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);
117 return ret < 0 ? ret : 0;
120 static void clk_pm_runtime_put(struct clk_core *core)
122 if (!core->rpm_enabled)
125 pm_runtime_put_sync(core->dev);
129 static void clk_prepare_lock(void)
131 if (!mutex_trylock(&prepare_lock)) {
132 if (prepare_owner == current) {
136 mutex_lock(&prepare_lock);
138 WARN_ON_ONCE(prepare_owner != NULL);
139 WARN_ON_ONCE(prepare_refcnt != 0);
140 prepare_owner = current;
144 static void clk_prepare_unlock(void)
146 WARN_ON_ONCE(prepare_owner != current);
147 WARN_ON_ONCE(prepare_refcnt == 0);
149 if (--prepare_refcnt)
151 prepare_owner = NULL;
152 mutex_unlock(&prepare_lock);
155 static unsigned long clk_enable_lock(void)
156 __acquires(enable_lock)
161 * On UP systems, spin_trylock_irqsave() always returns true, even if
162 * we already hold the lock. So, in that case, we rely only on
163 * reference counting.
165 if (!IS_ENABLED(CONFIG_SMP) ||
166 !spin_trylock_irqsave(&enable_lock, flags)) {
167 if (enable_owner == current) {
169 __acquire(enable_lock);
170 if (!IS_ENABLED(CONFIG_SMP))
171 local_save_flags(flags);
174 spin_lock_irqsave(&enable_lock, flags);
176 WARN_ON_ONCE(enable_owner != NULL);
177 WARN_ON_ONCE(enable_refcnt != 0);
178 enable_owner = current;
183 static void clk_enable_unlock(unsigned long flags)
184 __releases(enable_lock)
186 WARN_ON_ONCE(enable_owner != current);
187 WARN_ON_ONCE(enable_refcnt == 0);
189 if (--enable_refcnt) {
190 __release(enable_lock);
194 spin_unlock_irqrestore(&enable_lock, flags);
197 static bool clk_core_rate_is_protected(struct clk_core *core)
199 return core->protect_count;
202 static bool clk_core_is_prepared(struct clk_core *core)
207 * .is_prepared is optional for clocks that can prepare
208 * fall back to software usage counter if it is missing
210 if (!core->ops->is_prepared)
211 return core->prepare_count;
213 if (!clk_pm_runtime_get(core)) {
214 ret = core->ops->is_prepared(core->hw);
215 clk_pm_runtime_put(core);
221 static bool clk_core_is_enabled(struct clk_core *core)
226 * .is_enabled is only mandatory for clocks that gate
227 * fall back to software usage counter if .is_enabled is missing
229 if (!core->ops->is_enabled)
230 return core->enable_count;
233 * Check if clock controller's device is runtime active before
234 * calling .is_enabled callback. If not, assume that clock is
235 * disabled, because we might be called from atomic context, from
236 * which pm_runtime_get() is not allowed.
237 * This function is called mainly from clk_disable_unused_subtree,
238 * which ensures proper runtime pm activation of controller before
239 * taking enable spinlock, but the below check is needed if one tries
240 * to call it from other places.
242 if (core->rpm_enabled) {
243 pm_runtime_get_noresume(core->dev);
244 if (!pm_runtime_active(core->dev)) {
250 ret = core->ops->is_enabled(core->hw);
252 if (core->rpm_enabled)
253 pm_runtime_put(core->dev);
258 /*** helper functions ***/
260 const char *__clk_get_name(const struct clk *clk)
262 return !clk ? NULL : clk->core->name;
264 EXPORT_SYMBOL_GPL(__clk_get_name);
266 const char *clk_hw_get_name(const struct clk_hw *hw)
268 return hw->core->name;
270 EXPORT_SYMBOL_GPL(clk_hw_get_name);
272 struct clk_hw *__clk_get_hw(struct clk *clk)
274 return !clk ? NULL : clk->core->hw;
276 EXPORT_SYMBOL_GPL(__clk_get_hw);
278 unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
280 return hw->core->num_parents;
282 EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
284 struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
286 return hw->core->parent ? hw->core->parent->hw : NULL;
288 EXPORT_SYMBOL_GPL(clk_hw_get_parent);
290 static struct clk_core *__clk_lookup_subtree(const char *name,
291 struct clk_core *core)
293 struct clk_core *child;
294 struct clk_core *ret;
296 if (!strcmp(core->name, name))
299 hlist_for_each_entry(child, &core->children, child_node) {
300 ret = __clk_lookup_subtree(name, child);
308 static struct clk_core *clk_core_lookup(const char *name)
310 struct clk_core *root_clk;
311 struct clk_core *ret;
316 /* search the 'proper' clk tree first */
317 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
318 ret = __clk_lookup_subtree(name, root_clk);
323 /* if not found, then search the orphan tree */
324 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
325 ret = __clk_lookup_subtree(name, root_clk);
334 static int of_parse_clkspec(const struct device_node *np, int index,
335 const char *name, struct of_phandle_args *out_args);
336 static struct clk_hw *
337 of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec);
339 static inline int of_parse_clkspec(const struct device_node *np, int index,
341 struct of_phandle_args *out_args)
345 static inline struct clk_hw *
346 of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
348 return ERR_PTR(-ENOENT);
353 * clk_core_get - Find the clk_core parent of a clk
354 * @core: clk to find parent of
355 * @p_index: parent index to search for
357 * This is the preferred method for clk providers to find the parent of a
358 * clk when that parent is external to the clk controller. The parent_names
359 * array is indexed and treated as a local name matching a string in the device
360 * node's 'clock-names' property or as the 'con_id' matching the device's
361 * dev_name() in a clk_lookup. This allows clk providers to use their own
362 * namespace instead of looking for a globally unique parent string.
364 * For example the following DT snippet would allow a clock registered by the
365 * clock-controller@c001 that has a clk_init_data::parent_data array
366 * with 'xtal' in the 'name' member to find the clock provided by the
367 * clock-controller@f00abcd without needing to get the globally unique name of
370 * parent: clock-controller@f00abcd {
371 * reg = <0xf00abcd 0xabcd>;
372 * #clock-cells = <0>;
375 * clock-controller@c001 {
376 * reg = <0xc001 0xf00d>;
377 * clocks = <&parent>;
378 * clock-names = "xtal";
379 * #clock-cells = <1>;
382 * Returns: -ENOENT when the provider can't be found or the clk doesn't
383 * exist in the provider or the name can't be found in the DT node or
384 * in a clkdev lookup. NULL when the provider knows about the clk but it
385 * isn't provided on this system.
386 * A valid clk_core pointer when the clk can be found in the provider.
388 static struct clk_core *clk_core_get(struct clk_core *core, u8 p_index)
390 const char *name = core->parents[p_index].fw_name;
391 int index = core->parents[p_index].index;
392 struct clk_hw *hw = ERR_PTR(-ENOENT);
393 struct device *dev = core->dev;
394 const char *dev_id = dev ? dev_name(dev) : NULL;
395 struct device_node *np = core->of_node;
396 struct of_phandle_args clkspec;
398 if (np && (name || index >= 0) &&
399 !of_parse_clkspec(np, index, name, &clkspec)) {
400 hw = of_clk_get_hw_from_clkspec(&clkspec);
401 of_node_put(clkspec.np);
404 * If the DT search above couldn't find the provider fallback to
405 * looking up via clkdev based clk_lookups.
407 hw = clk_find_hw(dev_id, name);
416 static void clk_core_fill_parent_index(struct clk_core *core, u8 index)
418 struct clk_parent_map *entry = &core->parents[index];
419 struct clk_core *parent = ERR_PTR(-ENOENT);
422 parent = entry->hw->core;
424 * We have a direct reference but it isn't registered yet?
425 * Orphan it and let clk_reparent() update the orphan status
426 * when the parent is registered.
429 parent = ERR_PTR(-EPROBE_DEFER);
431 parent = clk_core_get(core, index);
432 if (PTR_ERR(parent) == -ENOENT && entry->name)
433 parent = clk_core_lookup(entry->name);
436 /* Only cache it if it's not an error */
438 entry->core = parent;
441 static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
444 if (!core || index >= core->num_parents || !core->parents)
447 if (!core->parents[index].core)
448 clk_core_fill_parent_index(core, index);
450 return core->parents[index].core;
454 clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
456 struct clk_core *parent;
458 parent = clk_core_get_parent_by_index(hw->core, index);
460 return !parent ? NULL : parent->hw;
462 EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
464 unsigned int __clk_get_enable_count(struct clk *clk)
466 return !clk ? 0 : clk->core->enable_count;
469 static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
474 if (!core->num_parents || core->parent)
478 * Clk must have a parent because num_parents > 0 but the parent isn't
479 * known yet. Best to return 0 as the rate of this clk until we can
480 * properly recalc the rate based on the parent's rate.
485 unsigned long clk_hw_get_rate(const struct clk_hw *hw)
487 return clk_core_get_rate_nolock(hw->core);
489 EXPORT_SYMBOL_GPL(clk_hw_get_rate);
491 static unsigned long clk_core_get_accuracy_no_lock(struct clk_core *core)
496 return core->accuracy;
499 unsigned long __clk_get_flags(struct clk *clk)
501 return !clk ? 0 : clk->core->flags;
503 EXPORT_SYMBOL_GPL(__clk_get_flags);
505 unsigned long clk_hw_get_flags(const struct clk_hw *hw)
507 return hw->core->flags;
509 EXPORT_SYMBOL_GPL(clk_hw_get_flags);
511 bool clk_hw_is_prepared(const struct clk_hw *hw)
513 return clk_core_is_prepared(hw->core);
515 EXPORT_SYMBOL_GPL(clk_hw_is_prepared);
517 bool clk_hw_rate_is_protected(const struct clk_hw *hw)
519 return clk_core_rate_is_protected(hw->core);
521 EXPORT_SYMBOL_GPL(clk_hw_rate_is_protected);
523 bool clk_hw_is_enabled(const struct clk_hw *hw)
525 return clk_core_is_enabled(hw->core);
527 EXPORT_SYMBOL_GPL(clk_hw_is_enabled);
529 bool __clk_is_enabled(struct clk *clk)
534 return clk_core_is_enabled(clk->core);
536 EXPORT_SYMBOL_GPL(__clk_is_enabled);
538 static bool mux_is_better_rate(unsigned long rate, unsigned long now,
539 unsigned long best, unsigned long flags)
541 if (flags & CLK_MUX_ROUND_CLOSEST)
542 return abs(now - rate) < abs(best - rate);
544 return now <= rate && now > best;
547 int clk_mux_determine_rate_flags(struct clk_hw *hw,
548 struct clk_rate_request *req,
551 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
552 int i, num_parents, ret;
553 unsigned long best = 0;
554 struct clk_rate_request parent_req = *req;
556 /* if NO_REPARENT flag set, pass through to current parent */
557 if (core->flags & CLK_SET_RATE_NO_REPARENT) {
558 parent = core->parent;
559 if (core->flags & CLK_SET_RATE_PARENT) {
560 ret = __clk_determine_rate(parent ? parent->hw : NULL,
565 best = parent_req.rate;
567 best = clk_core_get_rate_nolock(parent);
569 best = clk_core_get_rate_nolock(core);
575 /* find the parent that can provide the fastest rate <= rate */
576 num_parents = core->num_parents;
577 for (i = 0; i < num_parents; i++) {
578 parent = clk_core_get_parent_by_index(core, i);
582 if (core->flags & CLK_SET_RATE_PARENT) {
584 ret = __clk_determine_rate(parent->hw, &parent_req);
588 parent_req.rate = clk_core_get_rate_nolock(parent);
591 if (mux_is_better_rate(req->rate, parent_req.rate,
593 best_parent = parent;
594 best = parent_req.rate;
603 req->best_parent_hw = best_parent->hw;
604 req->best_parent_rate = best;
609 EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);
611 struct clk *__clk_lookup(const char *name)
613 struct clk_core *core = clk_core_lookup(name);
615 return !core ? NULL : core->hw->clk;
618 static void clk_core_get_boundaries(struct clk_core *core,
619 unsigned long *min_rate,
620 unsigned long *max_rate)
622 struct clk *clk_user;
624 lockdep_assert_held(&prepare_lock);
626 *min_rate = core->min_rate;
627 *max_rate = core->max_rate;
629 hlist_for_each_entry(clk_user, &core->clks, clks_node)
630 *min_rate = max(*min_rate, clk_user->min_rate);
632 hlist_for_each_entry(clk_user, &core->clks, clks_node)
633 *max_rate = min(*max_rate, clk_user->max_rate);
636 void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
637 unsigned long max_rate)
639 hw->core->min_rate = min_rate;
640 hw->core->max_rate = max_rate;
642 EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
645 * __clk_mux_determine_rate - clk_ops::determine_rate implementation for a mux type clk
646 * @hw: mux type clk to determine rate on
647 * @req: rate request, also used to return preferred parent and frequencies
649 * Helper for finding best parent to provide a given frequency. This can be used
650 * directly as a determine_rate callback (e.g. for a mux), or from a more
651 * complex clock that may combine a mux with other operations.
653 * Returns: 0 on success, -EERROR value on error
655 int __clk_mux_determine_rate(struct clk_hw *hw,
656 struct clk_rate_request *req)
658 return clk_mux_determine_rate_flags(hw, req, 0);
660 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
662 int __clk_mux_determine_rate_closest(struct clk_hw *hw,
663 struct clk_rate_request *req)
665 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
667 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
671 static void clk_core_rate_unprotect(struct clk_core *core)
673 lockdep_assert_held(&prepare_lock);
678 if (WARN(core->protect_count == 0,
679 "%s already unprotected\n", core->name))
682 if (--core->protect_count > 0)
685 clk_core_rate_unprotect(core->parent);
688 static int clk_core_rate_nuke_protect(struct clk_core *core)
692 lockdep_assert_held(&prepare_lock);
697 if (core->protect_count == 0)
700 ret = core->protect_count;
701 core->protect_count = 1;
702 clk_core_rate_unprotect(core);
708 * clk_rate_exclusive_put - release exclusivity over clock rate control
709 * @clk: the clk over which the exclusivity is released
711 * clk_rate_exclusive_put() completes a critical section during which a clock
712 * consumer cannot tolerate any other consumer making any operation on the
713 * clock which could result in a rate change or rate glitch. Exclusive clocks
714 * cannot have their rate changed, either directly or indirectly due to changes
715 * further up the parent chain of clocks. As a result, clocks up parent chain
716 * also get under exclusive control of the calling consumer.
718 * If exlusivity is claimed more than once on clock, even by the same consumer,
719 * the rate effectively gets locked as exclusivity can't be preempted.
721 * Calls to clk_rate_exclusive_put() must be balanced with calls to
722 * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
725 void clk_rate_exclusive_put(struct clk *clk)
733 * if there is something wrong with this consumer protect count, stop
734 * here before messing with the provider
736 if (WARN_ON(clk->exclusive_count <= 0))
739 clk_core_rate_unprotect(clk->core);
740 clk->exclusive_count--;
742 clk_prepare_unlock();
744 EXPORT_SYMBOL_GPL(clk_rate_exclusive_put);
746 static void clk_core_rate_protect(struct clk_core *core)
748 lockdep_assert_held(&prepare_lock);
753 if (core->protect_count == 0)
754 clk_core_rate_protect(core->parent);
756 core->protect_count++;
759 static void clk_core_rate_restore_protect(struct clk_core *core, int count)
761 lockdep_assert_held(&prepare_lock);
769 clk_core_rate_protect(core);
770 core->protect_count = count;
774 * clk_rate_exclusive_get - get exclusivity over the clk rate control
775 * @clk: the clk over which the exclusity of rate control is requested
777 * clk_rate_exclusive_get() begins a critical section during which a clock
778 * consumer cannot tolerate any other consumer making any operation on the
779 * clock which could result in a rate change or rate glitch. Exclusive clocks
780 * cannot have their rate changed, either directly or indirectly due to changes
781 * further up the parent chain of clocks. As a result, clocks up parent chain
782 * also get under exclusive control of the calling consumer.
784 * If exlusivity is claimed more than once on clock, even by the same consumer,
785 * the rate effectively gets locked as exclusivity can't be preempted.
787 * Calls to clk_rate_exclusive_get() should be balanced with calls to
788 * clk_rate_exclusive_put(). Calls to this function may sleep.
789 * Returns 0 on success, -EERROR otherwise
791 int clk_rate_exclusive_get(struct clk *clk)
797 clk_core_rate_protect(clk->core);
798 clk->exclusive_count++;
799 clk_prepare_unlock();
803 EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
805 static void clk_core_unprepare(struct clk_core *core)
807 lockdep_assert_held(&prepare_lock);
812 if (WARN(core->prepare_count == 0,
813 "%s already unprepared\n", core->name))
816 if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL,
817 "Unpreparing critical %s\n", core->name))
820 if (core->flags & CLK_SET_RATE_GATE)
821 clk_core_rate_unprotect(core);
823 if (--core->prepare_count > 0)
826 WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);
828 trace_clk_unprepare(core);
830 if (core->ops->unprepare)
831 core->ops->unprepare(core->hw);
833 clk_pm_runtime_put(core);
835 trace_clk_unprepare_complete(core);
836 clk_core_unprepare(core->parent);
839 static void clk_core_unprepare_lock(struct clk_core *core)
842 clk_core_unprepare(core);
843 clk_prepare_unlock();
847 * clk_unprepare - undo preparation of a clock source
848 * @clk: the clk being unprepared
850 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
851 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
852 * if the operation may sleep. One example is a clk which is accessed over
853 * I2c. In the complex case a clk gate operation may require a fast and a slow
854 * part. It is this reason that clk_unprepare and clk_disable are not mutually
855 * exclusive. In fact clk_disable must be called before clk_unprepare.
857 void clk_unprepare(struct clk *clk)
859 if (IS_ERR_OR_NULL(clk))
862 clk_core_unprepare_lock(clk->core);
864 EXPORT_SYMBOL_GPL(clk_unprepare);
866 static int clk_core_prepare(struct clk_core *core)
870 lockdep_assert_held(&prepare_lock);
875 if (core->prepare_count == 0) {
876 ret = clk_pm_runtime_get(core);
880 ret = clk_core_prepare(core->parent);
884 trace_clk_prepare(core);
886 if (core->ops->prepare)
887 ret = core->ops->prepare(core->hw);
889 trace_clk_prepare_complete(core);
895 core->prepare_count++;
898 * CLK_SET_RATE_GATE is a special case of clock protection
899 * Instead of a consumer claiming exclusive rate control, it is
900 * actually the provider which prevents any consumer from making any
901 * operation which could result in a rate change or rate glitch while
902 * the clock is prepared.
904 if (core->flags & CLK_SET_RATE_GATE)
905 clk_core_rate_protect(core);
909 clk_core_unprepare(core->parent);
911 clk_pm_runtime_put(core);
915 static int clk_core_prepare_lock(struct clk_core *core)
920 ret = clk_core_prepare(core);
921 clk_prepare_unlock();
927 * clk_prepare - prepare a clock source
928 * @clk: the clk being prepared
930 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
931 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
932 * operation may sleep. One example is a clk which is accessed over I2c. In
933 * the complex case a clk ungate operation may require a fast and a slow part.
934 * It is this reason that clk_prepare and clk_enable are not mutually
935 * exclusive. In fact clk_prepare must be called before clk_enable.
936 * Returns 0 on success, -EERROR otherwise.
938 int clk_prepare(struct clk *clk)
943 return clk_core_prepare_lock(clk->core);
945 EXPORT_SYMBOL_GPL(clk_prepare);
947 static void clk_core_disable(struct clk_core *core)
949 lockdep_assert_held(&enable_lock);
954 if (WARN(core->enable_count == 0, "%s already disabled\n", core->name))
957 if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL,
958 "Disabling critical %s\n", core->name))
961 if (--core->enable_count > 0)
964 trace_clk_disable_rcuidle(core);
966 if (core->ops->disable)
967 core->ops->disable(core->hw);
969 trace_clk_disable_complete_rcuidle(core);
971 clk_core_disable(core->parent);
974 static void clk_core_disable_lock(struct clk_core *core)
978 flags = clk_enable_lock();
979 clk_core_disable(core);
980 clk_enable_unlock(flags);
984 * clk_disable - gate a clock
985 * @clk: the clk being gated
987 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
988 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
989 * clk if the operation is fast and will never sleep. One example is a
990 * SoC-internal clk which is controlled via simple register writes. In the
991 * complex case a clk gate operation may require a fast and a slow part. It is
992 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
993 * In fact clk_disable must be called before clk_unprepare.
995 void clk_disable(struct clk *clk)
997 if (IS_ERR_OR_NULL(clk))
1000 clk_core_disable_lock(clk->core);
1002 EXPORT_SYMBOL_GPL(clk_disable);
1004 static int clk_core_enable(struct clk_core *core)
1008 lockdep_assert_held(&enable_lock);
1013 if (WARN(core->prepare_count == 0,
1014 "Enabling unprepared %s\n", core->name))
1017 if (core->enable_count == 0) {
1018 ret = clk_core_enable(core->parent);
1023 trace_clk_enable_rcuidle(core);
1025 if (core->ops->enable)
1026 ret = core->ops->enable(core->hw);
1028 trace_clk_enable_complete_rcuidle(core);
1031 clk_core_disable(core->parent);
1036 core->enable_count++;
1040 static int clk_core_enable_lock(struct clk_core *core)
1042 unsigned long flags;
1045 flags = clk_enable_lock();
1046 ret = clk_core_enable(core);
1047 clk_enable_unlock(flags);
1053 * clk_gate_restore_context - restore context for poweroff
1054 * @hw: the clk_hw pointer of clock whose state is to be restored
1056 * The clock gate restore context function enables or disables
1057 * the gate clocks based on the enable_count. This is done in cases
1058 * where the clock context is lost and based on the enable_count
1059 * the clock either needs to be enabled/disabled. This
1060 * helps restore the state of gate clocks.
1062 void clk_gate_restore_context(struct clk_hw *hw)
1064 struct clk_core *core = hw->core;
1066 if (core->enable_count)
1067 core->ops->enable(hw);
1069 core->ops->disable(hw);
1071 EXPORT_SYMBOL_GPL(clk_gate_restore_context);
1073 static int clk_core_save_context(struct clk_core *core)
1075 struct clk_core *child;
1078 hlist_for_each_entry(child, &core->children, child_node) {
1079 ret = clk_core_save_context(child);
1084 if (core->ops && core->ops->save_context)
1085 ret = core->ops->save_context(core->hw);
1090 static void clk_core_restore_context(struct clk_core *core)
1092 struct clk_core *child;
1094 if (core->ops && core->ops->restore_context)
1095 core->ops->restore_context(core->hw);
1097 hlist_for_each_entry(child, &core->children, child_node)
1098 clk_core_restore_context(child);
1102 * clk_save_context - save clock context for poweroff
1104 * Saves the context of the clock register for powerstates in which the
1105 * contents of the registers will be lost. Occurs deep within the suspend
1106 * code. Returns 0 on success.
1108 int clk_save_context(void)
1110 struct clk_core *clk;
1113 hlist_for_each_entry(clk, &clk_root_list, child_node) {
1114 ret = clk_core_save_context(clk);
1119 hlist_for_each_entry(clk, &clk_orphan_list, child_node) {
1120 ret = clk_core_save_context(clk);
1127 EXPORT_SYMBOL_GPL(clk_save_context);
1130 * clk_restore_context - restore clock context after poweroff
1132 * Restore the saved clock context upon resume.
1135 void clk_restore_context(void)
1137 struct clk_core *core;
1139 hlist_for_each_entry(core, &clk_root_list, child_node)
1140 clk_core_restore_context(core);
1142 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1143 clk_core_restore_context(core);
1145 EXPORT_SYMBOL_GPL(clk_restore_context);
1148 * clk_enable - ungate a clock
1149 * @clk: the clk being ungated
1151 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
1152 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
1153 * if the operation will never sleep. One example is a SoC-internal clk which
1154 * is controlled via simple register writes. In the complex case a clk ungate
1155 * operation may require a fast and a slow part. It is this reason that
1156 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
1157 * must be called before clk_enable. Returns 0 on success, -EERROR
1160 int clk_enable(struct clk *clk)
1165 return clk_core_enable_lock(clk->core);
1167 EXPORT_SYMBOL_GPL(clk_enable);
1169 static int clk_core_prepare_enable(struct clk_core *core)
1173 ret = clk_core_prepare_lock(core);
1177 ret = clk_core_enable_lock(core);
1179 clk_core_unprepare_lock(core);
1184 static void clk_core_disable_unprepare(struct clk_core *core)
1186 clk_core_disable_lock(core);
1187 clk_core_unprepare_lock(core);
1190 static void __init clk_unprepare_unused_subtree(struct clk_core *core)
1192 struct clk_core *child;
1194 lockdep_assert_held(&prepare_lock);
1196 hlist_for_each_entry(child, &core->children, child_node)
1197 clk_unprepare_unused_subtree(child);
1199 if (core->prepare_count)
1202 if (core->flags & CLK_IGNORE_UNUSED)
1205 if (clk_pm_runtime_get(core))
1208 if (clk_core_is_prepared(core)) {
1209 trace_clk_unprepare(core);
1210 if (core->ops->unprepare_unused)
1211 core->ops->unprepare_unused(core->hw);
1212 else if (core->ops->unprepare)
1213 core->ops->unprepare(core->hw);
1214 trace_clk_unprepare_complete(core);
1217 clk_pm_runtime_put(core);
1220 static void __init clk_disable_unused_subtree(struct clk_core *core)
1222 struct clk_core *child;
1223 unsigned long flags;
1225 lockdep_assert_held(&prepare_lock);
1227 hlist_for_each_entry(child, &core->children, child_node)
1228 clk_disable_unused_subtree(child);
1230 if (core->flags & CLK_OPS_PARENT_ENABLE)
1231 clk_core_prepare_enable(core->parent);
1233 if (clk_pm_runtime_get(core))
1236 flags = clk_enable_lock();
1238 if (core->enable_count)
1241 if (core->flags & CLK_IGNORE_UNUSED)
1245 * some gate clocks have special needs during the disable-unused
1246 * sequence. call .disable_unused if available, otherwise fall
1249 if (clk_core_is_enabled(core)) {
1250 trace_clk_disable(core);
1251 if (core->ops->disable_unused)
1252 core->ops->disable_unused(core->hw);
1253 else if (core->ops->disable)
1254 core->ops->disable(core->hw);
1255 trace_clk_disable_complete(core);
1259 clk_enable_unlock(flags);
1260 clk_pm_runtime_put(core);
1262 if (core->flags & CLK_OPS_PARENT_ENABLE)
1263 clk_core_disable_unprepare(core->parent);
1266 static bool clk_ignore_unused __initdata;
1267 static int __init clk_ignore_unused_setup(char *__unused)
1269 clk_ignore_unused = true;
1272 __setup("clk_ignore_unused", clk_ignore_unused_setup);
1274 static int __init clk_disable_unused(void)
1276 struct clk_core *core;
1278 if (clk_ignore_unused) {
1279 pr_warn("clk: Not disabling unused clocks\n");
1285 hlist_for_each_entry(core, &clk_root_list, child_node)
1286 clk_disable_unused_subtree(core);
1288 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1289 clk_disable_unused_subtree(core);
1291 hlist_for_each_entry(core, &clk_root_list, child_node)
1292 clk_unprepare_unused_subtree(core);
1294 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1295 clk_unprepare_unused_subtree(core);
1297 clk_prepare_unlock();
1301 late_initcall_sync(clk_disable_unused);
1303 static int clk_core_determine_round_nolock(struct clk_core *core,
1304 struct clk_rate_request *req)
1308 lockdep_assert_held(&prepare_lock);
1314 * At this point, core protection will be disabled if
1315 * - if the provider is not protected at all
1316 * - if the calling consumer is the only one which has exclusivity
1319 if (clk_core_rate_is_protected(core)) {
1320 req->rate = core->rate;
1321 } else if (core->ops->determine_rate) {
1322 return core->ops->determine_rate(core->hw, req);
1323 } else if (core->ops->round_rate) {
1324 rate = core->ops->round_rate(core->hw, req->rate,
1325 &req->best_parent_rate);
1337 static void clk_core_init_rate_req(struct clk_core * const core,
1338 struct clk_rate_request *req)
1340 struct clk_core *parent;
1342 if (WARN_ON(!core || !req))
1345 parent = core->parent;
1347 req->best_parent_hw = parent->hw;
1348 req->best_parent_rate = parent->rate;
1350 req->best_parent_hw = NULL;
1351 req->best_parent_rate = 0;
1355 static bool clk_core_can_round(struct clk_core * const core)
1357 return core->ops->determine_rate || core->ops->round_rate;
1360 static int clk_core_round_rate_nolock(struct clk_core *core,
1361 struct clk_rate_request *req)
1363 lockdep_assert_held(&prepare_lock);
1370 clk_core_init_rate_req(core, req);
1372 if (clk_core_can_round(core))
1373 return clk_core_determine_round_nolock(core, req);
1374 else if (core->flags & CLK_SET_RATE_PARENT)
1375 return clk_core_round_rate_nolock(core->parent, req);
1377 req->rate = core->rate;
1382 * __clk_determine_rate - get the closest rate actually supported by a clock
1383 * @hw: determine the rate of this clock
1384 * @req: target rate request
1386 * Useful for clk_ops such as .set_rate and .determine_rate.
1388 int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
1395 return clk_core_round_rate_nolock(hw->core, req);
1397 EXPORT_SYMBOL_GPL(__clk_determine_rate);
1399 unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
1402 struct clk_rate_request req;
1404 clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate);
1407 ret = clk_core_round_rate_nolock(hw->core, &req);
1413 EXPORT_SYMBOL_GPL(clk_hw_round_rate);
1416 * clk_round_rate - round the given rate for a clk
1417 * @clk: the clk for which we are rounding a rate
1418 * @rate: the rate which is to be rounded
1420 * Takes in a rate as input and rounds it to a rate that the clk can actually
1421 * use which is then returned. If clk doesn't support round_rate operation
1422 * then the parent rate is returned.
1424 long clk_round_rate(struct clk *clk, unsigned long rate)
1426 struct clk_rate_request req;
1434 if (clk->exclusive_count)
1435 clk_core_rate_unprotect(clk->core);
1437 clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
1440 ret = clk_core_round_rate_nolock(clk->core, &req);
1442 if (clk->exclusive_count)
1443 clk_core_rate_protect(clk->core);
1445 clk_prepare_unlock();
1452 EXPORT_SYMBOL_GPL(clk_round_rate);
1455 * __clk_notify - call clk notifier chain
1456 * @core: clk that is changing rate
1457 * @msg: clk notifier type (see include/linux/clk.h)
1458 * @old_rate: old clk rate
1459 * @new_rate: new clk rate
1461 * Triggers a notifier call chain on the clk rate-change notification
1462 * for 'clk'. Passes a pointer to the struct clk and the previous
1463 * and current rates to the notifier callback. Intended to be called by
1464 * internal clock code only. Returns NOTIFY_DONE from the last driver
1465 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1466 * a driver returns that.
1468 static int __clk_notify(struct clk_core *core, unsigned long msg,
1469 unsigned long old_rate, unsigned long new_rate)
1471 struct clk_notifier *cn;
1472 struct clk_notifier_data cnd;
1473 int ret = NOTIFY_DONE;
1475 cnd.old_rate = old_rate;
1476 cnd.new_rate = new_rate;
1478 list_for_each_entry(cn, &clk_notifier_list, node) {
1479 if (cn->clk->core == core) {
1481 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
1483 if (ret & NOTIFY_STOP_MASK)
1492 * __clk_recalc_accuracies
1493 * @core: first clk in the subtree
1495 * Walks the subtree of clks starting with clk and recalculates accuracies as
1496 * it goes. Note that if a clk does not implement the .recalc_accuracy
1497 * callback then it is assumed that the clock will take on the accuracy of its
1500 static void __clk_recalc_accuracies(struct clk_core *core)
1502 unsigned long parent_accuracy = 0;
1503 struct clk_core *child;
1505 lockdep_assert_held(&prepare_lock);
1508 parent_accuracy = core->parent->accuracy;
1510 if (core->ops->recalc_accuracy)
1511 core->accuracy = core->ops->recalc_accuracy(core->hw,
1514 core->accuracy = parent_accuracy;
1516 hlist_for_each_entry(child, &core->children, child_node)
1517 __clk_recalc_accuracies(child);
1520 static long clk_core_get_accuracy_recalc(struct clk_core *core)
1522 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
1523 __clk_recalc_accuracies(core);
1525 return clk_core_get_accuracy_no_lock(core);
1529 * clk_get_accuracy - return the accuracy of clk
1530 * @clk: the clk whose accuracy is being returned
1532 * Simply returns the cached accuracy of the clk, unless
1533 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1535 * If clk is NULL then returns 0.
1537 long clk_get_accuracy(struct clk *clk)
1545 accuracy = clk_core_get_accuracy_recalc(clk->core);
1546 clk_prepare_unlock();
1550 EXPORT_SYMBOL_GPL(clk_get_accuracy);
1552 static unsigned long clk_recalc(struct clk_core *core,
1553 unsigned long parent_rate)
1555 unsigned long rate = parent_rate;
1557 if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
1558 rate = core->ops->recalc_rate(core->hw, parent_rate);
1559 clk_pm_runtime_put(core);
1565 * __clk_recalc_rates
1566 * @core: first clk in the subtree
1567 * @msg: notification type (see include/linux/clk.h)
1569 * Walks the subtree of clks starting with clk and recalculates rates as it
1570 * goes. Note that if a clk does not implement the .recalc_rate callback then
1571 * it is assumed that the clock will take on the rate of its parent.
1573 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1576 static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
1578 unsigned long old_rate;
1579 unsigned long parent_rate = 0;
1580 struct clk_core *child;
1582 lockdep_assert_held(&prepare_lock);
1584 old_rate = core->rate;
1587 parent_rate = core->parent->rate;
1589 core->rate = clk_recalc(core, parent_rate);
1592 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1593 * & ABORT_RATE_CHANGE notifiers
1595 if (core->notifier_count && msg)
1596 __clk_notify(core, msg, old_rate, core->rate);
1598 hlist_for_each_entry(child, &core->children, child_node)
1599 __clk_recalc_rates(child, msg);
1602 static unsigned long clk_core_get_rate_recalc(struct clk_core *core)
1604 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1605 __clk_recalc_rates(core, 0);
1607 return clk_core_get_rate_nolock(core);
1611 * clk_get_rate - return the rate of clk
1612 * @clk: the clk whose rate is being returned
1614 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1615 * is set, which means a recalc_rate will be issued.
1616 * If clk is NULL then returns 0.
1618 unsigned long clk_get_rate(struct clk *clk)
1626 rate = clk_core_get_rate_recalc(clk->core);
1627 clk_prepare_unlock();
1631 EXPORT_SYMBOL_GPL(clk_get_rate);
1633 static int clk_fetch_parent_index(struct clk_core *core,
1634 struct clk_core *parent)
1641 for (i = 0; i < core->num_parents; i++) {
1642 /* Found it first try! */
1643 if (core->parents[i].core == parent)
1646 /* Something else is here, so keep looking */
1647 if (core->parents[i].core)
1650 /* Maybe core hasn't been cached but the hw is all we know? */
1651 if (core->parents[i].hw) {
1652 if (core->parents[i].hw == parent->hw)
1655 /* Didn't match, but we're expecting a clk_hw */
1659 /* Maybe it hasn't been cached (clk_set_parent() path) */
1660 if (parent == clk_core_get(core, i))
1663 /* Fallback to comparing globally unique names */
1664 if (core->parents[i].name &&
1665 !strcmp(parent->name, core->parents[i].name))
1669 if (i == core->num_parents)
1672 core->parents[i].core = parent;
1677 * clk_hw_get_parent_index - return the index of the parent clock
1678 * @hw: clk_hw associated with the clk being consumed
1680 * Fetches and returns the index of parent clock. Returns -EINVAL if the given
1681 * clock does not have a current parent.
1683 int clk_hw_get_parent_index(struct clk_hw *hw)
1685 struct clk_hw *parent = clk_hw_get_parent(hw);
1687 if (WARN_ON(parent == NULL))
1690 return clk_fetch_parent_index(hw->core, parent->core);
1692 EXPORT_SYMBOL_GPL(clk_hw_get_parent_index);
1695 * Update the orphan status of @core and all its children.
1697 static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
1699 struct clk_core *child;
1701 core->orphan = is_orphan;
1703 hlist_for_each_entry(child, &core->children, child_node)
1704 clk_core_update_orphan_status(child, is_orphan);
1707 static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1709 bool was_orphan = core->orphan;
1711 hlist_del(&core->child_node);
1714 bool becomes_orphan = new_parent->orphan;
1716 /* avoid duplicate POST_RATE_CHANGE notifications */
1717 if (new_parent->new_child == core)
1718 new_parent->new_child = NULL;
1720 hlist_add_head(&core->child_node, &new_parent->children);
1722 if (was_orphan != becomes_orphan)
1723 clk_core_update_orphan_status(core, becomes_orphan);
1725 hlist_add_head(&core->child_node, &clk_orphan_list);
1727 clk_core_update_orphan_status(core, true);
1730 core->parent = new_parent;
1733 static struct clk_core *__clk_set_parent_before(struct clk_core *core,
1734 struct clk_core *parent)
1736 unsigned long flags;
1737 struct clk_core *old_parent = core->parent;
1740 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
1742 * 2. Migrate prepare state between parents and prevent race with
1745 * If the clock is not prepared, then a race with
1746 * clk_enable/disable() is impossible since we already have the
1747 * prepare lock (future calls to clk_enable() need to be preceded by
1750 * If the clock is prepared, migrate the prepared state to the new
1751 * parent and also protect against a race with clk_enable() by
1752 * forcing the clock and the new parent on. This ensures that all
1753 * future calls to clk_enable() are practically NOPs with respect to
1754 * hardware and software states.
1756 * See also: Comment for clk_set_parent() below.
1759 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
1760 if (core->flags & CLK_OPS_PARENT_ENABLE) {
1761 clk_core_prepare_enable(old_parent);
1762 clk_core_prepare_enable(parent);
1765 /* migrate prepare count if > 0 */
1766 if (core->prepare_count) {
1767 clk_core_prepare_enable(parent);
1768 clk_core_enable_lock(core);
1771 /* update the clk tree topology */
1772 flags = clk_enable_lock();
1773 clk_reparent(core, parent);
1774 clk_enable_unlock(flags);
1779 static void __clk_set_parent_after(struct clk_core *core,
1780 struct clk_core *parent,
1781 struct clk_core *old_parent)
1784 * Finish the migration of prepare state and undo the changes done
1785 * for preventing a race with clk_enable().
1787 if (core->prepare_count) {
1788 clk_core_disable_lock(core);
1789 clk_core_disable_unprepare(old_parent);
1792 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
1793 if (core->flags & CLK_OPS_PARENT_ENABLE) {
1794 clk_core_disable_unprepare(parent);
1795 clk_core_disable_unprepare(old_parent);
1799 static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
1802 unsigned long flags;
1804 struct clk_core *old_parent;
1806 old_parent = __clk_set_parent_before(core, parent);
1808 trace_clk_set_parent(core, parent);
1810 /* change clock input source */
1811 if (parent && core->ops->set_parent)
1812 ret = core->ops->set_parent(core->hw, p_index);
1814 trace_clk_set_parent_complete(core, parent);
1817 flags = clk_enable_lock();
1818 clk_reparent(core, old_parent);
1819 clk_enable_unlock(flags);
1820 __clk_set_parent_after(core, old_parent, parent);
1825 __clk_set_parent_after(core, parent, old_parent);
1831 * __clk_speculate_rates
1832 * @core: first clk in the subtree
1833 * @parent_rate: the "future" rate of clk's parent
1835 * Walks the subtree of clks starting with clk, speculating rates as it
1836 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1838 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1839 * pre-rate change notifications and returns early if no clks in the
1840 * subtree have subscribed to the notifications. Note that if a clk does not
1841 * implement the .recalc_rate callback then it is assumed that the clock will
1842 * take on the rate of its parent.
1844 static int __clk_speculate_rates(struct clk_core *core,
1845 unsigned long parent_rate)
1847 struct clk_core *child;
1848 unsigned long new_rate;
1849 int ret = NOTIFY_DONE;
1851 lockdep_assert_held(&prepare_lock);
1853 new_rate = clk_recalc(core, parent_rate);
1855 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1856 if (core->notifier_count)
1857 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
1859 if (ret & NOTIFY_STOP_MASK) {
1860 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1861 __func__, core->name, ret);
1865 hlist_for_each_entry(child, &core->children, child_node) {
1866 ret = __clk_speculate_rates(child, new_rate);
1867 if (ret & NOTIFY_STOP_MASK)
1875 static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
1876 struct clk_core *new_parent, u8 p_index)
1878 struct clk_core *child;
1880 core->new_rate = new_rate;
1881 core->new_parent = new_parent;
1882 core->new_parent_index = p_index;
1883 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1884 core->new_child = NULL;
1885 if (new_parent && new_parent != core->parent)
1886 new_parent->new_child = core;
1888 hlist_for_each_entry(child, &core->children, child_node) {
1889 child->new_rate = clk_recalc(child, new_rate);
1890 clk_calc_subtree(child, child->new_rate, NULL, 0);
1895 * calculate the new rates returning the topmost clock that has to be
1898 static struct clk_core *clk_calc_new_rates(struct clk_core *core,
1901 struct clk_core *top = core;
1902 struct clk_core *old_parent, *parent;
1903 unsigned long best_parent_rate = 0;
1904 unsigned long new_rate;
1905 unsigned long min_rate;
1906 unsigned long max_rate;
1911 if (IS_ERR_OR_NULL(core))
1914 /* save parent rate, if it exists */
1915 parent = old_parent = core->parent;
1917 best_parent_rate = parent->rate;
1919 clk_core_get_boundaries(core, &min_rate, &max_rate);
1921 /* find the closest rate and parent clk/rate */
1922 if (clk_core_can_round(core)) {
1923 struct clk_rate_request req;
1926 req.min_rate = min_rate;
1927 req.max_rate = max_rate;
1929 clk_core_init_rate_req(core, &req);
1931 ret = clk_core_determine_round_nolock(core, &req);
1935 best_parent_rate = req.best_parent_rate;
1936 new_rate = req.rate;
1937 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
1939 if (new_rate < min_rate || new_rate > max_rate)
1941 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
1942 /* pass-through clock without adjustable parent */
1943 core->new_rate = core->rate;
1946 /* pass-through clock with adjustable parent */
1947 top = clk_calc_new_rates(parent, rate);
1948 new_rate = parent->new_rate;
1952 /* some clocks must be gated to change parent */
1953 if (parent != old_parent &&
1954 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1955 pr_debug("%s: %s not gated but wants to reparent\n",
1956 __func__, core->name);
1960 /* try finding the new parent index */
1961 if (parent && core->num_parents > 1) {
1962 p_index = clk_fetch_parent_index(core, parent);
1964 pr_debug("%s: clk %s can not be parent of clk %s\n",
1965 __func__, parent->name, core->name);
1970 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
1971 best_parent_rate != parent->rate)
1972 top = clk_calc_new_rates(parent, best_parent_rate);
1975 clk_calc_subtree(core, new_rate, parent, p_index);
1981 * Notify about rate changes in a subtree. Always walk down the whole tree
1982 * so that in case of an error we can walk down the whole tree again and
1985 static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
1986 unsigned long event)
1988 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
1989 int ret = NOTIFY_DONE;
1991 if (core->rate == core->new_rate)
1994 if (core->notifier_count) {
1995 ret = __clk_notify(core, event, core->rate, core->new_rate);
1996 if (ret & NOTIFY_STOP_MASK)
2000 hlist_for_each_entry(child, &core->children, child_node) {
2001 /* Skip children who will be reparented to another clock */
2002 if (child->new_parent && child->new_parent != core)
2004 tmp_clk = clk_propagate_rate_change(child, event);
2009 /* handle the new child who might not be in core->children yet */
2010 if (core->new_child) {
2011 tmp_clk = clk_propagate_rate_change(core->new_child, event);
2020 * walk down a subtree and set the new rates notifying the rate
2023 static void clk_change_rate(struct clk_core *core)
2025 struct clk_core *child;
2026 struct hlist_node *tmp;
2027 unsigned long old_rate;
2028 unsigned long best_parent_rate = 0;
2029 bool skip_set_rate = false;
2030 struct clk_core *old_parent;
2031 struct clk_core *parent = NULL;
2033 old_rate = core->rate;
2035 if (core->new_parent) {
2036 parent = core->new_parent;
2037 best_parent_rate = core->new_parent->rate;
2038 } else if (core->parent) {
2039 parent = core->parent;
2040 best_parent_rate = core->parent->rate;
2043 if (clk_pm_runtime_get(core))
2046 if (core->flags & CLK_SET_RATE_UNGATE) {
2047 unsigned long flags;
2049 clk_core_prepare(core);
2050 flags = clk_enable_lock();
2051 clk_core_enable(core);
2052 clk_enable_unlock(flags);
2055 if (core->new_parent && core->new_parent != core->parent) {
2056 old_parent = __clk_set_parent_before(core, core->new_parent);
2057 trace_clk_set_parent(core, core->new_parent);
2059 if (core->ops->set_rate_and_parent) {
2060 skip_set_rate = true;
2061 core->ops->set_rate_and_parent(core->hw, core->new_rate,
2063 core->new_parent_index);
2064 } else if (core->ops->set_parent) {
2065 core->ops->set_parent(core->hw, core->new_parent_index);
2068 trace_clk_set_parent_complete(core, core->new_parent);
2069 __clk_set_parent_after(core, core->new_parent, old_parent);
2072 if (core->flags & CLK_OPS_PARENT_ENABLE)
2073 clk_core_prepare_enable(parent);
2075 trace_clk_set_rate(core, core->new_rate);
2077 if (!skip_set_rate && core->ops->set_rate)
2078 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
2080 trace_clk_set_rate_complete(core, core->new_rate);
2082 core->rate = clk_recalc(core, best_parent_rate);
2084 if (core->flags & CLK_SET_RATE_UNGATE) {
2085 unsigned long flags;
2087 flags = clk_enable_lock();
2088 clk_core_disable(core);
2089 clk_enable_unlock(flags);
2090 clk_core_unprepare(core);
2093 if (core->flags & CLK_OPS_PARENT_ENABLE)
2094 clk_core_disable_unprepare(parent);
2096 if (core->notifier_count && old_rate != core->rate)
2097 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
2099 if (core->flags & CLK_RECALC_NEW_RATES)
2100 (void)clk_calc_new_rates(core, core->new_rate);
2103 * Use safe iteration, as change_rate can actually swap parents
2104 * for certain clock types.
2106 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
2107 /* Skip children who will be reparented to another clock */
2108 if (child->new_parent && child->new_parent != core)
2110 clk_change_rate(child);
2113 /* handle the new child who might not be in core->children yet */
2114 if (core->new_child)
2115 clk_change_rate(core->new_child);
2117 clk_pm_runtime_put(core);
2120 static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
2121 unsigned long req_rate)
2124 struct clk_rate_request req;
2126 lockdep_assert_held(&prepare_lock);
2131 /* simulate what the rate would be if it could be freely set */
2132 cnt = clk_core_rate_nuke_protect(core);
2136 clk_core_get_boundaries(core, &req.min_rate, &req.max_rate);
2137 req.rate = req_rate;
2139 ret = clk_core_round_rate_nolock(core, &req);
2141 /* restore the protection */
2142 clk_core_rate_restore_protect(core, cnt);
2144 return ret ? 0 : req.rate;
2147 static int clk_core_set_rate_nolock(struct clk_core *core,
2148 unsigned long req_rate)
2150 struct clk_core *top, *fail_clk;
2157 rate = clk_core_req_round_rate_nolock(core, req_rate);
2159 /* bail early if nothing to do */
2160 if (rate == clk_core_get_rate_nolock(core))
2163 /* fail on a direct rate set of a protected provider */
2164 if (clk_core_rate_is_protected(core))
2167 /* calculate new rates and get the topmost changed clock */
2168 top = clk_calc_new_rates(core, req_rate);
2172 ret = clk_pm_runtime_get(core);
2176 /* notify that we are about to change rates */
2177 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
2179 pr_debug("%s: failed to set %s rate\n", __func__,
2181 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
2186 /* change the rates */
2187 clk_change_rate(top);
2189 core->req_rate = req_rate;
2191 clk_pm_runtime_put(core);
2197 * clk_set_rate - specify a new rate for clk
2198 * @clk: the clk whose rate is being changed
2199 * @rate: the new rate for clk
2201 * In the simplest case clk_set_rate will only adjust the rate of clk.
2203 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
2204 * propagate up to clk's parent; whether or not this happens depends on the
2205 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
2206 * after calling .round_rate then upstream parent propagation is ignored. If
2207 * *parent_rate comes back with a new rate for clk's parent then we propagate
2208 * up to clk's parent and set its rate. Upward propagation will continue
2209 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
2210 * .round_rate stops requesting changes to clk's parent_rate.
2212 * Rate changes are accomplished via tree traversal that also recalculates the
2213 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
2215 * Returns 0 on success, -EERROR otherwise.
2217 int clk_set_rate(struct clk *clk, unsigned long rate)
2224 /* prevent racing with updates to the clock topology */
2227 if (clk->exclusive_count)
2228 clk_core_rate_unprotect(clk->core);
2230 ret = clk_core_set_rate_nolock(clk->core, rate);
2232 if (clk->exclusive_count)
2233 clk_core_rate_protect(clk->core);
2235 clk_prepare_unlock();
2239 EXPORT_SYMBOL_GPL(clk_set_rate);
2242 * clk_set_rate_exclusive - specify a new rate and get exclusive control
2243 * @clk: the clk whose rate is being changed
2244 * @rate: the new rate for clk
2246 * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
2247 * within a critical section
2249 * This can be used initially to ensure that at least 1 consumer is
2250 * satisfied when several consumers are competing for exclusivity over the
2251 * same clock provider.
2253 * The exclusivity is not applied if setting the rate failed.
2255 * Calls to clk_rate_exclusive_get() should be balanced with calls to
2256 * clk_rate_exclusive_put().
2258 * Returns 0 on success, -EERROR otherwise.
2260 int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
2267 /* prevent racing with updates to the clock topology */
2271 * The temporary protection removal is not here, on purpose
2272 * This function is meant to be used instead of clk_rate_protect,
2273 * so before the consumer code path protect the clock provider
2276 ret = clk_core_set_rate_nolock(clk->core, rate);
2278 clk_core_rate_protect(clk->core);
2279 clk->exclusive_count++;
2282 clk_prepare_unlock();
2286 EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
2289 * clk_set_rate_range - set a rate range for a clock source
2290 * @clk: clock source
2291 * @min: desired minimum clock rate in Hz, inclusive
2292 * @max: desired maximum clock rate in Hz, inclusive
2294 * Returns success (0) or negative errno.
2296 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
2299 unsigned long old_min, old_max, rate;
2305 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
2306 __func__, clk->core->name, clk->dev_id, clk->con_id,
2313 if (clk->exclusive_count)
2314 clk_core_rate_unprotect(clk->core);
2316 /* Save the current values in case we need to rollback the change */
2317 old_min = clk->min_rate;
2318 old_max = clk->max_rate;
2319 clk->min_rate = min;
2320 clk->max_rate = max;
2322 rate = clk_core_get_rate_nolock(clk->core);
2323 if (rate < min || rate > max) {
2326 * We are in bit of trouble here, current rate is outside the
2327 * the requested range. We are going try to request appropriate
2328 * range boundary but there is a catch. It may fail for the
2329 * usual reason (clock broken, clock protected, etc) but also
2331 * - round_rate() was not favorable and fell on the wrong
2332 * side of the boundary
2333 * - the determine_rate() callback does not really check for
2334 * this corner case when determining the rate
2342 ret = clk_core_set_rate_nolock(clk->core, rate);
2344 /* rollback the changes */
2345 clk->min_rate = old_min;
2346 clk->max_rate = old_max;
2350 if (clk->exclusive_count)
2351 clk_core_rate_protect(clk->core);
2353 clk_prepare_unlock();
2357 EXPORT_SYMBOL_GPL(clk_set_rate_range);
2360 * clk_set_min_rate - set a minimum clock rate for a clock source
2361 * @clk: clock source
2362 * @rate: desired minimum clock rate in Hz, inclusive
2364 * Returns success (0) or negative errno.
2366 int clk_set_min_rate(struct clk *clk, unsigned long rate)
2371 return clk_set_rate_range(clk, rate, clk->max_rate);
2373 EXPORT_SYMBOL_GPL(clk_set_min_rate);
2376 * clk_set_max_rate - set a maximum clock rate for a clock source
2377 * @clk: clock source
2378 * @rate: desired maximum clock rate in Hz, inclusive
2380 * Returns success (0) or negative errno.
2382 int clk_set_max_rate(struct clk *clk, unsigned long rate)
2387 return clk_set_rate_range(clk, clk->min_rate, rate);
2389 EXPORT_SYMBOL_GPL(clk_set_max_rate);
2392 * clk_get_parent - return the parent of a clk
2393 * @clk: the clk whose parent gets returned
2395 * Simply returns clk->parent. Returns NULL if clk is NULL.
2397 struct clk *clk_get_parent(struct clk *clk)
2405 /* TODO: Create a per-user clk and change callers to call clk_put */
2406 parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
2407 clk_prepare_unlock();
2411 EXPORT_SYMBOL_GPL(clk_get_parent);
2413 static struct clk_core *__clk_init_parent(struct clk_core *core)
2417 if (core->num_parents > 1 && core->ops->get_parent)
2418 index = core->ops->get_parent(core->hw);
2420 return clk_core_get_parent_by_index(core, index);
2423 static void clk_core_reparent(struct clk_core *core,
2424 struct clk_core *new_parent)
2426 clk_reparent(core, new_parent);
2427 __clk_recalc_accuracies(core);
2428 __clk_recalc_rates(core, POST_RATE_CHANGE);
2431 void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
2436 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
2440 * clk_has_parent - check if a clock is a possible parent for another
2441 * @clk: clock source
2442 * @parent: parent clock source
2444 * This function can be used in drivers that need to check that a clock can be
2445 * the parent of another without actually changing the parent.
2447 * Returns true if @parent is a possible parent for @clk, false otherwise.
2449 bool clk_has_parent(struct clk *clk, struct clk *parent)
2451 struct clk_core *core, *parent_core;
2454 /* NULL clocks should be nops, so return success if either is NULL. */
2455 if (!clk || !parent)
2459 parent_core = parent->core;
2461 /* Optimize for the case where the parent is already the parent. */
2462 if (core->parent == parent_core)
2465 for (i = 0; i < core->num_parents; i++)
2466 if (!strcmp(core->parents[i].name, parent_core->name))
2471 EXPORT_SYMBOL_GPL(clk_has_parent);
2473 static int clk_core_set_parent_nolock(struct clk_core *core,
2474 struct clk_core *parent)
2478 unsigned long p_rate = 0;
2480 lockdep_assert_held(&prepare_lock);
2485 if (core->parent == parent)
2488 /* verify ops for multi-parent clks */
2489 if (core->num_parents > 1 && !core->ops->set_parent)
2492 /* check that we are allowed to re-parent if the clock is in use */
2493 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
2496 if (clk_core_rate_is_protected(core))
2499 /* try finding the new parent index */
2501 p_index = clk_fetch_parent_index(core, parent);
2503 pr_debug("%s: clk %s can not be parent of clk %s\n",
2504 __func__, parent->name, core->name);
2507 p_rate = parent->rate;
2510 ret = clk_pm_runtime_get(core);
2514 /* propagate PRE_RATE_CHANGE notifications */
2515 ret = __clk_speculate_rates(core, p_rate);
2517 /* abort if a driver objects */
2518 if (ret & NOTIFY_STOP_MASK)
2521 /* do the re-parent */
2522 ret = __clk_set_parent(core, parent, p_index);
2524 /* propagate rate an accuracy recalculation accordingly */
2526 __clk_recalc_rates(core, ABORT_RATE_CHANGE);
2528 __clk_recalc_rates(core, POST_RATE_CHANGE);
2529 __clk_recalc_accuracies(core);
2533 clk_pm_runtime_put(core);
2538 int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *parent)
2540 return clk_core_set_parent_nolock(hw->core, parent->core);
2542 EXPORT_SYMBOL_GPL(clk_hw_set_parent);
2545 * clk_set_parent - switch the parent of a mux clk
2546 * @clk: the mux clk whose input we are switching
2547 * @parent: the new input to clk
2549 * Re-parent clk to use parent as its new input source. If clk is in
2550 * prepared state, the clk will get enabled for the duration of this call. If
2551 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2552 * that, the reparenting is glitchy in hardware, etc), use the
2553 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2555 * After successfully changing clk's parent clk_set_parent will update the
2556 * clk topology, sysfs topology and propagate rate recalculation via
2557 * __clk_recalc_rates.
2559 * Returns 0 on success, -EERROR otherwise.
2561 int clk_set_parent(struct clk *clk, struct clk *parent)
2570 if (clk->exclusive_count)
2571 clk_core_rate_unprotect(clk->core);
2573 ret = clk_core_set_parent_nolock(clk->core,
2574 parent ? parent->core : NULL);
2576 if (clk->exclusive_count)
2577 clk_core_rate_protect(clk->core);
2579 clk_prepare_unlock();
2583 EXPORT_SYMBOL_GPL(clk_set_parent);
2585 static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
2589 lockdep_assert_held(&prepare_lock);
2594 if (clk_core_rate_is_protected(core))
2597 trace_clk_set_phase(core, degrees);
2599 if (core->ops->set_phase) {
2600 ret = core->ops->set_phase(core->hw, degrees);
2602 core->phase = degrees;
2605 trace_clk_set_phase_complete(core, degrees);
2611 * clk_set_phase - adjust the phase shift of a clock signal
2612 * @clk: clock signal source
2613 * @degrees: number of degrees the signal is shifted
2615 * Shifts the phase of a clock signal by the specified
2616 * degrees. Returns 0 on success, -EERROR otherwise.
2618 * This function makes no distinction about the input or reference
2619 * signal that we adjust the clock signal phase against. For example
2620 * phase locked-loop clock signal generators we may shift phase with
2621 * respect to feedback clock signal input, but for other cases the
2622 * clock phase may be shifted with respect to some other, unspecified
2625 * Additionally the concept of phase shift does not propagate through
2626 * the clock tree hierarchy, which sets it apart from clock rates and
2627 * clock accuracy. A parent clock phase attribute does not have an
2628 * impact on the phase attribute of a child clock.
2630 int clk_set_phase(struct clk *clk, int degrees)
2637 /* sanity check degrees */
2644 if (clk->exclusive_count)
2645 clk_core_rate_unprotect(clk->core);
2647 ret = clk_core_set_phase_nolock(clk->core, degrees);
2649 if (clk->exclusive_count)
2650 clk_core_rate_protect(clk->core);
2652 clk_prepare_unlock();
2656 EXPORT_SYMBOL_GPL(clk_set_phase);
2658 static int clk_core_get_phase(struct clk_core *core)
2662 lockdep_assert_held(&prepare_lock);
2663 if (!core->ops->get_phase)
2666 /* Always try to update cached phase if possible */
2667 ret = core->ops->get_phase(core->hw);
2675 * clk_get_phase - return the phase shift of a clock signal
2676 * @clk: clock signal source
2678 * Returns the phase shift of a clock node in degrees, otherwise returns
2681 int clk_get_phase(struct clk *clk)
2689 ret = clk_core_get_phase(clk->core);
2690 clk_prepare_unlock();
2694 EXPORT_SYMBOL_GPL(clk_get_phase);
2696 static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
2698 /* Assume a default value of 50% */
2703 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);
2705 static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
2707 struct clk_duty *duty = &core->duty;
2710 if (!core->ops->get_duty_cycle)
2711 return clk_core_update_duty_cycle_parent_nolock(core);
2713 ret = core->ops->get_duty_cycle(core->hw, duty);
2717 /* Don't trust the clock provider too much */
2718 if (duty->den == 0 || duty->num > duty->den) {
2726 clk_core_reset_duty_cycle_nolock(core);
2730 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
2735 core->flags & CLK_DUTY_CYCLE_PARENT) {
2736 ret = clk_core_update_duty_cycle_nolock(core->parent);
2737 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
2739 clk_core_reset_duty_cycle_nolock(core);
2745 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
2746 struct clk_duty *duty);
2748 static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
2749 struct clk_duty *duty)
2753 lockdep_assert_held(&prepare_lock);
2755 if (clk_core_rate_is_protected(core))
2758 trace_clk_set_duty_cycle(core, duty);
2760 if (!core->ops->set_duty_cycle)
2761 return clk_core_set_duty_cycle_parent_nolock(core, duty);
2763 ret = core->ops->set_duty_cycle(core->hw, duty);
2765 memcpy(&core->duty, duty, sizeof(*duty));
2767 trace_clk_set_duty_cycle_complete(core, duty);
2772 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
2773 struct clk_duty *duty)
2778 core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
2779 ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
2780 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
2787 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
2788 * @clk: clock signal source
2789 * @num: numerator of the duty cycle ratio to be applied
2790 * @den: denominator of the duty cycle ratio to be applied
2792 * Apply the duty cycle ratio if the ratio is valid and the clock can
2793 * perform this operation
2795 * Returns (0) on success, a negative errno otherwise.
2797 int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
2800 struct clk_duty duty;
2805 /* sanity check the ratio */
2806 if (den == 0 || num > den)
2814 if (clk->exclusive_count)
2815 clk_core_rate_unprotect(clk->core);
2817 ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
2819 if (clk->exclusive_count)
2820 clk_core_rate_protect(clk->core);
2822 clk_prepare_unlock();
2826 EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
2828 static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
2831 struct clk_duty *duty = &core->duty;
2836 ret = clk_core_update_duty_cycle_nolock(core);
2838 ret = mult_frac(scale, duty->num, duty->den);
2840 clk_prepare_unlock();
2846 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
2847 * @clk: clock signal source
2848 * @scale: scaling factor to be applied to represent the ratio as an integer
2850 * Returns the duty cycle ratio of a clock node multiplied by the provided
2851 * scaling factor, or negative errno on error.
2853 int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
2858 return clk_core_get_scaled_duty_cycle(clk->core, scale);
2860 EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
2863 * clk_is_match - check if two clk's point to the same hardware clock
2864 * @p: clk compared against q
2865 * @q: clk compared against p
2867 * Returns true if the two struct clk pointers both point to the same hardware
2868 * clock node. Put differently, returns true if struct clk *p and struct clk *q
2869 * share the same struct clk_core object.
2871 * Returns false otherwise. Note that two NULL clks are treated as matching.
2873 bool clk_is_match(const struct clk *p, const struct clk *q)
2875 /* trivial case: identical struct clk's or both NULL */
2879 /* true if clk->core pointers match. Avoid dereferencing garbage */
2880 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
2881 if (p->core == q->core)
2886 EXPORT_SYMBOL_GPL(clk_is_match);
2888 /*** debugfs support ***/
2890 #ifdef CONFIG_DEBUG_FS
2891 #include <linux/debugfs.h>
2893 static struct dentry *rootdir;
2894 static int inited = 0;
2895 static DEFINE_MUTEX(clk_debug_lock);
2896 static HLIST_HEAD(clk_debug_list);
2898 static struct hlist_head *orphan_list[] = {
2903 static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
2908 seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu ",
2910 30 - level * 3, c->name,
2911 c->enable_count, c->prepare_count, c->protect_count,
2912 clk_core_get_rate_recalc(c),
2913 clk_core_get_accuracy_recalc(c));
2915 phase = clk_core_get_phase(c);
2917 seq_printf(s, "%5d", phase);
2919 seq_puts(s, "-----");
2921 seq_printf(s, " %6d\n", clk_core_get_scaled_duty_cycle(c, 100000));
2924 static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
2927 struct clk_core *child;
2929 clk_summary_show_one(s, c, level);
2931 hlist_for_each_entry(child, &c->children, child_node)
2932 clk_summary_show_subtree(s, child, level + 1);
2935 static int clk_summary_show(struct seq_file *s, void *data)
2938 struct hlist_head **lists = (struct hlist_head **)s->private;
2940 seq_puts(s, " enable prepare protect duty\n");
2941 seq_puts(s, " clock count count count rate accuracy phase cycle\n");
2942 seq_puts(s, "---------------------------------------------------------------------------------------------\n");
2946 for (; *lists; lists++)
2947 hlist_for_each_entry(c, *lists, child_node)
2948 clk_summary_show_subtree(s, c, 0);
2950 clk_prepare_unlock();
2954 DEFINE_SHOW_ATTRIBUTE(clk_summary);
2956 static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
2959 unsigned long min_rate, max_rate;
2961 clk_core_get_boundaries(c, &min_rate, &max_rate);
2963 /* This should be JSON format, i.e. elements separated with a comma */
2964 seq_printf(s, "\"%s\": { ", c->name);
2965 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
2966 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
2967 seq_printf(s, "\"protect_count\": %d,", c->protect_count);
2968 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate_recalc(c));
2969 seq_printf(s, "\"min_rate\": %lu,", min_rate);
2970 seq_printf(s, "\"max_rate\": %lu,", max_rate);
2971 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy_recalc(c));
2972 phase = clk_core_get_phase(c);
2974 seq_printf(s, "\"phase\": %d,", phase);
2975 seq_printf(s, "\"duty_cycle\": %u",
2976 clk_core_get_scaled_duty_cycle(c, 100000));
2979 static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
2981 struct clk_core *child;
2983 clk_dump_one(s, c, level);
2985 hlist_for_each_entry(child, &c->children, child_node) {
2987 clk_dump_subtree(s, child, level + 1);
2993 static int clk_dump_show(struct seq_file *s, void *data)
2996 bool first_node = true;
2997 struct hlist_head **lists = (struct hlist_head **)s->private;
3002 for (; *lists; lists++) {
3003 hlist_for_each_entry(c, *lists, child_node) {
3007 clk_dump_subtree(s, c, 0);
3011 clk_prepare_unlock();
3016 DEFINE_SHOW_ATTRIBUTE(clk_dump);
3018 #undef CLOCK_ALLOW_WRITE_DEBUGFS
3019 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3021 * This can be dangerous, therefore don't provide any real compile time
3022 * configuration option for this feature.
3023 * People who want to use this will need to modify the source code directly.
3025 static int clk_rate_set(void *data, u64 val)
3027 struct clk_core *core = data;
3031 ret = clk_core_set_rate_nolock(core, val);
3032 clk_prepare_unlock();
3037 #define clk_rate_mode 0644
3039 #define clk_rate_set NULL
3040 #define clk_rate_mode 0444
3043 static int clk_rate_get(void *data, u64 *val)
3045 struct clk_core *core = data;
3051 DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops, clk_rate_get, clk_rate_set, "%llu\n");
3053 static const struct {
3057 #define ENTRY(f) { f, #f }
3058 ENTRY(CLK_SET_RATE_GATE),
3059 ENTRY(CLK_SET_PARENT_GATE),
3060 ENTRY(CLK_SET_RATE_PARENT),
3061 ENTRY(CLK_IGNORE_UNUSED),
3062 ENTRY(CLK_GET_RATE_NOCACHE),
3063 ENTRY(CLK_SET_RATE_NO_REPARENT),
3064 ENTRY(CLK_GET_ACCURACY_NOCACHE),
3065 ENTRY(CLK_RECALC_NEW_RATES),
3066 ENTRY(CLK_SET_RATE_UNGATE),
3067 ENTRY(CLK_IS_CRITICAL),
3068 ENTRY(CLK_OPS_PARENT_ENABLE),
3069 ENTRY(CLK_DUTY_CYCLE_PARENT),
3073 static int clk_flags_show(struct seq_file *s, void *data)
3075 struct clk_core *core = s->private;
3076 unsigned long flags = core->flags;
3079 for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
3080 if (flags & clk_flags[i].flag) {
3081 seq_printf(s, "%s\n", clk_flags[i].name);
3082 flags &= ~clk_flags[i].flag;
3087 seq_printf(s, "0x%lx\n", flags);
3092 DEFINE_SHOW_ATTRIBUTE(clk_flags);
3094 static void possible_parent_show(struct seq_file *s, struct clk_core *core,
3095 unsigned int i, char terminator)
3097 struct clk_core *parent;
3100 * Go through the following options to fetch a parent's name.
3102 * 1. Fetch the registered parent clock and use its name
3103 * 2. Use the global (fallback) name if specified
3104 * 3. Use the local fw_name if provided
3105 * 4. Fetch parent clock's clock-output-name if DT index was set
3107 * This may still fail in some cases, such as when the parent is
3108 * specified directly via a struct clk_hw pointer, but it isn't
3111 parent = clk_core_get_parent_by_index(core, i);
3113 seq_puts(s, parent->name);
3114 else if (core->parents[i].name)
3115 seq_puts(s, core->parents[i].name);
3116 else if (core->parents[i].fw_name)
3117 seq_printf(s, "<%s>(fw)", core->parents[i].fw_name);
3118 else if (core->parents[i].index >= 0)
3120 of_clk_get_parent_name(core->of_node,
3121 core->parents[i].index));
3123 seq_puts(s, "(missing)");
3125 seq_putc(s, terminator);
3128 static int possible_parents_show(struct seq_file *s, void *data)
3130 struct clk_core *core = s->private;
3133 for (i = 0; i < core->num_parents - 1; i++)
3134 possible_parent_show(s, core, i, ' ');
3136 possible_parent_show(s, core, i, '\n');
3140 DEFINE_SHOW_ATTRIBUTE(possible_parents);
3142 static int current_parent_show(struct seq_file *s, void *data)
3144 struct clk_core *core = s->private;
3147 seq_printf(s, "%s\n", core->parent->name);
3151 DEFINE_SHOW_ATTRIBUTE(current_parent);
3153 static int clk_duty_cycle_show(struct seq_file *s, void *data)
3155 struct clk_core *core = s->private;
3156 struct clk_duty *duty = &core->duty;
3158 seq_printf(s, "%u/%u\n", duty->num, duty->den);
3162 DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
3164 static int clk_min_rate_show(struct seq_file *s, void *data)
3166 struct clk_core *core = s->private;
3167 unsigned long min_rate, max_rate;
3170 clk_core_get_boundaries(core, &min_rate, &max_rate);
3171 clk_prepare_unlock();
3172 seq_printf(s, "%lu\n", min_rate);
3176 DEFINE_SHOW_ATTRIBUTE(clk_min_rate);
3178 static int clk_max_rate_show(struct seq_file *s, void *data)
3180 struct clk_core *core = s->private;
3181 unsigned long min_rate, max_rate;
3184 clk_core_get_boundaries(core, &min_rate, &max_rate);
3185 clk_prepare_unlock();
3186 seq_printf(s, "%lu\n", max_rate);
3190 DEFINE_SHOW_ATTRIBUTE(clk_max_rate);
3192 static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
3194 struct dentry *root;
3196 if (!core || !pdentry)
3199 root = debugfs_create_dir(core->name, pdentry);
3200 core->dentry = root;
3202 debugfs_create_file("clk_rate", clk_rate_mode, root, core,
3204 debugfs_create_file("clk_min_rate", 0444, root, core, &clk_min_rate_fops);
3205 debugfs_create_file("clk_max_rate", 0444, root, core, &clk_max_rate_fops);
3206 debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
3207 debugfs_create_u32("clk_phase", 0444, root, &core->phase);
3208 debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
3209 debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
3210 debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
3211 debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
3212 debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
3213 debugfs_create_file("clk_duty_cycle", 0444, root, core,
3214 &clk_duty_cycle_fops);
3216 if (core->num_parents > 0)
3217 debugfs_create_file("clk_parent", 0444, root, core,
3218 ¤t_parent_fops);
3220 if (core->num_parents > 1)
3221 debugfs_create_file("clk_possible_parents", 0444, root, core,
3222 &possible_parents_fops);
3224 if (core->ops->debug_init)
3225 core->ops->debug_init(core->hw, core->dentry);
3229 * clk_debug_register - add a clk node to the debugfs clk directory
3230 * @core: the clk being added to the debugfs clk directory
3232 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
3233 * initialized. Otherwise it bails out early since the debugfs clk directory
3234 * will be created lazily by clk_debug_init as part of a late_initcall.
3236 static void clk_debug_register(struct clk_core *core)
3238 mutex_lock(&clk_debug_lock);
3239 hlist_add_head(&core->debug_node, &clk_debug_list);
3241 clk_debug_create_one(core, rootdir);
3242 mutex_unlock(&clk_debug_lock);
3246 * clk_debug_unregister - remove a clk node from the debugfs clk directory
3247 * @core: the clk being removed from the debugfs clk directory
3249 * Dynamically removes a clk and all its child nodes from the
3250 * debugfs clk directory if clk->dentry points to debugfs created by
3251 * clk_debug_register in __clk_core_init.
3253 static void clk_debug_unregister(struct clk_core *core)
3255 mutex_lock(&clk_debug_lock);
3256 hlist_del_init(&core->debug_node);
3257 debugfs_remove_recursive(core->dentry);
3258 core->dentry = NULL;
3259 mutex_unlock(&clk_debug_lock);
3263 * clk_debug_init - lazily populate the debugfs clk directory
3265 * clks are often initialized very early during boot before memory can be
3266 * dynamically allocated and well before debugfs is setup. This function
3267 * populates the debugfs clk directory once at boot-time when we know that
3268 * debugfs is setup. It should only be called once at boot-time, all other clks
3269 * added dynamically will be done so with clk_debug_register.
3271 static int __init clk_debug_init(void)
3273 struct clk_core *core;
3275 rootdir = debugfs_create_dir("clk", NULL);
3277 debugfs_create_file("clk_summary", 0444, rootdir, &all_lists,
3279 debugfs_create_file("clk_dump", 0444, rootdir, &all_lists,
3281 debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list,
3283 debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list,
3286 mutex_lock(&clk_debug_lock);
3287 hlist_for_each_entry(core, &clk_debug_list, debug_node)
3288 clk_debug_create_one(core, rootdir);
3291 mutex_unlock(&clk_debug_lock);
3295 late_initcall(clk_debug_init);
3297 static inline void clk_debug_register(struct clk_core *core) { }
3298 static inline void clk_debug_reparent(struct clk_core *core,
3299 struct clk_core *new_parent)
3302 static inline void clk_debug_unregister(struct clk_core *core)
3307 static void clk_core_reparent_orphans_nolock(void)
3309 struct clk_core *orphan;
3310 struct hlist_node *tmp2;
3313 * walk the list of orphan clocks and reparent any that newly finds a
3316 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
3317 struct clk_core *parent = __clk_init_parent(orphan);
3320 * We need to use __clk_set_parent_before() and _after() to
3321 * to properly migrate any prepare/enable count of the orphan
3322 * clock. This is important for CLK_IS_CRITICAL clocks, which
3323 * are enabled during init but might not have a parent yet.
3326 /* update the clk tree topology */
3327 __clk_set_parent_before(orphan, parent);
3328 __clk_set_parent_after(orphan, parent, NULL);
3329 __clk_recalc_accuracies(orphan);
3330 __clk_recalc_rates(orphan, 0);
3336 * __clk_core_init - initialize the data structures in a struct clk_core
3337 * @core: clk_core being initialized
3339 * Initializes the lists in struct clk_core, queries the hardware for the
3340 * parent and rate and sets them both.
3342 static int __clk_core_init(struct clk_core *core)
3345 struct clk_core *parent;
3354 ret = clk_pm_runtime_get(core);
3358 /* check to see if a clock with this name is already registered */
3359 if (clk_core_lookup(core->name)) {
3360 pr_debug("%s: clk %s already initialized\n",
3361 __func__, core->name);
3366 /* check that clk_ops are sane. See Documentation/driver-api/clk.rst */
3367 if (core->ops->set_rate &&
3368 !((core->ops->round_rate || core->ops->determine_rate) &&
3369 core->ops->recalc_rate)) {
3370 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
3371 __func__, core->name);
3376 if (core->ops->set_parent && !core->ops->get_parent) {
3377 pr_err("%s: %s must implement .get_parent & .set_parent\n",
3378 __func__, core->name);
3383 if (core->num_parents > 1 && !core->ops->get_parent) {
3384 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
3385 __func__, core->name);
3390 if (core->ops->set_rate_and_parent &&
3391 !(core->ops->set_parent && core->ops->set_rate)) {
3392 pr_err("%s: %s must implement .set_parent & .set_rate\n",
3393 __func__, core->name);
3399 * optional platform-specific magic
3401 * The .init callback is not used by any of the basic clock types, but
3402 * exists for weird hardware that must perform initialization magic for
3403 * CCF to get an accurate view of clock for any other callbacks. It may
3404 * also be used needs to perform dynamic allocations. Such allocation
3405 * must be freed in the terminate() callback.
3406 * This callback shall not be used to initialize the parameters state,
3407 * such as rate, parent, etc ...
3409 * If it exist, this callback should called before any other callback of
3412 if (core->ops->init) {
3413 ret = core->ops->init(core->hw);
3418 parent = core->parent = __clk_init_parent(core);
3421 * Populate core->parent if parent has already been clk_core_init'd. If
3422 * parent has not yet been clk_core_init'd then place clk in the orphan
3423 * list. If clk doesn't have any parents then place it in the root
3426 * Every time a new clk is clk_init'd then we walk the list of orphan
3427 * clocks and re-parent any that are children of the clock currently
3431 hlist_add_head(&core->child_node, &parent->children);
3432 core->orphan = parent->orphan;
3433 } else if (!core->num_parents) {
3434 hlist_add_head(&core->child_node, &clk_root_list);
3435 core->orphan = false;
3437 hlist_add_head(&core->child_node, &clk_orphan_list);
3438 core->orphan = true;
3442 * Set clk's accuracy. The preferred method is to use
3443 * .recalc_accuracy. For simple clocks and lazy developers the default
3444 * fallback is to use the parent's accuracy. If a clock doesn't have a
3445 * parent (or is orphaned) then accuracy is set to zero (perfect
3448 if (core->ops->recalc_accuracy)
3449 core->accuracy = core->ops->recalc_accuracy(core->hw,
3450 clk_core_get_accuracy_no_lock(parent));
3452 core->accuracy = parent->accuracy;
3457 * Set clk's phase by clk_core_get_phase() caching the phase.
3458 * Since a phase is by definition relative to its parent, just
3459 * query the current clock phase, or just assume it's in phase.
3461 phase = clk_core_get_phase(core);
3464 pr_warn("%s: Failed to get phase for clk '%s'\n", __func__,
3470 * Set clk's duty cycle.
3472 clk_core_update_duty_cycle_nolock(core);
3475 * Set clk's rate. The preferred method is to use .recalc_rate. For
3476 * simple clocks and lazy developers the default fallback is to use the
3477 * parent's rate. If a clock doesn't have a parent (or is orphaned)
3478 * then rate is set to zero.
3480 if (core->ops->recalc_rate)
3481 rate = core->ops->recalc_rate(core->hw,
3482 clk_core_get_rate_nolock(parent));
3484 rate = parent->rate;
3487 core->rate = core->req_rate = rate;
3490 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
3491 * don't get accidentally disabled when walking the orphan tree and
3492 * reparenting clocks
3494 if (core->flags & CLK_IS_CRITICAL) {
3495 unsigned long flags;
3497 ret = clk_core_prepare(core);
3499 pr_warn("%s: critical clk '%s' failed to prepare\n",
3500 __func__, core->name);
3504 flags = clk_enable_lock();
3505 ret = clk_core_enable(core);
3506 clk_enable_unlock(flags);
3508 pr_warn("%s: critical clk '%s' failed to enable\n",
3509 __func__, core->name);
3510 clk_core_unprepare(core);
3515 clk_core_reparent_orphans_nolock();
3518 kref_init(&core->ref);
3520 clk_pm_runtime_put(core);
3523 hlist_del_init(&core->child_node);
3525 clk_prepare_unlock();
3528 clk_debug_register(core);
3534 * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core
3535 * @core: clk to add consumer to
3536 * @clk: consumer to link to a clk
3538 static void clk_core_link_consumer(struct clk_core *core, struct clk *clk)
3541 hlist_add_head(&clk->clks_node, &core->clks);
3542 clk_prepare_unlock();
3546 * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core
3547 * @clk: consumer to unlink
3549 static void clk_core_unlink_consumer(struct clk *clk)
3551 lockdep_assert_held(&prepare_lock);
3552 hlist_del(&clk->clks_node);
3556 * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core
3557 * @core: clk to allocate a consumer for
3558 * @dev_id: string describing device name
3559 * @con_id: connection ID string on device
3561 * Returns: clk consumer left unlinked from the consumer list
3563 static struct clk *alloc_clk(struct clk_core *core, const char *dev_id,
3568 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
3570 return ERR_PTR(-ENOMEM);
3573 clk->dev_id = dev_id;
3574 clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
3575 clk->max_rate = ULONG_MAX;
3581 * free_clk - Free a clk consumer
3582 * @clk: clk consumer to free
3584 * Note, this assumes the clk has been unlinked from the clk_core consumer
3587 static void free_clk(struct clk *clk)
3589 kfree_const(clk->con_id);
3594 * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given
3596 * @dev: clk consumer device
3597 * @hw: clk_hw associated with the clk being consumed
3598 * @dev_id: string describing device name
3599 * @con_id: connection ID string on device
3601 * This is the main function used to create a clk pointer for use by clk
3602 * consumers. It connects a consumer to the clk_core and clk_hw structures
3603 * used by the framework and clk provider respectively.
3605 struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
3606 const char *dev_id, const char *con_id)
3609 struct clk_core *core;
3611 /* This is to allow this function to be chained to others */
3612 if (IS_ERR_OR_NULL(hw))
3613 return ERR_CAST(hw);
3616 clk = alloc_clk(core, dev_id, con_id);
3621 if (!try_module_get(core->owner)) {
3623 return ERR_PTR(-ENOENT);
3626 kref_get(&core->ref);
3627 clk_core_link_consumer(core, clk);
3632 static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
3642 *dst_p = dst = kstrdup_const(src, GFP_KERNEL);
3649 static int clk_core_populate_parent_map(struct clk_core *core,
3650 const struct clk_init_data *init)
3652 u8 num_parents = init->num_parents;
3653 const char * const *parent_names = init->parent_names;
3654 const struct clk_hw **parent_hws = init->parent_hws;
3655 const struct clk_parent_data *parent_data = init->parent_data;
3657 struct clk_parent_map *parents, *parent;
3663 * Avoid unnecessary string look-ups of clk_core's possible parents by
3664 * having a cache of names/clk_hw pointers to clk_core pointers.
3666 parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
3667 core->parents = parents;
3671 /* Copy everything over because it might be __initdata */
3672 for (i = 0, parent = parents; i < num_parents; i++, parent++) {
3675 /* throw a WARN if any entries are NULL */
3676 WARN(!parent_names[i],
3677 "%s: invalid NULL in %s's .parent_names\n",
3678 __func__, core->name);
3679 ret = clk_cpy_name(&parent->name, parent_names[i],
3681 } else if (parent_data) {
3682 parent->hw = parent_data[i].hw;
3683 parent->index = parent_data[i].index;
3684 ret = clk_cpy_name(&parent->fw_name,
3685 parent_data[i].fw_name, false);
3687 ret = clk_cpy_name(&parent->name,
3688 parent_data[i].name,
3690 } else if (parent_hws) {
3691 parent->hw = parent_hws[i];
3694 WARN(1, "Must specify parents if num_parents > 0\n");
3699 kfree_const(parents[i].name);
3700 kfree_const(parents[i].fw_name);
3711 static void clk_core_free_parent_map(struct clk_core *core)
3713 int i = core->num_parents;
3715 if (!core->num_parents)
3719 kfree_const(core->parents[i].name);
3720 kfree_const(core->parents[i].fw_name);
3723 kfree(core->parents);
3727 __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
3730 struct clk_core *core;
3731 const struct clk_init_data *init = hw->init;
3734 * The init data is not supposed to be used outside of registration path.
3735 * Set it to NULL so that provider drivers can't use it either and so that
3736 * we catch use of hw->init early on in the core.
3740 core = kzalloc(sizeof(*core), GFP_KERNEL);
3746 core->name = kstrdup_const(init->name, GFP_KERNEL);
3752 if (WARN_ON(!init->ops)) {
3756 core->ops = init->ops;
3758 if (dev && pm_runtime_enabled(dev))
3759 core->rpm_enabled = true;
3762 if (dev && dev->driver)
3763 core->owner = dev->driver->owner;
3765 core->flags = init->flags;
3766 core->num_parents = init->num_parents;
3768 core->max_rate = ULONG_MAX;
3771 ret = clk_core_populate_parent_map(core, init);
3775 INIT_HLIST_HEAD(&core->clks);
3778 * Don't call clk_hw_create_clk() here because that would pin the
3779 * provider module to itself and prevent it from ever being removed.
3781 hw->clk = alloc_clk(core, NULL, NULL);
3782 if (IS_ERR(hw->clk)) {
3783 ret = PTR_ERR(hw->clk);
3784 goto fail_create_clk;
3787 clk_core_link_consumer(hw->core, hw->clk);
3789 ret = __clk_core_init(core);
3794 clk_core_unlink_consumer(hw->clk);
3795 clk_prepare_unlock();
3801 clk_core_free_parent_map(core);
3804 kfree_const(core->name);
3808 return ERR_PTR(ret);
3812 * dev_or_parent_of_node() - Get device node of @dev or @dev's parent
3813 * @dev: Device to get device node of
3815 * Return: device node pointer of @dev, or the device node pointer of
3816 * @dev->parent if dev doesn't have a device node, or NULL if neither
3817 * @dev or @dev->parent have a device node.
3819 static struct device_node *dev_or_parent_of_node(struct device *dev)
3821 struct device_node *np;
3826 np = dev_of_node(dev);
3828 np = dev_of_node(dev->parent);
3834 * clk_register - allocate a new clock, register it and return an opaque cookie
3835 * @dev: device that is registering this clock
3836 * @hw: link to hardware-specific clock data
3838 * clk_register is the *deprecated* interface for populating the clock tree with
3839 * new clock nodes. Use clk_hw_register() instead.
3841 * Returns: a pointer to the newly allocated struct clk which
3842 * cannot be dereferenced by driver code but may be used in conjunction with the
3843 * rest of the clock API. In the event of an error clk_register will return an
3844 * error code; drivers must test for an error code after calling clk_register.
3846 struct clk *clk_register(struct device *dev, struct clk_hw *hw)
3848 return __clk_register(dev, dev_or_parent_of_node(dev), hw);
3850 EXPORT_SYMBOL_GPL(clk_register);
3853 * clk_hw_register - register a clk_hw and return an error code
3854 * @dev: device that is registering this clock
3855 * @hw: link to hardware-specific clock data
3857 * clk_hw_register is the primary interface for populating the clock tree with
3858 * new clock nodes. It returns an integer equal to zero indicating success or
3859 * less than zero indicating failure. Drivers must test for an error code after
3860 * calling clk_hw_register().
3862 int clk_hw_register(struct device *dev, struct clk_hw *hw)
3864 return PTR_ERR_OR_ZERO(__clk_register(dev, dev_or_parent_of_node(dev),
3867 EXPORT_SYMBOL_GPL(clk_hw_register);
3870 * of_clk_hw_register - register a clk_hw and return an error code
3871 * @node: device_node of device that is registering this clock
3872 * @hw: link to hardware-specific clock data
3874 * of_clk_hw_register() is the primary interface for populating the clock tree
3875 * with new clock nodes when a struct device is not available, but a struct
3876 * device_node is. It returns an integer equal to zero indicating success or
3877 * less than zero indicating failure. Drivers must test for an error code after
3878 * calling of_clk_hw_register().
3880 int of_clk_hw_register(struct device_node *node, struct clk_hw *hw)
3882 return PTR_ERR_OR_ZERO(__clk_register(NULL, node, hw));
3884 EXPORT_SYMBOL_GPL(of_clk_hw_register);
3886 /* Free memory allocated for a clock. */
3887 static void __clk_release(struct kref *ref)
3889 struct clk_core *core = container_of(ref, struct clk_core, ref);
3891 lockdep_assert_held(&prepare_lock);
3893 clk_core_free_parent_map(core);
3894 kfree_const(core->name);
3899 * Empty clk_ops for unregistered clocks. These are used temporarily
3900 * after clk_unregister() was called on a clock and until last clock
3901 * consumer calls clk_put() and the struct clk object is freed.
3903 static int clk_nodrv_prepare_enable(struct clk_hw *hw)
3908 static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
3913 static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
3914 unsigned long parent_rate)
3919 static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
3924 static const struct clk_ops clk_nodrv_ops = {
3925 .enable = clk_nodrv_prepare_enable,
3926 .disable = clk_nodrv_disable_unprepare,
3927 .prepare = clk_nodrv_prepare_enable,
3928 .unprepare = clk_nodrv_disable_unprepare,
3929 .set_rate = clk_nodrv_set_rate,
3930 .set_parent = clk_nodrv_set_parent,
3933 static void clk_core_evict_parent_cache_subtree(struct clk_core *root,
3934 struct clk_core *target)
3937 struct clk_core *child;
3939 for (i = 0; i < root->num_parents; i++)
3940 if (root->parents[i].core == target)
3941 root->parents[i].core = NULL;
3943 hlist_for_each_entry(child, &root->children, child_node)
3944 clk_core_evict_parent_cache_subtree(child, target);
3947 /* Remove this clk from all parent caches */
3948 static void clk_core_evict_parent_cache(struct clk_core *core)
3950 struct hlist_head **lists;
3951 struct clk_core *root;
3953 lockdep_assert_held(&prepare_lock);
3955 for (lists = all_lists; *lists; lists++)
3956 hlist_for_each_entry(root, *lists, child_node)
3957 clk_core_evict_parent_cache_subtree(root, core);
3962 * clk_unregister - unregister a currently registered clock
3963 * @clk: clock to unregister
3965 void clk_unregister(struct clk *clk)
3967 unsigned long flags;
3968 const struct clk_ops *ops;
3970 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
3973 clk_debug_unregister(clk->core);
3977 ops = clk->core->ops;
3978 if (ops == &clk_nodrv_ops) {
3979 pr_err("%s: unregistered clock: %s\n", __func__,
3984 * Assign empty clock ops for consumers that might still hold
3985 * a reference to this clock.
3987 flags = clk_enable_lock();
3988 clk->core->ops = &clk_nodrv_ops;
3989 clk_enable_unlock(flags);
3992 ops->terminate(clk->core->hw);
3994 if (!hlist_empty(&clk->core->children)) {
3995 struct clk_core *child;
3996 struct hlist_node *t;
3998 /* Reparent all children to the orphan list. */
3999 hlist_for_each_entry_safe(child, t, &clk->core->children,
4001 clk_core_set_parent_nolock(child, NULL);
4004 clk_core_evict_parent_cache(clk->core);
4006 hlist_del_init(&clk->core->child_node);
4008 if (clk->core->prepare_count)
4009 pr_warn("%s: unregistering prepared clock: %s\n",
4010 __func__, clk->core->name);
4012 if (clk->core->protect_count)
4013 pr_warn("%s: unregistering protected clock: %s\n",
4014 __func__, clk->core->name);
4016 kref_put(&clk->core->ref, __clk_release);
4019 clk_prepare_unlock();
4021 EXPORT_SYMBOL_GPL(clk_unregister);
4024 * clk_hw_unregister - unregister a currently registered clk_hw
4025 * @hw: hardware-specific clock data to unregister
4027 void clk_hw_unregister(struct clk_hw *hw)
4029 clk_unregister(hw->clk);
4031 EXPORT_SYMBOL_GPL(clk_hw_unregister);
4033 static void devm_clk_release(struct device *dev, void *res)
4035 clk_unregister(*(struct clk **)res);
4038 static void devm_clk_hw_release(struct device *dev, void *res)
4040 clk_hw_unregister(*(struct clk_hw **)res);
4044 * devm_clk_register - resource managed clk_register()
4045 * @dev: device that is registering this clock
4046 * @hw: link to hardware-specific clock data
4048 * Managed clk_register(). This function is *deprecated*, use devm_clk_hw_register() instead.
4050 * Clocks returned from this function are automatically clk_unregister()ed on
4051 * driver detach. See clk_register() for more information.
4053 struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
4058 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
4060 return ERR_PTR(-ENOMEM);
4062 clk = clk_register(dev, hw);
4065 devres_add(dev, clkp);
4072 EXPORT_SYMBOL_GPL(devm_clk_register);
4075 * devm_clk_hw_register - resource managed clk_hw_register()
4076 * @dev: device that is registering this clock
4077 * @hw: link to hardware-specific clock data
4079 * Managed clk_hw_register(). Clocks registered by this function are
4080 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
4081 * for more information.
4083 int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
4085 struct clk_hw **hwp;
4088 hwp = devres_alloc(devm_clk_hw_release, sizeof(*hwp), GFP_KERNEL);
4092 ret = clk_hw_register(dev, hw);
4095 devres_add(dev, hwp);
4102 EXPORT_SYMBOL_GPL(devm_clk_hw_register);
4104 static int devm_clk_match(struct device *dev, void *res, void *data)
4106 struct clk *c = res;
4112 static int devm_clk_hw_match(struct device *dev, void *res, void *data)
4114 struct clk_hw *hw = res;
4122 * devm_clk_unregister - resource managed clk_unregister()
4123 * @clk: clock to unregister
4125 * Deallocate a clock allocated with devm_clk_register(). Normally
4126 * this function will not need to be called and the resource management
4127 * code will ensure that the resource is freed.
4129 void devm_clk_unregister(struct device *dev, struct clk *clk)
4131 WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
4133 EXPORT_SYMBOL_GPL(devm_clk_unregister);
4136 * devm_clk_hw_unregister - resource managed clk_hw_unregister()
4137 * @dev: device that is unregistering the hardware-specific clock data
4138 * @hw: link to hardware-specific clock data
4140 * Unregister a clk_hw registered with devm_clk_hw_register(). Normally
4141 * this function will not need to be called and the resource management
4142 * code will ensure that the resource is freed.
4144 void devm_clk_hw_unregister(struct device *dev, struct clk_hw *hw)
4146 WARN_ON(devres_release(dev, devm_clk_hw_release, devm_clk_hw_match,
4149 EXPORT_SYMBOL_GPL(devm_clk_hw_unregister);
4155 void __clk_put(struct clk *clk)
4157 struct module *owner;
4159 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4165 * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
4166 * given user should be balanced with calls to clk_rate_exclusive_put()
4167 * and by that same consumer
4169 if (WARN_ON(clk->exclusive_count)) {
4170 /* We voiced our concern, let's sanitize the situation */
4171 clk->core->protect_count -= (clk->exclusive_count - 1);
4172 clk_core_rate_unprotect(clk->core);
4173 clk->exclusive_count = 0;
4176 hlist_del(&clk->clks_node);
4177 if (clk->min_rate > clk->core->req_rate ||
4178 clk->max_rate < clk->core->req_rate)
4179 clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
4181 owner = clk->core->owner;
4182 kref_put(&clk->core->ref, __clk_release);
4184 clk_prepare_unlock();
4191 /*** clk rate change notifiers ***/
4194 * clk_notifier_register - add a clk rate change notifier
4195 * @clk: struct clk * to watch
4196 * @nb: struct notifier_block * with callback info
4198 * Request notification when clk's rate changes. This uses an SRCU
4199 * notifier because we want it to block and notifier unregistrations are
4200 * uncommon. The callbacks associated with the notifier must not
4201 * re-enter into the clk framework by calling any top-level clk APIs;
4202 * this will cause a nested prepare_lock mutex.
4204 * In all notification cases (pre, post and abort rate change) the original
4205 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
4206 * and the new frequency is passed via struct clk_notifier_data.new_rate.
4208 * clk_notifier_register() must be called from non-atomic context.
4209 * Returns -EINVAL if called with null arguments, -ENOMEM upon
4210 * allocation failure; otherwise, passes along the return value of
4211 * srcu_notifier_chain_register().
4213 int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
4215 struct clk_notifier *cn;
4223 /* search the list of notifiers for this clk */
4224 list_for_each_entry(cn, &clk_notifier_list, node)
4228 /* if clk wasn't in the notifier list, allocate new clk_notifier */
4229 if (cn->clk != clk) {
4230 cn = kzalloc(sizeof(*cn), GFP_KERNEL);
4235 srcu_init_notifier_head(&cn->notifier_head);
4237 list_add(&cn->node, &clk_notifier_list);
4240 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
4242 clk->core->notifier_count++;
4245 clk_prepare_unlock();
4249 EXPORT_SYMBOL_GPL(clk_notifier_register);
4252 * clk_notifier_unregister - remove a clk rate change notifier
4253 * @clk: struct clk *
4254 * @nb: struct notifier_block * with callback info
4256 * Request no further notification for changes to 'clk' and frees memory
4257 * allocated in clk_notifier_register.
4259 * Returns -EINVAL if called with null arguments; otherwise, passes
4260 * along the return value of srcu_notifier_chain_unregister().
4262 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
4264 struct clk_notifier *cn = NULL;
4272 list_for_each_entry(cn, &clk_notifier_list, node)
4276 if (cn->clk == clk) {
4277 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
4279 clk->core->notifier_count--;
4281 /* XXX the notifier code should handle this better */
4282 if (!cn->notifier_head.head) {
4283 srcu_cleanup_notifier_head(&cn->notifier_head);
4284 list_del(&cn->node);
4292 clk_prepare_unlock();
4296 EXPORT_SYMBOL_GPL(clk_notifier_unregister);
4299 static void clk_core_reparent_orphans(void)
4302 clk_core_reparent_orphans_nolock();
4303 clk_prepare_unlock();
4307 * struct of_clk_provider - Clock provider registration structure
4308 * @link: Entry in global list of clock providers
4309 * @node: Pointer to device tree node of clock provider
4310 * @get: Get clock callback. Returns NULL or a struct clk for the
4311 * given clock specifier
4312 * @data: context pointer to be passed into @get callback
4314 struct of_clk_provider {
4315 struct list_head link;
4317 struct device_node *node;
4318 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
4319 struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
4323 extern struct of_device_id __clk_of_table;
4324 static const struct of_device_id __clk_of_table_sentinel
4325 __used __section(__clk_of_table_end);
4327 static LIST_HEAD(of_clk_providers);
4328 static DEFINE_MUTEX(of_clk_mutex);
4330 struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
4335 EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
4337 struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
4341 EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
4343 struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
4345 struct clk_onecell_data *clk_data = data;
4346 unsigned int idx = clkspec->args[0];
4348 if (idx >= clk_data->clk_num) {
4349 pr_err("%s: invalid clock index %u\n", __func__, idx);
4350 return ERR_PTR(-EINVAL);
4353 return clk_data->clks[idx];
4355 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
4358 of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
4360 struct clk_hw_onecell_data *hw_data = data;
4361 unsigned int idx = clkspec->args[0];
4363 if (idx >= hw_data->num) {
4364 pr_err("%s: invalid index %u\n", __func__, idx);
4365 return ERR_PTR(-EINVAL);
4368 return hw_data->hws[idx];
4370 EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
4373 * of_clk_add_provider() - Register a clock provider for a node
4374 * @np: Device node pointer associated with clock provider
4375 * @clk_src_get: callback for decoding clock
4376 * @data: context pointer for @clk_src_get callback.
4378 * This function is *deprecated*. Use of_clk_add_hw_provider() instead.
4380 int of_clk_add_provider(struct device_node *np,
4381 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
4385 struct of_clk_provider *cp;
4388 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
4392 cp->node = of_node_get(np);
4394 cp->get = clk_src_get;
4396 mutex_lock(&of_clk_mutex);
4397 list_add(&cp->link, &of_clk_providers);
4398 mutex_unlock(&of_clk_mutex);
4399 pr_debug("Added clock from %pOF\n", np);
4401 clk_core_reparent_orphans();
4403 ret = of_clk_set_defaults(np, true);
4405 of_clk_del_provider(np);
4409 EXPORT_SYMBOL_GPL(of_clk_add_provider);
4412 * of_clk_add_hw_provider() - Register a clock provider for a node
4413 * @np: Device node pointer associated with clock provider
4414 * @get: callback for decoding clk_hw
4415 * @data: context pointer for @get callback.
4417 int of_clk_add_hw_provider(struct device_node *np,
4418 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
4422 struct of_clk_provider *cp;
4425 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
4429 cp->node = of_node_get(np);
4433 mutex_lock(&of_clk_mutex);
4434 list_add(&cp->link, &of_clk_providers);
4435 mutex_unlock(&of_clk_mutex);
4436 pr_debug("Added clk_hw provider from %pOF\n", np);
4438 clk_core_reparent_orphans();
4440 ret = of_clk_set_defaults(np, true);
4442 of_clk_del_provider(np);
4446 EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
4448 static void devm_of_clk_release_provider(struct device *dev, void *res)
4450 of_clk_del_provider(*(struct device_node **)res);
4454 * We allow a child device to use its parent device as the clock provider node
4455 * for cases like MFD sub-devices where the child device driver wants to use
4456 * devm_*() APIs but not list the device in DT as a sub-node.
4458 static struct device_node *get_clk_provider_node(struct device *dev)
4460 struct device_node *np, *parent_np;
4463 parent_np = dev->parent ? dev->parent->of_node : NULL;
4465 if (!of_find_property(np, "#clock-cells", NULL))
4466 if (of_find_property(parent_np, "#clock-cells", NULL))
4473 * devm_of_clk_add_hw_provider() - Managed clk provider node registration
4474 * @dev: Device acting as the clock provider (used for DT node and lifetime)
4475 * @get: callback for decoding clk_hw
4476 * @data: context pointer for @get callback
4478 * Registers clock provider for given device's node. If the device has no DT
4479 * node or if the device node lacks of clock provider information (#clock-cells)
4480 * then the parent device's node is scanned for this information. If parent node
4481 * has the #clock-cells then it is used in registration. Provider is
4482 * automatically released at device exit.
4484 * Return: 0 on success or an errno on failure.
4486 int devm_of_clk_add_hw_provider(struct device *dev,
4487 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
4491 struct device_node **ptr, *np;
4494 ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
4499 np = get_clk_provider_node(dev);
4500 ret = of_clk_add_hw_provider(np, get, data);
4503 devres_add(dev, ptr);
4510 EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);
4513 * of_clk_del_provider() - Remove a previously registered clock provider
4514 * @np: Device node pointer associated with clock provider
4516 void of_clk_del_provider(struct device_node *np)
4518 struct of_clk_provider *cp;
4520 mutex_lock(&of_clk_mutex);
4521 list_for_each_entry(cp, &of_clk_providers, link) {
4522 if (cp->node == np) {
4523 list_del(&cp->link);
4524 of_node_put(cp->node);
4529 mutex_unlock(&of_clk_mutex);
4531 EXPORT_SYMBOL_GPL(of_clk_del_provider);
4533 static int devm_clk_provider_match(struct device *dev, void *res, void *data)
4535 struct device_node **np = res;
4537 if (WARN_ON(!np || !*np))
4544 * devm_of_clk_del_provider() - Remove clock provider registered using devm
4545 * @dev: Device to whose lifetime the clock provider was bound
4547 void devm_of_clk_del_provider(struct device *dev)
4550 struct device_node *np = get_clk_provider_node(dev);
4552 ret = devres_release(dev, devm_of_clk_release_provider,
4553 devm_clk_provider_match, np);
4557 EXPORT_SYMBOL(devm_of_clk_del_provider);
4560 * of_parse_clkspec() - Parse a DT clock specifier for a given device node
4561 * @np: device node to parse clock specifier from
4562 * @index: index of phandle to parse clock out of. If index < 0, @name is used
4563 * @name: clock name to find and parse. If name is NULL, the index is used
4564 * @out_args: Result of parsing the clock specifier
4566 * Parses a device node's "clocks" and "clock-names" properties to find the
4567 * phandle and cells for the index or name that is desired. The resulting clock
4568 * specifier is placed into @out_args, or an errno is returned when there's a
4569 * parsing error. The @index argument is ignored if @name is non-NULL.
4573 * phandle1: clock-controller@1 {
4574 * #clock-cells = <2>;
4577 * phandle2: clock-controller@2 {
4578 * #clock-cells = <1>;
4581 * clock-consumer@3 {
4582 * clocks = <&phandle1 1 2 &phandle2 3>;
4583 * clock-names = "name1", "name2";
4586 * To get a device_node for `clock-controller@2' node you may call this
4587 * function a few different ways:
4589 * of_parse_clkspec(clock-consumer@3, -1, "name2", &args);
4590 * of_parse_clkspec(clock-consumer@3, 1, NULL, &args);
4591 * of_parse_clkspec(clock-consumer@3, 1, "name2", &args);
4593 * Return: 0 upon successfully parsing the clock specifier. Otherwise, -ENOENT
4594 * if @name is NULL or -EINVAL if @name is non-NULL and it can't be found in
4595 * the "clock-names" property of @np.
4597 static int of_parse_clkspec(const struct device_node *np, int index,
4598 const char *name, struct of_phandle_args *out_args)
4602 /* Walk up the tree of devices looking for a clock property that matches */
4605 * For named clocks, first look up the name in the
4606 * "clock-names" property. If it cannot be found, then index
4607 * will be an error code and of_parse_phandle_with_args() will
4611 index = of_property_match_string(np, "clock-names", name);
4612 ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells",
4616 if (name && index >= 0)
4620 * No matching clock found on this node. If the parent node
4621 * has a "clock-ranges" property, then we can try one of its
4625 if (np && !of_get_property(np, "clock-ranges", NULL))
4633 static struct clk_hw *
4634 __of_clk_get_hw_from_provider(struct of_clk_provider *provider,
4635 struct of_phandle_args *clkspec)
4639 if (provider->get_hw)
4640 return provider->get_hw(clkspec, provider->data);
4642 clk = provider->get(clkspec, provider->data);
4644 return ERR_CAST(clk);
4645 return __clk_get_hw(clk);
4648 static struct clk_hw *
4649 of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
4651 struct of_clk_provider *provider;
4652 struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER);
4655 return ERR_PTR(-EINVAL);
4657 mutex_lock(&of_clk_mutex);
4658 list_for_each_entry(provider, &of_clk_providers, link) {
4659 if (provider->node == clkspec->np) {
4660 hw = __of_clk_get_hw_from_provider(provider, clkspec);
4665 mutex_unlock(&of_clk_mutex);
4671 * of_clk_get_from_provider() - Lookup a clock from a clock provider
4672 * @clkspec: pointer to a clock specifier data structure
4674 * This function looks up a struct clk from the registered list of clock
4675 * providers, an input is a clock specifier data structure as returned
4676 * from the of_parse_phandle_with_args() function call.
4678 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
4680 struct clk_hw *hw = of_clk_get_hw_from_clkspec(clkspec);
4682 return clk_hw_create_clk(NULL, hw, NULL, __func__);
4684 EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
4686 struct clk_hw *of_clk_get_hw(struct device_node *np, int index,
4691 struct of_phandle_args clkspec;
4693 ret = of_parse_clkspec(np, index, con_id, &clkspec);
4695 return ERR_PTR(ret);
4697 hw = of_clk_get_hw_from_clkspec(&clkspec);
4698 of_node_put(clkspec.np);
4703 static struct clk *__of_clk_get(struct device_node *np,
4704 int index, const char *dev_id,
4707 struct clk_hw *hw = of_clk_get_hw(np, index, con_id);
4709 return clk_hw_create_clk(NULL, hw, dev_id, con_id);
4712 struct clk *of_clk_get(struct device_node *np, int index)
4714 return __of_clk_get(np, index, np->full_name, NULL);
4716 EXPORT_SYMBOL(of_clk_get);
4719 * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
4720 * @np: pointer to clock consumer node
4721 * @name: name of consumer's clock input, or NULL for the first clock reference
4723 * This function parses the clocks and clock-names properties,
4724 * and uses them to look up the struct clk from the registered list of clock
4727 struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
4730 return ERR_PTR(-ENOENT);
4732 return __of_clk_get(np, 0, np->full_name, name);
4734 EXPORT_SYMBOL(of_clk_get_by_name);
4737 * of_clk_get_parent_count() - Count the number of clocks a device node has
4738 * @np: device node to count
4740 * Returns: The number of clocks that are possible parents of this node
4742 unsigned int of_clk_get_parent_count(const struct device_node *np)
4746 count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
4752 EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
4754 const char *of_clk_get_parent_name(const struct device_node *np, int index)
4756 struct of_phandle_args clkspec;
4757 struct property *prop;
4758 const char *clk_name;
4765 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
4770 index = clkspec.args_count ? clkspec.args[0] : 0;
4773 /* if there is an indices property, use it to transfer the index
4774 * specified into an array offset for the clock-output-names property.
4776 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
4783 /* We went off the end of 'clock-indices' without finding it */
4787 if (of_property_read_string_index(clkspec.np, "clock-output-names",
4791 * Best effort to get the name if the clock has been
4792 * registered with the framework. If the clock isn't
4793 * registered, we return the node name as the name of
4794 * the clock as long as #clock-cells = 0.
4796 clk = of_clk_get_from_provider(&clkspec);
4798 if (clkspec.args_count == 0)
4799 clk_name = clkspec.np->name;
4803 clk_name = __clk_get_name(clk);
4809 of_node_put(clkspec.np);
4812 EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
4815 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
4817 * @np: Device node pointer associated with clock provider
4818 * @parents: pointer to char array that hold the parents' names
4819 * @size: size of the @parents array
4821 * Return: number of parents for the clock node.
4823 int of_clk_parent_fill(struct device_node *np, const char **parents,
4828 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
4833 EXPORT_SYMBOL_GPL(of_clk_parent_fill);
4835 struct clock_provider {
4836 void (*clk_init_cb)(struct device_node *);
4837 struct device_node *np;
4838 struct list_head node;
4842 * This function looks for a parent clock. If there is one, then it
4843 * checks that the provider for this parent clock was initialized, in
4844 * this case the parent clock will be ready.
4846 static int parent_ready(struct device_node *np)
4851 struct clk *clk = of_clk_get(np, i);
4853 /* this parent is ready we can check the next one */
4860 /* at least one parent is not ready, we exit now */
4861 if (PTR_ERR(clk) == -EPROBE_DEFER)
4865 * Here we make assumption that the device tree is
4866 * written correctly. So an error means that there is
4867 * no more parent. As we didn't exit yet, then the
4868 * previous parent are ready. If there is no clock
4869 * parent, no need to wait for them, then we can
4870 * consider their absence as being ready
4877 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
4878 * @np: Device node pointer associated with clock provider
4879 * @index: clock index
4880 * @flags: pointer to top-level framework flags
4882 * Detects if the clock-critical property exists and, if so, sets the
4883 * corresponding CLK_IS_CRITICAL flag.
4885 * Do not use this function. It exists only for legacy Device Tree
4886 * bindings, such as the one-clock-per-node style that are outdated.
4887 * Those bindings typically put all clock data into .dts and the Linux
4888 * driver has no clock data, thus making it impossible to set this flag
4889 * correctly from the driver. Only those drivers may call
4890 * of_clk_detect_critical from their setup functions.
4892 * Return: error code or zero on success
4894 int of_clk_detect_critical(struct device_node *np, int index,
4895 unsigned long *flags)
4897 struct property *prop;
4904 of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
4906 *flags |= CLK_IS_CRITICAL;
4912 * of_clk_init() - Scan and init clock providers from the DT
4913 * @matches: array of compatible values and init functions for providers.
4915 * This function scans the device tree for matching clock providers
4916 * and calls their initialization functions. It also does it by trying
4917 * to follow the dependencies.
4919 void __init of_clk_init(const struct of_device_id *matches)
4921 const struct of_device_id *match;
4922 struct device_node *np;
4923 struct clock_provider *clk_provider, *next;
4926 LIST_HEAD(clk_provider_list);
4929 matches = &__clk_of_table;
4931 /* First prepare the list of the clocks providers */
4932 for_each_matching_node_and_match(np, matches, &match) {
4933 struct clock_provider *parent;
4935 if (!of_device_is_available(np))
4938 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
4940 list_for_each_entry_safe(clk_provider, next,
4941 &clk_provider_list, node) {
4942 list_del(&clk_provider->node);
4943 of_node_put(clk_provider->np);
4944 kfree(clk_provider);
4950 parent->clk_init_cb = match->data;
4951 parent->np = of_node_get(np);
4952 list_add_tail(&parent->node, &clk_provider_list);
4955 while (!list_empty(&clk_provider_list)) {
4956 is_init_done = false;
4957 list_for_each_entry_safe(clk_provider, next,
4958 &clk_provider_list, node) {
4959 if (force || parent_ready(clk_provider->np)) {
4961 /* Don't populate platform devices */
4962 of_node_set_flag(clk_provider->np,
4965 clk_provider->clk_init_cb(clk_provider->np);
4966 of_clk_set_defaults(clk_provider->np, true);
4968 list_del(&clk_provider->node);
4969 of_node_put(clk_provider->np);
4970 kfree(clk_provider);
4971 is_init_done = true;
4976 * We didn't manage to initialize any of the
4977 * remaining providers during the last loop, so now we
4978 * initialize all the remaining ones unconditionally
4979 * in case the clock parent was not mandatory