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(const 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
)
354 if (!core
->parents
[index
])
355 core
->parents
[index
] =
356 clk_core_lookup(core
->parent_names
[index
]);
358 return core
->parents
[index
];
362 clk_hw_get_parent_by_index(const struct clk_hw
*hw
, unsigned int index
)
364 struct clk_core
*parent
;
366 parent
= clk_core_get_parent_by_index(hw
->core
, index
);
368 return !parent
? NULL
: parent
->hw
;
370 EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index
);
372 unsigned int __clk_get_enable_count(struct clk
*clk
)
374 return !clk
? 0 : clk
->core
->enable_count
;
377 static unsigned long clk_core_get_rate_nolock(struct clk_core
*core
)
388 if (!core
->num_parents
)
398 unsigned long clk_hw_get_rate(const struct clk_hw
*hw
)
400 return clk_core_get_rate_nolock(hw
->core
);
402 EXPORT_SYMBOL_GPL(clk_hw_get_rate
);
404 static unsigned long __clk_get_accuracy(struct clk_core
*core
)
409 return core
->accuracy
;
412 unsigned long __clk_get_flags(struct clk
*clk
)
414 return !clk
? 0 : clk
->core
->flags
;
416 EXPORT_SYMBOL_GPL(__clk_get_flags
);
418 unsigned long clk_hw_get_flags(const struct clk_hw
*hw
)
420 return hw
->core
->flags
;
422 EXPORT_SYMBOL_GPL(clk_hw_get_flags
);
424 bool clk_hw_is_prepared(const struct clk_hw
*hw
)
426 return clk_core_is_prepared(hw
->core
);
429 bool clk_hw_is_enabled(const struct clk_hw
*hw
)
431 return clk_core_is_enabled(hw
->core
);
434 bool __clk_is_enabled(struct clk
*clk
)
439 return clk_core_is_enabled(clk
->core
);
441 EXPORT_SYMBOL_GPL(__clk_is_enabled
);
443 static bool mux_is_better_rate(unsigned long rate
, unsigned long now
,
444 unsigned long best
, unsigned long flags
)
446 if (flags
& CLK_MUX_ROUND_CLOSEST
)
447 return abs(now
- rate
) < abs(best
- rate
);
449 return now
<= rate
&& now
> best
;
453 clk_mux_determine_rate_flags(struct clk_hw
*hw
, struct clk_rate_request
*req
,
456 struct clk_core
*core
= hw
->core
, *parent
, *best_parent
= NULL
;
457 int i
, num_parents
, ret
;
458 unsigned long best
= 0;
459 struct clk_rate_request parent_req
= *req
;
461 /* if NO_REPARENT flag set, pass through to current parent */
462 if (core
->flags
& CLK_SET_RATE_NO_REPARENT
) {
463 parent
= core
->parent
;
464 if (core
->flags
& CLK_SET_RATE_PARENT
) {
465 ret
= __clk_determine_rate(parent
? parent
->hw
: NULL
,
470 best
= parent_req
.rate
;
472 best
= clk_core_get_rate_nolock(parent
);
474 best
= clk_core_get_rate_nolock(core
);
480 /* find the parent that can provide the fastest rate <= rate */
481 num_parents
= core
->num_parents
;
482 for (i
= 0; i
< num_parents
; i
++) {
483 parent
= clk_core_get_parent_by_index(core
, i
);
487 if (core
->flags
& CLK_SET_RATE_PARENT
) {
489 ret
= __clk_determine_rate(parent
->hw
, &parent_req
);
493 parent_req
.rate
= clk_core_get_rate_nolock(parent
);
496 if (mux_is_better_rate(req
->rate
, parent_req
.rate
,
498 best_parent
= parent
;
499 best
= parent_req
.rate
;
508 req
->best_parent_hw
= best_parent
->hw
;
509 req
->best_parent_rate
= best
;
515 struct clk
*__clk_lookup(const char *name
)
517 struct clk_core
*core
= clk_core_lookup(name
);
519 return !core
? NULL
: core
->hw
->clk
;
522 static void clk_core_get_boundaries(struct clk_core
*core
,
523 unsigned long *min_rate
,
524 unsigned long *max_rate
)
526 struct clk
*clk_user
;
528 *min_rate
= core
->min_rate
;
529 *max_rate
= core
->max_rate
;
531 hlist_for_each_entry(clk_user
, &core
->clks
, clks_node
)
532 *min_rate
= max(*min_rate
, clk_user
->min_rate
);
534 hlist_for_each_entry(clk_user
, &core
->clks
, clks_node
)
535 *max_rate
= min(*max_rate
, clk_user
->max_rate
);
538 void clk_hw_set_rate_range(struct clk_hw
*hw
, unsigned long min_rate
,
539 unsigned long max_rate
)
541 hw
->core
->min_rate
= min_rate
;
542 hw
->core
->max_rate
= max_rate
;
544 EXPORT_SYMBOL_GPL(clk_hw_set_rate_range
);
547 * Helper for finding best parent to provide a given frequency. This can be used
548 * directly as a determine_rate callback (e.g. for a mux), or from a more
549 * complex clock that may combine a mux with other operations.
551 int __clk_mux_determine_rate(struct clk_hw
*hw
,
552 struct clk_rate_request
*req
)
554 return clk_mux_determine_rate_flags(hw
, req
, 0);
556 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate
);
558 int __clk_mux_determine_rate_closest(struct clk_hw
*hw
,
559 struct clk_rate_request
*req
)
561 return clk_mux_determine_rate_flags(hw
, req
, CLK_MUX_ROUND_CLOSEST
);
563 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest
);
567 static void clk_core_unprepare(struct clk_core
*core
)
569 lockdep_assert_held(&prepare_lock
);
574 if (WARN_ON(core
->prepare_count
== 0))
577 if (WARN_ON(core
->prepare_count
== 1 && core
->flags
& CLK_IS_CRITICAL
))
580 if (--core
->prepare_count
> 0)
583 WARN_ON(core
->enable_count
> 0);
585 trace_clk_unprepare(core
);
587 if (core
->ops
->unprepare
)
588 core
->ops
->unprepare(core
->hw
);
590 trace_clk_unprepare_complete(core
);
591 clk_core_unprepare(core
->parent
);
595 * clk_unprepare - undo preparation of a clock source
596 * @clk: the clk being unprepared
598 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
599 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
600 * if the operation may sleep. One example is a clk which is accessed over
601 * I2c. In the complex case a clk gate operation may require a fast and a slow
602 * part. It is this reason that clk_unprepare and clk_disable are not mutually
603 * exclusive. In fact clk_disable must be called before clk_unprepare.
605 void clk_unprepare(struct clk
*clk
)
607 if (IS_ERR_OR_NULL(clk
))
611 clk_core_unprepare(clk
->core
);
612 clk_prepare_unlock();
614 EXPORT_SYMBOL_GPL(clk_unprepare
);
616 static int clk_core_prepare(struct clk_core
*core
)
620 lockdep_assert_held(&prepare_lock
);
625 if (core
->prepare_count
== 0) {
626 ret
= clk_core_prepare(core
->parent
);
630 trace_clk_prepare(core
);
632 if (core
->ops
->prepare
)
633 ret
= core
->ops
->prepare(core
->hw
);
635 trace_clk_prepare_complete(core
);
638 clk_core_unprepare(core
->parent
);
643 core
->prepare_count
++;
649 * clk_prepare - prepare a clock source
650 * @clk: the clk being prepared
652 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
653 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
654 * operation may sleep. One example is a clk which is accessed over I2c. In
655 * the complex case a clk ungate operation may require a fast and a slow part.
656 * It is this reason that clk_prepare and clk_enable are not mutually
657 * exclusive. In fact clk_prepare must be called before clk_enable.
658 * Returns 0 on success, -EERROR otherwise.
660 int clk_prepare(struct clk
*clk
)
668 ret
= clk_core_prepare(clk
->core
);
669 clk_prepare_unlock();
673 EXPORT_SYMBOL_GPL(clk_prepare
);
675 static void clk_core_disable(struct clk_core
*core
)
677 lockdep_assert_held(&enable_lock
);
682 if (WARN_ON(core
->enable_count
== 0))
685 if (WARN_ON(core
->enable_count
== 1 && core
->flags
& CLK_IS_CRITICAL
))
688 if (--core
->enable_count
> 0)
691 trace_clk_disable_rcuidle(core
);
693 if (core
->ops
->disable
)
694 core
->ops
->disable(core
->hw
);
696 trace_clk_disable_complete_rcuidle(core
);
698 clk_core_disable(core
->parent
);
702 * clk_disable - gate a clock
703 * @clk: the clk being gated
705 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
706 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
707 * clk if the operation is fast and will never sleep. One example is a
708 * SoC-internal clk which is controlled via simple register writes. In the
709 * complex case a clk gate operation may require a fast and a slow part. It is
710 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
711 * In fact clk_disable must be called before clk_unprepare.
713 void clk_disable(struct clk
*clk
)
717 if (IS_ERR_OR_NULL(clk
))
720 flags
= clk_enable_lock();
721 clk_core_disable(clk
->core
);
722 clk_enable_unlock(flags
);
724 EXPORT_SYMBOL_GPL(clk_disable
);
726 static int clk_core_enable(struct clk_core
*core
)
730 lockdep_assert_held(&enable_lock
);
735 if (WARN_ON(core
->prepare_count
== 0))
738 if (core
->enable_count
== 0) {
739 ret
= clk_core_enable(core
->parent
);
744 trace_clk_enable_rcuidle(core
);
746 if (core
->ops
->enable
)
747 ret
= core
->ops
->enable(core
->hw
);
749 trace_clk_enable_complete_rcuidle(core
);
752 clk_core_disable(core
->parent
);
757 core
->enable_count
++;
762 * clk_enable - ungate a clock
763 * @clk: the clk being ungated
765 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
766 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
767 * if the operation will never sleep. One example is a SoC-internal clk which
768 * is controlled via simple register writes. In the complex case a clk ungate
769 * operation may require a fast and a slow part. It is this reason that
770 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
771 * must be called before clk_enable. Returns 0 on success, -EERROR
774 int clk_enable(struct clk
*clk
)
782 flags
= clk_enable_lock();
783 ret
= clk_core_enable(clk
->core
);
784 clk_enable_unlock(flags
);
788 EXPORT_SYMBOL_GPL(clk_enable
);
790 static int clk_core_round_rate_nolock(struct clk_core
*core
,
791 struct clk_rate_request
*req
)
793 struct clk_core
*parent
;
796 lockdep_assert_held(&prepare_lock
);
801 parent
= core
->parent
;
803 req
->best_parent_hw
= parent
->hw
;
804 req
->best_parent_rate
= parent
->rate
;
806 req
->best_parent_hw
= NULL
;
807 req
->best_parent_rate
= 0;
810 if (core
->ops
->determine_rate
) {
811 return core
->ops
->determine_rate(core
->hw
, req
);
812 } else if (core
->ops
->round_rate
) {
813 rate
= core
->ops
->round_rate(core
->hw
, req
->rate
,
814 &req
->best_parent_rate
);
819 } else if (core
->flags
& CLK_SET_RATE_PARENT
) {
820 return clk_core_round_rate_nolock(parent
, req
);
822 req
->rate
= core
->rate
;
829 * __clk_determine_rate - get the closest rate actually supported by a clock
830 * @hw: determine the rate of this clock
831 * @req: target rate request
833 * Useful for clk_ops such as .set_rate and .determine_rate.
835 int __clk_determine_rate(struct clk_hw
*hw
, struct clk_rate_request
*req
)
842 return clk_core_round_rate_nolock(hw
->core
, req
);
844 EXPORT_SYMBOL_GPL(__clk_determine_rate
);
846 unsigned long clk_hw_round_rate(struct clk_hw
*hw
, unsigned long rate
)
849 struct clk_rate_request req
;
851 clk_core_get_boundaries(hw
->core
, &req
.min_rate
, &req
.max_rate
);
854 ret
= clk_core_round_rate_nolock(hw
->core
, &req
);
860 EXPORT_SYMBOL_GPL(clk_hw_round_rate
);
863 * clk_round_rate - round the given rate for a clk
864 * @clk: the clk for which we are rounding a rate
865 * @rate: the rate which is to be rounded
867 * Takes in a rate as input and rounds it to a rate that the clk can actually
868 * use which is then returned. If clk doesn't support round_rate operation
869 * then the parent rate is returned.
871 long clk_round_rate(struct clk
*clk
, unsigned long rate
)
873 struct clk_rate_request req
;
881 clk_core_get_boundaries(clk
->core
, &req
.min_rate
, &req
.max_rate
);
884 ret
= clk_core_round_rate_nolock(clk
->core
, &req
);
885 clk_prepare_unlock();
892 EXPORT_SYMBOL_GPL(clk_round_rate
);
895 * __clk_notify - call clk notifier chain
896 * @core: clk that is changing rate
897 * @msg: clk notifier type (see include/linux/clk.h)
898 * @old_rate: old clk rate
899 * @new_rate: new clk rate
901 * Triggers a notifier call chain on the clk rate-change notification
902 * for 'clk'. Passes a pointer to the struct clk and the previous
903 * and current rates to the notifier callback. Intended to be called by
904 * internal clock code only. Returns NOTIFY_DONE from the last driver
905 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
906 * a driver returns that.
908 static int __clk_notify(struct clk_core
*core
, unsigned long msg
,
909 unsigned long old_rate
, unsigned long new_rate
)
911 struct clk_notifier
*cn
;
912 struct clk_notifier_data cnd
;
913 int ret
= NOTIFY_DONE
;
915 cnd
.old_rate
= old_rate
;
916 cnd
.new_rate
= new_rate
;
918 list_for_each_entry(cn
, &clk_notifier_list
, node
) {
919 if (cn
->clk
->core
== core
) {
921 ret
= srcu_notifier_call_chain(&cn
->notifier_head
, msg
,
930 * __clk_recalc_accuracies
931 * @core: first clk in the subtree
933 * Walks the subtree of clks starting with clk and recalculates accuracies as
934 * it goes. Note that if a clk does not implement the .recalc_accuracy
935 * callback then it is assumed that the clock will take on the accuracy of its
938 static void __clk_recalc_accuracies(struct clk_core
*core
)
940 unsigned long parent_accuracy
= 0;
941 struct clk_core
*child
;
943 lockdep_assert_held(&prepare_lock
);
946 parent_accuracy
= core
->parent
->accuracy
;
948 if (core
->ops
->recalc_accuracy
)
949 core
->accuracy
= core
->ops
->recalc_accuracy(core
->hw
,
952 core
->accuracy
= parent_accuracy
;
954 hlist_for_each_entry(child
, &core
->children
, child_node
)
955 __clk_recalc_accuracies(child
);
958 static long clk_core_get_accuracy(struct clk_core
*core
)
960 unsigned long accuracy
;
963 if (core
&& (core
->flags
& CLK_GET_ACCURACY_NOCACHE
))
964 __clk_recalc_accuracies(core
);
966 accuracy
= __clk_get_accuracy(core
);
967 clk_prepare_unlock();
973 * clk_get_accuracy - return the accuracy of clk
974 * @clk: the clk whose accuracy is being returned
976 * Simply returns the cached accuracy of the clk, unless
977 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
979 * If clk is NULL then returns 0.
981 long clk_get_accuracy(struct clk
*clk
)
986 return clk_core_get_accuracy(clk
->core
);
988 EXPORT_SYMBOL_GPL(clk_get_accuracy
);
990 static unsigned long clk_recalc(struct clk_core
*core
,
991 unsigned long parent_rate
)
993 if (core
->ops
->recalc_rate
)
994 return core
->ops
->recalc_rate(core
->hw
, parent_rate
);
1000 * @core: first clk in the subtree
1001 * @msg: notification type (see include/linux/clk.h)
1003 * Walks the subtree of clks starting with clk and recalculates rates as it
1004 * goes. Note that if a clk does not implement the .recalc_rate callback then
1005 * it is assumed that the clock will take on the rate of its parent.
1007 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1010 static void __clk_recalc_rates(struct clk_core
*core
, unsigned long msg
)
1012 unsigned long old_rate
;
1013 unsigned long parent_rate
= 0;
1014 struct clk_core
*child
;
1016 lockdep_assert_held(&prepare_lock
);
1018 old_rate
= core
->rate
;
1021 parent_rate
= core
->parent
->rate
;
1023 core
->rate
= clk_recalc(core
, parent_rate
);
1026 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1027 * & ABORT_RATE_CHANGE notifiers
1029 if (core
->notifier_count
&& msg
)
1030 __clk_notify(core
, msg
, old_rate
, core
->rate
);
1032 hlist_for_each_entry(child
, &core
->children
, child_node
)
1033 __clk_recalc_rates(child
, msg
);
1036 static unsigned long clk_core_get_rate(struct clk_core
*core
)
1042 if (core
&& (core
->flags
& CLK_GET_RATE_NOCACHE
))
1043 __clk_recalc_rates(core
, 0);
1045 rate
= clk_core_get_rate_nolock(core
);
1046 clk_prepare_unlock();
1052 * clk_get_rate - return the rate of clk
1053 * @clk: the clk whose rate is being returned
1055 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1056 * is set, which means a recalc_rate will be issued.
1057 * If clk is NULL then returns 0.
1059 unsigned long clk_get_rate(struct clk
*clk
)
1064 return clk_core_get_rate(clk
->core
);
1066 EXPORT_SYMBOL_GPL(clk_get_rate
);
1068 static int clk_fetch_parent_index(struct clk_core
*core
,
1069 struct clk_core
*parent
)
1076 for (i
= 0; i
< core
->num_parents
; i
++)
1077 if (clk_core_get_parent_by_index(core
, i
) == parent
)
1084 * Update the orphan status of @core and all its children.
1086 static void clk_core_update_orphan_status(struct clk_core
*core
, bool is_orphan
)
1088 struct clk_core
*child
;
1090 core
->orphan
= is_orphan
;
1092 hlist_for_each_entry(child
, &core
->children
, child_node
)
1093 clk_core_update_orphan_status(child
, is_orphan
);
1096 static void clk_reparent(struct clk_core
*core
, struct clk_core
*new_parent
)
1098 bool was_orphan
= core
->orphan
;
1100 hlist_del(&core
->child_node
);
1103 bool becomes_orphan
= new_parent
->orphan
;
1105 /* avoid duplicate POST_RATE_CHANGE notifications */
1106 if (new_parent
->new_child
== core
)
1107 new_parent
->new_child
= NULL
;
1109 hlist_add_head(&core
->child_node
, &new_parent
->children
);
1111 if (was_orphan
!= becomes_orphan
)
1112 clk_core_update_orphan_status(core
, becomes_orphan
);
1114 hlist_add_head(&core
->child_node
, &clk_orphan_list
);
1116 clk_core_update_orphan_status(core
, true);
1119 core
->parent
= new_parent
;
1122 static struct clk_core
*__clk_set_parent_before(struct clk_core
*core
,
1123 struct clk_core
*parent
)
1125 unsigned long flags
;
1126 struct clk_core
*old_parent
= core
->parent
;
1129 * Migrate prepare state between parents and prevent race with
1132 * If the clock is not prepared, then a race with
1133 * clk_enable/disable() is impossible since we already have the
1134 * prepare lock (future calls to clk_enable() need to be preceded by
1137 * If the clock is prepared, migrate the prepared state to the new
1138 * parent and also protect against a race with clk_enable() by
1139 * forcing the clock and the new parent on. This ensures that all
1140 * future calls to clk_enable() are practically NOPs with respect to
1141 * hardware and software states.
1143 * See also: Comment for clk_set_parent() below.
1145 if (core
->prepare_count
) {
1146 clk_core_prepare(parent
);
1147 flags
= clk_enable_lock();
1148 clk_core_enable(parent
);
1149 clk_core_enable(core
);
1150 clk_enable_unlock(flags
);
1153 /* update the clk tree topology */
1154 flags
= clk_enable_lock();
1155 clk_reparent(core
, parent
);
1156 clk_enable_unlock(flags
);
1161 static void __clk_set_parent_after(struct clk_core
*core
,
1162 struct clk_core
*parent
,
1163 struct clk_core
*old_parent
)
1165 unsigned long flags
;
1168 * Finish the migration of prepare state and undo the changes done
1169 * for preventing a race with clk_enable().
1171 if (core
->prepare_count
) {
1172 flags
= clk_enable_lock();
1173 clk_core_disable(core
);
1174 clk_core_disable(old_parent
);
1175 clk_enable_unlock(flags
);
1176 clk_core_unprepare(old_parent
);
1180 static int __clk_set_parent(struct clk_core
*core
, struct clk_core
*parent
,
1183 unsigned long flags
;
1185 struct clk_core
*old_parent
;
1187 old_parent
= __clk_set_parent_before(core
, parent
);
1189 trace_clk_set_parent(core
, parent
);
1191 /* change clock input source */
1192 if (parent
&& core
->ops
->set_parent
)
1193 ret
= core
->ops
->set_parent(core
->hw
, p_index
);
1195 trace_clk_set_parent_complete(core
, parent
);
1198 flags
= clk_enable_lock();
1199 clk_reparent(core
, old_parent
);
1200 clk_enable_unlock(flags
);
1201 __clk_set_parent_after(core
, old_parent
, parent
);
1206 __clk_set_parent_after(core
, parent
, old_parent
);
1212 * __clk_speculate_rates
1213 * @core: first clk in the subtree
1214 * @parent_rate: the "future" rate of clk's parent
1216 * Walks the subtree of clks starting with clk, speculating rates as it
1217 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1219 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1220 * pre-rate change notifications and returns early if no clks in the
1221 * subtree have subscribed to the notifications. Note that if a clk does not
1222 * implement the .recalc_rate callback then it is assumed that the clock will
1223 * take on the rate of its parent.
1225 static int __clk_speculate_rates(struct clk_core
*core
,
1226 unsigned long parent_rate
)
1228 struct clk_core
*child
;
1229 unsigned long new_rate
;
1230 int ret
= NOTIFY_DONE
;
1232 lockdep_assert_held(&prepare_lock
);
1234 new_rate
= clk_recalc(core
, parent_rate
);
1236 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1237 if (core
->notifier_count
)
1238 ret
= __clk_notify(core
, PRE_RATE_CHANGE
, core
->rate
, new_rate
);
1240 if (ret
& NOTIFY_STOP_MASK
) {
1241 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1242 __func__
, core
->name
, ret
);
1246 hlist_for_each_entry(child
, &core
->children
, child_node
) {
1247 ret
= __clk_speculate_rates(child
, new_rate
);
1248 if (ret
& NOTIFY_STOP_MASK
)
1256 static void clk_calc_subtree(struct clk_core
*core
, unsigned long new_rate
,
1257 struct clk_core
*new_parent
, u8 p_index
)
1259 struct clk_core
*child
;
1261 core
->new_rate
= new_rate
;
1262 core
->new_parent
= new_parent
;
1263 core
->new_parent_index
= p_index
;
1264 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1265 core
->new_child
= NULL
;
1266 if (new_parent
&& new_parent
!= core
->parent
)
1267 new_parent
->new_child
= core
;
1269 hlist_for_each_entry(child
, &core
->children
, child_node
) {
1270 child
->new_rate
= clk_recalc(child
, new_rate
);
1271 clk_calc_subtree(child
, child
->new_rate
, NULL
, 0);
1276 * calculate the new rates returning the topmost clock that has to be
1279 static struct clk_core
*clk_calc_new_rates(struct clk_core
*core
,
1282 struct clk_core
*top
= core
;
1283 struct clk_core
*old_parent
, *parent
;
1284 unsigned long best_parent_rate
= 0;
1285 unsigned long new_rate
;
1286 unsigned long min_rate
;
1287 unsigned long max_rate
;
1292 if (IS_ERR_OR_NULL(core
))
1295 /* save parent rate, if it exists */
1296 parent
= old_parent
= core
->parent
;
1298 best_parent_rate
= parent
->rate
;
1300 clk_core_get_boundaries(core
, &min_rate
, &max_rate
);
1302 /* find the closest rate and parent clk/rate */
1303 if (core
->ops
->determine_rate
) {
1304 struct clk_rate_request req
;
1307 req
.min_rate
= min_rate
;
1308 req
.max_rate
= max_rate
;
1310 req
.best_parent_hw
= parent
->hw
;
1311 req
.best_parent_rate
= parent
->rate
;
1313 req
.best_parent_hw
= NULL
;
1314 req
.best_parent_rate
= 0;
1317 ret
= core
->ops
->determine_rate(core
->hw
, &req
);
1321 best_parent_rate
= req
.best_parent_rate
;
1322 new_rate
= req
.rate
;
1323 parent
= req
.best_parent_hw
? req
.best_parent_hw
->core
: NULL
;
1324 } else if (core
->ops
->round_rate
) {
1325 ret
= core
->ops
->round_rate(core
->hw
, rate
,
1331 if (new_rate
< min_rate
|| new_rate
> max_rate
)
1333 } else if (!parent
|| !(core
->flags
& CLK_SET_RATE_PARENT
)) {
1334 /* pass-through clock without adjustable parent */
1335 core
->new_rate
= core
->rate
;
1338 /* pass-through clock with adjustable parent */
1339 top
= clk_calc_new_rates(parent
, rate
);
1340 new_rate
= parent
->new_rate
;
1344 /* some clocks must be gated to change parent */
1345 if (parent
!= old_parent
&&
1346 (core
->flags
& CLK_SET_PARENT_GATE
) && core
->prepare_count
) {
1347 pr_debug("%s: %s not gated but wants to reparent\n",
1348 __func__
, core
->name
);
1352 /* try finding the new parent index */
1353 if (parent
&& core
->num_parents
> 1) {
1354 p_index
= clk_fetch_parent_index(core
, parent
);
1356 pr_debug("%s: clk %s can not be parent of clk %s\n",
1357 __func__
, parent
->name
, core
->name
);
1362 if ((core
->flags
& CLK_SET_RATE_PARENT
) && parent
&&
1363 best_parent_rate
!= parent
->rate
)
1364 top
= clk_calc_new_rates(parent
, best_parent_rate
);
1367 clk_calc_subtree(core
, new_rate
, parent
, p_index
);
1373 * Notify about rate changes in a subtree. Always walk down the whole tree
1374 * so that in case of an error we can walk down the whole tree again and
1377 static struct clk_core
*clk_propagate_rate_change(struct clk_core
*core
,
1378 unsigned long event
)
1380 struct clk_core
*child
, *tmp_clk
, *fail_clk
= NULL
;
1381 int ret
= NOTIFY_DONE
;
1383 if (core
->rate
== core
->new_rate
)
1386 if (core
->notifier_count
) {
1387 ret
= __clk_notify(core
, event
, core
->rate
, core
->new_rate
);
1388 if (ret
& NOTIFY_STOP_MASK
)
1392 hlist_for_each_entry(child
, &core
->children
, child_node
) {
1393 /* Skip children who will be reparented to another clock */
1394 if (child
->new_parent
&& child
->new_parent
!= core
)
1396 tmp_clk
= clk_propagate_rate_change(child
, event
);
1401 /* handle the new child who might not be in core->children yet */
1402 if (core
->new_child
) {
1403 tmp_clk
= clk_propagate_rate_change(core
->new_child
, event
);
1412 * walk down a subtree and set the new rates notifying the rate
1415 static void clk_change_rate(struct clk_core
*core
)
1417 struct clk_core
*child
;
1418 struct hlist_node
*tmp
;
1419 unsigned long old_rate
;
1420 unsigned long best_parent_rate
= 0;
1421 bool skip_set_rate
= false;
1422 struct clk_core
*old_parent
;
1424 old_rate
= core
->rate
;
1426 if (core
->new_parent
)
1427 best_parent_rate
= core
->new_parent
->rate
;
1428 else if (core
->parent
)
1429 best_parent_rate
= core
->parent
->rate
;
1431 if (core
->flags
& CLK_SET_RATE_UNGATE
) {
1432 unsigned long flags
;
1434 clk_core_prepare(core
);
1435 flags
= clk_enable_lock();
1436 clk_core_enable(core
);
1437 clk_enable_unlock(flags
);
1440 if (core
->new_parent
&& core
->new_parent
!= core
->parent
) {
1441 old_parent
= __clk_set_parent_before(core
, core
->new_parent
);
1442 trace_clk_set_parent(core
, core
->new_parent
);
1444 if (core
->ops
->set_rate_and_parent
) {
1445 skip_set_rate
= true;
1446 core
->ops
->set_rate_and_parent(core
->hw
, core
->new_rate
,
1448 core
->new_parent_index
);
1449 } else if (core
->ops
->set_parent
) {
1450 core
->ops
->set_parent(core
->hw
, core
->new_parent_index
);
1453 trace_clk_set_parent_complete(core
, core
->new_parent
);
1454 __clk_set_parent_after(core
, core
->new_parent
, old_parent
);
1457 trace_clk_set_rate(core
, core
->new_rate
);
1459 if (!skip_set_rate
&& core
->ops
->set_rate
)
1460 core
->ops
->set_rate(core
->hw
, core
->new_rate
, best_parent_rate
);
1462 trace_clk_set_rate_complete(core
, core
->new_rate
);
1464 core
->rate
= clk_recalc(core
, best_parent_rate
);
1466 if (core
->flags
& CLK_SET_RATE_UNGATE
) {
1467 unsigned long flags
;
1469 flags
= clk_enable_lock();
1470 clk_core_disable(core
);
1471 clk_enable_unlock(flags
);
1472 clk_core_unprepare(core
);
1475 if (core
->notifier_count
&& old_rate
!= core
->rate
)
1476 __clk_notify(core
, POST_RATE_CHANGE
, old_rate
, core
->rate
);
1478 if (core
->flags
& CLK_RECALC_NEW_RATES
)
1479 (void)clk_calc_new_rates(core
, core
->new_rate
);
1482 * Use safe iteration, as change_rate can actually swap parents
1483 * for certain clock types.
1485 hlist_for_each_entry_safe(child
, tmp
, &core
->children
, child_node
) {
1486 /* Skip children who will be reparented to another clock */
1487 if (child
->new_parent
&& child
->new_parent
!= core
)
1489 clk_change_rate(child
);
1492 /* handle the new child who might not be in core->children yet */
1493 if (core
->new_child
)
1494 clk_change_rate(core
->new_child
);
1497 static int clk_core_set_rate_nolock(struct clk_core
*core
,
1498 unsigned long req_rate
)
1500 struct clk_core
*top
, *fail_clk
;
1501 unsigned long rate
= req_rate
;
1506 /* bail early if nothing to do */
1507 if (rate
== clk_core_get_rate_nolock(core
))
1510 if ((core
->flags
& CLK_SET_RATE_GATE
) && core
->prepare_count
)
1513 /* calculate new rates and get the topmost changed clock */
1514 top
= clk_calc_new_rates(core
, rate
);
1518 /* notify that we are about to change rates */
1519 fail_clk
= clk_propagate_rate_change(top
, PRE_RATE_CHANGE
);
1521 pr_debug("%s: failed to set %s rate\n", __func__
,
1523 clk_propagate_rate_change(top
, ABORT_RATE_CHANGE
);
1527 /* change the rates */
1528 clk_change_rate(top
);
1530 core
->req_rate
= req_rate
;
1536 * clk_set_rate - specify a new rate for clk
1537 * @clk: the clk whose rate is being changed
1538 * @rate: the new rate for clk
1540 * In the simplest case clk_set_rate will only adjust the rate of clk.
1542 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1543 * propagate up to clk's parent; whether or not this happens depends on the
1544 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1545 * after calling .round_rate then upstream parent propagation is ignored. If
1546 * *parent_rate comes back with a new rate for clk's parent then we propagate
1547 * up to clk's parent and set its rate. Upward propagation will continue
1548 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1549 * .round_rate stops requesting changes to clk's parent_rate.
1551 * Rate changes are accomplished via tree traversal that also recalculates the
1552 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
1554 * Returns 0 on success, -EERROR otherwise.
1556 int clk_set_rate(struct clk
*clk
, unsigned long rate
)
1563 /* prevent racing with updates to the clock topology */
1566 ret
= clk_core_set_rate_nolock(clk
->core
, rate
);
1568 clk_prepare_unlock();
1572 EXPORT_SYMBOL_GPL(clk_set_rate
);
1575 * clk_set_rate_range - set a rate range for a clock source
1576 * @clk: clock source
1577 * @min: desired minimum clock rate in Hz, inclusive
1578 * @max: desired maximum clock rate in Hz, inclusive
1580 * Returns success (0) or negative errno.
1582 int clk_set_rate_range(struct clk
*clk
, unsigned long min
, unsigned long max
)
1590 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
1591 __func__
, clk
->core
->name
, clk
->dev_id
, clk
->con_id
,
1598 if (min
!= clk
->min_rate
|| max
!= clk
->max_rate
) {
1599 clk
->min_rate
= min
;
1600 clk
->max_rate
= max
;
1601 ret
= clk_core_set_rate_nolock(clk
->core
, clk
->core
->req_rate
);
1604 clk_prepare_unlock();
1608 EXPORT_SYMBOL_GPL(clk_set_rate_range
);
1611 * clk_set_min_rate - set a minimum clock rate for a clock source
1612 * @clk: clock source
1613 * @rate: desired minimum clock rate in Hz, inclusive
1615 * Returns success (0) or negative errno.
1617 int clk_set_min_rate(struct clk
*clk
, unsigned long rate
)
1622 return clk_set_rate_range(clk
, rate
, clk
->max_rate
);
1624 EXPORT_SYMBOL_GPL(clk_set_min_rate
);
1627 * clk_set_max_rate - set a maximum clock rate for a clock source
1628 * @clk: clock source
1629 * @rate: desired maximum clock rate in Hz, inclusive
1631 * Returns success (0) or negative errno.
1633 int clk_set_max_rate(struct clk
*clk
, unsigned long rate
)
1638 return clk_set_rate_range(clk
, clk
->min_rate
, rate
);
1640 EXPORT_SYMBOL_GPL(clk_set_max_rate
);
1643 * clk_get_parent - return the parent of a clk
1644 * @clk: the clk whose parent gets returned
1646 * Simply returns clk->parent. Returns NULL if clk is NULL.
1648 struct clk
*clk_get_parent(struct clk
*clk
)
1656 /* TODO: Create a per-user clk and change callers to call clk_put */
1657 parent
= !clk
->core
->parent
? NULL
: clk
->core
->parent
->hw
->clk
;
1658 clk_prepare_unlock();
1662 EXPORT_SYMBOL_GPL(clk_get_parent
);
1664 static struct clk_core
*__clk_init_parent(struct clk_core
*core
)
1668 if (core
->num_parents
> 1 && core
->ops
->get_parent
)
1669 index
= core
->ops
->get_parent(core
->hw
);
1671 return clk_core_get_parent_by_index(core
, index
);
1674 static void clk_core_reparent(struct clk_core
*core
,
1675 struct clk_core
*new_parent
)
1677 clk_reparent(core
, new_parent
);
1678 __clk_recalc_accuracies(core
);
1679 __clk_recalc_rates(core
, POST_RATE_CHANGE
);
1682 void clk_hw_reparent(struct clk_hw
*hw
, struct clk_hw
*new_parent
)
1687 clk_core_reparent(hw
->core
, !new_parent
? NULL
: new_parent
->core
);
1691 * clk_has_parent - check if a clock is a possible parent for another
1692 * @clk: clock source
1693 * @parent: parent clock source
1695 * This function can be used in drivers that need to check that a clock can be
1696 * the parent of another without actually changing the parent.
1698 * Returns true if @parent is a possible parent for @clk, false otherwise.
1700 bool clk_has_parent(struct clk
*clk
, struct clk
*parent
)
1702 struct clk_core
*core
, *parent_core
;
1705 /* NULL clocks should be nops, so return success if either is NULL. */
1706 if (!clk
|| !parent
)
1710 parent_core
= parent
->core
;
1712 /* Optimize for the case where the parent is already the parent. */
1713 if (core
->parent
== parent_core
)
1716 for (i
= 0; i
< core
->num_parents
; i
++)
1717 if (strcmp(core
->parent_names
[i
], parent_core
->name
) == 0)
1722 EXPORT_SYMBOL_GPL(clk_has_parent
);
1724 static int clk_core_set_parent(struct clk_core
*core
, struct clk_core
*parent
)
1728 unsigned long p_rate
= 0;
1733 /* prevent racing with updates to the clock topology */
1736 if (core
->parent
== parent
)
1739 /* verify ops for for multi-parent clks */
1740 if ((core
->num_parents
> 1) && (!core
->ops
->set_parent
)) {
1745 /* check that we are allowed to re-parent if the clock is in use */
1746 if ((core
->flags
& CLK_SET_PARENT_GATE
) && core
->prepare_count
) {
1751 /* try finding the new parent index */
1753 p_index
= clk_fetch_parent_index(core
, parent
);
1755 pr_debug("%s: clk %s can not be parent of clk %s\n",
1756 __func__
, parent
->name
, core
->name
);
1760 p_rate
= parent
->rate
;
1763 /* propagate PRE_RATE_CHANGE notifications */
1764 ret
= __clk_speculate_rates(core
, p_rate
);
1766 /* abort if a driver objects */
1767 if (ret
& NOTIFY_STOP_MASK
)
1770 /* do the re-parent */
1771 ret
= __clk_set_parent(core
, parent
, p_index
);
1773 /* propagate rate an accuracy recalculation accordingly */
1775 __clk_recalc_rates(core
, ABORT_RATE_CHANGE
);
1777 __clk_recalc_rates(core
, POST_RATE_CHANGE
);
1778 __clk_recalc_accuracies(core
);
1782 clk_prepare_unlock();
1788 * clk_set_parent - switch the parent of a mux clk
1789 * @clk: the mux clk whose input we are switching
1790 * @parent: the new input to clk
1792 * Re-parent clk to use parent as its new input source. If clk is in
1793 * prepared state, the clk will get enabled for the duration of this call. If
1794 * that's not acceptable for a specific clk (Eg: the consumer can't handle
1795 * that, the reparenting is glitchy in hardware, etc), use the
1796 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
1798 * After successfully changing clk's parent clk_set_parent will update the
1799 * clk topology, sysfs topology and propagate rate recalculation via
1800 * __clk_recalc_rates.
1802 * Returns 0 on success, -EERROR otherwise.
1804 int clk_set_parent(struct clk
*clk
, struct clk
*parent
)
1809 return clk_core_set_parent(clk
->core
, parent
? parent
->core
: NULL
);
1811 EXPORT_SYMBOL_GPL(clk_set_parent
);
1814 * clk_set_phase - adjust the phase shift of a clock signal
1815 * @clk: clock signal source
1816 * @degrees: number of degrees the signal is shifted
1818 * Shifts the phase of a clock signal by the specified
1819 * degrees. Returns 0 on success, -EERROR otherwise.
1821 * This function makes no distinction about the input or reference
1822 * signal that we adjust the clock signal phase against. For example
1823 * phase locked-loop clock signal generators we may shift phase with
1824 * respect to feedback clock signal input, but for other cases the
1825 * clock phase may be shifted with respect to some other, unspecified
1828 * Additionally the concept of phase shift does not propagate through
1829 * the clock tree hierarchy, which sets it apart from clock rates and
1830 * clock accuracy. A parent clock phase attribute does not have an
1831 * impact on the phase attribute of a child clock.
1833 int clk_set_phase(struct clk
*clk
, int degrees
)
1840 /* sanity check degrees */
1847 /* bail early if nothing to do */
1848 if (degrees
== clk
->core
->phase
)
1851 trace_clk_set_phase(clk
->core
, degrees
);
1853 if (clk
->core
->ops
->set_phase
)
1854 ret
= clk
->core
->ops
->set_phase(clk
->core
->hw
, degrees
);
1856 trace_clk_set_phase_complete(clk
->core
, degrees
);
1859 clk
->core
->phase
= degrees
;
1862 clk_prepare_unlock();
1866 EXPORT_SYMBOL_GPL(clk_set_phase
);
1868 static int clk_core_get_phase(struct clk_core
*core
)
1874 clk_prepare_unlock();
1880 * clk_get_phase - return the phase shift of a clock signal
1881 * @clk: clock signal source
1883 * Returns the phase shift of a clock node in degrees, otherwise returns
1886 int clk_get_phase(struct clk
*clk
)
1891 return clk_core_get_phase(clk
->core
);
1893 EXPORT_SYMBOL_GPL(clk_get_phase
);
1896 * clk_is_match - check if two clk's point to the same hardware clock
1897 * @p: clk compared against q
1898 * @q: clk compared against p
1900 * Returns true if the two struct clk pointers both point to the same hardware
1901 * clock node. Put differently, returns true if struct clk *p and struct clk *q
1902 * share the same struct clk_core object.
1904 * Returns false otherwise. Note that two NULL clks are treated as matching.
1906 bool clk_is_match(const struct clk
*p
, const struct clk
*q
)
1908 /* trivial case: identical struct clk's or both NULL */
1912 /* true if clk->core pointers match. Avoid dereferencing garbage */
1913 if (!IS_ERR_OR_NULL(p
) && !IS_ERR_OR_NULL(q
))
1914 if (p
->core
== q
->core
)
1919 EXPORT_SYMBOL_GPL(clk_is_match
);
1921 /*** debugfs support ***/
1923 #ifdef CONFIG_DEBUG_FS
1924 #include <linux/debugfs.h>
1926 static struct dentry
*rootdir
;
1927 static int inited
= 0;
1928 static DEFINE_MUTEX(clk_debug_lock
);
1929 static HLIST_HEAD(clk_debug_list
);
1931 static struct hlist_head
*all_lists
[] = {
1937 static struct hlist_head
*orphan_list
[] = {
1942 static void clk_summary_show_one(struct seq_file
*s
, struct clk_core
*c
,
1948 seq_printf(s
, "%*s%-*s %11d %12d %11lu %10lu %-3d\n",
1950 30 - level
* 3, c
->name
,
1951 c
->enable_count
, c
->prepare_count
, clk_core_get_rate(c
),
1952 clk_core_get_accuracy(c
), clk_core_get_phase(c
));
1955 static void clk_summary_show_subtree(struct seq_file
*s
, struct clk_core
*c
,
1958 struct clk_core
*child
;
1963 clk_summary_show_one(s
, c
, level
);
1965 hlist_for_each_entry(child
, &c
->children
, child_node
)
1966 clk_summary_show_subtree(s
, child
, level
+ 1);
1969 static int clk_summary_show(struct seq_file
*s
, void *data
)
1972 struct hlist_head
**lists
= (struct hlist_head
**)s
->private;
1974 seq_puts(s
, " clock enable_cnt prepare_cnt rate accuracy phase\n");
1975 seq_puts(s
, "----------------------------------------------------------------------------------------\n");
1979 for (; *lists
; lists
++)
1980 hlist_for_each_entry(c
, *lists
, child_node
)
1981 clk_summary_show_subtree(s
, c
, 0);
1983 clk_prepare_unlock();
1989 static int clk_summary_open(struct inode
*inode
, struct file
*file
)
1991 return single_open(file
, clk_summary_show
, inode
->i_private
);
1994 static const struct file_operations clk_summary_fops
= {
1995 .open
= clk_summary_open
,
1997 .llseek
= seq_lseek
,
1998 .release
= single_release
,
2001 static void clk_dump_one(struct seq_file
*s
, struct clk_core
*c
, int level
)
2006 /* This should be JSON format, i.e. elements separated with a comma */
2007 seq_printf(s
, "\"%s\": { ", c
->name
);
2008 seq_printf(s
, "\"enable_count\": %d,", c
->enable_count
);
2009 seq_printf(s
, "\"prepare_count\": %d,", c
->prepare_count
);
2010 seq_printf(s
, "\"rate\": %lu,", clk_core_get_rate(c
));
2011 seq_printf(s
, "\"accuracy\": %lu,", clk_core_get_accuracy(c
));
2012 seq_printf(s
, "\"phase\": %d", clk_core_get_phase(c
));
2015 static void clk_dump_subtree(struct seq_file
*s
, struct clk_core
*c
, int level
)
2017 struct clk_core
*child
;
2022 clk_dump_one(s
, c
, level
);
2024 hlist_for_each_entry(child
, &c
->children
, child_node
) {
2026 clk_dump_subtree(s
, child
, level
+ 1);
2032 static int clk_dump(struct seq_file
*s
, void *data
)
2035 bool first_node
= true;
2036 struct hlist_head
**lists
= (struct hlist_head
**)s
->private;
2042 for (; *lists
; lists
++) {
2043 hlist_for_each_entry(c
, *lists
, child_node
) {
2047 clk_dump_subtree(s
, c
, 0);
2051 clk_prepare_unlock();
2058 static int clk_dump_open(struct inode
*inode
, struct file
*file
)
2060 return single_open(file
, clk_dump
, inode
->i_private
);
2063 static const struct file_operations clk_dump_fops
= {
2064 .open
= clk_dump_open
,
2066 .llseek
= seq_lseek
,
2067 .release
= single_release
,
2070 static int clk_debug_create_one(struct clk_core
*core
, struct dentry
*pdentry
)
2075 if (!core
|| !pdentry
) {
2080 d
= debugfs_create_dir(core
->name
, pdentry
);
2086 d
= debugfs_create_u32("clk_rate", S_IRUGO
, core
->dentry
,
2087 (u32
*)&core
->rate
);
2091 d
= debugfs_create_u32("clk_accuracy", S_IRUGO
, core
->dentry
,
2092 (u32
*)&core
->accuracy
);
2096 d
= debugfs_create_u32("clk_phase", S_IRUGO
, core
->dentry
,
2097 (u32
*)&core
->phase
);
2101 d
= debugfs_create_x32("clk_flags", S_IRUGO
, core
->dentry
,
2102 (u32
*)&core
->flags
);
2106 d
= debugfs_create_u32("clk_prepare_count", S_IRUGO
, core
->dentry
,
2107 (u32
*)&core
->prepare_count
);
2111 d
= debugfs_create_u32("clk_enable_count", S_IRUGO
, core
->dentry
,
2112 (u32
*)&core
->enable_count
);
2116 d
= debugfs_create_u32("clk_notifier_count", S_IRUGO
, core
->dentry
,
2117 (u32
*)&core
->notifier_count
);
2121 if (core
->ops
->debug_init
) {
2122 ret
= core
->ops
->debug_init(core
->hw
, core
->dentry
);
2131 debugfs_remove_recursive(core
->dentry
);
2132 core
->dentry
= NULL
;
2138 * clk_debug_register - add a clk node to the debugfs clk directory
2139 * @core: the clk being added to the debugfs clk directory
2141 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
2142 * initialized. Otherwise it bails out early since the debugfs clk directory
2143 * will be created lazily by clk_debug_init as part of a late_initcall.
2145 static int clk_debug_register(struct clk_core
*core
)
2149 mutex_lock(&clk_debug_lock
);
2150 hlist_add_head(&core
->debug_node
, &clk_debug_list
);
2155 ret
= clk_debug_create_one(core
, rootdir
);
2157 mutex_unlock(&clk_debug_lock
);
2163 * clk_debug_unregister - remove a clk node from the debugfs clk directory
2164 * @core: the clk being removed from the debugfs clk directory
2166 * Dynamically removes a clk and all its child nodes from the
2167 * debugfs clk directory if clk->dentry points to debugfs created by
2168 * clk_debug_register in __clk_core_init.
2170 static void clk_debug_unregister(struct clk_core
*core
)
2172 mutex_lock(&clk_debug_lock
);
2173 hlist_del_init(&core
->debug_node
);
2174 debugfs_remove_recursive(core
->dentry
);
2175 core
->dentry
= NULL
;
2176 mutex_unlock(&clk_debug_lock
);
2179 struct dentry
*clk_debugfs_add_file(struct clk_hw
*hw
, char *name
, umode_t mode
,
2180 void *data
, const struct file_operations
*fops
)
2182 struct dentry
*d
= NULL
;
2184 if (hw
->core
->dentry
)
2185 d
= debugfs_create_file(name
, mode
, hw
->core
->dentry
, data
,
2190 EXPORT_SYMBOL_GPL(clk_debugfs_add_file
);
2193 * clk_debug_init - lazily populate the debugfs clk directory
2195 * clks are often initialized very early during boot before memory can be
2196 * dynamically allocated and well before debugfs is setup. This function
2197 * populates the debugfs clk directory once at boot-time when we know that
2198 * debugfs is setup. It should only be called once at boot-time, all other clks
2199 * added dynamically will be done so with clk_debug_register.
2201 static int __init
clk_debug_init(void)
2203 struct clk_core
*core
;
2206 rootdir
= debugfs_create_dir("clk", NULL
);
2211 d
= debugfs_create_file("clk_summary", S_IRUGO
, rootdir
, &all_lists
,
2216 d
= debugfs_create_file("clk_dump", S_IRUGO
, rootdir
, &all_lists
,
2221 d
= debugfs_create_file("clk_orphan_summary", S_IRUGO
, rootdir
,
2222 &orphan_list
, &clk_summary_fops
);
2226 d
= debugfs_create_file("clk_orphan_dump", S_IRUGO
, rootdir
,
2227 &orphan_list
, &clk_dump_fops
);
2231 mutex_lock(&clk_debug_lock
);
2232 hlist_for_each_entry(core
, &clk_debug_list
, debug_node
)
2233 clk_debug_create_one(core
, rootdir
);
2236 mutex_unlock(&clk_debug_lock
);
2240 late_initcall(clk_debug_init
);
2242 static inline int clk_debug_register(struct clk_core
*core
) { return 0; }
2243 static inline void clk_debug_reparent(struct clk_core
*core
,
2244 struct clk_core
*new_parent
)
2247 static inline void clk_debug_unregister(struct clk_core
*core
)
2253 * __clk_core_init - initialize the data structures in a struct clk_core
2254 * @core: clk_core being initialized
2256 * Initializes the lists in struct clk_core, queries the hardware for the
2257 * parent and rate and sets them both.
2259 static int __clk_core_init(struct clk_core
*core
)
2262 struct clk_core
*orphan
;
2263 struct hlist_node
*tmp2
;
2271 /* check to see if a clock with this name is already registered */
2272 if (clk_core_lookup(core
->name
)) {
2273 pr_debug("%s: clk %s already initialized\n",
2274 __func__
, core
->name
);
2279 /* check that clk_ops are sane. See Documentation/clk.txt */
2280 if (core
->ops
->set_rate
&&
2281 !((core
->ops
->round_rate
|| core
->ops
->determine_rate
) &&
2282 core
->ops
->recalc_rate
)) {
2283 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
2284 __func__
, core
->name
);
2289 if (core
->ops
->set_parent
&& !core
->ops
->get_parent
) {
2290 pr_err("%s: %s must implement .get_parent & .set_parent\n",
2291 __func__
, core
->name
);
2296 if (core
->num_parents
> 1 && !core
->ops
->get_parent
) {
2297 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
2298 __func__
, core
->name
);
2303 if (core
->ops
->set_rate_and_parent
&&
2304 !(core
->ops
->set_parent
&& core
->ops
->set_rate
)) {
2305 pr_err("%s: %s must implement .set_parent & .set_rate\n",
2306 __func__
, core
->name
);
2311 /* throw a WARN if any entries in parent_names are NULL */
2312 for (i
= 0; i
< core
->num_parents
; i
++)
2313 WARN(!core
->parent_names
[i
],
2314 "%s: invalid NULL in %s's .parent_names\n",
2315 __func__
, core
->name
);
2317 core
->parent
= __clk_init_parent(core
);
2320 * Populate core->parent if parent has already been clk_core_init'd. If
2321 * parent has not yet been clk_core_init'd then place clk in the orphan
2322 * list. If clk doesn't have any parents then place it in the root
2325 * Every time a new clk is clk_init'd then we walk the list of orphan
2326 * clocks and re-parent any that are children of the clock currently
2330 hlist_add_head(&core
->child_node
,
2331 &core
->parent
->children
);
2332 core
->orphan
= core
->parent
->orphan
;
2333 } else if (!core
->num_parents
) {
2334 hlist_add_head(&core
->child_node
, &clk_root_list
);
2335 core
->orphan
= false;
2337 hlist_add_head(&core
->child_node
, &clk_orphan_list
);
2338 core
->orphan
= true;
2342 * Set clk's accuracy. The preferred method is to use
2343 * .recalc_accuracy. For simple clocks and lazy developers the default
2344 * fallback is to use the parent's accuracy. If a clock doesn't have a
2345 * parent (or is orphaned) then accuracy is set to zero (perfect
2348 if (core
->ops
->recalc_accuracy
)
2349 core
->accuracy
= core
->ops
->recalc_accuracy(core
->hw
,
2350 __clk_get_accuracy(core
->parent
));
2351 else if (core
->parent
)
2352 core
->accuracy
= core
->parent
->accuracy
;
2358 * Since a phase is by definition relative to its parent, just
2359 * query the current clock phase, or just assume it's in phase.
2361 if (core
->ops
->get_phase
)
2362 core
->phase
= core
->ops
->get_phase(core
->hw
);
2367 * Set clk's rate. The preferred method is to use .recalc_rate. For
2368 * simple clocks and lazy developers the default fallback is to use the
2369 * parent's rate. If a clock doesn't have a parent (or is orphaned)
2370 * then rate is set to zero.
2372 if (core
->ops
->recalc_rate
)
2373 rate
= core
->ops
->recalc_rate(core
->hw
,
2374 clk_core_get_rate_nolock(core
->parent
));
2375 else if (core
->parent
)
2376 rate
= core
->parent
->rate
;
2379 core
->rate
= core
->req_rate
= rate
;
2382 * walk the list of orphan clocks and reparent any that newly finds a
2385 hlist_for_each_entry_safe(orphan
, tmp2
, &clk_orphan_list
, child_node
) {
2386 struct clk_core
*parent
= __clk_init_parent(orphan
);
2389 clk_core_reparent(orphan
, parent
);
2393 * optional platform-specific magic
2395 * The .init callback is not used by any of the basic clock types, but
2396 * exists for weird hardware that must perform initialization magic.
2397 * Please consider other ways of solving initialization problems before
2398 * using this callback, as its use is discouraged.
2400 if (core
->ops
->init
)
2401 core
->ops
->init(core
->hw
);
2403 if (core
->flags
& CLK_IS_CRITICAL
) {
2404 unsigned long flags
;
2406 clk_core_prepare(core
);
2408 flags
= clk_enable_lock();
2409 clk_core_enable(core
);
2410 clk_enable_unlock(flags
);
2413 kref_init(&core
->ref
);
2415 clk_prepare_unlock();
2418 clk_debug_register(core
);
2423 struct clk
*__clk_create_clk(struct clk_hw
*hw
, const char *dev_id
,
2428 /* This is to allow this function to be chained to others */
2429 if (IS_ERR_OR_NULL(hw
))
2430 return (struct clk
*) hw
;
2432 clk
= kzalloc(sizeof(*clk
), GFP_KERNEL
);
2434 return ERR_PTR(-ENOMEM
);
2436 clk
->core
= hw
->core
;
2437 clk
->dev_id
= dev_id
;
2438 clk
->con_id
= con_id
;
2439 clk
->max_rate
= ULONG_MAX
;
2442 hlist_add_head(&clk
->clks_node
, &hw
->core
->clks
);
2443 clk_prepare_unlock();
2448 void __clk_free_clk(struct clk
*clk
)
2451 hlist_del(&clk
->clks_node
);
2452 clk_prepare_unlock();
2458 * clk_register - allocate a new clock, register it and return an opaque cookie
2459 * @dev: device that is registering this clock
2460 * @hw: link to hardware-specific clock data
2462 * clk_register is the primary interface for populating the clock tree with new
2463 * clock nodes. It returns a pointer to the newly allocated struct clk which
2464 * cannot be dereferenced by driver code but may be used in conjunction with the
2465 * rest of the clock API. In the event of an error clk_register will return an
2466 * error code; drivers must test for an error code after calling clk_register.
2468 struct clk
*clk_register(struct device
*dev
, struct clk_hw
*hw
)
2471 struct clk_core
*core
;
2473 core
= kzalloc(sizeof(*core
), GFP_KERNEL
);
2479 core
->name
= kstrdup_const(hw
->init
->name
, GFP_KERNEL
);
2484 core
->ops
= hw
->init
->ops
;
2485 if (dev
&& dev
->driver
)
2486 core
->owner
= dev
->driver
->owner
;
2488 core
->flags
= hw
->init
->flags
;
2489 core
->num_parents
= hw
->init
->num_parents
;
2491 core
->max_rate
= ULONG_MAX
;
2494 /* allocate local copy in case parent_names is __initdata */
2495 core
->parent_names
= kcalloc(core
->num_parents
, sizeof(char *),
2498 if (!core
->parent_names
) {
2500 goto fail_parent_names
;
2504 /* copy each string name in case parent_names is __initdata */
2505 for (i
= 0; i
< core
->num_parents
; i
++) {
2506 core
->parent_names
[i
] = kstrdup_const(hw
->init
->parent_names
[i
],
2508 if (!core
->parent_names
[i
]) {
2510 goto fail_parent_names_copy
;
2514 /* avoid unnecessary string look-ups of clk_core's possible parents. */
2515 core
->parents
= kcalloc(core
->num_parents
, sizeof(*core
->parents
),
2517 if (!core
->parents
) {
2522 INIT_HLIST_HEAD(&core
->clks
);
2524 hw
->clk
= __clk_create_clk(hw
, NULL
, NULL
);
2525 if (IS_ERR(hw
->clk
)) {
2526 ret
= PTR_ERR(hw
->clk
);
2530 ret
= __clk_core_init(core
);
2534 __clk_free_clk(hw
->clk
);
2538 kfree(core
->parents
);
2539 fail_parent_names_copy
:
2541 kfree_const(core
->parent_names
[i
]);
2542 kfree(core
->parent_names
);
2544 kfree_const(core
->name
);
2548 return ERR_PTR(ret
);
2550 EXPORT_SYMBOL_GPL(clk_register
);
2553 * clk_hw_register - register a clk_hw and return an error code
2554 * @dev: device that is registering this clock
2555 * @hw: link to hardware-specific clock data
2557 * clk_hw_register is the primary interface for populating the clock tree with
2558 * new clock nodes. It returns an integer equal to zero indicating success or
2559 * less than zero indicating failure. Drivers must test for an error code after
2560 * calling clk_hw_register().
2562 int clk_hw_register(struct device
*dev
, struct clk_hw
*hw
)
2564 return PTR_ERR_OR_ZERO(clk_register(dev
, hw
));
2566 EXPORT_SYMBOL_GPL(clk_hw_register
);
2568 /* Free memory allocated for a clock. */
2569 static void __clk_release(struct kref
*ref
)
2571 struct clk_core
*core
= container_of(ref
, struct clk_core
, ref
);
2572 int i
= core
->num_parents
;
2574 lockdep_assert_held(&prepare_lock
);
2576 kfree(core
->parents
);
2578 kfree_const(core
->parent_names
[i
]);
2580 kfree(core
->parent_names
);
2581 kfree_const(core
->name
);
2586 * Empty clk_ops for unregistered clocks. These are used temporarily
2587 * after clk_unregister() was called on a clock and until last clock
2588 * consumer calls clk_put() and the struct clk object is freed.
2590 static int clk_nodrv_prepare_enable(struct clk_hw
*hw
)
2595 static void clk_nodrv_disable_unprepare(struct clk_hw
*hw
)
2600 static int clk_nodrv_set_rate(struct clk_hw
*hw
, unsigned long rate
,
2601 unsigned long parent_rate
)
2606 static int clk_nodrv_set_parent(struct clk_hw
*hw
, u8 index
)
2611 static const struct clk_ops clk_nodrv_ops
= {
2612 .enable
= clk_nodrv_prepare_enable
,
2613 .disable
= clk_nodrv_disable_unprepare
,
2614 .prepare
= clk_nodrv_prepare_enable
,
2615 .unprepare
= clk_nodrv_disable_unprepare
,
2616 .set_rate
= clk_nodrv_set_rate
,
2617 .set_parent
= clk_nodrv_set_parent
,
2621 * clk_unregister - unregister a currently registered clock
2622 * @clk: clock to unregister
2624 void clk_unregister(struct clk
*clk
)
2626 unsigned long flags
;
2628 if (!clk
|| WARN_ON_ONCE(IS_ERR(clk
)))
2631 clk_debug_unregister(clk
->core
);
2635 if (clk
->core
->ops
== &clk_nodrv_ops
) {
2636 pr_err("%s: unregistered clock: %s\n", __func__
,
2641 * Assign empty clock ops for consumers that might still hold
2642 * a reference to this clock.
2644 flags
= clk_enable_lock();
2645 clk
->core
->ops
= &clk_nodrv_ops
;
2646 clk_enable_unlock(flags
);
2648 if (!hlist_empty(&clk
->core
->children
)) {
2649 struct clk_core
*child
;
2650 struct hlist_node
*t
;
2652 /* Reparent all children to the orphan list. */
2653 hlist_for_each_entry_safe(child
, t
, &clk
->core
->children
,
2655 clk_core_set_parent(child
, NULL
);
2658 hlist_del_init(&clk
->core
->child_node
);
2660 if (clk
->core
->prepare_count
)
2661 pr_warn("%s: unregistering prepared clock: %s\n",
2662 __func__
, clk
->core
->name
);
2663 kref_put(&clk
->core
->ref
, __clk_release
);
2665 clk_prepare_unlock();
2667 EXPORT_SYMBOL_GPL(clk_unregister
);
2670 * clk_hw_unregister - unregister a currently registered clk_hw
2671 * @hw: hardware-specific clock data to unregister
2673 void clk_hw_unregister(struct clk_hw
*hw
)
2675 clk_unregister(hw
->clk
);
2677 EXPORT_SYMBOL_GPL(clk_hw_unregister
);
2679 static void devm_clk_release(struct device
*dev
, void *res
)
2681 clk_unregister(*(struct clk
**)res
);
2684 static void devm_clk_hw_release(struct device
*dev
, void *res
)
2686 clk_hw_unregister(*(struct clk_hw
**)res
);
2690 * devm_clk_register - resource managed clk_register()
2691 * @dev: device that is registering this clock
2692 * @hw: link to hardware-specific clock data
2694 * Managed clk_register(). Clocks returned from this function are
2695 * automatically clk_unregister()ed on driver detach. See clk_register() for
2698 struct clk
*devm_clk_register(struct device
*dev
, struct clk_hw
*hw
)
2703 clkp
= devres_alloc(devm_clk_release
, sizeof(*clkp
), GFP_KERNEL
);
2705 return ERR_PTR(-ENOMEM
);
2707 clk
= clk_register(dev
, hw
);
2710 devres_add(dev
, clkp
);
2717 EXPORT_SYMBOL_GPL(devm_clk_register
);
2720 * devm_clk_hw_register - resource managed clk_hw_register()
2721 * @dev: device that is registering this clock
2722 * @hw: link to hardware-specific clock data
2724 * Managed clk_hw_register(). Clocks registered by this function are
2725 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
2726 * for more information.
2728 int devm_clk_hw_register(struct device
*dev
, struct clk_hw
*hw
)
2730 struct clk_hw
**hwp
;
2733 hwp
= devres_alloc(devm_clk_hw_release
, sizeof(*hwp
), GFP_KERNEL
);
2737 ret
= clk_hw_register(dev
, hw
);
2740 devres_add(dev
, hwp
);
2747 EXPORT_SYMBOL_GPL(devm_clk_hw_register
);
2749 static int devm_clk_match(struct device
*dev
, void *res
, void *data
)
2751 struct clk
*c
= res
;
2757 static int devm_clk_hw_match(struct device
*dev
, void *res
, void *data
)
2759 struct clk_hw
*hw
= res
;
2767 * devm_clk_unregister - resource managed clk_unregister()
2768 * @clk: clock to unregister
2770 * Deallocate a clock allocated with devm_clk_register(). Normally
2771 * this function will not need to be called and the resource management
2772 * code will ensure that the resource is freed.
2774 void devm_clk_unregister(struct device
*dev
, struct clk
*clk
)
2776 WARN_ON(devres_release(dev
, devm_clk_release
, devm_clk_match
, clk
));
2778 EXPORT_SYMBOL_GPL(devm_clk_unregister
);
2781 * devm_clk_hw_unregister - resource managed clk_hw_unregister()
2782 * @dev: device that is unregistering the hardware-specific clock data
2783 * @hw: link to hardware-specific clock data
2785 * Unregister a clk_hw registered with devm_clk_hw_register(). Normally
2786 * this function will not need to be called and the resource management
2787 * code will ensure that the resource is freed.
2789 void devm_clk_hw_unregister(struct device
*dev
, struct clk_hw
*hw
)
2791 WARN_ON(devres_release(dev
, devm_clk_hw_release
, devm_clk_hw_match
,
2794 EXPORT_SYMBOL_GPL(devm_clk_hw_unregister
);
2799 int __clk_get(struct clk
*clk
)
2801 struct clk_core
*core
= !clk
? NULL
: clk
->core
;
2804 if (!try_module_get(core
->owner
))
2807 kref_get(&core
->ref
);
2812 void __clk_put(struct clk
*clk
)
2814 struct module
*owner
;
2816 if (!clk
|| WARN_ON_ONCE(IS_ERR(clk
)))
2821 hlist_del(&clk
->clks_node
);
2822 if (clk
->min_rate
> clk
->core
->req_rate
||
2823 clk
->max_rate
< clk
->core
->req_rate
)
2824 clk_core_set_rate_nolock(clk
->core
, clk
->core
->req_rate
);
2826 owner
= clk
->core
->owner
;
2827 kref_put(&clk
->core
->ref
, __clk_release
);
2829 clk_prepare_unlock();
2836 /*** clk rate change notifiers ***/
2839 * clk_notifier_register - add a clk rate change notifier
2840 * @clk: struct clk * to watch
2841 * @nb: struct notifier_block * with callback info
2843 * Request notification when clk's rate changes. This uses an SRCU
2844 * notifier because we want it to block and notifier unregistrations are
2845 * uncommon. The callbacks associated with the notifier must not
2846 * re-enter into the clk framework by calling any top-level clk APIs;
2847 * this will cause a nested prepare_lock mutex.
2849 * In all notification cases (pre, post and abort rate change) the original
2850 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
2851 * and the new frequency is passed via struct clk_notifier_data.new_rate.
2853 * clk_notifier_register() must be called from non-atomic context.
2854 * Returns -EINVAL if called with null arguments, -ENOMEM upon
2855 * allocation failure; otherwise, passes along the return value of
2856 * srcu_notifier_chain_register().
2858 int clk_notifier_register(struct clk
*clk
, struct notifier_block
*nb
)
2860 struct clk_notifier
*cn
;
2868 /* search the list of notifiers for this clk */
2869 list_for_each_entry(cn
, &clk_notifier_list
, node
)
2873 /* if clk wasn't in the notifier list, allocate new clk_notifier */
2874 if (cn
->clk
!= clk
) {
2875 cn
= kzalloc(sizeof(struct clk_notifier
), GFP_KERNEL
);
2880 srcu_init_notifier_head(&cn
->notifier_head
);
2882 list_add(&cn
->node
, &clk_notifier_list
);
2885 ret
= srcu_notifier_chain_register(&cn
->notifier_head
, nb
);
2887 clk
->core
->notifier_count
++;
2890 clk_prepare_unlock();
2894 EXPORT_SYMBOL_GPL(clk_notifier_register
);
2897 * clk_notifier_unregister - remove a clk rate change notifier
2898 * @clk: struct clk *
2899 * @nb: struct notifier_block * with callback info
2901 * Request no further notification for changes to 'clk' and frees memory
2902 * allocated in clk_notifier_register.
2904 * Returns -EINVAL if called with null arguments; otherwise, passes
2905 * along the return value of srcu_notifier_chain_unregister().
2907 int clk_notifier_unregister(struct clk
*clk
, struct notifier_block
*nb
)
2909 struct clk_notifier
*cn
= NULL
;
2917 list_for_each_entry(cn
, &clk_notifier_list
, node
)
2921 if (cn
->clk
== clk
) {
2922 ret
= srcu_notifier_chain_unregister(&cn
->notifier_head
, nb
);
2924 clk
->core
->notifier_count
--;
2926 /* XXX the notifier code should handle this better */
2927 if (!cn
->notifier_head
.head
) {
2928 srcu_cleanup_notifier_head(&cn
->notifier_head
);
2929 list_del(&cn
->node
);
2937 clk_prepare_unlock();
2941 EXPORT_SYMBOL_GPL(clk_notifier_unregister
);
2945 * struct of_clk_provider - Clock provider registration structure
2946 * @link: Entry in global list of clock providers
2947 * @node: Pointer to device tree node of clock provider
2948 * @get: Get clock callback. Returns NULL or a struct clk for the
2949 * given clock specifier
2950 * @data: context pointer to be passed into @get callback
2952 struct of_clk_provider
{
2953 struct list_head link
;
2955 struct device_node
*node
;
2956 struct clk
*(*get
)(struct of_phandle_args
*clkspec
, void *data
);
2957 struct clk_hw
*(*get_hw
)(struct of_phandle_args
*clkspec
, void *data
);
2961 static const struct of_device_id __clk_of_table_sentinel
2962 __used
__section(__clk_of_table_end
);
2964 static LIST_HEAD(of_clk_providers
);
2965 static DEFINE_MUTEX(of_clk_mutex
);
2967 struct clk
*of_clk_src_simple_get(struct of_phandle_args
*clkspec
,
2972 EXPORT_SYMBOL_GPL(of_clk_src_simple_get
);
2974 struct clk_hw
*of_clk_hw_simple_get(struct of_phandle_args
*clkspec
, void *data
)
2978 EXPORT_SYMBOL_GPL(of_clk_hw_simple_get
);
2980 struct clk
*of_clk_src_onecell_get(struct of_phandle_args
*clkspec
, void *data
)
2982 struct clk_onecell_data
*clk_data
= data
;
2983 unsigned int idx
= clkspec
->args
[0];
2985 if (idx
>= clk_data
->clk_num
) {
2986 pr_err("%s: invalid clock index %u\n", __func__
, idx
);
2987 return ERR_PTR(-EINVAL
);
2990 return clk_data
->clks
[idx
];
2992 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get
);
2995 of_clk_hw_onecell_get(struct of_phandle_args
*clkspec
, void *data
)
2997 struct clk_hw_onecell_data
*hw_data
= data
;
2998 unsigned int idx
= clkspec
->args
[0];
3000 if (idx
>= hw_data
->num
) {
3001 pr_err("%s: invalid index %u\n", __func__
, idx
);
3002 return ERR_PTR(-EINVAL
);
3005 return hw_data
->hws
[idx
];
3007 EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get
);
3010 * of_clk_add_provider() - Register a clock provider for a node
3011 * @np: Device node pointer associated with clock provider
3012 * @clk_src_get: callback for decoding clock
3013 * @data: context pointer for @clk_src_get callback.
3015 int of_clk_add_provider(struct device_node
*np
,
3016 struct clk
*(*clk_src_get
)(struct of_phandle_args
*clkspec
,
3020 struct of_clk_provider
*cp
;
3023 cp
= kzalloc(sizeof(struct of_clk_provider
), GFP_KERNEL
);
3027 cp
->node
= of_node_get(np
);
3029 cp
->get
= clk_src_get
;
3031 mutex_lock(&of_clk_mutex
);
3032 list_add(&cp
->link
, &of_clk_providers
);
3033 mutex_unlock(&of_clk_mutex
);
3034 pr_debug("Added clock from %s\n", np
->full_name
);
3036 ret
= of_clk_set_defaults(np
, true);
3038 of_clk_del_provider(np
);
3042 EXPORT_SYMBOL_GPL(of_clk_add_provider
);
3045 * of_clk_add_hw_provider() - Register a clock provider for a node
3046 * @np: Device node pointer associated with clock provider
3047 * @get: callback for decoding clk_hw
3048 * @data: context pointer for @get callback.
3050 int of_clk_add_hw_provider(struct device_node
*np
,
3051 struct clk_hw
*(*get
)(struct of_phandle_args
*clkspec
,
3055 struct of_clk_provider
*cp
;
3058 cp
= kzalloc(sizeof(*cp
), GFP_KERNEL
);
3062 cp
->node
= of_node_get(np
);
3066 mutex_lock(&of_clk_mutex
);
3067 list_add(&cp
->link
, &of_clk_providers
);
3068 mutex_unlock(&of_clk_mutex
);
3069 pr_debug("Added clk_hw provider from %s\n", np
->full_name
);
3071 ret
= of_clk_set_defaults(np
, true);
3073 of_clk_del_provider(np
);
3077 EXPORT_SYMBOL_GPL(of_clk_add_hw_provider
);
3080 * of_clk_del_provider() - Remove a previously registered clock provider
3081 * @np: Device node pointer associated with clock provider
3083 void of_clk_del_provider(struct device_node
*np
)
3085 struct of_clk_provider
*cp
;
3087 mutex_lock(&of_clk_mutex
);
3088 list_for_each_entry(cp
, &of_clk_providers
, link
) {
3089 if (cp
->node
== np
) {
3090 list_del(&cp
->link
);
3091 of_node_put(cp
->node
);
3096 mutex_unlock(&of_clk_mutex
);
3098 EXPORT_SYMBOL_GPL(of_clk_del_provider
);
3100 static struct clk_hw
*
3101 __of_clk_get_hw_from_provider(struct of_clk_provider
*provider
,
3102 struct of_phandle_args
*clkspec
)
3105 struct clk_hw
*hw
= ERR_PTR(-EPROBE_DEFER
);
3107 if (provider
->get_hw
) {
3108 hw
= provider
->get_hw(clkspec
, provider
->data
);
3109 } else if (provider
->get
) {
3110 clk
= provider
->get(clkspec
, provider
->data
);
3112 hw
= __clk_get_hw(clk
);
3120 struct clk
*__of_clk_get_from_provider(struct of_phandle_args
*clkspec
,
3121 const char *dev_id
, const char *con_id
)
3123 struct of_clk_provider
*provider
;
3124 struct clk
*clk
= ERR_PTR(-EPROBE_DEFER
);
3125 struct clk_hw
*hw
= ERR_PTR(-EPROBE_DEFER
);
3128 return ERR_PTR(-EINVAL
);
3130 /* Check if we have such a provider in our array */
3131 mutex_lock(&of_clk_mutex
);
3132 list_for_each_entry(provider
, &of_clk_providers
, link
) {
3133 if (provider
->node
== clkspec
->np
)
3134 hw
= __of_clk_get_hw_from_provider(provider
, clkspec
);
3136 clk
= __clk_create_clk(hw
, dev_id
, con_id
);
3138 if (!IS_ERR(clk
) && !__clk_get(clk
)) {
3139 __clk_free_clk(clk
);
3140 clk
= ERR_PTR(-ENOENT
);
3146 mutex_unlock(&of_clk_mutex
);
3152 * of_clk_get_from_provider() - Lookup a clock from a clock provider
3153 * @clkspec: pointer to a clock specifier data structure
3155 * This function looks up a struct clk from the registered list of clock
3156 * providers, an input is a clock specifier data structure as returned
3157 * from the of_parse_phandle_with_args() function call.
3159 struct clk
*of_clk_get_from_provider(struct of_phandle_args
*clkspec
)
3161 return __of_clk_get_from_provider(clkspec
, NULL
, __func__
);
3163 EXPORT_SYMBOL_GPL(of_clk_get_from_provider
);
3166 * of_clk_get_parent_count() - Count the number of clocks a device node has
3167 * @np: device node to count
3169 * Returns: The number of clocks that are possible parents of this node
3171 unsigned int of_clk_get_parent_count(struct device_node
*np
)
3175 count
= of_count_phandle_with_args(np
, "clocks", "#clock-cells");
3181 EXPORT_SYMBOL_GPL(of_clk_get_parent_count
);
3183 const char *of_clk_get_parent_name(struct device_node
*np
, int index
)
3185 struct of_phandle_args clkspec
;
3186 struct property
*prop
;
3187 const char *clk_name
;
3194 rc
= of_parse_phandle_with_args(np
, "clocks", "#clock-cells", index
,
3199 index
= clkspec
.args_count
? clkspec
.args
[0] : 0;
3202 /* if there is an indices property, use it to transfer the index
3203 * specified into an array offset for the clock-output-names property.
3205 of_property_for_each_u32(clkspec
.np
, "clock-indices", prop
, vp
, pv
) {
3212 /* We went off the end of 'clock-indices' without finding it */
3216 if (of_property_read_string_index(clkspec
.np
, "clock-output-names",
3220 * Best effort to get the name if the clock has been
3221 * registered with the framework. If the clock isn't
3222 * registered, we return the node name as the name of
3223 * the clock as long as #clock-cells = 0.
3225 clk
= of_clk_get_from_provider(&clkspec
);
3227 if (clkspec
.args_count
== 0)
3228 clk_name
= clkspec
.np
->name
;
3232 clk_name
= __clk_get_name(clk
);
3238 of_node_put(clkspec
.np
);
3241 EXPORT_SYMBOL_GPL(of_clk_get_parent_name
);
3244 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
3246 * @np: Device node pointer associated with clock provider
3247 * @parents: pointer to char array that hold the parents' names
3248 * @size: size of the @parents array
3250 * Return: number of parents for the clock node.
3252 int of_clk_parent_fill(struct device_node
*np
, const char **parents
,
3257 while (i
< size
&& (parents
[i
] = of_clk_get_parent_name(np
, i
)) != NULL
)
3262 EXPORT_SYMBOL_GPL(of_clk_parent_fill
);
3264 struct clock_provider
{
3265 of_clk_init_cb_t clk_init_cb
;
3266 struct device_node
*np
;
3267 struct list_head node
;
3271 * This function looks for a parent clock. If there is one, then it
3272 * checks that the provider for this parent clock was initialized, in
3273 * this case the parent clock will be ready.
3275 static int parent_ready(struct device_node
*np
)
3280 struct clk
*clk
= of_clk_get(np
, i
);
3282 /* this parent is ready we can check the next one */
3289 /* at least one parent is not ready, we exit now */
3290 if (PTR_ERR(clk
) == -EPROBE_DEFER
)
3294 * Here we make assumption that the device tree is
3295 * written correctly. So an error means that there is
3296 * no more parent. As we didn't exit yet, then the
3297 * previous parent are ready. If there is no clock
3298 * parent, no need to wait for them, then we can
3299 * consider their absence as being ready
3306 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
3307 * @np: Device node pointer associated with clock provider
3308 * @index: clock index
3309 * @flags: pointer to clk_core->flags
3311 * Detects if the clock-critical property exists and, if so, sets the
3312 * corresponding CLK_IS_CRITICAL flag.
3314 * Do not use this function. It exists only for legacy Device Tree
3315 * bindings, such as the one-clock-per-node style that are outdated.
3316 * Those bindings typically put all clock data into .dts and the Linux
3317 * driver has no clock data, thus making it impossible to set this flag
3318 * correctly from the driver. Only those drivers may call
3319 * of_clk_detect_critical from their setup functions.
3321 * Return: error code or zero on success
3323 int of_clk_detect_critical(struct device_node
*np
,
3324 int index
, unsigned long *flags
)
3326 struct property
*prop
;
3333 of_property_for_each_u32(np
, "clock-critical", prop
, cur
, idx
)
3335 *flags
|= CLK_IS_CRITICAL
;
3341 * of_clk_init() - Scan and init clock providers from the DT
3342 * @matches: array of compatible values and init functions for providers.
3344 * This function scans the device tree for matching clock providers
3345 * and calls their initialization functions. It also does it by trying
3346 * to follow the dependencies.
3348 void __init
of_clk_init(const struct of_device_id
*matches
)
3350 const struct of_device_id
*match
;
3351 struct device_node
*np
;
3352 struct clock_provider
*clk_provider
, *next
;
3355 LIST_HEAD(clk_provider_list
);
3358 matches
= &__clk_of_table
;
3360 /* First prepare the list of the clocks providers */
3361 for_each_matching_node_and_match(np
, matches
, &match
) {
3362 struct clock_provider
*parent
;
3364 if (!of_device_is_available(np
))
3367 parent
= kzalloc(sizeof(*parent
), GFP_KERNEL
);
3369 list_for_each_entry_safe(clk_provider
, next
,
3370 &clk_provider_list
, node
) {
3371 list_del(&clk_provider
->node
);
3372 of_node_put(clk_provider
->np
);
3373 kfree(clk_provider
);
3379 parent
->clk_init_cb
= match
->data
;
3380 parent
->np
= of_node_get(np
);
3381 list_add_tail(&parent
->node
, &clk_provider_list
);
3384 while (!list_empty(&clk_provider_list
)) {
3385 is_init_done
= false;
3386 list_for_each_entry_safe(clk_provider
, next
,
3387 &clk_provider_list
, node
) {
3388 if (force
|| parent_ready(clk_provider
->np
)) {
3390 clk_provider
->clk_init_cb(clk_provider
->np
);
3391 of_clk_set_defaults(clk_provider
->np
, true);
3393 list_del(&clk_provider
->node
);
3394 of_node_put(clk_provider
->np
);
3395 kfree(clk_provider
);
3396 is_init_done
= true;
3401 * We didn't manage to initialize any of the
3402 * remaining providers during the last loop, so now we
3403 * initialize all the remaining ones unconditionally
3404 * in case the clock parent was not mandatory