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);
1404 * clk_hw_round_rate() - round the given rate for a hw clk
1405 * @hw: the hw clk for which we are rounding a rate
1406 * @rate: the rate which is to be rounded
1408 * Takes in a rate as input and rounds it to a rate that the clk can actually
1411 * Context: prepare_lock must be held.
1412 * For clk providers to call from within clk_ops such as .round_rate,
1415 * Return: returns rounded rate of hw clk if clk supports round_rate operation
1416 * else returns the parent rate.
1418 unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
1421 struct clk_rate_request req;
1423 clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate);
1426 ret = clk_core_round_rate_nolock(hw->core, &req);
1432 EXPORT_SYMBOL_GPL(clk_hw_round_rate);
1435 * clk_round_rate - round the given rate for a clk
1436 * @clk: the clk for which we are rounding a rate
1437 * @rate: the rate which is to be rounded
1439 * Takes in a rate as input and rounds it to a rate that the clk can actually
1440 * use which is then returned. If clk doesn't support round_rate operation
1441 * then the parent rate is returned.
1443 long clk_round_rate(struct clk *clk, unsigned long rate)
1445 struct clk_rate_request req;
1453 if (clk->exclusive_count)
1454 clk_core_rate_unprotect(clk->core);
1456 clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
1459 ret = clk_core_round_rate_nolock(clk->core, &req);
1461 if (clk->exclusive_count)
1462 clk_core_rate_protect(clk->core);
1464 clk_prepare_unlock();
1471 EXPORT_SYMBOL_GPL(clk_round_rate);
1474 * __clk_notify - call clk notifier chain
1475 * @core: clk that is changing rate
1476 * @msg: clk notifier type (see include/linux/clk.h)
1477 * @old_rate: old clk rate
1478 * @new_rate: new clk rate
1480 * Triggers a notifier call chain on the clk rate-change notification
1481 * for 'clk'. Passes a pointer to the struct clk and the previous
1482 * and current rates to the notifier callback. Intended to be called by
1483 * internal clock code only. Returns NOTIFY_DONE from the last driver
1484 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1485 * a driver returns that.
1487 static int __clk_notify(struct clk_core *core, unsigned long msg,
1488 unsigned long old_rate, unsigned long new_rate)
1490 struct clk_notifier *cn;
1491 struct clk_notifier_data cnd;
1492 int ret = NOTIFY_DONE;
1494 cnd.old_rate = old_rate;
1495 cnd.new_rate = new_rate;
1497 list_for_each_entry(cn, &clk_notifier_list, node) {
1498 if (cn->clk->core == core) {
1500 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
1502 if (ret & NOTIFY_STOP_MASK)
1511 * __clk_recalc_accuracies
1512 * @core: first clk in the subtree
1514 * Walks the subtree of clks starting with clk and recalculates accuracies as
1515 * it goes. Note that if a clk does not implement the .recalc_accuracy
1516 * callback then it is assumed that the clock will take on the accuracy of its
1519 static void __clk_recalc_accuracies(struct clk_core *core)
1521 unsigned long parent_accuracy = 0;
1522 struct clk_core *child;
1524 lockdep_assert_held(&prepare_lock);
1527 parent_accuracy = core->parent->accuracy;
1529 if (core->ops->recalc_accuracy)
1530 core->accuracy = core->ops->recalc_accuracy(core->hw,
1533 core->accuracy = parent_accuracy;
1535 hlist_for_each_entry(child, &core->children, child_node)
1536 __clk_recalc_accuracies(child);
1539 static long clk_core_get_accuracy_recalc(struct clk_core *core)
1541 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
1542 __clk_recalc_accuracies(core);
1544 return clk_core_get_accuracy_no_lock(core);
1548 * clk_get_accuracy - return the accuracy of clk
1549 * @clk: the clk whose accuracy is being returned
1551 * Simply returns the cached accuracy of the clk, unless
1552 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1554 * If clk is NULL then returns 0.
1556 long clk_get_accuracy(struct clk *clk)
1564 accuracy = clk_core_get_accuracy_recalc(clk->core);
1565 clk_prepare_unlock();
1569 EXPORT_SYMBOL_GPL(clk_get_accuracy);
1571 static unsigned long clk_recalc(struct clk_core *core,
1572 unsigned long parent_rate)
1574 unsigned long rate = parent_rate;
1576 if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
1577 rate = core->ops->recalc_rate(core->hw, parent_rate);
1578 clk_pm_runtime_put(core);
1584 * __clk_recalc_rates
1585 * @core: first clk in the subtree
1586 * @msg: notification type (see include/linux/clk.h)
1588 * Walks the subtree of clks starting with clk and recalculates rates as it
1589 * goes. Note that if a clk does not implement the .recalc_rate callback then
1590 * it is assumed that the clock will take on the rate of its parent.
1592 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1595 static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
1597 unsigned long old_rate;
1598 unsigned long parent_rate = 0;
1599 struct clk_core *child;
1601 lockdep_assert_held(&prepare_lock);
1603 old_rate = core->rate;
1606 parent_rate = core->parent->rate;
1608 core->rate = clk_recalc(core, parent_rate);
1611 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1612 * & ABORT_RATE_CHANGE notifiers
1614 if (core->notifier_count && msg)
1615 __clk_notify(core, msg, old_rate, core->rate);
1617 hlist_for_each_entry(child, &core->children, child_node)
1618 __clk_recalc_rates(child, msg);
1621 static unsigned long clk_core_get_rate_recalc(struct clk_core *core)
1623 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1624 __clk_recalc_rates(core, 0);
1626 return clk_core_get_rate_nolock(core);
1630 * clk_get_rate - return the rate of clk
1631 * @clk: the clk whose rate is being returned
1633 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1634 * is set, which means a recalc_rate will be issued.
1635 * If clk is NULL then returns 0.
1637 unsigned long clk_get_rate(struct clk *clk)
1645 rate = clk_core_get_rate_recalc(clk->core);
1646 clk_prepare_unlock();
1650 EXPORT_SYMBOL_GPL(clk_get_rate);
1652 static int clk_fetch_parent_index(struct clk_core *core,
1653 struct clk_core *parent)
1660 for (i = 0; i < core->num_parents; i++) {
1661 /* Found it first try! */
1662 if (core->parents[i].core == parent)
1665 /* Something else is here, so keep looking */
1666 if (core->parents[i].core)
1669 /* Maybe core hasn't been cached but the hw is all we know? */
1670 if (core->parents[i].hw) {
1671 if (core->parents[i].hw == parent->hw)
1674 /* Didn't match, but we're expecting a clk_hw */
1678 /* Maybe it hasn't been cached (clk_set_parent() path) */
1679 if (parent == clk_core_get(core, i))
1682 /* Fallback to comparing globally unique names */
1683 if (core->parents[i].name &&
1684 !strcmp(parent->name, core->parents[i].name))
1688 if (i == core->num_parents)
1691 core->parents[i].core = parent;
1696 * clk_hw_get_parent_index - return the index of the parent clock
1697 * @hw: clk_hw associated with the clk being consumed
1699 * Fetches and returns the index of parent clock. Returns -EINVAL if the given
1700 * clock does not have a current parent.
1702 int clk_hw_get_parent_index(struct clk_hw *hw)
1704 struct clk_hw *parent = clk_hw_get_parent(hw);
1706 if (WARN_ON(parent == NULL))
1709 return clk_fetch_parent_index(hw->core, parent->core);
1711 EXPORT_SYMBOL_GPL(clk_hw_get_parent_index);
1714 * Update the orphan status of @core and all its children.
1716 static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
1718 struct clk_core *child;
1720 core->orphan = is_orphan;
1722 hlist_for_each_entry(child, &core->children, child_node)
1723 clk_core_update_orphan_status(child, is_orphan);
1726 static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1728 bool was_orphan = core->orphan;
1730 hlist_del(&core->child_node);
1733 bool becomes_orphan = new_parent->orphan;
1735 /* avoid duplicate POST_RATE_CHANGE notifications */
1736 if (new_parent->new_child == core)
1737 new_parent->new_child = NULL;
1739 hlist_add_head(&core->child_node, &new_parent->children);
1741 if (was_orphan != becomes_orphan)
1742 clk_core_update_orphan_status(core, becomes_orphan);
1744 hlist_add_head(&core->child_node, &clk_orphan_list);
1746 clk_core_update_orphan_status(core, true);
1749 core->parent = new_parent;
1752 static struct clk_core *__clk_set_parent_before(struct clk_core *core,
1753 struct clk_core *parent)
1755 unsigned long flags;
1756 struct clk_core *old_parent = core->parent;
1759 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
1761 * 2. Migrate prepare state between parents and prevent race with
1764 * If the clock is not prepared, then a race with
1765 * clk_enable/disable() is impossible since we already have the
1766 * prepare lock (future calls to clk_enable() need to be preceded by
1769 * If the clock is prepared, migrate the prepared state to the new
1770 * parent and also protect against a race with clk_enable() by
1771 * forcing the clock and the new parent on. This ensures that all
1772 * future calls to clk_enable() are practically NOPs with respect to
1773 * hardware and software states.
1775 * See also: Comment for clk_set_parent() below.
1778 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
1779 if (core->flags & CLK_OPS_PARENT_ENABLE) {
1780 clk_core_prepare_enable(old_parent);
1781 clk_core_prepare_enable(parent);
1784 /* migrate prepare count if > 0 */
1785 if (core->prepare_count) {
1786 clk_core_prepare_enable(parent);
1787 clk_core_enable_lock(core);
1790 /* update the clk tree topology */
1791 flags = clk_enable_lock();
1792 clk_reparent(core, parent);
1793 clk_enable_unlock(flags);
1798 static void __clk_set_parent_after(struct clk_core *core,
1799 struct clk_core *parent,
1800 struct clk_core *old_parent)
1803 * Finish the migration of prepare state and undo the changes done
1804 * for preventing a race with clk_enable().
1806 if (core->prepare_count) {
1807 clk_core_disable_lock(core);
1808 clk_core_disable_unprepare(old_parent);
1811 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
1812 if (core->flags & CLK_OPS_PARENT_ENABLE) {
1813 clk_core_disable_unprepare(parent);
1814 clk_core_disable_unprepare(old_parent);
1818 static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
1821 unsigned long flags;
1823 struct clk_core *old_parent;
1825 old_parent = __clk_set_parent_before(core, parent);
1827 trace_clk_set_parent(core, parent);
1829 /* change clock input source */
1830 if (parent && core->ops->set_parent)
1831 ret = core->ops->set_parent(core->hw, p_index);
1833 trace_clk_set_parent_complete(core, parent);
1836 flags = clk_enable_lock();
1837 clk_reparent(core, old_parent);
1838 clk_enable_unlock(flags);
1839 __clk_set_parent_after(core, old_parent, parent);
1844 __clk_set_parent_after(core, parent, old_parent);
1850 * __clk_speculate_rates
1851 * @core: first clk in the subtree
1852 * @parent_rate: the "future" rate of clk's parent
1854 * Walks the subtree of clks starting with clk, speculating rates as it
1855 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1857 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1858 * pre-rate change notifications and returns early if no clks in the
1859 * subtree have subscribed to the notifications. Note that if a clk does not
1860 * implement the .recalc_rate callback then it is assumed that the clock will
1861 * take on the rate of its parent.
1863 static int __clk_speculate_rates(struct clk_core *core,
1864 unsigned long parent_rate)
1866 struct clk_core *child;
1867 unsigned long new_rate;
1868 int ret = NOTIFY_DONE;
1870 lockdep_assert_held(&prepare_lock);
1872 new_rate = clk_recalc(core, parent_rate);
1874 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1875 if (core->notifier_count)
1876 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
1878 if (ret & NOTIFY_STOP_MASK) {
1879 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1880 __func__, core->name, ret);
1884 hlist_for_each_entry(child, &core->children, child_node) {
1885 ret = __clk_speculate_rates(child, new_rate);
1886 if (ret & NOTIFY_STOP_MASK)
1894 static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
1895 struct clk_core *new_parent, u8 p_index)
1897 struct clk_core *child;
1899 core->new_rate = new_rate;
1900 core->new_parent = new_parent;
1901 core->new_parent_index = p_index;
1902 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1903 core->new_child = NULL;
1904 if (new_parent && new_parent != core->parent)
1905 new_parent->new_child = core;
1907 hlist_for_each_entry(child, &core->children, child_node) {
1908 child->new_rate = clk_recalc(child, new_rate);
1909 clk_calc_subtree(child, child->new_rate, NULL, 0);
1914 * calculate the new rates returning the topmost clock that has to be
1917 static struct clk_core *clk_calc_new_rates(struct clk_core *core,
1920 struct clk_core *top = core;
1921 struct clk_core *old_parent, *parent;
1922 unsigned long best_parent_rate = 0;
1923 unsigned long new_rate;
1924 unsigned long min_rate;
1925 unsigned long max_rate;
1930 if (IS_ERR_OR_NULL(core))
1933 /* save parent rate, if it exists */
1934 parent = old_parent = core->parent;
1936 best_parent_rate = parent->rate;
1938 clk_core_get_boundaries(core, &min_rate, &max_rate);
1940 /* find the closest rate and parent clk/rate */
1941 if (clk_core_can_round(core)) {
1942 struct clk_rate_request req;
1945 req.min_rate = min_rate;
1946 req.max_rate = max_rate;
1948 clk_core_init_rate_req(core, &req);
1950 ret = clk_core_determine_round_nolock(core, &req);
1954 best_parent_rate = req.best_parent_rate;
1955 new_rate = req.rate;
1956 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
1958 if (new_rate < min_rate || new_rate > max_rate)
1960 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
1961 /* pass-through clock without adjustable parent */
1962 core->new_rate = core->rate;
1965 /* pass-through clock with adjustable parent */
1966 top = clk_calc_new_rates(parent, rate);
1967 new_rate = parent->new_rate;
1971 /* some clocks must be gated to change parent */
1972 if (parent != old_parent &&
1973 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1974 pr_debug("%s: %s not gated but wants to reparent\n",
1975 __func__, core->name);
1979 /* try finding the new parent index */
1980 if (parent && core->num_parents > 1) {
1981 p_index = clk_fetch_parent_index(core, parent);
1983 pr_debug("%s: clk %s can not be parent of clk %s\n",
1984 __func__, parent->name, core->name);
1989 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
1990 best_parent_rate != parent->rate)
1991 top = clk_calc_new_rates(parent, best_parent_rate);
1994 clk_calc_subtree(core, new_rate, parent, p_index);
2000 * Notify about rate changes in a subtree. Always walk down the whole tree
2001 * so that in case of an error we can walk down the whole tree again and
2004 static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
2005 unsigned long event)
2007 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
2008 int ret = NOTIFY_DONE;
2010 if (core->rate == core->new_rate)
2013 if (core->notifier_count) {
2014 ret = __clk_notify(core, event, core->rate, core->new_rate);
2015 if (ret & NOTIFY_STOP_MASK)
2019 hlist_for_each_entry(child, &core->children, child_node) {
2020 /* Skip children who will be reparented to another clock */
2021 if (child->new_parent && child->new_parent != core)
2023 tmp_clk = clk_propagate_rate_change(child, event);
2028 /* handle the new child who might not be in core->children yet */
2029 if (core->new_child) {
2030 tmp_clk = clk_propagate_rate_change(core->new_child, event);
2039 * walk down a subtree and set the new rates notifying the rate
2042 static void clk_change_rate(struct clk_core *core)
2044 struct clk_core *child;
2045 struct hlist_node *tmp;
2046 unsigned long old_rate;
2047 unsigned long best_parent_rate = 0;
2048 bool skip_set_rate = false;
2049 struct clk_core *old_parent;
2050 struct clk_core *parent = NULL;
2052 old_rate = core->rate;
2054 if (core->new_parent) {
2055 parent = core->new_parent;
2056 best_parent_rate = core->new_parent->rate;
2057 } else if (core->parent) {
2058 parent = core->parent;
2059 best_parent_rate = core->parent->rate;
2062 if (clk_pm_runtime_get(core))
2065 if (core->flags & CLK_SET_RATE_UNGATE) {
2066 unsigned long flags;
2068 clk_core_prepare(core);
2069 flags = clk_enable_lock();
2070 clk_core_enable(core);
2071 clk_enable_unlock(flags);
2074 if (core->new_parent && core->new_parent != core->parent) {
2075 old_parent = __clk_set_parent_before(core, core->new_parent);
2076 trace_clk_set_parent(core, core->new_parent);
2078 if (core->ops->set_rate_and_parent) {
2079 skip_set_rate = true;
2080 core->ops->set_rate_and_parent(core->hw, core->new_rate,
2082 core->new_parent_index);
2083 } else if (core->ops->set_parent) {
2084 core->ops->set_parent(core->hw, core->new_parent_index);
2087 trace_clk_set_parent_complete(core, core->new_parent);
2088 __clk_set_parent_after(core, core->new_parent, old_parent);
2091 if (core->flags & CLK_OPS_PARENT_ENABLE)
2092 clk_core_prepare_enable(parent);
2094 trace_clk_set_rate(core, core->new_rate);
2096 if (!skip_set_rate && core->ops->set_rate)
2097 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
2099 trace_clk_set_rate_complete(core, core->new_rate);
2101 core->rate = clk_recalc(core, best_parent_rate);
2103 if (core->flags & CLK_SET_RATE_UNGATE) {
2104 unsigned long flags;
2106 flags = clk_enable_lock();
2107 clk_core_disable(core);
2108 clk_enable_unlock(flags);
2109 clk_core_unprepare(core);
2112 if (core->flags & CLK_OPS_PARENT_ENABLE)
2113 clk_core_disable_unprepare(parent);
2115 if (core->notifier_count && old_rate != core->rate)
2116 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
2118 if (core->flags & CLK_RECALC_NEW_RATES)
2119 (void)clk_calc_new_rates(core, core->new_rate);
2122 * Use safe iteration, as change_rate can actually swap parents
2123 * for certain clock types.
2125 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
2126 /* Skip children who will be reparented to another clock */
2127 if (child->new_parent && child->new_parent != core)
2129 clk_change_rate(child);
2132 /* handle the new child who might not be in core->children yet */
2133 if (core->new_child)
2134 clk_change_rate(core->new_child);
2136 clk_pm_runtime_put(core);
2139 static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
2140 unsigned long req_rate)
2143 struct clk_rate_request req;
2145 lockdep_assert_held(&prepare_lock);
2150 /* simulate what the rate would be if it could be freely set */
2151 cnt = clk_core_rate_nuke_protect(core);
2155 clk_core_get_boundaries(core, &req.min_rate, &req.max_rate);
2156 req.rate = req_rate;
2158 ret = clk_core_round_rate_nolock(core, &req);
2160 /* restore the protection */
2161 clk_core_rate_restore_protect(core, cnt);
2163 return ret ? 0 : req.rate;
2166 static int clk_core_set_rate_nolock(struct clk_core *core,
2167 unsigned long req_rate)
2169 struct clk_core *top, *fail_clk;
2176 rate = clk_core_req_round_rate_nolock(core, req_rate);
2178 /* bail early if nothing to do */
2179 if (rate == clk_core_get_rate_nolock(core))
2182 /* fail on a direct rate set of a protected provider */
2183 if (clk_core_rate_is_protected(core))
2186 /* calculate new rates and get the topmost changed clock */
2187 top = clk_calc_new_rates(core, req_rate);
2191 ret = clk_pm_runtime_get(core);
2195 /* notify that we are about to change rates */
2196 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
2198 pr_debug("%s: failed to set %s rate\n", __func__,
2200 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
2205 /* change the rates */
2206 clk_change_rate(top);
2208 core->req_rate = req_rate;
2210 clk_pm_runtime_put(core);
2216 * clk_set_rate - specify a new rate for clk
2217 * @clk: the clk whose rate is being changed
2218 * @rate: the new rate for clk
2220 * In the simplest case clk_set_rate will only adjust the rate of clk.
2222 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
2223 * propagate up to clk's parent; whether or not this happens depends on the
2224 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
2225 * after calling .round_rate then upstream parent propagation is ignored. If
2226 * *parent_rate comes back with a new rate for clk's parent then we propagate
2227 * up to clk's parent and set its rate. Upward propagation will continue
2228 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
2229 * .round_rate stops requesting changes to clk's parent_rate.
2231 * Rate changes are accomplished via tree traversal that also recalculates the
2232 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
2234 * Returns 0 on success, -EERROR otherwise.
2236 int clk_set_rate(struct clk *clk, unsigned long rate)
2243 /* prevent racing with updates to the clock topology */
2246 if (clk->exclusive_count)
2247 clk_core_rate_unprotect(clk->core);
2249 ret = clk_core_set_rate_nolock(clk->core, rate);
2251 if (clk->exclusive_count)
2252 clk_core_rate_protect(clk->core);
2254 clk_prepare_unlock();
2258 EXPORT_SYMBOL_GPL(clk_set_rate);
2261 * clk_set_rate_exclusive - specify a new rate and get exclusive control
2262 * @clk: the clk whose rate is being changed
2263 * @rate: the new rate for clk
2265 * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
2266 * within a critical section
2268 * This can be used initially to ensure that at least 1 consumer is
2269 * satisfied when several consumers are competing for exclusivity over the
2270 * same clock provider.
2272 * The exclusivity is not applied if setting the rate failed.
2274 * Calls to clk_rate_exclusive_get() should be balanced with calls to
2275 * clk_rate_exclusive_put().
2277 * Returns 0 on success, -EERROR otherwise.
2279 int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
2286 /* prevent racing with updates to the clock topology */
2290 * The temporary protection removal is not here, on purpose
2291 * This function is meant to be used instead of clk_rate_protect,
2292 * so before the consumer code path protect the clock provider
2295 ret = clk_core_set_rate_nolock(clk->core, rate);
2297 clk_core_rate_protect(clk->core);
2298 clk->exclusive_count++;
2301 clk_prepare_unlock();
2305 EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
2308 * clk_set_rate_range - set a rate range for a clock source
2309 * @clk: clock source
2310 * @min: desired minimum clock rate in Hz, inclusive
2311 * @max: desired maximum clock rate in Hz, inclusive
2313 * Returns success (0) or negative errno.
2315 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
2318 unsigned long old_min, old_max, rate;
2324 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
2325 __func__, clk->core->name, clk->dev_id, clk->con_id,
2332 if (clk->exclusive_count)
2333 clk_core_rate_unprotect(clk->core);
2335 /* Save the current values in case we need to rollback the change */
2336 old_min = clk->min_rate;
2337 old_max = clk->max_rate;
2338 clk->min_rate = min;
2339 clk->max_rate = max;
2341 rate = clk_core_get_rate_nolock(clk->core);
2342 if (rate < min || rate > max) {
2345 * We are in bit of trouble here, current rate is outside the
2346 * the requested range. We are going try to request appropriate
2347 * range boundary but there is a catch. It may fail for the
2348 * usual reason (clock broken, clock protected, etc) but also
2350 * - round_rate() was not favorable and fell on the wrong
2351 * side of the boundary
2352 * - the determine_rate() callback does not really check for
2353 * this corner case when determining the rate
2361 ret = clk_core_set_rate_nolock(clk->core, rate);
2363 /* rollback the changes */
2364 clk->min_rate = old_min;
2365 clk->max_rate = old_max;
2369 if (clk->exclusive_count)
2370 clk_core_rate_protect(clk->core);
2372 clk_prepare_unlock();
2376 EXPORT_SYMBOL_GPL(clk_set_rate_range);
2379 * clk_set_min_rate - set a minimum clock rate for a clock source
2380 * @clk: clock source
2381 * @rate: desired minimum clock rate in Hz, inclusive
2383 * Returns success (0) or negative errno.
2385 int clk_set_min_rate(struct clk *clk, unsigned long rate)
2390 return clk_set_rate_range(clk, rate, clk->max_rate);
2392 EXPORT_SYMBOL_GPL(clk_set_min_rate);
2395 * clk_set_max_rate - set a maximum clock rate for a clock source
2396 * @clk: clock source
2397 * @rate: desired maximum clock rate in Hz, inclusive
2399 * Returns success (0) or negative errno.
2401 int clk_set_max_rate(struct clk *clk, unsigned long rate)
2406 return clk_set_rate_range(clk, clk->min_rate, rate);
2408 EXPORT_SYMBOL_GPL(clk_set_max_rate);
2411 * clk_get_parent - return the parent of a clk
2412 * @clk: the clk whose parent gets returned
2414 * Simply returns clk->parent. Returns NULL if clk is NULL.
2416 struct clk *clk_get_parent(struct clk *clk)
2424 /* TODO: Create a per-user clk and change callers to call clk_put */
2425 parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
2426 clk_prepare_unlock();
2430 EXPORT_SYMBOL_GPL(clk_get_parent);
2432 static struct clk_core *__clk_init_parent(struct clk_core *core)
2436 if (core->num_parents > 1 && core->ops->get_parent)
2437 index = core->ops->get_parent(core->hw);
2439 return clk_core_get_parent_by_index(core, index);
2442 static void clk_core_reparent(struct clk_core *core,
2443 struct clk_core *new_parent)
2445 clk_reparent(core, new_parent);
2446 __clk_recalc_accuracies(core);
2447 __clk_recalc_rates(core, POST_RATE_CHANGE);
2450 void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
2455 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
2459 * clk_has_parent - check if a clock is a possible parent for another
2460 * @clk: clock source
2461 * @parent: parent clock source
2463 * This function can be used in drivers that need to check that a clock can be
2464 * the parent of another without actually changing the parent.
2466 * Returns true if @parent is a possible parent for @clk, false otherwise.
2468 bool clk_has_parent(struct clk *clk, struct clk *parent)
2470 struct clk_core *core, *parent_core;
2473 /* NULL clocks should be nops, so return success if either is NULL. */
2474 if (!clk || !parent)
2478 parent_core = parent->core;
2480 /* Optimize for the case where the parent is already the parent. */
2481 if (core->parent == parent_core)
2484 for (i = 0; i < core->num_parents; i++)
2485 if (!strcmp(core->parents[i].name, parent_core->name))
2490 EXPORT_SYMBOL_GPL(clk_has_parent);
2492 static int clk_core_set_parent_nolock(struct clk_core *core,
2493 struct clk_core *parent)
2497 unsigned long p_rate = 0;
2499 lockdep_assert_held(&prepare_lock);
2504 if (core->parent == parent)
2507 /* verify ops for multi-parent clks */
2508 if (core->num_parents > 1 && !core->ops->set_parent)
2511 /* check that we are allowed to re-parent if the clock is in use */
2512 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
2515 if (clk_core_rate_is_protected(core))
2518 /* try finding the new parent index */
2520 p_index = clk_fetch_parent_index(core, parent);
2522 pr_debug("%s: clk %s can not be parent of clk %s\n",
2523 __func__, parent->name, core->name);
2526 p_rate = parent->rate;
2529 ret = clk_pm_runtime_get(core);
2533 /* propagate PRE_RATE_CHANGE notifications */
2534 ret = __clk_speculate_rates(core, p_rate);
2536 /* abort if a driver objects */
2537 if (ret & NOTIFY_STOP_MASK)
2540 /* do the re-parent */
2541 ret = __clk_set_parent(core, parent, p_index);
2543 /* propagate rate an accuracy recalculation accordingly */
2545 __clk_recalc_rates(core, ABORT_RATE_CHANGE);
2547 __clk_recalc_rates(core, POST_RATE_CHANGE);
2548 __clk_recalc_accuracies(core);
2552 clk_pm_runtime_put(core);
2557 int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *parent)
2559 return clk_core_set_parent_nolock(hw->core, parent->core);
2561 EXPORT_SYMBOL_GPL(clk_hw_set_parent);
2564 * clk_set_parent - switch the parent of a mux clk
2565 * @clk: the mux clk whose input we are switching
2566 * @parent: the new input to clk
2568 * Re-parent clk to use parent as its new input source. If clk is in
2569 * prepared state, the clk will get enabled for the duration of this call. If
2570 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2571 * that, the reparenting is glitchy in hardware, etc), use the
2572 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2574 * After successfully changing clk's parent clk_set_parent will update the
2575 * clk topology, sysfs topology and propagate rate recalculation via
2576 * __clk_recalc_rates.
2578 * Returns 0 on success, -EERROR otherwise.
2580 int clk_set_parent(struct clk *clk, struct clk *parent)
2589 if (clk->exclusive_count)
2590 clk_core_rate_unprotect(clk->core);
2592 ret = clk_core_set_parent_nolock(clk->core,
2593 parent ? parent->core : NULL);
2595 if (clk->exclusive_count)
2596 clk_core_rate_protect(clk->core);
2598 clk_prepare_unlock();
2602 EXPORT_SYMBOL_GPL(clk_set_parent);
2604 static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
2608 lockdep_assert_held(&prepare_lock);
2613 if (clk_core_rate_is_protected(core))
2616 trace_clk_set_phase(core, degrees);
2618 if (core->ops->set_phase) {
2619 ret = core->ops->set_phase(core->hw, degrees);
2621 core->phase = degrees;
2624 trace_clk_set_phase_complete(core, degrees);
2630 * clk_set_phase - adjust the phase shift of a clock signal
2631 * @clk: clock signal source
2632 * @degrees: number of degrees the signal is shifted
2634 * Shifts the phase of a clock signal by the specified
2635 * degrees. Returns 0 on success, -EERROR otherwise.
2637 * This function makes no distinction about the input or reference
2638 * signal that we adjust the clock signal phase against. For example
2639 * phase locked-loop clock signal generators we may shift phase with
2640 * respect to feedback clock signal input, but for other cases the
2641 * clock phase may be shifted with respect to some other, unspecified
2644 * Additionally the concept of phase shift does not propagate through
2645 * the clock tree hierarchy, which sets it apart from clock rates and
2646 * clock accuracy. A parent clock phase attribute does not have an
2647 * impact on the phase attribute of a child clock.
2649 int clk_set_phase(struct clk *clk, int degrees)
2656 /* sanity check degrees */
2663 if (clk->exclusive_count)
2664 clk_core_rate_unprotect(clk->core);
2666 ret = clk_core_set_phase_nolock(clk->core, degrees);
2668 if (clk->exclusive_count)
2669 clk_core_rate_protect(clk->core);
2671 clk_prepare_unlock();
2675 EXPORT_SYMBOL_GPL(clk_set_phase);
2677 static int clk_core_get_phase(struct clk_core *core)
2681 lockdep_assert_held(&prepare_lock);
2682 if (!core->ops->get_phase)
2685 /* Always try to update cached phase if possible */
2686 ret = core->ops->get_phase(core->hw);
2694 * clk_get_phase - return the phase shift of a clock signal
2695 * @clk: clock signal source
2697 * Returns the phase shift of a clock node in degrees, otherwise returns
2700 int clk_get_phase(struct clk *clk)
2708 ret = clk_core_get_phase(clk->core);
2709 clk_prepare_unlock();
2713 EXPORT_SYMBOL_GPL(clk_get_phase);
2715 static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
2717 /* Assume a default value of 50% */
2722 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);
2724 static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
2726 struct clk_duty *duty = &core->duty;
2729 if (!core->ops->get_duty_cycle)
2730 return clk_core_update_duty_cycle_parent_nolock(core);
2732 ret = core->ops->get_duty_cycle(core->hw, duty);
2736 /* Don't trust the clock provider too much */
2737 if (duty->den == 0 || duty->num > duty->den) {
2745 clk_core_reset_duty_cycle_nolock(core);
2749 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
2754 core->flags & CLK_DUTY_CYCLE_PARENT) {
2755 ret = clk_core_update_duty_cycle_nolock(core->parent);
2756 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
2758 clk_core_reset_duty_cycle_nolock(core);
2764 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
2765 struct clk_duty *duty);
2767 static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
2768 struct clk_duty *duty)
2772 lockdep_assert_held(&prepare_lock);
2774 if (clk_core_rate_is_protected(core))
2777 trace_clk_set_duty_cycle(core, duty);
2779 if (!core->ops->set_duty_cycle)
2780 return clk_core_set_duty_cycle_parent_nolock(core, duty);
2782 ret = core->ops->set_duty_cycle(core->hw, duty);
2784 memcpy(&core->duty, duty, sizeof(*duty));
2786 trace_clk_set_duty_cycle_complete(core, duty);
2791 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
2792 struct clk_duty *duty)
2797 core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
2798 ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
2799 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
2806 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
2807 * @clk: clock signal source
2808 * @num: numerator of the duty cycle ratio to be applied
2809 * @den: denominator of the duty cycle ratio to be applied
2811 * Apply the duty cycle ratio if the ratio is valid and the clock can
2812 * perform this operation
2814 * Returns (0) on success, a negative errno otherwise.
2816 int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
2819 struct clk_duty duty;
2824 /* sanity check the ratio */
2825 if (den == 0 || num > den)
2833 if (clk->exclusive_count)
2834 clk_core_rate_unprotect(clk->core);
2836 ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
2838 if (clk->exclusive_count)
2839 clk_core_rate_protect(clk->core);
2841 clk_prepare_unlock();
2845 EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
2847 static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
2850 struct clk_duty *duty = &core->duty;
2855 ret = clk_core_update_duty_cycle_nolock(core);
2857 ret = mult_frac(scale, duty->num, duty->den);
2859 clk_prepare_unlock();
2865 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
2866 * @clk: clock signal source
2867 * @scale: scaling factor to be applied to represent the ratio as an integer
2869 * Returns the duty cycle ratio of a clock node multiplied by the provided
2870 * scaling factor, or negative errno on error.
2872 int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
2877 return clk_core_get_scaled_duty_cycle(clk->core, scale);
2879 EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
2882 * clk_is_match - check if two clk's point to the same hardware clock
2883 * @p: clk compared against q
2884 * @q: clk compared against p
2886 * Returns true if the two struct clk pointers both point to the same hardware
2887 * clock node. Put differently, returns true if struct clk *p and struct clk *q
2888 * share the same struct clk_core object.
2890 * Returns false otherwise. Note that two NULL clks are treated as matching.
2892 bool clk_is_match(const struct clk *p, const struct clk *q)
2894 /* trivial case: identical struct clk's or both NULL */
2898 /* true if clk->core pointers match. Avoid dereferencing garbage */
2899 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
2900 if (p->core == q->core)
2905 EXPORT_SYMBOL_GPL(clk_is_match);
2907 /*** debugfs support ***/
2909 #ifdef CONFIG_DEBUG_FS
2910 #include <linux/debugfs.h>
2912 static struct dentry *rootdir;
2913 static int inited = 0;
2914 static DEFINE_MUTEX(clk_debug_lock);
2915 static HLIST_HEAD(clk_debug_list);
2917 static struct hlist_head *orphan_list[] = {
2922 static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
2927 seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu ",
2929 30 - level * 3, c->name,
2930 c->enable_count, c->prepare_count, c->protect_count,
2931 clk_core_get_rate_recalc(c),
2932 clk_core_get_accuracy_recalc(c));
2934 phase = clk_core_get_phase(c);
2936 seq_printf(s, "%5d", phase);
2938 seq_puts(s, "-----");
2940 seq_printf(s, " %6d\n", clk_core_get_scaled_duty_cycle(c, 100000));
2943 static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
2946 struct clk_core *child;
2948 clk_summary_show_one(s, c, level);
2950 hlist_for_each_entry(child, &c->children, child_node)
2951 clk_summary_show_subtree(s, child, level + 1);
2954 static int clk_summary_show(struct seq_file *s, void *data)
2957 struct hlist_head **lists = (struct hlist_head **)s->private;
2959 seq_puts(s, " enable prepare protect duty\n");
2960 seq_puts(s, " clock count count count rate accuracy phase cycle\n");
2961 seq_puts(s, "---------------------------------------------------------------------------------------------\n");
2965 for (; *lists; lists++)
2966 hlist_for_each_entry(c, *lists, child_node)
2967 clk_summary_show_subtree(s, c, 0);
2969 clk_prepare_unlock();
2973 DEFINE_SHOW_ATTRIBUTE(clk_summary);
2975 static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
2978 unsigned long min_rate, max_rate;
2980 clk_core_get_boundaries(c, &min_rate, &max_rate);
2982 /* This should be JSON format, i.e. elements separated with a comma */
2983 seq_printf(s, "\"%s\": { ", c->name);
2984 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
2985 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
2986 seq_printf(s, "\"protect_count\": %d,", c->protect_count);
2987 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate_recalc(c));
2988 seq_printf(s, "\"min_rate\": %lu,", min_rate);
2989 seq_printf(s, "\"max_rate\": %lu,", max_rate);
2990 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy_recalc(c));
2991 phase = clk_core_get_phase(c);
2993 seq_printf(s, "\"phase\": %d,", phase);
2994 seq_printf(s, "\"duty_cycle\": %u",
2995 clk_core_get_scaled_duty_cycle(c, 100000));
2998 static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
3000 struct clk_core *child;
3002 clk_dump_one(s, c, level);
3004 hlist_for_each_entry(child, &c->children, child_node) {
3006 clk_dump_subtree(s, child, level + 1);
3012 static int clk_dump_show(struct seq_file *s, void *data)
3015 bool first_node = true;
3016 struct hlist_head **lists = (struct hlist_head **)s->private;
3021 for (; *lists; lists++) {
3022 hlist_for_each_entry(c, *lists, child_node) {
3026 clk_dump_subtree(s, c, 0);
3030 clk_prepare_unlock();
3035 DEFINE_SHOW_ATTRIBUTE(clk_dump);
3037 #undef CLOCK_ALLOW_WRITE_DEBUGFS
3038 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3040 * This can be dangerous, therefore don't provide any real compile time
3041 * configuration option for this feature.
3042 * People who want to use this will need to modify the source code directly.
3044 static int clk_rate_set(void *data, u64 val)
3046 struct clk_core *core = data;
3050 ret = clk_core_set_rate_nolock(core, val);
3051 clk_prepare_unlock();
3056 #define clk_rate_mode 0644
3058 #define clk_rate_set NULL
3059 #define clk_rate_mode 0444
3062 static int clk_rate_get(void *data, u64 *val)
3064 struct clk_core *core = data;
3070 DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops, clk_rate_get, clk_rate_set, "%llu\n");
3072 static const struct {
3076 #define ENTRY(f) { f, #f }
3077 ENTRY(CLK_SET_RATE_GATE),
3078 ENTRY(CLK_SET_PARENT_GATE),
3079 ENTRY(CLK_SET_RATE_PARENT),
3080 ENTRY(CLK_IGNORE_UNUSED),
3081 ENTRY(CLK_GET_RATE_NOCACHE),
3082 ENTRY(CLK_SET_RATE_NO_REPARENT),
3083 ENTRY(CLK_GET_ACCURACY_NOCACHE),
3084 ENTRY(CLK_RECALC_NEW_RATES),
3085 ENTRY(CLK_SET_RATE_UNGATE),
3086 ENTRY(CLK_IS_CRITICAL),
3087 ENTRY(CLK_OPS_PARENT_ENABLE),
3088 ENTRY(CLK_DUTY_CYCLE_PARENT),
3092 static int clk_flags_show(struct seq_file *s, void *data)
3094 struct clk_core *core = s->private;
3095 unsigned long flags = core->flags;
3098 for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
3099 if (flags & clk_flags[i].flag) {
3100 seq_printf(s, "%s\n", clk_flags[i].name);
3101 flags &= ~clk_flags[i].flag;
3106 seq_printf(s, "0x%lx\n", flags);
3111 DEFINE_SHOW_ATTRIBUTE(clk_flags);
3113 static void possible_parent_show(struct seq_file *s, struct clk_core *core,
3114 unsigned int i, char terminator)
3116 struct clk_core *parent;
3119 * Go through the following options to fetch a parent's name.
3121 * 1. Fetch the registered parent clock and use its name
3122 * 2. Use the global (fallback) name if specified
3123 * 3. Use the local fw_name if provided
3124 * 4. Fetch parent clock's clock-output-name if DT index was set
3126 * This may still fail in some cases, such as when the parent is
3127 * specified directly via a struct clk_hw pointer, but it isn't
3130 parent = clk_core_get_parent_by_index(core, i);
3132 seq_puts(s, parent->name);
3133 else if (core->parents[i].name)
3134 seq_puts(s, core->parents[i].name);
3135 else if (core->parents[i].fw_name)
3136 seq_printf(s, "<%s>(fw)", core->parents[i].fw_name);
3137 else if (core->parents[i].index >= 0)
3139 of_clk_get_parent_name(core->of_node,
3140 core->parents[i].index));
3142 seq_puts(s, "(missing)");
3144 seq_putc(s, terminator);
3147 static int possible_parents_show(struct seq_file *s, void *data)
3149 struct clk_core *core = s->private;
3152 for (i = 0; i < core->num_parents - 1; i++)
3153 possible_parent_show(s, core, i, ' ');
3155 possible_parent_show(s, core, i, '\n');
3159 DEFINE_SHOW_ATTRIBUTE(possible_parents);
3161 static int current_parent_show(struct seq_file *s, void *data)
3163 struct clk_core *core = s->private;
3166 seq_printf(s, "%s\n", core->parent->name);
3170 DEFINE_SHOW_ATTRIBUTE(current_parent);
3172 static int clk_duty_cycle_show(struct seq_file *s, void *data)
3174 struct clk_core *core = s->private;
3175 struct clk_duty *duty = &core->duty;
3177 seq_printf(s, "%u/%u\n", duty->num, duty->den);
3181 DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
3183 static int clk_min_rate_show(struct seq_file *s, void *data)
3185 struct clk_core *core = s->private;
3186 unsigned long min_rate, max_rate;
3189 clk_core_get_boundaries(core, &min_rate, &max_rate);
3190 clk_prepare_unlock();
3191 seq_printf(s, "%lu\n", min_rate);
3195 DEFINE_SHOW_ATTRIBUTE(clk_min_rate);
3197 static int clk_max_rate_show(struct seq_file *s, void *data)
3199 struct clk_core *core = s->private;
3200 unsigned long min_rate, max_rate;
3203 clk_core_get_boundaries(core, &min_rate, &max_rate);
3204 clk_prepare_unlock();
3205 seq_printf(s, "%lu\n", max_rate);
3209 DEFINE_SHOW_ATTRIBUTE(clk_max_rate);
3211 static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
3213 struct dentry *root;
3215 if (!core || !pdentry)
3218 root = debugfs_create_dir(core->name, pdentry);
3219 core->dentry = root;
3221 debugfs_create_file("clk_rate", clk_rate_mode, root, core,
3223 debugfs_create_file("clk_min_rate", 0444, root, core, &clk_min_rate_fops);
3224 debugfs_create_file("clk_max_rate", 0444, root, core, &clk_max_rate_fops);
3225 debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
3226 debugfs_create_u32("clk_phase", 0444, root, &core->phase);
3227 debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
3228 debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
3229 debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
3230 debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
3231 debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
3232 debugfs_create_file("clk_duty_cycle", 0444, root, core,
3233 &clk_duty_cycle_fops);
3235 if (core->num_parents > 0)
3236 debugfs_create_file("clk_parent", 0444, root, core,
3237 ¤t_parent_fops);
3239 if (core->num_parents > 1)
3240 debugfs_create_file("clk_possible_parents", 0444, root, core,
3241 &possible_parents_fops);
3243 if (core->ops->debug_init)
3244 core->ops->debug_init(core->hw, core->dentry);
3248 * clk_debug_register - add a clk node to the debugfs clk directory
3249 * @core: the clk being added to the debugfs clk directory
3251 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
3252 * initialized. Otherwise it bails out early since the debugfs clk directory
3253 * will be created lazily by clk_debug_init as part of a late_initcall.
3255 static void clk_debug_register(struct clk_core *core)
3257 mutex_lock(&clk_debug_lock);
3258 hlist_add_head(&core->debug_node, &clk_debug_list);
3260 clk_debug_create_one(core, rootdir);
3261 mutex_unlock(&clk_debug_lock);
3265 * clk_debug_unregister - remove a clk node from the debugfs clk directory
3266 * @core: the clk being removed from the debugfs clk directory
3268 * Dynamically removes a clk and all its child nodes from the
3269 * debugfs clk directory if clk->dentry points to debugfs created by
3270 * clk_debug_register in __clk_core_init.
3272 static void clk_debug_unregister(struct clk_core *core)
3274 mutex_lock(&clk_debug_lock);
3275 hlist_del_init(&core->debug_node);
3276 debugfs_remove_recursive(core->dentry);
3277 core->dentry = NULL;
3278 mutex_unlock(&clk_debug_lock);
3282 * clk_debug_init - lazily populate the debugfs clk directory
3284 * clks are often initialized very early during boot before memory can be
3285 * dynamically allocated and well before debugfs is setup. This function
3286 * populates the debugfs clk directory once at boot-time when we know that
3287 * debugfs is setup. It should only be called once at boot-time, all other clks
3288 * added dynamically will be done so with clk_debug_register.
3290 static int __init clk_debug_init(void)
3292 struct clk_core *core;
3294 rootdir = debugfs_create_dir("clk", NULL);
3296 debugfs_create_file("clk_summary", 0444, rootdir, &all_lists,
3298 debugfs_create_file("clk_dump", 0444, rootdir, &all_lists,
3300 debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list,
3302 debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list,
3305 mutex_lock(&clk_debug_lock);
3306 hlist_for_each_entry(core, &clk_debug_list, debug_node)
3307 clk_debug_create_one(core, rootdir);
3310 mutex_unlock(&clk_debug_lock);
3314 late_initcall(clk_debug_init);
3316 static inline void clk_debug_register(struct clk_core *core) { }
3317 static inline void clk_debug_unregister(struct clk_core *core)
3322 static void clk_core_reparent_orphans_nolock(void)
3324 struct clk_core *orphan;
3325 struct hlist_node *tmp2;
3328 * walk the list of orphan clocks and reparent any that newly finds a
3331 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
3332 struct clk_core *parent = __clk_init_parent(orphan);
3335 * We need to use __clk_set_parent_before() and _after() to
3336 * to properly migrate any prepare/enable count of the orphan
3337 * clock. This is important for CLK_IS_CRITICAL clocks, which
3338 * are enabled during init but might not have a parent yet.
3341 /* update the clk tree topology */
3342 __clk_set_parent_before(orphan, parent);
3343 __clk_set_parent_after(orphan, parent, NULL);
3344 __clk_recalc_accuracies(orphan);
3345 __clk_recalc_rates(orphan, 0);
3351 * __clk_core_init - initialize the data structures in a struct clk_core
3352 * @core: clk_core being initialized
3354 * Initializes the lists in struct clk_core, queries the hardware for the
3355 * parent and rate and sets them both.
3357 static int __clk_core_init(struct clk_core *core)
3360 struct clk_core *parent;
3369 ret = clk_pm_runtime_get(core);
3373 /* check to see if a clock with this name is already registered */
3374 if (clk_core_lookup(core->name)) {
3375 pr_debug("%s: clk %s already initialized\n",
3376 __func__, core->name);
3381 /* check that clk_ops are sane. See Documentation/driver-api/clk.rst */
3382 if (core->ops->set_rate &&
3383 !((core->ops->round_rate || core->ops->determine_rate) &&
3384 core->ops->recalc_rate)) {
3385 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
3386 __func__, core->name);
3391 if (core->ops->set_parent && !core->ops->get_parent) {
3392 pr_err("%s: %s must implement .get_parent & .set_parent\n",
3393 __func__, core->name);
3398 if (core->num_parents > 1 && !core->ops->get_parent) {
3399 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
3400 __func__, core->name);
3405 if (core->ops->set_rate_and_parent &&
3406 !(core->ops->set_parent && core->ops->set_rate)) {
3407 pr_err("%s: %s must implement .set_parent & .set_rate\n",
3408 __func__, core->name);
3414 * optional platform-specific magic
3416 * The .init callback is not used by any of the basic clock types, but
3417 * exists for weird hardware that must perform initialization magic for
3418 * CCF to get an accurate view of clock for any other callbacks. It may
3419 * also be used needs to perform dynamic allocations. Such allocation
3420 * must be freed in the terminate() callback.
3421 * This callback shall not be used to initialize the parameters state,
3422 * such as rate, parent, etc ...
3424 * If it exist, this callback should called before any other callback of
3427 if (core->ops->init) {
3428 ret = core->ops->init(core->hw);
3433 parent = core->parent = __clk_init_parent(core);
3436 * Populate core->parent if parent has already been clk_core_init'd. If
3437 * parent has not yet been clk_core_init'd then place clk in the orphan
3438 * list. If clk doesn't have any parents then place it in the root
3441 * Every time a new clk is clk_init'd then we walk the list of orphan
3442 * clocks and re-parent any that are children of the clock currently
3446 hlist_add_head(&core->child_node, &parent->children);
3447 core->orphan = parent->orphan;
3448 } else if (!core->num_parents) {
3449 hlist_add_head(&core->child_node, &clk_root_list);
3450 core->orphan = false;
3452 hlist_add_head(&core->child_node, &clk_orphan_list);
3453 core->orphan = true;
3457 * Set clk's accuracy. The preferred method is to use
3458 * .recalc_accuracy. For simple clocks and lazy developers the default
3459 * fallback is to use the parent's accuracy. If a clock doesn't have a
3460 * parent (or is orphaned) then accuracy is set to zero (perfect
3463 if (core->ops->recalc_accuracy)
3464 core->accuracy = core->ops->recalc_accuracy(core->hw,
3465 clk_core_get_accuracy_no_lock(parent));
3467 core->accuracy = parent->accuracy;
3472 * Set clk's phase by clk_core_get_phase() caching the phase.
3473 * Since a phase is by definition relative to its parent, just
3474 * query the current clock phase, or just assume it's in phase.
3476 phase = clk_core_get_phase(core);
3479 pr_warn("%s: Failed to get phase for clk '%s'\n", __func__,
3485 * Set clk's duty cycle.
3487 clk_core_update_duty_cycle_nolock(core);
3490 * Set clk's rate. The preferred method is to use .recalc_rate. For
3491 * simple clocks and lazy developers the default fallback is to use the
3492 * parent's rate. If a clock doesn't have a parent (or is orphaned)
3493 * then rate is set to zero.
3495 if (core->ops->recalc_rate)
3496 rate = core->ops->recalc_rate(core->hw,
3497 clk_core_get_rate_nolock(parent));
3499 rate = parent->rate;
3502 core->rate = core->req_rate = rate;
3505 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
3506 * don't get accidentally disabled when walking the orphan tree and
3507 * reparenting clocks
3509 if (core->flags & CLK_IS_CRITICAL) {
3510 unsigned long flags;
3512 ret = clk_core_prepare(core);
3514 pr_warn("%s: critical clk '%s' failed to prepare\n",
3515 __func__, core->name);
3519 flags = clk_enable_lock();
3520 ret = clk_core_enable(core);
3521 clk_enable_unlock(flags);
3523 pr_warn("%s: critical clk '%s' failed to enable\n",
3524 __func__, core->name);
3525 clk_core_unprepare(core);
3530 clk_core_reparent_orphans_nolock();
3533 kref_init(&core->ref);
3535 clk_pm_runtime_put(core);
3538 hlist_del_init(&core->child_node);
3540 clk_prepare_unlock();
3543 clk_debug_register(core);
3549 * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core
3550 * @core: clk to add consumer to
3551 * @clk: consumer to link to a clk
3553 static void clk_core_link_consumer(struct clk_core *core, struct clk *clk)
3556 hlist_add_head(&clk->clks_node, &core->clks);
3557 clk_prepare_unlock();
3561 * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core
3562 * @clk: consumer to unlink
3564 static void clk_core_unlink_consumer(struct clk *clk)
3566 lockdep_assert_held(&prepare_lock);
3567 hlist_del(&clk->clks_node);
3571 * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core
3572 * @core: clk to allocate a consumer for
3573 * @dev_id: string describing device name
3574 * @con_id: connection ID string on device
3576 * Returns: clk consumer left unlinked from the consumer list
3578 static struct clk *alloc_clk(struct clk_core *core, const char *dev_id,
3583 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
3585 return ERR_PTR(-ENOMEM);
3588 clk->dev_id = dev_id;
3589 clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
3590 clk->max_rate = ULONG_MAX;
3596 * free_clk - Free a clk consumer
3597 * @clk: clk consumer to free
3599 * Note, this assumes the clk has been unlinked from the clk_core consumer
3602 static void free_clk(struct clk *clk)
3604 kfree_const(clk->con_id);
3609 * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given
3611 * @dev: clk consumer device
3612 * @hw: clk_hw associated with the clk being consumed
3613 * @dev_id: string describing device name
3614 * @con_id: connection ID string on device
3616 * This is the main function used to create a clk pointer for use by clk
3617 * consumers. It connects a consumer to the clk_core and clk_hw structures
3618 * used by the framework and clk provider respectively.
3620 struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
3621 const char *dev_id, const char *con_id)
3624 struct clk_core *core;
3626 /* This is to allow this function to be chained to others */
3627 if (IS_ERR_OR_NULL(hw))
3628 return ERR_CAST(hw);
3631 clk = alloc_clk(core, dev_id, con_id);
3636 if (!try_module_get(core->owner)) {
3638 return ERR_PTR(-ENOENT);
3641 kref_get(&core->ref);
3642 clk_core_link_consumer(core, clk);
3647 static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
3657 *dst_p = dst = kstrdup_const(src, GFP_KERNEL);
3664 static int clk_core_populate_parent_map(struct clk_core *core,
3665 const struct clk_init_data *init)
3667 u8 num_parents = init->num_parents;
3668 const char * const *parent_names = init->parent_names;
3669 const struct clk_hw **parent_hws = init->parent_hws;
3670 const struct clk_parent_data *parent_data = init->parent_data;
3672 struct clk_parent_map *parents, *parent;
3678 * Avoid unnecessary string look-ups of clk_core's possible parents by
3679 * having a cache of names/clk_hw pointers to clk_core pointers.
3681 parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
3682 core->parents = parents;
3686 /* Copy everything over because it might be __initdata */
3687 for (i = 0, parent = parents; i < num_parents; i++, parent++) {
3690 /* throw a WARN if any entries are NULL */
3691 WARN(!parent_names[i],
3692 "%s: invalid NULL in %s's .parent_names\n",
3693 __func__, core->name);
3694 ret = clk_cpy_name(&parent->name, parent_names[i],
3696 } else if (parent_data) {
3697 parent->hw = parent_data[i].hw;
3698 parent->index = parent_data[i].index;
3699 ret = clk_cpy_name(&parent->fw_name,
3700 parent_data[i].fw_name, false);
3702 ret = clk_cpy_name(&parent->name,
3703 parent_data[i].name,
3705 } else if (parent_hws) {
3706 parent->hw = parent_hws[i];
3709 WARN(1, "Must specify parents if num_parents > 0\n");
3714 kfree_const(parents[i].name);
3715 kfree_const(parents[i].fw_name);
3726 static void clk_core_free_parent_map(struct clk_core *core)
3728 int i = core->num_parents;
3730 if (!core->num_parents)
3734 kfree_const(core->parents[i].name);
3735 kfree_const(core->parents[i].fw_name);
3738 kfree(core->parents);
3742 __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
3745 struct clk_core *core;
3746 const struct clk_init_data *init = hw->init;
3749 * The init data is not supposed to be used outside of registration path.
3750 * Set it to NULL so that provider drivers can't use it either and so that
3751 * we catch use of hw->init early on in the core.
3755 core = kzalloc(sizeof(*core), GFP_KERNEL);
3761 core->name = kstrdup_const(init->name, GFP_KERNEL);
3767 if (WARN_ON(!init->ops)) {
3771 core->ops = init->ops;
3773 if (dev && pm_runtime_enabled(dev))
3774 core->rpm_enabled = true;
3777 if (dev && dev->driver)
3778 core->owner = dev->driver->owner;
3780 core->flags = init->flags;
3781 core->num_parents = init->num_parents;
3783 core->max_rate = ULONG_MAX;
3786 ret = clk_core_populate_parent_map(core, init);
3790 INIT_HLIST_HEAD(&core->clks);
3793 * Don't call clk_hw_create_clk() here because that would pin the
3794 * provider module to itself and prevent it from ever being removed.
3796 hw->clk = alloc_clk(core, NULL, NULL);
3797 if (IS_ERR(hw->clk)) {
3798 ret = PTR_ERR(hw->clk);
3799 goto fail_create_clk;
3802 clk_core_link_consumer(hw->core, hw->clk);
3804 ret = __clk_core_init(core);
3809 clk_core_unlink_consumer(hw->clk);
3810 clk_prepare_unlock();
3816 clk_core_free_parent_map(core);
3819 kfree_const(core->name);
3823 return ERR_PTR(ret);
3827 * dev_or_parent_of_node() - Get device node of @dev or @dev's parent
3828 * @dev: Device to get device node of
3830 * Return: device node pointer of @dev, or the device node pointer of
3831 * @dev->parent if dev doesn't have a device node, or NULL if neither
3832 * @dev or @dev->parent have a device node.
3834 static struct device_node *dev_or_parent_of_node(struct device *dev)
3836 struct device_node *np;
3841 np = dev_of_node(dev);
3843 np = dev_of_node(dev->parent);
3849 * clk_register - allocate a new clock, register it and return an opaque cookie
3850 * @dev: device that is registering this clock
3851 * @hw: link to hardware-specific clock data
3853 * clk_register is the *deprecated* interface for populating the clock tree with
3854 * new clock nodes. Use clk_hw_register() instead.
3856 * Returns: a pointer to the newly allocated struct clk which
3857 * cannot be dereferenced by driver code but may be used in conjunction with the
3858 * rest of the clock API. In the event of an error clk_register will return an
3859 * error code; drivers must test for an error code after calling clk_register.
3861 struct clk *clk_register(struct device *dev, struct clk_hw *hw)
3863 return __clk_register(dev, dev_or_parent_of_node(dev), hw);
3865 EXPORT_SYMBOL_GPL(clk_register);
3868 * clk_hw_register - register a clk_hw and return an error code
3869 * @dev: device that is registering this clock
3870 * @hw: link to hardware-specific clock data
3872 * clk_hw_register is the primary interface for populating the clock tree with
3873 * new clock nodes. It returns an integer equal to zero indicating success or
3874 * less than zero indicating failure. Drivers must test for an error code after
3875 * calling clk_hw_register().
3877 int clk_hw_register(struct device *dev, struct clk_hw *hw)
3879 return PTR_ERR_OR_ZERO(__clk_register(dev, dev_or_parent_of_node(dev),
3882 EXPORT_SYMBOL_GPL(clk_hw_register);
3885 * of_clk_hw_register - register a clk_hw and return an error code
3886 * @node: device_node of device that is registering this clock
3887 * @hw: link to hardware-specific clock data
3889 * of_clk_hw_register() is the primary interface for populating the clock tree
3890 * with new clock nodes when a struct device is not available, but a struct
3891 * device_node is. It returns an integer equal to zero indicating success or
3892 * less than zero indicating failure. Drivers must test for an error code after
3893 * calling of_clk_hw_register().
3895 int of_clk_hw_register(struct device_node *node, struct clk_hw *hw)
3897 return PTR_ERR_OR_ZERO(__clk_register(NULL, node, hw));
3899 EXPORT_SYMBOL_GPL(of_clk_hw_register);
3901 /* Free memory allocated for a clock. */
3902 static void __clk_release(struct kref *ref)
3904 struct clk_core *core = container_of(ref, struct clk_core, ref);
3906 lockdep_assert_held(&prepare_lock);
3908 clk_core_free_parent_map(core);
3909 kfree_const(core->name);
3914 * Empty clk_ops for unregistered clocks. These are used temporarily
3915 * after clk_unregister() was called on a clock and until last clock
3916 * consumer calls clk_put() and the struct clk object is freed.
3918 static int clk_nodrv_prepare_enable(struct clk_hw *hw)
3923 static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
3928 static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
3929 unsigned long parent_rate)
3934 static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
3939 static const struct clk_ops clk_nodrv_ops = {
3940 .enable = clk_nodrv_prepare_enable,
3941 .disable = clk_nodrv_disable_unprepare,
3942 .prepare = clk_nodrv_prepare_enable,
3943 .unprepare = clk_nodrv_disable_unprepare,
3944 .set_rate = clk_nodrv_set_rate,
3945 .set_parent = clk_nodrv_set_parent,
3948 static void clk_core_evict_parent_cache_subtree(struct clk_core *root,
3949 struct clk_core *target)
3952 struct clk_core *child;
3954 for (i = 0; i < root->num_parents; i++)
3955 if (root->parents[i].core == target)
3956 root->parents[i].core = NULL;
3958 hlist_for_each_entry(child, &root->children, child_node)
3959 clk_core_evict_parent_cache_subtree(child, target);
3962 /* Remove this clk from all parent caches */
3963 static void clk_core_evict_parent_cache(struct clk_core *core)
3965 struct hlist_head **lists;
3966 struct clk_core *root;
3968 lockdep_assert_held(&prepare_lock);
3970 for (lists = all_lists; *lists; lists++)
3971 hlist_for_each_entry(root, *lists, child_node)
3972 clk_core_evict_parent_cache_subtree(root, core);
3977 * clk_unregister - unregister a currently registered clock
3978 * @clk: clock to unregister
3980 void clk_unregister(struct clk *clk)
3982 unsigned long flags;
3983 const struct clk_ops *ops;
3985 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
3988 clk_debug_unregister(clk->core);
3992 ops = clk->core->ops;
3993 if (ops == &clk_nodrv_ops) {
3994 pr_err("%s: unregistered clock: %s\n", __func__,
3999 * Assign empty clock ops for consumers that might still hold
4000 * a reference to this clock.
4002 flags = clk_enable_lock();
4003 clk->core->ops = &clk_nodrv_ops;
4004 clk_enable_unlock(flags);
4007 ops->terminate(clk->core->hw);
4009 if (!hlist_empty(&clk->core->children)) {
4010 struct clk_core *child;
4011 struct hlist_node *t;
4013 /* Reparent all children to the orphan list. */
4014 hlist_for_each_entry_safe(child, t, &clk->core->children,
4016 clk_core_set_parent_nolock(child, NULL);
4019 clk_core_evict_parent_cache(clk->core);
4021 hlist_del_init(&clk->core->child_node);
4023 if (clk->core->prepare_count)
4024 pr_warn("%s: unregistering prepared clock: %s\n",
4025 __func__, clk->core->name);
4027 if (clk->core->protect_count)
4028 pr_warn("%s: unregistering protected clock: %s\n",
4029 __func__, clk->core->name);
4031 kref_put(&clk->core->ref, __clk_release);
4034 clk_prepare_unlock();
4036 EXPORT_SYMBOL_GPL(clk_unregister);
4039 * clk_hw_unregister - unregister a currently registered clk_hw
4040 * @hw: hardware-specific clock data to unregister
4042 void clk_hw_unregister(struct clk_hw *hw)
4044 clk_unregister(hw->clk);
4046 EXPORT_SYMBOL_GPL(clk_hw_unregister);
4048 static void devm_clk_release(struct device *dev, void *res)
4050 clk_unregister(*(struct clk **)res);
4053 static void devm_clk_hw_release(struct device *dev, void *res)
4055 clk_hw_unregister(*(struct clk_hw **)res);
4059 * devm_clk_register - resource managed clk_register()
4060 * @dev: device that is registering this clock
4061 * @hw: link to hardware-specific clock data
4063 * Managed clk_register(). This function is *deprecated*, use devm_clk_hw_register() instead.
4065 * Clocks returned from this function are automatically clk_unregister()ed on
4066 * driver detach. See clk_register() for more information.
4068 struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
4073 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
4075 return ERR_PTR(-ENOMEM);
4077 clk = clk_register(dev, hw);
4080 devres_add(dev, clkp);
4087 EXPORT_SYMBOL_GPL(devm_clk_register);
4090 * devm_clk_hw_register - resource managed clk_hw_register()
4091 * @dev: device that is registering this clock
4092 * @hw: link to hardware-specific clock data
4094 * Managed clk_hw_register(). Clocks registered by this function are
4095 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
4096 * for more information.
4098 int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
4100 struct clk_hw **hwp;
4103 hwp = devres_alloc(devm_clk_hw_release, sizeof(*hwp), GFP_KERNEL);
4107 ret = clk_hw_register(dev, hw);
4110 devres_add(dev, hwp);
4117 EXPORT_SYMBOL_GPL(devm_clk_hw_register);
4119 static int devm_clk_match(struct device *dev, void *res, void *data)
4121 struct clk *c = res;
4127 static int devm_clk_hw_match(struct device *dev, void *res, void *data)
4129 struct clk_hw *hw = res;
4137 * devm_clk_unregister - resource managed clk_unregister()
4138 * @clk: clock to unregister
4140 * Deallocate a clock allocated with devm_clk_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_unregister(struct device *dev, struct clk *clk)
4146 WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
4148 EXPORT_SYMBOL_GPL(devm_clk_unregister);
4151 * devm_clk_hw_unregister - resource managed clk_hw_unregister()
4152 * @dev: device that is unregistering the hardware-specific clock data
4153 * @hw: link to hardware-specific clock data
4155 * Unregister a clk_hw registered with devm_clk_hw_register(). Normally
4156 * this function will not need to be called and the resource management
4157 * code will ensure that the resource is freed.
4159 void devm_clk_hw_unregister(struct device *dev, struct clk_hw *hw)
4161 WARN_ON(devres_release(dev, devm_clk_hw_release, devm_clk_hw_match,
4164 EXPORT_SYMBOL_GPL(devm_clk_hw_unregister);
4170 void __clk_put(struct clk *clk)
4172 struct module *owner;
4174 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4180 * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
4181 * given user should be balanced with calls to clk_rate_exclusive_put()
4182 * and by that same consumer
4184 if (WARN_ON(clk->exclusive_count)) {
4185 /* We voiced our concern, let's sanitize the situation */
4186 clk->core->protect_count -= (clk->exclusive_count - 1);
4187 clk_core_rate_unprotect(clk->core);
4188 clk->exclusive_count = 0;
4191 hlist_del(&clk->clks_node);
4192 if (clk->min_rate > clk->core->req_rate ||
4193 clk->max_rate < clk->core->req_rate)
4194 clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
4196 owner = clk->core->owner;
4197 kref_put(&clk->core->ref, __clk_release);
4199 clk_prepare_unlock();
4206 /*** clk rate change notifiers ***/
4209 * clk_notifier_register - add a clk rate change notifier
4210 * @clk: struct clk * to watch
4211 * @nb: struct notifier_block * with callback info
4213 * Request notification when clk's rate changes. This uses an SRCU
4214 * notifier because we want it to block and notifier unregistrations are
4215 * uncommon. The callbacks associated with the notifier must not
4216 * re-enter into the clk framework by calling any top-level clk APIs;
4217 * this will cause a nested prepare_lock mutex.
4219 * In all notification cases (pre, post and abort rate change) the original
4220 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
4221 * and the new frequency is passed via struct clk_notifier_data.new_rate.
4223 * clk_notifier_register() must be called from non-atomic context.
4224 * Returns -EINVAL if called with null arguments, -ENOMEM upon
4225 * allocation failure; otherwise, passes along the return value of
4226 * srcu_notifier_chain_register().
4228 int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
4230 struct clk_notifier *cn;
4238 /* search the list of notifiers for this clk */
4239 list_for_each_entry(cn, &clk_notifier_list, node)
4243 /* if clk wasn't in the notifier list, allocate new clk_notifier */
4244 if (cn->clk != clk) {
4245 cn = kzalloc(sizeof(*cn), GFP_KERNEL);
4250 srcu_init_notifier_head(&cn->notifier_head);
4252 list_add(&cn->node, &clk_notifier_list);
4255 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
4257 clk->core->notifier_count++;
4260 clk_prepare_unlock();
4264 EXPORT_SYMBOL_GPL(clk_notifier_register);
4267 * clk_notifier_unregister - remove a clk rate change notifier
4268 * @clk: struct clk *
4269 * @nb: struct notifier_block * with callback info
4271 * Request no further notification for changes to 'clk' and frees memory
4272 * allocated in clk_notifier_register.
4274 * Returns -EINVAL if called with null arguments; otherwise, passes
4275 * along the return value of srcu_notifier_chain_unregister().
4277 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
4279 struct clk_notifier *cn = NULL;
4287 list_for_each_entry(cn, &clk_notifier_list, node)
4291 if (cn->clk == clk) {
4292 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
4294 clk->core->notifier_count--;
4296 /* XXX the notifier code should handle this better */
4297 if (!cn->notifier_head.head) {
4298 srcu_cleanup_notifier_head(&cn->notifier_head);
4299 list_del(&cn->node);
4307 clk_prepare_unlock();
4311 EXPORT_SYMBOL_GPL(clk_notifier_unregister);
4314 static void clk_core_reparent_orphans(void)
4317 clk_core_reparent_orphans_nolock();
4318 clk_prepare_unlock();
4322 * struct of_clk_provider - Clock provider registration structure
4323 * @link: Entry in global list of clock providers
4324 * @node: Pointer to device tree node of clock provider
4325 * @get: Get clock callback. Returns NULL or a struct clk for the
4326 * given clock specifier
4327 * @data: context pointer to be passed into @get callback
4329 struct of_clk_provider {
4330 struct list_head link;
4332 struct device_node *node;
4333 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
4334 struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
4338 extern struct of_device_id __clk_of_table;
4339 static const struct of_device_id __clk_of_table_sentinel
4340 __used __section(__clk_of_table_end);
4342 static LIST_HEAD(of_clk_providers);
4343 static DEFINE_MUTEX(of_clk_mutex);
4345 struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
4350 EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
4352 struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
4356 EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
4358 struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
4360 struct clk_onecell_data *clk_data = data;
4361 unsigned int idx = clkspec->args[0];
4363 if (idx >= clk_data->clk_num) {
4364 pr_err("%s: invalid clock index %u\n", __func__, idx);
4365 return ERR_PTR(-EINVAL);
4368 return clk_data->clks[idx];
4370 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
4373 of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
4375 struct clk_hw_onecell_data *hw_data = data;
4376 unsigned int idx = clkspec->args[0];
4378 if (idx >= hw_data->num) {
4379 pr_err("%s: invalid index %u\n", __func__, idx);
4380 return ERR_PTR(-EINVAL);
4383 return hw_data->hws[idx];
4385 EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
4388 * of_clk_add_provider() - Register a clock provider for a node
4389 * @np: Device node pointer associated with clock provider
4390 * @clk_src_get: callback for decoding clock
4391 * @data: context pointer for @clk_src_get callback.
4393 * This function is *deprecated*. Use of_clk_add_hw_provider() instead.
4395 int of_clk_add_provider(struct device_node *np,
4396 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
4400 struct of_clk_provider *cp;
4403 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
4407 cp->node = of_node_get(np);
4409 cp->get = clk_src_get;
4411 mutex_lock(&of_clk_mutex);
4412 list_add(&cp->link, &of_clk_providers);
4413 mutex_unlock(&of_clk_mutex);
4414 pr_debug("Added clock from %pOF\n", np);
4416 clk_core_reparent_orphans();
4418 ret = of_clk_set_defaults(np, true);
4420 of_clk_del_provider(np);
4424 EXPORT_SYMBOL_GPL(of_clk_add_provider);
4427 * of_clk_add_hw_provider() - Register a clock provider for a node
4428 * @np: Device node pointer associated with clock provider
4429 * @get: callback for decoding clk_hw
4430 * @data: context pointer for @get callback.
4432 int of_clk_add_hw_provider(struct device_node *np,
4433 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
4437 struct of_clk_provider *cp;
4440 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
4444 cp->node = of_node_get(np);
4448 mutex_lock(&of_clk_mutex);
4449 list_add(&cp->link, &of_clk_providers);
4450 mutex_unlock(&of_clk_mutex);
4451 pr_debug("Added clk_hw provider from %pOF\n", np);
4453 clk_core_reparent_orphans();
4455 ret = of_clk_set_defaults(np, true);
4457 of_clk_del_provider(np);
4461 EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
4463 static void devm_of_clk_release_provider(struct device *dev, void *res)
4465 of_clk_del_provider(*(struct device_node **)res);
4469 * We allow a child device to use its parent device as the clock provider node
4470 * for cases like MFD sub-devices where the child device driver wants to use
4471 * devm_*() APIs but not list the device in DT as a sub-node.
4473 static struct device_node *get_clk_provider_node(struct device *dev)
4475 struct device_node *np, *parent_np;
4478 parent_np = dev->parent ? dev->parent->of_node : NULL;
4480 if (!of_find_property(np, "#clock-cells", NULL))
4481 if (of_find_property(parent_np, "#clock-cells", NULL))
4488 * devm_of_clk_add_hw_provider() - Managed clk provider node registration
4489 * @dev: Device acting as the clock provider (used for DT node and lifetime)
4490 * @get: callback for decoding clk_hw
4491 * @data: context pointer for @get callback
4493 * Registers clock provider for given device's node. If the device has no DT
4494 * node or if the device node lacks of clock provider information (#clock-cells)
4495 * then the parent device's node is scanned for this information. If parent node
4496 * has the #clock-cells then it is used in registration. Provider is
4497 * automatically released at device exit.
4499 * Return: 0 on success or an errno on failure.
4501 int devm_of_clk_add_hw_provider(struct device *dev,
4502 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
4506 struct device_node **ptr, *np;
4509 ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
4514 np = get_clk_provider_node(dev);
4515 ret = of_clk_add_hw_provider(np, get, data);
4518 devres_add(dev, ptr);
4525 EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);
4528 * of_clk_del_provider() - Remove a previously registered clock provider
4529 * @np: Device node pointer associated with clock provider
4531 void of_clk_del_provider(struct device_node *np)
4533 struct of_clk_provider *cp;
4535 mutex_lock(&of_clk_mutex);
4536 list_for_each_entry(cp, &of_clk_providers, link) {
4537 if (cp->node == np) {
4538 list_del(&cp->link);
4539 of_node_put(cp->node);
4544 mutex_unlock(&of_clk_mutex);
4546 EXPORT_SYMBOL_GPL(of_clk_del_provider);
4548 static int devm_clk_provider_match(struct device *dev, void *res, void *data)
4550 struct device_node **np = res;
4552 if (WARN_ON(!np || !*np))
4559 * devm_of_clk_del_provider() - Remove clock provider registered using devm
4560 * @dev: Device to whose lifetime the clock provider was bound
4562 void devm_of_clk_del_provider(struct device *dev)
4565 struct device_node *np = get_clk_provider_node(dev);
4567 ret = devres_release(dev, devm_of_clk_release_provider,
4568 devm_clk_provider_match, np);
4572 EXPORT_SYMBOL(devm_of_clk_del_provider);
4575 * of_parse_clkspec() - Parse a DT clock specifier for a given device node
4576 * @np: device node to parse clock specifier from
4577 * @index: index of phandle to parse clock out of. If index < 0, @name is used
4578 * @name: clock name to find and parse. If name is NULL, the index is used
4579 * @out_args: Result of parsing the clock specifier
4581 * Parses a device node's "clocks" and "clock-names" properties to find the
4582 * phandle and cells for the index or name that is desired. The resulting clock
4583 * specifier is placed into @out_args, or an errno is returned when there's a
4584 * parsing error. The @index argument is ignored if @name is non-NULL.
4588 * phandle1: clock-controller@1 {
4589 * #clock-cells = <2>;
4592 * phandle2: clock-controller@2 {
4593 * #clock-cells = <1>;
4596 * clock-consumer@3 {
4597 * clocks = <&phandle1 1 2 &phandle2 3>;
4598 * clock-names = "name1", "name2";
4601 * To get a device_node for `clock-controller@2' node you may call this
4602 * function a few different ways:
4604 * of_parse_clkspec(clock-consumer@3, -1, "name2", &args);
4605 * of_parse_clkspec(clock-consumer@3, 1, NULL, &args);
4606 * of_parse_clkspec(clock-consumer@3, 1, "name2", &args);
4608 * Return: 0 upon successfully parsing the clock specifier. Otherwise, -ENOENT
4609 * if @name is NULL or -EINVAL if @name is non-NULL and it can't be found in
4610 * the "clock-names" property of @np.
4612 static int of_parse_clkspec(const struct device_node *np, int index,
4613 const char *name, struct of_phandle_args *out_args)
4617 /* Walk up the tree of devices looking for a clock property that matches */
4620 * For named clocks, first look up the name in the
4621 * "clock-names" property. If it cannot be found, then index
4622 * will be an error code and of_parse_phandle_with_args() will
4626 index = of_property_match_string(np, "clock-names", name);
4627 ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells",
4631 if (name && index >= 0)
4635 * No matching clock found on this node. If the parent node
4636 * has a "clock-ranges" property, then we can try one of its
4640 if (np && !of_get_property(np, "clock-ranges", NULL))
4648 static struct clk_hw *
4649 __of_clk_get_hw_from_provider(struct of_clk_provider *provider,
4650 struct of_phandle_args *clkspec)
4654 if (provider->get_hw)
4655 return provider->get_hw(clkspec, provider->data);
4657 clk = provider->get(clkspec, provider->data);
4659 return ERR_CAST(clk);
4660 return __clk_get_hw(clk);
4663 static struct clk_hw *
4664 of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
4666 struct of_clk_provider *provider;
4667 struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER);
4670 return ERR_PTR(-EINVAL);
4672 mutex_lock(&of_clk_mutex);
4673 list_for_each_entry(provider, &of_clk_providers, link) {
4674 if (provider->node == clkspec->np) {
4675 hw = __of_clk_get_hw_from_provider(provider, clkspec);
4680 mutex_unlock(&of_clk_mutex);
4686 * of_clk_get_from_provider() - Lookup a clock from a clock provider
4687 * @clkspec: pointer to a clock specifier data structure
4689 * This function looks up a struct clk from the registered list of clock
4690 * providers, an input is a clock specifier data structure as returned
4691 * from the of_parse_phandle_with_args() function call.
4693 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
4695 struct clk_hw *hw = of_clk_get_hw_from_clkspec(clkspec);
4697 return clk_hw_create_clk(NULL, hw, NULL, __func__);
4699 EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
4701 struct clk_hw *of_clk_get_hw(struct device_node *np, int index,
4706 struct of_phandle_args clkspec;
4708 ret = of_parse_clkspec(np, index, con_id, &clkspec);
4710 return ERR_PTR(ret);
4712 hw = of_clk_get_hw_from_clkspec(&clkspec);
4713 of_node_put(clkspec.np);
4718 static struct clk *__of_clk_get(struct device_node *np,
4719 int index, const char *dev_id,
4722 struct clk_hw *hw = of_clk_get_hw(np, index, con_id);
4724 return clk_hw_create_clk(NULL, hw, dev_id, con_id);
4727 struct clk *of_clk_get(struct device_node *np, int index)
4729 return __of_clk_get(np, index, np->full_name, NULL);
4731 EXPORT_SYMBOL(of_clk_get);
4734 * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
4735 * @np: pointer to clock consumer node
4736 * @name: name of consumer's clock input, or NULL for the first clock reference
4738 * This function parses the clocks and clock-names properties,
4739 * and uses them to look up the struct clk from the registered list of clock
4742 struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
4745 return ERR_PTR(-ENOENT);
4747 return __of_clk_get(np, 0, np->full_name, name);
4749 EXPORT_SYMBOL(of_clk_get_by_name);
4752 * of_clk_get_parent_count() - Count the number of clocks a device node has
4753 * @np: device node to count
4755 * Returns: The number of clocks that are possible parents of this node
4757 unsigned int of_clk_get_parent_count(const struct device_node *np)
4761 count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
4767 EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
4769 const char *of_clk_get_parent_name(const struct device_node *np, int index)
4771 struct of_phandle_args clkspec;
4772 struct property *prop;
4773 const char *clk_name;
4780 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
4785 index = clkspec.args_count ? clkspec.args[0] : 0;
4788 /* if there is an indices property, use it to transfer the index
4789 * specified into an array offset for the clock-output-names property.
4791 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
4798 /* We went off the end of 'clock-indices' without finding it */
4802 if (of_property_read_string_index(clkspec.np, "clock-output-names",
4806 * Best effort to get the name if the clock has been
4807 * registered with the framework. If the clock isn't
4808 * registered, we return the node name as the name of
4809 * the clock as long as #clock-cells = 0.
4811 clk = of_clk_get_from_provider(&clkspec);
4813 if (clkspec.args_count == 0)
4814 clk_name = clkspec.np->name;
4818 clk_name = __clk_get_name(clk);
4824 of_node_put(clkspec.np);
4827 EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
4830 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
4832 * @np: Device node pointer associated with clock provider
4833 * @parents: pointer to char array that hold the parents' names
4834 * @size: size of the @parents array
4836 * Return: number of parents for the clock node.
4838 int of_clk_parent_fill(struct device_node *np, const char **parents,
4843 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
4848 EXPORT_SYMBOL_GPL(of_clk_parent_fill);
4850 struct clock_provider {
4851 void (*clk_init_cb)(struct device_node *);
4852 struct device_node *np;
4853 struct list_head node;
4857 * This function looks for a parent clock. If there is one, then it
4858 * checks that the provider for this parent clock was initialized, in
4859 * this case the parent clock will be ready.
4861 static int parent_ready(struct device_node *np)
4866 struct clk *clk = of_clk_get(np, i);
4868 /* this parent is ready we can check the next one */
4875 /* at least one parent is not ready, we exit now */
4876 if (PTR_ERR(clk) == -EPROBE_DEFER)
4880 * Here we make assumption that the device tree is
4881 * written correctly. So an error means that there is
4882 * no more parent. As we didn't exit yet, then the
4883 * previous parent are ready. If there is no clock
4884 * parent, no need to wait for them, then we can
4885 * consider their absence as being ready
4892 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
4893 * @np: Device node pointer associated with clock provider
4894 * @index: clock index
4895 * @flags: pointer to top-level framework flags
4897 * Detects if the clock-critical property exists and, if so, sets the
4898 * corresponding CLK_IS_CRITICAL flag.
4900 * Do not use this function. It exists only for legacy Device Tree
4901 * bindings, such as the one-clock-per-node style that are outdated.
4902 * Those bindings typically put all clock data into .dts and the Linux
4903 * driver has no clock data, thus making it impossible to set this flag
4904 * correctly from the driver. Only those drivers may call
4905 * of_clk_detect_critical from their setup functions.
4907 * Return: error code or zero on success
4909 int of_clk_detect_critical(struct device_node *np, int index,
4910 unsigned long *flags)
4912 struct property *prop;
4919 of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
4921 *flags |= CLK_IS_CRITICAL;
4927 * of_clk_init() - Scan and init clock providers from the DT
4928 * @matches: array of compatible values and init functions for providers.
4930 * This function scans the device tree for matching clock providers
4931 * and calls their initialization functions. It also does it by trying
4932 * to follow the dependencies.
4934 void __init of_clk_init(const struct of_device_id *matches)
4936 const struct of_device_id *match;
4937 struct device_node *np;
4938 struct clock_provider *clk_provider, *next;
4941 LIST_HEAD(clk_provider_list);
4944 matches = &__clk_of_table;
4946 /* First prepare the list of the clocks providers */
4947 for_each_matching_node_and_match(np, matches, &match) {
4948 struct clock_provider *parent;
4950 if (!of_device_is_available(np))
4953 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
4955 list_for_each_entry_safe(clk_provider, next,
4956 &clk_provider_list, node) {
4957 list_del(&clk_provider->node);
4958 of_node_put(clk_provider->np);
4959 kfree(clk_provider);
4965 parent->clk_init_cb = match->data;
4966 parent->np = of_node_get(np);
4967 list_add_tail(&parent->node, &clk_provider_list);
4970 while (!list_empty(&clk_provider_list)) {
4971 is_init_done = false;
4972 list_for_each_entry_safe(clk_provider, next,
4973 &clk_provider_list, node) {
4974 if (force || parent_ready(clk_provider->np)) {
4976 /* Don't populate platform devices */
4977 of_node_set_flag(clk_provider->np,
4980 clk_provider->clk_init_cb(clk_provider->np);
4981 of_clk_set_defaults(clk_provider->np, true);
4983 list_del(&clk_provider->node);
4984 of_node_put(clk_provider->np);
4985 kfree(clk_provider);
4986 is_init_done = true;
4991 * We didn't manage to initialize any of the
4992 * remaining providers during the last loop, so now we
4993 * initialize all the remaining ones unconditionally
4994 * in case the clock parent was not mandatory