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;
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_hw_get_flags(const struct clk_hw *hw)
505 return hw->core->flags;
507 EXPORT_SYMBOL_GPL(clk_hw_get_flags);
509 bool clk_hw_is_prepared(const struct clk_hw *hw)
511 return clk_core_is_prepared(hw->core);
513 EXPORT_SYMBOL_GPL(clk_hw_is_prepared);
515 bool clk_hw_rate_is_protected(const struct clk_hw *hw)
517 return clk_core_rate_is_protected(hw->core);
519 EXPORT_SYMBOL_GPL(clk_hw_rate_is_protected);
521 bool clk_hw_is_enabled(const struct clk_hw *hw)
523 return clk_core_is_enabled(hw->core);
525 EXPORT_SYMBOL_GPL(clk_hw_is_enabled);
527 bool __clk_is_enabled(struct clk *clk)
532 return clk_core_is_enabled(clk->core);
534 EXPORT_SYMBOL_GPL(__clk_is_enabled);
536 static bool mux_is_better_rate(unsigned long rate, unsigned long now,
537 unsigned long best, unsigned long flags)
539 if (flags & CLK_MUX_ROUND_CLOSEST)
540 return abs(now - rate) < abs(best - rate);
542 return now <= rate && now > best;
545 int clk_mux_determine_rate_flags(struct clk_hw *hw,
546 struct clk_rate_request *req,
549 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
550 int i, num_parents, ret;
551 unsigned long best = 0;
552 struct clk_rate_request parent_req = *req;
554 /* if NO_REPARENT flag set, pass through to current parent */
555 if (core->flags & CLK_SET_RATE_NO_REPARENT) {
556 parent = core->parent;
557 if (core->flags & CLK_SET_RATE_PARENT) {
558 ret = __clk_determine_rate(parent ? parent->hw : NULL,
563 best = parent_req.rate;
565 best = clk_core_get_rate_nolock(parent);
567 best = clk_core_get_rate_nolock(core);
573 /* find the parent that can provide the fastest rate <= rate */
574 num_parents = core->num_parents;
575 for (i = 0; i < num_parents; i++) {
576 parent = clk_core_get_parent_by_index(core, i);
580 if (core->flags & CLK_SET_RATE_PARENT) {
582 ret = __clk_determine_rate(parent->hw, &parent_req);
586 parent_req.rate = clk_core_get_rate_nolock(parent);
589 if (mux_is_better_rate(req->rate, parent_req.rate,
591 best_parent = parent;
592 best = parent_req.rate;
601 req->best_parent_hw = best_parent->hw;
602 req->best_parent_rate = best;
607 EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);
609 struct clk *__clk_lookup(const char *name)
611 struct clk_core *core = clk_core_lookup(name);
613 return !core ? NULL : core->hw->clk;
616 static void clk_core_get_boundaries(struct clk_core *core,
617 unsigned long *min_rate,
618 unsigned long *max_rate)
620 struct clk *clk_user;
622 lockdep_assert_held(&prepare_lock);
624 *min_rate = core->min_rate;
625 *max_rate = core->max_rate;
627 hlist_for_each_entry(clk_user, &core->clks, clks_node)
628 *min_rate = max(*min_rate, clk_user->min_rate);
630 hlist_for_each_entry(clk_user, &core->clks, clks_node)
631 *max_rate = min(*max_rate, clk_user->max_rate);
634 void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
635 unsigned long max_rate)
637 hw->core->min_rate = min_rate;
638 hw->core->max_rate = max_rate;
640 EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
643 * __clk_mux_determine_rate - clk_ops::determine_rate implementation for a mux type clk
644 * @hw: mux type clk to determine rate on
645 * @req: rate request, also used to return preferred parent and frequencies
647 * Helper for finding best parent to provide a given frequency. This can be used
648 * directly as a determine_rate callback (e.g. for a mux), or from a more
649 * complex clock that may combine a mux with other operations.
651 * Returns: 0 on success, -EERROR value on error
653 int __clk_mux_determine_rate(struct clk_hw *hw,
654 struct clk_rate_request *req)
656 return clk_mux_determine_rate_flags(hw, req, 0);
658 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
660 int __clk_mux_determine_rate_closest(struct clk_hw *hw,
661 struct clk_rate_request *req)
663 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
665 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
669 static void clk_core_rate_unprotect(struct clk_core *core)
671 lockdep_assert_held(&prepare_lock);
676 if (WARN(core->protect_count == 0,
677 "%s already unprotected\n", core->name))
680 if (--core->protect_count > 0)
683 clk_core_rate_unprotect(core->parent);
686 static int clk_core_rate_nuke_protect(struct clk_core *core)
690 lockdep_assert_held(&prepare_lock);
695 if (core->protect_count == 0)
698 ret = core->protect_count;
699 core->protect_count = 1;
700 clk_core_rate_unprotect(core);
706 * clk_rate_exclusive_put - release exclusivity over clock rate control
707 * @clk: the clk over which the exclusivity is released
709 * clk_rate_exclusive_put() completes a critical section during which a clock
710 * consumer cannot tolerate any other consumer making any operation on the
711 * clock which could result in a rate change or rate glitch. Exclusive clocks
712 * cannot have their rate changed, either directly or indirectly due to changes
713 * further up the parent chain of clocks. As a result, clocks up parent chain
714 * also get under exclusive control of the calling consumer.
716 * If exlusivity is claimed more than once on clock, even by the same consumer,
717 * the rate effectively gets locked as exclusivity can't be preempted.
719 * Calls to clk_rate_exclusive_put() must be balanced with calls to
720 * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
723 void clk_rate_exclusive_put(struct clk *clk)
731 * if there is something wrong with this consumer protect count, stop
732 * here before messing with the provider
734 if (WARN_ON(clk->exclusive_count <= 0))
737 clk_core_rate_unprotect(clk->core);
738 clk->exclusive_count--;
740 clk_prepare_unlock();
742 EXPORT_SYMBOL_GPL(clk_rate_exclusive_put);
744 static void clk_core_rate_protect(struct clk_core *core)
746 lockdep_assert_held(&prepare_lock);
751 if (core->protect_count == 0)
752 clk_core_rate_protect(core->parent);
754 core->protect_count++;
757 static void clk_core_rate_restore_protect(struct clk_core *core, int count)
759 lockdep_assert_held(&prepare_lock);
767 clk_core_rate_protect(core);
768 core->protect_count = count;
772 * clk_rate_exclusive_get - get exclusivity over the clk rate control
773 * @clk: the clk over which the exclusity of rate control is requested
775 * clk_rate_exclusive_get() begins a critical section during which a clock
776 * consumer cannot tolerate any other consumer making any operation on the
777 * clock which could result in a rate change or rate glitch. Exclusive clocks
778 * cannot have their rate changed, either directly or indirectly due to changes
779 * further up the parent chain of clocks. As a result, clocks up parent chain
780 * also get under exclusive control of the calling consumer.
782 * If exlusivity is claimed more than once on clock, even by the same consumer,
783 * the rate effectively gets locked as exclusivity can't be preempted.
785 * Calls to clk_rate_exclusive_get() should be balanced with calls to
786 * clk_rate_exclusive_put(). Calls to this function may sleep.
787 * Returns 0 on success, -EERROR otherwise
789 int clk_rate_exclusive_get(struct clk *clk)
795 clk_core_rate_protect(clk->core);
796 clk->exclusive_count++;
797 clk_prepare_unlock();
801 EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
803 static void clk_core_unprepare(struct clk_core *core)
805 lockdep_assert_held(&prepare_lock);
810 if (WARN(core->prepare_count == 0,
811 "%s already unprepared\n", core->name))
814 if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL,
815 "Unpreparing critical %s\n", core->name))
818 if (core->flags & CLK_SET_RATE_GATE)
819 clk_core_rate_unprotect(core);
821 if (--core->prepare_count > 0)
824 WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);
826 trace_clk_unprepare(core);
828 if (core->ops->unprepare)
829 core->ops->unprepare(core->hw);
831 clk_pm_runtime_put(core);
833 trace_clk_unprepare_complete(core);
834 clk_core_unprepare(core->parent);
837 static void clk_core_unprepare_lock(struct clk_core *core)
840 clk_core_unprepare(core);
841 clk_prepare_unlock();
845 * clk_unprepare - undo preparation of a clock source
846 * @clk: the clk being unprepared
848 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
849 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
850 * if the operation may sleep. One example is a clk which is accessed over
851 * I2c. In the complex case a clk gate operation may require a fast and a slow
852 * part. It is this reason that clk_unprepare and clk_disable are not mutually
853 * exclusive. In fact clk_disable must be called before clk_unprepare.
855 void clk_unprepare(struct clk *clk)
857 if (IS_ERR_OR_NULL(clk))
860 clk_core_unprepare_lock(clk->core);
862 EXPORT_SYMBOL_GPL(clk_unprepare);
864 static int clk_core_prepare(struct clk_core *core)
868 lockdep_assert_held(&prepare_lock);
873 if (core->prepare_count == 0) {
874 ret = clk_pm_runtime_get(core);
878 ret = clk_core_prepare(core->parent);
882 trace_clk_prepare(core);
884 if (core->ops->prepare)
885 ret = core->ops->prepare(core->hw);
887 trace_clk_prepare_complete(core);
893 core->prepare_count++;
896 * CLK_SET_RATE_GATE is a special case of clock protection
897 * Instead of a consumer claiming exclusive rate control, it is
898 * actually the provider which prevents any consumer from making any
899 * operation which could result in a rate change or rate glitch while
900 * the clock is prepared.
902 if (core->flags & CLK_SET_RATE_GATE)
903 clk_core_rate_protect(core);
907 clk_core_unprepare(core->parent);
909 clk_pm_runtime_put(core);
913 static int clk_core_prepare_lock(struct clk_core *core)
918 ret = clk_core_prepare(core);
919 clk_prepare_unlock();
925 * clk_prepare - prepare a clock source
926 * @clk: the clk being prepared
928 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
929 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
930 * operation may sleep. One example is a clk which is accessed over I2c. In
931 * the complex case a clk ungate operation may require a fast and a slow part.
932 * It is this reason that clk_prepare and clk_enable are not mutually
933 * exclusive. In fact clk_prepare must be called before clk_enable.
934 * Returns 0 on success, -EERROR otherwise.
936 int clk_prepare(struct clk *clk)
941 return clk_core_prepare_lock(clk->core);
943 EXPORT_SYMBOL_GPL(clk_prepare);
945 static void clk_core_disable(struct clk_core *core)
947 lockdep_assert_held(&enable_lock);
952 if (WARN(core->enable_count == 0, "%s already disabled\n", core->name))
955 if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL,
956 "Disabling critical %s\n", core->name))
959 if (--core->enable_count > 0)
962 trace_clk_disable_rcuidle(core);
964 if (core->ops->disable)
965 core->ops->disable(core->hw);
967 trace_clk_disable_complete_rcuidle(core);
969 clk_core_disable(core->parent);
972 static void clk_core_disable_lock(struct clk_core *core)
976 flags = clk_enable_lock();
977 clk_core_disable(core);
978 clk_enable_unlock(flags);
982 * clk_disable - gate a clock
983 * @clk: the clk being gated
985 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
986 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
987 * clk if the operation is fast and will never sleep. One example is a
988 * SoC-internal clk which is controlled via simple register writes. In the
989 * complex case a clk gate operation may require a fast and a slow part. It is
990 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
991 * In fact clk_disable must be called before clk_unprepare.
993 void clk_disable(struct clk *clk)
995 if (IS_ERR_OR_NULL(clk))
998 clk_core_disable_lock(clk->core);
1000 EXPORT_SYMBOL_GPL(clk_disable);
1002 static int clk_core_enable(struct clk_core *core)
1006 lockdep_assert_held(&enable_lock);
1011 if (WARN(core->prepare_count == 0,
1012 "Enabling unprepared %s\n", core->name))
1015 if (core->enable_count == 0) {
1016 ret = clk_core_enable(core->parent);
1021 trace_clk_enable_rcuidle(core);
1023 if (core->ops->enable)
1024 ret = core->ops->enable(core->hw);
1026 trace_clk_enable_complete_rcuidle(core);
1029 clk_core_disable(core->parent);
1034 core->enable_count++;
1038 static int clk_core_enable_lock(struct clk_core *core)
1040 unsigned long flags;
1043 flags = clk_enable_lock();
1044 ret = clk_core_enable(core);
1045 clk_enable_unlock(flags);
1051 * clk_gate_restore_context - restore context for poweroff
1052 * @hw: the clk_hw pointer of clock whose state is to be restored
1054 * The clock gate restore context function enables or disables
1055 * the gate clocks based on the enable_count. This is done in cases
1056 * where the clock context is lost and based on the enable_count
1057 * the clock either needs to be enabled/disabled. This
1058 * helps restore the state of gate clocks.
1060 void clk_gate_restore_context(struct clk_hw *hw)
1062 struct clk_core *core = hw->core;
1064 if (core->enable_count)
1065 core->ops->enable(hw);
1067 core->ops->disable(hw);
1069 EXPORT_SYMBOL_GPL(clk_gate_restore_context);
1071 static int clk_core_save_context(struct clk_core *core)
1073 struct clk_core *child;
1076 hlist_for_each_entry(child, &core->children, child_node) {
1077 ret = clk_core_save_context(child);
1082 if (core->ops && core->ops->save_context)
1083 ret = core->ops->save_context(core->hw);
1088 static void clk_core_restore_context(struct clk_core *core)
1090 struct clk_core *child;
1092 if (core->ops && core->ops->restore_context)
1093 core->ops->restore_context(core->hw);
1095 hlist_for_each_entry(child, &core->children, child_node)
1096 clk_core_restore_context(child);
1100 * clk_save_context - save clock context for poweroff
1102 * Saves the context of the clock register for powerstates in which the
1103 * contents of the registers will be lost. Occurs deep within the suspend
1104 * code. Returns 0 on success.
1106 int clk_save_context(void)
1108 struct clk_core *clk;
1111 hlist_for_each_entry(clk, &clk_root_list, child_node) {
1112 ret = clk_core_save_context(clk);
1117 hlist_for_each_entry(clk, &clk_orphan_list, child_node) {
1118 ret = clk_core_save_context(clk);
1125 EXPORT_SYMBOL_GPL(clk_save_context);
1128 * clk_restore_context - restore clock context after poweroff
1130 * Restore the saved clock context upon resume.
1133 void clk_restore_context(void)
1135 struct clk_core *core;
1137 hlist_for_each_entry(core, &clk_root_list, child_node)
1138 clk_core_restore_context(core);
1140 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1141 clk_core_restore_context(core);
1143 EXPORT_SYMBOL_GPL(clk_restore_context);
1146 * clk_enable - ungate a clock
1147 * @clk: the clk being ungated
1149 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
1150 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
1151 * if the operation will never sleep. One example is a SoC-internal clk which
1152 * is controlled via simple register writes. In the complex case a clk ungate
1153 * operation may require a fast and a slow part. It is this reason that
1154 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
1155 * must be called before clk_enable. Returns 0 on success, -EERROR
1158 int clk_enable(struct clk *clk)
1163 return clk_core_enable_lock(clk->core);
1165 EXPORT_SYMBOL_GPL(clk_enable);
1168 * clk_is_enabled_when_prepared - indicate if preparing a clock also enables it.
1169 * @clk: clock source
1171 * Returns true if clk_prepare() implicitly enables the clock, effectively
1172 * making clk_enable()/clk_disable() no-ops, false otherwise.
1174 * This is of interest mainly to power management code where actually
1175 * disabling the clock also requires unpreparing it to have any material
1178 * Regardless of the value returned here, the caller must always invoke
1179 * clk_enable() or clk_prepare_enable() and counterparts for usage counts
1182 bool clk_is_enabled_when_prepared(struct clk *clk)
1184 return clk && !(clk->core->ops->enable && clk->core->ops->disable);
1186 EXPORT_SYMBOL_GPL(clk_is_enabled_when_prepared);
1188 static int clk_core_prepare_enable(struct clk_core *core)
1192 ret = clk_core_prepare_lock(core);
1196 ret = clk_core_enable_lock(core);
1198 clk_core_unprepare_lock(core);
1203 static void clk_core_disable_unprepare(struct clk_core *core)
1205 clk_core_disable_lock(core);
1206 clk_core_unprepare_lock(core);
1209 static void __init clk_unprepare_unused_subtree(struct clk_core *core)
1211 struct clk_core *child;
1213 lockdep_assert_held(&prepare_lock);
1215 hlist_for_each_entry(child, &core->children, child_node)
1216 clk_unprepare_unused_subtree(child);
1218 if (core->prepare_count)
1221 if (core->flags & CLK_IGNORE_UNUSED)
1224 if (clk_pm_runtime_get(core))
1227 if (clk_core_is_prepared(core)) {
1228 trace_clk_unprepare(core);
1229 if (core->ops->unprepare_unused)
1230 core->ops->unprepare_unused(core->hw);
1231 else if (core->ops->unprepare)
1232 core->ops->unprepare(core->hw);
1233 trace_clk_unprepare_complete(core);
1236 clk_pm_runtime_put(core);
1239 static void __init clk_disable_unused_subtree(struct clk_core *core)
1241 struct clk_core *child;
1242 unsigned long flags;
1244 lockdep_assert_held(&prepare_lock);
1246 hlist_for_each_entry(child, &core->children, child_node)
1247 clk_disable_unused_subtree(child);
1249 if (core->flags & CLK_OPS_PARENT_ENABLE)
1250 clk_core_prepare_enable(core->parent);
1252 if (clk_pm_runtime_get(core))
1255 flags = clk_enable_lock();
1257 if (core->enable_count)
1260 if (core->flags & CLK_IGNORE_UNUSED)
1264 * some gate clocks have special needs during the disable-unused
1265 * sequence. call .disable_unused if available, otherwise fall
1268 if (clk_core_is_enabled(core)) {
1269 trace_clk_disable(core);
1270 if (core->ops->disable_unused)
1271 core->ops->disable_unused(core->hw);
1272 else if (core->ops->disable)
1273 core->ops->disable(core->hw);
1274 trace_clk_disable_complete(core);
1278 clk_enable_unlock(flags);
1279 clk_pm_runtime_put(core);
1281 if (core->flags & CLK_OPS_PARENT_ENABLE)
1282 clk_core_disable_unprepare(core->parent);
1285 static bool clk_ignore_unused __initdata;
1286 static int __init clk_ignore_unused_setup(char *__unused)
1288 clk_ignore_unused = true;
1291 __setup("clk_ignore_unused", clk_ignore_unused_setup);
1293 static int __init clk_disable_unused(void)
1295 struct clk_core *core;
1297 if (clk_ignore_unused) {
1298 pr_warn("clk: Not disabling unused clocks\n");
1304 hlist_for_each_entry(core, &clk_root_list, child_node)
1305 clk_disable_unused_subtree(core);
1307 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1308 clk_disable_unused_subtree(core);
1310 hlist_for_each_entry(core, &clk_root_list, child_node)
1311 clk_unprepare_unused_subtree(core);
1313 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1314 clk_unprepare_unused_subtree(core);
1316 clk_prepare_unlock();
1320 late_initcall_sync(clk_disable_unused);
1322 static int clk_core_determine_round_nolock(struct clk_core *core,
1323 struct clk_rate_request *req)
1327 lockdep_assert_held(&prepare_lock);
1333 * At this point, core protection will be disabled
1334 * - if the provider is not protected at all
1335 * - if the calling consumer is the only one which has exclusivity
1338 if (clk_core_rate_is_protected(core)) {
1339 req->rate = core->rate;
1340 } else if (core->ops->determine_rate) {
1341 return core->ops->determine_rate(core->hw, req);
1342 } else if (core->ops->round_rate) {
1343 rate = core->ops->round_rate(core->hw, req->rate,
1344 &req->best_parent_rate);
1356 static void clk_core_init_rate_req(struct clk_core * const core,
1357 struct clk_rate_request *req)
1359 struct clk_core *parent;
1361 if (WARN_ON(!core || !req))
1364 parent = core->parent;
1366 req->best_parent_hw = parent->hw;
1367 req->best_parent_rate = parent->rate;
1369 req->best_parent_hw = NULL;
1370 req->best_parent_rate = 0;
1374 static bool clk_core_can_round(struct clk_core * const core)
1376 return core->ops->determine_rate || core->ops->round_rate;
1379 static int clk_core_round_rate_nolock(struct clk_core *core,
1380 struct clk_rate_request *req)
1382 lockdep_assert_held(&prepare_lock);
1389 clk_core_init_rate_req(core, req);
1391 if (clk_core_can_round(core))
1392 return clk_core_determine_round_nolock(core, req);
1393 else if (core->flags & CLK_SET_RATE_PARENT)
1394 return clk_core_round_rate_nolock(core->parent, req);
1396 req->rate = core->rate;
1401 * __clk_determine_rate - get the closest rate actually supported by a clock
1402 * @hw: determine the rate of this clock
1403 * @req: target rate request
1405 * Useful for clk_ops such as .set_rate and .determine_rate.
1407 int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
1414 return clk_core_round_rate_nolock(hw->core, req);
1416 EXPORT_SYMBOL_GPL(__clk_determine_rate);
1419 * clk_hw_round_rate() - round the given rate for a hw clk
1420 * @hw: the hw clk for which we are rounding a rate
1421 * @rate: the rate which is to be rounded
1423 * Takes in a rate as input and rounds it to a rate that the clk can actually
1426 * Context: prepare_lock must be held.
1427 * For clk providers to call from within clk_ops such as .round_rate,
1430 * Return: returns rounded rate of hw clk if clk supports round_rate operation
1431 * else returns the parent rate.
1433 unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
1436 struct clk_rate_request req;
1438 clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate);
1441 ret = clk_core_round_rate_nolock(hw->core, &req);
1447 EXPORT_SYMBOL_GPL(clk_hw_round_rate);
1450 * clk_round_rate - round the given rate for a clk
1451 * @clk: the clk for which we are rounding a rate
1452 * @rate: the rate which is to be rounded
1454 * Takes in a rate as input and rounds it to a rate that the clk can actually
1455 * use which is then returned. If clk doesn't support round_rate operation
1456 * then the parent rate is returned.
1458 long clk_round_rate(struct clk *clk, unsigned long rate)
1460 struct clk_rate_request req;
1468 if (clk->exclusive_count)
1469 clk_core_rate_unprotect(clk->core);
1471 clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
1474 ret = clk_core_round_rate_nolock(clk->core, &req);
1476 if (clk->exclusive_count)
1477 clk_core_rate_protect(clk->core);
1479 clk_prepare_unlock();
1486 EXPORT_SYMBOL_GPL(clk_round_rate);
1489 * __clk_notify - call clk notifier chain
1490 * @core: clk that is changing rate
1491 * @msg: clk notifier type (see include/linux/clk.h)
1492 * @old_rate: old clk rate
1493 * @new_rate: new clk rate
1495 * Triggers a notifier call chain on the clk rate-change notification
1496 * for 'clk'. Passes a pointer to the struct clk and the previous
1497 * and current rates to the notifier callback. Intended to be called by
1498 * internal clock code only. Returns NOTIFY_DONE from the last driver
1499 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1500 * a driver returns that.
1502 static int __clk_notify(struct clk_core *core, unsigned long msg,
1503 unsigned long old_rate, unsigned long new_rate)
1505 struct clk_notifier *cn;
1506 struct clk_notifier_data cnd;
1507 int ret = NOTIFY_DONE;
1509 cnd.old_rate = old_rate;
1510 cnd.new_rate = new_rate;
1512 list_for_each_entry(cn, &clk_notifier_list, node) {
1513 if (cn->clk->core == core) {
1515 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
1517 if (ret & NOTIFY_STOP_MASK)
1526 * __clk_recalc_accuracies
1527 * @core: first clk in the subtree
1529 * Walks the subtree of clks starting with clk and recalculates accuracies as
1530 * it goes. Note that if a clk does not implement the .recalc_accuracy
1531 * callback then it is assumed that the clock will take on the accuracy of its
1534 static void __clk_recalc_accuracies(struct clk_core *core)
1536 unsigned long parent_accuracy = 0;
1537 struct clk_core *child;
1539 lockdep_assert_held(&prepare_lock);
1542 parent_accuracy = core->parent->accuracy;
1544 if (core->ops->recalc_accuracy)
1545 core->accuracy = core->ops->recalc_accuracy(core->hw,
1548 core->accuracy = parent_accuracy;
1550 hlist_for_each_entry(child, &core->children, child_node)
1551 __clk_recalc_accuracies(child);
1554 static long clk_core_get_accuracy_recalc(struct clk_core *core)
1556 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
1557 __clk_recalc_accuracies(core);
1559 return clk_core_get_accuracy_no_lock(core);
1563 * clk_get_accuracy - return the accuracy of clk
1564 * @clk: the clk whose accuracy is being returned
1566 * Simply returns the cached accuracy of the clk, unless
1567 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1569 * If clk is NULL then returns 0.
1571 long clk_get_accuracy(struct clk *clk)
1579 accuracy = clk_core_get_accuracy_recalc(clk->core);
1580 clk_prepare_unlock();
1584 EXPORT_SYMBOL_GPL(clk_get_accuracy);
1586 static unsigned long clk_recalc(struct clk_core *core,
1587 unsigned long parent_rate)
1589 unsigned long rate = parent_rate;
1591 if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
1592 rate = core->ops->recalc_rate(core->hw, parent_rate);
1593 clk_pm_runtime_put(core);
1599 * __clk_recalc_rates
1600 * @core: first clk in the subtree
1601 * @msg: notification type (see include/linux/clk.h)
1603 * Walks the subtree of clks starting with clk and recalculates rates as it
1604 * goes. Note that if a clk does not implement the .recalc_rate callback then
1605 * it is assumed that the clock will take on the rate of its parent.
1607 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1610 static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
1612 unsigned long old_rate;
1613 unsigned long parent_rate = 0;
1614 struct clk_core *child;
1616 lockdep_assert_held(&prepare_lock);
1618 old_rate = core->rate;
1621 parent_rate = core->parent->rate;
1623 core->rate = clk_recalc(core, parent_rate);
1626 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1627 * & ABORT_RATE_CHANGE notifiers
1629 if (core->notifier_count && msg)
1630 __clk_notify(core, msg, old_rate, core->rate);
1632 hlist_for_each_entry(child, &core->children, child_node)
1633 __clk_recalc_rates(child, msg);
1636 static unsigned long clk_core_get_rate_recalc(struct clk_core *core)
1638 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1639 __clk_recalc_rates(core, 0);
1641 return clk_core_get_rate_nolock(core);
1645 * clk_get_rate - return the rate of clk
1646 * @clk: the clk whose rate is being returned
1648 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1649 * is set, which means a recalc_rate will be issued.
1650 * If clk is NULL then returns 0.
1652 unsigned long clk_get_rate(struct clk *clk)
1660 rate = clk_core_get_rate_recalc(clk->core);
1661 clk_prepare_unlock();
1665 EXPORT_SYMBOL_GPL(clk_get_rate);
1667 static int clk_fetch_parent_index(struct clk_core *core,
1668 struct clk_core *parent)
1675 for (i = 0; i < core->num_parents; i++) {
1676 /* Found it first try! */
1677 if (core->parents[i].core == parent)
1680 /* Something else is here, so keep looking */
1681 if (core->parents[i].core)
1684 /* Maybe core hasn't been cached but the hw is all we know? */
1685 if (core->parents[i].hw) {
1686 if (core->parents[i].hw == parent->hw)
1689 /* Didn't match, but we're expecting a clk_hw */
1693 /* Maybe it hasn't been cached (clk_set_parent() path) */
1694 if (parent == clk_core_get(core, i))
1697 /* Fallback to comparing globally unique names */
1698 if (core->parents[i].name &&
1699 !strcmp(parent->name, core->parents[i].name))
1703 if (i == core->num_parents)
1706 core->parents[i].core = parent;
1711 * clk_hw_get_parent_index - return the index of the parent clock
1712 * @hw: clk_hw associated with the clk being consumed
1714 * Fetches and returns the index of parent clock. Returns -EINVAL if the given
1715 * clock does not have a current parent.
1717 int clk_hw_get_parent_index(struct clk_hw *hw)
1719 struct clk_hw *parent = clk_hw_get_parent(hw);
1721 if (WARN_ON(parent == NULL))
1724 return clk_fetch_parent_index(hw->core, parent->core);
1726 EXPORT_SYMBOL_GPL(clk_hw_get_parent_index);
1729 * Update the orphan status of @core and all its children.
1731 static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
1733 struct clk_core *child;
1735 core->orphan = is_orphan;
1737 hlist_for_each_entry(child, &core->children, child_node)
1738 clk_core_update_orphan_status(child, is_orphan);
1741 static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1743 bool was_orphan = core->orphan;
1745 hlist_del(&core->child_node);
1748 bool becomes_orphan = new_parent->orphan;
1750 /* avoid duplicate POST_RATE_CHANGE notifications */
1751 if (new_parent->new_child == core)
1752 new_parent->new_child = NULL;
1754 hlist_add_head(&core->child_node, &new_parent->children);
1756 if (was_orphan != becomes_orphan)
1757 clk_core_update_orphan_status(core, becomes_orphan);
1759 hlist_add_head(&core->child_node, &clk_orphan_list);
1761 clk_core_update_orphan_status(core, true);
1764 core->parent = new_parent;
1767 static struct clk_core *__clk_set_parent_before(struct clk_core *core,
1768 struct clk_core *parent)
1770 unsigned long flags;
1771 struct clk_core *old_parent = core->parent;
1774 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
1776 * 2. Migrate prepare state between parents and prevent race with
1779 * If the clock is not prepared, then a race with
1780 * clk_enable/disable() is impossible since we already have the
1781 * prepare lock (future calls to clk_enable() need to be preceded by
1784 * If the clock is prepared, migrate the prepared state to the new
1785 * parent and also protect against a race with clk_enable() by
1786 * forcing the clock and the new parent on. This ensures that all
1787 * future calls to clk_enable() are practically NOPs with respect to
1788 * hardware and software states.
1790 * See also: Comment for clk_set_parent() below.
1793 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
1794 if (core->flags & CLK_OPS_PARENT_ENABLE) {
1795 clk_core_prepare_enable(old_parent);
1796 clk_core_prepare_enable(parent);
1799 /* migrate prepare count if > 0 */
1800 if (core->prepare_count) {
1801 clk_core_prepare_enable(parent);
1802 clk_core_enable_lock(core);
1805 /* update the clk tree topology */
1806 flags = clk_enable_lock();
1807 clk_reparent(core, parent);
1808 clk_enable_unlock(flags);
1813 static void __clk_set_parent_after(struct clk_core *core,
1814 struct clk_core *parent,
1815 struct clk_core *old_parent)
1818 * Finish the migration of prepare state and undo the changes done
1819 * for preventing a race with clk_enable().
1821 if (core->prepare_count) {
1822 clk_core_disable_lock(core);
1823 clk_core_disable_unprepare(old_parent);
1826 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
1827 if (core->flags & CLK_OPS_PARENT_ENABLE) {
1828 clk_core_disable_unprepare(parent);
1829 clk_core_disable_unprepare(old_parent);
1833 static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
1836 unsigned long flags;
1838 struct clk_core *old_parent;
1840 old_parent = __clk_set_parent_before(core, parent);
1842 trace_clk_set_parent(core, parent);
1844 /* change clock input source */
1845 if (parent && core->ops->set_parent)
1846 ret = core->ops->set_parent(core->hw, p_index);
1848 trace_clk_set_parent_complete(core, parent);
1851 flags = clk_enable_lock();
1852 clk_reparent(core, old_parent);
1853 clk_enable_unlock(flags);
1854 __clk_set_parent_after(core, old_parent, parent);
1859 __clk_set_parent_after(core, parent, old_parent);
1865 * __clk_speculate_rates
1866 * @core: first clk in the subtree
1867 * @parent_rate: the "future" rate of clk's parent
1869 * Walks the subtree of clks starting with clk, speculating rates as it
1870 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1872 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1873 * pre-rate change notifications and returns early if no clks in the
1874 * subtree have subscribed to the notifications. Note that if a clk does not
1875 * implement the .recalc_rate callback then it is assumed that the clock will
1876 * take on the rate of its parent.
1878 static int __clk_speculate_rates(struct clk_core *core,
1879 unsigned long parent_rate)
1881 struct clk_core *child;
1882 unsigned long new_rate;
1883 int ret = NOTIFY_DONE;
1885 lockdep_assert_held(&prepare_lock);
1887 new_rate = clk_recalc(core, parent_rate);
1889 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1890 if (core->notifier_count)
1891 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
1893 if (ret & NOTIFY_STOP_MASK) {
1894 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1895 __func__, core->name, ret);
1899 hlist_for_each_entry(child, &core->children, child_node) {
1900 ret = __clk_speculate_rates(child, new_rate);
1901 if (ret & NOTIFY_STOP_MASK)
1909 static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
1910 struct clk_core *new_parent, u8 p_index)
1912 struct clk_core *child;
1914 core->new_rate = new_rate;
1915 core->new_parent = new_parent;
1916 core->new_parent_index = p_index;
1917 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1918 core->new_child = NULL;
1919 if (new_parent && new_parent != core->parent)
1920 new_parent->new_child = core;
1922 hlist_for_each_entry(child, &core->children, child_node) {
1923 child->new_rate = clk_recalc(child, new_rate);
1924 clk_calc_subtree(child, child->new_rate, NULL, 0);
1929 * calculate the new rates returning the topmost clock that has to be
1932 static struct clk_core *clk_calc_new_rates(struct clk_core *core,
1935 struct clk_core *top = core;
1936 struct clk_core *old_parent, *parent;
1937 unsigned long best_parent_rate = 0;
1938 unsigned long new_rate;
1939 unsigned long min_rate;
1940 unsigned long max_rate;
1945 if (IS_ERR_OR_NULL(core))
1948 /* save parent rate, if it exists */
1949 parent = old_parent = core->parent;
1951 best_parent_rate = parent->rate;
1953 clk_core_get_boundaries(core, &min_rate, &max_rate);
1955 /* find the closest rate and parent clk/rate */
1956 if (clk_core_can_round(core)) {
1957 struct clk_rate_request req;
1960 req.min_rate = min_rate;
1961 req.max_rate = max_rate;
1963 clk_core_init_rate_req(core, &req);
1965 ret = clk_core_determine_round_nolock(core, &req);
1969 best_parent_rate = req.best_parent_rate;
1970 new_rate = req.rate;
1971 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
1973 if (new_rate < min_rate || new_rate > max_rate)
1975 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
1976 /* pass-through clock without adjustable parent */
1977 core->new_rate = core->rate;
1980 /* pass-through clock with adjustable parent */
1981 top = clk_calc_new_rates(parent, rate);
1982 new_rate = parent->new_rate;
1986 /* some clocks must be gated to change parent */
1987 if (parent != old_parent &&
1988 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1989 pr_debug("%s: %s not gated but wants to reparent\n",
1990 __func__, core->name);
1994 /* try finding the new parent index */
1995 if (parent && core->num_parents > 1) {
1996 p_index = clk_fetch_parent_index(core, parent);
1998 pr_debug("%s: clk %s can not be parent of clk %s\n",
1999 __func__, parent->name, core->name);
2004 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
2005 best_parent_rate != parent->rate)
2006 top = clk_calc_new_rates(parent, best_parent_rate);
2009 clk_calc_subtree(core, new_rate, parent, p_index);
2015 * Notify about rate changes in a subtree. Always walk down the whole tree
2016 * so that in case of an error we can walk down the whole tree again and
2019 static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
2020 unsigned long event)
2022 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
2023 int ret = NOTIFY_DONE;
2025 if (core->rate == core->new_rate)
2028 if (core->notifier_count) {
2029 ret = __clk_notify(core, event, core->rate, core->new_rate);
2030 if (ret & NOTIFY_STOP_MASK)
2034 hlist_for_each_entry(child, &core->children, child_node) {
2035 /* Skip children who will be reparented to another clock */
2036 if (child->new_parent && child->new_parent != core)
2038 tmp_clk = clk_propagate_rate_change(child, event);
2043 /* handle the new child who might not be in core->children yet */
2044 if (core->new_child) {
2045 tmp_clk = clk_propagate_rate_change(core->new_child, event);
2054 * walk down a subtree and set the new rates notifying the rate
2057 static void clk_change_rate(struct clk_core *core)
2059 struct clk_core *child;
2060 struct hlist_node *tmp;
2061 unsigned long old_rate;
2062 unsigned long best_parent_rate = 0;
2063 bool skip_set_rate = false;
2064 struct clk_core *old_parent;
2065 struct clk_core *parent = NULL;
2067 old_rate = core->rate;
2069 if (core->new_parent) {
2070 parent = core->new_parent;
2071 best_parent_rate = core->new_parent->rate;
2072 } else if (core->parent) {
2073 parent = core->parent;
2074 best_parent_rate = core->parent->rate;
2077 if (clk_pm_runtime_get(core))
2080 if (core->flags & CLK_SET_RATE_UNGATE) {
2081 clk_core_prepare(core);
2082 clk_core_enable_lock(core);
2085 if (core->new_parent && core->new_parent != core->parent) {
2086 old_parent = __clk_set_parent_before(core, core->new_parent);
2087 trace_clk_set_parent(core, core->new_parent);
2089 if (core->ops->set_rate_and_parent) {
2090 skip_set_rate = true;
2091 core->ops->set_rate_and_parent(core->hw, core->new_rate,
2093 core->new_parent_index);
2094 } else if (core->ops->set_parent) {
2095 core->ops->set_parent(core->hw, core->new_parent_index);
2098 trace_clk_set_parent_complete(core, core->new_parent);
2099 __clk_set_parent_after(core, core->new_parent, old_parent);
2102 if (core->flags & CLK_OPS_PARENT_ENABLE)
2103 clk_core_prepare_enable(parent);
2105 trace_clk_set_rate(core, core->new_rate);
2107 if (!skip_set_rate && core->ops->set_rate)
2108 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
2110 trace_clk_set_rate_complete(core, core->new_rate);
2112 core->rate = clk_recalc(core, best_parent_rate);
2114 if (core->flags & CLK_SET_RATE_UNGATE) {
2115 clk_core_disable_lock(core);
2116 clk_core_unprepare(core);
2119 if (core->flags & CLK_OPS_PARENT_ENABLE)
2120 clk_core_disable_unprepare(parent);
2122 if (core->notifier_count && old_rate != core->rate)
2123 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
2125 if (core->flags & CLK_RECALC_NEW_RATES)
2126 (void)clk_calc_new_rates(core, core->new_rate);
2129 * Use safe iteration, as change_rate can actually swap parents
2130 * for certain clock types.
2132 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
2133 /* Skip children who will be reparented to another clock */
2134 if (child->new_parent && child->new_parent != core)
2136 clk_change_rate(child);
2139 /* handle the new child who might not be in core->children yet */
2140 if (core->new_child)
2141 clk_change_rate(core->new_child);
2143 clk_pm_runtime_put(core);
2146 static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
2147 unsigned long req_rate)
2150 struct clk_rate_request req;
2152 lockdep_assert_held(&prepare_lock);
2157 /* simulate what the rate would be if it could be freely set */
2158 cnt = clk_core_rate_nuke_protect(core);
2162 clk_core_get_boundaries(core, &req.min_rate, &req.max_rate);
2163 req.rate = req_rate;
2165 ret = clk_core_round_rate_nolock(core, &req);
2167 /* restore the protection */
2168 clk_core_rate_restore_protect(core, cnt);
2170 return ret ? 0 : req.rate;
2173 static int clk_core_set_rate_nolock(struct clk_core *core,
2174 unsigned long req_rate)
2176 struct clk_core *top, *fail_clk;
2183 rate = clk_core_req_round_rate_nolock(core, req_rate);
2185 /* bail early if nothing to do */
2186 if (rate == clk_core_get_rate_nolock(core))
2189 /* fail on a direct rate set of a protected provider */
2190 if (clk_core_rate_is_protected(core))
2193 /* calculate new rates and get the topmost changed clock */
2194 top = clk_calc_new_rates(core, req_rate);
2198 ret = clk_pm_runtime_get(core);
2202 /* notify that we are about to change rates */
2203 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
2205 pr_debug("%s: failed to set %s rate\n", __func__,
2207 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
2212 /* change the rates */
2213 clk_change_rate(top);
2215 core->req_rate = req_rate;
2217 clk_pm_runtime_put(core);
2223 * clk_set_rate - specify a new rate for clk
2224 * @clk: the clk whose rate is being changed
2225 * @rate: the new rate for clk
2227 * In the simplest case clk_set_rate will only adjust the rate of clk.
2229 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
2230 * propagate up to clk's parent; whether or not this happens depends on the
2231 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
2232 * after calling .round_rate then upstream parent propagation is ignored. If
2233 * *parent_rate comes back with a new rate for clk's parent then we propagate
2234 * up to clk's parent and set its rate. Upward propagation will continue
2235 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
2236 * .round_rate stops requesting changes to clk's parent_rate.
2238 * Rate changes are accomplished via tree traversal that also recalculates the
2239 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
2241 * Returns 0 on success, -EERROR otherwise.
2243 int clk_set_rate(struct clk *clk, unsigned long rate)
2250 /* prevent racing with updates to the clock topology */
2253 if (clk->exclusive_count)
2254 clk_core_rate_unprotect(clk->core);
2256 ret = clk_core_set_rate_nolock(clk->core, rate);
2258 if (clk->exclusive_count)
2259 clk_core_rate_protect(clk->core);
2261 clk_prepare_unlock();
2265 EXPORT_SYMBOL_GPL(clk_set_rate);
2268 * clk_set_rate_exclusive - specify a new rate and get exclusive control
2269 * @clk: the clk whose rate is being changed
2270 * @rate: the new rate for clk
2272 * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
2273 * within a critical section
2275 * This can be used initially to ensure that at least 1 consumer is
2276 * satisfied when several consumers are competing for exclusivity over the
2277 * same clock provider.
2279 * The exclusivity is not applied if setting the rate failed.
2281 * Calls to clk_rate_exclusive_get() should be balanced with calls to
2282 * clk_rate_exclusive_put().
2284 * Returns 0 on success, -EERROR otherwise.
2286 int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
2293 /* prevent racing with updates to the clock topology */
2297 * The temporary protection removal is not here, on purpose
2298 * This function is meant to be used instead of clk_rate_protect,
2299 * so before the consumer code path protect the clock provider
2302 ret = clk_core_set_rate_nolock(clk->core, rate);
2304 clk_core_rate_protect(clk->core);
2305 clk->exclusive_count++;
2308 clk_prepare_unlock();
2312 EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
2315 * clk_set_rate_range - set a rate range for a clock source
2316 * @clk: clock source
2317 * @min: desired minimum clock rate in Hz, inclusive
2318 * @max: desired maximum clock rate in Hz, inclusive
2320 * Returns success (0) or negative errno.
2322 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
2325 unsigned long old_min, old_max, rate;
2330 trace_clk_set_rate_range(clk->core, min, max);
2333 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
2334 __func__, clk->core->name, clk->dev_id, clk->con_id,
2341 if (clk->exclusive_count)
2342 clk_core_rate_unprotect(clk->core);
2344 /* Save the current values in case we need to rollback the change */
2345 old_min = clk->min_rate;
2346 old_max = clk->max_rate;
2347 clk->min_rate = min;
2348 clk->max_rate = max;
2350 rate = clk_core_get_rate_nolock(clk->core);
2351 if (rate < min || rate > max) {
2354 * We are in bit of trouble here, current rate is outside the
2355 * the requested range. We are going try to request appropriate
2356 * range boundary but there is a catch. It may fail for the
2357 * usual reason (clock broken, clock protected, etc) but also
2359 * - round_rate() was not favorable and fell on the wrong
2360 * side of the boundary
2361 * - the determine_rate() callback does not really check for
2362 * this corner case when determining the rate
2370 ret = clk_core_set_rate_nolock(clk->core, rate);
2372 /* rollback the changes */
2373 clk->min_rate = old_min;
2374 clk->max_rate = old_max;
2378 if (clk->exclusive_count)
2379 clk_core_rate_protect(clk->core);
2381 clk_prepare_unlock();
2385 EXPORT_SYMBOL_GPL(clk_set_rate_range);
2388 * clk_set_min_rate - set a minimum clock rate for a clock source
2389 * @clk: clock source
2390 * @rate: desired minimum clock rate in Hz, inclusive
2392 * Returns success (0) or negative errno.
2394 int clk_set_min_rate(struct clk *clk, unsigned long rate)
2399 trace_clk_set_min_rate(clk->core, rate);
2401 return clk_set_rate_range(clk, rate, clk->max_rate);
2403 EXPORT_SYMBOL_GPL(clk_set_min_rate);
2406 * clk_set_max_rate - set a maximum clock rate for a clock source
2407 * @clk: clock source
2408 * @rate: desired maximum clock rate in Hz, inclusive
2410 * Returns success (0) or negative errno.
2412 int clk_set_max_rate(struct clk *clk, unsigned long rate)
2417 trace_clk_set_max_rate(clk->core, rate);
2419 return clk_set_rate_range(clk, clk->min_rate, rate);
2421 EXPORT_SYMBOL_GPL(clk_set_max_rate);
2424 * clk_get_parent - return the parent of a clk
2425 * @clk: the clk whose parent gets returned
2427 * Simply returns clk->parent. Returns NULL if clk is NULL.
2429 struct clk *clk_get_parent(struct clk *clk)
2437 /* TODO: Create a per-user clk and change callers to call clk_put */
2438 parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
2439 clk_prepare_unlock();
2443 EXPORT_SYMBOL_GPL(clk_get_parent);
2445 static struct clk_core *__clk_init_parent(struct clk_core *core)
2449 if (core->num_parents > 1 && core->ops->get_parent)
2450 index = core->ops->get_parent(core->hw);
2452 return clk_core_get_parent_by_index(core, index);
2455 static void clk_core_reparent(struct clk_core *core,
2456 struct clk_core *new_parent)
2458 clk_reparent(core, new_parent);
2459 __clk_recalc_accuracies(core);
2460 __clk_recalc_rates(core, POST_RATE_CHANGE);
2463 void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
2468 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
2472 * clk_has_parent - check if a clock is a possible parent for another
2473 * @clk: clock source
2474 * @parent: parent clock source
2476 * This function can be used in drivers that need to check that a clock can be
2477 * the parent of another without actually changing the parent.
2479 * Returns true if @parent is a possible parent for @clk, false otherwise.
2481 bool clk_has_parent(struct clk *clk, struct clk *parent)
2483 struct clk_core *core, *parent_core;
2486 /* NULL clocks should be nops, so return success if either is NULL. */
2487 if (!clk || !parent)
2491 parent_core = parent->core;
2493 /* Optimize for the case where the parent is already the parent. */
2494 if (core->parent == parent_core)
2497 for (i = 0; i < core->num_parents; i++)
2498 if (!strcmp(core->parents[i].name, parent_core->name))
2503 EXPORT_SYMBOL_GPL(clk_has_parent);
2505 static int clk_core_set_parent_nolock(struct clk_core *core,
2506 struct clk_core *parent)
2510 unsigned long p_rate = 0;
2512 lockdep_assert_held(&prepare_lock);
2517 if (core->parent == parent)
2520 /* verify ops for multi-parent clks */
2521 if (core->num_parents > 1 && !core->ops->set_parent)
2524 /* check that we are allowed to re-parent if the clock is in use */
2525 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
2528 if (clk_core_rate_is_protected(core))
2531 /* try finding the new parent index */
2533 p_index = clk_fetch_parent_index(core, parent);
2535 pr_debug("%s: clk %s can not be parent of clk %s\n",
2536 __func__, parent->name, core->name);
2539 p_rate = parent->rate;
2542 ret = clk_pm_runtime_get(core);
2546 /* propagate PRE_RATE_CHANGE notifications */
2547 ret = __clk_speculate_rates(core, p_rate);
2549 /* abort if a driver objects */
2550 if (ret & NOTIFY_STOP_MASK)
2553 /* do the re-parent */
2554 ret = __clk_set_parent(core, parent, p_index);
2556 /* propagate rate an accuracy recalculation accordingly */
2558 __clk_recalc_rates(core, ABORT_RATE_CHANGE);
2560 __clk_recalc_rates(core, POST_RATE_CHANGE);
2561 __clk_recalc_accuracies(core);
2565 clk_pm_runtime_put(core);
2570 int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *parent)
2572 return clk_core_set_parent_nolock(hw->core, parent->core);
2574 EXPORT_SYMBOL_GPL(clk_hw_set_parent);
2577 * clk_set_parent - switch the parent of a mux clk
2578 * @clk: the mux clk whose input we are switching
2579 * @parent: the new input to clk
2581 * Re-parent clk to use parent as its new input source. If clk is in
2582 * prepared state, the clk will get enabled for the duration of this call. If
2583 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2584 * that, the reparenting is glitchy in hardware, etc), use the
2585 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2587 * After successfully changing clk's parent clk_set_parent will update the
2588 * clk topology, sysfs topology and propagate rate recalculation via
2589 * __clk_recalc_rates.
2591 * Returns 0 on success, -EERROR otherwise.
2593 int clk_set_parent(struct clk *clk, struct clk *parent)
2602 if (clk->exclusive_count)
2603 clk_core_rate_unprotect(clk->core);
2605 ret = clk_core_set_parent_nolock(clk->core,
2606 parent ? parent->core : NULL);
2608 if (clk->exclusive_count)
2609 clk_core_rate_protect(clk->core);
2611 clk_prepare_unlock();
2615 EXPORT_SYMBOL_GPL(clk_set_parent);
2617 static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
2621 lockdep_assert_held(&prepare_lock);
2626 if (clk_core_rate_is_protected(core))
2629 trace_clk_set_phase(core, degrees);
2631 if (core->ops->set_phase) {
2632 ret = core->ops->set_phase(core->hw, degrees);
2634 core->phase = degrees;
2637 trace_clk_set_phase_complete(core, degrees);
2643 * clk_set_phase - adjust the phase shift of a clock signal
2644 * @clk: clock signal source
2645 * @degrees: number of degrees the signal is shifted
2647 * Shifts the phase of a clock signal by the specified
2648 * degrees. Returns 0 on success, -EERROR otherwise.
2650 * This function makes no distinction about the input or reference
2651 * signal that we adjust the clock signal phase against. For example
2652 * phase locked-loop clock signal generators we may shift phase with
2653 * respect to feedback clock signal input, but for other cases the
2654 * clock phase may be shifted with respect to some other, unspecified
2657 * Additionally the concept of phase shift does not propagate through
2658 * the clock tree hierarchy, which sets it apart from clock rates and
2659 * clock accuracy. A parent clock phase attribute does not have an
2660 * impact on the phase attribute of a child clock.
2662 int clk_set_phase(struct clk *clk, int degrees)
2669 /* sanity check degrees */
2676 if (clk->exclusive_count)
2677 clk_core_rate_unprotect(clk->core);
2679 ret = clk_core_set_phase_nolock(clk->core, degrees);
2681 if (clk->exclusive_count)
2682 clk_core_rate_protect(clk->core);
2684 clk_prepare_unlock();
2688 EXPORT_SYMBOL_GPL(clk_set_phase);
2690 static int clk_core_get_phase(struct clk_core *core)
2694 lockdep_assert_held(&prepare_lock);
2695 if (!core->ops->get_phase)
2698 /* Always try to update cached phase if possible */
2699 ret = core->ops->get_phase(core->hw);
2707 * clk_get_phase - return the phase shift of a clock signal
2708 * @clk: clock signal source
2710 * Returns the phase shift of a clock node in degrees, otherwise returns
2713 int clk_get_phase(struct clk *clk)
2721 ret = clk_core_get_phase(clk->core);
2722 clk_prepare_unlock();
2726 EXPORT_SYMBOL_GPL(clk_get_phase);
2728 static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
2730 /* Assume a default value of 50% */
2735 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);
2737 static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
2739 struct clk_duty *duty = &core->duty;
2742 if (!core->ops->get_duty_cycle)
2743 return clk_core_update_duty_cycle_parent_nolock(core);
2745 ret = core->ops->get_duty_cycle(core->hw, duty);
2749 /* Don't trust the clock provider too much */
2750 if (duty->den == 0 || duty->num > duty->den) {
2758 clk_core_reset_duty_cycle_nolock(core);
2762 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
2767 core->flags & CLK_DUTY_CYCLE_PARENT) {
2768 ret = clk_core_update_duty_cycle_nolock(core->parent);
2769 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
2771 clk_core_reset_duty_cycle_nolock(core);
2777 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
2778 struct clk_duty *duty);
2780 static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
2781 struct clk_duty *duty)
2785 lockdep_assert_held(&prepare_lock);
2787 if (clk_core_rate_is_protected(core))
2790 trace_clk_set_duty_cycle(core, duty);
2792 if (!core->ops->set_duty_cycle)
2793 return clk_core_set_duty_cycle_parent_nolock(core, duty);
2795 ret = core->ops->set_duty_cycle(core->hw, duty);
2797 memcpy(&core->duty, duty, sizeof(*duty));
2799 trace_clk_set_duty_cycle_complete(core, duty);
2804 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
2805 struct clk_duty *duty)
2810 core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
2811 ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
2812 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
2819 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
2820 * @clk: clock signal source
2821 * @num: numerator of the duty cycle ratio to be applied
2822 * @den: denominator of the duty cycle ratio to be applied
2824 * Apply the duty cycle ratio if the ratio is valid and the clock can
2825 * perform this operation
2827 * Returns (0) on success, a negative errno otherwise.
2829 int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
2832 struct clk_duty duty;
2837 /* sanity check the ratio */
2838 if (den == 0 || num > den)
2846 if (clk->exclusive_count)
2847 clk_core_rate_unprotect(clk->core);
2849 ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
2851 if (clk->exclusive_count)
2852 clk_core_rate_protect(clk->core);
2854 clk_prepare_unlock();
2858 EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
2860 static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
2863 struct clk_duty *duty = &core->duty;
2868 ret = clk_core_update_duty_cycle_nolock(core);
2870 ret = mult_frac(scale, duty->num, duty->den);
2872 clk_prepare_unlock();
2878 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
2879 * @clk: clock signal source
2880 * @scale: scaling factor to be applied to represent the ratio as an integer
2882 * Returns the duty cycle ratio of a clock node multiplied by the provided
2883 * scaling factor, or negative errno on error.
2885 int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
2890 return clk_core_get_scaled_duty_cycle(clk->core, scale);
2892 EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
2895 * clk_is_match - check if two clk's point to the same hardware clock
2896 * @p: clk compared against q
2897 * @q: clk compared against p
2899 * Returns true if the two struct clk pointers both point to the same hardware
2900 * clock node. Put differently, returns true if struct clk *p and struct clk *q
2901 * share the same struct clk_core object.
2903 * Returns false otherwise. Note that two NULL clks are treated as matching.
2905 bool clk_is_match(const struct clk *p, const struct clk *q)
2907 /* trivial case: identical struct clk's or both NULL */
2911 /* true if clk->core pointers match. Avoid dereferencing garbage */
2912 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
2913 if (p->core == q->core)
2918 EXPORT_SYMBOL_GPL(clk_is_match);
2920 /*** debugfs support ***/
2922 #ifdef CONFIG_DEBUG_FS
2923 #include <linux/debugfs.h>
2925 static struct dentry *rootdir;
2926 static int inited = 0;
2927 static DEFINE_MUTEX(clk_debug_lock);
2928 static HLIST_HEAD(clk_debug_list);
2930 static struct hlist_head *orphan_list[] = {
2935 static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
2940 seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu ",
2942 30 - level * 3, c->name,
2943 c->enable_count, c->prepare_count, c->protect_count,
2944 clk_core_get_rate_recalc(c),
2945 clk_core_get_accuracy_recalc(c));
2947 phase = clk_core_get_phase(c);
2949 seq_printf(s, "%5d", phase);
2951 seq_puts(s, "-----");
2953 seq_printf(s, " %6d", clk_core_get_scaled_duty_cycle(c, 100000));
2955 if (c->ops->is_enabled)
2956 seq_printf(s, " %9c\n", clk_core_is_enabled(c) ? 'Y' : 'N');
2957 else if (!c->ops->enable)
2958 seq_printf(s, " %9c\n", 'Y');
2960 seq_printf(s, " %9c\n", '?');
2963 static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
2966 struct clk_core *child;
2968 clk_summary_show_one(s, c, level);
2970 hlist_for_each_entry(child, &c->children, child_node)
2971 clk_summary_show_subtree(s, child, level + 1);
2974 static int clk_summary_show(struct seq_file *s, void *data)
2977 struct hlist_head **lists = (struct hlist_head **)s->private;
2979 seq_puts(s, " enable prepare protect duty hardware\n");
2980 seq_puts(s, " clock count count count rate accuracy phase cycle enable\n");
2981 seq_puts(s, "-------------------------------------------------------------------------------------------------------\n");
2985 for (; *lists; lists++)
2986 hlist_for_each_entry(c, *lists, child_node)
2987 clk_summary_show_subtree(s, c, 0);
2989 clk_prepare_unlock();
2993 DEFINE_SHOW_ATTRIBUTE(clk_summary);
2995 static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
2998 unsigned long min_rate, max_rate;
3000 clk_core_get_boundaries(c, &min_rate, &max_rate);
3002 /* This should be JSON format, i.e. elements separated with a comma */
3003 seq_printf(s, "\"%s\": { ", c->name);
3004 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
3005 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
3006 seq_printf(s, "\"protect_count\": %d,", c->protect_count);
3007 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate_recalc(c));
3008 seq_printf(s, "\"min_rate\": %lu,", min_rate);
3009 seq_printf(s, "\"max_rate\": %lu,", max_rate);
3010 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy_recalc(c));
3011 phase = clk_core_get_phase(c);
3013 seq_printf(s, "\"phase\": %d,", phase);
3014 seq_printf(s, "\"duty_cycle\": %u",
3015 clk_core_get_scaled_duty_cycle(c, 100000));
3018 static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
3020 struct clk_core *child;
3022 clk_dump_one(s, c, level);
3024 hlist_for_each_entry(child, &c->children, child_node) {
3026 clk_dump_subtree(s, child, level + 1);
3032 static int clk_dump_show(struct seq_file *s, void *data)
3035 bool first_node = true;
3036 struct hlist_head **lists = (struct hlist_head **)s->private;
3041 for (; *lists; lists++) {
3042 hlist_for_each_entry(c, *lists, child_node) {
3046 clk_dump_subtree(s, c, 0);
3050 clk_prepare_unlock();
3055 DEFINE_SHOW_ATTRIBUTE(clk_dump);
3057 #undef CLOCK_ALLOW_WRITE_DEBUGFS
3058 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3060 * This can be dangerous, therefore don't provide any real compile time
3061 * configuration option for this feature.
3062 * People who want to use this will need to modify the source code directly.
3064 static int clk_rate_set(void *data, u64 val)
3066 struct clk_core *core = data;
3070 ret = clk_core_set_rate_nolock(core, val);
3071 clk_prepare_unlock();
3076 #define clk_rate_mode 0644
3078 static int clk_prepare_enable_set(void *data, u64 val)
3080 struct clk_core *core = data;
3084 ret = clk_prepare_enable(core->hw->clk);
3086 clk_disable_unprepare(core->hw->clk);
3091 static int clk_prepare_enable_get(void *data, u64 *val)
3093 struct clk_core *core = data;
3095 *val = core->enable_count && core->prepare_count;
3099 DEFINE_DEBUGFS_ATTRIBUTE(clk_prepare_enable_fops, clk_prepare_enable_get,
3100 clk_prepare_enable_set, "%llu\n");
3103 #define clk_rate_set NULL
3104 #define clk_rate_mode 0444
3107 static int clk_rate_get(void *data, u64 *val)
3109 struct clk_core *core = data;
3115 DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops, clk_rate_get, clk_rate_set, "%llu\n");
3117 static const struct {
3121 #define ENTRY(f) { f, #f }
3122 ENTRY(CLK_SET_RATE_GATE),
3123 ENTRY(CLK_SET_PARENT_GATE),
3124 ENTRY(CLK_SET_RATE_PARENT),
3125 ENTRY(CLK_IGNORE_UNUSED),
3126 ENTRY(CLK_GET_RATE_NOCACHE),
3127 ENTRY(CLK_SET_RATE_NO_REPARENT),
3128 ENTRY(CLK_GET_ACCURACY_NOCACHE),
3129 ENTRY(CLK_RECALC_NEW_RATES),
3130 ENTRY(CLK_SET_RATE_UNGATE),
3131 ENTRY(CLK_IS_CRITICAL),
3132 ENTRY(CLK_OPS_PARENT_ENABLE),
3133 ENTRY(CLK_DUTY_CYCLE_PARENT),
3137 static int clk_flags_show(struct seq_file *s, void *data)
3139 struct clk_core *core = s->private;
3140 unsigned long flags = core->flags;
3143 for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
3144 if (flags & clk_flags[i].flag) {
3145 seq_printf(s, "%s\n", clk_flags[i].name);
3146 flags &= ~clk_flags[i].flag;
3151 seq_printf(s, "0x%lx\n", flags);
3156 DEFINE_SHOW_ATTRIBUTE(clk_flags);
3158 static void possible_parent_show(struct seq_file *s, struct clk_core *core,
3159 unsigned int i, char terminator)
3161 struct clk_core *parent;
3164 * Go through the following options to fetch a parent's name.
3166 * 1. Fetch the registered parent clock and use its name
3167 * 2. Use the global (fallback) name if specified
3168 * 3. Use the local fw_name if provided
3169 * 4. Fetch parent clock's clock-output-name if DT index was set
3171 * This may still fail in some cases, such as when the parent is
3172 * specified directly via a struct clk_hw pointer, but it isn't
3175 parent = clk_core_get_parent_by_index(core, i);
3177 seq_puts(s, parent->name);
3178 else if (core->parents[i].name)
3179 seq_puts(s, core->parents[i].name);
3180 else if (core->parents[i].fw_name)
3181 seq_printf(s, "<%s>(fw)", core->parents[i].fw_name);
3182 else if (core->parents[i].index >= 0)
3184 of_clk_get_parent_name(core->of_node,
3185 core->parents[i].index));
3187 seq_puts(s, "(missing)");
3189 seq_putc(s, terminator);
3192 static int possible_parents_show(struct seq_file *s, void *data)
3194 struct clk_core *core = s->private;
3197 for (i = 0; i < core->num_parents - 1; i++)
3198 possible_parent_show(s, core, i, ' ');
3200 possible_parent_show(s, core, i, '\n');
3204 DEFINE_SHOW_ATTRIBUTE(possible_parents);
3206 static int current_parent_show(struct seq_file *s, void *data)
3208 struct clk_core *core = s->private;
3211 seq_printf(s, "%s\n", core->parent->name);
3215 DEFINE_SHOW_ATTRIBUTE(current_parent);
3217 static int clk_duty_cycle_show(struct seq_file *s, void *data)
3219 struct clk_core *core = s->private;
3220 struct clk_duty *duty = &core->duty;
3222 seq_printf(s, "%u/%u\n", duty->num, duty->den);
3226 DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
3228 static int clk_min_rate_show(struct seq_file *s, void *data)
3230 struct clk_core *core = s->private;
3231 unsigned long min_rate, max_rate;
3234 clk_core_get_boundaries(core, &min_rate, &max_rate);
3235 clk_prepare_unlock();
3236 seq_printf(s, "%lu\n", min_rate);
3240 DEFINE_SHOW_ATTRIBUTE(clk_min_rate);
3242 static int clk_max_rate_show(struct seq_file *s, void *data)
3244 struct clk_core *core = s->private;
3245 unsigned long min_rate, max_rate;
3248 clk_core_get_boundaries(core, &min_rate, &max_rate);
3249 clk_prepare_unlock();
3250 seq_printf(s, "%lu\n", max_rate);
3254 DEFINE_SHOW_ATTRIBUTE(clk_max_rate);
3256 static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
3258 struct dentry *root;
3260 if (!core || !pdentry)
3263 root = debugfs_create_dir(core->name, pdentry);
3264 core->dentry = root;
3266 debugfs_create_file("clk_rate", clk_rate_mode, root, core,
3268 debugfs_create_file("clk_min_rate", 0444, root, core, &clk_min_rate_fops);
3269 debugfs_create_file("clk_max_rate", 0444, root, core, &clk_max_rate_fops);
3270 debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
3271 debugfs_create_u32("clk_phase", 0444, root, &core->phase);
3272 debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
3273 debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
3274 debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
3275 debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
3276 debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
3277 debugfs_create_file("clk_duty_cycle", 0444, root, core,
3278 &clk_duty_cycle_fops);
3279 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3280 debugfs_create_file("clk_prepare_enable", 0644, root, core,
3281 &clk_prepare_enable_fops);
3284 if (core->num_parents > 0)
3285 debugfs_create_file("clk_parent", 0444, root, core,
3286 ¤t_parent_fops);
3288 if (core->num_parents > 1)
3289 debugfs_create_file("clk_possible_parents", 0444, root, core,
3290 &possible_parents_fops);
3292 if (core->ops->debug_init)
3293 core->ops->debug_init(core->hw, core->dentry);
3297 * clk_debug_register - add a clk node to the debugfs clk directory
3298 * @core: the clk being added to the debugfs clk directory
3300 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
3301 * initialized. Otherwise it bails out early since the debugfs clk directory
3302 * will be created lazily by clk_debug_init as part of a late_initcall.
3304 static void clk_debug_register(struct clk_core *core)
3306 mutex_lock(&clk_debug_lock);
3307 hlist_add_head(&core->debug_node, &clk_debug_list);
3309 clk_debug_create_one(core, rootdir);
3310 mutex_unlock(&clk_debug_lock);
3314 * clk_debug_unregister - remove a clk node from the debugfs clk directory
3315 * @core: the clk being removed from the debugfs clk directory
3317 * Dynamically removes a clk and all its child nodes from the
3318 * debugfs clk directory if clk->dentry points to debugfs created by
3319 * clk_debug_register in __clk_core_init.
3321 static void clk_debug_unregister(struct clk_core *core)
3323 mutex_lock(&clk_debug_lock);
3324 hlist_del_init(&core->debug_node);
3325 debugfs_remove_recursive(core->dentry);
3326 core->dentry = NULL;
3327 mutex_unlock(&clk_debug_lock);
3331 * clk_debug_init - lazily populate the debugfs clk directory
3333 * clks are often initialized very early during boot before memory can be
3334 * dynamically allocated and well before debugfs is setup. This function
3335 * populates the debugfs clk directory once at boot-time when we know that
3336 * debugfs is setup. It should only be called once at boot-time, all other clks
3337 * added dynamically will be done so with clk_debug_register.
3339 static int __init clk_debug_init(void)
3341 struct clk_core *core;
3343 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3345 pr_warn("********************************************************************\n");
3346 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
3348 pr_warn("** WRITEABLE clk DebugFS SUPPORT HAS BEEN ENABLED IN THIS KERNEL **\n");
3350 pr_warn("** This means that this kernel is built to expose clk operations **\n");
3351 pr_warn("** such as parent or rate setting, enabling, disabling, etc. **\n");
3352 pr_warn("** to userspace, which may compromise security on your system. **\n");
3354 pr_warn("** If you see this message and you are not debugging the **\n");
3355 pr_warn("** kernel, report this immediately to your vendor! **\n");
3357 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
3358 pr_warn("********************************************************************\n");
3361 rootdir = debugfs_create_dir("clk", NULL);
3363 debugfs_create_file("clk_summary", 0444, rootdir, &all_lists,
3365 debugfs_create_file("clk_dump", 0444, rootdir, &all_lists,
3367 debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list,
3369 debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list,
3372 mutex_lock(&clk_debug_lock);
3373 hlist_for_each_entry(core, &clk_debug_list, debug_node)
3374 clk_debug_create_one(core, rootdir);
3377 mutex_unlock(&clk_debug_lock);
3381 late_initcall(clk_debug_init);
3383 static inline void clk_debug_register(struct clk_core *core) { }
3384 static inline void clk_debug_unregister(struct clk_core *core)
3389 static void clk_core_reparent_orphans_nolock(void)
3391 struct clk_core *orphan;
3392 struct hlist_node *tmp2;
3395 * walk the list of orphan clocks and reparent any that newly finds a
3398 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
3399 struct clk_core *parent = __clk_init_parent(orphan);
3402 * We need to use __clk_set_parent_before() and _after() to
3403 * to properly migrate any prepare/enable count of the orphan
3404 * clock. This is important for CLK_IS_CRITICAL clocks, which
3405 * are enabled during init but might not have a parent yet.
3408 /* update the clk tree topology */
3409 __clk_set_parent_before(orphan, parent);
3410 __clk_set_parent_after(orphan, parent, NULL);
3411 __clk_recalc_accuracies(orphan);
3412 __clk_recalc_rates(orphan, 0);
3418 * __clk_core_init - initialize the data structures in a struct clk_core
3419 * @core: clk_core being initialized
3421 * Initializes the lists in struct clk_core, queries the hardware for the
3422 * parent and rate and sets them both.
3424 static int __clk_core_init(struct clk_core *core)
3427 struct clk_core *parent;
3437 * Set hw->core after grabbing the prepare_lock to synchronize with
3438 * callers of clk_core_fill_parent_index() where we treat hw->core
3439 * being NULL as the clk not being registered yet. This is crucial so
3440 * that clks aren't parented until their parent is fully registered.
3442 core->hw->core = core;
3444 ret = clk_pm_runtime_get(core);
3448 /* check to see if a clock with this name is already registered */
3449 if (clk_core_lookup(core->name)) {
3450 pr_debug("%s: clk %s already initialized\n",
3451 __func__, core->name);
3456 /* check that clk_ops are sane. See Documentation/driver-api/clk.rst */
3457 if (core->ops->set_rate &&
3458 !((core->ops->round_rate || core->ops->determine_rate) &&
3459 core->ops->recalc_rate)) {
3460 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
3461 __func__, core->name);
3466 if (core->ops->set_parent && !core->ops->get_parent) {
3467 pr_err("%s: %s must implement .get_parent & .set_parent\n",
3468 __func__, core->name);
3473 if (core->num_parents > 1 && !core->ops->get_parent) {
3474 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
3475 __func__, core->name);
3480 if (core->ops->set_rate_and_parent &&
3481 !(core->ops->set_parent && core->ops->set_rate)) {
3482 pr_err("%s: %s must implement .set_parent & .set_rate\n",
3483 __func__, core->name);
3489 * optional platform-specific magic
3491 * The .init callback is not used by any of the basic clock types, but
3492 * exists for weird hardware that must perform initialization magic for
3493 * CCF to get an accurate view of clock for any other callbacks. It may
3494 * also be used needs to perform dynamic allocations. Such allocation
3495 * must be freed in the terminate() callback.
3496 * This callback shall not be used to initialize the parameters state,
3497 * such as rate, parent, etc ...
3499 * If it exist, this callback should called before any other callback of
3502 if (core->ops->init) {
3503 ret = core->ops->init(core->hw);
3508 parent = core->parent = __clk_init_parent(core);
3511 * Populate core->parent if parent has already been clk_core_init'd. If
3512 * parent has not yet been clk_core_init'd then place clk in the orphan
3513 * list. If clk doesn't have any parents then place it in the root
3516 * Every time a new clk is clk_init'd then we walk the list of orphan
3517 * clocks and re-parent any that are children of the clock currently
3521 hlist_add_head(&core->child_node, &parent->children);
3522 core->orphan = parent->orphan;
3523 } else if (!core->num_parents) {
3524 hlist_add_head(&core->child_node, &clk_root_list);
3525 core->orphan = false;
3527 hlist_add_head(&core->child_node, &clk_orphan_list);
3528 core->orphan = true;
3532 * Set clk's accuracy. The preferred method is to use
3533 * .recalc_accuracy. For simple clocks and lazy developers the default
3534 * fallback is to use the parent's accuracy. If a clock doesn't have a
3535 * parent (or is orphaned) then accuracy is set to zero (perfect
3538 if (core->ops->recalc_accuracy)
3539 core->accuracy = core->ops->recalc_accuracy(core->hw,
3540 clk_core_get_accuracy_no_lock(parent));
3542 core->accuracy = parent->accuracy;
3547 * Set clk's phase by clk_core_get_phase() caching the phase.
3548 * Since a phase is by definition relative to its parent, just
3549 * query the current clock phase, or just assume it's in phase.
3551 phase = clk_core_get_phase(core);
3554 pr_warn("%s: Failed to get phase for clk '%s'\n", __func__,
3560 * Set clk's duty cycle.
3562 clk_core_update_duty_cycle_nolock(core);
3565 * Set clk's rate. The preferred method is to use .recalc_rate. For
3566 * simple clocks and lazy developers the default fallback is to use the
3567 * parent's rate. If a clock doesn't have a parent (or is orphaned)
3568 * then rate is set to zero.
3570 if (core->ops->recalc_rate)
3571 rate = core->ops->recalc_rate(core->hw,
3572 clk_core_get_rate_nolock(parent));
3574 rate = parent->rate;
3577 core->rate = core->req_rate = rate;
3580 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
3581 * don't get accidentally disabled when walking the orphan tree and
3582 * reparenting clocks
3584 if (core->flags & CLK_IS_CRITICAL) {
3585 ret = clk_core_prepare(core);
3587 pr_warn("%s: critical clk '%s' failed to prepare\n",
3588 __func__, core->name);
3592 ret = clk_core_enable_lock(core);
3594 pr_warn("%s: critical clk '%s' failed to enable\n",
3595 __func__, core->name);
3596 clk_core_unprepare(core);
3601 clk_core_reparent_orphans_nolock();
3604 kref_init(&core->ref);
3606 clk_pm_runtime_put(core);
3609 hlist_del_init(&core->child_node);
3610 core->hw->core = NULL;
3613 clk_prepare_unlock();
3616 clk_debug_register(core);
3622 * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core
3623 * @core: clk to add consumer to
3624 * @clk: consumer to link to a clk
3626 static void clk_core_link_consumer(struct clk_core *core, struct clk *clk)
3629 hlist_add_head(&clk->clks_node, &core->clks);
3630 clk_prepare_unlock();
3634 * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core
3635 * @clk: consumer to unlink
3637 static void clk_core_unlink_consumer(struct clk *clk)
3639 lockdep_assert_held(&prepare_lock);
3640 hlist_del(&clk->clks_node);
3644 * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core
3645 * @core: clk to allocate a consumer for
3646 * @dev_id: string describing device name
3647 * @con_id: connection ID string on device
3649 * Returns: clk consumer left unlinked from the consumer list
3651 static struct clk *alloc_clk(struct clk_core *core, const char *dev_id,
3656 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
3658 return ERR_PTR(-ENOMEM);
3661 clk->dev_id = dev_id;
3662 clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
3663 clk->max_rate = ULONG_MAX;
3669 * free_clk - Free a clk consumer
3670 * @clk: clk consumer to free
3672 * Note, this assumes the clk has been unlinked from the clk_core consumer
3675 static void free_clk(struct clk *clk)
3677 kfree_const(clk->con_id);
3682 * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given
3684 * @dev: clk consumer device
3685 * @hw: clk_hw associated with the clk being consumed
3686 * @dev_id: string describing device name
3687 * @con_id: connection ID string on device
3689 * This is the main function used to create a clk pointer for use by clk
3690 * consumers. It connects a consumer to the clk_core and clk_hw structures
3691 * used by the framework and clk provider respectively.
3693 struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
3694 const char *dev_id, const char *con_id)
3697 struct clk_core *core;
3699 /* This is to allow this function to be chained to others */
3700 if (IS_ERR_OR_NULL(hw))
3701 return ERR_CAST(hw);
3704 clk = alloc_clk(core, dev_id, con_id);
3709 if (!try_module_get(core->owner)) {
3711 return ERR_PTR(-ENOENT);
3714 kref_get(&core->ref);
3715 clk_core_link_consumer(core, clk);
3721 * clk_hw_get_clk - get clk consumer given an clk_hw
3722 * @hw: clk_hw associated with the clk being consumed
3723 * @con_id: connection ID string on device
3725 * Returns: new clk consumer
3726 * This is the function to be used by providers which need
3727 * to get a consumer clk and act on the clock element
3728 * Calls to this function must be balanced with calls clk_put()
3730 struct clk *clk_hw_get_clk(struct clk_hw *hw, const char *con_id)
3732 struct device *dev = hw->core->dev;
3734 return clk_hw_create_clk(dev, hw, dev_name(dev), con_id);
3736 EXPORT_SYMBOL(clk_hw_get_clk);
3738 static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
3748 *dst_p = dst = kstrdup_const(src, GFP_KERNEL);
3755 static int clk_core_populate_parent_map(struct clk_core *core,
3756 const struct clk_init_data *init)
3758 u8 num_parents = init->num_parents;
3759 const char * const *parent_names = init->parent_names;
3760 const struct clk_hw **parent_hws = init->parent_hws;
3761 const struct clk_parent_data *parent_data = init->parent_data;
3763 struct clk_parent_map *parents, *parent;
3769 * Avoid unnecessary string look-ups of clk_core's possible parents by
3770 * having a cache of names/clk_hw pointers to clk_core pointers.
3772 parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
3773 core->parents = parents;
3777 /* Copy everything over because it might be __initdata */
3778 for (i = 0, parent = parents; i < num_parents; i++, parent++) {
3781 /* throw a WARN if any entries are NULL */
3782 WARN(!parent_names[i],
3783 "%s: invalid NULL in %s's .parent_names\n",
3784 __func__, core->name);
3785 ret = clk_cpy_name(&parent->name, parent_names[i],
3787 } else if (parent_data) {
3788 parent->hw = parent_data[i].hw;
3789 parent->index = parent_data[i].index;
3790 ret = clk_cpy_name(&parent->fw_name,
3791 parent_data[i].fw_name, false);
3793 ret = clk_cpy_name(&parent->name,
3794 parent_data[i].name,
3796 } else if (parent_hws) {
3797 parent->hw = parent_hws[i];
3800 WARN(1, "Must specify parents if num_parents > 0\n");
3805 kfree_const(parents[i].name);
3806 kfree_const(parents[i].fw_name);
3817 static void clk_core_free_parent_map(struct clk_core *core)
3819 int i = core->num_parents;
3821 if (!core->num_parents)
3825 kfree_const(core->parents[i].name);
3826 kfree_const(core->parents[i].fw_name);
3829 kfree(core->parents);
3833 __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
3836 struct clk_core *core;
3837 const struct clk_init_data *init = hw->init;
3840 * The init data is not supposed to be used outside of registration path.
3841 * Set it to NULL so that provider drivers can't use it either and so that
3842 * we catch use of hw->init early on in the core.
3846 core = kzalloc(sizeof(*core), GFP_KERNEL);
3852 core->name = kstrdup_const(init->name, GFP_KERNEL);
3858 if (WARN_ON(!init->ops)) {
3862 core->ops = init->ops;
3864 if (dev && pm_runtime_enabled(dev))
3865 core->rpm_enabled = true;
3868 if (dev && dev->driver)
3869 core->owner = dev->driver->owner;
3871 core->flags = init->flags;
3872 core->num_parents = init->num_parents;
3874 core->max_rate = ULONG_MAX;
3876 ret = clk_core_populate_parent_map(core, init);
3880 INIT_HLIST_HEAD(&core->clks);
3883 * Don't call clk_hw_create_clk() here because that would pin the
3884 * provider module to itself and prevent it from ever being removed.
3886 hw->clk = alloc_clk(core, NULL, NULL);
3887 if (IS_ERR(hw->clk)) {
3888 ret = PTR_ERR(hw->clk);
3889 goto fail_create_clk;
3892 clk_core_link_consumer(core, hw->clk);
3894 ret = __clk_core_init(core);
3899 clk_core_unlink_consumer(hw->clk);
3900 clk_prepare_unlock();
3906 clk_core_free_parent_map(core);
3909 kfree_const(core->name);
3913 return ERR_PTR(ret);
3917 * dev_or_parent_of_node() - Get device node of @dev or @dev's parent
3918 * @dev: Device to get device node of
3920 * Return: device node pointer of @dev, or the device node pointer of
3921 * @dev->parent if dev doesn't have a device node, or NULL if neither
3922 * @dev or @dev->parent have a device node.
3924 static struct device_node *dev_or_parent_of_node(struct device *dev)
3926 struct device_node *np;
3931 np = dev_of_node(dev);
3933 np = dev_of_node(dev->parent);
3939 * clk_register - allocate a new clock, register it and return an opaque cookie
3940 * @dev: device that is registering this clock
3941 * @hw: link to hardware-specific clock data
3943 * clk_register is the *deprecated* interface for populating the clock tree with
3944 * new clock nodes. Use clk_hw_register() instead.
3946 * Returns: a pointer to the newly allocated struct clk which
3947 * cannot be dereferenced by driver code but may be used in conjunction with the
3948 * rest of the clock API. In the event of an error clk_register will return an
3949 * error code; drivers must test for an error code after calling clk_register.
3951 struct clk *clk_register(struct device *dev, struct clk_hw *hw)
3953 return __clk_register(dev, dev_or_parent_of_node(dev), hw);
3955 EXPORT_SYMBOL_GPL(clk_register);
3958 * clk_hw_register - register a clk_hw and return an error code
3959 * @dev: device that is registering this clock
3960 * @hw: link to hardware-specific clock data
3962 * clk_hw_register is the primary interface for populating the clock tree with
3963 * new clock nodes. It returns an integer equal to zero indicating success or
3964 * less than zero indicating failure. Drivers must test for an error code after
3965 * calling clk_hw_register().
3967 int clk_hw_register(struct device *dev, struct clk_hw *hw)
3969 return PTR_ERR_OR_ZERO(__clk_register(dev, dev_or_parent_of_node(dev),
3972 EXPORT_SYMBOL_GPL(clk_hw_register);
3975 * of_clk_hw_register - register a clk_hw and return an error code
3976 * @node: device_node of device that is registering this clock
3977 * @hw: link to hardware-specific clock data
3979 * of_clk_hw_register() is the primary interface for populating the clock tree
3980 * with new clock nodes when a struct device is not available, but a struct
3981 * device_node is. It returns an integer equal to zero indicating success or
3982 * less than zero indicating failure. Drivers must test for an error code after
3983 * calling of_clk_hw_register().
3985 int of_clk_hw_register(struct device_node *node, struct clk_hw *hw)
3987 return PTR_ERR_OR_ZERO(__clk_register(NULL, node, hw));
3989 EXPORT_SYMBOL_GPL(of_clk_hw_register);
3991 /* Free memory allocated for a clock. */
3992 static void __clk_release(struct kref *ref)
3994 struct clk_core *core = container_of(ref, struct clk_core, ref);
3996 lockdep_assert_held(&prepare_lock);
3998 clk_core_free_parent_map(core);
3999 kfree_const(core->name);
4004 * Empty clk_ops for unregistered clocks. These are used temporarily
4005 * after clk_unregister() was called on a clock and until last clock
4006 * consumer calls clk_put() and the struct clk object is freed.
4008 static int clk_nodrv_prepare_enable(struct clk_hw *hw)
4013 static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
4018 static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
4019 unsigned long parent_rate)
4024 static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
4029 static const struct clk_ops clk_nodrv_ops = {
4030 .enable = clk_nodrv_prepare_enable,
4031 .disable = clk_nodrv_disable_unprepare,
4032 .prepare = clk_nodrv_prepare_enable,
4033 .unprepare = clk_nodrv_disable_unprepare,
4034 .set_rate = clk_nodrv_set_rate,
4035 .set_parent = clk_nodrv_set_parent,
4038 static void clk_core_evict_parent_cache_subtree(struct clk_core *root,
4039 struct clk_core *target)
4042 struct clk_core *child;
4044 for (i = 0; i < root->num_parents; i++)
4045 if (root->parents[i].core == target)
4046 root->parents[i].core = NULL;
4048 hlist_for_each_entry(child, &root->children, child_node)
4049 clk_core_evict_parent_cache_subtree(child, target);
4052 /* Remove this clk from all parent caches */
4053 static void clk_core_evict_parent_cache(struct clk_core *core)
4055 struct hlist_head **lists;
4056 struct clk_core *root;
4058 lockdep_assert_held(&prepare_lock);
4060 for (lists = all_lists; *lists; lists++)
4061 hlist_for_each_entry(root, *lists, child_node)
4062 clk_core_evict_parent_cache_subtree(root, core);
4067 * clk_unregister - unregister a currently registered clock
4068 * @clk: clock to unregister
4070 void clk_unregister(struct clk *clk)
4072 unsigned long flags;
4073 const struct clk_ops *ops;
4075 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4078 clk_debug_unregister(clk->core);
4082 ops = clk->core->ops;
4083 if (ops == &clk_nodrv_ops) {
4084 pr_err("%s: unregistered clock: %s\n", __func__,
4089 * Assign empty clock ops for consumers that might still hold
4090 * a reference to this clock.
4092 flags = clk_enable_lock();
4093 clk->core->ops = &clk_nodrv_ops;
4094 clk_enable_unlock(flags);
4097 ops->terminate(clk->core->hw);
4099 if (!hlist_empty(&clk->core->children)) {
4100 struct clk_core *child;
4101 struct hlist_node *t;
4103 /* Reparent all children to the orphan list. */
4104 hlist_for_each_entry_safe(child, t, &clk->core->children,
4106 clk_core_set_parent_nolock(child, NULL);
4109 clk_core_evict_parent_cache(clk->core);
4111 hlist_del_init(&clk->core->child_node);
4113 if (clk->core->prepare_count)
4114 pr_warn("%s: unregistering prepared clock: %s\n",
4115 __func__, clk->core->name);
4117 if (clk->core->protect_count)
4118 pr_warn("%s: unregistering protected clock: %s\n",
4119 __func__, clk->core->name);
4121 kref_put(&clk->core->ref, __clk_release);
4124 clk_prepare_unlock();
4126 EXPORT_SYMBOL_GPL(clk_unregister);
4129 * clk_hw_unregister - unregister a currently registered clk_hw
4130 * @hw: hardware-specific clock data to unregister
4132 void clk_hw_unregister(struct clk_hw *hw)
4134 clk_unregister(hw->clk);
4136 EXPORT_SYMBOL_GPL(clk_hw_unregister);
4138 static void devm_clk_unregister_cb(struct device *dev, void *res)
4140 clk_unregister(*(struct clk **)res);
4143 static void devm_clk_hw_unregister_cb(struct device *dev, void *res)
4145 clk_hw_unregister(*(struct clk_hw **)res);
4149 * devm_clk_register - resource managed clk_register()
4150 * @dev: device that is registering this clock
4151 * @hw: link to hardware-specific clock data
4153 * Managed clk_register(). This function is *deprecated*, use devm_clk_hw_register() instead.
4155 * Clocks returned from this function are automatically clk_unregister()ed on
4156 * driver detach. See clk_register() for more information.
4158 struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
4163 clkp = devres_alloc(devm_clk_unregister_cb, sizeof(*clkp), GFP_KERNEL);
4165 return ERR_PTR(-ENOMEM);
4167 clk = clk_register(dev, hw);
4170 devres_add(dev, clkp);
4177 EXPORT_SYMBOL_GPL(devm_clk_register);
4180 * devm_clk_hw_register - resource managed clk_hw_register()
4181 * @dev: device that is registering this clock
4182 * @hw: link to hardware-specific clock data
4184 * Managed clk_hw_register(). Clocks registered by this function are
4185 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
4186 * for more information.
4188 int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
4190 struct clk_hw **hwp;
4193 hwp = devres_alloc(devm_clk_hw_unregister_cb, sizeof(*hwp), GFP_KERNEL);
4197 ret = clk_hw_register(dev, hw);
4200 devres_add(dev, hwp);
4207 EXPORT_SYMBOL_GPL(devm_clk_hw_register);
4209 static int devm_clk_match(struct device *dev, void *res, void *data)
4211 struct clk *c = res;
4217 static int devm_clk_hw_match(struct device *dev, void *res, void *data)
4219 struct clk_hw *hw = res;
4227 * devm_clk_unregister - resource managed clk_unregister()
4228 * @dev: device that is unregistering the clock data
4229 * @clk: clock to unregister
4231 * Deallocate a clock allocated with devm_clk_register(). Normally
4232 * this function will not need to be called and the resource management
4233 * code will ensure that the resource is freed.
4235 void devm_clk_unregister(struct device *dev, struct clk *clk)
4237 WARN_ON(devres_release(dev, devm_clk_unregister_cb, devm_clk_match, clk));
4239 EXPORT_SYMBOL_GPL(devm_clk_unregister);
4242 * devm_clk_hw_unregister - resource managed clk_hw_unregister()
4243 * @dev: device that is unregistering the hardware-specific clock data
4244 * @hw: link to hardware-specific clock data
4246 * Unregister a clk_hw registered with devm_clk_hw_register(). Normally
4247 * this function will not need to be called and the resource management
4248 * code will ensure that the resource is freed.
4250 void devm_clk_hw_unregister(struct device *dev, struct clk_hw *hw)
4252 WARN_ON(devres_release(dev, devm_clk_hw_unregister_cb, devm_clk_hw_match,
4255 EXPORT_SYMBOL_GPL(devm_clk_hw_unregister);
4257 static void devm_clk_release(struct device *dev, void *res)
4259 clk_put(*(struct clk **)res);
4263 * devm_clk_hw_get_clk - resource managed clk_hw_get_clk()
4264 * @dev: device that is registering this clock
4265 * @hw: clk_hw associated with the clk being consumed
4266 * @con_id: connection ID string on device
4268 * Managed clk_hw_get_clk(). Clocks got with this function are
4269 * automatically clk_put() on driver detach. See clk_put()
4270 * for more information.
4272 struct clk *devm_clk_hw_get_clk(struct device *dev, struct clk_hw *hw,
4278 /* This should not happen because it would mean we have drivers
4279 * passing around clk_hw pointers instead of having the caller use
4280 * proper clk_get() style APIs
4282 WARN_ON_ONCE(dev != hw->core->dev);
4284 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
4286 return ERR_PTR(-ENOMEM);
4288 clk = clk_hw_get_clk(hw, con_id);
4291 devres_add(dev, clkp);
4298 EXPORT_SYMBOL_GPL(devm_clk_hw_get_clk);
4304 void __clk_put(struct clk *clk)
4306 struct module *owner;
4308 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4314 * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
4315 * given user should be balanced with calls to clk_rate_exclusive_put()
4316 * and by that same consumer
4318 if (WARN_ON(clk->exclusive_count)) {
4319 /* We voiced our concern, let's sanitize the situation */
4320 clk->core->protect_count -= (clk->exclusive_count - 1);
4321 clk_core_rate_unprotect(clk->core);
4322 clk->exclusive_count = 0;
4325 hlist_del(&clk->clks_node);
4326 if (clk->min_rate > clk->core->req_rate ||
4327 clk->max_rate < clk->core->req_rate)
4328 clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
4330 owner = clk->core->owner;
4331 kref_put(&clk->core->ref, __clk_release);
4333 clk_prepare_unlock();
4340 /*** clk rate change notifiers ***/
4343 * clk_notifier_register - add a clk rate change notifier
4344 * @clk: struct clk * to watch
4345 * @nb: struct notifier_block * with callback info
4347 * Request notification when clk's rate changes. This uses an SRCU
4348 * notifier because we want it to block and notifier unregistrations are
4349 * uncommon. The callbacks associated with the notifier must not
4350 * re-enter into the clk framework by calling any top-level clk APIs;
4351 * this will cause a nested prepare_lock mutex.
4353 * In all notification cases (pre, post and abort rate change) the original
4354 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
4355 * and the new frequency is passed via struct clk_notifier_data.new_rate.
4357 * clk_notifier_register() must be called from non-atomic context.
4358 * Returns -EINVAL if called with null arguments, -ENOMEM upon
4359 * allocation failure; otherwise, passes along the return value of
4360 * srcu_notifier_chain_register().
4362 int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
4364 struct clk_notifier *cn;
4372 /* search the list of notifiers for this clk */
4373 list_for_each_entry(cn, &clk_notifier_list, node)
4377 /* if clk wasn't in the notifier list, allocate new clk_notifier */
4378 cn = kzalloc(sizeof(*cn), GFP_KERNEL);
4383 srcu_init_notifier_head(&cn->notifier_head);
4385 list_add(&cn->node, &clk_notifier_list);
4388 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
4390 clk->core->notifier_count++;
4393 clk_prepare_unlock();
4397 EXPORT_SYMBOL_GPL(clk_notifier_register);
4400 * clk_notifier_unregister - remove a clk rate change notifier
4401 * @clk: struct clk *
4402 * @nb: struct notifier_block * with callback info
4404 * Request no further notification for changes to 'clk' and frees memory
4405 * allocated in clk_notifier_register.
4407 * Returns -EINVAL if called with null arguments; otherwise, passes
4408 * along the return value of srcu_notifier_chain_unregister().
4410 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
4412 struct clk_notifier *cn;
4420 list_for_each_entry(cn, &clk_notifier_list, node) {
4421 if (cn->clk == clk) {
4422 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
4424 clk->core->notifier_count--;
4426 /* XXX the notifier code should handle this better */
4427 if (!cn->notifier_head.head) {
4428 srcu_cleanup_notifier_head(&cn->notifier_head);
4429 list_del(&cn->node);
4436 clk_prepare_unlock();
4440 EXPORT_SYMBOL_GPL(clk_notifier_unregister);
4442 struct clk_notifier_devres {
4444 struct notifier_block *nb;
4447 static void devm_clk_notifier_release(struct device *dev, void *res)
4449 struct clk_notifier_devres *devres = res;
4451 clk_notifier_unregister(devres->clk, devres->nb);
4454 int devm_clk_notifier_register(struct device *dev, struct clk *clk,
4455 struct notifier_block *nb)
4457 struct clk_notifier_devres *devres;
4460 devres = devres_alloc(devm_clk_notifier_release,
4461 sizeof(*devres), GFP_KERNEL);
4466 ret = clk_notifier_register(clk, nb);
4471 devres_free(devres);
4476 EXPORT_SYMBOL_GPL(devm_clk_notifier_register);
4479 static void clk_core_reparent_orphans(void)
4482 clk_core_reparent_orphans_nolock();
4483 clk_prepare_unlock();
4487 * struct of_clk_provider - Clock provider registration structure
4488 * @link: Entry in global list of clock providers
4489 * @node: Pointer to device tree node of clock provider
4490 * @get: Get clock callback. Returns NULL or a struct clk for the
4491 * given clock specifier
4492 * @get_hw: Get clk_hw callback. Returns NULL, ERR_PTR or a
4493 * struct clk_hw for the given clock specifier
4494 * @data: context pointer to be passed into @get callback
4496 struct of_clk_provider {
4497 struct list_head link;
4499 struct device_node *node;
4500 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
4501 struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
4505 extern struct of_device_id __clk_of_table;
4506 static const struct of_device_id __clk_of_table_sentinel
4507 __used __section("__clk_of_table_end");
4509 static LIST_HEAD(of_clk_providers);
4510 static DEFINE_MUTEX(of_clk_mutex);
4512 struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
4517 EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
4519 struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
4523 EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
4525 struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
4527 struct clk_onecell_data *clk_data = data;
4528 unsigned int idx = clkspec->args[0];
4530 if (idx >= clk_data->clk_num) {
4531 pr_err("%s: invalid clock index %u\n", __func__, idx);
4532 return ERR_PTR(-EINVAL);
4535 return clk_data->clks[idx];
4537 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
4540 of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
4542 struct clk_hw_onecell_data *hw_data = data;
4543 unsigned int idx = clkspec->args[0];
4545 if (idx >= hw_data->num) {
4546 pr_err("%s: invalid index %u\n", __func__, idx);
4547 return ERR_PTR(-EINVAL);
4550 return hw_data->hws[idx];
4552 EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
4555 * of_clk_add_provider() - Register a clock provider for a node
4556 * @np: Device node pointer associated with clock provider
4557 * @clk_src_get: callback for decoding clock
4558 * @data: context pointer for @clk_src_get callback.
4560 * This function is *deprecated*. Use of_clk_add_hw_provider() instead.
4562 int of_clk_add_provider(struct device_node *np,
4563 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
4567 struct of_clk_provider *cp;
4573 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
4577 cp->node = of_node_get(np);
4579 cp->get = clk_src_get;
4581 mutex_lock(&of_clk_mutex);
4582 list_add(&cp->link, &of_clk_providers);
4583 mutex_unlock(&of_clk_mutex);
4584 pr_debug("Added clock from %pOF\n", np);
4586 clk_core_reparent_orphans();
4588 ret = of_clk_set_defaults(np, true);
4590 of_clk_del_provider(np);
4592 fwnode_dev_initialized(&np->fwnode, true);
4596 EXPORT_SYMBOL_GPL(of_clk_add_provider);
4599 * of_clk_add_hw_provider() - Register a clock provider for a node
4600 * @np: Device node pointer associated with clock provider
4601 * @get: callback for decoding clk_hw
4602 * @data: context pointer for @get callback.
4604 int of_clk_add_hw_provider(struct device_node *np,
4605 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
4609 struct of_clk_provider *cp;
4615 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
4619 cp->node = of_node_get(np);
4623 mutex_lock(&of_clk_mutex);
4624 list_add(&cp->link, &of_clk_providers);
4625 mutex_unlock(&of_clk_mutex);
4626 pr_debug("Added clk_hw provider from %pOF\n", np);
4628 clk_core_reparent_orphans();
4630 ret = of_clk_set_defaults(np, true);
4632 of_clk_del_provider(np);
4634 fwnode_dev_initialized(&np->fwnode, true);
4638 EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
4640 static void devm_of_clk_release_provider(struct device *dev, void *res)
4642 of_clk_del_provider(*(struct device_node **)res);
4646 * We allow a child device to use its parent device as the clock provider node
4647 * for cases like MFD sub-devices where the child device driver wants to use
4648 * devm_*() APIs but not list the device in DT as a sub-node.
4650 static struct device_node *get_clk_provider_node(struct device *dev)
4652 struct device_node *np, *parent_np;
4655 parent_np = dev->parent ? dev->parent->of_node : NULL;
4657 if (!of_find_property(np, "#clock-cells", NULL))
4658 if (of_find_property(parent_np, "#clock-cells", NULL))
4665 * devm_of_clk_add_hw_provider() - Managed clk provider node registration
4666 * @dev: Device acting as the clock provider (used for DT node and lifetime)
4667 * @get: callback for decoding clk_hw
4668 * @data: context pointer for @get callback
4670 * Registers clock provider for given device's node. If the device has no DT
4671 * node or if the device node lacks of clock provider information (#clock-cells)
4672 * then the parent device's node is scanned for this information. If parent node
4673 * has the #clock-cells then it is used in registration. Provider is
4674 * automatically released at device exit.
4676 * Return: 0 on success or an errno on failure.
4678 int devm_of_clk_add_hw_provider(struct device *dev,
4679 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
4683 struct device_node **ptr, *np;
4686 ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
4691 np = get_clk_provider_node(dev);
4692 ret = of_clk_add_hw_provider(np, get, data);
4695 devres_add(dev, ptr);
4702 EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);
4705 * of_clk_del_provider() - Remove a previously registered clock provider
4706 * @np: Device node pointer associated with clock provider
4708 void of_clk_del_provider(struct device_node *np)
4710 struct of_clk_provider *cp;
4715 mutex_lock(&of_clk_mutex);
4716 list_for_each_entry(cp, &of_clk_providers, link) {
4717 if (cp->node == np) {
4718 list_del(&cp->link);
4719 fwnode_dev_initialized(&np->fwnode, false);
4720 of_node_put(cp->node);
4725 mutex_unlock(&of_clk_mutex);
4727 EXPORT_SYMBOL_GPL(of_clk_del_provider);
4729 static int devm_clk_provider_match(struct device *dev, void *res, void *data)
4731 struct device_node **np = res;
4733 if (WARN_ON(!np || !*np))
4740 * devm_of_clk_del_provider() - Remove clock provider registered using devm
4741 * @dev: Device to whose lifetime the clock provider was bound
4743 void devm_of_clk_del_provider(struct device *dev)
4746 struct device_node *np = get_clk_provider_node(dev);
4748 ret = devres_release(dev, devm_of_clk_release_provider,
4749 devm_clk_provider_match, np);
4753 EXPORT_SYMBOL(devm_of_clk_del_provider);
4756 * of_parse_clkspec() - Parse a DT clock specifier for a given device node
4757 * @np: device node to parse clock specifier from
4758 * @index: index of phandle to parse clock out of. If index < 0, @name is used
4759 * @name: clock name to find and parse. If name is NULL, the index is used
4760 * @out_args: Result of parsing the clock specifier
4762 * Parses a device node's "clocks" and "clock-names" properties to find the
4763 * phandle and cells for the index or name that is desired. The resulting clock
4764 * specifier is placed into @out_args, or an errno is returned when there's a
4765 * parsing error. The @index argument is ignored if @name is non-NULL.
4769 * phandle1: clock-controller@1 {
4770 * #clock-cells = <2>;
4773 * phandle2: clock-controller@2 {
4774 * #clock-cells = <1>;
4777 * clock-consumer@3 {
4778 * clocks = <&phandle1 1 2 &phandle2 3>;
4779 * clock-names = "name1", "name2";
4782 * To get a device_node for `clock-controller@2' node you may call this
4783 * function a few different ways:
4785 * of_parse_clkspec(clock-consumer@3, -1, "name2", &args);
4786 * of_parse_clkspec(clock-consumer@3, 1, NULL, &args);
4787 * of_parse_clkspec(clock-consumer@3, 1, "name2", &args);
4789 * Return: 0 upon successfully parsing the clock specifier. Otherwise, -ENOENT
4790 * if @name is NULL or -EINVAL if @name is non-NULL and it can't be found in
4791 * the "clock-names" property of @np.
4793 static int of_parse_clkspec(const struct device_node *np, int index,
4794 const char *name, struct of_phandle_args *out_args)
4798 /* Walk up the tree of devices looking for a clock property that matches */
4801 * For named clocks, first look up the name in the
4802 * "clock-names" property. If it cannot be found, then index
4803 * will be an error code and of_parse_phandle_with_args() will
4807 index = of_property_match_string(np, "clock-names", name);
4808 ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells",
4812 if (name && index >= 0)
4816 * No matching clock found on this node. If the parent node
4817 * has a "clock-ranges" property, then we can try one of its
4821 if (np && !of_get_property(np, "clock-ranges", NULL))
4829 static struct clk_hw *
4830 __of_clk_get_hw_from_provider(struct of_clk_provider *provider,
4831 struct of_phandle_args *clkspec)
4835 if (provider->get_hw)
4836 return provider->get_hw(clkspec, provider->data);
4838 clk = provider->get(clkspec, provider->data);
4840 return ERR_CAST(clk);
4841 return __clk_get_hw(clk);
4844 static struct clk_hw *
4845 of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
4847 struct of_clk_provider *provider;
4848 struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER);
4851 return ERR_PTR(-EINVAL);
4853 mutex_lock(&of_clk_mutex);
4854 list_for_each_entry(provider, &of_clk_providers, link) {
4855 if (provider->node == clkspec->np) {
4856 hw = __of_clk_get_hw_from_provider(provider, clkspec);
4861 mutex_unlock(&of_clk_mutex);
4867 * of_clk_get_from_provider() - Lookup a clock from a clock provider
4868 * @clkspec: pointer to a clock specifier data structure
4870 * This function looks up a struct clk from the registered list of clock
4871 * providers, an input is a clock specifier data structure as returned
4872 * from the of_parse_phandle_with_args() function call.
4874 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
4876 struct clk_hw *hw = of_clk_get_hw_from_clkspec(clkspec);
4878 return clk_hw_create_clk(NULL, hw, NULL, __func__);
4880 EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
4882 struct clk_hw *of_clk_get_hw(struct device_node *np, int index,
4887 struct of_phandle_args clkspec;
4889 ret = of_parse_clkspec(np, index, con_id, &clkspec);
4891 return ERR_PTR(ret);
4893 hw = of_clk_get_hw_from_clkspec(&clkspec);
4894 of_node_put(clkspec.np);
4899 static struct clk *__of_clk_get(struct device_node *np,
4900 int index, const char *dev_id,
4903 struct clk_hw *hw = of_clk_get_hw(np, index, con_id);
4905 return clk_hw_create_clk(NULL, hw, dev_id, con_id);
4908 struct clk *of_clk_get(struct device_node *np, int index)
4910 return __of_clk_get(np, index, np->full_name, NULL);
4912 EXPORT_SYMBOL(of_clk_get);
4915 * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
4916 * @np: pointer to clock consumer node
4917 * @name: name of consumer's clock input, or NULL for the first clock reference
4919 * This function parses the clocks and clock-names properties,
4920 * and uses them to look up the struct clk from the registered list of clock
4923 struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
4926 return ERR_PTR(-ENOENT);
4928 return __of_clk_get(np, 0, np->full_name, name);
4930 EXPORT_SYMBOL(of_clk_get_by_name);
4933 * of_clk_get_parent_count() - Count the number of clocks a device node has
4934 * @np: device node to count
4936 * Returns: The number of clocks that are possible parents of this node
4938 unsigned int of_clk_get_parent_count(const struct device_node *np)
4942 count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
4948 EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
4950 const char *of_clk_get_parent_name(const struct device_node *np, int index)
4952 struct of_phandle_args clkspec;
4953 struct property *prop;
4954 const char *clk_name;
4961 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
4966 index = clkspec.args_count ? clkspec.args[0] : 0;
4969 /* if there is an indices property, use it to transfer the index
4970 * specified into an array offset for the clock-output-names property.
4972 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
4979 /* We went off the end of 'clock-indices' without finding it */
4983 if (of_property_read_string_index(clkspec.np, "clock-output-names",
4987 * Best effort to get the name if the clock has been
4988 * registered with the framework. If the clock isn't
4989 * registered, we return the node name as the name of
4990 * the clock as long as #clock-cells = 0.
4992 clk = of_clk_get_from_provider(&clkspec);
4994 if (clkspec.args_count == 0)
4995 clk_name = clkspec.np->name;
4999 clk_name = __clk_get_name(clk);
5005 of_node_put(clkspec.np);
5008 EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
5011 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
5013 * @np: Device node pointer associated with clock provider
5014 * @parents: pointer to char array that hold the parents' names
5015 * @size: size of the @parents array
5017 * Return: number of parents for the clock node.
5019 int of_clk_parent_fill(struct device_node *np, const char **parents,
5024 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
5029 EXPORT_SYMBOL_GPL(of_clk_parent_fill);
5031 struct clock_provider {
5032 void (*clk_init_cb)(struct device_node *);
5033 struct device_node *np;
5034 struct list_head node;
5038 * This function looks for a parent clock. If there is one, then it
5039 * checks that the provider for this parent clock was initialized, in
5040 * this case the parent clock will be ready.
5042 static int parent_ready(struct device_node *np)
5047 struct clk *clk = of_clk_get(np, i);
5049 /* this parent is ready we can check the next one */
5056 /* at least one parent is not ready, we exit now */
5057 if (PTR_ERR(clk) == -EPROBE_DEFER)
5061 * Here we make assumption that the device tree is
5062 * written correctly. So an error means that there is
5063 * no more parent. As we didn't exit yet, then the
5064 * previous parent are ready. If there is no clock
5065 * parent, no need to wait for them, then we can
5066 * consider their absence as being ready
5073 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
5074 * @np: Device node pointer associated with clock provider
5075 * @index: clock index
5076 * @flags: pointer to top-level framework flags
5078 * Detects if the clock-critical property exists and, if so, sets the
5079 * corresponding CLK_IS_CRITICAL flag.
5081 * Do not use this function. It exists only for legacy Device Tree
5082 * bindings, such as the one-clock-per-node style that are outdated.
5083 * Those bindings typically put all clock data into .dts and the Linux
5084 * driver has no clock data, thus making it impossible to set this flag
5085 * correctly from the driver. Only those drivers may call
5086 * of_clk_detect_critical from their setup functions.
5088 * Return: error code or zero on success
5090 int of_clk_detect_critical(struct device_node *np, int index,
5091 unsigned long *flags)
5093 struct property *prop;
5100 of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
5102 *flags |= CLK_IS_CRITICAL;
5108 * of_clk_init() - Scan and init clock providers from the DT
5109 * @matches: array of compatible values and init functions for providers.
5111 * This function scans the device tree for matching clock providers
5112 * and calls their initialization functions. It also does it by trying
5113 * to follow the dependencies.
5115 void __init of_clk_init(const struct of_device_id *matches)
5117 const struct of_device_id *match;
5118 struct device_node *np;
5119 struct clock_provider *clk_provider, *next;
5122 LIST_HEAD(clk_provider_list);
5125 matches = &__clk_of_table;
5127 /* First prepare the list of the clocks providers */
5128 for_each_matching_node_and_match(np, matches, &match) {
5129 struct clock_provider *parent;
5131 if (!of_device_is_available(np))
5134 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
5136 list_for_each_entry_safe(clk_provider, next,
5137 &clk_provider_list, node) {
5138 list_del(&clk_provider->node);
5139 of_node_put(clk_provider->np);
5140 kfree(clk_provider);
5146 parent->clk_init_cb = match->data;
5147 parent->np = of_node_get(np);
5148 list_add_tail(&parent->node, &clk_provider_list);
5151 while (!list_empty(&clk_provider_list)) {
5152 is_init_done = false;
5153 list_for_each_entry_safe(clk_provider, next,
5154 &clk_provider_list, node) {
5155 if (force || parent_ready(clk_provider->np)) {
5157 /* Don't populate platform devices */
5158 of_node_set_flag(clk_provider->np,
5161 clk_provider->clk_init_cb(clk_provider->np);
5162 of_clk_set_defaults(clk_provider->np, true);
5164 list_del(&clk_provider->node);
5165 of_node_put(clk_provider->np);
5166 kfree(clk_provider);
5167 is_init_done = true;
5172 * We didn't manage to initialize any of the
5173 * remaining providers during the last loop, so now we
5174 * initialize all the remaining ones unconditionally
5175 * in case the clock parent was not mandatory