1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
4 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
6 * Standard functionality for the common clock API. See Documentation/driver-api/clk.rst
10 #include <linux/clk-provider.h>
11 #include <linux/clk/clk-conf.h>
12 #include <linux/module.h>
13 #include <linux/mutex.h>
14 #include <linux/spinlock.h>
15 #include <linux/err.h>
16 #include <linux/list.h>
17 #include <linux/slab.h>
19 #include <linux/device.h>
20 #include <linux/init.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/sched.h>
23 #include <linux/clkdev.h>
27 static DEFINE_SPINLOCK(enable_lock
);
28 static DEFINE_MUTEX(prepare_lock
);
30 static struct task_struct
*prepare_owner
;
31 static struct task_struct
*enable_owner
;
33 static int prepare_refcnt
;
34 static int enable_refcnt
;
36 static HLIST_HEAD(clk_root_list
);
37 static HLIST_HEAD(clk_orphan_list
);
38 static LIST_HEAD(clk_notifier_list
);
40 static struct hlist_head
*all_lists
[] = {
46 /*** private data structures ***/
48 struct clk_parent_map
{
49 const struct clk_hw
*hw
;
50 struct clk_core
*core
;
58 const struct clk_ops
*ops
;
62 struct device_node
*of_node
;
63 struct clk_core
*parent
;
64 struct clk_parent_map
*parents
;
68 unsigned long req_rate
;
69 unsigned long new_rate
;
70 struct clk_core
*new_parent
;
71 struct clk_core
*new_child
;
75 unsigned int enable_count
;
76 unsigned int prepare_count
;
77 unsigned int protect_count
;
78 unsigned long min_rate
;
79 unsigned long max_rate
;
80 unsigned long accuracy
;
83 struct hlist_head children
;
84 struct hlist_node child_node
;
85 struct hlist_head clks
;
86 unsigned int notifier_count
;
87 #ifdef CONFIG_DEBUG_FS
88 struct dentry
*dentry
;
89 struct hlist_node debug_node
;
94 #define CREATE_TRACE_POINTS
95 #include <trace/events/clk.h>
98 struct clk_core
*core
;
102 unsigned long min_rate
;
103 unsigned long max_rate
;
104 unsigned int exclusive_count
;
105 struct hlist_node clks_node
;
109 static int clk_pm_runtime_get(struct clk_core
*core
)
113 if (!core
->rpm_enabled
)
116 ret
= pm_runtime_get_sync(core
->dev
);
118 pm_runtime_put_noidle(core
->dev
);
124 static void clk_pm_runtime_put(struct clk_core
*core
)
126 if (!core
->rpm_enabled
)
129 pm_runtime_put_sync(core
->dev
);
133 static void clk_prepare_lock(void)
135 if (!mutex_trylock(&prepare_lock
)) {
136 if (prepare_owner
== current
) {
140 mutex_lock(&prepare_lock
);
142 WARN_ON_ONCE(prepare_owner
!= NULL
);
143 WARN_ON_ONCE(prepare_refcnt
!= 0);
144 prepare_owner
= current
;
148 static void clk_prepare_unlock(void)
150 WARN_ON_ONCE(prepare_owner
!= current
);
151 WARN_ON_ONCE(prepare_refcnt
== 0);
153 if (--prepare_refcnt
)
155 prepare_owner
= NULL
;
156 mutex_unlock(&prepare_lock
);
159 static unsigned long clk_enable_lock(void)
160 __acquires(enable_lock
)
165 * On UP systems, spin_trylock_irqsave() always returns true, even if
166 * we already hold the lock. So, in that case, we rely only on
167 * reference counting.
169 if (!IS_ENABLED(CONFIG_SMP
) ||
170 !spin_trylock_irqsave(&enable_lock
, flags
)) {
171 if (enable_owner
== current
) {
173 __acquire(enable_lock
);
174 if (!IS_ENABLED(CONFIG_SMP
))
175 local_save_flags(flags
);
178 spin_lock_irqsave(&enable_lock
, flags
);
180 WARN_ON_ONCE(enable_owner
!= NULL
);
181 WARN_ON_ONCE(enable_refcnt
!= 0);
182 enable_owner
= current
;
187 static void clk_enable_unlock(unsigned long flags
)
188 __releases(enable_lock
)
190 WARN_ON_ONCE(enable_owner
!= current
);
191 WARN_ON_ONCE(enable_refcnt
== 0);
193 if (--enable_refcnt
) {
194 __release(enable_lock
);
198 spin_unlock_irqrestore(&enable_lock
, flags
);
201 static bool clk_core_rate_is_protected(struct clk_core
*core
)
203 return core
->protect_count
;
206 static bool clk_core_is_prepared(struct clk_core
*core
)
211 * .is_prepared is optional for clocks that can prepare
212 * fall back to software usage counter if it is missing
214 if (!core
->ops
->is_prepared
)
215 return core
->prepare_count
;
217 if (!clk_pm_runtime_get(core
)) {
218 ret
= core
->ops
->is_prepared(core
->hw
);
219 clk_pm_runtime_put(core
);
225 static bool clk_core_is_enabled(struct clk_core
*core
)
230 * .is_enabled is only mandatory for clocks that gate
231 * fall back to software usage counter if .is_enabled is missing
233 if (!core
->ops
->is_enabled
)
234 return core
->enable_count
;
237 * Check if clock controller's device is runtime active before
238 * calling .is_enabled callback. If not, assume that clock is
239 * disabled, because we might be called from atomic context, from
240 * which pm_runtime_get() is not allowed.
241 * This function is called mainly from clk_disable_unused_subtree,
242 * which ensures proper runtime pm activation of controller before
243 * taking enable spinlock, but the below check is needed if one tries
244 * to call it from other places.
246 if (core
->rpm_enabled
) {
247 pm_runtime_get_noresume(core
->dev
);
248 if (!pm_runtime_active(core
->dev
)) {
254 ret
= core
->ops
->is_enabled(core
->hw
);
256 if (core
->rpm_enabled
)
257 pm_runtime_put(core
->dev
);
262 /*** helper functions ***/
264 const char *__clk_get_name(const struct clk
*clk
)
266 return !clk
? NULL
: clk
->core
->name
;
268 EXPORT_SYMBOL_GPL(__clk_get_name
);
270 const char *clk_hw_get_name(const struct clk_hw
*hw
)
272 return hw
->core
->name
;
274 EXPORT_SYMBOL_GPL(clk_hw_get_name
);
276 struct clk_hw
*__clk_get_hw(struct clk
*clk
)
278 return !clk
? NULL
: clk
->core
->hw
;
280 EXPORT_SYMBOL_GPL(__clk_get_hw
);
282 unsigned int clk_hw_get_num_parents(const struct clk_hw
*hw
)
284 return hw
->core
->num_parents
;
286 EXPORT_SYMBOL_GPL(clk_hw_get_num_parents
);
288 struct clk_hw
*clk_hw_get_parent(const struct clk_hw
*hw
)
290 return hw
->core
->parent
? hw
->core
->parent
->hw
: NULL
;
292 EXPORT_SYMBOL_GPL(clk_hw_get_parent
);
294 static struct clk_core
*__clk_lookup_subtree(const char *name
,
295 struct clk_core
*core
)
297 struct clk_core
*child
;
298 struct clk_core
*ret
;
300 if (!strcmp(core
->name
, name
))
303 hlist_for_each_entry(child
, &core
->children
, child_node
) {
304 ret
= __clk_lookup_subtree(name
, child
);
312 static struct clk_core
*clk_core_lookup(const char *name
)
314 struct clk_core
*root_clk
;
315 struct clk_core
*ret
;
320 /* search the 'proper' clk tree first */
321 hlist_for_each_entry(root_clk
, &clk_root_list
, child_node
) {
322 ret
= __clk_lookup_subtree(name
, root_clk
);
327 /* if not found, then search the orphan tree */
328 hlist_for_each_entry(root_clk
, &clk_orphan_list
, child_node
) {
329 ret
= __clk_lookup_subtree(name
, root_clk
);
338 static int of_parse_clkspec(const struct device_node
*np
, int index
,
339 const char *name
, struct of_phandle_args
*out_args
);
340 static struct clk_hw
*
341 of_clk_get_hw_from_clkspec(struct of_phandle_args
*clkspec
);
343 static inline int of_parse_clkspec(const struct device_node
*np
, int index
,
345 struct of_phandle_args
*out_args
)
349 static inline struct clk_hw
*
350 of_clk_get_hw_from_clkspec(struct of_phandle_args
*clkspec
)
352 return ERR_PTR(-ENOENT
);
357 * clk_core_get - Find the clk_core parent of a clk
358 * @core: clk to find parent of
359 * @p_index: parent index to search for
361 * This is the preferred method for clk providers to find the parent of a
362 * clk when that parent is external to the clk controller. The parent_names
363 * array is indexed and treated as a local name matching a string in the device
364 * node's 'clock-names' property or as the 'con_id' matching the device's
365 * dev_name() in a clk_lookup. This allows clk providers to use their own
366 * namespace instead of looking for a globally unique parent string.
368 * For example the following DT snippet would allow a clock registered by the
369 * clock-controller@c001 that has a clk_init_data::parent_data array
370 * with 'xtal' in the 'name' member to find the clock provided by the
371 * clock-controller@f00abcd without needing to get the globally unique name of
374 * parent: clock-controller@f00abcd {
375 * reg = <0xf00abcd 0xabcd>;
376 * #clock-cells = <0>;
379 * clock-controller@c001 {
380 * reg = <0xc001 0xf00d>;
381 * clocks = <&parent>;
382 * clock-names = "xtal";
383 * #clock-cells = <1>;
386 * Returns: -ENOENT when the provider can't be found or the clk doesn't
387 * exist in the provider or the name can't be found in the DT node or
388 * in a clkdev lookup. NULL when the provider knows about the clk but it
389 * isn't provided on this system.
390 * A valid clk_core pointer when the clk can be found in the provider.
392 static struct clk_core
*clk_core_get(struct clk_core
*core
, u8 p_index
)
394 const char *name
= core
->parents
[p_index
].fw_name
;
395 int index
= core
->parents
[p_index
].index
;
396 struct clk_hw
*hw
= ERR_PTR(-ENOENT
);
397 struct device
*dev
= core
->dev
;
398 const char *dev_id
= dev
? dev_name(dev
) : NULL
;
399 struct device_node
*np
= core
->of_node
;
400 struct of_phandle_args clkspec
;
402 if (np
&& (name
|| index
>= 0) &&
403 !of_parse_clkspec(np
, index
, name
, &clkspec
)) {
404 hw
= of_clk_get_hw_from_clkspec(&clkspec
);
405 of_node_put(clkspec
.np
);
408 * If the DT search above couldn't find the provider fallback to
409 * looking up via clkdev based clk_lookups.
411 hw
= clk_find_hw(dev_id
, name
);
420 static void clk_core_fill_parent_index(struct clk_core
*core
, u8 index
)
422 struct clk_parent_map
*entry
= &core
->parents
[index
];
423 struct clk_core
*parent
;
426 parent
= entry
->hw
->core
;
428 * We have a direct reference but it isn't registered yet?
429 * Orphan it and let clk_reparent() update the orphan status
430 * when the parent is registered.
433 parent
= ERR_PTR(-EPROBE_DEFER
);
435 parent
= clk_core_get(core
, index
);
436 if (PTR_ERR(parent
) == -ENOENT
&& entry
->name
)
437 parent
= clk_core_lookup(entry
->name
);
440 /* Only cache it if it's not an error */
442 entry
->core
= parent
;
445 static struct clk_core
*clk_core_get_parent_by_index(struct clk_core
*core
,
448 if (!core
|| index
>= core
->num_parents
|| !core
->parents
)
451 if (!core
->parents
[index
].core
)
452 clk_core_fill_parent_index(core
, index
);
454 return core
->parents
[index
].core
;
458 clk_hw_get_parent_by_index(const struct clk_hw
*hw
, unsigned int index
)
460 struct clk_core
*parent
;
462 parent
= clk_core_get_parent_by_index(hw
->core
, index
);
464 return !parent
? NULL
: parent
->hw
;
466 EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index
);
468 unsigned int __clk_get_enable_count(struct clk
*clk
)
470 return !clk
? 0 : clk
->core
->enable_count
;
473 static unsigned long clk_core_get_rate_nolock(struct clk_core
*core
)
478 if (!core
->num_parents
|| core
->parent
)
482 * Clk must have a parent because num_parents > 0 but the parent isn't
483 * known yet. Best to return 0 as the rate of this clk until we can
484 * properly recalc the rate based on the parent's rate.
489 unsigned long clk_hw_get_rate(const struct clk_hw
*hw
)
491 return clk_core_get_rate_nolock(hw
->core
);
493 EXPORT_SYMBOL_GPL(clk_hw_get_rate
);
495 static unsigned long clk_core_get_accuracy_no_lock(struct clk_core
*core
)
500 return core
->accuracy
;
503 unsigned long clk_hw_get_flags(const struct clk_hw
*hw
)
505 return hw
->core
->flags
;
507 EXPORT_SYMBOL_GPL(clk_hw_get_flags
);
509 bool clk_hw_is_prepared(const struct clk_hw
*hw
)
511 return clk_core_is_prepared(hw
->core
);
513 EXPORT_SYMBOL_GPL(clk_hw_is_prepared
);
515 bool clk_hw_rate_is_protected(const struct clk_hw
*hw
)
517 return clk_core_rate_is_protected(hw
->core
);
519 EXPORT_SYMBOL_GPL(clk_hw_rate_is_protected
);
521 bool clk_hw_is_enabled(const struct clk_hw
*hw
)
523 return clk_core_is_enabled(hw
->core
);
525 EXPORT_SYMBOL_GPL(clk_hw_is_enabled
);
527 bool __clk_is_enabled(struct clk
*clk
)
532 return clk_core_is_enabled(clk
->core
);
534 EXPORT_SYMBOL_GPL(__clk_is_enabled
);
536 static bool mux_is_better_rate(unsigned long rate
, unsigned long now
,
537 unsigned long best
, unsigned long flags
)
539 if (flags
& CLK_MUX_ROUND_CLOSEST
)
540 return abs(now
- rate
) < abs(best
- rate
);
542 return now
<= rate
&& now
> best
;
545 int clk_mux_determine_rate_flags(struct clk_hw
*hw
,
546 struct clk_rate_request
*req
,
549 struct clk_core
*core
= hw
->core
, *parent
, *best_parent
= NULL
;
550 int i
, num_parents
, ret
;
551 unsigned long best
= 0;
552 struct clk_rate_request parent_req
= *req
;
554 /* if NO_REPARENT flag set, pass through to current parent */
555 if (core
->flags
& CLK_SET_RATE_NO_REPARENT
) {
556 parent
= core
->parent
;
557 if (core
->flags
& CLK_SET_RATE_PARENT
) {
558 ret
= __clk_determine_rate(parent
? parent
->hw
: NULL
,
563 best
= parent_req
.rate
;
565 best
= clk_core_get_rate_nolock(parent
);
567 best
= clk_core_get_rate_nolock(core
);
573 /* find the parent that can provide the fastest rate <= rate */
574 num_parents
= core
->num_parents
;
575 for (i
= 0; i
< num_parents
; i
++) {
576 parent
= clk_core_get_parent_by_index(core
, i
);
580 if (core
->flags
& CLK_SET_RATE_PARENT
) {
582 ret
= __clk_determine_rate(parent
->hw
, &parent_req
);
586 parent_req
.rate
= clk_core_get_rate_nolock(parent
);
589 if (mux_is_better_rate(req
->rate
, parent_req
.rate
,
591 best_parent
= parent
;
592 best
= parent_req
.rate
;
601 req
->best_parent_hw
= best_parent
->hw
;
602 req
->best_parent_rate
= best
;
607 EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags
);
609 struct clk
*__clk_lookup(const char *name
)
611 struct clk_core
*core
= clk_core_lookup(name
);
613 return !core
? NULL
: core
->hw
->clk
;
616 static void clk_core_get_boundaries(struct clk_core
*core
,
617 unsigned long *min_rate
,
618 unsigned long *max_rate
)
620 struct clk
*clk_user
;
622 lockdep_assert_held(&prepare_lock
);
624 *min_rate
= core
->min_rate
;
625 *max_rate
= core
->max_rate
;
627 hlist_for_each_entry(clk_user
, &core
->clks
, clks_node
)
628 *min_rate
= max(*min_rate
, clk_user
->min_rate
);
630 hlist_for_each_entry(clk_user
, &core
->clks
, clks_node
)
631 *max_rate
= min(*max_rate
, clk_user
->max_rate
);
634 void clk_hw_set_rate_range(struct clk_hw
*hw
, unsigned long min_rate
,
635 unsigned long max_rate
)
637 hw
->core
->min_rate
= min_rate
;
638 hw
->core
->max_rate
= max_rate
;
640 EXPORT_SYMBOL_GPL(clk_hw_set_rate_range
);
643 * __clk_mux_determine_rate - clk_ops::determine_rate implementation for a mux type clk
644 * @hw: mux type clk to determine rate on
645 * @req: rate request, also used to return preferred parent and frequencies
647 * Helper for finding best parent to provide a given frequency. This can be used
648 * directly as a determine_rate callback (e.g. for a mux), or from a more
649 * complex clock that may combine a mux with other operations.
651 * Returns: 0 on success, -EERROR value on error
653 int __clk_mux_determine_rate(struct clk_hw
*hw
,
654 struct clk_rate_request
*req
)
656 return clk_mux_determine_rate_flags(hw
, req
, 0);
658 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate
);
660 int __clk_mux_determine_rate_closest(struct clk_hw
*hw
,
661 struct clk_rate_request
*req
)
663 return clk_mux_determine_rate_flags(hw
, req
, CLK_MUX_ROUND_CLOSEST
);
665 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest
);
669 static void clk_core_rate_unprotect(struct clk_core
*core
)
671 lockdep_assert_held(&prepare_lock
);
676 if (WARN(core
->protect_count
== 0,
677 "%s already unprotected\n", core
->name
))
680 if (--core
->protect_count
> 0)
683 clk_core_rate_unprotect(core
->parent
);
686 static int clk_core_rate_nuke_protect(struct clk_core
*core
)
690 lockdep_assert_held(&prepare_lock
);
695 if (core
->protect_count
== 0)
698 ret
= core
->protect_count
;
699 core
->protect_count
= 1;
700 clk_core_rate_unprotect(core
);
706 * clk_rate_exclusive_put - release exclusivity over clock rate control
707 * @clk: the clk over which the exclusivity is released
709 * clk_rate_exclusive_put() completes a critical section during which a clock
710 * consumer cannot tolerate any other consumer making any operation on the
711 * clock which could result in a rate change or rate glitch. Exclusive clocks
712 * cannot have their rate changed, either directly or indirectly due to changes
713 * further up the parent chain of clocks. As a result, clocks up parent chain
714 * also get under exclusive control of the calling consumer.
716 * If exlusivity is claimed more than once on clock, even by the same consumer,
717 * the rate effectively gets locked as exclusivity can't be preempted.
719 * Calls to clk_rate_exclusive_put() must be balanced with calls to
720 * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
723 void clk_rate_exclusive_put(struct clk
*clk
)
731 * if there is something wrong with this consumer protect count, stop
732 * here before messing with the provider
734 if (WARN_ON(clk
->exclusive_count
<= 0))
737 clk_core_rate_unprotect(clk
->core
);
738 clk
->exclusive_count
--;
740 clk_prepare_unlock();
742 EXPORT_SYMBOL_GPL(clk_rate_exclusive_put
);
744 static void clk_core_rate_protect(struct clk_core
*core
)
746 lockdep_assert_held(&prepare_lock
);
751 if (core
->protect_count
== 0)
752 clk_core_rate_protect(core
->parent
);
754 core
->protect_count
++;
757 static void clk_core_rate_restore_protect(struct clk_core
*core
, int count
)
759 lockdep_assert_held(&prepare_lock
);
767 clk_core_rate_protect(core
);
768 core
->protect_count
= count
;
772 * clk_rate_exclusive_get - get exclusivity over the clk rate control
773 * @clk: the clk over which the exclusity of rate control is requested
775 * clk_rate_exclusive_get() begins a critical section during which a clock
776 * consumer cannot tolerate any other consumer making any operation on the
777 * clock which could result in a rate change or rate glitch. Exclusive clocks
778 * cannot have their rate changed, either directly or indirectly due to changes
779 * further up the parent chain of clocks. As a result, clocks up parent chain
780 * also get under exclusive control of the calling consumer.
782 * If exlusivity is claimed more than once on clock, even by the same consumer,
783 * the rate effectively gets locked as exclusivity can't be preempted.
785 * Calls to clk_rate_exclusive_get() should be balanced with calls to
786 * clk_rate_exclusive_put(). Calls to this function may sleep.
787 * Returns 0 on success, -EERROR otherwise
789 int clk_rate_exclusive_get(struct clk
*clk
)
795 clk_core_rate_protect(clk
->core
);
796 clk
->exclusive_count
++;
797 clk_prepare_unlock();
801 EXPORT_SYMBOL_GPL(clk_rate_exclusive_get
);
803 static void clk_core_unprepare(struct clk_core
*core
)
805 lockdep_assert_held(&prepare_lock
);
810 if (WARN(core
->prepare_count
== 0,
811 "%s already unprepared\n", core
->name
))
814 if (WARN(core
->prepare_count
== 1 && core
->flags
& CLK_IS_CRITICAL
,
815 "Unpreparing critical %s\n", core
->name
))
818 if (core
->flags
& CLK_SET_RATE_GATE
)
819 clk_core_rate_unprotect(core
);
821 if (--core
->prepare_count
> 0)
824 WARN(core
->enable_count
> 0, "Unpreparing enabled %s\n", core
->name
);
826 trace_clk_unprepare(core
);
828 if (core
->ops
->unprepare
)
829 core
->ops
->unprepare(core
->hw
);
831 clk_pm_runtime_put(core
);
833 trace_clk_unprepare_complete(core
);
834 clk_core_unprepare(core
->parent
);
837 static void clk_core_unprepare_lock(struct clk_core
*core
)
840 clk_core_unprepare(core
);
841 clk_prepare_unlock();
845 * clk_unprepare - undo preparation of a clock source
846 * @clk: the clk being unprepared
848 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
849 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
850 * if the operation may sleep. One example is a clk which is accessed over
851 * I2c. In the complex case a clk gate operation may require a fast and a slow
852 * part. It is this reason that clk_unprepare and clk_disable are not mutually
853 * exclusive. In fact clk_disable must be called before clk_unprepare.
855 void clk_unprepare(struct clk
*clk
)
857 if (IS_ERR_OR_NULL(clk
))
860 clk_core_unprepare_lock(clk
->core
);
862 EXPORT_SYMBOL_GPL(clk_unprepare
);
864 static int clk_core_prepare(struct clk_core
*core
)
868 lockdep_assert_held(&prepare_lock
);
873 if (core
->prepare_count
== 0) {
874 ret
= clk_pm_runtime_get(core
);
878 ret
= clk_core_prepare(core
->parent
);
882 trace_clk_prepare(core
);
884 if (core
->ops
->prepare
)
885 ret
= core
->ops
->prepare(core
->hw
);
887 trace_clk_prepare_complete(core
);
893 core
->prepare_count
++;
896 * CLK_SET_RATE_GATE is a special case of clock protection
897 * Instead of a consumer claiming exclusive rate control, it is
898 * actually the provider which prevents any consumer from making any
899 * operation which could result in a rate change or rate glitch while
900 * the clock is prepared.
902 if (core
->flags
& CLK_SET_RATE_GATE
)
903 clk_core_rate_protect(core
);
907 clk_core_unprepare(core
->parent
);
909 clk_pm_runtime_put(core
);
913 static int clk_core_prepare_lock(struct clk_core
*core
)
918 ret
= clk_core_prepare(core
);
919 clk_prepare_unlock();
925 * clk_prepare - prepare a clock source
926 * @clk: the clk being prepared
928 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
929 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
930 * operation may sleep. One example is a clk which is accessed over I2c. In
931 * the complex case a clk ungate operation may require a fast and a slow part.
932 * It is this reason that clk_prepare and clk_enable are not mutually
933 * exclusive. In fact clk_prepare must be called before clk_enable.
934 * Returns 0 on success, -EERROR otherwise.
936 int clk_prepare(struct clk
*clk
)
941 return clk_core_prepare_lock(clk
->core
);
943 EXPORT_SYMBOL_GPL(clk_prepare
);
945 static void clk_core_disable(struct clk_core
*core
)
947 lockdep_assert_held(&enable_lock
);
952 if (WARN(core
->enable_count
== 0, "%s already disabled\n", core
->name
))
955 if (WARN(core
->enable_count
== 1 && core
->flags
& CLK_IS_CRITICAL
,
956 "Disabling critical %s\n", core
->name
))
959 if (--core
->enable_count
> 0)
962 trace_clk_disable_rcuidle(core
);
964 if (core
->ops
->disable
)
965 core
->ops
->disable(core
->hw
);
967 trace_clk_disable_complete_rcuidle(core
);
969 clk_core_disable(core
->parent
);
972 static void clk_core_disable_lock(struct clk_core
*core
)
976 flags
= clk_enable_lock();
977 clk_core_disable(core
);
978 clk_enable_unlock(flags
);
982 * clk_disable - gate a clock
983 * @clk: the clk being gated
985 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
986 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
987 * clk if the operation is fast and will never sleep. One example is a
988 * SoC-internal clk which is controlled via simple register writes. In the
989 * complex case a clk gate operation may require a fast and a slow part. It is
990 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
991 * In fact clk_disable must be called before clk_unprepare.
993 void clk_disable(struct clk
*clk
)
995 if (IS_ERR_OR_NULL(clk
))
998 clk_core_disable_lock(clk
->core
);
1000 EXPORT_SYMBOL_GPL(clk_disable
);
1002 static int clk_core_enable(struct clk_core
*core
)
1006 lockdep_assert_held(&enable_lock
);
1011 if (WARN(core
->prepare_count
== 0,
1012 "Enabling unprepared %s\n", core
->name
))
1015 if (core
->enable_count
== 0) {
1016 ret
= clk_core_enable(core
->parent
);
1021 trace_clk_enable_rcuidle(core
);
1023 if (core
->ops
->enable
)
1024 ret
= core
->ops
->enable(core
->hw
);
1026 trace_clk_enable_complete_rcuidle(core
);
1029 clk_core_disable(core
->parent
);
1034 core
->enable_count
++;
1038 static int clk_core_enable_lock(struct clk_core
*core
)
1040 unsigned long flags
;
1043 flags
= clk_enable_lock();
1044 ret
= clk_core_enable(core
);
1045 clk_enable_unlock(flags
);
1051 * clk_gate_restore_context - restore context for poweroff
1052 * @hw: the clk_hw pointer of clock whose state is to be restored
1054 * The clock gate restore context function enables or disables
1055 * the gate clocks based on the enable_count. This is done in cases
1056 * where the clock context is lost and based on the enable_count
1057 * the clock either needs to be enabled/disabled. This
1058 * helps restore the state of gate clocks.
1060 void clk_gate_restore_context(struct clk_hw
*hw
)
1062 struct clk_core
*core
= hw
->core
;
1064 if (core
->enable_count
)
1065 core
->ops
->enable(hw
);
1067 core
->ops
->disable(hw
);
1069 EXPORT_SYMBOL_GPL(clk_gate_restore_context
);
1071 static int clk_core_save_context(struct clk_core
*core
)
1073 struct clk_core
*child
;
1076 hlist_for_each_entry(child
, &core
->children
, child_node
) {
1077 ret
= clk_core_save_context(child
);
1082 if (core
->ops
&& core
->ops
->save_context
)
1083 ret
= core
->ops
->save_context(core
->hw
);
1088 static void clk_core_restore_context(struct clk_core
*core
)
1090 struct clk_core
*child
;
1092 if (core
->ops
&& core
->ops
->restore_context
)
1093 core
->ops
->restore_context(core
->hw
);
1095 hlist_for_each_entry(child
, &core
->children
, child_node
)
1096 clk_core_restore_context(child
);
1100 * clk_save_context - save clock context for poweroff
1102 * Saves the context of the clock register for powerstates in which the
1103 * contents of the registers will be lost. Occurs deep within the suspend
1104 * code. Returns 0 on success.
1106 int clk_save_context(void)
1108 struct clk_core
*clk
;
1111 hlist_for_each_entry(clk
, &clk_root_list
, child_node
) {
1112 ret
= clk_core_save_context(clk
);
1117 hlist_for_each_entry(clk
, &clk_orphan_list
, child_node
) {
1118 ret
= clk_core_save_context(clk
);
1125 EXPORT_SYMBOL_GPL(clk_save_context
);
1128 * clk_restore_context - restore clock context after poweroff
1130 * Restore the saved clock context upon resume.
1133 void clk_restore_context(void)
1135 struct clk_core
*core
;
1137 hlist_for_each_entry(core
, &clk_root_list
, child_node
)
1138 clk_core_restore_context(core
);
1140 hlist_for_each_entry(core
, &clk_orphan_list
, child_node
)
1141 clk_core_restore_context(core
);
1143 EXPORT_SYMBOL_GPL(clk_restore_context
);
1146 * clk_enable - ungate a clock
1147 * @clk: the clk being ungated
1149 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
1150 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
1151 * if the operation will never sleep. One example is a SoC-internal clk which
1152 * is controlled via simple register writes. In the complex case a clk ungate
1153 * operation may require a fast and a slow part. It is this reason that
1154 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
1155 * must be called before clk_enable. Returns 0 on success, -EERROR
1158 int clk_enable(struct clk
*clk
)
1163 return clk_core_enable_lock(clk
->core
);
1165 EXPORT_SYMBOL_GPL(clk_enable
);
1168 * clk_is_enabled_when_prepared - indicate if preparing a clock also enables it.
1169 * @clk: clock source
1171 * Returns true if clk_prepare() implicitly enables the clock, effectively
1172 * making clk_enable()/clk_disable() no-ops, false otherwise.
1174 * This is of interest mainly to power management code where actually
1175 * disabling the clock also requires unpreparing it to have any material
1178 * Regardless of the value returned here, the caller must always invoke
1179 * clk_enable() or clk_prepare_enable() and counterparts for usage counts
1182 bool clk_is_enabled_when_prepared(struct clk
*clk
)
1184 return clk
&& !(clk
->core
->ops
->enable
&& clk
->core
->ops
->disable
);
1186 EXPORT_SYMBOL_GPL(clk_is_enabled_when_prepared
);
1188 static int clk_core_prepare_enable(struct clk_core
*core
)
1192 ret
= clk_core_prepare_lock(core
);
1196 ret
= clk_core_enable_lock(core
);
1198 clk_core_unprepare_lock(core
);
1203 static void clk_core_disable_unprepare(struct clk_core
*core
)
1205 clk_core_disable_lock(core
);
1206 clk_core_unprepare_lock(core
);
1209 static void __init
clk_unprepare_unused_subtree(struct clk_core
*core
)
1211 struct clk_core
*child
;
1213 lockdep_assert_held(&prepare_lock
);
1215 hlist_for_each_entry(child
, &core
->children
, child_node
)
1216 clk_unprepare_unused_subtree(child
);
1218 if (core
->prepare_count
)
1221 if (core
->flags
& CLK_IGNORE_UNUSED
)
1224 if (clk_pm_runtime_get(core
))
1227 if (clk_core_is_prepared(core
)) {
1228 trace_clk_unprepare(core
);
1229 if (core
->ops
->unprepare_unused
)
1230 core
->ops
->unprepare_unused(core
->hw
);
1231 else if (core
->ops
->unprepare
)
1232 core
->ops
->unprepare(core
->hw
);
1233 trace_clk_unprepare_complete(core
);
1236 clk_pm_runtime_put(core
);
1239 static void __init
clk_disable_unused_subtree(struct clk_core
*core
)
1241 struct clk_core
*child
;
1242 unsigned long flags
;
1244 lockdep_assert_held(&prepare_lock
);
1246 hlist_for_each_entry(child
, &core
->children
, child_node
)
1247 clk_disable_unused_subtree(child
);
1249 if (core
->flags
& CLK_OPS_PARENT_ENABLE
)
1250 clk_core_prepare_enable(core
->parent
);
1252 if (clk_pm_runtime_get(core
))
1255 flags
= clk_enable_lock();
1257 if (core
->enable_count
)
1260 if (core
->flags
& CLK_IGNORE_UNUSED
)
1264 * some gate clocks have special needs during the disable-unused
1265 * sequence. call .disable_unused if available, otherwise fall
1268 if (clk_core_is_enabled(core
)) {
1269 trace_clk_disable(core
);
1270 if (core
->ops
->disable_unused
)
1271 core
->ops
->disable_unused(core
->hw
);
1272 else if (core
->ops
->disable
)
1273 core
->ops
->disable(core
->hw
);
1274 trace_clk_disable_complete(core
);
1278 clk_enable_unlock(flags
);
1279 clk_pm_runtime_put(core
);
1281 if (core
->flags
& CLK_OPS_PARENT_ENABLE
)
1282 clk_core_disable_unprepare(core
->parent
);
1285 static bool clk_ignore_unused __initdata
;
1286 static int __init
clk_ignore_unused_setup(char *__unused
)
1288 clk_ignore_unused
= true;
1291 __setup("clk_ignore_unused", clk_ignore_unused_setup
);
1293 static int __init
clk_disable_unused(void)
1295 struct clk_core
*core
;
1297 if (clk_ignore_unused
) {
1298 pr_warn("clk: Not disabling unused clocks\n");
1304 hlist_for_each_entry(core
, &clk_root_list
, child_node
)
1305 clk_disable_unused_subtree(core
);
1307 hlist_for_each_entry(core
, &clk_orphan_list
, child_node
)
1308 clk_disable_unused_subtree(core
);
1310 hlist_for_each_entry(core
, &clk_root_list
, child_node
)
1311 clk_unprepare_unused_subtree(core
);
1313 hlist_for_each_entry(core
, &clk_orphan_list
, child_node
)
1314 clk_unprepare_unused_subtree(core
);
1316 clk_prepare_unlock();
1320 late_initcall_sync(clk_disable_unused
);
1322 static int clk_core_determine_round_nolock(struct clk_core
*core
,
1323 struct clk_rate_request
*req
)
1327 lockdep_assert_held(&prepare_lock
);
1333 * At this point, core protection will be disabled
1334 * - if the provider is not protected at all
1335 * - if the calling consumer is the only one which has exclusivity
1338 if (clk_core_rate_is_protected(core
)) {
1339 req
->rate
= core
->rate
;
1340 } else if (core
->ops
->determine_rate
) {
1341 return core
->ops
->determine_rate(core
->hw
, req
);
1342 } else if (core
->ops
->round_rate
) {
1343 rate
= core
->ops
->round_rate(core
->hw
, req
->rate
,
1344 &req
->best_parent_rate
);
1356 static void clk_core_init_rate_req(struct clk_core
* const core
,
1357 struct clk_rate_request
*req
)
1359 struct clk_core
*parent
;
1361 if (WARN_ON(!core
|| !req
))
1364 parent
= core
->parent
;
1366 req
->best_parent_hw
= parent
->hw
;
1367 req
->best_parent_rate
= parent
->rate
;
1369 req
->best_parent_hw
= NULL
;
1370 req
->best_parent_rate
= 0;
1374 static bool clk_core_can_round(struct clk_core
* const core
)
1376 return core
->ops
->determine_rate
|| core
->ops
->round_rate
;
1379 static int clk_core_round_rate_nolock(struct clk_core
*core
,
1380 struct clk_rate_request
*req
)
1382 lockdep_assert_held(&prepare_lock
);
1389 clk_core_init_rate_req(core
, req
);
1391 if (clk_core_can_round(core
))
1392 return clk_core_determine_round_nolock(core
, req
);
1393 else if (core
->flags
& CLK_SET_RATE_PARENT
)
1394 return clk_core_round_rate_nolock(core
->parent
, req
);
1396 req
->rate
= core
->rate
;
1401 * __clk_determine_rate - get the closest rate actually supported by a clock
1402 * @hw: determine the rate of this clock
1403 * @req: target rate request
1405 * Useful for clk_ops such as .set_rate and .determine_rate.
1407 int __clk_determine_rate(struct clk_hw
*hw
, struct clk_rate_request
*req
)
1414 return clk_core_round_rate_nolock(hw
->core
, req
);
1416 EXPORT_SYMBOL_GPL(__clk_determine_rate
);
1419 * clk_hw_round_rate() - round the given rate for a hw clk
1420 * @hw: the hw clk for which we are rounding a rate
1421 * @rate: the rate which is to be rounded
1423 * Takes in a rate as input and rounds it to a rate that the clk can actually
1426 * Context: prepare_lock must be held.
1427 * For clk providers to call from within clk_ops such as .round_rate,
1430 * Return: returns rounded rate of hw clk if clk supports round_rate operation
1431 * else returns the parent rate.
1433 unsigned long clk_hw_round_rate(struct clk_hw
*hw
, unsigned long rate
)
1436 struct clk_rate_request req
;
1438 clk_core_get_boundaries(hw
->core
, &req
.min_rate
, &req
.max_rate
);
1441 ret
= clk_core_round_rate_nolock(hw
->core
, &req
);
1447 EXPORT_SYMBOL_GPL(clk_hw_round_rate
);
1450 * clk_round_rate - round the given rate for a clk
1451 * @clk: the clk for which we are rounding a rate
1452 * @rate: the rate which is to be rounded
1454 * Takes in a rate as input and rounds it to a rate that the clk can actually
1455 * use which is then returned. If clk doesn't support round_rate operation
1456 * then the parent rate is returned.
1458 long clk_round_rate(struct clk
*clk
, unsigned long rate
)
1460 struct clk_rate_request req
;
1468 if (clk
->exclusive_count
)
1469 clk_core_rate_unprotect(clk
->core
);
1471 clk_core_get_boundaries(clk
->core
, &req
.min_rate
, &req
.max_rate
);
1474 ret
= clk_core_round_rate_nolock(clk
->core
, &req
);
1476 if (clk
->exclusive_count
)
1477 clk_core_rate_protect(clk
->core
);
1479 clk_prepare_unlock();
1486 EXPORT_SYMBOL_GPL(clk_round_rate
);
1489 * __clk_notify - call clk notifier chain
1490 * @core: clk that is changing rate
1491 * @msg: clk notifier type (see include/linux/clk.h)
1492 * @old_rate: old clk rate
1493 * @new_rate: new clk rate
1495 * Triggers a notifier call chain on the clk rate-change notification
1496 * for 'clk'. Passes a pointer to the struct clk and the previous
1497 * and current rates to the notifier callback. Intended to be called by
1498 * internal clock code only. Returns NOTIFY_DONE from the last driver
1499 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1500 * a driver returns that.
1502 static int __clk_notify(struct clk_core
*core
, unsigned long msg
,
1503 unsigned long old_rate
, unsigned long new_rate
)
1505 struct clk_notifier
*cn
;
1506 struct clk_notifier_data cnd
;
1507 int ret
= NOTIFY_DONE
;
1509 cnd
.old_rate
= old_rate
;
1510 cnd
.new_rate
= new_rate
;
1512 list_for_each_entry(cn
, &clk_notifier_list
, node
) {
1513 if (cn
->clk
->core
== core
) {
1515 ret
= srcu_notifier_call_chain(&cn
->notifier_head
, msg
,
1517 if (ret
& NOTIFY_STOP_MASK
)
1526 * __clk_recalc_accuracies
1527 * @core: first clk in the subtree
1529 * Walks the subtree of clks starting with clk and recalculates accuracies as
1530 * it goes. Note that if a clk does not implement the .recalc_accuracy
1531 * callback then it is assumed that the clock will take on the accuracy of its
1534 static void __clk_recalc_accuracies(struct clk_core
*core
)
1536 unsigned long parent_accuracy
= 0;
1537 struct clk_core
*child
;
1539 lockdep_assert_held(&prepare_lock
);
1542 parent_accuracy
= core
->parent
->accuracy
;
1544 if (core
->ops
->recalc_accuracy
)
1545 core
->accuracy
= core
->ops
->recalc_accuracy(core
->hw
,
1548 core
->accuracy
= parent_accuracy
;
1550 hlist_for_each_entry(child
, &core
->children
, child_node
)
1551 __clk_recalc_accuracies(child
);
1554 static long clk_core_get_accuracy_recalc(struct clk_core
*core
)
1556 if (core
&& (core
->flags
& CLK_GET_ACCURACY_NOCACHE
))
1557 __clk_recalc_accuracies(core
);
1559 return clk_core_get_accuracy_no_lock(core
);
1563 * clk_get_accuracy - return the accuracy of clk
1564 * @clk: the clk whose accuracy is being returned
1566 * Simply returns the cached accuracy of the clk, unless
1567 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1569 * If clk is NULL then returns 0.
1571 long clk_get_accuracy(struct clk
*clk
)
1579 accuracy
= clk_core_get_accuracy_recalc(clk
->core
);
1580 clk_prepare_unlock();
1584 EXPORT_SYMBOL_GPL(clk_get_accuracy
);
1586 static unsigned long clk_recalc(struct clk_core
*core
,
1587 unsigned long parent_rate
)
1589 unsigned long rate
= parent_rate
;
1591 if (core
->ops
->recalc_rate
&& !clk_pm_runtime_get(core
)) {
1592 rate
= core
->ops
->recalc_rate(core
->hw
, parent_rate
);
1593 clk_pm_runtime_put(core
);
1599 * __clk_recalc_rates
1600 * @core: first clk in the subtree
1601 * @msg: notification type (see include/linux/clk.h)
1603 * Walks the subtree of clks starting with clk and recalculates rates as it
1604 * goes. Note that if a clk does not implement the .recalc_rate callback then
1605 * it is assumed that the clock will take on the rate of its parent.
1607 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1610 static void __clk_recalc_rates(struct clk_core
*core
, unsigned long msg
)
1612 unsigned long old_rate
;
1613 unsigned long parent_rate
= 0;
1614 struct clk_core
*child
;
1616 lockdep_assert_held(&prepare_lock
);
1618 old_rate
= core
->rate
;
1621 parent_rate
= core
->parent
->rate
;
1623 core
->rate
= clk_recalc(core
, parent_rate
);
1626 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1627 * & ABORT_RATE_CHANGE notifiers
1629 if (core
->notifier_count
&& msg
)
1630 __clk_notify(core
, msg
, old_rate
, core
->rate
);
1632 hlist_for_each_entry(child
, &core
->children
, child_node
)
1633 __clk_recalc_rates(child
, msg
);
1636 static unsigned long clk_core_get_rate_recalc(struct clk_core
*core
)
1638 if (core
&& (core
->flags
& CLK_GET_RATE_NOCACHE
))
1639 __clk_recalc_rates(core
, 0);
1641 return clk_core_get_rate_nolock(core
);
1645 * clk_get_rate - return the rate of clk
1646 * @clk: the clk whose rate is being returned
1648 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1649 * is set, which means a recalc_rate will be issued.
1650 * If clk is NULL then returns 0.
1652 unsigned long clk_get_rate(struct clk
*clk
)
1660 rate
= clk_core_get_rate_recalc(clk
->core
);
1661 clk_prepare_unlock();
1665 EXPORT_SYMBOL_GPL(clk_get_rate
);
1667 static int clk_fetch_parent_index(struct clk_core
*core
,
1668 struct clk_core
*parent
)
1675 for (i
= 0; i
< core
->num_parents
; i
++) {
1676 /* Found it first try! */
1677 if (core
->parents
[i
].core
== parent
)
1680 /* Something else is here, so keep looking */
1681 if (core
->parents
[i
].core
)
1684 /* Maybe core hasn't been cached but the hw is all we know? */
1685 if (core
->parents
[i
].hw
) {
1686 if (core
->parents
[i
].hw
== parent
->hw
)
1689 /* Didn't match, but we're expecting a clk_hw */
1693 /* Maybe it hasn't been cached (clk_set_parent() path) */
1694 if (parent
== clk_core_get(core
, i
))
1697 /* Fallback to comparing globally unique names */
1698 if (core
->parents
[i
].name
&&
1699 !strcmp(parent
->name
, core
->parents
[i
].name
))
1703 if (i
== core
->num_parents
)
1706 core
->parents
[i
].core
= parent
;
1711 * clk_hw_get_parent_index - return the index of the parent clock
1712 * @hw: clk_hw associated with the clk being consumed
1714 * Fetches and returns the index of parent clock. Returns -EINVAL if the given
1715 * clock does not have a current parent.
1717 int clk_hw_get_parent_index(struct clk_hw
*hw
)
1719 struct clk_hw
*parent
= clk_hw_get_parent(hw
);
1721 if (WARN_ON(parent
== NULL
))
1724 return clk_fetch_parent_index(hw
->core
, parent
->core
);
1726 EXPORT_SYMBOL_GPL(clk_hw_get_parent_index
);
1729 * Update the orphan status of @core and all its children.
1731 static void clk_core_update_orphan_status(struct clk_core
*core
, bool is_orphan
)
1733 struct clk_core
*child
;
1735 core
->orphan
= is_orphan
;
1737 hlist_for_each_entry(child
, &core
->children
, child_node
)
1738 clk_core_update_orphan_status(child
, is_orphan
);
1741 static void clk_reparent(struct clk_core
*core
, struct clk_core
*new_parent
)
1743 bool was_orphan
= core
->orphan
;
1745 hlist_del(&core
->child_node
);
1748 bool becomes_orphan
= new_parent
->orphan
;
1750 /* avoid duplicate POST_RATE_CHANGE notifications */
1751 if (new_parent
->new_child
== core
)
1752 new_parent
->new_child
= NULL
;
1754 hlist_add_head(&core
->child_node
, &new_parent
->children
);
1756 if (was_orphan
!= becomes_orphan
)
1757 clk_core_update_orphan_status(core
, becomes_orphan
);
1759 hlist_add_head(&core
->child_node
, &clk_orphan_list
);
1761 clk_core_update_orphan_status(core
, true);
1764 core
->parent
= new_parent
;
1767 static struct clk_core
*__clk_set_parent_before(struct clk_core
*core
,
1768 struct clk_core
*parent
)
1770 unsigned long flags
;
1771 struct clk_core
*old_parent
= core
->parent
;
1774 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
1776 * 2. Migrate prepare state between parents and prevent race with
1779 * If the clock is not prepared, then a race with
1780 * clk_enable/disable() is impossible since we already have the
1781 * prepare lock (future calls to clk_enable() need to be preceded by
1784 * If the clock is prepared, migrate the prepared state to the new
1785 * parent and also protect against a race with clk_enable() by
1786 * forcing the clock and the new parent on. This ensures that all
1787 * future calls to clk_enable() are practically NOPs with respect to
1788 * hardware and software states.
1790 * See also: Comment for clk_set_parent() below.
1793 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
1794 if (core
->flags
& CLK_OPS_PARENT_ENABLE
) {
1795 clk_core_prepare_enable(old_parent
);
1796 clk_core_prepare_enable(parent
);
1799 /* migrate prepare count if > 0 */
1800 if (core
->prepare_count
) {
1801 clk_core_prepare_enable(parent
);
1802 clk_core_enable_lock(core
);
1805 /* update the clk tree topology */
1806 flags
= clk_enable_lock();
1807 clk_reparent(core
, parent
);
1808 clk_enable_unlock(flags
);
1813 static void __clk_set_parent_after(struct clk_core
*core
,
1814 struct clk_core
*parent
,
1815 struct clk_core
*old_parent
)
1818 * Finish the migration of prepare state and undo the changes done
1819 * for preventing a race with clk_enable().
1821 if (core
->prepare_count
) {
1822 clk_core_disable_lock(core
);
1823 clk_core_disable_unprepare(old_parent
);
1826 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
1827 if (core
->flags
& CLK_OPS_PARENT_ENABLE
) {
1828 clk_core_disable_unprepare(parent
);
1829 clk_core_disable_unprepare(old_parent
);
1833 static int __clk_set_parent(struct clk_core
*core
, struct clk_core
*parent
,
1836 unsigned long flags
;
1838 struct clk_core
*old_parent
;
1840 old_parent
= __clk_set_parent_before(core
, parent
);
1842 trace_clk_set_parent(core
, parent
);
1844 /* change clock input source */
1845 if (parent
&& core
->ops
->set_parent
)
1846 ret
= core
->ops
->set_parent(core
->hw
, p_index
);
1848 trace_clk_set_parent_complete(core
, parent
);
1851 flags
= clk_enable_lock();
1852 clk_reparent(core
, old_parent
);
1853 clk_enable_unlock(flags
);
1854 __clk_set_parent_after(core
, old_parent
, parent
);
1859 __clk_set_parent_after(core
, parent
, old_parent
);
1865 * __clk_speculate_rates
1866 * @core: first clk in the subtree
1867 * @parent_rate: the "future" rate of clk's parent
1869 * Walks the subtree of clks starting with clk, speculating rates as it
1870 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1872 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1873 * pre-rate change notifications and returns early if no clks in the
1874 * subtree have subscribed to the notifications. Note that if a clk does not
1875 * implement the .recalc_rate callback then it is assumed that the clock will
1876 * take on the rate of its parent.
1878 static int __clk_speculate_rates(struct clk_core
*core
,
1879 unsigned long parent_rate
)
1881 struct clk_core
*child
;
1882 unsigned long new_rate
;
1883 int ret
= NOTIFY_DONE
;
1885 lockdep_assert_held(&prepare_lock
);
1887 new_rate
= clk_recalc(core
, parent_rate
);
1889 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1890 if (core
->notifier_count
)
1891 ret
= __clk_notify(core
, PRE_RATE_CHANGE
, core
->rate
, new_rate
);
1893 if (ret
& NOTIFY_STOP_MASK
) {
1894 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1895 __func__
, core
->name
, ret
);
1899 hlist_for_each_entry(child
, &core
->children
, child_node
) {
1900 ret
= __clk_speculate_rates(child
, new_rate
);
1901 if (ret
& NOTIFY_STOP_MASK
)
1909 static void clk_calc_subtree(struct clk_core
*core
, unsigned long new_rate
,
1910 struct clk_core
*new_parent
, u8 p_index
)
1912 struct clk_core
*child
;
1914 core
->new_rate
= new_rate
;
1915 core
->new_parent
= new_parent
;
1916 core
->new_parent_index
= p_index
;
1917 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1918 core
->new_child
= NULL
;
1919 if (new_parent
&& new_parent
!= core
->parent
)
1920 new_parent
->new_child
= core
;
1922 hlist_for_each_entry(child
, &core
->children
, child_node
) {
1923 child
->new_rate
= clk_recalc(child
, new_rate
);
1924 clk_calc_subtree(child
, child
->new_rate
, NULL
, 0);
1929 * calculate the new rates returning the topmost clock that has to be
1932 static struct clk_core
*clk_calc_new_rates(struct clk_core
*core
,
1935 struct clk_core
*top
= core
;
1936 struct clk_core
*old_parent
, *parent
;
1937 unsigned long best_parent_rate
= 0;
1938 unsigned long new_rate
;
1939 unsigned long min_rate
;
1940 unsigned long max_rate
;
1945 if (IS_ERR_OR_NULL(core
))
1948 /* save parent rate, if it exists */
1949 parent
= old_parent
= core
->parent
;
1951 best_parent_rate
= parent
->rate
;
1953 clk_core_get_boundaries(core
, &min_rate
, &max_rate
);
1955 /* find the closest rate and parent clk/rate */
1956 if (clk_core_can_round(core
)) {
1957 struct clk_rate_request req
;
1960 req
.min_rate
= min_rate
;
1961 req
.max_rate
= max_rate
;
1963 clk_core_init_rate_req(core
, &req
);
1965 ret
= clk_core_determine_round_nolock(core
, &req
);
1969 best_parent_rate
= req
.best_parent_rate
;
1970 new_rate
= req
.rate
;
1971 parent
= req
.best_parent_hw
? req
.best_parent_hw
->core
: NULL
;
1973 if (new_rate
< min_rate
|| new_rate
> max_rate
)
1975 } else if (!parent
|| !(core
->flags
& CLK_SET_RATE_PARENT
)) {
1976 /* pass-through clock without adjustable parent */
1977 core
->new_rate
= core
->rate
;
1980 /* pass-through clock with adjustable parent */
1981 top
= clk_calc_new_rates(parent
, rate
);
1982 new_rate
= parent
->new_rate
;
1986 /* some clocks must be gated to change parent */
1987 if (parent
!= old_parent
&&
1988 (core
->flags
& CLK_SET_PARENT_GATE
) && core
->prepare_count
) {
1989 pr_debug("%s: %s not gated but wants to reparent\n",
1990 __func__
, core
->name
);
1994 /* try finding the new parent index */
1995 if (parent
&& core
->num_parents
> 1) {
1996 p_index
= clk_fetch_parent_index(core
, parent
);
1998 pr_debug("%s: clk %s can not be parent of clk %s\n",
1999 __func__
, parent
->name
, core
->name
);
2004 if ((core
->flags
& CLK_SET_RATE_PARENT
) && parent
&&
2005 best_parent_rate
!= parent
->rate
)
2006 top
= clk_calc_new_rates(parent
, best_parent_rate
);
2009 clk_calc_subtree(core
, new_rate
, parent
, p_index
);
2015 * Notify about rate changes in a subtree. Always walk down the whole tree
2016 * so that in case of an error we can walk down the whole tree again and
2019 static struct clk_core
*clk_propagate_rate_change(struct clk_core
*core
,
2020 unsigned long event
)
2022 struct clk_core
*child
, *tmp_clk
, *fail_clk
= NULL
;
2023 int ret
= NOTIFY_DONE
;
2025 if (core
->rate
== core
->new_rate
)
2028 if (core
->notifier_count
) {
2029 ret
= __clk_notify(core
, event
, core
->rate
, core
->new_rate
);
2030 if (ret
& NOTIFY_STOP_MASK
)
2034 hlist_for_each_entry(child
, &core
->children
, child_node
) {
2035 /* Skip children who will be reparented to another clock */
2036 if (child
->new_parent
&& child
->new_parent
!= core
)
2038 tmp_clk
= clk_propagate_rate_change(child
, event
);
2043 /* handle the new child who might not be in core->children yet */
2044 if (core
->new_child
) {
2045 tmp_clk
= clk_propagate_rate_change(core
->new_child
, event
);
2054 * walk down a subtree and set the new rates notifying the rate
2057 static void clk_change_rate(struct clk_core
*core
)
2059 struct clk_core
*child
;
2060 struct hlist_node
*tmp
;
2061 unsigned long old_rate
;
2062 unsigned long best_parent_rate
= 0;
2063 bool skip_set_rate
= false;
2064 struct clk_core
*old_parent
;
2065 struct clk_core
*parent
= NULL
;
2067 old_rate
= core
->rate
;
2069 if (core
->new_parent
) {
2070 parent
= core
->new_parent
;
2071 best_parent_rate
= core
->new_parent
->rate
;
2072 } else if (core
->parent
) {
2073 parent
= core
->parent
;
2074 best_parent_rate
= core
->parent
->rate
;
2077 if (clk_pm_runtime_get(core
))
2080 if (core
->flags
& CLK_SET_RATE_UNGATE
) {
2081 clk_core_prepare(core
);
2082 clk_core_enable_lock(core
);
2085 if (core
->new_parent
&& core
->new_parent
!= core
->parent
) {
2086 old_parent
= __clk_set_parent_before(core
, core
->new_parent
);
2087 trace_clk_set_parent(core
, core
->new_parent
);
2089 if (core
->ops
->set_rate_and_parent
) {
2090 skip_set_rate
= true;
2091 core
->ops
->set_rate_and_parent(core
->hw
, core
->new_rate
,
2093 core
->new_parent_index
);
2094 } else if (core
->ops
->set_parent
) {
2095 core
->ops
->set_parent(core
->hw
, core
->new_parent_index
);
2098 trace_clk_set_parent_complete(core
, core
->new_parent
);
2099 __clk_set_parent_after(core
, core
->new_parent
, old_parent
);
2102 if (core
->flags
& CLK_OPS_PARENT_ENABLE
)
2103 clk_core_prepare_enable(parent
);
2105 trace_clk_set_rate(core
, core
->new_rate
);
2107 if (!skip_set_rate
&& core
->ops
->set_rate
)
2108 core
->ops
->set_rate(core
->hw
, core
->new_rate
, best_parent_rate
);
2110 trace_clk_set_rate_complete(core
, core
->new_rate
);
2112 core
->rate
= clk_recalc(core
, best_parent_rate
);
2114 if (core
->flags
& CLK_SET_RATE_UNGATE
) {
2115 clk_core_disable_lock(core
);
2116 clk_core_unprepare(core
);
2119 if (core
->flags
& CLK_OPS_PARENT_ENABLE
)
2120 clk_core_disable_unprepare(parent
);
2122 if (core
->notifier_count
&& old_rate
!= core
->rate
)
2123 __clk_notify(core
, POST_RATE_CHANGE
, old_rate
, core
->rate
);
2125 if (core
->flags
& CLK_RECALC_NEW_RATES
)
2126 (void)clk_calc_new_rates(core
, core
->new_rate
);
2129 * Use safe iteration, as change_rate can actually swap parents
2130 * for certain clock types.
2132 hlist_for_each_entry_safe(child
, tmp
, &core
->children
, child_node
) {
2133 /* Skip children who will be reparented to another clock */
2134 if (child
->new_parent
&& child
->new_parent
!= core
)
2136 clk_change_rate(child
);
2139 /* handle the new child who might not be in core->children yet */
2140 if (core
->new_child
)
2141 clk_change_rate(core
->new_child
);
2143 clk_pm_runtime_put(core
);
2146 static unsigned long clk_core_req_round_rate_nolock(struct clk_core
*core
,
2147 unsigned long req_rate
)
2150 struct clk_rate_request req
;
2152 lockdep_assert_held(&prepare_lock
);
2157 /* simulate what the rate would be if it could be freely set */
2158 cnt
= clk_core_rate_nuke_protect(core
);
2162 clk_core_get_boundaries(core
, &req
.min_rate
, &req
.max_rate
);
2163 req
.rate
= req_rate
;
2165 ret
= clk_core_round_rate_nolock(core
, &req
);
2167 /* restore the protection */
2168 clk_core_rate_restore_protect(core
, cnt
);
2170 return ret
? 0 : req
.rate
;
2173 static int clk_core_set_rate_nolock(struct clk_core
*core
,
2174 unsigned long req_rate
)
2176 struct clk_core
*top
, *fail_clk
;
2183 rate
= clk_core_req_round_rate_nolock(core
, req_rate
);
2185 /* bail early if nothing to do */
2186 if (rate
== clk_core_get_rate_nolock(core
))
2189 /* fail on a direct rate set of a protected provider */
2190 if (clk_core_rate_is_protected(core
))
2193 /* calculate new rates and get the topmost changed clock */
2194 top
= clk_calc_new_rates(core
, req_rate
);
2198 ret
= clk_pm_runtime_get(core
);
2202 /* notify that we are about to change rates */
2203 fail_clk
= clk_propagate_rate_change(top
, PRE_RATE_CHANGE
);
2205 pr_debug("%s: failed to set %s rate\n", __func__
,
2207 clk_propagate_rate_change(top
, ABORT_RATE_CHANGE
);
2212 /* change the rates */
2213 clk_change_rate(top
);
2215 core
->req_rate
= req_rate
;
2217 clk_pm_runtime_put(core
);
2223 * clk_set_rate - specify a new rate for clk
2224 * @clk: the clk whose rate is being changed
2225 * @rate: the new rate for clk
2227 * In the simplest case clk_set_rate will only adjust the rate of clk.
2229 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
2230 * propagate up to clk's parent; whether or not this happens depends on the
2231 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
2232 * after calling .round_rate then upstream parent propagation is ignored. If
2233 * *parent_rate comes back with a new rate for clk's parent then we propagate
2234 * up to clk's parent and set its rate. Upward propagation will continue
2235 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
2236 * .round_rate stops requesting changes to clk's parent_rate.
2238 * Rate changes are accomplished via tree traversal that also recalculates the
2239 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
2241 * Returns 0 on success, -EERROR otherwise.
2243 int clk_set_rate(struct clk
*clk
, unsigned long rate
)
2250 /* prevent racing with updates to the clock topology */
2253 if (clk
->exclusive_count
)
2254 clk_core_rate_unprotect(clk
->core
);
2256 ret
= clk_core_set_rate_nolock(clk
->core
, rate
);
2258 if (clk
->exclusive_count
)
2259 clk_core_rate_protect(clk
->core
);
2261 clk_prepare_unlock();
2265 EXPORT_SYMBOL_GPL(clk_set_rate
);
2268 * clk_set_rate_exclusive - specify a new rate and get exclusive control
2269 * @clk: the clk whose rate is being changed
2270 * @rate: the new rate for clk
2272 * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
2273 * within a critical section
2275 * This can be used initially to ensure that at least 1 consumer is
2276 * satisfied when several consumers are competing for exclusivity over the
2277 * same clock provider.
2279 * The exclusivity is not applied if setting the rate failed.
2281 * Calls to clk_rate_exclusive_get() should be balanced with calls to
2282 * clk_rate_exclusive_put().
2284 * Returns 0 on success, -EERROR otherwise.
2286 int clk_set_rate_exclusive(struct clk
*clk
, unsigned long rate
)
2293 /* prevent racing with updates to the clock topology */
2297 * The temporary protection removal is not here, on purpose
2298 * This function is meant to be used instead of clk_rate_protect,
2299 * so before the consumer code path protect the clock provider
2302 ret
= clk_core_set_rate_nolock(clk
->core
, rate
);
2304 clk_core_rate_protect(clk
->core
);
2305 clk
->exclusive_count
++;
2308 clk_prepare_unlock();
2312 EXPORT_SYMBOL_GPL(clk_set_rate_exclusive
);
2315 * clk_set_rate_range - set a rate range for a clock source
2316 * @clk: clock source
2317 * @min: desired minimum clock rate in Hz, inclusive
2318 * @max: desired maximum clock rate in Hz, inclusive
2320 * Returns success (0) or negative errno.
2322 int clk_set_rate_range(struct clk
*clk
, unsigned long min
, unsigned long max
)
2325 unsigned long old_min
, old_max
, rate
;
2330 trace_clk_set_rate_range(clk
->core
, min
, max
);
2333 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
2334 __func__
, clk
->core
->name
, clk
->dev_id
, clk
->con_id
,
2341 if (clk
->exclusive_count
)
2342 clk_core_rate_unprotect(clk
->core
);
2344 /* Save the current values in case we need to rollback the change */
2345 old_min
= clk
->min_rate
;
2346 old_max
= clk
->max_rate
;
2347 clk
->min_rate
= min
;
2348 clk
->max_rate
= max
;
2350 rate
= clk_core_get_rate_nolock(clk
->core
);
2351 if (rate
< min
|| rate
> max
) {
2354 * We are in bit of trouble here, current rate is outside the
2355 * the requested range. We are going try to request appropriate
2356 * range boundary but there is a catch. It may fail for the
2357 * usual reason (clock broken, clock protected, etc) but also
2359 * - round_rate() was not favorable and fell on the wrong
2360 * side of the boundary
2361 * - the determine_rate() callback does not really check for
2362 * this corner case when determining the rate
2370 ret
= clk_core_set_rate_nolock(clk
->core
, rate
);
2372 /* rollback the changes */
2373 clk
->min_rate
= old_min
;
2374 clk
->max_rate
= old_max
;
2378 if (clk
->exclusive_count
)
2379 clk_core_rate_protect(clk
->core
);
2381 clk_prepare_unlock();
2385 EXPORT_SYMBOL_GPL(clk_set_rate_range
);
2388 * clk_set_min_rate - set a minimum clock rate for a clock source
2389 * @clk: clock source
2390 * @rate: desired minimum clock rate in Hz, inclusive
2392 * Returns success (0) or negative errno.
2394 int clk_set_min_rate(struct clk
*clk
, unsigned long rate
)
2399 trace_clk_set_min_rate(clk
->core
, rate
);
2401 return clk_set_rate_range(clk
, rate
, clk
->max_rate
);
2403 EXPORT_SYMBOL_GPL(clk_set_min_rate
);
2406 * clk_set_max_rate - set a maximum clock rate for a clock source
2407 * @clk: clock source
2408 * @rate: desired maximum clock rate in Hz, inclusive
2410 * Returns success (0) or negative errno.
2412 int clk_set_max_rate(struct clk
*clk
, unsigned long rate
)
2417 trace_clk_set_max_rate(clk
->core
, rate
);
2419 return clk_set_rate_range(clk
, clk
->min_rate
, rate
);
2421 EXPORT_SYMBOL_GPL(clk_set_max_rate
);
2424 * clk_get_parent - return the parent of a clk
2425 * @clk: the clk whose parent gets returned
2427 * Simply returns clk->parent. Returns NULL if clk is NULL.
2429 struct clk
*clk_get_parent(struct clk
*clk
)
2437 /* TODO: Create a per-user clk and change callers to call clk_put */
2438 parent
= !clk
->core
->parent
? NULL
: clk
->core
->parent
->hw
->clk
;
2439 clk_prepare_unlock();
2443 EXPORT_SYMBOL_GPL(clk_get_parent
);
2445 static struct clk_core
*__clk_init_parent(struct clk_core
*core
)
2449 if (core
->num_parents
> 1 && core
->ops
->get_parent
)
2450 index
= core
->ops
->get_parent(core
->hw
);
2452 return clk_core_get_parent_by_index(core
, index
);
2455 static void clk_core_reparent(struct clk_core
*core
,
2456 struct clk_core
*new_parent
)
2458 clk_reparent(core
, new_parent
);
2459 __clk_recalc_accuracies(core
);
2460 __clk_recalc_rates(core
, POST_RATE_CHANGE
);
2463 void clk_hw_reparent(struct clk_hw
*hw
, struct clk_hw
*new_parent
)
2468 clk_core_reparent(hw
->core
, !new_parent
? NULL
: new_parent
->core
);
2472 * clk_has_parent - check if a clock is a possible parent for another
2473 * @clk: clock source
2474 * @parent: parent clock source
2476 * This function can be used in drivers that need to check that a clock can be
2477 * the parent of another without actually changing the parent.
2479 * Returns true if @parent is a possible parent for @clk, false otherwise.
2481 bool clk_has_parent(struct clk
*clk
, struct clk
*parent
)
2483 struct clk_core
*core
, *parent_core
;
2486 /* NULL clocks should be nops, so return success if either is NULL. */
2487 if (!clk
|| !parent
)
2491 parent_core
= parent
->core
;
2493 /* Optimize for the case where the parent is already the parent. */
2494 if (core
->parent
== parent_core
)
2497 for (i
= 0; i
< core
->num_parents
; i
++)
2498 if (!strcmp(core
->parents
[i
].name
, parent_core
->name
))
2503 EXPORT_SYMBOL_GPL(clk_has_parent
);
2505 static int clk_core_set_parent_nolock(struct clk_core
*core
,
2506 struct clk_core
*parent
)
2510 unsigned long p_rate
= 0;
2512 lockdep_assert_held(&prepare_lock
);
2517 if (core
->parent
== parent
)
2520 /* verify ops for multi-parent clks */
2521 if (core
->num_parents
> 1 && !core
->ops
->set_parent
)
2524 /* check that we are allowed to re-parent if the clock is in use */
2525 if ((core
->flags
& CLK_SET_PARENT_GATE
) && core
->prepare_count
)
2528 if (clk_core_rate_is_protected(core
))
2531 /* try finding the new parent index */
2533 p_index
= clk_fetch_parent_index(core
, parent
);
2535 pr_debug("%s: clk %s can not be parent of clk %s\n",
2536 __func__
, parent
->name
, core
->name
);
2539 p_rate
= parent
->rate
;
2542 ret
= clk_pm_runtime_get(core
);
2546 /* propagate PRE_RATE_CHANGE notifications */
2547 ret
= __clk_speculate_rates(core
, p_rate
);
2549 /* abort if a driver objects */
2550 if (ret
& NOTIFY_STOP_MASK
)
2553 /* do the re-parent */
2554 ret
= __clk_set_parent(core
, parent
, p_index
);
2556 /* propagate rate an accuracy recalculation accordingly */
2558 __clk_recalc_rates(core
, ABORT_RATE_CHANGE
);
2560 __clk_recalc_rates(core
, POST_RATE_CHANGE
);
2561 __clk_recalc_accuracies(core
);
2565 clk_pm_runtime_put(core
);
2570 int clk_hw_set_parent(struct clk_hw
*hw
, struct clk_hw
*parent
)
2572 return clk_core_set_parent_nolock(hw
->core
, parent
->core
);
2574 EXPORT_SYMBOL_GPL(clk_hw_set_parent
);
2577 * clk_set_parent - switch the parent of a mux clk
2578 * @clk: the mux clk whose input we are switching
2579 * @parent: the new input to clk
2581 * Re-parent clk to use parent as its new input source. If clk is in
2582 * prepared state, the clk will get enabled for the duration of this call. If
2583 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2584 * that, the reparenting is glitchy in hardware, etc), use the
2585 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2587 * After successfully changing clk's parent clk_set_parent will update the
2588 * clk topology, sysfs topology and propagate rate recalculation via
2589 * __clk_recalc_rates.
2591 * Returns 0 on success, -EERROR otherwise.
2593 int clk_set_parent(struct clk
*clk
, struct clk
*parent
)
2602 if (clk
->exclusive_count
)
2603 clk_core_rate_unprotect(clk
->core
);
2605 ret
= clk_core_set_parent_nolock(clk
->core
,
2606 parent
? parent
->core
: NULL
);
2608 if (clk
->exclusive_count
)
2609 clk_core_rate_protect(clk
->core
);
2611 clk_prepare_unlock();
2615 EXPORT_SYMBOL_GPL(clk_set_parent
);
2617 static int clk_core_set_phase_nolock(struct clk_core
*core
, int degrees
)
2621 lockdep_assert_held(&prepare_lock
);
2626 if (clk_core_rate_is_protected(core
))
2629 trace_clk_set_phase(core
, degrees
);
2631 if (core
->ops
->set_phase
) {
2632 ret
= core
->ops
->set_phase(core
->hw
, degrees
);
2634 core
->phase
= degrees
;
2637 trace_clk_set_phase_complete(core
, degrees
);
2643 * clk_set_phase - adjust the phase shift of a clock signal
2644 * @clk: clock signal source
2645 * @degrees: number of degrees the signal is shifted
2647 * Shifts the phase of a clock signal by the specified
2648 * degrees. Returns 0 on success, -EERROR otherwise.
2650 * This function makes no distinction about the input or reference
2651 * signal that we adjust the clock signal phase against. For example
2652 * phase locked-loop clock signal generators we may shift phase with
2653 * respect to feedback clock signal input, but for other cases the
2654 * clock phase may be shifted with respect to some other, unspecified
2657 * Additionally the concept of phase shift does not propagate through
2658 * the clock tree hierarchy, which sets it apart from clock rates and
2659 * clock accuracy. A parent clock phase attribute does not have an
2660 * impact on the phase attribute of a child clock.
2662 int clk_set_phase(struct clk
*clk
, int degrees
)
2669 /* sanity check degrees */
2676 if (clk
->exclusive_count
)
2677 clk_core_rate_unprotect(clk
->core
);
2679 ret
= clk_core_set_phase_nolock(clk
->core
, degrees
);
2681 if (clk
->exclusive_count
)
2682 clk_core_rate_protect(clk
->core
);
2684 clk_prepare_unlock();
2688 EXPORT_SYMBOL_GPL(clk_set_phase
);
2690 static int clk_core_get_phase(struct clk_core
*core
)
2694 lockdep_assert_held(&prepare_lock
);
2695 if (!core
->ops
->get_phase
)
2698 /* Always try to update cached phase if possible */
2699 ret
= core
->ops
->get_phase(core
->hw
);
2707 * clk_get_phase - return the phase shift of a clock signal
2708 * @clk: clock signal source
2710 * Returns the phase shift of a clock node in degrees, otherwise returns
2713 int clk_get_phase(struct clk
*clk
)
2721 ret
= clk_core_get_phase(clk
->core
);
2722 clk_prepare_unlock();
2726 EXPORT_SYMBOL_GPL(clk_get_phase
);
2728 static void clk_core_reset_duty_cycle_nolock(struct clk_core
*core
)
2730 /* Assume a default value of 50% */
2735 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core
*core
);
2737 static int clk_core_update_duty_cycle_nolock(struct clk_core
*core
)
2739 struct clk_duty
*duty
= &core
->duty
;
2742 if (!core
->ops
->get_duty_cycle
)
2743 return clk_core_update_duty_cycle_parent_nolock(core
);
2745 ret
= core
->ops
->get_duty_cycle(core
->hw
, duty
);
2749 /* Don't trust the clock provider too much */
2750 if (duty
->den
== 0 || duty
->num
> duty
->den
) {
2758 clk_core_reset_duty_cycle_nolock(core
);
2762 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core
*core
)
2767 core
->flags
& CLK_DUTY_CYCLE_PARENT
) {
2768 ret
= clk_core_update_duty_cycle_nolock(core
->parent
);
2769 memcpy(&core
->duty
, &core
->parent
->duty
, sizeof(core
->duty
));
2771 clk_core_reset_duty_cycle_nolock(core
);
2777 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core
*core
,
2778 struct clk_duty
*duty
);
2780 static int clk_core_set_duty_cycle_nolock(struct clk_core
*core
,
2781 struct clk_duty
*duty
)
2785 lockdep_assert_held(&prepare_lock
);
2787 if (clk_core_rate_is_protected(core
))
2790 trace_clk_set_duty_cycle(core
, duty
);
2792 if (!core
->ops
->set_duty_cycle
)
2793 return clk_core_set_duty_cycle_parent_nolock(core
, duty
);
2795 ret
= core
->ops
->set_duty_cycle(core
->hw
, duty
);
2797 memcpy(&core
->duty
, duty
, sizeof(*duty
));
2799 trace_clk_set_duty_cycle_complete(core
, duty
);
2804 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core
*core
,
2805 struct clk_duty
*duty
)
2810 core
->flags
& (CLK_DUTY_CYCLE_PARENT
| CLK_SET_RATE_PARENT
)) {
2811 ret
= clk_core_set_duty_cycle_nolock(core
->parent
, duty
);
2812 memcpy(&core
->duty
, &core
->parent
->duty
, sizeof(core
->duty
));
2819 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
2820 * @clk: clock signal source
2821 * @num: numerator of the duty cycle ratio to be applied
2822 * @den: denominator of the duty cycle ratio to be applied
2824 * Apply the duty cycle ratio if the ratio is valid and the clock can
2825 * perform this operation
2827 * Returns (0) on success, a negative errno otherwise.
2829 int clk_set_duty_cycle(struct clk
*clk
, unsigned int num
, unsigned int den
)
2832 struct clk_duty duty
;
2837 /* sanity check the ratio */
2838 if (den
== 0 || num
> den
)
2846 if (clk
->exclusive_count
)
2847 clk_core_rate_unprotect(clk
->core
);
2849 ret
= clk_core_set_duty_cycle_nolock(clk
->core
, &duty
);
2851 if (clk
->exclusive_count
)
2852 clk_core_rate_protect(clk
->core
);
2854 clk_prepare_unlock();
2858 EXPORT_SYMBOL_GPL(clk_set_duty_cycle
);
2860 static int clk_core_get_scaled_duty_cycle(struct clk_core
*core
,
2863 struct clk_duty
*duty
= &core
->duty
;
2868 ret
= clk_core_update_duty_cycle_nolock(core
);
2870 ret
= mult_frac(scale
, duty
->num
, duty
->den
);
2872 clk_prepare_unlock();
2878 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
2879 * @clk: clock signal source
2880 * @scale: scaling factor to be applied to represent the ratio as an integer
2882 * Returns the duty cycle ratio of a clock node multiplied by the provided
2883 * scaling factor, or negative errno on error.
2885 int clk_get_scaled_duty_cycle(struct clk
*clk
, unsigned int scale
)
2890 return clk_core_get_scaled_duty_cycle(clk
->core
, scale
);
2892 EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle
);
2895 * clk_is_match - check if two clk's point to the same hardware clock
2896 * @p: clk compared against q
2897 * @q: clk compared against p
2899 * Returns true if the two struct clk pointers both point to the same hardware
2900 * clock node. Put differently, returns true if struct clk *p and struct clk *q
2901 * share the same struct clk_core object.
2903 * Returns false otherwise. Note that two NULL clks are treated as matching.
2905 bool clk_is_match(const struct clk
*p
, const struct clk
*q
)
2907 /* trivial case: identical struct clk's or both NULL */
2911 /* true if clk->core pointers match. Avoid dereferencing garbage */
2912 if (!IS_ERR_OR_NULL(p
) && !IS_ERR_OR_NULL(q
))
2913 if (p
->core
== q
->core
)
2918 EXPORT_SYMBOL_GPL(clk_is_match
);
2920 /*** debugfs support ***/
2922 #ifdef CONFIG_DEBUG_FS
2923 #include <linux/debugfs.h>
2925 static struct dentry
*rootdir
;
2926 static int inited
= 0;
2927 static DEFINE_MUTEX(clk_debug_lock
);
2928 static HLIST_HEAD(clk_debug_list
);
2930 static struct hlist_head
*orphan_list
[] = {
2935 static void clk_summary_show_one(struct seq_file
*s
, struct clk_core
*c
,
2940 seq_printf(s
, "%*s%-*s %7d %8d %8d %11lu %10lu ",
2942 30 - level
* 3, c
->name
,
2943 c
->enable_count
, c
->prepare_count
, c
->protect_count
,
2944 clk_core_get_rate_recalc(c
),
2945 clk_core_get_accuracy_recalc(c
));
2947 phase
= clk_core_get_phase(c
);
2949 seq_printf(s
, "%5d", phase
);
2951 seq_puts(s
, "-----");
2953 seq_printf(s
, " %6d", clk_core_get_scaled_duty_cycle(c
, 100000));
2955 if (c
->ops
->is_enabled
)
2956 seq_printf(s
, " %9c\n", clk_core_is_enabled(c
) ? 'Y' : 'N');
2957 else if (!c
->ops
->enable
)
2958 seq_printf(s
, " %9c\n", 'Y');
2960 seq_printf(s
, " %9c\n", '?');
2963 static void clk_summary_show_subtree(struct seq_file
*s
, struct clk_core
*c
,
2966 struct clk_core
*child
;
2968 clk_summary_show_one(s
, c
, level
);
2970 hlist_for_each_entry(child
, &c
->children
, child_node
)
2971 clk_summary_show_subtree(s
, child
, level
+ 1);
2974 static int clk_summary_show(struct seq_file
*s
, void *data
)
2977 struct hlist_head
**lists
= (struct hlist_head
**)s
->private;
2979 seq_puts(s
, " enable prepare protect duty hardware\n");
2980 seq_puts(s
, " clock count count count rate accuracy phase cycle enable\n");
2981 seq_puts(s
, "-------------------------------------------------------------------------------------------------------\n");
2985 for (; *lists
; lists
++)
2986 hlist_for_each_entry(c
, *lists
, child_node
)
2987 clk_summary_show_subtree(s
, c
, 0);
2989 clk_prepare_unlock();
2993 DEFINE_SHOW_ATTRIBUTE(clk_summary
);
2995 static void clk_dump_one(struct seq_file
*s
, struct clk_core
*c
, int level
)
2998 unsigned long min_rate
, max_rate
;
3000 clk_core_get_boundaries(c
, &min_rate
, &max_rate
);
3002 /* This should be JSON format, i.e. elements separated with a comma */
3003 seq_printf(s
, "\"%s\": { ", c
->name
);
3004 seq_printf(s
, "\"enable_count\": %d,", c
->enable_count
);
3005 seq_printf(s
, "\"prepare_count\": %d,", c
->prepare_count
);
3006 seq_printf(s
, "\"protect_count\": %d,", c
->protect_count
);
3007 seq_printf(s
, "\"rate\": %lu,", clk_core_get_rate_recalc(c
));
3008 seq_printf(s
, "\"min_rate\": %lu,", min_rate
);
3009 seq_printf(s
, "\"max_rate\": %lu,", max_rate
);
3010 seq_printf(s
, "\"accuracy\": %lu,", clk_core_get_accuracy_recalc(c
));
3011 phase
= clk_core_get_phase(c
);
3013 seq_printf(s
, "\"phase\": %d,", phase
);
3014 seq_printf(s
, "\"duty_cycle\": %u",
3015 clk_core_get_scaled_duty_cycle(c
, 100000));
3018 static void clk_dump_subtree(struct seq_file
*s
, struct clk_core
*c
, int level
)
3020 struct clk_core
*child
;
3022 clk_dump_one(s
, c
, level
);
3024 hlist_for_each_entry(child
, &c
->children
, child_node
) {
3026 clk_dump_subtree(s
, child
, level
+ 1);
3032 static int clk_dump_show(struct seq_file
*s
, void *data
)
3035 bool first_node
= true;
3036 struct hlist_head
**lists
= (struct hlist_head
**)s
->private;
3041 for (; *lists
; lists
++) {
3042 hlist_for_each_entry(c
, *lists
, child_node
) {
3046 clk_dump_subtree(s
, c
, 0);
3050 clk_prepare_unlock();
3055 DEFINE_SHOW_ATTRIBUTE(clk_dump
);
3057 #undef CLOCK_ALLOW_WRITE_DEBUGFS
3058 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3060 * This can be dangerous, therefore don't provide any real compile time
3061 * configuration option for this feature.
3062 * People who want to use this will need to modify the source code directly.
3064 static int clk_rate_set(void *data
, u64 val
)
3066 struct clk_core
*core
= data
;
3070 ret
= clk_core_set_rate_nolock(core
, val
);
3071 clk_prepare_unlock();
3076 #define clk_rate_mode 0644
3078 static int clk_prepare_enable_set(void *data
, u64 val
)
3080 struct clk_core
*core
= data
;
3084 ret
= clk_prepare_enable(core
->hw
->clk
);
3086 clk_disable_unprepare(core
->hw
->clk
);
3091 static int clk_prepare_enable_get(void *data
, u64
*val
)
3093 struct clk_core
*core
= data
;
3095 *val
= core
->enable_count
&& core
->prepare_count
;
3099 DEFINE_DEBUGFS_ATTRIBUTE(clk_prepare_enable_fops
, clk_prepare_enable_get
,
3100 clk_prepare_enable_set
, "%llu\n");
3103 #define clk_rate_set NULL
3104 #define clk_rate_mode 0444
3107 static int clk_rate_get(void *data
, u64
*val
)
3109 struct clk_core
*core
= data
;
3115 DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops
, clk_rate_get
, clk_rate_set
, "%llu\n");
3117 static const struct {
3121 #define ENTRY(f) { f, #f }
3122 ENTRY(CLK_SET_RATE_GATE
),
3123 ENTRY(CLK_SET_PARENT_GATE
),
3124 ENTRY(CLK_SET_RATE_PARENT
),
3125 ENTRY(CLK_IGNORE_UNUSED
),
3126 ENTRY(CLK_GET_RATE_NOCACHE
),
3127 ENTRY(CLK_SET_RATE_NO_REPARENT
),
3128 ENTRY(CLK_GET_ACCURACY_NOCACHE
),
3129 ENTRY(CLK_RECALC_NEW_RATES
),
3130 ENTRY(CLK_SET_RATE_UNGATE
),
3131 ENTRY(CLK_IS_CRITICAL
),
3132 ENTRY(CLK_OPS_PARENT_ENABLE
),
3133 ENTRY(CLK_DUTY_CYCLE_PARENT
),
3137 static int clk_flags_show(struct seq_file
*s
, void *data
)
3139 struct clk_core
*core
= s
->private;
3140 unsigned long flags
= core
->flags
;
3143 for (i
= 0; flags
&& i
< ARRAY_SIZE(clk_flags
); i
++) {
3144 if (flags
& clk_flags
[i
].flag
) {
3145 seq_printf(s
, "%s\n", clk_flags
[i
].name
);
3146 flags
&= ~clk_flags
[i
].flag
;
3151 seq_printf(s
, "0x%lx\n", flags
);
3156 DEFINE_SHOW_ATTRIBUTE(clk_flags
);
3158 static void possible_parent_show(struct seq_file
*s
, struct clk_core
*core
,
3159 unsigned int i
, char terminator
)
3161 struct clk_core
*parent
;
3164 * Go through the following options to fetch a parent's name.
3166 * 1. Fetch the registered parent clock and use its name
3167 * 2. Use the global (fallback) name if specified
3168 * 3. Use the local fw_name if provided
3169 * 4. Fetch parent clock's clock-output-name if DT index was set
3171 * This may still fail in some cases, such as when the parent is
3172 * specified directly via a struct clk_hw pointer, but it isn't
3175 parent
= clk_core_get_parent_by_index(core
, i
);
3177 seq_puts(s
, parent
->name
);
3178 else if (core
->parents
[i
].name
)
3179 seq_puts(s
, core
->parents
[i
].name
);
3180 else if (core
->parents
[i
].fw_name
)
3181 seq_printf(s
, "<%s>(fw)", core
->parents
[i
].fw_name
);
3182 else if (core
->parents
[i
].index
>= 0)
3184 of_clk_get_parent_name(core
->of_node
,
3185 core
->parents
[i
].index
));
3187 seq_puts(s
, "(missing)");
3189 seq_putc(s
, terminator
);
3192 static int possible_parents_show(struct seq_file
*s
, void *data
)
3194 struct clk_core
*core
= s
->private;
3197 for (i
= 0; i
< core
->num_parents
- 1; i
++)
3198 possible_parent_show(s
, core
, i
, ' ');
3200 possible_parent_show(s
, core
, i
, '\n');
3204 DEFINE_SHOW_ATTRIBUTE(possible_parents
);
3206 static int current_parent_show(struct seq_file
*s
, void *data
)
3208 struct clk_core
*core
= s
->private;
3211 seq_printf(s
, "%s\n", core
->parent
->name
);
3215 DEFINE_SHOW_ATTRIBUTE(current_parent
);
3217 static int clk_duty_cycle_show(struct seq_file
*s
, void *data
)
3219 struct clk_core
*core
= s
->private;
3220 struct clk_duty
*duty
= &core
->duty
;
3222 seq_printf(s
, "%u/%u\n", duty
->num
, duty
->den
);
3226 DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle
);
3228 static int clk_min_rate_show(struct seq_file
*s
, void *data
)
3230 struct clk_core
*core
= s
->private;
3231 unsigned long min_rate
, max_rate
;
3234 clk_core_get_boundaries(core
, &min_rate
, &max_rate
);
3235 clk_prepare_unlock();
3236 seq_printf(s
, "%lu\n", min_rate
);
3240 DEFINE_SHOW_ATTRIBUTE(clk_min_rate
);
3242 static int clk_max_rate_show(struct seq_file
*s
, void *data
)
3244 struct clk_core
*core
= s
->private;
3245 unsigned long min_rate
, max_rate
;
3248 clk_core_get_boundaries(core
, &min_rate
, &max_rate
);
3249 clk_prepare_unlock();
3250 seq_printf(s
, "%lu\n", max_rate
);
3254 DEFINE_SHOW_ATTRIBUTE(clk_max_rate
);
3256 static void clk_debug_create_one(struct clk_core
*core
, struct dentry
*pdentry
)
3258 struct dentry
*root
;
3260 if (!core
|| !pdentry
)
3263 root
= debugfs_create_dir(core
->name
, pdentry
);
3264 core
->dentry
= root
;
3266 debugfs_create_file("clk_rate", clk_rate_mode
, root
, core
,
3268 debugfs_create_file("clk_min_rate", 0444, root
, core
, &clk_min_rate_fops
);
3269 debugfs_create_file("clk_max_rate", 0444, root
, core
, &clk_max_rate_fops
);
3270 debugfs_create_ulong("clk_accuracy", 0444, root
, &core
->accuracy
);
3271 debugfs_create_u32("clk_phase", 0444, root
, &core
->phase
);
3272 debugfs_create_file("clk_flags", 0444, root
, core
, &clk_flags_fops
);
3273 debugfs_create_u32("clk_prepare_count", 0444, root
, &core
->prepare_count
);
3274 debugfs_create_u32("clk_enable_count", 0444, root
, &core
->enable_count
);
3275 debugfs_create_u32("clk_protect_count", 0444, root
, &core
->protect_count
);
3276 debugfs_create_u32("clk_notifier_count", 0444, root
, &core
->notifier_count
);
3277 debugfs_create_file("clk_duty_cycle", 0444, root
, core
,
3278 &clk_duty_cycle_fops
);
3279 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3280 debugfs_create_file("clk_prepare_enable", 0644, root
, core
,
3281 &clk_prepare_enable_fops
);
3284 if (core
->num_parents
> 0)
3285 debugfs_create_file("clk_parent", 0444, root
, core
,
3286 ¤t_parent_fops
);
3288 if (core
->num_parents
> 1)
3289 debugfs_create_file("clk_possible_parents", 0444, root
, core
,
3290 &possible_parents_fops
);
3292 if (core
->ops
->debug_init
)
3293 core
->ops
->debug_init(core
->hw
, core
->dentry
);
3297 * clk_debug_register - add a clk node to the debugfs clk directory
3298 * @core: the clk being added to the debugfs clk directory
3300 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
3301 * initialized. Otherwise it bails out early since the debugfs clk directory
3302 * will be created lazily by clk_debug_init as part of a late_initcall.
3304 static void clk_debug_register(struct clk_core
*core
)
3306 mutex_lock(&clk_debug_lock
);
3307 hlist_add_head(&core
->debug_node
, &clk_debug_list
);
3309 clk_debug_create_one(core
, rootdir
);
3310 mutex_unlock(&clk_debug_lock
);
3314 * clk_debug_unregister - remove a clk node from the debugfs clk directory
3315 * @core: the clk being removed from the debugfs clk directory
3317 * Dynamically removes a clk and all its child nodes from the
3318 * debugfs clk directory if clk->dentry points to debugfs created by
3319 * clk_debug_register in __clk_core_init.
3321 static void clk_debug_unregister(struct clk_core
*core
)
3323 mutex_lock(&clk_debug_lock
);
3324 hlist_del_init(&core
->debug_node
);
3325 debugfs_remove_recursive(core
->dentry
);
3326 core
->dentry
= NULL
;
3327 mutex_unlock(&clk_debug_lock
);
3331 * clk_debug_init - lazily populate the debugfs clk directory
3333 * clks are often initialized very early during boot before memory can be
3334 * dynamically allocated and well before debugfs is setup. This function
3335 * populates the debugfs clk directory once at boot-time when we know that
3336 * debugfs is setup. It should only be called once at boot-time, all other clks
3337 * added dynamically will be done so with clk_debug_register.
3339 static int __init
clk_debug_init(void)
3341 struct clk_core
*core
;
3343 rootdir
= debugfs_create_dir("clk", NULL
);
3345 debugfs_create_file("clk_summary", 0444, rootdir
, &all_lists
,
3347 debugfs_create_file("clk_dump", 0444, rootdir
, &all_lists
,
3349 debugfs_create_file("clk_orphan_summary", 0444, rootdir
, &orphan_list
,
3351 debugfs_create_file("clk_orphan_dump", 0444, rootdir
, &orphan_list
,
3354 mutex_lock(&clk_debug_lock
);
3355 hlist_for_each_entry(core
, &clk_debug_list
, debug_node
)
3356 clk_debug_create_one(core
, rootdir
);
3359 mutex_unlock(&clk_debug_lock
);
3363 late_initcall(clk_debug_init
);
3365 static inline void clk_debug_register(struct clk_core
*core
) { }
3366 static inline void clk_debug_unregister(struct clk_core
*core
)
3371 static void clk_core_reparent_orphans_nolock(void)
3373 struct clk_core
*orphan
;
3374 struct hlist_node
*tmp2
;
3377 * walk the list of orphan clocks and reparent any that newly finds a
3380 hlist_for_each_entry_safe(orphan
, tmp2
, &clk_orphan_list
, child_node
) {
3381 struct clk_core
*parent
= __clk_init_parent(orphan
);
3384 * We need to use __clk_set_parent_before() and _after() to
3385 * to properly migrate any prepare/enable count of the orphan
3386 * clock. This is important for CLK_IS_CRITICAL clocks, which
3387 * are enabled during init but might not have a parent yet.
3390 /* update the clk tree topology */
3391 __clk_set_parent_before(orphan
, parent
);
3392 __clk_set_parent_after(orphan
, parent
, NULL
);
3393 __clk_recalc_accuracies(orphan
);
3394 __clk_recalc_rates(orphan
, 0);
3400 * __clk_core_init - initialize the data structures in a struct clk_core
3401 * @core: clk_core being initialized
3403 * Initializes the lists in struct clk_core, queries the hardware for the
3404 * parent and rate and sets them both.
3406 static int __clk_core_init(struct clk_core
*core
)
3409 struct clk_core
*parent
;
3418 ret
= clk_pm_runtime_get(core
);
3422 /* check to see if a clock with this name is already registered */
3423 if (clk_core_lookup(core
->name
)) {
3424 pr_debug("%s: clk %s already initialized\n",
3425 __func__
, core
->name
);
3430 /* check that clk_ops are sane. See Documentation/driver-api/clk.rst */
3431 if (core
->ops
->set_rate
&&
3432 !((core
->ops
->round_rate
|| core
->ops
->determine_rate
) &&
3433 core
->ops
->recalc_rate
)) {
3434 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
3435 __func__
, core
->name
);
3440 if (core
->ops
->set_parent
&& !core
->ops
->get_parent
) {
3441 pr_err("%s: %s must implement .get_parent & .set_parent\n",
3442 __func__
, core
->name
);
3447 if (core
->num_parents
> 1 && !core
->ops
->get_parent
) {
3448 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
3449 __func__
, core
->name
);
3454 if (core
->ops
->set_rate_and_parent
&&
3455 !(core
->ops
->set_parent
&& core
->ops
->set_rate
)) {
3456 pr_err("%s: %s must implement .set_parent & .set_rate\n",
3457 __func__
, core
->name
);
3463 * optional platform-specific magic
3465 * The .init callback is not used by any of the basic clock types, but
3466 * exists for weird hardware that must perform initialization magic for
3467 * CCF to get an accurate view of clock for any other callbacks. It may
3468 * also be used needs to perform dynamic allocations. Such allocation
3469 * must be freed in the terminate() callback.
3470 * This callback shall not be used to initialize the parameters state,
3471 * such as rate, parent, etc ...
3473 * If it exist, this callback should called before any other callback of
3476 if (core
->ops
->init
) {
3477 ret
= core
->ops
->init(core
->hw
);
3482 parent
= core
->parent
= __clk_init_parent(core
);
3485 * Populate core->parent if parent has already been clk_core_init'd. If
3486 * parent has not yet been clk_core_init'd then place clk in the orphan
3487 * list. If clk doesn't have any parents then place it in the root
3490 * Every time a new clk is clk_init'd then we walk the list of orphan
3491 * clocks and re-parent any that are children of the clock currently
3495 hlist_add_head(&core
->child_node
, &parent
->children
);
3496 core
->orphan
= parent
->orphan
;
3497 } else if (!core
->num_parents
) {
3498 hlist_add_head(&core
->child_node
, &clk_root_list
);
3499 core
->orphan
= false;
3501 hlist_add_head(&core
->child_node
, &clk_orphan_list
);
3502 core
->orphan
= true;
3506 * Set clk's accuracy. The preferred method is to use
3507 * .recalc_accuracy. For simple clocks and lazy developers the default
3508 * fallback is to use the parent's accuracy. If a clock doesn't have a
3509 * parent (or is orphaned) then accuracy is set to zero (perfect
3512 if (core
->ops
->recalc_accuracy
)
3513 core
->accuracy
= core
->ops
->recalc_accuracy(core
->hw
,
3514 clk_core_get_accuracy_no_lock(parent
));
3516 core
->accuracy
= parent
->accuracy
;
3521 * Set clk's phase by clk_core_get_phase() caching the phase.
3522 * Since a phase is by definition relative to its parent, just
3523 * query the current clock phase, or just assume it's in phase.
3525 phase
= clk_core_get_phase(core
);
3528 pr_warn("%s: Failed to get phase for clk '%s'\n", __func__
,
3534 * Set clk's duty cycle.
3536 clk_core_update_duty_cycle_nolock(core
);
3539 * Set clk's rate. The preferred method is to use .recalc_rate. For
3540 * simple clocks and lazy developers the default fallback is to use the
3541 * parent's rate. If a clock doesn't have a parent (or is orphaned)
3542 * then rate is set to zero.
3544 if (core
->ops
->recalc_rate
)
3545 rate
= core
->ops
->recalc_rate(core
->hw
,
3546 clk_core_get_rate_nolock(parent
));
3548 rate
= parent
->rate
;
3551 core
->rate
= core
->req_rate
= rate
;
3554 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
3555 * don't get accidentally disabled when walking the orphan tree and
3556 * reparenting clocks
3558 if (core
->flags
& CLK_IS_CRITICAL
) {
3559 ret
= clk_core_prepare(core
);
3561 pr_warn("%s: critical clk '%s' failed to prepare\n",
3562 __func__
, core
->name
);
3566 ret
= clk_core_enable_lock(core
);
3568 pr_warn("%s: critical clk '%s' failed to enable\n",
3569 __func__
, core
->name
);
3570 clk_core_unprepare(core
);
3575 clk_core_reparent_orphans_nolock();
3578 kref_init(&core
->ref
);
3580 clk_pm_runtime_put(core
);
3583 hlist_del_init(&core
->child_node
);
3585 clk_prepare_unlock();
3588 clk_debug_register(core
);
3594 * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core
3595 * @core: clk to add consumer to
3596 * @clk: consumer to link to a clk
3598 static void clk_core_link_consumer(struct clk_core
*core
, struct clk
*clk
)
3601 hlist_add_head(&clk
->clks_node
, &core
->clks
);
3602 clk_prepare_unlock();
3606 * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core
3607 * @clk: consumer to unlink
3609 static void clk_core_unlink_consumer(struct clk
*clk
)
3611 lockdep_assert_held(&prepare_lock
);
3612 hlist_del(&clk
->clks_node
);
3616 * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core
3617 * @core: clk to allocate a consumer for
3618 * @dev_id: string describing device name
3619 * @con_id: connection ID string on device
3621 * Returns: clk consumer left unlinked from the consumer list
3623 static struct clk
*alloc_clk(struct clk_core
*core
, const char *dev_id
,
3628 clk
= kzalloc(sizeof(*clk
), GFP_KERNEL
);
3630 return ERR_PTR(-ENOMEM
);
3633 clk
->dev_id
= dev_id
;
3634 clk
->con_id
= kstrdup_const(con_id
, GFP_KERNEL
);
3635 clk
->max_rate
= ULONG_MAX
;
3641 * free_clk - Free a clk consumer
3642 * @clk: clk consumer to free
3644 * Note, this assumes the clk has been unlinked from the clk_core consumer
3647 static void free_clk(struct clk
*clk
)
3649 kfree_const(clk
->con_id
);
3654 * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given
3656 * @dev: clk consumer device
3657 * @hw: clk_hw associated with the clk being consumed
3658 * @dev_id: string describing device name
3659 * @con_id: connection ID string on device
3661 * This is the main function used to create a clk pointer for use by clk
3662 * consumers. It connects a consumer to the clk_core and clk_hw structures
3663 * used by the framework and clk provider respectively.
3665 struct clk
*clk_hw_create_clk(struct device
*dev
, struct clk_hw
*hw
,
3666 const char *dev_id
, const char *con_id
)
3669 struct clk_core
*core
;
3671 /* This is to allow this function to be chained to others */
3672 if (IS_ERR_OR_NULL(hw
))
3673 return ERR_CAST(hw
);
3676 clk
= alloc_clk(core
, dev_id
, con_id
);
3681 if (!try_module_get(core
->owner
)) {
3683 return ERR_PTR(-ENOENT
);
3686 kref_get(&core
->ref
);
3687 clk_core_link_consumer(core
, clk
);
3693 * clk_hw_get_clk - get clk consumer given an clk_hw
3694 * @hw: clk_hw associated with the clk being consumed
3695 * @con_id: connection ID string on device
3697 * Returns: new clk consumer
3698 * This is the function to be used by providers which need
3699 * to get a consumer clk and act on the clock element
3700 * Calls to this function must be balanced with calls clk_put()
3702 struct clk
*clk_hw_get_clk(struct clk_hw
*hw
, const char *con_id
)
3704 struct device
*dev
= hw
->core
->dev
;
3706 return clk_hw_create_clk(dev
, hw
, dev_name(dev
), con_id
);
3708 EXPORT_SYMBOL(clk_hw_get_clk
);
3710 static int clk_cpy_name(const char **dst_p
, const char *src
, bool must_exist
)
3720 *dst_p
= dst
= kstrdup_const(src
, GFP_KERNEL
);
3727 static int clk_core_populate_parent_map(struct clk_core
*core
,
3728 const struct clk_init_data
*init
)
3730 u8 num_parents
= init
->num_parents
;
3731 const char * const *parent_names
= init
->parent_names
;
3732 const struct clk_hw
**parent_hws
= init
->parent_hws
;
3733 const struct clk_parent_data
*parent_data
= init
->parent_data
;
3735 struct clk_parent_map
*parents
, *parent
;
3741 * Avoid unnecessary string look-ups of clk_core's possible parents by
3742 * having a cache of names/clk_hw pointers to clk_core pointers.
3744 parents
= kcalloc(num_parents
, sizeof(*parents
), GFP_KERNEL
);
3745 core
->parents
= parents
;
3749 /* Copy everything over because it might be __initdata */
3750 for (i
= 0, parent
= parents
; i
< num_parents
; i
++, parent
++) {
3753 /* throw a WARN if any entries are NULL */
3754 WARN(!parent_names
[i
],
3755 "%s: invalid NULL in %s's .parent_names\n",
3756 __func__
, core
->name
);
3757 ret
= clk_cpy_name(&parent
->name
, parent_names
[i
],
3759 } else if (parent_data
) {
3760 parent
->hw
= parent_data
[i
].hw
;
3761 parent
->index
= parent_data
[i
].index
;
3762 ret
= clk_cpy_name(&parent
->fw_name
,
3763 parent_data
[i
].fw_name
, false);
3765 ret
= clk_cpy_name(&parent
->name
,
3766 parent_data
[i
].name
,
3768 } else if (parent_hws
) {
3769 parent
->hw
= parent_hws
[i
];
3772 WARN(1, "Must specify parents if num_parents > 0\n");
3777 kfree_const(parents
[i
].name
);
3778 kfree_const(parents
[i
].fw_name
);
3789 static void clk_core_free_parent_map(struct clk_core
*core
)
3791 int i
= core
->num_parents
;
3793 if (!core
->num_parents
)
3797 kfree_const(core
->parents
[i
].name
);
3798 kfree_const(core
->parents
[i
].fw_name
);
3801 kfree(core
->parents
);
3805 __clk_register(struct device
*dev
, struct device_node
*np
, struct clk_hw
*hw
)
3808 struct clk_core
*core
;
3809 const struct clk_init_data
*init
= hw
->init
;
3812 * The init data is not supposed to be used outside of registration path.
3813 * Set it to NULL so that provider drivers can't use it either and so that
3814 * we catch use of hw->init early on in the core.
3818 core
= kzalloc(sizeof(*core
), GFP_KERNEL
);
3824 core
->name
= kstrdup_const(init
->name
, GFP_KERNEL
);
3830 if (WARN_ON(!init
->ops
)) {
3834 core
->ops
= init
->ops
;
3836 if (dev
&& pm_runtime_enabled(dev
))
3837 core
->rpm_enabled
= true;
3840 if (dev
&& dev
->driver
)
3841 core
->owner
= dev
->driver
->owner
;
3843 core
->flags
= init
->flags
;
3844 core
->num_parents
= init
->num_parents
;
3846 core
->max_rate
= ULONG_MAX
;
3849 ret
= clk_core_populate_parent_map(core
, init
);
3853 INIT_HLIST_HEAD(&core
->clks
);
3856 * Don't call clk_hw_create_clk() here because that would pin the
3857 * provider module to itself and prevent it from ever being removed.
3859 hw
->clk
= alloc_clk(core
, NULL
, NULL
);
3860 if (IS_ERR(hw
->clk
)) {
3861 ret
= PTR_ERR(hw
->clk
);
3862 goto fail_create_clk
;
3865 clk_core_link_consumer(hw
->core
, hw
->clk
);
3867 ret
= __clk_core_init(core
);
3872 clk_core_unlink_consumer(hw
->clk
);
3873 clk_prepare_unlock();
3879 clk_core_free_parent_map(core
);
3882 kfree_const(core
->name
);
3886 return ERR_PTR(ret
);
3890 * dev_or_parent_of_node() - Get device node of @dev or @dev's parent
3891 * @dev: Device to get device node of
3893 * Return: device node pointer of @dev, or the device node pointer of
3894 * @dev->parent if dev doesn't have a device node, or NULL if neither
3895 * @dev or @dev->parent have a device node.
3897 static struct device_node
*dev_or_parent_of_node(struct device
*dev
)
3899 struct device_node
*np
;
3904 np
= dev_of_node(dev
);
3906 np
= dev_of_node(dev
->parent
);
3912 * clk_register - allocate a new clock, register it and return an opaque cookie
3913 * @dev: device that is registering this clock
3914 * @hw: link to hardware-specific clock data
3916 * clk_register is the *deprecated* interface for populating the clock tree with
3917 * new clock nodes. Use clk_hw_register() instead.
3919 * Returns: a pointer to the newly allocated struct clk which
3920 * cannot be dereferenced by driver code but may be used in conjunction with the
3921 * rest of the clock API. In the event of an error clk_register will return an
3922 * error code; drivers must test for an error code after calling clk_register.
3924 struct clk
*clk_register(struct device
*dev
, struct clk_hw
*hw
)
3926 return __clk_register(dev
, dev_or_parent_of_node(dev
), hw
);
3928 EXPORT_SYMBOL_GPL(clk_register
);
3931 * clk_hw_register - register a clk_hw and return an error code
3932 * @dev: device that is registering this clock
3933 * @hw: link to hardware-specific clock data
3935 * clk_hw_register is the primary interface for populating the clock tree with
3936 * new clock nodes. It returns an integer equal to zero indicating success or
3937 * less than zero indicating failure. Drivers must test for an error code after
3938 * calling clk_hw_register().
3940 int clk_hw_register(struct device
*dev
, struct clk_hw
*hw
)
3942 return PTR_ERR_OR_ZERO(__clk_register(dev
, dev_or_parent_of_node(dev
),
3945 EXPORT_SYMBOL_GPL(clk_hw_register
);
3948 * of_clk_hw_register - register a clk_hw and return an error code
3949 * @node: device_node of device that is registering this clock
3950 * @hw: link to hardware-specific clock data
3952 * of_clk_hw_register() is the primary interface for populating the clock tree
3953 * with new clock nodes when a struct device is not available, but a struct
3954 * device_node is. It returns an integer equal to zero indicating success or
3955 * less than zero indicating failure. Drivers must test for an error code after
3956 * calling of_clk_hw_register().
3958 int of_clk_hw_register(struct device_node
*node
, struct clk_hw
*hw
)
3960 return PTR_ERR_OR_ZERO(__clk_register(NULL
, node
, hw
));
3962 EXPORT_SYMBOL_GPL(of_clk_hw_register
);
3964 /* Free memory allocated for a clock. */
3965 static void __clk_release(struct kref
*ref
)
3967 struct clk_core
*core
= container_of(ref
, struct clk_core
, ref
);
3969 lockdep_assert_held(&prepare_lock
);
3971 clk_core_free_parent_map(core
);
3972 kfree_const(core
->name
);
3977 * Empty clk_ops for unregistered clocks. These are used temporarily
3978 * after clk_unregister() was called on a clock and until last clock
3979 * consumer calls clk_put() and the struct clk object is freed.
3981 static int clk_nodrv_prepare_enable(struct clk_hw
*hw
)
3986 static void clk_nodrv_disable_unprepare(struct clk_hw
*hw
)
3991 static int clk_nodrv_set_rate(struct clk_hw
*hw
, unsigned long rate
,
3992 unsigned long parent_rate
)
3997 static int clk_nodrv_set_parent(struct clk_hw
*hw
, u8 index
)
4002 static const struct clk_ops clk_nodrv_ops
= {
4003 .enable
= clk_nodrv_prepare_enable
,
4004 .disable
= clk_nodrv_disable_unprepare
,
4005 .prepare
= clk_nodrv_prepare_enable
,
4006 .unprepare
= clk_nodrv_disable_unprepare
,
4007 .set_rate
= clk_nodrv_set_rate
,
4008 .set_parent
= clk_nodrv_set_parent
,
4011 static void clk_core_evict_parent_cache_subtree(struct clk_core
*root
,
4012 struct clk_core
*target
)
4015 struct clk_core
*child
;
4017 for (i
= 0; i
< root
->num_parents
; i
++)
4018 if (root
->parents
[i
].core
== target
)
4019 root
->parents
[i
].core
= NULL
;
4021 hlist_for_each_entry(child
, &root
->children
, child_node
)
4022 clk_core_evict_parent_cache_subtree(child
, target
);
4025 /* Remove this clk from all parent caches */
4026 static void clk_core_evict_parent_cache(struct clk_core
*core
)
4028 struct hlist_head
**lists
;
4029 struct clk_core
*root
;
4031 lockdep_assert_held(&prepare_lock
);
4033 for (lists
= all_lists
; *lists
; lists
++)
4034 hlist_for_each_entry(root
, *lists
, child_node
)
4035 clk_core_evict_parent_cache_subtree(root
, core
);
4040 * clk_unregister - unregister a currently registered clock
4041 * @clk: clock to unregister
4043 void clk_unregister(struct clk
*clk
)
4045 unsigned long flags
;
4046 const struct clk_ops
*ops
;
4048 if (!clk
|| WARN_ON_ONCE(IS_ERR(clk
)))
4051 clk_debug_unregister(clk
->core
);
4055 ops
= clk
->core
->ops
;
4056 if (ops
== &clk_nodrv_ops
) {
4057 pr_err("%s: unregistered clock: %s\n", __func__
,
4062 * Assign empty clock ops for consumers that might still hold
4063 * a reference to this clock.
4065 flags
= clk_enable_lock();
4066 clk
->core
->ops
= &clk_nodrv_ops
;
4067 clk_enable_unlock(flags
);
4070 ops
->terminate(clk
->core
->hw
);
4072 if (!hlist_empty(&clk
->core
->children
)) {
4073 struct clk_core
*child
;
4074 struct hlist_node
*t
;
4076 /* Reparent all children to the orphan list. */
4077 hlist_for_each_entry_safe(child
, t
, &clk
->core
->children
,
4079 clk_core_set_parent_nolock(child
, NULL
);
4082 clk_core_evict_parent_cache(clk
->core
);
4084 hlist_del_init(&clk
->core
->child_node
);
4086 if (clk
->core
->prepare_count
)
4087 pr_warn("%s: unregistering prepared clock: %s\n",
4088 __func__
, clk
->core
->name
);
4090 if (clk
->core
->protect_count
)
4091 pr_warn("%s: unregistering protected clock: %s\n",
4092 __func__
, clk
->core
->name
);
4094 kref_put(&clk
->core
->ref
, __clk_release
);
4097 clk_prepare_unlock();
4099 EXPORT_SYMBOL_GPL(clk_unregister
);
4102 * clk_hw_unregister - unregister a currently registered clk_hw
4103 * @hw: hardware-specific clock data to unregister
4105 void clk_hw_unregister(struct clk_hw
*hw
)
4107 clk_unregister(hw
->clk
);
4109 EXPORT_SYMBOL_GPL(clk_hw_unregister
);
4111 static void devm_clk_unregister_cb(struct device
*dev
, void *res
)
4113 clk_unregister(*(struct clk
**)res
);
4116 static void devm_clk_hw_unregister_cb(struct device
*dev
, void *res
)
4118 clk_hw_unregister(*(struct clk_hw
**)res
);
4122 * devm_clk_register - resource managed clk_register()
4123 * @dev: device that is registering this clock
4124 * @hw: link to hardware-specific clock data
4126 * Managed clk_register(). This function is *deprecated*, use devm_clk_hw_register() instead.
4128 * Clocks returned from this function are automatically clk_unregister()ed on
4129 * driver detach. See clk_register() for more information.
4131 struct clk
*devm_clk_register(struct device
*dev
, struct clk_hw
*hw
)
4136 clkp
= devres_alloc(devm_clk_unregister_cb
, sizeof(*clkp
), GFP_KERNEL
);
4138 return ERR_PTR(-ENOMEM
);
4140 clk
= clk_register(dev
, hw
);
4143 devres_add(dev
, clkp
);
4150 EXPORT_SYMBOL_GPL(devm_clk_register
);
4153 * devm_clk_hw_register - resource managed clk_hw_register()
4154 * @dev: device that is registering this clock
4155 * @hw: link to hardware-specific clock data
4157 * Managed clk_hw_register(). Clocks registered by this function are
4158 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
4159 * for more information.
4161 int devm_clk_hw_register(struct device
*dev
, struct clk_hw
*hw
)
4163 struct clk_hw
**hwp
;
4166 hwp
= devres_alloc(devm_clk_hw_unregister_cb
, sizeof(*hwp
), GFP_KERNEL
);
4170 ret
= clk_hw_register(dev
, hw
);
4173 devres_add(dev
, hwp
);
4180 EXPORT_SYMBOL_GPL(devm_clk_hw_register
);
4182 static int devm_clk_match(struct device
*dev
, void *res
, void *data
)
4184 struct clk
*c
= res
;
4190 static int devm_clk_hw_match(struct device
*dev
, void *res
, void *data
)
4192 struct clk_hw
*hw
= res
;
4200 * devm_clk_unregister - resource managed clk_unregister()
4201 * @dev: device that is unregistering the clock data
4202 * @clk: clock to unregister
4204 * Deallocate a clock allocated with devm_clk_register(). Normally
4205 * this function will not need to be called and the resource management
4206 * code will ensure that the resource is freed.
4208 void devm_clk_unregister(struct device
*dev
, struct clk
*clk
)
4210 WARN_ON(devres_release(dev
, devm_clk_unregister_cb
, devm_clk_match
, clk
));
4212 EXPORT_SYMBOL_GPL(devm_clk_unregister
);
4215 * devm_clk_hw_unregister - resource managed clk_hw_unregister()
4216 * @dev: device that is unregistering the hardware-specific clock data
4217 * @hw: link to hardware-specific clock data
4219 * Unregister a clk_hw registered with devm_clk_hw_register(). Normally
4220 * this function will not need to be called and the resource management
4221 * code will ensure that the resource is freed.
4223 void devm_clk_hw_unregister(struct device
*dev
, struct clk_hw
*hw
)
4225 WARN_ON(devres_release(dev
, devm_clk_hw_unregister_cb
, devm_clk_hw_match
,
4228 EXPORT_SYMBOL_GPL(devm_clk_hw_unregister
);
4230 static void devm_clk_release(struct device
*dev
, void *res
)
4232 clk_put(*(struct clk
**)res
);
4236 * devm_clk_hw_get_clk - resource managed clk_hw_get_clk()
4237 * @dev: device that is registering this clock
4238 * @hw: clk_hw associated with the clk being consumed
4239 * @con_id: connection ID string on device
4241 * Managed clk_hw_get_clk(). Clocks got with this function are
4242 * automatically clk_put() on driver detach. See clk_put()
4243 * for more information.
4245 struct clk
*devm_clk_hw_get_clk(struct device
*dev
, struct clk_hw
*hw
,
4251 /* This should not happen because it would mean we have drivers
4252 * passing around clk_hw pointers instead of having the caller use
4253 * proper clk_get() style APIs
4255 WARN_ON_ONCE(dev
!= hw
->core
->dev
);
4257 clkp
= devres_alloc(devm_clk_release
, sizeof(*clkp
), GFP_KERNEL
);
4259 return ERR_PTR(-ENOMEM
);
4261 clk
= clk_hw_get_clk(hw
, con_id
);
4264 devres_add(dev
, clkp
);
4271 EXPORT_SYMBOL_GPL(devm_clk_hw_get_clk
);
4277 void __clk_put(struct clk
*clk
)
4279 struct module
*owner
;
4281 if (!clk
|| WARN_ON_ONCE(IS_ERR(clk
)))
4287 * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
4288 * given user should be balanced with calls to clk_rate_exclusive_put()
4289 * and by that same consumer
4291 if (WARN_ON(clk
->exclusive_count
)) {
4292 /* We voiced our concern, let's sanitize the situation */
4293 clk
->core
->protect_count
-= (clk
->exclusive_count
- 1);
4294 clk_core_rate_unprotect(clk
->core
);
4295 clk
->exclusive_count
= 0;
4298 hlist_del(&clk
->clks_node
);
4299 if (clk
->min_rate
> clk
->core
->req_rate
||
4300 clk
->max_rate
< clk
->core
->req_rate
)
4301 clk_core_set_rate_nolock(clk
->core
, clk
->core
->req_rate
);
4303 owner
= clk
->core
->owner
;
4304 kref_put(&clk
->core
->ref
, __clk_release
);
4306 clk_prepare_unlock();
4313 /*** clk rate change notifiers ***/
4316 * clk_notifier_register - add a clk rate change notifier
4317 * @clk: struct clk * to watch
4318 * @nb: struct notifier_block * with callback info
4320 * Request notification when clk's rate changes. This uses an SRCU
4321 * notifier because we want it to block and notifier unregistrations are
4322 * uncommon. The callbacks associated with the notifier must not
4323 * re-enter into the clk framework by calling any top-level clk APIs;
4324 * this will cause a nested prepare_lock mutex.
4326 * In all notification cases (pre, post and abort rate change) the original
4327 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
4328 * and the new frequency is passed via struct clk_notifier_data.new_rate.
4330 * clk_notifier_register() must be called from non-atomic context.
4331 * Returns -EINVAL if called with null arguments, -ENOMEM upon
4332 * allocation failure; otherwise, passes along the return value of
4333 * srcu_notifier_chain_register().
4335 int clk_notifier_register(struct clk
*clk
, struct notifier_block
*nb
)
4337 struct clk_notifier
*cn
;
4345 /* search the list of notifiers for this clk */
4346 list_for_each_entry(cn
, &clk_notifier_list
, node
)
4350 /* if clk wasn't in the notifier list, allocate new clk_notifier */
4351 cn
= kzalloc(sizeof(*cn
), GFP_KERNEL
);
4356 srcu_init_notifier_head(&cn
->notifier_head
);
4358 list_add(&cn
->node
, &clk_notifier_list
);
4361 ret
= srcu_notifier_chain_register(&cn
->notifier_head
, nb
);
4363 clk
->core
->notifier_count
++;
4366 clk_prepare_unlock();
4370 EXPORT_SYMBOL_GPL(clk_notifier_register
);
4373 * clk_notifier_unregister - remove a clk rate change notifier
4374 * @clk: struct clk *
4375 * @nb: struct notifier_block * with callback info
4377 * Request no further notification for changes to 'clk' and frees memory
4378 * allocated in clk_notifier_register.
4380 * Returns -EINVAL if called with null arguments; otherwise, passes
4381 * along the return value of srcu_notifier_chain_unregister().
4383 int clk_notifier_unregister(struct clk
*clk
, struct notifier_block
*nb
)
4385 struct clk_notifier
*cn
;
4393 list_for_each_entry(cn
, &clk_notifier_list
, node
) {
4394 if (cn
->clk
== clk
) {
4395 ret
= srcu_notifier_chain_unregister(&cn
->notifier_head
, nb
);
4397 clk
->core
->notifier_count
--;
4399 /* XXX the notifier code should handle this better */
4400 if (!cn
->notifier_head
.head
) {
4401 srcu_cleanup_notifier_head(&cn
->notifier_head
);
4402 list_del(&cn
->node
);
4409 clk_prepare_unlock();
4413 EXPORT_SYMBOL_GPL(clk_notifier_unregister
);
4415 struct clk_notifier_devres
{
4417 struct notifier_block
*nb
;
4420 static void devm_clk_notifier_release(struct device
*dev
, void *res
)
4422 struct clk_notifier_devres
*devres
= res
;
4424 clk_notifier_unregister(devres
->clk
, devres
->nb
);
4427 int devm_clk_notifier_register(struct device
*dev
, struct clk
*clk
,
4428 struct notifier_block
*nb
)
4430 struct clk_notifier_devres
*devres
;
4433 devres
= devres_alloc(devm_clk_notifier_release
,
4434 sizeof(*devres
), GFP_KERNEL
);
4439 ret
= clk_notifier_register(clk
, nb
);
4444 devres_free(devres
);
4449 EXPORT_SYMBOL_GPL(devm_clk_notifier_register
);
4452 static void clk_core_reparent_orphans(void)
4455 clk_core_reparent_orphans_nolock();
4456 clk_prepare_unlock();
4460 * struct of_clk_provider - Clock provider registration structure
4461 * @link: Entry in global list of clock providers
4462 * @node: Pointer to device tree node of clock provider
4463 * @get: Get clock callback. Returns NULL or a struct clk for the
4464 * given clock specifier
4465 * @get_hw: Get clk_hw callback. Returns NULL, ERR_PTR or a
4466 * struct clk_hw for the given clock specifier
4467 * @data: context pointer to be passed into @get callback
4469 struct of_clk_provider
{
4470 struct list_head link
;
4472 struct device_node
*node
;
4473 struct clk
*(*get
)(struct of_phandle_args
*clkspec
, void *data
);
4474 struct clk_hw
*(*get_hw
)(struct of_phandle_args
*clkspec
, void *data
);
4478 extern struct of_device_id __clk_of_table
;
4479 static const struct of_device_id __clk_of_table_sentinel
4480 __used
__section("__clk_of_table_end");
4482 static LIST_HEAD(of_clk_providers
);
4483 static DEFINE_MUTEX(of_clk_mutex
);
4485 struct clk
*of_clk_src_simple_get(struct of_phandle_args
*clkspec
,
4490 EXPORT_SYMBOL_GPL(of_clk_src_simple_get
);
4492 struct clk_hw
*of_clk_hw_simple_get(struct of_phandle_args
*clkspec
, void *data
)
4496 EXPORT_SYMBOL_GPL(of_clk_hw_simple_get
);
4498 struct clk
*of_clk_src_onecell_get(struct of_phandle_args
*clkspec
, void *data
)
4500 struct clk_onecell_data
*clk_data
= data
;
4501 unsigned int idx
= clkspec
->args
[0];
4503 if (idx
>= clk_data
->clk_num
) {
4504 pr_err("%s: invalid clock index %u\n", __func__
, idx
);
4505 return ERR_PTR(-EINVAL
);
4508 return clk_data
->clks
[idx
];
4510 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get
);
4513 of_clk_hw_onecell_get(struct of_phandle_args
*clkspec
, void *data
)
4515 struct clk_hw_onecell_data
*hw_data
= data
;
4516 unsigned int idx
= clkspec
->args
[0];
4518 if (idx
>= hw_data
->num
) {
4519 pr_err("%s: invalid index %u\n", __func__
, idx
);
4520 return ERR_PTR(-EINVAL
);
4523 return hw_data
->hws
[idx
];
4525 EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get
);
4528 * of_clk_add_provider() - Register a clock provider for a node
4529 * @np: Device node pointer associated with clock provider
4530 * @clk_src_get: callback for decoding clock
4531 * @data: context pointer for @clk_src_get callback.
4533 * This function is *deprecated*. Use of_clk_add_hw_provider() instead.
4535 int of_clk_add_provider(struct device_node
*np
,
4536 struct clk
*(*clk_src_get
)(struct of_phandle_args
*clkspec
,
4540 struct of_clk_provider
*cp
;
4543 cp
= kzalloc(sizeof(*cp
), GFP_KERNEL
);
4547 cp
->node
= of_node_get(np
);
4549 cp
->get
= clk_src_get
;
4551 mutex_lock(&of_clk_mutex
);
4552 list_add(&cp
->link
, &of_clk_providers
);
4553 mutex_unlock(&of_clk_mutex
);
4554 pr_debug("Added clock from %pOF\n", np
);
4556 clk_core_reparent_orphans();
4558 ret
= of_clk_set_defaults(np
, true);
4560 of_clk_del_provider(np
);
4562 fwnode_dev_initialized(&np
->fwnode
, true);
4566 EXPORT_SYMBOL_GPL(of_clk_add_provider
);
4569 * of_clk_add_hw_provider() - Register a clock provider for a node
4570 * @np: Device node pointer associated with clock provider
4571 * @get: callback for decoding clk_hw
4572 * @data: context pointer for @get callback.
4574 int of_clk_add_hw_provider(struct device_node
*np
,
4575 struct clk_hw
*(*get
)(struct of_phandle_args
*clkspec
,
4579 struct of_clk_provider
*cp
;
4582 cp
= kzalloc(sizeof(*cp
), GFP_KERNEL
);
4586 cp
->node
= of_node_get(np
);
4590 mutex_lock(&of_clk_mutex
);
4591 list_add(&cp
->link
, &of_clk_providers
);
4592 mutex_unlock(&of_clk_mutex
);
4593 pr_debug("Added clk_hw provider from %pOF\n", np
);
4595 clk_core_reparent_orphans();
4597 ret
= of_clk_set_defaults(np
, true);
4599 of_clk_del_provider(np
);
4601 fwnode_dev_initialized(&np
->fwnode
, true);
4605 EXPORT_SYMBOL_GPL(of_clk_add_hw_provider
);
4607 static void devm_of_clk_release_provider(struct device
*dev
, void *res
)
4609 of_clk_del_provider(*(struct device_node
**)res
);
4613 * We allow a child device to use its parent device as the clock provider node
4614 * for cases like MFD sub-devices where the child device driver wants to use
4615 * devm_*() APIs but not list the device in DT as a sub-node.
4617 static struct device_node
*get_clk_provider_node(struct device
*dev
)
4619 struct device_node
*np
, *parent_np
;
4622 parent_np
= dev
->parent
? dev
->parent
->of_node
: NULL
;
4624 if (!of_find_property(np
, "#clock-cells", NULL
))
4625 if (of_find_property(parent_np
, "#clock-cells", NULL
))
4632 * devm_of_clk_add_hw_provider() - Managed clk provider node registration
4633 * @dev: Device acting as the clock provider (used for DT node and lifetime)
4634 * @get: callback for decoding clk_hw
4635 * @data: context pointer for @get callback
4637 * Registers clock provider for given device's node. If the device has no DT
4638 * node or if the device node lacks of clock provider information (#clock-cells)
4639 * then the parent device's node is scanned for this information. If parent node
4640 * has the #clock-cells then it is used in registration. Provider is
4641 * automatically released at device exit.
4643 * Return: 0 on success or an errno on failure.
4645 int devm_of_clk_add_hw_provider(struct device
*dev
,
4646 struct clk_hw
*(*get
)(struct of_phandle_args
*clkspec
,
4650 struct device_node
**ptr
, *np
;
4653 ptr
= devres_alloc(devm_of_clk_release_provider
, sizeof(*ptr
),
4658 np
= get_clk_provider_node(dev
);
4659 ret
= of_clk_add_hw_provider(np
, get
, data
);
4662 devres_add(dev
, ptr
);
4669 EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider
);
4672 * of_clk_del_provider() - Remove a previously registered clock provider
4673 * @np: Device node pointer associated with clock provider
4675 void of_clk_del_provider(struct device_node
*np
)
4677 struct of_clk_provider
*cp
;
4679 mutex_lock(&of_clk_mutex
);
4680 list_for_each_entry(cp
, &of_clk_providers
, link
) {
4681 if (cp
->node
== np
) {
4682 list_del(&cp
->link
);
4683 fwnode_dev_initialized(&np
->fwnode
, false);
4684 of_node_put(cp
->node
);
4689 mutex_unlock(&of_clk_mutex
);
4691 EXPORT_SYMBOL_GPL(of_clk_del_provider
);
4693 static int devm_clk_provider_match(struct device
*dev
, void *res
, void *data
)
4695 struct device_node
**np
= res
;
4697 if (WARN_ON(!np
|| !*np
))
4704 * devm_of_clk_del_provider() - Remove clock provider registered using devm
4705 * @dev: Device to whose lifetime the clock provider was bound
4707 void devm_of_clk_del_provider(struct device
*dev
)
4710 struct device_node
*np
= get_clk_provider_node(dev
);
4712 ret
= devres_release(dev
, devm_of_clk_release_provider
,
4713 devm_clk_provider_match
, np
);
4717 EXPORT_SYMBOL(devm_of_clk_del_provider
);
4720 * of_parse_clkspec() - Parse a DT clock specifier for a given device node
4721 * @np: device node to parse clock specifier from
4722 * @index: index of phandle to parse clock out of. If index < 0, @name is used
4723 * @name: clock name to find and parse. If name is NULL, the index is used
4724 * @out_args: Result of parsing the clock specifier
4726 * Parses a device node's "clocks" and "clock-names" properties to find the
4727 * phandle and cells for the index or name that is desired. The resulting clock
4728 * specifier is placed into @out_args, or an errno is returned when there's a
4729 * parsing error. The @index argument is ignored if @name is non-NULL.
4733 * phandle1: clock-controller@1 {
4734 * #clock-cells = <2>;
4737 * phandle2: clock-controller@2 {
4738 * #clock-cells = <1>;
4741 * clock-consumer@3 {
4742 * clocks = <&phandle1 1 2 &phandle2 3>;
4743 * clock-names = "name1", "name2";
4746 * To get a device_node for `clock-controller@2' node you may call this
4747 * function a few different ways:
4749 * of_parse_clkspec(clock-consumer@3, -1, "name2", &args);
4750 * of_parse_clkspec(clock-consumer@3, 1, NULL, &args);
4751 * of_parse_clkspec(clock-consumer@3, 1, "name2", &args);
4753 * Return: 0 upon successfully parsing the clock specifier. Otherwise, -ENOENT
4754 * if @name is NULL or -EINVAL if @name is non-NULL and it can't be found in
4755 * the "clock-names" property of @np.
4757 static int of_parse_clkspec(const struct device_node
*np
, int index
,
4758 const char *name
, struct of_phandle_args
*out_args
)
4762 /* Walk up the tree of devices looking for a clock property that matches */
4765 * For named clocks, first look up the name in the
4766 * "clock-names" property. If it cannot be found, then index
4767 * will be an error code and of_parse_phandle_with_args() will
4771 index
= of_property_match_string(np
, "clock-names", name
);
4772 ret
= of_parse_phandle_with_args(np
, "clocks", "#clock-cells",
4776 if (name
&& index
>= 0)
4780 * No matching clock found on this node. If the parent node
4781 * has a "clock-ranges" property, then we can try one of its
4785 if (np
&& !of_get_property(np
, "clock-ranges", NULL
))
4793 static struct clk_hw
*
4794 __of_clk_get_hw_from_provider(struct of_clk_provider
*provider
,
4795 struct of_phandle_args
*clkspec
)
4799 if (provider
->get_hw
)
4800 return provider
->get_hw(clkspec
, provider
->data
);
4802 clk
= provider
->get(clkspec
, provider
->data
);
4804 return ERR_CAST(clk
);
4805 return __clk_get_hw(clk
);
4808 static struct clk_hw
*
4809 of_clk_get_hw_from_clkspec(struct of_phandle_args
*clkspec
)
4811 struct of_clk_provider
*provider
;
4812 struct clk_hw
*hw
= ERR_PTR(-EPROBE_DEFER
);
4815 return ERR_PTR(-EINVAL
);
4817 mutex_lock(&of_clk_mutex
);
4818 list_for_each_entry(provider
, &of_clk_providers
, link
) {
4819 if (provider
->node
== clkspec
->np
) {
4820 hw
= __of_clk_get_hw_from_provider(provider
, clkspec
);
4825 mutex_unlock(&of_clk_mutex
);
4831 * of_clk_get_from_provider() - Lookup a clock from a clock provider
4832 * @clkspec: pointer to a clock specifier data structure
4834 * This function looks up a struct clk from the registered list of clock
4835 * providers, an input is a clock specifier data structure as returned
4836 * from the of_parse_phandle_with_args() function call.
4838 struct clk
*of_clk_get_from_provider(struct of_phandle_args
*clkspec
)
4840 struct clk_hw
*hw
= of_clk_get_hw_from_clkspec(clkspec
);
4842 return clk_hw_create_clk(NULL
, hw
, NULL
, __func__
);
4844 EXPORT_SYMBOL_GPL(of_clk_get_from_provider
);
4846 struct clk_hw
*of_clk_get_hw(struct device_node
*np
, int index
,
4851 struct of_phandle_args clkspec
;
4853 ret
= of_parse_clkspec(np
, index
, con_id
, &clkspec
);
4855 return ERR_PTR(ret
);
4857 hw
= of_clk_get_hw_from_clkspec(&clkspec
);
4858 of_node_put(clkspec
.np
);
4863 static struct clk
*__of_clk_get(struct device_node
*np
,
4864 int index
, const char *dev_id
,
4867 struct clk_hw
*hw
= of_clk_get_hw(np
, index
, con_id
);
4869 return clk_hw_create_clk(NULL
, hw
, dev_id
, con_id
);
4872 struct clk
*of_clk_get(struct device_node
*np
, int index
)
4874 return __of_clk_get(np
, index
, np
->full_name
, NULL
);
4876 EXPORT_SYMBOL(of_clk_get
);
4879 * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
4880 * @np: pointer to clock consumer node
4881 * @name: name of consumer's clock input, or NULL for the first clock reference
4883 * This function parses the clocks and clock-names properties,
4884 * and uses them to look up the struct clk from the registered list of clock
4887 struct clk
*of_clk_get_by_name(struct device_node
*np
, const char *name
)
4890 return ERR_PTR(-ENOENT
);
4892 return __of_clk_get(np
, 0, np
->full_name
, name
);
4894 EXPORT_SYMBOL(of_clk_get_by_name
);
4897 * of_clk_get_parent_count() - Count the number of clocks a device node has
4898 * @np: device node to count
4900 * Returns: The number of clocks that are possible parents of this node
4902 unsigned int of_clk_get_parent_count(const struct device_node
*np
)
4906 count
= of_count_phandle_with_args(np
, "clocks", "#clock-cells");
4912 EXPORT_SYMBOL_GPL(of_clk_get_parent_count
);
4914 const char *of_clk_get_parent_name(const struct device_node
*np
, int index
)
4916 struct of_phandle_args clkspec
;
4917 struct property
*prop
;
4918 const char *clk_name
;
4925 rc
= of_parse_phandle_with_args(np
, "clocks", "#clock-cells", index
,
4930 index
= clkspec
.args_count
? clkspec
.args
[0] : 0;
4933 /* if there is an indices property, use it to transfer the index
4934 * specified into an array offset for the clock-output-names property.
4936 of_property_for_each_u32(clkspec
.np
, "clock-indices", prop
, vp
, pv
) {
4943 /* We went off the end of 'clock-indices' without finding it */
4947 if (of_property_read_string_index(clkspec
.np
, "clock-output-names",
4951 * Best effort to get the name if the clock has been
4952 * registered with the framework. If the clock isn't
4953 * registered, we return the node name as the name of
4954 * the clock as long as #clock-cells = 0.
4956 clk
= of_clk_get_from_provider(&clkspec
);
4958 if (clkspec
.args_count
== 0)
4959 clk_name
= clkspec
.np
->name
;
4963 clk_name
= __clk_get_name(clk
);
4969 of_node_put(clkspec
.np
);
4972 EXPORT_SYMBOL_GPL(of_clk_get_parent_name
);
4975 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
4977 * @np: Device node pointer associated with clock provider
4978 * @parents: pointer to char array that hold the parents' names
4979 * @size: size of the @parents array
4981 * Return: number of parents for the clock node.
4983 int of_clk_parent_fill(struct device_node
*np
, const char **parents
,
4988 while (i
< size
&& (parents
[i
] = of_clk_get_parent_name(np
, i
)) != NULL
)
4993 EXPORT_SYMBOL_GPL(of_clk_parent_fill
);
4995 struct clock_provider
{
4996 void (*clk_init_cb
)(struct device_node
*);
4997 struct device_node
*np
;
4998 struct list_head node
;
5002 * This function looks for a parent clock. If there is one, then it
5003 * checks that the provider for this parent clock was initialized, in
5004 * this case the parent clock will be ready.
5006 static int parent_ready(struct device_node
*np
)
5011 struct clk
*clk
= of_clk_get(np
, i
);
5013 /* this parent is ready we can check the next one */
5020 /* at least one parent is not ready, we exit now */
5021 if (PTR_ERR(clk
) == -EPROBE_DEFER
)
5025 * Here we make assumption that the device tree is
5026 * written correctly. So an error means that there is
5027 * no more parent. As we didn't exit yet, then the
5028 * previous parent are ready. If there is no clock
5029 * parent, no need to wait for them, then we can
5030 * consider their absence as being ready
5037 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
5038 * @np: Device node pointer associated with clock provider
5039 * @index: clock index
5040 * @flags: pointer to top-level framework flags
5042 * Detects if the clock-critical property exists and, if so, sets the
5043 * corresponding CLK_IS_CRITICAL flag.
5045 * Do not use this function. It exists only for legacy Device Tree
5046 * bindings, such as the one-clock-per-node style that are outdated.
5047 * Those bindings typically put all clock data into .dts and the Linux
5048 * driver has no clock data, thus making it impossible to set this flag
5049 * correctly from the driver. Only those drivers may call
5050 * of_clk_detect_critical from their setup functions.
5052 * Return: error code or zero on success
5054 int of_clk_detect_critical(struct device_node
*np
, int index
,
5055 unsigned long *flags
)
5057 struct property
*prop
;
5064 of_property_for_each_u32(np
, "clock-critical", prop
, cur
, idx
)
5066 *flags
|= CLK_IS_CRITICAL
;
5072 * of_clk_init() - Scan and init clock providers from the DT
5073 * @matches: array of compatible values and init functions for providers.
5075 * This function scans the device tree for matching clock providers
5076 * and calls their initialization functions. It also does it by trying
5077 * to follow the dependencies.
5079 void __init
of_clk_init(const struct of_device_id
*matches
)
5081 const struct of_device_id
*match
;
5082 struct device_node
*np
;
5083 struct clock_provider
*clk_provider
, *next
;
5086 LIST_HEAD(clk_provider_list
);
5089 matches
= &__clk_of_table
;
5091 /* First prepare the list of the clocks providers */
5092 for_each_matching_node_and_match(np
, matches
, &match
) {
5093 struct clock_provider
*parent
;
5095 if (!of_device_is_available(np
))
5098 parent
= kzalloc(sizeof(*parent
), GFP_KERNEL
);
5100 list_for_each_entry_safe(clk_provider
, next
,
5101 &clk_provider_list
, node
) {
5102 list_del(&clk_provider
->node
);
5103 of_node_put(clk_provider
->np
);
5104 kfree(clk_provider
);
5110 parent
->clk_init_cb
= match
->data
;
5111 parent
->np
= of_node_get(np
);
5112 list_add_tail(&parent
->node
, &clk_provider_list
);
5115 while (!list_empty(&clk_provider_list
)) {
5116 is_init_done
= false;
5117 list_for_each_entry_safe(clk_provider
, next
,
5118 &clk_provider_list
, node
) {
5119 if (force
|| parent_ready(clk_provider
->np
)) {
5121 /* Don't populate platform devices */
5122 of_node_set_flag(clk_provider
->np
,
5125 clk_provider
->clk_init_cb(clk_provider
->np
);
5126 of_clk_set_defaults(clk_provider
->np
, true);
5128 list_del(&clk_provider
->node
);
5129 of_node_put(clk_provider
->np
);
5130 kfree(clk_provider
);
5131 is_init_done
= true;
5136 * We didn't manage to initialize any of the
5137 * remaining providers during the last loop, so now we
5138 * initialize all the remaining ones unconditionally
5139 * in case the clock parent was not mandatory