1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
4 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
6 * Standard functionality for the common clock API. See Documentation/driver-api/clk.rst
10 #include <linux/clk-provider.h>
11 #include <linux/clk/clk-conf.h>
12 #include <linux/module.h>
13 #include <linux/mutex.h>
14 #include <linux/spinlock.h>
15 #include <linux/err.h>
16 #include <linux/list.h>
17 #include <linux/slab.h>
19 #include <linux/device.h>
20 #include <linux/init.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/sched.h>
23 #include <linux/clkdev.h>
27 static DEFINE_SPINLOCK(enable_lock);
28 static DEFINE_MUTEX(prepare_lock);
30 static struct task_struct *prepare_owner;
31 static struct task_struct *enable_owner;
33 static int prepare_refcnt;
34 static int enable_refcnt;
36 static HLIST_HEAD(clk_root_list);
37 static HLIST_HEAD(clk_orphan_list);
38 static LIST_HEAD(clk_notifier_list);
40 static struct hlist_head *all_lists[] = {
46 /*** private data structures ***/
48 struct clk_parent_map {
49 const struct clk_hw *hw;
50 struct clk_core *core;
58 const struct clk_ops *ops;
62 struct device_node *of_node;
63 struct clk_core *parent;
64 struct clk_parent_map *parents;
68 unsigned long req_rate;
69 unsigned long new_rate;
70 struct clk_core *new_parent;
71 struct clk_core *new_child;
75 unsigned int enable_count;
76 unsigned int prepare_count;
77 unsigned int protect_count;
78 unsigned long min_rate;
79 unsigned long max_rate;
80 unsigned long accuracy;
83 struct hlist_head children;
84 struct hlist_node child_node;
85 struct hlist_head clks;
86 unsigned int notifier_count;
87 #ifdef CONFIG_DEBUG_FS
88 struct dentry *dentry;
89 struct hlist_node debug_node;
94 #define CREATE_TRACE_POINTS
95 #include <trace/events/clk.h>
98 struct clk_core *core;
102 unsigned long min_rate;
103 unsigned long max_rate;
104 unsigned int exclusive_count;
105 struct hlist_node clks_node;
109 static int clk_pm_runtime_get(struct clk_core *core)
113 if (!core->rpm_enabled)
116 ret = pm_runtime_get_sync(core->dev);
118 pm_runtime_put_noidle(core->dev);
124 static void clk_pm_runtime_put(struct clk_core *core)
126 if (!core->rpm_enabled)
129 pm_runtime_put_sync(core->dev);
133 static void clk_prepare_lock(void)
135 if (!mutex_trylock(&prepare_lock)) {
136 if (prepare_owner == current) {
140 mutex_lock(&prepare_lock);
142 WARN_ON_ONCE(prepare_owner != NULL);
143 WARN_ON_ONCE(prepare_refcnt != 0);
144 prepare_owner = current;
148 static void clk_prepare_unlock(void)
150 WARN_ON_ONCE(prepare_owner != current);
151 WARN_ON_ONCE(prepare_refcnt == 0);
153 if (--prepare_refcnt)
155 prepare_owner = NULL;
156 mutex_unlock(&prepare_lock);
159 static unsigned long clk_enable_lock(void)
160 __acquires(enable_lock)
165 * On UP systems, spin_trylock_irqsave() always returns true, even if
166 * we already hold the lock. So, in that case, we rely only on
167 * reference counting.
169 if (!IS_ENABLED(CONFIG_SMP) ||
170 !spin_trylock_irqsave(&enable_lock, flags)) {
171 if (enable_owner == current) {
173 __acquire(enable_lock);
174 if (!IS_ENABLED(CONFIG_SMP))
175 local_save_flags(flags);
178 spin_lock_irqsave(&enable_lock, flags);
180 WARN_ON_ONCE(enable_owner != NULL);
181 WARN_ON_ONCE(enable_refcnt != 0);
182 enable_owner = current;
187 static void clk_enable_unlock(unsigned long flags)
188 __releases(enable_lock)
190 WARN_ON_ONCE(enable_owner != current);
191 WARN_ON_ONCE(enable_refcnt == 0);
193 if (--enable_refcnt) {
194 __release(enable_lock);
198 spin_unlock_irqrestore(&enable_lock, flags);
201 static bool clk_core_rate_is_protected(struct clk_core *core)
203 return core->protect_count;
206 static bool clk_core_is_prepared(struct clk_core *core)
211 * .is_prepared is optional for clocks that can prepare
212 * fall back to software usage counter if it is missing
214 if (!core->ops->is_prepared)
215 return core->prepare_count;
217 if (!clk_pm_runtime_get(core)) {
218 ret = core->ops->is_prepared(core->hw);
219 clk_pm_runtime_put(core);
225 static bool clk_core_is_enabled(struct clk_core *core)
230 * .is_enabled is only mandatory for clocks that gate
231 * fall back to software usage counter if .is_enabled is missing
233 if (!core->ops->is_enabled)
234 return core->enable_count;
237 * Check if clock controller's device is runtime active before
238 * calling .is_enabled callback. If not, assume that clock is
239 * disabled, because we might be called from atomic context, from
240 * which pm_runtime_get() is not allowed.
241 * This function is called mainly from clk_disable_unused_subtree,
242 * which ensures proper runtime pm activation of controller before
243 * taking enable spinlock, but the below check is needed if one tries
244 * to call it from other places.
246 if (core->rpm_enabled) {
247 pm_runtime_get_noresume(core->dev);
248 if (!pm_runtime_active(core->dev)) {
254 ret = core->ops->is_enabled(core->hw);
256 if (core->rpm_enabled)
257 pm_runtime_put(core->dev);
262 /*** helper functions ***/
264 const char *__clk_get_name(const struct clk *clk)
266 return !clk ? NULL : clk->core->name;
268 EXPORT_SYMBOL_GPL(__clk_get_name);
270 const char *clk_hw_get_name(const struct clk_hw *hw)
272 return hw->core->name;
274 EXPORT_SYMBOL_GPL(clk_hw_get_name);
276 struct clk_hw *__clk_get_hw(struct clk *clk)
278 return !clk ? NULL : clk->core->hw;
280 EXPORT_SYMBOL_GPL(__clk_get_hw);
282 unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
284 return hw->core->num_parents;
286 EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
288 struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
290 return hw->core->parent ? hw->core->parent->hw : NULL;
292 EXPORT_SYMBOL_GPL(clk_hw_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);
338 static int of_parse_clkspec(const struct device_node *np, int index,
339 const char *name, struct of_phandle_args *out_args);
340 static struct clk_hw *
341 of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec);
343 static inline int of_parse_clkspec(const struct device_node *np, int index,
345 struct of_phandle_args *out_args)
349 static inline struct clk_hw *
350 of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
352 return ERR_PTR(-ENOENT);
357 * clk_core_get - Find the clk_core parent of a clk
358 * @core: clk to find parent of
359 * @p_index: parent index to search for
361 * This is the preferred method for clk providers to find the parent of a
362 * clk when that parent is external to the clk controller. The parent_names
363 * array is indexed and treated as a local name matching a string in the device
364 * node's 'clock-names' property or as the 'con_id' matching the device's
365 * dev_name() in a clk_lookup. This allows clk providers to use their own
366 * namespace instead of looking for a globally unique parent string.
368 * For example the following DT snippet would allow a clock registered by the
369 * clock-controller@c001 that has a clk_init_data::parent_data array
370 * with 'xtal' in the 'name' member to find the clock provided by the
371 * clock-controller@f00abcd without needing to get the globally unique name of
374 * parent: clock-controller@f00abcd {
375 * reg = <0xf00abcd 0xabcd>;
376 * #clock-cells = <0>;
379 * clock-controller@c001 {
380 * reg = <0xc001 0xf00d>;
381 * clocks = <&parent>;
382 * clock-names = "xtal";
383 * #clock-cells = <1>;
386 * Returns: -ENOENT when the provider can't be found or the clk doesn't
387 * exist in the provider or the name can't be found in the DT node or
388 * in a clkdev lookup. NULL when the provider knows about the clk but it
389 * isn't provided on this system.
390 * A valid clk_core pointer when the clk can be found in the provider.
392 static struct clk_core *clk_core_get(struct clk_core *core, u8 p_index)
394 const char *name = core->parents[p_index].fw_name;
395 int index = core->parents[p_index].index;
396 struct clk_hw *hw = ERR_PTR(-ENOENT);
397 struct device *dev = core->dev;
398 const char *dev_id = dev ? dev_name(dev) : NULL;
399 struct device_node *np = core->of_node;
400 struct of_phandle_args clkspec;
402 if (np && (name || index >= 0) &&
403 !of_parse_clkspec(np, index, name, &clkspec)) {
404 hw = of_clk_get_hw_from_clkspec(&clkspec);
405 of_node_put(clkspec.np);
408 * If the DT search above couldn't find the provider fallback to
409 * looking up via clkdev based clk_lookups.
411 hw = clk_find_hw(dev_id, name);
420 static void clk_core_fill_parent_index(struct clk_core *core, u8 index)
422 struct clk_parent_map *entry = &core->parents[index];
423 struct clk_core *parent = ERR_PTR(-ENOENT);
426 parent = entry->hw->core;
428 * We have a direct reference but it isn't registered yet?
429 * Orphan it and let clk_reparent() update the orphan status
430 * when the parent is registered.
433 parent = ERR_PTR(-EPROBE_DEFER);
435 parent = clk_core_get(core, index);
436 if (PTR_ERR(parent) == -ENOENT && entry->name)
437 parent = clk_core_lookup(entry->name);
440 /* Only cache it if it's not an error */
442 entry->core = parent;
445 static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
448 if (!core || index >= core->num_parents || !core->parents)
451 if (!core->parents[index].core)
452 clk_core_fill_parent_index(core, index);
454 return core->parents[index].core;
458 clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
460 struct clk_core *parent;
462 parent = clk_core_get_parent_by_index(hw->core, index);
464 return !parent ? NULL : parent->hw;
466 EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
468 unsigned int __clk_get_enable_count(struct clk *clk)
470 return !clk ? 0 : clk->core->enable_count;
473 static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
478 if (!core->num_parents || core->parent)
482 * Clk must have a parent because num_parents > 0 but the parent isn't
483 * known yet. Best to return 0 as the rate of this clk until we can
484 * properly recalc the rate based on the parent's rate.
489 unsigned long clk_hw_get_rate(const struct clk_hw *hw)
491 return clk_core_get_rate_nolock(hw->core);
493 EXPORT_SYMBOL_GPL(clk_hw_get_rate);
495 static unsigned long clk_core_get_accuracy_no_lock(struct clk_core *core)
500 return core->accuracy;
503 unsigned long __clk_get_flags(struct clk *clk)
505 return !clk ? 0 : clk->core->flags;
507 EXPORT_SYMBOL_GPL(__clk_get_flags);
509 unsigned long clk_hw_get_flags(const struct clk_hw *hw)
511 return hw->core->flags;
513 EXPORT_SYMBOL_GPL(clk_hw_get_flags);
515 bool clk_hw_is_prepared(const struct clk_hw *hw)
517 return clk_core_is_prepared(hw->core);
519 EXPORT_SYMBOL_GPL(clk_hw_is_prepared);
521 bool clk_hw_rate_is_protected(const struct clk_hw *hw)
523 return clk_core_rate_is_protected(hw->core);
525 EXPORT_SYMBOL_GPL(clk_hw_rate_is_protected);
527 bool clk_hw_is_enabled(const struct clk_hw *hw)
529 return clk_core_is_enabled(hw->core);
531 EXPORT_SYMBOL_GPL(clk_hw_is_enabled);
533 bool __clk_is_enabled(struct clk *clk)
538 return clk_core_is_enabled(clk->core);
540 EXPORT_SYMBOL_GPL(__clk_is_enabled);
542 static bool mux_is_better_rate(unsigned long rate, unsigned long now,
543 unsigned long best, unsigned long flags)
545 if (flags & CLK_MUX_ROUND_CLOSEST)
546 return abs(now - rate) < abs(best - rate);
548 return now <= rate && now > best;
551 int clk_mux_determine_rate_flags(struct clk_hw *hw,
552 struct clk_rate_request *req,
555 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
556 int i, num_parents, ret;
557 unsigned long best = 0;
558 struct clk_rate_request parent_req = *req;
560 /* if NO_REPARENT flag set, pass through to current parent */
561 if (core->flags & CLK_SET_RATE_NO_REPARENT) {
562 parent = core->parent;
563 if (core->flags & CLK_SET_RATE_PARENT) {
564 ret = __clk_determine_rate(parent ? parent->hw : NULL,
569 best = parent_req.rate;
571 best = clk_core_get_rate_nolock(parent);
573 best = clk_core_get_rate_nolock(core);
579 /* find the parent that can provide the fastest rate <= rate */
580 num_parents = core->num_parents;
581 for (i = 0; i < num_parents; i++) {
582 parent = clk_core_get_parent_by_index(core, i);
586 if (core->flags & CLK_SET_RATE_PARENT) {
588 ret = __clk_determine_rate(parent->hw, &parent_req);
592 parent_req.rate = clk_core_get_rate_nolock(parent);
595 if (mux_is_better_rate(req->rate, parent_req.rate,
597 best_parent = parent;
598 best = parent_req.rate;
607 req->best_parent_hw = best_parent->hw;
608 req->best_parent_rate = best;
613 EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);
615 struct clk *__clk_lookup(const char *name)
617 struct clk_core *core = clk_core_lookup(name);
619 return !core ? NULL : core->hw->clk;
622 static void clk_core_get_boundaries(struct clk_core *core,
623 unsigned long *min_rate,
624 unsigned long *max_rate)
626 struct clk *clk_user;
628 lockdep_assert_held(&prepare_lock);
630 *min_rate = core->min_rate;
631 *max_rate = core->max_rate;
633 hlist_for_each_entry(clk_user, &core->clks, clks_node)
634 *min_rate = max(*min_rate, clk_user->min_rate);
636 hlist_for_each_entry(clk_user, &core->clks, clks_node)
637 *max_rate = min(*max_rate, clk_user->max_rate);
640 void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
641 unsigned long max_rate)
643 hw->core->min_rate = min_rate;
644 hw->core->max_rate = max_rate;
646 EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
649 * __clk_mux_determine_rate - clk_ops::determine_rate implementation for a mux type clk
650 * @hw: mux type clk to determine rate on
651 * @req: rate request, also used to return preferred parent and frequencies
653 * Helper for finding best parent to provide a given frequency. This can be used
654 * directly as a determine_rate callback (e.g. for a mux), or from a more
655 * complex clock that may combine a mux with other operations.
657 * Returns: 0 on success, -EERROR value on error
659 int __clk_mux_determine_rate(struct clk_hw *hw,
660 struct clk_rate_request *req)
662 return clk_mux_determine_rate_flags(hw, req, 0);
664 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
666 int __clk_mux_determine_rate_closest(struct clk_hw *hw,
667 struct clk_rate_request *req)
669 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
671 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
675 static void clk_core_rate_unprotect(struct clk_core *core)
677 lockdep_assert_held(&prepare_lock);
682 if (WARN(core->protect_count == 0,
683 "%s already unprotected\n", core->name))
686 if (--core->protect_count > 0)
689 clk_core_rate_unprotect(core->parent);
692 static int clk_core_rate_nuke_protect(struct clk_core *core)
696 lockdep_assert_held(&prepare_lock);
701 if (core->protect_count == 0)
704 ret = core->protect_count;
705 core->protect_count = 1;
706 clk_core_rate_unprotect(core);
712 * clk_rate_exclusive_put - release exclusivity over clock rate control
713 * @clk: the clk over which the exclusivity is released
715 * clk_rate_exclusive_put() completes a critical section during which a clock
716 * consumer cannot tolerate any other consumer making any operation on the
717 * clock which could result in a rate change or rate glitch. Exclusive clocks
718 * cannot have their rate changed, either directly or indirectly due to changes
719 * further up the parent chain of clocks. As a result, clocks up parent chain
720 * also get under exclusive control of the calling consumer.
722 * If exlusivity is claimed more than once on clock, even by the same consumer,
723 * the rate effectively gets locked as exclusivity can't be preempted.
725 * Calls to clk_rate_exclusive_put() must be balanced with calls to
726 * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
729 void clk_rate_exclusive_put(struct clk *clk)
737 * if there is something wrong with this consumer protect count, stop
738 * here before messing with the provider
740 if (WARN_ON(clk->exclusive_count <= 0))
743 clk_core_rate_unprotect(clk->core);
744 clk->exclusive_count--;
746 clk_prepare_unlock();
748 EXPORT_SYMBOL_GPL(clk_rate_exclusive_put);
750 static void clk_core_rate_protect(struct clk_core *core)
752 lockdep_assert_held(&prepare_lock);
757 if (core->protect_count == 0)
758 clk_core_rate_protect(core->parent);
760 core->protect_count++;
763 static void clk_core_rate_restore_protect(struct clk_core *core, int count)
765 lockdep_assert_held(&prepare_lock);
773 clk_core_rate_protect(core);
774 core->protect_count = count;
778 * clk_rate_exclusive_get - get exclusivity over the clk rate control
779 * @clk: the clk over which the exclusity of rate control is requested
781 * clk_rate_exclusive_get() begins a critical section during which a clock
782 * consumer cannot tolerate any other consumer making any operation on the
783 * clock which could result in a rate change or rate glitch. Exclusive clocks
784 * cannot have their rate changed, either directly or indirectly due to changes
785 * further up the parent chain of clocks. As a result, clocks up parent chain
786 * also get under exclusive control of the calling consumer.
788 * If exlusivity is claimed more than once on clock, even by the same consumer,
789 * the rate effectively gets locked as exclusivity can't be preempted.
791 * Calls to clk_rate_exclusive_get() should be balanced with calls to
792 * clk_rate_exclusive_put(). Calls to this function may sleep.
793 * Returns 0 on success, -EERROR otherwise
795 int clk_rate_exclusive_get(struct clk *clk)
801 clk_core_rate_protect(clk->core);
802 clk->exclusive_count++;
803 clk_prepare_unlock();
807 EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
809 static void clk_core_unprepare(struct clk_core *core)
811 lockdep_assert_held(&prepare_lock);
816 if (WARN(core->prepare_count == 0,
817 "%s already unprepared\n", core->name))
820 if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL,
821 "Unpreparing critical %s\n", core->name))
824 if (core->flags & CLK_SET_RATE_GATE)
825 clk_core_rate_unprotect(core);
827 if (--core->prepare_count > 0)
830 WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);
832 trace_clk_unprepare(core);
834 if (core->ops->unprepare)
835 core->ops->unprepare(core->hw);
837 clk_pm_runtime_put(core);
839 trace_clk_unprepare_complete(core);
840 clk_core_unprepare(core->parent);
843 static void clk_core_unprepare_lock(struct clk_core *core)
846 clk_core_unprepare(core);
847 clk_prepare_unlock();
851 * clk_unprepare - undo preparation of a clock source
852 * @clk: the clk being unprepared
854 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
855 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
856 * if the operation may sleep. One example is a clk which is accessed over
857 * I2c. In the complex case a clk gate operation may require a fast and a slow
858 * part. It is this reason that clk_unprepare and clk_disable are not mutually
859 * exclusive. In fact clk_disable must be called before clk_unprepare.
861 void clk_unprepare(struct clk *clk)
863 if (IS_ERR_OR_NULL(clk))
866 clk_core_unprepare_lock(clk->core);
868 EXPORT_SYMBOL_GPL(clk_unprepare);
870 static int clk_core_prepare(struct clk_core *core)
874 lockdep_assert_held(&prepare_lock);
879 if (core->prepare_count == 0) {
880 ret = clk_pm_runtime_get(core);
884 ret = clk_core_prepare(core->parent);
888 trace_clk_prepare(core);
890 if (core->ops->prepare)
891 ret = core->ops->prepare(core->hw);
893 trace_clk_prepare_complete(core);
899 core->prepare_count++;
902 * CLK_SET_RATE_GATE is a special case of clock protection
903 * Instead of a consumer claiming exclusive rate control, it is
904 * actually the provider which prevents any consumer from making any
905 * operation which could result in a rate change or rate glitch while
906 * the clock is prepared.
908 if (core->flags & CLK_SET_RATE_GATE)
909 clk_core_rate_protect(core);
913 clk_core_unprepare(core->parent);
915 clk_pm_runtime_put(core);
919 static int clk_core_prepare_lock(struct clk_core *core)
924 ret = clk_core_prepare(core);
925 clk_prepare_unlock();
931 * clk_prepare - prepare a clock source
932 * @clk: the clk being prepared
934 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
935 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
936 * operation may sleep. One example is a clk which is accessed over I2c. In
937 * the complex case a clk ungate operation may require a fast and a slow part.
938 * It is this reason that clk_prepare and clk_enable are not mutually
939 * exclusive. In fact clk_prepare must be called before clk_enable.
940 * Returns 0 on success, -EERROR otherwise.
942 int clk_prepare(struct clk *clk)
947 return clk_core_prepare_lock(clk->core);
949 EXPORT_SYMBOL_GPL(clk_prepare);
951 static void clk_core_disable(struct clk_core *core)
953 lockdep_assert_held(&enable_lock);
958 if (WARN(core->enable_count == 0, "%s already disabled\n", core->name))
961 if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL,
962 "Disabling critical %s\n", core->name))
965 if (--core->enable_count > 0)
968 trace_clk_disable_rcuidle(core);
970 if (core->ops->disable)
971 core->ops->disable(core->hw);
973 trace_clk_disable_complete_rcuidle(core);
975 clk_core_disable(core->parent);
978 static void clk_core_disable_lock(struct clk_core *core)
982 flags = clk_enable_lock();
983 clk_core_disable(core);
984 clk_enable_unlock(flags);
988 * clk_disable - gate a clock
989 * @clk: the clk being gated
991 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
992 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
993 * clk if the operation is fast and will never sleep. One example is a
994 * SoC-internal clk which is controlled via simple register writes. In the
995 * complex case a clk gate operation may require a fast and a slow part. It is
996 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
997 * In fact clk_disable must be called before clk_unprepare.
999 void clk_disable(struct clk *clk)
1001 if (IS_ERR_OR_NULL(clk))
1004 clk_core_disable_lock(clk->core);
1006 EXPORT_SYMBOL_GPL(clk_disable);
1008 static int clk_core_enable(struct clk_core *core)
1012 lockdep_assert_held(&enable_lock);
1017 if (WARN(core->prepare_count == 0,
1018 "Enabling unprepared %s\n", core->name))
1021 if (core->enable_count == 0) {
1022 ret = clk_core_enable(core->parent);
1027 trace_clk_enable_rcuidle(core);
1029 if (core->ops->enable)
1030 ret = core->ops->enable(core->hw);
1032 trace_clk_enable_complete_rcuidle(core);
1035 clk_core_disable(core->parent);
1040 core->enable_count++;
1044 static int clk_core_enable_lock(struct clk_core *core)
1046 unsigned long flags;
1049 flags = clk_enable_lock();
1050 ret = clk_core_enable(core);
1051 clk_enable_unlock(flags);
1057 * clk_gate_restore_context - restore context for poweroff
1058 * @hw: the clk_hw pointer of clock whose state is to be restored
1060 * The clock gate restore context function enables or disables
1061 * the gate clocks based on the enable_count. This is done in cases
1062 * where the clock context is lost and based on the enable_count
1063 * the clock either needs to be enabled/disabled. This
1064 * helps restore the state of gate clocks.
1066 void clk_gate_restore_context(struct clk_hw *hw)
1068 struct clk_core *core = hw->core;
1070 if (core->enable_count)
1071 core->ops->enable(hw);
1073 core->ops->disable(hw);
1075 EXPORT_SYMBOL_GPL(clk_gate_restore_context);
1077 static int clk_core_save_context(struct clk_core *core)
1079 struct clk_core *child;
1082 hlist_for_each_entry(child, &core->children, child_node) {
1083 ret = clk_core_save_context(child);
1088 if (core->ops && core->ops->save_context)
1089 ret = core->ops->save_context(core->hw);
1094 static void clk_core_restore_context(struct clk_core *core)
1096 struct clk_core *child;
1098 if (core->ops && core->ops->restore_context)
1099 core->ops->restore_context(core->hw);
1101 hlist_for_each_entry(child, &core->children, child_node)
1102 clk_core_restore_context(child);
1106 * clk_save_context - save clock context for poweroff
1108 * Saves the context of the clock register for powerstates in which the
1109 * contents of the registers will be lost. Occurs deep within the suspend
1110 * code. Returns 0 on success.
1112 int clk_save_context(void)
1114 struct clk_core *clk;
1117 hlist_for_each_entry(clk, &clk_root_list, child_node) {
1118 ret = clk_core_save_context(clk);
1123 hlist_for_each_entry(clk, &clk_orphan_list, child_node) {
1124 ret = clk_core_save_context(clk);
1131 EXPORT_SYMBOL_GPL(clk_save_context);
1134 * clk_restore_context - restore clock context after poweroff
1136 * Restore the saved clock context upon resume.
1139 void clk_restore_context(void)
1141 struct clk_core *core;
1143 hlist_for_each_entry(core, &clk_root_list, child_node)
1144 clk_core_restore_context(core);
1146 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1147 clk_core_restore_context(core);
1149 EXPORT_SYMBOL_GPL(clk_restore_context);
1152 * clk_enable - ungate a clock
1153 * @clk: the clk being ungated
1155 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
1156 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
1157 * if the operation will never sleep. One example is a SoC-internal clk which
1158 * is controlled via simple register writes. In the complex case a clk ungate
1159 * operation may require a fast and a slow part. It is this reason that
1160 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
1161 * must be called before clk_enable. Returns 0 on success, -EERROR
1164 int clk_enable(struct clk *clk)
1169 return clk_core_enable_lock(clk->core);
1171 EXPORT_SYMBOL_GPL(clk_enable);
1173 static int clk_core_prepare_enable(struct clk_core *core)
1177 ret = clk_core_prepare_lock(core);
1181 ret = clk_core_enable_lock(core);
1183 clk_core_unprepare_lock(core);
1188 static void clk_core_disable_unprepare(struct clk_core *core)
1190 clk_core_disable_lock(core);
1191 clk_core_unprepare_lock(core);
1194 static void __init clk_unprepare_unused_subtree(struct clk_core *core)
1196 struct clk_core *child;
1198 lockdep_assert_held(&prepare_lock);
1200 hlist_for_each_entry(child, &core->children, child_node)
1201 clk_unprepare_unused_subtree(child);
1203 if (core->prepare_count)
1206 if (core->flags & CLK_IGNORE_UNUSED)
1209 if (clk_pm_runtime_get(core))
1212 if (clk_core_is_prepared(core)) {
1213 trace_clk_unprepare(core);
1214 if (core->ops->unprepare_unused)
1215 core->ops->unprepare_unused(core->hw);
1216 else if (core->ops->unprepare)
1217 core->ops->unprepare(core->hw);
1218 trace_clk_unprepare_complete(core);
1221 clk_pm_runtime_put(core);
1224 static void __init clk_disable_unused_subtree(struct clk_core *core)
1226 struct clk_core *child;
1227 unsigned long flags;
1229 lockdep_assert_held(&prepare_lock);
1231 hlist_for_each_entry(child, &core->children, child_node)
1232 clk_disable_unused_subtree(child);
1234 if (core->flags & CLK_OPS_PARENT_ENABLE)
1235 clk_core_prepare_enable(core->parent);
1237 if (clk_pm_runtime_get(core))
1240 flags = clk_enable_lock();
1242 if (core->enable_count)
1245 if (core->flags & CLK_IGNORE_UNUSED)
1249 * some gate clocks have special needs during the disable-unused
1250 * sequence. call .disable_unused if available, otherwise fall
1253 if (clk_core_is_enabled(core)) {
1254 trace_clk_disable(core);
1255 if (core->ops->disable_unused)
1256 core->ops->disable_unused(core->hw);
1257 else if (core->ops->disable)
1258 core->ops->disable(core->hw);
1259 trace_clk_disable_complete(core);
1263 clk_enable_unlock(flags);
1264 clk_pm_runtime_put(core);
1266 if (core->flags & CLK_OPS_PARENT_ENABLE)
1267 clk_core_disable_unprepare(core->parent);
1270 static bool clk_ignore_unused __initdata;
1271 static int __init clk_ignore_unused_setup(char *__unused)
1273 clk_ignore_unused = true;
1276 __setup("clk_ignore_unused", clk_ignore_unused_setup);
1278 static int __init clk_disable_unused(void)
1280 struct clk_core *core;
1282 if (clk_ignore_unused) {
1283 pr_warn("clk: Not disabling unused clocks\n");
1289 hlist_for_each_entry(core, &clk_root_list, child_node)
1290 clk_disable_unused_subtree(core);
1292 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1293 clk_disable_unused_subtree(core);
1295 hlist_for_each_entry(core, &clk_root_list, child_node)
1296 clk_unprepare_unused_subtree(core);
1298 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1299 clk_unprepare_unused_subtree(core);
1301 clk_prepare_unlock();
1305 late_initcall_sync(clk_disable_unused);
1307 static int clk_core_determine_round_nolock(struct clk_core *core,
1308 struct clk_rate_request *req)
1312 lockdep_assert_held(&prepare_lock);
1318 * At this point, core protection will be disabled if
1319 * - if the provider is not protected at all
1320 * - if the calling consumer is the only one which has exclusivity
1323 if (clk_core_rate_is_protected(core)) {
1324 req->rate = core->rate;
1325 } else if (core->ops->determine_rate) {
1326 return core->ops->determine_rate(core->hw, req);
1327 } else if (core->ops->round_rate) {
1328 rate = core->ops->round_rate(core->hw, req->rate,
1329 &req->best_parent_rate);
1341 static void clk_core_init_rate_req(struct clk_core * const core,
1342 struct clk_rate_request *req)
1344 struct clk_core *parent;
1346 if (WARN_ON(!core || !req))
1349 parent = core->parent;
1351 req->best_parent_hw = parent->hw;
1352 req->best_parent_rate = parent->rate;
1354 req->best_parent_hw = NULL;
1355 req->best_parent_rate = 0;
1359 static bool clk_core_can_round(struct clk_core * const core)
1361 return core->ops->determine_rate || core->ops->round_rate;
1364 static int clk_core_round_rate_nolock(struct clk_core *core,
1365 struct clk_rate_request *req)
1367 lockdep_assert_held(&prepare_lock);
1374 clk_core_init_rate_req(core, req);
1376 if (clk_core_can_round(core))
1377 return clk_core_determine_round_nolock(core, req);
1378 else if (core->flags & CLK_SET_RATE_PARENT)
1379 return clk_core_round_rate_nolock(core->parent, req);
1381 req->rate = core->rate;
1386 * __clk_determine_rate - get the closest rate actually supported by a clock
1387 * @hw: determine the rate of this clock
1388 * @req: target rate request
1390 * Useful for clk_ops such as .set_rate and .determine_rate.
1392 int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
1399 return clk_core_round_rate_nolock(hw->core, req);
1401 EXPORT_SYMBOL_GPL(__clk_determine_rate);
1403 unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
1406 struct clk_rate_request req;
1408 clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate);
1411 ret = clk_core_round_rate_nolock(hw->core, &req);
1417 EXPORT_SYMBOL_GPL(clk_hw_round_rate);
1420 * clk_round_rate - round the given rate for a clk
1421 * @clk: the clk for which we are rounding a rate
1422 * @rate: the rate which is to be rounded
1424 * Takes in a rate as input and rounds it to a rate that the clk can actually
1425 * use which is then returned. If clk doesn't support round_rate operation
1426 * then the parent rate is returned.
1428 long clk_round_rate(struct clk *clk, unsigned long rate)
1430 struct clk_rate_request req;
1438 if (clk->exclusive_count)
1439 clk_core_rate_unprotect(clk->core);
1441 clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
1444 ret = clk_core_round_rate_nolock(clk->core, &req);
1446 if (clk->exclusive_count)
1447 clk_core_rate_protect(clk->core);
1449 clk_prepare_unlock();
1456 EXPORT_SYMBOL_GPL(clk_round_rate);
1459 * __clk_notify - call clk notifier chain
1460 * @core: clk that is changing rate
1461 * @msg: clk notifier type (see include/linux/clk.h)
1462 * @old_rate: old clk rate
1463 * @new_rate: new clk rate
1465 * Triggers a notifier call chain on the clk rate-change notification
1466 * for 'clk'. Passes a pointer to the struct clk and the previous
1467 * and current rates to the notifier callback. Intended to be called by
1468 * internal clock code only. Returns NOTIFY_DONE from the last driver
1469 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1470 * a driver returns that.
1472 static int __clk_notify(struct clk_core *core, unsigned long msg,
1473 unsigned long old_rate, unsigned long new_rate)
1475 struct clk_notifier *cn;
1476 struct clk_notifier_data cnd;
1477 int ret = NOTIFY_DONE;
1479 cnd.old_rate = old_rate;
1480 cnd.new_rate = new_rate;
1482 list_for_each_entry(cn, &clk_notifier_list, node) {
1483 if (cn->clk->core == core) {
1485 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
1487 if (ret & NOTIFY_STOP_MASK)
1496 * __clk_recalc_accuracies
1497 * @core: first clk in the subtree
1499 * Walks the subtree of clks starting with clk and recalculates accuracies as
1500 * it goes. Note that if a clk does not implement the .recalc_accuracy
1501 * callback then it is assumed that the clock will take on the accuracy of its
1504 static void __clk_recalc_accuracies(struct clk_core *core)
1506 unsigned long parent_accuracy = 0;
1507 struct clk_core *child;
1509 lockdep_assert_held(&prepare_lock);
1512 parent_accuracy = core->parent->accuracy;
1514 if (core->ops->recalc_accuracy)
1515 core->accuracy = core->ops->recalc_accuracy(core->hw,
1518 core->accuracy = parent_accuracy;
1520 hlist_for_each_entry(child, &core->children, child_node)
1521 __clk_recalc_accuracies(child);
1524 static long clk_core_get_accuracy_recalc(struct clk_core *core)
1526 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
1527 __clk_recalc_accuracies(core);
1529 return clk_core_get_accuracy_no_lock(core);
1533 * clk_get_accuracy - return the accuracy of clk
1534 * @clk: the clk whose accuracy is being returned
1536 * Simply returns the cached accuracy of the clk, unless
1537 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1539 * If clk is NULL then returns 0.
1541 long clk_get_accuracy(struct clk *clk)
1549 accuracy = clk_core_get_accuracy_recalc(clk->core);
1550 clk_prepare_unlock();
1554 EXPORT_SYMBOL_GPL(clk_get_accuracy);
1556 static unsigned long clk_recalc(struct clk_core *core,
1557 unsigned long parent_rate)
1559 unsigned long rate = parent_rate;
1561 if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
1562 rate = core->ops->recalc_rate(core->hw, parent_rate);
1563 clk_pm_runtime_put(core);
1569 * __clk_recalc_rates
1570 * @core: first clk in the subtree
1571 * @msg: notification type (see include/linux/clk.h)
1573 * Walks the subtree of clks starting with clk and recalculates rates as it
1574 * goes. Note that if a clk does not implement the .recalc_rate callback then
1575 * it is assumed that the clock will take on the rate of its parent.
1577 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1580 static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
1582 unsigned long old_rate;
1583 unsigned long parent_rate = 0;
1584 struct clk_core *child;
1586 lockdep_assert_held(&prepare_lock);
1588 old_rate = core->rate;
1591 parent_rate = core->parent->rate;
1593 core->rate = clk_recalc(core, parent_rate);
1596 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1597 * & ABORT_RATE_CHANGE notifiers
1599 if (core->notifier_count && msg)
1600 __clk_notify(core, msg, old_rate, core->rate);
1602 hlist_for_each_entry(child, &core->children, child_node)
1603 __clk_recalc_rates(child, msg);
1606 static unsigned long clk_core_get_rate_recalc(struct clk_core *core)
1608 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1609 __clk_recalc_rates(core, 0);
1611 return clk_core_get_rate_nolock(core);
1615 * clk_get_rate - return the rate of clk
1616 * @clk: the clk whose rate is being returned
1618 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1619 * is set, which means a recalc_rate will be issued.
1620 * If clk is NULL then returns 0.
1622 unsigned long clk_get_rate(struct clk *clk)
1630 rate = clk_core_get_rate_recalc(clk->core);
1631 clk_prepare_unlock();
1635 EXPORT_SYMBOL_GPL(clk_get_rate);
1637 static int clk_fetch_parent_index(struct clk_core *core,
1638 struct clk_core *parent)
1645 for (i = 0; i < core->num_parents; i++) {
1646 /* Found it first try! */
1647 if (core->parents[i].core == parent)
1650 /* Something else is here, so keep looking */
1651 if (core->parents[i].core)
1654 /* Maybe core hasn't been cached but the hw is all we know? */
1655 if (core->parents[i].hw) {
1656 if (core->parents[i].hw == parent->hw)
1659 /* Didn't match, but we're expecting a clk_hw */
1663 /* Maybe it hasn't been cached (clk_set_parent() path) */
1664 if (parent == clk_core_get(core, i))
1667 /* Fallback to comparing globally unique names */
1668 if (core->parents[i].name &&
1669 !strcmp(parent->name, core->parents[i].name))
1673 if (i == core->num_parents)
1676 core->parents[i].core = parent;
1681 * clk_hw_get_parent_index - return the index of the parent clock
1682 * @hw: clk_hw associated with the clk being consumed
1684 * Fetches and returns the index of parent clock. Returns -EINVAL if the given
1685 * clock does not have a current parent.
1687 int clk_hw_get_parent_index(struct clk_hw *hw)
1689 struct clk_hw *parent = clk_hw_get_parent(hw);
1691 if (WARN_ON(parent == NULL))
1694 return clk_fetch_parent_index(hw->core, parent->core);
1696 EXPORT_SYMBOL_GPL(clk_hw_get_parent_index);
1699 * Update the orphan status of @core and all its children.
1701 static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
1703 struct clk_core *child;
1705 core->orphan = is_orphan;
1707 hlist_for_each_entry(child, &core->children, child_node)
1708 clk_core_update_orphan_status(child, is_orphan);
1711 static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1713 bool was_orphan = core->orphan;
1715 hlist_del(&core->child_node);
1718 bool becomes_orphan = new_parent->orphan;
1720 /* avoid duplicate POST_RATE_CHANGE notifications */
1721 if (new_parent->new_child == core)
1722 new_parent->new_child = NULL;
1724 hlist_add_head(&core->child_node, &new_parent->children);
1726 if (was_orphan != becomes_orphan)
1727 clk_core_update_orphan_status(core, becomes_orphan);
1729 hlist_add_head(&core->child_node, &clk_orphan_list);
1731 clk_core_update_orphan_status(core, true);
1734 core->parent = new_parent;
1737 static struct clk_core *__clk_set_parent_before(struct clk_core *core,
1738 struct clk_core *parent)
1740 unsigned long flags;
1741 struct clk_core *old_parent = core->parent;
1744 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
1746 * 2. Migrate prepare state between parents and prevent race with
1749 * If the clock is not prepared, then a race with
1750 * clk_enable/disable() is impossible since we already have the
1751 * prepare lock (future calls to clk_enable() need to be preceded by
1754 * If the clock is prepared, migrate the prepared state to the new
1755 * parent and also protect against a race with clk_enable() by
1756 * forcing the clock and the new parent on. This ensures that all
1757 * future calls to clk_enable() are practically NOPs with respect to
1758 * hardware and software states.
1760 * See also: Comment for clk_set_parent() below.
1763 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
1764 if (core->flags & CLK_OPS_PARENT_ENABLE) {
1765 clk_core_prepare_enable(old_parent);
1766 clk_core_prepare_enable(parent);
1769 /* migrate prepare count if > 0 */
1770 if (core->prepare_count) {
1771 clk_core_prepare_enable(parent);
1772 clk_core_enable_lock(core);
1775 /* update the clk tree topology */
1776 flags = clk_enable_lock();
1777 clk_reparent(core, parent);
1778 clk_enable_unlock(flags);
1783 static void __clk_set_parent_after(struct clk_core *core,
1784 struct clk_core *parent,
1785 struct clk_core *old_parent)
1788 * Finish the migration of prepare state and undo the changes done
1789 * for preventing a race with clk_enable().
1791 if (core->prepare_count) {
1792 clk_core_disable_lock(core);
1793 clk_core_disable_unprepare(old_parent);
1796 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
1797 if (core->flags & CLK_OPS_PARENT_ENABLE) {
1798 clk_core_disable_unprepare(parent);
1799 clk_core_disable_unprepare(old_parent);
1803 static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
1806 unsigned long flags;
1808 struct clk_core *old_parent;
1810 old_parent = __clk_set_parent_before(core, parent);
1812 trace_clk_set_parent(core, parent);
1814 /* change clock input source */
1815 if (parent && core->ops->set_parent)
1816 ret = core->ops->set_parent(core->hw, p_index);
1818 trace_clk_set_parent_complete(core, parent);
1821 flags = clk_enable_lock();
1822 clk_reparent(core, old_parent);
1823 clk_enable_unlock(flags);
1824 __clk_set_parent_after(core, old_parent, parent);
1829 __clk_set_parent_after(core, parent, old_parent);
1835 * __clk_speculate_rates
1836 * @core: first clk in the subtree
1837 * @parent_rate: the "future" rate of clk's parent
1839 * Walks the subtree of clks starting with clk, speculating rates as it
1840 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1842 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1843 * pre-rate change notifications and returns early if no clks in the
1844 * subtree have subscribed to the notifications. Note that if a clk does not
1845 * implement the .recalc_rate callback then it is assumed that the clock will
1846 * take on the rate of its parent.
1848 static int __clk_speculate_rates(struct clk_core *core,
1849 unsigned long parent_rate)
1851 struct clk_core *child;
1852 unsigned long new_rate;
1853 int ret = NOTIFY_DONE;
1855 lockdep_assert_held(&prepare_lock);
1857 new_rate = clk_recalc(core, parent_rate);
1859 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1860 if (core->notifier_count)
1861 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
1863 if (ret & NOTIFY_STOP_MASK) {
1864 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1865 __func__, core->name, ret);
1869 hlist_for_each_entry(child, &core->children, child_node) {
1870 ret = __clk_speculate_rates(child, new_rate);
1871 if (ret & NOTIFY_STOP_MASK)
1879 static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
1880 struct clk_core *new_parent, u8 p_index)
1882 struct clk_core *child;
1884 core->new_rate = new_rate;
1885 core->new_parent = new_parent;
1886 core->new_parent_index = p_index;
1887 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1888 core->new_child = NULL;
1889 if (new_parent && new_parent != core->parent)
1890 new_parent->new_child = core;
1892 hlist_for_each_entry(child, &core->children, child_node) {
1893 child->new_rate = clk_recalc(child, new_rate);
1894 clk_calc_subtree(child, child->new_rate, NULL, 0);
1899 * calculate the new rates returning the topmost clock that has to be
1902 static struct clk_core *clk_calc_new_rates(struct clk_core *core,
1905 struct clk_core *top = core;
1906 struct clk_core *old_parent, *parent;
1907 unsigned long best_parent_rate = 0;
1908 unsigned long new_rate;
1909 unsigned long min_rate;
1910 unsigned long max_rate;
1915 if (IS_ERR_OR_NULL(core))
1918 /* save parent rate, if it exists */
1919 parent = old_parent = core->parent;
1921 best_parent_rate = parent->rate;
1923 clk_core_get_boundaries(core, &min_rate, &max_rate);
1925 /* find the closest rate and parent clk/rate */
1926 if (clk_core_can_round(core)) {
1927 struct clk_rate_request req;
1930 req.min_rate = min_rate;
1931 req.max_rate = max_rate;
1933 clk_core_init_rate_req(core, &req);
1935 ret = clk_core_determine_round_nolock(core, &req);
1939 best_parent_rate = req.best_parent_rate;
1940 new_rate = req.rate;
1941 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
1943 if (new_rate < min_rate || new_rate > max_rate)
1945 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
1946 /* pass-through clock without adjustable parent */
1947 core->new_rate = core->rate;
1950 /* pass-through clock with adjustable parent */
1951 top = clk_calc_new_rates(parent, rate);
1952 new_rate = parent->new_rate;
1956 /* some clocks must be gated to change parent */
1957 if (parent != old_parent &&
1958 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1959 pr_debug("%s: %s not gated but wants to reparent\n",
1960 __func__, core->name);
1964 /* try finding the new parent index */
1965 if (parent && core->num_parents > 1) {
1966 p_index = clk_fetch_parent_index(core, parent);
1968 pr_debug("%s: clk %s can not be parent of clk %s\n",
1969 __func__, parent->name, core->name);
1974 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
1975 best_parent_rate != parent->rate)
1976 top = clk_calc_new_rates(parent, best_parent_rate);
1979 clk_calc_subtree(core, new_rate, parent, p_index);
1985 * Notify about rate changes in a subtree. Always walk down the whole tree
1986 * so that in case of an error we can walk down the whole tree again and
1989 static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
1990 unsigned long event)
1992 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
1993 int ret = NOTIFY_DONE;
1995 if (core->rate == core->new_rate)
1998 if (core->notifier_count) {
1999 ret = __clk_notify(core, event, core->rate, core->new_rate);
2000 if (ret & NOTIFY_STOP_MASK)
2004 hlist_for_each_entry(child, &core->children, child_node) {
2005 /* Skip children who will be reparented to another clock */
2006 if (child->new_parent && child->new_parent != core)
2008 tmp_clk = clk_propagate_rate_change(child, event);
2013 /* handle the new child who might not be in core->children yet */
2014 if (core->new_child) {
2015 tmp_clk = clk_propagate_rate_change(core->new_child, event);
2024 * walk down a subtree and set the new rates notifying the rate
2027 static void clk_change_rate(struct clk_core *core)
2029 struct clk_core *child;
2030 struct hlist_node *tmp;
2031 unsigned long old_rate;
2032 unsigned long best_parent_rate = 0;
2033 bool skip_set_rate = false;
2034 struct clk_core *old_parent;
2035 struct clk_core *parent = NULL;
2037 old_rate = core->rate;
2039 if (core->new_parent) {
2040 parent = core->new_parent;
2041 best_parent_rate = core->new_parent->rate;
2042 } else if (core->parent) {
2043 parent = core->parent;
2044 best_parent_rate = core->parent->rate;
2047 if (clk_pm_runtime_get(core))
2050 if (core->flags & CLK_SET_RATE_UNGATE) {
2051 unsigned long flags;
2053 clk_core_prepare(core);
2054 flags = clk_enable_lock();
2055 clk_core_enable(core);
2056 clk_enable_unlock(flags);
2059 if (core->new_parent && core->new_parent != core->parent) {
2060 old_parent = __clk_set_parent_before(core, core->new_parent);
2061 trace_clk_set_parent(core, core->new_parent);
2063 if (core->ops->set_rate_and_parent) {
2064 skip_set_rate = true;
2065 core->ops->set_rate_and_parent(core->hw, core->new_rate,
2067 core->new_parent_index);
2068 } else if (core->ops->set_parent) {
2069 core->ops->set_parent(core->hw, core->new_parent_index);
2072 trace_clk_set_parent_complete(core, core->new_parent);
2073 __clk_set_parent_after(core, core->new_parent, old_parent);
2076 if (core->flags & CLK_OPS_PARENT_ENABLE)
2077 clk_core_prepare_enable(parent);
2079 trace_clk_set_rate(core, core->new_rate);
2081 if (!skip_set_rate && core->ops->set_rate)
2082 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
2084 trace_clk_set_rate_complete(core, core->new_rate);
2086 core->rate = clk_recalc(core, best_parent_rate);
2088 if (core->flags & CLK_SET_RATE_UNGATE) {
2089 unsigned long flags;
2091 flags = clk_enable_lock();
2092 clk_core_disable(core);
2093 clk_enable_unlock(flags);
2094 clk_core_unprepare(core);
2097 if (core->flags & CLK_OPS_PARENT_ENABLE)
2098 clk_core_disable_unprepare(parent);
2100 if (core->notifier_count && old_rate != core->rate)
2101 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
2103 if (core->flags & CLK_RECALC_NEW_RATES)
2104 (void)clk_calc_new_rates(core, core->new_rate);
2107 * Use safe iteration, as change_rate can actually swap parents
2108 * for certain clock types.
2110 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
2111 /* Skip children who will be reparented to another clock */
2112 if (child->new_parent && child->new_parent != core)
2114 clk_change_rate(child);
2117 /* handle the new child who might not be in core->children yet */
2118 if (core->new_child)
2119 clk_change_rate(core->new_child);
2121 clk_pm_runtime_put(core);
2124 static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
2125 unsigned long req_rate)
2128 struct clk_rate_request req;
2130 lockdep_assert_held(&prepare_lock);
2135 /* simulate what the rate would be if it could be freely set */
2136 cnt = clk_core_rate_nuke_protect(core);
2140 clk_core_get_boundaries(core, &req.min_rate, &req.max_rate);
2141 req.rate = req_rate;
2143 ret = clk_core_round_rate_nolock(core, &req);
2145 /* restore the protection */
2146 clk_core_rate_restore_protect(core, cnt);
2148 return ret ? 0 : req.rate;
2151 static int clk_core_set_rate_nolock(struct clk_core *core,
2152 unsigned long req_rate)
2154 struct clk_core *top, *fail_clk;
2161 rate = clk_core_req_round_rate_nolock(core, req_rate);
2163 /* bail early if nothing to do */
2164 if (rate == clk_core_get_rate_nolock(core))
2167 /* fail on a direct rate set of a protected provider */
2168 if (clk_core_rate_is_protected(core))
2171 /* calculate new rates and get the topmost changed clock */
2172 top = clk_calc_new_rates(core, req_rate);
2176 ret = clk_pm_runtime_get(core);
2180 /* notify that we are about to change rates */
2181 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
2183 pr_debug("%s: failed to set %s rate\n", __func__,
2185 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
2190 /* change the rates */
2191 clk_change_rate(top);
2193 core->req_rate = req_rate;
2195 clk_pm_runtime_put(core);
2201 * clk_set_rate - specify a new rate for clk
2202 * @clk: the clk whose rate is being changed
2203 * @rate: the new rate for clk
2205 * In the simplest case clk_set_rate will only adjust the rate of clk.
2207 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
2208 * propagate up to clk's parent; whether or not this happens depends on the
2209 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
2210 * after calling .round_rate then upstream parent propagation is ignored. If
2211 * *parent_rate comes back with a new rate for clk's parent then we propagate
2212 * up to clk's parent and set its rate. Upward propagation will continue
2213 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
2214 * .round_rate stops requesting changes to clk's parent_rate.
2216 * Rate changes are accomplished via tree traversal that also recalculates the
2217 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
2219 * Returns 0 on success, -EERROR otherwise.
2221 int clk_set_rate(struct clk *clk, unsigned long rate)
2228 /* prevent racing with updates to the clock topology */
2231 if (clk->exclusive_count)
2232 clk_core_rate_unprotect(clk->core);
2234 ret = clk_core_set_rate_nolock(clk->core, rate);
2236 if (clk->exclusive_count)
2237 clk_core_rate_protect(clk->core);
2239 clk_prepare_unlock();
2243 EXPORT_SYMBOL_GPL(clk_set_rate);
2246 * clk_set_rate_exclusive - specify a new rate and get exclusive control
2247 * @clk: the clk whose rate is being changed
2248 * @rate: the new rate for clk
2250 * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
2251 * within a critical section
2253 * This can be used initially to ensure that at least 1 consumer is
2254 * satisfied when several consumers are competing for exclusivity over the
2255 * same clock provider.
2257 * The exclusivity is not applied if setting the rate failed.
2259 * Calls to clk_rate_exclusive_get() should be balanced with calls to
2260 * clk_rate_exclusive_put().
2262 * Returns 0 on success, -EERROR otherwise.
2264 int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
2271 /* prevent racing with updates to the clock topology */
2275 * The temporary protection removal is not here, on purpose
2276 * This function is meant to be used instead of clk_rate_protect,
2277 * so before the consumer code path protect the clock provider
2280 ret = clk_core_set_rate_nolock(clk->core, rate);
2282 clk_core_rate_protect(clk->core);
2283 clk->exclusive_count++;
2286 clk_prepare_unlock();
2290 EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
2293 * clk_set_rate_range - set a rate range for a clock source
2294 * @clk: clock source
2295 * @min: desired minimum clock rate in Hz, inclusive
2296 * @max: desired maximum clock rate in Hz, inclusive
2298 * Returns success (0) or negative errno.
2300 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
2303 unsigned long old_min, old_max, rate;
2309 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
2310 __func__, clk->core->name, clk->dev_id, clk->con_id,
2317 if (clk->exclusive_count)
2318 clk_core_rate_unprotect(clk->core);
2320 /* Save the current values in case we need to rollback the change */
2321 old_min = clk->min_rate;
2322 old_max = clk->max_rate;
2323 clk->min_rate = min;
2324 clk->max_rate = max;
2326 rate = clk_core_get_rate_nolock(clk->core);
2327 if (rate < min || rate > max) {
2330 * We are in bit of trouble here, current rate is outside the
2331 * the requested range. We are going try to request appropriate
2332 * range boundary but there is a catch. It may fail for the
2333 * usual reason (clock broken, clock protected, etc) but also
2335 * - round_rate() was not favorable and fell on the wrong
2336 * side of the boundary
2337 * - the determine_rate() callback does not really check for
2338 * this corner case when determining the rate
2346 ret = clk_core_set_rate_nolock(clk->core, rate);
2348 /* rollback the changes */
2349 clk->min_rate = old_min;
2350 clk->max_rate = old_max;
2354 if (clk->exclusive_count)
2355 clk_core_rate_protect(clk->core);
2357 clk_prepare_unlock();
2361 EXPORT_SYMBOL_GPL(clk_set_rate_range);
2364 * clk_set_min_rate - set a minimum clock rate for a clock source
2365 * @clk: clock source
2366 * @rate: desired minimum clock rate in Hz, inclusive
2368 * Returns success (0) or negative errno.
2370 int clk_set_min_rate(struct clk *clk, unsigned long rate)
2375 return clk_set_rate_range(clk, rate, clk->max_rate);
2377 EXPORT_SYMBOL_GPL(clk_set_min_rate);
2380 * clk_set_max_rate - set a maximum clock rate for a clock source
2381 * @clk: clock source
2382 * @rate: desired maximum clock rate in Hz, inclusive
2384 * Returns success (0) or negative errno.
2386 int clk_set_max_rate(struct clk *clk, unsigned long rate)
2391 return clk_set_rate_range(clk, clk->min_rate, rate);
2393 EXPORT_SYMBOL_GPL(clk_set_max_rate);
2396 * clk_get_parent - return the parent of a clk
2397 * @clk: the clk whose parent gets returned
2399 * Simply returns clk->parent. Returns NULL if clk is NULL.
2401 struct clk *clk_get_parent(struct clk *clk)
2409 /* TODO: Create a per-user clk and change callers to call clk_put */
2410 parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
2411 clk_prepare_unlock();
2415 EXPORT_SYMBOL_GPL(clk_get_parent);
2417 static struct clk_core *__clk_init_parent(struct clk_core *core)
2421 if (core->num_parents > 1 && core->ops->get_parent)
2422 index = core->ops->get_parent(core->hw);
2424 return clk_core_get_parent_by_index(core, index);
2427 static void clk_core_reparent(struct clk_core *core,
2428 struct clk_core *new_parent)
2430 clk_reparent(core, new_parent);
2431 __clk_recalc_accuracies(core);
2432 __clk_recalc_rates(core, POST_RATE_CHANGE);
2435 void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
2440 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
2444 * clk_has_parent - check if a clock is a possible parent for another
2445 * @clk: clock source
2446 * @parent: parent clock source
2448 * This function can be used in drivers that need to check that a clock can be
2449 * the parent of another without actually changing the parent.
2451 * Returns true if @parent is a possible parent for @clk, false otherwise.
2453 bool clk_has_parent(struct clk *clk, struct clk *parent)
2455 struct clk_core *core, *parent_core;
2458 /* NULL clocks should be nops, so return success if either is NULL. */
2459 if (!clk || !parent)
2463 parent_core = parent->core;
2465 /* Optimize for the case where the parent is already the parent. */
2466 if (core->parent == parent_core)
2469 for (i = 0; i < core->num_parents; i++)
2470 if (!strcmp(core->parents[i].name, parent_core->name))
2475 EXPORT_SYMBOL_GPL(clk_has_parent);
2477 static int clk_core_set_parent_nolock(struct clk_core *core,
2478 struct clk_core *parent)
2482 unsigned long p_rate = 0;
2484 lockdep_assert_held(&prepare_lock);
2489 if (core->parent == parent)
2492 /* verify ops for multi-parent clks */
2493 if (core->num_parents > 1 && !core->ops->set_parent)
2496 /* check that we are allowed to re-parent if the clock is in use */
2497 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
2500 if (clk_core_rate_is_protected(core))
2503 /* try finding the new parent index */
2505 p_index = clk_fetch_parent_index(core, parent);
2507 pr_debug("%s: clk %s can not be parent of clk %s\n",
2508 __func__, parent->name, core->name);
2511 p_rate = parent->rate;
2514 ret = clk_pm_runtime_get(core);
2518 /* propagate PRE_RATE_CHANGE notifications */
2519 ret = __clk_speculate_rates(core, p_rate);
2521 /* abort if a driver objects */
2522 if (ret & NOTIFY_STOP_MASK)
2525 /* do the re-parent */
2526 ret = __clk_set_parent(core, parent, p_index);
2528 /* propagate rate an accuracy recalculation accordingly */
2530 __clk_recalc_rates(core, ABORT_RATE_CHANGE);
2532 __clk_recalc_rates(core, POST_RATE_CHANGE);
2533 __clk_recalc_accuracies(core);
2537 clk_pm_runtime_put(core);
2542 int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *parent)
2544 return clk_core_set_parent_nolock(hw->core, parent->core);
2546 EXPORT_SYMBOL_GPL(clk_hw_set_parent);
2549 * clk_set_parent - switch the parent of a mux clk
2550 * @clk: the mux clk whose input we are switching
2551 * @parent: the new input to clk
2553 * Re-parent clk to use parent as its new input source. If clk is in
2554 * prepared state, the clk will get enabled for the duration of this call. If
2555 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2556 * that, the reparenting is glitchy in hardware, etc), use the
2557 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2559 * After successfully changing clk's parent clk_set_parent will update the
2560 * clk topology, sysfs topology and propagate rate recalculation via
2561 * __clk_recalc_rates.
2563 * Returns 0 on success, -EERROR otherwise.
2565 int clk_set_parent(struct clk *clk, struct clk *parent)
2574 if (clk->exclusive_count)
2575 clk_core_rate_unprotect(clk->core);
2577 ret = clk_core_set_parent_nolock(clk->core,
2578 parent ? parent->core : NULL);
2580 if (clk->exclusive_count)
2581 clk_core_rate_protect(clk->core);
2583 clk_prepare_unlock();
2587 EXPORT_SYMBOL_GPL(clk_set_parent);
2589 static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
2593 lockdep_assert_held(&prepare_lock);
2598 if (clk_core_rate_is_protected(core))
2601 trace_clk_set_phase(core, degrees);
2603 if (core->ops->set_phase) {
2604 ret = core->ops->set_phase(core->hw, degrees);
2606 core->phase = degrees;
2609 trace_clk_set_phase_complete(core, degrees);
2615 * clk_set_phase - adjust the phase shift of a clock signal
2616 * @clk: clock signal source
2617 * @degrees: number of degrees the signal is shifted
2619 * Shifts the phase of a clock signal by the specified
2620 * degrees. Returns 0 on success, -EERROR otherwise.
2622 * This function makes no distinction about the input or reference
2623 * signal that we adjust the clock signal phase against. For example
2624 * phase locked-loop clock signal generators we may shift phase with
2625 * respect to feedback clock signal input, but for other cases the
2626 * clock phase may be shifted with respect to some other, unspecified
2629 * Additionally the concept of phase shift does not propagate through
2630 * the clock tree hierarchy, which sets it apart from clock rates and
2631 * clock accuracy. A parent clock phase attribute does not have an
2632 * impact on the phase attribute of a child clock.
2634 int clk_set_phase(struct clk *clk, int degrees)
2641 /* sanity check degrees */
2648 if (clk->exclusive_count)
2649 clk_core_rate_unprotect(clk->core);
2651 ret = clk_core_set_phase_nolock(clk->core, degrees);
2653 if (clk->exclusive_count)
2654 clk_core_rate_protect(clk->core);
2656 clk_prepare_unlock();
2660 EXPORT_SYMBOL_GPL(clk_set_phase);
2662 static int clk_core_get_phase(struct clk_core *core)
2666 lockdep_assert_held(&prepare_lock);
2667 if (!core->ops->get_phase)
2670 /* Always try to update cached phase if possible */
2671 ret = core->ops->get_phase(core->hw);
2679 * clk_get_phase - return the phase shift of a clock signal
2680 * @clk: clock signal source
2682 * Returns the phase shift of a clock node in degrees, otherwise returns
2685 int clk_get_phase(struct clk *clk)
2693 ret = clk_core_get_phase(clk->core);
2694 clk_prepare_unlock();
2698 EXPORT_SYMBOL_GPL(clk_get_phase);
2700 static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
2702 /* Assume a default value of 50% */
2707 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);
2709 static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
2711 struct clk_duty *duty = &core->duty;
2714 if (!core->ops->get_duty_cycle)
2715 return clk_core_update_duty_cycle_parent_nolock(core);
2717 ret = core->ops->get_duty_cycle(core->hw, duty);
2721 /* Don't trust the clock provider too much */
2722 if (duty->den == 0 || duty->num > duty->den) {
2730 clk_core_reset_duty_cycle_nolock(core);
2734 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
2739 core->flags & CLK_DUTY_CYCLE_PARENT) {
2740 ret = clk_core_update_duty_cycle_nolock(core->parent);
2741 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
2743 clk_core_reset_duty_cycle_nolock(core);
2749 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
2750 struct clk_duty *duty);
2752 static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
2753 struct clk_duty *duty)
2757 lockdep_assert_held(&prepare_lock);
2759 if (clk_core_rate_is_protected(core))
2762 trace_clk_set_duty_cycle(core, duty);
2764 if (!core->ops->set_duty_cycle)
2765 return clk_core_set_duty_cycle_parent_nolock(core, duty);
2767 ret = core->ops->set_duty_cycle(core->hw, duty);
2769 memcpy(&core->duty, duty, sizeof(*duty));
2771 trace_clk_set_duty_cycle_complete(core, duty);
2776 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
2777 struct clk_duty *duty)
2782 core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
2783 ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
2784 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
2791 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
2792 * @clk: clock signal source
2793 * @num: numerator of the duty cycle ratio to be applied
2794 * @den: denominator of the duty cycle ratio to be applied
2796 * Apply the duty cycle ratio if the ratio is valid and the clock can
2797 * perform this operation
2799 * Returns (0) on success, a negative errno otherwise.
2801 int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
2804 struct clk_duty duty;
2809 /* sanity check the ratio */
2810 if (den == 0 || num > den)
2818 if (clk->exclusive_count)
2819 clk_core_rate_unprotect(clk->core);
2821 ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
2823 if (clk->exclusive_count)
2824 clk_core_rate_protect(clk->core);
2826 clk_prepare_unlock();
2830 EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
2832 static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
2835 struct clk_duty *duty = &core->duty;
2840 ret = clk_core_update_duty_cycle_nolock(core);
2842 ret = mult_frac(scale, duty->num, duty->den);
2844 clk_prepare_unlock();
2850 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
2851 * @clk: clock signal source
2852 * @scale: scaling factor to be applied to represent the ratio as an integer
2854 * Returns the duty cycle ratio of a clock node multiplied by the provided
2855 * scaling factor, or negative errno on error.
2857 int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
2862 return clk_core_get_scaled_duty_cycle(clk->core, scale);
2864 EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
2867 * clk_is_match - check if two clk's point to the same hardware clock
2868 * @p: clk compared against q
2869 * @q: clk compared against p
2871 * Returns true if the two struct clk pointers both point to the same hardware
2872 * clock node. Put differently, returns true if struct clk *p and struct clk *q
2873 * share the same struct clk_core object.
2875 * Returns false otherwise. Note that two NULL clks are treated as matching.
2877 bool clk_is_match(const struct clk *p, const struct clk *q)
2879 /* trivial case: identical struct clk's or both NULL */
2883 /* true if clk->core pointers match. Avoid dereferencing garbage */
2884 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
2885 if (p->core == q->core)
2890 EXPORT_SYMBOL_GPL(clk_is_match);
2892 /*** debugfs support ***/
2894 #ifdef CONFIG_DEBUG_FS
2895 #include <linux/debugfs.h>
2897 static struct dentry *rootdir;
2898 static int inited = 0;
2899 static DEFINE_MUTEX(clk_debug_lock);
2900 static HLIST_HEAD(clk_debug_list);
2902 static struct hlist_head *orphan_list[] = {
2907 static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
2912 seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu ",
2914 30 - level * 3, c->name,
2915 c->enable_count, c->prepare_count, c->protect_count,
2916 clk_core_get_rate_recalc(c),
2917 clk_core_get_accuracy_recalc(c));
2919 phase = clk_core_get_phase(c);
2921 seq_printf(s, "%5d", phase);
2923 seq_puts(s, "-----");
2925 seq_printf(s, " %6d\n", clk_core_get_scaled_duty_cycle(c, 100000));
2928 static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
2931 struct clk_core *child;
2933 clk_summary_show_one(s, c, level);
2935 hlist_for_each_entry(child, &c->children, child_node)
2936 clk_summary_show_subtree(s, child, level + 1);
2939 static int clk_summary_show(struct seq_file *s, void *data)
2942 struct hlist_head **lists = (struct hlist_head **)s->private;
2944 seq_puts(s, " enable prepare protect duty\n");
2945 seq_puts(s, " clock count count count rate accuracy phase cycle\n");
2946 seq_puts(s, "---------------------------------------------------------------------------------------------\n");
2950 for (; *lists; lists++)
2951 hlist_for_each_entry(c, *lists, child_node)
2952 clk_summary_show_subtree(s, c, 0);
2954 clk_prepare_unlock();
2958 DEFINE_SHOW_ATTRIBUTE(clk_summary);
2960 static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
2963 unsigned long min_rate, max_rate;
2965 clk_core_get_boundaries(c, &min_rate, &max_rate);
2967 /* This should be JSON format, i.e. elements separated with a comma */
2968 seq_printf(s, "\"%s\": { ", c->name);
2969 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
2970 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
2971 seq_printf(s, "\"protect_count\": %d,", c->protect_count);
2972 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate_recalc(c));
2973 seq_printf(s, "\"min_rate\": %lu,", min_rate);
2974 seq_printf(s, "\"max_rate\": %lu,", max_rate);
2975 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy_recalc(c));
2976 phase = clk_core_get_phase(c);
2978 seq_printf(s, "\"phase\": %d,", phase);
2979 seq_printf(s, "\"duty_cycle\": %u",
2980 clk_core_get_scaled_duty_cycle(c, 100000));
2983 static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
2985 struct clk_core *child;
2987 clk_dump_one(s, c, level);
2989 hlist_for_each_entry(child, &c->children, child_node) {
2991 clk_dump_subtree(s, child, level + 1);
2997 static int clk_dump_show(struct seq_file *s, void *data)
3000 bool first_node = true;
3001 struct hlist_head **lists = (struct hlist_head **)s->private;
3006 for (; *lists; lists++) {
3007 hlist_for_each_entry(c, *lists, child_node) {
3011 clk_dump_subtree(s, c, 0);
3015 clk_prepare_unlock();
3020 DEFINE_SHOW_ATTRIBUTE(clk_dump);
3022 #undef CLOCK_ALLOW_WRITE_DEBUGFS
3023 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3025 * This can be dangerous, therefore don't provide any real compile time
3026 * configuration option for this feature.
3027 * People who want to use this will need to modify the source code directly.
3029 static int clk_rate_set(void *data, u64 val)
3031 struct clk_core *core = data;
3035 ret = clk_core_set_rate_nolock(core, val);
3036 clk_prepare_unlock();
3041 #define clk_rate_mode 0644
3043 #define clk_rate_set NULL
3044 #define clk_rate_mode 0444
3047 static int clk_rate_get(void *data, u64 *val)
3049 struct clk_core *core = data;
3055 DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops, clk_rate_get, clk_rate_set, "%llu\n");
3057 static const struct {
3061 #define ENTRY(f) { f, #f }
3062 ENTRY(CLK_SET_RATE_GATE),
3063 ENTRY(CLK_SET_PARENT_GATE),
3064 ENTRY(CLK_SET_RATE_PARENT),
3065 ENTRY(CLK_IGNORE_UNUSED),
3066 ENTRY(CLK_GET_RATE_NOCACHE),
3067 ENTRY(CLK_SET_RATE_NO_REPARENT),
3068 ENTRY(CLK_GET_ACCURACY_NOCACHE),
3069 ENTRY(CLK_RECALC_NEW_RATES),
3070 ENTRY(CLK_SET_RATE_UNGATE),
3071 ENTRY(CLK_IS_CRITICAL),
3072 ENTRY(CLK_OPS_PARENT_ENABLE),
3073 ENTRY(CLK_DUTY_CYCLE_PARENT),
3077 static int clk_flags_show(struct seq_file *s, void *data)
3079 struct clk_core *core = s->private;
3080 unsigned long flags = core->flags;
3083 for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
3084 if (flags & clk_flags[i].flag) {
3085 seq_printf(s, "%s\n", clk_flags[i].name);
3086 flags &= ~clk_flags[i].flag;
3091 seq_printf(s, "0x%lx\n", flags);
3096 DEFINE_SHOW_ATTRIBUTE(clk_flags);
3098 static void possible_parent_show(struct seq_file *s, struct clk_core *core,
3099 unsigned int i, char terminator)
3101 struct clk_core *parent;
3104 * Go through the following options to fetch a parent's name.
3106 * 1. Fetch the registered parent clock and use its name
3107 * 2. Use the global (fallback) name if specified
3108 * 3. Use the local fw_name if provided
3109 * 4. Fetch parent clock's clock-output-name if DT index was set
3111 * This may still fail in some cases, such as when the parent is
3112 * specified directly via a struct clk_hw pointer, but it isn't
3115 parent = clk_core_get_parent_by_index(core, i);
3117 seq_puts(s, parent->name);
3118 else if (core->parents[i].name)
3119 seq_puts(s, core->parents[i].name);
3120 else if (core->parents[i].fw_name)
3121 seq_printf(s, "<%s>(fw)", core->parents[i].fw_name);
3122 else if (core->parents[i].index >= 0)
3124 of_clk_get_parent_name(core->of_node,
3125 core->parents[i].index));
3127 seq_puts(s, "(missing)");
3129 seq_putc(s, terminator);
3132 static int possible_parents_show(struct seq_file *s, void *data)
3134 struct clk_core *core = s->private;
3137 for (i = 0; i < core->num_parents - 1; i++)
3138 possible_parent_show(s, core, i, ' ');
3140 possible_parent_show(s, core, i, '\n');
3144 DEFINE_SHOW_ATTRIBUTE(possible_parents);
3146 static int current_parent_show(struct seq_file *s, void *data)
3148 struct clk_core *core = s->private;
3151 seq_printf(s, "%s\n", core->parent->name);
3155 DEFINE_SHOW_ATTRIBUTE(current_parent);
3157 static int clk_duty_cycle_show(struct seq_file *s, void *data)
3159 struct clk_core *core = s->private;
3160 struct clk_duty *duty = &core->duty;
3162 seq_printf(s, "%u/%u\n", duty->num, duty->den);
3166 DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
3168 static int clk_min_rate_show(struct seq_file *s, void *data)
3170 struct clk_core *core = s->private;
3171 unsigned long min_rate, max_rate;
3174 clk_core_get_boundaries(core, &min_rate, &max_rate);
3175 clk_prepare_unlock();
3176 seq_printf(s, "%lu\n", min_rate);
3180 DEFINE_SHOW_ATTRIBUTE(clk_min_rate);
3182 static int clk_max_rate_show(struct seq_file *s, void *data)
3184 struct clk_core *core = s->private;
3185 unsigned long min_rate, max_rate;
3188 clk_core_get_boundaries(core, &min_rate, &max_rate);
3189 clk_prepare_unlock();
3190 seq_printf(s, "%lu\n", max_rate);
3194 DEFINE_SHOW_ATTRIBUTE(clk_max_rate);
3196 static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
3198 struct dentry *root;
3200 if (!core || !pdentry)
3203 root = debugfs_create_dir(core->name, pdentry);
3204 core->dentry = root;
3206 debugfs_create_file("clk_rate", clk_rate_mode, root, core,
3208 debugfs_create_file("clk_min_rate", 0444, root, core, &clk_min_rate_fops);
3209 debugfs_create_file("clk_max_rate", 0444, root, core, &clk_max_rate_fops);
3210 debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
3211 debugfs_create_u32("clk_phase", 0444, root, &core->phase);
3212 debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
3213 debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
3214 debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
3215 debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
3216 debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
3217 debugfs_create_file("clk_duty_cycle", 0444, root, core,
3218 &clk_duty_cycle_fops);
3220 if (core->num_parents > 0)
3221 debugfs_create_file("clk_parent", 0444, root, core,
3222 ¤t_parent_fops);
3224 if (core->num_parents > 1)
3225 debugfs_create_file("clk_possible_parents", 0444, root, core,
3226 &possible_parents_fops);
3228 if (core->ops->debug_init)
3229 core->ops->debug_init(core->hw, core->dentry);
3233 * clk_debug_register - add a clk node to the debugfs clk directory
3234 * @core: the clk being added to the debugfs clk directory
3236 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
3237 * initialized. Otherwise it bails out early since the debugfs clk directory
3238 * will be created lazily by clk_debug_init as part of a late_initcall.
3240 static void clk_debug_register(struct clk_core *core)
3242 mutex_lock(&clk_debug_lock);
3243 hlist_add_head(&core->debug_node, &clk_debug_list);
3245 clk_debug_create_one(core, rootdir);
3246 mutex_unlock(&clk_debug_lock);
3250 * clk_debug_unregister - remove a clk node from the debugfs clk directory
3251 * @core: the clk being removed from the debugfs clk directory
3253 * Dynamically removes a clk and all its child nodes from the
3254 * debugfs clk directory if clk->dentry points to debugfs created by
3255 * clk_debug_register in __clk_core_init.
3257 static void clk_debug_unregister(struct clk_core *core)
3259 mutex_lock(&clk_debug_lock);
3260 hlist_del_init(&core->debug_node);
3261 debugfs_remove_recursive(core->dentry);
3262 core->dentry = NULL;
3263 mutex_unlock(&clk_debug_lock);
3267 * clk_debug_init - lazily populate the debugfs clk directory
3269 * clks are often initialized very early during boot before memory can be
3270 * dynamically allocated and well before debugfs is setup. This function
3271 * populates the debugfs clk directory once at boot-time when we know that
3272 * debugfs is setup. It should only be called once at boot-time, all other clks
3273 * added dynamically will be done so with clk_debug_register.
3275 static int __init clk_debug_init(void)
3277 struct clk_core *core;
3279 rootdir = debugfs_create_dir("clk", NULL);
3281 debugfs_create_file("clk_summary", 0444, rootdir, &all_lists,
3283 debugfs_create_file("clk_dump", 0444, rootdir, &all_lists,
3285 debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list,
3287 debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list,
3290 mutex_lock(&clk_debug_lock);
3291 hlist_for_each_entry(core, &clk_debug_list, debug_node)
3292 clk_debug_create_one(core, rootdir);
3295 mutex_unlock(&clk_debug_lock);
3299 late_initcall(clk_debug_init);
3301 static inline void clk_debug_register(struct clk_core *core) { }
3302 static inline void clk_debug_unregister(struct clk_core *core)
3307 static void clk_core_reparent_orphans_nolock(void)
3309 struct clk_core *orphan;
3310 struct hlist_node *tmp2;
3313 * walk the list of orphan clocks and reparent any that newly finds a
3316 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
3317 struct clk_core *parent = __clk_init_parent(orphan);
3320 * We need to use __clk_set_parent_before() and _after() to
3321 * to properly migrate any prepare/enable count of the orphan
3322 * clock. This is important for CLK_IS_CRITICAL clocks, which
3323 * are enabled during init but might not have a parent yet.
3326 /* update the clk tree topology */
3327 __clk_set_parent_before(orphan, parent);
3328 __clk_set_parent_after(orphan, parent, NULL);
3329 __clk_recalc_accuracies(orphan);
3330 __clk_recalc_rates(orphan, 0);
3336 * __clk_core_init - initialize the data structures in a struct clk_core
3337 * @core: clk_core being initialized
3339 * Initializes the lists in struct clk_core, queries the hardware for the
3340 * parent and rate and sets them both.
3342 static int __clk_core_init(struct clk_core *core)
3345 struct clk_core *parent;
3354 ret = clk_pm_runtime_get(core);
3358 /* check to see if a clock with this name is already registered */
3359 if (clk_core_lookup(core->name)) {
3360 pr_debug("%s: clk %s already initialized\n",
3361 __func__, core->name);
3366 /* check that clk_ops are sane. See Documentation/driver-api/clk.rst */
3367 if (core->ops->set_rate &&
3368 !((core->ops->round_rate || core->ops->determine_rate) &&
3369 core->ops->recalc_rate)) {
3370 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
3371 __func__, core->name);
3376 if (core->ops->set_parent && !core->ops->get_parent) {
3377 pr_err("%s: %s must implement .get_parent & .set_parent\n",
3378 __func__, core->name);
3383 if (core->num_parents > 1 && !core->ops->get_parent) {
3384 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
3385 __func__, core->name);
3390 if (core->ops->set_rate_and_parent &&
3391 !(core->ops->set_parent && core->ops->set_rate)) {
3392 pr_err("%s: %s must implement .set_parent & .set_rate\n",
3393 __func__, core->name);
3399 * optional platform-specific magic
3401 * The .init callback is not used by any of the basic clock types, but
3402 * exists for weird hardware that must perform initialization magic for
3403 * CCF to get an accurate view of clock for any other callbacks. It may
3404 * also be used needs to perform dynamic allocations. Such allocation
3405 * must be freed in the terminate() callback.
3406 * This callback shall not be used to initialize the parameters state,
3407 * such as rate, parent, etc ...
3409 * If it exist, this callback should called before any other callback of
3412 if (core->ops->init) {
3413 ret = core->ops->init(core->hw);
3418 parent = core->parent = __clk_init_parent(core);
3421 * Populate core->parent if parent has already been clk_core_init'd. If
3422 * parent has not yet been clk_core_init'd then place clk in the orphan
3423 * list. If clk doesn't have any parents then place it in the root
3426 * Every time a new clk is clk_init'd then we walk the list of orphan
3427 * clocks and re-parent any that are children of the clock currently
3431 hlist_add_head(&core->child_node, &parent->children);
3432 core->orphan = parent->orphan;
3433 } else if (!core->num_parents) {
3434 hlist_add_head(&core->child_node, &clk_root_list);
3435 core->orphan = false;
3437 hlist_add_head(&core->child_node, &clk_orphan_list);
3438 core->orphan = true;
3442 * Set clk's accuracy. The preferred method is to use
3443 * .recalc_accuracy. For simple clocks and lazy developers the default
3444 * fallback is to use the parent's accuracy. If a clock doesn't have a
3445 * parent (or is orphaned) then accuracy is set to zero (perfect
3448 if (core->ops->recalc_accuracy)
3449 core->accuracy = core->ops->recalc_accuracy(core->hw,
3450 clk_core_get_accuracy_no_lock(parent));
3452 core->accuracy = parent->accuracy;
3457 * Set clk's phase by clk_core_get_phase() caching the phase.
3458 * Since a phase is by definition relative to its parent, just
3459 * query the current clock phase, or just assume it's in phase.
3461 phase = clk_core_get_phase(core);
3464 pr_warn("%s: Failed to get phase for clk '%s'\n", __func__,
3470 * Set clk's duty cycle.
3472 clk_core_update_duty_cycle_nolock(core);
3475 * Set clk's rate. The preferred method is to use .recalc_rate. For
3476 * simple clocks and lazy developers the default fallback is to use the
3477 * parent's rate. If a clock doesn't have a parent (or is orphaned)
3478 * then rate is set to zero.
3480 if (core->ops->recalc_rate)
3481 rate = core->ops->recalc_rate(core->hw,
3482 clk_core_get_rate_nolock(parent));
3484 rate = parent->rate;
3487 core->rate = core->req_rate = rate;
3490 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
3491 * don't get accidentally disabled when walking the orphan tree and
3492 * reparenting clocks
3494 if (core->flags & CLK_IS_CRITICAL) {
3495 unsigned long flags;
3497 ret = clk_core_prepare(core);
3499 pr_warn("%s: critical clk '%s' failed to prepare\n",
3500 __func__, core->name);
3504 flags = clk_enable_lock();
3505 ret = clk_core_enable(core);
3506 clk_enable_unlock(flags);
3508 pr_warn("%s: critical clk '%s' failed to enable\n",
3509 __func__, core->name);
3510 clk_core_unprepare(core);
3515 clk_core_reparent_orphans_nolock();
3518 kref_init(&core->ref);
3520 clk_pm_runtime_put(core);
3523 hlist_del_init(&core->child_node);
3525 clk_prepare_unlock();
3528 clk_debug_register(core);
3534 * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core
3535 * @core: clk to add consumer to
3536 * @clk: consumer to link to a clk
3538 static void clk_core_link_consumer(struct clk_core *core, struct clk *clk)
3541 hlist_add_head(&clk->clks_node, &core->clks);
3542 clk_prepare_unlock();
3546 * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core
3547 * @clk: consumer to unlink
3549 static void clk_core_unlink_consumer(struct clk *clk)
3551 lockdep_assert_held(&prepare_lock);
3552 hlist_del(&clk->clks_node);
3556 * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core
3557 * @core: clk to allocate a consumer for
3558 * @dev_id: string describing device name
3559 * @con_id: connection ID string on device
3561 * Returns: clk consumer left unlinked from the consumer list
3563 static struct clk *alloc_clk(struct clk_core *core, const char *dev_id,
3568 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
3570 return ERR_PTR(-ENOMEM);
3573 clk->dev_id = dev_id;
3574 clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
3575 clk->max_rate = ULONG_MAX;
3581 * free_clk - Free a clk consumer
3582 * @clk: clk consumer to free
3584 * Note, this assumes the clk has been unlinked from the clk_core consumer
3587 static void free_clk(struct clk *clk)
3589 kfree_const(clk->con_id);
3594 * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given
3596 * @dev: clk consumer device
3597 * @hw: clk_hw associated with the clk being consumed
3598 * @dev_id: string describing device name
3599 * @con_id: connection ID string on device
3601 * This is the main function used to create a clk pointer for use by clk
3602 * consumers. It connects a consumer to the clk_core and clk_hw structures
3603 * used by the framework and clk provider respectively.
3605 struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
3606 const char *dev_id, const char *con_id)
3609 struct clk_core *core;
3611 /* This is to allow this function to be chained to others */
3612 if (IS_ERR_OR_NULL(hw))
3613 return ERR_CAST(hw);
3616 clk = alloc_clk(core, dev_id, con_id);
3621 if (!try_module_get(core->owner)) {
3623 return ERR_PTR(-ENOENT);
3626 kref_get(&core->ref);
3627 clk_core_link_consumer(core, clk);
3632 static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
3642 *dst_p = dst = kstrdup_const(src, GFP_KERNEL);
3649 static int clk_core_populate_parent_map(struct clk_core *core,
3650 const struct clk_init_data *init)
3652 u8 num_parents = init->num_parents;
3653 const char * const *parent_names = init->parent_names;
3654 const struct clk_hw **parent_hws = init->parent_hws;
3655 const struct clk_parent_data *parent_data = init->parent_data;
3657 struct clk_parent_map *parents, *parent;
3663 * Avoid unnecessary string look-ups of clk_core's possible parents by
3664 * having a cache of names/clk_hw pointers to clk_core pointers.
3666 parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
3667 core->parents = parents;
3671 /* Copy everything over because it might be __initdata */
3672 for (i = 0, parent = parents; i < num_parents; i++, parent++) {
3675 /* throw a WARN if any entries are NULL */
3676 WARN(!parent_names[i],
3677 "%s: invalid NULL in %s's .parent_names\n",
3678 __func__, core->name);
3679 ret = clk_cpy_name(&parent->name, parent_names[i],
3681 } else if (parent_data) {
3682 parent->hw = parent_data[i].hw;
3683 parent->index = parent_data[i].index;
3684 ret = clk_cpy_name(&parent->fw_name,
3685 parent_data[i].fw_name, false);
3687 ret = clk_cpy_name(&parent->name,
3688 parent_data[i].name,
3690 } else if (parent_hws) {
3691 parent->hw = parent_hws[i];
3694 WARN(1, "Must specify parents if num_parents > 0\n");
3699 kfree_const(parents[i].name);
3700 kfree_const(parents[i].fw_name);
3711 static void clk_core_free_parent_map(struct clk_core *core)
3713 int i = core->num_parents;
3715 if (!core->num_parents)
3719 kfree_const(core->parents[i].name);
3720 kfree_const(core->parents[i].fw_name);
3723 kfree(core->parents);
3727 __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
3730 struct clk_core *core;
3731 const struct clk_init_data *init = hw->init;
3734 * The init data is not supposed to be used outside of registration path.
3735 * Set it to NULL so that provider drivers can't use it either and so that
3736 * we catch use of hw->init early on in the core.
3740 core = kzalloc(sizeof(*core), GFP_KERNEL);
3746 core->name = kstrdup_const(init->name, GFP_KERNEL);
3752 if (WARN_ON(!init->ops)) {
3756 core->ops = init->ops;
3758 if (dev && pm_runtime_enabled(dev))
3759 core->rpm_enabled = true;
3762 if (dev && dev->driver)
3763 core->owner = dev->driver->owner;
3765 core->flags = init->flags;
3766 core->num_parents = init->num_parents;
3768 core->max_rate = ULONG_MAX;
3771 ret = clk_core_populate_parent_map(core, init);
3775 INIT_HLIST_HEAD(&core->clks);
3778 * Don't call clk_hw_create_clk() here because that would pin the
3779 * provider module to itself and prevent it from ever being removed.
3781 hw->clk = alloc_clk(core, NULL, NULL);
3782 if (IS_ERR(hw->clk)) {
3783 ret = PTR_ERR(hw->clk);
3784 goto fail_create_clk;
3787 clk_core_link_consumer(hw->core, hw->clk);
3789 ret = __clk_core_init(core);
3794 clk_core_unlink_consumer(hw->clk);
3795 clk_prepare_unlock();
3801 clk_core_free_parent_map(core);
3804 kfree_const(core->name);
3808 return ERR_PTR(ret);
3812 * dev_or_parent_of_node() - Get device node of @dev or @dev's parent
3813 * @dev: Device to get device node of
3815 * Return: device node pointer of @dev, or the device node pointer of
3816 * @dev->parent if dev doesn't have a device node, or NULL if neither
3817 * @dev or @dev->parent have a device node.
3819 static struct device_node *dev_or_parent_of_node(struct device *dev)
3821 struct device_node *np;
3826 np = dev_of_node(dev);
3828 np = dev_of_node(dev->parent);
3834 * clk_register - allocate a new clock, register it and return an opaque cookie
3835 * @dev: device that is registering this clock
3836 * @hw: link to hardware-specific clock data
3838 * clk_register is the *deprecated* interface for populating the clock tree with
3839 * new clock nodes. Use clk_hw_register() instead.
3841 * Returns: a pointer to the newly allocated struct clk which
3842 * cannot be dereferenced by driver code but may be used in conjunction with the
3843 * rest of the clock API. In the event of an error clk_register will return an
3844 * error code; drivers must test for an error code after calling clk_register.
3846 struct clk *clk_register(struct device *dev, struct clk_hw *hw)
3848 return __clk_register(dev, dev_or_parent_of_node(dev), hw);
3850 EXPORT_SYMBOL_GPL(clk_register);
3853 * clk_hw_register - register a clk_hw and return an error code
3854 * @dev: device that is registering this clock
3855 * @hw: link to hardware-specific clock data
3857 * clk_hw_register is the primary interface for populating the clock tree with
3858 * new clock nodes. It returns an integer equal to zero indicating success or
3859 * less than zero indicating failure. Drivers must test for an error code after
3860 * calling clk_hw_register().
3862 int clk_hw_register(struct device *dev, struct clk_hw *hw)
3864 return PTR_ERR_OR_ZERO(__clk_register(dev, dev_or_parent_of_node(dev),
3867 EXPORT_SYMBOL_GPL(clk_hw_register);
3870 * of_clk_hw_register - register a clk_hw and return an error code
3871 * @node: device_node of device that is registering this clock
3872 * @hw: link to hardware-specific clock data
3874 * of_clk_hw_register() is the primary interface for populating the clock tree
3875 * with new clock nodes when a struct device is not available, but a struct
3876 * device_node is. It returns an integer equal to zero indicating success or
3877 * less than zero indicating failure. Drivers must test for an error code after
3878 * calling of_clk_hw_register().
3880 int of_clk_hw_register(struct device_node *node, struct clk_hw *hw)
3882 return PTR_ERR_OR_ZERO(__clk_register(NULL, node, hw));
3884 EXPORT_SYMBOL_GPL(of_clk_hw_register);
3886 /* Free memory allocated for a clock. */
3887 static void __clk_release(struct kref *ref)
3889 struct clk_core *core = container_of(ref, struct clk_core, ref);
3891 lockdep_assert_held(&prepare_lock);
3893 clk_core_free_parent_map(core);
3894 kfree_const(core->name);
3899 * Empty clk_ops for unregistered clocks. These are used temporarily
3900 * after clk_unregister() was called on a clock and until last clock
3901 * consumer calls clk_put() and the struct clk object is freed.
3903 static int clk_nodrv_prepare_enable(struct clk_hw *hw)
3908 static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
3913 static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
3914 unsigned long parent_rate)
3919 static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
3924 static const struct clk_ops clk_nodrv_ops = {
3925 .enable = clk_nodrv_prepare_enable,
3926 .disable = clk_nodrv_disable_unprepare,
3927 .prepare = clk_nodrv_prepare_enable,
3928 .unprepare = clk_nodrv_disable_unprepare,
3929 .set_rate = clk_nodrv_set_rate,
3930 .set_parent = clk_nodrv_set_parent,
3933 static void clk_core_evict_parent_cache_subtree(struct clk_core *root,
3934 struct clk_core *target)
3937 struct clk_core *child;
3939 for (i = 0; i < root->num_parents; i++)
3940 if (root->parents[i].core == target)
3941 root->parents[i].core = NULL;
3943 hlist_for_each_entry(child, &root->children, child_node)
3944 clk_core_evict_parent_cache_subtree(child, target);
3947 /* Remove this clk from all parent caches */
3948 static void clk_core_evict_parent_cache(struct clk_core *core)
3950 struct hlist_head **lists;
3951 struct clk_core *root;
3953 lockdep_assert_held(&prepare_lock);
3955 for (lists = all_lists; *lists; lists++)
3956 hlist_for_each_entry(root, *lists, child_node)
3957 clk_core_evict_parent_cache_subtree(root, core);
3962 * clk_unregister - unregister a currently registered clock
3963 * @clk: clock to unregister
3965 void clk_unregister(struct clk *clk)
3967 unsigned long flags;
3968 const struct clk_ops *ops;
3970 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
3973 clk_debug_unregister(clk->core);
3977 ops = clk->core->ops;
3978 if (ops == &clk_nodrv_ops) {
3979 pr_err("%s: unregistered clock: %s\n", __func__,
3984 * Assign empty clock ops for consumers that might still hold
3985 * a reference to this clock.
3987 flags = clk_enable_lock();
3988 clk->core->ops = &clk_nodrv_ops;
3989 clk_enable_unlock(flags);
3992 ops->terminate(clk->core->hw);
3994 if (!hlist_empty(&clk->core->children)) {
3995 struct clk_core *child;
3996 struct hlist_node *t;
3998 /* Reparent all children to the orphan list. */
3999 hlist_for_each_entry_safe(child, t, &clk->core->children,
4001 clk_core_set_parent_nolock(child, NULL);
4004 clk_core_evict_parent_cache(clk->core);
4006 hlist_del_init(&clk->core->child_node);
4008 if (clk->core->prepare_count)
4009 pr_warn("%s: unregistering prepared clock: %s\n",
4010 __func__, clk->core->name);
4012 if (clk->core->protect_count)
4013 pr_warn("%s: unregistering protected clock: %s\n",
4014 __func__, clk->core->name);
4016 kref_put(&clk->core->ref, __clk_release);
4019 clk_prepare_unlock();
4021 EXPORT_SYMBOL_GPL(clk_unregister);
4024 * clk_hw_unregister - unregister a currently registered clk_hw
4025 * @hw: hardware-specific clock data to unregister
4027 void clk_hw_unregister(struct clk_hw *hw)
4029 clk_unregister(hw->clk);
4031 EXPORT_SYMBOL_GPL(clk_hw_unregister);
4033 static void devm_clk_release(struct device *dev, void *res)
4035 clk_unregister(*(struct clk **)res);
4038 static void devm_clk_hw_release(struct device *dev, void *res)
4040 clk_hw_unregister(*(struct clk_hw **)res);
4044 * devm_clk_register - resource managed clk_register()
4045 * @dev: device that is registering this clock
4046 * @hw: link to hardware-specific clock data
4048 * Managed clk_register(). This function is *deprecated*, use devm_clk_hw_register() instead.
4050 * Clocks returned from this function are automatically clk_unregister()ed on
4051 * driver detach. See clk_register() for more information.
4053 struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
4058 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
4060 return ERR_PTR(-ENOMEM);
4062 clk = clk_register(dev, hw);
4065 devres_add(dev, clkp);
4072 EXPORT_SYMBOL_GPL(devm_clk_register);
4075 * devm_clk_hw_register - resource managed clk_hw_register()
4076 * @dev: device that is registering this clock
4077 * @hw: link to hardware-specific clock data
4079 * Managed clk_hw_register(). Clocks registered by this function are
4080 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
4081 * for more information.
4083 int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
4085 struct clk_hw **hwp;
4088 hwp = devres_alloc(devm_clk_hw_release, sizeof(*hwp), GFP_KERNEL);
4092 ret = clk_hw_register(dev, hw);
4095 devres_add(dev, hwp);
4102 EXPORT_SYMBOL_GPL(devm_clk_hw_register);
4104 static int devm_clk_match(struct device *dev, void *res, void *data)
4106 struct clk *c = res;
4112 static int devm_clk_hw_match(struct device *dev, void *res, void *data)
4114 struct clk_hw *hw = res;
4122 * devm_clk_unregister - resource managed clk_unregister()
4123 * @clk: clock to unregister
4125 * Deallocate a clock allocated with devm_clk_register(). Normally
4126 * this function will not need to be called and the resource management
4127 * code will ensure that the resource is freed.
4129 void devm_clk_unregister(struct device *dev, struct clk *clk)
4131 WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
4133 EXPORT_SYMBOL_GPL(devm_clk_unregister);
4136 * devm_clk_hw_unregister - resource managed clk_hw_unregister()
4137 * @dev: device that is unregistering the hardware-specific clock data
4138 * @hw: link to hardware-specific clock data
4140 * Unregister a clk_hw registered with devm_clk_hw_register(). Normally
4141 * this function will not need to be called and the resource management
4142 * code will ensure that the resource is freed.
4144 void devm_clk_hw_unregister(struct device *dev, struct clk_hw *hw)
4146 WARN_ON(devres_release(dev, devm_clk_hw_release, devm_clk_hw_match,
4149 EXPORT_SYMBOL_GPL(devm_clk_hw_unregister);
4155 void __clk_put(struct clk *clk)
4157 struct module *owner;
4159 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4165 * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
4166 * given user should be balanced with calls to clk_rate_exclusive_put()
4167 * and by that same consumer
4169 if (WARN_ON(clk->exclusive_count)) {
4170 /* We voiced our concern, let's sanitize the situation */
4171 clk->core->protect_count -= (clk->exclusive_count - 1);
4172 clk_core_rate_unprotect(clk->core);
4173 clk->exclusive_count = 0;
4176 hlist_del(&clk->clks_node);
4177 if (clk->min_rate > clk->core->req_rate ||
4178 clk->max_rate < clk->core->req_rate)
4179 clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
4181 owner = clk->core->owner;
4182 kref_put(&clk->core->ref, __clk_release);
4184 clk_prepare_unlock();
4191 /*** clk rate change notifiers ***/
4194 * clk_notifier_register - add a clk rate change notifier
4195 * @clk: struct clk * to watch
4196 * @nb: struct notifier_block * with callback info
4198 * Request notification when clk's rate changes. This uses an SRCU
4199 * notifier because we want it to block and notifier unregistrations are
4200 * uncommon. The callbacks associated with the notifier must not
4201 * re-enter into the clk framework by calling any top-level clk APIs;
4202 * this will cause a nested prepare_lock mutex.
4204 * In all notification cases (pre, post and abort rate change) the original
4205 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
4206 * and the new frequency is passed via struct clk_notifier_data.new_rate.
4208 * clk_notifier_register() must be called from non-atomic context.
4209 * Returns -EINVAL if called with null arguments, -ENOMEM upon
4210 * allocation failure; otherwise, passes along the return value of
4211 * srcu_notifier_chain_register().
4213 int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
4215 struct clk_notifier *cn;
4223 /* search the list of notifiers for this clk */
4224 list_for_each_entry(cn, &clk_notifier_list, node)
4228 /* if clk wasn't in the notifier list, allocate new clk_notifier */
4229 if (cn->clk != clk) {
4230 cn = kzalloc(sizeof(*cn), GFP_KERNEL);
4235 srcu_init_notifier_head(&cn->notifier_head);
4237 list_add(&cn->node, &clk_notifier_list);
4240 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
4242 clk->core->notifier_count++;
4245 clk_prepare_unlock();
4249 EXPORT_SYMBOL_GPL(clk_notifier_register);
4252 * clk_notifier_unregister - remove a clk rate change notifier
4253 * @clk: struct clk *
4254 * @nb: struct notifier_block * with callback info
4256 * Request no further notification for changes to 'clk' and frees memory
4257 * allocated in clk_notifier_register.
4259 * Returns -EINVAL if called with null arguments; otherwise, passes
4260 * along the return value of srcu_notifier_chain_unregister().
4262 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
4264 struct clk_notifier *cn = NULL;
4272 list_for_each_entry(cn, &clk_notifier_list, node)
4276 if (cn->clk == clk) {
4277 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
4279 clk->core->notifier_count--;
4281 /* XXX the notifier code should handle this better */
4282 if (!cn->notifier_head.head) {
4283 srcu_cleanup_notifier_head(&cn->notifier_head);
4284 list_del(&cn->node);
4292 clk_prepare_unlock();
4296 EXPORT_SYMBOL_GPL(clk_notifier_unregister);
4299 static void clk_core_reparent_orphans(void)
4302 clk_core_reparent_orphans_nolock();
4303 clk_prepare_unlock();
4307 * struct of_clk_provider - Clock provider registration structure
4308 * @link: Entry in global list of clock providers
4309 * @node: Pointer to device tree node of clock provider
4310 * @get: Get clock callback. Returns NULL or a struct clk for the
4311 * given clock specifier
4312 * @data: context pointer to be passed into @get callback
4314 struct of_clk_provider {
4315 struct list_head link;
4317 struct device_node *node;
4318 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
4319 struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
4323 extern struct of_device_id __clk_of_table;
4324 static const struct of_device_id __clk_of_table_sentinel
4325 __used __section(__clk_of_table_end);
4327 static LIST_HEAD(of_clk_providers);
4328 static DEFINE_MUTEX(of_clk_mutex);
4330 struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
4335 EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
4337 struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
4341 EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
4343 struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
4345 struct clk_onecell_data *clk_data = data;
4346 unsigned int idx = clkspec->args[0];
4348 if (idx >= clk_data->clk_num) {
4349 pr_err("%s: invalid clock index %u\n", __func__, idx);
4350 return ERR_PTR(-EINVAL);
4353 return clk_data->clks[idx];
4355 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
4358 of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
4360 struct clk_hw_onecell_data *hw_data = data;
4361 unsigned int idx = clkspec->args[0];
4363 if (idx >= hw_data->num) {
4364 pr_err("%s: invalid index %u\n", __func__, idx);
4365 return ERR_PTR(-EINVAL);
4368 return hw_data->hws[idx];
4370 EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
4373 * of_clk_add_provider() - Register a clock provider for a node
4374 * @np: Device node pointer associated with clock provider
4375 * @clk_src_get: callback for decoding clock
4376 * @data: context pointer for @clk_src_get callback.
4378 * This function is *deprecated*. Use of_clk_add_hw_provider() instead.
4380 int of_clk_add_provider(struct device_node *np,
4381 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
4385 struct of_clk_provider *cp;
4388 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
4392 cp->node = of_node_get(np);
4394 cp->get = clk_src_get;
4396 mutex_lock(&of_clk_mutex);
4397 list_add(&cp->link, &of_clk_providers);
4398 mutex_unlock(&of_clk_mutex);
4399 pr_debug("Added clock from %pOF\n", np);
4401 clk_core_reparent_orphans();
4403 ret = of_clk_set_defaults(np, true);
4405 of_clk_del_provider(np);
4409 EXPORT_SYMBOL_GPL(of_clk_add_provider);
4412 * of_clk_add_hw_provider() - Register a clock provider for a node
4413 * @np: Device node pointer associated with clock provider
4414 * @get: callback for decoding clk_hw
4415 * @data: context pointer for @get callback.
4417 int of_clk_add_hw_provider(struct device_node *np,
4418 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
4422 struct of_clk_provider *cp;
4425 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
4429 cp->node = of_node_get(np);
4433 mutex_lock(&of_clk_mutex);
4434 list_add(&cp->link, &of_clk_providers);
4435 mutex_unlock(&of_clk_mutex);
4436 pr_debug("Added clk_hw provider from %pOF\n", np);
4438 clk_core_reparent_orphans();
4440 ret = of_clk_set_defaults(np, true);
4442 of_clk_del_provider(np);
4446 EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
4448 static void devm_of_clk_release_provider(struct device *dev, void *res)
4450 of_clk_del_provider(*(struct device_node **)res);
4454 * We allow a child device to use its parent device as the clock provider node
4455 * for cases like MFD sub-devices where the child device driver wants to use
4456 * devm_*() APIs but not list the device in DT as a sub-node.
4458 static struct device_node *get_clk_provider_node(struct device *dev)
4460 struct device_node *np, *parent_np;
4463 parent_np = dev->parent ? dev->parent->of_node : NULL;
4465 if (!of_find_property(np, "#clock-cells", NULL))
4466 if (of_find_property(parent_np, "#clock-cells", NULL))
4473 * devm_of_clk_add_hw_provider() - Managed clk provider node registration
4474 * @dev: Device acting as the clock provider (used for DT node and lifetime)
4475 * @get: callback for decoding clk_hw
4476 * @data: context pointer for @get callback
4478 * Registers clock provider for given device's node. If the device has no DT
4479 * node or if the device node lacks of clock provider information (#clock-cells)
4480 * then the parent device's node is scanned for this information. If parent node
4481 * has the #clock-cells then it is used in registration. Provider is
4482 * automatically released at device exit.
4484 * Return: 0 on success or an errno on failure.
4486 int devm_of_clk_add_hw_provider(struct device *dev,
4487 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
4491 struct device_node **ptr, *np;
4494 ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
4499 np = get_clk_provider_node(dev);
4500 ret = of_clk_add_hw_provider(np, get, data);
4503 devres_add(dev, ptr);
4510 EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);
4513 * of_clk_del_provider() - Remove a previously registered clock provider
4514 * @np: Device node pointer associated with clock provider
4516 void of_clk_del_provider(struct device_node *np)
4518 struct of_clk_provider *cp;
4520 mutex_lock(&of_clk_mutex);
4521 list_for_each_entry(cp, &of_clk_providers, link) {
4522 if (cp->node == np) {
4523 list_del(&cp->link);
4524 of_node_put(cp->node);
4529 mutex_unlock(&of_clk_mutex);
4531 EXPORT_SYMBOL_GPL(of_clk_del_provider);
4533 static int devm_clk_provider_match(struct device *dev, void *res, void *data)
4535 struct device_node **np = res;
4537 if (WARN_ON(!np || !*np))
4544 * devm_of_clk_del_provider() - Remove clock provider registered using devm
4545 * @dev: Device to whose lifetime the clock provider was bound
4547 void devm_of_clk_del_provider(struct device *dev)
4550 struct device_node *np = get_clk_provider_node(dev);
4552 ret = devres_release(dev, devm_of_clk_release_provider,
4553 devm_clk_provider_match, np);
4557 EXPORT_SYMBOL(devm_of_clk_del_provider);
4560 * of_parse_clkspec() - Parse a DT clock specifier for a given device node
4561 * @np: device node to parse clock specifier from
4562 * @index: index of phandle to parse clock out of. If index < 0, @name is used
4563 * @name: clock name to find and parse. If name is NULL, the index is used
4564 * @out_args: Result of parsing the clock specifier
4566 * Parses a device node's "clocks" and "clock-names" properties to find the
4567 * phandle and cells for the index or name that is desired. The resulting clock
4568 * specifier is placed into @out_args, or an errno is returned when there's a
4569 * parsing error. The @index argument is ignored if @name is non-NULL.
4573 * phandle1: clock-controller@1 {
4574 * #clock-cells = <2>;
4577 * phandle2: clock-controller@2 {
4578 * #clock-cells = <1>;
4581 * clock-consumer@3 {
4582 * clocks = <&phandle1 1 2 &phandle2 3>;
4583 * clock-names = "name1", "name2";
4586 * To get a device_node for `clock-controller@2' node you may call this
4587 * function a few different ways:
4589 * of_parse_clkspec(clock-consumer@3, -1, "name2", &args);
4590 * of_parse_clkspec(clock-consumer@3, 1, NULL, &args);
4591 * of_parse_clkspec(clock-consumer@3, 1, "name2", &args);
4593 * Return: 0 upon successfully parsing the clock specifier. Otherwise, -ENOENT
4594 * if @name is NULL or -EINVAL if @name is non-NULL and it can't be found in
4595 * the "clock-names" property of @np.
4597 static int of_parse_clkspec(const struct device_node *np, int index,
4598 const char *name, struct of_phandle_args *out_args)
4602 /* Walk up the tree of devices looking for a clock property that matches */
4605 * For named clocks, first look up the name in the
4606 * "clock-names" property. If it cannot be found, then index
4607 * will be an error code and of_parse_phandle_with_args() will
4611 index = of_property_match_string(np, "clock-names", name);
4612 ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells",
4616 if (name && index >= 0)
4620 * No matching clock found on this node. If the parent node
4621 * has a "clock-ranges" property, then we can try one of its
4625 if (np && !of_get_property(np, "clock-ranges", NULL))
4633 static struct clk_hw *
4634 __of_clk_get_hw_from_provider(struct of_clk_provider *provider,
4635 struct of_phandle_args *clkspec)
4639 if (provider->get_hw)
4640 return provider->get_hw(clkspec, provider->data);
4642 clk = provider->get(clkspec, provider->data);
4644 return ERR_CAST(clk);
4645 return __clk_get_hw(clk);
4648 static struct clk_hw *
4649 of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
4651 struct of_clk_provider *provider;
4652 struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER);
4655 return ERR_PTR(-EINVAL);
4657 mutex_lock(&of_clk_mutex);
4658 list_for_each_entry(provider, &of_clk_providers, link) {
4659 if (provider->node == clkspec->np) {
4660 hw = __of_clk_get_hw_from_provider(provider, clkspec);
4665 mutex_unlock(&of_clk_mutex);
4671 * of_clk_get_from_provider() - Lookup a clock from a clock provider
4672 * @clkspec: pointer to a clock specifier data structure
4674 * This function looks up a struct clk from the registered list of clock
4675 * providers, an input is a clock specifier data structure as returned
4676 * from the of_parse_phandle_with_args() function call.
4678 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
4680 struct clk_hw *hw = of_clk_get_hw_from_clkspec(clkspec);
4682 return clk_hw_create_clk(NULL, hw, NULL, __func__);
4684 EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
4686 struct clk_hw *of_clk_get_hw(struct device_node *np, int index,
4691 struct of_phandle_args clkspec;
4693 ret = of_parse_clkspec(np, index, con_id, &clkspec);
4695 return ERR_PTR(ret);
4697 hw = of_clk_get_hw_from_clkspec(&clkspec);
4698 of_node_put(clkspec.np);
4703 static struct clk *__of_clk_get(struct device_node *np,
4704 int index, const char *dev_id,
4707 struct clk_hw *hw = of_clk_get_hw(np, index, con_id);
4709 return clk_hw_create_clk(NULL, hw, dev_id, con_id);
4712 struct clk *of_clk_get(struct device_node *np, int index)
4714 return __of_clk_get(np, index, np->full_name, NULL);
4716 EXPORT_SYMBOL(of_clk_get);
4719 * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
4720 * @np: pointer to clock consumer node
4721 * @name: name of consumer's clock input, or NULL for the first clock reference
4723 * This function parses the clocks and clock-names properties,
4724 * and uses them to look up the struct clk from the registered list of clock
4727 struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
4730 return ERR_PTR(-ENOENT);
4732 return __of_clk_get(np, 0, np->full_name, name);
4734 EXPORT_SYMBOL(of_clk_get_by_name);
4737 * of_clk_get_parent_count() - Count the number of clocks a device node has
4738 * @np: device node to count
4740 * Returns: The number of clocks that are possible parents of this node
4742 unsigned int of_clk_get_parent_count(const struct device_node *np)
4746 count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
4752 EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
4754 const char *of_clk_get_parent_name(const struct device_node *np, int index)
4756 struct of_phandle_args clkspec;
4757 struct property *prop;
4758 const char *clk_name;
4765 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
4770 index = clkspec.args_count ? clkspec.args[0] : 0;
4773 /* if there is an indices property, use it to transfer the index
4774 * specified into an array offset for the clock-output-names property.
4776 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
4783 /* We went off the end of 'clock-indices' without finding it */
4787 if (of_property_read_string_index(clkspec.np, "clock-output-names",
4791 * Best effort to get the name if the clock has been
4792 * registered with the framework. If the clock isn't
4793 * registered, we return the node name as the name of
4794 * the clock as long as #clock-cells = 0.
4796 clk = of_clk_get_from_provider(&clkspec);
4798 if (clkspec.args_count == 0)
4799 clk_name = clkspec.np->name;
4803 clk_name = __clk_get_name(clk);
4809 of_node_put(clkspec.np);
4812 EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
4815 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
4817 * @np: Device node pointer associated with clock provider
4818 * @parents: pointer to char array that hold the parents' names
4819 * @size: size of the @parents array
4821 * Return: number of parents for the clock node.
4823 int of_clk_parent_fill(struct device_node *np, const char **parents,
4828 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
4833 EXPORT_SYMBOL_GPL(of_clk_parent_fill);
4835 struct clock_provider {
4836 void (*clk_init_cb)(struct device_node *);
4837 struct device_node *np;
4838 struct list_head node;
4842 * This function looks for a parent clock. If there is one, then it
4843 * checks that the provider for this parent clock was initialized, in
4844 * this case the parent clock will be ready.
4846 static int parent_ready(struct device_node *np)
4851 struct clk *clk = of_clk_get(np, i);
4853 /* this parent is ready we can check the next one */
4860 /* at least one parent is not ready, we exit now */
4861 if (PTR_ERR(clk) == -EPROBE_DEFER)
4865 * Here we make assumption that the device tree is
4866 * written correctly. So an error means that there is
4867 * no more parent. As we didn't exit yet, then the
4868 * previous parent are ready. If there is no clock
4869 * parent, no need to wait for them, then we can
4870 * consider their absence as being ready
4877 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
4878 * @np: Device node pointer associated with clock provider
4879 * @index: clock index
4880 * @flags: pointer to top-level framework flags
4882 * Detects if the clock-critical property exists and, if so, sets the
4883 * corresponding CLK_IS_CRITICAL flag.
4885 * Do not use this function. It exists only for legacy Device Tree
4886 * bindings, such as the one-clock-per-node style that are outdated.
4887 * Those bindings typically put all clock data into .dts and the Linux
4888 * driver has no clock data, thus making it impossible to set this flag
4889 * correctly from the driver. Only those drivers may call
4890 * of_clk_detect_critical from their setup functions.
4892 * Return: error code or zero on success
4894 int of_clk_detect_critical(struct device_node *np, int index,
4895 unsigned long *flags)
4897 struct property *prop;
4904 of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
4906 *flags |= CLK_IS_CRITICAL;
4912 * of_clk_init() - Scan and init clock providers from the DT
4913 * @matches: array of compatible values and init functions for providers.
4915 * This function scans the device tree for matching clock providers
4916 * and calls their initialization functions. It also does it by trying
4917 * to follow the dependencies.
4919 void __init of_clk_init(const struct of_device_id *matches)
4921 const struct of_device_id *match;
4922 struct device_node *np;
4923 struct clock_provider *clk_provider, *next;
4926 LIST_HEAD(clk_provider_list);
4929 matches = &__clk_of_table;
4931 /* First prepare the list of the clocks providers */
4932 for_each_matching_node_and_match(np, matches, &match) {
4933 struct clock_provider *parent;
4935 if (!of_device_is_available(np))
4938 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
4940 list_for_each_entry_safe(clk_provider, next,
4941 &clk_provider_list, node) {
4942 list_del(&clk_provider->node);
4943 of_node_put(clk_provider->np);
4944 kfree(clk_provider);
4950 parent->clk_init_cb = match->data;
4951 parent->np = of_node_get(np);
4952 list_add_tail(&parent->node, &clk_provider_list);
4955 while (!list_empty(&clk_provider_list)) {
4956 is_init_done = false;
4957 list_for_each_entry_safe(clk_provider, next,
4958 &clk_provider_list, node) {
4959 if (force || parent_ready(clk_provider->np)) {
4961 /* Don't populate platform devices */
4962 of_node_set_flag(clk_provider->np,
4965 clk_provider->clk_init_cb(clk_provider->np);
4966 of_clk_set_defaults(clk_provider->np, true);
4968 list_del(&clk_provider->node);
4969 of_node_put(clk_provider->np);
4970 kfree(clk_provider);
4971 is_init_done = true;
4976 * We didn't manage to initialize any of the
4977 * remaining providers during the last loop, so now we
4978 * initialize all the remaining ones unconditionally
4979 * in case the clock parent was not mandatory