1 /*
2 * Procedures for creating, accessing and interpreting the device tree.
3 *
4 * Paul Mackerras August 1996.
5 * Copyright (C) 1996-2005 Paul Mackerras.
6 *
7 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
8 * {engebret|bergner}@us.ibm.com
9 *
10 * Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
11 *
12 * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
13 * Grant Likely.
14 *
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
19 */
20 #include <linux/ctype.h>
21 #include <linux/cpu.h>
22 #include <linux/module.h>
23 #include <linux/of.h>
24 #include <linux/spinlock.h>
25 #include <linux/slab.h>
26 #include <linux/proc_fs.h>
27
28 #include "of_private.h"
29
30 LIST_HEAD(aliases_lookup);
31
32 struct device_node *of_allnodes;
33 EXPORT_SYMBOL(of_allnodes);
34 struct device_node *of_chosen;
35 struct device_node *of_aliases;
36
37 DEFINE_MUTEX(of_aliases_mutex);
38
39 /* use when traversing tree through the allnext, child, sibling,
40 * or parent members of struct device_node.
41 */
42 DEFINE_RAW_SPINLOCK(devtree_lock);
43
of_n_addr_cells(struct device_node * np)44 int of_n_addr_cells(struct device_node *np)
45 {
46 const __be32 *ip;
47
48 do {
49 if (np->parent)
50 np = np->parent;
51 ip = of_get_property(np, "#address-cells", NULL);
52 if (ip)
53 return be32_to_cpup(ip);
54 } while (np->parent);
55 /* No #address-cells property for the root node */
56 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
57 }
58 EXPORT_SYMBOL(of_n_addr_cells);
59
of_n_size_cells(struct device_node * np)60 int of_n_size_cells(struct device_node *np)
61 {
62 const __be32 *ip;
63
64 do {
65 if (np->parent)
66 np = np->parent;
67 ip = of_get_property(np, "#size-cells", NULL);
68 if (ip)
69 return be32_to_cpup(ip);
70 } while (np->parent);
71 /* No #size-cells property for the root node */
72 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
73 }
74 EXPORT_SYMBOL(of_n_size_cells);
75
76 #if defined(CONFIG_OF_DYNAMIC)
77 /**
78 * of_node_get - Increment refcount of a node
79 * @node: Node to inc refcount, NULL is supported to
80 * simplify writing of callers
81 *
82 * Returns node.
83 */
of_node_get(struct device_node * node)84 struct device_node *of_node_get(struct device_node *node)
85 {
86 if (node)
87 kref_get(&node->kref);
88 return node;
89 }
90 EXPORT_SYMBOL(of_node_get);
91
kref_to_device_node(struct kref * kref)92 static inline struct device_node *kref_to_device_node(struct kref *kref)
93 {
94 return container_of(kref, struct device_node, kref);
95 }
96
97 /**
98 * of_node_release - release a dynamically allocated node
99 * @kref: kref element of the node to be released
100 *
101 * In of_node_put() this function is passed to kref_put()
102 * as the destructor.
103 */
of_node_release(struct kref * kref)104 static void of_node_release(struct kref *kref)
105 {
106 struct device_node *node = kref_to_device_node(kref);
107 struct property *prop = node->properties;
108
109 /* We should never be releasing nodes that haven't been detached. */
110 if (!of_node_check_flag(node, OF_DETACHED)) {
111 pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name);
112 dump_stack();
113 kref_init(&node->kref);
114 return;
115 }
116
117 if (!of_node_check_flag(node, OF_DYNAMIC))
118 return;
119
120 while (prop) {
121 struct property *next = prop->next;
122 kfree(prop->name);
123 kfree(prop->value);
124 kfree(prop);
125 prop = next;
126
127 if (!prop) {
128 prop = node->deadprops;
129 node->deadprops = NULL;
130 }
131 }
132 kfree(node->full_name);
133 kfree(node->data);
134 kfree(node);
135 }
136
137 /**
138 * of_node_put - Decrement refcount of a node
139 * @node: Node to dec refcount, NULL is supported to
140 * simplify writing of callers
141 *
142 */
of_node_put(struct device_node * node)143 void of_node_put(struct device_node *node)
144 {
145 if (node)
146 kref_put(&node->kref, of_node_release);
147 }
148 EXPORT_SYMBOL(of_node_put);
149 #endif /* CONFIG_OF_DYNAMIC */
150
__of_find_property(const struct device_node * np,const char * name,int * lenp)151 static struct property *__of_find_property(const struct device_node *np,
152 const char *name, int *lenp)
153 {
154 struct property *pp;
155
156 if (!np)
157 return NULL;
158
159 for (pp = np->properties; pp; pp = pp->next) {
160 if (of_prop_cmp(pp->name, name) == 0) {
161 if (lenp)
162 *lenp = pp->length;
163 break;
164 }
165 }
166
167 return pp;
168 }
169
of_find_property(const struct device_node * np,const char * name,int * lenp)170 struct property *of_find_property(const struct device_node *np,
171 const char *name,
172 int *lenp)
173 {
174 struct property *pp;
175 unsigned long flags;
176
177 raw_spin_lock_irqsave(&devtree_lock, flags);
178 pp = __of_find_property(np, name, lenp);
179 raw_spin_unlock_irqrestore(&devtree_lock, flags);
180
181 return pp;
182 }
183 EXPORT_SYMBOL(of_find_property);
184
185 /**
186 * of_find_all_nodes - Get next node in global list
187 * @prev: Previous node or NULL to start iteration
188 * of_node_put() will be called on it
189 *
190 * Returns a node pointer with refcount incremented, use
191 * of_node_put() on it when done.
192 */
of_find_all_nodes(struct device_node * prev)193 struct device_node *of_find_all_nodes(struct device_node *prev)
194 {
195 struct device_node *np;
196 unsigned long flags;
197
198 raw_spin_lock_irqsave(&devtree_lock, flags);
199 np = prev ? prev->allnext : of_allnodes;
200 for (; np != NULL; np = np->allnext)
201 if (of_node_get(np))
202 break;
203 of_node_put(prev);
204 raw_spin_unlock_irqrestore(&devtree_lock, flags);
205 return np;
206 }
207 EXPORT_SYMBOL(of_find_all_nodes);
208
209 /*
210 * Find a property with a given name for a given node
211 * and return the value.
212 */
__of_get_property(const struct device_node * np,const char * name,int * lenp)213 static const void *__of_get_property(const struct device_node *np,
214 const char *name, int *lenp)
215 {
216 struct property *pp = __of_find_property(np, name, lenp);
217
218 return pp ? pp->value : NULL;
219 }
220
221 /*
222 * Find a property with a given name for a given node
223 * and return the value.
224 */
of_get_property(const struct device_node * np,const char * name,int * lenp)225 const void *of_get_property(const struct device_node *np, const char *name,
226 int *lenp)
227 {
228 struct property *pp = of_find_property(np, name, lenp);
229
230 return pp ? pp->value : NULL;
231 }
232 EXPORT_SYMBOL(of_get_property);
233
234 /*
235 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
236 *
237 * @cpu: logical cpu index of a core/thread
238 * @phys_id: physical identifier of a core/thread
239 *
240 * CPU logical to physical index mapping is architecture specific.
241 * However this __weak function provides a default match of physical
242 * id to logical cpu index. phys_id provided here is usually values read
243 * from the device tree which must match the hardware internal registers.
244 *
245 * Returns true if the physical identifier and the logical cpu index
246 * correspond to the same core/thread, false otherwise.
247 */
arch_match_cpu_phys_id(int cpu,u64 phys_id)248 bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
249 {
250 return (u32)phys_id == cpu;
251 }
252
253 /**
254 * Checks if the given "prop_name" property holds the physical id of the
255 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
256 * NULL, local thread number within the core is returned in it.
257 */
__of_find_n_match_cpu_property(struct device_node * cpun,const char * prop_name,int cpu,unsigned int * thread)258 static bool __of_find_n_match_cpu_property(struct device_node *cpun,
259 const char *prop_name, int cpu, unsigned int *thread)
260 {
261 const __be32 *cell;
262 int ac, prop_len, tid;
263 u64 hwid;
264
265 ac = of_n_addr_cells(cpun);
266 cell = of_get_property(cpun, prop_name, &prop_len);
267 if (!cell)
268 return false;
269 prop_len /= sizeof(*cell);
270 for (tid = 0; tid < prop_len; tid++) {
271 hwid = of_read_number(cell, ac);
272 if (arch_match_cpu_phys_id(cpu, hwid)) {
273 if (thread)
274 *thread = tid;
275 return true;
276 }
277 cell += ac;
278 }
279 return false;
280 }
281
282 /**
283 * of_get_cpu_node - Get device node associated with the given logical CPU
284 *
285 * @cpu: CPU number(logical index) for which device node is required
286 * @thread: if not NULL, local thread number within the physical core is
287 * returned
288 *
289 * The main purpose of this function is to retrieve the device node for the
290 * given logical CPU index. It should be used to initialize the of_node in
291 * cpu device. Once of_node in cpu device is populated, all the further
292 * references can use that instead.
293 *
294 * CPU logical to physical index mapping is architecture specific and is built
295 * before booting secondary cores. This function uses arch_match_cpu_phys_id
296 * which can be overridden by architecture specific implementation.
297 *
298 * Returns a node pointer for the logical cpu if found, else NULL.
299 */
of_get_cpu_node(int cpu,unsigned int * thread)300 struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
301 {
302 struct device_node *cpun, *cpus;
303
304 cpus = of_find_node_by_path("/cpus");
305 if (!cpus) {
306 pr_warn("Missing cpus node, bailing out\n");
307 return NULL;
308 }
309
310 for_each_child_of_node(cpus, cpun) {
311 if (of_node_cmp(cpun->type, "cpu"))
312 continue;
313 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
314 * for thread ids on PowerPC. If it doesn't exist fallback to
315 * standard "reg" property.
316 */
317 if (IS_ENABLED(CONFIG_PPC) &&
318 __of_find_n_match_cpu_property(cpun,
319 "ibm,ppc-interrupt-server#s", cpu, thread))
320 return cpun;
321 if (__of_find_n_match_cpu_property(cpun, "reg", cpu, thread))
322 return cpun;
323 }
324 return NULL;
325 }
326 EXPORT_SYMBOL(of_get_cpu_node);
327
328 /** Checks if the given "compat" string matches one of the strings in
329 * the device's "compatible" property
330 */
__of_device_is_compatible(const struct device_node * device,const char * compat)331 static int __of_device_is_compatible(const struct device_node *device,
332 const char *compat)
333 {
334 const char* cp;
335 int cplen, l;
336
337 cp = __of_get_property(device, "compatible", &cplen);
338 if (cp == NULL)
339 return 0;
340 while (cplen > 0) {
341 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
342 return 1;
343 l = strlen(cp) + 1;
344 cp += l;
345 cplen -= l;
346 }
347
348 return 0;
349 }
350
351 /** Checks if the given "compat" string matches one of the strings in
352 * the device's "compatible" property
353 */
of_device_is_compatible(const struct device_node * device,const char * compat)354 int of_device_is_compatible(const struct device_node *device,
355 const char *compat)
356 {
357 unsigned long flags;
358 int res;
359
360 raw_spin_lock_irqsave(&devtree_lock, flags);
361 res = __of_device_is_compatible(device, compat);
362 raw_spin_unlock_irqrestore(&devtree_lock, flags);
363 return res;
364 }
365 EXPORT_SYMBOL(of_device_is_compatible);
366
367 /**
368 * of_machine_is_compatible - Test root of device tree for a given compatible value
369 * @compat: compatible string to look for in root node's compatible property.
370 *
371 * Returns true if the root node has the given value in its
372 * compatible property.
373 */
of_machine_is_compatible(const char * compat)374 int of_machine_is_compatible(const char *compat)
375 {
376 struct device_node *root;
377 int rc = 0;
378
379 root = of_find_node_by_path("/");
380 if (root) {
381 rc = of_device_is_compatible(root, compat);
382 of_node_put(root);
383 }
384 return rc;
385 }
386 EXPORT_SYMBOL(of_machine_is_compatible);
387
388 /**
389 * __of_device_is_available - check if a device is available for use
390 *
391 * @device: Node to check for availability, with locks already held
392 *
393 * Returns 1 if the status property is absent or set to "okay" or "ok",
394 * 0 otherwise
395 */
__of_device_is_available(const struct device_node * device)396 static int __of_device_is_available(const struct device_node *device)
397 {
398 const char *status;
399 int statlen;
400
401 status = __of_get_property(device, "status", &statlen);
402 if (status == NULL)
403 return 1;
404
405 if (statlen > 0) {
406 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
407 return 1;
408 }
409
410 return 0;
411 }
412
413 /**
414 * of_device_is_available - check if a device is available for use
415 *
416 * @device: Node to check for availability
417 *
418 * Returns 1 if the status property is absent or set to "okay" or "ok",
419 * 0 otherwise
420 */
of_device_is_available(const struct device_node * device)421 int of_device_is_available(const struct device_node *device)
422 {
423 unsigned long flags;
424 int res;
425
426 raw_spin_lock_irqsave(&devtree_lock, flags);
427 res = __of_device_is_available(device);
428 raw_spin_unlock_irqrestore(&devtree_lock, flags);
429 return res;
430
431 }
432 EXPORT_SYMBOL(of_device_is_available);
433
434 /**
435 * of_get_parent - Get a node's parent if any
436 * @node: Node to get parent
437 *
438 * Returns a node pointer with refcount incremented, use
439 * of_node_put() on it when done.
440 */
of_get_parent(const struct device_node * node)441 struct device_node *of_get_parent(const struct device_node *node)
442 {
443 struct device_node *np;
444 unsigned long flags;
445
446 if (!node)
447 return NULL;
448
449 raw_spin_lock_irqsave(&devtree_lock, flags);
450 np = of_node_get(node->parent);
451 raw_spin_unlock_irqrestore(&devtree_lock, flags);
452 return np;
453 }
454 EXPORT_SYMBOL(of_get_parent);
455
456 /**
457 * of_get_next_parent - Iterate to a node's parent
458 * @node: Node to get parent of
459 *
460 * This is like of_get_parent() except that it drops the
461 * refcount on the passed node, making it suitable for iterating
462 * through a node's parents.
463 *
464 * Returns a node pointer with refcount incremented, use
465 * of_node_put() on it when done.
466 */
of_get_next_parent(struct device_node * node)467 struct device_node *of_get_next_parent(struct device_node *node)
468 {
469 struct device_node *parent;
470 unsigned long flags;
471
472 if (!node)
473 return NULL;
474
475 raw_spin_lock_irqsave(&devtree_lock, flags);
476 parent = of_node_get(node->parent);
477 of_node_put(node);
478 raw_spin_unlock_irqrestore(&devtree_lock, flags);
479 return parent;
480 }
481 EXPORT_SYMBOL(of_get_next_parent);
482
483 /**
484 * of_get_next_child - Iterate a node childs
485 * @node: parent node
486 * @prev: previous child of the parent node, or NULL to get first
487 *
488 * Returns a node pointer with refcount incremented, use
489 * of_node_put() on it when done.
490 */
of_get_next_child(const struct device_node * node,struct device_node * prev)491 struct device_node *of_get_next_child(const struct device_node *node,
492 struct device_node *prev)
493 {
494 struct device_node *next;
495 unsigned long flags;
496
497 raw_spin_lock_irqsave(&devtree_lock, flags);
498 next = prev ? prev->sibling : node->child;
499 for (; next; next = next->sibling)
500 if (of_node_get(next))
501 break;
502 of_node_put(prev);
503 raw_spin_unlock_irqrestore(&devtree_lock, flags);
504 return next;
505 }
506 EXPORT_SYMBOL(of_get_next_child);
507
508 /**
509 * of_get_next_available_child - Find the next available child node
510 * @node: parent node
511 * @prev: previous child of the parent node, or NULL to get first
512 *
513 * This function is like of_get_next_child(), except that it
514 * automatically skips any disabled nodes (i.e. status = "disabled").
515 */
of_get_next_available_child(const struct device_node * node,struct device_node * prev)516 struct device_node *of_get_next_available_child(const struct device_node *node,
517 struct device_node *prev)
518 {
519 struct device_node *next;
520 unsigned long flags;
521
522 raw_spin_lock_irqsave(&devtree_lock, flags);
523 next = prev ? prev->sibling : node->child;
524 for (; next; next = next->sibling) {
525 if (!__of_device_is_available(next))
526 continue;
527 if (of_node_get(next))
528 break;
529 }
530 of_node_put(prev);
531 raw_spin_unlock_irqrestore(&devtree_lock, flags);
532 return next;
533 }
534 EXPORT_SYMBOL(of_get_next_available_child);
535
536 /**
537 * of_get_child_by_name - Find the child node by name for a given parent
538 * @node: parent node
539 * @name: child name to look for.
540 *
541 * This function looks for child node for given matching name
542 *
543 * Returns a node pointer if found, with refcount incremented, use
544 * of_node_put() on it when done.
545 * Returns NULL if node is not found.
546 */
of_get_child_by_name(const struct device_node * node,const char * name)547 struct device_node *of_get_child_by_name(const struct device_node *node,
548 const char *name)
549 {
550 struct device_node *child;
551
552 for_each_child_of_node(node, child)
553 if (child->name && (of_node_cmp(child->name, name) == 0))
554 break;
555 return child;
556 }
557 EXPORT_SYMBOL(of_get_child_by_name);
558
559 /**
560 * of_find_node_by_path - Find a node matching a full OF path
561 * @path: The full path to match
562 *
563 * Returns a node pointer with refcount incremented, use
564 * of_node_put() on it when done.
565 */
of_find_node_by_path(const char * path)566 struct device_node *of_find_node_by_path(const char *path)
567 {
568 struct device_node *np = of_allnodes;
569 unsigned long flags;
570
571 raw_spin_lock_irqsave(&devtree_lock, flags);
572 for (; np; np = np->allnext) {
573 if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
574 && of_node_get(np))
575 break;
576 }
577 raw_spin_unlock_irqrestore(&devtree_lock, flags);
578 return np;
579 }
580 EXPORT_SYMBOL(of_find_node_by_path);
581
582 /**
583 * of_find_node_by_name - Find a node by its "name" property
584 * @from: The node to start searching from or NULL, the node
585 * you pass will not be searched, only the next one
586 * will; typically, you pass what the previous call
587 * returned. of_node_put() will be called on it
588 * @name: The name string to match against
589 *
590 * Returns a node pointer with refcount incremented, use
591 * of_node_put() on it when done.
592 */
of_find_node_by_name(struct device_node * from,const char * name)593 struct device_node *of_find_node_by_name(struct device_node *from,
594 const char *name)
595 {
596 struct device_node *np;
597 unsigned long flags;
598
599 raw_spin_lock_irqsave(&devtree_lock, flags);
600 np = from ? from->allnext : of_allnodes;
601 for (; np; np = np->allnext)
602 if (np->name && (of_node_cmp(np->name, name) == 0)
603 && of_node_get(np))
604 break;
605 of_node_put(from);
606 raw_spin_unlock_irqrestore(&devtree_lock, flags);
607 return np;
608 }
609 EXPORT_SYMBOL(of_find_node_by_name);
610
611 /**
612 * of_find_node_by_type - Find a node by its "device_type" property
613 * @from: The node to start searching from, or NULL to start searching
614 * the entire device tree. The node you pass will not be
615 * searched, only the next one will; typically, you pass
616 * what the previous call returned. of_node_put() will be
617 * called on from for you.
618 * @type: The type string to match against
619 *
620 * Returns a node pointer with refcount incremented, use
621 * of_node_put() on it when done.
622 */
of_find_node_by_type(struct device_node * from,const char * type)623 struct device_node *of_find_node_by_type(struct device_node *from,
624 const char *type)
625 {
626 struct device_node *np;
627 unsigned long flags;
628
629 raw_spin_lock_irqsave(&devtree_lock, flags);
630 np = from ? from->allnext : of_allnodes;
631 for (; np; np = np->allnext)
632 if (np->type && (of_node_cmp(np->type, type) == 0)
633 && of_node_get(np))
634 break;
635 of_node_put(from);
636 raw_spin_unlock_irqrestore(&devtree_lock, flags);
637 return np;
638 }
639 EXPORT_SYMBOL(of_find_node_by_type);
640
641 /**
642 * of_find_compatible_node - Find a node based on type and one of the
643 * tokens in its "compatible" property
644 * @from: The node to start searching from or NULL, the node
645 * you pass will not be searched, only the next one
646 * will; typically, you pass what the previous call
647 * returned. of_node_put() will be called on it
648 * @type: The type string to match "device_type" or NULL to ignore
649 * @compatible: The string to match to one of the tokens in the device
650 * "compatible" list.
651 *
652 * Returns a node pointer with refcount incremented, use
653 * of_node_put() on it when done.
654 */
of_find_compatible_node(struct device_node * from,const char * type,const char * compatible)655 struct device_node *of_find_compatible_node(struct device_node *from,
656 const char *type, const char *compatible)
657 {
658 struct device_node *np;
659 unsigned long flags;
660
661 raw_spin_lock_irqsave(&devtree_lock, flags);
662 np = from ? from->allnext : of_allnodes;
663 for (; np; np = np->allnext) {
664 if (type
665 && !(np->type && (of_node_cmp(np->type, type) == 0)))
666 continue;
667 if (__of_device_is_compatible(np, compatible) &&
668 of_node_get(np))
669 break;
670 }
671 of_node_put(from);
672 raw_spin_unlock_irqrestore(&devtree_lock, flags);
673 return np;
674 }
675 EXPORT_SYMBOL(of_find_compatible_node);
676
677 /**
678 * of_find_node_with_property - Find a node which has a property with
679 * the given name.
680 * @from: The node to start searching from or NULL, the node
681 * you pass will not be searched, only the next one
682 * will; typically, you pass what the previous call
683 * returned. of_node_put() will be called on it
684 * @prop_name: The name of the property to look for.
685 *
686 * Returns a node pointer with refcount incremented, use
687 * of_node_put() on it when done.
688 */
of_find_node_with_property(struct device_node * from,const char * prop_name)689 struct device_node *of_find_node_with_property(struct device_node *from,
690 const char *prop_name)
691 {
692 struct device_node *np;
693 struct property *pp;
694 unsigned long flags;
695
696 raw_spin_lock_irqsave(&devtree_lock, flags);
697 np = from ? from->allnext : of_allnodes;
698 for (; np; np = np->allnext) {
699 for (pp = np->properties; pp; pp = pp->next) {
700 if (of_prop_cmp(pp->name, prop_name) == 0) {
701 of_node_get(np);
702 goto out;
703 }
704 }
705 }
706 out:
707 of_node_put(from);
708 raw_spin_unlock_irqrestore(&devtree_lock, flags);
709 return np;
710 }
711 EXPORT_SYMBOL(of_find_node_with_property);
712
713 static
__of_match_node(const struct of_device_id * matches,const struct device_node * node)714 const struct of_device_id *__of_match_node(const struct of_device_id *matches,
715 const struct device_node *node)
716 {
717 if (!matches)
718 return NULL;
719
720 while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
721 int match = 1;
722 if (matches->name[0])
723 match &= node->name
724 && !strcmp(matches->name, node->name);
725 if (matches->type[0])
726 match &= node->type
727 && !strcmp(matches->type, node->type);
728 if (matches->compatible[0])
729 match &= __of_device_is_compatible(node,
730 matches->compatible);
731 if (match)
732 return matches;
733 matches++;
734 }
735 return NULL;
736 }
737
738 /**
739 * of_match_node - Tell if an device_node has a matching of_match structure
740 * @matches: array of of device match structures to search in
741 * @node: the of device structure to match against
742 *
743 * Low level utility function used by device matching.
744 */
of_match_node(const struct of_device_id * matches,const struct device_node * node)745 const struct of_device_id *of_match_node(const struct of_device_id *matches,
746 const struct device_node *node)
747 {
748 const struct of_device_id *match;
749 unsigned long flags;
750
751 raw_spin_lock_irqsave(&devtree_lock, flags);
752 match = __of_match_node(matches, node);
753 raw_spin_unlock_irqrestore(&devtree_lock, flags);
754 return match;
755 }
756 EXPORT_SYMBOL(of_match_node);
757
758 /**
759 * of_find_matching_node_and_match - Find a node based on an of_device_id
760 * match table.
761 * @from: The node to start searching from or NULL, the node
762 * you pass will not be searched, only the next one
763 * will; typically, you pass what the previous call
764 * returned. of_node_put() will be called on it
765 * @matches: array of of device match structures to search in
766 * @match Updated to point at the matches entry which matched
767 *
768 * Returns a node pointer with refcount incremented, use
769 * of_node_put() on it when done.
770 */
of_find_matching_node_and_match(struct device_node * from,const struct of_device_id * matches,const struct of_device_id ** match)771 struct device_node *of_find_matching_node_and_match(struct device_node *from,
772 const struct of_device_id *matches,
773 const struct of_device_id **match)
774 {
775 struct device_node *np;
776 const struct of_device_id *m;
777 unsigned long flags;
778
779 if (match)
780 *match = NULL;
781
782 raw_spin_lock_irqsave(&devtree_lock, flags);
783 np = from ? from->allnext : of_allnodes;
784 for (; np; np = np->allnext) {
785 m = __of_match_node(matches, np);
786 if (m && of_node_get(np)) {
787 if (match)
788 *match = m;
789 break;
790 }
791 }
792 of_node_put(from);
793 raw_spin_unlock_irqrestore(&devtree_lock, flags);
794 return np;
795 }
796 EXPORT_SYMBOL(of_find_matching_node_and_match);
797
798 /**
799 * of_modalias_node - Lookup appropriate modalias for a device node
800 * @node: pointer to a device tree node
801 * @modalias: Pointer to buffer that modalias value will be copied into
802 * @len: Length of modalias value
803 *
804 * Based on the value of the compatible property, this routine will attempt
805 * to choose an appropriate modalias value for a particular device tree node.
806 * It does this by stripping the manufacturer prefix (as delimited by a ',')
807 * from the first entry in the compatible list property.
808 *
809 * This routine returns 0 on success, <0 on failure.
810 */
of_modalias_node(struct device_node * node,char * modalias,int len)811 int of_modalias_node(struct device_node *node, char *modalias, int len)
812 {
813 const char *compatible, *p;
814 int cplen;
815
816 compatible = of_get_property(node, "compatible", &cplen);
817 if (!compatible || strlen(compatible) > cplen)
818 return -ENODEV;
819 p = strchr(compatible, ',');
820 strlcpy(modalias, p ? p + 1 : compatible, len);
821 return 0;
822 }
823 EXPORT_SYMBOL_GPL(of_modalias_node);
824
825 /**
826 * of_find_node_by_phandle - Find a node given a phandle
827 * @handle: phandle of the node to find
828 *
829 * Returns a node pointer with refcount incremented, use
830 * of_node_put() on it when done.
831 */
of_find_node_by_phandle(phandle handle)832 struct device_node *of_find_node_by_phandle(phandle handle)
833 {
834 struct device_node *np;
835 unsigned long flags;
836
837 raw_spin_lock_irqsave(&devtree_lock, flags);
838 for (np = of_allnodes; np; np = np->allnext)
839 if (np->phandle == handle)
840 break;
841 of_node_get(np);
842 raw_spin_unlock_irqrestore(&devtree_lock, flags);
843 return np;
844 }
845 EXPORT_SYMBOL(of_find_node_by_phandle);
846
847 /**
848 * of_find_property_value_of_size
849 *
850 * @np: device node from which the property value is to be read.
851 * @propname: name of the property to be searched.
852 * @len: requested length of property value
853 *
854 * Search for a property in a device node and valid the requested size.
855 * Returns the property value on success, -EINVAL if the property does not
856 * exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
857 * property data isn't large enough.
858 *
859 */
of_find_property_value_of_size(const struct device_node * np,const char * propname,u32 len)860 static void *of_find_property_value_of_size(const struct device_node *np,
861 const char *propname, u32 len)
862 {
863 struct property *prop = of_find_property(np, propname, NULL);
864
865 if (!prop)
866 return ERR_PTR(-EINVAL);
867 if (!prop->value)
868 return ERR_PTR(-ENODATA);
869 if (len > prop->length)
870 return ERR_PTR(-EOVERFLOW);
871
872 return prop->value;
873 }
874
875 /**
876 * of_property_read_u32_index - Find and read a u32 from a multi-value property.
877 *
878 * @np: device node from which the property value is to be read.
879 * @propname: name of the property to be searched.
880 * @index: index of the u32 in the list of values
881 * @out_value: pointer to return value, modified only if no error.
882 *
883 * Search for a property in a device node and read nth 32-bit value from
884 * it. Returns 0 on success, -EINVAL if the property does not exist,
885 * -ENODATA if property does not have a value, and -EOVERFLOW if the
886 * property data isn't large enough.
887 *
888 * The out_value is modified only if a valid u32 value can be decoded.
889 */
of_property_read_u32_index(const struct device_node * np,const char * propname,u32 index,u32 * out_value)890 int of_property_read_u32_index(const struct device_node *np,
891 const char *propname,
892 u32 index, u32 *out_value)
893 {
894 const u32 *val = of_find_property_value_of_size(np, propname,
895 ((index + 1) * sizeof(*out_value)));
896
897 if (IS_ERR(val))
898 return PTR_ERR(val);
899
900 *out_value = be32_to_cpup(((__be32 *)val) + index);
901 return 0;
902 }
903 EXPORT_SYMBOL_GPL(of_property_read_u32_index);
904
905 /**
906 * of_property_read_u8_array - Find and read an array of u8 from a property.
907 *
908 * @np: device node from which the property value is to be read.
909 * @propname: name of the property to be searched.
910 * @out_value: pointer to return value, modified only if return value is 0.
911 * @sz: number of array elements to read
912 *
913 * Search for a property in a device node and read 8-bit value(s) from
914 * it. Returns 0 on success, -EINVAL if the property does not exist,
915 * -ENODATA if property does not have a value, and -EOVERFLOW if the
916 * property data isn't large enough.
917 *
918 * dts entry of array should be like:
919 * property = /bits/ 8 <0x50 0x60 0x70>;
920 *
921 * The out_value is modified only if a valid u8 value can be decoded.
922 */
of_property_read_u8_array(const struct device_node * np,const char * propname,u8 * out_values,size_t sz)923 int of_property_read_u8_array(const struct device_node *np,
924 const char *propname, u8 *out_values, size_t sz)
925 {
926 const u8 *val = of_find_property_value_of_size(np, propname,
927 (sz * sizeof(*out_values)));
928
929 if (IS_ERR(val))
930 return PTR_ERR(val);
931
932 while (sz--)
933 *out_values++ = *val++;
934 return 0;
935 }
936 EXPORT_SYMBOL_GPL(of_property_read_u8_array);
937
938 /**
939 * of_property_read_u16_array - Find and read an array of u16 from a property.
940 *
941 * @np: device node from which the property value is to be read.
942 * @propname: name of the property to be searched.
943 * @out_value: pointer to return value, modified only if return value is 0.
944 * @sz: number of array elements to read
945 *
946 * Search for a property in a device node and read 16-bit value(s) from
947 * it. Returns 0 on success, -EINVAL if the property does not exist,
948 * -ENODATA if property does not have a value, and -EOVERFLOW if the
949 * property data isn't large enough.
950 *
951 * dts entry of array should be like:
952 * property = /bits/ 16 <0x5000 0x6000 0x7000>;
953 *
954 * The out_value is modified only if a valid u16 value can be decoded.
955 */
of_property_read_u16_array(const struct device_node * np,const char * propname,u16 * out_values,size_t sz)956 int of_property_read_u16_array(const struct device_node *np,
957 const char *propname, u16 *out_values, size_t sz)
958 {
959 const __be16 *val = of_find_property_value_of_size(np, propname,
960 (sz * sizeof(*out_values)));
961
962 if (IS_ERR(val))
963 return PTR_ERR(val);
964
965 while (sz--)
966 *out_values++ = be16_to_cpup(val++);
967 return 0;
968 }
969 EXPORT_SYMBOL_GPL(of_property_read_u16_array);
970
971 /**
972 * of_property_read_u32_array - Find and read an array of 32 bit integers
973 * from a property.
974 *
975 * @np: device node from which the property value is to be read.
976 * @propname: name of the property to be searched.
977 * @out_value: pointer to return value, modified only if return value is 0.
978 * @sz: number of array elements to read
979 *
980 * Search for a property in a device node and read 32-bit value(s) from
981 * it. Returns 0 on success, -EINVAL if the property does not exist,
982 * -ENODATA if property does not have a value, and -EOVERFLOW if the
983 * property data isn't large enough.
984 *
985 * The out_value is modified only if a valid u32 value can be decoded.
986 */
of_property_read_u32_array(const struct device_node * np,const char * propname,u32 * out_values,size_t sz)987 int of_property_read_u32_array(const struct device_node *np,
988 const char *propname, u32 *out_values,
989 size_t sz)
990 {
991 const __be32 *val = of_find_property_value_of_size(np, propname,
992 (sz * sizeof(*out_values)));
993
994 if (IS_ERR(val))
995 return PTR_ERR(val);
996
997 while (sz--)
998 *out_values++ = be32_to_cpup(val++);
999 return 0;
1000 }
1001 EXPORT_SYMBOL_GPL(of_property_read_u32_array);
1002
1003 /**
1004 * of_property_read_u64 - Find and read a 64 bit integer from a property
1005 * @np: device node from which the property value is to be read.
1006 * @propname: name of the property to be searched.
1007 * @out_value: pointer to return value, modified only if return value is 0.
1008 *
1009 * Search for a property in a device node and read a 64-bit value from
1010 * it. Returns 0 on success, -EINVAL if the property does not exist,
1011 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1012 * property data isn't large enough.
1013 *
1014 * The out_value is modified only if a valid u64 value can be decoded.
1015 */
of_property_read_u64(const struct device_node * np,const char * propname,u64 * out_value)1016 int of_property_read_u64(const struct device_node *np, const char *propname,
1017 u64 *out_value)
1018 {
1019 const __be32 *val = of_find_property_value_of_size(np, propname,
1020 sizeof(*out_value));
1021
1022 if (IS_ERR(val))
1023 return PTR_ERR(val);
1024
1025 *out_value = of_read_number(val, 2);
1026 return 0;
1027 }
1028 EXPORT_SYMBOL_GPL(of_property_read_u64);
1029
1030 /**
1031 * of_property_read_string - Find and read a string from a property
1032 * @np: device node from which the property value is to be read.
1033 * @propname: name of the property to be searched.
1034 * @out_string: pointer to null terminated return string, modified only if
1035 * return value is 0.
1036 *
1037 * Search for a property in a device tree node and retrieve a null
1038 * terminated string value (pointer to data, not a copy). Returns 0 on
1039 * success, -EINVAL if the property does not exist, -ENODATA if property
1040 * does not have a value, and -EILSEQ if the string is not null-terminated
1041 * within the length of the property data.
1042 *
1043 * The out_string pointer is modified only if a valid string can be decoded.
1044 */
of_property_read_string(struct device_node * np,const char * propname,const char ** out_string)1045 int of_property_read_string(struct device_node *np, const char *propname,
1046 const char **out_string)
1047 {
1048 struct property *prop = of_find_property(np, propname, NULL);
1049 if (!prop)
1050 return -EINVAL;
1051 if (!prop->value)
1052 return -ENODATA;
1053 if (strnlen(prop->value, prop->length) >= prop->length)
1054 return -EILSEQ;
1055 *out_string = prop->value;
1056 return 0;
1057 }
1058 EXPORT_SYMBOL_GPL(of_property_read_string);
1059
1060 /**
1061 * of_property_read_string_index - Find and read a string from a multiple
1062 * strings property.
1063 * @np: device node from which the property value is to be read.
1064 * @propname: name of the property to be searched.
1065 * @index: index of the string in the list of strings
1066 * @out_string: pointer to null terminated return string, modified only if
1067 * return value is 0.
1068 *
1069 * Search for a property in a device tree node and retrieve a null
1070 * terminated string value (pointer to data, not a copy) in the list of strings
1071 * contained in that property.
1072 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
1073 * property does not have a value, and -EILSEQ if the string is not
1074 * null-terminated within the length of the property data.
1075 *
1076 * The out_string pointer is modified only if a valid string can be decoded.
1077 */
of_property_read_string_index(struct device_node * np,const char * propname,int index,const char ** output)1078 int of_property_read_string_index(struct device_node *np, const char *propname,
1079 int index, const char **output)
1080 {
1081 struct property *prop = of_find_property(np, propname, NULL);
1082 int i = 0;
1083 size_t l = 0, total = 0;
1084 const char *p;
1085
1086 if (!prop)
1087 return -EINVAL;
1088 if (!prop->value)
1089 return -ENODATA;
1090 if (strnlen(prop->value, prop->length) >= prop->length)
1091 return -EILSEQ;
1092
1093 p = prop->value;
1094
1095 for (i = 0; total < prop->length; total += l, p += l) {
1096 l = strlen(p) + 1;
1097 if (i++ == index) {
1098 *output = p;
1099 return 0;
1100 }
1101 }
1102 return -ENODATA;
1103 }
1104 EXPORT_SYMBOL_GPL(of_property_read_string_index);
1105
1106 /**
1107 * of_property_match_string() - Find string in a list and return index
1108 * @np: pointer to node containing string list property
1109 * @propname: string list property name
1110 * @string: pointer to string to search for in string list
1111 *
1112 * This function searches a string list property and returns the index
1113 * of a specific string value.
1114 */
of_property_match_string(struct device_node * np,const char * propname,const char * string)1115 int of_property_match_string(struct device_node *np, const char *propname,
1116 const char *string)
1117 {
1118 struct property *prop = of_find_property(np, propname, NULL);
1119 size_t l;
1120 int i;
1121 const char *p, *end;
1122
1123 if (!prop)
1124 return -EINVAL;
1125 if (!prop->value)
1126 return -ENODATA;
1127
1128 p = prop->value;
1129 end = p + prop->length;
1130
1131 for (i = 0; p < end; i++, p += l) {
1132 l = strlen(p) + 1;
1133 if (p + l > end)
1134 return -EILSEQ;
1135 pr_debug("comparing %s with %s\n", string, p);
1136 if (strcmp(string, p) == 0)
1137 return i; /* Found it; return index */
1138 }
1139 return -ENODATA;
1140 }
1141 EXPORT_SYMBOL_GPL(of_property_match_string);
1142
1143 /**
1144 * of_property_count_strings - Find and return the number of strings from a
1145 * multiple strings property.
1146 * @np: device node from which the property value is to be read.
1147 * @propname: name of the property to be searched.
1148 *
1149 * Search for a property in a device tree node and retrieve the number of null
1150 * terminated string contain in it. Returns the number of strings on
1151 * success, -EINVAL if the property does not exist, -ENODATA if property
1152 * does not have a value, and -EILSEQ if the string is not null-terminated
1153 * within the length of the property data.
1154 */
of_property_count_strings(struct device_node * np,const char * propname)1155 int of_property_count_strings(struct device_node *np, const char *propname)
1156 {
1157 struct property *prop = of_find_property(np, propname, NULL);
1158 int i = 0;
1159 size_t l = 0, total = 0;
1160 const char *p;
1161
1162 if (!prop)
1163 return -EINVAL;
1164 if (!prop->value)
1165 return -ENODATA;
1166 if (strnlen(prop->value, prop->length) >= prop->length)
1167 return -EILSEQ;
1168
1169 p = prop->value;
1170
1171 for (i = 0; total < prop->length; total += l, p += l, i++)
1172 l = strlen(p) + 1;
1173
1174 return i;
1175 }
1176 EXPORT_SYMBOL_GPL(of_property_count_strings);
1177
1178 /**
1179 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1180 * @np: Pointer to device node holding phandle property
1181 * @phandle_name: Name of property holding a phandle value
1182 * @index: For properties holding a table of phandles, this is the index into
1183 * the table
1184 *
1185 * Returns the device_node pointer with refcount incremented. Use
1186 * of_node_put() on it when done.
1187 */
of_parse_phandle(const struct device_node * np,const char * phandle_name,int index)1188 struct device_node *of_parse_phandle(const struct device_node *np,
1189 const char *phandle_name, int index)
1190 {
1191 const __be32 *phandle;
1192 int size;
1193
1194 phandle = of_get_property(np, phandle_name, &size);
1195 if ((!phandle) || (size < sizeof(*phandle) * (index + 1)))
1196 return NULL;
1197
1198 return of_find_node_by_phandle(be32_to_cpup(phandle + index));
1199 }
1200 EXPORT_SYMBOL(of_parse_phandle);
1201
1202 /**
1203 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1204 * @np: pointer to a device tree node containing a list
1205 * @list_name: property name that contains a list
1206 * @cells_name: property name that specifies phandles' arguments count
1207 * @index: index of a phandle to parse out
1208 * @out_args: optional pointer to output arguments structure (will be filled)
1209 *
1210 * This function is useful to parse lists of phandles and their arguments.
1211 * Returns 0 on success and fills out_args, on error returns appropriate
1212 * errno value.
1213 *
1214 * Caller is responsible to call of_node_put() on the returned out_args->node
1215 * pointer.
1216 *
1217 * Example:
1218 *
1219 * phandle1: node1 {
1220 * #list-cells = <2>;
1221 * }
1222 *
1223 * phandle2: node2 {
1224 * #list-cells = <1>;
1225 * }
1226 *
1227 * node3 {
1228 * list = <&phandle1 1 2 &phandle2 3>;
1229 * }
1230 *
1231 * To get a device_node of the `node2' node you may call this:
1232 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1233 */
__of_parse_phandle_with_args(const struct device_node * np,const char * list_name,const char * cells_name,int index,struct of_phandle_args * out_args)1234 static int __of_parse_phandle_with_args(const struct device_node *np,
1235 const char *list_name,
1236 const char *cells_name, int index,
1237 struct of_phandle_args *out_args)
1238 {
1239 const __be32 *list, *list_end;
1240 int rc = 0, size, cur_index = 0;
1241 uint32_t count = 0;
1242 struct device_node *node = NULL;
1243 phandle phandle;
1244
1245 /* Retrieve the phandle list property */
1246 list = of_get_property(np, list_name, &size);
1247 if (!list)
1248 return -ENOENT;
1249 list_end = list + size / sizeof(*list);
1250
1251 /* Loop over the phandles until all the requested entry is found */
1252 while (list < list_end) {
1253 rc = -EINVAL;
1254 count = 0;
1255
1256 /*
1257 * If phandle is 0, then it is an empty entry with no
1258 * arguments. Skip forward to the next entry.
1259 */
1260 phandle = be32_to_cpup(list++);
1261 if (phandle) {
1262 /*
1263 * Find the provider node and parse the #*-cells
1264 * property to determine the argument length
1265 */
1266 node = of_find_node_by_phandle(phandle);
1267 if (!node) {
1268 pr_err("%s: could not find phandle\n",
1269 np->full_name);
1270 goto err;
1271 }
1272 if (of_property_read_u32(node, cells_name, &count)) {
1273 pr_err("%s: could not get %s for %s\n",
1274 np->full_name, cells_name,
1275 node->full_name);
1276 goto err;
1277 }
1278
1279 /*
1280 * Make sure that the arguments actually fit in the
1281 * remaining property data length
1282 */
1283 if (list + count > list_end) {
1284 pr_err("%s: arguments longer than property\n",
1285 np->full_name);
1286 goto err;
1287 }
1288 }
1289
1290 /*
1291 * All of the error cases above bail out of the loop, so at
1292 * this point, the parsing is successful. If the requested
1293 * index matches, then fill the out_args structure and return,
1294 * or return -ENOENT for an empty entry.
1295 */
1296 rc = -ENOENT;
1297 if (cur_index == index) {
1298 if (!phandle)
1299 goto err;
1300
1301 if (out_args) {
1302 int i;
1303 if (WARN_ON(count > MAX_PHANDLE_ARGS))
1304 count = MAX_PHANDLE_ARGS;
1305 out_args->np = node;
1306 out_args->args_count = count;
1307 for (i = 0; i < count; i++)
1308 out_args->args[i] = be32_to_cpup(list++);
1309 } else {
1310 of_node_put(node);
1311 }
1312
1313 /* Found it! return success */
1314 return 0;
1315 }
1316
1317 of_node_put(node);
1318 node = NULL;
1319 list += count;
1320 cur_index++;
1321 }
1322
1323 /*
1324 * Unlock node before returning result; will be one of:
1325 * -ENOENT : index is for empty phandle
1326 * -EINVAL : parsing error on data
1327 * [1..n] : Number of phandle (count mode; when index = -1)
1328 */
1329 rc = index < 0 ? cur_index : -ENOENT;
1330 err:
1331 if (node)
1332 of_node_put(node);
1333 return rc;
1334 }
1335
of_parse_phandle_with_args(const struct device_node * np,const char * list_name,const char * cells_name,int index,struct of_phandle_args * out_args)1336 int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1337 const char *cells_name, int index,
1338 struct of_phandle_args *out_args)
1339 {
1340 if (index < 0)
1341 return -EINVAL;
1342 return __of_parse_phandle_with_args(np, list_name, cells_name, index, out_args);
1343 }
1344 EXPORT_SYMBOL(of_parse_phandle_with_args);
1345
1346 /**
1347 * of_count_phandle_with_args() - Find the number of phandles references in a property
1348 * @np: pointer to a device tree node containing a list
1349 * @list_name: property name that contains a list
1350 * @cells_name: property name that specifies phandles' arguments count
1351 *
1352 * Returns the number of phandle + argument tuples within a property. It
1353 * is a typical pattern to encode a list of phandle and variable
1354 * arguments into a single property. The number of arguments is encoded
1355 * by a property in the phandle-target node. For example, a gpios
1356 * property would contain a list of GPIO specifies consisting of a
1357 * phandle and 1 or more arguments. The number of arguments are
1358 * determined by the #gpio-cells property in the node pointed to by the
1359 * phandle.
1360 */
of_count_phandle_with_args(const struct device_node * np,const char * list_name,const char * cells_name)1361 int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1362 const char *cells_name)
1363 {
1364 return __of_parse_phandle_with_args(np, list_name, cells_name, -1, NULL);
1365 }
1366 EXPORT_SYMBOL(of_count_phandle_with_args);
1367
1368 #if defined(CONFIG_OF_DYNAMIC)
of_property_notify(int action,struct device_node * np,struct property * prop)1369 static int of_property_notify(int action, struct device_node *np,
1370 struct property *prop)
1371 {
1372 struct of_prop_reconfig pr;
1373
1374 pr.dn = np;
1375 pr.prop = prop;
1376 return of_reconfig_notify(action, &pr);
1377 }
1378 #else
of_property_notify(int action,struct device_node * np,struct property * prop)1379 static int of_property_notify(int action, struct device_node *np,
1380 struct property *prop)
1381 {
1382 return 0;
1383 }
1384 #endif
1385
1386 /**
1387 * of_add_property - Add a property to a node
1388 */
of_add_property(struct device_node * np,struct property * prop)1389 int of_add_property(struct device_node *np, struct property *prop)
1390 {
1391 struct property **next;
1392 unsigned long flags;
1393 int rc;
1394
1395 rc = of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop);
1396 if (rc)
1397 return rc;
1398
1399 prop->next = NULL;
1400 raw_spin_lock_irqsave(&devtree_lock, flags);
1401 next = &np->properties;
1402 while (*next) {
1403 if (strcmp(prop->name, (*next)->name) == 0) {
1404 /* duplicate ! don't insert it */
1405 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1406 return -1;
1407 }
1408 next = &(*next)->next;
1409 }
1410 *next = prop;
1411 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1412
1413 #ifdef CONFIG_PROC_DEVICETREE
1414 /* try to add to proc as well if it was initialized */
1415 if (np->pde)
1416 proc_device_tree_add_prop(np->pde, prop);
1417 #endif /* CONFIG_PROC_DEVICETREE */
1418
1419 return 0;
1420 }
1421
1422 /**
1423 * of_remove_property - Remove a property from a node.
1424 *
1425 * Note that we don't actually remove it, since we have given out
1426 * who-knows-how-many pointers to the data using get-property.
1427 * Instead we just move the property to the "dead properties"
1428 * list, so it won't be found any more.
1429 */
of_remove_property(struct device_node * np,struct property * prop)1430 int of_remove_property(struct device_node *np, struct property *prop)
1431 {
1432 struct property **next;
1433 unsigned long flags;
1434 int found = 0;
1435 int rc;
1436
1437 rc = of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop);
1438 if (rc)
1439 return rc;
1440
1441 raw_spin_lock_irqsave(&devtree_lock, flags);
1442 next = &np->properties;
1443 while (*next) {
1444 if (*next == prop) {
1445 /* found the node */
1446 *next = prop->next;
1447 prop->next = np->deadprops;
1448 np->deadprops = prop;
1449 found = 1;
1450 break;
1451 }
1452 next = &(*next)->next;
1453 }
1454 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1455
1456 if (!found)
1457 return -ENODEV;
1458
1459 #ifdef CONFIG_PROC_DEVICETREE
1460 /* try to remove the proc node as well */
1461 if (np->pde)
1462 proc_device_tree_remove_prop(np->pde, prop);
1463 #endif /* CONFIG_PROC_DEVICETREE */
1464
1465 return 0;
1466 }
1467
1468 /*
1469 * of_update_property - Update a property in a node, if the property does
1470 * not exist, add it.
1471 *
1472 * Note that we don't actually remove it, since we have given out
1473 * who-knows-how-many pointers to the data using get-property.
1474 * Instead we just move the property to the "dead properties" list,
1475 * and add the new property to the property list
1476 */
of_update_property(struct device_node * np,struct property * newprop)1477 int of_update_property(struct device_node *np, struct property *newprop)
1478 {
1479 struct property **next, *oldprop;
1480 unsigned long flags;
1481 int rc, found = 0;
1482
1483 rc = of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop);
1484 if (rc)
1485 return rc;
1486
1487 if (!newprop->name)
1488 return -EINVAL;
1489
1490 oldprop = of_find_property(np, newprop->name, NULL);
1491 if (!oldprop)
1492 return of_add_property(np, newprop);
1493
1494 raw_spin_lock_irqsave(&devtree_lock, flags);
1495 next = &np->properties;
1496 while (*next) {
1497 if (*next == oldprop) {
1498 /* found the node */
1499 newprop->next = oldprop->next;
1500 *next = newprop;
1501 oldprop->next = np->deadprops;
1502 np->deadprops = oldprop;
1503 found = 1;
1504 break;
1505 }
1506 next = &(*next)->next;
1507 }
1508 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1509
1510 if (!found)
1511 return -ENODEV;
1512
1513 #ifdef CONFIG_PROC_DEVICETREE
1514 /* try to add to proc as well if it was initialized */
1515 if (np->pde)
1516 proc_device_tree_update_prop(np->pde, newprop, oldprop);
1517 #endif /* CONFIG_PROC_DEVICETREE */
1518
1519 return 0;
1520 }
1521
1522 #if defined(CONFIG_OF_DYNAMIC)
1523 /*
1524 * Support for dynamic device trees.
1525 *
1526 * On some platforms, the device tree can be manipulated at runtime.
1527 * The routines in this section support adding, removing and changing
1528 * device tree nodes.
1529 */
1530
1531 static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain);
1532
of_reconfig_notifier_register(struct notifier_block * nb)1533 int of_reconfig_notifier_register(struct notifier_block *nb)
1534 {
1535 return blocking_notifier_chain_register(&of_reconfig_chain, nb);
1536 }
1537 EXPORT_SYMBOL_GPL(of_reconfig_notifier_register);
1538
of_reconfig_notifier_unregister(struct notifier_block * nb)1539 int of_reconfig_notifier_unregister(struct notifier_block *nb)
1540 {
1541 return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
1542 }
1543 EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);
1544
of_reconfig_notify(unsigned long action,void * p)1545 int of_reconfig_notify(unsigned long action, void *p)
1546 {
1547 int rc;
1548
1549 rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
1550 return notifier_to_errno(rc);
1551 }
1552
1553 #ifdef CONFIG_PROC_DEVICETREE
of_add_proc_dt_entry(struct device_node * dn)1554 static void of_add_proc_dt_entry(struct device_node *dn)
1555 {
1556 struct proc_dir_entry *ent;
1557
1558 ent = proc_mkdir(strrchr(dn->full_name, '/') + 1, dn->parent->pde);
1559 if (ent)
1560 proc_device_tree_add_node(dn, ent);
1561 }
1562 #else
of_add_proc_dt_entry(struct device_node * dn)1563 static void of_add_proc_dt_entry(struct device_node *dn)
1564 {
1565 return;
1566 }
1567 #endif
1568
1569 /**
1570 * of_attach_node - Plug a device node into the tree and global list.
1571 */
of_attach_node(struct device_node * np)1572 int of_attach_node(struct device_node *np)
1573 {
1574 unsigned long flags;
1575 int rc;
1576
1577 rc = of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, np);
1578 if (rc)
1579 return rc;
1580
1581 raw_spin_lock_irqsave(&devtree_lock, flags);
1582 np->sibling = np->parent->child;
1583 np->allnext = of_allnodes;
1584 np->parent->child = np;
1585 of_allnodes = np;
1586 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1587
1588 of_add_proc_dt_entry(np);
1589 return 0;
1590 }
1591
1592 #ifdef CONFIG_PROC_DEVICETREE
of_remove_proc_dt_entry(struct device_node * dn)1593 static void of_remove_proc_dt_entry(struct device_node *dn)
1594 {
1595 proc_remove(dn->pde);
1596 }
1597 #else
of_remove_proc_dt_entry(struct device_node * dn)1598 static void of_remove_proc_dt_entry(struct device_node *dn)
1599 {
1600 return;
1601 }
1602 #endif
1603
1604 /**
1605 * of_detach_node - "Unplug" a node from the device tree.
1606 *
1607 * The caller must hold a reference to the node. The memory associated with
1608 * the node is not freed until its refcount goes to zero.
1609 */
of_detach_node(struct device_node * np)1610 int of_detach_node(struct device_node *np)
1611 {
1612 struct device_node *parent;
1613 unsigned long flags;
1614 int rc = 0;
1615
1616 rc = of_reconfig_notify(OF_RECONFIG_DETACH_NODE, np);
1617 if (rc)
1618 return rc;
1619
1620 raw_spin_lock_irqsave(&devtree_lock, flags);
1621
1622 if (of_node_check_flag(np, OF_DETACHED)) {
1623 /* someone already detached it */
1624 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1625 return rc;
1626 }
1627
1628 parent = np->parent;
1629 if (!parent) {
1630 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1631 return rc;
1632 }
1633
1634 if (of_allnodes == np)
1635 of_allnodes = np->allnext;
1636 else {
1637 struct device_node *prev;
1638 for (prev = of_allnodes;
1639 prev->allnext != np;
1640 prev = prev->allnext)
1641 ;
1642 prev->allnext = np->allnext;
1643 }
1644
1645 if (parent->child == np)
1646 parent->child = np->sibling;
1647 else {
1648 struct device_node *prevsib;
1649 for (prevsib = np->parent->child;
1650 prevsib->sibling != np;
1651 prevsib = prevsib->sibling)
1652 ;
1653 prevsib->sibling = np->sibling;
1654 }
1655
1656 of_node_set_flag(np, OF_DETACHED);
1657 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1658
1659 of_remove_proc_dt_entry(np);
1660 return rc;
1661 }
1662 #endif /* defined(CONFIG_OF_DYNAMIC) */
1663
of_alias_add(struct alias_prop * ap,struct device_node * np,int id,const char * stem,int stem_len)1664 static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1665 int id, const char *stem, int stem_len)
1666 {
1667 ap->np = np;
1668 ap->id = id;
1669 strncpy(ap->stem, stem, stem_len);
1670 ap->stem[stem_len] = 0;
1671 list_add_tail(&ap->link, &aliases_lookup);
1672 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
1673 ap->alias, ap->stem, ap->id, of_node_full_name(np));
1674 }
1675
1676 /**
1677 * of_alias_scan - Scan all properties of 'aliases' node
1678 *
1679 * The function scans all the properties of 'aliases' node and populate
1680 * the the global lookup table with the properties. It returns the
1681 * number of alias_prop found, or error code in error case.
1682 *
1683 * @dt_alloc: An allocator that provides a virtual address to memory
1684 * for the resulting tree
1685 */
of_alias_scan(void * (* dt_alloc)(u64 size,u64 align))1686 void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1687 {
1688 struct property *pp;
1689
1690 of_chosen = of_find_node_by_path("/chosen");
1691 if (of_chosen == NULL)
1692 of_chosen = of_find_node_by_path("/chosen@0");
1693 of_aliases = of_find_node_by_path("/aliases");
1694 if (!of_aliases)
1695 return;
1696
1697 for_each_property_of_node(of_aliases, pp) {
1698 const char *start = pp->name;
1699 const char *end = start + strlen(start);
1700 struct device_node *np;
1701 struct alias_prop *ap;
1702 int id, len;
1703
1704 /* Skip those we do not want to proceed */
1705 if (!strcmp(pp->name, "name") ||
1706 !strcmp(pp->name, "phandle") ||
1707 !strcmp(pp->name, "linux,phandle"))
1708 continue;
1709
1710 np = of_find_node_by_path(pp->value);
1711 if (!np)
1712 continue;
1713
1714 /* walk the alias backwards to extract the id and work out
1715 * the 'stem' string */
1716 while (isdigit(*(end-1)) && end > start)
1717 end--;
1718 len = end - start;
1719
1720 if (kstrtoint(end, 10, &id) < 0)
1721 continue;
1722
1723 /* Allocate an alias_prop with enough space for the stem */
1724 ap = dt_alloc(sizeof(*ap) + len + 1, 4);
1725 if (!ap)
1726 continue;
1727 ap->alias = start;
1728 of_alias_add(ap, np, id, start, len);
1729 }
1730 }
1731
1732 /**
1733 * of_alias_get_id - Get alias id for the given device_node
1734 * @np: Pointer to the given device_node
1735 * @stem: Alias stem of the given device_node
1736 *
1737 * The function travels the lookup table to get alias id for the given
1738 * device_node and alias stem. It returns the alias id if find it.
1739 */
of_alias_get_id(struct device_node * np,const char * stem)1740 int of_alias_get_id(struct device_node *np, const char *stem)
1741 {
1742 struct alias_prop *app;
1743 int id = -ENODEV;
1744
1745 mutex_lock(&of_aliases_mutex);
1746 list_for_each_entry(app, &aliases_lookup, link) {
1747 if (strcmp(app->stem, stem) != 0)
1748 continue;
1749
1750 if (np == app->np) {
1751 id = app->id;
1752 break;
1753 }
1754 }
1755 mutex_unlock(&of_aliases_mutex);
1756
1757 return id;
1758 }
1759 EXPORT_SYMBOL_GPL(of_alias_get_id);
1760
of_prop_next_u32(struct property * prop,const __be32 * cur,u32 * pu)1761 const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
1762 u32 *pu)
1763 {
1764 const void *curv = cur;
1765
1766 if (!prop)
1767 return NULL;
1768
1769 if (!cur) {
1770 curv = prop->value;
1771 goto out_val;
1772 }
1773
1774 curv += sizeof(*cur);
1775 if (curv >= prop->value + prop->length)
1776 return NULL;
1777
1778 out_val:
1779 *pu = be32_to_cpup(curv);
1780 return curv;
1781 }
1782 EXPORT_SYMBOL_GPL(of_prop_next_u32);
1783
of_prop_next_string(struct property * prop,const char * cur)1784 const char *of_prop_next_string(struct property *prop, const char *cur)
1785 {
1786 const void *curv = cur;
1787
1788 if (!prop)
1789 return NULL;
1790
1791 if (!cur)
1792 return prop->value;
1793
1794 curv += strlen(cur) + 1;
1795 if (curv >= prop->value + prop->length)
1796 return NULL;
1797
1798 return curv;
1799 }
1800 EXPORT_SYMBOL_GPL(of_prop_next_string);
1801