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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
20static DEFINE_SPINLOCK(enable_lock);
21static DEFINE_MUTEX(prepare_lock);
22
23static HLIST_HEAD(clk_root_list);
24static HLIST_HEAD(clk_orphan_list);
25static LIST_HEAD(clk_notifier_list);
26
27/*** debugfs support ***/
28
29#ifdef CONFIG_COMMON_CLK_DEBUG
30#include <linux/debugfs.h>
31
32static struct dentry *rootdir;
33static struct dentry *orphandir;
34static int inited = 0;
35
36/* caller must hold prepare_lock */
37static 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
81err_out:
82 debugfs_remove(clk->dentry);
83out:
84 return ret;
85}
86
87/* caller must hold prepare_lock */
88static 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;
106out:
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 */
121static 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
149out:
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 */
165static 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}
194late_initcall(clk_debug_init);
195#else
196static inline int clk_debug_register(struct clk *clk) { return 0; }
197#endif
198
199/* caller must hold prepare_lock */
200static void clk_disable_unused_subtree(struct clk *clk)
201{
202 struct clk *child;
203 struct hlist_node *tmp;
204 unsigned long flags;
205
206 if (!clk)
207 goto out;
208
209 hlist_for_each_entry(child, tmp, &clk->children, child_node)
210 clk_disable_unused_subtree(child);
211
212 spin_lock_irqsave(&enable_lock, flags);
213
214 if (clk->enable_count)
215 goto unlock_out;
216
217 if (clk->flags & CLK_IGNORE_UNUSED)
218 goto unlock_out;
219
220 if (__clk_is_enabled(clk) && clk->ops->disable)
221 clk->ops->disable(clk->hw);
222
223unlock_out:
224 spin_unlock_irqrestore(&enable_lock, flags);
225
226out:
227 return;
228}
229
230static int clk_disable_unused(void)
231{
232 struct clk *clk;
233 struct hlist_node *tmp;
234
235 mutex_lock(&prepare_lock);
236
237 hlist_for_each_entry(clk, tmp, &clk_root_list, child_node)
238 clk_disable_unused_subtree(clk);
239
240 hlist_for_each_entry(clk, tmp, &clk_orphan_list, child_node)
241 clk_disable_unused_subtree(clk);
242
243 mutex_unlock(&prepare_lock);
244
245 return 0;
246}
247late_initcall(clk_disable_unused);
248
249/*** helper functions ***/
250
251inline const char *__clk_get_name(struct clk *clk)
252{
253 return !clk ? NULL : clk->name;
254}
255
256inline struct clk_hw *__clk_get_hw(struct clk *clk)
257{
258 return !clk ? NULL : clk->hw;
259}
260
261inline u8 __clk_get_num_parents(struct clk *clk)
262{
263 return !clk ? -EINVAL : clk->num_parents;
264}
265
266inline struct clk *__clk_get_parent(struct clk *clk)
267{
268 return !clk ? NULL : clk->parent;
269}
270
271inline int __clk_get_enable_count(struct clk *clk)
272{
273 return !clk ? -EINVAL : clk->enable_count;
274}
275
276inline int __clk_get_prepare_count(struct clk *clk)
277{
278 return !clk ? -EINVAL : clk->prepare_count;
279}
280
281unsigned long __clk_get_rate(struct clk *clk)
282{
283 unsigned long ret;
284
285 if (!clk) {
286 ret = 0;
287 goto out;
288 }
289
290 ret = clk->rate;
291
292 if (clk->flags & CLK_IS_ROOT)
293 goto out;
294
295 if (!clk->parent)
296 ret = 0;
297
298out:
299 return ret;
300}
301
302inline unsigned long __clk_get_flags(struct clk *clk)
303{
304 return !clk ? -EINVAL : clk->flags;
305}
306
307int __clk_is_enabled(struct clk *clk)
308{
309 int ret;
310
311 if (!clk)
312 return -EINVAL;
313
314 /*
315 * .is_enabled is only mandatory for clocks that gate
316 * fall back to software usage counter if .is_enabled is missing
317 */
318 if (!clk->ops->is_enabled) {
319 ret = clk->enable_count ? 1 : 0;
320 goto out;
321 }
322
323 ret = clk->ops->is_enabled(clk->hw);
324out:
325 return ret;
326}
327
328static struct clk *__clk_lookup_subtree(const char *name, struct clk *clk)
329{
330 struct clk *child;
331 struct clk *ret;
332 struct hlist_node *tmp;
333
334 if (!strcmp(clk->name, name))
335 return clk;
336
337 hlist_for_each_entry(child, tmp, &clk->children, child_node) {
338 ret = __clk_lookup_subtree(name, child);
339 if (ret)
340 return ret;
341 }
342
343 return NULL;
344}
345
346struct clk *__clk_lookup(const char *name)
347{
348 struct clk *root_clk;
349 struct clk *ret;
350 struct hlist_node *tmp;
351
352 if (!name)
353 return NULL;
354
355 /* search the 'proper' clk tree first */
356 hlist_for_each_entry(root_clk, tmp, &clk_root_list, child_node) {
357 ret = __clk_lookup_subtree(name, root_clk);
358 if (ret)
359 return ret;
360 }
361
362 /* if not found, then search the orphan tree */
363 hlist_for_each_entry(root_clk, tmp, &clk_orphan_list, child_node) {
364 ret = __clk_lookup_subtree(name, root_clk);
365 if (ret)
366 return ret;
367 }
368
369 return NULL;
370}
371
372/*** clk api ***/
373
374void __clk_unprepare(struct clk *clk)
375{
376 if (!clk)
377 return;
378
379 if (WARN_ON(clk->prepare_count == 0))
380 return;
381
382 if (--clk->prepare_count > 0)
383 return;
384
385 WARN_ON(clk->enable_count > 0);
386
387 if (clk->ops->unprepare)
388 clk->ops->unprepare(clk->hw);
389
390 __clk_unprepare(clk->parent);
391}
392
393/**
394 * clk_unprepare - undo preparation of a clock source
395 * @clk: the clk being unprepare
396 *
397 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
398 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
399 * if the operation may sleep. One example is a clk which is accessed over
400 * I2c. In the complex case a clk gate operation may require a fast and a slow
401 * part. It is this reason that clk_unprepare and clk_disable are not mutually
402 * exclusive. In fact clk_disable must be called before clk_unprepare.
403 */
404void clk_unprepare(struct clk *clk)
405{
406 mutex_lock(&prepare_lock);
407 __clk_unprepare(clk);
408 mutex_unlock(&prepare_lock);
409}
410EXPORT_SYMBOL_GPL(clk_unprepare);
411
412int __clk_prepare(struct clk *clk)
413{
414 int ret = 0;
415
416 if (!clk)
417 return 0;
418
419 if (clk->prepare_count == 0) {
420 ret = __clk_prepare(clk->parent);
421 if (ret)
422 return ret;
423
424 if (clk->ops->prepare) {
425 ret = clk->ops->prepare(clk->hw);
426 if (ret) {
427 __clk_unprepare(clk->parent);
428 return ret;
429 }
430 }
431 }
432
433 clk->prepare_count++;
434
435 return 0;
436}
437
438/**
439 * clk_prepare - prepare a clock source
440 * @clk: the clk being prepared
441 *
442 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
443 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
444 * operation may sleep. One example is a clk which is accessed over I2c. In
445 * the complex case a clk ungate operation may require a fast and a slow part.
446 * It is this reason that clk_prepare and clk_enable are not mutually
447 * exclusive. In fact clk_prepare must be called before clk_enable.
448 * Returns 0 on success, -EERROR otherwise.
449 */
450int clk_prepare(struct clk *clk)
451{
452 int ret;
453
454 mutex_lock(&prepare_lock);
455 ret = __clk_prepare(clk);
456 mutex_unlock(&prepare_lock);
457
458 return ret;
459}
460EXPORT_SYMBOL_GPL(clk_prepare);
461
462static void __clk_disable(struct clk *clk)
463{
464 if (!clk)
465 return;
466
467 if (WARN_ON(clk->enable_count == 0))
468 return;
469
470 if (--clk->enable_count > 0)
471 return;
472
473 if (clk->ops->disable)
474 clk->ops->disable(clk->hw);
475
476 __clk_disable(clk->parent);
477}
478
479/**
480 * clk_disable - gate a clock
481 * @clk: the clk being gated
482 *
483 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
484 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
485 * clk if the operation is fast and will never sleep. One example is a
486 * SoC-internal clk which is controlled via simple register writes. In the
487 * complex case a clk gate operation may require a fast and a slow part. It is
488 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
489 * In fact clk_disable must be called before clk_unprepare.
490 */
491void clk_disable(struct clk *clk)
492{
493 unsigned long flags;
494
495 spin_lock_irqsave(&enable_lock, flags);
496 __clk_disable(clk);
497 spin_unlock_irqrestore(&enable_lock, flags);
498}
499EXPORT_SYMBOL_GPL(clk_disable);
500
501static int __clk_enable(struct clk *clk)
502{
503 int ret = 0;
504
505 if (!clk)
506 return 0;
507
508 if (WARN_ON(clk->prepare_count == 0))
509 return -ESHUTDOWN;
510
511 if (clk->enable_count == 0) {
512 ret = __clk_enable(clk->parent);
513
514 if (ret)
515 return ret;
516
517 if (clk->ops->enable) {
518 ret = clk->ops->enable(clk->hw);
519 if (ret) {
520 __clk_disable(clk->parent);
521 return ret;
522 }
523 }
524 }
525
526 clk->enable_count++;
527 return 0;
528}
529
530/**
531 * clk_enable - ungate a clock
532 * @clk: the clk being ungated
533 *
534 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
535 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
536 * if the operation will never sleep. One example is a SoC-internal clk which
537 * is controlled via simple register writes. In the complex case a clk ungate
538 * operation may require a fast and a slow part. It is this reason that
539 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
540 * must be called before clk_enable. Returns 0 on success, -EERROR
541 * otherwise.
542 */
543int clk_enable(struct clk *clk)
544{
545 unsigned long flags;
546 int ret;
547
548 spin_lock_irqsave(&enable_lock, flags);
549 ret = __clk_enable(clk);
550 spin_unlock_irqrestore(&enable_lock, flags);
551
552 return ret;
553}
554EXPORT_SYMBOL_GPL(clk_enable);
555
556/**
557 * clk_get_rate - return the rate of clk
558 * @clk: the clk whose rate is being returned
559 *
560 * Simply returns the cached rate of the clk. Does not query the hardware. If
561 * clk is NULL then returns 0.
562 */
563unsigned long clk_get_rate(struct clk *clk)
564{
565 unsigned long rate;
566
567 mutex_lock(&prepare_lock);
568 rate = __clk_get_rate(clk);
569 mutex_unlock(&prepare_lock);
570
571 return rate;
572}
573EXPORT_SYMBOL_GPL(clk_get_rate);
574
575/**
576 * __clk_round_rate - round the given rate for a clk
577 * @clk: round the rate of this clock
578 *
579 * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate
580 */
581unsigned long __clk_round_rate(struct clk *clk, unsigned long rate)
582{
583 unsigned long parent_rate = 0;
584
585 if (!clk)
586 return -EINVAL;
587
588 if (!clk->ops->round_rate) {
589 if (clk->flags & CLK_SET_RATE_PARENT)
590 return __clk_round_rate(clk->parent, rate);
591 else
592 return clk->rate;
593 }
594
595 if (clk->parent)
596 parent_rate = clk->parent->rate;
597
598 return clk->ops->round_rate(clk->hw, rate, &parent_rate);
599}
600
601/**
602 * clk_round_rate - round the given rate for a clk
603 * @clk: the clk for which we are rounding a rate
604 * @rate: the rate which is to be rounded
605 *
606 * Takes in a rate as input and rounds it to a rate that the clk can actually
607 * use which is then returned. If clk doesn't support round_rate operation
608 * then the parent rate is returned.
609 */
610long clk_round_rate(struct clk *clk, unsigned long rate)
611{
612 unsigned long ret;
613
614 mutex_lock(&prepare_lock);
615 ret = __clk_round_rate(clk, rate);
616 mutex_unlock(&prepare_lock);
617
618 return ret;
619}
620EXPORT_SYMBOL_GPL(clk_round_rate);
621
622/**
623 * __clk_notify - call clk notifier chain
624 * @clk: struct clk * that is changing rate
625 * @msg: clk notifier type (see include/linux/clk.h)
626 * @old_rate: old clk rate
627 * @new_rate: new clk rate
628 *
629 * Triggers a notifier call chain on the clk rate-change notification
630 * for 'clk'. Passes a pointer to the struct clk and the previous
631 * and current rates to the notifier callback. Intended to be called by
632 * internal clock code only. Returns NOTIFY_DONE from the last driver
633 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
634 * a driver returns that.
635 */
636static int __clk_notify(struct clk *clk, unsigned long msg,
637 unsigned long old_rate, unsigned long new_rate)
638{
639 struct clk_notifier *cn;
640 struct clk_notifier_data cnd;
641 int ret = NOTIFY_DONE;
642
643 cnd.clk = clk;
644 cnd.old_rate = old_rate;
645 cnd.new_rate = new_rate;
646
647 list_for_each_entry(cn, &clk_notifier_list, node) {
648 if (cn->clk == clk) {
649 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
650 &cnd);
651 break;
652 }
653 }
654
655 return ret;
656}
657
658/**
659 * __clk_recalc_rates
660 * @clk: first clk in the subtree
661 * @msg: notification type (see include/linux/clk.h)
662 *
663 * Walks the subtree of clks starting with clk and recalculates rates as it
664 * goes. Note that if a clk does not implement the .recalc_rate callback then
665 * it is assumed that the clock will take on the rate of it's parent.
666 *
667 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
668 * if necessary.
669 *
670 * Caller must hold prepare_lock.
671 */
672static void __clk_recalc_rates(struct clk *clk, unsigned long msg)
673{
674 unsigned long old_rate;
675 unsigned long parent_rate = 0;
676 struct hlist_node *tmp;
677 struct clk *child;
678
679 old_rate = clk->rate;
680
681 if (clk->parent)
682 parent_rate = clk->parent->rate;
683
684 if (clk->ops->recalc_rate)
685 clk->rate = clk->ops->recalc_rate(clk->hw, parent_rate);
686 else
687 clk->rate = parent_rate;
688
689 /*
690 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
691 * & ABORT_RATE_CHANGE notifiers
692 */
693 if (clk->notifier_count && msg)
694 __clk_notify(clk, msg, old_rate, clk->rate);
695
696 hlist_for_each_entry(child, tmp, &clk->children, child_node)
697 __clk_recalc_rates(child, msg);
698}
699
700/**
701 * __clk_speculate_rates
702 * @clk: first clk in the subtree
703 * @parent_rate: the "future" rate of clk's parent
704 *
705 * Walks the subtree of clks starting with clk, speculating rates as it
706 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
707 *
708 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
709 * pre-rate change notifications and returns early if no clks in the
710 * subtree have subscribed to the notifications. Note that if a clk does not
711 * implement the .recalc_rate callback then it is assumed that the clock will
712 * take on the rate of it's parent.
713 *
714 * Caller must hold prepare_lock.
715 */
716static int __clk_speculate_rates(struct clk *clk, unsigned long parent_rate)
717{
718 struct hlist_node *tmp;
719 struct clk *child;
720 unsigned long new_rate;
721 int ret = NOTIFY_DONE;
722
723 if (clk->ops->recalc_rate)
724 new_rate = clk->ops->recalc_rate(clk->hw, parent_rate);
725 else
726 new_rate = parent_rate;
727
728 /* abort the rate change if a driver returns NOTIFY_BAD */
729 if (clk->notifier_count)
730 ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate);
731
732 if (ret == NOTIFY_BAD)
733 goto out;
734
735 hlist_for_each_entry(child, tmp, &clk->children, child_node) {
736 ret = __clk_speculate_rates(child, new_rate);
737 if (ret == NOTIFY_BAD)
738 break;
739 }
740
741out:
742 return ret;
743}
744
745static void clk_calc_subtree(struct clk *clk, unsigned long new_rate)
746{
747 struct clk *child;
748 struct hlist_node *tmp;
749
750 clk->new_rate = new_rate;
751
752 hlist_for_each_entry(child, tmp, &clk->children, child_node) {
753 if (child->ops->recalc_rate)
754 child->new_rate = child->ops->recalc_rate(child->hw, new_rate);
755 else
756 child->new_rate = new_rate;
757 clk_calc_subtree(child, child->new_rate);
758 }
759}
760
761/*
762 * calculate the new rates returning the topmost clock that has to be
763 * changed.
764 */
765static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate)
766{
767 struct clk *top = clk;
768 unsigned long best_parent_rate = 0;
769 unsigned long new_rate;
770
771 /* sanity */
772 if (IS_ERR_OR_NULL(clk))
773 return NULL;
774
775 /* save parent rate, if it exists */
776 if (clk->parent)
777 best_parent_rate = clk->parent->rate;
778
779 /* never propagate up to the parent */
780 if (!(clk->flags & CLK_SET_RATE_PARENT)) {
781 if (!clk->ops->round_rate) {
782 clk->new_rate = clk->rate;
783 return NULL;
784 }
785 new_rate = clk->ops->round_rate(clk->hw, rate, &best_parent_rate);
786 goto out;
787 }
788
789 /* need clk->parent from here on out */
790 if (!clk->parent) {
791 pr_debug("%s: %s has NULL parent\n", __func__, clk->name);
792 return NULL;
793 }
794
795 if (!clk->ops->round_rate) {
796 top = clk_calc_new_rates(clk->parent, rate);
797 new_rate = clk->parent->new_rate;
798
799 goto out;
800 }
801
802 new_rate = clk->ops->round_rate(clk->hw, rate, &best_parent_rate);
803
804 if (best_parent_rate != clk->parent->rate) {
805 top = clk_calc_new_rates(clk->parent, best_parent_rate);
806
807 goto out;
808 }
809
810out:
811 clk_calc_subtree(clk, new_rate);
812
813 return top;
814}
815
816/*
817 * Notify about rate changes in a subtree. Always walk down the whole tree
818 * so that in case of an error we can walk down the whole tree again and
819 * abort the change.
820 */
821static struct clk *clk_propagate_rate_change(struct clk *clk, unsigned long event)
822{
823 struct hlist_node *tmp;
824 struct clk *child, *fail_clk = NULL;
825 int ret = NOTIFY_DONE;
826
827 if (clk->rate == clk->new_rate)
828 return 0;
829
830 if (clk->notifier_count) {
831 ret = __clk_notify(clk, event, clk->rate, clk->new_rate);
832 if (ret == NOTIFY_BAD)
833 fail_clk = clk;
834 }
835
836 hlist_for_each_entry(child, tmp, &clk->children, child_node) {
837 clk = clk_propagate_rate_change(child, event);
838 if (clk)
839 fail_clk = clk;
840 }
841
842 return fail_clk;
843}
844
845/*
846 * walk down a subtree and set the new rates notifying the rate
847 * change on the way
848 */
849static void clk_change_rate(struct clk *clk)
850{
851 struct clk *child;
852 unsigned long old_rate;
853 unsigned long best_parent_rate = 0;
854 struct hlist_node *tmp;
855
856 old_rate = clk->rate;
857
858 if (clk->parent)
859 best_parent_rate = clk->parent->rate;
860
861 if (clk->ops->set_rate)
862 clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate);
863
864 if (clk->ops->recalc_rate)
865 clk->rate = clk->ops->recalc_rate(clk->hw, best_parent_rate);
866 else
867 clk->rate = best_parent_rate;
868
869 if (clk->notifier_count && old_rate != clk->rate)
870 __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate);
871
872 hlist_for_each_entry(child, tmp, &clk->children, child_node)
873 clk_change_rate(child);
874}
875
876/**
877 * clk_set_rate - specify a new rate for clk
878 * @clk: the clk whose rate is being changed
879 * @rate: the new rate for clk
880 *
881 * In the simplest case clk_set_rate will only adjust the rate of clk.
882 *
883 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
884 * propagate up to clk's parent; whether or not this happens depends on the
885 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
886 * after calling .round_rate then upstream parent propagation is ignored. If
887 * *parent_rate comes back with a new rate for clk's parent then we propagate
888 * up to clk's parent and set it's rate. Upward propagation will continue
889 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
890 * .round_rate stops requesting changes to clk's parent_rate.
891 *
892 * Rate changes are accomplished via tree traversal that also recalculates the
893 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
894 *
895 * Returns 0 on success, -EERROR otherwise.
896 */
897int clk_set_rate(struct clk *clk, unsigned long rate)
898{
899 struct clk *top, *fail_clk;
900 int ret = 0;
901
902 /* prevent racing with updates to the clock topology */
903 mutex_lock(&prepare_lock);
904
905 /* bail early if nothing to do */
906 if (rate == clk->rate)
907 goto out;
908
909 if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count) {
910 ret = -EBUSY;
911 goto out;
912 }
913
914 /* calculate new rates and get the topmost changed clock */
915 top = clk_calc_new_rates(clk, rate);
916 if (!top) {
917 ret = -EINVAL;
918 goto out;
919 }
920
921 /* notify that we are about to change rates */
922 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
923 if (fail_clk) {
924 pr_warn("%s: failed to set %s rate\n", __func__,
925 fail_clk->name);
926 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
927 ret = -EBUSY;
928 goto out;
929 }
930
931 /* change the rates */
932 clk_change_rate(top);
933
934 mutex_unlock(&prepare_lock);
935
936 return 0;
937out:
938 mutex_unlock(&prepare_lock);
939
940 return ret;
941}
942EXPORT_SYMBOL_GPL(clk_set_rate);
943
944/**
945 * clk_get_parent - return the parent of a clk
946 * @clk: the clk whose parent gets returned
947 *
948 * Simply returns clk->parent. Returns NULL if clk is NULL.
949 */
950struct clk *clk_get_parent(struct clk *clk)
951{
952 struct clk *parent;
953
954 mutex_lock(&prepare_lock);
955 parent = __clk_get_parent(clk);
956 mutex_unlock(&prepare_lock);
957
958 return parent;
959}
960EXPORT_SYMBOL_GPL(clk_get_parent);
961
962/*
963 * .get_parent is mandatory for clocks with multiple possible parents. It is
964 * optional for single-parent clocks. Always call .get_parent if it is
965 * available and WARN if it is missing for multi-parent clocks.
966 *
967 * For single-parent clocks without .get_parent, first check to see if the
968 * .parents array exists, and if so use it to avoid an expensive tree
969 * traversal. If .parents does not exist then walk the tree with __clk_lookup.
970 */
971static struct clk *__clk_init_parent(struct clk *clk)
972{
973 struct clk *ret = NULL;
974 u8 index;
975
976 /* handle the trivial cases */
977
978 if (!clk->num_parents)
979 goto out;
980
981 if (clk->num_parents == 1) {
982 if (IS_ERR_OR_NULL(clk->parent))
983 ret = clk->parent = __clk_lookup(clk->parent_names[0]);
984 ret = clk->parent;
985 goto out;
986 }
987
988 if (!clk->ops->get_parent) {
989 WARN(!clk->ops->get_parent,
990 "%s: multi-parent clocks must implement .get_parent\n",
991 __func__);
992 goto out;
993 };
994
995 /*
996 * Do our best to cache parent clocks in clk->parents. This prevents
997 * unnecessary and expensive calls to __clk_lookup. We don't set
998 * clk->parent here; that is done by the calling function
999 */
1000
1001 index = clk->ops->get_parent(clk->hw);
1002
1003 if (!clk->parents)
1004 clk->parents =
1005 kzalloc((sizeof(struct clk*) * clk->num_parents),
1006 GFP_KERNEL);
1007
1008 if (!clk->parents)
1009 ret = __clk_lookup(clk->parent_names[index]);
1010 else if (!clk->parents[index])
1011 ret = clk->parents[index] =
1012 __clk_lookup(clk->parent_names[index]);
1013 else
1014 ret = clk->parents[index];
1015
1016out:
1017 return ret;
1018}
1019
1020void __clk_reparent(struct clk *clk, struct clk *new_parent)
1021{
1022#ifdef CONFIG_COMMON_CLK_DEBUG
1023 struct dentry *d;
1024 struct dentry *new_parent_d;
1025#endif
1026
1027 if (!clk || !new_parent)
1028 return;
1029
1030 hlist_del(&clk->child_node);
1031
1032 if (new_parent)
1033 hlist_add_head(&clk->child_node, &new_parent->children);
1034 else
1035 hlist_add_head(&clk->child_node, &clk_orphan_list);
1036
1037#ifdef CONFIG_COMMON_CLK_DEBUG
1038 if (!inited)
1039 goto out;
1040
1041 if (new_parent)
1042 new_parent_d = new_parent->dentry;
1043 else
1044 new_parent_d = orphandir;
1045
1046 d = debugfs_rename(clk->dentry->d_parent, clk->dentry,
1047 new_parent_d, clk->name);
1048 if (d)
1049 clk->dentry = d;
1050 else
1051 pr_debug("%s: failed to rename debugfs entry for %s\n",
1052 __func__, clk->name);
1053out:
1054#endif
1055
1056 clk->parent = new_parent;
1057
1058 __clk_recalc_rates(clk, POST_RATE_CHANGE);
1059}
1060
1061static int __clk_set_parent(struct clk *clk, struct clk *parent)
1062{
1063 struct clk *old_parent;
1064 unsigned long flags;
1065 int ret = -EINVAL;
1066 u8 i;
1067
1068 old_parent = clk->parent;
1069
1070 if (!clk->parents)
1071 clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents),
1072 GFP_KERNEL);
1073
1074 /*
1075 * find index of new parent clock using cached parent ptrs,
1076 * or if not yet cached, use string name comparison and cache
1077 * them now to avoid future calls to __clk_lookup.
1078 */
1079 for (i = 0; i < clk->num_parents; i++) {
1080 if (clk->parents && clk->parents[i] == parent)
1081 break;
1082 else if (!strcmp(clk->parent_names[i], parent->name)) {
1083 if (clk->parents)
1084 clk->parents[i] = __clk_lookup(parent->name);
1085 break;
1086 }
1087 }
1088
1089 if (i == clk->num_parents) {
1090 pr_debug("%s: clock %s is not a possible parent of clock %s\n",
1091 __func__, parent->name, clk->name);
1092 goto out;
1093 }
1094
1095 /* migrate prepare and enable */
1096 if (clk->prepare_count)
1097 __clk_prepare(parent);
1098
1099 /* FIXME replace with clk_is_enabled(clk) someday */
1100 spin_lock_irqsave(&enable_lock, flags);
1101 if (clk->enable_count)
1102 __clk_enable(parent);
1103 spin_unlock_irqrestore(&enable_lock, flags);
1104
1105 /* change clock input source */
1106 ret = clk->ops->set_parent(clk->hw, i);
1107
1108 /* clean up old prepare and enable */
1109 spin_lock_irqsave(&enable_lock, flags);
1110 if (clk->enable_count)
1111 __clk_disable(old_parent);
1112 spin_unlock_irqrestore(&enable_lock, flags);
1113
1114 if (clk->prepare_count)
1115 __clk_unprepare(old_parent);
1116
1117out:
1118 return ret;
1119}
1120
1121/**
1122 * clk_set_parent - switch the parent of a mux clk
1123 * @clk: the mux clk whose input we are switching
1124 * @parent: the new input to clk
1125 *
1126 * Re-parent clk to use parent as it's new input source. If clk has the
1127 * CLK_SET_PARENT_GATE flag set then clk must be gated for this
1128 * operation to succeed. After successfully changing clk's parent
1129 * clk_set_parent will update the clk topology, sysfs topology and
1130 * propagate rate recalculation via __clk_recalc_rates. Returns 0 on
1131 * success, -EERROR otherwise.
1132 */
1133int clk_set_parent(struct clk *clk, struct clk *parent)
1134{
1135 int ret = 0;
1136
1137 if (!clk || !clk->ops)
1138 return -EINVAL;
1139
1140 if (!clk->ops->set_parent)
1141 return -ENOSYS;
1142
1143 /* prevent racing with updates to the clock topology */
1144 mutex_lock(&prepare_lock);
1145
1146 if (clk->parent == parent)
1147 goto out;
1148
1149 /* propagate PRE_RATE_CHANGE notifications */
1150 if (clk->notifier_count)
1151 ret = __clk_speculate_rates(clk, parent->rate);
1152
1153 /* abort if a driver objects */
1154 if (ret == NOTIFY_STOP)
1155 goto out;
1156
1157 /* only re-parent if the clock is not in use */
1158 if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count)
1159 ret = -EBUSY;
1160 else
1161 ret = __clk_set_parent(clk, parent);
1162
1163 /* propagate ABORT_RATE_CHANGE if .set_parent failed */
1164 if (ret) {
1165 __clk_recalc_rates(clk, ABORT_RATE_CHANGE);
1166 goto out;
1167 }
1168
1169 /* propagate rate recalculation downstream */
1170 __clk_reparent(clk, parent);
1171
1172out:
1173 mutex_unlock(&prepare_lock);
1174
1175 return ret;
1176}
1177EXPORT_SYMBOL_GPL(clk_set_parent);
1178
1179/**
1180 * __clk_init - initialize the data structures in a struct clk
1181 * @dev: device initializing this clk, placeholder for now
1182 * @clk: clk being initialized
1183 *
1184 * Initializes the lists in struct clk, queries the hardware for the
1185 * parent and rate and sets them both.
1186 */
1187int __clk_init(struct device *dev, struct clk *clk)
1188{
1189 int i, ret = 0;
1190 struct clk *orphan;
1191 struct hlist_node *tmp, *tmp2;
1192
1193 if (!clk)
1194 return -EINVAL;
1195
1196 mutex_lock(&prepare_lock);
1197
1198 /* check to see if a clock with this name is already registered */
1199 if (__clk_lookup(clk->name)) {
1200 pr_debug("%s: clk %s already initialized\n",
1201 __func__, clk->name);
1202 ret = -EEXIST;
1203 goto out;
1204 }
1205
1206 /* check that clk_ops are sane. See Documentation/clk.txt */
1207 if (clk->ops->set_rate &&
1208 !(clk->ops->round_rate && clk->ops->recalc_rate)) {
1209 pr_warning("%s: %s must implement .round_rate & .recalc_rate\n",
1210 __func__, clk->name);
1211 ret = -EINVAL;
1212 goto out;
1213 }
1214
1215 if (clk->ops->set_parent && !clk->ops->get_parent) {
1216 pr_warning("%s: %s must implement .get_parent & .set_parent\n",
1217 __func__, clk->name);
1218 ret = -EINVAL;
1219 goto out;
1220 }
1221
1222 /* throw a WARN if any entries in parent_names are NULL */
1223 for (i = 0; i < clk->num_parents; i++)
1224 WARN(!clk->parent_names[i],
1225 "%s: invalid NULL in %s's .parent_names\n",
1226 __func__, clk->name);
1227
1228 /*
1229 * Allocate an array of struct clk *'s to avoid unnecessary string
1230 * look-ups of clk's possible parents. This can fail for clocks passed
1231 * in to clk_init during early boot; thus any access to clk->parents[]
1232 * must always check for a NULL pointer and try to populate it if
1233 * necessary.
1234 *
1235 * If clk->parents is not NULL we skip this entire block. This allows
1236 * for clock drivers to statically initialize clk->parents.
1237 */
1238 if (clk->num_parents && !clk->parents) {
1239 clk->parents = kmalloc((sizeof(struct clk*) * clk->num_parents),
1240 GFP_KERNEL);
1241 /*
1242 * __clk_lookup returns NULL for parents that have not been
1243 * clk_init'd; thus any access to clk->parents[] must check
1244 * for a NULL pointer. We can always perform lazy lookups for
1245 * missing parents later on.
1246 */
1247 if (clk->parents)
1248 for (i = 0; i < clk->num_parents; i++)
1249 clk->parents[i] =
1250 __clk_lookup(clk->parent_names[i]);
1251 }
1252
1253 clk->parent = __clk_init_parent(clk);
1254
1255 /*
1256 * Populate clk->parent if parent has already been __clk_init'd. If
1257 * parent has not yet been __clk_init'd then place clk in the orphan
1258 * list. If clk has set the CLK_IS_ROOT flag then place it in the root
1259 * clk list.
1260 *
1261 * Every time a new clk is clk_init'd then we walk the list of orphan
1262 * clocks and re-parent any that are children of the clock currently
1263 * being clk_init'd.
1264 */
1265 if (clk->parent)
1266 hlist_add_head(&clk->child_node,
1267 &clk->parent->children);
1268 else if (clk->flags & CLK_IS_ROOT)
1269 hlist_add_head(&clk->child_node, &clk_root_list);
1270 else
1271 hlist_add_head(&clk->child_node, &clk_orphan_list);
1272
1273 /*
1274 * Set clk's rate. The preferred method is to use .recalc_rate. For
1275 * simple clocks and lazy developers the default fallback is to use the
1276 * parent's rate. If a clock doesn't have a parent (or is orphaned)
1277 * then rate is set to zero.
1278 */
1279 if (clk->ops->recalc_rate)
1280 clk->rate = clk->ops->recalc_rate(clk->hw,
1281 __clk_get_rate(clk->parent));
1282 else if (clk->parent)
1283 clk->rate = clk->parent->rate;
1284 else
1285 clk->rate = 0;
1286
1287 /*
1288 * walk the list of orphan clocks and reparent any that are children of
1289 * this clock
1290 */
1291 hlist_for_each_entry_safe(orphan, tmp, tmp2, &clk_orphan_list, child_node)
1292 for (i = 0; i < orphan->num_parents; i++)
1293 if (!strcmp(clk->name, orphan->parent_names[i])) {
1294 __clk_reparent(orphan, clk);
1295 break;
1296 }
1297
1298 /*
1299 * optional platform-specific magic
1300 *
1301 * The .init callback is not used by any of the basic clock types, but
1302 * exists for weird hardware that must perform initialization magic.
1303 * Please consider other ways of solving initialization problems before
1304 * using this callback, as it's use is discouraged.
1305 */
1306 if (clk->ops->init)
1307 clk->ops->init(clk->hw);
1308
1309 clk_debug_register(clk);
1310
1311out:
1312 mutex_unlock(&prepare_lock);
1313
1314 return ret;
1315}
1316
1317/**
1318 * __clk_register - register a clock and return a cookie.
1319 *
1320 * Same as clk_register, except that the .clk field inside hw shall point to a
1321 * preallocated (generally statically allocated) struct clk. None of the fields
1322 * of the struct clk need to be initialized.
1323 *
1324 * The data pointed to by .init and .clk field shall NOT be marked as init
1325 * data.
1326 *
1327 * __clk_register is only exposed via clk-private.h and is intended for use with
1328 * very large numbers of clocks that need to be statically initialized. It is
1329 * a layering violation to include clk-private.h from any code which implements
1330 * a clock's .ops; as such any statically initialized clock data MUST be in a
1331 * separate C file from the logic that implements it's operations. Returns 0
1332 * on success, otherwise an error code.
1333 */
1334struct clk *__clk_register(struct device *dev, struct clk_hw *hw)
1335{
1336 int ret;
1337 struct clk *clk;
1338
1339 clk = hw->clk;
1340 clk->name = hw->init->name;
1341 clk->ops = hw->init->ops;
1342 clk->hw = hw;
1343 clk->flags = hw->init->flags;
1344 clk->parent_names = hw->init->parent_names;
1345 clk->num_parents = hw->init->num_parents;
1346
1347 ret = __clk_init(dev, clk);
1348 if (ret)
1349 return ERR_PTR(ret);
1350
1351 return clk;
1352}
1353EXPORT_SYMBOL_GPL(__clk_register);
1354
1355/**
1356 * clk_register - allocate a new clock, register it and return an opaque cookie
1357 * @dev: device that is registering this clock
1358 * @hw: link to hardware-specific clock data
1359 *
1360 * clk_register is the primary interface for populating the clock tree with new
1361 * clock nodes. It returns a pointer to the newly allocated struct clk which
1362 * cannot be dereferenced by driver code but may be used in conjuction with the
1363 * rest of the clock API. In the event of an error clk_register will return an
1364 * error code; drivers must test for an error code after calling clk_register.
1365 */
1366struct clk *clk_register(struct device *dev, struct clk_hw *hw)
1367{
1368 int i, ret;
1369 struct clk *clk;
1370
1371 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
1372 if (!clk) {
1373 pr_err("%s: could not allocate clk\n", __func__);
1374 ret = -ENOMEM;
1375 goto fail_out;
1376 }
1377
1378 clk->name = kstrdup(hw->init->name, GFP_KERNEL);
1379 if (!clk->name) {
1380 pr_err("%s: could not allocate clk->name\n", __func__);
1381 ret = -ENOMEM;
1382 goto fail_name;
1383 }
1384 clk->ops = hw->init->ops;
1385 clk->hw = hw;
1386 clk->flags = hw->init->flags;
1387 clk->num_parents = hw->init->num_parents;
1388 hw->clk = clk;
1389
1390 /* allocate local copy in case parent_names is __initdata */
1391 clk->parent_names = kzalloc((sizeof(char*) * clk->num_parents),
1392 GFP_KERNEL);
1393
1394 if (!clk->parent_names) {
1395 pr_err("%s: could not allocate clk->parent_names\n", __func__);
1396 ret = -ENOMEM;
1397 goto fail_parent_names;
1398 }
1399
1400
1401 /* copy each string name in case parent_names is __initdata */
1402 for (i = 0; i < clk->num_parents; i++) {
1403 clk->parent_names[i] = kstrdup(hw->init->parent_names[i],
1404 GFP_KERNEL);
1405 if (!clk->parent_names[i]) {
1406 pr_err("%s: could not copy parent_names\n", __func__);
1407 ret = -ENOMEM;
1408 goto fail_parent_names_copy;
1409 }
1410 }
1411
1412 ret = __clk_init(dev, clk);
1413 if (!ret)
1414 return clk;
1415
1416fail_parent_names_copy:
1417 while (--i >= 0)
1418 kfree(clk->parent_names[i]);
1419 kfree(clk->parent_names);
1420fail_parent_names:
1421 kfree(clk->name);
1422fail_name:
1423 kfree(clk);
1424fail_out:
1425 return ERR_PTR(ret);
1426}
1427EXPORT_SYMBOL_GPL(clk_register);
1428
1429/**
1430 * clk_unregister - unregister a currently registered clock
1431 * @clk: clock to unregister
1432 *
1433 * Currently unimplemented.
1434 */
1435void clk_unregister(struct clk *clk) {}
1436EXPORT_SYMBOL_GPL(clk_unregister);
1437
1438/*** clk rate change notifiers ***/
1439
1440/**
1441 * clk_notifier_register - add a clk rate change notifier
1442 * @clk: struct clk * to watch
1443 * @nb: struct notifier_block * with callback info
1444 *
1445 * Request notification when clk's rate changes. This uses an SRCU
1446 * notifier because we want it to block and notifier unregistrations are
1447 * uncommon. The callbacks associated with the notifier must not
1448 * re-enter into the clk framework by calling any top-level clk APIs;
1449 * this will cause a nested prepare_lock mutex.
1450 *
1451 * Pre-change notifier callbacks will be passed the current, pre-change
1452 * rate of the clk via struct clk_notifier_data.old_rate. The new,
1453 * post-change rate of the clk is passed via struct
1454 * clk_notifier_data.new_rate.
1455 *
1456 * Post-change notifiers will pass the now-current, post-change rate of
1457 * the clk in both struct clk_notifier_data.old_rate and struct
1458 * clk_notifier_data.new_rate.
1459 *
1460 * Abort-change notifiers are effectively the opposite of pre-change
1461 * notifiers: the original pre-change clk rate is passed in via struct
1462 * clk_notifier_data.new_rate and the failed post-change rate is passed
1463 * in via struct clk_notifier_data.old_rate.
1464 *
1465 * clk_notifier_register() must be called from non-atomic context.
1466 * Returns -EINVAL if called with null arguments, -ENOMEM upon
1467 * allocation failure; otherwise, passes along the return value of
1468 * srcu_notifier_chain_register().
1469 */
1470int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
1471{
1472 struct clk_notifier *cn;
1473 int ret = -ENOMEM;
1474
1475 if (!clk || !nb)
1476 return -EINVAL;
1477
1478 mutex_lock(&prepare_lock);
1479
1480 /* search the list of notifiers for this clk */
1481 list_for_each_entry(cn, &clk_notifier_list, node)
1482 if (cn->clk == clk)
1483 break;
1484
1485 /* if clk wasn't in the notifier list, allocate new clk_notifier */
1486 if (cn->clk != clk) {
1487 cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL);
1488 if (!cn)
1489 goto out;
1490
1491 cn->clk = clk;
1492 srcu_init_notifier_head(&cn->notifier_head);
1493
1494 list_add(&cn->node, &clk_notifier_list);
1495 }
1496
1497 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
1498
1499 clk->notifier_count++;
1500
1501out:
1502 mutex_unlock(&prepare_lock);
1503
1504 return ret;
1505}
1506EXPORT_SYMBOL_GPL(clk_notifier_register);
1507
1508/**
1509 * clk_notifier_unregister - remove a clk rate change notifier
1510 * @clk: struct clk *
1511 * @nb: struct notifier_block * with callback info
1512 *
1513 * Request no further notification for changes to 'clk' and frees memory
1514 * allocated in clk_notifier_register.
1515 *
1516 * Returns -EINVAL if called with null arguments; otherwise, passes
1517 * along the return value of srcu_notifier_chain_unregister().
1518 */
1519int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
1520{
1521 struct clk_notifier *cn = NULL;
1522 int ret = -EINVAL;
1523
1524 if (!clk || !nb)
1525 return -EINVAL;
1526
1527 mutex_lock(&prepare_lock);
1528
1529 list_for_each_entry(cn, &clk_notifier_list, node)
1530 if (cn->clk == clk)
1531 break;
1532
1533 if (cn->clk == clk) {
1534 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
1535
1536 clk->notifier_count--;
1537
1538 /* XXX the notifier code should handle this better */
1539 if (!cn->notifier_head.head) {
1540 srcu_cleanup_notifier_head(&cn->notifier_head);
1541 kfree(cn);
1542 }
1543
1544 } else {
1545 ret = -ENOENT;
1546 }
1547
1548 mutex_unlock(&prepare_lock);
1549
1550 return ret;
1551}
1552EXPORT_SYMBOL_GPL(clk_notifier_unregister);
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.h>
13#include <linux/clk-provider.h>
14#include <linux/clk/clk-conf.h>
15#include <linux/module.h>
16#include <linux/mutex.h>
17#include <linux/spinlock.h>
18#include <linux/err.h>
19#include <linux/list.h>
20#include <linux/slab.h>
21#include <linux/of.h>
22#include <linux/device.h>
23#include <linux/init.h>
24#include <linux/sched.h>
25#include <linux/clkdev.h>
26
27#include "clk.h"
28
29static DEFINE_SPINLOCK(enable_lock);
30static DEFINE_MUTEX(prepare_lock);
31
32static struct task_struct *prepare_owner;
33static struct task_struct *enable_owner;
34
35static int prepare_refcnt;
36static int enable_refcnt;
37
38static HLIST_HEAD(clk_root_list);
39static HLIST_HEAD(clk_orphan_list);
40static LIST_HEAD(clk_notifier_list);
41
42/*** private data structures ***/
43
44struct clk_core {
45 const char *name;
46 const struct clk_ops *ops;
47 struct clk_hw *hw;
48 struct module *owner;
49 struct clk_core *parent;
50 const char **parent_names;
51 struct clk_core **parents;
52 u8 num_parents;
53 u8 new_parent_index;
54 unsigned long rate;
55 unsigned long req_rate;
56 unsigned long new_rate;
57 struct clk_core *new_parent;
58 struct clk_core *new_child;
59 unsigned long flags;
60 bool orphan;
61 unsigned int enable_count;
62 unsigned int prepare_count;
63 unsigned long min_rate;
64 unsigned long max_rate;
65 unsigned long accuracy;
66 int phase;
67 struct hlist_head children;
68 struct hlist_node child_node;
69 struct hlist_head clks;
70 unsigned int notifier_count;
71#ifdef CONFIG_DEBUG_FS
72 struct dentry *dentry;
73 struct hlist_node debug_node;
74#endif
75 struct kref ref;
76};
77
78#define CREATE_TRACE_POINTS
79#include <trace/events/clk.h>
80
81struct clk {
82 struct clk_core *core;
83 const char *dev_id;
84 const char *con_id;
85 unsigned long min_rate;
86 unsigned long max_rate;
87 struct hlist_node clks_node;
88};
89
90/*** locking ***/
91static void clk_prepare_lock(void)
92{
93 if (!mutex_trylock(&prepare_lock)) {
94 if (prepare_owner == current) {
95 prepare_refcnt++;
96 return;
97 }
98 mutex_lock(&prepare_lock);
99 }
100 WARN_ON_ONCE(prepare_owner != NULL);
101 WARN_ON_ONCE(prepare_refcnt != 0);
102 prepare_owner = current;
103 prepare_refcnt = 1;
104}
105
106static void clk_prepare_unlock(void)
107{
108 WARN_ON_ONCE(prepare_owner != current);
109 WARN_ON_ONCE(prepare_refcnt == 0);
110
111 if (--prepare_refcnt)
112 return;
113 prepare_owner = NULL;
114 mutex_unlock(&prepare_lock);
115}
116
117static unsigned long clk_enable_lock(void)
118 __acquires(enable_lock)
119{
120 unsigned long flags;
121
122 if (!spin_trylock_irqsave(&enable_lock, flags)) {
123 if (enable_owner == current) {
124 enable_refcnt++;
125 __acquire(enable_lock);
126 return flags;
127 }
128 spin_lock_irqsave(&enable_lock, flags);
129 }
130 WARN_ON_ONCE(enable_owner != NULL);
131 WARN_ON_ONCE(enable_refcnt != 0);
132 enable_owner = current;
133 enable_refcnt = 1;
134 return flags;
135}
136
137static void clk_enable_unlock(unsigned long flags)
138 __releases(enable_lock)
139{
140 WARN_ON_ONCE(enable_owner != current);
141 WARN_ON_ONCE(enable_refcnt == 0);
142
143 if (--enable_refcnt) {
144 __release(enable_lock);
145 return;
146 }
147 enable_owner = NULL;
148 spin_unlock_irqrestore(&enable_lock, flags);
149}
150
151static bool clk_core_is_prepared(struct clk_core *core)
152{
153 /*
154 * .is_prepared is optional for clocks that can prepare
155 * fall back to software usage counter if it is missing
156 */
157 if (!core->ops->is_prepared)
158 return core->prepare_count;
159
160 return core->ops->is_prepared(core->hw);
161}
162
163static bool clk_core_is_enabled(struct clk_core *core)
164{
165 /*
166 * .is_enabled is only mandatory for clocks that gate
167 * fall back to software usage counter if .is_enabled is missing
168 */
169 if (!core->ops->is_enabled)
170 return core->enable_count;
171
172 return core->ops->is_enabled(core->hw);
173}
174
175/*** helper functions ***/
176
177const char *__clk_get_name(const struct clk *clk)
178{
179 return !clk ? NULL : clk->core->name;
180}
181EXPORT_SYMBOL_GPL(__clk_get_name);
182
183const char *clk_hw_get_name(const struct clk_hw *hw)
184{
185 return hw->core->name;
186}
187EXPORT_SYMBOL_GPL(clk_hw_get_name);
188
189struct clk_hw *__clk_get_hw(struct clk *clk)
190{
191 return !clk ? NULL : clk->core->hw;
192}
193EXPORT_SYMBOL_GPL(__clk_get_hw);
194
195unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
196{
197 return hw->core->num_parents;
198}
199EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
200
201struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
202{
203 return hw->core->parent ? hw->core->parent->hw : NULL;
204}
205EXPORT_SYMBOL_GPL(clk_hw_get_parent);
206
207static struct clk_core *__clk_lookup_subtree(const char *name,
208 struct clk_core *core)
209{
210 struct clk_core *child;
211 struct clk_core *ret;
212
213 if (!strcmp(core->name, name))
214 return core;
215
216 hlist_for_each_entry(child, &core->children, child_node) {
217 ret = __clk_lookup_subtree(name, child);
218 if (ret)
219 return ret;
220 }
221
222 return NULL;
223}
224
225static struct clk_core *clk_core_lookup(const char *name)
226{
227 struct clk_core *root_clk;
228 struct clk_core *ret;
229
230 if (!name)
231 return NULL;
232
233 /* search the 'proper' clk tree first */
234 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
235 ret = __clk_lookup_subtree(name, root_clk);
236 if (ret)
237 return ret;
238 }
239
240 /* if not found, then search the orphan tree */
241 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
242 ret = __clk_lookup_subtree(name, root_clk);
243 if (ret)
244 return ret;
245 }
246
247 return NULL;
248}
249
250static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
251 u8 index)
252{
253 if (!core || index >= core->num_parents)
254 return NULL;
255
256 if (!core->parents[index])
257 core->parents[index] =
258 clk_core_lookup(core->parent_names[index]);
259
260 return core->parents[index];
261}
262
263struct clk_hw *
264clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
265{
266 struct clk_core *parent;
267
268 parent = clk_core_get_parent_by_index(hw->core, index);
269
270 return !parent ? NULL : parent->hw;
271}
272EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
273
274unsigned int __clk_get_enable_count(struct clk *clk)
275{
276 return !clk ? 0 : clk->core->enable_count;
277}
278
279static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
280{
281 unsigned long ret;
282
283 if (!core) {
284 ret = 0;
285 goto out;
286 }
287
288 ret = core->rate;
289
290 if (!core->num_parents)
291 goto out;
292
293 if (!core->parent)
294 ret = 0;
295
296out:
297 return ret;
298}
299
300unsigned long clk_hw_get_rate(const struct clk_hw *hw)
301{
302 return clk_core_get_rate_nolock(hw->core);
303}
304EXPORT_SYMBOL_GPL(clk_hw_get_rate);
305
306static unsigned long __clk_get_accuracy(struct clk_core *core)
307{
308 if (!core)
309 return 0;
310
311 return core->accuracy;
312}
313
314unsigned long __clk_get_flags(struct clk *clk)
315{
316 return !clk ? 0 : clk->core->flags;
317}
318EXPORT_SYMBOL_GPL(__clk_get_flags);
319
320unsigned long clk_hw_get_flags(const struct clk_hw *hw)
321{
322 return hw->core->flags;
323}
324EXPORT_SYMBOL_GPL(clk_hw_get_flags);
325
326bool clk_hw_is_prepared(const struct clk_hw *hw)
327{
328 return clk_core_is_prepared(hw->core);
329}
330
331bool clk_hw_is_enabled(const struct clk_hw *hw)
332{
333 return clk_core_is_enabled(hw->core);
334}
335
336bool __clk_is_enabled(struct clk *clk)
337{
338 if (!clk)
339 return false;
340
341 return clk_core_is_enabled(clk->core);
342}
343EXPORT_SYMBOL_GPL(__clk_is_enabled);
344
345static bool mux_is_better_rate(unsigned long rate, unsigned long now,
346 unsigned long best, unsigned long flags)
347{
348 if (flags & CLK_MUX_ROUND_CLOSEST)
349 return abs(now - rate) < abs(best - rate);
350
351 return now <= rate && now > best;
352}
353
354static int
355clk_mux_determine_rate_flags(struct clk_hw *hw, struct clk_rate_request *req,
356 unsigned long flags)
357{
358 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
359 int i, num_parents, ret;
360 unsigned long best = 0;
361 struct clk_rate_request parent_req = *req;
362
363 /* if NO_REPARENT flag set, pass through to current parent */
364 if (core->flags & CLK_SET_RATE_NO_REPARENT) {
365 parent = core->parent;
366 if (core->flags & CLK_SET_RATE_PARENT) {
367 ret = __clk_determine_rate(parent ? parent->hw : NULL,
368 &parent_req);
369 if (ret)
370 return ret;
371
372 best = parent_req.rate;
373 } else if (parent) {
374 best = clk_core_get_rate_nolock(parent);
375 } else {
376 best = clk_core_get_rate_nolock(core);
377 }
378
379 goto out;
380 }
381
382 /* find the parent that can provide the fastest rate <= rate */
383 num_parents = core->num_parents;
384 for (i = 0; i < num_parents; i++) {
385 parent = clk_core_get_parent_by_index(core, i);
386 if (!parent)
387 continue;
388
389 if (core->flags & CLK_SET_RATE_PARENT) {
390 parent_req = *req;
391 ret = __clk_determine_rate(parent->hw, &parent_req);
392 if (ret)
393 continue;
394 } else {
395 parent_req.rate = clk_core_get_rate_nolock(parent);
396 }
397
398 if (mux_is_better_rate(req->rate, parent_req.rate,
399 best, flags)) {
400 best_parent = parent;
401 best = parent_req.rate;
402 }
403 }
404
405 if (!best_parent)
406 return -EINVAL;
407
408out:
409 if (best_parent)
410 req->best_parent_hw = best_parent->hw;
411 req->best_parent_rate = best;
412 req->rate = best;
413
414 return 0;
415}
416
417struct clk *__clk_lookup(const char *name)
418{
419 struct clk_core *core = clk_core_lookup(name);
420
421 return !core ? NULL : core->hw->clk;
422}
423
424static void clk_core_get_boundaries(struct clk_core *core,
425 unsigned long *min_rate,
426 unsigned long *max_rate)
427{
428 struct clk *clk_user;
429
430 *min_rate = core->min_rate;
431 *max_rate = core->max_rate;
432
433 hlist_for_each_entry(clk_user, &core->clks, clks_node)
434 *min_rate = max(*min_rate, clk_user->min_rate);
435
436 hlist_for_each_entry(clk_user, &core->clks, clks_node)
437 *max_rate = min(*max_rate, clk_user->max_rate);
438}
439
440void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
441 unsigned long max_rate)
442{
443 hw->core->min_rate = min_rate;
444 hw->core->max_rate = max_rate;
445}
446EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
447
448/*
449 * Helper for finding best parent to provide a given frequency. This can be used
450 * directly as a determine_rate callback (e.g. for a mux), or from a more
451 * complex clock that may combine a mux with other operations.
452 */
453int __clk_mux_determine_rate(struct clk_hw *hw,
454 struct clk_rate_request *req)
455{
456 return clk_mux_determine_rate_flags(hw, req, 0);
457}
458EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
459
460int __clk_mux_determine_rate_closest(struct clk_hw *hw,
461 struct clk_rate_request *req)
462{
463 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
464}
465EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
466
467/*** clk api ***/
468
469static void clk_core_unprepare(struct clk_core *core)
470{
471 lockdep_assert_held(&prepare_lock);
472
473 if (!core)
474 return;
475
476 if (WARN_ON(core->prepare_count == 0))
477 return;
478
479 if (WARN_ON(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL))
480 return;
481
482 if (--core->prepare_count > 0)
483 return;
484
485 WARN_ON(core->enable_count > 0);
486
487 trace_clk_unprepare(core);
488
489 if (core->ops->unprepare)
490 core->ops->unprepare(core->hw);
491
492 trace_clk_unprepare_complete(core);
493 clk_core_unprepare(core->parent);
494}
495
496static void clk_core_unprepare_lock(struct clk_core *core)
497{
498 clk_prepare_lock();
499 clk_core_unprepare(core);
500 clk_prepare_unlock();
501}
502
503/**
504 * clk_unprepare - undo preparation of a clock source
505 * @clk: the clk being unprepared
506 *
507 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
508 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
509 * if the operation may sleep. One example is a clk which is accessed over
510 * I2c. In the complex case a clk gate operation may require a fast and a slow
511 * part. It is this reason that clk_unprepare and clk_disable are not mutually
512 * exclusive. In fact clk_disable must be called before clk_unprepare.
513 */
514void clk_unprepare(struct clk *clk)
515{
516 if (IS_ERR_OR_NULL(clk))
517 return;
518
519 clk_core_unprepare_lock(clk->core);
520}
521EXPORT_SYMBOL_GPL(clk_unprepare);
522
523static int clk_core_prepare(struct clk_core *core)
524{
525 int ret = 0;
526
527 lockdep_assert_held(&prepare_lock);
528
529 if (!core)
530 return 0;
531
532 if (core->prepare_count == 0) {
533 ret = clk_core_prepare(core->parent);
534 if (ret)
535 return ret;
536
537 trace_clk_prepare(core);
538
539 if (core->ops->prepare)
540 ret = core->ops->prepare(core->hw);
541
542 trace_clk_prepare_complete(core);
543
544 if (ret) {
545 clk_core_unprepare(core->parent);
546 return ret;
547 }
548 }
549
550 core->prepare_count++;
551
552 return 0;
553}
554
555static int clk_core_prepare_lock(struct clk_core *core)
556{
557 int ret;
558
559 clk_prepare_lock();
560 ret = clk_core_prepare(core);
561 clk_prepare_unlock();
562
563 return ret;
564}
565
566/**
567 * clk_prepare - prepare a clock source
568 * @clk: the clk being prepared
569 *
570 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
571 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
572 * operation may sleep. One example is a clk which is accessed over I2c. In
573 * the complex case a clk ungate operation may require a fast and a slow part.
574 * It is this reason that clk_prepare and clk_enable are not mutually
575 * exclusive. In fact clk_prepare must be called before clk_enable.
576 * Returns 0 on success, -EERROR otherwise.
577 */
578int clk_prepare(struct clk *clk)
579{
580 if (!clk)
581 return 0;
582
583 return clk_core_prepare_lock(clk->core);
584}
585EXPORT_SYMBOL_GPL(clk_prepare);
586
587static void clk_core_disable(struct clk_core *core)
588{
589 lockdep_assert_held(&enable_lock);
590
591 if (!core)
592 return;
593
594 if (WARN_ON(core->enable_count == 0))
595 return;
596
597 if (WARN_ON(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL))
598 return;
599
600 if (--core->enable_count > 0)
601 return;
602
603 trace_clk_disable_rcuidle(core);
604
605 if (core->ops->disable)
606 core->ops->disable(core->hw);
607
608 trace_clk_disable_complete_rcuidle(core);
609
610 clk_core_disable(core->parent);
611}
612
613static void clk_core_disable_lock(struct clk_core *core)
614{
615 unsigned long flags;
616
617 flags = clk_enable_lock();
618 clk_core_disable(core);
619 clk_enable_unlock(flags);
620}
621
622/**
623 * clk_disable - gate a clock
624 * @clk: the clk being gated
625 *
626 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
627 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
628 * clk if the operation is fast and will never sleep. One example is a
629 * SoC-internal clk which is controlled via simple register writes. In the
630 * complex case a clk gate operation may require a fast and a slow part. It is
631 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
632 * In fact clk_disable must be called before clk_unprepare.
633 */
634void clk_disable(struct clk *clk)
635{
636 if (IS_ERR_OR_NULL(clk))
637 return;
638
639 clk_core_disable_lock(clk->core);
640}
641EXPORT_SYMBOL_GPL(clk_disable);
642
643static int clk_core_enable(struct clk_core *core)
644{
645 int ret = 0;
646
647 lockdep_assert_held(&enable_lock);
648
649 if (!core)
650 return 0;
651
652 if (WARN_ON(core->prepare_count == 0))
653 return -ESHUTDOWN;
654
655 if (core->enable_count == 0) {
656 ret = clk_core_enable(core->parent);
657
658 if (ret)
659 return ret;
660
661 trace_clk_enable_rcuidle(core);
662
663 if (core->ops->enable)
664 ret = core->ops->enable(core->hw);
665
666 trace_clk_enable_complete_rcuidle(core);
667
668 if (ret) {
669 clk_core_disable(core->parent);
670 return ret;
671 }
672 }
673
674 core->enable_count++;
675 return 0;
676}
677
678static int clk_core_enable_lock(struct clk_core *core)
679{
680 unsigned long flags;
681 int ret;
682
683 flags = clk_enable_lock();
684 ret = clk_core_enable(core);
685 clk_enable_unlock(flags);
686
687 return ret;
688}
689
690/**
691 * clk_enable - ungate a clock
692 * @clk: the clk being ungated
693 *
694 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
695 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
696 * if the operation will never sleep. One example is a SoC-internal clk which
697 * is controlled via simple register writes. In the complex case a clk ungate
698 * operation may require a fast and a slow part. It is this reason that
699 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
700 * must be called before clk_enable. Returns 0 on success, -EERROR
701 * otherwise.
702 */
703int clk_enable(struct clk *clk)
704{
705 if (!clk)
706 return 0;
707
708 return clk_core_enable_lock(clk->core);
709}
710EXPORT_SYMBOL_GPL(clk_enable);
711
712static int clk_core_prepare_enable(struct clk_core *core)
713{
714 int ret;
715
716 ret = clk_core_prepare_lock(core);
717 if (ret)
718 return ret;
719
720 ret = clk_core_enable_lock(core);
721 if (ret)
722 clk_core_unprepare_lock(core);
723
724 return ret;
725}
726
727static void clk_core_disable_unprepare(struct clk_core *core)
728{
729 clk_core_disable_lock(core);
730 clk_core_unprepare_lock(core);
731}
732
733static void clk_unprepare_unused_subtree(struct clk_core *core)
734{
735 struct clk_core *child;
736
737 lockdep_assert_held(&prepare_lock);
738
739 hlist_for_each_entry(child, &core->children, child_node)
740 clk_unprepare_unused_subtree(child);
741
742 if (core->prepare_count)
743 return;
744
745 if (core->flags & CLK_IGNORE_UNUSED)
746 return;
747
748 if (clk_core_is_prepared(core)) {
749 trace_clk_unprepare(core);
750 if (core->ops->unprepare_unused)
751 core->ops->unprepare_unused(core->hw);
752 else if (core->ops->unprepare)
753 core->ops->unprepare(core->hw);
754 trace_clk_unprepare_complete(core);
755 }
756}
757
758static void clk_disable_unused_subtree(struct clk_core *core)
759{
760 struct clk_core *child;
761 unsigned long flags;
762
763 lockdep_assert_held(&prepare_lock);
764
765 hlist_for_each_entry(child, &core->children, child_node)
766 clk_disable_unused_subtree(child);
767
768 if (core->flags & CLK_OPS_PARENT_ENABLE)
769 clk_core_prepare_enable(core->parent);
770
771 flags = clk_enable_lock();
772
773 if (core->enable_count)
774 goto unlock_out;
775
776 if (core->flags & CLK_IGNORE_UNUSED)
777 goto unlock_out;
778
779 /*
780 * some gate clocks have special needs during the disable-unused
781 * sequence. call .disable_unused if available, otherwise fall
782 * back to .disable
783 */
784 if (clk_core_is_enabled(core)) {
785 trace_clk_disable(core);
786 if (core->ops->disable_unused)
787 core->ops->disable_unused(core->hw);
788 else if (core->ops->disable)
789 core->ops->disable(core->hw);
790 trace_clk_disable_complete(core);
791 }
792
793unlock_out:
794 clk_enable_unlock(flags);
795 if (core->flags & CLK_OPS_PARENT_ENABLE)
796 clk_core_disable_unprepare(core->parent);
797}
798
799static bool clk_ignore_unused;
800static int __init clk_ignore_unused_setup(char *__unused)
801{
802 clk_ignore_unused = true;
803 return 1;
804}
805__setup("clk_ignore_unused", clk_ignore_unused_setup);
806
807static int clk_disable_unused(void)
808{
809 struct clk_core *core;
810
811 if (clk_ignore_unused) {
812 pr_warn("clk: Not disabling unused clocks\n");
813 return 0;
814 }
815
816 clk_prepare_lock();
817
818 hlist_for_each_entry(core, &clk_root_list, child_node)
819 clk_disable_unused_subtree(core);
820
821 hlist_for_each_entry(core, &clk_orphan_list, child_node)
822 clk_disable_unused_subtree(core);
823
824 hlist_for_each_entry(core, &clk_root_list, child_node)
825 clk_unprepare_unused_subtree(core);
826
827 hlist_for_each_entry(core, &clk_orphan_list, child_node)
828 clk_unprepare_unused_subtree(core);
829
830 clk_prepare_unlock();
831
832 return 0;
833}
834late_initcall_sync(clk_disable_unused);
835
836static int clk_core_round_rate_nolock(struct clk_core *core,
837 struct clk_rate_request *req)
838{
839 struct clk_core *parent;
840 long rate;
841
842 lockdep_assert_held(&prepare_lock);
843
844 if (!core)
845 return 0;
846
847 parent = core->parent;
848 if (parent) {
849 req->best_parent_hw = parent->hw;
850 req->best_parent_rate = parent->rate;
851 } else {
852 req->best_parent_hw = NULL;
853 req->best_parent_rate = 0;
854 }
855
856 if (core->ops->determine_rate) {
857 return core->ops->determine_rate(core->hw, req);
858 } else if (core->ops->round_rate) {
859 rate = core->ops->round_rate(core->hw, req->rate,
860 &req->best_parent_rate);
861 if (rate < 0)
862 return rate;
863
864 req->rate = rate;
865 } else if (core->flags & CLK_SET_RATE_PARENT) {
866 return clk_core_round_rate_nolock(parent, req);
867 } else {
868 req->rate = core->rate;
869 }
870
871 return 0;
872}
873
874/**
875 * __clk_determine_rate - get the closest rate actually supported by a clock
876 * @hw: determine the rate of this clock
877 * @req: target rate request
878 *
879 * Useful for clk_ops such as .set_rate and .determine_rate.
880 */
881int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
882{
883 if (!hw) {
884 req->rate = 0;
885 return 0;
886 }
887
888 return clk_core_round_rate_nolock(hw->core, req);
889}
890EXPORT_SYMBOL_GPL(__clk_determine_rate);
891
892unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
893{
894 int ret;
895 struct clk_rate_request req;
896
897 clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate);
898 req.rate = rate;
899
900 ret = clk_core_round_rate_nolock(hw->core, &req);
901 if (ret)
902 return 0;
903
904 return req.rate;
905}
906EXPORT_SYMBOL_GPL(clk_hw_round_rate);
907
908/**
909 * clk_round_rate - round the given rate for a clk
910 * @clk: the clk for which we are rounding a rate
911 * @rate: the rate which is to be rounded
912 *
913 * Takes in a rate as input and rounds it to a rate that the clk can actually
914 * use which is then returned. If clk doesn't support round_rate operation
915 * then the parent rate is returned.
916 */
917long clk_round_rate(struct clk *clk, unsigned long rate)
918{
919 struct clk_rate_request req;
920 int ret;
921
922 if (!clk)
923 return 0;
924
925 clk_prepare_lock();
926
927 clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
928 req.rate = rate;
929
930 ret = clk_core_round_rate_nolock(clk->core, &req);
931 clk_prepare_unlock();
932
933 if (ret)
934 return ret;
935
936 return req.rate;
937}
938EXPORT_SYMBOL_GPL(clk_round_rate);
939
940/**
941 * __clk_notify - call clk notifier chain
942 * @core: clk that is changing rate
943 * @msg: clk notifier type (see include/linux/clk.h)
944 * @old_rate: old clk rate
945 * @new_rate: new clk rate
946 *
947 * Triggers a notifier call chain on the clk rate-change notification
948 * for 'clk'. Passes a pointer to the struct clk and the previous
949 * and current rates to the notifier callback. Intended to be called by
950 * internal clock code only. Returns NOTIFY_DONE from the last driver
951 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
952 * a driver returns that.
953 */
954static int __clk_notify(struct clk_core *core, unsigned long msg,
955 unsigned long old_rate, unsigned long new_rate)
956{
957 struct clk_notifier *cn;
958 struct clk_notifier_data cnd;
959 int ret = NOTIFY_DONE;
960
961 cnd.old_rate = old_rate;
962 cnd.new_rate = new_rate;
963
964 list_for_each_entry(cn, &clk_notifier_list, node) {
965 if (cn->clk->core == core) {
966 cnd.clk = cn->clk;
967 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
968 &cnd);
969 }
970 }
971
972 return ret;
973}
974
975/**
976 * __clk_recalc_accuracies
977 * @core: first clk in the subtree
978 *
979 * Walks the subtree of clks starting with clk and recalculates accuracies as
980 * it goes. Note that if a clk does not implement the .recalc_accuracy
981 * callback then it is assumed that the clock will take on the accuracy of its
982 * parent.
983 */
984static void __clk_recalc_accuracies(struct clk_core *core)
985{
986 unsigned long parent_accuracy = 0;
987 struct clk_core *child;
988
989 lockdep_assert_held(&prepare_lock);
990
991 if (core->parent)
992 parent_accuracy = core->parent->accuracy;
993
994 if (core->ops->recalc_accuracy)
995 core->accuracy = core->ops->recalc_accuracy(core->hw,
996 parent_accuracy);
997 else
998 core->accuracy = parent_accuracy;
999
1000 hlist_for_each_entry(child, &core->children, child_node)
1001 __clk_recalc_accuracies(child);
1002}
1003
1004static long clk_core_get_accuracy(struct clk_core *core)
1005{
1006 unsigned long accuracy;
1007
1008 clk_prepare_lock();
1009 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
1010 __clk_recalc_accuracies(core);
1011
1012 accuracy = __clk_get_accuracy(core);
1013 clk_prepare_unlock();
1014
1015 return accuracy;
1016}
1017
1018/**
1019 * clk_get_accuracy - return the accuracy of clk
1020 * @clk: the clk whose accuracy is being returned
1021 *
1022 * Simply returns the cached accuracy of the clk, unless
1023 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1024 * issued.
1025 * If clk is NULL then returns 0.
1026 */
1027long clk_get_accuracy(struct clk *clk)
1028{
1029 if (!clk)
1030 return 0;
1031
1032 return clk_core_get_accuracy(clk->core);
1033}
1034EXPORT_SYMBOL_GPL(clk_get_accuracy);
1035
1036static unsigned long clk_recalc(struct clk_core *core,
1037 unsigned long parent_rate)
1038{
1039 if (core->ops->recalc_rate)
1040 return core->ops->recalc_rate(core->hw, parent_rate);
1041 return parent_rate;
1042}
1043
1044/**
1045 * __clk_recalc_rates
1046 * @core: first clk in the subtree
1047 * @msg: notification type (see include/linux/clk.h)
1048 *
1049 * Walks the subtree of clks starting with clk and recalculates rates as it
1050 * goes. Note that if a clk does not implement the .recalc_rate callback then
1051 * it is assumed that the clock will take on the rate of its parent.
1052 *
1053 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1054 * if necessary.
1055 */
1056static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
1057{
1058 unsigned long old_rate;
1059 unsigned long parent_rate = 0;
1060 struct clk_core *child;
1061
1062 lockdep_assert_held(&prepare_lock);
1063
1064 old_rate = core->rate;
1065
1066 if (core->parent)
1067 parent_rate = core->parent->rate;
1068
1069 core->rate = clk_recalc(core, parent_rate);
1070
1071 /*
1072 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1073 * & ABORT_RATE_CHANGE notifiers
1074 */
1075 if (core->notifier_count && msg)
1076 __clk_notify(core, msg, old_rate, core->rate);
1077
1078 hlist_for_each_entry(child, &core->children, child_node)
1079 __clk_recalc_rates(child, msg);
1080}
1081
1082static unsigned long clk_core_get_rate(struct clk_core *core)
1083{
1084 unsigned long rate;
1085
1086 clk_prepare_lock();
1087
1088 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1089 __clk_recalc_rates(core, 0);
1090
1091 rate = clk_core_get_rate_nolock(core);
1092 clk_prepare_unlock();
1093
1094 return rate;
1095}
1096
1097/**
1098 * clk_get_rate - return the rate of clk
1099 * @clk: the clk whose rate is being returned
1100 *
1101 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1102 * is set, which means a recalc_rate will be issued.
1103 * If clk is NULL then returns 0.
1104 */
1105unsigned long clk_get_rate(struct clk *clk)
1106{
1107 if (!clk)
1108 return 0;
1109
1110 return clk_core_get_rate(clk->core);
1111}
1112EXPORT_SYMBOL_GPL(clk_get_rate);
1113
1114static int clk_fetch_parent_index(struct clk_core *core,
1115 struct clk_core *parent)
1116{
1117 int i;
1118
1119 if (!parent)
1120 return -EINVAL;
1121
1122 for (i = 0; i < core->num_parents; i++)
1123 if (clk_core_get_parent_by_index(core, i) == parent)
1124 return i;
1125
1126 return -EINVAL;
1127}
1128
1129/*
1130 * Update the orphan status of @core and all its children.
1131 */
1132static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
1133{
1134 struct clk_core *child;
1135
1136 core->orphan = is_orphan;
1137
1138 hlist_for_each_entry(child, &core->children, child_node)
1139 clk_core_update_orphan_status(child, is_orphan);
1140}
1141
1142static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1143{
1144 bool was_orphan = core->orphan;
1145
1146 hlist_del(&core->child_node);
1147
1148 if (new_parent) {
1149 bool becomes_orphan = new_parent->orphan;
1150
1151 /* avoid duplicate POST_RATE_CHANGE notifications */
1152 if (new_parent->new_child == core)
1153 new_parent->new_child = NULL;
1154
1155 hlist_add_head(&core->child_node, &new_parent->children);
1156
1157 if (was_orphan != becomes_orphan)
1158 clk_core_update_orphan_status(core, becomes_orphan);
1159 } else {
1160 hlist_add_head(&core->child_node, &clk_orphan_list);
1161 if (!was_orphan)
1162 clk_core_update_orphan_status(core, true);
1163 }
1164
1165 core->parent = new_parent;
1166}
1167
1168static struct clk_core *__clk_set_parent_before(struct clk_core *core,
1169 struct clk_core *parent)
1170{
1171 unsigned long flags;
1172 struct clk_core *old_parent = core->parent;
1173
1174 /*
1175 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
1176 *
1177 * 2. Migrate prepare state between parents and prevent race with
1178 * clk_enable().
1179 *
1180 * If the clock is not prepared, then a race with
1181 * clk_enable/disable() is impossible since we already have the
1182 * prepare lock (future calls to clk_enable() need to be preceded by
1183 * a clk_prepare()).
1184 *
1185 * If the clock is prepared, migrate the prepared state to the new
1186 * parent and also protect against a race with clk_enable() by
1187 * forcing the clock and the new parent on. This ensures that all
1188 * future calls to clk_enable() are practically NOPs with respect to
1189 * hardware and software states.
1190 *
1191 * See also: Comment for clk_set_parent() below.
1192 */
1193
1194 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
1195 if (core->flags & CLK_OPS_PARENT_ENABLE) {
1196 clk_core_prepare_enable(old_parent);
1197 clk_core_prepare_enable(parent);
1198 }
1199
1200 /* migrate prepare count if > 0 */
1201 if (core->prepare_count) {
1202 clk_core_prepare_enable(parent);
1203 clk_core_enable_lock(core);
1204 }
1205
1206 /* update the clk tree topology */
1207 flags = clk_enable_lock();
1208 clk_reparent(core, parent);
1209 clk_enable_unlock(flags);
1210
1211 return old_parent;
1212}
1213
1214static void __clk_set_parent_after(struct clk_core *core,
1215 struct clk_core *parent,
1216 struct clk_core *old_parent)
1217{
1218 /*
1219 * Finish the migration of prepare state and undo the changes done
1220 * for preventing a race with clk_enable().
1221 */
1222 if (core->prepare_count) {
1223 clk_core_disable_lock(core);
1224 clk_core_disable_unprepare(old_parent);
1225 }
1226
1227 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
1228 if (core->flags & CLK_OPS_PARENT_ENABLE) {
1229 clk_core_disable_unprepare(parent);
1230 clk_core_disable_unprepare(old_parent);
1231 }
1232}
1233
1234static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
1235 u8 p_index)
1236{
1237 unsigned long flags;
1238 int ret = 0;
1239 struct clk_core *old_parent;
1240
1241 old_parent = __clk_set_parent_before(core, parent);
1242
1243 trace_clk_set_parent(core, parent);
1244
1245 /* change clock input source */
1246 if (parent && core->ops->set_parent)
1247 ret = core->ops->set_parent(core->hw, p_index);
1248
1249 trace_clk_set_parent_complete(core, parent);
1250
1251 if (ret) {
1252 flags = clk_enable_lock();
1253 clk_reparent(core, old_parent);
1254 clk_enable_unlock(flags);
1255 __clk_set_parent_after(core, old_parent, parent);
1256
1257 return ret;
1258 }
1259
1260 __clk_set_parent_after(core, parent, old_parent);
1261
1262 return 0;
1263}
1264
1265/**
1266 * __clk_speculate_rates
1267 * @core: first clk in the subtree
1268 * @parent_rate: the "future" rate of clk's parent
1269 *
1270 * Walks the subtree of clks starting with clk, speculating rates as it
1271 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1272 *
1273 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1274 * pre-rate change notifications and returns early if no clks in the
1275 * subtree have subscribed to the notifications. Note that if a clk does not
1276 * implement the .recalc_rate callback then it is assumed that the clock will
1277 * take on the rate of its parent.
1278 */
1279static int __clk_speculate_rates(struct clk_core *core,
1280 unsigned long parent_rate)
1281{
1282 struct clk_core *child;
1283 unsigned long new_rate;
1284 int ret = NOTIFY_DONE;
1285
1286 lockdep_assert_held(&prepare_lock);
1287
1288 new_rate = clk_recalc(core, parent_rate);
1289
1290 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1291 if (core->notifier_count)
1292 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
1293
1294 if (ret & NOTIFY_STOP_MASK) {
1295 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1296 __func__, core->name, ret);
1297 goto out;
1298 }
1299
1300 hlist_for_each_entry(child, &core->children, child_node) {
1301 ret = __clk_speculate_rates(child, new_rate);
1302 if (ret & NOTIFY_STOP_MASK)
1303 break;
1304 }
1305
1306out:
1307 return ret;
1308}
1309
1310static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
1311 struct clk_core *new_parent, u8 p_index)
1312{
1313 struct clk_core *child;
1314
1315 core->new_rate = new_rate;
1316 core->new_parent = new_parent;
1317 core->new_parent_index = p_index;
1318 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1319 core->new_child = NULL;
1320 if (new_parent && new_parent != core->parent)
1321 new_parent->new_child = core;
1322
1323 hlist_for_each_entry(child, &core->children, child_node) {
1324 child->new_rate = clk_recalc(child, new_rate);
1325 clk_calc_subtree(child, child->new_rate, NULL, 0);
1326 }
1327}
1328
1329/*
1330 * calculate the new rates returning the topmost clock that has to be
1331 * changed.
1332 */
1333static struct clk_core *clk_calc_new_rates(struct clk_core *core,
1334 unsigned long rate)
1335{
1336 struct clk_core *top = core;
1337 struct clk_core *old_parent, *parent;
1338 unsigned long best_parent_rate = 0;
1339 unsigned long new_rate;
1340 unsigned long min_rate;
1341 unsigned long max_rate;
1342 int p_index = 0;
1343 long ret;
1344
1345 /* sanity */
1346 if (IS_ERR_OR_NULL(core))
1347 return NULL;
1348
1349 /* save parent rate, if it exists */
1350 parent = old_parent = core->parent;
1351 if (parent)
1352 best_parent_rate = parent->rate;
1353
1354 clk_core_get_boundaries(core, &min_rate, &max_rate);
1355
1356 /* find the closest rate and parent clk/rate */
1357 if (core->ops->determine_rate) {
1358 struct clk_rate_request req;
1359
1360 req.rate = rate;
1361 req.min_rate = min_rate;
1362 req.max_rate = max_rate;
1363 if (parent) {
1364 req.best_parent_hw = parent->hw;
1365 req.best_parent_rate = parent->rate;
1366 } else {
1367 req.best_parent_hw = NULL;
1368 req.best_parent_rate = 0;
1369 }
1370
1371 ret = core->ops->determine_rate(core->hw, &req);
1372 if (ret < 0)
1373 return NULL;
1374
1375 best_parent_rate = req.best_parent_rate;
1376 new_rate = req.rate;
1377 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
1378 } else if (core->ops->round_rate) {
1379 ret = core->ops->round_rate(core->hw, rate,
1380 &best_parent_rate);
1381 if (ret < 0)
1382 return NULL;
1383
1384 new_rate = ret;
1385 if (new_rate < min_rate || new_rate > max_rate)
1386 return NULL;
1387 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
1388 /* pass-through clock without adjustable parent */
1389 core->new_rate = core->rate;
1390 return NULL;
1391 } else {
1392 /* pass-through clock with adjustable parent */
1393 top = clk_calc_new_rates(parent, rate);
1394 new_rate = parent->new_rate;
1395 goto out;
1396 }
1397
1398 /* some clocks must be gated to change parent */
1399 if (parent != old_parent &&
1400 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1401 pr_debug("%s: %s not gated but wants to reparent\n",
1402 __func__, core->name);
1403 return NULL;
1404 }
1405
1406 /* try finding the new parent index */
1407 if (parent && core->num_parents > 1) {
1408 p_index = clk_fetch_parent_index(core, parent);
1409 if (p_index < 0) {
1410 pr_debug("%s: clk %s can not be parent of clk %s\n",
1411 __func__, parent->name, core->name);
1412 return NULL;
1413 }
1414 }
1415
1416 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
1417 best_parent_rate != parent->rate)
1418 top = clk_calc_new_rates(parent, best_parent_rate);
1419
1420out:
1421 clk_calc_subtree(core, new_rate, parent, p_index);
1422
1423 return top;
1424}
1425
1426/*
1427 * Notify about rate changes in a subtree. Always walk down the whole tree
1428 * so that in case of an error we can walk down the whole tree again and
1429 * abort the change.
1430 */
1431static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
1432 unsigned long event)
1433{
1434 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
1435 int ret = NOTIFY_DONE;
1436
1437 if (core->rate == core->new_rate)
1438 return NULL;
1439
1440 if (core->notifier_count) {
1441 ret = __clk_notify(core, event, core->rate, core->new_rate);
1442 if (ret & NOTIFY_STOP_MASK)
1443 fail_clk = core;
1444 }
1445
1446 hlist_for_each_entry(child, &core->children, child_node) {
1447 /* Skip children who will be reparented to another clock */
1448 if (child->new_parent && child->new_parent != core)
1449 continue;
1450 tmp_clk = clk_propagate_rate_change(child, event);
1451 if (tmp_clk)
1452 fail_clk = tmp_clk;
1453 }
1454
1455 /* handle the new child who might not be in core->children yet */
1456 if (core->new_child) {
1457 tmp_clk = clk_propagate_rate_change(core->new_child, event);
1458 if (tmp_clk)
1459 fail_clk = tmp_clk;
1460 }
1461
1462 return fail_clk;
1463}
1464
1465/*
1466 * walk down a subtree and set the new rates notifying the rate
1467 * change on the way
1468 */
1469static void clk_change_rate(struct clk_core *core)
1470{
1471 struct clk_core *child;
1472 struct hlist_node *tmp;
1473 unsigned long old_rate;
1474 unsigned long best_parent_rate = 0;
1475 bool skip_set_rate = false;
1476 struct clk_core *old_parent;
1477 struct clk_core *parent = NULL;
1478
1479 old_rate = core->rate;
1480
1481 if (core->new_parent) {
1482 parent = core->new_parent;
1483 best_parent_rate = core->new_parent->rate;
1484 } else if (core->parent) {
1485 parent = core->parent;
1486 best_parent_rate = core->parent->rate;
1487 }
1488
1489 if (core->flags & CLK_SET_RATE_UNGATE) {
1490 unsigned long flags;
1491
1492 clk_core_prepare(core);
1493 flags = clk_enable_lock();
1494 clk_core_enable(core);
1495 clk_enable_unlock(flags);
1496 }
1497
1498 if (core->new_parent && core->new_parent != core->parent) {
1499 old_parent = __clk_set_parent_before(core, core->new_parent);
1500 trace_clk_set_parent(core, core->new_parent);
1501
1502 if (core->ops->set_rate_and_parent) {
1503 skip_set_rate = true;
1504 core->ops->set_rate_and_parent(core->hw, core->new_rate,
1505 best_parent_rate,
1506 core->new_parent_index);
1507 } else if (core->ops->set_parent) {
1508 core->ops->set_parent(core->hw, core->new_parent_index);
1509 }
1510
1511 trace_clk_set_parent_complete(core, core->new_parent);
1512 __clk_set_parent_after(core, core->new_parent, old_parent);
1513 }
1514
1515 if (core->flags & CLK_OPS_PARENT_ENABLE)
1516 clk_core_prepare_enable(parent);
1517
1518 trace_clk_set_rate(core, core->new_rate);
1519
1520 if (!skip_set_rate && core->ops->set_rate)
1521 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
1522
1523 trace_clk_set_rate_complete(core, core->new_rate);
1524
1525 core->rate = clk_recalc(core, best_parent_rate);
1526
1527 if (core->flags & CLK_SET_RATE_UNGATE) {
1528 unsigned long flags;
1529
1530 flags = clk_enable_lock();
1531 clk_core_disable(core);
1532 clk_enable_unlock(flags);
1533 clk_core_unprepare(core);
1534 }
1535
1536 if (core->flags & CLK_OPS_PARENT_ENABLE)
1537 clk_core_disable_unprepare(parent);
1538
1539 if (core->notifier_count && old_rate != core->rate)
1540 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
1541
1542 if (core->flags & CLK_RECALC_NEW_RATES)
1543 (void)clk_calc_new_rates(core, core->new_rate);
1544
1545 /*
1546 * Use safe iteration, as change_rate can actually swap parents
1547 * for certain clock types.
1548 */
1549 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
1550 /* Skip children who will be reparented to another clock */
1551 if (child->new_parent && child->new_parent != core)
1552 continue;
1553 clk_change_rate(child);
1554 }
1555
1556 /* handle the new child who might not be in core->children yet */
1557 if (core->new_child)
1558 clk_change_rate(core->new_child);
1559}
1560
1561static int clk_core_set_rate_nolock(struct clk_core *core,
1562 unsigned long req_rate)
1563{
1564 struct clk_core *top, *fail_clk;
1565 unsigned long rate = req_rate;
1566
1567 if (!core)
1568 return 0;
1569
1570 /* bail early if nothing to do */
1571 if (rate == clk_core_get_rate_nolock(core))
1572 return 0;
1573
1574 if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count)
1575 return -EBUSY;
1576
1577 /* calculate new rates and get the topmost changed clock */
1578 top = clk_calc_new_rates(core, rate);
1579 if (!top)
1580 return -EINVAL;
1581
1582 /* notify that we are about to change rates */
1583 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
1584 if (fail_clk) {
1585 pr_debug("%s: failed to set %s rate\n", __func__,
1586 fail_clk->name);
1587 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
1588 return -EBUSY;
1589 }
1590
1591 /* change the rates */
1592 clk_change_rate(top);
1593
1594 core->req_rate = req_rate;
1595
1596 return 0;
1597}
1598
1599/**
1600 * clk_set_rate - specify a new rate for clk
1601 * @clk: the clk whose rate is being changed
1602 * @rate: the new rate for clk
1603 *
1604 * In the simplest case clk_set_rate will only adjust the rate of clk.
1605 *
1606 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1607 * propagate up to clk's parent; whether or not this happens depends on the
1608 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1609 * after calling .round_rate then upstream parent propagation is ignored. If
1610 * *parent_rate comes back with a new rate for clk's parent then we propagate
1611 * up to clk's parent and set its rate. Upward propagation will continue
1612 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1613 * .round_rate stops requesting changes to clk's parent_rate.
1614 *
1615 * Rate changes are accomplished via tree traversal that also recalculates the
1616 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
1617 *
1618 * Returns 0 on success, -EERROR otherwise.
1619 */
1620int clk_set_rate(struct clk *clk, unsigned long rate)
1621{
1622 int ret;
1623
1624 if (!clk)
1625 return 0;
1626
1627 /* prevent racing with updates to the clock topology */
1628 clk_prepare_lock();
1629
1630 ret = clk_core_set_rate_nolock(clk->core, rate);
1631
1632 clk_prepare_unlock();
1633
1634 return ret;
1635}
1636EXPORT_SYMBOL_GPL(clk_set_rate);
1637
1638/**
1639 * clk_set_rate_range - set a rate range for a clock source
1640 * @clk: clock source
1641 * @min: desired minimum clock rate in Hz, inclusive
1642 * @max: desired maximum clock rate in Hz, inclusive
1643 *
1644 * Returns success (0) or negative errno.
1645 */
1646int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
1647{
1648 int ret = 0;
1649
1650 if (!clk)
1651 return 0;
1652
1653 if (min > max) {
1654 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
1655 __func__, clk->core->name, clk->dev_id, clk->con_id,
1656 min, max);
1657 return -EINVAL;
1658 }
1659
1660 clk_prepare_lock();
1661
1662 if (min != clk->min_rate || max != clk->max_rate) {
1663 clk->min_rate = min;
1664 clk->max_rate = max;
1665 ret = clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
1666 }
1667
1668 clk_prepare_unlock();
1669
1670 return ret;
1671}
1672EXPORT_SYMBOL_GPL(clk_set_rate_range);
1673
1674/**
1675 * clk_set_min_rate - set a minimum clock rate for a clock source
1676 * @clk: clock source
1677 * @rate: desired minimum clock rate in Hz, inclusive
1678 *
1679 * Returns success (0) or negative errno.
1680 */
1681int clk_set_min_rate(struct clk *clk, unsigned long rate)
1682{
1683 if (!clk)
1684 return 0;
1685
1686 return clk_set_rate_range(clk, rate, clk->max_rate);
1687}
1688EXPORT_SYMBOL_GPL(clk_set_min_rate);
1689
1690/**
1691 * clk_set_max_rate - set a maximum clock rate for a clock source
1692 * @clk: clock source
1693 * @rate: desired maximum clock rate in Hz, inclusive
1694 *
1695 * Returns success (0) or negative errno.
1696 */
1697int clk_set_max_rate(struct clk *clk, unsigned long rate)
1698{
1699 if (!clk)
1700 return 0;
1701
1702 return clk_set_rate_range(clk, clk->min_rate, rate);
1703}
1704EXPORT_SYMBOL_GPL(clk_set_max_rate);
1705
1706/**
1707 * clk_get_parent - return the parent of a clk
1708 * @clk: the clk whose parent gets returned
1709 *
1710 * Simply returns clk->parent. Returns NULL if clk is NULL.
1711 */
1712struct clk *clk_get_parent(struct clk *clk)
1713{
1714 struct clk *parent;
1715
1716 if (!clk)
1717 return NULL;
1718
1719 clk_prepare_lock();
1720 /* TODO: Create a per-user clk and change callers to call clk_put */
1721 parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
1722 clk_prepare_unlock();
1723
1724 return parent;
1725}
1726EXPORT_SYMBOL_GPL(clk_get_parent);
1727
1728static struct clk_core *__clk_init_parent(struct clk_core *core)
1729{
1730 u8 index = 0;
1731
1732 if (core->num_parents > 1 && core->ops->get_parent)
1733 index = core->ops->get_parent(core->hw);
1734
1735 return clk_core_get_parent_by_index(core, index);
1736}
1737
1738static void clk_core_reparent(struct clk_core *core,
1739 struct clk_core *new_parent)
1740{
1741 clk_reparent(core, new_parent);
1742 __clk_recalc_accuracies(core);
1743 __clk_recalc_rates(core, POST_RATE_CHANGE);
1744}
1745
1746void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
1747{
1748 if (!hw)
1749 return;
1750
1751 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
1752}
1753
1754/**
1755 * clk_has_parent - check if a clock is a possible parent for another
1756 * @clk: clock source
1757 * @parent: parent clock source
1758 *
1759 * This function can be used in drivers that need to check that a clock can be
1760 * the parent of another without actually changing the parent.
1761 *
1762 * Returns true if @parent is a possible parent for @clk, false otherwise.
1763 */
1764bool clk_has_parent(struct clk *clk, struct clk *parent)
1765{
1766 struct clk_core *core, *parent_core;
1767 unsigned int i;
1768
1769 /* NULL clocks should be nops, so return success if either is NULL. */
1770 if (!clk || !parent)
1771 return true;
1772
1773 core = clk->core;
1774 parent_core = parent->core;
1775
1776 /* Optimize for the case where the parent is already the parent. */
1777 if (core->parent == parent_core)
1778 return true;
1779
1780 for (i = 0; i < core->num_parents; i++)
1781 if (strcmp(core->parent_names[i], parent_core->name) == 0)
1782 return true;
1783
1784 return false;
1785}
1786EXPORT_SYMBOL_GPL(clk_has_parent);
1787
1788static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent)
1789{
1790 int ret = 0;
1791 int p_index = 0;
1792 unsigned long p_rate = 0;
1793
1794 if (!core)
1795 return 0;
1796
1797 /* prevent racing with updates to the clock topology */
1798 clk_prepare_lock();
1799
1800 if (core->parent == parent)
1801 goto out;
1802
1803 /* verify ops for for multi-parent clks */
1804 if ((core->num_parents > 1) && (!core->ops->set_parent)) {
1805 ret = -ENOSYS;
1806 goto out;
1807 }
1808
1809 /* check that we are allowed to re-parent if the clock is in use */
1810 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1811 ret = -EBUSY;
1812 goto out;
1813 }
1814
1815 /* try finding the new parent index */
1816 if (parent) {
1817 p_index = clk_fetch_parent_index(core, parent);
1818 if (p_index < 0) {
1819 pr_debug("%s: clk %s can not be parent of clk %s\n",
1820 __func__, parent->name, core->name);
1821 ret = p_index;
1822 goto out;
1823 }
1824 p_rate = parent->rate;
1825 }
1826
1827 /* propagate PRE_RATE_CHANGE notifications */
1828 ret = __clk_speculate_rates(core, p_rate);
1829
1830 /* abort if a driver objects */
1831 if (ret & NOTIFY_STOP_MASK)
1832 goto out;
1833
1834 /* do the re-parent */
1835 ret = __clk_set_parent(core, parent, p_index);
1836
1837 /* propagate rate an accuracy recalculation accordingly */
1838 if (ret) {
1839 __clk_recalc_rates(core, ABORT_RATE_CHANGE);
1840 } else {
1841 __clk_recalc_rates(core, POST_RATE_CHANGE);
1842 __clk_recalc_accuracies(core);
1843 }
1844
1845out:
1846 clk_prepare_unlock();
1847
1848 return ret;
1849}
1850
1851/**
1852 * clk_set_parent - switch the parent of a mux clk
1853 * @clk: the mux clk whose input we are switching
1854 * @parent: the new input to clk
1855 *
1856 * Re-parent clk to use parent as its new input source. If clk is in
1857 * prepared state, the clk will get enabled for the duration of this call. If
1858 * that's not acceptable for a specific clk (Eg: the consumer can't handle
1859 * that, the reparenting is glitchy in hardware, etc), use the
1860 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
1861 *
1862 * After successfully changing clk's parent clk_set_parent will update the
1863 * clk topology, sysfs topology and propagate rate recalculation via
1864 * __clk_recalc_rates.
1865 *
1866 * Returns 0 on success, -EERROR otherwise.
1867 */
1868int clk_set_parent(struct clk *clk, struct clk *parent)
1869{
1870 if (!clk)
1871 return 0;
1872
1873 return clk_core_set_parent(clk->core, parent ? parent->core : NULL);
1874}
1875EXPORT_SYMBOL_GPL(clk_set_parent);
1876
1877/**
1878 * clk_set_phase - adjust the phase shift of a clock signal
1879 * @clk: clock signal source
1880 * @degrees: number of degrees the signal is shifted
1881 *
1882 * Shifts the phase of a clock signal by the specified
1883 * degrees. Returns 0 on success, -EERROR otherwise.
1884 *
1885 * This function makes no distinction about the input or reference
1886 * signal that we adjust the clock signal phase against. For example
1887 * phase locked-loop clock signal generators we may shift phase with
1888 * respect to feedback clock signal input, but for other cases the
1889 * clock phase may be shifted with respect to some other, unspecified
1890 * signal.
1891 *
1892 * Additionally the concept of phase shift does not propagate through
1893 * the clock tree hierarchy, which sets it apart from clock rates and
1894 * clock accuracy. A parent clock phase attribute does not have an
1895 * impact on the phase attribute of a child clock.
1896 */
1897int clk_set_phase(struct clk *clk, int degrees)
1898{
1899 int ret = -EINVAL;
1900
1901 if (!clk)
1902 return 0;
1903
1904 /* sanity check degrees */
1905 degrees %= 360;
1906 if (degrees < 0)
1907 degrees += 360;
1908
1909 clk_prepare_lock();
1910
1911 trace_clk_set_phase(clk->core, degrees);
1912
1913 if (clk->core->ops->set_phase)
1914 ret = clk->core->ops->set_phase(clk->core->hw, degrees);
1915
1916 trace_clk_set_phase_complete(clk->core, degrees);
1917
1918 if (!ret)
1919 clk->core->phase = degrees;
1920
1921 clk_prepare_unlock();
1922
1923 return ret;
1924}
1925EXPORT_SYMBOL_GPL(clk_set_phase);
1926
1927static int clk_core_get_phase(struct clk_core *core)
1928{
1929 int ret;
1930
1931 clk_prepare_lock();
1932 ret = core->phase;
1933 clk_prepare_unlock();
1934
1935 return ret;
1936}
1937
1938/**
1939 * clk_get_phase - return the phase shift of a clock signal
1940 * @clk: clock signal source
1941 *
1942 * Returns the phase shift of a clock node in degrees, otherwise returns
1943 * -EERROR.
1944 */
1945int clk_get_phase(struct clk *clk)
1946{
1947 if (!clk)
1948 return 0;
1949
1950 return clk_core_get_phase(clk->core);
1951}
1952EXPORT_SYMBOL_GPL(clk_get_phase);
1953
1954/**
1955 * clk_is_match - check if two clk's point to the same hardware clock
1956 * @p: clk compared against q
1957 * @q: clk compared against p
1958 *
1959 * Returns true if the two struct clk pointers both point to the same hardware
1960 * clock node. Put differently, returns true if struct clk *p and struct clk *q
1961 * share the same struct clk_core object.
1962 *
1963 * Returns false otherwise. Note that two NULL clks are treated as matching.
1964 */
1965bool clk_is_match(const struct clk *p, const struct clk *q)
1966{
1967 /* trivial case: identical struct clk's or both NULL */
1968 if (p == q)
1969 return true;
1970
1971 /* true if clk->core pointers match. Avoid dereferencing garbage */
1972 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
1973 if (p->core == q->core)
1974 return true;
1975
1976 return false;
1977}
1978EXPORT_SYMBOL_GPL(clk_is_match);
1979
1980/*** debugfs support ***/
1981
1982#ifdef CONFIG_DEBUG_FS
1983#include <linux/debugfs.h>
1984
1985static struct dentry *rootdir;
1986static int inited = 0;
1987static DEFINE_MUTEX(clk_debug_lock);
1988static HLIST_HEAD(clk_debug_list);
1989
1990static struct hlist_head *all_lists[] = {
1991 &clk_root_list,
1992 &clk_orphan_list,
1993 NULL,
1994};
1995
1996static struct hlist_head *orphan_list[] = {
1997 &clk_orphan_list,
1998 NULL,
1999};
2000
2001static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
2002 int level)
2003{
2004 if (!c)
2005 return;
2006
2007 seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu %-3d\n",
2008 level * 3 + 1, "",
2009 30 - level * 3, c->name,
2010 c->enable_count, c->prepare_count, clk_core_get_rate(c),
2011 clk_core_get_accuracy(c), clk_core_get_phase(c));
2012}
2013
2014static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
2015 int level)
2016{
2017 struct clk_core *child;
2018
2019 if (!c)
2020 return;
2021
2022 clk_summary_show_one(s, c, level);
2023
2024 hlist_for_each_entry(child, &c->children, child_node)
2025 clk_summary_show_subtree(s, child, level + 1);
2026}
2027
2028static int clk_summary_show(struct seq_file *s, void *data)
2029{
2030 struct clk_core *c;
2031 struct hlist_head **lists = (struct hlist_head **)s->private;
2032
2033 seq_puts(s, " clock enable_cnt prepare_cnt rate accuracy phase\n");
2034 seq_puts(s, "----------------------------------------------------------------------------------------\n");
2035
2036 clk_prepare_lock();
2037
2038 for (; *lists; lists++)
2039 hlist_for_each_entry(c, *lists, child_node)
2040 clk_summary_show_subtree(s, c, 0);
2041
2042 clk_prepare_unlock();
2043
2044 return 0;
2045}
2046
2047
2048static int clk_summary_open(struct inode *inode, struct file *file)
2049{
2050 return single_open(file, clk_summary_show, inode->i_private);
2051}
2052
2053static const struct file_operations clk_summary_fops = {
2054 .open = clk_summary_open,
2055 .read = seq_read,
2056 .llseek = seq_lseek,
2057 .release = single_release,
2058};
2059
2060static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
2061{
2062 if (!c)
2063 return;
2064
2065 /* This should be JSON format, i.e. elements separated with a comma */
2066 seq_printf(s, "\"%s\": { ", c->name);
2067 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
2068 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
2069 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate(c));
2070 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c));
2071 seq_printf(s, "\"phase\": %d", clk_core_get_phase(c));
2072}
2073
2074static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
2075{
2076 struct clk_core *child;
2077
2078 if (!c)
2079 return;
2080
2081 clk_dump_one(s, c, level);
2082
2083 hlist_for_each_entry(child, &c->children, child_node) {
2084 seq_printf(s, ",");
2085 clk_dump_subtree(s, child, level + 1);
2086 }
2087
2088 seq_printf(s, "}");
2089}
2090
2091static int clk_dump(struct seq_file *s, void *data)
2092{
2093 struct clk_core *c;
2094 bool first_node = true;
2095 struct hlist_head **lists = (struct hlist_head **)s->private;
2096
2097 seq_printf(s, "{");
2098
2099 clk_prepare_lock();
2100
2101 for (; *lists; lists++) {
2102 hlist_for_each_entry(c, *lists, child_node) {
2103 if (!first_node)
2104 seq_puts(s, ",");
2105 first_node = false;
2106 clk_dump_subtree(s, c, 0);
2107 }
2108 }
2109
2110 clk_prepare_unlock();
2111
2112 seq_puts(s, "}\n");
2113 return 0;
2114}
2115
2116
2117static int clk_dump_open(struct inode *inode, struct file *file)
2118{
2119 return single_open(file, clk_dump, inode->i_private);
2120}
2121
2122static const struct file_operations clk_dump_fops = {
2123 .open = clk_dump_open,
2124 .read = seq_read,
2125 .llseek = seq_lseek,
2126 .release = single_release,
2127};
2128
2129static int clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
2130{
2131 struct dentry *d;
2132 int ret = -ENOMEM;
2133
2134 if (!core || !pdentry) {
2135 ret = -EINVAL;
2136 goto out;
2137 }
2138
2139 d = debugfs_create_dir(core->name, pdentry);
2140 if (!d)
2141 goto out;
2142
2143 core->dentry = d;
2144
2145 d = debugfs_create_u32("clk_rate", S_IRUGO, core->dentry,
2146 (u32 *)&core->rate);
2147 if (!d)
2148 goto err_out;
2149
2150 d = debugfs_create_u32("clk_accuracy", S_IRUGO, core->dentry,
2151 (u32 *)&core->accuracy);
2152 if (!d)
2153 goto err_out;
2154
2155 d = debugfs_create_u32("clk_phase", S_IRUGO, core->dentry,
2156 (u32 *)&core->phase);
2157 if (!d)
2158 goto err_out;
2159
2160 d = debugfs_create_x32("clk_flags", S_IRUGO, core->dentry,
2161 (u32 *)&core->flags);
2162 if (!d)
2163 goto err_out;
2164
2165 d = debugfs_create_u32("clk_prepare_count", S_IRUGO, core->dentry,
2166 (u32 *)&core->prepare_count);
2167 if (!d)
2168 goto err_out;
2169
2170 d = debugfs_create_u32("clk_enable_count", S_IRUGO, core->dentry,
2171 (u32 *)&core->enable_count);
2172 if (!d)
2173 goto err_out;
2174
2175 d = debugfs_create_u32("clk_notifier_count", S_IRUGO, core->dentry,
2176 (u32 *)&core->notifier_count);
2177 if (!d)
2178 goto err_out;
2179
2180 if (core->ops->debug_init) {
2181 ret = core->ops->debug_init(core->hw, core->dentry);
2182 if (ret)
2183 goto err_out;
2184 }
2185
2186 ret = 0;
2187 goto out;
2188
2189err_out:
2190 debugfs_remove_recursive(core->dentry);
2191 core->dentry = NULL;
2192out:
2193 return ret;
2194}
2195
2196/**
2197 * clk_debug_register - add a clk node to the debugfs clk directory
2198 * @core: the clk being added to the debugfs clk directory
2199 *
2200 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
2201 * initialized. Otherwise it bails out early since the debugfs clk directory
2202 * will be created lazily by clk_debug_init as part of a late_initcall.
2203 */
2204static int clk_debug_register(struct clk_core *core)
2205{
2206 int ret = 0;
2207
2208 mutex_lock(&clk_debug_lock);
2209 hlist_add_head(&core->debug_node, &clk_debug_list);
2210
2211 if (!inited)
2212 goto unlock;
2213
2214 ret = clk_debug_create_one(core, rootdir);
2215unlock:
2216 mutex_unlock(&clk_debug_lock);
2217
2218 return ret;
2219}
2220
2221 /**
2222 * clk_debug_unregister - remove a clk node from the debugfs clk directory
2223 * @core: the clk being removed from the debugfs clk directory
2224 *
2225 * Dynamically removes a clk and all its child nodes from the
2226 * debugfs clk directory if clk->dentry points to debugfs created by
2227 * clk_debug_register in __clk_core_init.
2228 */
2229static void clk_debug_unregister(struct clk_core *core)
2230{
2231 mutex_lock(&clk_debug_lock);
2232 hlist_del_init(&core->debug_node);
2233 debugfs_remove_recursive(core->dentry);
2234 core->dentry = NULL;
2235 mutex_unlock(&clk_debug_lock);
2236}
2237
2238struct dentry *clk_debugfs_add_file(struct clk_hw *hw, char *name, umode_t mode,
2239 void *data, const struct file_operations *fops)
2240{
2241 struct dentry *d = NULL;
2242
2243 if (hw->core->dentry)
2244 d = debugfs_create_file(name, mode, hw->core->dentry, data,
2245 fops);
2246
2247 return d;
2248}
2249EXPORT_SYMBOL_GPL(clk_debugfs_add_file);
2250
2251/**
2252 * clk_debug_init - lazily populate the debugfs clk directory
2253 *
2254 * clks are often initialized very early during boot before memory can be
2255 * dynamically allocated and well before debugfs is setup. This function
2256 * populates the debugfs clk directory once at boot-time when we know that
2257 * debugfs is setup. It should only be called once at boot-time, all other clks
2258 * added dynamically will be done so with clk_debug_register.
2259 */
2260static int __init clk_debug_init(void)
2261{
2262 struct clk_core *core;
2263 struct dentry *d;
2264
2265 rootdir = debugfs_create_dir("clk", NULL);
2266
2267 if (!rootdir)
2268 return -ENOMEM;
2269
2270 d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists,
2271 &clk_summary_fops);
2272 if (!d)
2273 return -ENOMEM;
2274
2275 d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists,
2276 &clk_dump_fops);
2277 if (!d)
2278 return -ENOMEM;
2279
2280 d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir,
2281 &orphan_list, &clk_summary_fops);
2282 if (!d)
2283 return -ENOMEM;
2284
2285 d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir,
2286 &orphan_list, &clk_dump_fops);
2287 if (!d)
2288 return -ENOMEM;
2289
2290 mutex_lock(&clk_debug_lock);
2291 hlist_for_each_entry(core, &clk_debug_list, debug_node)
2292 clk_debug_create_one(core, rootdir);
2293
2294 inited = 1;
2295 mutex_unlock(&clk_debug_lock);
2296
2297 return 0;
2298}
2299late_initcall(clk_debug_init);
2300#else
2301static inline int clk_debug_register(struct clk_core *core) { return 0; }
2302static inline void clk_debug_reparent(struct clk_core *core,
2303 struct clk_core *new_parent)
2304{
2305}
2306static inline void clk_debug_unregister(struct clk_core *core)
2307{
2308}
2309#endif
2310
2311/**
2312 * __clk_core_init - initialize the data structures in a struct clk_core
2313 * @core: clk_core being initialized
2314 *
2315 * Initializes the lists in struct clk_core, queries the hardware for the
2316 * parent and rate and sets them both.
2317 */
2318static int __clk_core_init(struct clk_core *core)
2319{
2320 int i, ret = 0;
2321 struct clk_core *orphan;
2322 struct hlist_node *tmp2;
2323 unsigned long rate;
2324
2325 if (!core)
2326 return -EINVAL;
2327
2328 clk_prepare_lock();
2329
2330 /* check to see if a clock with this name is already registered */
2331 if (clk_core_lookup(core->name)) {
2332 pr_debug("%s: clk %s already initialized\n",
2333 __func__, core->name);
2334 ret = -EEXIST;
2335 goto out;
2336 }
2337
2338 /* check that clk_ops are sane. See Documentation/clk.txt */
2339 if (core->ops->set_rate &&
2340 !((core->ops->round_rate || core->ops->determine_rate) &&
2341 core->ops->recalc_rate)) {
2342 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
2343 __func__, core->name);
2344 ret = -EINVAL;
2345 goto out;
2346 }
2347
2348 if (core->ops->set_parent && !core->ops->get_parent) {
2349 pr_err("%s: %s must implement .get_parent & .set_parent\n",
2350 __func__, core->name);
2351 ret = -EINVAL;
2352 goto out;
2353 }
2354
2355 if (core->num_parents > 1 && !core->ops->get_parent) {
2356 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
2357 __func__, core->name);
2358 ret = -EINVAL;
2359 goto out;
2360 }
2361
2362 if (core->ops->set_rate_and_parent &&
2363 !(core->ops->set_parent && core->ops->set_rate)) {
2364 pr_err("%s: %s must implement .set_parent & .set_rate\n",
2365 __func__, core->name);
2366 ret = -EINVAL;
2367 goto out;
2368 }
2369
2370 /* throw a WARN if any entries in parent_names are NULL */
2371 for (i = 0; i < core->num_parents; i++)
2372 WARN(!core->parent_names[i],
2373 "%s: invalid NULL in %s's .parent_names\n",
2374 __func__, core->name);
2375
2376 core->parent = __clk_init_parent(core);
2377
2378 /*
2379 * Populate core->parent if parent has already been clk_core_init'd. If
2380 * parent has not yet been clk_core_init'd then place clk in the orphan
2381 * list. If clk doesn't have any parents then place it in the root
2382 * clk list.
2383 *
2384 * Every time a new clk is clk_init'd then we walk the list of orphan
2385 * clocks and re-parent any that are children of the clock currently
2386 * being clk_init'd.
2387 */
2388 if (core->parent) {
2389 hlist_add_head(&core->child_node,
2390 &core->parent->children);
2391 core->orphan = core->parent->orphan;
2392 } else if (!core->num_parents) {
2393 hlist_add_head(&core->child_node, &clk_root_list);
2394 core->orphan = false;
2395 } else {
2396 hlist_add_head(&core->child_node, &clk_orphan_list);
2397 core->orphan = true;
2398 }
2399
2400 /*
2401 * Set clk's accuracy. The preferred method is to use
2402 * .recalc_accuracy. For simple clocks and lazy developers the default
2403 * fallback is to use the parent's accuracy. If a clock doesn't have a
2404 * parent (or is orphaned) then accuracy is set to zero (perfect
2405 * clock).
2406 */
2407 if (core->ops->recalc_accuracy)
2408 core->accuracy = core->ops->recalc_accuracy(core->hw,
2409 __clk_get_accuracy(core->parent));
2410 else if (core->parent)
2411 core->accuracy = core->parent->accuracy;
2412 else
2413 core->accuracy = 0;
2414
2415 /*
2416 * Set clk's phase.
2417 * Since a phase is by definition relative to its parent, just
2418 * query the current clock phase, or just assume it's in phase.
2419 */
2420 if (core->ops->get_phase)
2421 core->phase = core->ops->get_phase(core->hw);
2422 else
2423 core->phase = 0;
2424
2425 /*
2426 * Set clk's rate. The preferred method is to use .recalc_rate. For
2427 * simple clocks and lazy developers the default fallback is to use the
2428 * parent's rate. If a clock doesn't have a parent (or is orphaned)
2429 * then rate is set to zero.
2430 */
2431 if (core->ops->recalc_rate)
2432 rate = core->ops->recalc_rate(core->hw,
2433 clk_core_get_rate_nolock(core->parent));
2434 else if (core->parent)
2435 rate = core->parent->rate;
2436 else
2437 rate = 0;
2438 core->rate = core->req_rate = rate;
2439
2440 /*
2441 * walk the list of orphan clocks and reparent any that newly finds a
2442 * parent.
2443 */
2444 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
2445 struct clk_core *parent = __clk_init_parent(orphan);
2446
2447 /*
2448 * we could call __clk_set_parent, but that would result in a
2449 * redundant call to the .set_rate op, if it exists
2450 */
2451 if (parent) {
2452 __clk_set_parent_before(orphan, parent);
2453 __clk_set_parent_after(orphan, parent, NULL);
2454 __clk_recalc_accuracies(orphan);
2455 __clk_recalc_rates(orphan, 0);
2456 }
2457 }
2458
2459 /*
2460 * optional platform-specific magic
2461 *
2462 * The .init callback is not used by any of the basic clock types, but
2463 * exists for weird hardware that must perform initialization magic.
2464 * Please consider other ways of solving initialization problems before
2465 * using this callback, as its use is discouraged.
2466 */
2467 if (core->ops->init)
2468 core->ops->init(core->hw);
2469
2470 if (core->flags & CLK_IS_CRITICAL) {
2471 unsigned long flags;
2472
2473 clk_core_prepare(core);
2474
2475 flags = clk_enable_lock();
2476 clk_core_enable(core);
2477 clk_enable_unlock(flags);
2478 }
2479
2480 kref_init(&core->ref);
2481out:
2482 clk_prepare_unlock();
2483
2484 if (!ret)
2485 clk_debug_register(core);
2486
2487 return ret;
2488}
2489
2490struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,
2491 const char *con_id)
2492{
2493 struct clk *clk;
2494
2495 /* This is to allow this function to be chained to others */
2496 if (IS_ERR_OR_NULL(hw))
2497 return ERR_CAST(hw);
2498
2499 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
2500 if (!clk)
2501 return ERR_PTR(-ENOMEM);
2502
2503 clk->core = hw->core;
2504 clk->dev_id = dev_id;
2505 clk->con_id = con_id;
2506 clk->max_rate = ULONG_MAX;
2507
2508 clk_prepare_lock();
2509 hlist_add_head(&clk->clks_node, &hw->core->clks);
2510 clk_prepare_unlock();
2511
2512 return clk;
2513}
2514
2515void __clk_free_clk(struct clk *clk)
2516{
2517 clk_prepare_lock();
2518 hlist_del(&clk->clks_node);
2519 clk_prepare_unlock();
2520
2521 kfree(clk);
2522}
2523
2524/**
2525 * clk_register - allocate a new clock, register it and return an opaque cookie
2526 * @dev: device that is registering this clock
2527 * @hw: link to hardware-specific clock data
2528 *
2529 * clk_register is the primary interface for populating the clock tree with new
2530 * clock nodes. It returns a pointer to the newly allocated struct clk which
2531 * cannot be dereferenced by driver code but may be used in conjunction with the
2532 * rest of the clock API. In the event of an error clk_register will return an
2533 * error code; drivers must test for an error code after calling clk_register.
2534 */
2535struct clk *clk_register(struct device *dev, struct clk_hw *hw)
2536{
2537 int i, ret;
2538 struct clk_core *core;
2539
2540 core = kzalloc(sizeof(*core), GFP_KERNEL);
2541 if (!core) {
2542 ret = -ENOMEM;
2543 goto fail_out;
2544 }
2545
2546 core->name = kstrdup_const(hw->init->name, GFP_KERNEL);
2547 if (!core->name) {
2548 ret = -ENOMEM;
2549 goto fail_name;
2550 }
2551 core->ops = hw->init->ops;
2552 if (dev && dev->driver)
2553 core->owner = dev->driver->owner;
2554 core->hw = hw;
2555 core->flags = hw->init->flags;
2556 core->num_parents = hw->init->num_parents;
2557 core->min_rate = 0;
2558 core->max_rate = ULONG_MAX;
2559 hw->core = core;
2560
2561 /* allocate local copy in case parent_names is __initdata */
2562 core->parent_names = kcalloc(core->num_parents, sizeof(char *),
2563 GFP_KERNEL);
2564
2565 if (!core->parent_names) {
2566 ret = -ENOMEM;
2567 goto fail_parent_names;
2568 }
2569
2570
2571 /* copy each string name in case parent_names is __initdata */
2572 for (i = 0; i < core->num_parents; i++) {
2573 core->parent_names[i] = kstrdup_const(hw->init->parent_names[i],
2574 GFP_KERNEL);
2575 if (!core->parent_names[i]) {
2576 ret = -ENOMEM;
2577 goto fail_parent_names_copy;
2578 }
2579 }
2580
2581 /* avoid unnecessary string look-ups of clk_core's possible parents. */
2582 core->parents = kcalloc(core->num_parents, sizeof(*core->parents),
2583 GFP_KERNEL);
2584 if (!core->parents) {
2585 ret = -ENOMEM;
2586 goto fail_parents;
2587 };
2588
2589 INIT_HLIST_HEAD(&core->clks);
2590
2591 hw->clk = __clk_create_clk(hw, NULL, NULL);
2592 if (IS_ERR(hw->clk)) {
2593 ret = PTR_ERR(hw->clk);
2594 goto fail_parents;
2595 }
2596
2597 ret = __clk_core_init(core);
2598 if (!ret)
2599 return hw->clk;
2600
2601 __clk_free_clk(hw->clk);
2602 hw->clk = NULL;
2603
2604fail_parents:
2605 kfree(core->parents);
2606fail_parent_names_copy:
2607 while (--i >= 0)
2608 kfree_const(core->parent_names[i]);
2609 kfree(core->parent_names);
2610fail_parent_names:
2611 kfree_const(core->name);
2612fail_name:
2613 kfree(core);
2614fail_out:
2615 return ERR_PTR(ret);
2616}
2617EXPORT_SYMBOL_GPL(clk_register);
2618
2619/**
2620 * clk_hw_register - register a clk_hw and return an error code
2621 * @dev: device that is registering this clock
2622 * @hw: link to hardware-specific clock data
2623 *
2624 * clk_hw_register is the primary interface for populating the clock tree with
2625 * new clock nodes. It returns an integer equal to zero indicating success or
2626 * less than zero indicating failure. Drivers must test for an error code after
2627 * calling clk_hw_register().
2628 */
2629int clk_hw_register(struct device *dev, struct clk_hw *hw)
2630{
2631 return PTR_ERR_OR_ZERO(clk_register(dev, hw));
2632}
2633EXPORT_SYMBOL_GPL(clk_hw_register);
2634
2635/* Free memory allocated for a clock. */
2636static void __clk_release(struct kref *ref)
2637{
2638 struct clk_core *core = container_of(ref, struct clk_core, ref);
2639 int i = core->num_parents;
2640
2641 lockdep_assert_held(&prepare_lock);
2642
2643 kfree(core->parents);
2644 while (--i >= 0)
2645 kfree_const(core->parent_names[i]);
2646
2647 kfree(core->parent_names);
2648 kfree_const(core->name);
2649 kfree(core);
2650}
2651
2652/*
2653 * Empty clk_ops for unregistered clocks. These are used temporarily
2654 * after clk_unregister() was called on a clock and until last clock
2655 * consumer calls clk_put() and the struct clk object is freed.
2656 */
2657static int clk_nodrv_prepare_enable(struct clk_hw *hw)
2658{
2659 return -ENXIO;
2660}
2661
2662static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
2663{
2664 WARN_ON_ONCE(1);
2665}
2666
2667static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
2668 unsigned long parent_rate)
2669{
2670 return -ENXIO;
2671}
2672
2673static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
2674{
2675 return -ENXIO;
2676}
2677
2678static const struct clk_ops clk_nodrv_ops = {
2679 .enable = clk_nodrv_prepare_enable,
2680 .disable = clk_nodrv_disable_unprepare,
2681 .prepare = clk_nodrv_prepare_enable,
2682 .unprepare = clk_nodrv_disable_unprepare,
2683 .set_rate = clk_nodrv_set_rate,
2684 .set_parent = clk_nodrv_set_parent,
2685};
2686
2687/**
2688 * clk_unregister - unregister a currently registered clock
2689 * @clk: clock to unregister
2690 */
2691void clk_unregister(struct clk *clk)
2692{
2693 unsigned long flags;
2694
2695 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2696 return;
2697
2698 clk_debug_unregister(clk->core);
2699
2700 clk_prepare_lock();
2701
2702 if (clk->core->ops == &clk_nodrv_ops) {
2703 pr_err("%s: unregistered clock: %s\n", __func__,
2704 clk->core->name);
2705 goto unlock;
2706 }
2707 /*
2708 * Assign empty clock ops for consumers that might still hold
2709 * a reference to this clock.
2710 */
2711 flags = clk_enable_lock();
2712 clk->core->ops = &clk_nodrv_ops;
2713 clk_enable_unlock(flags);
2714
2715 if (!hlist_empty(&clk->core->children)) {
2716 struct clk_core *child;
2717 struct hlist_node *t;
2718
2719 /* Reparent all children to the orphan list. */
2720 hlist_for_each_entry_safe(child, t, &clk->core->children,
2721 child_node)
2722 clk_core_set_parent(child, NULL);
2723 }
2724
2725 hlist_del_init(&clk->core->child_node);
2726
2727 if (clk->core->prepare_count)
2728 pr_warn("%s: unregistering prepared clock: %s\n",
2729 __func__, clk->core->name);
2730 kref_put(&clk->core->ref, __clk_release);
2731unlock:
2732 clk_prepare_unlock();
2733}
2734EXPORT_SYMBOL_GPL(clk_unregister);
2735
2736/**
2737 * clk_hw_unregister - unregister a currently registered clk_hw
2738 * @hw: hardware-specific clock data to unregister
2739 */
2740void clk_hw_unregister(struct clk_hw *hw)
2741{
2742 clk_unregister(hw->clk);
2743}
2744EXPORT_SYMBOL_GPL(clk_hw_unregister);
2745
2746static void devm_clk_release(struct device *dev, void *res)
2747{
2748 clk_unregister(*(struct clk **)res);
2749}
2750
2751static void devm_clk_hw_release(struct device *dev, void *res)
2752{
2753 clk_hw_unregister(*(struct clk_hw **)res);
2754}
2755
2756/**
2757 * devm_clk_register - resource managed clk_register()
2758 * @dev: device that is registering this clock
2759 * @hw: link to hardware-specific clock data
2760 *
2761 * Managed clk_register(). Clocks returned from this function are
2762 * automatically clk_unregister()ed on driver detach. See clk_register() for
2763 * more information.
2764 */
2765struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
2766{
2767 struct clk *clk;
2768 struct clk **clkp;
2769
2770 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
2771 if (!clkp)
2772 return ERR_PTR(-ENOMEM);
2773
2774 clk = clk_register(dev, hw);
2775 if (!IS_ERR(clk)) {
2776 *clkp = clk;
2777 devres_add(dev, clkp);
2778 } else {
2779 devres_free(clkp);
2780 }
2781
2782 return clk;
2783}
2784EXPORT_SYMBOL_GPL(devm_clk_register);
2785
2786/**
2787 * devm_clk_hw_register - resource managed clk_hw_register()
2788 * @dev: device that is registering this clock
2789 * @hw: link to hardware-specific clock data
2790 *
2791 * Managed clk_hw_register(). Clocks registered by this function are
2792 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
2793 * for more information.
2794 */
2795int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
2796{
2797 struct clk_hw **hwp;
2798 int ret;
2799
2800 hwp = devres_alloc(devm_clk_hw_release, sizeof(*hwp), GFP_KERNEL);
2801 if (!hwp)
2802 return -ENOMEM;
2803
2804 ret = clk_hw_register(dev, hw);
2805 if (!ret) {
2806 *hwp = hw;
2807 devres_add(dev, hwp);
2808 } else {
2809 devres_free(hwp);
2810 }
2811
2812 return ret;
2813}
2814EXPORT_SYMBOL_GPL(devm_clk_hw_register);
2815
2816static int devm_clk_match(struct device *dev, void *res, void *data)
2817{
2818 struct clk *c = res;
2819 if (WARN_ON(!c))
2820 return 0;
2821 return c == data;
2822}
2823
2824static int devm_clk_hw_match(struct device *dev, void *res, void *data)
2825{
2826 struct clk_hw *hw = res;
2827
2828 if (WARN_ON(!hw))
2829 return 0;
2830 return hw == data;
2831}
2832
2833/**
2834 * devm_clk_unregister - resource managed clk_unregister()
2835 * @clk: clock to unregister
2836 *
2837 * Deallocate a clock allocated with devm_clk_register(). Normally
2838 * this function will not need to be called and the resource management
2839 * code will ensure that the resource is freed.
2840 */
2841void devm_clk_unregister(struct device *dev, struct clk *clk)
2842{
2843 WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
2844}
2845EXPORT_SYMBOL_GPL(devm_clk_unregister);
2846
2847/**
2848 * devm_clk_hw_unregister - resource managed clk_hw_unregister()
2849 * @dev: device that is unregistering the hardware-specific clock data
2850 * @hw: link to hardware-specific clock data
2851 *
2852 * Unregister a clk_hw registered with devm_clk_hw_register(). Normally
2853 * this function will not need to be called and the resource management
2854 * code will ensure that the resource is freed.
2855 */
2856void devm_clk_hw_unregister(struct device *dev, struct clk_hw *hw)
2857{
2858 WARN_ON(devres_release(dev, devm_clk_hw_release, devm_clk_hw_match,
2859 hw));
2860}
2861EXPORT_SYMBOL_GPL(devm_clk_hw_unregister);
2862
2863/*
2864 * clkdev helpers
2865 */
2866int __clk_get(struct clk *clk)
2867{
2868 struct clk_core *core = !clk ? NULL : clk->core;
2869
2870 if (core) {
2871 if (!try_module_get(core->owner))
2872 return 0;
2873
2874 kref_get(&core->ref);
2875 }
2876 return 1;
2877}
2878
2879void __clk_put(struct clk *clk)
2880{
2881 struct module *owner;
2882
2883 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2884 return;
2885
2886 clk_prepare_lock();
2887
2888 hlist_del(&clk->clks_node);
2889 if (clk->min_rate > clk->core->req_rate ||
2890 clk->max_rate < clk->core->req_rate)
2891 clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
2892
2893 owner = clk->core->owner;
2894 kref_put(&clk->core->ref, __clk_release);
2895
2896 clk_prepare_unlock();
2897
2898 module_put(owner);
2899
2900 kfree(clk);
2901}
2902
2903/*** clk rate change notifiers ***/
2904
2905/**
2906 * clk_notifier_register - add a clk rate change notifier
2907 * @clk: struct clk * to watch
2908 * @nb: struct notifier_block * with callback info
2909 *
2910 * Request notification when clk's rate changes. This uses an SRCU
2911 * notifier because we want it to block and notifier unregistrations are
2912 * uncommon. The callbacks associated with the notifier must not
2913 * re-enter into the clk framework by calling any top-level clk APIs;
2914 * this will cause a nested prepare_lock mutex.
2915 *
2916 * In all notification cases (pre, post and abort rate change) the original
2917 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
2918 * and the new frequency is passed via struct clk_notifier_data.new_rate.
2919 *
2920 * clk_notifier_register() must be called from non-atomic context.
2921 * Returns -EINVAL if called with null arguments, -ENOMEM upon
2922 * allocation failure; otherwise, passes along the return value of
2923 * srcu_notifier_chain_register().
2924 */
2925int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
2926{
2927 struct clk_notifier *cn;
2928 int ret = -ENOMEM;
2929
2930 if (!clk || !nb)
2931 return -EINVAL;
2932
2933 clk_prepare_lock();
2934
2935 /* search the list of notifiers for this clk */
2936 list_for_each_entry(cn, &clk_notifier_list, node)
2937 if (cn->clk == clk)
2938 break;
2939
2940 /* if clk wasn't in the notifier list, allocate new clk_notifier */
2941 if (cn->clk != clk) {
2942 cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL);
2943 if (!cn)
2944 goto out;
2945
2946 cn->clk = clk;
2947 srcu_init_notifier_head(&cn->notifier_head);
2948
2949 list_add(&cn->node, &clk_notifier_list);
2950 }
2951
2952 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
2953
2954 clk->core->notifier_count++;
2955
2956out:
2957 clk_prepare_unlock();
2958
2959 return ret;
2960}
2961EXPORT_SYMBOL_GPL(clk_notifier_register);
2962
2963/**
2964 * clk_notifier_unregister - remove a clk rate change notifier
2965 * @clk: struct clk *
2966 * @nb: struct notifier_block * with callback info
2967 *
2968 * Request no further notification for changes to 'clk' and frees memory
2969 * allocated in clk_notifier_register.
2970 *
2971 * Returns -EINVAL if called with null arguments; otherwise, passes
2972 * along the return value of srcu_notifier_chain_unregister().
2973 */
2974int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
2975{
2976 struct clk_notifier *cn = NULL;
2977 int ret = -EINVAL;
2978
2979 if (!clk || !nb)
2980 return -EINVAL;
2981
2982 clk_prepare_lock();
2983
2984 list_for_each_entry(cn, &clk_notifier_list, node)
2985 if (cn->clk == clk)
2986 break;
2987
2988 if (cn->clk == clk) {
2989 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
2990
2991 clk->core->notifier_count--;
2992
2993 /* XXX the notifier code should handle this better */
2994 if (!cn->notifier_head.head) {
2995 srcu_cleanup_notifier_head(&cn->notifier_head);
2996 list_del(&cn->node);
2997 kfree(cn);
2998 }
2999
3000 } else {
3001 ret = -ENOENT;
3002 }
3003
3004 clk_prepare_unlock();
3005
3006 return ret;
3007}
3008EXPORT_SYMBOL_GPL(clk_notifier_unregister);
3009
3010#ifdef CONFIG_OF
3011/**
3012 * struct of_clk_provider - Clock provider registration structure
3013 * @link: Entry in global list of clock providers
3014 * @node: Pointer to device tree node of clock provider
3015 * @get: Get clock callback. Returns NULL or a struct clk for the
3016 * given clock specifier
3017 * @data: context pointer to be passed into @get callback
3018 */
3019struct of_clk_provider {
3020 struct list_head link;
3021
3022 struct device_node *node;
3023 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
3024 struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
3025 void *data;
3026};
3027
3028static const struct of_device_id __clk_of_table_sentinel
3029 __used __section(__clk_of_table_end);
3030
3031static LIST_HEAD(of_clk_providers);
3032static DEFINE_MUTEX(of_clk_mutex);
3033
3034struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
3035 void *data)
3036{
3037 return data;
3038}
3039EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
3040
3041struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
3042{
3043 return data;
3044}
3045EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
3046
3047struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
3048{
3049 struct clk_onecell_data *clk_data = data;
3050 unsigned int idx = clkspec->args[0];
3051
3052 if (idx >= clk_data->clk_num) {
3053 pr_err("%s: invalid clock index %u\n", __func__, idx);
3054 return ERR_PTR(-EINVAL);
3055 }
3056
3057 return clk_data->clks[idx];
3058}
3059EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
3060
3061struct clk_hw *
3062of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
3063{
3064 struct clk_hw_onecell_data *hw_data = data;
3065 unsigned int idx = clkspec->args[0];
3066
3067 if (idx >= hw_data->num) {
3068 pr_err("%s: invalid index %u\n", __func__, idx);
3069 return ERR_PTR(-EINVAL);
3070 }
3071
3072 return hw_data->hws[idx];
3073}
3074EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
3075
3076/**
3077 * of_clk_add_provider() - Register a clock provider for a node
3078 * @np: Device node pointer associated with clock provider
3079 * @clk_src_get: callback for decoding clock
3080 * @data: context pointer for @clk_src_get callback.
3081 */
3082int of_clk_add_provider(struct device_node *np,
3083 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
3084 void *data),
3085 void *data)
3086{
3087 struct of_clk_provider *cp;
3088 int ret;
3089
3090 cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL);
3091 if (!cp)
3092 return -ENOMEM;
3093
3094 cp->node = of_node_get(np);
3095 cp->data = data;
3096 cp->get = clk_src_get;
3097
3098 mutex_lock(&of_clk_mutex);
3099 list_add(&cp->link, &of_clk_providers);
3100 mutex_unlock(&of_clk_mutex);
3101 pr_debug("Added clock from %s\n", np->full_name);
3102
3103 ret = of_clk_set_defaults(np, true);
3104 if (ret < 0)
3105 of_clk_del_provider(np);
3106
3107 return ret;
3108}
3109EXPORT_SYMBOL_GPL(of_clk_add_provider);
3110
3111/**
3112 * of_clk_add_hw_provider() - Register a clock provider for a node
3113 * @np: Device node pointer associated with clock provider
3114 * @get: callback for decoding clk_hw
3115 * @data: context pointer for @get callback.
3116 */
3117int of_clk_add_hw_provider(struct device_node *np,
3118 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
3119 void *data),
3120 void *data)
3121{
3122 struct of_clk_provider *cp;
3123 int ret;
3124
3125 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
3126 if (!cp)
3127 return -ENOMEM;
3128
3129 cp->node = of_node_get(np);
3130 cp->data = data;
3131 cp->get_hw = get;
3132
3133 mutex_lock(&of_clk_mutex);
3134 list_add(&cp->link, &of_clk_providers);
3135 mutex_unlock(&of_clk_mutex);
3136 pr_debug("Added clk_hw provider from %s\n", np->full_name);
3137
3138 ret = of_clk_set_defaults(np, true);
3139 if (ret < 0)
3140 of_clk_del_provider(np);
3141
3142 return ret;
3143}
3144EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
3145
3146/**
3147 * of_clk_del_provider() - Remove a previously registered clock provider
3148 * @np: Device node pointer associated with clock provider
3149 */
3150void of_clk_del_provider(struct device_node *np)
3151{
3152 struct of_clk_provider *cp;
3153
3154 mutex_lock(&of_clk_mutex);
3155 list_for_each_entry(cp, &of_clk_providers, link) {
3156 if (cp->node == np) {
3157 list_del(&cp->link);
3158 of_node_put(cp->node);
3159 kfree(cp);
3160 break;
3161 }
3162 }
3163 mutex_unlock(&of_clk_mutex);
3164}
3165EXPORT_SYMBOL_GPL(of_clk_del_provider);
3166
3167static struct clk_hw *
3168__of_clk_get_hw_from_provider(struct of_clk_provider *provider,
3169 struct of_phandle_args *clkspec)
3170{
3171 struct clk *clk;
3172
3173 if (provider->get_hw)
3174 return provider->get_hw(clkspec, provider->data);
3175
3176 clk = provider->get(clkspec, provider->data);
3177 if (IS_ERR(clk))
3178 return ERR_CAST(clk);
3179 return __clk_get_hw(clk);
3180}
3181
3182struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec,
3183 const char *dev_id, const char *con_id)
3184{
3185 struct of_clk_provider *provider;
3186 struct clk *clk = ERR_PTR(-EPROBE_DEFER);
3187 struct clk_hw *hw;
3188
3189 if (!clkspec)
3190 return ERR_PTR(-EINVAL);
3191
3192 /* Check if we have such a provider in our array */
3193 mutex_lock(&of_clk_mutex);
3194 list_for_each_entry(provider, &of_clk_providers, link) {
3195 if (provider->node == clkspec->np) {
3196 hw = __of_clk_get_hw_from_provider(provider, clkspec);
3197 clk = __clk_create_clk(hw, dev_id, con_id);
3198 }
3199
3200 if (!IS_ERR(clk)) {
3201 if (!__clk_get(clk)) {
3202 __clk_free_clk(clk);
3203 clk = ERR_PTR(-ENOENT);
3204 }
3205
3206 break;
3207 }
3208 }
3209 mutex_unlock(&of_clk_mutex);
3210
3211 return clk;
3212}
3213
3214/**
3215 * of_clk_get_from_provider() - Lookup a clock from a clock provider
3216 * @clkspec: pointer to a clock specifier data structure
3217 *
3218 * This function looks up a struct clk from the registered list of clock
3219 * providers, an input is a clock specifier data structure as returned
3220 * from the of_parse_phandle_with_args() function call.
3221 */
3222struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
3223{
3224 return __of_clk_get_from_provider(clkspec, NULL, __func__);
3225}
3226EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
3227
3228/**
3229 * of_clk_get_parent_count() - Count the number of clocks a device node has
3230 * @np: device node to count
3231 *
3232 * Returns: The number of clocks that are possible parents of this node
3233 */
3234unsigned int of_clk_get_parent_count(struct device_node *np)
3235{
3236 int count;
3237
3238 count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
3239 if (count < 0)
3240 return 0;
3241
3242 return count;
3243}
3244EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
3245
3246const char *of_clk_get_parent_name(struct device_node *np, int index)
3247{
3248 struct of_phandle_args clkspec;
3249 struct property *prop;
3250 const char *clk_name;
3251 const __be32 *vp;
3252 u32 pv;
3253 int rc;
3254 int count;
3255 struct clk *clk;
3256
3257 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
3258 &clkspec);
3259 if (rc)
3260 return NULL;
3261
3262 index = clkspec.args_count ? clkspec.args[0] : 0;
3263 count = 0;
3264
3265 /* if there is an indices property, use it to transfer the index
3266 * specified into an array offset for the clock-output-names property.
3267 */
3268 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
3269 if (index == pv) {
3270 index = count;
3271 break;
3272 }
3273 count++;
3274 }
3275 /* We went off the end of 'clock-indices' without finding it */
3276 if (prop && !vp)
3277 return NULL;
3278
3279 if (of_property_read_string_index(clkspec.np, "clock-output-names",
3280 index,
3281 &clk_name) < 0) {
3282 /*
3283 * Best effort to get the name if the clock has been
3284 * registered with the framework. If the clock isn't
3285 * registered, we return the node name as the name of
3286 * the clock as long as #clock-cells = 0.
3287 */
3288 clk = of_clk_get_from_provider(&clkspec);
3289 if (IS_ERR(clk)) {
3290 if (clkspec.args_count == 0)
3291 clk_name = clkspec.np->name;
3292 else
3293 clk_name = NULL;
3294 } else {
3295 clk_name = __clk_get_name(clk);
3296 clk_put(clk);
3297 }
3298 }
3299
3300
3301 of_node_put(clkspec.np);
3302 return clk_name;
3303}
3304EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
3305
3306/**
3307 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
3308 * number of parents
3309 * @np: Device node pointer associated with clock provider
3310 * @parents: pointer to char array that hold the parents' names
3311 * @size: size of the @parents array
3312 *
3313 * Return: number of parents for the clock node.
3314 */
3315int of_clk_parent_fill(struct device_node *np, const char **parents,
3316 unsigned int size)
3317{
3318 unsigned int i = 0;
3319
3320 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
3321 i++;
3322
3323 return i;
3324}
3325EXPORT_SYMBOL_GPL(of_clk_parent_fill);
3326
3327struct clock_provider {
3328 of_clk_init_cb_t clk_init_cb;
3329 struct device_node *np;
3330 struct list_head node;
3331};
3332
3333/*
3334 * This function looks for a parent clock. If there is one, then it
3335 * checks that the provider for this parent clock was initialized, in
3336 * this case the parent clock will be ready.
3337 */
3338static int parent_ready(struct device_node *np)
3339{
3340 int i = 0;
3341
3342 while (true) {
3343 struct clk *clk = of_clk_get(np, i);
3344
3345 /* this parent is ready we can check the next one */
3346 if (!IS_ERR(clk)) {
3347 clk_put(clk);
3348 i++;
3349 continue;
3350 }
3351
3352 /* at least one parent is not ready, we exit now */
3353 if (PTR_ERR(clk) == -EPROBE_DEFER)
3354 return 0;
3355
3356 /*
3357 * Here we make assumption that the device tree is
3358 * written correctly. So an error means that there is
3359 * no more parent. As we didn't exit yet, then the
3360 * previous parent are ready. If there is no clock
3361 * parent, no need to wait for them, then we can
3362 * consider their absence as being ready
3363 */
3364 return 1;
3365 }
3366}
3367
3368/**
3369 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
3370 * @np: Device node pointer associated with clock provider
3371 * @index: clock index
3372 * @flags: pointer to clk_core->flags
3373 *
3374 * Detects if the clock-critical property exists and, if so, sets the
3375 * corresponding CLK_IS_CRITICAL flag.
3376 *
3377 * Do not use this function. It exists only for legacy Device Tree
3378 * bindings, such as the one-clock-per-node style that are outdated.
3379 * Those bindings typically put all clock data into .dts and the Linux
3380 * driver has no clock data, thus making it impossible to set this flag
3381 * correctly from the driver. Only those drivers may call
3382 * of_clk_detect_critical from their setup functions.
3383 *
3384 * Return: error code or zero on success
3385 */
3386int of_clk_detect_critical(struct device_node *np,
3387 int index, unsigned long *flags)
3388{
3389 struct property *prop;
3390 const __be32 *cur;
3391 uint32_t idx;
3392
3393 if (!np || !flags)
3394 return -EINVAL;
3395
3396 of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
3397 if (index == idx)
3398 *flags |= CLK_IS_CRITICAL;
3399
3400 return 0;
3401}
3402
3403/**
3404 * of_clk_init() - Scan and init clock providers from the DT
3405 * @matches: array of compatible values and init functions for providers.
3406 *
3407 * This function scans the device tree for matching clock providers
3408 * and calls their initialization functions. It also does it by trying
3409 * to follow the dependencies.
3410 */
3411void __init of_clk_init(const struct of_device_id *matches)
3412{
3413 const struct of_device_id *match;
3414 struct device_node *np;
3415 struct clock_provider *clk_provider, *next;
3416 bool is_init_done;
3417 bool force = false;
3418 LIST_HEAD(clk_provider_list);
3419
3420 if (!matches)
3421 matches = &__clk_of_table;
3422
3423 /* First prepare the list of the clocks providers */
3424 for_each_matching_node_and_match(np, matches, &match) {
3425 struct clock_provider *parent;
3426
3427 if (!of_device_is_available(np))
3428 continue;
3429
3430 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
3431 if (!parent) {
3432 list_for_each_entry_safe(clk_provider, next,
3433 &clk_provider_list, node) {
3434 list_del(&clk_provider->node);
3435 of_node_put(clk_provider->np);
3436 kfree(clk_provider);
3437 }
3438 of_node_put(np);
3439 return;
3440 }
3441
3442 parent->clk_init_cb = match->data;
3443 parent->np = of_node_get(np);
3444 list_add_tail(&parent->node, &clk_provider_list);
3445 }
3446
3447 while (!list_empty(&clk_provider_list)) {
3448 is_init_done = false;
3449 list_for_each_entry_safe(clk_provider, next,
3450 &clk_provider_list, node) {
3451 if (force || parent_ready(clk_provider->np)) {
3452
3453 /* Don't populate platform devices */
3454 of_node_set_flag(clk_provider->np,
3455 OF_POPULATED);
3456
3457 clk_provider->clk_init_cb(clk_provider->np);
3458 of_clk_set_defaults(clk_provider->np, true);
3459
3460 list_del(&clk_provider->node);
3461 of_node_put(clk_provider->np);
3462 kfree(clk_provider);
3463 is_init_done = true;
3464 }
3465 }
3466
3467 /*
3468 * We didn't manage to initialize any of the
3469 * remaining providers during the last loop, so now we
3470 * initialize all the remaining ones unconditionally
3471 * in case the clock parent was not mandatory
3472 */
3473 if (!is_init_done)
3474 force = true;
3475 }
3476}
3477#endif