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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// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
4 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
5 *
6 * Standard functionality for the common clock API. See Documentation/driver-api/clk.rst
7 */
8
9#include <linux/clk.h>
10#include <linux/clk-provider.h>
11#include <linux/clk/clk-conf.h>
12#include <linux/module.h>
13#include <linux/mutex.h>
14#include <linux/spinlock.h>
15#include <linux/err.h>
16#include <linux/list.h>
17#include <linux/slab.h>
18#include <linux/of.h>
19#include <linux/device.h>
20#include <linux/init.h>
21#include <linux/pm_runtime.h>
22#include <linux/sched.h>
23#include <linux/clkdev.h>
24
25#include "clk.h"
26
27static DEFINE_SPINLOCK(enable_lock);
28static DEFINE_MUTEX(prepare_lock);
29
30static struct task_struct *prepare_owner;
31static struct task_struct *enable_owner;
32
33static int prepare_refcnt;
34static int enable_refcnt;
35
36static HLIST_HEAD(clk_root_list);
37static HLIST_HEAD(clk_orphan_list);
38static LIST_HEAD(clk_notifier_list);
39
40static const struct hlist_head *all_lists[] = {
41 &clk_root_list,
42 &clk_orphan_list,
43 NULL,
44};
45
46/*** private data structures ***/
47
48struct clk_parent_map {
49 const struct clk_hw *hw;
50 struct clk_core *core;
51 const char *fw_name;
52 const char *name;
53 int index;
54};
55
56struct clk_core {
57 const char *name;
58 const struct clk_ops *ops;
59 struct clk_hw *hw;
60 struct module *owner;
61 struct device *dev;
62 struct device_node *of_node;
63 struct clk_core *parent;
64 struct clk_parent_map *parents;
65 u8 num_parents;
66 u8 new_parent_index;
67 unsigned long rate;
68 unsigned long req_rate;
69 unsigned long new_rate;
70 struct clk_core *new_parent;
71 struct clk_core *new_child;
72 unsigned long flags;
73 bool orphan;
74 bool rpm_enabled;
75 unsigned int enable_count;
76 unsigned int prepare_count;
77 unsigned int protect_count;
78 unsigned long min_rate;
79 unsigned long max_rate;
80 unsigned long accuracy;
81 int phase;
82 struct clk_duty duty;
83 struct hlist_head children;
84 struct hlist_node child_node;
85 struct hlist_head clks;
86 unsigned int notifier_count;
87#ifdef CONFIG_DEBUG_FS
88 struct dentry *dentry;
89 struct hlist_node debug_node;
90#endif
91 struct kref ref;
92};
93
94#define CREATE_TRACE_POINTS
95#include <trace/events/clk.h>
96
97struct clk {
98 struct clk_core *core;
99 struct device *dev;
100 const char *dev_id;
101 const char *con_id;
102 unsigned long min_rate;
103 unsigned long max_rate;
104 unsigned int exclusive_count;
105 struct hlist_node clks_node;
106};
107
108/*** runtime pm ***/
109static int clk_pm_runtime_get(struct clk_core *core)
110{
111 if (!core->rpm_enabled)
112 return 0;
113
114 return pm_runtime_resume_and_get(core->dev);
115}
116
117static void clk_pm_runtime_put(struct clk_core *core)
118{
119 if (!core->rpm_enabled)
120 return;
121
122 pm_runtime_put_sync(core->dev);
123}
124
125/*** locking ***/
126static void clk_prepare_lock(void)
127{
128 if (!mutex_trylock(&prepare_lock)) {
129 if (prepare_owner == current) {
130 prepare_refcnt++;
131 return;
132 }
133 mutex_lock(&prepare_lock);
134 }
135 WARN_ON_ONCE(prepare_owner != NULL);
136 WARN_ON_ONCE(prepare_refcnt != 0);
137 prepare_owner = current;
138 prepare_refcnt = 1;
139}
140
141static void clk_prepare_unlock(void)
142{
143 WARN_ON_ONCE(prepare_owner != current);
144 WARN_ON_ONCE(prepare_refcnt == 0);
145
146 if (--prepare_refcnt)
147 return;
148 prepare_owner = NULL;
149 mutex_unlock(&prepare_lock);
150}
151
152static unsigned long clk_enable_lock(void)
153 __acquires(enable_lock)
154{
155 unsigned long flags;
156
157 /*
158 * On UP systems, spin_trylock_irqsave() always returns true, even if
159 * we already hold the lock. So, in that case, we rely only on
160 * reference counting.
161 */
162 if (!IS_ENABLED(CONFIG_SMP) ||
163 !spin_trylock_irqsave(&enable_lock, flags)) {
164 if (enable_owner == current) {
165 enable_refcnt++;
166 __acquire(enable_lock);
167 if (!IS_ENABLED(CONFIG_SMP))
168 local_save_flags(flags);
169 return flags;
170 }
171 spin_lock_irqsave(&enable_lock, flags);
172 }
173 WARN_ON_ONCE(enable_owner != NULL);
174 WARN_ON_ONCE(enable_refcnt != 0);
175 enable_owner = current;
176 enable_refcnt = 1;
177 return flags;
178}
179
180static void clk_enable_unlock(unsigned long flags)
181 __releases(enable_lock)
182{
183 WARN_ON_ONCE(enable_owner != current);
184 WARN_ON_ONCE(enable_refcnt == 0);
185
186 if (--enable_refcnt) {
187 __release(enable_lock);
188 return;
189 }
190 enable_owner = NULL;
191 spin_unlock_irqrestore(&enable_lock, flags);
192}
193
194static bool clk_core_rate_is_protected(struct clk_core *core)
195{
196 return core->protect_count;
197}
198
199static bool clk_core_is_prepared(struct clk_core *core)
200{
201 bool ret = false;
202
203 /*
204 * .is_prepared is optional for clocks that can prepare
205 * fall back to software usage counter if it is missing
206 */
207 if (!core->ops->is_prepared)
208 return core->prepare_count;
209
210 if (!clk_pm_runtime_get(core)) {
211 ret = core->ops->is_prepared(core->hw);
212 clk_pm_runtime_put(core);
213 }
214
215 return ret;
216}
217
218static bool clk_core_is_enabled(struct clk_core *core)
219{
220 bool ret = false;
221
222 /*
223 * .is_enabled is only mandatory for clocks that gate
224 * fall back to software usage counter if .is_enabled is missing
225 */
226 if (!core->ops->is_enabled)
227 return core->enable_count;
228
229 /*
230 * Check if clock controller's device is runtime active before
231 * calling .is_enabled callback. If not, assume that clock is
232 * disabled, because we might be called from atomic context, from
233 * which pm_runtime_get() is not allowed.
234 * This function is called mainly from clk_disable_unused_subtree,
235 * which ensures proper runtime pm activation of controller before
236 * taking enable spinlock, but the below check is needed if one tries
237 * to call it from other places.
238 */
239 if (core->rpm_enabled) {
240 pm_runtime_get_noresume(core->dev);
241 if (!pm_runtime_active(core->dev)) {
242 ret = false;
243 goto done;
244 }
245 }
246
247 /*
248 * This could be called with the enable lock held, or from atomic
249 * context. If the parent isn't enabled already, we can't do
250 * anything here. We can also assume this clock isn't enabled.
251 */
252 if ((core->flags & CLK_OPS_PARENT_ENABLE) && core->parent)
253 if (!clk_core_is_enabled(core->parent)) {
254 ret = false;
255 goto done;
256 }
257
258 ret = core->ops->is_enabled(core->hw);
259done:
260 if (core->rpm_enabled)
261 pm_runtime_put(core->dev);
262
263 return ret;
264}
265
266/*** helper functions ***/
267
268const char *__clk_get_name(const struct clk *clk)
269{
270 return !clk ? NULL : clk->core->name;
271}
272EXPORT_SYMBOL_GPL(__clk_get_name);
273
274const char *clk_hw_get_name(const struct clk_hw *hw)
275{
276 return hw->core->name;
277}
278EXPORT_SYMBOL_GPL(clk_hw_get_name);
279
280struct clk_hw *__clk_get_hw(struct clk *clk)
281{
282 return !clk ? NULL : clk->core->hw;
283}
284EXPORT_SYMBOL_GPL(__clk_get_hw);
285
286unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
287{
288 return hw->core->num_parents;
289}
290EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
291
292struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
293{
294 return hw->core->parent ? hw->core->parent->hw : NULL;
295}
296EXPORT_SYMBOL_GPL(clk_hw_get_parent);
297
298static struct clk_core *__clk_lookup_subtree(const char *name,
299 struct clk_core *core)
300{
301 struct clk_core *child;
302 struct clk_core *ret;
303
304 if (!strcmp(core->name, name))
305 return core;
306
307 hlist_for_each_entry(child, &core->children, child_node) {
308 ret = __clk_lookup_subtree(name, child);
309 if (ret)
310 return ret;
311 }
312
313 return NULL;
314}
315
316static struct clk_core *clk_core_lookup(const char *name)
317{
318 struct clk_core *root_clk;
319 struct clk_core *ret;
320
321 if (!name)
322 return NULL;
323
324 /* search the 'proper' clk tree first */
325 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
326 ret = __clk_lookup_subtree(name, root_clk);
327 if (ret)
328 return ret;
329 }
330
331 /* if not found, then search the orphan tree */
332 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
333 ret = __clk_lookup_subtree(name, root_clk);
334 if (ret)
335 return ret;
336 }
337
338 return NULL;
339}
340
341#ifdef CONFIG_OF
342static int of_parse_clkspec(const struct device_node *np, int index,
343 const char *name, struct of_phandle_args *out_args);
344static struct clk_hw *
345of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec);
346#else
347static inline int of_parse_clkspec(const struct device_node *np, int index,
348 const char *name,
349 struct of_phandle_args *out_args)
350{
351 return -ENOENT;
352}
353static inline struct clk_hw *
354of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
355{
356 return ERR_PTR(-ENOENT);
357}
358#endif
359
360/**
361 * clk_core_get - Find the clk_core parent of a clk
362 * @core: clk to find parent of
363 * @p_index: parent index to search for
364 *
365 * This is the preferred method for clk providers to find the parent of a
366 * clk when that parent is external to the clk controller. The parent_names
367 * array is indexed and treated as a local name matching a string in the device
368 * node's 'clock-names' property or as the 'con_id' matching the device's
369 * dev_name() in a clk_lookup. This allows clk providers to use their own
370 * namespace instead of looking for a globally unique parent string.
371 *
372 * For example the following DT snippet would allow a clock registered by the
373 * clock-controller@c001 that has a clk_init_data::parent_data array
374 * with 'xtal' in the 'name' member to find the clock provided by the
375 * clock-controller@f00abcd without needing to get the globally unique name of
376 * the xtal clk.
377 *
378 * parent: clock-controller@f00abcd {
379 * reg = <0xf00abcd 0xabcd>;
380 * #clock-cells = <0>;
381 * };
382 *
383 * clock-controller@c001 {
384 * reg = <0xc001 0xf00d>;
385 * clocks = <&parent>;
386 * clock-names = "xtal";
387 * #clock-cells = <1>;
388 * };
389 *
390 * Returns: -ENOENT when the provider can't be found or the clk doesn't
391 * exist in the provider or the name can't be found in the DT node or
392 * in a clkdev lookup. NULL when the provider knows about the clk but it
393 * isn't provided on this system.
394 * A valid clk_core pointer when the clk can be found in the provider.
395 */
396static struct clk_core *clk_core_get(struct clk_core *core, u8 p_index)
397{
398 const char *name = core->parents[p_index].fw_name;
399 int index = core->parents[p_index].index;
400 struct clk_hw *hw = ERR_PTR(-ENOENT);
401 struct device *dev = core->dev;
402 const char *dev_id = dev ? dev_name(dev) : NULL;
403 struct device_node *np = core->of_node;
404 struct of_phandle_args clkspec;
405
406 if (np && (name || index >= 0) &&
407 !of_parse_clkspec(np, index, name, &clkspec)) {
408 hw = of_clk_get_hw_from_clkspec(&clkspec);
409 of_node_put(clkspec.np);
410 } else if (name) {
411 /*
412 * If the DT search above couldn't find the provider fallback to
413 * looking up via clkdev based clk_lookups.
414 */
415 hw = clk_find_hw(dev_id, name);
416 }
417
418 if (IS_ERR(hw))
419 return ERR_CAST(hw);
420
421 return hw->core;
422}
423
424static void clk_core_fill_parent_index(struct clk_core *core, u8 index)
425{
426 struct clk_parent_map *entry = &core->parents[index];
427 struct clk_core *parent;
428
429 if (entry->hw) {
430 parent = entry->hw->core;
431 } else {
432 parent = clk_core_get(core, index);
433 if (PTR_ERR(parent) == -ENOENT && entry->name)
434 parent = clk_core_lookup(entry->name);
435 }
436
437 /*
438 * We have a direct reference but it isn't registered yet?
439 * Orphan it and let clk_reparent() update the orphan status
440 * when the parent is registered.
441 */
442 if (!parent)
443 parent = ERR_PTR(-EPROBE_DEFER);
444
445 /* Only cache it if it's not an error */
446 if (!IS_ERR(parent))
447 entry->core = parent;
448}
449
450static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
451 u8 index)
452{
453 if (!core || index >= core->num_parents || !core->parents)
454 return NULL;
455
456 if (!core->parents[index].core)
457 clk_core_fill_parent_index(core, index);
458
459 return core->parents[index].core;
460}
461
462struct clk_hw *
463clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
464{
465 struct clk_core *parent;
466
467 parent = clk_core_get_parent_by_index(hw->core, index);
468
469 return !parent ? NULL : parent->hw;
470}
471EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
472
473unsigned int __clk_get_enable_count(struct clk *clk)
474{
475 return !clk ? 0 : clk->core->enable_count;
476}
477
478static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
479{
480 if (!core)
481 return 0;
482
483 if (!core->num_parents || core->parent)
484 return core->rate;
485
486 /*
487 * Clk must have a parent because num_parents > 0 but the parent isn't
488 * known yet. Best to return 0 as the rate of this clk until we can
489 * properly recalc the rate based on the parent's rate.
490 */
491 return 0;
492}
493
494unsigned long clk_hw_get_rate(const struct clk_hw *hw)
495{
496 return clk_core_get_rate_nolock(hw->core);
497}
498EXPORT_SYMBOL_GPL(clk_hw_get_rate);
499
500static unsigned long clk_core_get_accuracy_no_lock(struct clk_core *core)
501{
502 if (!core)
503 return 0;
504
505 return core->accuracy;
506}
507
508unsigned long clk_hw_get_flags(const struct clk_hw *hw)
509{
510 return hw->core->flags;
511}
512EXPORT_SYMBOL_GPL(clk_hw_get_flags);
513
514bool clk_hw_is_prepared(const struct clk_hw *hw)
515{
516 return clk_core_is_prepared(hw->core);
517}
518EXPORT_SYMBOL_GPL(clk_hw_is_prepared);
519
520bool clk_hw_rate_is_protected(const struct clk_hw *hw)
521{
522 return clk_core_rate_is_protected(hw->core);
523}
524EXPORT_SYMBOL_GPL(clk_hw_rate_is_protected);
525
526bool clk_hw_is_enabled(const struct clk_hw *hw)
527{
528 return clk_core_is_enabled(hw->core);
529}
530EXPORT_SYMBOL_GPL(clk_hw_is_enabled);
531
532bool __clk_is_enabled(struct clk *clk)
533{
534 if (!clk)
535 return false;
536
537 return clk_core_is_enabled(clk->core);
538}
539EXPORT_SYMBOL_GPL(__clk_is_enabled);
540
541static bool mux_is_better_rate(unsigned long rate, unsigned long now,
542 unsigned long best, unsigned long flags)
543{
544 if (flags & CLK_MUX_ROUND_CLOSEST)
545 return abs(now - rate) < abs(best - rate);
546
547 return now <= rate && now > best;
548}
549
550static void clk_core_init_rate_req(struct clk_core * const core,
551 struct clk_rate_request *req,
552 unsigned long rate);
553
554static int clk_core_round_rate_nolock(struct clk_core *core,
555 struct clk_rate_request *req);
556
557static bool clk_core_has_parent(struct clk_core *core, const struct clk_core *parent)
558{
559 struct clk_core *tmp;
560 unsigned int i;
561
562 /* Optimize for the case where the parent is already the parent. */
563 if (core->parent == parent)
564 return true;
565
566 for (i = 0; i < core->num_parents; i++) {
567 tmp = clk_core_get_parent_by_index(core, i);
568 if (!tmp)
569 continue;
570
571 if (tmp == parent)
572 return true;
573 }
574
575 return false;
576}
577
578static void
579clk_core_forward_rate_req(struct clk_core *core,
580 const struct clk_rate_request *old_req,
581 struct clk_core *parent,
582 struct clk_rate_request *req,
583 unsigned long parent_rate)
584{
585 if (WARN_ON(!clk_core_has_parent(core, parent)))
586 return;
587
588 clk_core_init_rate_req(parent, req, parent_rate);
589
590 if (req->min_rate < old_req->min_rate)
591 req->min_rate = old_req->min_rate;
592
593 if (req->max_rate > old_req->max_rate)
594 req->max_rate = old_req->max_rate;
595}
596
597static int
598clk_core_determine_rate_no_reparent(struct clk_hw *hw,
599 struct clk_rate_request *req)
600{
601 struct clk_core *core = hw->core;
602 struct clk_core *parent = core->parent;
603 unsigned long best;
604 int ret;
605
606 if (core->flags & CLK_SET_RATE_PARENT) {
607 struct clk_rate_request parent_req;
608
609 if (!parent) {
610 req->rate = 0;
611 return 0;
612 }
613
614 clk_core_forward_rate_req(core, req, parent, &parent_req,
615 req->rate);
616
617 trace_clk_rate_request_start(&parent_req);
618
619 ret = clk_core_round_rate_nolock(parent, &parent_req);
620 if (ret)
621 return ret;
622
623 trace_clk_rate_request_done(&parent_req);
624
625 best = parent_req.rate;
626 } else if (parent) {
627 best = clk_core_get_rate_nolock(parent);
628 } else {
629 best = clk_core_get_rate_nolock(core);
630 }
631
632 req->best_parent_rate = best;
633 req->rate = best;
634
635 return 0;
636}
637
638int clk_mux_determine_rate_flags(struct clk_hw *hw,
639 struct clk_rate_request *req,
640 unsigned long flags)
641{
642 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
643 int i, num_parents, ret;
644 unsigned long best = 0;
645
646 /* if NO_REPARENT flag set, pass through to current parent */
647 if (core->flags & CLK_SET_RATE_NO_REPARENT)
648 return clk_core_determine_rate_no_reparent(hw, req);
649
650 /* find the parent that can provide the fastest rate <= rate */
651 num_parents = core->num_parents;
652 for (i = 0; i < num_parents; i++) {
653 unsigned long parent_rate;
654
655 parent = clk_core_get_parent_by_index(core, i);
656 if (!parent)
657 continue;
658
659 if (core->flags & CLK_SET_RATE_PARENT) {
660 struct clk_rate_request parent_req;
661
662 clk_core_forward_rate_req(core, req, parent, &parent_req, req->rate);
663
664 trace_clk_rate_request_start(&parent_req);
665
666 ret = clk_core_round_rate_nolock(parent, &parent_req);
667 if (ret)
668 continue;
669
670 trace_clk_rate_request_done(&parent_req);
671
672 parent_rate = parent_req.rate;
673 } else {
674 parent_rate = clk_core_get_rate_nolock(parent);
675 }
676
677 if (mux_is_better_rate(req->rate, parent_rate,
678 best, flags)) {
679 best_parent = parent;
680 best = parent_rate;
681 }
682 }
683
684 if (!best_parent)
685 return -EINVAL;
686
687 req->best_parent_hw = best_parent->hw;
688 req->best_parent_rate = best;
689 req->rate = best;
690
691 return 0;
692}
693EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);
694
695struct clk *__clk_lookup(const char *name)
696{
697 struct clk_core *core = clk_core_lookup(name);
698
699 return !core ? NULL : core->hw->clk;
700}
701
702static void clk_core_get_boundaries(struct clk_core *core,
703 unsigned long *min_rate,
704 unsigned long *max_rate)
705{
706 struct clk *clk_user;
707
708 lockdep_assert_held(&prepare_lock);
709
710 *min_rate = core->min_rate;
711 *max_rate = core->max_rate;
712
713 hlist_for_each_entry(clk_user, &core->clks, clks_node)
714 *min_rate = max(*min_rate, clk_user->min_rate);
715
716 hlist_for_each_entry(clk_user, &core->clks, clks_node)
717 *max_rate = min(*max_rate, clk_user->max_rate);
718}
719
720/*
721 * clk_hw_get_rate_range() - returns the clock rate range for a hw clk
722 * @hw: the hw clk we want to get the range from
723 * @min_rate: pointer to the variable that will hold the minimum
724 * @max_rate: pointer to the variable that will hold the maximum
725 *
726 * Fills the @min_rate and @max_rate variables with the minimum and
727 * maximum that clock can reach.
728 */
729void clk_hw_get_rate_range(struct clk_hw *hw, unsigned long *min_rate,
730 unsigned long *max_rate)
731{
732 clk_core_get_boundaries(hw->core, min_rate, max_rate);
733}
734EXPORT_SYMBOL_GPL(clk_hw_get_rate_range);
735
736static bool clk_core_check_boundaries(struct clk_core *core,
737 unsigned long min_rate,
738 unsigned long max_rate)
739{
740 struct clk *user;
741
742 lockdep_assert_held(&prepare_lock);
743
744 if (min_rate > core->max_rate || max_rate < core->min_rate)
745 return false;
746
747 hlist_for_each_entry(user, &core->clks, clks_node)
748 if (min_rate > user->max_rate || max_rate < user->min_rate)
749 return false;
750
751 return true;
752}
753
754void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
755 unsigned long max_rate)
756{
757 hw->core->min_rate = min_rate;
758 hw->core->max_rate = max_rate;
759}
760EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
761
762/*
763 * __clk_mux_determine_rate - clk_ops::determine_rate implementation for a mux type clk
764 * @hw: mux type clk to determine rate on
765 * @req: rate request, also used to return preferred parent and frequencies
766 *
767 * Helper for finding best parent to provide a given frequency. This can be used
768 * directly as a determine_rate callback (e.g. for a mux), or from a more
769 * complex clock that may combine a mux with other operations.
770 *
771 * Returns: 0 on success, -EERROR value on error
772 */
773int __clk_mux_determine_rate(struct clk_hw *hw,
774 struct clk_rate_request *req)
775{
776 return clk_mux_determine_rate_flags(hw, req, 0);
777}
778EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
779
780int __clk_mux_determine_rate_closest(struct clk_hw *hw,
781 struct clk_rate_request *req)
782{
783 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
784}
785EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
786
787/*
788 * clk_hw_determine_rate_no_reparent - clk_ops::determine_rate implementation for a clk that doesn't reparent
789 * @hw: mux type clk to determine rate on
790 * @req: rate request, also used to return preferred frequency
791 *
792 * Helper for finding best parent rate to provide a given frequency.
793 * This can be used directly as a determine_rate callback (e.g. for a
794 * mux), or from a more complex clock that may combine a mux with other
795 * operations.
796 *
797 * Returns: 0 on success, -EERROR value on error
798 */
799int clk_hw_determine_rate_no_reparent(struct clk_hw *hw,
800 struct clk_rate_request *req)
801{
802 return clk_core_determine_rate_no_reparent(hw, req);
803}
804EXPORT_SYMBOL_GPL(clk_hw_determine_rate_no_reparent);
805
806/*** clk api ***/
807
808static void clk_core_rate_unprotect(struct clk_core *core)
809{
810 lockdep_assert_held(&prepare_lock);
811
812 if (!core)
813 return;
814
815 if (WARN(core->protect_count == 0,
816 "%s already unprotected\n", core->name))
817 return;
818
819 if (--core->protect_count > 0)
820 return;
821
822 clk_core_rate_unprotect(core->parent);
823}
824
825static int clk_core_rate_nuke_protect(struct clk_core *core)
826{
827 int ret;
828
829 lockdep_assert_held(&prepare_lock);
830
831 if (!core)
832 return -EINVAL;
833
834 if (core->protect_count == 0)
835 return 0;
836
837 ret = core->protect_count;
838 core->protect_count = 1;
839 clk_core_rate_unprotect(core);
840
841 return ret;
842}
843
844/**
845 * clk_rate_exclusive_put - release exclusivity over clock rate control
846 * @clk: the clk over which the exclusivity is released
847 *
848 * clk_rate_exclusive_put() completes a critical section during which a clock
849 * consumer cannot tolerate any other consumer making any operation on the
850 * clock which could result in a rate change or rate glitch. Exclusive clocks
851 * cannot have their rate changed, either directly or indirectly due to changes
852 * further up the parent chain of clocks. As a result, clocks up parent chain
853 * also get under exclusive control of the calling consumer.
854 *
855 * If exlusivity is claimed more than once on clock, even by the same consumer,
856 * the rate effectively gets locked as exclusivity can't be preempted.
857 *
858 * Calls to clk_rate_exclusive_put() must be balanced with calls to
859 * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
860 * error status.
861 */
862void clk_rate_exclusive_put(struct clk *clk)
863{
864 if (!clk)
865 return;
866
867 clk_prepare_lock();
868
869 /*
870 * if there is something wrong with this consumer protect count, stop
871 * here before messing with the provider
872 */
873 if (WARN_ON(clk->exclusive_count <= 0))
874 goto out;
875
876 clk_core_rate_unprotect(clk->core);
877 clk->exclusive_count--;
878out:
879 clk_prepare_unlock();
880}
881EXPORT_SYMBOL_GPL(clk_rate_exclusive_put);
882
883static void clk_core_rate_protect(struct clk_core *core)
884{
885 lockdep_assert_held(&prepare_lock);
886
887 if (!core)
888 return;
889
890 if (core->protect_count == 0)
891 clk_core_rate_protect(core->parent);
892
893 core->protect_count++;
894}
895
896static void clk_core_rate_restore_protect(struct clk_core *core, int count)
897{
898 lockdep_assert_held(&prepare_lock);
899
900 if (!core)
901 return;
902
903 if (count == 0)
904 return;
905
906 clk_core_rate_protect(core);
907 core->protect_count = count;
908}
909
910/**
911 * clk_rate_exclusive_get - get exclusivity over the clk rate control
912 * @clk: the clk over which the exclusity of rate control is requested
913 *
914 * clk_rate_exclusive_get() begins a critical section during which a clock
915 * consumer cannot tolerate any other consumer making any operation on the
916 * clock which could result in a rate change or rate glitch. Exclusive clocks
917 * cannot have their rate changed, either directly or indirectly due to changes
918 * further up the parent chain of clocks. As a result, clocks up parent chain
919 * also get under exclusive control of the calling consumer.
920 *
921 * If exlusivity is claimed more than once on clock, even by the same consumer,
922 * the rate effectively gets locked as exclusivity can't be preempted.
923 *
924 * Calls to clk_rate_exclusive_get() should be balanced with calls to
925 * clk_rate_exclusive_put(). Calls to this function may sleep.
926 * Returns 0 on success, -EERROR otherwise
927 */
928int clk_rate_exclusive_get(struct clk *clk)
929{
930 if (!clk)
931 return 0;
932
933 clk_prepare_lock();
934 clk_core_rate_protect(clk->core);
935 clk->exclusive_count++;
936 clk_prepare_unlock();
937
938 return 0;
939}
940EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
941
942static void clk_core_unprepare(struct clk_core *core)
943{
944 lockdep_assert_held(&prepare_lock);
945
946 if (!core)
947 return;
948
949 if (WARN(core->prepare_count == 0,
950 "%s already unprepared\n", core->name))
951 return;
952
953 if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL,
954 "Unpreparing critical %s\n", core->name))
955 return;
956
957 if (core->flags & CLK_SET_RATE_GATE)
958 clk_core_rate_unprotect(core);
959
960 if (--core->prepare_count > 0)
961 return;
962
963 WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);
964
965 trace_clk_unprepare(core);
966
967 if (core->ops->unprepare)
968 core->ops->unprepare(core->hw);
969
970 trace_clk_unprepare_complete(core);
971 clk_core_unprepare(core->parent);
972 clk_pm_runtime_put(core);
973}
974
975static void clk_core_unprepare_lock(struct clk_core *core)
976{
977 clk_prepare_lock();
978 clk_core_unprepare(core);
979 clk_prepare_unlock();
980}
981
982/**
983 * clk_unprepare - undo preparation of a clock source
984 * @clk: the clk being unprepared
985 *
986 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
987 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
988 * if the operation may sleep. One example is a clk which is accessed over
989 * I2c. In the complex case a clk gate operation may require a fast and a slow
990 * part. It is this reason that clk_unprepare and clk_disable are not mutually
991 * exclusive. In fact clk_disable must be called before clk_unprepare.
992 */
993void clk_unprepare(struct clk *clk)
994{
995 if (IS_ERR_OR_NULL(clk))
996 return;
997
998 clk_core_unprepare_lock(clk->core);
999}
1000EXPORT_SYMBOL_GPL(clk_unprepare);
1001
1002static int clk_core_prepare(struct clk_core *core)
1003{
1004 int ret = 0;
1005
1006 lockdep_assert_held(&prepare_lock);
1007
1008 if (!core)
1009 return 0;
1010
1011 if (core->prepare_count == 0) {
1012 ret = clk_pm_runtime_get(core);
1013 if (ret)
1014 return ret;
1015
1016 ret = clk_core_prepare(core->parent);
1017 if (ret)
1018 goto runtime_put;
1019
1020 trace_clk_prepare(core);
1021
1022 if (core->ops->prepare)
1023 ret = core->ops->prepare(core->hw);
1024
1025 trace_clk_prepare_complete(core);
1026
1027 if (ret)
1028 goto unprepare;
1029 }
1030
1031 core->prepare_count++;
1032
1033 /*
1034 * CLK_SET_RATE_GATE is a special case of clock protection
1035 * Instead of a consumer claiming exclusive rate control, it is
1036 * actually the provider which prevents any consumer from making any
1037 * operation which could result in a rate change or rate glitch while
1038 * the clock is prepared.
1039 */
1040 if (core->flags & CLK_SET_RATE_GATE)
1041 clk_core_rate_protect(core);
1042
1043 return 0;
1044unprepare:
1045 clk_core_unprepare(core->parent);
1046runtime_put:
1047 clk_pm_runtime_put(core);
1048 return ret;
1049}
1050
1051static int clk_core_prepare_lock(struct clk_core *core)
1052{
1053 int ret;
1054
1055 clk_prepare_lock();
1056 ret = clk_core_prepare(core);
1057 clk_prepare_unlock();
1058
1059 return ret;
1060}
1061
1062/**
1063 * clk_prepare - prepare a clock source
1064 * @clk: the clk being prepared
1065 *
1066 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
1067 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
1068 * operation may sleep. One example is a clk which is accessed over I2c. In
1069 * the complex case a clk ungate operation may require a fast and a slow part.
1070 * It is this reason that clk_prepare and clk_enable are not mutually
1071 * exclusive. In fact clk_prepare must be called before clk_enable.
1072 * Returns 0 on success, -EERROR otherwise.
1073 */
1074int clk_prepare(struct clk *clk)
1075{
1076 if (!clk)
1077 return 0;
1078
1079 return clk_core_prepare_lock(clk->core);
1080}
1081EXPORT_SYMBOL_GPL(clk_prepare);
1082
1083static void clk_core_disable(struct clk_core *core)
1084{
1085 lockdep_assert_held(&enable_lock);
1086
1087 if (!core)
1088 return;
1089
1090 if (WARN(core->enable_count == 0, "%s already disabled\n", core->name))
1091 return;
1092
1093 if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL,
1094 "Disabling critical %s\n", core->name))
1095 return;
1096
1097 if (--core->enable_count > 0)
1098 return;
1099
1100 trace_clk_disable(core);
1101
1102 if (core->ops->disable)
1103 core->ops->disable(core->hw);
1104
1105 trace_clk_disable_complete(core);
1106
1107 clk_core_disable(core->parent);
1108}
1109
1110static void clk_core_disable_lock(struct clk_core *core)
1111{
1112 unsigned long flags;
1113
1114 flags = clk_enable_lock();
1115 clk_core_disable(core);
1116 clk_enable_unlock(flags);
1117}
1118
1119/**
1120 * clk_disable - gate a clock
1121 * @clk: the clk being gated
1122 *
1123 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
1124 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
1125 * clk if the operation is fast and will never sleep. One example is a
1126 * SoC-internal clk which is controlled via simple register writes. In the
1127 * complex case a clk gate operation may require a fast and a slow part. It is
1128 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
1129 * In fact clk_disable must be called before clk_unprepare.
1130 */
1131void clk_disable(struct clk *clk)
1132{
1133 if (IS_ERR_OR_NULL(clk))
1134 return;
1135
1136 clk_core_disable_lock(clk->core);
1137}
1138EXPORT_SYMBOL_GPL(clk_disable);
1139
1140static int clk_core_enable(struct clk_core *core)
1141{
1142 int ret = 0;
1143
1144 lockdep_assert_held(&enable_lock);
1145
1146 if (!core)
1147 return 0;
1148
1149 if (WARN(core->prepare_count == 0,
1150 "Enabling unprepared %s\n", core->name))
1151 return -ESHUTDOWN;
1152
1153 if (core->enable_count == 0) {
1154 ret = clk_core_enable(core->parent);
1155
1156 if (ret)
1157 return ret;
1158
1159 trace_clk_enable(core);
1160
1161 if (core->ops->enable)
1162 ret = core->ops->enable(core->hw);
1163
1164 trace_clk_enable_complete(core);
1165
1166 if (ret) {
1167 clk_core_disable(core->parent);
1168 return ret;
1169 }
1170 }
1171
1172 core->enable_count++;
1173 return 0;
1174}
1175
1176static int clk_core_enable_lock(struct clk_core *core)
1177{
1178 unsigned long flags;
1179 int ret;
1180
1181 flags = clk_enable_lock();
1182 ret = clk_core_enable(core);
1183 clk_enable_unlock(flags);
1184
1185 return ret;
1186}
1187
1188/**
1189 * clk_gate_restore_context - restore context for poweroff
1190 * @hw: the clk_hw pointer of clock whose state is to be restored
1191 *
1192 * The clock gate restore context function enables or disables
1193 * the gate clocks based on the enable_count. This is done in cases
1194 * where the clock context is lost and based on the enable_count
1195 * the clock either needs to be enabled/disabled. This
1196 * helps restore the state of gate clocks.
1197 */
1198void clk_gate_restore_context(struct clk_hw *hw)
1199{
1200 struct clk_core *core = hw->core;
1201
1202 if (core->enable_count)
1203 core->ops->enable(hw);
1204 else
1205 core->ops->disable(hw);
1206}
1207EXPORT_SYMBOL_GPL(clk_gate_restore_context);
1208
1209static int clk_core_save_context(struct clk_core *core)
1210{
1211 struct clk_core *child;
1212 int ret = 0;
1213
1214 hlist_for_each_entry(child, &core->children, child_node) {
1215 ret = clk_core_save_context(child);
1216 if (ret < 0)
1217 return ret;
1218 }
1219
1220 if (core->ops && core->ops->save_context)
1221 ret = core->ops->save_context(core->hw);
1222
1223 return ret;
1224}
1225
1226static void clk_core_restore_context(struct clk_core *core)
1227{
1228 struct clk_core *child;
1229
1230 if (core->ops && core->ops->restore_context)
1231 core->ops->restore_context(core->hw);
1232
1233 hlist_for_each_entry(child, &core->children, child_node)
1234 clk_core_restore_context(child);
1235}
1236
1237/**
1238 * clk_save_context - save clock context for poweroff
1239 *
1240 * Saves the context of the clock register for powerstates in which the
1241 * contents of the registers will be lost. Occurs deep within the suspend
1242 * code. Returns 0 on success.
1243 */
1244int clk_save_context(void)
1245{
1246 struct clk_core *clk;
1247 int ret;
1248
1249 hlist_for_each_entry(clk, &clk_root_list, child_node) {
1250 ret = clk_core_save_context(clk);
1251 if (ret < 0)
1252 return ret;
1253 }
1254
1255 hlist_for_each_entry(clk, &clk_orphan_list, child_node) {
1256 ret = clk_core_save_context(clk);
1257 if (ret < 0)
1258 return ret;
1259 }
1260
1261 return 0;
1262}
1263EXPORT_SYMBOL_GPL(clk_save_context);
1264
1265/**
1266 * clk_restore_context - restore clock context after poweroff
1267 *
1268 * Restore the saved clock context upon resume.
1269 *
1270 */
1271void clk_restore_context(void)
1272{
1273 struct clk_core *core;
1274
1275 hlist_for_each_entry(core, &clk_root_list, child_node)
1276 clk_core_restore_context(core);
1277
1278 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1279 clk_core_restore_context(core);
1280}
1281EXPORT_SYMBOL_GPL(clk_restore_context);
1282
1283/**
1284 * clk_enable - ungate a clock
1285 * @clk: the clk being ungated
1286 *
1287 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
1288 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
1289 * if the operation will never sleep. One example is a SoC-internal clk which
1290 * is controlled via simple register writes. In the complex case a clk ungate
1291 * operation may require a fast and a slow part. It is this reason that
1292 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
1293 * must be called before clk_enable. Returns 0 on success, -EERROR
1294 * otherwise.
1295 */
1296int clk_enable(struct clk *clk)
1297{
1298 if (!clk)
1299 return 0;
1300
1301 return clk_core_enable_lock(clk->core);
1302}
1303EXPORT_SYMBOL_GPL(clk_enable);
1304
1305/**
1306 * clk_is_enabled_when_prepared - indicate if preparing a clock also enables it.
1307 * @clk: clock source
1308 *
1309 * Returns true if clk_prepare() implicitly enables the clock, effectively
1310 * making clk_enable()/clk_disable() no-ops, false otherwise.
1311 *
1312 * This is of interest mainly to power management code where actually
1313 * disabling the clock also requires unpreparing it to have any material
1314 * effect.
1315 *
1316 * Regardless of the value returned here, the caller must always invoke
1317 * clk_enable() or clk_prepare_enable() and counterparts for usage counts
1318 * to be right.
1319 */
1320bool clk_is_enabled_when_prepared(struct clk *clk)
1321{
1322 return clk && !(clk->core->ops->enable && clk->core->ops->disable);
1323}
1324EXPORT_SYMBOL_GPL(clk_is_enabled_when_prepared);
1325
1326static int clk_core_prepare_enable(struct clk_core *core)
1327{
1328 int ret;
1329
1330 ret = clk_core_prepare_lock(core);
1331 if (ret)
1332 return ret;
1333
1334 ret = clk_core_enable_lock(core);
1335 if (ret)
1336 clk_core_unprepare_lock(core);
1337
1338 return ret;
1339}
1340
1341static void clk_core_disable_unprepare(struct clk_core *core)
1342{
1343 clk_core_disable_lock(core);
1344 clk_core_unprepare_lock(core);
1345}
1346
1347static void __init clk_unprepare_unused_subtree(struct clk_core *core)
1348{
1349 struct clk_core *child;
1350
1351 lockdep_assert_held(&prepare_lock);
1352
1353 hlist_for_each_entry(child, &core->children, child_node)
1354 clk_unprepare_unused_subtree(child);
1355
1356 if (core->prepare_count)
1357 return;
1358
1359 if (core->flags & CLK_IGNORE_UNUSED)
1360 return;
1361
1362 if (clk_pm_runtime_get(core))
1363 return;
1364
1365 if (clk_core_is_prepared(core)) {
1366 trace_clk_unprepare(core);
1367 if (core->ops->unprepare_unused)
1368 core->ops->unprepare_unused(core->hw);
1369 else if (core->ops->unprepare)
1370 core->ops->unprepare(core->hw);
1371 trace_clk_unprepare_complete(core);
1372 }
1373
1374 clk_pm_runtime_put(core);
1375}
1376
1377static void __init clk_disable_unused_subtree(struct clk_core *core)
1378{
1379 struct clk_core *child;
1380 unsigned long flags;
1381
1382 lockdep_assert_held(&prepare_lock);
1383
1384 hlist_for_each_entry(child, &core->children, child_node)
1385 clk_disable_unused_subtree(child);
1386
1387 if (core->flags & CLK_OPS_PARENT_ENABLE)
1388 clk_core_prepare_enable(core->parent);
1389
1390 if (clk_pm_runtime_get(core))
1391 goto unprepare_out;
1392
1393 flags = clk_enable_lock();
1394
1395 if (core->enable_count)
1396 goto unlock_out;
1397
1398 if (core->flags & CLK_IGNORE_UNUSED)
1399 goto unlock_out;
1400
1401 /*
1402 * some gate clocks have special needs during the disable-unused
1403 * sequence. call .disable_unused if available, otherwise fall
1404 * back to .disable
1405 */
1406 if (clk_core_is_enabled(core)) {
1407 trace_clk_disable(core);
1408 if (core->ops->disable_unused)
1409 core->ops->disable_unused(core->hw);
1410 else if (core->ops->disable)
1411 core->ops->disable(core->hw);
1412 trace_clk_disable_complete(core);
1413 }
1414
1415unlock_out:
1416 clk_enable_unlock(flags);
1417 clk_pm_runtime_put(core);
1418unprepare_out:
1419 if (core->flags & CLK_OPS_PARENT_ENABLE)
1420 clk_core_disable_unprepare(core->parent);
1421}
1422
1423static bool clk_ignore_unused __initdata;
1424static int __init clk_ignore_unused_setup(char *__unused)
1425{
1426 clk_ignore_unused = true;
1427 return 1;
1428}
1429__setup("clk_ignore_unused", clk_ignore_unused_setup);
1430
1431static int __init clk_disable_unused(void)
1432{
1433 struct clk_core *core;
1434
1435 if (clk_ignore_unused) {
1436 pr_warn("clk: Not disabling unused clocks\n");
1437 return 0;
1438 }
1439
1440 pr_info("clk: Disabling unused clocks\n");
1441
1442 clk_prepare_lock();
1443
1444 hlist_for_each_entry(core, &clk_root_list, child_node)
1445 clk_disable_unused_subtree(core);
1446
1447 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1448 clk_disable_unused_subtree(core);
1449
1450 hlist_for_each_entry(core, &clk_root_list, child_node)
1451 clk_unprepare_unused_subtree(core);
1452
1453 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1454 clk_unprepare_unused_subtree(core);
1455
1456 clk_prepare_unlock();
1457
1458 return 0;
1459}
1460late_initcall_sync(clk_disable_unused);
1461
1462static int clk_core_determine_round_nolock(struct clk_core *core,
1463 struct clk_rate_request *req)
1464{
1465 long rate;
1466
1467 lockdep_assert_held(&prepare_lock);
1468
1469 if (!core)
1470 return 0;
1471
1472 /*
1473 * Some clock providers hand-craft their clk_rate_requests and
1474 * might not fill min_rate and max_rate.
1475 *
1476 * If it's the case, clamping the rate is equivalent to setting
1477 * the rate to 0 which is bad. Skip the clamping but complain so
1478 * that it gets fixed, hopefully.
1479 */
1480 if (!req->min_rate && !req->max_rate)
1481 pr_warn("%s: %s: clk_rate_request has initialized min or max rate.\n",
1482 __func__, core->name);
1483 else
1484 req->rate = clamp(req->rate, req->min_rate, req->max_rate);
1485
1486 /*
1487 * At this point, core protection will be disabled
1488 * - if the provider is not protected at all
1489 * - if the calling consumer is the only one which has exclusivity
1490 * over the provider
1491 */
1492 if (clk_core_rate_is_protected(core)) {
1493 req->rate = core->rate;
1494 } else if (core->ops->determine_rate) {
1495 return core->ops->determine_rate(core->hw, req);
1496 } else if (core->ops->round_rate) {
1497 rate = core->ops->round_rate(core->hw, req->rate,
1498 &req->best_parent_rate);
1499 if (rate < 0)
1500 return rate;
1501
1502 req->rate = rate;
1503 } else {
1504 return -EINVAL;
1505 }
1506
1507 return 0;
1508}
1509
1510static void clk_core_init_rate_req(struct clk_core * const core,
1511 struct clk_rate_request *req,
1512 unsigned long rate)
1513{
1514 struct clk_core *parent;
1515
1516 if (WARN_ON(!req))
1517 return;
1518
1519 memset(req, 0, sizeof(*req));
1520 req->max_rate = ULONG_MAX;
1521
1522 if (!core)
1523 return;
1524
1525 req->core = core;
1526 req->rate = rate;
1527 clk_core_get_boundaries(core, &req->min_rate, &req->max_rate);
1528
1529 parent = core->parent;
1530 if (parent) {
1531 req->best_parent_hw = parent->hw;
1532 req->best_parent_rate = parent->rate;
1533 } else {
1534 req->best_parent_hw = NULL;
1535 req->best_parent_rate = 0;
1536 }
1537}
1538
1539/**
1540 * clk_hw_init_rate_request - Initializes a clk_rate_request
1541 * @hw: the clk for which we want to submit a rate request
1542 * @req: the clk_rate_request structure we want to initialise
1543 * @rate: the rate which is to be requested
1544 *
1545 * Initializes a clk_rate_request structure to submit to
1546 * __clk_determine_rate() or similar functions.
1547 */
1548void clk_hw_init_rate_request(const struct clk_hw *hw,
1549 struct clk_rate_request *req,
1550 unsigned long rate)
1551{
1552 if (WARN_ON(!hw || !req))
1553 return;
1554
1555 clk_core_init_rate_req(hw->core, req, rate);
1556}
1557EXPORT_SYMBOL_GPL(clk_hw_init_rate_request);
1558
1559/**
1560 * clk_hw_forward_rate_request - Forwards a clk_rate_request to a clock's parent
1561 * @hw: the original clock that got the rate request
1562 * @old_req: the original clk_rate_request structure we want to forward
1563 * @parent: the clk we want to forward @old_req to
1564 * @req: the clk_rate_request structure we want to initialise
1565 * @parent_rate: The rate which is to be requested to @parent
1566 *
1567 * Initializes a clk_rate_request structure to submit to a clock parent
1568 * in __clk_determine_rate() or similar functions.
1569 */
1570void clk_hw_forward_rate_request(const struct clk_hw *hw,
1571 const struct clk_rate_request *old_req,
1572 const struct clk_hw *parent,
1573 struct clk_rate_request *req,
1574 unsigned long parent_rate)
1575{
1576 if (WARN_ON(!hw || !old_req || !parent || !req))
1577 return;
1578
1579 clk_core_forward_rate_req(hw->core, old_req,
1580 parent->core, req,
1581 parent_rate);
1582}
1583EXPORT_SYMBOL_GPL(clk_hw_forward_rate_request);
1584
1585static bool clk_core_can_round(struct clk_core * const core)
1586{
1587 return core->ops->determine_rate || core->ops->round_rate;
1588}
1589
1590static int clk_core_round_rate_nolock(struct clk_core *core,
1591 struct clk_rate_request *req)
1592{
1593 int ret;
1594
1595 lockdep_assert_held(&prepare_lock);
1596
1597 if (!core) {
1598 req->rate = 0;
1599 return 0;
1600 }
1601
1602 if (clk_core_can_round(core))
1603 return clk_core_determine_round_nolock(core, req);
1604
1605 if (core->flags & CLK_SET_RATE_PARENT) {
1606 struct clk_rate_request parent_req;
1607
1608 clk_core_forward_rate_req(core, req, core->parent, &parent_req, req->rate);
1609
1610 trace_clk_rate_request_start(&parent_req);
1611
1612 ret = clk_core_round_rate_nolock(core->parent, &parent_req);
1613 if (ret)
1614 return ret;
1615
1616 trace_clk_rate_request_done(&parent_req);
1617
1618 req->best_parent_rate = parent_req.rate;
1619 req->rate = parent_req.rate;
1620
1621 return 0;
1622 }
1623
1624 req->rate = core->rate;
1625 return 0;
1626}
1627
1628/**
1629 * __clk_determine_rate - get the closest rate actually supported by a clock
1630 * @hw: determine the rate of this clock
1631 * @req: target rate request
1632 *
1633 * Useful for clk_ops such as .set_rate and .determine_rate.
1634 */
1635int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
1636{
1637 if (!hw) {
1638 req->rate = 0;
1639 return 0;
1640 }
1641
1642 return clk_core_round_rate_nolock(hw->core, req);
1643}
1644EXPORT_SYMBOL_GPL(__clk_determine_rate);
1645
1646/**
1647 * clk_hw_round_rate() - round the given rate for a hw clk
1648 * @hw: the hw clk for which we are rounding a rate
1649 * @rate: the rate which is to be rounded
1650 *
1651 * Takes in a rate as input and rounds it to a rate that the clk can actually
1652 * use.
1653 *
1654 * Context: prepare_lock must be held.
1655 * For clk providers to call from within clk_ops such as .round_rate,
1656 * .determine_rate.
1657 *
1658 * Return: returns rounded rate of hw clk if clk supports round_rate operation
1659 * else returns the parent rate.
1660 */
1661unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
1662{
1663 int ret;
1664 struct clk_rate_request req;
1665
1666 clk_core_init_rate_req(hw->core, &req, rate);
1667
1668 trace_clk_rate_request_start(&req);
1669
1670 ret = clk_core_round_rate_nolock(hw->core, &req);
1671 if (ret)
1672 return 0;
1673
1674 trace_clk_rate_request_done(&req);
1675
1676 return req.rate;
1677}
1678EXPORT_SYMBOL_GPL(clk_hw_round_rate);
1679
1680/**
1681 * clk_round_rate - round the given rate for a clk
1682 * @clk: the clk for which we are rounding a rate
1683 * @rate: the rate which is to be rounded
1684 *
1685 * Takes in a rate as input and rounds it to a rate that the clk can actually
1686 * use which is then returned. If clk doesn't support round_rate operation
1687 * then the parent rate is returned.
1688 */
1689long clk_round_rate(struct clk *clk, unsigned long rate)
1690{
1691 struct clk_rate_request req;
1692 int ret;
1693
1694 if (!clk)
1695 return 0;
1696
1697 clk_prepare_lock();
1698
1699 if (clk->exclusive_count)
1700 clk_core_rate_unprotect(clk->core);
1701
1702 clk_core_init_rate_req(clk->core, &req, rate);
1703
1704 trace_clk_rate_request_start(&req);
1705
1706 ret = clk_core_round_rate_nolock(clk->core, &req);
1707
1708 trace_clk_rate_request_done(&req);
1709
1710 if (clk->exclusive_count)
1711 clk_core_rate_protect(clk->core);
1712
1713 clk_prepare_unlock();
1714
1715 if (ret)
1716 return ret;
1717
1718 return req.rate;
1719}
1720EXPORT_SYMBOL_GPL(clk_round_rate);
1721
1722/**
1723 * __clk_notify - call clk notifier chain
1724 * @core: clk that is changing rate
1725 * @msg: clk notifier type (see include/linux/clk.h)
1726 * @old_rate: old clk rate
1727 * @new_rate: new clk rate
1728 *
1729 * Triggers a notifier call chain on the clk rate-change notification
1730 * for 'clk'. Passes a pointer to the struct clk and the previous
1731 * and current rates to the notifier callback. Intended to be called by
1732 * internal clock code only. Returns NOTIFY_DONE from the last driver
1733 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1734 * a driver returns that.
1735 */
1736static int __clk_notify(struct clk_core *core, unsigned long msg,
1737 unsigned long old_rate, unsigned long new_rate)
1738{
1739 struct clk_notifier *cn;
1740 struct clk_notifier_data cnd;
1741 int ret = NOTIFY_DONE;
1742
1743 cnd.old_rate = old_rate;
1744 cnd.new_rate = new_rate;
1745
1746 list_for_each_entry(cn, &clk_notifier_list, node) {
1747 if (cn->clk->core == core) {
1748 cnd.clk = cn->clk;
1749 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
1750 &cnd);
1751 if (ret & NOTIFY_STOP_MASK)
1752 return ret;
1753 }
1754 }
1755
1756 return ret;
1757}
1758
1759/**
1760 * __clk_recalc_accuracies
1761 * @core: first clk in the subtree
1762 *
1763 * Walks the subtree of clks starting with clk and recalculates accuracies as
1764 * it goes. Note that if a clk does not implement the .recalc_accuracy
1765 * callback then it is assumed that the clock will take on the accuracy of its
1766 * parent.
1767 */
1768static void __clk_recalc_accuracies(struct clk_core *core)
1769{
1770 unsigned long parent_accuracy = 0;
1771 struct clk_core *child;
1772
1773 lockdep_assert_held(&prepare_lock);
1774
1775 if (core->parent)
1776 parent_accuracy = core->parent->accuracy;
1777
1778 if (core->ops->recalc_accuracy)
1779 core->accuracy = core->ops->recalc_accuracy(core->hw,
1780 parent_accuracy);
1781 else
1782 core->accuracy = parent_accuracy;
1783
1784 hlist_for_each_entry(child, &core->children, child_node)
1785 __clk_recalc_accuracies(child);
1786}
1787
1788static long clk_core_get_accuracy_recalc(struct clk_core *core)
1789{
1790 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
1791 __clk_recalc_accuracies(core);
1792
1793 return clk_core_get_accuracy_no_lock(core);
1794}
1795
1796/**
1797 * clk_get_accuracy - return the accuracy of clk
1798 * @clk: the clk whose accuracy is being returned
1799 *
1800 * Simply returns the cached accuracy of the clk, unless
1801 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1802 * issued.
1803 * If clk is NULL then returns 0.
1804 */
1805long clk_get_accuracy(struct clk *clk)
1806{
1807 long accuracy;
1808
1809 if (!clk)
1810 return 0;
1811
1812 clk_prepare_lock();
1813 accuracy = clk_core_get_accuracy_recalc(clk->core);
1814 clk_prepare_unlock();
1815
1816 return accuracy;
1817}
1818EXPORT_SYMBOL_GPL(clk_get_accuracy);
1819
1820static unsigned long clk_recalc(struct clk_core *core,
1821 unsigned long parent_rate)
1822{
1823 unsigned long rate = parent_rate;
1824
1825 if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
1826 rate = core->ops->recalc_rate(core->hw, parent_rate);
1827 clk_pm_runtime_put(core);
1828 }
1829 return rate;
1830}
1831
1832/**
1833 * __clk_recalc_rates
1834 * @core: first clk in the subtree
1835 * @update_req: Whether req_rate should be updated with the new rate
1836 * @msg: notification type (see include/linux/clk.h)
1837 *
1838 * Walks the subtree of clks starting with clk and recalculates rates as it
1839 * goes. Note that if a clk does not implement the .recalc_rate callback then
1840 * it is assumed that the clock will take on the rate of its parent.
1841 *
1842 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1843 * if necessary.
1844 */
1845static void __clk_recalc_rates(struct clk_core *core, bool update_req,
1846 unsigned long msg)
1847{
1848 unsigned long old_rate;
1849 unsigned long parent_rate = 0;
1850 struct clk_core *child;
1851
1852 lockdep_assert_held(&prepare_lock);
1853
1854 old_rate = core->rate;
1855
1856 if (core->parent)
1857 parent_rate = core->parent->rate;
1858
1859 core->rate = clk_recalc(core, parent_rate);
1860 if (update_req)
1861 core->req_rate = core->rate;
1862
1863 /*
1864 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1865 * & ABORT_RATE_CHANGE notifiers
1866 */
1867 if (core->notifier_count && msg)
1868 __clk_notify(core, msg, old_rate, core->rate);
1869
1870 hlist_for_each_entry(child, &core->children, child_node)
1871 __clk_recalc_rates(child, update_req, msg);
1872}
1873
1874static unsigned long clk_core_get_rate_recalc(struct clk_core *core)
1875{
1876 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1877 __clk_recalc_rates(core, false, 0);
1878
1879 return clk_core_get_rate_nolock(core);
1880}
1881
1882/**
1883 * clk_get_rate - return the rate of clk
1884 * @clk: the clk whose rate is being returned
1885 *
1886 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1887 * is set, which means a recalc_rate will be issued. Can be called regardless of
1888 * the clock enabledness. If clk is NULL, or if an error occurred, then returns
1889 * 0.
1890 */
1891unsigned long clk_get_rate(struct clk *clk)
1892{
1893 unsigned long rate;
1894
1895 if (!clk)
1896 return 0;
1897
1898 clk_prepare_lock();
1899 rate = clk_core_get_rate_recalc(clk->core);
1900 clk_prepare_unlock();
1901
1902 return rate;
1903}
1904EXPORT_SYMBOL_GPL(clk_get_rate);
1905
1906static int clk_fetch_parent_index(struct clk_core *core,
1907 struct clk_core *parent)
1908{
1909 int i;
1910
1911 if (!parent)
1912 return -EINVAL;
1913
1914 for (i = 0; i < core->num_parents; i++) {
1915 /* Found it first try! */
1916 if (core->parents[i].core == parent)
1917 return i;
1918
1919 /* Something else is here, so keep looking */
1920 if (core->parents[i].core)
1921 continue;
1922
1923 /* Maybe core hasn't been cached but the hw is all we know? */
1924 if (core->parents[i].hw) {
1925 if (core->parents[i].hw == parent->hw)
1926 break;
1927
1928 /* Didn't match, but we're expecting a clk_hw */
1929 continue;
1930 }
1931
1932 /* Maybe it hasn't been cached (clk_set_parent() path) */
1933 if (parent == clk_core_get(core, i))
1934 break;
1935
1936 /* Fallback to comparing globally unique names */
1937 if (core->parents[i].name &&
1938 !strcmp(parent->name, core->parents[i].name))
1939 break;
1940 }
1941
1942 if (i == core->num_parents)
1943 return -EINVAL;
1944
1945 core->parents[i].core = parent;
1946 return i;
1947}
1948
1949/**
1950 * clk_hw_get_parent_index - return the index of the parent clock
1951 * @hw: clk_hw associated with the clk being consumed
1952 *
1953 * Fetches and returns the index of parent clock. Returns -EINVAL if the given
1954 * clock does not have a current parent.
1955 */
1956int clk_hw_get_parent_index(struct clk_hw *hw)
1957{
1958 struct clk_hw *parent = clk_hw_get_parent(hw);
1959
1960 if (WARN_ON(parent == NULL))
1961 return -EINVAL;
1962
1963 return clk_fetch_parent_index(hw->core, parent->core);
1964}
1965EXPORT_SYMBOL_GPL(clk_hw_get_parent_index);
1966
1967/*
1968 * Update the orphan status of @core and all its children.
1969 */
1970static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
1971{
1972 struct clk_core *child;
1973
1974 core->orphan = is_orphan;
1975
1976 hlist_for_each_entry(child, &core->children, child_node)
1977 clk_core_update_orphan_status(child, is_orphan);
1978}
1979
1980static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1981{
1982 bool was_orphan = core->orphan;
1983
1984 hlist_del(&core->child_node);
1985
1986 if (new_parent) {
1987 bool becomes_orphan = new_parent->orphan;
1988
1989 /* avoid duplicate POST_RATE_CHANGE notifications */
1990 if (new_parent->new_child == core)
1991 new_parent->new_child = NULL;
1992
1993 hlist_add_head(&core->child_node, &new_parent->children);
1994
1995 if (was_orphan != becomes_orphan)
1996 clk_core_update_orphan_status(core, becomes_orphan);
1997 } else {
1998 hlist_add_head(&core->child_node, &clk_orphan_list);
1999 if (!was_orphan)
2000 clk_core_update_orphan_status(core, true);
2001 }
2002
2003 core->parent = new_parent;
2004}
2005
2006static struct clk_core *__clk_set_parent_before(struct clk_core *core,
2007 struct clk_core *parent)
2008{
2009 unsigned long flags;
2010 struct clk_core *old_parent = core->parent;
2011
2012 /*
2013 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
2014 *
2015 * 2. Migrate prepare state between parents and prevent race with
2016 * clk_enable().
2017 *
2018 * If the clock is not prepared, then a race with
2019 * clk_enable/disable() is impossible since we already have the
2020 * prepare lock (future calls to clk_enable() need to be preceded by
2021 * a clk_prepare()).
2022 *
2023 * If the clock is prepared, migrate the prepared state to the new
2024 * parent and also protect against a race with clk_enable() by
2025 * forcing the clock and the new parent on. This ensures that all
2026 * future calls to clk_enable() are practically NOPs with respect to
2027 * hardware and software states.
2028 *
2029 * See also: Comment for clk_set_parent() below.
2030 */
2031
2032 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
2033 if (core->flags & CLK_OPS_PARENT_ENABLE) {
2034 clk_core_prepare_enable(old_parent);
2035 clk_core_prepare_enable(parent);
2036 }
2037
2038 /* migrate prepare count if > 0 */
2039 if (core->prepare_count) {
2040 clk_core_prepare_enable(parent);
2041 clk_core_enable_lock(core);
2042 }
2043
2044 /* update the clk tree topology */
2045 flags = clk_enable_lock();
2046 clk_reparent(core, parent);
2047 clk_enable_unlock(flags);
2048
2049 return old_parent;
2050}
2051
2052static void __clk_set_parent_after(struct clk_core *core,
2053 struct clk_core *parent,
2054 struct clk_core *old_parent)
2055{
2056 /*
2057 * Finish the migration of prepare state and undo the changes done
2058 * for preventing a race with clk_enable().
2059 */
2060 if (core->prepare_count) {
2061 clk_core_disable_lock(core);
2062 clk_core_disable_unprepare(old_parent);
2063 }
2064
2065 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
2066 if (core->flags & CLK_OPS_PARENT_ENABLE) {
2067 clk_core_disable_unprepare(parent);
2068 clk_core_disable_unprepare(old_parent);
2069 }
2070}
2071
2072static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
2073 u8 p_index)
2074{
2075 unsigned long flags;
2076 int ret = 0;
2077 struct clk_core *old_parent;
2078
2079 old_parent = __clk_set_parent_before(core, parent);
2080
2081 trace_clk_set_parent(core, parent);
2082
2083 /* change clock input source */
2084 if (parent && core->ops->set_parent)
2085 ret = core->ops->set_parent(core->hw, p_index);
2086
2087 trace_clk_set_parent_complete(core, parent);
2088
2089 if (ret) {
2090 flags = clk_enable_lock();
2091 clk_reparent(core, old_parent);
2092 clk_enable_unlock(flags);
2093
2094 __clk_set_parent_after(core, old_parent, parent);
2095
2096 return ret;
2097 }
2098
2099 __clk_set_parent_after(core, parent, old_parent);
2100
2101 return 0;
2102}
2103
2104/**
2105 * __clk_speculate_rates
2106 * @core: first clk in the subtree
2107 * @parent_rate: the "future" rate of clk's parent
2108 *
2109 * Walks the subtree of clks starting with clk, speculating rates as it
2110 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
2111 *
2112 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
2113 * pre-rate change notifications and returns early if no clks in the
2114 * subtree have subscribed to the notifications. Note that if a clk does not
2115 * implement the .recalc_rate callback then it is assumed that the clock will
2116 * take on the rate of its parent.
2117 */
2118static int __clk_speculate_rates(struct clk_core *core,
2119 unsigned long parent_rate)
2120{
2121 struct clk_core *child;
2122 unsigned long new_rate;
2123 int ret = NOTIFY_DONE;
2124
2125 lockdep_assert_held(&prepare_lock);
2126
2127 new_rate = clk_recalc(core, parent_rate);
2128
2129 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
2130 if (core->notifier_count)
2131 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
2132
2133 if (ret & NOTIFY_STOP_MASK) {
2134 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
2135 __func__, core->name, ret);
2136 goto out;
2137 }
2138
2139 hlist_for_each_entry(child, &core->children, child_node) {
2140 ret = __clk_speculate_rates(child, new_rate);
2141 if (ret & NOTIFY_STOP_MASK)
2142 break;
2143 }
2144
2145out:
2146 return ret;
2147}
2148
2149static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
2150 struct clk_core *new_parent, u8 p_index)
2151{
2152 struct clk_core *child;
2153
2154 core->new_rate = new_rate;
2155 core->new_parent = new_parent;
2156 core->new_parent_index = p_index;
2157 /* include clk in new parent's PRE_RATE_CHANGE notifications */
2158 core->new_child = NULL;
2159 if (new_parent && new_parent != core->parent)
2160 new_parent->new_child = core;
2161
2162 hlist_for_each_entry(child, &core->children, child_node) {
2163 child->new_rate = clk_recalc(child, new_rate);
2164 clk_calc_subtree(child, child->new_rate, NULL, 0);
2165 }
2166}
2167
2168/*
2169 * calculate the new rates returning the topmost clock that has to be
2170 * changed.
2171 */
2172static struct clk_core *clk_calc_new_rates(struct clk_core *core,
2173 unsigned long rate)
2174{
2175 struct clk_core *top = core;
2176 struct clk_core *old_parent, *parent;
2177 unsigned long best_parent_rate = 0;
2178 unsigned long new_rate;
2179 unsigned long min_rate;
2180 unsigned long max_rate;
2181 int p_index = 0;
2182 long ret;
2183
2184 /* sanity */
2185 if (IS_ERR_OR_NULL(core))
2186 return NULL;
2187
2188 /* save parent rate, if it exists */
2189 parent = old_parent = core->parent;
2190 if (parent)
2191 best_parent_rate = parent->rate;
2192
2193 clk_core_get_boundaries(core, &min_rate, &max_rate);
2194
2195 /* find the closest rate and parent clk/rate */
2196 if (clk_core_can_round(core)) {
2197 struct clk_rate_request req;
2198
2199 clk_core_init_rate_req(core, &req, rate);
2200
2201 trace_clk_rate_request_start(&req);
2202
2203 ret = clk_core_determine_round_nolock(core, &req);
2204 if (ret < 0)
2205 return NULL;
2206
2207 trace_clk_rate_request_done(&req);
2208
2209 best_parent_rate = req.best_parent_rate;
2210 new_rate = req.rate;
2211 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
2212
2213 if (new_rate < min_rate || new_rate > max_rate)
2214 return NULL;
2215 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
2216 /* pass-through clock without adjustable parent */
2217 core->new_rate = core->rate;
2218 return NULL;
2219 } else {
2220 /* pass-through clock with adjustable parent */
2221 top = clk_calc_new_rates(parent, rate);
2222 new_rate = parent->new_rate;
2223 goto out;
2224 }
2225
2226 /* some clocks must be gated to change parent */
2227 if (parent != old_parent &&
2228 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
2229 pr_debug("%s: %s not gated but wants to reparent\n",
2230 __func__, core->name);
2231 return NULL;
2232 }
2233
2234 /* try finding the new parent index */
2235 if (parent && core->num_parents > 1) {
2236 p_index = clk_fetch_parent_index(core, parent);
2237 if (p_index < 0) {
2238 pr_debug("%s: clk %s can not be parent of clk %s\n",
2239 __func__, parent->name, core->name);
2240 return NULL;
2241 }
2242 }
2243
2244 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
2245 best_parent_rate != parent->rate)
2246 top = clk_calc_new_rates(parent, best_parent_rate);
2247
2248out:
2249 clk_calc_subtree(core, new_rate, parent, p_index);
2250
2251 return top;
2252}
2253
2254/*
2255 * Notify about rate changes in a subtree. Always walk down the whole tree
2256 * so that in case of an error we can walk down the whole tree again and
2257 * abort the change.
2258 */
2259static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
2260 unsigned long event)
2261{
2262 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
2263 int ret = NOTIFY_DONE;
2264
2265 if (core->rate == core->new_rate)
2266 return NULL;
2267
2268 if (core->notifier_count) {
2269 ret = __clk_notify(core, event, core->rate, core->new_rate);
2270 if (ret & NOTIFY_STOP_MASK)
2271 fail_clk = core;
2272 }
2273
2274 hlist_for_each_entry(child, &core->children, child_node) {
2275 /* Skip children who will be reparented to another clock */
2276 if (child->new_parent && child->new_parent != core)
2277 continue;
2278 tmp_clk = clk_propagate_rate_change(child, event);
2279 if (tmp_clk)
2280 fail_clk = tmp_clk;
2281 }
2282
2283 /* handle the new child who might not be in core->children yet */
2284 if (core->new_child) {
2285 tmp_clk = clk_propagate_rate_change(core->new_child, event);
2286 if (tmp_clk)
2287 fail_clk = tmp_clk;
2288 }
2289
2290 return fail_clk;
2291}
2292
2293/*
2294 * walk down a subtree and set the new rates notifying the rate
2295 * change on the way
2296 */
2297static void clk_change_rate(struct clk_core *core)
2298{
2299 struct clk_core *child;
2300 struct hlist_node *tmp;
2301 unsigned long old_rate;
2302 unsigned long best_parent_rate = 0;
2303 bool skip_set_rate = false;
2304 struct clk_core *old_parent;
2305 struct clk_core *parent = NULL;
2306
2307 old_rate = core->rate;
2308
2309 if (core->new_parent) {
2310 parent = core->new_parent;
2311 best_parent_rate = core->new_parent->rate;
2312 } else if (core->parent) {
2313 parent = core->parent;
2314 best_parent_rate = core->parent->rate;
2315 }
2316
2317 if (clk_pm_runtime_get(core))
2318 return;
2319
2320 if (core->flags & CLK_SET_RATE_UNGATE) {
2321 clk_core_prepare(core);
2322 clk_core_enable_lock(core);
2323 }
2324
2325 if (core->new_parent && core->new_parent != core->parent) {
2326 old_parent = __clk_set_parent_before(core, core->new_parent);
2327 trace_clk_set_parent(core, core->new_parent);
2328
2329 if (core->ops->set_rate_and_parent) {
2330 skip_set_rate = true;
2331 core->ops->set_rate_and_parent(core->hw, core->new_rate,
2332 best_parent_rate,
2333 core->new_parent_index);
2334 } else if (core->ops->set_parent) {
2335 core->ops->set_parent(core->hw, core->new_parent_index);
2336 }
2337
2338 trace_clk_set_parent_complete(core, core->new_parent);
2339 __clk_set_parent_after(core, core->new_parent, old_parent);
2340 }
2341
2342 if (core->flags & CLK_OPS_PARENT_ENABLE)
2343 clk_core_prepare_enable(parent);
2344
2345 trace_clk_set_rate(core, core->new_rate);
2346
2347 if (!skip_set_rate && core->ops->set_rate)
2348 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
2349
2350 trace_clk_set_rate_complete(core, core->new_rate);
2351
2352 core->rate = clk_recalc(core, best_parent_rate);
2353
2354 if (core->flags & CLK_SET_RATE_UNGATE) {
2355 clk_core_disable_lock(core);
2356 clk_core_unprepare(core);
2357 }
2358
2359 if (core->flags & CLK_OPS_PARENT_ENABLE)
2360 clk_core_disable_unprepare(parent);
2361
2362 if (core->notifier_count && old_rate != core->rate)
2363 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
2364
2365 if (core->flags & CLK_RECALC_NEW_RATES)
2366 (void)clk_calc_new_rates(core, core->new_rate);
2367
2368 /*
2369 * Use safe iteration, as change_rate can actually swap parents
2370 * for certain clock types.
2371 */
2372 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
2373 /* Skip children who will be reparented to another clock */
2374 if (child->new_parent && child->new_parent != core)
2375 continue;
2376 clk_change_rate(child);
2377 }
2378
2379 /* handle the new child who might not be in core->children yet */
2380 if (core->new_child)
2381 clk_change_rate(core->new_child);
2382
2383 clk_pm_runtime_put(core);
2384}
2385
2386static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
2387 unsigned long req_rate)
2388{
2389 int ret, cnt;
2390 struct clk_rate_request req;
2391
2392 lockdep_assert_held(&prepare_lock);
2393
2394 if (!core)
2395 return 0;
2396
2397 /* simulate what the rate would be if it could be freely set */
2398 cnt = clk_core_rate_nuke_protect(core);
2399 if (cnt < 0)
2400 return cnt;
2401
2402 clk_core_init_rate_req(core, &req, req_rate);
2403
2404 trace_clk_rate_request_start(&req);
2405
2406 ret = clk_core_round_rate_nolock(core, &req);
2407
2408 trace_clk_rate_request_done(&req);
2409
2410 /* restore the protection */
2411 clk_core_rate_restore_protect(core, cnt);
2412
2413 return ret ? 0 : req.rate;
2414}
2415
2416static int clk_core_set_rate_nolock(struct clk_core *core,
2417 unsigned long req_rate)
2418{
2419 struct clk_core *top, *fail_clk;
2420 unsigned long rate;
2421 int ret;
2422
2423 if (!core)
2424 return 0;
2425
2426 rate = clk_core_req_round_rate_nolock(core, req_rate);
2427
2428 /* bail early if nothing to do */
2429 if (rate == clk_core_get_rate_nolock(core))
2430 return 0;
2431
2432 /* fail on a direct rate set of a protected provider */
2433 if (clk_core_rate_is_protected(core))
2434 return -EBUSY;
2435
2436 /* calculate new rates and get the topmost changed clock */
2437 top = clk_calc_new_rates(core, req_rate);
2438 if (!top)
2439 return -EINVAL;
2440
2441 ret = clk_pm_runtime_get(core);
2442 if (ret)
2443 return ret;
2444
2445 /* notify that we are about to change rates */
2446 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
2447 if (fail_clk) {
2448 pr_debug("%s: failed to set %s rate\n", __func__,
2449 fail_clk->name);
2450 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
2451 ret = -EBUSY;
2452 goto err;
2453 }
2454
2455 /* change the rates */
2456 clk_change_rate(top);
2457
2458 core->req_rate = req_rate;
2459err:
2460 clk_pm_runtime_put(core);
2461
2462 return ret;
2463}
2464
2465/**
2466 * clk_set_rate - specify a new rate for clk
2467 * @clk: the clk whose rate is being changed
2468 * @rate: the new rate for clk
2469 *
2470 * In the simplest case clk_set_rate will only adjust the rate of clk.
2471 *
2472 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
2473 * propagate up to clk's parent; whether or not this happens depends on the
2474 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
2475 * after calling .round_rate then upstream parent propagation is ignored. If
2476 * *parent_rate comes back with a new rate for clk's parent then we propagate
2477 * up to clk's parent and set its rate. Upward propagation will continue
2478 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
2479 * .round_rate stops requesting changes to clk's parent_rate.
2480 *
2481 * Rate changes are accomplished via tree traversal that also recalculates the
2482 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
2483 *
2484 * Returns 0 on success, -EERROR otherwise.
2485 */
2486int clk_set_rate(struct clk *clk, unsigned long rate)
2487{
2488 int ret;
2489
2490 if (!clk)
2491 return 0;
2492
2493 /* prevent racing with updates to the clock topology */
2494 clk_prepare_lock();
2495
2496 if (clk->exclusive_count)
2497 clk_core_rate_unprotect(clk->core);
2498
2499 ret = clk_core_set_rate_nolock(clk->core, rate);
2500
2501 if (clk->exclusive_count)
2502 clk_core_rate_protect(clk->core);
2503
2504 clk_prepare_unlock();
2505
2506 return ret;
2507}
2508EXPORT_SYMBOL_GPL(clk_set_rate);
2509
2510/**
2511 * clk_set_rate_exclusive - specify a new rate and get exclusive control
2512 * @clk: the clk whose rate is being changed
2513 * @rate: the new rate for clk
2514 *
2515 * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
2516 * within a critical section
2517 *
2518 * This can be used initially to ensure that at least 1 consumer is
2519 * satisfied when several consumers are competing for exclusivity over the
2520 * same clock provider.
2521 *
2522 * The exclusivity is not applied if setting the rate failed.
2523 *
2524 * Calls to clk_rate_exclusive_get() should be balanced with calls to
2525 * clk_rate_exclusive_put().
2526 *
2527 * Returns 0 on success, -EERROR otherwise.
2528 */
2529int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
2530{
2531 int ret;
2532
2533 if (!clk)
2534 return 0;
2535
2536 /* prevent racing with updates to the clock topology */
2537 clk_prepare_lock();
2538
2539 /*
2540 * The temporary protection removal is not here, on purpose
2541 * This function is meant to be used instead of clk_rate_protect,
2542 * so before the consumer code path protect the clock provider
2543 */
2544
2545 ret = clk_core_set_rate_nolock(clk->core, rate);
2546 if (!ret) {
2547 clk_core_rate_protect(clk->core);
2548 clk->exclusive_count++;
2549 }
2550
2551 clk_prepare_unlock();
2552
2553 return ret;
2554}
2555EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
2556
2557static int clk_set_rate_range_nolock(struct clk *clk,
2558 unsigned long min,
2559 unsigned long max)
2560{
2561 int ret = 0;
2562 unsigned long old_min, old_max, rate;
2563
2564 lockdep_assert_held(&prepare_lock);
2565
2566 if (!clk)
2567 return 0;
2568
2569 trace_clk_set_rate_range(clk->core, min, max);
2570
2571 if (min > max) {
2572 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
2573 __func__, clk->core->name, clk->dev_id, clk->con_id,
2574 min, max);
2575 return -EINVAL;
2576 }
2577
2578 if (clk->exclusive_count)
2579 clk_core_rate_unprotect(clk->core);
2580
2581 /* Save the current values in case we need to rollback the change */
2582 old_min = clk->min_rate;
2583 old_max = clk->max_rate;
2584 clk->min_rate = min;
2585 clk->max_rate = max;
2586
2587 if (!clk_core_check_boundaries(clk->core, min, max)) {
2588 ret = -EINVAL;
2589 goto out;
2590 }
2591
2592 rate = clk->core->req_rate;
2593 if (clk->core->flags & CLK_GET_RATE_NOCACHE)
2594 rate = clk_core_get_rate_recalc(clk->core);
2595
2596 /*
2597 * Since the boundaries have been changed, let's give the
2598 * opportunity to the provider to adjust the clock rate based on
2599 * the new boundaries.
2600 *
2601 * We also need to handle the case where the clock is currently
2602 * outside of the boundaries. Clamping the last requested rate
2603 * to the current minimum and maximum will also handle this.
2604 *
2605 * FIXME:
2606 * There is a catch. It may fail for the usual reason (clock
2607 * broken, clock protected, etc) but also because:
2608 * - round_rate() was not favorable and fell on the wrong
2609 * side of the boundary
2610 * - the determine_rate() callback does not really check for
2611 * this corner case when determining the rate
2612 */
2613 rate = clamp(rate, min, max);
2614 ret = clk_core_set_rate_nolock(clk->core, rate);
2615 if (ret) {
2616 /* rollback the changes */
2617 clk->min_rate = old_min;
2618 clk->max_rate = old_max;
2619 }
2620
2621out:
2622 if (clk->exclusive_count)
2623 clk_core_rate_protect(clk->core);
2624
2625 return ret;
2626}
2627
2628/**
2629 * clk_set_rate_range - set a rate range for a clock source
2630 * @clk: clock source
2631 * @min: desired minimum clock rate in Hz, inclusive
2632 * @max: desired maximum clock rate in Hz, inclusive
2633 *
2634 * Return: 0 for success or negative errno on failure.
2635 */
2636int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
2637{
2638 int ret;
2639
2640 if (!clk)
2641 return 0;
2642
2643 clk_prepare_lock();
2644
2645 ret = clk_set_rate_range_nolock(clk, min, max);
2646
2647 clk_prepare_unlock();
2648
2649 return ret;
2650}
2651EXPORT_SYMBOL_GPL(clk_set_rate_range);
2652
2653/**
2654 * clk_set_min_rate - set a minimum clock rate for a clock source
2655 * @clk: clock source
2656 * @rate: desired minimum clock rate in Hz, inclusive
2657 *
2658 * Returns success (0) or negative errno.
2659 */
2660int clk_set_min_rate(struct clk *clk, unsigned long rate)
2661{
2662 if (!clk)
2663 return 0;
2664
2665 trace_clk_set_min_rate(clk->core, rate);
2666
2667 return clk_set_rate_range(clk, rate, clk->max_rate);
2668}
2669EXPORT_SYMBOL_GPL(clk_set_min_rate);
2670
2671/**
2672 * clk_set_max_rate - set a maximum clock rate for a clock source
2673 * @clk: clock source
2674 * @rate: desired maximum clock rate in Hz, inclusive
2675 *
2676 * Returns success (0) or negative errno.
2677 */
2678int clk_set_max_rate(struct clk *clk, unsigned long rate)
2679{
2680 if (!clk)
2681 return 0;
2682
2683 trace_clk_set_max_rate(clk->core, rate);
2684
2685 return clk_set_rate_range(clk, clk->min_rate, rate);
2686}
2687EXPORT_SYMBOL_GPL(clk_set_max_rate);
2688
2689/**
2690 * clk_get_parent - return the parent of a clk
2691 * @clk: the clk whose parent gets returned
2692 *
2693 * Simply returns clk->parent. Returns NULL if clk is NULL.
2694 */
2695struct clk *clk_get_parent(struct clk *clk)
2696{
2697 struct clk *parent;
2698
2699 if (!clk)
2700 return NULL;
2701
2702 clk_prepare_lock();
2703 /* TODO: Create a per-user clk and change callers to call clk_put */
2704 parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
2705 clk_prepare_unlock();
2706
2707 return parent;
2708}
2709EXPORT_SYMBOL_GPL(clk_get_parent);
2710
2711static struct clk_core *__clk_init_parent(struct clk_core *core)
2712{
2713 u8 index = 0;
2714
2715 if (core->num_parents > 1 && core->ops->get_parent)
2716 index = core->ops->get_parent(core->hw);
2717
2718 return clk_core_get_parent_by_index(core, index);
2719}
2720
2721static void clk_core_reparent(struct clk_core *core,
2722 struct clk_core *new_parent)
2723{
2724 clk_reparent(core, new_parent);
2725 __clk_recalc_accuracies(core);
2726 __clk_recalc_rates(core, true, POST_RATE_CHANGE);
2727}
2728
2729void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
2730{
2731 if (!hw)
2732 return;
2733
2734 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
2735}
2736
2737/**
2738 * clk_has_parent - check if a clock is a possible parent for another
2739 * @clk: clock source
2740 * @parent: parent clock source
2741 *
2742 * This function can be used in drivers that need to check that a clock can be
2743 * the parent of another without actually changing the parent.
2744 *
2745 * Returns true if @parent is a possible parent for @clk, false otherwise.
2746 */
2747bool clk_has_parent(const struct clk *clk, const struct clk *parent)
2748{
2749 /* NULL clocks should be nops, so return success if either is NULL. */
2750 if (!clk || !parent)
2751 return true;
2752
2753 return clk_core_has_parent(clk->core, parent->core);
2754}
2755EXPORT_SYMBOL_GPL(clk_has_parent);
2756
2757static int clk_core_set_parent_nolock(struct clk_core *core,
2758 struct clk_core *parent)
2759{
2760 int ret = 0;
2761 int p_index = 0;
2762 unsigned long p_rate = 0;
2763
2764 lockdep_assert_held(&prepare_lock);
2765
2766 if (!core)
2767 return 0;
2768
2769 if (core->parent == parent)
2770 return 0;
2771
2772 /* verify ops for multi-parent clks */
2773 if (core->num_parents > 1 && !core->ops->set_parent)
2774 return -EPERM;
2775
2776 /* check that we are allowed to re-parent if the clock is in use */
2777 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
2778 return -EBUSY;
2779
2780 if (clk_core_rate_is_protected(core))
2781 return -EBUSY;
2782
2783 /* try finding the new parent index */
2784 if (parent) {
2785 p_index = clk_fetch_parent_index(core, parent);
2786 if (p_index < 0) {
2787 pr_debug("%s: clk %s can not be parent of clk %s\n",
2788 __func__, parent->name, core->name);
2789 return p_index;
2790 }
2791 p_rate = parent->rate;
2792 }
2793
2794 ret = clk_pm_runtime_get(core);
2795 if (ret)
2796 return ret;
2797
2798 /* propagate PRE_RATE_CHANGE notifications */
2799 ret = __clk_speculate_rates(core, p_rate);
2800
2801 /* abort if a driver objects */
2802 if (ret & NOTIFY_STOP_MASK)
2803 goto runtime_put;
2804
2805 /* do the re-parent */
2806 ret = __clk_set_parent(core, parent, p_index);
2807
2808 /* propagate rate an accuracy recalculation accordingly */
2809 if (ret) {
2810 __clk_recalc_rates(core, true, ABORT_RATE_CHANGE);
2811 } else {
2812 __clk_recalc_rates(core, true, POST_RATE_CHANGE);
2813 __clk_recalc_accuracies(core);
2814 }
2815
2816runtime_put:
2817 clk_pm_runtime_put(core);
2818
2819 return ret;
2820}
2821
2822int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *parent)
2823{
2824 return clk_core_set_parent_nolock(hw->core, parent->core);
2825}
2826EXPORT_SYMBOL_GPL(clk_hw_set_parent);
2827
2828/**
2829 * clk_set_parent - switch the parent of a mux clk
2830 * @clk: the mux clk whose input we are switching
2831 * @parent: the new input to clk
2832 *
2833 * Re-parent clk to use parent as its new input source. If clk is in
2834 * prepared state, the clk will get enabled for the duration of this call. If
2835 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2836 * that, the reparenting is glitchy in hardware, etc), use the
2837 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2838 *
2839 * After successfully changing clk's parent clk_set_parent will update the
2840 * clk topology, sysfs topology and propagate rate recalculation via
2841 * __clk_recalc_rates.
2842 *
2843 * Returns 0 on success, -EERROR otherwise.
2844 */
2845int clk_set_parent(struct clk *clk, struct clk *parent)
2846{
2847 int ret;
2848
2849 if (!clk)
2850 return 0;
2851
2852 clk_prepare_lock();
2853
2854 if (clk->exclusive_count)
2855 clk_core_rate_unprotect(clk->core);
2856
2857 ret = clk_core_set_parent_nolock(clk->core,
2858 parent ? parent->core : NULL);
2859
2860 if (clk->exclusive_count)
2861 clk_core_rate_protect(clk->core);
2862
2863 clk_prepare_unlock();
2864
2865 return ret;
2866}
2867EXPORT_SYMBOL_GPL(clk_set_parent);
2868
2869static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
2870{
2871 int ret = -EINVAL;
2872
2873 lockdep_assert_held(&prepare_lock);
2874
2875 if (!core)
2876 return 0;
2877
2878 if (clk_core_rate_is_protected(core))
2879 return -EBUSY;
2880
2881 trace_clk_set_phase(core, degrees);
2882
2883 if (core->ops->set_phase) {
2884 ret = core->ops->set_phase(core->hw, degrees);
2885 if (!ret)
2886 core->phase = degrees;
2887 }
2888
2889 trace_clk_set_phase_complete(core, degrees);
2890
2891 return ret;
2892}
2893
2894/**
2895 * clk_set_phase - adjust the phase shift of a clock signal
2896 * @clk: clock signal source
2897 * @degrees: number of degrees the signal is shifted
2898 *
2899 * Shifts the phase of a clock signal by the specified
2900 * degrees. Returns 0 on success, -EERROR otherwise.
2901 *
2902 * This function makes no distinction about the input or reference
2903 * signal that we adjust the clock signal phase against. For example
2904 * phase locked-loop clock signal generators we may shift phase with
2905 * respect to feedback clock signal input, but for other cases the
2906 * clock phase may be shifted with respect to some other, unspecified
2907 * signal.
2908 *
2909 * Additionally the concept of phase shift does not propagate through
2910 * the clock tree hierarchy, which sets it apart from clock rates and
2911 * clock accuracy. A parent clock phase attribute does not have an
2912 * impact on the phase attribute of a child clock.
2913 */
2914int clk_set_phase(struct clk *clk, int degrees)
2915{
2916 int ret;
2917
2918 if (!clk)
2919 return 0;
2920
2921 /* sanity check degrees */
2922 degrees %= 360;
2923 if (degrees < 0)
2924 degrees += 360;
2925
2926 clk_prepare_lock();
2927
2928 if (clk->exclusive_count)
2929 clk_core_rate_unprotect(clk->core);
2930
2931 ret = clk_core_set_phase_nolock(clk->core, degrees);
2932
2933 if (clk->exclusive_count)
2934 clk_core_rate_protect(clk->core);
2935
2936 clk_prepare_unlock();
2937
2938 return ret;
2939}
2940EXPORT_SYMBOL_GPL(clk_set_phase);
2941
2942static int clk_core_get_phase(struct clk_core *core)
2943{
2944 int ret;
2945
2946 lockdep_assert_held(&prepare_lock);
2947 if (!core->ops->get_phase)
2948 return 0;
2949
2950 /* Always try to update cached phase if possible */
2951 ret = core->ops->get_phase(core->hw);
2952 if (ret >= 0)
2953 core->phase = ret;
2954
2955 return ret;
2956}
2957
2958/**
2959 * clk_get_phase - return the phase shift of a clock signal
2960 * @clk: clock signal source
2961 *
2962 * Returns the phase shift of a clock node in degrees, otherwise returns
2963 * -EERROR.
2964 */
2965int clk_get_phase(struct clk *clk)
2966{
2967 int ret;
2968
2969 if (!clk)
2970 return 0;
2971
2972 clk_prepare_lock();
2973 ret = clk_core_get_phase(clk->core);
2974 clk_prepare_unlock();
2975
2976 return ret;
2977}
2978EXPORT_SYMBOL_GPL(clk_get_phase);
2979
2980static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
2981{
2982 /* Assume a default value of 50% */
2983 core->duty.num = 1;
2984 core->duty.den = 2;
2985}
2986
2987static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);
2988
2989static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
2990{
2991 struct clk_duty *duty = &core->duty;
2992 int ret = 0;
2993
2994 if (!core->ops->get_duty_cycle)
2995 return clk_core_update_duty_cycle_parent_nolock(core);
2996
2997 ret = core->ops->get_duty_cycle(core->hw, duty);
2998 if (ret)
2999 goto reset;
3000
3001 /* Don't trust the clock provider too much */
3002 if (duty->den == 0 || duty->num > duty->den) {
3003 ret = -EINVAL;
3004 goto reset;
3005 }
3006
3007 return 0;
3008
3009reset:
3010 clk_core_reset_duty_cycle_nolock(core);
3011 return ret;
3012}
3013
3014static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
3015{
3016 int ret = 0;
3017
3018 if (core->parent &&
3019 core->flags & CLK_DUTY_CYCLE_PARENT) {
3020 ret = clk_core_update_duty_cycle_nolock(core->parent);
3021 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
3022 } else {
3023 clk_core_reset_duty_cycle_nolock(core);
3024 }
3025
3026 return ret;
3027}
3028
3029static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
3030 struct clk_duty *duty);
3031
3032static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
3033 struct clk_duty *duty)
3034{
3035 int ret;
3036
3037 lockdep_assert_held(&prepare_lock);
3038
3039 if (clk_core_rate_is_protected(core))
3040 return -EBUSY;
3041
3042 trace_clk_set_duty_cycle(core, duty);
3043
3044 if (!core->ops->set_duty_cycle)
3045 return clk_core_set_duty_cycle_parent_nolock(core, duty);
3046
3047 ret = core->ops->set_duty_cycle(core->hw, duty);
3048 if (!ret)
3049 memcpy(&core->duty, duty, sizeof(*duty));
3050
3051 trace_clk_set_duty_cycle_complete(core, duty);
3052
3053 return ret;
3054}
3055
3056static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
3057 struct clk_duty *duty)
3058{
3059 int ret = 0;
3060
3061 if (core->parent &&
3062 core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
3063 ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
3064 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
3065 }
3066
3067 return ret;
3068}
3069
3070/**
3071 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
3072 * @clk: clock signal source
3073 * @num: numerator of the duty cycle ratio to be applied
3074 * @den: denominator of the duty cycle ratio to be applied
3075 *
3076 * Apply the duty cycle ratio if the ratio is valid and the clock can
3077 * perform this operation
3078 *
3079 * Returns (0) on success, a negative errno otherwise.
3080 */
3081int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
3082{
3083 int ret;
3084 struct clk_duty duty;
3085
3086 if (!clk)
3087 return 0;
3088
3089 /* sanity check the ratio */
3090 if (den == 0 || num > den)
3091 return -EINVAL;
3092
3093 duty.num = num;
3094 duty.den = den;
3095
3096 clk_prepare_lock();
3097
3098 if (clk->exclusive_count)
3099 clk_core_rate_unprotect(clk->core);
3100
3101 ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
3102
3103 if (clk->exclusive_count)
3104 clk_core_rate_protect(clk->core);
3105
3106 clk_prepare_unlock();
3107
3108 return ret;
3109}
3110EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
3111
3112static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
3113 unsigned int scale)
3114{
3115 struct clk_duty *duty = &core->duty;
3116 int ret;
3117
3118 clk_prepare_lock();
3119
3120 ret = clk_core_update_duty_cycle_nolock(core);
3121 if (!ret)
3122 ret = mult_frac(scale, duty->num, duty->den);
3123
3124 clk_prepare_unlock();
3125
3126 return ret;
3127}
3128
3129/**
3130 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
3131 * @clk: clock signal source
3132 * @scale: scaling factor to be applied to represent the ratio as an integer
3133 *
3134 * Returns the duty cycle ratio of a clock node multiplied by the provided
3135 * scaling factor, or negative errno on error.
3136 */
3137int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
3138{
3139 if (!clk)
3140 return 0;
3141
3142 return clk_core_get_scaled_duty_cycle(clk->core, scale);
3143}
3144EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
3145
3146/**
3147 * clk_is_match - check if two clk's point to the same hardware clock
3148 * @p: clk compared against q
3149 * @q: clk compared against p
3150 *
3151 * Returns true if the two struct clk pointers both point to the same hardware
3152 * clock node. Put differently, returns true if struct clk *p and struct clk *q
3153 * share the same struct clk_core object.
3154 *
3155 * Returns false otherwise. Note that two NULL clks are treated as matching.
3156 */
3157bool clk_is_match(const struct clk *p, const struct clk *q)
3158{
3159 /* trivial case: identical struct clk's or both NULL */
3160 if (p == q)
3161 return true;
3162
3163 /* true if clk->core pointers match. Avoid dereferencing garbage */
3164 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
3165 if (p->core == q->core)
3166 return true;
3167
3168 return false;
3169}
3170EXPORT_SYMBOL_GPL(clk_is_match);
3171
3172/*** debugfs support ***/
3173
3174#ifdef CONFIG_DEBUG_FS
3175#include <linux/debugfs.h>
3176
3177static struct dentry *rootdir;
3178static int inited = 0;
3179static DEFINE_MUTEX(clk_debug_lock);
3180static HLIST_HEAD(clk_debug_list);
3181
3182static struct hlist_head *orphan_list[] = {
3183 &clk_orphan_list,
3184 NULL,
3185};
3186
3187static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
3188 int level)
3189{
3190 int phase;
3191 struct clk *clk_user;
3192 int multi_node = 0;
3193
3194 seq_printf(s, "%*s%-*s %-7d %-8d %-8d %-11lu %-10lu ",
3195 level * 3 + 1, "",
3196 35 - level * 3, c->name,
3197 c->enable_count, c->prepare_count, c->protect_count,
3198 clk_core_get_rate_recalc(c),
3199 clk_core_get_accuracy_recalc(c));
3200
3201 phase = clk_core_get_phase(c);
3202 if (phase >= 0)
3203 seq_printf(s, "%-5d", phase);
3204 else
3205 seq_puts(s, "-----");
3206
3207 seq_printf(s, " %-6d", clk_core_get_scaled_duty_cycle(c, 100000));
3208
3209 if (c->ops->is_enabled)
3210 seq_printf(s, " %5c ", clk_core_is_enabled(c) ? 'Y' : 'N');
3211 else if (!c->ops->enable)
3212 seq_printf(s, " %5c ", 'Y');
3213 else
3214 seq_printf(s, " %5c ", '?');
3215
3216 hlist_for_each_entry(clk_user, &c->clks, clks_node) {
3217 seq_printf(s, "%*s%-*s %-25s\n",
3218 level * 3 + 2 + 105 * multi_node, "",
3219 30,
3220 clk_user->dev_id ? clk_user->dev_id : "deviceless",
3221 clk_user->con_id ? clk_user->con_id : "no_connection_id");
3222
3223 multi_node = 1;
3224 }
3225
3226}
3227
3228static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
3229 int level)
3230{
3231 struct clk_core *child;
3232
3233 clk_pm_runtime_get(c);
3234 clk_summary_show_one(s, c, level);
3235 clk_pm_runtime_put(c);
3236
3237 hlist_for_each_entry(child, &c->children, child_node)
3238 clk_summary_show_subtree(s, child, level + 1);
3239}
3240
3241static int clk_summary_show(struct seq_file *s, void *data)
3242{
3243 struct clk_core *c;
3244 struct hlist_head **lists = s->private;
3245
3246 seq_puts(s, " enable prepare protect duty hardware connection\n");
3247 seq_puts(s, " clock count count count rate accuracy phase cycle enable consumer id\n");
3248 seq_puts(s, "---------------------------------------------------------------------------------------------------------------------------------------------\n");
3249
3250
3251 clk_prepare_lock();
3252
3253 for (; *lists; lists++)
3254 hlist_for_each_entry(c, *lists, child_node)
3255 clk_summary_show_subtree(s, c, 0);
3256
3257 clk_prepare_unlock();
3258
3259 return 0;
3260}
3261DEFINE_SHOW_ATTRIBUTE(clk_summary);
3262
3263static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
3264{
3265 int phase;
3266 unsigned long min_rate, max_rate;
3267
3268 clk_core_get_boundaries(c, &min_rate, &max_rate);
3269
3270 /* This should be JSON format, i.e. elements separated with a comma */
3271 seq_printf(s, "\"%s\": { ", c->name);
3272 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
3273 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
3274 seq_printf(s, "\"protect_count\": %d,", c->protect_count);
3275 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate_recalc(c));
3276 seq_printf(s, "\"min_rate\": %lu,", min_rate);
3277 seq_printf(s, "\"max_rate\": %lu,", max_rate);
3278 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy_recalc(c));
3279 phase = clk_core_get_phase(c);
3280 if (phase >= 0)
3281 seq_printf(s, "\"phase\": %d,", phase);
3282 seq_printf(s, "\"duty_cycle\": %u",
3283 clk_core_get_scaled_duty_cycle(c, 100000));
3284}
3285
3286static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
3287{
3288 struct clk_core *child;
3289
3290 clk_dump_one(s, c, level);
3291
3292 hlist_for_each_entry(child, &c->children, child_node) {
3293 seq_putc(s, ',');
3294 clk_dump_subtree(s, child, level + 1);
3295 }
3296
3297 seq_putc(s, '}');
3298}
3299
3300static int clk_dump_show(struct seq_file *s, void *data)
3301{
3302 struct clk_core *c;
3303 bool first_node = true;
3304 struct hlist_head **lists = s->private;
3305
3306 seq_putc(s, '{');
3307 clk_prepare_lock();
3308
3309 for (; *lists; lists++) {
3310 hlist_for_each_entry(c, *lists, child_node) {
3311 if (!first_node)
3312 seq_putc(s, ',');
3313 first_node = false;
3314 clk_dump_subtree(s, c, 0);
3315 }
3316 }
3317
3318 clk_prepare_unlock();
3319
3320 seq_puts(s, "}\n");
3321 return 0;
3322}
3323DEFINE_SHOW_ATTRIBUTE(clk_dump);
3324
3325#undef CLOCK_ALLOW_WRITE_DEBUGFS
3326#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3327/*
3328 * This can be dangerous, therefore don't provide any real compile time
3329 * configuration option for this feature.
3330 * People who want to use this will need to modify the source code directly.
3331 */
3332static int clk_rate_set(void *data, u64 val)
3333{
3334 struct clk_core *core = data;
3335 int ret;
3336
3337 clk_prepare_lock();
3338 ret = clk_core_set_rate_nolock(core, val);
3339 clk_prepare_unlock();
3340
3341 return ret;
3342}
3343
3344#define clk_rate_mode 0644
3345
3346static int clk_phase_set(void *data, u64 val)
3347{
3348 struct clk_core *core = data;
3349 int degrees = do_div(val, 360);
3350 int ret;
3351
3352 clk_prepare_lock();
3353 ret = clk_core_set_phase_nolock(core, degrees);
3354 clk_prepare_unlock();
3355
3356 return ret;
3357}
3358
3359#define clk_phase_mode 0644
3360
3361static int clk_prepare_enable_set(void *data, u64 val)
3362{
3363 struct clk_core *core = data;
3364 int ret = 0;
3365
3366 if (val)
3367 ret = clk_prepare_enable(core->hw->clk);
3368 else
3369 clk_disable_unprepare(core->hw->clk);
3370
3371 return ret;
3372}
3373
3374static int clk_prepare_enable_get(void *data, u64 *val)
3375{
3376 struct clk_core *core = data;
3377
3378 *val = core->enable_count && core->prepare_count;
3379 return 0;
3380}
3381
3382DEFINE_DEBUGFS_ATTRIBUTE(clk_prepare_enable_fops, clk_prepare_enable_get,
3383 clk_prepare_enable_set, "%llu\n");
3384
3385#else
3386#define clk_rate_set NULL
3387#define clk_rate_mode 0444
3388
3389#define clk_phase_set NULL
3390#define clk_phase_mode 0644
3391#endif
3392
3393static int clk_rate_get(void *data, u64 *val)
3394{
3395 struct clk_core *core = data;
3396
3397 clk_prepare_lock();
3398 *val = clk_core_get_rate_recalc(core);
3399 clk_prepare_unlock();
3400
3401 return 0;
3402}
3403
3404DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops, clk_rate_get, clk_rate_set, "%llu\n");
3405
3406static int clk_phase_get(void *data, u64 *val)
3407{
3408 struct clk_core *core = data;
3409
3410 *val = core->phase;
3411 return 0;
3412}
3413
3414DEFINE_DEBUGFS_ATTRIBUTE(clk_phase_fops, clk_phase_get, clk_phase_set, "%llu\n");
3415
3416static const struct {
3417 unsigned long flag;
3418 const char *name;
3419} clk_flags[] = {
3420#define ENTRY(f) { f, #f }
3421 ENTRY(CLK_SET_RATE_GATE),
3422 ENTRY(CLK_SET_PARENT_GATE),
3423 ENTRY(CLK_SET_RATE_PARENT),
3424 ENTRY(CLK_IGNORE_UNUSED),
3425 ENTRY(CLK_GET_RATE_NOCACHE),
3426 ENTRY(CLK_SET_RATE_NO_REPARENT),
3427 ENTRY(CLK_GET_ACCURACY_NOCACHE),
3428 ENTRY(CLK_RECALC_NEW_RATES),
3429 ENTRY(CLK_SET_RATE_UNGATE),
3430 ENTRY(CLK_IS_CRITICAL),
3431 ENTRY(CLK_OPS_PARENT_ENABLE),
3432 ENTRY(CLK_DUTY_CYCLE_PARENT),
3433#undef ENTRY
3434};
3435
3436static int clk_flags_show(struct seq_file *s, void *data)
3437{
3438 struct clk_core *core = s->private;
3439 unsigned long flags = core->flags;
3440 unsigned int i;
3441
3442 for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
3443 if (flags & clk_flags[i].flag) {
3444 seq_printf(s, "%s\n", clk_flags[i].name);
3445 flags &= ~clk_flags[i].flag;
3446 }
3447 }
3448 if (flags) {
3449 /* Unknown flags */
3450 seq_printf(s, "0x%lx\n", flags);
3451 }
3452
3453 return 0;
3454}
3455DEFINE_SHOW_ATTRIBUTE(clk_flags);
3456
3457static void possible_parent_show(struct seq_file *s, struct clk_core *core,
3458 unsigned int i, char terminator)
3459{
3460 struct clk_core *parent;
3461 const char *name = NULL;
3462
3463 /*
3464 * Go through the following options to fetch a parent's name.
3465 *
3466 * 1. Fetch the registered parent clock and use its name
3467 * 2. Use the global (fallback) name if specified
3468 * 3. Use the local fw_name if provided
3469 * 4. Fetch parent clock's clock-output-name if DT index was set
3470 *
3471 * This may still fail in some cases, such as when the parent is
3472 * specified directly via a struct clk_hw pointer, but it isn't
3473 * registered (yet).
3474 */
3475 parent = clk_core_get_parent_by_index(core, i);
3476 if (parent) {
3477 seq_puts(s, parent->name);
3478 } else if (core->parents[i].name) {
3479 seq_puts(s, core->parents[i].name);
3480 } else if (core->parents[i].fw_name) {
3481 seq_printf(s, "<%s>(fw)", core->parents[i].fw_name);
3482 } else {
3483 if (core->parents[i].index >= 0)
3484 name = of_clk_get_parent_name(core->of_node, core->parents[i].index);
3485 if (!name)
3486 name = "(missing)";
3487
3488 seq_puts(s, name);
3489 }
3490
3491 seq_putc(s, terminator);
3492}
3493
3494static int possible_parents_show(struct seq_file *s, void *data)
3495{
3496 struct clk_core *core = s->private;
3497 int i;
3498
3499 for (i = 0; i < core->num_parents - 1; i++)
3500 possible_parent_show(s, core, i, ' ');
3501
3502 possible_parent_show(s, core, i, '\n');
3503
3504 return 0;
3505}
3506DEFINE_SHOW_ATTRIBUTE(possible_parents);
3507
3508static int current_parent_show(struct seq_file *s, void *data)
3509{
3510 struct clk_core *core = s->private;
3511
3512 if (core->parent)
3513 seq_printf(s, "%s\n", core->parent->name);
3514
3515 return 0;
3516}
3517DEFINE_SHOW_ATTRIBUTE(current_parent);
3518
3519#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3520static ssize_t current_parent_write(struct file *file, const char __user *ubuf,
3521 size_t count, loff_t *ppos)
3522{
3523 struct seq_file *s = file->private_data;
3524 struct clk_core *core = s->private;
3525 struct clk_core *parent;
3526 u8 idx;
3527 int err;
3528
3529 err = kstrtou8_from_user(ubuf, count, 0, &idx);
3530 if (err < 0)
3531 return err;
3532
3533 parent = clk_core_get_parent_by_index(core, idx);
3534 if (!parent)
3535 return -ENOENT;
3536
3537 clk_prepare_lock();
3538 err = clk_core_set_parent_nolock(core, parent);
3539 clk_prepare_unlock();
3540 if (err)
3541 return err;
3542
3543 return count;
3544}
3545
3546static const struct file_operations current_parent_rw_fops = {
3547 .open = current_parent_open,
3548 .write = current_parent_write,
3549 .read = seq_read,
3550 .llseek = seq_lseek,
3551 .release = single_release,
3552};
3553#endif
3554
3555static int clk_duty_cycle_show(struct seq_file *s, void *data)
3556{
3557 struct clk_core *core = s->private;
3558 struct clk_duty *duty = &core->duty;
3559
3560 seq_printf(s, "%u/%u\n", duty->num, duty->den);
3561
3562 return 0;
3563}
3564DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
3565
3566static int clk_min_rate_show(struct seq_file *s, void *data)
3567{
3568 struct clk_core *core = s->private;
3569 unsigned long min_rate, max_rate;
3570
3571 clk_prepare_lock();
3572 clk_core_get_boundaries(core, &min_rate, &max_rate);
3573 clk_prepare_unlock();
3574 seq_printf(s, "%lu\n", min_rate);
3575
3576 return 0;
3577}
3578DEFINE_SHOW_ATTRIBUTE(clk_min_rate);
3579
3580static int clk_max_rate_show(struct seq_file *s, void *data)
3581{
3582 struct clk_core *core = s->private;
3583 unsigned long min_rate, max_rate;
3584
3585 clk_prepare_lock();
3586 clk_core_get_boundaries(core, &min_rate, &max_rate);
3587 clk_prepare_unlock();
3588 seq_printf(s, "%lu\n", max_rate);
3589
3590 return 0;
3591}
3592DEFINE_SHOW_ATTRIBUTE(clk_max_rate);
3593
3594static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
3595{
3596 struct dentry *root;
3597
3598 if (!core || !pdentry)
3599 return;
3600
3601 root = debugfs_create_dir(core->name, pdentry);
3602 core->dentry = root;
3603
3604 debugfs_create_file("clk_rate", clk_rate_mode, root, core,
3605 &clk_rate_fops);
3606 debugfs_create_file("clk_min_rate", 0444, root, core, &clk_min_rate_fops);
3607 debugfs_create_file("clk_max_rate", 0444, root, core, &clk_max_rate_fops);
3608 debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
3609 debugfs_create_file("clk_phase", clk_phase_mode, root, core,
3610 &clk_phase_fops);
3611 debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
3612 debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
3613 debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
3614 debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
3615 debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
3616 debugfs_create_file("clk_duty_cycle", 0444, root, core,
3617 &clk_duty_cycle_fops);
3618#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3619 debugfs_create_file("clk_prepare_enable", 0644, root, core,
3620 &clk_prepare_enable_fops);
3621
3622 if (core->num_parents > 1)
3623 debugfs_create_file("clk_parent", 0644, root, core,
3624 ¤t_parent_rw_fops);
3625 else
3626#endif
3627 if (core->num_parents > 0)
3628 debugfs_create_file("clk_parent", 0444, root, core,
3629 ¤t_parent_fops);
3630
3631 if (core->num_parents > 1)
3632 debugfs_create_file("clk_possible_parents", 0444, root, core,
3633 &possible_parents_fops);
3634
3635 if (core->ops->debug_init)
3636 core->ops->debug_init(core->hw, core->dentry);
3637}
3638
3639/**
3640 * clk_debug_register - add a clk node to the debugfs clk directory
3641 * @core: the clk being added to the debugfs clk directory
3642 *
3643 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
3644 * initialized. Otherwise it bails out early since the debugfs clk directory
3645 * will be created lazily by clk_debug_init as part of a late_initcall.
3646 */
3647static void clk_debug_register(struct clk_core *core)
3648{
3649 mutex_lock(&clk_debug_lock);
3650 hlist_add_head(&core->debug_node, &clk_debug_list);
3651 if (inited)
3652 clk_debug_create_one(core, rootdir);
3653 mutex_unlock(&clk_debug_lock);
3654}
3655
3656 /**
3657 * clk_debug_unregister - remove a clk node from the debugfs clk directory
3658 * @core: the clk being removed from the debugfs clk directory
3659 *
3660 * Dynamically removes a clk and all its child nodes from the
3661 * debugfs clk directory if clk->dentry points to debugfs created by
3662 * clk_debug_register in __clk_core_init.
3663 */
3664static void clk_debug_unregister(struct clk_core *core)
3665{
3666 mutex_lock(&clk_debug_lock);
3667 hlist_del_init(&core->debug_node);
3668 debugfs_remove_recursive(core->dentry);
3669 core->dentry = NULL;
3670 mutex_unlock(&clk_debug_lock);
3671}
3672
3673/**
3674 * clk_debug_init - lazily populate the debugfs clk directory
3675 *
3676 * clks are often initialized very early during boot before memory can be
3677 * dynamically allocated and well before debugfs is setup. This function
3678 * populates the debugfs clk directory once at boot-time when we know that
3679 * debugfs is setup. It should only be called once at boot-time, all other clks
3680 * added dynamically will be done so with clk_debug_register.
3681 */
3682static int __init clk_debug_init(void)
3683{
3684 struct clk_core *core;
3685
3686#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3687 pr_warn("\n");
3688 pr_warn("********************************************************************\n");
3689 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
3690 pr_warn("** **\n");
3691 pr_warn("** WRITEABLE clk DebugFS SUPPORT HAS BEEN ENABLED IN THIS KERNEL **\n");
3692 pr_warn("** **\n");
3693 pr_warn("** This means that this kernel is built to expose clk operations **\n");
3694 pr_warn("** such as parent or rate setting, enabling, disabling, etc. **\n");
3695 pr_warn("** to userspace, which may compromise security on your system. **\n");
3696 pr_warn("** **\n");
3697 pr_warn("** If you see this message and you are not debugging the **\n");
3698 pr_warn("** kernel, report this immediately to your vendor! **\n");
3699 pr_warn("** **\n");
3700 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
3701 pr_warn("********************************************************************\n");
3702#endif
3703
3704 rootdir = debugfs_create_dir("clk", NULL);
3705
3706 debugfs_create_file("clk_summary", 0444, rootdir, &all_lists,
3707 &clk_summary_fops);
3708 debugfs_create_file("clk_dump", 0444, rootdir, &all_lists,
3709 &clk_dump_fops);
3710 debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list,
3711 &clk_summary_fops);
3712 debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list,
3713 &clk_dump_fops);
3714
3715 mutex_lock(&clk_debug_lock);
3716 hlist_for_each_entry(core, &clk_debug_list, debug_node)
3717 clk_debug_create_one(core, rootdir);
3718
3719 inited = 1;
3720 mutex_unlock(&clk_debug_lock);
3721
3722 return 0;
3723}
3724late_initcall(clk_debug_init);
3725#else
3726static inline void clk_debug_register(struct clk_core *core) { }
3727static inline void clk_debug_unregister(struct clk_core *core)
3728{
3729}
3730#endif
3731
3732static void clk_core_reparent_orphans_nolock(void)
3733{
3734 struct clk_core *orphan;
3735 struct hlist_node *tmp2;
3736
3737 /*
3738 * walk the list of orphan clocks and reparent any that newly finds a
3739 * parent.
3740 */
3741 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
3742 struct clk_core *parent = __clk_init_parent(orphan);
3743
3744 /*
3745 * We need to use __clk_set_parent_before() and _after() to
3746 * properly migrate any prepare/enable count of the orphan
3747 * clock. This is important for CLK_IS_CRITICAL clocks, which
3748 * are enabled during init but might not have a parent yet.
3749 */
3750 if (parent) {
3751 /* update the clk tree topology */
3752 __clk_set_parent_before(orphan, parent);
3753 __clk_set_parent_after(orphan, parent, NULL);
3754 __clk_recalc_accuracies(orphan);
3755 __clk_recalc_rates(orphan, true, 0);
3756
3757 /*
3758 * __clk_init_parent() will set the initial req_rate to
3759 * 0 if the clock doesn't have clk_ops::recalc_rate and
3760 * is an orphan when it's registered.
3761 *
3762 * 'req_rate' is used by clk_set_rate_range() and
3763 * clk_put() to trigger a clk_set_rate() call whenever
3764 * the boundaries are modified. Let's make sure
3765 * 'req_rate' is set to something non-zero so that
3766 * clk_set_rate_range() doesn't drop the frequency.
3767 */
3768 orphan->req_rate = orphan->rate;
3769 }
3770 }
3771}
3772
3773/**
3774 * __clk_core_init - initialize the data structures in a struct clk_core
3775 * @core: clk_core being initialized
3776 *
3777 * Initializes the lists in struct clk_core, queries the hardware for the
3778 * parent and rate and sets them both.
3779 */
3780static int __clk_core_init(struct clk_core *core)
3781{
3782 int ret;
3783 struct clk_core *parent;
3784 unsigned long rate;
3785 int phase;
3786
3787 clk_prepare_lock();
3788
3789 /*
3790 * Set hw->core after grabbing the prepare_lock to synchronize with
3791 * callers of clk_core_fill_parent_index() where we treat hw->core
3792 * being NULL as the clk not being registered yet. This is crucial so
3793 * that clks aren't parented until their parent is fully registered.
3794 */
3795 core->hw->core = core;
3796
3797 ret = clk_pm_runtime_get(core);
3798 if (ret)
3799 goto unlock;
3800
3801 /* check to see if a clock with this name is already registered */
3802 if (clk_core_lookup(core->name)) {
3803 pr_debug("%s: clk %s already initialized\n",
3804 __func__, core->name);
3805 ret = -EEXIST;
3806 goto out;
3807 }
3808
3809 /* check that clk_ops are sane. See Documentation/driver-api/clk.rst */
3810 if (core->ops->set_rate &&
3811 !((core->ops->round_rate || core->ops->determine_rate) &&
3812 core->ops->recalc_rate)) {
3813 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
3814 __func__, core->name);
3815 ret = -EINVAL;
3816 goto out;
3817 }
3818
3819 if (core->ops->set_parent && !core->ops->get_parent) {
3820 pr_err("%s: %s must implement .get_parent & .set_parent\n",
3821 __func__, core->name);
3822 ret = -EINVAL;
3823 goto out;
3824 }
3825
3826 if (core->ops->set_parent && !core->ops->determine_rate) {
3827 pr_err("%s: %s must implement .set_parent & .determine_rate\n",
3828 __func__, core->name);
3829 ret = -EINVAL;
3830 goto out;
3831 }
3832
3833 if (core->num_parents > 1 && !core->ops->get_parent) {
3834 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
3835 __func__, core->name);
3836 ret = -EINVAL;
3837 goto out;
3838 }
3839
3840 if (core->ops->set_rate_and_parent &&
3841 !(core->ops->set_parent && core->ops->set_rate)) {
3842 pr_err("%s: %s must implement .set_parent & .set_rate\n",
3843 __func__, core->name);
3844 ret = -EINVAL;
3845 goto out;
3846 }
3847
3848 /*
3849 * optional platform-specific magic
3850 *
3851 * The .init callback is not used by any of the basic clock types, but
3852 * exists for weird hardware that must perform initialization magic for
3853 * CCF to get an accurate view of clock for any other callbacks. It may
3854 * also be used needs to perform dynamic allocations. Such allocation
3855 * must be freed in the terminate() callback.
3856 * This callback shall not be used to initialize the parameters state,
3857 * such as rate, parent, etc ...
3858 *
3859 * If it exist, this callback should called before any other callback of
3860 * the clock
3861 */
3862 if (core->ops->init) {
3863 ret = core->ops->init(core->hw);
3864 if (ret)
3865 goto out;
3866 }
3867
3868 parent = core->parent = __clk_init_parent(core);
3869
3870 /*
3871 * Populate core->parent if parent has already been clk_core_init'd. If
3872 * parent has not yet been clk_core_init'd then place clk in the orphan
3873 * list. If clk doesn't have any parents then place it in the root
3874 * clk list.
3875 *
3876 * Every time a new clk is clk_init'd then we walk the list of orphan
3877 * clocks and re-parent any that are children of the clock currently
3878 * being clk_init'd.
3879 */
3880 if (parent) {
3881 hlist_add_head(&core->child_node, &parent->children);
3882 core->orphan = parent->orphan;
3883 } else if (!core->num_parents) {
3884 hlist_add_head(&core->child_node, &clk_root_list);
3885 core->orphan = false;
3886 } else {
3887 hlist_add_head(&core->child_node, &clk_orphan_list);
3888 core->orphan = true;
3889 }
3890
3891 /*
3892 * Set clk's accuracy. The preferred method is to use
3893 * .recalc_accuracy. For simple clocks and lazy developers the default
3894 * fallback is to use the parent's accuracy. If a clock doesn't have a
3895 * parent (or is orphaned) then accuracy is set to zero (perfect
3896 * clock).
3897 */
3898 if (core->ops->recalc_accuracy)
3899 core->accuracy = core->ops->recalc_accuracy(core->hw,
3900 clk_core_get_accuracy_no_lock(parent));
3901 else if (parent)
3902 core->accuracy = parent->accuracy;
3903 else
3904 core->accuracy = 0;
3905
3906 /*
3907 * Set clk's phase by clk_core_get_phase() caching the phase.
3908 * Since a phase is by definition relative to its parent, just
3909 * query the current clock phase, or just assume it's in phase.
3910 */
3911 phase = clk_core_get_phase(core);
3912 if (phase < 0) {
3913 ret = phase;
3914 pr_warn("%s: Failed to get phase for clk '%s'\n", __func__,
3915 core->name);
3916 goto out;
3917 }
3918
3919 /*
3920 * Set clk's duty cycle.
3921 */
3922 clk_core_update_duty_cycle_nolock(core);
3923
3924 /*
3925 * Set clk's rate. The preferred method is to use .recalc_rate. For
3926 * simple clocks and lazy developers the default fallback is to use the
3927 * parent's rate. If a clock doesn't have a parent (or is orphaned)
3928 * then rate is set to zero.
3929 */
3930 if (core->ops->recalc_rate)
3931 rate = core->ops->recalc_rate(core->hw,
3932 clk_core_get_rate_nolock(parent));
3933 else if (parent)
3934 rate = parent->rate;
3935 else
3936 rate = 0;
3937 core->rate = core->req_rate = rate;
3938
3939 /*
3940 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
3941 * don't get accidentally disabled when walking the orphan tree and
3942 * reparenting clocks
3943 */
3944 if (core->flags & CLK_IS_CRITICAL) {
3945 ret = clk_core_prepare(core);
3946 if (ret) {
3947 pr_warn("%s: critical clk '%s' failed to prepare\n",
3948 __func__, core->name);
3949 goto out;
3950 }
3951
3952 ret = clk_core_enable_lock(core);
3953 if (ret) {
3954 pr_warn("%s: critical clk '%s' failed to enable\n",
3955 __func__, core->name);
3956 clk_core_unprepare(core);
3957 goto out;
3958 }
3959 }
3960
3961 clk_core_reparent_orphans_nolock();
3962
3963 kref_init(&core->ref);
3964out:
3965 clk_pm_runtime_put(core);
3966unlock:
3967 if (ret) {
3968 hlist_del_init(&core->child_node);
3969 core->hw->core = NULL;
3970 }
3971
3972 clk_prepare_unlock();
3973
3974 if (!ret)
3975 clk_debug_register(core);
3976
3977 return ret;
3978}
3979
3980/**
3981 * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core
3982 * @core: clk to add consumer to
3983 * @clk: consumer to link to a clk
3984 */
3985static void clk_core_link_consumer(struct clk_core *core, struct clk *clk)
3986{
3987 clk_prepare_lock();
3988 hlist_add_head(&clk->clks_node, &core->clks);
3989 clk_prepare_unlock();
3990}
3991
3992/**
3993 * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core
3994 * @clk: consumer to unlink
3995 */
3996static void clk_core_unlink_consumer(struct clk *clk)
3997{
3998 lockdep_assert_held(&prepare_lock);
3999 hlist_del(&clk->clks_node);
4000}
4001
4002/**
4003 * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core
4004 * @core: clk to allocate a consumer for
4005 * @dev_id: string describing device name
4006 * @con_id: connection ID string on device
4007 *
4008 * Returns: clk consumer left unlinked from the consumer list
4009 */
4010static struct clk *alloc_clk(struct clk_core *core, const char *dev_id,
4011 const char *con_id)
4012{
4013 struct clk *clk;
4014
4015 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
4016 if (!clk)
4017 return ERR_PTR(-ENOMEM);
4018
4019 clk->core = core;
4020 clk->dev_id = dev_id;
4021 clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
4022 clk->max_rate = ULONG_MAX;
4023
4024 return clk;
4025}
4026
4027/**
4028 * free_clk - Free a clk consumer
4029 * @clk: clk consumer to free
4030 *
4031 * Note, this assumes the clk has been unlinked from the clk_core consumer
4032 * list.
4033 */
4034static void free_clk(struct clk *clk)
4035{
4036 kfree_const(clk->con_id);
4037 kfree(clk);
4038}
4039
4040/**
4041 * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given
4042 * a clk_hw
4043 * @dev: clk consumer device
4044 * @hw: clk_hw associated with the clk being consumed
4045 * @dev_id: string describing device name
4046 * @con_id: connection ID string on device
4047 *
4048 * This is the main function used to create a clk pointer for use by clk
4049 * consumers. It connects a consumer to the clk_core and clk_hw structures
4050 * used by the framework and clk provider respectively.
4051 */
4052struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
4053 const char *dev_id, const char *con_id)
4054{
4055 struct clk *clk;
4056 struct clk_core *core;
4057
4058 /* This is to allow this function to be chained to others */
4059 if (IS_ERR_OR_NULL(hw))
4060 return ERR_CAST(hw);
4061
4062 core = hw->core;
4063 clk = alloc_clk(core, dev_id, con_id);
4064 if (IS_ERR(clk))
4065 return clk;
4066 clk->dev = dev;
4067
4068 if (!try_module_get(core->owner)) {
4069 free_clk(clk);
4070 return ERR_PTR(-ENOENT);
4071 }
4072
4073 kref_get(&core->ref);
4074 clk_core_link_consumer(core, clk);
4075
4076 return clk;
4077}
4078
4079/**
4080 * clk_hw_get_clk - get clk consumer given an clk_hw
4081 * @hw: clk_hw associated with the clk being consumed
4082 * @con_id: connection ID string on device
4083 *
4084 * Returns: new clk consumer
4085 * This is the function to be used by providers which need
4086 * to get a consumer clk and act on the clock element
4087 * Calls to this function must be balanced with calls clk_put()
4088 */
4089struct clk *clk_hw_get_clk(struct clk_hw *hw, const char *con_id)
4090{
4091 struct device *dev = hw->core->dev;
4092 const char *name = dev ? dev_name(dev) : NULL;
4093
4094 return clk_hw_create_clk(dev, hw, name, con_id);
4095}
4096EXPORT_SYMBOL(clk_hw_get_clk);
4097
4098static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
4099{
4100 const char *dst;
4101
4102 if (!src) {
4103 if (must_exist)
4104 return -EINVAL;
4105 return 0;
4106 }
4107
4108 *dst_p = dst = kstrdup_const(src, GFP_KERNEL);
4109 if (!dst)
4110 return -ENOMEM;
4111
4112 return 0;
4113}
4114
4115static int clk_core_populate_parent_map(struct clk_core *core,
4116 const struct clk_init_data *init)
4117{
4118 u8 num_parents = init->num_parents;
4119 const char * const *parent_names = init->parent_names;
4120 const struct clk_hw **parent_hws = init->parent_hws;
4121 const struct clk_parent_data *parent_data = init->parent_data;
4122 int i, ret = 0;
4123 struct clk_parent_map *parents, *parent;
4124
4125 if (!num_parents)
4126 return 0;
4127
4128 /*
4129 * Avoid unnecessary string look-ups of clk_core's possible parents by
4130 * having a cache of names/clk_hw pointers to clk_core pointers.
4131 */
4132 parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
4133 core->parents = parents;
4134 if (!parents)
4135 return -ENOMEM;
4136
4137 /* Copy everything over because it might be __initdata */
4138 for (i = 0, parent = parents; i < num_parents; i++, parent++) {
4139 parent->index = -1;
4140 if (parent_names) {
4141 /* throw a WARN if any entries are NULL */
4142 WARN(!parent_names[i],
4143 "%s: invalid NULL in %s's .parent_names\n",
4144 __func__, core->name);
4145 ret = clk_cpy_name(&parent->name, parent_names[i],
4146 true);
4147 } else if (parent_data) {
4148 parent->hw = parent_data[i].hw;
4149 parent->index = parent_data[i].index;
4150 ret = clk_cpy_name(&parent->fw_name,
4151 parent_data[i].fw_name, false);
4152 if (!ret)
4153 ret = clk_cpy_name(&parent->name,
4154 parent_data[i].name,
4155 false);
4156 } else if (parent_hws) {
4157 parent->hw = parent_hws[i];
4158 } else {
4159 ret = -EINVAL;
4160 WARN(1, "Must specify parents if num_parents > 0\n");
4161 }
4162
4163 if (ret) {
4164 do {
4165 kfree_const(parents[i].name);
4166 kfree_const(parents[i].fw_name);
4167 } while (--i >= 0);
4168 kfree(parents);
4169
4170 return ret;
4171 }
4172 }
4173
4174 return 0;
4175}
4176
4177static void clk_core_free_parent_map(struct clk_core *core)
4178{
4179 int i = core->num_parents;
4180
4181 if (!core->num_parents)
4182 return;
4183
4184 while (--i >= 0) {
4185 kfree_const(core->parents[i].name);
4186 kfree_const(core->parents[i].fw_name);
4187 }
4188
4189 kfree(core->parents);
4190}
4191
4192static struct clk *
4193__clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
4194{
4195 int ret;
4196 struct clk_core *core;
4197 const struct clk_init_data *init = hw->init;
4198
4199 /*
4200 * The init data is not supposed to be used outside of registration path.
4201 * Set it to NULL so that provider drivers can't use it either and so that
4202 * we catch use of hw->init early on in the core.
4203 */
4204 hw->init = NULL;
4205
4206 core = kzalloc(sizeof(*core), GFP_KERNEL);
4207 if (!core) {
4208 ret = -ENOMEM;
4209 goto fail_out;
4210 }
4211
4212 core->name = kstrdup_const(init->name, GFP_KERNEL);
4213 if (!core->name) {
4214 ret = -ENOMEM;
4215 goto fail_name;
4216 }
4217
4218 if (WARN_ON(!init->ops)) {
4219 ret = -EINVAL;
4220 goto fail_ops;
4221 }
4222 core->ops = init->ops;
4223
4224 if (dev && pm_runtime_enabled(dev))
4225 core->rpm_enabled = true;
4226 core->dev = dev;
4227 core->of_node = np;
4228 if (dev && dev->driver)
4229 core->owner = dev->driver->owner;
4230 core->hw = hw;
4231 core->flags = init->flags;
4232 core->num_parents = init->num_parents;
4233 core->min_rate = 0;
4234 core->max_rate = ULONG_MAX;
4235
4236 ret = clk_core_populate_parent_map(core, init);
4237 if (ret)
4238 goto fail_parents;
4239
4240 INIT_HLIST_HEAD(&core->clks);
4241
4242 /*
4243 * Don't call clk_hw_create_clk() here because that would pin the
4244 * provider module to itself and prevent it from ever being removed.
4245 */
4246 hw->clk = alloc_clk(core, NULL, NULL);
4247 if (IS_ERR(hw->clk)) {
4248 ret = PTR_ERR(hw->clk);
4249 goto fail_create_clk;
4250 }
4251
4252 clk_core_link_consumer(core, hw->clk);
4253
4254 ret = __clk_core_init(core);
4255 if (!ret)
4256 return hw->clk;
4257
4258 clk_prepare_lock();
4259 clk_core_unlink_consumer(hw->clk);
4260 clk_prepare_unlock();
4261
4262 free_clk(hw->clk);
4263 hw->clk = NULL;
4264
4265fail_create_clk:
4266 clk_core_free_parent_map(core);
4267fail_parents:
4268fail_ops:
4269 kfree_const(core->name);
4270fail_name:
4271 kfree(core);
4272fail_out:
4273 return ERR_PTR(ret);
4274}
4275
4276/**
4277 * dev_or_parent_of_node() - Get device node of @dev or @dev's parent
4278 * @dev: Device to get device node of
4279 *
4280 * Return: device node pointer of @dev, or the device node pointer of
4281 * @dev->parent if dev doesn't have a device node, or NULL if neither
4282 * @dev or @dev->parent have a device node.
4283 */
4284static struct device_node *dev_or_parent_of_node(struct device *dev)
4285{
4286 struct device_node *np;
4287
4288 if (!dev)
4289 return NULL;
4290
4291 np = dev_of_node(dev);
4292 if (!np)
4293 np = dev_of_node(dev->parent);
4294
4295 return np;
4296}
4297
4298/**
4299 * clk_register - allocate a new clock, register it and return an opaque cookie
4300 * @dev: device that is registering this clock
4301 * @hw: link to hardware-specific clock data
4302 *
4303 * clk_register is the *deprecated* interface for populating the clock tree with
4304 * new clock nodes. Use clk_hw_register() instead.
4305 *
4306 * Returns: a pointer to the newly allocated struct clk which
4307 * cannot be dereferenced by driver code but may be used in conjunction with the
4308 * rest of the clock API. In the event of an error clk_register will return an
4309 * error code; drivers must test for an error code after calling clk_register.
4310 */
4311struct clk *clk_register(struct device *dev, struct clk_hw *hw)
4312{
4313 return __clk_register(dev, dev_or_parent_of_node(dev), hw);
4314}
4315EXPORT_SYMBOL_GPL(clk_register);
4316
4317/**
4318 * clk_hw_register - register a clk_hw and return an error code
4319 * @dev: device that is registering this clock
4320 * @hw: link to hardware-specific clock data
4321 *
4322 * clk_hw_register is the primary interface for populating the clock tree with
4323 * new clock nodes. It returns an integer equal to zero indicating success or
4324 * less than zero indicating failure. Drivers must test for an error code after
4325 * calling clk_hw_register().
4326 */
4327int clk_hw_register(struct device *dev, struct clk_hw *hw)
4328{
4329 return PTR_ERR_OR_ZERO(__clk_register(dev, dev_or_parent_of_node(dev),
4330 hw));
4331}
4332EXPORT_SYMBOL_GPL(clk_hw_register);
4333
4334/*
4335 * of_clk_hw_register - register a clk_hw and return an error code
4336 * @node: device_node of device that is registering this clock
4337 * @hw: link to hardware-specific clock data
4338 *
4339 * of_clk_hw_register() is the primary interface for populating the clock tree
4340 * with new clock nodes when a struct device is not available, but a struct
4341 * device_node is. It returns an integer equal to zero indicating success or
4342 * less than zero indicating failure. Drivers must test for an error code after
4343 * calling of_clk_hw_register().
4344 */
4345int of_clk_hw_register(struct device_node *node, struct clk_hw *hw)
4346{
4347 return PTR_ERR_OR_ZERO(__clk_register(NULL, node, hw));
4348}
4349EXPORT_SYMBOL_GPL(of_clk_hw_register);
4350
4351/* Free memory allocated for a clock. */
4352static void __clk_release(struct kref *ref)
4353{
4354 struct clk_core *core = container_of(ref, struct clk_core, ref);
4355
4356 lockdep_assert_held(&prepare_lock);
4357
4358 clk_core_free_parent_map(core);
4359 kfree_const(core->name);
4360 kfree(core);
4361}
4362
4363/*
4364 * Empty clk_ops for unregistered clocks. These are used temporarily
4365 * after clk_unregister() was called on a clock and until last clock
4366 * consumer calls clk_put() and the struct clk object is freed.
4367 */
4368static int clk_nodrv_prepare_enable(struct clk_hw *hw)
4369{
4370 return -ENXIO;
4371}
4372
4373static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
4374{
4375 WARN_ON_ONCE(1);
4376}
4377
4378static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
4379 unsigned long parent_rate)
4380{
4381 return -ENXIO;
4382}
4383
4384static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
4385{
4386 return -ENXIO;
4387}
4388
4389static int clk_nodrv_determine_rate(struct clk_hw *hw,
4390 struct clk_rate_request *req)
4391{
4392 return -ENXIO;
4393}
4394
4395static const struct clk_ops clk_nodrv_ops = {
4396 .enable = clk_nodrv_prepare_enable,
4397 .disable = clk_nodrv_disable_unprepare,
4398 .prepare = clk_nodrv_prepare_enable,
4399 .unprepare = clk_nodrv_disable_unprepare,
4400 .determine_rate = clk_nodrv_determine_rate,
4401 .set_rate = clk_nodrv_set_rate,
4402 .set_parent = clk_nodrv_set_parent,
4403};
4404
4405static void clk_core_evict_parent_cache_subtree(struct clk_core *root,
4406 const struct clk_core *target)
4407{
4408 int i;
4409 struct clk_core *child;
4410
4411 for (i = 0; i < root->num_parents; i++)
4412 if (root->parents[i].core == target)
4413 root->parents[i].core = NULL;
4414
4415 hlist_for_each_entry(child, &root->children, child_node)
4416 clk_core_evict_parent_cache_subtree(child, target);
4417}
4418
4419/* Remove this clk from all parent caches */
4420static void clk_core_evict_parent_cache(struct clk_core *core)
4421{
4422 const struct hlist_head **lists;
4423 struct clk_core *root;
4424
4425 lockdep_assert_held(&prepare_lock);
4426
4427 for (lists = all_lists; *lists; lists++)
4428 hlist_for_each_entry(root, *lists, child_node)
4429 clk_core_evict_parent_cache_subtree(root, core);
4430
4431}
4432
4433/**
4434 * clk_unregister - unregister a currently registered clock
4435 * @clk: clock to unregister
4436 */
4437void clk_unregister(struct clk *clk)
4438{
4439 unsigned long flags;
4440 const struct clk_ops *ops;
4441
4442 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4443 return;
4444
4445 clk_debug_unregister(clk->core);
4446
4447 clk_prepare_lock();
4448
4449 ops = clk->core->ops;
4450 if (ops == &clk_nodrv_ops) {
4451 pr_err("%s: unregistered clock: %s\n", __func__,
4452 clk->core->name);
4453 goto unlock;
4454 }
4455 /*
4456 * Assign empty clock ops for consumers that might still hold
4457 * a reference to this clock.
4458 */
4459 flags = clk_enable_lock();
4460 clk->core->ops = &clk_nodrv_ops;
4461 clk_enable_unlock(flags);
4462
4463 if (ops->terminate)
4464 ops->terminate(clk->core->hw);
4465
4466 if (!hlist_empty(&clk->core->children)) {
4467 struct clk_core *child;
4468 struct hlist_node *t;
4469
4470 /* Reparent all children to the orphan list. */
4471 hlist_for_each_entry_safe(child, t, &clk->core->children,
4472 child_node)
4473 clk_core_set_parent_nolock(child, NULL);
4474 }
4475
4476 clk_core_evict_parent_cache(clk->core);
4477
4478 hlist_del_init(&clk->core->child_node);
4479
4480 if (clk->core->prepare_count)
4481 pr_warn("%s: unregistering prepared clock: %s\n",
4482 __func__, clk->core->name);
4483
4484 if (clk->core->protect_count)
4485 pr_warn("%s: unregistering protected clock: %s\n",
4486 __func__, clk->core->name);
4487
4488 kref_put(&clk->core->ref, __clk_release);
4489 free_clk(clk);
4490unlock:
4491 clk_prepare_unlock();
4492}
4493EXPORT_SYMBOL_GPL(clk_unregister);
4494
4495/**
4496 * clk_hw_unregister - unregister a currently registered clk_hw
4497 * @hw: hardware-specific clock data to unregister
4498 */
4499void clk_hw_unregister(struct clk_hw *hw)
4500{
4501 clk_unregister(hw->clk);
4502}
4503EXPORT_SYMBOL_GPL(clk_hw_unregister);
4504
4505static void devm_clk_unregister_cb(struct device *dev, void *res)
4506{
4507 clk_unregister(*(struct clk **)res);
4508}
4509
4510static void devm_clk_hw_unregister_cb(struct device *dev, void *res)
4511{
4512 clk_hw_unregister(*(struct clk_hw **)res);
4513}
4514
4515/**
4516 * devm_clk_register - resource managed clk_register()
4517 * @dev: device that is registering this clock
4518 * @hw: link to hardware-specific clock data
4519 *
4520 * Managed clk_register(). This function is *deprecated*, use devm_clk_hw_register() instead.
4521 *
4522 * Clocks returned from this function are automatically clk_unregister()ed on
4523 * driver detach. See clk_register() for more information.
4524 */
4525struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
4526{
4527 struct clk *clk;
4528 struct clk **clkp;
4529
4530 clkp = devres_alloc(devm_clk_unregister_cb, sizeof(*clkp), GFP_KERNEL);
4531 if (!clkp)
4532 return ERR_PTR(-ENOMEM);
4533
4534 clk = clk_register(dev, hw);
4535 if (!IS_ERR(clk)) {
4536 *clkp = clk;
4537 devres_add(dev, clkp);
4538 } else {
4539 devres_free(clkp);
4540 }
4541
4542 return clk;
4543}
4544EXPORT_SYMBOL_GPL(devm_clk_register);
4545
4546/**
4547 * devm_clk_hw_register - resource managed clk_hw_register()
4548 * @dev: device that is registering this clock
4549 * @hw: link to hardware-specific clock data
4550 *
4551 * Managed clk_hw_register(). Clocks registered by this function are
4552 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
4553 * for more information.
4554 */
4555int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
4556{
4557 struct clk_hw **hwp;
4558 int ret;
4559
4560 hwp = devres_alloc(devm_clk_hw_unregister_cb, sizeof(*hwp), GFP_KERNEL);
4561 if (!hwp)
4562 return -ENOMEM;
4563
4564 ret = clk_hw_register(dev, hw);
4565 if (!ret) {
4566 *hwp = hw;
4567 devres_add(dev, hwp);
4568 } else {
4569 devres_free(hwp);
4570 }
4571
4572 return ret;
4573}
4574EXPORT_SYMBOL_GPL(devm_clk_hw_register);
4575
4576static void devm_clk_release(struct device *dev, void *res)
4577{
4578 clk_put(*(struct clk **)res);
4579}
4580
4581/**
4582 * devm_clk_hw_get_clk - resource managed clk_hw_get_clk()
4583 * @dev: device that is registering this clock
4584 * @hw: clk_hw associated with the clk being consumed
4585 * @con_id: connection ID string on device
4586 *
4587 * Managed clk_hw_get_clk(). Clocks got with this function are
4588 * automatically clk_put() on driver detach. See clk_put()
4589 * for more information.
4590 */
4591struct clk *devm_clk_hw_get_clk(struct device *dev, struct clk_hw *hw,
4592 const char *con_id)
4593{
4594 struct clk *clk;
4595 struct clk **clkp;
4596
4597 /* This should not happen because it would mean we have drivers
4598 * passing around clk_hw pointers instead of having the caller use
4599 * proper clk_get() style APIs
4600 */
4601 WARN_ON_ONCE(dev != hw->core->dev);
4602
4603 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
4604 if (!clkp)
4605 return ERR_PTR(-ENOMEM);
4606
4607 clk = clk_hw_get_clk(hw, con_id);
4608 if (!IS_ERR(clk)) {
4609 *clkp = clk;
4610 devres_add(dev, clkp);
4611 } else {
4612 devres_free(clkp);
4613 }
4614
4615 return clk;
4616}
4617EXPORT_SYMBOL_GPL(devm_clk_hw_get_clk);
4618
4619/*
4620 * clkdev helpers
4621 */
4622
4623void __clk_put(struct clk *clk)
4624{
4625 struct module *owner;
4626
4627 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4628 return;
4629
4630 clk_prepare_lock();
4631
4632 /*
4633 * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
4634 * given user should be balanced with calls to clk_rate_exclusive_put()
4635 * and by that same consumer
4636 */
4637 if (WARN_ON(clk->exclusive_count)) {
4638 /* We voiced our concern, let's sanitize the situation */
4639 clk->core->protect_count -= (clk->exclusive_count - 1);
4640 clk_core_rate_unprotect(clk->core);
4641 clk->exclusive_count = 0;
4642 }
4643
4644 hlist_del(&clk->clks_node);
4645
4646 /* If we had any boundaries on that clock, let's drop them. */
4647 if (clk->min_rate > 0 || clk->max_rate < ULONG_MAX)
4648 clk_set_rate_range_nolock(clk, 0, ULONG_MAX);
4649
4650 owner = clk->core->owner;
4651 kref_put(&clk->core->ref, __clk_release);
4652
4653 clk_prepare_unlock();
4654
4655 module_put(owner);
4656
4657 free_clk(clk);
4658}
4659
4660/*** clk rate change notifiers ***/
4661
4662/**
4663 * clk_notifier_register - add a clk rate change notifier
4664 * @clk: struct clk * to watch
4665 * @nb: struct notifier_block * with callback info
4666 *
4667 * Request notification when clk's rate changes. This uses an SRCU
4668 * notifier because we want it to block and notifier unregistrations are
4669 * uncommon. The callbacks associated with the notifier must not
4670 * re-enter into the clk framework by calling any top-level clk APIs;
4671 * this will cause a nested prepare_lock mutex.
4672 *
4673 * In all notification cases (pre, post and abort rate change) the original
4674 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
4675 * and the new frequency is passed via struct clk_notifier_data.new_rate.
4676 *
4677 * clk_notifier_register() must be called from non-atomic context.
4678 * Returns -EINVAL if called with null arguments, -ENOMEM upon
4679 * allocation failure; otherwise, passes along the return value of
4680 * srcu_notifier_chain_register().
4681 */
4682int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
4683{
4684 struct clk_notifier *cn;
4685 int ret = -ENOMEM;
4686
4687 if (!clk || !nb)
4688 return -EINVAL;
4689
4690 clk_prepare_lock();
4691
4692 /* search the list of notifiers for this clk */
4693 list_for_each_entry(cn, &clk_notifier_list, node)
4694 if (cn->clk == clk)
4695 goto found;
4696
4697 /* if clk wasn't in the notifier list, allocate new clk_notifier */
4698 cn = kzalloc(sizeof(*cn), GFP_KERNEL);
4699 if (!cn)
4700 goto out;
4701
4702 cn->clk = clk;
4703 srcu_init_notifier_head(&cn->notifier_head);
4704
4705 list_add(&cn->node, &clk_notifier_list);
4706
4707found:
4708 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
4709
4710 clk->core->notifier_count++;
4711
4712out:
4713 clk_prepare_unlock();
4714
4715 return ret;
4716}
4717EXPORT_SYMBOL_GPL(clk_notifier_register);
4718
4719/**
4720 * clk_notifier_unregister - remove a clk rate change notifier
4721 * @clk: struct clk *
4722 * @nb: struct notifier_block * with callback info
4723 *
4724 * Request no further notification for changes to 'clk' and frees memory
4725 * allocated in clk_notifier_register.
4726 *
4727 * Returns -EINVAL if called with null arguments; otherwise, passes
4728 * along the return value of srcu_notifier_chain_unregister().
4729 */
4730int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
4731{
4732 struct clk_notifier *cn;
4733 int ret = -ENOENT;
4734
4735 if (!clk || !nb)
4736 return -EINVAL;
4737
4738 clk_prepare_lock();
4739
4740 list_for_each_entry(cn, &clk_notifier_list, node) {
4741 if (cn->clk == clk) {
4742 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
4743
4744 clk->core->notifier_count--;
4745
4746 /* XXX the notifier code should handle this better */
4747 if (!cn->notifier_head.head) {
4748 srcu_cleanup_notifier_head(&cn->notifier_head);
4749 list_del(&cn->node);
4750 kfree(cn);
4751 }
4752 break;
4753 }
4754 }
4755
4756 clk_prepare_unlock();
4757
4758 return ret;
4759}
4760EXPORT_SYMBOL_GPL(clk_notifier_unregister);
4761
4762struct clk_notifier_devres {
4763 struct clk *clk;
4764 struct notifier_block *nb;
4765};
4766
4767static void devm_clk_notifier_release(struct device *dev, void *res)
4768{
4769 struct clk_notifier_devres *devres = res;
4770
4771 clk_notifier_unregister(devres->clk, devres->nb);
4772}
4773
4774int devm_clk_notifier_register(struct device *dev, struct clk *clk,
4775 struct notifier_block *nb)
4776{
4777 struct clk_notifier_devres *devres;
4778 int ret;
4779
4780 devres = devres_alloc(devm_clk_notifier_release,
4781 sizeof(*devres), GFP_KERNEL);
4782
4783 if (!devres)
4784 return -ENOMEM;
4785
4786 ret = clk_notifier_register(clk, nb);
4787 if (!ret) {
4788 devres->clk = clk;
4789 devres->nb = nb;
4790 devres_add(dev, devres);
4791 } else {
4792 devres_free(devres);
4793 }
4794
4795 return ret;
4796}
4797EXPORT_SYMBOL_GPL(devm_clk_notifier_register);
4798
4799#ifdef CONFIG_OF
4800static void clk_core_reparent_orphans(void)
4801{
4802 clk_prepare_lock();
4803 clk_core_reparent_orphans_nolock();
4804 clk_prepare_unlock();
4805}
4806
4807/**
4808 * struct of_clk_provider - Clock provider registration structure
4809 * @link: Entry in global list of clock providers
4810 * @node: Pointer to device tree node of clock provider
4811 * @get: Get clock callback. Returns NULL or a struct clk for the
4812 * given clock specifier
4813 * @get_hw: Get clk_hw callback. Returns NULL, ERR_PTR or a
4814 * struct clk_hw for the given clock specifier
4815 * @data: context pointer to be passed into @get callback
4816 */
4817struct of_clk_provider {
4818 struct list_head link;
4819
4820 struct device_node *node;
4821 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
4822 struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
4823 void *data;
4824};
4825
4826extern struct of_device_id __clk_of_table;
4827static const struct of_device_id __clk_of_table_sentinel
4828 __used __section("__clk_of_table_end");
4829
4830static LIST_HEAD(of_clk_providers);
4831static DEFINE_MUTEX(of_clk_mutex);
4832
4833struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
4834 void *data)
4835{
4836 return data;
4837}
4838EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
4839
4840struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
4841{
4842 return data;
4843}
4844EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
4845
4846struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
4847{
4848 struct clk_onecell_data *clk_data = data;
4849 unsigned int idx = clkspec->args[0];
4850
4851 if (idx >= clk_data->clk_num) {
4852 pr_err("%s: invalid clock index %u\n", __func__, idx);
4853 return ERR_PTR(-EINVAL);
4854 }
4855
4856 return clk_data->clks[idx];
4857}
4858EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
4859
4860struct clk_hw *
4861of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
4862{
4863 struct clk_hw_onecell_data *hw_data = data;
4864 unsigned int idx = clkspec->args[0];
4865
4866 if (idx >= hw_data->num) {
4867 pr_err("%s: invalid index %u\n", __func__, idx);
4868 return ERR_PTR(-EINVAL);
4869 }
4870
4871 return hw_data->hws[idx];
4872}
4873EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
4874
4875/**
4876 * of_clk_add_provider() - Register a clock provider for a node
4877 * @np: Device node pointer associated with clock provider
4878 * @clk_src_get: callback for decoding clock
4879 * @data: context pointer for @clk_src_get callback.
4880 *
4881 * This function is *deprecated*. Use of_clk_add_hw_provider() instead.
4882 */
4883int of_clk_add_provider(struct device_node *np,
4884 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
4885 void *data),
4886 void *data)
4887{
4888 struct of_clk_provider *cp;
4889 int ret;
4890
4891 if (!np)
4892 return 0;
4893
4894 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
4895 if (!cp)
4896 return -ENOMEM;
4897
4898 cp->node = of_node_get(np);
4899 cp->data = data;
4900 cp->get = clk_src_get;
4901
4902 mutex_lock(&of_clk_mutex);
4903 list_add(&cp->link, &of_clk_providers);
4904 mutex_unlock(&of_clk_mutex);
4905 pr_debug("Added clock from %pOF\n", np);
4906
4907 clk_core_reparent_orphans();
4908
4909 ret = of_clk_set_defaults(np, true);
4910 if (ret < 0)
4911 of_clk_del_provider(np);
4912
4913 fwnode_dev_initialized(&np->fwnode, true);
4914
4915 return ret;
4916}
4917EXPORT_SYMBOL_GPL(of_clk_add_provider);
4918
4919/**
4920 * of_clk_add_hw_provider() - Register a clock provider for a node
4921 * @np: Device node pointer associated with clock provider
4922 * @get: callback for decoding clk_hw
4923 * @data: context pointer for @get callback.
4924 */
4925int of_clk_add_hw_provider(struct device_node *np,
4926 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
4927 void *data),
4928 void *data)
4929{
4930 struct of_clk_provider *cp;
4931 int ret;
4932
4933 if (!np)
4934 return 0;
4935
4936 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
4937 if (!cp)
4938 return -ENOMEM;
4939
4940 cp->node = of_node_get(np);
4941 cp->data = data;
4942 cp->get_hw = get;
4943
4944 mutex_lock(&of_clk_mutex);
4945 list_add(&cp->link, &of_clk_providers);
4946 mutex_unlock(&of_clk_mutex);
4947 pr_debug("Added clk_hw provider from %pOF\n", np);
4948
4949 clk_core_reparent_orphans();
4950
4951 ret = of_clk_set_defaults(np, true);
4952 if (ret < 0)
4953 of_clk_del_provider(np);
4954
4955 fwnode_dev_initialized(&np->fwnode, true);
4956
4957 return ret;
4958}
4959EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
4960
4961static void devm_of_clk_release_provider(struct device *dev, void *res)
4962{
4963 of_clk_del_provider(*(struct device_node **)res);
4964}
4965
4966/*
4967 * We allow a child device to use its parent device as the clock provider node
4968 * for cases like MFD sub-devices where the child device driver wants to use
4969 * devm_*() APIs but not list the device in DT as a sub-node.
4970 */
4971static struct device_node *get_clk_provider_node(struct device *dev)
4972{
4973 struct device_node *np, *parent_np;
4974
4975 np = dev->of_node;
4976 parent_np = dev->parent ? dev->parent->of_node : NULL;
4977
4978 if (!of_property_present(np, "#clock-cells"))
4979 if (of_property_present(parent_np, "#clock-cells"))
4980 np = parent_np;
4981
4982 return np;
4983}
4984
4985/**
4986 * devm_of_clk_add_hw_provider() - Managed clk provider node registration
4987 * @dev: Device acting as the clock provider (used for DT node and lifetime)
4988 * @get: callback for decoding clk_hw
4989 * @data: context pointer for @get callback
4990 *
4991 * Registers clock provider for given device's node. If the device has no DT
4992 * node or if the device node lacks of clock provider information (#clock-cells)
4993 * then the parent device's node is scanned for this information. If parent node
4994 * has the #clock-cells then it is used in registration. Provider is
4995 * automatically released at device exit.
4996 *
4997 * Return: 0 on success or an errno on failure.
4998 */
4999int devm_of_clk_add_hw_provider(struct device *dev,
5000 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
5001 void *data),
5002 void *data)
5003{
5004 struct device_node **ptr, *np;
5005 int ret;
5006
5007 ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
5008 GFP_KERNEL);
5009 if (!ptr)
5010 return -ENOMEM;
5011
5012 np = get_clk_provider_node(dev);
5013 ret = of_clk_add_hw_provider(np, get, data);
5014 if (!ret) {
5015 *ptr = np;
5016 devres_add(dev, ptr);
5017 } else {
5018 devres_free(ptr);
5019 }
5020
5021 return ret;
5022}
5023EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);
5024
5025/**
5026 * of_clk_del_provider() - Remove a previously registered clock provider
5027 * @np: Device node pointer associated with clock provider
5028 */
5029void of_clk_del_provider(struct device_node *np)
5030{
5031 struct of_clk_provider *cp;
5032
5033 if (!np)
5034 return;
5035
5036 mutex_lock(&of_clk_mutex);
5037 list_for_each_entry(cp, &of_clk_providers, link) {
5038 if (cp->node == np) {
5039 list_del(&cp->link);
5040 fwnode_dev_initialized(&np->fwnode, false);
5041 of_node_put(cp->node);
5042 kfree(cp);
5043 break;
5044 }
5045 }
5046 mutex_unlock(&of_clk_mutex);
5047}
5048EXPORT_SYMBOL_GPL(of_clk_del_provider);
5049
5050/**
5051 * of_parse_clkspec() - Parse a DT clock specifier for a given device node
5052 * @np: device node to parse clock specifier from
5053 * @index: index of phandle to parse clock out of. If index < 0, @name is used
5054 * @name: clock name to find and parse. If name is NULL, the index is used
5055 * @out_args: Result of parsing the clock specifier
5056 *
5057 * Parses a device node's "clocks" and "clock-names" properties to find the
5058 * phandle and cells for the index or name that is desired. The resulting clock
5059 * specifier is placed into @out_args, or an errno is returned when there's a
5060 * parsing error. The @index argument is ignored if @name is non-NULL.
5061 *
5062 * Example:
5063 *
5064 * phandle1: clock-controller@1 {
5065 * #clock-cells = <2>;
5066 * }
5067 *
5068 * phandle2: clock-controller@2 {
5069 * #clock-cells = <1>;
5070 * }
5071 *
5072 * clock-consumer@3 {
5073 * clocks = <&phandle1 1 2 &phandle2 3>;
5074 * clock-names = "name1", "name2";
5075 * }
5076 *
5077 * To get a device_node for `clock-controller@2' node you may call this
5078 * function a few different ways:
5079 *
5080 * of_parse_clkspec(clock-consumer@3, -1, "name2", &args);
5081 * of_parse_clkspec(clock-consumer@3, 1, NULL, &args);
5082 * of_parse_clkspec(clock-consumer@3, 1, "name2", &args);
5083 *
5084 * Return: 0 upon successfully parsing the clock specifier. Otherwise, -ENOENT
5085 * if @name is NULL or -EINVAL if @name is non-NULL and it can't be found in
5086 * the "clock-names" property of @np.
5087 */
5088static int of_parse_clkspec(const struct device_node *np, int index,
5089 const char *name, struct of_phandle_args *out_args)
5090{
5091 int ret = -ENOENT;
5092
5093 /* Walk up the tree of devices looking for a clock property that matches */
5094 while (np) {
5095 /*
5096 * For named clocks, first look up the name in the
5097 * "clock-names" property. If it cannot be found, then index
5098 * will be an error code and of_parse_phandle_with_args() will
5099 * return -EINVAL.
5100 */
5101 if (name)
5102 index = of_property_match_string(np, "clock-names", name);
5103 ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells",
5104 index, out_args);
5105 if (!ret)
5106 break;
5107 if (name && index >= 0)
5108 break;
5109
5110 /*
5111 * No matching clock found on this node. If the parent node
5112 * has a "clock-ranges" property, then we can try one of its
5113 * clocks.
5114 */
5115 np = np->parent;
5116 if (np && !of_get_property(np, "clock-ranges", NULL))
5117 break;
5118 index = 0;
5119 }
5120
5121 return ret;
5122}
5123
5124static struct clk_hw *
5125__of_clk_get_hw_from_provider(struct of_clk_provider *provider,
5126 struct of_phandle_args *clkspec)
5127{
5128 struct clk *clk;
5129
5130 if (provider->get_hw)
5131 return provider->get_hw(clkspec, provider->data);
5132
5133 clk = provider->get(clkspec, provider->data);
5134 if (IS_ERR(clk))
5135 return ERR_CAST(clk);
5136 return __clk_get_hw(clk);
5137}
5138
5139static struct clk_hw *
5140of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
5141{
5142 struct of_clk_provider *provider;
5143 struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER);
5144
5145 if (!clkspec)
5146 return ERR_PTR(-EINVAL);
5147
5148 mutex_lock(&of_clk_mutex);
5149 list_for_each_entry(provider, &of_clk_providers, link) {
5150 if (provider->node == clkspec->np) {
5151 hw = __of_clk_get_hw_from_provider(provider, clkspec);
5152 if (!IS_ERR(hw))
5153 break;
5154 }
5155 }
5156 mutex_unlock(&of_clk_mutex);
5157
5158 return hw;
5159}
5160
5161/**
5162 * of_clk_get_from_provider() - Lookup a clock from a clock provider
5163 * @clkspec: pointer to a clock specifier data structure
5164 *
5165 * This function looks up a struct clk from the registered list of clock
5166 * providers, an input is a clock specifier data structure as returned
5167 * from the of_parse_phandle_with_args() function call.
5168 */
5169struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
5170{
5171 struct clk_hw *hw = of_clk_get_hw_from_clkspec(clkspec);
5172
5173 return clk_hw_create_clk(NULL, hw, NULL, __func__);
5174}
5175EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
5176
5177struct clk_hw *of_clk_get_hw(struct device_node *np, int index,
5178 const char *con_id)
5179{
5180 int ret;
5181 struct clk_hw *hw;
5182 struct of_phandle_args clkspec;
5183
5184 ret = of_parse_clkspec(np, index, con_id, &clkspec);
5185 if (ret)
5186 return ERR_PTR(ret);
5187
5188 hw = of_clk_get_hw_from_clkspec(&clkspec);
5189 of_node_put(clkspec.np);
5190
5191 return hw;
5192}
5193
5194static struct clk *__of_clk_get(struct device_node *np,
5195 int index, const char *dev_id,
5196 const char *con_id)
5197{
5198 struct clk_hw *hw = of_clk_get_hw(np, index, con_id);
5199
5200 return clk_hw_create_clk(NULL, hw, dev_id, con_id);
5201}
5202
5203struct clk *of_clk_get(struct device_node *np, int index)
5204{
5205 return __of_clk_get(np, index, np->full_name, NULL);
5206}
5207EXPORT_SYMBOL(of_clk_get);
5208
5209/**
5210 * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
5211 * @np: pointer to clock consumer node
5212 * @name: name of consumer's clock input, or NULL for the first clock reference
5213 *
5214 * This function parses the clocks and clock-names properties,
5215 * and uses them to look up the struct clk from the registered list of clock
5216 * providers.
5217 */
5218struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
5219{
5220 if (!np)
5221 return ERR_PTR(-ENOENT);
5222
5223 return __of_clk_get(np, 0, np->full_name, name);
5224}
5225EXPORT_SYMBOL(of_clk_get_by_name);
5226
5227/**
5228 * of_clk_get_parent_count() - Count the number of clocks a device node has
5229 * @np: device node to count
5230 *
5231 * Returns: The number of clocks that are possible parents of this node
5232 */
5233unsigned int of_clk_get_parent_count(const struct device_node *np)
5234{
5235 int count;
5236
5237 count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
5238 if (count < 0)
5239 return 0;
5240
5241 return count;
5242}
5243EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
5244
5245const char *of_clk_get_parent_name(const struct device_node *np, int index)
5246{
5247 struct of_phandle_args clkspec;
5248 struct property *prop;
5249 const char *clk_name;
5250 const __be32 *vp;
5251 u32 pv;
5252 int rc;
5253 int count;
5254 struct clk *clk;
5255
5256 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
5257 &clkspec);
5258 if (rc)
5259 return NULL;
5260
5261 index = clkspec.args_count ? clkspec.args[0] : 0;
5262 count = 0;
5263
5264 /* if there is an indices property, use it to transfer the index
5265 * specified into an array offset for the clock-output-names property.
5266 */
5267 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
5268 if (index == pv) {
5269 index = count;
5270 break;
5271 }
5272 count++;
5273 }
5274 /* We went off the end of 'clock-indices' without finding it */
5275 if (prop && !vp)
5276 return NULL;
5277
5278 if (of_property_read_string_index(clkspec.np, "clock-output-names",
5279 index,
5280 &clk_name) < 0) {
5281 /*
5282 * Best effort to get the name if the clock has been
5283 * registered with the framework. If the clock isn't
5284 * registered, we return the node name as the name of
5285 * the clock as long as #clock-cells = 0.
5286 */
5287 clk = of_clk_get_from_provider(&clkspec);
5288 if (IS_ERR(clk)) {
5289 if (clkspec.args_count == 0)
5290 clk_name = clkspec.np->name;
5291 else
5292 clk_name = NULL;
5293 } else {
5294 clk_name = __clk_get_name(clk);
5295 clk_put(clk);
5296 }
5297 }
5298
5299
5300 of_node_put(clkspec.np);
5301 return clk_name;
5302}
5303EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
5304
5305/**
5306 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
5307 * number of parents
5308 * @np: Device node pointer associated with clock provider
5309 * @parents: pointer to char array that hold the parents' names
5310 * @size: size of the @parents array
5311 *
5312 * Return: number of parents for the clock node.
5313 */
5314int of_clk_parent_fill(struct device_node *np, const char **parents,
5315 unsigned int size)
5316{
5317 unsigned int i = 0;
5318
5319 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
5320 i++;
5321
5322 return i;
5323}
5324EXPORT_SYMBOL_GPL(of_clk_parent_fill);
5325
5326struct clock_provider {
5327 void (*clk_init_cb)(struct device_node *);
5328 struct device_node *np;
5329 struct list_head node;
5330};
5331
5332/*
5333 * This function looks for a parent clock. If there is one, then it
5334 * checks that the provider for this parent clock was initialized, in
5335 * this case the parent clock will be ready.
5336 */
5337static int parent_ready(struct device_node *np)
5338{
5339 int i = 0;
5340
5341 while (true) {
5342 struct clk *clk = of_clk_get(np, i);
5343
5344 /* this parent is ready we can check the next one */
5345 if (!IS_ERR(clk)) {
5346 clk_put(clk);
5347 i++;
5348 continue;
5349 }
5350
5351 /* at least one parent is not ready, we exit now */
5352 if (PTR_ERR(clk) == -EPROBE_DEFER)
5353 return 0;
5354
5355 /*
5356 * Here we make assumption that the device tree is
5357 * written correctly. So an error means that there is
5358 * no more parent. As we didn't exit yet, then the
5359 * previous parent are ready. If there is no clock
5360 * parent, no need to wait for them, then we can
5361 * consider their absence as being ready
5362 */
5363 return 1;
5364 }
5365}
5366
5367/**
5368 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
5369 * @np: Device node pointer associated with clock provider
5370 * @index: clock index
5371 * @flags: pointer to top-level framework flags
5372 *
5373 * Detects if the clock-critical property exists and, if so, sets the
5374 * corresponding CLK_IS_CRITICAL flag.
5375 *
5376 * Do not use this function. It exists only for legacy Device Tree
5377 * bindings, such as the one-clock-per-node style that are outdated.
5378 * Those bindings typically put all clock data into .dts and the Linux
5379 * driver has no clock data, thus making it impossible to set this flag
5380 * correctly from the driver. Only those drivers may call
5381 * of_clk_detect_critical from their setup functions.
5382 *
5383 * Return: error code or zero on success
5384 */
5385int of_clk_detect_critical(struct device_node *np, int index,
5386 unsigned long *flags)
5387{
5388 struct property *prop;
5389 const __be32 *cur;
5390 uint32_t idx;
5391
5392 if (!np || !flags)
5393 return -EINVAL;
5394
5395 of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
5396 if (index == idx)
5397 *flags |= CLK_IS_CRITICAL;
5398
5399 return 0;
5400}
5401
5402/**
5403 * of_clk_init() - Scan and init clock providers from the DT
5404 * @matches: array of compatible values and init functions for providers.
5405 *
5406 * This function scans the device tree for matching clock providers
5407 * and calls their initialization functions. It also does it by trying
5408 * to follow the dependencies.
5409 */
5410void __init of_clk_init(const struct of_device_id *matches)
5411{
5412 const struct of_device_id *match;
5413 struct device_node *np;
5414 struct clock_provider *clk_provider, *next;
5415 bool is_init_done;
5416 bool force = false;
5417 LIST_HEAD(clk_provider_list);
5418
5419 if (!matches)
5420 matches = &__clk_of_table;
5421
5422 /* First prepare the list of the clocks providers */
5423 for_each_matching_node_and_match(np, matches, &match) {
5424 struct clock_provider *parent;
5425
5426 if (!of_device_is_available(np))
5427 continue;
5428
5429 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
5430 if (!parent) {
5431 list_for_each_entry_safe(clk_provider, next,
5432 &clk_provider_list, node) {
5433 list_del(&clk_provider->node);
5434 of_node_put(clk_provider->np);
5435 kfree(clk_provider);
5436 }
5437 of_node_put(np);
5438 return;
5439 }
5440
5441 parent->clk_init_cb = match->data;
5442 parent->np = of_node_get(np);
5443 list_add_tail(&parent->node, &clk_provider_list);
5444 }
5445
5446 while (!list_empty(&clk_provider_list)) {
5447 is_init_done = false;
5448 list_for_each_entry_safe(clk_provider, next,
5449 &clk_provider_list, node) {
5450 if (force || parent_ready(clk_provider->np)) {
5451
5452 /* Don't populate platform devices */
5453 of_node_set_flag(clk_provider->np,
5454 OF_POPULATED);
5455
5456 clk_provider->clk_init_cb(clk_provider->np);
5457 of_clk_set_defaults(clk_provider->np, true);
5458
5459 list_del(&clk_provider->node);
5460 of_node_put(clk_provider->np);
5461 kfree(clk_provider);
5462 is_init_done = true;
5463 }
5464 }
5465
5466 /*
5467 * We didn't manage to initialize any of the
5468 * remaining providers during the last loop, so now we
5469 * initialize all the remaining ones unconditionally
5470 * in case the clock parent was not mandatory
5471 */
5472 if (!is_init_done)
5473 force = true;
5474 }
5475}
5476#endif