2 * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
3 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * Standard functionality for the common clock API. See Documentation/clk.txt
12 #include <linux/clk-provider.h>
13 #include <linux/clk/clk-conf.h>
14 #include <linux/module.h>
15 #include <linux/mutex.h>
16 #include <linux/spinlock.h>
17 #include <linux/err.h>
18 #include <linux/list.h>
19 #include <linux/slab.h>
21 #include <linux/device.h>
22 #include <linux/init.h>
23 #include <linux/sched.h>
24 #include <linux/clkdev.h>
28 static DEFINE_SPINLOCK(enable_lock);
29 static DEFINE_MUTEX(prepare_lock);
31 static struct task_struct *prepare_owner;
32 static struct task_struct *enable_owner;
34 static int prepare_refcnt;
35 static int enable_refcnt;
37 static HLIST_HEAD(clk_root_list);
38 static HLIST_HEAD(clk_orphan_list);
39 static LIST_HEAD(clk_notifier_list);
41 /*** private data structures ***/
45 const struct clk_ops *ops;
48 struct clk_core *parent;
49 const char **parent_names;
50 struct clk_core **parents;
54 unsigned long req_rate;
55 unsigned long new_rate;
56 struct clk_core *new_parent;
57 struct clk_core *new_child;
59 unsigned int enable_count;
60 unsigned int prepare_count;
61 unsigned long accuracy;
63 struct hlist_head children;
64 struct hlist_node child_node;
65 struct hlist_head clks;
66 unsigned int notifier_count;
67 #ifdef CONFIG_DEBUG_FS
68 struct dentry *dentry;
69 struct hlist_node debug_node;
74 #define CREATE_TRACE_POINTS
75 #include <trace/events/clk.h>
78 struct clk_core *core;
81 unsigned long min_rate;
82 unsigned long max_rate;
83 struct hlist_node clks_node;
87 static void clk_prepare_lock(void)
89 if (!mutex_trylock(&prepare_lock)) {
90 if (prepare_owner == current) {
94 mutex_lock(&prepare_lock);
96 WARN_ON_ONCE(prepare_owner != NULL);
97 WARN_ON_ONCE(prepare_refcnt != 0);
98 prepare_owner = current;
102 static void clk_prepare_unlock(void)
104 WARN_ON_ONCE(prepare_owner != current);
105 WARN_ON_ONCE(prepare_refcnt == 0);
107 if (--prepare_refcnt)
109 prepare_owner = NULL;
110 mutex_unlock(&prepare_lock);
113 static unsigned long clk_enable_lock(void)
117 if (!spin_trylock_irqsave(&enable_lock, flags)) {
118 if (enable_owner == current) {
122 spin_lock_irqsave(&enable_lock, flags);
124 WARN_ON_ONCE(enable_owner != NULL);
125 WARN_ON_ONCE(enable_refcnt != 0);
126 enable_owner = current;
131 static void clk_enable_unlock(unsigned long flags)
133 WARN_ON_ONCE(enable_owner != current);
134 WARN_ON_ONCE(enable_refcnt == 0);
139 spin_unlock_irqrestore(&enable_lock, flags);
142 static bool clk_core_is_prepared(struct clk_core *core)
145 * .is_prepared is optional for clocks that can prepare
146 * fall back to software usage counter if it is missing
148 if (!core->ops->is_prepared)
149 return core->prepare_count;
151 return core->ops->is_prepared(core->hw);
154 static bool clk_core_is_enabled(struct clk_core *core)
157 * .is_enabled is only mandatory for clocks that gate
158 * fall back to software usage counter if .is_enabled is missing
160 if (!core->ops->is_enabled)
161 return core->enable_count;
163 return core->ops->is_enabled(core->hw);
166 static void clk_unprepare_unused_subtree(struct clk_core *core)
168 struct clk_core *child;
170 lockdep_assert_held(&prepare_lock);
172 hlist_for_each_entry(child, &core->children, child_node)
173 clk_unprepare_unused_subtree(child);
175 if (core->prepare_count)
178 if (core->flags & CLK_IGNORE_UNUSED)
181 if (clk_core_is_prepared(core)) {
182 trace_clk_unprepare(core);
183 if (core->ops->unprepare_unused)
184 core->ops->unprepare_unused(core->hw);
185 else if (core->ops->unprepare)
186 core->ops->unprepare(core->hw);
187 trace_clk_unprepare_complete(core);
191 static void clk_disable_unused_subtree(struct clk_core *core)
193 struct clk_core *child;
196 lockdep_assert_held(&prepare_lock);
198 hlist_for_each_entry(child, &core->children, child_node)
199 clk_disable_unused_subtree(child);
201 flags = clk_enable_lock();
203 if (core->enable_count)
206 if (core->flags & CLK_IGNORE_UNUSED)
210 * some gate clocks have special needs during the disable-unused
211 * sequence. call .disable_unused if available, otherwise fall
214 if (clk_core_is_enabled(core)) {
215 trace_clk_disable(core);
216 if (core->ops->disable_unused)
217 core->ops->disable_unused(core->hw);
218 else if (core->ops->disable)
219 core->ops->disable(core->hw);
220 trace_clk_disable_complete(core);
224 clk_enable_unlock(flags);
227 static bool clk_ignore_unused;
228 static int __init clk_ignore_unused_setup(char *__unused)
230 clk_ignore_unused = true;
233 __setup("clk_ignore_unused", clk_ignore_unused_setup);
235 static int clk_disable_unused(void)
237 struct clk_core *core;
239 if (clk_ignore_unused) {
240 pr_warn("clk: Not disabling unused clocks\n");
246 hlist_for_each_entry(core, &clk_root_list, child_node)
247 clk_disable_unused_subtree(core);
249 hlist_for_each_entry(core, &clk_orphan_list, child_node)
250 clk_disable_unused_subtree(core);
252 hlist_for_each_entry(core, &clk_root_list, child_node)
253 clk_unprepare_unused_subtree(core);
255 hlist_for_each_entry(core, &clk_orphan_list, child_node)
256 clk_unprepare_unused_subtree(core);
258 clk_prepare_unlock();
262 late_initcall_sync(clk_disable_unused);
264 /*** helper functions ***/
266 const char *__clk_get_name(struct clk *clk)
268 return !clk ? NULL : clk->core->name;
270 EXPORT_SYMBOL_GPL(__clk_get_name);
272 struct clk_hw *__clk_get_hw(struct clk *clk)
274 return !clk ? NULL : clk->core->hw;
276 EXPORT_SYMBOL_GPL(__clk_get_hw);
278 u8 __clk_get_num_parents(struct clk *clk)
280 return !clk ? 0 : clk->core->num_parents;
282 EXPORT_SYMBOL_GPL(__clk_get_num_parents);
284 struct clk *__clk_get_parent(struct clk *clk)
289 /* TODO: Create a per-user clk and change callers to call clk_put */
290 return !clk->core->parent ? NULL : clk->core->parent->hw->clk;
292 EXPORT_SYMBOL_GPL(__clk_get_parent);
294 static struct clk_core *__clk_lookup_subtree(const char *name,
295 struct clk_core *core)
297 struct clk_core *child;
298 struct clk_core *ret;
300 if (!strcmp(core->name, name))
303 hlist_for_each_entry(child, &core->children, child_node) {
304 ret = __clk_lookup_subtree(name, child);
312 static struct clk_core *clk_core_lookup(const char *name)
314 struct clk_core *root_clk;
315 struct clk_core *ret;
320 /* search the 'proper' clk tree first */
321 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
322 ret = __clk_lookup_subtree(name, root_clk);
327 /* if not found, then search the orphan tree */
328 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
329 ret = __clk_lookup_subtree(name, root_clk);
337 static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
340 if (!core || index >= core->num_parents)
342 else if (!core->parents)
343 return clk_core_lookup(core->parent_names[index]);
344 else if (!core->parents[index])
345 return core->parents[index] =
346 clk_core_lookup(core->parent_names[index]);
348 return core->parents[index];
351 struct clk *clk_get_parent_by_index(struct clk *clk, u8 index)
353 struct clk_core *parent;
358 parent = clk_core_get_parent_by_index(clk->core, index);
360 return !parent ? NULL : parent->hw->clk;
362 EXPORT_SYMBOL_GPL(clk_get_parent_by_index);
364 unsigned int __clk_get_enable_count(struct clk *clk)
366 return !clk ? 0 : clk->core->enable_count;
369 static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
380 if (core->flags & CLK_IS_ROOT)
390 unsigned long __clk_get_rate(struct clk *clk)
395 return clk_core_get_rate_nolock(clk->core);
397 EXPORT_SYMBOL_GPL(__clk_get_rate);
399 static unsigned long __clk_get_accuracy(struct clk_core *core)
404 return core->accuracy;
407 unsigned long __clk_get_flags(struct clk *clk)
409 return !clk ? 0 : clk->core->flags;
411 EXPORT_SYMBOL_GPL(__clk_get_flags);
413 bool __clk_is_prepared(struct clk *clk)
418 return clk_core_is_prepared(clk->core);
421 bool __clk_is_enabled(struct clk *clk)
426 return clk_core_is_enabled(clk->core);
428 EXPORT_SYMBOL_GPL(__clk_is_enabled);
430 static bool mux_is_better_rate(unsigned long rate, unsigned long now,
431 unsigned long best, unsigned long flags)
433 if (flags & CLK_MUX_ROUND_CLOSEST)
434 return abs(now - rate) < abs(best - rate);
436 return now <= rate && now > best;
440 clk_mux_determine_rate_flags(struct clk_hw *hw, struct clk_rate_request *req,
443 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
444 int i, num_parents, ret;
445 unsigned long best = 0;
446 struct clk_rate_request parent_req = *req;
448 /* if NO_REPARENT flag set, pass through to current parent */
449 if (core->flags & CLK_SET_RATE_NO_REPARENT) {
450 parent = core->parent;
451 if (core->flags & CLK_SET_RATE_PARENT) {
452 ret = __clk_determine_rate(parent ? parent->hw : NULL,
457 best = parent_req.rate;
459 best = clk_core_get_rate_nolock(parent);
461 best = clk_core_get_rate_nolock(core);
467 /* find the parent that can provide the fastest rate <= rate */
468 num_parents = core->num_parents;
469 for (i = 0; i < num_parents; i++) {
470 parent = clk_core_get_parent_by_index(core, i);
474 if (core->flags & CLK_SET_RATE_PARENT) {
476 ret = __clk_determine_rate(parent->hw, &parent_req);
480 parent_req.rate = clk_core_get_rate_nolock(parent);
483 if (mux_is_better_rate(req->rate, parent_req.rate,
485 best_parent = parent;
486 best = parent_req.rate;
495 req->best_parent_hw = best_parent->hw;
496 req->best_parent_rate = best;
502 struct clk *__clk_lookup(const char *name)
504 struct clk_core *core = clk_core_lookup(name);
506 return !core ? NULL : core->hw->clk;
509 static void clk_core_get_boundaries(struct clk_core *core,
510 unsigned long *min_rate,
511 unsigned long *max_rate)
513 struct clk *clk_user;
516 *max_rate = ULONG_MAX;
518 hlist_for_each_entry(clk_user, &core->clks, clks_node)
519 *min_rate = max(*min_rate, clk_user->min_rate);
521 hlist_for_each_entry(clk_user, &core->clks, clks_node)
522 *max_rate = min(*max_rate, clk_user->max_rate);
526 * Helper for finding best parent to provide a given frequency. This can be used
527 * directly as a determine_rate callback (e.g. for a mux), or from a more
528 * complex clock that may combine a mux with other operations.
530 int __clk_mux_determine_rate(struct clk_hw *hw,
531 struct clk_rate_request *req)
533 return clk_mux_determine_rate_flags(hw, req, 0);
535 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
537 int __clk_mux_determine_rate_closest(struct clk_hw *hw,
538 struct clk_rate_request *req)
540 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
542 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
546 static void clk_core_unprepare(struct clk_core *core)
548 lockdep_assert_held(&prepare_lock);
553 if (WARN_ON(core->prepare_count == 0))
556 if (--core->prepare_count > 0)
559 WARN_ON(core->enable_count > 0);
561 trace_clk_unprepare(core);
563 if (core->ops->unprepare)
564 core->ops->unprepare(core->hw);
566 trace_clk_unprepare_complete(core);
567 clk_core_unprepare(core->parent);
571 * clk_unprepare - undo preparation of a clock source
572 * @clk: the clk being unprepared
574 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
575 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
576 * if the operation may sleep. One example is a clk which is accessed over
577 * I2c. In the complex case a clk gate operation may require a fast and a slow
578 * part. It is this reason that clk_unprepare and clk_disable are not mutually
579 * exclusive. In fact clk_disable must be called before clk_unprepare.
581 void clk_unprepare(struct clk *clk)
583 if (IS_ERR_OR_NULL(clk))
587 clk_core_unprepare(clk->core);
588 clk_prepare_unlock();
590 EXPORT_SYMBOL_GPL(clk_unprepare);
592 static int clk_core_prepare(struct clk_core *core)
596 lockdep_assert_held(&prepare_lock);
601 if (core->prepare_count == 0) {
602 ret = clk_core_prepare(core->parent);
606 trace_clk_prepare(core);
608 if (core->ops->prepare)
609 ret = core->ops->prepare(core->hw);
611 trace_clk_prepare_complete(core);
614 clk_core_unprepare(core->parent);
619 core->prepare_count++;
625 * clk_prepare - prepare a clock source
626 * @clk: the clk being prepared
628 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
629 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
630 * operation may sleep. One example is a clk which is accessed over I2c. In
631 * the complex case a clk ungate operation may require a fast and a slow part.
632 * It is this reason that clk_prepare and clk_enable are not mutually
633 * exclusive. In fact clk_prepare must be called before clk_enable.
634 * Returns 0 on success, -EERROR otherwise.
636 int clk_prepare(struct clk *clk)
644 ret = clk_core_prepare(clk->core);
645 clk_prepare_unlock();
649 EXPORT_SYMBOL_GPL(clk_prepare);
651 static void clk_core_disable(struct clk_core *core)
653 lockdep_assert_held(&enable_lock);
658 if (WARN_ON(core->enable_count == 0))
661 if (--core->enable_count > 0)
664 trace_clk_disable(core);
666 if (core->ops->disable)
667 core->ops->disable(core->hw);
669 trace_clk_disable_complete(core);
671 clk_core_disable(core->parent);
675 * clk_disable - gate a clock
676 * @clk: the clk being gated
678 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
679 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
680 * clk if the operation is fast and will never sleep. One example is a
681 * SoC-internal clk which is controlled via simple register writes. In the
682 * complex case a clk gate operation may require a fast and a slow part. It is
683 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
684 * In fact clk_disable must be called before clk_unprepare.
686 void clk_disable(struct clk *clk)
690 if (IS_ERR_OR_NULL(clk))
693 flags = clk_enable_lock();
694 clk_core_disable(clk->core);
695 clk_enable_unlock(flags);
697 EXPORT_SYMBOL_GPL(clk_disable);
699 static int clk_core_enable(struct clk_core *core)
703 lockdep_assert_held(&enable_lock);
708 if (WARN_ON(core->prepare_count == 0))
711 if (core->enable_count == 0) {
712 ret = clk_core_enable(core->parent);
717 trace_clk_enable(core);
719 if (core->ops->enable)
720 ret = core->ops->enable(core->hw);
722 trace_clk_enable_complete(core);
725 clk_core_disable(core->parent);
730 core->enable_count++;
735 * clk_enable - ungate a clock
736 * @clk: the clk being ungated
738 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
739 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
740 * if the operation will never sleep. One example is a SoC-internal clk which
741 * is controlled via simple register writes. In the complex case a clk ungate
742 * operation may require a fast and a slow part. It is this reason that
743 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
744 * must be called before clk_enable. Returns 0 on success, -EERROR
747 int clk_enable(struct clk *clk)
755 flags = clk_enable_lock();
756 ret = clk_core_enable(clk->core);
757 clk_enable_unlock(flags);
761 EXPORT_SYMBOL_GPL(clk_enable);
763 static int clk_core_round_rate_nolock(struct clk_core *core,
764 struct clk_rate_request *req)
766 struct clk_core *parent;
769 lockdep_assert_held(&prepare_lock);
774 parent = core->parent;
776 req->best_parent_hw = parent->hw;
777 req->best_parent_rate = parent->rate;
779 req->best_parent_hw = NULL;
780 req->best_parent_rate = 0;
783 if (core->ops->determine_rate) {
784 return core->ops->determine_rate(core->hw, req);
785 } else if (core->ops->round_rate) {
786 rate = core->ops->round_rate(core->hw, req->rate,
787 &req->best_parent_rate);
792 } else if (core->flags & CLK_SET_RATE_PARENT) {
793 return clk_core_round_rate_nolock(parent, req);
795 req->rate = core->rate;
802 * __clk_determine_rate - get the closest rate actually supported by a clock
803 * @hw: determine the rate of this clock
805 * @min_rate: returned rate must be greater than this rate
806 * @max_rate: returned rate must be less than this rate
808 * Useful for clk_ops such as .set_rate and .determine_rate.
810 int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
817 return clk_core_round_rate_nolock(hw->core, req);
819 EXPORT_SYMBOL_GPL(__clk_determine_rate);
822 * __clk_round_rate - round the given rate for a clk
823 * @clk: round the rate of this clock
824 * @rate: the rate which is to be rounded
826 * Useful for clk_ops such as .set_rate
828 unsigned long __clk_round_rate(struct clk *clk, unsigned long rate)
830 struct clk_rate_request req;
836 clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
839 ret = clk_core_round_rate_nolock(clk->core, &req);
845 EXPORT_SYMBOL_GPL(__clk_round_rate);
848 * clk_round_rate - round the given rate for a clk
849 * @clk: the clk for which we are rounding a rate
850 * @rate: the rate which is to be rounded
852 * Takes in a rate as input and rounds it to a rate that the clk can actually
853 * use which is then returned. If clk doesn't support round_rate operation
854 * then the parent rate is returned.
856 long clk_round_rate(struct clk *clk, unsigned long rate)
864 ret = __clk_round_rate(clk, rate);
865 clk_prepare_unlock();
869 EXPORT_SYMBOL_GPL(clk_round_rate);
872 * __clk_notify - call clk notifier chain
873 * @core: clk that is changing rate
874 * @msg: clk notifier type (see include/linux/clk.h)
875 * @old_rate: old clk rate
876 * @new_rate: new clk rate
878 * Triggers a notifier call chain on the clk rate-change notification
879 * for 'clk'. Passes a pointer to the struct clk and the previous
880 * and current rates to the notifier callback. Intended to be called by
881 * internal clock code only. Returns NOTIFY_DONE from the last driver
882 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
883 * a driver returns that.
885 static int __clk_notify(struct clk_core *core, unsigned long msg,
886 unsigned long old_rate, unsigned long new_rate)
888 struct clk_notifier *cn;
889 struct clk_notifier_data cnd;
890 int ret = NOTIFY_DONE;
892 cnd.old_rate = old_rate;
893 cnd.new_rate = new_rate;
895 list_for_each_entry(cn, &clk_notifier_list, node) {
896 if (cn->clk->core == core) {
898 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
907 * __clk_recalc_accuracies
908 * @core: first clk in the subtree
910 * Walks the subtree of clks starting with clk and recalculates accuracies as
911 * it goes. Note that if a clk does not implement the .recalc_accuracy
912 * callback then it is assumed that the clock will take on the accuracy of its
915 static void __clk_recalc_accuracies(struct clk_core *core)
917 unsigned long parent_accuracy = 0;
918 struct clk_core *child;
920 lockdep_assert_held(&prepare_lock);
923 parent_accuracy = core->parent->accuracy;
925 if (core->ops->recalc_accuracy)
926 core->accuracy = core->ops->recalc_accuracy(core->hw,
929 core->accuracy = parent_accuracy;
931 hlist_for_each_entry(child, &core->children, child_node)
932 __clk_recalc_accuracies(child);
935 static long clk_core_get_accuracy(struct clk_core *core)
937 unsigned long accuracy;
940 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
941 __clk_recalc_accuracies(core);
943 accuracy = __clk_get_accuracy(core);
944 clk_prepare_unlock();
950 * clk_get_accuracy - return the accuracy of clk
951 * @clk: the clk whose accuracy is being returned
953 * Simply returns the cached accuracy of the clk, unless
954 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
956 * If clk is NULL then returns 0.
958 long clk_get_accuracy(struct clk *clk)
963 return clk_core_get_accuracy(clk->core);
965 EXPORT_SYMBOL_GPL(clk_get_accuracy);
967 static unsigned long clk_recalc(struct clk_core *core,
968 unsigned long parent_rate)
970 if (core->ops->recalc_rate)
971 return core->ops->recalc_rate(core->hw, parent_rate);
977 * @core: first clk in the subtree
978 * @msg: notification type (see include/linux/clk.h)
980 * Walks the subtree of clks starting with clk and recalculates rates as it
981 * goes. Note that if a clk does not implement the .recalc_rate callback then
982 * it is assumed that the clock will take on the rate of its parent.
984 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
987 static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
989 unsigned long old_rate;
990 unsigned long parent_rate = 0;
991 struct clk_core *child;
993 lockdep_assert_held(&prepare_lock);
995 old_rate = core->rate;
998 parent_rate = core->parent->rate;
1000 core->rate = clk_recalc(core, parent_rate);
1003 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1004 * & ABORT_RATE_CHANGE notifiers
1006 if (core->notifier_count && msg)
1007 __clk_notify(core, msg, old_rate, core->rate);
1009 hlist_for_each_entry(child, &core->children, child_node)
1010 __clk_recalc_rates(child, msg);
1013 static unsigned long clk_core_get_rate(struct clk_core *core)
1019 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1020 __clk_recalc_rates(core, 0);
1022 rate = clk_core_get_rate_nolock(core);
1023 clk_prepare_unlock();
1029 * clk_get_rate - return the rate of clk
1030 * @clk: the clk whose rate is being returned
1032 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1033 * is set, which means a recalc_rate will be issued.
1034 * If clk is NULL then returns 0.
1036 unsigned long clk_get_rate(struct clk *clk)
1041 return clk_core_get_rate(clk->core);
1043 EXPORT_SYMBOL_GPL(clk_get_rate);
1045 static int clk_fetch_parent_index(struct clk_core *core,
1046 struct clk_core *parent)
1050 if (!core->parents) {
1051 core->parents = kcalloc(core->num_parents,
1052 sizeof(struct clk *), GFP_KERNEL);
1058 * find index of new parent clock using cached parent ptrs,
1059 * or if not yet cached, use string name comparison and cache
1060 * them now to avoid future calls to clk_core_lookup.
1062 for (i = 0; i < core->num_parents; i++) {
1063 if (core->parents[i] == parent)
1066 if (core->parents[i])
1069 if (!strcmp(core->parent_names[i], parent->name)) {
1070 core->parents[i] = clk_core_lookup(parent->name);
1078 static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1080 hlist_del(&core->child_node);
1083 /* avoid duplicate POST_RATE_CHANGE notifications */
1084 if (new_parent->new_child == core)
1085 new_parent->new_child = NULL;
1087 hlist_add_head(&core->child_node, &new_parent->children);
1089 hlist_add_head(&core->child_node, &clk_orphan_list);
1092 core->parent = new_parent;
1095 static struct clk_core *__clk_set_parent_before(struct clk_core *core,
1096 struct clk_core *parent)
1098 unsigned long flags;
1099 struct clk_core *old_parent = core->parent;
1102 * Migrate prepare state between parents and prevent race with
1105 * If the clock is not prepared, then a race with
1106 * clk_enable/disable() is impossible since we already have the
1107 * prepare lock (future calls to clk_enable() need to be preceded by
1110 * If the clock is prepared, migrate the prepared state to the new
1111 * parent and also protect against a race with clk_enable() by
1112 * forcing the clock and the new parent on. This ensures that all
1113 * future calls to clk_enable() are practically NOPs with respect to
1114 * hardware and software states.
1116 * See also: Comment for clk_set_parent() below.
1118 if (core->prepare_count) {
1119 clk_core_prepare(parent);
1120 flags = clk_enable_lock();
1121 clk_core_enable(parent);
1122 clk_core_enable(core);
1123 clk_enable_unlock(flags);
1126 /* update the clk tree topology */
1127 flags = clk_enable_lock();
1128 clk_reparent(core, parent);
1129 clk_enable_unlock(flags);
1134 static void __clk_set_parent_after(struct clk_core *core,
1135 struct clk_core *parent,
1136 struct clk_core *old_parent)
1138 unsigned long flags;
1141 * Finish the migration of prepare state and undo the changes done
1142 * for preventing a race with clk_enable().
1144 if (core->prepare_count) {
1145 flags = clk_enable_lock();
1146 clk_core_disable(core);
1147 clk_core_disable(old_parent);
1148 clk_enable_unlock(flags);
1149 clk_core_unprepare(old_parent);
1153 static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
1156 unsigned long flags;
1158 struct clk_core *old_parent;
1160 old_parent = __clk_set_parent_before(core, parent);
1162 trace_clk_set_parent(core, parent);
1164 /* change clock input source */
1165 if (parent && core->ops->set_parent)
1166 ret = core->ops->set_parent(core->hw, p_index);
1168 trace_clk_set_parent_complete(core, parent);
1171 flags = clk_enable_lock();
1172 clk_reparent(core, old_parent);
1173 clk_enable_unlock(flags);
1175 if (core->prepare_count) {
1176 flags = clk_enable_lock();
1177 clk_core_disable(core);
1178 clk_core_disable(parent);
1179 clk_enable_unlock(flags);
1180 clk_core_unprepare(parent);
1185 __clk_set_parent_after(core, parent, old_parent);
1191 * __clk_speculate_rates
1192 * @core: first clk in the subtree
1193 * @parent_rate: the "future" rate of clk's parent
1195 * Walks the subtree of clks starting with clk, speculating rates as it
1196 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1198 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1199 * pre-rate change notifications and returns early if no clks in the
1200 * subtree have subscribed to the notifications. Note that if a clk does not
1201 * implement the .recalc_rate callback then it is assumed that the clock will
1202 * take on the rate of its parent.
1204 static int __clk_speculate_rates(struct clk_core *core,
1205 unsigned long parent_rate)
1207 struct clk_core *child;
1208 unsigned long new_rate;
1209 int ret = NOTIFY_DONE;
1211 lockdep_assert_held(&prepare_lock);
1213 new_rate = clk_recalc(core, parent_rate);
1215 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1216 if (core->notifier_count)
1217 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
1219 if (ret & NOTIFY_STOP_MASK) {
1220 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1221 __func__, core->name, ret);
1225 hlist_for_each_entry(child, &core->children, child_node) {
1226 ret = __clk_speculate_rates(child, new_rate);
1227 if (ret & NOTIFY_STOP_MASK)
1235 static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
1236 struct clk_core *new_parent, u8 p_index)
1238 struct clk_core *child;
1240 core->new_rate = new_rate;
1241 core->new_parent = new_parent;
1242 core->new_parent_index = p_index;
1243 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1244 core->new_child = NULL;
1245 if (new_parent && new_parent != core->parent)
1246 new_parent->new_child = core;
1248 hlist_for_each_entry(child, &core->children, child_node) {
1249 child->new_rate = clk_recalc(child, new_rate);
1250 clk_calc_subtree(child, child->new_rate, NULL, 0);
1255 * calculate the new rates returning the topmost clock that has to be
1258 static struct clk_core *clk_calc_new_rates(struct clk_core *core,
1261 struct clk_core *top = core;
1262 struct clk_core *old_parent, *parent;
1263 unsigned long best_parent_rate = 0;
1264 unsigned long new_rate;
1265 unsigned long min_rate;
1266 unsigned long max_rate;
1271 if (IS_ERR_OR_NULL(core))
1274 /* save parent rate, if it exists */
1275 parent = old_parent = core->parent;
1277 best_parent_rate = parent->rate;
1279 clk_core_get_boundaries(core, &min_rate, &max_rate);
1281 /* find the closest rate and parent clk/rate */
1282 if (core->ops->determine_rate) {
1283 struct clk_rate_request req;
1286 req.min_rate = min_rate;
1287 req.max_rate = max_rate;
1289 req.best_parent_hw = parent->hw;
1290 req.best_parent_rate = parent->rate;
1292 req.best_parent_hw = NULL;
1293 req.best_parent_rate = 0;
1296 ret = core->ops->determine_rate(core->hw, &req);
1300 best_parent_rate = req.best_parent_rate;
1301 new_rate = req.rate;
1302 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
1303 } else if (core->ops->round_rate) {
1304 ret = core->ops->round_rate(core->hw, rate,
1310 if (new_rate < min_rate || new_rate > max_rate)
1312 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
1313 /* pass-through clock without adjustable parent */
1314 core->new_rate = core->rate;
1317 /* pass-through clock with adjustable parent */
1318 top = clk_calc_new_rates(parent, rate);
1319 new_rate = parent->new_rate;
1323 /* some clocks must be gated to change parent */
1324 if (parent != old_parent &&
1325 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1326 pr_debug("%s: %s not gated but wants to reparent\n",
1327 __func__, core->name);
1331 /* try finding the new parent index */
1332 if (parent && core->num_parents > 1) {
1333 p_index = clk_fetch_parent_index(core, parent);
1335 pr_debug("%s: clk %s can not be parent of clk %s\n",
1336 __func__, parent->name, core->name);
1341 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
1342 best_parent_rate != parent->rate)
1343 top = clk_calc_new_rates(parent, best_parent_rate);
1346 clk_calc_subtree(core, new_rate, parent, p_index);
1352 * Notify about rate changes in a subtree. Always walk down the whole tree
1353 * so that in case of an error we can walk down the whole tree again and
1356 static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
1357 unsigned long event)
1359 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
1360 int ret = NOTIFY_DONE;
1362 if (core->rate == core->new_rate)
1365 if (core->notifier_count) {
1366 ret = __clk_notify(core, event, core->rate, core->new_rate);
1367 if (ret & NOTIFY_STOP_MASK)
1371 hlist_for_each_entry(child, &core->children, child_node) {
1372 /* Skip children who will be reparented to another clock */
1373 if (child->new_parent && child->new_parent != core)
1375 tmp_clk = clk_propagate_rate_change(child, event);
1380 /* handle the new child who might not be in core->children yet */
1381 if (core->new_child) {
1382 tmp_clk = clk_propagate_rate_change(core->new_child, event);
1391 * walk down a subtree and set the new rates notifying the rate
1394 static void clk_change_rate(struct clk_core *core)
1396 struct clk_core *child;
1397 struct hlist_node *tmp;
1398 unsigned long old_rate;
1399 unsigned long best_parent_rate = 0;
1400 bool skip_set_rate = false;
1401 struct clk_core *old_parent;
1403 old_rate = core->rate;
1405 if (core->new_parent)
1406 best_parent_rate = core->new_parent->rate;
1407 else if (core->parent)
1408 best_parent_rate = core->parent->rate;
1410 if (core->new_parent && core->new_parent != core->parent) {
1411 old_parent = __clk_set_parent_before(core, core->new_parent);
1412 trace_clk_set_parent(core, core->new_parent);
1414 if (core->ops->set_rate_and_parent) {
1415 skip_set_rate = true;
1416 core->ops->set_rate_and_parent(core->hw, core->new_rate,
1418 core->new_parent_index);
1419 } else if (core->ops->set_parent) {
1420 core->ops->set_parent(core->hw, core->new_parent_index);
1423 trace_clk_set_parent_complete(core, core->new_parent);
1424 __clk_set_parent_after(core, core->new_parent, old_parent);
1427 trace_clk_set_rate(core, core->new_rate);
1429 if (!skip_set_rate && core->ops->set_rate)
1430 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
1432 trace_clk_set_rate_complete(core, core->new_rate);
1434 core->rate = clk_recalc(core, best_parent_rate);
1436 if (core->notifier_count && old_rate != core->rate)
1437 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
1439 if (core->flags & CLK_RECALC_NEW_RATES)
1440 (void)clk_calc_new_rates(core, core->new_rate);
1443 * Use safe iteration, as change_rate can actually swap parents
1444 * for certain clock types.
1446 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
1447 /* Skip children who will be reparented to another clock */
1448 if (child->new_parent && child->new_parent != core)
1450 clk_change_rate(child);
1453 /* handle the new child who might not be in core->children yet */
1454 if (core->new_child)
1455 clk_change_rate(core->new_child);
1458 static int clk_core_set_rate_nolock(struct clk_core *core,
1459 unsigned long req_rate)
1461 struct clk_core *top, *fail_clk;
1462 unsigned long rate = req_rate;
1468 /* bail early if nothing to do */
1469 if (rate == clk_core_get_rate_nolock(core))
1472 if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count)
1475 /* calculate new rates and get the topmost changed clock */
1476 top = clk_calc_new_rates(core, rate);
1480 /* notify that we are about to change rates */
1481 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
1483 pr_debug("%s: failed to set %s rate\n", __func__,
1485 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
1489 /* change the rates */
1490 clk_change_rate(top);
1492 core->req_rate = req_rate;
1498 * clk_set_rate - specify a new rate for clk
1499 * @clk: the clk whose rate is being changed
1500 * @rate: the new rate for clk
1502 * In the simplest case clk_set_rate will only adjust the rate of clk.
1504 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1505 * propagate up to clk's parent; whether or not this happens depends on the
1506 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1507 * after calling .round_rate then upstream parent propagation is ignored. If
1508 * *parent_rate comes back with a new rate for clk's parent then we propagate
1509 * up to clk's parent and set its rate. Upward propagation will continue
1510 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1511 * .round_rate stops requesting changes to clk's parent_rate.
1513 * Rate changes are accomplished via tree traversal that also recalculates the
1514 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
1516 * Returns 0 on success, -EERROR otherwise.
1518 int clk_set_rate(struct clk *clk, unsigned long rate)
1525 /* prevent racing with updates to the clock topology */
1528 ret = clk_core_set_rate_nolock(clk->core, rate);
1530 clk_prepare_unlock();
1534 EXPORT_SYMBOL_GPL(clk_set_rate);
1537 * clk_set_rate_range - set a rate range for a clock source
1538 * @clk: clock source
1539 * @min: desired minimum clock rate in Hz, inclusive
1540 * @max: desired maximum clock rate in Hz, inclusive
1542 * Returns success (0) or negative errno.
1544 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
1552 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
1553 __func__, clk->core->name, clk->dev_id, clk->con_id,
1560 if (min != clk->min_rate || max != clk->max_rate) {
1561 clk->min_rate = min;
1562 clk->max_rate = max;
1563 ret = clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
1566 clk_prepare_unlock();
1570 EXPORT_SYMBOL_GPL(clk_set_rate_range);
1573 * clk_set_min_rate - set a minimum clock rate for a clock source
1574 * @clk: clock source
1575 * @rate: desired minimum clock rate in Hz, inclusive
1577 * Returns success (0) or negative errno.
1579 int clk_set_min_rate(struct clk *clk, unsigned long rate)
1584 return clk_set_rate_range(clk, rate, clk->max_rate);
1586 EXPORT_SYMBOL_GPL(clk_set_min_rate);
1589 * clk_set_max_rate - set a maximum clock rate for a clock source
1590 * @clk: clock source
1591 * @rate: desired maximum clock rate in Hz, inclusive
1593 * Returns success (0) or negative errno.
1595 int clk_set_max_rate(struct clk *clk, unsigned long rate)
1600 return clk_set_rate_range(clk, clk->min_rate, rate);
1602 EXPORT_SYMBOL_GPL(clk_set_max_rate);
1605 * clk_get_parent - return the parent of a clk
1606 * @clk: the clk whose parent gets returned
1608 * Simply returns clk->parent. Returns NULL if clk is NULL.
1610 struct clk *clk_get_parent(struct clk *clk)
1615 parent = __clk_get_parent(clk);
1616 clk_prepare_unlock();
1620 EXPORT_SYMBOL_GPL(clk_get_parent);
1623 * .get_parent is mandatory for clocks with multiple possible parents. It is
1624 * optional for single-parent clocks. Always call .get_parent if it is
1625 * available and WARN if it is missing for multi-parent clocks.
1627 * For single-parent clocks without .get_parent, first check to see if the
1628 * .parents array exists, and if so use it to avoid an expensive tree
1629 * traversal. If .parents does not exist then walk the tree.
1631 static struct clk_core *__clk_init_parent(struct clk_core *core)
1633 struct clk_core *ret = NULL;
1636 /* handle the trivial cases */
1638 if (!core->num_parents)
1641 if (core->num_parents == 1) {
1642 if (IS_ERR_OR_NULL(core->parent))
1643 core->parent = clk_core_lookup(core->parent_names[0]);
1648 if (!core->ops->get_parent) {
1649 WARN(!core->ops->get_parent,
1650 "%s: multi-parent clocks must implement .get_parent\n",
1656 * Do our best to cache parent clocks in core->parents. This prevents
1657 * unnecessary and expensive lookups. We don't set core->parent here;
1658 * that is done by the calling function.
1661 index = core->ops->get_parent(core->hw);
1665 kcalloc(core->num_parents, sizeof(struct clk *),
1668 ret = clk_core_get_parent_by_index(core, index);
1674 static void clk_core_reparent(struct clk_core *core,
1675 struct clk_core *new_parent)
1677 clk_reparent(core, new_parent);
1678 __clk_recalc_accuracies(core);
1679 __clk_recalc_rates(core, POST_RATE_CHANGE);
1682 void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
1687 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
1691 * clk_has_parent - check if a clock is a possible parent for another
1692 * @clk: clock source
1693 * @parent: parent clock source
1695 * This function can be used in drivers that need to check that a clock can be
1696 * the parent of another without actually changing the parent.
1698 * Returns true if @parent is a possible parent for @clk, false otherwise.
1700 bool clk_has_parent(struct clk *clk, struct clk *parent)
1702 struct clk_core *core, *parent_core;
1705 /* NULL clocks should be nops, so return success if either is NULL. */
1706 if (!clk || !parent)
1710 parent_core = parent->core;
1712 /* Optimize for the case where the parent is already the parent. */
1713 if (core->parent == parent_core)
1716 for (i = 0; i < core->num_parents; i++)
1717 if (strcmp(core->parent_names[i], parent_core->name) == 0)
1722 EXPORT_SYMBOL_GPL(clk_has_parent);
1724 static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent)
1728 unsigned long p_rate = 0;
1733 /* prevent racing with updates to the clock topology */
1736 if (core->parent == parent)
1739 /* verify ops for for multi-parent clks */
1740 if ((core->num_parents > 1) && (!core->ops->set_parent)) {
1745 /* check that we are allowed to re-parent if the clock is in use */
1746 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1751 /* try finding the new parent index */
1753 p_index = clk_fetch_parent_index(core, parent);
1754 p_rate = parent->rate;
1756 pr_debug("%s: clk %s can not be parent of clk %s\n",
1757 __func__, parent->name, core->name);
1763 /* propagate PRE_RATE_CHANGE notifications */
1764 ret = __clk_speculate_rates(core, p_rate);
1766 /* abort if a driver objects */
1767 if (ret & NOTIFY_STOP_MASK)
1770 /* do the re-parent */
1771 ret = __clk_set_parent(core, parent, p_index);
1773 /* propagate rate an accuracy recalculation accordingly */
1775 __clk_recalc_rates(core, ABORT_RATE_CHANGE);
1777 __clk_recalc_rates(core, POST_RATE_CHANGE);
1778 __clk_recalc_accuracies(core);
1782 clk_prepare_unlock();
1788 * clk_set_parent - switch the parent of a mux clk
1789 * @clk: the mux clk whose input we are switching
1790 * @parent: the new input to clk
1792 * Re-parent clk to use parent as its new input source. If clk is in
1793 * prepared state, the clk will get enabled for the duration of this call. If
1794 * that's not acceptable for a specific clk (Eg: the consumer can't handle
1795 * that, the reparenting is glitchy in hardware, etc), use the
1796 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
1798 * After successfully changing clk's parent clk_set_parent will update the
1799 * clk topology, sysfs topology and propagate rate recalculation via
1800 * __clk_recalc_rates.
1802 * Returns 0 on success, -EERROR otherwise.
1804 int clk_set_parent(struct clk *clk, struct clk *parent)
1809 return clk_core_set_parent(clk->core, parent ? parent->core : NULL);
1811 EXPORT_SYMBOL_GPL(clk_set_parent);
1814 * clk_set_phase - adjust the phase shift of a clock signal
1815 * @clk: clock signal source
1816 * @degrees: number of degrees the signal is shifted
1818 * Shifts the phase of a clock signal by the specified
1819 * degrees. Returns 0 on success, -EERROR otherwise.
1821 * This function makes no distinction about the input or reference
1822 * signal that we adjust the clock signal phase against. For example
1823 * phase locked-loop clock signal generators we may shift phase with
1824 * respect to feedback clock signal input, but for other cases the
1825 * clock phase may be shifted with respect to some other, unspecified
1828 * Additionally the concept of phase shift does not propagate through
1829 * the clock tree hierarchy, which sets it apart from clock rates and
1830 * clock accuracy. A parent clock phase attribute does not have an
1831 * impact on the phase attribute of a child clock.
1833 int clk_set_phase(struct clk *clk, int degrees)
1840 /* sanity check degrees */
1847 trace_clk_set_phase(clk->core, degrees);
1849 if (clk->core->ops->set_phase)
1850 ret = clk->core->ops->set_phase(clk->core->hw, degrees);
1852 trace_clk_set_phase_complete(clk->core, degrees);
1855 clk->core->phase = degrees;
1857 clk_prepare_unlock();
1861 EXPORT_SYMBOL_GPL(clk_set_phase);
1863 static int clk_core_get_phase(struct clk_core *core)
1869 clk_prepare_unlock();
1875 * clk_get_phase - return the phase shift of a clock signal
1876 * @clk: clock signal source
1878 * Returns the phase shift of a clock node in degrees, otherwise returns
1881 int clk_get_phase(struct clk *clk)
1886 return clk_core_get_phase(clk->core);
1888 EXPORT_SYMBOL_GPL(clk_get_phase);
1891 * clk_is_match - check if two clk's point to the same hardware clock
1892 * @p: clk compared against q
1893 * @q: clk compared against p
1895 * Returns true if the two struct clk pointers both point to the same hardware
1896 * clock node. Put differently, returns true if struct clk *p and struct clk *q
1897 * share the same struct clk_core object.
1899 * Returns false otherwise. Note that two NULL clks are treated as matching.
1901 bool clk_is_match(const struct clk *p, const struct clk *q)
1903 /* trivial case: identical struct clk's or both NULL */
1907 /* true if clk->core pointers match. Avoid derefing garbage */
1908 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
1909 if (p->core == q->core)
1914 EXPORT_SYMBOL_GPL(clk_is_match);
1916 /*** debugfs support ***/
1918 #ifdef CONFIG_DEBUG_FS
1919 #include <linux/debugfs.h>
1921 static struct dentry *rootdir;
1922 static int inited = 0;
1923 static DEFINE_MUTEX(clk_debug_lock);
1924 static HLIST_HEAD(clk_debug_list);
1926 static struct hlist_head *all_lists[] = {
1932 static struct hlist_head *orphan_list[] = {
1937 static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
1943 seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu %-3d\n",
1945 30 - level * 3, c->name,
1946 c->enable_count, c->prepare_count, clk_core_get_rate(c),
1947 clk_core_get_accuracy(c), clk_core_get_phase(c));
1950 static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
1953 struct clk_core *child;
1958 clk_summary_show_one(s, c, level);
1960 hlist_for_each_entry(child, &c->children, child_node)
1961 clk_summary_show_subtree(s, child, level + 1);
1964 static int clk_summary_show(struct seq_file *s, void *data)
1967 struct hlist_head **lists = (struct hlist_head **)s->private;
1969 seq_puts(s, " clock enable_cnt prepare_cnt rate accuracy phase\n");
1970 seq_puts(s, "----------------------------------------------------------------------------------------\n");
1974 for (; *lists; lists++)
1975 hlist_for_each_entry(c, *lists, child_node)
1976 clk_summary_show_subtree(s, c, 0);
1978 clk_prepare_unlock();
1984 static int clk_summary_open(struct inode *inode, struct file *file)
1986 return single_open(file, clk_summary_show, inode->i_private);
1989 static const struct file_operations clk_summary_fops = {
1990 .open = clk_summary_open,
1992 .llseek = seq_lseek,
1993 .release = single_release,
1996 static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
2001 /* This should be JSON format, i.e. elements separated with a comma */
2002 seq_printf(s, "\"%s\": { ", c->name);
2003 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
2004 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
2005 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate(c));
2006 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c));
2007 seq_printf(s, "\"phase\": %d", clk_core_get_phase(c));
2010 static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
2012 struct clk_core *child;
2017 clk_dump_one(s, c, level);
2019 hlist_for_each_entry(child, &c->children, child_node) {
2021 clk_dump_subtree(s, child, level + 1);
2027 static int clk_dump(struct seq_file *s, void *data)
2030 bool first_node = true;
2031 struct hlist_head **lists = (struct hlist_head **)s->private;
2037 for (; *lists; lists++) {
2038 hlist_for_each_entry(c, *lists, child_node) {
2042 clk_dump_subtree(s, c, 0);
2046 clk_prepare_unlock();
2053 static int clk_dump_open(struct inode *inode, struct file *file)
2055 return single_open(file, clk_dump, inode->i_private);
2058 static const struct file_operations clk_dump_fops = {
2059 .open = clk_dump_open,
2061 .llseek = seq_lseek,
2062 .release = single_release,
2065 static int clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
2070 if (!core || !pdentry) {
2075 d = debugfs_create_dir(core->name, pdentry);
2081 d = debugfs_create_u32("clk_rate", S_IRUGO, core->dentry,
2082 (u32 *)&core->rate);
2086 d = debugfs_create_u32("clk_accuracy", S_IRUGO, core->dentry,
2087 (u32 *)&core->accuracy);
2091 d = debugfs_create_u32("clk_phase", S_IRUGO, core->dentry,
2092 (u32 *)&core->phase);
2096 d = debugfs_create_x32("clk_flags", S_IRUGO, core->dentry,
2097 (u32 *)&core->flags);
2101 d = debugfs_create_u32("clk_prepare_count", S_IRUGO, core->dentry,
2102 (u32 *)&core->prepare_count);
2106 d = debugfs_create_u32("clk_enable_count", S_IRUGO, core->dentry,
2107 (u32 *)&core->enable_count);
2111 d = debugfs_create_u32("clk_notifier_count", S_IRUGO, core->dentry,
2112 (u32 *)&core->notifier_count);
2116 if (core->ops->debug_init) {
2117 ret = core->ops->debug_init(core->hw, core->dentry);
2126 debugfs_remove_recursive(core->dentry);
2127 core->dentry = NULL;
2133 * clk_debug_register - add a clk node to the debugfs clk directory
2134 * @core: the clk being added to the debugfs clk directory
2136 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
2137 * initialized. Otherwise it bails out early since the debugfs clk directory
2138 * will be created lazily by clk_debug_init as part of a late_initcall.
2140 static int clk_debug_register(struct clk_core *core)
2144 mutex_lock(&clk_debug_lock);
2145 hlist_add_head(&core->debug_node, &clk_debug_list);
2150 ret = clk_debug_create_one(core, rootdir);
2152 mutex_unlock(&clk_debug_lock);
2158 * clk_debug_unregister - remove a clk node from the debugfs clk directory
2159 * @core: the clk being removed from the debugfs clk directory
2161 * Dynamically removes a clk and all its child nodes from the
2162 * debugfs clk directory if clk->dentry points to debugfs created by
2163 * clk_debug_register in __clk_init.
2165 static void clk_debug_unregister(struct clk_core *core)
2167 mutex_lock(&clk_debug_lock);
2168 hlist_del_init(&core->debug_node);
2169 debugfs_remove_recursive(core->dentry);
2170 core->dentry = NULL;
2171 mutex_unlock(&clk_debug_lock);
2174 struct dentry *clk_debugfs_add_file(struct clk_hw *hw, char *name, umode_t mode,
2175 void *data, const struct file_operations *fops)
2177 struct dentry *d = NULL;
2179 if (hw->core->dentry)
2180 d = debugfs_create_file(name, mode, hw->core->dentry, data,
2185 EXPORT_SYMBOL_GPL(clk_debugfs_add_file);
2188 * clk_debug_init - lazily populate the debugfs clk directory
2190 * clks are often initialized very early during boot before memory can be
2191 * dynamically allocated and well before debugfs is setup. This function
2192 * populates the debugfs clk directory once at boot-time when we know that
2193 * debugfs is setup. It should only be called once at boot-time, all other clks
2194 * added dynamically will be done so with clk_debug_register.
2196 static int __init clk_debug_init(void)
2198 struct clk_core *core;
2201 rootdir = debugfs_create_dir("clk", NULL);
2206 d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists,
2211 d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists,
2216 d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir,
2217 &orphan_list, &clk_summary_fops);
2221 d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir,
2222 &orphan_list, &clk_dump_fops);
2226 mutex_lock(&clk_debug_lock);
2227 hlist_for_each_entry(core, &clk_debug_list, debug_node)
2228 clk_debug_create_one(core, rootdir);
2231 mutex_unlock(&clk_debug_lock);
2235 late_initcall(clk_debug_init);
2237 static inline int clk_debug_register(struct clk_core *core) { return 0; }
2238 static inline void clk_debug_reparent(struct clk_core *core,
2239 struct clk_core *new_parent)
2242 static inline void clk_debug_unregister(struct clk_core *core)
2248 * __clk_init - initialize the data structures in a struct clk
2249 * @dev: device initializing this clk, placeholder for now
2250 * @clk: clk being initialized
2252 * Initializes the lists in struct clk_core, queries the hardware for the
2253 * parent and rate and sets them both.
2255 static int __clk_init(struct device *dev, struct clk *clk_user)
2258 struct clk_core *orphan;
2259 struct hlist_node *tmp2;
2260 struct clk_core *core;
2266 core = clk_user->core;
2270 /* check to see if a clock with this name is already registered */
2271 if (clk_core_lookup(core->name)) {
2272 pr_debug("%s: clk %s already initialized\n",
2273 __func__, core->name);
2278 /* check that clk_ops are sane. See Documentation/clk.txt */
2279 if (core->ops->set_rate &&
2280 !((core->ops->round_rate || core->ops->determine_rate) &&
2281 core->ops->recalc_rate)) {
2282 pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
2283 __func__, core->name);
2288 if (core->ops->set_parent && !core->ops->get_parent) {
2289 pr_warning("%s: %s must implement .get_parent & .set_parent\n",
2290 __func__, core->name);
2295 if (core->ops->set_rate_and_parent &&
2296 !(core->ops->set_parent && core->ops->set_rate)) {
2297 pr_warn("%s: %s must implement .set_parent & .set_rate\n",
2298 __func__, core->name);
2303 /* throw a WARN if any entries in parent_names are NULL */
2304 for (i = 0; i < core->num_parents; i++)
2305 WARN(!core->parent_names[i],
2306 "%s: invalid NULL in %s's .parent_names\n",
2307 __func__, core->name);
2310 * Allocate an array of struct clk *'s to avoid unnecessary string
2311 * look-ups of clk's possible parents. This can fail for clocks passed
2312 * in to clk_init during early boot; thus any access to core->parents[]
2313 * must always check for a NULL pointer and try to populate it if
2316 * If core->parents is not NULL we skip this entire block. This allows
2317 * for clock drivers to statically initialize core->parents.
2319 if (core->num_parents > 1 && !core->parents) {
2320 core->parents = kcalloc(core->num_parents, sizeof(struct clk *),
2323 * clk_core_lookup returns NULL for parents that have not been
2324 * clk_init'd; thus any access to clk->parents[] must check
2325 * for a NULL pointer. We can always perform lazy lookups for
2326 * missing parents later on.
2329 for (i = 0; i < core->num_parents; i++)
2331 clk_core_lookup(core->parent_names[i]);
2334 core->parent = __clk_init_parent(core);
2337 * Populate core->parent if parent has already been __clk_init'd. If
2338 * parent has not yet been __clk_init'd then place clk in the orphan
2339 * list. If clk has set the CLK_IS_ROOT flag then place it in the root
2342 * Every time a new clk is clk_init'd then we walk the list of orphan
2343 * clocks and re-parent any that are children of the clock currently
2347 hlist_add_head(&core->child_node,
2348 &core->parent->children);
2349 else if (core->flags & CLK_IS_ROOT)
2350 hlist_add_head(&core->child_node, &clk_root_list);
2352 hlist_add_head(&core->child_node, &clk_orphan_list);
2355 * Set clk's accuracy. The preferred method is to use
2356 * .recalc_accuracy. For simple clocks and lazy developers the default
2357 * fallback is to use the parent's accuracy. If a clock doesn't have a
2358 * parent (or is orphaned) then accuracy is set to zero (perfect
2361 if (core->ops->recalc_accuracy)
2362 core->accuracy = core->ops->recalc_accuracy(core->hw,
2363 __clk_get_accuracy(core->parent));
2364 else if (core->parent)
2365 core->accuracy = core->parent->accuracy;
2371 * Since a phase is by definition relative to its parent, just
2372 * query the current clock phase, or just assume it's in phase.
2374 if (core->ops->get_phase)
2375 core->phase = core->ops->get_phase(core->hw);
2380 * Set clk's rate. The preferred method is to use .recalc_rate. For
2381 * simple clocks and lazy developers the default fallback is to use the
2382 * parent's rate. If a clock doesn't have a parent (or is orphaned)
2383 * then rate is set to zero.
2385 if (core->ops->recalc_rate)
2386 rate = core->ops->recalc_rate(core->hw,
2387 clk_core_get_rate_nolock(core->parent));
2388 else if (core->parent)
2389 rate = core->parent->rate;
2392 core->rate = core->req_rate = rate;
2395 * walk the list of orphan clocks and reparent any that are children of
2398 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
2399 if (orphan->num_parents && orphan->ops->get_parent) {
2400 i = orphan->ops->get_parent(orphan->hw);
2401 if (!strcmp(core->name, orphan->parent_names[i]))
2402 clk_core_reparent(orphan, core);
2406 for (i = 0; i < orphan->num_parents; i++)
2407 if (!strcmp(core->name, orphan->parent_names[i])) {
2408 clk_core_reparent(orphan, core);
2414 * optional platform-specific magic
2416 * The .init callback is not used by any of the basic clock types, but
2417 * exists for weird hardware that must perform initialization magic.
2418 * Please consider other ways of solving initialization problems before
2419 * using this callback, as its use is discouraged.
2421 if (core->ops->init)
2422 core->ops->init(core->hw);
2424 kref_init(&core->ref);
2426 clk_prepare_unlock();
2429 clk_debug_register(core);
2434 struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,
2439 /* This is to allow this function to be chained to others */
2440 if (!hw || IS_ERR(hw))
2441 return (struct clk *) hw;
2443 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
2445 return ERR_PTR(-ENOMEM);
2447 clk->core = hw->core;
2448 clk->dev_id = dev_id;
2449 clk->con_id = con_id;
2450 clk->max_rate = ULONG_MAX;
2453 hlist_add_head(&clk->clks_node, &hw->core->clks);
2454 clk_prepare_unlock();
2459 void __clk_free_clk(struct clk *clk)
2462 hlist_del(&clk->clks_node);
2463 clk_prepare_unlock();
2469 * clk_register - allocate a new clock, register it and return an opaque cookie
2470 * @dev: device that is registering this clock
2471 * @hw: link to hardware-specific clock data
2473 * clk_register is the primary interface for populating the clock tree with new
2474 * clock nodes. It returns a pointer to the newly allocated struct clk which
2475 * cannot be dereferenced by driver code but may be used in conjunction with the
2476 * rest of the clock API. In the event of an error clk_register will return an
2477 * error code; drivers must test for an error code after calling clk_register.
2479 struct clk *clk_register(struct device *dev, struct clk_hw *hw)
2482 struct clk_core *core;
2484 core = kzalloc(sizeof(*core), GFP_KERNEL);
2490 core->name = kstrdup_const(hw->init->name, GFP_KERNEL);
2495 core->ops = hw->init->ops;
2496 if (dev && dev->driver)
2497 core->owner = dev->driver->owner;
2499 core->flags = hw->init->flags;
2500 core->num_parents = hw->init->num_parents;
2503 /* allocate local copy in case parent_names is __initdata */
2504 core->parent_names = kcalloc(core->num_parents, sizeof(char *),
2507 if (!core->parent_names) {
2509 goto fail_parent_names;
2513 /* copy each string name in case parent_names is __initdata */
2514 for (i = 0; i < core->num_parents; i++) {
2515 core->parent_names[i] = kstrdup_const(hw->init->parent_names[i],
2517 if (!core->parent_names[i]) {
2519 goto fail_parent_names_copy;
2523 INIT_HLIST_HEAD(&core->clks);
2525 hw->clk = __clk_create_clk(hw, NULL, NULL);
2526 if (IS_ERR(hw->clk)) {
2527 ret = PTR_ERR(hw->clk);
2528 goto fail_parent_names_copy;
2531 ret = __clk_init(dev, hw->clk);
2535 __clk_free_clk(hw->clk);
2538 fail_parent_names_copy:
2540 kfree_const(core->parent_names[i]);
2541 kfree(core->parent_names);
2543 kfree_const(core->name);
2547 return ERR_PTR(ret);
2549 EXPORT_SYMBOL_GPL(clk_register);
2551 /* Free memory allocated for a clock. */
2552 static void __clk_release(struct kref *ref)
2554 struct clk_core *core = container_of(ref, struct clk_core, ref);
2555 int i = core->num_parents;
2557 lockdep_assert_held(&prepare_lock);
2559 kfree(core->parents);
2561 kfree_const(core->parent_names[i]);
2563 kfree(core->parent_names);
2564 kfree_const(core->name);
2569 * Empty clk_ops for unregistered clocks. These are used temporarily
2570 * after clk_unregister() was called on a clock and until last clock
2571 * consumer calls clk_put() and the struct clk object is freed.
2573 static int clk_nodrv_prepare_enable(struct clk_hw *hw)
2578 static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
2583 static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
2584 unsigned long parent_rate)
2589 static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
2594 static const struct clk_ops clk_nodrv_ops = {
2595 .enable = clk_nodrv_prepare_enable,
2596 .disable = clk_nodrv_disable_unprepare,
2597 .prepare = clk_nodrv_prepare_enable,
2598 .unprepare = clk_nodrv_disable_unprepare,
2599 .set_rate = clk_nodrv_set_rate,
2600 .set_parent = clk_nodrv_set_parent,
2604 * clk_unregister - unregister a currently registered clock
2605 * @clk: clock to unregister
2607 void clk_unregister(struct clk *clk)
2609 unsigned long flags;
2611 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2614 clk_debug_unregister(clk->core);
2618 if (clk->core->ops == &clk_nodrv_ops) {
2619 pr_err("%s: unregistered clock: %s\n", __func__,
2624 * Assign empty clock ops for consumers that might still hold
2625 * a reference to this clock.
2627 flags = clk_enable_lock();
2628 clk->core->ops = &clk_nodrv_ops;
2629 clk_enable_unlock(flags);
2631 if (!hlist_empty(&clk->core->children)) {
2632 struct clk_core *child;
2633 struct hlist_node *t;
2635 /* Reparent all children to the orphan list. */
2636 hlist_for_each_entry_safe(child, t, &clk->core->children,
2638 clk_core_set_parent(child, NULL);
2641 hlist_del_init(&clk->core->child_node);
2643 if (clk->core->prepare_count)
2644 pr_warn("%s: unregistering prepared clock: %s\n",
2645 __func__, clk->core->name);
2646 kref_put(&clk->core->ref, __clk_release);
2648 clk_prepare_unlock();
2650 EXPORT_SYMBOL_GPL(clk_unregister);
2652 static void devm_clk_release(struct device *dev, void *res)
2654 clk_unregister(*(struct clk **)res);
2658 * devm_clk_register - resource managed clk_register()
2659 * @dev: device that is registering this clock
2660 * @hw: link to hardware-specific clock data
2662 * Managed clk_register(). Clocks returned from this function are
2663 * automatically clk_unregister()ed on driver detach. See clk_register() for
2666 struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
2671 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
2673 return ERR_PTR(-ENOMEM);
2675 clk = clk_register(dev, hw);
2678 devres_add(dev, clkp);
2685 EXPORT_SYMBOL_GPL(devm_clk_register);
2687 static int devm_clk_match(struct device *dev, void *res, void *data)
2689 struct clk *c = res;
2696 * devm_clk_unregister - resource managed clk_unregister()
2697 * @clk: clock to unregister
2699 * Deallocate a clock allocated with devm_clk_register(). Normally
2700 * this function will not need to be called and the resource management
2701 * code will ensure that the resource is freed.
2703 void devm_clk_unregister(struct device *dev, struct clk *clk)
2705 WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
2707 EXPORT_SYMBOL_GPL(devm_clk_unregister);
2712 int __clk_get(struct clk *clk)
2714 struct clk_core *core = !clk ? NULL : clk->core;
2717 if (!try_module_get(core->owner))
2720 kref_get(&core->ref);
2725 void __clk_put(struct clk *clk)
2727 struct module *owner;
2729 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2734 hlist_del(&clk->clks_node);
2735 if (clk->min_rate > clk->core->req_rate ||
2736 clk->max_rate < clk->core->req_rate)
2737 clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
2739 owner = clk->core->owner;
2740 kref_put(&clk->core->ref, __clk_release);
2742 clk_prepare_unlock();
2749 /*** clk rate change notifiers ***/
2752 * clk_notifier_register - add a clk rate change notifier
2753 * @clk: struct clk * to watch
2754 * @nb: struct notifier_block * with callback info
2756 * Request notification when clk's rate changes. This uses an SRCU
2757 * notifier because we want it to block and notifier unregistrations are
2758 * uncommon. The callbacks associated with the notifier must not
2759 * re-enter into the clk framework by calling any top-level clk APIs;
2760 * this will cause a nested prepare_lock mutex.
2762 * In all notification cases cases (pre, post and abort rate change) the
2763 * original clock rate is passed to the callback via struct
2764 * clk_notifier_data.old_rate and the new frequency is passed via struct
2765 * clk_notifier_data.new_rate.
2767 * clk_notifier_register() must be called from non-atomic context.
2768 * Returns -EINVAL if called with null arguments, -ENOMEM upon
2769 * allocation failure; otherwise, passes along the return value of
2770 * srcu_notifier_chain_register().
2772 int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
2774 struct clk_notifier *cn;
2782 /* search the list of notifiers for this clk */
2783 list_for_each_entry(cn, &clk_notifier_list, node)
2787 /* if clk wasn't in the notifier list, allocate new clk_notifier */
2788 if (cn->clk != clk) {
2789 cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL);
2794 srcu_init_notifier_head(&cn->notifier_head);
2796 list_add(&cn->node, &clk_notifier_list);
2799 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
2801 clk->core->notifier_count++;
2804 clk_prepare_unlock();
2808 EXPORT_SYMBOL_GPL(clk_notifier_register);
2811 * clk_notifier_unregister - remove a clk rate change notifier
2812 * @clk: struct clk *
2813 * @nb: struct notifier_block * with callback info
2815 * Request no further notification for changes to 'clk' and frees memory
2816 * allocated in clk_notifier_register.
2818 * Returns -EINVAL if called with null arguments; otherwise, passes
2819 * along the return value of srcu_notifier_chain_unregister().
2821 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
2823 struct clk_notifier *cn = NULL;
2831 list_for_each_entry(cn, &clk_notifier_list, node)
2835 if (cn->clk == clk) {
2836 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
2838 clk->core->notifier_count--;
2840 /* XXX the notifier code should handle this better */
2841 if (!cn->notifier_head.head) {
2842 srcu_cleanup_notifier_head(&cn->notifier_head);
2843 list_del(&cn->node);
2851 clk_prepare_unlock();
2855 EXPORT_SYMBOL_GPL(clk_notifier_unregister);
2859 * struct of_clk_provider - Clock provider registration structure
2860 * @link: Entry in global list of clock providers
2861 * @node: Pointer to device tree node of clock provider
2862 * @get: Get clock callback. Returns NULL or a struct clk for the
2863 * given clock specifier
2864 * @data: context pointer to be passed into @get callback
2866 struct of_clk_provider {
2867 struct list_head link;
2869 struct device_node *node;
2870 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
2874 static const struct of_device_id __clk_of_table_sentinel
2875 __used __section(__clk_of_table_end);
2877 static LIST_HEAD(of_clk_providers);
2878 static DEFINE_MUTEX(of_clk_mutex);
2880 struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
2885 EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
2887 struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
2889 struct clk_onecell_data *clk_data = data;
2890 unsigned int idx = clkspec->args[0];
2892 if (idx >= clk_data->clk_num) {
2893 pr_err("%s: invalid clock index %d\n", __func__, idx);
2894 return ERR_PTR(-EINVAL);
2897 return clk_data->clks[idx];
2899 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
2902 * of_clk_add_provider() - Register a clock provider for a node
2903 * @np: Device node pointer associated with clock provider
2904 * @clk_src_get: callback for decoding clock
2905 * @data: context pointer for @clk_src_get callback.
2907 int of_clk_add_provider(struct device_node *np,
2908 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
2912 struct of_clk_provider *cp;
2915 cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL);
2919 cp->node = of_node_get(np);
2921 cp->get = clk_src_get;
2923 mutex_lock(&of_clk_mutex);
2924 list_add(&cp->link, &of_clk_providers);
2925 mutex_unlock(&of_clk_mutex);
2926 pr_debug("Added clock from %s\n", np->full_name);
2928 ret = of_clk_set_defaults(np, true);
2930 of_clk_del_provider(np);
2934 EXPORT_SYMBOL_GPL(of_clk_add_provider);
2937 * of_clk_del_provider() - Remove a previously registered clock provider
2938 * @np: Device node pointer associated with clock provider
2940 void of_clk_del_provider(struct device_node *np)
2942 struct of_clk_provider *cp;
2944 mutex_lock(&of_clk_mutex);
2945 list_for_each_entry(cp, &of_clk_providers, link) {
2946 if (cp->node == np) {
2947 list_del(&cp->link);
2948 of_node_put(cp->node);
2953 mutex_unlock(&of_clk_mutex);
2955 EXPORT_SYMBOL_GPL(of_clk_del_provider);
2957 struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec,
2958 const char *dev_id, const char *con_id)
2960 struct of_clk_provider *provider;
2961 struct clk *clk = ERR_PTR(-EPROBE_DEFER);
2964 return ERR_PTR(-EINVAL);
2966 /* Check if we have such a provider in our array */
2967 mutex_lock(&of_clk_mutex);
2968 list_for_each_entry(provider, &of_clk_providers, link) {
2969 if (provider->node == clkspec->np)
2970 clk = provider->get(clkspec, provider->data);
2972 clk = __clk_create_clk(__clk_get_hw(clk), dev_id,
2975 if (!IS_ERR(clk) && !__clk_get(clk)) {
2976 __clk_free_clk(clk);
2977 clk = ERR_PTR(-ENOENT);
2983 mutex_unlock(&of_clk_mutex);
2989 * of_clk_get_from_provider() - Lookup a clock from a clock provider
2990 * @clkspec: pointer to a clock specifier data structure
2992 * This function looks up a struct clk from the registered list of clock
2993 * providers, an input is a clock specifier data structure as returned
2994 * from the of_parse_phandle_with_args() function call.
2996 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
2998 return __of_clk_get_from_provider(clkspec, NULL, __func__);
3001 int of_clk_get_parent_count(struct device_node *np)
3003 return 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;
3020 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
3025 index = clkspec.args_count ? clkspec.args[0] : 0;
3028 /* if there is an indices property, use it to transfer the index
3029 * specified into an array offset for the clock-output-names property.
3031 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
3039 if (of_property_read_string_index(clkspec.np, "clock-output-names",
3042 clk_name = clkspec.np->name;
3044 of_node_put(clkspec.np);
3047 EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
3050 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
3052 * @np: Device node pointer associated with clock provider
3053 * @parents: pointer to char array that hold the parents' names
3054 * @size: size of the @parents array
3056 * Return: number of parents for the clock node.
3058 int of_clk_parent_fill(struct device_node *np, const char **parents,
3063 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
3068 EXPORT_SYMBOL_GPL(of_clk_parent_fill);
3070 struct clock_provider {
3071 of_clk_init_cb_t clk_init_cb;
3072 struct device_node *np;
3073 struct list_head node;
3077 * This function looks for a parent clock. If there is one, then it
3078 * checks that the provider for this parent clock was initialized, in
3079 * this case the parent clock will be ready.
3081 static int parent_ready(struct device_node *np)
3086 struct clk *clk = of_clk_get(np, i);
3088 /* this parent is ready we can check the next one */
3095 /* at least one parent is not ready, we exit now */
3096 if (PTR_ERR(clk) == -EPROBE_DEFER)
3100 * Here we make assumption that the device tree is
3101 * written correctly. So an error means that there is
3102 * no more parent. As we didn't exit yet, then the
3103 * previous parent are ready. If there is no clock
3104 * parent, no need to wait for them, then we can
3105 * consider their absence as being ready
3112 * of_clk_init() - Scan and init clock providers from the DT
3113 * @matches: array of compatible values and init functions for providers.
3115 * This function scans the device tree for matching clock providers
3116 * and calls their initialization functions. It also does it by trying
3117 * to follow the dependencies.
3119 void __init of_clk_init(const struct of_device_id *matches)
3121 const struct of_device_id *match;
3122 struct device_node *np;
3123 struct clock_provider *clk_provider, *next;
3126 LIST_HEAD(clk_provider_list);
3129 matches = &__clk_of_table;
3131 /* First prepare the list of the clocks providers */
3132 for_each_matching_node_and_match(np, matches, &match) {
3133 struct clock_provider *parent;
3135 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
3137 list_for_each_entry_safe(clk_provider, next,
3138 &clk_provider_list, node) {
3139 list_del(&clk_provider->node);
3140 kfree(clk_provider);
3145 parent->clk_init_cb = match->data;
3147 list_add_tail(&parent->node, &clk_provider_list);
3150 while (!list_empty(&clk_provider_list)) {
3151 is_init_done = false;
3152 list_for_each_entry_safe(clk_provider, next,
3153 &clk_provider_list, node) {
3154 if (force || parent_ready(clk_provider->np)) {
3156 clk_provider->clk_init_cb(clk_provider->np);
3157 of_clk_set_defaults(clk_provider->np, true);
3159 list_del(&clk_provider->node);
3160 kfree(clk_provider);
3161 is_init_done = true;
3166 * We didn't manage to initialize any of the
3167 * remaining providers during the last loop, so now we
3168 * initialize all the remaining ones unconditionally
3169 * in case the clock parent was not mandatory