Loading...
Note: File does not exist in v3.1.
1/*
2 * Support for dynamic device trees.
3 *
4 * On some platforms, the device tree can be manipulated at runtime.
5 * The routines in this section support adding, removing and changing
6 * device tree nodes.
7 */
8
9#define pr_fmt(fmt) "OF: " fmt
10
11#include <linux/of.h>
12#include <linux/spinlock.h>
13#include <linux/slab.h>
14#include <linux/string.h>
15#include <linux/proc_fs.h>
16
17#include "of_private.h"
18
19/**
20 * of_node_get() - Increment refcount of a node
21 * @node: Node to inc refcount, NULL is supported to simplify writing of
22 * callers
23 *
24 * Returns node.
25 */
26struct device_node *of_node_get(struct device_node *node)
27{
28 if (node)
29 kobject_get(&node->kobj);
30 return node;
31}
32EXPORT_SYMBOL(of_node_get);
33
34/**
35 * of_node_put() - Decrement refcount of a node
36 * @node: Node to dec refcount, NULL is supported to simplify writing of
37 * callers
38 */
39void of_node_put(struct device_node *node)
40{
41 if (node)
42 kobject_put(&node->kobj);
43}
44EXPORT_SYMBOL(of_node_put);
45
46void __of_detach_node_sysfs(struct device_node *np)
47{
48 struct property *pp;
49
50 if (!IS_ENABLED(CONFIG_SYSFS))
51 return;
52
53 BUG_ON(!of_node_is_initialized(np));
54 if (!of_kset)
55 return;
56
57 /* only remove properties if on sysfs */
58 if (of_node_is_attached(np)) {
59 for_each_property_of_node(np, pp)
60 __of_sysfs_remove_bin_file(np, pp);
61 kobject_del(&np->kobj);
62 }
63
64 /* finally remove the kobj_init ref */
65 of_node_put(np);
66}
67
68static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain);
69
70int of_reconfig_notifier_register(struct notifier_block *nb)
71{
72 return blocking_notifier_chain_register(&of_reconfig_chain, nb);
73}
74EXPORT_SYMBOL_GPL(of_reconfig_notifier_register);
75
76int of_reconfig_notifier_unregister(struct notifier_block *nb)
77{
78 return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
79}
80EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);
81
82#ifdef DEBUG
83const char *action_names[] = {
84 [OF_RECONFIG_ATTACH_NODE] = "ATTACH_NODE",
85 [OF_RECONFIG_DETACH_NODE] = "DETACH_NODE",
86 [OF_RECONFIG_ADD_PROPERTY] = "ADD_PROPERTY",
87 [OF_RECONFIG_REMOVE_PROPERTY] = "REMOVE_PROPERTY",
88 [OF_RECONFIG_UPDATE_PROPERTY] = "UPDATE_PROPERTY",
89};
90#endif
91
92int of_reconfig_notify(unsigned long action, struct of_reconfig_data *p)
93{
94 int rc;
95#ifdef DEBUG
96 struct of_reconfig_data *pr = p;
97
98 switch (action) {
99 case OF_RECONFIG_ATTACH_NODE:
100 case OF_RECONFIG_DETACH_NODE:
101 pr_debug("notify %-15s %s\n", action_names[action],
102 pr->dn->full_name);
103 break;
104 case OF_RECONFIG_ADD_PROPERTY:
105 case OF_RECONFIG_REMOVE_PROPERTY:
106 case OF_RECONFIG_UPDATE_PROPERTY:
107 pr_debug("notify %-15s %s:%s\n", action_names[action],
108 pr->dn->full_name, pr->prop->name);
109 break;
110
111 }
112#endif
113 rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
114 return notifier_to_errno(rc);
115}
116
117/*
118 * of_reconfig_get_state_change() - Returns new state of device
119 * @action - action of the of notifier
120 * @arg - argument of the of notifier
121 *
122 * Returns the new state of a device based on the notifier used.
123 * Returns 0 on device going from enabled to disabled, 1 on device
124 * going from disabled to enabled and -1 on no change.
125 */
126int of_reconfig_get_state_change(unsigned long action, struct of_reconfig_data *pr)
127{
128 struct property *prop, *old_prop = NULL;
129 int is_status, status_state, old_status_state, prev_state, new_state;
130
131 /* figure out if a device should be created or destroyed */
132 switch (action) {
133 case OF_RECONFIG_ATTACH_NODE:
134 case OF_RECONFIG_DETACH_NODE:
135 prop = of_find_property(pr->dn, "status", NULL);
136 break;
137 case OF_RECONFIG_ADD_PROPERTY:
138 case OF_RECONFIG_REMOVE_PROPERTY:
139 prop = pr->prop;
140 break;
141 case OF_RECONFIG_UPDATE_PROPERTY:
142 prop = pr->prop;
143 old_prop = pr->old_prop;
144 break;
145 default:
146 return OF_RECONFIG_NO_CHANGE;
147 }
148
149 is_status = 0;
150 status_state = -1;
151 old_status_state = -1;
152 prev_state = -1;
153 new_state = -1;
154
155 if (prop && !strcmp(prop->name, "status")) {
156 is_status = 1;
157 status_state = !strcmp(prop->value, "okay") ||
158 !strcmp(prop->value, "ok");
159 if (old_prop)
160 old_status_state = !strcmp(old_prop->value, "okay") ||
161 !strcmp(old_prop->value, "ok");
162 }
163
164 switch (action) {
165 case OF_RECONFIG_ATTACH_NODE:
166 prev_state = 0;
167 /* -1 & 0 status either missing or okay */
168 new_state = status_state != 0;
169 break;
170 case OF_RECONFIG_DETACH_NODE:
171 /* -1 & 0 status either missing or okay */
172 prev_state = status_state != 0;
173 new_state = 0;
174 break;
175 case OF_RECONFIG_ADD_PROPERTY:
176 if (is_status) {
177 /* no status property -> enabled (legacy) */
178 prev_state = 1;
179 new_state = status_state;
180 }
181 break;
182 case OF_RECONFIG_REMOVE_PROPERTY:
183 if (is_status) {
184 prev_state = status_state;
185 /* no status property -> enabled (legacy) */
186 new_state = 1;
187 }
188 break;
189 case OF_RECONFIG_UPDATE_PROPERTY:
190 if (is_status) {
191 prev_state = old_status_state != 0;
192 new_state = status_state != 0;
193 }
194 break;
195 }
196
197 if (prev_state == new_state)
198 return OF_RECONFIG_NO_CHANGE;
199
200 return new_state ? OF_RECONFIG_CHANGE_ADD : OF_RECONFIG_CHANGE_REMOVE;
201}
202EXPORT_SYMBOL_GPL(of_reconfig_get_state_change);
203
204int of_property_notify(int action, struct device_node *np,
205 struct property *prop, struct property *oldprop)
206{
207 struct of_reconfig_data pr;
208
209 /* only call notifiers if the node is attached */
210 if (!of_node_is_attached(np))
211 return 0;
212
213 pr.dn = np;
214 pr.prop = prop;
215 pr.old_prop = oldprop;
216 return of_reconfig_notify(action, &pr);
217}
218
219void __of_attach_node(struct device_node *np)
220{
221 const __be32 *phandle;
222 int sz;
223
224 np->name = __of_get_property(np, "name", NULL) ? : "<NULL>";
225 np->type = __of_get_property(np, "device_type", NULL) ? : "<NULL>";
226
227 phandle = __of_get_property(np, "phandle", &sz);
228 if (!phandle)
229 phandle = __of_get_property(np, "linux,phandle", &sz);
230 if (IS_ENABLED(CONFIG_PPC_PSERIES) && !phandle)
231 phandle = __of_get_property(np, "ibm,phandle", &sz);
232 np->phandle = (phandle && (sz >= 4)) ? be32_to_cpup(phandle) : 0;
233
234 np->child = NULL;
235 np->sibling = np->parent->child;
236 np->parent->child = np;
237 of_node_clear_flag(np, OF_DETACHED);
238}
239
240/**
241 * of_attach_node() - Plug a device node into the tree and global list.
242 */
243int of_attach_node(struct device_node *np)
244{
245 struct of_reconfig_data rd;
246 unsigned long flags;
247
248 memset(&rd, 0, sizeof(rd));
249 rd.dn = np;
250
251 mutex_lock(&of_mutex);
252 raw_spin_lock_irqsave(&devtree_lock, flags);
253 __of_attach_node(np);
254 raw_spin_unlock_irqrestore(&devtree_lock, flags);
255
256 __of_attach_node_sysfs(np);
257 mutex_unlock(&of_mutex);
258
259 of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, &rd);
260
261 return 0;
262}
263
264void __of_detach_node(struct device_node *np)
265{
266 struct device_node *parent;
267
268 if (WARN_ON(of_node_check_flag(np, OF_DETACHED)))
269 return;
270
271 parent = np->parent;
272 if (WARN_ON(!parent))
273 return;
274
275 if (parent->child == np)
276 parent->child = np->sibling;
277 else {
278 struct device_node *prevsib;
279 for (prevsib = np->parent->child;
280 prevsib->sibling != np;
281 prevsib = prevsib->sibling)
282 ;
283 prevsib->sibling = np->sibling;
284 }
285
286 of_node_set_flag(np, OF_DETACHED);
287}
288
289/**
290 * of_detach_node() - "Unplug" a node from the device tree.
291 *
292 * The caller must hold a reference to the node. The memory associated with
293 * the node is not freed until its refcount goes to zero.
294 */
295int of_detach_node(struct device_node *np)
296{
297 struct of_reconfig_data rd;
298 unsigned long flags;
299 int rc = 0;
300
301 memset(&rd, 0, sizeof(rd));
302 rd.dn = np;
303
304 mutex_lock(&of_mutex);
305 raw_spin_lock_irqsave(&devtree_lock, flags);
306 __of_detach_node(np);
307 raw_spin_unlock_irqrestore(&devtree_lock, flags);
308
309 __of_detach_node_sysfs(np);
310 mutex_unlock(&of_mutex);
311
312 of_reconfig_notify(OF_RECONFIG_DETACH_NODE, &rd);
313
314 return rc;
315}
316EXPORT_SYMBOL_GPL(of_detach_node);
317
318/**
319 * of_node_release() - release a dynamically allocated node
320 * @kref: kref element of the node to be released
321 *
322 * In of_node_put() this function is passed to kref_put() as the destructor.
323 */
324void of_node_release(struct kobject *kobj)
325{
326 struct device_node *node = kobj_to_device_node(kobj);
327 struct property *prop = node->properties;
328
329 /* We should never be releasing nodes that haven't been detached. */
330 if (!of_node_check_flag(node, OF_DETACHED)) {
331 pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name);
332 dump_stack();
333 return;
334 }
335
336 if (!of_node_check_flag(node, OF_DYNAMIC))
337 return;
338
339 while (prop) {
340 struct property *next = prop->next;
341 kfree(prop->name);
342 kfree(prop->value);
343 kfree(prop);
344 prop = next;
345
346 if (!prop) {
347 prop = node->deadprops;
348 node->deadprops = NULL;
349 }
350 }
351 kfree(node->full_name);
352 kfree(node->data);
353 kfree(node);
354}
355
356/**
357 * __of_prop_dup - Copy a property dynamically.
358 * @prop: Property to copy
359 * @allocflags: Allocation flags (typically pass GFP_KERNEL)
360 *
361 * Copy a property by dynamically allocating the memory of both the
362 * property structure and the property name & contents. The property's
363 * flags have the OF_DYNAMIC bit set so that we can differentiate between
364 * dynamically allocated properties and not.
365 * Returns the newly allocated property or NULL on out of memory error.
366 */
367struct property *__of_prop_dup(const struct property *prop, gfp_t allocflags)
368{
369 struct property *new;
370
371 new = kzalloc(sizeof(*new), allocflags);
372 if (!new)
373 return NULL;
374
375 /*
376 * NOTE: There is no check for zero length value.
377 * In case of a boolean property, this will allocate a value
378 * of zero bytes. We do this to work around the use
379 * of of_get_property() calls on boolean values.
380 */
381 new->name = kstrdup(prop->name, allocflags);
382 new->value = kmemdup(prop->value, prop->length, allocflags);
383 new->length = prop->length;
384 if (!new->name || !new->value)
385 goto err_free;
386
387 /* mark the property as dynamic */
388 of_property_set_flag(new, OF_DYNAMIC);
389
390 return new;
391
392 err_free:
393 kfree(new->name);
394 kfree(new->value);
395 kfree(new);
396 return NULL;
397}
398
399/**
400 * __of_node_dup() - Duplicate or create an empty device node dynamically.
401 * @fmt: Format string (plus vargs) for new full name of the device node
402 *
403 * Create an device tree node, either by duplicating an empty node or by allocating
404 * an empty one suitable for further modification. The node data are
405 * dynamically allocated and all the node flags have the OF_DYNAMIC &
406 * OF_DETACHED bits set. Returns the newly allocated node or NULL on out of
407 * memory error.
408 */
409struct device_node *__of_node_dup(const struct device_node *np, const char *fmt, ...)
410{
411 va_list vargs;
412 struct device_node *node;
413
414 node = kzalloc(sizeof(*node), GFP_KERNEL);
415 if (!node)
416 return NULL;
417 va_start(vargs, fmt);
418 node->full_name = kvasprintf(GFP_KERNEL, fmt, vargs);
419 va_end(vargs);
420 if (!node->full_name) {
421 kfree(node);
422 return NULL;
423 }
424
425 of_node_set_flag(node, OF_DYNAMIC);
426 of_node_set_flag(node, OF_DETACHED);
427 of_node_init(node);
428
429 /* Iterate over and duplicate all properties */
430 if (np) {
431 struct property *pp, *new_pp;
432 for_each_property_of_node(np, pp) {
433 new_pp = __of_prop_dup(pp, GFP_KERNEL);
434 if (!new_pp)
435 goto err_prop;
436 if (__of_add_property(node, new_pp)) {
437 kfree(new_pp->name);
438 kfree(new_pp->value);
439 kfree(new_pp);
440 goto err_prop;
441 }
442 }
443 }
444 return node;
445
446 err_prop:
447 of_node_put(node); /* Frees the node and properties */
448 return NULL;
449}
450
451static void __of_changeset_entry_destroy(struct of_changeset_entry *ce)
452{
453 of_node_put(ce->np);
454 list_del(&ce->node);
455 kfree(ce);
456}
457
458#ifdef DEBUG
459static void __of_changeset_entry_dump(struct of_changeset_entry *ce)
460{
461 switch (ce->action) {
462 case OF_RECONFIG_ADD_PROPERTY:
463 case OF_RECONFIG_REMOVE_PROPERTY:
464 case OF_RECONFIG_UPDATE_PROPERTY:
465 pr_debug("cset<%p> %-15s %s/%s\n", ce, action_names[ce->action],
466 ce->np->full_name, ce->prop->name);
467 break;
468 case OF_RECONFIG_ATTACH_NODE:
469 case OF_RECONFIG_DETACH_NODE:
470 pr_debug("cset<%p> %-15s %s\n", ce, action_names[ce->action],
471 ce->np->full_name);
472 break;
473 }
474}
475#else
476static inline void __of_changeset_entry_dump(struct of_changeset_entry *ce)
477{
478 /* empty */
479}
480#endif
481
482static void __of_changeset_entry_invert(struct of_changeset_entry *ce,
483 struct of_changeset_entry *rce)
484{
485 memcpy(rce, ce, sizeof(*rce));
486
487 switch (ce->action) {
488 case OF_RECONFIG_ATTACH_NODE:
489 rce->action = OF_RECONFIG_DETACH_NODE;
490 break;
491 case OF_RECONFIG_DETACH_NODE:
492 rce->action = OF_RECONFIG_ATTACH_NODE;
493 break;
494 case OF_RECONFIG_ADD_PROPERTY:
495 rce->action = OF_RECONFIG_REMOVE_PROPERTY;
496 break;
497 case OF_RECONFIG_REMOVE_PROPERTY:
498 rce->action = OF_RECONFIG_ADD_PROPERTY;
499 break;
500 case OF_RECONFIG_UPDATE_PROPERTY:
501 rce->old_prop = ce->prop;
502 rce->prop = ce->old_prop;
503 /* update was used but original property did not exist */
504 if (!rce->prop) {
505 rce->action = OF_RECONFIG_REMOVE_PROPERTY;
506 rce->prop = ce->prop;
507 }
508 break;
509 }
510}
511
512static void __of_changeset_entry_notify(struct of_changeset_entry *ce, bool revert)
513{
514 struct of_reconfig_data rd;
515 struct of_changeset_entry ce_inverted;
516 int ret;
517
518 if (revert) {
519 __of_changeset_entry_invert(ce, &ce_inverted);
520 ce = &ce_inverted;
521 }
522
523 switch (ce->action) {
524 case OF_RECONFIG_ATTACH_NODE:
525 case OF_RECONFIG_DETACH_NODE:
526 memset(&rd, 0, sizeof(rd));
527 rd.dn = ce->np;
528 ret = of_reconfig_notify(ce->action, &rd);
529 break;
530 case OF_RECONFIG_ADD_PROPERTY:
531 case OF_RECONFIG_REMOVE_PROPERTY:
532 case OF_RECONFIG_UPDATE_PROPERTY:
533 ret = of_property_notify(ce->action, ce->np, ce->prop, ce->old_prop);
534 break;
535 default:
536 pr_err("invalid devicetree changeset action: %i\n",
537 (int)ce->action);
538 return;
539 }
540
541 if (ret)
542 pr_err("changeset notifier error @%s\n", ce->np->full_name);
543}
544
545static int __of_changeset_entry_apply(struct of_changeset_entry *ce)
546{
547 struct property *old_prop, **propp;
548 unsigned long flags;
549 int ret = 0;
550
551 __of_changeset_entry_dump(ce);
552
553 raw_spin_lock_irqsave(&devtree_lock, flags);
554 switch (ce->action) {
555 case OF_RECONFIG_ATTACH_NODE:
556 __of_attach_node(ce->np);
557 break;
558 case OF_RECONFIG_DETACH_NODE:
559 __of_detach_node(ce->np);
560 break;
561 case OF_RECONFIG_ADD_PROPERTY:
562 /* If the property is in deadprops then it must be removed */
563 for (propp = &ce->np->deadprops; *propp; propp = &(*propp)->next) {
564 if (*propp == ce->prop) {
565 *propp = ce->prop->next;
566 ce->prop->next = NULL;
567 break;
568 }
569 }
570
571 ret = __of_add_property(ce->np, ce->prop);
572 if (ret) {
573 pr_err("changeset: add_property failed @%s/%s\n",
574 ce->np->full_name,
575 ce->prop->name);
576 break;
577 }
578 break;
579 case OF_RECONFIG_REMOVE_PROPERTY:
580 ret = __of_remove_property(ce->np, ce->prop);
581 if (ret) {
582 pr_err("changeset: remove_property failed @%s/%s\n",
583 ce->np->full_name,
584 ce->prop->name);
585 break;
586 }
587 break;
588
589 case OF_RECONFIG_UPDATE_PROPERTY:
590 /* If the property is in deadprops then it must be removed */
591 for (propp = &ce->np->deadprops; *propp; propp = &(*propp)->next) {
592 if (*propp == ce->prop) {
593 *propp = ce->prop->next;
594 ce->prop->next = NULL;
595 break;
596 }
597 }
598
599 ret = __of_update_property(ce->np, ce->prop, &old_prop);
600 if (ret) {
601 pr_err("changeset: update_property failed @%s/%s\n",
602 ce->np->full_name,
603 ce->prop->name);
604 break;
605 }
606 break;
607 default:
608 ret = -EINVAL;
609 }
610 raw_spin_unlock_irqrestore(&devtree_lock, flags);
611
612 if (ret)
613 return ret;
614
615 switch (ce->action) {
616 case OF_RECONFIG_ATTACH_NODE:
617 __of_attach_node_sysfs(ce->np);
618 break;
619 case OF_RECONFIG_DETACH_NODE:
620 __of_detach_node_sysfs(ce->np);
621 break;
622 case OF_RECONFIG_ADD_PROPERTY:
623 /* ignore duplicate names */
624 __of_add_property_sysfs(ce->np, ce->prop);
625 break;
626 case OF_RECONFIG_REMOVE_PROPERTY:
627 __of_remove_property_sysfs(ce->np, ce->prop);
628 break;
629 case OF_RECONFIG_UPDATE_PROPERTY:
630 __of_update_property_sysfs(ce->np, ce->prop, ce->old_prop);
631 break;
632 }
633
634 return 0;
635}
636
637static inline int __of_changeset_entry_revert(struct of_changeset_entry *ce)
638{
639 struct of_changeset_entry ce_inverted;
640
641 __of_changeset_entry_invert(ce, &ce_inverted);
642 return __of_changeset_entry_apply(&ce_inverted);
643}
644
645/**
646 * of_changeset_init - Initialize a changeset for use
647 *
648 * @ocs: changeset pointer
649 *
650 * Initialize a changeset structure
651 */
652void of_changeset_init(struct of_changeset *ocs)
653{
654 memset(ocs, 0, sizeof(*ocs));
655 INIT_LIST_HEAD(&ocs->entries);
656}
657EXPORT_SYMBOL_GPL(of_changeset_init);
658
659/**
660 * of_changeset_destroy - Destroy a changeset
661 *
662 * @ocs: changeset pointer
663 *
664 * Destroys a changeset. Note that if a changeset is applied,
665 * its changes to the tree cannot be reverted.
666 */
667void of_changeset_destroy(struct of_changeset *ocs)
668{
669 struct of_changeset_entry *ce, *cen;
670
671 list_for_each_entry_safe_reverse(ce, cen, &ocs->entries, node)
672 __of_changeset_entry_destroy(ce);
673}
674EXPORT_SYMBOL_GPL(of_changeset_destroy);
675
676int __of_changeset_apply(struct of_changeset *ocs)
677{
678 struct of_changeset_entry *ce;
679 int ret;
680
681 /* perform the rest of the work */
682 pr_debug("changeset: applying...\n");
683 list_for_each_entry(ce, &ocs->entries, node) {
684 ret = __of_changeset_entry_apply(ce);
685 if (ret) {
686 pr_err("Error applying changeset (%d)\n", ret);
687 list_for_each_entry_continue_reverse(ce, &ocs->entries, node)
688 __of_changeset_entry_revert(ce);
689 return ret;
690 }
691 }
692 pr_debug("changeset: applied, emitting notifiers.\n");
693
694 /* drop the global lock while emitting notifiers */
695 mutex_unlock(&of_mutex);
696 list_for_each_entry(ce, &ocs->entries, node)
697 __of_changeset_entry_notify(ce, 0);
698 mutex_lock(&of_mutex);
699 pr_debug("changeset: notifiers sent.\n");
700
701 return 0;
702}
703
704/**
705 * of_changeset_apply - Applies a changeset
706 *
707 * @ocs: changeset pointer
708 *
709 * Applies a changeset to the live tree.
710 * Any side-effects of live tree state changes are applied here on
711 * success, like creation/destruction of devices and side-effects
712 * like creation of sysfs properties and directories.
713 * Returns 0 on success, a negative error value in case of an error.
714 * On error the partially applied effects are reverted.
715 */
716int of_changeset_apply(struct of_changeset *ocs)
717{
718 int ret;
719
720 mutex_lock(&of_mutex);
721 ret = __of_changeset_apply(ocs);
722 mutex_unlock(&of_mutex);
723
724 return ret;
725}
726EXPORT_SYMBOL_GPL(of_changeset_apply);
727
728int __of_changeset_revert(struct of_changeset *ocs)
729{
730 struct of_changeset_entry *ce;
731 int ret;
732
733 pr_debug("changeset: reverting...\n");
734 list_for_each_entry_reverse(ce, &ocs->entries, node) {
735 ret = __of_changeset_entry_revert(ce);
736 if (ret) {
737 pr_err("Error reverting changeset (%d)\n", ret);
738 list_for_each_entry_continue(ce, &ocs->entries, node)
739 __of_changeset_entry_apply(ce);
740 return ret;
741 }
742 }
743 pr_debug("changeset: reverted, emitting notifiers.\n");
744
745 /* drop the global lock while emitting notifiers */
746 mutex_unlock(&of_mutex);
747 list_for_each_entry_reverse(ce, &ocs->entries, node)
748 __of_changeset_entry_notify(ce, 1);
749 mutex_lock(&of_mutex);
750 pr_debug("changeset: notifiers sent.\n");
751
752 return 0;
753}
754
755/**
756 * of_changeset_revert - Reverts an applied changeset
757 *
758 * @ocs: changeset pointer
759 *
760 * Reverts a changeset returning the state of the tree to what it
761 * was before the application.
762 * Any side-effects like creation/destruction of devices and
763 * removal of sysfs properties and directories are applied.
764 * Returns 0 on success, a negative error value in case of an error.
765 */
766int of_changeset_revert(struct of_changeset *ocs)
767{
768 int ret;
769
770 mutex_lock(&of_mutex);
771 ret = __of_changeset_revert(ocs);
772 mutex_unlock(&of_mutex);
773
774 return ret;
775}
776EXPORT_SYMBOL_GPL(of_changeset_revert);
777
778/**
779 * of_changeset_action - Perform a changeset action
780 *
781 * @ocs: changeset pointer
782 * @action: action to perform
783 * @np: Pointer to device node
784 * @prop: Pointer to property
785 *
786 * On action being one of:
787 * + OF_RECONFIG_ATTACH_NODE
788 * + OF_RECONFIG_DETACH_NODE,
789 * + OF_RECONFIG_ADD_PROPERTY
790 * + OF_RECONFIG_REMOVE_PROPERTY,
791 * + OF_RECONFIG_UPDATE_PROPERTY
792 * Returns 0 on success, a negative error value in case of an error.
793 */
794int of_changeset_action(struct of_changeset *ocs, unsigned long action,
795 struct device_node *np, struct property *prop)
796{
797 struct of_changeset_entry *ce;
798
799 ce = kzalloc(sizeof(*ce), GFP_KERNEL);
800 if (!ce)
801 return -ENOMEM;
802
803 /* get a reference to the node */
804 ce->action = action;
805 ce->np = of_node_get(np);
806 ce->prop = prop;
807
808 if (action == OF_RECONFIG_UPDATE_PROPERTY && prop)
809 ce->old_prop = of_find_property(np, prop->name, NULL);
810
811 /* add it to the list */
812 list_add_tail(&ce->node, &ocs->entries);
813 return 0;
814}
815EXPORT_SYMBOL_GPL(of_changeset_action);