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.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/sched.h>
25 #include <linux/clkdev.h>
29 static DEFINE_SPINLOCK(enable_lock);
30 static DEFINE_MUTEX(prepare_lock);
32 static struct task_struct *prepare_owner;
33 static struct task_struct *enable_owner;
35 static int prepare_refcnt;
36 static int enable_refcnt;
38 static HLIST_HEAD(clk_root_list);
39 static HLIST_HEAD(clk_orphan_list);
40 static LIST_HEAD(clk_notifier_list);
42 /*** private data structures ***/
46 const struct clk_ops *ops;
49 struct clk_core *parent;
50 const char **parent_names;
51 struct clk_core **parents;
55 unsigned long req_rate;
56 unsigned long new_rate;
57 struct clk_core *new_parent;
58 struct clk_core *new_child;
61 unsigned int enable_count;
62 unsigned int prepare_count;
63 unsigned long min_rate;
64 unsigned long max_rate;
65 unsigned long accuracy;
67 struct hlist_head children;
68 struct hlist_node child_node;
69 struct hlist_head clks;
70 unsigned int notifier_count;
71 #ifdef CONFIG_DEBUG_FS
72 struct dentry *dentry;
73 struct hlist_node debug_node;
78 #define CREATE_TRACE_POINTS
79 #include <trace/events/clk.h>
82 struct clk_core *core;
85 unsigned long min_rate;
86 unsigned long max_rate;
87 struct hlist_node clks_node;
91 static void clk_prepare_lock(void)
93 if (!mutex_trylock(&prepare_lock)) {
94 if (prepare_owner == current) {
98 mutex_lock(&prepare_lock);
100 WARN_ON_ONCE(prepare_owner != NULL);
101 WARN_ON_ONCE(prepare_refcnt != 0);
102 prepare_owner = current;
106 static void clk_prepare_unlock(void)
108 WARN_ON_ONCE(prepare_owner != current);
109 WARN_ON_ONCE(prepare_refcnt == 0);
111 if (--prepare_refcnt)
113 prepare_owner = NULL;
114 mutex_unlock(&prepare_lock);
117 static unsigned long clk_enable_lock(void)
118 __acquires(enable_lock)
122 if (!spin_trylock_irqsave(&enable_lock, flags)) {
123 if (enable_owner == current) {
125 __acquire(enable_lock);
128 spin_lock_irqsave(&enable_lock, flags);
130 WARN_ON_ONCE(enable_owner != NULL);
131 WARN_ON_ONCE(enable_refcnt != 0);
132 enable_owner = current;
137 static void clk_enable_unlock(unsigned long flags)
138 __releases(enable_lock)
140 WARN_ON_ONCE(enable_owner != current);
141 WARN_ON_ONCE(enable_refcnt == 0);
143 if (--enable_refcnt) {
144 __release(enable_lock);
148 spin_unlock_irqrestore(&enable_lock, flags);
151 static bool clk_core_is_prepared(struct clk_core *core)
154 * .is_prepared is optional for clocks that can prepare
155 * fall back to software usage counter if it is missing
157 if (!core->ops->is_prepared)
158 return core->prepare_count;
160 return core->ops->is_prepared(core->hw);
163 static bool clk_core_is_enabled(struct clk_core *core)
166 * .is_enabled is only mandatory for clocks that gate
167 * fall back to software usage counter if .is_enabled is missing
169 if (!core->ops->is_enabled)
170 return core->enable_count;
172 return core->ops->is_enabled(core->hw);
175 static void clk_unprepare_unused_subtree(struct clk_core *core)
177 struct clk_core *child;
179 lockdep_assert_held(&prepare_lock);
181 hlist_for_each_entry(child, &core->children, child_node)
182 clk_unprepare_unused_subtree(child);
184 if (core->prepare_count)
187 if (core->flags & CLK_IGNORE_UNUSED)
190 if (clk_core_is_prepared(core)) {
191 trace_clk_unprepare(core);
192 if (core->ops->unprepare_unused)
193 core->ops->unprepare_unused(core->hw);
194 else if (core->ops->unprepare)
195 core->ops->unprepare(core->hw);
196 trace_clk_unprepare_complete(core);
200 static void clk_disable_unused_subtree(struct clk_core *core)
202 struct clk_core *child;
205 lockdep_assert_held(&prepare_lock);
207 hlist_for_each_entry(child, &core->children, child_node)
208 clk_disable_unused_subtree(child);
210 flags = clk_enable_lock();
212 if (core->enable_count)
215 if (core->flags & CLK_IGNORE_UNUSED)
219 * some gate clocks have special needs during the disable-unused
220 * sequence. call .disable_unused if available, otherwise fall
223 if (clk_core_is_enabled(core)) {
224 trace_clk_disable(core);
225 if (core->ops->disable_unused)
226 core->ops->disable_unused(core->hw);
227 else if (core->ops->disable)
228 core->ops->disable(core->hw);
229 trace_clk_disable_complete(core);
233 clk_enable_unlock(flags);
236 static bool clk_ignore_unused;
237 static int __init clk_ignore_unused_setup(char *__unused)
239 clk_ignore_unused = true;
242 __setup("clk_ignore_unused", clk_ignore_unused_setup);
244 static int clk_disable_unused(void)
246 struct clk_core *core;
248 if (clk_ignore_unused) {
249 pr_warn("clk: Not disabling unused clocks\n");
255 hlist_for_each_entry(core, &clk_root_list, child_node)
256 clk_disable_unused_subtree(core);
258 hlist_for_each_entry(core, &clk_orphan_list, child_node)
259 clk_disable_unused_subtree(core);
261 hlist_for_each_entry(core, &clk_root_list, child_node)
262 clk_unprepare_unused_subtree(core);
264 hlist_for_each_entry(core, &clk_orphan_list, child_node)
265 clk_unprepare_unused_subtree(core);
267 clk_prepare_unlock();
271 late_initcall_sync(clk_disable_unused);
273 /*** helper functions ***/
275 const char *__clk_get_name(const struct clk *clk)
277 return !clk ? NULL : clk->core->name;
279 EXPORT_SYMBOL_GPL(__clk_get_name);
281 const char *clk_hw_get_name(const struct clk_hw *hw)
283 return hw->core->name;
285 EXPORT_SYMBOL_GPL(clk_hw_get_name);
287 struct clk_hw *__clk_get_hw(struct clk *clk)
289 return !clk ? NULL : clk->core->hw;
291 EXPORT_SYMBOL_GPL(__clk_get_hw);
293 unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
295 return hw->core->num_parents;
297 EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
299 struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
301 return hw->core->parent ? hw->core->parent->hw : NULL;
303 EXPORT_SYMBOL_GPL(clk_hw_get_parent);
305 static struct clk_core *__clk_lookup_subtree(const char *name,
306 struct clk_core *core)
308 struct clk_core *child;
309 struct clk_core *ret;
311 if (!strcmp(core->name, name))
314 hlist_for_each_entry(child, &core->children, child_node) {
315 ret = __clk_lookup_subtree(name, child);
323 static struct clk_core *clk_core_lookup(const char *name)
325 struct clk_core *root_clk;
326 struct clk_core *ret;
331 /* search the 'proper' clk tree first */
332 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
333 ret = __clk_lookup_subtree(name, root_clk);
338 /* if not found, then search the orphan tree */
339 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
340 ret = __clk_lookup_subtree(name, root_clk);
348 static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
351 if (!core || index >= core->num_parents)
353 else if (!core->parents)
354 return clk_core_lookup(core->parent_names[index]);
355 else if (!core->parents[index])
356 return core->parents[index] =
357 clk_core_lookup(core->parent_names[index]);
359 return core->parents[index];
363 clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
365 struct clk_core *parent;
367 parent = clk_core_get_parent_by_index(hw->core, index);
369 return !parent ? NULL : parent->hw;
371 EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
373 unsigned int __clk_get_enable_count(struct clk *clk)
375 return !clk ? 0 : clk->core->enable_count;
378 static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
389 if (core->flags & CLK_IS_ROOT)
399 unsigned long clk_hw_get_rate(const struct clk_hw *hw)
401 return clk_core_get_rate_nolock(hw->core);
403 EXPORT_SYMBOL_GPL(clk_hw_get_rate);
405 static unsigned long __clk_get_accuracy(struct clk_core *core)
410 return core->accuracy;
413 unsigned long __clk_get_flags(struct clk *clk)
415 return !clk ? 0 : clk->core->flags;
417 EXPORT_SYMBOL_GPL(__clk_get_flags);
419 unsigned long clk_hw_get_flags(const struct clk_hw *hw)
421 return hw->core->flags;
423 EXPORT_SYMBOL_GPL(clk_hw_get_flags);
425 bool clk_hw_is_prepared(const struct clk_hw *hw)
427 return clk_core_is_prepared(hw->core);
430 bool clk_hw_is_enabled(const struct clk_hw *hw)
432 return clk_core_is_enabled(hw->core);
435 bool __clk_is_enabled(struct clk *clk)
440 return clk_core_is_enabled(clk->core);
442 EXPORT_SYMBOL_GPL(__clk_is_enabled);
444 static bool mux_is_better_rate(unsigned long rate, unsigned long now,
445 unsigned long best, unsigned long flags)
447 if (flags & CLK_MUX_ROUND_CLOSEST)
448 return abs(now - rate) < abs(best - rate);
450 return now <= rate && now > best;
454 clk_mux_determine_rate_flags(struct clk_hw *hw, struct clk_rate_request *req,
457 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
458 int i, num_parents, ret;
459 unsigned long best = 0;
460 struct clk_rate_request parent_req = *req;
462 /* if NO_REPARENT flag set, pass through to current parent */
463 if (core->flags & CLK_SET_RATE_NO_REPARENT) {
464 parent = core->parent;
465 if (core->flags & CLK_SET_RATE_PARENT) {
466 ret = __clk_determine_rate(parent ? parent->hw : NULL,
471 best = parent_req.rate;
473 best = clk_core_get_rate_nolock(parent);
475 best = clk_core_get_rate_nolock(core);
481 /* find the parent that can provide the fastest rate <= rate */
482 num_parents = core->num_parents;
483 for (i = 0; i < num_parents; i++) {
484 parent = clk_core_get_parent_by_index(core, i);
488 if (core->flags & CLK_SET_RATE_PARENT) {
490 ret = __clk_determine_rate(parent->hw, &parent_req);
494 parent_req.rate = clk_core_get_rate_nolock(parent);
497 if (mux_is_better_rate(req->rate, parent_req.rate,
499 best_parent = parent;
500 best = parent_req.rate;
509 req->best_parent_hw = best_parent->hw;
510 req->best_parent_rate = best;
516 struct clk *__clk_lookup(const char *name)
518 struct clk_core *core = clk_core_lookup(name);
520 return !core ? NULL : core->hw->clk;
523 static void clk_core_get_boundaries(struct clk_core *core,
524 unsigned long *min_rate,
525 unsigned long *max_rate)
527 struct clk *clk_user;
529 *min_rate = core->min_rate;
530 *max_rate = core->max_rate;
532 hlist_for_each_entry(clk_user, &core->clks, clks_node)
533 *min_rate = max(*min_rate, clk_user->min_rate);
535 hlist_for_each_entry(clk_user, &core->clks, clks_node)
536 *max_rate = min(*max_rate, clk_user->max_rate);
539 void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
540 unsigned long max_rate)
542 hw->core->min_rate = min_rate;
543 hw->core->max_rate = max_rate;
545 EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
548 * Helper for finding best parent to provide a given frequency. This can be used
549 * directly as a determine_rate callback (e.g. for a mux), or from a more
550 * complex clock that may combine a mux with other operations.
552 int __clk_mux_determine_rate(struct clk_hw *hw,
553 struct clk_rate_request *req)
555 return clk_mux_determine_rate_flags(hw, req, 0);
557 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
559 int __clk_mux_determine_rate_closest(struct clk_hw *hw,
560 struct clk_rate_request *req)
562 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
564 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
568 static void clk_core_unprepare(struct clk_core *core)
570 lockdep_assert_held(&prepare_lock);
575 if (WARN_ON(core->prepare_count == 0))
578 if (--core->prepare_count > 0)
581 WARN_ON(core->enable_count > 0);
583 trace_clk_unprepare(core);
585 if (core->ops->unprepare)
586 core->ops->unprepare(core->hw);
588 trace_clk_unprepare_complete(core);
589 clk_core_unprepare(core->parent);
593 * clk_unprepare - undo preparation of a clock source
594 * @clk: the clk being unprepared
596 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
597 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
598 * if the operation may sleep. One example is a clk which is accessed over
599 * I2c. In the complex case a clk gate operation may require a fast and a slow
600 * part. It is this reason that clk_unprepare and clk_disable are not mutually
601 * exclusive. In fact clk_disable must be called before clk_unprepare.
603 void clk_unprepare(struct clk *clk)
605 if (IS_ERR_OR_NULL(clk))
609 clk_core_unprepare(clk->core);
610 clk_prepare_unlock();
612 EXPORT_SYMBOL_GPL(clk_unprepare);
614 static int clk_core_prepare(struct clk_core *core)
618 lockdep_assert_held(&prepare_lock);
623 if (core->prepare_count == 0) {
624 ret = clk_core_prepare(core->parent);
628 trace_clk_prepare(core);
630 if (core->ops->prepare)
631 ret = core->ops->prepare(core->hw);
633 trace_clk_prepare_complete(core);
636 clk_core_unprepare(core->parent);
641 core->prepare_count++;
647 * clk_prepare - prepare a clock source
648 * @clk: the clk being prepared
650 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
651 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
652 * operation may sleep. One example is a clk which is accessed over I2c. In
653 * the complex case a clk ungate operation may require a fast and a slow part.
654 * It is this reason that clk_prepare and clk_enable are not mutually
655 * exclusive. In fact clk_prepare must be called before clk_enable.
656 * Returns 0 on success, -EERROR otherwise.
658 int clk_prepare(struct clk *clk)
666 ret = clk_core_prepare(clk->core);
667 clk_prepare_unlock();
671 EXPORT_SYMBOL_GPL(clk_prepare);
673 static void clk_core_disable(struct clk_core *core)
675 lockdep_assert_held(&enable_lock);
680 if (WARN_ON(core->enable_count == 0))
683 if (--core->enable_count > 0)
686 trace_clk_disable(core);
688 if (core->ops->disable)
689 core->ops->disable(core->hw);
691 trace_clk_disable_complete(core);
693 clk_core_disable(core->parent);
697 * clk_disable - gate a clock
698 * @clk: the clk being gated
700 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
701 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
702 * clk if the operation is fast and will never sleep. One example is a
703 * SoC-internal clk which is controlled via simple register writes. In the
704 * complex case a clk gate operation may require a fast and a slow part. It is
705 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
706 * In fact clk_disable must be called before clk_unprepare.
708 void clk_disable(struct clk *clk)
712 if (IS_ERR_OR_NULL(clk))
715 flags = clk_enable_lock();
716 clk_core_disable(clk->core);
717 clk_enable_unlock(flags);
719 EXPORT_SYMBOL_GPL(clk_disable);
721 static int clk_core_enable(struct clk_core *core)
725 lockdep_assert_held(&enable_lock);
730 if (WARN_ON(core->prepare_count == 0))
733 if (core->enable_count == 0) {
734 ret = clk_core_enable(core->parent);
739 trace_clk_enable(core);
741 if (core->ops->enable)
742 ret = core->ops->enable(core->hw);
744 trace_clk_enable_complete(core);
747 clk_core_disable(core->parent);
752 core->enable_count++;
757 * clk_enable - ungate a clock
758 * @clk: the clk being ungated
760 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
761 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
762 * if the operation will never sleep. One example is a SoC-internal clk which
763 * is controlled via simple register writes. In the complex case a clk ungate
764 * operation may require a fast and a slow part. It is this reason that
765 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
766 * must be called before clk_enable. Returns 0 on success, -EERROR
769 int clk_enable(struct clk *clk)
777 flags = clk_enable_lock();
778 ret = clk_core_enable(clk->core);
779 clk_enable_unlock(flags);
783 EXPORT_SYMBOL_GPL(clk_enable);
785 static int clk_core_round_rate_nolock(struct clk_core *core,
786 struct clk_rate_request *req)
788 struct clk_core *parent;
791 lockdep_assert_held(&prepare_lock);
796 parent = core->parent;
798 req->best_parent_hw = parent->hw;
799 req->best_parent_rate = parent->rate;
801 req->best_parent_hw = NULL;
802 req->best_parent_rate = 0;
805 if (core->ops->determine_rate) {
806 return core->ops->determine_rate(core->hw, req);
807 } else if (core->ops->round_rate) {
808 rate = core->ops->round_rate(core->hw, req->rate,
809 &req->best_parent_rate);
814 } else if (core->flags & CLK_SET_RATE_PARENT) {
815 return clk_core_round_rate_nolock(parent, req);
817 req->rate = core->rate;
824 * __clk_determine_rate - get the closest rate actually supported by a clock
825 * @hw: determine the rate of this clock
827 * @min_rate: returned rate must be greater than this rate
828 * @max_rate: returned rate must be less than this rate
830 * Useful for clk_ops such as .set_rate and .determine_rate.
832 int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
839 return clk_core_round_rate_nolock(hw->core, req);
841 EXPORT_SYMBOL_GPL(__clk_determine_rate);
843 unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
846 struct clk_rate_request req;
848 clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate);
851 ret = clk_core_round_rate_nolock(hw->core, &req);
857 EXPORT_SYMBOL_GPL(clk_hw_round_rate);
860 * clk_round_rate - round the given rate for a clk
861 * @clk: the clk for which we are rounding a rate
862 * @rate: the rate which is to be rounded
864 * Takes in a rate as input and rounds it to a rate that the clk can actually
865 * use which is then returned. If clk doesn't support round_rate operation
866 * then the parent rate is returned.
868 long clk_round_rate(struct clk *clk, unsigned long rate)
870 struct clk_rate_request req;
878 clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
881 ret = clk_core_round_rate_nolock(clk->core, &req);
882 clk_prepare_unlock();
889 EXPORT_SYMBOL_GPL(clk_round_rate);
892 * __clk_notify - call clk notifier chain
893 * @core: clk that is changing rate
894 * @msg: clk notifier type (see include/linux/clk.h)
895 * @old_rate: old clk rate
896 * @new_rate: new clk rate
898 * Triggers a notifier call chain on the clk rate-change notification
899 * for 'clk'. Passes a pointer to the struct clk and the previous
900 * and current rates to the notifier callback. Intended to be called by
901 * internal clock code only. Returns NOTIFY_DONE from the last driver
902 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
903 * a driver returns that.
905 static int __clk_notify(struct clk_core *core, unsigned long msg,
906 unsigned long old_rate, unsigned long new_rate)
908 struct clk_notifier *cn;
909 struct clk_notifier_data cnd;
910 int ret = NOTIFY_DONE;
912 cnd.old_rate = old_rate;
913 cnd.new_rate = new_rate;
915 list_for_each_entry(cn, &clk_notifier_list, node) {
916 if (cn->clk->core == core) {
918 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
927 * __clk_recalc_accuracies
928 * @core: first clk in the subtree
930 * Walks the subtree of clks starting with clk and recalculates accuracies as
931 * it goes. Note that if a clk does not implement the .recalc_accuracy
932 * callback then it is assumed that the clock will take on the accuracy of its
935 static void __clk_recalc_accuracies(struct clk_core *core)
937 unsigned long parent_accuracy = 0;
938 struct clk_core *child;
940 lockdep_assert_held(&prepare_lock);
943 parent_accuracy = core->parent->accuracy;
945 if (core->ops->recalc_accuracy)
946 core->accuracy = core->ops->recalc_accuracy(core->hw,
949 core->accuracy = parent_accuracy;
951 hlist_for_each_entry(child, &core->children, child_node)
952 __clk_recalc_accuracies(child);
955 static long clk_core_get_accuracy(struct clk_core *core)
957 unsigned long accuracy;
960 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
961 __clk_recalc_accuracies(core);
963 accuracy = __clk_get_accuracy(core);
964 clk_prepare_unlock();
970 * clk_get_accuracy - return the accuracy of clk
971 * @clk: the clk whose accuracy is being returned
973 * Simply returns the cached accuracy of the clk, unless
974 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
976 * If clk is NULL then returns 0.
978 long clk_get_accuracy(struct clk *clk)
983 return clk_core_get_accuracy(clk->core);
985 EXPORT_SYMBOL_GPL(clk_get_accuracy);
987 static unsigned long clk_recalc(struct clk_core *core,
988 unsigned long parent_rate)
990 if (core->ops->recalc_rate)
991 return core->ops->recalc_rate(core->hw, parent_rate);
997 * @core: first clk in the subtree
998 * @msg: notification type (see include/linux/clk.h)
1000 * Walks the subtree of clks starting with clk and recalculates rates as it
1001 * goes. Note that if a clk does not implement the .recalc_rate callback then
1002 * it is assumed that the clock will take on the rate of its parent.
1004 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1007 static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
1009 unsigned long old_rate;
1010 unsigned long parent_rate = 0;
1011 struct clk_core *child;
1013 lockdep_assert_held(&prepare_lock);
1015 old_rate = core->rate;
1018 parent_rate = core->parent->rate;
1020 core->rate = clk_recalc(core, parent_rate);
1023 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1024 * & ABORT_RATE_CHANGE notifiers
1026 if (core->notifier_count && msg)
1027 __clk_notify(core, msg, old_rate, core->rate);
1029 hlist_for_each_entry(child, &core->children, child_node)
1030 __clk_recalc_rates(child, msg);
1033 static unsigned long clk_core_get_rate(struct clk_core *core)
1039 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1040 __clk_recalc_rates(core, 0);
1042 rate = clk_core_get_rate_nolock(core);
1043 clk_prepare_unlock();
1049 * clk_get_rate - return the rate of clk
1050 * @clk: the clk whose rate is being returned
1052 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1053 * is set, which means a recalc_rate will be issued.
1054 * If clk is NULL then returns 0.
1056 unsigned long clk_get_rate(struct clk *clk)
1061 return clk_core_get_rate(clk->core);
1063 EXPORT_SYMBOL_GPL(clk_get_rate);
1065 static int clk_fetch_parent_index(struct clk_core *core,
1066 struct clk_core *parent)
1070 if (!core->parents) {
1071 core->parents = kcalloc(core->num_parents,
1072 sizeof(struct clk *), GFP_KERNEL);
1078 * find index of new parent clock using cached parent ptrs,
1079 * or if not yet cached, use string name comparison and cache
1080 * them now to avoid future calls to clk_core_lookup.
1082 for (i = 0; i < core->num_parents; i++) {
1083 if (core->parents[i] == parent)
1086 if (core->parents[i])
1089 if (!strcmp(core->parent_names[i], parent->name)) {
1090 core->parents[i] = clk_core_lookup(parent->name);
1099 * Update the orphan status of @core and all its children.
1101 static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
1103 struct clk_core *child;
1105 core->orphan = is_orphan;
1107 hlist_for_each_entry(child, &core->children, child_node)
1108 clk_core_update_orphan_status(child, is_orphan);
1111 static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1113 bool was_orphan = core->orphan;
1115 hlist_del(&core->child_node);
1118 bool becomes_orphan = new_parent->orphan;
1120 /* avoid duplicate POST_RATE_CHANGE notifications */
1121 if (new_parent->new_child == core)
1122 new_parent->new_child = NULL;
1124 hlist_add_head(&core->child_node, &new_parent->children);
1126 if (was_orphan != becomes_orphan)
1127 clk_core_update_orphan_status(core, becomes_orphan);
1129 hlist_add_head(&core->child_node, &clk_orphan_list);
1131 clk_core_update_orphan_status(core, true);
1134 core->parent = new_parent;
1137 static struct clk_core *__clk_set_parent_before(struct clk_core *core,
1138 struct clk_core *parent)
1140 unsigned long flags;
1141 struct clk_core *old_parent = core->parent;
1144 * Migrate prepare state between parents and prevent race with
1147 * If the clock is not prepared, then a race with
1148 * clk_enable/disable() is impossible since we already have the
1149 * prepare lock (future calls to clk_enable() need to be preceded by
1152 * If the clock is prepared, migrate the prepared state to the new
1153 * parent and also protect against a race with clk_enable() by
1154 * forcing the clock and the new parent on. This ensures that all
1155 * future calls to clk_enable() are practically NOPs with respect to
1156 * hardware and software states.
1158 * See also: Comment for clk_set_parent() below.
1160 if (core->prepare_count) {
1161 clk_core_prepare(parent);
1162 flags = clk_enable_lock();
1163 clk_core_enable(parent);
1164 clk_core_enable(core);
1165 clk_enable_unlock(flags);
1168 /* update the clk tree topology */
1169 flags = clk_enable_lock();
1170 clk_reparent(core, parent);
1171 clk_enable_unlock(flags);
1176 static void __clk_set_parent_after(struct clk_core *core,
1177 struct clk_core *parent,
1178 struct clk_core *old_parent)
1180 unsigned long flags;
1183 * Finish the migration of prepare state and undo the changes done
1184 * for preventing a race with clk_enable().
1186 if (core->prepare_count) {
1187 flags = clk_enable_lock();
1188 clk_core_disable(core);
1189 clk_core_disable(old_parent);
1190 clk_enable_unlock(flags);
1191 clk_core_unprepare(old_parent);
1195 static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
1198 unsigned long flags;
1200 struct clk_core *old_parent;
1202 old_parent = __clk_set_parent_before(core, parent);
1204 trace_clk_set_parent(core, parent);
1206 /* change clock input source */
1207 if (parent && core->ops->set_parent)
1208 ret = core->ops->set_parent(core->hw, p_index);
1210 trace_clk_set_parent_complete(core, parent);
1213 flags = clk_enable_lock();
1214 clk_reparent(core, old_parent);
1215 clk_enable_unlock(flags);
1216 __clk_set_parent_after(core, old_parent, parent);
1221 __clk_set_parent_after(core, parent, old_parent);
1227 * __clk_speculate_rates
1228 * @core: first clk in the subtree
1229 * @parent_rate: the "future" rate of clk's parent
1231 * Walks the subtree of clks starting with clk, speculating rates as it
1232 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1234 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1235 * pre-rate change notifications and returns early if no clks in the
1236 * subtree have subscribed to the notifications. Note that if a clk does not
1237 * implement the .recalc_rate callback then it is assumed that the clock will
1238 * take on the rate of its parent.
1240 static int __clk_speculate_rates(struct clk_core *core,
1241 unsigned long parent_rate)
1243 struct clk_core *child;
1244 unsigned long new_rate;
1245 int ret = NOTIFY_DONE;
1247 lockdep_assert_held(&prepare_lock);
1249 new_rate = clk_recalc(core, parent_rate);
1251 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1252 if (core->notifier_count)
1253 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
1255 if (ret & NOTIFY_STOP_MASK) {
1256 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1257 __func__, core->name, ret);
1261 hlist_for_each_entry(child, &core->children, child_node) {
1262 ret = __clk_speculate_rates(child, new_rate);
1263 if (ret & NOTIFY_STOP_MASK)
1271 static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
1272 struct clk_core *new_parent, u8 p_index)
1274 struct clk_core *child;
1276 core->new_rate = new_rate;
1277 core->new_parent = new_parent;
1278 core->new_parent_index = p_index;
1279 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1280 core->new_child = NULL;
1281 if (new_parent && new_parent != core->parent)
1282 new_parent->new_child = core;
1284 hlist_for_each_entry(child, &core->children, child_node) {
1285 child->new_rate = clk_recalc(child, new_rate);
1286 clk_calc_subtree(child, child->new_rate, NULL, 0);
1291 * calculate the new rates returning the topmost clock that has to be
1294 static struct clk_core *clk_calc_new_rates(struct clk_core *core,
1297 struct clk_core *top = core;
1298 struct clk_core *old_parent, *parent;
1299 unsigned long best_parent_rate = 0;
1300 unsigned long new_rate;
1301 unsigned long min_rate;
1302 unsigned long max_rate;
1307 if (IS_ERR_OR_NULL(core))
1310 /* save parent rate, if it exists */
1311 parent = old_parent = core->parent;
1313 best_parent_rate = parent->rate;
1315 clk_core_get_boundaries(core, &min_rate, &max_rate);
1317 /* find the closest rate and parent clk/rate */
1318 if (core->ops->determine_rate) {
1319 struct clk_rate_request req;
1322 req.min_rate = min_rate;
1323 req.max_rate = max_rate;
1325 req.best_parent_hw = parent->hw;
1326 req.best_parent_rate = parent->rate;
1328 req.best_parent_hw = NULL;
1329 req.best_parent_rate = 0;
1332 ret = core->ops->determine_rate(core->hw, &req);
1336 best_parent_rate = req.best_parent_rate;
1337 new_rate = req.rate;
1338 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
1339 } else if (core->ops->round_rate) {
1340 ret = core->ops->round_rate(core->hw, rate,
1346 if (new_rate < min_rate || new_rate > max_rate)
1348 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
1349 /* pass-through clock without adjustable parent */
1350 core->new_rate = core->rate;
1353 /* pass-through clock with adjustable parent */
1354 top = clk_calc_new_rates(parent, rate);
1355 new_rate = parent->new_rate;
1359 /* some clocks must be gated to change parent */
1360 if (parent != old_parent &&
1361 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1362 pr_debug("%s: %s not gated but wants to reparent\n",
1363 __func__, core->name);
1367 /* try finding the new parent index */
1368 if (parent && core->num_parents > 1) {
1369 p_index = clk_fetch_parent_index(core, parent);
1371 pr_debug("%s: clk %s can not be parent of clk %s\n",
1372 __func__, parent->name, core->name);
1377 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
1378 best_parent_rate != parent->rate)
1379 top = clk_calc_new_rates(parent, best_parent_rate);
1382 clk_calc_subtree(core, new_rate, parent, p_index);
1388 * Notify about rate changes in a subtree. Always walk down the whole tree
1389 * so that in case of an error we can walk down the whole tree again and
1392 static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
1393 unsigned long event)
1395 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
1396 int ret = NOTIFY_DONE;
1398 if (core->rate == core->new_rate)
1401 if (core->notifier_count) {
1402 ret = __clk_notify(core, event, core->rate, core->new_rate);
1403 if (ret & NOTIFY_STOP_MASK)
1407 hlist_for_each_entry(child, &core->children, child_node) {
1408 /* Skip children who will be reparented to another clock */
1409 if (child->new_parent && child->new_parent != core)
1411 tmp_clk = clk_propagate_rate_change(child, event);
1416 /* handle the new child who might not be in core->children yet */
1417 if (core->new_child) {
1418 tmp_clk = clk_propagate_rate_change(core->new_child, event);
1427 * walk down a subtree and set the new rates notifying the rate
1430 static void clk_change_rate(struct clk_core *core)
1432 struct clk_core *child;
1433 struct hlist_node *tmp;
1434 unsigned long old_rate;
1435 unsigned long best_parent_rate = 0;
1436 bool skip_set_rate = false;
1437 struct clk_core *old_parent;
1439 old_rate = core->rate;
1441 if (core->new_parent)
1442 best_parent_rate = core->new_parent->rate;
1443 else if (core->parent)
1444 best_parent_rate = core->parent->rate;
1446 if (core->new_parent && core->new_parent != core->parent) {
1447 old_parent = __clk_set_parent_before(core, core->new_parent);
1448 trace_clk_set_parent(core, core->new_parent);
1450 if (core->ops->set_rate_and_parent) {
1451 skip_set_rate = true;
1452 core->ops->set_rate_and_parent(core->hw, core->new_rate,
1454 core->new_parent_index);
1455 } else if (core->ops->set_parent) {
1456 core->ops->set_parent(core->hw, core->new_parent_index);
1459 trace_clk_set_parent_complete(core, core->new_parent);
1460 __clk_set_parent_after(core, core->new_parent, old_parent);
1463 trace_clk_set_rate(core, core->new_rate);
1465 if (!skip_set_rate && core->ops->set_rate)
1466 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
1468 trace_clk_set_rate_complete(core, core->new_rate);
1470 core->rate = clk_recalc(core, best_parent_rate);
1472 if (core->notifier_count && old_rate != core->rate)
1473 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
1475 if (core->flags & CLK_RECALC_NEW_RATES)
1476 (void)clk_calc_new_rates(core, core->new_rate);
1479 * Use safe iteration, as change_rate can actually swap parents
1480 * for certain clock types.
1482 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
1483 /* Skip children who will be reparented to another clock */
1484 if (child->new_parent && child->new_parent != core)
1486 clk_change_rate(child);
1489 /* handle the new child who might not be in core->children yet */
1490 if (core->new_child)
1491 clk_change_rate(core->new_child);
1494 static int clk_core_set_rate_nolock(struct clk_core *core,
1495 unsigned long req_rate)
1497 struct clk_core *top, *fail_clk;
1498 unsigned long rate = req_rate;
1504 /* bail early if nothing to do */
1505 if (rate == clk_core_get_rate_nolock(core))
1508 if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count)
1511 /* calculate new rates and get the topmost changed clock */
1512 top = clk_calc_new_rates(core, rate);
1516 /* notify that we are about to change rates */
1517 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
1519 pr_debug("%s: failed to set %s rate\n", __func__,
1521 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
1525 /* change the rates */
1526 clk_change_rate(top);
1528 core->req_rate = req_rate;
1534 * clk_set_rate - specify a new rate for clk
1535 * @clk: the clk whose rate is being changed
1536 * @rate: the new rate for clk
1538 * In the simplest case clk_set_rate will only adjust the rate of clk.
1540 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1541 * propagate up to clk's parent; whether or not this happens depends on the
1542 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1543 * after calling .round_rate then upstream parent propagation is ignored. If
1544 * *parent_rate comes back with a new rate for clk's parent then we propagate
1545 * up to clk's parent and set its rate. Upward propagation will continue
1546 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1547 * .round_rate stops requesting changes to clk's parent_rate.
1549 * Rate changes are accomplished via tree traversal that also recalculates the
1550 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
1552 * Returns 0 on success, -EERROR otherwise.
1554 int clk_set_rate(struct clk *clk, unsigned long rate)
1561 /* prevent racing with updates to the clock topology */
1564 ret = clk_core_set_rate_nolock(clk->core, rate);
1566 clk_prepare_unlock();
1570 EXPORT_SYMBOL_GPL(clk_set_rate);
1573 * clk_set_rate_range - set a rate range for a clock source
1574 * @clk: clock source
1575 * @min: desired minimum clock rate in Hz, inclusive
1576 * @max: desired maximum clock rate in Hz, inclusive
1578 * Returns success (0) or negative errno.
1580 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
1588 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
1589 __func__, clk->core->name, clk->dev_id, clk->con_id,
1596 if (min != clk->min_rate || max != clk->max_rate) {
1597 clk->min_rate = min;
1598 clk->max_rate = max;
1599 ret = clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
1602 clk_prepare_unlock();
1606 EXPORT_SYMBOL_GPL(clk_set_rate_range);
1609 * clk_set_min_rate - set a minimum clock rate for a clock source
1610 * @clk: clock source
1611 * @rate: desired minimum clock rate in Hz, inclusive
1613 * Returns success (0) or negative errno.
1615 int clk_set_min_rate(struct clk *clk, unsigned long rate)
1620 return clk_set_rate_range(clk, rate, clk->max_rate);
1622 EXPORT_SYMBOL_GPL(clk_set_min_rate);
1625 * clk_set_max_rate - set a maximum clock rate for a clock source
1626 * @clk: clock source
1627 * @rate: desired maximum clock rate in Hz, inclusive
1629 * Returns success (0) or negative errno.
1631 int clk_set_max_rate(struct clk *clk, unsigned long rate)
1636 return clk_set_rate_range(clk, clk->min_rate, rate);
1638 EXPORT_SYMBOL_GPL(clk_set_max_rate);
1641 * clk_get_parent - return the parent of a clk
1642 * @clk: the clk whose parent gets returned
1644 * Simply returns clk->parent. Returns NULL if clk is NULL.
1646 struct clk *clk_get_parent(struct clk *clk)
1654 /* TODO: Create a per-user clk and change callers to call clk_put */
1655 parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
1656 clk_prepare_unlock();
1660 EXPORT_SYMBOL_GPL(clk_get_parent);
1663 * .get_parent is mandatory for clocks with multiple possible parents. It is
1664 * optional for single-parent clocks. Always call .get_parent if it is
1665 * available and WARN if it is missing for multi-parent clocks.
1667 * For single-parent clocks without .get_parent, first check to see if the
1668 * .parents array exists, and if so use it to avoid an expensive tree
1669 * traversal. If .parents does not exist then walk the tree.
1671 static struct clk_core *__clk_init_parent(struct clk_core *core)
1673 struct clk_core *ret = NULL;
1676 /* handle the trivial cases */
1678 if (!core->num_parents)
1681 if (core->num_parents == 1) {
1682 if (IS_ERR_OR_NULL(core->parent))
1683 core->parent = clk_core_lookup(core->parent_names[0]);
1688 if (!core->ops->get_parent) {
1689 WARN(!core->ops->get_parent,
1690 "%s: multi-parent clocks must implement .get_parent\n",
1696 * Do our best to cache parent clocks in core->parents. This prevents
1697 * unnecessary and expensive lookups. We don't set core->parent here;
1698 * that is done by the calling function.
1701 index = core->ops->get_parent(core->hw);
1705 kcalloc(core->num_parents, sizeof(struct clk *),
1708 ret = clk_core_get_parent_by_index(core, index);
1714 static void clk_core_reparent(struct clk_core *core,
1715 struct clk_core *new_parent)
1717 clk_reparent(core, new_parent);
1718 __clk_recalc_accuracies(core);
1719 __clk_recalc_rates(core, POST_RATE_CHANGE);
1722 void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
1727 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
1731 * clk_has_parent - check if a clock is a possible parent for another
1732 * @clk: clock source
1733 * @parent: parent clock source
1735 * This function can be used in drivers that need to check that a clock can be
1736 * the parent of another without actually changing the parent.
1738 * Returns true if @parent is a possible parent for @clk, false otherwise.
1740 bool clk_has_parent(struct clk *clk, struct clk *parent)
1742 struct clk_core *core, *parent_core;
1745 /* NULL clocks should be nops, so return success if either is NULL. */
1746 if (!clk || !parent)
1750 parent_core = parent->core;
1752 /* Optimize for the case where the parent is already the parent. */
1753 if (core->parent == parent_core)
1756 for (i = 0; i < core->num_parents; i++)
1757 if (strcmp(core->parent_names[i], parent_core->name) == 0)
1762 EXPORT_SYMBOL_GPL(clk_has_parent);
1764 static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent)
1768 unsigned long p_rate = 0;
1773 /* prevent racing with updates to the clock topology */
1776 if (core->parent == parent)
1779 /* verify ops for for multi-parent clks */
1780 if ((core->num_parents > 1) && (!core->ops->set_parent)) {
1785 /* check that we are allowed to re-parent if the clock is in use */
1786 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1791 /* try finding the new parent index */
1793 p_index = clk_fetch_parent_index(core, parent);
1794 p_rate = parent->rate;
1796 pr_debug("%s: clk %s can not be parent of clk %s\n",
1797 __func__, parent->name, core->name);
1803 /* propagate PRE_RATE_CHANGE notifications */
1804 ret = __clk_speculate_rates(core, p_rate);
1806 /* abort if a driver objects */
1807 if (ret & NOTIFY_STOP_MASK)
1810 /* do the re-parent */
1811 ret = __clk_set_parent(core, parent, p_index);
1813 /* propagate rate an accuracy recalculation accordingly */
1815 __clk_recalc_rates(core, ABORT_RATE_CHANGE);
1817 __clk_recalc_rates(core, POST_RATE_CHANGE);
1818 __clk_recalc_accuracies(core);
1822 clk_prepare_unlock();
1828 * clk_set_parent - switch the parent of a mux clk
1829 * @clk: the mux clk whose input we are switching
1830 * @parent: the new input to clk
1832 * Re-parent clk to use parent as its new input source. If clk is in
1833 * prepared state, the clk will get enabled for the duration of this call. If
1834 * that's not acceptable for a specific clk (Eg: the consumer can't handle
1835 * that, the reparenting is glitchy in hardware, etc), use the
1836 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
1838 * After successfully changing clk's parent clk_set_parent will update the
1839 * clk topology, sysfs topology and propagate rate recalculation via
1840 * __clk_recalc_rates.
1842 * Returns 0 on success, -EERROR otherwise.
1844 int clk_set_parent(struct clk *clk, struct clk *parent)
1849 return clk_core_set_parent(clk->core, parent ? parent->core : NULL);
1851 EXPORT_SYMBOL_GPL(clk_set_parent);
1854 * clk_set_phase - adjust the phase shift of a clock signal
1855 * @clk: clock signal source
1856 * @degrees: number of degrees the signal is shifted
1858 * Shifts the phase of a clock signal by the specified
1859 * degrees. Returns 0 on success, -EERROR otherwise.
1861 * This function makes no distinction about the input or reference
1862 * signal that we adjust the clock signal phase against. For example
1863 * phase locked-loop clock signal generators we may shift phase with
1864 * respect to feedback clock signal input, but for other cases the
1865 * clock phase may be shifted with respect to some other, unspecified
1868 * Additionally the concept of phase shift does not propagate through
1869 * the clock tree hierarchy, which sets it apart from clock rates and
1870 * clock accuracy. A parent clock phase attribute does not have an
1871 * impact on the phase attribute of a child clock.
1873 int clk_set_phase(struct clk *clk, int degrees)
1880 /* sanity check degrees */
1887 trace_clk_set_phase(clk->core, degrees);
1889 if (clk->core->ops->set_phase)
1890 ret = clk->core->ops->set_phase(clk->core->hw, degrees);
1892 trace_clk_set_phase_complete(clk->core, degrees);
1895 clk->core->phase = degrees;
1897 clk_prepare_unlock();
1901 EXPORT_SYMBOL_GPL(clk_set_phase);
1903 static int clk_core_get_phase(struct clk_core *core)
1908 /* Always try to update cached phase if possible */
1909 if (core->ops->get_phase)
1910 core->phase = core->ops->get_phase(core->hw);
1912 clk_prepare_unlock();
1918 * clk_get_phase - return the phase shift of a clock signal
1919 * @clk: clock signal source
1921 * Returns the phase shift of a clock node in degrees, otherwise returns
1924 int clk_get_phase(struct clk *clk)
1929 return clk_core_get_phase(clk->core);
1931 EXPORT_SYMBOL_GPL(clk_get_phase);
1934 * clk_is_match - check if two clk's point to the same hardware clock
1935 * @p: clk compared against q
1936 * @q: clk compared against p
1938 * Returns true if the two struct clk pointers both point to the same hardware
1939 * clock node. Put differently, returns true if struct clk *p and struct clk *q
1940 * share the same struct clk_core object.
1942 * Returns false otherwise. Note that two NULL clks are treated as matching.
1944 bool clk_is_match(const struct clk *p, const struct clk *q)
1946 /* trivial case: identical struct clk's or both NULL */
1950 /* true if clk->core pointers match. Avoid derefing garbage */
1951 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
1952 if (p->core == q->core)
1957 EXPORT_SYMBOL_GPL(clk_is_match);
1959 /*** debugfs support ***/
1961 #ifdef CONFIG_DEBUG_FS
1962 #include <linux/debugfs.h>
1964 static struct dentry *rootdir;
1965 static int inited = 0;
1966 static DEFINE_MUTEX(clk_debug_lock);
1967 static HLIST_HEAD(clk_debug_list);
1969 static struct hlist_head *all_lists[] = {
1975 static struct hlist_head *orphan_list[] = {
1980 static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
1986 seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu %-3d\n",
1988 30 - level * 3, c->name,
1989 c->enable_count, c->prepare_count, clk_core_get_rate(c),
1990 clk_core_get_accuracy(c), clk_core_get_phase(c));
1993 static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
1996 struct clk_core *child;
2001 clk_summary_show_one(s, c, level);
2003 hlist_for_each_entry(child, &c->children, child_node)
2004 clk_summary_show_subtree(s, child, level + 1);
2007 static int clk_summary_show(struct seq_file *s, void *data)
2010 struct hlist_head **lists = (struct hlist_head **)s->private;
2012 seq_puts(s, " clock enable_cnt prepare_cnt rate accuracy phase\n");
2013 seq_puts(s, "----------------------------------------------------------------------------------------\n");
2017 for (; *lists; lists++)
2018 hlist_for_each_entry(c, *lists, child_node)
2019 clk_summary_show_subtree(s, c, 0);
2021 clk_prepare_unlock();
2027 static int clk_summary_open(struct inode *inode, struct file *file)
2029 return single_open(file, clk_summary_show, inode->i_private);
2032 static const struct file_operations clk_summary_fops = {
2033 .open = clk_summary_open,
2035 .llseek = seq_lseek,
2036 .release = single_release,
2039 static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
2044 /* This should be JSON format, i.e. elements separated with a comma */
2045 seq_printf(s, "\"%s\": { ", c->name);
2046 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
2047 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
2048 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate(c));
2049 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c));
2050 seq_printf(s, "\"phase\": %d", clk_core_get_phase(c));
2053 static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
2055 struct clk_core *child;
2060 clk_dump_one(s, c, level);
2062 hlist_for_each_entry(child, &c->children, child_node) {
2064 clk_dump_subtree(s, child, level + 1);
2070 static int clk_dump(struct seq_file *s, void *data)
2073 bool first_node = true;
2074 struct hlist_head **lists = (struct hlist_head **)s->private;
2080 for (; *lists; lists++) {
2081 hlist_for_each_entry(c, *lists, child_node) {
2085 clk_dump_subtree(s, c, 0);
2089 clk_prepare_unlock();
2096 static int clk_dump_open(struct inode *inode, struct file *file)
2098 return single_open(file, clk_dump, inode->i_private);
2101 static const struct file_operations clk_dump_fops = {
2102 .open = clk_dump_open,
2104 .llseek = seq_lseek,
2105 .release = single_release,
2108 static int clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
2113 if (!core || !pdentry) {
2118 d = debugfs_create_dir(core->name, pdentry);
2124 d = debugfs_create_u32("clk_rate", S_IRUGO, core->dentry,
2125 (u32 *)&core->rate);
2129 d = debugfs_create_u32("clk_accuracy", S_IRUGO, core->dentry,
2130 (u32 *)&core->accuracy);
2134 d = debugfs_create_u32("clk_phase", S_IRUGO, core->dentry,
2135 (u32 *)&core->phase);
2139 d = debugfs_create_x32("clk_flags", S_IRUGO, core->dentry,
2140 (u32 *)&core->flags);
2144 d = debugfs_create_u32("clk_prepare_count", S_IRUGO, core->dentry,
2145 (u32 *)&core->prepare_count);
2149 d = debugfs_create_u32("clk_enable_count", S_IRUGO, core->dentry,
2150 (u32 *)&core->enable_count);
2154 d = debugfs_create_u32("clk_notifier_count", S_IRUGO, core->dentry,
2155 (u32 *)&core->notifier_count);
2159 if (core->ops->debug_init) {
2160 ret = core->ops->debug_init(core->hw, core->dentry);
2169 debugfs_remove_recursive(core->dentry);
2170 core->dentry = NULL;
2176 * clk_debug_register - add a clk node to the debugfs clk directory
2177 * @core: the clk being added to the debugfs clk directory
2179 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
2180 * initialized. Otherwise it bails out early since the debugfs clk directory
2181 * will be created lazily by clk_debug_init as part of a late_initcall.
2183 static int clk_debug_register(struct clk_core *core)
2187 mutex_lock(&clk_debug_lock);
2188 hlist_add_head(&core->debug_node, &clk_debug_list);
2193 ret = clk_debug_create_one(core, rootdir);
2195 mutex_unlock(&clk_debug_lock);
2201 * clk_debug_unregister - remove a clk node from the debugfs clk directory
2202 * @core: the clk being removed from the debugfs clk directory
2204 * Dynamically removes a clk and all its child nodes from the
2205 * debugfs clk directory if clk->dentry points to debugfs created by
2206 * clk_debug_register in __clk_init.
2208 static void clk_debug_unregister(struct clk_core *core)
2210 mutex_lock(&clk_debug_lock);
2211 hlist_del_init(&core->debug_node);
2212 debugfs_remove_recursive(core->dentry);
2213 core->dentry = NULL;
2214 mutex_unlock(&clk_debug_lock);
2217 struct dentry *clk_debugfs_add_file(struct clk_hw *hw, char *name, umode_t mode,
2218 void *data, const struct file_operations *fops)
2220 struct dentry *d = NULL;
2222 if (hw->core->dentry)
2223 d = debugfs_create_file(name, mode, hw->core->dentry, data,
2228 EXPORT_SYMBOL_GPL(clk_debugfs_add_file);
2231 * clk_debug_init - lazily populate the debugfs clk directory
2233 * clks are often initialized very early during boot before memory can be
2234 * dynamically allocated and well before debugfs is setup. This function
2235 * populates the debugfs clk directory once at boot-time when we know that
2236 * debugfs is setup. It should only be called once at boot-time, all other clks
2237 * added dynamically will be done so with clk_debug_register.
2239 static int __init clk_debug_init(void)
2241 struct clk_core *core;
2244 rootdir = debugfs_create_dir("clk", NULL);
2249 d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists,
2254 d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists,
2259 d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir,
2260 &orphan_list, &clk_summary_fops);
2264 d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir,
2265 &orphan_list, &clk_dump_fops);
2269 mutex_lock(&clk_debug_lock);
2270 hlist_for_each_entry(core, &clk_debug_list, debug_node)
2271 clk_debug_create_one(core, rootdir);
2274 mutex_unlock(&clk_debug_lock);
2278 late_initcall(clk_debug_init);
2280 static inline int clk_debug_register(struct clk_core *core) { return 0; }
2281 static inline void clk_debug_reparent(struct clk_core *core,
2282 struct clk_core *new_parent)
2285 static inline void clk_debug_unregister(struct clk_core *core)
2291 * __clk_init - initialize the data structures in a struct clk
2292 * @dev: device initializing this clk, placeholder for now
2293 * @clk: clk being initialized
2295 * Initializes the lists in struct clk_core, queries the hardware for the
2296 * parent and rate and sets them both.
2298 static int __clk_init(struct device *dev, struct clk *clk_user)
2301 struct clk_core *orphan;
2302 struct hlist_node *tmp2;
2303 struct clk_core *core;
2309 core = clk_user->core;
2313 /* check to see if a clock with this name is already registered */
2314 if (clk_core_lookup(core->name)) {
2315 pr_debug("%s: clk %s already initialized\n",
2316 __func__, core->name);
2321 /* check that clk_ops are sane. See Documentation/clk.txt */
2322 if (core->ops->set_rate &&
2323 !((core->ops->round_rate || core->ops->determine_rate) &&
2324 core->ops->recalc_rate)) {
2325 pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
2326 __func__, core->name);
2331 if (core->ops->set_parent && !core->ops->get_parent) {
2332 pr_warning("%s: %s must implement .get_parent & .set_parent\n",
2333 __func__, core->name);
2338 if (core->ops->set_rate_and_parent &&
2339 !(core->ops->set_parent && core->ops->set_rate)) {
2340 pr_warn("%s: %s must implement .set_parent & .set_rate\n",
2341 __func__, core->name);
2346 /* throw a WARN if any entries in parent_names are NULL */
2347 for (i = 0; i < core->num_parents; i++)
2348 WARN(!core->parent_names[i],
2349 "%s: invalid NULL in %s's .parent_names\n",
2350 __func__, core->name);
2353 * Allocate an array of struct clk *'s to avoid unnecessary string
2354 * look-ups of clk's possible parents. This can fail for clocks passed
2355 * in to clk_init during early boot; thus any access to core->parents[]
2356 * must always check for a NULL pointer and try to populate it if
2359 * If core->parents is not NULL we skip this entire block. This allows
2360 * for clock drivers to statically initialize core->parents.
2362 if (core->num_parents > 1 && !core->parents) {
2363 core->parents = kcalloc(core->num_parents, sizeof(struct clk *),
2366 * clk_core_lookup returns NULL for parents that have not been
2367 * clk_init'd; thus any access to clk->parents[] must check
2368 * for a NULL pointer. We can always perform lazy lookups for
2369 * missing parents later on.
2372 for (i = 0; i < core->num_parents; i++)
2374 clk_core_lookup(core->parent_names[i]);
2377 core->parent = __clk_init_parent(core);
2380 * Populate core->parent if parent has already been __clk_init'd. If
2381 * parent has not yet been __clk_init'd then place clk in the orphan
2382 * list. If clk has set the CLK_IS_ROOT flag then place it in the root
2385 * Every time a new clk is clk_init'd then we walk the list of orphan
2386 * clocks and re-parent any that are children of the clock currently
2390 hlist_add_head(&core->child_node,
2391 &core->parent->children);
2392 core->orphan = core->parent->orphan;
2393 } else if (core->flags & CLK_IS_ROOT) {
2394 hlist_add_head(&core->child_node, &clk_root_list);
2395 core->orphan = false;
2397 hlist_add_head(&core->child_node, &clk_orphan_list);
2398 core->orphan = true;
2402 * Set clk's accuracy. The preferred method is to use
2403 * .recalc_accuracy. For simple clocks and lazy developers the default
2404 * fallback is to use the parent's accuracy. If a clock doesn't have a
2405 * parent (or is orphaned) then accuracy is set to zero (perfect
2408 if (core->ops->recalc_accuracy)
2409 core->accuracy = core->ops->recalc_accuracy(core->hw,
2410 __clk_get_accuracy(core->parent));
2411 else if (core->parent)
2412 core->accuracy = core->parent->accuracy;
2418 * Since a phase is by definition relative to its parent, just
2419 * query the current clock phase, or just assume it's in phase.
2421 if (core->ops->get_phase)
2422 core->phase = core->ops->get_phase(core->hw);
2427 * Set clk's rate. The preferred method is to use .recalc_rate. For
2428 * simple clocks and lazy developers the default fallback is to use the
2429 * parent's rate. If a clock doesn't have a parent (or is orphaned)
2430 * then rate is set to zero.
2432 if (core->ops->recalc_rate)
2433 rate = core->ops->recalc_rate(core->hw,
2434 clk_core_get_rate_nolock(core->parent));
2435 else if (core->parent)
2436 rate = core->parent->rate;
2439 core->rate = core->req_rate = rate;
2442 * walk the list of orphan clocks and reparent any that are children of
2445 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
2446 if (orphan->num_parents && orphan->ops->get_parent) {
2447 i = orphan->ops->get_parent(orphan->hw);
2448 if (i >= 0 && i < orphan->num_parents &&
2449 !strcmp(core->name, orphan->parent_names[i]))
2450 clk_core_reparent(orphan, core);
2454 for (i = 0; i < orphan->num_parents; i++)
2455 if (!strcmp(core->name, orphan->parent_names[i])) {
2456 clk_core_reparent(orphan, core);
2462 * optional platform-specific magic
2464 * The .init callback is not used by any of the basic clock types, but
2465 * exists for weird hardware that must perform initialization magic.
2466 * Please consider other ways of solving initialization problems before
2467 * using this callback, as its use is discouraged.
2469 if (core->ops->init)
2470 core->ops->init(core->hw);
2472 kref_init(&core->ref);
2474 clk_prepare_unlock();
2477 clk_debug_register(core);
2482 struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,
2487 /* This is to allow this function to be chained to others */
2488 if (!hw || IS_ERR(hw))
2489 return (struct clk *) hw;
2491 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
2493 return ERR_PTR(-ENOMEM);
2495 clk->core = hw->core;
2496 clk->dev_id = dev_id;
2497 clk->con_id = con_id;
2498 clk->max_rate = ULONG_MAX;
2501 hlist_add_head(&clk->clks_node, &hw->core->clks);
2502 clk_prepare_unlock();
2507 void __clk_free_clk(struct clk *clk)
2510 hlist_del(&clk->clks_node);
2511 clk_prepare_unlock();
2517 * clk_register - allocate a new clock, register it and return an opaque cookie
2518 * @dev: device that is registering this clock
2519 * @hw: link to hardware-specific clock data
2521 * clk_register is the primary interface for populating the clock tree with new
2522 * clock nodes. It returns a pointer to the newly allocated struct clk which
2523 * cannot be dereferenced by driver code but may be used in conjunction with the
2524 * rest of the clock API. In the event of an error clk_register will return an
2525 * error code; drivers must test for an error code after calling clk_register.
2527 struct clk *clk_register(struct device *dev, struct clk_hw *hw)
2530 struct clk_core *core;
2532 core = kzalloc(sizeof(*core), GFP_KERNEL);
2538 core->name = kstrdup_const(hw->init->name, GFP_KERNEL);
2543 core->ops = hw->init->ops;
2544 if (dev && dev->driver)
2545 core->owner = dev->driver->owner;
2547 core->flags = hw->init->flags;
2548 core->num_parents = hw->init->num_parents;
2550 core->max_rate = ULONG_MAX;
2553 /* allocate local copy in case parent_names is __initdata */
2554 core->parent_names = kcalloc(core->num_parents, sizeof(char *),
2557 if (!core->parent_names) {
2559 goto fail_parent_names;
2563 /* copy each string name in case parent_names is __initdata */
2564 for (i = 0; i < core->num_parents; i++) {
2565 core->parent_names[i] = kstrdup_const(hw->init->parent_names[i],
2567 if (!core->parent_names[i]) {
2569 goto fail_parent_names_copy;
2573 INIT_HLIST_HEAD(&core->clks);
2575 hw->clk = __clk_create_clk(hw, NULL, NULL);
2576 if (IS_ERR(hw->clk)) {
2577 ret = PTR_ERR(hw->clk);
2578 goto fail_parent_names_copy;
2581 ret = __clk_init(dev, hw->clk);
2585 __clk_free_clk(hw->clk);
2588 fail_parent_names_copy:
2590 kfree_const(core->parent_names[i]);
2591 kfree(core->parent_names);
2593 kfree_const(core->name);
2597 return ERR_PTR(ret);
2599 EXPORT_SYMBOL_GPL(clk_register);
2601 /* Free memory allocated for a clock. */
2602 static void __clk_release(struct kref *ref)
2604 struct clk_core *core = container_of(ref, struct clk_core, ref);
2605 int i = core->num_parents;
2607 lockdep_assert_held(&prepare_lock);
2609 kfree(core->parents);
2611 kfree_const(core->parent_names[i]);
2613 kfree(core->parent_names);
2614 kfree_const(core->name);
2619 * Empty clk_ops for unregistered clocks. These are used temporarily
2620 * after clk_unregister() was called on a clock and until last clock
2621 * consumer calls clk_put() and the struct clk object is freed.
2623 static int clk_nodrv_prepare_enable(struct clk_hw *hw)
2628 static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
2633 static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
2634 unsigned long parent_rate)
2639 static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
2644 static const struct clk_ops clk_nodrv_ops = {
2645 .enable = clk_nodrv_prepare_enable,
2646 .disable = clk_nodrv_disable_unprepare,
2647 .prepare = clk_nodrv_prepare_enable,
2648 .unprepare = clk_nodrv_disable_unprepare,
2649 .set_rate = clk_nodrv_set_rate,
2650 .set_parent = clk_nodrv_set_parent,
2654 * clk_unregister - unregister a currently registered clock
2655 * @clk: clock to unregister
2657 void clk_unregister(struct clk *clk)
2659 unsigned long flags;
2661 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2664 clk_debug_unregister(clk->core);
2668 if (clk->core->ops == &clk_nodrv_ops) {
2669 pr_err("%s: unregistered clock: %s\n", __func__,
2674 * Assign empty clock ops for consumers that might still hold
2675 * a reference to this clock.
2677 flags = clk_enable_lock();
2678 clk->core->ops = &clk_nodrv_ops;
2679 clk_enable_unlock(flags);
2681 if (!hlist_empty(&clk->core->children)) {
2682 struct clk_core *child;
2683 struct hlist_node *t;
2685 /* Reparent all children to the orphan list. */
2686 hlist_for_each_entry_safe(child, t, &clk->core->children,
2688 clk_core_set_parent(child, NULL);
2691 hlist_del_init(&clk->core->child_node);
2693 if (clk->core->prepare_count)
2694 pr_warn("%s: unregistering prepared clock: %s\n",
2695 __func__, clk->core->name);
2696 kref_put(&clk->core->ref, __clk_release);
2698 clk_prepare_unlock();
2700 EXPORT_SYMBOL_GPL(clk_unregister);
2702 static void devm_clk_release(struct device *dev, void *res)
2704 clk_unregister(*(struct clk **)res);
2708 * devm_clk_register - resource managed clk_register()
2709 * @dev: device that is registering this clock
2710 * @hw: link to hardware-specific clock data
2712 * Managed clk_register(). Clocks returned from this function are
2713 * automatically clk_unregister()ed on driver detach. See clk_register() for
2716 struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
2721 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
2723 return ERR_PTR(-ENOMEM);
2725 clk = clk_register(dev, hw);
2728 devres_add(dev, clkp);
2735 EXPORT_SYMBOL_GPL(devm_clk_register);
2737 static int devm_clk_match(struct device *dev, void *res, void *data)
2739 struct clk *c = res;
2746 * devm_clk_unregister - resource managed clk_unregister()
2747 * @clk: clock to unregister
2749 * Deallocate a clock allocated with devm_clk_register(). Normally
2750 * this function will not need to be called and the resource management
2751 * code will ensure that the resource is freed.
2753 void devm_clk_unregister(struct device *dev, struct clk *clk)
2755 WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
2757 EXPORT_SYMBOL_GPL(devm_clk_unregister);
2762 int __clk_get(struct clk *clk)
2764 struct clk_core *core = !clk ? NULL : clk->core;
2767 if (!try_module_get(core->owner))
2770 kref_get(&core->ref);
2775 void __clk_put(struct clk *clk)
2777 struct module *owner;
2779 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2784 hlist_del(&clk->clks_node);
2785 if (clk->min_rate > clk->core->req_rate ||
2786 clk->max_rate < clk->core->req_rate)
2787 clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
2789 owner = clk->core->owner;
2790 kref_put(&clk->core->ref, __clk_release);
2792 clk_prepare_unlock();
2799 /*** clk rate change notifiers ***/
2802 * clk_notifier_register - add a clk rate change notifier
2803 * @clk: struct clk * to watch
2804 * @nb: struct notifier_block * with callback info
2806 * Request notification when clk's rate changes. This uses an SRCU
2807 * notifier because we want it to block and notifier unregistrations are
2808 * uncommon. The callbacks associated with the notifier must not
2809 * re-enter into the clk framework by calling any top-level clk APIs;
2810 * this will cause a nested prepare_lock mutex.
2812 * In all notification cases cases (pre, post and abort rate change) the
2813 * original clock rate is passed to the callback via struct
2814 * clk_notifier_data.old_rate and the new frequency is passed via struct
2815 * clk_notifier_data.new_rate.
2817 * clk_notifier_register() must be called from non-atomic context.
2818 * Returns -EINVAL if called with null arguments, -ENOMEM upon
2819 * allocation failure; otherwise, passes along the return value of
2820 * srcu_notifier_chain_register().
2822 int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
2824 struct clk_notifier *cn;
2832 /* search the list of notifiers for this clk */
2833 list_for_each_entry(cn, &clk_notifier_list, node)
2837 /* if clk wasn't in the notifier list, allocate new clk_notifier */
2838 if (cn->clk != clk) {
2839 cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL);
2844 srcu_init_notifier_head(&cn->notifier_head);
2846 list_add(&cn->node, &clk_notifier_list);
2849 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
2851 clk->core->notifier_count++;
2854 clk_prepare_unlock();
2858 EXPORT_SYMBOL_GPL(clk_notifier_register);
2861 * clk_notifier_unregister - remove a clk rate change notifier
2862 * @clk: struct clk *
2863 * @nb: struct notifier_block * with callback info
2865 * Request no further notification for changes to 'clk' and frees memory
2866 * allocated in clk_notifier_register.
2868 * Returns -EINVAL if called with null arguments; otherwise, passes
2869 * along the return value of srcu_notifier_chain_unregister().
2871 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
2873 struct clk_notifier *cn;
2881 list_for_each_entry(cn, &clk_notifier_list, node) {
2882 if (cn->clk == clk) {
2883 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
2885 clk->core->notifier_count--;
2887 /* XXX the notifier code should handle this better */
2888 if (!cn->notifier_head.head) {
2889 srcu_cleanup_notifier_head(&cn->notifier_head);
2890 list_del(&cn->node);
2897 clk_prepare_unlock();
2901 EXPORT_SYMBOL_GPL(clk_notifier_unregister);
2905 * struct of_clk_provider - Clock provider registration structure
2906 * @link: Entry in global list of clock providers
2907 * @node: Pointer to device tree node of clock provider
2908 * @get: Get clock callback. Returns NULL or a struct clk for the
2909 * given clock specifier
2910 * @data: context pointer to be passed into @get callback
2912 struct of_clk_provider {
2913 struct list_head link;
2915 struct device_node *node;
2916 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
2920 static const struct of_device_id __clk_of_table_sentinel
2921 __used __section(__clk_of_table_end);
2923 static LIST_HEAD(of_clk_providers);
2924 static DEFINE_MUTEX(of_clk_mutex);
2926 struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
2931 EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
2933 struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
2935 struct clk_onecell_data *clk_data = data;
2936 unsigned int idx = clkspec->args[0];
2938 if (idx >= clk_data->clk_num) {
2939 pr_err("%s: invalid clock index %u\n", __func__, idx);
2940 return ERR_PTR(-EINVAL);
2943 return clk_data->clks[idx];
2945 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
2948 * of_clk_add_provider() - Register a clock provider for a node
2949 * @np: Device node pointer associated with clock provider
2950 * @clk_src_get: callback for decoding clock
2951 * @data: context pointer for @clk_src_get callback.
2953 int of_clk_add_provider(struct device_node *np,
2954 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
2958 struct of_clk_provider *cp;
2961 cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL);
2965 cp->node = of_node_get(np);
2967 cp->get = clk_src_get;
2969 mutex_lock(&of_clk_mutex);
2970 list_add(&cp->link, &of_clk_providers);
2971 mutex_unlock(&of_clk_mutex);
2972 pr_debug("Added clock from %s\n", np->full_name);
2974 ret = of_clk_set_defaults(np, true);
2976 of_clk_del_provider(np);
2980 EXPORT_SYMBOL_GPL(of_clk_add_provider);
2983 * of_clk_del_provider() - Remove a previously registered clock provider
2984 * @np: Device node pointer associated with clock provider
2986 void of_clk_del_provider(struct device_node *np)
2988 struct of_clk_provider *cp;
2990 mutex_lock(&of_clk_mutex);
2991 list_for_each_entry(cp, &of_clk_providers, link) {
2992 if (cp->node == np) {
2993 list_del(&cp->link);
2994 of_node_put(cp->node);
2999 mutex_unlock(&of_clk_mutex);
3001 EXPORT_SYMBOL_GPL(of_clk_del_provider);
3003 struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec,
3004 const char *dev_id, const char *con_id)
3006 struct of_clk_provider *provider;
3007 struct clk *clk = ERR_PTR(-EPROBE_DEFER);
3010 return ERR_PTR(-EINVAL);
3012 /* Check if we have such a provider in our array */
3013 mutex_lock(&of_clk_mutex);
3014 list_for_each_entry(provider, &of_clk_providers, link) {
3015 if (provider->node == clkspec->np)
3016 clk = provider->get(clkspec, provider->data);
3018 clk = __clk_create_clk(__clk_get_hw(clk), dev_id,
3021 if (!IS_ERR(clk) && !__clk_get(clk)) {
3022 __clk_free_clk(clk);
3023 clk = ERR_PTR(-ENOENT);
3029 mutex_unlock(&of_clk_mutex);
3035 * of_clk_get_from_provider() - Lookup a clock from a clock provider
3036 * @clkspec: pointer to a clock specifier data structure
3038 * This function looks up a struct clk from the registered list of clock
3039 * providers, an input is a clock specifier data structure as returned
3040 * from the of_parse_phandle_with_args() function call.
3042 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
3044 return __of_clk_get_from_provider(clkspec, NULL, __func__);
3047 int of_clk_get_parent_count(struct device_node *np)
3049 return of_count_phandle_with_args(np, "clocks", "#clock-cells");
3051 EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
3053 const char *of_clk_get_parent_name(struct device_node *np, int index)
3055 struct of_phandle_args clkspec;
3056 struct property *prop;
3057 const char *clk_name;
3067 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
3072 index = clkspec.args_count ? clkspec.args[0] : 0;
3075 /* if there is an indices property, use it to transfer the index
3076 * specified into an array offset for the clock-output-names property.
3078 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
3086 if (of_property_read_string_index(clkspec.np, "clock-output-names",
3090 * Best effort to get the name if the clock has been
3091 * registered with the framework. If the clock isn't
3092 * registered, we return the node name as the name of
3093 * the clock as long as #clock-cells = 0.
3095 clk = of_clk_get_from_provider(&clkspec);
3097 if (clkspec.args_count == 0)
3098 clk_name = clkspec.np->name;
3102 clk_name = __clk_get_name(clk);
3108 of_node_put(clkspec.np);
3111 EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
3114 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
3116 * @np: Device node pointer associated with clock provider
3117 * @parents: pointer to char array that hold the parents' names
3118 * @size: size of the @parents array
3120 * Return: number of parents for the clock node.
3122 int of_clk_parent_fill(struct device_node *np, const char **parents,
3127 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
3132 EXPORT_SYMBOL_GPL(of_clk_parent_fill);
3134 struct clock_provider {
3135 of_clk_init_cb_t clk_init_cb;
3136 struct device_node *np;
3137 struct list_head node;
3141 * This function looks for a parent clock. If there is one, then it
3142 * checks that the provider for this parent clock was initialized, in
3143 * this case the parent clock will be ready.
3145 static int parent_ready(struct device_node *np)
3150 struct clk *clk = of_clk_get(np, i);
3152 /* this parent is ready we can check the next one */
3159 /* at least one parent is not ready, we exit now */
3160 if (PTR_ERR(clk) == -EPROBE_DEFER)
3164 * Here we make assumption that the device tree is
3165 * written correctly. So an error means that there is
3166 * no more parent. As we didn't exit yet, then the
3167 * previous parent are ready. If there is no clock
3168 * parent, no need to wait for them, then we can
3169 * consider their absence as being ready
3176 * of_clk_init() - Scan and init clock providers from the DT
3177 * @matches: array of compatible values and init functions for providers.
3179 * This function scans the device tree for matching clock providers
3180 * and calls their initialization functions. It also does it by trying
3181 * to follow the dependencies.
3183 void __init of_clk_init(const struct of_device_id *matches)
3185 const struct of_device_id *match;
3186 struct device_node *np;
3187 struct clock_provider *clk_provider, *next;
3190 LIST_HEAD(clk_provider_list);
3193 matches = &__clk_of_table;
3195 /* First prepare the list of the clocks providers */
3196 for_each_matching_node_and_match(np, matches, &match) {
3197 struct clock_provider *parent;
3199 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
3201 list_for_each_entry_safe(clk_provider, next,
3202 &clk_provider_list, node) {
3203 list_del(&clk_provider->node);
3204 of_node_put(clk_provider->np);
3205 kfree(clk_provider);
3211 parent->clk_init_cb = match->data;
3212 parent->np = of_node_get(np);
3213 list_add_tail(&parent->node, &clk_provider_list);
3216 while (!list_empty(&clk_provider_list)) {
3217 is_init_done = false;
3218 list_for_each_entry_safe(clk_provider, next,
3219 &clk_provider_list, node) {
3220 if (force || parent_ready(clk_provider->np)) {
3222 clk_provider->clk_init_cb(clk_provider->np);
3223 of_clk_set_defaults(clk_provider->np, true);
3225 list_del(&clk_provider->node);
3226 of_node_put(clk_provider->np);
3227 kfree(clk_provider);
3228 is_init_done = true;
3233 * We didn't manage to initialize any of the
3234 * remaining providers during the last loop, so now we
3235 * initialize all the remaining ones unconditionally
3236 * in case the clock parent was not mandatory