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1 /*
2 * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
3 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * Standard functionality for the common clock API. See Documentation/clk.txt
10 */
11
12 #include <linux/clk-private.h>
13 #include <linux/module.h>
14 #include <linux/mutex.h>
15 #include <linux/spinlock.h>
16 #include <linux/err.h>
17 #include <linux/list.h>
18 #include <linux/slab.h>
19
20 static DEFINE_SPINLOCK(enable_lock);
21 static DEFINE_MUTEX(prepare_lock);
22
23 static HLIST_HEAD(clk_root_list);
24 static HLIST_HEAD(clk_orphan_list);
25 static LIST_HEAD(clk_notifier_list);
26
27 /*** debugfs support ***/
28
29 #ifdef CONFIG_COMMON_CLK_DEBUG
30 #include <linux/debugfs.h>
31
32 static struct dentry *rootdir;
33 static struct dentry *orphandir;
34 static int inited = 0;
35
36 /* caller must hold prepare_lock */
37 static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry)
38 {
39 struct dentry *d;
40 int ret = -ENOMEM;
41
42 if (!clk || !pdentry) {
43 ret = -EINVAL;
44 goto out;
45 }
46
47 d = debugfs_create_dir(clk->name, pdentry);
48 if (!d)
49 goto out;
50
51 clk->dentry = d;
52
53 d = debugfs_create_u32("clk_rate", S_IRUGO, clk->dentry,
54 (u32 *)&clk->rate);
55 if (!d)
56 goto err_out;
57
58 d = debugfs_create_x32("clk_flags", S_IRUGO, clk->dentry,
59 (u32 *)&clk->flags);
60 if (!d)
61 goto err_out;
62
63 d = debugfs_create_u32("clk_prepare_count", S_IRUGO, clk->dentry,
64 (u32 *)&clk->prepare_count);
65 if (!d)
66 goto err_out;
67
68 d = debugfs_create_u32("clk_enable_count", S_IRUGO, clk->dentry,
69 (u32 *)&clk->enable_count);
70 if (!d)
71 goto err_out;
72
73 d = debugfs_create_u32("clk_notifier_count", S_IRUGO, clk->dentry,
74 (u32 *)&clk->notifier_count);
75 if (!d)
76 goto err_out;
77
78 ret = 0;
79 goto out;
80
81 err_out:
82 debugfs_remove(clk->dentry);
83 out:
84 return ret;
85 }
86
87 /* caller must hold prepare_lock */
88 static int clk_debug_create_subtree(struct clk *clk, struct dentry *pdentry)
89 {
90 struct clk *child;
91 struct hlist_node *tmp;
92 int ret = -EINVAL;;
93
94 if (!clk || !pdentry)
95 goto out;
96
97 ret = clk_debug_create_one(clk, pdentry);
98
99 if (ret)
100 goto out;
101
102 hlist_for_each_entry(child, tmp, &clk->children, child_node)
103 clk_debug_create_subtree(child, clk->dentry);
104
105 ret = 0;
106 out:
107 return ret;
108 }
109
110 /**
111 * clk_debug_register - add a clk node to the debugfs clk tree
112 * @clk: the clk being added to the debugfs clk tree
113 *
114 * Dynamically adds a clk to the debugfs clk tree if debugfs has been
115 * initialized. Otherwise it bails out early since the debugfs clk tree
116 * will be created lazily by clk_debug_init as part of a late_initcall.
117 *
118 * Caller must hold prepare_lock. Only clk_init calls this function (so
119 * far) so this is taken care.
120 */
121 static int clk_debug_register(struct clk *clk)
122 {
123 struct clk *parent;
124 struct dentry *pdentry;
125 int ret = 0;
126
127 if (!inited)
128 goto out;
129
130 parent = clk->parent;
131
132 /*
133 * Check to see if a clk is a root clk. Also check that it is
134 * safe to add this clk to debugfs
135 */
136 if (!parent)
137 if (clk->flags & CLK_IS_ROOT)
138 pdentry = rootdir;
139 else
140 pdentry = orphandir;
141 else
142 if (parent->dentry)
143 pdentry = parent->dentry;
144 else
145 goto out;
146
147 ret = clk_debug_create_subtree(clk, pdentry);
148
149 out:
150 return ret;
151 }
152
153 /**
154 * clk_debug_init - lazily create the debugfs clk tree visualization
155 *
156 * clks are often initialized very early during boot before memory can
157 * be dynamically allocated and well before debugfs is setup.
158 * clk_debug_init walks the clk tree hierarchy while holding
159 * prepare_lock and creates the topology as part of a late_initcall,
160 * thus insuring that clks initialized very early will still be
161 * represented in the debugfs clk tree. This function should only be
162 * called once at boot-time, and all other clks added dynamically will
163 * be done so with clk_debug_register.
164 */
165 static int __init clk_debug_init(void)
166 {
167 struct clk *clk;
168 struct hlist_node *tmp;
169
170 rootdir = debugfs_create_dir("clk", NULL);
171
172 if (!rootdir)
173 return -ENOMEM;
174
175 orphandir = debugfs_create_dir("orphans", rootdir);
176
177 if (!orphandir)
178 return -ENOMEM;
179
180 mutex_lock(&prepare_lock);
181
182 hlist_for_each_entry(clk, tmp, &clk_root_list, child_node)
183 clk_debug_create_subtree(clk, rootdir);
184
185 hlist_for_each_entry(clk, tmp, &clk_orphan_list, child_node)
186 clk_debug_create_subtree(clk, orphandir);
187
188 inited = 1;
189
190 mutex_unlock(&prepare_lock);
191
192 return 0;
193 }
194 late_initcall(clk_debug_init);
195 #else
196 static inline int clk_debug_register(struct clk *clk) { return 0; }
197 #endif
198
199 #ifdef CONFIG_COMMON_CLK_DISABLE_UNUSED
200 /* caller must hold prepare_lock */
201 static void clk_disable_unused_subtree(struct clk *clk)
202 {
203 struct clk *child;
204 struct hlist_node *tmp;
205 unsigned long flags;
206
207 if (!clk)
208 goto out;
209
210 hlist_for_each_entry(child, tmp, &clk->children, child_node)
211 clk_disable_unused_subtree(child);
212
213 spin_lock_irqsave(&enable_lock, flags);
214
215 if (clk->enable_count)
216 goto unlock_out;
217
218 if (clk->flags & CLK_IGNORE_UNUSED)
219 goto unlock_out;
220
221 if (__clk_is_enabled(clk) && clk->ops->disable)
222 clk->ops->disable(clk->hw);
223
224 unlock_out:
225 spin_unlock_irqrestore(&enable_lock, flags);
226
227 out:
228 return;
229 }
230
231 static int clk_disable_unused(void)
232 {
233 struct clk *clk;
234 struct hlist_node *tmp;
235
236 mutex_lock(&prepare_lock);
237
238 hlist_for_each_entry(clk, tmp, &clk_root_list, child_node)
239 clk_disable_unused_subtree(clk);
240
241 hlist_for_each_entry(clk, tmp, &clk_orphan_list, child_node)
242 clk_disable_unused_subtree(clk);
243
244 mutex_unlock(&prepare_lock);
245
246 return 0;
247 }
248 late_initcall(clk_disable_unused);
249 #endif
250
251 /*** helper functions ***/
252
253 inline const char *__clk_get_name(struct clk *clk)
254 {
255 return !clk ? NULL : clk->name;
256 }
257
258 inline struct clk_hw *__clk_get_hw(struct clk *clk)
259 {
260 return !clk ? NULL : clk->hw;
261 }
262
263 inline u8 __clk_get_num_parents(struct clk *clk)
264 {
265 return !clk ? -EINVAL : clk->num_parents;
266 }
267
268 inline struct clk *__clk_get_parent(struct clk *clk)
269 {
270 return !clk ? NULL : clk->parent;
271 }
272
273 inline int __clk_get_enable_count(struct clk *clk)
274 {
275 return !clk ? -EINVAL : clk->enable_count;
276 }
277
278 inline int __clk_get_prepare_count(struct clk *clk)
279 {
280 return !clk ? -EINVAL : clk->prepare_count;
281 }
282
283 unsigned long __clk_get_rate(struct clk *clk)
284 {
285 unsigned long ret;
286
287 if (!clk) {
288 ret = 0;
289 goto out;
290 }
291
292 ret = clk->rate;
293
294 if (clk->flags & CLK_IS_ROOT)
295 goto out;
296
297 if (!clk->parent)
298 ret = 0;
299
300 out:
301 return ret;
302 }
303
304 inline unsigned long __clk_get_flags(struct clk *clk)
305 {
306 return !clk ? -EINVAL : clk->flags;
307 }
308
309 int __clk_is_enabled(struct clk *clk)
310 {
311 int ret;
312
313 if (!clk)
314 return -EINVAL;
315
316 /*
317 * .is_enabled is only mandatory for clocks that gate
318 * fall back to software usage counter if .is_enabled is missing
319 */
320 if (!clk->ops->is_enabled) {
321 ret = clk->enable_count ? 1 : 0;
322 goto out;
323 }
324
325 ret = clk->ops->is_enabled(clk->hw);
326 out:
327 return ret;
328 }
329
330 static struct clk *__clk_lookup_subtree(const char *name, struct clk *clk)
331 {
332 struct clk *child;
333 struct clk *ret;
334 struct hlist_node *tmp;
335
336 if (!strcmp(clk->name, name))
337 return clk;
338
339 hlist_for_each_entry(child, tmp, &clk->children, child_node) {
340 ret = __clk_lookup_subtree(name, child);
341 if (ret)
342 return ret;
343 }
344
345 return NULL;
346 }
347
348 struct clk *__clk_lookup(const char *name)
349 {
350 struct clk *root_clk;
351 struct clk *ret;
352 struct hlist_node *tmp;
353
354 if (!name)
355 return NULL;
356
357 /* search the 'proper' clk tree first */
358 hlist_for_each_entry(root_clk, tmp, &clk_root_list, child_node) {
359 ret = __clk_lookup_subtree(name, root_clk);
360 if (ret)
361 return ret;
362 }
363
364 /* if not found, then search the orphan tree */
365 hlist_for_each_entry(root_clk, tmp, &clk_orphan_list, child_node) {
366 ret = __clk_lookup_subtree(name, root_clk);
367 if (ret)
368 return ret;
369 }
370
371 return NULL;
372 }
373
374 /*** clk api ***/
375
376 void __clk_unprepare(struct clk *clk)
377 {
378 if (!clk)
379 return;
380
381 if (WARN_ON(clk->prepare_count == 0))
382 return;
383
384 if (--clk->prepare_count > 0)
385 return;
386
387 WARN_ON(clk->enable_count > 0);
388
389 if (clk->ops->unprepare)
390 clk->ops->unprepare(clk->hw);
391
392 __clk_unprepare(clk->parent);
393 }
394
395 /**
396 * clk_unprepare - undo preparation of a clock source
397 * @clk: the clk being unprepare
398 *
399 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
400 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
401 * if the operation may sleep. One example is a clk which is accessed over
402 * I2c. In the complex case a clk gate operation may require a fast and a slow
403 * part. It is this reason that clk_unprepare and clk_disable are not mutually
404 * exclusive. In fact clk_disable must be called before clk_unprepare.
405 */
406 void clk_unprepare(struct clk *clk)
407 {
408 mutex_lock(&prepare_lock);
409 __clk_unprepare(clk);
410 mutex_unlock(&prepare_lock);
411 }
412 EXPORT_SYMBOL_GPL(clk_unprepare);
413
414 int __clk_prepare(struct clk *clk)
415 {
416 int ret = 0;
417
418 if (!clk)
419 return 0;
420
421 if (clk->prepare_count == 0) {
422 ret = __clk_prepare(clk->parent);
423 if (ret)
424 return ret;
425
426 if (clk->ops->prepare) {
427 ret = clk->ops->prepare(clk->hw);
428 if (ret) {
429 __clk_unprepare(clk->parent);
430 return ret;
431 }
432 }
433 }
434
435 clk->prepare_count++;
436
437 return 0;
438 }
439
440 /**
441 * clk_prepare - prepare a clock source
442 * @clk: the clk being prepared
443 *
444 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
445 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
446 * operation may sleep. One example is a clk which is accessed over I2c. In
447 * the complex case a clk ungate operation may require a fast and a slow part.
448 * It is this reason that clk_prepare and clk_enable are not mutually
449 * exclusive. In fact clk_prepare must be called before clk_enable.
450 * Returns 0 on success, -EERROR otherwise.
451 */
452 int clk_prepare(struct clk *clk)
453 {
454 int ret;
455
456 mutex_lock(&prepare_lock);
457 ret = __clk_prepare(clk);
458 mutex_unlock(&prepare_lock);
459
460 return ret;
461 }
462 EXPORT_SYMBOL_GPL(clk_prepare);
463
464 static void __clk_disable(struct clk *clk)
465 {
466 if (!clk)
467 return;
468
469 if (WARN_ON(clk->enable_count == 0))
470 return;
471
472 if (--clk->enable_count > 0)
473 return;
474
475 if (clk->ops->disable)
476 clk->ops->disable(clk->hw);
477
478 __clk_disable(clk->parent);
479 }
480
481 /**
482 * clk_disable - gate a clock
483 * @clk: the clk being gated
484 *
485 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
486 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
487 * clk if the operation is fast and will never sleep. One example is a
488 * SoC-internal clk which is controlled via simple register writes. In the
489 * complex case a clk gate operation may require a fast and a slow part. It is
490 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
491 * In fact clk_disable must be called before clk_unprepare.
492 */
493 void clk_disable(struct clk *clk)
494 {
495 unsigned long flags;
496
497 spin_lock_irqsave(&enable_lock, flags);
498 __clk_disable(clk);
499 spin_unlock_irqrestore(&enable_lock, flags);
500 }
501 EXPORT_SYMBOL_GPL(clk_disable);
502
503 static int __clk_enable(struct clk *clk)
504 {
505 int ret = 0;
506
507 if (!clk)
508 return 0;
509
510 if (WARN_ON(clk->prepare_count == 0))
511 return -ESHUTDOWN;
512
513 if (clk->enable_count == 0) {
514 ret = __clk_enable(clk->parent);
515
516 if (ret)
517 return ret;
518
519 if (clk->ops->enable) {
520 ret = clk->ops->enable(clk->hw);
521 if (ret) {
522 __clk_disable(clk->parent);
523 return ret;
524 }
525 }
526 }
527
528 clk->enable_count++;
529 return 0;
530 }
531
532 /**
533 * clk_enable - ungate a clock
534 * @clk: the clk being ungated
535 *
536 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
537 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
538 * if the operation will never sleep. One example is a SoC-internal clk which
539 * is controlled via simple register writes. In the complex case a clk ungate
540 * operation may require a fast and a slow part. It is this reason that
541 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
542 * must be called before clk_enable. Returns 0 on success, -EERROR
543 * otherwise.
544 */
545 int clk_enable(struct clk *clk)
546 {
547 unsigned long flags;
548 int ret;
549
550 spin_lock_irqsave(&enable_lock, flags);
551 ret = __clk_enable(clk);
552 spin_unlock_irqrestore(&enable_lock, flags);
553
554 return ret;
555 }
556 EXPORT_SYMBOL_GPL(clk_enable);
557
558 /**
559 * clk_get_rate - return the rate of clk
560 * @clk: the clk whose rate is being returned
561 *
562 * Simply returns the cached rate of the clk. Does not query the hardware. If
563 * clk is NULL then returns 0.
564 */
565 unsigned long clk_get_rate(struct clk *clk)
566 {
567 unsigned long rate;
568
569 mutex_lock(&prepare_lock);
570 rate = __clk_get_rate(clk);
571 mutex_unlock(&prepare_lock);
572
573 return rate;
574 }
575 EXPORT_SYMBOL_GPL(clk_get_rate);
576
577 /**
578 * __clk_round_rate - round the given rate for a clk
579 * @clk: round the rate of this clock
580 *
581 * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate
582 */
583 unsigned long __clk_round_rate(struct clk *clk, unsigned long rate)
584 {
585 unsigned long parent_rate = 0;
586
587 if (!clk)
588 return -EINVAL;
589
590 if (!clk->ops->round_rate) {
591 if (clk->flags & CLK_SET_RATE_PARENT)
592 return __clk_round_rate(clk->parent, rate);
593 else
594 return clk->rate;
595 }
596
597 if (clk->parent)
598 parent_rate = clk->parent->rate;
599
600 return clk->ops->round_rate(clk->hw, rate, &parent_rate);
601 }
602
603 /**
604 * clk_round_rate - round the given rate for a clk
605 * @clk: the clk for which we are rounding a rate
606 * @rate: the rate which is to be rounded
607 *
608 * Takes in a rate as input and rounds it to a rate that the clk can actually
609 * use which is then returned. If clk doesn't support round_rate operation
610 * then the parent rate is returned.
611 */
612 long clk_round_rate(struct clk *clk, unsigned long rate)
613 {
614 unsigned long ret;
615
616 mutex_lock(&prepare_lock);
617 ret = __clk_round_rate(clk, rate);
618 mutex_unlock(&prepare_lock);
619
620 return ret;
621 }
622 EXPORT_SYMBOL_GPL(clk_round_rate);
623
624 /**
625 * __clk_notify - call clk notifier chain
626 * @clk: struct clk * that is changing rate
627 * @msg: clk notifier type (see include/linux/clk.h)
628 * @old_rate: old clk rate
629 * @new_rate: new clk rate
630 *
631 * Triggers a notifier call chain on the clk rate-change notification
632 * for 'clk'. Passes a pointer to the struct clk and the previous
633 * and current rates to the notifier callback. Intended to be called by
634 * internal clock code only. Returns NOTIFY_DONE from the last driver
635 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
636 * a driver returns that.
637 */
638 static int __clk_notify(struct clk *clk, unsigned long msg,
639 unsigned long old_rate, unsigned long new_rate)
640 {
641 struct clk_notifier *cn;
642 struct clk_notifier_data cnd;
643 int ret = NOTIFY_DONE;
644
645 cnd.clk = clk;
646 cnd.old_rate = old_rate;
647 cnd.new_rate = new_rate;
648
649 list_for_each_entry(cn, &clk_notifier_list, node) {
650 if (cn->clk == clk) {
651 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
652 &cnd);
653 break;
654 }
655 }
656
657 return ret;
658 }
659
660 /**
661 * __clk_recalc_rates
662 * @clk: first clk in the subtree
663 * @msg: notification type (see include/linux/clk.h)
664 *
665 * Walks the subtree of clks starting with clk and recalculates rates as it
666 * goes. Note that if a clk does not implement the .recalc_rate callback then
667 * it is assumed that the clock will take on the rate of it's parent.
668 *
669 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
670 * if necessary.
671 *
672 * Caller must hold prepare_lock.
673 */
674 static void __clk_recalc_rates(struct clk *clk, unsigned long msg)
675 {
676 unsigned long old_rate;
677 unsigned long parent_rate = 0;
678 struct hlist_node *tmp;
679 struct clk *child;
680
681 old_rate = clk->rate;
682
683 if (clk->parent)
684 parent_rate = clk->parent->rate;
685
686 if (clk->ops->recalc_rate)
687 clk->rate = clk->ops->recalc_rate(clk->hw, parent_rate);
688 else
689 clk->rate = parent_rate;
690
691 /*
692 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
693 * & ABORT_RATE_CHANGE notifiers
694 */
695 if (clk->notifier_count && msg)
696 __clk_notify(clk, msg, old_rate, clk->rate);
697
698 hlist_for_each_entry(child, tmp, &clk->children, child_node)
699 __clk_recalc_rates(child, msg);
700 }
701
702 /**
703 * __clk_speculate_rates
704 * @clk: first clk in the subtree
705 * @parent_rate: the "future" rate of clk's parent
706 *
707 * Walks the subtree of clks starting with clk, speculating rates as it
708 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
709 *
710 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
711 * pre-rate change notifications and returns early if no clks in the
712 * subtree have subscribed to the notifications. Note that if a clk does not
713 * implement the .recalc_rate callback then it is assumed that the clock will
714 * take on the rate of it's parent.
715 *
716 * Caller must hold prepare_lock.
717 */
718 static int __clk_speculate_rates(struct clk *clk, unsigned long parent_rate)
719 {
720 struct hlist_node *tmp;
721 struct clk *child;
722 unsigned long new_rate;
723 int ret = NOTIFY_DONE;
724
725 if (clk->ops->recalc_rate)
726 new_rate = clk->ops->recalc_rate(clk->hw, parent_rate);
727 else
728 new_rate = parent_rate;
729
730 /* abort the rate change if a driver returns NOTIFY_BAD */
731 if (clk->notifier_count)
732 ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate);
733
734 if (ret == NOTIFY_BAD)
735 goto out;
736
737 hlist_for_each_entry(child, tmp, &clk->children, child_node) {
738 ret = __clk_speculate_rates(child, new_rate);
739 if (ret == NOTIFY_BAD)
740 break;
741 }
742
743 out:
744 return ret;
745 }
746
747 static void clk_calc_subtree(struct clk *clk, unsigned long new_rate)
748 {
749 struct clk *child;
750 struct hlist_node *tmp;
751
752 clk->new_rate = new_rate;
753
754 hlist_for_each_entry(child, tmp, &clk->children, child_node) {
755 if (child->ops->recalc_rate)
756 child->new_rate = child->ops->recalc_rate(child->hw, new_rate);
757 else
758 child->new_rate = new_rate;
759 clk_calc_subtree(child, child->new_rate);
760 }
761 }
762
763 /*
764 * calculate the new rates returning the topmost clock that has to be
765 * changed.
766 */
767 static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate)
768 {
769 struct clk *top = clk;
770 unsigned long best_parent_rate = 0;
771 unsigned long new_rate;
772
773 /* sanity */
774 if (IS_ERR_OR_NULL(clk))
775 return NULL;
776
777 /* never propagate up to the parent */
778 if (!(clk->flags & CLK_SET_RATE_PARENT)) {
779 if (!clk->ops->round_rate) {
780 clk->new_rate = clk->rate;
781 return NULL;
782 }
783 }
784
785 /* need clk->parent from here on out */
786 if (!clk->parent) {
787 pr_debug("%s: %s has NULL parent\n", __func__, clk->name);
788 return NULL;
789 }
790
791 if (!clk->ops->round_rate) {
792 top = clk_calc_new_rates(clk->parent, rate);
793 new_rate = clk->parent->new_rate;
794
795 goto out;
796 }
797
798 best_parent_rate = clk->parent->rate;
799 new_rate = clk->ops->round_rate(clk->hw, rate, &best_parent_rate);
800
801 if (best_parent_rate != clk->parent->rate) {
802 top = clk_calc_new_rates(clk->parent, best_parent_rate);
803
804 goto out;
805 }
806
807 out:
808 clk_calc_subtree(clk, new_rate);
809
810 return top;
811 }
812
813 /*
814 * Notify about rate changes in a subtree. Always walk down the whole tree
815 * so that in case of an error we can walk down the whole tree again and
816 * abort the change.
817 */
818 static struct clk *clk_propagate_rate_change(struct clk *clk, unsigned long event)
819 {
820 struct hlist_node *tmp;
821 struct clk *child, *fail_clk = NULL;
822 int ret = NOTIFY_DONE;
823
824 if (clk->rate == clk->new_rate)
825 return 0;
826
827 if (clk->notifier_count) {
828 ret = __clk_notify(clk, event, clk->rate, clk->new_rate);
829 if (ret == NOTIFY_BAD)
830 fail_clk = clk;
831 }
832
833 hlist_for_each_entry(child, tmp, &clk->children, child_node) {
834 clk = clk_propagate_rate_change(child, event);
835 if (clk)
836 fail_clk = clk;
837 }
838
839 return fail_clk;
840 }
841
842 /*
843 * walk down a subtree and set the new rates notifying the rate
844 * change on the way
845 */
846 static void clk_change_rate(struct clk *clk)
847 {
848 struct clk *child;
849 unsigned long old_rate;
850 struct hlist_node *tmp;
851
852 old_rate = clk->rate;
853
854 if (clk->ops->set_rate)
855 clk->ops->set_rate(clk->hw, clk->new_rate, clk->parent->rate);
856
857 if (clk->ops->recalc_rate)
858 clk->rate = clk->ops->recalc_rate(clk->hw,
859 clk->parent->rate);
860 else
861 clk->rate = clk->parent->rate;
862
863 if (clk->notifier_count && old_rate != clk->rate)
864 __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate);
865
866 hlist_for_each_entry(child, tmp, &clk->children, child_node)
867 clk_change_rate(child);
868 }
869
870 /**
871 * clk_set_rate - specify a new rate for clk
872 * @clk: the clk whose rate is being changed
873 * @rate: the new rate for clk
874 *
875 * In the simplest case clk_set_rate will only adjust the rate of clk.
876 *
877 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
878 * propagate up to clk's parent; whether or not this happens depends on the
879 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
880 * after calling .round_rate then upstream parent propagation is ignored. If
881 * *parent_rate comes back with a new rate for clk's parent then we propagate
882 * up to clk's parent and set it's rate. Upward propagation will continue
883 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
884 * .round_rate stops requesting changes to clk's parent_rate.
885 *
886 * Rate changes are accomplished via tree traversal that also recalculates the
887 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
888 *
889 * Returns 0 on success, -EERROR otherwise.
890 */
891 int clk_set_rate(struct clk *clk, unsigned long rate)
892 {
893 struct clk *top, *fail_clk;
894 int ret = 0;
895
896 /* prevent racing with updates to the clock topology */
897 mutex_lock(&prepare_lock);
898
899 /* bail early if nothing to do */
900 if (rate == clk->rate)
901 goto out;
902
903 /* calculate new rates and get the topmost changed clock */
904 top = clk_calc_new_rates(clk, rate);
905 if (!top) {
906 ret = -EINVAL;
907 goto out;
908 }
909
910 /* notify that we are about to change rates */
911 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
912 if (fail_clk) {
913 pr_warn("%s: failed to set %s rate\n", __func__,
914 fail_clk->name);
915 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
916 ret = -EBUSY;
917 goto out;
918 }
919
920 /* change the rates */
921 clk_change_rate(top);
922
923 mutex_unlock(&prepare_lock);
924
925 return 0;
926 out:
927 mutex_unlock(&prepare_lock);
928
929 return ret;
930 }
931 EXPORT_SYMBOL_GPL(clk_set_rate);
932
933 /**
934 * clk_get_parent - return the parent of a clk
935 * @clk: the clk whose parent gets returned
936 *
937 * Simply returns clk->parent. Returns NULL if clk is NULL.
938 */
939 struct clk *clk_get_parent(struct clk *clk)
940 {
941 struct clk *parent;
942
943 mutex_lock(&prepare_lock);
944 parent = __clk_get_parent(clk);
945 mutex_unlock(&prepare_lock);
946
947 return parent;
948 }
949 EXPORT_SYMBOL_GPL(clk_get_parent);
950
951 /*
952 * .get_parent is mandatory for clocks with multiple possible parents. It is
953 * optional for single-parent clocks. Always call .get_parent if it is
954 * available and WARN if it is missing for multi-parent clocks.
955 *
956 * For single-parent clocks without .get_parent, first check to see if the
957 * .parents array exists, and if so use it to avoid an expensive tree
958 * traversal. If .parents does not exist then walk the tree with __clk_lookup.
959 */
960 static struct clk *__clk_init_parent(struct clk *clk)
961 {
962 struct clk *ret = NULL;
963 u8 index;
964
965 /* handle the trivial cases */
966
967 if (!clk->num_parents)
968 goto out;
969
970 if (clk->num_parents == 1) {
971 if (IS_ERR_OR_NULL(clk->parent))
972 ret = clk->parent = __clk_lookup(clk->parent_names[0]);
973 ret = clk->parent;
974 goto out;
975 }
976
977 if (!clk->ops->get_parent) {
978 WARN(!clk->ops->get_parent,
979 "%s: multi-parent clocks must implement .get_parent\n",
980 __func__);
981 goto out;
982 };
983
984 /*
985 * Do our best to cache parent clocks in clk->parents. This prevents
986 * unnecessary and expensive calls to __clk_lookup. We don't set
987 * clk->parent here; that is done by the calling function
988 */
989
990 index = clk->ops->get_parent(clk->hw);
991
992 if (!clk->parents)
993 clk->parents =
994 kmalloc((sizeof(struct clk*) * clk->num_parents),
995 GFP_KERNEL);
996
997 if (!clk->parents)
998 ret = __clk_lookup(clk->parent_names[index]);
999 else if (!clk->parents[index])
1000 ret = clk->parents[index] =
1001 __clk_lookup(clk->parent_names[index]);
1002 else
1003 ret = clk->parents[index];
1004
1005 out:
1006 return ret;
1007 }
1008
1009 void __clk_reparent(struct clk *clk, struct clk *new_parent)
1010 {
1011 #ifdef CONFIG_COMMON_CLK_DEBUG
1012 struct dentry *d;
1013 struct dentry *new_parent_d;
1014 #endif
1015
1016 if (!clk || !new_parent)
1017 return;
1018
1019 hlist_del(&clk->child_node);
1020
1021 if (new_parent)
1022 hlist_add_head(&clk->child_node, &new_parent->children);
1023 else
1024 hlist_add_head(&clk->child_node, &clk_orphan_list);
1025
1026 #ifdef CONFIG_COMMON_CLK_DEBUG
1027 if (!inited)
1028 goto out;
1029
1030 if (new_parent)
1031 new_parent_d = new_parent->dentry;
1032 else
1033 new_parent_d = orphandir;
1034
1035 d = debugfs_rename(clk->dentry->d_parent, clk->dentry,
1036 new_parent_d, clk->name);
1037 if (d)
1038 clk->dentry = d;
1039 else
1040 pr_debug("%s: failed to rename debugfs entry for %s\n",
1041 __func__, clk->name);
1042 out:
1043 #endif
1044
1045 clk->parent = new_parent;
1046
1047 __clk_recalc_rates(clk, POST_RATE_CHANGE);
1048 }
1049
1050 static int __clk_set_parent(struct clk *clk, struct clk *parent)
1051 {
1052 struct clk *old_parent;
1053 unsigned long flags;
1054 int ret = -EINVAL;
1055 u8 i;
1056
1057 old_parent = clk->parent;
1058
1059 /* find index of new parent clock using cached parent ptrs */
1060 for (i = 0; i < clk->num_parents; i++)
1061 if (clk->parents[i] == parent)
1062 break;
1063
1064 /*
1065 * find index of new parent clock using string name comparison
1066 * also try to cache the parent to avoid future calls to __clk_lookup
1067 */
1068 if (i == clk->num_parents)
1069 for (i = 0; i < clk->num_parents; i++)
1070 if (!strcmp(clk->parent_names[i], parent->name)) {
1071 clk->parents[i] = __clk_lookup(parent->name);
1072 break;
1073 }
1074
1075 if (i == clk->num_parents) {
1076 pr_debug("%s: clock %s is not a possible parent of clock %s\n",
1077 __func__, parent->name, clk->name);
1078 goto out;
1079 }
1080
1081 /* migrate prepare and enable */
1082 if (clk->prepare_count)
1083 __clk_prepare(parent);
1084
1085 /* FIXME replace with clk_is_enabled(clk) someday */
1086 spin_lock_irqsave(&enable_lock, flags);
1087 if (clk->enable_count)
1088 __clk_enable(parent);
1089 spin_unlock_irqrestore(&enable_lock, flags);
1090
1091 /* change clock input source */
1092 ret = clk->ops->set_parent(clk->hw, i);
1093
1094 /* clean up old prepare and enable */
1095 spin_lock_irqsave(&enable_lock, flags);
1096 if (clk->enable_count)
1097 __clk_disable(old_parent);
1098 spin_unlock_irqrestore(&enable_lock, flags);
1099
1100 if (clk->prepare_count)
1101 __clk_unprepare(old_parent);
1102
1103 out:
1104 return ret;
1105 }
1106
1107 /**
1108 * clk_set_parent - switch the parent of a mux clk
1109 * @clk: the mux clk whose input we are switching
1110 * @parent: the new input to clk
1111 *
1112 * Re-parent clk to use parent as it's new input source. If clk has the
1113 * CLK_SET_PARENT_GATE flag set then clk must be gated for this
1114 * operation to succeed. After successfully changing clk's parent
1115 * clk_set_parent will update the clk topology, sysfs topology and
1116 * propagate rate recalculation via __clk_recalc_rates. Returns 0 on
1117 * success, -EERROR otherwise.
1118 */
1119 int clk_set_parent(struct clk *clk, struct clk *parent)
1120 {
1121 int ret = 0;
1122
1123 if (!clk || !clk->ops)
1124 return -EINVAL;
1125
1126 if (!clk->ops->set_parent)
1127 return -ENOSYS;
1128
1129 /* prevent racing with updates to the clock topology */
1130 mutex_lock(&prepare_lock);
1131
1132 if (clk->parent == parent)
1133 goto out;
1134
1135 /* propagate PRE_RATE_CHANGE notifications */
1136 if (clk->notifier_count)
1137 ret = __clk_speculate_rates(clk, parent->rate);
1138
1139 /* abort if a driver objects */
1140 if (ret == NOTIFY_STOP)
1141 goto out;
1142
1143 /* only re-parent if the clock is not in use */
1144 if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count)
1145 ret = -EBUSY;
1146 else
1147 ret = __clk_set_parent(clk, parent);
1148
1149 /* propagate ABORT_RATE_CHANGE if .set_parent failed */
1150 if (ret) {
1151 __clk_recalc_rates(clk, ABORT_RATE_CHANGE);
1152 goto out;
1153 }
1154
1155 /* propagate rate recalculation downstream */
1156 __clk_reparent(clk, parent);
1157
1158 out:
1159 mutex_unlock(&prepare_lock);
1160
1161 return ret;
1162 }
1163 EXPORT_SYMBOL_GPL(clk_set_parent);
1164
1165 /**
1166 * __clk_init - initialize the data structures in a struct clk
1167 * @dev: device initializing this clk, placeholder for now
1168 * @clk: clk being initialized
1169 *
1170 * Initializes the lists in struct clk, queries the hardware for the
1171 * parent and rate and sets them both.
1172 */
1173 int __clk_init(struct device *dev, struct clk *clk)
1174 {
1175 int i, ret = 0;
1176 struct clk *orphan;
1177 struct hlist_node *tmp, *tmp2;
1178
1179 if (!clk)
1180 return -EINVAL;
1181
1182 mutex_lock(&prepare_lock);
1183
1184 /* check to see if a clock with this name is already registered */
1185 if (__clk_lookup(clk->name)) {
1186 pr_debug("%s: clk %s already initialized\n",
1187 __func__, clk->name);
1188 ret = -EEXIST;
1189 goto out;
1190 }
1191
1192 /* check that clk_ops are sane. See Documentation/clk.txt */
1193 if (clk->ops->set_rate &&
1194 !(clk->ops->round_rate && clk->ops->recalc_rate)) {
1195 pr_warning("%s: %s must implement .round_rate & .recalc_rate\n",
1196 __func__, clk->name);
1197 ret = -EINVAL;
1198 goto out;
1199 }
1200
1201 if (clk->ops->set_parent && !clk->ops->get_parent) {
1202 pr_warning("%s: %s must implement .get_parent & .set_parent\n",
1203 __func__, clk->name);
1204 ret = -EINVAL;
1205 goto out;
1206 }
1207
1208 /* throw a WARN if any entries in parent_names are NULL */
1209 for (i = 0; i < clk->num_parents; i++)
1210 WARN(!clk->parent_names[i],
1211 "%s: invalid NULL in %s's .parent_names\n",
1212 __func__, clk->name);
1213
1214 /*
1215 * Allocate an array of struct clk *'s to avoid unnecessary string
1216 * look-ups of clk's possible parents. This can fail for clocks passed
1217 * in to clk_init during early boot; thus any access to clk->parents[]
1218 * must always check for a NULL pointer and try to populate it if
1219 * necessary.
1220 *
1221 * If clk->parents is not NULL we skip this entire block. This allows
1222 * for clock drivers to statically initialize clk->parents.
1223 */
1224 if (clk->num_parents && !clk->parents) {
1225 clk->parents = kmalloc((sizeof(struct clk*) * clk->num_parents),
1226 GFP_KERNEL);
1227 /*
1228 * __clk_lookup returns NULL for parents that have not been
1229 * clk_init'd; thus any access to clk->parents[] must check
1230 * for a NULL pointer. We can always perform lazy lookups for
1231 * missing parents later on.
1232 */
1233 if (clk->parents)
1234 for (i = 0; i < clk->num_parents; i++)
1235 clk->parents[i] =
1236 __clk_lookup(clk->parent_names[i]);
1237 }
1238
1239 clk->parent = __clk_init_parent(clk);
1240
1241 /*
1242 * Populate clk->parent if parent has already been __clk_init'd. If
1243 * parent has not yet been __clk_init'd then place clk in the orphan
1244 * list. If clk has set the CLK_IS_ROOT flag then place it in the root
1245 * clk list.
1246 *
1247 * Every time a new clk is clk_init'd then we walk the list of orphan
1248 * clocks and re-parent any that are children of the clock currently
1249 * being clk_init'd.
1250 */
1251 if (clk->parent)
1252 hlist_add_head(&clk->child_node,
1253 &clk->parent->children);
1254 else if (clk->flags & CLK_IS_ROOT)
1255 hlist_add_head(&clk->child_node, &clk_root_list);
1256 else
1257 hlist_add_head(&clk->child_node, &clk_orphan_list);
1258
1259 /*
1260 * Set clk's rate. The preferred method is to use .recalc_rate. For
1261 * simple clocks and lazy developers the default fallback is to use the
1262 * parent's rate. If a clock doesn't have a parent (or is orphaned)
1263 * then rate is set to zero.
1264 */
1265 if (clk->ops->recalc_rate)
1266 clk->rate = clk->ops->recalc_rate(clk->hw,
1267 __clk_get_rate(clk->parent));
1268 else if (clk->parent)
1269 clk->rate = clk->parent->rate;
1270 else
1271 clk->rate = 0;
1272
1273 /*
1274 * walk the list of orphan clocks and reparent any that are children of
1275 * this clock
1276 */
1277 hlist_for_each_entry_safe(orphan, tmp, tmp2, &clk_orphan_list, child_node)
1278 for (i = 0; i < orphan->num_parents; i++)
1279 if (!strcmp(clk->name, orphan->parent_names[i])) {
1280 __clk_reparent(orphan, clk);
1281 break;
1282 }
1283
1284 /*
1285 * optional platform-specific magic
1286 *
1287 * The .init callback is not used by any of the basic clock types, but
1288 * exists for weird hardware that must perform initialization magic.
1289 * Please consider other ways of solving initialization problems before
1290 * using this callback, as it's use is discouraged.
1291 */
1292 if (clk->ops->init)
1293 clk->ops->init(clk->hw);
1294
1295 clk_debug_register(clk);
1296
1297 out:
1298 mutex_unlock(&prepare_lock);
1299
1300 return ret;
1301 }
1302
1303 /**
1304 * __clk_register - register a clock and return a cookie.
1305 *
1306 * Same as clk_register, except that the .clk field inside hw shall point to a
1307 * preallocated (generally statically allocated) struct clk. None of the fields
1308 * of the struct clk need to be initialized.
1309 *
1310 * The data pointed to by .init and .clk field shall NOT be marked as init
1311 * data.
1312 *
1313 * __clk_register is only exposed via clk-private.h and is intended for use with
1314 * very large numbers of clocks that need to be statically initialized. It is
1315 * a layering violation to include clk-private.h from any code which implements
1316 * a clock's .ops; as such any statically initialized clock data MUST be in a
1317 * separate C file from the logic that implements it's operations. Returns 0
1318 * on success, otherwise an error code.
1319 */
1320 struct clk *__clk_register(struct device *dev, struct clk_hw *hw)
1321 {
1322 int ret;
1323 struct clk *clk;
1324
1325 clk = hw->clk;
1326 clk->name = hw->init->name;
1327 clk->ops = hw->init->ops;
1328 clk->hw = hw;
1329 clk->flags = hw->init->flags;
1330 clk->parent_names = hw->init->parent_names;
1331 clk->num_parents = hw->init->num_parents;
1332
1333 ret = __clk_init(dev, clk);
1334 if (ret)
1335 return ERR_PTR(ret);
1336
1337 return clk;
1338 }
1339 EXPORT_SYMBOL_GPL(__clk_register);
1340
1341 /**
1342 * clk_register - allocate a new clock, register it and return an opaque cookie
1343 * @dev: device that is registering this clock
1344 * @hw: link to hardware-specific clock data
1345 *
1346 * clk_register is the primary interface for populating the clock tree with new
1347 * clock nodes. It returns a pointer to the newly allocated struct clk which
1348 * cannot be dereferenced by driver code but may be used in conjuction with the
1349 * rest of the clock API. In the event of an error clk_register will return an
1350 * error code; drivers must test for an error code after calling clk_register.
1351 */
1352 struct clk *clk_register(struct device *dev, struct clk_hw *hw)
1353 {
1354 int i, ret;
1355 struct clk *clk;
1356
1357 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
1358 if (!clk) {
1359 pr_err("%s: could not allocate clk\n", __func__);
1360 ret = -ENOMEM;
1361 goto fail_out;
1362 }
1363
1364 clk->name = kstrdup(hw->init->name, GFP_KERNEL);
1365 if (!clk->name) {
1366 pr_err("%s: could not allocate clk->name\n", __func__);
1367 ret = -ENOMEM;
1368 goto fail_name;
1369 }
1370 clk->ops = hw->init->ops;
1371 clk->hw = hw;
1372 clk->flags = hw->init->flags;
1373 clk->num_parents = hw->init->num_parents;
1374 hw->clk = clk;
1375
1376 /* allocate local copy in case parent_names is __initdata */
1377 clk->parent_names = kzalloc((sizeof(char*) * clk->num_parents),
1378 GFP_KERNEL);
1379
1380 if (!clk->parent_names) {
1381 pr_err("%s: could not allocate clk->parent_names\n", __func__);
1382 ret = -ENOMEM;
1383 goto fail_parent_names;
1384 }
1385
1386
1387 /* copy each string name in case parent_names is __initdata */
1388 for (i = 0; i < clk->num_parents; i++) {
1389 clk->parent_names[i] = kstrdup(hw->init->parent_names[i],
1390 GFP_KERNEL);
1391 if (!clk->parent_names[i]) {
1392 pr_err("%s: could not copy parent_names\n", __func__);
1393 ret = -ENOMEM;
1394 goto fail_parent_names_copy;
1395 }
1396 }
1397
1398 ret = __clk_init(dev, clk);
1399 if (!ret)
1400 return clk;
1401
1402 fail_parent_names_copy:
1403 while (--i >= 0)
1404 kfree(clk->parent_names[i]);
1405 kfree(clk->parent_names);
1406 fail_parent_names:
1407 kfree(clk->name);
1408 fail_name:
1409 kfree(clk);
1410 fail_out:
1411 return ERR_PTR(ret);
1412 }
1413 EXPORT_SYMBOL_GPL(clk_register);
1414
1415 /*** clk rate change notifiers ***/
1416
1417 /**
1418 * clk_notifier_register - add a clk rate change notifier
1419 * @clk: struct clk * to watch
1420 * @nb: struct notifier_block * with callback info
1421 *
1422 * Request notification when clk's rate changes. This uses an SRCU
1423 * notifier because we want it to block and notifier unregistrations are
1424 * uncommon. The callbacks associated with the notifier must not
1425 * re-enter into the clk framework by calling any top-level clk APIs;
1426 * this will cause a nested prepare_lock mutex.
1427 *
1428 * Pre-change notifier callbacks will be passed the current, pre-change
1429 * rate of the clk via struct clk_notifier_data.old_rate. The new,
1430 * post-change rate of the clk is passed via struct
1431 * clk_notifier_data.new_rate.
1432 *
1433 * Post-change notifiers will pass the now-current, post-change rate of
1434 * the clk in both struct clk_notifier_data.old_rate and struct
1435 * clk_notifier_data.new_rate.
1436 *
1437 * Abort-change notifiers are effectively the opposite of pre-change
1438 * notifiers: the original pre-change clk rate is passed in via struct
1439 * clk_notifier_data.new_rate and the failed post-change rate is passed
1440 * in via struct clk_notifier_data.old_rate.
1441 *
1442 * clk_notifier_register() must be called from non-atomic context.
1443 * Returns -EINVAL if called with null arguments, -ENOMEM upon
1444 * allocation failure; otherwise, passes along the return value of
1445 * srcu_notifier_chain_register().
1446 */
1447 int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
1448 {
1449 struct clk_notifier *cn;
1450 int ret = -ENOMEM;
1451
1452 if (!clk || !nb)
1453 return -EINVAL;
1454
1455 mutex_lock(&prepare_lock);
1456
1457 /* search the list of notifiers for this clk */
1458 list_for_each_entry(cn, &clk_notifier_list, node)
1459 if (cn->clk == clk)
1460 break;
1461
1462 /* if clk wasn't in the notifier list, allocate new clk_notifier */
1463 if (cn->clk != clk) {
1464 cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL);
1465 if (!cn)
1466 goto out;
1467
1468 cn->clk = clk;
1469 srcu_init_notifier_head(&cn->notifier_head);
1470
1471 list_add(&cn->node, &clk_notifier_list);
1472 }
1473
1474 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
1475
1476 clk->notifier_count++;
1477
1478 out:
1479 mutex_unlock(&prepare_lock);
1480
1481 return ret;
1482 }
1483 EXPORT_SYMBOL_GPL(clk_notifier_register);
1484
1485 /**
1486 * clk_notifier_unregister - remove a clk rate change notifier
1487 * @clk: struct clk *
1488 * @nb: struct notifier_block * with callback info
1489 *
1490 * Request no further notification for changes to 'clk' and frees memory
1491 * allocated in clk_notifier_register.
1492 *
1493 * Returns -EINVAL if called with null arguments; otherwise, passes
1494 * along the return value of srcu_notifier_chain_unregister().
1495 */
1496 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
1497 {
1498 struct clk_notifier *cn = NULL;
1499 int ret = -EINVAL;
1500
1501 if (!clk || !nb)
1502 return -EINVAL;
1503
1504 mutex_lock(&prepare_lock);
1505
1506 list_for_each_entry(cn, &clk_notifier_list, node)
1507 if (cn->clk == clk)
1508 break;
1509
1510 if (cn->clk == clk) {
1511 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
1512
1513 clk->notifier_count--;
1514
1515 /* XXX the notifier code should handle this better */
1516 if (!cn->notifier_head.head) {
1517 srcu_cleanup_notifier_head(&cn->notifier_head);
1518 kfree(cn);
1519 }
1520
1521 } else {
1522 ret = -ENOENT;
1523 }
1524
1525 mutex_unlock(&prepare_lock);
1526
1527 return ret;
1528 }
1529 EXPORT_SYMBOL_GPL(clk_notifier_unregister);