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