Loading...
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Procedures for creating, accessing and interpreting the device tree.
4 *
5 * Paul Mackerras August 1996.
6 * Copyright (C) 1996-2005 Paul Mackerras.
7 *
8 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
9 * {engebret|bergner}@us.ibm.com
10 *
11 * Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
12 *
13 * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
14 * Grant Likely.
15 */
16
17#define pr_fmt(fmt) "OF: " fmt
18
19#include <linux/console.h>
20#include <linux/ctype.h>
21#include <linux/cpu.h>
22#include <linux/module.h>
23#include <linux/of.h>
24#include <linux/of_device.h>
25#include <linux/of_graph.h>
26#include <linux/spinlock.h>
27#include <linux/slab.h>
28#include <linux/string.h>
29#include <linux/proc_fs.h>
30
31#include "of_private.h"
32
33LIST_HEAD(aliases_lookup);
34
35struct device_node *of_root;
36EXPORT_SYMBOL(of_root);
37struct device_node *of_chosen;
38EXPORT_SYMBOL(of_chosen);
39struct device_node *of_aliases;
40struct device_node *of_stdout;
41static const char *of_stdout_options;
42
43struct kset *of_kset;
44
45/*
46 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
47 * This mutex must be held whenever modifications are being made to the
48 * device tree. The of_{attach,detach}_node() and
49 * of_{add,remove,update}_property() helpers make sure this happens.
50 */
51DEFINE_MUTEX(of_mutex);
52
53/* use when traversing tree through the child, sibling,
54 * or parent members of struct device_node.
55 */
56DEFINE_RAW_SPINLOCK(devtree_lock);
57
58bool of_node_name_eq(const struct device_node *np, const char *name)
59{
60 const char *node_name;
61 size_t len;
62
63 if (!np)
64 return false;
65
66 node_name = kbasename(np->full_name);
67 len = strchrnul(node_name, '@') - node_name;
68
69 return (strlen(name) == len) && (strncmp(node_name, name, len) == 0);
70}
71EXPORT_SYMBOL(of_node_name_eq);
72
73bool of_node_name_prefix(const struct device_node *np, const char *prefix)
74{
75 if (!np)
76 return false;
77
78 return strncmp(kbasename(np->full_name), prefix, strlen(prefix)) == 0;
79}
80EXPORT_SYMBOL(of_node_name_prefix);
81
82static bool __of_node_is_type(const struct device_node *np, const char *type)
83{
84 const char *match = __of_get_property(np, "device_type", NULL);
85
86 return np && match && type && !strcmp(match, type);
87}
88
89int of_bus_n_addr_cells(struct device_node *np)
90{
91 u32 cells;
92
93 for (; np; np = np->parent)
94 if (!of_property_read_u32(np, "#address-cells", &cells))
95 return cells;
96
97 /* No #address-cells property for the root node */
98 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
99}
100
101int of_n_addr_cells(struct device_node *np)
102{
103 if (np->parent)
104 np = np->parent;
105
106 return of_bus_n_addr_cells(np);
107}
108EXPORT_SYMBOL(of_n_addr_cells);
109
110int of_bus_n_size_cells(struct device_node *np)
111{
112 u32 cells;
113
114 for (; np; np = np->parent)
115 if (!of_property_read_u32(np, "#size-cells", &cells))
116 return cells;
117
118 /* No #size-cells property for the root node */
119 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
120}
121
122int of_n_size_cells(struct device_node *np)
123{
124 if (np->parent)
125 np = np->parent;
126
127 return of_bus_n_size_cells(np);
128}
129EXPORT_SYMBOL(of_n_size_cells);
130
131#ifdef CONFIG_NUMA
132int __weak of_node_to_nid(struct device_node *np)
133{
134 return NUMA_NO_NODE;
135}
136#endif
137
138#define OF_PHANDLE_CACHE_BITS 7
139#define OF_PHANDLE_CACHE_SZ BIT(OF_PHANDLE_CACHE_BITS)
140
141static struct device_node *phandle_cache[OF_PHANDLE_CACHE_SZ];
142
143static u32 of_phandle_cache_hash(phandle handle)
144{
145 return hash_32(handle, OF_PHANDLE_CACHE_BITS);
146}
147
148/*
149 * Caller must hold devtree_lock.
150 */
151void __of_phandle_cache_inv_entry(phandle handle)
152{
153 u32 handle_hash;
154 struct device_node *np;
155
156 if (!handle)
157 return;
158
159 handle_hash = of_phandle_cache_hash(handle);
160
161 np = phandle_cache[handle_hash];
162 if (np && handle == np->phandle)
163 phandle_cache[handle_hash] = NULL;
164}
165
166void __init of_core_init(void)
167{
168 struct device_node *np;
169
170
171 /* Create the kset, and register existing nodes */
172 mutex_lock(&of_mutex);
173 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
174 if (!of_kset) {
175 mutex_unlock(&of_mutex);
176 pr_err("failed to register existing nodes\n");
177 return;
178 }
179 for_each_of_allnodes(np) {
180 __of_attach_node_sysfs(np);
181 if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)])
182 phandle_cache[of_phandle_cache_hash(np->phandle)] = np;
183 }
184 mutex_unlock(&of_mutex);
185
186 /* Symlink in /proc as required by userspace ABI */
187 if (of_root)
188 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
189}
190
191static struct property *__of_find_property(const struct device_node *np,
192 const char *name, int *lenp)
193{
194 struct property *pp;
195
196 if (!np)
197 return NULL;
198
199 for (pp = np->properties; pp; pp = pp->next) {
200 if (of_prop_cmp(pp->name, name) == 0) {
201 if (lenp)
202 *lenp = pp->length;
203 break;
204 }
205 }
206
207 return pp;
208}
209
210struct property *of_find_property(const struct device_node *np,
211 const char *name,
212 int *lenp)
213{
214 struct property *pp;
215 unsigned long flags;
216
217 raw_spin_lock_irqsave(&devtree_lock, flags);
218 pp = __of_find_property(np, name, lenp);
219 raw_spin_unlock_irqrestore(&devtree_lock, flags);
220
221 return pp;
222}
223EXPORT_SYMBOL(of_find_property);
224
225struct device_node *__of_find_all_nodes(struct device_node *prev)
226{
227 struct device_node *np;
228 if (!prev) {
229 np = of_root;
230 } else if (prev->child) {
231 np = prev->child;
232 } else {
233 /* Walk back up looking for a sibling, or the end of the structure */
234 np = prev;
235 while (np->parent && !np->sibling)
236 np = np->parent;
237 np = np->sibling; /* Might be null at the end of the tree */
238 }
239 return np;
240}
241
242/**
243 * of_find_all_nodes - Get next node in global list
244 * @prev: Previous node or NULL to start iteration
245 * of_node_put() will be called on it
246 *
247 * Return: A node pointer with refcount incremented, use
248 * of_node_put() on it when done.
249 */
250struct device_node *of_find_all_nodes(struct device_node *prev)
251{
252 struct device_node *np;
253 unsigned long flags;
254
255 raw_spin_lock_irqsave(&devtree_lock, flags);
256 np = __of_find_all_nodes(prev);
257 of_node_get(np);
258 of_node_put(prev);
259 raw_spin_unlock_irqrestore(&devtree_lock, flags);
260 return np;
261}
262EXPORT_SYMBOL(of_find_all_nodes);
263
264/*
265 * Find a property with a given name for a given node
266 * and return the value.
267 */
268const void *__of_get_property(const struct device_node *np,
269 const char *name, int *lenp)
270{
271 struct property *pp = __of_find_property(np, name, lenp);
272
273 return pp ? pp->value : NULL;
274}
275
276/*
277 * Find a property with a given name for a given node
278 * and return the value.
279 */
280const void *of_get_property(const struct device_node *np, const char *name,
281 int *lenp)
282{
283 struct property *pp = of_find_property(np, name, lenp);
284
285 return pp ? pp->value : NULL;
286}
287EXPORT_SYMBOL(of_get_property);
288
289/**
290 * of_get_cpu_hwid - Get the hardware ID from a CPU device node
291 *
292 * @cpun: CPU number(logical index) for which device node is required
293 * @thread: The local thread number to get the hardware ID for.
294 *
295 * Return: The hardware ID for the CPU node or ~0ULL if not found.
296 */
297u64 of_get_cpu_hwid(struct device_node *cpun, unsigned int thread)
298{
299 const __be32 *cell;
300 int ac, len;
301
302 ac = of_n_addr_cells(cpun);
303 cell = of_get_property(cpun, "reg", &len);
304 if (!cell || !ac || ((sizeof(*cell) * ac * (thread + 1)) > len))
305 return ~0ULL;
306
307 cell += ac * thread;
308 return of_read_number(cell, ac);
309}
310
311/*
312 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
313 *
314 * @cpu: logical cpu index of a core/thread
315 * @phys_id: physical identifier of a core/thread
316 *
317 * CPU logical to physical index mapping is architecture specific.
318 * However this __weak function provides a default match of physical
319 * id to logical cpu index. phys_id provided here is usually values read
320 * from the device tree which must match the hardware internal registers.
321 *
322 * Returns true if the physical identifier and the logical cpu index
323 * correspond to the same core/thread, false otherwise.
324 */
325bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
326{
327 return (u32)phys_id == cpu;
328}
329
330/*
331 * Checks if the given "prop_name" property holds the physical id of the
332 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
333 * NULL, local thread number within the core is returned in it.
334 */
335static bool __of_find_n_match_cpu_property(struct device_node *cpun,
336 const char *prop_name, int cpu, unsigned int *thread)
337{
338 const __be32 *cell;
339 int ac, prop_len, tid;
340 u64 hwid;
341
342 ac = of_n_addr_cells(cpun);
343 cell = of_get_property(cpun, prop_name, &prop_len);
344 if (!cell && !ac && arch_match_cpu_phys_id(cpu, 0))
345 return true;
346 if (!cell || !ac)
347 return false;
348 prop_len /= sizeof(*cell) * ac;
349 for (tid = 0; tid < prop_len; tid++) {
350 hwid = of_read_number(cell, ac);
351 if (arch_match_cpu_phys_id(cpu, hwid)) {
352 if (thread)
353 *thread = tid;
354 return true;
355 }
356 cell += ac;
357 }
358 return false;
359}
360
361/*
362 * arch_find_n_match_cpu_physical_id - See if the given device node is
363 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
364 * else false. If 'thread' is non-NULL, the local thread number within the
365 * core is returned in it.
366 */
367bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
368 int cpu, unsigned int *thread)
369{
370 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
371 * for thread ids on PowerPC. If it doesn't exist fallback to
372 * standard "reg" property.
373 */
374 if (IS_ENABLED(CONFIG_PPC) &&
375 __of_find_n_match_cpu_property(cpun,
376 "ibm,ppc-interrupt-server#s",
377 cpu, thread))
378 return true;
379
380 return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
381}
382
383/**
384 * of_get_cpu_node - Get device node associated with the given logical CPU
385 *
386 * @cpu: CPU number(logical index) for which device node is required
387 * @thread: if not NULL, local thread number within the physical core is
388 * returned
389 *
390 * The main purpose of this function is to retrieve the device node for the
391 * given logical CPU index. It should be used to initialize the of_node in
392 * cpu device. Once of_node in cpu device is populated, all the further
393 * references can use that instead.
394 *
395 * CPU logical to physical index mapping is architecture specific and is built
396 * before booting secondary cores. This function uses arch_match_cpu_phys_id
397 * which can be overridden by architecture specific implementation.
398 *
399 * Return: A node pointer for the logical cpu with refcount incremented, use
400 * of_node_put() on it when done. Returns NULL if not found.
401 */
402struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
403{
404 struct device_node *cpun;
405
406 for_each_of_cpu_node(cpun) {
407 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
408 return cpun;
409 }
410 return NULL;
411}
412EXPORT_SYMBOL(of_get_cpu_node);
413
414/**
415 * of_cpu_node_to_id: Get the logical CPU number for a given device_node
416 *
417 * @cpu_node: Pointer to the device_node for CPU.
418 *
419 * Return: The logical CPU number of the given CPU device_node or -ENODEV if the
420 * CPU is not found.
421 */
422int of_cpu_node_to_id(struct device_node *cpu_node)
423{
424 int cpu;
425 bool found = false;
426 struct device_node *np;
427
428 for_each_possible_cpu(cpu) {
429 np = of_cpu_device_node_get(cpu);
430 found = (cpu_node == np);
431 of_node_put(np);
432 if (found)
433 return cpu;
434 }
435
436 return -ENODEV;
437}
438EXPORT_SYMBOL(of_cpu_node_to_id);
439
440/**
441 * of_get_cpu_state_node - Get CPU's idle state node at the given index
442 *
443 * @cpu_node: The device node for the CPU
444 * @index: The index in the list of the idle states
445 *
446 * Two generic methods can be used to describe a CPU's idle states, either via
447 * a flattened description through the "cpu-idle-states" binding or via the
448 * hierarchical layout, using the "power-domains" and the "domain-idle-states"
449 * bindings. This function check for both and returns the idle state node for
450 * the requested index.
451 *
452 * Return: An idle state node if found at @index. The refcount is incremented
453 * for it, so call of_node_put() on it when done. Returns NULL if not found.
454 */
455struct device_node *of_get_cpu_state_node(struct device_node *cpu_node,
456 int index)
457{
458 struct of_phandle_args args;
459 int err;
460
461 err = of_parse_phandle_with_args(cpu_node, "power-domains",
462 "#power-domain-cells", 0, &args);
463 if (!err) {
464 struct device_node *state_node =
465 of_parse_phandle(args.np, "domain-idle-states", index);
466
467 of_node_put(args.np);
468 if (state_node)
469 return state_node;
470 }
471
472 return of_parse_phandle(cpu_node, "cpu-idle-states", index);
473}
474EXPORT_SYMBOL(of_get_cpu_state_node);
475
476/**
477 * __of_device_is_compatible() - Check if the node matches given constraints
478 * @device: pointer to node
479 * @compat: required compatible string, NULL or "" for any match
480 * @type: required device_type value, NULL or "" for any match
481 * @name: required node name, NULL or "" for any match
482 *
483 * Checks if the given @compat, @type and @name strings match the
484 * properties of the given @device. A constraints can be skipped by
485 * passing NULL or an empty string as the constraint.
486 *
487 * Returns 0 for no match, and a positive integer on match. The return
488 * value is a relative score with larger values indicating better
489 * matches. The score is weighted for the most specific compatible value
490 * to get the highest score. Matching type is next, followed by matching
491 * name. Practically speaking, this results in the following priority
492 * order for matches:
493 *
494 * 1. specific compatible && type && name
495 * 2. specific compatible && type
496 * 3. specific compatible && name
497 * 4. specific compatible
498 * 5. general compatible && type && name
499 * 6. general compatible && type
500 * 7. general compatible && name
501 * 8. general compatible
502 * 9. type && name
503 * 10. type
504 * 11. name
505 */
506static int __of_device_is_compatible(const struct device_node *device,
507 const char *compat, const char *type, const char *name)
508{
509 struct property *prop;
510 const char *cp;
511 int index = 0, score = 0;
512
513 /* Compatible match has highest priority */
514 if (compat && compat[0]) {
515 prop = __of_find_property(device, "compatible", NULL);
516 for (cp = of_prop_next_string(prop, NULL); cp;
517 cp = of_prop_next_string(prop, cp), index++) {
518 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
519 score = INT_MAX/2 - (index << 2);
520 break;
521 }
522 }
523 if (!score)
524 return 0;
525 }
526
527 /* Matching type is better than matching name */
528 if (type && type[0]) {
529 if (!__of_node_is_type(device, type))
530 return 0;
531 score += 2;
532 }
533
534 /* Matching name is a bit better than not */
535 if (name && name[0]) {
536 if (!of_node_name_eq(device, name))
537 return 0;
538 score++;
539 }
540
541 return score;
542}
543
544/** Checks if the given "compat" string matches one of the strings in
545 * the device's "compatible" property
546 */
547int of_device_is_compatible(const struct device_node *device,
548 const char *compat)
549{
550 unsigned long flags;
551 int res;
552
553 raw_spin_lock_irqsave(&devtree_lock, flags);
554 res = __of_device_is_compatible(device, compat, NULL, NULL);
555 raw_spin_unlock_irqrestore(&devtree_lock, flags);
556 return res;
557}
558EXPORT_SYMBOL(of_device_is_compatible);
559
560/** Checks if the device is compatible with any of the entries in
561 * a NULL terminated array of strings. Returns the best match
562 * score or 0.
563 */
564int of_device_compatible_match(const struct device_node *device,
565 const char *const *compat)
566{
567 unsigned int tmp, score = 0;
568
569 if (!compat)
570 return 0;
571
572 while (*compat) {
573 tmp = of_device_is_compatible(device, *compat);
574 if (tmp > score)
575 score = tmp;
576 compat++;
577 }
578
579 return score;
580}
581EXPORT_SYMBOL_GPL(of_device_compatible_match);
582
583/**
584 * of_machine_is_compatible - Test root of device tree for a given compatible value
585 * @compat: compatible string to look for in root node's compatible property.
586 *
587 * Return: A positive integer if the root node has the given value in its
588 * compatible property.
589 */
590int of_machine_is_compatible(const char *compat)
591{
592 struct device_node *root;
593 int rc = 0;
594
595 root = of_find_node_by_path("/");
596 if (root) {
597 rc = of_device_is_compatible(root, compat);
598 of_node_put(root);
599 }
600 return rc;
601}
602EXPORT_SYMBOL(of_machine_is_compatible);
603
604/**
605 * __of_device_is_available - check if a device is available for use
606 *
607 * @device: Node to check for availability, with locks already held
608 *
609 * Return: True if the status property is absent or set to "okay" or "ok",
610 * false otherwise
611 */
612static bool __of_device_is_available(const struct device_node *device)
613{
614 const char *status;
615 int statlen;
616
617 if (!device)
618 return false;
619
620 status = __of_get_property(device, "status", &statlen);
621 if (status == NULL)
622 return true;
623
624 if (statlen > 0) {
625 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
626 return true;
627 }
628
629 return false;
630}
631
632/**
633 * of_device_is_available - check if a device is available for use
634 *
635 * @device: Node to check for availability
636 *
637 * Return: True if the status property is absent or set to "okay" or "ok",
638 * false otherwise
639 */
640bool of_device_is_available(const struct device_node *device)
641{
642 unsigned long flags;
643 bool res;
644
645 raw_spin_lock_irqsave(&devtree_lock, flags);
646 res = __of_device_is_available(device);
647 raw_spin_unlock_irqrestore(&devtree_lock, flags);
648 return res;
649
650}
651EXPORT_SYMBOL(of_device_is_available);
652
653/**
654 * __of_device_is_fail - check if a device has status "fail" or "fail-..."
655 *
656 * @device: Node to check status for, with locks already held
657 *
658 * Return: True if the status property is set to "fail" or "fail-..." (for any
659 * error code suffix), false otherwise
660 */
661static bool __of_device_is_fail(const struct device_node *device)
662{
663 const char *status;
664
665 if (!device)
666 return false;
667
668 status = __of_get_property(device, "status", NULL);
669 if (status == NULL)
670 return false;
671
672 return !strcmp(status, "fail") || !strncmp(status, "fail-", 5);
673}
674
675/**
676 * of_device_is_big_endian - check if a device has BE registers
677 *
678 * @device: Node to check for endianness
679 *
680 * Return: True if the device has a "big-endian" property, or if the kernel
681 * was compiled for BE *and* the device has a "native-endian" property.
682 * Returns false otherwise.
683 *
684 * Callers would nominally use ioread32be/iowrite32be if
685 * of_device_is_big_endian() == true, or readl/writel otherwise.
686 */
687bool of_device_is_big_endian(const struct device_node *device)
688{
689 if (of_property_read_bool(device, "big-endian"))
690 return true;
691 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
692 of_property_read_bool(device, "native-endian"))
693 return true;
694 return false;
695}
696EXPORT_SYMBOL(of_device_is_big_endian);
697
698/**
699 * of_get_parent - Get a node's parent if any
700 * @node: Node to get parent
701 *
702 * Return: A node pointer with refcount incremented, use
703 * of_node_put() on it when done.
704 */
705struct device_node *of_get_parent(const struct device_node *node)
706{
707 struct device_node *np;
708 unsigned long flags;
709
710 if (!node)
711 return NULL;
712
713 raw_spin_lock_irqsave(&devtree_lock, flags);
714 np = of_node_get(node->parent);
715 raw_spin_unlock_irqrestore(&devtree_lock, flags);
716 return np;
717}
718EXPORT_SYMBOL(of_get_parent);
719
720/**
721 * of_get_next_parent - Iterate to a node's parent
722 * @node: Node to get parent of
723 *
724 * This is like of_get_parent() except that it drops the
725 * refcount on the passed node, making it suitable for iterating
726 * through a node's parents.
727 *
728 * Return: A node pointer with refcount incremented, use
729 * of_node_put() on it when done.
730 */
731struct device_node *of_get_next_parent(struct device_node *node)
732{
733 struct device_node *parent;
734 unsigned long flags;
735
736 if (!node)
737 return NULL;
738
739 raw_spin_lock_irqsave(&devtree_lock, flags);
740 parent = of_node_get(node->parent);
741 of_node_put(node);
742 raw_spin_unlock_irqrestore(&devtree_lock, flags);
743 return parent;
744}
745EXPORT_SYMBOL(of_get_next_parent);
746
747static struct device_node *__of_get_next_child(const struct device_node *node,
748 struct device_node *prev)
749{
750 struct device_node *next;
751
752 if (!node)
753 return NULL;
754
755 next = prev ? prev->sibling : node->child;
756 of_node_get(next);
757 of_node_put(prev);
758 return next;
759}
760#define __for_each_child_of_node(parent, child) \
761 for (child = __of_get_next_child(parent, NULL); child != NULL; \
762 child = __of_get_next_child(parent, child))
763
764/**
765 * of_get_next_child - Iterate a node childs
766 * @node: parent node
767 * @prev: previous child of the parent node, or NULL to get first
768 *
769 * Return: A node pointer with refcount incremented, use of_node_put() on
770 * it when done. Returns NULL when prev is the last child. Decrements the
771 * refcount of prev.
772 */
773struct device_node *of_get_next_child(const struct device_node *node,
774 struct device_node *prev)
775{
776 struct device_node *next;
777 unsigned long flags;
778
779 raw_spin_lock_irqsave(&devtree_lock, flags);
780 next = __of_get_next_child(node, prev);
781 raw_spin_unlock_irqrestore(&devtree_lock, flags);
782 return next;
783}
784EXPORT_SYMBOL(of_get_next_child);
785
786/**
787 * of_get_next_available_child - Find the next available child node
788 * @node: parent node
789 * @prev: previous child of the parent node, or NULL to get first
790 *
791 * This function is like of_get_next_child(), except that it
792 * automatically skips any disabled nodes (i.e. status = "disabled").
793 */
794struct device_node *of_get_next_available_child(const struct device_node *node,
795 struct device_node *prev)
796{
797 struct device_node *next;
798 unsigned long flags;
799
800 if (!node)
801 return NULL;
802
803 raw_spin_lock_irqsave(&devtree_lock, flags);
804 next = prev ? prev->sibling : node->child;
805 for (; next; next = next->sibling) {
806 if (!__of_device_is_available(next))
807 continue;
808 if (of_node_get(next))
809 break;
810 }
811 of_node_put(prev);
812 raw_spin_unlock_irqrestore(&devtree_lock, flags);
813 return next;
814}
815EXPORT_SYMBOL(of_get_next_available_child);
816
817/**
818 * of_get_next_cpu_node - Iterate on cpu nodes
819 * @prev: previous child of the /cpus node, or NULL to get first
820 *
821 * Unusable CPUs (those with the status property set to "fail" or "fail-...")
822 * will be skipped.
823 *
824 * Return: A cpu node pointer with refcount incremented, use of_node_put()
825 * on it when done. Returns NULL when prev is the last child. Decrements
826 * the refcount of prev.
827 */
828struct device_node *of_get_next_cpu_node(struct device_node *prev)
829{
830 struct device_node *next = NULL;
831 unsigned long flags;
832 struct device_node *node;
833
834 if (!prev)
835 node = of_find_node_by_path("/cpus");
836
837 raw_spin_lock_irqsave(&devtree_lock, flags);
838 if (prev)
839 next = prev->sibling;
840 else if (node) {
841 next = node->child;
842 of_node_put(node);
843 }
844 for (; next; next = next->sibling) {
845 if (__of_device_is_fail(next))
846 continue;
847 if (!(of_node_name_eq(next, "cpu") ||
848 __of_node_is_type(next, "cpu")))
849 continue;
850 if (of_node_get(next))
851 break;
852 }
853 of_node_put(prev);
854 raw_spin_unlock_irqrestore(&devtree_lock, flags);
855 return next;
856}
857EXPORT_SYMBOL(of_get_next_cpu_node);
858
859/**
860 * of_get_compatible_child - Find compatible child node
861 * @parent: parent node
862 * @compatible: compatible string
863 *
864 * Lookup child node whose compatible property contains the given compatible
865 * string.
866 *
867 * Return: a node pointer with refcount incremented, use of_node_put() on it
868 * when done; or NULL if not found.
869 */
870struct device_node *of_get_compatible_child(const struct device_node *parent,
871 const char *compatible)
872{
873 struct device_node *child;
874
875 for_each_child_of_node(parent, child) {
876 if (of_device_is_compatible(child, compatible))
877 break;
878 }
879
880 return child;
881}
882EXPORT_SYMBOL(of_get_compatible_child);
883
884/**
885 * of_get_child_by_name - Find the child node by name for a given parent
886 * @node: parent node
887 * @name: child name to look for.
888 *
889 * This function looks for child node for given matching name
890 *
891 * Return: A node pointer if found, with refcount incremented, use
892 * of_node_put() on it when done.
893 * Returns NULL if node is not found.
894 */
895struct device_node *of_get_child_by_name(const struct device_node *node,
896 const char *name)
897{
898 struct device_node *child;
899
900 for_each_child_of_node(node, child)
901 if (of_node_name_eq(child, name))
902 break;
903 return child;
904}
905EXPORT_SYMBOL(of_get_child_by_name);
906
907struct device_node *__of_find_node_by_path(struct device_node *parent,
908 const char *path)
909{
910 struct device_node *child;
911 int len;
912
913 len = strcspn(path, "/:");
914 if (!len)
915 return NULL;
916
917 __for_each_child_of_node(parent, child) {
918 const char *name = kbasename(child->full_name);
919 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
920 return child;
921 }
922 return NULL;
923}
924
925struct device_node *__of_find_node_by_full_path(struct device_node *node,
926 const char *path)
927{
928 const char *separator = strchr(path, ':');
929
930 while (node && *path == '/') {
931 struct device_node *tmp = node;
932
933 path++; /* Increment past '/' delimiter */
934 node = __of_find_node_by_path(node, path);
935 of_node_put(tmp);
936 path = strchrnul(path, '/');
937 if (separator && separator < path)
938 break;
939 }
940 return node;
941}
942
943/**
944 * of_find_node_opts_by_path - Find a node matching a full OF path
945 * @path: Either the full path to match, or if the path does not
946 * start with '/', the name of a property of the /aliases
947 * node (an alias). In the case of an alias, the node
948 * matching the alias' value will be returned.
949 * @opts: Address of a pointer into which to store the start of
950 * an options string appended to the end of the path with
951 * a ':' separator.
952 *
953 * Valid paths:
954 * * /foo/bar Full path
955 * * foo Valid alias
956 * * foo/bar Valid alias + relative path
957 *
958 * Return: A node pointer with refcount incremented, use
959 * of_node_put() on it when done.
960 */
961struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
962{
963 struct device_node *np = NULL;
964 struct property *pp;
965 unsigned long flags;
966 const char *separator = strchr(path, ':');
967
968 if (opts)
969 *opts = separator ? separator + 1 : NULL;
970
971 if (strcmp(path, "/") == 0)
972 return of_node_get(of_root);
973
974 /* The path could begin with an alias */
975 if (*path != '/') {
976 int len;
977 const char *p = separator;
978
979 if (!p)
980 p = strchrnul(path, '/');
981 len = p - path;
982
983 /* of_aliases must not be NULL */
984 if (!of_aliases)
985 return NULL;
986
987 for_each_property_of_node(of_aliases, pp) {
988 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
989 np = of_find_node_by_path(pp->value);
990 break;
991 }
992 }
993 if (!np)
994 return NULL;
995 path = p;
996 }
997
998 /* Step down the tree matching path components */
999 raw_spin_lock_irqsave(&devtree_lock, flags);
1000 if (!np)
1001 np = of_node_get(of_root);
1002 np = __of_find_node_by_full_path(np, path);
1003 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1004 return np;
1005}
1006EXPORT_SYMBOL(of_find_node_opts_by_path);
1007
1008/**
1009 * of_find_node_by_name - Find a node by its "name" property
1010 * @from: The node to start searching from or NULL; the node
1011 * you pass will not be searched, only the next one
1012 * will. Typically, you pass what the previous call
1013 * returned. of_node_put() will be called on @from.
1014 * @name: The name string to match against
1015 *
1016 * Return: A node pointer with refcount incremented, use
1017 * of_node_put() on it when done.
1018 */
1019struct device_node *of_find_node_by_name(struct device_node *from,
1020 const char *name)
1021{
1022 struct device_node *np;
1023 unsigned long flags;
1024
1025 raw_spin_lock_irqsave(&devtree_lock, flags);
1026 for_each_of_allnodes_from(from, np)
1027 if (of_node_name_eq(np, name) && of_node_get(np))
1028 break;
1029 of_node_put(from);
1030 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1031 return np;
1032}
1033EXPORT_SYMBOL(of_find_node_by_name);
1034
1035/**
1036 * of_find_node_by_type - Find a node by its "device_type" property
1037 * @from: The node to start searching from, or NULL to start searching
1038 * the entire device tree. The node you pass will not be
1039 * searched, only the next one will; typically, you pass
1040 * what the previous call returned. of_node_put() will be
1041 * called on from for you.
1042 * @type: The type string to match against
1043 *
1044 * Return: A node pointer with refcount incremented, use
1045 * of_node_put() on it when done.
1046 */
1047struct device_node *of_find_node_by_type(struct device_node *from,
1048 const char *type)
1049{
1050 struct device_node *np;
1051 unsigned long flags;
1052
1053 raw_spin_lock_irqsave(&devtree_lock, flags);
1054 for_each_of_allnodes_from(from, np)
1055 if (__of_node_is_type(np, type) && of_node_get(np))
1056 break;
1057 of_node_put(from);
1058 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1059 return np;
1060}
1061EXPORT_SYMBOL(of_find_node_by_type);
1062
1063/**
1064 * of_find_compatible_node - Find a node based on type and one of the
1065 * tokens in its "compatible" property
1066 * @from: The node to start searching from or NULL, the node
1067 * you pass will not be searched, only the next one
1068 * will; typically, you pass what the previous call
1069 * returned. of_node_put() will be called on it
1070 * @type: The type string to match "device_type" or NULL to ignore
1071 * @compatible: The string to match to one of the tokens in the device
1072 * "compatible" list.
1073 *
1074 * Return: A node pointer with refcount incremented, use
1075 * of_node_put() on it when done.
1076 */
1077struct device_node *of_find_compatible_node(struct device_node *from,
1078 const char *type, const char *compatible)
1079{
1080 struct device_node *np;
1081 unsigned long flags;
1082
1083 raw_spin_lock_irqsave(&devtree_lock, flags);
1084 for_each_of_allnodes_from(from, np)
1085 if (__of_device_is_compatible(np, compatible, type, NULL) &&
1086 of_node_get(np))
1087 break;
1088 of_node_put(from);
1089 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1090 return np;
1091}
1092EXPORT_SYMBOL(of_find_compatible_node);
1093
1094/**
1095 * of_find_node_with_property - Find a node which has a property with
1096 * the given name.
1097 * @from: The node to start searching from or NULL, the node
1098 * you pass will not be searched, only the next one
1099 * will; typically, you pass what the previous call
1100 * returned. of_node_put() will be called on it
1101 * @prop_name: The name of the property to look for.
1102 *
1103 * Return: A node pointer with refcount incremented, use
1104 * of_node_put() on it when done.
1105 */
1106struct device_node *of_find_node_with_property(struct device_node *from,
1107 const char *prop_name)
1108{
1109 struct device_node *np;
1110 struct property *pp;
1111 unsigned long flags;
1112
1113 raw_spin_lock_irqsave(&devtree_lock, flags);
1114 for_each_of_allnodes_from(from, np) {
1115 for (pp = np->properties; pp; pp = pp->next) {
1116 if (of_prop_cmp(pp->name, prop_name) == 0) {
1117 of_node_get(np);
1118 goto out;
1119 }
1120 }
1121 }
1122out:
1123 of_node_put(from);
1124 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1125 return np;
1126}
1127EXPORT_SYMBOL(of_find_node_with_property);
1128
1129static
1130const struct of_device_id *__of_match_node(const struct of_device_id *matches,
1131 const struct device_node *node)
1132{
1133 const struct of_device_id *best_match = NULL;
1134 int score, best_score = 0;
1135
1136 if (!matches)
1137 return NULL;
1138
1139 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
1140 score = __of_device_is_compatible(node, matches->compatible,
1141 matches->type, matches->name);
1142 if (score > best_score) {
1143 best_match = matches;
1144 best_score = score;
1145 }
1146 }
1147
1148 return best_match;
1149}
1150
1151/**
1152 * of_match_node - Tell if a device_node has a matching of_match structure
1153 * @matches: array of of device match structures to search in
1154 * @node: the of device structure to match against
1155 *
1156 * Low level utility function used by device matching.
1157 */
1158const struct of_device_id *of_match_node(const struct of_device_id *matches,
1159 const struct device_node *node)
1160{
1161 const struct of_device_id *match;
1162 unsigned long flags;
1163
1164 raw_spin_lock_irqsave(&devtree_lock, flags);
1165 match = __of_match_node(matches, node);
1166 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1167 return match;
1168}
1169EXPORT_SYMBOL(of_match_node);
1170
1171/**
1172 * of_find_matching_node_and_match - Find a node based on an of_device_id
1173 * match table.
1174 * @from: The node to start searching from or NULL, the node
1175 * you pass will not be searched, only the next one
1176 * will; typically, you pass what the previous call
1177 * returned. of_node_put() will be called on it
1178 * @matches: array of of device match structures to search in
1179 * @match: Updated to point at the matches entry which matched
1180 *
1181 * Return: A node pointer with refcount incremented, use
1182 * of_node_put() on it when done.
1183 */
1184struct device_node *of_find_matching_node_and_match(struct device_node *from,
1185 const struct of_device_id *matches,
1186 const struct of_device_id **match)
1187{
1188 struct device_node *np;
1189 const struct of_device_id *m;
1190 unsigned long flags;
1191
1192 if (match)
1193 *match = NULL;
1194
1195 raw_spin_lock_irqsave(&devtree_lock, flags);
1196 for_each_of_allnodes_from(from, np) {
1197 m = __of_match_node(matches, np);
1198 if (m && of_node_get(np)) {
1199 if (match)
1200 *match = m;
1201 break;
1202 }
1203 }
1204 of_node_put(from);
1205 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1206 return np;
1207}
1208EXPORT_SYMBOL(of_find_matching_node_and_match);
1209
1210/**
1211 * of_modalias_node - Lookup appropriate modalias for a device node
1212 * @node: pointer to a device tree node
1213 * @modalias: Pointer to buffer that modalias value will be copied into
1214 * @len: Length of modalias value
1215 *
1216 * Based on the value of the compatible property, this routine will attempt
1217 * to choose an appropriate modalias value for a particular device tree node.
1218 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1219 * from the first entry in the compatible list property.
1220 *
1221 * Return: This routine returns 0 on success, <0 on failure.
1222 */
1223int of_modalias_node(struct device_node *node, char *modalias, int len)
1224{
1225 const char *compatible, *p;
1226 int cplen;
1227
1228 compatible = of_get_property(node, "compatible", &cplen);
1229 if (!compatible || strlen(compatible) > cplen)
1230 return -ENODEV;
1231 p = strchr(compatible, ',');
1232 strscpy(modalias, p ? p + 1 : compatible, len);
1233 return 0;
1234}
1235EXPORT_SYMBOL_GPL(of_modalias_node);
1236
1237/**
1238 * of_find_node_by_phandle - Find a node given a phandle
1239 * @handle: phandle of the node to find
1240 *
1241 * Return: A node pointer with refcount incremented, use
1242 * of_node_put() on it when done.
1243 */
1244struct device_node *of_find_node_by_phandle(phandle handle)
1245{
1246 struct device_node *np = NULL;
1247 unsigned long flags;
1248 u32 handle_hash;
1249
1250 if (!handle)
1251 return NULL;
1252
1253 handle_hash = of_phandle_cache_hash(handle);
1254
1255 raw_spin_lock_irqsave(&devtree_lock, flags);
1256
1257 if (phandle_cache[handle_hash] &&
1258 handle == phandle_cache[handle_hash]->phandle)
1259 np = phandle_cache[handle_hash];
1260
1261 if (!np) {
1262 for_each_of_allnodes(np)
1263 if (np->phandle == handle &&
1264 !of_node_check_flag(np, OF_DETACHED)) {
1265 phandle_cache[handle_hash] = np;
1266 break;
1267 }
1268 }
1269
1270 of_node_get(np);
1271 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1272 return np;
1273}
1274EXPORT_SYMBOL(of_find_node_by_phandle);
1275
1276void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1277{
1278 int i;
1279 printk("%s %pOF", msg, args->np);
1280 for (i = 0; i < args->args_count; i++) {
1281 const char delim = i ? ',' : ':';
1282
1283 pr_cont("%c%08x", delim, args->args[i]);
1284 }
1285 pr_cont("\n");
1286}
1287
1288int of_phandle_iterator_init(struct of_phandle_iterator *it,
1289 const struct device_node *np,
1290 const char *list_name,
1291 const char *cells_name,
1292 int cell_count)
1293{
1294 const __be32 *list;
1295 int size;
1296
1297 memset(it, 0, sizeof(*it));
1298
1299 /*
1300 * one of cell_count or cells_name must be provided to determine the
1301 * argument length.
1302 */
1303 if (cell_count < 0 && !cells_name)
1304 return -EINVAL;
1305
1306 list = of_get_property(np, list_name, &size);
1307 if (!list)
1308 return -ENOENT;
1309
1310 it->cells_name = cells_name;
1311 it->cell_count = cell_count;
1312 it->parent = np;
1313 it->list_end = list + size / sizeof(*list);
1314 it->phandle_end = list;
1315 it->cur = list;
1316
1317 return 0;
1318}
1319EXPORT_SYMBOL_GPL(of_phandle_iterator_init);
1320
1321int of_phandle_iterator_next(struct of_phandle_iterator *it)
1322{
1323 uint32_t count = 0;
1324
1325 if (it->node) {
1326 of_node_put(it->node);
1327 it->node = NULL;
1328 }
1329
1330 if (!it->cur || it->phandle_end >= it->list_end)
1331 return -ENOENT;
1332
1333 it->cur = it->phandle_end;
1334
1335 /* If phandle is 0, then it is an empty entry with no arguments. */
1336 it->phandle = be32_to_cpup(it->cur++);
1337
1338 if (it->phandle) {
1339
1340 /*
1341 * Find the provider node and parse the #*-cells property to
1342 * determine the argument length.
1343 */
1344 it->node = of_find_node_by_phandle(it->phandle);
1345
1346 if (it->cells_name) {
1347 if (!it->node) {
1348 pr_err("%pOF: could not find phandle %d\n",
1349 it->parent, it->phandle);
1350 goto err;
1351 }
1352
1353 if (of_property_read_u32(it->node, it->cells_name,
1354 &count)) {
1355 /*
1356 * If both cell_count and cells_name is given,
1357 * fall back to cell_count in absence
1358 * of the cells_name property
1359 */
1360 if (it->cell_count >= 0) {
1361 count = it->cell_count;
1362 } else {
1363 pr_err("%pOF: could not get %s for %pOF\n",
1364 it->parent,
1365 it->cells_name,
1366 it->node);
1367 goto err;
1368 }
1369 }
1370 } else {
1371 count = it->cell_count;
1372 }
1373
1374 /*
1375 * Make sure that the arguments actually fit in the remaining
1376 * property data length
1377 */
1378 if (it->cur + count > it->list_end) {
1379 if (it->cells_name)
1380 pr_err("%pOF: %s = %d found %td\n",
1381 it->parent, it->cells_name,
1382 count, it->list_end - it->cur);
1383 else
1384 pr_err("%pOF: phandle %s needs %d, found %td\n",
1385 it->parent, of_node_full_name(it->node),
1386 count, it->list_end - it->cur);
1387 goto err;
1388 }
1389 }
1390
1391 it->phandle_end = it->cur + count;
1392 it->cur_count = count;
1393
1394 return 0;
1395
1396err:
1397 if (it->node) {
1398 of_node_put(it->node);
1399 it->node = NULL;
1400 }
1401
1402 return -EINVAL;
1403}
1404EXPORT_SYMBOL_GPL(of_phandle_iterator_next);
1405
1406int of_phandle_iterator_args(struct of_phandle_iterator *it,
1407 uint32_t *args,
1408 int size)
1409{
1410 int i, count;
1411
1412 count = it->cur_count;
1413
1414 if (WARN_ON(size < count))
1415 count = size;
1416
1417 for (i = 0; i < count; i++)
1418 args[i] = be32_to_cpup(it->cur++);
1419
1420 return count;
1421}
1422
1423int __of_parse_phandle_with_args(const struct device_node *np,
1424 const char *list_name,
1425 const char *cells_name,
1426 int cell_count, int index,
1427 struct of_phandle_args *out_args)
1428{
1429 struct of_phandle_iterator it;
1430 int rc, cur_index = 0;
1431
1432 if (index < 0)
1433 return -EINVAL;
1434
1435 /* Loop over the phandles until all the requested entry is found */
1436 of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
1437 /*
1438 * All of the error cases bail out of the loop, so at
1439 * this point, the parsing is successful. If the requested
1440 * index matches, then fill the out_args structure and return,
1441 * or return -ENOENT for an empty entry.
1442 */
1443 rc = -ENOENT;
1444 if (cur_index == index) {
1445 if (!it.phandle)
1446 goto err;
1447
1448 if (out_args) {
1449 int c;
1450
1451 c = of_phandle_iterator_args(&it,
1452 out_args->args,
1453 MAX_PHANDLE_ARGS);
1454 out_args->np = it.node;
1455 out_args->args_count = c;
1456 } else {
1457 of_node_put(it.node);
1458 }
1459
1460 /* Found it! return success */
1461 return 0;
1462 }
1463
1464 cur_index++;
1465 }
1466
1467 /*
1468 * Unlock node before returning result; will be one of:
1469 * -ENOENT : index is for empty phandle
1470 * -EINVAL : parsing error on data
1471 */
1472
1473 err:
1474 of_node_put(it.node);
1475 return rc;
1476}
1477EXPORT_SYMBOL(__of_parse_phandle_with_args);
1478
1479/**
1480 * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it
1481 * @np: pointer to a device tree node containing a list
1482 * @list_name: property name that contains a list
1483 * @stem_name: stem of property names that specify phandles' arguments count
1484 * @index: index of a phandle to parse out
1485 * @out_args: optional pointer to output arguments structure (will be filled)
1486 *
1487 * This function is useful to parse lists of phandles and their arguments.
1488 * Returns 0 on success and fills out_args, on error returns appropriate errno
1489 * value. The difference between this function and of_parse_phandle_with_args()
1490 * is that this API remaps a phandle if the node the phandle points to has
1491 * a <@stem_name>-map property.
1492 *
1493 * Caller is responsible to call of_node_put() on the returned out_args->np
1494 * pointer.
1495 *
1496 * Example::
1497 *
1498 * phandle1: node1 {
1499 * #list-cells = <2>;
1500 * };
1501 *
1502 * phandle2: node2 {
1503 * #list-cells = <1>;
1504 * };
1505 *
1506 * phandle3: node3 {
1507 * #list-cells = <1>;
1508 * list-map = <0 &phandle2 3>,
1509 * <1 &phandle2 2>,
1510 * <2 &phandle1 5 1>;
1511 * list-map-mask = <0x3>;
1512 * };
1513 *
1514 * node4 {
1515 * list = <&phandle1 1 2 &phandle3 0>;
1516 * };
1517 *
1518 * To get a device_node of the ``node2`` node you may call this:
1519 * of_parse_phandle_with_args(node4, "list", "list", 1, &args);
1520 */
1521int of_parse_phandle_with_args_map(const struct device_node *np,
1522 const char *list_name,
1523 const char *stem_name,
1524 int index, struct of_phandle_args *out_args)
1525{
1526 char *cells_name, *map_name = NULL, *mask_name = NULL;
1527 char *pass_name = NULL;
1528 struct device_node *cur, *new = NULL;
1529 const __be32 *map, *mask, *pass;
1530 static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 };
1531 static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = 0 };
1532 __be32 initial_match_array[MAX_PHANDLE_ARGS];
1533 const __be32 *match_array = initial_match_array;
1534 int i, ret, map_len, match;
1535 u32 list_size, new_size;
1536
1537 if (index < 0)
1538 return -EINVAL;
1539
1540 cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
1541 if (!cells_name)
1542 return -ENOMEM;
1543
1544 ret = -ENOMEM;
1545 map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name);
1546 if (!map_name)
1547 goto free;
1548
1549 mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
1550 if (!mask_name)
1551 goto free;
1552
1553 pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
1554 if (!pass_name)
1555 goto free;
1556
1557 ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
1558 out_args);
1559 if (ret)
1560 goto free;
1561
1562 /* Get the #<list>-cells property */
1563 cur = out_args->np;
1564 ret = of_property_read_u32(cur, cells_name, &list_size);
1565 if (ret < 0)
1566 goto put;
1567
1568 /* Precalculate the match array - this simplifies match loop */
1569 for (i = 0; i < list_size; i++)
1570 initial_match_array[i] = cpu_to_be32(out_args->args[i]);
1571
1572 ret = -EINVAL;
1573 while (cur) {
1574 /* Get the <list>-map property */
1575 map = of_get_property(cur, map_name, &map_len);
1576 if (!map) {
1577 ret = 0;
1578 goto free;
1579 }
1580 map_len /= sizeof(u32);
1581
1582 /* Get the <list>-map-mask property (optional) */
1583 mask = of_get_property(cur, mask_name, NULL);
1584 if (!mask)
1585 mask = dummy_mask;
1586 /* Iterate through <list>-map property */
1587 match = 0;
1588 while (map_len > (list_size + 1) && !match) {
1589 /* Compare specifiers */
1590 match = 1;
1591 for (i = 0; i < list_size; i++, map_len--)
1592 match &= !((match_array[i] ^ *map++) & mask[i]);
1593
1594 of_node_put(new);
1595 new = of_find_node_by_phandle(be32_to_cpup(map));
1596 map++;
1597 map_len--;
1598
1599 /* Check if not found */
1600 if (!new)
1601 goto put;
1602
1603 if (!of_device_is_available(new))
1604 match = 0;
1605
1606 ret = of_property_read_u32(new, cells_name, &new_size);
1607 if (ret)
1608 goto put;
1609
1610 /* Check for malformed properties */
1611 if (WARN_ON(new_size > MAX_PHANDLE_ARGS))
1612 goto put;
1613 if (map_len < new_size)
1614 goto put;
1615
1616 /* Move forward by new node's #<list>-cells amount */
1617 map += new_size;
1618 map_len -= new_size;
1619 }
1620 if (!match)
1621 goto put;
1622
1623 /* Get the <list>-map-pass-thru property (optional) */
1624 pass = of_get_property(cur, pass_name, NULL);
1625 if (!pass)
1626 pass = dummy_pass;
1627
1628 /*
1629 * Successfully parsed a <list>-map translation; copy new
1630 * specifier into the out_args structure, keeping the
1631 * bits specified in <list>-map-pass-thru.
1632 */
1633 match_array = map - new_size;
1634 for (i = 0; i < new_size; i++) {
1635 __be32 val = *(map - new_size + i);
1636
1637 if (i < list_size) {
1638 val &= ~pass[i];
1639 val |= cpu_to_be32(out_args->args[i]) & pass[i];
1640 }
1641
1642 out_args->args[i] = be32_to_cpu(val);
1643 }
1644 out_args->args_count = list_size = new_size;
1645 /* Iterate again with new provider */
1646 out_args->np = new;
1647 of_node_put(cur);
1648 cur = new;
1649 }
1650put:
1651 of_node_put(cur);
1652 of_node_put(new);
1653free:
1654 kfree(mask_name);
1655 kfree(map_name);
1656 kfree(cells_name);
1657 kfree(pass_name);
1658
1659 return ret;
1660}
1661EXPORT_SYMBOL(of_parse_phandle_with_args_map);
1662
1663/**
1664 * of_count_phandle_with_args() - Find the number of phandles references in a property
1665 * @np: pointer to a device tree node containing a list
1666 * @list_name: property name that contains a list
1667 * @cells_name: property name that specifies phandles' arguments count
1668 *
1669 * Return: The number of phandle + argument tuples within a property. It
1670 * is a typical pattern to encode a list of phandle and variable
1671 * arguments into a single property. The number of arguments is encoded
1672 * by a property in the phandle-target node. For example, a gpios
1673 * property would contain a list of GPIO specifies consisting of a
1674 * phandle and 1 or more arguments. The number of arguments are
1675 * determined by the #gpio-cells property in the node pointed to by the
1676 * phandle.
1677 */
1678int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1679 const char *cells_name)
1680{
1681 struct of_phandle_iterator it;
1682 int rc, cur_index = 0;
1683
1684 /*
1685 * If cells_name is NULL we assume a cell count of 0. This makes
1686 * counting the phandles trivial as each 32bit word in the list is a
1687 * phandle and no arguments are to consider. So we don't iterate through
1688 * the list but just use the length to determine the phandle count.
1689 */
1690 if (!cells_name) {
1691 const __be32 *list;
1692 int size;
1693
1694 list = of_get_property(np, list_name, &size);
1695 if (!list)
1696 return -ENOENT;
1697
1698 return size / sizeof(*list);
1699 }
1700
1701 rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
1702 if (rc)
1703 return rc;
1704
1705 while ((rc = of_phandle_iterator_next(&it)) == 0)
1706 cur_index += 1;
1707
1708 if (rc != -ENOENT)
1709 return rc;
1710
1711 return cur_index;
1712}
1713EXPORT_SYMBOL(of_count_phandle_with_args);
1714
1715/**
1716 * __of_add_property - Add a property to a node without lock operations
1717 * @np: Caller's Device Node
1718 * @prop: Property to add
1719 */
1720int __of_add_property(struct device_node *np, struct property *prop)
1721{
1722 struct property **next;
1723
1724 prop->next = NULL;
1725 next = &np->properties;
1726 while (*next) {
1727 if (strcmp(prop->name, (*next)->name) == 0)
1728 /* duplicate ! don't insert it */
1729 return -EEXIST;
1730
1731 next = &(*next)->next;
1732 }
1733 *next = prop;
1734
1735 return 0;
1736}
1737
1738/**
1739 * of_add_property - Add a property to a node
1740 * @np: Caller's Device Node
1741 * @prop: Property to add
1742 */
1743int of_add_property(struct device_node *np, struct property *prop)
1744{
1745 unsigned long flags;
1746 int rc;
1747
1748 mutex_lock(&of_mutex);
1749
1750 raw_spin_lock_irqsave(&devtree_lock, flags);
1751 rc = __of_add_property(np, prop);
1752 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1753
1754 if (!rc)
1755 __of_add_property_sysfs(np, prop);
1756
1757 mutex_unlock(&of_mutex);
1758
1759 if (!rc)
1760 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1761
1762 return rc;
1763}
1764EXPORT_SYMBOL_GPL(of_add_property);
1765
1766int __of_remove_property(struct device_node *np, struct property *prop)
1767{
1768 struct property **next;
1769
1770 for (next = &np->properties; *next; next = &(*next)->next) {
1771 if (*next == prop)
1772 break;
1773 }
1774 if (*next == NULL)
1775 return -ENODEV;
1776
1777 /* found the node */
1778 *next = prop->next;
1779 prop->next = np->deadprops;
1780 np->deadprops = prop;
1781
1782 return 0;
1783}
1784
1785/**
1786 * of_remove_property - Remove a property from a node.
1787 * @np: Caller's Device Node
1788 * @prop: Property to remove
1789 *
1790 * Note that we don't actually remove it, since we have given out
1791 * who-knows-how-many pointers to the data using get-property.
1792 * Instead we just move the property to the "dead properties"
1793 * list, so it won't be found any more.
1794 */
1795int of_remove_property(struct device_node *np, struct property *prop)
1796{
1797 unsigned long flags;
1798 int rc;
1799
1800 if (!prop)
1801 return -ENODEV;
1802
1803 mutex_lock(&of_mutex);
1804
1805 raw_spin_lock_irqsave(&devtree_lock, flags);
1806 rc = __of_remove_property(np, prop);
1807 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1808
1809 if (!rc)
1810 __of_remove_property_sysfs(np, prop);
1811
1812 mutex_unlock(&of_mutex);
1813
1814 if (!rc)
1815 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1816
1817 return rc;
1818}
1819EXPORT_SYMBOL_GPL(of_remove_property);
1820
1821int __of_update_property(struct device_node *np, struct property *newprop,
1822 struct property **oldpropp)
1823{
1824 struct property **next, *oldprop;
1825
1826 for (next = &np->properties; *next; next = &(*next)->next) {
1827 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1828 break;
1829 }
1830 *oldpropp = oldprop = *next;
1831
1832 if (oldprop) {
1833 /* replace the node */
1834 newprop->next = oldprop->next;
1835 *next = newprop;
1836 oldprop->next = np->deadprops;
1837 np->deadprops = oldprop;
1838 } else {
1839 /* new node */
1840 newprop->next = NULL;
1841 *next = newprop;
1842 }
1843
1844 return 0;
1845}
1846
1847/*
1848 * of_update_property - Update a property in a node, if the property does
1849 * not exist, add it.
1850 *
1851 * Note that we don't actually remove it, since we have given out
1852 * who-knows-how-many pointers to the data using get-property.
1853 * Instead we just move the property to the "dead properties" list,
1854 * and add the new property to the property list
1855 */
1856int of_update_property(struct device_node *np, struct property *newprop)
1857{
1858 struct property *oldprop;
1859 unsigned long flags;
1860 int rc;
1861
1862 if (!newprop->name)
1863 return -EINVAL;
1864
1865 mutex_lock(&of_mutex);
1866
1867 raw_spin_lock_irqsave(&devtree_lock, flags);
1868 rc = __of_update_property(np, newprop, &oldprop);
1869 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1870
1871 if (!rc)
1872 __of_update_property_sysfs(np, newprop, oldprop);
1873
1874 mutex_unlock(&of_mutex);
1875
1876 if (!rc)
1877 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1878
1879 return rc;
1880}
1881
1882static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1883 int id, const char *stem, int stem_len)
1884{
1885 ap->np = np;
1886 ap->id = id;
1887 strncpy(ap->stem, stem, stem_len);
1888 ap->stem[stem_len] = 0;
1889 list_add_tail(&ap->link, &aliases_lookup);
1890 pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n",
1891 ap->alias, ap->stem, ap->id, np);
1892}
1893
1894/**
1895 * of_alias_scan - Scan all properties of the 'aliases' node
1896 * @dt_alloc: An allocator that provides a virtual address to memory
1897 * for storing the resulting tree
1898 *
1899 * The function scans all the properties of the 'aliases' node and populates
1900 * the global lookup table with the properties. It returns the
1901 * number of alias properties found, or an error code in case of failure.
1902 */
1903void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1904{
1905 struct property *pp;
1906
1907 of_aliases = of_find_node_by_path("/aliases");
1908 of_chosen = of_find_node_by_path("/chosen");
1909 if (of_chosen == NULL)
1910 of_chosen = of_find_node_by_path("/chosen@0");
1911
1912 if (of_chosen) {
1913 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1914 const char *name = NULL;
1915
1916 if (of_property_read_string(of_chosen, "stdout-path", &name))
1917 of_property_read_string(of_chosen, "linux,stdout-path",
1918 &name);
1919 if (IS_ENABLED(CONFIG_PPC) && !name)
1920 of_property_read_string(of_aliases, "stdout", &name);
1921 if (name)
1922 of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
1923 if (of_stdout)
1924 of_stdout->fwnode.flags |= FWNODE_FLAG_BEST_EFFORT;
1925 }
1926
1927 if (!of_aliases)
1928 return;
1929
1930 for_each_property_of_node(of_aliases, pp) {
1931 const char *start = pp->name;
1932 const char *end = start + strlen(start);
1933 struct device_node *np;
1934 struct alias_prop *ap;
1935 int id, len;
1936
1937 /* Skip those we do not want to proceed */
1938 if (!strcmp(pp->name, "name") ||
1939 !strcmp(pp->name, "phandle") ||
1940 !strcmp(pp->name, "linux,phandle"))
1941 continue;
1942
1943 np = of_find_node_by_path(pp->value);
1944 if (!np)
1945 continue;
1946
1947 /* walk the alias backwards to extract the id and work out
1948 * the 'stem' string */
1949 while (isdigit(*(end-1)) && end > start)
1950 end--;
1951 len = end - start;
1952
1953 if (kstrtoint(end, 10, &id) < 0)
1954 continue;
1955
1956 /* Allocate an alias_prop with enough space for the stem */
1957 ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap));
1958 if (!ap)
1959 continue;
1960 memset(ap, 0, sizeof(*ap) + len + 1);
1961 ap->alias = start;
1962 of_alias_add(ap, np, id, start, len);
1963 }
1964}
1965
1966/**
1967 * of_alias_get_id - Get alias id for the given device_node
1968 * @np: Pointer to the given device_node
1969 * @stem: Alias stem of the given device_node
1970 *
1971 * The function travels the lookup table to get the alias id for the given
1972 * device_node and alias stem.
1973 *
1974 * Return: The alias id if found.
1975 */
1976int of_alias_get_id(struct device_node *np, const char *stem)
1977{
1978 struct alias_prop *app;
1979 int id = -ENODEV;
1980
1981 mutex_lock(&of_mutex);
1982 list_for_each_entry(app, &aliases_lookup, link) {
1983 if (strcmp(app->stem, stem) != 0)
1984 continue;
1985
1986 if (np == app->np) {
1987 id = app->id;
1988 break;
1989 }
1990 }
1991 mutex_unlock(&of_mutex);
1992
1993 return id;
1994}
1995EXPORT_SYMBOL_GPL(of_alias_get_id);
1996
1997/**
1998 * of_alias_get_highest_id - Get highest alias id for the given stem
1999 * @stem: Alias stem to be examined
2000 *
2001 * The function travels the lookup table to get the highest alias id for the
2002 * given alias stem. It returns the alias id if found.
2003 */
2004int of_alias_get_highest_id(const char *stem)
2005{
2006 struct alias_prop *app;
2007 int id = -ENODEV;
2008
2009 mutex_lock(&of_mutex);
2010 list_for_each_entry(app, &aliases_lookup, link) {
2011 if (strcmp(app->stem, stem) != 0)
2012 continue;
2013
2014 if (app->id > id)
2015 id = app->id;
2016 }
2017 mutex_unlock(&of_mutex);
2018
2019 return id;
2020}
2021EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
2022
2023/**
2024 * of_console_check() - Test and setup console for DT setup
2025 * @dn: Pointer to device node
2026 * @name: Name to use for preferred console without index. ex. "ttyS"
2027 * @index: Index to use for preferred console.
2028 *
2029 * Check if the given device node matches the stdout-path property in the
2030 * /chosen node. If it does then register it as the preferred console.
2031 *
2032 * Return: TRUE if console successfully setup. Otherwise return FALSE.
2033 */
2034bool of_console_check(struct device_node *dn, char *name, int index)
2035{
2036 if (!dn || dn != of_stdout || console_set_on_cmdline)
2037 return false;
2038
2039 /*
2040 * XXX: cast `options' to char pointer to suppress complication
2041 * warnings: printk, UART and console drivers expect char pointer.
2042 */
2043 return !add_preferred_console(name, index, (char *)of_stdout_options);
2044}
2045EXPORT_SYMBOL_GPL(of_console_check);
2046
2047/**
2048 * of_find_next_cache_node - Find a node's subsidiary cache
2049 * @np: node of type "cpu" or "cache"
2050 *
2051 * Return: A node pointer with refcount incremented, use
2052 * of_node_put() on it when done. Caller should hold a reference
2053 * to np.
2054 */
2055struct device_node *of_find_next_cache_node(const struct device_node *np)
2056{
2057 struct device_node *child, *cache_node;
2058
2059 cache_node = of_parse_phandle(np, "l2-cache", 0);
2060 if (!cache_node)
2061 cache_node = of_parse_phandle(np, "next-level-cache", 0);
2062
2063 if (cache_node)
2064 return cache_node;
2065
2066 /* OF on pmac has nodes instead of properties named "l2-cache"
2067 * beneath CPU nodes.
2068 */
2069 if (IS_ENABLED(CONFIG_PPC_PMAC) && of_node_is_type(np, "cpu"))
2070 for_each_child_of_node(np, child)
2071 if (of_node_is_type(child, "cache"))
2072 return child;
2073
2074 return NULL;
2075}
2076
2077/**
2078 * of_find_last_cache_level - Find the level at which the last cache is
2079 * present for the given logical cpu
2080 *
2081 * @cpu: cpu number(logical index) for which the last cache level is needed
2082 *
2083 * Return: The level at which the last cache is present. It is exactly
2084 * same as the total number of cache levels for the given logical cpu.
2085 */
2086int of_find_last_cache_level(unsigned int cpu)
2087{
2088 u32 cache_level = 0;
2089 struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
2090
2091 while (np) {
2092 of_node_put(prev);
2093 prev = np;
2094 np = of_find_next_cache_node(np);
2095 }
2096
2097 of_property_read_u32(prev, "cache-level", &cache_level);
2098 of_node_put(prev);
2099
2100 return cache_level;
2101}
2102
2103/**
2104 * of_map_id - Translate an ID through a downstream mapping.
2105 * @np: root complex device node.
2106 * @id: device ID to map.
2107 * @map_name: property name of the map to use.
2108 * @map_mask_name: optional property name of the mask to use.
2109 * @target: optional pointer to a target device node.
2110 * @id_out: optional pointer to receive the translated ID.
2111 *
2112 * Given a device ID, look up the appropriate implementation-defined
2113 * platform ID and/or the target device which receives transactions on that
2114 * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
2115 * @id_out may be NULL if only the other is required. If @target points to
2116 * a non-NULL device node pointer, only entries targeting that node will be
2117 * matched; if it points to a NULL value, it will receive the device node of
2118 * the first matching target phandle, with a reference held.
2119 *
2120 * Return: 0 on success or a standard error code on failure.
2121 */
2122int of_map_id(struct device_node *np, u32 id,
2123 const char *map_name, const char *map_mask_name,
2124 struct device_node **target, u32 *id_out)
2125{
2126 u32 map_mask, masked_id;
2127 int map_len;
2128 const __be32 *map = NULL;
2129
2130 if (!np || !map_name || (!target && !id_out))
2131 return -EINVAL;
2132
2133 map = of_get_property(np, map_name, &map_len);
2134 if (!map) {
2135 if (target)
2136 return -ENODEV;
2137 /* Otherwise, no map implies no translation */
2138 *id_out = id;
2139 return 0;
2140 }
2141
2142 if (!map_len || map_len % (4 * sizeof(*map))) {
2143 pr_err("%pOF: Error: Bad %s length: %d\n", np,
2144 map_name, map_len);
2145 return -EINVAL;
2146 }
2147
2148 /* The default is to select all bits. */
2149 map_mask = 0xffffffff;
2150
2151 /*
2152 * Can be overridden by "{iommu,msi}-map-mask" property.
2153 * If of_property_read_u32() fails, the default is used.
2154 */
2155 if (map_mask_name)
2156 of_property_read_u32(np, map_mask_name, &map_mask);
2157
2158 masked_id = map_mask & id;
2159 for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
2160 struct device_node *phandle_node;
2161 u32 id_base = be32_to_cpup(map + 0);
2162 u32 phandle = be32_to_cpup(map + 1);
2163 u32 out_base = be32_to_cpup(map + 2);
2164 u32 id_len = be32_to_cpup(map + 3);
2165
2166 if (id_base & ~map_mask) {
2167 pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores id-base (0x%x)\n",
2168 np, map_name, map_name,
2169 map_mask, id_base);
2170 return -EFAULT;
2171 }
2172
2173 if (masked_id < id_base || masked_id >= id_base + id_len)
2174 continue;
2175
2176 phandle_node = of_find_node_by_phandle(phandle);
2177 if (!phandle_node)
2178 return -ENODEV;
2179
2180 if (target) {
2181 if (*target)
2182 of_node_put(phandle_node);
2183 else
2184 *target = phandle_node;
2185
2186 if (*target != phandle_node)
2187 continue;
2188 }
2189
2190 if (id_out)
2191 *id_out = masked_id - id_base + out_base;
2192
2193 pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
2194 np, map_name, map_mask, id_base, out_base,
2195 id_len, id, masked_id - id_base + out_base);
2196 return 0;
2197 }
2198
2199 pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name,
2200 id, target && *target ? *target : NULL);
2201
2202 /* Bypasses translation */
2203 if (id_out)
2204 *id_out = id;
2205 return 0;
2206}
2207EXPORT_SYMBOL_GPL(of_map_id);
1/*
2 * Procedures for creating, accessing and interpreting the device tree.
3 *
4 * Paul Mackerras August 1996.
5 * Copyright (C) 1996-2005 Paul Mackerras.
6 *
7 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
8 * {engebret|bergner}@us.ibm.com
9 *
10 * Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
11 *
12 * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
13 * Grant Likely.
14 *
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
19 */
20
21#define pr_fmt(fmt) "OF: " fmt
22
23#include <linux/console.h>
24#include <linux/ctype.h>
25#include <linux/cpu.h>
26#include <linux/module.h>
27#include <linux/of.h>
28#include <linux/of_graph.h>
29#include <linux/spinlock.h>
30#include <linux/slab.h>
31#include <linux/string.h>
32#include <linux/proc_fs.h>
33
34#include "of_private.h"
35
36LIST_HEAD(aliases_lookup);
37
38struct device_node *of_root;
39EXPORT_SYMBOL(of_root);
40struct device_node *of_chosen;
41struct device_node *of_aliases;
42struct device_node *of_stdout;
43static const char *of_stdout_options;
44
45struct kset *of_kset;
46
47/*
48 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
49 * This mutex must be held whenever modifications are being made to the
50 * device tree. The of_{attach,detach}_node() and
51 * of_{add,remove,update}_property() helpers make sure this happens.
52 */
53DEFINE_MUTEX(of_mutex);
54
55/* use when traversing tree through the child, sibling,
56 * or parent members of struct device_node.
57 */
58DEFINE_RAW_SPINLOCK(devtree_lock);
59
60int of_n_addr_cells(struct device_node *np)
61{
62 const __be32 *ip;
63
64 do {
65 if (np->parent)
66 np = np->parent;
67 ip = of_get_property(np, "#address-cells", NULL);
68 if (ip)
69 return be32_to_cpup(ip);
70 } while (np->parent);
71 /* No #address-cells property for the root node */
72 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
73}
74EXPORT_SYMBOL(of_n_addr_cells);
75
76int of_n_size_cells(struct device_node *np)
77{
78 const __be32 *ip;
79
80 do {
81 if (np->parent)
82 np = np->parent;
83 ip = of_get_property(np, "#size-cells", NULL);
84 if (ip)
85 return be32_to_cpup(ip);
86 } while (np->parent);
87 /* No #size-cells property for the root node */
88 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
89}
90EXPORT_SYMBOL(of_n_size_cells);
91
92#ifdef CONFIG_NUMA
93int __weak of_node_to_nid(struct device_node *np)
94{
95 return NUMA_NO_NODE;
96}
97#endif
98
99#ifndef CONFIG_OF_DYNAMIC
100static void of_node_release(struct kobject *kobj)
101{
102 /* Without CONFIG_OF_DYNAMIC, no nodes gets freed */
103}
104#endif /* CONFIG_OF_DYNAMIC */
105
106struct kobj_type of_node_ktype = {
107 .release = of_node_release,
108};
109
110static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj,
111 struct bin_attribute *bin_attr, char *buf,
112 loff_t offset, size_t count)
113{
114 struct property *pp = container_of(bin_attr, struct property, attr);
115 return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length);
116}
117
118/* always return newly allocated name, caller must free after use */
119static const char *safe_name(struct kobject *kobj, const char *orig_name)
120{
121 const char *name = orig_name;
122 struct kernfs_node *kn;
123 int i = 0;
124
125 /* don't be a hero. After 16 tries give up */
126 while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) {
127 sysfs_put(kn);
128 if (name != orig_name)
129 kfree(name);
130 name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i);
131 }
132
133 if (name == orig_name) {
134 name = kstrdup(orig_name, GFP_KERNEL);
135 } else {
136 pr_warn("Duplicate name in %s, renamed to \"%s\"\n",
137 kobject_name(kobj), name);
138 }
139 return name;
140}
141
142int __of_add_property_sysfs(struct device_node *np, struct property *pp)
143{
144 int rc;
145
146 /* Important: Don't leak passwords */
147 bool secure = strncmp(pp->name, "security-", 9) == 0;
148
149 if (!IS_ENABLED(CONFIG_SYSFS))
150 return 0;
151
152 if (!of_kset || !of_node_is_attached(np))
153 return 0;
154
155 sysfs_bin_attr_init(&pp->attr);
156 pp->attr.attr.name = safe_name(&np->kobj, pp->name);
157 pp->attr.attr.mode = secure ? S_IRUSR : S_IRUGO;
158 pp->attr.size = secure ? 0 : pp->length;
159 pp->attr.read = of_node_property_read;
160
161 rc = sysfs_create_bin_file(&np->kobj, &pp->attr);
162 WARN(rc, "error adding attribute %s to node %s\n", pp->name, np->full_name);
163 return rc;
164}
165
166int __of_attach_node_sysfs(struct device_node *np)
167{
168 const char *name;
169 struct kobject *parent;
170 struct property *pp;
171 int rc;
172
173 if (!IS_ENABLED(CONFIG_SYSFS))
174 return 0;
175
176 if (!of_kset)
177 return 0;
178
179 np->kobj.kset = of_kset;
180 if (!np->parent) {
181 /* Nodes without parents are new top level trees */
182 name = safe_name(&of_kset->kobj, "base");
183 parent = NULL;
184 } else {
185 name = safe_name(&np->parent->kobj, kbasename(np->full_name));
186 parent = &np->parent->kobj;
187 }
188 if (!name)
189 return -ENOMEM;
190 rc = kobject_add(&np->kobj, parent, "%s", name);
191 kfree(name);
192 if (rc)
193 return rc;
194
195 for_each_property_of_node(np, pp)
196 __of_add_property_sysfs(np, pp);
197
198 return 0;
199}
200
201void __init of_core_init(void)
202{
203 struct device_node *np;
204
205 /* Create the kset, and register existing nodes */
206 mutex_lock(&of_mutex);
207 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
208 if (!of_kset) {
209 mutex_unlock(&of_mutex);
210 pr_err("failed to register existing nodes\n");
211 return;
212 }
213 for_each_of_allnodes(np)
214 __of_attach_node_sysfs(np);
215 mutex_unlock(&of_mutex);
216
217 /* Symlink in /proc as required by userspace ABI */
218 if (of_root)
219 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
220}
221
222static struct property *__of_find_property(const struct device_node *np,
223 const char *name, int *lenp)
224{
225 struct property *pp;
226
227 if (!np)
228 return NULL;
229
230 for (pp = np->properties; pp; pp = pp->next) {
231 if (of_prop_cmp(pp->name, name) == 0) {
232 if (lenp)
233 *lenp = pp->length;
234 break;
235 }
236 }
237
238 return pp;
239}
240
241struct property *of_find_property(const struct device_node *np,
242 const char *name,
243 int *lenp)
244{
245 struct property *pp;
246 unsigned long flags;
247
248 raw_spin_lock_irqsave(&devtree_lock, flags);
249 pp = __of_find_property(np, name, lenp);
250 raw_spin_unlock_irqrestore(&devtree_lock, flags);
251
252 return pp;
253}
254EXPORT_SYMBOL(of_find_property);
255
256struct device_node *__of_find_all_nodes(struct device_node *prev)
257{
258 struct device_node *np;
259 if (!prev) {
260 np = of_root;
261 } else if (prev->child) {
262 np = prev->child;
263 } else {
264 /* Walk back up looking for a sibling, or the end of the structure */
265 np = prev;
266 while (np->parent && !np->sibling)
267 np = np->parent;
268 np = np->sibling; /* Might be null at the end of the tree */
269 }
270 return np;
271}
272
273/**
274 * of_find_all_nodes - Get next node in global list
275 * @prev: Previous node or NULL to start iteration
276 * of_node_put() will be called on it
277 *
278 * Returns a node pointer with refcount incremented, use
279 * of_node_put() on it when done.
280 */
281struct device_node *of_find_all_nodes(struct device_node *prev)
282{
283 struct device_node *np;
284 unsigned long flags;
285
286 raw_spin_lock_irqsave(&devtree_lock, flags);
287 np = __of_find_all_nodes(prev);
288 of_node_get(np);
289 of_node_put(prev);
290 raw_spin_unlock_irqrestore(&devtree_lock, flags);
291 return np;
292}
293EXPORT_SYMBOL(of_find_all_nodes);
294
295/*
296 * Find a property with a given name for a given node
297 * and return the value.
298 */
299const void *__of_get_property(const struct device_node *np,
300 const char *name, int *lenp)
301{
302 struct property *pp = __of_find_property(np, name, lenp);
303
304 return pp ? pp->value : NULL;
305}
306
307/*
308 * Find a property with a given name for a given node
309 * and return the value.
310 */
311const void *of_get_property(const struct device_node *np, const char *name,
312 int *lenp)
313{
314 struct property *pp = of_find_property(np, name, lenp);
315
316 return pp ? pp->value : NULL;
317}
318EXPORT_SYMBOL(of_get_property);
319
320/*
321 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
322 *
323 * @cpu: logical cpu index of a core/thread
324 * @phys_id: physical identifier of a core/thread
325 *
326 * CPU logical to physical index mapping is architecture specific.
327 * However this __weak function provides a default match of physical
328 * id to logical cpu index. phys_id provided here is usually values read
329 * from the device tree which must match the hardware internal registers.
330 *
331 * Returns true if the physical identifier and the logical cpu index
332 * correspond to the same core/thread, false otherwise.
333 */
334bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
335{
336 return (u32)phys_id == cpu;
337}
338
339/**
340 * Checks if the given "prop_name" property holds the physical id of the
341 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
342 * NULL, local thread number within the core is returned in it.
343 */
344static bool __of_find_n_match_cpu_property(struct device_node *cpun,
345 const char *prop_name, int cpu, unsigned int *thread)
346{
347 const __be32 *cell;
348 int ac, prop_len, tid;
349 u64 hwid;
350
351 ac = of_n_addr_cells(cpun);
352 cell = of_get_property(cpun, prop_name, &prop_len);
353 if (!cell || !ac)
354 return false;
355 prop_len /= sizeof(*cell) * ac;
356 for (tid = 0; tid < prop_len; tid++) {
357 hwid = of_read_number(cell, ac);
358 if (arch_match_cpu_phys_id(cpu, hwid)) {
359 if (thread)
360 *thread = tid;
361 return true;
362 }
363 cell += ac;
364 }
365 return false;
366}
367
368/*
369 * arch_find_n_match_cpu_physical_id - See if the given device node is
370 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
371 * else false. If 'thread' is non-NULL, the local thread number within the
372 * core is returned in it.
373 */
374bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
375 int cpu, unsigned int *thread)
376{
377 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
378 * for thread ids on PowerPC. If it doesn't exist fallback to
379 * standard "reg" property.
380 */
381 if (IS_ENABLED(CONFIG_PPC) &&
382 __of_find_n_match_cpu_property(cpun,
383 "ibm,ppc-interrupt-server#s",
384 cpu, thread))
385 return true;
386
387 return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
388}
389
390/**
391 * of_get_cpu_node - Get device node associated with the given logical CPU
392 *
393 * @cpu: CPU number(logical index) for which device node is required
394 * @thread: if not NULL, local thread number within the physical core is
395 * returned
396 *
397 * The main purpose of this function is to retrieve the device node for the
398 * given logical CPU index. It should be used to initialize the of_node in
399 * cpu device. Once of_node in cpu device is populated, all the further
400 * references can use that instead.
401 *
402 * CPU logical to physical index mapping is architecture specific and is built
403 * before booting secondary cores. This function uses arch_match_cpu_phys_id
404 * which can be overridden by architecture specific implementation.
405 *
406 * Returns a node pointer for the logical cpu with refcount incremented, use
407 * of_node_put() on it when done. Returns NULL if not found.
408 */
409struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
410{
411 struct device_node *cpun;
412
413 for_each_node_by_type(cpun, "cpu") {
414 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
415 return cpun;
416 }
417 return NULL;
418}
419EXPORT_SYMBOL(of_get_cpu_node);
420
421/**
422 * __of_device_is_compatible() - Check if the node matches given constraints
423 * @device: pointer to node
424 * @compat: required compatible string, NULL or "" for any match
425 * @type: required device_type value, NULL or "" for any match
426 * @name: required node name, NULL or "" for any match
427 *
428 * Checks if the given @compat, @type and @name strings match the
429 * properties of the given @device. A constraints can be skipped by
430 * passing NULL or an empty string as the constraint.
431 *
432 * Returns 0 for no match, and a positive integer on match. The return
433 * value is a relative score with larger values indicating better
434 * matches. The score is weighted for the most specific compatible value
435 * to get the highest score. Matching type is next, followed by matching
436 * name. Practically speaking, this results in the following priority
437 * order for matches:
438 *
439 * 1. specific compatible && type && name
440 * 2. specific compatible && type
441 * 3. specific compatible && name
442 * 4. specific compatible
443 * 5. general compatible && type && name
444 * 6. general compatible && type
445 * 7. general compatible && name
446 * 8. general compatible
447 * 9. type && name
448 * 10. type
449 * 11. name
450 */
451static int __of_device_is_compatible(const struct device_node *device,
452 const char *compat, const char *type, const char *name)
453{
454 struct property *prop;
455 const char *cp;
456 int index = 0, score = 0;
457
458 /* Compatible match has highest priority */
459 if (compat && compat[0]) {
460 prop = __of_find_property(device, "compatible", NULL);
461 for (cp = of_prop_next_string(prop, NULL); cp;
462 cp = of_prop_next_string(prop, cp), index++) {
463 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
464 score = INT_MAX/2 - (index << 2);
465 break;
466 }
467 }
468 if (!score)
469 return 0;
470 }
471
472 /* Matching type is better than matching name */
473 if (type && type[0]) {
474 if (!device->type || of_node_cmp(type, device->type))
475 return 0;
476 score += 2;
477 }
478
479 /* Matching name is a bit better than not */
480 if (name && name[0]) {
481 if (!device->name || of_node_cmp(name, device->name))
482 return 0;
483 score++;
484 }
485
486 return score;
487}
488
489/** Checks if the given "compat" string matches one of the strings in
490 * the device's "compatible" property
491 */
492int of_device_is_compatible(const struct device_node *device,
493 const char *compat)
494{
495 unsigned long flags;
496 int res;
497
498 raw_spin_lock_irqsave(&devtree_lock, flags);
499 res = __of_device_is_compatible(device, compat, NULL, NULL);
500 raw_spin_unlock_irqrestore(&devtree_lock, flags);
501 return res;
502}
503EXPORT_SYMBOL(of_device_is_compatible);
504
505/** Checks if the device is compatible with any of the entries in
506 * a NULL terminated array of strings. Returns the best match
507 * score or 0.
508 */
509int of_device_compatible_match(struct device_node *device,
510 const char *const *compat)
511{
512 unsigned int tmp, score = 0;
513
514 if (!compat)
515 return 0;
516
517 while (*compat) {
518 tmp = of_device_is_compatible(device, *compat);
519 if (tmp > score)
520 score = tmp;
521 compat++;
522 }
523
524 return score;
525}
526
527/**
528 * of_machine_is_compatible - Test root of device tree for a given compatible value
529 * @compat: compatible string to look for in root node's compatible property.
530 *
531 * Returns a positive integer if the root node has the given value in its
532 * compatible property.
533 */
534int of_machine_is_compatible(const char *compat)
535{
536 struct device_node *root;
537 int rc = 0;
538
539 root = of_find_node_by_path("/");
540 if (root) {
541 rc = of_device_is_compatible(root, compat);
542 of_node_put(root);
543 }
544 return rc;
545}
546EXPORT_SYMBOL(of_machine_is_compatible);
547
548/**
549 * __of_device_is_available - check if a device is available for use
550 *
551 * @device: Node to check for availability, with locks already held
552 *
553 * Returns true if the status property is absent or set to "okay" or "ok",
554 * false otherwise
555 */
556static bool __of_device_is_available(const struct device_node *device)
557{
558 const char *status;
559 int statlen;
560
561 if (!device)
562 return false;
563
564 status = __of_get_property(device, "status", &statlen);
565 if (status == NULL)
566 return true;
567
568 if (statlen > 0) {
569 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
570 return true;
571 }
572
573 return false;
574}
575
576/**
577 * of_device_is_available - check if a device is available for use
578 *
579 * @device: Node to check for availability
580 *
581 * Returns true if the status property is absent or set to "okay" or "ok",
582 * false otherwise
583 */
584bool of_device_is_available(const struct device_node *device)
585{
586 unsigned long flags;
587 bool res;
588
589 raw_spin_lock_irqsave(&devtree_lock, flags);
590 res = __of_device_is_available(device);
591 raw_spin_unlock_irqrestore(&devtree_lock, flags);
592 return res;
593
594}
595EXPORT_SYMBOL(of_device_is_available);
596
597/**
598 * of_device_is_big_endian - check if a device has BE registers
599 *
600 * @device: Node to check for endianness
601 *
602 * Returns true if the device has a "big-endian" property, or if the kernel
603 * was compiled for BE *and* the device has a "native-endian" property.
604 * Returns false otherwise.
605 *
606 * Callers would nominally use ioread32be/iowrite32be if
607 * of_device_is_big_endian() == true, or readl/writel otherwise.
608 */
609bool of_device_is_big_endian(const struct device_node *device)
610{
611 if (of_property_read_bool(device, "big-endian"))
612 return true;
613 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
614 of_property_read_bool(device, "native-endian"))
615 return true;
616 return false;
617}
618EXPORT_SYMBOL(of_device_is_big_endian);
619
620/**
621 * of_get_parent - Get a node's parent if any
622 * @node: Node to get parent
623 *
624 * Returns a node pointer with refcount incremented, use
625 * of_node_put() on it when done.
626 */
627struct device_node *of_get_parent(const struct device_node *node)
628{
629 struct device_node *np;
630 unsigned long flags;
631
632 if (!node)
633 return NULL;
634
635 raw_spin_lock_irqsave(&devtree_lock, flags);
636 np = of_node_get(node->parent);
637 raw_spin_unlock_irqrestore(&devtree_lock, flags);
638 return np;
639}
640EXPORT_SYMBOL(of_get_parent);
641
642/**
643 * of_get_next_parent - Iterate to a node's parent
644 * @node: Node to get parent of
645 *
646 * This is like of_get_parent() except that it drops the
647 * refcount on the passed node, making it suitable for iterating
648 * through a node's parents.
649 *
650 * Returns a node pointer with refcount incremented, use
651 * of_node_put() on it when done.
652 */
653struct device_node *of_get_next_parent(struct device_node *node)
654{
655 struct device_node *parent;
656 unsigned long flags;
657
658 if (!node)
659 return NULL;
660
661 raw_spin_lock_irqsave(&devtree_lock, flags);
662 parent = of_node_get(node->parent);
663 of_node_put(node);
664 raw_spin_unlock_irqrestore(&devtree_lock, flags);
665 return parent;
666}
667EXPORT_SYMBOL(of_get_next_parent);
668
669static struct device_node *__of_get_next_child(const struct device_node *node,
670 struct device_node *prev)
671{
672 struct device_node *next;
673
674 if (!node)
675 return NULL;
676
677 next = prev ? prev->sibling : node->child;
678 for (; next; next = next->sibling)
679 if (of_node_get(next))
680 break;
681 of_node_put(prev);
682 return next;
683}
684#define __for_each_child_of_node(parent, child) \
685 for (child = __of_get_next_child(parent, NULL); child != NULL; \
686 child = __of_get_next_child(parent, child))
687
688/**
689 * of_get_next_child - Iterate a node childs
690 * @node: parent node
691 * @prev: previous child of the parent node, or NULL to get first
692 *
693 * Returns a node pointer with refcount incremented, use of_node_put() on
694 * it when done. Returns NULL when prev is the last child. Decrements the
695 * refcount of prev.
696 */
697struct device_node *of_get_next_child(const struct device_node *node,
698 struct device_node *prev)
699{
700 struct device_node *next;
701 unsigned long flags;
702
703 raw_spin_lock_irqsave(&devtree_lock, flags);
704 next = __of_get_next_child(node, prev);
705 raw_spin_unlock_irqrestore(&devtree_lock, flags);
706 return next;
707}
708EXPORT_SYMBOL(of_get_next_child);
709
710/**
711 * of_get_next_available_child - Find the next available child node
712 * @node: parent node
713 * @prev: previous child of the parent node, or NULL to get first
714 *
715 * This function is like of_get_next_child(), except that it
716 * automatically skips any disabled nodes (i.e. status = "disabled").
717 */
718struct device_node *of_get_next_available_child(const struct device_node *node,
719 struct device_node *prev)
720{
721 struct device_node *next;
722 unsigned long flags;
723
724 if (!node)
725 return NULL;
726
727 raw_spin_lock_irqsave(&devtree_lock, flags);
728 next = prev ? prev->sibling : node->child;
729 for (; next; next = next->sibling) {
730 if (!__of_device_is_available(next))
731 continue;
732 if (of_node_get(next))
733 break;
734 }
735 of_node_put(prev);
736 raw_spin_unlock_irqrestore(&devtree_lock, flags);
737 return next;
738}
739EXPORT_SYMBOL(of_get_next_available_child);
740
741/**
742 * of_get_child_by_name - Find the child node by name for a given parent
743 * @node: parent node
744 * @name: child name to look for.
745 *
746 * This function looks for child node for given matching name
747 *
748 * Returns a node pointer if found, with refcount incremented, use
749 * of_node_put() on it when done.
750 * Returns NULL if node is not found.
751 */
752struct device_node *of_get_child_by_name(const struct device_node *node,
753 const char *name)
754{
755 struct device_node *child;
756
757 for_each_child_of_node(node, child)
758 if (child->name && (of_node_cmp(child->name, name) == 0))
759 break;
760 return child;
761}
762EXPORT_SYMBOL(of_get_child_by_name);
763
764static struct device_node *__of_find_node_by_path(struct device_node *parent,
765 const char *path)
766{
767 struct device_node *child;
768 int len;
769
770 len = strcspn(path, "/:");
771 if (!len)
772 return NULL;
773
774 __for_each_child_of_node(parent, child) {
775 const char *name = strrchr(child->full_name, '/');
776 if (WARN(!name, "malformed device_node %s\n", child->full_name))
777 continue;
778 name++;
779 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
780 return child;
781 }
782 return NULL;
783}
784
785/**
786 * of_find_node_opts_by_path - Find a node matching a full OF path
787 * @path: Either the full path to match, or if the path does not
788 * start with '/', the name of a property of the /aliases
789 * node (an alias). In the case of an alias, the node
790 * matching the alias' value will be returned.
791 * @opts: Address of a pointer into which to store the start of
792 * an options string appended to the end of the path with
793 * a ':' separator.
794 *
795 * Valid paths:
796 * /foo/bar Full path
797 * foo Valid alias
798 * foo/bar Valid alias + relative path
799 *
800 * Returns a node pointer with refcount incremented, use
801 * of_node_put() on it when done.
802 */
803struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
804{
805 struct device_node *np = NULL;
806 struct property *pp;
807 unsigned long flags;
808 const char *separator = strchr(path, ':');
809
810 if (opts)
811 *opts = separator ? separator + 1 : NULL;
812
813 if (strcmp(path, "/") == 0)
814 return of_node_get(of_root);
815
816 /* The path could begin with an alias */
817 if (*path != '/') {
818 int len;
819 const char *p = separator;
820
821 if (!p)
822 p = strchrnul(path, '/');
823 len = p - path;
824
825 /* of_aliases must not be NULL */
826 if (!of_aliases)
827 return NULL;
828
829 for_each_property_of_node(of_aliases, pp) {
830 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
831 np = of_find_node_by_path(pp->value);
832 break;
833 }
834 }
835 if (!np)
836 return NULL;
837 path = p;
838 }
839
840 /* Step down the tree matching path components */
841 raw_spin_lock_irqsave(&devtree_lock, flags);
842 if (!np)
843 np = of_node_get(of_root);
844 while (np && *path == '/') {
845 path++; /* Increment past '/' delimiter */
846 np = __of_find_node_by_path(np, path);
847 path = strchrnul(path, '/');
848 if (separator && separator < path)
849 break;
850 }
851 raw_spin_unlock_irqrestore(&devtree_lock, flags);
852 return np;
853}
854EXPORT_SYMBOL(of_find_node_opts_by_path);
855
856/**
857 * of_find_node_by_name - Find a node by its "name" property
858 * @from: The node to start searching from or NULL, the node
859 * you pass will not be searched, only the next one
860 * will; typically, you pass what the previous call
861 * returned. of_node_put() will be called on it
862 * @name: The name string to match against
863 *
864 * Returns a node pointer with refcount incremented, use
865 * of_node_put() on it when done.
866 */
867struct device_node *of_find_node_by_name(struct device_node *from,
868 const char *name)
869{
870 struct device_node *np;
871 unsigned long flags;
872
873 raw_spin_lock_irqsave(&devtree_lock, flags);
874 for_each_of_allnodes_from(from, np)
875 if (np->name && (of_node_cmp(np->name, name) == 0)
876 && of_node_get(np))
877 break;
878 of_node_put(from);
879 raw_spin_unlock_irqrestore(&devtree_lock, flags);
880 return np;
881}
882EXPORT_SYMBOL(of_find_node_by_name);
883
884/**
885 * of_find_node_by_type - Find a node by its "device_type" property
886 * @from: The node to start searching from, or NULL to start searching
887 * the entire device tree. The node you pass will not be
888 * searched, only the next one will; typically, you pass
889 * what the previous call returned. of_node_put() will be
890 * called on from for you.
891 * @type: The type string to match against
892 *
893 * Returns a node pointer with refcount incremented, use
894 * of_node_put() on it when done.
895 */
896struct device_node *of_find_node_by_type(struct device_node *from,
897 const char *type)
898{
899 struct device_node *np;
900 unsigned long flags;
901
902 raw_spin_lock_irqsave(&devtree_lock, flags);
903 for_each_of_allnodes_from(from, np)
904 if (np->type && (of_node_cmp(np->type, type) == 0)
905 && of_node_get(np))
906 break;
907 of_node_put(from);
908 raw_spin_unlock_irqrestore(&devtree_lock, flags);
909 return np;
910}
911EXPORT_SYMBOL(of_find_node_by_type);
912
913/**
914 * of_find_compatible_node - Find a node based on type and one of the
915 * tokens in its "compatible" property
916 * @from: The node to start searching from or NULL, the node
917 * you pass will not be searched, only the next one
918 * will; typically, you pass what the previous call
919 * returned. of_node_put() will be called on it
920 * @type: The type string to match "device_type" or NULL to ignore
921 * @compatible: The string to match to one of the tokens in the device
922 * "compatible" list.
923 *
924 * Returns a node pointer with refcount incremented, use
925 * of_node_put() on it when done.
926 */
927struct device_node *of_find_compatible_node(struct device_node *from,
928 const char *type, const char *compatible)
929{
930 struct device_node *np;
931 unsigned long flags;
932
933 raw_spin_lock_irqsave(&devtree_lock, flags);
934 for_each_of_allnodes_from(from, np)
935 if (__of_device_is_compatible(np, compatible, type, NULL) &&
936 of_node_get(np))
937 break;
938 of_node_put(from);
939 raw_spin_unlock_irqrestore(&devtree_lock, flags);
940 return np;
941}
942EXPORT_SYMBOL(of_find_compatible_node);
943
944/**
945 * of_find_node_with_property - Find a node which has a property with
946 * the given name.
947 * @from: The node to start searching from or NULL, the node
948 * you pass will not be searched, only the next one
949 * will; typically, you pass what the previous call
950 * returned. of_node_put() will be called on it
951 * @prop_name: The name of the property to look for.
952 *
953 * Returns a node pointer with refcount incremented, use
954 * of_node_put() on it when done.
955 */
956struct device_node *of_find_node_with_property(struct device_node *from,
957 const char *prop_name)
958{
959 struct device_node *np;
960 struct property *pp;
961 unsigned long flags;
962
963 raw_spin_lock_irqsave(&devtree_lock, flags);
964 for_each_of_allnodes_from(from, np) {
965 for (pp = np->properties; pp; pp = pp->next) {
966 if (of_prop_cmp(pp->name, prop_name) == 0) {
967 of_node_get(np);
968 goto out;
969 }
970 }
971 }
972out:
973 of_node_put(from);
974 raw_spin_unlock_irqrestore(&devtree_lock, flags);
975 return np;
976}
977EXPORT_SYMBOL(of_find_node_with_property);
978
979static
980const struct of_device_id *__of_match_node(const struct of_device_id *matches,
981 const struct device_node *node)
982{
983 const struct of_device_id *best_match = NULL;
984 int score, best_score = 0;
985
986 if (!matches)
987 return NULL;
988
989 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
990 score = __of_device_is_compatible(node, matches->compatible,
991 matches->type, matches->name);
992 if (score > best_score) {
993 best_match = matches;
994 best_score = score;
995 }
996 }
997
998 return best_match;
999}
1000
1001/**
1002 * of_match_node - Tell if a device_node has a matching of_match structure
1003 * @matches: array of of device match structures to search in
1004 * @node: the of device structure to match against
1005 *
1006 * Low level utility function used by device matching.
1007 */
1008const struct of_device_id *of_match_node(const struct of_device_id *matches,
1009 const struct device_node *node)
1010{
1011 const struct of_device_id *match;
1012 unsigned long flags;
1013
1014 raw_spin_lock_irqsave(&devtree_lock, flags);
1015 match = __of_match_node(matches, node);
1016 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1017 return match;
1018}
1019EXPORT_SYMBOL(of_match_node);
1020
1021/**
1022 * of_find_matching_node_and_match - Find a node based on an of_device_id
1023 * match table.
1024 * @from: The node to start searching from or NULL, the node
1025 * you pass will not be searched, only the next one
1026 * will; typically, you pass what the previous call
1027 * returned. of_node_put() will be called on it
1028 * @matches: array of of device match structures to search in
1029 * @match Updated to point at the matches entry which matched
1030 *
1031 * Returns a node pointer with refcount incremented, use
1032 * of_node_put() on it when done.
1033 */
1034struct device_node *of_find_matching_node_and_match(struct device_node *from,
1035 const struct of_device_id *matches,
1036 const struct of_device_id **match)
1037{
1038 struct device_node *np;
1039 const struct of_device_id *m;
1040 unsigned long flags;
1041
1042 if (match)
1043 *match = NULL;
1044
1045 raw_spin_lock_irqsave(&devtree_lock, flags);
1046 for_each_of_allnodes_from(from, np) {
1047 m = __of_match_node(matches, np);
1048 if (m && of_node_get(np)) {
1049 if (match)
1050 *match = m;
1051 break;
1052 }
1053 }
1054 of_node_put(from);
1055 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1056 return np;
1057}
1058EXPORT_SYMBOL(of_find_matching_node_and_match);
1059
1060/**
1061 * of_modalias_node - Lookup appropriate modalias for a device node
1062 * @node: pointer to a device tree node
1063 * @modalias: Pointer to buffer that modalias value will be copied into
1064 * @len: Length of modalias value
1065 *
1066 * Based on the value of the compatible property, this routine will attempt
1067 * to choose an appropriate modalias value for a particular device tree node.
1068 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1069 * from the first entry in the compatible list property.
1070 *
1071 * This routine returns 0 on success, <0 on failure.
1072 */
1073int of_modalias_node(struct device_node *node, char *modalias, int len)
1074{
1075 const char *compatible, *p;
1076 int cplen;
1077
1078 compatible = of_get_property(node, "compatible", &cplen);
1079 if (!compatible || strlen(compatible) > cplen)
1080 return -ENODEV;
1081 p = strchr(compatible, ',');
1082 strlcpy(modalias, p ? p + 1 : compatible, len);
1083 return 0;
1084}
1085EXPORT_SYMBOL_GPL(of_modalias_node);
1086
1087/**
1088 * of_find_node_by_phandle - Find a node given a phandle
1089 * @handle: phandle of the node to find
1090 *
1091 * Returns a node pointer with refcount incremented, use
1092 * of_node_put() on it when done.
1093 */
1094struct device_node *of_find_node_by_phandle(phandle handle)
1095{
1096 struct device_node *np;
1097 unsigned long flags;
1098
1099 if (!handle)
1100 return NULL;
1101
1102 raw_spin_lock_irqsave(&devtree_lock, flags);
1103 for_each_of_allnodes(np)
1104 if (np->phandle == handle)
1105 break;
1106 of_node_get(np);
1107 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1108 return np;
1109}
1110EXPORT_SYMBOL(of_find_node_by_phandle);
1111
1112/**
1113 * of_property_count_elems_of_size - Count the number of elements in a property
1114 *
1115 * @np: device node from which the property value is to be read.
1116 * @propname: name of the property to be searched.
1117 * @elem_size: size of the individual element
1118 *
1119 * Search for a property in a device node and count the number of elements of
1120 * size elem_size in it. Returns number of elements on sucess, -EINVAL if the
1121 * property does not exist or its length does not match a multiple of elem_size
1122 * and -ENODATA if the property does not have a value.
1123 */
1124int of_property_count_elems_of_size(const struct device_node *np,
1125 const char *propname, int elem_size)
1126{
1127 struct property *prop = of_find_property(np, propname, NULL);
1128
1129 if (!prop)
1130 return -EINVAL;
1131 if (!prop->value)
1132 return -ENODATA;
1133
1134 if (prop->length % elem_size != 0) {
1135 pr_err("size of %s in node %s is not a multiple of %d\n",
1136 propname, np->full_name, elem_size);
1137 return -EINVAL;
1138 }
1139
1140 return prop->length / elem_size;
1141}
1142EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
1143
1144/**
1145 * of_find_property_value_of_size
1146 *
1147 * @np: device node from which the property value is to be read.
1148 * @propname: name of the property to be searched.
1149 * @min: minimum allowed length of property value
1150 * @max: maximum allowed length of property value (0 means unlimited)
1151 * @len: if !=NULL, actual length is written to here
1152 *
1153 * Search for a property in a device node and valid the requested size.
1154 * Returns the property value on success, -EINVAL if the property does not
1155 * exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
1156 * property data is too small or too large.
1157 *
1158 */
1159static void *of_find_property_value_of_size(const struct device_node *np,
1160 const char *propname, u32 min, u32 max, size_t *len)
1161{
1162 struct property *prop = of_find_property(np, propname, NULL);
1163
1164 if (!prop)
1165 return ERR_PTR(-EINVAL);
1166 if (!prop->value)
1167 return ERR_PTR(-ENODATA);
1168 if (prop->length < min)
1169 return ERR_PTR(-EOVERFLOW);
1170 if (max && prop->length > max)
1171 return ERR_PTR(-EOVERFLOW);
1172
1173 if (len)
1174 *len = prop->length;
1175
1176 return prop->value;
1177}
1178
1179/**
1180 * of_property_read_u32_index - Find and read a u32 from a multi-value property.
1181 *
1182 * @np: device node from which the property value is to be read.
1183 * @propname: name of the property to be searched.
1184 * @index: index of the u32 in the list of values
1185 * @out_value: pointer to return value, modified only if no error.
1186 *
1187 * Search for a property in a device node and read nth 32-bit value from
1188 * it. Returns 0 on success, -EINVAL if the property does not exist,
1189 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1190 * property data isn't large enough.
1191 *
1192 * The out_value is modified only if a valid u32 value can be decoded.
1193 */
1194int of_property_read_u32_index(const struct device_node *np,
1195 const char *propname,
1196 u32 index, u32 *out_value)
1197{
1198 const u32 *val = of_find_property_value_of_size(np, propname,
1199 ((index + 1) * sizeof(*out_value)),
1200 0,
1201 NULL);
1202
1203 if (IS_ERR(val))
1204 return PTR_ERR(val);
1205
1206 *out_value = be32_to_cpup(((__be32 *)val) + index);
1207 return 0;
1208}
1209EXPORT_SYMBOL_GPL(of_property_read_u32_index);
1210
1211/**
1212 * of_property_read_variable_u8_array - Find and read an array of u8 from a
1213 * property, with bounds on the minimum and maximum array size.
1214 *
1215 * @np: device node from which the property value is to be read.
1216 * @propname: name of the property to be searched.
1217 * @out_values: pointer to return value, modified only if return value is 0.
1218 * @sz_min: minimum number of array elements to read
1219 * @sz_max: maximum number of array elements to read, if zero there is no
1220 * upper limit on the number of elements in the dts entry but only
1221 * sz_min will be read.
1222 *
1223 * Search for a property in a device node and read 8-bit value(s) from
1224 * it. Returns number of elements read on success, -EINVAL if the property
1225 * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
1226 * if the property data is smaller than sz_min or longer than sz_max.
1227 *
1228 * dts entry of array should be like:
1229 * property = /bits/ 8 <0x50 0x60 0x70>;
1230 *
1231 * The out_values is modified only if a valid u8 value can be decoded.
1232 */
1233int of_property_read_variable_u8_array(const struct device_node *np,
1234 const char *propname, u8 *out_values,
1235 size_t sz_min, size_t sz_max)
1236{
1237 size_t sz, count;
1238 const u8 *val = of_find_property_value_of_size(np, propname,
1239 (sz_min * sizeof(*out_values)),
1240 (sz_max * sizeof(*out_values)),
1241 &sz);
1242
1243 if (IS_ERR(val))
1244 return PTR_ERR(val);
1245
1246 if (!sz_max)
1247 sz = sz_min;
1248 else
1249 sz /= sizeof(*out_values);
1250
1251 count = sz;
1252 while (count--)
1253 *out_values++ = *val++;
1254
1255 return sz;
1256}
1257EXPORT_SYMBOL_GPL(of_property_read_variable_u8_array);
1258
1259/**
1260 * of_property_read_variable_u16_array - Find and read an array of u16 from a
1261 * property, with bounds on the minimum and maximum array size.
1262 *
1263 * @np: device node from which the property value is to be read.
1264 * @propname: name of the property to be searched.
1265 * @out_values: pointer to return value, modified only if return value is 0.
1266 * @sz_min: minimum number of array elements to read
1267 * @sz_max: maximum number of array elements to read, if zero there is no
1268 * upper limit on the number of elements in the dts entry but only
1269 * sz_min will be read.
1270 *
1271 * Search for a property in a device node and read 16-bit value(s) from
1272 * it. Returns number of elements read on success, -EINVAL if the property
1273 * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
1274 * if the property data is smaller than sz_min or longer than sz_max.
1275 *
1276 * dts entry of array should be like:
1277 * property = /bits/ 16 <0x5000 0x6000 0x7000>;
1278 *
1279 * The out_values is modified only if a valid u16 value can be decoded.
1280 */
1281int of_property_read_variable_u16_array(const struct device_node *np,
1282 const char *propname, u16 *out_values,
1283 size_t sz_min, size_t sz_max)
1284{
1285 size_t sz, count;
1286 const __be16 *val = of_find_property_value_of_size(np, propname,
1287 (sz_min * sizeof(*out_values)),
1288 (sz_max * sizeof(*out_values)),
1289 &sz);
1290
1291 if (IS_ERR(val))
1292 return PTR_ERR(val);
1293
1294 if (!sz_max)
1295 sz = sz_min;
1296 else
1297 sz /= sizeof(*out_values);
1298
1299 count = sz;
1300 while (count--)
1301 *out_values++ = be16_to_cpup(val++);
1302
1303 return sz;
1304}
1305EXPORT_SYMBOL_GPL(of_property_read_variable_u16_array);
1306
1307/**
1308 * of_property_read_variable_u32_array - Find and read an array of 32 bit
1309 * integers from a property, with bounds on the minimum and maximum array size.
1310 *
1311 * @np: device node from which the property value is to be read.
1312 * @propname: name of the property to be searched.
1313 * @out_values: pointer to return value, modified only if return value is 0.
1314 * @sz_min: minimum number of array elements to read
1315 * @sz_max: maximum number of array elements to read, if zero there is no
1316 * upper limit on the number of elements in the dts entry but only
1317 * sz_min will be read.
1318 *
1319 * Search for a property in a device node and read 32-bit value(s) from
1320 * it. Returns number of elements read on success, -EINVAL if the property
1321 * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
1322 * if the property data is smaller than sz_min or longer than sz_max.
1323 *
1324 * The out_values is modified only if a valid u32 value can be decoded.
1325 */
1326int of_property_read_variable_u32_array(const struct device_node *np,
1327 const char *propname, u32 *out_values,
1328 size_t sz_min, size_t sz_max)
1329{
1330 size_t sz, count;
1331 const __be32 *val = of_find_property_value_of_size(np, propname,
1332 (sz_min * sizeof(*out_values)),
1333 (sz_max * sizeof(*out_values)),
1334 &sz);
1335
1336 if (IS_ERR(val))
1337 return PTR_ERR(val);
1338
1339 if (!sz_max)
1340 sz = sz_min;
1341 else
1342 sz /= sizeof(*out_values);
1343
1344 count = sz;
1345 while (count--)
1346 *out_values++ = be32_to_cpup(val++);
1347
1348 return sz;
1349}
1350EXPORT_SYMBOL_GPL(of_property_read_variable_u32_array);
1351
1352/**
1353 * of_property_read_u64 - Find and read a 64 bit integer from a property
1354 * @np: device node from which the property value is to be read.
1355 * @propname: name of the property to be searched.
1356 * @out_value: pointer to return value, modified only if return value is 0.
1357 *
1358 * Search for a property in a device node and read a 64-bit value from
1359 * it. Returns 0 on success, -EINVAL if the property does not exist,
1360 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1361 * property data isn't large enough.
1362 *
1363 * The out_value is modified only if a valid u64 value can be decoded.
1364 */
1365int of_property_read_u64(const struct device_node *np, const char *propname,
1366 u64 *out_value)
1367{
1368 const __be32 *val = of_find_property_value_of_size(np, propname,
1369 sizeof(*out_value),
1370 0,
1371 NULL);
1372
1373 if (IS_ERR(val))
1374 return PTR_ERR(val);
1375
1376 *out_value = of_read_number(val, 2);
1377 return 0;
1378}
1379EXPORT_SYMBOL_GPL(of_property_read_u64);
1380
1381/**
1382 * of_property_read_variable_u64_array - Find and read an array of 64 bit
1383 * integers from a property, with bounds on the minimum and maximum array size.
1384 *
1385 * @np: device node from which the property value is to be read.
1386 * @propname: name of the property to be searched.
1387 * @out_values: pointer to return value, modified only if return value is 0.
1388 * @sz_min: minimum number of array elements to read
1389 * @sz_max: maximum number of array elements to read, if zero there is no
1390 * upper limit on the number of elements in the dts entry but only
1391 * sz_min will be read.
1392 *
1393 * Search for a property in a device node and read 64-bit value(s) from
1394 * it. Returns number of elements read on success, -EINVAL if the property
1395 * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
1396 * if the property data is smaller than sz_min or longer than sz_max.
1397 *
1398 * The out_values is modified only if a valid u64 value can be decoded.
1399 */
1400int of_property_read_variable_u64_array(const struct device_node *np,
1401 const char *propname, u64 *out_values,
1402 size_t sz_min, size_t sz_max)
1403{
1404 size_t sz, count;
1405 const __be32 *val = of_find_property_value_of_size(np, propname,
1406 (sz_min * sizeof(*out_values)),
1407 (sz_max * sizeof(*out_values)),
1408 &sz);
1409
1410 if (IS_ERR(val))
1411 return PTR_ERR(val);
1412
1413 if (!sz_max)
1414 sz = sz_min;
1415 else
1416 sz /= sizeof(*out_values);
1417
1418 count = sz;
1419 while (count--) {
1420 *out_values++ = of_read_number(val, 2);
1421 val += 2;
1422 }
1423
1424 return sz;
1425}
1426EXPORT_SYMBOL_GPL(of_property_read_variable_u64_array);
1427
1428/**
1429 * of_property_read_string - Find and read a string from a property
1430 * @np: device node from which the property value is to be read.
1431 * @propname: name of the property to be searched.
1432 * @out_string: pointer to null terminated return string, modified only if
1433 * return value is 0.
1434 *
1435 * Search for a property in a device tree node and retrieve a null
1436 * terminated string value (pointer to data, not a copy). Returns 0 on
1437 * success, -EINVAL if the property does not exist, -ENODATA if property
1438 * does not have a value, and -EILSEQ if the string is not null-terminated
1439 * within the length of the property data.
1440 *
1441 * The out_string pointer is modified only if a valid string can be decoded.
1442 */
1443int of_property_read_string(const struct device_node *np, const char *propname,
1444 const char **out_string)
1445{
1446 const struct property *prop = of_find_property(np, propname, NULL);
1447 if (!prop)
1448 return -EINVAL;
1449 if (!prop->value)
1450 return -ENODATA;
1451 if (strnlen(prop->value, prop->length) >= prop->length)
1452 return -EILSEQ;
1453 *out_string = prop->value;
1454 return 0;
1455}
1456EXPORT_SYMBOL_GPL(of_property_read_string);
1457
1458/**
1459 * of_property_match_string() - Find string in a list and return index
1460 * @np: pointer to node containing string list property
1461 * @propname: string list property name
1462 * @string: pointer to string to search for in string list
1463 *
1464 * This function searches a string list property and returns the index
1465 * of a specific string value.
1466 */
1467int of_property_match_string(const struct device_node *np, const char *propname,
1468 const char *string)
1469{
1470 const struct property *prop = of_find_property(np, propname, NULL);
1471 size_t l;
1472 int i;
1473 const char *p, *end;
1474
1475 if (!prop)
1476 return -EINVAL;
1477 if (!prop->value)
1478 return -ENODATA;
1479
1480 p = prop->value;
1481 end = p + prop->length;
1482
1483 for (i = 0; p < end; i++, p += l) {
1484 l = strnlen(p, end - p) + 1;
1485 if (p + l > end)
1486 return -EILSEQ;
1487 pr_debug("comparing %s with %s\n", string, p);
1488 if (strcmp(string, p) == 0)
1489 return i; /* Found it; return index */
1490 }
1491 return -ENODATA;
1492}
1493EXPORT_SYMBOL_GPL(of_property_match_string);
1494
1495/**
1496 * of_property_read_string_helper() - Utility helper for parsing string properties
1497 * @np: device node from which the property value is to be read.
1498 * @propname: name of the property to be searched.
1499 * @out_strs: output array of string pointers.
1500 * @sz: number of array elements to read.
1501 * @skip: Number of strings to skip over at beginning of list.
1502 *
1503 * Don't call this function directly. It is a utility helper for the
1504 * of_property_read_string*() family of functions.
1505 */
1506int of_property_read_string_helper(const struct device_node *np,
1507 const char *propname, const char **out_strs,
1508 size_t sz, int skip)
1509{
1510 const struct property *prop = of_find_property(np, propname, NULL);
1511 int l = 0, i = 0;
1512 const char *p, *end;
1513
1514 if (!prop)
1515 return -EINVAL;
1516 if (!prop->value)
1517 return -ENODATA;
1518 p = prop->value;
1519 end = p + prop->length;
1520
1521 for (i = 0; p < end && (!out_strs || i < skip + sz); i++, p += l) {
1522 l = strnlen(p, end - p) + 1;
1523 if (p + l > end)
1524 return -EILSEQ;
1525 if (out_strs && i >= skip)
1526 *out_strs++ = p;
1527 }
1528 i -= skip;
1529 return i <= 0 ? -ENODATA : i;
1530}
1531EXPORT_SYMBOL_GPL(of_property_read_string_helper);
1532
1533void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1534{
1535 int i;
1536 printk("%s %s", msg, of_node_full_name(args->np));
1537 for (i = 0; i < args->args_count; i++) {
1538 const char delim = i ? ',' : ':';
1539
1540 pr_cont("%c%08x", delim, args->args[i]);
1541 }
1542 pr_cont("\n");
1543}
1544
1545int of_phandle_iterator_init(struct of_phandle_iterator *it,
1546 const struct device_node *np,
1547 const char *list_name,
1548 const char *cells_name,
1549 int cell_count)
1550{
1551 const __be32 *list;
1552 int size;
1553
1554 memset(it, 0, sizeof(*it));
1555
1556 list = of_get_property(np, list_name, &size);
1557 if (!list)
1558 return -ENOENT;
1559
1560 it->cells_name = cells_name;
1561 it->cell_count = cell_count;
1562 it->parent = np;
1563 it->list_end = list + size / sizeof(*list);
1564 it->phandle_end = list;
1565 it->cur = list;
1566
1567 return 0;
1568}
1569
1570int of_phandle_iterator_next(struct of_phandle_iterator *it)
1571{
1572 uint32_t count = 0;
1573
1574 if (it->node) {
1575 of_node_put(it->node);
1576 it->node = NULL;
1577 }
1578
1579 if (!it->cur || it->phandle_end >= it->list_end)
1580 return -ENOENT;
1581
1582 it->cur = it->phandle_end;
1583
1584 /* If phandle is 0, then it is an empty entry with no arguments. */
1585 it->phandle = be32_to_cpup(it->cur++);
1586
1587 if (it->phandle) {
1588
1589 /*
1590 * Find the provider node and parse the #*-cells property to
1591 * determine the argument length.
1592 */
1593 it->node = of_find_node_by_phandle(it->phandle);
1594
1595 if (it->cells_name) {
1596 if (!it->node) {
1597 pr_err("%s: could not find phandle\n",
1598 it->parent->full_name);
1599 goto err;
1600 }
1601
1602 if (of_property_read_u32(it->node, it->cells_name,
1603 &count)) {
1604 pr_err("%s: could not get %s for %s\n",
1605 it->parent->full_name,
1606 it->cells_name,
1607 it->node->full_name);
1608 goto err;
1609 }
1610 } else {
1611 count = it->cell_count;
1612 }
1613
1614 /*
1615 * Make sure that the arguments actually fit in the remaining
1616 * property data length
1617 */
1618 if (it->cur + count > it->list_end) {
1619 pr_err("%s: arguments longer than property\n",
1620 it->parent->full_name);
1621 goto err;
1622 }
1623 }
1624
1625 it->phandle_end = it->cur + count;
1626 it->cur_count = count;
1627
1628 return 0;
1629
1630err:
1631 if (it->node) {
1632 of_node_put(it->node);
1633 it->node = NULL;
1634 }
1635
1636 return -EINVAL;
1637}
1638
1639int of_phandle_iterator_args(struct of_phandle_iterator *it,
1640 uint32_t *args,
1641 int size)
1642{
1643 int i, count;
1644
1645 count = it->cur_count;
1646
1647 if (WARN_ON(size < count))
1648 count = size;
1649
1650 for (i = 0; i < count; i++)
1651 args[i] = be32_to_cpup(it->cur++);
1652
1653 return count;
1654}
1655
1656static int __of_parse_phandle_with_args(const struct device_node *np,
1657 const char *list_name,
1658 const char *cells_name,
1659 int cell_count, int index,
1660 struct of_phandle_args *out_args)
1661{
1662 struct of_phandle_iterator it;
1663 int rc, cur_index = 0;
1664
1665 /* Loop over the phandles until all the requested entry is found */
1666 of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
1667 /*
1668 * All of the error cases bail out of the loop, so at
1669 * this point, the parsing is successful. If the requested
1670 * index matches, then fill the out_args structure and return,
1671 * or return -ENOENT for an empty entry.
1672 */
1673 rc = -ENOENT;
1674 if (cur_index == index) {
1675 if (!it.phandle)
1676 goto err;
1677
1678 if (out_args) {
1679 int c;
1680
1681 c = of_phandle_iterator_args(&it,
1682 out_args->args,
1683 MAX_PHANDLE_ARGS);
1684 out_args->np = it.node;
1685 out_args->args_count = c;
1686 } else {
1687 of_node_put(it.node);
1688 }
1689
1690 /* Found it! return success */
1691 return 0;
1692 }
1693
1694 cur_index++;
1695 }
1696
1697 /*
1698 * Unlock node before returning result; will be one of:
1699 * -ENOENT : index is for empty phandle
1700 * -EINVAL : parsing error on data
1701 */
1702
1703 err:
1704 of_node_put(it.node);
1705 return rc;
1706}
1707
1708/**
1709 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1710 * @np: Pointer to device node holding phandle property
1711 * @phandle_name: Name of property holding a phandle value
1712 * @index: For properties holding a table of phandles, this is the index into
1713 * the table
1714 *
1715 * Returns the device_node pointer with refcount incremented. Use
1716 * of_node_put() on it when done.
1717 */
1718struct device_node *of_parse_phandle(const struct device_node *np,
1719 const char *phandle_name, int index)
1720{
1721 struct of_phandle_args args;
1722
1723 if (index < 0)
1724 return NULL;
1725
1726 if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1727 index, &args))
1728 return NULL;
1729
1730 return args.np;
1731}
1732EXPORT_SYMBOL(of_parse_phandle);
1733
1734/**
1735 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1736 * @np: pointer to a device tree node containing a list
1737 * @list_name: property name that contains a list
1738 * @cells_name: property name that specifies phandles' arguments count
1739 * @index: index of a phandle to parse out
1740 * @out_args: optional pointer to output arguments structure (will be filled)
1741 *
1742 * This function is useful to parse lists of phandles and their arguments.
1743 * Returns 0 on success and fills out_args, on error returns appropriate
1744 * errno value.
1745 *
1746 * Caller is responsible to call of_node_put() on the returned out_args->np
1747 * pointer.
1748 *
1749 * Example:
1750 *
1751 * phandle1: node1 {
1752 * #list-cells = <2>;
1753 * }
1754 *
1755 * phandle2: node2 {
1756 * #list-cells = <1>;
1757 * }
1758 *
1759 * node3 {
1760 * list = <&phandle1 1 2 &phandle2 3>;
1761 * }
1762 *
1763 * To get a device_node of the `node2' node you may call this:
1764 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1765 */
1766int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1767 const char *cells_name, int index,
1768 struct of_phandle_args *out_args)
1769{
1770 if (index < 0)
1771 return -EINVAL;
1772 return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
1773 index, out_args);
1774}
1775EXPORT_SYMBOL(of_parse_phandle_with_args);
1776
1777/**
1778 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1779 * @np: pointer to a device tree node containing a list
1780 * @list_name: property name that contains a list
1781 * @cell_count: number of argument cells following the phandle
1782 * @index: index of a phandle to parse out
1783 * @out_args: optional pointer to output arguments structure (will be filled)
1784 *
1785 * This function is useful to parse lists of phandles and their arguments.
1786 * Returns 0 on success and fills out_args, on error returns appropriate
1787 * errno value.
1788 *
1789 * Caller is responsible to call of_node_put() on the returned out_args->np
1790 * pointer.
1791 *
1792 * Example:
1793 *
1794 * phandle1: node1 {
1795 * }
1796 *
1797 * phandle2: node2 {
1798 * }
1799 *
1800 * node3 {
1801 * list = <&phandle1 0 2 &phandle2 2 3>;
1802 * }
1803 *
1804 * To get a device_node of the `node2' node you may call this:
1805 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1806 */
1807int of_parse_phandle_with_fixed_args(const struct device_node *np,
1808 const char *list_name, int cell_count,
1809 int index, struct of_phandle_args *out_args)
1810{
1811 if (index < 0)
1812 return -EINVAL;
1813 return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1814 index, out_args);
1815}
1816EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1817
1818/**
1819 * of_count_phandle_with_args() - Find the number of phandles references in a property
1820 * @np: pointer to a device tree node containing a list
1821 * @list_name: property name that contains a list
1822 * @cells_name: property name that specifies phandles' arguments count
1823 *
1824 * Returns the number of phandle + argument tuples within a property. It
1825 * is a typical pattern to encode a list of phandle and variable
1826 * arguments into a single property. The number of arguments is encoded
1827 * by a property in the phandle-target node. For example, a gpios
1828 * property would contain a list of GPIO specifies consisting of a
1829 * phandle and 1 or more arguments. The number of arguments are
1830 * determined by the #gpio-cells property in the node pointed to by the
1831 * phandle.
1832 */
1833int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1834 const char *cells_name)
1835{
1836 struct of_phandle_iterator it;
1837 int rc, cur_index = 0;
1838
1839 rc = of_phandle_iterator_init(&it, np, list_name, cells_name, 0);
1840 if (rc)
1841 return rc;
1842
1843 while ((rc = of_phandle_iterator_next(&it)) == 0)
1844 cur_index += 1;
1845
1846 if (rc != -ENOENT)
1847 return rc;
1848
1849 return cur_index;
1850}
1851EXPORT_SYMBOL(of_count_phandle_with_args);
1852
1853/**
1854 * __of_add_property - Add a property to a node without lock operations
1855 */
1856int __of_add_property(struct device_node *np, struct property *prop)
1857{
1858 struct property **next;
1859
1860 prop->next = NULL;
1861 next = &np->properties;
1862 while (*next) {
1863 if (strcmp(prop->name, (*next)->name) == 0)
1864 /* duplicate ! don't insert it */
1865 return -EEXIST;
1866
1867 next = &(*next)->next;
1868 }
1869 *next = prop;
1870
1871 return 0;
1872}
1873
1874/**
1875 * of_add_property - Add a property to a node
1876 */
1877int of_add_property(struct device_node *np, struct property *prop)
1878{
1879 unsigned long flags;
1880 int rc;
1881
1882 mutex_lock(&of_mutex);
1883
1884 raw_spin_lock_irqsave(&devtree_lock, flags);
1885 rc = __of_add_property(np, prop);
1886 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1887
1888 if (!rc)
1889 __of_add_property_sysfs(np, prop);
1890
1891 mutex_unlock(&of_mutex);
1892
1893 if (!rc)
1894 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1895
1896 return rc;
1897}
1898
1899int __of_remove_property(struct device_node *np, struct property *prop)
1900{
1901 struct property **next;
1902
1903 for (next = &np->properties; *next; next = &(*next)->next) {
1904 if (*next == prop)
1905 break;
1906 }
1907 if (*next == NULL)
1908 return -ENODEV;
1909
1910 /* found the node */
1911 *next = prop->next;
1912 prop->next = np->deadprops;
1913 np->deadprops = prop;
1914
1915 return 0;
1916}
1917
1918void __of_sysfs_remove_bin_file(struct device_node *np, struct property *prop)
1919{
1920 sysfs_remove_bin_file(&np->kobj, &prop->attr);
1921 kfree(prop->attr.attr.name);
1922}
1923
1924void __of_remove_property_sysfs(struct device_node *np, struct property *prop)
1925{
1926 if (!IS_ENABLED(CONFIG_SYSFS))
1927 return;
1928
1929 /* at early boot, bail here and defer setup to of_init() */
1930 if (of_kset && of_node_is_attached(np))
1931 __of_sysfs_remove_bin_file(np, prop);
1932}
1933
1934/**
1935 * of_remove_property - Remove a property from a node.
1936 *
1937 * Note that we don't actually remove it, since we have given out
1938 * who-knows-how-many pointers to the data using get-property.
1939 * Instead we just move the property to the "dead properties"
1940 * list, so it won't be found any more.
1941 */
1942int of_remove_property(struct device_node *np, struct property *prop)
1943{
1944 unsigned long flags;
1945 int rc;
1946
1947 if (!prop)
1948 return -ENODEV;
1949
1950 mutex_lock(&of_mutex);
1951
1952 raw_spin_lock_irqsave(&devtree_lock, flags);
1953 rc = __of_remove_property(np, prop);
1954 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1955
1956 if (!rc)
1957 __of_remove_property_sysfs(np, prop);
1958
1959 mutex_unlock(&of_mutex);
1960
1961 if (!rc)
1962 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1963
1964 return rc;
1965}
1966
1967int __of_update_property(struct device_node *np, struct property *newprop,
1968 struct property **oldpropp)
1969{
1970 struct property **next, *oldprop;
1971
1972 for (next = &np->properties; *next; next = &(*next)->next) {
1973 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1974 break;
1975 }
1976 *oldpropp = oldprop = *next;
1977
1978 if (oldprop) {
1979 /* replace the node */
1980 newprop->next = oldprop->next;
1981 *next = newprop;
1982 oldprop->next = np->deadprops;
1983 np->deadprops = oldprop;
1984 } else {
1985 /* new node */
1986 newprop->next = NULL;
1987 *next = newprop;
1988 }
1989
1990 return 0;
1991}
1992
1993void __of_update_property_sysfs(struct device_node *np, struct property *newprop,
1994 struct property *oldprop)
1995{
1996 if (!IS_ENABLED(CONFIG_SYSFS))
1997 return;
1998
1999 /* At early boot, bail out and defer setup to of_init() */
2000 if (!of_kset)
2001 return;
2002
2003 if (oldprop)
2004 __of_sysfs_remove_bin_file(np, oldprop);
2005 __of_add_property_sysfs(np, newprop);
2006}
2007
2008/*
2009 * of_update_property - Update a property in a node, if the property does
2010 * not exist, add it.
2011 *
2012 * Note that we don't actually remove it, since we have given out
2013 * who-knows-how-many pointers to the data using get-property.
2014 * Instead we just move the property to the "dead properties" list,
2015 * and add the new property to the property list
2016 */
2017int of_update_property(struct device_node *np, struct property *newprop)
2018{
2019 struct property *oldprop;
2020 unsigned long flags;
2021 int rc;
2022
2023 if (!newprop->name)
2024 return -EINVAL;
2025
2026 mutex_lock(&of_mutex);
2027
2028 raw_spin_lock_irqsave(&devtree_lock, flags);
2029 rc = __of_update_property(np, newprop, &oldprop);
2030 raw_spin_unlock_irqrestore(&devtree_lock, flags);
2031
2032 if (!rc)
2033 __of_update_property_sysfs(np, newprop, oldprop);
2034
2035 mutex_unlock(&of_mutex);
2036
2037 if (!rc)
2038 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
2039
2040 return rc;
2041}
2042
2043static void of_alias_add(struct alias_prop *ap, struct device_node *np,
2044 int id, const char *stem, int stem_len)
2045{
2046 ap->np = np;
2047 ap->id = id;
2048 strncpy(ap->stem, stem, stem_len);
2049 ap->stem[stem_len] = 0;
2050 list_add_tail(&ap->link, &aliases_lookup);
2051 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
2052 ap->alias, ap->stem, ap->id, of_node_full_name(np));
2053}
2054
2055/**
2056 * of_alias_scan - Scan all properties of the 'aliases' node
2057 *
2058 * The function scans all the properties of the 'aliases' node and populates
2059 * the global lookup table with the properties. It returns the
2060 * number of alias properties found, or an error code in case of failure.
2061 *
2062 * @dt_alloc: An allocator that provides a virtual address to memory
2063 * for storing the resulting tree
2064 */
2065void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
2066{
2067 struct property *pp;
2068
2069 of_aliases = of_find_node_by_path("/aliases");
2070 of_chosen = of_find_node_by_path("/chosen");
2071 if (of_chosen == NULL)
2072 of_chosen = of_find_node_by_path("/chosen@0");
2073
2074 if (of_chosen) {
2075 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
2076 const char *name = of_get_property(of_chosen, "stdout-path", NULL);
2077 if (!name)
2078 name = of_get_property(of_chosen, "linux,stdout-path", NULL);
2079 if (IS_ENABLED(CONFIG_PPC) && !name)
2080 name = of_get_property(of_aliases, "stdout", NULL);
2081 if (name)
2082 of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
2083 }
2084
2085 if (!of_aliases)
2086 return;
2087
2088 for_each_property_of_node(of_aliases, pp) {
2089 const char *start = pp->name;
2090 const char *end = start + strlen(start);
2091 struct device_node *np;
2092 struct alias_prop *ap;
2093 int id, len;
2094
2095 /* Skip those we do not want to proceed */
2096 if (!strcmp(pp->name, "name") ||
2097 !strcmp(pp->name, "phandle") ||
2098 !strcmp(pp->name, "linux,phandle"))
2099 continue;
2100
2101 np = of_find_node_by_path(pp->value);
2102 if (!np)
2103 continue;
2104
2105 /* walk the alias backwards to extract the id and work out
2106 * the 'stem' string */
2107 while (isdigit(*(end-1)) && end > start)
2108 end--;
2109 len = end - start;
2110
2111 if (kstrtoint(end, 10, &id) < 0)
2112 continue;
2113
2114 /* Allocate an alias_prop with enough space for the stem */
2115 ap = dt_alloc(sizeof(*ap) + len + 1, 4);
2116 if (!ap)
2117 continue;
2118 memset(ap, 0, sizeof(*ap) + len + 1);
2119 ap->alias = start;
2120 of_alias_add(ap, np, id, start, len);
2121 }
2122}
2123
2124/**
2125 * of_alias_get_id - Get alias id for the given device_node
2126 * @np: Pointer to the given device_node
2127 * @stem: Alias stem of the given device_node
2128 *
2129 * The function travels the lookup table to get the alias id for the given
2130 * device_node and alias stem. It returns the alias id if found.
2131 */
2132int of_alias_get_id(struct device_node *np, const char *stem)
2133{
2134 struct alias_prop *app;
2135 int id = -ENODEV;
2136
2137 mutex_lock(&of_mutex);
2138 list_for_each_entry(app, &aliases_lookup, link) {
2139 if (strcmp(app->stem, stem) != 0)
2140 continue;
2141
2142 if (np == app->np) {
2143 id = app->id;
2144 break;
2145 }
2146 }
2147 mutex_unlock(&of_mutex);
2148
2149 return id;
2150}
2151EXPORT_SYMBOL_GPL(of_alias_get_id);
2152
2153/**
2154 * of_alias_get_highest_id - Get highest alias id for the given stem
2155 * @stem: Alias stem to be examined
2156 *
2157 * The function travels the lookup table to get the highest alias id for the
2158 * given alias stem. It returns the alias id if found.
2159 */
2160int of_alias_get_highest_id(const char *stem)
2161{
2162 struct alias_prop *app;
2163 int id = -ENODEV;
2164
2165 mutex_lock(&of_mutex);
2166 list_for_each_entry(app, &aliases_lookup, link) {
2167 if (strcmp(app->stem, stem) != 0)
2168 continue;
2169
2170 if (app->id > id)
2171 id = app->id;
2172 }
2173 mutex_unlock(&of_mutex);
2174
2175 return id;
2176}
2177EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
2178
2179const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
2180 u32 *pu)
2181{
2182 const void *curv = cur;
2183
2184 if (!prop)
2185 return NULL;
2186
2187 if (!cur) {
2188 curv = prop->value;
2189 goto out_val;
2190 }
2191
2192 curv += sizeof(*cur);
2193 if (curv >= prop->value + prop->length)
2194 return NULL;
2195
2196out_val:
2197 *pu = be32_to_cpup(curv);
2198 return curv;
2199}
2200EXPORT_SYMBOL_GPL(of_prop_next_u32);
2201
2202const char *of_prop_next_string(struct property *prop, const char *cur)
2203{
2204 const void *curv = cur;
2205
2206 if (!prop)
2207 return NULL;
2208
2209 if (!cur)
2210 return prop->value;
2211
2212 curv += strlen(cur) + 1;
2213 if (curv >= prop->value + prop->length)
2214 return NULL;
2215
2216 return curv;
2217}
2218EXPORT_SYMBOL_GPL(of_prop_next_string);
2219
2220/**
2221 * of_console_check() - Test and setup console for DT setup
2222 * @dn - Pointer to device node
2223 * @name - Name to use for preferred console without index. ex. "ttyS"
2224 * @index - Index to use for preferred console.
2225 *
2226 * Check if the given device node matches the stdout-path property in the
2227 * /chosen node. If it does then register it as the preferred console and return
2228 * TRUE. Otherwise return FALSE.
2229 */
2230bool of_console_check(struct device_node *dn, char *name, int index)
2231{
2232 if (!dn || dn != of_stdout || console_set_on_cmdline)
2233 return false;
2234 return !add_preferred_console(name, index,
2235 kstrdup(of_stdout_options, GFP_KERNEL));
2236}
2237EXPORT_SYMBOL_GPL(of_console_check);
2238
2239/**
2240 * of_find_next_cache_node - Find a node's subsidiary cache
2241 * @np: node of type "cpu" or "cache"
2242 *
2243 * Returns a node pointer with refcount incremented, use
2244 * of_node_put() on it when done. Caller should hold a reference
2245 * to np.
2246 */
2247struct device_node *of_find_next_cache_node(const struct device_node *np)
2248{
2249 struct device_node *child;
2250 const phandle *handle;
2251
2252 handle = of_get_property(np, "l2-cache", NULL);
2253 if (!handle)
2254 handle = of_get_property(np, "next-level-cache", NULL);
2255
2256 if (handle)
2257 return of_find_node_by_phandle(be32_to_cpup(handle));
2258
2259 /* OF on pmac has nodes instead of properties named "l2-cache"
2260 * beneath CPU nodes.
2261 */
2262 if (!strcmp(np->type, "cpu"))
2263 for_each_child_of_node(np, child)
2264 if (!strcmp(child->type, "cache"))
2265 return child;
2266
2267 return NULL;
2268}
2269
2270/**
2271 * of_graph_parse_endpoint() - parse common endpoint node properties
2272 * @node: pointer to endpoint device_node
2273 * @endpoint: pointer to the OF endpoint data structure
2274 *
2275 * The caller should hold a reference to @node.
2276 */
2277int of_graph_parse_endpoint(const struct device_node *node,
2278 struct of_endpoint *endpoint)
2279{
2280 struct device_node *port_node = of_get_parent(node);
2281
2282 WARN_ONCE(!port_node, "%s(): endpoint %s has no parent node\n",
2283 __func__, node->full_name);
2284
2285 memset(endpoint, 0, sizeof(*endpoint));
2286
2287 endpoint->local_node = node;
2288 /*
2289 * It doesn't matter whether the two calls below succeed.
2290 * If they don't then the default value 0 is used.
2291 */
2292 of_property_read_u32(port_node, "reg", &endpoint->port);
2293 of_property_read_u32(node, "reg", &endpoint->id);
2294
2295 of_node_put(port_node);
2296
2297 return 0;
2298}
2299EXPORT_SYMBOL(of_graph_parse_endpoint);
2300
2301/**
2302 * of_graph_get_port_by_id() - get the port matching a given id
2303 * @parent: pointer to the parent device node
2304 * @id: id of the port
2305 *
2306 * Return: A 'port' node pointer with refcount incremented. The caller
2307 * has to use of_node_put() on it when done.
2308 */
2309struct device_node *of_graph_get_port_by_id(struct device_node *parent, u32 id)
2310{
2311 struct device_node *node, *port;
2312
2313 node = of_get_child_by_name(parent, "ports");
2314 if (node)
2315 parent = node;
2316
2317 for_each_child_of_node(parent, port) {
2318 u32 port_id = 0;
2319
2320 if (of_node_cmp(port->name, "port") != 0)
2321 continue;
2322 of_property_read_u32(port, "reg", &port_id);
2323 if (id == port_id)
2324 break;
2325 }
2326
2327 of_node_put(node);
2328
2329 return port;
2330}
2331EXPORT_SYMBOL(of_graph_get_port_by_id);
2332
2333/**
2334 * of_graph_get_next_endpoint() - get next endpoint node
2335 * @parent: pointer to the parent device node
2336 * @prev: previous endpoint node, or NULL to get first
2337 *
2338 * Return: An 'endpoint' node pointer with refcount incremented. Refcount
2339 * of the passed @prev node is decremented.
2340 */
2341struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
2342 struct device_node *prev)
2343{
2344 struct device_node *endpoint;
2345 struct device_node *port;
2346
2347 if (!parent)
2348 return NULL;
2349
2350 /*
2351 * Start by locating the port node. If no previous endpoint is specified
2352 * search for the first port node, otherwise get the previous endpoint
2353 * parent port node.
2354 */
2355 if (!prev) {
2356 struct device_node *node;
2357
2358 node = of_get_child_by_name(parent, "ports");
2359 if (node)
2360 parent = node;
2361
2362 port = of_get_child_by_name(parent, "port");
2363 of_node_put(node);
2364
2365 if (!port) {
2366 pr_err("graph: no port node found in %s\n",
2367 parent->full_name);
2368 return NULL;
2369 }
2370 } else {
2371 port = of_get_parent(prev);
2372 if (WARN_ONCE(!port, "%s(): endpoint %s has no parent node\n",
2373 __func__, prev->full_name))
2374 return NULL;
2375 }
2376
2377 while (1) {
2378 /*
2379 * Now that we have a port node, get the next endpoint by
2380 * getting the next child. If the previous endpoint is NULL this
2381 * will return the first child.
2382 */
2383 endpoint = of_get_next_child(port, prev);
2384 if (endpoint) {
2385 of_node_put(port);
2386 return endpoint;
2387 }
2388
2389 /* No more endpoints under this port, try the next one. */
2390 prev = NULL;
2391
2392 do {
2393 port = of_get_next_child(parent, port);
2394 if (!port)
2395 return NULL;
2396 } while (of_node_cmp(port->name, "port"));
2397 }
2398}
2399EXPORT_SYMBOL(of_graph_get_next_endpoint);
2400
2401/**
2402 * of_graph_get_endpoint_by_regs() - get endpoint node of specific identifiers
2403 * @parent: pointer to the parent device node
2404 * @port_reg: identifier (value of reg property) of the parent port node
2405 * @reg: identifier (value of reg property) of the endpoint node
2406 *
2407 * Return: An 'endpoint' node pointer which is identified by reg and at the same
2408 * is the child of a port node identified by port_reg. reg and port_reg are
2409 * ignored when they are -1.
2410 */
2411struct device_node *of_graph_get_endpoint_by_regs(
2412 const struct device_node *parent, int port_reg, int reg)
2413{
2414 struct of_endpoint endpoint;
2415 struct device_node *node = NULL;
2416
2417 for_each_endpoint_of_node(parent, node) {
2418 of_graph_parse_endpoint(node, &endpoint);
2419 if (((port_reg == -1) || (endpoint.port == port_reg)) &&
2420 ((reg == -1) || (endpoint.id == reg)))
2421 return node;
2422 }
2423
2424 return NULL;
2425}
2426EXPORT_SYMBOL(of_graph_get_endpoint_by_regs);
2427
2428/**
2429 * of_graph_get_remote_port_parent() - get remote port's parent node
2430 * @node: pointer to a local endpoint device_node
2431 *
2432 * Return: Remote device node associated with remote endpoint node linked
2433 * to @node. Use of_node_put() on it when done.
2434 */
2435struct device_node *of_graph_get_remote_port_parent(
2436 const struct device_node *node)
2437{
2438 struct device_node *np;
2439 unsigned int depth;
2440
2441 /* Get remote endpoint node. */
2442 np = of_parse_phandle(node, "remote-endpoint", 0);
2443
2444 /* Walk 3 levels up only if there is 'ports' node. */
2445 for (depth = 3; depth && np; depth--) {
2446 np = of_get_next_parent(np);
2447 if (depth == 2 && of_node_cmp(np->name, "ports"))
2448 break;
2449 }
2450 return np;
2451}
2452EXPORT_SYMBOL(of_graph_get_remote_port_parent);
2453
2454/**
2455 * of_graph_get_remote_port() - get remote port node
2456 * @node: pointer to a local endpoint device_node
2457 *
2458 * Return: Remote port node associated with remote endpoint node linked
2459 * to @node. Use of_node_put() on it when done.
2460 */
2461struct device_node *of_graph_get_remote_port(const struct device_node *node)
2462{
2463 struct device_node *np;
2464
2465 /* Get remote endpoint node. */
2466 np = of_parse_phandle(node, "remote-endpoint", 0);
2467 if (!np)
2468 return NULL;
2469 return of_get_next_parent(np);
2470}
2471EXPORT_SYMBOL(of_graph_get_remote_port);