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>
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>
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 static struct hlist_head *all_lists[] = {
49 /*** private data structures ***/
53 const struct clk_ops *ops;
57 struct clk_core *parent;
58 const char **parent_names;
59 struct clk_core **parents;
63 unsigned long req_rate;
64 unsigned long new_rate;
65 struct clk_core *new_parent;
66 struct clk_core *new_child;
69 unsigned int enable_count;
70 unsigned int prepare_count;
71 unsigned int protect_count;
72 unsigned long min_rate;
73 unsigned long max_rate;
74 unsigned long accuracy;
77 struct hlist_head children;
78 struct hlist_node child_node;
79 struct hlist_head clks;
80 unsigned int notifier_count;
81 #ifdef CONFIG_DEBUG_FS
82 struct dentry *dentry;
83 struct hlist_node debug_node;
88 #define CREATE_TRACE_POINTS
89 #include <trace/events/clk.h>
92 struct clk_core *core;
95 unsigned long min_rate;
96 unsigned long max_rate;
97 unsigned int exclusive_count;
98 struct hlist_node clks_node;
102 static int clk_pm_runtime_get(struct clk_core *core)
109 ret = pm_runtime_get_sync(core->dev);
111 pm_runtime_put_noidle(core->dev);
117 static void clk_pm_runtime_put(struct clk_core *core)
122 pm_runtime_put_sync(core->dev);
126 static void clk_prepare_lock(void)
128 if (!mutex_trylock(&prepare_lock)) {
129 if (prepare_owner == current) {
133 mutex_lock(&prepare_lock);
135 WARN_ON_ONCE(prepare_owner != NULL);
136 WARN_ON_ONCE(prepare_refcnt != 0);
137 prepare_owner = current;
141 static void clk_prepare_unlock(void)
143 WARN_ON_ONCE(prepare_owner != current);
144 WARN_ON_ONCE(prepare_refcnt == 0);
146 if (--prepare_refcnt)
148 prepare_owner = NULL;
149 mutex_unlock(&prepare_lock);
152 static unsigned long clk_enable_lock(void)
153 __acquires(enable_lock)
158 * On UP systems, spin_trylock_irqsave() always returns true, even if
159 * we already hold the lock. So, in that case, we rely only on
160 * reference counting.
162 if (!IS_ENABLED(CONFIG_SMP) ||
163 !spin_trylock_irqsave(&enable_lock, flags)) {
164 if (enable_owner == current) {
166 __acquire(enable_lock);
167 if (!IS_ENABLED(CONFIG_SMP))
168 local_save_flags(flags);
171 spin_lock_irqsave(&enable_lock, flags);
173 WARN_ON_ONCE(enable_owner != NULL);
174 WARN_ON_ONCE(enable_refcnt != 0);
175 enable_owner = current;
180 static void clk_enable_unlock(unsigned long flags)
181 __releases(enable_lock)
183 WARN_ON_ONCE(enable_owner != current);
184 WARN_ON_ONCE(enable_refcnt == 0);
186 if (--enable_refcnt) {
187 __release(enable_lock);
191 spin_unlock_irqrestore(&enable_lock, flags);
194 static bool clk_core_rate_is_protected(struct clk_core *core)
196 return core->protect_count;
199 static bool clk_core_is_prepared(struct clk_core *core)
204 * .is_prepared is optional for clocks that can prepare
205 * fall back to software usage counter if it is missing
207 if (!core->ops->is_prepared)
208 return core->prepare_count;
210 if (!clk_pm_runtime_get(core)) {
211 ret = core->ops->is_prepared(core->hw);
212 clk_pm_runtime_put(core);
218 static bool clk_core_is_enabled(struct clk_core *core)
223 * .is_enabled is only mandatory for clocks that gate
224 * fall back to software usage counter if .is_enabled is missing
226 if (!core->ops->is_enabled)
227 return core->enable_count;
230 * Check if clock controller's device is runtime active before
231 * calling .is_enabled callback. If not, assume that clock is
232 * disabled, because we might be called from atomic context, from
233 * which pm_runtime_get() is not allowed.
234 * This function is called mainly from clk_disable_unused_subtree,
235 * which ensures proper runtime pm activation of controller before
236 * taking enable spinlock, but the below check is needed if one tries
237 * to call it from other places.
240 pm_runtime_get_noresume(core->dev);
241 if (!pm_runtime_active(core->dev)) {
248 * This could be called with the enable lock held, or from atomic
249 * context. If the parent isn't enabled already, we can't do
250 * anything here. We can also assume this clock isn't enabled.
252 if ((core->flags & CLK_OPS_PARENT_ENABLE) && core->parent)
253 if (!clk_core_is_enabled(core->parent)) {
258 ret = core->ops->is_enabled(core->hw);
261 pm_runtime_put(core->dev);
266 /*** helper functions ***/
268 const char *__clk_get_name(const struct clk *clk)
270 return !clk ? NULL : clk->core->name;
272 EXPORT_SYMBOL_GPL(__clk_get_name);
274 const char *clk_hw_get_name(const struct clk_hw *hw)
276 return hw->core->name;
278 EXPORT_SYMBOL_GPL(clk_hw_get_name);
280 struct clk_hw *__clk_get_hw(struct clk *clk)
282 return !clk ? NULL : clk->core->hw;
284 EXPORT_SYMBOL_GPL(__clk_get_hw);
286 unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
288 return hw->core->num_parents;
290 EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
292 struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
294 return hw->core->parent ? hw->core->parent->hw : NULL;
296 EXPORT_SYMBOL_GPL(clk_hw_get_parent);
298 static struct clk_core *__clk_lookup_subtree(const char *name,
299 struct clk_core *core)
301 struct clk_core *child;
302 struct clk_core *ret;
304 if (!strcmp(core->name, name))
307 hlist_for_each_entry(child, &core->children, child_node) {
308 ret = __clk_lookup_subtree(name, child);
316 static struct clk_core *clk_core_lookup(const char *name)
318 struct clk_core *root_clk;
319 struct clk_core *ret;
324 /* search the 'proper' clk tree first */
325 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
326 ret = __clk_lookup_subtree(name, root_clk);
331 /* if not found, then search the orphan tree */
332 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
333 ret = __clk_lookup_subtree(name, root_clk);
341 static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
344 if (!core || index >= core->num_parents)
347 if (!core->parents[index])
348 core->parents[index] =
349 clk_core_lookup(core->parent_names[index]);
351 return core->parents[index];
355 clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
357 struct clk_core *parent;
359 parent = clk_core_get_parent_by_index(hw->core, index);
361 return !parent ? NULL : parent->hw;
363 EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
365 unsigned int __clk_get_enable_count(struct clk *clk)
367 return !clk ? 0 : clk->core->enable_count;
370 static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
381 if (!core->num_parents)
391 unsigned long clk_hw_get_rate(const struct clk_hw *hw)
393 return clk_core_get_rate_nolock(hw->core);
395 EXPORT_SYMBOL_GPL(clk_hw_get_rate);
397 static unsigned long __clk_get_accuracy(struct clk_core *core)
402 return core->accuracy;
405 unsigned long __clk_get_flags(struct clk *clk)
407 return !clk ? 0 : clk->core->flags;
409 EXPORT_SYMBOL_GPL(__clk_get_flags);
411 unsigned long clk_hw_get_flags(const struct clk_hw *hw)
413 return hw->core->flags;
415 EXPORT_SYMBOL_GPL(clk_hw_get_flags);
417 bool clk_hw_is_prepared(const struct clk_hw *hw)
419 return clk_core_is_prepared(hw->core);
422 bool clk_hw_rate_is_protected(const struct clk_hw *hw)
424 return clk_core_rate_is_protected(hw->core);
427 bool clk_hw_is_enabled(const struct clk_hw *hw)
429 return clk_core_is_enabled(hw->core);
432 bool __clk_is_enabled(struct clk *clk)
437 return clk_core_is_enabled(clk->core);
439 EXPORT_SYMBOL_GPL(__clk_is_enabled);
441 static bool mux_is_better_rate(unsigned long rate, unsigned long now,
442 unsigned long best, unsigned long flags)
444 if (flags & CLK_MUX_ROUND_CLOSEST)
445 return abs(now - rate) < abs(best - rate);
447 return now <= rate && now > best;
450 int clk_mux_determine_rate_flags(struct clk_hw *hw,
451 struct clk_rate_request *req,
454 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
455 int i, num_parents, ret;
456 unsigned long best = 0;
457 struct clk_rate_request parent_req = *req;
459 /* if NO_REPARENT flag set, pass through to current parent */
460 if (core->flags & CLK_SET_RATE_NO_REPARENT) {
461 parent = core->parent;
462 if (core->flags & CLK_SET_RATE_PARENT) {
463 ret = __clk_determine_rate(parent ? parent->hw : NULL,
468 best = parent_req.rate;
470 best = clk_core_get_rate_nolock(parent);
472 best = clk_core_get_rate_nolock(core);
478 /* find the parent that can provide the fastest rate <= rate */
479 num_parents = core->num_parents;
480 for (i = 0; i < num_parents; i++) {
481 parent = clk_core_get_parent_by_index(core, i);
485 if (core->flags & CLK_SET_RATE_PARENT) {
487 ret = __clk_determine_rate(parent->hw, &parent_req);
491 parent_req.rate = clk_core_get_rate_nolock(parent);
494 if (mux_is_better_rate(req->rate, parent_req.rate,
496 best_parent = parent;
497 best = parent_req.rate;
506 req->best_parent_hw = best_parent->hw;
507 req->best_parent_rate = best;
512 EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);
514 struct clk *__clk_lookup(const char *name)
516 struct clk_core *core = clk_core_lookup(name);
518 return !core ? NULL : core->hw->clk;
521 static void clk_core_get_boundaries(struct clk_core *core,
522 unsigned long *min_rate,
523 unsigned long *max_rate)
525 struct clk *clk_user;
527 *min_rate = core->min_rate;
528 *max_rate = core->max_rate;
530 hlist_for_each_entry(clk_user, &core->clks, clks_node)
531 *min_rate = max(*min_rate, clk_user->min_rate);
533 hlist_for_each_entry(clk_user, &core->clks, clks_node)
534 *max_rate = min(*max_rate, clk_user->max_rate);
537 static bool clk_core_check_boundaries(struct clk_core *core,
538 unsigned long min_rate,
539 unsigned long max_rate)
543 lockdep_assert_held(&prepare_lock);
545 if (min_rate > core->max_rate || max_rate < core->min_rate)
548 hlist_for_each_entry(user, &core->clks, clks_node)
549 if (min_rate > user->max_rate || max_rate < user->min_rate)
555 void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
556 unsigned long max_rate)
558 hw->core->min_rate = min_rate;
559 hw->core->max_rate = max_rate;
561 EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
564 * Helper for finding best parent to provide a given frequency. This can be used
565 * directly as a determine_rate callback (e.g. for a mux), or from a more
566 * complex clock that may combine a mux with other operations.
568 int __clk_mux_determine_rate(struct clk_hw *hw,
569 struct clk_rate_request *req)
571 return clk_mux_determine_rate_flags(hw, req, 0);
573 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
575 int __clk_mux_determine_rate_closest(struct clk_hw *hw,
576 struct clk_rate_request *req)
578 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
580 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
584 static void clk_core_rate_unprotect(struct clk_core *core)
586 lockdep_assert_held(&prepare_lock);
591 if (WARN(core->protect_count == 0,
592 "%s already unprotected\n", core->name))
595 if (--core->protect_count > 0)
598 clk_core_rate_unprotect(core->parent);
601 static int clk_core_rate_nuke_protect(struct clk_core *core)
605 lockdep_assert_held(&prepare_lock);
610 if (core->protect_count == 0)
613 ret = core->protect_count;
614 core->protect_count = 1;
615 clk_core_rate_unprotect(core);
621 * clk_rate_exclusive_put - release exclusivity over clock rate control
622 * @clk: the clk over which the exclusivity is released
624 * clk_rate_exclusive_put() completes a critical section during which a clock
625 * consumer cannot tolerate any other consumer making any operation on the
626 * clock which could result in a rate change or rate glitch. Exclusive clocks
627 * cannot have their rate changed, either directly or indirectly due to changes
628 * further up the parent chain of clocks. As a result, clocks up parent chain
629 * also get under exclusive control of the calling consumer.
631 * If exlusivity is claimed more than once on clock, even by the same consumer,
632 * the rate effectively gets locked as exclusivity can't be preempted.
634 * Calls to clk_rate_exclusive_put() must be balanced with calls to
635 * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
638 void clk_rate_exclusive_put(struct clk *clk)
646 * if there is something wrong with this consumer protect count, stop
647 * here before messing with the provider
649 if (WARN_ON(clk->exclusive_count <= 0))
652 clk_core_rate_unprotect(clk->core);
653 clk->exclusive_count--;
655 clk_prepare_unlock();
657 EXPORT_SYMBOL_GPL(clk_rate_exclusive_put);
659 static void clk_core_rate_protect(struct clk_core *core)
661 lockdep_assert_held(&prepare_lock);
666 if (core->protect_count == 0)
667 clk_core_rate_protect(core->parent);
669 core->protect_count++;
672 static void clk_core_rate_restore_protect(struct clk_core *core, int count)
674 lockdep_assert_held(&prepare_lock);
682 clk_core_rate_protect(core);
683 core->protect_count = count;
687 * clk_rate_exclusive_get - get exclusivity over the clk rate control
688 * @clk: the clk over which the exclusity of rate control is requested
690 * clk_rate_exlusive_get() begins a critical section during which a clock
691 * consumer cannot tolerate any other consumer making any operation on the
692 * clock which could result in a rate change or rate glitch. Exclusive clocks
693 * cannot have their rate changed, either directly or indirectly due to changes
694 * further up the parent chain of clocks. As a result, clocks up parent chain
695 * also get under exclusive control of the calling consumer.
697 * If exlusivity is claimed more than once on clock, even by the same consumer,
698 * the rate effectively gets locked as exclusivity can't be preempted.
700 * Calls to clk_rate_exclusive_get() should be balanced with calls to
701 * clk_rate_exclusive_put(). Calls to this function may sleep.
702 * Returns 0 on success, -EERROR otherwise
704 int clk_rate_exclusive_get(struct clk *clk)
710 clk_core_rate_protect(clk->core);
711 clk->exclusive_count++;
712 clk_prepare_unlock();
716 EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
718 static void clk_core_unprepare(struct clk_core *core)
720 lockdep_assert_held(&prepare_lock);
725 if (WARN(core->prepare_count == 0,
726 "%s already unprepared\n", core->name))
729 if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL,
730 "Unpreparing critical %s\n", core->name))
733 if (core->flags & CLK_SET_RATE_GATE)
734 clk_core_rate_unprotect(core);
736 if (--core->prepare_count > 0)
739 WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);
741 trace_clk_unprepare(core);
743 if (core->ops->unprepare)
744 core->ops->unprepare(core->hw);
746 trace_clk_unprepare_complete(core);
747 clk_core_unprepare(core->parent);
748 clk_pm_runtime_put(core);
751 static void clk_core_unprepare_lock(struct clk_core *core)
754 clk_core_unprepare(core);
755 clk_prepare_unlock();
759 * clk_unprepare - undo preparation of a clock source
760 * @clk: the clk being unprepared
762 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
763 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
764 * if the operation may sleep. One example is a clk which is accessed over
765 * I2c. In the complex case a clk gate operation may require a fast and a slow
766 * part. It is this reason that clk_unprepare and clk_disable are not mutually
767 * exclusive. In fact clk_disable must be called before clk_unprepare.
769 void clk_unprepare(struct clk *clk)
771 if (IS_ERR_OR_NULL(clk))
774 clk_core_unprepare_lock(clk->core);
776 EXPORT_SYMBOL_GPL(clk_unprepare);
778 static int clk_core_prepare(struct clk_core *core)
782 lockdep_assert_held(&prepare_lock);
787 if (core->prepare_count == 0) {
788 ret = clk_pm_runtime_get(core);
792 ret = clk_core_prepare(core->parent);
796 trace_clk_prepare(core);
798 if (core->ops->prepare)
799 ret = core->ops->prepare(core->hw);
801 trace_clk_prepare_complete(core);
807 core->prepare_count++;
810 * CLK_SET_RATE_GATE is a special case of clock protection
811 * Instead of a consumer claiming exclusive rate control, it is
812 * actually the provider which prevents any consumer from making any
813 * operation which could result in a rate change or rate glitch while
814 * the clock is prepared.
816 if (core->flags & CLK_SET_RATE_GATE)
817 clk_core_rate_protect(core);
821 clk_core_unprepare(core->parent);
823 clk_pm_runtime_put(core);
827 static int clk_core_prepare_lock(struct clk_core *core)
832 ret = clk_core_prepare(core);
833 clk_prepare_unlock();
839 * clk_prepare - prepare a clock source
840 * @clk: the clk being prepared
842 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
843 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
844 * operation may sleep. One example is a clk which is accessed over I2c. In
845 * the complex case a clk ungate operation may require a fast and a slow part.
846 * It is this reason that clk_prepare and clk_enable are not mutually
847 * exclusive. In fact clk_prepare must be called before clk_enable.
848 * Returns 0 on success, -EERROR otherwise.
850 int clk_prepare(struct clk *clk)
855 return clk_core_prepare_lock(clk->core);
857 EXPORT_SYMBOL_GPL(clk_prepare);
859 static void clk_core_disable(struct clk_core *core)
861 lockdep_assert_held(&enable_lock);
866 if (WARN(core->enable_count == 0, "%s already disabled\n", core->name))
869 if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL,
870 "Disabling critical %s\n", core->name))
873 if (--core->enable_count > 0)
876 trace_clk_disable_rcuidle(core);
878 if (core->ops->disable)
879 core->ops->disable(core->hw);
881 trace_clk_disable_complete_rcuidle(core);
883 clk_core_disable(core->parent);
886 static void clk_core_disable_lock(struct clk_core *core)
890 flags = clk_enable_lock();
891 clk_core_disable(core);
892 clk_enable_unlock(flags);
896 * clk_disable - gate a clock
897 * @clk: the clk being gated
899 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
900 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
901 * clk if the operation is fast and will never sleep. One example is a
902 * SoC-internal clk which is controlled via simple register writes. In the
903 * complex case a clk gate operation may require a fast and a slow part. It is
904 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
905 * In fact clk_disable must be called before clk_unprepare.
907 void clk_disable(struct clk *clk)
909 if (IS_ERR_OR_NULL(clk))
912 clk_core_disable_lock(clk->core);
914 EXPORT_SYMBOL_GPL(clk_disable);
916 static int clk_core_enable(struct clk_core *core)
920 lockdep_assert_held(&enable_lock);
925 if (WARN(core->prepare_count == 0,
926 "Enabling unprepared %s\n", core->name))
929 if (core->enable_count == 0) {
930 ret = clk_core_enable(core->parent);
935 trace_clk_enable_rcuidle(core);
937 if (core->ops->enable)
938 ret = core->ops->enable(core->hw);
940 trace_clk_enable_complete_rcuidle(core);
943 clk_core_disable(core->parent);
948 core->enable_count++;
952 static int clk_core_enable_lock(struct clk_core *core)
957 flags = clk_enable_lock();
958 ret = clk_core_enable(core);
959 clk_enable_unlock(flags);
965 * clk_enable - ungate a clock
966 * @clk: the clk being ungated
968 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
969 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
970 * if the operation will never sleep. One example is a SoC-internal clk which
971 * is controlled via simple register writes. In the complex case a clk ungate
972 * operation may require a fast and a slow part. It is this reason that
973 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
974 * must be called before clk_enable. Returns 0 on success, -EERROR
977 int clk_enable(struct clk *clk)
982 return clk_core_enable_lock(clk->core);
984 EXPORT_SYMBOL_GPL(clk_enable);
986 static int clk_core_prepare_enable(struct clk_core *core)
990 ret = clk_core_prepare_lock(core);
994 ret = clk_core_enable_lock(core);
996 clk_core_unprepare_lock(core);
1001 static void clk_core_disable_unprepare(struct clk_core *core)
1003 clk_core_disable_lock(core);
1004 clk_core_unprepare_lock(core);
1007 static void clk_unprepare_unused_subtree(struct clk_core *core)
1009 struct clk_core *child;
1011 lockdep_assert_held(&prepare_lock);
1013 hlist_for_each_entry(child, &core->children, child_node)
1014 clk_unprepare_unused_subtree(child);
1016 if (core->prepare_count)
1019 if (core->flags & CLK_IGNORE_UNUSED)
1022 if (clk_pm_runtime_get(core))
1025 if (clk_core_is_prepared(core)) {
1026 trace_clk_unprepare(core);
1027 if (core->ops->unprepare_unused)
1028 core->ops->unprepare_unused(core->hw);
1029 else if (core->ops->unprepare)
1030 core->ops->unprepare(core->hw);
1031 trace_clk_unprepare_complete(core);
1034 clk_pm_runtime_put(core);
1037 static void clk_disable_unused_subtree(struct clk_core *core)
1039 struct clk_core *child;
1040 unsigned long flags;
1042 lockdep_assert_held(&prepare_lock);
1044 hlist_for_each_entry(child, &core->children, child_node)
1045 clk_disable_unused_subtree(child);
1047 if (core->flags & CLK_OPS_PARENT_ENABLE)
1048 clk_core_prepare_enable(core->parent);
1050 if (clk_pm_runtime_get(core))
1053 flags = clk_enable_lock();
1055 if (core->enable_count)
1058 if (core->flags & CLK_IGNORE_UNUSED)
1062 * some gate clocks have special needs during the disable-unused
1063 * sequence. call .disable_unused if available, otherwise fall
1066 if (clk_core_is_enabled(core)) {
1067 trace_clk_disable(core);
1068 if (core->ops->disable_unused)
1069 core->ops->disable_unused(core->hw);
1070 else if (core->ops->disable)
1071 core->ops->disable(core->hw);
1072 trace_clk_disable_complete(core);
1076 clk_enable_unlock(flags);
1077 clk_pm_runtime_put(core);
1079 if (core->flags & CLK_OPS_PARENT_ENABLE)
1080 clk_core_disable_unprepare(core->parent);
1083 static bool clk_ignore_unused;
1084 static int __init clk_ignore_unused_setup(char *__unused)
1086 clk_ignore_unused = true;
1089 __setup("clk_ignore_unused", clk_ignore_unused_setup);
1091 static int clk_disable_unused(void)
1093 struct clk_core *core;
1095 if (clk_ignore_unused) {
1096 pr_warn("clk: Not disabling unused clocks\n");
1102 hlist_for_each_entry(core, &clk_root_list, child_node)
1103 clk_disable_unused_subtree(core);
1105 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1106 clk_disable_unused_subtree(core);
1108 hlist_for_each_entry(core, &clk_root_list, child_node)
1109 clk_unprepare_unused_subtree(core);
1111 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1112 clk_unprepare_unused_subtree(core);
1114 clk_prepare_unlock();
1118 late_initcall_sync(clk_disable_unused);
1120 static int clk_core_determine_round_nolock(struct clk_core *core,
1121 struct clk_rate_request *req)
1125 lockdep_assert_held(&prepare_lock);
1131 * At this point, core protection will be disabled if
1132 * - if the provider is not protected at all
1133 * - if the calling consumer is the only one which has exclusivity
1136 if (clk_core_rate_is_protected(core)) {
1137 req->rate = core->rate;
1138 } else if (core->ops->determine_rate) {
1139 return core->ops->determine_rate(core->hw, req);
1140 } else if (core->ops->round_rate) {
1141 rate = core->ops->round_rate(core->hw, req->rate,
1142 &req->best_parent_rate);
1154 static void clk_core_init_rate_req(struct clk_core * const core,
1155 struct clk_rate_request *req)
1157 struct clk_core *parent;
1159 if (WARN_ON(!core || !req))
1162 parent = core->parent;
1164 req->best_parent_hw = parent->hw;
1165 req->best_parent_rate = parent->rate;
1167 req->best_parent_hw = NULL;
1168 req->best_parent_rate = 0;
1172 static bool clk_core_can_round(struct clk_core * const core)
1174 if (core->ops->determine_rate || core->ops->round_rate)
1180 static int clk_core_round_rate_nolock(struct clk_core *core,
1181 struct clk_rate_request *req)
1183 lockdep_assert_held(&prepare_lock);
1190 clk_core_init_rate_req(core, req);
1192 if (clk_core_can_round(core))
1193 return clk_core_determine_round_nolock(core, req);
1194 else if (core->flags & CLK_SET_RATE_PARENT)
1195 return clk_core_round_rate_nolock(core->parent, req);
1197 req->rate = core->rate;
1202 * __clk_determine_rate - get the closest rate actually supported by a clock
1203 * @hw: determine the rate of this clock
1204 * @req: target rate request
1206 * Useful for clk_ops such as .set_rate and .determine_rate.
1208 int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
1215 return clk_core_round_rate_nolock(hw->core, req);
1217 EXPORT_SYMBOL_GPL(__clk_determine_rate);
1219 unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
1222 struct clk_rate_request req;
1224 clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate);
1227 ret = clk_core_round_rate_nolock(hw->core, &req);
1233 EXPORT_SYMBOL_GPL(clk_hw_round_rate);
1236 * clk_round_rate - round the given rate for a clk
1237 * @clk: the clk for which we are rounding a rate
1238 * @rate: the rate which is to be rounded
1240 * Takes in a rate as input and rounds it to a rate that the clk can actually
1241 * use which is then returned. If clk doesn't support round_rate operation
1242 * then the parent rate is returned.
1244 long clk_round_rate(struct clk *clk, unsigned long rate)
1246 struct clk_rate_request req;
1254 if (clk->exclusive_count)
1255 clk_core_rate_unprotect(clk->core);
1257 clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
1260 ret = clk_core_round_rate_nolock(clk->core, &req);
1262 if (clk->exclusive_count)
1263 clk_core_rate_protect(clk->core);
1265 clk_prepare_unlock();
1272 EXPORT_SYMBOL_GPL(clk_round_rate);
1275 * __clk_notify - call clk notifier chain
1276 * @core: clk that is changing rate
1277 * @msg: clk notifier type (see include/linux/clk.h)
1278 * @old_rate: old clk rate
1279 * @new_rate: new clk rate
1281 * Triggers a notifier call chain on the clk rate-change notification
1282 * for 'clk'. Passes a pointer to the struct clk and the previous
1283 * and current rates to the notifier callback. Intended to be called by
1284 * internal clock code only. Returns NOTIFY_DONE from the last driver
1285 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1286 * a driver returns that.
1288 static int __clk_notify(struct clk_core *core, unsigned long msg,
1289 unsigned long old_rate, unsigned long new_rate)
1291 struct clk_notifier *cn;
1292 struct clk_notifier_data cnd;
1293 int ret = NOTIFY_DONE;
1295 cnd.old_rate = old_rate;
1296 cnd.new_rate = new_rate;
1298 list_for_each_entry(cn, &clk_notifier_list, node) {
1299 if (cn->clk->core == core) {
1301 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
1303 if (ret & NOTIFY_STOP_MASK)
1312 * __clk_recalc_accuracies
1313 * @core: first clk in the subtree
1315 * Walks the subtree of clks starting with clk and recalculates accuracies as
1316 * it goes. Note that if a clk does not implement the .recalc_accuracy
1317 * callback then it is assumed that the clock will take on the accuracy of its
1320 static void __clk_recalc_accuracies(struct clk_core *core)
1322 unsigned long parent_accuracy = 0;
1323 struct clk_core *child;
1325 lockdep_assert_held(&prepare_lock);
1328 parent_accuracy = core->parent->accuracy;
1330 if (core->ops->recalc_accuracy)
1331 core->accuracy = core->ops->recalc_accuracy(core->hw,
1334 core->accuracy = parent_accuracy;
1336 hlist_for_each_entry(child, &core->children, child_node)
1337 __clk_recalc_accuracies(child);
1340 static long clk_core_get_accuracy(struct clk_core *core)
1342 unsigned long accuracy;
1345 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
1346 __clk_recalc_accuracies(core);
1348 accuracy = __clk_get_accuracy(core);
1349 clk_prepare_unlock();
1355 * clk_get_accuracy - return the accuracy of clk
1356 * @clk: the clk whose accuracy is being returned
1358 * Simply returns the cached accuracy of the clk, unless
1359 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1361 * If clk is NULL then returns 0.
1363 long clk_get_accuracy(struct clk *clk)
1368 return clk_core_get_accuracy(clk->core);
1370 EXPORT_SYMBOL_GPL(clk_get_accuracy);
1372 static unsigned long clk_recalc(struct clk_core *core,
1373 unsigned long parent_rate)
1375 unsigned long rate = parent_rate;
1377 if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
1378 rate = core->ops->recalc_rate(core->hw, parent_rate);
1379 clk_pm_runtime_put(core);
1385 * __clk_recalc_rates
1386 * @core: first clk in the subtree
1387 * @msg: notification type (see include/linux/clk.h)
1389 * Walks the subtree of clks starting with clk and recalculates rates as it
1390 * goes. Note that if a clk does not implement the .recalc_rate callback then
1391 * it is assumed that the clock will take on the rate of its parent.
1393 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1396 static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
1398 unsigned long old_rate;
1399 unsigned long parent_rate = 0;
1400 struct clk_core *child;
1402 lockdep_assert_held(&prepare_lock);
1404 old_rate = core->rate;
1407 parent_rate = core->parent->rate;
1409 core->rate = clk_recalc(core, parent_rate);
1412 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1413 * & ABORT_RATE_CHANGE notifiers
1415 if (core->notifier_count && msg)
1416 __clk_notify(core, msg, old_rate, core->rate);
1418 hlist_for_each_entry(child, &core->children, child_node)
1419 __clk_recalc_rates(child, msg);
1422 static unsigned long clk_core_get_rate(struct clk_core *core)
1428 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1429 __clk_recalc_rates(core, 0);
1431 rate = clk_core_get_rate_nolock(core);
1432 clk_prepare_unlock();
1438 * clk_get_rate - return the rate of clk
1439 * @clk: the clk whose rate is being returned
1441 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1442 * is set, which means a recalc_rate will be issued.
1443 * If clk is NULL then returns 0.
1445 unsigned long clk_get_rate(struct clk *clk)
1450 return clk_core_get_rate(clk->core);
1452 EXPORT_SYMBOL_GPL(clk_get_rate);
1454 static int clk_fetch_parent_index(struct clk_core *core,
1455 struct clk_core *parent)
1462 for (i = 0; i < core->num_parents; i++)
1463 if (clk_core_get_parent_by_index(core, i) == parent)
1470 * Update the orphan status of @core and all its children.
1472 static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
1474 struct clk_core *child;
1476 core->orphan = is_orphan;
1478 hlist_for_each_entry(child, &core->children, child_node)
1479 clk_core_update_orphan_status(child, is_orphan);
1482 static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1484 bool was_orphan = core->orphan;
1486 hlist_del(&core->child_node);
1489 bool becomes_orphan = new_parent->orphan;
1491 /* avoid duplicate POST_RATE_CHANGE notifications */
1492 if (new_parent->new_child == core)
1493 new_parent->new_child = NULL;
1495 hlist_add_head(&core->child_node, &new_parent->children);
1497 if (was_orphan != becomes_orphan)
1498 clk_core_update_orphan_status(core, becomes_orphan);
1500 hlist_add_head(&core->child_node, &clk_orphan_list);
1502 clk_core_update_orphan_status(core, true);
1505 core->parent = new_parent;
1508 static struct clk_core *__clk_set_parent_before(struct clk_core *core,
1509 struct clk_core *parent)
1511 unsigned long flags;
1512 struct clk_core *old_parent = core->parent;
1515 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
1517 * 2. Migrate prepare state between parents and prevent race with
1520 * If the clock is not prepared, then a race with
1521 * clk_enable/disable() is impossible since we already have the
1522 * prepare lock (future calls to clk_enable() need to be preceded by
1525 * If the clock is prepared, migrate the prepared state to the new
1526 * parent and also protect against a race with clk_enable() by
1527 * forcing the clock and the new parent on. This ensures that all
1528 * future calls to clk_enable() are practically NOPs with respect to
1529 * hardware and software states.
1531 * See also: Comment for clk_set_parent() below.
1534 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
1535 if (core->flags & CLK_OPS_PARENT_ENABLE) {
1536 clk_core_prepare_enable(old_parent);
1537 clk_core_prepare_enable(parent);
1540 /* migrate prepare count if > 0 */
1541 if (core->prepare_count) {
1542 clk_core_prepare_enable(parent);
1543 clk_core_enable_lock(core);
1546 /* update the clk tree topology */
1547 flags = clk_enable_lock();
1548 clk_reparent(core, parent);
1549 clk_enable_unlock(flags);
1554 static void __clk_set_parent_after(struct clk_core *core,
1555 struct clk_core *parent,
1556 struct clk_core *old_parent)
1559 * Finish the migration of prepare state and undo the changes done
1560 * for preventing a race with clk_enable().
1562 if (core->prepare_count) {
1563 clk_core_disable_lock(core);
1564 clk_core_disable_unprepare(old_parent);
1567 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
1568 if (core->flags & CLK_OPS_PARENT_ENABLE) {
1569 clk_core_disable_unprepare(parent);
1570 clk_core_disable_unprepare(old_parent);
1574 static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
1577 unsigned long flags;
1579 struct clk_core *old_parent;
1581 old_parent = __clk_set_parent_before(core, parent);
1583 trace_clk_set_parent(core, parent);
1585 /* change clock input source */
1586 if (parent && core->ops->set_parent)
1587 ret = core->ops->set_parent(core->hw, p_index);
1589 trace_clk_set_parent_complete(core, parent);
1592 flags = clk_enable_lock();
1593 clk_reparent(core, old_parent);
1594 clk_enable_unlock(flags);
1595 __clk_set_parent_after(core, old_parent, parent);
1600 __clk_set_parent_after(core, parent, old_parent);
1606 * __clk_speculate_rates
1607 * @core: first clk in the subtree
1608 * @parent_rate: the "future" rate of clk's parent
1610 * Walks the subtree of clks starting with clk, speculating rates as it
1611 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1613 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1614 * pre-rate change notifications and returns early if no clks in the
1615 * subtree have subscribed to the notifications. Note that if a clk does not
1616 * implement the .recalc_rate callback then it is assumed that the clock will
1617 * take on the rate of its parent.
1619 static int __clk_speculate_rates(struct clk_core *core,
1620 unsigned long parent_rate)
1622 struct clk_core *child;
1623 unsigned long new_rate;
1624 int ret = NOTIFY_DONE;
1626 lockdep_assert_held(&prepare_lock);
1628 new_rate = clk_recalc(core, parent_rate);
1630 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1631 if (core->notifier_count)
1632 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
1634 if (ret & NOTIFY_STOP_MASK) {
1635 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1636 __func__, core->name, ret);
1640 hlist_for_each_entry(child, &core->children, child_node) {
1641 ret = __clk_speculate_rates(child, new_rate);
1642 if (ret & NOTIFY_STOP_MASK)
1650 static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
1651 struct clk_core *new_parent, u8 p_index)
1653 struct clk_core *child;
1655 core->new_rate = new_rate;
1656 core->new_parent = new_parent;
1657 core->new_parent_index = p_index;
1658 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1659 core->new_child = NULL;
1660 if (new_parent && new_parent != core->parent)
1661 new_parent->new_child = core;
1663 hlist_for_each_entry(child, &core->children, child_node) {
1664 child->new_rate = clk_recalc(child, new_rate);
1665 clk_calc_subtree(child, child->new_rate, NULL, 0);
1670 * calculate the new rates returning the topmost clock that has to be
1673 static struct clk_core *clk_calc_new_rates(struct clk_core *core,
1676 struct clk_core *top = core;
1677 struct clk_core *old_parent, *parent;
1678 unsigned long best_parent_rate = 0;
1679 unsigned long new_rate;
1680 unsigned long min_rate;
1681 unsigned long max_rate;
1686 if (IS_ERR_OR_NULL(core))
1689 /* save parent rate, if it exists */
1690 parent = old_parent = core->parent;
1692 best_parent_rate = parent->rate;
1694 clk_core_get_boundaries(core, &min_rate, &max_rate);
1696 /* find the closest rate and parent clk/rate */
1697 if (clk_core_can_round(core)) {
1698 struct clk_rate_request req;
1701 req.min_rate = min_rate;
1702 req.max_rate = max_rate;
1704 clk_core_init_rate_req(core, &req);
1706 ret = clk_core_determine_round_nolock(core, &req);
1710 best_parent_rate = req.best_parent_rate;
1711 new_rate = req.rate;
1712 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
1714 if (new_rate < min_rate || new_rate > max_rate)
1716 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
1717 /* pass-through clock without adjustable parent */
1718 core->new_rate = core->rate;
1721 /* pass-through clock with adjustable parent */
1722 top = clk_calc_new_rates(parent, rate);
1723 new_rate = parent->new_rate;
1727 /* some clocks must be gated to change parent */
1728 if (parent != old_parent &&
1729 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1730 pr_debug("%s: %s not gated but wants to reparent\n",
1731 __func__, core->name);
1735 /* try finding the new parent index */
1736 if (parent && core->num_parents > 1) {
1737 p_index = clk_fetch_parent_index(core, parent);
1739 pr_debug("%s: clk %s can not be parent of clk %s\n",
1740 __func__, parent->name, core->name);
1745 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
1746 best_parent_rate != parent->rate)
1747 top = clk_calc_new_rates(parent, best_parent_rate);
1750 clk_calc_subtree(core, new_rate, parent, p_index);
1756 * Notify about rate changes in a subtree. Always walk down the whole tree
1757 * so that in case of an error we can walk down the whole tree again and
1760 static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
1761 unsigned long event)
1763 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
1764 int ret = NOTIFY_DONE;
1766 if (core->rate == core->new_rate)
1769 if (core->notifier_count) {
1770 ret = __clk_notify(core, event, core->rate, core->new_rate);
1771 if (ret & NOTIFY_STOP_MASK)
1775 hlist_for_each_entry(child, &core->children, child_node) {
1776 /* Skip children who will be reparented to another clock */
1777 if (child->new_parent && child->new_parent != core)
1779 tmp_clk = clk_propagate_rate_change(child, event);
1784 /* handle the new child who might not be in core->children yet */
1785 if (core->new_child) {
1786 tmp_clk = clk_propagate_rate_change(core->new_child, event);
1795 * walk down a subtree and set the new rates notifying the rate
1798 static void clk_change_rate(struct clk_core *core)
1800 struct clk_core *child;
1801 struct hlist_node *tmp;
1802 unsigned long old_rate;
1803 unsigned long best_parent_rate = 0;
1804 bool skip_set_rate = false;
1805 struct clk_core *old_parent;
1806 struct clk_core *parent = NULL;
1808 old_rate = core->rate;
1810 if (core->new_parent) {
1811 parent = core->new_parent;
1812 best_parent_rate = core->new_parent->rate;
1813 } else if (core->parent) {
1814 parent = core->parent;
1815 best_parent_rate = core->parent->rate;
1818 if (clk_pm_runtime_get(core))
1821 if (core->flags & CLK_SET_RATE_UNGATE) {
1822 unsigned long flags;
1824 clk_core_prepare(core);
1825 flags = clk_enable_lock();
1826 clk_core_enable(core);
1827 clk_enable_unlock(flags);
1830 if (core->new_parent && core->new_parent != core->parent) {
1831 old_parent = __clk_set_parent_before(core, core->new_parent);
1832 trace_clk_set_parent(core, core->new_parent);
1834 if (core->ops->set_rate_and_parent) {
1835 skip_set_rate = true;
1836 core->ops->set_rate_and_parent(core->hw, core->new_rate,
1838 core->new_parent_index);
1839 } else if (core->ops->set_parent) {
1840 core->ops->set_parent(core->hw, core->new_parent_index);
1843 trace_clk_set_parent_complete(core, core->new_parent);
1844 __clk_set_parent_after(core, core->new_parent, old_parent);
1847 if (core->flags & CLK_OPS_PARENT_ENABLE)
1848 clk_core_prepare_enable(parent);
1850 trace_clk_set_rate(core, core->new_rate);
1852 if (!skip_set_rate && core->ops->set_rate)
1853 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
1855 trace_clk_set_rate_complete(core, core->new_rate);
1857 core->rate = clk_recalc(core, best_parent_rate);
1859 if (core->flags & CLK_SET_RATE_UNGATE) {
1860 unsigned long flags;
1862 flags = clk_enable_lock();
1863 clk_core_disable(core);
1864 clk_enable_unlock(flags);
1865 clk_core_unprepare(core);
1868 if (core->flags & CLK_OPS_PARENT_ENABLE)
1869 clk_core_disable_unprepare(parent);
1871 if (core->notifier_count && old_rate != core->rate)
1872 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
1874 if (core->flags & CLK_RECALC_NEW_RATES)
1875 (void)clk_calc_new_rates(core, core->new_rate);
1878 * Use safe iteration, as change_rate can actually swap parents
1879 * for certain clock types.
1881 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
1882 /* Skip children who will be reparented to another clock */
1883 if (child->new_parent && child->new_parent != core)
1885 clk_change_rate(child);
1888 /* handle the new child who might not be in core->children yet */
1889 if (core->new_child)
1890 clk_change_rate(core->new_child);
1892 clk_pm_runtime_put(core);
1895 static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
1896 unsigned long req_rate)
1899 struct clk_rate_request req;
1901 lockdep_assert_held(&prepare_lock);
1906 /* simulate what the rate would be if it could be freely set */
1907 cnt = clk_core_rate_nuke_protect(core);
1911 clk_core_get_boundaries(core, &req.min_rate, &req.max_rate);
1912 req.rate = req_rate;
1914 ret = clk_core_round_rate_nolock(core, &req);
1916 /* restore the protection */
1917 clk_core_rate_restore_protect(core, cnt);
1919 return ret ? 0 : req.rate;
1922 static int clk_core_set_rate_nolock(struct clk_core *core,
1923 unsigned long req_rate)
1925 struct clk_core *top, *fail_clk;
1932 rate = clk_core_req_round_rate_nolock(core, req_rate);
1934 /* bail early if nothing to do */
1935 if (rate == clk_core_get_rate_nolock(core))
1938 /* fail on a direct rate set of a protected provider */
1939 if (clk_core_rate_is_protected(core))
1942 /* calculate new rates and get the topmost changed clock */
1943 top = clk_calc_new_rates(core, req_rate);
1947 ret = clk_pm_runtime_get(core);
1951 /* notify that we are about to change rates */
1952 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
1954 pr_debug("%s: failed to set %s rate\n", __func__,
1956 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
1961 /* change the rates */
1962 clk_change_rate(top);
1964 core->req_rate = req_rate;
1966 clk_pm_runtime_put(core);
1972 * clk_set_rate - specify a new rate for clk
1973 * @clk: the clk whose rate is being changed
1974 * @rate: the new rate for clk
1976 * In the simplest case clk_set_rate will only adjust the rate of clk.
1978 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1979 * propagate up to clk's parent; whether or not this happens depends on the
1980 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1981 * after calling .round_rate then upstream parent propagation is ignored. If
1982 * *parent_rate comes back with a new rate for clk's parent then we propagate
1983 * up to clk's parent and set its rate. Upward propagation will continue
1984 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1985 * .round_rate stops requesting changes to clk's parent_rate.
1987 * Rate changes are accomplished via tree traversal that also recalculates the
1988 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
1990 * Returns 0 on success, -EERROR otherwise.
1992 int clk_set_rate(struct clk *clk, unsigned long rate)
1999 /* prevent racing with updates to the clock topology */
2002 if (clk->exclusive_count)
2003 clk_core_rate_unprotect(clk->core);
2005 ret = clk_core_set_rate_nolock(clk->core, rate);
2007 if (clk->exclusive_count)
2008 clk_core_rate_protect(clk->core);
2010 clk_prepare_unlock();
2014 EXPORT_SYMBOL_GPL(clk_set_rate);
2017 * clk_set_rate_exclusive - specify a new rate get exclusive control
2018 * @clk: the clk whose rate is being changed
2019 * @rate: the new rate for clk
2021 * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
2022 * within a critical section
2024 * This can be used initially to ensure that at least 1 consumer is
2025 * statisfied when several consumers are competing for exclusivity over the
2026 * same clock provider.
2028 * The exclusivity is not applied if setting the rate failed.
2030 * Calls to clk_rate_exclusive_get() should be balanced with calls to
2031 * clk_rate_exclusive_put().
2033 * Returns 0 on success, -EERROR otherwise.
2035 int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
2042 /* prevent racing with updates to the clock topology */
2046 * The temporary protection removal is not here, on purpose
2047 * This function is meant to be used instead of clk_rate_protect,
2048 * so before the consumer code path protect the clock provider
2051 ret = clk_core_set_rate_nolock(clk->core, rate);
2053 clk_core_rate_protect(clk->core);
2054 clk->exclusive_count++;
2057 clk_prepare_unlock();
2061 EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
2064 * clk_set_rate_range - set a rate range for a clock source
2065 * @clk: clock source
2066 * @min: desired minimum clock rate in Hz, inclusive
2067 * @max: desired maximum clock rate in Hz, inclusive
2069 * Returns success (0) or negative errno.
2071 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
2074 unsigned long old_min, old_max, rate;
2080 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
2081 __func__, clk->core->name, clk->dev_id, clk->con_id,
2088 if (clk->exclusive_count)
2089 clk_core_rate_unprotect(clk->core);
2091 /* Save the current values in case we need to rollback the change */
2092 old_min = clk->min_rate;
2093 old_max = clk->max_rate;
2094 clk->min_rate = min;
2095 clk->max_rate = max;
2097 if (!clk_core_check_boundaries(clk->core, min, max)) {
2102 rate = clk_core_get_rate_nolock(clk->core);
2103 if (rate < min || rate > max) {
2106 * We are in bit of trouble here, current rate is outside the
2107 * the requested range. We are going try to request appropriate
2108 * range boundary but there is a catch. It may fail for the
2109 * usual reason (clock broken, clock protected, etc) but also
2111 * - round_rate() was not favorable and fell on the wrong
2112 * side of the boundary
2113 * - the determine_rate() callback does not really check for
2114 * this corner case when determining the rate
2122 ret = clk_core_set_rate_nolock(clk->core, rate);
2124 /* rollback the changes */
2125 clk->min_rate = old_min;
2126 clk->max_rate = old_max;
2131 if (clk->exclusive_count)
2132 clk_core_rate_protect(clk->core);
2134 clk_prepare_unlock();
2138 EXPORT_SYMBOL_GPL(clk_set_rate_range);
2141 * clk_set_min_rate - set a minimum clock rate for a clock source
2142 * @clk: clock source
2143 * @rate: desired minimum clock rate in Hz, inclusive
2145 * Returns success (0) or negative errno.
2147 int clk_set_min_rate(struct clk *clk, unsigned long rate)
2152 return clk_set_rate_range(clk, rate, clk->max_rate);
2154 EXPORT_SYMBOL_GPL(clk_set_min_rate);
2157 * clk_set_max_rate - set a maximum clock rate for a clock source
2158 * @clk: clock source
2159 * @rate: desired maximum clock rate in Hz, inclusive
2161 * Returns success (0) or negative errno.
2163 int clk_set_max_rate(struct clk *clk, unsigned long rate)
2168 return clk_set_rate_range(clk, clk->min_rate, rate);
2170 EXPORT_SYMBOL_GPL(clk_set_max_rate);
2173 * clk_get_parent - return the parent of a clk
2174 * @clk: the clk whose parent gets returned
2176 * Simply returns clk->parent. Returns NULL if clk is NULL.
2178 struct clk *clk_get_parent(struct clk *clk)
2186 /* TODO: Create a per-user clk and change callers to call clk_put */
2187 parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
2188 clk_prepare_unlock();
2192 EXPORT_SYMBOL_GPL(clk_get_parent);
2194 static struct clk_core *__clk_init_parent(struct clk_core *core)
2198 if (core->num_parents > 1 && core->ops->get_parent)
2199 index = core->ops->get_parent(core->hw);
2201 return clk_core_get_parent_by_index(core, index);
2204 static void clk_core_reparent(struct clk_core *core,
2205 struct clk_core *new_parent)
2207 clk_reparent(core, new_parent);
2208 __clk_recalc_accuracies(core);
2209 __clk_recalc_rates(core, POST_RATE_CHANGE);
2212 void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
2217 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
2221 * clk_has_parent - check if a clock is a possible parent for another
2222 * @clk: clock source
2223 * @parent: parent clock source
2225 * This function can be used in drivers that need to check that a clock can be
2226 * the parent of another without actually changing the parent.
2228 * Returns true if @parent is a possible parent for @clk, false otherwise.
2230 bool clk_has_parent(struct clk *clk, struct clk *parent)
2232 struct clk_core *core, *parent_core;
2234 /* NULL clocks should be nops, so return success if either is NULL. */
2235 if (!clk || !parent)
2239 parent_core = parent->core;
2241 /* Optimize for the case where the parent is already the parent. */
2242 if (core->parent == parent_core)
2245 return match_string(core->parent_names, core->num_parents,
2246 parent_core->name) >= 0;
2248 EXPORT_SYMBOL_GPL(clk_has_parent);
2250 static int clk_core_set_parent_nolock(struct clk_core *core,
2251 struct clk_core *parent)
2255 unsigned long p_rate = 0;
2257 lockdep_assert_held(&prepare_lock);
2262 if (core->parent == parent)
2265 /* verify ops for for multi-parent clks */
2266 if (core->num_parents > 1 && !core->ops->set_parent)
2269 /* check that we are allowed to re-parent if the clock is in use */
2270 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
2273 if (clk_core_rate_is_protected(core))
2276 /* try finding the new parent index */
2278 p_index = clk_fetch_parent_index(core, parent);
2280 pr_debug("%s: clk %s can not be parent of clk %s\n",
2281 __func__, parent->name, core->name);
2284 p_rate = parent->rate;
2287 ret = clk_pm_runtime_get(core);
2291 /* propagate PRE_RATE_CHANGE notifications */
2292 ret = __clk_speculate_rates(core, p_rate);
2294 /* abort if a driver objects */
2295 if (ret & NOTIFY_STOP_MASK)
2298 /* do the re-parent */
2299 ret = __clk_set_parent(core, parent, p_index);
2301 /* propagate rate an accuracy recalculation accordingly */
2303 __clk_recalc_rates(core, ABORT_RATE_CHANGE);
2305 __clk_recalc_rates(core, POST_RATE_CHANGE);
2306 __clk_recalc_accuracies(core);
2310 clk_pm_runtime_put(core);
2316 * clk_set_parent - switch the parent of a mux clk
2317 * @clk: the mux clk whose input we are switching
2318 * @parent: the new input to clk
2320 * Re-parent clk to use parent as its new input source. If clk is in
2321 * prepared state, the clk will get enabled for the duration of this call. If
2322 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2323 * that, the reparenting is glitchy in hardware, etc), use the
2324 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2326 * After successfully changing clk's parent clk_set_parent will update the
2327 * clk topology, sysfs topology and propagate rate recalculation via
2328 * __clk_recalc_rates.
2330 * Returns 0 on success, -EERROR otherwise.
2332 int clk_set_parent(struct clk *clk, struct clk *parent)
2341 if (clk->exclusive_count)
2342 clk_core_rate_unprotect(clk->core);
2344 ret = clk_core_set_parent_nolock(clk->core,
2345 parent ? parent->core : NULL);
2347 if (clk->exclusive_count)
2348 clk_core_rate_protect(clk->core);
2350 clk_prepare_unlock();
2354 EXPORT_SYMBOL_GPL(clk_set_parent);
2356 static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
2360 lockdep_assert_held(&prepare_lock);
2365 if (clk_core_rate_is_protected(core))
2368 trace_clk_set_phase(core, degrees);
2370 if (core->ops->set_phase) {
2371 ret = core->ops->set_phase(core->hw, degrees);
2373 core->phase = degrees;
2376 trace_clk_set_phase_complete(core, degrees);
2382 * clk_set_phase - adjust the phase shift of a clock signal
2383 * @clk: clock signal source
2384 * @degrees: number of degrees the signal is shifted
2386 * Shifts the phase of a clock signal by the specified
2387 * degrees. Returns 0 on success, -EERROR otherwise.
2389 * This function makes no distinction about the input or reference
2390 * signal that we adjust the clock signal phase against. For example
2391 * phase locked-loop clock signal generators we may shift phase with
2392 * respect to feedback clock signal input, but for other cases the
2393 * clock phase may be shifted with respect to some other, unspecified
2396 * Additionally the concept of phase shift does not propagate through
2397 * the clock tree hierarchy, which sets it apart from clock rates and
2398 * clock accuracy. A parent clock phase attribute does not have an
2399 * impact on the phase attribute of a child clock.
2401 int clk_set_phase(struct clk *clk, int degrees)
2408 /* sanity check degrees */
2415 if (clk->exclusive_count)
2416 clk_core_rate_unprotect(clk->core);
2418 ret = clk_core_set_phase_nolock(clk->core, degrees);
2420 if (clk->exclusive_count)
2421 clk_core_rate_protect(clk->core);
2423 clk_prepare_unlock();
2427 EXPORT_SYMBOL_GPL(clk_set_phase);
2429 static int clk_core_get_phase(struct clk_core *core)
2434 /* Always try to update cached phase if possible */
2435 if (core->ops->get_phase)
2436 core->phase = core->ops->get_phase(core->hw);
2438 clk_prepare_unlock();
2444 * clk_get_phase - return the phase shift of a clock signal
2445 * @clk: clock signal source
2447 * Returns the phase shift of a clock node in degrees, otherwise returns
2450 int clk_get_phase(struct clk *clk)
2455 return clk_core_get_phase(clk->core);
2457 EXPORT_SYMBOL_GPL(clk_get_phase);
2459 static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
2461 /* Assume a default value of 50% */
2466 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);
2468 static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
2470 struct clk_duty *duty = &core->duty;
2473 if (!core->ops->get_duty_cycle)
2474 return clk_core_update_duty_cycle_parent_nolock(core);
2476 ret = core->ops->get_duty_cycle(core->hw, duty);
2480 /* Don't trust the clock provider too much */
2481 if (duty->den == 0 || duty->num > duty->den) {
2489 clk_core_reset_duty_cycle_nolock(core);
2493 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
2498 core->flags & CLK_DUTY_CYCLE_PARENT) {
2499 ret = clk_core_update_duty_cycle_nolock(core->parent);
2500 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
2502 clk_core_reset_duty_cycle_nolock(core);
2508 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
2509 struct clk_duty *duty);
2511 static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
2512 struct clk_duty *duty)
2516 lockdep_assert_held(&prepare_lock);
2518 if (clk_core_rate_is_protected(core))
2521 trace_clk_set_duty_cycle(core, duty);
2523 if (!core->ops->set_duty_cycle)
2524 return clk_core_set_duty_cycle_parent_nolock(core, duty);
2526 ret = core->ops->set_duty_cycle(core->hw, duty);
2528 memcpy(&core->duty, duty, sizeof(*duty));
2530 trace_clk_set_duty_cycle_complete(core, duty);
2535 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
2536 struct clk_duty *duty)
2541 core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
2542 ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
2543 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
2550 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
2551 * @clk: clock signal source
2552 * @num: numerator of the duty cycle ratio to be applied
2553 * @den: denominator of the duty cycle ratio to be applied
2555 * Apply the duty cycle ratio if the ratio is valid and the clock can
2556 * perform this operation
2558 * Returns (0) on success, a negative errno otherwise.
2560 int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
2563 struct clk_duty duty;
2568 /* sanity check the ratio */
2569 if (den == 0 || num > den)
2577 if (clk->exclusive_count)
2578 clk_core_rate_unprotect(clk->core);
2580 ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
2582 if (clk->exclusive_count)
2583 clk_core_rate_protect(clk->core);
2585 clk_prepare_unlock();
2589 EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
2591 static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
2594 struct clk_duty *duty = &core->duty;
2599 ret = clk_core_update_duty_cycle_nolock(core);
2601 ret = mult_frac(scale, duty->num, duty->den);
2603 clk_prepare_unlock();
2609 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
2610 * @clk: clock signal source
2611 * @scale: scaling factor to be applied to represent the ratio as an integer
2613 * Returns the duty cycle ratio of a clock node multiplied by the provided
2614 * scaling factor, or negative errno on error.
2616 int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
2621 return clk_core_get_scaled_duty_cycle(clk->core, scale);
2623 EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
2626 * clk_is_match - check if two clk's point to the same hardware clock
2627 * @p: clk compared against q
2628 * @q: clk compared against p
2630 * Returns true if the two struct clk pointers both point to the same hardware
2631 * clock node. Put differently, returns true if struct clk *p and struct clk *q
2632 * share the same struct clk_core object.
2634 * Returns false otherwise. Note that two NULL clks are treated as matching.
2636 bool clk_is_match(const struct clk *p, const struct clk *q)
2638 /* trivial case: identical struct clk's or both NULL */
2642 /* true if clk->core pointers match. Avoid dereferencing garbage */
2643 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
2644 if (p->core == q->core)
2649 EXPORT_SYMBOL_GPL(clk_is_match);
2651 /*** debugfs support ***/
2653 #ifdef CONFIG_DEBUG_FS
2654 #include <linux/debugfs.h>
2656 static struct dentry *rootdir;
2657 static int inited = 0;
2658 static DEFINE_MUTEX(clk_debug_lock);
2659 static HLIST_HEAD(clk_debug_list);
2661 static struct hlist_head *orphan_list[] = {
2666 static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
2672 seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu %5d %6d\n",
2674 30 - level * 3, c->name,
2675 c->enable_count, c->prepare_count, c->protect_count,
2676 clk_core_get_rate(c), clk_core_get_accuracy(c),
2677 clk_core_get_phase(c),
2678 clk_core_get_scaled_duty_cycle(c, 100000));
2681 static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
2684 struct clk_core *child;
2689 clk_summary_show_one(s, c, level);
2691 hlist_for_each_entry(child, &c->children, child_node)
2692 clk_summary_show_subtree(s, child, level + 1);
2695 static int clk_summary_show(struct seq_file *s, void *data)
2698 struct hlist_head **lists = (struct hlist_head **)s->private;
2700 seq_puts(s, " enable prepare protect duty\n");
2701 seq_puts(s, " clock count count count rate accuracy phase cycle\n");
2702 seq_puts(s, "---------------------------------------------------------------------------------------------\n");
2706 for (; *lists; lists++)
2707 hlist_for_each_entry(c, *lists, child_node)
2708 clk_summary_show_subtree(s, c, 0);
2710 clk_prepare_unlock();
2714 DEFINE_SHOW_ATTRIBUTE(clk_summary);
2716 static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
2721 /* This should be JSON format, i.e. elements separated with a comma */
2722 seq_printf(s, "\"%s\": { ", c->name);
2723 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
2724 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
2725 seq_printf(s, "\"protect_count\": %d,", c->protect_count);
2726 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate(c));
2727 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c));
2728 seq_printf(s, "\"phase\": %d,", clk_core_get_phase(c));
2729 seq_printf(s, "\"duty_cycle\": %u",
2730 clk_core_get_scaled_duty_cycle(c, 100000));
2733 static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
2735 struct clk_core *child;
2740 clk_dump_one(s, c, level);
2742 hlist_for_each_entry(child, &c->children, child_node) {
2744 clk_dump_subtree(s, child, level + 1);
2750 static int clk_dump_show(struct seq_file *s, void *data)
2753 bool first_node = true;
2754 struct hlist_head **lists = (struct hlist_head **)s->private;
2759 for (; *lists; lists++) {
2760 hlist_for_each_entry(c, *lists, child_node) {
2764 clk_dump_subtree(s, c, 0);
2768 clk_prepare_unlock();
2773 DEFINE_SHOW_ATTRIBUTE(clk_dump);
2775 static const struct {
2779 #define ENTRY(f) { f, #f }
2780 ENTRY(CLK_SET_RATE_GATE),
2781 ENTRY(CLK_SET_PARENT_GATE),
2782 ENTRY(CLK_SET_RATE_PARENT),
2783 ENTRY(CLK_IGNORE_UNUSED),
2784 ENTRY(CLK_IS_BASIC),
2785 ENTRY(CLK_GET_RATE_NOCACHE),
2786 ENTRY(CLK_SET_RATE_NO_REPARENT),
2787 ENTRY(CLK_GET_ACCURACY_NOCACHE),
2788 ENTRY(CLK_RECALC_NEW_RATES),
2789 ENTRY(CLK_SET_RATE_UNGATE),
2790 ENTRY(CLK_IS_CRITICAL),
2791 ENTRY(CLK_OPS_PARENT_ENABLE),
2792 ENTRY(CLK_DUTY_CYCLE_PARENT),
2796 static int clk_flags_show(struct seq_file *s, void *data)
2798 struct clk_core *core = s->private;
2799 unsigned long flags = core->flags;
2802 for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
2803 if (flags & clk_flags[i].flag) {
2804 seq_printf(s, "%s\n", clk_flags[i].name);
2805 flags &= ~clk_flags[i].flag;
2810 seq_printf(s, "0x%lx\n", flags);
2815 DEFINE_SHOW_ATTRIBUTE(clk_flags);
2817 static int possible_parents_show(struct seq_file *s, void *data)
2819 struct clk_core *core = s->private;
2822 for (i = 0; i < core->num_parents - 1; i++)
2823 seq_printf(s, "%s ", core->parent_names[i]);
2825 seq_printf(s, "%s\n", core->parent_names[i]);
2829 DEFINE_SHOW_ATTRIBUTE(possible_parents);
2831 static int clk_duty_cycle_show(struct seq_file *s, void *data)
2833 struct clk_core *core = s->private;
2834 struct clk_duty *duty = &core->duty;
2836 seq_printf(s, "%u/%u\n", duty->num, duty->den);
2840 DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
2842 static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
2844 struct dentry *root;
2846 if (!core || !pdentry)
2849 root = debugfs_create_dir(core->name, pdentry);
2850 core->dentry = root;
2852 debugfs_create_ulong("clk_rate", 0444, root, &core->rate);
2853 debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
2854 debugfs_create_u32("clk_phase", 0444, root, &core->phase);
2855 debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
2856 debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
2857 debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
2858 debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
2859 debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
2860 debugfs_create_file("clk_duty_cycle", 0444, root, core,
2861 &clk_duty_cycle_fops);
2863 if (core->num_parents > 1)
2864 debugfs_create_file("clk_possible_parents", 0444, root, core,
2865 &possible_parents_fops);
2867 if (core->ops->debug_init)
2868 core->ops->debug_init(core->hw, core->dentry);
2872 * clk_debug_register - add a clk node to the debugfs clk directory
2873 * @core: the clk being added to the debugfs clk directory
2875 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
2876 * initialized. Otherwise it bails out early since the debugfs clk directory
2877 * will be created lazily by clk_debug_init as part of a late_initcall.
2879 static void clk_debug_register(struct clk_core *core)
2881 mutex_lock(&clk_debug_lock);
2882 hlist_add_head(&core->debug_node, &clk_debug_list);
2884 clk_debug_create_one(core, rootdir);
2885 mutex_unlock(&clk_debug_lock);
2889 * clk_debug_unregister - remove a clk node from the debugfs clk directory
2890 * @core: the clk being removed from the debugfs clk directory
2892 * Dynamically removes a clk and all its child nodes from the
2893 * debugfs clk directory if clk->dentry points to debugfs created by
2894 * clk_debug_register in __clk_core_init.
2896 static void clk_debug_unregister(struct clk_core *core)
2898 mutex_lock(&clk_debug_lock);
2899 hlist_del_init(&core->debug_node);
2900 debugfs_remove_recursive(core->dentry);
2901 core->dentry = NULL;
2902 mutex_unlock(&clk_debug_lock);
2906 * clk_debug_init - lazily populate the debugfs clk directory
2908 * clks are often initialized very early during boot before memory can be
2909 * dynamically allocated and well before debugfs is setup. This function
2910 * populates the debugfs clk directory once at boot-time when we know that
2911 * debugfs is setup. It should only be called once at boot-time, all other clks
2912 * added dynamically will be done so with clk_debug_register.
2914 static int __init clk_debug_init(void)
2916 struct clk_core *core;
2918 rootdir = debugfs_create_dir("clk", NULL);
2920 debugfs_create_file("clk_summary", 0444, rootdir, &all_lists,
2922 debugfs_create_file("clk_dump", 0444, rootdir, &all_lists,
2924 debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list,
2926 debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list,
2929 mutex_lock(&clk_debug_lock);
2930 hlist_for_each_entry(core, &clk_debug_list, debug_node)
2931 clk_debug_create_one(core, rootdir);
2934 mutex_unlock(&clk_debug_lock);
2938 late_initcall(clk_debug_init);
2940 static inline void clk_debug_register(struct clk_core *core) { }
2941 static inline void clk_debug_reparent(struct clk_core *core,
2942 struct clk_core *new_parent)
2945 static inline void clk_debug_unregister(struct clk_core *core)
2951 * __clk_core_init - initialize the data structures in a struct clk_core
2952 * @core: clk_core being initialized
2954 * Initializes the lists in struct clk_core, queries the hardware for the
2955 * parent and rate and sets them both.
2957 static int __clk_core_init(struct clk_core *core)
2960 struct clk_core *orphan;
2961 struct hlist_node *tmp2;
2969 ret = clk_pm_runtime_get(core);
2973 /* check to see if a clock with this name is already registered */
2974 if (clk_core_lookup(core->name)) {
2975 pr_debug("%s: clk %s already initialized\n",
2976 __func__, core->name);
2981 /* check that clk_ops are sane. See Documentation/driver-api/clk.rst */
2982 if (core->ops->set_rate &&
2983 !((core->ops->round_rate || core->ops->determine_rate) &&
2984 core->ops->recalc_rate)) {
2985 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
2986 __func__, core->name);
2991 if (core->ops->set_parent && !core->ops->get_parent) {
2992 pr_err("%s: %s must implement .get_parent & .set_parent\n",
2993 __func__, core->name);
2998 if (core->num_parents > 1 && !core->ops->get_parent) {
2999 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
3000 __func__, core->name);
3005 if (core->ops->set_rate_and_parent &&
3006 !(core->ops->set_parent && core->ops->set_rate)) {
3007 pr_err("%s: %s must implement .set_parent & .set_rate\n",
3008 __func__, core->name);
3013 /* throw a WARN if any entries in parent_names are NULL */
3014 for (i = 0; i < core->num_parents; i++)
3015 WARN(!core->parent_names[i],
3016 "%s: invalid NULL in %s's .parent_names\n",
3017 __func__, core->name);
3019 core->parent = __clk_init_parent(core);
3022 * Populate core->parent if parent has already been clk_core_init'd. If
3023 * parent has not yet been clk_core_init'd then place clk in the orphan
3024 * list. If clk doesn't have any parents then place it in the root
3027 * Every time a new clk is clk_init'd then we walk the list of orphan
3028 * clocks and re-parent any that are children of the clock currently
3032 hlist_add_head(&core->child_node,
3033 &core->parent->children);
3034 core->orphan = core->parent->orphan;
3035 } else if (!core->num_parents) {
3036 hlist_add_head(&core->child_node, &clk_root_list);
3037 core->orphan = false;
3039 hlist_add_head(&core->child_node, &clk_orphan_list);
3040 core->orphan = true;
3044 * optional platform-specific magic
3046 * The .init callback is not used by any of the basic clock types, but
3047 * exists for weird hardware that must perform initialization magic.
3048 * Please consider other ways of solving initialization problems before
3049 * using this callback, as its use is discouraged.
3051 if (core->ops->init)
3052 core->ops->init(core->hw);
3055 * Set clk's accuracy. The preferred method is to use
3056 * .recalc_accuracy. For simple clocks and lazy developers the default
3057 * fallback is to use the parent's accuracy. If a clock doesn't have a
3058 * parent (or is orphaned) then accuracy is set to zero (perfect
3061 if (core->ops->recalc_accuracy)
3062 core->accuracy = core->ops->recalc_accuracy(core->hw,
3063 __clk_get_accuracy(core->parent));
3064 else if (core->parent)
3065 core->accuracy = core->parent->accuracy;
3071 * Since a phase is by definition relative to its parent, just
3072 * query the current clock phase, or just assume it's in phase.
3074 if (core->ops->get_phase)
3075 core->phase = core->ops->get_phase(core->hw);
3080 * Set clk's duty cycle.
3082 clk_core_update_duty_cycle_nolock(core);
3085 * Set clk's rate. The preferred method is to use .recalc_rate. For
3086 * simple clocks and lazy developers the default fallback is to use the
3087 * parent's rate. If a clock doesn't have a parent (or is orphaned)
3088 * then rate is set to zero.
3090 if (core->ops->recalc_rate)
3091 rate = core->ops->recalc_rate(core->hw,
3092 clk_core_get_rate_nolock(core->parent));
3093 else if (core->parent)
3094 rate = core->parent->rate;
3097 core->rate = core->req_rate = rate;
3100 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
3101 * don't get accidentally disabled when walking the orphan tree and
3102 * reparenting clocks
3104 if (core->flags & CLK_IS_CRITICAL) {
3105 unsigned long flags;
3107 ret = clk_core_prepare(core);
3111 flags = clk_enable_lock();
3112 ret = clk_core_enable(core);
3113 clk_enable_unlock(flags);
3115 clk_core_unprepare(core);
3121 * walk the list of orphan clocks and reparent any that newly finds a
3124 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
3125 struct clk_core *parent = __clk_init_parent(orphan);
3128 * We need to use __clk_set_parent_before() and _after() to
3129 * to properly migrate any prepare/enable count of the orphan
3130 * clock. This is important for CLK_IS_CRITICAL clocks, which
3131 * are enabled during init but might not have a parent yet.
3134 /* update the clk tree topology */
3135 __clk_set_parent_before(orphan, parent);
3136 __clk_set_parent_after(orphan, parent, NULL);
3137 __clk_recalc_accuracies(orphan);
3138 __clk_recalc_rates(orphan, 0);
3142 kref_init(&core->ref);
3144 clk_pm_runtime_put(core);
3147 hlist_del_init(&core->child_node);
3149 clk_prepare_unlock();
3152 clk_debug_register(core);
3157 struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,
3162 /* This is to allow this function to be chained to others */
3163 if (IS_ERR_OR_NULL(hw))
3164 return ERR_CAST(hw);
3166 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
3168 return ERR_PTR(-ENOMEM);
3170 clk->core = hw->core;
3171 clk->dev_id = dev_id;
3172 clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
3173 clk->max_rate = ULONG_MAX;
3176 hlist_add_head(&clk->clks_node, &hw->core->clks);
3177 clk_prepare_unlock();
3182 /* keep in sync with __clk_put */
3183 void __clk_free_clk(struct clk *clk)
3186 hlist_del(&clk->clks_node);
3187 clk_prepare_unlock();
3189 kfree_const(clk->con_id);
3194 * clk_register - allocate a new clock, register it and return an opaque cookie
3195 * @dev: device that is registering this clock
3196 * @hw: link to hardware-specific clock data
3198 * clk_register is the primary interface for populating the clock tree with new
3199 * clock nodes. It returns a pointer to the newly allocated struct clk which
3200 * cannot be dereferenced by driver code but may be used in conjunction with the
3201 * rest of the clock API. In the event of an error clk_register will return an
3202 * error code; drivers must test for an error code after calling clk_register.
3204 struct clk *clk_register(struct device *dev, struct clk_hw *hw)
3207 struct clk_core *core;
3209 core = kzalloc(sizeof(*core), GFP_KERNEL);
3215 core->name = kstrdup_const(hw->init->name, GFP_KERNEL);
3221 if (WARN_ON(!hw->init->ops)) {
3225 core->ops = hw->init->ops;
3227 if (dev && pm_runtime_enabled(dev))
3229 if (dev && dev->driver)
3230 core->owner = dev->driver->owner;
3232 core->flags = hw->init->flags;
3233 core->num_parents = hw->init->num_parents;
3235 core->max_rate = ULONG_MAX;
3238 /* allocate local copy in case parent_names is __initdata */
3239 core->parent_names = kcalloc(core->num_parents, sizeof(char *),
3242 if (!core->parent_names) {
3244 goto fail_parent_names;
3248 /* copy each string name in case parent_names is __initdata */
3249 for (i = 0; i < core->num_parents; i++) {
3250 core->parent_names[i] = kstrdup_const(hw->init->parent_names[i],
3252 if (!core->parent_names[i]) {
3254 goto fail_parent_names_copy;
3258 /* avoid unnecessary string look-ups of clk_core's possible parents. */
3259 core->parents = kcalloc(core->num_parents, sizeof(*core->parents),
3261 if (!core->parents) {
3266 INIT_HLIST_HEAD(&core->clks);
3268 hw->clk = __clk_create_clk(hw, NULL, NULL);
3269 if (IS_ERR(hw->clk)) {
3270 ret = PTR_ERR(hw->clk);
3274 ret = __clk_core_init(core);
3278 __clk_free_clk(hw->clk);
3282 kfree(core->parents);
3283 fail_parent_names_copy:
3285 kfree_const(core->parent_names[i]);
3286 kfree(core->parent_names);
3289 kfree_const(core->name);
3293 return ERR_PTR(ret);
3295 EXPORT_SYMBOL_GPL(clk_register);
3298 * clk_hw_register - register a clk_hw and return an error code
3299 * @dev: device that is registering this clock
3300 * @hw: link to hardware-specific clock data
3302 * clk_hw_register is the primary interface for populating the clock tree with
3303 * new clock nodes. It returns an integer equal to zero indicating success or
3304 * less than zero indicating failure. Drivers must test for an error code after
3305 * calling clk_hw_register().
3307 int clk_hw_register(struct device *dev, struct clk_hw *hw)
3309 return PTR_ERR_OR_ZERO(clk_register(dev, hw));
3311 EXPORT_SYMBOL_GPL(clk_hw_register);
3313 /* Free memory allocated for a clock. */
3314 static void __clk_release(struct kref *ref)
3316 struct clk_core *core = container_of(ref, struct clk_core, ref);
3317 int i = core->num_parents;
3319 lockdep_assert_held(&prepare_lock);
3321 kfree(core->parents);
3323 kfree_const(core->parent_names[i]);
3325 kfree(core->parent_names);
3326 kfree_const(core->name);
3331 * Empty clk_ops for unregistered clocks. These are used temporarily
3332 * after clk_unregister() was called on a clock and until last clock
3333 * consumer calls clk_put() and the struct clk object is freed.
3335 static int clk_nodrv_prepare_enable(struct clk_hw *hw)
3340 static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
3345 static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
3346 unsigned long parent_rate)
3351 static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
3356 static const struct clk_ops clk_nodrv_ops = {
3357 .enable = clk_nodrv_prepare_enable,
3358 .disable = clk_nodrv_disable_unprepare,
3359 .prepare = clk_nodrv_prepare_enable,
3360 .unprepare = clk_nodrv_disable_unprepare,
3361 .set_rate = clk_nodrv_set_rate,
3362 .set_parent = clk_nodrv_set_parent,
3365 static void clk_core_evict_parent_cache_subtree(struct clk_core *root,
3366 struct clk_core *target)
3369 struct clk_core *child;
3371 for (i = 0; i < root->num_parents; i++)
3372 if (root->parents[i] == target)
3373 root->parents[i] = NULL;
3375 hlist_for_each_entry(child, &root->children, child_node)
3376 clk_core_evict_parent_cache_subtree(child, target);
3379 /* Remove this clk from all parent caches */
3380 static void clk_core_evict_parent_cache(struct clk_core *core)
3382 struct hlist_head **lists;
3383 struct clk_core *root;
3385 lockdep_assert_held(&prepare_lock);
3387 for (lists = all_lists; *lists; lists++)
3388 hlist_for_each_entry(root, *lists, child_node)
3389 clk_core_evict_parent_cache_subtree(root, core);
3394 * clk_unregister - unregister a currently registered clock
3395 * @clk: clock to unregister
3397 void clk_unregister(struct clk *clk)
3399 unsigned long flags;
3401 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
3404 clk_debug_unregister(clk->core);
3408 if (clk->core->ops == &clk_nodrv_ops) {
3409 pr_err("%s: unregistered clock: %s\n", __func__,
3414 * Assign empty clock ops for consumers that might still hold
3415 * a reference to this clock.
3417 flags = clk_enable_lock();
3418 clk->core->ops = &clk_nodrv_ops;
3419 clk_enable_unlock(flags);
3421 if (!hlist_empty(&clk->core->children)) {
3422 struct clk_core *child;
3423 struct hlist_node *t;
3425 /* Reparent all children to the orphan list. */
3426 hlist_for_each_entry_safe(child, t, &clk->core->children,
3428 clk_core_set_parent_nolock(child, NULL);
3431 clk_core_evict_parent_cache(clk->core);
3433 hlist_del_init(&clk->core->child_node);
3435 if (clk->core->prepare_count)
3436 pr_warn("%s: unregistering prepared clock: %s\n",
3437 __func__, clk->core->name);
3439 if (clk->core->protect_count)
3440 pr_warn("%s: unregistering protected clock: %s\n",
3441 __func__, clk->core->name);
3443 kref_put(&clk->core->ref, __clk_release);
3445 clk_prepare_unlock();
3447 EXPORT_SYMBOL_GPL(clk_unregister);
3450 * clk_hw_unregister - unregister a currently registered clk_hw
3451 * @hw: hardware-specific clock data to unregister
3453 void clk_hw_unregister(struct clk_hw *hw)
3455 clk_unregister(hw->clk);
3457 EXPORT_SYMBOL_GPL(clk_hw_unregister);
3459 static void devm_clk_release(struct device *dev, void *res)
3461 clk_unregister(*(struct clk **)res);
3464 static void devm_clk_hw_release(struct device *dev, void *res)
3466 clk_hw_unregister(*(struct clk_hw **)res);
3470 * devm_clk_register - resource managed clk_register()
3471 * @dev: device that is registering this clock
3472 * @hw: link to hardware-specific clock data
3474 * Managed clk_register(). Clocks returned from this function are
3475 * automatically clk_unregister()ed on driver detach. See clk_register() for
3478 struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
3483 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
3485 return ERR_PTR(-ENOMEM);
3487 clk = clk_register(dev, hw);
3490 devres_add(dev, clkp);
3497 EXPORT_SYMBOL_GPL(devm_clk_register);
3500 * devm_clk_hw_register - resource managed clk_hw_register()
3501 * @dev: device that is registering this clock
3502 * @hw: link to hardware-specific clock data
3504 * Managed clk_hw_register(). Clocks registered by this function are
3505 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
3506 * for more information.
3508 int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
3510 struct clk_hw **hwp;
3513 hwp = devres_alloc(devm_clk_hw_release, sizeof(*hwp), GFP_KERNEL);
3517 ret = clk_hw_register(dev, hw);
3520 devres_add(dev, hwp);
3527 EXPORT_SYMBOL_GPL(devm_clk_hw_register);
3529 static int devm_clk_match(struct device *dev, void *res, void *data)
3531 struct clk *c = res;
3537 static int devm_clk_hw_match(struct device *dev, void *res, void *data)
3539 struct clk_hw *hw = res;
3547 * devm_clk_unregister - resource managed clk_unregister()
3548 * @clk: clock to unregister
3550 * Deallocate a clock allocated with devm_clk_register(). Normally
3551 * this function will not need to be called and the resource management
3552 * code will ensure that the resource is freed.
3554 void devm_clk_unregister(struct device *dev, struct clk *clk)
3556 WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
3558 EXPORT_SYMBOL_GPL(devm_clk_unregister);
3561 * devm_clk_hw_unregister - resource managed clk_hw_unregister()
3562 * @dev: device that is unregistering the hardware-specific clock data
3563 * @hw: link to hardware-specific clock data
3565 * Unregister a clk_hw registered with devm_clk_hw_register(). Normally
3566 * this function will not need to be called and the resource management
3567 * code will ensure that the resource is freed.
3569 void devm_clk_hw_unregister(struct device *dev, struct clk_hw *hw)
3571 WARN_ON(devres_release(dev, devm_clk_hw_release, devm_clk_hw_match,
3574 EXPORT_SYMBOL_GPL(devm_clk_hw_unregister);
3579 int __clk_get(struct clk *clk)
3581 struct clk_core *core = !clk ? NULL : clk->core;
3584 if (!try_module_get(core->owner))
3587 kref_get(&core->ref);
3592 /* keep in sync with __clk_free_clk */
3593 void __clk_put(struct clk *clk)
3595 struct module *owner;
3597 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
3603 * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
3604 * given user should be balanced with calls to clk_rate_exclusive_put()
3605 * and by that same consumer
3607 if (WARN_ON(clk->exclusive_count)) {
3608 /* We voiced our concern, let's sanitize the situation */
3609 clk->core->protect_count -= (clk->exclusive_count - 1);
3610 clk_core_rate_unprotect(clk->core);
3611 clk->exclusive_count = 0;
3614 hlist_del(&clk->clks_node);
3615 if (clk->min_rate > clk->core->req_rate ||
3616 clk->max_rate < clk->core->req_rate)
3617 clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
3619 owner = clk->core->owner;
3620 kref_put(&clk->core->ref, __clk_release);
3622 clk_prepare_unlock();
3626 kfree_const(clk->con_id);
3630 /*** clk rate change notifiers ***/
3633 * clk_notifier_register - add a clk rate change notifier
3634 * @clk: struct clk * to watch
3635 * @nb: struct notifier_block * with callback info
3637 * Request notification when clk's rate changes. This uses an SRCU
3638 * notifier because we want it to block and notifier unregistrations are
3639 * uncommon. The callbacks associated with the notifier must not
3640 * re-enter into the clk framework by calling any top-level clk APIs;
3641 * this will cause a nested prepare_lock mutex.
3643 * In all notification cases (pre, post and abort rate change) the original
3644 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
3645 * and the new frequency is passed via struct clk_notifier_data.new_rate.
3647 * clk_notifier_register() must be called from non-atomic context.
3648 * Returns -EINVAL if called with null arguments, -ENOMEM upon
3649 * allocation failure; otherwise, passes along the return value of
3650 * srcu_notifier_chain_register().
3652 int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
3654 struct clk_notifier *cn;
3662 /* search the list of notifiers for this clk */
3663 list_for_each_entry(cn, &clk_notifier_list, node)
3667 /* if clk wasn't in the notifier list, allocate new clk_notifier */
3668 cn = kzalloc(sizeof(*cn), GFP_KERNEL);
3673 srcu_init_notifier_head(&cn->notifier_head);
3675 list_add(&cn->node, &clk_notifier_list);
3678 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
3680 clk->core->notifier_count++;
3683 clk_prepare_unlock();
3687 EXPORT_SYMBOL_GPL(clk_notifier_register);
3690 * clk_notifier_unregister - remove a clk rate change notifier
3691 * @clk: struct clk *
3692 * @nb: struct notifier_block * with callback info
3694 * Request no further notification for changes to 'clk' and frees memory
3695 * allocated in clk_notifier_register.
3697 * Returns -EINVAL if called with null arguments; otherwise, passes
3698 * along the return value of srcu_notifier_chain_unregister().
3700 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
3702 struct clk_notifier *cn;
3710 list_for_each_entry(cn, &clk_notifier_list, node) {
3711 if (cn->clk == clk) {
3712 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
3714 clk->core->notifier_count--;
3716 /* XXX the notifier code should handle this better */
3717 if (!cn->notifier_head.head) {
3718 srcu_cleanup_notifier_head(&cn->notifier_head);
3719 list_del(&cn->node);
3726 clk_prepare_unlock();
3730 EXPORT_SYMBOL_GPL(clk_notifier_unregister);
3734 * struct of_clk_provider - Clock provider registration structure
3735 * @link: Entry in global list of clock providers
3736 * @node: Pointer to device tree node of clock provider
3737 * @get: Get clock callback. Returns NULL or a struct clk for the
3738 * given clock specifier
3739 * @data: context pointer to be passed into @get callback
3741 struct of_clk_provider {
3742 struct list_head link;
3744 struct device_node *node;
3745 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
3746 struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
3750 static const struct of_device_id __clk_of_table_sentinel
3751 __used __section(__clk_of_table_end);
3753 static LIST_HEAD(of_clk_providers);
3754 static DEFINE_MUTEX(of_clk_mutex);
3756 struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
3761 EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
3763 struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
3767 EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
3769 struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
3771 struct clk_onecell_data *clk_data = data;
3772 unsigned int idx = clkspec->args[0];
3774 if (idx >= clk_data->clk_num) {
3775 pr_err("%s: invalid clock index %u\n", __func__, idx);
3776 return ERR_PTR(-EINVAL);
3779 return clk_data->clks[idx];
3781 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
3784 of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
3786 struct clk_hw_onecell_data *hw_data = data;
3787 unsigned int idx = clkspec->args[0];
3789 if (idx >= hw_data->num) {
3790 pr_err("%s: invalid index %u\n", __func__, idx);
3791 return ERR_PTR(-EINVAL);
3794 return hw_data->hws[idx];
3796 EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
3799 * of_clk_add_provider() - Register a clock provider for a node
3800 * @np: Device node pointer associated with clock provider
3801 * @clk_src_get: callback for decoding clock
3802 * @data: context pointer for @clk_src_get callback.
3804 int of_clk_add_provider(struct device_node *np,
3805 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
3809 struct of_clk_provider *cp;
3812 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
3816 cp->node = of_node_get(np);
3818 cp->get = clk_src_get;
3820 mutex_lock(&of_clk_mutex);
3821 list_add(&cp->link, &of_clk_providers);
3822 mutex_unlock(&of_clk_mutex);
3823 pr_debug("Added clock from %pOF\n", np);
3825 ret = of_clk_set_defaults(np, true);
3827 of_clk_del_provider(np);
3831 EXPORT_SYMBOL_GPL(of_clk_add_provider);
3834 * of_clk_add_hw_provider() - Register a clock provider for a node
3835 * @np: Device node pointer associated with clock provider
3836 * @get: callback for decoding clk_hw
3837 * @data: context pointer for @get callback.
3839 int of_clk_add_hw_provider(struct device_node *np,
3840 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
3844 struct of_clk_provider *cp;
3847 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
3851 cp->node = of_node_get(np);
3855 mutex_lock(&of_clk_mutex);
3856 list_add(&cp->link, &of_clk_providers);
3857 mutex_unlock(&of_clk_mutex);
3858 pr_debug("Added clk_hw provider from %pOF\n", np);
3860 ret = of_clk_set_defaults(np, true);
3862 of_clk_del_provider(np);
3866 EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
3868 static void devm_of_clk_release_provider(struct device *dev, void *res)
3870 of_clk_del_provider(*(struct device_node **)res);
3873 int devm_of_clk_add_hw_provider(struct device *dev,
3874 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
3878 struct device_node **ptr, *np;
3881 ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
3887 ret = of_clk_add_hw_provider(np, get, data);
3890 devres_add(dev, ptr);
3897 EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);
3900 * of_clk_del_provider() - Remove a previously registered clock provider
3901 * @np: Device node pointer associated with clock provider
3903 void of_clk_del_provider(struct device_node *np)
3905 struct of_clk_provider *cp;
3907 mutex_lock(&of_clk_mutex);
3908 list_for_each_entry(cp, &of_clk_providers, link) {
3909 if (cp->node == np) {
3910 list_del(&cp->link);
3911 of_node_put(cp->node);
3916 mutex_unlock(&of_clk_mutex);
3918 EXPORT_SYMBOL_GPL(of_clk_del_provider);
3920 static int devm_clk_provider_match(struct device *dev, void *res, void *data)
3922 struct device_node **np = res;
3924 if (WARN_ON(!np || !*np))
3930 void devm_of_clk_del_provider(struct device *dev)
3934 ret = devres_release(dev, devm_of_clk_release_provider,
3935 devm_clk_provider_match, dev->of_node);
3939 EXPORT_SYMBOL(devm_of_clk_del_provider);
3941 static struct clk_hw *
3942 __of_clk_get_hw_from_provider(struct of_clk_provider *provider,
3943 struct of_phandle_args *clkspec)
3947 if (provider->get_hw)
3948 return provider->get_hw(clkspec, provider->data);
3950 clk = provider->get(clkspec, provider->data);
3952 return ERR_CAST(clk);
3953 return __clk_get_hw(clk);
3956 struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec,
3957 const char *dev_id, const char *con_id)
3959 struct of_clk_provider *provider;
3960 struct clk *clk = ERR_PTR(-EPROBE_DEFER);
3964 return ERR_PTR(-EINVAL);
3966 /* Check if we have such a provider in our array */
3967 mutex_lock(&of_clk_mutex);
3968 list_for_each_entry(provider, &of_clk_providers, link) {
3969 if (provider->node == clkspec->np) {
3970 hw = __of_clk_get_hw_from_provider(provider, clkspec);
3971 clk = __clk_create_clk(hw, dev_id, con_id);
3975 if (!__clk_get(clk)) {
3976 __clk_free_clk(clk);
3977 clk = ERR_PTR(-ENOENT);
3983 mutex_unlock(&of_clk_mutex);
3989 * of_clk_get_from_provider() - Lookup a clock from a clock provider
3990 * @clkspec: pointer to a clock specifier data structure
3992 * This function looks up a struct clk from the registered list of clock
3993 * providers, an input is a clock specifier data structure as returned
3994 * from the of_parse_phandle_with_args() function call.
3996 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
3998 return __of_clk_get_from_provider(clkspec, NULL, __func__);
4000 EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
4003 * of_clk_get_parent_count() - Count the number of clocks a device node has
4004 * @np: device node to count
4006 * Returns: The number of clocks that are possible parents of this node
4008 unsigned int of_clk_get_parent_count(struct device_node *np)
4012 count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
4018 EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
4020 const char *of_clk_get_parent_name(struct device_node *np, int index)
4022 struct of_phandle_args clkspec;
4023 struct property *prop;
4024 const char *clk_name;
4031 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
4036 index = clkspec.args_count ? clkspec.args[0] : 0;
4039 /* if there is an indices property, use it to transfer the index
4040 * specified into an array offset for the clock-output-names property.
4042 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
4049 /* We went off the end of 'clock-indices' without finding it */
4053 if (of_property_read_string_index(clkspec.np, "clock-output-names",
4057 * Best effort to get the name if the clock has been
4058 * registered with the framework. If the clock isn't
4059 * registered, we return the node name as the name of
4060 * the clock as long as #clock-cells = 0.
4062 clk = of_clk_get_from_provider(&clkspec);
4064 if (clkspec.args_count == 0)
4065 clk_name = clkspec.np->name;
4069 clk_name = __clk_get_name(clk);
4075 of_node_put(clkspec.np);
4078 EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
4081 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
4083 * @np: Device node pointer associated with clock provider
4084 * @parents: pointer to char array that hold the parents' names
4085 * @size: size of the @parents array
4087 * Return: number of parents for the clock node.
4089 int of_clk_parent_fill(struct device_node *np, const char **parents,
4094 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
4099 EXPORT_SYMBOL_GPL(of_clk_parent_fill);
4101 struct clock_provider {
4102 void (*clk_init_cb)(struct device_node *);
4103 struct device_node *np;
4104 struct list_head node;
4108 * This function looks for a parent clock. If there is one, then it
4109 * checks that the provider for this parent clock was initialized, in
4110 * this case the parent clock will be ready.
4112 static int parent_ready(struct device_node *np)
4117 struct clk *clk = of_clk_get(np, i);
4119 /* this parent is ready we can check the next one */
4126 /* at least one parent is not ready, we exit now */
4127 if (PTR_ERR(clk) == -EPROBE_DEFER)
4131 * Here we make assumption that the device tree is
4132 * written correctly. So an error means that there is
4133 * no more parent. As we didn't exit yet, then the
4134 * previous parent are ready. If there is no clock
4135 * parent, no need to wait for them, then we can
4136 * consider their absence as being ready
4143 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
4144 * @np: Device node pointer associated with clock provider
4145 * @index: clock index
4146 * @flags: pointer to top-level framework flags
4148 * Detects if the clock-critical property exists and, if so, sets the
4149 * corresponding CLK_IS_CRITICAL flag.
4151 * Do not use this function. It exists only for legacy Device Tree
4152 * bindings, such as the one-clock-per-node style that are outdated.
4153 * Those bindings typically put all clock data into .dts and the Linux
4154 * driver has no clock data, thus making it impossible to set this flag
4155 * correctly from the driver. Only those drivers may call
4156 * of_clk_detect_critical from their setup functions.
4158 * Return: error code or zero on success
4160 int of_clk_detect_critical(struct device_node *np,
4161 int index, unsigned long *flags)
4163 struct property *prop;
4170 of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
4172 *flags |= CLK_IS_CRITICAL;
4178 * of_clk_init() - Scan and init clock providers from the DT
4179 * @matches: array of compatible values and init functions for providers.
4181 * This function scans the device tree for matching clock providers
4182 * and calls their initialization functions. It also does it by trying
4183 * to follow the dependencies.
4185 void __init of_clk_init(const struct of_device_id *matches)
4187 const struct of_device_id *match;
4188 struct device_node *np;
4189 struct clock_provider *clk_provider, *next;
4192 LIST_HEAD(clk_provider_list);
4195 matches = &__clk_of_table;
4197 /* First prepare the list of the clocks providers */
4198 for_each_matching_node_and_match(np, matches, &match) {
4199 struct clock_provider *parent;
4201 if (!of_device_is_available(np))
4204 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
4206 list_for_each_entry_safe(clk_provider, next,
4207 &clk_provider_list, node) {
4208 list_del(&clk_provider->node);
4209 of_node_put(clk_provider->np);
4210 kfree(clk_provider);
4216 parent->clk_init_cb = match->data;
4217 parent->np = of_node_get(np);
4218 list_add_tail(&parent->node, &clk_provider_list);
4221 while (!list_empty(&clk_provider_list)) {
4222 is_init_done = false;
4223 list_for_each_entry_safe(clk_provider, next,
4224 &clk_provider_list, node) {
4225 if (force || parent_ready(clk_provider->np)) {
4227 /* Don't populate platform devices */
4228 of_node_set_flag(clk_provider->np,
4231 clk_provider->clk_init_cb(clk_provider->np);
4232 of_clk_set_defaults(clk_provider->np, true);
4234 list_del(&clk_provider->node);
4235 of_node_put(clk_provider->np);
4236 kfree(clk_provider);
4237 is_init_done = true;
4242 * We didn't manage to initialize any of the
4243 * remaining providers during the last loop, so now we
4244 * initialize all the remaining ones unconditionally
4245 * in case the clock parent was not mandatory