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;
60 unsigned int enable_count;
61 unsigned int prepare_count;
62 unsigned long min_rate;
63 unsigned long max_rate;
64 unsigned long accuracy;
66 struct hlist_head children;
67 struct hlist_node child_node;
68 struct hlist_head clks;
69 unsigned int notifier_count;
70 #ifdef CONFIG_DEBUG_FS
71 struct dentry *dentry;
72 struct hlist_node debug_node;
77 #define CREATE_TRACE_POINTS
78 #include <trace/events/clk.h>
81 struct clk_core *core;
84 unsigned long min_rate;
85 unsigned long max_rate;
86 struct hlist_node clks_node;
90 static void clk_prepare_lock(void)
92 if (!mutex_trylock(&prepare_lock)) {
93 if (prepare_owner == current) {
97 mutex_lock(&prepare_lock);
99 WARN_ON_ONCE(prepare_owner != NULL);
100 WARN_ON_ONCE(prepare_refcnt != 0);
101 prepare_owner = current;
105 static void clk_prepare_unlock(void)
107 WARN_ON_ONCE(prepare_owner != current);
108 WARN_ON_ONCE(prepare_refcnt == 0);
110 if (--prepare_refcnt)
112 prepare_owner = NULL;
113 mutex_unlock(&prepare_lock);
116 static unsigned long clk_enable_lock(void)
117 __acquires(enable_lock)
121 if (!spin_trylock_irqsave(&enable_lock, flags)) {
122 if (enable_owner == current) {
124 __acquire(enable_lock);
127 spin_lock_irqsave(&enable_lock, flags);
129 WARN_ON_ONCE(enable_owner != NULL);
130 WARN_ON_ONCE(enable_refcnt != 0);
131 enable_owner = current;
136 static void clk_enable_unlock(unsigned long flags)
137 __releases(enable_lock)
139 WARN_ON_ONCE(enable_owner != current);
140 WARN_ON_ONCE(enable_refcnt == 0);
142 if (--enable_refcnt) {
143 __release(enable_lock);
147 spin_unlock_irqrestore(&enable_lock, flags);
150 static bool clk_core_is_prepared(struct clk_core *core)
153 * .is_prepared is optional for clocks that can prepare
154 * fall back to software usage counter if it is missing
156 if (!core->ops->is_prepared)
157 return core->prepare_count;
159 return core->ops->is_prepared(core->hw);
162 static bool clk_core_is_enabled(struct clk_core *core)
165 * .is_enabled is only mandatory for clocks that gate
166 * fall back to software usage counter if .is_enabled is missing
168 if (!core->ops->is_enabled)
169 return core->enable_count;
171 return core->ops->is_enabled(core->hw);
174 static void clk_unprepare_unused_subtree(struct clk_core *core)
176 struct clk_core *child;
178 lockdep_assert_held(&prepare_lock);
180 hlist_for_each_entry(child, &core->children, child_node)
181 clk_unprepare_unused_subtree(child);
183 if (core->prepare_count)
186 if (core->flags & CLK_IGNORE_UNUSED)
189 if (clk_core_is_prepared(core)) {
190 trace_clk_unprepare(core);
191 if (core->ops->unprepare_unused)
192 core->ops->unprepare_unused(core->hw);
193 else if (core->ops->unprepare)
194 core->ops->unprepare(core->hw);
195 trace_clk_unprepare_complete(core);
199 static void clk_disable_unused_subtree(struct clk_core *core)
201 struct clk_core *child;
204 lockdep_assert_held(&prepare_lock);
206 hlist_for_each_entry(child, &core->children, child_node)
207 clk_disable_unused_subtree(child);
209 flags = clk_enable_lock();
211 if (core->enable_count)
214 if (core->flags & CLK_IGNORE_UNUSED)
218 * some gate clocks have special needs during the disable-unused
219 * sequence. call .disable_unused if available, otherwise fall
222 if (clk_core_is_enabled(core)) {
223 trace_clk_disable(core);
224 if (core->ops->disable_unused)
225 core->ops->disable_unused(core->hw);
226 else if (core->ops->disable)
227 core->ops->disable(core->hw);
228 trace_clk_disable_complete(core);
232 clk_enable_unlock(flags);
235 static bool clk_ignore_unused;
236 static int __init clk_ignore_unused_setup(char *__unused)
238 clk_ignore_unused = true;
241 __setup("clk_ignore_unused", clk_ignore_unused_setup);
243 static int clk_disable_unused(void)
245 struct clk_core *core;
247 if (clk_ignore_unused) {
248 pr_warn("clk: Not disabling unused clocks\n");
254 hlist_for_each_entry(core, &clk_root_list, child_node)
255 clk_disable_unused_subtree(core);
257 hlist_for_each_entry(core, &clk_orphan_list, child_node)
258 clk_disable_unused_subtree(core);
260 hlist_for_each_entry(core, &clk_root_list, child_node)
261 clk_unprepare_unused_subtree(core);
263 hlist_for_each_entry(core, &clk_orphan_list, child_node)
264 clk_unprepare_unused_subtree(core);
266 clk_prepare_unlock();
270 late_initcall_sync(clk_disable_unused);
272 /*** helper functions ***/
274 const char *__clk_get_name(struct clk *clk)
276 return !clk ? NULL : clk->core->name;
278 EXPORT_SYMBOL_GPL(__clk_get_name);
280 struct clk_hw *__clk_get_hw(struct clk *clk)
282 return !clk ? NULL : clk->core->hw;
284 EXPORT_SYMBOL_GPL(__clk_get_hw);
286 u8 __clk_get_num_parents(struct clk *clk)
288 return !clk ? 0 : clk->core->num_parents;
290 EXPORT_SYMBOL_GPL(__clk_get_num_parents);
292 struct clk *__clk_get_parent(struct clk *clk)
297 /* TODO: Create a per-user clk and change callers to call clk_put */
298 return !clk->core->parent ? NULL : clk->core->parent->hw->clk;
300 EXPORT_SYMBOL_GPL(__clk_get_parent);
302 static struct clk_core *__clk_lookup_subtree(const char *name,
303 struct clk_core *core)
305 struct clk_core *child;
306 struct clk_core *ret;
308 if (!strcmp(core->name, name))
311 hlist_for_each_entry(child, &core->children, child_node) {
312 ret = __clk_lookup_subtree(name, child);
320 static struct clk_core *clk_core_lookup(const char *name)
322 struct clk_core *root_clk;
323 struct clk_core *ret;
328 /* search the 'proper' clk tree first */
329 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
330 ret = __clk_lookup_subtree(name, root_clk);
335 /* if not found, then search the orphan tree */
336 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
337 ret = __clk_lookup_subtree(name, root_clk);
345 static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
348 if (!core || index >= core->num_parents)
350 else if (!core->parents)
351 return clk_core_lookup(core->parent_names[index]);
352 else if (!core->parents[index])
353 return core->parents[index] =
354 clk_core_lookup(core->parent_names[index]);
356 return core->parents[index];
359 struct clk *clk_get_parent_by_index(struct clk *clk, u8 index)
361 struct clk_core *parent;
366 parent = clk_core_get_parent_by_index(clk->core, index);
368 return !parent ? NULL : parent->hw->clk;
370 EXPORT_SYMBOL_GPL(clk_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->flags & CLK_IS_ROOT)
398 unsigned long __clk_get_rate(struct clk *clk)
403 return clk_core_get_rate_nolock(clk->core);
405 EXPORT_SYMBOL_GPL(__clk_get_rate);
407 static unsigned long __clk_get_accuracy(struct clk_core *core)
412 return core->accuracy;
415 unsigned long __clk_get_flags(struct clk *clk)
417 return !clk ? 0 : clk->core->flags;
419 EXPORT_SYMBOL_GPL(__clk_get_flags);
421 bool __clk_is_prepared(struct clk *clk)
426 return clk_core_is_prepared(clk->core);
429 bool __clk_is_enabled(struct clk *clk)
434 return clk_core_is_enabled(clk->core);
436 EXPORT_SYMBOL_GPL(__clk_is_enabled);
438 static bool mux_is_better_rate(unsigned long rate, unsigned long now,
439 unsigned long best, unsigned long flags)
441 if (flags & CLK_MUX_ROUND_CLOSEST)
442 return abs(now - rate) < abs(best - rate);
444 return now <= rate && now > best;
448 clk_mux_determine_rate_flags(struct clk_hw *hw, struct clk_rate_request *req,
451 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
452 int i, num_parents, ret;
453 unsigned long best = 0;
454 struct clk_rate_request parent_req = *req;
456 /* if NO_REPARENT flag set, pass through to current parent */
457 if (core->flags & CLK_SET_RATE_NO_REPARENT) {
458 parent = core->parent;
459 if (core->flags & CLK_SET_RATE_PARENT) {
460 ret = __clk_determine_rate(parent ? parent->hw : NULL,
465 best = parent_req.rate;
467 best = clk_core_get_rate_nolock(parent);
469 best = clk_core_get_rate_nolock(core);
475 /* find the parent that can provide the fastest rate <= rate */
476 num_parents = core->num_parents;
477 for (i = 0; i < num_parents; i++) {
478 parent = clk_core_get_parent_by_index(core, i);
482 if (core->flags & CLK_SET_RATE_PARENT) {
484 ret = __clk_determine_rate(parent->hw, &parent_req);
488 parent_req.rate = clk_core_get_rate_nolock(parent);
491 if (mux_is_better_rate(req->rate, parent_req.rate,
493 best_parent = parent;
494 best = parent_req.rate;
503 req->best_parent_hw = best_parent->hw;
504 req->best_parent_rate = best;
510 struct clk *__clk_lookup(const char *name)
512 struct clk_core *core = clk_core_lookup(name);
514 return !core ? NULL : core->hw->clk;
517 static void clk_core_get_boundaries(struct clk_core *core,
518 unsigned long *min_rate,
519 unsigned long *max_rate)
521 struct clk *clk_user;
523 *min_rate = core->min_rate;
524 *max_rate = core->max_rate;
526 hlist_for_each_entry(clk_user, &core->clks, clks_node)
527 *min_rate = max(*min_rate, clk_user->min_rate);
529 hlist_for_each_entry(clk_user, &core->clks, clks_node)
530 *max_rate = min(*max_rate, clk_user->max_rate);
533 void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
534 unsigned long max_rate)
536 hw->core->min_rate = min_rate;
537 hw->core->max_rate = max_rate;
539 EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
542 * Helper for finding best parent to provide a given frequency. This can be used
543 * directly as a determine_rate callback (e.g. for a mux), or from a more
544 * complex clock that may combine a mux with other operations.
546 int __clk_mux_determine_rate(struct clk_hw *hw,
547 struct clk_rate_request *req)
549 return clk_mux_determine_rate_flags(hw, req, 0);
551 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
553 int __clk_mux_determine_rate_closest(struct clk_hw *hw,
554 struct clk_rate_request *req)
556 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
558 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
562 static void clk_core_unprepare(struct clk_core *core)
564 lockdep_assert_held(&prepare_lock);
569 if (WARN_ON(core->prepare_count == 0))
572 if (--core->prepare_count > 0)
575 WARN_ON(core->enable_count > 0);
577 trace_clk_unprepare(core);
579 if (core->ops->unprepare)
580 core->ops->unprepare(core->hw);
582 trace_clk_unprepare_complete(core);
583 clk_core_unprepare(core->parent);
587 * clk_unprepare - undo preparation of a clock source
588 * @clk: the clk being unprepared
590 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
591 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
592 * if the operation may sleep. One example is a clk which is accessed over
593 * I2c. In the complex case a clk gate operation may require a fast and a slow
594 * part. It is this reason that clk_unprepare and clk_disable are not mutually
595 * exclusive. In fact clk_disable must be called before clk_unprepare.
597 void clk_unprepare(struct clk *clk)
599 if (IS_ERR_OR_NULL(clk))
603 clk_core_unprepare(clk->core);
604 clk_prepare_unlock();
606 EXPORT_SYMBOL_GPL(clk_unprepare);
608 static int clk_core_prepare(struct clk_core *core)
612 lockdep_assert_held(&prepare_lock);
617 if (core->prepare_count == 0) {
618 ret = clk_core_prepare(core->parent);
622 trace_clk_prepare(core);
624 if (core->ops->prepare)
625 ret = core->ops->prepare(core->hw);
627 trace_clk_prepare_complete(core);
630 clk_core_unprepare(core->parent);
635 core->prepare_count++;
641 * clk_prepare - prepare a clock source
642 * @clk: the clk being prepared
644 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
645 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
646 * operation may sleep. One example is a clk which is accessed over I2c. In
647 * the complex case a clk ungate operation may require a fast and a slow part.
648 * It is this reason that clk_prepare and clk_enable are not mutually
649 * exclusive. In fact clk_prepare must be called before clk_enable.
650 * Returns 0 on success, -EERROR otherwise.
652 int clk_prepare(struct clk *clk)
660 ret = clk_core_prepare(clk->core);
661 clk_prepare_unlock();
665 EXPORT_SYMBOL_GPL(clk_prepare);
667 static void clk_core_disable(struct clk_core *core)
669 lockdep_assert_held(&enable_lock);
674 if (WARN_ON(core->enable_count == 0))
677 if (--core->enable_count > 0)
680 trace_clk_disable(core);
682 if (core->ops->disable)
683 core->ops->disable(core->hw);
685 trace_clk_disable_complete(core);
687 clk_core_disable(core->parent);
691 * clk_disable - gate a clock
692 * @clk: the clk being gated
694 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
695 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
696 * clk if the operation is fast and will never sleep. One example is a
697 * SoC-internal clk which is controlled via simple register writes. In the
698 * complex case a clk gate operation may require a fast and a slow part. It is
699 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
700 * In fact clk_disable must be called before clk_unprepare.
702 void clk_disable(struct clk *clk)
706 if (IS_ERR_OR_NULL(clk))
709 flags = clk_enable_lock();
710 clk_core_disable(clk->core);
711 clk_enable_unlock(flags);
713 EXPORT_SYMBOL_GPL(clk_disable);
715 static int clk_core_enable(struct clk_core *core)
719 lockdep_assert_held(&enable_lock);
724 if (WARN_ON(core->prepare_count == 0))
727 if (core->enable_count == 0) {
728 ret = clk_core_enable(core->parent);
733 trace_clk_enable(core);
735 if (core->ops->enable)
736 ret = core->ops->enable(core->hw);
738 trace_clk_enable_complete(core);
741 clk_core_disable(core->parent);
746 core->enable_count++;
751 * clk_enable - ungate a clock
752 * @clk: the clk being ungated
754 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
755 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
756 * if the operation will never sleep. One example is a SoC-internal clk which
757 * is controlled via simple register writes. In the complex case a clk ungate
758 * operation may require a fast and a slow part. It is this reason that
759 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
760 * must be called before clk_enable. Returns 0 on success, -EERROR
763 int clk_enable(struct clk *clk)
771 flags = clk_enable_lock();
772 ret = clk_core_enable(clk->core);
773 clk_enable_unlock(flags);
777 EXPORT_SYMBOL_GPL(clk_enable);
779 static int clk_core_round_rate_nolock(struct clk_core *core,
780 struct clk_rate_request *req)
782 struct clk_core *parent;
785 lockdep_assert_held(&prepare_lock);
790 parent = core->parent;
792 req->best_parent_hw = parent->hw;
793 req->best_parent_rate = parent->rate;
795 req->best_parent_hw = NULL;
796 req->best_parent_rate = 0;
799 if (core->ops->determine_rate) {
800 return core->ops->determine_rate(core->hw, req);
801 } else if (core->ops->round_rate) {
802 rate = core->ops->round_rate(core->hw, req->rate,
803 &req->best_parent_rate);
808 } else if (core->flags & CLK_SET_RATE_PARENT) {
809 return clk_core_round_rate_nolock(parent, req);
811 req->rate = core->rate;
818 * __clk_determine_rate - get the closest rate actually supported by a clock
819 * @hw: determine the rate of this clock
821 * @min_rate: returned rate must be greater than this rate
822 * @max_rate: returned rate must be less than this rate
824 * Useful for clk_ops such as .set_rate and .determine_rate.
826 int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
833 return clk_core_round_rate_nolock(hw->core, req);
835 EXPORT_SYMBOL_GPL(__clk_determine_rate);
838 * __clk_round_rate - round the given rate for a clk
839 * @clk: round the rate of this clock
840 * @rate: the rate which is to be rounded
842 * Useful for clk_ops such as .set_rate
844 unsigned long __clk_round_rate(struct clk *clk, unsigned long rate)
846 struct clk_rate_request req;
852 clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
855 ret = clk_core_round_rate_nolock(clk->core, &req);
861 EXPORT_SYMBOL_GPL(__clk_round_rate);
864 * clk_round_rate - round the given rate for a clk
865 * @clk: the clk for which we are rounding a rate
866 * @rate: the rate which is to be rounded
868 * Takes in a rate as input and rounds it to a rate that the clk can actually
869 * use which is then returned. If clk doesn't support round_rate operation
870 * then the parent rate is returned.
872 long clk_round_rate(struct clk *clk, unsigned long rate)
880 ret = __clk_round_rate(clk, rate);
881 clk_prepare_unlock();
885 EXPORT_SYMBOL_GPL(clk_round_rate);
888 * __clk_notify - call clk notifier chain
889 * @core: clk that is changing rate
890 * @msg: clk notifier type (see include/linux/clk.h)
891 * @old_rate: old clk rate
892 * @new_rate: new clk rate
894 * Triggers a notifier call chain on the clk rate-change notification
895 * for 'clk'. Passes a pointer to the struct clk and the previous
896 * and current rates to the notifier callback. Intended to be called by
897 * internal clock code only. Returns NOTIFY_DONE from the last driver
898 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
899 * a driver returns that.
901 static int __clk_notify(struct clk_core *core, unsigned long msg,
902 unsigned long old_rate, unsigned long new_rate)
904 struct clk_notifier *cn;
905 struct clk_notifier_data cnd;
906 int ret = NOTIFY_DONE;
908 cnd.old_rate = old_rate;
909 cnd.new_rate = new_rate;
911 list_for_each_entry(cn, &clk_notifier_list, node) {
912 if (cn->clk->core == core) {
914 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
923 * __clk_recalc_accuracies
924 * @core: first clk in the subtree
926 * Walks the subtree of clks starting with clk and recalculates accuracies as
927 * it goes. Note that if a clk does not implement the .recalc_accuracy
928 * callback then it is assumed that the clock will take on the accuracy of its
931 static void __clk_recalc_accuracies(struct clk_core *core)
933 unsigned long parent_accuracy = 0;
934 struct clk_core *child;
936 lockdep_assert_held(&prepare_lock);
939 parent_accuracy = core->parent->accuracy;
941 if (core->ops->recalc_accuracy)
942 core->accuracy = core->ops->recalc_accuracy(core->hw,
945 core->accuracy = parent_accuracy;
947 hlist_for_each_entry(child, &core->children, child_node)
948 __clk_recalc_accuracies(child);
951 static long clk_core_get_accuracy(struct clk_core *core)
953 unsigned long accuracy;
956 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
957 __clk_recalc_accuracies(core);
959 accuracy = __clk_get_accuracy(core);
960 clk_prepare_unlock();
966 * clk_get_accuracy - return the accuracy of clk
967 * @clk: the clk whose accuracy is being returned
969 * Simply returns the cached accuracy of the clk, unless
970 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
972 * If clk is NULL then returns 0.
974 long clk_get_accuracy(struct clk *clk)
979 return clk_core_get_accuracy(clk->core);
981 EXPORT_SYMBOL_GPL(clk_get_accuracy);
983 static unsigned long clk_recalc(struct clk_core *core,
984 unsigned long parent_rate)
986 if (core->ops->recalc_rate)
987 return core->ops->recalc_rate(core->hw, parent_rate);
993 * @core: first clk in the subtree
994 * @msg: notification type (see include/linux/clk.h)
996 * Walks the subtree of clks starting with clk and recalculates rates as it
997 * goes. Note that if a clk does not implement the .recalc_rate callback then
998 * it is assumed that the clock will take on the rate of its parent.
1000 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1003 static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
1005 unsigned long old_rate;
1006 unsigned long parent_rate = 0;
1007 struct clk_core *child;
1009 lockdep_assert_held(&prepare_lock);
1011 old_rate = core->rate;
1014 parent_rate = core->parent->rate;
1016 core->rate = clk_recalc(core, parent_rate);
1019 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1020 * & ABORT_RATE_CHANGE notifiers
1022 if (core->notifier_count && msg)
1023 __clk_notify(core, msg, old_rate, core->rate);
1025 hlist_for_each_entry(child, &core->children, child_node)
1026 __clk_recalc_rates(child, msg);
1029 static unsigned long clk_core_get_rate(struct clk_core *core)
1035 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1036 __clk_recalc_rates(core, 0);
1038 rate = clk_core_get_rate_nolock(core);
1039 clk_prepare_unlock();
1045 * clk_get_rate - return the rate of clk
1046 * @clk: the clk whose rate is being returned
1048 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1049 * is set, which means a recalc_rate will be issued.
1050 * If clk is NULL then returns 0.
1052 unsigned long clk_get_rate(struct clk *clk)
1057 return clk_core_get_rate(clk->core);
1059 EXPORT_SYMBOL_GPL(clk_get_rate);
1061 static int clk_fetch_parent_index(struct clk_core *core,
1062 struct clk_core *parent)
1066 if (!core->parents) {
1067 core->parents = kcalloc(core->num_parents,
1068 sizeof(struct clk *), GFP_KERNEL);
1074 * find index of new parent clock using cached parent ptrs,
1075 * or if not yet cached, use string name comparison and cache
1076 * them now to avoid future calls to clk_core_lookup.
1078 for (i = 0; i < core->num_parents; i++) {
1079 if (core->parents[i] == parent)
1082 if (core->parents[i])
1085 if (!strcmp(core->parent_names[i], parent->name)) {
1086 core->parents[i] = clk_core_lookup(parent->name);
1094 static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1096 hlist_del(&core->child_node);
1099 /* avoid duplicate POST_RATE_CHANGE notifications */
1100 if (new_parent->new_child == core)
1101 new_parent->new_child = NULL;
1103 hlist_add_head(&core->child_node, &new_parent->children);
1105 hlist_add_head(&core->child_node, &clk_orphan_list);
1108 core->parent = new_parent;
1111 static struct clk_core *__clk_set_parent_before(struct clk_core *core,
1112 struct clk_core *parent)
1114 unsigned long flags;
1115 struct clk_core *old_parent = core->parent;
1118 * Migrate prepare state between parents and prevent race with
1121 * If the clock is not prepared, then a race with
1122 * clk_enable/disable() is impossible since we already have the
1123 * prepare lock (future calls to clk_enable() need to be preceded by
1126 * If the clock is prepared, migrate the prepared state to the new
1127 * parent and also protect against a race with clk_enable() by
1128 * forcing the clock and the new parent on. This ensures that all
1129 * future calls to clk_enable() are practically NOPs with respect to
1130 * hardware and software states.
1132 * See also: Comment for clk_set_parent() below.
1134 if (core->prepare_count) {
1135 clk_core_prepare(parent);
1136 flags = clk_enable_lock();
1137 clk_core_enable(parent);
1138 clk_core_enable(core);
1139 clk_enable_unlock(flags);
1142 /* update the clk tree topology */
1143 flags = clk_enable_lock();
1144 clk_reparent(core, parent);
1145 clk_enable_unlock(flags);
1150 static void __clk_set_parent_after(struct clk_core *core,
1151 struct clk_core *parent,
1152 struct clk_core *old_parent)
1154 unsigned long flags;
1157 * Finish the migration of prepare state and undo the changes done
1158 * for preventing a race with clk_enable().
1160 if (core->prepare_count) {
1161 flags = clk_enable_lock();
1162 clk_core_disable(core);
1163 clk_core_disable(old_parent);
1164 clk_enable_unlock(flags);
1165 clk_core_unprepare(old_parent);
1169 static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
1172 unsigned long flags;
1174 struct clk_core *old_parent;
1176 old_parent = __clk_set_parent_before(core, parent);
1178 trace_clk_set_parent(core, parent);
1180 /* change clock input source */
1181 if (parent && core->ops->set_parent)
1182 ret = core->ops->set_parent(core->hw, p_index);
1184 trace_clk_set_parent_complete(core, parent);
1187 flags = clk_enable_lock();
1188 clk_reparent(core, old_parent);
1189 clk_enable_unlock(flags);
1191 if (core->prepare_count) {
1192 flags = clk_enable_lock();
1193 clk_core_disable(core);
1194 clk_core_disable(parent);
1195 clk_enable_unlock(flags);
1196 clk_core_unprepare(parent);
1201 __clk_set_parent_after(core, parent, old_parent);
1207 * __clk_speculate_rates
1208 * @core: first clk in the subtree
1209 * @parent_rate: the "future" rate of clk's parent
1211 * Walks the subtree of clks starting with clk, speculating rates as it
1212 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1214 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1215 * pre-rate change notifications and returns early if no clks in the
1216 * subtree have subscribed to the notifications. Note that if a clk does not
1217 * implement the .recalc_rate callback then it is assumed that the clock will
1218 * take on the rate of its parent.
1220 static int __clk_speculate_rates(struct clk_core *core,
1221 unsigned long parent_rate)
1223 struct clk_core *child;
1224 unsigned long new_rate;
1225 int ret = NOTIFY_DONE;
1227 lockdep_assert_held(&prepare_lock);
1229 new_rate = clk_recalc(core, parent_rate);
1231 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1232 if (core->notifier_count)
1233 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
1235 if (ret & NOTIFY_STOP_MASK) {
1236 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1237 __func__, core->name, ret);
1241 hlist_for_each_entry(child, &core->children, child_node) {
1242 ret = __clk_speculate_rates(child, new_rate);
1243 if (ret & NOTIFY_STOP_MASK)
1251 static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
1252 struct clk_core *new_parent, u8 p_index)
1254 struct clk_core *child;
1256 core->new_rate = new_rate;
1257 core->new_parent = new_parent;
1258 core->new_parent_index = p_index;
1259 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1260 core->new_child = NULL;
1261 if (new_parent && new_parent != core->parent)
1262 new_parent->new_child = core;
1264 hlist_for_each_entry(child, &core->children, child_node) {
1265 child->new_rate = clk_recalc(child, new_rate);
1266 clk_calc_subtree(child, child->new_rate, NULL, 0);
1271 * calculate the new rates returning the topmost clock that has to be
1274 static struct clk_core *clk_calc_new_rates(struct clk_core *core,
1277 struct clk_core *top = core;
1278 struct clk_core *old_parent, *parent;
1279 unsigned long best_parent_rate = 0;
1280 unsigned long new_rate;
1281 unsigned long min_rate;
1282 unsigned long max_rate;
1287 if (IS_ERR_OR_NULL(core))
1290 /* save parent rate, if it exists */
1291 parent = old_parent = core->parent;
1293 best_parent_rate = parent->rate;
1295 clk_core_get_boundaries(core, &min_rate, &max_rate);
1297 /* find the closest rate and parent clk/rate */
1298 if (core->ops->determine_rate) {
1299 struct clk_rate_request req;
1302 req.min_rate = min_rate;
1303 req.max_rate = max_rate;
1305 req.best_parent_hw = parent->hw;
1306 req.best_parent_rate = parent->rate;
1308 req.best_parent_hw = NULL;
1309 req.best_parent_rate = 0;
1312 ret = core->ops->determine_rate(core->hw, &req);
1316 best_parent_rate = req.best_parent_rate;
1317 new_rate = req.rate;
1318 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
1319 } else if (core->ops->round_rate) {
1320 ret = core->ops->round_rate(core->hw, rate,
1326 if (new_rate < min_rate || new_rate > max_rate)
1328 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
1329 /* pass-through clock without adjustable parent */
1330 core->new_rate = core->rate;
1333 /* pass-through clock with adjustable parent */
1334 top = clk_calc_new_rates(parent, rate);
1335 new_rate = parent->new_rate;
1339 /* some clocks must be gated to change parent */
1340 if (parent != old_parent &&
1341 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1342 pr_debug("%s: %s not gated but wants to reparent\n",
1343 __func__, core->name);
1347 /* try finding the new parent index */
1348 if (parent && core->num_parents > 1) {
1349 p_index = clk_fetch_parent_index(core, parent);
1351 pr_debug("%s: clk %s can not be parent of clk %s\n",
1352 __func__, parent->name, core->name);
1357 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
1358 best_parent_rate != parent->rate)
1359 top = clk_calc_new_rates(parent, best_parent_rate);
1362 clk_calc_subtree(core, new_rate, parent, p_index);
1368 * Notify about rate changes in a subtree. Always walk down the whole tree
1369 * so that in case of an error we can walk down the whole tree again and
1372 static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
1373 unsigned long event)
1375 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
1376 int ret = NOTIFY_DONE;
1378 if (core->rate == core->new_rate)
1381 if (core->notifier_count) {
1382 ret = __clk_notify(core, event, core->rate, core->new_rate);
1383 if (ret & NOTIFY_STOP_MASK)
1387 hlist_for_each_entry(child, &core->children, child_node) {
1388 /* Skip children who will be reparented to another clock */
1389 if (child->new_parent && child->new_parent != core)
1391 tmp_clk = clk_propagate_rate_change(child, event);
1396 /* handle the new child who might not be in core->children yet */
1397 if (core->new_child) {
1398 tmp_clk = clk_propagate_rate_change(core->new_child, event);
1407 * walk down a subtree and set the new rates notifying the rate
1410 static void clk_change_rate(struct clk_core *core)
1412 struct clk_core *child;
1413 struct hlist_node *tmp;
1414 unsigned long old_rate;
1415 unsigned long best_parent_rate = 0;
1416 bool skip_set_rate = false;
1417 struct clk_core *old_parent;
1419 old_rate = core->rate;
1421 if (core->new_parent)
1422 best_parent_rate = core->new_parent->rate;
1423 else if (core->parent)
1424 best_parent_rate = core->parent->rate;
1426 if (core->new_parent && core->new_parent != core->parent) {
1427 old_parent = __clk_set_parent_before(core, core->new_parent);
1428 trace_clk_set_parent(core, core->new_parent);
1430 if (core->ops->set_rate_and_parent) {
1431 skip_set_rate = true;
1432 core->ops->set_rate_and_parent(core->hw, core->new_rate,
1434 core->new_parent_index);
1435 } else if (core->ops->set_parent) {
1436 core->ops->set_parent(core->hw, core->new_parent_index);
1439 trace_clk_set_parent_complete(core, core->new_parent);
1440 __clk_set_parent_after(core, core->new_parent, old_parent);
1443 trace_clk_set_rate(core, core->new_rate);
1445 if (!skip_set_rate && core->ops->set_rate)
1446 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
1448 trace_clk_set_rate_complete(core, core->new_rate);
1450 core->rate = clk_recalc(core, best_parent_rate);
1452 if (core->notifier_count && old_rate != core->rate)
1453 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
1455 if (core->flags & CLK_RECALC_NEW_RATES)
1456 (void)clk_calc_new_rates(core, core->new_rate);
1459 * Use safe iteration, as change_rate can actually swap parents
1460 * for certain clock types.
1462 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
1463 /* Skip children who will be reparented to another clock */
1464 if (child->new_parent && child->new_parent != core)
1466 clk_change_rate(child);
1469 /* handle the new child who might not be in core->children yet */
1470 if (core->new_child)
1471 clk_change_rate(core->new_child);
1474 static int clk_core_set_rate_nolock(struct clk_core *core,
1475 unsigned long req_rate)
1477 struct clk_core *top, *fail_clk;
1478 unsigned long rate = req_rate;
1484 /* bail early if nothing to do */
1485 if (rate == clk_core_get_rate_nolock(core))
1488 if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count)
1491 /* calculate new rates and get the topmost changed clock */
1492 top = clk_calc_new_rates(core, rate);
1496 /* notify that we are about to change rates */
1497 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
1499 pr_debug("%s: failed to set %s rate\n", __func__,
1501 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
1505 /* change the rates */
1506 clk_change_rate(top);
1508 core->req_rate = req_rate;
1514 * clk_set_rate - specify a new rate for clk
1515 * @clk: the clk whose rate is being changed
1516 * @rate: the new rate for clk
1518 * In the simplest case clk_set_rate will only adjust the rate of clk.
1520 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1521 * propagate up to clk's parent; whether or not this happens depends on the
1522 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1523 * after calling .round_rate then upstream parent propagation is ignored. If
1524 * *parent_rate comes back with a new rate for clk's parent then we propagate
1525 * up to clk's parent and set its rate. Upward propagation will continue
1526 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1527 * .round_rate stops requesting changes to clk's parent_rate.
1529 * Rate changes are accomplished via tree traversal that also recalculates the
1530 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
1532 * Returns 0 on success, -EERROR otherwise.
1534 int clk_set_rate(struct clk *clk, unsigned long rate)
1541 /* prevent racing with updates to the clock topology */
1544 ret = clk_core_set_rate_nolock(clk->core, rate);
1546 clk_prepare_unlock();
1550 EXPORT_SYMBOL_GPL(clk_set_rate);
1553 * clk_set_rate_range - set a rate range for a clock source
1554 * @clk: clock source
1555 * @min: desired minimum clock rate in Hz, inclusive
1556 * @max: desired maximum clock rate in Hz, inclusive
1558 * Returns success (0) or negative errno.
1560 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
1568 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
1569 __func__, clk->core->name, clk->dev_id, clk->con_id,
1576 if (min != clk->min_rate || max != clk->max_rate) {
1577 clk->min_rate = min;
1578 clk->max_rate = max;
1579 ret = clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
1582 clk_prepare_unlock();
1586 EXPORT_SYMBOL_GPL(clk_set_rate_range);
1589 * clk_set_min_rate - set a minimum clock rate for a clock source
1590 * @clk: clock source
1591 * @rate: desired minimum clock rate in Hz, inclusive
1593 * Returns success (0) or negative errno.
1595 int clk_set_min_rate(struct clk *clk, unsigned long rate)
1600 return clk_set_rate_range(clk, rate, clk->max_rate);
1602 EXPORT_SYMBOL_GPL(clk_set_min_rate);
1605 * clk_set_max_rate - set a maximum clock rate for a clock source
1606 * @clk: clock source
1607 * @rate: desired maximum clock rate in Hz, inclusive
1609 * Returns success (0) or negative errno.
1611 int clk_set_max_rate(struct clk *clk, unsigned long rate)
1616 return clk_set_rate_range(clk, clk->min_rate, rate);
1618 EXPORT_SYMBOL_GPL(clk_set_max_rate);
1621 * clk_get_parent - return the parent of a clk
1622 * @clk: the clk whose parent gets returned
1624 * Simply returns clk->parent. Returns NULL if clk is NULL.
1626 struct clk *clk_get_parent(struct clk *clk)
1631 parent = __clk_get_parent(clk);
1632 clk_prepare_unlock();
1636 EXPORT_SYMBOL_GPL(clk_get_parent);
1639 * .get_parent is mandatory for clocks with multiple possible parents. It is
1640 * optional for single-parent clocks. Always call .get_parent if it is
1641 * available and WARN if it is missing for multi-parent clocks.
1643 * For single-parent clocks without .get_parent, first check to see if the
1644 * .parents array exists, and if so use it to avoid an expensive tree
1645 * traversal. If .parents does not exist then walk the tree.
1647 static struct clk_core *__clk_init_parent(struct clk_core *core)
1649 struct clk_core *ret = NULL;
1652 /* handle the trivial cases */
1654 if (!core->num_parents)
1657 if (core->num_parents == 1) {
1658 if (IS_ERR_OR_NULL(core->parent))
1659 core->parent = clk_core_lookup(core->parent_names[0]);
1664 if (!core->ops->get_parent) {
1665 WARN(!core->ops->get_parent,
1666 "%s: multi-parent clocks must implement .get_parent\n",
1672 * Do our best to cache parent clocks in core->parents. This prevents
1673 * unnecessary and expensive lookups. We don't set core->parent here;
1674 * that is done by the calling function.
1677 index = core->ops->get_parent(core->hw);
1681 kcalloc(core->num_parents, sizeof(struct clk *),
1684 ret = clk_core_get_parent_by_index(core, index);
1690 static void clk_core_reparent(struct clk_core *core,
1691 struct clk_core *new_parent)
1693 clk_reparent(core, new_parent);
1694 __clk_recalc_accuracies(core);
1695 __clk_recalc_rates(core, POST_RATE_CHANGE);
1698 void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
1703 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
1707 * clk_has_parent - check if a clock is a possible parent for another
1708 * @clk: clock source
1709 * @parent: parent clock source
1711 * This function can be used in drivers that need to check that a clock can be
1712 * the parent of another without actually changing the parent.
1714 * Returns true if @parent is a possible parent for @clk, false otherwise.
1716 bool clk_has_parent(struct clk *clk, struct clk *parent)
1718 struct clk_core *core, *parent_core;
1721 /* NULL clocks should be nops, so return success if either is NULL. */
1722 if (!clk || !parent)
1726 parent_core = parent->core;
1728 /* Optimize for the case where the parent is already the parent. */
1729 if (core->parent == parent_core)
1732 for (i = 0; i < core->num_parents; i++)
1733 if (strcmp(core->parent_names[i], parent_core->name) == 0)
1738 EXPORT_SYMBOL_GPL(clk_has_parent);
1740 static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent)
1744 unsigned long p_rate = 0;
1749 /* prevent racing with updates to the clock topology */
1752 if (core->parent == parent)
1755 /* verify ops for for multi-parent clks */
1756 if ((core->num_parents > 1) && (!core->ops->set_parent)) {
1761 /* check that we are allowed to re-parent if the clock is in use */
1762 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1767 /* try finding the new parent index */
1769 p_index = clk_fetch_parent_index(core, parent);
1770 p_rate = parent->rate;
1772 pr_debug("%s: clk %s can not be parent of clk %s\n",
1773 __func__, parent->name, core->name);
1779 /* propagate PRE_RATE_CHANGE notifications */
1780 ret = __clk_speculate_rates(core, p_rate);
1782 /* abort if a driver objects */
1783 if (ret & NOTIFY_STOP_MASK)
1786 /* do the re-parent */
1787 ret = __clk_set_parent(core, parent, p_index);
1789 /* propagate rate an accuracy recalculation accordingly */
1791 __clk_recalc_rates(core, ABORT_RATE_CHANGE);
1793 __clk_recalc_rates(core, POST_RATE_CHANGE);
1794 __clk_recalc_accuracies(core);
1798 clk_prepare_unlock();
1804 * clk_set_parent - switch the parent of a mux clk
1805 * @clk: the mux clk whose input we are switching
1806 * @parent: the new input to clk
1808 * Re-parent clk to use parent as its new input source. If clk is in
1809 * prepared state, the clk will get enabled for the duration of this call. If
1810 * that's not acceptable for a specific clk (Eg: the consumer can't handle
1811 * that, the reparenting is glitchy in hardware, etc), use the
1812 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
1814 * After successfully changing clk's parent clk_set_parent will update the
1815 * clk topology, sysfs topology and propagate rate recalculation via
1816 * __clk_recalc_rates.
1818 * Returns 0 on success, -EERROR otherwise.
1820 int clk_set_parent(struct clk *clk, struct clk *parent)
1825 return clk_core_set_parent(clk->core, parent ? parent->core : NULL);
1827 EXPORT_SYMBOL_GPL(clk_set_parent);
1830 * clk_set_phase - adjust the phase shift of a clock signal
1831 * @clk: clock signal source
1832 * @degrees: number of degrees the signal is shifted
1834 * Shifts the phase of a clock signal by the specified
1835 * degrees. Returns 0 on success, -EERROR otherwise.
1837 * This function makes no distinction about the input or reference
1838 * signal that we adjust the clock signal phase against. For example
1839 * phase locked-loop clock signal generators we may shift phase with
1840 * respect to feedback clock signal input, but for other cases the
1841 * clock phase may be shifted with respect to some other, unspecified
1844 * Additionally the concept of phase shift does not propagate through
1845 * the clock tree hierarchy, which sets it apart from clock rates and
1846 * clock accuracy. A parent clock phase attribute does not have an
1847 * impact on the phase attribute of a child clock.
1849 int clk_set_phase(struct clk *clk, int degrees)
1856 /* sanity check degrees */
1863 trace_clk_set_phase(clk->core, degrees);
1865 if (clk->core->ops->set_phase)
1866 ret = clk->core->ops->set_phase(clk->core->hw, degrees);
1868 trace_clk_set_phase_complete(clk->core, degrees);
1871 clk->core->phase = degrees;
1873 clk_prepare_unlock();
1877 EXPORT_SYMBOL_GPL(clk_set_phase);
1879 static int clk_core_get_phase(struct clk_core *core)
1885 clk_prepare_unlock();
1891 * clk_get_phase - return the phase shift of a clock signal
1892 * @clk: clock signal source
1894 * Returns the phase shift of a clock node in degrees, otherwise returns
1897 int clk_get_phase(struct clk *clk)
1902 return clk_core_get_phase(clk->core);
1904 EXPORT_SYMBOL_GPL(clk_get_phase);
1907 * clk_is_match - check if two clk's point to the same hardware clock
1908 * @p: clk compared against q
1909 * @q: clk compared against p
1911 * Returns true if the two struct clk pointers both point to the same hardware
1912 * clock node. Put differently, returns true if struct clk *p and struct clk *q
1913 * share the same struct clk_core object.
1915 * Returns false otherwise. Note that two NULL clks are treated as matching.
1917 bool clk_is_match(const struct clk *p, const struct clk *q)
1919 /* trivial case: identical struct clk's or both NULL */
1923 /* true if clk->core pointers match. Avoid derefing garbage */
1924 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
1925 if (p->core == q->core)
1930 EXPORT_SYMBOL_GPL(clk_is_match);
1932 /*** debugfs support ***/
1934 #ifdef CONFIG_DEBUG_FS
1935 #include <linux/debugfs.h>
1937 static struct dentry *rootdir;
1938 static int inited = 0;
1939 static DEFINE_MUTEX(clk_debug_lock);
1940 static HLIST_HEAD(clk_debug_list);
1942 static struct hlist_head *all_lists[] = {
1948 static struct hlist_head *orphan_list[] = {
1953 static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
1959 seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu %-3d\n",
1961 30 - level * 3, c->name,
1962 c->enable_count, c->prepare_count, clk_core_get_rate(c),
1963 clk_core_get_accuracy(c), clk_core_get_phase(c));
1966 static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
1969 struct clk_core *child;
1974 clk_summary_show_one(s, c, level);
1976 hlist_for_each_entry(child, &c->children, child_node)
1977 clk_summary_show_subtree(s, child, level + 1);
1980 static int clk_summary_show(struct seq_file *s, void *data)
1983 struct hlist_head **lists = (struct hlist_head **)s->private;
1985 seq_puts(s, " clock enable_cnt prepare_cnt rate accuracy phase\n");
1986 seq_puts(s, "----------------------------------------------------------------------------------------\n");
1990 for (; *lists; lists++)
1991 hlist_for_each_entry(c, *lists, child_node)
1992 clk_summary_show_subtree(s, c, 0);
1994 clk_prepare_unlock();
2000 static int clk_summary_open(struct inode *inode, struct file *file)
2002 return single_open(file, clk_summary_show, inode->i_private);
2005 static const struct file_operations clk_summary_fops = {
2006 .open = clk_summary_open,
2008 .llseek = seq_lseek,
2009 .release = single_release,
2012 static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
2017 /* This should be JSON format, i.e. elements separated with a comma */
2018 seq_printf(s, "\"%s\": { ", c->name);
2019 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
2020 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
2021 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate(c));
2022 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c));
2023 seq_printf(s, "\"phase\": %d", clk_core_get_phase(c));
2026 static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
2028 struct clk_core *child;
2033 clk_dump_one(s, c, level);
2035 hlist_for_each_entry(child, &c->children, child_node) {
2037 clk_dump_subtree(s, child, level + 1);
2043 static int clk_dump(struct seq_file *s, void *data)
2046 bool first_node = true;
2047 struct hlist_head **lists = (struct hlist_head **)s->private;
2053 for (; *lists; lists++) {
2054 hlist_for_each_entry(c, *lists, child_node) {
2058 clk_dump_subtree(s, c, 0);
2062 clk_prepare_unlock();
2069 static int clk_dump_open(struct inode *inode, struct file *file)
2071 return single_open(file, clk_dump, inode->i_private);
2074 static const struct file_operations clk_dump_fops = {
2075 .open = clk_dump_open,
2077 .llseek = seq_lseek,
2078 .release = single_release,
2081 static int clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
2086 if (!core || !pdentry) {
2091 d = debugfs_create_dir(core->name, pdentry);
2097 d = debugfs_create_u32("clk_rate", S_IRUGO, core->dentry,
2098 (u32 *)&core->rate);
2102 d = debugfs_create_u32("clk_accuracy", S_IRUGO, core->dentry,
2103 (u32 *)&core->accuracy);
2107 d = debugfs_create_u32("clk_phase", S_IRUGO, core->dentry,
2108 (u32 *)&core->phase);
2112 d = debugfs_create_x32("clk_flags", S_IRUGO, core->dentry,
2113 (u32 *)&core->flags);
2117 d = debugfs_create_u32("clk_prepare_count", S_IRUGO, core->dentry,
2118 (u32 *)&core->prepare_count);
2122 d = debugfs_create_u32("clk_enable_count", S_IRUGO, core->dentry,
2123 (u32 *)&core->enable_count);
2127 d = debugfs_create_u32("clk_notifier_count", S_IRUGO, core->dentry,
2128 (u32 *)&core->notifier_count);
2132 if (core->ops->debug_init) {
2133 ret = core->ops->debug_init(core->hw, core->dentry);
2142 debugfs_remove_recursive(core->dentry);
2143 core->dentry = NULL;
2149 * clk_debug_register - add a clk node to the debugfs clk directory
2150 * @core: the clk being added to the debugfs clk directory
2152 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
2153 * initialized. Otherwise it bails out early since the debugfs clk directory
2154 * will be created lazily by clk_debug_init as part of a late_initcall.
2156 static int clk_debug_register(struct clk_core *core)
2160 mutex_lock(&clk_debug_lock);
2161 hlist_add_head(&core->debug_node, &clk_debug_list);
2166 ret = clk_debug_create_one(core, rootdir);
2168 mutex_unlock(&clk_debug_lock);
2174 * clk_debug_unregister - remove a clk node from the debugfs clk directory
2175 * @core: the clk being removed from the debugfs clk directory
2177 * Dynamically removes a clk and all its child nodes from the
2178 * debugfs clk directory if clk->dentry points to debugfs created by
2179 * clk_debug_register in __clk_init.
2181 static void clk_debug_unregister(struct clk_core *core)
2183 mutex_lock(&clk_debug_lock);
2184 hlist_del_init(&core->debug_node);
2185 debugfs_remove_recursive(core->dentry);
2186 core->dentry = NULL;
2187 mutex_unlock(&clk_debug_lock);
2190 struct dentry *clk_debugfs_add_file(struct clk_hw *hw, char *name, umode_t mode,
2191 void *data, const struct file_operations *fops)
2193 struct dentry *d = NULL;
2195 if (hw->core->dentry)
2196 d = debugfs_create_file(name, mode, hw->core->dentry, data,
2201 EXPORT_SYMBOL_GPL(clk_debugfs_add_file);
2204 * clk_debug_init - lazily populate the debugfs clk directory
2206 * clks are often initialized very early during boot before memory can be
2207 * dynamically allocated and well before debugfs is setup. This function
2208 * populates the debugfs clk directory once at boot-time when we know that
2209 * debugfs is setup. It should only be called once at boot-time, all other clks
2210 * added dynamically will be done so with clk_debug_register.
2212 static int __init clk_debug_init(void)
2214 struct clk_core *core;
2217 rootdir = debugfs_create_dir("clk", NULL);
2222 d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists,
2227 d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists,
2232 d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir,
2233 &orphan_list, &clk_summary_fops);
2237 d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir,
2238 &orphan_list, &clk_dump_fops);
2242 mutex_lock(&clk_debug_lock);
2243 hlist_for_each_entry(core, &clk_debug_list, debug_node)
2244 clk_debug_create_one(core, rootdir);
2247 mutex_unlock(&clk_debug_lock);
2251 late_initcall(clk_debug_init);
2253 static inline int clk_debug_register(struct clk_core *core) { return 0; }
2254 static inline void clk_debug_reparent(struct clk_core *core,
2255 struct clk_core *new_parent)
2258 static inline void clk_debug_unregister(struct clk_core *core)
2264 * __clk_init - initialize the data structures in a struct clk
2265 * @dev: device initializing this clk, placeholder for now
2266 * @clk: clk being initialized
2268 * Initializes the lists in struct clk_core, queries the hardware for the
2269 * parent and rate and sets them both.
2271 static int __clk_init(struct device *dev, struct clk *clk_user)
2274 struct clk_core *orphan;
2275 struct hlist_node *tmp2;
2276 struct clk_core *core;
2282 core = clk_user->core;
2286 /* check to see if a clock with this name is already registered */
2287 if (clk_core_lookup(core->name)) {
2288 pr_debug("%s: clk %s already initialized\n",
2289 __func__, core->name);
2294 /* check that clk_ops are sane. See Documentation/clk.txt */
2295 if (core->ops->set_rate &&
2296 !((core->ops->round_rate || core->ops->determine_rate) &&
2297 core->ops->recalc_rate)) {
2298 pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
2299 __func__, core->name);
2304 if (core->ops->set_parent && !core->ops->get_parent) {
2305 pr_warning("%s: %s must implement .get_parent & .set_parent\n",
2306 __func__, core->name);
2311 if (core->ops->set_rate_and_parent &&
2312 !(core->ops->set_parent && core->ops->set_rate)) {
2313 pr_warn("%s: %s must implement .set_parent & .set_rate\n",
2314 __func__, core->name);
2319 /* throw a WARN if any entries in parent_names are NULL */
2320 for (i = 0; i < core->num_parents; i++)
2321 WARN(!core->parent_names[i],
2322 "%s: invalid NULL in %s's .parent_names\n",
2323 __func__, core->name);
2326 * Allocate an array of struct clk *'s to avoid unnecessary string
2327 * look-ups of clk's possible parents. This can fail for clocks passed
2328 * in to clk_init during early boot; thus any access to core->parents[]
2329 * must always check for a NULL pointer and try to populate it if
2332 * If core->parents is not NULL we skip this entire block. This allows
2333 * for clock drivers to statically initialize core->parents.
2335 if (core->num_parents > 1 && !core->parents) {
2336 core->parents = kcalloc(core->num_parents, sizeof(struct clk *),
2339 * clk_core_lookup returns NULL for parents that have not been
2340 * clk_init'd; thus any access to clk->parents[] must check
2341 * for a NULL pointer. We can always perform lazy lookups for
2342 * missing parents later on.
2345 for (i = 0; i < core->num_parents; i++)
2347 clk_core_lookup(core->parent_names[i]);
2350 core->parent = __clk_init_parent(core);
2353 * Populate core->parent if parent has already been __clk_init'd. If
2354 * parent has not yet been __clk_init'd then place clk in the orphan
2355 * list. If clk has set the CLK_IS_ROOT flag then place it in the root
2358 * Every time a new clk is clk_init'd then we walk the list of orphan
2359 * clocks and re-parent any that are children of the clock currently
2363 hlist_add_head(&core->child_node,
2364 &core->parent->children);
2365 else if (core->flags & CLK_IS_ROOT)
2366 hlist_add_head(&core->child_node, &clk_root_list);
2368 hlist_add_head(&core->child_node, &clk_orphan_list);
2371 * Set clk's accuracy. The preferred method is to use
2372 * .recalc_accuracy. For simple clocks and lazy developers the default
2373 * fallback is to use the parent's accuracy. If a clock doesn't have a
2374 * parent (or is orphaned) then accuracy is set to zero (perfect
2377 if (core->ops->recalc_accuracy)
2378 core->accuracy = core->ops->recalc_accuracy(core->hw,
2379 __clk_get_accuracy(core->parent));
2380 else if (core->parent)
2381 core->accuracy = core->parent->accuracy;
2387 * Since a phase is by definition relative to its parent, just
2388 * query the current clock phase, or just assume it's in phase.
2390 if (core->ops->get_phase)
2391 core->phase = core->ops->get_phase(core->hw);
2396 * Set clk's rate. The preferred method is to use .recalc_rate. For
2397 * simple clocks and lazy developers the default fallback is to use the
2398 * parent's rate. If a clock doesn't have a parent (or is orphaned)
2399 * then rate is set to zero.
2401 if (core->ops->recalc_rate)
2402 rate = core->ops->recalc_rate(core->hw,
2403 clk_core_get_rate_nolock(core->parent));
2404 else if (core->parent)
2405 rate = core->parent->rate;
2408 core->rate = core->req_rate = rate;
2411 * walk the list of orphan clocks and reparent any that are children of
2414 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
2415 if (orphan->num_parents && orphan->ops->get_parent) {
2416 i = orphan->ops->get_parent(orphan->hw);
2417 if (!strcmp(core->name, orphan->parent_names[i]))
2418 clk_core_reparent(orphan, core);
2422 for (i = 0; i < orphan->num_parents; i++)
2423 if (!strcmp(core->name, orphan->parent_names[i])) {
2424 clk_core_reparent(orphan, core);
2430 * optional platform-specific magic
2432 * The .init callback is not used by any of the basic clock types, but
2433 * exists for weird hardware that must perform initialization magic.
2434 * Please consider other ways of solving initialization problems before
2435 * using this callback, as its use is discouraged.
2437 if (core->ops->init)
2438 core->ops->init(core->hw);
2440 kref_init(&core->ref);
2442 clk_prepare_unlock();
2445 clk_debug_register(core);
2450 struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,
2455 /* This is to allow this function to be chained to others */
2456 if (!hw || IS_ERR(hw))
2457 return (struct clk *) hw;
2459 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
2461 return ERR_PTR(-ENOMEM);
2463 clk->core = hw->core;
2464 clk->dev_id = dev_id;
2465 clk->con_id = con_id;
2466 clk->max_rate = ULONG_MAX;
2469 hlist_add_head(&clk->clks_node, &hw->core->clks);
2470 clk_prepare_unlock();
2475 void __clk_free_clk(struct clk *clk)
2478 hlist_del(&clk->clks_node);
2479 clk_prepare_unlock();
2485 * clk_register - allocate a new clock, register it and return an opaque cookie
2486 * @dev: device that is registering this clock
2487 * @hw: link to hardware-specific clock data
2489 * clk_register is the primary interface for populating the clock tree with new
2490 * clock nodes. It returns a pointer to the newly allocated struct clk which
2491 * cannot be dereferenced by driver code but may be used in conjunction with the
2492 * rest of the clock API. In the event of an error clk_register will return an
2493 * error code; drivers must test for an error code after calling clk_register.
2495 struct clk *clk_register(struct device *dev, struct clk_hw *hw)
2498 struct clk_core *core;
2500 core = kzalloc(sizeof(*core), GFP_KERNEL);
2506 core->name = kstrdup_const(hw->init->name, GFP_KERNEL);
2511 core->ops = hw->init->ops;
2512 if (dev && dev->driver)
2513 core->owner = dev->driver->owner;
2515 core->flags = hw->init->flags;
2516 core->num_parents = hw->init->num_parents;
2518 core->max_rate = ULONG_MAX;
2521 /* allocate local copy in case parent_names is __initdata */
2522 core->parent_names = kcalloc(core->num_parents, sizeof(char *),
2525 if (!core->parent_names) {
2527 goto fail_parent_names;
2531 /* copy each string name in case parent_names is __initdata */
2532 for (i = 0; i < core->num_parents; i++) {
2533 core->parent_names[i] = kstrdup_const(hw->init->parent_names[i],
2535 if (!core->parent_names[i]) {
2537 goto fail_parent_names_copy;
2541 INIT_HLIST_HEAD(&core->clks);
2543 hw->clk = __clk_create_clk(hw, NULL, NULL);
2544 if (IS_ERR(hw->clk)) {
2545 ret = PTR_ERR(hw->clk);
2546 goto fail_parent_names_copy;
2549 ret = __clk_init(dev, hw->clk);
2553 __clk_free_clk(hw->clk);
2556 fail_parent_names_copy:
2558 kfree_const(core->parent_names[i]);
2559 kfree(core->parent_names);
2561 kfree_const(core->name);
2565 return ERR_PTR(ret);
2567 EXPORT_SYMBOL_GPL(clk_register);
2569 /* Free memory allocated for a clock. */
2570 static void __clk_release(struct kref *ref)
2572 struct clk_core *core = container_of(ref, struct clk_core, ref);
2573 int i = core->num_parents;
2575 lockdep_assert_held(&prepare_lock);
2577 kfree(core->parents);
2579 kfree_const(core->parent_names[i]);
2581 kfree(core->parent_names);
2582 kfree_const(core->name);
2587 * Empty clk_ops for unregistered clocks. These are used temporarily
2588 * after clk_unregister() was called on a clock and until last clock
2589 * consumer calls clk_put() and the struct clk object is freed.
2591 static int clk_nodrv_prepare_enable(struct clk_hw *hw)
2596 static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
2601 static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
2602 unsigned long parent_rate)
2607 static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
2612 static const struct clk_ops clk_nodrv_ops = {
2613 .enable = clk_nodrv_prepare_enable,
2614 .disable = clk_nodrv_disable_unprepare,
2615 .prepare = clk_nodrv_prepare_enable,
2616 .unprepare = clk_nodrv_disable_unprepare,
2617 .set_rate = clk_nodrv_set_rate,
2618 .set_parent = clk_nodrv_set_parent,
2622 * clk_unregister - unregister a currently registered clock
2623 * @clk: clock to unregister
2625 void clk_unregister(struct clk *clk)
2627 unsigned long flags;
2629 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2632 clk_debug_unregister(clk->core);
2636 if (clk->core->ops == &clk_nodrv_ops) {
2637 pr_err("%s: unregistered clock: %s\n", __func__,
2642 * Assign empty clock ops for consumers that might still hold
2643 * a reference to this clock.
2645 flags = clk_enable_lock();
2646 clk->core->ops = &clk_nodrv_ops;
2647 clk_enable_unlock(flags);
2649 if (!hlist_empty(&clk->core->children)) {
2650 struct clk_core *child;
2651 struct hlist_node *t;
2653 /* Reparent all children to the orphan list. */
2654 hlist_for_each_entry_safe(child, t, &clk->core->children,
2656 clk_core_set_parent(child, NULL);
2659 hlist_del_init(&clk->core->child_node);
2661 if (clk->core->prepare_count)
2662 pr_warn("%s: unregistering prepared clock: %s\n",
2663 __func__, clk->core->name);
2664 kref_put(&clk->core->ref, __clk_release);
2666 clk_prepare_unlock();
2668 EXPORT_SYMBOL_GPL(clk_unregister);
2670 static void devm_clk_release(struct device *dev, void *res)
2672 clk_unregister(*(struct clk **)res);
2676 * devm_clk_register - resource managed clk_register()
2677 * @dev: device that is registering this clock
2678 * @hw: link to hardware-specific clock data
2680 * Managed clk_register(). Clocks returned from this function are
2681 * automatically clk_unregister()ed on driver detach. See clk_register() for
2684 struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
2689 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
2691 return ERR_PTR(-ENOMEM);
2693 clk = clk_register(dev, hw);
2696 devres_add(dev, clkp);
2703 EXPORT_SYMBOL_GPL(devm_clk_register);
2705 static int devm_clk_match(struct device *dev, void *res, void *data)
2707 struct clk *c = res;
2714 * devm_clk_unregister - resource managed clk_unregister()
2715 * @clk: clock to unregister
2717 * Deallocate a clock allocated with devm_clk_register(). Normally
2718 * this function will not need to be called and the resource management
2719 * code will ensure that the resource is freed.
2721 void devm_clk_unregister(struct device *dev, struct clk *clk)
2723 WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
2725 EXPORT_SYMBOL_GPL(devm_clk_unregister);
2730 int __clk_get(struct clk *clk)
2732 struct clk_core *core = !clk ? NULL : clk->core;
2735 if (!try_module_get(core->owner))
2738 kref_get(&core->ref);
2743 void __clk_put(struct clk *clk)
2745 struct module *owner;
2747 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2752 hlist_del(&clk->clks_node);
2753 if (clk->min_rate > clk->core->req_rate ||
2754 clk->max_rate < clk->core->req_rate)
2755 clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
2757 owner = clk->core->owner;
2758 kref_put(&clk->core->ref, __clk_release);
2760 clk_prepare_unlock();
2767 /*** clk rate change notifiers ***/
2770 * clk_notifier_register - add a clk rate change notifier
2771 * @clk: struct clk * to watch
2772 * @nb: struct notifier_block * with callback info
2774 * Request notification when clk's rate changes. This uses an SRCU
2775 * notifier because we want it to block and notifier unregistrations are
2776 * uncommon. The callbacks associated with the notifier must not
2777 * re-enter into the clk framework by calling any top-level clk APIs;
2778 * this will cause a nested prepare_lock mutex.
2780 * In all notification cases cases (pre, post and abort rate change) the
2781 * original clock rate is passed to the callback via struct
2782 * clk_notifier_data.old_rate and the new frequency is passed via struct
2783 * clk_notifier_data.new_rate.
2785 * clk_notifier_register() must be called from non-atomic context.
2786 * Returns -EINVAL if called with null arguments, -ENOMEM upon
2787 * allocation failure; otherwise, passes along the return value of
2788 * srcu_notifier_chain_register().
2790 int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
2792 struct clk_notifier *cn;
2800 /* search the list of notifiers for this clk */
2801 list_for_each_entry(cn, &clk_notifier_list, node)
2805 /* if clk wasn't in the notifier list, allocate new clk_notifier */
2806 if (cn->clk != clk) {
2807 cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL);
2812 srcu_init_notifier_head(&cn->notifier_head);
2814 list_add(&cn->node, &clk_notifier_list);
2817 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
2819 clk->core->notifier_count++;
2822 clk_prepare_unlock();
2826 EXPORT_SYMBOL_GPL(clk_notifier_register);
2829 * clk_notifier_unregister - remove a clk rate change notifier
2830 * @clk: struct clk *
2831 * @nb: struct notifier_block * with callback info
2833 * Request no further notification for changes to 'clk' and frees memory
2834 * allocated in clk_notifier_register.
2836 * Returns -EINVAL if called with null arguments; otherwise, passes
2837 * along the return value of srcu_notifier_chain_unregister().
2839 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
2841 struct clk_notifier *cn = NULL;
2849 list_for_each_entry(cn, &clk_notifier_list, node)
2853 if (cn->clk == clk) {
2854 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
2856 clk->core->notifier_count--;
2858 /* XXX the notifier code should handle this better */
2859 if (!cn->notifier_head.head) {
2860 srcu_cleanup_notifier_head(&cn->notifier_head);
2861 list_del(&cn->node);
2869 clk_prepare_unlock();
2873 EXPORT_SYMBOL_GPL(clk_notifier_unregister);
2877 * struct of_clk_provider - Clock provider registration structure
2878 * @link: Entry in global list of clock providers
2879 * @node: Pointer to device tree node of clock provider
2880 * @get: Get clock callback. Returns NULL or a struct clk for the
2881 * given clock specifier
2882 * @data: context pointer to be passed into @get callback
2884 struct of_clk_provider {
2885 struct list_head link;
2887 struct device_node *node;
2888 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
2892 static const struct of_device_id __clk_of_table_sentinel
2893 __used __section(__clk_of_table_end);
2895 static LIST_HEAD(of_clk_providers);
2896 static DEFINE_MUTEX(of_clk_mutex);
2898 struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
2903 EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
2905 struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
2907 struct clk_onecell_data *clk_data = data;
2908 unsigned int idx = clkspec->args[0];
2910 if (idx >= clk_data->clk_num) {
2911 pr_err("%s: invalid clock index %d\n", __func__, idx);
2912 return ERR_PTR(-EINVAL);
2915 return clk_data->clks[idx];
2917 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
2920 * of_clk_add_provider() - Register a clock provider for a node
2921 * @np: Device node pointer associated with clock provider
2922 * @clk_src_get: callback for decoding clock
2923 * @data: context pointer for @clk_src_get callback.
2925 int of_clk_add_provider(struct device_node *np,
2926 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
2930 struct of_clk_provider *cp;
2933 cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL);
2937 cp->node = of_node_get(np);
2939 cp->get = clk_src_get;
2941 mutex_lock(&of_clk_mutex);
2942 list_add(&cp->link, &of_clk_providers);
2943 mutex_unlock(&of_clk_mutex);
2944 pr_debug("Added clock from %s\n", np->full_name);
2946 ret = of_clk_set_defaults(np, true);
2948 of_clk_del_provider(np);
2952 EXPORT_SYMBOL_GPL(of_clk_add_provider);
2955 * of_clk_del_provider() - Remove a previously registered clock provider
2956 * @np: Device node pointer associated with clock provider
2958 void of_clk_del_provider(struct device_node *np)
2960 struct of_clk_provider *cp;
2962 mutex_lock(&of_clk_mutex);
2963 list_for_each_entry(cp, &of_clk_providers, link) {
2964 if (cp->node == np) {
2965 list_del(&cp->link);
2966 of_node_put(cp->node);
2971 mutex_unlock(&of_clk_mutex);
2973 EXPORT_SYMBOL_GPL(of_clk_del_provider);
2975 struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec,
2976 const char *dev_id, const char *con_id)
2978 struct of_clk_provider *provider;
2979 struct clk *clk = ERR_PTR(-EPROBE_DEFER);
2982 return ERR_PTR(-EINVAL);
2984 /* Check if we have such a provider in our array */
2985 mutex_lock(&of_clk_mutex);
2986 list_for_each_entry(provider, &of_clk_providers, link) {
2987 if (provider->node == clkspec->np)
2988 clk = provider->get(clkspec, provider->data);
2990 clk = __clk_create_clk(__clk_get_hw(clk), dev_id,
2993 if (!IS_ERR(clk) && !__clk_get(clk)) {
2994 __clk_free_clk(clk);
2995 clk = ERR_PTR(-ENOENT);
3001 mutex_unlock(&of_clk_mutex);
3007 * of_clk_get_from_provider() - Lookup a clock from a clock provider
3008 * @clkspec: pointer to a clock specifier data structure
3010 * This function looks up a struct clk from the registered list of clock
3011 * providers, an input is a clock specifier data structure as returned
3012 * from the of_parse_phandle_with_args() function call.
3014 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
3016 return __of_clk_get_from_provider(clkspec, NULL, __func__);
3019 int of_clk_get_parent_count(struct device_node *np)
3021 return of_count_phandle_with_args(np, "clocks", "#clock-cells");
3023 EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
3025 const char *of_clk_get_parent_name(struct device_node *np, int index)
3027 struct of_phandle_args clkspec;
3028 struct property *prop;
3029 const char *clk_name;
3038 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
3043 index = clkspec.args_count ? clkspec.args[0] : 0;
3046 /* if there is an indices property, use it to transfer the index
3047 * specified into an array offset for the clock-output-names property.
3049 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
3057 if (of_property_read_string_index(clkspec.np, "clock-output-names",
3060 clk_name = clkspec.np->name;
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 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
3155 list_for_each_entry_safe(clk_provider, next,
3156 &clk_provider_list, node) {
3157 list_del(&clk_provider->node);
3158 kfree(clk_provider);
3163 parent->clk_init_cb = match->data;
3165 list_add_tail(&parent->node, &clk_provider_list);
3168 while (!list_empty(&clk_provider_list)) {
3169 is_init_done = false;
3170 list_for_each_entry_safe(clk_provider, next,
3171 &clk_provider_list, node) {
3172 if (force || parent_ready(clk_provider->np)) {
3174 clk_provider->clk_init_cb(clk_provider->np);
3175 of_clk_set_defaults(clk_provider->np, true);
3177 list_del(&clk_provider->node);
3178 kfree(clk_provider);
3179 is_init_done = true;
3184 * We didn't manage to initialize any of the
3185 * remaining providers during the last loop, so now we
3186 * initialize all the remaining ones unconditionally
3187 * in case the clock parent was not mandatory