2 * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
3 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
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.
9 * Standard functionality for the common clock API. See Documentation/clk.txt
12 #include <linux/clk.h>
13 #include <linux/clk-provider.h>
14 #include <linux/clk/clk-conf.h>
15 #include <linux/module.h>
16 #include <linux/mutex.h>
17 #include <linux/spinlock.h>
18 #include <linux/err.h>
19 #include <linux/list.h>
20 #include <linux/slab.h>
22 #include <linux/device.h>
23 #include <linux/init.h>
24 #include <linux/sched.h>
25 #include <linux/clkdev.h>
29 static DEFINE_SPINLOCK(enable_lock
);
30 static DEFINE_MUTEX(prepare_lock
);
32 static struct task_struct
*prepare_owner
;
33 static struct task_struct
*enable_owner
;
35 static int prepare_refcnt
;
36 static int enable_refcnt
;
38 static HLIST_HEAD(clk_root_list
);
39 static HLIST_HEAD(clk_orphan_list
);
40 static LIST_HEAD(clk_notifier_list
);
42 /*** private data structures ***/
46 const struct clk_ops
*ops
;
49 struct clk_core
*parent
;
50 const char **parent_names
;
51 struct clk_core
**parents
;
55 unsigned long req_rate
;
56 unsigned long new_rate
;
57 struct clk_core
*new_parent
;
58 struct clk_core
*new_child
;
61 unsigned int enable_count
;
62 unsigned int prepare_count
;
63 unsigned long min_rate
;
64 unsigned long max_rate
;
65 unsigned long accuracy
;
67 struct hlist_head children
;
68 struct hlist_node child_node
;
69 struct hlist_head clks
;
70 unsigned int notifier_count
;
71 #ifdef CONFIG_DEBUG_FS
72 struct dentry
*dentry
;
73 struct hlist_node debug_node
;
78 #define CREATE_TRACE_POINTS
79 #include <trace/events/clk.h>
82 struct clk_core
*core
;
85 unsigned long min_rate
;
86 unsigned long max_rate
;
87 struct hlist_node clks_node
;
91 static void clk_prepare_lock(void)
93 if (!mutex_trylock(&prepare_lock
)) {
94 if (prepare_owner
== current
) {
98 mutex_lock(&prepare_lock
);
100 WARN_ON_ONCE(prepare_owner
!= NULL
);
101 WARN_ON_ONCE(prepare_refcnt
!= 0);
102 prepare_owner
= current
;
106 static void clk_prepare_unlock(void)
108 WARN_ON_ONCE(prepare_owner
!= current
);
109 WARN_ON_ONCE(prepare_refcnt
== 0);
111 if (--prepare_refcnt
)
113 prepare_owner
= NULL
;
114 mutex_unlock(&prepare_lock
);
117 static unsigned long clk_enable_lock(void)
118 __acquires(enable_lock
)
122 if (!spin_trylock_irqsave(&enable_lock
, flags
)) {
123 if (enable_owner
== current
) {
125 __acquire(enable_lock
);
128 spin_lock_irqsave(&enable_lock
, flags
);
130 WARN_ON_ONCE(enable_owner
!= NULL
);
131 WARN_ON_ONCE(enable_refcnt
!= 0);
132 enable_owner
= current
;
137 static void clk_enable_unlock(unsigned long flags
)
138 __releases(enable_lock
)
140 WARN_ON_ONCE(enable_owner
!= current
);
141 WARN_ON_ONCE(enable_refcnt
== 0);
143 if (--enable_refcnt
) {
144 __release(enable_lock
);
148 spin_unlock_irqrestore(&enable_lock
, flags
);
151 static bool clk_core_is_prepared(struct clk_core
*core
)
154 * .is_prepared is optional for clocks that can prepare
155 * fall back to software usage counter if it is missing
157 if (!core
->ops
->is_prepared
)
158 return core
->prepare_count
;
160 return core
->ops
->is_prepared(core
->hw
);
163 static bool clk_core_is_enabled(struct clk_core
*core
)
166 * .is_enabled is only mandatory for clocks that gate
167 * fall back to software usage counter if .is_enabled is missing
169 if (!core
->ops
->is_enabled
)
170 return core
->enable_count
;
172 return core
->ops
->is_enabled(core
->hw
);
175 /*** helper functions ***/
177 const char *__clk_get_name(const struct clk
*clk
)
179 return !clk
? NULL
: clk
->core
->name
;
181 EXPORT_SYMBOL_GPL(__clk_get_name
);
183 const char *clk_hw_get_name(const struct clk_hw
*hw
)
185 return hw
->core
->name
;
187 EXPORT_SYMBOL_GPL(clk_hw_get_name
);
189 struct clk_hw
*__clk_get_hw(struct clk
*clk
)
191 return !clk
? NULL
: clk
->core
->hw
;
193 EXPORT_SYMBOL_GPL(__clk_get_hw
);
195 unsigned int clk_hw_get_num_parents(const struct clk_hw
*hw
)
197 return hw
->core
->num_parents
;
199 EXPORT_SYMBOL_GPL(clk_hw_get_num_parents
);
201 struct clk_hw
*clk_hw_get_parent(const struct clk_hw
*hw
)
203 return hw
->core
->parent
? hw
->core
->parent
->hw
: NULL
;
205 EXPORT_SYMBOL_GPL(clk_hw_get_parent
);
207 static struct clk_core
*__clk_lookup_subtree(const char *name
,
208 struct clk_core
*core
)
210 struct clk_core
*child
;
211 struct clk_core
*ret
;
213 if (!strcmp(core
->name
, name
))
216 hlist_for_each_entry(child
, &core
->children
, child_node
) {
217 ret
= __clk_lookup_subtree(name
, child
);
225 static struct clk_core
*clk_core_lookup(const char *name
)
227 struct clk_core
*root_clk
;
228 struct clk_core
*ret
;
233 /* search the 'proper' clk tree first */
234 hlist_for_each_entry(root_clk
, &clk_root_list
, child_node
) {
235 ret
= __clk_lookup_subtree(name
, root_clk
);
240 /* if not found, then search the orphan tree */
241 hlist_for_each_entry(root_clk
, &clk_orphan_list
, child_node
) {
242 ret
= __clk_lookup_subtree(name
, root_clk
);
250 static struct clk_core
*clk_core_get_parent_by_index(struct clk_core
*core
,
253 if (!core
|| index
>= core
->num_parents
)
256 if (!core
->parents
[index
])
257 core
->parents
[index
] =
258 clk_core_lookup(core
->parent_names
[index
]);
260 return core
->parents
[index
];
264 clk_hw_get_parent_by_index(const struct clk_hw
*hw
, unsigned int index
)
266 struct clk_core
*parent
;
268 parent
= clk_core_get_parent_by_index(hw
->core
, index
);
270 return !parent
? NULL
: parent
->hw
;
272 EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index
);
274 unsigned int __clk_get_enable_count(struct clk
*clk
)
276 return !clk
? 0 : clk
->core
->enable_count
;
279 static unsigned long clk_core_get_rate_nolock(struct clk_core
*core
)
290 if (!core
->num_parents
)
300 unsigned long clk_hw_get_rate(const struct clk_hw
*hw
)
302 return clk_core_get_rate_nolock(hw
->core
);
304 EXPORT_SYMBOL_GPL(clk_hw_get_rate
);
306 static unsigned long __clk_get_accuracy(struct clk_core
*core
)
311 return core
->accuracy
;
314 unsigned long __clk_get_flags(struct clk
*clk
)
316 return !clk
? 0 : clk
->core
->flags
;
318 EXPORT_SYMBOL_GPL(__clk_get_flags
);
320 unsigned long clk_hw_get_flags(const struct clk_hw
*hw
)
322 return hw
->core
->flags
;
324 EXPORT_SYMBOL_GPL(clk_hw_get_flags
);
326 bool clk_hw_is_prepared(const struct clk_hw
*hw
)
328 return clk_core_is_prepared(hw
->core
);
331 bool clk_hw_is_enabled(const struct clk_hw
*hw
)
333 return clk_core_is_enabled(hw
->core
);
336 bool __clk_is_enabled(struct clk
*clk
)
341 return clk_core_is_enabled(clk
->core
);
343 EXPORT_SYMBOL_GPL(__clk_is_enabled
);
345 static bool mux_is_better_rate(unsigned long rate
, unsigned long now
,
346 unsigned long best
, unsigned long flags
)
348 if (flags
& CLK_MUX_ROUND_CLOSEST
)
349 return abs(now
- rate
) < abs(best
- rate
);
351 return now
<= rate
&& now
> best
;
355 clk_mux_determine_rate_flags(struct clk_hw
*hw
, struct clk_rate_request
*req
,
358 struct clk_core
*core
= hw
->core
, *parent
, *best_parent
= NULL
;
359 int i
, num_parents
, ret
;
360 unsigned long best
= 0;
361 struct clk_rate_request parent_req
= *req
;
363 /* if NO_REPARENT flag set, pass through to current parent */
364 if (core
->flags
& CLK_SET_RATE_NO_REPARENT
) {
365 parent
= core
->parent
;
366 if (core
->flags
& CLK_SET_RATE_PARENT
) {
367 ret
= __clk_determine_rate(parent
? parent
->hw
: NULL
,
372 best
= parent_req
.rate
;
374 best
= clk_core_get_rate_nolock(parent
);
376 best
= clk_core_get_rate_nolock(core
);
382 /* find the parent that can provide the fastest rate <= rate */
383 num_parents
= core
->num_parents
;
384 for (i
= 0; i
< num_parents
; i
++) {
385 parent
= clk_core_get_parent_by_index(core
, i
);
389 if (core
->flags
& CLK_SET_RATE_PARENT
) {
391 ret
= __clk_determine_rate(parent
->hw
, &parent_req
);
395 parent_req
.rate
= clk_core_get_rate_nolock(parent
);
398 if (mux_is_better_rate(req
->rate
, parent_req
.rate
,
400 best_parent
= parent
;
401 best
= parent_req
.rate
;
410 req
->best_parent_hw
= best_parent
->hw
;
411 req
->best_parent_rate
= best
;
417 struct clk
*__clk_lookup(const char *name
)
419 struct clk_core
*core
= clk_core_lookup(name
);
421 return !core
? NULL
: core
->hw
->clk
;
424 static void clk_core_get_boundaries(struct clk_core
*core
,
425 unsigned long *min_rate
,
426 unsigned long *max_rate
)
428 struct clk
*clk_user
;
430 *min_rate
= core
->min_rate
;
431 *max_rate
= core
->max_rate
;
433 hlist_for_each_entry(clk_user
, &core
->clks
, clks_node
)
434 *min_rate
= max(*min_rate
, clk_user
->min_rate
);
436 hlist_for_each_entry(clk_user
, &core
->clks
, clks_node
)
437 *max_rate
= min(*max_rate
, clk_user
->max_rate
);
440 void clk_hw_set_rate_range(struct clk_hw
*hw
, unsigned long min_rate
,
441 unsigned long max_rate
)
443 hw
->core
->min_rate
= min_rate
;
444 hw
->core
->max_rate
= max_rate
;
446 EXPORT_SYMBOL_GPL(clk_hw_set_rate_range
);
449 * Helper for finding best parent to provide a given frequency. This can be used
450 * directly as a determine_rate callback (e.g. for a mux), or from a more
451 * complex clock that may combine a mux with other operations.
453 int __clk_mux_determine_rate(struct clk_hw
*hw
,
454 struct clk_rate_request
*req
)
456 return clk_mux_determine_rate_flags(hw
, req
, 0);
458 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate
);
460 int __clk_mux_determine_rate_closest(struct clk_hw
*hw
,
461 struct clk_rate_request
*req
)
463 return clk_mux_determine_rate_flags(hw
, req
, CLK_MUX_ROUND_CLOSEST
);
465 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest
);
469 static void clk_core_unprepare(struct clk_core
*core
)
471 lockdep_assert_held(&prepare_lock
);
476 if (WARN_ON(core
->prepare_count
== 0))
479 if (WARN_ON(core
->prepare_count
== 1 && core
->flags
& CLK_IS_CRITICAL
))
482 if (--core
->prepare_count
> 0)
485 WARN_ON(core
->enable_count
> 0);
487 trace_clk_unprepare(core
);
489 if (core
->ops
->unprepare
)
490 core
->ops
->unprepare(core
->hw
);
492 trace_clk_unprepare_complete(core
);
493 clk_core_unprepare(core
->parent
);
496 static void clk_core_unprepare_lock(struct clk_core
*core
)
499 clk_core_unprepare(core
);
500 clk_prepare_unlock();
504 * clk_unprepare - undo preparation of a clock source
505 * @clk: the clk being unprepared
507 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
508 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
509 * if the operation may sleep. One example is a clk which is accessed over
510 * I2c. In the complex case a clk gate operation may require a fast and a slow
511 * part. It is this reason that clk_unprepare and clk_disable are not mutually
512 * exclusive. In fact clk_disable must be called before clk_unprepare.
514 void clk_unprepare(struct clk
*clk
)
516 if (IS_ERR_OR_NULL(clk
))
519 clk_core_unprepare_lock(clk
->core
);
521 EXPORT_SYMBOL_GPL(clk_unprepare
);
523 static int clk_core_prepare(struct clk_core
*core
)
527 lockdep_assert_held(&prepare_lock
);
532 if (core
->prepare_count
== 0) {
533 ret
= clk_core_prepare(core
->parent
);
537 trace_clk_prepare(core
);
539 if (core
->ops
->prepare
)
540 ret
= core
->ops
->prepare(core
->hw
);
542 trace_clk_prepare_complete(core
);
545 clk_core_unprepare(core
->parent
);
550 core
->prepare_count
++;
555 static int clk_core_prepare_lock(struct clk_core
*core
)
560 ret
= clk_core_prepare(core
);
561 clk_prepare_unlock();
567 * clk_prepare - prepare a clock source
568 * @clk: the clk being prepared
570 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
571 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
572 * operation may sleep. One example is a clk which is accessed over I2c. In
573 * the complex case a clk ungate operation may require a fast and a slow part.
574 * It is this reason that clk_prepare and clk_enable are not mutually
575 * exclusive. In fact clk_prepare must be called before clk_enable.
576 * Returns 0 on success, -EERROR otherwise.
578 int clk_prepare(struct clk
*clk
)
583 return clk_core_prepare_lock(clk
->core
);
585 EXPORT_SYMBOL_GPL(clk_prepare
);
587 static void clk_core_disable(struct clk_core
*core
)
589 lockdep_assert_held(&enable_lock
);
594 if (WARN_ON(core
->enable_count
== 0))
597 if (WARN_ON(core
->enable_count
== 1 && core
->flags
& CLK_IS_CRITICAL
))
600 if (--core
->enable_count
> 0)
603 trace_clk_disable_rcuidle(core
);
605 if (core
->ops
->disable
)
606 core
->ops
->disable(core
->hw
);
608 trace_clk_disable_complete_rcuidle(core
);
610 clk_core_disable(core
->parent
);
613 static void clk_core_disable_lock(struct clk_core
*core
)
617 flags
= clk_enable_lock();
618 clk_core_disable(core
);
619 clk_enable_unlock(flags
);
623 * clk_disable - gate a clock
624 * @clk: the clk being gated
626 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
627 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
628 * clk if the operation is fast and will never sleep. One example is a
629 * SoC-internal clk which is controlled via simple register writes. In the
630 * complex case a clk gate operation may require a fast and a slow part. It is
631 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
632 * In fact clk_disable must be called before clk_unprepare.
634 void clk_disable(struct clk
*clk
)
636 if (IS_ERR_OR_NULL(clk
))
639 clk_core_disable_lock(clk
->core
);
641 EXPORT_SYMBOL_GPL(clk_disable
);
643 static int clk_core_enable(struct clk_core
*core
)
647 lockdep_assert_held(&enable_lock
);
652 if (WARN_ON(core
->prepare_count
== 0))
655 if (core
->enable_count
== 0) {
656 ret
= clk_core_enable(core
->parent
);
661 trace_clk_enable_rcuidle(core
);
663 if (core
->ops
->enable
)
664 ret
= core
->ops
->enable(core
->hw
);
666 trace_clk_enable_complete_rcuidle(core
);
669 clk_core_disable(core
->parent
);
674 core
->enable_count
++;
678 static int clk_core_enable_lock(struct clk_core
*core
)
683 flags
= clk_enable_lock();
684 ret
= clk_core_enable(core
);
685 clk_enable_unlock(flags
);
691 * clk_enable - ungate a clock
692 * @clk: the clk being ungated
694 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
695 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
696 * if the operation will never sleep. One example is a SoC-internal clk which
697 * is controlled via simple register writes. In the complex case a clk ungate
698 * operation may require a fast and a slow part. It is this reason that
699 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
700 * must be called before clk_enable. Returns 0 on success, -EERROR
703 int clk_enable(struct clk
*clk
)
708 return clk_core_enable_lock(clk
->core
);
710 EXPORT_SYMBOL_GPL(clk_enable
);
712 static int clk_core_prepare_enable(struct clk_core
*core
)
716 ret
= clk_core_prepare_lock(core
);
720 ret
= clk_core_enable_lock(core
);
722 clk_core_unprepare_lock(core
);
727 static void clk_core_disable_unprepare(struct clk_core
*core
)
729 clk_core_disable_lock(core
);
730 clk_core_unprepare_lock(core
);
733 static void clk_unprepare_unused_subtree(struct clk_core
*core
)
735 struct clk_core
*child
;
737 lockdep_assert_held(&prepare_lock
);
739 hlist_for_each_entry(child
, &core
->children
, child_node
)
740 clk_unprepare_unused_subtree(child
);
742 if (core
->prepare_count
)
745 if (core
->flags
& CLK_IGNORE_UNUSED
)
748 if (clk_core_is_prepared(core
)) {
749 trace_clk_unprepare(core
);
750 if (core
->ops
->unprepare_unused
)
751 core
->ops
->unprepare_unused(core
->hw
);
752 else if (core
->ops
->unprepare
)
753 core
->ops
->unprepare(core
->hw
);
754 trace_clk_unprepare_complete(core
);
758 static void clk_disable_unused_subtree(struct clk_core
*core
)
760 struct clk_core
*child
;
763 lockdep_assert_held(&prepare_lock
);
765 hlist_for_each_entry(child
, &core
->children
, child_node
)
766 clk_disable_unused_subtree(child
);
768 if (core
->flags
& CLK_OPS_PARENT_ENABLE
)
769 clk_core_prepare_enable(core
->parent
);
771 flags
= clk_enable_lock();
773 if (core
->enable_count
)
776 if (core
->flags
& CLK_IGNORE_UNUSED
)
780 * some gate clocks have special needs during the disable-unused
781 * sequence. call .disable_unused if available, otherwise fall
784 if (clk_core_is_enabled(core
)) {
785 trace_clk_disable(core
);
786 if (core
->ops
->disable_unused
)
787 core
->ops
->disable_unused(core
->hw
);
788 else if (core
->ops
->disable
)
789 core
->ops
->disable(core
->hw
);
790 trace_clk_disable_complete(core
);
794 clk_enable_unlock(flags
);
795 if (core
->flags
& CLK_OPS_PARENT_ENABLE
)
796 clk_core_disable_unprepare(core
->parent
);
799 static bool clk_ignore_unused
;
800 static int __init
clk_ignore_unused_setup(char *__unused
)
802 clk_ignore_unused
= true;
805 __setup("clk_ignore_unused", clk_ignore_unused_setup
);
807 static int clk_disable_unused(void)
809 struct clk_core
*core
;
811 if (clk_ignore_unused
) {
812 pr_warn("clk: Not disabling unused clocks\n");
818 hlist_for_each_entry(core
, &clk_root_list
, child_node
)
819 clk_disable_unused_subtree(core
);
821 hlist_for_each_entry(core
, &clk_orphan_list
, child_node
)
822 clk_disable_unused_subtree(core
);
824 hlist_for_each_entry(core
, &clk_root_list
, child_node
)
825 clk_unprepare_unused_subtree(core
);
827 hlist_for_each_entry(core
, &clk_orphan_list
, child_node
)
828 clk_unprepare_unused_subtree(core
);
830 clk_prepare_unlock();
834 late_initcall_sync(clk_disable_unused
);
836 static int clk_core_round_rate_nolock(struct clk_core
*core
,
837 struct clk_rate_request
*req
)
839 struct clk_core
*parent
;
842 lockdep_assert_held(&prepare_lock
);
847 parent
= core
->parent
;
849 req
->best_parent_hw
= parent
->hw
;
850 req
->best_parent_rate
= parent
->rate
;
852 req
->best_parent_hw
= NULL
;
853 req
->best_parent_rate
= 0;
856 if (core
->ops
->determine_rate
) {
857 return core
->ops
->determine_rate(core
->hw
, req
);
858 } else if (core
->ops
->round_rate
) {
859 rate
= core
->ops
->round_rate(core
->hw
, req
->rate
,
860 &req
->best_parent_rate
);
865 } else if (core
->flags
& CLK_SET_RATE_PARENT
) {
866 return clk_core_round_rate_nolock(parent
, req
);
868 req
->rate
= core
->rate
;
875 * __clk_determine_rate - get the closest rate actually supported by a clock
876 * @hw: determine the rate of this clock
877 * @req: target rate request
879 * Useful for clk_ops such as .set_rate and .determine_rate.
881 int __clk_determine_rate(struct clk_hw
*hw
, struct clk_rate_request
*req
)
888 return clk_core_round_rate_nolock(hw
->core
, req
);
890 EXPORT_SYMBOL_GPL(__clk_determine_rate
);
892 unsigned long clk_hw_round_rate(struct clk_hw
*hw
, unsigned long rate
)
895 struct clk_rate_request req
;
897 clk_core_get_boundaries(hw
->core
, &req
.min_rate
, &req
.max_rate
);
900 ret
= clk_core_round_rate_nolock(hw
->core
, &req
);
906 EXPORT_SYMBOL_GPL(clk_hw_round_rate
);
909 * clk_round_rate - round the given rate for a clk
910 * @clk: the clk for which we are rounding a rate
911 * @rate: the rate which is to be rounded
913 * Takes in a rate as input and rounds it to a rate that the clk can actually
914 * use which is then returned. If clk doesn't support round_rate operation
915 * then the parent rate is returned.
917 long clk_round_rate(struct clk
*clk
, unsigned long rate
)
919 struct clk_rate_request req
;
927 clk_core_get_boundaries(clk
->core
, &req
.min_rate
, &req
.max_rate
);
930 ret
= clk_core_round_rate_nolock(clk
->core
, &req
);
931 clk_prepare_unlock();
938 EXPORT_SYMBOL_GPL(clk_round_rate
);
941 * __clk_notify - call clk notifier chain
942 * @core: clk that is changing rate
943 * @msg: clk notifier type (see include/linux/clk.h)
944 * @old_rate: old clk rate
945 * @new_rate: new clk rate
947 * Triggers a notifier call chain on the clk rate-change notification
948 * for 'clk'. Passes a pointer to the struct clk and the previous
949 * and current rates to the notifier callback. Intended to be called by
950 * internal clock code only. Returns NOTIFY_DONE from the last driver
951 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
952 * a driver returns that.
954 static int __clk_notify(struct clk_core
*core
, unsigned long msg
,
955 unsigned long old_rate
, unsigned long new_rate
)
957 struct clk_notifier
*cn
;
958 struct clk_notifier_data cnd
;
959 int ret
= NOTIFY_DONE
;
961 cnd
.old_rate
= old_rate
;
962 cnd
.new_rate
= new_rate
;
964 list_for_each_entry(cn
, &clk_notifier_list
, node
) {
965 if (cn
->clk
->core
== core
) {
967 ret
= srcu_notifier_call_chain(&cn
->notifier_head
, msg
,
969 if (ret
& NOTIFY_STOP_MASK
)
978 * __clk_recalc_accuracies
979 * @core: first clk in the subtree
981 * Walks the subtree of clks starting with clk and recalculates accuracies as
982 * it goes. Note that if a clk does not implement the .recalc_accuracy
983 * callback then it is assumed that the clock will take on the accuracy of its
986 static void __clk_recalc_accuracies(struct clk_core
*core
)
988 unsigned long parent_accuracy
= 0;
989 struct clk_core
*child
;
991 lockdep_assert_held(&prepare_lock
);
994 parent_accuracy
= core
->parent
->accuracy
;
996 if (core
->ops
->recalc_accuracy
)
997 core
->accuracy
= core
->ops
->recalc_accuracy(core
->hw
,
1000 core
->accuracy
= parent_accuracy
;
1002 hlist_for_each_entry(child
, &core
->children
, child_node
)
1003 __clk_recalc_accuracies(child
);
1006 static long clk_core_get_accuracy(struct clk_core
*core
)
1008 unsigned long accuracy
;
1011 if (core
&& (core
->flags
& CLK_GET_ACCURACY_NOCACHE
))
1012 __clk_recalc_accuracies(core
);
1014 accuracy
= __clk_get_accuracy(core
);
1015 clk_prepare_unlock();
1021 * clk_get_accuracy - return the accuracy of clk
1022 * @clk: the clk whose accuracy is being returned
1024 * Simply returns the cached accuracy of the clk, unless
1025 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1027 * If clk is NULL then returns 0.
1029 long clk_get_accuracy(struct clk
*clk
)
1034 return clk_core_get_accuracy(clk
->core
);
1036 EXPORT_SYMBOL_GPL(clk_get_accuracy
);
1038 static unsigned long clk_recalc(struct clk_core
*core
,
1039 unsigned long parent_rate
)
1041 if (core
->ops
->recalc_rate
)
1042 return core
->ops
->recalc_rate(core
->hw
, parent_rate
);
1047 * __clk_recalc_rates
1048 * @core: first clk in the subtree
1049 * @msg: notification type (see include/linux/clk.h)
1051 * Walks the subtree of clks starting with clk and recalculates rates as it
1052 * goes. Note that if a clk does not implement the .recalc_rate callback then
1053 * it is assumed that the clock will take on the rate of its parent.
1055 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1058 static void __clk_recalc_rates(struct clk_core
*core
, unsigned long msg
)
1060 unsigned long old_rate
;
1061 unsigned long parent_rate
= 0;
1062 struct clk_core
*child
;
1064 lockdep_assert_held(&prepare_lock
);
1066 old_rate
= core
->rate
;
1069 parent_rate
= core
->parent
->rate
;
1071 core
->rate
= clk_recalc(core
, parent_rate
);
1074 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1075 * & ABORT_RATE_CHANGE notifiers
1077 if (core
->notifier_count
&& msg
)
1078 __clk_notify(core
, msg
, old_rate
, core
->rate
);
1080 hlist_for_each_entry(child
, &core
->children
, child_node
)
1081 __clk_recalc_rates(child
, msg
);
1084 static unsigned long clk_core_get_rate(struct clk_core
*core
)
1090 if (core
&& (core
->flags
& CLK_GET_RATE_NOCACHE
))
1091 __clk_recalc_rates(core
, 0);
1093 rate
= clk_core_get_rate_nolock(core
);
1094 clk_prepare_unlock();
1100 * clk_get_rate - return the rate of clk
1101 * @clk: the clk whose rate is being returned
1103 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1104 * is set, which means a recalc_rate will be issued.
1105 * If clk is NULL then returns 0.
1107 unsigned long clk_get_rate(struct clk
*clk
)
1112 return clk_core_get_rate(clk
->core
);
1114 EXPORT_SYMBOL_GPL(clk_get_rate
);
1116 static int clk_fetch_parent_index(struct clk_core
*core
,
1117 struct clk_core
*parent
)
1124 for (i
= 0; i
< core
->num_parents
; i
++)
1125 if (clk_core_get_parent_by_index(core
, i
) == parent
)
1132 * Update the orphan status of @core and all its children.
1134 static void clk_core_update_orphan_status(struct clk_core
*core
, bool is_orphan
)
1136 struct clk_core
*child
;
1138 core
->orphan
= is_orphan
;
1140 hlist_for_each_entry(child
, &core
->children
, child_node
)
1141 clk_core_update_orphan_status(child
, is_orphan
);
1144 static void clk_reparent(struct clk_core
*core
, struct clk_core
*new_parent
)
1146 bool was_orphan
= core
->orphan
;
1148 hlist_del(&core
->child_node
);
1151 bool becomes_orphan
= new_parent
->orphan
;
1153 /* avoid duplicate POST_RATE_CHANGE notifications */
1154 if (new_parent
->new_child
== core
)
1155 new_parent
->new_child
= NULL
;
1157 hlist_add_head(&core
->child_node
, &new_parent
->children
);
1159 if (was_orphan
!= becomes_orphan
)
1160 clk_core_update_orphan_status(core
, becomes_orphan
);
1162 hlist_add_head(&core
->child_node
, &clk_orphan_list
);
1164 clk_core_update_orphan_status(core
, true);
1167 core
->parent
= new_parent
;
1170 static struct clk_core
*__clk_set_parent_before(struct clk_core
*core
,
1171 struct clk_core
*parent
)
1173 unsigned long flags
;
1174 struct clk_core
*old_parent
= core
->parent
;
1177 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
1179 * 2. Migrate prepare state between parents and prevent race with
1182 * If the clock is not prepared, then a race with
1183 * clk_enable/disable() is impossible since we already have the
1184 * prepare lock (future calls to clk_enable() need to be preceded by
1187 * If the clock is prepared, migrate the prepared state to the new
1188 * parent and also protect against a race with clk_enable() by
1189 * forcing the clock and the new parent on. This ensures that all
1190 * future calls to clk_enable() are practically NOPs with respect to
1191 * hardware and software states.
1193 * See also: Comment for clk_set_parent() below.
1196 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
1197 if (core
->flags
& CLK_OPS_PARENT_ENABLE
) {
1198 clk_core_prepare_enable(old_parent
);
1199 clk_core_prepare_enable(parent
);
1202 /* migrate prepare count if > 0 */
1203 if (core
->prepare_count
) {
1204 clk_core_prepare_enable(parent
);
1205 clk_core_enable_lock(core
);
1208 /* update the clk tree topology */
1209 flags
= clk_enable_lock();
1210 clk_reparent(core
, parent
);
1211 clk_enable_unlock(flags
);
1216 static void __clk_set_parent_after(struct clk_core
*core
,
1217 struct clk_core
*parent
,
1218 struct clk_core
*old_parent
)
1221 * Finish the migration of prepare state and undo the changes done
1222 * for preventing a race with clk_enable().
1224 if (core
->prepare_count
) {
1225 clk_core_disable_lock(core
);
1226 clk_core_disable_unprepare(old_parent
);
1229 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
1230 if (core
->flags
& CLK_OPS_PARENT_ENABLE
) {
1231 clk_core_disable_unprepare(parent
);
1232 clk_core_disable_unprepare(old_parent
);
1236 static int __clk_set_parent(struct clk_core
*core
, struct clk_core
*parent
,
1239 unsigned long flags
;
1241 struct clk_core
*old_parent
;
1243 old_parent
= __clk_set_parent_before(core
, parent
);
1245 trace_clk_set_parent(core
, parent
);
1247 /* change clock input source */
1248 if (parent
&& core
->ops
->set_parent
)
1249 ret
= core
->ops
->set_parent(core
->hw
, p_index
);
1251 trace_clk_set_parent_complete(core
, parent
);
1254 flags
= clk_enable_lock();
1255 clk_reparent(core
, old_parent
);
1256 clk_enable_unlock(flags
);
1257 __clk_set_parent_after(core
, old_parent
, parent
);
1262 __clk_set_parent_after(core
, parent
, old_parent
);
1268 * __clk_speculate_rates
1269 * @core: first clk in the subtree
1270 * @parent_rate: the "future" rate of clk's parent
1272 * Walks the subtree of clks starting with clk, speculating rates as it
1273 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1275 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1276 * pre-rate change notifications and returns early if no clks in the
1277 * subtree have subscribed to the notifications. Note that if a clk does not
1278 * implement the .recalc_rate callback then it is assumed that the clock will
1279 * take on the rate of its parent.
1281 static int __clk_speculate_rates(struct clk_core
*core
,
1282 unsigned long parent_rate
)
1284 struct clk_core
*child
;
1285 unsigned long new_rate
;
1286 int ret
= NOTIFY_DONE
;
1288 lockdep_assert_held(&prepare_lock
);
1290 new_rate
= clk_recalc(core
, parent_rate
);
1292 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1293 if (core
->notifier_count
)
1294 ret
= __clk_notify(core
, PRE_RATE_CHANGE
, core
->rate
, new_rate
);
1296 if (ret
& NOTIFY_STOP_MASK
) {
1297 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1298 __func__
, core
->name
, ret
);
1302 hlist_for_each_entry(child
, &core
->children
, child_node
) {
1303 ret
= __clk_speculate_rates(child
, new_rate
);
1304 if (ret
& NOTIFY_STOP_MASK
)
1312 static void clk_calc_subtree(struct clk_core
*core
, unsigned long new_rate
,
1313 struct clk_core
*new_parent
, u8 p_index
)
1315 struct clk_core
*child
;
1317 core
->new_rate
= new_rate
;
1318 core
->new_parent
= new_parent
;
1319 core
->new_parent_index
= p_index
;
1320 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1321 core
->new_child
= NULL
;
1322 if (new_parent
&& new_parent
!= core
->parent
)
1323 new_parent
->new_child
= core
;
1325 hlist_for_each_entry(child
, &core
->children
, child_node
) {
1326 child
->new_rate
= clk_recalc(child
, new_rate
);
1327 clk_calc_subtree(child
, child
->new_rate
, NULL
, 0);
1332 * calculate the new rates returning the topmost clock that has to be
1335 static struct clk_core
*clk_calc_new_rates(struct clk_core
*core
,
1338 struct clk_core
*top
= core
;
1339 struct clk_core
*old_parent
, *parent
;
1340 unsigned long best_parent_rate
= 0;
1341 unsigned long new_rate
;
1342 unsigned long min_rate
;
1343 unsigned long max_rate
;
1348 if (IS_ERR_OR_NULL(core
))
1351 /* save parent rate, if it exists */
1352 parent
= old_parent
= core
->parent
;
1354 best_parent_rate
= parent
->rate
;
1356 clk_core_get_boundaries(core
, &min_rate
, &max_rate
);
1358 /* find the closest rate and parent clk/rate */
1359 if (core
->ops
->determine_rate
) {
1360 struct clk_rate_request req
;
1363 req
.min_rate
= min_rate
;
1364 req
.max_rate
= max_rate
;
1366 req
.best_parent_hw
= parent
->hw
;
1367 req
.best_parent_rate
= parent
->rate
;
1369 req
.best_parent_hw
= NULL
;
1370 req
.best_parent_rate
= 0;
1373 ret
= core
->ops
->determine_rate(core
->hw
, &req
);
1377 best_parent_rate
= req
.best_parent_rate
;
1378 new_rate
= req
.rate
;
1379 parent
= req
.best_parent_hw
? req
.best_parent_hw
->core
: NULL
;
1380 } else if (core
->ops
->round_rate
) {
1381 ret
= core
->ops
->round_rate(core
->hw
, rate
,
1387 if (new_rate
< min_rate
|| new_rate
> max_rate
)
1389 } else if (!parent
|| !(core
->flags
& CLK_SET_RATE_PARENT
)) {
1390 /* pass-through clock without adjustable parent */
1391 core
->new_rate
= core
->rate
;
1394 /* pass-through clock with adjustable parent */
1395 top
= clk_calc_new_rates(parent
, rate
);
1396 new_rate
= parent
->new_rate
;
1400 /* some clocks must be gated to change parent */
1401 if (parent
!= old_parent
&&
1402 (core
->flags
& CLK_SET_PARENT_GATE
) && core
->prepare_count
) {
1403 pr_debug("%s: %s not gated but wants to reparent\n",
1404 __func__
, core
->name
);
1408 /* try finding the new parent index */
1409 if (parent
&& core
->num_parents
> 1) {
1410 p_index
= clk_fetch_parent_index(core
, parent
);
1412 pr_debug("%s: clk %s can not be parent of clk %s\n",
1413 __func__
, parent
->name
, core
->name
);
1418 if ((core
->flags
& CLK_SET_RATE_PARENT
) && parent
&&
1419 best_parent_rate
!= parent
->rate
)
1420 top
= clk_calc_new_rates(parent
, best_parent_rate
);
1423 clk_calc_subtree(core
, new_rate
, parent
, p_index
);
1429 * Notify about rate changes in a subtree. Always walk down the whole tree
1430 * so that in case of an error we can walk down the whole tree again and
1433 static struct clk_core
*clk_propagate_rate_change(struct clk_core
*core
,
1434 unsigned long event
)
1436 struct clk_core
*child
, *tmp_clk
, *fail_clk
= NULL
;
1437 int ret
= NOTIFY_DONE
;
1439 if (core
->rate
== core
->new_rate
)
1442 if (core
->notifier_count
) {
1443 ret
= __clk_notify(core
, event
, core
->rate
, core
->new_rate
);
1444 if (ret
& NOTIFY_STOP_MASK
)
1448 hlist_for_each_entry(child
, &core
->children
, child_node
) {
1449 /* Skip children who will be reparented to another clock */
1450 if (child
->new_parent
&& child
->new_parent
!= core
)
1452 tmp_clk
= clk_propagate_rate_change(child
, event
);
1457 /* handle the new child who might not be in core->children yet */
1458 if (core
->new_child
) {
1459 tmp_clk
= clk_propagate_rate_change(core
->new_child
, event
);
1468 * walk down a subtree and set the new rates notifying the rate
1471 static void clk_change_rate(struct clk_core
*core
)
1473 struct clk_core
*child
;
1474 struct hlist_node
*tmp
;
1475 unsigned long old_rate
;
1476 unsigned long best_parent_rate
= 0;
1477 bool skip_set_rate
= false;
1478 struct clk_core
*old_parent
;
1479 struct clk_core
*parent
= NULL
;
1481 old_rate
= core
->rate
;
1483 if (core
->new_parent
) {
1484 parent
= core
->new_parent
;
1485 best_parent_rate
= core
->new_parent
->rate
;
1486 } else if (core
->parent
) {
1487 parent
= core
->parent
;
1488 best_parent_rate
= core
->parent
->rate
;
1491 if (core
->flags
& CLK_SET_RATE_UNGATE
) {
1492 unsigned long flags
;
1494 clk_core_prepare(core
);
1495 flags
= clk_enable_lock();
1496 clk_core_enable(core
);
1497 clk_enable_unlock(flags
);
1500 if (core
->new_parent
&& core
->new_parent
!= core
->parent
) {
1501 old_parent
= __clk_set_parent_before(core
, core
->new_parent
);
1502 trace_clk_set_parent(core
, core
->new_parent
);
1504 if (core
->ops
->set_rate_and_parent
) {
1505 skip_set_rate
= true;
1506 core
->ops
->set_rate_and_parent(core
->hw
, core
->new_rate
,
1508 core
->new_parent_index
);
1509 } else if (core
->ops
->set_parent
) {
1510 core
->ops
->set_parent(core
->hw
, core
->new_parent_index
);
1513 trace_clk_set_parent_complete(core
, core
->new_parent
);
1514 __clk_set_parent_after(core
, core
->new_parent
, old_parent
);
1517 if (core
->flags
& CLK_OPS_PARENT_ENABLE
)
1518 clk_core_prepare_enable(parent
);
1520 trace_clk_set_rate(core
, core
->new_rate
);
1522 if (!skip_set_rate
&& core
->ops
->set_rate
)
1523 core
->ops
->set_rate(core
->hw
, core
->new_rate
, best_parent_rate
);
1525 trace_clk_set_rate_complete(core
, core
->new_rate
);
1527 core
->rate
= clk_recalc(core
, best_parent_rate
);
1529 if (core
->flags
& CLK_SET_RATE_UNGATE
) {
1530 unsigned long flags
;
1532 flags
= clk_enable_lock();
1533 clk_core_disable(core
);
1534 clk_enable_unlock(flags
);
1535 clk_core_unprepare(core
);
1538 if (core
->flags
& CLK_OPS_PARENT_ENABLE
)
1539 clk_core_disable_unprepare(parent
);
1541 if (core
->notifier_count
&& old_rate
!= core
->rate
)
1542 __clk_notify(core
, POST_RATE_CHANGE
, old_rate
, core
->rate
);
1544 if (core
->flags
& CLK_RECALC_NEW_RATES
)
1545 (void)clk_calc_new_rates(core
, core
->new_rate
);
1548 * Use safe iteration, as change_rate can actually swap parents
1549 * for certain clock types.
1551 hlist_for_each_entry_safe(child
, tmp
, &core
->children
, child_node
) {
1552 /* Skip children who will be reparented to another clock */
1553 if (child
->new_parent
&& child
->new_parent
!= core
)
1555 clk_change_rate(child
);
1558 /* handle the new child who might not be in core->children yet */
1559 if (core
->new_child
)
1560 clk_change_rate(core
->new_child
);
1563 static int clk_core_set_rate_nolock(struct clk_core
*core
,
1564 unsigned long req_rate
)
1566 struct clk_core
*top
, *fail_clk
;
1567 unsigned long rate
= req_rate
;
1572 /* bail early if nothing to do */
1573 if (rate
== clk_core_get_rate_nolock(core
))
1576 if ((core
->flags
& CLK_SET_RATE_GATE
) && core
->prepare_count
)
1579 /* calculate new rates and get the topmost changed clock */
1580 top
= clk_calc_new_rates(core
, rate
);
1584 /* notify that we are about to change rates */
1585 fail_clk
= clk_propagate_rate_change(top
, PRE_RATE_CHANGE
);
1587 pr_debug("%s: failed to set %s rate\n", __func__
,
1589 clk_propagate_rate_change(top
, ABORT_RATE_CHANGE
);
1593 /* change the rates */
1594 clk_change_rate(top
);
1596 core
->req_rate
= req_rate
;
1602 * clk_set_rate - specify a new rate for clk
1603 * @clk: the clk whose rate is being changed
1604 * @rate: the new rate for clk
1606 * In the simplest case clk_set_rate will only adjust the rate of clk.
1608 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1609 * propagate up to clk's parent; whether or not this happens depends on the
1610 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1611 * after calling .round_rate then upstream parent propagation is ignored. If
1612 * *parent_rate comes back with a new rate for clk's parent then we propagate
1613 * up to clk's parent and set its rate. Upward propagation will continue
1614 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1615 * .round_rate stops requesting changes to clk's parent_rate.
1617 * Rate changes are accomplished via tree traversal that also recalculates the
1618 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
1620 * Returns 0 on success, -EERROR otherwise.
1622 int clk_set_rate(struct clk
*clk
, unsigned long rate
)
1629 /* prevent racing with updates to the clock topology */
1632 ret
= clk_core_set_rate_nolock(clk
->core
, rate
);
1634 clk_prepare_unlock();
1638 EXPORT_SYMBOL_GPL(clk_set_rate
);
1641 * clk_set_rate_range - set a rate range for a clock source
1642 * @clk: clock source
1643 * @min: desired minimum clock rate in Hz, inclusive
1644 * @max: desired maximum clock rate in Hz, inclusive
1646 * Returns success (0) or negative errno.
1648 int clk_set_rate_range(struct clk
*clk
, unsigned long min
, unsigned long max
)
1656 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
1657 __func__
, clk
->core
->name
, clk
->dev_id
, clk
->con_id
,
1664 if (min
!= clk
->min_rate
|| max
!= clk
->max_rate
) {
1665 clk
->min_rate
= min
;
1666 clk
->max_rate
= max
;
1667 ret
= clk_core_set_rate_nolock(clk
->core
, clk
->core
->req_rate
);
1670 clk_prepare_unlock();
1674 EXPORT_SYMBOL_GPL(clk_set_rate_range
);
1677 * clk_set_min_rate - set a minimum clock rate for a clock source
1678 * @clk: clock source
1679 * @rate: desired minimum clock rate in Hz, inclusive
1681 * Returns success (0) or negative errno.
1683 int clk_set_min_rate(struct clk
*clk
, unsigned long rate
)
1688 return clk_set_rate_range(clk
, rate
, clk
->max_rate
);
1690 EXPORT_SYMBOL_GPL(clk_set_min_rate
);
1693 * clk_set_max_rate - set a maximum clock rate for a clock source
1694 * @clk: clock source
1695 * @rate: desired maximum clock rate in Hz, inclusive
1697 * Returns success (0) or negative errno.
1699 int clk_set_max_rate(struct clk
*clk
, unsigned long rate
)
1704 return clk_set_rate_range(clk
, clk
->min_rate
, rate
);
1706 EXPORT_SYMBOL_GPL(clk_set_max_rate
);
1709 * clk_get_parent - return the parent of a clk
1710 * @clk: the clk whose parent gets returned
1712 * Simply returns clk->parent. Returns NULL if clk is NULL.
1714 struct clk
*clk_get_parent(struct clk
*clk
)
1722 /* TODO: Create a per-user clk and change callers to call clk_put */
1723 parent
= !clk
->core
->parent
? NULL
: clk
->core
->parent
->hw
->clk
;
1724 clk_prepare_unlock();
1728 EXPORT_SYMBOL_GPL(clk_get_parent
);
1730 static struct clk_core
*__clk_init_parent(struct clk_core
*core
)
1734 if (core
->num_parents
> 1 && core
->ops
->get_parent
)
1735 index
= core
->ops
->get_parent(core
->hw
);
1737 return clk_core_get_parent_by_index(core
, index
);
1740 static void clk_core_reparent(struct clk_core
*core
,
1741 struct clk_core
*new_parent
)
1743 clk_reparent(core
, new_parent
);
1744 __clk_recalc_accuracies(core
);
1745 __clk_recalc_rates(core
, POST_RATE_CHANGE
);
1748 void clk_hw_reparent(struct clk_hw
*hw
, struct clk_hw
*new_parent
)
1753 clk_core_reparent(hw
->core
, !new_parent
? NULL
: new_parent
->core
);
1757 * clk_has_parent - check if a clock is a possible parent for another
1758 * @clk: clock source
1759 * @parent: parent clock source
1761 * This function can be used in drivers that need to check that a clock can be
1762 * the parent of another without actually changing the parent.
1764 * Returns true if @parent is a possible parent for @clk, false otherwise.
1766 bool clk_has_parent(struct clk
*clk
, struct clk
*parent
)
1768 struct clk_core
*core
, *parent_core
;
1771 /* NULL clocks should be nops, so return success if either is NULL. */
1772 if (!clk
|| !parent
)
1776 parent_core
= parent
->core
;
1778 /* Optimize for the case where the parent is already the parent. */
1779 if (core
->parent
== parent_core
)
1782 for (i
= 0; i
< core
->num_parents
; i
++)
1783 if (strcmp(core
->parent_names
[i
], parent_core
->name
) == 0)
1788 EXPORT_SYMBOL_GPL(clk_has_parent
);
1790 static int clk_core_set_parent(struct clk_core
*core
, struct clk_core
*parent
)
1794 unsigned long p_rate
= 0;
1799 /* prevent racing with updates to the clock topology */
1802 if (core
->parent
== parent
)
1805 /* verify ops for for multi-parent clks */
1806 if ((core
->num_parents
> 1) && (!core
->ops
->set_parent
)) {
1811 /* check that we are allowed to re-parent if the clock is in use */
1812 if ((core
->flags
& CLK_SET_PARENT_GATE
) && core
->prepare_count
) {
1817 /* try finding the new parent index */
1819 p_index
= clk_fetch_parent_index(core
, parent
);
1821 pr_debug("%s: clk %s can not be parent of clk %s\n",
1822 __func__
, parent
->name
, core
->name
);
1826 p_rate
= parent
->rate
;
1829 /* propagate PRE_RATE_CHANGE notifications */
1830 ret
= __clk_speculate_rates(core
, p_rate
);
1832 /* abort if a driver objects */
1833 if (ret
& NOTIFY_STOP_MASK
)
1836 /* do the re-parent */
1837 ret
= __clk_set_parent(core
, parent
, p_index
);
1839 /* propagate rate an accuracy recalculation accordingly */
1841 __clk_recalc_rates(core
, ABORT_RATE_CHANGE
);
1843 __clk_recalc_rates(core
, POST_RATE_CHANGE
);
1844 __clk_recalc_accuracies(core
);
1848 clk_prepare_unlock();
1854 * clk_set_parent - switch the parent of a mux clk
1855 * @clk: the mux clk whose input we are switching
1856 * @parent: the new input to clk
1858 * Re-parent clk to use parent as its new input source. If clk is in
1859 * prepared state, the clk will get enabled for the duration of this call. If
1860 * that's not acceptable for a specific clk (Eg: the consumer can't handle
1861 * that, the reparenting is glitchy in hardware, etc), use the
1862 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
1864 * After successfully changing clk's parent clk_set_parent will update the
1865 * clk topology, sysfs topology and propagate rate recalculation via
1866 * __clk_recalc_rates.
1868 * Returns 0 on success, -EERROR otherwise.
1870 int clk_set_parent(struct clk
*clk
, struct clk
*parent
)
1875 return clk_core_set_parent(clk
->core
, parent
? parent
->core
: NULL
);
1877 EXPORT_SYMBOL_GPL(clk_set_parent
);
1880 * clk_set_phase - adjust the phase shift of a clock signal
1881 * @clk: clock signal source
1882 * @degrees: number of degrees the signal is shifted
1884 * Shifts the phase of a clock signal by the specified
1885 * degrees. Returns 0 on success, -EERROR otherwise.
1887 * This function makes no distinction about the input or reference
1888 * signal that we adjust the clock signal phase against. For example
1889 * phase locked-loop clock signal generators we may shift phase with
1890 * respect to feedback clock signal input, but for other cases the
1891 * clock phase may be shifted with respect to some other, unspecified
1894 * Additionally the concept of phase shift does not propagate through
1895 * the clock tree hierarchy, which sets it apart from clock rates and
1896 * clock accuracy. A parent clock phase attribute does not have an
1897 * impact on the phase attribute of a child clock.
1899 int clk_set_phase(struct clk
*clk
, int degrees
)
1906 /* sanity check degrees */
1913 trace_clk_set_phase(clk
->core
, degrees
);
1915 if (clk
->core
->ops
->set_phase
)
1916 ret
= clk
->core
->ops
->set_phase(clk
->core
->hw
, degrees
);
1918 trace_clk_set_phase_complete(clk
->core
, degrees
);
1921 clk
->core
->phase
= degrees
;
1923 clk_prepare_unlock();
1927 EXPORT_SYMBOL_GPL(clk_set_phase
);
1929 static int clk_core_get_phase(struct clk_core
*core
)
1935 clk_prepare_unlock();
1941 * clk_get_phase - return the phase shift of a clock signal
1942 * @clk: clock signal source
1944 * Returns the phase shift of a clock node in degrees, otherwise returns
1947 int clk_get_phase(struct clk
*clk
)
1952 return clk_core_get_phase(clk
->core
);
1954 EXPORT_SYMBOL_GPL(clk_get_phase
);
1957 * clk_is_match - check if two clk's point to the same hardware clock
1958 * @p: clk compared against q
1959 * @q: clk compared against p
1961 * Returns true if the two struct clk pointers both point to the same hardware
1962 * clock node. Put differently, returns true if struct clk *p and struct clk *q
1963 * share the same struct clk_core object.
1965 * Returns false otherwise. Note that two NULL clks are treated as matching.
1967 bool clk_is_match(const struct clk
*p
, const struct clk
*q
)
1969 /* trivial case: identical struct clk's or both NULL */
1973 /* true if clk->core pointers match. Avoid dereferencing garbage */
1974 if (!IS_ERR_OR_NULL(p
) && !IS_ERR_OR_NULL(q
))
1975 if (p
->core
== q
->core
)
1980 EXPORT_SYMBOL_GPL(clk_is_match
);
1982 /*** debugfs support ***/
1984 #ifdef CONFIG_DEBUG_FS
1985 #include <linux/debugfs.h>
1987 static struct dentry
*rootdir
;
1988 static int inited
= 0;
1989 static DEFINE_MUTEX(clk_debug_lock
);
1990 static HLIST_HEAD(clk_debug_list
);
1992 static struct hlist_head
*all_lists
[] = {
1998 static struct hlist_head
*orphan_list
[] = {
2003 static void clk_summary_show_one(struct seq_file
*s
, struct clk_core
*c
,
2009 seq_printf(s
, "%*s%-*s %11d %12d %11lu %10lu %-3d\n",
2011 30 - level
* 3, c
->name
,
2012 c
->enable_count
, c
->prepare_count
, clk_core_get_rate(c
),
2013 clk_core_get_accuracy(c
), clk_core_get_phase(c
));
2016 static void clk_summary_show_subtree(struct seq_file
*s
, struct clk_core
*c
,
2019 struct clk_core
*child
;
2024 clk_summary_show_one(s
, c
, level
);
2026 hlist_for_each_entry(child
, &c
->children
, child_node
)
2027 clk_summary_show_subtree(s
, child
, level
+ 1);
2030 static int clk_summary_show(struct seq_file
*s
, void *data
)
2033 struct hlist_head
**lists
= (struct hlist_head
**)s
->private;
2035 seq_puts(s
, " clock enable_cnt prepare_cnt rate accuracy phase\n");
2036 seq_puts(s
, "----------------------------------------------------------------------------------------\n");
2040 for (; *lists
; lists
++)
2041 hlist_for_each_entry(c
, *lists
, child_node
)
2042 clk_summary_show_subtree(s
, c
, 0);
2044 clk_prepare_unlock();
2050 static int clk_summary_open(struct inode
*inode
, struct file
*file
)
2052 return single_open(file
, clk_summary_show
, inode
->i_private
);
2055 static const struct file_operations clk_summary_fops
= {
2056 .open
= clk_summary_open
,
2058 .llseek
= seq_lseek
,
2059 .release
= single_release
,
2062 static void clk_dump_one(struct seq_file
*s
, struct clk_core
*c
, int level
)
2067 /* This should be JSON format, i.e. elements separated with a comma */
2068 seq_printf(s
, "\"%s\": { ", c
->name
);
2069 seq_printf(s
, "\"enable_count\": %d,", c
->enable_count
);
2070 seq_printf(s
, "\"prepare_count\": %d,", c
->prepare_count
);
2071 seq_printf(s
, "\"rate\": %lu,", clk_core_get_rate(c
));
2072 seq_printf(s
, "\"accuracy\": %lu,", clk_core_get_accuracy(c
));
2073 seq_printf(s
, "\"phase\": %d", clk_core_get_phase(c
));
2076 static void clk_dump_subtree(struct seq_file
*s
, struct clk_core
*c
, int level
)
2078 struct clk_core
*child
;
2083 clk_dump_one(s
, c
, level
);
2085 hlist_for_each_entry(child
, &c
->children
, child_node
) {
2087 clk_dump_subtree(s
, child
, level
+ 1);
2093 static int clk_dump(struct seq_file
*s
, void *data
)
2096 bool first_node
= true;
2097 struct hlist_head
**lists
= (struct hlist_head
**)s
->private;
2102 for (; *lists
; lists
++) {
2103 hlist_for_each_entry(c
, *lists
, child_node
) {
2107 clk_dump_subtree(s
, c
, 0);
2111 clk_prepare_unlock();
2118 static int clk_dump_open(struct inode
*inode
, struct file
*file
)
2120 return single_open(file
, clk_dump
, inode
->i_private
);
2123 static const struct file_operations clk_dump_fops
= {
2124 .open
= clk_dump_open
,
2126 .llseek
= seq_lseek
,
2127 .release
= single_release
,
2130 static int possible_parents_dump(struct seq_file
*s
, void *data
)
2132 struct clk_core
*core
= s
->private;
2135 for (i
= 0; i
< core
->num_parents
- 1; i
++)
2136 seq_printf(s
, "%s ", core
->parent_names
[i
]);
2138 seq_printf(s
, "%s\n", core
->parent_names
[i
]);
2143 static int possible_parents_open(struct inode
*inode
, struct file
*file
)
2145 return single_open(file
, possible_parents_dump
, inode
->i_private
);
2148 static const struct file_operations possible_parents_fops
= {
2149 .open
= possible_parents_open
,
2151 .llseek
= seq_lseek
,
2152 .release
= single_release
,
2155 static int clk_debug_create_one(struct clk_core
*core
, struct dentry
*pdentry
)
2160 if (!core
|| !pdentry
) {
2165 d
= debugfs_create_dir(core
->name
, pdentry
);
2171 d
= debugfs_create_u32("clk_rate", S_IRUGO
, core
->dentry
,
2172 (u32
*)&core
->rate
);
2176 d
= debugfs_create_u32("clk_accuracy", S_IRUGO
, core
->dentry
,
2177 (u32
*)&core
->accuracy
);
2181 d
= debugfs_create_u32("clk_phase", S_IRUGO
, core
->dentry
,
2182 (u32
*)&core
->phase
);
2186 d
= debugfs_create_x32("clk_flags", S_IRUGO
, core
->dentry
,
2187 (u32
*)&core
->flags
);
2191 d
= debugfs_create_u32("clk_prepare_count", S_IRUGO
, core
->dentry
,
2192 (u32
*)&core
->prepare_count
);
2196 d
= debugfs_create_u32("clk_enable_count", S_IRUGO
, core
->dentry
,
2197 (u32
*)&core
->enable_count
);
2201 d
= debugfs_create_u32("clk_notifier_count", S_IRUGO
, core
->dentry
,
2202 (u32
*)&core
->notifier_count
);
2206 if (core
->num_parents
> 1) {
2207 d
= debugfs_create_file("clk_possible_parents", S_IRUGO
,
2208 core
->dentry
, core
, &possible_parents_fops
);
2213 if (core
->ops
->debug_init
) {
2214 ret
= core
->ops
->debug_init(core
->hw
, core
->dentry
);
2223 debugfs_remove_recursive(core
->dentry
);
2224 core
->dentry
= NULL
;
2230 * clk_debug_register - add a clk node to the debugfs clk directory
2231 * @core: the clk being added to the debugfs clk directory
2233 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
2234 * initialized. Otherwise it bails out early since the debugfs clk directory
2235 * will be created lazily by clk_debug_init as part of a late_initcall.
2237 static int clk_debug_register(struct clk_core
*core
)
2241 mutex_lock(&clk_debug_lock
);
2242 hlist_add_head(&core
->debug_node
, &clk_debug_list
);
2247 ret
= clk_debug_create_one(core
, rootdir
);
2249 mutex_unlock(&clk_debug_lock
);
2255 * clk_debug_unregister - remove a clk node from the debugfs clk directory
2256 * @core: the clk being removed from the debugfs clk directory
2258 * Dynamically removes a clk and all its child nodes from the
2259 * debugfs clk directory if clk->dentry points to debugfs created by
2260 * clk_debug_register in __clk_core_init.
2262 static void clk_debug_unregister(struct clk_core
*core
)
2264 mutex_lock(&clk_debug_lock
);
2265 hlist_del_init(&core
->debug_node
);
2266 debugfs_remove_recursive(core
->dentry
);
2267 core
->dentry
= NULL
;
2268 mutex_unlock(&clk_debug_lock
);
2271 struct dentry
*clk_debugfs_add_file(struct clk_hw
*hw
, char *name
, umode_t mode
,
2272 void *data
, const struct file_operations
*fops
)
2274 struct dentry
*d
= NULL
;
2276 if (hw
->core
->dentry
)
2277 d
= debugfs_create_file(name
, mode
, hw
->core
->dentry
, data
,
2282 EXPORT_SYMBOL_GPL(clk_debugfs_add_file
);
2285 * clk_debug_init - lazily populate the debugfs clk directory
2287 * clks are often initialized very early during boot before memory can be
2288 * dynamically allocated and well before debugfs is setup. This function
2289 * populates the debugfs clk directory once at boot-time when we know that
2290 * debugfs is setup. It should only be called once at boot-time, all other clks
2291 * added dynamically will be done so with clk_debug_register.
2293 static int __init
clk_debug_init(void)
2295 struct clk_core
*core
;
2298 rootdir
= debugfs_create_dir("clk", NULL
);
2303 d
= debugfs_create_file("clk_summary", S_IRUGO
, rootdir
, &all_lists
,
2308 d
= debugfs_create_file("clk_dump", S_IRUGO
, rootdir
, &all_lists
,
2313 d
= debugfs_create_file("clk_orphan_summary", S_IRUGO
, rootdir
,
2314 &orphan_list
, &clk_summary_fops
);
2318 d
= debugfs_create_file("clk_orphan_dump", S_IRUGO
, rootdir
,
2319 &orphan_list
, &clk_dump_fops
);
2323 mutex_lock(&clk_debug_lock
);
2324 hlist_for_each_entry(core
, &clk_debug_list
, debug_node
)
2325 clk_debug_create_one(core
, rootdir
);
2328 mutex_unlock(&clk_debug_lock
);
2332 late_initcall(clk_debug_init
);
2334 static inline int clk_debug_register(struct clk_core
*core
) { return 0; }
2335 static inline void clk_debug_reparent(struct clk_core
*core
,
2336 struct clk_core
*new_parent
)
2339 static inline void clk_debug_unregister(struct clk_core
*core
)
2345 * __clk_core_init - initialize the data structures in a struct clk_core
2346 * @core: clk_core being initialized
2348 * Initializes the lists in struct clk_core, queries the hardware for the
2349 * parent and rate and sets them both.
2351 static int __clk_core_init(struct clk_core
*core
)
2354 struct clk_core
*orphan
;
2355 struct hlist_node
*tmp2
;
2363 /* check to see if a clock with this name is already registered */
2364 if (clk_core_lookup(core
->name
)) {
2365 pr_debug("%s: clk %s already initialized\n",
2366 __func__
, core
->name
);
2371 /* check that clk_ops are sane. See Documentation/clk.txt */
2372 if (core
->ops
->set_rate
&&
2373 !((core
->ops
->round_rate
|| core
->ops
->determine_rate
) &&
2374 core
->ops
->recalc_rate
)) {
2375 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
2376 __func__
, core
->name
);
2381 if (core
->ops
->set_parent
&& !core
->ops
->get_parent
) {
2382 pr_err("%s: %s must implement .get_parent & .set_parent\n",
2383 __func__
, core
->name
);
2388 if (core
->num_parents
> 1 && !core
->ops
->get_parent
) {
2389 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
2390 __func__
, core
->name
);
2395 if (core
->ops
->set_rate_and_parent
&&
2396 !(core
->ops
->set_parent
&& core
->ops
->set_rate
)) {
2397 pr_err("%s: %s must implement .set_parent & .set_rate\n",
2398 __func__
, core
->name
);
2403 /* throw a WARN if any entries in parent_names are NULL */
2404 for (i
= 0; i
< core
->num_parents
; i
++)
2405 WARN(!core
->parent_names
[i
],
2406 "%s: invalid NULL in %s's .parent_names\n",
2407 __func__
, core
->name
);
2409 core
->parent
= __clk_init_parent(core
);
2412 * Populate core->parent if parent has already been clk_core_init'd. If
2413 * parent has not yet been clk_core_init'd then place clk in the orphan
2414 * list. If clk doesn't have any parents then place it in the root
2417 * Every time a new clk is clk_init'd then we walk the list of orphan
2418 * clocks and re-parent any that are children of the clock currently
2422 hlist_add_head(&core
->child_node
,
2423 &core
->parent
->children
);
2424 core
->orphan
= core
->parent
->orphan
;
2425 } else if (!core
->num_parents
) {
2426 hlist_add_head(&core
->child_node
, &clk_root_list
);
2427 core
->orphan
= false;
2429 hlist_add_head(&core
->child_node
, &clk_orphan_list
);
2430 core
->orphan
= true;
2434 * Set clk's accuracy. The preferred method is to use
2435 * .recalc_accuracy. For simple clocks and lazy developers the default
2436 * fallback is to use the parent's accuracy. If a clock doesn't have a
2437 * parent (or is orphaned) then accuracy is set to zero (perfect
2440 if (core
->ops
->recalc_accuracy
)
2441 core
->accuracy
= core
->ops
->recalc_accuracy(core
->hw
,
2442 __clk_get_accuracy(core
->parent
));
2443 else if (core
->parent
)
2444 core
->accuracy
= core
->parent
->accuracy
;
2450 * Since a phase is by definition relative to its parent, just
2451 * query the current clock phase, or just assume it's in phase.
2453 if (core
->ops
->get_phase
)
2454 core
->phase
= core
->ops
->get_phase(core
->hw
);
2459 * Set clk's rate. The preferred method is to use .recalc_rate. For
2460 * simple clocks and lazy developers the default fallback is to use the
2461 * parent's rate. If a clock doesn't have a parent (or is orphaned)
2462 * then rate is set to zero.
2464 if (core
->ops
->recalc_rate
)
2465 rate
= core
->ops
->recalc_rate(core
->hw
,
2466 clk_core_get_rate_nolock(core
->parent
));
2467 else if (core
->parent
)
2468 rate
= core
->parent
->rate
;
2471 core
->rate
= core
->req_rate
= rate
;
2474 * walk the list of orphan clocks and reparent any that newly finds a
2477 hlist_for_each_entry_safe(orphan
, tmp2
, &clk_orphan_list
, child_node
) {
2478 struct clk_core
*parent
= __clk_init_parent(orphan
);
2481 * we could call __clk_set_parent, but that would result in a
2482 * redundant call to the .set_rate op, if it exists
2485 __clk_set_parent_before(orphan
, parent
);
2486 __clk_set_parent_after(orphan
, parent
, NULL
);
2487 __clk_recalc_accuracies(orphan
);
2488 __clk_recalc_rates(orphan
, 0);
2493 * optional platform-specific magic
2495 * The .init callback is not used by any of the basic clock types, but
2496 * exists for weird hardware that must perform initialization magic.
2497 * Please consider other ways of solving initialization problems before
2498 * using this callback, as its use is discouraged.
2500 if (core
->ops
->init
)
2501 core
->ops
->init(core
->hw
);
2503 if (core
->flags
& CLK_IS_CRITICAL
) {
2504 unsigned long flags
;
2506 clk_core_prepare(core
);
2508 flags
= clk_enable_lock();
2509 clk_core_enable(core
);
2510 clk_enable_unlock(flags
);
2513 kref_init(&core
->ref
);
2515 clk_prepare_unlock();
2518 clk_debug_register(core
);
2523 struct clk
*__clk_create_clk(struct clk_hw
*hw
, const char *dev_id
,
2528 /* This is to allow this function to be chained to others */
2529 if (IS_ERR_OR_NULL(hw
))
2530 return ERR_CAST(hw
);
2532 clk
= kzalloc(sizeof(*clk
), GFP_KERNEL
);
2534 return ERR_PTR(-ENOMEM
);
2536 clk
->core
= hw
->core
;
2537 clk
->dev_id
= dev_id
;
2538 clk
->con_id
= kstrdup_const(con_id
, GFP_KERNEL
);
2539 clk
->max_rate
= ULONG_MAX
;
2542 hlist_add_head(&clk
->clks_node
, &hw
->core
->clks
);
2543 clk_prepare_unlock();
2548 void __clk_free_clk(struct clk
*clk
)
2551 hlist_del(&clk
->clks_node
);
2552 clk_prepare_unlock();
2554 kfree_const(clk
->con_id
);
2559 * clk_register - allocate a new clock, register it and return an opaque cookie
2560 * @dev: device that is registering this clock
2561 * @hw: link to hardware-specific clock data
2563 * clk_register is the primary interface for populating the clock tree with new
2564 * clock nodes. It returns a pointer to the newly allocated struct clk which
2565 * cannot be dereferenced by driver code but may be used in conjunction with the
2566 * rest of the clock API. In the event of an error clk_register will return an
2567 * error code; drivers must test for an error code after calling clk_register.
2569 struct clk
*clk_register(struct device
*dev
, struct clk_hw
*hw
)
2572 struct clk_core
*core
;
2574 core
= kzalloc(sizeof(*core
), GFP_KERNEL
);
2580 core
->name
= kstrdup_const(hw
->init
->name
, GFP_KERNEL
);
2585 core
->ops
= hw
->init
->ops
;
2586 if (dev
&& dev
->driver
)
2587 core
->owner
= dev
->driver
->owner
;
2589 core
->flags
= hw
->init
->flags
;
2590 core
->num_parents
= hw
->init
->num_parents
;
2592 core
->max_rate
= ULONG_MAX
;
2595 /* allocate local copy in case parent_names is __initdata */
2596 core
->parent_names
= kcalloc(core
->num_parents
, sizeof(char *),
2599 if (!core
->parent_names
) {
2601 goto fail_parent_names
;
2605 /* copy each string name in case parent_names is __initdata */
2606 for (i
= 0; i
< core
->num_parents
; i
++) {
2607 core
->parent_names
[i
] = kstrdup_const(hw
->init
->parent_names
[i
],
2609 if (!core
->parent_names
[i
]) {
2611 goto fail_parent_names_copy
;
2615 /* avoid unnecessary string look-ups of clk_core's possible parents. */
2616 core
->parents
= kcalloc(core
->num_parents
, sizeof(*core
->parents
),
2618 if (!core
->parents
) {
2623 INIT_HLIST_HEAD(&core
->clks
);
2625 hw
->clk
= __clk_create_clk(hw
, NULL
, NULL
);
2626 if (IS_ERR(hw
->clk
)) {
2627 ret
= PTR_ERR(hw
->clk
);
2631 ret
= __clk_core_init(core
);
2635 __clk_free_clk(hw
->clk
);
2639 kfree(core
->parents
);
2640 fail_parent_names_copy
:
2642 kfree_const(core
->parent_names
[i
]);
2643 kfree(core
->parent_names
);
2645 kfree_const(core
->name
);
2649 return ERR_PTR(ret
);
2651 EXPORT_SYMBOL_GPL(clk_register
);
2654 * clk_hw_register - register a clk_hw and return an error code
2655 * @dev: device that is registering this clock
2656 * @hw: link to hardware-specific clock data
2658 * clk_hw_register is the primary interface for populating the clock tree with
2659 * new clock nodes. It returns an integer equal to zero indicating success or
2660 * less than zero indicating failure. Drivers must test for an error code after
2661 * calling clk_hw_register().
2663 int clk_hw_register(struct device
*dev
, struct clk_hw
*hw
)
2665 return PTR_ERR_OR_ZERO(clk_register(dev
, hw
));
2667 EXPORT_SYMBOL_GPL(clk_hw_register
);
2669 /* Free memory allocated for a clock. */
2670 static void __clk_release(struct kref
*ref
)
2672 struct clk_core
*core
= container_of(ref
, struct clk_core
, ref
);
2673 int i
= core
->num_parents
;
2675 lockdep_assert_held(&prepare_lock
);
2677 kfree(core
->parents
);
2679 kfree_const(core
->parent_names
[i
]);
2681 kfree(core
->parent_names
);
2682 kfree_const(core
->name
);
2687 * Empty clk_ops for unregistered clocks. These are used temporarily
2688 * after clk_unregister() was called on a clock and until last clock
2689 * consumer calls clk_put() and the struct clk object is freed.
2691 static int clk_nodrv_prepare_enable(struct clk_hw
*hw
)
2696 static void clk_nodrv_disable_unprepare(struct clk_hw
*hw
)
2701 static int clk_nodrv_set_rate(struct clk_hw
*hw
, unsigned long rate
,
2702 unsigned long parent_rate
)
2707 static int clk_nodrv_set_parent(struct clk_hw
*hw
, u8 index
)
2712 static const struct clk_ops clk_nodrv_ops
= {
2713 .enable
= clk_nodrv_prepare_enable
,
2714 .disable
= clk_nodrv_disable_unprepare
,
2715 .prepare
= clk_nodrv_prepare_enable
,
2716 .unprepare
= clk_nodrv_disable_unprepare
,
2717 .set_rate
= clk_nodrv_set_rate
,
2718 .set_parent
= clk_nodrv_set_parent
,
2722 * clk_unregister - unregister a currently registered clock
2723 * @clk: clock to unregister
2725 void clk_unregister(struct clk
*clk
)
2727 unsigned long flags
;
2729 if (!clk
|| WARN_ON_ONCE(IS_ERR(clk
)))
2732 clk_debug_unregister(clk
->core
);
2736 if (clk
->core
->ops
== &clk_nodrv_ops
) {
2737 pr_err("%s: unregistered clock: %s\n", __func__
,
2742 * Assign empty clock ops for consumers that might still hold
2743 * a reference to this clock.
2745 flags
= clk_enable_lock();
2746 clk
->core
->ops
= &clk_nodrv_ops
;
2747 clk_enable_unlock(flags
);
2749 if (!hlist_empty(&clk
->core
->children
)) {
2750 struct clk_core
*child
;
2751 struct hlist_node
*t
;
2753 /* Reparent all children to the orphan list. */
2754 hlist_for_each_entry_safe(child
, t
, &clk
->core
->children
,
2756 clk_core_set_parent(child
, NULL
);
2759 hlist_del_init(&clk
->core
->child_node
);
2761 if (clk
->core
->prepare_count
)
2762 pr_warn("%s: unregistering prepared clock: %s\n",
2763 __func__
, clk
->core
->name
);
2764 kref_put(&clk
->core
->ref
, __clk_release
);
2766 clk_prepare_unlock();
2768 EXPORT_SYMBOL_GPL(clk_unregister
);
2771 * clk_hw_unregister - unregister a currently registered clk_hw
2772 * @hw: hardware-specific clock data to unregister
2774 void clk_hw_unregister(struct clk_hw
*hw
)
2776 clk_unregister(hw
->clk
);
2778 EXPORT_SYMBOL_GPL(clk_hw_unregister
);
2780 static void devm_clk_release(struct device
*dev
, void *res
)
2782 clk_unregister(*(struct clk
**)res
);
2785 static void devm_clk_hw_release(struct device
*dev
, void *res
)
2787 clk_hw_unregister(*(struct clk_hw
**)res
);
2791 * devm_clk_register - resource managed clk_register()
2792 * @dev: device that is registering this clock
2793 * @hw: link to hardware-specific clock data
2795 * Managed clk_register(). Clocks returned from this function are
2796 * automatically clk_unregister()ed on driver detach. See clk_register() for
2799 struct clk
*devm_clk_register(struct device
*dev
, struct clk_hw
*hw
)
2804 clkp
= devres_alloc(devm_clk_release
, sizeof(*clkp
), GFP_KERNEL
);
2806 return ERR_PTR(-ENOMEM
);
2808 clk
= clk_register(dev
, hw
);
2811 devres_add(dev
, clkp
);
2818 EXPORT_SYMBOL_GPL(devm_clk_register
);
2821 * devm_clk_hw_register - resource managed clk_hw_register()
2822 * @dev: device that is registering this clock
2823 * @hw: link to hardware-specific clock data
2825 * Managed clk_hw_register(). Clocks registered by this function are
2826 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
2827 * for more information.
2829 int devm_clk_hw_register(struct device
*dev
, struct clk_hw
*hw
)
2831 struct clk_hw
**hwp
;
2834 hwp
= devres_alloc(devm_clk_hw_release
, sizeof(*hwp
), GFP_KERNEL
);
2838 ret
= clk_hw_register(dev
, hw
);
2841 devres_add(dev
, hwp
);
2848 EXPORT_SYMBOL_GPL(devm_clk_hw_register
);
2850 static int devm_clk_match(struct device
*dev
, void *res
, void *data
)
2852 struct clk
*c
= res
;
2858 static int devm_clk_hw_match(struct device
*dev
, void *res
, void *data
)
2860 struct clk_hw
*hw
= res
;
2868 * devm_clk_unregister - resource managed clk_unregister()
2869 * @clk: clock to unregister
2871 * Deallocate a clock allocated with devm_clk_register(). Normally
2872 * this function will not need to be called and the resource management
2873 * code will ensure that the resource is freed.
2875 void devm_clk_unregister(struct device
*dev
, struct clk
*clk
)
2877 WARN_ON(devres_release(dev
, devm_clk_release
, devm_clk_match
, clk
));
2879 EXPORT_SYMBOL_GPL(devm_clk_unregister
);
2882 * devm_clk_hw_unregister - resource managed clk_hw_unregister()
2883 * @dev: device that is unregistering the hardware-specific clock data
2884 * @hw: link to hardware-specific clock data
2886 * Unregister a clk_hw registered with devm_clk_hw_register(). Normally
2887 * this function will not need to be called and the resource management
2888 * code will ensure that the resource is freed.
2890 void devm_clk_hw_unregister(struct device
*dev
, struct clk_hw
*hw
)
2892 WARN_ON(devres_release(dev
, devm_clk_hw_release
, devm_clk_hw_match
,
2895 EXPORT_SYMBOL_GPL(devm_clk_hw_unregister
);
2900 int __clk_get(struct clk
*clk
)
2902 struct clk_core
*core
= !clk
? NULL
: clk
->core
;
2905 if (!try_module_get(core
->owner
))
2908 kref_get(&core
->ref
);
2913 void __clk_put(struct clk
*clk
)
2915 struct module
*owner
;
2917 if (!clk
|| WARN_ON_ONCE(IS_ERR(clk
)))
2922 hlist_del(&clk
->clks_node
);
2923 if (clk
->min_rate
> clk
->core
->req_rate
||
2924 clk
->max_rate
< clk
->core
->req_rate
)
2925 clk_core_set_rate_nolock(clk
->core
, clk
->core
->req_rate
);
2927 owner
= clk
->core
->owner
;
2928 kref_put(&clk
->core
->ref
, __clk_release
);
2930 clk_prepare_unlock();
2937 /*** clk rate change notifiers ***/
2940 * clk_notifier_register - add a clk rate change notifier
2941 * @clk: struct clk * to watch
2942 * @nb: struct notifier_block * with callback info
2944 * Request notification when clk's rate changes. This uses an SRCU
2945 * notifier because we want it to block and notifier unregistrations are
2946 * uncommon. The callbacks associated with the notifier must not
2947 * re-enter into the clk framework by calling any top-level clk APIs;
2948 * this will cause a nested prepare_lock mutex.
2950 * In all notification cases (pre, post and abort rate change) the original
2951 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
2952 * and the new frequency is passed via struct clk_notifier_data.new_rate.
2954 * clk_notifier_register() must be called from non-atomic context.
2955 * Returns -EINVAL if called with null arguments, -ENOMEM upon
2956 * allocation failure; otherwise, passes along the return value of
2957 * srcu_notifier_chain_register().
2959 int clk_notifier_register(struct clk
*clk
, struct notifier_block
*nb
)
2961 struct clk_notifier
*cn
;
2969 /* search the list of notifiers for this clk */
2970 list_for_each_entry(cn
, &clk_notifier_list
, node
)
2974 /* if clk wasn't in the notifier list, allocate new clk_notifier */
2975 if (cn
->clk
!= clk
) {
2976 cn
= kzalloc(sizeof(*cn
), GFP_KERNEL
);
2981 srcu_init_notifier_head(&cn
->notifier_head
);
2983 list_add(&cn
->node
, &clk_notifier_list
);
2986 ret
= srcu_notifier_chain_register(&cn
->notifier_head
, nb
);
2988 clk
->core
->notifier_count
++;
2991 clk_prepare_unlock();
2995 EXPORT_SYMBOL_GPL(clk_notifier_register
);
2998 * clk_notifier_unregister - remove a clk rate change notifier
2999 * @clk: struct clk *
3000 * @nb: struct notifier_block * with callback info
3002 * Request no further notification for changes to 'clk' and frees memory
3003 * allocated in clk_notifier_register.
3005 * Returns -EINVAL if called with null arguments; otherwise, passes
3006 * along the return value of srcu_notifier_chain_unregister().
3008 int clk_notifier_unregister(struct clk
*clk
, struct notifier_block
*nb
)
3010 struct clk_notifier
*cn
= NULL
;
3018 list_for_each_entry(cn
, &clk_notifier_list
, node
)
3022 if (cn
->clk
== clk
) {
3023 ret
= srcu_notifier_chain_unregister(&cn
->notifier_head
, nb
);
3025 clk
->core
->notifier_count
--;
3027 /* XXX the notifier code should handle this better */
3028 if (!cn
->notifier_head
.head
) {
3029 srcu_cleanup_notifier_head(&cn
->notifier_head
);
3030 list_del(&cn
->node
);
3038 clk_prepare_unlock();
3042 EXPORT_SYMBOL_GPL(clk_notifier_unregister
);
3046 * struct of_clk_provider - Clock provider registration structure
3047 * @link: Entry in global list of clock providers
3048 * @node: Pointer to device tree node of clock provider
3049 * @get: Get clock callback. Returns NULL or a struct clk for the
3050 * given clock specifier
3051 * @data: context pointer to be passed into @get callback
3053 struct of_clk_provider
{
3054 struct list_head link
;
3056 struct device_node
*node
;
3057 struct clk
*(*get
)(struct of_phandle_args
*clkspec
, void *data
);
3058 struct clk_hw
*(*get_hw
)(struct of_phandle_args
*clkspec
, void *data
);
3062 static const struct of_device_id __clk_of_table_sentinel
3063 __used
__section(__clk_of_table_end
);
3065 static LIST_HEAD(of_clk_providers
);
3066 static DEFINE_MUTEX(of_clk_mutex
);
3068 struct clk
*of_clk_src_simple_get(struct of_phandle_args
*clkspec
,
3073 EXPORT_SYMBOL_GPL(of_clk_src_simple_get
);
3075 struct clk_hw
*of_clk_hw_simple_get(struct of_phandle_args
*clkspec
, void *data
)
3079 EXPORT_SYMBOL_GPL(of_clk_hw_simple_get
);
3081 struct clk
*of_clk_src_onecell_get(struct of_phandle_args
*clkspec
, void *data
)
3083 struct clk_onecell_data
*clk_data
= data
;
3084 unsigned int idx
= clkspec
->args
[0];
3086 if (idx
>= clk_data
->clk_num
) {
3087 pr_err("%s: invalid clock index %u\n", __func__
, idx
);
3088 return ERR_PTR(-EINVAL
);
3091 return clk_data
->clks
[idx
];
3093 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get
);
3096 of_clk_hw_onecell_get(struct of_phandle_args
*clkspec
, void *data
)
3098 struct clk_hw_onecell_data
*hw_data
= data
;
3099 unsigned int idx
= clkspec
->args
[0];
3101 if (idx
>= hw_data
->num
) {
3102 pr_err("%s: invalid index %u\n", __func__
, idx
);
3103 return ERR_PTR(-EINVAL
);
3106 return hw_data
->hws
[idx
];
3108 EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get
);
3111 * of_clk_add_provider() - Register a clock provider for a node
3112 * @np: Device node pointer associated with clock provider
3113 * @clk_src_get: callback for decoding clock
3114 * @data: context pointer for @clk_src_get callback.
3116 int of_clk_add_provider(struct device_node
*np
,
3117 struct clk
*(*clk_src_get
)(struct of_phandle_args
*clkspec
,
3121 struct of_clk_provider
*cp
;
3124 cp
= kzalloc(sizeof(*cp
), GFP_KERNEL
);
3128 cp
->node
= of_node_get(np
);
3130 cp
->get
= clk_src_get
;
3132 mutex_lock(&of_clk_mutex
);
3133 list_add(&cp
->link
, &of_clk_providers
);
3134 mutex_unlock(&of_clk_mutex
);
3135 pr_debug("Added clock from %pOF\n", np
);
3137 ret
= of_clk_set_defaults(np
, true);
3139 of_clk_del_provider(np
);
3143 EXPORT_SYMBOL_GPL(of_clk_add_provider
);
3146 * of_clk_add_hw_provider() - Register a clock provider for a node
3147 * @np: Device node pointer associated with clock provider
3148 * @get: callback for decoding clk_hw
3149 * @data: context pointer for @get callback.
3151 int of_clk_add_hw_provider(struct device_node
*np
,
3152 struct clk_hw
*(*get
)(struct of_phandle_args
*clkspec
,
3156 struct of_clk_provider
*cp
;
3159 cp
= kzalloc(sizeof(*cp
), GFP_KERNEL
);
3163 cp
->node
= of_node_get(np
);
3167 mutex_lock(&of_clk_mutex
);
3168 list_add(&cp
->link
, &of_clk_providers
);
3169 mutex_unlock(&of_clk_mutex
);
3170 pr_debug("Added clk_hw provider from %pOF\n", np
);
3172 ret
= of_clk_set_defaults(np
, true);
3174 of_clk_del_provider(np
);
3178 EXPORT_SYMBOL_GPL(of_clk_add_hw_provider
);
3181 * of_clk_del_provider() - Remove a previously registered clock provider
3182 * @np: Device node pointer associated with clock provider
3184 void of_clk_del_provider(struct device_node
*np
)
3186 struct of_clk_provider
*cp
;
3188 mutex_lock(&of_clk_mutex
);
3189 list_for_each_entry(cp
, &of_clk_providers
, link
) {
3190 if (cp
->node
== np
) {
3191 list_del(&cp
->link
);
3192 of_node_put(cp
->node
);
3197 mutex_unlock(&of_clk_mutex
);
3199 EXPORT_SYMBOL_GPL(of_clk_del_provider
);
3201 static struct clk_hw
*
3202 __of_clk_get_hw_from_provider(struct of_clk_provider
*provider
,
3203 struct of_phandle_args
*clkspec
)
3207 if (provider
->get_hw
)
3208 return provider
->get_hw(clkspec
, provider
->data
);
3210 clk
= provider
->get(clkspec
, provider
->data
);
3212 return ERR_CAST(clk
);
3213 return __clk_get_hw(clk
);
3216 struct clk
*__of_clk_get_from_provider(struct of_phandle_args
*clkspec
,
3217 const char *dev_id
, const char *con_id
)
3219 struct of_clk_provider
*provider
;
3220 struct clk
*clk
= ERR_PTR(-EPROBE_DEFER
);
3224 return ERR_PTR(-EINVAL
);
3226 /* Check if we have such a provider in our array */
3227 mutex_lock(&of_clk_mutex
);
3228 list_for_each_entry(provider
, &of_clk_providers
, link
) {
3229 if (provider
->node
== clkspec
->np
) {
3230 hw
= __of_clk_get_hw_from_provider(provider
, clkspec
);
3231 clk
= __clk_create_clk(hw
, dev_id
, con_id
);
3235 if (!__clk_get(clk
)) {
3236 __clk_free_clk(clk
);
3237 clk
= ERR_PTR(-ENOENT
);
3243 mutex_unlock(&of_clk_mutex
);
3249 * of_clk_get_from_provider() - Lookup a clock from a clock provider
3250 * @clkspec: pointer to a clock specifier data structure
3252 * This function looks up a struct clk from the registered list of clock
3253 * providers, an input is a clock specifier data structure as returned
3254 * from the of_parse_phandle_with_args() function call.
3256 struct clk
*of_clk_get_from_provider(struct of_phandle_args
*clkspec
)
3258 return __of_clk_get_from_provider(clkspec
, NULL
, __func__
);
3260 EXPORT_SYMBOL_GPL(of_clk_get_from_provider
);
3263 * of_clk_get_parent_count() - Count the number of clocks a device node has
3264 * @np: device node to count
3266 * Returns: The number of clocks that are possible parents of this node
3268 unsigned int of_clk_get_parent_count(struct device_node
*np
)
3272 count
= of_count_phandle_with_args(np
, "clocks", "#clock-cells");
3278 EXPORT_SYMBOL_GPL(of_clk_get_parent_count
);
3280 const char *of_clk_get_parent_name(struct device_node
*np
, int index
)
3282 struct of_phandle_args clkspec
;
3283 struct property
*prop
;
3284 const char *clk_name
;
3291 rc
= of_parse_phandle_with_args(np
, "clocks", "#clock-cells", index
,
3296 index
= clkspec
.args_count
? clkspec
.args
[0] : 0;
3299 /* if there is an indices property, use it to transfer the index
3300 * specified into an array offset for the clock-output-names property.
3302 of_property_for_each_u32(clkspec
.np
, "clock-indices", prop
, vp
, pv
) {
3309 /* We went off the end of 'clock-indices' without finding it */
3313 if (of_property_read_string_index(clkspec
.np
, "clock-output-names",
3317 * Best effort to get the name if the clock has been
3318 * registered with the framework. If the clock isn't
3319 * registered, we return the node name as the name of
3320 * the clock as long as #clock-cells = 0.
3322 clk
= of_clk_get_from_provider(&clkspec
);
3324 if (clkspec
.args_count
== 0)
3325 clk_name
= clkspec
.np
->name
;
3329 clk_name
= __clk_get_name(clk
);
3335 of_node_put(clkspec
.np
);
3338 EXPORT_SYMBOL_GPL(of_clk_get_parent_name
);
3341 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
3343 * @np: Device node pointer associated with clock provider
3344 * @parents: pointer to char array that hold the parents' names
3345 * @size: size of the @parents array
3347 * Return: number of parents for the clock node.
3349 int of_clk_parent_fill(struct device_node
*np
, const char **parents
,
3354 while (i
< size
&& (parents
[i
] = of_clk_get_parent_name(np
, i
)) != NULL
)
3359 EXPORT_SYMBOL_GPL(of_clk_parent_fill
);
3361 struct clock_provider
{
3362 of_clk_init_cb_t clk_init_cb
;
3363 struct device_node
*np
;
3364 struct list_head node
;
3368 * This function looks for a parent clock. If there is one, then it
3369 * checks that the provider for this parent clock was initialized, in
3370 * this case the parent clock will be ready.
3372 static int parent_ready(struct device_node
*np
)
3377 struct clk
*clk
= of_clk_get(np
, i
);
3379 /* this parent is ready we can check the next one */
3386 /* at least one parent is not ready, we exit now */
3387 if (PTR_ERR(clk
) == -EPROBE_DEFER
)
3391 * Here we make assumption that the device tree is
3392 * written correctly. So an error means that there is
3393 * no more parent. As we didn't exit yet, then the
3394 * previous parent are ready. If there is no clock
3395 * parent, no need to wait for them, then we can
3396 * consider their absence as being ready
3403 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
3404 * @np: Device node pointer associated with clock provider
3405 * @index: clock index
3406 * @flags: pointer to clk_core->flags
3408 * Detects if the clock-critical property exists and, if so, sets the
3409 * corresponding CLK_IS_CRITICAL flag.
3411 * Do not use this function. It exists only for legacy Device Tree
3412 * bindings, such as the one-clock-per-node style that are outdated.
3413 * Those bindings typically put all clock data into .dts and the Linux
3414 * driver has no clock data, thus making it impossible to set this flag
3415 * correctly from the driver. Only those drivers may call
3416 * of_clk_detect_critical from their setup functions.
3418 * Return: error code or zero on success
3420 int of_clk_detect_critical(struct device_node
*np
,
3421 int index
, unsigned long *flags
)
3423 struct property
*prop
;
3430 of_property_for_each_u32(np
, "clock-critical", prop
, cur
, idx
)
3432 *flags
|= CLK_IS_CRITICAL
;
3438 * of_clk_init() - Scan and init clock providers from the DT
3439 * @matches: array of compatible values and init functions for providers.
3441 * This function scans the device tree for matching clock providers
3442 * and calls their initialization functions. It also does it by trying
3443 * to follow the dependencies.
3445 void __init
of_clk_init(const struct of_device_id
*matches
)
3447 const struct of_device_id
*match
;
3448 struct device_node
*np
;
3449 struct clock_provider
*clk_provider
, *next
;
3452 LIST_HEAD(clk_provider_list
);
3455 matches
= &__clk_of_table
;
3457 /* First prepare the list of the clocks providers */
3458 for_each_matching_node_and_match(np
, matches
, &match
) {
3459 struct clock_provider
*parent
;
3461 if (!of_device_is_available(np
))
3464 parent
= kzalloc(sizeof(*parent
), GFP_KERNEL
);
3466 list_for_each_entry_safe(clk_provider
, next
,
3467 &clk_provider_list
, node
) {
3468 list_del(&clk_provider
->node
);
3469 of_node_put(clk_provider
->np
);
3470 kfree(clk_provider
);
3476 parent
->clk_init_cb
= match
->data
;
3477 parent
->np
= of_node_get(np
);
3478 list_add_tail(&parent
->node
, &clk_provider_list
);
3481 while (!list_empty(&clk_provider_list
)) {
3482 is_init_done
= false;
3483 list_for_each_entry_safe(clk_provider
, next
,
3484 &clk_provider_list
, node
) {
3485 if (force
|| parent_ready(clk_provider
->np
)) {
3487 /* Don't populate platform devices */
3488 of_node_set_flag(clk_provider
->np
,
3491 clk_provider
->clk_init_cb(clk_provider
->np
);
3492 of_clk_set_defaults(clk_provider
->np
, true);
3494 list_del(&clk_provider
->node
);
3495 of_node_put(clk_provider
->np
);
3496 kfree(clk_provider
);
3497 is_init_done
= true;
3502 * We didn't manage to initialize any of the
3503 * remaining providers during the last loop, so now we
3504 * initialize all the remaining ones unconditionally
3505 * in case the clock parent was not mandatory