lists of phandles and their arguments.
1622 * Returns 0 on success and fills out_args, on error returns appropriate
1623 * errno value.
1624 *
1625 * Caller is responsible to call of_node_put() on the returned out_args->node
1626 * pointer.
1627 *
1628 * Example:
1629 *
1630 * phandle1: node1 {
1631 * }
1632 *
1633 * phandle2: node2 {
1634 * }
1635 *
1636 * node3 {
1637 * list = <&phandle1 0 2 &phandle2 2 3>;
1638 * }
1639 *
1640 * To get a device_node of the `node2' node you may call this:
1641 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1642 */
1643int of_parse_phandle_with_fixed_args(const struct device_node *np,
1644 const char *list_name, int cell_count,
1645 int index, struct of_phandle_args *out_args)
1646{
1647 if (index < 0)
1648 return -EINVAL;
1649 return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1650 index, out_args);
1651}
1652EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1653
1654/**
1655 * of_count_phandle_with_args() - Find the number of phandles references in a property
1656 * @np: pointer to a device tree node containing a list
1657 * @list_name: property name that contains a list
1658 * @cells_name: property name that specifies phandles' arguments count
1659 *
1660 * Returns the number of phandle + argument tuples within a property. It
1661 * is a typical pattern to encode a list of phandle and variable
1662 * arguments into a single property. The number of arguments is encoded
1663 * by a property in the phandle-target node. For example, a gpios
1664 * property would contain a list of GPIO specifies consisting of a
1665 * phandle and 1 or more arguments. The number of arguments are
1666 * determined by the #gpio-cells property in the node pointed to by the
1667 * phandle.
1668 */
1669int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1670 const char *cells_name)
1671{
1672 return __of_parse_phandle_with_args(np, list_name, cells_name, 0, -1,
1673 NULL);
1674}
1675EXPORT_SYMBOL(of_count_phandle_with_args);
1676
1677#if defined(CONFIG_OF_DYNAMIC)
1678static int of_property_notify(int action, struct device_node *np,
1679 struct property *prop)
1680{
1681 struct of_prop_reconfig pr;
1682
1683 /* only call notifiers if the node is attached */
1684 if (!of_node_is_attached(np))
1685 return 0;
1686
1687 pr.dn = np;
1688 pr.prop = prop;
1689 return of_reconfig_notify(action, &pr);
1690}
1691#else
1692static int of_property_notify(int action, struct device_node *np,
1693 struct property *prop)
1694{
1695 return 0;
1696}
1697#endif
1698
1699/**
1700 * __of_add_property - Add a property to a node without lock operations
1701 */
1702static int __of_add_property(struct device_node *np, struct property *prop)
1703{
1704 struct property **next;
1705
1706 prop->next = NULL;
1707 next = &np->properties;
1708 while (*next) {
1709 if (strcmp(prop->name, (*next)->name) == 0)
1710 /* duplicate ! don't insert it */
1711 return -EEXIST;
1712
1713 next = &(*next)->next;
1714 }
1715 *next = prop;
1716
1717 return 0;
1718}
1719
1720/**
1721 * of_add_property - Add a property to a node
1722 */
1723int of_add_property(struct device_node *np, struct property *prop)
1724{
1725 unsigned long flags;
1726 int rc;
1727
1728 rc = of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop);
1729 if (rc)
1730 return rc;
1731
1732 raw_spin_lock_irqsave(&devtree_lock, flags);
1733 rc = __of_add_property(np, prop);
1734 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1735 if (rc)
1736 return rc;
1737
1738 if (of_node_is_attached(np))
1739 __of_add_property_sysfs(np, prop);
1740
1741 return rc;
1742}
1743
1744/**
1745 * of_remove_property - Remove a property from a node.
1746 *
1747 * Note that we don't actually remove it, since we have given out
1748 * who-knows-how-many pointers to the data using get-property.
1749 * Instead we just move the property to the "dead properties"
1750 * list, so it won't be found any more.
1751 */
1752int of_remove_property(struct device_node *np, struct property *prop)
1753{
1754 struct property **next;
1755 unsigned long flags;
1756 int found = 0;
1757 int rc;
1758
1759 rc = of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop);
1760 if (rc)
1761 return rc;
1762
1763 raw_spin_lock_irqsave(&devtree_lock, flags);
1764 next = &np->properties;
1765 while (*next) {
1766 if (*next == prop) {
1767 /* found the node */
1768 *next = prop->next;
1769 prop->next = np->deadprops;
1770 np->deadprops = prop;
1771 found = 1;
1772 break;
1773 }
1774 next = &(*next)->next;
1775 }
1776 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1777
1778 if (!found)
1779 return -ENODEV;
1780
1781 /* at early boot, bail hear and defer setup to of_init() */
1782 if (!of_kset)
1783 return 0;
1784
1785 sysfs_remove_bin_file(&np->kobj, &prop->attr);
1786
1787 return 0;
1788}
1789
1790/*
1791 * of_update_property - Update a property in a node, if the property does
1792 * not exist, add it.
1793 *
1794 * Note that we don't actually remove it, since we have given out
1795 * who-knows-how-many pointers to the data using get-property.
1796 * Instead we just move the property to the "dead properties" list,
1797 * and add the new property to the property list
1798 */
1799int of_update_property(struct device_node *np, struct property *newprop)
1800{
1801 struct property **next, *oldprop;
1802 unsigned long flags;
1803 int rc, found = 0;
1804
1805 rc = of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop);
1806 if (rc)
1807 return rc;
1808
1809 if (!newprop->name)
1810 return -EINVAL;
1811
1812 oldprop = of_find_property(np, newprop->name, NULL);
1813 if (!oldprop)
1814 return of_add_property(np, newprop);
1815
1816 raw_spin_lock_irqsave(&devtree_lock, flags);
1817 next = &np->properties;
1818 while (*next) {
1819 if (*next == oldprop) {
1820 /* found the node */
1821 newprop->next = oldprop->next;
1822 *next = newprop;
1823 oldprop->next = np->deadprops;
1824 np->deadprops = oldprop;
1825 found = 1;
1826 break;
1827 }
1828 next = &(*next)->next;
1829 }
1830 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1831 if (!found)
1832 return -ENODEV;
1833
1834 /* At early boot, bail out and defer setup to of_init() */
1835 if (!of_kset)
1836 return found ? 0 : -ENODEV;
1837
1838 /* Update the sysfs attribute */
1839 sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
1840 __of_add_property_sysfs(np, newprop);
1841
1842 return 0;
1843}
1844
1845#if defined(CONFIG_OF_DYNAMIC)
1846/*
1847 * Support for dynamic device trees.
1848 *
1849 * On some platforms, the device tree can be manipulated at runtime.
1850 * The routines in this section support adding, removing and changing
1851 * device tree nodes.
1852 */
1853
1854static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain);
1855
1856int of_reconfig_notifier_register(struct notifier_block *nb)
1857{
1858 return blocking_notifier_chain_register(&of_reconfig_chain, nb);
1859}
1860EXPORT_SYMBOL_GPL(of_reconfig_notifier_register);
1861
1862int of_reconfig_notifier_unregister(struct notifier_block *nb)
1863{
1864 return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
1865}
1866EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);
1867
1868int of_reconfig_notify(unsigned long action, void *p)
1869{
1870 int rc;
1871
1872 rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
1873 return notifier_to_errno(rc);
1874}
1875
1876/**
1877 * of_attach_node - Plug a device node into the tree and global list.
1878 */
1879int of_attach_node(struct device_node *np)
1880{
1881 unsigned long flags;
1882 int rc;
1883
1884 rc = of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, np);
1885 if (rc)
1886 return rc;
1887
1888 raw_spin_lock_irqsave(&devtree_lock, flags);
1889 np->sibling = np->parent->child;
1890 np->allnext = of_allnodes;
1891 np->parent->child = np;
1892 of_allnodes = np;
1893 of_node_clear_flag(np, OF_DETACHED);
1894 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1895
1896 of_node_add(np);
1897 return 0;
1898}
1899
1900/**
1901 * of_detach_node - "Unplug" a node from the device tree.
1902 *
1903 * The caller must hold a reference to the node. The memory associated with
1904 * the node is not freed until its refcount goes to zero.
1905 */
1906int of_detach_node(struct device_node *np)
1907{
1908 struct device_node *parent;
1909 unsigned long flags;
1910 int rc = 0;
1911
1912 rc = of_reconfig_notify(OF_RECONFIG_DETACH_NODE, np);
1913 if (rc)
1914 return rc;
1915
1916 raw_spin_lock_irqsave(&devtree_lock, flags);
1917
1918 if (of_node_check_flag(np, OF_DETACHED)) {
1919 /* someone already detached it */
1920 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1921 return rc;
1922 }
1923
1924 parent = np->parent;
1925 if (!parent) {
1926 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1927 return rc;
1928 }
1929
1930 if (of_allnodes == np)
1931 of_allnodes = np->allnext;
1932 else {
1933 struct device_node *prev;
1934 for (prev = of_allnodes;
1935 prev->allnext != np;
1936 prev = prev->allnext)
1937 ;
1938 prev->allnext = np->allnext;
1939 }
1940
1941 if (parent->child == np)
1942 parent->child = np->sibling;
1943 else {
1944 struct device_node *prevsib;
1945 for (prevsib = np->parent->child;
1946 prevsib->sibling != np;
1947 prevsib = prevsib->sibling)
1948 ;
1949 prevsib->sibling = np->sibling;
1950 }
1951
1952 of_node_set_flag(np, OF_DETACHED);
1953 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1954
1955 of_node_remove(np);
1956 return rc;
1957}
1958#endif /* defined(CONFIG_OF_DYNAMIC) */
1959
1960static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1961 int id, const char *stem, int stem_len)
1962{
1963 ap->np = np;
1964 ap->id = id;
1965 strncpy(ap->stem, stem, stem_len);
1966 ap->stem[stem_len] = 0;
1967 list_add_tail(&ap->link, &aliases_lookup);
1968 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
1969 ap->alias, ap->stem, ap->id, of_node_full_name(np));
1970}
1971
1972/**
1973 * of_alias_scan - Scan all properties of 'aliases' node
1974 *
1975 * The function scans all the properties of 'aliases' node and populate
1976 * the the global lookup table with the properties. It returns the
1977 * number of alias_prop found, or error code in error case.
1978 *
1979 * @dt_alloc: An allocator that provides a virtual address to memory
1980 * for the resulting tree
1981 */
1982void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1983{
1984 struct property *pp;
1985
1986 of_chosen = of_find_node_by_path("/chosen");
1987 if (of_chosen == NULL)
1988 of_chosen = of_find_node_by_path("/chosen@0");
1989
1990 if (of_chosen) {
1991 const char *name = of_get_property(of_chosen, "stdout-path", NULL);
1992 if (!name)
1993 name = of_get_property(of_chosen, "linux,stdout-path", NULL);
1994 if (name)
1995 of_stdout = of_find_node_by_path(name);
1996 }
1997
1998 of_aliases = of_find_node_by_path("/aliases");
1999 if (!of_aliases)
2000 return;
2001
2002 for_each_property_of_node(of_aliases, pp) {
2003 const char *start = pp->name;
2004 const char *end = start + strlen(start);
2005 struct device_node *np;
2006 struct alias_prop *ap;
2007 int id, len;
2008
2009 /* Skip those we do not want to proceed */
2010 if (!strcmp(pp->name, "name") ||
2011 !strcmp(pp->name, "phandle") ||
2012 !strcmp(pp->name, "linux,phandle"))
2013 continue;
2014
2015 np = of_find_node_by_path(pp->value);
2016 if (!np)
2017 continue;
2018
2019 /* walk the alias backwards to extract the id and work out
2020 * the 'stem' string */
2021 while (isdigit(*(end-1)) && end > start)
2022 end--;
2023 len = end - start;
2024
2025 if (kstrtoint(end, 10, &id) < 0)
2026 continue;
2027
2028 /* Allocate an alias_prop with enough space for the stem */
2029 ap = dt_alloc(sizeof(*ap) + len + 1, 4);
2030 if (!ap)
2031 continue;
2032 memset(ap, 0, sizeof(*ap) + len + 1);
2033 ap->alias = start;
2034 of_alias_add(ap, np, id, start, len);
2035 }
2036}
2037
2038/**
2039 * of_alias_get_id - Get alias id for the given device_node
2040 * @np: Pointer to the given device_node
2041 * @stem: Alias stem of the given device_node
2042 *
2043 * The function travels the lookup table to get alias id for the given
2044 * device_node and alias stem. It returns the alias id if find it.
2045 */
2046int of_alias_get_id(struct device_node *np, const char *stem)
2047{
2048 struct alias_prop *app;
2049 int id = -ENODEV;
2050
2051 mutex_lock(&of_aliases_mutex);
2052 list_for_each_entry(app, &aliases_lookup, link) {
2053 if (strcmp(app->stem, stem) != 0)
2054 continue;
2055
2056 if (np == app->np) {
2057 id = app->id;
2058 break;
2059 }
2060 }
2061 mutex_unlock(&of_aliases_mutex);
2062
2063 return id;
2064}
2065EXPORT_SYMBOL_GPL(of_alias_get_id);
2066
2067const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
2068 u32 *pu)
2069{
2070 const void *curv = cur;
2071
2072 if (!prop)
2073 return NULL;
2074
2075 if (!cur) {
2076 curv = prop->value;
2077 goto out_val;
2078 }
2079
2080 curv += sizeof(*cur);
2081 if (curv >= prop->value + prop->length)
2082 return NULL;
2083
2084out_val:
2085 *pu = be32_to_cpup(curv);
2086 return curv;
2087}
2088EXPORT_SYMBOL_GPL(of_prop_next_u32);
2089
2090const char *of_prop_next_string(struct property *prop, const char *cur)
2091{
2092 const void *curv = cur;
2093
2094 if (!prop)
2095 return NULL;
2096
2097 if (!cur)
2098 return prop->value;
2099
2100 curv += strlen(cur) + 1;
2101 if (curv >= prop->value + prop->length)
2102 return NULL;
2103
2104 return curv;
2105}
2106EXPORT_SYMBOL_GPL(of_prop_next_string);
2107
2108/**
2109 * of_device_is_stdout_path - check if a device node matches the
2110 * linux,stdout-path property
2111 *
2112 * Check if this device node matches the linux,stdout-path property
2113 * in the chosen node. return true if yes, false otherwise.
2114 */
2115int of_device_is_stdout_path(struct device_node *dn)
2116{
2117 if (!of_stdout)
2118 return false;
2119
2120 return of_stdout == dn;
2121}
2122EXPORT_SYMBOL_GPL(of_device_is_stdout_path);
2123
2124/**
2125 * of_find_next_cache_node - Find a node's subsidiary cache
2126 * @np: node of type "cpu" or "cache"
2127 *
2128 * Returns a node pointer with refcount incremented, use
2129 * of_node_put() on it when done. Caller should hold a reference
2130 * to np.
2131 */
2132struct device_node *of_find_next_cache_node(const struct device_node *np)
2133{
2134 struct device_node *child;
2135 const phandle *handle;
2136
2137 handle = of_get_property(np, "l2-cache", NULL);
2138 if (!handle)
2139 handle = of_get_property(np, "next-level-cache", NULL);
2140
2141 if (handle)
2142 return of_find_node_by_phandle(be32_to_cpup(handle));
2143
2144 /* OF on pmac has nodes instead of properties named "l2-cache"
2145 * beneath CPU nodes.
2146 */
2147 if (!strcmp(np->type, "cpu"))
2148 for_each_child_of_node(np, child)
2149 if (!strcmp(child->type, "cache"))
2150 return child;
2151
2152 return NULL;
2153}
2154
2155/**
2156 * of_graph_parse_endpoint() - parse common endpoint node properties
2157 * @node: pointer to endpoint device_node
2158 * @endpoint: pointer to the OF endpoint data structure
2159 *
2160 * The caller should hold a reference to @node.
2161 */
2162int of_graph_parse_endpoint(const struct device_node *node,
2163 struct of_endpoint *endpoint)
2164{
2165 struct device_node *port_node = of_get_parent(node);
2166
2167 WARN_ONCE(!port_node, "%s(): endpoint %s has no parent node\n",
2168 __func__, node->full_name);
2169
2170 memset(endpoint, 0, sizeof(*endpoint));
2171
2172 endpoint->local_node = node;
2173 /*
2174 * It doesn't matter whether the two calls below succeed.
2175 * If they don't then the default value 0 is used.
2176 */
2177 of_property_read_u32(port_node, "reg", &endpoint->port);
2178 of_property_read_u32(node, "reg", &endpoint->id);
2179
2180 of_node_put(port_node);
2181
2182 return 0;
2183}
2184EXPORT_SYMBOL(of_graph_parse_endpoint);
2185
2186/**
2187 * of_graph_get_next_endpoint() - get next endpoint node
2188 * @parent: pointer to the parent device node
2189 * @prev: previous endpoint node, or NULL to get first
2190 *
2191 * Return: An 'endpoint' node pointer with refcount incremented. Refcount
2192 * of the passed @prev node is not decremented, the caller have to use
2193 * of_node_put() on it when done.
2194 */
2195struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
2196 struct device_node *prev)
2197{
2198 struct device_node *endpoint;
2199 struct device_node *port;
2200
2201 if (!parent)
2202 return NULL;
2203
2204 /*
2205 * Start by locating the port node. If no previous endpoint is specified
2206 * search for the first port node, otherwise get the previous endpoint
2207 * parent port node.
2208 */
2209 if (!prev) {
2210 struct device_node *node;
2211
2212 node = of_get_child_by_name(parent, "ports");
2213 if (node)
2214 parent = node;
2215
2216 port = of_get_child_by_name(parent, "port");
2217 of_node_put(node);
2218
2219 if (!port) {
2220 pr_err("%s(): no port node found in %s\n",
2221 __func__, parent->full_name);
2222 return NULL;
2223 }
2224 } else {
2225 port = of_get_parent(prev);
2226 if (WARN_ONCE(!port, "%s(): endpoint %s has no parent node\n",
2227 __func__, prev->full_name))
2228 return NULL;
2229
2230 /*
2231 * Avoid dropping prev node refcount to 0 when getting the next
2232 * child below.
2233 */
2234 of_node_get(prev);
2235 }
2236
2237 while (1) {
2238 /*
2239 * Now that we have a port node, get the next endpoint by
2240 * getting the next child. If the previous endpoint is NULL this
2241 * will return the first child.
2242 */
2243 endpoint = of_get_next_child(port, prev);
2244 if (endpoint) {
2245 of_node_put(port);
2246 return endpoint;
2247 }
2248
2249 /* No more endpoints under this port, try the next one. */
2250 prev = NULL;
2251
2252 do {
2253 port = of_get_next_child(parent, port);
2254 if (!port)
2255 return NULL;
2256 } while (of_node_cmp(port->name, "port"));
2257 }
2258}
2259EXPORT_SYMBOL(of_graph_get_next_endpoint);
2260
2261/**
2262 * of_graph_get_remote_port_parent() - get remote port's parent node
2263 * @node: pointer to a local endpoint device_node
2264 *
2265 * Return: Remote device node associated with remote endpoint node linked
2266 * to @node. Use of_node_put() on it when done.
2267 */
2268struct device_node *of_graph_get_remote_port_parent(
2269 const struct device_node *node)
2270{
2271 struct device_node *np;
2272 unsigned int depth;
2273
2274 /* Get remote endpoint node. */
2275 np = of_parse_phandle(node, "remote-endpoint", 0);
2276
2277 /* Walk 3 levels up only if there is 'ports' node. */
2278 for (depth = 3; depth && np; depth--) {
2279 np = of_get_next_parent(np);
2280 if (depth == 2 && of_node_cmp(np->name, "ports"))
2281 break;
2282 }
2283 return np;
2284}
2285EXPORT_SYMBOL(of_graph_get_remote_port_parent);
2286
2287/**
2288 * of_graph_get_remote_port() - get remote port node
2289 * @node: pointer to a local endpoint device_node
2290 *
2291 * Return: Remote port node associated with remote endpoint node linked
2292 * to @node. Use of_node_put() on it when done.
2293 */
2294struct device_node *of_graph_get_remote_port(const struct device_node *node)
2295{
2296 struct device_node *np;
2297
2298 /* Get remote endpoint node. */
2299 np = of_parse_phandle(node, "remote-endpoint", 0);
2300 if (!np)
2301 return NULL;
2302 return of_get_next_parent(np);
2303}
2304EXPORT_SYMBOL(of_graph_get_remote_port);