2 * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
3 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * Standard functionality for the common clock API. See Documentation/clk.txt
12 #include <linux/clk.h>
13 #include <linux/clk-provider.h>
14 #include <linux/clk/clk-conf.h>
15 #include <linux/module.h>
16 #include <linux/mutex.h>
17 #include <linux/spinlock.h>
18 #include <linux/err.h>
19 #include <linux/list.h>
20 #include <linux/slab.h>
22 #include <linux/device.h>
23 #include <linux/init.h>
24 #include <linux/sched.h>
25 #include <linux/clkdev.h>
29 static DEFINE_SPINLOCK(enable_lock
);
30 static DEFINE_MUTEX(prepare_lock
);
32 static struct task_struct
*prepare_owner
;
33 static struct task_struct
*enable_owner
;
35 static int prepare_refcnt
;
36 static int enable_refcnt
;
38 static HLIST_HEAD(clk_root_list
);
39 static HLIST_HEAD(clk_orphan_list
);
40 static LIST_HEAD(clk_notifier_list
);
42 /*** private data structures ***/
46 const struct clk_ops
*ops
;
49 struct clk_core
*parent
;
50 const char **parent_names
;
51 struct clk_core
**parents
;
55 unsigned long req_rate
;
56 unsigned long new_rate
;
57 struct clk_core
*new_parent
;
58 struct clk_core
*new_child
;
61 unsigned int enable_count
;
62 unsigned int prepare_count
;
63 unsigned long min_rate
;
64 unsigned long max_rate
;
65 unsigned long accuracy
;
67 struct hlist_head children
;
68 struct hlist_node child_node
;
69 struct hlist_head clks
;
70 unsigned int notifier_count
;
71 #ifdef CONFIG_DEBUG_FS
72 struct dentry
*dentry
;
73 struct hlist_node debug_node
;
78 #define CREATE_TRACE_POINTS
79 #include <trace/events/clk.h>
82 struct clk_core
*core
;
85 unsigned long min_rate
;
86 unsigned long max_rate
;
87 struct hlist_node clks_node
;
91 static void clk_prepare_lock(void)
93 if (!mutex_trylock(&prepare_lock
)) {
94 if (prepare_owner
== current
) {
98 mutex_lock(&prepare_lock
);
100 WARN_ON_ONCE(prepare_owner
!= NULL
);
101 WARN_ON_ONCE(prepare_refcnt
!= 0);
102 prepare_owner
= current
;
106 static void clk_prepare_unlock(void)
108 WARN_ON_ONCE(prepare_owner
!= current
);
109 WARN_ON_ONCE(prepare_refcnt
== 0);
111 if (--prepare_refcnt
)
113 prepare_owner
= NULL
;
114 mutex_unlock(&prepare_lock
);
117 static unsigned long clk_enable_lock(void)
118 __acquires(enable_lock
)
122 if (!spin_trylock_irqsave(&enable_lock
, flags
)) {
123 if (enable_owner
== current
) {
125 __acquire(enable_lock
);
128 spin_lock_irqsave(&enable_lock
, flags
);
130 WARN_ON_ONCE(enable_owner
!= NULL
);
131 WARN_ON_ONCE(enable_refcnt
!= 0);
132 enable_owner
= current
;
137 static void clk_enable_unlock(unsigned long flags
)
138 __releases(enable_lock
)
140 WARN_ON_ONCE(enable_owner
!= current
);
141 WARN_ON_ONCE(enable_refcnt
== 0);
143 if (--enable_refcnt
) {
144 __release(enable_lock
);
148 spin_unlock_irqrestore(&enable_lock
, flags
);
151 static bool clk_core_is_prepared(struct clk_core
*core
)
154 * .is_prepared is optional for clocks that can prepare
155 * fall back to software usage counter if it is missing
157 if (!core
->ops
->is_prepared
)
158 return core
->prepare_count
;
160 return core
->ops
->is_prepared(core
->hw
);
163 static bool clk_core_is_enabled(struct clk_core
*core
)
166 * .is_enabled is only mandatory for clocks that gate
167 * fall back to software usage counter if .is_enabled is missing
169 if (!core
->ops
->is_enabled
)
170 return core
->enable_count
;
172 return core
->ops
->is_enabled(core
->hw
);
175 static void clk_unprepare_unused_subtree(struct clk_core
*core
)
177 struct clk_core
*child
;
179 lockdep_assert_held(&prepare_lock
);
181 hlist_for_each_entry(child
, &core
->children
, child_node
)
182 clk_unprepare_unused_subtree(child
);
184 if (core
->prepare_count
)
187 if (core
->flags
& CLK_IGNORE_UNUSED
)
190 if (clk_core_is_prepared(core
)) {
191 trace_clk_unprepare(core
);
192 if (core
->ops
->unprepare_unused
)
193 core
->ops
->unprepare_unused(core
->hw
);
194 else if (core
->ops
->unprepare
)
195 core
->ops
->unprepare(core
->hw
);
196 trace_clk_unprepare_complete(core
);
200 static void clk_disable_unused_subtree(struct clk_core
*core
)
202 struct clk_core
*child
;
205 lockdep_assert_held(&prepare_lock
);
207 hlist_for_each_entry(child
, &core
->children
, child_node
)
208 clk_disable_unused_subtree(child
);
210 flags
= clk_enable_lock();
212 if (core
->enable_count
)
215 if (core
->flags
& CLK_IGNORE_UNUSED
)
219 * some gate clocks have special needs during the disable-unused
220 * sequence. call .disable_unused if available, otherwise fall
223 if (clk_core_is_enabled(core
)) {
224 trace_clk_disable(core
);
225 if (core
->ops
->disable_unused
)
226 core
->ops
->disable_unused(core
->hw
);
227 else if (core
->ops
->disable
)
228 core
->ops
->disable(core
->hw
);
229 trace_clk_disable_complete(core
);
233 clk_enable_unlock(flags
);
236 static bool clk_ignore_unused
;
237 static int __init
clk_ignore_unused_setup(char *__unused
)
239 clk_ignore_unused
= true;
242 __setup("clk_ignore_unused", clk_ignore_unused_setup
);
244 static int clk_disable_unused(void)
246 struct clk_core
*core
;
248 if (clk_ignore_unused
) {
249 pr_warn("clk: Not disabling unused clocks\n");
255 hlist_for_each_entry(core
, &clk_root_list
, child_node
)
256 clk_disable_unused_subtree(core
);
258 hlist_for_each_entry(core
, &clk_orphan_list
, child_node
)
259 clk_disable_unused_subtree(core
);
261 hlist_for_each_entry(core
, &clk_root_list
, child_node
)
262 clk_unprepare_unused_subtree(core
);
264 hlist_for_each_entry(core
, &clk_orphan_list
, child_node
)
265 clk_unprepare_unused_subtree(core
);
267 clk_prepare_unlock();
271 late_initcall_sync(clk_disable_unused
);
273 /*** helper functions ***/
275 const char *__clk_get_name(struct clk
*clk
)
277 return !clk
? NULL
: clk
->core
->name
;
279 EXPORT_SYMBOL_GPL(__clk_get_name
);
281 const char *clk_hw_get_name(const struct clk_hw
*hw
)
283 return hw
->core
->name
;
285 EXPORT_SYMBOL_GPL(clk_hw_get_name
);
287 struct clk_hw
*__clk_get_hw(struct clk
*clk
)
289 return !clk
? NULL
: clk
->core
->hw
;
291 EXPORT_SYMBOL_GPL(__clk_get_hw
);
293 unsigned int clk_hw_get_num_parents(const struct clk_hw
*hw
)
295 return hw
->core
->num_parents
;
297 EXPORT_SYMBOL_GPL(clk_hw_get_num_parents
);
299 struct clk_hw
*clk_hw_get_parent(const struct clk_hw
*hw
)
301 return hw
->core
->parent
? hw
->core
->parent
->hw
: NULL
;
303 EXPORT_SYMBOL_GPL(clk_hw_get_parent
);
305 static struct clk_core
*__clk_lookup_subtree(const char *name
,
306 struct clk_core
*core
)
308 struct clk_core
*child
;
309 struct clk_core
*ret
;
311 if (!strcmp(core
->name
, name
))
314 hlist_for_each_entry(child
, &core
->children
, child_node
) {
315 ret
= __clk_lookup_subtree(name
, child
);
323 static struct clk_core
*clk_core_lookup(const char *name
)
325 struct clk_core
*root_clk
;
326 struct clk_core
*ret
;
331 /* search the 'proper' clk tree first */
332 hlist_for_each_entry(root_clk
, &clk_root_list
, child_node
) {
333 ret
= __clk_lookup_subtree(name
, root_clk
);
338 /* if not found, then search the orphan tree */
339 hlist_for_each_entry(root_clk
, &clk_orphan_list
, child_node
) {
340 ret
= __clk_lookup_subtree(name
, root_clk
);
348 static struct clk_core
*clk_core_get_parent_by_index(struct clk_core
*core
,
351 if (!core
|| index
>= core
->num_parents
)
353 else if (!core
->parents
)
354 return clk_core_lookup(core
->parent_names
[index
]);
355 else if (!core
->parents
[index
])
356 return core
->parents
[index
] =
357 clk_core_lookup(core
->parent_names
[index
]);
359 return core
->parents
[index
];
363 clk_hw_get_parent_by_index(const struct clk_hw
*hw
, unsigned int index
)
365 struct clk_core
*parent
;
367 parent
= clk_core_get_parent_by_index(hw
->core
, index
);
369 return !parent
? NULL
: parent
->hw
;
371 EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index
);
373 unsigned int __clk_get_enable_count(struct clk
*clk
)
375 return !clk
? 0 : clk
->core
->enable_count
;
378 static unsigned long clk_core_get_rate_nolock(struct clk_core
*core
)
389 if (core
->flags
& CLK_IS_ROOT
)
399 unsigned long clk_hw_get_rate(const struct clk_hw
*hw
)
401 return clk_core_get_rate_nolock(hw
->core
);
403 EXPORT_SYMBOL_GPL(clk_hw_get_rate
);
405 static unsigned long __clk_get_accuracy(struct clk_core
*core
)
410 return core
->accuracy
;
413 unsigned long __clk_get_flags(struct clk
*clk
)
415 return !clk
? 0 : clk
->core
->flags
;
417 EXPORT_SYMBOL_GPL(__clk_get_flags
);
419 unsigned long clk_hw_get_flags(const struct clk_hw
*hw
)
421 return hw
->core
->flags
;
423 EXPORT_SYMBOL_GPL(clk_hw_get_flags
);
425 bool clk_hw_is_prepared(const struct clk_hw
*hw
)
427 return clk_core_is_prepared(hw
->core
);
430 bool __clk_is_enabled(struct clk
*clk
)
435 return clk_core_is_enabled(clk
->core
);
437 EXPORT_SYMBOL_GPL(__clk_is_enabled
);
439 static bool mux_is_better_rate(unsigned long rate
, unsigned long now
,
440 unsigned long best
, unsigned long flags
)
442 if (flags
& CLK_MUX_ROUND_CLOSEST
)
443 return abs(now
- rate
) < abs(best
- rate
);
445 return now
<= rate
&& now
> best
;
449 clk_mux_determine_rate_flags(struct clk_hw
*hw
, struct clk_rate_request
*req
,
452 struct clk_core
*core
= hw
->core
, *parent
, *best_parent
= NULL
;
453 int i
, num_parents
, ret
;
454 unsigned long best
= 0;
455 struct clk_rate_request parent_req
= *req
;
457 /* if NO_REPARENT flag set, pass through to current parent */
458 if (core
->flags
& CLK_SET_RATE_NO_REPARENT
) {
459 parent
= core
->parent
;
460 if (core
->flags
& CLK_SET_RATE_PARENT
) {
461 ret
= __clk_determine_rate(parent
? parent
->hw
: NULL
,
466 best
= parent_req
.rate
;
468 best
= clk_core_get_rate_nolock(parent
);
470 best
= clk_core_get_rate_nolock(core
);
476 /* find the parent that can provide the fastest rate <= rate */
477 num_parents
= core
->num_parents
;
478 for (i
= 0; i
< num_parents
; i
++) {
479 parent
= clk_core_get_parent_by_index(core
, i
);
483 if (core
->flags
& CLK_SET_RATE_PARENT
) {
485 ret
= __clk_determine_rate(parent
->hw
, &parent_req
);
489 parent_req
.rate
= clk_core_get_rate_nolock(parent
);
492 if (mux_is_better_rate(req
->rate
, parent_req
.rate
,
494 best_parent
= parent
;
495 best
= parent_req
.rate
;
504 req
->best_parent_hw
= best_parent
->hw
;
505 req
->best_parent_rate
= best
;
511 struct clk
*__clk_lookup(const char *name
)
513 struct clk_core
*core
= clk_core_lookup(name
);
515 return !core
? NULL
: core
->hw
->clk
;
518 static void clk_core_get_boundaries(struct clk_core
*core
,
519 unsigned long *min_rate
,
520 unsigned long *max_rate
)
522 struct clk
*clk_user
;
524 *min_rate
= core
->min_rate
;
525 *max_rate
= core
->max_rate
;
527 hlist_for_each_entry(clk_user
, &core
->clks
, clks_node
)
528 *min_rate
= max(*min_rate
, clk_user
->min_rate
);
530 hlist_for_each_entry(clk_user
, &core
->clks
, clks_node
)
531 *max_rate
= min(*max_rate
, clk_user
->max_rate
);
534 void clk_hw_set_rate_range(struct clk_hw
*hw
, unsigned long min_rate
,
535 unsigned long max_rate
)
537 hw
->core
->min_rate
= min_rate
;
538 hw
->core
->max_rate
= max_rate
;
540 EXPORT_SYMBOL_GPL(clk_hw_set_rate_range
);
543 * Helper for finding best parent to provide a given frequency. This can be used
544 * directly as a determine_rate callback (e.g. for a mux), or from a more
545 * complex clock that may combine a mux with other operations.
547 int __clk_mux_determine_rate(struct clk_hw
*hw
,
548 struct clk_rate_request
*req
)
550 return clk_mux_determine_rate_flags(hw
, req
, 0);
552 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate
);
554 int __clk_mux_determine_rate_closest(struct clk_hw
*hw
,
555 struct clk_rate_request
*req
)
557 return clk_mux_determine_rate_flags(hw
, req
, CLK_MUX_ROUND_CLOSEST
);
559 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest
);
563 static void clk_core_unprepare(struct clk_core
*core
)
565 lockdep_assert_held(&prepare_lock
);
570 if (WARN_ON(core
->prepare_count
== 0))
573 if (--core
->prepare_count
> 0)
576 WARN_ON(core
->enable_count
> 0);
578 trace_clk_unprepare(core
);
580 if (core
->ops
->unprepare
)
581 core
->ops
->unprepare(core
->hw
);
583 trace_clk_unprepare_complete(core
);
584 clk_core_unprepare(core
->parent
);
588 * clk_unprepare - undo preparation of a clock source
589 * @clk: the clk being unprepared
591 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
592 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
593 * if the operation may sleep. One example is a clk which is accessed over
594 * I2c. In the complex case a clk gate operation may require a fast and a slow
595 * part. It is this reason that clk_unprepare and clk_disable are not mutually
596 * exclusive. In fact clk_disable must be called before clk_unprepare.
598 void clk_unprepare(struct clk
*clk
)
600 if (IS_ERR_OR_NULL(clk
))
604 clk_core_unprepare(clk
->core
);
605 clk_prepare_unlock();
607 EXPORT_SYMBOL_GPL(clk_unprepare
);
609 static int clk_core_prepare(struct clk_core
*core
)
613 lockdep_assert_held(&prepare_lock
);
618 if (core
->prepare_count
== 0) {
619 ret
= clk_core_prepare(core
->parent
);
623 trace_clk_prepare(core
);
625 if (core
->ops
->prepare
)
626 ret
= core
->ops
->prepare(core
->hw
);
628 trace_clk_prepare_complete(core
);
631 clk_core_unprepare(core
->parent
);
636 core
->prepare_count
++;
642 * clk_prepare - prepare a clock source
643 * @clk: the clk being prepared
645 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
646 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
647 * operation may sleep. One example is a clk which is accessed over I2c. In
648 * the complex case a clk ungate operation may require a fast and a slow part.
649 * It is this reason that clk_prepare and clk_enable are not mutually
650 * exclusive. In fact clk_prepare must be called before clk_enable.
651 * Returns 0 on success, -EERROR otherwise.
653 int clk_prepare(struct clk
*clk
)
661 ret
= clk_core_prepare(clk
->core
);
662 clk_prepare_unlock();
666 EXPORT_SYMBOL_GPL(clk_prepare
);
668 static void clk_core_disable(struct clk_core
*core
)
670 lockdep_assert_held(&enable_lock
);
675 if (WARN_ON(core
->enable_count
== 0))
678 if (--core
->enable_count
> 0)
681 trace_clk_disable(core
);
683 if (core
->ops
->disable
)
684 core
->ops
->disable(core
->hw
);
686 trace_clk_disable_complete(core
);
688 clk_core_disable(core
->parent
);
692 * clk_disable - gate a clock
693 * @clk: the clk being gated
695 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
696 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
697 * clk if the operation is fast and will never sleep. One example is a
698 * SoC-internal clk which is controlled via simple register writes. In the
699 * complex case a clk gate operation may require a fast and a slow part. It is
700 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
701 * In fact clk_disable must be called before clk_unprepare.
703 void clk_disable(struct clk
*clk
)
707 if (IS_ERR_OR_NULL(clk
))
710 flags
= clk_enable_lock();
711 clk_core_disable(clk
->core
);
712 clk_enable_unlock(flags
);
714 EXPORT_SYMBOL_GPL(clk_disable
);
716 static int clk_core_enable(struct clk_core
*core
)
720 lockdep_assert_held(&enable_lock
);
725 if (WARN_ON(core
->prepare_count
== 0))
728 if (core
->enable_count
== 0) {
729 ret
= clk_core_enable(core
->parent
);
734 trace_clk_enable(core
);
736 if (core
->ops
->enable
)
737 ret
= core
->ops
->enable(core
->hw
);
739 trace_clk_enable_complete(core
);
742 clk_core_disable(core
->parent
);
747 core
->enable_count
++;
752 * clk_enable - ungate a clock
753 * @clk: the clk being ungated
755 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
756 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
757 * if the operation will never sleep. One example is a SoC-internal clk which
758 * is controlled via simple register writes. In the complex case a clk ungate
759 * operation may require a fast and a slow part. It is this reason that
760 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
761 * must be called before clk_enable. Returns 0 on success, -EERROR
764 int clk_enable(struct clk
*clk
)
772 flags
= clk_enable_lock();
773 ret
= clk_core_enable(clk
->core
);
774 clk_enable_unlock(flags
);
778 EXPORT_SYMBOL_GPL(clk_enable
);
780 static int clk_core_round_rate_nolock(struct clk_core
*core
,
781 struct clk_rate_request
*req
)
783 struct clk_core
*parent
;
786 lockdep_assert_held(&prepare_lock
);
791 parent
= core
->parent
;
793 req
->best_parent_hw
= parent
->hw
;
794 req
->best_parent_rate
= parent
->rate
;
796 req
->best_parent_hw
= NULL
;
797 req
->best_parent_rate
= 0;
800 if (core
->ops
->determine_rate
) {
801 return core
->ops
->determine_rate(core
->hw
, req
);
802 } else if (core
->ops
->round_rate
) {
803 rate
= core
->ops
->round_rate(core
->hw
, req
->rate
,
804 &req
->best_parent_rate
);
809 } else if (core
->flags
& CLK_SET_RATE_PARENT
) {
810 return clk_core_round_rate_nolock(parent
, req
);
812 req
->rate
= core
->rate
;
819 * __clk_determine_rate - get the closest rate actually supported by a clock
820 * @hw: determine the rate of this clock
822 * @min_rate: returned rate must be greater than this rate
823 * @max_rate: returned rate must be less than this rate
825 * Useful for clk_ops such as .set_rate and .determine_rate.
827 int __clk_determine_rate(struct clk_hw
*hw
, struct clk_rate_request
*req
)
834 return clk_core_round_rate_nolock(hw
->core
, req
);
836 EXPORT_SYMBOL_GPL(__clk_determine_rate
);
838 unsigned long clk_hw_round_rate(struct clk_hw
*hw
, unsigned long rate
)
841 struct clk_rate_request req
;
843 clk_core_get_boundaries(hw
->core
, &req
.min_rate
, &req
.max_rate
);
846 ret
= clk_core_round_rate_nolock(hw
->core
, &req
);
852 EXPORT_SYMBOL_GPL(clk_hw_round_rate
);
855 * clk_round_rate - round the given rate for a clk
856 * @clk: the clk for which we are rounding a rate
857 * @rate: the rate which is to be rounded
859 * Takes in a rate as input and rounds it to a rate that the clk can actually
860 * use which is then returned. If clk doesn't support round_rate operation
861 * then the parent rate is returned.
863 long clk_round_rate(struct clk
*clk
, unsigned long rate
)
865 struct clk_rate_request req
;
873 clk_core_get_boundaries(clk
->core
, &req
.min_rate
, &req
.max_rate
);
876 ret
= clk_core_round_rate_nolock(clk
->core
, &req
);
877 clk_prepare_unlock();
884 EXPORT_SYMBOL_GPL(clk_round_rate
);
887 * __clk_notify - call clk notifier chain
888 * @core: clk that is changing rate
889 * @msg: clk notifier type (see include/linux/clk.h)
890 * @old_rate: old clk rate
891 * @new_rate: new clk rate
893 * Triggers a notifier call chain on the clk rate-change notification
894 * for 'clk'. Passes a pointer to the struct clk and the previous
895 * and current rates to the notifier callback. Intended to be called by
896 * internal clock code only. Returns NOTIFY_DONE from the last driver
897 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
898 * a driver returns that.
900 static int __clk_notify(struct clk_core
*core
, unsigned long msg
,
901 unsigned long old_rate
, unsigned long new_rate
)
903 struct clk_notifier
*cn
;
904 struct clk_notifier_data cnd
;
905 int ret
= NOTIFY_DONE
;
907 cnd
.old_rate
= old_rate
;
908 cnd
.new_rate
= new_rate
;
910 list_for_each_entry(cn
, &clk_notifier_list
, node
) {
911 if (cn
->clk
->core
== core
) {
913 ret
= srcu_notifier_call_chain(&cn
->notifier_head
, msg
,
922 * __clk_recalc_accuracies
923 * @core: first clk in the subtree
925 * Walks the subtree of clks starting with clk and recalculates accuracies as
926 * it goes. Note that if a clk does not implement the .recalc_accuracy
927 * callback then it is assumed that the clock will take on the accuracy of its
930 static void __clk_recalc_accuracies(struct clk_core
*core
)
932 unsigned long parent_accuracy
= 0;
933 struct clk_core
*child
;
935 lockdep_assert_held(&prepare_lock
);
938 parent_accuracy
= core
->parent
->accuracy
;
940 if (core
->ops
->recalc_accuracy
)
941 core
->accuracy
= core
->ops
->recalc_accuracy(core
->hw
,
944 core
->accuracy
= parent_accuracy
;
946 hlist_for_each_entry(child
, &core
->children
, child_node
)
947 __clk_recalc_accuracies(child
);
950 static long clk_core_get_accuracy(struct clk_core
*core
)
952 unsigned long accuracy
;
955 if (core
&& (core
->flags
& CLK_GET_ACCURACY_NOCACHE
))
956 __clk_recalc_accuracies(core
);
958 accuracy
= __clk_get_accuracy(core
);
959 clk_prepare_unlock();
965 * clk_get_accuracy - return the accuracy of clk
966 * @clk: the clk whose accuracy is being returned
968 * Simply returns the cached accuracy of the clk, unless
969 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
971 * If clk is NULL then returns 0.
973 long clk_get_accuracy(struct clk
*clk
)
978 return clk_core_get_accuracy(clk
->core
);
980 EXPORT_SYMBOL_GPL(clk_get_accuracy
);
982 static unsigned long clk_recalc(struct clk_core
*core
,
983 unsigned long parent_rate
)
985 if (core
->ops
->recalc_rate
)
986 return core
->ops
->recalc_rate(core
->hw
, parent_rate
);
992 * @core: first clk in the subtree
993 * @msg: notification type (see include/linux/clk.h)
995 * Walks the subtree of clks starting with clk and recalculates rates as it
996 * goes. Note that if a clk does not implement the .recalc_rate callback then
997 * it is assumed that the clock will take on the rate of its parent.
999 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1002 static void __clk_recalc_rates(struct clk_core
*core
, unsigned long msg
)
1004 unsigned long old_rate
;
1005 unsigned long parent_rate
= 0;
1006 struct clk_core
*child
;
1008 lockdep_assert_held(&prepare_lock
);
1010 old_rate
= core
->rate
;
1013 parent_rate
= core
->parent
->rate
;
1015 core
->rate
= clk_recalc(core
, parent_rate
);
1018 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1019 * & ABORT_RATE_CHANGE notifiers
1021 if (core
->notifier_count
&& msg
)
1022 __clk_notify(core
, msg
, old_rate
, core
->rate
);
1024 hlist_for_each_entry(child
, &core
->children
, child_node
)
1025 __clk_recalc_rates(child
, msg
);
1028 static unsigned long clk_core_get_rate(struct clk_core
*core
)
1034 if (core
&& (core
->flags
& CLK_GET_RATE_NOCACHE
))
1035 __clk_recalc_rates(core
, 0);
1037 rate
= clk_core_get_rate_nolock(core
);
1038 clk_prepare_unlock();
1044 * clk_get_rate - return the rate of clk
1045 * @clk: the clk whose rate is being returned
1047 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1048 * is set, which means a recalc_rate will be issued.
1049 * If clk is NULL then returns 0.
1051 unsigned long clk_get_rate(struct clk
*clk
)
1056 return clk_core_get_rate(clk
->core
);
1058 EXPORT_SYMBOL_GPL(clk_get_rate
);
1060 static int clk_fetch_parent_index(struct clk_core
*core
,
1061 struct clk_core
*parent
)
1065 if (!core
->parents
) {
1066 core
->parents
= kcalloc(core
->num_parents
,
1067 sizeof(struct clk
*), GFP_KERNEL
);
1073 * find index of new parent clock using cached parent ptrs,
1074 * or if not yet cached, use string name comparison and cache
1075 * them now to avoid future calls to clk_core_lookup.
1077 for (i
= 0; i
< core
->num_parents
; i
++) {
1078 if (core
->parents
[i
] == parent
)
1081 if (core
->parents
[i
])
1084 if (!strcmp(core
->parent_names
[i
], parent
->name
)) {
1085 core
->parents
[i
] = clk_core_lookup(parent
->name
);
1094 * Update the orphan status of @core and all its children.
1096 static void clk_core_update_orphan_status(struct clk_core
*core
, bool is_orphan
)
1098 struct clk_core
*child
;
1100 core
->orphan
= is_orphan
;
1102 hlist_for_each_entry(child
, &core
->children
, child_node
)
1103 clk_core_update_orphan_status(child
, is_orphan
);
1106 static void clk_reparent(struct clk_core
*core
, struct clk_core
*new_parent
)
1108 bool was_orphan
= core
->orphan
;
1110 hlist_del(&core
->child_node
);
1113 bool becomes_orphan
= new_parent
->orphan
;
1115 /* avoid duplicate POST_RATE_CHANGE notifications */
1116 if (new_parent
->new_child
== core
)
1117 new_parent
->new_child
= NULL
;
1119 hlist_add_head(&core
->child_node
, &new_parent
->children
);
1121 if (was_orphan
!= becomes_orphan
)
1122 clk_core_update_orphan_status(core
, becomes_orphan
);
1124 hlist_add_head(&core
->child_node
, &clk_orphan_list
);
1126 clk_core_update_orphan_status(core
, true);
1129 core
->parent
= new_parent
;
1132 static struct clk_core
*__clk_set_parent_before(struct clk_core
*core
,
1133 struct clk_core
*parent
)
1135 unsigned long flags
;
1136 struct clk_core
*old_parent
= core
->parent
;
1139 * Migrate prepare state between parents and prevent race with
1142 * If the clock is not prepared, then a race with
1143 * clk_enable/disable() is impossible since we already have the
1144 * prepare lock (future calls to clk_enable() need to be preceded by
1147 * If the clock is prepared, migrate the prepared state to the new
1148 * parent and also protect against a race with clk_enable() by
1149 * forcing the clock and the new parent on. This ensures that all
1150 * future calls to clk_enable() are practically NOPs with respect to
1151 * hardware and software states.
1153 * See also: Comment for clk_set_parent() below.
1155 if (core
->prepare_count
) {
1156 clk_core_prepare(parent
);
1157 flags
= clk_enable_lock();
1158 clk_core_enable(parent
);
1159 clk_core_enable(core
);
1160 clk_enable_unlock(flags
);
1163 /* update the clk tree topology */
1164 flags
= clk_enable_lock();
1165 clk_reparent(core
, parent
);
1166 clk_enable_unlock(flags
);
1171 static void __clk_set_parent_after(struct clk_core
*core
,
1172 struct clk_core
*parent
,
1173 struct clk_core
*old_parent
)
1175 unsigned long flags
;
1178 * Finish the migration of prepare state and undo the changes done
1179 * for preventing a race with clk_enable().
1181 if (core
->prepare_count
) {
1182 flags
= clk_enable_lock();
1183 clk_core_disable(core
);
1184 clk_core_disable(old_parent
);
1185 clk_enable_unlock(flags
);
1186 clk_core_unprepare(old_parent
);
1190 static int __clk_set_parent(struct clk_core
*core
, struct clk_core
*parent
,
1193 unsigned long flags
;
1195 struct clk_core
*old_parent
;
1197 old_parent
= __clk_set_parent_before(core
, parent
);
1199 trace_clk_set_parent(core
, parent
);
1201 /* change clock input source */
1202 if (parent
&& core
->ops
->set_parent
)
1203 ret
= core
->ops
->set_parent(core
->hw
, p_index
);
1205 trace_clk_set_parent_complete(core
, parent
);
1208 flags
= clk_enable_lock();
1209 clk_reparent(core
, old_parent
);
1210 clk_enable_unlock(flags
);
1212 if (core
->prepare_count
) {
1213 flags
= clk_enable_lock();
1214 clk_core_disable(core
);
1215 clk_core_disable(parent
);
1216 clk_enable_unlock(flags
);
1217 clk_core_unprepare(parent
);
1222 __clk_set_parent_after(core
, parent
, old_parent
);
1228 * __clk_speculate_rates
1229 * @core: first clk in the subtree
1230 * @parent_rate: the "future" rate of clk's parent
1232 * Walks the subtree of clks starting with clk, speculating rates as it
1233 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1235 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1236 * pre-rate change notifications and returns early if no clks in the
1237 * subtree have subscribed to the notifications. Note that if a clk does not
1238 * implement the .recalc_rate callback then it is assumed that the clock will
1239 * take on the rate of its parent.
1241 static int __clk_speculate_rates(struct clk_core
*core
,
1242 unsigned long parent_rate
)
1244 struct clk_core
*child
;
1245 unsigned long new_rate
;
1246 int ret
= NOTIFY_DONE
;
1248 lockdep_assert_held(&prepare_lock
);
1250 new_rate
= clk_recalc(core
, parent_rate
);
1252 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1253 if (core
->notifier_count
)
1254 ret
= __clk_notify(core
, PRE_RATE_CHANGE
, core
->rate
, new_rate
);
1256 if (ret
& NOTIFY_STOP_MASK
) {
1257 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1258 __func__
, core
->name
, ret
);
1262 hlist_for_each_entry(child
, &core
->children
, child_node
) {
1263 ret
= __clk_speculate_rates(child
, new_rate
);
1264 if (ret
& NOTIFY_STOP_MASK
)
1272 static void clk_calc_subtree(struct clk_core
*core
, unsigned long new_rate
,
1273 struct clk_core
*new_parent
, u8 p_index
)
1275 struct clk_core
*child
;
1277 core
->new_rate
= new_rate
;
1278 core
->new_parent
= new_parent
;
1279 core
->new_parent_index
= p_index
;
1280 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1281 core
->new_child
= NULL
;
1282 if (new_parent
&& new_parent
!= core
->parent
)
1283 new_parent
->new_child
= core
;
1285 hlist_for_each_entry(child
, &core
->children
, child_node
) {
1286 child
->new_rate
= clk_recalc(child
, new_rate
);
1287 clk_calc_subtree(child
, child
->new_rate
, NULL
, 0);
1292 * calculate the new rates returning the topmost clock that has to be
1295 static struct clk_core
*clk_calc_new_rates(struct clk_core
*core
,
1298 struct clk_core
*top
= core
;
1299 struct clk_core
*old_parent
, *parent
;
1300 unsigned long best_parent_rate
= 0;
1301 unsigned long new_rate
;
1302 unsigned long min_rate
;
1303 unsigned long max_rate
;
1308 if (IS_ERR_OR_NULL(core
))
1311 /* save parent rate, if it exists */
1312 parent
= old_parent
= core
->parent
;
1314 best_parent_rate
= parent
->rate
;
1316 clk_core_get_boundaries(core
, &min_rate
, &max_rate
);
1318 /* find the closest rate and parent clk/rate */
1319 if (core
->ops
->determine_rate
) {
1320 struct clk_rate_request req
;
1323 req
.min_rate
= min_rate
;
1324 req
.max_rate
= max_rate
;
1326 req
.best_parent_hw
= parent
->hw
;
1327 req
.best_parent_rate
= parent
->rate
;
1329 req
.best_parent_hw
= NULL
;
1330 req
.best_parent_rate
= 0;
1333 ret
= core
->ops
->determine_rate(core
->hw
, &req
);
1337 best_parent_rate
= req
.best_parent_rate
;
1338 new_rate
= req
.rate
;
1339 parent
= req
.best_parent_hw
? req
.best_parent_hw
->core
: NULL
;
1340 } else if (core
->ops
->round_rate
) {
1341 ret
= core
->ops
->round_rate(core
->hw
, rate
,
1347 if (new_rate
< min_rate
|| new_rate
> max_rate
)
1349 } else if (!parent
|| !(core
->flags
& CLK_SET_RATE_PARENT
)) {
1350 /* pass-through clock without adjustable parent */
1351 core
->new_rate
= core
->rate
;
1354 /* pass-through clock with adjustable parent */
1355 top
= clk_calc_new_rates(parent
, rate
);
1356 new_rate
= parent
->new_rate
;
1360 /* some clocks must be gated to change parent */
1361 if (parent
!= old_parent
&&
1362 (core
->flags
& CLK_SET_PARENT_GATE
) && core
->prepare_count
) {
1363 pr_debug("%s: %s not gated but wants to reparent\n",
1364 __func__
, core
->name
);
1368 /* try finding the new parent index */
1369 if (parent
&& core
->num_parents
> 1) {
1370 p_index
= clk_fetch_parent_index(core
, parent
);
1372 pr_debug("%s: clk %s can not be parent of clk %s\n",
1373 __func__
, parent
->name
, core
->name
);
1378 if ((core
->flags
& CLK_SET_RATE_PARENT
) && parent
&&
1379 best_parent_rate
!= parent
->rate
)
1380 top
= clk_calc_new_rates(parent
, best_parent_rate
);
1383 clk_calc_subtree(core
, new_rate
, parent
, p_index
);
1389 * Notify about rate changes in a subtree. Always walk down the whole tree
1390 * so that in case of an error we can walk down the whole tree again and
1393 static struct clk_core
*clk_propagate_rate_change(struct clk_core
*core
,
1394 unsigned long event
)
1396 struct clk_core
*child
, *tmp_clk
, *fail_clk
= NULL
;
1397 int ret
= NOTIFY_DONE
;
1399 if (core
->rate
== core
->new_rate
)
1402 if (core
->notifier_count
) {
1403 ret
= __clk_notify(core
, event
, core
->rate
, core
->new_rate
);
1404 if (ret
& NOTIFY_STOP_MASK
)
1408 hlist_for_each_entry(child
, &core
->children
, child_node
) {
1409 /* Skip children who will be reparented to another clock */
1410 if (child
->new_parent
&& child
->new_parent
!= core
)
1412 tmp_clk
= clk_propagate_rate_change(child
, event
);
1417 /* handle the new child who might not be in core->children yet */
1418 if (core
->new_child
) {
1419 tmp_clk
= clk_propagate_rate_change(core
->new_child
, event
);
1428 * walk down a subtree and set the new rates notifying the rate
1431 static void clk_change_rate(struct clk_core
*core
)
1433 struct clk_core
*child
;
1434 struct hlist_node
*tmp
;
1435 unsigned long old_rate
;
1436 unsigned long best_parent_rate
= 0;
1437 bool skip_set_rate
= false;
1438 struct clk_core
*old_parent
;
1440 old_rate
= core
->rate
;
1442 if (core
->new_parent
)
1443 best_parent_rate
= core
->new_parent
->rate
;
1444 else if (core
->parent
)
1445 best_parent_rate
= core
->parent
->rate
;
1447 if (core
->new_parent
&& core
->new_parent
!= core
->parent
) {
1448 old_parent
= __clk_set_parent_before(core
, core
->new_parent
);
1449 trace_clk_set_parent(core
, core
->new_parent
);
1451 if (core
->ops
->set_rate_and_parent
) {
1452 skip_set_rate
= true;
1453 core
->ops
->set_rate_and_parent(core
->hw
, core
->new_rate
,
1455 core
->new_parent_index
);
1456 } else if (core
->ops
->set_parent
) {
1457 core
->ops
->set_parent(core
->hw
, core
->new_parent_index
);
1460 trace_clk_set_parent_complete(core
, core
->new_parent
);
1461 __clk_set_parent_after(core
, core
->new_parent
, old_parent
);
1464 trace_clk_set_rate(core
, core
->new_rate
);
1466 if (!skip_set_rate
&& core
->ops
->set_rate
)
1467 core
->ops
->set_rate(core
->hw
, core
->new_rate
, best_parent_rate
);
1469 trace_clk_set_rate_complete(core
, core
->new_rate
);
1471 core
->rate
= clk_recalc(core
, best_parent_rate
);
1473 if (core
->notifier_count
&& old_rate
!= core
->rate
)
1474 __clk_notify(core
, POST_RATE_CHANGE
, old_rate
, core
->rate
);
1476 if (core
->flags
& CLK_RECALC_NEW_RATES
)
1477 (void)clk_calc_new_rates(core
, core
->new_rate
);
1480 * Use safe iteration, as change_rate can actually swap parents
1481 * for certain clock types.
1483 hlist_for_each_entry_safe(child
, tmp
, &core
->children
, child_node
) {
1484 /* Skip children who will be reparented to another clock */
1485 if (child
->new_parent
&& child
->new_parent
!= core
)
1487 clk_change_rate(child
);
1490 /* handle the new child who might not be in core->children yet */
1491 if (core
->new_child
)
1492 clk_change_rate(core
->new_child
);
1495 static int clk_core_set_rate_nolock(struct clk_core
*core
,
1496 unsigned long req_rate
)
1498 struct clk_core
*top
, *fail_clk
;
1499 unsigned long rate
= req_rate
;
1505 /* bail early if nothing to do */
1506 if (rate
== clk_core_get_rate_nolock(core
))
1509 if ((core
->flags
& CLK_SET_RATE_GATE
) && core
->prepare_count
)
1512 /* calculate new rates and get the topmost changed clock */
1513 top
= clk_calc_new_rates(core
, rate
);
1517 /* notify that we are about to change rates */
1518 fail_clk
= clk_propagate_rate_change(top
, PRE_RATE_CHANGE
);
1520 pr_debug("%s: failed to set %s rate\n", __func__
,
1522 clk_propagate_rate_change(top
, ABORT_RATE_CHANGE
);
1526 /* change the rates */
1527 clk_change_rate(top
);
1529 core
->req_rate
= req_rate
;
1535 * clk_set_rate - specify a new rate for clk
1536 * @clk: the clk whose rate is being changed
1537 * @rate: the new rate for clk
1539 * In the simplest case clk_set_rate will only adjust the rate of clk.
1541 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1542 * propagate up to clk's parent; whether or not this happens depends on the
1543 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1544 * after calling .round_rate then upstream parent propagation is ignored. If
1545 * *parent_rate comes back with a new rate for clk's parent then we propagate
1546 * up to clk's parent and set its rate. Upward propagation will continue
1547 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1548 * .round_rate stops requesting changes to clk's parent_rate.
1550 * Rate changes are accomplished via tree traversal that also recalculates the
1551 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
1553 * Returns 0 on success, -EERROR otherwise.
1555 int clk_set_rate(struct clk
*clk
, unsigned long rate
)
1562 /* prevent racing with updates to the clock topology */
1565 ret
= clk_core_set_rate_nolock(clk
->core
, rate
);
1567 clk_prepare_unlock();
1571 EXPORT_SYMBOL_GPL(clk_set_rate
);
1574 * clk_set_rate_range - set a rate range for a clock source
1575 * @clk: clock source
1576 * @min: desired minimum clock rate in Hz, inclusive
1577 * @max: desired maximum clock rate in Hz, inclusive
1579 * Returns success (0) or negative errno.
1581 int clk_set_rate_range(struct clk
*clk
, unsigned long min
, unsigned long max
)
1589 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
1590 __func__
, clk
->core
->name
, clk
->dev_id
, clk
->con_id
,
1597 if (min
!= clk
->min_rate
|| max
!= clk
->max_rate
) {
1598 clk
->min_rate
= min
;
1599 clk
->max_rate
= max
;
1600 ret
= clk_core_set_rate_nolock(clk
->core
, clk
->core
->req_rate
);
1603 clk_prepare_unlock();
1607 EXPORT_SYMBOL_GPL(clk_set_rate_range
);
1610 * clk_set_min_rate - set a minimum clock rate for a clock source
1611 * @clk: clock source
1612 * @rate: desired minimum clock rate in Hz, inclusive
1614 * Returns success (0) or negative errno.
1616 int clk_set_min_rate(struct clk
*clk
, unsigned long rate
)
1621 return clk_set_rate_range(clk
, rate
, clk
->max_rate
);
1623 EXPORT_SYMBOL_GPL(clk_set_min_rate
);
1626 * clk_set_max_rate - set a maximum clock rate for a clock source
1627 * @clk: clock source
1628 * @rate: desired maximum clock rate in Hz, inclusive
1630 * Returns success (0) or negative errno.
1632 int clk_set_max_rate(struct clk
*clk
, unsigned long rate
)
1637 return clk_set_rate_range(clk
, clk
->min_rate
, rate
);
1639 EXPORT_SYMBOL_GPL(clk_set_max_rate
);
1642 * clk_get_parent - return the parent of a clk
1643 * @clk: the clk whose parent gets returned
1645 * Simply returns clk->parent. Returns NULL if clk is NULL.
1647 struct clk
*clk_get_parent(struct clk
*clk
)
1655 /* TODO: Create a per-user clk and change callers to call clk_put */
1656 parent
= !clk
->core
->parent
? NULL
: clk
->core
->parent
->hw
->clk
;
1657 clk_prepare_unlock();
1661 EXPORT_SYMBOL_GPL(clk_get_parent
);
1664 * .get_parent is mandatory for clocks with multiple possible parents. It is
1665 * optional for single-parent clocks. Always call .get_parent if it is
1666 * available and WARN if it is missing for multi-parent clocks.
1668 * For single-parent clocks without .get_parent, first check to see if the
1669 * .parents array exists, and if so use it to avoid an expensive tree
1670 * traversal. If .parents does not exist then walk the tree.
1672 static struct clk_core
*__clk_init_parent(struct clk_core
*core
)
1674 struct clk_core
*ret
= NULL
;
1677 /* handle the trivial cases */
1679 if (!core
->num_parents
)
1682 if (core
->num_parents
== 1) {
1683 if (IS_ERR_OR_NULL(core
->parent
))
1684 core
->parent
= clk_core_lookup(core
->parent_names
[0]);
1689 if (!core
->ops
->get_parent
) {
1690 WARN(!core
->ops
->get_parent
,
1691 "%s: multi-parent clocks must implement .get_parent\n",
1697 * Do our best to cache parent clocks in core->parents. This prevents
1698 * unnecessary and expensive lookups. We don't set core->parent here;
1699 * that is done by the calling function.
1702 index
= core
->ops
->get_parent(core
->hw
);
1706 kcalloc(core
->num_parents
, sizeof(struct clk
*),
1709 ret
= clk_core_get_parent_by_index(core
, index
);
1715 static void clk_core_reparent(struct clk_core
*core
,
1716 struct clk_core
*new_parent
)
1718 clk_reparent(core
, new_parent
);
1719 __clk_recalc_accuracies(core
);
1720 __clk_recalc_rates(core
, POST_RATE_CHANGE
);
1723 void clk_hw_reparent(struct clk_hw
*hw
, struct clk_hw
*new_parent
)
1728 clk_core_reparent(hw
->core
, !new_parent
? NULL
: new_parent
->core
);
1732 * clk_has_parent - check if a clock is a possible parent for another
1733 * @clk: clock source
1734 * @parent: parent clock source
1736 * This function can be used in drivers that need to check that a clock can be
1737 * the parent of another without actually changing the parent.
1739 * Returns true if @parent is a possible parent for @clk, false otherwise.
1741 bool clk_has_parent(struct clk
*clk
, struct clk
*parent
)
1743 struct clk_core
*core
, *parent_core
;
1746 /* NULL clocks should be nops, so return success if either is NULL. */
1747 if (!clk
|| !parent
)
1751 parent_core
= parent
->core
;
1753 /* Optimize for the case where the parent is already the parent. */
1754 if (core
->parent
== parent_core
)
1757 for (i
= 0; i
< core
->num_parents
; i
++)
1758 if (strcmp(core
->parent_names
[i
], parent_core
->name
) == 0)
1763 EXPORT_SYMBOL_GPL(clk_has_parent
);
1765 static int clk_core_set_parent(struct clk_core
*core
, struct clk_core
*parent
)
1769 unsigned long p_rate
= 0;
1774 /* prevent racing with updates to the clock topology */
1777 if (core
->parent
== parent
)
1780 /* verify ops for for multi-parent clks */
1781 if ((core
->num_parents
> 1) && (!core
->ops
->set_parent
)) {
1786 /* check that we are allowed to re-parent if the clock is in use */
1787 if ((core
->flags
& CLK_SET_PARENT_GATE
) && core
->prepare_count
) {
1792 /* try finding the new parent index */
1794 p_index
= clk_fetch_parent_index(core
, parent
);
1795 p_rate
= parent
->rate
;
1797 pr_debug("%s: clk %s can not be parent of clk %s\n",
1798 __func__
, parent
->name
, core
->name
);
1804 /* propagate PRE_RATE_CHANGE notifications */
1805 ret
= __clk_speculate_rates(core
, p_rate
);
1807 /* abort if a driver objects */
1808 if (ret
& NOTIFY_STOP_MASK
)
1811 /* do the re-parent */
1812 ret
= __clk_set_parent(core
, parent
, p_index
);
1814 /* propagate rate an accuracy recalculation accordingly */
1816 __clk_recalc_rates(core
, ABORT_RATE_CHANGE
);
1818 __clk_recalc_rates(core
, POST_RATE_CHANGE
);
1819 __clk_recalc_accuracies(core
);
1823 clk_prepare_unlock();
1829 * clk_set_parent - switch the parent of a mux clk
1830 * @clk: the mux clk whose input we are switching
1831 * @parent: the new input to clk
1833 * Re-parent clk to use parent as its new input source. If clk is in
1834 * prepared state, the clk will get enabled for the duration of this call. If
1835 * that's not acceptable for a specific clk (Eg: the consumer can't handle
1836 * that, the reparenting is glitchy in hardware, etc), use the
1837 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
1839 * After successfully changing clk's parent clk_set_parent will update the
1840 * clk topology, sysfs topology and propagate rate recalculation via
1841 * __clk_recalc_rates.
1843 * Returns 0 on success, -EERROR otherwise.
1845 int clk_set_parent(struct clk
*clk
, struct clk
*parent
)
1850 return clk_core_set_parent(clk
->core
, parent
? parent
->core
: NULL
);
1852 EXPORT_SYMBOL_GPL(clk_set_parent
);
1855 * clk_set_phase - adjust the phase shift of a clock signal
1856 * @clk: clock signal source
1857 * @degrees: number of degrees the signal is shifted
1859 * Shifts the phase of a clock signal by the specified
1860 * degrees. Returns 0 on success, -EERROR otherwise.
1862 * This function makes no distinction about the input or reference
1863 * signal that we adjust the clock signal phase against. For example
1864 * phase locked-loop clock signal generators we may shift phase with
1865 * respect to feedback clock signal input, but for other cases the
1866 * clock phase may be shifted with respect to some other, unspecified
1869 * Additionally the concept of phase shift does not propagate through
1870 * the clock tree hierarchy, which sets it apart from clock rates and
1871 * clock accuracy. A parent clock phase attribute does not have an
1872 * impact on the phase attribute of a child clock.
1874 int clk_set_phase(struct clk
*clk
, int degrees
)
1881 /* sanity check degrees */
1888 trace_clk_set_phase(clk
->core
, degrees
);
1890 if (clk
->core
->ops
->set_phase
)
1891 ret
= clk
->core
->ops
->set_phase(clk
->core
->hw
, degrees
);
1893 trace_clk_set_phase_complete(clk
->core
, degrees
);
1896 clk
->core
->phase
= degrees
;
1898 clk_prepare_unlock();
1902 EXPORT_SYMBOL_GPL(clk_set_phase
);
1904 static int clk_core_get_phase(struct clk_core
*core
)
1910 clk_prepare_unlock();
1916 * clk_get_phase - return the phase shift of a clock signal
1917 * @clk: clock signal source
1919 * Returns the phase shift of a clock node in degrees, otherwise returns
1922 int clk_get_phase(struct clk
*clk
)
1927 return clk_core_get_phase(clk
->core
);
1929 EXPORT_SYMBOL_GPL(clk_get_phase
);
1932 * clk_is_match - check if two clk's point to the same hardware clock
1933 * @p: clk compared against q
1934 * @q: clk compared against p
1936 * Returns true if the two struct clk pointers both point to the same hardware
1937 * clock node. Put differently, returns true if struct clk *p and struct clk *q
1938 * share the same struct clk_core object.
1940 * Returns false otherwise. Note that two NULL clks are treated as matching.
1942 bool clk_is_match(const struct clk
*p
, const struct clk
*q
)
1944 /* trivial case: identical struct clk's or both NULL */
1948 /* true if clk->core pointers match. Avoid derefing garbage */
1949 if (!IS_ERR_OR_NULL(p
) && !IS_ERR_OR_NULL(q
))
1950 if (p
->core
== q
->core
)
1955 EXPORT_SYMBOL_GPL(clk_is_match
);
1957 /*** debugfs support ***/
1959 #ifdef CONFIG_DEBUG_FS
1960 #include <linux/debugfs.h>
1962 static struct dentry
*rootdir
;
1963 static int inited
= 0;
1964 static DEFINE_MUTEX(clk_debug_lock
);
1965 static HLIST_HEAD(clk_debug_list
);
1967 static struct hlist_head
*all_lists
[] = {
1973 static struct hlist_head
*orphan_list
[] = {
1978 static void clk_summary_show_one(struct seq_file
*s
, struct clk_core
*c
,
1984 seq_printf(s
, "%*s%-*s %11d %12d %11lu %10lu %-3d\n",
1986 30 - level
* 3, c
->name
,
1987 c
->enable_count
, c
->prepare_count
, clk_core_get_rate(c
),
1988 clk_core_get_accuracy(c
), clk_core_get_phase(c
));
1991 static void clk_summary_show_subtree(struct seq_file
*s
, struct clk_core
*c
,
1994 struct clk_core
*child
;
1999 clk_summary_show_one(s
, c
, level
);
2001 hlist_for_each_entry(child
, &c
->children
, child_node
)
2002 clk_summary_show_subtree(s
, child
, level
+ 1);
2005 static int clk_summary_show(struct seq_file
*s
, void *data
)
2008 struct hlist_head
**lists
= (struct hlist_head
**)s
->private;
2010 seq_puts(s
, " clock enable_cnt prepare_cnt rate accuracy phase\n");
2011 seq_puts(s
, "----------------------------------------------------------------------------------------\n");
2015 for (; *lists
; lists
++)
2016 hlist_for_each_entry(c
, *lists
, child_node
)
2017 clk_summary_show_subtree(s
, c
, 0);
2019 clk_prepare_unlock();
2025 static int clk_summary_open(struct inode
*inode
, struct file
*file
)
2027 return single_open(file
, clk_summary_show
, inode
->i_private
);
2030 static const struct file_operations clk_summary_fops
= {
2031 .open
= clk_summary_open
,
2033 .llseek
= seq_lseek
,
2034 .release
= single_release
,
2037 static void clk_dump_one(struct seq_file
*s
, struct clk_core
*c
, int level
)
2042 /* This should be JSON format, i.e. elements separated with a comma */
2043 seq_printf(s
, "\"%s\": { ", c
->name
);
2044 seq_printf(s
, "\"enable_count\": %d,", c
->enable_count
);
2045 seq_printf(s
, "\"prepare_count\": %d,", c
->prepare_count
);
2046 seq_printf(s
, "\"rate\": %lu,", clk_core_get_rate(c
));
2047 seq_printf(s
, "\"accuracy\": %lu,", clk_core_get_accuracy(c
));
2048 seq_printf(s
, "\"phase\": %d", clk_core_get_phase(c
));
2051 static void clk_dump_subtree(struct seq_file
*s
, struct clk_core
*c
, int level
)
2053 struct clk_core
*child
;
2058 clk_dump_one(s
, c
, level
);
2060 hlist_for_each_entry(child
, &c
->children
, child_node
) {
2062 clk_dump_subtree(s
, child
, level
+ 1);
2068 static int clk_dump(struct seq_file
*s
, void *data
)
2071 bool first_node
= true;
2072 struct hlist_head
**lists
= (struct hlist_head
**)s
->private;
2078 for (; *lists
; lists
++) {
2079 hlist_for_each_entry(c
, *lists
, child_node
) {
2083 clk_dump_subtree(s
, c
, 0);
2087 clk_prepare_unlock();
2094 static int clk_dump_open(struct inode
*inode
, struct file
*file
)
2096 return single_open(file
, clk_dump
, inode
->i_private
);
2099 static const struct file_operations clk_dump_fops
= {
2100 .open
= clk_dump_open
,
2102 .llseek
= seq_lseek
,
2103 .release
= single_release
,
2106 static int clk_debug_create_one(struct clk_core
*core
, struct dentry
*pdentry
)
2111 if (!core
|| !pdentry
) {
2116 d
= debugfs_create_dir(core
->name
, pdentry
);
2122 d
= debugfs_create_u32("clk_rate", S_IRUGO
, core
->dentry
,
2123 (u32
*)&core
->rate
);
2127 d
= debugfs_create_u32("clk_accuracy", S_IRUGO
, core
->dentry
,
2128 (u32
*)&core
->accuracy
);
2132 d
= debugfs_create_u32("clk_phase", S_IRUGO
, core
->dentry
,
2133 (u32
*)&core
->phase
);
2137 d
= debugfs_create_x32("clk_flags", S_IRUGO
, core
->dentry
,
2138 (u32
*)&core
->flags
);
2142 d
= debugfs_create_u32("clk_prepare_count", S_IRUGO
, core
->dentry
,
2143 (u32
*)&core
->prepare_count
);
2147 d
= debugfs_create_u32("clk_enable_count", S_IRUGO
, core
->dentry
,
2148 (u32
*)&core
->enable_count
);
2152 d
= debugfs_create_u32("clk_notifier_count", S_IRUGO
, core
->dentry
,
2153 (u32
*)&core
->notifier_count
);
2157 if (core
->ops
->debug_init
) {
2158 ret
= core
->ops
->debug_init(core
->hw
, core
->dentry
);
2167 debugfs_remove_recursive(core
->dentry
);
2168 core
->dentry
= NULL
;
2174 * clk_debug_register - add a clk node to the debugfs clk directory
2175 * @core: the clk being added to the debugfs clk directory
2177 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
2178 * initialized. Otherwise it bails out early since the debugfs clk directory
2179 * will be created lazily by clk_debug_init as part of a late_initcall.
2181 static int clk_debug_register(struct clk_core
*core
)
2185 mutex_lock(&clk_debug_lock
);
2186 hlist_add_head(&core
->debug_node
, &clk_debug_list
);
2191 ret
= clk_debug_create_one(core
, rootdir
);
2193 mutex_unlock(&clk_debug_lock
);
2199 * clk_debug_unregister - remove a clk node from the debugfs clk directory
2200 * @core: the clk being removed from the debugfs clk directory
2202 * Dynamically removes a clk and all its child nodes from the
2203 * debugfs clk directory if clk->dentry points to debugfs created by
2204 * clk_debug_register in __clk_init.
2206 static void clk_debug_unregister(struct clk_core
*core
)
2208 mutex_lock(&clk_debug_lock
);
2209 hlist_del_init(&core
->debug_node
);
2210 debugfs_remove_recursive(core
->dentry
);
2211 core
->dentry
= NULL
;
2212 mutex_unlock(&clk_debug_lock
);
2215 struct dentry
*clk_debugfs_add_file(struct clk_hw
*hw
, char *name
, umode_t mode
,
2216 void *data
, const struct file_operations
*fops
)
2218 struct dentry
*d
= NULL
;
2220 if (hw
->core
->dentry
)
2221 d
= debugfs_create_file(name
, mode
, hw
->core
->dentry
, data
,
2226 EXPORT_SYMBOL_GPL(clk_debugfs_add_file
);
2229 * clk_debug_init - lazily populate the debugfs clk directory
2231 * clks are often initialized very early during boot before memory can be
2232 * dynamically allocated and well before debugfs is setup. This function
2233 * populates the debugfs clk directory once at boot-time when we know that
2234 * debugfs is setup. It should only be called once at boot-time, all other clks
2235 * added dynamically will be done so with clk_debug_register.
2237 static int __init
clk_debug_init(void)
2239 struct clk_core
*core
;
2242 rootdir
= debugfs_create_dir("clk", NULL
);
2247 d
= debugfs_create_file("clk_summary", S_IRUGO
, rootdir
, &all_lists
,
2252 d
= debugfs_create_file("clk_dump", S_IRUGO
, rootdir
, &all_lists
,
2257 d
= debugfs_create_file("clk_orphan_summary", S_IRUGO
, rootdir
,
2258 &orphan_list
, &clk_summary_fops
);
2262 d
= debugfs_create_file("clk_orphan_dump", S_IRUGO
, rootdir
,
2263 &orphan_list
, &clk_dump_fops
);
2267 mutex_lock(&clk_debug_lock
);
2268 hlist_for_each_entry(core
, &clk_debug_list
, debug_node
)
2269 clk_debug_create_one(core
, rootdir
);
2272 mutex_unlock(&clk_debug_lock
);
2276 late_initcall(clk_debug_init
);
2278 static inline int clk_debug_register(struct clk_core
*core
) { return 0; }
2279 static inline void clk_debug_reparent(struct clk_core
*core
,
2280 struct clk_core
*new_parent
)
2283 static inline void clk_debug_unregister(struct clk_core
*core
)
2289 * __clk_init - initialize the data structures in a struct clk
2290 * @dev: device initializing this clk, placeholder for now
2291 * @clk: clk being initialized
2293 * Initializes the lists in struct clk_core, queries the hardware for the
2294 * parent and rate and sets them both.
2296 static int __clk_init(struct device
*dev
, struct clk
*clk_user
)
2299 struct clk_core
*orphan
;
2300 struct hlist_node
*tmp2
;
2301 struct clk_core
*core
;
2307 core
= clk_user
->core
;
2311 /* check to see if a clock with this name is already registered */
2312 if (clk_core_lookup(core
->name
)) {
2313 pr_debug("%s: clk %s already initialized\n",
2314 __func__
, core
->name
);
2319 /* check that clk_ops are sane. See Documentation/clk.txt */
2320 if (core
->ops
->set_rate
&&
2321 !((core
->ops
->round_rate
|| core
->ops
->determine_rate
) &&
2322 core
->ops
->recalc_rate
)) {
2323 pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
2324 __func__
, core
->name
);
2329 if (core
->ops
->set_parent
&& !core
->ops
->get_parent
) {
2330 pr_warning("%s: %s must implement .get_parent & .set_parent\n",
2331 __func__
, core
->name
);
2336 if (core
->ops
->set_rate_and_parent
&&
2337 !(core
->ops
->set_parent
&& core
->ops
->set_rate
)) {
2338 pr_warn("%s: %s must implement .set_parent & .set_rate\n",
2339 __func__
, core
->name
);
2344 /* throw a WARN if any entries in parent_names are NULL */
2345 for (i
= 0; i
< core
->num_parents
; i
++)
2346 WARN(!core
->parent_names
[i
],
2347 "%s: invalid NULL in %s's .parent_names\n",
2348 __func__
, core
->name
);
2351 * Allocate an array of struct clk *'s to avoid unnecessary string
2352 * look-ups of clk's possible parents. This can fail for clocks passed
2353 * in to clk_init during early boot; thus any access to core->parents[]
2354 * must always check for a NULL pointer and try to populate it if
2357 * If core->parents is not NULL we skip this entire block. This allows
2358 * for clock drivers to statically initialize core->parents.
2360 if (core
->num_parents
> 1 && !core
->parents
) {
2361 core
->parents
= kcalloc(core
->num_parents
, sizeof(struct clk
*),
2364 * clk_core_lookup returns NULL for parents that have not been
2365 * clk_init'd; thus any access to clk->parents[] must check
2366 * for a NULL pointer. We can always perform lazy lookups for
2367 * missing parents later on.
2370 for (i
= 0; i
< core
->num_parents
; i
++)
2372 clk_core_lookup(core
->parent_names
[i
]);
2375 core
->parent
= __clk_init_parent(core
);
2378 * Populate core->parent if parent has already been __clk_init'd. If
2379 * parent has not yet been __clk_init'd then place clk in the orphan
2380 * list. If clk has set the CLK_IS_ROOT flag then place it in the root
2383 * Every time a new clk is clk_init'd then we walk the list of orphan
2384 * clocks and re-parent any that are children of the clock currently
2388 hlist_add_head(&core
->child_node
,
2389 &core
->parent
->children
);
2390 core
->orphan
= core
->parent
->orphan
;
2391 } else if (core
->flags
& CLK_IS_ROOT
) {
2392 hlist_add_head(&core
->child_node
, &clk_root_list
);
2393 core
->orphan
= false;
2395 hlist_add_head(&core
->child_node
, &clk_orphan_list
);
2396 core
->orphan
= true;
2400 * Set clk's accuracy. The preferred method is to use
2401 * .recalc_accuracy. For simple clocks and lazy developers the default
2402 * fallback is to use the parent's accuracy. If a clock doesn't have a
2403 * parent (or is orphaned) then accuracy is set to zero (perfect
2406 if (core
->ops
->recalc_accuracy
)
2407 core
->accuracy
= core
->ops
->recalc_accuracy(core
->hw
,
2408 __clk_get_accuracy(core
->parent
));
2409 else if (core
->parent
)
2410 core
->accuracy
= core
->parent
->accuracy
;
2416 * Since a phase is by definition relative to its parent, just
2417 * query the current clock phase, or just assume it's in phase.
2419 if (core
->ops
->get_phase
)
2420 core
->phase
= core
->ops
->get_phase(core
->hw
);
2425 * Set clk's rate. The preferred method is to use .recalc_rate. For
2426 * simple clocks and lazy developers the default fallback is to use the
2427 * parent's rate. If a clock doesn't have a parent (or is orphaned)
2428 * then rate is set to zero.
2430 if (core
->ops
->recalc_rate
)
2431 rate
= core
->ops
->recalc_rate(core
->hw
,
2432 clk_core_get_rate_nolock(core
->parent
));
2433 else if (core
->parent
)
2434 rate
= core
->parent
->rate
;
2437 core
->rate
= core
->req_rate
= rate
;
2440 * walk the list of orphan clocks and reparent any that are children of
2443 hlist_for_each_entry_safe(orphan
, tmp2
, &clk_orphan_list
, child_node
) {
2444 if (orphan
->num_parents
&& orphan
->ops
->get_parent
) {
2445 i
= orphan
->ops
->get_parent(orphan
->hw
);
2446 if (!strcmp(core
->name
, orphan
->parent_names
[i
]))
2447 clk_core_reparent(orphan
, core
);
2451 for (i
= 0; i
< orphan
->num_parents
; i
++)
2452 if (!strcmp(core
->name
, orphan
->parent_names
[i
])) {
2453 clk_core_reparent(orphan
, core
);
2459 * optional platform-specific magic
2461 * The .init callback is not used by any of the basic clock types, but
2462 * exists for weird hardware that must perform initialization magic.
2463 * Please consider other ways of solving initialization problems before
2464 * using this callback, as its use is discouraged.
2466 if (core
->ops
->init
)
2467 core
->ops
->init(core
->hw
);
2469 kref_init(&core
->ref
);
2471 clk_prepare_unlock();
2474 clk_debug_register(core
);
2479 struct clk
*__clk_create_clk(struct clk_hw
*hw
, const char *dev_id
,
2484 /* This is to allow this function to be chained to others */
2485 if (!hw
|| IS_ERR(hw
))
2486 return (struct clk
*) hw
;
2488 clk
= kzalloc(sizeof(*clk
), GFP_KERNEL
);
2490 return ERR_PTR(-ENOMEM
);
2492 clk
->core
= hw
->core
;
2493 clk
->dev_id
= dev_id
;
2494 clk
->con_id
= con_id
;
2495 clk
->max_rate
= ULONG_MAX
;
2498 hlist_add_head(&clk
->clks_node
, &hw
->core
->clks
);
2499 clk_prepare_unlock();
2504 void __clk_free_clk(struct clk
*clk
)
2507 hlist_del(&clk
->clks_node
);
2508 clk_prepare_unlock();
2514 * clk_register - allocate a new clock, register it and return an opaque cookie
2515 * @dev: device that is registering this clock
2516 * @hw: link to hardware-specific clock data
2518 * clk_register is the primary interface for populating the clock tree with new
2519 * clock nodes. It returns a pointer to the newly allocated struct clk which
2520 * cannot be dereferenced by driver code but may be used in conjunction with the
2521 * rest of the clock API. In the event of an error clk_register will return an
2522 * error code; drivers must test for an error code after calling clk_register.
2524 struct clk
*clk_register(struct device
*dev
, struct clk_hw
*hw
)
2527 struct clk_core
*core
;
2529 core
= kzalloc(sizeof(*core
), GFP_KERNEL
);
2535 core
->name
= kstrdup_const(hw
->init
->name
, GFP_KERNEL
);
2540 core
->ops
= hw
->init
->ops
;
2541 if (dev
&& dev
->driver
)
2542 core
->owner
= dev
->driver
->owner
;
2544 core
->flags
= hw
->init
->flags
;
2545 core
->num_parents
= hw
->init
->num_parents
;
2547 core
->max_rate
= ULONG_MAX
;
2550 /* allocate local copy in case parent_names is __initdata */
2551 core
->parent_names
= kcalloc(core
->num_parents
, sizeof(char *),
2554 if (!core
->parent_names
) {
2556 goto fail_parent_names
;
2560 /* copy each string name in case parent_names is __initdata */
2561 for (i
= 0; i
< core
->num_parents
; i
++) {
2562 core
->parent_names
[i
] = kstrdup_const(hw
->init
->parent_names
[i
],
2564 if (!core
->parent_names
[i
]) {
2566 goto fail_parent_names_copy
;
2570 INIT_HLIST_HEAD(&core
->clks
);
2572 hw
->clk
= __clk_create_clk(hw
, NULL
, NULL
);
2573 if (IS_ERR(hw
->clk
)) {
2574 ret
= PTR_ERR(hw
->clk
);
2575 goto fail_parent_names_copy
;
2578 ret
= __clk_init(dev
, hw
->clk
);
2582 __clk_free_clk(hw
->clk
);
2585 fail_parent_names_copy
:
2587 kfree_const(core
->parent_names
[i
]);
2588 kfree(core
->parent_names
);
2590 kfree_const(core
->name
);
2594 return ERR_PTR(ret
);
2596 EXPORT_SYMBOL_GPL(clk_register
);
2598 /* Free memory allocated for a clock. */
2599 static void __clk_release(struct kref
*ref
)
2601 struct clk_core
*core
= container_of(ref
, struct clk_core
, ref
);
2602 int i
= core
->num_parents
;
2604 lockdep_assert_held(&prepare_lock
);
2606 kfree(core
->parents
);
2608 kfree_const(core
->parent_names
[i
]);
2610 kfree(core
->parent_names
);
2611 kfree_const(core
->name
);
2616 * Empty clk_ops for unregistered clocks. These are used temporarily
2617 * after clk_unregister() was called on a clock and until last clock
2618 * consumer calls clk_put() and the struct clk object is freed.
2620 static int clk_nodrv_prepare_enable(struct clk_hw
*hw
)
2625 static void clk_nodrv_disable_unprepare(struct clk_hw
*hw
)
2630 static int clk_nodrv_set_rate(struct clk_hw
*hw
, unsigned long rate
,
2631 unsigned long parent_rate
)
2636 static int clk_nodrv_set_parent(struct clk_hw
*hw
, u8 index
)
2641 static const struct clk_ops clk_nodrv_ops
= {
2642 .enable
= clk_nodrv_prepare_enable
,
2643 .disable
= clk_nodrv_disable_unprepare
,
2644 .prepare
= clk_nodrv_prepare_enable
,
2645 .unprepare
= clk_nodrv_disable_unprepare
,
2646 .set_rate
= clk_nodrv_set_rate
,
2647 .set_parent
= clk_nodrv_set_parent
,
2651 * clk_unregister - unregister a currently registered clock
2652 * @clk: clock to unregister
2654 void clk_unregister(struct clk
*clk
)
2656 unsigned long flags
;
2658 if (!clk
|| WARN_ON_ONCE(IS_ERR(clk
)))
2661 clk_debug_unregister(clk
->core
);
2665 if (clk
->core
->ops
== &clk_nodrv_ops
) {
2666 pr_err("%s: unregistered clock: %s\n", __func__
,
2671 * Assign empty clock ops for consumers that might still hold
2672 * a reference to this clock.
2674 flags
= clk_enable_lock();
2675 clk
->core
->ops
= &clk_nodrv_ops
;
2676 clk_enable_unlock(flags
);
2678 if (!hlist_empty(&clk
->core
->children
)) {
2679 struct clk_core
*child
;
2680 struct hlist_node
*t
;
2682 /* Reparent all children to the orphan list. */
2683 hlist_for_each_entry_safe(child
, t
, &clk
->core
->children
,
2685 clk_core_set_parent(child
, NULL
);
2688 hlist_del_init(&clk
->core
->child_node
);
2690 if (clk
->core
->prepare_count
)
2691 pr_warn("%s: unregistering prepared clock: %s\n",
2692 __func__
, clk
->core
->name
);
2693 kref_put(&clk
->core
->ref
, __clk_release
);
2695 clk_prepare_unlock();
2697 EXPORT_SYMBOL_GPL(clk_unregister
);
2699 static void devm_clk_release(struct device
*dev
, void *res
)
2701 clk_unregister(*(struct clk
**)res
);
2705 * devm_clk_register - resource managed clk_register()
2706 * @dev: device that is registering this clock
2707 * @hw: link to hardware-specific clock data
2709 * Managed clk_register(). Clocks returned from this function are
2710 * automatically clk_unregister()ed on driver detach. See clk_register() for
2713 struct clk
*devm_clk_register(struct device
*dev
, struct clk_hw
*hw
)
2718 clkp
= devres_alloc(devm_clk_release
, sizeof(*clkp
), GFP_KERNEL
);
2720 return ERR_PTR(-ENOMEM
);
2722 clk
= clk_register(dev
, hw
);
2725 devres_add(dev
, clkp
);
2732 EXPORT_SYMBOL_GPL(devm_clk_register
);
2734 static int devm_clk_match(struct device
*dev
, void *res
, void *data
)
2736 struct clk
*c
= res
;
2743 * devm_clk_unregister - resource managed clk_unregister()
2744 * @clk: clock to unregister
2746 * Deallocate a clock allocated with devm_clk_register(). Normally
2747 * this function will not need to be called and the resource management
2748 * code will ensure that the resource is freed.
2750 void devm_clk_unregister(struct device
*dev
, struct clk
*clk
)
2752 WARN_ON(devres_release(dev
, devm_clk_release
, devm_clk_match
, clk
));
2754 EXPORT_SYMBOL_GPL(devm_clk_unregister
);
2759 int __clk_get(struct clk
*clk
)
2761 struct clk_core
*core
= !clk
? NULL
: clk
->core
;
2764 if (!try_module_get(core
->owner
))
2767 kref_get(&core
->ref
);
2772 void __clk_put(struct clk
*clk
)
2774 struct module
*owner
;
2776 if (!clk
|| WARN_ON_ONCE(IS_ERR(clk
)))
2781 hlist_del(&clk
->clks_node
);
2782 if (clk
->min_rate
> clk
->core
->req_rate
||
2783 clk
->max_rate
< clk
->core
->req_rate
)
2784 clk_core_set_rate_nolock(clk
->core
, clk
->core
->req_rate
);
2786 owner
= clk
->core
->owner
;
2787 kref_put(&clk
->core
->ref
, __clk_release
);
2789 clk_prepare_unlock();
2796 /*** clk rate change notifiers ***/
2799 * clk_notifier_register - add a clk rate change notifier
2800 * @clk: struct clk * to watch
2801 * @nb: struct notifier_block * with callback info
2803 * Request notification when clk's rate changes. This uses an SRCU
2804 * notifier because we want it to block and notifier unregistrations are
2805 * uncommon. The callbacks associated with the notifier must not
2806 * re-enter into the clk framework by calling any top-level clk APIs;
2807 * this will cause a nested prepare_lock mutex.
2809 * In all notification cases cases (pre, post and abort rate change) the
2810 * original clock rate is passed to the callback via struct
2811 * clk_notifier_data.old_rate and the new frequency is passed via struct
2812 * clk_notifier_data.new_rate.
2814 * clk_notifier_register() must be called from non-atomic context.
2815 * Returns -EINVAL if called with null arguments, -ENOMEM upon
2816 * allocation failure; otherwise, passes along the return value of
2817 * srcu_notifier_chain_register().
2819 int clk_notifier_register(struct clk
*clk
, struct notifier_block
*nb
)
2821 struct clk_notifier
*cn
;
2829 /* search the list of notifiers for this clk */
2830 list_for_each_entry(cn
, &clk_notifier_list
, node
)
2834 /* if clk wasn't in the notifier list, allocate new clk_notifier */
2835 if (cn
->clk
!= clk
) {
2836 cn
= kzalloc(sizeof(struct clk_notifier
), GFP_KERNEL
);
2841 srcu_init_notifier_head(&cn
->notifier_head
);
2843 list_add(&cn
->node
, &clk_notifier_list
);
2846 ret
= srcu_notifier_chain_register(&cn
->notifier_head
, nb
);
2848 clk
->core
->notifier_count
++;
2851 clk_prepare_unlock();
2855 EXPORT_SYMBOL_GPL(clk_notifier_register
);
2858 * clk_notifier_unregister - remove a clk rate change notifier
2859 * @clk: struct clk *
2860 * @nb: struct notifier_block * with callback info
2862 * Request no further notification for changes to 'clk' and frees memory
2863 * allocated in clk_notifier_register.
2865 * Returns -EINVAL if called with null arguments; otherwise, passes
2866 * along the return value of srcu_notifier_chain_unregister().
2868 int clk_notifier_unregister(struct clk
*clk
, struct notifier_block
*nb
)
2870 struct clk_notifier
*cn
= NULL
;
2878 list_for_each_entry(cn
, &clk_notifier_list
, node
)
2882 if (cn
->clk
== clk
) {
2883 ret
= srcu_notifier_chain_unregister(&cn
->notifier_head
, nb
);
2885 clk
->core
->notifier_count
--;
2887 /* XXX the notifier code should handle this better */
2888 if (!cn
->notifier_head
.head
) {
2889 srcu_cleanup_notifier_head(&cn
->notifier_head
);
2890 list_del(&cn
->node
);
2898 clk_prepare_unlock();
2902 EXPORT_SYMBOL_GPL(clk_notifier_unregister
);
2906 * struct of_clk_provider - Clock provider registration structure
2907 * @link: Entry in global list of clock providers
2908 * @node: Pointer to device tree node of clock provider
2909 * @get: Get clock callback. Returns NULL or a struct clk for the
2910 * given clock specifier
2911 * @data: context pointer to be passed into @get callback
2913 struct of_clk_provider
{
2914 struct list_head link
;
2916 struct device_node
*node
;
2917 struct clk
*(*get
)(struct of_phandle_args
*clkspec
, void *data
);
2921 static const struct of_device_id __clk_of_table_sentinel
2922 __used
__section(__clk_of_table_end
);
2924 static LIST_HEAD(of_clk_providers
);
2925 static DEFINE_MUTEX(of_clk_mutex
);
2927 struct clk
*of_clk_src_simple_get(struct of_phandle_args
*clkspec
,
2932 EXPORT_SYMBOL_GPL(of_clk_src_simple_get
);
2934 struct clk
*of_clk_src_onecell_get(struct of_phandle_args
*clkspec
, void *data
)
2936 struct clk_onecell_data
*clk_data
= data
;
2937 unsigned int idx
= clkspec
->args
[0];
2939 if (idx
>= clk_data
->clk_num
) {
2940 pr_err("%s: invalid clock index %d\n", __func__
, idx
);
2941 return ERR_PTR(-EINVAL
);
2944 return clk_data
->clks
[idx
];
2946 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get
);
2949 * of_clk_add_provider() - Register a clock provider for a node
2950 * @np: Device node pointer associated with clock provider
2951 * @clk_src_get: callback for decoding clock
2952 * @data: context pointer for @clk_src_get callback.
2954 int of_clk_add_provider(struct device_node
*np
,
2955 struct clk
*(*clk_src_get
)(struct of_phandle_args
*clkspec
,
2959 struct of_clk_provider
*cp
;
2962 cp
= kzalloc(sizeof(struct of_clk_provider
), GFP_KERNEL
);
2966 cp
->node
= of_node_get(np
);
2968 cp
->get
= clk_src_get
;
2970 mutex_lock(&of_clk_mutex
);
2971 list_add(&cp
->link
, &of_clk_providers
);
2972 mutex_unlock(&of_clk_mutex
);
2973 pr_debug("Added clock from %s\n", np
->full_name
);
2975 ret
= of_clk_set_defaults(np
, true);
2977 of_clk_del_provider(np
);
2981 EXPORT_SYMBOL_GPL(of_clk_add_provider
);
2984 * of_clk_del_provider() - Remove a previously registered clock provider
2985 * @np: Device node pointer associated with clock provider
2987 void of_clk_del_provider(struct device_node
*np
)
2989 struct of_clk_provider
*cp
;
2991 mutex_lock(&of_clk_mutex
);
2992 list_for_each_entry(cp
, &of_clk_providers
, link
) {
2993 if (cp
->node
== np
) {
2994 list_del(&cp
->link
);
2995 of_node_put(cp
->node
);
3000 mutex_unlock(&of_clk_mutex
);
3002 EXPORT_SYMBOL_GPL(of_clk_del_provider
);
3004 struct clk
*__of_clk_get_from_provider(struct of_phandle_args
*clkspec
,
3005 const char *dev_id
, const char *con_id
)
3007 struct of_clk_provider
*provider
;
3008 struct clk
*clk
= ERR_PTR(-EPROBE_DEFER
);
3011 return ERR_PTR(-EINVAL
);
3013 /* Check if we have such a provider in our array */
3014 mutex_lock(&of_clk_mutex
);
3015 list_for_each_entry(provider
, &of_clk_providers
, link
) {
3016 if (provider
->node
== clkspec
->np
)
3017 clk
= provider
->get(clkspec
, provider
->data
);
3019 clk
= __clk_create_clk(__clk_get_hw(clk
), dev_id
,
3022 if (!IS_ERR(clk
) && !__clk_get(clk
)) {
3023 __clk_free_clk(clk
);
3024 clk
= ERR_PTR(-ENOENT
);
3030 mutex_unlock(&of_clk_mutex
);
3036 * of_clk_get_from_provider() - Lookup a clock from a clock provider
3037 * @clkspec: pointer to a clock specifier data structure
3039 * This function looks up a struct clk from the registered list of clock
3040 * providers, an input is a clock specifier data structure as returned
3041 * from the of_parse_phandle_with_args() function call.
3043 struct clk
*of_clk_get_from_provider(struct of_phandle_args
*clkspec
)
3045 return __of_clk_get_from_provider(clkspec
, NULL
, __func__
);
3048 int of_clk_get_parent_count(struct device_node
*np
)
3050 return of_count_phandle_with_args(np
, "clocks", "#clock-cells");
3052 EXPORT_SYMBOL_GPL(of_clk_get_parent_count
);
3054 const char *of_clk_get_parent_name(struct device_node
*np
, int index
)
3056 struct of_phandle_args clkspec
;
3057 struct property
*prop
;
3058 const char *clk_name
;
3067 rc
= of_parse_phandle_with_args(np
, "clocks", "#clock-cells", index
,
3072 index
= clkspec
.args_count
? clkspec
.args
[0] : 0;
3075 /* if there is an indices property, use it to transfer the index
3076 * specified into an array offset for the clock-output-names property.
3078 of_property_for_each_u32(clkspec
.np
, "clock-indices", prop
, vp
, pv
) {
3086 if (of_property_read_string_index(clkspec
.np
, "clock-output-names",
3089 clk_name
= clkspec
.np
->name
;
3091 of_node_put(clkspec
.np
);
3094 EXPORT_SYMBOL_GPL(of_clk_get_parent_name
);
3097 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
3099 * @np: Device node pointer associated with clock provider
3100 * @parents: pointer to char array that hold the parents' names
3101 * @size: size of the @parents array
3103 * Return: number of parents for the clock node.
3105 int of_clk_parent_fill(struct device_node
*np
, const char **parents
,
3110 while (i
< size
&& (parents
[i
] = of_clk_get_parent_name(np
, i
)) != NULL
)
3115 EXPORT_SYMBOL_GPL(of_clk_parent_fill
);
3117 struct clock_provider
{
3118 of_clk_init_cb_t clk_init_cb
;
3119 struct device_node
*np
;
3120 struct list_head node
;
3124 * This function looks for a parent clock. If there is one, then it
3125 * checks that the provider for this parent clock was initialized, in
3126 * this case the parent clock will be ready.
3128 static int parent_ready(struct device_node
*np
)
3133 struct clk
*clk
= of_clk_get(np
, i
);
3135 /* this parent is ready we can check the next one */
3142 /* at least one parent is not ready, we exit now */
3143 if (PTR_ERR(clk
) == -EPROBE_DEFER
)
3147 * Here we make assumption that the device tree is
3148 * written correctly. So an error means that there is
3149 * no more parent. As we didn't exit yet, then the
3150 * previous parent are ready. If there is no clock
3151 * parent, no need to wait for them, then we can
3152 * consider their absence as being ready
3159 * of_clk_init() - Scan and init clock providers from the DT
3160 * @matches: array of compatible values and init functions for providers.
3162 * This function scans the device tree for matching clock providers
3163 * and calls their initialization functions. It also does it by trying
3164 * to follow the dependencies.
3166 void __init
of_clk_init(const struct of_device_id
*matches
)
3168 const struct of_device_id
*match
;
3169 struct device_node
*np
;
3170 struct clock_provider
*clk_provider
, *next
;
3173 LIST_HEAD(clk_provider_list
);
3176 matches
= &__clk_of_table
;
3178 /* First prepare the list of the clocks providers */
3179 for_each_matching_node_and_match(np
, matches
, &match
) {
3180 struct clock_provider
*parent
;
3182 parent
= kzalloc(sizeof(*parent
), GFP_KERNEL
);
3184 list_for_each_entry_safe(clk_provider
, next
,
3185 &clk_provider_list
, node
) {
3186 list_del(&clk_provider
->node
);
3187 kfree(clk_provider
);
3192 parent
->clk_init_cb
= match
->data
;
3194 list_add_tail(&parent
->node
, &clk_provider_list
);
3197 while (!list_empty(&clk_provider_list
)) {
3198 is_init_done
= false;
3199 list_for_each_entry_safe(clk_provider
, next
,
3200 &clk_provider_list
, node
) {
3201 if (force
|| parent_ready(clk_provider
->np
)) {
3203 clk_provider
->clk_init_cb(clk_provider
->np
);
3204 of_clk_set_defaults(clk_provider
->np
, true);
3206 list_del(&clk_provider
->node
);
3207 kfree(clk_provider
);
3208 is_init_done
= true;
3213 * We didn't manage to initialize any of the
3214 * remaining providers during the last loop, so now we
3215 * initialize all the remaining ones unconditionally
3216 * in case the clock parent was not mandatory