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
= ERR_PTR(-ENOENT
);
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
);
1167 static int clk_core_prepare_enable(struct clk_core
*core
)
1171 ret
= clk_core_prepare_lock(core
);
1175 ret
= clk_core_enable_lock(core
);
1177 clk_core_unprepare_lock(core
);
1182 static void clk_core_disable_unprepare(struct clk_core
*core
)
1184 clk_core_disable_lock(core
);
1185 clk_core_unprepare_lock(core
);
1188 static void __init
clk_unprepare_unused_subtree(struct clk_core
*core
)
1190 struct clk_core
*child
;
1192 lockdep_assert_held(&prepare_lock
);
1194 hlist_for_each_entry(child
, &core
->children
, child_node
)
1195 clk_unprepare_unused_subtree(child
);
1197 if (core
->prepare_count
)
1200 if (core
->flags
& CLK_IGNORE_UNUSED
)
1203 if (clk_pm_runtime_get(core
))
1206 if (clk_core_is_prepared(core
)) {
1207 trace_clk_unprepare(core
);
1208 if (core
->ops
->unprepare_unused
)
1209 core
->ops
->unprepare_unused(core
->hw
);
1210 else if (core
->ops
->unprepare
)
1211 core
->ops
->unprepare(core
->hw
);
1212 trace_clk_unprepare_complete(core
);
1215 clk_pm_runtime_put(core
);
1218 static void __init
clk_disable_unused_subtree(struct clk_core
*core
)
1220 struct clk_core
*child
;
1221 unsigned long flags
;
1223 lockdep_assert_held(&prepare_lock
);
1225 hlist_for_each_entry(child
, &core
->children
, child_node
)
1226 clk_disable_unused_subtree(child
);
1228 if (core
->flags
& CLK_OPS_PARENT_ENABLE
)
1229 clk_core_prepare_enable(core
->parent
);
1231 if (clk_pm_runtime_get(core
))
1234 flags
= clk_enable_lock();
1236 if (core
->enable_count
)
1239 if (core
->flags
& CLK_IGNORE_UNUSED
)
1243 * some gate clocks have special needs during the disable-unused
1244 * sequence. call .disable_unused if available, otherwise fall
1247 if (clk_core_is_enabled(core
)) {
1248 trace_clk_disable(core
);
1249 if (core
->ops
->disable_unused
)
1250 core
->ops
->disable_unused(core
->hw
);
1251 else if (core
->ops
->disable
)
1252 core
->ops
->disable(core
->hw
);
1253 trace_clk_disable_complete(core
);
1257 clk_enable_unlock(flags
);
1258 clk_pm_runtime_put(core
);
1260 if (core
->flags
& CLK_OPS_PARENT_ENABLE
)
1261 clk_core_disable_unprepare(core
->parent
);
1264 static bool clk_ignore_unused __initdata
;
1265 static int __init
clk_ignore_unused_setup(char *__unused
)
1267 clk_ignore_unused
= true;
1270 __setup("clk_ignore_unused", clk_ignore_unused_setup
);
1272 static int __init
clk_disable_unused(void)
1274 struct clk_core
*core
;
1276 if (clk_ignore_unused
) {
1277 pr_warn("clk: Not disabling unused clocks\n");
1283 hlist_for_each_entry(core
, &clk_root_list
, child_node
)
1284 clk_disable_unused_subtree(core
);
1286 hlist_for_each_entry(core
, &clk_orphan_list
, child_node
)
1287 clk_disable_unused_subtree(core
);
1289 hlist_for_each_entry(core
, &clk_root_list
, child_node
)
1290 clk_unprepare_unused_subtree(core
);
1292 hlist_for_each_entry(core
, &clk_orphan_list
, child_node
)
1293 clk_unprepare_unused_subtree(core
);
1295 clk_prepare_unlock();
1299 late_initcall_sync(clk_disable_unused
);
1301 static int clk_core_determine_round_nolock(struct clk_core
*core
,
1302 struct clk_rate_request
*req
)
1306 lockdep_assert_held(&prepare_lock
);
1312 * At this point, core protection will be disabled if
1313 * - if the provider is not protected at all
1314 * - if the calling consumer is the only one which has exclusivity
1317 if (clk_core_rate_is_protected(core
)) {
1318 req
->rate
= core
->rate
;
1319 } else if (core
->ops
->determine_rate
) {
1320 return core
->ops
->determine_rate(core
->hw
, req
);
1321 } else if (core
->ops
->round_rate
) {
1322 rate
= core
->ops
->round_rate(core
->hw
, req
->rate
,
1323 &req
->best_parent_rate
);
1335 static void clk_core_init_rate_req(struct clk_core
* const core
,
1336 struct clk_rate_request
*req
)
1338 struct clk_core
*parent
;
1340 if (WARN_ON(!core
|| !req
))
1343 parent
= core
->parent
;
1345 req
->best_parent_hw
= parent
->hw
;
1346 req
->best_parent_rate
= parent
->rate
;
1348 req
->best_parent_hw
= NULL
;
1349 req
->best_parent_rate
= 0;
1353 static bool clk_core_can_round(struct clk_core
* const core
)
1355 return core
->ops
->determine_rate
|| core
->ops
->round_rate
;
1358 static int clk_core_round_rate_nolock(struct clk_core
*core
,
1359 struct clk_rate_request
*req
)
1361 lockdep_assert_held(&prepare_lock
);
1368 clk_core_init_rate_req(core
, req
);
1370 if (clk_core_can_round(core
))
1371 return clk_core_determine_round_nolock(core
, req
);
1372 else if (core
->flags
& CLK_SET_RATE_PARENT
)
1373 return clk_core_round_rate_nolock(core
->parent
, req
);
1375 req
->rate
= core
->rate
;
1380 * __clk_determine_rate - get the closest rate actually supported by a clock
1381 * @hw: determine the rate of this clock
1382 * @req: target rate request
1384 * Useful for clk_ops such as .set_rate and .determine_rate.
1386 int __clk_determine_rate(struct clk_hw
*hw
, struct clk_rate_request
*req
)
1393 return clk_core_round_rate_nolock(hw
->core
, req
);
1395 EXPORT_SYMBOL_GPL(__clk_determine_rate
);
1398 * clk_hw_round_rate() - round the given rate for a hw clk
1399 * @hw: the hw clk for which we are rounding a rate
1400 * @rate: the rate which is to be rounded
1402 * Takes in a rate as input and rounds it to a rate that the clk can actually
1405 * Context: prepare_lock must be held.
1406 * For clk providers to call from within clk_ops such as .round_rate,
1409 * Return: returns rounded rate of hw clk if clk supports round_rate operation
1410 * else returns the parent rate.
1412 unsigned long clk_hw_round_rate(struct clk_hw
*hw
, unsigned long rate
)
1415 struct clk_rate_request req
;
1417 clk_core_get_boundaries(hw
->core
, &req
.min_rate
, &req
.max_rate
);
1420 ret
= clk_core_round_rate_nolock(hw
->core
, &req
);
1426 EXPORT_SYMBOL_GPL(clk_hw_round_rate
);
1429 * clk_round_rate - round the given rate for a clk
1430 * @clk: the clk for which we are rounding a rate
1431 * @rate: the rate which is to be rounded
1433 * Takes in a rate as input and rounds it to a rate that the clk can actually
1434 * use which is then returned. If clk doesn't support round_rate operation
1435 * then the parent rate is returned.
1437 long clk_round_rate(struct clk
*clk
, unsigned long rate
)
1439 struct clk_rate_request req
;
1447 if (clk
->exclusive_count
)
1448 clk_core_rate_unprotect(clk
->core
);
1450 clk_core_get_boundaries(clk
->core
, &req
.min_rate
, &req
.max_rate
);
1453 ret
= clk_core_round_rate_nolock(clk
->core
, &req
);
1455 if (clk
->exclusive_count
)
1456 clk_core_rate_protect(clk
->core
);
1458 clk_prepare_unlock();
1465 EXPORT_SYMBOL_GPL(clk_round_rate
);
1468 * __clk_notify - call clk notifier chain
1469 * @core: clk that is changing rate
1470 * @msg: clk notifier type (see include/linux/clk.h)
1471 * @old_rate: old clk rate
1472 * @new_rate: new clk rate
1474 * Triggers a notifier call chain on the clk rate-change notification
1475 * for 'clk'. Passes a pointer to the struct clk and the previous
1476 * and current rates to the notifier callback. Intended to be called by
1477 * internal clock code only. Returns NOTIFY_DONE from the last driver
1478 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1479 * a driver returns that.
1481 static int __clk_notify(struct clk_core
*core
, unsigned long msg
,
1482 unsigned long old_rate
, unsigned long new_rate
)
1484 struct clk_notifier
*cn
;
1485 struct clk_notifier_data cnd
;
1486 int ret
= NOTIFY_DONE
;
1488 cnd
.old_rate
= old_rate
;
1489 cnd
.new_rate
= new_rate
;
1491 list_for_each_entry(cn
, &clk_notifier_list
, node
) {
1492 if (cn
->clk
->core
== core
) {
1494 ret
= srcu_notifier_call_chain(&cn
->notifier_head
, msg
,
1496 if (ret
& NOTIFY_STOP_MASK
)
1505 * __clk_recalc_accuracies
1506 * @core: first clk in the subtree
1508 * Walks the subtree of clks starting with clk and recalculates accuracies as
1509 * it goes. Note that if a clk does not implement the .recalc_accuracy
1510 * callback then it is assumed that the clock will take on the accuracy of its
1513 static void __clk_recalc_accuracies(struct clk_core
*core
)
1515 unsigned long parent_accuracy
= 0;
1516 struct clk_core
*child
;
1518 lockdep_assert_held(&prepare_lock
);
1521 parent_accuracy
= core
->parent
->accuracy
;
1523 if (core
->ops
->recalc_accuracy
)
1524 core
->accuracy
= core
->ops
->recalc_accuracy(core
->hw
,
1527 core
->accuracy
= parent_accuracy
;
1529 hlist_for_each_entry(child
, &core
->children
, child_node
)
1530 __clk_recalc_accuracies(child
);
1533 static long clk_core_get_accuracy_recalc(struct clk_core
*core
)
1535 if (core
&& (core
->flags
& CLK_GET_ACCURACY_NOCACHE
))
1536 __clk_recalc_accuracies(core
);
1538 return clk_core_get_accuracy_no_lock(core
);
1542 * clk_get_accuracy - return the accuracy of clk
1543 * @clk: the clk whose accuracy is being returned
1545 * Simply returns the cached accuracy of the clk, unless
1546 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1548 * If clk is NULL then returns 0.
1550 long clk_get_accuracy(struct clk
*clk
)
1558 accuracy
= clk_core_get_accuracy_recalc(clk
->core
);
1559 clk_prepare_unlock();
1563 EXPORT_SYMBOL_GPL(clk_get_accuracy
);
1565 static unsigned long clk_recalc(struct clk_core
*core
,
1566 unsigned long parent_rate
)
1568 unsigned long rate
= parent_rate
;
1570 if (core
->ops
->recalc_rate
&& !clk_pm_runtime_get(core
)) {
1571 rate
= core
->ops
->recalc_rate(core
->hw
, parent_rate
);
1572 clk_pm_runtime_put(core
);
1578 * __clk_recalc_rates
1579 * @core: first clk in the subtree
1580 * @msg: notification type (see include/linux/clk.h)
1582 * Walks the subtree of clks starting with clk and recalculates rates as it
1583 * goes. Note that if a clk does not implement the .recalc_rate callback then
1584 * it is assumed that the clock will take on the rate of its parent.
1586 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1589 static void __clk_recalc_rates(struct clk_core
*core
, unsigned long msg
)
1591 unsigned long old_rate
;
1592 unsigned long parent_rate
= 0;
1593 struct clk_core
*child
;
1595 lockdep_assert_held(&prepare_lock
);
1597 old_rate
= core
->rate
;
1600 parent_rate
= core
->parent
->rate
;
1602 core
->rate
= clk_recalc(core
, parent_rate
);
1605 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1606 * & ABORT_RATE_CHANGE notifiers
1608 if (core
->notifier_count
&& msg
)
1609 __clk_notify(core
, msg
, old_rate
, core
->rate
);
1611 hlist_for_each_entry(child
, &core
->children
, child_node
)
1612 __clk_recalc_rates(child
, msg
);
1615 static unsigned long clk_core_get_rate_recalc(struct clk_core
*core
)
1617 if (core
&& (core
->flags
& CLK_GET_RATE_NOCACHE
))
1618 __clk_recalc_rates(core
, 0);
1620 return clk_core_get_rate_nolock(core
);
1624 * clk_get_rate - return the rate of clk
1625 * @clk: the clk whose rate is being returned
1627 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1628 * is set, which means a recalc_rate will be issued.
1629 * If clk is NULL then returns 0.
1631 unsigned long clk_get_rate(struct clk
*clk
)
1639 rate
= clk_core_get_rate_recalc(clk
->core
);
1640 clk_prepare_unlock();
1644 EXPORT_SYMBOL_GPL(clk_get_rate
);
1646 static int clk_fetch_parent_index(struct clk_core
*core
,
1647 struct clk_core
*parent
)
1654 for (i
= 0; i
< core
->num_parents
; i
++) {
1655 /* Found it first try! */
1656 if (core
->parents
[i
].core
== parent
)
1659 /* Something else is here, so keep looking */
1660 if (core
->parents
[i
].core
)
1663 /* Maybe core hasn't been cached but the hw is all we know? */
1664 if (core
->parents
[i
].hw
) {
1665 if (core
->parents
[i
].hw
== parent
->hw
)
1668 /* Didn't match, but we're expecting a clk_hw */
1672 /* Maybe it hasn't been cached (clk_set_parent() path) */
1673 if (parent
== clk_core_get(core
, i
))
1676 /* Fallback to comparing globally unique names */
1677 if (core
->parents
[i
].name
&&
1678 !strcmp(parent
->name
, core
->parents
[i
].name
))
1682 if (i
== core
->num_parents
)
1685 core
->parents
[i
].core
= parent
;
1690 * clk_hw_get_parent_index - return the index of the parent clock
1691 * @hw: clk_hw associated with the clk being consumed
1693 * Fetches and returns the index of parent clock. Returns -EINVAL if the given
1694 * clock does not have a current parent.
1696 int clk_hw_get_parent_index(struct clk_hw
*hw
)
1698 struct clk_hw
*parent
= clk_hw_get_parent(hw
);
1700 if (WARN_ON(parent
== NULL
))
1703 return clk_fetch_parent_index(hw
->core
, parent
->core
);
1705 EXPORT_SYMBOL_GPL(clk_hw_get_parent_index
);
1708 * Update the orphan status of @core and all its children.
1710 static void clk_core_update_orphan_status(struct clk_core
*core
, bool is_orphan
)
1712 struct clk_core
*child
;
1714 core
->orphan
= is_orphan
;
1716 hlist_for_each_entry(child
, &core
->children
, child_node
)
1717 clk_core_update_orphan_status(child
, is_orphan
);
1720 static void clk_reparent(struct clk_core
*core
, struct clk_core
*new_parent
)
1722 bool was_orphan
= core
->orphan
;
1724 hlist_del(&core
->child_node
);
1727 bool becomes_orphan
= new_parent
->orphan
;
1729 /* avoid duplicate POST_RATE_CHANGE notifications */
1730 if (new_parent
->new_child
== core
)
1731 new_parent
->new_child
= NULL
;
1733 hlist_add_head(&core
->child_node
, &new_parent
->children
);
1735 if (was_orphan
!= becomes_orphan
)
1736 clk_core_update_orphan_status(core
, becomes_orphan
);
1738 hlist_add_head(&core
->child_node
, &clk_orphan_list
);
1740 clk_core_update_orphan_status(core
, true);
1743 core
->parent
= new_parent
;
1746 static struct clk_core
*__clk_set_parent_before(struct clk_core
*core
,
1747 struct clk_core
*parent
)
1749 unsigned long flags
;
1750 struct clk_core
*old_parent
= core
->parent
;
1753 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
1755 * 2. Migrate prepare state between parents and prevent race with
1758 * If the clock is not prepared, then a race with
1759 * clk_enable/disable() is impossible since we already have the
1760 * prepare lock (future calls to clk_enable() need to be preceded by
1763 * If the clock is prepared, migrate the prepared state to the new
1764 * parent and also protect against a race with clk_enable() by
1765 * forcing the clock and the new parent on. This ensures that all
1766 * future calls to clk_enable() are practically NOPs with respect to
1767 * hardware and software states.
1769 * See also: Comment for clk_set_parent() below.
1772 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
1773 if (core
->flags
& CLK_OPS_PARENT_ENABLE
) {
1774 clk_core_prepare_enable(old_parent
);
1775 clk_core_prepare_enable(parent
);
1778 /* migrate prepare count if > 0 */
1779 if (core
->prepare_count
) {
1780 clk_core_prepare_enable(parent
);
1781 clk_core_enable_lock(core
);
1784 /* update the clk tree topology */
1785 flags
= clk_enable_lock();
1786 clk_reparent(core
, parent
);
1787 clk_enable_unlock(flags
);
1792 static void __clk_set_parent_after(struct clk_core
*core
,
1793 struct clk_core
*parent
,
1794 struct clk_core
*old_parent
)
1797 * Finish the migration of prepare state and undo the changes done
1798 * for preventing a race with clk_enable().
1800 if (core
->prepare_count
) {
1801 clk_core_disable_lock(core
);
1802 clk_core_disable_unprepare(old_parent
);
1805 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
1806 if (core
->flags
& CLK_OPS_PARENT_ENABLE
) {
1807 clk_core_disable_unprepare(parent
);
1808 clk_core_disable_unprepare(old_parent
);
1812 static int __clk_set_parent(struct clk_core
*core
, struct clk_core
*parent
,
1815 unsigned long flags
;
1817 struct clk_core
*old_parent
;
1819 old_parent
= __clk_set_parent_before(core
, parent
);
1821 trace_clk_set_parent(core
, parent
);
1823 /* change clock input source */
1824 if (parent
&& core
->ops
->set_parent
)
1825 ret
= core
->ops
->set_parent(core
->hw
, p_index
);
1827 trace_clk_set_parent_complete(core
, parent
);
1830 flags
= clk_enable_lock();
1831 clk_reparent(core
, old_parent
);
1832 clk_enable_unlock(flags
);
1833 __clk_set_parent_after(core
, old_parent
, parent
);
1838 __clk_set_parent_after(core
, parent
, old_parent
);
1844 * __clk_speculate_rates
1845 * @core: first clk in the subtree
1846 * @parent_rate: the "future" rate of clk's parent
1848 * Walks the subtree of clks starting with clk, speculating rates as it
1849 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1851 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1852 * pre-rate change notifications and returns early if no clks in the
1853 * subtree have subscribed to the notifications. Note that if a clk does not
1854 * implement the .recalc_rate callback then it is assumed that the clock will
1855 * take on the rate of its parent.
1857 static int __clk_speculate_rates(struct clk_core
*core
,
1858 unsigned long parent_rate
)
1860 struct clk_core
*child
;
1861 unsigned long new_rate
;
1862 int ret
= NOTIFY_DONE
;
1864 lockdep_assert_held(&prepare_lock
);
1866 new_rate
= clk_recalc(core
, parent_rate
);
1868 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1869 if (core
->notifier_count
)
1870 ret
= __clk_notify(core
, PRE_RATE_CHANGE
, core
->rate
, new_rate
);
1872 if (ret
& NOTIFY_STOP_MASK
) {
1873 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1874 __func__
, core
->name
, ret
);
1878 hlist_for_each_entry(child
, &core
->children
, child_node
) {
1879 ret
= __clk_speculate_rates(child
, new_rate
);
1880 if (ret
& NOTIFY_STOP_MASK
)
1888 static void clk_calc_subtree(struct clk_core
*core
, unsigned long new_rate
,
1889 struct clk_core
*new_parent
, u8 p_index
)
1891 struct clk_core
*child
;
1893 core
->new_rate
= new_rate
;
1894 core
->new_parent
= new_parent
;
1895 core
->new_parent_index
= p_index
;
1896 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1897 core
->new_child
= NULL
;
1898 if (new_parent
&& new_parent
!= core
->parent
)
1899 new_parent
->new_child
= core
;
1901 hlist_for_each_entry(child
, &core
->children
, child_node
) {
1902 child
->new_rate
= clk_recalc(child
, new_rate
);
1903 clk_calc_subtree(child
, child
->new_rate
, NULL
, 0);
1908 * calculate the new rates returning the topmost clock that has to be
1911 static struct clk_core
*clk_calc_new_rates(struct clk_core
*core
,
1914 struct clk_core
*top
= core
;
1915 struct clk_core
*old_parent
, *parent
;
1916 unsigned long best_parent_rate
= 0;
1917 unsigned long new_rate
;
1918 unsigned long min_rate
;
1919 unsigned long max_rate
;
1924 if (IS_ERR_OR_NULL(core
))
1927 /* save parent rate, if it exists */
1928 parent
= old_parent
= core
->parent
;
1930 best_parent_rate
= parent
->rate
;
1932 clk_core_get_boundaries(core
, &min_rate
, &max_rate
);
1934 /* find the closest rate and parent clk/rate */
1935 if (clk_core_can_round(core
)) {
1936 struct clk_rate_request req
;
1939 req
.min_rate
= min_rate
;
1940 req
.max_rate
= max_rate
;
1942 clk_core_init_rate_req(core
, &req
);
1944 ret
= clk_core_determine_round_nolock(core
, &req
);
1948 best_parent_rate
= req
.best_parent_rate
;
1949 new_rate
= req
.rate
;
1950 parent
= req
.best_parent_hw
? req
.best_parent_hw
->core
: NULL
;
1952 if (new_rate
< min_rate
|| new_rate
> max_rate
)
1954 } else if (!parent
|| !(core
->flags
& CLK_SET_RATE_PARENT
)) {
1955 /* pass-through clock without adjustable parent */
1956 core
->new_rate
= core
->rate
;
1959 /* pass-through clock with adjustable parent */
1960 top
= clk_calc_new_rates(parent
, rate
);
1961 new_rate
= parent
->new_rate
;
1965 /* some clocks must be gated to change parent */
1966 if (parent
!= old_parent
&&
1967 (core
->flags
& CLK_SET_PARENT_GATE
) && core
->prepare_count
) {
1968 pr_debug("%s: %s not gated but wants to reparent\n",
1969 __func__
, core
->name
);
1973 /* try finding the new parent index */
1974 if (parent
&& core
->num_parents
> 1) {
1975 p_index
= clk_fetch_parent_index(core
, parent
);
1977 pr_debug("%s: clk %s can not be parent of clk %s\n",
1978 __func__
, parent
->name
, core
->name
);
1983 if ((core
->flags
& CLK_SET_RATE_PARENT
) && parent
&&
1984 best_parent_rate
!= parent
->rate
)
1985 top
= clk_calc_new_rates(parent
, best_parent_rate
);
1988 clk_calc_subtree(core
, new_rate
, parent
, p_index
);
1994 * Notify about rate changes in a subtree. Always walk down the whole tree
1995 * so that in case of an error we can walk down the whole tree again and
1998 static struct clk_core
*clk_propagate_rate_change(struct clk_core
*core
,
1999 unsigned long event
)
2001 struct clk_core
*child
, *tmp_clk
, *fail_clk
= NULL
;
2002 int ret
= NOTIFY_DONE
;
2004 if (core
->rate
== core
->new_rate
)
2007 if (core
->notifier_count
) {
2008 ret
= __clk_notify(core
, event
, core
->rate
, core
->new_rate
);
2009 if (ret
& NOTIFY_STOP_MASK
)
2013 hlist_for_each_entry(child
, &core
->children
, child_node
) {
2014 /* Skip children who will be reparented to another clock */
2015 if (child
->new_parent
&& child
->new_parent
!= core
)
2017 tmp_clk
= clk_propagate_rate_change(child
, event
);
2022 /* handle the new child who might not be in core->children yet */
2023 if (core
->new_child
) {
2024 tmp_clk
= clk_propagate_rate_change(core
->new_child
, event
);
2033 * walk down a subtree and set the new rates notifying the rate
2036 static void clk_change_rate(struct clk_core
*core
)
2038 struct clk_core
*child
;
2039 struct hlist_node
*tmp
;
2040 unsigned long old_rate
;
2041 unsigned long best_parent_rate
= 0;
2042 bool skip_set_rate
= false;
2043 struct clk_core
*old_parent
;
2044 struct clk_core
*parent
= NULL
;
2046 old_rate
= core
->rate
;
2048 if (core
->new_parent
) {
2049 parent
= core
->new_parent
;
2050 best_parent_rate
= core
->new_parent
->rate
;
2051 } else if (core
->parent
) {
2052 parent
= core
->parent
;
2053 best_parent_rate
= core
->parent
->rate
;
2056 if (clk_pm_runtime_get(core
))
2059 if (core
->flags
& CLK_SET_RATE_UNGATE
) {
2060 unsigned long flags
;
2062 clk_core_prepare(core
);
2063 flags
= clk_enable_lock();
2064 clk_core_enable(core
);
2065 clk_enable_unlock(flags
);
2068 if (core
->new_parent
&& core
->new_parent
!= core
->parent
) {
2069 old_parent
= __clk_set_parent_before(core
, core
->new_parent
);
2070 trace_clk_set_parent(core
, core
->new_parent
);
2072 if (core
->ops
->set_rate_and_parent
) {
2073 skip_set_rate
= true;
2074 core
->ops
->set_rate_and_parent(core
->hw
, core
->new_rate
,
2076 core
->new_parent_index
);
2077 } else if (core
->ops
->set_parent
) {
2078 core
->ops
->set_parent(core
->hw
, core
->new_parent_index
);
2081 trace_clk_set_parent_complete(core
, core
->new_parent
);
2082 __clk_set_parent_after(core
, core
->new_parent
, old_parent
);
2085 if (core
->flags
& CLK_OPS_PARENT_ENABLE
)
2086 clk_core_prepare_enable(parent
);
2088 trace_clk_set_rate(core
, core
->new_rate
);
2090 if (!skip_set_rate
&& core
->ops
->set_rate
)
2091 core
->ops
->set_rate(core
->hw
, core
->new_rate
, best_parent_rate
);
2093 trace_clk_set_rate_complete(core
, core
->new_rate
);
2095 core
->rate
= clk_recalc(core
, best_parent_rate
);
2097 if (core
->flags
& CLK_SET_RATE_UNGATE
) {
2098 unsigned long flags
;
2100 flags
= clk_enable_lock();
2101 clk_core_disable(core
);
2102 clk_enable_unlock(flags
);
2103 clk_core_unprepare(core
);
2106 if (core
->flags
& CLK_OPS_PARENT_ENABLE
)
2107 clk_core_disable_unprepare(parent
);
2109 if (core
->notifier_count
&& old_rate
!= core
->rate
)
2110 __clk_notify(core
, POST_RATE_CHANGE
, old_rate
, core
->rate
);
2112 if (core
->flags
& CLK_RECALC_NEW_RATES
)
2113 (void)clk_calc_new_rates(core
, core
->new_rate
);
2116 * Use safe iteration, as change_rate can actually swap parents
2117 * for certain clock types.
2119 hlist_for_each_entry_safe(child
, tmp
, &core
->children
, child_node
) {
2120 /* Skip children who will be reparented to another clock */
2121 if (child
->new_parent
&& child
->new_parent
!= core
)
2123 clk_change_rate(child
);
2126 /* handle the new child who might not be in core->children yet */
2127 if (core
->new_child
)
2128 clk_change_rate(core
->new_child
);
2130 clk_pm_runtime_put(core
);
2133 static unsigned long clk_core_req_round_rate_nolock(struct clk_core
*core
,
2134 unsigned long req_rate
)
2137 struct clk_rate_request req
;
2139 lockdep_assert_held(&prepare_lock
);
2144 /* simulate what the rate would be if it could be freely set */
2145 cnt
= clk_core_rate_nuke_protect(core
);
2149 clk_core_get_boundaries(core
, &req
.min_rate
, &req
.max_rate
);
2150 req
.rate
= req_rate
;
2152 ret
= clk_core_round_rate_nolock(core
, &req
);
2154 /* restore the protection */
2155 clk_core_rate_restore_protect(core
, cnt
);
2157 return ret
? 0 : req
.rate
;
2160 static int clk_core_set_rate_nolock(struct clk_core
*core
,
2161 unsigned long req_rate
)
2163 struct clk_core
*top
, *fail_clk
;
2170 rate
= clk_core_req_round_rate_nolock(core
, req_rate
);
2172 /* bail early if nothing to do */
2173 if (rate
== clk_core_get_rate_nolock(core
))
2176 /* fail on a direct rate set of a protected provider */
2177 if (clk_core_rate_is_protected(core
))
2180 /* calculate new rates and get the topmost changed clock */
2181 top
= clk_calc_new_rates(core
, req_rate
);
2185 ret
= clk_pm_runtime_get(core
);
2189 /* notify that we are about to change rates */
2190 fail_clk
= clk_propagate_rate_change(top
, PRE_RATE_CHANGE
);
2192 pr_debug("%s: failed to set %s rate\n", __func__
,
2194 clk_propagate_rate_change(top
, ABORT_RATE_CHANGE
);
2199 /* change the rates */
2200 clk_change_rate(top
);
2202 core
->req_rate
= req_rate
;
2204 clk_pm_runtime_put(core
);
2210 * clk_set_rate - specify a new rate for clk
2211 * @clk: the clk whose rate is being changed
2212 * @rate: the new rate for clk
2214 * In the simplest case clk_set_rate will only adjust the rate of clk.
2216 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
2217 * propagate up to clk's parent; whether or not this happens depends on the
2218 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
2219 * after calling .round_rate then upstream parent propagation is ignored. If
2220 * *parent_rate comes back with a new rate for clk's parent then we propagate
2221 * up to clk's parent and set its rate. Upward propagation will continue
2222 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
2223 * .round_rate stops requesting changes to clk's parent_rate.
2225 * Rate changes are accomplished via tree traversal that also recalculates the
2226 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
2228 * Returns 0 on success, -EERROR otherwise.
2230 int clk_set_rate(struct clk
*clk
, unsigned long rate
)
2237 /* prevent racing with updates to the clock topology */
2240 if (clk
->exclusive_count
)
2241 clk_core_rate_unprotect(clk
->core
);
2243 ret
= clk_core_set_rate_nolock(clk
->core
, rate
);
2245 if (clk
->exclusive_count
)
2246 clk_core_rate_protect(clk
->core
);
2248 clk_prepare_unlock();
2252 EXPORT_SYMBOL_GPL(clk_set_rate
);
2255 * clk_set_rate_exclusive - specify a new rate and get exclusive control
2256 * @clk: the clk whose rate is being changed
2257 * @rate: the new rate for clk
2259 * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
2260 * within a critical section
2262 * This can be used initially to ensure that at least 1 consumer is
2263 * satisfied when several consumers are competing for exclusivity over the
2264 * same clock provider.
2266 * The exclusivity is not applied if setting the rate failed.
2268 * Calls to clk_rate_exclusive_get() should be balanced with calls to
2269 * clk_rate_exclusive_put().
2271 * Returns 0 on success, -EERROR otherwise.
2273 int clk_set_rate_exclusive(struct clk
*clk
, unsigned long rate
)
2280 /* prevent racing with updates to the clock topology */
2284 * The temporary protection removal is not here, on purpose
2285 * This function is meant to be used instead of clk_rate_protect,
2286 * so before the consumer code path protect the clock provider
2289 ret
= clk_core_set_rate_nolock(clk
->core
, rate
);
2291 clk_core_rate_protect(clk
->core
);
2292 clk
->exclusive_count
++;
2295 clk_prepare_unlock();
2299 EXPORT_SYMBOL_GPL(clk_set_rate_exclusive
);
2302 * clk_set_rate_range - set a rate range for a clock source
2303 * @clk: clock source
2304 * @min: desired minimum clock rate in Hz, inclusive
2305 * @max: desired maximum clock rate in Hz, inclusive
2307 * Returns success (0) or negative errno.
2309 int clk_set_rate_range(struct clk
*clk
, unsigned long min
, unsigned long max
)
2312 unsigned long old_min
, old_max
, rate
;
2318 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
2319 __func__
, clk
->core
->name
, clk
->dev_id
, clk
->con_id
,
2326 if (clk
->exclusive_count
)
2327 clk_core_rate_unprotect(clk
->core
);
2329 /* Save the current values in case we need to rollback the change */
2330 old_min
= clk
->min_rate
;
2331 old_max
= clk
->max_rate
;
2332 clk
->min_rate
= min
;
2333 clk
->max_rate
= max
;
2335 rate
= clk_core_get_rate_nolock(clk
->core
);
2336 if (rate
< min
|| rate
> max
) {
2339 * We are in bit of trouble here, current rate is outside the
2340 * the requested range. We are going try to request appropriate
2341 * range boundary but there is a catch. It may fail for the
2342 * usual reason (clock broken, clock protected, etc) but also
2344 * - round_rate() was not favorable and fell on the wrong
2345 * side of the boundary
2346 * - the determine_rate() callback does not really check for
2347 * this corner case when determining the rate
2355 ret
= clk_core_set_rate_nolock(clk
->core
, rate
);
2357 /* rollback the changes */
2358 clk
->min_rate
= old_min
;
2359 clk
->max_rate
= old_max
;
2363 if (clk
->exclusive_count
)
2364 clk_core_rate_protect(clk
->core
);
2366 clk_prepare_unlock();
2370 EXPORT_SYMBOL_GPL(clk_set_rate_range
);
2373 * clk_set_min_rate - set a minimum clock rate for a clock source
2374 * @clk: clock source
2375 * @rate: desired minimum clock rate in Hz, inclusive
2377 * Returns success (0) or negative errno.
2379 int clk_set_min_rate(struct clk
*clk
, unsigned long rate
)
2384 return clk_set_rate_range(clk
, rate
, clk
->max_rate
);
2386 EXPORT_SYMBOL_GPL(clk_set_min_rate
);
2389 * clk_set_max_rate - set a maximum clock rate for a clock source
2390 * @clk: clock source
2391 * @rate: desired maximum clock rate in Hz, inclusive
2393 * Returns success (0) or negative errno.
2395 int clk_set_max_rate(struct clk
*clk
, unsigned long rate
)
2400 return clk_set_rate_range(clk
, clk
->min_rate
, rate
);
2402 EXPORT_SYMBOL_GPL(clk_set_max_rate
);
2405 * clk_get_parent - return the parent of a clk
2406 * @clk: the clk whose parent gets returned
2408 * Simply returns clk->parent. Returns NULL if clk is NULL.
2410 struct clk
*clk_get_parent(struct clk
*clk
)
2418 /* TODO: Create a per-user clk and change callers to call clk_put */
2419 parent
= !clk
->core
->parent
? NULL
: clk
->core
->parent
->hw
->clk
;
2420 clk_prepare_unlock();
2424 EXPORT_SYMBOL_GPL(clk_get_parent
);
2426 static struct clk_core
*__clk_init_parent(struct clk_core
*core
)
2430 if (core
->num_parents
> 1 && core
->ops
->get_parent
)
2431 index
= core
->ops
->get_parent(core
->hw
);
2433 return clk_core_get_parent_by_index(core
, index
);
2436 static void clk_core_reparent(struct clk_core
*core
,
2437 struct clk_core
*new_parent
)
2439 clk_reparent(core
, new_parent
);
2440 __clk_recalc_accuracies(core
);
2441 __clk_recalc_rates(core
, POST_RATE_CHANGE
);
2444 void clk_hw_reparent(struct clk_hw
*hw
, struct clk_hw
*new_parent
)
2449 clk_core_reparent(hw
->core
, !new_parent
? NULL
: new_parent
->core
);
2453 * clk_has_parent - check if a clock is a possible parent for another
2454 * @clk: clock source
2455 * @parent: parent clock source
2457 * This function can be used in drivers that need to check that a clock can be
2458 * the parent of another without actually changing the parent.
2460 * Returns true if @parent is a possible parent for @clk, false otherwise.
2462 bool clk_has_parent(struct clk
*clk
, struct clk
*parent
)
2464 struct clk_core
*core
, *parent_core
;
2467 /* NULL clocks should be nops, so return success if either is NULL. */
2468 if (!clk
|| !parent
)
2472 parent_core
= parent
->core
;
2474 /* Optimize for the case where the parent is already the parent. */
2475 if (core
->parent
== parent_core
)
2478 for (i
= 0; i
< core
->num_parents
; i
++)
2479 if (!strcmp(core
->parents
[i
].name
, parent_core
->name
))
2484 EXPORT_SYMBOL_GPL(clk_has_parent
);
2486 static int clk_core_set_parent_nolock(struct clk_core
*core
,
2487 struct clk_core
*parent
)
2491 unsigned long p_rate
= 0;
2493 lockdep_assert_held(&prepare_lock
);
2498 if (core
->parent
== parent
)
2501 /* verify ops for multi-parent clks */
2502 if (core
->num_parents
> 1 && !core
->ops
->set_parent
)
2505 /* check that we are allowed to re-parent if the clock is in use */
2506 if ((core
->flags
& CLK_SET_PARENT_GATE
) && core
->prepare_count
)
2509 if (clk_core_rate_is_protected(core
))
2512 /* try finding the new parent index */
2514 p_index
= clk_fetch_parent_index(core
, parent
);
2516 pr_debug("%s: clk %s can not be parent of clk %s\n",
2517 __func__
, parent
->name
, core
->name
);
2520 p_rate
= parent
->rate
;
2523 ret
= clk_pm_runtime_get(core
);
2527 /* propagate PRE_RATE_CHANGE notifications */
2528 ret
= __clk_speculate_rates(core
, p_rate
);
2530 /* abort if a driver objects */
2531 if (ret
& NOTIFY_STOP_MASK
)
2534 /* do the re-parent */
2535 ret
= __clk_set_parent(core
, parent
, p_index
);
2537 /* propagate rate an accuracy recalculation accordingly */
2539 __clk_recalc_rates(core
, ABORT_RATE_CHANGE
);
2541 __clk_recalc_rates(core
, POST_RATE_CHANGE
);
2542 __clk_recalc_accuracies(core
);
2546 clk_pm_runtime_put(core
);
2551 int clk_hw_set_parent(struct clk_hw
*hw
, struct clk_hw
*parent
)
2553 return clk_core_set_parent_nolock(hw
->core
, parent
->core
);
2555 EXPORT_SYMBOL_GPL(clk_hw_set_parent
);
2558 * clk_set_parent - switch the parent of a mux clk
2559 * @clk: the mux clk whose input we are switching
2560 * @parent: the new input to clk
2562 * Re-parent clk to use parent as its new input source. If clk is in
2563 * prepared state, the clk will get enabled for the duration of this call. If
2564 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2565 * that, the reparenting is glitchy in hardware, etc), use the
2566 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2568 * After successfully changing clk's parent clk_set_parent will update the
2569 * clk topology, sysfs topology and propagate rate recalculation via
2570 * __clk_recalc_rates.
2572 * Returns 0 on success, -EERROR otherwise.
2574 int clk_set_parent(struct clk
*clk
, struct clk
*parent
)
2583 if (clk
->exclusive_count
)
2584 clk_core_rate_unprotect(clk
->core
);
2586 ret
= clk_core_set_parent_nolock(clk
->core
,
2587 parent
? parent
->core
: NULL
);
2589 if (clk
->exclusive_count
)
2590 clk_core_rate_protect(clk
->core
);
2592 clk_prepare_unlock();
2596 EXPORT_SYMBOL_GPL(clk_set_parent
);
2598 static int clk_core_set_phase_nolock(struct clk_core
*core
, int degrees
)
2602 lockdep_assert_held(&prepare_lock
);
2607 if (clk_core_rate_is_protected(core
))
2610 trace_clk_set_phase(core
, degrees
);
2612 if (core
->ops
->set_phase
) {
2613 ret
= core
->ops
->set_phase(core
->hw
, degrees
);
2615 core
->phase
= degrees
;
2618 trace_clk_set_phase_complete(core
, degrees
);
2624 * clk_set_phase - adjust the phase shift of a clock signal
2625 * @clk: clock signal source
2626 * @degrees: number of degrees the signal is shifted
2628 * Shifts the phase of a clock signal by the specified
2629 * degrees. Returns 0 on success, -EERROR otherwise.
2631 * This function makes no distinction about the input or reference
2632 * signal that we adjust the clock signal phase against. For example
2633 * phase locked-loop clock signal generators we may shift phase with
2634 * respect to feedback clock signal input, but for other cases the
2635 * clock phase may be shifted with respect to some other, unspecified
2638 * Additionally the concept of phase shift does not propagate through
2639 * the clock tree hierarchy, which sets it apart from clock rates and
2640 * clock accuracy. A parent clock phase attribute does not have an
2641 * impact on the phase attribute of a child clock.
2643 int clk_set_phase(struct clk
*clk
, int degrees
)
2650 /* sanity check degrees */
2657 if (clk
->exclusive_count
)
2658 clk_core_rate_unprotect(clk
->core
);
2660 ret
= clk_core_set_phase_nolock(clk
->core
, degrees
);
2662 if (clk
->exclusive_count
)
2663 clk_core_rate_protect(clk
->core
);
2665 clk_prepare_unlock();
2669 EXPORT_SYMBOL_GPL(clk_set_phase
);
2671 static int clk_core_get_phase(struct clk_core
*core
)
2675 lockdep_assert_held(&prepare_lock
);
2676 if (!core
->ops
->get_phase
)
2679 /* Always try to update cached phase if possible */
2680 ret
= core
->ops
->get_phase(core
->hw
);
2688 * clk_get_phase - return the phase shift of a clock signal
2689 * @clk: clock signal source
2691 * Returns the phase shift of a clock node in degrees, otherwise returns
2694 int clk_get_phase(struct clk
*clk
)
2702 ret
= clk_core_get_phase(clk
->core
);
2703 clk_prepare_unlock();
2707 EXPORT_SYMBOL_GPL(clk_get_phase
);
2709 static void clk_core_reset_duty_cycle_nolock(struct clk_core
*core
)
2711 /* Assume a default value of 50% */
2716 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core
*core
);
2718 static int clk_core_update_duty_cycle_nolock(struct clk_core
*core
)
2720 struct clk_duty
*duty
= &core
->duty
;
2723 if (!core
->ops
->get_duty_cycle
)
2724 return clk_core_update_duty_cycle_parent_nolock(core
);
2726 ret
= core
->ops
->get_duty_cycle(core
->hw
, duty
);
2730 /* Don't trust the clock provider too much */
2731 if (duty
->den
== 0 || duty
->num
> duty
->den
) {
2739 clk_core_reset_duty_cycle_nolock(core
);
2743 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core
*core
)
2748 core
->flags
& CLK_DUTY_CYCLE_PARENT
) {
2749 ret
= clk_core_update_duty_cycle_nolock(core
->parent
);
2750 memcpy(&core
->duty
, &core
->parent
->duty
, sizeof(core
->duty
));
2752 clk_core_reset_duty_cycle_nolock(core
);
2758 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core
*core
,
2759 struct clk_duty
*duty
);
2761 static int clk_core_set_duty_cycle_nolock(struct clk_core
*core
,
2762 struct clk_duty
*duty
)
2766 lockdep_assert_held(&prepare_lock
);
2768 if (clk_core_rate_is_protected(core
))
2771 trace_clk_set_duty_cycle(core
, duty
);
2773 if (!core
->ops
->set_duty_cycle
)
2774 return clk_core_set_duty_cycle_parent_nolock(core
, duty
);
2776 ret
= core
->ops
->set_duty_cycle(core
->hw
, duty
);
2778 memcpy(&core
->duty
, duty
, sizeof(*duty
));
2780 trace_clk_set_duty_cycle_complete(core
, duty
);
2785 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core
*core
,
2786 struct clk_duty
*duty
)
2791 core
->flags
& (CLK_DUTY_CYCLE_PARENT
| CLK_SET_RATE_PARENT
)) {
2792 ret
= clk_core_set_duty_cycle_nolock(core
->parent
, duty
);
2793 memcpy(&core
->duty
, &core
->parent
->duty
, sizeof(core
->duty
));
2800 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
2801 * @clk: clock signal source
2802 * @num: numerator of the duty cycle ratio to be applied
2803 * @den: denominator of the duty cycle ratio to be applied
2805 * Apply the duty cycle ratio if the ratio is valid and the clock can
2806 * perform this operation
2808 * Returns (0) on success, a negative errno otherwise.
2810 int clk_set_duty_cycle(struct clk
*clk
, unsigned int num
, unsigned int den
)
2813 struct clk_duty duty
;
2818 /* sanity check the ratio */
2819 if (den
== 0 || num
> den
)
2827 if (clk
->exclusive_count
)
2828 clk_core_rate_unprotect(clk
->core
);
2830 ret
= clk_core_set_duty_cycle_nolock(clk
->core
, &duty
);
2832 if (clk
->exclusive_count
)
2833 clk_core_rate_protect(clk
->core
);
2835 clk_prepare_unlock();
2839 EXPORT_SYMBOL_GPL(clk_set_duty_cycle
);
2841 static int clk_core_get_scaled_duty_cycle(struct clk_core
*core
,
2844 struct clk_duty
*duty
= &core
->duty
;
2849 ret
= clk_core_update_duty_cycle_nolock(core
);
2851 ret
= mult_frac(scale
, duty
->num
, duty
->den
);
2853 clk_prepare_unlock();
2859 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
2860 * @clk: clock signal source
2861 * @scale: scaling factor to be applied to represent the ratio as an integer
2863 * Returns the duty cycle ratio of a clock node multiplied by the provided
2864 * scaling factor, or negative errno on error.
2866 int clk_get_scaled_duty_cycle(struct clk
*clk
, unsigned int scale
)
2871 return clk_core_get_scaled_duty_cycle(clk
->core
, scale
);
2873 EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle
);
2876 * clk_is_match - check if two clk's point to the same hardware clock
2877 * @p: clk compared against q
2878 * @q: clk compared against p
2880 * Returns true if the two struct clk pointers both point to the same hardware
2881 * clock node. Put differently, returns true if struct clk *p and struct clk *q
2882 * share the same struct clk_core object.
2884 * Returns false otherwise. Note that two NULL clks are treated as matching.
2886 bool clk_is_match(const struct clk
*p
, const struct clk
*q
)
2888 /* trivial case: identical struct clk's or both NULL */
2892 /* true if clk->core pointers match. Avoid dereferencing garbage */
2893 if (!IS_ERR_OR_NULL(p
) && !IS_ERR_OR_NULL(q
))
2894 if (p
->core
== q
->core
)
2899 EXPORT_SYMBOL_GPL(clk_is_match
);
2901 /*** debugfs support ***/
2903 #ifdef CONFIG_DEBUG_FS
2904 #include <linux/debugfs.h>
2906 static struct dentry
*rootdir
;
2907 static int inited
= 0;
2908 static DEFINE_MUTEX(clk_debug_lock
);
2909 static HLIST_HEAD(clk_debug_list
);
2911 static struct hlist_head
*orphan_list
[] = {
2916 static void clk_summary_show_one(struct seq_file
*s
, struct clk_core
*c
,
2921 seq_printf(s
, "%*s%-*s %7d %8d %8d %11lu %10lu ",
2923 30 - level
* 3, c
->name
,
2924 c
->enable_count
, c
->prepare_count
, c
->protect_count
,
2925 clk_core_get_rate_recalc(c
),
2926 clk_core_get_accuracy_recalc(c
));
2928 phase
= clk_core_get_phase(c
);
2930 seq_printf(s
, "%5d", phase
);
2932 seq_puts(s
, "-----");
2934 seq_printf(s
, " %6d", clk_core_get_scaled_duty_cycle(c
, 100000));
2936 if (c
->ops
->is_enabled
)
2937 seq_printf(s
, " %9c\n", clk_core_is_enabled(c
) ? 'Y' : 'N');
2938 else if (!c
->ops
->enable
)
2939 seq_printf(s
, " %9c\n", 'Y');
2941 seq_printf(s
, " %9c\n", '?');
2944 static void clk_summary_show_subtree(struct seq_file
*s
, struct clk_core
*c
,
2947 struct clk_core
*child
;
2949 clk_summary_show_one(s
, c
, level
);
2951 hlist_for_each_entry(child
, &c
->children
, child_node
)
2952 clk_summary_show_subtree(s
, child
, level
+ 1);
2955 static int clk_summary_show(struct seq_file
*s
, void *data
)
2958 struct hlist_head
**lists
= (struct hlist_head
**)s
->private;
2960 seq_puts(s
, " enable prepare protect duty hardware\n");
2961 seq_puts(s
, " clock count count count rate accuracy phase cycle enable\n");
2962 seq_puts(s
, "-------------------------------------------------------------------------------------------------------\n");
2966 for (; *lists
; lists
++)
2967 hlist_for_each_entry(c
, *lists
, child_node
)
2968 clk_summary_show_subtree(s
, c
, 0);
2970 clk_prepare_unlock();
2974 DEFINE_SHOW_ATTRIBUTE(clk_summary
);
2976 static void clk_dump_one(struct seq_file
*s
, struct clk_core
*c
, int level
)
2979 unsigned long min_rate
, max_rate
;
2981 clk_core_get_boundaries(c
, &min_rate
, &max_rate
);
2983 /* This should be JSON format, i.e. elements separated with a comma */
2984 seq_printf(s
, "\"%s\": { ", c
->name
);
2985 seq_printf(s
, "\"enable_count\": %d,", c
->enable_count
);
2986 seq_printf(s
, "\"prepare_count\": %d,", c
->prepare_count
);
2987 seq_printf(s
, "\"protect_count\": %d,", c
->protect_count
);
2988 seq_printf(s
, "\"rate\": %lu,", clk_core_get_rate_recalc(c
));
2989 seq_printf(s
, "\"min_rate\": %lu,", min_rate
);
2990 seq_printf(s
, "\"max_rate\": %lu,", max_rate
);
2991 seq_printf(s
, "\"accuracy\": %lu,", clk_core_get_accuracy_recalc(c
));
2992 phase
= clk_core_get_phase(c
);
2994 seq_printf(s
, "\"phase\": %d,", phase
);
2995 seq_printf(s
, "\"duty_cycle\": %u",
2996 clk_core_get_scaled_duty_cycle(c
, 100000));
2999 static void clk_dump_subtree(struct seq_file
*s
, struct clk_core
*c
, int level
)
3001 struct clk_core
*child
;
3003 clk_dump_one(s
, c
, level
);
3005 hlist_for_each_entry(child
, &c
->children
, child_node
) {
3007 clk_dump_subtree(s
, child
, level
+ 1);
3013 static int clk_dump_show(struct seq_file
*s
, void *data
)
3016 bool first_node
= true;
3017 struct hlist_head
**lists
= (struct hlist_head
**)s
->private;
3022 for (; *lists
; lists
++) {
3023 hlist_for_each_entry(c
, *lists
, child_node
) {
3027 clk_dump_subtree(s
, c
, 0);
3031 clk_prepare_unlock();
3036 DEFINE_SHOW_ATTRIBUTE(clk_dump
);
3038 #undef CLOCK_ALLOW_WRITE_DEBUGFS
3039 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3041 * This can be dangerous, therefore don't provide any real compile time
3042 * configuration option for this feature.
3043 * People who want to use this will need to modify the source code directly.
3045 static int clk_rate_set(void *data
, u64 val
)
3047 struct clk_core
*core
= data
;
3051 ret
= clk_core_set_rate_nolock(core
, val
);
3052 clk_prepare_unlock();
3057 #define clk_rate_mode 0644
3059 static int clk_prepare_enable_set(void *data
, u64 val
)
3061 struct clk_core
*core
= data
;
3065 ret
= clk_prepare_enable(core
->hw
->clk
);
3067 clk_disable_unprepare(core
->hw
->clk
);
3072 static int clk_prepare_enable_get(void *data
, u64
*val
)
3074 struct clk_core
*core
= data
;
3076 *val
= core
->enable_count
&& core
->prepare_count
;
3080 DEFINE_DEBUGFS_ATTRIBUTE(clk_prepare_enable_fops
, clk_prepare_enable_get
,
3081 clk_prepare_enable_set
, "%llu\n");
3084 #define clk_rate_set NULL
3085 #define clk_rate_mode 0444
3088 static int clk_rate_get(void *data
, u64
*val
)
3090 struct clk_core
*core
= data
;
3096 DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops
, clk_rate_get
, clk_rate_set
, "%llu\n");
3098 static const struct {
3102 #define ENTRY(f) { f, #f }
3103 ENTRY(CLK_SET_RATE_GATE
),
3104 ENTRY(CLK_SET_PARENT_GATE
),
3105 ENTRY(CLK_SET_RATE_PARENT
),
3106 ENTRY(CLK_IGNORE_UNUSED
),
3107 ENTRY(CLK_GET_RATE_NOCACHE
),
3108 ENTRY(CLK_SET_RATE_NO_REPARENT
),
3109 ENTRY(CLK_GET_ACCURACY_NOCACHE
),
3110 ENTRY(CLK_RECALC_NEW_RATES
),
3111 ENTRY(CLK_SET_RATE_UNGATE
),
3112 ENTRY(CLK_IS_CRITICAL
),
3113 ENTRY(CLK_OPS_PARENT_ENABLE
),
3114 ENTRY(CLK_DUTY_CYCLE_PARENT
),
3118 static int clk_flags_show(struct seq_file
*s
, void *data
)
3120 struct clk_core
*core
= s
->private;
3121 unsigned long flags
= core
->flags
;
3124 for (i
= 0; flags
&& i
< ARRAY_SIZE(clk_flags
); i
++) {
3125 if (flags
& clk_flags
[i
].flag
) {
3126 seq_printf(s
, "%s\n", clk_flags
[i
].name
);
3127 flags
&= ~clk_flags
[i
].flag
;
3132 seq_printf(s
, "0x%lx\n", flags
);
3137 DEFINE_SHOW_ATTRIBUTE(clk_flags
);
3139 static void possible_parent_show(struct seq_file
*s
, struct clk_core
*core
,
3140 unsigned int i
, char terminator
)
3142 struct clk_core
*parent
;
3145 * Go through the following options to fetch a parent's name.
3147 * 1. Fetch the registered parent clock and use its name
3148 * 2. Use the global (fallback) name if specified
3149 * 3. Use the local fw_name if provided
3150 * 4. Fetch parent clock's clock-output-name if DT index was set
3152 * This may still fail in some cases, such as when the parent is
3153 * specified directly via a struct clk_hw pointer, but it isn't
3156 parent
= clk_core_get_parent_by_index(core
, i
);
3158 seq_puts(s
, parent
->name
);
3159 else if (core
->parents
[i
].name
)
3160 seq_puts(s
, core
->parents
[i
].name
);
3161 else if (core
->parents
[i
].fw_name
)
3162 seq_printf(s
, "<%s>(fw)", core
->parents
[i
].fw_name
);
3163 else if (core
->parents
[i
].index
>= 0)
3165 of_clk_get_parent_name(core
->of_node
,
3166 core
->parents
[i
].index
));
3168 seq_puts(s
, "(missing)");
3170 seq_putc(s
, terminator
);
3173 static int possible_parents_show(struct seq_file
*s
, void *data
)
3175 struct clk_core
*core
= s
->private;
3178 for (i
= 0; i
< core
->num_parents
- 1; i
++)
3179 possible_parent_show(s
, core
, i
, ' ');
3181 possible_parent_show(s
, core
, i
, '\n');
3185 DEFINE_SHOW_ATTRIBUTE(possible_parents
);
3187 static int current_parent_show(struct seq_file
*s
, void *data
)
3189 struct clk_core
*core
= s
->private;
3192 seq_printf(s
, "%s\n", core
->parent
->name
);
3196 DEFINE_SHOW_ATTRIBUTE(current_parent
);
3198 static int clk_duty_cycle_show(struct seq_file
*s
, void *data
)
3200 struct clk_core
*core
= s
->private;
3201 struct clk_duty
*duty
= &core
->duty
;
3203 seq_printf(s
, "%u/%u\n", duty
->num
, duty
->den
);
3207 DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle
);
3209 static int clk_min_rate_show(struct seq_file
*s
, void *data
)
3211 struct clk_core
*core
= s
->private;
3212 unsigned long min_rate
, max_rate
;
3215 clk_core_get_boundaries(core
, &min_rate
, &max_rate
);
3216 clk_prepare_unlock();
3217 seq_printf(s
, "%lu\n", min_rate
);
3221 DEFINE_SHOW_ATTRIBUTE(clk_min_rate
);
3223 static int clk_max_rate_show(struct seq_file
*s
, void *data
)
3225 struct clk_core
*core
= s
->private;
3226 unsigned long min_rate
, max_rate
;
3229 clk_core_get_boundaries(core
, &min_rate
, &max_rate
);
3230 clk_prepare_unlock();
3231 seq_printf(s
, "%lu\n", max_rate
);
3235 DEFINE_SHOW_ATTRIBUTE(clk_max_rate
);
3237 static void clk_debug_create_one(struct clk_core
*core
, struct dentry
*pdentry
)
3239 struct dentry
*root
;
3241 if (!core
|| !pdentry
)
3244 root
= debugfs_create_dir(core
->name
, pdentry
);
3245 core
->dentry
= root
;
3247 debugfs_create_file("clk_rate", clk_rate_mode
, root
, core
,
3249 debugfs_create_file("clk_min_rate", 0444, root
, core
, &clk_min_rate_fops
);
3250 debugfs_create_file("clk_max_rate", 0444, root
, core
, &clk_max_rate_fops
);
3251 debugfs_create_ulong("clk_accuracy", 0444, root
, &core
->accuracy
);
3252 debugfs_create_u32("clk_phase", 0444, root
, &core
->phase
);
3253 debugfs_create_file("clk_flags", 0444, root
, core
, &clk_flags_fops
);
3254 debugfs_create_u32("clk_prepare_count", 0444, root
, &core
->prepare_count
);
3255 debugfs_create_u32("clk_enable_count", 0444, root
, &core
->enable_count
);
3256 debugfs_create_u32("clk_protect_count", 0444, root
, &core
->protect_count
);
3257 debugfs_create_u32("clk_notifier_count", 0444, root
, &core
->notifier_count
);
3258 debugfs_create_file("clk_duty_cycle", 0444, root
, core
,
3259 &clk_duty_cycle_fops
);
3260 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3261 debugfs_create_file("clk_prepare_enable", 0644, root
, core
,
3262 &clk_prepare_enable_fops
);
3265 if (core
->num_parents
> 0)
3266 debugfs_create_file("clk_parent", 0444, root
, core
,
3267 ¤t_parent_fops
);
3269 if (core
->num_parents
> 1)
3270 debugfs_create_file("clk_possible_parents", 0444, root
, core
,
3271 &possible_parents_fops
);
3273 if (core
->ops
->debug_init
)
3274 core
->ops
->debug_init(core
->hw
, core
->dentry
);
3278 * clk_debug_register - add a clk node to the debugfs clk directory
3279 * @core: the clk being added to the debugfs clk directory
3281 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
3282 * initialized. Otherwise it bails out early since the debugfs clk directory
3283 * will be created lazily by clk_debug_init as part of a late_initcall.
3285 static void clk_debug_register(struct clk_core
*core
)
3287 mutex_lock(&clk_debug_lock
);
3288 hlist_add_head(&core
->debug_node
, &clk_debug_list
);
3290 clk_debug_create_one(core
, rootdir
);
3291 mutex_unlock(&clk_debug_lock
);
3295 * clk_debug_unregister - remove a clk node from the debugfs clk directory
3296 * @core: the clk being removed from the debugfs clk directory
3298 * Dynamically removes a clk and all its child nodes from the
3299 * debugfs clk directory if clk->dentry points to debugfs created by
3300 * clk_debug_register in __clk_core_init.
3302 static void clk_debug_unregister(struct clk_core
*core
)
3304 mutex_lock(&clk_debug_lock
);
3305 hlist_del_init(&core
->debug_node
);
3306 debugfs_remove_recursive(core
->dentry
);
3307 core
->dentry
= NULL
;
3308 mutex_unlock(&clk_debug_lock
);
3312 * clk_debug_init - lazily populate the debugfs clk directory
3314 * clks are often initialized very early during boot before memory can be
3315 * dynamically allocated and well before debugfs is setup. This function
3316 * populates the debugfs clk directory once at boot-time when we know that
3317 * debugfs is setup. It should only be called once at boot-time, all other clks
3318 * added dynamically will be done so with clk_debug_register.
3320 static int __init
clk_debug_init(void)
3322 struct clk_core
*core
;
3324 rootdir
= debugfs_create_dir("clk", NULL
);
3326 debugfs_create_file("clk_summary", 0444, rootdir
, &all_lists
,
3328 debugfs_create_file("clk_dump", 0444, rootdir
, &all_lists
,
3330 debugfs_create_file("clk_orphan_summary", 0444, rootdir
, &orphan_list
,
3332 debugfs_create_file("clk_orphan_dump", 0444, rootdir
, &orphan_list
,
3335 mutex_lock(&clk_debug_lock
);
3336 hlist_for_each_entry(core
, &clk_debug_list
, debug_node
)
3337 clk_debug_create_one(core
, rootdir
);
3340 mutex_unlock(&clk_debug_lock
);
3344 late_initcall(clk_debug_init
);
3346 static inline void clk_debug_register(struct clk_core
*core
) { }
3347 static inline void clk_debug_unregister(struct clk_core
*core
)
3352 static void clk_core_reparent_orphans_nolock(void)
3354 struct clk_core
*orphan
;
3355 struct hlist_node
*tmp2
;
3358 * walk the list of orphan clocks and reparent any that newly finds a
3361 hlist_for_each_entry_safe(orphan
, tmp2
, &clk_orphan_list
, child_node
) {
3362 struct clk_core
*parent
= __clk_init_parent(orphan
);
3365 * We need to use __clk_set_parent_before() and _after() to
3366 * to properly migrate any prepare/enable count of the orphan
3367 * clock. This is important for CLK_IS_CRITICAL clocks, which
3368 * are enabled during init but might not have a parent yet.
3371 /* update the clk tree topology */
3372 __clk_set_parent_before(orphan
, parent
);
3373 __clk_set_parent_after(orphan
, parent
, NULL
);
3374 __clk_recalc_accuracies(orphan
);
3375 __clk_recalc_rates(orphan
, 0);
3381 * __clk_core_init - initialize the data structures in a struct clk_core
3382 * @core: clk_core being initialized
3384 * Initializes the lists in struct clk_core, queries the hardware for the
3385 * parent and rate and sets them both.
3387 static int __clk_core_init(struct clk_core
*core
)
3390 struct clk_core
*parent
;
3399 ret
= clk_pm_runtime_get(core
);
3403 /* check to see if a clock with this name is already registered */
3404 if (clk_core_lookup(core
->name
)) {
3405 pr_debug("%s: clk %s already initialized\n",
3406 __func__
, core
->name
);
3411 /* check that clk_ops are sane. See Documentation/driver-api/clk.rst */
3412 if (core
->ops
->set_rate
&&
3413 !((core
->ops
->round_rate
|| core
->ops
->determine_rate
) &&
3414 core
->ops
->recalc_rate
)) {
3415 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
3416 __func__
, core
->name
);
3421 if (core
->ops
->set_parent
&& !core
->ops
->get_parent
) {
3422 pr_err("%s: %s must implement .get_parent & .set_parent\n",
3423 __func__
, core
->name
);
3428 if (core
->num_parents
> 1 && !core
->ops
->get_parent
) {
3429 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
3430 __func__
, core
->name
);
3435 if (core
->ops
->set_rate_and_parent
&&
3436 !(core
->ops
->set_parent
&& core
->ops
->set_rate
)) {
3437 pr_err("%s: %s must implement .set_parent & .set_rate\n",
3438 __func__
, core
->name
);
3444 * optional platform-specific magic
3446 * The .init callback is not used by any of the basic clock types, but
3447 * exists for weird hardware that must perform initialization magic for
3448 * CCF to get an accurate view of clock for any other callbacks. It may
3449 * also be used needs to perform dynamic allocations. Such allocation
3450 * must be freed in the terminate() callback.
3451 * This callback shall not be used to initialize the parameters state,
3452 * such as rate, parent, etc ...
3454 * If it exist, this callback should called before any other callback of
3457 if (core
->ops
->init
) {
3458 ret
= core
->ops
->init(core
->hw
);
3463 parent
= core
->parent
= __clk_init_parent(core
);
3466 * Populate core->parent if parent has already been clk_core_init'd. If
3467 * parent has not yet been clk_core_init'd then place clk in the orphan
3468 * list. If clk doesn't have any parents then place it in the root
3471 * Every time a new clk is clk_init'd then we walk the list of orphan
3472 * clocks and re-parent any that are children of the clock currently
3476 hlist_add_head(&core
->child_node
, &parent
->children
);
3477 core
->orphan
= parent
->orphan
;
3478 } else if (!core
->num_parents
) {
3479 hlist_add_head(&core
->child_node
, &clk_root_list
);
3480 core
->orphan
= false;
3482 hlist_add_head(&core
->child_node
, &clk_orphan_list
);
3483 core
->orphan
= true;
3487 * Set clk's accuracy. The preferred method is to use
3488 * .recalc_accuracy. For simple clocks and lazy developers the default
3489 * fallback is to use the parent's accuracy. If a clock doesn't have a
3490 * parent (or is orphaned) then accuracy is set to zero (perfect
3493 if (core
->ops
->recalc_accuracy
)
3494 core
->accuracy
= core
->ops
->recalc_accuracy(core
->hw
,
3495 clk_core_get_accuracy_no_lock(parent
));
3497 core
->accuracy
= parent
->accuracy
;
3502 * Set clk's phase by clk_core_get_phase() caching the phase.
3503 * Since a phase is by definition relative to its parent, just
3504 * query the current clock phase, or just assume it's in phase.
3506 phase
= clk_core_get_phase(core
);
3509 pr_warn("%s: Failed to get phase for clk '%s'\n", __func__
,
3515 * Set clk's duty cycle.
3517 clk_core_update_duty_cycle_nolock(core
);
3520 * Set clk's rate. The preferred method is to use .recalc_rate. For
3521 * simple clocks and lazy developers the default fallback is to use the
3522 * parent's rate. If a clock doesn't have a parent (or is orphaned)
3523 * then rate is set to zero.
3525 if (core
->ops
->recalc_rate
)
3526 rate
= core
->ops
->recalc_rate(core
->hw
,
3527 clk_core_get_rate_nolock(parent
));
3529 rate
= parent
->rate
;
3532 core
->rate
= core
->req_rate
= rate
;
3535 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
3536 * don't get accidentally disabled when walking the orphan tree and
3537 * reparenting clocks
3539 if (core
->flags
& CLK_IS_CRITICAL
) {
3540 unsigned long flags
;
3542 ret
= clk_core_prepare(core
);
3544 pr_warn("%s: critical clk '%s' failed to prepare\n",
3545 __func__
, core
->name
);
3549 flags
= clk_enable_lock();
3550 ret
= clk_core_enable(core
);
3551 clk_enable_unlock(flags
);
3553 pr_warn("%s: critical clk '%s' failed to enable\n",
3554 __func__
, core
->name
);
3555 clk_core_unprepare(core
);
3560 clk_core_reparent_orphans_nolock();
3563 kref_init(&core
->ref
);
3565 clk_pm_runtime_put(core
);
3568 hlist_del_init(&core
->child_node
);
3570 clk_prepare_unlock();
3573 clk_debug_register(core
);
3579 * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core
3580 * @core: clk to add consumer to
3581 * @clk: consumer to link to a clk
3583 static void clk_core_link_consumer(struct clk_core
*core
, struct clk
*clk
)
3586 hlist_add_head(&clk
->clks_node
, &core
->clks
);
3587 clk_prepare_unlock();
3591 * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core
3592 * @clk: consumer to unlink
3594 static void clk_core_unlink_consumer(struct clk
*clk
)
3596 lockdep_assert_held(&prepare_lock
);
3597 hlist_del(&clk
->clks_node
);
3601 * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core
3602 * @core: clk to allocate a consumer for
3603 * @dev_id: string describing device name
3604 * @con_id: connection ID string on device
3606 * Returns: clk consumer left unlinked from the consumer list
3608 static struct clk
*alloc_clk(struct clk_core
*core
, const char *dev_id
,
3613 clk
= kzalloc(sizeof(*clk
), GFP_KERNEL
);
3615 return ERR_PTR(-ENOMEM
);
3618 clk
->dev_id
= dev_id
;
3619 clk
->con_id
= kstrdup_const(con_id
, GFP_KERNEL
);
3620 clk
->max_rate
= ULONG_MAX
;
3626 * free_clk - Free a clk consumer
3627 * @clk: clk consumer to free
3629 * Note, this assumes the clk has been unlinked from the clk_core consumer
3632 static void free_clk(struct clk
*clk
)
3634 kfree_const(clk
->con_id
);
3639 * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given
3641 * @dev: clk consumer device
3642 * @hw: clk_hw associated with the clk being consumed
3643 * @dev_id: string describing device name
3644 * @con_id: connection ID string on device
3646 * This is the main function used to create a clk pointer for use by clk
3647 * consumers. It connects a consumer to the clk_core and clk_hw structures
3648 * used by the framework and clk provider respectively.
3650 struct clk
*clk_hw_create_clk(struct device
*dev
, struct clk_hw
*hw
,
3651 const char *dev_id
, const char *con_id
)
3654 struct clk_core
*core
;
3656 /* This is to allow this function to be chained to others */
3657 if (IS_ERR_OR_NULL(hw
))
3658 return ERR_CAST(hw
);
3661 clk
= alloc_clk(core
, dev_id
, con_id
);
3666 if (!try_module_get(core
->owner
)) {
3668 return ERR_PTR(-ENOENT
);
3671 kref_get(&core
->ref
);
3672 clk_core_link_consumer(core
, clk
);
3677 static int clk_cpy_name(const char **dst_p
, const char *src
, bool must_exist
)
3687 *dst_p
= dst
= kstrdup_const(src
, GFP_KERNEL
);
3694 static int clk_core_populate_parent_map(struct clk_core
*core
,
3695 const struct clk_init_data
*init
)
3697 u8 num_parents
= init
->num_parents
;
3698 const char * const *parent_names
= init
->parent_names
;
3699 const struct clk_hw
**parent_hws
= init
->parent_hws
;
3700 const struct clk_parent_data
*parent_data
= init
->parent_data
;
3702 struct clk_parent_map
*parents
, *parent
;
3708 * Avoid unnecessary string look-ups of clk_core's possible parents by
3709 * having a cache of names/clk_hw pointers to clk_core pointers.
3711 parents
= kcalloc(num_parents
, sizeof(*parents
), GFP_KERNEL
);
3712 core
->parents
= parents
;
3716 /* Copy everything over because it might be __initdata */
3717 for (i
= 0, parent
= parents
; i
< num_parents
; i
++, parent
++) {
3720 /* throw a WARN if any entries are NULL */
3721 WARN(!parent_names
[i
],
3722 "%s: invalid NULL in %s's .parent_names\n",
3723 __func__
, core
->name
);
3724 ret
= clk_cpy_name(&parent
->name
, parent_names
[i
],
3726 } else if (parent_data
) {
3727 parent
->hw
= parent_data
[i
].hw
;
3728 parent
->index
= parent_data
[i
].index
;
3729 ret
= clk_cpy_name(&parent
->fw_name
,
3730 parent_data
[i
].fw_name
, false);
3732 ret
= clk_cpy_name(&parent
->name
,
3733 parent_data
[i
].name
,
3735 } else if (parent_hws
) {
3736 parent
->hw
= parent_hws
[i
];
3739 WARN(1, "Must specify parents if num_parents > 0\n");
3744 kfree_const(parents
[i
].name
);
3745 kfree_const(parents
[i
].fw_name
);
3756 static void clk_core_free_parent_map(struct clk_core
*core
)
3758 int i
= core
->num_parents
;
3760 if (!core
->num_parents
)
3764 kfree_const(core
->parents
[i
].name
);
3765 kfree_const(core
->parents
[i
].fw_name
);
3768 kfree(core
->parents
);
3772 __clk_register(struct device
*dev
, struct device_node
*np
, struct clk_hw
*hw
)
3775 struct clk_core
*core
;
3776 const struct clk_init_data
*init
= hw
->init
;
3779 * The init data is not supposed to be used outside of registration path.
3780 * Set it to NULL so that provider drivers can't use it either and so that
3781 * we catch use of hw->init early on in the core.
3785 core
= kzalloc(sizeof(*core
), GFP_KERNEL
);
3791 core
->name
= kstrdup_const(init
->name
, GFP_KERNEL
);
3797 if (WARN_ON(!init
->ops
)) {
3801 core
->ops
= init
->ops
;
3803 if (dev
&& pm_runtime_enabled(dev
))
3804 core
->rpm_enabled
= true;
3807 if (dev
&& dev
->driver
)
3808 core
->owner
= dev
->driver
->owner
;
3810 core
->flags
= init
->flags
;
3811 core
->num_parents
= init
->num_parents
;
3813 core
->max_rate
= ULONG_MAX
;
3816 ret
= clk_core_populate_parent_map(core
, init
);
3820 INIT_HLIST_HEAD(&core
->clks
);
3823 * Don't call clk_hw_create_clk() here because that would pin the
3824 * provider module to itself and prevent it from ever being removed.
3826 hw
->clk
= alloc_clk(core
, NULL
, NULL
);
3827 if (IS_ERR(hw
->clk
)) {
3828 ret
= PTR_ERR(hw
->clk
);
3829 goto fail_create_clk
;
3832 clk_core_link_consumer(hw
->core
, hw
->clk
);
3834 ret
= __clk_core_init(core
);
3839 clk_core_unlink_consumer(hw
->clk
);
3840 clk_prepare_unlock();
3846 clk_core_free_parent_map(core
);
3849 kfree_const(core
->name
);
3853 return ERR_PTR(ret
);
3857 * dev_or_parent_of_node() - Get device node of @dev or @dev's parent
3858 * @dev: Device to get device node of
3860 * Return: device node pointer of @dev, or the device node pointer of
3861 * @dev->parent if dev doesn't have a device node, or NULL if neither
3862 * @dev or @dev->parent have a device node.
3864 static struct device_node
*dev_or_parent_of_node(struct device
*dev
)
3866 struct device_node
*np
;
3871 np
= dev_of_node(dev
);
3873 np
= dev_of_node(dev
->parent
);
3879 * clk_register - allocate a new clock, register it and return an opaque cookie
3880 * @dev: device that is registering this clock
3881 * @hw: link to hardware-specific clock data
3883 * clk_register is the *deprecated* interface for populating the clock tree with
3884 * new clock nodes. Use clk_hw_register() instead.
3886 * Returns: a pointer to the newly allocated struct clk which
3887 * cannot be dereferenced by driver code but may be used in conjunction with the
3888 * rest of the clock API. In the event of an error clk_register will return an
3889 * error code; drivers must test for an error code after calling clk_register.
3891 struct clk
*clk_register(struct device
*dev
, struct clk_hw
*hw
)
3893 return __clk_register(dev
, dev_or_parent_of_node(dev
), hw
);
3895 EXPORT_SYMBOL_GPL(clk_register
);
3898 * clk_hw_register - register a clk_hw and return an error code
3899 * @dev: device that is registering this clock
3900 * @hw: link to hardware-specific clock data
3902 * clk_hw_register is the primary interface for populating the clock tree with
3903 * new clock nodes. It returns an integer equal to zero indicating success or
3904 * less than zero indicating failure. Drivers must test for an error code after
3905 * calling clk_hw_register().
3907 int clk_hw_register(struct device
*dev
, struct clk_hw
*hw
)
3909 return PTR_ERR_OR_ZERO(__clk_register(dev
, dev_or_parent_of_node(dev
),
3912 EXPORT_SYMBOL_GPL(clk_hw_register
);
3915 * of_clk_hw_register - register a clk_hw and return an error code
3916 * @node: device_node of device that is registering this clock
3917 * @hw: link to hardware-specific clock data
3919 * of_clk_hw_register() is the primary interface for populating the clock tree
3920 * with new clock nodes when a struct device is not available, but a struct
3921 * device_node is. It returns an integer equal to zero indicating success or
3922 * less than zero indicating failure. Drivers must test for an error code after
3923 * calling of_clk_hw_register().
3925 int of_clk_hw_register(struct device_node
*node
, struct clk_hw
*hw
)
3927 return PTR_ERR_OR_ZERO(__clk_register(NULL
, node
, hw
));
3929 EXPORT_SYMBOL_GPL(of_clk_hw_register
);
3931 /* Free memory allocated for a clock. */
3932 static void __clk_release(struct kref
*ref
)
3934 struct clk_core
*core
= container_of(ref
, struct clk_core
, ref
);
3936 lockdep_assert_held(&prepare_lock
);
3938 clk_core_free_parent_map(core
);
3939 kfree_const(core
->name
);
3944 * Empty clk_ops for unregistered clocks. These are used temporarily
3945 * after clk_unregister() was called on a clock and until last clock
3946 * consumer calls clk_put() and the struct clk object is freed.
3948 static int clk_nodrv_prepare_enable(struct clk_hw
*hw
)
3953 static void clk_nodrv_disable_unprepare(struct clk_hw
*hw
)
3958 static int clk_nodrv_set_rate(struct clk_hw
*hw
, unsigned long rate
,
3959 unsigned long parent_rate
)
3964 static int clk_nodrv_set_parent(struct clk_hw
*hw
, u8 index
)
3969 static const struct clk_ops clk_nodrv_ops
= {
3970 .enable
= clk_nodrv_prepare_enable
,
3971 .disable
= clk_nodrv_disable_unprepare
,
3972 .prepare
= clk_nodrv_prepare_enable
,
3973 .unprepare
= clk_nodrv_disable_unprepare
,
3974 .set_rate
= clk_nodrv_set_rate
,
3975 .set_parent
= clk_nodrv_set_parent
,
3978 static void clk_core_evict_parent_cache_subtree(struct clk_core
*root
,
3979 struct clk_core
*target
)
3982 struct clk_core
*child
;
3984 for (i
= 0; i
< root
->num_parents
; i
++)
3985 if (root
->parents
[i
].core
== target
)
3986 root
->parents
[i
].core
= NULL
;
3988 hlist_for_each_entry(child
, &root
->children
, child_node
)
3989 clk_core_evict_parent_cache_subtree(child
, target
);
3992 /* Remove this clk from all parent caches */
3993 static void clk_core_evict_parent_cache(struct clk_core
*core
)
3995 struct hlist_head
**lists
;
3996 struct clk_core
*root
;
3998 lockdep_assert_held(&prepare_lock
);
4000 for (lists
= all_lists
; *lists
; lists
++)
4001 hlist_for_each_entry(root
, *lists
, child_node
)
4002 clk_core_evict_parent_cache_subtree(root
, core
);
4007 * clk_unregister - unregister a currently registered clock
4008 * @clk: clock to unregister
4010 void clk_unregister(struct clk
*clk
)
4012 unsigned long flags
;
4013 const struct clk_ops
*ops
;
4015 if (!clk
|| WARN_ON_ONCE(IS_ERR(clk
)))
4018 clk_debug_unregister(clk
->core
);
4022 ops
= clk
->core
->ops
;
4023 if (ops
== &clk_nodrv_ops
) {
4024 pr_err("%s: unregistered clock: %s\n", __func__
,
4029 * Assign empty clock ops for consumers that might still hold
4030 * a reference to this clock.
4032 flags
= clk_enable_lock();
4033 clk
->core
->ops
= &clk_nodrv_ops
;
4034 clk_enable_unlock(flags
);
4037 ops
->terminate(clk
->core
->hw
);
4039 if (!hlist_empty(&clk
->core
->children
)) {
4040 struct clk_core
*child
;
4041 struct hlist_node
*t
;
4043 /* Reparent all children to the orphan list. */
4044 hlist_for_each_entry_safe(child
, t
, &clk
->core
->children
,
4046 clk_core_set_parent_nolock(child
, NULL
);
4049 clk_core_evict_parent_cache(clk
->core
);
4051 hlist_del_init(&clk
->core
->child_node
);
4053 if (clk
->core
->prepare_count
)
4054 pr_warn("%s: unregistering prepared clock: %s\n",
4055 __func__
, clk
->core
->name
);
4057 if (clk
->core
->protect_count
)
4058 pr_warn("%s: unregistering protected clock: %s\n",
4059 __func__
, clk
->core
->name
);
4061 kref_put(&clk
->core
->ref
, __clk_release
);
4064 clk_prepare_unlock();
4066 EXPORT_SYMBOL_GPL(clk_unregister
);
4069 * clk_hw_unregister - unregister a currently registered clk_hw
4070 * @hw: hardware-specific clock data to unregister
4072 void clk_hw_unregister(struct clk_hw
*hw
)
4074 clk_unregister(hw
->clk
);
4076 EXPORT_SYMBOL_GPL(clk_hw_unregister
);
4078 static void devm_clk_release(struct device
*dev
, void *res
)
4080 clk_unregister(*(struct clk
**)res
);
4083 static void devm_clk_hw_release(struct device
*dev
, void *res
)
4085 clk_hw_unregister(*(struct clk_hw
**)res
);
4089 * devm_clk_register - resource managed clk_register()
4090 * @dev: device that is registering this clock
4091 * @hw: link to hardware-specific clock data
4093 * Managed clk_register(). This function is *deprecated*, use devm_clk_hw_register() instead.
4095 * Clocks returned from this function are automatically clk_unregister()ed on
4096 * driver detach. See clk_register() for more information.
4098 struct clk
*devm_clk_register(struct device
*dev
, struct clk_hw
*hw
)
4103 clkp
= devres_alloc(devm_clk_release
, sizeof(*clkp
), GFP_KERNEL
);
4105 return ERR_PTR(-ENOMEM
);
4107 clk
= clk_register(dev
, hw
);
4110 devres_add(dev
, clkp
);
4117 EXPORT_SYMBOL_GPL(devm_clk_register
);
4120 * devm_clk_hw_register - resource managed clk_hw_register()
4121 * @dev: device that is registering this clock
4122 * @hw: link to hardware-specific clock data
4124 * Managed clk_hw_register(). Clocks registered by this function are
4125 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
4126 * for more information.
4128 int devm_clk_hw_register(struct device
*dev
, struct clk_hw
*hw
)
4130 struct clk_hw
**hwp
;
4133 hwp
= devres_alloc(devm_clk_hw_release
, sizeof(*hwp
), GFP_KERNEL
);
4137 ret
= clk_hw_register(dev
, hw
);
4140 devres_add(dev
, hwp
);
4147 EXPORT_SYMBOL_GPL(devm_clk_hw_register
);
4149 static int devm_clk_match(struct device
*dev
, void *res
, void *data
)
4151 struct clk
*c
= res
;
4157 static int devm_clk_hw_match(struct device
*dev
, void *res
, void *data
)
4159 struct clk_hw
*hw
= res
;
4167 * devm_clk_unregister - resource managed clk_unregister()
4168 * @dev: device that is unregistering the clock data
4169 * @clk: clock to unregister
4171 * Deallocate a clock allocated with devm_clk_register(). Normally
4172 * this function will not need to be called and the resource management
4173 * code will ensure that the resource is freed.
4175 void devm_clk_unregister(struct device
*dev
, struct clk
*clk
)
4177 WARN_ON(devres_release(dev
, devm_clk_release
, devm_clk_match
, clk
));
4179 EXPORT_SYMBOL_GPL(devm_clk_unregister
);
4182 * devm_clk_hw_unregister - resource managed clk_hw_unregister()
4183 * @dev: device that is unregistering the hardware-specific clock data
4184 * @hw: link to hardware-specific clock data
4186 * Unregister a clk_hw registered with devm_clk_hw_register(). Normally
4187 * this function will not need to be called and the resource management
4188 * code will ensure that the resource is freed.
4190 void devm_clk_hw_unregister(struct device
*dev
, struct clk_hw
*hw
)
4192 WARN_ON(devres_release(dev
, devm_clk_hw_release
, devm_clk_hw_match
,
4195 EXPORT_SYMBOL_GPL(devm_clk_hw_unregister
);
4201 void __clk_put(struct clk
*clk
)
4203 struct module
*owner
;
4205 if (!clk
|| WARN_ON_ONCE(IS_ERR(clk
)))
4211 * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
4212 * given user should be balanced with calls to clk_rate_exclusive_put()
4213 * and by that same consumer
4215 if (WARN_ON(clk
->exclusive_count
)) {
4216 /* We voiced our concern, let's sanitize the situation */
4217 clk
->core
->protect_count
-= (clk
->exclusive_count
- 1);
4218 clk_core_rate_unprotect(clk
->core
);
4219 clk
->exclusive_count
= 0;
4222 hlist_del(&clk
->clks_node
);
4223 if (clk
->min_rate
> clk
->core
->req_rate
||
4224 clk
->max_rate
< clk
->core
->req_rate
)
4225 clk_core_set_rate_nolock(clk
->core
, clk
->core
->req_rate
);
4227 owner
= clk
->core
->owner
;
4228 kref_put(&clk
->core
->ref
, __clk_release
);
4230 clk_prepare_unlock();
4237 /*** clk rate change notifiers ***/
4240 * clk_notifier_register - add a clk rate change notifier
4241 * @clk: struct clk * to watch
4242 * @nb: struct notifier_block * with callback info
4244 * Request notification when clk's rate changes. This uses an SRCU
4245 * notifier because we want it to block and notifier unregistrations are
4246 * uncommon. The callbacks associated with the notifier must not
4247 * re-enter into the clk framework by calling any top-level clk APIs;
4248 * this will cause a nested prepare_lock mutex.
4250 * In all notification cases (pre, post and abort rate change) the original
4251 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
4252 * and the new frequency is passed via struct clk_notifier_data.new_rate.
4254 * clk_notifier_register() must be called from non-atomic context.
4255 * Returns -EINVAL if called with null arguments, -ENOMEM upon
4256 * allocation failure; otherwise, passes along the return value of
4257 * srcu_notifier_chain_register().
4259 int clk_notifier_register(struct clk
*clk
, struct notifier_block
*nb
)
4261 struct clk_notifier
*cn
;
4269 /* search the list of notifiers for this clk */
4270 list_for_each_entry(cn
, &clk_notifier_list
, node
)
4274 /* if clk wasn't in the notifier list, allocate new clk_notifier */
4275 if (cn
->clk
!= clk
) {
4276 cn
= kzalloc(sizeof(*cn
), GFP_KERNEL
);
4281 srcu_init_notifier_head(&cn
->notifier_head
);
4283 list_add(&cn
->node
, &clk_notifier_list
);
4286 ret
= srcu_notifier_chain_register(&cn
->notifier_head
, nb
);
4288 clk
->core
->notifier_count
++;
4291 clk_prepare_unlock();
4295 EXPORT_SYMBOL_GPL(clk_notifier_register
);
4298 * clk_notifier_unregister - remove a clk rate change notifier
4299 * @clk: struct clk *
4300 * @nb: struct notifier_block * with callback info
4302 * Request no further notification for changes to 'clk' and frees memory
4303 * allocated in clk_notifier_register.
4305 * Returns -EINVAL if called with null arguments; otherwise, passes
4306 * along the return value of srcu_notifier_chain_unregister().
4308 int clk_notifier_unregister(struct clk
*clk
, struct notifier_block
*nb
)
4310 struct clk_notifier
*cn
= NULL
;
4318 list_for_each_entry(cn
, &clk_notifier_list
, node
)
4322 if (cn
->clk
== clk
) {
4323 ret
= srcu_notifier_chain_unregister(&cn
->notifier_head
, nb
);
4325 clk
->core
->notifier_count
--;
4327 /* XXX the notifier code should handle this better */
4328 if (!cn
->notifier_head
.head
) {
4329 srcu_cleanup_notifier_head(&cn
->notifier_head
);
4330 list_del(&cn
->node
);
4338 clk_prepare_unlock();
4342 EXPORT_SYMBOL_GPL(clk_notifier_unregister
);
4345 static void clk_core_reparent_orphans(void)
4348 clk_core_reparent_orphans_nolock();
4349 clk_prepare_unlock();
4353 * struct of_clk_provider - Clock provider registration structure
4354 * @link: Entry in global list of clock providers
4355 * @node: Pointer to device tree node of clock provider
4356 * @get: Get clock callback. Returns NULL or a struct clk for the
4357 * given clock specifier
4358 * @get_hw: Get clk_hw callback. Returns NULL, ERR_PTR or a
4359 * struct clk_hw for the given clock specifier
4360 * @data: context pointer to be passed into @get callback
4362 struct of_clk_provider
{
4363 struct list_head link
;
4365 struct device_node
*node
;
4366 struct clk
*(*get
)(struct of_phandle_args
*clkspec
, void *data
);
4367 struct clk_hw
*(*get_hw
)(struct of_phandle_args
*clkspec
, void *data
);
4371 extern struct of_device_id __clk_of_table
;
4372 static const struct of_device_id __clk_of_table_sentinel
4373 __used
__section("__clk_of_table_end");
4375 static LIST_HEAD(of_clk_providers
);
4376 static DEFINE_MUTEX(of_clk_mutex
);
4378 struct clk
*of_clk_src_simple_get(struct of_phandle_args
*clkspec
,
4383 EXPORT_SYMBOL_GPL(of_clk_src_simple_get
);
4385 struct clk_hw
*of_clk_hw_simple_get(struct of_phandle_args
*clkspec
, void *data
)
4389 EXPORT_SYMBOL_GPL(of_clk_hw_simple_get
);
4391 struct clk
*of_clk_src_onecell_get(struct of_phandle_args
*clkspec
, void *data
)
4393 struct clk_onecell_data
*clk_data
= data
;
4394 unsigned int idx
= clkspec
->args
[0];
4396 if (idx
>= clk_data
->clk_num
) {
4397 pr_err("%s: invalid clock index %u\n", __func__
, idx
);
4398 return ERR_PTR(-EINVAL
);
4401 return clk_data
->clks
[idx
];
4403 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get
);
4406 of_clk_hw_onecell_get(struct of_phandle_args
*clkspec
, void *data
)
4408 struct clk_hw_onecell_data
*hw_data
= data
;
4409 unsigned int idx
= clkspec
->args
[0];
4411 if (idx
>= hw_data
->num
) {
4412 pr_err("%s: invalid index %u\n", __func__
, idx
);
4413 return ERR_PTR(-EINVAL
);
4416 return hw_data
->hws
[idx
];
4418 EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get
);
4421 * of_clk_add_provider() - Register a clock provider for a node
4422 * @np: Device node pointer associated with clock provider
4423 * @clk_src_get: callback for decoding clock
4424 * @data: context pointer for @clk_src_get callback.
4426 * This function is *deprecated*. Use of_clk_add_hw_provider() instead.
4428 int of_clk_add_provider(struct device_node
*np
,
4429 struct clk
*(*clk_src_get
)(struct of_phandle_args
*clkspec
,
4433 struct of_clk_provider
*cp
;
4436 cp
= kzalloc(sizeof(*cp
), GFP_KERNEL
);
4440 cp
->node
= of_node_get(np
);
4442 cp
->get
= clk_src_get
;
4444 mutex_lock(&of_clk_mutex
);
4445 list_add(&cp
->link
, &of_clk_providers
);
4446 mutex_unlock(&of_clk_mutex
);
4447 pr_debug("Added clock from %pOF\n", np
);
4449 clk_core_reparent_orphans();
4451 ret
= of_clk_set_defaults(np
, true);
4453 of_clk_del_provider(np
);
4457 EXPORT_SYMBOL_GPL(of_clk_add_provider
);
4460 * of_clk_add_hw_provider() - Register a clock provider for a node
4461 * @np: Device node pointer associated with clock provider
4462 * @get: callback for decoding clk_hw
4463 * @data: context pointer for @get callback.
4465 int of_clk_add_hw_provider(struct device_node
*np
,
4466 struct clk_hw
*(*get
)(struct of_phandle_args
*clkspec
,
4470 struct of_clk_provider
*cp
;
4473 cp
= kzalloc(sizeof(*cp
), GFP_KERNEL
);
4477 cp
->node
= of_node_get(np
);
4481 mutex_lock(&of_clk_mutex
);
4482 list_add(&cp
->link
, &of_clk_providers
);
4483 mutex_unlock(&of_clk_mutex
);
4484 pr_debug("Added clk_hw provider from %pOF\n", np
);
4486 clk_core_reparent_orphans();
4488 ret
= of_clk_set_defaults(np
, true);
4490 of_clk_del_provider(np
);
4494 EXPORT_SYMBOL_GPL(of_clk_add_hw_provider
);
4496 static void devm_of_clk_release_provider(struct device
*dev
, void *res
)
4498 of_clk_del_provider(*(struct device_node
**)res
);
4502 * We allow a child device to use its parent device as the clock provider node
4503 * for cases like MFD sub-devices where the child device driver wants to use
4504 * devm_*() APIs but not list the device in DT as a sub-node.
4506 static struct device_node
*get_clk_provider_node(struct device
*dev
)
4508 struct device_node
*np
, *parent_np
;
4511 parent_np
= dev
->parent
? dev
->parent
->of_node
: NULL
;
4513 if (!of_find_property(np
, "#clock-cells", NULL
))
4514 if (of_find_property(parent_np
, "#clock-cells", NULL
))
4521 * devm_of_clk_add_hw_provider() - Managed clk provider node registration
4522 * @dev: Device acting as the clock provider (used for DT node and lifetime)
4523 * @get: callback for decoding clk_hw
4524 * @data: context pointer for @get callback
4526 * Registers clock provider for given device's node. If the device has no DT
4527 * node or if the device node lacks of clock provider information (#clock-cells)
4528 * then the parent device's node is scanned for this information. If parent node
4529 * has the #clock-cells then it is used in registration. Provider is
4530 * automatically released at device exit.
4532 * Return: 0 on success or an errno on failure.
4534 int devm_of_clk_add_hw_provider(struct device
*dev
,
4535 struct clk_hw
*(*get
)(struct of_phandle_args
*clkspec
,
4539 struct device_node
**ptr
, *np
;
4542 ptr
= devres_alloc(devm_of_clk_release_provider
, sizeof(*ptr
),
4547 np
= get_clk_provider_node(dev
);
4548 ret
= of_clk_add_hw_provider(np
, get
, data
);
4551 devres_add(dev
, ptr
);
4558 EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider
);
4561 * of_clk_del_provider() - Remove a previously registered clock provider
4562 * @np: Device node pointer associated with clock provider
4564 void of_clk_del_provider(struct device_node
*np
)
4566 struct of_clk_provider
*cp
;
4568 mutex_lock(&of_clk_mutex
);
4569 list_for_each_entry(cp
, &of_clk_providers
, link
) {
4570 if (cp
->node
== np
) {
4571 list_del(&cp
->link
);
4572 of_node_put(cp
->node
);
4577 mutex_unlock(&of_clk_mutex
);
4579 EXPORT_SYMBOL_GPL(of_clk_del_provider
);
4581 static int devm_clk_provider_match(struct device
*dev
, void *res
, void *data
)
4583 struct device_node
**np
= res
;
4585 if (WARN_ON(!np
|| !*np
))
4592 * devm_of_clk_del_provider() - Remove clock provider registered using devm
4593 * @dev: Device to whose lifetime the clock provider was bound
4595 void devm_of_clk_del_provider(struct device
*dev
)
4598 struct device_node
*np
= get_clk_provider_node(dev
);
4600 ret
= devres_release(dev
, devm_of_clk_release_provider
,
4601 devm_clk_provider_match
, np
);
4605 EXPORT_SYMBOL(devm_of_clk_del_provider
);
4608 * of_parse_clkspec() - Parse a DT clock specifier for a given device node
4609 * @np: device node to parse clock specifier from
4610 * @index: index of phandle to parse clock out of. If index < 0, @name is used
4611 * @name: clock name to find and parse. If name is NULL, the index is used
4612 * @out_args: Result of parsing the clock specifier
4614 * Parses a device node's "clocks" and "clock-names" properties to find the
4615 * phandle and cells for the index or name that is desired. The resulting clock
4616 * specifier is placed into @out_args, or an errno is returned when there's a
4617 * parsing error. The @index argument is ignored if @name is non-NULL.
4621 * phandle1: clock-controller@1 {
4622 * #clock-cells = <2>;
4625 * phandle2: clock-controller@2 {
4626 * #clock-cells = <1>;
4629 * clock-consumer@3 {
4630 * clocks = <&phandle1 1 2 &phandle2 3>;
4631 * clock-names = "name1", "name2";
4634 * To get a device_node for `clock-controller@2' node you may call this
4635 * function a few different ways:
4637 * of_parse_clkspec(clock-consumer@3, -1, "name2", &args);
4638 * of_parse_clkspec(clock-consumer@3, 1, NULL, &args);
4639 * of_parse_clkspec(clock-consumer@3, 1, "name2", &args);
4641 * Return: 0 upon successfully parsing the clock specifier. Otherwise, -ENOENT
4642 * if @name is NULL or -EINVAL if @name is non-NULL and it can't be found in
4643 * the "clock-names" property of @np.
4645 static int of_parse_clkspec(const struct device_node
*np
, int index
,
4646 const char *name
, struct of_phandle_args
*out_args
)
4650 /* Walk up the tree of devices looking for a clock property that matches */
4653 * For named clocks, first look up the name in the
4654 * "clock-names" property. If it cannot be found, then index
4655 * will be an error code and of_parse_phandle_with_args() will
4659 index
= of_property_match_string(np
, "clock-names", name
);
4660 ret
= of_parse_phandle_with_args(np
, "clocks", "#clock-cells",
4664 if (name
&& index
>= 0)
4668 * No matching clock found on this node. If the parent node
4669 * has a "clock-ranges" property, then we can try one of its
4673 if (np
&& !of_get_property(np
, "clock-ranges", NULL
))
4681 static struct clk_hw
*
4682 __of_clk_get_hw_from_provider(struct of_clk_provider
*provider
,
4683 struct of_phandle_args
*clkspec
)
4687 if (provider
->get_hw
)
4688 return provider
->get_hw(clkspec
, provider
->data
);
4690 clk
= provider
->get(clkspec
, provider
->data
);
4692 return ERR_CAST(clk
);
4693 return __clk_get_hw(clk
);
4696 static struct clk_hw
*
4697 of_clk_get_hw_from_clkspec(struct of_phandle_args
*clkspec
)
4699 struct of_clk_provider
*provider
;
4700 struct clk_hw
*hw
= ERR_PTR(-EPROBE_DEFER
);
4703 return ERR_PTR(-EINVAL
);
4705 mutex_lock(&of_clk_mutex
);
4706 list_for_each_entry(provider
, &of_clk_providers
, link
) {
4707 if (provider
->node
== clkspec
->np
) {
4708 hw
= __of_clk_get_hw_from_provider(provider
, clkspec
);
4713 mutex_unlock(&of_clk_mutex
);
4719 * of_clk_get_from_provider() - Lookup a clock from a clock provider
4720 * @clkspec: pointer to a clock specifier data structure
4722 * This function looks up a struct clk from the registered list of clock
4723 * providers, an input is a clock specifier data structure as returned
4724 * from the of_parse_phandle_with_args() function call.
4726 struct clk
*of_clk_get_from_provider(struct of_phandle_args
*clkspec
)
4728 struct clk_hw
*hw
= of_clk_get_hw_from_clkspec(clkspec
);
4730 return clk_hw_create_clk(NULL
, hw
, NULL
, __func__
);
4732 EXPORT_SYMBOL_GPL(of_clk_get_from_provider
);
4734 struct clk_hw
*of_clk_get_hw(struct device_node
*np
, int index
,
4739 struct of_phandle_args clkspec
;
4741 ret
= of_parse_clkspec(np
, index
, con_id
, &clkspec
);
4743 return ERR_PTR(ret
);
4745 hw
= of_clk_get_hw_from_clkspec(&clkspec
);
4746 of_node_put(clkspec
.np
);
4751 static struct clk
*__of_clk_get(struct device_node
*np
,
4752 int index
, const char *dev_id
,
4755 struct clk_hw
*hw
= of_clk_get_hw(np
, index
, con_id
);
4757 return clk_hw_create_clk(NULL
, hw
, dev_id
, con_id
);
4760 struct clk
*of_clk_get(struct device_node
*np
, int index
)
4762 return __of_clk_get(np
, index
, np
->full_name
, NULL
);
4764 EXPORT_SYMBOL(of_clk_get
);
4767 * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
4768 * @np: pointer to clock consumer node
4769 * @name: name of consumer's clock input, or NULL for the first clock reference
4771 * This function parses the clocks and clock-names properties,
4772 * and uses them to look up the struct clk from the registered list of clock
4775 struct clk
*of_clk_get_by_name(struct device_node
*np
, const char *name
)
4778 return ERR_PTR(-ENOENT
);
4780 return __of_clk_get(np
, 0, np
->full_name
, name
);
4782 EXPORT_SYMBOL(of_clk_get_by_name
);
4785 * of_clk_get_parent_count() - Count the number of clocks a device node has
4786 * @np: device node to count
4788 * Returns: The number of clocks that are possible parents of this node
4790 unsigned int of_clk_get_parent_count(const struct device_node
*np
)
4794 count
= of_count_phandle_with_args(np
, "clocks", "#clock-cells");
4800 EXPORT_SYMBOL_GPL(of_clk_get_parent_count
);
4802 const char *of_clk_get_parent_name(const struct device_node
*np
, int index
)
4804 struct of_phandle_args clkspec
;
4805 struct property
*prop
;
4806 const char *clk_name
;
4813 rc
= of_parse_phandle_with_args(np
, "clocks", "#clock-cells", index
,
4818 index
= clkspec
.args_count
? clkspec
.args
[0] : 0;
4821 /* if there is an indices property, use it to transfer the index
4822 * specified into an array offset for the clock-output-names property.
4824 of_property_for_each_u32(clkspec
.np
, "clock-indices", prop
, vp
, pv
) {
4831 /* We went off the end of 'clock-indices' without finding it */
4835 if (of_property_read_string_index(clkspec
.np
, "clock-output-names",
4839 * Best effort to get the name if the clock has been
4840 * registered with the framework. If the clock isn't
4841 * registered, we return the node name as the name of
4842 * the clock as long as #clock-cells = 0.
4844 clk
= of_clk_get_from_provider(&clkspec
);
4846 if (clkspec
.args_count
== 0)
4847 clk_name
= clkspec
.np
->name
;
4851 clk_name
= __clk_get_name(clk
);
4857 of_node_put(clkspec
.np
);
4860 EXPORT_SYMBOL_GPL(of_clk_get_parent_name
);
4863 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
4865 * @np: Device node pointer associated with clock provider
4866 * @parents: pointer to char array that hold the parents' names
4867 * @size: size of the @parents array
4869 * Return: number of parents for the clock node.
4871 int of_clk_parent_fill(struct device_node
*np
, const char **parents
,
4876 while (i
< size
&& (parents
[i
] = of_clk_get_parent_name(np
, i
)) != NULL
)
4881 EXPORT_SYMBOL_GPL(of_clk_parent_fill
);
4883 struct clock_provider
{
4884 void (*clk_init_cb
)(struct device_node
*);
4885 struct device_node
*np
;
4886 struct list_head node
;
4890 * This function looks for a parent clock. If there is one, then it
4891 * checks that the provider for this parent clock was initialized, in
4892 * this case the parent clock will be ready.
4894 static int parent_ready(struct device_node
*np
)
4899 struct clk
*clk
= of_clk_get(np
, i
);
4901 /* this parent is ready we can check the next one */
4908 /* at least one parent is not ready, we exit now */
4909 if (PTR_ERR(clk
) == -EPROBE_DEFER
)
4913 * Here we make assumption that the device tree is
4914 * written correctly. So an error means that there is
4915 * no more parent. As we didn't exit yet, then the
4916 * previous parent are ready. If there is no clock
4917 * parent, no need to wait for them, then we can
4918 * consider their absence as being ready
4925 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
4926 * @np: Device node pointer associated with clock provider
4927 * @index: clock index
4928 * @flags: pointer to top-level framework flags
4930 * Detects if the clock-critical property exists and, if so, sets the
4931 * corresponding CLK_IS_CRITICAL flag.
4933 * Do not use this function. It exists only for legacy Device Tree
4934 * bindings, such as the one-clock-per-node style that are outdated.
4935 * Those bindings typically put all clock data into .dts and the Linux
4936 * driver has no clock data, thus making it impossible to set this flag
4937 * correctly from the driver. Only those drivers may call
4938 * of_clk_detect_critical from their setup functions.
4940 * Return: error code or zero on success
4942 int of_clk_detect_critical(struct device_node
*np
, int index
,
4943 unsigned long *flags
)
4945 struct property
*prop
;
4952 of_property_for_each_u32(np
, "clock-critical", prop
, cur
, idx
)
4954 *flags
|= CLK_IS_CRITICAL
;
4960 * of_clk_init() - Scan and init clock providers from the DT
4961 * @matches: array of compatible values and init functions for providers.
4963 * This function scans the device tree for matching clock providers
4964 * and calls their initialization functions. It also does it by trying
4965 * to follow the dependencies.
4967 void __init
of_clk_init(const struct of_device_id
*matches
)
4969 const struct of_device_id
*match
;
4970 struct device_node
*np
;
4971 struct clock_provider
*clk_provider
, *next
;
4974 LIST_HEAD(clk_provider_list
);
4977 matches
= &__clk_of_table
;
4979 /* First prepare the list of the clocks providers */
4980 for_each_matching_node_and_match(np
, matches
, &match
) {
4981 struct clock_provider
*parent
;
4983 if (!of_device_is_available(np
))
4986 parent
= kzalloc(sizeof(*parent
), GFP_KERNEL
);
4988 list_for_each_entry_safe(clk_provider
, next
,
4989 &clk_provider_list
, node
) {
4990 list_del(&clk_provider
->node
);
4991 of_node_put(clk_provider
->np
);
4992 kfree(clk_provider
);
4998 parent
->clk_init_cb
= match
->data
;
4999 parent
->np
= of_node_get(np
);
5000 list_add_tail(&parent
->node
, &clk_provider_list
);
5003 while (!list_empty(&clk_provider_list
)) {
5004 is_init_done
= false;
5005 list_for_each_entry_safe(clk_provider
, next
,
5006 &clk_provider_list
, node
) {
5007 if (force
|| parent_ready(clk_provider
->np
)) {
5009 /* Don't populate platform devices */
5010 of_node_set_flag(clk_provider
->np
,
5013 clk_provider
->clk_init_cb(clk_provider
->np
);
5014 of_clk_set_defaults(clk_provider
->np
, true);
5016 list_del(&clk_provider
->node
);
5017 of_node_put(clk_provider
->np
);
5018 kfree(clk_provider
);
5019 is_init_done
= true;
5024 * We didn't manage to initialize any of the
5025 * remaining providers during the last loop, so now we
5026 * initialize all the remaining ones unconditionally
5027 * in case the clock parent was not mandatory