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 /*** private data structures ***/
47 const struct clk_ops *ops;
51 struct clk_core *parent;
52 const char **parent_names;
53 struct clk_core **parents;
57 unsigned long req_rate;
58 unsigned long new_rate;
59 struct clk_core *new_parent;
60 struct clk_core *new_child;
63 unsigned int enable_count;
64 unsigned int prepare_count;
65 unsigned int protect_count;
66 unsigned long min_rate;
67 unsigned long max_rate;
68 unsigned long accuracy;
71 struct hlist_head children;
72 struct hlist_node child_node;
73 struct hlist_head clks;
74 unsigned int notifier_count;
75 #ifdef CONFIG_DEBUG_FS
76 struct dentry *dentry;
77 struct hlist_node debug_node;
82 #define CREATE_TRACE_POINTS
83 #include <trace/events/clk.h>
86 struct clk_core *core;
89 unsigned long min_rate;
90 unsigned long max_rate;
91 unsigned int exclusive_count;
92 struct hlist_node clks_node;
96 static int clk_pm_runtime_get(struct clk_core *core)
103 ret = pm_runtime_get_sync(core->dev);
104 return ret < 0 ? ret : 0;
107 static void clk_pm_runtime_put(struct clk_core *core)
112 pm_runtime_put_sync(core->dev);
116 static void clk_prepare_lock(void)
118 if (!mutex_trylock(&prepare_lock)) {
119 if (prepare_owner == current) {
123 mutex_lock(&prepare_lock);
125 WARN_ON_ONCE(prepare_owner != NULL);
126 WARN_ON_ONCE(prepare_refcnt != 0);
127 prepare_owner = current;
131 static void clk_prepare_unlock(void)
133 WARN_ON_ONCE(prepare_owner != current);
134 WARN_ON_ONCE(prepare_refcnt == 0);
136 if (--prepare_refcnt)
138 prepare_owner = NULL;
139 mutex_unlock(&prepare_lock);
142 static unsigned long clk_enable_lock(void)
143 __acquires(enable_lock)
148 * On UP systems, spin_trylock_irqsave() always returns true, even if
149 * we already hold the lock. So, in that case, we rely only on
150 * reference counting.
152 if (!IS_ENABLED(CONFIG_SMP) ||
153 !spin_trylock_irqsave(&enable_lock, flags)) {
154 if (enable_owner == current) {
156 __acquire(enable_lock);
157 if (!IS_ENABLED(CONFIG_SMP))
158 local_save_flags(flags);
161 spin_lock_irqsave(&enable_lock, flags);
163 WARN_ON_ONCE(enable_owner != NULL);
164 WARN_ON_ONCE(enable_refcnt != 0);
165 enable_owner = current;
170 static void clk_enable_unlock(unsigned long flags)
171 __releases(enable_lock)
173 WARN_ON_ONCE(enable_owner != current);
174 WARN_ON_ONCE(enable_refcnt == 0);
176 if (--enable_refcnt) {
177 __release(enable_lock);
181 spin_unlock_irqrestore(&enable_lock, flags);
184 static bool clk_core_rate_is_protected(struct clk_core *core)
186 return core->protect_count;
189 static bool clk_core_is_prepared(struct clk_core *core)
194 * .is_prepared is optional for clocks that can prepare
195 * fall back to software usage counter if it is missing
197 if (!core->ops->is_prepared)
198 return core->prepare_count;
200 if (!clk_pm_runtime_get(core)) {
201 ret = core->ops->is_prepared(core->hw);
202 clk_pm_runtime_put(core);
208 static bool clk_core_is_enabled(struct clk_core *core)
213 * .is_enabled is only mandatory for clocks that gate
214 * fall back to software usage counter if .is_enabled is missing
216 if (!core->ops->is_enabled)
217 return core->enable_count;
220 * Check if clock controller's device is runtime active before
221 * calling .is_enabled callback. If not, assume that clock is
222 * disabled, because we might be called from atomic context, from
223 * which pm_runtime_get() is not allowed.
224 * This function is called mainly from clk_disable_unused_subtree,
225 * which ensures proper runtime pm activation of controller before
226 * taking enable spinlock, but the below check is needed if one tries
227 * to call it from other places.
230 pm_runtime_get_noresume(core->dev);
231 if (!pm_runtime_active(core->dev)) {
237 ret = core->ops->is_enabled(core->hw);
240 pm_runtime_put(core->dev);
245 /*** helper functions ***/
247 const char *__clk_get_name(const struct clk *clk)
249 return !clk ? NULL : clk->core->name;
251 EXPORT_SYMBOL_GPL(__clk_get_name);
253 const char *clk_hw_get_name(const struct clk_hw *hw)
255 return hw->core->name;
257 EXPORT_SYMBOL_GPL(clk_hw_get_name);
259 struct clk_hw *__clk_get_hw(struct clk *clk)
261 return !clk ? NULL : clk->core->hw;
263 EXPORT_SYMBOL_GPL(__clk_get_hw);
265 unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
267 return hw->core->num_parents;
269 EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
271 struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
273 return hw->core->parent ? hw->core->parent->hw : NULL;
275 EXPORT_SYMBOL_GPL(clk_hw_get_parent);
277 static struct clk_core *__clk_lookup_subtree(const char *name,
278 struct clk_core *core)
280 struct clk_core *child;
281 struct clk_core *ret;
283 if (!strcmp(core->name, name))
286 hlist_for_each_entry(child, &core->children, child_node) {
287 ret = __clk_lookup_subtree(name, child);
295 static struct clk_core *clk_core_lookup(const char *name)
297 struct clk_core *root_clk;
298 struct clk_core *ret;
303 /* search the 'proper' clk tree first */
304 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
305 ret = __clk_lookup_subtree(name, root_clk);
310 /* if not found, then search the orphan tree */
311 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
312 ret = __clk_lookup_subtree(name, root_clk);
320 static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
323 if (!core || index >= core->num_parents)
326 if (!core->parents[index])
327 core->parents[index] =
328 clk_core_lookup(core->parent_names[index]);
330 return core->parents[index];
334 clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
336 struct clk_core *parent;
338 parent = clk_core_get_parent_by_index(hw->core, index);
340 return !parent ? NULL : parent->hw;
342 EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
344 unsigned int __clk_get_enable_count(struct clk *clk)
346 return !clk ? 0 : clk->core->enable_count;
349 static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
360 if (!core->num_parents)
370 unsigned long clk_hw_get_rate(const struct clk_hw *hw)
372 return clk_core_get_rate_nolock(hw->core);
374 EXPORT_SYMBOL_GPL(clk_hw_get_rate);
376 static unsigned long __clk_get_accuracy(struct clk_core *core)
381 return core->accuracy;
384 unsigned long __clk_get_flags(struct clk *clk)
386 return !clk ? 0 : clk->core->flags;
388 EXPORT_SYMBOL_GPL(__clk_get_flags);
390 unsigned long clk_hw_get_flags(const struct clk_hw *hw)
392 return hw->core->flags;
394 EXPORT_SYMBOL_GPL(clk_hw_get_flags);
396 bool clk_hw_is_prepared(const struct clk_hw *hw)
398 return clk_core_is_prepared(hw->core);
401 bool clk_hw_rate_is_protected(const struct clk_hw *hw)
403 return clk_core_rate_is_protected(hw->core);
406 bool clk_hw_is_enabled(const struct clk_hw *hw)
408 return clk_core_is_enabled(hw->core);
411 bool __clk_is_enabled(struct clk *clk)
416 return clk_core_is_enabled(clk->core);
418 EXPORT_SYMBOL_GPL(__clk_is_enabled);
420 static bool mux_is_better_rate(unsigned long rate, unsigned long now,
421 unsigned long best, unsigned long flags)
423 if (flags & CLK_MUX_ROUND_CLOSEST)
424 return abs(now - rate) < abs(best - rate);
426 return now <= rate && now > best;
429 int clk_mux_determine_rate_flags(struct clk_hw *hw,
430 struct clk_rate_request *req,
433 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
434 int i, num_parents, ret;
435 unsigned long best = 0;
436 struct clk_rate_request parent_req = *req;
438 /* if NO_REPARENT flag set, pass through to current parent */
439 if (core->flags & CLK_SET_RATE_NO_REPARENT) {
440 parent = core->parent;
441 if (core->flags & CLK_SET_RATE_PARENT) {
442 ret = __clk_determine_rate(parent ? parent->hw : NULL,
447 best = parent_req.rate;
449 best = clk_core_get_rate_nolock(parent);
451 best = clk_core_get_rate_nolock(core);
457 /* find the parent that can provide the fastest rate <= rate */
458 num_parents = core->num_parents;
459 for (i = 0; i < num_parents; i++) {
460 parent = clk_core_get_parent_by_index(core, i);
464 if (core->flags & CLK_SET_RATE_PARENT) {
466 ret = __clk_determine_rate(parent->hw, &parent_req);
470 parent_req.rate = clk_core_get_rate_nolock(parent);
473 if (mux_is_better_rate(req->rate, parent_req.rate,
475 best_parent = parent;
476 best = parent_req.rate;
485 req->best_parent_hw = best_parent->hw;
486 req->best_parent_rate = best;
491 EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);
493 struct clk *__clk_lookup(const char *name)
495 struct clk_core *core = clk_core_lookup(name);
497 return !core ? NULL : core->hw->clk;
500 static void clk_core_get_boundaries(struct clk_core *core,
501 unsigned long *min_rate,
502 unsigned long *max_rate)
504 struct clk *clk_user;
506 *min_rate = core->min_rate;
507 *max_rate = core->max_rate;
509 hlist_for_each_entry(clk_user, &core->clks, clks_node)
510 *min_rate = max(*min_rate, clk_user->min_rate);
512 hlist_for_each_entry(clk_user, &core->clks, clks_node)
513 *max_rate = min(*max_rate, clk_user->max_rate);
516 void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
517 unsigned long max_rate)
519 hw->core->min_rate = min_rate;
520 hw->core->max_rate = max_rate;
522 EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
525 * Helper for finding best parent to provide a given frequency. This can be used
526 * directly as a determine_rate callback (e.g. for a mux), or from a more
527 * complex clock that may combine a mux with other operations.
529 int __clk_mux_determine_rate(struct clk_hw *hw,
530 struct clk_rate_request *req)
532 return clk_mux_determine_rate_flags(hw, req, 0);
534 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
536 int __clk_mux_determine_rate_closest(struct clk_hw *hw,
537 struct clk_rate_request *req)
539 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
541 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
545 static void clk_core_rate_unprotect(struct clk_core *core)
547 lockdep_assert_held(&prepare_lock);
552 if (WARN(core->protect_count == 0,
553 "%s already unprotected\n", core->name))
556 if (--core->protect_count > 0)
559 clk_core_rate_unprotect(core->parent);
562 static int clk_core_rate_nuke_protect(struct clk_core *core)
566 lockdep_assert_held(&prepare_lock);
571 if (core->protect_count == 0)
574 ret = core->protect_count;
575 core->protect_count = 1;
576 clk_core_rate_unprotect(core);
582 * clk_rate_exclusive_put - release exclusivity over clock rate control
583 * @clk: the clk over which the exclusivity is released
585 * clk_rate_exclusive_put() completes a critical section during which a clock
586 * consumer cannot tolerate any other consumer making any operation on the
587 * clock which could result in a rate change or rate glitch. Exclusive clocks
588 * cannot have their rate changed, either directly or indirectly due to changes
589 * further up the parent chain of clocks. As a result, clocks up parent chain
590 * also get under exclusive control of the calling consumer.
592 * If exlusivity is claimed more than once on clock, even by the same consumer,
593 * the rate effectively gets locked as exclusivity can't be preempted.
595 * Calls to clk_rate_exclusive_put() must be balanced with calls to
596 * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
599 void clk_rate_exclusive_put(struct clk *clk)
607 * if there is something wrong with this consumer protect count, stop
608 * here before messing with the provider
610 if (WARN_ON(clk->exclusive_count <= 0))
613 clk_core_rate_unprotect(clk->core);
614 clk->exclusive_count--;
616 clk_prepare_unlock();
618 EXPORT_SYMBOL_GPL(clk_rate_exclusive_put);
620 static void clk_core_rate_protect(struct clk_core *core)
622 lockdep_assert_held(&prepare_lock);
627 if (core->protect_count == 0)
628 clk_core_rate_protect(core->parent);
630 core->protect_count++;
633 static void clk_core_rate_restore_protect(struct clk_core *core, int count)
635 lockdep_assert_held(&prepare_lock);
643 clk_core_rate_protect(core);
644 core->protect_count = count;
648 * clk_rate_exclusive_get - get exclusivity over the clk rate control
649 * @clk: the clk over which the exclusity of rate control is requested
651 * clk_rate_exlusive_get() begins a critical section during which a clock
652 * consumer cannot tolerate any other consumer making any operation on the
653 * clock which could result in a rate change or rate glitch. Exclusive clocks
654 * cannot have their rate changed, either directly or indirectly due to changes
655 * further up the parent chain of clocks. As a result, clocks up parent chain
656 * also get under exclusive control of the calling consumer.
658 * If exlusivity is claimed more than once on clock, even by the same consumer,
659 * the rate effectively gets locked as exclusivity can't be preempted.
661 * Calls to clk_rate_exclusive_get() should be balanced with calls to
662 * clk_rate_exclusive_put(). Calls to this function may sleep.
663 * Returns 0 on success, -EERROR otherwise
665 int clk_rate_exclusive_get(struct clk *clk)
671 clk_core_rate_protect(clk->core);
672 clk->exclusive_count++;
673 clk_prepare_unlock();
677 EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
679 static void clk_core_unprepare(struct clk_core *core)
681 lockdep_assert_held(&prepare_lock);
686 if (WARN(core->prepare_count == 0,
687 "%s already unprepared\n", core->name))
690 if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL,
691 "Unpreparing critical %s\n", core->name))
694 if (--core->prepare_count > 0)
697 WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);
699 trace_clk_unprepare(core);
701 if (core->ops->unprepare)
702 core->ops->unprepare(core->hw);
704 clk_pm_runtime_put(core);
706 trace_clk_unprepare_complete(core);
707 clk_core_unprepare(core->parent);
710 static void clk_core_unprepare_lock(struct clk_core *core)
713 clk_core_unprepare(core);
714 clk_prepare_unlock();
718 * clk_unprepare - undo preparation of a clock source
719 * @clk: the clk being unprepared
721 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
722 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
723 * if the operation may sleep. One example is a clk which is accessed over
724 * I2c. In the complex case a clk gate operation may require a fast and a slow
725 * part. It is this reason that clk_unprepare and clk_disable are not mutually
726 * exclusive. In fact clk_disable must be called before clk_unprepare.
728 void clk_unprepare(struct clk *clk)
730 if (IS_ERR_OR_NULL(clk))
733 clk_core_unprepare_lock(clk->core);
735 EXPORT_SYMBOL_GPL(clk_unprepare);
737 static int clk_core_prepare(struct clk_core *core)
741 lockdep_assert_held(&prepare_lock);
746 if (core->prepare_count == 0) {
747 ret = clk_pm_runtime_get(core);
751 ret = clk_core_prepare(core->parent);
755 trace_clk_prepare(core);
757 if (core->ops->prepare)
758 ret = core->ops->prepare(core->hw);
760 trace_clk_prepare_complete(core);
766 core->prepare_count++;
770 clk_core_unprepare(core->parent);
772 clk_pm_runtime_put(core);
776 static int clk_core_prepare_lock(struct clk_core *core)
781 ret = clk_core_prepare(core);
782 clk_prepare_unlock();
788 * clk_prepare - prepare a clock source
789 * @clk: the clk being prepared
791 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
792 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
793 * operation may sleep. One example is a clk which is accessed over I2c. In
794 * the complex case a clk ungate operation may require a fast and a slow part.
795 * It is this reason that clk_prepare and clk_enable are not mutually
796 * exclusive. In fact clk_prepare must be called before clk_enable.
797 * Returns 0 on success, -EERROR otherwise.
799 int clk_prepare(struct clk *clk)
804 return clk_core_prepare_lock(clk->core);
806 EXPORT_SYMBOL_GPL(clk_prepare);
808 static void clk_core_disable(struct clk_core *core)
810 lockdep_assert_held(&enable_lock);
815 if (WARN(core->enable_count == 0, "%s already disabled\n", core->name))
818 if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL,
819 "Disabling critical %s\n", core->name))
822 if (--core->enable_count > 0)
825 trace_clk_disable_rcuidle(core);
827 if (core->ops->disable)
828 core->ops->disable(core->hw);
830 trace_clk_disable_complete_rcuidle(core);
832 clk_core_disable(core->parent);
835 static void clk_core_disable_lock(struct clk_core *core)
839 flags = clk_enable_lock();
840 clk_core_disable(core);
841 clk_enable_unlock(flags);
845 * clk_disable - gate a clock
846 * @clk: the clk being gated
848 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
849 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
850 * clk if the operation is fast and will never sleep. One example is a
851 * SoC-internal clk which is controlled via simple register writes. In the
852 * complex case a clk gate operation may require a fast and a slow part. It is
853 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
854 * In fact clk_disable must be called before clk_unprepare.
856 void clk_disable(struct clk *clk)
858 if (IS_ERR_OR_NULL(clk))
861 clk_core_disable_lock(clk->core);
863 EXPORT_SYMBOL_GPL(clk_disable);
865 static int clk_core_enable(struct clk_core *core)
869 lockdep_assert_held(&enable_lock);
874 if (WARN(core->prepare_count == 0,
875 "Enabling unprepared %s\n", core->name))
878 if (core->enable_count == 0) {
879 ret = clk_core_enable(core->parent);
884 trace_clk_enable_rcuidle(core);
886 if (core->ops->enable)
887 ret = core->ops->enable(core->hw);
889 trace_clk_enable_complete_rcuidle(core);
892 clk_core_disable(core->parent);
897 core->enable_count++;
901 static int clk_core_enable_lock(struct clk_core *core)
906 flags = clk_enable_lock();
907 ret = clk_core_enable(core);
908 clk_enable_unlock(flags);
914 * clk_enable - ungate a clock
915 * @clk: the clk being ungated
917 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
918 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
919 * if the operation will never sleep. One example is a SoC-internal clk which
920 * is controlled via simple register writes. In the complex case a clk ungate
921 * operation may require a fast and a slow part. It is this reason that
922 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
923 * must be called before clk_enable. Returns 0 on success, -EERROR
926 int clk_enable(struct clk *clk)
931 return clk_core_enable_lock(clk->core);
933 EXPORT_SYMBOL_GPL(clk_enable);
935 static int clk_core_prepare_enable(struct clk_core *core)
939 ret = clk_core_prepare_lock(core);
943 ret = clk_core_enable_lock(core);
945 clk_core_unprepare_lock(core);
950 static void clk_core_disable_unprepare(struct clk_core *core)
952 clk_core_disable_lock(core);
953 clk_core_unprepare_lock(core);
956 static void clk_unprepare_unused_subtree(struct clk_core *core)
958 struct clk_core *child;
960 lockdep_assert_held(&prepare_lock);
962 hlist_for_each_entry(child, &core->children, child_node)
963 clk_unprepare_unused_subtree(child);
965 if (core->prepare_count)
968 if (core->flags & CLK_IGNORE_UNUSED)
971 if (clk_pm_runtime_get(core))
974 if (clk_core_is_prepared(core)) {
975 trace_clk_unprepare(core);
976 if (core->ops->unprepare_unused)
977 core->ops->unprepare_unused(core->hw);
978 else if (core->ops->unprepare)
979 core->ops->unprepare(core->hw);
980 trace_clk_unprepare_complete(core);
983 clk_pm_runtime_put(core);
986 static void clk_disable_unused_subtree(struct clk_core *core)
988 struct clk_core *child;
991 lockdep_assert_held(&prepare_lock);
993 hlist_for_each_entry(child, &core->children, child_node)
994 clk_disable_unused_subtree(child);
996 if (core->flags & CLK_OPS_PARENT_ENABLE)
997 clk_core_prepare_enable(core->parent);
999 if (clk_pm_runtime_get(core))
1002 flags = clk_enable_lock();
1004 if (core->enable_count)
1007 if (core->flags & CLK_IGNORE_UNUSED)
1011 * some gate clocks have special needs during the disable-unused
1012 * sequence. call .disable_unused if available, otherwise fall
1015 if (clk_core_is_enabled(core)) {
1016 trace_clk_disable(core);
1017 if (core->ops->disable_unused)
1018 core->ops->disable_unused(core->hw);
1019 else if (core->ops->disable)
1020 core->ops->disable(core->hw);
1021 trace_clk_disable_complete(core);
1025 clk_enable_unlock(flags);
1026 clk_pm_runtime_put(core);
1028 if (core->flags & CLK_OPS_PARENT_ENABLE)
1029 clk_core_disable_unprepare(core->parent);
1032 static bool clk_ignore_unused;
1033 static int __init clk_ignore_unused_setup(char *__unused)
1035 clk_ignore_unused = true;
1038 __setup("clk_ignore_unused", clk_ignore_unused_setup);
1040 static int clk_disable_unused(void)
1042 struct clk_core *core;
1044 if (clk_ignore_unused) {
1045 pr_warn("clk: Not disabling unused clocks\n");
1051 hlist_for_each_entry(core, &clk_root_list, child_node)
1052 clk_disable_unused_subtree(core);
1054 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1055 clk_disable_unused_subtree(core);
1057 hlist_for_each_entry(core, &clk_root_list, child_node)
1058 clk_unprepare_unused_subtree(core);
1060 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1061 clk_unprepare_unused_subtree(core);
1063 clk_prepare_unlock();
1067 late_initcall_sync(clk_disable_unused);
1069 static int clk_core_determine_round_nolock(struct clk_core *core,
1070 struct clk_rate_request *req)
1074 lockdep_assert_held(&prepare_lock);
1080 * At this point, core protection will be disabled if
1081 * - if the provider is not protected at all
1082 * - if the calling consumer is the only one which has exclusivity
1085 if (clk_core_rate_is_protected(core)) {
1086 req->rate = core->rate;
1087 } else if (core->ops->determine_rate) {
1088 return core->ops->determine_rate(core->hw, req);
1089 } else if (core->ops->round_rate) {
1090 rate = core->ops->round_rate(core->hw, req->rate,
1091 &req->best_parent_rate);
1103 static void clk_core_init_rate_req(struct clk_core * const core,
1104 struct clk_rate_request *req)
1106 struct clk_core *parent;
1108 if (WARN_ON(!core || !req))
1111 parent = core->parent;
1113 req->best_parent_hw = parent->hw;
1114 req->best_parent_rate = parent->rate;
1116 req->best_parent_hw = NULL;
1117 req->best_parent_rate = 0;
1121 static bool clk_core_can_round(struct clk_core * const core)
1123 if (core->ops->determine_rate || core->ops->round_rate)
1129 static int clk_core_round_rate_nolock(struct clk_core *core,
1130 struct clk_rate_request *req)
1132 lockdep_assert_held(&prepare_lock);
1139 clk_core_init_rate_req(core, req);
1141 if (clk_core_can_round(core))
1142 return clk_core_determine_round_nolock(core, req);
1143 else if (core->flags & CLK_SET_RATE_PARENT)
1144 return clk_core_round_rate_nolock(core->parent, req);
1146 req->rate = core->rate;
1151 * __clk_determine_rate - get the closest rate actually supported by a clock
1152 * @hw: determine the rate of this clock
1153 * @req: target rate request
1155 * Useful for clk_ops such as .set_rate and .determine_rate.
1157 int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
1164 return clk_core_round_rate_nolock(hw->core, req);
1166 EXPORT_SYMBOL_GPL(__clk_determine_rate);
1168 unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
1171 struct clk_rate_request req;
1173 clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate);
1176 ret = clk_core_round_rate_nolock(hw->core, &req);
1182 EXPORT_SYMBOL_GPL(clk_hw_round_rate);
1185 * clk_round_rate - round the given rate for a clk
1186 * @clk: the clk for which we are rounding a rate
1187 * @rate: the rate which is to be rounded
1189 * Takes in a rate as input and rounds it to a rate that the clk can actually
1190 * use which is then returned. If clk doesn't support round_rate operation
1191 * then the parent rate is returned.
1193 long clk_round_rate(struct clk *clk, unsigned long rate)
1195 struct clk_rate_request req;
1203 if (clk->exclusive_count)
1204 clk_core_rate_unprotect(clk->core);
1206 clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
1209 ret = clk_core_round_rate_nolock(clk->core, &req);
1211 if (clk->exclusive_count)
1212 clk_core_rate_protect(clk->core);
1214 clk_prepare_unlock();
1221 EXPORT_SYMBOL_GPL(clk_round_rate);
1224 * __clk_notify - call clk notifier chain
1225 * @core: clk that is changing rate
1226 * @msg: clk notifier type (see include/linux/clk.h)
1227 * @old_rate: old clk rate
1228 * @new_rate: new clk rate
1230 * Triggers a notifier call chain on the clk rate-change notification
1231 * for 'clk'. Passes a pointer to the struct clk and the previous
1232 * and current rates to the notifier callback. Intended to be called by
1233 * internal clock code only. Returns NOTIFY_DONE from the last driver
1234 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1235 * a driver returns that.
1237 static int __clk_notify(struct clk_core *core, unsigned long msg,
1238 unsigned long old_rate, unsigned long new_rate)
1240 struct clk_notifier *cn;
1241 struct clk_notifier_data cnd;
1242 int ret = NOTIFY_DONE;
1244 cnd.old_rate = old_rate;
1245 cnd.new_rate = new_rate;
1247 list_for_each_entry(cn, &clk_notifier_list, node) {
1248 if (cn->clk->core == core) {
1250 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
1252 if (ret & NOTIFY_STOP_MASK)
1261 * __clk_recalc_accuracies
1262 * @core: first clk in the subtree
1264 * Walks the subtree of clks starting with clk and recalculates accuracies as
1265 * it goes. Note that if a clk does not implement the .recalc_accuracy
1266 * callback then it is assumed that the clock will take on the accuracy of its
1269 static void __clk_recalc_accuracies(struct clk_core *core)
1271 unsigned long parent_accuracy = 0;
1272 struct clk_core *child;
1274 lockdep_assert_held(&prepare_lock);
1277 parent_accuracy = core->parent->accuracy;
1279 if (core->ops->recalc_accuracy)
1280 core->accuracy = core->ops->recalc_accuracy(core->hw,
1283 core->accuracy = parent_accuracy;
1285 hlist_for_each_entry(child, &core->children, child_node)
1286 __clk_recalc_accuracies(child);
1289 static long clk_core_get_accuracy(struct clk_core *core)
1291 unsigned long accuracy;
1294 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
1295 __clk_recalc_accuracies(core);
1297 accuracy = __clk_get_accuracy(core);
1298 clk_prepare_unlock();
1304 * clk_get_accuracy - return the accuracy of clk
1305 * @clk: the clk whose accuracy is being returned
1307 * Simply returns the cached accuracy of the clk, unless
1308 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1310 * If clk is NULL then returns 0.
1312 long clk_get_accuracy(struct clk *clk)
1317 return clk_core_get_accuracy(clk->core);
1319 EXPORT_SYMBOL_GPL(clk_get_accuracy);
1321 static unsigned long clk_recalc(struct clk_core *core,
1322 unsigned long parent_rate)
1324 unsigned long rate = parent_rate;
1326 if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
1327 rate = core->ops->recalc_rate(core->hw, parent_rate);
1328 clk_pm_runtime_put(core);
1334 * __clk_recalc_rates
1335 * @core: first clk in the subtree
1336 * @msg: notification type (see include/linux/clk.h)
1338 * Walks the subtree of clks starting with clk and recalculates rates as it
1339 * goes. Note that if a clk does not implement the .recalc_rate callback then
1340 * it is assumed that the clock will take on the rate of its parent.
1342 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1345 static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
1347 unsigned long old_rate;
1348 unsigned long parent_rate = 0;
1349 struct clk_core *child;
1351 lockdep_assert_held(&prepare_lock);
1353 old_rate = core->rate;
1356 parent_rate = core->parent->rate;
1358 core->rate = clk_recalc(core, parent_rate);
1361 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1362 * & ABORT_RATE_CHANGE notifiers
1364 if (core->notifier_count && msg)
1365 __clk_notify(core, msg, old_rate, core->rate);
1367 hlist_for_each_entry(child, &core->children, child_node)
1368 __clk_recalc_rates(child, msg);
1371 static unsigned long clk_core_get_rate(struct clk_core *core)
1377 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1378 __clk_recalc_rates(core, 0);
1380 rate = clk_core_get_rate_nolock(core);
1381 clk_prepare_unlock();
1387 * clk_get_rate - return the rate of clk
1388 * @clk: the clk whose rate is being returned
1390 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1391 * is set, which means a recalc_rate will be issued.
1392 * If clk is NULL then returns 0.
1394 unsigned long clk_get_rate(struct clk *clk)
1399 return clk_core_get_rate(clk->core);
1401 EXPORT_SYMBOL_GPL(clk_get_rate);
1403 static int clk_fetch_parent_index(struct clk_core *core,
1404 struct clk_core *parent)
1411 for (i = 0; i < core->num_parents; i++)
1412 if (clk_core_get_parent_by_index(core, i) == parent)
1419 * Update the orphan status of @core and all its children.
1421 static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
1423 struct clk_core *child;
1425 core->orphan = is_orphan;
1427 hlist_for_each_entry(child, &core->children, child_node)
1428 clk_core_update_orphan_status(child, is_orphan);
1431 static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1433 bool was_orphan = core->orphan;
1435 hlist_del(&core->child_node);
1438 bool becomes_orphan = new_parent->orphan;
1440 /* avoid duplicate POST_RATE_CHANGE notifications */
1441 if (new_parent->new_child == core)
1442 new_parent->new_child = NULL;
1444 hlist_add_head(&core->child_node, &new_parent->children);
1446 if (was_orphan != becomes_orphan)
1447 clk_core_update_orphan_status(core, becomes_orphan);
1449 hlist_add_head(&core->child_node, &clk_orphan_list);
1451 clk_core_update_orphan_status(core, true);
1454 core->parent = new_parent;
1457 static struct clk_core *__clk_set_parent_before(struct clk_core *core,
1458 struct clk_core *parent)
1460 unsigned long flags;
1461 struct clk_core *old_parent = core->parent;
1464 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
1466 * 2. Migrate prepare state between parents and prevent race with
1469 * If the clock is not prepared, then a race with
1470 * clk_enable/disable() is impossible since we already have the
1471 * prepare lock (future calls to clk_enable() need to be preceded by
1474 * If the clock is prepared, migrate the prepared state to the new
1475 * parent and also protect against a race with clk_enable() by
1476 * forcing the clock and the new parent on. This ensures that all
1477 * future calls to clk_enable() are practically NOPs with respect to
1478 * hardware and software states.
1480 * See also: Comment for clk_set_parent() below.
1483 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
1484 if (core->flags & CLK_OPS_PARENT_ENABLE) {
1485 clk_core_prepare_enable(old_parent);
1486 clk_core_prepare_enable(parent);
1489 /* migrate prepare count if > 0 */
1490 if (core->prepare_count) {
1491 clk_core_prepare_enable(parent);
1492 clk_core_enable_lock(core);
1495 /* update the clk tree topology */
1496 flags = clk_enable_lock();
1497 clk_reparent(core, parent);
1498 clk_enable_unlock(flags);
1503 static void __clk_set_parent_after(struct clk_core *core,
1504 struct clk_core *parent,
1505 struct clk_core *old_parent)
1508 * Finish the migration of prepare state and undo the changes done
1509 * for preventing a race with clk_enable().
1511 if (core->prepare_count) {
1512 clk_core_disable_lock(core);
1513 clk_core_disable_unprepare(old_parent);
1516 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
1517 if (core->flags & CLK_OPS_PARENT_ENABLE) {
1518 clk_core_disable_unprepare(parent);
1519 clk_core_disable_unprepare(old_parent);
1523 static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
1526 unsigned long flags;
1528 struct clk_core *old_parent;
1530 old_parent = __clk_set_parent_before(core, parent);
1532 trace_clk_set_parent(core, parent);
1534 /* change clock input source */
1535 if (parent && core->ops->set_parent)
1536 ret = core->ops->set_parent(core->hw, p_index);
1538 trace_clk_set_parent_complete(core, parent);
1541 flags = clk_enable_lock();
1542 clk_reparent(core, old_parent);
1543 clk_enable_unlock(flags);
1544 __clk_set_parent_after(core, old_parent, parent);
1549 __clk_set_parent_after(core, parent, old_parent);
1555 * __clk_speculate_rates
1556 * @core: first clk in the subtree
1557 * @parent_rate: the "future" rate of clk's parent
1559 * Walks the subtree of clks starting with clk, speculating rates as it
1560 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1562 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1563 * pre-rate change notifications and returns early if no clks in the
1564 * subtree have subscribed to the notifications. Note that if a clk does not
1565 * implement the .recalc_rate callback then it is assumed that the clock will
1566 * take on the rate of its parent.
1568 static int __clk_speculate_rates(struct clk_core *core,
1569 unsigned long parent_rate)
1571 struct clk_core *child;
1572 unsigned long new_rate;
1573 int ret = NOTIFY_DONE;
1575 lockdep_assert_held(&prepare_lock);
1577 new_rate = clk_recalc(core, parent_rate);
1579 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1580 if (core->notifier_count)
1581 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
1583 if (ret & NOTIFY_STOP_MASK) {
1584 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1585 __func__, core->name, ret);
1589 hlist_for_each_entry(child, &core->children, child_node) {
1590 ret = __clk_speculate_rates(child, new_rate);
1591 if (ret & NOTIFY_STOP_MASK)
1599 static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
1600 struct clk_core *new_parent, u8 p_index)
1602 struct clk_core *child;
1604 core->new_rate = new_rate;
1605 core->new_parent = new_parent;
1606 core->new_parent_index = p_index;
1607 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1608 core->new_child = NULL;
1609 if (new_parent && new_parent != core->parent)
1610 new_parent->new_child = core;
1612 hlist_for_each_entry(child, &core->children, child_node) {
1613 child->new_rate = clk_recalc(child, new_rate);
1614 clk_calc_subtree(child, child->new_rate, NULL, 0);
1619 * calculate the new rates returning the topmost clock that has to be
1622 static struct clk_core *clk_calc_new_rates(struct clk_core *core,
1625 struct clk_core *top = core;
1626 struct clk_core *old_parent, *parent;
1627 unsigned long best_parent_rate = 0;
1628 unsigned long new_rate;
1629 unsigned long min_rate;
1630 unsigned long max_rate;
1635 if (IS_ERR_OR_NULL(core))
1638 /* save parent rate, if it exists */
1639 parent = old_parent = core->parent;
1641 best_parent_rate = parent->rate;
1643 clk_core_get_boundaries(core, &min_rate, &max_rate);
1645 /* find the closest rate and parent clk/rate */
1646 if (clk_core_can_round(core)) {
1647 struct clk_rate_request req;
1650 req.min_rate = min_rate;
1651 req.max_rate = max_rate;
1653 clk_core_init_rate_req(core, &req);
1655 ret = clk_core_determine_round_nolock(core, &req);
1659 best_parent_rate = req.best_parent_rate;
1660 new_rate = req.rate;
1661 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
1663 if (new_rate < min_rate || new_rate > max_rate)
1665 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
1666 /* pass-through clock without adjustable parent */
1667 core->new_rate = core->rate;
1670 /* pass-through clock with adjustable parent */
1671 top = clk_calc_new_rates(parent, rate);
1672 new_rate = parent->new_rate;
1676 /* some clocks must be gated to change parent */
1677 if (parent != old_parent &&
1678 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1679 pr_debug("%s: %s not gated but wants to reparent\n",
1680 __func__, core->name);
1684 /* try finding the new parent index */
1685 if (parent && core->num_parents > 1) {
1686 p_index = clk_fetch_parent_index(core, parent);
1688 pr_debug("%s: clk %s can not be parent of clk %s\n",
1689 __func__, parent->name, core->name);
1694 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
1695 best_parent_rate != parent->rate)
1696 top = clk_calc_new_rates(parent, best_parent_rate);
1699 clk_calc_subtree(core, new_rate, parent, p_index);
1705 * Notify about rate changes in a subtree. Always walk down the whole tree
1706 * so that in case of an error we can walk down the whole tree again and
1709 static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
1710 unsigned long event)
1712 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
1713 int ret = NOTIFY_DONE;
1715 if (core->rate == core->new_rate)
1718 if (core->notifier_count) {
1719 ret = __clk_notify(core, event, core->rate, core->new_rate);
1720 if (ret & NOTIFY_STOP_MASK)
1724 hlist_for_each_entry(child, &core->children, child_node) {
1725 /* Skip children who will be reparented to another clock */
1726 if (child->new_parent && child->new_parent != core)
1728 tmp_clk = clk_propagate_rate_change(child, event);
1733 /* handle the new child who might not be in core->children yet */
1734 if (core->new_child) {
1735 tmp_clk = clk_propagate_rate_change(core->new_child, event);
1744 * walk down a subtree and set the new rates notifying the rate
1747 static void clk_change_rate(struct clk_core *core)
1749 struct clk_core *child;
1750 struct hlist_node *tmp;
1751 unsigned long old_rate;
1752 unsigned long best_parent_rate = 0;
1753 bool skip_set_rate = false;
1754 struct clk_core *old_parent;
1755 struct clk_core *parent = NULL;
1757 old_rate = core->rate;
1759 if (core->new_parent) {
1760 parent = core->new_parent;
1761 best_parent_rate = core->new_parent->rate;
1762 } else if (core->parent) {
1763 parent = core->parent;
1764 best_parent_rate = core->parent->rate;
1767 if (clk_pm_runtime_get(core))
1770 if (core->flags & CLK_SET_RATE_UNGATE) {
1771 unsigned long flags;
1773 clk_core_prepare(core);
1774 flags = clk_enable_lock();
1775 clk_core_enable(core);
1776 clk_enable_unlock(flags);
1779 if (core->new_parent && core->new_parent != core->parent) {
1780 old_parent = __clk_set_parent_before(core, core->new_parent);
1781 trace_clk_set_parent(core, core->new_parent);
1783 if (core->ops->set_rate_and_parent) {
1784 skip_set_rate = true;
1785 core->ops->set_rate_and_parent(core->hw, core->new_rate,
1787 core->new_parent_index);
1788 } else if (core->ops->set_parent) {
1789 core->ops->set_parent(core->hw, core->new_parent_index);
1792 trace_clk_set_parent_complete(core, core->new_parent);
1793 __clk_set_parent_after(core, core->new_parent, old_parent);
1796 if (core->flags & CLK_OPS_PARENT_ENABLE)
1797 clk_core_prepare_enable(parent);
1799 trace_clk_set_rate(core, core->new_rate);
1801 if (!skip_set_rate && core->ops->set_rate)
1802 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
1804 trace_clk_set_rate_complete(core, core->new_rate);
1806 core->rate = clk_recalc(core, best_parent_rate);
1808 if (core->flags & CLK_SET_RATE_UNGATE) {
1809 unsigned long flags;
1811 flags = clk_enable_lock();
1812 clk_core_disable(core);
1813 clk_enable_unlock(flags);
1814 clk_core_unprepare(core);
1817 if (core->flags & CLK_OPS_PARENT_ENABLE)
1818 clk_core_disable_unprepare(parent);
1820 if (core->notifier_count && old_rate != core->rate)
1821 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
1823 if (core->flags & CLK_RECALC_NEW_RATES)
1824 (void)clk_calc_new_rates(core, core->new_rate);
1827 * Use safe iteration, as change_rate can actually swap parents
1828 * for certain clock types.
1830 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
1831 /* Skip children who will be reparented to another clock */
1832 if (child->new_parent && child->new_parent != core)
1834 clk_change_rate(child);
1837 /* handle the new child who might not be in core->children yet */
1838 if (core->new_child)
1839 clk_change_rate(core->new_child);
1841 clk_pm_runtime_put(core);
1844 static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
1845 unsigned long req_rate)
1848 struct clk_rate_request req;
1850 lockdep_assert_held(&prepare_lock);
1855 /* simulate what the rate would be if it could be freely set */
1856 cnt = clk_core_rate_nuke_protect(core);
1860 clk_core_get_boundaries(core, &req.min_rate, &req.max_rate);
1861 req.rate = req_rate;
1863 ret = clk_core_round_rate_nolock(core, &req);
1865 /* restore the protection */
1866 clk_core_rate_restore_protect(core, cnt);
1868 return ret ? 0 : req.rate;
1871 static int clk_core_set_rate_nolock(struct clk_core *core,
1872 unsigned long req_rate)
1874 struct clk_core *top, *fail_clk;
1881 rate = clk_core_req_round_rate_nolock(core, req_rate);
1883 /* bail early if nothing to do */
1884 if (rate == clk_core_get_rate_nolock(core))
1887 /* fail on a direct rate set of a protected provider */
1888 if (clk_core_rate_is_protected(core))
1891 if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count)
1894 /* calculate new rates and get the topmost changed clock */
1895 top = clk_calc_new_rates(core, req_rate);
1899 ret = clk_pm_runtime_get(core);
1903 /* notify that we are about to change rates */
1904 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
1906 pr_debug("%s: failed to set %s rate\n", __func__,
1908 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
1913 /* change the rates */
1914 clk_change_rate(top);
1916 core->req_rate = req_rate;
1918 clk_pm_runtime_put(core);
1924 * clk_set_rate - specify a new rate for clk
1925 * @clk: the clk whose rate is being changed
1926 * @rate: the new rate for clk
1928 * In the simplest case clk_set_rate will only adjust the rate of clk.
1930 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1931 * propagate up to clk's parent; whether or not this happens depends on the
1932 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1933 * after calling .round_rate then upstream parent propagation is ignored. If
1934 * *parent_rate comes back with a new rate for clk's parent then we propagate
1935 * up to clk's parent and set its rate. Upward propagation will continue
1936 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1937 * .round_rate stops requesting changes to clk's parent_rate.
1939 * Rate changes are accomplished via tree traversal that also recalculates the
1940 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
1942 * Returns 0 on success, -EERROR otherwise.
1944 int clk_set_rate(struct clk *clk, unsigned long rate)
1951 /* prevent racing with updates to the clock topology */
1954 if (clk->exclusive_count)
1955 clk_core_rate_unprotect(clk->core);
1957 ret = clk_core_set_rate_nolock(clk->core, rate);
1959 if (clk->exclusive_count)
1960 clk_core_rate_protect(clk->core);
1962 clk_prepare_unlock();
1966 EXPORT_SYMBOL_GPL(clk_set_rate);
1969 * clk_set_rate_exclusive - specify a new rate get exclusive control
1970 * @clk: the clk whose rate is being changed
1971 * @rate: the new rate for clk
1973 * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
1974 * within a critical section
1976 * This can be used initially to ensure that at least 1 consumer is
1977 * statisfied when several consumers are competing for exclusivity over the
1978 * same clock provider.
1980 * The exclusivity is not applied if setting the rate failed.
1982 * Calls to clk_rate_exclusive_get() should be balanced with calls to
1983 * clk_rate_exclusive_put().
1985 * Returns 0 on success, -EERROR otherwise.
1987 int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
1994 /* prevent racing with updates to the clock topology */
1998 * The temporary protection removal is not here, on purpose
1999 * This function is meant to be used instead of clk_rate_protect,
2000 * so before the consumer code path protect the clock provider
2003 ret = clk_core_set_rate_nolock(clk->core, rate);
2005 clk_core_rate_protect(clk->core);
2006 clk->exclusive_count++;
2009 clk_prepare_unlock();
2013 EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
2016 * clk_set_rate_range - set a rate range for a clock source
2017 * @clk: clock source
2018 * @min: desired minimum clock rate in Hz, inclusive
2019 * @max: desired maximum clock rate in Hz, inclusive
2021 * Returns success (0) or negative errno.
2023 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
2026 unsigned long old_min, old_max, rate;
2032 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
2033 __func__, clk->core->name, clk->dev_id, clk->con_id,
2040 if (clk->exclusive_count)
2041 clk_core_rate_unprotect(clk->core);
2043 /* Save the current values in case we need to rollback the change */
2044 old_min = clk->min_rate;
2045 old_max = clk->max_rate;
2046 clk->min_rate = min;
2047 clk->max_rate = max;
2049 rate = clk_core_get_rate_nolock(clk->core);
2050 if (rate < min || rate > max) {
2053 * We are in bit of trouble here, current rate is outside the
2054 * the requested range. We are going try to request appropriate
2055 * range boundary but there is a catch. It may fail for the
2056 * usual reason (clock broken, clock protected, etc) but also
2058 * - round_rate() was not favorable and fell on the wrong
2059 * side of the boundary
2060 * - the determine_rate() callback does not really check for
2061 * this corner case when determining the rate
2069 ret = clk_core_set_rate_nolock(clk->core, rate);
2071 /* rollback the changes */
2072 clk->min_rate = old_min;
2073 clk->max_rate = old_max;
2077 if (clk->exclusive_count)
2078 clk_core_rate_protect(clk->core);
2080 clk_prepare_unlock();
2084 EXPORT_SYMBOL_GPL(clk_set_rate_range);
2087 * clk_set_min_rate - set a minimum clock rate for a clock source
2088 * @clk: clock source
2089 * @rate: desired minimum clock rate in Hz, inclusive
2091 * Returns success (0) or negative errno.
2093 int clk_set_min_rate(struct clk *clk, unsigned long rate)
2098 return clk_set_rate_range(clk, rate, clk->max_rate);
2100 EXPORT_SYMBOL_GPL(clk_set_min_rate);
2103 * clk_set_max_rate - set a maximum clock rate for a clock source
2104 * @clk: clock source
2105 * @rate: desired maximum clock rate in Hz, inclusive
2107 * Returns success (0) or negative errno.
2109 int clk_set_max_rate(struct clk *clk, unsigned long rate)
2114 return clk_set_rate_range(clk, clk->min_rate, rate);
2116 EXPORT_SYMBOL_GPL(clk_set_max_rate);
2119 * clk_get_parent - return the parent of a clk
2120 * @clk: the clk whose parent gets returned
2122 * Simply returns clk->parent. Returns NULL if clk is NULL.
2124 struct clk *clk_get_parent(struct clk *clk)
2132 /* TODO: Create a per-user clk and change callers to call clk_put */
2133 parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
2134 clk_prepare_unlock();
2138 EXPORT_SYMBOL_GPL(clk_get_parent);
2140 static struct clk_core *__clk_init_parent(struct clk_core *core)
2144 if (core->num_parents > 1 && core->ops->get_parent)
2145 index = core->ops->get_parent(core->hw);
2147 return clk_core_get_parent_by_index(core, index);
2150 static void clk_core_reparent(struct clk_core *core,
2151 struct clk_core *new_parent)
2153 clk_reparent(core, new_parent);
2154 __clk_recalc_accuracies(core);
2155 __clk_recalc_rates(core, POST_RATE_CHANGE);
2158 void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
2163 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
2167 * clk_has_parent - check if a clock is a possible parent for another
2168 * @clk: clock source
2169 * @parent: parent clock source
2171 * This function can be used in drivers that need to check that a clock can be
2172 * the parent of another without actually changing the parent.
2174 * Returns true if @parent is a possible parent for @clk, false otherwise.
2176 bool clk_has_parent(struct clk *clk, struct clk *parent)
2178 struct clk_core *core, *parent_core;
2180 /* NULL clocks should be nops, so return success if either is NULL. */
2181 if (!clk || !parent)
2185 parent_core = parent->core;
2187 /* Optimize for the case where the parent is already the parent. */
2188 if (core->parent == parent_core)
2191 return match_string(core->parent_names, core->num_parents,
2192 parent_core->name) >= 0;
2194 EXPORT_SYMBOL_GPL(clk_has_parent);
2196 static int clk_core_set_parent_nolock(struct clk_core *core,
2197 struct clk_core *parent)
2201 unsigned long p_rate = 0;
2203 lockdep_assert_held(&prepare_lock);
2208 if (core->parent == parent)
2211 /* verify ops for for multi-parent clks */
2212 if (core->num_parents > 1 && !core->ops->set_parent)
2215 /* check that we are allowed to re-parent if the clock is in use */
2216 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
2219 if (clk_core_rate_is_protected(core))
2222 /* try finding the new parent index */
2224 p_index = clk_fetch_parent_index(core, parent);
2226 pr_debug("%s: clk %s can not be parent of clk %s\n",
2227 __func__, parent->name, core->name);
2230 p_rate = parent->rate;
2233 ret = clk_pm_runtime_get(core);
2237 /* propagate PRE_RATE_CHANGE notifications */
2238 ret = __clk_speculate_rates(core, p_rate);
2240 /* abort if a driver objects */
2241 if (ret & NOTIFY_STOP_MASK)
2244 /* do the re-parent */
2245 ret = __clk_set_parent(core, parent, p_index);
2247 /* propagate rate an accuracy recalculation accordingly */
2249 __clk_recalc_rates(core, ABORT_RATE_CHANGE);
2251 __clk_recalc_rates(core, POST_RATE_CHANGE);
2252 __clk_recalc_accuracies(core);
2256 clk_pm_runtime_put(core);
2262 * clk_set_parent - switch the parent of a mux clk
2263 * @clk: the mux clk whose input we are switching
2264 * @parent: the new input to clk
2266 * Re-parent clk to use parent as its new input source. If clk is in
2267 * prepared state, the clk will get enabled for the duration of this call. If
2268 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2269 * that, the reparenting is glitchy in hardware, etc), use the
2270 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2272 * After successfully changing clk's parent clk_set_parent will update the
2273 * clk topology, sysfs topology and propagate rate recalculation via
2274 * __clk_recalc_rates.
2276 * Returns 0 on success, -EERROR otherwise.
2278 int clk_set_parent(struct clk *clk, struct clk *parent)
2287 if (clk->exclusive_count)
2288 clk_core_rate_unprotect(clk->core);
2290 ret = clk_core_set_parent_nolock(clk->core,
2291 parent ? parent->core : NULL);
2293 if (clk->exclusive_count)
2294 clk_core_rate_protect(clk->core);
2296 clk_prepare_unlock();
2300 EXPORT_SYMBOL_GPL(clk_set_parent);
2302 static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
2306 lockdep_assert_held(&prepare_lock);
2311 if (clk_core_rate_is_protected(core))
2314 trace_clk_set_phase(core, degrees);
2316 if (core->ops->set_phase) {
2317 ret = core->ops->set_phase(core->hw, degrees);
2319 core->phase = degrees;
2322 trace_clk_set_phase_complete(core, degrees);
2328 * clk_set_phase - adjust the phase shift of a clock signal
2329 * @clk: clock signal source
2330 * @degrees: number of degrees the signal is shifted
2332 * Shifts the phase of a clock signal by the specified
2333 * degrees. Returns 0 on success, -EERROR otherwise.
2335 * This function makes no distinction about the input or reference
2336 * signal that we adjust the clock signal phase against. For example
2337 * phase locked-loop clock signal generators we may shift phase with
2338 * respect to feedback clock signal input, but for other cases the
2339 * clock phase may be shifted with respect to some other, unspecified
2342 * Additionally the concept of phase shift does not propagate through
2343 * the clock tree hierarchy, which sets it apart from clock rates and
2344 * clock accuracy. A parent clock phase attribute does not have an
2345 * impact on the phase attribute of a child clock.
2347 int clk_set_phase(struct clk *clk, int degrees)
2354 /* sanity check degrees */
2361 if (clk->exclusive_count)
2362 clk_core_rate_unprotect(clk->core);
2364 ret = clk_core_set_phase_nolock(clk->core, degrees);
2366 if (clk->exclusive_count)
2367 clk_core_rate_protect(clk->core);
2369 clk_prepare_unlock();
2373 EXPORT_SYMBOL_GPL(clk_set_phase);
2375 static int clk_core_get_phase(struct clk_core *core)
2380 /* Always try to update cached phase if possible */
2381 if (core->ops->get_phase)
2382 core->phase = core->ops->get_phase(core->hw);
2384 clk_prepare_unlock();
2390 * clk_get_phase - return the phase shift of a clock signal
2391 * @clk: clock signal source
2393 * Returns the phase shift of a clock node in degrees, otherwise returns
2396 int clk_get_phase(struct clk *clk)
2401 return clk_core_get_phase(clk->core);
2403 EXPORT_SYMBOL_GPL(clk_get_phase);
2405 static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
2407 /* Assume a default value of 50% */
2412 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);
2414 static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
2416 struct clk_duty *duty = &core->duty;
2419 if (!core->ops->get_duty_cycle)
2420 return clk_core_update_duty_cycle_parent_nolock(core);
2422 ret = core->ops->get_duty_cycle(core->hw, duty);
2426 /* Don't trust the clock provider too much */
2427 if (duty->den == 0 || duty->num > duty->den) {
2435 clk_core_reset_duty_cycle_nolock(core);
2439 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
2444 core->flags & CLK_DUTY_CYCLE_PARENT) {
2445 ret = clk_core_update_duty_cycle_nolock(core->parent);
2446 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
2448 clk_core_reset_duty_cycle_nolock(core);
2454 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
2455 struct clk_duty *duty);
2457 static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
2458 struct clk_duty *duty)
2462 lockdep_assert_held(&prepare_lock);
2464 if (clk_core_rate_is_protected(core))
2467 trace_clk_set_duty_cycle(core, duty);
2469 if (!core->ops->set_duty_cycle)
2470 return clk_core_set_duty_cycle_parent_nolock(core, duty);
2472 ret = core->ops->set_duty_cycle(core->hw, duty);
2474 memcpy(&core->duty, duty, sizeof(*duty));
2476 trace_clk_set_duty_cycle_complete(core, duty);
2481 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
2482 struct clk_duty *duty)
2487 core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
2488 ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
2489 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
2496 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
2497 * @clk: clock signal source
2498 * @num: numerator of the duty cycle ratio to be applied
2499 * @den: denominator of the duty cycle ratio to be applied
2501 * Apply the duty cycle ratio if the ratio is valid and the clock can
2502 * perform this operation
2504 * Returns (0) on success, a negative errno otherwise.
2506 int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
2509 struct clk_duty duty;
2514 /* sanity check the ratio */
2515 if (den == 0 || num > den)
2523 if (clk->exclusive_count)
2524 clk_core_rate_unprotect(clk->core);
2526 ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
2528 if (clk->exclusive_count)
2529 clk_core_rate_protect(clk->core);
2531 clk_prepare_unlock();
2535 EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
2537 static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
2540 struct clk_duty *duty = &core->duty;
2545 ret = clk_core_update_duty_cycle_nolock(core);
2547 ret = mult_frac(scale, duty->num, duty->den);
2549 clk_prepare_unlock();
2555 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
2556 * @clk: clock signal source
2557 * @scale: scaling factor to be applied to represent the ratio as an integer
2559 * Returns the duty cycle ratio of a clock node multiplied by the provided
2560 * scaling factor, or negative errno on error.
2562 int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
2567 return clk_core_get_scaled_duty_cycle(clk->core, scale);
2569 EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
2572 * clk_is_match - check if two clk's point to the same hardware clock
2573 * @p: clk compared against q
2574 * @q: clk compared against p
2576 * Returns true if the two struct clk pointers both point to the same hardware
2577 * clock node. Put differently, returns true if struct clk *p and struct clk *q
2578 * share the same struct clk_core object.
2580 * Returns false otherwise. Note that two NULL clks are treated as matching.
2582 bool clk_is_match(const struct clk *p, const struct clk *q)
2584 /* trivial case: identical struct clk's or both NULL */
2588 /* true if clk->core pointers match. Avoid dereferencing garbage */
2589 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
2590 if (p->core == q->core)
2595 EXPORT_SYMBOL_GPL(clk_is_match);
2597 /*** debugfs support ***/
2599 #ifdef CONFIG_DEBUG_FS
2600 #include <linux/debugfs.h>
2602 static struct dentry *rootdir;
2603 static int inited = 0;
2604 static DEFINE_MUTEX(clk_debug_lock);
2605 static HLIST_HEAD(clk_debug_list);
2607 static struct hlist_head *all_lists[] = {
2613 static struct hlist_head *orphan_list[] = {
2618 static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
2624 seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu %5d %6d\n",
2626 30 - level * 3, c->name,
2627 c->enable_count, c->prepare_count, c->protect_count,
2628 clk_core_get_rate(c), clk_core_get_accuracy(c),
2629 clk_core_get_phase(c),
2630 clk_core_get_scaled_duty_cycle(c, 100000));
2633 static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
2636 struct clk_core *child;
2641 clk_summary_show_one(s, c, level);
2643 hlist_for_each_entry(child, &c->children, child_node)
2644 clk_summary_show_subtree(s, child, level + 1);
2647 static int clk_summary_show(struct seq_file *s, void *data)
2650 struct hlist_head **lists = (struct hlist_head **)s->private;
2652 seq_puts(s, " enable prepare protect duty\n");
2653 seq_puts(s, " clock count count count rate accuracy phase cycle\n");
2654 seq_puts(s, "---------------------------------------------------------------------------------------------\n");
2658 for (; *lists; lists++)
2659 hlist_for_each_entry(c, *lists, child_node)
2660 clk_summary_show_subtree(s, c, 0);
2662 clk_prepare_unlock();
2666 DEFINE_SHOW_ATTRIBUTE(clk_summary);
2668 static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
2673 /* This should be JSON format, i.e. elements separated with a comma */
2674 seq_printf(s, "\"%s\": { ", c->name);
2675 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
2676 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
2677 seq_printf(s, "\"protect_count\": %d,", c->protect_count);
2678 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate(c));
2679 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c));
2680 seq_printf(s, "\"phase\": %d", clk_core_get_phase(c));
2681 seq_printf(s, "\"duty_cycle\": %u",
2682 clk_core_get_scaled_duty_cycle(c, 100000));
2685 static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
2687 struct clk_core *child;
2692 clk_dump_one(s, c, level);
2694 hlist_for_each_entry(child, &c->children, child_node) {
2696 clk_dump_subtree(s, child, level + 1);
2702 static int clk_dump_show(struct seq_file *s, void *data)
2705 bool first_node = true;
2706 struct hlist_head **lists = (struct hlist_head **)s->private;
2711 for (; *lists; lists++) {
2712 hlist_for_each_entry(c, *lists, child_node) {
2716 clk_dump_subtree(s, c, 0);
2720 clk_prepare_unlock();
2725 DEFINE_SHOW_ATTRIBUTE(clk_dump);
2727 static const struct {
2731 #define ENTRY(f) { f, #f }
2732 ENTRY(CLK_SET_RATE_GATE),
2733 ENTRY(CLK_SET_PARENT_GATE),
2734 ENTRY(CLK_SET_RATE_PARENT),
2735 ENTRY(CLK_IGNORE_UNUSED),
2736 ENTRY(CLK_IS_BASIC),
2737 ENTRY(CLK_GET_RATE_NOCACHE),
2738 ENTRY(CLK_SET_RATE_NO_REPARENT),
2739 ENTRY(CLK_GET_ACCURACY_NOCACHE),
2740 ENTRY(CLK_RECALC_NEW_RATES),
2741 ENTRY(CLK_SET_RATE_UNGATE),
2742 ENTRY(CLK_IS_CRITICAL),
2743 ENTRY(CLK_OPS_PARENT_ENABLE),
2744 ENTRY(CLK_DUTY_CYCLE_PARENT),
2748 static int clk_flags_show(struct seq_file *s, void *data)
2750 struct clk_core *core = s->private;
2751 unsigned long flags = core->flags;
2754 for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
2755 if (flags & clk_flags[i].flag) {
2756 seq_printf(s, "%s\n", clk_flags[i].name);
2757 flags &= ~clk_flags[i].flag;
2762 seq_printf(s, "0x%lx\n", flags);
2767 DEFINE_SHOW_ATTRIBUTE(clk_flags);
2769 static int possible_parents_show(struct seq_file *s, void *data)
2771 struct clk_core *core = s->private;
2774 for (i = 0; i < core->num_parents - 1; i++)
2775 seq_printf(s, "%s ", core->parent_names[i]);
2777 seq_printf(s, "%s\n", core->parent_names[i]);
2781 DEFINE_SHOW_ATTRIBUTE(possible_parents);
2783 static int clk_duty_cycle_show(struct seq_file *s, void *data)
2785 struct clk_core *core = s->private;
2786 struct clk_duty *duty = &core->duty;
2788 seq_printf(s, "%u/%u\n", duty->num, duty->den);
2792 DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
2794 static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
2796 struct dentry *root;
2798 if (!core || !pdentry)
2801 root = debugfs_create_dir(core->name, pdentry);
2802 core->dentry = root;
2804 debugfs_create_ulong("clk_rate", 0444, root, &core->rate);
2805 debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
2806 debugfs_create_u32("clk_phase", 0444, root, &core->phase);
2807 debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
2808 debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
2809 debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
2810 debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
2811 debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
2812 debugfs_create_file("clk_duty_cycle", 0444, root, core,
2813 &clk_duty_cycle_fops);
2815 if (core->num_parents > 1)
2816 debugfs_create_file("clk_possible_parents", 0444, root, core,
2817 &possible_parents_fops);
2819 if (core->ops->debug_init)
2820 core->ops->debug_init(core->hw, core->dentry);
2824 * clk_debug_register - add a clk node to the debugfs clk directory
2825 * @core: the clk being added to the debugfs clk directory
2827 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
2828 * initialized. Otherwise it bails out early since the debugfs clk directory
2829 * will be created lazily by clk_debug_init as part of a late_initcall.
2831 static void clk_debug_register(struct clk_core *core)
2833 mutex_lock(&clk_debug_lock);
2834 hlist_add_head(&core->debug_node, &clk_debug_list);
2836 clk_debug_create_one(core, rootdir);
2837 mutex_unlock(&clk_debug_lock);
2841 * clk_debug_unregister - remove a clk node from the debugfs clk directory
2842 * @core: the clk being removed from the debugfs clk directory
2844 * Dynamically removes a clk and all its child nodes from the
2845 * debugfs clk directory if clk->dentry points to debugfs created by
2846 * clk_debug_register in __clk_core_init.
2848 static void clk_debug_unregister(struct clk_core *core)
2850 mutex_lock(&clk_debug_lock);
2851 hlist_del_init(&core->debug_node);
2852 debugfs_remove_recursive(core->dentry);
2853 core->dentry = NULL;
2854 mutex_unlock(&clk_debug_lock);
2858 * clk_debug_init - lazily populate the debugfs clk directory
2860 * clks are often initialized very early during boot before memory can be
2861 * dynamically allocated and well before debugfs is setup. This function
2862 * populates the debugfs clk directory once at boot-time when we know that
2863 * debugfs is setup. It should only be called once at boot-time, all other clks
2864 * added dynamically will be done so with clk_debug_register.
2866 static int __init clk_debug_init(void)
2868 struct clk_core *core;
2870 rootdir = debugfs_create_dir("clk", NULL);
2872 debugfs_create_file("clk_summary", 0444, rootdir, &all_lists,
2874 debugfs_create_file("clk_dump", 0444, rootdir, &all_lists,
2876 debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list,
2878 debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list,
2881 mutex_lock(&clk_debug_lock);
2882 hlist_for_each_entry(core, &clk_debug_list, debug_node)
2883 clk_debug_create_one(core, rootdir);
2886 mutex_unlock(&clk_debug_lock);
2890 late_initcall(clk_debug_init);
2892 static inline void clk_debug_register(struct clk_core *core) { }
2893 static inline void clk_debug_reparent(struct clk_core *core,
2894 struct clk_core *new_parent)
2897 static inline void clk_debug_unregister(struct clk_core *core)
2903 * __clk_core_init - initialize the data structures in a struct clk_core
2904 * @core: clk_core being initialized
2906 * Initializes the lists in struct clk_core, queries the hardware for the
2907 * parent and rate and sets them both.
2909 static int __clk_core_init(struct clk_core *core)
2912 struct clk_core *orphan;
2913 struct hlist_node *tmp2;
2921 ret = clk_pm_runtime_get(core);
2925 /* check to see if a clock with this name is already registered */
2926 if (clk_core_lookup(core->name)) {
2927 pr_debug("%s: clk %s already initialized\n",
2928 __func__, core->name);
2933 /* check that clk_ops are sane. See Documentation/driver-api/clk.rst */
2934 if (core->ops->set_rate &&
2935 !((core->ops->round_rate || core->ops->determine_rate) &&
2936 core->ops->recalc_rate)) {
2937 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
2938 __func__, core->name);
2943 if (core->ops->set_parent && !core->ops->get_parent) {
2944 pr_err("%s: %s must implement .get_parent & .set_parent\n",
2945 __func__, core->name);
2950 if (core->num_parents > 1 && !core->ops->get_parent) {
2951 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
2952 __func__, core->name);
2957 if (core->ops->set_rate_and_parent &&
2958 !(core->ops->set_parent && core->ops->set_rate)) {
2959 pr_err("%s: %s must implement .set_parent & .set_rate\n",
2960 __func__, core->name);
2965 /* throw a WARN if any entries in parent_names are NULL */
2966 for (i = 0; i < core->num_parents; i++)
2967 WARN(!core->parent_names[i],
2968 "%s: invalid NULL in %s's .parent_names\n",
2969 __func__, core->name);
2971 core->parent = __clk_init_parent(core);
2974 * Populate core->parent if parent has already been clk_core_init'd. If
2975 * parent has not yet been clk_core_init'd then place clk in the orphan
2976 * list. If clk doesn't have any parents then place it in the root
2979 * Every time a new clk is clk_init'd then we walk the list of orphan
2980 * clocks and re-parent any that are children of the clock currently
2984 hlist_add_head(&core->child_node,
2985 &core->parent->children);
2986 core->orphan = core->parent->orphan;
2987 } else if (!core->num_parents) {
2988 hlist_add_head(&core->child_node, &clk_root_list);
2989 core->orphan = false;
2991 hlist_add_head(&core->child_node, &clk_orphan_list);
2992 core->orphan = true;
2996 * optional platform-specific magic
2998 * The .init callback is not used by any of the basic clock types, but
2999 * exists for weird hardware that must perform initialization magic.
3000 * Please consider other ways of solving initialization problems before
3001 * using this callback, as its use is discouraged.
3003 if (core->ops->init)
3004 core->ops->init(core->hw);
3007 * Set clk's accuracy. The preferred method is to use
3008 * .recalc_accuracy. For simple clocks and lazy developers the default
3009 * fallback is to use the parent's accuracy. If a clock doesn't have a
3010 * parent (or is orphaned) then accuracy is set to zero (perfect
3013 if (core->ops->recalc_accuracy)
3014 core->accuracy = core->ops->recalc_accuracy(core->hw,
3015 __clk_get_accuracy(core->parent));
3016 else if (core->parent)
3017 core->accuracy = core->parent->accuracy;
3023 * Since a phase is by definition relative to its parent, just
3024 * query the current clock phase, or just assume it's in phase.
3026 if (core->ops->get_phase)
3027 core->phase = core->ops->get_phase(core->hw);
3032 * Set clk's duty cycle.
3034 clk_core_update_duty_cycle_nolock(core);
3037 * Set clk's rate. The preferred method is to use .recalc_rate. For
3038 * simple clocks and lazy developers the default fallback is to use the
3039 * parent's rate. If a clock doesn't have a parent (or is orphaned)
3040 * then rate is set to zero.
3042 if (core->ops->recalc_rate)
3043 rate = core->ops->recalc_rate(core->hw,
3044 clk_core_get_rate_nolock(core->parent));
3045 else if (core->parent)
3046 rate = core->parent->rate;
3049 core->rate = core->req_rate = rate;
3052 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
3053 * don't get accidentally disabled when walking the orphan tree and
3054 * reparenting clocks
3056 if (core->flags & CLK_IS_CRITICAL) {
3057 unsigned long flags;
3059 clk_core_prepare(core);
3061 flags = clk_enable_lock();
3062 clk_core_enable(core);
3063 clk_enable_unlock(flags);
3067 * walk the list of orphan clocks and reparent any that newly finds a
3070 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
3071 struct clk_core *parent = __clk_init_parent(orphan);
3074 * We need to use __clk_set_parent_before() and _after() to
3075 * to properly migrate any prepare/enable count of the orphan
3076 * clock. This is important for CLK_IS_CRITICAL clocks, which
3077 * are enabled during init but might not have a parent yet.
3080 /* update the clk tree topology */
3081 __clk_set_parent_before(orphan, parent);
3082 __clk_set_parent_after(orphan, parent, NULL);
3083 __clk_recalc_accuracies(orphan);
3084 __clk_recalc_rates(orphan, 0);
3088 kref_init(&core->ref);
3090 clk_pm_runtime_put(core);
3092 clk_prepare_unlock();
3095 clk_debug_register(core);
3100 struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,
3105 /* This is to allow this function to be chained to others */
3106 if (IS_ERR_OR_NULL(hw))
3107 return ERR_CAST(hw);
3109 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
3111 return ERR_PTR(-ENOMEM);
3113 clk->core = hw->core;
3114 clk->dev_id = dev_id;
3115 clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
3116 clk->max_rate = ULONG_MAX;
3119 hlist_add_head(&clk->clks_node, &hw->core->clks);
3120 clk_prepare_unlock();
3125 void __clk_free_clk(struct clk *clk)
3128 hlist_del(&clk->clks_node);
3129 clk_prepare_unlock();
3131 kfree_const(clk->con_id);
3136 * clk_register - allocate a new clock, register it and return an opaque cookie
3137 * @dev: device that is registering this clock
3138 * @hw: link to hardware-specific clock data
3140 * clk_register is the primary interface for populating the clock tree with new
3141 * clock nodes. It returns a pointer to the newly allocated struct clk which
3142 * cannot be dereferenced by driver code but may be used in conjunction with the
3143 * rest of the clock API. In the event of an error clk_register will return an
3144 * error code; drivers must test for an error code after calling clk_register.
3146 struct clk *clk_register(struct device *dev, struct clk_hw *hw)
3149 struct clk_core *core;
3151 core = kzalloc(sizeof(*core), GFP_KERNEL);
3157 core->name = kstrdup_const(hw->init->name, GFP_KERNEL);
3163 if (WARN_ON(!hw->init->ops)) {
3167 core->ops = hw->init->ops;
3169 if (dev && pm_runtime_enabled(dev))
3171 if (dev && dev->driver)
3172 core->owner = dev->driver->owner;
3174 core->flags = hw->init->flags;
3175 core->num_parents = hw->init->num_parents;
3177 core->max_rate = ULONG_MAX;
3180 /* allocate local copy in case parent_names is __initdata */
3181 core->parent_names = kcalloc(core->num_parents, sizeof(char *),
3184 if (!core->parent_names) {
3186 goto fail_parent_names;
3190 /* copy each string name in case parent_names is __initdata */
3191 for (i = 0; i < core->num_parents; i++) {
3192 core->parent_names[i] = kstrdup_const(hw->init->parent_names[i],
3194 if (!core->parent_names[i]) {
3196 goto fail_parent_names_copy;
3200 /* avoid unnecessary string look-ups of clk_core's possible parents. */
3201 core->parents = kcalloc(core->num_parents, sizeof(*core->parents),
3203 if (!core->parents) {
3208 INIT_HLIST_HEAD(&core->clks);
3210 hw->clk = __clk_create_clk(hw, NULL, NULL);
3211 if (IS_ERR(hw->clk)) {
3212 ret = PTR_ERR(hw->clk);
3216 ret = __clk_core_init(core);
3220 __clk_free_clk(hw->clk);
3224 kfree(core->parents);
3225 fail_parent_names_copy:
3227 kfree_const(core->parent_names[i]);
3228 kfree(core->parent_names);
3231 kfree_const(core->name);
3235 return ERR_PTR(ret);
3237 EXPORT_SYMBOL_GPL(clk_register);
3240 * clk_hw_register - register a clk_hw and return an error code
3241 * @dev: device that is registering this clock
3242 * @hw: link to hardware-specific clock data
3244 * clk_hw_register is the primary interface for populating the clock tree with
3245 * new clock nodes. It returns an integer equal to zero indicating success or
3246 * less than zero indicating failure. Drivers must test for an error code after
3247 * calling clk_hw_register().
3249 int clk_hw_register(struct device *dev, struct clk_hw *hw)
3251 return PTR_ERR_OR_ZERO(clk_register(dev, hw));
3253 EXPORT_SYMBOL_GPL(clk_hw_register);
3255 /* Free memory allocated for a clock. */
3256 static void __clk_release(struct kref *ref)
3258 struct clk_core *core = container_of(ref, struct clk_core, ref);
3259 int i = core->num_parents;
3261 lockdep_assert_held(&prepare_lock);
3263 kfree(core->parents);
3265 kfree_const(core->parent_names[i]);
3267 kfree(core->parent_names);
3268 kfree_const(core->name);
3273 * Empty clk_ops for unregistered clocks. These are used temporarily
3274 * after clk_unregister() was called on a clock and until last clock
3275 * consumer calls clk_put() and the struct clk object is freed.
3277 static int clk_nodrv_prepare_enable(struct clk_hw *hw)
3282 static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
3287 static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
3288 unsigned long parent_rate)
3293 static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
3298 static const struct clk_ops clk_nodrv_ops = {
3299 .enable = clk_nodrv_prepare_enable,
3300 .disable = clk_nodrv_disable_unprepare,
3301 .prepare = clk_nodrv_prepare_enable,
3302 .unprepare = clk_nodrv_disable_unprepare,
3303 .set_rate = clk_nodrv_set_rate,
3304 .set_parent = clk_nodrv_set_parent,
3308 * clk_unregister - unregister a currently registered clock
3309 * @clk: clock to unregister
3311 void clk_unregister(struct clk *clk)
3313 unsigned long flags;
3315 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
3318 clk_debug_unregister(clk->core);
3322 if (clk->core->ops == &clk_nodrv_ops) {
3323 pr_err("%s: unregistered clock: %s\n", __func__,
3328 * Assign empty clock ops for consumers that might still hold
3329 * a reference to this clock.
3331 flags = clk_enable_lock();
3332 clk->core->ops = &clk_nodrv_ops;
3333 clk_enable_unlock(flags);
3335 if (!hlist_empty(&clk->core->children)) {
3336 struct clk_core *child;
3337 struct hlist_node *t;
3339 /* Reparent all children to the orphan list. */
3340 hlist_for_each_entry_safe(child, t, &clk->core->children,
3342 clk_core_set_parent_nolock(child, NULL);
3345 hlist_del_init(&clk->core->child_node);
3347 if (clk->core->prepare_count)
3348 pr_warn("%s: unregistering prepared clock: %s\n",
3349 __func__, clk->core->name);
3351 if (clk->core->protect_count)
3352 pr_warn("%s: unregistering protected clock: %s\n",
3353 __func__, clk->core->name);
3355 kref_put(&clk->core->ref, __clk_release);
3357 clk_prepare_unlock();
3359 EXPORT_SYMBOL_GPL(clk_unregister);
3362 * clk_hw_unregister - unregister a currently registered clk_hw
3363 * @hw: hardware-specific clock data to unregister
3365 void clk_hw_unregister(struct clk_hw *hw)
3367 clk_unregister(hw->clk);
3369 EXPORT_SYMBOL_GPL(clk_hw_unregister);
3371 static void devm_clk_release(struct device *dev, void *res)
3373 clk_unregister(*(struct clk **)res);
3376 static void devm_clk_hw_release(struct device *dev, void *res)
3378 clk_hw_unregister(*(struct clk_hw **)res);
3382 * devm_clk_register - resource managed clk_register()
3383 * @dev: device that is registering this clock
3384 * @hw: link to hardware-specific clock data
3386 * Managed clk_register(). Clocks returned from this function are
3387 * automatically clk_unregister()ed on driver detach. See clk_register() for
3390 struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
3395 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
3397 return ERR_PTR(-ENOMEM);
3399 clk = clk_register(dev, hw);
3402 devres_add(dev, clkp);
3409 EXPORT_SYMBOL_GPL(devm_clk_register);
3412 * devm_clk_hw_register - resource managed clk_hw_register()
3413 * @dev: device that is registering this clock
3414 * @hw: link to hardware-specific clock data
3416 * Managed clk_hw_register(). Clocks registered by this function are
3417 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
3418 * for more information.
3420 int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
3422 struct clk_hw **hwp;
3425 hwp = devres_alloc(devm_clk_hw_release, sizeof(*hwp), GFP_KERNEL);
3429 ret = clk_hw_register(dev, hw);
3432 devres_add(dev, hwp);
3439 EXPORT_SYMBOL_GPL(devm_clk_hw_register);
3441 static int devm_clk_match(struct device *dev, void *res, void *data)
3443 struct clk *c = res;
3449 static int devm_clk_hw_match(struct device *dev, void *res, void *data)
3451 struct clk_hw *hw = res;
3459 * devm_clk_unregister - resource managed clk_unregister()
3460 * @clk: clock to unregister
3462 * Deallocate a clock allocated with devm_clk_register(). Normally
3463 * this function will not need to be called and the resource management
3464 * code will ensure that the resource is freed.
3466 void devm_clk_unregister(struct device *dev, struct clk *clk)
3468 WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
3470 EXPORT_SYMBOL_GPL(devm_clk_unregister);
3473 * devm_clk_hw_unregister - resource managed clk_hw_unregister()
3474 * @dev: device that is unregistering the hardware-specific clock data
3475 * @hw: link to hardware-specific clock data
3477 * Unregister a clk_hw registered with devm_clk_hw_register(). Normally
3478 * this function will not need to be called and the resource management
3479 * code will ensure that the resource is freed.
3481 void devm_clk_hw_unregister(struct device *dev, struct clk_hw *hw)
3483 WARN_ON(devres_release(dev, devm_clk_hw_release, devm_clk_hw_match,
3486 EXPORT_SYMBOL_GPL(devm_clk_hw_unregister);
3491 int __clk_get(struct clk *clk)
3493 struct clk_core *core = !clk ? NULL : clk->core;
3496 if (!try_module_get(core->owner))
3499 kref_get(&core->ref);
3504 void __clk_put(struct clk *clk)
3506 struct module *owner;
3508 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
3514 * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
3515 * given user should be balanced with calls to clk_rate_exclusive_put()
3516 * and by that same consumer
3518 if (WARN_ON(clk->exclusive_count)) {
3519 /* We voiced our concern, let's sanitize the situation */
3520 clk->core->protect_count -= (clk->exclusive_count - 1);
3521 clk_core_rate_unprotect(clk->core);
3522 clk->exclusive_count = 0;
3525 hlist_del(&clk->clks_node);
3526 if (clk->min_rate > clk->core->req_rate ||
3527 clk->max_rate < clk->core->req_rate)
3528 clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
3530 owner = clk->core->owner;
3531 kref_put(&clk->core->ref, __clk_release);
3533 clk_prepare_unlock();
3540 /*** clk rate change notifiers ***/
3543 * clk_notifier_register - add a clk rate change notifier
3544 * @clk: struct clk * to watch
3545 * @nb: struct notifier_block * with callback info
3547 * Request notification when clk's rate changes. This uses an SRCU
3548 * notifier because we want it to block and notifier unregistrations are
3549 * uncommon. The callbacks associated with the notifier must not
3550 * re-enter into the clk framework by calling any top-level clk APIs;
3551 * this will cause a nested prepare_lock mutex.
3553 * In all notification cases (pre, post and abort rate change) the original
3554 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
3555 * and the new frequency is passed via struct clk_notifier_data.new_rate.
3557 * clk_notifier_register() must be called from non-atomic context.
3558 * Returns -EINVAL if called with null arguments, -ENOMEM upon
3559 * allocation failure; otherwise, passes along the return value of
3560 * srcu_notifier_chain_register().
3562 int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
3564 struct clk_notifier *cn;
3572 /* search the list of notifiers for this clk */
3573 list_for_each_entry(cn, &clk_notifier_list, node)
3577 /* if clk wasn't in the notifier list, allocate new clk_notifier */
3578 if (cn->clk != clk) {
3579 cn = kzalloc(sizeof(*cn), GFP_KERNEL);
3584 srcu_init_notifier_head(&cn->notifier_head);
3586 list_add(&cn->node, &clk_notifier_list);
3589 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
3591 clk->core->notifier_count++;
3594 clk_prepare_unlock();
3598 EXPORT_SYMBOL_GPL(clk_notifier_register);
3601 * clk_notifier_unregister - remove a clk rate change notifier
3602 * @clk: struct clk *
3603 * @nb: struct notifier_block * with callback info
3605 * Request no further notification for changes to 'clk' and frees memory
3606 * allocated in clk_notifier_register.
3608 * Returns -EINVAL if called with null arguments; otherwise, passes
3609 * along the return value of srcu_notifier_chain_unregister().
3611 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
3613 struct clk_notifier *cn = NULL;
3621 list_for_each_entry(cn, &clk_notifier_list, node)
3625 if (cn->clk == clk) {
3626 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
3628 clk->core->notifier_count--;
3630 /* XXX the notifier code should handle this better */
3631 if (!cn->notifier_head.head) {
3632 srcu_cleanup_notifier_head(&cn->notifier_head);
3633 list_del(&cn->node);
3641 clk_prepare_unlock();
3645 EXPORT_SYMBOL_GPL(clk_notifier_unregister);
3649 * struct of_clk_provider - Clock provider registration structure
3650 * @link: Entry in global list of clock providers
3651 * @node: Pointer to device tree node of clock provider
3652 * @get: Get clock callback. Returns NULL or a struct clk for the
3653 * given clock specifier
3654 * @data: context pointer to be passed into @get callback
3656 struct of_clk_provider {
3657 struct list_head link;
3659 struct device_node *node;
3660 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
3661 struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
3665 static const struct of_device_id __clk_of_table_sentinel
3666 __used __section(__clk_of_table_end);
3668 static LIST_HEAD(of_clk_providers);
3669 static DEFINE_MUTEX(of_clk_mutex);
3671 struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
3676 EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
3678 struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
3682 EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
3684 struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
3686 struct clk_onecell_data *clk_data = data;
3687 unsigned int idx = clkspec->args[0];
3689 if (idx >= clk_data->clk_num) {
3690 pr_err("%s: invalid clock index %u\n", __func__, idx);
3691 return ERR_PTR(-EINVAL);
3694 return clk_data->clks[idx];
3696 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
3699 of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
3701 struct clk_hw_onecell_data *hw_data = data;
3702 unsigned int idx = clkspec->args[0];
3704 if (idx >= hw_data->num) {
3705 pr_err("%s: invalid index %u\n", __func__, idx);
3706 return ERR_PTR(-EINVAL);
3709 return hw_data->hws[idx];
3711 EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
3714 * of_clk_add_provider() - Register a clock provider for a node
3715 * @np: Device node pointer associated with clock provider
3716 * @clk_src_get: callback for decoding clock
3717 * @data: context pointer for @clk_src_get callback.
3719 int of_clk_add_provider(struct device_node *np,
3720 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
3724 struct of_clk_provider *cp;
3727 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
3731 cp->node = of_node_get(np);
3733 cp->get = clk_src_get;
3735 mutex_lock(&of_clk_mutex);
3736 list_add(&cp->link, &of_clk_providers);
3737 mutex_unlock(&of_clk_mutex);
3738 pr_debug("Added clock from %pOF\n", np);
3740 ret = of_clk_set_defaults(np, true);
3742 of_clk_del_provider(np);
3746 EXPORT_SYMBOL_GPL(of_clk_add_provider);
3749 * of_clk_add_hw_provider() - Register a clock provider for a node
3750 * @np: Device node pointer associated with clock provider
3751 * @get: callback for decoding clk_hw
3752 * @data: context pointer for @get callback.
3754 int of_clk_add_hw_provider(struct device_node *np,
3755 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
3759 struct of_clk_provider *cp;
3762 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
3766 cp->node = of_node_get(np);
3770 mutex_lock(&of_clk_mutex);
3771 list_add(&cp->link, &of_clk_providers);
3772 mutex_unlock(&of_clk_mutex);
3773 pr_debug("Added clk_hw provider from %pOF\n", np);
3775 ret = of_clk_set_defaults(np, true);
3777 of_clk_del_provider(np);
3781 EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
3783 static void devm_of_clk_release_provider(struct device *dev, void *res)
3785 of_clk_del_provider(*(struct device_node **)res);
3788 int devm_of_clk_add_hw_provider(struct device *dev,
3789 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
3793 struct device_node **ptr, *np;
3796 ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
3802 ret = of_clk_add_hw_provider(np, get, data);
3805 devres_add(dev, ptr);
3812 EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);
3815 * of_clk_del_provider() - Remove a previously registered clock provider
3816 * @np: Device node pointer associated with clock provider
3818 void of_clk_del_provider(struct device_node *np)
3820 struct of_clk_provider *cp;
3822 mutex_lock(&of_clk_mutex);
3823 list_for_each_entry(cp, &of_clk_providers, link) {
3824 if (cp->node == np) {
3825 list_del(&cp->link);
3826 of_node_put(cp->node);
3831 mutex_unlock(&of_clk_mutex);
3833 EXPORT_SYMBOL_GPL(of_clk_del_provider);
3835 static int devm_clk_provider_match(struct device *dev, void *res, void *data)
3837 struct device_node **np = res;
3839 if (WARN_ON(!np || !*np))
3845 void devm_of_clk_del_provider(struct device *dev)
3849 ret = devres_release(dev, devm_of_clk_release_provider,
3850 devm_clk_provider_match, dev->of_node);
3854 EXPORT_SYMBOL(devm_of_clk_del_provider);
3856 static struct clk_hw *
3857 __of_clk_get_hw_from_provider(struct of_clk_provider *provider,
3858 struct of_phandle_args *clkspec)
3862 if (provider->get_hw)
3863 return provider->get_hw(clkspec, provider->data);
3865 clk = provider->get(clkspec, provider->data);
3867 return ERR_CAST(clk);
3868 return __clk_get_hw(clk);
3871 struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec,
3872 const char *dev_id, const char *con_id)
3874 struct of_clk_provider *provider;
3875 struct clk *clk = ERR_PTR(-EPROBE_DEFER);
3879 return ERR_PTR(-EINVAL);
3881 /* Check if we have such a provider in our array */
3882 mutex_lock(&of_clk_mutex);
3883 list_for_each_entry(provider, &of_clk_providers, link) {
3884 if (provider->node == clkspec->np) {
3885 hw = __of_clk_get_hw_from_provider(provider, clkspec);
3886 clk = __clk_create_clk(hw, dev_id, con_id);
3890 if (!__clk_get(clk)) {
3891 __clk_free_clk(clk);
3892 clk = ERR_PTR(-ENOENT);
3898 mutex_unlock(&of_clk_mutex);
3904 * of_clk_get_from_provider() - Lookup a clock from a clock provider
3905 * @clkspec: pointer to a clock specifier data structure
3907 * This function looks up a struct clk from the registered list of clock
3908 * providers, an input is a clock specifier data structure as returned
3909 * from the of_parse_phandle_with_args() function call.
3911 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
3913 return __of_clk_get_from_provider(clkspec, NULL, __func__);
3915 EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
3918 * of_clk_get_parent_count() - Count the number of clocks a device node has
3919 * @np: device node to count
3921 * Returns: The number of clocks that are possible parents of this node
3923 unsigned int of_clk_get_parent_count(struct device_node *np)
3927 count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
3933 EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
3935 const char *of_clk_get_parent_name(struct device_node *np, int index)
3937 struct of_phandle_args clkspec;
3938 struct property *prop;
3939 const char *clk_name;
3946 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
3951 index = clkspec.args_count ? clkspec.args[0] : 0;
3954 /* if there is an indices property, use it to transfer the index
3955 * specified into an array offset for the clock-output-names property.
3957 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
3964 /* We went off the end of 'clock-indices' without finding it */
3968 if (of_property_read_string_index(clkspec.np, "clock-output-names",
3972 * Best effort to get the name if the clock has been
3973 * registered with the framework. If the clock isn't
3974 * registered, we return the node name as the name of
3975 * the clock as long as #clock-cells = 0.
3977 clk = of_clk_get_from_provider(&clkspec);
3979 if (clkspec.args_count == 0)
3980 clk_name = clkspec.np->name;
3984 clk_name = __clk_get_name(clk);
3990 of_node_put(clkspec.np);
3993 EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
3996 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
3998 * @np: Device node pointer associated with clock provider
3999 * @parents: pointer to char array that hold the parents' names
4000 * @size: size of the @parents array
4002 * Return: number of parents for the clock node.
4004 int of_clk_parent_fill(struct device_node *np, const char **parents,
4009 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
4014 EXPORT_SYMBOL_GPL(of_clk_parent_fill);
4016 struct clock_provider {
4017 void (*clk_init_cb)(struct device_node *);
4018 struct device_node *np;
4019 struct list_head node;
4023 * This function looks for a parent clock. If there is one, then it
4024 * checks that the provider for this parent clock was initialized, in
4025 * this case the parent clock will be ready.
4027 static int parent_ready(struct device_node *np)
4032 struct clk *clk = of_clk_get(np, i);
4034 /* this parent is ready we can check the next one */
4041 /* at least one parent is not ready, we exit now */
4042 if (PTR_ERR(clk) == -EPROBE_DEFER)
4046 * Here we make assumption that the device tree is
4047 * written correctly. So an error means that there is
4048 * no more parent. As we didn't exit yet, then the
4049 * previous parent are ready. If there is no clock
4050 * parent, no need to wait for them, then we can
4051 * consider their absence as being ready
4058 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
4059 * @np: Device node pointer associated with clock provider
4060 * @index: clock index
4061 * @flags: pointer to top-level framework flags
4063 * Detects if the clock-critical property exists and, if so, sets the
4064 * corresponding CLK_IS_CRITICAL flag.
4066 * Do not use this function. It exists only for legacy Device Tree
4067 * bindings, such as the one-clock-per-node style that are outdated.
4068 * Those bindings typically put all clock data into .dts and the Linux
4069 * driver has no clock data, thus making it impossible to set this flag
4070 * correctly from the driver. Only those drivers may call
4071 * of_clk_detect_critical from their setup functions.
4073 * Return: error code or zero on success
4075 int of_clk_detect_critical(struct device_node *np,
4076 int index, unsigned long *flags)
4078 struct property *prop;
4085 of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
4087 *flags |= CLK_IS_CRITICAL;
4093 * of_clk_init() - Scan and init clock providers from the DT
4094 * @matches: array of compatible values and init functions for providers.
4096 * This function scans the device tree for matching clock providers
4097 * and calls their initialization functions. It also does it by trying
4098 * to follow the dependencies.
4100 void __init of_clk_init(const struct of_device_id *matches)
4102 const struct of_device_id *match;
4103 struct device_node *np;
4104 struct clock_provider *clk_provider, *next;
4107 LIST_HEAD(clk_provider_list);
4110 matches = &__clk_of_table;
4112 /* First prepare the list of the clocks providers */
4113 for_each_matching_node_and_match(np, matches, &match) {
4114 struct clock_provider *parent;
4116 if (!of_device_is_available(np))
4119 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
4121 list_for_each_entry_safe(clk_provider, next,
4122 &clk_provider_list, node) {
4123 list_del(&clk_provider->node);
4124 of_node_put(clk_provider->np);
4125 kfree(clk_provider);
4131 parent->clk_init_cb = match->data;
4132 parent->np = of_node_get(np);
4133 list_add_tail(&parent->node, &clk_provider_list);
4136 while (!list_empty(&clk_provider_list)) {
4137 is_init_done = false;
4138 list_for_each_entry_safe(clk_provider, next,
4139 &clk_provider_list, node) {
4140 if (force || parent_ready(clk_provider->np)) {
4142 /* Don't populate platform devices */
4143 of_node_set_flag(clk_provider->np,
4146 clk_provider->clk_init_cb(clk_provider->np);
4147 of_clk_set_defaults(clk_provider->np, true);
4149 list_del(&clk_provider->node);
4150 of_node_put(clk_provider->np);
4151 kfree(clk_provider);
4152 is_init_done = true;
4157 * We didn't manage to initialize any of the
4158 * remaining providers during the last loop, so now we
4159 * initialize all the remaining ones unconditionally
4160 * in case the clock parent was not mandatory