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/clk.txt
12 #include <linux/clk-provider.h>
13 #include <linux/clk/clk-conf.h>
14 #include <linux/module.h>
15 #include <linux/mutex.h>
16 #include <linux/spinlock.h>
17 #include <linux/err.h>
18 #include <linux/list.h>
19 #include <linux/slab.h>
21 #include <linux/device.h>
22 #include <linux/init.h>
23 #include <linux/sched.h>
24 #include <linux/clkdev.h>
28 static DEFINE_SPINLOCK(enable_lock);
29 static DEFINE_MUTEX(prepare_lock);
31 static struct task_struct *prepare_owner;
32 static struct task_struct *enable_owner;
34 static int prepare_refcnt;
35 static int enable_refcnt;
37 static HLIST_HEAD(clk_root_list);
38 static HLIST_HEAD(clk_orphan_list);
39 static LIST_HEAD(clk_notifier_list);
41 /*** private data structures ***/
45 const struct clk_ops *ops;
48 struct clk_core *parent;
49 const char **parent_names;
50 struct clk_core **parents;
54 unsigned long req_rate;
55 unsigned long new_rate;
56 struct clk_core *new_parent;
57 struct clk_core *new_child;
59 unsigned int enable_count;
60 unsigned int prepare_count;
61 unsigned long accuracy;
63 struct hlist_head children;
64 struct hlist_node child_node;
65 struct hlist_head clks;
66 unsigned int notifier_count;
67 #ifdef CONFIG_DEBUG_FS
68 struct dentry *dentry;
69 struct hlist_node debug_node;
74 #define CREATE_TRACE_POINTS
75 #include <trace/events/clk.h>
78 struct clk_core *core;
81 unsigned long min_rate;
82 unsigned long max_rate;
83 struct hlist_node clks_node;
87 static void clk_prepare_lock(void)
89 if (!mutex_trylock(&prepare_lock)) {
90 if (prepare_owner == current) {
94 mutex_lock(&prepare_lock);
96 WARN_ON_ONCE(prepare_owner != NULL);
97 WARN_ON_ONCE(prepare_refcnt != 0);
98 prepare_owner = current;
102 static void clk_prepare_unlock(void)
104 WARN_ON_ONCE(prepare_owner != current);
105 WARN_ON_ONCE(prepare_refcnt == 0);
107 if (--prepare_refcnt)
109 prepare_owner = NULL;
110 mutex_unlock(&prepare_lock);
113 static unsigned long clk_enable_lock(void)
117 if (!spin_trylock_irqsave(&enable_lock, flags)) {
118 if (enable_owner == current) {
122 spin_lock_irqsave(&enable_lock, flags);
124 WARN_ON_ONCE(enable_owner != NULL);
125 WARN_ON_ONCE(enable_refcnt != 0);
126 enable_owner = current;
131 static void clk_enable_unlock(unsigned long flags)
133 WARN_ON_ONCE(enable_owner != current);
134 WARN_ON_ONCE(enable_refcnt == 0);
139 spin_unlock_irqrestore(&enable_lock, flags);
142 static bool clk_core_is_prepared(struct clk_core *core)
145 * .is_prepared is optional for clocks that can prepare
146 * fall back to software usage counter if it is missing
148 if (!core->ops->is_prepared)
149 return core->prepare_count;
151 return core->ops->is_prepared(core->hw);
154 static bool clk_core_is_enabled(struct clk_core *core)
157 * .is_enabled is only mandatory for clocks that gate
158 * fall back to software usage counter if .is_enabled is missing
160 if (!core->ops->is_enabled)
161 return core->enable_count;
163 return core->ops->is_enabled(core->hw);
166 static void clk_unprepare_unused_subtree(struct clk_core *core)
168 struct clk_core *child;
170 lockdep_assert_held(&prepare_lock);
172 hlist_for_each_entry(child, &core->children, child_node)
173 clk_unprepare_unused_subtree(child);
175 if (core->prepare_count)
178 if (core->flags & CLK_IGNORE_UNUSED)
181 if (clk_core_is_prepared(core)) {
182 trace_clk_unprepare(core);
183 if (core->ops->unprepare_unused)
184 core->ops->unprepare_unused(core->hw);
185 else if (core->ops->unprepare)
186 core->ops->unprepare(core->hw);
187 trace_clk_unprepare_complete(core);
191 static void clk_disable_unused_subtree(struct clk_core *core)
193 struct clk_core *child;
196 lockdep_assert_held(&prepare_lock);
198 hlist_for_each_entry(child, &core->children, child_node)
199 clk_disable_unused_subtree(child);
201 flags = clk_enable_lock();
203 if (core->enable_count)
206 if (core->flags & CLK_IGNORE_UNUSED)
210 * some gate clocks have special needs during the disable-unused
211 * sequence. call .disable_unused if available, otherwise fall
214 if (clk_core_is_enabled(core)) {
215 trace_clk_disable(core);
216 if (core->ops->disable_unused)
217 core->ops->disable_unused(core->hw);
218 else if (core->ops->disable)
219 core->ops->disable(core->hw);
220 trace_clk_disable_complete(core);
224 clk_enable_unlock(flags);
227 static bool clk_ignore_unused;
228 static int __init clk_ignore_unused_setup(char *__unused)
230 clk_ignore_unused = true;
233 __setup("clk_ignore_unused", clk_ignore_unused_setup);
235 static int clk_disable_unused(void)
237 struct clk_core *core;
239 if (clk_ignore_unused) {
240 pr_warn("clk: Not disabling unused clocks\n");
246 hlist_for_each_entry(core, &clk_root_list, child_node)
247 clk_disable_unused_subtree(core);
249 hlist_for_each_entry(core, &clk_orphan_list, child_node)
250 clk_disable_unused_subtree(core);
252 hlist_for_each_entry(core, &clk_root_list, child_node)
253 clk_unprepare_unused_subtree(core);
255 hlist_for_each_entry(core, &clk_orphan_list, child_node)
256 clk_unprepare_unused_subtree(core);
258 clk_prepare_unlock();
262 late_initcall_sync(clk_disable_unused);
264 /*** helper functions ***/
266 const char *__clk_get_name(struct clk *clk)
268 return !clk ? NULL : clk->core->name;
270 EXPORT_SYMBOL_GPL(__clk_get_name);
272 struct clk_hw *__clk_get_hw(struct clk *clk)
274 return !clk ? NULL : clk->core->hw;
276 EXPORT_SYMBOL_GPL(__clk_get_hw);
278 u8 __clk_get_num_parents(struct clk *clk)
280 return !clk ? 0 : clk->core->num_parents;
282 EXPORT_SYMBOL_GPL(__clk_get_num_parents);
284 struct clk *__clk_get_parent(struct clk *clk)
289 /* TODO: Create a per-user clk and change callers to call clk_put */
290 return !clk->core->parent ? NULL : clk->core->parent->hw->clk;
292 EXPORT_SYMBOL_GPL(__clk_get_parent);
294 static struct clk_core *__clk_lookup_subtree(const char *name,
295 struct clk_core *core)
297 struct clk_core *child;
298 struct clk_core *ret;
300 if (!strcmp(core->name, name))
303 hlist_for_each_entry(child, &core->children, child_node) {
304 ret = __clk_lookup_subtree(name, child);
312 static struct clk_core *clk_core_lookup(const char *name)
314 struct clk_core *root_clk;
315 struct clk_core *ret;
320 /* search the 'proper' clk tree first */
321 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
322 ret = __clk_lookup_subtree(name, root_clk);
327 /* if not found, then search the orphan tree */
328 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
329 ret = __clk_lookup_subtree(name, root_clk);
337 static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
340 if (!core || index >= core->num_parents)
342 else if (!core->parents)
343 return clk_core_lookup(core->parent_names[index]);
344 else if (!core->parents[index])
345 return core->parents[index] =
346 clk_core_lookup(core->parent_names[index]);
348 return core->parents[index];
351 struct clk *clk_get_parent_by_index(struct clk *clk, u8 index)
353 struct clk_core *parent;
358 parent = clk_core_get_parent_by_index(clk->core, index);
360 return !parent ? NULL : parent->hw->clk;
362 EXPORT_SYMBOL_GPL(clk_get_parent_by_index);
364 unsigned int __clk_get_enable_count(struct clk *clk)
366 return !clk ? 0 : clk->core->enable_count;
369 static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
380 if (core->flags & CLK_IS_ROOT)
390 unsigned long __clk_get_rate(struct clk *clk)
395 return clk_core_get_rate_nolock(clk->core);
397 EXPORT_SYMBOL_GPL(__clk_get_rate);
399 static unsigned long __clk_get_accuracy(struct clk_core *core)
404 return core->accuracy;
407 unsigned long __clk_get_flags(struct clk *clk)
409 return !clk ? 0 : clk->core->flags;
411 EXPORT_SYMBOL_GPL(__clk_get_flags);
413 bool __clk_is_prepared(struct clk *clk)
418 return clk_core_is_prepared(clk->core);
421 bool __clk_is_enabled(struct clk *clk)
426 return clk_core_is_enabled(clk->core);
428 EXPORT_SYMBOL_GPL(__clk_is_enabled);
430 static bool mux_is_better_rate(unsigned long rate, unsigned long now,
431 unsigned long best, unsigned long flags)
433 if (flags & CLK_MUX_ROUND_CLOSEST)
434 return abs(now - rate) < abs(best - rate);
436 return now <= rate && now > best;
440 clk_mux_determine_rate_flags(struct clk_hw *hw, unsigned long rate,
441 unsigned long min_rate,
442 unsigned long max_rate,
443 unsigned long *best_parent_rate,
444 struct clk_hw **best_parent_p,
447 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
449 unsigned long parent_rate, best = 0;
451 /* if NO_REPARENT flag set, pass through to current parent */
452 if (core->flags & CLK_SET_RATE_NO_REPARENT) {
453 parent = core->parent;
454 if (core->flags & CLK_SET_RATE_PARENT)
455 best = __clk_determine_rate(parent ? parent->hw : NULL,
456 rate, min_rate, max_rate);
458 best = clk_core_get_rate_nolock(parent);
460 best = clk_core_get_rate_nolock(core);
464 /* find the parent that can provide the fastest rate <= rate */
465 num_parents = core->num_parents;
466 for (i = 0; i < num_parents; i++) {
467 parent = clk_core_get_parent_by_index(core, i);
470 if (core->flags & CLK_SET_RATE_PARENT)
471 parent_rate = __clk_determine_rate(parent->hw, rate,
475 parent_rate = clk_core_get_rate_nolock(parent);
476 if (mux_is_better_rate(rate, parent_rate, best, flags)) {
477 best_parent = parent;
484 *best_parent_p = best_parent->hw;
485 *best_parent_rate = best;
490 struct clk *__clk_lookup(const char *name)
492 struct clk_core *core = clk_core_lookup(name);
494 return !core ? NULL : core->hw->clk;
497 static void clk_core_get_boundaries(struct clk_core *core,
498 unsigned long *min_rate,
499 unsigned long *max_rate)
501 struct clk *clk_user;
504 *max_rate = ULONG_MAX;
506 hlist_for_each_entry(clk_user, &core->clks, clks_node)
507 *min_rate = max(*min_rate, clk_user->min_rate);
509 hlist_for_each_entry(clk_user, &core->clks, clks_node)
510 *max_rate = min(*max_rate, clk_user->max_rate);
514 * Helper for finding best parent to provide a given frequency. This can be used
515 * directly as a determine_rate callback (e.g. for a mux), or from a more
516 * complex clock that may combine a mux with other operations.
518 long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate,
519 unsigned long min_rate,
520 unsigned long max_rate,
521 unsigned long *best_parent_rate,
522 struct clk_hw **best_parent_p)
524 return clk_mux_determine_rate_flags(hw, rate, min_rate, max_rate,
528 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
530 long __clk_mux_determine_rate_closest(struct clk_hw *hw, unsigned long rate,
531 unsigned long min_rate,
532 unsigned long max_rate,
533 unsigned long *best_parent_rate,
534 struct clk_hw **best_parent_p)
536 return clk_mux_determine_rate_flags(hw, rate, min_rate, max_rate,
539 CLK_MUX_ROUND_CLOSEST);
541 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
545 static void clk_core_unprepare(struct clk_core *core)
547 lockdep_assert_held(&prepare_lock);
552 if (WARN_ON(core->prepare_count == 0))
555 if (--core->prepare_count > 0)
558 WARN_ON(core->enable_count > 0);
560 trace_clk_unprepare(core);
562 if (core->ops->unprepare)
563 core->ops->unprepare(core->hw);
565 trace_clk_unprepare_complete(core);
566 clk_core_unprepare(core->parent);
570 * clk_unprepare - undo preparation of a clock source
571 * @clk: the clk being unprepared
573 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
574 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
575 * if the operation may sleep. One example is a clk which is accessed over
576 * I2c. In the complex case a clk gate operation may require a fast and a slow
577 * part. It is this reason that clk_unprepare and clk_disable are not mutually
578 * exclusive. In fact clk_disable must be called before clk_unprepare.
580 void clk_unprepare(struct clk *clk)
582 if (IS_ERR_OR_NULL(clk))
586 clk_core_unprepare(clk->core);
587 clk_prepare_unlock();
589 EXPORT_SYMBOL_GPL(clk_unprepare);
591 static int clk_core_prepare(struct clk_core *core)
595 lockdep_assert_held(&prepare_lock);
600 if (core->prepare_count == 0) {
601 ret = clk_core_prepare(core->parent);
605 trace_clk_prepare(core);
607 if (core->ops->prepare)
608 ret = core->ops->prepare(core->hw);
610 trace_clk_prepare_complete(core);
613 clk_core_unprepare(core->parent);
618 core->prepare_count++;
624 * clk_prepare - prepare a clock source
625 * @clk: the clk being prepared
627 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
628 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
629 * operation may sleep. One example is a clk which is accessed over I2c. In
630 * the complex case a clk ungate operation may require a fast and a slow part.
631 * It is this reason that clk_prepare and clk_enable are not mutually
632 * exclusive. In fact clk_prepare must be called before clk_enable.
633 * Returns 0 on success, -EERROR otherwise.
635 int clk_prepare(struct clk *clk)
643 ret = clk_core_prepare(clk->core);
644 clk_prepare_unlock();
648 EXPORT_SYMBOL_GPL(clk_prepare);
650 static void clk_core_disable(struct clk_core *core)
652 lockdep_assert_held(&enable_lock);
657 if (WARN_ON(core->enable_count == 0))
660 if (--core->enable_count > 0)
663 trace_clk_disable(core);
665 if (core->ops->disable)
666 core->ops->disable(core->hw);
668 trace_clk_disable_complete(core);
670 clk_core_disable(core->parent);
674 * clk_disable - gate a clock
675 * @clk: the clk being gated
677 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
678 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
679 * clk if the operation is fast and will never sleep. One example is a
680 * SoC-internal clk which is controlled via simple register writes. In the
681 * complex case a clk gate operation may require a fast and a slow part. It is
682 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
683 * In fact clk_disable must be called before clk_unprepare.
685 void clk_disable(struct clk *clk)
689 if (IS_ERR_OR_NULL(clk))
692 flags = clk_enable_lock();
693 clk_core_disable(clk->core);
694 clk_enable_unlock(flags);
696 EXPORT_SYMBOL_GPL(clk_disable);
698 static int clk_core_enable(struct clk_core *core)
702 lockdep_assert_held(&enable_lock);
707 if (WARN_ON(core->prepare_count == 0))
710 if (core->enable_count == 0) {
711 ret = clk_core_enable(core->parent);
716 trace_clk_enable(core);
718 if (core->ops->enable)
719 ret = core->ops->enable(core->hw);
721 trace_clk_enable_complete(core);
724 clk_core_disable(core->parent);
729 core->enable_count++;
734 * clk_enable - ungate a clock
735 * @clk: the clk being ungated
737 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
738 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
739 * if the operation will never sleep. One example is a SoC-internal clk which
740 * is controlled via simple register writes. In the complex case a clk ungate
741 * operation may require a fast and a slow part. It is this reason that
742 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
743 * must be called before clk_enable. Returns 0 on success, -EERROR
746 int clk_enable(struct clk *clk)
754 flags = clk_enable_lock();
755 ret = clk_core_enable(clk->core);
756 clk_enable_unlock(flags);
760 EXPORT_SYMBOL_GPL(clk_enable);
762 static unsigned long clk_core_round_rate_nolock(struct clk_core *core,
764 unsigned long min_rate,
765 unsigned long max_rate)
767 unsigned long parent_rate = 0;
768 struct clk_core *parent;
769 struct clk_hw *parent_hw;
771 lockdep_assert_held(&prepare_lock);
776 parent = core->parent;
778 parent_rate = parent->rate;
780 if (core->ops->determine_rate) {
781 parent_hw = parent ? parent->hw : NULL;
782 return core->ops->determine_rate(core->hw, rate,
784 &parent_rate, &parent_hw);
785 } else if (core->ops->round_rate)
786 return core->ops->round_rate(core->hw, rate, &parent_rate);
787 else if (core->flags & CLK_SET_RATE_PARENT)
788 return clk_core_round_rate_nolock(core->parent, rate, min_rate,
795 * __clk_determine_rate - get the closest rate actually supported by a clock
796 * @hw: determine the rate of this clock
798 * @min_rate: returned rate must be greater than this rate
799 * @max_rate: returned rate must be less than this rate
801 * Useful for clk_ops such as .set_rate and .determine_rate.
803 unsigned long __clk_determine_rate(struct clk_hw *hw,
805 unsigned long min_rate,
806 unsigned long max_rate)
811 return clk_core_round_rate_nolock(hw->core, rate, min_rate, max_rate);
813 EXPORT_SYMBOL_GPL(__clk_determine_rate);
816 * __clk_round_rate - round the given rate for a clk
817 * @clk: round the rate of this clock
818 * @rate: the rate which is to be rounded
820 * Useful for clk_ops such as .set_rate
822 unsigned long __clk_round_rate(struct clk *clk, unsigned long rate)
824 unsigned long min_rate;
825 unsigned long max_rate;
830 clk_core_get_boundaries(clk->core, &min_rate, &max_rate);
832 return clk_core_round_rate_nolock(clk->core, rate, min_rate, max_rate);
834 EXPORT_SYMBOL_GPL(__clk_round_rate);
837 * clk_round_rate - round the given rate for a clk
838 * @clk: the clk for which we are rounding a rate
839 * @rate: the rate which is to be rounded
841 * Takes in a rate as input and rounds it to a rate that the clk can actually
842 * use which is then returned. If clk doesn't support round_rate operation
843 * then the parent rate is returned.
845 long clk_round_rate(struct clk *clk, unsigned long rate)
853 ret = __clk_round_rate(clk, rate);
854 clk_prepare_unlock();
858 EXPORT_SYMBOL_GPL(clk_round_rate);
861 * __clk_notify - call clk notifier chain
862 * @core: clk that is changing rate
863 * @msg: clk notifier type (see include/linux/clk.h)
864 * @old_rate: old clk rate
865 * @new_rate: new clk rate
867 * Triggers a notifier call chain on the clk rate-change notification
868 * for 'clk'. Passes a pointer to the struct clk and the previous
869 * and current rates to the notifier callback. Intended to be called by
870 * internal clock code only. Returns NOTIFY_DONE from the last driver
871 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
872 * a driver returns that.
874 static int __clk_notify(struct clk_core *core, unsigned long msg,
875 unsigned long old_rate, unsigned long new_rate)
877 struct clk_notifier *cn;
878 struct clk_notifier_data cnd;
879 int ret = NOTIFY_DONE;
881 cnd.old_rate = old_rate;
882 cnd.new_rate = new_rate;
884 list_for_each_entry(cn, &clk_notifier_list, node) {
885 if (cn->clk->core == core) {
887 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
896 * __clk_recalc_accuracies
897 * @core: first clk in the subtree
899 * Walks the subtree of clks starting with clk and recalculates accuracies as
900 * it goes. Note that if a clk does not implement the .recalc_accuracy
901 * callback then it is assumed that the clock will take on the accuracy of its
904 static void __clk_recalc_accuracies(struct clk_core *core)
906 unsigned long parent_accuracy = 0;
907 struct clk_core *child;
909 lockdep_assert_held(&prepare_lock);
912 parent_accuracy = core->parent->accuracy;
914 if (core->ops->recalc_accuracy)
915 core->accuracy = core->ops->recalc_accuracy(core->hw,
918 core->accuracy = parent_accuracy;
920 hlist_for_each_entry(child, &core->children, child_node)
921 __clk_recalc_accuracies(child);
924 static long clk_core_get_accuracy(struct clk_core *core)
926 unsigned long accuracy;
929 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
930 __clk_recalc_accuracies(core);
932 accuracy = __clk_get_accuracy(core);
933 clk_prepare_unlock();
939 * clk_get_accuracy - return the accuracy of clk
940 * @clk: the clk whose accuracy is being returned
942 * Simply returns the cached accuracy of the clk, unless
943 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
945 * If clk is NULL then returns 0.
947 long clk_get_accuracy(struct clk *clk)
952 return clk_core_get_accuracy(clk->core);
954 EXPORT_SYMBOL_GPL(clk_get_accuracy);
956 static unsigned long clk_recalc(struct clk_core *core,
957 unsigned long parent_rate)
959 if (core->ops->recalc_rate)
960 return core->ops->recalc_rate(core->hw, parent_rate);
966 * @core: first clk in the subtree
967 * @msg: notification type (see include/linux/clk.h)
969 * Walks the subtree of clks starting with clk and recalculates rates as it
970 * goes. Note that if a clk does not implement the .recalc_rate callback then
971 * it is assumed that the clock will take on the rate of its parent.
973 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
976 static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
978 unsigned long old_rate;
979 unsigned long parent_rate = 0;
980 struct clk_core *child;
982 lockdep_assert_held(&prepare_lock);
984 old_rate = core->rate;
987 parent_rate = core->parent->rate;
989 core->rate = clk_recalc(core, parent_rate);
992 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
993 * & ABORT_RATE_CHANGE notifiers
995 if (core->notifier_count && msg)
996 __clk_notify(core, msg, old_rate, core->rate);
998 hlist_for_each_entry(child, &core->children, child_node)
999 __clk_recalc_rates(child, msg);
1002 static unsigned long clk_core_get_rate(struct clk_core *core)
1008 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1009 __clk_recalc_rates(core, 0);
1011 rate = clk_core_get_rate_nolock(core);
1012 clk_prepare_unlock();
1018 * clk_get_rate - return the rate of clk
1019 * @clk: the clk whose rate is being returned
1021 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1022 * is set, which means a recalc_rate will be issued.
1023 * If clk is NULL then returns 0.
1025 unsigned long clk_get_rate(struct clk *clk)
1030 return clk_core_get_rate(clk->core);
1032 EXPORT_SYMBOL_GPL(clk_get_rate);
1034 static int clk_fetch_parent_index(struct clk_core *core,
1035 struct clk_core *parent)
1039 if (!core->parents) {
1040 core->parents = kcalloc(core->num_parents,
1041 sizeof(struct clk *), GFP_KERNEL);
1047 * find index of new parent clock using cached parent ptrs,
1048 * or if not yet cached, use string name comparison and cache
1049 * them now to avoid future calls to clk_core_lookup.
1051 for (i = 0; i < core->num_parents; i++) {
1052 if (core->parents[i] == parent)
1055 if (core->parents[i])
1058 if (!strcmp(core->parent_names[i], parent->name)) {
1059 core->parents[i] = clk_core_lookup(parent->name);
1067 static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1069 hlist_del(&core->child_node);
1072 /* avoid duplicate POST_RATE_CHANGE notifications */
1073 if (new_parent->new_child == core)
1074 new_parent->new_child = NULL;
1076 hlist_add_head(&core->child_node, &new_parent->children);
1078 hlist_add_head(&core->child_node, &clk_orphan_list);
1081 core->parent = new_parent;
1084 static struct clk_core *__clk_set_parent_before(struct clk_core *core,
1085 struct clk_core *parent)
1087 unsigned long flags;
1088 struct clk_core *old_parent = core->parent;
1091 * Migrate prepare state between parents and prevent race with
1094 * If the clock is not prepared, then a race with
1095 * clk_enable/disable() is impossible since we already have the
1096 * prepare lock (future calls to clk_enable() need to be preceded by
1099 * If the clock is prepared, migrate the prepared state to the new
1100 * parent and also protect against a race with clk_enable() by
1101 * forcing the clock and the new parent on. This ensures that all
1102 * future calls to clk_enable() are practically NOPs with respect to
1103 * hardware and software states.
1105 * See also: Comment for clk_set_parent() below.
1107 if (core->prepare_count) {
1108 clk_core_prepare(parent);
1109 flags = clk_enable_lock();
1110 clk_core_enable(parent);
1111 clk_core_enable(core);
1112 clk_enable_unlock(flags);
1115 /* update the clk tree topology */
1116 flags = clk_enable_lock();
1117 clk_reparent(core, parent);
1118 clk_enable_unlock(flags);
1123 static void __clk_set_parent_after(struct clk_core *core,
1124 struct clk_core *parent,
1125 struct clk_core *old_parent)
1127 unsigned long flags;
1130 * Finish the migration of prepare state and undo the changes done
1131 * for preventing a race with clk_enable().
1133 if (core->prepare_count) {
1134 flags = clk_enable_lock();
1135 clk_core_disable(core);
1136 clk_core_disable(old_parent);
1137 clk_enable_unlock(flags);
1138 clk_core_unprepare(old_parent);
1142 static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
1145 unsigned long flags;
1147 struct clk_core *old_parent;
1149 old_parent = __clk_set_parent_before(core, parent);
1151 trace_clk_set_parent(core, parent);
1153 /* change clock input source */
1154 if (parent && core->ops->set_parent)
1155 ret = core->ops->set_parent(core->hw, p_index);
1157 trace_clk_set_parent_complete(core, parent);
1160 flags = clk_enable_lock();
1161 clk_reparent(core, old_parent);
1162 clk_enable_unlock(flags);
1164 if (core->prepare_count) {
1165 flags = clk_enable_lock();
1166 clk_core_disable(core);
1167 clk_core_disable(parent);
1168 clk_enable_unlock(flags);
1169 clk_core_unprepare(parent);
1174 __clk_set_parent_after(core, parent, old_parent);
1180 * __clk_speculate_rates
1181 * @core: first clk in the subtree
1182 * @parent_rate: the "future" rate of clk's parent
1184 * Walks the subtree of clks starting with clk, speculating rates as it
1185 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1187 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1188 * pre-rate change notifications and returns early if no clks in the
1189 * subtree have subscribed to the notifications. Note that if a clk does not
1190 * implement the .recalc_rate callback then it is assumed that the clock will
1191 * take on the rate of its parent.
1193 static int __clk_speculate_rates(struct clk_core *core,
1194 unsigned long parent_rate)
1196 struct clk_core *child;
1197 unsigned long new_rate;
1198 int ret = NOTIFY_DONE;
1200 lockdep_assert_held(&prepare_lock);
1202 new_rate = clk_recalc(core, parent_rate);
1204 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1205 if (core->notifier_count)
1206 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
1208 if (ret & NOTIFY_STOP_MASK) {
1209 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1210 __func__, core->name, ret);
1214 hlist_for_each_entry(child, &core->children, child_node) {
1215 ret = __clk_speculate_rates(child, new_rate);
1216 if (ret & NOTIFY_STOP_MASK)
1224 static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
1225 struct clk_core *new_parent, u8 p_index)
1227 struct clk_core *child;
1229 core->new_rate = new_rate;
1230 core->new_parent = new_parent;
1231 core->new_parent_index = p_index;
1232 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1233 core->new_child = NULL;
1234 if (new_parent && new_parent != core->parent)
1235 new_parent->new_child = core;
1237 hlist_for_each_entry(child, &core->children, child_node) {
1238 child->new_rate = clk_recalc(child, new_rate);
1239 clk_calc_subtree(child, child->new_rate, NULL, 0);
1244 * calculate the new rates returning the topmost clock that has to be
1247 static struct clk_core *clk_calc_new_rates(struct clk_core *core,
1250 struct clk_core *top = core;
1251 struct clk_core *old_parent, *parent;
1252 struct clk_hw *parent_hw;
1253 unsigned long best_parent_rate = 0;
1254 unsigned long new_rate;
1255 unsigned long min_rate;
1256 unsigned long max_rate;
1261 if (IS_ERR_OR_NULL(core))
1264 /* save parent rate, if it exists */
1265 parent = old_parent = core->parent;
1267 best_parent_rate = parent->rate;
1269 clk_core_get_boundaries(core, &min_rate, &max_rate);
1271 /* find the closest rate and parent clk/rate */
1272 if (core->ops->determine_rate) {
1273 parent_hw = parent ? parent->hw : NULL;
1274 ret = core->ops->determine_rate(core->hw, rate,
1283 parent = parent_hw ? parent_hw->core : NULL;
1284 } else if (core->ops->round_rate) {
1285 ret = core->ops->round_rate(core->hw, rate,
1291 if (new_rate < min_rate || new_rate > max_rate)
1293 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
1294 /* pass-through clock without adjustable parent */
1295 core->new_rate = core->rate;
1298 /* pass-through clock with adjustable parent */
1299 top = clk_calc_new_rates(parent, rate);
1300 new_rate = parent->new_rate;
1304 /* some clocks must be gated to change parent */
1305 if (parent != old_parent &&
1306 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1307 pr_debug("%s: %s not gated but wants to reparent\n",
1308 __func__, core->name);
1312 /* try finding the new parent index */
1313 if (parent && core->num_parents > 1) {
1314 p_index = clk_fetch_parent_index(core, parent);
1316 pr_debug("%s: clk %s can not be parent of clk %s\n",
1317 __func__, parent->name, core->name);
1322 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
1323 best_parent_rate != parent->rate)
1324 top = clk_calc_new_rates(parent, best_parent_rate);
1327 clk_calc_subtree(core, new_rate, parent, p_index);
1333 * Notify about rate changes in a subtree. Always walk down the whole tree
1334 * so that in case of an error we can walk down the whole tree again and
1337 static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
1338 unsigned long event)
1340 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
1341 int ret = NOTIFY_DONE;
1343 if (core->rate == core->new_rate)
1346 if (core->notifier_count) {
1347 ret = __clk_notify(core, event, core->rate, core->new_rate);
1348 if (ret & NOTIFY_STOP_MASK)
1352 hlist_for_each_entry(child, &core->children, child_node) {
1353 /* Skip children who will be reparented to another clock */
1354 if (child->new_parent && child->new_parent != core)
1356 tmp_clk = clk_propagate_rate_change(child, event);
1361 /* handle the new child who might not be in core->children yet */
1362 if (core->new_child) {
1363 tmp_clk = clk_propagate_rate_change(core->new_child, event);
1372 * walk down a subtree and set the new rates notifying the rate
1375 static void clk_change_rate(struct clk_core *core)
1377 struct clk_core *child;
1378 struct hlist_node *tmp;
1379 unsigned long old_rate;
1380 unsigned long best_parent_rate = 0;
1381 bool skip_set_rate = false;
1382 struct clk_core *old_parent;
1384 old_rate = core->rate;
1386 if (core->new_parent)
1387 best_parent_rate = core->new_parent->rate;
1388 else if (core->parent)
1389 best_parent_rate = core->parent->rate;
1391 if (core->new_parent && core->new_parent != core->parent) {
1392 old_parent = __clk_set_parent_before(core, core->new_parent);
1393 trace_clk_set_parent(core, core->new_parent);
1395 if (core->ops->set_rate_and_parent) {
1396 skip_set_rate = true;
1397 core->ops->set_rate_and_parent(core->hw, core->new_rate,
1399 core->new_parent_index);
1400 } else if (core->ops->set_parent) {
1401 core->ops->set_parent(core->hw, core->new_parent_index);
1404 trace_clk_set_parent_complete(core, core->new_parent);
1405 __clk_set_parent_after(core, core->new_parent, old_parent);
1408 trace_clk_set_rate(core, core->new_rate);
1410 if (!skip_set_rate && core->ops->set_rate)
1411 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
1413 trace_clk_set_rate_complete(core, core->new_rate);
1415 core->rate = clk_recalc(core, best_parent_rate);
1417 if (core->notifier_count && old_rate != core->rate)
1418 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
1421 * Use safe iteration, as change_rate can actually swap parents
1422 * for certain clock types.
1424 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
1425 /* Skip children who will be reparented to another clock */
1426 if (child->new_parent && child->new_parent != core)
1428 clk_change_rate(child);
1431 /* handle the new child who might not be in core->children yet */
1432 if (core->new_child)
1433 clk_change_rate(core->new_child);
1436 static int clk_core_set_rate_nolock(struct clk_core *core,
1437 unsigned long req_rate)
1439 struct clk_core *top, *fail_clk;
1440 unsigned long rate = req_rate;
1446 /* bail early if nothing to do */
1447 if (rate == clk_core_get_rate_nolock(core))
1450 if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count)
1453 /* calculate new rates and get the topmost changed clock */
1454 top = clk_calc_new_rates(core, rate);
1458 /* notify that we are about to change rates */
1459 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
1461 pr_debug("%s: failed to set %s rate\n", __func__,
1463 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
1467 /* change the rates */
1468 clk_change_rate(top);
1470 core->req_rate = req_rate;
1476 * clk_set_rate - specify a new rate for clk
1477 * @clk: the clk whose rate is being changed
1478 * @rate: the new rate for clk
1480 * In the simplest case clk_set_rate will only adjust the rate of clk.
1482 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1483 * propagate up to clk's parent; whether or not this happens depends on the
1484 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1485 * after calling .round_rate then upstream parent propagation is ignored. If
1486 * *parent_rate comes back with a new rate for clk's parent then we propagate
1487 * up to clk's parent and set its rate. Upward propagation will continue
1488 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1489 * .round_rate stops requesting changes to clk's parent_rate.
1491 * Rate changes are accomplished via tree traversal that also recalculates the
1492 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
1494 * Returns 0 on success, -EERROR otherwise.
1496 int clk_set_rate(struct clk *clk, unsigned long rate)
1503 /* prevent racing with updates to the clock topology */
1506 ret = clk_core_set_rate_nolock(clk->core, rate);
1508 clk_prepare_unlock();
1512 EXPORT_SYMBOL_GPL(clk_set_rate);
1515 * clk_set_rate_range - set a rate range for a clock source
1516 * @clk: clock source
1517 * @min: desired minimum clock rate in Hz, inclusive
1518 * @max: desired maximum clock rate in Hz, inclusive
1520 * Returns success (0) or negative errno.
1522 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
1530 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
1531 __func__, clk->core->name, clk->dev_id, clk->con_id,
1538 if (min != clk->min_rate || max != clk->max_rate) {
1539 clk->min_rate = min;
1540 clk->max_rate = max;
1541 ret = clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
1544 clk_prepare_unlock();
1548 EXPORT_SYMBOL_GPL(clk_set_rate_range);
1551 * clk_set_min_rate - set a minimum clock rate for a clock source
1552 * @clk: clock source
1553 * @rate: desired minimum clock rate in Hz, inclusive
1555 * Returns success (0) or negative errno.
1557 int clk_set_min_rate(struct clk *clk, unsigned long rate)
1562 return clk_set_rate_range(clk, rate, clk->max_rate);
1564 EXPORT_SYMBOL_GPL(clk_set_min_rate);
1567 * clk_set_max_rate - set a maximum clock rate for a clock source
1568 * @clk: clock source
1569 * @rate: desired maximum clock rate in Hz, inclusive
1571 * Returns success (0) or negative errno.
1573 int clk_set_max_rate(struct clk *clk, unsigned long rate)
1578 return clk_set_rate_range(clk, clk->min_rate, rate);
1580 EXPORT_SYMBOL_GPL(clk_set_max_rate);
1583 * clk_get_parent - return the parent of a clk
1584 * @clk: the clk whose parent gets returned
1586 * Simply returns clk->parent. Returns NULL if clk is NULL.
1588 struct clk *clk_get_parent(struct clk *clk)
1593 parent = __clk_get_parent(clk);
1594 clk_prepare_unlock();
1598 EXPORT_SYMBOL_GPL(clk_get_parent);
1601 * .get_parent is mandatory for clocks with multiple possible parents. It is
1602 * optional for single-parent clocks. Always call .get_parent if it is
1603 * available and WARN if it is missing for multi-parent clocks.
1605 * For single-parent clocks without .get_parent, first check to see if the
1606 * .parents array exists, and if so use it to avoid an expensive tree
1607 * traversal. If .parents does not exist then walk the tree.
1609 static struct clk_core *__clk_init_parent(struct clk_core *core)
1611 struct clk_core *ret = NULL;
1614 /* handle the trivial cases */
1616 if (!core->num_parents)
1619 if (core->num_parents == 1) {
1620 if (IS_ERR_OR_NULL(core->parent))
1621 core->parent = clk_core_lookup(core->parent_names[0]);
1626 if (!core->ops->get_parent) {
1627 WARN(!core->ops->get_parent,
1628 "%s: multi-parent clocks must implement .get_parent\n",
1634 * Do our best to cache parent clocks in core->parents. This prevents
1635 * unnecessary and expensive lookups. We don't set core->parent here;
1636 * that is done by the calling function.
1639 index = core->ops->get_parent(core->hw);
1643 kcalloc(core->num_parents, sizeof(struct clk *),
1646 ret = clk_core_get_parent_by_index(core, index);
1652 static void clk_core_reparent(struct clk_core *core,
1653 struct clk_core *new_parent)
1655 clk_reparent(core, new_parent);
1656 __clk_recalc_accuracies(core);
1657 __clk_recalc_rates(core, POST_RATE_CHANGE);
1661 * clk_has_parent - check if a clock is a possible parent for another
1662 * @clk: clock source
1663 * @parent: parent clock source
1665 * This function can be used in drivers that need to check that a clock can be
1666 * the parent of another without actually changing the parent.
1668 * Returns true if @parent is a possible parent for @clk, false otherwise.
1670 bool clk_has_parent(struct clk *clk, struct clk *parent)
1672 struct clk_core *core, *parent_core;
1675 /* NULL clocks should be nops, so return success if either is NULL. */
1676 if (!clk || !parent)
1680 parent_core = parent->core;
1682 /* Optimize for the case where the parent is already the parent. */
1683 if (core->parent == parent_core)
1686 for (i = 0; i < core->num_parents; i++)
1687 if (strcmp(core->parent_names[i], parent_core->name) == 0)
1692 EXPORT_SYMBOL_GPL(clk_has_parent);
1694 static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent)
1698 unsigned long p_rate = 0;
1703 /* prevent racing with updates to the clock topology */
1706 if (core->parent == parent)
1709 /* verify ops for for multi-parent clks */
1710 if ((core->num_parents > 1) && (!core->ops->set_parent)) {
1715 /* check that we are allowed to re-parent if the clock is in use */
1716 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1721 /* try finding the new parent index */
1723 p_index = clk_fetch_parent_index(core, parent);
1724 p_rate = parent->rate;
1726 pr_debug("%s: clk %s can not be parent of clk %s\n",
1727 __func__, parent->name, core->name);
1733 /* propagate PRE_RATE_CHANGE notifications */
1734 ret = __clk_speculate_rates(core, p_rate);
1736 /* abort if a driver objects */
1737 if (ret & NOTIFY_STOP_MASK)
1740 /* do the re-parent */
1741 ret = __clk_set_parent(core, parent, p_index);
1743 /* propagate rate an accuracy recalculation accordingly */
1745 __clk_recalc_rates(core, ABORT_RATE_CHANGE);
1747 __clk_recalc_rates(core, POST_RATE_CHANGE);
1748 __clk_recalc_accuracies(core);
1752 clk_prepare_unlock();
1758 * clk_set_parent - switch the parent of a mux clk
1759 * @clk: the mux clk whose input we are switching
1760 * @parent: the new input to clk
1762 * Re-parent clk to use parent as its new input source. If clk is in
1763 * prepared state, the clk will get enabled for the duration of this call. If
1764 * that's not acceptable for a specific clk (Eg: the consumer can't handle
1765 * that, the reparenting is glitchy in hardware, etc), use the
1766 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
1768 * After successfully changing clk's parent clk_set_parent will update the
1769 * clk topology, sysfs topology and propagate rate recalculation via
1770 * __clk_recalc_rates.
1772 * Returns 0 on success, -EERROR otherwise.
1774 int clk_set_parent(struct clk *clk, struct clk *parent)
1779 return clk_core_set_parent(clk->core, parent ? parent->core : NULL);
1781 EXPORT_SYMBOL_GPL(clk_set_parent);
1784 * clk_set_phase - adjust the phase shift of a clock signal
1785 * @clk: clock signal source
1786 * @degrees: number of degrees the signal is shifted
1788 * Shifts the phase of a clock signal by the specified
1789 * degrees. Returns 0 on success, -EERROR otherwise.
1791 * This function makes no distinction about the input or reference
1792 * signal that we adjust the clock signal phase against. For example
1793 * phase locked-loop clock signal generators we may shift phase with
1794 * respect to feedback clock signal input, but for other cases the
1795 * clock phase may be shifted with respect to some other, unspecified
1798 * Additionally the concept of phase shift does not propagate through
1799 * the clock tree hierarchy, which sets it apart from clock rates and
1800 * clock accuracy. A parent clock phase attribute does not have an
1801 * impact on the phase attribute of a child clock.
1803 int clk_set_phase(struct clk *clk, int degrees)
1810 /* sanity check degrees */
1817 trace_clk_set_phase(clk->core, degrees);
1819 if (clk->core->ops->set_phase)
1820 ret = clk->core->ops->set_phase(clk->core->hw, degrees);
1822 trace_clk_set_phase_complete(clk->core, degrees);
1825 clk->core->phase = degrees;
1827 clk_prepare_unlock();
1831 EXPORT_SYMBOL_GPL(clk_set_phase);
1833 static int clk_core_get_phase(struct clk_core *core)
1839 clk_prepare_unlock();
1845 * clk_get_phase - return the phase shift of a clock signal
1846 * @clk: clock signal source
1848 * Returns the phase shift of a clock node in degrees, otherwise returns
1851 int clk_get_phase(struct clk *clk)
1856 return clk_core_get_phase(clk->core);
1858 EXPORT_SYMBOL_GPL(clk_get_phase);
1861 * clk_is_match - check if two clk's point to the same hardware clock
1862 * @p: clk compared against q
1863 * @q: clk compared against p
1865 * Returns true if the two struct clk pointers both point to the same hardware
1866 * clock node. Put differently, returns true if struct clk *p and struct clk *q
1867 * share the same struct clk_core object.
1869 * Returns false otherwise. Note that two NULL clks are treated as matching.
1871 bool clk_is_match(const struct clk *p, const struct clk *q)
1873 /* trivial case: identical struct clk's or both NULL */
1877 /* true if clk->core pointers match. Avoid derefing garbage */
1878 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
1879 if (p->core == q->core)
1884 EXPORT_SYMBOL_GPL(clk_is_match);
1886 /*** debugfs support ***/
1888 #ifdef CONFIG_DEBUG_FS
1889 #include <linux/debugfs.h>
1891 static struct dentry *rootdir;
1892 static int inited = 0;
1893 static DEFINE_MUTEX(clk_debug_lock);
1894 static HLIST_HEAD(clk_debug_list);
1896 static struct hlist_head *all_lists[] = {
1902 static struct hlist_head *orphan_list[] = {
1907 static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
1913 seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu %-3d\n",
1915 30 - level * 3, c->name,
1916 c->enable_count, c->prepare_count, clk_core_get_rate(c),
1917 clk_core_get_accuracy(c), clk_core_get_phase(c));
1920 static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
1923 struct clk_core *child;
1928 clk_summary_show_one(s, c, level);
1930 hlist_for_each_entry(child, &c->children, child_node)
1931 clk_summary_show_subtree(s, child, level + 1);
1934 static int clk_summary_show(struct seq_file *s, void *data)
1937 struct hlist_head **lists = (struct hlist_head **)s->private;
1939 seq_puts(s, " clock enable_cnt prepare_cnt rate accuracy phase\n");
1940 seq_puts(s, "----------------------------------------------------------------------------------------\n");
1944 for (; *lists; lists++)
1945 hlist_for_each_entry(c, *lists, child_node)
1946 clk_summary_show_subtree(s, c, 0);
1948 clk_prepare_unlock();
1954 static int clk_summary_open(struct inode *inode, struct file *file)
1956 return single_open(file, clk_summary_show, inode->i_private);
1959 static const struct file_operations clk_summary_fops = {
1960 .open = clk_summary_open,
1962 .llseek = seq_lseek,
1963 .release = single_release,
1966 static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
1971 /* This should be JSON format, i.e. elements separated with a comma */
1972 seq_printf(s, "\"%s\": { ", c->name);
1973 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
1974 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
1975 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate(c));
1976 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c));
1977 seq_printf(s, "\"phase\": %d", clk_core_get_phase(c));
1980 static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
1982 struct clk_core *child;
1987 clk_dump_one(s, c, level);
1989 hlist_for_each_entry(child, &c->children, child_node) {
1991 clk_dump_subtree(s, child, level + 1);
1997 static int clk_dump(struct seq_file *s, void *data)
2000 bool first_node = true;
2001 struct hlist_head **lists = (struct hlist_head **)s->private;
2007 for (; *lists; lists++) {
2008 hlist_for_each_entry(c, *lists, child_node) {
2012 clk_dump_subtree(s, c, 0);
2016 clk_prepare_unlock();
2023 static int clk_dump_open(struct inode *inode, struct file *file)
2025 return single_open(file, clk_dump, inode->i_private);
2028 static const struct file_operations clk_dump_fops = {
2029 .open = clk_dump_open,
2031 .llseek = seq_lseek,
2032 .release = single_release,
2035 static int clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
2040 if (!core || !pdentry) {
2045 d = debugfs_create_dir(core->name, pdentry);
2051 d = debugfs_create_u32("clk_rate", S_IRUGO, core->dentry,
2052 (u32 *)&core->rate);
2056 d = debugfs_create_u32("clk_accuracy", S_IRUGO, core->dentry,
2057 (u32 *)&core->accuracy);
2061 d = debugfs_create_u32("clk_phase", S_IRUGO, core->dentry,
2062 (u32 *)&core->phase);
2066 d = debugfs_create_x32("clk_flags", S_IRUGO, core->dentry,
2067 (u32 *)&core->flags);
2071 d = debugfs_create_u32("clk_prepare_count", S_IRUGO, core->dentry,
2072 (u32 *)&core->prepare_count);
2076 d = debugfs_create_u32("clk_enable_count", S_IRUGO, core->dentry,
2077 (u32 *)&core->enable_count);
2081 d = debugfs_create_u32("clk_notifier_count", S_IRUGO, core->dentry,
2082 (u32 *)&core->notifier_count);
2086 if (core->ops->debug_init) {
2087 ret = core->ops->debug_init(core->hw, core->dentry);
2096 debugfs_remove_recursive(core->dentry);
2097 core->dentry = NULL;
2103 * clk_debug_register - add a clk node to the debugfs clk directory
2104 * @core: the clk being added to the debugfs clk directory
2106 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
2107 * initialized. Otherwise it bails out early since the debugfs clk directory
2108 * will be created lazily by clk_debug_init as part of a late_initcall.
2110 static int clk_debug_register(struct clk_core *core)
2114 mutex_lock(&clk_debug_lock);
2115 hlist_add_head(&core->debug_node, &clk_debug_list);
2120 ret = clk_debug_create_one(core, rootdir);
2122 mutex_unlock(&clk_debug_lock);
2128 * clk_debug_unregister - remove a clk node from the debugfs clk directory
2129 * @core: the clk being removed from the debugfs clk directory
2131 * Dynamically removes a clk and all its child nodes from the
2132 * debugfs clk directory if clk->dentry points to debugfs created by
2133 * clk_debug_register in __clk_init.
2135 static void clk_debug_unregister(struct clk_core *core)
2137 mutex_lock(&clk_debug_lock);
2138 hlist_del_init(&core->debug_node);
2139 debugfs_remove_recursive(core->dentry);
2140 core->dentry = NULL;
2141 mutex_unlock(&clk_debug_lock);
2144 struct dentry *clk_debugfs_add_file(struct clk_hw *hw, char *name, umode_t mode,
2145 void *data, const struct file_operations *fops)
2147 struct dentry *d = NULL;
2149 if (hw->core->dentry)
2150 d = debugfs_create_file(name, mode, hw->core->dentry, data,
2155 EXPORT_SYMBOL_GPL(clk_debugfs_add_file);
2158 * clk_debug_init - lazily populate the debugfs clk directory
2160 * clks are often initialized very early during boot before memory can be
2161 * dynamically allocated and well before debugfs is setup. This function
2162 * populates the debugfs clk directory once at boot-time when we know that
2163 * debugfs is setup. It should only be called once at boot-time, all other clks
2164 * added dynamically will be done so with clk_debug_register.
2166 static int __init clk_debug_init(void)
2168 struct clk_core *core;
2171 rootdir = debugfs_create_dir("clk", NULL);
2176 d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists,
2181 d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists,
2186 d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir,
2187 &orphan_list, &clk_summary_fops);
2191 d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir,
2192 &orphan_list, &clk_dump_fops);
2196 mutex_lock(&clk_debug_lock);
2197 hlist_for_each_entry(core, &clk_debug_list, debug_node)
2198 clk_debug_create_one(core, rootdir);
2201 mutex_unlock(&clk_debug_lock);
2205 late_initcall(clk_debug_init);
2207 static inline int clk_debug_register(struct clk_core *core) { return 0; }
2208 static inline void clk_debug_reparent(struct clk_core *core,
2209 struct clk_core *new_parent)
2212 static inline void clk_debug_unregister(struct clk_core *core)
2218 * __clk_init - initialize the data structures in a struct clk
2219 * @dev: device initializing this clk, placeholder for now
2220 * @clk: clk being initialized
2222 * Initializes the lists in struct clk_core, queries the hardware for the
2223 * parent and rate and sets them both.
2225 static int __clk_init(struct device *dev, struct clk *clk_user)
2228 struct clk_core *orphan;
2229 struct hlist_node *tmp2;
2230 struct clk_core *core;
2236 core = clk_user->core;
2240 /* check to see if a clock with this name is already registered */
2241 if (clk_core_lookup(core->name)) {
2242 pr_debug("%s: clk %s already initialized\n",
2243 __func__, core->name);
2248 /* check that clk_ops are sane. See Documentation/clk.txt */
2249 if (core->ops->set_rate &&
2250 !((core->ops->round_rate || core->ops->determine_rate) &&
2251 core->ops->recalc_rate)) {
2252 pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
2253 __func__, core->name);
2258 if (core->ops->set_parent && !core->ops->get_parent) {
2259 pr_warning("%s: %s must implement .get_parent & .set_parent\n",
2260 __func__, core->name);
2265 if (core->ops->set_rate_and_parent &&
2266 !(core->ops->set_parent && core->ops->set_rate)) {
2267 pr_warn("%s: %s must implement .set_parent & .set_rate\n",
2268 __func__, core->name);
2273 /* throw a WARN if any entries in parent_names are NULL */
2274 for (i = 0; i < core->num_parents; i++)
2275 WARN(!core->parent_names[i],
2276 "%s: invalid NULL in %s's .parent_names\n",
2277 __func__, core->name);
2280 * Allocate an array of struct clk *'s to avoid unnecessary string
2281 * look-ups of clk's possible parents. This can fail for clocks passed
2282 * in to clk_init during early boot; thus any access to core->parents[]
2283 * must always check for a NULL pointer and try to populate it if
2286 * If core->parents is not NULL we skip this entire block. This allows
2287 * for clock drivers to statically initialize core->parents.
2289 if (core->num_parents > 1 && !core->parents) {
2290 core->parents = kcalloc(core->num_parents, sizeof(struct clk *),
2293 * clk_core_lookup returns NULL for parents that have not been
2294 * clk_init'd; thus any access to clk->parents[] must check
2295 * for a NULL pointer. We can always perform lazy lookups for
2296 * missing parents later on.
2299 for (i = 0; i < core->num_parents; i++)
2301 clk_core_lookup(core->parent_names[i]);
2304 core->parent = __clk_init_parent(core);
2307 * Populate core->parent if parent has already been __clk_init'd. If
2308 * parent has not yet been __clk_init'd then place clk in the orphan
2309 * list. If clk has set the CLK_IS_ROOT flag then place it in the root
2312 * Every time a new clk is clk_init'd then we walk the list of orphan
2313 * clocks and re-parent any that are children of the clock currently
2317 hlist_add_head(&core->child_node,
2318 &core->parent->children);
2319 else if (core->flags & CLK_IS_ROOT)
2320 hlist_add_head(&core->child_node, &clk_root_list);
2322 hlist_add_head(&core->child_node, &clk_orphan_list);
2325 * Set clk's accuracy. The preferred method is to use
2326 * .recalc_accuracy. For simple clocks and lazy developers the default
2327 * fallback is to use the parent's accuracy. If a clock doesn't have a
2328 * parent (or is orphaned) then accuracy is set to zero (perfect
2331 if (core->ops->recalc_accuracy)
2332 core->accuracy = core->ops->recalc_accuracy(core->hw,
2333 __clk_get_accuracy(core->parent));
2334 else if (core->parent)
2335 core->accuracy = core->parent->accuracy;
2341 * Since a phase is by definition relative to its parent, just
2342 * query the current clock phase, or just assume it's in phase.
2344 if (core->ops->get_phase)
2345 core->phase = core->ops->get_phase(core->hw);
2350 * Set clk's rate. The preferred method is to use .recalc_rate. For
2351 * simple clocks and lazy developers the default fallback is to use the
2352 * parent's rate. If a clock doesn't have a parent (or is orphaned)
2353 * then rate is set to zero.
2355 if (core->ops->recalc_rate)
2356 rate = core->ops->recalc_rate(core->hw,
2357 clk_core_get_rate_nolock(core->parent));
2358 else if (core->parent)
2359 rate = core->parent->rate;
2362 core->rate = core->req_rate = rate;
2365 * walk the list of orphan clocks and reparent any that are children of
2368 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
2369 if (orphan->num_parents && orphan->ops->get_parent) {
2370 i = orphan->ops->get_parent(orphan->hw);
2371 if (!strcmp(core->name, orphan->parent_names[i]))
2372 clk_core_reparent(orphan, core);
2376 for (i = 0; i < orphan->num_parents; i++)
2377 if (!strcmp(core->name, orphan->parent_names[i])) {
2378 clk_core_reparent(orphan, core);
2384 * optional platform-specific magic
2386 * The .init callback is not used by any of the basic clock types, but
2387 * exists for weird hardware that must perform initialization magic.
2388 * Please consider other ways of solving initialization problems before
2389 * using this callback, as its use is discouraged.
2391 if (core->ops->init)
2392 core->ops->init(core->hw);
2394 kref_init(&core->ref);
2396 clk_prepare_unlock();
2399 clk_debug_register(core);
2404 struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,
2409 /* This is to allow this function to be chained to others */
2410 if (!hw || IS_ERR(hw))
2411 return (struct clk *) hw;
2413 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
2415 return ERR_PTR(-ENOMEM);
2417 clk->core = hw->core;
2418 clk->dev_id = dev_id;
2419 clk->con_id = con_id;
2420 clk->max_rate = ULONG_MAX;
2423 hlist_add_head(&clk->clks_node, &hw->core->clks);
2424 clk_prepare_unlock();
2429 void __clk_free_clk(struct clk *clk)
2432 hlist_del(&clk->clks_node);
2433 clk_prepare_unlock();
2439 * clk_register - allocate a new clock, register it and return an opaque cookie
2440 * @dev: device that is registering this clock
2441 * @hw: link to hardware-specific clock data
2443 * clk_register is the primary interface for populating the clock tree with new
2444 * clock nodes. It returns a pointer to the newly allocated struct clk which
2445 * cannot be dereferenced by driver code but may be used in conjunction with the
2446 * rest of the clock API. In the event of an error clk_register will return an
2447 * error code; drivers must test for an error code after calling clk_register.
2449 struct clk *clk_register(struct device *dev, struct clk_hw *hw)
2452 struct clk_core *core;
2454 core = kzalloc(sizeof(*core), GFP_KERNEL);
2460 core->name = kstrdup_const(hw->init->name, GFP_KERNEL);
2465 core->ops = hw->init->ops;
2466 if (dev && dev->driver)
2467 core->owner = dev->driver->owner;
2469 core->flags = hw->init->flags;
2470 core->num_parents = hw->init->num_parents;
2473 /* allocate local copy in case parent_names is __initdata */
2474 core->parent_names = kcalloc(core->num_parents, sizeof(char *),
2477 if (!core->parent_names) {
2479 goto fail_parent_names;
2483 /* copy each string name in case parent_names is __initdata */
2484 for (i = 0; i < core->num_parents; i++) {
2485 core->parent_names[i] = kstrdup_const(hw->init->parent_names[i],
2487 if (!core->parent_names[i]) {
2489 goto fail_parent_names_copy;
2493 INIT_HLIST_HEAD(&core->clks);
2495 hw->clk = __clk_create_clk(hw, NULL, NULL);
2496 if (IS_ERR(hw->clk)) {
2497 ret = PTR_ERR(hw->clk);
2498 goto fail_parent_names_copy;
2501 ret = __clk_init(dev, hw->clk);
2505 __clk_free_clk(hw->clk);
2508 fail_parent_names_copy:
2510 kfree_const(core->parent_names[i]);
2511 kfree(core->parent_names);
2513 kfree_const(core->name);
2517 return ERR_PTR(ret);
2519 EXPORT_SYMBOL_GPL(clk_register);
2521 /* Free memory allocated for a clock. */
2522 static void __clk_release(struct kref *ref)
2524 struct clk_core *core = container_of(ref, struct clk_core, ref);
2525 int i = core->num_parents;
2527 lockdep_assert_held(&prepare_lock);
2529 kfree(core->parents);
2531 kfree_const(core->parent_names[i]);
2533 kfree(core->parent_names);
2534 kfree_const(core->name);
2539 * Empty clk_ops for unregistered clocks. These are used temporarily
2540 * after clk_unregister() was called on a clock and until last clock
2541 * consumer calls clk_put() and the struct clk object is freed.
2543 static int clk_nodrv_prepare_enable(struct clk_hw *hw)
2548 static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
2553 static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
2554 unsigned long parent_rate)
2559 static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
2564 static const struct clk_ops clk_nodrv_ops = {
2565 .enable = clk_nodrv_prepare_enable,
2566 .disable = clk_nodrv_disable_unprepare,
2567 .prepare = clk_nodrv_prepare_enable,
2568 .unprepare = clk_nodrv_disable_unprepare,
2569 .set_rate = clk_nodrv_set_rate,
2570 .set_parent = clk_nodrv_set_parent,
2574 * clk_unregister - unregister a currently registered clock
2575 * @clk: clock to unregister
2577 void clk_unregister(struct clk *clk)
2579 unsigned long flags;
2581 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2584 clk_debug_unregister(clk->core);
2588 if (clk->core->ops == &clk_nodrv_ops) {
2589 pr_err("%s: unregistered clock: %s\n", __func__,
2594 * Assign empty clock ops for consumers that might still hold
2595 * a reference to this clock.
2597 flags = clk_enable_lock();
2598 clk->core->ops = &clk_nodrv_ops;
2599 clk_enable_unlock(flags);
2601 if (!hlist_empty(&clk->core->children)) {
2602 struct clk_core *child;
2603 struct hlist_node *t;
2605 /* Reparent all children to the orphan list. */
2606 hlist_for_each_entry_safe(child, t, &clk->core->children,
2608 clk_core_set_parent(child, NULL);
2611 hlist_del_init(&clk->core->child_node);
2613 if (clk->core->prepare_count)
2614 pr_warn("%s: unregistering prepared clock: %s\n",
2615 __func__, clk->core->name);
2616 kref_put(&clk->core->ref, __clk_release);
2618 clk_prepare_unlock();
2620 EXPORT_SYMBOL_GPL(clk_unregister);
2622 static void devm_clk_release(struct device *dev, void *res)
2624 clk_unregister(*(struct clk **)res);
2628 * devm_clk_register - resource managed clk_register()
2629 * @dev: device that is registering this clock
2630 * @hw: link to hardware-specific clock data
2632 * Managed clk_register(). Clocks returned from this function are
2633 * automatically clk_unregister()ed on driver detach. See clk_register() for
2636 struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
2641 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
2643 return ERR_PTR(-ENOMEM);
2645 clk = clk_register(dev, hw);
2648 devres_add(dev, clkp);
2655 EXPORT_SYMBOL_GPL(devm_clk_register);
2657 static int devm_clk_match(struct device *dev, void *res, void *data)
2659 struct clk *c = res;
2666 * devm_clk_unregister - resource managed clk_unregister()
2667 * @clk: clock to unregister
2669 * Deallocate a clock allocated with devm_clk_register(). Normally
2670 * this function will not need to be called and the resource management
2671 * code will ensure that the resource is freed.
2673 void devm_clk_unregister(struct device *dev, struct clk *clk)
2675 WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
2677 EXPORT_SYMBOL_GPL(devm_clk_unregister);
2682 int __clk_get(struct clk *clk)
2684 struct clk_core *core = !clk ? NULL : clk->core;
2687 if (!try_module_get(core->owner))
2690 kref_get(&core->ref);
2695 void __clk_put(struct clk *clk)
2697 struct module *owner;
2699 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2704 hlist_del(&clk->clks_node);
2705 if (clk->min_rate > clk->core->req_rate ||
2706 clk->max_rate < clk->core->req_rate)
2707 clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
2709 owner = clk->core->owner;
2710 kref_put(&clk->core->ref, __clk_release);
2712 clk_prepare_unlock();
2719 /*** clk rate change notifiers ***/
2722 * clk_notifier_register - add a clk rate change notifier
2723 * @clk: struct clk * to watch
2724 * @nb: struct notifier_block * with callback info
2726 * Request notification when clk's rate changes. This uses an SRCU
2727 * notifier because we want it to block and notifier unregistrations are
2728 * uncommon. The callbacks associated with the notifier must not
2729 * re-enter into the clk framework by calling any top-level clk APIs;
2730 * this will cause a nested prepare_lock mutex.
2732 * In all notification cases cases (pre, post and abort rate change) the
2733 * original clock rate is passed to the callback via struct
2734 * clk_notifier_data.old_rate and the new frequency is passed via struct
2735 * clk_notifier_data.new_rate.
2737 * clk_notifier_register() must be called from non-atomic context.
2738 * Returns -EINVAL if called with null arguments, -ENOMEM upon
2739 * allocation failure; otherwise, passes along the return value of
2740 * srcu_notifier_chain_register().
2742 int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
2744 struct clk_notifier *cn;
2752 /* search the list of notifiers for this clk */
2753 list_for_each_entry(cn, &clk_notifier_list, node)
2757 /* if clk wasn't in the notifier list, allocate new clk_notifier */
2758 if (cn->clk != clk) {
2759 cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL);
2764 srcu_init_notifier_head(&cn->notifier_head);
2766 list_add(&cn->node, &clk_notifier_list);
2769 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
2771 clk->core->notifier_count++;
2774 clk_prepare_unlock();
2778 EXPORT_SYMBOL_GPL(clk_notifier_register);
2781 * clk_notifier_unregister - remove a clk rate change notifier
2782 * @clk: struct clk *
2783 * @nb: struct notifier_block * with callback info
2785 * Request no further notification for changes to 'clk' and frees memory
2786 * allocated in clk_notifier_register.
2788 * Returns -EINVAL if called with null arguments; otherwise, passes
2789 * along the return value of srcu_notifier_chain_unregister().
2791 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
2793 struct clk_notifier *cn = NULL;
2801 list_for_each_entry(cn, &clk_notifier_list, node)
2805 if (cn->clk == clk) {
2806 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
2808 clk->core->notifier_count--;
2810 /* XXX the notifier code should handle this better */
2811 if (!cn->notifier_head.head) {
2812 srcu_cleanup_notifier_head(&cn->notifier_head);
2813 list_del(&cn->node);
2821 clk_prepare_unlock();
2825 EXPORT_SYMBOL_GPL(clk_notifier_unregister);
2829 * struct of_clk_provider - Clock provider registration structure
2830 * @link: Entry in global list of clock providers
2831 * @node: Pointer to device tree node of clock provider
2832 * @get: Get clock callback. Returns NULL or a struct clk for the
2833 * given clock specifier
2834 * @data: context pointer to be passed into @get callback
2836 struct of_clk_provider {
2837 struct list_head link;
2839 struct device_node *node;
2840 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
2844 static const struct of_device_id __clk_of_table_sentinel
2845 __used __section(__clk_of_table_end);
2847 static LIST_HEAD(of_clk_providers);
2848 static DEFINE_MUTEX(of_clk_mutex);
2850 struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
2855 EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
2857 struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
2859 struct clk_onecell_data *clk_data = data;
2860 unsigned int idx = clkspec->args[0];
2862 if (idx >= clk_data->clk_num) {
2863 pr_err("%s: invalid clock index %d\n", __func__, idx);
2864 return ERR_PTR(-EINVAL);
2867 return clk_data->clks[idx];
2869 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
2872 * of_clk_add_provider() - Register a clock provider for a node
2873 * @np: Device node pointer associated with clock provider
2874 * @clk_src_get: callback for decoding clock
2875 * @data: context pointer for @clk_src_get callback.
2877 int of_clk_add_provider(struct device_node *np,
2878 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
2882 struct of_clk_provider *cp;
2885 cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL);
2889 cp->node = of_node_get(np);
2891 cp->get = clk_src_get;
2893 mutex_lock(&of_clk_mutex);
2894 list_add(&cp->link, &of_clk_providers);
2895 mutex_unlock(&of_clk_mutex);
2896 pr_debug("Added clock from %s\n", np->full_name);
2898 ret = of_clk_set_defaults(np, true);
2900 of_clk_del_provider(np);
2904 EXPORT_SYMBOL_GPL(of_clk_add_provider);
2907 * of_clk_del_provider() - Remove a previously registered clock provider
2908 * @np: Device node pointer associated with clock provider
2910 void of_clk_del_provider(struct device_node *np)
2912 struct of_clk_provider *cp;
2914 mutex_lock(&of_clk_mutex);
2915 list_for_each_entry(cp, &of_clk_providers, link) {
2916 if (cp->node == np) {
2917 list_del(&cp->link);
2918 of_node_put(cp->node);
2923 mutex_unlock(&of_clk_mutex);
2925 EXPORT_SYMBOL_GPL(of_clk_del_provider);
2927 struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec,
2928 const char *dev_id, const char *con_id)
2930 struct of_clk_provider *provider;
2931 struct clk *clk = ERR_PTR(-EPROBE_DEFER);
2934 return ERR_PTR(-EINVAL);
2936 /* Check if we have such a provider in our array */
2937 mutex_lock(&of_clk_mutex);
2938 list_for_each_entry(provider, &of_clk_providers, link) {
2939 if (provider->node == clkspec->np)
2940 clk = provider->get(clkspec, provider->data);
2942 clk = __clk_create_clk(__clk_get_hw(clk), dev_id,
2945 if (!IS_ERR(clk) && !__clk_get(clk)) {
2946 __clk_free_clk(clk);
2947 clk = ERR_PTR(-ENOENT);
2953 mutex_unlock(&of_clk_mutex);
2959 * of_clk_get_from_provider() - Lookup a clock from a clock provider
2960 * @clkspec: pointer to a clock specifier data structure
2962 * This function looks up a struct clk from the registered list of clock
2963 * providers, an input is a clock specifier data structure as returned
2964 * from the of_parse_phandle_with_args() function call.
2966 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
2968 return __of_clk_get_from_provider(clkspec, NULL, __func__);
2971 int of_clk_get_parent_count(struct device_node *np)
2973 return of_count_phandle_with_args(np, "clocks", "#clock-cells");
2975 EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
2977 const char *of_clk_get_parent_name(struct device_node *np, int index)
2979 struct of_phandle_args clkspec;
2980 struct property *prop;
2981 const char *clk_name;
2990 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
2995 index = clkspec.args_count ? clkspec.args[0] : 0;
2998 /* if there is an indices property, use it to transfer the index
2999 * specified into an array offset for the clock-output-names property.
3001 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
3009 if (of_property_read_string_index(clkspec.np, "clock-output-names",
3012 clk_name = clkspec.np->name;
3014 of_node_put(clkspec.np);
3017 EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
3020 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
3022 * @np: Device node pointer associated with clock provider
3023 * @parents: pointer to char array that hold the parents' names
3024 * @size: size of the @parents array
3026 * Return: number of parents for the clock node.
3028 int of_clk_parent_fill(struct device_node *np, const char **parents,
3033 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
3038 EXPORT_SYMBOL_GPL(of_clk_parent_fill);
3040 struct clock_provider {
3041 of_clk_init_cb_t clk_init_cb;
3042 struct device_node *np;
3043 struct list_head node;
3046 static LIST_HEAD(clk_provider_list);
3049 * This function looks for a parent clock. If there is one, then it
3050 * checks that the provider for this parent clock was initialized, in
3051 * this case the parent clock will be ready.
3053 static int parent_ready(struct device_node *np)
3058 struct clk *clk = of_clk_get(np, i);
3060 /* this parent is ready we can check the next one */
3067 /* at least one parent is not ready, we exit now */
3068 if (PTR_ERR(clk) == -EPROBE_DEFER)
3072 * Here we make assumption that the device tree is
3073 * written correctly. So an error means that there is
3074 * no more parent. As we didn't exit yet, then the
3075 * previous parent are ready. If there is no clock
3076 * parent, no need to wait for them, then we can
3077 * consider their absence as being ready
3084 * of_clk_init() - Scan and init clock providers from the DT
3085 * @matches: array of compatible values and init functions for providers.
3087 * This function scans the device tree for matching clock providers
3088 * and calls their initialization functions. It also does it by trying
3089 * to follow the dependencies.
3091 void __init of_clk_init(const struct of_device_id *matches)
3093 const struct of_device_id *match;
3094 struct device_node *np;
3095 struct clock_provider *clk_provider, *next;
3100 matches = &__clk_of_table;
3102 /* First prepare the list of the clocks providers */
3103 for_each_matching_node_and_match(np, matches, &match) {
3104 struct clock_provider *parent =
3105 kzalloc(sizeof(struct clock_provider), GFP_KERNEL);
3107 parent->clk_init_cb = match->data;
3109 list_add_tail(&parent->node, &clk_provider_list);
3112 while (!list_empty(&clk_provider_list)) {
3113 is_init_done = false;
3114 list_for_each_entry_safe(clk_provider, next,
3115 &clk_provider_list, node) {
3116 if (force || parent_ready(clk_provider->np)) {
3118 clk_provider->clk_init_cb(clk_provider->np);
3119 of_clk_set_defaults(clk_provider->np, true);
3121 list_del(&clk_provider->node);
3122 kfree(clk_provider);
3123 is_init_done = true;
3128 * We didn't manage to initialize any of the
3129 * remaining providers during the last loop, so now we
3130 * initialize all the remaining ones unconditionally
3131 * in case the clock parent was not mandatory