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 const 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)
111 if (!core->rpm_enabled)
114 return pm_runtime_resume_and_get(core->dev);
117 static void clk_pm_runtime_put(struct clk_core *core)
119 if (!core->rpm_enabled)
122 pm_runtime_put_sync(core->dev);
126 static void clk_prepare_lock(void)
128 if (!mutex_trylock(&prepare_lock)) {
129 if (prepare_owner == current) {
133 mutex_lock(&prepare_lock);
135 WARN_ON_ONCE(prepare_owner != NULL);
136 WARN_ON_ONCE(prepare_refcnt != 0);
137 prepare_owner = current;
141 static void clk_prepare_unlock(void)
143 WARN_ON_ONCE(prepare_owner != current);
144 WARN_ON_ONCE(prepare_refcnt == 0);
146 if (--prepare_refcnt)
148 prepare_owner = NULL;
149 mutex_unlock(&prepare_lock);
152 static unsigned long clk_enable_lock(void)
153 __acquires(enable_lock)
158 * On UP systems, spin_trylock_irqsave() always returns true, even if
159 * we already hold the lock. So, in that case, we rely only on
160 * reference counting.
162 if (!IS_ENABLED(CONFIG_SMP) ||
163 !spin_trylock_irqsave(&enable_lock, flags)) {
164 if (enable_owner == current) {
166 __acquire(enable_lock);
167 if (!IS_ENABLED(CONFIG_SMP))
168 local_save_flags(flags);
171 spin_lock_irqsave(&enable_lock, flags);
173 WARN_ON_ONCE(enable_owner != NULL);
174 WARN_ON_ONCE(enable_refcnt != 0);
175 enable_owner = current;
180 static void clk_enable_unlock(unsigned long flags)
181 __releases(enable_lock)
183 WARN_ON_ONCE(enable_owner != current);
184 WARN_ON_ONCE(enable_refcnt == 0);
186 if (--enable_refcnt) {
187 __release(enable_lock);
191 spin_unlock_irqrestore(&enable_lock, flags);
194 static bool clk_core_rate_is_protected(struct clk_core *core)
196 return core->protect_count;
199 static bool clk_core_is_prepared(struct clk_core *core)
204 * .is_prepared is optional for clocks that can prepare
205 * fall back to software usage counter if it is missing
207 if (!core->ops->is_prepared)
208 return core->prepare_count;
210 if (!clk_pm_runtime_get(core)) {
211 ret = core->ops->is_prepared(core->hw);
212 clk_pm_runtime_put(core);
218 static bool clk_core_is_enabled(struct clk_core *core)
223 * .is_enabled is only mandatory for clocks that gate
224 * fall back to software usage counter if .is_enabled is missing
226 if (!core->ops->is_enabled)
227 return core->enable_count;
230 * Check if clock controller's device is runtime active before
231 * calling .is_enabled callback. If not, assume that clock is
232 * disabled, because we might be called from atomic context, from
233 * which pm_runtime_get() is not allowed.
234 * This function is called mainly from clk_disable_unused_subtree,
235 * which ensures proper runtime pm activation of controller before
236 * taking enable spinlock, but the below check is needed if one tries
237 * to call it from other places.
239 if (core->rpm_enabled) {
240 pm_runtime_get_noresume(core->dev);
241 if (!pm_runtime_active(core->dev)) {
248 * This could be called with the enable lock held, or from atomic
249 * context. If the parent isn't enabled already, we can't do
250 * anything here. We can also assume this clock isn't enabled.
252 if ((core->flags & CLK_OPS_PARENT_ENABLE) && core->parent)
253 if (!clk_core_is_enabled(core->parent)) {
258 ret = core->ops->is_enabled(core->hw);
260 if (core->rpm_enabled)
261 pm_runtime_put(core->dev);
266 /*** helper functions ***/
268 const char *__clk_get_name(const struct clk *clk)
270 return !clk ? NULL : clk->core->name;
272 EXPORT_SYMBOL_GPL(__clk_get_name);
274 const char *clk_hw_get_name(const struct clk_hw *hw)
276 return hw->core->name;
278 EXPORT_SYMBOL_GPL(clk_hw_get_name);
280 struct clk_hw *__clk_get_hw(struct clk *clk)
282 return !clk ? NULL : clk->core->hw;
284 EXPORT_SYMBOL_GPL(__clk_get_hw);
286 unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
288 return hw->core->num_parents;
290 EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
292 struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
294 return hw->core->parent ? hw->core->parent->hw : NULL;
296 EXPORT_SYMBOL_GPL(clk_hw_get_parent);
298 static struct clk_core *__clk_lookup_subtree(const char *name,
299 struct clk_core *core)
301 struct clk_core *child;
302 struct clk_core *ret;
304 if (!strcmp(core->name, name))
307 hlist_for_each_entry(child, &core->children, child_node) {
308 ret = __clk_lookup_subtree(name, child);
316 static struct clk_core *clk_core_lookup(const char *name)
318 struct clk_core *root_clk;
319 struct clk_core *ret;
324 /* search the 'proper' clk tree first */
325 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
326 ret = __clk_lookup_subtree(name, root_clk);
331 /* if not found, then search the orphan tree */
332 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
333 ret = __clk_lookup_subtree(name, root_clk);
342 static int of_parse_clkspec(const struct device_node *np, int index,
343 const char *name, struct of_phandle_args *out_args);
344 static struct clk_hw *
345 of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec);
347 static inline int of_parse_clkspec(const struct device_node *np, int index,
349 struct of_phandle_args *out_args)
353 static inline struct clk_hw *
354 of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
356 return ERR_PTR(-ENOENT);
361 * clk_core_get - Find the clk_core parent of a clk
362 * @core: clk to find parent of
363 * @p_index: parent index to search for
365 * This is the preferred method for clk providers to find the parent of a
366 * clk when that parent is external to the clk controller. The parent_names
367 * array is indexed and treated as a local name matching a string in the device
368 * node's 'clock-names' property or as the 'con_id' matching the device's
369 * dev_name() in a clk_lookup. This allows clk providers to use their own
370 * namespace instead of looking for a globally unique parent string.
372 * For example the following DT snippet would allow a clock registered by the
373 * clock-controller@c001 that has a clk_init_data::parent_data array
374 * with 'xtal' in the 'name' member to find the clock provided by the
375 * clock-controller@f00abcd without needing to get the globally unique name of
378 * parent: clock-controller@f00abcd {
379 * reg = <0xf00abcd 0xabcd>;
380 * #clock-cells = <0>;
383 * clock-controller@c001 {
384 * reg = <0xc001 0xf00d>;
385 * clocks = <&parent>;
386 * clock-names = "xtal";
387 * #clock-cells = <1>;
390 * Returns: -ENOENT when the provider can't be found or the clk doesn't
391 * exist in the provider or the name can't be found in the DT node or
392 * in a clkdev lookup. NULL when the provider knows about the clk but it
393 * isn't provided on this system.
394 * A valid clk_core pointer when the clk can be found in the provider.
396 static struct clk_core *clk_core_get(struct clk_core *core, u8 p_index)
398 const char *name = core->parents[p_index].fw_name;
399 int index = core->parents[p_index].index;
400 struct clk_hw *hw = ERR_PTR(-ENOENT);
401 struct device *dev = core->dev;
402 const char *dev_id = dev ? dev_name(dev) : NULL;
403 struct device_node *np = core->of_node;
404 struct of_phandle_args clkspec;
406 if (np && (name || index >= 0) &&
407 !of_parse_clkspec(np, index, name, &clkspec)) {
408 hw = of_clk_get_hw_from_clkspec(&clkspec);
409 of_node_put(clkspec.np);
412 * If the DT search above couldn't find the provider fallback to
413 * looking up via clkdev based clk_lookups.
415 hw = clk_find_hw(dev_id, name);
427 static void clk_core_fill_parent_index(struct clk_core *core, u8 index)
429 struct clk_parent_map *entry = &core->parents[index];
430 struct clk_core *parent;
433 parent = entry->hw->core;
435 parent = clk_core_get(core, index);
436 if (PTR_ERR(parent) == -ENOENT && entry->name)
437 parent = clk_core_lookup(entry->name);
441 * We have a direct reference but it isn't registered yet?
442 * Orphan it and let clk_reparent() update the orphan status
443 * when the parent is registered.
446 parent = ERR_PTR(-EPROBE_DEFER);
448 /* Only cache it if it's not an error */
450 entry->core = parent;
453 static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
456 if (!core || index >= core->num_parents || !core->parents)
459 if (!core->parents[index].core)
460 clk_core_fill_parent_index(core, index);
462 return core->parents[index].core;
466 clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
468 struct clk_core *parent;
470 parent = clk_core_get_parent_by_index(hw->core, index);
472 return !parent ? NULL : parent->hw;
474 EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
476 unsigned int __clk_get_enable_count(struct clk *clk)
478 return !clk ? 0 : clk->core->enable_count;
481 static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
486 if (!core->num_parents || core->parent)
490 * Clk must have a parent because num_parents > 0 but the parent isn't
491 * known yet. Best to return 0 as the rate of this clk until we can
492 * properly recalc the rate based on the parent's rate.
497 unsigned long clk_hw_get_rate(const struct clk_hw *hw)
499 return clk_core_get_rate_nolock(hw->core);
501 EXPORT_SYMBOL_GPL(clk_hw_get_rate);
503 static unsigned long clk_core_get_accuracy_no_lock(struct clk_core *core)
508 return core->accuracy;
511 unsigned long clk_hw_get_flags(const struct clk_hw *hw)
513 return hw->core->flags;
515 EXPORT_SYMBOL_GPL(clk_hw_get_flags);
517 bool clk_hw_is_prepared(const struct clk_hw *hw)
519 return clk_core_is_prepared(hw->core);
521 EXPORT_SYMBOL_GPL(clk_hw_is_prepared);
523 bool clk_hw_rate_is_protected(const struct clk_hw *hw)
525 return clk_core_rate_is_protected(hw->core);
527 EXPORT_SYMBOL_GPL(clk_hw_rate_is_protected);
529 bool clk_hw_is_enabled(const struct clk_hw *hw)
531 return clk_core_is_enabled(hw->core);
533 EXPORT_SYMBOL_GPL(clk_hw_is_enabled);
535 bool __clk_is_enabled(struct clk *clk)
540 return clk_core_is_enabled(clk->core);
542 EXPORT_SYMBOL_GPL(__clk_is_enabled);
544 static bool mux_is_better_rate(unsigned long rate, unsigned long now,
545 unsigned long best, unsigned long flags)
547 if (flags & CLK_MUX_ROUND_CLOSEST)
548 return abs(now - rate) < abs(best - rate);
550 return now <= rate && now > best;
553 static void clk_core_init_rate_req(struct clk_core * const core,
554 struct clk_rate_request *req,
557 static int clk_core_round_rate_nolock(struct clk_core *core,
558 struct clk_rate_request *req);
560 static bool clk_core_has_parent(struct clk_core *core, const struct clk_core *parent)
562 struct clk_core *tmp;
565 /* Optimize for the case where the parent is already the parent. */
566 if (core->parent == parent)
569 for (i = 0; i < core->num_parents; i++) {
570 tmp = clk_core_get_parent_by_index(core, i);
582 clk_core_forward_rate_req(struct clk_core *core,
583 const struct clk_rate_request *old_req,
584 struct clk_core *parent,
585 struct clk_rate_request *req,
586 unsigned long parent_rate)
588 if (WARN_ON(!clk_core_has_parent(core, parent)))
591 clk_core_init_rate_req(parent, req, parent_rate);
593 if (req->min_rate < old_req->min_rate)
594 req->min_rate = old_req->min_rate;
596 if (req->max_rate > old_req->max_rate)
597 req->max_rate = old_req->max_rate;
601 clk_core_determine_rate_no_reparent(struct clk_hw *hw,
602 struct clk_rate_request *req)
604 struct clk_core *core = hw->core;
605 struct clk_core *parent = core->parent;
609 if (core->flags & CLK_SET_RATE_PARENT) {
610 struct clk_rate_request parent_req;
617 clk_core_forward_rate_req(core, req, parent, &parent_req,
620 trace_clk_rate_request_start(&parent_req);
622 ret = clk_core_round_rate_nolock(parent, &parent_req);
626 trace_clk_rate_request_done(&parent_req);
628 best = parent_req.rate;
630 best = clk_core_get_rate_nolock(parent);
632 best = clk_core_get_rate_nolock(core);
635 req->best_parent_rate = best;
641 int clk_mux_determine_rate_flags(struct clk_hw *hw,
642 struct clk_rate_request *req,
645 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
646 int i, num_parents, ret;
647 unsigned long best = 0;
649 /* if NO_REPARENT flag set, pass through to current parent */
650 if (core->flags & CLK_SET_RATE_NO_REPARENT)
651 return clk_core_determine_rate_no_reparent(hw, req);
653 /* find the parent that can provide the fastest rate <= rate */
654 num_parents = core->num_parents;
655 for (i = 0; i < num_parents; i++) {
656 unsigned long parent_rate;
658 parent = clk_core_get_parent_by_index(core, i);
662 if (core->flags & CLK_SET_RATE_PARENT) {
663 struct clk_rate_request parent_req;
665 clk_core_forward_rate_req(core, req, parent, &parent_req, req->rate);
667 trace_clk_rate_request_start(&parent_req);
669 ret = clk_core_round_rate_nolock(parent, &parent_req);
673 trace_clk_rate_request_done(&parent_req);
675 parent_rate = parent_req.rate;
677 parent_rate = clk_core_get_rate_nolock(parent);
680 if (mux_is_better_rate(req->rate, parent_rate,
682 best_parent = parent;
690 req->best_parent_hw = best_parent->hw;
691 req->best_parent_rate = best;
696 EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);
698 struct clk *__clk_lookup(const char *name)
700 struct clk_core *core = clk_core_lookup(name);
702 return !core ? NULL : core->hw->clk;
705 static void clk_core_get_boundaries(struct clk_core *core,
706 unsigned long *min_rate,
707 unsigned long *max_rate)
709 struct clk *clk_user;
711 lockdep_assert_held(&prepare_lock);
713 *min_rate = core->min_rate;
714 *max_rate = core->max_rate;
716 hlist_for_each_entry(clk_user, &core->clks, clks_node)
717 *min_rate = max(*min_rate, clk_user->min_rate);
719 hlist_for_each_entry(clk_user, &core->clks, clks_node)
720 *max_rate = min(*max_rate, clk_user->max_rate);
724 * clk_hw_get_rate_range() - returns the clock rate range for a hw clk
725 * @hw: the hw clk we want to get the range from
726 * @min_rate: pointer to the variable that will hold the minimum
727 * @max_rate: pointer to the variable that will hold the maximum
729 * Fills the @min_rate and @max_rate variables with the minimum and
730 * maximum that clock can reach.
732 void clk_hw_get_rate_range(struct clk_hw *hw, unsigned long *min_rate,
733 unsigned long *max_rate)
735 clk_core_get_boundaries(hw->core, min_rate, max_rate);
737 EXPORT_SYMBOL_GPL(clk_hw_get_rate_range);
739 static bool clk_core_check_boundaries(struct clk_core *core,
740 unsigned long min_rate,
741 unsigned long max_rate)
745 lockdep_assert_held(&prepare_lock);
747 if (min_rate > core->max_rate || max_rate < core->min_rate)
750 hlist_for_each_entry(user, &core->clks, clks_node)
751 if (min_rate > user->max_rate || max_rate < user->min_rate)
757 void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
758 unsigned long max_rate)
760 hw->core->min_rate = min_rate;
761 hw->core->max_rate = max_rate;
763 EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
766 * __clk_mux_determine_rate - clk_ops::determine_rate implementation for a mux type clk
767 * @hw: mux type clk to determine rate on
768 * @req: rate request, also used to return preferred parent and frequencies
770 * Helper for finding best parent to provide a given frequency. This can be used
771 * directly as a determine_rate callback (e.g. for a mux), or from a more
772 * complex clock that may combine a mux with other operations.
774 * Returns: 0 on success, -EERROR value on error
776 int __clk_mux_determine_rate(struct clk_hw *hw,
777 struct clk_rate_request *req)
779 return clk_mux_determine_rate_flags(hw, req, 0);
781 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
783 int __clk_mux_determine_rate_closest(struct clk_hw *hw,
784 struct clk_rate_request *req)
786 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
788 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
791 * clk_hw_determine_rate_no_reparent - clk_ops::determine_rate implementation for a clk that doesn't reparent
792 * @hw: mux type clk to determine rate on
793 * @req: rate request, also used to return preferred frequency
795 * Helper for finding best parent rate to provide a given frequency.
796 * This can be used directly as a determine_rate callback (e.g. for a
797 * mux), or from a more complex clock that may combine a mux with other
800 * Returns: 0 on success, -EERROR value on error
802 int clk_hw_determine_rate_no_reparent(struct clk_hw *hw,
803 struct clk_rate_request *req)
805 return clk_core_determine_rate_no_reparent(hw, req);
807 EXPORT_SYMBOL_GPL(clk_hw_determine_rate_no_reparent);
811 static void clk_core_rate_unprotect(struct clk_core *core)
813 lockdep_assert_held(&prepare_lock);
818 if (WARN(core->protect_count == 0,
819 "%s already unprotected\n", core->name))
822 if (--core->protect_count > 0)
825 clk_core_rate_unprotect(core->parent);
828 static int clk_core_rate_nuke_protect(struct clk_core *core)
832 lockdep_assert_held(&prepare_lock);
837 if (core->protect_count == 0)
840 ret = core->protect_count;
841 core->protect_count = 1;
842 clk_core_rate_unprotect(core);
848 * clk_rate_exclusive_put - release exclusivity over clock rate control
849 * @clk: the clk over which the exclusivity is released
851 * clk_rate_exclusive_put() completes a critical section during which a clock
852 * consumer cannot tolerate any other consumer making any operation on the
853 * clock which could result in a rate change or rate glitch. Exclusive clocks
854 * cannot have their rate changed, either directly or indirectly due to changes
855 * further up the parent chain of clocks. As a result, clocks up parent chain
856 * also get under exclusive control of the calling consumer.
858 * If exlusivity is claimed more than once on clock, even by the same consumer,
859 * the rate effectively gets locked as exclusivity can't be preempted.
861 * Calls to clk_rate_exclusive_put() must be balanced with calls to
862 * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
865 void clk_rate_exclusive_put(struct clk *clk)
873 * if there is something wrong with this consumer protect count, stop
874 * here before messing with the provider
876 if (WARN_ON(clk->exclusive_count <= 0))
879 clk_core_rate_unprotect(clk->core);
880 clk->exclusive_count--;
882 clk_prepare_unlock();
884 EXPORT_SYMBOL_GPL(clk_rate_exclusive_put);
886 static void clk_core_rate_protect(struct clk_core *core)
888 lockdep_assert_held(&prepare_lock);
893 if (core->protect_count == 0)
894 clk_core_rate_protect(core->parent);
896 core->protect_count++;
899 static void clk_core_rate_restore_protect(struct clk_core *core, int count)
901 lockdep_assert_held(&prepare_lock);
909 clk_core_rate_protect(core);
910 core->protect_count = count;
914 * clk_rate_exclusive_get - get exclusivity over the clk rate control
915 * @clk: the clk over which the exclusity of rate control is requested
917 * clk_rate_exclusive_get() begins a critical section during which a clock
918 * consumer cannot tolerate any other consumer making any operation on the
919 * clock which could result in a rate change or rate glitch. Exclusive clocks
920 * cannot have their rate changed, either directly or indirectly due to changes
921 * further up the parent chain of clocks. As a result, clocks up parent chain
922 * also get under exclusive control of the calling consumer.
924 * If exlusivity is claimed more than once on clock, even by the same consumer,
925 * the rate effectively gets locked as exclusivity can't be preempted.
927 * Calls to clk_rate_exclusive_get() should be balanced with calls to
928 * clk_rate_exclusive_put(). Calls to this function may sleep.
929 * Returns 0 on success, -EERROR otherwise
931 int clk_rate_exclusive_get(struct clk *clk)
937 clk_core_rate_protect(clk->core);
938 clk->exclusive_count++;
939 clk_prepare_unlock();
943 EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
945 static void devm_clk_rate_exclusive_put(void *data)
947 struct clk *clk = data;
949 clk_rate_exclusive_put(clk);
952 int devm_clk_rate_exclusive_get(struct device *dev, struct clk *clk)
956 ret = clk_rate_exclusive_get(clk);
960 return devm_add_action_or_reset(dev, devm_clk_rate_exclusive_put, clk);
962 EXPORT_SYMBOL_GPL(devm_clk_rate_exclusive_get);
964 static void clk_core_unprepare(struct clk_core *core)
966 lockdep_assert_held(&prepare_lock);
971 if (WARN(core->prepare_count == 0,
972 "%s already unprepared\n", core->name))
975 if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL,
976 "Unpreparing critical %s\n", core->name))
979 if (core->flags & CLK_SET_RATE_GATE)
980 clk_core_rate_unprotect(core);
982 if (--core->prepare_count > 0)
985 WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);
987 trace_clk_unprepare(core);
989 if (core->ops->unprepare)
990 core->ops->unprepare(core->hw);
992 trace_clk_unprepare_complete(core);
993 clk_core_unprepare(core->parent);
994 clk_pm_runtime_put(core);
997 static void clk_core_unprepare_lock(struct clk_core *core)
1000 clk_core_unprepare(core);
1001 clk_prepare_unlock();
1005 * clk_unprepare - undo preparation of a clock source
1006 * @clk: the clk being unprepared
1008 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
1009 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
1010 * if the operation may sleep. One example is a clk which is accessed over
1011 * I2c. In the complex case a clk gate operation may require a fast and a slow
1012 * part. It is this reason that clk_unprepare and clk_disable are not mutually
1013 * exclusive. In fact clk_disable must be called before clk_unprepare.
1015 void clk_unprepare(struct clk *clk)
1017 if (IS_ERR_OR_NULL(clk))
1020 clk_core_unprepare_lock(clk->core);
1022 EXPORT_SYMBOL_GPL(clk_unprepare);
1024 static int clk_core_prepare(struct clk_core *core)
1028 lockdep_assert_held(&prepare_lock);
1033 if (core->prepare_count == 0) {
1034 ret = clk_pm_runtime_get(core);
1038 ret = clk_core_prepare(core->parent);
1042 trace_clk_prepare(core);
1044 if (core->ops->prepare)
1045 ret = core->ops->prepare(core->hw);
1047 trace_clk_prepare_complete(core);
1053 core->prepare_count++;
1056 * CLK_SET_RATE_GATE is a special case of clock protection
1057 * Instead of a consumer claiming exclusive rate control, it is
1058 * actually the provider which prevents any consumer from making any
1059 * operation which could result in a rate change or rate glitch while
1060 * the clock is prepared.
1062 if (core->flags & CLK_SET_RATE_GATE)
1063 clk_core_rate_protect(core);
1067 clk_core_unprepare(core->parent);
1069 clk_pm_runtime_put(core);
1073 static int clk_core_prepare_lock(struct clk_core *core)
1078 ret = clk_core_prepare(core);
1079 clk_prepare_unlock();
1085 * clk_prepare - prepare a clock source
1086 * @clk: the clk being prepared
1088 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
1089 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
1090 * operation may sleep. One example is a clk which is accessed over I2c. In
1091 * the complex case a clk ungate operation may require a fast and a slow part.
1092 * It is this reason that clk_prepare and clk_enable are not mutually
1093 * exclusive. In fact clk_prepare must be called before clk_enable.
1094 * Returns 0 on success, -EERROR otherwise.
1096 int clk_prepare(struct clk *clk)
1101 return clk_core_prepare_lock(clk->core);
1103 EXPORT_SYMBOL_GPL(clk_prepare);
1105 static void clk_core_disable(struct clk_core *core)
1107 lockdep_assert_held(&enable_lock);
1112 if (WARN(core->enable_count == 0, "%s already disabled\n", core->name))
1115 if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL,
1116 "Disabling critical %s\n", core->name))
1119 if (--core->enable_count > 0)
1122 trace_clk_disable(core);
1124 if (core->ops->disable)
1125 core->ops->disable(core->hw);
1127 trace_clk_disable_complete(core);
1129 clk_core_disable(core->parent);
1132 static void clk_core_disable_lock(struct clk_core *core)
1134 unsigned long flags;
1136 flags = clk_enable_lock();
1137 clk_core_disable(core);
1138 clk_enable_unlock(flags);
1142 * clk_disable - gate a clock
1143 * @clk: the clk being gated
1145 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
1146 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
1147 * clk if the operation is fast and will never sleep. One example is a
1148 * SoC-internal clk which is controlled via simple register writes. In the
1149 * complex case a clk gate operation may require a fast and a slow part. It is
1150 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
1151 * In fact clk_disable must be called before clk_unprepare.
1153 void clk_disable(struct clk *clk)
1155 if (IS_ERR_OR_NULL(clk))
1158 clk_core_disable_lock(clk->core);
1160 EXPORT_SYMBOL_GPL(clk_disable);
1162 static int clk_core_enable(struct clk_core *core)
1166 lockdep_assert_held(&enable_lock);
1171 if (WARN(core->prepare_count == 0,
1172 "Enabling unprepared %s\n", core->name))
1175 if (core->enable_count == 0) {
1176 ret = clk_core_enable(core->parent);
1181 trace_clk_enable(core);
1183 if (core->ops->enable)
1184 ret = core->ops->enable(core->hw);
1186 trace_clk_enable_complete(core);
1189 clk_core_disable(core->parent);
1194 core->enable_count++;
1198 static int clk_core_enable_lock(struct clk_core *core)
1200 unsigned long flags;
1203 flags = clk_enable_lock();
1204 ret = clk_core_enable(core);
1205 clk_enable_unlock(flags);
1211 * clk_gate_restore_context - restore context for poweroff
1212 * @hw: the clk_hw pointer of clock whose state is to be restored
1214 * The clock gate restore context function enables or disables
1215 * the gate clocks based on the enable_count. This is done in cases
1216 * where the clock context is lost and based on the enable_count
1217 * the clock either needs to be enabled/disabled. This
1218 * helps restore the state of gate clocks.
1220 void clk_gate_restore_context(struct clk_hw *hw)
1222 struct clk_core *core = hw->core;
1224 if (core->enable_count)
1225 core->ops->enable(hw);
1227 core->ops->disable(hw);
1229 EXPORT_SYMBOL_GPL(clk_gate_restore_context);
1231 static int clk_core_save_context(struct clk_core *core)
1233 struct clk_core *child;
1236 hlist_for_each_entry(child, &core->children, child_node) {
1237 ret = clk_core_save_context(child);
1242 if (core->ops && core->ops->save_context)
1243 ret = core->ops->save_context(core->hw);
1248 static void clk_core_restore_context(struct clk_core *core)
1250 struct clk_core *child;
1252 if (core->ops && core->ops->restore_context)
1253 core->ops->restore_context(core->hw);
1255 hlist_for_each_entry(child, &core->children, child_node)
1256 clk_core_restore_context(child);
1260 * clk_save_context - save clock context for poweroff
1262 * Saves the context of the clock register for powerstates in which the
1263 * contents of the registers will be lost. Occurs deep within the suspend
1264 * code. Returns 0 on success.
1266 int clk_save_context(void)
1268 struct clk_core *clk;
1271 hlist_for_each_entry(clk, &clk_root_list, child_node) {
1272 ret = clk_core_save_context(clk);
1277 hlist_for_each_entry(clk, &clk_orphan_list, child_node) {
1278 ret = clk_core_save_context(clk);
1285 EXPORT_SYMBOL_GPL(clk_save_context);
1288 * clk_restore_context - restore clock context after poweroff
1290 * Restore the saved clock context upon resume.
1293 void clk_restore_context(void)
1295 struct clk_core *core;
1297 hlist_for_each_entry(core, &clk_root_list, child_node)
1298 clk_core_restore_context(core);
1300 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1301 clk_core_restore_context(core);
1303 EXPORT_SYMBOL_GPL(clk_restore_context);
1306 * clk_enable - ungate a clock
1307 * @clk: the clk being ungated
1309 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
1310 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
1311 * if the operation will never sleep. One example is a SoC-internal clk which
1312 * is controlled via simple register writes. In the complex case a clk ungate
1313 * operation may require a fast and a slow part. It is this reason that
1314 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
1315 * must be called before clk_enable. Returns 0 on success, -EERROR
1318 int clk_enable(struct clk *clk)
1323 return clk_core_enable_lock(clk->core);
1325 EXPORT_SYMBOL_GPL(clk_enable);
1328 * clk_is_enabled_when_prepared - indicate if preparing a clock also enables it.
1329 * @clk: clock source
1331 * Returns true if clk_prepare() implicitly enables the clock, effectively
1332 * making clk_enable()/clk_disable() no-ops, false otherwise.
1334 * This is of interest mainly to power management code where actually
1335 * disabling the clock also requires unpreparing it to have any material
1338 * Regardless of the value returned here, the caller must always invoke
1339 * clk_enable() or clk_prepare_enable() and counterparts for usage counts
1342 bool clk_is_enabled_when_prepared(struct clk *clk)
1344 return clk && !(clk->core->ops->enable && clk->core->ops->disable);
1346 EXPORT_SYMBOL_GPL(clk_is_enabled_when_prepared);
1348 static int clk_core_prepare_enable(struct clk_core *core)
1352 ret = clk_core_prepare_lock(core);
1356 ret = clk_core_enable_lock(core);
1358 clk_core_unprepare_lock(core);
1363 static void clk_core_disable_unprepare(struct clk_core *core)
1365 clk_core_disable_lock(core);
1366 clk_core_unprepare_lock(core);
1369 static void __init clk_unprepare_unused_subtree(struct clk_core *core)
1371 struct clk_core *child;
1373 lockdep_assert_held(&prepare_lock);
1375 hlist_for_each_entry(child, &core->children, child_node)
1376 clk_unprepare_unused_subtree(child);
1378 if (core->prepare_count)
1381 if (core->flags & CLK_IGNORE_UNUSED)
1384 if (clk_pm_runtime_get(core))
1387 if (clk_core_is_prepared(core)) {
1388 trace_clk_unprepare(core);
1389 if (core->ops->unprepare_unused)
1390 core->ops->unprepare_unused(core->hw);
1391 else if (core->ops->unprepare)
1392 core->ops->unprepare(core->hw);
1393 trace_clk_unprepare_complete(core);
1396 clk_pm_runtime_put(core);
1399 static void __init clk_disable_unused_subtree(struct clk_core *core)
1401 struct clk_core *child;
1402 unsigned long flags;
1404 lockdep_assert_held(&prepare_lock);
1406 hlist_for_each_entry(child, &core->children, child_node)
1407 clk_disable_unused_subtree(child);
1409 if (core->flags & CLK_OPS_PARENT_ENABLE)
1410 clk_core_prepare_enable(core->parent);
1412 if (clk_pm_runtime_get(core))
1415 flags = clk_enable_lock();
1417 if (core->enable_count)
1420 if (core->flags & CLK_IGNORE_UNUSED)
1424 * some gate clocks have special needs during the disable-unused
1425 * sequence. call .disable_unused if available, otherwise fall
1428 if (clk_core_is_enabled(core)) {
1429 trace_clk_disable(core);
1430 if (core->ops->disable_unused)
1431 core->ops->disable_unused(core->hw);
1432 else if (core->ops->disable)
1433 core->ops->disable(core->hw);
1434 trace_clk_disable_complete(core);
1438 clk_enable_unlock(flags);
1439 clk_pm_runtime_put(core);
1441 if (core->flags & CLK_OPS_PARENT_ENABLE)
1442 clk_core_disable_unprepare(core->parent);
1445 static bool clk_ignore_unused __initdata;
1446 static int __init clk_ignore_unused_setup(char *__unused)
1448 clk_ignore_unused = true;
1451 __setup("clk_ignore_unused", clk_ignore_unused_setup);
1453 static int __init clk_disable_unused(void)
1455 struct clk_core *core;
1457 if (clk_ignore_unused) {
1458 pr_warn("clk: Not disabling unused clocks\n");
1462 pr_info("clk: Disabling unused clocks\n");
1466 hlist_for_each_entry(core, &clk_root_list, child_node)
1467 clk_disable_unused_subtree(core);
1469 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1470 clk_disable_unused_subtree(core);
1472 hlist_for_each_entry(core, &clk_root_list, child_node)
1473 clk_unprepare_unused_subtree(core);
1475 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1476 clk_unprepare_unused_subtree(core);
1478 clk_prepare_unlock();
1482 late_initcall_sync(clk_disable_unused);
1484 static int clk_core_determine_round_nolock(struct clk_core *core,
1485 struct clk_rate_request *req)
1489 lockdep_assert_held(&prepare_lock);
1495 * Some clock providers hand-craft their clk_rate_requests and
1496 * might not fill min_rate and max_rate.
1498 * If it's the case, clamping the rate is equivalent to setting
1499 * the rate to 0 which is bad. Skip the clamping but complain so
1500 * that it gets fixed, hopefully.
1502 if (!req->min_rate && !req->max_rate)
1503 pr_warn("%s: %s: clk_rate_request has initialized min or max rate.\n",
1504 __func__, core->name);
1506 req->rate = clamp(req->rate, req->min_rate, req->max_rate);
1509 * At this point, core protection will be disabled
1510 * - if the provider is not protected at all
1511 * - if the calling consumer is the only one which has exclusivity
1514 if (clk_core_rate_is_protected(core)) {
1515 req->rate = core->rate;
1516 } else if (core->ops->determine_rate) {
1517 return core->ops->determine_rate(core->hw, req);
1518 } else if (core->ops->round_rate) {
1519 rate = core->ops->round_rate(core->hw, req->rate,
1520 &req->best_parent_rate);
1532 static void clk_core_init_rate_req(struct clk_core * const core,
1533 struct clk_rate_request *req,
1536 struct clk_core *parent;
1541 memset(req, 0, sizeof(*req));
1542 req->max_rate = ULONG_MAX;
1549 clk_core_get_boundaries(core, &req->min_rate, &req->max_rate);
1551 parent = core->parent;
1553 req->best_parent_hw = parent->hw;
1554 req->best_parent_rate = parent->rate;
1556 req->best_parent_hw = NULL;
1557 req->best_parent_rate = 0;
1562 * clk_hw_init_rate_request - Initializes a clk_rate_request
1563 * @hw: the clk for which we want to submit a rate request
1564 * @req: the clk_rate_request structure we want to initialise
1565 * @rate: the rate which is to be requested
1567 * Initializes a clk_rate_request structure to submit to
1568 * __clk_determine_rate() or similar functions.
1570 void clk_hw_init_rate_request(const struct clk_hw *hw,
1571 struct clk_rate_request *req,
1574 if (WARN_ON(!hw || !req))
1577 clk_core_init_rate_req(hw->core, req, rate);
1579 EXPORT_SYMBOL_GPL(clk_hw_init_rate_request);
1582 * clk_hw_forward_rate_request - Forwards a clk_rate_request to a clock's parent
1583 * @hw: the original clock that got the rate request
1584 * @old_req: the original clk_rate_request structure we want to forward
1585 * @parent: the clk we want to forward @old_req to
1586 * @req: the clk_rate_request structure we want to initialise
1587 * @parent_rate: The rate which is to be requested to @parent
1589 * Initializes a clk_rate_request structure to submit to a clock parent
1590 * in __clk_determine_rate() or similar functions.
1592 void clk_hw_forward_rate_request(const struct clk_hw *hw,
1593 const struct clk_rate_request *old_req,
1594 const struct clk_hw *parent,
1595 struct clk_rate_request *req,
1596 unsigned long parent_rate)
1598 if (WARN_ON(!hw || !old_req || !parent || !req))
1601 clk_core_forward_rate_req(hw->core, old_req,
1605 EXPORT_SYMBOL_GPL(clk_hw_forward_rate_request);
1607 static bool clk_core_can_round(struct clk_core * const core)
1609 return core->ops->determine_rate || core->ops->round_rate;
1612 static int clk_core_round_rate_nolock(struct clk_core *core,
1613 struct clk_rate_request *req)
1617 lockdep_assert_held(&prepare_lock);
1624 if (clk_core_can_round(core))
1625 return clk_core_determine_round_nolock(core, req);
1627 if (core->flags & CLK_SET_RATE_PARENT) {
1628 struct clk_rate_request parent_req;
1630 clk_core_forward_rate_req(core, req, core->parent, &parent_req, req->rate);
1632 trace_clk_rate_request_start(&parent_req);
1634 ret = clk_core_round_rate_nolock(core->parent, &parent_req);
1638 trace_clk_rate_request_done(&parent_req);
1640 req->best_parent_rate = parent_req.rate;
1641 req->rate = parent_req.rate;
1646 req->rate = core->rate;
1651 * __clk_determine_rate - get the closest rate actually supported by a clock
1652 * @hw: determine the rate of this clock
1653 * @req: target rate request
1655 * Useful for clk_ops such as .set_rate and .determine_rate.
1657 int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
1664 return clk_core_round_rate_nolock(hw->core, req);
1666 EXPORT_SYMBOL_GPL(__clk_determine_rate);
1669 * clk_hw_round_rate() - round the given rate for a hw clk
1670 * @hw: the hw clk for which we are rounding a rate
1671 * @rate: the rate which is to be rounded
1673 * Takes in a rate as input and rounds it to a rate that the clk can actually
1676 * Context: prepare_lock must be held.
1677 * For clk providers to call from within clk_ops such as .round_rate,
1680 * Return: returns rounded rate of hw clk if clk supports round_rate operation
1681 * else returns the parent rate.
1683 unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
1686 struct clk_rate_request req;
1688 clk_core_init_rate_req(hw->core, &req, rate);
1690 trace_clk_rate_request_start(&req);
1692 ret = clk_core_round_rate_nolock(hw->core, &req);
1696 trace_clk_rate_request_done(&req);
1700 EXPORT_SYMBOL_GPL(clk_hw_round_rate);
1703 * clk_round_rate - round the given rate for a clk
1704 * @clk: the clk for which we are rounding a rate
1705 * @rate: the rate which is to be rounded
1707 * Takes in a rate as input and rounds it to a rate that the clk can actually
1708 * use which is then returned. If clk doesn't support round_rate operation
1709 * then the parent rate is returned.
1711 long clk_round_rate(struct clk *clk, unsigned long rate)
1713 struct clk_rate_request req;
1721 if (clk->exclusive_count)
1722 clk_core_rate_unprotect(clk->core);
1724 clk_core_init_rate_req(clk->core, &req, rate);
1726 trace_clk_rate_request_start(&req);
1728 ret = clk_core_round_rate_nolock(clk->core, &req);
1730 trace_clk_rate_request_done(&req);
1732 if (clk->exclusive_count)
1733 clk_core_rate_protect(clk->core);
1735 clk_prepare_unlock();
1742 EXPORT_SYMBOL_GPL(clk_round_rate);
1745 * __clk_notify - call clk notifier chain
1746 * @core: clk that is changing rate
1747 * @msg: clk notifier type (see include/linux/clk.h)
1748 * @old_rate: old clk rate
1749 * @new_rate: new clk rate
1751 * Triggers a notifier call chain on the clk rate-change notification
1752 * for 'clk'. Passes a pointer to the struct clk and the previous
1753 * and current rates to the notifier callback. Intended to be called by
1754 * internal clock code only. Returns NOTIFY_DONE from the last driver
1755 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1756 * a driver returns that.
1758 static int __clk_notify(struct clk_core *core, unsigned long msg,
1759 unsigned long old_rate, unsigned long new_rate)
1761 struct clk_notifier *cn;
1762 struct clk_notifier_data cnd;
1763 int ret = NOTIFY_DONE;
1765 cnd.old_rate = old_rate;
1766 cnd.new_rate = new_rate;
1768 list_for_each_entry(cn, &clk_notifier_list, node) {
1769 if (cn->clk->core == core) {
1771 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
1773 if (ret & NOTIFY_STOP_MASK)
1782 * __clk_recalc_accuracies
1783 * @core: first clk in the subtree
1785 * Walks the subtree of clks starting with clk and recalculates accuracies as
1786 * it goes. Note that if a clk does not implement the .recalc_accuracy
1787 * callback then it is assumed that the clock will take on the accuracy of its
1790 static void __clk_recalc_accuracies(struct clk_core *core)
1792 unsigned long parent_accuracy = 0;
1793 struct clk_core *child;
1795 lockdep_assert_held(&prepare_lock);
1798 parent_accuracy = core->parent->accuracy;
1800 if (core->ops->recalc_accuracy)
1801 core->accuracy = core->ops->recalc_accuracy(core->hw,
1804 core->accuracy = parent_accuracy;
1806 hlist_for_each_entry(child, &core->children, child_node)
1807 __clk_recalc_accuracies(child);
1810 static long clk_core_get_accuracy_recalc(struct clk_core *core)
1812 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
1813 __clk_recalc_accuracies(core);
1815 return clk_core_get_accuracy_no_lock(core);
1819 * clk_get_accuracy - return the accuracy of clk
1820 * @clk: the clk whose accuracy is being returned
1822 * Simply returns the cached accuracy of the clk, unless
1823 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1825 * If clk is NULL then returns 0.
1827 long clk_get_accuracy(struct clk *clk)
1835 accuracy = clk_core_get_accuracy_recalc(clk->core);
1836 clk_prepare_unlock();
1840 EXPORT_SYMBOL_GPL(clk_get_accuracy);
1842 static unsigned long clk_recalc(struct clk_core *core,
1843 unsigned long parent_rate)
1845 unsigned long rate = parent_rate;
1847 if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
1848 rate = core->ops->recalc_rate(core->hw, parent_rate);
1849 clk_pm_runtime_put(core);
1855 * __clk_recalc_rates
1856 * @core: first clk in the subtree
1857 * @update_req: Whether req_rate should be updated with the new rate
1858 * @msg: notification type (see include/linux/clk.h)
1860 * Walks the subtree of clks starting with clk and recalculates rates as it
1861 * goes. Note that if a clk does not implement the .recalc_rate callback then
1862 * it is assumed that the clock will take on the rate of its parent.
1864 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1867 static void __clk_recalc_rates(struct clk_core *core, bool update_req,
1870 unsigned long old_rate;
1871 unsigned long parent_rate = 0;
1872 struct clk_core *child;
1874 lockdep_assert_held(&prepare_lock);
1876 old_rate = core->rate;
1879 parent_rate = core->parent->rate;
1881 core->rate = clk_recalc(core, parent_rate);
1883 core->req_rate = core->rate;
1886 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1887 * & ABORT_RATE_CHANGE notifiers
1889 if (core->notifier_count && msg)
1890 __clk_notify(core, msg, old_rate, core->rate);
1892 hlist_for_each_entry(child, &core->children, child_node)
1893 __clk_recalc_rates(child, update_req, msg);
1896 static unsigned long clk_core_get_rate_recalc(struct clk_core *core)
1898 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1899 __clk_recalc_rates(core, false, 0);
1901 return clk_core_get_rate_nolock(core);
1905 * clk_get_rate - return the rate of clk
1906 * @clk: the clk whose rate is being returned
1908 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1909 * is set, which means a recalc_rate will be issued. Can be called regardless of
1910 * the clock enabledness. If clk is NULL, or if an error occurred, then returns
1913 unsigned long clk_get_rate(struct clk *clk)
1921 rate = clk_core_get_rate_recalc(clk->core);
1922 clk_prepare_unlock();
1926 EXPORT_SYMBOL_GPL(clk_get_rate);
1928 static int clk_fetch_parent_index(struct clk_core *core,
1929 struct clk_core *parent)
1936 for (i = 0; i < core->num_parents; i++) {
1937 /* Found it first try! */
1938 if (core->parents[i].core == parent)
1941 /* Something else is here, so keep looking */
1942 if (core->parents[i].core)
1945 /* Maybe core hasn't been cached but the hw is all we know? */
1946 if (core->parents[i].hw) {
1947 if (core->parents[i].hw == parent->hw)
1950 /* Didn't match, but we're expecting a clk_hw */
1954 /* Maybe it hasn't been cached (clk_set_parent() path) */
1955 if (parent == clk_core_get(core, i))
1958 /* Fallback to comparing globally unique names */
1959 if (core->parents[i].name &&
1960 !strcmp(parent->name, core->parents[i].name))
1964 if (i == core->num_parents)
1967 core->parents[i].core = parent;
1972 * clk_hw_get_parent_index - return the index of the parent clock
1973 * @hw: clk_hw associated with the clk being consumed
1975 * Fetches and returns the index of parent clock. Returns -EINVAL if the given
1976 * clock does not have a current parent.
1978 int clk_hw_get_parent_index(struct clk_hw *hw)
1980 struct clk_hw *parent = clk_hw_get_parent(hw);
1982 if (WARN_ON(parent == NULL))
1985 return clk_fetch_parent_index(hw->core, parent->core);
1987 EXPORT_SYMBOL_GPL(clk_hw_get_parent_index);
1990 * Update the orphan status of @core and all its children.
1992 static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
1994 struct clk_core *child;
1996 core->orphan = is_orphan;
1998 hlist_for_each_entry(child, &core->children, child_node)
1999 clk_core_update_orphan_status(child, is_orphan);
2002 static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
2004 bool was_orphan = core->orphan;
2006 hlist_del(&core->child_node);
2009 bool becomes_orphan = new_parent->orphan;
2011 /* avoid duplicate POST_RATE_CHANGE notifications */
2012 if (new_parent->new_child == core)
2013 new_parent->new_child = NULL;
2015 hlist_add_head(&core->child_node, &new_parent->children);
2017 if (was_orphan != becomes_orphan)
2018 clk_core_update_orphan_status(core, becomes_orphan);
2020 hlist_add_head(&core->child_node, &clk_orphan_list);
2022 clk_core_update_orphan_status(core, true);
2025 core->parent = new_parent;
2028 static struct clk_core *__clk_set_parent_before(struct clk_core *core,
2029 struct clk_core *parent)
2031 unsigned long flags;
2032 struct clk_core *old_parent = core->parent;
2035 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
2037 * 2. Migrate prepare state between parents and prevent race with
2040 * If the clock is not prepared, then a race with
2041 * clk_enable/disable() is impossible since we already have the
2042 * prepare lock (future calls to clk_enable() need to be preceded by
2045 * If the clock is prepared, migrate the prepared state to the new
2046 * parent and also protect against a race with clk_enable() by
2047 * forcing the clock and the new parent on. This ensures that all
2048 * future calls to clk_enable() are practically NOPs with respect to
2049 * hardware and software states.
2051 * See also: Comment for clk_set_parent() below.
2054 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
2055 if (core->flags & CLK_OPS_PARENT_ENABLE) {
2056 clk_core_prepare_enable(old_parent);
2057 clk_core_prepare_enable(parent);
2060 /* migrate prepare count if > 0 */
2061 if (core->prepare_count) {
2062 clk_core_prepare_enable(parent);
2063 clk_core_enable_lock(core);
2066 /* update the clk tree topology */
2067 flags = clk_enable_lock();
2068 clk_reparent(core, parent);
2069 clk_enable_unlock(flags);
2074 static void __clk_set_parent_after(struct clk_core *core,
2075 struct clk_core *parent,
2076 struct clk_core *old_parent)
2079 * Finish the migration of prepare state and undo the changes done
2080 * for preventing a race with clk_enable().
2082 if (core->prepare_count) {
2083 clk_core_disable_lock(core);
2084 clk_core_disable_unprepare(old_parent);
2087 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
2088 if (core->flags & CLK_OPS_PARENT_ENABLE) {
2089 clk_core_disable_unprepare(parent);
2090 clk_core_disable_unprepare(old_parent);
2094 static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
2097 unsigned long flags;
2099 struct clk_core *old_parent;
2101 old_parent = __clk_set_parent_before(core, parent);
2103 trace_clk_set_parent(core, parent);
2105 /* change clock input source */
2106 if (parent && core->ops->set_parent)
2107 ret = core->ops->set_parent(core->hw, p_index);
2109 trace_clk_set_parent_complete(core, parent);
2112 flags = clk_enable_lock();
2113 clk_reparent(core, old_parent);
2114 clk_enable_unlock(flags);
2116 __clk_set_parent_after(core, old_parent, parent);
2121 __clk_set_parent_after(core, parent, old_parent);
2127 * __clk_speculate_rates
2128 * @core: first clk in the subtree
2129 * @parent_rate: the "future" rate of clk's parent
2131 * Walks the subtree of clks starting with clk, speculating rates as it
2132 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
2134 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
2135 * pre-rate change notifications and returns early if no clks in the
2136 * subtree have subscribed to the notifications. Note that if a clk does not
2137 * implement the .recalc_rate callback then it is assumed that the clock will
2138 * take on the rate of its parent.
2140 static int __clk_speculate_rates(struct clk_core *core,
2141 unsigned long parent_rate)
2143 struct clk_core *child;
2144 unsigned long new_rate;
2145 int ret = NOTIFY_DONE;
2147 lockdep_assert_held(&prepare_lock);
2149 new_rate = clk_recalc(core, parent_rate);
2151 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
2152 if (core->notifier_count)
2153 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
2155 if (ret & NOTIFY_STOP_MASK) {
2156 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
2157 __func__, core->name, ret);
2161 hlist_for_each_entry(child, &core->children, child_node) {
2162 ret = __clk_speculate_rates(child, new_rate);
2163 if (ret & NOTIFY_STOP_MASK)
2171 static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
2172 struct clk_core *new_parent, u8 p_index)
2174 struct clk_core *child;
2176 core->new_rate = new_rate;
2177 core->new_parent = new_parent;
2178 core->new_parent_index = p_index;
2179 /* include clk in new parent's PRE_RATE_CHANGE notifications */
2180 core->new_child = NULL;
2181 if (new_parent && new_parent != core->parent)
2182 new_parent->new_child = core;
2184 hlist_for_each_entry(child, &core->children, child_node) {
2185 child->new_rate = clk_recalc(child, new_rate);
2186 clk_calc_subtree(child, child->new_rate, NULL, 0);
2191 * calculate the new rates returning the topmost clock that has to be
2194 static struct clk_core *clk_calc_new_rates(struct clk_core *core,
2197 struct clk_core *top = core;
2198 struct clk_core *old_parent, *parent;
2199 unsigned long best_parent_rate = 0;
2200 unsigned long new_rate;
2201 unsigned long min_rate;
2202 unsigned long max_rate;
2207 if (IS_ERR_OR_NULL(core))
2210 /* save parent rate, if it exists */
2211 parent = old_parent = core->parent;
2213 best_parent_rate = parent->rate;
2215 clk_core_get_boundaries(core, &min_rate, &max_rate);
2217 /* find the closest rate and parent clk/rate */
2218 if (clk_core_can_round(core)) {
2219 struct clk_rate_request req;
2221 clk_core_init_rate_req(core, &req, rate);
2223 trace_clk_rate_request_start(&req);
2225 ret = clk_core_determine_round_nolock(core, &req);
2229 trace_clk_rate_request_done(&req);
2231 best_parent_rate = req.best_parent_rate;
2232 new_rate = req.rate;
2233 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
2235 if (new_rate < min_rate || new_rate > max_rate)
2237 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
2238 /* pass-through clock without adjustable parent */
2239 core->new_rate = core->rate;
2242 /* pass-through clock with adjustable parent */
2243 top = clk_calc_new_rates(parent, rate);
2244 new_rate = parent->new_rate;
2248 /* some clocks must be gated to change parent */
2249 if (parent != old_parent &&
2250 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
2251 pr_debug("%s: %s not gated but wants to reparent\n",
2252 __func__, core->name);
2256 /* try finding the new parent index */
2257 if (parent && core->num_parents > 1) {
2258 p_index = clk_fetch_parent_index(core, parent);
2260 pr_debug("%s: clk %s can not be parent of clk %s\n",
2261 __func__, parent->name, core->name);
2266 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
2267 best_parent_rate != parent->rate)
2268 top = clk_calc_new_rates(parent, best_parent_rate);
2271 clk_calc_subtree(core, new_rate, parent, p_index);
2277 * Notify about rate changes in a subtree. Always walk down the whole tree
2278 * so that in case of an error we can walk down the whole tree again and
2281 static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
2282 unsigned long event)
2284 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
2285 int ret = NOTIFY_DONE;
2287 if (core->rate == core->new_rate)
2290 if (core->notifier_count) {
2291 ret = __clk_notify(core, event, core->rate, core->new_rate);
2292 if (ret & NOTIFY_STOP_MASK)
2296 hlist_for_each_entry(child, &core->children, child_node) {
2297 /* Skip children who will be reparented to another clock */
2298 if (child->new_parent && child->new_parent != core)
2300 tmp_clk = clk_propagate_rate_change(child, event);
2305 /* handle the new child who might not be in core->children yet */
2306 if (core->new_child) {
2307 tmp_clk = clk_propagate_rate_change(core->new_child, event);
2316 * walk down a subtree and set the new rates notifying the rate
2319 static void clk_change_rate(struct clk_core *core)
2321 struct clk_core *child;
2322 struct hlist_node *tmp;
2323 unsigned long old_rate;
2324 unsigned long best_parent_rate = 0;
2325 bool skip_set_rate = false;
2326 struct clk_core *old_parent;
2327 struct clk_core *parent = NULL;
2329 old_rate = core->rate;
2331 if (core->new_parent) {
2332 parent = core->new_parent;
2333 best_parent_rate = core->new_parent->rate;
2334 } else if (core->parent) {
2335 parent = core->parent;
2336 best_parent_rate = core->parent->rate;
2339 if (clk_pm_runtime_get(core))
2342 if (core->flags & CLK_SET_RATE_UNGATE) {
2343 clk_core_prepare(core);
2344 clk_core_enable_lock(core);
2347 if (core->new_parent && core->new_parent != core->parent) {
2348 old_parent = __clk_set_parent_before(core, core->new_parent);
2349 trace_clk_set_parent(core, core->new_parent);
2351 if (core->ops->set_rate_and_parent) {
2352 skip_set_rate = true;
2353 core->ops->set_rate_and_parent(core->hw, core->new_rate,
2355 core->new_parent_index);
2356 } else if (core->ops->set_parent) {
2357 core->ops->set_parent(core->hw, core->new_parent_index);
2360 trace_clk_set_parent_complete(core, core->new_parent);
2361 __clk_set_parent_after(core, core->new_parent, old_parent);
2364 if (core->flags & CLK_OPS_PARENT_ENABLE)
2365 clk_core_prepare_enable(parent);
2367 trace_clk_set_rate(core, core->new_rate);
2369 if (!skip_set_rate && core->ops->set_rate)
2370 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
2372 trace_clk_set_rate_complete(core, core->new_rate);
2374 core->rate = clk_recalc(core, best_parent_rate);
2376 if (core->flags & CLK_SET_RATE_UNGATE) {
2377 clk_core_disable_lock(core);
2378 clk_core_unprepare(core);
2381 if (core->flags & CLK_OPS_PARENT_ENABLE)
2382 clk_core_disable_unprepare(parent);
2384 if (core->notifier_count && old_rate != core->rate)
2385 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
2387 if (core->flags & CLK_RECALC_NEW_RATES)
2388 (void)clk_calc_new_rates(core, core->new_rate);
2391 * Use safe iteration, as change_rate can actually swap parents
2392 * for certain clock types.
2394 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
2395 /* Skip children who will be reparented to another clock */
2396 if (child->new_parent && child->new_parent != core)
2398 clk_change_rate(child);
2401 /* handle the new child who might not be in core->children yet */
2402 if (core->new_child)
2403 clk_change_rate(core->new_child);
2405 clk_pm_runtime_put(core);
2408 static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
2409 unsigned long req_rate)
2412 struct clk_rate_request req;
2414 lockdep_assert_held(&prepare_lock);
2419 /* simulate what the rate would be if it could be freely set */
2420 cnt = clk_core_rate_nuke_protect(core);
2424 clk_core_init_rate_req(core, &req, req_rate);
2426 trace_clk_rate_request_start(&req);
2428 ret = clk_core_round_rate_nolock(core, &req);
2430 trace_clk_rate_request_done(&req);
2432 /* restore the protection */
2433 clk_core_rate_restore_protect(core, cnt);
2435 return ret ? 0 : req.rate;
2438 static int clk_core_set_rate_nolock(struct clk_core *core,
2439 unsigned long req_rate)
2441 struct clk_core *top, *fail_clk;
2448 rate = clk_core_req_round_rate_nolock(core, req_rate);
2450 /* bail early if nothing to do */
2451 if (rate == clk_core_get_rate_nolock(core))
2454 /* fail on a direct rate set of a protected provider */
2455 if (clk_core_rate_is_protected(core))
2458 /* calculate new rates and get the topmost changed clock */
2459 top = clk_calc_new_rates(core, req_rate);
2463 ret = clk_pm_runtime_get(core);
2467 /* notify that we are about to change rates */
2468 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
2470 pr_debug("%s: failed to set %s rate\n", __func__,
2472 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
2477 /* change the rates */
2478 clk_change_rate(top);
2480 core->req_rate = req_rate;
2482 clk_pm_runtime_put(core);
2488 * clk_set_rate - specify a new rate for clk
2489 * @clk: the clk whose rate is being changed
2490 * @rate: the new rate for clk
2492 * In the simplest case clk_set_rate will only adjust the rate of clk.
2494 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
2495 * propagate up to clk's parent; whether or not this happens depends on the
2496 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
2497 * after calling .round_rate then upstream parent propagation is ignored. If
2498 * *parent_rate comes back with a new rate for clk's parent then we propagate
2499 * up to clk's parent and set its rate. Upward propagation will continue
2500 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
2501 * .round_rate stops requesting changes to clk's parent_rate.
2503 * Rate changes are accomplished via tree traversal that also recalculates the
2504 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
2506 * Returns 0 on success, -EERROR otherwise.
2508 int clk_set_rate(struct clk *clk, unsigned long rate)
2515 /* prevent racing with updates to the clock topology */
2518 if (clk->exclusive_count)
2519 clk_core_rate_unprotect(clk->core);
2521 ret = clk_core_set_rate_nolock(clk->core, rate);
2523 if (clk->exclusive_count)
2524 clk_core_rate_protect(clk->core);
2526 clk_prepare_unlock();
2530 EXPORT_SYMBOL_GPL(clk_set_rate);
2533 * clk_set_rate_exclusive - specify a new rate and get exclusive control
2534 * @clk: the clk whose rate is being changed
2535 * @rate: the new rate for clk
2537 * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
2538 * within a critical section
2540 * This can be used initially to ensure that at least 1 consumer is
2541 * satisfied when several consumers are competing for exclusivity over the
2542 * same clock provider.
2544 * The exclusivity is not applied if setting the rate failed.
2546 * Calls to clk_rate_exclusive_get() should be balanced with calls to
2547 * clk_rate_exclusive_put().
2549 * Returns 0 on success, -EERROR otherwise.
2551 int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
2558 /* prevent racing with updates to the clock topology */
2562 * The temporary protection removal is not here, on purpose
2563 * This function is meant to be used instead of clk_rate_protect,
2564 * so before the consumer code path protect the clock provider
2567 ret = clk_core_set_rate_nolock(clk->core, rate);
2569 clk_core_rate_protect(clk->core);
2570 clk->exclusive_count++;
2573 clk_prepare_unlock();
2577 EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
2579 static int clk_set_rate_range_nolock(struct clk *clk,
2584 unsigned long old_min, old_max, rate;
2586 lockdep_assert_held(&prepare_lock);
2591 trace_clk_set_rate_range(clk->core, min, max);
2594 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
2595 __func__, clk->core->name, clk->dev_id, clk->con_id,
2600 if (clk->exclusive_count)
2601 clk_core_rate_unprotect(clk->core);
2603 /* Save the current values in case we need to rollback the change */
2604 old_min = clk->min_rate;
2605 old_max = clk->max_rate;
2606 clk->min_rate = min;
2607 clk->max_rate = max;
2609 if (!clk_core_check_boundaries(clk->core, min, max)) {
2614 rate = clk->core->req_rate;
2615 if (clk->core->flags & CLK_GET_RATE_NOCACHE)
2616 rate = clk_core_get_rate_recalc(clk->core);
2619 * Since the boundaries have been changed, let's give the
2620 * opportunity to the provider to adjust the clock rate based on
2621 * the new boundaries.
2623 * We also need to handle the case where the clock is currently
2624 * outside of the boundaries. Clamping the last requested rate
2625 * to the current minimum and maximum will also handle this.
2628 * There is a catch. It may fail for the usual reason (clock
2629 * broken, clock protected, etc) but also because:
2630 * - round_rate() was not favorable and fell on the wrong
2631 * side of the boundary
2632 * - the determine_rate() callback does not really check for
2633 * this corner case when determining the rate
2635 rate = clamp(rate, min, max);
2636 ret = clk_core_set_rate_nolock(clk->core, rate);
2638 /* rollback the changes */
2639 clk->min_rate = old_min;
2640 clk->max_rate = old_max;
2644 if (clk->exclusive_count)
2645 clk_core_rate_protect(clk->core);
2651 * clk_set_rate_range - set a rate range for a clock source
2652 * @clk: clock source
2653 * @min: desired minimum clock rate in Hz, inclusive
2654 * @max: desired maximum clock rate in Hz, inclusive
2656 * Return: 0 for success or negative errno on failure.
2658 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
2667 ret = clk_set_rate_range_nolock(clk, min, max);
2669 clk_prepare_unlock();
2673 EXPORT_SYMBOL_GPL(clk_set_rate_range);
2676 * clk_set_min_rate - set a minimum clock rate for a clock source
2677 * @clk: clock source
2678 * @rate: desired minimum clock rate in Hz, inclusive
2680 * Returns success (0) or negative errno.
2682 int clk_set_min_rate(struct clk *clk, unsigned long rate)
2687 trace_clk_set_min_rate(clk->core, rate);
2689 return clk_set_rate_range(clk, rate, clk->max_rate);
2691 EXPORT_SYMBOL_GPL(clk_set_min_rate);
2694 * clk_set_max_rate - set a maximum clock rate for a clock source
2695 * @clk: clock source
2696 * @rate: desired maximum clock rate in Hz, inclusive
2698 * Returns success (0) or negative errno.
2700 int clk_set_max_rate(struct clk *clk, unsigned long rate)
2705 trace_clk_set_max_rate(clk->core, rate);
2707 return clk_set_rate_range(clk, clk->min_rate, rate);
2709 EXPORT_SYMBOL_GPL(clk_set_max_rate);
2712 * clk_get_parent - return the parent of a clk
2713 * @clk: the clk whose parent gets returned
2715 * Simply returns clk->parent. Returns NULL if clk is NULL.
2717 struct clk *clk_get_parent(struct clk *clk)
2725 /* TODO: Create a per-user clk and change callers to call clk_put */
2726 parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
2727 clk_prepare_unlock();
2731 EXPORT_SYMBOL_GPL(clk_get_parent);
2733 static struct clk_core *__clk_init_parent(struct clk_core *core)
2737 if (core->num_parents > 1 && core->ops->get_parent)
2738 index = core->ops->get_parent(core->hw);
2740 return clk_core_get_parent_by_index(core, index);
2743 static void clk_core_reparent(struct clk_core *core,
2744 struct clk_core *new_parent)
2746 clk_reparent(core, new_parent);
2747 __clk_recalc_accuracies(core);
2748 __clk_recalc_rates(core, true, POST_RATE_CHANGE);
2751 void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
2756 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
2760 * clk_has_parent - check if a clock is a possible parent for another
2761 * @clk: clock source
2762 * @parent: parent clock source
2764 * This function can be used in drivers that need to check that a clock can be
2765 * the parent of another without actually changing the parent.
2767 * Returns true if @parent is a possible parent for @clk, false otherwise.
2769 bool clk_has_parent(const struct clk *clk, const struct clk *parent)
2771 /* NULL clocks should be nops, so return success if either is NULL. */
2772 if (!clk || !parent)
2775 return clk_core_has_parent(clk->core, parent->core);
2777 EXPORT_SYMBOL_GPL(clk_has_parent);
2779 static int clk_core_set_parent_nolock(struct clk_core *core,
2780 struct clk_core *parent)
2784 unsigned long p_rate = 0;
2786 lockdep_assert_held(&prepare_lock);
2791 if (core->parent == parent)
2794 /* verify ops for multi-parent clks */
2795 if (core->num_parents > 1 && !core->ops->set_parent)
2798 /* check that we are allowed to re-parent if the clock is in use */
2799 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
2802 if (clk_core_rate_is_protected(core))
2805 /* try finding the new parent index */
2807 p_index = clk_fetch_parent_index(core, parent);
2809 pr_debug("%s: clk %s can not be parent of clk %s\n",
2810 __func__, parent->name, core->name);
2813 p_rate = parent->rate;
2816 ret = clk_pm_runtime_get(core);
2820 /* propagate PRE_RATE_CHANGE notifications */
2821 ret = __clk_speculate_rates(core, p_rate);
2823 /* abort if a driver objects */
2824 if (ret & NOTIFY_STOP_MASK)
2827 /* do the re-parent */
2828 ret = __clk_set_parent(core, parent, p_index);
2830 /* propagate rate an accuracy recalculation accordingly */
2832 __clk_recalc_rates(core, true, ABORT_RATE_CHANGE);
2834 __clk_recalc_rates(core, true, POST_RATE_CHANGE);
2835 __clk_recalc_accuracies(core);
2839 clk_pm_runtime_put(core);
2844 int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *parent)
2846 return clk_core_set_parent_nolock(hw->core, parent->core);
2848 EXPORT_SYMBOL_GPL(clk_hw_set_parent);
2851 * clk_set_parent - switch the parent of a mux clk
2852 * @clk: the mux clk whose input we are switching
2853 * @parent: the new input to clk
2855 * Re-parent clk to use parent as its new input source. If clk is in
2856 * prepared state, the clk will get enabled for the duration of this call. If
2857 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2858 * that, the reparenting is glitchy in hardware, etc), use the
2859 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2861 * After successfully changing clk's parent clk_set_parent will update the
2862 * clk topology, sysfs topology and propagate rate recalculation via
2863 * __clk_recalc_rates.
2865 * Returns 0 on success, -EERROR otherwise.
2867 int clk_set_parent(struct clk *clk, struct clk *parent)
2876 if (clk->exclusive_count)
2877 clk_core_rate_unprotect(clk->core);
2879 ret = clk_core_set_parent_nolock(clk->core,
2880 parent ? parent->core : NULL);
2882 if (clk->exclusive_count)
2883 clk_core_rate_protect(clk->core);
2885 clk_prepare_unlock();
2889 EXPORT_SYMBOL_GPL(clk_set_parent);
2891 static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
2895 lockdep_assert_held(&prepare_lock);
2900 if (clk_core_rate_is_protected(core))
2903 trace_clk_set_phase(core, degrees);
2905 if (core->ops->set_phase) {
2906 ret = core->ops->set_phase(core->hw, degrees);
2908 core->phase = degrees;
2911 trace_clk_set_phase_complete(core, degrees);
2917 * clk_set_phase - adjust the phase shift of a clock signal
2918 * @clk: clock signal source
2919 * @degrees: number of degrees the signal is shifted
2921 * Shifts the phase of a clock signal by the specified
2922 * degrees. Returns 0 on success, -EERROR otherwise.
2924 * This function makes no distinction about the input or reference
2925 * signal that we adjust the clock signal phase against. For example
2926 * phase locked-loop clock signal generators we may shift phase with
2927 * respect to feedback clock signal input, but for other cases the
2928 * clock phase may be shifted with respect to some other, unspecified
2931 * Additionally the concept of phase shift does not propagate through
2932 * the clock tree hierarchy, which sets it apart from clock rates and
2933 * clock accuracy. A parent clock phase attribute does not have an
2934 * impact on the phase attribute of a child clock.
2936 int clk_set_phase(struct clk *clk, int degrees)
2943 /* sanity check degrees */
2950 if (clk->exclusive_count)
2951 clk_core_rate_unprotect(clk->core);
2953 ret = clk_core_set_phase_nolock(clk->core, degrees);
2955 if (clk->exclusive_count)
2956 clk_core_rate_protect(clk->core);
2958 clk_prepare_unlock();
2962 EXPORT_SYMBOL_GPL(clk_set_phase);
2964 static int clk_core_get_phase(struct clk_core *core)
2968 lockdep_assert_held(&prepare_lock);
2969 if (!core->ops->get_phase)
2972 /* Always try to update cached phase if possible */
2973 ret = core->ops->get_phase(core->hw);
2981 * clk_get_phase - return the phase shift of a clock signal
2982 * @clk: clock signal source
2984 * Returns the phase shift of a clock node in degrees, otherwise returns
2987 int clk_get_phase(struct clk *clk)
2995 ret = clk_core_get_phase(clk->core);
2996 clk_prepare_unlock();
3000 EXPORT_SYMBOL_GPL(clk_get_phase);
3002 static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
3004 /* Assume a default value of 50% */
3009 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);
3011 static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
3013 struct clk_duty *duty = &core->duty;
3016 if (!core->ops->get_duty_cycle)
3017 return clk_core_update_duty_cycle_parent_nolock(core);
3019 ret = core->ops->get_duty_cycle(core->hw, duty);
3023 /* Don't trust the clock provider too much */
3024 if (duty->den == 0 || duty->num > duty->den) {
3032 clk_core_reset_duty_cycle_nolock(core);
3036 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
3041 core->flags & CLK_DUTY_CYCLE_PARENT) {
3042 ret = clk_core_update_duty_cycle_nolock(core->parent);
3043 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
3045 clk_core_reset_duty_cycle_nolock(core);
3051 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
3052 struct clk_duty *duty);
3054 static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
3055 struct clk_duty *duty)
3059 lockdep_assert_held(&prepare_lock);
3061 if (clk_core_rate_is_protected(core))
3064 trace_clk_set_duty_cycle(core, duty);
3066 if (!core->ops->set_duty_cycle)
3067 return clk_core_set_duty_cycle_parent_nolock(core, duty);
3069 ret = core->ops->set_duty_cycle(core->hw, duty);
3071 memcpy(&core->duty, duty, sizeof(*duty));
3073 trace_clk_set_duty_cycle_complete(core, duty);
3078 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
3079 struct clk_duty *duty)
3084 core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
3085 ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
3086 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
3093 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
3094 * @clk: clock signal source
3095 * @num: numerator of the duty cycle ratio to be applied
3096 * @den: denominator of the duty cycle ratio to be applied
3098 * Apply the duty cycle ratio if the ratio is valid and the clock can
3099 * perform this operation
3101 * Returns (0) on success, a negative errno otherwise.
3103 int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
3106 struct clk_duty duty;
3111 /* sanity check the ratio */
3112 if (den == 0 || num > den)
3120 if (clk->exclusive_count)
3121 clk_core_rate_unprotect(clk->core);
3123 ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
3125 if (clk->exclusive_count)
3126 clk_core_rate_protect(clk->core);
3128 clk_prepare_unlock();
3132 EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
3134 static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
3137 struct clk_duty *duty = &core->duty;
3142 ret = clk_core_update_duty_cycle_nolock(core);
3144 ret = mult_frac(scale, duty->num, duty->den);
3146 clk_prepare_unlock();
3152 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
3153 * @clk: clock signal source
3154 * @scale: scaling factor to be applied to represent the ratio as an integer
3156 * Returns the duty cycle ratio of a clock node multiplied by the provided
3157 * scaling factor, or negative errno on error.
3159 int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
3164 return clk_core_get_scaled_duty_cycle(clk->core, scale);
3166 EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
3169 * clk_is_match - check if two clk's point to the same hardware clock
3170 * @p: clk compared against q
3171 * @q: clk compared against p
3173 * Returns true if the two struct clk pointers both point to the same hardware
3174 * clock node. Put differently, returns true if struct clk *p and struct clk *q
3175 * share the same struct clk_core object.
3177 * Returns false otherwise. Note that two NULL clks are treated as matching.
3179 bool clk_is_match(const struct clk *p, const struct clk *q)
3181 /* trivial case: identical struct clk's or both NULL */
3185 /* true if clk->core pointers match. Avoid dereferencing garbage */
3186 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
3187 if (p->core == q->core)
3192 EXPORT_SYMBOL_GPL(clk_is_match);
3194 /*** debugfs support ***/
3196 #ifdef CONFIG_DEBUG_FS
3197 #include <linux/debugfs.h>
3199 static struct dentry *rootdir;
3200 static int inited = 0;
3201 static DEFINE_MUTEX(clk_debug_lock);
3202 static HLIST_HEAD(clk_debug_list);
3204 static struct hlist_head *orphan_list[] = {
3209 static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
3213 struct clk *clk_user;
3216 seq_printf(s, "%*s%-*s %-7d %-8d %-8d %-11lu %-10lu ",
3218 35 - level * 3, c->name,
3219 c->enable_count, c->prepare_count, c->protect_count,
3220 clk_core_get_rate_recalc(c),
3221 clk_core_get_accuracy_recalc(c));
3223 phase = clk_core_get_phase(c);
3225 seq_printf(s, "%-5d", phase);
3227 seq_puts(s, "-----");
3229 seq_printf(s, " %-6d", clk_core_get_scaled_duty_cycle(c, 100000));
3231 if (c->ops->is_enabled)
3232 seq_printf(s, " %5c ", clk_core_is_enabled(c) ? 'Y' : 'N');
3233 else if (!c->ops->enable)
3234 seq_printf(s, " %5c ", 'Y');
3236 seq_printf(s, " %5c ", '?');
3238 hlist_for_each_entry(clk_user, &c->clks, clks_node) {
3239 seq_printf(s, "%*s%-*s %-25s\n",
3240 level * 3 + 2 + 105 * multi_node, "",
3242 clk_user->dev_id ? clk_user->dev_id : "deviceless",
3243 clk_user->con_id ? clk_user->con_id : "no_connection_id");
3250 static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
3253 struct clk_core *child;
3255 clk_pm_runtime_get(c);
3256 clk_summary_show_one(s, c, level);
3257 clk_pm_runtime_put(c);
3259 hlist_for_each_entry(child, &c->children, child_node)
3260 clk_summary_show_subtree(s, child, level + 1);
3263 static int clk_summary_show(struct seq_file *s, void *data)
3266 struct hlist_head **lists = s->private;
3268 seq_puts(s, " enable prepare protect duty hardware connection\n");
3269 seq_puts(s, " clock count count count rate accuracy phase cycle enable consumer id\n");
3270 seq_puts(s, "---------------------------------------------------------------------------------------------------------------------------------------------\n");
3275 for (; *lists; lists++)
3276 hlist_for_each_entry(c, *lists, child_node)
3277 clk_summary_show_subtree(s, c, 0);
3279 clk_prepare_unlock();
3283 DEFINE_SHOW_ATTRIBUTE(clk_summary);
3285 static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
3288 unsigned long min_rate, max_rate;
3290 clk_core_get_boundaries(c, &min_rate, &max_rate);
3292 /* This should be JSON format, i.e. elements separated with a comma */
3293 seq_printf(s, "\"%s\": { ", c->name);
3294 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
3295 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
3296 seq_printf(s, "\"protect_count\": %d,", c->protect_count);
3297 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate_recalc(c));
3298 seq_printf(s, "\"min_rate\": %lu,", min_rate);
3299 seq_printf(s, "\"max_rate\": %lu,", max_rate);
3300 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy_recalc(c));
3301 phase = clk_core_get_phase(c);
3303 seq_printf(s, "\"phase\": %d,", phase);
3304 seq_printf(s, "\"duty_cycle\": %u",
3305 clk_core_get_scaled_duty_cycle(c, 100000));
3308 static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
3310 struct clk_core *child;
3312 clk_dump_one(s, c, level);
3314 hlist_for_each_entry(child, &c->children, child_node) {
3316 clk_dump_subtree(s, child, level + 1);
3322 static int clk_dump_show(struct seq_file *s, void *data)
3325 bool first_node = true;
3326 struct hlist_head **lists = s->private;
3331 for (; *lists; lists++) {
3332 hlist_for_each_entry(c, *lists, child_node) {
3336 clk_dump_subtree(s, c, 0);
3340 clk_prepare_unlock();
3345 DEFINE_SHOW_ATTRIBUTE(clk_dump);
3347 #undef CLOCK_ALLOW_WRITE_DEBUGFS
3348 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3350 * This can be dangerous, therefore don't provide any real compile time
3351 * configuration option for this feature.
3352 * People who want to use this will need to modify the source code directly.
3354 static int clk_rate_set(void *data, u64 val)
3356 struct clk_core *core = data;
3360 ret = clk_core_set_rate_nolock(core, val);
3361 clk_prepare_unlock();
3366 #define clk_rate_mode 0644
3368 static int clk_phase_set(void *data, u64 val)
3370 struct clk_core *core = data;
3371 int degrees = do_div(val, 360);
3375 ret = clk_core_set_phase_nolock(core, degrees);
3376 clk_prepare_unlock();
3381 #define clk_phase_mode 0644
3383 static int clk_prepare_enable_set(void *data, u64 val)
3385 struct clk_core *core = data;
3389 ret = clk_prepare_enable(core->hw->clk);
3391 clk_disable_unprepare(core->hw->clk);
3396 static int clk_prepare_enable_get(void *data, u64 *val)
3398 struct clk_core *core = data;
3400 *val = core->enable_count && core->prepare_count;
3404 DEFINE_DEBUGFS_ATTRIBUTE(clk_prepare_enable_fops, clk_prepare_enable_get,
3405 clk_prepare_enable_set, "%llu\n");
3408 #define clk_rate_set NULL
3409 #define clk_rate_mode 0444
3411 #define clk_phase_set NULL
3412 #define clk_phase_mode 0644
3415 static int clk_rate_get(void *data, u64 *val)
3417 struct clk_core *core = data;
3420 *val = clk_core_get_rate_recalc(core);
3421 clk_prepare_unlock();
3426 DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops, clk_rate_get, clk_rate_set, "%llu\n");
3428 static int clk_phase_get(void *data, u64 *val)
3430 struct clk_core *core = data;
3436 DEFINE_DEBUGFS_ATTRIBUTE(clk_phase_fops, clk_phase_get, clk_phase_set, "%llu\n");
3438 static const struct {
3442 #define ENTRY(f) { f, #f }
3443 ENTRY(CLK_SET_RATE_GATE),
3444 ENTRY(CLK_SET_PARENT_GATE),
3445 ENTRY(CLK_SET_RATE_PARENT),
3446 ENTRY(CLK_IGNORE_UNUSED),
3447 ENTRY(CLK_GET_RATE_NOCACHE),
3448 ENTRY(CLK_SET_RATE_NO_REPARENT),
3449 ENTRY(CLK_GET_ACCURACY_NOCACHE),
3450 ENTRY(CLK_RECALC_NEW_RATES),
3451 ENTRY(CLK_SET_RATE_UNGATE),
3452 ENTRY(CLK_IS_CRITICAL),
3453 ENTRY(CLK_OPS_PARENT_ENABLE),
3454 ENTRY(CLK_DUTY_CYCLE_PARENT),
3458 static int clk_flags_show(struct seq_file *s, void *data)
3460 struct clk_core *core = s->private;
3461 unsigned long flags = core->flags;
3464 for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
3465 if (flags & clk_flags[i].flag) {
3466 seq_printf(s, "%s\n", clk_flags[i].name);
3467 flags &= ~clk_flags[i].flag;
3472 seq_printf(s, "0x%lx\n", flags);
3477 DEFINE_SHOW_ATTRIBUTE(clk_flags);
3479 static void possible_parent_show(struct seq_file *s, struct clk_core *core,
3480 unsigned int i, char terminator)
3482 struct clk_core *parent;
3483 const char *name = NULL;
3486 * Go through the following options to fetch a parent's name.
3488 * 1. Fetch the registered parent clock and use its name
3489 * 2. Use the global (fallback) name if specified
3490 * 3. Use the local fw_name if provided
3491 * 4. Fetch parent clock's clock-output-name if DT index was set
3493 * This may still fail in some cases, such as when the parent is
3494 * specified directly via a struct clk_hw pointer, but it isn't
3497 parent = clk_core_get_parent_by_index(core, i);
3499 seq_puts(s, parent->name);
3500 } else if (core->parents[i].name) {
3501 seq_puts(s, core->parents[i].name);
3502 } else if (core->parents[i].fw_name) {
3503 seq_printf(s, "<%s>(fw)", core->parents[i].fw_name);
3505 if (core->parents[i].index >= 0)
3506 name = of_clk_get_parent_name(core->of_node, core->parents[i].index);
3513 seq_putc(s, terminator);
3516 static int possible_parents_show(struct seq_file *s, void *data)
3518 struct clk_core *core = s->private;
3521 for (i = 0; i < core->num_parents - 1; i++)
3522 possible_parent_show(s, core, i, ' ');
3524 possible_parent_show(s, core, i, '\n');
3528 DEFINE_SHOW_ATTRIBUTE(possible_parents);
3530 static int current_parent_show(struct seq_file *s, void *data)
3532 struct clk_core *core = s->private;
3535 seq_printf(s, "%s\n", core->parent->name);
3539 DEFINE_SHOW_ATTRIBUTE(current_parent);
3541 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3542 static ssize_t current_parent_write(struct file *file, const char __user *ubuf,
3543 size_t count, loff_t *ppos)
3545 struct seq_file *s = file->private_data;
3546 struct clk_core *core = s->private;
3547 struct clk_core *parent;
3551 err = kstrtou8_from_user(ubuf, count, 0, &idx);
3555 parent = clk_core_get_parent_by_index(core, idx);
3560 err = clk_core_set_parent_nolock(core, parent);
3561 clk_prepare_unlock();
3568 static const struct file_operations current_parent_rw_fops = {
3569 .open = current_parent_open,
3570 .write = current_parent_write,
3572 .llseek = seq_lseek,
3573 .release = single_release,
3577 static int clk_duty_cycle_show(struct seq_file *s, void *data)
3579 struct clk_core *core = s->private;
3580 struct clk_duty *duty = &core->duty;
3582 seq_printf(s, "%u/%u\n", duty->num, duty->den);
3586 DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
3588 static int clk_min_rate_show(struct seq_file *s, void *data)
3590 struct clk_core *core = s->private;
3591 unsigned long min_rate, max_rate;
3594 clk_core_get_boundaries(core, &min_rate, &max_rate);
3595 clk_prepare_unlock();
3596 seq_printf(s, "%lu\n", min_rate);
3600 DEFINE_SHOW_ATTRIBUTE(clk_min_rate);
3602 static int clk_max_rate_show(struct seq_file *s, void *data)
3604 struct clk_core *core = s->private;
3605 unsigned long min_rate, max_rate;
3608 clk_core_get_boundaries(core, &min_rate, &max_rate);
3609 clk_prepare_unlock();
3610 seq_printf(s, "%lu\n", max_rate);
3614 DEFINE_SHOW_ATTRIBUTE(clk_max_rate);
3616 static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
3618 struct dentry *root;
3620 if (!core || !pdentry)
3623 root = debugfs_create_dir(core->name, pdentry);
3624 core->dentry = root;
3626 debugfs_create_file("clk_rate", clk_rate_mode, root, core,
3628 debugfs_create_file("clk_min_rate", 0444, root, core, &clk_min_rate_fops);
3629 debugfs_create_file("clk_max_rate", 0444, root, core, &clk_max_rate_fops);
3630 debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
3631 debugfs_create_file("clk_phase", clk_phase_mode, root, core,
3633 debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
3634 debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
3635 debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
3636 debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
3637 debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
3638 debugfs_create_file("clk_duty_cycle", 0444, root, core,
3639 &clk_duty_cycle_fops);
3640 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3641 debugfs_create_file("clk_prepare_enable", 0644, root, core,
3642 &clk_prepare_enable_fops);
3644 if (core->num_parents > 1)
3645 debugfs_create_file("clk_parent", 0644, root, core,
3646 ¤t_parent_rw_fops);
3649 if (core->num_parents > 0)
3650 debugfs_create_file("clk_parent", 0444, root, core,
3651 ¤t_parent_fops);
3653 if (core->num_parents > 1)
3654 debugfs_create_file("clk_possible_parents", 0444, root, core,
3655 &possible_parents_fops);
3657 if (core->ops->debug_init)
3658 core->ops->debug_init(core->hw, core->dentry);
3662 * clk_debug_register - add a clk node to the debugfs clk directory
3663 * @core: the clk being added to the debugfs clk directory
3665 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
3666 * initialized. Otherwise it bails out early since the debugfs clk directory
3667 * will be created lazily by clk_debug_init as part of a late_initcall.
3669 static void clk_debug_register(struct clk_core *core)
3671 mutex_lock(&clk_debug_lock);
3672 hlist_add_head(&core->debug_node, &clk_debug_list);
3674 clk_debug_create_one(core, rootdir);
3675 mutex_unlock(&clk_debug_lock);
3679 * clk_debug_unregister - remove a clk node from the debugfs clk directory
3680 * @core: the clk being removed from the debugfs clk directory
3682 * Dynamically removes a clk and all its child nodes from the
3683 * debugfs clk directory if clk->dentry points to debugfs created by
3684 * clk_debug_register in __clk_core_init.
3686 static void clk_debug_unregister(struct clk_core *core)
3688 mutex_lock(&clk_debug_lock);
3689 hlist_del_init(&core->debug_node);
3690 debugfs_remove_recursive(core->dentry);
3691 core->dentry = NULL;
3692 mutex_unlock(&clk_debug_lock);
3696 * clk_debug_init - lazily populate the debugfs clk directory
3698 * clks are often initialized very early during boot before memory can be
3699 * dynamically allocated and well before debugfs is setup. This function
3700 * populates the debugfs clk directory once at boot-time when we know that
3701 * debugfs is setup. It should only be called once at boot-time, all other clks
3702 * added dynamically will be done so with clk_debug_register.
3704 static int __init clk_debug_init(void)
3706 struct clk_core *core;
3708 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3710 pr_warn("********************************************************************\n");
3711 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
3713 pr_warn("** WRITEABLE clk DebugFS SUPPORT HAS BEEN ENABLED IN THIS KERNEL **\n");
3715 pr_warn("** This means that this kernel is built to expose clk operations **\n");
3716 pr_warn("** such as parent or rate setting, enabling, disabling, etc. **\n");
3717 pr_warn("** to userspace, which may compromise security on your system. **\n");
3719 pr_warn("** If you see this message and you are not debugging the **\n");
3720 pr_warn("** kernel, report this immediately to your vendor! **\n");
3722 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
3723 pr_warn("********************************************************************\n");
3726 rootdir = debugfs_create_dir("clk", NULL);
3728 debugfs_create_file("clk_summary", 0444, rootdir, &all_lists,
3730 debugfs_create_file("clk_dump", 0444, rootdir, &all_lists,
3732 debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list,
3734 debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list,
3737 mutex_lock(&clk_debug_lock);
3738 hlist_for_each_entry(core, &clk_debug_list, debug_node)
3739 clk_debug_create_one(core, rootdir);
3742 mutex_unlock(&clk_debug_lock);
3746 late_initcall(clk_debug_init);
3748 static inline void clk_debug_register(struct clk_core *core) { }
3749 static inline void clk_debug_unregister(struct clk_core *core)
3754 static void clk_core_reparent_orphans_nolock(void)
3756 struct clk_core *orphan;
3757 struct hlist_node *tmp2;
3760 * walk the list of orphan clocks and reparent any that newly finds a
3763 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
3764 struct clk_core *parent = __clk_init_parent(orphan);
3767 * We need to use __clk_set_parent_before() and _after() to
3768 * properly migrate any prepare/enable count of the orphan
3769 * clock. This is important for CLK_IS_CRITICAL clocks, which
3770 * are enabled during init but might not have a parent yet.
3773 /* update the clk tree topology */
3774 __clk_set_parent_before(orphan, parent);
3775 __clk_set_parent_after(orphan, parent, NULL);
3776 __clk_recalc_accuracies(orphan);
3777 __clk_recalc_rates(orphan, true, 0);
3780 * __clk_init_parent() will set the initial req_rate to
3781 * 0 if the clock doesn't have clk_ops::recalc_rate and
3782 * is an orphan when it's registered.
3784 * 'req_rate' is used by clk_set_rate_range() and
3785 * clk_put() to trigger a clk_set_rate() call whenever
3786 * the boundaries are modified. Let's make sure
3787 * 'req_rate' is set to something non-zero so that
3788 * clk_set_rate_range() doesn't drop the frequency.
3790 orphan->req_rate = orphan->rate;
3796 * __clk_core_init - initialize the data structures in a struct clk_core
3797 * @core: clk_core being initialized
3799 * Initializes the lists in struct clk_core, queries the hardware for the
3800 * parent and rate and sets them both.
3802 static int __clk_core_init(struct clk_core *core)
3805 struct clk_core *parent;
3812 * Set hw->core after grabbing the prepare_lock to synchronize with
3813 * callers of clk_core_fill_parent_index() where we treat hw->core
3814 * being NULL as the clk not being registered yet. This is crucial so
3815 * that clks aren't parented until their parent is fully registered.
3817 core->hw->core = core;
3819 ret = clk_pm_runtime_get(core);
3823 /* check to see if a clock with this name is already registered */
3824 if (clk_core_lookup(core->name)) {
3825 pr_debug("%s: clk %s already initialized\n",
3826 __func__, core->name);
3831 /* check that clk_ops are sane. See Documentation/driver-api/clk.rst */
3832 if (core->ops->set_rate &&
3833 !((core->ops->round_rate || core->ops->determine_rate) &&
3834 core->ops->recalc_rate)) {
3835 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
3836 __func__, core->name);
3841 if (core->ops->set_parent && !core->ops->get_parent) {
3842 pr_err("%s: %s must implement .get_parent & .set_parent\n",
3843 __func__, core->name);
3848 if (core->ops->set_parent && !core->ops->determine_rate) {
3849 pr_err("%s: %s must implement .set_parent & .determine_rate\n",
3850 __func__, core->name);
3855 if (core->num_parents > 1 && !core->ops->get_parent) {
3856 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
3857 __func__, core->name);
3862 if (core->ops->set_rate_and_parent &&
3863 !(core->ops->set_parent && core->ops->set_rate)) {
3864 pr_err("%s: %s must implement .set_parent & .set_rate\n",
3865 __func__, core->name);
3871 * optional platform-specific magic
3873 * The .init callback is not used by any of the basic clock types, but
3874 * exists for weird hardware that must perform initialization magic for
3875 * CCF to get an accurate view of clock for any other callbacks. It may
3876 * also be used needs to perform dynamic allocations. Such allocation
3877 * must be freed in the terminate() callback.
3878 * This callback shall not be used to initialize the parameters state,
3879 * such as rate, parent, etc ...
3881 * If it exist, this callback should called before any other callback of
3884 if (core->ops->init) {
3885 ret = core->ops->init(core->hw);
3890 parent = core->parent = __clk_init_parent(core);
3893 * Populate core->parent if parent has already been clk_core_init'd. If
3894 * parent has not yet been clk_core_init'd then place clk in the orphan
3895 * list. If clk doesn't have any parents then place it in the root
3898 * Every time a new clk is clk_init'd then we walk the list of orphan
3899 * clocks and re-parent any that are children of the clock currently
3903 hlist_add_head(&core->child_node, &parent->children);
3904 core->orphan = parent->orphan;
3905 } else if (!core->num_parents) {
3906 hlist_add_head(&core->child_node, &clk_root_list);
3907 core->orphan = false;
3909 hlist_add_head(&core->child_node, &clk_orphan_list);
3910 core->orphan = true;
3914 * Set clk's accuracy. The preferred method is to use
3915 * .recalc_accuracy. For simple clocks and lazy developers the default
3916 * fallback is to use the parent's accuracy. If a clock doesn't have a
3917 * parent (or is orphaned) then accuracy is set to zero (perfect
3920 if (core->ops->recalc_accuracy)
3921 core->accuracy = core->ops->recalc_accuracy(core->hw,
3922 clk_core_get_accuracy_no_lock(parent));
3924 core->accuracy = parent->accuracy;
3929 * Set clk's phase by clk_core_get_phase() caching the phase.
3930 * Since a phase is by definition relative to its parent, just
3931 * query the current clock phase, or just assume it's in phase.
3933 phase = clk_core_get_phase(core);
3936 pr_warn("%s: Failed to get phase for clk '%s'\n", __func__,
3942 * Set clk's duty cycle.
3944 clk_core_update_duty_cycle_nolock(core);
3947 * Set clk's rate. The preferred method is to use .recalc_rate. For
3948 * simple clocks and lazy developers the default fallback is to use the
3949 * parent's rate. If a clock doesn't have a parent (or is orphaned)
3950 * then rate is set to zero.
3952 if (core->ops->recalc_rate)
3953 rate = core->ops->recalc_rate(core->hw,
3954 clk_core_get_rate_nolock(parent));
3956 rate = parent->rate;
3959 core->rate = core->req_rate = rate;
3962 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
3963 * don't get accidentally disabled when walking the orphan tree and
3964 * reparenting clocks
3966 if (core->flags & CLK_IS_CRITICAL) {
3967 ret = clk_core_prepare(core);
3969 pr_warn("%s: critical clk '%s' failed to prepare\n",
3970 __func__, core->name);
3974 ret = clk_core_enable_lock(core);
3976 pr_warn("%s: critical clk '%s' failed to enable\n",
3977 __func__, core->name);
3978 clk_core_unprepare(core);
3983 clk_core_reparent_orphans_nolock();
3985 kref_init(&core->ref);
3987 clk_pm_runtime_put(core);
3990 hlist_del_init(&core->child_node);
3991 core->hw->core = NULL;
3994 clk_prepare_unlock();
3997 clk_debug_register(core);
4003 * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core
4004 * @core: clk to add consumer to
4005 * @clk: consumer to link to a clk
4007 static void clk_core_link_consumer(struct clk_core *core, struct clk *clk)
4010 hlist_add_head(&clk->clks_node, &core->clks);
4011 clk_prepare_unlock();
4015 * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core
4016 * @clk: consumer to unlink
4018 static void clk_core_unlink_consumer(struct clk *clk)
4020 lockdep_assert_held(&prepare_lock);
4021 hlist_del(&clk->clks_node);
4025 * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core
4026 * @core: clk to allocate a consumer for
4027 * @dev_id: string describing device name
4028 * @con_id: connection ID string on device
4030 * Returns: clk consumer left unlinked from the consumer list
4032 static struct clk *alloc_clk(struct clk_core *core, const char *dev_id,
4037 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
4039 return ERR_PTR(-ENOMEM);
4042 clk->dev_id = dev_id;
4043 clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
4044 clk->max_rate = ULONG_MAX;
4050 * free_clk - Free a clk consumer
4051 * @clk: clk consumer to free
4053 * Note, this assumes the clk has been unlinked from the clk_core consumer
4056 static void free_clk(struct clk *clk)
4058 kfree_const(clk->con_id);
4063 * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given
4065 * @dev: clk consumer device
4066 * @hw: clk_hw associated with the clk being consumed
4067 * @dev_id: string describing device name
4068 * @con_id: connection ID string on device
4070 * This is the main function used to create a clk pointer for use by clk
4071 * consumers. It connects a consumer to the clk_core and clk_hw structures
4072 * used by the framework and clk provider respectively.
4074 struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
4075 const char *dev_id, const char *con_id)
4078 struct clk_core *core;
4080 /* This is to allow this function to be chained to others */
4081 if (IS_ERR_OR_NULL(hw))
4082 return ERR_CAST(hw);
4085 clk = alloc_clk(core, dev_id, con_id);
4090 if (!try_module_get(core->owner)) {
4092 return ERR_PTR(-ENOENT);
4095 kref_get(&core->ref);
4096 clk_core_link_consumer(core, clk);
4102 * clk_hw_get_clk - get clk consumer given an clk_hw
4103 * @hw: clk_hw associated with the clk being consumed
4104 * @con_id: connection ID string on device
4106 * Returns: new clk consumer
4107 * This is the function to be used by providers which need
4108 * to get a consumer clk and act on the clock element
4109 * Calls to this function must be balanced with calls clk_put()
4111 struct clk *clk_hw_get_clk(struct clk_hw *hw, const char *con_id)
4113 struct device *dev = hw->core->dev;
4114 const char *name = dev ? dev_name(dev) : NULL;
4116 return clk_hw_create_clk(dev, hw, name, con_id);
4118 EXPORT_SYMBOL(clk_hw_get_clk);
4120 static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
4130 *dst_p = dst = kstrdup_const(src, GFP_KERNEL);
4137 static int clk_core_populate_parent_map(struct clk_core *core,
4138 const struct clk_init_data *init)
4140 u8 num_parents = init->num_parents;
4141 const char * const *parent_names = init->parent_names;
4142 const struct clk_hw **parent_hws = init->parent_hws;
4143 const struct clk_parent_data *parent_data = init->parent_data;
4145 struct clk_parent_map *parents, *parent;
4151 * Avoid unnecessary string look-ups of clk_core's possible parents by
4152 * having a cache of names/clk_hw pointers to clk_core pointers.
4154 parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
4155 core->parents = parents;
4159 /* Copy everything over because it might be __initdata */
4160 for (i = 0, parent = parents; i < num_parents; i++, parent++) {
4163 /* throw a WARN if any entries are NULL */
4164 WARN(!parent_names[i],
4165 "%s: invalid NULL in %s's .parent_names\n",
4166 __func__, core->name);
4167 ret = clk_cpy_name(&parent->name, parent_names[i],
4169 } else if (parent_data) {
4170 parent->hw = parent_data[i].hw;
4171 parent->index = parent_data[i].index;
4172 ret = clk_cpy_name(&parent->fw_name,
4173 parent_data[i].fw_name, false);
4175 ret = clk_cpy_name(&parent->name,
4176 parent_data[i].name,
4178 } else if (parent_hws) {
4179 parent->hw = parent_hws[i];
4182 WARN(1, "Must specify parents if num_parents > 0\n");
4187 kfree_const(parents[i].name);
4188 kfree_const(parents[i].fw_name);
4199 static void clk_core_free_parent_map(struct clk_core *core)
4201 int i = core->num_parents;
4203 if (!core->num_parents)
4207 kfree_const(core->parents[i].name);
4208 kfree_const(core->parents[i].fw_name);
4211 kfree(core->parents);
4215 __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
4218 struct clk_core *core;
4219 const struct clk_init_data *init = hw->init;
4222 * The init data is not supposed to be used outside of registration path.
4223 * Set it to NULL so that provider drivers can't use it either and so that
4224 * we catch use of hw->init early on in the core.
4228 core = kzalloc(sizeof(*core), GFP_KERNEL);
4234 core->name = kstrdup_const(init->name, GFP_KERNEL);
4240 if (WARN_ON(!init->ops)) {
4244 core->ops = init->ops;
4246 if (dev && pm_runtime_enabled(dev))
4247 core->rpm_enabled = true;
4250 if (dev && dev->driver)
4251 core->owner = dev->driver->owner;
4253 core->flags = init->flags;
4254 core->num_parents = init->num_parents;
4256 core->max_rate = ULONG_MAX;
4258 ret = clk_core_populate_parent_map(core, init);
4262 INIT_HLIST_HEAD(&core->clks);
4265 * Don't call clk_hw_create_clk() here because that would pin the
4266 * provider module to itself and prevent it from ever being removed.
4268 hw->clk = alloc_clk(core, NULL, NULL);
4269 if (IS_ERR(hw->clk)) {
4270 ret = PTR_ERR(hw->clk);
4271 goto fail_create_clk;
4274 clk_core_link_consumer(core, hw->clk);
4276 ret = __clk_core_init(core);
4281 clk_core_unlink_consumer(hw->clk);
4282 clk_prepare_unlock();
4288 clk_core_free_parent_map(core);
4291 kfree_const(core->name);
4295 return ERR_PTR(ret);
4299 * dev_or_parent_of_node() - Get device node of @dev or @dev's parent
4300 * @dev: Device to get device node of
4302 * Return: device node pointer of @dev, or the device node pointer of
4303 * @dev->parent if dev doesn't have a device node, or NULL if neither
4304 * @dev or @dev->parent have a device node.
4306 static struct device_node *dev_or_parent_of_node(struct device *dev)
4308 struct device_node *np;
4313 np = dev_of_node(dev);
4315 np = dev_of_node(dev->parent);
4321 * clk_register - allocate a new clock, register it and return an opaque cookie
4322 * @dev: device that is registering this clock
4323 * @hw: link to hardware-specific clock data
4325 * clk_register is the *deprecated* interface for populating the clock tree with
4326 * new clock nodes. Use clk_hw_register() instead.
4328 * Returns: a pointer to the newly allocated struct clk which
4329 * cannot be dereferenced by driver code but may be used in conjunction with the
4330 * rest of the clock API. In the event of an error clk_register will return an
4331 * error code; drivers must test for an error code after calling clk_register.
4333 struct clk *clk_register(struct device *dev, struct clk_hw *hw)
4335 return __clk_register(dev, dev_or_parent_of_node(dev), hw);
4337 EXPORT_SYMBOL_GPL(clk_register);
4340 * clk_hw_register - register a clk_hw and return an error code
4341 * @dev: device that is registering this clock
4342 * @hw: link to hardware-specific clock data
4344 * clk_hw_register is the primary interface for populating the clock tree with
4345 * new clock nodes. It returns an integer equal to zero indicating success or
4346 * less than zero indicating failure. Drivers must test for an error code after
4347 * calling clk_hw_register().
4349 int clk_hw_register(struct device *dev, struct clk_hw *hw)
4351 return PTR_ERR_OR_ZERO(__clk_register(dev, dev_or_parent_of_node(dev),
4354 EXPORT_SYMBOL_GPL(clk_hw_register);
4357 * of_clk_hw_register - register a clk_hw and return an error code
4358 * @node: device_node of device that is registering this clock
4359 * @hw: link to hardware-specific clock data
4361 * of_clk_hw_register() is the primary interface for populating the clock tree
4362 * with new clock nodes when a struct device is not available, but a struct
4363 * device_node is. It returns an integer equal to zero indicating success or
4364 * less than zero indicating failure. Drivers must test for an error code after
4365 * calling of_clk_hw_register().
4367 int of_clk_hw_register(struct device_node *node, struct clk_hw *hw)
4369 return PTR_ERR_OR_ZERO(__clk_register(NULL, node, hw));
4371 EXPORT_SYMBOL_GPL(of_clk_hw_register);
4373 /* Free memory allocated for a clock. */
4374 static void __clk_release(struct kref *ref)
4376 struct clk_core *core = container_of(ref, struct clk_core, ref);
4378 lockdep_assert_held(&prepare_lock);
4380 clk_core_free_parent_map(core);
4381 kfree_const(core->name);
4386 * Empty clk_ops for unregistered clocks. These are used temporarily
4387 * after clk_unregister() was called on a clock and until last clock
4388 * consumer calls clk_put() and the struct clk object is freed.
4390 static int clk_nodrv_prepare_enable(struct clk_hw *hw)
4395 static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
4400 static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
4401 unsigned long parent_rate)
4406 static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
4411 static int clk_nodrv_determine_rate(struct clk_hw *hw,
4412 struct clk_rate_request *req)
4417 static const struct clk_ops clk_nodrv_ops = {
4418 .enable = clk_nodrv_prepare_enable,
4419 .disable = clk_nodrv_disable_unprepare,
4420 .prepare = clk_nodrv_prepare_enable,
4421 .unprepare = clk_nodrv_disable_unprepare,
4422 .determine_rate = clk_nodrv_determine_rate,
4423 .set_rate = clk_nodrv_set_rate,
4424 .set_parent = clk_nodrv_set_parent,
4427 static void clk_core_evict_parent_cache_subtree(struct clk_core *root,
4428 const struct clk_core *target)
4431 struct clk_core *child;
4433 for (i = 0; i < root->num_parents; i++)
4434 if (root->parents[i].core == target)
4435 root->parents[i].core = NULL;
4437 hlist_for_each_entry(child, &root->children, child_node)
4438 clk_core_evict_parent_cache_subtree(child, target);
4441 /* Remove this clk from all parent caches */
4442 static void clk_core_evict_parent_cache(struct clk_core *core)
4444 const struct hlist_head **lists;
4445 struct clk_core *root;
4447 lockdep_assert_held(&prepare_lock);
4449 for (lists = all_lists; *lists; lists++)
4450 hlist_for_each_entry(root, *lists, child_node)
4451 clk_core_evict_parent_cache_subtree(root, core);
4456 * clk_unregister - unregister a currently registered clock
4457 * @clk: clock to unregister
4459 void clk_unregister(struct clk *clk)
4461 unsigned long flags;
4462 const struct clk_ops *ops;
4464 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4467 clk_debug_unregister(clk->core);
4471 ops = clk->core->ops;
4472 if (ops == &clk_nodrv_ops) {
4473 pr_err("%s: unregistered clock: %s\n", __func__,
4478 * Assign empty clock ops for consumers that might still hold
4479 * a reference to this clock.
4481 flags = clk_enable_lock();
4482 clk->core->ops = &clk_nodrv_ops;
4483 clk_enable_unlock(flags);
4486 ops->terminate(clk->core->hw);
4488 if (!hlist_empty(&clk->core->children)) {
4489 struct clk_core *child;
4490 struct hlist_node *t;
4492 /* Reparent all children to the orphan list. */
4493 hlist_for_each_entry_safe(child, t, &clk->core->children,
4495 clk_core_set_parent_nolock(child, NULL);
4498 clk_core_evict_parent_cache(clk->core);
4500 hlist_del_init(&clk->core->child_node);
4502 if (clk->core->prepare_count)
4503 pr_warn("%s: unregistering prepared clock: %s\n",
4504 __func__, clk->core->name);
4506 if (clk->core->protect_count)
4507 pr_warn("%s: unregistering protected clock: %s\n",
4508 __func__, clk->core->name);
4510 kref_put(&clk->core->ref, __clk_release);
4513 clk_prepare_unlock();
4515 EXPORT_SYMBOL_GPL(clk_unregister);
4518 * clk_hw_unregister - unregister a currently registered clk_hw
4519 * @hw: hardware-specific clock data to unregister
4521 void clk_hw_unregister(struct clk_hw *hw)
4523 clk_unregister(hw->clk);
4525 EXPORT_SYMBOL_GPL(clk_hw_unregister);
4527 static void devm_clk_unregister_cb(struct device *dev, void *res)
4529 clk_unregister(*(struct clk **)res);
4532 static void devm_clk_hw_unregister_cb(struct device *dev, void *res)
4534 clk_hw_unregister(*(struct clk_hw **)res);
4538 * devm_clk_register - resource managed clk_register()
4539 * @dev: device that is registering this clock
4540 * @hw: link to hardware-specific clock data
4542 * Managed clk_register(). This function is *deprecated*, use devm_clk_hw_register() instead.
4544 * Clocks returned from this function are automatically clk_unregister()ed on
4545 * driver detach. See clk_register() for more information.
4547 struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
4552 clkp = devres_alloc(devm_clk_unregister_cb, sizeof(*clkp), GFP_KERNEL);
4554 return ERR_PTR(-ENOMEM);
4556 clk = clk_register(dev, hw);
4559 devres_add(dev, clkp);
4566 EXPORT_SYMBOL_GPL(devm_clk_register);
4569 * devm_clk_hw_register - resource managed clk_hw_register()
4570 * @dev: device that is registering this clock
4571 * @hw: link to hardware-specific clock data
4573 * Managed clk_hw_register(). Clocks registered by this function are
4574 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
4575 * for more information.
4577 int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
4579 struct clk_hw **hwp;
4582 hwp = devres_alloc(devm_clk_hw_unregister_cb, sizeof(*hwp), GFP_KERNEL);
4586 ret = clk_hw_register(dev, hw);
4589 devres_add(dev, hwp);
4596 EXPORT_SYMBOL_GPL(devm_clk_hw_register);
4598 static void devm_clk_release(struct device *dev, void *res)
4600 clk_put(*(struct clk **)res);
4604 * devm_clk_hw_get_clk - resource managed clk_hw_get_clk()
4605 * @dev: device that is registering this clock
4606 * @hw: clk_hw associated with the clk being consumed
4607 * @con_id: connection ID string on device
4609 * Managed clk_hw_get_clk(). Clocks got with this function are
4610 * automatically clk_put() on driver detach. See clk_put()
4611 * for more information.
4613 struct clk *devm_clk_hw_get_clk(struct device *dev, struct clk_hw *hw,
4619 /* This should not happen because it would mean we have drivers
4620 * passing around clk_hw pointers instead of having the caller use
4621 * proper clk_get() style APIs
4623 WARN_ON_ONCE(dev != hw->core->dev);
4625 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
4627 return ERR_PTR(-ENOMEM);
4629 clk = clk_hw_get_clk(hw, con_id);
4632 devres_add(dev, clkp);
4639 EXPORT_SYMBOL_GPL(devm_clk_hw_get_clk);
4645 void __clk_put(struct clk *clk)
4647 struct module *owner;
4649 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4655 * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
4656 * given user should be balanced with calls to clk_rate_exclusive_put()
4657 * and by that same consumer
4659 if (WARN_ON(clk->exclusive_count)) {
4660 /* We voiced our concern, let's sanitize the situation */
4661 clk->core->protect_count -= (clk->exclusive_count - 1);
4662 clk_core_rate_unprotect(clk->core);
4663 clk->exclusive_count = 0;
4666 hlist_del(&clk->clks_node);
4668 /* If we had any boundaries on that clock, let's drop them. */
4669 if (clk->min_rate > 0 || clk->max_rate < ULONG_MAX)
4670 clk_set_rate_range_nolock(clk, 0, ULONG_MAX);
4672 owner = clk->core->owner;
4673 kref_put(&clk->core->ref, __clk_release);
4675 clk_prepare_unlock();
4682 /*** clk rate change notifiers ***/
4685 * clk_notifier_register - add a clk rate change notifier
4686 * @clk: struct clk * to watch
4687 * @nb: struct notifier_block * with callback info
4689 * Request notification when clk's rate changes. This uses an SRCU
4690 * notifier because we want it to block and notifier unregistrations are
4691 * uncommon. The callbacks associated with the notifier must not
4692 * re-enter into the clk framework by calling any top-level clk APIs;
4693 * this will cause a nested prepare_lock mutex.
4695 * In all notification cases (pre, post and abort rate change) the original
4696 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
4697 * and the new frequency is passed via struct clk_notifier_data.new_rate.
4699 * clk_notifier_register() must be called from non-atomic context.
4700 * Returns -EINVAL if called with null arguments, -ENOMEM upon
4701 * allocation failure; otherwise, passes along the return value of
4702 * srcu_notifier_chain_register().
4704 int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
4706 struct clk_notifier *cn;
4714 /* search the list of notifiers for this clk */
4715 list_for_each_entry(cn, &clk_notifier_list, node)
4719 /* if clk wasn't in the notifier list, allocate new clk_notifier */
4720 cn = kzalloc(sizeof(*cn), GFP_KERNEL);
4725 srcu_init_notifier_head(&cn->notifier_head);
4727 list_add(&cn->node, &clk_notifier_list);
4730 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
4732 clk->core->notifier_count++;
4735 clk_prepare_unlock();
4739 EXPORT_SYMBOL_GPL(clk_notifier_register);
4742 * clk_notifier_unregister - remove a clk rate change notifier
4743 * @clk: struct clk *
4744 * @nb: struct notifier_block * with callback info
4746 * Request no further notification for changes to 'clk' and frees memory
4747 * allocated in clk_notifier_register.
4749 * Returns -EINVAL if called with null arguments; otherwise, passes
4750 * along the return value of srcu_notifier_chain_unregister().
4752 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
4754 struct clk_notifier *cn;
4762 list_for_each_entry(cn, &clk_notifier_list, node) {
4763 if (cn->clk == clk) {
4764 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
4766 clk->core->notifier_count--;
4768 /* XXX the notifier code should handle this better */
4769 if (!cn->notifier_head.head) {
4770 srcu_cleanup_notifier_head(&cn->notifier_head);
4771 list_del(&cn->node);
4778 clk_prepare_unlock();
4782 EXPORT_SYMBOL_GPL(clk_notifier_unregister);
4784 struct clk_notifier_devres {
4786 struct notifier_block *nb;
4789 static void devm_clk_notifier_release(struct device *dev, void *res)
4791 struct clk_notifier_devres *devres = res;
4793 clk_notifier_unregister(devres->clk, devres->nb);
4796 int devm_clk_notifier_register(struct device *dev, struct clk *clk,
4797 struct notifier_block *nb)
4799 struct clk_notifier_devres *devres;
4802 devres = devres_alloc(devm_clk_notifier_release,
4803 sizeof(*devres), GFP_KERNEL);
4808 ret = clk_notifier_register(clk, nb);
4812 devres_add(dev, devres);
4814 devres_free(devres);
4819 EXPORT_SYMBOL_GPL(devm_clk_notifier_register);
4822 static void clk_core_reparent_orphans(void)
4825 clk_core_reparent_orphans_nolock();
4826 clk_prepare_unlock();
4830 * struct of_clk_provider - Clock provider registration structure
4831 * @link: Entry in global list of clock providers
4832 * @node: Pointer to device tree node of clock provider
4833 * @get: Get clock callback. Returns NULL or a struct clk for the
4834 * given clock specifier
4835 * @get_hw: Get clk_hw callback. Returns NULL, ERR_PTR or a
4836 * struct clk_hw for the given clock specifier
4837 * @data: context pointer to be passed into @get callback
4839 struct of_clk_provider {
4840 struct list_head link;
4842 struct device_node *node;
4843 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
4844 struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
4848 extern struct of_device_id __clk_of_table;
4849 static const struct of_device_id __clk_of_table_sentinel
4850 __used __section("__clk_of_table_end");
4852 static LIST_HEAD(of_clk_providers);
4853 static DEFINE_MUTEX(of_clk_mutex);
4855 struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
4860 EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
4862 struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
4866 EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
4868 struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
4870 struct clk_onecell_data *clk_data = data;
4871 unsigned int idx = clkspec->args[0];
4873 if (idx >= clk_data->clk_num) {
4874 pr_err("%s: invalid clock index %u\n", __func__, idx);
4875 return ERR_PTR(-EINVAL);
4878 return clk_data->clks[idx];
4880 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
4883 of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
4885 struct clk_hw_onecell_data *hw_data = data;
4886 unsigned int idx = clkspec->args[0];
4888 if (idx >= hw_data->num) {
4889 pr_err("%s: invalid index %u\n", __func__, idx);
4890 return ERR_PTR(-EINVAL);
4893 return hw_data->hws[idx];
4895 EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
4898 * of_clk_add_provider() - Register a clock provider for a node
4899 * @np: Device node pointer associated with clock provider
4900 * @clk_src_get: callback for decoding clock
4901 * @data: context pointer for @clk_src_get callback.
4903 * This function is *deprecated*. Use of_clk_add_hw_provider() instead.
4905 int of_clk_add_provider(struct device_node *np,
4906 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
4910 struct of_clk_provider *cp;
4916 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
4920 cp->node = of_node_get(np);
4922 cp->get = clk_src_get;
4924 mutex_lock(&of_clk_mutex);
4925 list_add(&cp->link, &of_clk_providers);
4926 mutex_unlock(&of_clk_mutex);
4927 pr_debug("Added clock from %pOF\n", np);
4929 clk_core_reparent_orphans();
4931 ret = of_clk_set_defaults(np, true);
4933 of_clk_del_provider(np);
4935 fwnode_dev_initialized(&np->fwnode, true);
4939 EXPORT_SYMBOL_GPL(of_clk_add_provider);
4942 * of_clk_add_hw_provider() - Register a clock provider for a node
4943 * @np: Device node pointer associated with clock provider
4944 * @get: callback for decoding clk_hw
4945 * @data: context pointer for @get callback.
4947 int of_clk_add_hw_provider(struct device_node *np,
4948 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
4952 struct of_clk_provider *cp;
4958 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
4962 cp->node = of_node_get(np);
4966 mutex_lock(&of_clk_mutex);
4967 list_add(&cp->link, &of_clk_providers);
4968 mutex_unlock(&of_clk_mutex);
4969 pr_debug("Added clk_hw provider from %pOF\n", np);
4971 clk_core_reparent_orphans();
4973 ret = of_clk_set_defaults(np, true);
4975 of_clk_del_provider(np);
4977 fwnode_dev_initialized(&np->fwnode, true);
4981 EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
4983 static void devm_of_clk_release_provider(struct device *dev, void *res)
4985 of_clk_del_provider(*(struct device_node **)res);
4989 * We allow a child device to use its parent device as the clock provider node
4990 * for cases like MFD sub-devices where the child device driver wants to use
4991 * devm_*() APIs but not list the device in DT as a sub-node.
4993 static struct device_node *get_clk_provider_node(struct device *dev)
4995 struct device_node *np, *parent_np;
4998 parent_np = dev->parent ? dev->parent->of_node : NULL;
5000 if (!of_property_present(np, "#clock-cells"))
5001 if (of_property_present(parent_np, "#clock-cells"))
5008 * devm_of_clk_add_hw_provider() - Managed clk provider node registration
5009 * @dev: Device acting as the clock provider (used for DT node and lifetime)
5010 * @get: callback for decoding clk_hw
5011 * @data: context pointer for @get callback
5013 * Registers clock provider for given device's node. If the device has no DT
5014 * node or if the device node lacks of clock provider information (#clock-cells)
5015 * then the parent device's node is scanned for this information. If parent node
5016 * has the #clock-cells then it is used in registration. Provider is
5017 * automatically released at device exit.
5019 * Return: 0 on success or an errno on failure.
5021 int devm_of_clk_add_hw_provider(struct device *dev,
5022 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
5026 struct device_node **ptr, *np;
5029 ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
5034 np = get_clk_provider_node(dev);
5035 ret = of_clk_add_hw_provider(np, get, data);
5038 devres_add(dev, ptr);
5045 EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);
5048 * of_clk_del_provider() - Remove a previously registered clock provider
5049 * @np: Device node pointer associated with clock provider
5051 void of_clk_del_provider(struct device_node *np)
5053 struct of_clk_provider *cp;
5058 mutex_lock(&of_clk_mutex);
5059 list_for_each_entry(cp, &of_clk_providers, link) {
5060 if (cp->node == np) {
5061 list_del(&cp->link);
5062 fwnode_dev_initialized(&np->fwnode, false);
5063 of_node_put(cp->node);
5068 mutex_unlock(&of_clk_mutex);
5070 EXPORT_SYMBOL_GPL(of_clk_del_provider);
5073 * of_parse_clkspec() - Parse a DT clock specifier for a given device node
5074 * @np: device node to parse clock specifier from
5075 * @index: index of phandle to parse clock out of. If index < 0, @name is used
5076 * @name: clock name to find and parse. If name is NULL, the index is used
5077 * @out_args: Result of parsing the clock specifier
5079 * Parses a device node's "clocks" and "clock-names" properties to find the
5080 * phandle and cells for the index or name that is desired. The resulting clock
5081 * specifier is placed into @out_args, or an errno is returned when there's a
5082 * parsing error. The @index argument is ignored if @name is non-NULL.
5086 * phandle1: clock-controller@1 {
5087 * #clock-cells = <2>;
5090 * phandle2: clock-controller@2 {
5091 * #clock-cells = <1>;
5094 * clock-consumer@3 {
5095 * clocks = <&phandle1 1 2 &phandle2 3>;
5096 * clock-names = "name1", "name2";
5099 * To get a device_node for `clock-controller@2' node you may call this
5100 * function a few different ways:
5102 * of_parse_clkspec(clock-consumer@3, -1, "name2", &args);
5103 * of_parse_clkspec(clock-consumer@3, 1, NULL, &args);
5104 * of_parse_clkspec(clock-consumer@3, 1, "name2", &args);
5106 * Return: 0 upon successfully parsing the clock specifier. Otherwise, -ENOENT
5107 * if @name is NULL or -EINVAL if @name is non-NULL and it can't be found in
5108 * the "clock-names" property of @np.
5110 static int of_parse_clkspec(const struct device_node *np, int index,
5111 const char *name, struct of_phandle_args *out_args)
5115 /* Walk up the tree of devices looking for a clock property that matches */
5118 * For named clocks, first look up the name in the
5119 * "clock-names" property. If it cannot be found, then index
5120 * will be an error code and of_parse_phandle_with_args() will
5124 index = of_property_match_string(np, "clock-names", name);
5125 ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells",
5129 if (name && index >= 0)
5133 * No matching clock found on this node. If the parent node
5134 * has a "clock-ranges" property, then we can try one of its
5138 if (np && !of_get_property(np, "clock-ranges", NULL))
5146 static struct clk_hw *
5147 __of_clk_get_hw_from_provider(struct of_clk_provider *provider,
5148 struct of_phandle_args *clkspec)
5152 if (provider->get_hw)
5153 return provider->get_hw(clkspec, provider->data);
5155 clk = provider->get(clkspec, provider->data);
5157 return ERR_CAST(clk);
5158 return __clk_get_hw(clk);
5161 static struct clk_hw *
5162 of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
5164 struct of_clk_provider *provider;
5165 struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER);
5168 return ERR_PTR(-EINVAL);
5170 mutex_lock(&of_clk_mutex);
5171 list_for_each_entry(provider, &of_clk_providers, link) {
5172 if (provider->node == clkspec->np) {
5173 hw = __of_clk_get_hw_from_provider(provider, clkspec);
5178 mutex_unlock(&of_clk_mutex);
5184 * of_clk_get_from_provider() - Lookup a clock from a clock provider
5185 * @clkspec: pointer to a clock specifier data structure
5187 * This function looks up a struct clk from the registered list of clock
5188 * providers, an input is a clock specifier data structure as returned
5189 * from the of_parse_phandle_with_args() function call.
5191 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
5193 struct clk_hw *hw = of_clk_get_hw_from_clkspec(clkspec);
5195 return clk_hw_create_clk(NULL, hw, NULL, __func__);
5197 EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
5199 struct clk_hw *of_clk_get_hw(struct device_node *np, int index,
5204 struct of_phandle_args clkspec;
5206 ret = of_parse_clkspec(np, index, con_id, &clkspec);
5208 return ERR_PTR(ret);
5210 hw = of_clk_get_hw_from_clkspec(&clkspec);
5211 of_node_put(clkspec.np);
5216 static struct clk *__of_clk_get(struct device_node *np,
5217 int index, const char *dev_id,
5220 struct clk_hw *hw = of_clk_get_hw(np, index, con_id);
5222 return clk_hw_create_clk(NULL, hw, dev_id, con_id);
5225 struct clk *of_clk_get(struct device_node *np, int index)
5227 return __of_clk_get(np, index, np->full_name, NULL);
5229 EXPORT_SYMBOL(of_clk_get);
5232 * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
5233 * @np: pointer to clock consumer node
5234 * @name: name of consumer's clock input, or NULL for the first clock reference
5236 * This function parses the clocks and clock-names properties,
5237 * and uses them to look up the struct clk from the registered list of clock
5240 struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
5243 return ERR_PTR(-ENOENT);
5245 return __of_clk_get(np, 0, np->full_name, name);
5247 EXPORT_SYMBOL(of_clk_get_by_name);
5250 * of_clk_get_parent_count() - Count the number of clocks a device node has
5251 * @np: device node to count
5253 * Returns: The number of clocks that are possible parents of this node
5255 unsigned int of_clk_get_parent_count(const struct device_node *np)
5259 count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
5265 EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
5267 const char *of_clk_get_parent_name(const struct device_node *np, int index)
5269 struct of_phandle_args clkspec;
5270 struct property *prop;
5271 const char *clk_name;
5278 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
5283 index = clkspec.args_count ? clkspec.args[0] : 0;
5286 /* if there is an indices property, use it to transfer the index
5287 * specified into an array offset for the clock-output-names property.
5289 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
5296 /* We went off the end of 'clock-indices' without finding it */
5300 if (of_property_read_string_index(clkspec.np, "clock-output-names",
5304 * Best effort to get the name if the clock has been
5305 * registered with the framework. If the clock isn't
5306 * registered, we return the node name as the name of
5307 * the clock as long as #clock-cells = 0.
5309 clk = of_clk_get_from_provider(&clkspec);
5311 if (clkspec.args_count == 0)
5312 clk_name = clkspec.np->name;
5316 clk_name = __clk_get_name(clk);
5322 of_node_put(clkspec.np);
5325 EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
5328 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
5330 * @np: Device node pointer associated with clock provider
5331 * @parents: pointer to char array that hold the parents' names
5332 * @size: size of the @parents array
5334 * Return: number of parents for the clock node.
5336 int of_clk_parent_fill(struct device_node *np, const char **parents,
5341 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
5346 EXPORT_SYMBOL_GPL(of_clk_parent_fill);
5348 struct clock_provider {
5349 void (*clk_init_cb)(struct device_node *);
5350 struct device_node *np;
5351 struct list_head node;
5355 * This function looks for a parent clock. If there is one, then it
5356 * checks that the provider for this parent clock was initialized, in
5357 * this case the parent clock will be ready.
5359 static int parent_ready(struct device_node *np)
5364 struct clk *clk = of_clk_get(np, i);
5366 /* this parent is ready we can check the next one */
5373 /* at least one parent is not ready, we exit now */
5374 if (PTR_ERR(clk) == -EPROBE_DEFER)
5378 * Here we make assumption that the device tree is
5379 * written correctly. So an error means that there is
5380 * no more parent. As we didn't exit yet, then the
5381 * previous parent are ready. If there is no clock
5382 * parent, no need to wait for them, then we can
5383 * consider their absence as being ready
5390 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
5391 * @np: Device node pointer associated with clock provider
5392 * @index: clock index
5393 * @flags: pointer to top-level framework flags
5395 * Detects if the clock-critical property exists and, if so, sets the
5396 * corresponding CLK_IS_CRITICAL flag.
5398 * Do not use this function. It exists only for legacy Device Tree
5399 * bindings, such as the one-clock-per-node style that are outdated.
5400 * Those bindings typically put all clock data into .dts and the Linux
5401 * driver has no clock data, thus making it impossible to set this flag
5402 * correctly from the driver. Only those drivers may call
5403 * of_clk_detect_critical from their setup functions.
5405 * Return: error code or zero on success
5407 int of_clk_detect_critical(struct device_node *np, int index,
5408 unsigned long *flags)
5410 struct property *prop;
5417 of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
5419 *flags |= CLK_IS_CRITICAL;
5425 * of_clk_init() - Scan and init clock providers from the DT
5426 * @matches: array of compatible values and init functions for providers.
5428 * This function scans the device tree for matching clock providers
5429 * and calls their initialization functions. It also does it by trying
5430 * to follow the dependencies.
5432 void __init of_clk_init(const struct of_device_id *matches)
5434 const struct of_device_id *match;
5435 struct device_node *np;
5436 struct clock_provider *clk_provider, *next;
5439 LIST_HEAD(clk_provider_list);
5442 matches = &__clk_of_table;
5444 /* First prepare the list of the clocks providers */
5445 for_each_matching_node_and_match(np, matches, &match) {
5446 struct clock_provider *parent;
5448 if (!of_device_is_available(np))
5451 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
5453 list_for_each_entry_safe(clk_provider, next,
5454 &clk_provider_list, node) {
5455 list_del(&clk_provider->node);
5456 of_node_put(clk_provider->np);
5457 kfree(clk_provider);
5463 parent->clk_init_cb = match->data;
5464 parent->np = of_node_get(np);
5465 list_add_tail(&parent->node, &clk_provider_list);
5468 while (!list_empty(&clk_provider_list)) {
5469 is_init_done = false;
5470 list_for_each_entry_safe(clk_provider, next,
5471 &clk_provider_list, node) {
5472 if (force || parent_ready(clk_provider->np)) {
5474 /* Don't populate platform devices */
5475 of_node_set_flag(clk_provider->np,
5478 clk_provider->clk_init_cb(clk_provider->np);
5479 of_clk_set_defaults(clk_provider->np, true);
5481 list_del(&clk_provider->node);
5482 of_node_put(clk_provider->np);
5483 kfree(clk_provider);
5484 is_init_done = true;
5489 * We didn't manage to initialize any of the
5490 * remaining providers during the last loop, so now we
5491 * initialize all the remaining ones unconditionally
5492 * in case the clock parent was not mandatory