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/driver-api/clk.rst
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/pm_runtime.h>
25 #include <linux/sched.h>
26 #include <linux/clkdev.h>
30 static DEFINE_SPINLOCK(enable_lock
);
31 static DEFINE_MUTEX(prepare_lock
);
33 static struct task_struct
*prepare_owner
;
34 static struct task_struct
*enable_owner
;
36 static int prepare_refcnt
;
37 static int enable_refcnt
;
39 static HLIST_HEAD(clk_root_list
);
40 static HLIST_HEAD(clk_orphan_list
);
41 static LIST_HEAD(clk_notifier_list
);
43 /*** private data structures ***/
47 const struct clk_ops
*ops
;
51 struct clk_core
*parent
;
52 const char **parent_names
;
53 struct clk_core
**parents
;
57 unsigned long req_rate
;
58 unsigned long new_rate
;
59 struct clk_core
*new_parent
;
60 struct clk_core
*new_child
;
63 unsigned int enable_count
;
64 unsigned int prepare_count
;
65 unsigned int protect_count
;
66 unsigned long min_rate
;
67 unsigned long max_rate
;
68 unsigned long accuracy
;
71 struct hlist_head children
;
72 struct hlist_node child_node
;
73 struct hlist_head clks
;
74 unsigned int notifier_count
;
75 #ifdef CONFIG_DEBUG_FS
76 struct dentry
*dentry
;
77 struct hlist_node debug_node
;
82 #define CREATE_TRACE_POINTS
83 #include <trace/events/clk.h>
86 struct clk_core
*core
;
89 unsigned long min_rate
;
90 unsigned long max_rate
;
91 unsigned int exclusive_count
;
92 struct hlist_node clks_node
;
96 static int clk_pm_runtime_get(struct clk_core
*core
)
103 ret
= pm_runtime_get_sync(core
->dev
);
104 return ret
< 0 ? ret
: 0;
107 static void clk_pm_runtime_put(struct clk_core
*core
)
112 pm_runtime_put_sync(core
->dev
);
116 static void clk_prepare_lock(void)
118 if (!mutex_trylock(&prepare_lock
)) {
119 if (prepare_owner
== current
) {
123 mutex_lock(&prepare_lock
);
125 WARN_ON_ONCE(prepare_owner
!= NULL
);
126 WARN_ON_ONCE(prepare_refcnt
!= 0);
127 prepare_owner
= current
;
131 static void clk_prepare_unlock(void)
133 WARN_ON_ONCE(prepare_owner
!= current
);
134 WARN_ON_ONCE(prepare_refcnt
== 0);
136 if (--prepare_refcnt
)
138 prepare_owner
= NULL
;
139 mutex_unlock(&prepare_lock
);
142 static unsigned long clk_enable_lock(void)
143 __acquires(enable_lock
)
148 * On UP systems, spin_trylock_irqsave() always returns true, even if
149 * we already hold the lock. So, in that case, we rely only on
150 * reference counting.
152 if (!IS_ENABLED(CONFIG_SMP
) ||
153 !spin_trylock_irqsave(&enable_lock
, flags
)) {
154 if (enable_owner
== current
) {
156 __acquire(enable_lock
);
157 if (!IS_ENABLED(CONFIG_SMP
))
158 local_save_flags(flags
);
161 spin_lock_irqsave(&enable_lock
, flags
);
163 WARN_ON_ONCE(enable_owner
!= NULL
);
164 WARN_ON_ONCE(enable_refcnt
!= 0);
165 enable_owner
= current
;
170 static void clk_enable_unlock(unsigned long flags
)
171 __releases(enable_lock
)
173 WARN_ON_ONCE(enable_owner
!= current
);
174 WARN_ON_ONCE(enable_refcnt
== 0);
176 if (--enable_refcnt
) {
177 __release(enable_lock
);
181 spin_unlock_irqrestore(&enable_lock
, flags
);
184 static bool clk_core_rate_is_protected(struct clk_core
*core
)
186 return core
->protect_count
;
189 static bool clk_core_is_prepared(struct clk_core
*core
)
194 * .is_prepared is optional for clocks that can prepare
195 * fall back to software usage counter if it is missing
197 if (!core
->ops
->is_prepared
)
198 return core
->prepare_count
;
200 if (!clk_pm_runtime_get(core
)) {
201 ret
= core
->ops
->is_prepared(core
->hw
);
202 clk_pm_runtime_put(core
);
208 static bool clk_core_is_enabled(struct clk_core
*core
)
213 * .is_enabled is only mandatory for clocks that gate
214 * fall back to software usage counter if .is_enabled is missing
216 if (!core
->ops
->is_enabled
)
217 return core
->enable_count
;
220 * Check if clock controller's device is runtime active before
221 * calling .is_enabled callback. If not, assume that clock is
222 * disabled, because we might be called from atomic context, from
223 * which pm_runtime_get() is not allowed.
224 * This function is called mainly from clk_disable_unused_subtree,
225 * which ensures proper runtime pm activation of controller before
226 * taking enable spinlock, but the below check is needed if one tries
227 * to call it from other places.
230 pm_runtime_get_noresume(core
->dev
);
231 if (!pm_runtime_active(core
->dev
)) {
237 ret
= core
->ops
->is_enabled(core
->hw
);
240 pm_runtime_put(core
->dev
);
245 /*** helper functions ***/
247 const char *__clk_get_name(const struct clk
*clk
)
249 return !clk
? NULL
: clk
->core
->name
;
251 EXPORT_SYMBOL_GPL(__clk_get_name
);
253 const char *clk_hw_get_name(const struct clk_hw
*hw
)
255 return hw
->core
->name
;
257 EXPORT_SYMBOL_GPL(clk_hw_get_name
);
259 struct clk_hw
*__clk_get_hw(struct clk
*clk
)
261 return !clk
? NULL
: clk
->core
->hw
;
263 EXPORT_SYMBOL_GPL(__clk_get_hw
);
265 unsigned int clk_hw_get_num_parents(const struct clk_hw
*hw
)
267 return hw
->core
->num_parents
;
269 EXPORT_SYMBOL_GPL(clk_hw_get_num_parents
);
271 struct clk_hw
*clk_hw_get_parent(const struct clk_hw
*hw
)
273 return hw
->core
->parent
? hw
->core
->parent
->hw
: NULL
;
275 EXPORT_SYMBOL_GPL(clk_hw_get_parent
);
277 static struct clk_core
*__clk_lookup_subtree(const char *name
,
278 struct clk_core
*core
)
280 struct clk_core
*child
;
281 struct clk_core
*ret
;
283 if (!strcmp(core
->name
, name
))
286 hlist_for_each_entry(child
, &core
->children
, child_node
) {
287 ret
= __clk_lookup_subtree(name
, child
);
295 static struct clk_core
*clk_core_lookup(const char *name
)
297 struct clk_core
*root_clk
;
298 struct clk_core
*ret
;
303 /* search the 'proper' clk tree first */
304 hlist_for_each_entry(root_clk
, &clk_root_list
, child_node
) {
305 ret
= __clk_lookup_subtree(name
, root_clk
);
310 /* if not found, then search the orphan tree */
311 hlist_for_each_entry(root_clk
, &clk_orphan_list
, child_node
) {
312 ret
= __clk_lookup_subtree(name
, root_clk
);
320 static struct clk_core
*clk_core_get_parent_by_index(struct clk_core
*core
,
323 if (!core
|| index
>= core
->num_parents
)
326 if (!core
->parents
[index
])
327 core
->parents
[index
] =
328 clk_core_lookup(core
->parent_names
[index
]);
330 return core
->parents
[index
];
334 clk_hw_get_parent_by_index(const struct clk_hw
*hw
, unsigned int index
)
336 struct clk_core
*parent
;
338 parent
= clk_core_get_parent_by_index(hw
->core
, index
);
340 return !parent
? NULL
: parent
->hw
;
342 EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index
);
344 unsigned int __clk_get_enable_count(struct clk
*clk
)
346 return !clk
? 0 : clk
->core
->enable_count
;
349 static unsigned long clk_core_get_rate_nolock(struct clk_core
*core
)
360 if (!core
->num_parents
)
370 unsigned long clk_hw_get_rate(const struct clk_hw
*hw
)
372 return clk_core_get_rate_nolock(hw
->core
);
374 EXPORT_SYMBOL_GPL(clk_hw_get_rate
);
376 static unsigned long __clk_get_accuracy(struct clk_core
*core
)
381 return core
->accuracy
;
384 unsigned long __clk_get_flags(struct clk
*clk
)
386 return !clk
? 0 : clk
->core
->flags
;
388 EXPORT_SYMBOL_GPL(__clk_get_flags
);
390 unsigned long clk_hw_get_flags(const struct clk_hw
*hw
)
392 return hw
->core
->flags
;
394 EXPORT_SYMBOL_GPL(clk_hw_get_flags
);
396 bool clk_hw_is_prepared(const struct clk_hw
*hw
)
398 return clk_core_is_prepared(hw
->core
);
401 bool clk_hw_rate_is_protected(const struct clk_hw
*hw
)
403 return clk_core_rate_is_protected(hw
->core
);
406 bool clk_hw_is_enabled(const struct clk_hw
*hw
)
408 return clk_core_is_enabled(hw
->core
);
411 bool __clk_is_enabled(struct clk
*clk
)
416 return clk_core_is_enabled(clk
->core
);
418 EXPORT_SYMBOL_GPL(__clk_is_enabled
);
420 static bool mux_is_better_rate(unsigned long rate
, unsigned long now
,
421 unsigned long best
, unsigned long flags
)
423 if (flags
& CLK_MUX_ROUND_CLOSEST
)
424 return abs(now
- rate
) < abs(best
- rate
);
426 return now
<= rate
&& now
> best
;
429 int clk_mux_determine_rate_flags(struct clk_hw
*hw
,
430 struct clk_rate_request
*req
,
433 struct clk_core
*core
= hw
->core
, *parent
, *best_parent
= NULL
;
434 int i
, num_parents
, ret
;
435 unsigned long best
= 0;
436 struct clk_rate_request parent_req
= *req
;
438 /* if NO_REPARENT flag set, pass through to current parent */
439 if (core
->flags
& CLK_SET_RATE_NO_REPARENT
) {
440 parent
= core
->parent
;
441 if (core
->flags
& CLK_SET_RATE_PARENT
) {
442 ret
= __clk_determine_rate(parent
? parent
->hw
: NULL
,
447 best
= parent_req
.rate
;
449 best
= clk_core_get_rate_nolock(parent
);
451 best
= clk_core_get_rate_nolock(core
);
457 /* find the parent that can provide the fastest rate <= rate */
458 num_parents
= core
->num_parents
;
459 for (i
= 0; i
< num_parents
; i
++) {
460 parent
= clk_core_get_parent_by_index(core
, i
);
464 if (core
->flags
& CLK_SET_RATE_PARENT
) {
466 ret
= __clk_determine_rate(parent
->hw
, &parent_req
);
470 parent_req
.rate
= clk_core_get_rate_nolock(parent
);
473 if (mux_is_better_rate(req
->rate
, parent_req
.rate
,
475 best_parent
= parent
;
476 best
= parent_req
.rate
;
485 req
->best_parent_hw
= best_parent
->hw
;
486 req
->best_parent_rate
= best
;
491 EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags
);
493 struct clk
*__clk_lookup(const char *name
)
495 struct clk_core
*core
= clk_core_lookup(name
);
497 return !core
? NULL
: core
->hw
->clk
;
500 static void clk_core_get_boundaries(struct clk_core
*core
,
501 unsigned long *min_rate
,
502 unsigned long *max_rate
)
504 struct clk
*clk_user
;
506 *min_rate
= core
->min_rate
;
507 *max_rate
= core
->max_rate
;
509 hlist_for_each_entry(clk_user
, &core
->clks
, clks_node
)
510 *min_rate
= max(*min_rate
, clk_user
->min_rate
);
512 hlist_for_each_entry(clk_user
, &core
->clks
, clks_node
)
513 *max_rate
= min(*max_rate
, clk_user
->max_rate
);
516 void clk_hw_set_rate_range(struct clk_hw
*hw
, unsigned long min_rate
,
517 unsigned long max_rate
)
519 hw
->core
->min_rate
= min_rate
;
520 hw
->core
->max_rate
= max_rate
;
522 EXPORT_SYMBOL_GPL(clk_hw_set_rate_range
);
525 * Helper for finding best parent to provide a given frequency. This can be used
526 * directly as a determine_rate callback (e.g. for a mux), or from a more
527 * complex clock that may combine a mux with other operations.
529 int __clk_mux_determine_rate(struct clk_hw
*hw
,
530 struct clk_rate_request
*req
)
532 return clk_mux_determine_rate_flags(hw
, req
, 0);
534 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate
);
536 int __clk_mux_determine_rate_closest(struct clk_hw
*hw
,
537 struct clk_rate_request
*req
)
539 return clk_mux_determine_rate_flags(hw
, req
, CLK_MUX_ROUND_CLOSEST
);
541 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest
);
545 static void clk_core_rate_unprotect(struct clk_core
*core
)
547 lockdep_assert_held(&prepare_lock
);
552 if (WARN(core
->protect_count
== 0,
553 "%s already unprotected\n", core
->name
))
556 if (--core
->protect_count
> 0)
559 clk_core_rate_unprotect(core
->parent
);
562 static int clk_core_rate_nuke_protect(struct clk_core
*core
)
566 lockdep_assert_held(&prepare_lock
);
571 if (core
->protect_count
== 0)
574 ret
= core
->protect_count
;
575 core
->protect_count
= 1;
576 clk_core_rate_unprotect(core
);
582 * clk_rate_exclusive_put - release exclusivity over clock rate control
583 * @clk: the clk over which the exclusivity is released
585 * clk_rate_exclusive_put() completes a critical section during which a clock
586 * consumer cannot tolerate any other consumer making any operation on the
587 * clock which could result in a rate change or rate glitch. Exclusive clocks
588 * cannot have their rate changed, either directly or indirectly due to changes
589 * further up the parent chain of clocks. As a result, clocks up parent chain
590 * also get under exclusive control of the calling consumer.
592 * If exlusivity is claimed more than once on clock, even by the same consumer,
593 * the rate effectively gets locked as exclusivity can't be preempted.
595 * Calls to clk_rate_exclusive_put() must be balanced with calls to
596 * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
599 void clk_rate_exclusive_put(struct clk
*clk
)
607 * if there is something wrong with this consumer protect count, stop
608 * here before messing with the provider
610 if (WARN_ON(clk
->exclusive_count
<= 0))
613 clk_core_rate_unprotect(clk
->core
);
614 clk
->exclusive_count
--;
616 clk_prepare_unlock();
618 EXPORT_SYMBOL_GPL(clk_rate_exclusive_put
);
620 static void clk_core_rate_protect(struct clk_core
*core
)
622 lockdep_assert_held(&prepare_lock
);
627 if (core
->protect_count
== 0)
628 clk_core_rate_protect(core
->parent
);
630 core
->protect_count
++;
633 static void clk_core_rate_restore_protect(struct clk_core
*core
, int count
)
635 lockdep_assert_held(&prepare_lock
);
643 clk_core_rate_protect(core
);
644 core
->protect_count
= count
;
648 * clk_rate_exclusive_get - get exclusivity over the clk rate control
649 * @clk: the clk over which the exclusity of rate control is requested
651 * clk_rate_exlusive_get() begins a critical section during which a clock
652 * consumer cannot tolerate any other consumer making any operation on the
653 * clock which could result in a rate change or rate glitch. Exclusive clocks
654 * cannot have their rate changed, either directly or indirectly due to changes
655 * further up the parent chain of clocks. As a result, clocks up parent chain
656 * also get under exclusive control of the calling consumer.
658 * If exlusivity is claimed more than once on clock, even by the same consumer,
659 * the rate effectively gets locked as exclusivity can't be preempted.
661 * Calls to clk_rate_exclusive_get() should be balanced with calls to
662 * clk_rate_exclusive_put(). Calls to this function may sleep.
663 * Returns 0 on success, -EERROR otherwise
665 int clk_rate_exclusive_get(struct clk
*clk
)
671 clk_core_rate_protect(clk
->core
);
672 clk
->exclusive_count
++;
673 clk_prepare_unlock();
677 EXPORT_SYMBOL_GPL(clk_rate_exclusive_get
);
679 static void clk_core_unprepare(struct clk_core
*core
)
681 lockdep_assert_held(&prepare_lock
);
686 if (WARN(core
->prepare_count
== 0,
687 "%s already unprepared\n", core
->name
))
690 if (WARN(core
->prepare_count
== 1 && core
->flags
& CLK_IS_CRITICAL
,
691 "Unpreparing critical %s\n", core
->name
))
694 if (core
->flags
& CLK_SET_RATE_GATE
)
695 clk_core_rate_unprotect(core
);
697 if (--core
->prepare_count
> 0)
700 WARN(core
->enable_count
> 0, "Unpreparing enabled %s\n", core
->name
);
702 trace_clk_unprepare(core
);
704 if (core
->ops
->unprepare
)
705 core
->ops
->unprepare(core
->hw
);
707 clk_pm_runtime_put(core
);
709 trace_clk_unprepare_complete(core
);
710 clk_core_unprepare(core
->parent
);
713 static void clk_core_unprepare_lock(struct clk_core
*core
)
716 clk_core_unprepare(core
);
717 clk_prepare_unlock();
721 * clk_unprepare - undo preparation of a clock source
722 * @clk: the clk being unprepared
724 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
725 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
726 * if the operation may sleep. One example is a clk which is accessed over
727 * I2c. In the complex case a clk gate operation may require a fast and a slow
728 * part. It is this reason that clk_unprepare and clk_disable are not mutually
729 * exclusive. In fact clk_disable must be called before clk_unprepare.
731 void clk_unprepare(struct clk
*clk
)
733 if (IS_ERR_OR_NULL(clk
))
736 clk_core_unprepare_lock(clk
->core
);
738 EXPORT_SYMBOL_GPL(clk_unprepare
);
740 static int clk_core_prepare(struct clk_core
*core
)
744 lockdep_assert_held(&prepare_lock
);
749 if (core
->prepare_count
== 0) {
750 ret
= clk_pm_runtime_get(core
);
754 ret
= clk_core_prepare(core
->parent
);
758 trace_clk_prepare(core
);
760 if (core
->ops
->prepare
)
761 ret
= core
->ops
->prepare(core
->hw
);
763 trace_clk_prepare_complete(core
);
769 core
->prepare_count
++;
772 * CLK_SET_RATE_GATE is a special case of clock protection
773 * Instead of a consumer claiming exclusive rate control, it is
774 * actually the provider which prevents any consumer from making any
775 * operation which could result in a rate change or rate glitch while
776 * the clock is prepared.
778 if (core
->flags
& CLK_SET_RATE_GATE
)
779 clk_core_rate_protect(core
);
783 clk_core_unprepare(core
->parent
);
785 clk_pm_runtime_put(core
);
789 static int clk_core_prepare_lock(struct clk_core
*core
)
794 ret
= clk_core_prepare(core
);
795 clk_prepare_unlock();
801 * clk_prepare - prepare a clock source
802 * @clk: the clk being prepared
804 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
805 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
806 * operation may sleep. One example is a clk which is accessed over I2c. In
807 * the complex case a clk ungate operation may require a fast and a slow part.
808 * It is this reason that clk_prepare and clk_enable are not mutually
809 * exclusive. In fact clk_prepare must be called before clk_enable.
810 * Returns 0 on success, -EERROR otherwise.
812 int clk_prepare(struct clk
*clk
)
817 return clk_core_prepare_lock(clk
->core
);
819 EXPORT_SYMBOL_GPL(clk_prepare
);
821 static void clk_core_disable(struct clk_core
*core
)
823 lockdep_assert_held(&enable_lock
);
828 if (WARN(core
->enable_count
== 0, "%s already disabled\n", core
->name
))
831 if (WARN(core
->enable_count
== 1 && core
->flags
& CLK_IS_CRITICAL
,
832 "Disabling critical %s\n", core
->name
))
835 if (--core
->enable_count
> 0)
838 trace_clk_disable_rcuidle(core
);
840 if (core
->ops
->disable
)
841 core
->ops
->disable(core
->hw
);
843 trace_clk_disable_complete_rcuidle(core
);
845 clk_core_disable(core
->parent
);
848 static void clk_core_disable_lock(struct clk_core
*core
)
852 flags
= clk_enable_lock();
853 clk_core_disable(core
);
854 clk_enable_unlock(flags
);
858 * clk_disable - gate a clock
859 * @clk: the clk being gated
861 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
862 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
863 * clk if the operation is fast and will never sleep. One example is a
864 * SoC-internal clk which is controlled via simple register writes. In the
865 * complex case a clk gate operation may require a fast and a slow part. It is
866 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
867 * In fact clk_disable must be called before clk_unprepare.
869 void clk_disable(struct clk
*clk
)
871 if (IS_ERR_OR_NULL(clk
))
874 clk_core_disable_lock(clk
->core
);
876 EXPORT_SYMBOL_GPL(clk_disable
);
878 static int clk_core_enable(struct clk_core
*core
)
882 lockdep_assert_held(&enable_lock
);
887 if (WARN(core
->prepare_count
== 0,
888 "Enabling unprepared %s\n", core
->name
))
891 if (core
->enable_count
== 0) {
892 ret
= clk_core_enable(core
->parent
);
897 trace_clk_enable_rcuidle(core
);
899 if (core
->ops
->enable
)
900 ret
= core
->ops
->enable(core
->hw
);
902 trace_clk_enable_complete_rcuidle(core
);
905 clk_core_disable(core
->parent
);
910 core
->enable_count
++;
914 static int clk_core_enable_lock(struct clk_core
*core
)
919 flags
= clk_enable_lock();
920 ret
= clk_core_enable(core
);
921 clk_enable_unlock(flags
);
927 * clk_enable - ungate a clock
928 * @clk: the clk being ungated
930 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
931 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
932 * if the operation will never sleep. One example is a SoC-internal clk which
933 * is controlled via simple register writes. In the complex case a clk ungate
934 * operation may require a fast and a slow part. It is this reason that
935 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
936 * must be called before clk_enable. Returns 0 on success, -EERROR
939 int clk_enable(struct clk
*clk
)
944 return clk_core_enable_lock(clk
->core
);
946 EXPORT_SYMBOL_GPL(clk_enable
);
948 static int clk_core_prepare_enable(struct clk_core
*core
)
952 ret
= clk_core_prepare_lock(core
);
956 ret
= clk_core_enable_lock(core
);
958 clk_core_unprepare_lock(core
);
963 static void clk_core_disable_unprepare(struct clk_core
*core
)
965 clk_core_disable_lock(core
);
966 clk_core_unprepare_lock(core
);
969 static void clk_unprepare_unused_subtree(struct clk_core
*core
)
971 struct clk_core
*child
;
973 lockdep_assert_held(&prepare_lock
);
975 hlist_for_each_entry(child
, &core
->children
, child_node
)
976 clk_unprepare_unused_subtree(child
);
978 if (core
->prepare_count
)
981 if (core
->flags
& CLK_IGNORE_UNUSED
)
984 if (clk_pm_runtime_get(core
))
987 if (clk_core_is_prepared(core
)) {
988 trace_clk_unprepare(core
);
989 if (core
->ops
->unprepare_unused
)
990 core
->ops
->unprepare_unused(core
->hw
);
991 else if (core
->ops
->unprepare
)
992 core
->ops
->unprepare(core
->hw
);
993 trace_clk_unprepare_complete(core
);
996 clk_pm_runtime_put(core
);
999 static void clk_disable_unused_subtree(struct clk_core
*core
)
1001 struct clk_core
*child
;
1002 unsigned long flags
;
1004 lockdep_assert_held(&prepare_lock
);
1006 hlist_for_each_entry(child
, &core
->children
, child_node
)
1007 clk_disable_unused_subtree(child
);
1009 if (core
->flags
& CLK_OPS_PARENT_ENABLE
)
1010 clk_core_prepare_enable(core
->parent
);
1012 if (clk_pm_runtime_get(core
))
1015 flags
= clk_enable_lock();
1017 if (core
->enable_count
)
1020 if (core
->flags
& CLK_IGNORE_UNUSED
)
1024 * some gate clocks have special needs during the disable-unused
1025 * sequence. call .disable_unused if available, otherwise fall
1028 if (clk_core_is_enabled(core
)) {
1029 trace_clk_disable(core
);
1030 if (core
->ops
->disable_unused
)
1031 core
->ops
->disable_unused(core
->hw
);
1032 else if (core
->ops
->disable
)
1033 core
->ops
->disable(core
->hw
);
1034 trace_clk_disable_complete(core
);
1038 clk_enable_unlock(flags
);
1039 clk_pm_runtime_put(core
);
1041 if (core
->flags
& CLK_OPS_PARENT_ENABLE
)
1042 clk_core_disable_unprepare(core
->parent
);
1045 static bool clk_ignore_unused
;
1046 static int __init
clk_ignore_unused_setup(char *__unused
)
1048 clk_ignore_unused
= true;
1051 __setup("clk_ignore_unused", clk_ignore_unused_setup
);
1053 static int clk_disable_unused(void)
1055 struct clk_core
*core
;
1057 if (clk_ignore_unused
) {
1058 pr_warn("clk: Not disabling unused clocks\n");
1064 hlist_for_each_entry(core
, &clk_root_list
, child_node
)
1065 clk_disable_unused_subtree(core
);
1067 hlist_for_each_entry(core
, &clk_orphan_list
, child_node
)
1068 clk_disable_unused_subtree(core
);
1070 hlist_for_each_entry(core
, &clk_root_list
, child_node
)
1071 clk_unprepare_unused_subtree(core
);
1073 hlist_for_each_entry(core
, &clk_orphan_list
, child_node
)
1074 clk_unprepare_unused_subtree(core
);
1076 clk_prepare_unlock();
1080 late_initcall_sync(clk_disable_unused
);
1082 static int clk_core_determine_round_nolock(struct clk_core
*core
,
1083 struct clk_rate_request
*req
)
1087 lockdep_assert_held(&prepare_lock
);
1093 * At this point, core protection will be disabled if
1094 * - if the provider is not protected at all
1095 * - if the calling consumer is the only one which has exclusivity
1098 if (clk_core_rate_is_protected(core
)) {
1099 req
->rate
= core
->rate
;
1100 } else if (core
->ops
->determine_rate
) {
1101 return core
->ops
->determine_rate(core
->hw
, req
);
1102 } else if (core
->ops
->round_rate
) {
1103 rate
= core
->ops
->round_rate(core
->hw
, req
->rate
,
1104 &req
->best_parent_rate
);
1116 static void clk_core_init_rate_req(struct clk_core
* const core
,
1117 struct clk_rate_request
*req
)
1119 struct clk_core
*parent
;
1121 if (WARN_ON(!core
|| !req
))
1124 parent
= core
->parent
;
1126 req
->best_parent_hw
= parent
->hw
;
1127 req
->best_parent_rate
= parent
->rate
;
1129 req
->best_parent_hw
= NULL
;
1130 req
->best_parent_rate
= 0;
1134 static bool clk_core_can_round(struct clk_core
* const core
)
1136 if (core
->ops
->determine_rate
|| core
->ops
->round_rate
)
1142 static int clk_core_round_rate_nolock(struct clk_core
*core
,
1143 struct clk_rate_request
*req
)
1145 lockdep_assert_held(&prepare_lock
);
1152 clk_core_init_rate_req(core
, req
);
1154 if (clk_core_can_round(core
))
1155 return clk_core_determine_round_nolock(core
, req
);
1156 else if (core
->flags
& CLK_SET_RATE_PARENT
)
1157 return clk_core_round_rate_nolock(core
->parent
, req
);
1159 req
->rate
= core
->rate
;
1164 * __clk_determine_rate - get the closest rate actually supported by a clock
1165 * @hw: determine the rate of this clock
1166 * @req: target rate request
1168 * Useful for clk_ops such as .set_rate and .determine_rate.
1170 int __clk_determine_rate(struct clk_hw
*hw
, struct clk_rate_request
*req
)
1177 return clk_core_round_rate_nolock(hw
->core
, req
);
1179 EXPORT_SYMBOL_GPL(__clk_determine_rate
);
1181 unsigned long clk_hw_round_rate(struct clk_hw
*hw
, unsigned long rate
)
1184 struct clk_rate_request req
;
1186 clk_core_get_boundaries(hw
->core
, &req
.min_rate
, &req
.max_rate
);
1189 ret
= clk_core_round_rate_nolock(hw
->core
, &req
);
1195 EXPORT_SYMBOL_GPL(clk_hw_round_rate
);
1198 * clk_round_rate - round the given rate for a clk
1199 * @clk: the clk for which we are rounding a rate
1200 * @rate: the rate which is to be rounded
1202 * Takes in a rate as input and rounds it to a rate that the clk can actually
1203 * use which is then returned. If clk doesn't support round_rate operation
1204 * then the parent rate is returned.
1206 long clk_round_rate(struct clk
*clk
, unsigned long rate
)
1208 struct clk_rate_request req
;
1216 if (clk
->exclusive_count
)
1217 clk_core_rate_unprotect(clk
->core
);
1219 clk_core_get_boundaries(clk
->core
, &req
.min_rate
, &req
.max_rate
);
1222 ret
= clk_core_round_rate_nolock(clk
->core
, &req
);
1224 if (clk
->exclusive_count
)
1225 clk_core_rate_protect(clk
->core
);
1227 clk_prepare_unlock();
1234 EXPORT_SYMBOL_GPL(clk_round_rate
);
1237 * __clk_notify - call clk notifier chain
1238 * @core: clk that is changing rate
1239 * @msg: clk notifier type (see include/linux/clk.h)
1240 * @old_rate: old clk rate
1241 * @new_rate: new clk rate
1243 * Triggers a notifier call chain on the clk rate-change notification
1244 * for 'clk'. Passes a pointer to the struct clk and the previous
1245 * and current rates to the notifier callback. Intended to be called by
1246 * internal clock code only. Returns NOTIFY_DONE from the last driver
1247 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1248 * a driver returns that.
1250 static int __clk_notify(struct clk_core
*core
, unsigned long msg
,
1251 unsigned long old_rate
, unsigned long new_rate
)
1253 struct clk_notifier
*cn
;
1254 struct clk_notifier_data cnd
;
1255 int ret
= NOTIFY_DONE
;
1257 cnd
.old_rate
= old_rate
;
1258 cnd
.new_rate
= new_rate
;
1260 list_for_each_entry(cn
, &clk_notifier_list
, node
) {
1261 if (cn
->clk
->core
== core
) {
1263 ret
= srcu_notifier_call_chain(&cn
->notifier_head
, msg
,
1265 if (ret
& NOTIFY_STOP_MASK
)
1274 * __clk_recalc_accuracies
1275 * @core: first clk in the subtree
1277 * Walks the subtree of clks starting with clk and recalculates accuracies as
1278 * it goes. Note that if a clk does not implement the .recalc_accuracy
1279 * callback then it is assumed that the clock will take on the accuracy of its
1282 static void __clk_recalc_accuracies(struct clk_core
*core
)
1284 unsigned long parent_accuracy
= 0;
1285 struct clk_core
*child
;
1287 lockdep_assert_held(&prepare_lock
);
1290 parent_accuracy
= core
->parent
->accuracy
;
1292 if (core
->ops
->recalc_accuracy
)
1293 core
->accuracy
= core
->ops
->recalc_accuracy(core
->hw
,
1296 core
->accuracy
= parent_accuracy
;
1298 hlist_for_each_entry(child
, &core
->children
, child_node
)
1299 __clk_recalc_accuracies(child
);
1302 static long clk_core_get_accuracy(struct clk_core
*core
)
1304 unsigned long accuracy
;
1307 if (core
&& (core
->flags
& CLK_GET_ACCURACY_NOCACHE
))
1308 __clk_recalc_accuracies(core
);
1310 accuracy
= __clk_get_accuracy(core
);
1311 clk_prepare_unlock();
1317 * clk_get_accuracy - return the accuracy of clk
1318 * @clk: the clk whose accuracy is being returned
1320 * Simply returns the cached accuracy of the clk, unless
1321 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1323 * If clk is NULL then returns 0.
1325 long clk_get_accuracy(struct clk
*clk
)
1330 return clk_core_get_accuracy(clk
->core
);
1332 EXPORT_SYMBOL_GPL(clk_get_accuracy
);
1334 static unsigned long clk_recalc(struct clk_core
*core
,
1335 unsigned long parent_rate
)
1337 unsigned long rate
= parent_rate
;
1339 if (core
->ops
->recalc_rate
&& !clk_pm_runtime_get(core
)) {
1340 rate
= core
->ops
->recalc_rate(core
->hw
, parent_rate
);
1341 clk_pm_runtime_put(core
);
1347 * __clk_recalc_rates
1348 * @core: first clk in the subtree
1349 * @msg: notification type (see include/linux/clk.h)
1351 * Walks the subtree of clks starting with clk and recalculates rates as it
1352 * goes. Note that if a clk does not implement the .recalc_rate callback then
1353 * it is assumed that the clock will take on the rate of its parent.
1355 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1358 static void __clk_recalc_rates(struct clk_core
*core
, unsigned long msg
)
1360 unsigned long old_rate
;
1361 unsigned long parent_rate
= 0;
1362 struct clk_core
*child
;
1364 lockdep_assert_held(&prepare_lock
);
1366 old_rate
= core
->rate
;
1369 parent_rate
= core
->parent
->rate
;
1371 core
->rate
= clk_recalc(core
, parent_rate
);
1374 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1375 * & ABORT_RATE_CHANGE notifiers
1377 if (core
->notifier_count
&& msg
)
1378 __clk_notify(core
, msg
, old_rate
, core
->rate
);
1380 hlist_for_each_entry(child
, &core
->children
, child_node
)
1381 __clk_recalc_rates(child
, msg
);
1384 static unsigned long clk_core_get_rate(struct clk_core
*core
)
1390 if (core
&& (core
->flags
& CLK_GET_RATE_NOCACHE
))
1391 __clk_recalc_rates(core
, 0);
1393 rate
= clk_core_get_rate_nolock(core
);
1394 clk_prepare_unlock();
1400 * clk_get_rate - return the rate of clk
1401 * @clk: the clk whose rate is being returned
1403 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1404 * is set, which means a recalc_rate will be issued.
1405 * If clk is NULL then returns 0.
1407 unsigned long clk_get_rate(struct clk
*clk
)
1412 return clk_core_get_rate(clk
->core
);
1414 EXPORT_SYMBOL_GPL(clk_get_rate
);
1416 static int clk_fetch_parent_index(struct clk_core
*core
,
1417 struct clk_core
*parent
)
1424 for (i
= 0; i
< core
->num_parents
; i
++)
1425 if (clk_core_get_parent_by_index(core
, i
) == parent
)
1432 * Update the orphan status of @core and all its children.
1434 static void clk_core_update_orphan_status(struct clk_core
*core
, bool is_orphan
)
1436 struct clk_core
*child
;
1438 core
->orphan
= is_orphan
;
1440 hlist_for_each_entry(child
, &core
->children
, child_node
)
1441 clk_core_update_orphan_status(child
, is_orphan
);
1444 static void clk_reparent(struct clk_core
*core
, struct clk_core
*new_parent
)
1446 bool was_orphan
= core
->orphan
;
1448 hlist_del(&core
->child_node
);
1451 bool becomes_orphan
= new_parent
->orphan
;
1453 /* avoid duplicate POST_RATE_CHANGE notifications */
1454 if (new_parent
->new_child
== core
)
1455 new_parent
->new_child
= NULL
;
1457 hlist_add_head(&core
->child_node
, &new_parent
->children
);
1459 if (was_orphan
!= becomes_orphan
)
1460 clk_core_update_orphan_status(core
, becomes_orphan
);
1462 hlist_add_head(&core
->child_node
, &clk_orphan_list
);
1464 clk_core_update_orphan_status(core
, true);
1467 core
->parent
= new_parent
;
1470 static struct clk_core
*__clk_set_parent_before(struct clk_core
*core
,
1471 struct clk_core
*parent
)
1473 unsigned long flags
;
1474 struct clk_core
*old_parent
= core
->parent
;
1477 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
1479 * 2. Migrate prepare state between parents and prevent race with
1482 * If the clock is not prepared, then a race with
1483 * clk_enable/disable() is impossible since we already have the
1484 * prepare lock (future calls to clk_enable() need to be preceded by
1487 * If the clock is prepared, migrate the prepared state to the new
1488 * parent and also protect against a race with clk_enable() by
1489 * forcing the clock and the new parent on. This ensures that all
1490 * future calls to clk_enable() are practically NOPs with respect to
1491 * hardware and software states.
1493 * See also: Comment for clk_set_parent() below.
1496 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
1497 if (core
->flags
& CLK_OPS_PARENT_ENABLE
) {
1498 clk_core_prepare_enable(old_parent
);
1499 clk_core_prepare_enable(parent
);
1502 /* migrate prepare count if > 0 */
1503 if (core
->prepare_count
) {
1504 clk_core_prepare_enable(parent
);
1505 clk_core_enable_lock(core
);
1508 /* update the clk tree topology */
1509 flags
= clk_enable_lock();
1510 clk_reparent(core
, parent
);
1511 clk_enable_unlock(flags
);
1516 static void __clk_set_parent_after(struct clk_core
*core
,
1517 struct clk_core
*parent
,
1518 struct clk_core
*old_parent
)
1521 * Finish the migration of prepare state and undo the changes done
1522 * for preventing a race with clk_enable().
1524 if (core
->prepare_count
) {
1525 clk_core_disable_lock(core
);
1526 clk_core_disable_unprepare(old_parent
);
1529 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
1530 if (core
->flags
& CLK_OPS_PARENT_ENABLE
) {
1531 clk_core_disable_unprepare(parent
);
1532 clk_core_disable_unprepare(old_parent
);
1536 static int __clk_set_parent(struct clk_core
*core
, struct clk_core
*parent
,
1539 unsigned long flags
;
1541 struct clk_core
*old_parent
;
1543 old_parent
= __clk_set_parent_before(core
, parent
);
1545 trace_clk_set_parent(core
, parent
);
1547 /* change clock input source */
1548 if (parent
&& core
->ops
->set_parent
)
1549 ret
= core
->ops
->set_parent(core
->hw
, p_index
);
1551 trace_clk_set_parent_complete(core
, parent
);
1554 flags
= clk_enable_lock();
1555 clk_reparent(core
, old_parent
);
1556 clk_enable_unlock(flags
);
1557 __clk_set_parent_after(core
, old_parent
, parent
);
1562 __clk_set_parent_after(core
, parent
, old_parent
);
1568 * __clk_speculate_rates
1569 * @core: first clk in the subtree
1570 * @parent_rate: the "future" rate of clk's parent
1572 * Walks the subtree of clks starting with clk, speculating rates as it
1573 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1575 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1576 * pre-rate change notifications and returns early if no clks in the
1577 * subtree have subscribed to the notifications. Note that if a clk does not
1578 * implement the .recalc_rate callback then it is assumed that the clock will
1579 * take on the rate of its parent.
1581 static int __clk_speculate_rates(struct clk_core
*core
,
1582 unsigned long parent_rate
)
1584 struct clk_core
*child
;
1585 unsigned long new_rate
;
1586 int ret
= NOTIFY_DONE
;
1588 lockdep_assert_held(&prepare_lock
);
1590 new_rate
= clk_recalc(core
, parent_rate
);
1592 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1593 if (core
->notifier_count
)
1594 ret
= __clk_notify(core
, PRE_RATE_CHANGE
, core
->rate
, new_rate
);
1596 if (ret
& NOTIFY_STOP_MASK
) {
1597 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1598 __func__
, core
->name
, ret
);
1602 hlist_for_each_entry(child
, &core
->children
, child_node
) {
1603 ret
= __clk_speculate_rates(child
, new_rate
);
1604 if (ret
& NOTIFY_STOP_MASK
)
1612 static void clk_calc_subtree(struct clk_core
*core
, unsigned long new_rate
,
1613 struct clk_core
*new_parent
, u8 p_index
)
1615 struct clk_core
*child
;
1617 core
->new_rate
= new_rate
;
1618 core
->new_parent
= new_parent
;
1619 core
->new_parent_index
= p_index
;
1620 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1621 core
->new_child
= NULL
;
1622 if (new_parent
&& new_parent
!= core
->parent
)
1623 new_parent
->new_child
= core
;
1625 hlist_for_each_entry(child
, &core
->children
, child_node
) {
1626 child
->new_rate
= clk_recalc(child
, new_rate
);
1627 clk_calc_subtree(child
, child
->new_rate
, NULL
, 0);
1632 * calculate the new rates returning the topmost clock that has to be
1635 static struct clk_core
*clk_calc_new_rates(struct clk_core
*core
,
1638 struct clk_core
*top
= core
;
1639 struct clk_core
*old_parent
, *parent
;
1640 unsigned long best_parent_rate
= 0;
1641 unsigned long new_rate
;
1642 unsigned long min_rate
;
1643 unsigned long max_rate
;
1648 if (IS_ERR_OR_NULL(core
))
1651 /* save parent rate, if it exists */
1652 parent
= old_parent
= core
->parent
;
1654 best_parent_rate
= parent
->rate
;
1656 clk_core_get_boundaries(core
, &min_rate
, &max_rate
);
1658 /* find the closest rate and parent clk/rate */
1659 if (clk_core_can_round(core
)) {
1660 struct clk_rate_request req
;
1663 req
.min_rate
= min_rate
;
1664 req
.max_rate
= max_rate
;
1666 clk_core_init_rate_req(core
, &req
);
1668 ret
= clk_core_determine_round_nolock(core
, &req
);
1672 best_parent_rate
= req
.best_parent_rate
;
1673 new_rate
= req
.rate
;
1674 parent
= req
.best_parent_hw
? req
.best_parent_hw
->core
: NULL
;
1676 if (new_rate
< min_rate
|| new_rate
> max_rate
)
1678 } else if (!parent
|| !(core
->flags
& CLK_SET_RATE_PARENT
)) {
1679 /* pass-through clock without adjustable parent */
1680 core
->new_rate
= core
->rate
;
1683 /* pass-through clock with adjustable parent */
1684 top
= clk_calc_new_rates(parent
, rate
);
1685 new_rate
= parent
->new_rate
;
1689 /* some clocks must be gated to change parent */
1690 if (parent
!= old_parent
&&
1691 (core
->flags
& CLK_SET_PARENT_GATE
) && core
->prepare_count
) {
1692 pr_debug("%s: %s not gated but wants to reparent\n",
1693 __func__
, core
->name
);
1697 /* try finding the new parent index */
1698 if (parent
&& core
->num_parents
> 1) {
1699 p_index
= clk_fetch_parent_index(core
, parent
);
1701 pr_debug("%s: clk %s can not be parent of clk %s\n",
1702 __func__
, parent
->name
, core
->name
);
1707 if ((core
->flags
& CLK_SET_RATE_PARENT
) && parent
&&
1708 best_parent_rate
!= parent
->rate
)
1709 top
= clk_calc_new_rates(parent
, best_parent_rate
);
1712 clk_calc_subtree(core
, new_rate
, parent
, p_index
);
1718 * Notify about rate changes in a subtree. Always walk down the whole tree
1719 * so that in case of an error we can walk down the whole tree again and
1722 static struct clk_core
*clk_propagate_rate_change(struct clk_core
*core
,
1723 unsigned long event
)
1725 struct clk_core
*child
, *tmp_clk
, *fail_clk
= NULL
;
1726 int ret
= NOTIFY_DONE
;
1728 if (core
->rate
== core
->new_rate
)
1731 if (core
->notifier_count
) {
1732 ret
= __clk_notify(core
, event
, core
->rate
, core
->new_rate
);
1733 if (ret
& NOTIFY_STOP_MASK
)
1737 hlist_for_each_entry(child
, &core
->children
, child_node
) {
1738 /* Skip children who will be reparented to another clock */
1739 if (child
->new_parent
&& child
->new_parent
!= core
)
1741 tmp_clk
= clk_propagate_rate_change(child
, event
);
1746 /* handle the new child who might not be in core->children yet */
1747 if (core
->new_child
) {
1748 tmp_clk
= clk_propagate_rate_change(core
->new_child
, event
);
1757 * walk down a subtree and set the new rates notifying the rate
1760 static void clk_change_rate(struct clk_core
*core
)
1762 struct clk_core
*child
;
1763 struct hlist_node
*tmp
;
1764 unsigned long old_rate
;
1765 unsigned long best_parent_rate
= 0;
1766 bool skip_set_rate
= false;
1767 struct clk_core
*old_parent
;
1768 struct clk_core
*parent
= NULL
;
1770 old_rate
= core
->rate
;
1772 if (core
->new_parent
) {
1773 parent
= core
->new_parent
;
1774 best_parent_rate
= core
->new_parent
->rate
;
1775 } else if (core
->parent
) {
1776 parent
= core
->parent
;
1777 best_parent_rate
= core
->parent
->rate
;
1780 if (clk_pm_runtime_get(core
))
1783 if (core
->flags
& CLK_SET_RATE_UNGATE
) {
1784 unsigned long flags
;
1786 clk_core_prepare(core
);
1787 flags
= clk_enable_lock();
1788 clk_core_enable(core
);
1789 clk_enable_unlock(flags
);
1792 if (core
->new_parent
&& core
->new_parent
!= core
->parent
) {
1793 old_parent
= __clk_set_parent_before(core
, core
->new_parent
);
1794 trace_clk_set_parent(core
, core
->new_parent
);
1796 if (core
->ops
->set_rate_and_parent
) {
1797 skip_set_rate
= true;
1798 core
->ops
->set_rate_and_parent(core
->hw
, core
->new_rate
,
1800 core
->new_parent_index
);
1801 } else if (core
->ops
->set_parent
) {
1802 core
->ops
->set_parent(core
->hw
, core
->new_parent_index
);
1805 trace_clk_set_parent_complete(core
, core
->new_parent
);
1806 __clk_set_parent_after(core
, core
->new_parent
, old_parent
);
1809 if (core
->flags
& CLK_OPS_PARENT_ENABLE
)
1810 clk_core_prepare_enable(parent
);
1812 trace_clk_set_rate(core
, core
->new_rate
);
1814 if (!skip_set_rate
&& core
->ops
->set_rate
)
1815 core
->ops
->set_rate(core
->hw
, core
->new_rate
, best_parent_rate
);
1817 trace_clk_set_rate_complete(core
, core
->new_rate
);
1819 core
->rate
= clk_recalc(core
, best_parent_rate
);
1821 if (core
->flags
& CLK_SET_RATE_UNGATE
) {
1822 unsigned long flags
;
1824 flags
= clk_enable_lock();
1825 clk_core_disable(core
);
1826 clk_enable_unlock(flags
);
1827 clk_core_unprepare(core
);
1830 if (core
->flags
& CLK_OPS_PARENT_ENABLE
)
1831 clk_core_disable_unprepare(parent
);
1833 if (core
->notifier_count
&& old_rate
!= core
->rate
)
1834 __clk_notify(core
, POST_RATE_CHANGE
, old_rate
, core
->rate
);
1836 if (core
->flags
& CLK_RECALC_NEW_RATES
)
1837 (void)clk_calc_new_rates(core
, core
->new_rate
);
1840 * Use safe iteration, as change_rate can actually swap parents
1841 * for certain clock types.
1843 hlist_for_each_entry_safe(child
, tmp
, &core
->children
, child_node
) {
1844 /* Skip children who will be reparented to another clock */
1845 if (child
->new_parent
&& child
->new_parent
!= core
)
1847 clk_change_rate(child
);
1850 /* handle the new child who might not be in core->children yet */
1851 if (core
->new_child
)
1852 clk_change_rate(core
->new_child
);
1854 clk_pm_runtime_put(core
);
1857 static unsigned long clk_core_req_round_rate_nolock(struct clk_core
*core
,
1858 unsigned long req_rate
)
1861 struct clk_rate_request req
;
1863 lockdep_assert_held(&prepare_lock
);
1868 /* simulate what the rate would be if it could be freely set */
1869 cnt
= clk_core_rate_nuke_protect(core
);
1873 clk_core_get_boundaries(core
, &req
.min_rate
, &req
.max_rate
);
1874 req
.rate
= req_rate
;
1876 ret
= clk_core_round_rate_nolock(core
, &req
);
1878 /* restore the protection */
1879 clk_core_rate_restore_protect(core
, cnt
);
1881 return ret
? 0 : req
.rate
;
1884 static int clk_core_set_rate_nolock(struct clk_core
*core
,
1885 unsigned long req_rate
)
1887 struct clk_core
*top
, *fail_clk
;
1894 rate
= clk_core_req_round_rate_nolock(core
, req_rate
);
1896 /* bail early if nothing to do */
1897 if (rate
== clk_core_get_rate_nolock(core
))
1900 /* fail on a direct rate set of a protected provider */
1901 if (clk_core_rate_is_protected(core
))
1904 /* calculate new rates and get the topmost changed clock */
1905 top
= clk_calc_new_rates(core
, req_rate
);
1909 ret
= clk_pm_runtime_get(core
);
1913 /* notify that we are about to change rates */
1914 fail_clk
= clk_propagate_rate_change(top
, PRE_RATE_CHANGE
);
1916 pr_debug("%s: failed to set %s rate\n", __func__
,
1918 clk_propagate_rate_change(top
, ABORT_RATE_CHANGE
);
1923 /* change the rates */
1924 clk_change_rate(top
);
1926 core
->req_rate
= req_rate
;
1928 clk_pm_runtime_put(core
);
1934 * clk_set_rate - specify a new rate for clk
1935 * @clk: the clk whose rate is being changed
1936 * @rate: the new rate for clk
1938 * In the simplest case clk_set_rate will only adjust the rate of clk.
1940 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1941 * propagate up to clk's parent; whether or not this happens depends on the
1942 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1943 * after calling .round_rate then upstream parent propagation is ignored. If
1944 * *parent_rate comes back with a new rate for clk's parent then we propagate
1945 * up to clk's parent and set its rate. Upward propagation will continue
1946 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1947 * .round_rate stops requesting changes to clk's parent_rate.
1949 * Rate changes are accomplished via tree traversal that also recalculates the
1950 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
1952 * Returns 0 on success, -EERROR otherwise.
1954 int clk_set_rate(struct clk
*clk
, unsigned long rate
)
1961 /* prevent racing with updates to the clock topology */
1964 if (clk
->exclusive_count
)
1965 clk_core_rate_unprotect(clk
->core
);
1967 ret
= clk_core_set_rate_nolock(clk
->core
, rate
);
1969 if (clk
->exclusive_count
)
1970 clk_core_rate_protect(clk
->core
);
1972 clk_prepare_unlock();
1976 EXPORT_SYMBOL_GPL(clk_set_rate
);
1979 * clk_set_rate_exclusive - specify a new rate get exclusive control
1980 * @clk: the clk whose rate is being changed
1981 * @rate: the new rate for clk
1983 * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
1984 * within a critical section
1986 * This can be used initially to ensure that at least 1 consumer is
1987 * statisfied when several consumers are competing for exclusivity over the
1988 * same clock provider.
1990 * The exclusivity is not applied if setting the rate failed.
1992 * Calls to clk_rate_exclusive_get() should be balanced with calls to
1993 * clk_rate_exclusive_put().
1995 * Returns 0 on success, -EERROR otherwise.
1997 int clk_set_rate_exclusive(struct clk
*clk
, unsigned long rate
)
2004 /* prevent racing with updates to the clock topology */
2008 * The temporary protection removal is not here, on purpose
2009 * This function is meant to be used instead of clk_rate_protect,
2010 * so before the consumer code path protect the clock provider
2013 ret
= clk_core_set_rate_nolock(clk
->core
, rate
);
2015 clk_core_rate_protect(clk
->core
);
2016 clk
->exclusive_count
++;
2019 clk_prepare_unlock();
2023 EXPORT_SYMBOL_GPL(clk_set_rate_exclusive
);
2026 * clk_set_rate_range - set a rate range for a clock source
2027 * @clk: clock source
2028 * @min: desired minimum clock rate in Hz, inclusive
2029 * @max: desired maximum clock rate in Hz, inclusive
2031 * Returns success (0) or negative errno.
2033 int clk_set_rate_range(struct clk
*clk
, unsigned long min
, unsigned long max
)
2036 unsigned long old_min
, old_max
, rate
;
2042 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
2043 __func__
, clk
->core
->name
, clk
->dev_id
, clk
->con_id
,
2050 if (clk
->exclusive_count
)
2051 clk_core_rate_unprotect(clk
->core
);
2053 /* Save the current values in case we need to rollback the change */
2054 old_min
= clk
->min_rate
;
2055 old_max
= clk
->max_rate
;
2056 clk
->min_rate
= min
;
2057 clk
->max_rate
= max
;
2059 rate
= clk_core_get_rate_nolock(clk
->core
);
2060 if (rate
< min
|| rate
> max
) {
2063 * We are in bit of trouble here, current rate is outside the
2064 * the requested range. We are going try to request appropriate
2065 * range boundary but there is a catch. It may fail for the
2066 * usual reason (clock broken, clock protected, etc) but also
2068 * - round_rate() was not favorable and fell on the wrong
2069 * side of the boundary
2070 * - the determine_rate() callback does not really check for
2071 * this corner case when determining the rate
2079 ret
= clk_core_set_rate_nolock(clk
->core
, rate
);
2081 /* rollback the changes */
2082 clk
->min_rate
= old_min
;
2083 clk
->max_rate
= old_max
;
2087 if (clk
->exclusive_count
)
2088 clk_core_rate_protect(clk
->core
);
2090 clk_prepare_unlock();
2094 EXPORT_SYMBOL_GPL(clk_set_rate_range
);
2097 * clk_set_min_rate - set a minimum clock rate for a clock source
2098 * @clk: clock source
2099 * @rate: desired minimum clock rate in Hz, inclusive
2101 * Returns success (0) or negative errno.
2103 int clk_set_min_rate(struct clk
*clk
, unsigned long rate
)
2108 return clk_set_rate_range(clk
, rate
, clk
->max_rate
);
2110 EXPORT_SYMBOL_GPL(clk_set_min_rate
);
2113 * clk_set_max_rate - set a maximum clock rate for a clock source
2114 * @clk: clock source
2115 * @rate: desired maximum clock rate in Hz, inclusive
2117 * Returns success (0) or negative errno.
2119 int clk_set_max_rate(struct clk
*clk
, unsigned long rate
)
2124 return clk_set_rate_range(clk
, clk
->min_rate
, rate
);
2126 EXPORT_SYMBOL_GPL(clk_set_max_rate
);
2129 * clk_get_parent - return the parent of a clk
2130 * @clk: the clk whose parent gets returned
2132 * Simply returns clk->parent. Returns NULL if clk is NULL.
2134 struct clk
*clk_get_parent(struct clk
*clk
)
2142 /* TODO: Create a per-user clk and change callers to call clk_put */
2143 parent
= !clk
->core
->parent
? NULL
: clk
->core
->parent
->hw
->clk
;
2144 clk_prepare_unlock();
2148 EXPORT_SYMBOL_GPL(clk_get_parent
);
2150 static struct clk_core
*__clk_init_parent(struct clk_core
*core
)
2154 if (core
->num_parents
> 1 && core
->ops
->get_parent
)
2155 index
= core
->ops
->get_parent(core
->hw
);
2157 return clk_core_get_parent_by_index(core
, index
);
2160 static void clk_core_reparent(struct clk_core
*core
,
2161 struct clk_core
*new_parent
)
2163 clk_reparent(core
, new_parent
);
2164 __clk_recalc_accuracies(core
);
2165 __clk_recalc_rates(core
, POST_RATE_CHANGE
);
2168 void clk_hw_reparent(struct clk_hw
*hw
, struct clk_hw
*new_parent
)
2173 clk_core_reparent(hw
->core
, !new_parent
? NULL
: new_parent
->core
);
2177 * clk_has_parent - check if a clock is a possible parent for another
2178 * @clk: clock source
2179 * @parent: parent clock source
2181 * This function can be used in drivers that need to check that a clock can be
2182 * the parent of another without actually changing the parent.
2184 * Returns true if @parent is a possible parent for @clk, false otherwise.
2186 bool clk_has_parent(struct clk
*clk
, struct clk
*parent
)
2188 struct clk_core
*core
, *parent_core
;
2190 /* NULL clocks should be nops, so return success if either is NULL. */
2191 if (!clk
|| !parent
)
2195 parent_core
= parent
->core
;
2197 /* Optimize for the case where the parent is already the parent. */
2198 if (core
->parent
== parent_core
)
2201 return match_string(core
->parent_names
, core
->num_parents
,
2202 parent_core
->name
) >= 0;
2204 EXPORT_SYMBOL_GPL(clk_has_parent
);
2206 static int clk_core_set_parent_nolock(struct clk_core
*core
,
2207 struct clk_core
*parent
)
2211 unsigned long p_rate
= 0;
2213 lockdep_assert_held(&prepare_lock
);
2218 if (core
->parent
== parent
)
2221 /* verify ops for for multi-parent clks */
2222 if (core
->num_parents
> 1 && !core
->ops
->set_parent
)
2225 /* check that we are allowed to re-parent if the clock is in use */
2226 if ((core
->flags
& CLK_SET_PARENT_GATE
) && core
->prepare_count
)
2229 if (clk_core_rate_is_protected(core
))
2232 /* try finding the new parent index */
2234 p_index
= clk_fetch_parent_index(core
, parent
);
2236 pr_debug("%s: clk %s can not be parent of clk %s\n",
2237 __func__
, parent
->name
, core
->name
);
2240 p_rate
= parent
->rate
;
2243 ret
= clk_pm_runtime_get(core
);
2247 /* propagate PRE_RATE_CHANGE notifications */
2248 ret
= __clk_speculate_rates(core
, p_rate
);
2250 /* abort if a driver objects */
2251 if (ret
& NOTIFY_STOP_MASK
)
2254 /* do the re-parent */
2255 ret
= __clk_set_parent(core
, parent
, p_index
);
2257 /* propagate rate an accuracy recalculation accordingly */
2259 __clk_recalc_rates(core
, ABORT_RATE_CHANGE
);
2261 __clk_recalc_rates(core
, POST_RATE_CHANGE
);
2262 __clk_recalc_accuracies(core
);
2266 clk_pm_runtime_put(core
);
2272 * clk_set_parent - switch the parent of a mux clk
2273 * @clk: the mux clk whose input we are switching
2274 * @parent: the new input to clk
2276 * Re-parent clk to use parent as its new input source. If clk is in
2277 * prepared state, the clk will get enabled for the duration of this call. If
2278 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2279 * that, the reparenting is glitchy in hardware, etc), use the
2280 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2282 * After successfully changing clk's parent clk_set_parent will update the
2283 * clk topology, sysfs topology and propagate rate recalculation via
2284 * __clk_recalc_rates.
2286 * Returns 0 on success, -EERROR otherwise.
2288 int clk_set_parent(struct clk
*clk
, struct clk
*parent
)
2297 if (clk
->exclusive_count
)
2298 clk_core_rate_unprotect(clk
->core
);
2300 ret
= clk_core_set_parent_nolock(clk
->core
,
2301 parent
? parent
->core
: NULL
);
2303 if (clk
->exclusive_count
)
2304 clk_core_rate_protect(clk
->core
);
2306 clk_prepare_unlock();
2310 EXPORT_SYMBOL_GPL(clk_set_parent
);
2312 static int clk_core_set_phase_nolock(struct clk_core
*core
, int degrees
)
2316 lockdep_assert_held(&prepare_lock
);
2321 if (clk_core_rate_is_protected(core
))
2324 trace_clk_set_phase(core
, degrees
);
2326 if (core
->ops
->set_phase
) {
2327 ret
= core
->ops
->set_phase(core
->hw
, degrees
);
2329 core
->phase
= degrees
;
2332 trace_clk_set_phase_complete(core
, degrees
);
2338 * clk_set_phase - adjust the phase shift of a clock signal
2339 * @clk: clock signal source
2340 * @degrees: number of degrees the signal is shifted
2342 * Shifts the phase of a clock signal by the specified
2343 * degrees. Returns 0 on success, -EERROR otherwise.
2345 * This function makes no distinction about the input or reference
2346 * signal that we adjust the clock signal phase against. For example
2347 * phase locked-loop clock signal generators we may shift phase with
2348 * respect to feedback clock signal input, but for other cases the
2349 * clock phase may be shifted with respect to some other, unspecified
2352 * Additionally the concept of phase shift does not propagate through
2353 * the clock tree hierarchy, which sets it apart from clock rates and
2354 * clock accuracy. A parent clock phase attribute does not have an
2355 * impact on the phase attribute of a child clock.
2357 int clk_set_phase(struct clk
*clk
, int degrees
)
2364 /* sanity check degrees */
2371 if (clk
->exclusive_count
)
2372 clk_core_rate_unprotect(clk
->core
);
2374 ret
= clk_core_set_phase_nolock(clk
->core
, degrees
);
2376 if (clk
->exclusive_count
)
2377 clk_core_rate_protect(clk
->core
);
2379 clk_prepare_unlock();
2383 EXPORT_SYMBOL_GPL(clk_set_phase
);
2385 static int clk_core_get_phase(struct clk_core
*core
)
2390 /* Always try to update cached phase if possible */
2391 if (core
->ops
->get_phase
)
2392 core
->phase
= core
->ops
->get_phase(core
->hw
);
2394 clk_prepare_unlock();
2400 * clk_get_phase - return the phase shift of a clock signal
2401 * @clk: clock signal source
2403 * Returns the phase shift of a clock node in degrees, otherwise returns
2406 int clk_get_phase(struct clk
*clk
)
2411 return clk_core_get_phase(clk
->core
);
2413 EXPORT_SYMBOL_GPL(clk_get_phase
);
2415 static void clk_core_reset_duty_cycle_nolock(struct clk_core
*core
)
2417 /* Assume a default value of 50% */
2422 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core
*core
);
2424 static int clk_core_update_duty_cycle_nolock(struct clk_core
*core
)
2426 struct clk_duty
*duty
= &core
->duty
;
2429 if (!core
->ops
->get_duty_cycle
)
2430 return clk_core_update_duty_cycle_parent_nolock(core
);
2432 ret
= core
->ops
->get_duty_cycle(core
->hw
, duty
);
2436 /* Don't trust the clock provider too much */
2437 if (duty
->den
== 0 || duty
->num
> duty
->den
) {
2445 clk_core_reset_duty_cycle_nolock(core
);
2449 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core
*core
)
2454 core
->flags
& CLK_DUTY_CYCLE_PARENT
) {
2455 ret
= clk_core_update_duty_cycle_nolock(core
->parent
);
2456 memcpy(&core
->duty
, &core
->parent
->duty
, sizeof(core
->duty
));
2458 clk_core_reset_duty_cycle_nolock(core
);
2464 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core
*core
,
2465 struct clk_duty
*duty
);
2467 static int clk_core_set_duty_cycle_nolock(struct clk_core
*core
,
2468 struct clk_duty
*duty
)
2472 lockdep_assert_held(&prepare_lock
);
2474 if (clk_core_rate_is_protected(core
))
2477 trace_clk_set_duty_cycle(core
, duty
);
2479 if (!core
->ops
->set_duty_cycle
)
2480 return clk_core_set_duty_cycle_parent_nolock(core
, duty
);
2482 ret
= core
->ops
->set_duty_cycle(core
->hw
, duty
);
2484 memcpy(&core
->duty
, duty
, sizeof(*duty
));
2486 trace_clk_set_duty_cycle_complete(core
, duty
);
2491 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core
*core
,
2492 struct clk_duty
*duty
)
2497 core
->flags
& (CLK_DUTY_CYCLE_PARENT
| CLK_SET_RATE_PARENT
)) {
2498 ret
= clk_core_set_duty_cycle_nolock(core
->parent
, duty
);
2499 memcpy(&core
->duty
, &core
->parent
->duty
, sizeof(core
->duty
));
2506 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
2507 * @clk: clock signal source
2508 * @num: numerator of the duty cycle ratio to be applied
2509 * @den: denominator of the duty cycle ratio to be applied
2511 * Apply the duty cycle ratio if the ratio is valid and the clock can
2512 * perform this operation
2514 * Returns (0) on success, a negative errno otherwise.
2516 int clk_set_duty_cycle(struct clk
*clk
, unsigned int num
, unsigned int den
)
2519 struct clk_duty duty
;
2524 /* sanity check the ratio */
2525 if (den
== 0 || num
> den
)
2533 if (clk
->exclusive_count
)
2534 clk_core_rate_unprotect(clk
->core
);
2536 ret
= clk_core_set_duty_cycle_nolock(clk
->core
, &duty
);
2538 if (clk
->exclusive_count
)
2539 clk_core_rate_protect(clk
->core
);
2541 clk_prepare_unlock();
2545 EXPORT_SYMBOL_GPL(clk_set_duty_cycle
);
2547 static int clk_core_get_scaled_duty_cycle(struct clk_core
*core
,
2550 struct clk_duty
*duty
= &core
->duty
;
2555 ret
= clk_core_update_duty_cycle_nolock(core
);
2557 ret
= mult_frac(scale
, duty
->num
, duty
->den
);
2559 clk_prepare_unlock();
2565 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
2566 * @clk: clock signal source
2567 * @scale: scaling factor to be applied to represent the ratio as an integer
2569 * Returns the duty cycle ratio of a clock node multiplied by the provided
2570 * scaling factor, or negative errno on error.
2572 int clk_get_scaled_duty_cycle(struct clk
*clk
, unsigned int scale
)
2577 return clk_core_get_scaled_duty_cycle(clk
->core
, scale
);
2579 EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle
);
2582 * clk_is_match - check if two clk's point to the same hardware clock
2583 * @p: clk compared against q
2584 * @q: clk compared against p
2586 * Returns true if the two struct clk pointers both point to the same hardware
2587 * clock node. Put differently, returns true if struct clk *p and struct clk *q
2588 * share the same struct clk_core object.
2590 * Returns false otherwise. Note that two NULL clks are treated as matching.
2592 bool clk_is_match(const struct clk
*p
, const struct clk
*q
)
2594 /* trivial case: identical struct clk's or both NULL */
2598 /* true if clk->core pointers match. Avoid dereferencing garbage */
2599 if (!IS_ERR_OR_NULL(p
) && !IS_ERR_OR_NULL(q
))
2600 if (p
->core
== q
->core
)
2605 EXPORT_SYMBOL_GPL(clk_is_match
);
2607 /*** debugfs support ***/
2609 #ifdef CONFIG_DEBUG_FS
2610 #include <linux/debugfs.h>
2612 static struct dentry
*rootdir
;
2613 static int inited
= 0;
2614 static DEFINE_MUTEX(clk_debug_lock
);
2615 static HLIST_HEAD(clk_debug_list
);
2617 static struct hlist_head
*all_lists
[] = {
2623 static struct hlist_head
*orphan_list
[] = {
2628 static void clk_summary_show_one(struct seq_file
*s
, struct clk_core
*c
,
2634 seq_printf(s
, "%*s%-*s %7d %8d %8d %11lu %10lu %5d %6d\n",
2636 30 - level
* 3, c
->name
,
2637 c
->enable_count
, c
->prepare_count
, c
->protect_count
,
2638 clk_core_get_rate(c
), clk_core_get_accuracy(c
),
2639 clk_core_get_phase(c
),
2640 clk_core_get_scaled_duty_cycle(c
, 100000));
2643 static void clk_summary_show_subtree(struct seq_file
*s
, struct clk_core
*c
,
2646 struct clk_core
*child
;
2651 clk_summary_show_one(s
, c
, level
);
2653 hlist_for_each_entry(child
, &c
->children
, child_node
)
2654 clk_summary_show_subtree(s
, child
, level
+ 1);
2657 static int clk_summary_show(struct seq_file
*s
, void *data
)
2660 struct hlist_head
**lists
= (struct hlist_head
**)s
->private;
2662 seq_puts(s
, " enable prepare protect duty\n");
2663 seq_puts(s
, " clock count count count rate accuracy phase cycle\n");
2664 seq_puts(s
, "---------------------------------------------------------------------------------------------\n");
2668 for (; *lists
; lists
++)
2669 hlist_for_each_entry(c
, *lists
, child_node
)
2670 clk_summary_show_subtree(s
, c
, 0);
2672 clk_prepare_unlock();
2676 DEFINE_SHOW_ATTRIBUTE(clk_summary
);
2678 static void clk_dump_one(struct seq_file
*s
, struct clk_core
*c
, int level
)
2683 /* This should be JSON format, i.e. elements separated with a comma */
2684 seq_printf(s
, "\"%s\": { ", c
->name
);
2685 seq_printf(s
, "\"enable_count\": %d,", c
->enable_count
);
2686 seq_printf(s
, "\"prepare_count\": %d,", c
->prepare_count
);
2687 seq_printf(s
, "\"protect_count\": %d,", c
->protect_count
);
2688 seq_printf(s
, "\"rate\": %lu,", clk_core_get_rate(c
));
2689 seq_printf(s
, "\"accuracy\": %lu,", clk_core_get_accuracy(c
));
2690 seq_printf(s
, "\"phase\": %d", clk_core_get_phase(c
));
2691 seq_printf(s
, "\"duty_cycle\": %u",
2692 clk_core_get_scaled_duty_cycle(c
, 100000));
2695 static void clk_dump_subtree(struct seq_file
*s
, struct clk_core
*c
, int level
)
2697 struct clk_core
*child
;
2702 clk_dump_one(s
, c
, level
);
2704 hlist_for_each_entry(child
, &c
->children
, child_node
) {
2706 clk_dump_subtree(s
, child
, level
+ 1);
2712 static int clk_dump_show(struct seq_file
*s
, void *data
)
2715 bool first_node
= true;
2716 struct hlist_head
**lists
= (struct hlist_head
**)s
->private;
2721 for (; *lists
; lists
++) {
2722 hlist_for_each_entry(c
, *lists
, child_node
) {
2726 clk_dump_subtree(s
, c
, 0);
2730 clk_prepare_unlock();
2735 DEFINE_SHOW_ATTRIBUTE(clk_dump
);
2737 static const struct {
2741 #define ENTRY(f) { f, #f }
2742 ENTRY(CLK_SET_RATE_GATE
),
2743 ENTRY(CLK_SET_PARENT_GATE
),
2744 ENTRY(CLK_SET_RATE_PARENT
),
2745 ENTRY(CLK_IGNORE_UNUSED
),
2746 ENTRY(CLK_IS_BASIC
),
2747 ENTRY(CLK_GET_RATE_NOCACHE
),
2748 ENTRY(CLK_SET_RATE_NO_REPARENT
),
2749 ENTRY(CLK_GET_ACCURACY_NOCACHE
),
2750 ENTRY(CLK_RECALC_NEW_RATES
),
2751 ENTRY(CLK_SET_RATE_UNGATE
),
2752 ENTRY(CLK_IS_CRITICAL
),
2753 ENTRY(CLK_OPS_PARENT_ENABLE
),
2754 ENTRY(CLK_DUTY_CYCLE_PARENT
),
2758 static int clk_flags_show(struct seq_file
*s
, void *data
)
2760 struct clk_core
*core
= s
->private;
2761 unsigned long flags
= core
->flags
;
2764 for (i
= 0; flags
&& i
< ARRAY_SIZE(clk_flags
); i
++) {
2765 if (flags
& clk_flags
[i
].flag
) {
2766 seq_printf(s
, "%s\n", clk_flags
[i
].name
);
2767 flags
&= ~clk_flags
[i
].flag
;
2772 seq_printf(s
, "0x%lx\n", flags
);
2777 DEFINE_SHOW_ATTRIBUTE(clk_flags
);
2779 static int possible_parents_show(struct seq_file
*s
, void *data
)
2781 struct clk_core
*core
= s
->private;
2784 for (i
= 0; i
< core
->num_parents
- 1; i
++)
2785 seq_printf(s
, "%s ", core
->parent_names
[i
]);
2787 seq_printf(s
, "%s\n", core
->parent_names
[i
]);
2791 DEFINE_SHOW_ATTRIBUTE(possible_parents
);
2793 static int clk_duty_cycle_show(struct seq_file
*s
, void *data
)
2795 struct clk_core
*core
= s
->private;
2796 struct clk_duty
*duty
= &core
->duty
;
2798 seq_printf(s
, "%u/%u\n", duty
->num
, duty
->den
);
2802 DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle
);
2804 static void clk_debug_create_one(struct clk_core
*core
, struct dentry
*pdentry
)
2806 struct dentry
*root
;
2808 if (!core
|| !pdentry
)
2811 root
= debugfs_create_dir(core
->name
, pdentry
);
2812 core
->dentry
= root
;
2814 debugfs_create_ulong("clk_rate", 0444, root
, &core
->rate
);
2815 debugfs_create_ulong("clk_accuracy", 0444, root
, &core
->accuracy
);
2816 debugfs_create_u32("clk_phase", 0444, root
, &core
->phase
);
2817 debugfs_create_file("clk_flags", 0444, root
, core
, &clk_flags_fops
);
2818 debugfs_create_u32("clk_prepare_count", 0444, root
, &core
->prepare_count
);
2819 debugfs_create_u32("clk_enable_count", 0444, root
, &core
->enable_count
);
2820 debugfs_create_u32("clk_protect_count", 0444, root
, &core
->protect_count
);
2821 debugfs_create_u32("clk_notifier_count", 0444, root
, &core
->notifier_count
);
2822 debugfs_create_file("clk_duty_cycle", 0444, root
, core
,
2823 &clk_duty_cycle_fops
);
2825 if (core
->num_parents
> 1)
2826 debugfs_create_file("clk_possible_parents", 0444, root
, core
,
2827 &possible_parents_fops
);
2829 if (core
->ops
->debug_init
)
2830 core
->ops
->debug_init(core
->hw
, core
->dentry
);
2834 * clk_debug_register - add a clk node to the debugfs clk directory
2835 * @core: the clk being added to the debugfs clk directory
2837 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
2838 * initialized. Otherwise it bails out early since the debugfs clk directory
2839 * will be created lazily by clk_debug_init as part of a late_initcall.
2841 static void clk_debug_register(struct clk_core
*core
)
2843 mutex_lock(&clk_debug_lock
);
2844 hlist_add_head(&core
->debug_node
, &clk_debug_list
);
2846 clk_debug_create_one(core
, rootdir
);
2847 mutex_unlock(&clk_debug_lock
);
2851 * clk_debug_unregister - remove a clk node from the debugfs clk directory
2852 * @core: the clk being removed from the debugfs clk directory
2854 * Dynamically removes a clk and all its child nodes from the
2855 * debugfs clk directory if clk->dentry points to debugfs created by
2856 * clk_debug_register in __clk_core_init.
2858 static void clk_debug_unregister(struct clk_core
*core
)
2860 mutex_lock(&clk_debug_lock
);
2861 hlist_del_init(&core
->debug_node
);
2862 debugfs_remove_recursive(core
->dentry
);
2863 core
->dentry
= NULL
;
2864 mutex_unlock(&clk_debug_lock
);
2868 * clk_debug_init - lazily populate the debugfs clk directory
2870 * clks are often initialized very early during boot before memory can be
2871 * dynamically allocated and well before debugfs is setup. This function
2872 * populates the debugfs clk directory once at boot-time when we know that
2873 * debugfs is setup. It should only be called once at boot-time, all other clks
2874 * added dynamically will be done so with clk_debug_register.
2876 static int __init
clk_debug_init(void)
2878 struct clk_core
*core
;
2880 rootdir
= debugfs_create_dir("clk", NULL
);
2882 debugfs_create_file("clk_summary", 0444, rootdir
, &all_lists
,
2884 debugfs_create_file("clk_dump", 0444, rootdir
, &all_lists
,
2886 debugfs_create_file("clk_orphan_summary", 0444, rootdir
, &orphan_list
,
2888 debugfs_create_file("clk_orphan_dump", 0444, rootdir
, &orphan_list
,
2891 mutex_lock(&clk_debug_lock
);
2892 hlist_for_each_entry(core
, &clk_debug_list
, debug_node
)
2893 clk_debug_create_one(core
, rootdir
);
2896 mutex_unlock(&clk_debug_lock
);
2900 late_initcall(clk_debug_init
);
2902 static inline void clk_debug_register(struct clk_core
*core
) { }
2903 static inline void clk_debug_reparent(struct clk_core
*core
,
2904 struct clk_core
*new_parent
)
2907 static inline void clk_debug_unregister(struct clk_core
*core
)
2913 * __clk_core_init - initialize the data structures in a struct clk_core
2914 * @core: clk_core being initialized
2916 * Initializes the lists in struct clk_core, queries the hardware for the
2917 * parent and rate and sets them both.
2919 static int __clk_core_init(struct clk_core
*core
)
2922 struct clk_core
*orphan
;
2923 struct hlist_node
*tmp2
;
2931 ret
= clk_pm_runtime_get(core
);
2935 /* check to see if a clock with this name is already registered */
2936 if (clk_core_lookup(core
->name
)) {
2937 pr_debug("%s: clk %s already initialized\n",
2938 __func__
, core
->name
);
2943 /* check that clk_ops are sane. See Documentation/driver-api/clk.rst */
2944 if (core
->ops
->set_rate
&&
2945 !((core
->ops
->round_rate
|| core
->ops
->determine_rate
) &&
2946 core
->ops
->recalc_rate
)) {
2947 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
2948 __func__
, core
->name
);
2953 if (core
->ops
->set_parent
&& !core
->ops
->get_parent
) {
2954 pr_err("%s: %s must implement .get_parent & .set_parent\n",
2955 __func__
, core
->name
);
2960 if (core
->num_parents
> 1 && !core
->ops
->get_parent
) {
2961 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
2962 __func__
, core
->name
);
2967 if (core
->ops
->set_rate_and_parent
&&
2968 !(core
->ops
->set_parent
&& core
->ops
->set_rate
)) {
2969 pr_err("%s: %s must implement .set_parent & .set_rate\n",
2970 __func__
, core
->name
);
2975 /* throw a WARN if any entries in parent_names are NULL */
2976 for (i
= 0; i
< core
->num_parents
; i
++)
2977 WARN(!core
->parent_names
[i
],
2978 "%s: invalid NULL in %s's .parent_names\n",
2979 __func__
, core
->name
);
2981 core
->parent
= __clk_init_parent(core
);
2984 * Populate core->parent if parent has already been clk_core_init'd. If
2985 * parent has not yet been clk_core_init'd then place clk in the orphan
2986 * list. If clk doesn't have any parents then place it in the root
2989 * Every time a new clk is clk_init'd then we walk the list of orphan
2990 * clocks and re-parent any that are children of the clock currently
2994 hlist_add_head(&core
->child_node
,
2995 &core
->parent
->children
);
2996 core
->orphan
= core
->parent
->orphan
;
2997 } else if (!core
->num_parents
) {
2998 hlist_add_head(&core
->child_node
, &clk_root_list
);
2999 core
->orphan
= false;
3001 hlist_add_head(&core
->child_node
, &clk_orphan_list
);
3002 core
->orphan
= true;
3006 * optional platform-specific magic
3008 * The .init callback is not used by any of the basic clock types, but
3009 * exists for weird hardware that must perform initialization magic.
3010 * Please consider other ways of solving initialization problems before
3011 * using this callback, as its use is discouraged.
3013 if (core
->ops
->init
)
3014 core
->ops
->init(core
->hw
);
3017 * Set clk's accuracy. The preferred method is to use
3018 * .recalc_accuracy. For simple clocks and lazy developers the default
3019 * fallback is to use the parent's accuracy. If a clock doesn't have a
3020 * parent (or is orphaned) then accuracy is set to zero (perfect
3023 if (core
->ops
->recalc_accuracy
)
3024 core
->accuracy
= core
->ops
->recalc_accuracy(core
->hw
,
3025 __clk_get_accuracy(core
->parent
));
3026 else if (core
->parent
)
3027 core
->accuracy
= core
->parent
->accuracy
;
3033 * Since a phase is by definition relative to its parent, just
3034 * query the current clock phase, or just assume it's in phase.
3036 if (core
->ops
->get_phase
)
3037 core
->phase
= core
->ops
->get_phase(core
->hw
);
3042 * Set clk's duty cycle.
3044 clk_core_update_duty_cycle_nolock(core
);
3047 * Set clk's rate. The preferred method is to use .recalc_rate. For
3048 * simple clocks and lazy developers the default fallback is to use the
3049 * parent's rate. If a clock doesn't have a parent (or is orphaned)
3050 * then rate is set to zero.
3052 if (core
->ops
->recalc_rate
)
3053 rate
= core
->ops
->recalc_rate(core
->hw
,
3054 clk_core_get_rate_nolock(core
->parent
));
3055 else if (core
->parent
)
3056 rate
= core
->parent
->rate
;
3059 core
->rate
= core
->req_rate
= rate
;
3062 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
3063 * don't get accidentally disabled when walking the orphan tree and
3064 * reparenting clocks
3066 if (core
->flags
& CLK_IS_CRITICAL
) {
3067 unsigned long flags
;
3069 clk_core_prepare(core
);
3071 flags
= clk_enable_lock();
3072 clk_core_enable(core
);
3073 clk_enable_unlock(flags
);
3077 * walk the list of orphan clocks and reparent any that newly finds a
3080 hlist_for_each_entry_safe(orphan
, tmp2
, &clk_orphan_list
, child_node
) {
3081 struct clk_core
*parent
= __clk_init_parent(orphan
);
3084 * We need to use __clk_set_parent_before() and _after() to
3085 * to properly migrate any prepare/enable count of the orphan
3086 * clock. This is important for CLK_IS_CRITICAL clocks, which
3087 * are enabled during init but might not have a parent yet.
3090 /* update the clk tree topology */
3091 __clk_set_parent_before(orphan
, parent
);
3092 __clk_set_parent_after(orphan
, parent
, NULL
);
3093 __clk_recalc_accuracies(orphan
);
3094 __clk_recalc_rates(orphan
, 0);
3098 kref_init(&core
->ref
);
3100 clk_pm_runtime_put(core
);
3102 clk_prepare_unlock();
3105 clk_debug_register(core
);
3110 struct clk
*__clk_create_clk(struct clk_hw
*hw
, const char *dev_id
,
3115 /* This is to allow this function to be chained to others */
3116 if (IS_ERR_OR_NULL(hw
))
3117 return ERR_CAST(hw
);
3119 clk
= kzalloc(sizeof(*clk
), GFP_KERNEL
);
3121 return ERR_PTR(-ENOMEM
);
3123 clk
->core
= hw
->core
;
3124 clk
->dev_id
= dev_id
;
3125 clk
->con_id
= kstrdup_const(con_id
, GFP_KERNEL
);
3126 clk
->max_rate
= ULONG_MAX
;
3129 hlist_add_head(&clk
->clks_node
, &hw
->core
->clks
);
3130 clk_prepare_unlock();
3135 /* keep in sync with __clk_put */
3136 void __clk_free_clk(struct clk
*clk
)
3139 hlist_del(&clk
->clks_node
);
3140 clk_prepare_unlock();
3142 kfree_const(clk
->con_id
);
3147 * clk_register - allocate a new clock, register it and return an opaque cookie
3148 * @dev: device that is registering this clock
3149 * @hw: link to hardware-specific clock data
3151 * clk_register is the primary interface for populating the clock tree with new
3152 * clock nodes. It returns a pointer to the newly allocated struct clk which
3153 * cannot be dereferenced by driver code but may be used in conjunction with the
3154 * rest of the clock API. In the event of an error clk_register will return an
3155 * error code; drivers must test for an error code after calling clk_register.
3157 struct clk
*clk_register(struct device
*dev
, struct clk_hw
*hw
)
3160 struct clk_core
*core
;
3162 core
= kzalloc(sizeof(*core
), GFP_KERNEL
);
3168 core
->name
= kstrdup_const(hw
->init
->name
, GFP_KERNEL
);
3174 if (WARN_ON(!hw
->init
->ops
)) {
3178 core
->ops
= hw
->init
->ops
;
3180 if (dev
&& pm_runtime_enabled(dev
))
3182 if (dev
&& dev
->driver
)
3183 core
->owner
= dev
->driver
->owner
;
3185 core
->flags
= hw
->init
->flags
;
3186 core
->num_parents
= hw
->init
->num_parents
;
3188 core
->max_rate
= ULONG_MAX
;
3191 /* allocate local copy in case parent_names is __initdata */
3192 core
->parent_names
= kcalloc(core
->num_parents
, sizeof(char *),
3195 if (!core
->parent_names
) {
3197 goto fail_parent_names
;
3201 /* copy each string name in case parent_names is __initdata */
3202 for (i
= 0; i
< core
->num_parents
; i
++) {
3203 core
->parent_names
[i
] = kstrdup_const(hw
->init
->parent_names
[i
],
3205 if (!core
->parent_names
[i
]) {
3207 goto fail_parent_names_copy
;
3211 /* avoid unnecessary string look-ups of clk_core's possible parents. */
3212 core
->parents
= kcalloc(core
->num_parents
, sizeof(*core
->parents
),
3214 if (!core
->parents
) {
3219 INIT_HLIST_HEAD(&core
->clks
);
3221 hw
->clk
= __clk_create_clk(hw
, NULL
, NULL
);
3222 if (IS_ERR(hw
->clk
)) {
3223 ret
= PTR_ERR(hw
->clk
);
3227 ret
= __clk_core_init(core
);
3231 __clk_free_clk(hw
->clk
);
3235 kfree(core
->parents
);
3236 fail_parent_names_copy
:
3238 kfree_const(core
->parent_names
[i
]);
3239 kfree(core
->parent_names
);
3242 kfree_const(core
->name
);
3246 return ERR_PTR(ret
);
3248 EXPORT_SYMBOL_GPL(clk_register
);
3251 * clk_hw_register - register a clk_hw and return an error code
3252 * @dev: device that is registering this clock
3253 * @hw: link to hardware-specific clock data
3255 * clk_hw_register is the primary interface for populating the clock tree with
3256 * new clock nodes. It returns an integer equal to zero indicating success or
3257 * less than zero indicating failure. Drivers must test for an error code after
3258 * calling clk_hw_register().
3260 int clk_hw_register(struct device
*dev
, struct clk_hw
*hw
)
3262 return PTR_ERR_OR_ZERO(clk_register(dev
, hw
));
3264 EXPORT_SYMBOL_GPL(clk_hw_register
);
3266 /* Free memory allocated for a clock. */
3267 static void __clk_release(struct kref
*ref
)
3269 struct clk_core
*core
= container_of(ref
, struct clk_core
, ref
);
3270 int i
= core
->num_parents
;
3272 lockdep_assert_held(&prepare_lock
);
3274 kfree(core
->parents
);
3276 kfree_const(core
->parent_names
[i
]);
3278 kfree(core
->parent_names
);
3279 kfree_const(core
->name
);
3284 * Empty clk_ops for unregistered clocks. These are used temporarily
3285 * after clk_unregister() was called on a clock and until last clock
3286 * consumer calls clk_put() and the struct clk object is freed.
3288 static int clk_nodrv_prepare_enable(struct clk_hw
*hw
)
3293 static void clk_nodrv_disable_unprepare(struct clk_hw
*hw
)
3298 static int clk_nodrv_set_rate(struct clk_hw
*hw
, unsigned long rate
,
3299 unsigned long parent_rate
)
3304 static int clk_nodrv_set_parent(struct clk_hw
*hw
, u8 index
)
3309 static const struct clk_ops clk_nodrv_ops
= {
3310 .enable
= clk_nodrv_prepare_enable
,
3311 .disable
= clk_nodrv_disable_unprepare
,
3312 .prepare
= clk_nodrv_prepare_enable
,
3313 .unprepare
= clk_nodrv_disable_unprepare
,
3314 .set_rate
= clk_nodrv_set_rate
,
3315 .set_parent
= clk_nodrv_set_parent
,
3319 * clk_unregister - unregister a currently registered clock
3320 * @clk: clock to unregister
3322 void clk_unregister(struct clk
*clk
)
3324 unsigned long flags
;
3326 if (!clk
|| WARN_ON_ONCE(IS_ERR(clk
)))
3329 clk_debug_unregister(clk
->core
);
3333 if (clk
->core
->ops
== &clk_nodrv_ops
) {
3334 pr_err("%s: unregistered clock: %s\n", __func__
,
3339 * Assign empty clock ops for consumers that might still hold
3340 * a reference to this clock.
3342 flags
= clk_enable_lock();
3343 clk
->core
->ops
= &clk_nodrv_ops
;
3344 clk_enable_unlock(flags
);
3346 if (!hlist_empty(&clk
->core
->children
)) {
3347 struct clk_core
*child
;
3348 struct hlist_node
*t
;
3350 /* Reparent all children to the orphan list. */
3351 hlist_for_each_entry_safe(child
, t
, &clk
->core
->children
,
3353 clk_core_set_parent_nolock(child
, NULL
);
3356 hlist_del_init(&clk
->core
->child_node
);
3358 if (clk
->core
->prepare_count
)
3359 pr_warn("%s: unregistering prepared clock: %s\n",
3360 __func__
, clk
->core
->name
);
3362 if (clk
->core
->protect_count
)
3363 pr_warn("%s: unregistering protected clock: %s\n",
3364 __func__
, clk
->core
->name
);
3366 kref_put(&clk
->core
->ref
, __clk_release
);
3368 clk_prepare_unlock();
3370 EXPORT_SYMBOL_GPL(clk_unregister
);
3373 * clk_hw_unregister - unregister a currently registered clk_hw
3374 * @hw: hardware-specific clock data to unregister
3376 void clk_hw_unregister(struct clk_hw
*hw
)
3378 clk_unregister(hw
->clk
);
3380 EXPORT_SYMBOL_GPL(clk_hw_unregister
);
3382 static void devm_clk_release(struct device
*dev
, void *res
)
3384 clk_unregister(*(struct clk
**)res
);
3387 static void devm_clk_hw_release(struct device
*dev
, void *res
)
3389 clk_hw_unregister(*(struct clk_hw
**)res
);
3393 * devm_clk_register - resource managed clk_register()
3394 * @dev: device that is registering this clock
3395 * @hw: link to hardware-specific clock data
3397 * Managed clk_register(). Clocks returned from this function are
3398 * automatically clk_unregister()ed on driver detach. See clk_register() for
3401 struct clk
*devm_clk_register(struct device
*dev
, struct clk_hw
*hw
)
3406 clkp
= devres_alloc(devm_clk_release
, sizeof(*clkp
), GFP_KERNEL
);
3408 return ERR_PTR(-ENOMEM
);
3410 clk
= clk_register(dev
, hw
);
3413 devres_add(dev
, clkp
);
3420 EXPORT_SYMBOL_GPL(devm_clk_register
);
3423 * devm_clk_hw_register - resource managed clk_hw_register()
3424 * @dev: device that is registering this clock
3425 * @hw: link to hardware-specific clock data
3427 * Managed clk_hw_register(). Clocks registered by this function are
3428 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
3429 * for more information.
3431 int devm_clk_hw_register(struct device
*dev
, struct clk_hw
*hw
)
3433 struct clk_hw
**hwp
;
3436 hwp
= devres_alloc(devm_clk_hw_release
, sizeof(*hwp
), GFP_KERNEL
);
3440 ret
= clk_hw_register(dev
, hw
);
3443 devres_add(dev
, hwp
);
3450 EXPORT_SYMBOL_GPL(devm_clk_hw_register
);
3452 static int devm_clk_match(struct device
*dev
, void *res
, void *data
)
3454 struct clk
*c
= res
;
3460 static int devm_clk_hw_match(struct device
*dev
, void *res
, void *data
)
3462 struct clk_hw
*hw
= res
;
3470 * devm_clk_unregister - resource managed clk_unregister()
3471 * @clk: clock to unregister
3473 * Deallocate a clock allocated with devm_clk_register(). Normally
3474 * this function will not need to be called and the resource management
3475 * code will ensure that the resource is freed.
3477 void devm_clk_unregister(struct device
*dev
, struct clk
*clk
)
3479 WARN_ON(devres_release(dev
, devm_clk_release
, devm_clk_match
, clk
));
3481 EXPORT_SYMBOL_GPL(devm_clk_unregister
);
3484 * devm_clk_hw_unregister - resource managed clk_hw_unregister()
3485 * @dev: device that is unregistering the hardware-specific clock data
3486 * @hw: link to hardware-specific clock data
3488 * Unregister a clk_hw registered with devm_clk_hw_register(). Normally
3489 * this function will not need to be called and the resource management
3490 * code will ensure that the resource is freed.
3492 void devm_clk_hw_unregister(struct device
*dev
, struct clk_hw
*hw
)
3494 WARN_ON(devres_release(dev
, devm_clk_hw_release
, devm_clk_hw_match
,
3497 EXPORT_SYMBOL_GPL(devm_clk_hw_unregister
);
3502 int __clk_get(struct clk
*clk
)
3504 struct clk_core
*core
= !clk
? NULL
: clk
->core
;
3507 if (!try_module_get(core
->owner
))
3510 kref_get(&core
->ref
);
3515 /* keep in sync with __clk_free_clk */
3516 void __clk_put(struct clk
*clk
)
3518 struct module
*owner
;
3520 if (!clk
|| WARN_ON_ONCE(IS_ERR(clk
)))
3526 * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
3527 * given user should be balanced with calls to clk_rate_exclusive_put()
3528 * and by that same consumer
3530 if (WARN_ON(clk
->exclusive_count
)) {
3531 /* We voiced our concern, let's sanitize the situation */
3532 clk
->core
->protect_count
-= (clk
->exclusive_count
- 1);
3533 clk_core_rate_unprotect(clk
->core
);
3534 clk
->exclusive_count
= 0;
3537 hlist_del(&clk
->clks_node
);
3538 if (clk
->min_rate
> clk
->core
->req_rate
||
3539 clk
->max_rate
< clk
->core
->req_rate
)
3540 clk_core_set_rate_nolock(clk
->core
, clk
->core
->req_rate
);
3542 owner
= clk
->core
->owner
;
3543 kref_put(&clk
->core
->ref
, __clk_release
);
3545 clk_prepare_unlock();
3549 kfree_const(clk
->con_id
);
3553 /*** clk rate change notifiers ***/
3556 * clk_notifier_register - add a clk rate change notifier
3557 * @clk: struct clk * to watch
3558 * @nb: struct notifier_block * with callback info
3560 * Request notification when clk's rate changes. This uses an SRCU
3561 * notifier because we want it to block and notifier unregistrations are
3562 * uncommon. The callbacks associated with the notifier must not
3563 * re-enter into the clk framework by calling any top-level clk APIs;
3564 * this will cause a nested prepare_lock mutex.
3566 * In all notification cases (pre, post and abort rate change) the original
3567 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
3568 * and the new frequency is passed via struct clk_notifier_data.new_rate.
3570 * clk_notifier_register() must be called from non-atomic context.
3571 * Returns -EINVAL if called with null arguments, -ENOMEM upon
3572 * allocation failure; otherwise, passes along the return value of
3573 * srcu_notifier_chain_register().
3575 int clk_notifier_register(struct clk
*clk
, struct notifier_block
*nb
)
3577 struct clk_notifier
*cn
;
3585 /* search the list of notifiers for this clk */
3586 list_for_each_entry(cn
, &clk_notifier_list
, node
)
3590 /* if clk wasn't in the notifier list, allocate new clk_notifier */
3591 if (cn
->clk
!= clk
) {
3592 cn
= kzalloc(sizeof(*cn
), GFP_KERNEL
);
3597 srcu_init_notifier_head(&cn
->notifier_head
);
3599 list_add(&cn
->node
, &clk_notifier_list
);
3602 ret
= srcu_notifier_chain_register(&cn
->notifier_head
, nb
);
3604 clk
->core
->notifier_count
++;
3607 clk_prepare_unlock();
3611 EXPORT_SYMBOL_GPL(clk_notifier_register
);
3614 * clk_notifier_unregister - remove a clk rate change notifier
3615 * @clk: struct clk *
3616 * @nb: struct notifier_block * with callback info
3618 * Request no further notification for changes to 'clk' and frees memory
3619 * allocated in clk_notifier_register.
3621 * Returns -EINVAL if called with null arguments; otherwise, passes
3622 * along the return value of srcu_notifier_chain_unregister().
3624 int clk_notifier_unregister(struct clk
*clk
, struct notifier_block
*nb
)
3626 struct clk_notifier
*cn
= NULL
;
3634 list_for_each_entry(cn
, &clk_notifier_list
, node
)
3638 if (cn
->clk
== clk
) {
3639 ret
= srcu_notifier_chain_unregister(&cn
->notifier_head
, nb
);
3641 clk
->core
->notifier_count
--;
3643 /* XXX the notifier code should handle this better */
3644 if (!cn
->notifier_head
.head
) {
3645 srcu_cleanup_notifier_head(&cn
->notifier_head
);
3646 list_del(&cn
->node
);
3654 clk_prepare_unlock();
3658 EXPORT_SYMBOL_GPL(clk_notifier_unregister
);
3662 * struct of_clk_provider - Clock provider registration structure
3663 * @link: Entry in global list of clock providers
3664 * @node: Pointer to device tree node of clock provider
3665 * @get: Get clock callback. Returns NULL or a struct clk for the
3666 * given clock specifier
3667 * @data: context pointer to be passed into @get callback
3669 struct of_clk_provider
{
3670 struct list_head link
;
3672 struct device_node
*node
;
3673 struct clk
*(*get
)(struct of_phandle_args
*clkspec
, void *data
);
3674 struct clk_hw
*(*get_hw
)(struct of_phandle_args
*clkspec
, void *data
);
3678 static const struct of_device_id __clk_of_table_sentinel
3679 __used
__section(__clk_of_table_end
);
3681 static LIST_HEAD(of_clk_providers
);
3682 static DEFINE_MUTEX(of_clk_mutex
);
3684 struct clk
*of_clk_src_simple_get(struct of_phandle_args
*clkspec
,
3689 EXPORT_SYMBOL_GPL(of_clk_src_simple_get
);
3691 struct clk_hw
*of_clk_hw_simple_get(struct of_phandle_args
*clkspec
, void *data
)
3695 EXPORT_SYMBOL_GPL(of_clk_hw_simple_get
);
3697 struct clk
*of_clk_src_onecell_get(struct of_phandle_args
*clkspec
, void *data
)
3699 struct clk_onecell_data
*clk_data
= data
;
3700 unsigned int idx
= clkspec
->args
[0];
3702 if (idx
>= clk_data
->clk_num
) {
3703 pr_err("%s: invalid clock index %u\n", __func__
, idx
);
3704 return ERR_PTR(-EINVAL
);
3707 return clk_data
->clks
[idx
];
3709 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get
);
3712 of_clk_hw_onecell_get(struct of_phandle_args
*clkspec
, void *data
)
3714 struct clk_hw_onecell_data
*hw_data
= data
;
3715 unsigned int idx
= clkspec
->args
[0];
3717 if (idx
>= hw_data
->num
) {
3718 pr_err("%s: invalid index %u\n", __func__
, idx
);
3719 return ERR_PTR(-EINVAL
);
3722 return hw_data
->hws
[idx
];
3724 EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get
);
3727 * of_clk_add_provider() - Register a clock provider for a node
3728 * @np: Device node pointer associated with clock provider
3729 * @clk_src_get: callback for decoding clock
3730 * @data: context pointer for @clk_src_get callback.
3732 int of_clk_add_provider(struct device_node
*np
,
3733 struct clk
*(*clk_src_get
)(struct of_phandle_args
*clkspec
,
3737 struct of_clk_provider
*cp
;
3740 cp
= kzalloc(sizeof(*cp
), GFP_KERNEL
);
3744 cp
->node
= of_node_get(np
);
3746 cp
->get
= clk_src_get
;
3748 mutex_lock(&of_clk_mutex
);
3749 list_add(&cp
->link
, &of_clk_providers
);
3750 mutex_unlock(&of_clk_mutex
);
3751 pr_debug("Added clock from %pOF\n", np
);
3753 ret
= of_clk_set_defaults(np
, true);
3755 of_clk_del_provider(np
);
3759 EXPORT_SYMBOL_GPL(of_clk_add_provider
);
3762 * of_clk_add_hw_provider() - Register a clock provider for a node
3763 * @np: Device node pointer associated with clock provider
3764 * @get: callback for decoding clk_hw
3765 * @data: context pointer for @get callback.
3767 int of_clk_add_hw_provider(struct device_node
*np
,
3768 struct clk_hw
*(*get
)(struct of_phandle_args
*clkspec
,
3772 struct of_clk_provider
*cp
;
3775 cp
= kzalloc(sizeof(*cp
), GFP_KERNEL
);
3779 cp
->node
= of_node_get(np
);
3783 mutex_lock(&of_clk_mutex
);
3784 list_add(&cp
->link
, &of_clk_providers
);
3785 mutex_unlock(&of_clk_mutex
);
3786 pr_debug("Added clk_hw provider from %pOF\n", np
);
3788 ret
= of_clk_set_defaults(np
, true);
3790 of_clk_del_provider(np
);
3794 EXPORT_SYMBOL_GPL(of_clk_add_hw_provider
);
3796 static void devm_of_clk_release_provider(struct device
*dev
, void *res
)
3798 of_clk_del_provider(*(struct device_node
**)res
);
3801 int devm_of_clk_add_hw_provider(struct device
*dev
,
3802 struct clk_hw
*(*get
)(struct of_phandle_args
*clkspec
,
3806 struct device_node
**ptr
, *np
;
3809 ptr
= devres_alloc(devm_of_clk_release_provider
, sizeof(*ptr
),
3815 ret
= of_clk_add_hw_provider(np
, get
, data
);
3818 devres_add(dev
, ptr
);
3825 EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider
);
3828 * of_clk_del_provider() - Remove a previously registered clock provider
3829 * @np: Device node pointer associated with clock provider
3831 void of_clk_del_provider(struct device_node
*np
)
3833 struct of_clk_provider
*cp
;
3835 mutex_lock(&of_clk_mutex
);
3836 list_for_each_entry(cp
, &of_clk_providers
, link
) {
3837 if (cp
->node
== np
) {
3838 list_del(&cp
->link
);
3839 of_node_put(cp
->node
);
3844 mutex_unlock(&of_clk_mutex
);
3846 EXPORT_SYMBOL_GPL(of_clk_del_provider
);
3848 static int devm_clk_provider_match(struct device
*dev
, void *res
, void *data
)
3850 struct device_node
**np
= res
;
3852 if (WARN_ON(!np
|| !*np
))
3858 void devm_of_clk_del_provider(struct device
*dev
)
3862 ret
= devres_release(dev
, devm_of_clk_release_provider
,
3863 devm_clk_provider_match
, dev
->of_node
);
3867 EXPORT_SYMBOL(devm_of_clk_del_provider
);
3869 static struct clk_hw
*
3870 __of_clk_get_hw_from_provider(struct of_clk_provider
*provider
,
3871 struct of_phandle_args
*clkspec
)
3875 if (provider
->get_hw
)
3876 return provider
->get_hw(clkspec
, provider
->data
);
3878 clk
= provider
->get(clkspec
, provider
->data
);
3880 return ERR_CAST(clk
);
3881 return __clk_get_hw(clk
);
3884 struct clk
*__of_clk_get_from_provider(struct of_phandle_args
*clkspec
,
3885 const char *dev_id
, const char *con_id
)
3887 struct of_clk_provider
*provider
;
3888 struct clk
*clk
= ERR_PTR(-EPROBE_DEFER
);
3892 return ERR_PTR(-EINVAL
);
3894 /* Check if we have such a provider in our array */
3895 mutex_lock(&of_clk_mutex
);
3896 list_for_each_entry(provider
, &of_clk_providers
, link
) {
3897 if (provider
->node
== clkspec
->np
) {
3898 hw
= __of_clk_get_hw_from_provider(provider
, clkspec
);
3899 clk
= __clk_create_clk(hw
, dev_id
, con_id
);
3903 if (!__clk_get(clk
)) {
3904 __clk_free_clk(clk
);
3905 clk
= ERR_PTR(-ENOENT
);
3911 mutex_unlock(&of_clk_mutex
);
3917 * of_clk_get_from_provider() - Lookup a clock from a clock provider
3918 * @clkspec: pointer to a clock specifier data structure
3920 * This function looks up a struct clk from the registered list of clock
3921 * providers, an input is a clock specifier data structure as returned
3922 * from the of_parse_phandle_with_args() function call.
3924 struct clk
*of_clk_get_from_provider(struct of_phandle_args
*clkspec
)
3926 return __of_clk_get_from_provider(clkspec
, NULL
, __func__
);
3928 EXPORT_SYMBOL_GPL(of_clk_get_from_provider
);
3931 * of_clk_get_parent_count() - Count the number of clocks a device node has
3932 * @np: device node to count
3934 * Returns: The number of clocks that are possible parents of this node
3936 unsigned int of_clk_get_parent_count(struct device_node
*np
)
3940 count
= of_count_phandle_with_args(np
, "clocks", "#clock-cells");
3946 EXPORT_SYMBOL_GPL(of_clk_get_parent_count
);
3948 const char *of_clk_get_parent_name(struct device_node
*np
, int index
)
3950 struct of_phandle_args clkspec
;
3951 struct property
*prop
;
3952 const char *clk_name
;
3959 rc
= of_parse_phandle_with_args(np
, "clocks", "#clock-cells", index
,
3964 index
= clkspec
.args_count
? clkspec
.args
[0] : 0;
3967 /* if there is an indices property, use it to transfer the index
3968 * specified into an array offset for the clock-output-names property.
3970 of_property_for_each_u32(clkspec
.np
, "clock-indices", prop
, vp
, pv
) {
3977 /* We went off the end of 'clock-indices' without finding it */
3981 if (of_property_read_string_index(clkspec
.np
, "clock-output-names",
3985 * Best effort to get the name if the clock has been
3986 * registered with the framework. If the clock isn't
3987 * registered, we return the node name as the name of
3988 * the clock as long as #clock-cells = 0.
3990 clk
= of_clk_get_from_provider(&clkspec
);
3992 if (clkspec
.args_count
== 0)
3993 clk_name
= clkspec
.np
->name
;
3997 clk_name
= __clk_get_name(clk
);
4003 of_node_put(clkspec
.np
);
4006 EXPORT_SYMBOL_GPL(of_clk_get_parent_name
);
4009 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
4011 * @np: Device node pointer associated with clock provider
4012 * @parents: pointer to char array that hold the parents' names
4013 * @size: size of the @parents array
4015 * Return: number of parents for the clock node.
4017 int of_clk_parent_fill(struct device_node
*np
, const char **parents
,
4022 while (i
< size
&& (parents
[i
] = of_clk_get_parent_name(np
, i
)) != NULL
)
4027 EXPORT_SYMBOL_GPL(of_clk_parent_fill
);
4029 struct clock_provider
{
4030 void (*clk_init_cb
)(struct device_node
*);
4031 struct device_node
*np
;
4032 struct list_head node
;
4036 * This function looks for a parent clock. If there is one, then it
4037 * checks that the provider for this parent clock was initialized, in
4038 * this case the parent clock will be ready.
4040 static int parent_ready(struct device_node
*np
)
4045 struct clk
*clk
= of_clk_get(np
, i
);
4047 /* this parent is ready we can check the next one */
4054 /* at least one parent is not ready, we exit now */
4055 if (PTR_ERR(clk
) == -EPROBE_DEFER
)
4059 * Here we make assumption that the device tree is
4060 * written correctly. So an error means that there is
4061 * no more parent. As we didn't exit yet, then the
4062 * previous parent are ready. If there is no clock
4063 * parent, no need to wait for them, then we can
4064 * consider their absence as being ready
4071 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
4072 * @np: Device node pointer associated with clock provider
4073 * @index: clock index
4074 * @flags: pointer to top-level framework flags
4076 * Detects if the clock-critical property exists and, if so, sets the
4077 * corresponding CLK_IS_CRITICAL flag.
4079 * Do not use this function. It exists only for legacy Device Tree
4080 * bindings, such as the one-clock-per-node style that are outdated.
4081 * Those bindings typically put all clock data into .dts and the Linux
4082 * driver has no clock data, thus making it impossible to set this flag
4083 * correctly from the driver. Only those drivers may call
4084 * of_clk_detect_critical from their setup functions.
4086 * Return: error code or zero on success
4088 int of_clk_detect_critical(struct device_node
*np
,
4089 int index
, unsigned long *flags
)
4091 struct property
*prop
;
4098 of_property_for_each_u32(np
, "clock-critical", prop
, cur
, idx
)
4100 *flags
|= CLK_IS_CRITICAL
;
4106 * of_clk_init() - Scan and init clock providers from the DT
4107 * @matches: array of compatible values and init functions for providers.
4109 * This function scans the device tree for matching clock providers
4110 * and calls their initialization functions. It also does it by trying
4111 * to follow the dependencies.
4113 void __init
of_clk_init(const struct of_device_id
*matches
)
4115 const struct of_device_id
*match
;
4116 struct device_node
*np
;
4117 struct clock_provider
*clk_provider
, *next
;
4120 LIST_HEAD(clk_provider_list
);
4123 matches
= &__clk_of_table
;
4125 /* First prepare the list of the clocks providers */
4126 for_each_matching_node_and_match(np
, matches
, &match
) {
4127 struct clock_provider
*parent
;
4129 if (!of_device_is_available(np
))
4132 parent
= kzalloc(sizeof(*parent
), GFP_KERNEL
);
4134 list_for_each_entry_safe(clk_provider
, next
,
4135 &clk_provider_list
, node
) {
4136 list_del(&clk_provider
->node
);
4137 of_node_put(clk_provider
->np
);
4138 kfree(clk_provider
);
4144 parent
->clk_init_cb
= match
->data
;
4145 parent
->np
= of_node_get(np
);
4146 list_add_tail(&parent
->node
, &clk_provider_list
);
4149 while (!list_empty(&clk_provider_list
)) {
4150 is_init_done
= false;
4151 list_for_each_entry_safe(clk_provider
, next
,
4152 &clk_provider_list
, node
) {
4153 if (force
|| parent_ready(clk_provider
->np
)) {
4155 /* Don't populate platform devices */
4156 of_node_set_flag(clk_provider
->np
,
4159 clk_provider
->clk_init_cb(clk_provider
->np
);
4160 of_clk_set_defaults(clk_provider
->np
, true);
4162 list_del(&clk_provider
->node
);
4163 of_node_put(clk_provider
->np
);
4164 kfree(clk_provider
);
4165 is_init_done
= true;
4170 * We didn't manage to initialize any of the
4171 * remaining providers during the last loop, so now we
4172 * initialize all the remaining ones unconditionally
4173 * in case the clock parent was not mandatory