perf tools: Don't clone maps from parent when synthesizing forks
[linux/fpc-iii.git] / drivers / clk / clk.c
blobd31055ae6ec6f94c23409df9f47936f09b54c1bf
1 /*
2 * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
3 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * Standard functionality for the common clock API. See Documentation/driver-api/clk.rst
12 #include <linux/clk.h>
13 #include <linux/clk-provider.h>
14 #include <linux/clk/clk-conf.h>
15 #include <linux/module.h>
16 #include <linux/mutex.h>
17 #include <linux/spinlock.h>
18 #include <linux/err.h>
19 #include <linux/list.h>
20 #include <linux/slab.h>
21 #include <linux/of.h>
22 #include <linux/device.h>
23 #include <linux/init.h>
24 #include <linux/pm_runtime.h>
25 #include <linux/sched.h>
26 #include <linux/clkdev.h>
28 #include "clk.h"
30 static DEFINE_SPINLOCK(enable_lock);
31 static DEFINE_MUTEX(prepare_lock);
33 static struct task_struct *prepare_owner;
34 static struct task_struct *enable_owner;
36 static int prepare_refcnt;
37 static int enable_refcnt;
39 static HLIST_HEAD(clk_root_list);
40 static HLIST_HEAD(clk_orphan_list);
41 static LIST_HEAD(clk_notifier_list);
43 /*** private data structures ***/
45 struct clk_core {
46 const char *name;
47 const struct clk_ops *ops;
48 struct clk_hw *hw;
49 struct module *owner;
50 struct device *dev;
51 struct clk_core *parent;
52 const char **parent_names;
53 struct clk_core **parents;
54 u8 num_parents;
55 u8 new_parent_index;
56 unsigned long rate;
57 unsigned long req_rate;
58 unsigned long new_rate;
59 struct clk_core *new_parent;
60 struct clk_core *new_child;
61 unsigned long flags;
62 bool orphan;
63 unsigned int enable_count;
64 unsigned int prepare_count;
65 unsigned int protect_count;
66 unsigned long min_rate;
67 unsigned long max_rate;
68 unsigned long accuracy;
69 int phase;
70 struct clk_duty duty;
71 struct hlist_head children;
72 struct hlist_node child_node;
73 struct hlist_head clks;
74 unsigned int notifier_count;
75 #ifdef CONFIG_DEBUG_FS
76 struct dentry *dentry;
77 struct hlist_node debug_node;
78 #endif
79 struct kref ref;
82 #define CREATE_TRACE_POINTS
83 #include <trace/events/clk.h>
85 struct clk {
86 struct clk_core *core;
87 const char *dev_id;
88 const char *con_id;
89 unsigned long min_rate;
90 unsigned long max_rate;
91 unsigned int exclusive_count;
92 struct hlist_node clks_node;
95 /*** runtime pm ***/
96 static int clk_pm_runtime_get(struct clk_core *core)
98 int ret = 0;
100 if (!core->dev)
101 return 0;
103 ret = pm_runtime_get_sync(core->dev);
104 return ret < 0 ? ret : 0;
107 static void clk_pm_runtime_put(struct clk_core *core)
109 if (!core->dev)
110 return;
112 pm_runtime_put_sync(core->dev);
115 /*** locking ***/
116 static void clk_prepare_lock(void)
118 if (!mutex_trylock(&prepare_lock)) {
119 if (prepare_owner == current) {
120 prepare_refcnt++;
121 return;
123 mutex_lock(&prepare_lock);
125 WARN_ON_ONCE(prepare_owner != NULL);
126 WARN_ON_ONCE(prepare_refcnt != 0);
127 prepare_owner = current;
128 prepare_refcnt = 1;
131 static void clk_prepare_unlock(void)
133 WARN_ON_ONCE(prepare_owner != current);
134 WARN_ON_ONCE(prepare_refcnt == 0);
136 if (--prepare_refcnt)
137 return;
138 prepare_owner = NULL;
139 mutex_unlock(&prepare_lock);
142 static unsigned long clk_enable_lock(void)
143 __acquires(enable_lock)
145 unsigned long flags;
148 * On UP systems, spin_trylock_irqsave() always returns true, even if
149 * we already hold the lock. So, in that case, we rely only on
150 * reference counting.
152 if (!IS_ENABLED(CONFIG_SMP) ||
153 !spin_trylock_irqsave(&enable_lock, flags)) {
154 if (enable_owner == current) {
155 enable_refcnt++;
156 __acquire(enable_lock);
157 if (!IS_ENABLED(CONFIG_SMP))
158 local_save_flags(flags);
159 return flags;
161 spin_lock_irqsave(&enable_lock, flags);
163 WARN_ON_ONCE(enable_owner != NULL);
164 WARN_ON_ONCE(enable_refcnt != 0);
165 enable_owner = current;
166 enable_refcnt = 1;
167 return flags;
170 static void clk_enable_unlock(unsigned long flags)
171 __releases(enable_lock)
173 WARN_ON_ONCE(enable_owner != current);
174 WARN_ON_ONCE(enable_refcnt == 0);
176 if (--enable_refcnt) {
177 __release(enable_lock);
178 return;
180 enable_owner = NULL;
181 spin_unlock_irqrestore(&enable_lock, flags);
184 static bool clk_core_rate_is_protected(struct clk_core *core)
186 return core->protect_count;
189 static bool clk_core_is_prepared(struct clk_core *core)
191 bool ret = false;
194 * .is_prepared is optional for clocks that can prepare
195 * fall back to software usage counter if it is missing
197 if (!core->ops->is_prepared)
198 return core->prepare_count;
200 if (!clk_pm_runtime_get(core)) {
201 ret = core->ops->is_prepared(core->hw);
202 clk_pm_runtime_put(core);
205 return ret;
208 static bool clk_core_is_enabled(struct clk_core *core)
210 bool ret = false;
213 * .is_enabled is only mandatory for clocks that gate
214 * fall back to software usage counter if .is_enabled is missing
216 if (!core->ops->is_enabled)
217 return core->enable_count;
220 * Check if clock controller's device is runtime active before
221 * calling .is_enabled callback. If not, assume that clock is
222 * disabled, because we might be called from atomic context, from
223 * which pm_runtime_get() is not allowed.
224 * This function is called mainly from clk_disable_unused_subtree,
225 * which ensures proper runtime pm activation of controller before
226 * taking enable spinlock, but the below check is needed if one tries
227 * to call it from other places.
229 if (core->dev) {
230 pm_runtime_get_noresume(core->dev);
231 if (!pm_runtime_active(core->dev)) {
232 ret = false;
233 goto done;
237 ret = core->ops->is_enabled(core->hw);
238 done:
239 if (core->dev)
240 pm_runtime_put(core->dev);
242 return ret;
245 /*** helper functions ***/
247 const char *__clk_get_name(const struct clk *clk)
249 return !clk ? NULL : clk->core->name;
251 EXPORT_SYMBOL_GPL(__clk_get_name);
253 const char *clk_hw_get_name(const struct clk_hw *hw)
255 return hw->core->name;
257 EXPORT_SYMBOL_GPL(clk_hw_get_name);
259 struct clk_hw *__clk_get_hw(struct clk *clk)
261 return !clk ? NULL : clk->core->hw;
263 EXPORT_SYMBOL_GPL(__clk_get_hw);
265 unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
267 return hw->core->num_parents;
269 EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
271 struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
273 return hw->core->parent ? hw->core->parent->hw : NULL;
275 EXPORT_SYMBOL_GPL(clk_hw_get_parent);
277 static struct clk_core *__clk_lookup_subtree(const char *name,
278 struct clk_core *core)
280 struct clk_core *child;
281 struct clk_core *ret;
283 if (!strcmp(core->name, name))
284 return core;
286 hlist_for_each_entry(child, &core->children, child_node) {
287 ret = __clk_lookup_subtree(name, child);
288 if (ret)
289 return ret;
292 return NULL;
295 static struct clk_core *clk_core_lookup(const char *name)
297 struct clk_core *root_clk;
298 struct clk_core *ret;
300 if (!name)
301 return NULL;
303 /* search the 'proper' clk tree first */
304 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
305 ret = __clk_lookup_subtree(name, root_clk);
306 if (ret)
307 return ret;
310 /* if not found, then search the orphan tree */
311 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
312 ret = __clk_lookup_subtree(name, root_clk);
313 if (ret)
314 return ret;
317 return NULL;
320 static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
321 u8 index)
323 if (!core || index >= core->num_parents)
324 return NULL;
326 if (!core->parents[index])
327 core->parents[index] =
328 clk_core_lookup(core->parent_names[index]);
330 return core->parents[index];
333 struct clk_hw *
334 clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
336 struct clk_core *parent;
338 parent = clk_core_get_parent_by_index(hw->core, index);
340 return !parent ? NULL : parent->hw;
342 EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
344 unsigned int __clk_get_enable_count(struct clk *clk)
346 return !clk ? 0 : clk->core->enable_count;
349 static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
351 unsigned long ret;
353 if (!core) {
354 ret = 0;
355 goto out;
358 ret = core->rate;
360 if (!core->num_parents)
361 goto out;
363 if (!core->parent)
364 ret = 0;
366 out:
367 return ret;
370 unsigned long clk_hw_get_rate(const struct clk_hw *hw)
372 return clk_core_get_rate_nolock(hw->core);
374 EXPORT_SYMBOL_GPL(clk_hw_get_rate);
376 static unsigned long __clk_get_accuracy(struct clk_core *core)
378 if (!core)
379 return 0;
381 return core->accuracy;
384 unsigned long __clk_get_flags(struct clk *clk)
386 return !clk ? 0 : clk->core->flags;
388 EXPORT_SYMBOL_GPL(__clk_get_flags);
390 unsigned long clk_hw_get_flags(const struct clk_hw *hw)
392 return hw->core->flags;
394 EXPORT_SYMBOL_GPL(clk_hw_get_flags);
396 bool clk_hw_is_prepared(const struct clk_hw *hw)
398 return clk_core_is_prepared(hw->core);
401 bool clk_hw_rate_is_protected(const struct clk_hw *hw)
403 return clk_core_rate_is_protected(hw->core);
406 bool clk_hw_is_enabled(const struct clk_hw *hw)
408 return clk_core_is_enabled(hw->core);
411 bool __clk_is_enabled(struct clk *clk)
413 if (!clk)
414 return false;
416 return clk_core_is_enabled(clk->core);
418 EXPORT_SYMBOL_GPL(__clk_is_enabled);
420 static bool mux_is_better_rate(unsigned long rate, unsigned long now,
421 unsigned long best, unsigned long flags)
423 if (flags & CLK_MUX_ROUND_CLOSEST)
424 return abs(now - rate) < abs(best - rate);
426 return now <= rate && now > best;
429 int clk_mux_determine_rate_flags(struct clk_hw *hw,
430 struct clk_rate_request *req,
431 unsigned long flags)
433 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
434 int i, num_parents, ret;
435 unsigned long best = 0;
436 struct clk_rate_request parent_req = *req;
438 /* if NO_REPARENT flag set, pass through to current parent */
439 if (core->flags & CLK_SET_RATE_NO_REPARENT) {
440 parent = core->parent;
441 if (core->flags & CLK_SET_RATE_PARENT) {
442 ret = __clk_determine_rate(parent ? parent->hw : NULL,
443 &parent_req);
444 if (ret)
445 return ret;
447 best = parent_req.rate;
448 } else if (parent) {
449 best = clk_core_get_rate_nolock(parent);
450 } else {
451 best = clk_core_get_rate_nolock(core);
454 goto out;
457 /* find the parent that can provide the fastest rate <= rate */
458 num_parents = core->num_parents;
459 for (i = 0; i < num_parents; i++) {
460 parent = clk_core_get_parent_by_index(core, i);
461 if (!parent)
462 continue;
464 if (core->flags & CLK_SET_RATE_PARENT) {
465 parent_req = *req;
466 ret = __clk_determine_rate(parent->hw, &parent_req);
467 if (ret)
468 continue;
469 } else {
470 parent_req.rate = clk_core_get_rate_nolock(parent);
473 if (mux_is_better_rate(req->rate, parent_req.rate,
474 best, flags)) {
475 best_parent = parent;
476 best = parent_req.rate;
480 if (!best_parent)
481 return -EINVAL;
483 out:
484 if (best_parent)
485 req->best_parent_hw = best_parent->hw;
486 req->best_parent_rate = best;
487 req->rate = best;
489 return 0;
491 EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);
493 struct clk *__clk_lookup(const char *name)
495 struct clk_core *core = clk_core_lookup(name);
497 return !core ? NULL : core->hw->clk;
500 static void clk_core_get_boundaries(struct clk_core *core,
501 unsigned long *min_rate,
502 unsigned long *max_rate)
504 struct clk *clk_user;
506 *min_rate = core->min_rate;
507 *max_rate = core->max_rate;
509 hlist_for_each_entry(clk_user, &core->clks, clks_node)
510 *min_rate = max(*min_rate, clk_user->min_rate);
512 hlist_for_each_entry(clk_user, &core->clks, clks_node)
513 *max_rate = min(*max_rate, clk_user->max_rate);
516 void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
517 unsigned long max_rate)
519 hw->core->min_rate = min_rate;
520 hw->core->max_rate = max_rate;
522 EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
525 * Helper for finding best parent to provide a given frequency. This can be used
526 * directly as a determine_rate callback (e.g. for a mux), or from a more
527 * complex clock that may combine a mux with other operations.
529 int __clk_mux_determine_rate(struct clk_hw *hw,
530 struct clk_rate_request *req)
532 return clk_mux_determine_rate_flags(hw, req, 0);
534 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
536 int __clk_mux_determine_rate_closest(struct clk_hw *hw,
537 struct clk_rate_request *req)
539 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
541 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
543 /*** clk api ***/
545 static void clk_core_rate_unprotect(struct clk_core *core)
547 lockdep_assert_held(&prepare_lock);
549 if (!core)
550 return;
552 if (WARN(core->protect_count == 0,
553 "%s already unprotected\n", core->name))
554 return;
556 if (--core->protect_count > 0)
557 return;
559 clk_core_rate_unprotect(core->parent);
562 static int clk_core_rate_nuke_protect(struct clk_core *core)
564 int ret;
566 lockdep_assert_held(&prepare_lock);
568 if (!core)
569 return -EINVAL;
571 if (core->protect_count == 0)
572 return 0;
574 ret = core->protect_count;
575 core->protect_count = 1;
576 clk_core_rate_unprotect(core);
578 return ret;
582 * clk_rate_exclusive_put - release exclusivity over clock rate control
583 * @clk: the clk over which the exclusivity is released
585 * clk_rate_exclusive_put() completes a critical section during which a clock
586 * consumer cannot tolerate any other consumer making any operation on the
587 * clock which could result in a rate change or rate glitch. Exclusive clocks
588 * cannot have their rate changed, either directly or indirectly due to changes
589 * further up the parent chain of clocks. As a result, clocks up parent chain
590 * also get under exclusive control of the calling consumer.
592 * If exlusivity is claimed more than once on clock, even by the same consumer,
593 * the rate effectively gets locked as exclusivity can't be preempted.
595 * Calls to clk_rate_exclusive_put() must be balanced with calls to
596 * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
597 * error status.
599 void clk_rate_exclusive_put(struct clk *clk)
601 if (!clk)
602 return;
604 clk_prepare_lock();
607 * if there is something wrong with this consumer protect count, stop
608 * here before messing with the provider
610 if (WARN_ON(clk->exclusive_count <= 0))
611 goto out;
613 clk_core_rate_unprotect(clk->core);
614 clk->exclusive_count--;
615 out:
616 clk_prepare_unlock();
618 EXPORT_SYMBOL_GPL(clk_rate_exclusive_put);
620 static void clk_core_rate_protect(struct clk_core *core)
622 lockdep_assert_held(&prepare_lock);
624 if (!core)
625 return;
627 if (core->protect_count == 0)
628 clk_core_rate_protect(core->parent);
630 core->protect_count++;
633 static void clk_core_rate_restore_protect(struct clk_core *core, int count)
635 lockdep_assert_held(&prepare_lock);
637 if (!core)
638 return;
640 if (count == 0)
641 return;
643 clk_core_rate_protect(core);
644 core->protect_count = count;
648 * clk_rate_exclusive_get - get exclusivity over the clk rate control
649 * @clk: the clk over which the exclusity of rate control is requested
651 * clk_rate_exlusive_get() begins a critical section during which a clock
652 * consumer cannot tolerate any other consumer making any operation on the
653 * clock which could result in a rate change or rate glitch. Exclusive clocks
654 * cannot have their rate changed, either directly or indirectly due to changes
655 * further up the parent chain of clocks. As a result, clocks up parent chain
656 * also get under exclusive control of the calling consumer.
658 * If exlusivity is claimed more than once on clock, even by the same consumer,
659 * the rate effectively gets locked as exclusivity can't be preempted.
661 * Calls to clk_rate_exclusive_get() should be balanced with calls to
662 * clk_rate_exclusive_put(). Calls to this function may sleep.
663 * Returns 0 on success, -EERROR otherwise
665 int clk_rate_exclusive_get(struct clk *clk)
667 if (!clk)
668 return 0;
670 clk_prepare_lock();
671 clk_core_rate_protect(clk->core);
672 clk->exclusive_count++;
673 clk_prepare_unlock();
675 return 0;
677 EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
679 static void clk_core_unprepare(struct clk_core *core)
681 lockdep_assert_held(&prepare_lock);
683 if (!core)
684 return;
686 if (WARN(core->prepare_count == 0,
687 "%s already unprepared\n", core->name))
688 return;
690 if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL,
691 "Unpreparing critical %s\n", core->name))
692 return;
694 if (core->flags & CLK_SET_RATE_GATE)
695 clk_core_rate_unprotect(core);
697 if (--core->prepare_count > 0)
698 return;
700 WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);
702 trace_clk_unprepare(core);
704 if (core->ops->unprepare)
705 core->ops->unprepare(core->hw);
707 clk_pm_runtime_put(core);
709 trace_clk_unprepare_complete(core);
710 clk_core_unprepare(core->parent);
713 static void clk_core_unprepare_lock(struct clk_core *core)
715 clk_prepare_lock();
716 clk_core_unprepare(core);
717 clk_prepare_unlock();
721 * clk_unprepare - undo preparation of a clock source
722 * @clk: the clk being unprepared
724 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
725 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
726 * if the operation may sleep. One example is a clk which is accessed over
727 * I2c. In the complex case a clk gate operation may require a fast and a slow
728 * part. It is this reason that clk_unprepare and clk_disable are not mutually
729 * exclusive. In fact clk_disable must be called before clk_unprepare.
731 void clk_unprepare(struct clk *clk)
733 if (IS_ERR_OR_NULL(clk))
734 return;
736 clk_core_unprepare_lock(clk->core);
738 EXPORT_SYMBOL_GPL(clk_unprepare);
740 static int clk_core_prepare(struct clk_core *core)
742 int ret = 0;
744 lockdep_assert_held(&prepare_lock);
746 if (!core)
747 return 0;
749 if (core->prepare_count == 0) {
750 ret = clk_pm_runtime_get(core);
751 if (ret)
752 return ret;
754 ret = clk_core_prepare(core->parent);
755 if (ret)
756 goto runtime_put;
758 trace_clk_prepare(core);
760 if (core->ops->prepare)
761 ret = core->ops->prepare(core->hw);
763 trace_clk_prepare_complete(core);
765 if (ret)
766 goto unprepare;
769 core->prepare_count++;
772 * CLK_SET_RATE_GATE is a special case of clock protection
773 * Instead of a consumer claiming exclusive rate control, it is
774 * actually the provider which prevents any consumer from making any
775 * operation which could result in a rate change or rate glitch while
776 * the clock is prepared.
778 if (core->flags & CLK_SET_RATE_GATE)
779 clk_core_rate_protect(core);
781 return 0;
782 unprepare:
783 clk_core_unprepare(core->parent);
784 runtime_put:
785 clk_pm_runtime_put(core);
786 return ret;
789 static int clk_core_prepare_lock(struct clk_core *core)
791 int ret;
793 clk_prepare_lock();
794 ret = clk_core_prepare(core);
795 clk_prepare_unlock();
797 return ret;
801 * clk_prepare - prepare a clock source
802 * @clk: the clk being prepared
804 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
805 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
806 * operation may sleep. One example is a clk which is accessed over I2c. In
807 * the complex case a clk ungate operation may require a fast and a slow part.
808 * It is this reason that clk_prepare and clk_enable are not mutually
809 * exclusive. In fact clk_prepare must be called before clk_enable.
810 * Returns 0 on success, -EERROR otherwise.
812 int clk_prepare(struct clk *clk)
814 if (!clk)
815 return 0;
817 return clk_core_prepare_lock(clk->core);
819 EXPORT_SYMBOL_GPL(clk_prepare);
821 static void clk_core_disable(struct clk_core *core)
823 lockdep_assert_held(&enable_lock);
825 if (!core)
826 return;
828 if (WARN(core->enable_count == 0, "%s already disabled\n", core->name))
829 return;
831 if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL,
832 "Disabling critical %s\n", core->name))
833 return;
835 if (--core->enable_count > 0)
836 return;
838 trace_clk_disable_rcuidle(core);
840 if (core->ops->disable)
841 core->ops->disable(core->hw);
843 trace_clk_disable_complete_rcuidle(core);
845 clk_core_disable(core->parent);
848 static void clk_core_disable_lock(struct clk_core *core)
850 unsigned long flags;
852 flags = clk_enable_lock();
853 clk_core_disable(core);
854 clk_enable_unlock(flags);
858 * clk_disable - gate a clock
859 * @clk: the clk being gated
861 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
862 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
863 * clk if the operation is fast and will never sleep. One example is a
864 * SoC-internal clk which is controlled via simple register writes. In the
865 * complex case a clk gate operation may require a fast and a slow part. It is
866 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
867 * In fact clk_disable must be called before clk_unprepare.
869 void clk_disable(struct clk *clk)
871 if (IS_ERR_OR_NULL(clk))
872 return;
874 clk_core_disable_lock(clk->core);
876 EXPORT_SYMBOL_GPL(clk_disable);
878 static int clk_core_enable(struct clk_core *core)
880 int ret = 0;
882 lockdep_assert_held(&enable_lock);
884 if (!core)
885 return 0;
887 if (WARN(core->prepare_count == 0,
888 "Enabling unprepared %s\n", core->name))
889 return -ESHUTDOWN;
891 if (core->enable_count == 0) {
892 ret = clk_core_enable(core->parent);
894 if (ret)
895 return ret;
897 trace_clk_enable_rcuidle(core);
899 if (core->ops->enable)
900 ret = core->ops->enable(core->hw);
902 trace_clk_enable_complete_rcuidle(core);
904 if (ret) {
905 clk_core_disable(core->parent);
906 return ret;
910 core->enable_count++;
911 return 0;
914 static int clk_core_enable_lock(struct clk_core *core)
916 unsigned long flags;
917 int ret;
919 flags = clk_enable_lock();
920 ret = clk_core_enable(core);
921 clk_enable_unlock(flags);
923 return ret;
927 * clk_enable - ungate a clock
928 * @clk: the clk being ungated
930 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
931 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
932 * if the operation will never sleep. One example is a SoC-internal clk which
933 * is controlled via simple register writes. In the complex case a clk ungate
934 * operation may require a fast and a slow part. It is this reason that
935 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
936 * must be called before clk_enable. Returns 0 on success, -EERROR
937 * otherwise.
939 int clk_enable(struct clk *clk)
941 if (!clk)
942 return 0;
944 return clk_core_enable_lock(clk->core);
946 EXPORT_SYMBOL_GPL(clk_enable);
948 static int clk_core_prepare_enable(struct clk_core *core)
950 int ret;
952 ret = clk_core_prepare_lock(core);
953 if (ret)
954 return ret;
956 ret = clk_core_enable_lock(core);
957 if (ret)
958 clk_core_unprepare_lock(core);
960 return ret;
963 static void clk_core_disable_unprepare(struct clk_core *core)
965 clk_core_disable_lock(core);
966 clk_core_unprepare_lock(core);
969 static void clk_unprepare_unused_subtree(struct clk_core *core)
971 struct clk_core *child;
973 lockdep_assert_held(&prepare_lock);
975 hlist_for_each_entry(child, &core->children, child_node)
976 clk_unprepare_unused_subtree(child);
978 if (core->prepare_count)
979 return;
981 if (core->flags & CLK_IGNORE_UNUSED)
982 return;
984 if (clk_pm_runtime_get(core))
985 return;
987 if (clk_core_is_prepared(core)) {
988 trace_clk_unprepare(core);
989 if (core->ops->unprepare_unused)
990 core->ops->unprepare_unused(core->hw);
991 else if (core->ops->unprepare)
992 core->ops->unprepare(core->hw);
993 trace_clk_unprepare_complete(core);
996 clk_pm_runtime_put(core);
999 static void clk_disable_unused_subtree(struct clk_core *core)
1001 struct clk_core *child;
1002 unsigned long flags;
1004 lockdep_assert_held(&prepare_lock);
1006 hlist_for_each_entry(child, &core->children, child_node)
1007 clk_disable_unused_subtree(child);
1009 if (core->flags & CLK_OPS_PARENT_ENABLE)
1010 clk_core_prepare_enable(core->parent);
1012 if (clk_pm_runtime_get(core))
1013 goto unprepare_out;
1015 flags = clk_enable_lock();
1017 if (core->enable_count)
1018 goto unlock_out;
1020 if (core->flags & CLK_IGNORE_UNUSED)
1021 goto unlock_out;
1024 * some gate clocks have special needs during the disable-unused
1025 * sequence. call .disable_unused if available, otherwise fall
1026 * back to .disable
1028 if (clk_core_is_enabled(core)) {
1029 trace_clk_disable(core);
1030 if (core->ops->disable_unused)
1031 core->ops->disable_unused(core->hw);
1032 else if (core->ops->disable)
1033 core->ops->disable(core->hw);
1034 trace_clk_disable_complete(core);
1037 unlock_out:
1038 clk_enable_unlock(flags);
1039 clk_pm_runtime_put(core);
1040 unprepare_out:
1041 if (core->flags & CLK_OPS_PARENT_ENABLE)
1042 clk_core_disable_unprepare(core->parent);
1045 static bool clk_ignore_unused;
1046 static int __init clk_ignore_unused_setup(char *__unused)
1048 clk_ignore_unused = true;
1049 return 1;
1051 __setup("clk_ignore_unused", clk_ignore_unused_setup);
1053 static int clk_disable_unused(void)
1055 struct clk_core *core;
1057 if (clk_ignore_unused) {
1058 pr_warn("clk: Not disabling unused clocks\n");
1059 return 0;
1062 clk_prepare_lock();
1064 hlist_for_each_entry(core, &clk_root_list, child_node)
1065 clk_disable_unused_subtree(core);
1067 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1068 clk_disable_unused_subtree(core);
1070 hlist_for_each_entry(core, &clk_root_list, child_node)
1071 clk_unprepare_unused_subtree(core);
1073 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1074 clk_unprepare_unused_subtree(core);
1076 clk_prepare_unlock();
1078 return 0;
1080 late_initcall_sync(clk_disable_unused);
1082 static int clk_core_determine_round_nolock(struct clk_core *core,
1083 struct clk_rate_request *req)
1085 long rate;
1087 lockdep_assert_held(&prepare_lock);
1089 if (!core)
1090 return 0;
1093 * At this point, core protection will be disabled if
1094 * - if the provider is not protected at all
1095 * - if the calling consumer is the only one which has exclusivity
1096 * over the provider
1098 if (clk_core_rate_is_protected(core)) {
1099 req->rate = core->rate;
1100 } else if (core->ops->determine_rate) {
1101 return core->ops->determine_rate(core->hw, req);
1102 } else if (core->ops->round_rate) {
1103 rate = core->ops->round_rate(core->hw, req->rate,
1104 &req->best_parent_rate);
1105 if (rate < 0)
1106 return rate;
1108 req->rate = rate;
1109 } else {
1110 return -EINVAL;
1113 return 0;
1116 static void clk_core_init_rate_req(struct clk_core * const core,
1117 struct clk_rate_request *req)
1119 struct clk_core *parent;
1121 if (WARN_ON(!core || !req))
1122 return;
1124 parent = core->parent;
1125 if (parent) {
1126 req->best_parent_hw = parent->hw;
1127 req->best_parent_rate = parent->rate;
1128 } else {
1129 req->best_parent_hw = NULL;
1130 req->best_parent_rate = 0;
1134 static bool clk_core_can_round(struct clk_core * const core)
1136 if (core->ops->determine_rate || core->ops->round_rate)
1137 return true;
1139 return false;
1142 static int clk_core_round_rate_nolock(struct clk_core *core,
1143 struct clk_rate_request *req)
1145 lockdep_assert_held(&prepare_lock);
1147 if (!core) {
1148 req->rate = 0;
1149 return 0;
1152 clk_core_init_rate_req(core, req);
1154 if (clk_core_can_round(core))
1155 return clk_core_determine_round_nolock(core, req);
1156 else if (core->flags & CLK_SET_RATE_PARENT)
1157 return clk_core_round_rate_nolock(core->parent, req);
1159 req->rate = core->rate;
1160 return 0;
1164 * __clk_determine_rate - get the closest rate actually supported by a clock
1165 * @hw: determine the rate of this clock
1166 * @req: target rate request
1168 * Useful for clk_ops such as .set_rate and .determine_rate.
1170 int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
1172 if (!hw) {
1173 req->rate = 0;
1174 return 0;
1177 return clk_core_round_rate_nolock(hw->core, req);
1179 EXPORT_SYMBOL_GPL(__clk_determine_rate);
1181 unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
1183 int ret;
1184 struct clk_rate_request req;
1186 clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate);
1187 req.rate = rate;
1189 ret = clk_core_round_rate_nolock(hw->core, &req);
1190 if (ret)
1191 return 0;
1193 return req.rate;
1195 EXPORT_SYMBOL_GPL(clk_hw_round_rate);
1198 * clk_round_rate - round the given rate for a clk
1199 * @clk: the clk for which we are rounding a rate
1200 * @rate: the rate which is to be rounded
1202 * Takes in a rate as input and rounds it to a rate that the clk can actually
1203 * use which is then returned. If clk doesn't support round_rate operation
1204 * then the parent rate is returned.
1206 long clk_round_rate(struct clk *clk, unsigned long rate)
1208 struct clk_rate_request req;
1209 int ret;
1211 if (!clk)
1212 return 0;
1214 clk_prepare_lock();
1216 if (clk->exclusive_count)
1217 clk_core_rate_unprotect(clk->core);
1219 clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
1220 req.rate = rate;
1222 ret = clk_core_round_rate_nolock(clk->core, &req);
1224 if (clk->exclusive_count)
1225 clk_core_rate_protect(clk->core);
1227 clk_prepare_unlock();
1229 if (ret)
1230 return ret;
1232 return req.rate;
1234 EXPORT_SYMBOL_GPL(clk_round_rate);
1237 * __clk_notify - call clk notifier chain
1238 * @core: clk that is changing rate
1239 * @msg: clk notifier type (see include/linux/clk.h)
1240 * @old_rate: old clk rate
1241 * @new_rate: new clk rate
1243 * Triggers a notifier call chain on the clk rate-change notification
1244 * for 'clk'. Passes a pointer to the struct clk and the previous
1245 * and current rates to the notifier callback. Intended to be called by
1246 * internal clock code only. Returns NOTIFY_DONE from the last driver
1247 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1248 * a driver returns that.
1250 static int __clk_notify(struct clk_core *core, unsigned long msg,
1251 unsigned long old_rate, unsigned long new_rate)
1253 struct clk_notifier *cn;
1254 struct clk_notifier_data cnd;
1255 int ret = NOTIFY_DONE;
1257 cnd.old_rate = old_rate;
1258 cnd.new_rate = new_rate;
1260 list_for_each_entry(cn, &clk_notifier_list, node) {
1261 if (cn->clk->core == core) {
1262 cnd.clk = cn->clk;
1263 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
1264 &cnd);
1265 if (ret & NOTIFY_STOP_MASK)
1266 return ret;
1270 return ret;
1274 * __clk_recalc_accuracies
1275 * @core: first clk in the subtree
1277 * Walks the subtree of clks starting with clk and recalculates accuracies as
1278 * it goes. Note that if a clk does not implement the .recalc_accuracy
1279 * callback then it is assumed that the clock will take on the accuracy of its
1280 * parent.
1282 static void __clk_recalc_accuracies(struct clk_core *core)
1284 unsigned long parent_accuracy = 0;
1285 struct clk_core *child;
1287 lockdep_assert_held(&prepare_lock);
1289 if (core->parent)
1290 parent_accuracy = core->parent->accuracy;
1292 if (core->ops->recalc_accuracy)
1293 core->accuracy = core->ops->recalc_accuracy(core->hw,
1294 parent_accuracy);
1295 else
1296 core->accuracy = parent_accuracy;
1298 hlist_for_each_entry(child, &core->children, child_node)
1299 __clk_recalc_accuracies(child);
1302 static long clk_core_get_accuracy(struct clk_core *core)
1304 unsigned long accuracy;
1306 clk_prepare_lock();
1307 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
1308 __clk_recalc_accuracies(core);
1310 accuracy = __clk_get_accuracy(core);
1311 clk_prepare_unlock();
1313 return accuracy;
1317 * clk_get_accuracy - return the accuracy of clk
1318 * @clk: the clk whose accuracy is being returned
1320 * Simply returns the cached accuracy of the clk, unless
1321 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1322 * issued.
1323 * If clk is NULL then returns 0.
1325 long clk_get_accuracy(struct clk *clk)
1327 if (!clk)
1328 return 0;
1330 return clk_core_get_accuracy(clk->core);
1332 EXPORT_SYMBOL_GPL(clk_get_accuracy);
1334 static unsigned long clk_recalc(struct clk_core *core,
1335 unsigned long parent_rate)
1337 unsigned long rate = parent_rate;
1339 if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
1340 rate = core->ops->recalc_rate(core->hw, parent_rate);
1341 clk_pm_runtime_put(core);
1343 return rate;
1347 * __clk_recalc_rates
1348 * @core: first clk in the subtree
1349 * @msg: notification type (see include/linux/clk.h)
1351 * Walks the subtree of clks starting with clk and recalculates rates as it
1352 * goes. Note that if a clk does not implement the .recalc_rate callback then
1353 * it is assumed that the clock will take on the rate of its parent.
1355 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1356 * if necessary.
1358 static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
1360 unsigned long old_rate;
1361 unsigned long parent_rate = 0;
1362 struct clk_core *child;
1364 lockdep_assert_held(&prepare_lock);
1366 old_rate = core->rate;
1368 if (core->parent)
1369 parent_rate = core->parent->rate;
1371 core->rate = clk_recalc(core, parent_rate);
1374 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1375 * & ABORT_RATE_CHANGE notifiers
1377 if (core->notifier_count && msg)
1378 __clk_notify(core, msg, old_rate, core->rate);
1380 hlist_for_each_entry(child, &core->children, child_node)
1381 __clk_recalc_rates(child, msg);
1384 static unsigned long clk_core_get_rate(struct clk_core *core)
1386 unsigned long rate;
1388 clk_prepare_lock();
1390 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1391 __clk_recalc_rates(core, 0);
1393 rate = clk_core_get_rate_nolock(core);
1394 clk_prepare_unlock();
1396 return rate;
1400 * clk_get_rate - return the rate of clk
1401 * @clk: the clk whose rate is being returned
1403 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1404 * is set, which means a recalc_rate will be issued.
1405 * If clk is NULL then returns 0.
1407 unsigned long clk_get_rate(struct clk *clk)
1409 if (!clk)
1410 return 0;
1412 return clk_core_get_rate(clk->core);
1414 EXPORT_SYMBOL_GPL(clk_get_rate);
1416 static int clk_fetch_parent_index(struct clk_core *core,
1417 struct clk_core *parent)
1419 int i;
1421 if (!parent)
1422 return -EINVAL;
1424 for (i = 0; i < core->num_parents; i++)
1425 if (clk_core_get_parent_by_index(core, i) == parent)
1426 return i;
1428 return -EINVAL;
1432 * Update the orphan status of @core and all its children.
1434 static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
1436 struct clk_core *child;
1438 core->orphan = is_orphan;
1440 hlist_for_each_entry(child, &core->children, child_node)
1441 clk_core_update_orphan_status(child, is_orphan);
1444 static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1446 bool was_orphan = core->orphan;
1448 hlist_del(&core->child_node);
1450 if (new_parent) {
1451 bool becomes_orphan = new_parent->orphan;
1453 /* avoid duplicate POST_RATE_CHANGE notifications */
1454 if (new_parent->new_child == core)
1455 new_parent->new_child = NULL;
1457 hlist_add_head(&core->child_node, &new_parent->children);
1459 if (was_orphan != becomes_orphan)
1460 clk_core_update_orphan_status(core, becomes_orphan);
1461 } else {
1462 hlist_add_head(&core->child_node, &clk_orphan_list);
1463 if (!was_orphan)
1464 clk_core_update_orphan_status(core, true);
1467 core->parent = new_parent;
1470 static struct clk_core *__clk_set_parent_before(struct clk_core *core,
1471 struct clk_core *parent)
1473 unsigned long flags;
1474 struct clk_core *old_parent = core->parent;
1477 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
1479 * 2. Migrate prepare state between parents and prevent race with
1480 * clk_enable().
1482 * If the clock is not prepared, then a race with
1483 * clk_enable/disable() is impossible since we already have the
1484 * prepare lock (future calls to clk_enable() need to be preceded by
1485 * a clk_prepare()).
1487 * If the clock is prepared, migrate the prepared state to the new
1488 * parent and also protect against a race with clk_enable() by
1489 * forcing the clock and the new parent on. This ensures that all
1490 * future calls to clk_enable() are practically NOPs with respect to
1491 * hardware and software states.
1493 * See also: Comment for clk_set_parent() below.
1496 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
1497 if (core->flags & CLK_OPS_PARENT_ENABLE) {
1498 clk_core_prepare_enable(old_parent);
1499 clk_core_prepare_enable(parent);
1502 /* migrate prepare count if > 0 */
1503 if (core->prepare_count) {
1504 clk_core_prepare_enable(parent);
1505 clk_core_enable_lock(core);
1508 /* update the clk tree topology */
1509 flags = clk_enable_lock();
1510 clk_reparent(core, parent);
1511 clk_enable_unlock(flags);
1513 return old_parent;
1516 static void __clk_set_parent_after(struct clk_core *core,
1517 struct clk_core *parent,
1518 struct clk_core *old_parent)
1521 * Finish the migration of prepare state and undo the changes done
1522 * for preventing a race with clk_enable().
1524 if (core->prepare_count) {
1525 clk_core_disable_lock(core);
1526 clk_core_disable_unprepare(old_parent);
1529 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
1530 if (core->flags & CLK_OPS_PARENT_ENABLE) {
1531 clk_core_disable_unprepare(parent);
1532 clk_core_disable_unprepare(old_parent);
1536 static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
1537 u8 p_index)
1539 unsigned long flags;
1540 int ret = 0;
1541 struct clk_core *old_parent;
1543 old_parent = __clk_set_parent_before(core, parent);
1545 trace_clk_set_parent(core, parent);
1547 /* change clock input source */
1548 if (parent && core->ops->set_parent)
1549 ret = core->ops->set_parent(core->hw, p_index);
1551 trace_clk_set_parent_complete(core, parent);
1553 if (ret) {
1554 flags = clk_enable_lock();
1555 clk_reparent(core, old_parent);
1556 clk_enable_unlock(flags);
1557 __clk_set_parent_after(core, old_parent, parent);
1559 return ret;
1562 __clk_set_parent_after(core, parent, old_parent);
1564 return 0;
1568 * __clk_speculate_rates
1569 * @core: first clk in the subtree
1570 * @parent_rate: the "future" rate of clk's parent
1572 * Walks the subtree of clks starting with clk, speculating rates as it
1573 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1575 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1576 * pre-rate change notifications and returns early if no clks in the
1577 * subtree have subscribed to the notifications. Note that if a clk does not
1578 * implement the .recalc_rate callback then it is assumed that the clock will
1579 * take on the rate of its parent.
1581 static int __clk_speculate_rates(struct clk_core *core,
1582 unsigned long parent_rate)
1584 struct clk_core *child;
1585 unsigned long new_rate;
1586 int ret = NOTIFY_DONE;
1588 lockdep_assert_held(&prepare_lock);
1590 new_rate = clk_recalc(core, parent_rate);
1592 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1593 if (core->notifier_count)
1594 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
1596 if (ret & NOTIFY_STOP_MASK) {
1597 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1598 __func__, core->name, ret);
1599 goto out;
1602 hlist_for_each_entry(child, &core->children, child_node) {
1603 ret = __clk_speculate_rates(child, new_rate);
1604 if (ret & NOTIFY_STOP_MASK)
1605 break;
1608 out:
1609 return ret;
1612 static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
1613 struct clk_core *new_parent, u8 p_index)
1615 struct clk_core *child;
1617 core->new_rate = new_rate;
1618 core->new_parent = new_parent;
1619 core->new_parent_index = p_index;
1620 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1621 core->new_child = NULL;
1622 if (new_parent && new_parent != core->parent)
1623 new_parent->new_child = core;
1625 hlist_for_each_entry(child, &core->children, child_node) {
1626 child->new_rate = clk_recalc(child, new_rate);
1627 clk_calc_subtree(child, child->new_rate, NULL, 0);
1632 * calculate the new rates returning the topmost clock that has to be
1633 * changed.
1635 static struct clk_core *clk_calc_new_rates(struct clk_core *core,
1636 unsigned long rate)
1638 struct clk_core *top = core;
1639 struct clk_core *old_parent, *parent;
1640 unsigned long best_parent_rate = 0;
1641 unsigned long new_rate;
1642 unsigned long min_rate;
1643 unsigned long max_rate;
1644 int p_index = 0;
1645 long ret;
1647 /* sanity */
1648 if (IS_ERR_OR_NULL(core))
1649 return NULL;
1651 /* save parent rate, if it exists */
1652 parent = old_parent = core->parent;
1653 if (parent)
1654 best_parent_rate = parent->rate;
1656 clk_core_get_boundaries(core, &min_rate, &max_rate);
1658 /* find the closest rate and parent clk/rate */
1659 if (clk_core_can_round(core)) {
1660 struct clk_rate_request req;
1662 req.rate = rate;
1663 req.min_rate = min_rate;
1664 req.max_rate = max_rate;
1666 clk_core_init_rate_req(core, &req);
1668 ret = clk_core_determine_round_nolock(core, &req);
1669 if (ret < 0)
1670 return NULL;
1672 best_parent_rate = req.best_parent_rate;
1673 new_rate = req.rate;
1674 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
1676 if (new_rate < min_rate || new_rate > max_rate)
1677 return NULL;
1678 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
1679 /* pass-through clock without adjustable parent */
1680 core->new_rate = core->rate;
1681 return NULL;
1682 } else {
1683 /* pass-through clock with adjustable parent */
1684 top = clk_calc_new_rates(parent, rate);
1685 new_rate = parent->new_rate;
1686 goto out;
1689 /* some clocks must be gated to change parent */
1690 if (parent != old_parent &&
1691 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1692 pr_debug("%s: %s not gated but wants to reparent\n",
1693 __func__, core->name);
1694 return NULL;
1697 /* try finding the new parent index */
1698 if (parent && core->num_parents > 1) {
1699 p_index = clk_fetch_parent_index(core, parent);
1700 if (p_index < 0) {
1701 pr_debug("%s: clk %s can not be parent of clk %s\n",
1702 __func__, parent->name, core->name);
1703 return NULL;
1707 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
1708 best_parent_rate != parent->rate)
1709 top = clk_calc_new_rates(parent, best_parent_rate);
1711 out:
1712 clk_calc_subtree(core, new_rate, parent, p_index);
1714 return top;
1718 * Notify about rate changes in a subtree. Always walk down the whole tree
1719 * so that in case of an error we can walk down the whole tree again and
1720 * abort the change.
1722 static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
1723 unsigned long event)
1725 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
1726 int ret = NOTIFY_DONE;
1728 if (core->rate == core->new_rate)
1729 return NULL;
1731 if (core->notifier_count) {
1732 ret = __clk_notify(core, event, core->rate, core->new_rate);
1733 if (ret & NOTIFY_STOP_MASK)
1734 fail_clk = core;
1737 hlist_for_each_entry(child, &core->children, child_node) {
1738 /* Skip children who will be reparented to another clock */
1739 if (child->new_parent && child->new_parent != core)
1740 continue;
1741 tmp_clk = clk_propagate_rate_change(child, event);
1742 if (tmp_clk)
1743 fail_clk = tmp_clk;
1746 /* handle the new child who might not be in core->children yet */
1747 if (core->new_child) {
1748 tmp_clk = clk_propagate_rate_change(core->new_child, event);
1749 if (tmp_clk)
1750 fail_clk = tmp_clk;
1753 return fail_clk;
1757 * walk down a subtree and set the new rates notifying the rate
1758 * change on the way
1760 static void clk_change_rate(struct clk_core *core)
1762 struct clk_core *child;
1763 struct hlist_node *tmp;
1764 unsigned long old_rate;
1765 unsigned long best_parent_rate = 0;
1766 bool skip_set_rate = false;
1767 struct clk_core *old_parent;
1768 struct clk_core *parent = NULL;
1770 old_rate = core->rate;
1772 if (core->new_parent) {
1773 parent = core->new_parent;
1774 best_parent_rate = core->new_parent->rate;
1775 } else if (core->parent) {
1776 parent = core->parent;
1777 best_parent_rate = core->parent->rate;
1780 if (clk_pm_runtime_get(core))
1781 return;
1783 if (core->flags & CLK_SET_RATE_UNGATE) {
1784 unsigned long flags;
1786 clk_core_prepare(core);
1787 flags = clk_enable_lock();
1788 clk_core_enable(core);
1789 clk_enable_unlock(flags);
1792 if (core->new_parent && core->new_parent != core->parent) {
1793 old_parent = __clk_set_parent_before(core, core->new_parent);
1794 trace_clk_set_parent(core, core->new_parent);
1796 if (core->ops->set_rate_and_parent) {
1797 skip_set_rate = true;
1798 core->ops->set_rate_and_parent(core->hw, core->new_rate,
1799 best_parent_rate,
1800 core->new_parent_index);
1801 } else if (core->ops->set_parent) {
1802 core->ops->set_parent(core->hw, core->new_parent_index);
1805 trace_clk_set_parent_complete(core, core->new_parent);
1806 __clk_set_parent_after(core, core->new_parent, old_parent);
1809 if (core->flags & CLK_OPS_PARENT_ENABLE)
1810 clk_core_prepare_enable(parent);
1812 trace_clk_set_rate(core, core->new_rate);
1814 if (!skip_set_rate && core->ops->set_rate)
1815 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
1817 trace_clk_set_rate_complete(core, core->new_rate);
1819 core->rate = clk_recalc(core, best_parent_rate);
1821 if (core->flags & CLK_SET_RATE_UNGATE) {
1822 unsigned long flags;
1824 flags = clk_enable_lock();
1825 clk_core_disable(core);
1826 clk_enable_unlock(flags);
1827 clk_core_unprepare(core);
1830 if (core->flags & CLK_OPS_PARENT_ENABLE)
1831 clk_core_disable_unprepare(parent);
1833 if (core->notifier_count && old_rate != core->rate)
1834 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
1836 if (core->flags & CLK_RECALC_NEW_RATES)
1837 (void)clk_calc_new_rates(core, core->new_rate);
1840 * Use safe iteration, as change_rate can actually swap parents
1841 * for certain clock types.
1843 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
1844 /* Skip children who will be reparented to another clock */
1845 if (child->new_parent && child->new_parent != core)
1846 continue;
1847 clk_change_rate(child);
1850 /* handle the new child who might not be in core->children yet */
1851 if (core->new_child)
1852 clk_change_rate(core->new_child);
1854 clk_pm_runtime_put(core);
1857 static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
1858 unsigned long req_rate)
1860 int ret, cnt;
1861 struct clk_rate_request req;
1863 lockdep_assert_held(&prepare_lock);
1865 if (!core)
1866 return 0;
1868 /* simulate what the rate would be if it could be freely set */
1869 cnt = clk_core_rate_nuke_protect(core);
1870 if (cnt < 0)
1871 return cnt;
1873 clk_core_get_boundaries(core, &req.min_rate, &req.max_rate);
1874 req.rate = req_rate;
1876 ret = clk_core_round_rate_nolock(core, &req);
1878 /* restore the protection */
1879 clk_core_rate_restore_protect(core, cnt);
1881 return ret ? 0 : req.rate;
1884 static int clk_core_set_rate_nolock(struct clk_core *core,
1885 unsigned long req_rate)
1887 struct clk_core *top, *fail_clk;
1888 unsigned long rate;
1889 int ret = 0;
1891 if (!core)
1892 return 0;
1894 rate = clk_core_req_round_rate_nolock(core, req_rate);
1896 /* bail early if nothing to do */
1897 if (rate == clk_core_get_rate_nolock(core))
1898 return 0;
1900 /* fail on a direct rate set of a protected provider */
1901 if (clk_core_rate_is_protected(core))
1902 return -EBUSY;
1904 /* calculate new rates and get the topmost changed clock */
1905 top = clk_calc_new_rates(core, req_rate);
1906 if (!top)
1907 return -EINVAL;
1909 ret = clk_pm_runtime_get(core);
1910 if (ret)
1911 return ret;
1913 /* notify that we are about to change rates */
1914 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
1915 if (fail_clk) {
1916 pr_debug("%s: failed to set %s rate\n", __func__,
1917 fail_clk->name);
1918 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
1919 ret = -EBUSY;
1920 goto err;
1923 /* change the rates */
1924 clk_change_rate(top);
1926 core->req_rate = req_rate;
1927 err:
1928 clk_pm_runtime_put(core);
1930 return ret;
1934 * clk_set_rate - specify a new rate for clk
1935 * @clk: the clk whose rate is being changed
1936 * @rate: the new rate for clk
1938 * In the simplest case clk_set_rate will only adjust the rate of clk.
1940 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1941 * propagate up to clk's parent; whether or not this happens depends on the
1942 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1943 * after calling .round_rate then upstream parent propagation is ignored. If
1944 * *parent_rate comes back with a new rate for clk's parent then we propagate
1945 * up to clk's parent and set its rate. Upward propagation will continue
1946 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1947 * .round_rate stops requesting changes to clk's parent_rate.
1949 * Rate changes are accomplished via tree traversal that also recalculates the
1950 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
1952 * Returns 0 on success, -EERROR otherwise.
1954 int clk_set_rate(struct clk *clk, unsigned long rate)
1956 int ret;
1958 if (!clk)
1959 return 0;
1961 /* prevent racing with updates to the clock topology */
1962 clk_prepare_lock();
1964 if (clk->exclusive_count)
1965 clk_core_rate_unprotect(clk->core);
1967 ret = clk_core_set_rate_nolock(clk->core, rate);
1969 if (clk->exclusive_count)
1970 clk_core_rate_protect(clk->core);
1972 clk_prepare_unlock();
1974 return ret;
1976 EXPORT_SYMBOL_GPL(clk_set_rate);
1979 * clk_set_rate_exclusive - specify a new rate get exclusive control
1980 * @clk: the clk whose rate is being changed
1981 * @rate: the new rate for clk
1983 * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
1984 * within a critical section
1986 * This can be used initially to ensure that at least 1 consumer is
1987 * statisfied when several consumers are competing for exclusivity over the
1988 * same clock provider.
1990 * The exclusivity is not applied if setting the rate failed.
1992 * Calls to clk_rate_exclusive_get() should be balanced with calls to
1993 * clk_rate_exclusive_put().
1995 * Returns 0 on success, -EERROR otherwise.
1997 int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
1999 int ret;
2001 if (!clk)
2002 return 0;
2004 /* prevent racing with updates to the clock topology */
2005 clk_prepare_lock();
2008 * The temporary protection removal is not here, on purpose
2009 * This function is meant to be used instead of clk_rate_protect,
2010 * so before the consumer code path protect the clock provider
2013 ret = clk_core_set_rate_nolock(clk->core, rate);
2014 if (!ret) {
2015 clk_core_rate_protect(clk->core);
2016 clk->exclusive_count++;
2019 clk_prepare_unlock();
2021 return ret;
2023 EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
2026 * clk_set_rate_range - set a rate range for a clock source
2027 * @clk: clock source
2028 * @min: desired minimum clock rate in Hz, inclusive
2029 * @max: desired maximum clock rate in Hz, inclusive
2031 * Returns success (0) or negative errno.
2033 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
2035 int ret = 0;
2036 unsigned long old_min, old_max, rate;
2038 if (!clk)
2039 return 0;
2041 if (min > max) {
2042 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
2043 __func__, clk->core->name, clk->dev_id, clk->con_id,
2044 min, max);
2045 return -EINVAL;
2048 clk_prepare_lock();
2050 if (clk->exclusive_count)
2051 clk_core_rate_unprotect(clk->core);
2053 /* Save the current values in case we need to rollback the change */
2054 old_min = clk->min_rate;
2055 old_max = clk->max_rate;
2056 clk->min_rate = min;
2057 clk->max_rate = max;
2059 rate = clk_core_get_rate_nolock(clk->core);
2060 if (rate < min || rate > max) {
2062 * FIXME:
2063 * We are in bit of trouble here, current rate is outside the
2064 * the requested range. We are going try to request appropriate
2065 * range boundary but there is a catch. It may fail for the
2066 * usual reason (clock broken, clock protected, etc) but also
2067 * because:
2068 * - round_rate() was not favorable and fell on the wrong
2069 * side of the boundary
2070 * - the determine_rate() callback does not really check for
2071 * this corner case when determining the rate
2074 if (rate < min)
2075 rate = min;
2076 else
2077 rate = max;
2079 ret = clk_core_set_rate_nolock(clk->core, rate);
2080 if (ret) {
2081 /* rollback the changes */
2082 clk->min_rate = old_min;
2083 clk->max_rate = old_max;
2087 if (clk->exclusive_count)
2088 clk_core_rate_protect(clk->core);
2090 clk_prepare_unlock();
2092 return ret;
2094 EXPORT_SYMBOL_GPL(clk_set_rate_range);
2097 * clk_set_min_rate - set a minimum clock rate for a clock source
2098 * @clk: clock source
2099 * @rate: desired minimum clock rate in Hz, inclusive
2101 * Returns success (0) or negative errno.
2103 int clk_set_min_rate(struct clk *clk, unsigned long rate)
2105 if (!clk)
2106 return 0;
2108 return clk_set_rate_range(clk, rate, clk->max_rate);
2110 EXPORT_SYMBOL_GPL(clk_set_min_rate);
2113 * clk_set_max_rate - set a maximum clock rate for a clock source
2114 * @clk: clock source
2115 * @rate: desired maximum clock rate in Hz, inclusive
2117 * Returns success (0) or negative errno.
2119 int clk_set_max_rate(struct clk *clk, unsigned long rate)
2121 if (!clk)
2122 return 0;
2124 return clk_set_rate_range(clk, clk->min_rate, rate);
2126 EXPORT_SYMBOL_GPL(clk_set_max_rate);
2129 * clk_get_parent - return the parent of a clk
2130 * @clk: the clk whose parent gets returned
2132 * Simply returns clk->parent. Returns NULL if clk is NULL.
2134 struct clk *clk_get_parent(struct clk *clk)
2136 struct clk *parent;
2138 if (!clk)
2139 return NULL;
2141 clk_prepare_lock();
2142 /* TODO: Create a per-user clk and change callers to call clk_put */
2143 parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
2144 clk_prepare_unlock();
2146 return parent;
2148 EXPORT_SYMBOL_GPL(clk_get_parent);
2150 static struct clk_core *__clk_init_parent(struct clk_core *core)
2152 u8 index = 0;
2154 if (core->num_parents > 1 && core->ops->get_parent)
2155 index = core->ops->get_parent(core->hw);
2157 return clk_core_get_parent_by_index(core, index);
2160 static void clk_core_reparent(struct clk_core *core,
2161 struct clk_core *new_parent)
2163 clk_reparent(core, new_parent);
2164 __clk_recalc_accuracies(core);
2165 __clk_recalc_rates(core, POST_RATE_CHANGE);
2168 void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
2170 if (!hw)
2171 return;
2173 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
2177 * clk_has_parent - check if a clock is a possible parent for another
2178 * @clk: clock source
2179 * @parent: parent clock source
2181 * This function can be used in drivers that need to check that a clock can be
2182 * the parent of another without actually changing the parent.
2184 * Returns true if @parent is a possible parent for @clk, false otherwise.
2186 bool clk_has_parent(struct clk *clk, struct clk *parent)
2188 struct clk_core *core, *parent_core;
2190 /* NULL clocks should be nops, so return success if either is NULL. */
2191 if (!clk || !parent)
2192 return true;
2194 core = clk->core;
2195 parent_core = parent->core;
2197 /* Optimize for the case where the parent is already the parent. */
2198 if (core->parent == parent_core)
2199 return true;
2201 return match_string(core->parent_names, core->num_parents,
2202 parent_core->name) >= 0;
2204 EXPORT_SYMBOL_GPL(clk_has_parent);
2206 static int clk_core_set_parent_nolock(struct clk_core *core,
2207 struct clk_core *parent)
2209 int ret = 0;
2210 int p_index = 0;
2211 unsigned long p_rate = 0;
2213 lockdep_assert_held(&prepare_lock);
2215 if (!core)
2216 return 0;
2218 if (core->parent == parent)
2219 return 0;
2221 /* verify ops for for multi-parent clks */
2222 if (core->num_parents > 1 && !core->ops->set_parent)
2223 return -EPERM;
2225 /* check that we are allowed to re-parent if the clock is in use */
2226 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
2227 return -EBUSY;
2229 if (clk_core_rate_is_protected(core))
2230 return -EBUSY;
2232 /* try finding the new parent index */
2233 if (parent) {
2234 p_index = clk_fetch_parent_index(core, parent);
2235 if (p_index < 0) {
2236 pr_debug("%s: clk %s can not be parent of clk %s\n",
2237 __func__, parent->name, core->name);
2238 return p_index;
2240 p_rate = parent->rate;
2243 ret = clk_pm_runtime_get(core);
2244 if (ret)
2245 return ret;
2247 /* propagate PRE_RATE_CHANGE notifications */
2248 ret = __clk_speculate_rates(core, p_rate);
2250 /* abort if a driver objects */
2251 if (ret & NOTIFY_STOP_MASK)
2252 goto runtime_put;
2254 /* do the re-parent */
2255 ret = __clk_set_parent(core, parent, p_index);
2257 /* propagate rate an accuracy recalculation accordingly */
2258 if (ret) {
2259 __clk_recalc_rates(core, ABORT_RATE_CHANGE);
2260 } else {
2261 __clk_recalc_rates(core, POST_RATE_CHANGE);
2262 __clk_recalc_accuracies(core);
2265 runtime_put:
2266 clk_pm_runtime_put(core);
2268 return ret;
2272 * clk_set_parent - switch the parent of a mux clk
2273 * @clk: the mux clk whose input we are switching
2274 * @parent: the new input to clk
2276 * Re-parent clk to use parent as its new input source. If clk is in
2277 * prepared state, the clk will get enabled for the duration of this call. If
2278 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2279 * that, the reparenting is glitchy in hardware, etc), use the
2280 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2282 * After successfully changing clk's parent clk_set_parent will update the
2283 * clk topology, sysfs topology and propagate rate recalculation via
2284 * __clk_recalc_rates.
2286 * Returns 0 on success, -EERROR otherwise.
2288 int clk_set_parent(struct clk *clk, struct clk *parent)
2290 int ret;
2292 if (!clk)
2293 return 0;
2295 clk_prepare_lock();
2297 if (clk->exclusive_count)
2298 clk_core_rate_unprotect(clk->core);
2300 ret = clk_core_set_parent_nolock(clk->core,
2301 parent ? parent->core : NULL);
2303 if (clk->exclusive_count)
2304 clk_core_rate_protect(clk->core);
2306 clk_prepare_unlock();
2308 return ret;
2310 EXPORT_SYMBOL_GPL(clk_set_parent);
2312 static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
2314 int ret = -EINVAL;
2316 lockdep_assert_held(&prepare_lock);
2318 if (!core)
2319 return 0;
2321 if (clk_core_rate_is_protected(core))
2322 return -EBUSY;
2324 trace_clk_set_phase(core, degrees);
2326 if (core->ops->set_phase) {
2327 ret = core->ops->set_phase(core->hw, degrees);
2328 if (!ret)
2329 core->phase = degrees;
2332 trace_clk_set_phase_complete(core, degrees);
2334 return ret;
2338 * clk_set_phase - adjust the phase shift of a clock signal
2339 * @clk: clock signal source
2340 * @degrees: number of degrees the signal is shifted
2342 * Shifts the phase of a clock signal by the specified
2343 * degrees. Returns 0 on success, -EERROR otherwise.
2345 * This function makes no distinction about the input or reference
2346 * signal that we adjust the clock signal phase against. For example
2347 * phase locked-loop clock signal generators we may shift phase with
2348 * respect to feedback clock signal input, but for other cases the
2349 * clock phase may be shifted with respect to some other, unspecified
2350 * signal.
2352 * Additionally the concept of phase shift does not propagate through
2353 * the clock tree hierarchy, which sets it apart from clock rates and
2354 * clock accuracy. A parent clock phase attribute does not have an
2355 * impact on the phase attribute of a child clock.
2357 int clk_set_phase(struct clk *clk, int degrees)
2359 int ret;
2361 if (!clk)
2362 return 0;
2364 /* sanity check degrees */
2365 degrees %= 360;
2366 if (degrees < 0)
2367 degrees += 360;
2369 clk_prepare_lock();
2371 if (clk->exclusive_count)
2372 clk_core_rate_unprotect(clk->core);
2374 ret = clk_core_set_phase_nolock(clk->core, degrees);
2376 if (clk->exclusive_count)
2377 clk_core_rate_protect(clk->core);
2379 clk_prepare_unlock();
2381 return ret;
2383 EXPORT_SYMBOL_GPL(clk_set_phase);
2385 static int clk_core_get_phase(struct clk_core *core)
2387 int ret;
2389 clk_prepare_lock();
2390 /* Always try to update cached phase if possible */
2391 if (core->ops->get_phase)
2392 core->phase = core->ops->get_phase(core->hw);
2393 ret = core->phase;
2394 clk_prepare_unlock();
2396 return ret;
2400 * clk_get_phase - return the phase shift of a clock signal
2401 * @clk: clock signal source
2403 * Returns the phase shift of a clock node in degrees, otherwise returns
2404 * -EERROR.
2406 int clk_get_phase(struct clk *clk)
2408 if (!clk)
2409 return 0;
2411 return clk_core_get_phase(clk->core);
2413 EXPORT_SYMBOL_GPL(clk_get_phase);
2415 static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
2417 /* Assume a default value of 50% */
2418 core->duty.num = 1;
2419 core->duty.den = 2;
2422 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);
2424 static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
2426 struct clk_duty *duty = &core->duty;
2427 int ret = 0;
2429 if (!core->ops->get_duty_cycle)
2430 return clk_core_update_duty_cycle_parent_nolock(core);
2432 ret = core->ops->get_duty_cycle(core->hw, duty);
2433 if (ret)
2434 goto reset;
2436 /* Don't trust the clock provider too much */
2437 if (duty->den == 0 || duty->num > duty->den) {
2438 ret = -EINVAL;
2439 goto reset;
2442 return 0;
2444 reset:
2445 clk_core_reset_duty_cycle_nolock(core);
2446 return ret;
2449 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
2451 int ret = 0;
2453 if (core->parent &&
2454 core->flags & CLK_DUTY_CYCLE_PARENT) {
2455 ret = clk_core_update_duty_cycle_nolock(core->parent);
2456 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
2457 } else {
2458 clk_core_reset_duty_cycle_nolock(core);
2461 return ret;
2464 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
2465 struct clk_duty *duty);
2467 static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
2468 struct clk_duty *duty)
2470 int ret;
2472 lockdep_assert_held(&prepare_lock);
2474 if (clk_core_rate_is_protected(core))
2475 return -EBUSY;
2477 trace_clk_set_duty_cycle(core, duty);
2479 if (!core->ops->set_duty_cycle)
2480 return clk_core_set_duty_cycle_parent_nolock(core, duty);
2482 ret = core->ops->set_duty_cycle(core->hw, duty);
2483 if (!ret)
2484 memcpy(&core->duty, duty, sizeof(*duty));
2486 trace_clk_set_duty_cycle_complete(core, duty);
2488 return ret;
2491 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
2492 struct clk_duty *duty)
2494 int ret = 0;
2496 if (core->parent &&
2497 core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
2498 ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
2499 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
2502 return ret;
2506 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
2507 * @clk: clock signal source
2508 * @num: numerator of the duty cycle ratio to be applied
2509 * @den: denominator of the duty cycle ratio to be applied
2511 * Apply the duty cycle ratio if the ratio is valid and the clock can
2512 * perform this operation
2514 * Returns (0) on success, a negative errno otherwise.
2516 int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
2518 int ret;
2519 struct clk_duty duty;
2521 if (!clk)
2522 return 0;
2524 /* sanity check the ratio */
2525 if (den == 0 || num > den)
2526 return -EINVAL;
2528 duty.num = num;
2529 duty.den = den;
2531 clk_prepare_lock();
2533 if (clk->exclusive_count)
2534 clk_core_rate_unprotect(clk->core);
2536 ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
2538 if (clk->exclusive_count)
2539 clk_core_rate_protect(clk->core);
2541 clk_prepare_unlock();
2543 return ret;
2545 EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
2547 static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
2548 unsigned int scale)
2550 struct clk_duty *duty = &core->duty;
2551 int ret;
2553 clk_prepare_lock();
2555 ret = clk_core_update_duty_cycle_nolock(core);
2556 if (!ret)
2557 ret = mult_frac(scale, duty->num, duty->den);
2559 clk_prepare_unlock();
2561 return ret;
2565 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
2566 * @clk: clock signal source
2567 * @scale: scaling factor to be applied to represent the ratio as an integer
2569 * Returns the duty cycle ratio of a clock node multiplied by the provided
2570 * scaling factor, or negative errno on error.
2572 int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
2574 if (!clk)
2575 return 0;
2577 return clk_core_get_scaled_duty_cycle(clk->core, scale);
2579 EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
2582 * clk_is_match - check if two clk's point to the same hardware clock
2583 * @p: clk compared against q
2584 * @q: clk compared against p
2586 * Returns true if the two struct clk pointers both point to the same hardware
2587 * clock node. Put differently, returns true if struct clk *p and struct clk *q
2588 * share the same struct clk_core object.
2590 * Returns false otherwise. Note that two NULL clks are treated as matching.
2592 bool clk_is_match(const struct clk *p, const struct clk *q)
2594 /* trivial case: identical struct clk's or both NULL */
2595 if (p == q)
2596 return true;
2598 /* true if clk->core pointers match. Avoid dereferencing garbage */
2599 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
2600 if (p->core == q->core)
2601 return true;
2603 return false;
2605 EXPORT_SYMBOL_GPL(clk_is_match);
2607 /*** debugfs support ***/
2609 #ifdef CONFIG_DEBUG_FS
2610 #include <linux/debugfs.h>
2612 static struct dentry *rootdir;
2613 static int inited = 0;
2614 static DEFINE_MUTEX(clk_debug_lock);
2615 static HLIST_HEAD(clk_debug_list);
2617 static struct hlist_head *all_lists[] = {
2618 &clk_root_list,
2619 &clk_orphan_list,
2620 NULL,
2623 static struct hlist_head *orphan_list[] = {
2624 &clk_orphan_list,
2625 NULL,
2628 static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
2629 int level)
2631 if (!c)
2632 return;
2634 seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu %5d %6d\n",
2635 level * 3 + 1, "",
2636 30 - level * 3, c->name,
2637 c->enable_count, c->prepare_count, c->protect_count,
2638 clk_core_get_rate(c), clk_core_get_accuracy(c),
2639 clk_core_get_phase(c),
2640 clk_core_get_scaled_duty_cycle(c, 100000));
2643 static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
2644 int level)
2646 struct clk_core *child;
2648 if (!c)
2649 return;
2651 clk_summary_show_one(s, c, level);
2653 hlist_for_each_entry(child, &c->children, child_node)
2654 clk_summary_show_subtree(s, child, level + 1);
2657 static int clk_summary_show(struct seq_file *s, void *data)
2659 struct clk_core *c;
2660 struct hlist_head **lists = (struct hlist_head **)s->private;
2662 seq_puts(s, " enable prepare protect duty\n");
2663 seq_puts(s, " clock count count count rate accuracy phase cycle\n");
2664 seq_puts(s, "---------------------------------------------------------------------------------------------\n");
2666 clk_prepare_lock();
2668 for (; *lists; lists++)
2669 hlist_for_each_entry(c, *lists, child_node)
2670 clk_summary_show_subtree(s, c, 0);
2672 clk_prepare_unlock();
2674 return 0;
2676 DEFINE_SHOW_ATTRIBUTE(clk_summary);
2678 static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
2680 if (!c)
2681 return;
2683 /* This should be JSON format, i.e. elements separated with a comma */
2684 seq_printf(s, "\"%s\": { ", c->name);
2685 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
2686 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
2687 seq_printf(s, "\"protect_count\": %d,", c->protect_count);
2688 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate(c));
2689 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c));
2690 seq_printf(s, "\"phase\": %d", clk_core_get_phase(c));
2691 seq_printf(s, "\"duty_cycle\": %u",
2692 clk_core_get_scaled_duty_cycle(c, 100000));
2695 static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
2697 struct clk_core *child;
2699 if (!c)
2700 return;
2702 clk_dump_one(s, c, level);
2704 hlist_for_each_entry(child, &c->children, child_node) {
2705 seq_putc(s, ',');
2706 clk_dump_subtree(s, child, level + 1);
2709 seq_putc(s, '}');
2712 static int clk_dump_show(struct seq_file *s, void *data)
2714 struct clk_core *c;
2715 bool first_node = true;
2716 struct hlist_head **lists = (struct hlist_head **)s->private;
2718 seq_putc(s, '{');
2719 clk_prepare_lock();
2721 for (; *lists; lists++) {
2722 hlist_for_each_entry(c, *lists, child_node) {
2723 if (!first_node)
2724 seq_putc(s, ',');
2725 first_node = false;
2726 clk_dump_subtree(s, c, 0);
2730 clk_prepare_unlock();
2732 seq_puts(s, "}\n");
2733 return 0;
2735 DEFINE_SHOW_ATTRIBUTE(clk_dump);
2737 static const struct {
2738 unsigned long flag;
2739 const char *name;
2740 } clk_flags[] = {
2741 #define ENTRY(f) { f, #f }
2742 ENTRY(CLK_SET_RATE_GATE),
2743 ENTRY(CLK_SET_PARENT_GATE),
2744 ENTRY(CLK_SET_RATE_PARENT),
2745 ENTRY(CLK_IGNORE_UNUSED),
2746 ENTRY(CLK_IS_BASIC),
2747 ENTRY(CLK_GET_RATE_NOCACHE),
2748 ENTRY(CLK_SET_RATE_NO_REPARENT),
2749 ENTRY(CLK_GET_ACCURACY_NOCACHE),
2750 ENTRY(CLK_RECALC_NEW_RATES),
2751 ENTRY(CLK_SET_RATE_UNGATE),
2752 ENTRY(CLK_IS_CRITICAL),
2753 ENTRY(CLK_OPS_PARENT_ENABLE),
2754 ENTRY(CLK_DUTY_CYCLE_PARENT),
2755 #undef ENTRY
2758 static int clk_flags_show(struct seq_file *s, void *data)
2760 struct clk_core *core = s->private;
2761 unsigned long flags = core->flags;
2762 unsigned int i;
2764 for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
2765 if (flags & clk_flags[i].flag) {
2766 seq_printf(s, "%s\n", clk_flags[i].name);
2767 flags &= ~clk_flags[i].flag;
2770 if (flags) {
2771 /* Unknown flags */
2772 seq_printf(s, "0x%lx\n", flags);
2775 return 0;
2777 DEFINE_SHOW_ATTRIBUTE(clk_flags);
2779 static int possible_parents_show(struct seq_file *s, void *data)
2781 struct clk_core *core = s->private;
2782 int i;
2784 for (i = 0; i < core->num_parents - 1; i++)
2785 seq_printf(s, "%s ", core->parent_names[i]);
2787 seq_printf(s, "%s\n", core->parent_names[i]);
2789 return 0;
2791 DEFINE_SHOW_ATTRIBUTE(possible_parents);
2793 static int clk_duty_cycle_show(struct seq_file *s, void *data)
2795 struct clk_core *core = s->private;
2796 struct clk_duty *duty = &core->duty;
2798 seq_printf(s, "%u/%u\n", duty->num, duty->den);
2800 return 0;
2802 DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
2804 static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
2806 struct dentry *root;
2808 if (!core || !pdentry)
2809 return;
2811 root = debugfs_create_dir(core->name, pdentry);
2812 core->dentry = root;
2814 debugfs_create_ulong("clk_rate", 0444, root, &core->rate);
2815 debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
2816 debugfs_create_u32("clk_phase", 0444, root, &core->phase);
2817 debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
2818 debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
2819 debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
2820 debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
2821 debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
2822 debugfs_create_file("clk_duty_cycle", 0444, root, core,
2823 &clk_duty_cycle_fops);
2825 if (core->num_parents > 1)
2826 debugfs_create_file("clk_possible_parents", 0444, root, core,
2827 &possible_parents_fops);
2829 if (core->ops->debug_init)
2830 core->ops->debug_init(core->hw, core->dentry);
2834 * clk_debug_register - add a clk node to the debugfs clk directory
2835 * @core: the clk being added to the debugfs clk directory
2837 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
2838 * initialized. Otherwise it bails out early since the debugfs clk directory
2839 * will be created lazily by clk_debug_init as part of a late_initcall.
2841 static void clk_debug_register(struct clk_core *core)
2843 mutex_lock(&clk_debug_lock);
2844 hlist_add_head(&core->debug_node, &clk_debug_list);
2845 if (inited)
2846 clk_debug_create_one(core, rootdir);
2847 mutex_unlock(&clk_debug_lock);
2851 * clk_debug_unregister - remove a clk node from the debugfs clk directory
2852 * @core: the clk being removed from the debugfs clk directory
2854 * Dynamically removes a clk and all its child nodes from the
2855 * debugfs clk directory if clk->dentry points to debugfs created by
2856 * clk_debug_register in __clk_core_init.
2858 static void clk_debug_unregister(struct clk_core *core)
2860 mutex_lock(&clk_debug_lock);
2861 hlist_del_init(&core->debug_node);
2862 debugfs_remove_recursive(core->dentry);
2863 core->dentry = NULL;
2864 mutex_unlock(&clk_debug_lock);
2868 * clk_debug_init - lazily populate the debugfs clk directory
2870 * clks are often initialized very early during boot before memory can be
2871 * dynamically allocated and well before debugfs is setup. This function
2872 * populates the debugfs clk directory once at boot-time when we know that
2873 * debugfs is setup. It should only be called once at boot-time, all other clks
2874 * added dynamically will be done so with clk_debug_register.
2876 static int __init clk_debug_init(void)
2878 struct clk_core *core;
2880 rootdir = debugfs_create_dir("clk", NULL);
2882 debugfs_create_file("clk_summary", 0444, rootdir, &all_lists,
2883 &clk_summary_fops);
2884 debugfs_create_file("clk_dump", 0444, rootdir, &all_lists,
2885 &clk_dump_fops);
2886 debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list,
2887 &clk_summary_fops);
2888 debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list,
2889 &clk_dump_fops);
2891 mutex_lock(&clk_debug_lock);
2892 hlist_for_each_entry(core, &clk_debug_list, debug_node)
2893 clk_debug_create_one(core, rootdir);
2895 inited = 1;
2896 mutex_unlock(&clk_debug_lock);
2898 return 0;
2900 late_initcall(clk_debug_init);
2901 #else
2902 static inline void clk_debug_register(struct clk_core *core) { }
2903 static inline void clk_debug_reparent(struct clk_core *core,
2904 struct clk_core *new_parent)
2907 static inline void clk_debug_unregister(struct clk_core *core)
2910 #endif
2913 * __clk_core_init - initialize the data structures in a struct clk_core
2914 * @core: clk_core being initialized
2916 * Initializes the lists in struct clk_core, queries the hardware for the
2917 * parent and rate and sets them both.
2919 static int __clk_core_init(struct clk_core *core)
2921 int i, ret;
2922 struct clk_core *orphan;
2923 struct hlist_node *tmp2;
2924 unsigned long rate;
2926 if (!core)
2927 return -EINVAL;
2929 clk_prepare_lock();
2931 ret = clk_pm_runtime_get(core);
2932 if (ret)
2933 goto unlock;
2935 /* check to see if a clock with this name is already registered */
2936 if (clk_core_lookup(core->name)) {
2937 pr_debug("%s: clk %s already initialized\n",
2938 __func__, core->name);
2939 ret = -EEXIST;
2940 goto out;
2943 /* check that clk_ops are sane. See Documentation/driver-api/clk.rst */
2944 if (core->ops->set_rate &&
2945 !((core->ops->round_rate || core->ops->determine_rate) &&
2946 core->ops->recalc_rate)) {
2947 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
2948 __func__, core->name);
2949 ret = -EINVAL;
2950 goto out;
2953 if (core->ops->set_parent && !core->ops->get_parent) {
2954 pr_err("%s: %s must implement .get_parent & .set_parent\n",
2955 __func__, core->name);
2956 ret = -EINVAL;
2957 goto out;
2960 if (core->num_parents > 1 && !core->ops->get_parent) {
2961 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
2962 __func__, core->name);
2963 ret = -EINVAL;
2964 goto out;
2967 if (core->ops->set_rate_and_parent &&
2968 !(core->ops->set_parent && core->ops->set_rate)) {
2969 pr_err("%s: %s must implement .set_parent & .set_rate\n",
2970 __func__, core->name);
2971 ret = -EINVAL;
2972 goto out;
2975 /* throw a WARN if any entries in parent_names are NULL */
2976 for (i = 0; i < core->num_parents; i++)
2977 WARN(!core->parent_names[i],
2978 "%s: invalid NULL in %s's .parent_names\n",
2979 __func__, core->name);
2981 core->parent = __clk_init_parent(core);
2984 * Populate core->parent if parent has already been clk_core_init'd. If
2985 * parent has not yet been clk_core_init'd then place clk in the orphan
2986 * list. If clk doesn't have any parents then place it in the root
2987 * clk list.
2989 * Every time a new clk is clk_init'd then we walk the list of orphan
2990 * clocks and re-parent any that are children of the clock currently
2991 * being clk_init'd.
2993 if (core->parent) {
2994 hlist_add_head(&core->child_node,
2995 &core->parent->children);
2996 core->orphan = core->parent->orphan;
2997 } else if (!core->num_parents) {
2998 hlist_add_head(&core->child_node, &clk_root_list);
2999 core->orphan = false;
3000 } else {
3001 hlist_add_head(&core->child_node, &clk_orphan_list);
3002 core->orphan = true;
3006 * optional platform-specific magic
3008 * The .init callback is not used by any of the basic clock types, but
3009 * exists for weird hardware that must perform initialization magic.
3010 * Please consider other ways of solving initialization problems before
3011 * using this callback, as its use is discouraged.
3013 if (core->ops->init)
3014 core->ops->init(core->hw);
3017 * Set clk's accuracy. The preferred method is to use
3018 * .recalc_accuracy. For simple clocks and lazy developers the default
3019 * fallback is to use the parent's accuracy. If a clock doesn't have a
3020 * parent (or is orphaned) then accuracy is set to zero (perfect
3021 * clock).
3023 if (core->ops->recalc_accuracy)
3024 core->accuracy = core->ops->recalc_accuracy(core->hw,
3025 __clk_get_accuracy(core->parent));
3026 else if (core->parent)
3027 core->accuracy = core->parent->accuracy;
3028 else
3029 core->accuracy = 0;
3032 * Set clk's phase.
3033 * Since a phase is by definition relative to its parent, just
3034 * query the current clock phase, or just assume it's in phase.
3036 if (core->ops->get_phase)
3037 core->phase = core->ops->get_phase(core->hw);
3038 else
3039 core->phase = 0;
3042 * Set clk's duty cycle.
3044 clk_core_update_duty_cycle_nolock(core);
3047 * Set clk's rate. The preferred method is to use .recalc_rate. For
3048 * simple clocks and lazy developers the default fallback is to use the
3049 * parent's rate. If a clock doesn't have a parent (or is orphaned)
3050 * then rate is set to zero.
3052 if (core->ops->recalc_rate)
3053 rate = core->ops->recalc_rate(core->hw,
3054 clk_core_get_rate_nolock(core->parent));
3055 else if (core->parent)
3056 rate = core->parent->rate;
3057 else
3058 rate = 0;
3059 core->rate = core->req_rate = rate;
3062 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
3063 * don't get accidentally disabled when walking the orphan tree and
3064 * reparenting clocks
3066 if (core->flags & CLK_IS_CRITICAL) {
3067 unsigned long flags;
3069 clk_core_prepare(core);
3071 flags = clk_enable_lock();
3072 clk_core_enable(core);
3073 clk_enable_unlock(flags);
3077 * walk the list of orphan clocks and reparent any that newly finds a
3078 * parent.
3080 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
3081 struct clk_core *parent = __clk_init_parent(orphan);
3084 * We need to use __clk_set_parent_before() and _after() to
3085 * to properly migrate any prepare/enable count of the orphan
3086 * clock. This is important for CLK_IS_CRITICAL clocks, which
3087 * are enabled during init but might not have a parent yet.
3089 if (parent) {
3090 /* update the clk tree topology */
3091 __clk_set_parent_before(orphan, parent);
3092 __clk_set_parent_after(orphan, parent, NULL);
3093 __clk_recalc_accuracies(orphan);
3094 __clk_recalc_rates(orphan, 0);
3098 kref_init(&core->ref);
3099 out:
3100 clk_pm_runtime_put(core);
3101 unlock:
3102 clk_prepare_unlock();
3104 if (!ret)
3105 clk_debug_register(core);
3107 return ret;
3110 struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,
3111 const char *con_id)
3113 struct clk *clk;
3115 /* This is to allow this function to be chained to others */
3116 if (IS_ERR_OR_NULL(hw))
3117 return ERR_CAST(hw);
3119 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
3120 if (!clk)
3121 return ERR_PTR(-ENOMEM);
3123 clk->core = hw->core;
3124 clk->dev_id = dev_id;
3125 clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
3126 clk->max_rate = ULONG_MAX;
3128 clk_prepare_lock();
3129 hlist_add_head(&clk->clks_node, &hw->core->clks);
3130 clk_prepare_unlock();
3132 return clk;
3135 /* keep in sync with __clk_put */
3136 void __clk_free_clk(struct clk *clk)
3138 clk_prepare_lock();
3139 hlist_del(&clk->clks_node);
3140 clk_prepare_unlock();
3142 kfree_const(clk->con_id);
3143 kfree(clk);
3147 * clk_register - allocate a new clock, register it and return an opaque cookie
3148 * @dev: device that is registering this clock
3149 * @hw: link to hardware-specific clock data
3151 * clk_register is the primary interface for populating the clock tree with new
3152 * clock nodes. It returns a pointer to the newly allocated struct clk which
3153 * cannot be dereferenced by driver code but may be used in conjunction with the
3154 * rest of the clock API. In the event of an error clk_register will return an
3155 * error code; drivers must test for an error code after calling clk_register.
3157 struct clk *clk_register(struct device *dev, struct clk_hw *hw)
3159 int i, ret;
3160 struct clk_core *core;
3162 core = kzalloc(sizeof(*core), GFP_KERNEL);
3163 if (!core) {
3164 ret = -ENOMEM;
3165 goto fail_out;
3168 core->name = kstrdup_const(hw->init->name, GFP_KERNEL);
3169 if (!core->name) {
3170 ret = -ENOMEM;
3171 goto fail_name;
3174 if (WARN_ON(!hw->init->ops)) {
3175 ret = -EINVAL;
3176 goto fail_ops;
3178 core->ops = hw->init->ops;
3180 if (dev && pm_runtime_enabled(dev))
3181 core->dev = dev;
3182 if (dev && dev->driver)
3183 core->owner = dev->driver->owner;
3184 core->hw = hw;
3185 core->flags = hw->init->flags;
3186 core->num_parents = hw->init->num_parents;
3187 core->min_rate = 0;
3188 core->max_rate = ULONG_MAX;
3189 hw->core = core;
3191 /* allocate local copy in case parent_names is __initdata */
3192 core->parent_names = kcalloc(core->num_parents, sizeof(char *),
3193 GFP_KERNEL);
3195 if (!core->parent_names) {
3196 ret = -ENOMEM;
3197 goto fail_parent_names;
3201 /* copy each string name in case parent_names is __initdata */
3202 for (i = 0; i < core->num_parents; i++) {
3203 core->parent_names[i] = kstrdup_const(hw->init->parent_names[i],
3204 GFP_KERNEL);
3205 if (!core->parent_names[i]) {
3206 ret = -ENOMEM;
3207 goto fail_parent_names_copy;
3211 /* avoid unnecessary string look-ups of clk_core's possible parents. */
3212 core->parents = kcalloc(core->num_parents, sizeof(*core->parents),
3213 GFP_KERNEL);
3214 if (!core->parents) {
3215 ret = -ENOMEM;
3216 goto fail_parents;
3219 INIT_HLIST_HEAD(&core->clks);
3221 hw->clk = __clk_create_clk(hw, NULL, NULL);
3222 if (IS_ERR(hw->clk)) {
3223 ret = PTR_ERR(hw->clk);
3224 goto fail_parents;
3227 ret = __clk_core_init(core);
3228 if (!ret)
3229 return hw->clk;
3231 __clk_free_clk(hw->clk);
3232 hw->clk = NULL;
3234 fail_parents:
3235 kfree(core->parents);
3236 fail_parent_names_copy:
3237 while (--i >= 0)
3238 kfree_const(core->parent_names[i]);
3239 kfree(core->parent_names);
3240 fail_parent_names:
3241 fail_ops:
3242 kfree_const(core->name);
3243 fail_name:
3244 kfree(core);
3245 fail_out:
3246 return ERR_PTR(ret);
3248 EXPORT_SYMBOL_GPL(clk_register);
3251 * clk_hw_register - register a clk_hw and return an error code
3252 * @dev: device that is registering this clock
3253 * @hw: link to hardware-specific clock data
3255 * clk_hw_register is the primary interface for populating the clock tree with
3256 * new clock nodes. It returns an integer equal to zero indicating success or
3257 * less than zero indicating failure. Drivers must test for an error code after
3258 * calling clk_hw_register().
3260 int clk_hw_register(struct device *dev, struct clk_hw *hw)
3262 return PTR_ERR_OR_ZERO(clk_register(dev, hw));
3264 EXPORT_SYMBOL_GPL(clk_hw_register);
3266 /* Free memory allocated for a clock. */
3267 static void __clk_release(struct kref *ref)
3269 struct clk_core *core = container_of(ref, struct clk_core, ref);
3270 int i = core->num_parents;
3272 lockdep_assert_held(&prepare_lock);
3274 kfree(core->parents);
3275 while (--i >= 0)
3276 kfree_const(core->parent_names[i]);
3278 kfree(core->parent_names);
3279 kfree_const(core->name);
3280 kfree(core);
3284 * Empty clk_ops for unregistered clocks. These are used temporarily
3285 * after clk_unregister() was called on a clock and until last clock
3286 * consumer calls clk_put() and the struct clk object is freed.
3288 static int clk_nodrv_prepare_enable(struct clk_hw *hw)
3290 return -ENXIO;
3293 static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
3295 WARN_ON_ONCE(1);
3298 static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
3299 unsigned long parent_rate)
3301 return -ENXIO;
3304 static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
3306 return -ENXIO;
3309 static const struct clk_ops clk_nodrv_ops = {
3310 .enable = clk_nodrv_prepare_enable,
3311 .disable = clk_nodrv_disable_unprepare,
3312 .prepare = clk_nodrv_prepare_enable,
3313 .unprepare = clk_nodrv_disable_unprepare,
3314 .set_rate = clk_nodrv_set_rate,
3315 .set_parent = clk_nodrv_set_parent,
3319 * clk_unregister - unregister a currently registered clock
3320 * @clk: clock to unregister
3322 void clk_unregister(struct clk *clk)
3324 unsigned long flags;
3326 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
3327 return;
3329 clk_debug_unregister(clk->core);
3331 clk_prepare_lock();
3333 if (clk->core->ops == &clk_nodrv_ops) {
3334 pr_err("%s: unregistered clock: %s\n", __func__,
3335 clk->core->name);
3336 goto unlock;
3339 * Assign empty clock ops for consumers that might still hold
3340 * a reference to this clock.
3342 flags = clk_enable_lock();
3343 clk->core->ops = &clk_nodrv_ops;
3344 clk_enable_unlock(flags);
3346 if (!hlist_empty(&clk->core->children)) {
3347 struct clk_core *child;
3348 struct hlist_node *t;
3350 /* Reparent all children to the orphan list. */
3351 hlist_for_each_entry_safe(child, t, &clk->core->children,
3352 child_node)
3353 clk_core_set_parent_nolock(child, NULL);
3356 hlist_del_init(&clk->core->child_node);
3358 if (clk->core->prepare_count)
3359 pr_warn("%s: unregistering prepared clock: %s\n",
3360 __func__, clk->core->name);
3362 if (clk->core->protect_count)
3363 pr_warn("%s: unregistering protected clock: %s\n",
3364 __func__, clk->core->name);
3366 kref_put(&clk->core->ref, __clk_release);
3367 unlock:
3368 clk_prepare_unlock();
3370 EXPORT_SYMBOL_GPL(clk_unregister);
3373 * clk_hw_unregister - unregister a currently registered clk_hw
3374 * @hw: hardware-specific clock data to unregister
3376 void clk_hw_unregister(struct clk_hw *hw)
3378 clk_unregister(hw->clk);
3380 EXPORT_SYMBOL_GPL(clk_hw_unregister);
3382 static void devm_clk_release(struct device *dev, void *res)
3384 clk_unregister(*(struct clk **)res);
3387 static void devm_clk_hw_release(struct device *dev, void *res)
3389 clk_hw_unregister(*(struct clk_hw **)res);
3393 * devm_clk_register - resource managed clk_register()
3394 * @dev: device that is registering this clock
3395 * @hw: link to hardware-specific clock data
3397 * Managed clk_register(). Clocks returned from this function are
3398 * automatically clk_unregister()ed on driver detach. See clk_register() for
3399 * more information.
3401 struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
3403 struct clk *clk;
3404 struct clk **clkp;
3406 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
3407 if (!clkp)
3408 return ERR_PTR(-ENOMEM);
3410 clk = clk_register(dev, hw);
3411 if (!IS_ERR(clk)) {
3412 *clkp = clk;
3413 devres_add(dev, clkp);
3414 } else {
3415 devres_free(clkp);
3418 return clk;
3420 EXPORT_SYMBOL_GPL(devm_clk_register);
3423 * devm_clk_hw_register - resource managed clk_hw_register()
3424 * @dev: device that is registering this clock
3425 * @hw: link to hardware-specific clock data
3427 * Managed clk_hw_register(). Clocks registered by this function are
3428 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
3429 * for more information.
3431 int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
3433 struct clk_hw **hwp;
3434 int ret;
3436 hwp = devres_alloc(devm_clk_hw_release, sizeof(*hwp), GFP_KERNEL);
3437 if (!hwp)
3438 return -ENOMEM;
3440 ret = clk_hw_register(dev, hw);
3441 if (!ret) {
3442 *hwp = hw;
3443 devres_add(dev, hwp);
3444 } else {
3445 devres_free(hwp);
3448 return ret;
3450 EXPORT_SYMBOL_GPL(devm_clk_hw_register);
3452 static int devm_clk_match(struct device *dev, void *res, void *data)
3454 struct clk *c = res;
3455 if (WARN_ON(!c))
3456 return 0;
3457 return c == data;
3460 static int devm_clk_hw_match(struct device *dev, void *res, void *data)
3462 struct clk_hw *hw = res;
3464 if (WARN_ON(!hw))
3465 return 0;
3466 return hw == data;
3470 * devm_clk_unregister - resource managed clk_unregister()
3471 * @clk: clock to unregister
3473 * Deallocate a clock allocated with devm_clk_register(). Normally
3474 * this function will not need to be called and the resource management
3475 * code will ensure that the resource is freed.
3477 void devm_clk_unregister(struct device *dev, struct clk *clk)
3479 WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
3481 EXPORT_SYMBOL_GPL(devm_clk_unregister);
3484 * devm_clk_hw_unregister - resource managed clk_hw_unregister()
3485 * @dev: device that is unregistering the hardware-specific clock data
3486 * @hw: link to hardware-specific clock data
3488 * Unregister a clk_hw registered with devm_clk_hw_register(). Normally
3489 * this function will not need to be called and the resource management
3490 * code will ensure that the resource is freed.
3492 void devm_clk_hw_unregister(struct device *dev, struct clk_hw *hw)
3494 WARN_ON(devres_release(dev, devm_clk_hw_release, devm_clk_hw_match,
3495 hw));
3497 EXPORT_SYMBOL_GPL(devm_clk_hw_unregister);
3500 * clkdev helpers
3502 int __clk_get(struct clk *clk)
3504 struct clk_core *core = !clk ? NULL : clk->core;
3506 if (core) {
3507 if (!try_module_get(core->owner))
3508 return 0;
3510 kref_get(&core->ref);
3512 return 1;
3515 /* keep in sync with __clk_free_clk */
3516 void __clk_put(struct clk *clk)
3518 struct module *owner;
3520 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
3521 return;
3523 clk_prepare_lock();
3526 * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
3527 * given user should be balanced with calls to clk_rate_exclusive_put()
3528 * and by that same consumer
3530 if (WARN_ON(clk->exclusive_count)) {
3531 /* We voiced our concern, let's sanitize the situation */
3532 clk->core->protect_count -= (clk->exclusive_count - 1);
3533 clk_core_rate_unprotect(clk->core);
3534 clk->exclusive_count = 0;
3537 hlist_del(&clk->clks_node);
3538 if (clk->min_rate > clk->core->req_rate ||
3539 clk->max_rate < clk->core->req_rate)
3540 clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
3542 owner = clk->core->owner;
3543 kref_put(&clk->core->ref, __clk_release);
3545 clk_prepare_unlock();
3547 module_put(owner);
3549 kfree_const(clk->con_id);
3550 kfree(clk);
3553 /*** clk rate change notifiers ***/
3556 * clk_notifier_register - add a clk rate change notifier
3557 * @clk: struct clk * to watch
3558 * @nb: struct notifier_block * with callback info
3560 * Request notification when clk's rate changes. This uses an SRCU
3561 * notifier because we want it to block and notifier unregistrations are
3562 * uncommon. The callbacks associated with the notifier must not
3563 * re-enter into the clk framework by calling any top-level clk APIs;
3564 * this will cause a nested prepare_lock mutex.
3566 * In all notification cases (pre, post and abort rate change) the original
3567 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
3568 * and the new frequency is passed via struct clk_notifier_data.new_rate.
3570 * clk_notifier_register() must be called from non-atomic context.
3571 * Returns -EINVAL if called with null arguments, -ENOMEM upon
3572 * allocation failure; otherwise, passes along the return value of
3573 * srcu_notifier_chain_register().
3575 int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
3577 struct clk_notifier *cn;
3578 int ret = -ENOMEM;
3580 if (!clk || !nb)
3581 return -EINVAL;
3583 clk_prepare_lock();
3585 /* search the list of notifiers for this clk */
3586 list_for_each_entry(cn, &clk_notifier_list, node)
3587 if (cn->clk == clk)
3588 break;
3590 /* if clk wasn't in the notifier list, allocate new clk_notifier */
3591 if (cn->clk != clk) {
3592 cn = kzalloc(sizeof(*cn), GFP_KERNEL);
3593 if (!cn)
3594 goto out;
3596 cn->clk = clk;
3597 srcu_init_notifier_head(&cn->notifier_head);
3599 list_add(&cn->node, &clk_notifier_list);
3602 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
3604 clk->core->notifier_count++;
3606 out:
3607 clk_prepare_unlock();
3609 return ret;
3611 EXPORT_SYMBOL_GPL(clk_notifier_register);
3614 * clk_notifier_unregister - remove a clk rate change notifier
3615 * @clk: struct clk *
3616 * @nb: struct notifier_block * with callback info
3618 * Request no further notification for changes to 'clk' and frees memory
3619 * allocated in clk_notifier_register.
3621 * Returns -EINVAL if called with null arguments; otherwise, passes
3622 * along the return value of srcu_notifier_chain_unregister().
3624 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
3626 struct clk_notifier *cn = NULL;
3627 int ret = -EINVAL;
3629 if (!clk || !nb)
3630 return -EINVAL;
3632 clk_prepare_lock();
3634 list_for_each_entry(cn, &clk_notifier_list, node)
3635 if (cn->clk == clk)
3636 break;
3638 if (cn->clk == clk) {
3639 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
3641 clk->core->notifier_count--;
3643 /* XXX the notifier code should handle this better */
3644 if (!cn->notifier_head.head) {
3645 srcu_cleanup_notifier_head(&cn->notifier_head);
3646 list_del(&cn->node);
3647 kfree(cn);
3650 } else {
3651 ret = -ENOENT;
3654 clk_prepare_unlock();
3656 return ret;
3658 EXPORT_SYMBOL_GPL(clk_notifier_unregister);
3660 #ifdef CONFIG_OF
3662 * struct of_clk_provider - Clock provider registration structure
3663 * @link: Entry in global list of clock providers
3664 * @node: Pointer to device tree node of clock provider
3665 * @get: Get clock callback. Returns NULL or a struct clk for the
3666 * given clock specifier
3667 * @data: context pointer to be passed into @get callback
3669 struct of_clk_provider {
3670 struct list_head link;
3672 struct device_node *node;
3673 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
3674 struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
3675 void *data;
3678 static const struct of_device_id __clk_of_table_sentinel
3679 __used __section(__clk_of_table_end);
3681 static LIST_HEAD(of_clk_providers);
3682 static DEFINE_MUTEX(of_clk_mutex);
3684 struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
3685 void *data)
3687 return data;
3689 EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
3691 struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
3693 return data;
3695 EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
3697 struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
3699 struct clk_onecell_data *clk_data = data;
3700 unsigned int idx = clkspec->args[0];
3702 if (idx >= clk_data->clk_num) {
3703 pr_err("%s: invalid clock index %u\n", __func__, idx);
3704 return ERR_PTR(-EINVAL);
3707 return clk_data->clks[idx];
3709 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
3711 struct clk_hw *
3712 of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
3714 struct clk_hw_onecell_data *hw_data = data;
3715 unsigned int idx = clkspec->args[0];
3717 if (idx >= hw_data->num) {
3718 pr_err("%s: invalid index %u\n", __func__, idx);
3719 return ERR_PTR(-EINVAL);
3722 return hw_data->hws[idx];
3724 EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
3727 * of_clk_add_provider() - Register a clock provider for a node
3728 * @np: Device node pointer associated with clock provider
3729 * @clk_src_get: callback for decoding clock
3730 * @data: context pointer for @clk_src_get callback.
3732 int of_clk_add_provider(struct device_node *np,
3733 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
3734 void *data),
3735 void *data)
3737 struct of_clk_provider *cp;
3738 int ret;
3740 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
3741 if (!cp)
3742 return -ENOMEM;
3744 cp->node = of_node_get(np);
3745 cp->data = data;
3746 cp->get = clk_src_get;
3748 mutex_lock(&of_clk_mutex);
3749 list_add(&cp->link, &of_clk_providers);
3750 mutex_unlock(&of_clk_mutex);
3751 pr_debug("Added clock from %pOF\n", np);
3753 ret = of_clk_set_defaults(np, true);
3754 if (ret < 0)
3755 of_clk_del_provider(np);
3757 return ret;
3759 EXPORT_SYMBOL_GPL(of_clk_add_provider);
3762 * of_clk_add_hw_provider() - Register a clock provider for a node
3763 * @np: Device node pointer associated with clock provider
3764 * @get: callback for decoding clk_hw
3765 * @data: context pointer for @get callback.
3767 int of_clk_add_hw_provider(struct device_node *np,
3768 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
3769 void *data),
3770 void *data)
3772 struct of_clk_provider *cp;
3773 int ret;
3775 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
3776 if (!cp)
3777 return -ENOMEM;
3779 cp->node = of_node_get(np);
3780 cp->data = data;
3781 cp->get_hw = get;
3783 mutex_lock(&of_clk_mutex);
3784 list_add(&cp->link, &of_clk_providers);
3785 mutex_unlock(&of_clk_mutex);
3786 pr_debug("Added clk_hw provider from %pOF\n", np);
3788 ret = of_clk_set_defaults(np, true);
3789 if (ret < 0)
3790 of_clk_del_provider(np);
3792 return ret;
3794 EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
3796 static void devm_of_clk_release_provider(struct device *dev, void *res)
3798 of_clk_del_provider(*(struct device_node **)res);
3801 int devm_of_clk_add_hw_provider(struct device *dev,
3802 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
3803 void *data),
3804 void *data)
3806 struct device_node **ptr, *np;
3807 int ret;
3809 ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
3810 GFP_KERNEL);
3811 if (!ptr)
3812 return -ENOMEM;
3814 np = dev->of_node;
3815 ret = of_clk_add_hw_provider(np, get, data);
3816 if (!ret) {
3817 *ptr = np;
3818 devres_add(dev, ptr);
3819 } else {
3820 devres_free(ptr);
3823 return ret;
3825 EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);
3828 * of_clk_del_provider() - Remove a previously registered clock provider
3829 * @np: Device node pointer associated with clock provider
3831 void of_clk_del_provider(struct device_node *np)
3833 struct of_clk_provider *cp;
3835 mutex_lock(&of_clk_mutex);
3836 list_for_each_entry(cp, &of_clk_providers, link) {
3837 if (cp->node == np) {
3838 list_del(&cp->link);
3839 of_node_put(cp->node);
3840 kfree(cp);
3841 break;
3844 mutex_unlock(&of_clk_mutex);
3846 EXPORT_SYMBOL_GPL(of_clk_del_provider);
3848 static int devm_clk_provider_match(struct device *dev, void *res, void *data)
3850 struct device_node **np = res;
3852 if (WARN_ON(!np || !*np))
3853 return 0;
3855 return *np == data;
3858 void devm_of_clk_del_provider(struct device *dev)
3860 int ret;
3862 ret = devres_release(dev, devm_of_clk_release_provider,
3863 devm_clk_provider_match, dev->of_node);
3865 WARN_ON(ret);
3867 EXPORT_SYMBOL(devm_of_clk_del_provider);
3869 static struct clk_hw *
3870 __of_clk_get_hw_from_provider(struct of_clk_provider *provider,
3871 struct of_phandle_args *clkspec)
3873 struct clk *clk;
3875 if (provider->get_hw)
3876 return provider->get_hw(clkspec, provider->data);
3878 clk = provider->get(clkspec, provider->data);
3879 if (IS_ERR(clk))
3880 return ERR_CAST(clk);
3881 return __clk_get_hw(clk);
3884 struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec,
3885 const char *dev_id, const char *con_id)
3887 struct of_clk_provider *provider;
3888 struct clk *clk = ERR_PTR(-EPROBE_DEFER);
3889 struct clk_hw *hw;
3891 if (!clkspec)
3892 return ERR_PTR(-EINVAL);
3894 /* Check if we have such a provider in our array */
3895 mutex_lock(&of_clk_mutex);
3896 list_for_each_entry(provider, &of_clk_providers, link) {
3897 if (provider->node == clkspec->np) {
3898 hw = __of_clk_get_hw_from_provider(provider, clkspec);
3899 clk = __clk_create_clk(hw, dev_id, con_id);
3902 if (!IS_ERR(clk)) {
3903 if (!__clk_get(clk)) {
3904 __clk_free_clk(clk);
3905 clk = ERR_PTR(-ENOENT);
3908 break;
3911 mutex_unlock(&of_clk_mutex);
3913 return clk;
3917 * of_clk_get_from_provider() - Lookup a clock from a clock provider
3918 * @clkspec: pointer to a clock specifier data structure
3920 * This function looks up a struct clk from the registered list of clock
3921 * providers, an input is a clock specifier data structure as returned
3922 * from the of_parse_phandle_with_args() function call.
3924 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
3926 return __of_clk_get_from_provider(clkspec, NULL, __func__);
3928 EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
3931 * of_clk_get_parent_count() - Count the number of clocks a device node has
3932 * @np: device node to count
3934 * Returns: The number of clocks that are possible parents of this node
3936 unsigned int of_clk_get_parent_count(struct device_node *np)
3938 int count;
3940 count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
3941 if (count < 0)
3942 return 0;
3944 return count;
3946 EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
3948 const char *of_clk_get_parent_name(struct device_node *np, int index)
3950 struct of_phandle_args clkspec;
3951 struct property *prop;
3952 const char *clk_name;
3953 const __be32 *vp;
3954 u32 pv;
3955 int rc;
3956 int count;
3957 struct clk *clk;
3959 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
3960 &clkspec);
3961 if (rc)
3962 return NULL;
3964 index = clkspec.args_count ? clkspec.args[0] : 0;
3965 count = 0;
3967 /* if there is an indices property, use it to transfer the index
3968 * specified into an array offset for the clock-output-names property.
3970 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
3971 if (index == pv) {
3972 index = count;
3973 break;
3975 count++;
3977 /* We went off the end of 'clock-indices' without finding it */
3978 if (prop && !vp)
3979 return NULL;
3981 if (of_property_read_string_index(clkspec.np, "clock-output-names",
3982 index,
3983 &clk_name) < 0) {
3985 * Best effort to get the name if the clock has been
3986 * registered with the framework. If the clock isn't
3987 * registered, we return the node name as the name of
3988 * the clock as long as #clock-cells = 0.
3990 clk = of_clk_get_from_provider(&clkspec);
3991 if (IS_ERR(clk)) {
3992 if (clkspec.args_count == 0)
3993 clk_name = clkspec.np->name;
3994 else
3995 clk_name = NULL;
3996 } else {
3997 clk_name = __clk_get_name(clk);
3998 clk_put(clk);
4003 of_node_put(clkspec.np);
4004 return clk_name;
4006 EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
4009 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
4010 * number of parents
4011 * @np: Device node pointer associated with clock provider
4012 * @parents: pointer to char array that hold the parents' names
4013 * @size: size of the @parents array
4015 * Return: number of parents for the clock node.
4017 int of_clk_parent_fill(struct device_node *np, const char **parents,
4018 unsigned int size)
4020 unsigned int i = 0;
4022 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
4023 i++;
4025 return i;
4027 EXPORT_SYMBOL_GPL(of_clk_parent_fill);
4029 struct clock_provider {
4030 void (*clk_init_cb)(struct device_node *);
4031 struct device_node *np;
4032 struct list_head node;
4036 * This function looks for a parent clock. If there is one, then it
4037 * checks that the provider for this parent clock was initialized, in
4038 * this case the parent clock will be ready.
4040 static int parent_ready(struct device_node *np)
4042 int i = 0;
4044 while (true) {
4045 struct clk *clk = of_clk_get(np, i);
4047 /* this parent is ready we can check the next one */
4048 if (!IS_ERR(clk)) {
4049 clk_put(clk);
4050 i++;
4051 continue;
4054 /* at least one parent is not ready, we exit now */
4055 if (PTR_ERR(clk) == -EPROBE_DEFER)
4056 return 0;
4059 * Here we make assumption that the device tree is
4060 * written correctly. So an error means that there is
4061 * no more parent. As we didn't exit yet, then the
4062 * previous parent are ready. If there is no clock
4063 * parent, no need to wait for them, then we can
4064 * consider their absence as being ready
4066 return 1;
4071 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
4072 * @np: Device node pointer associated with clock provider
4073 * @index: clock index
4074 * @flags: pointer to top-level framework flags
4076 * Detects if the clock-critical property exists and, if so, sets the
4077 * corresponding CLK_IS_CRITICAL flag.
4079 * Do not use this function. It exists only for legacy Device Tree
4080 * bindings, such as the one-clock-per-node style that are outdated.
4081 * Those bindings typically put all clock data into .dts and the Linux
4082 * driver has no clock data, thus making it impossible to set this flag
4083 * correctly from the driver. Only those drivers may call
4084 * of_clk_detect_critical from their setup functions.
4086 * Return: error code or zero on success
4088 int of_clk_detect_critical(struct device_node *np,
4089 int index, unsigned long *flags)
4091 struct property *prop;
4092 const __be32 *cur;
4093 uint32_t idx;
4095 if (!np || !flags)
4096 return -EINVAL;
4098 of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
4099 if (index == idx)
4100 *flags |= CLK_IS_CRITICAL;
4102 return 0;
4106 * of_clk_init() - Scan and init clock providers from the DT
4107 * @matches: array of compatible values and init functions for providers.
4109 * This function scans the device tree for matching clock providers
4110 * and calls their initialization functions. It also does it by trying
4111 * to follow the dependencies.
4113 void __init of_clk_init(const struct of_device_id *matches)
4115 const struct of_device_id *match;
4116 struct device_node *np;
4117 struct clock_provider *clk_provider, *next;
4118 bool is_init_done;
4119 bool force = false;
4120 LIST_HEAD(clk_provider_list);
4122 if (!matches)
4123 matches = &__clk_of_table;
4125 /* First prepare the list of the clocks providers */
4126 for_each_matching_node_and_match(np, matches, &match) {
4127 struct clock_provider *parent;
4129 if (!of_device_is_available(np))
4130 continue;
4132 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
4133 if (!parent) {
4134 list_for_each_entry_safe(clk_provider, next,
4135 &clk_provider_list, node) {
4136 list_del(&clk_provider->node);
4137 of_node_put(clk_provider->np);
4138 kfree(clk_provider);
4140 of_node_put(np);
4141 return;
4144 parent->clk_init_cb = match->data;
4145 parent->np = of_node_get(np);
4146 list_add_tail(&parent->node, &clk_provider_list);
4149 while (!list_empty(&clk_provider_list)) {
4150 is_init_done = false;
4151 list_for_each_entry_safe(clk_provider, next,
4152 &clk_provider_list, node) {
4153 if (force || parent_ready(clk_provider->np)) {
4155 /* Don't populate platform devices */
4156 of_node_set_flag(clk_provider->np,
4157 OF_POPULATED);
4159 clk_provider->clk_init_cb(clk_provider->np);
4160 of_clk_set_defaults(clk_provider->np, true);
4162 list_del(&clk_provider->node);
4163 of_node_put(clk_provider->np);
4164 kfree(clk_provider);
4165 is_init_done = true;
4170 * We didn't manage to initialize any of the
4171 * remaining providers during the last loop, so now we
4172 * initialize all the remaining ones unconditionally
4173 * in case the clock parent was not mandatory
4175 if (!is_init_done)
4176 force = true;
4179 #endif