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)) {
247 ret = core->ops->is_enabled(core->hw);
250 pm_runtime_put(core->dev);
255 /*** helper functions ***/
257 const char *__clk_get_name(const struct clk *clk)
259 return !clk ? NULL : clk->core->name;
261 EXPORT_SYMBOL_GPL(__clk_get_name);
263 const char *clk_hw_get_name(const struct clk_hw *hw)
265 return hw->core->name;
267 EXPORT_SYMBOL_GPL(clk_hw_get_name);
269 struct clk_hw *__clk_get_hw(struct clk *clk)
271 return !clk ? NULL : clk->core->hw;
273 EXPORT_SYMBOL_GPL(__clk_get_hw);
275 unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
277 return hw->core->num_parents;
279 EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
281 struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
283 return hw->core->parent ? hw->core->parent->hw : NULL;
285 EXPORT_SYMBOL_GPL(clk_hw_get_parent);
287 static struct clk_core *__clk_lookup_subtree(const char *name,
288 struct clk_core *core)
290 struct clk_core *child;
291 struct clk_core *ret;
293 if (!strcmp(core->name, name))
296 hlist_for_each_entry(child, &core->children, child_node) {
297 ret = __clk_lookup_subtree(name, child);
305 static struct clk_core *clk_core_lookup(const char *name)
307 struct clk_core *root_clk;
308 struct clk_core *ret;
313 /* search the 'proper' clk tree first */
314 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
315 ret = __clk_lookup_subtree(name, root_clk);
320 /* if not found, then search the orphan tree */
321 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
322 ret = __clk_lookup_subtree(name, root_clk);
330 static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
333 if (!core || index >= core->num_parents)
336 if (!core->parents[index])
337 core->parents[index] =
338 clk_core_lookup(core->parent_names[index]);
340 return core->parents[index];
344 clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
346 struct clk_core *parent;
348 parent = clk_core_get_parent_by_index(hw->core, index);
350 return !parent ? NULL : parent->hw;
352 EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
354 unsigned int __clk_get_enable_count(struct clk *clk)
356 return !clk ? 0 : clk->core->enable_count;
359 static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
370 if (!core->num_parents)
380 unsigned long clk_hw_get_rate(const struct clk_hw *hw)
382 return clk_core_get_rate_nolock(hw->core);
384 EXPORT_SYMBOL_GPL(clk_hw_get_rate);
386 static unsigned long __clk_get_accuracy(struct clk_core *core)
391 return core->accuracy;
394 unsigned long __clk_get_flags(struct clk *clk)
396 return !clk ? 0 : clk->core->flags;
398 EXPORT_SYMBOL_GPL(__clk_get_flags);
400 unsigned long clk_hw_get_flags(const struct clk_hw *hw)
402 return hw->core->flags;
404 EXPORT_SYMBOL_GPL(clk_hw_get_flags);
406 bool clk_hw_is_prepared(const struct clk_hw *hw)
408 return clk_core_is_prepared(hw->core);
411 bool clk_hw_rate_is_protected(const struct clk_hw *hw)
413 return clk_core_rate_is_protected(hw->core);
416 bool clk_hw_is_enabled(const struct clk_hw *hw)
418 return clk_core_is_enabled(hw->core);
421 bool __clk_is_enabled(struct clk *clk)
426 return clk_core_is_enabled(clk->core);
428 EXPORT_SYMBOL_GPL(__clk_is_enabled);
430 static bool mux_is_better_rate(unsigned long rate, unsigned long now,
431 unsigned long best, unsigned long flags)
433 if (flags & CLK_MUX_ROUND_CLOSEST)
434 return abs(now - rate) < abs(best - rate);
436 return now <= rate && now > best;
439 int clk_mux_determine_rate_flags(struct clk_hw *hw,
440 struct clk_rate_request *req,
443 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
444 int i, num_parents, ret;
445 unsigned long best = 0;
446 struct clk_rate_request parent_req = *req;
448 /* if NO_REPARENT flag set, pass through to current parent */
449 if (core->flags & CLK_SET_RATE_NO_REPARENT) {
450 parent = core->parent;
451 if (core->flags & CLK_SET_RATE_PARENT) {
452 ret = __clk_determine_rate(parent ? parent->hw : NULL,
457 best = parent_req.rate;
459 best = clk_core_get_rate_nolock(parent);
461 best = clk_core_get_rate_nolock(core);
467 /* find the parent that can provide the fastest rate <= rate */
468 num_parents = core->num_parents;
469 for (i = 0; i < num_parents; i++) {
470 parent = clk_core_get_parent_by_index(core, i);
474 if (core->flags & CLK_SET_RATE_PARENT) {
476 ret = __clk_determine_rate(parent->hw, &parent_req);
480 parent_req.rate = clk_core_get_rate_nolock(parent);
483 if (mux_is_better_rate(req->rate, parent_req.rate,
485 best_parent = parent;
486 best = parent_req.rate;
495 req->best_parent_hw = best_parent->hw;
496 req->best_parent_rate = best;
501 EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);
503 struct clk *__clk_lookup(const char *name)
505 struct clk_core *core = clk_core_lookup(name);
507 return !core ? NULL : core->hw->clk;
510 static void clk_core_get_boundaries(struct clk_core *core,
511 unsigned long *min_rate,
512 unsigned long *max_rate)
514 struct clk *clk_user;
516 *min_rate = core->min_rate;
517 *max_rate = core->max_rate;
519 hlist_for_each_entry(clk_user, &core->clks, clks_node)
520 *min_rate = max(*min_rate, clk_user->min_rate);
522 hlist_for_each_entry(clk_user, &core->clks, clks_node)
523 *max_rate = min(*max_rate, clk_user->max_rate);
526 static bool clk_core_check_boundaries(struct clk_core *core,
527 unsigned long min_rate,
528 unsigned long max_rate)
532 lockdep_assert_held(&prepare_lock);
534 if (min_rate > core->max_rate || max_rate < core->min_rate)
537 hlist_for_each_entry(user, &core->clks, clks_node)
538 if (min_rate > user->max_rate || max_rate < user->min_rate)
544 void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
545 unsigned long max_rate)
547 hw->core->min_rate = min_rate;
548 hw->core->max_rate = max_rate;
550 EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
553 * Helper for finding best parent to provide a given frequency. This can be used
554 * directly as a determine_rate callback (e.g. for a mux), or from a more
555 * complex clock that may combine a mux with other operations.
557 int __clk_mux_determine_rate(struct clk_hw *hw,
558 struct clk_rate_request *req)
560 return clk_mux_determine_rate_flags(hw, req, 0);
562 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
564 int __clk_mux_determine_rate_closest(struct clk_hw *hw,
565 struct clk_rate_request *req)
567 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
569 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
573 static void clk_core_rate_unprotect(struct clk_core *core)
575 lockdep_assert_held(&prepare_lock);
580 if (WARN(core->protect_count == 0,
581 "%s already unprotected\n", core->name))
584 if (--core->protect_count > 0)
587 clk_core_rate_unprotect(core->parent);
590 static int clk_core_rate_nuke_protect(struct clk_core *core)
594 lockdep_assert_held(&prepare_lock);
599 if (core->protect_count == 0)
602 ret = core->protect_count;
603 core->protect_count = 1;
604 clk_core_rate_unprotect(core);
610 * clk_rate_exclusive_put - release exclusivity over clock rate control
611 * @clk: the clk over which the exclusivity is released
613 * clk_rate_exclusive_put() completes a critical section during which a clock
614 * consumer cannot tolerate any other consumer making any operation on the
615 * clock which could result in a rate change or rate glitch. Exclusive clocks
616 * cannot have their rate changed, either directly or indirectly due to changes
617 * further up the parent chain of clocks. As a result, clocks up parent chain
618 * also get under exclusive control of the calling consumer.
620 * If exlusivity is claimed more than once on clock, even by the same consumer,
621 * the rate effectively gets locked as exclusivity can't be preempted.
623 * Calls to clk_rate_exclusive_put() must be balanced with calls to
624 * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
627 void clk_rate_exclusive_put(struct clk *clk)
635 * if there is something wrong with this consumer protect count, stop
636 * here before messing with the provider
638 if (WARN_ON(clk->exclusive_count <= 0))
641 clk_core_rate_unprotect(clk->core);
642 clk->exclusive_count--;
644 clk_prepare_unlock();
646 EXPORT_SYMBOL_GPL(clk_rate_exclusive_put);
648 static void clk_core_rate_protect(struct clk_core *core)
650 lockdep_assert_held(&prepare_lock);
655 if (core->protect_count == 0)
656 clk_core_rate_protect(core->parent);
658 core->protect_count++;
661 static void clk_core_rate_restore_protect(struct clk_core *core, int count)
663 lockdep_assert_held(&prepare_lock);
671 clk_core_rate_protect(core);
672 core->protect_count = count;
676 * clk_rate_exclusive_get - get exclusivity over the clk rate control
677 * @clk: the clk over which the exclusity of rate control is requested
679 * clk_rate_exlusive_get() begins a critical section during which a clock
680 * consumer cannot tolerate any other consumer making any operation on the
681 * clock which could result in a rate change or rate glitch. Exclusive clocks
682 * cannot have their rate changed, either directly or indirectly due to changes
683 * further up the parent chain of clocks. As a result, clocks up parent chain
684 * also get under exclusive control of the calling consumer.
686 * If exlusivity is claimed more than once on clock, even by the same consumer,
687 * the rate effectively gets locked as exclusivity can't be preempted.
689 * Calls to clk_rate_exclusive_get() should be balanced with calls to
690 * clk_rate_exclusive_put(). Calls to this function may sleep.
691 * Returns 0 on success, -EERROR otherwise
693 int clk_rate_exclusive_get(struct clk *clk)
699 clk_core_rate_protect(clk->core);
700 clk->exclusive_count++;
701 clk_prepare_unlock();
705 EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
707 static void clk_core_unprepare(struct clk_core *core)
709 lockdep_assert_held(&prepare_lock);
714 if (WARN(core->prepare_count == 0,
715 "%s already unprepared\n", core->name))
718 if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL,
719 "Unpreparing critical %s\n", core->name))
722 if (core->flags & CLK_SET_RATE_GATE)
723 clk_core_rate_unprotect(core);
725 if (--core->prepare_count > 0)
728 WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);
730 trace_clk_unprepare(core);
732 if (core->ops->unprepare)
733 core->ops->unprepare(core->hw);
735 trace_clk_unprepare_complete(core);
736 clk_core_unprepare(core->parent);
737 clk_pm_runtime_put(core);
740 static void clk_core_unprepare_lock(struct clk_core *core)
743 clk_core_unprepare(core);
744 clk_prepare_unlock();
748 * clk_unprepare - undo preparation of a clock source
749 * @clk: the clk being unprepared
751 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
752 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
753 * if the operation may sleep. One example is a clk which is accessed over
754 * I2c. In the complex case a clk gate operation may require a fast and a slow
755 * part. It is this reason that clk_unprepare and clk_disable are not mutually
756 * exclusive. In fact clk_disable must be called before clk_unprepare.
758 void clk_unprepare(struct clk *clk)
760 if (IS_ERR_OR_NULL(clk))
763 clk_core_unprepare_lock(clk->core);
765 EXPORT_SYMBOL_GPL(clk_unprepare);
767 static int clk_core_prepare(struct clk_core *core)
771 lockdep_assert_held(&prepare_lock);
776 if (core->prepare_count == 0) {
777 ret = clk_pm_runtime_get(core);
781 ret = clk_core_prepare(core->parent);
785 trace_clk_prepare(core);
787 if (core->ops->prepare)
788 ret = core->ops->prepare(core->hw);
790 trace_clk_prepare_complete(core);
796 core->prepare_count++;
799 * CLK_SET_RATE_GATE is a special case of clock protection
800 * Instead of a consumer claiming exclusive rate control, it is
801 * actually the provider which prevents any consumer from making any
802 * operation which could result in a rate change or rate glitch while
803 * the clock is prepared.
805 if (core->flags & CLK_SET_RATE_GATE)
806 clk_core_rate_protect(core);
810 clk_core_unprepare(core->parent);
812 clk_pm_runtime_put(core);
816 static int clk_core_prepare_lock(struct clk_core *core)
821 ret = clk_core_prepare(core);
822 clk_prepare_unlock();
828 * clk_prepare - prepare a clock source
829 * @clk: the clk being prepared
831 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
832 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
833 * operation may sleep. One example is a clk which is accessed over I2c. In
834 * the complex case a clk ungate operation may require a fast and a slow part.
835 * It is this reason that clk_prepare and clk_enable are not mutually
836 * exclusive. In fact clk_prepare must be called before clk_enable.
837 * Returns 0 on success, -EERROR otherwise.
839 int clk_prepare(struct clk *clk)
844 return clk_core_prepare_lock(clk->core);
846 EXPORT_SYMBOL_GPL(clk_prepare);
848 static void clk_core_disable(struct clk_core *core)
850 lockdep_assert_held(&enable_lock);
855 if (WARN(core->enable_count == 0, "%s already disabled\n", core->name))
858 if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL,
859 "Disabling critical %s\n", core->name))
862 if (--core->enable_count > 0)
865 trace_clk_disable_rcuidle(core);
867 if (core->ops->disable)
868 core->ops->disable(core->hw);
870 trace_clk_disable_complete_rcuidle(core);
872 clk_core_disable(core->parent);
875 static void clk_core_disable_lock(struct clk_core *core)
879 flags = clk_enable_lock();
880 clk_core_disable(core);
881 clk_enable_unlock(flags);
885 * clk_disable - gate a clock
886 * @clk: the clk being gated
888 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
889 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
890 * clk if the operation is fast and will never sleep. One example is a
891 * SoC-internal clk which is controlled via simple register writes. In the
892 * complex case a clk gate operation may require a fast and a slow part. It is
893 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
894 * In fact clk_disable must be called before clk_unprepare.
896 void clk_disable(struct clk *clk)
898 if (IS_ERR_OR_NULL(clk))
901 clk_core_disable_lock(clk->core);
903 EXPORT_SYMBOL_GPL(clk_disable);
905 static int clk_core_enable(struct clk_core *core)
909 lockdep_assert_held(&enable_lock);
914 if (WARN(core->prepare_count == 0,
915 "Enabling unprepared %s\n", core->name))
918 if (core->enable_count == 0) {
919 ret = clk_core_enable(core->parent);
924 trace_clk_enable_rcuidle(core);
926 if (core->ops->enable)
927 ret = core->ops->enable(core->hw);
929 trace_clk_enable_complete_rcuidle(core);
932 clk_core_disable(core->parent);
937 core->enable_count++;
941 static int clk_core_enable_lock(struct clk_core *core)
946 flags = clk_enable_lock();
947 ret = clk_core_enable(core);
948 clk_enable_unlock(flags);
954 * clk_enable - ungate a clock
955 * @clk: the clk being ungated
957 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
958 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
959 * if the operation will never sleep. One example is a SoC-internal clk which
960 * is controlled via simple register writes. In the complex case a clk ungate
961 * operation may require a fast and a slow part. It is this reason that
962 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
963 * must be called before clk_enable. Returns 0 on success, -EERROR
966 int clk_enable(struct clk *clk)
971 return clk_core_enable_lock(clk->core);
973 EXPORT_SYMBOL_GPL(clk_enable);
975 static int clk_core_prepare_enable(struct clk_core *core)
979 ret = clk_core_prepare_lock(core);
983 ret = clk_core_enable_lock(core);
985 clk_core_unprepare_lock(core);
990 static void clk_core_disable_unprepare(struct clk_core *core)
992 clk_core_disable_lock(core);
993 clk_core_unprepare_lock(core);
996 static void clk_unprepare_unused_subtree(struct clk_core *core)
998 struct clk_core *child;
1000 lockdep_assert_held(&prepare_lock);
1002 hlist_for_each_entry(child, &core->children, child_node)
1003 clk_unprepare_unused_subtree(child);
1005 if (core->prepare_count)
1008 if (core->flags & CLK_IGNORE_UNUSED)
1011 if (clk_pm_runtime_get(core))
1014 if (clk_core_is_prepared(core)) {
1015 trace_clk_unprepare(core);
1016 if (core->ops->unprepare_unused)
1017 core->ops->unprepare_unused(core->hw);
1018 else if (core->ops->unprepare)
1019 core->ops->unprepare(core->hw);
1020 trace_clk_unprepare_complete(core);
1023 clk_pm_runtime_put(core);
1026 static void clk_disable_unused_subtree(struct clk_core *core)
1028 struct clk_core *child;
1029 unsigned long flags;
1031 lockdep_assert_held(&prepare_lock);
1033 hlist_for_each_entry(child, &core->children, child_node)
1034 clk_disable_unused_subtree(child);
1036 if (core->flags & CLK_OPS_PARENT_ENABLE)
1037 clk_core_prepare_enable(core->parent);
1039 if (clk_pm_runtime_get(core))
1042 flags = clk_enable_lock();
1044 if (core->enable_count)
1047 if (core->flags & CLK_IGNORE_UNUSED)
1051 * some gate clocks have special needs during the disable-unused
1052 * sequence. call .disable_unused if available, otherwise fall
1055 if (clk_core_is_enabled(core)) {
1056 trace_clk_disable(core);
1057 if (core->ops->disable_unused)
1058 core->ops->disable_unused(core->hw);
1059 else if (core->ops->disable)
1060 core->ops->disable(core->hw);
1061 trace_clk_disable_complete(core);
1065 clk_enable_unlock(flags);
1066 clk_pm_runtime_put(core);
1068 if (core->flags & CLK_OPS_PARENT_ENABLE)
1069 clk_core_disable_unprepare(core->parent);
1072 static bool clk_ignore_unused;
1073 static int __init clk_ignore_unused_setup(char *__unused)
1075 clk_ignore_unused = true;
1078 __setup("clk_ignore_unused", clk_ignore_unused_setup);
1080 static int clk_disable_unused(void)
1082 struct clk_core *core;
1084 if (clk_ignore_unused) {
1085 pr_warn("clk: Not disabling unused clocks\n");
1091 hlist_for_each_entry(core, &clk_root_list, child_node)
1092 clk_disable_unused_subtree(core);
1094 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1095 clk_disable_unused_subtree(core);
1097 hlist_for_each_entry(core, &clk_root_list, child_node)
1098 clk_unprepare_unused_subtree(core);
1100 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1101 clk_unprepare_unused_subtree(core);
1103 clk_prepare_unlock();
1107 late_initcall_sync(clk_disable_unused);
1109 static int clk_core_determine_round_nolock(struct clk_core *core,
1110 struct clk_rate_request *req)
1114 lockdep_assert_held(&prepare_lock);
1120 * At this point, core protection will be disabled if
1121 * - if the provider is not protected at all
1122 * - if the calling consumer is the only one which has exclusivity
1125 if (clk_core_rate_is_protected(core)) {
1126 req->rate = core->rate;
1127 } else if (core->ops->determine_rate) {
1128 return core->ops->determine_rate(core->hw, req);
1129 } else if (core->ops->round_rate) {
1130 rate = core->ops->round_rate(core->hw, req->rate,
1131 &req->best_parent_rate);
1143 static void clk_core_init_rate_req(struct clk_core * const core,
1144 struct clk_rate_request *req)
1146 struct clk_core *parent;
1148 if (WARN_ON(!core || !req))
1151 parent = core->parent;
1153 req->best_parent_hw = parent->hw;
1154 req->best_parent_rate = parent->rate;
1156 req->best_parent_hw = NULL;
1157 req->best_parent_rate = 0;
1161 static bool clk_core_can_round(struct clk_core * const core)
1163 if (core->ops->determine_rate || core->ops->round_rate)
1169 static int clk_core_round_rate_nolock(struct clk_core *core,
1170 struct clk_rate_request *req)
1172 lockdep_assert_held(&prepare_lock);
1179 clk_core_init_rate_req(core, req);
1181 if (clk_core_can_round(core))
1182 return clk_core_determine_round_nolock(core, req);
1183 else if (core->flags & CLK_SET_RATE_PARENT)
1184 return clk_core_round_rate_nolock(core->parent, req);
1186 req->rate = core->rate;
1191 * __clk_determine_rate - get the closest rate actually supported by a clock
1192 * @hw: determine the rate of this clock
1193 * @req: target rate request
1195 * Useful for clk_ops such as .set_rate and .determine_rate.
1197 int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
1204 return clk_core_round_rate_nolock(hw->core, req);
1206 EXPORT_SYMBOL_GPL(__clk_determine_rate);
1208 unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
1211 struct clk_rate_request req;
1213 clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate);
1216 ret = clk_core_round_rate_nolock(hw->core, &req);
1222 EXPORT_SYMBOL_GPL(clk_hw_round_rate);
1225 * clk_round_rate - round the given rate for a clk
1226 * @clk: the clk for which we are rounding a rate
1227 * @rate: the rate which is to be rounded
1229 * Takes in a rate as input and rounds it to a rate that the clk can actually
1230 * use which is then returned. If clk doesn't support round_rate operation
1231 * then the parent rate is returned.
1233 long clk_round_rate(struct clk *clk, unsigned long rate)
1235 struct clk_rate_request req;
1243 if (clk->exclusive_count)
1244 clk_core_rate_unprotect(clk->core);
1246 clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
1249 ret = clk_core_round_rate_nolock(clk->core, &req);
1251 if (clk->exclusive_count)
1252 clk_core_rate_protect(clk->core);
1254 clk_prepare_unlock();
1261 EXPORT_SYMBOL_GPL(clk_round_rate);
1264 * __clk_notify - call clk notifier chain
1265 * @core: clk that is changing rate
1266 * @msg: clk notifier type (see include/linux/clk.h)
1267 * @old_rate: old clk rate
1268 * @new_rate: new clk rate
1270 * Triggers a notifier call chain on the clk rate-change notification
1271 * for 'clk'. Passes a pointer to the struct clk and the previous
1272 * and current rates to the notifier callback. Intended to be called by
1273 * internal clock code only. Returns NOTIFY_DONE from the last driver
1274 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1275 * a driver returns that.
1277 static int __clk_notify(struct clk_core *core, unsigned long msg,
1278 unsigned long old_rate, unsigned long new_rate)
1280 struct clk_notifier *cn;
1281 struct clk_notifier_data cnd;
1282 int ret = NOTIFY_DONE;
1284 cnd.old_rate = old_rate;
1285 cnd.new_rate = new_rate;
1287 list_for_each_entry(cn, &clk_notifier_list, node) {
1288 if (cn->clk->core == core) {
1290 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
1292 if (ret & NOTIFY_STOP_MASK)
1301 * __clk_recalc_accuracies
1302 * @core: first clk in the subtree
1304 * Walks the subtree of clks starting with clk and recalculates accuracies as
1305 * it goes. Note that if a clk does not implement the .recalc_accuracy
1306 * callback then it is assumed that the clock will take on the accuracy of its
1309 static void __clk_recalc_accuracies(struct clk_core *core)
1311 unsigned long parent_accuracy = 0;
1312 struct clk_core *child;
1314 lockdep_assert_held(&prepare_lock);
1317 parent_accuracy = core->parent->accuracy;
1319 if (core->ops->recalc_accuracy)
1320 core->accuracy = core->ops->recalc_accuracy(core->hw,
1323 core->accuracy = parent_accuracy;
1325 hlist_for_each_entry(child, &core->children, child_node)
1326 __clk_recalc_accuracies(child);
1329 static long clk_core_get_accuracy(struct clk_core *core)
1331 unsigned long accuracy;
1334 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
1335 __clk_recalc_accuracies(core);
1337 accuracy = __clk_get_accuracy(core);
1338 clk_prepare_unlock();
1344 * clk_get_accuracy - return the accuracy of clk
1345 * @clk: the clk whose accuracy is being returned
1347 * Simply returns the cached accuracy of the clk, unless
1348 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1350 * If clk is NULL then returns 0.
1352 long clk_get_accuracy(struct clk *clk)
1357 return clk_core_get_accuracy(clk->core);
1359 EXPORT_SYMBOL_GPL(clk_get_accuracy);
1361 static unsigned long clk_recalc(struct clk_core *core,
1362 unsigned long parent_rate)
1364 unsigned long rate = parent_rate;
1366 if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
1367 rate = core->ops->recalc_rate(core->hw, parent_rate);
1368 clk_pm_runtime_put(core);
1374 * __clk_recalc_rates
1375 * @core: first clk in the subtree
1376 * @msg: notification type (see include/linux/clk.h)
1378 * Walks the subtree of clks starting with clk and recalculates rates as it
1379 * goes. Note that if a clk does not implement the .recalc_rate callback then
1380 * it is assumed that the clock will take on the rate of its parent.
1382 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1385 static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
1387 unsigned long old_rate;
1388 unsigned long parent_rate = 0;
1389 struct clk_core *child;
1391 lockdep_assert_held(&prepare_lock);
1393 old_rate = core->rate;
1396 parent_rate = core->parent->rate;
1398 core->rate = clk_recalc(core, parent_rate);
1401 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1402 * & ABORT_RATE_CHANGE notifiers
1404 if (core->notifier_count && msg)
1405 __clk_notify(core, msg, old_rate, core->rate);
1407 hlist_for_each_entry(child, &core->children, child_node)
1408 __clk_recalc_rates(child, msg);
1411 static unsigned long clk_core_get_rate(struct clk_core *core)
1417 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1418 __clk_recalc_rates(core, 0);
1420 rate = clk_core_get_rate_nolock(core);
1421 clk_prepare_unlock();
1427 * clk_get_rate - return the rate of clk
1428 * @clk: the clk whose rate is being returned
1430 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1431 * is set, which means a recalc_rate will be issued.
1432 * If clk is NULL then returns 0.
1434 unsigned long clk_get_rate(struct clk *clk)
1439 return clk_core_get_rate(clk->core);
1441 EXPORT_SYMBOL_GPL(clk_get_rate);
1443 static int clk_fetch_parent_index(struct clk_core *core,
1444 struct clk_core *parent)
1451 for (i = 0; i < core->num_parents; i++)
1452 if (clk_core_get_parent_by_index(core, i) == parent)
1459 * Update the orphan status of @core and all its children.
1461 static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
1463 struct clk_core *child;
1465 core->orphan = is_orphan;
1467 hlist_for_each_entry(child, &core->children, child_node)
1468 clk_core_update_orphan_status(child, is_orphan);
1471 static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1473 bool was_orphan = core->orphan;
1475 hlist_del(&core->child_node);
1478 bool becomes_orphan = new_parent->orphan;
1480 /* avoid duplicate POST_RATE_CHANGE notifications */
1481 if (new_parent->new_child == core)
1482 new_parent->new_child = NULL;
1484 hlist_add_head(&core->child_node, &new_parent->children);
1486 if (was_orphan != becomes_orphan)
1487 clk_core_update_orphan_status(core, becomes_orphan);
1489 hlist_add_head(&core->child_node, &clk_orphan_list);
1491 clk_core_update_orphan_status(core, true);
1494 core->parent = new_parent;
1497 static struct clk_core *__clk_set_parent_before(struct clk_core *core,
1498 struct clk_core *parent)
1500 unsigned long flags;
1501 struct clk_core *old_parent = core->parent;
1504 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
1506 * 2. Migrate prepare state between parents and prevent race with
1509 * If the clock is not prepared, then a race with
1510 * clk_enable/disable() is impossible since we already have the
1511 * prepare lock (future calls to clk_enable() need to be preceded by
1514 * If the clock is prepared, migrate the prepared state to the new
1515 * parent and also protect against a race with clk_enable() by
1516 * forcing the clock and the new parent on. This ensures that all
1517 * future calls to clk_enable() are practically NOPs with respect to
1518 * hardware and software states.
1520 * See also: Comment for clk_set_parent() below.
1523 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
1524 if (core->flags & CLK_OPS_PARENT_ENABLE) {
1525 clk_core_prepare_enable(old_parent);
1526 clk_core_prepare_enable(parent);
1529 /* migrate prepare count if > 0 */
1530 if (core->prepare_count) {
1531 clk_core_prepare_enable(parent);
1532 clk_core_enable_lock(core);
1535 /* update the clk tree topology */
1536 flags = clk_enable_lock();
1537 clk_reparent(core, parent);
1538 clk_enable_unlock(flags);
1543 static void __clk_set_parent_after(struct clk_core *core,
1544 struct clk_core *parent,
1545 struct clk_core *old_parent)
1548 * Finish the migration of prepare state and undo the changes done
1549 * for preventing a race with clk_enable().
1551 if (core->prepare_count) {
1552 clk_core_disable_lock(core);
1553 clk_core_disable_unprepare(old_parent);
1556 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
1557 if (core->flags & CLK_OPS_PARENT_ENABLE) {
1558 clk_core_disable_unprepare(parent);
1559 clk_core_disable_unprepare(old_parent);
1563 static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
1566 unsigned long flags;
1568 struct clk_core *old_parent;
1570 old_parent = __clk_set_parent_before(core, parent);
1572 trace_clk_set_parent(core, parent);
1574 /* change clock input source */
1575 if (parent && core->ops->set_parent)
1576 ret = core->ops->set_parent(core->hw, p_index);
1578 trace_clk_set_parent_complete(core, parent);
1581 flags = clk_enable_lock();
1582 clk_reparent(core, old_parent);
1583 clk_enable_unlock(flags);
1584 __clk_set_parent_after(core, old_parent, parent);
1589 __clk_set_parent_after(core, parent, old_parent);
1595 * __clk_speculate_rates
1596 * @core: first clk in the subtree
1597 * @parent_rate: the "future" rate of clk's parent
1599 * Walks the subtree of clks starting with clk, speculating rates as it
1600 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1602 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1603 * pre-rate change notifications and returns early if no clks in the
1604 * subtree have subscribed to the notifications. Note that if a clk does not
1605 * implement the .recalc_rate callback then it is assumed that the clock will
1606 * take on the rate of its parent.
1608 static int __clk_speculate_rates(struct clk_core *core,
1609 unsigned long parent_rate)
1611 struct clk_core *child;
1612 unsigned long new_rate;
1613 int ret = NOTIFY_DONE;
1615 lockdep_assert_held(&prepare_lock);
1617 new_rate = clk_recalc(core, parent_rate);
1619 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1620 if (core->notifier_count)
1621 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
1623 if (ret & NOTIFY_STOP_MASK) {
1624 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1625 __func__, core->name, ret);
1629 hlist_for_each_entry(child, &core->children, child_node) {
1630 ret = __clk_speculate_rates(child, new_rate);
1631 if (ret & NOTIFY_STOP_MASK)
1639 static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
1640 struct clk_core *new_parent, u8 p_index)
1642 struct clk_core *child;
1644 core->new_rate = new_rate;
1645 core->new_parent = new_parent;
1646 core->new_parent_index = p_index;
1647 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1648 core->new_child = NULL;
1649 if (new_parent && new_parent != core->parent)
1650 new_parent->new_child = core;
1652 hlist_for_each_entry(child, &core->children, child_node) {
1653 child->new_rate = clk_recalc(child, new_rate);
1654 clk_calc_subtree(child, child->new_rate, NULL, 0);
1659 * calculate the new rates returning the topmost clock that has to be
1662 static struct clk_core *clk_calc_new_rates(struct clk_core *core,
1665 struct clk_core *top = core;
1666 struct clk_core *old_parent, *parent;
1667 unsigned long best_parent_rate = 0;
1668 unsigned long new_rate;
1669 unsigned long min_rate;
1670 unsigned long max_rate;
1675 if (IS_ERR_OR_NULL(core))
1678 /* save parent rate, if it exists */
1679 parent = old_parent = core->parent;
1681 best_parent_rate = parent->rate;
1683 clk_core_get_boundaries(core, &min_rate, &max_rate);
1685 /* find the closest rate and parent clk/rate */
1686 if (clk_core_can_round(core)) {
1687 struct clk_rate_request req;
1690 req.min_rate = min_rate;
1691 req.max_rate = max_rate;
1693 clk_core_init_rate_req(core, &req);
1695 ret = clk_core_determine_round_nolock(core, &req);
1699 best_parent_rate = req.best_parent_rate;
1700 new_rate = req.rate;
1701 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
1703 if (new_rate < min_rate || new_rate > max_rate)
1705 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
1706 /* pass-through clock without adjustable parent */
1707 core->new_rate = core->rate;
1710 /* pass-through clock with adjustable parent */
1711 top = clk_calc_new_rates(parent, rate);
1712 new_rate = parent->new_rate;
1716 /* some clocks must be gated to change parent */
1717 if (parent != old_parent &&
1718 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1719 pr_debug("%s: %s not gated but wants to reparent\n",
1720 __func__, core->name);
1724 /* try finding the new parent index */
1725 if (parent && core->num_parents > 1) {
1726 p_index = clk_fetch_parent_index(core, parent);
1728 pr_debug("%s: clk %s can not be parent of clk %s\n",
1729 __func__, parent->name, core->name);
1734 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
1735 best_parent_rate != parent->rate)
1736 top = clk_calc_new_rates(parent, best_parent_rate);
1739 clk_calc_subtree(core, new_rate, parent, p_index);
1745 * Notify about rate changes in a subtree. Always walk down the whole tree
1746 * so that in case of an error we can walk down the whole tree again and
1749 static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
1750 unsigned long event)
1752 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
1753 int ret = NOTIFY_DONE;
1755 if (core->rate == core->new_rate)
1758 if (core->notifier_count) {
1759 ret = __clk_notify(core, event, core->rate, core->new_rate);
1760 if (ret & NOTIFY_STOP_MASK)
1764 hlist_for_each_entry(child, &core->children, child_node) {
1765 /* Skip children who will be reparented to another clock */
1766 if (child->new_parent && child->new_parent != core)
1768 tmp_clk = clk_propagate_rate_change(child, event);
1773 /* handle the new child who might not be in core->children yet */
1774 if (core->new_child) {
1775 tmp_clk = clk_propagate_rate_change(core->new_child, event);
1784 * walk down a subtree and set the new rates notifying the rate
1787 static void clk_change_rate(struct clk_core *core)
1789 struct clk_core *child;
1790 struct hlist_node *tmp;
1791 unsigned long old_rate;
1792 unsigned long best_parent_rate = 0;
1793 bool skip_set_rate = false;
1794 struct clk_core *old_parent;
1795 struct clk_core *parent = NULL;
1797 old_rate = core->rate;
1799 if (core->new_parent) {
1800 parent = core->new_parent;
1801 best_parent_rate = core->new_parent->rate;
1802 } else if (core->parent) {
1803 parent = core->parent;
1804 best_parent_rate = core->parent->rate;
1807 if (clk_pm_runtime_get(core))
1810 if (core->flags & CLK_SET_RATE_UNGATE) {
1811 unsigned long flags;
1813 clk_core_prepare(core);
1814 flags = clk_enable_lock();
1815 clk_core_enable(core);
1816 clk_enable_unlock(flags);
1819 if (core->new_parent && core->new_parent != core->parent) {
1820 old_parent = __clk_set_parent_before(core, core->new_parent);
1821 trace_clk_set_parent(core, core->new_parent);
1823 if (core->ops->set_rate_and_parent) {
1824 skip_set_rate = true;
1825 core->ops->set_rate_and_parent(core->hw, core->new_rate,
1827 core->new_parent_index);
1828 } else if (core->ops->set_parent) {
1829 core->ops->set_parent(core->hw, core->new_parent_index);
1832 trace_clk_set_parent_complete(core, core->new_parent);
1833 __clk_set_parent_after(core, core->new_parent, old_parent);
1836 if (core->flags & CLK_OPS_PARENT_ENABLE)
1837 clk_core_prepare_enable(parent);
1839 trace_clk_set_rate(core, core->new_rate);
1841 if (!skip_set_rate && core->ops->set_rate)
1842 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
1844 trace_clk_set_rate_complete(core, core->new_rate);
1846 core->rate = clk_recalc(core, best_parent_rate);
1848 if (core->flags & CLK_SET_RATE_UNGATE) {
1849 unsigned long flags;
1851 flags = clk_enable_lock();
1852 clk_core_disable(core);
1853 clk_enable_unlock(flags);
1854 clk_core_unprepare(core);
1857 if (core->flags & CLK_OPS_PARENT_ENABLE)
1858 clk_core_disable_unprepare(parent);
1860 if (core->notifier_count && old_rate != core->rate)
1861 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
1863 if (core->flags & CLK_RECALC_NEW_RATES)
1864 (void)clk_calc_new_rates(core, core->new_rate);
1867 * Use safe iteration, as change_rate can actually swap parents
1868 * for certain clock types.
1870 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
1871 /* Skip children who will be reparented to another clock */
1872 if (child->new_parent && child->new_parent != core)
1874 clk_change_rate(child);
1877 /* handle the new child who might not be in core->children yet */
1878 if (core->new_child)
1879 clk_change_rate(core->new_child);
1881 clk_pm_runtime_put(core);
1884 static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
1885 unsigned long req_rate)
1888 struct clk_rate_request req;
1890 lockdep_assert_held(&prepare_lock);
1895 /* simulate what the rate would be if it could be freely set */
1896 cnt = clk_core_rate_nuke_protect(core);
1900 clk_core_get_boundaries(core, &req.min_rate, &req.max_rate);
1901 req.rate = req_rate;
1903 ret = clk_core_round_rate_nolock(core, &req);
1905 /* restore the protection */
1906 clk_core_rate_restore_protect(core, cnt);
1908 return ret ? 0 : req.rate;
1911 static int clk_core_set_rate_nolock(struct clk_core *core,
1912 unsigned long req_rate)
1914 struct clk_core *top, *fail_clk;
1921 rate = clk_core_req_round_rate_nolock(core, req_rate);
1923 /* bail early if nothing to do */
1924 if (rate == clk_core_get_rate_nolock(core))
1927 /* fail on a direct rate set of a protected provider */
1928 if (clk_core_rate_is_protected(core))
1931 /* calculate new rates and get the topmost changed clock */
1932 top = clk_calc_new_rates(core, req_rate);
1936 ret = clk_pm_runtime_get(core);
1940 /* notify that we are about to change rates */
1941 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
1943 pr_debug("%s: failed to set %s rate\n", __func__,
1945 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
1950 /* change the rates */
1951 clk_change_rate(top);
1953 core->req_rate = req_rate;
1955 clk_pm_runtime_put(core);
1961 * clk_set_rate - specify a new rate for clk
1962 * @clk: the clk whose rate is being changed
1963 * @rate: the new rate for clk
1965 * In the simplest case clk_set_rate will only adjust the rate of clk.
1967 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1968 * propagate up to clk's parent; whether or not this happens depends on the
1969 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1970 * after calling .round_rate then upstream parent propagation is ignored. If
1971 * *parent_rate comes back with a new rate for clk's parent then we propagate
1972 * up to clk's parent and set its rate. Upward propagation will continue
1973 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1974 * .round_rate stops requesting changes to clk's parent_rate.
1976 * Rate changes are accomplished via tree traversal that also recalculates the
1977 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
1979 * Returns 0 on success, -EERROR otherwise.
1981 int clk_set_rate(struct clk *clk, unsigned long rate)
1988 /* prevent racing with updates to the clock topology */
1991 if (clk->exclusive_count)
1992 clk_core_rate_unprotect(clk->core);
1994 ret = clk_core_set_rate_nolock(clk->core, rate);
1996 if (clk->exclusive_count)
1997 clk_core_rate_protect(clk->core);
1999 clk_prepare_unlock();
2003 EXPORT_SYMBOL_GPL(clk_set_rate);
2006 * clk_set_rate_exclusive - specify a new rate get exclusive control
2007 * @clk: the clk whose rate is being changed
2008 * @rate: the new rate for clk
2010 * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
2011 * within a critical section
2013 * This can be used initially to ensure that at least 1 consumer is
2014 * statisfied when several consumers are competing for exclusivity over the
2015 * same clock provider.
2017 * The exclusivity is not applied if setting the rate failed.
2019 * Calls to clk_rate_exclusive_get() should be balanced with calls to
2020 * clk_rate_exclusive_put().
2022 * Returns 0 on success, -EERROR otherwise.
2024 int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
2031 /* prevent racing with updates to the clock topology */
2035 * The temporary protection removal is not here, on purpose
2036 * This function is meant to be used instead of clk_rate_protect,
2037 * so before the consumer code path protect the clock provider
2040 ret = clk_core_set_rate_nolock(clk->core, rate);
2042 clk_core_rate_protect(clk->core);
2043 clk->exclusive_count++;
2046 clk_prepare_unlock();
2050 EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
2053 * clk_set_rate_range - set a rate range for a clock source
2054 * @clk: clock source
2055 * @min: desired minimum clock rate in Hz, inclusive
2056 * @max: desired maximum clock rate in Hz, inclusive
2058 * Returns success (0) or negative errno.
2060 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
2063 unsigned long old_min, old_max, rate;
2069 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
2070 __func__, clk->core->name, clk->dev_id, clk->con_id,
2077 if (clk->exclusive_count)
2078 clk_core_rate_unprotect(clk->core);
2080 /* Save the current values in case we need to rollback the change */
2081 old_min = clk->min_rate;
2082 old_max = clk->max_rate;
2083 clk->min_rate = min;
2084 clk->max_rate = max;
2086 if (!clk_core_check_boundaries(clk->core, min, max)) {
2091 rate = clk_core_get_rate_nolock(clk->core);
2092 if (rate < min || rate > max) {
2095 * We are in bit of trouble here, current rate is outside the
2096 * the requested range. We are going try to request appropriate
2097 * range boundary but there is a catch. It may fail for the
2098 * usual reason (clock broken, clock protected, etc) but also
2100 * - round_rate() was not favorable and fell on the wrong
2101 * side of the boundary
2102 * - the determine_rate() callback does not really check for
2103 * this corner case when determining the rate
2111 ret = clk_core_set_rate_nolock(clk->core, rate);
2113 /* rollback the changes */
2114 clk->min_rate = old_min;
2115 clk->max_rate = old_max;
2120 if (clk->exclusive_count)
2121 clk_core_rate_protect(clk->core);
2123 clk_prepare_unlock();
2127 EXPORT_SYMBOL_GPL(clk_set_rate_range);
2130 * clk_set_min_rate - set a minimum clock rate for a clock source
2131 * @clk: clock source
2132 * @rate: desired minimum clock rate in Hz, inclusive
2134 * Returns success (0) or negative errno.
2136 int clk_set_min_rate(struct clk *clk, unsigned long rate)
2141 return clk_set_rate_range(clk, rate, clk->max_rate);
2143 EXPORT_SYMBOL_GPL(clk_set_min_rate);
2146 * clk_set_max_rate - set a maximum clock rate for a clock source
2147 * @clk: clock source
2148 * @rate: desired maximum clock rate in Hz, inclusive
2150 * Returns success (0) or negative errno.
2152 int clk_set_max_rate(struct clk *clk, unsigned long rate)
2157 return clk_set_rate_range(clk, clk->min_rate, rate);
2159 EXPORT_SYMBOL_GPL(clk_set_max_rate);
2162 * clk_get_parent - return the parent of a clk
2163 * @clk: the clk whose parent gets returned
2165 * Simply returns clk->parent. Returns NULL if clk is NULL.
2167 struct clk *clk_get_parent(struct clk *clk)
2175 /* TODO: Create a per-user clk and change callers to call clk_put */
2176 parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
2177 clk_prepare_unlock();
2181 EXPORT_SYMBOL_GPL(clk_get_parent);
2183 static struct clk_core *__clk_init_parent(struct clk_core *core)
2187 if (core->num_parents > 1 && core->ops->get_parent)
2188 index = core->ops->get_parent(core->hw);
2190 return clk_core_get_parent_by_index(core, index);
2193 static void clk_core_reparent(struct clk_core *core,
2194 struct clk_core *new_parent)
2196 clk_reparent(core, new_parent);
2197 __clk_recalc_accuracies(core);
2198 __clk_recalc_rates(core, POST_RATE_CHANGE);
2201 void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
2206 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
2210 * clk_has_parent - check if a clock is a possible parent for another
2211 * @clk: clock source
2212 * @parent: parent clock source
2214 * This function can be used in drivers that need to check that a clock can be
2215 * the parent of another without actually changing the parent.
2217 * Returns true if @parent is a possible parent for @clk, false otherwise.
2219 bool clk_has_parent(struct clk *clk, struct clk *parent)
2221 struct clk_core *core, *parent_core;
2223 /* NULL clocks should be nops, so return success if either is NULL. */
2224 if (!clk || !parent)
2228 parent_core = parent->core;
2230 /* Optimize for the case where the parent is already the parent. */
2231 if (core->parent == parent_core)
2234 return match_string(core->parent_names, core->num_parents,
2235 parent_core->name) >= 0;
2237 EXPORT_SYMBOL_GPL(clk_has_parent);
2239 static int clk_core_set_parent_nolock(struct clk_core *core,
2240 struct clk_core *parent)
2244 unsigned long p_rate = 0;
2246 lockdep_assert_held(&prepare_lock);
2251 if (core->parent == parent)
2254 /* verify ops for for multi-parent clks */
2255 if (core->num_parents > 1 && !core->ops->set_parent)
2258 /* check that we are allowed to re-parent if the clock is in use */
2259 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
2262 if (clk_core_rate_is_protected(core))
2265 /* try finding the new parent index */
2267 p_index = clk_fetch_parent_index(core, parent);
2269 pr_debug("%s: clk %s can not be parent of clk %s\n",
2270 __func__, parent->name, core->name);
2273 p_rate = parent->rate;
2276 ret = clk_pm_runtime_get(core);
2280 /* propagate PRE_RATE_CHANGE notifications */
2281 ret = __clk_speculate_rates(core, p_rate);
2283 /* abort if a driver objects */
2284 if (ret & NOTIFY_STOP_MASK)
2287 /* do the re-parent */
2288 ret = __clk_set_parent(core, parent, p_index);
2290 /* propagate rate an accuracy recalculation accordingly */
2292 __clk_recalc_rates(core, ABORT_RATE_CHANGE);
2294 __clk_recalc_rates(core, POST_RATE_CHANGE);
2295 __clk_recalc_accuracies(core);
2299 clk_pm_runtime_put(core);
2305 * clk_set_parent - switch the parent of a mux clk
2306 * @clk: the mux clk whose input we are switching
2307 * @parent: the new input to clk
2309 * Re-parent clk to use parent as its new input source. If clk is in
2310 * prepared state, the clk will get enabled for the duration of this call. If
2311 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2312 * that, the reparenting is glitchy in hardware, etc), use the
2313 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2315 * After successfully changing clk's parent clk_set_parent will update the
2316 * clk topology, sysfs topology and propagate rate recalculation via
2317 * __clk_recalc_rates.
2319 * Returns 0 on success, -EERROR otherwise.
2321 int clk_set_parent(struct clk *clk, struct clk *parent)
2330 if (clk->exclusive_count)
2331 clk_core_rate_unprotect(clk->core);
2333 ret = clk_core_set_parent_nolock(clk->core,
2334 parent ? parent->core : NULL);
2336 if (clk->exclusive_count)
2337 clk_core_rate_protect(clk->core);
2339 clk_prepare_unlock();
2343 EXPORT_SYMBOL_GPL(clk_set_parent);
2345 static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
2349 lockdep_assert_held(&prepare_lock);
2354 if (clk_core_rate_is_protected(core))
2357 trace_clk_set_phase(core, degrees);
2359 if (core->ops->set_phase) {
2360 ret = core->ops->set_phase(core->hw, degrees);
2362 core->phase = degrees;
2365 trace_clk_set_phase_complete(core, degrees);
2371 * clk_set_phase - adjust the phase shift of a clock signal
2372 * @clk: clock signal source
2373 * @degrees: number of degrees the signal is shifted
2375 * Shifts the phase of a clock signal by the specified
2376 * degrees. Returns 0 on success, -EERROR otherwise.
2378 * This function makes no distinction about the input or reference
2379 * signal that we adjust the clock signal phase against. For example
2380 * phase locked-loop clock signal generators we may shift phase with
2381 * respect to feedback clock signal input, but for other cases the
2382 * clock phase may be shifted with respect to some other, unspecified
2385 * Additionally the concept of phase shift does not propagate through
2386 * the clock tree hierarchy, which sets it apart from clock rates and
2387 * clock accuracy. A parent clock phase attribute does not have an
2388 * impact on the phase attribute of a child clock.
2390 int clk_set_phase(struct clk *clk, int degrees)
2397 /* sanity check degrees */
2404 if (clk->exclusive_count)
2405 clk_core_rate_unprotect(clk->core);
2407 ret = clk_core_set_phase_nolock(clk->core, degrees);
2409 if (clk->exclusive_count)
2410 clk_core_rate_protect(clk->core);
2412 clk_prepare_unlock();
2416 EXPORT_SYMBOL_GPL(clk_set_phase);
2418 static int clk_core_get_phase(struct clk_core *core)
2423 /* Always try to update cached phase if possible */
2424 if (core->ops->get_phase)
2425 core->phase = core->ops->get_phase(core->hw);
2427 clk_prepare_unlock();
2433 * clk_get_phase - return the phase shift of a clock signal
2434 * @clk: clock signal source
2436 * Returns the phase shift of a clock node in degrees, otherwise returns
2439 int clk_get_phase(struct clk *clk)
2444 return clk_core_get_phase(clk->core);
2446 EXPORT_SYMBOL_GPL(clk_get_phase);
2448 static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
2450 /* Assume a default value of 50% */
2455 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);
2457 static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
2459 struct clk_duty *duty = &core->duty;
2462 if (!core->ops->get_duty_cycle)
2463 return clk_core_update_duty_cycle_parent_nolock(core);
2465 ret = core->ops->get_duty_cycle(core->hw, duty);
2469 /* Don't trust the clock provider too much */
2470 if (duty->den == 0 || duty->num > duty->den) {
2478 clk_core_reset_duty_cycle_nolock(core);
2482 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
2487 core->flags & CLK_DUTY_CYCLE_PARENT) {
2488 ret = clk_core_update_duty_cycle_nolock(core->parent);
2489 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
2491 clk_core_reset_duty_cycle_nolock(core);
2497 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
2498 struct clk_duty *duty);
2500 static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
2501 struct clk_duty *duty)
2505 lockdep_assert_held(&prepare_lock);
2507 if (clk_core_rate_is_protected(core))
2510 trace_clk_set_duty_cycle(core, duty);
2512 if (!core->ops->set_duty_cycle)
2513 return clk_core_set_duty_cycle_parent_nolock(core, duty);
2515 ret = core->ops->set_duty_cycle(core->hw, duty);
2517 memcpy(&core->duty, duty, sizeof(*duty));
2519 trace_clk_set_duty_cycle_complete(core, duty);
2524 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
2525 struct clk_duty *duty)
2530 core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
2531 ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
2532 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
2539 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
2540 * @clk: clock signal source
2541 * @num: numerator of the duty cycle ratio to be applied
2542 * @den: denominator of the duty cycle ratio to be applied
2544 * Apply the duty cycle ratio if the ratio is valid and the clock can
2545 * perform this operation
2547 * Returns (0) on success, a negative errno otherwise.
2549 int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
2552 struct clk_duty duty;
2557 /* sanity check the ratio */
2558 if (den == 0 || num > den)
2566 if (clk->exclusive_count)
2567 clk_core_rate_unprotect(clk->core);
2569 ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
2571 if (clk->exclusive_count)
2572 clk_core_rate_protect(clk->core);
2574 clk_prepare_unlock();
2578 EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
2580 static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
2583 struct clk_duty *duty = &core->duty;
2588 ret = clk_core_update_duty_cycle_nolock(core);
2590 ret = mult_frac(scale, duty->num, duty->den);
2592 clk_prepare_unlock();
2598 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
2599 * @clk: clock signal source
2600 * @scale: scaling factor to be applied to represent the ratio as an integer
2602 * Returns the duty cycle ratio of a clock node multiplied by the provided
2603 * scaling factor, or negative errno on error.
2605 int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
2610 return clk_core_get_scaled_duty_cycle(clk->core, scale);
2612 EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
2615 * clk_is_match - check if two clk's point to the same hardware clock
2616 * @p: clk compared against q
2617 * @q: clk compared against p
2619 * Returns true if the two struct clk pointers both point to the same hardware
2620 * clock node. Put differently, returns true if struct clk *p and struct clk *q
2621 * share the same struct clk_core object.
2623 * Returns false otherwise. Note that two NULL clks are treated as matching.
2625 bool clk_is_match(const struct clk *p, const struct clk *q)
2627 /* trivial case: identical struct clk's or both NULL */
2631 /* true if clk->core pointers match. Avoid dereferencing garbage */
2632 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
2633 if (p->core == q->core)
2638 EXPORT_SYMBOL_GPL(clk_is_match);
2640 /*** debugfs support ***/
2642 #ifdef CONFIG_DEBUG_FS
2643 #include <linux/debugfs.h>
2645 static struct dentry *rootdir;
2646 static int inited = 0;
2647 static DEFINE_MUTEX(clk_debug_lock);
2648 static HLIST_HEAD(clk_debug_list);
2650 static struct hlist_head *orphan_list[] = {
2655 static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
2661 seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu %5d %6d\n",
2663 30 - level * 3, c->name,
2664 c->enable_count, c->prepare_count, c->protect_count,
2665 clk_core_get_rate(c), clk_core_get_accuracy(c),
2666 clk_core_get_phase(c),
2667 clk_core_get_scaled_duty_cycle(c, 100000));
2670 static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
2673 struct clk_core *child;
2678 clk_summary_show_one(s, c, level);
2680 hlist_for_each_entry(child, &c->children, child_node)
2681 clk_summary_show_subtree(s, child, level + 1);
2684 static int clk_summary_show(struct seq_file *s, void *data)
2687 struct hlist_head **lists = (struct hlist_head **)s->private;
2689 seq_puts(s, " enable prepare protect duty\n");
2690 seq_puts(s, " clock count count count rate accuracy phase cycle\n");
2691 seq_puts(s, "---------------------------------------------------------------------------------------------\n");
2695 for (; *lists; lists++)
2696 hlist_for_each_entry(c, *lists, child_node)
2697 clk_summary_show_subtree(s, c, 0);
2699 clk_prepare_unlock();
2703 DEFINE_SHOW_ATTRIBUTE(clk_summary);
2705 static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
2710 /* This should be JSON format, i.e. elements separated with a comma */
2711 seq_printf(s, "\"%s\": { ", c->name);
2712 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
2713 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
2714 seq_printf(s, "\"protect_count\": %d,", c->protect_count);
2715 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate(c));
2716 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c));
2717 seq_printf(s, "\"phase\": %d,", clk_core_get_phase(c));
2718 seq_printf(s, "\"duty_cycle\": %u",
2719 clk_core_get_scaled_duty_cycle(c, 100000));
2722 static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
2724 struct clk_core *child;
2729 clk_dump_one(s, c, level);
2731 hlist_for_each_entry(child, &c->children, child_node) {
2733 clk_dump_subtree(s, child, level + 1);
2739 static int clk_dump_show(struct seq_file *s, void *data)
2742 bool first_node = true;
2743 struct hlist_head **lists = (struct hlist_head **)s->private;
2748 for (; *lists; lists++) {
2749 hlist_for_each_entry(c, *lists, child_node) {
2753 clk_dump_subtree(s, c, 0);
2757 clk_prepare_unlock();
2762 DEFINE_SHOW_ATTRIBUTE(clk_dump);
2764 static const struct {
2768 #define ENTRY(f) { f, #f }
2769 ENTRY(CLK_SET_RATE_GATE),
2770 ENTRY(CLK_SET_PARENT_GATE),
2771 ENTRY(CLK_SET_RATE_PARENT),
2772 ENTRY(CLK_IGNORE_UNUSED),
2773 ENTRY(CLK_IS_BASIC),
2774 ENTRY(CLK_GET_RATE_NOCACHE),
2775 ENTRY(CLK_SET_RATE_NO_REPARENT),
2776 ENTRY(CLK_GET_ACCURACY_NOCACHE),
2777 ENTRY(CLK_RECALC_NEW_RATES),
2778 ENTRY(CLK_SET_RATE_UNGATE),
2779 ENTRY(CLK_IS_CRITICAL),
2780 ENTRY(CLK_OPS_PARENT_ENABLE),
2781 ENTRY(CLK_DUTY_CYCLE_PARENT),
2785 static int clk_flags_show(struct seq_file *s, void *data)
2787 struct clk_core *core = s->private;
2788 unsigned long flags = core->flags;
2791 for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
2792 if (flags & clk_flags[i].flag) {
2793 seq_printf(s, "%s\n", clk_flags[i].name);
2794 flags &= ~clk_flags[i].flag;
2799 seq_printf(s, "0x%lx\n", flags);
2804 DEFINE_SHOW_ATTRIBUTE(clk_flags);
2806 static int possible_parents_show(struct seq_file *s, void *data)
2808 struct clk_core *core = s->private;
2811 for (i = 0; i < core->num_parents - 1; i++)
2812 seq_printf(s, "%s ", core->parent_names[i]);
2814 seq_printf(s, "%s\n", core->parent_names[i]);
2818 DEFINE_SHOW_ATTRIBUTE(possible_parents);
2820 static int clk_duty_cycle_show(struct seq_file *s, void *data)
2822 struct clk_core *core = s->private;
2823 struct clk_duty *duty = &core->duty;
2825 seq_printf(s, "%u/%u\n", duty->num, duty->den);
2829 DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
2831 static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
2833 struct dentry *root;
2835 if (!core || !pdentry)
2838 root = debugfs_create_dir(core->name, pdentry);
2839 core->dentry = root;
2841 debugfs_create_ulong("clk_rate", 0444, root, &core->rate);
2842 debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
2843 debugfs_create_u32("clk_phase", 0444, root, &core->phase);
2844 debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
2845 debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
2846 debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
2847 debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
2848 debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
2849 debugfs_create_file("clk_duty_cycle", 0444, root, core,
2850 &clk_duty_cycle_fops);
2852 if (core->num_parents > 1)
2853 debugfs_create_file("clk_possible_parents", 0444, root, core,
2854 &possible_parents_fops);
2856 if (core->ops->debug_init)
2857 core->ops->debug_init(core->hw, core->dentry);
2861 * clk_debug_register - add a clk node to the debugfs clk directory
2862 * @core: the clk being added to the debugfs clk directory
2864 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
2865 * initialized. Otherwise it bails out early since the debugfs clk directory
2866 * will be created lazily by clk_debug_init as part of a late_initcall.
2868 static void clk_debug_register(struct clk_core *core)
2870 mutex_lock(&clk_debug_lock);
2871 hlist_add_head(&core->debug_node, &clk_debug_list);
2873 clk_debug_create_one(core, rootdir);
2874 mutex_unlock(&clk_debug_lock);
2878 * clk_debug_unregister - remove a clk node from the debugfs clk directory
2879 * @core: the clk being removed from the debugfs clk directory
2881 * Dynamically removes a clk and all its child nodes from the
2882 * debugfs clk directory if clk->dentry points to debugfs created by
2883 * clk_debug_register in __clk_core_init.
2885 static void clk_debug_unregister(struct clk_core *core)
2887 mutex_lock(&clk_debug_lock);
2888 hlist_del_init(&core->debug_node);
2889 debugfs_remove_recursive(core->dentry);
2890 core->dentry = NULL;
2891 mutex_unlock(&clk_debug_lock);
2895 * clk_debug_init - lazily populate the debugfs clk directory
2897 * clks are often initialized very early during boot before memory can be
2898 * dynamically allocated and well before debugfs is setup. This function
2899 * populates the debugfs clk directory once at boot-time when we know that
2900 * debugfs is setup. It should only be called once at boot-time, all other clks
2901 * added dynamically will be done so with clk_debug_register.
2903 static int __init clk_debug_init(void)
2905 struct clk_core *core;
2907 rootdir = debugfs_create_dir("clk", NULL);
2909 debugfs_create_file("clk_summary", 0444, rootdir, &all_lists,
2911 debugfs_create_file("clk_dump", 0444, rootdir, &all_lists,
2913 debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list,
2915 debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list,
2918 mutex_lock(&clk_debug_lock);
2919 hlist_for_each_entry(core, &clk_debug_list, debug_node)
2920 clk_debug_create_one(core, rootdir);
2923 mutex_unlock(&clk_debug_lock);
2927 late_initcall(clk_debug_init);
2929 static inline void clk_debug_register(struct clk_core *core) { }
2930 static inline void clk_debug_reparent(struct clk_core *core,
2931 struct clk_core *new_parent)
2934 static inline void clk_debug_unregister(struct clk_core *core)
2940 * __clk_core_init - initialize the data structures in a struct clk_core
2941 * @core: clk_core being initialized
2943 * Initializes the lists in struct clk_core, queries the hardware for the
2944 * parent and rate and sets them both.
2946 static int __clk_core_init(struct clk_core *core)
2949 struct clk_core *orphan;
2950 struct hlist_node *tmp2;
2958 ret = clk_pm_runtime_get(core);
2962 /* check to see if a clock with this name is already registered */
2963 if (clk_core_lookup(core->name)) {
2964 pr_debug("%s: clk %s already initialized\n",
2965 __func__, core->name);
2970 /* check that clk_ops are sane. See Documentation/driver-api/clk.rst */
2971 if (core->ops->set_rate &&
2972 !((core->ops->round_rate || core->ops->determine_rate) &&
2973 core->ops->recalc_rate)) {
2974 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
2975 __func__, core->name);
2980 if (core->ops->set_parent && !core->ops->get_parent) {
2981 pr_err("%s: %s must implement .get_parent & .set_parent\n",
2982 __func__, core->name);
2987 if (core->num_parents > 1 && !core->ops->get_parent) {
2988 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
2989 __func__, core->name);
2994 if (core->ops->set_rate_and_parent &&
2995 !(core->ops->set_parent && core->ops->set_rate)) {
2996 pr_err("%s: %s must implement .set_parent & .set_rate\n",
2997 __func__, core->name);
3002 /* throw a WARN if any entries in parent_names are NULL */
3003 for (i = 0; i < core->num_parents; i++)
3004 WARN(!core->parent_names[i],
3005 "%s: invalid NULL in %s's .parent_names\n",
3006 __func__, core->name);
3008 core->parent = __clk_init_parent(core);
3011 * Populate core->parent if parent has already been clk_core_init'd. If
3012 * parent has not yet been clk_core_init'd then place clk in the orphan
3013 * list. If clk doesn't have any parents then place it in the root
3016 * Every time a new clk is clk_init'd then we walk the list of orphan
3017 * clocks and re-parent any that are children of the clock currently
3021 hlist_add_head(&core->child_node,
3022 &core->parent->children);
3023 core->orphan = core->parent->orphan;
3024 } else if (!core->num_parents) {
3025 hlist_add_head(&core->child_node, &clk_root_list);
3026 core->orphan = false;
3028 hlist_add_head(&core->child_node, &clk_orphan_list);
3029 core->orphan = true;
3033 * optional platform-specific magic
3035 * The .init callback is not used by any of the basic clock types, but
3036 * exists for weird hardware that must perform initialization magic.
3037 * Please consider other ways of solving initialization problems before
3038 * using this callback, as its use is discouraged.
3040 if (core->ops->init)
3041 core->ops->init(core->hw);
3044 * Set clk's accuracy. The preferred method is to use
3045 * .recalc_accuracy. For simple clocks and lazy developers the default
3046 * fallback is to use the parent's accuracy. If a clock doesn't have a
3047 * parent (or is orphaned) then accuracy is set to zero (perfect
3050 if (core->ops->recalc_accuracy)
3051 core->accuracy = core->ops->recalc_accuracy(core->hw,
3052 __clk_get_accuracy(core->parent));
3053 else if (core->parent)
3054 core->accuracy = core->parent->accuracy;
3060 * Since a phase is by definition relative to its parent, just
3061 * query the current clock phase, or just assume it's in phase.
3063 if (core->ops->get_phase)
3064 core->phase = core->ops->get_phase(core->hw);
3069 * Set clk's duty cycle.
3071 clk_core_update_duty_cycle_nolock(core);
3074 * Set clk's rate. The preferred method is to use .recalc_rate. For
3075 * simple clocks and lazy developers the default fallback is to use the
3076 * parent's rate. If a clock doesn't have a parent (or is orphaned)
3077 * then rate is set to zero.
3079 if (core->ops->recalc_rate)
3080 rate = core->ops->recalc_rate(core->hw,
3081 clk_core_get_rate_nolock(core->parent));
3082 else if (core->parent)
3083 rate = core->parent->rate;
3086 core->rate = core->req_rate = rate;
3089 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
3090 * don't get accidentally disabled when walking the orphan tree and
3091 * reparenting clocks
3093 if (core->flags & CLK_IS_CRITICAL) {
3094 unsigned long flags;
3096 ret = clk_core_prepare(core);
3100 flags = clk_enable_lock();
3101 ret = clk_core_enable(core);
3102 clk_enable_unlock(flags);
3104 clk_core_unprepare(core);
3110 * walk the list of orphan clocks and reparent any that newly finds a
3113 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
3114 struct clk_core *parent = __clk_init_parent(orphan);
3117 * We need to use __clk_set_parent_before() and _after() to
3118 * to properly migrate any prepare/enable count of the orphan
3119 * clock. This is important for CLK_IS_CRITICAL clocks, which
3120 * are enabled during init but might not have a parent yet.
3123 /* update the clk tree topology */
3124 __clk_set_parent_before(orphan, parent);
3125 __clk_set_parent_after(orphan, parent, NULL);
3126 __clk_recalc_accuracies(orphan);
3127 __clk_recalc_rates(orphan, 0);
3131 kref_init(&core->ref);
3133 clk_pm_runtime_put(core);
3136 hlist_del_init(&core->child_node);
3138 clk_prepare_unlock();
3141 clk_debug_register(core);
3146 struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,
3151 /* This is to allow this function to be chained to others */
3152 if (IS_ERR_OR_NULL(hw))
3153 return ERR_CAST(hw);
3155 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
3157 return ERR_PTR(-ENOMEM);
3159 clk->core = hw->core;
3160 clk->dev_id = dev_id;
3161 clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
3162 clk->max_rate = ULONG_MAX;
3165 hlist_add_head(&clk->clks_node, &hw->core->clks);
3166 clk_prepare_unlock();
3171 /* keep in sync with __clk_put */
3172 void __clk_free_clk(struct clk *clk)
3175 hlist_del(&clk->clks_node);
3176 clk_prepare_unlock();
3178 kfree_const(clk->con_id);
3183 * clk_register - allocate a new clock, register it and return an opaque cookie
3184 * @dev: device that is registering this clock
3185 * @hw: link to hardware-specific clock data
3187 * clk_register is the primary interface for populating the clock tree with new
3188 * clock nodes. It returns a pointer to the newly allocated struct clk which
3189 * cannot be dereferenced by driver code but may be used in conjunction with the
3190 * rest of the clock API. In the event of an error clk_register will return an
3191 * error code; drivers must test for an error code after calling clk_register.
3193 struct clk *clk_register(struct device *dev, struct clk_hw *hw)
3196 struct clk_core *core;
3198 core = kzalloc(sizeof(*core), GFP_KERNEL);
3204 core->name = kstrdup_const(hw->init->name, GFP_KERNEL);
3210 if (WARN_ON(!hw->init->ops)) {
3214 core->ops = hw->init->ops;
3216 if (dev && pm_runtime_enabled(dev))
3218 if (dev && dev->driver)
3219 core->owner = dev->driver->owner;
3221 core->flags = hw->init->flags;
3222 core->num_parents = hw->init->num_parents;
3224 core->max_rate = ULONG_MAX;
3227 /* allocate local copy in case parent_names is __initdata */
3228 core->parent_names = kcalloc(core->num_parents, sizeof(char *),
3231 if (!core->parent_names) {
3233 goto fail_parent_names;
3237 /* copy each string name in case parent_names is __initdata */
3238 for (i = 0; i < core->num_parents; i++) {
3239 core->parent_names[i] = kstrdup_const(hw->init->parent_names[i],
3241 if (!core->parent_names[i]) {
3243 goto fail_parent_names_copy;
3247 /* avoid unnecessary string look-ups of clk_core's possible parents. */
3248 core->parents = kcalloc(core->num_parents, sizeof(*core->parents),
3250 if (!core->parents) {
3255 INIT_HLIST_HEAD(&core->clks);
3257 hw->clk = __clk_create_clk(hw, NULL, NULL);
3258 if (IS_ERR(hw->clk)) {
3259 ret = PTR_ERR(hw->clk);
3263 ret = __clk_core_init(core);
3267 __clk_free_clk(hw->clk);
3271 kfree(core->parents);
3272 fail_parent_names_copy:
3274 kfree_const(core->parent_names[i]);
3275 kfree(core->parent_names);
3278 kfree_const(core->name);
3282 return ERR_PTR(ret);
3284 EXPORT_SYMBOL_GPL(clk_register);
3287 * clk_hw_register - register a clk_hw and return an error code
3288 * @dev: device that is registering this clock
3289 * @hw: link to hardware-specific clock data
3291 * clk_hw_register is the primary interface for populating the clock tree with
3292 * new clock nodes. It returns an integer equal to zero indicating success or
3293 * less than zero indicating failure. Drivers must test for an error code after
3294 * calling clk_hw_register().
3296 int clk_hw_register(struct device *dev, struct clk_hw *hw)
3298 return PTR_ERR_OR_ZERO(clk_register(dev, hw));
3300 EXPORT_SYMBOL_GPL(clk_hw_register);
3302 /* Free memory allocated for a clock. */
3303 static void __clk_release(struct kref *ref)
3305 struct clk_core *core = container_of(ref, struct clk_core, ref);
3306 int i = core->num_parents;
3308 lockdep_assert_held(&prepare_lock);
3310 kfree(core->parents);
3312 kfree_const(core->parent_names[i]);
3314 kfree(core->parent_names);
3315 kfree_const(core->name);
3320 * Empty clk_ops for unregistered clocks. These are used temporarily
3321 * after clk_unregister() was called on a clock and until last clock
3322 * consumer calls clk_put() and the struct clk object is freed.
3324 static int clk_nodrv_prepare_enable(struct clk_hw *hw)
3329 static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
3334 static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
3335 unsigned long parent_rate)
3340 static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
3345 static const struct clk_ops clk_nodrv_ops = {
3346 .enable = clk_nodrv_prepare_enable,
3347 .disable = clk_nodrv_disable_unprepare,
3348 .prepare = clk_nodrv_prepare_enable,
3349 .unprepare = clk_nodrv_disable_unprepare,
3350 .set_rate = clk_nodrv_set_rate,
3351 .set_parent = clk_nodrv_set_parent,
3354 static void clk_core_evict_parent_cache_subtree(struct clk_core *root,
3355 struct clk_core *target)
3358 struct clk_core *child;
3360 for (i = 0; i < root->num_parents; i++)
3361 if (root->parents[i] == target)
3362 root->parents[i] = NULL;
3364 hlist_for_each_entry(child, &root->children, child_node)
3365 clk_core_evict_parent_cache_subtree(child, target);
3368 /* Remove this clk from all parent caches */
3369 static void clk_core_evict_parent_cache(struct clk_core *core)
3371 struct hlist_head **lists;
3372 struct clk_core *root;
3374 lockdep_assert_held(&prepare_lock);
3376 for (lists = all_lists; *lists; lists++)
3377 hlist_for_each_entry(root, *lists, child_node)
3378 clk_core_evict_parent_cache_subtree(root, core);
3383 * clk_unregister - unregister a currently registered clock
3384 * @clk: clock to unregister
3386 void clk_unregister(struct clk *clk)
3388 unsigned long flags;
3390 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
3393 clk_debug_unregister(clk->core);
3397 if (clk->core->ops == &clk_nodrv_ops) {
3398 pr_err("%s: unregistered clock: %s\n", __func__,
3403 * Assign empty clock ops for consumers that might still hold
3404 * a reference to this clock.
3406 flags = clk_enable_lock();
3407 clk->core->ops = &clk_nodrv_ops;
3408 clk_enable_unlock(flags);
3410 if (!hlist_empty(&clk->core->children)) {
3411 struct clk_core *child;
3412 struct hlist_node *t;
3414 /* Reparent all children to the orphan list. */
3415 hlist_for_each_entry_safe(child, t, &clk->core->children,
3417 clk_core_set_parent_nolock(child, NULL);
3420 clk_core_evict_parent_cache(clk->core);
3422 hlist_del_init(&clk->core->child_node);
3424 if (clk->core->prepare_count)
3425 pr_warn("%s: unregistering prepared clock: %s\n",
3426 __func__, clk->core->name);
3428 if (clk->core->protect_count)
3429 pr_warn("%s: unregistering protected clock: %s\n",
3430 __func__, clk->core->name);
3432 kref_put(&clk->core->ref, __clk_release);
3434 clk_prepare_unlock();
3436 EXPORT_SYMBOL_GPL(clk_unregister);
3439 * clk_hw_unregister - unregister a currently registered clk_hw
3440 * @hw: hardware-specific clock data to unregister
3442 void clk_hw_unregister(struct clk_hw *hw)
3444 clk_unregister(hw->clk);
3446 EXPORT_SYMBOL_GPL(clk_hw_unregister);
3448 static void devm_clk_release(struct device *dev, void *res)
3450 clk_unregister(*(struct clk **)res);
3453 static void devm_clk_hw_release(struct device *dev, void *res)
3455 clk_hw_unregister(*(struct clk_hw **)res);
3459 * devm_clk_register - resource managed clk_register()
3460 * @dev: device that is registering this clock
3461 * @hw: link to hardware-specific clock data
3463 * Managed clk_register(). Clocks returned from this function are
3464 * automatically clk_unregister()ed on driver detach. See clk_register() for
3467 struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
3472 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
3474 return ERR_PTR(-ENOMEM);
3476 clk = clk_register(dev, hw);
3479 devres_add(dev, clkp);
3486 EXPORT_SYMBOL_GPL(devm_clk_register);
3489 * devm_clk_hw_register - resource managed clk_hw_register()
3490 * @dev: device that is registering this clock
3491 * @hw: link to hardware-specific clock data
3493 * Managed clk_hw_register(). Clocks registered by this function are
3494 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
3495 * for more information.
3497 int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
3499 struct clk_hw **hwp;
3502 hwp = devres_alloc(devm_clk_hw_release, sizeof(*hwp), GFP_KERNEL);
3506 ret = clk_hw_register(dev, hw);
3509 devres_add(dev, hwp);
3516 EXPORT_SYMBOL_GPL(devm_clk_hw_register);
3518 static int devm_clk_match(struct device *dev, void *res, void *data)
3520 struct clk *c = res;
3526 static int devm_clk_hw_match(struct device *dev, void *res, void *data)
3528 struct clk_hw *hw = res;
3536 * devm_clk_unregister - resource managed clk_unregister()
3537 * @clk: clock to unregister
3539 * Deallocate a clock allocated with devm_clk_register(). Normally
3540 * this function will not need to be called and the resource management
3541 * code will ensure that the resource is freed.
3543 void devm_clk_unregister(struct device *dev, struct clk *clk)
3545 WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
3547 EXPORT_SYMBOL_GPL(devm_clk_unregister);
3550 * devm_clk_hw_unregister - resource managed clk_hw_unregister()
3551 * @dev: device that is unregistering the hardware-specific clock data
3552 * @hw: link to hardware-specific clock data
3554 * Unregister a clk_hw registered with devm_clk_hw_register(). Normally
3555 * this function will not need to be called and the resource management
3556 * code will ensure that the resource is freed.
3558 void devm_clk_hw_unregister(struct device *dev, struct clk_hw *hw)
3560 WARN_ON(devres_release(dev, devm_clk_hw_release, devm_clk_hw_match,
3563 EXPORT_SYMBOL_GPL(devm_clk_hw_unregister);
3568 int __clk_get(struct clk *clk)
3570 struct clk_core *core = !clk ? NULL : clk->core;
3573 if (!try_module_get(core->owner))
3576 kref_get(&core->ref);
3581 /* keep in sync with __clk_free_clk */
3582 void __clk_put(struct clk *clk)
3584 struct module *owner;
3586 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
3592 * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
3593 * given user should be balanced with calls to clk_rate_exclusive_put()
3594 * and by that same consumer
3596 if (WARN_ON(clk->exclusive_count)) {
3597 /* We voiced our concern, let's sanitize the situation */
3598 clk->core->protect_count -= (clk->exclusive_count - 1);
3599 clk_core_rate_unprotect(clk->core);
3600 clk->exclusive_count = 0;
3603 hlist_del(&clk->clks_node);
3604 if (clk->min_rate > clk->core->req_rate ||
3605 clk->max_rate < clk->core->req_rate)
3606 clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
3608 owner = clk->core->owner;
3609 kref_put(&clk->core->ref, __clk_release);
3611 clk_prepare_unlock();
3615 kfree_const(clk->con_id);
3619 /*** clk rate change notifiers ***/
3622 * clk_notifier_register - add a clk rate change notifier
3623 * @clk: struct clk * to watch
3624 * @nb: struct notifier_block * with callback info
3626 * Request notification when clk's rate changes. This uses an SRCU
3627 * notifier because we want it to block and notifier unregistrations are
3628 * uncommon. The callbacks associated with the notifier must not
3629 * re-enter into the clk framework by calling any top-level clk APIs;
3630 * this will cause a nested prepare_lock mutex.
3632 * In all notification cases (pre, post and abort rate change) the original
3633 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
3634 * and the new frequency is passed via struct clk_notifier_data.new_rate.
3636 * clk_notifier_register() must be called from non-atomic context.
3637 * Returns -EINVAL if called with null arguments, -ENOMEM upon
3638 * allocation failure; otherwise, passes along the return value of
3639 * srcu_notifier_chain_register().
3641 int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
3643 struct clk_notifier *cn;
3651 /* search the list of notifiers for this clk */
3652 list_for_each_entry(cn, &clk_notifier_list, node)
3656 /* if clk wasn't in the notifier list, allocate new clk_notifier */
3657 cn = kzalloc(sizeof(*cn), GFP_KERNEL);
3662 srcu_init_notifier_head(&cn->notifier_head);
3664 list_add(&cn->node, &clk_notifier_list);
3667 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
3669 clk->core->notifier_count++;
3672 clk_prepare_unlock();
3676 EXPORT_SYMBOL_GPL(clk_notifier_register);
3679 * clk_notifier_unregister - remove a clk rate change notifier
3680 * @clk: struct clk *
3681 * @nb: struct notifier_block * with callback info
3683 * Request no further notification for changes to 'clk' and frees memory
3684 * allocated in clk_notifier_register.
3686 * Returns -EINVAL if called with null arguments; otherwise, passes
3687 * along the return value of srcu_notifier_chain_unregister().
3689 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
3691 struct clk_notifier *cn;
3699 list_for_each_entry(cn, &clk_notifier_list, node) {
3700 if (cn->clk == clk) {
3701 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
3703 clk->core->notifier_count--;
3705 /* XXX the notifier code should handle this better */
3706 if (!cn->notifier_head.head) {
3707 srcu_cleanup_notifier_head(&cn->notifier_head);
3708 list_del(&cn->node);
3715 clk_prepare_unlock();
3719 EXPORT_SYMBOL_GPL(clk_notifier_unregister);
3723 * struct of_clk_provider - Clock provider registration structure
3724 * @link: Entry in global list of clock providers
3725 * @node: Pointer to device tree node of clock provider
3726 * @get: Get clock callback. Returns NULL or a struct clk for the
3727 * given clock specifier
3728 * @data: context pointer to be passed into @get callback
3730 struct of_clk_provider {
3731 struct list_head link;
3733 struct device_node *node;
3734 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
3735 struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
3739 static const struct of_device_id __clk_of_table_sentinel
3740 __used __section(__clk_of_table_end);
3742 static LIST_HEAD(of_clk_providers);
3743 static DEFINE_MUTEX(of_clk_mutex);
3745 struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
3750 EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
3752 struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
3756 EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
3758 struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
3760 struct clk_onecell_data *clk_data = data;
3761 unsigned int idx = clkspec->args[0];
3763 if (idx >= clk_data->clk_num) {
3764 pr_err("%s: invalid clock index %u\n", __func__, idx);
3765 return ERR_PTR(-EINVAL);
3768 return clk_data->clks[idx];
3770 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
3773 of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
3775 struct clk_hw_onecell_data *hw_data = data;
3776 unsigned int idx = clkspec->args[0];
3778 if (idx >= hw_data->num) {
3779 pr_err("%s: invalid index %u\n", __func__, idx);
3780 return ERR_PTR(-EINVAL);
3783 return hw_data->hws[idx];
3785 EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
3788 * of_clk_add_provider() - Register a clock provider for a node
3789 * @np: Device node pointer associated with clock provider
3790 * @clk_src_get: callback for decoding clock
3791 * @data: context pointer for @clk_src_get callback.
3793 int of_clk_add_provider(struct device_node *np,
3794 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
3798 struct of_clk_provider *cp;
3801 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
3805 cp->node = of_node_get(np);
3807 cp->get = clk_src_get;
3809 mutex_lock(&of_clk_mutex);
3810 list_add(&cp->link, &of_clk_providers);
3811 mutex_unlock(&of_clk_mutex);
3812 pr_debug("Added clock from %pOF\n", np);
3814 ret = of_clk_set_defaults(np, true);
3816 of_clk_del_provider(np);
3820 EXPORT_SYMBOL_GPL(of_clk_add_provider);
3823 * of_clk_add_hw_provider() - Register a clock provider for a node
3824 * @np: Device node pointer associated with clock provider
3825 * @get: callback for decoding clk_hw
3826 * @data: context pointer for @get callback.
3828 int of_clk_add_hw_provider(struct device_node *np,
3829 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
3833 struct of_clk_provider *cp;
3836 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
3840 cp->node = of_node_get(np);
3844 mutex_lock(&of_clk_mutex);
3845 list_add(&cp->link, &of_clk_providers);
3846 mutex_unlock(&of_clk_mutex);
3847 pr_debug("Added clk_hw provider from %pOF\n", np);
3849 ret = of_clk_set_defaults(np, true);
3851 of_clk_del_provider(np);
3855 EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
3857 static void devm_of_clk_release_provider(struct device *dev, void *res)
3859 of_clk_del_provider(*(struct device_node **)res);
3862 int devm_of_clk_add_hw_provider(struct device *dev,
3863 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
3867 struct device_node **ptr, *np;
3870 ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
3876 ret = of_clk_add_hw_provider(np, get, data);
3879 devres_add(dev, ptr);
3886 EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);
3889 * of_clk_del_provider() - Remove a previously registered clock provider
3890 * @np: Device node pointer associated with clock provider
3892 void of_clk_del_provider(struct device_node *np)
3894 struct of_clk_provider *cp;
3896 mutex_lock(&of_clk_mutex);
3897 list_for_each_entry(cp, &of_clk_providers, link) {
3898 if (cp->node == np) {
3899 list_del(&cp->link);
3900 of_node_put(cp->node);
3905 mutex_unlock(&of_clk_mutex);
3907 EXPORT_SYMBOL_GPL(of_clk_del_provider);
3909 static int devm_clk_provider_match(struct device *dev, void *res, void *data)
3911 struct device_node **np = res;
3913 if (WARN_ON(!np || !*np))
3919 void devm_of_clk_del_provider(struct device *dev)
3923 ret = devres_release(dev, devm_of_clk_release_provider,
3924 devm_clk_provider_match, dev->of_node);
3928 EXPORT_SYMBOL(devm_of_clk_del_provider);
3930 static struct clk_hw *
3931 __of_clk_get_hw_from_provider(struct of_clk_provider *provider,
3932 struct of_phandle_args *clkspec)
3936 if (provider->get_hw)
3937 return provider->get_hw(clkspec, provider->data);
3939 clk = provider->get(clkspec, provider->data);
3941 return ERR_CAST(clk);
3942 return __clk_get_hw(clk);
3945 struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec,
3946 const char *dev_id, const char *con_id)
3948 struct of_clk_provider *provider;
3949 struct clk *clk = ERR_PTR(-EPROBE_DEFER);
3953 return ERR_PTR(-EINVAL);
3955 /* Check if we have such a provider in our array */
3956 mutex_lock(&of_clk_mutex);
3957 list_for_each_entry(provider, &of_clk_providers, link) {
3958 if (provider->node == clkspec->np) {
3959 hw = __of_clk_get_hw_from_provider(provider, clkspec);
3960 clk = __clk_create_clk(hw, dev_id, con_id);
3964 if (!__clk_get(clk)) {
3965 __clk_free_clk(clk);
3966 clk = ERR_PTR(-ENOENT);
3972 mutex_unlock(&of_clk_mutex);
3978 * of_clk_get_from_provider() - Lookup a clock from a clock provider
3979 * @clkspec: pointer to a clock specifier data structure
3981 * This function looks up a struct clk from the registered list of clock
3982 * providers, an input is a clock specifier data structure as returned
3983 * from the of_parse_phandle_with_args() function call.
3985 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
3987 return __of_clk_get_from_provider(clkspec, NULL, __func__);
3989 EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
3992 * of_clk_get_parent_count() - Count the number of clocks a device node has
3993 * @np: device node to count
3995 * Returns: The number of clocks that are possible parents of this node
3997 unsigned int of_clk_get_parent_count(struct device_node *np)
4001 count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
4007 EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
4009 const char *of_clk_get_parent_name(struct device_node *np, int index)
4011 struct of_phandle_args clkspec;
4012 struct property *prop;
4013 const char *clk_name;
4020 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
4025 index = clkspec.args_count ? clkspec.args[0] : 0;
4028 /* if there is an indices property, use it to transfer the index
4029 * specified into an array offset for the clock-output-names property.
4031 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
4038 /* We went off the end of 'clock-indices' without finding it */
4042 if (of_property_read_string_index(clkspec.np, "clock-output-names",
4046 * Best effort to get the name if the clock has been
4047 * registered with the framework. If the clock isn't
4048 * registered, we return the node name as the name of
4049 * the clock as long as #clock-cells = 0.
4051 clk = of_clk_get_from_provider(&clkspec);
4053 if (clkspec.args_count == 0)
4054 clk_name = clkspec.np->name;
4058 clk_name = __clk_get_name(clk);
4064 of_node_put(clkspec.np);
4067 EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
4070 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
4072 * @np: Device node pointer associated with clock provider
4073 * @parents: pointer to char array that hold the parents' names
4074 * @size: size of the @parents array
4076 * Return: number of parents for the clock node.
4078 int of_clk_parent_fill(struct device_node *np, const char **parents,
4083 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
4088 EXPORT_SYMBOL_GPL(of_clk_parent_fill);
4090 struct clock_provider {
4091 void (*clk_init_cb)(struct device_node *);
4092 struct device_node *np;
4093 struct list_head node;
4097 * This function looks for a parent clock. If there is one, then it
4098 * checks that the provider for this parent clock was initialized, in
4099 * this case the parent clock will be ready.
4101 static int parent_ready(struct device_node *np)
4106 struct clk *clk = of_clk_get(np, i);
4108 /* this parent is ready we can check the next one */
4115 /* at least one parent is not ready, we exit now */
4116 if (PTR_ERR(clk) == -EPROBE_DEFER)
4120 * Here we make assumption that the device tree is
4121 * written correctly. So an error means that there is
4122 * no more parent. As we didn't exit yet, then the
4123 * previous parent are ready. If there is no clock
4124 * parent, no need to wait for them, then we can
4125 * consider their absence as being ready
4132 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
4133 * @np: Device node pointer associated with clock provider
4134 * @index: clock index
4135 * @flags: pointer to top-level framework flags
4137 * Detects if the clock-critical property exists and, if so, sets the
4138 * corresponding CLK_IS_CRITICAL flag.
4140 * Do not use this function. It exists only for legacy Device Tree
4141 * bindings, such as the one-clock-per-node style that are outdated.
4142 * Those bindings typically put all clock data into .dts and the Linux
4143 * driver has no clock data, thus making it impossible to set this flag
4144 * correctly from the driver. Only those drivers may call
4145 * of_clk_detect_critical from their setup functions.
4147 * Return: error code or zero on success
4149 int of_clk_detect_critical(struct device_node *np,
4150 int index, unsigned long *flags)
4152 struct property *prop;
4159 of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
4161 *flags |= CLK_IS_CRITICAL;
4167 * of_clk_init() - Scan and init clock providers from the DT
4168 * @matches: array of compatible values and init functions for providers.
4170 * This function scans the device tree for matching clock providers
4171 * and calls their initialization functions. It also does it by trying
4172 * to follow the dependencies.
4174 void __init of_clk_init(const struct of_device_id *matches)
4176 const struct of_device_id *match;
4177 struct device_node *np;
4178 struct clock_provider *clk_provider, *next;
4181 LIST_HEAD(clk_provider_list);
4184 matches = &__clk_of_table;
4186 /* First prepare the list of the clocks providers */
4187 for_each_matching_node_and_match(np, matches, &match) {
4188 struct clock_provider *parent;
4190 if (!of_device_is_available(np))
4193 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
4195 list_for_each_entry_safe(clk_provider, next,
4196 &clk_provider_list, node) {
4197 list_del(&clk_provider->node);
4198 of_node_put(clk_provider->np);
4199 kfree(clk_provider);
4205 parent->clk_init_cb = match->data;
4206 parent->np = of_node_get(np);
4207 list_add_tail(&parent->node, &clk_provider_list);
4210 while (!list_empty(&clk_provider_list)) {
4211 is_init_done = false;
4212 list_for_each_entry_safe(clk_provider, next,
4213 &clk_provider_list, node) {
4214 if (force || parent_ready(clk_provider->np)) {
4216 /* Don't populate platform devices */
4217 of_node_set_flag(clk_provider->np,
4220 clk_provider->clk_init_cb(clk_provider->np);
4221 of_clk_set_defaults(clk_provider->np, true);
4223 list_del(&clk_provider->node);
4224 of_node_put(clk_provider->np);
4225 kfree(clk_provider);
4226 is_init_done = true;
4231 * We didn't manage to initialize any of the
4232 * remaining providers during the last loop, so now we
4233 * initialize all the remaining ones unconditionally
4234 * in case the clock parent was not mandatory