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)
354 if (!core->parents[index])
355 core->parents[index] =
356 clk_core_lookup(core->parent_names[index]);
358 return core->parents[index];
362 clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
364 struct clk_core *parent;
366 parent = clk_core_get_parent_by_index(hw->core, index);
368 return !parent ? NULL : parent->hw;
370 EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
372 unsigned int __clk_get_enable_count(struct clk *clk)
374 return !clk ? 0 : clk->core->enable_count;
377 static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
388 if (!core->num_parents)
398 unsigned long clk_hw_get_rate(const struct clk_hw *hw)
400 return clk_core_get_rate_nolock(hw->core);
402 EXPORT_SYMBOL_GPL(clk_hw_get_rate);
404 static unsigned long __clk_get_accuracy(struct clk_core *core)
409 return core->accuracy;
412 unsigned long __clk_get_flags(struct clk *clk)
414 return !clk ? 0 : clk->core->flags;
416 EXPORT_SYMBOL_GPL(__clk_get_flags);
418 unsigned long clk_hw_get_flags(const struct clk_hw *hw)
420 return hw->core->flags;
422 EXPORT_SYMBOL_GPL(clk_hw_get_flags);
424 bool clk_hw_is_prepared(const struct clk_hw *hw)
426 return clk_core_is_prepared(hw->core);
429 bool clk_hw_is_enabled(const struct clk_hw *hw)
431 return clk_core_is_enabled(hw->core);
434 bool __clk_is_enabled(struct clk *clk)
439 return clk_core_is_enabled(clk->core);
441 EXPORT_SYMBOL_GPL(__clk_is_enabled);
443 static bool mux_is_better_rate(unsigned long rate, unsigned long now,
444 unsigned long best, unsigned long flags)
446 if (flags & CLK_MUX_ROUND_CLOSEST)
447 return abs(now - rate) < abs(best - rate);
449 return now <= rate && now > best;
453 clk_mux_determine_rate_flags(struct clk_hw *hw, struct clk_rate_request *req,
456 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
457 int i, num_parents, ret;
458 unsigned long best = 0;
459 struct clk_rate_request parent_req = *req;
461 /* if NO_REPARENT flag set, pass through to current parent */
462 if (core->flags & CLK_SET_RATE_NO_REPARENT) {
463 parent = core->parent;
464 if (core->flags & CLK_SET_RATE_PARENT) {
465 ret = __clk_determine_rate(parent ? parent->hw : NULL,
470 best = parent_req.rate;
472 best = clk_core_get_rate_nolock(parent);
474 best = clk_core_get_rate_nolock(core);
480 /* find the parent that can provide the fastest rate <= rate */
481 num_parents = core->num_parents;
482 for (i = 0; i < num_parents; i++) {
483 parent = clk_core_get_parent_by_index(core, i);
487 if (core->flags & CLK_SET_RATE_PARENT) {
489 ret = __clk_determine_rate(parent->hw, &parent_req);
493 parent_req.rate = clk_core_get_rate_nolock(parent);
496 if (mux_is_better_rate(req->rate, parent_req.rate,
498 best_parent = parent;
499 best = parent_req.rate;
508 req->best_parent_hw = best_parent->hw;
509 req->best_parent_rate = best;
515 struct clk *__clk_lookup(const char *name)
517 struct clk_core *core = clk_core_lookup(name);
519 return !core ? NULL : core->hw->clk;
522 static void clk_core_get_boundaries(struct clk_core *core,
523 unsigned long *min_rate,
524 unsigned long *max_rate)
526 struct clk *clk_user;
528 *min_rate = core->min_rate;
529 *max_rate = core->max_rate;
531 hlist_for_each_entry(clk_user, &core->clks, clks_node)
532 *min_rate = max(*min_rate, clk_user->min_rate);
534 hlist_for_each_entry(clk_user, &core->clks, clks_node)
535 *max_rate = min(*max_rate, clk_user->max_rate);
538 void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
539 unsigned long max_rate)
541 hw->core->min_rate = min_rate;
542 hw->core->max_rate = max_rate;
544 EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
547 * Helper for finding best parent to provide a given frequency. This can be used
548 * directly as a determine_rate callback (e.g. for a mux), or from a more
549 * complex clock that may combine a mux with other operations.
551 int __clk_mux_determine_rate(struct clk_hw *hw,
552 struct clk_rate_request *req)
554 return clk_mux_determine_rate_flags(hw, req, 0);
556 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
558 int __clk_mux_determine_rate_closest(struct clk_hw *hw,
559 struct clk_rate_request *req)
561 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
563 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
567 static void clk_core_unprepare(struct clk_core *core)
569 lockdep_assert_held(&prepare_lock);
574 if (WARN_ON(core->prepare_count == 0))
577 if (--core->prepare_count > 0)
580 WARN_ON(core->enable_count > 0);
582 trace_clk_unprepare(core);
584 if (core->ops->unprepare)
585 core->ops->unprepare(core->hw);
587 trace_clk_unprepare_complete(core);
588 clk_core_unprepare(core->parent);
592 * clk_unprepare - undo preparation of a clock source
593 * @clk: the clk being unprepared
595 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
596 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
597 * if the operation may sleep. One example is a clk which is accessed over
598 * I2c. In the complex case a clk gate operation may require a fast and a slow
599 * part. It is this reason that clk_unprepare and clk_disable are not mutually
600 * exclusive. In fact clk_disable must be called before clk_unprepare.
602 void clk_unprepare(struct clk *clk)
604 if (IS_ERR_OR_NULL(clk))
608 clk_core_unprepare(clk->core);
609 clk_prepare_unlock();
611 EXPORT_SYMBOL_GPL(clk_unprepare);
613 static int clk_core_prepare(struct clk_core *core)
617 lockdep_assert_held(&prepare_lock);
622 if (core->prepare_count == 0) {
623 ret = clk_core_prepare(core->parent);
627 trace_clk_prepare(core);
629 if (core->ops->prepare)
630 ret = core->ops->prepare(core->hw);
632 trace_clk_prepare_complete(core);
635 clk_core_unprepare(core->parent);
640 core->prepare_count++;
646 * clk_prepare - prepare a clock source
647 * @clk: the clk being prepared
649 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
650 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
651 * operation may sleep. One example is a clk which is accessed over I2c. In
652 * the complex case a clk ungate operation may require a fast and a slow part.
653 * It is this reason that clk_prepare and clk_enable are not mutually
654 * exclusive. In fact clk_prepare must be called before clk_enable.
655 * Returns 0 on success, -EERROR otherwise.
657 int clk_prepare(struct clk *clk)
665 ret = clk_core_prepare(clk->core);
666 clk_prepare_unlock();
670 EXPORT_SYMBOL_GPL(clk_prepare);
672 static void clk_core_disable(struct clk_core *core)
674 lockdep_assert_held(&enable_lock);
679 if (WARN_ON(core->enable_count == 0))
682 if (--core->enable_count > 0)
685 trace_clk_disable(core);
687 if (core->ops->disable)
688 core->ops->disable(core->hw);
690 trace_clk_disable_complete(core);
692 clk_core_disable(core->parent);
696 * clk_disable - gate a clock
697 * @clk: the clk being gated
699 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
700 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
701 * clk if the operation is fast and will never sleep. One example is a
702 * SoC-internal clk which is controlled via simple register writes. In the
703 * complex case a clk gate operation may require a fast and a slow part. It is
704 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
705 * In fact clk_disable must be called before clk_unprepare.
707 void clk_disable(struct clk *clk)
711 if (IS_ERR_OR_NULL(clk))
714 flags = clk_enable_lock();
715 clk_core_disable(clk->core);
716 clk_enable_unlock(flags);
718 EXPORT_SYMBOL_GPL(clk_disable);
720 static int clk_core_enable(struct clk_core *core)
724 lockdep_assert_held(&enable_lock);
729 if (WARN_ON(core->prepare_count == 0))
732 if (core->enable_count == 0) {
733 ret = clk_core_enable(core->parent);
738 trace_clk_enable(core);
740 if (core->ops->enable)
741 ret = core->ops->enable(core->hw);
743 trace_clk_enable_complete(core);
746 clk_core_disable(core->parent);
751 core->enable_count++;
756 * clk_enable - ungate a clock
757 * @clk: the clk being ungated
759 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
760 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
761 * if the operation will never sleep. One example is a SoC-internal clk which
762 * is controlled via simple register writes. In the complex case a clk ungate
763 * operation may require a fast and a slow part. It is this reason that
764 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
765 * must be called before clk_enable. Returns 0 on success, -EERROR
768 int clk_enable(struct clk *clk)
776 flags = clk_enable_lock();
777 ret = clk_core_enable(clk->core);
778 clk_enable_unlock(flags);
782 EXPORT_SYMBOL_GPL(clk_enable);
784 static int clk_core_round_rate_nolock(struct clk_core *core,
785 struct clk_rate_request *req)
787 struct clk_core *parent;
790 lockdep_assert_held(&prepare_lock);
795 parent = core->parent;
797 req->best_parent_hw = parent->hw;
798 req->best_parent_rate = parent->rate;
800 req->best_parent_hw = NULL;
801 req->best_parent_rate = 0;
804 if (core->ops->determine_rate) {
805 return core->ops->determine_rate(core->hw, req);
806 } else if (core->ops->round_rate) {
807 rate = core->ops->round_rate(core->hw, req->rate,
808 &req->best_parent_rate);
813 } else if (core->flags & CLK_SET_RATE_PARENT) {
814 return clk_core_round_rate_nolock(parent, req);
816 req->rate = core->rate;
823 * __clk_determine_rate - get the closest rate actually supported by a clock
824 * @hw: determine the rate of this clock
826 * @min_rate: returned rate must be greater than this rate
827 * @max_rate: returned rate must be less than this rate
829 * Useful for clk_ops such as .set_rate and .determine_rate.
831 int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
838 return clk_core_round_rate_nolock(hw->core, req);
840 EXPORT_SYMBOL_GPL(__clk_determine_rate);
842 unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
845 struct clk_rate_request req;
847 clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate);
850 ret = clk_core_round_rate_nolock(hw->core, &req);
856 EXPORT_SYMBOL_GPL(clk_hw_round_rate);
859 * clk_round_rate - round the given rate for a clk
860 * @clk: the clk for which we are rounding a rate
861 * @rate: the rate which is to be rounded
863 * Takes in a rate as input and rounds it to a rate that the clk can actually
864 * use which is then returned. If clk doesn't support round_rate operation
865 * then the parent rate is returned.
867 long clk_round_rate(struct clk *clk, unsigned long rate)
869 struct clk_rate_request req;
877 clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
880 ret = clk_core_round_rate_nolock(clk->core, &req);
881 clk_prepare_unlock();
888 EXPORT_SYMBOL_GPL(clk_round_rate);
891 * __clk_notify - call clk notifier chain
892 * @core: clk that is changing rate
893 * @msg: clk notifier type (see include/linux/clk.h)
894 * @old_rate: old clk rate
895 * @new_rate: new clk rate
897 * Triggers a notifier call chain on the clk rate-change notification
898 * for 'clk'. Passes a pointer to the struct clk and the previous
899 * and current rates to the notifier callback. Intended to be called by
900 * internal clock code only. Returns NOTIFY_DONE from the last driver
901 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
902 * a driver returns that.
904 static int __clk_notify(struct clk_core *core, unsigned long msg,
905 unsigned long old_rate, unsigned long new_rate)
907 struct clk_notifier *cn;
908 struct clk_notifier_data cnd;
909 int ret = NOTIFY_DONE;
911 cnd.old_rate = old_rate;
912 cnd.new_rate = new_rate;
914 list_for_each_entry(cn, &clk_notifier_list, node) {
915 if (cn->clk->core == core) {
917 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
926 * __clk_recalc_accuracies
927 * @core: first clk in the subtree
929 * Walks the subtree of clks starting with clk and recalculates accuracies as
930 * it goes. Note that if a clk does not implement the .recalc_accuracy
931 * callback then it is assumed that the clock will take on the accuracy of its
934 static void __clk_recalc_accuracies(struct clk_core *core)
936 unsigned long parent_accuracy = 0;
937 struct clk_core *child;
939 lockdep_assert_held(&prepare_lock);
942 parent_accuracy = core->parent->accuracy;
944 if (core->ops->recalc_accuracy)
945 core->accuracy = core->ops->recalc_accuracy(core->hw,
948 core->accuracy = parent_accuracy;
950 hlist_for_each_entry(child, &core->children, child_node)
951 __clk_recalc_accuracies(child);
954 static long clk_core_get_accuracy(struct clk_core *core)
956 unsigned long accuracy;
959 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
960 __clk_recalc_accuracies(core);
962 accuracy = __clk_get_accuracy(core);
963 clk_prepare_unlock();
969 * clk_get_accuracy - return the accuracy of clk
970 * @clk: the clk whose accuracy is being returned
972 * Simply returns the cached accuracy of the clk, unless
973 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
975 * If clk is NULL then returns 0.
977 long clk_get_accuracy(struct clk *clk)
982 return clk_core_get_accuracy(clk->core);
984 EXPORT_SYMBOL_GPL(clk_get_accuracy);
986 static unsigned long clk_recalc(struct clk_core *core,
987 unsigned long parent_rate)
989 if (core->ops->recalc_rate)
990 return core->ops->recalc_rate(core->hw, parent_rate);
996 * @core: first clk in the subtree
997 * @msg: notification type (see include/linux/clk.h)
999 * Walks the subtree of clks starting with clk and recalculates rates as it
1000 * goes. Note that if a clk does not implement the .recalc_rate callback then
1001 * it is assumed that the clock will take on the rate of its parent.
1003 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1006 static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
1008 unsigned long old_rate;
1009 unsigned long parent_rate = 0;
1010 struct clk_core *child;
1012 lockdep_assert_held(&prepare_lock);
1014 old_rate = core->rate;
1017 parent_rate = core->parent->rate;
1019 core->rate = clk_recalc(core, parent_rate);
1022 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1023 * & ABORT_RATE_CHANGE notifiers
1025 if (core->notifier_count && msg)
1026 __clk_notify(core, msg, old_rate, core->rate);
1028 hlist_for_each_entry(child, &core->children, child_node)
1029 __clk_recalc_rates(child, msg);
1032 static unsigned long clk_core_get_rate(struct clk_core *core)
1038 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1039 __clk_recalc_rates(core, 0);
1041 rate = clk_core_get_rate_nolock(core);
1042 clk_prepare_unlock();
1048 * clk_get_rate - return the rate of clk
1049 * @clk: the clk whose rate is being returned
1051 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1052 * is set, which means a recalc_rate will be issued.
1053 * If clk is NULL then returns 0.
1055 unsigned long clk_get_rate(struct clk *clk)
1060 return clk_core_get_rate(clk->core);
1062 EXPORT_SYMBOL_GPL(clk_get_rate);
1064 static int clk_fetch_parent_index(struct clk_core *core,
1065 struct clk_core *parent)
1072 for (i = 0; i < core->num_parents; i++)
1073 if (clk_core_get_parent_by_index(core, i) == parent)
1080 * Update the orphan status of @core and all its children.
1082 static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
1084 struct clk_core *child;
1086 core->orphan = is_orphan;
1088 hlist_for_each_entry(child, &core->children, child_node)
1089 clk_core_update_orphan_status(child, is_orphan);
1092 static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1094 bool was_orphan = core->orphan;
1096 hlist_del(&core->child_node);
1099 bool becomes_orphan = new_parent->orphan;
1101 /* avoid duplicate POST_RATE_CHANGE notifications */
1102 if (new_parent->new_child == core)
1103 new_parent->new_child = NULL;
1105 hlist_add_head(&core->child_node, &new_parent->children);
1107 if (was_orphan != becomes_orphan)
1108 clk_core_update_orphan_status(core, becomes_orphan);
1110 hlist_add_head(&core->child_node, &clk_orphan_list);
1112 clk_core_update_orphan_status(core, true);
1115 core->parent = new_parent;
1118 static struct clk_core *__clk_set_parent_before(struct clk_core *core,
1119 struct clk_core *parent)
1121 unsigned long flags;
1122 struct clk_core *old_parent = core->parent;
1125 * Migrate prepare state between parents and prevent race with
1128 * If the clock is not prepared, then a race with
1129 * clk_enable/disable() is impossible since we already have the
1130 * prepare lock (future calls to clk_enable() need to be preceded by
1133 * If the clock is prepared, migrate the prepared state to the new
1134 * parent and also protect against a race with clk_enable() by
1135 * forcing the clock and the new parent on. This ensures that all
1136 * future calls to clk_enable() are practically NOPs with respect to
1137 * hardware and software states.
1139 * See also: Comment for clk_set_parent() below.
1141 if (core->prepare_count) {
1142 clk_core_prepare(parent);
1143 flags = clk_enable_lock();
1144 clk_core_enable(parent);
1145 clk_core_enable(core);
1146 clk_enable_unlock(flags);
1149 /* update the clk tree topology */
1150 flags = clk_enable_lock();
1151 clk_reparent(core, parent);
1152 clk_enable_unlock(flags);
1157 static void __clk_set_parent_after(struct clk_core *core,
1158 struct clk_core *parent,
1159 struct clk_core *old_parent)
1161 unsigned long flags;
1164 * Finish the migration of prepare state and undo the changes done
1165 * for preventing a race with clk_enable().
1167 if (core->prepare_count) {
1168 flags = clk_enable_lock();
1169 clk_core_disable(core);
1170 clk_core_disable(old_parent);
1171 clk_enable_unlock(flags);
1172 clk_core_unprepare(old_parent);
1176 static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
1179 unsigned long flags;
1181 struct clk_core *old_parent;
1183 old_parent = __clk_set_parent_before(core, parent);
1185 trace_clk_set_parent(core, parent);
1187 /* change clock input source */
1188 if (parent && core->ops->set_parent)
1189 ret = core->ops->set_parent(core->hw, p_index);
1191 trace_clk_set_parent_complete(core, parent);
1194 flags = clk_enable_lock();
1195 clk_reparent(core, old_parent);
1196 clk_enable_unlock(flags);
1197 __clk_set_parent_after(core, old_parent, parent);
1202 __clk_set_parent_after(core, parent, old_parent);
1208 * __clk_speculate_rates
1209 * @core: first clk in the subtree
1210 * @parent_rate: the "future" rate of clk's parent
1212 * Walks the subtree of clks starting with clk, speculating rates as it
1213 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1215 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1216 * pre-rate change notifications and returns early if no clks in the
1217 * subtree have subscribed to the notifications. Note that if a clk does not
1218 * implement the .recalc_rate callback then it is assumed that the clock will
1219 * take on the rate of its parent.
1221 static int __clk_speculate_rates(struct clk_core *core,
1222 unsigned long parent_rate)
1224 struct clk_core *child;
1225 unsigned long new_rate;
1226 int ret = NOTIFY_DONE;
1228 lockdep_assert_held(&prepare_lock);
1230 new_rate = clk_recalc(core, parent_rate);
1232 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1233 if (core->notifier_count)
1234 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
1236 if (ret & NOTIFY_STOP_MASK) {
1237 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1238 __func__, core->name, ret);
1242 hlist_for_each_entry(child, &core->children, child_node) {
1243 ret = __clk_speculate_rates(child, new_rate);
1244 if (ret & NOTIFY_STOP_MASK)
1252 static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
1253 struct clk_core *new_parent, u8 p_index)
1255 struct clk_core *child;
1257 core->new_rate = new_rate;
1258 core->new_parent = new_parent;
1259 core->new_parent_index = p_index;
1260 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1261 core->new_child = NULL;
1262 if (new_parent && new_parent != core->parent)
1263 new_parent->new_child = core;
1265 hlist_for_each_entry(child, &core->children, child_node) {
1266 child->new_rate = clk_recalc(child, new_rate);
1267 clk_calc_subtree(child, child->new_rate, NULL, 0);
1272 * calculate the new rates returning the topmost clock that has to be
1275 static struct clk_core *clk_calc_new_rates(struct clk_core *core,
1278 struct clk_core *top = core;
1279 struct clk_core *old_parent, *parent;
1280 unsigned long best_parent_rate = 0;
1281 unsigned long new_rate;
1282 unsigned long min_rate;
1283 unsigned long max_rate;
1288 if (IS_ERR_OR_NULL(core))
1291 /* save parent rate, if it exists */
1292 parent = old_parent = core->parent;
1294 best_parent_rate = parent->rate;
1296 clk_core_get_boundaries(core, &min_rate, &max_rate);
1298 /* find the closest rate and parent clk/rate */
1299 if (core->ops->determine_rate) {
1300 struct clk_rate_request req;
1303 req.min_rate = min_rate;
1304 req.max_rate = max_rate;
1306 req.best_parent_hw = parent->hw;
1307 req.best_parent_rate = parent->rate;
1309 req.best_parent_hw = NULL;
1310 req.best_parent_rate = 0;
1313 ret = core->ops->determine_rate(core->hw, &req);
1317 best_parent_rate = req.best_parent_rate;
1318 new_rate = req.rate;
1319 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
1320 } else if (core->ops->round_rate) {
1321 ret = core->ops->round_rate(core->hw, rate,
1327 if (new_rate < min_rate || new_rate > max_rate)
1329 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
1330 /* pass-through clock without adjustable parent */
1331 core->new_rate = core->rate;
1334 /* pass-through clock with adjustable parent */
1335 top = clk_calc_new_rates(parent, rate);
1336 new_rate = parent->new_rate;
1340 /* some clocks must be gated to change parent */
1341 if (parent != old_parent &&
1342 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1343 pr_debug("%s: %s not gated but wants to reparent\n",
1344 __func__, core->name);
1348 /* try finding the new parent index */
1349 if (parent && core->num_parents > 1) {
1350 p_index = clk_fetch_parent_index(core, parent);
1352 pr_debug("%s: clk %s can not be parent of clk %s\n",
1353 __func__, parent->name, core->name);
1358 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
1359 best_parent_rate != parent->rate)
1360 top = clk_calc_new_rates(parent, best_parent_rate);
1363 clk_calc_subtree(core, new_rate, parent, p_index);
1369 * Notify about rate changes in a subtree. Always walk down the whole tree
1370 * so that in case of an error we can walk down the whole tree again and
1373 static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
1374 unsigned long event)
1376 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
1377 int ret = NOTIFY_DONE;
1379 if (core->rate == core->new_rate)
1382 if (core->notifier_count) {
1383 ret = __clk_notify(core, event, core->rate, core->new_rate);
1384 if (ret & NOTIFY_STOP_MASK)
1388 hlist_for_each_entry(child, &core->children, child_node) {
1389 /* Skip children who will be reparented to another clock */
1390 if (child->new_parent && child->new_parent != core)
1392 tmp_clk = clk_propagate_rate_change(child, event);
1397 /* handle the new child who might not be in core->children yet */
1398 if (core->new_child) {
1399 tmp_clk = clk_propagate_rate_change(core->new_child, event);
1408 * walk down a subtree and set the new rates notifying the rate
1411 static void clk_change_rate(struct clk_core *core)
1413 struct clk_core *child;
1414 struct hlist_node *tmp;
1415 unsigned long old_rate;
1416 unsigned long best_parent_rate = 0;
1417 bool skip_set_rate = false;
1418 struct clk_core *old_parent;
1420 old_rate = core->rate;
1422 if (core->new_parent)
1423 best_parent_rate = core->new_parent->rate;
1424 else if (core->parent)
1425 best_parent_rate = core->parent->rate;
1427 if (core->flags & CLK_SET_RATE_UNGATE) {
1428 unsigned long flags;
1430 clk_core_prepare(core);
1431 flags = clk_enable_lock();
1432 clk_core_enable(core);
1433 clk_enable_unlock(flags);
1436 if (core->new_parent && core->new_parent != core->parent) {
1437 old_parent = __clk_set_parent_before(core, core->new_parent);
1438 trace_clk_set_parent(core, core->new_parent);
1440 if (core->ops->set_rate_and_parent) {
1441 skip_set_rate = true;
1442 core->ops->set_rate_and_parent(core->hw, core->new_rate,
1444 core->new_parent_index);
1445 } else if (core->ops->set_parent) {
1446 core->ops->set_parent(core->hw, core->new_parent_index);
1449 trace_clk_set_parent_complete(core, core->new_parent);
1450 __clk_set_parent_after(core, core->new_parent, old_parent);
1453 trace_clk_set_rate(core, core->new_rate);
1455 if (!skip_set_rate && core->ops->set_rate)
1456 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
1458 trace_clk_set_rate_complete(core, core->new_rate);
1460 core->rate = clk_recalc(core, best_parent_rate);
1462 if (core->flags & CLK_SET_RATE_UNGATE) {
1463 unsigned long flags;
1465 flags = clk_enable_lock();
1466 clk_core_disable(core);
1467 clk_enable_unlock(flags);
1468 clk_core_unprepare(core);
1471 if (core->notifier_count && old_rate != core->rate)
1472 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
1474 if (core->flags & CLK_RECALC_NEW_RATES)
1475 (void)clk_calc_new_rates(core, core->new_rate);
1478 * Use safe iteration, as change_rate can actually swap parents
1479 * for certain clock types.
1481 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
1482 /* Skip children who will be reparented to another clock */
1483 if (child->new_parent && child->new_parent != core)
1485 clk_change_rate(child);
1488 /* handle the new child who might not be in core->children yet */
1489 if (core->new_child)
1490 clk_change_rate(core->new_child);
1493 static int clk_core_set_rate_nolock(struct clk_core *core,
1494 unsigned long req_rate)
1496 struct clk_core *top, *fail_clk;
1497 unsigned long rate = req_rate;
1503 /* bail early if nothing to do */
1504 if (rate == clk_core_get_rate_nolock(core))
1507 if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count)
1510 /* calculate new rates and get the topmost changed clock */
1511 top = clk_calc_new_rates(core, rate);
1515 /* notify that we are about to change rates */
1516 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
1518 pr_debug("%s: failed to set %s rate\n", __func__,
1520 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
1524 /* change the rates */
1525 clk_change_rate(top);
1527 core->req_rate = req_rate;
1533 * clk_set_rate - specify a new rate for clk
1534 * @clk: the clk whose rate is being changed
1535 * @rate: the new rate for clk
1537 * In the simplest case clk_set_rate will only adjust the rate of clk.
1539 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1540 * propagate up to clk's parent; whether or not this happens depends on the
1541 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1542 * after calling .round_rate then upstream parent propagation is ignored. If
1543 * *parent_rate comes back with a new rate for clk's parent then we propagate
1544 * up to clk's parent and set its rate. Upward propagation will continue
1545 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1546 * .round_rate stops requesting changes to clk's parent_rate.
1548 * Rate changes are accomplished via tree traversal that also recalculates the
1549 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
1551 * Returns 0 on success, -EERROR otherwise.
1553 int clk_set_rate(struct clk *clk, unsigned long rate)
1560 /* prevent racing with updates to the clock topology */
1563 ret = clk_core_set_rate_nolock(clk->core, rate);
1565 clk_prepare_unlock();
1569 EXPORT_SYMBOL_GPL(clk_set_rate);
1572 * clk_set_rate_range - set a rate range for a clock source
1573 * @clk: clock source
1574 * @min: desired minimum clock rate in Hz, inclusive
1575 * @max: desired maximum clock rate in Hz, inclusive
1577 * Returns success (0) or negative errno.
1579 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
1587 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
1588 __func__, clk->core->name, clk->dev_id, clk->con_id,
1595 if (min != clk->min_rate || max != clk->max_rate) {
1596 clk->min_rate = min;
1597 clk->max_rate = max;
1598 ret = clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
1601 clk_prepare_unlock();
1605 EXPORT_SYMBOL_GPL(clk_set_rate_range);
1608 * clk_set_min_rate - set a minimum clock rate for a clock source
1609 * @clk: clock source
1610 * @rate: desired minimum clock rate in Hz, inclusive
1612 * Returns success (0) or negative errno.
1614 int clk_set_min_rate(struct clk *clk, unsigned long rate)
1619 return clk_set_rate_range(clk, rate, clk->max_rate);
1621 EXPORT_SYMBOL_GPL(clk_set_min_rate);
1624 * clk_set_max_rate - set a maximum clock rate for a clock source
1625 * @clk: clock source
1626 * @rate: desired maximum clock rate in Hz, inclusive
1628 * Returns success (0) or negative errno.
1630 int clk_set_max_rate(struct clk *clk, unsigned long rate)
1635 return clk_set_rate_range(clk, clk->min_rate, rate);
1637 EXPORT_SYMBOL_GPL(clk_set_max_rate);
1640 * clk_get_parent - return the parent of a clk
1641 * @clk: the clk whose parent gets returned
1643 * Simply returns clk->parent. Returns NULL if clk is NULL.
1645 struct clk *clk_get_parent(struct clk *clk)
1653 /* TODO: Create a per-user clk and change callers to call clk_put */
1654 parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
1655 clk_prepare_unlock();
1659 EXPORT_SYMBOL_GPL(clk_get_parent);
1661 static struct clk_core *__clk_init_parent(struct clk_core *core)
1665 if (core->num_parents > 1 && core->ops->get_parent)
1666 index = core->ops->get_parent(core->hw);
1668 return clk_core_get_parent_by_index(core, index);
1671 static void clk_core_reparent(struct clk_core *core,
1672 struct clk_core *new_parent)
1674 clk_reparent(core, new_parent);
1675 __clk_recalc_accuracies(core);
1676 __clk_recalc_rates(core, POST_RATE_CHANGE);
1679 void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
1684 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
1688 * clk_has_parent - check if a clock is a possible parent for another
1689 * @clk: clock source
1690 * @parent: parent clock source
1692 * This function can be used in drivers that need to check that a clock can be
1693 * the parent of another without actually changing the parent.
1695 * Returns true if @parent is a possible parent for @clk, false otherwise.
1697 bool clk_has_parent(struct clk *clk, struct clk *parent)
1699 struct clk_core *core, *parent_core;
1702 /* NULL clocks should be nops, so return success if either is NULL. */
1703 if (!clk || !parent)
1707 parent_core = parent->core;
1709 /* Optimize for the case where the parent is already the parent. */
1710 if (core->parent == parent_core)
1713 for (i = 0; i < core->num_parents; i++)
1714 if (strcmp(core->parent_names[i], parent_core->name) == 0)
1719 EXPORT_SYMBOL_GPL(clk_has_parent);
1721 static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent)
1725 unsigned long p_rate = 0;
1730 /* prevent racing with updates to the clock topology */
1733 if (core->parent == parent)
1736 /* verify ops for for multi-parent clks */
1737 if ((core->num_parents > 1) && (!core->ops->set_parent)) {
1742 /* check that we are allowed to re-parent if the clock is in use */
1743 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1748 /* try finding the new parent index */
1750 p_index = clk_fetch_parent_index(core, parent);
1752 pr_debug("%s: clk %s can not be parent of clk %s\n",
1753 __func__, parent->name, core->name);
1757 p_rate = parent->rate;
1760 /* propagate PRE_RATE_CHANGE notifications */
1761 ret = __clk_speculate_rates(core, p_rate);
1763 /* abort if a driver objects */
1764 if (ret & NOTIFY_STOP_MASK)
1767 /* do the re-parent */
1768 ret = __clk_set_parent(core, parent, p_index);
1770 /* propagate rate an accuracy recalculation accordingly */
1772 __clk_recalc_rates(core, ABORT_RATE_CHANGE);
1774 __clk_recalc_rates(core, POST_RATE_CHANGE);
1775 __clk_recalc_accuracies(core);
1779 clk_prepare_unlock();
1785 * clk_set_parent - switch the parent of a mux clk
1786 * @clk: the mux clk whose input we are switching
1787 * @parent: the new input to clk
1789 * Re-parent clk to use parent as its new input source. If clk is in
1790 * prepared state, the clk will get enabled for the duration of this call. If
1791 * that's not acceptable for a specific clk (Eg: the consumer can't handle
1792 * that, the reparenting is glitchy in hardware, etc), use the
1793 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
1795 * After successfully changing clk's parent clk_set_parent will update the
1796 * clk topology, sysfs topology and propagate rate recalculation via
1797 * __clk_recalc_rates.
1799 * Returns 0 on success, -EERROR otherwise.
1801 int clk_set_parent(struct clk *clk, struct clk *parent)
1806 return clk_core_set_parent(clk->core, parent ? parent->core : NULL);
1808 EXPORT_SYMBOL_GPL(clk_set_parent);
1811 * clk_set_phase - adjust the phase shift of a clock signal
1812 * @clk: clock signal source
1813 * @degrees: number of degrees the signal is shifted
1815 * Shifts the phase of a clock signal by the specified
1816 * degrees. Returns 0 on success, -EERROR otherwise.
1818 * This function makes no distinction about the input or reference
1819 * signal that we adjust the clock signal phase against. For example
1820 * phase locked-loop clock signal generators we may shift phase with
1821 * respect to feedback clock signal input, but for other cases the
1822 * clock phase may be shifted with respect to some other, unspecified
1825 * Additionally the concept of phase shift does not propagate through
1826 * the clock tree hierarchy, which sets it apart from clock rates and
1827 * clock accuracy. A parent clock phase attribute does not have an
1828 * impact on the phase attribute of a child clock.
1830 int clk_set_phase(struct clk *clk, int degrees)
1837 /* sanity check degrees */
1844 /* bail early if nothing to do */
1845 if (degrees == clk->core->phase)
1848 trace_clk_set_phase(clk->core, degrees);
1850 if (clk->core->ops->set_phase)
1851 ret = clk->core->ops->set_phase(clk->core->hw, degrees);
1853 trace_clk_set_phase_complete(clk->core, degrees);
1856 clk->core->phase = degrees;
1859 clk_prepare_unlock();
1863 EXPORT_SYMBOL_GPL(clk_set_phase);
1865 static int clk_core_get_phase(struct clk_core *core)
1871 clk_prepare_unlock();
1877 * clk_get_phase - return the phase shift of a clock signal
1878 * @clk: clock signal source
1880 * Returns the phase shift of a clock node in degrees, otherwise returns
1883 int clk_get_phase(struct clk *clk)
1888 return clk_core_get_phase(clk->core);
1890 EXPORT_SYMBOL_GPL(clk_get_phase);
1893 * clk_is_match - check if two clk's point to the same hardware clock
1894 * @p: clk compared against q
1895 * @q: clk compared against p
1897 * Returns true if the two struct clk pointers both point to the same hardware
1898 * clock node. Put differently, returns true if struct clk *p and struct clk *q
1899 * share the same struct clk_core object.
1901 * Returns false otherwise. Note that two NULL clks are treated as matching.
1903 bool clk_is_match(const struct clk *p, const struct clk *q)
1905 /* trivial case: identical struct clk's or both NULL */
1909 /* true if clk->core pointers match. Avoid dereferencing garbage */
1910 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
1911 if (p->core == q->core)
1916 EXPORT_SYMBOL_GPL(clk_is_match);
1918 /*** debugfs support ***/
1920 #ifdef CONFIG_DEBUG_FS
1921 #include <linux/debugfs.h>
1923 static struct dentry *rootdir;
1924 static int inited = 0;
1925 static DEFINE_MUTEX(clk_debug_lock);
1926 static HLIST_HEAD(clk_debug_list);
1928 static struct hlist_head *all_lists[] = {
1934 static struct hlist_head *orphan_list[] = {
1939 static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
1945 seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu %-3d\n",
1947 30 - level * 3, c->name,
1948 c->enable_count, c->prepare_count, clk_core_get_rate(c),
1949 clk_core_get_accuracy(c), clk_core_get_phase(c));
1952 static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
1955 struct clk_core *child;
1960 clk_summary_show_one(s, c, level);
1962 hlist_for_each_entry(child, &c->children, child_node)
1963 clk_summary_show_subtree(s, child, level + 1);
1966 static int clk_summary_show(struct seq_file *s, void *data)
1969 struct hlist_head **lists = (struct hlist_head **)s->private;
1971 seq_puts(s, " clock enable_cnt prepare_cnt rate accuracy phase\n");
1972 seq_puts(s, "----------------------------------------------------------------------------------------\n");
1976 for (; *lists; lists++)
1977 hlist_for_each_entry(c, *lists, child_node)
1978 clk_summary_show_subtree(s, c, 0);
1980 clk_prepare_unlock();
1986 static int clk_summary_open(struct inode *inode, struct file *file)
1988 return single_open(file, clk_summary_show, inode->i_private);
1991 static const struct file_operations clk_summary_fops = {
1992 .open = clk_summary_open,
1994 .llseek = seq_lseek,
1995 .release = single_release,
1998 static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
2003 /* This should be JSON format, i.e. elements separated with a comma */
2004 seq_printf(s, "\"%s\": { ", c->name);
2005 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
2006 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
2007 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate(c));
2008 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c));
2009 seq_printf(s, "\"phase\": %d", clk_core_get_phase(c));
2012 static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
2014 struct clk_core *child;
2019 clk_dump_one(s, c, level);
2021 hlist_for_each_entry(child, &c->children, child_node) {
2023 clk_dump_subtree(s, child, level + 1);
2029 static int clk_dump(struct seq_file *s, void *data)
2032 bool first_node = true;
2033 struct hlist_head **lists = (struct hlist_head **)s->private;
2039 for (; *lists; lists++) {
2040 hlist_for_each_entry(c, *lists, child_node) {
2044 clk_dump_subtree(s, c, 0);
2048 clk_prepare_unlock();
2055 static int clk_dump_open(struct inode *inode, struct file *file)
2057 return single_open(file, clk_dump, inode->i_private);
2060 static const struct file_operations clk_dump_fops = {
2061 .open = clk_dump_open,
2063 .llseek = seq_lseek,
2064 .release = single_release,
2067 static int clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
2072 if (!core || !pdentry) {
2077 d = debugfs_create_dir(core->name, pdentry);
2083 d = debugfs_create_u32("clk_rate", S_IRUGO, core->dentry,
2084 (u32 *)&core->rate);
2088 d = debugfs_create_u32("clk_accuracy", S_IRUGO, core->dentry,
2089 (u32 *)&core->accuracy);
2093 d = debugfs_create_u32("clk_phase", S_IRUGO, core->dentry,
2094 (u32 *)&core->phase);
2098 d = debugfs_create_x32("clk_flags", S_IRUGO, core->dentry,
2099 (u32 *)&core->flags);
2103 d = debugfs_create_u32("clk_prepare_count", S_IRUGO, core->dentry,
2104 (u32 *)&core->prepare_count);
2108 d = debugfs_create_u32("clk_enable_count", S_IRUGO, core->dentry,
2109 (u32 *)&core->enable_count);
2113 d = debugfs_create_u32("clk_notifier_count", S_IRUGO, core->dentry,
2114 (u32 *)&core->notifier_count);
2118 if (core->ops->debug_init) {
2119 ret = core->ops->debug_init(core->hw, core->dentry);
2128 debugfs_remove_recursive(core->dentry);
2129 core->dentry = NULL;
2135 * clk_debug_register - add a clk node to the debugfs clk directory
2136 * @core: the clk being added to the debugfs clk directory
2138 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
2139 * initialized. Otherwise it bails out early since the debugfs clk directory
2140 * will be created lazily by clk_debug_init as part of a late_initcall.
2142 static int clk_debug_register(struct clk_core *core)
2146 mutex_lock(&clk_debug_lock);
2147 hlist_add_head(&core->debug_node, &clk_debug_list);
2152 ret = clk_debug_create_one(core, rootdir);
2154 mutex_unlock(&clk_debug_lock);
2160 * clk_debug_unregister - remove a clk node from the debugfs clk directory
2161 * @core: the clk being removed from the debugfs clk directory
2163 * Dynamically removes a clk and all its child nodes from the
2164 * debugfs clk directory if clk->dentry points to debugfs created by
2165 * clk_debug_register in __clk_core_init.
2167 static void clk_debug_unregister(struct clk_core *core)
2169 mutex_lock(&clk_debug_lock);
2170 hlist_del_init(&core->debug_node);
2171 debugfs_remove_recursive(core->dentry);
2172 core->dentry = NULL;
2173 mutex_unlock(&clk_debug_lock);
2176 struct dentry *clk_debugfs_add_file(struct clk_hw *hw, char *name, umode_t mode,
2177 void *data, const struct file_operations *fops)
2179 struct dentry *d = NULL;
2181 if (hw->core->dentry)
2182 d = debugfs_create_file(name, mode, hw->core->dentry, data,
2187 EXPORT_SYMBOL_GPL(clk_debugfs_add_file);
2190 * clk_debug_init - lazily populate the debugfs clk directory
2192 * clks are often initialized very early during boot before memory can be
2193 * dynamically allocated and well before debugfs is setup. This function
2194 * populates the debugfs clk directory once at boot-time when we know that
2195 * debugfs is setup. It should only be called once at boot-time, all other clks
2196 * added dynamically will be done so with clk_debug_register.
2198 static int __init clk_debug_init(void)
2200 struct clk_core *core;
2203 rootdir = debugfs_create_dir("clk", NULL);
2208 d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists,
2213 d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists,
2218 d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir,
2219 &orphan_list, &clk_summary_fops);
2223 d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir,
2224 &orphan_list, &clk_dump_fops);
2228 mutex_lock(&clk_debug_lock);
2229 hlist_for_each_entry(core, &clk_debug_list, debug_node)
2230 clk_debug_create_one(core, rootdir);
2233 mutex_unlock(&clk_debug_lock);
2237 late_initcall(clk_debug_init);
2239 static inline int clk_debug_register(struct clk_core *core) { return 0; }
2240 static inline void clk_debug_reparent(struct clk_core *core,
2241 struct clk_core *new_parent)
2244 static inline void clk_debug_unregister(struct clk_core *core)
2250 * __clk_core_init - initialize the data structures in a struct clk_core
2251 * @core: clk_core being initialized
2253 * Initializes the lists in struct clk_core, queries the hardware for the
2254 * parent and rate and sets them both.
2256 static int __clk_core_init(struct clk_core *core)
2259 struct clk_core *orphan;
2260 struct hlist_node *tmp2;
2268 /* check to see if a clock with this name is already registered */
2269 if (clk_core_lookup(core->name)) {
2270 pr_debug("%s: clk %s already initialized\n",
2271 __func__, core->name);
2276 /* check that clk_ops are sane. See Documentation/clk.txt */
2277 if (core->ops->set_rate &&
2278 !((core->ops->round_rate || core->ops->determine_rate) &&
2279 core->ops->recalc_rate)) {
2280 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
2281 __func__, core->name);
2286 if (core->ops->set_parent && !core->ops->get_parent) {
2287 pr_err("%s: %s must implement .get_parent & .set_parent\n",
2288 __func__, core->name);
2293 if (core->num_parents > 1 && !core->ops->get_parent) {
2294 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
2295 __func__, core->name);
2300 if (core->ops->set_rate_and_parent &&
2301 !(core->ops->set_parent && core->ops->set_rate)) {
2302 pr_err("%s: %s must implement .set_parent & .set_rate\n",
2303 __func__, core->name);
2308 /* throw a WARN if any entries in parent_names are NULL */
2309 for (i = 0; i < core->num_parents; i++)
2310 WARN(!core->parent_names[i],
2311 "%s: invalid NULL in %s's .parent_names\n",
2312 __func__, core->name);
2314 core->parent = __clk_init_parent(core);
2317 * Populate core->parent if parent has already been clk_core_init'd. If
2318 * parent has not yet been clk_core_init'd then place clk in the orphan
2319 * list. If clk doesn't have any parents then place it in the root
2322 * Every time a new clk is clk_init'd then we walk the list of orphan
2323 * clocks and re-parent any that are children of the clock currently
2327 hlist_add_head(&core->child_node,
2328 &core->parent->children);
2329 core->orphan = core->parent->orphan;
2330 } else if (!core->num_parents) {
2331 hlist_add_head(&core->child_node, &clk_root_list);
2332 core->orphan = false;
2334 hlist_add_head(&core->child_node, &clk_orphan_list);
2335 core->orphan = true;
2339 * Set clk's accuracy. The preferred method is to use
2340 * .recalc_accuracy. For simple clocks and lazy developers the default
2341 * fallback is to use the parent's accuracy. If a clock doesn't have a
2342 * parent (or is orphaned) then accuracy is set to zero (perfect
2345 if (core->ops->recalc_accuracy)
2346 core->accuracy = core->ops->recalc_accuracy(core->hw,
2347 __clk_get_accuracy(core->parent));
2348 else if (core->parent)
2349 core->accuracy = core->parent->accuracy;
2355 * Since a phase is by definition relative to its parent, just
2356 * query the current clock phase, or just assume it's in phase.
2358 if (core->ops->get_phase)
2359 core->phase = core->ops->get_phase(core->hw);
2364 * Set clk's rate. The preferred method is to use .recalc_rate. For
2365 * simple clocks and lazy developers the default fallback is to use the
2366 * parent's rate. If a clock doesn't have a parent (or is orphaned)
2367 * then rate is set to zero.
2369 if (core->ops->recalc_rate)
2370 rate = core->ops->recalc_rate(core->hw,
2371 clk_core_get_rate_nolock(core->parent));
2372 else if (core->parent)
2373 rate = core->parent->rate;
2376 core->rate = core->req_rate = rate;
2379 * walk the list of orphan clocks and reparent any that newly finds a
2382 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
2383 struct clk_core *parent = __clk_init_parent(orphan);
2386 clk_core_reparent(orphan, parent);
2390 * optional platform-specific magic
2392 * The .init callback is not used by any of the basic clock types, but
2393 * exists for weird hardware that must perform initialization magic.
2394 * Please consider other ways of solving initialization problems before
2395 * using this callback, as its use is discouraged.
2397 if (core->ops->init)
2398 core->ops->init(core->hw);
2400 kref_init(&core->ref);
2402 clk_prepare_unlock();
2405 clk_debug_register(core);
2410 struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,
2415 /* This is to allow this function to be chained to others */
2416 if (IS_ERR_OR_NULL(hw))
2417 return (struct clk *) hw;
2419 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
2421 return ERR_PTR(-ENOMEM);
2423 clk->core = hw->core;
2424 clk->dev_id = dev_id;
2425 clk->con_id = con_id;
2426 clk->max_rate = ULONG_MAX;
2429 hlist_add_head(&clk->clks_node, &hw->core->clks);
2430 clk_prepare_unlock();
2435 void __clk_free_clk(struct clk *clk)
2438 hlist_del(&clk->clks_node);
2439 clk_prepare_unlock();
2445 * clk_register - allocate a new clock, register it and return an opaque cookie
2446 * @dev: device that is registering this clock
2447 * @hw: link to hardware-specific clock data
2449 * clk_register is the primary interface for populating the clock tree with new
2450 * clock nodes. It returns a pointer to the newly allocated struct clk which
2451 * cannot be dereferenced by driver code but may be used in conjunction with the
2452 * rest of the clock API. In the event of an error clk_register will return an
2453 * error code; drivers must test for an error code after calling clk_register.
2455 struct clk *clk_register(struct device *dev, struct clk_hw *hw)
2458 struct clk_core *core;
2460 core = kzalloc(sizeof(*core), GFP_KERNEL);
2466 core->name = kstrdup_const(hw->init->name, GFP_KERNEL);
2471 core->ops = hw->init->ops;
2472 if (dev && dev->driver)
2473 core->owner = dev->driver->owner;
2475 core->flags = hw->init->flags;
2476 core->num_parents = hw->init->num_parents;
2478 core->max_rate = ULONG_MAX;
2481 /* allocate local copy in case parent_names is __initdata */
2482 core->parent_names = kcalloc(core->num_parents, sizeof(char *),
2485 if (!core->parent_names) {
2487 goto fail_parent_names;
2491 /* copy each string name in case parent_names is __initdata */
2492 for (i = 0; i < core->num_parents; i++) {
2493 core->parent_names[i] = kstrdup_const(hw->init->parent_names[i],
2495 if (!core->parent_names[i]) {
2497 goto fail_parent_names_copy;
2501 /* avoid unnecessary string look-ups of clk_core's possible parents. */
2502 core->parents = kcalloc(core->num_parents, sizeof(*core->parents),
2504 if (!core->parents) {
2509 INIT_HLIST_HEAD(&core->clks);
2511 hw->clk = __clk_create_clk(hw, NULL, NULL);
2512 if (IS_ERR(hw->clk)) {
2513 ret = PTR_ERR(hw->clk);
2517 ret = __clk_core_init(core);
2521 __clk_free_clk(hw->clk);
2525 kfree(core->parents);
2526 fail_parent_names_copy:
2528 kfree_const(core->parent_names[i]);
2529 kfree(core->parent_names);
2531 kfree_const(core->name);
2535 return ERR_PTR(ret);
2537 EXPORT_SYMBOL_GPL(clk_register);
2539 /* Free memory allocated for a clock. */
2540 static void __clk_release(struct kref *ref)
2542 struct clk_core *core = container_of(ref, struct clk_core, ref);
2543 int i = core->num_parents;
2545 lockdep_assert_held(&prepare_lock);
2547 kfree(core->parents);
2549 kfree_const(core->parent_names[i]);
2551 kfree(core->parent_names);
2552 kfree_const(core->name);
2557 * Empty clk_ops for unregistered clocks. These are used temporarily
2558 * after clk_unregister() was called on a clock and until last clock
2559 * consumer calls clk_put() and the struct clk object is freed.
2561 static int clk_nodrv_prepare_enable(struct clk_hw *hw)
2566 static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
2571 static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
2572 unsigned long parent_rate)
2577 static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
2582 static const struct clk_ops clk_nodrv_ops = {
2583 .enable = clk_nodrv_prepare_enable,
2584 .disable = clk_nodrv_disable_unprepare,
2585 .prepare = clk_nodrv_prepare_enable,
2586 .unprepare = clk_nodrv_disable_unprepare,
2587 .set_rate = clk_nodrv_set_rate,
2588 .set_parent = clk_nodrv_set_parent,
2592 * clk_unregister - unregister a currently registered clock
2593 * @clk: clock to unregister
2595 void clk_unregister(struct clk *clk)
2597 unsigned long flags;
2599 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2602 clk_debug_unregister(clk->core);
2606 if (clk->core->ops == &clk_nodrv_ops) {
2607 pr_err("%s: unregistered clock: %s\n", __func__,
2612 * Assign empty clock ops for consumers that might still hold
2613 * a reference to this clock.
2615 flags = clk_enable_lock();
2616 clk->core->ops = &clk_nodrv_ops;
2617 clk_enable_unlock(flags);
2619 if (!hlist_empty(&clk->core->children)) {
2620 struct clk_core *child;
2621 struct hlist_node *t;
2623 /* Reparent all children to the orphan list. */
2624 hlist_for_each_entry_safe(child, t, &clk->core->children,
2626 clk_core_set_parent(child, NULL);
2629 hlist_del_init(&clk->core->child_node);
2631 if (clk->core->prepare_count)
2632 pr_warn("%s: unregistering prepared clock: %s\n",
2633 __func__, clk->core->name);
2634 kref_put(&clk->core->ref, __clk_release);
2636 clk_prepare_unlock();
2638 EXPORT_SYMBOL_GPL(clk_unregister);
2640 static void devm_clk_release(struct device *dev, void *res)
2642 clk_unregister(*(struct clk **)res);
2646 * devm_clk_register - resource managed clk_register()
2647 * @dev: device that is registering this clock
2648 * @hw: link to hardware-specific clock data
2650 * Managed clk_register(). Clocks returned from this function are
2651 * automatically clk_unregister()ed on driver detach. See clk_register() for
2654 struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
2659 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
2661 return ERR_PTR(-ENOMEM);
2663 clk = clk_register(dev, hw);
2666 devres_add(dev, clkp);
2673 EXPORT_SYMBOL_GPL(devm_clk_register);
2675 static int devm_clk_match(struct device *dev, void *res, void *data)
2677 struct clk *c = res;
2684 * devm_clk_unregister - resource managed clk_unregister()
2685 * @clk: clock to unregister
2687 * Deallocate a clock allocated with devm_clk_register(). Normally
2688 * this function will not need to be called and the resource management
2689 * code will ensure that the resource is freed.
2691 void devm_clk_unregister(struct device *dev, struct clk *clk)
2693 WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
2695 EXPORT_SYMBOL_GPL(devm_clk_unregister);
2700 int __clk_get(struct clk *clk)
2702 struct clk_core *core = !clk ? NULL : clk->core;
2705 if (!try_module_get(core->owner))
2708 kref_get(&core->ref);
2713 void __clk_put(struct clk *clk)
2715 struct module *owner;
2717 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2722 hlist_del(&clk->clks_node);
2723 if (clk->min_rate > clk->core->req_rate ||
2724 clk->max_rate < clk->core->req_rate)
2725 clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
2727 owner = clk->core->owner;
2728 kref_put(&clk->core->ref, __clk_release);
2730 clk_prepare_unlock();
2737 /*** clk rate change notifiers ***/
2740 * clk_notifier_register - add a clk rate change notifier
2741 * @clk: struct clk * to watch
2742 * @nb: struct notifier_block * with callback info
2744 * Request notification when clk's rate changes. This uses an SRCU
2745 * notifier because we want it to block and notifier unregistrations are
2746 * uncommon. The callbacks associated with the notifier must not
2747 * re-enter into the clk framework by calling any top-level clk APIs;
2748 * this will cause a nested prepare_lock mutex.
2750 * In all notification cases (pre, post and abort rate change) the original
2751 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
2752 * and the new frequency is passed via struct clk_notifier_data.new_rate.
2754 * clk_notifier_register() must be called from non-atomic context.
2755 * Returns -EINVAL if called with null arguments, -ENOMEM upon
2756 * allocation failure; otherwise, passes along the return value of
2757 * srcu_notifier_chain_register().
2759 int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
2761 struct clk_notifier *cn;
2769 /* search the list of notifiers for this clk */
2770 list_for_each_entry(cn, &clk_notifier_list, node)
2774 /* if clk wasn't in the notifier list, allocate new clk_notifier */
2775 if (cn->clk != clk) {
2776 cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL);
2781 srcu_init_notifier_head(&cn->notifier_head);
2783 list_add(&cn->node, &clk_notifier_list);
2786 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
2788 clk->core->notifier_count++;
2791 clk_prepare_unlock();
2795 EXPORT_SYMBOL_GPL(clk_notifier_register);
2798 * clk_notifier_unregister - remove a clk rate change notifier
2799 * @clk: struct clk *
2800 * @nb: struct notifier_block * with callback info
2802 * Request no further notification for changes to 'clk' and frees memory
2803 * allocated in clk_notifier_register.
2805 * Returns -EINVAL if called with null arguments; otherwise, passes
2806 * along the return value of srcu_notifier_chain_unregister().
2808 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
2810 struct clk_notifier *cn = NULL;
2818 list_for_each_entry(cn, &clk_notifier_list, node)
2822 if (cn->clk == clk) {
2823 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
2825 clk->core->notifier_count--;
2827 /* XXX the notifier code should handle this better */
2828 if (!cn->notifier_head.head) {
2829 srcu_cleanup_notifier_head(&cn->notifier_head);
2830 list_del(&cn->node);
2838 clk_prepare_unlock();
2842 EXPORT_SYMBOL_GPL(clk_notifier_unregister);
2846 * struct of_clk_provider - Clock provider registration structure
2847 * @link: Entry in global list of clock providers
2848 * @node: Pointer to device tree node of clock provider
2849 * @get: Get clock callback. Returns NULL or a struct clk for the
2850 * given clock specifier
2851 * @data: context pointer to be passed into @get callback
2853 struct of_clk_provider {
2854 struct list_head link;
2856 struct device_node *node;
2857 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
2861 static const struct of_device_id __clk_of_table_sentinel
2862 __used __section(__clk_of_table_end);
2864 static LIST_HEAD(of_clk_providers);
2865 static DEFINE_MUTEX(of_clk_mutex);
2867 struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
2872 EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
2874 struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
2876 struct clk_onecell_data *clk_data = data;
2877 unsigned int idx = clkspec->args[0];
2879 if (idx >= clk_data->clk_num) {
2880 pr_err("%s: invalid clock index %u\n", __func__, idx);
2881 return ERR_PTR(-EINVAL);
2884 return clk_data->clks[idx];
2886 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
2889 * of_clk_add_provider() - Register a clock provider for a node
2890 * @np: Device node pointer associated with clock provider
2891 * @clk_src_get: callback for decoding clock
2892 * @data: context pointer for @clk_src_get callback.
2894 int of_clk_add_provider(struct device_node *np,
2895 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
2899 struct of_clk_provider *cp;
2902 cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL);
2906 cp->node = of_node_get(np);
2908 cp->get = clk_src_get;
2910 mutex_lock(&of_clk_mutex);
2911 list_add(&cp->link, &of_clk_providers);
2912 mutex_unlock(&of_clk_mutex);
2913 pr_debug("Added clock from %s\n", np->full_name);
2915 ret = of_clk_set_defaults(np, true);
2917 of_clk_del_provider(np);
2921 EXPORT_SYMBOL_GPL(of_clk_add_provider);
2924 * of_clk_del_provider() - Remove a previously registered clock provider
2925 * @np: Device node pointer associated with clock provider
2927 void of_clk_del_provider(struct device_node *np)
2929 struct of_clk_provider *cp;
2931 mutex_lock(&of_clk_mutex);
2932 list_for_each_entry(cp, &of_clk_providers, link) {
2933 if (cp->node == np) {
2934 list_del(&cp->link);
2935 of_node_put(cp->node);
2940 mutex_unlock(&of_clk_mutex);
2942 EXPORT_SYMBOL_GPL(of_clk_del_provider);
2944 struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec,
2945 const char *dev_id, const char *con_id)
2947 struct of_clk_provider *provider;
2948 struct clk *clk = ERR_PTR(-EPROBE_DEFER);
2951 return ERR_PTR(-EINVAL);
2953 /* Check if we have such a provider in our array */
2954 mutex_lock(&of_clk_mutex);
2955 list_for_each_entry(provider, &of_clk_providers, link) {
2956 if (provider->node == clkspec->np)
2957 clk = provider->get(clkspec, provider->data);
2959 clk = __clk_create_clk(__clk_get_hw(clk), dev_id,
2962 if (!IS_ERR(clk) && !__clk_get(clk)) {
2963 __clk_free_clk(clk);
2964 clk = ERR_PTR(-ENOENT);
2970 mutex_unlock(&of_clk_mutex);
2976 * of_clk_get_from_provider() - Lookup a clock from a clock provider
2977 * @clkspec: pointer to a clock specifier data structure
2979 * This function looks up a struct clk from the registered list of clock
2980 * providers, an input is a clock specifier data structure as returned
2981 * from the of_parse_phandle_with_args() function call.
2983 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
2985 return __of_clk_get_from_provider(clkspec, NULL, __func__);
2987 EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
2990 * of_clk_get_parent_count() - Count the number of clocks a device node has
2991 * @np: device node to count
2993 * Returns: The number of clocks that are possible parents of this node
2995 unsigned int of_clk_get_parent_count(struct device_node *np)
2999 count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
3005 EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
3007 const char *of_clk_get_parent_name(struct device_node *np, int index)
3009 struct of_phandle_args clkspec;
3010 struct property *prop;
3011 const char *clk_name;
3018 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
3023 index = clkspec.args_count ? clkspec.args[0] : 0;
3026 /* if there is an indices property, use it to transfer the index
3027 * specified into an array offset for the clock-output-names property.
3029 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
3036 /* We went off the end of 'clock-indices' without finding it */
3040 if (of_property_read_string_index(clkspec.np, "clock-output-names",
3044 * Best effort to get the name if the clock has been
3045 * registered with the framework. If the clock isn't
3046 * registered, we return the node name as the name of
3047 * the clock as long as #clock-cells = 0.
3049 clk = of_clk_get_from_provider(&clkspec);
3051 if (clkspec.args_count == 0)
3052 clk_name = clkspec.np->name;
3056 clk_name = __clk_get_name(clk);
3062 of_node_put(clkspec.np);
3065 EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
3068 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
3070 * @np: Device node pointer associated with clock provider
3071 * @parents: pointer to char array that hold the parents' names
3072 * @size: size of the @parents array
3074 * Return: number of parents for the clock node.
3076 int of_clk_parent_fill(struct device_node *np, const char **parents,
3081 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
3086 EXPORT_SYMBOL_GPL(of_clk_parent_fill);
3088 struct clock_provider {
3089 of_clk_init_cb_t clk_init_cb;
3090 struct device_node *np;
3091 struct list_head node;
3095 * This function looks for a parent clock. If there is one, then it
3096 * checks that the provider for this parent clock was initialized, in
3097 * this case the parent clock will be ready.
3099 static int parent_ready(struct device_node *np)
3104 struct clk *clk = of_clk_get(np, i);
3106 /* this parent is ready we can check the next one */
3113 /* at least one parent is not ready, we exit now */
3114 if (PTR_ERR(clk) == -EPROBE_DEFER)
3118 * Here we make assumption that the device tree is
3119 * written correctly. So an error means that there is
3120 * no more parent. As we didn't exit yet, then the
3121 * previous parent are ready. If there is no clock
3122 * parent, no need to wait for them, then we can
3123 * consider their absence as being ready
3130 * of_clk_init() - Scan and init clock providers from the DT
3131 * @matches: array of compatible values and init functions for providers.
3133 * This function scans the device tree for matching clock providers
3134 * and calls their initialization functions. It also does it by trying
3135 * to follow the dependencies.
3137 void __init of_clk_init(const struct of_device_id *matches)
3139 const struct of_device_id *match;
3140 struct device_node *np;
3141 struct clock_provider *clk_provider, *next;
3144 LIST_HEAD(clk_provider_list);
3147 matches = &__clk_of_table;
3149 /* First prepare the list of the clocks providers */
3150 for_each_matching_node_and_match(np, matches, &match) {
3151 struct clock_provider *parent;
3153 if (!of_device_is_available(np))
3156 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
3158 list_for_each_entry_safe(clk_provider, next,
3159 &clk_provider_list, node) {
3160 list_del(&clk_provider->node);
3161 of_node_put(clk_provider->np);
3162 kfree(clk_provider);
3168 parent->clk_init_cb = match->data;
3169 parent->np = of_node_get(np);
3170 list_add_tail(&parent->node, &clk_provider_list);
3173 while (!list_empty(&clk_provider_list)) {
3174 is_init_done = false;
3175 list_for_each_entry_safe(clk_provider, next,
3176 &clk_provider_list, node) {
3177 if (force || parent_ready(clk_provider->np)) {
3179 clk_provider->clk_init_cb(clk_provider->np);
3180 of_clk_set_defaults(clk_provider->np, true);
3182 list_del(&clk_provider->node);
3183 of_node_put(clk_provider->np);
3184 kfree(clk_provider);
3185 is_init_done = true;
3190 * We didn't manage to initialize any of the
3191 * remaining providers during the last loop, so now we
3192 * initialize all the remaining ones unconditionally
3193 * in case the clock parent was not mandatory