2 * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
3 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * Standard functionality for the common clock API. See Documentation/clk.txt
12 #include <linux/clk.h>
13 #include <linux/clk-provider.h>
14 #include <linux/clk/clk-conf.h>
15 #include <linux/module.h>
16 #include <linux/mutex.h>
17 #include <linux/spinlock.h>
18 #include <linux/err.h>
19 #include <linux/list.h>
20 #include <linux/slab.h>
22 #include <linux/device.h>
23 #include <linux/init.h>
24 #include <linux/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 long min_rate
;
66 unsigned long max_rate
;
67 unsigned long accuracy
;
69 struct hlist_head children
;
70 struct hlist_node child_node
;
71 struct hlist_head clks
;
72 unsigned int notifier_count
;
73 #ifdef CONFIG_DEBUG_FS
74 struct dentry
*dentry
;
75 struct hlist_node debug_node
;
80 #define CREATE_TRACE_POINTS
81 #include <trace/events/clk.h>
84 struct clk_core
*core
;
87 unsigned long min_rate
;
88 unsigned long max_rate
;
89 struct hlist_node clks_node
;
93 static int clk_pm_runtime_get(struct clk_core
*core
)
100 ret
= pm_runtime_get_sync(core
->dev
);
101 return ret
< 0 ? ret
: 0;
104 static void clk_pm_runtime_put(struct clk_core
*core
)
109 pm_runtime_put_sync(core
->dev
);
113 static void clk_prepare_lock(void)
115 if (!mutex_trylock(&prepare_lock
)) {
116 if (prepare_owner
== current
) {
120 mutex_lock(&prepare_lock
);
122 WARN_ON_ONCE(prepare_owner
!= NULL
);
123 WARN_ON_ONCE(prepare_refcnt
!= 0);
124 prepare_owner
= current
;
128 static void clk_prepare_unlock(void)
130 WARN_ON_ONCE(prepare_owner
!= current
);
131 WARN_ON_ONCE(prepare_refcnt
== 0);
133 if (--prepare_refcnt
)
135 prepare_owner
= NULL
;
136 mutex_unlock(&prepare_lock
);
139 static unsigned long clk_enable_lock(void)
140 __acquires(enable_lock
)
144 if (!spin_trylock_irqsave(&enable_lock
, flags
)) {
145 if (enable_owner
== current
) {
147 __acquire(enable_lock
);
150 spin_lock_irqsave(&enable_lock
, flags
);
152 WARN_ON_ONCE(enable_owner
!= NULL
);
153 WARN_ON_ONCE(enable_refcnt
!= 0);
154 enable_owner
= current
;
159 static void clk_enable_unlock(unsigned long flags
)
160 __releases(enable_lock
)
162 WARN_ON_ONCE(enable_owner
!= current
);
163 WARN_ON_ONCE(enable_refcnt
== 0);
165 if (--enable_refcnt
) {
166 __release(enable_lock
);
170 spin_unlock_irqrestore(&enable_lock
, flags
);
173 static bool clk_core_is_prepared(struct clk_core
*core
)
178 * .is_prepared is optional for clocks that can prepare
179 * fall back to software usage counter if it is missing
181 if (!core
->ops
->is_prepared
)
182 return core
->prepare_count
;
184 if (!clk_pm_runtime_get(core
)) {
185 ret
= core
->ops
->is_prepared(core
->hw
);
186 clk_pm_runtime_put(core
);
192 static bool clk_core_is_enabled(struct clk_core
*core
)
197 * .is_enabled is only mandatory for clocks that gate
198 * fall back to software usage counter if .is_enabled is missing
200 if (!core
->ops
->is_enabled
)
201 return core
->enable_count
;
204 * Check if clock controller's device is runtime active before
205 * calling .is_enabled callback. If not, assume that clock is
206 * disabled, because we might be called from atomic context, from
207 * which pm_runtime_get() is not allowed.
208 * This function is called mainly from clk_disable_unused_subtree,
209 * which ensures proper runtime pm activation of controller before
210 * taking enable spinlock, but the below check is needed if one tries
211 * to call it from other places.
214 pm_runtime_get_noresume(core
->dev
);
215 if (!pm_runtime_active(core
->dev
)) {
221 ret
= core
->ops
->is_enabled(core
->hw
);
223 clk_pm_runtime_put(core
);
228 /*** helper functions ***/
230 const char *__clk_get_name(const struct clk
*clk
)
232 return !clk
? NULL
: clk
->core
->name
;
234 EXPORT_SYMBOL_GPL(__clk_get_name
);
236 const char *clk_hw_get_name(const struct clk_hw
*hw
)
238 return hw
->core
->name
;
240 EXPORT_SYMBOL_GPL(clk_hw_get_name
);
242 struct clk_hw
*__clk_get_hw(struct clk
*clk
)
244 return !clk
? NULL
: clk
->core
->hw
;
246 EXPORT_SYMBOL_GPL(__clk_get_hw
);
248 unsigned int clk_hw_get_num_parents(const struct clk_hw
*hw
)
250 return hw
->core
->num_parents
;
252 EXPORT_SYMBOL_GPL(clk_hw_get_num_parents
);
254 struct clk_hw
*clk_hw_get_parent(const struct clk_hw
*hw
)
256 return hw
->core
->parent
? hw
->core
->parent
->hw
: NULL
;
258 EXPORT_SYMBOL_GPL(clk_hw_get_parent
);
260 static struct clk_core
*__clk_lookup_subtree(const char *name
,
261 struct clk_core
*core
)
263 struct clk_core
*child
;
264 struct clk_core
*ret
;
266 if (!strcmp(core
->name
, name
))
269 hlist_for_each_entry(child
, &core
->children
, child_node
) {
270 ret
= __clk_lookup_subtree(name
, child
);
278 static struct clk_core
*clk_core_lookup(const char *name
)
280 struct clk_core
*root_clk
;
281 struct clk_core
*ret
;
286 /* search the 'proper' clk tree first */
287 hlist_for_each_entry(root_clk
, &clk_root_list
, child_node
) {
288 ret
= __clk_lookup_subtree(name
, root_clk
);
293 /* if not found, then search the orphan tree */
294 hlist_for_each_entry(root_clk
, &clk_orphan_list
, child_node
) {
295 ret
= __clk_lookup_subtree(name
, root_clk
);
303 static struct clk_core
*clk_core_get_parent_by_index(struct clk_core
*core
,
306 if (!core
|| index
>= core
->num_parents
)
309 if (!core
->parents
[index
])
310 core
->parents
[index
] =
311 clk_core_lookup(core
->parent_names
[index
]);
313 return core
->parents
[index
];
317 clk_hw_get_parent_by_index(const struct clk_hw
*hw
, unsigned int index
)
319 struct clk_core
*parent
;
321 parent
= clk_core_get_parent_by_index(hw
->core
, index
);
323 return !parent
? NULL
: parent
->hw
;
325 EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index
);
327 unsigned int __clk_get_enable_count(struct clk
*clk
)
329 return !clk
? 0 : clk
->core
->enable_count
;
332 static unsigned long clk_core_get_rate_nolock(struct clk_core
*core
)
343 if (!core
->num_parents
)
353 unsigned long clk_hw_get_rate(const struct clk_hw
*hw
)
355 return clk_core_get_rate_nolock(hw
->core
);
357 EXPORT_SYMBOL_GPL(clk_hw_get_rate
);
359 static unsigned long __clk_get_accuracy(struct clk_core
*core
)
364 return core
->accuracy
;
367 unsigned long __clk_get_flags(struct clk
*clk
)
369 return !clk
? 0 : clk
->core
->flags
;
371 EXPORT_SYMBOL_GPL(__clk_get_flags
);
373 unsigned long clk_hw_get_flags(const struct clk_hw
*hw
)
375 return hw
->core
->flags
;
377 EXPORT_SYMBOL_GPL(clk_hw_get_flags
);
379 bool clk_hw_is_prepared(const struct clk_hw
*hw
)
381 return clk_core_is_prepared(hw
->core
);
384 bool clk_hw_is_enabled(const struct clk_hw
*hw
)
386 return clk_core_is_enabled(hw
->core
);
389 bool __clk_is_enabled(struct clk
*clk
)
394 return clk_core_is_enabled(clk
->core
);
396 EXPORT_SYMBOL_GPL(__clk_is_enabled
);
398 static bool mux_is_better_rate(unsigned long rate
, unsigned long now
,
399 unsigned long best
, unsigned long flags
)
401 if (flags
& CLK_MUX_ROUND_CLOSEST
)
402 return abs(now
- rate
) < abs(best
- rate
);
404 return now
<= rate
&& now
> best
;
408 clk_mux_determine_rate_flags(struct clk_hw
*hw
, struct clk_rate_request
*req
,
411 struct clk_core
*core
= hw
->core
, *parent
, *best_parent
= NULL
;
412 int i
, num_parents
, ret
;
413 unsigned long best
= 0;
414 struct clk_rate_request parent_req
= *req
;
416 /* if NO_REPARENT flag set, pass through to current parent */
417 if (core
->flags
& CLK_SET_RATE_NO_REPARENT
) {
418 parent
= core
->parent
;
419 if (core
->flags
& CLK_SET_RATE_PARENT
) {
420 ret
= __clk_determine_rate(parent
? parent
->hw
: NULL
,
425 best
= parent_req
.rate
;
427 best
= clk_core_get_rate_nolock(parent
);
429 best
= clk_core_get_rate_nolock(core
);
435 /* find the parent that can provide the fastest rate <= rate */
436 num_parents
= core
->num_parents
;
437 for (i
= 0; i
< num_parents
; i
++) {
438 parent
= clk_core_get_parent_by_index(core
, i
);
442 if (core
->flags
& CLK_SET_RATE_PARENT
) {
444 ret
= __clk_determine_rate(parent
->hw
, &parent_req
);
448 parent_req
.rate
= clk_core_get_rate_nolock(parent
);
451 if (mux_is_better_rate(req
->rate
, parent_req
.rate
,
453 best_parent
= parent
;
454 best
= parent_req
.rate
;
463 req
->best_parent_hw
= best_parent
->hw
;
464 req
->best_parent_rate
= best
;
470 struct clk
*__clk_lookup(const char *name
)
472 struct clk_core
*core
= clk_core_lookup(name
);
474 return !core
? NULL
: core
->hw
->clk
;
477 static void clk_core_get_boundaries(struct clk_core
*core
,
478 unsigned long *min_rate
,
479 unsigned long *max_rate
)
481 struct clk
*clk_user
;
483 *min_rate
= core
->min_rate
;
484 *max_rate
= core
->max_rate
;
486 hlist_for_each_entry(clk_user
, &core
->clks
, clks_node
)
487 *min_rate
= max(*min_rate
, clk_user
->min_rate
);
489 hlist_for_each_entry(clk_user
, &core
->clks
, clks_node
)
490 *max_rate
= min(*max_rate
, clk_user
->max_rate
);
493 void clk_hw_set_rate_range(struct clk_hw
*hw
, unsigned long min_rate
,
494 unsigned long max_rate
)
496 hw
->core
->min_rate
= min_rate
;
497 hw
->core
->max_rate
= max_rate
;
499 EXPORT_SYMBOL_GPL(clk_hw_set_rate_range
);
502 * Helper for finding best parent to provide a given frequency. This can be used
503 * directly as a determine_rate callback (e.g. for a mux), or from a more
504 * complex clock that may combine a mux with other operations.
506 int __clk_mux_determine_rate(struct clk_hw
*hw
,
507 struct clk_rate_request
*req
)
509 return clk_mux_determine_rate_flags(hw
, req
, 0);
511 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate
);
513 int __clk_mux_determine_rate_closest(struct clk_hw
*hw
,
514 struct clk_rate_request
*req
)
516 return clk_mux_determine_rate_flags(hw
, req
, CLK_MUX_ROUND_CLOSEST
);
518 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest
);
522 static void clk_core_unprepare(struct clk_core
*core
)
524 lockdep_assert_held(&prepare_lock
);
529 if (WARN_ON(core
->prepare_count
== 0))
532 if (WARN_ON(core
->prepare_count
== 1 && core
->flags
& CLK_IS_CRITICAL
))
535 if (--core
->prepare_count
> 0)
538 WARN_ON(core
->enable_count
> 0);
540 trace_clk_unprepare(core
);
542 if (core
->ops
->unprepare
)
543 core
->ops
->unprepare(core
->hw
);
545 clk_pm_runtime_put(core
);
547 trace_clk_unprepare_complete(core
);
548 clk_core_unprepare(core
->parent
);
551 static void clk_core_unprepare_lock(struct clk_core
*core
)
554 clk_core_unprepare(core
);
555 clk_prepare_unlock();
559 * clk_unprepare - undo preparation of a clock source
560 * @clk: the clk being unprepared
562 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
563 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
564 * if the operation may sleep. One example is a clk which is accessed over
565 * I2c. In the complex case a clk gate operation may require a fast and a slow
566 * part. It is this reason that clk_unprepare and clk_disable are not mutually
567 * exclusive. In fact clk_disable must be called before clk_unprepare.
569 void clk_unprepare(struct clk
*clk
)
571 if (IS_ERR_OR_NULL(clk
))
574 clk_core_unprepare_lock(clk
->core
);
576 EXPORT_SYMBOL_GPL(clk_unprepare
);
578 static int clk_core_prepare(struct clk_core
*core
)
582 lockdep_assert_held(&prepare_lock
);
587 if (core
->prepare_count
== 0) {
588 ret
= clk_pm_runtime_get(core
);
592 ret
= clk_core_prepare(core
->parent
);
596 trace_clk_prepare(core
);
598 if (core
->ops
->prepare
)
599 ret
= core
->ops
->prepare(core
->hw
);
601 trace_clk_prepare_complete(core
);
607 core
->prepare_count
++;
611 clk_core_unprepare(core
->parent
);
613 clk_pm_runtime_put(core
);
617 static int clk_core_prepare_lock(struct clk_core
*core
)
622 ret
= clk_core_prepare(core
);
623 clk_prepare_unlock();
629 * clk_prepare - prepare a clock source
630 * @clk: the clk being prepared
632 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
633 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
634 * operation may sleep. One example is a clk which is accessed over I2c. In
635 * the complex case a clk ungate operation may require a fast and a slow part.
636 * It is this reason that clk_prepare and clk_enable are not mutually
637 * exclusive. In fact clk_prepare must be called before clk_enable.
638 * Returns 0 on success, -EERROR otherwise.
640 int clk_prepare(struct clk
*clk
)
645 return clk_core_prepare_lock(clk
->core
);
647 EXPORT_SYMBOL_GPL(clk_prepare
);
649 static void clk_core_disable(struct clk_core
*core
)
651 lockdep_assert_held(&enable_lock
);
656 if (WARN_ON(core
->enable_count
== 0))
659 if (WARN_ON(core
->enable_count
== 1 && core
->flags
& CLK_IS_CRITICAL
))
662 if (--core
->enable_count
> 0)
665 trace_clk_disable_rcuidle(core
);
667 if (core
->ops
->disable
)
668 core
->ops
->disable(core
->hw
);
670 trace_clk_disable_complete_rcuidle(core
);
672 clk_core_disable(core
->parent
);
675 static void clk_core_disable_lock(struct clk_core
*core
)
679 flags
= clk_enable_lock();
680 clk_core_disable(core
);
681 clk_enable_unlock(flags
);
685 * clk_disable - gate a clock
686 * @clk: the clk being gated
688 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
689 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
690 * clk if the operation is fast and will never sleep. One example is a
691 * SoC-internal clk which is controlled via simple register writes. In the
692 * complex case a clk gate operation may require a fast and a slow part. It is
693 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
694 * In fact clk_disable must be called before clk_unprepare.
696 void clk_disable(struct clk
*clk
)
698 if (IS_ERR_OR_NULL(clk
))
701 clk_core_disable_lock(clk
->core
);
703 EXPORT_SYMBOL_GPL(clk_disable
);
705 static int clk_core_enable(struct clk_core
*core
)
709 lockdep_assert_held(&enable_lock
);
714 if (WARN_ON(core
->prepare_count
== 0))
717 if (core
->enable_count
== 0) {
718 ret
= clk_core_enable(core
->parent
);
723 trace_clk_enable_rcuidle(core
);
725 if (core
->ops
->enable
)
726 ret
= core
->ops
->enable(core
->hw
);
728 trace_clk_enable_complete_rcuidle(core
);
731 clk_core_disable(core
->parent
);
736 core
->enable_count
++;
740 static int clk_core_enable_lock(struct clk_core
*core
)
745 flags
= clk_enable_lock();
746 ret
= clk_core_enable(core
);
747 clk_enable_unlock(flags
);
753 * clk_enable - ungate a clock
754 * @clk: the clk being ungated
756 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
757 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
758 * if the operation will never sleep. One example is a SoC-internal clk which
759 * is controlled via simple register writes. In the complex case a clk ungate
760 * operation may require a fast and a slow part. It is this reason that
761 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
762 * must be called before clk_enable. Returns 0 on success, -EERROR
765 int clk_enable(struct clk
*clk
)
770 return clk_core_enable_lock(clk
->core
);
772 EXPORT_SYMBOL_GPL(clk_enable
);
774 static int clk_core_prepare_enable(struct clk_core
*core
)
778 ret
= clk_core_prepare_lock(core
);
782 ret
= clk_core_enable_lock(core
);
784 clk_core_unprepare_lock(core
);
789 static void clk_core_disable_unprepare(struct clk_core
*core
)
791 clk_core_disable_lock(core
);
792 clk_core_unprepare_lock(core
);
795 static void clk_unprepare_unused_subtree(struct clk_core
*core
)
797 struct clk_core
*child
;
799 lockdep_assert_held(&prepare_lock
);
801 hlist_for_each_entry(child
, &core
->children
, child_node
)
802 clk_unprepare_unused_subtree(child
);
804 if (core
->prepare_count
)
807 if (core
->flags
& CLK_IGNORE_UNUSED
)
810 if (clk_pm_runtime_get(core
))
813 if (clk_core_is_prepared(core
)) {
814 trace_clk_unprepare(core
);
815 if (core
->ops
->unprepare_unused
)
816 core
->ops
->unprepare_unused(core
->hw
);
817 else if (core
->ops
->unprepare
)
818 core
->ops
->unprepare(core
->hw
);
819 trace_clk_unprepare_complete(core
);
822 clk_pm_runtime_put(core
);
825 static void clk_disable_unused_subtree(struct clk_core
*core
)
827 struct clk_core
*child
;
830 lockdep_assert_held(&prepare_lock
);
832 hlist_for_each_entry(child
, &core
->children
, child_node
)
833 clk_disable_unused_subtree(child
);
835 if (core
->flags
& CLK_OPS_PARENT_ENABLE
)
836 clk_core_prepare_enable(core
->parent
);
838 if (clk_pm_runtime_get(core
))
841 flags
= clk_enable_lock();
843 if (core
->enable_count
)
846 if (core
->flags
& CLK_IGNORE_UNUSED
)
850 * some gate clocks have special needs during the disable-unused
851 * sequence. call .disable_unused if available, otherwise fall
854 if (clk_core_is_enabled(core
)) {
855 trace_clk_disable(core
);
856 if (core
->ops
->disable_unused
)
857 core
->ops
->disable_unused(core
->hw
);
858 else if (core
->ops
->disable
)
859 core
->ops
->disable(core
->hw
);
860 trace_clk_disable_complete(core
);
864 clk_enable_unlock(flags
);
865 clk_pm_runtime_put(core
);
867 if (core
->flags
& CLK_OPS_PARENT_ENABLE
)
868 clk_core_disable_unprepare(core
->parent
);
871 static bool clk_ignore_unused
;
872 static int __init
clk_ignore_unused_setup(char *__unused
)
874 clk_ignore_unused
= true;
877 __setup("clk_ignore_unused", clk_ignore_unused_setup
);
879 static int clk_disable_unused(void)
881 struct clk_core
*core
;
883 if (clk_ignore_unused
) {
884 pr_warn("clk: Not disabling unused clocks\n");
890 hlist_for_each_entry(core
, &clk_root_list
, child_node
)
891 clk_disable_unused_subtree(core
);
893 hlist_for_each_entry(core
, &clk_orphan_list
, child_node
)
894 clk_disable_unused_subtree(core
);
896 hlist_for_each_entry(core
, &clk_root_list
, child_node
)
897 clk_unprepare_unused_subtree(core
);
899 hlist_for_each_entry(core
, &clk_orphan_list
, child_node
)
900 clk_unprepare_unused_subtree(core
);
902 clk_prepare_unlock();
906 late_initcall_sync(clk_disable_unused
);
908 static int clk_core_round_rate_nolock(struct clk_core
*core
,
909 struct clk_rate_request
*req
)
911 struct clk_core
*parent
;
914 lockdep_assert_held(&prepare_lock
);
919 parent
= core
->parent
;
921 req
->best_parent_hw
= parent
->hw
;
922 req
->best_parent_rate
= parent
->rate
;
924 req
->best_parent_hw
= NULL
;
925 req
->best_parent_rate
= 0;
928 if (core
->ops
->determine_rate
) {
929 return core
->ops
->determine_rate(core
->hw
, req
);
930 } else if (core
->ops
->round_rate
) {
931 rate
= core
->ops
->round_rate(core
->hw
, req
->rate
,
932 &req
->best_parent_rate
);
937 } else if (core
->flags
& CLK_SET_RATE_PARENT
) {
938 return clk_core_round_rate_nolock(parent
, req
);
940 req
->rate
= core
->rate
;
947 * __clk_determine_rate - get the closest rate actually supported by a clock
948 * @hw: determine the rate of this clock
949 * @req: target rate request
951 * Useful for clk_ops such as .set_rate and .determine_rate.
953 int __clk_determine_rate(struct clk_hw
*hw
, struct clk_rate_request
*req
)
960 return clk_core_round_rate_nolock(hw
->core
, req
);
962 EXPORT_SYMBOL_GPL(__clk_determine_rate
);
964 unsigned long clk_hw_round_rate(struct clk_hw
*hw
, unsigned long rate
)
967 struct clk_rate_request req
;
969 clk_core_get_boundaries(hw
->core
, &req
.min_rate
, &req
.max_rate
);
972 ret
= clk_core_round_rate_nolock(hw
->core
, &req
);
978 EXPORT_SYMBOL_GPL(clk_hw_round_rate
);
981 * clk_round_rate - round the given rate for a clk
982 * @clk: the clk for which we are rounding a rate
983 * @rate: the rate which is to be rounded
985 * Takes in a rate as input and rounds it to a rate that the clk can actually
986 * use which is then returned. If clk doesn't support round_rate operation
987 * then the parent rate is returned.
989 long clk_round_rate(struct clk
*clk
, unsigned long rate
)
991 struct clk_rate_request req
;
999 clk_core_get_boundaries(clk
->core
, &req
.min_rate
, &req
.max_rate
);
1002 ret
= clk_core_round_rate_nolock(clk
->core
, &req
);
1003 clk_prepare_unlock();
1010 EXPORT_SYMBOL_GPL(clk_round_rate
);
1013 * __clk_notify - call clk notifier chain
1014 * @core: clk that is changing rate
1015 * @msg: clk notifier type (see include/linux/clk.h)
1016 * @old_rate: old clk rate
1017 * @new_rate: new clk rate
1019 * Triggers a notifier call chain on the clk rate-change notification
1020 * for 'clk'. Passes a pointer to the struct clk and the previous
1021 * and current rates to the notifier callback. Intended to be called by
1022 * internal clock code only. Returns NOTIFY_DONE from the last driver
1023 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1024 * a driver returns that.
1026 static int __clk_notify(struct clk_core
*core
, unsigned long msg
,
1027 unsigned long old_rate
, unsigned long new_rate
)
1029 struct clk_notifier
*cn
;
1030 struct clk_notifier_data cnd
;
1031 int ret
= NOTIFY_DONE
;
1033 cnd
.old_rate
= old_rate
;
1034 cnd
.new_rate
= new_rate
;
1036 list_for_each_entry(cn
, &clk_notifier_list
, node
) {
1037 if (cn
->clk
->core
== core
) {
1039 ret
= srcu_notifier_call_chain(&cn
->notifier_head
, msg
,
1041 if (ret
& NOTIFY_STOP_MASK
)
1050 * __clk_recalc_accuracies
1051 * @core: first clk in the subtree
1053 * Walks the subtree of clks starting with clk and recalculates accuracies as
1054 * it goes. Note that if a clk does not implement the .recalc_accuracy
1055 * callback then it is assumed that the clock will take on the accuracy of its
1058 static void __clk_recalc_accuracies(struct clk_core
*core
)
1060 unsigned long parent_accuracy
= 0;
1061 struct clk_core
*child
;
1063 lockdep_assert_held(&prepare_lock
);
1066 parent_accuracy
= core
->parent
->accuracy
;
1068 if (core
->ops
->recalc_accuracy
)
1069 core
->accuracy
= core
->ops
->recalc_accuracy(core
->hw
,
1072 core
->accuracy
= parent_accuracy
;
1074 hlist_for_each_entry(child
, &core
->children
, child_node
)
1075 __clk_recalc_accuracies(child
);
1078 static long clk_core_get_accuracy(struct clk_core
*core
)
1080 unsigned long accuracy
;
1083 if (core
&& (core
->flags
& CLK_GET_ACCURACY_NOCACHE
))
1084 __clk_recalc_accuracies(core
);
1086 accuracy
= __clk_get_accuracy(core
);
1087 clk_prepare_unlock();
1093 * clk_get_accuracy - return the accuracy of clk
1094 * @clk: the clk whose accuracy is being returned
1096 * Simply returns the cached accuracy of the clk, unless
1097 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1099 * If clk is NULL then returns 0.
1101 long clk_get_accuracy(struct clk
*clk
)
1106 return clk_core_get_accuracy(clk
->core
);
1108 EXPORT_SYMBOL_GPL(clk_get_accuracy
);
1110 static unsigned long clk_recalc(struct clk_core
*core
,
1111 unsigned long parent_rate
)
1113 unsigned long rate
= parent_rate
;
1115 if (core
->ops
->recalc_rate
&& !clk_pm_runtime_get(core
)) {
1116 rate
= core
->ops
->recalc_rate(core
->hw
, parent_rate
);
1117 clk_pm_runtime_put(core
);
1123 * __clk_recalc_rates
1124 * @core: first clk in the subtree
1125 * @msg: notification type (see include/linux/clk.h)
1127 * Walks the subtree of clks starting with clk and recalculates rates as it
1128 * goes. Note that if a clk does not implement the .recalc_rate callback then
1129 * it is assumed that the clock will take on the rate of its parent.
1131 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1134 static void __clk_recalc_rates(struct clk_core
*core
, unsigned long msg
)
1136 unsigned long old_rate
;
1137 unsigned long parent_rate
= 0;
1138 struct clk_core
*child
;
1140 lockdep_assert_held(&prepare_lock
);
1142 old_rate
= core
->rate
;
1145 parent_rate
= core
->parent
->rate
;
1147 core
->rate
= clk_recalc(core
, parent_rate
);
1150 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1151 * & ABORT_RATE_CHANGE notifiers
1153 if (core
->notifier_count
&& msg
)
1154 __clk_notify(core
, msg
, old_rate
, core
->rate
);
1156 hlist_for_each_entry(child
, &core
->children
, child_node
)
1157 __clk_recalc_rates(child
, msg
);
1160 static unsigned long clk_core_get_rate(struct clk_core
*core
)
1166 if (core
&& (core
->flags
& CLK_GET_RATE_NOCACHE
))
1167 __clk_recalc_rates(core
, 0);
1169 rate
= clk_core_get_rate_nolock(core
);
1170 clk_prepare_unlock();
1176 * clk_get_rate - return the rate of clk
1177 * @clk: the clk whose rate is being returned
1179 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1180 * is set, which means a recalc_rate will be issued.
1181 * If clk is NULL then returns 0.
1183 unsigned long clk_get_rate(struct clk
*clk
)
1188 return clk_core_get_rate(clk
->core
);
1190 EXPORT_SYMBOL_GPL(clk_get_rate
);
1192 static int clk_fetch_parent_index(struct clk_core
*core
,
1193 struct clk_core
*parent
)
1200 for (i
= 0; i
< core
->num_parents
; i
++)
1201 if (clk_core_get_parent_by_index(core
, i
) == parent
)
1208 * Update the orphan status of @core and all its children.
1210 static void clk_core_update_orphan_status(struct clk_core
*core
, bool is_orphan
)
1212 struct clk_core
*child
;
1214 core
->orphan
= is_orphan
;
1216 hlist_for_each_entry(child
, &core
->children
, child_node
)
1217 clk_core_update_orphan_status(child
, is_orphan
);
1220 static void clk_reparent(struct clk_core
*core
, struct clk_core
*new_parent
)
1222 bool was_orphan
= core
->orphan
;
1224 hlist_del(&core
->child_node
);
1227 bool becomes_orphan
= new_parent
->orphan
;
1229 /* avoid duplicate POST_RATE_CHANGE notifications */
1230 if (new_parent
->new_child
== core
)
1231 new_parent
->new_child
= NULL
;
1233 hlist_add_head(&core
->child_node
, &new_parent
->children
);
1235 if (was_orphan
!= becomes_orphan
)
1236 clk_core_update_orphan_status(core
, becomes_orphan
);
1238 hlist_add_head(&core
->child_node
, &clk_orphan_list
);
1240 clk_core_update_orphan_status(core
, true);
1243 core
->parent
= new_parent
;
1246 static struct clk_core
*__clk_set_parent_before(struct clk_core
*core
,
1247 struct clk_core
*parent
)
1249 unsigned long flags
;
1250 struct clk_core
*old_parent
= core
->parent
;
1253 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
1255 * 2. Migrate prepare state between parents and prevent race with
1258 * If the clock is not prepared, then a race with
1259 * clk_enable/disable() is impossible since we already have the
1260 * prepare lock (future calls to clk_enable() need to be preceded by
1263 * If the clock is prepared, migrate the prepared state to the new
1264 * parent and also protect against a race with clk_enable() by
1265 * forcing the clock and the new parent on. This ensures that all
1266 * future calls to clk_enable() are practically NOPs with respect to
1267 * hardware and software states.
1269 * See also: Comment for clk_set_parent() below.
1272 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
1273 if (core
->flags
& CLK_OPS_PARENT_ENABLE
) {
1274 clk_core_prepare_enable(old_parent
);
1275 clk_core_prepare_enable(parent
);
1278 /* migrate prepare count if > 0 */
1279 if (core
->prepare_count
) {
1280 clk_core_prepare_enable(parent
);
1281 clk_core_enable_lock(core
);
1284 /* update the clk tree topology */
1285 flags
= clk_enable_lock();
1286 clk_reparent(core
, parent
);
1287 clk_enable_unlock(flags
);
1292 static void __clk_set_parent_after(struct clk_core
*core
,
1293 struct clk_core
*parent
,
1294 struct clk_core
*old_parent
)
1297 * Finish the migration of prepare state and undo the changes done
1298 * for preventing a race with clk_enable().
1300 if (core
->prepare_count
) {
1301 clk_core_disable_lock(core
);
1302 clk_core_disable_unprepare(old_parent
);
1305 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
1306 if (core
->flags
& CLK_OPS_PARENT_ENABLE
) {
1307 clk_core_disable_unprepare(parent
);
1308 clk_core_disable_unprepare(old_parent
);
1312 static int __clk_set_parent(struct clk_core
*core
, struct clk_core
*parent
,
1315 unsigned long flags
;
1317 struct clk_core
*old_parent
;
1319 old_parent
= __clk_set_parent_before(core
, parent
);
1321 trace_clk_set_parent(core
, parent
);
1323 /* change clock input source */
1324 if (parent
&& core
->ops
->set_parent
)
1325 ret
= core
->ops
->set_parent(core
->hw
, p_index
);
1327 trace_clk_set_parent_complete(core
, parent
);
1330 flags
= clk_enable_lock();
1331 clk_reparent(core
, old_parent
);
1332 clk_enable_unlock(flags
);
1333 __clk_set_parent_after(core
, old_parent
, parent
);
1338 __clk_set_parent_after(core
, parent
, old_parent
);
1344 * __clk_speculate_rates
1345 * @core: first clk in the subtree
1346 * @parent_rate: the "future" rate of clk's parent
1348 * Walks the subtree of clks starting with clk, speculating rates as it
1349 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1351 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1352 * pre-rate change notifications and returns early if no clks in the
1353 * subtree have subscribed to the notifications. Note that if a clk does not
1354 * implement the .recalc_rate callback then it is assumed that the clock will
1355 * take on the rate of its parent.
1357 static int __clk_speculate_rates(struct clk_core
*core
,
1358 unsigned long parent_rate
)
1360 struct clk_core
*child
;
1361 unsigned long new_rate
;
1362 int ret
= NOTIFY_DONE
;
1364 lockdep_assert_held(&prepare_lock
);
1366 new_rate
= clk_recalc(core
, parent_rate
);
1368 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1369 if (core
->notifier_count
)
1370 ret
= __clk_notify(core
, PRE_RATE_CHANGE
, core
->rate
, new_rate
);
1372 if (ret
& NOTIFY_STOP_MASK
) {
1373 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1374 __func__
, core
->name
, ret
);
1378 hlist_for_each_entry(child
, &core
->children
, child_node
) {
1379 ret
= __clk_speculate_rates(child
, new_rate
);
1380 if (ret
& NOTIFY_STOP_MASK
)
1388 static void clk_calc_subtree(struct clk_core
*core
, unsigned long new_rate
,
1389 struct clk_core
*new_parent
, u8 p_index
)
1391 struct clk_core
*child
;
1393 core
->new_rate
= new_rate
;
1394 core
->new_parent
= new_parent
;
1395 core
->new_parent_index
= p_index
;
1396 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1397 core
->new_child
= NULL
;
1398 if (new_parent
&& new_parent
!= core
->parent
)
1399 new_parent
->new_child
= core
;
1401 hlist_for_each_entry(child
, &core
->children
, child_node
) {
1402 child
->new_rate
= clk_recalc(child
, new_rate
);
1403 clk_calc_subtree(child
, child
->new_rate
, NULL
, 0);
1408 * calculate the new rates returning the topmost clock that has to be
1411 static struct clk_core
*clk_calc_new_rates(struct clk_core
*core
,
1414 struct clk_core
*top
= core
;
1415 struct clk_core
*old_parent
, *parent
;
1416 unsigned long best_parent_rate
= 0;
1417 unsigned long new_rate
;
1418 unsigned long min_rate
;
1419 unsigned long max_rate
;
1424 if (IS_ERR_OR_NULL(core
))
1427 /* save parent rate, if it exists */
1428 parent
= old_parent
= core
->parent
;
1430 best_parent_rate
= parent
->rate
;
1432 clk_core_get_boundaries(core
, &min_rate
, &max_rate
);
1434 /* find the closest rate and parent clk/rate */
1435 if (core
->ops
->determine_rate
) {
1436 struct clk_rate_request req
;
1439 req
.min_rate
= min_rate
;
1440 req
.max_rate
= max_rate
;
1442 req
.best_parent_hw
= parent
->hw
;
1443 req
.best_parent_rate
= parent
->rate
;
1445 req
.best_parent_hw
= NULL
;
1446 req
.best_parent_rate
= 0;
1449 ret
= core
->ops
->determine_rate(core
->hw
, &req
);
1453 best_parent_rate
= req
.best_parent_rate
;
1454 new_rate
= req
.rate
;
1455 parent
= req
.best_parent_hw
? req
.best_parent_hw
->core
: NULL
;
1456 } else if (core
->ops
->round_rate
) {
1457 ret
= core
->ops
->round_rate(core
->hw
, rate
,
1463 if (new_rate
< min_rate
|| new_rate
> max_rate
)
1465 } else if (!parent
|| !(core
->flags
& CLK_SET_RATE_PARENT
)) {
1466 /* pass-through clock without adjustable parent */
1467 core
->new_rate
= core
->rate
;
1470 /* pass-through clock with adjustable parent */
1471 top
= clk_calc_new_rates(parent
, rate
);
1472 new_rate
= parent
->new_rate
;
1476 /* some clocks must be gated to change parent */
1477 if (parent
!= old_parent
&&
1478 (core
->flags
& CLK_SET_PARENT_GATE
) && core
->prepare_count
) {
1479 pr_debug("%s: %s not gated but wants to reparent\n",
1480 __func__
, core
->name
);
1484 /* try finding the new parent index */
1485 if (parent
&& core
->num_parents
> 1) {
1486 p_index
= clk_fetch_parent_index(core
, parent
);
1488 pr_debug("%s: clk %s can not be parent of clk %s\n",
1489 __func__
, parent
->name
, core
->name
);
1494 if ((core
->flags
& CLK_SET_RATE_PARENT
) && parent
&&
1495 best_parent_rate
!= parent
->rate
)
1496 top
= clk_calc_new_rates(parent
, best_parent_rate
);
1499 clk_calc_subtree(core
, new_rate
, parent
, p_index
);
1505 * Notify about rate changes in a subtree. Always walk down the whole tree
1506 * so that in case of an error we can walk down the whole tree again and
1509 static struct clk_core
*clk_propagate_rate_change(struct clk_core
*core
,
1510 unsigned long event
)
1512 struct clk_core
*child
, *tmp_clk
, *fail_clk
= NULL
;
1513 int ret
= NOTIFY_DONE
;
1515 if (core
->rate
== core
->new_rate
)
1518 if (core
->notifier_count
) {
1519 ret
= __clk_notify(core
, event
, core
->rate
, core
->new_rate
);
1520 if (ret
& NOTIFY_STOP_MASK
)
1524 hlist_for_each_entry(child
, &core
->children
, child_node
) {
1525 /* Skip children who will be reparented to another clock */
1526 if (child
->new_parent
&& child
->new_parent
!= core
)
1528 tmp_clk
= clk_propagate_rate_change(child
, event
);
1533 /* handle the new child who might not be in core->children yet */
1534 if (core
->new_child
) {
1535 tmp_clk
= clk_propagate_rate_change(core
->new_child
, event
);
1544 * walk down a subtree and set the new rates notifying the rate
1547 static void clk_change_rate(struct clk_core
*core
)
1549 struct clk_core
*child
;
1550 struct hlist_node
*tmp
;
1551 unsigned long old_rate
;
1552 unsigned long best_parent_rate
= 0;
1553 bool skip_set_rate
= false;
1554 struct clk_core
*old_parent
;
1555 struct clk_core
*parent
= NULL
;
1557 old_rate
= core
->rate
;
1559 if (core
->new_parent
) {
1560 parent
= core
->new_parent
;
1561 best_parent_rate
= core
->new_parent
->rate
;
1562 } else if (core
->parent
) {
1563 parent
= core
->parent
;
1564 best_parent_rate
= core
->parent
->rate
;
1567 if (core
->flags
& CLK_SET_RATE_UNGATE
) {
1568 unsigned long flags
;
1570 clk_core_prepare(core
);
1571 flags
= clk_enable_lock();
1572 clk_core_enable(core
);
1573 clk_enable_unlock(flags
);
1576 if (core
->new_parent
&& core
->new_parent
!= core
->parent
) {
1577 old_parent
= __clk_set_parent_before(core
, core
->new_parent
);
1578 trace_clk_set_parent(core
, core
->new_parent
);
1580 if (core
->ops
->set_rate_and_parent
) {
1581 skip_set_rate
= true;
1582 core
->ops
->set_rate_and_parent(core
->hw
, core
->new_rate
,
1584 core
->new_parent_index
);
1585 } else if (core
->ops
->set_parent
) {
1586 core
->ops
->set_parent(core
->hw
, core
->new_parent_index
);
1589 trace_clk_set_parent_complete(core
, core
->new_parent
);
1590 __clk_set_parent_after(core
, core
->new_parent
, old_parent
);
1593 if (core
->flags
& CLK_OPS_PARENT_ENABLE
)
1594 clk_core_prepare_enable(parent
);
1596 trace_clk_set_rate(core
, core
->new_rate
);
1598 if (!skip_set_rate
&& core
->ops
->set_rate
)
1599 core
->ops
->set_rate(core
->hw
, core
->new_rate
, best_parent_rate
);
1601 trace_clk_set_rate_complete(core
, core
->new_rate
);
1603 core
->rate
= clk_recalc(core
, best_parent_rate
);
1605 if (core
->flags
& CLK_SET_RATE_UNGATE
) {
1606 unsigned long flags
;
1608 flags
= clk_enable_lock();
1609 clk_core_disable(core
);
1610 clk_enable_unlock(flags
);
1611 clk_core_unprepare(core
);
1614 if (core
->flags
& CLK_OPS_PARENT_ENABLE
)
1615 clk_core_disable_unprepare(parent
);
1617 if (core
->notifier_count
&& old_rate
!= core
->rate
)
1618 __clk_notify(core
, POST_RATE_CHANGE
, old_rate
, core
->rate
);
1620 if (core
->flags
& CLK_RECALC_NEW_RATES
)
1621 (void)clk_calc_new_rates(core
, core
->new_rate
);
1624 * Use safe iteration, as change_rate can actually swap parents
1625 * for certain clock types.
1627 hlist_for_each_entry_safe(child
, tmp
, &core
->children
, child_node
) {
1628 /* Skip children who will be reparented to another clock */
1629 if (child
->new_parent
&& child
->new_parent
!= core
)
1631 clk_change_rate(child
);
1634 /* handle the new child who might not be in core->children yet */
1635 if (core
->new_child
)
1636 clk_change_rate(core
->new_child
);
1639 static int clk_core_set_rate_nolock(struct clk_core
*core
,
1640 unsigned long req_rate
)
1642 struct clk_core
*top
, *fail_clk
;
1643 unsigned long rate
= req_rate
;
1649 /* bail early if nothing to do */
1650 if (rate
== clk_core_get_rate_nolock(core
))
1653 if ((core
->flags
& CLK_SET_RATE_GATE
) && core
->prepare_count
)
1656 /* calculate new rates and get the topmost changed clock */
1657 top
= clk_calc_new_rates(core
, rate
);
1661 ret
= clk_pm_runtime_get(core
);
1665 /* notify that we are about to change rates */
1666 fail_clk
= clk_propagate_rate_change(top
, PRE_RATE_CHANGE
);
1668 pr_debug("%s: failed to set %s rate\n", __func__
,
1670 clk_propagate_rate_change(top
, ABORT_RATE_CHANGE
);
1675 /* change the rates */
1676 clk_change_rate(top
);
1678 core
->req_rate
= req_rate
;
1680 clk_pm_runtime_put(core
);
1686 * clk_set_rate - specify a new rate for clk
1687 * @clk: the clk whose rate is being changed
1688 * @rate: the new rate for clk
1690 * In the simplest case clk_set_rate will only adjust the rate of clk.
1692 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1693 * propagate up to clk's parent; whether or not this happens depends on the
1694 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1695 * after calling .round_rate then upstream parent propagation is ignored. If
1696 * *parent_rate comes back with a new rate for clk's parent then we propagate
1697 * up to clk's parent and set its rate. Upward propagation will continue
1698 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1699 * .round_rate stops requesting changes to clk's parent_rate.
1701 * Rate changes are accomplished via tree traversal that also recalculates the
1702 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
1704 * Returns 0 on success, -EERROR otherwise.
1706 int clk_set_rate(struct clk
*clk
, unsigned long rate
)
1713 /* prevent racing with updates to the clock topology */
1716 ret
= clk_core_set_rate_nolock(clk
->core
, rate
);
1718 clk_prepare_unlock();
1722 EXPORT_SYMBOL_GPL(clk_set_rate
);
1725 * clk_set_rate_range - set a rate range for a clock source
1726 * @clk: clock source
1727 * @min: desired minimum clock rate in Hz, inclusive
1728 * @max: desired maximum clock rate in Hz, inclusive
1730 * Returns success (0) or negative errno.
1732 int clk_set_rate_range(struct clk
*clk
, unsigned long min
, unsigned long max
)
1740 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
1741 __func__
, clk
->core
->name
, clk
->dev_id
, clk
->con_id
,
1748 if (min
!= clk
->min_rate
|| max
!= clk
->max_rate
) {
1749 clk
->min_rate
= min
;
1750 clk
->max_rate
= max
;
1751 ret
= clk_core_set_rate_nolock(clk
->core
, clk
->core
->req_rate
);
1754 clk_prepare_unlock();
1758 EXPORT_SYMBOL_GPL(clk_set_rate_range
);
1761 * clk_set_min_rate - set a minimum clock rate for a clock source
1762 * @clk: clock source
1763 * @rate: desired minimum clock rate in Hz, inclusive
1765 * Returns success (0) or negative errno.
1767 int clk_set_min_rate(struct clk
*clk
, unsigned long rate
)
1772 return clk_set_rate_range(clk
, rate
, clk
->max_rate
);
1774 EXPORT_SYMBOL_GPL(clk_set_min_rate
);
1777 * clk_set_max_rate - set a maximum clock rate for a clock source
1778 * @clk: clock source
1779 * @rate: desired maximum clock rate in Hz, inclusive
1781 * Returns success (0) or negative errno.
1783 int clk_set_max_rate(struct clk
*clk
, unsigned long rate
)
1788 return clk_set_rate_range(clk
, clk
->min_rate
, rate
);
1790 EXPORT_SYMBOL_GPL(clk_set_max_rate
);
1793 * clk_get_parent - return the parent of a clk
1794 * @clk: the clk whose parent gets returned
1796 * Simply returns clk->parent. Returns NULL if clk is NULL.
1798 struct clk
*clk_get_parent(struct clk
*clk
)
1806 /* TODO: Create a per-user clk and change callers to call clk_put */
1807 parent
= !clk
->core
->parent
? NULL
: clk
->core
->parent
->hw
->clk
;
1808 clk_prepare_unlock();
1812 EXPORT_SYMBOL_GPL(clk_get_parent
);
1814 static struct clk_core
*__clk_init_parent(struct clk_core
*core
)
1818 if (core
->num_parents
> 1 && core
->ops
->get_parent
)
1819 index
= core
->ops
->get_parent(core
->hw
);
1821 return clk_core_get_parent_by_index(core
, index
);
1824 static void clk_core_reparent(struct clk_core
*core
,
1825 struct clk_core
*new_parent
)
1827 clk_reparent(core
, new_parent
);
1828 __clk_recalc_accuracies(core
);
1829 __clk_recalc_rates(core
, POST_RATE_CHANGE
);
1832 void clk_hw_reparent(struct clk_hw
*hw
, struct clk_hw
*new_parent
)
1837 clk_core_reparent(hw
->core
, !new_parent
? NULL
: new_parent
->core
);
1841 * clk_has_parent - check if a clock is a possible parent for another
1842 * @clk: clock source
1843 * @parent: parent clock source
1845 * This function can be used in drivers that need to check that a clock can be
1846 * the parent of another without actually changing the parent.
1848 * Returns true if @parent is a possible parent for @clk, false otherwise.
1850 bool clk_has_parent(struct clk
*clk
, struct clk
*parent
)
1852 struct clk_core
*core
, *parent_core
;
1855 /* NULL clocks should be nops, so return success if either is NULL. */
1856 if (!clk
|| !parent
)
1860 parent_core
= parent
->core
;
1862 /* Optimize for the case where the parent is already the parent. */
1863 if (core
->parent
== parent_core
)
1866 for (i
= 0; i
< core
->num_parents
; i
++)
1867 if (strcmp(core
->parent_names
[i
], parent_core
->name
) == 0)
1872 EXPORT_SYMBOL_GPL(clk_has_parent
);
1874 static int clk_core_set_parent(struct clk_core
*core
, struct clk_core
*parent
)
1878 unsigned long p_rate
= 0;
1883 /* prevent racing with updates to the clock topology */
1886 if (core
->parent
== parent
)
1889 /* verify ops for for multi-parent clks */
1890 if ((core
->num_parents
> 1) && (!core
->ops
->set_parent
)) {
1895 /* check that we are allowed to re-parent if the clock is in use */
1896 if ((core
->flags
& CLK_SET_PARENT_GATE
) && core
->prepare_count
) {
1901 /* try finding the new parent index */
1903 p_index
= clk_fetch_parent_index(core
, parent
);
1905 pr_debug("%s: clk %s can not be parent of clk %s\n",
1906 __func__
, parent
->name
, core
->name
);
1910 p_rate
= parent
->rate
;
1913 ret
= clk_pm_runtime_get(core
);
1917 /* propagate PRE_RATE_CHANGE notifications */
1918 ret
= __clk_speculate_rates(core
, p_rate
);
1920 /* abort if a driver objects */
1921 if (ret
& NOTIFY_STOP_MASK
)
1924 /* do the re-parent */
1925 ret
= __clk_set_parent(core
, parent
, p_index
);
1927 /* propagate rate an accuracy recalculation accordingly */
1929 __clk_recalc_rates(core
, ABORT_RATE_CHANGE
);
1931 __clk_recalc_rates(core
, POST_RATE_CHANGE
);
1932 __clk_recalc_accuracies(core
);
1936 clk_pm_runtime_put(core
);
1938 clk_prepare_unlock();
1944 * clk_set_parent - switch the parent of a mux clk
1945 * @clk: the mux clk whose input we are switching
1946 * @parent: the new input to clk
1948 * Re-parent clk to use parent as its new input source. If clk is in
1949 * prepared state, the clk will get enabled for the duration of this call. If
1950 * that's not acceptable for a specific clk (Eg: the consumer can't handle
1951 * that, the reparenting is glitchy in hardware, etc), use the
1952 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
1954 * After successfully changing clk's parent clk_set_parent will update the
1955 * clk topology, sysfs topology and propagate rate recalculation via
1956 * __clk_recalc_rates.
1958 * Returns 0 on success, -EERROR otherwise.
1960 int clk_set_parent(struct clk
*clk
, struct clk
*parent
)
1965 return clk_core_set_parent(clk
->core
, parent
? parent
->core
: NULL
);
1967 EXPORT_SYMBOL_GPL(clk_set_parent
);
1970 * clk_set_phase - adjust the phase shift of a clock signal
1971 * @clk: clock signal source
1972 * @degrees: number of degrees the signal is shifted
1974 * Shifts the phase of a clock signal by the specified
1975 * degrees. Returns 0 on success, -EERROR otherwise.
1977 * This function makes no distinction about the input or reference
1978 * signal that we adjust the clock signal phase against. For example
1979 * phase locked-loop clock signal generators we may shift phase with
1980 * respect to feedback clock signal input, but for other cases the
1981 * clock phase may be shifted with respect to some other, unspecified
1984 * Additionally the concept of phase shift does not propagate through
1985 * the clock tree hierarchy, which sets it apart from clock rates and
1986 * clock accuracy. A parent clock phase attribute does not have an
1987 * impact on the phase attribute of a child clock.
1989 int clk_set_phase(struct clk
*clk
, int degrees
)
1996 /* sanity check degrees */
2003 trace_clk_set_phase(clk
->core
, degrees
);
2005 if (clk
->core
->ops
->set_phase
)
2006 ret
= clk
->core
->ops
->set_phase(clk
->core
->hw
, degrees
);
2008 trace_clk_set_phase_complete(clk
->core
, degrees
);
2011 clk
->core
->phase
= degrees
;
2013 clk_prepare_unlock();
2017 EXPORT_SYMBOL_GPL(clk_set_phase
);
2019 static int clk_core_get_phase(struct clk_core
*core
)
2025 clk_prepare_unlock();
2031 * clk_get_phase - return the phase shift of a clock signal
2032 * @clk: clock signal source
2034 * Returns the phase shift of a clock node in degrees, otherwise returns
2037 int clk_get_phase(struct clk
*clk
)
2042 return clk_core_get_phase(clk
->core
);
2044 EXPORT_SYMBOL_GPL(clk_get_phase
);
2047 * clk_is_match - check if two clk's point to the same hardware clock
2048 * @p: clk compared against q
2049 * @q: clk compared against p
2051 * Returns true if the two struct clk pointers both point to the same hardware
2052 * clock node. Put differently, returns true if struct clk *p and struct clk *q
2053 * share the same struct clk_core object.
2055 * Returns false otherwise. Note that two NULL clks are treated as matching.
2057 bool clk_is_match(const struct clk
*p
, const struct clk
*q
)
2059 /* trivial case: identical struct clk's or both NULL */
2063 /* true if clk->core pointers match. Avoid dereferencing garbage */
2064 if (!IS_ERR_OR_NULL(p
) && !IS_ERR_OR_NULL(q
))
2065 if (p
->core
== q
->core
)
2070 EXPORT_SYMBOL_GPL(clk_is_match
);
2072 /*** debugfs support ***/
2074 #ifdef CONFIG_DEBUG_FS
2075 #include <linux/debugfs.h>
2077 static struct dentry
*rootdir
;
2078 static int inited
= 0;
2079 static DEFINE_MUTEX(clk_debug_lock
);
2080 static HLIST_HEAD(clk_debug_list
);
2082 static struct hlist_head
*all_lists
[] = {
2088 static struct hlist_head
*orphan_list
[] = {
2093 static void clk_summary_show_one(struct seq_file
*s
, struct clk_core
*c
,
2099 seq_printf(s
, "%*s%-*s %11d %12d %11lu %10lu %-3d\n",
2101 30 - level
* 3, c
->name
,
2102 c
->enable_count
, c
->prepare_count
, clk_core_get_rate(c
),
2103 clk_core_get_accuracy(c
), clk_core_get_phase(c
));
2106 static void clk_summary_show_subtree(struct seq_file
*s
, struct clk_core
*c
,
2109 struct clk_core
*child
;
2114 clk_summary_show_one(s
, c
, level
);
2116 hlist_for_each_entry(child
, &c
->children
, child_node
)
2117 clk_summary_show_subtree(s
, child
, level
+ 1);
2120 static int clk_summary_show(struct seq_file
*s
, void *data
)
2123 struct hlist_head
**lists
= (struct hlist_head
**)s
->private;
2125 seq_puts(s
, " clock enable_cnt prepare_cnt rate accuracy phase\n");
2126 seq_puts(s
, "----------------------------------------------------------------------------------------\n");
2130 for (; *lists
; lists
++)
2131 hlist_for_each_entry(c
, *lists
, child_node
)
2132 clk_summary_show_subtree(s
, c
, 0);
2134 clk_prepare_unlock();
2140 static int clk_summary_open(struct inode
*inode
, struct file
*file
)
2142 return single_open(file
, clk_summary_show
, inode
->i_private
);
2145 static const struct file_operations clk_summary_fops
= {
2146 .open
= clk_summary_open
,
2148 .llseek
= seq_lseek
,
2149 .release
= single_release
,
2152 static void clk_dump_one(struct seq_file
*s
, struct clk_core
*c
, int level
)
2157 /* This should be JSON format, i.e. elements separated with a comma */
2158 seq_printf(s
, "\"%s\": { ", c
->name
);
2159 seq_printf(s
, "\"enable_count\": %d,", c
->enable_count
);
2160 seq_printf(s
, "\"prepare_count\": %d,", c
->prepare_count
);
2161 seq_printf(s
, "\"rate\": %lu,", clk_core_get_rate(c
));
2162 seq_printf(s
, "\"accuracy\": %lu,", clk_core_get_accuracy(c
));
2163 seq_printf(s
, "\"phase\": %d", clk_core_get_phase(c
));
2166 static void clk_dump_subtree(struct seq_file
*s
, struct clk_core
*c
, int level
)
2168 struct clk_core
*child
;
2173 clk_dump_one(s
, c
, level
);
2175 hlist_for_each_entry(child
, &c
->children
, child_node
) {
2177 clk_dump_subtree(s
, child
, level
+ 1);
2183 static int clk_dump(struct seq_file
*s
, void *data
)
2186 bool first_node
= true;
2187 struct hlist_head
**lists
= (struct hlist_head
**)s
->private;
2192 for (; *lists
; lists
++) {
2193 hlist_for_each_entry(c
, *lists
, child_node
) {
2197 clk_dump_subtree(s
, c
, 0);
2201 clk_prepare_unlock();
2208 static int clk_dump_open(struct inode
*inode
, struct file
*file
)
2210 return single_open(file
, clk_dump
, inode
->i_private
);
2213 static const struct file_operations clk_dump_fops
= {
2214 .open
= clk_dump_open
,
2216 .llseek
= seq_lseek
,
2217 .release
= single_release
,
2220 static int possible_parents_dump(struct seq_file
*s
, void *data
)
2222 struct clk_core
*core
= s
->private;
2225 for (i
= 0; i
< core
->num_parents
- 1; i
++)
2226 seq_printf(s
, "%s ", core
->parent_names
[i
]);
2228 seq_printf(s
, "%s\n", core
->parent_names
[i
]);
2233 static int possible_parents_open(struct inode
*inode
, struct file
*file
)
2235 return single_open(file
, possible_parents_dump
, inode
->i_private
);
2238 static const struct file_operations possible_parents_fops
= {
2239 .open
= possible_parents_open
,
2241 .llseek
= seq_lseek
,
2242 .release
= single_release
,
2245 static int clk_debug_create_one(struct clk_core
*core
, struct dentry
*pdentry
)
2250 if (!core
|| !pdentry
) {
2255 d
= debugfs_create_dir(core
->name
, pdentry
);
2261 d
= debugfs_create_u32("clk_rate", S_IRUGO
, core
->dentry
,
2262 (u32
*)&core
->rate
);
2266 d
= debugfs_create_u32("clk_accuracy", S_IRUGO
, core
->dentry
,
2267 (u32
*)&core
->accuracy
);
2271 d
= debugfs_create_u32("clk_phase", S_IRUGO
, core
->dentry
,
2272 (u32
*)&core
->phase
);
2276 d
= debugfs_create_x32("clk_flags", S_IRUGO
, core
->dentry
,
2277 (u32
*)&core
->flags
);
2281 d
= debugfs_create_u32("clk_prepare_count", S_IRUGO
, core
->dentry
,
2282 (u32
*)&core
->prepare_count
);
2286 d
= debugfs_create_u32("clk_enable_count", S_IRUGO
, core
->dentry
,
2287 (u32
*)&core
->enable_count
);
2291 d
= debugfs_create_u32("clk_notifier_count", S_IRUGO
, core
->dentry
,
2292 (u32
*)&core
->notifier_count
);
2296 if (core
->num_parents
> 1) {
2297 d
= debugfs_create_file("clk_possible_parents", S_IRUGO
,
2298 core
->dentry
, core
, &possible_parents_fops
);
2303 if (core
->ops
->debug_init
) {
2304 ret
= core
->ops
->debug_init(core
->hw
, core
->dentry
);
2313 debugfs_remove_recursive(core
->dentry
);
2314 core
->dentry
= NULL
;
2320 * clk_debug_register - add a clk node to the debugfs clk directory
2321 * @core: the clk being added to the debugfs clk directory
2323 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
2324 * initialized. Otherwise it bails out early since the debugfs clk directory
2325 * will be created lazily by clk_debug_init as part of a late_initcall.
2327 static int clk_debug_register(struct clk_core
*core
)
2331 mutex_lock(&clk_debug_lock
);
2332 hlist_add_head(&core
->debug_node
, &clk_debug_list
);
2337 ret
= clk_debug_create_one(core
, rootdir
);
2339 mutex_unlock(&clk_debug_lock
);
2345 * clk_debug_unregister - remove a clk node from the debugfs clk directory
2346 * @core: the clk being removed from the debugfs clk directory
2348 * Dynamically removes a clk and all its child nodes from the
2349 * debugfs clk directory if clk->dentry points to debugfs created by
2350 * clk_debug_register in __clk_core_init.
2352 static void clk_debug_unregister(struct clk_core
*core
)
2354 mutex_lock(&clk_debug_lock
);
2355 hlist_del_init(&core
->debug_node
);
2356 debugfs_remove_recursive(core
->dentry
);
2357 core
->dentry
= NULL
;
2358 mutex_unlock(&clk_debug_lock
);
2361 struct dentry
*clk_debugfs_add_file(struct clk_hw
*hw
, char *name
, umode_t mode
,
2362 void *data
, const struct file_operations
*fops
)
2364 struct dentry
*d
= NULL
;
2366 if (hw
->core
->dentry
)
2367 d
= debugfs_create_file(name
, mode
, hw
->core
->dentry
, data
,
2372 EXPORT_SYMBOL_GPL(clk_debugfs_add_file
);
2375 * clk_debug_init - lazily populate the debugfs clk directory
2377 * clks are often initialized very early during boot before memory can be
2378 * dynamically allocated and well before debugfs is setup. This function
2379 * populates the debugfs clk directory once at boot-time when we know that
2380 * debugfs is setup. It should only be called once at boot-time, all other clks
2381 * added dynamically will be done so with clk_debug_register.
2383 static int __init
clk_debug_init(void)
2385 struct clk_core
*core
;
2388 rootdir
= debugfs_create_dir("clk", NULL
);
2393 d
= debugfs_create_file("clk_summary", S_IRUGO
, rootdir
, &all_lists
,
2398 d
= debugfs_create_file("clk_dump", S_IRUGO
, rootdir
, &all_lists
,
2403 d
= debugfs_create_file("clk_orphan_summary", S_IRUGO
, rootdir
,
2404 &orphan_list
, &clk_summary_fops
);
2408 d
= debugfs_create_file("clk_orphan_dump", S_IRUGO
, rootdir
,
2409 &orphan_list
, &clk_dump_fops
);
2413 mutex_lock(&clk_debug_lock
);
2414 hlist_for_each_entry(core
, &clk_debug_list
, debug_node
)
2415 clk_debug_create_one(core
, rootdir
);
2418 mutex_unlock(&clk_debug_lock
);
2422 late_initcall(clk_debug_init
);
2424 static inline int clk_debug_register(struct clk_core
*core
) { return 0; }
2425 static inline void clk_debug_reparent(struct clk_core
*core
,
2426 struct clk_core
*new_parent
)
2429 static inline void clk_debug_unregister(struct clk_core
*core
)
2435 * __clk_core_init - initialize the data structures in a struct clk_core
2436 * @core: clk_core being initialized
2438 * Initializes the lists in struct clk_core, queries the hardware for the
2439 * parent and rate and sets them both.
2441 static int __clk_core_init(struct clk_core
*core
)
2444 struct clk_core
*orphan
;
2445 struct hlist_node
*tmp2
;
2453 ret
= clk_pm_runtime_get(core
);
2457 /* check to see if a clock with this name is already registered */
2458 if (clk_core_lookup(core
->name
)) {
2459 pr_debug("%s: clk %s already initialized\n",
2460 __func__
, core
->name
);
2465 /* check that clk_ops are sane. See Documentation/clk.txt */
2466 if (core
->ops
->set_rate
&&
2467 !((core
->ops
->round_rate
|| core
->ops
->determine_rate
) &&
2468 core
->ops
->recalc_rate
)) {
2469 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
2470 __func__
, core
->name
);
2475 if (core
->ops
->set_parent
&& !core
->ops
->get_parent
) {
2476 pr_err("%s: %s must implement .get_parent & .set_parent\n",
2477 __func__
, core
->name
);
2482 if (core
->num_parents
> 1 && !core
->ops
->get_parent
) {
2483 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
2484 __func__
, core
->name
);
2489 if (core
->ops
->set_rate_and_parent
&&
2490 !(core
->ops
->set_parent
&& core
->ops
->set_rate
)) {
2491 pr_err("%s: %s must implement .set_parent & .set_rate\n",
2492 __func__
, core
->name
);
2497 /* throw a WARN if any entries in parent_names are NULL */
2498 for (i
= 0; i
< core
->num_parents
; i
++)
2499 WARN(!core
->parent_names
[i
],
2500 "%s: invalid NULL in %s's .parent_names\n",
2501 __func__
, core
->name
);
2503 core
->parent
= __clk_init_parent(core
);
2506 * Populate core->parent if parent has already been clk_core_init'd. If
2507 * parent has not yet been clk_core_init'd then place clk in the orphan
2508 * list. If clk doesn't have any parents then place it in the root
2511 * Every time a new clk is clk_init'd then we walk the list of orphan
2512 * clocks and re-parent any that are children of the clock currently
2516 hlist_add_head(&core
->child_node
,
2517 &core
->parent
->children
);
2518 core
->orphan
= core
->parent
->orphan
;
2519 } else if (!core
->num_parents
) {
2520 hlist_add_head(&core
->child_node
, &clk_root_list
);
2521 core
->orphan
= false;
2523 hlist_add_head(&core
->child_node
, &clk_orphan_list
);
2524 core
->orphan
= true;
2528 * Set clk's accuracy. The preferred method is to use
2529 * .recalc_accuracy. For simple clocks and lazy developers the default
2530 * fallback is to use the parent's accuracy. If a clock doesn't have a
2531 * parent (or is orphaned) then accuracy is set to zero (perfect
2534 if (core
->ops
->recalc_accuracy
)
2535 core
->accuracy
= core
->ops
->recalc_accuracy(core
->hw
,
2536 __clk_get_accuracy(core
->parent
));
2537 else if (core
->parent
)
2538 core
->accuracy
= core
->parent
->accuracy
;
2544 * Since a phase is by definition relative to its parent, just
2545 * query the current clock phase, or just assume it's in phase.
2547 if (core
->ops
->get_phase
)
2548 core
->phase
= core
->ops
->get_phase(core
->hw
);
2553 * Set clk's rate. The preferred method is to use .recalc_rate. For
2554 * simple clocks and lazy developers the default fallback is to use the
2555 * parent's rate. If a clock doesn't have a parent (or is orphaned)
2556 * then rate is set to zero.
2558 if (core
->ops
->recalc_rate
)
2559 rate
= core
->ops
->recalc_rate(core
->hw
,
2560 clk_core_get_rate_nolock(core
->parent
));
2561 else if (core
->parent
)
2562 rate
= core
->parent
->rate
;
2565 core
->rate
= core
->req_rate
= rate
;
2568 * walk the list of orphan clocks and reparent any that newly finds a
2571 hlist_for_each_entry_safe(orphan
, tmp2
, &clk_orphan_list
, child_node
) {
2572 struct clk_core
*parent
= __clk_init_parent(orphan
);
2575 * we could call __clk_set_parent, but that would result in a
2576 * redundant call to the .set_rate op, if it exists
2579 __clk_set_parent_before(orphan
, parent
);
2580 __clk_set_parent_after(orphan
, parent
, NULL
);
2581 __clk_recalc_accuracies(orphan
);
2582 __clk_recalc_rates(orphan
, 0);
2587 * optional platform-specific magic
2589 * The .init callback is not used by any of the basic clock types, but
2590 * exists for weird hardware that must perform initialization magic.
2591 * Please consider other ways of solving initialization problems before
2592 * using this callback, as its use is discouraged.
2594 if (core
->ops
->init
)
2595 core
->ops
->init(core
->hw
);
2597 if (core
->flags
& CLK_IS_CRITICAL
) {
2598 unsigned long flags
;
2600 clk_core_prepare(core
);
2602 flags
= clk_enable_lock();
2603 clk_core_enable(core
);
2604 clk_enable_unlock(flags
);
2607 kref_init(&core
->ref
);
2609 clk_pm_runtime_put(core
);
2611 clk_prepare_unlock();
2614 clk_debug_register(core
);
2619 struct clk
*__clk_create_clk(struct clk_hw
*hw
, const char *dev_id
,
2624 /* This is to allow this function to be chained to others */
2625 if (IS_ERR_OR_NULL(hw
))
2626 return ERR_CAST(hw
);
2628 clk
= kzalloc(sizeof(*clk
), GFP_KERNEL
);
2630 return ERR_PTR(-ENOMEM
);
2632 clk
->core
= hw
->core
;
2633 clk
->dev_id
= dev_id
;
2634 clk
->con_id
= kstrdup_const(con_id
, GFP_KERNEL
);
2635 clk
->max_rate
= ULONG_MAX
;
2638 hlist_add_head(&clk
->clks_node
, &hw
->core
->clks
);
2639 clk_prepare_unlock();
2644 void __clk_free_clk(struct clk
*clk
)
2647 hlist_del(&clk
->clks_node
);
2648 clk_prepare_unlock();
2650 kfree_const(clk
->con_id
);
2655 * clk_register - allocate a new clock, register it and return an opaque cookie
2656 * @dev: device that is registering this clock
2657 * @hw: link to hardware-specific clock data
2659 * clk_register is the primary interface for populating the clock tree with new
2660 * clock nodes. It returns a pointer to the newly allocated struct clk which
2661 * cannot be dereferenced by driver code but may be used in conjunction with the
2662 * rest of the clock API. In the event of an error clk_register will return an
2663 * error code; drivers must test for an error code after calling clk_register.
2665 struct clk
*clk_register(struct device
*dev
, struct clk_hw
*hw
)
2668 struct clk_core
*core
;
2670 core
= kzalloc(sizeof(*core
), GFP_KERNEL
);
2676 core
->name
= kstrdup_const(hw
->init
->name
, GFP_KERNEL
);
2681 core
->ops
= hw
->init
->ops
;
2682 if (dev
&& pm_runtime_enabled(dev
))
2684 if (dev
&& dev
->driver
)
2685 core
->owner
= dev
->driver
->owner
;
2687 core
->flags
= hw
->init
->flags
;
2688 core
->num_parents
= hw
->init
->num_parents
;
2690 core
->max_rate
= ULONG_MAX
;
2693 /* allocate local copy in case parent_names is __initdata */
2694 core
->parent_names
= kcalloc(core
->num_parents
, sizeof(char *),
2697 if (!core
->parent_names
) {
2699 goto fail_parent_names
;
2703 /* copy each string name in case parent_names is __initdata */
2704 for (i
= 0; i
< core
->num_parents
; i
++) {
2705 core
->parent_names
[i
] = kstrdup_const(hw
->init
->parent_names
[i
],
2707 if (!core
->parent_names
[i
]) {
2709 goto fail_parent_names_copy
;
2713 /* avoid unnecessary string look-ups of clk_core's possible parents. */
2714 core
->parents
= kcalloc(core
->num_parents
, sizeof(*core
->parents
),
2716 if (!core
->parents
) {
2721 INIT_HLIST_HEAD(&core
->clks
);
2723 hw
->clk
= __clk_create_clk(hw
, NULL
, NULL
);
2724 if (IS_ERR(hw
->clk
)) {
2725 ret
= PTR_ERR(hw
->clk
);
2729 ret
= __clk_core_init(core
);
2733 __clk_free_clk(hw
->clk
);
2737 kfree(core
->parents
);
2738 fail_parent_names_copy
:
2740 kfree_const(core
->parent_names
[i
]);
2741 kfree(core
->parent_names
);
2743 kfree_const(core
->name
);
2747 return ERR_PTR(ret
);
2749 EXPORT_SYMBOL_GPL(clk_register
);
2752 * clk_hw_register - register a clk_hw and return an error code
2753 * @dev: device that is registering this clock
2754 * @hw: link to hardware-specific clock data
2756 * clk_hw_register is the primary interface for populating the clock tree with
2757 * new clock nodes. It returns an integer equal to zero indicating success or
2758 * less than zero indicating failure. Drivers must test for an error code after
2759 * calling clk_hw_register().
2761 int clk_hw_register(struct device
*dev
, struct clk_hw
*hw
)
2763 return PTR_ERR_OR_ZERO(clk_register(dev
, hw
));
2765 EXPORT_SYMBOL_GPL(clk_hw_register
);
2767 /* Free memory allocated for a clock. */
2768 static void __clk_release(struct kref
*ref
)
2770 struct clk_core
*core
= container_of(ref
, struct clk_core
, ref
);
2771 int i
= core
->num_parents
;
2773 lockdep_assert_held(&prepare_lock
);
2775 kfree(core
->parents
);
2777 kfree_const(core
->parent_names
[i
]);
2779 kfree(core
->parent_names
);
2780 kfree_const(core
->name
);
2785 * Empty clk_ops for unregistered clocks. These are used temporarily
2786 * after clk_unregister() was called on a clock and until last clock
2787 * consumer calls clk_put() and the struct clk object is freed.
2789 static int clk_nodrv_prepare_enable(struct clk_hw
*hw
)
2794 static void clk_nodrv_disable_unprepare(struct clk_hw
*hw
)
2799 static int clk_nodrv_set_rate(struct clk_hw
*hw
, unsigned long rate
,
2800 unsigned long parent_rate
)
2805 static int clk_nodrv_set_parent(struct clk_hw
*hw
, u8 index
)
2810 static const struct clk_ops clk_nodrv_ops
= {
2811 .enable
= clk_nodrv_prepare_enable
,
2812 .disable
= clk_nodrv_disable_unprepare
,
2813 .prepare
= clk_nodrv_prepare_enable
,
2814 .unprepare
= clk_nodrv_disable_unprepare
,
2815 .set_rate
= clk_nodrv_set_rate
,
2816 .set_parent
= clk_nodrv_set_parent
,
2820 * clk_unregister - unregister a currently registered clock
2821 * @clk: clock to unregister
2823 void clk_unregister(struct clk
*clk
)
2825 unsigned long flags
;
2827 if (!clk
|| WARN_ON_ONCE(IS_ERR(clk
)))
2830 clk_debug_unregister(clk
->core
);
2834 if (clk
->core
->ops
== &clk_nodrv_ops
) {
2835 pr_err("%s: unregistered clock: %s\n", __func__
,
2840 * Assign empty clock ops for consumers that might still hold
2841 * a reference to this clock.
2843 flags
= clk_enable_lock();
2844 clk
->core
->ops
= &clk_nodrv_ops
;
2845 clk_enable_unlock(flags
);
2847 if (!hlist_empty(&clk
->core
->children
)) {
2848 struct clk_core
*child
;
2849 struct hlist_node
*t
;
2851 /* Reparent all children to the orphan list. */
2852 hlist_for_each_entry_safe(child
, t
, &clk
->core
->children
,
2854 clk_core_set_parent(child
, NULL
);
2857 hlist_del_init(&clk
->core
->child_node
);
2859 if (clk
->core
->prepare_count
)
2860 pr_warn("%s: unregistering prepared clock: %s\n",
2861 __func__
, clk
->core
->name
);
2862 kref_put(&clk
->core
->ref
, __clk_release
);
2864 clk_prepare_unlock();
2866 EXPORT_SYMBOL_GPL(clk_unregister
);
2869 * clk_hw_unregister - unregister a currently registered clk_hw
2870 * @hw: hardware-specific clock data to unregister
2872 void clk_hw_unregister(struct clk_hw
*hw
)
2874 clk_unregister(hw
->clk
);
2876 EXPORT_SYMBOL_GPL(clk_hw_unregister
);
2878 static void devm_clk_release(struct device
*dev
, void *res
)
2880 clk_unregister(*(struct clk
**)res
);
2883 static void devm_clk_hw_release(struct device
*dev
, void *res
)
2885 clk_hw_unregister(*(struct clk_hw
**)res
);
2889 * devm_clk_register - resource managed clk_register()
2890 * @dev: device that is registering this clock
2891 * @hw: link to hardware-specific clock data
2893 * Managed clk_register(). Clocks returned from this function are
2894 * automatically clk_unregister()ed on driver detach. See clk_register() for
2897 struct clk
*devm_clk_register(struct device
*dev
, struct clk_hw
*hw
)
2902 clkp
= devres_alloc(devm_clk_release
, sizeof(*clkp
), GFP_KERNEL
);
2904 return ERR_PTR(-ENOMEM
);
2906 clk
= clk_register(dev
, hw
);
2909 devres_add(dev
, clkp
);
2916 EXPORT_SYMBOL_GPL(devm_clk_register
);
2919 * devm_clk_hw_register - resource managed clk_hw_register()
2920 * @dev: device that is registering this clock
2921 * @hw: link to hardware-specific clock data
2923 * Managed clk_hw_register(). Clocks registered by this function are
2924 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
2925 * for more information.
2927 int devm_clk_hw_register(struct device
*dev
, struct clk_hw
*hw
)
2929 struct clk_hw
**hwp
;
2932 hwp
= devres_alloc(devm_clk_hw_release
, sizeof(*hwp
), GFP_KERNEL
);
2936 ret
= clk_hw_register(dev
, hw
);
2939 devres_add(dev
, hwp
);
2946 EXPORT_SYMBOL_GPL(devm_clk_hw_register
);
2948 static int devm_clk_match(struct device
*dev
, void *res
, void *data
)
2950 struct clk
*c
= res
;
2956 static int devm_clk_hw_match(struct device
*dev
, void *res
, void *data
)
2958 struct clk_hw
*hw
= res
;
2966 * devm_clk_unregister - resource managed clk_unregister()
2967 * @clk: clock to unregister
2969 * Deallocate a clock allocated with devm_clk_register(). Normally
2970 * this function will not need to be called and the resource management
2971 * code will ensure that the resource is freed.
2973 void devm_clk_unregister(struct device
*dev
, struct clk
*clk
)
2975 WARN_ON(devres_release(dev
, devm_clk_release
, devm_clk_match
, clk
));
2977 EXPORT_SYMBOL_GPL(devm_clk_unregister
);
2980 * devm_clk_hw_unregister - resource managed clk_hw_unregister()
2981 * @dev: device that is unregistering the hardware-specific clock data
2982 * @hw: link to hardware-specific clock data
2984 * Unregister a clk_hw registered with devm_clk_hw_register(). Normally
2985 * this function will not need to be called and the resource management
2986 * code will ensure that the resource is freed.
2988 void devm_clk_hw_unregister(struct device
*dev
, struct clk_hw
*hw
)
2990 WARN_ON(devres_release(dev
, devm_clk_hw_release
, devm_clk_hw_match
,
2993 EXPORT_SYMBOL_GPL(devm_clk_hw_unregister
);
2998 int __clk_get(struct clk
*clk
)
3000 struct clk_core
*core
= !clk
? NULL
: clk
->core
;
3003 if (!try_module_get(core
->owner
))
3006 kref_get(&core
->ref
);
3011 void __clk_put(struct clk
*clk
)
3013 struct module
*owner
;
3015 if (!clk
|| WARN_ON_ONCE(IS_ERR(clk
)))
3020 hlist_del(&clk
->clks_node
);
3021 if (clk
->min_rate
> clk
->core
->req_rate
||
3022 clk
->max_rate
< clk
->core
->req_rate
)
3023 clk_core_set_rate_nolock(clk
->core
, clk
->core
->req_rate
);
3025 owner
= clk
->core
->owner
;
3026 kref_put(&clk
->core
->ref
, __clk_release
);
3028 clk_prepare_unlock();
3035 /*** clk rate change notifiers ***/
3038 * clk_notifier_register - add a clk rate change notifier
3039 * @clk: struct clk * to watch
3040 * @nb: struct notifier_block * with callback info
3042 * Request notification when clk's rate changes. This uses an SRCU
3043 * notifier because we want it to block and notifier unregistrations are
3044 * uncommon. The callbacks associated with the notifier must not
3045 * re-enter into the clk framework by calling any top-level clk APIs;
3046 * this will cause a nested prepare_lock mutex.
3048 * In all notification cases (pre, post and abort rate change) the original
3049 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
3050 * and the new frequency is passed via struct clk_notifier_data.new_rate.
3052 * clk_notifier_register() must be called from non-atomic context.
3053 * Returns -EINVAL if called with null arguments, -ENOMEM upon
3054 * allocation failure; otherwise, passes along the return value of
3055 * srcu_notifier_chain_register().
3057 int clk_notifier_register(struct clk
*clk
, struct notifier_block
*nb
)
3059 struct clk_notifier
*cn
;
3067 /* search the list of notifiers for this clk */
3068 list_for_each_entry(cn
, &clk_notifier_list
, node
)
3072 /* if clk wasn't in the notifier list, allocate new clk_notifier */
3073 if (cn
->clk
!= clk
) {
3074 cn
= kzalloc(sizeof(*cn
), GFP_KERNEL
);
3079 srcu_init_notifier_head(&cn
->notifier_head
);
3081 list_add(&cn
->node
, &clk_notifier_list
);
3084 ret
= srcu_notifier_chain_register(&cn
->notifier_head
, nb
);
3086 clk
->core
->notifier_count
++;
3089 clk_prepare_unlock();
3093 EXPORT_SYMBOL_GPL(clk_notifier_register
);
3096 * clk_notifier_unregister - remove a clk rate change notifier
3097 * @clk: struct clk *
3098 * @nb: struct notifier_block * with callback info
3100 * Request no further notification for changes to 'clk' and frees memory
3101 * allocated in clk_notifier_register.
3103 * Returns -EINVAL if called with null arguments; otherwise, passes
3104 * along the return value of srcu_notifier_chain_unregister().
3106 int clk_notifier_unregister(struct clk
*clk
, struct notifier_block
*nb
)
3108 struct clk_notifier
*cn
= NULL
;
3116 list_for_each_entry(cn
, &clk_notifier_list
, node
)
3120 if (cn
->clk
== clk
) {
3121 ret
= srcu_notifier_chain_unregister(&cn
->notifier_head
, nb
);
3123 clk
->core
->notifier_count
--;
3125 /* XXX the notifier code should handle this better */
3126 if (!cn
->notifier_head
.head
) {
3127 srcu_cleanup_notifier_head(&cn
->notifier_head
);
3128 list_del(&cn
->node
);
3136 clk_prepare_unlock();
3140 EXPORT_SYMBOL_GPL(clk_notifier_unregister
);
3144 * struct of_clk_provider - Clock provider registration structure
3145 * @link: Entry in global list of clock providers
3146 * @node: Pointer to device tree node of clock provider
3147 * @get: Get clock callback. Returns NULL or a struct clk for the
3148 * given clock specifier
3149 * @data: context pointer to be passed into @get callback
3151 struct of_clk_provider
{
3152 struct list_head link
;
3154 struct device_node
*node
;
3155 struct clk
*(*get
)(struct of_phandle_args
*clkspec
, void *data
);
3156 struct clk_hw
*(*get_hw
)(struct of_phandle_args
*clkspec
, void *data
);
3160 static const struct of_device_id __clk_of_table_sentinel
3161 __used
__section(__clk_of_table_end
);
3163 static LIST_HEAD(of_clk_providers
);
3164 static DEFINE_MUTEX(of_clk_mutex
);
3166 struct clk
*of_clk_src_simple_get(struct of_phandle_args
*clkspec
,
3171 EXPORT_SYMBOL_GPL(of_clk_src_simple_get
);
3173 struct clk_hw
*of_clk_hw_simple_get(struct of_phandle_args
*clkspec
, void *data
)
3177 EXPORT_SYMBOL_GPL(of_clk_hw_simple_get
);
3179 struct clk
*of_clk_src_onecell_get(struct of_phandle_args
*clkspec
, void *data
)
3181 struct clk_onecell_data
*clk_data
= data
;
3182 unsigned int idx
= clkspec
->args
[0];
3184 if (idx
>= clk_data
->clk_num
) {
3185 pr_err("%s: invalid clock index %u\n", __func__
, idx
);
3186 return ERR_PTR(-EINVAL
);
3189 return clk_data
->clks
[idx
];
3191 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get
);
3194 of_clk_hw_onecell_get(struct of_phandle_args
*clkspec
, void *data
)
3196 struct clk_hw_onecell_data
*hw_data
= data
;
3197 unsigned int idx
= clkspec
->args
[0];
3199 if (idx
>= hw_data
->num
) {
3200 pr_err("%s: invalid index %u\n", __func__
, idx
);
3201 return ERR_PTR(-EINVAL
);
3204 return hw_data
->hws
[idx
];
3206 EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get
);
3209 * of_clk_add_provider() - Register a clock provider for a node
3210 * @np: Device node pointer associated with clock provider
3211 * @clk_src_get: callback for decoding clock
3212 * @data: context pointer for @clk_src_get callback.
3214 int of_clk_add_provider(struct device_node
*np
,
3215 struct clk
*(*clk_src_get
)(struct of_phandle_args
*clkspec
,
3219 struct of_clk_provider
*cp
;
3222 cp
= kzalloc(sizeof(*cp
), GFP_KERNEL
);
3226 cp
->node
= of_node_get(np
);
3228 cp
->get
= clk_src_get
;
3230 mutex_lock(&of_clk_mutex
);
3231 list_add(&cp
->link
, &of_clk_providers
);
3232 mutex_unlock(&of_clk_mutex
);
3233 pr_debug("Added clock from %pOF\n", np
);
3235 ret
= of_clk_set_defaults(np
, true);
3237 of_clk_del_provider(np
);
3241 EXPORT_SYMBOL_GPL(of_clk_add_provider
);
3244 * of_clk_add_hw_provider() - Register a clock provider for a node
3245 * @np: Device node pointer associated with clock provider
3246 * @get: callback for decoding clk_hw
3247 * @data: context pointer for @get callback.
3249 int of_clk_add_hw_provider(struct device_node
*np
,
3250 struct clk_hw
*(*get
)(struct of_phandle_args
*clkspec
,
3254 struct of_clk_provider
*cp
;
3257 cp
= kzalloc(sizeof(*cp
), GFP_KERNEL
);
3261 cp
->node
= of_node_get(np
);
3265 mutex_lock(&of_clk_mutex
);
3266 list_add(&cp
->link
, &of_clk_providers
);
3267 mutex_unlock(&of_clk_mutex
);
3268 pr_debug("Added clk_hw provider from %pOF\n", np
);
3270 ret
= of_clk_set_defaults(np
, true);
3272 of_clk_del_provider(np
);
3276 EXPORT_SYMBOL_GPL(of_clk_add_hw_provider
);
3278 static void devm_of_clk_release_provider(struct device
*dev
, void *res
)
3280 of_clk_del_provider(*(struct device_node
**)res
);
3283 int devm_of_clk_add_hw_provider(struct device
*dev
,
3284 struct clk_hw
*(*get
)(struct of_phandle_args
*clkspec
,
3288 struct device_node
**ptr
, *np
;
3291 ptr
= devres_alloc(devm_of_clk_release_provider
, sizeof(*ptr
),
3297 ret
= of_clk_add_hw_provider(np
, get
, data
);
3300 devres_add(dev
, ptr
);
3307 EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider
);
3310 * of_clk_del_provider() - Remove a previously registered clock provider
3311 * @np: Device node pointer associated with clock provider
3313 void of_clk_del_provider(struct device_node
*np
)
3315 struct of_clk_provider
*cp
;
3317 mutex_lock(&of_clk_mutex
);
3318 list_for_each_entry(cp
, &of_clk_providers
, link
) {
3319 if (cp
->node
== np
) {
3320 list_del(&cp
->link
);
3321 of_node_put(cp
->node
);
3326 mutex_unlock(&of_clk_mutex
);
3328 EXPORT_SYMBOL_GPL(of_clk_del_provider
);
3330 static int devm_clk_provider_match(struct device
*dev
, void *res
, void *data
)
3332 struct device_node
**np
= res
;
3334 if (WARN_ON(!np
|| !*np
))
3340 void devm_of_clk_del_provider(struct device
*dev
)
3344 ret
= devres_release(dev
, devm_of_clk_release_provider
,
3345 devm_clk_provider_match
, dev
->of_node
);
3349 EXPORT_SYMBOL(devm_of_clk_del_provider
);
3351 static struct clk_hw
*
3352 __of_clk_get_hw_from_provider(struct of_clk_provider
*provider
,
3353 struct of_phandle_args
*clkspec
)
3357 if (provider
->get_hw
)
3358 return provider
->get_hw(clkspec
, provider
->data
);
3360 clk
= provider
->get(clkspec
, provider
->data
);
3362 return ERR_CAST(clk
);
3363 return __clk_get_hw(clk
);
3366 struct clk
*__of_clk_get_from_provider(struct of_phandle_args
*clkspec
,
3367 const char *dev_id
, const char *con_id
)
3369 struct of_clk_provider
*provider
;
3370 struct clk
*clk
= ERR_PTR(-EPROBE_DEFER
);
3374 return ERR_PTR(-EINVAL
);
3376 /* Check if we have such a provider in our array */
3377 mutex_lock(&of_clk_mutex
);
3378 list_for_each_entry(provider
, &of_clk_providers
, link
) {
3379 if (provider
->node
== clkspec
->np
) {
3380 hw
= __of_clk_get_hw_from_provider(provider
, clkspec
);
3381 clk
= __clk_create_clk(hw
, dev_id
, con_id
);
3385 if (!__clk_get(clk
)) {
3386 __clk_free_clk(clk
);
3387 clk
= ERR_PTR(-ENOENT
);
3393 mutex_unlock(&of_clk_mutex
);
3399 * of_clk_get_from_provider() - Lookup a clock from a clock provider
3400 * @clkspec: pointer to a clock specifier data structure
3402 * This function looks up a struct clk from the registered list of clock
3403 * providers, an input is a clock specifier data structure as returned
3404 * from the of_parse_phandle_with_args() function call.
3406 struct clk
*of_clk_get_from_provider(struct of_phandle_args
*clkspec
)
3408 return __of_clk_get_from_provider(clkspec
, NULL
, __func__
);
3410 EXPORT_SYMBOL_GPL(of_clk_get_from_provider
);
3413 * of_clk_get_parent_count() - Count the number of clocks a device node has
3414 * @np: device node to count
3416 * Returns: The number of clocks that are possible parents of this node
3418 unsigned int of_clk_get_parent_count(struct device_node
*np
)
3422 count
= of_count_phandle_with_args(np
, "clocks", "#clock-cells");
3428 EXPORT_SYMBOL_GPL(of_clk_get_parent_count
);
3430 const char *of_clk_get_parent_name(struct device_node
*np
, int index
)
3432 struct of_phandle_args clkspec
;
3433 struct property
*prop
;
3434 const char *clk_name
;
3441 rc
= of_parse_phandle_with_args(np
, "clocks", "#clock-cells", index
,
3446 index
= clkspec
.args_count
? clkspec
.args
[0] : 0;
3449 /* if there is an indices property, use it to transfer the index
3450 * specified into an array offset for the clock-output-names property.
3452 of_property_for_each_u32(clkspec
.np
, "clock-indices", prop
, vp
, pv
) {
3459 /* We went off the end of 'clock-indices' without finding it */
3463 if (of_property_read_string_index(clkspec
.np
, "clock-output-names",
3467 * Best effort to get the name if the clock has been
3468 * registered with the framework. If the clock isn't
3469 * registered, we return the node name as the name of
3470 * the clock as long as #clock-cells = 0.
3472 clk
= of_clk_get_from_provider(&clkspec
);
3474 if (clkspec
.args_count
== 0)
3475 clk_name
= clkspec
.np
->name
;
3479 clk_name
= __clk_get_name(clk
);
3485 of_node_put(clkspec
.np
);
3488 EXPORT_SYMBOL_GPL(of_clk_get_parent_name
);
3491 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
3493 * @np: Device node pointer associated with clock provider
3494 * @parents: pointer to char array that hold the parents' names
3495 * @size: size of the @parents array
3497 * Return: number of parents for the clock node.
3499 int of_clk_parent_fill(struct device_node
*np
, const char **parents
,
3504 while (i
< size
&& (parents
[i
] = of_clk_get_parent_name(np
, i
)) != NULL
)
3509 EXPORT_SYMBOL_GPL(of_clk_parent_fill
);
3511 struct clock_provider
{
3512 of_clk_init_cb_t clk_init_cb
;
3513 struct device_node
*np
;
3514 struct list_head node
;
3518 * This function looks for a parent clock. If there is one, then it
3519 * checks that the provider for this parent clock was initialized, in
3520 * this case the parent clock will be ready.
3522 static int parent_ready(struct device_node
*np
)
3527 struct clk
*clk
= of_clk_get(np
, i
);
3529 /* this parent is ready we can check the next one */
3536 /* at least one parent is not ready, we exit now */
3537 if (PTR_ERR(clk
) == -EPROBE_DEFER
)
3541 * Here we make assumption that the device tree is
3542 * written correctly. So an error means that there is
3543 * no more parent. As we didn't exit yet, then the
3544 * previous parent are ready. If there is no clock
3545 * parent, no need to wait for them, then we can
3546 * consider their absence as being ready
3553 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
3554 * @np: Device node pointer associated with clock provider
3555 * @index: clock index
3556 * @flags: pointer to clk_core->flags
3558 * Detects if the clock-critical property exists and, if so, sets the
3559 * corresponding CLK_IS_CRITICAL flag.
3561 * Do not use this function. It exists only for legacy Device Tree
3562 * bindings, such as the one-clock-per-node style that are outdated.
3563 * Those bindings typically put all clock data into .dts and the Linux
3564 * driver has no clock data, thus making it impossible to set this flag
3565 * correctly from the driver. Only those drivers may call
3566 * of_clk_detect_critical from their setup functions.
3568 * Return: error code or zero on success
3570 int of_clk_detect_critical(struct device_node
*np
,
3571 int index
, unsigned long *flags
)
3573 struct property
*prop
;
3580 of_property_for_each_u32(np
, "clock-critical", prop
, cur
, idx
)
3582 *flags
|= CLK_IS_CRITICAL
;
3588 * of_clk_init() - Scan and init clock providers from the DT
3589 * @matches: array of compatible values and init functions for providers.
3591 * This function scans the device tree for matching clock providers
3592 * and calls their initialization functions. It also does it by trying
3593 * to follow the dependencies.
3595 void __init
of_clk_init(const struct of_device_id
*matches
)
3597 const struct of_device_id
*match
;
3598 struct device_node
*np
;
3599 struct clock_provider
*clk_provider
, *next
;
3602 LIST_HEAD(clk_provider_list
);
3605 matches
= &__clk_of_table
;
3607 /* First prepare the list of the clocks providers */
3608 for_each_matching_node_and_match(np
, matches
, &match
) {
3609 struct clock_provider
*parent
;
3611 if (!of_device_is_available(np
))
3614 parent
= kzalloc(sizeof(*parent
), GFP_KERNEL
);
3616 list_for_each_entry_safe(clk_provider
, next
,
3617 &clk_provider_list
, node
) {
3618 list_del(&clk_provider
->node
);
3619 of_node_put(clk_provider
->np
);
3620 kfree(clk_provider
);
3626 parent
->clk_init_cb
= match
->data
;
3627 parent
->np
= of_node_get(np
);
3628 list_add_tail(&parent
->node
, &clk_provider_list
);
3631 while (!list_empty(&clk_provider_list
)) {
3632 is_init_done
= false;
3633 list_for_each_entry_safe(clk_provider
, next
,
3634 &clk_provider_list
, node
) {
3635 if (force
|| parent_ready(clk_provider
->np
)) {
3637 /* Don't populate platform devices */
3638 of_node_set_flag(clk_provider
->np
,
3641 clk_provider
->clk_init_cb(clk_provider
->np
);
3642 of_clk_set_defaults(clk_provider
->np
, true);
3644 list_del(&clk_provider
->node
);
3645 of_node_put(clk_provider
->np
);
3646 kfree(clk_provider
);
3647 is_init_done
= true;
3652 * We didn't manage to initialize any of the
3653 * remaining providers during the last loop, so now we
3654 * initialize all the remaining ones unconditionally
3655 * in case the clock parent was not mandatory