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);
424 static void clk_core_fill_parent_index(struct clk_core *core, u8 index)
426 struct clk_parent_map *entry = &core->parents[index];
427 struct clk_core *parent;
430 parent = entry->hw->core;
432 parent = clk_core_get(core, index);
433 if (PTR_ERR(parent) == -ENOENT && entry->name)
434 parent = clk_core_lookup(entry->name);
438 * We have a direct reference but it isn't registered yet?
439 * Orphan it and let clk_reparent() update the orphan status
440 * when the parent is registered.
443 parent = ERR_PTR(-EPROBE_DEFER);
445 /* Only cache it if it's not an error */
447 entry->core = parent;
450 static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
453 if (!core || index >= core->num_parents || !core->parents)
456 if (!core->parents[index].core)
457 clk_core_fill_parent_index(core, index);
459 return core->parents[index].core;
463 clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
465 struct clk_core *parent;
467 parent = clk_core_get_parent_by_index(hw->core, index);
469 return !parent ? NULL : parent->hw;
471 EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
473 unsigned int __clk_get_enable_count(struct clk *clk)
475 return !clk ? 0 : clk->core->enable_count;
478 static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
483 if (!core->num_parents || core->parent)
487 * Clk must have a parent because num_parents > 0 but the parent isn't
488 * known yet. Best to return 0 as the rate of this clk until we can
489 * properly recalc the rate based on the parent's rate.
494 unsigned long clk_hw_get_rate(const struct clk_hw *hw)
496 return clk_core_get_rate_nolock(hw->core);
498 EXPORT_SYMBOL_GPL(clk_hw_get_rate);
500 static unsigned long clk_core_get_accuracy_no_lock(struct clk_core *core)
505 return core->accuracy;
508 unsigned long clk_hw_get_flags(const struct clk_hw *hw)
510 return hw->core->flags;
512 EXPORT_SYMBOL_GPL(clk_hw_get_flags);
514 bool clk_hw_is_prepared(const struct clk_hw *hw)
516 return clk_core_is_prepared(hw->core);
518 EXPORT_SYMBOL_GPL(clk_hw_is_prepared);
520 bool clk_hw_rate_is_protected(const struct clk_hw *hw)
522 return clk_core_rate_is_protected(hw->core);
524 EXPORT_SYMBOL_GPL(clk_hw_rate_is_protected);
526 bool clk_hw_is_enabled(const struct clk_hw *hw)
528 return clk_core_is_enabled(hw->core);
530 EXPORT_SYMBOL_GPL(clk_hw_is_enabled);
532 bool __clk_is_enabled(struct clk *clk)
537 return clk_core_is_enabled(clk->core);
539 EXPORT_SYMBOL_GPL(__clk_is_enabled);
541 static bool mux_is_better_rate(unsigned long rate, unsigned long now,
542 unsigned long best, unsigned long flags)
544 if (flags & CLK_MUX_ROUND_CLOSEST)
545 return abs(now - rate) < abs(best - rate);
547 return now <= rate && now > best;
550 static void clk_core_init_rate_req(struct clk_core * const core,
551 struct clk_rate_request *req,
554 static int clk_core_round_rate_nolock(struct clk_core *core,
555 struct clk_rate_request *req);
557 static bool clk_core_has_parent(struct clk_core *core, const struct clk_core *parent)
559 struct clk_core *tmp;
562 /* Optimize for the case where the parent is already the parent. */
563 if (core->parent == parent)
566 for (i = 0; i < core->num_parents; i++) {
567 tmp = clk_core_get_parent_by_index(core, i);
579 clk_core_forward_rate_req(struct clk_core *core,
580 const struct clk_rate_request *old_req,
581 struct clk_core *parent,
582 struct clk_rate_request *req,
583 unsigned long parent_rate)
585 if (WARN_ON(!clk_core_has_parent(core, parent)))
588 clk_core_init_rate_req(parent, req, parent_rate);
590 if (req->min_rate < old_req->min_rate)
591 req->min_rate = old_req->min_rate;
593 if (req->max_rate > old_req->max_rate)
594 req->max_rate = old_req->max_rate;
597 int clk_mux_determine_rate_flags(struct clk_hw *hw,
598 struct clk_rate_request *req,
601 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
602 int i, num_parents, ret;
603 unsigned long best = 0;
605 /* if NO_REPARENT flag set, pass through to current parent */
606 if (core->flags & CLK_SET_RATE_NO_REPARENT) {
607 parent = core->parent;
608 if (core->flags & CLK_SET_RATE_PARENT) {
609 struct clk_rate_request parent_req;
616 clk_core_forward_rate_req(core, req, parent, &parent_req, req->rate);
618 trace_clk_rate_request_start(&parent_req);
620 ret = clk_core_round_rate_nolock(parent, &parent_req);
624 trace_clk_rate_request_done(&parent_req);
626 best = parent_req.rate;
628 best = clk_core_get_rate_nolock(parent);
630 best = clk_core_get_rate_nolock(core);
636 /* find the parent that can provide the fastest rate <= rate */
637 num_parents = core->num_parents;
638 for (i = 0; i < num_parents; i++) {
639 unsigned long parent_rate;
641 parent = clk_core_get_parent_by_index(core, i);
645 if (core->flags & CLK_SET_RATE_PARENT) {
646 struct clk_rate_request parent_req;
648 clk_core_forward_rate_req(core, req, parent, &parent_req, req->rate);
650 trace_clk_rate_request_start(&parent_req);
652 ret = clk_core_round_rate_nolock(parent, &parent_req);
656 trace_clk_rate_request_done(&parent_req);
658 parent_rate = parent_req.rate;
660 parent_rate = clk_core_get_rate_nolock(parent);
663 if (mux_is_better_rate(req->rate, parent_rate,
665 best_parent = parent;
675 req->best_parent_hw = best_parent->hw;
676 req->best_parent_rate = best;
681 EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);
683 struct clk *__clk_lookup(const char *name)
685 struct clk_core *core = clk_core_lookup(name);
687 return !core ? NULL : core->hw->clk;
690 static void clk_core_get_boundaries(struct clk_core *core,
691 unsigned long *min_rate,
692 unsigned long *max_rate)
694 struct clk *clk_user;
696 lockdep_assert_held(&prepare_lock);
698 *min_rate = core->min_rate;
699 *max_rate = core->max_rate;
701 hlist_for_each_entry(clk_user, &core->clks, clks_node)
702 *min_rate = max(*min_rate, clk_user->min_rate);
704 hlist_for_each_entry(clk_user, &core->clks, clks_node)
705 *max_rate = min(*max_rate, clk_user->max_rate);
709 * clk_hw_get_rate_range() - returns the clock rate range for a hw clk
710 * @hw: the hw clk we want to get the range from
711 * @min_rate: pointer to the variable that will hold the minimum
712 * @max_rate: pointer to the variable that will hold the maximum
714 * Fills the @min_rate and @max_rate variables with the minimum and
715 * maximum that clock can reach.
717 void clk_hw_get_rate_range(struct clk_hw *hw, unsigned long *min_rate,
718 unsigned long *max_rate)
720 clk_core_get_boundaries(hw->core, min_rate, max_rate);
722 EXPORT_SYMBOL_GPL(clk_hw_get_rate_range);
724 static bool clk_core_check_boundaries(struct clk_core *core,
725 unsigned long min_rate,
726 unsigned long max_rate)
730 lockdep_assert_held(&prepare_lock);
732 if (min_rate > core->max_rate || max_rate < core->min_rate)
735 hlist_for_each_entry(user, &core->clks, clks_node)
736 if (min_rate > user->max_rate || max_rate < user->min_rate)
742 void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
743 unsigned long max_rate)
745 hw->core->min_rate = min_rate;
746 hw->core->max_rate = max_rate;
748 EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
751 * __clk_mux_determine_rate - clk_ops::determine_rate implementation for a mux type clk
752 * @hw: mux type clk to determine rate on
753 * @req: rate request, also used to return preferred parent and frequencies
755 * Helper for finding best parent to provide a given frequency. This can be used
756 * directly as a determine_rate callback (e.g. for a mux), or from a more
757 * complex clock that may combine a mux with other operations.
759 * Returns: 0 on success, -EERROR value on error
761 int __clk_mux_determine_rate(struct clk_hw *hw,
762 struct clk_rate_request *req)
764 return clk_mux_determine_rate_flags(hw, req, 0);
766 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
768 int __clk_mux_determine_rate_closest(struct clk_hw *hw,
769 struct clk_rate_request *req)
771 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
773 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
777 static void clk_core_rate_unprotect(struct clk_core *core)
779 lockdep_assert_held(&prepare_lock);
784 if (WARN(core->protect_count == 0,
785 "%s already unprotected\n", core->name))
788 if (--core->protect_count > 0)
791 clk_core_rate_unprotect(core->parent);
794 static int clk_core_rate_nuke_protect(struct clk_core *core)
798 lockdep_assert_held(&prepare_lock);
803 if (core->protect_count == 0)
806 ret = core->protect_count;
807 core->protect_count = 1;
808 clk_core_rate_unprotect(core);
814 * clk_rate_exclusive_put - release exclusivity over clock rate control
815 * @clk: the clk over which the exclusivity is released
817 * clk_rate_exclusive_put() completes a critical section during which a clock
818 * consumer cannot tolerate any other consumer making any operation on the
819 * clock which could result in a rate change or rate glitch. Exclusive clocks
820 * cannot have their rate changed, either directly or indirectly due to changes
821 * further up the parent chain of clocks. As a result, clocks up parent chain
822 * also get under exclusive control of the calling consumer.
824 * If exlusivity is claimed more than once on clock, even by the same consumer,
825 * the rate effectively gets locked as exclusivity can't be preempted.
827 * Calls to clk_rate_exclusive_put() must be balanced with calls to
828 * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
831 void clk_rate_exclusive_put(struct clk *clk)
839 * if there is something wrong with this consumer protect count, stop
840 * here before messing with the provider
842 if (WARN_ON(clk->exclusive_count <= 0))
845 clk_core_rate_unprotect(clk->core);
846 clk->exclusive_count--;
848 clk_prepare_unlock();
850 EXPORT_SYMBOL_GPL(clk_rate_exclusive_put);
852 static void clk_core_rate_protect(struct clk_core *core)
854 lockdep_assert_held(&prepare_lock);
859 if (core->protect_count == 0)
860 clk_core_rate_protect(core->parent);
862 core->protect_count++;
865 static void clk_core_rate_restore_protect(struct clk_core *core, int count)
867 lockdep_assert_held(&prepare_lock);
875 clk_core_rate_protect(core);
876 core->protect_count = count;
880 * clk_rate_exclusive_get - get exclusivity over the clk rate control
881 * @clk: the clk over which the exclusity of rate control is requested
883 * clk_rate_exclusive_get() begins a critical section during which a clock
884 * consumer cannot tolerate any other consumer making any operation on the
885 * clock which could result in a rate change or rate glitch. Exclusive clocks
886 * cannot have their rate changed, either directly or indirectly due to changes
887 * further up the parent chain of clocks. As a result, clocks up parent chain
888 * also get under exclusive control of the calling consumer.
890 * If exlusivity is claimed more than once on clock, even by the same consumer,
891 * the rate effectively gets locked as exclusivity can't be preempted.
893 * Calls to clk_rate_exclusive_get() should be balanced with calls to
894 * clk_rate_exclusive_put(). Calls to this function may sleep.
895 * Returns 0 on success, -EERROR otherwise
897 int clk_rate_exclusive_get(struct clk *clk)
903 clk_core_rate_protect(clk->core);
904 clk->exclusive_count++;
905 clk_prepare_unlock();
909 EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
911 static void clk_core_unprepare(struct clk_core *core)
913 lockdep_assert_held(&prepare_lock);
918 if (WARN(core->prepare_count == 0,
919 "%s already unprepared\n", core->name))
922 if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL,
923 "Unpreparing critical %s\n", core->name))
926 if (core->flags & CLK_SET_RATE_GATE)
927 clk_core_rate_unprotect(core);
929 if (--core->prepare_count > 0)
932 WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);
934 trace_clk_unprepare(core);
936 if (core->ops->unprepare)
937 core->ops->unprepare(core->hw);
939 trace_clk_unprepare_complete(core);
940 clk_core_unprepare(core->parent);
941 clk_pm_runtime_put(core);
944 static void clk_core_unprepare_lock(struct clk_core *core)
947 clk_core_unprepare(core);
948 clk_prepare_unlock();
952 * clk_unprepare - undo preparation of a clock source
953 * @clk: the clk being unprepared
955 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
956 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
957 * if the operation may sleep. One example is a clk which is accessed over
958 * I2c. In the complex case a clk gate operation may require a fast and a slow
959 * part. It is this reason that clk_unprepare and clk_disable are not mutually
960 * exclusive. In fact clk_disable must be called before clk_unprepare.
962 void clk_unprepare(struct clk *clk)
964 if (IS_ERR_OR_NULL(clk))
967 clk_core_unprepare_lock(clk->core);
969 EXPORT_SYMBOL_GPL(clk_unprepare);
971 static int clk_core_prepare(struct clk_core *core)
975 lockdep_assert_held(&prepare_lock);
980 if (core->prepare_count == 0) {
981 ret = clk_pm_runtime_get(core);
985 ret = clk_core_prepare(core->parent);
989 trace_clk_prepare(core);
991 if (core->ops->prepare)
992 ret = core->ops->prepare(core->hw);
994 trace_clk_prepare_complete(core);
1000 core->prepare_count++;
1003 * CLK_SET_RATE_GATE is a special case of clock protection
1004 * Instead of a consumer claiming exclusive rate control, it is
1005 * actually the provider which prevents any consumer from making any
1006 * operation which could result in a rate change or rate glitch while
1007 * the clock is prepared.
1009 if (core->flags & CLK_SET_RATE_GATE)
1010 clk_core_rate_protect(core);
1014 clk_core_unprepare(core->parent);
1016 clk_pm_runtime_put(core);
1020 static int clk_core_prepare_lock(struct clk_core *core)
1025 ret = clk_core_prepare(core);
1026 clk_prepare_unlock();
1032 * clk_prepare - prepare a clock source
1033 * @clk: the clk being prepared
1035 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
1036 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
1037 * operation may sleep. One example is a clk which is accessed over I2c. In
1038 * the complex case a clk ungate operation may require a fast and a slow part.
1039 * It is this reason that clk_prepare and clk_enable are not mutually
1040 * exclusive. In fact clk_prepare must be called before clk_enable.
1041 * Returns 0 on success, -EERROR otherwise.
1043 int clk_prepare(struct clk *clk)
1048 return clk_core_prepare_lock(clk->core);
1050 EXPORT_SYMBOL_GPL(clk_prepare);
1052 static void clk_core_disable(struct clk_core *core)
1054 lockdep_assert_held(&enable_lock);
1059 if (WARN(core->enable_count == 0, "%s already disabled\n", core->name))
1062 if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL,
1063 "Disabling critical %s\n", core->name))
1066 if (--core->enable_count > 0)
1069 trace_clk_disable(core);
1071 if (core->ops->disable)
1072 core->ops->disable(core->hw);
1074 trace_clk_disable_complete(core);
1076 clk_core_disable(core->parent);
1079 static void clk_core_disable_lock(struct clk_core *core)
1081 unsigned long flags;
1083 flags = clk_enable_lock();
1084 clk_core_disable(core);
1085 clk_enable_unlock(flags);
1089 * clk_disable - gate a clock
1090 * @clk: the clk being gated
1092 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
1093 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
1094 * clk if the operation is fast and will never sleep. One example is a
1095 * SoC-internal clk which is controlled via simple register writes. In the
1096 * complex case a clk gate operation may require a fast and a slow part. It is
1097 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
1098 * In fact clk_disable must be called before clk_unprepare.
1100 void clk_disable(struct clk *clk)
1102 if (IS_ERR_OR_NULL(clk))
1105 clk_core_disable_lock(clk->core);
1107 EXPORT_SYMBOL_GPL(clk_disable);
1109 static int clk_core_enable(struct clk_core *core)
1113 lockdep_assert_held(&enable_lock);
1118 if (WARN(core->prepare_count == 0,
1119 "Enabling unprepared %s\n", core->name))
1122 if (core->enable_count == 0) {
1123 ret = clk_core_enable(core->parent);
1128 trace_clk_enable(core);
1130 if (core->ops->enable)
1131 ret = core->ops->enable(core->hw);
1133 trace_clk_enable_complete(core);
1136 clk_core_disable(core->parent);
1141 core->enable_count++;
1145 static int clk_core_enable_lock(struct clk_core *core)
1147 unsigned long flags;
1150 flags = clk_enable_lock();
1151 ret = clk_core_enable(core);
1152 clk_enable_unlock(flags);
1158 * clk_gate_restore_context - restore context for poweroff
1159 * @hw: the clk_hw pointer of clock whose state is to be restored
1161 * The clock gate restore context function enables or disables
1162 * the gate clocks based on the enable_count. This is done in cases
1163 * where the clock context is lost and based on the enable_count
1164 * the clock either needs to be enabled/disabled. This
1165 * helps restore the state of gate clocks.
1167 void clk_gate_restore_context(struct clk_hw *hw)
1169 struct clk_core *core = hw->core;
1171 if (core->enable_count)
1172 core->ops->enable(hw);
1174 core->ops->disable(hw);
1176 EXPORT_SYMBOL_GPL(clk_gate_restore_context);
1178 static int clk_core_save_context(struct clk_core *core)
1180 struct clk_core *child;
1183 hlist_for_each_entry(child, &core->children, child_node) {
1184 ret = clk_core_save_context(child);
1189 if (core->ops && core->ops->save_context)
1190 ret = core->ops->save_context(core->hw);
1195 static void clk_core_restore_context(struct clk_core *core)
1197 struct clk_core *child;
1199 if (core->ops && core->ops->restore_context)
1200 core->ops->restore_context(core->hw);
1202 hlist_for_each_entry(child, &core->children, child_node)
1203 clk_core_restore_context(child);
1207 * clk_save_context - save clock context for poweroff
1209 * Saves the context of the clock register for powerstates in which the
1210 * contents of the registers will be lost. Occurs deep within the suspend
1211 * code. Returns 0 on success.
1213 int clk_save_context(void)
1215 struct clk_core *clk;
1218 hlist_for_each_entry(clk, &clk_root_list, child_node) {
1219 ret = clk_core_save_context(clk);
1224 hlist_for_each_entry(clk, &clk_orphan_list, child_node) {
1225 ret = clk_core_save_context(clk);
1232 EXPORT_SYMBOL_GPL(clk_save_context);
1235 * clk_restore_context - restore clock context after poweroff
1237 * Restore the saved clock context upon resume.
1240 void clk_restore_context(void)
1242 struct clk_core *core;
1244 hlist_for_each_entry(core, &clk_root_list, child_node)
1245 clk_core_restore_context(core);
1247 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1248 clk_core_restore_context(core);
1250 EXPORT_SYMBOL_GPL(clk_restore_context);
1253 * clk_enable - ungate a clock
1254 * @clk: the clk being ungated
1256 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
1257 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
1258 * if the operation will never sleep. One example is a SoC-internal clk which
1259 * is controlled via simple register writes. In the complex case a clk ungate
1260 * operation may require a fast and a slow part. It is this reason that
1261 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
1262 * must be called before clk_enable. Returns 0 on success, -EERROR
1265 int clk_enable(struct clk *clk)
1270 return clk_core_enable_lock(clk->core);
1272 EXPORT_SYMBOL_GPL(clk_enable);
1275 * clk_is_enabled_when_prepared - indicate if preparing a clock also enables it.
1276 * @clk: clock source
1278 * Returns true if clk_prepare() implicitly enables the clock, effectively
1279 * making clk_enable()/clk_disable() no-ops, false otherwise.
1281 * This is of interest mainly to power management code where actually
1282 * disabling the clock also requires unpreparing it to have any material
1285 * Regardless of the value returned here, the caller must always invoke
1286 * clk_enable() or clk_prepare_enable() and counterparts for usage counts
1289 bool clk_is_enabled_when_prepared(struct clk *clk)
1291 return clk && !(clk->core->ops->enable && clk->core->ops->disable);
1293 EXPORT_SYMBOL_GPL(clk_is_enabled_when_prepared);
1295 static int clk_core_prepare_enable(struct clk_core *core)
1299 ret = clk_core_prepare_lock(core);
1303 ret = clk_core_enable_lock(core);
1305 clk_core_unprepare_lock(core);
1310 static void clk_core_disable_unprepare(struct clk_core *core)
1312 clk_core_disable_lock(core);
1313 clk_core_unprepare_lock(core);
1316 static void __init clk_unprepare_unused_subtree(struct clk_core *core)
1318 struct clk_core *child;
1320 lockdep_assert_held(&prepare_lock);
1322 hlist_for_each_entry(child, &core->children, child_node)
1323 clk_unprepare_unused_subtree(child);
1325 if (core->prepare_count)
1328 if (core->flags & CLK_IGNORE_UNUSED)
1331 if (clk_pm_runtime_get(core))
1334 if (clk_core_is_prepared(core)) {
1335 trace_clk_unprepare(core);
1336 if (core->ops->unprepare_unused)
1337 core->ops->unprepare_unused(core->hw);
1338 else if (core->ops->unprepare)
1339 core->ops->unprepare(core->hw);
1340 trace_clk_unprepare_complete(core);
1343 clk_pm_runtime_put(core);
1346 static void __init clk_disable_unused_subtree(struct clk_core *core)
1348 struct clk_core *child;
1349 unsigned long flags;
1351 lockdep_assert_held(&prepare_lock);
1353 hlist_for_each_entry(child, &core->children, child_node)
1354 clk_disable_unused_subtree(child);
1356 if (core->flags & CLK_OPS_PARENT_ENABLE)
1357 clk_core_prepare_enable(core->parent);
1359 if (clk_pm_runtime_get(core))
1362 flags = clk_enable_lock();
1364 if (core->enable_count)
1367 if (core->flags & CLK_IGNORE_UNUSED)
1371 * some gate clocks have special needs during the disable-unused
1372 * sequence. call .disable_unused if available, otherwise fall
1375 if (clk_core_is_enabled(core)) {
1376 trace_clk_disable(core);
1377 if (core->ops->disable_unused)
1378 core->ops->disable_unused(core->hw);
1379 else if (core->ops->disable)
1380 core->ops->disable(core->hw);
1381 trace_clk_disable_complete(core);
1385 clk_enable_unlock(flags);
1386 clk_pm_runtime_put(core);
1388 if (core->flags & CLK_OPS_PARENT_ENABLE)
1389 clk_core_disable_unprepare(core->parent);
1392 static bool clk_ignore_unused __initdata;
1393 static int __init clk_ignore_unused_setup(char *__unused)
1395 clk_ignore_unused = true;
1398 __setup("clk_ignore_unused", clk_ignore_unused_setup);
1400 static int __init clk_disable_unused(void)
1402 struct clk_core *core;
1404 if (clk_ignore_unused) {
1405 pr_warn("clk: Not disabling unused clocks\n");
1409 pr_info("clk: Disabling unused clocks\n");
1413 hlist_for_each_entry(core, &clk_root_list, child_node)
1414 clk_disable_unused_subtree(core);
1416 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1417 clk_disable_unused_subtree(core);
1419 hlist_for_each_entry(core, &clk_root_list, child_node)
1420 clk_unprepare_unused_subtree(core);
1422 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1423 clk_unprepare_unused_subtree(core);
1425 clk_prepare_unlock();
1429 late_initcall_sync(clk_disable_unused);
1431 static int clk_core_determine_round_nolock(struct clk_core *core,
1432 struct clk_rate_request *req)
1436 lockdep_assert_held(&prepare_lock);
1442 * Some clock providers hand-craft their clk_rate_requests and
1443 * might not fill min_rate and max_rate.
1445 * If it's the case, clamping the rate is equivalent to setting
1446 * the rate to 0 which is bad. Skip the clamping but complain so
1447 * that it gets fixed, hopefully.
1449 if (!req->min_rate && !req->max_rate)
1450 pr_warn("%s: %s: clk_rate_request has initialized min or max rate.\n",
1451 __func__, core->name);
1453 req->rate = clamp(req->rate, req->min_rate, req->max_rate);
1456 * At this point, core protection will be disabled
1457 * - if the provider is not protected at all
1458 * - if the calling consumer is the only one which has exclusivity
1461 if (clk_core_rate_is_protected(core)) {
1462 req->rate = core->rate;
1463 } else if (core->ops->determine_rate) {
1464 return core->ops->determine_rate(core->hw, req);
1465 } else if (core->ops->round_rate) {
1466 rate = core->ops->round_rate(core->hw, req->rate,
1467 &req->best_parent_rate);
1479 static void clk_core_init_rate_req(struct clk_core * const core,
1480 struct clk_rate_request *req,
1483 struct clk_core *parent;
1488 memset(req, 0, sizeof(*req));
1489 req->max_rate = ULONG_MAX;
1496 clk_core_get_boundaries(core, &req->min_rate, &req->max_rate);
1498 parent = core->parent;
1500 req->best_parent_hw = parent->hw;
1501 req->best_parent_rate = parent->rate;
1503 req->best_parent_hw = NULL;
1504 req->best_parent_rate = 0;
1509 * clk_hw_init_rate_request - Initializes a clk_rate_request
1510 * @hw: the clk for which we want to submit a rate request
1511 * @req: the clk_rate_request structure we want to initialise
1512 * @rate: the rate which is to be requested
1514 * Initializes a clk_rate_request structure to submit to
1515 * __clk_determine_rate() or similar functions.
1517 void clk_hw_init_rate_request(const struct clk_hw *hw,
1518 struct clk_rate_request *req,
1521 if (WARN_ON(!hw || !req))
1524 clk_core_init_rate_req(hw->core, req, rate);
1526 EXPORT_SYMBOL_GPL(clk_hw_init_rate_request);
1529 * clk_hw_forward_rate_request - Forwards a clk_rate_request to a clock's parent
1530 * @hw: the original clock that got the rate request
1531 * @old_req: the original clk_rate_request structure we want to forward
1532 * @parent: the clk we want to forward @old_req to
1533 * @req: the clk_rate_request structure we want to initialise
1534 * @parent_rate: The rate which is to be requested to @parent
1536 * Initializes a clk_rate_request structure to submit to a clock parent
1537 * in __clk_determine_rate() or similar functions.
1539 void clk_hw_forward_rate_request(const struct clk_hw *hw,
1540 const struct clk_rate_request *old_req,
1541 const struct clk_hw *parent,
1542 struct clk_rate_request *req,
1543 unsigned long parent_rate)
1545 if (WARN_ON(!hw || !old_req || !parent || !req))
1548 clk_core_forward_rate_req(hw->core, old_req,
1553 static bool clk_core_can_round(struct clk_core * const core)
1555 return core->ops->determine_rate || core->ops->round_rate;
1558 static int clk_core_round_rate_nolock(struct clk_core *core,
1559 struct clk_rate_request *req)
1563 lockdep_assert_held(&prepare_lock);
1570 if (clk_core_can_round(core))
1571 return clk_core_determine_round_nolock(core, req);
1573 if (core->flags & CLK_SET_RATE_PARENT) {
1574 struct clk_rate_request parent_req;
1576 clk_core_forward_rate_req(core, req, core->parent, &parent_req, req->rate);
1578 trace_clk_rate_request_start(&parent_req);
1580 ret = clk_core_round_rate_nolock(core->parent, &parent_req);
1584 trace_clk_rate_request_done(&parent_req);
1586 req->best_parent_rate = parent_req.rate;
1587 req->rate = parent_req.rate;
1592 req->rate = core->rate;
1597 * __clk_determine_rate - get the closest rate actually supported by a clock
1598 * @hw: determine the rate of this clock
1599 * @req: target rate request
1601 * Useful for clk_ops such as .set_rate and .determine_rate.
1603 int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
1610 return clk_core_round_rate_nolock(hw->core, req);
1612 EXPORT_SYMBOL_GPL(__clk_determine_rate);
1615 * clk_hw_round_rate() - round the given rate for a hw clk
1616 * @hw: the hw clk for which we are rounding a rate
1617 * @rate: the rate which is to be rounded
1619 * Takes in a rate as input and rounds it to a rate that the clk can actually
1622 * Context: prepare_lock must be held.
1623 * For clk providers to call from within clk_ops such as .round_rate,
1626 * Return: returns rounded rate of hw clk if clk supports round_rate operation
1627 * else returns the parent rate.
1629 unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
1632 struct clk_rate_request req;
1634 clk_core_init_rate_req(hw->core, &req, rate);
1636 trace_clk_rate_request_start(&req);
1638 ret = clk_core_round_rate_nolock(hw->core, &req);
1642 trace_clk_rate_request_done(&req);
1646 EXPORT_SYMBOL_GPL(clk_hw_round_rate);
1649 * clk_round_rate - round the given rate for a clk
1650 * @clk: the clk for which we are rounding a rate
1651 * @rate: the rate which is to be rounded
1653 * Takes in a rate as input and rounds it to a rate that the clk can actually
1654 * use which is then returned. If clk doesn't support round_rate operation
1655 * then the parent rate is returned.
1657 long clk_round_rate(struct clk *clk, unsigned long rate)
1659 struct clk_rate_request req;
1667 if (clk->exclusive_count)
1668 clk_core_rate_unprotect(clk->core);
1670 clk_core_init_rate_req(clk->core, &req, rate);
1672 trace_clk_rate_request_start(&req);
1674 ret = clk_core_round_rate_nolock(clk->core, &req);
1676 trace_clk_rate_request_done(&req);
1678 if (clk->exclusive_count)
1679 clk_core_rate_protect(clk->core);
1681 clk_prepare_unlock();
1688 EXPORT_SYMBOL_GPL(clk_round_rate);
1691 * __clk_notify - call clk notifier chain
1692 * @core: clk that is changing rate
1693 * @msg: clk notifier type (see include/linux/clk.h)
1694 * @old_rate: old clk rate
1695 * @new_rate: new clk rate
1697 * Triggers a notifier call chain on the clk rate-change notification
1698 * for 'clk'. Passes a pointer to the struct clk and the previous
1699 * and current rates to the notifier callback. Intended to be called by
1700 * internal clock code only. Returns NOTIFY_DONE from the last driver
1701 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1702 * a driver returns that.
1704 static int __clk_notify(struct clk_core *core, unsigned long msg,
1705 unsigned long old_rate, unsigned long new_rate)
1707 struct clk_notifier *cn;
1708 struct clk_notifier_data cnd;
1709 int ret = NOTIFY_DONE;
1711 cnd.old_rate = old_rate;
1712 cnd.new_rate = new_rate;
1714 list_for_each_entry(cn, &clk_notifier_list, node) {
1715 if (cn->clk->core == core) {
1717 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
1719 if (ret & NOTIFY_STOP_MASK)
1728 * __clk_recalc_accuracies
1729 * @core: first clk in the subtree
1731 * Walks the subtree of clks starting with clk and recalculates accuracies as
1732 * it goes. Note that if a clk does not implement the .recalc_accuracy
1733 * callback then it is assumed that the clock will take on the accuracy of its
1736 static void __clk_recalc_accuracies(struct clk_core *core)
1738 unsigned long parent_accuracy = 0;
1739 struct clk_core *child;
1741 lockdep_assert_held(&prepare_lock);
1744 parent_accuracy = core->parent->accuracy;
1746 if (core->ops->recalc_accuracy)
1747 core->accuracy = core->ops->recalc_accuracy(core->hw,
1750 core->accuracy = parent_accuracy;
1752 hlist_for_each_entry(child, &core->children, child_node)
1753 __clk_recalc_accuracies(child);
1756 static long clk_core_get_accuracy_recalc(struct clk_core *core)
1758 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
1759 __clk_recalc_accuracies(core);
1761 return clk_core_get_accuracy_no_lock(core);
1765 * clk_get_accuracy - return the accuracy of clk
1766 * @clk: the clk whose accuracy is being returned
1768 * Simply returns the cached accuracy of the clk, unless
1769 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1771 * If clk is NULL then returns 0.
1773 long clk_get_accuracy(struct clk *clk)
1781 accuracy = clk_core_get_accuracy_recalc(clk->core);
1782 clk_prepare_unlock();
1786 EXPORT_SYMBOL_GPL(clk_get_accuracy);
1788 static unsigned long clk_recalc(struct clk_core *core,
1789 unsigned long parent_rate)
1791 unsigned long rate = parent_rate;
1793 if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
1794 rate = core->ops->recalc_rate(core->hw, parent_rate);
1795 clk_pm_runtime_put(core);
1801 * __clk_recalc_rates
1802 * @core: first clk in the subtree
1803 * @update_req: Whether req_rate should be updated with the new rate
1804 * @msg: notification type (see include/linux/clk.h)
1806 * Walks the subtree of clks starting with clk and recalculates rates as it
1807 * goes. Note that if a clk does not implement the .recalc_rate callback then
1808 * it is assumed that the clock will take on the rate of its parent.
1810 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1813 static void __clk_recalc_rates(struct clk_core *core, bool update_req,
1816 unsigned long old_rate;
1817 unsigned long parent_rate = 0;
1818 struct clk_core *child;
1820 lockdep_assert_held(&prepare_lock);
1822 old_rate = core->rate;
1825 parent_rate = core->parent->rate;
1827 core->rate = clk_recalc(core, parent_rate);
1829 core->req_rate = core->rate;
1832 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1833 * & ABORT_RATE_CHANGE notifiers
1835 if (core->notifier_count && msg)
1836 __clk_notify(core, msg, old_rate, core->rate);
1838 hlist_for_each_entry(child, &core->children, child_node)
1839 __clk_recalc_rates(child, update_req, msg);
1842 static unsigned long clk_core_get_rate_recalc(struct clk_core *core)
1844 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1845 __clk_recalc_rates(core, false, 0);
1847 return clk_core_get_rate_nolock(core);
1851 * clk_get_rate - return the rate of clk
1852 * @clk: the clk whose rate is being returned
1854 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1855 * is set, which means a recalc_rate will be issued. Can be called regardless of
1856 * the clock enabledness. If clk is NULL, or if an error occurred, then returns
1859 unsigned long clk_get_rate(struct clk *clk)
1867 rate = clk_core_get_rate_recalc(clk->core);
1868 clk_prepare_unlock();
1872 EXPORT_SYMBOL_GPL(clk_get_rate);
1874 static int clk_fetch_parent_index(struct clk_core *core,
1875 struct clk_core *parent)
1882 for (i = 0; i < core->num_parents; i++) {
1883 /* Found it first try! */
1884 if (core->parents[i].core == parent)
1887 /* Something else is here, so keep looking */
1888 if (core->parents[i].core)
1891 /* Maybe core hasn't been cached but the hw is all we know? */
1892 if (core->parents[i].hw) {
1893 if (core->parents[i].hw == parent->hw)
1896 /* Didn't match, but we're expecting a clk_hw */
1900 /* Maybe it hasn't been cached (clk_set_parent() path) */
1901 if (parent == clk_core_get(core, i))
1904 /* Fallback to comparing globally unique names */
1905 if (core->parents[i].name &&
1906 !strcmp(parent->name, core->parents[i].name))
1910 if (i == core->num_parents)
1913 core->parents[i].core = parent;
1918 * clk_hw_get_parent_index - return the index of the parent clock
1919 * @hw: clk_hw associated with the clk being consumed
1921 * Fetches and returns the index of parent clock. Returns -EINVAL if the given
1922 * clock does not have a current parent.
1924 int clk_hw_get_parent_index(struct clk_hw *hw)
1926 struct clk_hw *parent = clk_hw_get_parent(hw);
1928 if (WARN_ON(parent == NULL))
1931 return clk_fetch_parent_index(hw->core, parent->core);
1933 EXPORT_SYMBOL_GPL(clk_hw_get_parent_index);
1936 * Update the orphan status of @core and all its children.
1938 static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
1940 struct clk_core *child;
1942 core->orphan = is_orphan;
1944 hlist_for_each_entry(child, &core->children, child_node)
1945 clk_core_update_orphan_status(child, is_orphan);
1948 static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1950 bool was_orphan = core->orphan;
1952 hlist_del(&core->child_node);
1955 bool becomes_orphan = new_parent->orphan;
1957 /* avoid duplicate POST_RATE_CHANGE notifications */
1958 if (new_parent->new_child == core)
1959 new_parent->new_child = NULL;
1961 hlist_add_head(&core->child_node, &new_parent->children);
1963 if (was_orphan != becomes_orphan)
1964 clk_core_update_orphan_status(core, becomes_orphan);
1966 hlist_add_head(&core->child_node, &clk_orphan_list);
1968 clk_core_update_orphan_status(core, true);
1971 core->parent = new_parent;
1974 static struct clk_core *__clk_set_parent_before(struct clk_core *core,
1975 struct clk_core *parent)
1977 unsigned long flags;
1978 struct clk_core *old_parent = core->parent;
1981 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
1983 * 2. Migrate prepare state between parents and prevent race with
1986 * If the clock is not prepared, then a race with
1987 * clk_enable/disable() is impossible since we already have the
1988 * prepare lock (future calls to clk_enable() need to be preceded by
1991 * If the clock is prepared, migrate the prepared state to the new
1992 * parent and also protect against a race with clk_enable() by
1993 * forcing the clock and the new parent on. This ensures that all
1994 * future calls to clk_enable() are practically NOPs with respect to
1995 * hardware and software states.
1997 * See also: Comment for clk_set_parent() below.
2000 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
2001 if (core->flags & CLK_OPS_PARENT_ENABLE) {
2002 clk_core_prepare_enable(old_parent);
2003 clk_core_prepare_enable(parent);
2006 /* migrate prepare count if > 0 */
2007 if (core->prepare_count) {
2008 clk_core_prepare_enable(parent);
2009 clk_core_enable_lock(core);
2012 /* update the clk tree topology */
2013 flags = clk_enable_lock();
2014 clk_reparent(core, parent);
2015 clk_enable_unlock(flags);
2020 static void __clk_set_parent_after(struct clk_core *core,
2021 struct clk_core *parent,
2022 struct clk_core *old_parent)
2025 * Finish the migration of prepare state and undo the changes done
2026 * for preventing a race with clk_enable().
2028 if (core->prepare_count) {
2029 clk_core_disable_lock(core);
2030 clk_core_disable_unprepare(old_parent);
2033 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
2034 if (core->flags & CLK_OPS_PARENT_ENABLE) {
2035 clk_core_disable_unprepare(parent);
2036 clk_core_disable_unprepare(old_parent);
2040 static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
2043 unsigned long flags;
2045 struct clk_core *old_parent;
2047 old_parent = __clk_set_parent_before(core, parent);
2049 trace_clk_set_parent(core, parent);
2051 /* change clock input source */
2052 if (parent && core->ops->set_parent)
2053 ret = core->ops->set_parent(core->hw, p_index);
2055 trace_clk_set_parent_complete(core, parent);
2058 flags = clk_enable_lock();
2059 clk_reparent(core, old_parent);
2060 clk_enable_unlock(flags);
2062 __clk_set_parent_after(core, old_parent, parent);
2067 __clk_set_parent_after(core, parent, old_parent);
2073 * __clk_speculate_rates
2074 * @core: first clk in the subtree
2075 * @parent_rate: the "future" rate of clk's parent
2077 * Walks the subtree of clks starting with clk, speculating rates as it
2078 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
2080 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
2081 * pre-rate change notifications and returns early if no clks in the
2082 * subtree have subscribed to the notifications. Note that if a clk does not
2083 * implement the .recalc_rate callback then it is assumed that the clock will
2084 * take on the rate of its parent.
2086 static int __clk_speculate_rates(struct clk_core *core,
2087 unsigned long parent_rate)
2089 struct clk_core *child;
2090 unsigned long new_rate;
2091 int ret = NOTIFY_DONE;
2093 lockdep_assert_held(&prepare_lock);
2095 new_rate = clk_recalc(core, parent_rate);
2097 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
2098 if (core->notifier_count)
2099 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
2101 if (ret & NOTIFY_STOP_MASK) {
2102 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
2103 __func__, core->name, ret);
2107 hlist_for_each_entry(child, &core->children, child_node) {
2108 ret = __clk_speculate_rates(child, new_rate);
2109 if (ret & NOTIFY_STOP_MASK)
2117 static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
2118 struct clk_core *new_parent, u8 p_index)
2120 struct clk_core *child;
2122 core->new_rate = new_rate;
2123 core->new_parent = new_parent;
2124 core->new_parent_index = p_index;
2125 /* include clk in new parent's PRE_RATE_CHANGE notifications */
2126 core->new_child = NULL;
2127 if (new_parent && new_parent != core->parent)
2128 new_parent->new_child = core;
2130 hlist_for_each_entry(child, &core->children, child_node) {
2131 child->new_rate = clk_recalc(child, new_rate);
2132 clk_calc_subtree(child, child->new_rate, NULL, 0);
2137 * calculate the new rates returning the topmost clock that has to be
2140 static struct clk_core *clk_calc_new_rates(struct clk_core *core,
2143 struct clk_core *top = core;
2144 struct clk_core *old_parent, *parent;
2145 unsigned long best_parent_rate = 0;
2146 unsigned long new_rate;
2147 unsigned long min_rate;
2148 unsigned long max_rate;
2153 if (IS_ERR_OR_NULL(core))
2156 /* save parent rate, if it exists */
2157 parent = old_parent = core->parent;
2159 best_parent_rate = parent->rate;
2161 clk_core_get_boundaries(core, &min_rate, &max_rate);
2163 /* find the closest rate and parent clk/rate */
2164 if (clk_core_can_round(core)) {
2165 struct clk_rate_request req;
2167 clk_core_init_rate_req(core, &req, rate);
2169 trace_clk_rate_request_start(&req);
2171 ret = clk_core_determine_round_nolock(core, &req);
2175 trace_clk_rate_request_done(&req);
2177 best_parent_rate = req.best_parent_rate;
2178 new_rate = req.rate;
2179 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
2181 if (new_rate < min_rate || new_rate > max_rate)
2183 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
2184 /* pass-through clock without adjustable parent */
2185 core->new_rate = core->rate;
2188 /* pass-through clock with adjustable parent */
2189 top = clk_calc_new_rates(parent, rate);
2190 new_rate = parent->new_rate;
2194 /* some clocks must be gated to change parent */
2195 if (parent != old_parent &&
2196 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
2197 pr_debug("%s: %s not gated but wants to reparent\n",
2198 __func__, core->name);
2202 /* try finding the new parent index */
2203 if (parent && core->num_parents > 1) {
2204 p_index = clk_fetch_parent_index(core, parent);
2206 pr_debug("%s: clk %s can not be parent of clk %s\n",
2207 __func__, parent->name, core->name);
2212 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
2213 best_parent_rate != parent->rate)
2214 top = clk_calc_new_rates(parent, best_parent_rate);
2217 clk_calc_subtree(core, new_rate, parent, p_index);
2223 * Notify about rate changes in a subtree. Always walk down the whole tree
2224 * so that in case of an error we can walk down the whole tree again and
2227 static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
2228 unsigned long event)
2230 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
2231 int ret = NOTIFY_DONE;
2233 if (core->rate == core->new_rate)
2236 if (core->notifier_count) {
2237 ret = __clk_notify(core, event, core->rate, core->new_rate);
2238 if (ret & NOTIFY_STOP_MASK)
2242 hlist_for_each_entry(child, &core->children, child_node) {
2243 /* Skip children who will be reparented to another clock */
2244 if (child->new_parent && child->new_parent != core)
2246 tmp_clk = clk_propagate_rate_change(child, event);
2251 /* handle the new child who might not be in core->children yet */
2252 if (core->new_child) {
2253 tmp_clk = clk_propagate_rate_change(core->new_child, event);
2262 * walk down a subtree and set the new rates notifying the rate
2265 static void clk_change_rate(struct clk_core *core)
2267 struct clk_core *child;
2268 struct hlist_node *tmp;
2269 unsigned long old_rate;
2270 unsigned long best_parent_rate = 0;
2271 bool skip_set_rate = false;
2272 struct clk_core *old_parent;
2273 struct clk_core *parent = NULL;
2275 old_rate = core->rate;
2277 if (core->new_parent) {
2278 parent = core->new_parent;
2279 best_parent_rate = core->new_parent->rate;
2280 } else if (core->parent) {
2281 parent = core->parent;
2282 best_parent_rate = core->parent->rate;
2285 if (clk_pm_runtime_get(core))
2288 if (core->flags & CLK_SET_RATE_UNGATE) {
2289 clk_core_prepare(core);
2290 clk_core_enable_lock(core);
2293 if (core->new_parent && core->new_parent != core->parent) {
2294 old_parent = __clk_set_parent_before(core, core->new_parent);
2295 trace_clk_set_parent(core, core->new_parent);
2297 if (core->ops->set_rate_and_parent) {
2298 skip_set_rate = true;
2299 core->ops->set_rate_and_parent(core->hw, core->new_rate,
2301 core->new_parent_index);
2302 } else if (core->ops->set_parent) {
2303 core->ops->set_parent(core->hw, core->new_parent_index);
2306 trace_clk_set_parent_complete(core, core->new_parent);
2307 __clk_set_parent_after(core, core->new_parent, old_parent);
2310 if (core->flags & CLK_OPS_PARENT_ENABLE)
2311 clk_core_prepare_enable(parent);
2313 trace_clk_set_rate(core, core->new_rate);
2315 if (!skip_set_rate && core->ops->set_rate)
2316 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
2318 trace_clk_set_rate_complete(core, core->new_rate);
2320 core->rate = clk_recalc(core, best_parent_rate);
2322 if (core->flags & CLK_SET_RATE_UNGATE) {
2323 clk_core_disable_lock(core);
2324 clk_core_unprepare(core);
2327 if (core->flags & CLK_OPS_PARENT_ENABLE)
2328 clk_core_disable_unprepare(parent);
2330 if (core->notifier_count && old_rate != core->rate)
2331 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
2333 if (core->flags & CLK_RECALC_NEW_RATES)
2334 (void)clk_calc_new_rates(core, core->new_rate);
2337 * Use safe iteration, as change_rate can actually swap parents
2338 * for certain clock types.
2340 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
2341 /* Skip children who will be reparented to another clock */
2342 if (child->new_parent && child->new_parent != core)
2344 clk_change_rate(child);
2347 /* handle the new child who might not be in core->children yet */
2348 if (core->new_child)
2349 clk_change_rate(core->new_child);
2351 clk_pm_runtime_put(core);
2354 static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
2355 unsigned long req_rate)
2358 struct clk_rate_request req;
2360 lockdep_assert_held(&prepare_lock);
2365 /* simulate what the rate would be if it could be freely set */
2366 cnt = clk_core_rate_nuke_protect(core);
2370 clk_core_init_rate_req(core, &req, req_rate);
2372 trace_clk_rate_request_start(&req);
2374 ret = clk_core_round_rate_nolock(core, &req);
2376 trace_clk_rate_request_done(&req);
2378 /* restore the protection */
2379 clk_core_rate_restore_protect(core, cnt);
2381 return ret ? 0 : req.rate;
2384 static int clk_core_set_rate_nolock(struct clk_core *core,
2385 unsigned long req_rate)
2387 struct clk_core *top, *fail_clk;
2394 rate = clk_core_req_round_rate_nolock(core, req_rate);
2396 /* bail early if nothing to do */
2397 if (rate == clk_core_get_rate_nolock(core))
2400 /* fail on a direct rate set of a protected provider */
2401 if (clk_core_rate_is_protected(core))
2404 /* calculate new rates and get the topmost changed clock */
2405 top = clk_calc_new_rates(core, req_rate);
2409 ret = clk_pm_runtime_get(core);
2413 /* notify that we are about to change rates */
2414 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
2416 pr_debug("%s: failed to set %s rate\n", __func__,
2418 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
2423 /* change the rates */
2424 clk_change_rate(top);
2426 core->req_rate = req_rate;
2428 clk_pm_runtime_put(core);
2434 * clk_set_rate - specify a new rate for clk
2435 * @clk: the clk whose rate is being changed
2436 * @rate: the new rate for clk
2438 * In the simplest case clk_set_rate will only adjust the rate of clk.
2440 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
2441 * propagate up to clk's parent; whether or not this happens depends on the
2442 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
2443 * after calling .round_rate then upstream parent propagation is ignored. If
2444 * *parent_rate comes back with a new rate for clk's parent then we propagate
2445 * up to clk's parent and set its rate. Upward propagation will continue
2446 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
2447 * .round_rate stops requesting changes to clk's parent_rate.
2449 * Rate changes are accomplished via tree traversal that also recalculates the
2450 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
2452 * Returns 0 on success, -EERROR otherwise.
2454 int clk_set_rate(struct clk *clk, unsigned long rate)
2461 /* prevent racing with updates to the clock topology */
2464 if (clk->exclusive_count)
2465 clk_core_rate_unprotect(clk->core);
2467 ret = clk_core_set_rate_nolock(clk->core, rate);
2469 if (clk->exclusive_count)
2470 clk_core_rate_protect(clk->core);
2472 clk_prepare_unlock();
2476 EXPORT_SYMBOL_GPL(clk_set_rate);
2479 * clk_set_rate_exclusive - specify a new rate and get exclusive control
2480 * @clk: the clk whose rate is being changed
2481 * @rate: the new rate for clk
2483 * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
2484 * within a critical section
2486 * This can be used initially to ensure that at least 1 consumer is
2487 * satisfied when several consumers are competing for exclusivity over the
2488 * same clock provider.
2490 * The exclusivity is not applied if setting the rate failed.
2492 * Calls to clk_rate_exclusive_get() should be balanced with calls to
2493 * clk_rate_exclusive_put().
2495 * Returns 0 on success, -EERROR otherwise.
2497 int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
2504 /* prevent racing with updates to the clock topology */
2508 * The temporary protection removal is not here, on purpose
2509 * This function is meant to be used instead of clk_rate_protect,
2510 * so before the consumer code path protect the clock provider
2513 ret = clk_core_set_rate_nolock(clk->core, rate);
2515 clk_core_rate_protect(clk->core);
2516 clk->exclusive_count++;
2519 clk_prepare_unlock();
2523 EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
2525 static int clk_set_rate_range_nolock(struct clk *clk,
2530 unsigned long old_min, old_max, rate;
2532 lockdep_assert_held(&prepare_lock);
2537 trace_clk_set_rate_range(clk->core, min, max);
2540 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
2541 __func__, clk->core->name, clk->dev_id, clk->con_id,
2546 if (clk->exclusive_count)
2547 clk_core_rate_unprotect(clk->core);
2549 /* Save the current values in case we need to rollback the change */
2550 old_min = clk->min_rate;
2551 old_max = clk->max_rate;
2552 clk->min_rate = min;
2553 clk->max_rate = max;
2555 if (!clk_core_check_boundaries(clk->core, min, max)) {
2560 rate = clk->core->req_rate;
2561 if (clk->core->flags & CLK_GET_RATE_NOCACHE)
2562 rate = clk_core_get_rate_recalc(clk->core);
2565 * Since the boundaries have been changed, let's give the
2566 * opportunity to the provider to adjust the clock rate based on
2567 * the new boundaries.
2569 * We also need to handle the case where the clock is currently
2570 * outside of the boundaries. Clamping the last requested rate
2571 * to the current minimum and maximum will also handle this.
2574 * There is a catch. It may fail for the usual reason (clock
2575 * broken, clock protected, etc) but also because:
2576 * - round_rate() was not favorable and fell on the wrong
2577 * side of the boundary
2578 * - the determine_rate() callback does not really check for
2579 * this corner case when determining the rate
2581 rate = clamp(rate, min, max);
2582 ret = clk_core_set_rate_nolock(clk->core, rate);
2584 /* rollback the changes */
2585 clk->min_rate = old_min;
2586 clk->max_rate = old_max;
2590 if (clk->exclusive_count)
2591 clk_core_rate_protect(clk->core);
2597 * clk_set_rate_range - set a rate range for a clock source
2598 * @clk: clock source
2599 * @min: desired minimum clock rate in Hz, inclusive
2600 * @max: desired maximum clock rate in Hz, inclusive
2602 * Return: 0 for success or negative errno on failure.
2604 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
2613 ret = clk_set_rate_range_nolock(clk, min, max);
2615 clk_prepare_unlock();
2619 EXPORT_SYMBOL_GPL(clk_set_rate_range);
2622 * clk_set_min_rate - set a minimum clock rate for a clock source
2623 * @clk: clock source
2624 * @rate: desired minimum clock rate in Hz, inclusive
2626 * Returns success (0) or negative errno.
2628 int clk_set_min_rate(struct clk *clk, unsigned long rate)
2633 trace_clk_set_min_rate(clk->core, rate);
2635 return clk_set_rate_range(clk, rate, clk->max_rate);
2637 EXPORT_SYMBOL_GPL(clk_set_min_rate);
2640 * clk_set_max_rate - set a maximum clock rate for a clock source
2641 * @clk: clock source
2642 * @rate: desired maximum clock rate in Hz, inclusive
2644 * Returns success (0) or negative errno.
2646 int clk_set_max_rate(struct clk *clk, unsigned long rate)
2651 trace_clk_set_max_rate(clk->core, rate);
2653 return clk_set_rate_range(clk, clk->min_rate, rate);
2655 EXPORT_SYMBOL_GPL(clk_set_max_rate);
2658 * clk_get_parent - return the parent of a clk
2659 * @clk: the clk whose parent gets returned
2661 * Simply returns clk->parent. Returns NULL if clk is NULL.
2663 struct clk *clk_get_parent(struct clk *clk)
2671 /* TODO: Create a per-user clk and change callers to call clk_put */
2672 parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
2673 clk_prepare_unlock();
2677 EXPORT_SYMBOL_GPL(clk_get_parent);
2679 static struct clk_core *__clk_init_parent(struct clk_core *core)
2683 if (core->num_parents > 1 && core->ops->get_parent)
2684 index = core->ops->get_parent(core->hw);
2686 return clk_core_get_parent_by_index(core, index);
2689 static void clk_core_reparent(struct clk_core *core,
2690 struct clk_core *new_parent)
2692 clk_reparent(core, new_parent);
2693 __clk_recalc_accuracies(core);
2694 __clk_recalc_rates(core, true, POST_RATE_CHANGE);
2697 void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
2702 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
2706 * clk_has_parent - check if a clock is a possible parent for another
2707 * @clk: clock source
2708 * @parent: parent clock source
2710 * This function can be used in drivers that need to check that a clock can be
2711 * the parent of another without actually changing the parent.
2713 * Returns true if @parent is a possible parent for @clk, false otherwise.
2715 bool clk_has_parent(const struct clk *clk, const struct clk *parent)
2717 /* NULL clocks should be nops, so return success if either is NULL. */
2718 if (!clk || !parent)
2721 return clk_core_has_parent(clk->core, parent->core);
2723 EXPORT_SYMBOL_GPL(clk_has_parent);
2725 static int clk_core_set_parent_nolock(struct clk_core *core,
2726 struct clk_core *parent)
2730 unsigned long p_rate = 0;
2732 lockdep_assert_held(&prepare_lock);
2737 if (core->parent == parent)
2740 /* verify ops for multi-parent clks */
2741 if (core->num_parents > 1 && !core->ops->set_parent)
2744 /* check that we are allowed to re-parent if the clock is in use */
2745 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
2748 if (clk_core_rate_is_protected(core))
2751 /* try finding the new parent index */
2753 p_index = clk_fetch_parent_index(core, parent);
2755 pr_debug("%s: clk %s can not be parent of clk %s\n",
2756 __func__, parent->name, core->name);
2759 p_rate = parent->rate;
2762 ret = clk_pm_runtime_get(core);
2766 /* propagate PRE_RATE_CHANGE notifications */
2767 ret = __clk_speculate_rates(core, p_rate);
2769 /* abort if a driver objects */
2770 if (ret & NOTIFY_STOP_MASK)
2773 /* do the re-parent */
2774 ret = __clk_set_parent(core, parent, p_index);
2776 /* propagate rate an accuracy recalculation accordingly */
2778 __clk_recalc_rates(core, true, ABORT_RATE_CHANGE);
2780 __clk_recalc_rates(core, true, POST_RATE_CHANGE);
2781 __clk_recalc_accuracies(core);
2785 clk_pm_runtime_put(core);
2790 int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *parent)
2792 return clk_core_set_parent_nolock(hw->core, parent->core);
2794 EXPORT_SYMBOL_GPL(clk_hw_set_parent);
2797 * clk_set_parent - switch the parent of a mux clk
2798 * @clk: the mux clk whose input we are switching
2799 * @parent: the new input to clk
2801 * Re-parent clk to use parent as its new input source. If clk is in
2802 * prepared state, the clk will get enabled for the duration of this call. If
2803 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2804 * that, the reparenting is glitchy in hardware, etc), use the
2805 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2807 * After successfully changing clk's parent clk_set_parent will update the
2808 * clk topology, sysfs topology and propagate rate recalculation via
2809 * __clk_recalc_rates.
2811 * Returns 0 on success, -EERROR otherwise.
2813 int clk_set_parent(struct clk *clk, struct clk *parent)
2822 if (clk->exclusive_count)
2823 clk_core_rate_unprotect(clk->core);
2825 ret = clk_core_set_parent_nolock(clk->core,
2826 parent ? parent->core : NULL);
2828 if (clk->exclusive_count)
2829 clk_core_rate_protect(clk->core);
2831 clk_prepare_unlock();
2835 EXPORT_SYMBOL_GPL(clk_set_parent);
2837 static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
2841 lockdep_assert_held(&prepare_lock);
2846 if (clk_core_rate_is_protected(core))
2849 trace_clk_set_phase(core, degrees);
2851 if (core->ops->set_phase) {
2852 ret = core->ops->set_phase(core->hw, degrees);
2854 core->phase = degrees;
2857 trace_clk_set_phase_complete(core, degrees);
2863 * clk_set_phase - adjust the phase shift of a clock signal
2864 * @clk: clock signal source
2865 * @degrees: number of degrees the signal is shifted
2867 * Shifts the phase of a clock signal by the specified
2868 * degrees. Returns 0 on success, -EERROR otherwise.
2870 * This function makes no distinction about the input or reference
2871 * signal that we adjust the clock signal phase against. For example
2872 * phase locked-loop clock signal generators we may shift phase with
2873 * respect to feedback clock signal input, but for other cases the
2874 * clock phase may be shifted with respect to some other, unspecified
2877 * Additionally the concept of phase shift does not propagate through
2878 * the clock tree hierarchy, which sets it apart from clock rates and
2879 * clock accuracy. A parent clock phase attribute does not have an
2880 * impact on the phase attribute of a child clock.
2882 int clk_set_phase(struct clk *clk, int degrees)
2889 /* sanity check degrees */
2896 if (clk->exclusive_count)
2897 clk_core_rate_unprotect(clk->core);
2899 ret = clk_core_set_phase_nolock(clk->core, degrees);
2901 if (clk->exclusive_count)
2902 clk_core_rate_protect(clk->core);
2904 clk_prepare_unlock();
2908 EXPORT_SYMBOL_GPL(clk_set_phase);
2910 static int clk_core_get_phase(struct clk_core *core)
2914 lockdep_assert_held(&prepare_lock);
2915 if (!core->ops->get_phase)
2918 /* Always try to update cached phase if possible */
2919 ret = core->ops->get_phase(core->hw);
2927 * clk_get_phase - return the phase shift of a clock signal
2928 * @clk: clock signal source
2930 * Returns the phase shift of a clock node in degrees, otherwise returns
2933 int clk_get_phase(struct clk *clk)
2941 ret = clk_core_get_phase(clk->core);
2942 clk_prepare_unlock();
2946 EXPORT_SYMBOL_GPL(clk_get_phase);
2948 static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
2950 /* Assume a default value of 50% */
2955 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);
2957 static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
2959 struct clk_duty *duty = &core->duty;
2962 if (!core->ops->get_duty_cycle)
2963 return clk_core_update_duty_cycle_parent_nolock(core);
2965 ret = core->ops->get_duty_cycle(core->hw, duty);
2969 /* Don't trust the clock provider too much */
2970 if (duty->den == 0 || duty->num > duty->den) {
2978 clk_core_reset_duty_cycle_nolock(core);
2982 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
2987 core->flags & CLK_DUTY_CYCLE_PARENT) {
2988 ret = clk_core_update_duty_cycle_nolock(core->parent);
2989 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
2991 clk_core_reset_duty_cycle_nolock(core);
2997 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
2998 struct clk_duty *duty);
3000 static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
3001 struct clk_duty *duty)
3005 lockdep_assert_held(&prepare_lock);
3007 if (clk_core_rate_is_protected(core))
3010 trace_clk_set_duty_cycle(core, duty);
3012 if (!core->ops->set_duty_cycle)
3013 return clk_core_set_duty_cycle_parent_nolock(core, duty);
3015 ret = core->ops->set_duty_cycle(core->hw, duty);
3017 memcpy(&core->duty, duty, sizeof(*duty));
3019 trace_clk_set_duty_cycle_complete(core, duty);
3024 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
3025 struct clk_duty *duty)
3030 core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
3031 ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
3032 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
3039 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
3040 * @clk: clock signal source
3041 * @num: numerator of the duty cycle ratio to be applied
3042 * @den: denominator of the duty cycle ratio to be applied
3044 * Apply the duty cycle ratio if the ratio is valid and the clock can
3045 * perform this operation
3047 * Returns (0) on success, a negative errno otherwise.
3049 int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
3052 struct clk_duty duty;
3057 /* sanity check the ratio */
3058 if (den == 0 || num > den)
3066 if (clk->exclusive_count)
3067 clk_core_rate_unprotect(clk->core);
3069 ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
3071 if (clk->exclusive_count)
3072 clk_core_rate_protect(clk->core);
3074 clk_prepare_unlock();
3078 EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
3080 static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
3083 struct clk_duty *duty = &core->duty;
3088 ret = clk_core_update_duty_cycle_nolock(core);
3090 ret = mult_frac(scale, duty->num, duty->den);
3092 clk_prepare_unlock();
3098 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
3099 * @clk: clock signal source
3100 * @scale: scaling factor to be applied to represent the ratio as an integer
3102 * Returns the duty cycle ratio of a clock node multiplied by the provided
3103 * scaling factor, or negative errno on error.
3105 int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
3110 return clk_core_get_scaled_duty_cycle(clk->core, scale);
3112 EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
3115 * clk_is_match - check if two clk's point to the same hardware clock
3116 * @p: clk compared against q
3117 * @q: clk compared against p
3119 * Returns true if the two struct clk pointers both point to the same hardware
3120 * clock node. Put differently, returns true if struct clk *p and struct clk *q
3121 * share the same struct clk_core object.
3123 * Returns false otherwise. Note that two NULL clks are treated as matching.
3125 bool clk_is_match(const struct clk *p, const struct clk *q)
3127 /* trivial case: identical struct clk's or both NULL */
3131 /* true if clk->core pointers match. Avoid dereferencing garbage */
3132 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
3133 if (p->core == q->core)
3138 EXPORT_SYMBOL_GPL(clk_is_match);
3140 /*** debugfs support ***/
3142 #ifdef CONFIG_DEBUG_FS
3143 #include <linux/debugfs.h>
3145 static struct dentry *rootdir;
3146 static int inited = 0;
3147 static DEFINE_MUTEX(clk_debug_lock);
3148 static HLIST_HEAD(clk_debug_list);
3150 static struct hlist_head *orphan_list[] = {
3155 static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
3160 seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu ",
3162 30 - level * 3, c->name,
3163 c->enable_count, c->prepare_count, c->protect_count,
3164 clk_core_get_rate_recalc(c),
3165 clk_core_get_accuracy_recalc(c));
3167 phase = clk_core_get_phase(c);
3169 seq_printf(s, "%5d", phase);
3171 seq_puts(s, "-----");
3173 seq_printf(s, " %6d", clk_core_get_scaled_duty_cycle(c, 100000));
3175 if (c->ops->is_enabled)
3176 seq_printf(s, " %9c\n", clk_core_is_enabled(c) ? 'Y' : 'N');
3177 else if (!c->ops->enable)
3178 seq_printf(s, " %9c\n", 'Y');
3180 seq_printf(s, " %9c\n", '?');
3183 static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
3186 struct clk_core *child;
3188 clk_pm_runtime_get(c);
3189 clk_summary_show_one(s, c, level);
3190 clk_pm_runtime_put(c);
3192 hlist_for_each_entry(child, &c->children, child_node)
3193 clk_summary_show_subtree(s, child, level + 1);
3196 static int clk_summary_show(struct seq_file *s, void *data)
3199 struct hlist_head **lists = s->private;
3201 seq_puts(s, " enable prepare protect duty hardware\n");
3202 seq_puts(s, " clock count count count rate accuracy phase cycle enable\n");
3203 seq_puts(s, "-------------------------------------------------------------------------------------------------------\n");
3207 for (; *lists; lists++)
3208 hlist_for_each_entry(c, *lists, child_node)
3209 clk_summary_show_subtree(s, c, 0);
3211 clk_prepare_unlock();
3215 DEFINE_SHOW_ATTRIBUTE(clk_summary);
3217 static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
3220 unsigned long min_rate, max_rate;
3222 clk_core_get_boundaries(c, &min_rate, &max_rate);
3224 /* This should be JSON format, i.e. elements separated with a comma */
3225 seq_printf(s, "\"%s\": { ", c->name);
3226 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
3227 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
3228 seq_printf(s, "\"protect_count\": %d,", c->protect_count);
3229 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate_recalc(c));
3230 seq_printf(s, "\"min_rate\": %lu,", min_rate);
3231 seq_printf(s, "\"max_rate\": %lu,", max_rate);
3232 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy_recalc(c));
3233 phase = clk_core_get_phase(c);
3235 seq_printf(s, "\"phase\": %d,", phase);
3236 seq_printf(s, "\"duty_cycle\": %u",
3237 clk_core_get_scaled_duty_cycle(c, 100000));
3240 static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
3242 struct clk_core *child;
3244 clk_dump_one(s, c, level);
3246 hlist_for_each_entry(child, &c->children, child_node) {
3248 clk_dump_subtree(s, child, level + 1);
3254 static int clk_dump_show(struct seq_file *s, void *data)
3257 bool first_node = true;
3258 struct hlist_head **lists = s->private;
3263 for (; *lists; lists++) {
3264 hlist_for_each_entry(c, *lists, child_node) {
3268 clk_dump_subtree(s, c, 0);
3272 clk_prepare_unlock();
3277 DEFINE_SHOW_ATTRIBUTE(clk_dump);
3279 #undef CLOCK_ALLOW_WRITE_DEBUGFS
3280 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3282 * This can be dangerous, therefore don't provide any real compile time
3283 * configuration option for this feature.
3284 * People who want to use this will need to modify the source code directly.
3286 static int clk_rate_set(void *data, u64 val)
3288 struct clk_core *core = data;
3292 ret = clk_core_set_rate_nolock(core, val);
3293 clk_prepare_unlock();
3298 #define clk_rate_mode 0644
3300 static int clk_prepare_enable_set(void *data, u64 val)
3302 struct clk_core *core = data;
3306 ret = clk_prepare_enable(core->hw->clk);
3308 clk_disable_unprepare(core->hw->clk);
3313 static int clk_prepare_enable_get(void *data, u64 *val)
3315 struct clk_core *core = data;
3317 *val = core->enable_count && core->prepare_count;
3321 DEFINE_DEBUGFS_ATTRIBUTE(clk_prepare_enable_fops, clk_prepare_enable_get,
3322 clk_prepare_enable_set, "%llu\n");
3325 #define clk_rate_set NULL
3326 #define clk_rate_mode 0444
3329 static int clk_rate_get(void *data, u64 *val)
3331 struct clk_core *core = data;
3334 *val = clk_core_get_rate_recalc(core);
3335 clk_prepare_unlock();
3340 DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops, clk_rate_get, clk_rate_set, "%llu\n");
3342 static const struct {
3346 #define ENTRY(f) { f, #f }
3347 ENTRY(CLK_SET_RATE_GATE),
3348 ENTRY(CLK_SET_PARENT_GATE),
3349 ENTRY(CLK_SET_RATE_PARENT),
3350 ENTRY(CLK_IGNORE_UNUSED),
3351 ENTRY(CLK_GET_RATE_NOCACHE),
3352 ENTRY(CLK_SET_RATE_NO_REPARENT),
3353 ENTRY(CLK_GET_ACCURACY_NOCACHE),
3354 ENTRY(CLK_RECALC_NEW_RATES),
3355 ENTRY(CLK_SET_RATE_UNGATE),
3356 ENTRY(CLK_IS_CRITICAL),
3357 ENTRY(CLK_OPS_PARENT_ENABLE),
3358 ENTRY(CLK_DUTY_CYCLE_PARENT),
3362 static int clk_flags_show(struct seq_file *s, void *data)
3364 struct clk_core *core = s->private;
3365 unsigned long flags = core->flags;
3368 for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
3369 if (flags & clk_flags[i].flag) {
3370 seq_printf(s, "%s\n", clk_flags[i].name);
3371 flags &= ~clk_flags[i].flag;
3376 seq_printf(s, "0x%lx\n", flags);
3381 DEFINE_SHOW_ATTRIBUTE(clk_flags);
3383 static void possible_parent_show(struct seq_file *s, struct clk_core *core,
3384 unsigned int i, char terminator)
3386 struct clk_core *parent;
3389 * Go through the following options to fetch a parent's name.
3391 * 1. Fetch the registered parent clock and use its name
3392 * 2. Use the global (fallback) name if specified
3393 * 3. Use the local fw_name if provided
3394 * 4. Fetch parent clock's clock-output-name if DT index was set
3396 * This may still fail in some cases, such as when the parent is
3397 * specified directly via a struct clk_hw pointer, but it isn't
3400 parent = clk_core_get_parent_by_index(core, i);
3402 seq_puts(s, parent->name);
3403 else if (core->parents[i].name)
3404 seq_puts(s, core->parents[i].name);
3405 else if (core->parents[i].fw_name)
3406 seq_printf(s, "<%s>(fw)", core->parents[i].fw_name);
3407 else if (core->parents[i].index >= 0)
3409 of_clk_get_parent_name(core->of_node,
3410 core->parents[i].index));
3412 seq_puts(s, "(missing)");
3414 seq_putc(s, terminator);
3417 static int possible_parents_show(struct seq_file *s, void *data)
3419 struct clk_core *core = s->private;
3422 for (i = 0; i < core->num_parents - 1; i++)
3423 possible_parent_show(s, core, i, ' ');
3425 possible_parent_show(s, core, i, '\n');
3429 DEFINE_SHOW_ATTRIBUTE(possible_parents);
3431 static int current_parent_show(struct seq_file *s, void *data)
3433 struct clk_core *core = s->private;
3436 seq_printf(s, "%s\n", core->parent->name);
3440 DEFINE_SHOW_ATTRIBUTE(current_parent);
3442 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3443 static ssize_t current_parent_write(struct file *file, const char __user *ubuf,
3444 size_t count, loff_t *ppos)
3446 struct seq_file *s = file->private_data;
3447 struct clk_core *core = s->private;
3448 struct clk_core *parent;
3452 err = kstrtou8_from_user(ubuf, count, 0, &idx);
3456 parent = clk_core_get_parent_by_index(core, idx);
3461 err = clk_core_set_parent_nolock(core, parent);
3462 clk_prepare_unlock();
3469 static const struct file_operations current_parent_rw_fops = {
3470 .open = current_parent_open,
3471 .write = current_parent_write,
3473 .llseek = seq_lseek,
3474 .release = single_release,
3478 static int clk_duty_cycle_show(struct seq_file *s, void *data)
3480 struct clk_core *core = s->private;
3481 struct clk_duty *duty = &core->duty;
3483 seq_printf(s, "%u/%u\n", duty->num, duty->den);
3487 DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
3489 static int clk_min_rate_show(struct seq_file *s, void *data)
3491 struct clk_core *core = s->private;
3492 unsigned long min_rate, max_rate;
3495 clk_core_get_boundaries(core, &min_rate, &max_rate);
3496 clk_prepare_unlock();
3497 seq_printf(s, "%lu\n", min_rate);
3501 DEFINE_SHOW_ATTRIBUTE(clk_min_rate);
3503 static int clk_max_rate_show(struct seq_file *s, void *data)
3505 struct clk_core *core = s->private;
3506 unsigned long min_rate, max_rate;
3509 clk_core_get_boundaries(core, &min_rate, &max_rate);
3510 clk_prepare_unlock();
3511 seq_printf(s, "%lu\n", max_rate);
3515 DEFINE_SHOW_ATTRIBUTE(clk_max_rate);
3517 static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
3519 struct dentry *root;
3521 if (!core || !pdentry)
3524 root = debugfs_create_dir(core->name, pdentry);
3525 core->dentry = root;
3527 debugfs_create_file("clk_rate", clk_rate_mode, root, core,
3529 debugfs_create_file("clk_min_rate", 0444, root, core, &clk_min_rate_fops);
3530 debugfs_create_file("clk_max_rate", 0444, root, core, &clk_max_rate_fops);
3531 debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
3532 debugfs_create_u32("clk_phase", 0444, root, &core->phase);
3533 debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
3534 debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
3535 debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
3536 debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
3537 debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
3538 debugfs_create_file("clk_duty_cycle", 0444, root, core,
3539 &clk_duty_cycle_fops);
3540 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3541 debugfs_create_file("clk_prepare_enable", 0644, root, core,
3542 &clk_prepare_enable_fops);
3544 if (core->num_parents > 1)
3545 debugfs_create_file("clk_parent", 0644, root, core,
3546 ¤t_parent_rw_fops);
3549 if (core->num_parents > 0)
3550 debugfs_create_file("clk_parent", 0444, root, core,
3551 ¤t_parent_fops);
3553 if (core->num_parents > 1)
3554 debugfs_create_file("clk_possible_parents", 0444, root, core,
3555 &possible_parents_fops);
3557 if (core->ops->debug_init)
3558 core->ops->debug_init(core->hw, core->dentry);
3562 * clk_debug_register - add a clk node to the debugfs clk directory
3563 * @core: the clk being added to the debugfs clk directory
3565 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
3566 * initialized. Otherwise it bails out early since the debugfs clk directory
3567 * will be created lazily by clk_debug_init as part of a late_initcall.
3569 static void clk_debug_register(struct clk_core *core)
3571 mutex_lock(&clk_debug_lock);
3572 hlist_add_head(&core->debug_node, &clk_debug_list);
3574 clk_debug_create_one(core, rootdir);
3575 mutex_unlock(&clk_debug_lock);
3579 * clk_debug_unregister - remove a clk node from the debugfs clk directory
3580 * @core: the clk being removed from the debugfs clk directory
3582 * Dynamically removes a clk and all its child nodes from the
3583 * debugfs clk directory if clk->dentry points to debugfs created by
3584 * clk_debug_register in __clk_core_init.
3586 static void clk_debug_unregister(struct clk_core *core)
3588 mutex_lock(&clk_debug_lock);
3589 hlist_del_init(&core->debug_node);
3590 debugfs_remove_recursive(core->dentry);
3591 core->dentry = NULL;
3592 mutex_unlock(&clk_debug_lock);
3596 * clk_debug_init - lazily populate the debugfs clk directory
3598 * clks are often initialized very early during boot before memory can be
3599 * dynamically allocated and well before debugfs is setup. This function
3600 * populates the debugfs clk directory once at boot-time when we know that
3601 * debugfs is setup. It should only be called once at boot-time, all other clks
3602 * added dynamically will be done so with clk_debug_register.
3604 static int __init clk_debug_init(void)
3606 struct clk_core *core;
3608 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3610 pr_warn("********************************************************************\n");
3611 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
3613 pr_warn("** WRITEABLE clk DebugFS SUPPORT HAS BEEN ENABLED IN THIS KERNEL **\n");
3615 pr_warn("** This means that this kernel is built to expose clk operations **\n");
3616 pr_warn("** such as parent or rate setting, enabling, disabling, etc. **\n");
3617 pr_warn("** to userspace, which may compromise security on your system. **\n");
3619 pr_warn("** If you see this message and you are not debugging the **\n");
3620 pr_warn("** kernel, report this immediately to your vendor! **\n");
3622 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
3623 pr_warn("********************************************************************\n");
3626 rootdir = debugfs_create_dir("clk", NULL);
3628 debugfs_create_file("clk_summary", 0444, rootdir, &all_lists,
3630 debugfs_create_file("clk_dump", 0444, rootdir, &all_lists,
3632 debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list,
3634 debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list,
3637 mutex_lock(&clk_debug_lock);
3638 hlist_for_each_entry(core, &clk_debug_list, debug_node)
3639 clk_debug_create_one(core, rootdir);
3642 mutex_unlock(&clk_debug_lock);
3646 late_initcall(clk_debug_init);
3648 static inline void clk_debug_register(struct clk_core *core) { }
3649 static inline void clk_debug_unregister(struct clk_core *core)
3654 static void clk_core_reparent_orphans_nolock(void)
3656 struct clk_core *orphan;
3657 struct hlist_node *tmp2;
3660 * walk the list of orphan clocks and reparent any that newly finds a
3663 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
3664 struct clk_core *parent = __clk_init_parent(orphan);
3667 * We need to use __clk_set_parent_before() and _after() to
3668 * properly migrate any prepare/enable count of the orphan
3669 * clock. This is important for CLK_IS_CRITICAL clocks, which
3670 * are enabled during init but might not have a parent yet.
3673 /* update the clk tree topology */
3674 __clk_set_parent_before(orphan, parent);
3675 __clk_set_parent_after(orphan, parent, NULL);
3676 __clk_recalc_accuracies(orphan);
3677 __clk_recalc_rates(orphan, true, 0);
3680 * __clk_init_parent() will set the initial req_rate to
3681 * 0 if the clock doesn't have clk_ops::recalc_rate and
3682 * is an orphan when it's registered.
3684 * 'req_rate' is used by clk_set_rate_range() and
3685 * clk_put() to trigger a clk_set_rate() call whenever
3686 * the boundaries are modified. Let's make sure
3687 * 'req_rate' is set to something non-zero so that
3688 * clk_set_rate_range() doesn't drop the frequency.
3690 orphan->req_rate = orphan->rate;
3696 * __clk_core_init - initialize the data structures in a struct clk_core
3697 * @core: clk_core being initialized
3699 * Initializes the lists in struct clk_core, queries the hardware for the
3700 * parent and rate and sets them both.
3702 static int __clk_core_init(struct clk_core *core)
3705 struct clk_core *parent;
3712 * Set hw->core after grabbing the prepare_lock to synchronize with
3713 * callers of clk_core_fill_parent_index() where we treat hw->core
3714 * being NULL as the clk not being registered yet. This is crucial so
3715 * that clks aren't parented until their parent is fully registered.
3717 core->hw->core = core;
3719 ret = clk_pm_runtime_get(core);
3723 /* check to see if a clock with this name is already registered */
3724 if (clk_core_lookup(core->name)) {
3725 pr_debug("%s: clk %s already initialized\n",
3726 __func__, core->name);
3731 /* check that clk_ops are sane. See Documentation/driver-api/clk.rst */
3732 if (core->ops->set_rate &&
3733 !((core->ops->round_rate || core->ops->determine_rate) &&
3734 core->ops->recalc_rate)) {
3735 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
3736 __func__, core->name);
3741 if (core->ops->set_parent && !core->ops->get_parent) {
3742 pr_err("%s: %s must implement .get_parent & .set_parent\n",
3743 __func__, core->name);
3748 if (core->num_parents > 1 && !core->ops->get_parent) {
3749 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
3750 __func__, core->name);
3755 if (core->ops->set_rate_and_parent &&
3756 !(core->ops->set_parent && core->ops->set_rate)) {
3757 pr_err("%s: %s must implement .set_parent & .set_rate\n",
3758 __func__, core->name);
3764 * optional platform-specific magic
3766 * The .init callback is not used by any of the basic clock types, but
3767 * exists for weird hardware that must perform initialization magic for
3768 * CCF to get an accurate view of clock for any other callbacks. It may
3769 * also be used needs to perform dynamic allocations. Such allocation
3770 * must be freed in the terminate() callback.
3771 * This callback shall not be used to initialize the parameters state,
3772 * such as rate, parent, etc ...
3774 * If it exist, this callback should called before any other callback of
3777 if (core->ops->init) {
3778 ret = core->ops->init(core->hw);
3783 parent = core->parent = __clk_init_parent(core);
3786 * Populate core->parent if parent has already been clk_core_init'd. If
3787 * parent has not yet been clk_core_init'd then place clk in the orphan
3788 * list. If clk doesn't have any parents then place it in the root
3791 * Every time a new clk is clk_init'd then we walk the list of orphan
3792 * clocks and re-parent any that are children of the clock currently
3796 hlist_add_head(&core->child_node, &parent->children);
3797 core->orphan = parent->orphan;
3798 } else if (!core->num_parents) {
3799 hlist_add_head(&core->child_node, &clk_root_list);
3800 core->orphan = false;
3802 hlist_add_head(&core->child_node, &clk_orphan_list);
3803 core->orphan = true;
3807 * Set clk's accuracy. The preferred method is to use
3808 * .recalc_accuracy. For simple clocks and lazy developers the default
3809 * fallback is to use the parent's accuracy. If a clock doesn't have a
3810 * parent (or is orphaned) then accuracy is set to zero (perfect
3813 if (core->ops->recalc_accuracy)
3814 core->accuracy = core->ops->recalc_accuracy(core->hw,
3815 clk_core_get_accuracy_no_lock(parent));
3817 core->accuracy = parent->accuracy;
3822 * Set clk's phase by clk_core_get_phase() caching the phase.
3823 * Since a phase is by definition relative to its parent, just
3824 * query the current clock phase, or just assume it's in phase.
3826 phase = clk_core_get_phase(core);
3829 pr_warn("%s: Failed to get phase for clk '%s'\n", __func__,
3835 * Set clk's duty cycle.
3837 clk_core_update_duty_cycle_nolock(core);
3840 * Set clk's rate. The preferred method is to use .recalc_rate. For
3841 * simple clocks and lazy developers the default fallback is to use the
3842 * parent's rate. If a clock doesn't have a parent (or is orphaned)
3843 * then rate is set to zero.
3845 if (core->ops->recalc_rate)
3846 rate = core->ops->recalc_rate(core->hw,
3847 clk_core_get_rate_nolock(parent));
3849 rate = parent->rate;
3852 core->rate = core->req_rate = rate;
3855 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
3856 * don't get accidentally disabled when walking the orphan tree and
3857 * reparenting clocks
3859 if (core->flags & CLK_IS_CRITICAL) {
3860 ret = clk_core_prepare(core);
3862 pr_warn("%s: critical clk '%s' failed to prepare\n",
3863 __func__, core->name);
3867 ret = clk_core_enable_lock(core);
3869 pr_warn("%s: critical clk '%s' failed to enable\n",
3870 __func__, core->name);
3871 clk_core_unprepare(core);
3876 clk_core_reparent_orphans_nolock();
3878 kref_init(&core->ref);
3880 clk_pm_runtime_put(core);
3883 hlist_del_init(&core->child_node);
3884 core->hw->core = NULL;
3887 clk_prepare_unlock();
3890 clk_debug_register(core);
3896 * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core
3897 * @core: clk to add consumer to
3898 * @clk: consumer to link to a clk
3900 static void clk_core_link_consumer(struct clk_core *core, struct clk *clk)
3903 hlist_add_head(&clk->clks_node, &core->clks);
3904 clk_prepare_unlock();
3908 * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core
3909 * @clk: consumer to unlink
3911 static void clk_core_unlink_consumer(struct clk *clk)
3913 lockdep_assert_held(&prepare_lock);
3914 hlist_del(&clk->clks_node);
3918 * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core
3919 * @core: clk to allocate a consumer for
3920 * @dev_id: string describing device name
3921 * @con_id: connection ID string on device
3923 * Returns: clk consumer left unlinked from the consumer list
3925 static struct clk *alloc_clk(struct clk_core *core, const char *dev_id,
3930 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
3932 return ERR_PTR(-ENOMEM);
3935 clk->dev_id = dev_id;
3936 clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
3937 clk->max_rate = ULONG_MAX;
3943 * free_clk - Free a clk consumer
3944 * @clk: clk consumer to free
3946 * Note, this assumes the clk has been unlinked from the clk_core consumer
3949 static void free_clk(struct clk *clk)
3951 kfree_const(clk->con_id);
3956 * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given
3958 * @dev: clk consumer device
3959 * @hw: clk_hw associated with the clk being consumed
3960 * @dev_id: string describing device name
3961 * @con_id: connection ID string on device
3963 * This is the main function used to create a clk pointer for use by clk
3964 * consumers. It connects a consumer to the clk_core and clk_hw structures
3965 * used by the framework and clk provider respectively.
3967 struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
3968 const char *dev_id, const char *con_id)
3971 struct clk_core *core;
3973 /* This is to allow this function to be chained to others */
3974 if (IS_ERR_OR_NULL(hw))
3975 return ERR_CAST(hw);
3978 clk = alloc_clk(core, dev_id, con_id);
3983 if (!try_module_get(core->owner)) {
3985 return ERR_PTR(-ENOENT);
3988 kref_get(&core->ref);
3989 clk_core_link_consumer(core, clk);
3995 * clk_hw_get_clk - get clk consumer given an clk_hw
3996 * @hw: clk_hw associated with the clk being consumed
3997 * @con_id: connection ID string on device
3999 * Returns: new clk consumer
4000 * This is the function to be used by providers which need
4001 * to get a consumer clk and act on the clock element
4002 * Calls to this function must be balanced with calls clk_put()
4004 struct clk *clk_hw_get_clk(struct clk_hw *hw, const char *con_id)
4006 struct device *dev = hw->core->dev;
4007 const char *name = dev ? dev_name(dev) : NULL;
4009 return clk_hw_create_clk(dev, hw, name, con_id);
4011 EXPORT_SYMBOL(clk_hw_get_clk);
4013 static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
4023 *dst_p = dst = kstrdup_const(src, GFP_KERNEL);
4030 static int clk_core_populate_parent_map(struct clk_core *core,
4031 const struct clk_init_data *init)
4033 u8 num_parents = init->num_parents;
4034 const char * const *parent_names = init->parent_names;
4035 const struct clk_hw **parent_hws = init->parent_hws;
4036 const struct clk_parent_data *parent_data = init->parent_data;
4038 struct clk_parent_map *parents, *parent;
4044 * Avoid unnecessary string look-ups of clk_core's possible parents by
4045 * having a cache of names/clk_hw pointers to clk_core pointers.
4047 parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
4048 core->parents = parents;
4052 /* Copy everything over because it might be __initdata */
4053 for (i = 0, parent = parents; i < num_parents; i++, parent++) {
4056 /* throw a WARN if any entries are NULL */
4057 WARN(!parent_names[i],
4058 "%s: invalid NULL in %s's .parent_names\n",
4059 __func__, core->name);
4060 ret = clk_cpy_name(&parent->name, parent_names[i],
4062 } else if (parent_data) {
4063 parent->hw = parent_data[i].hw;
4064 parent->index = parent_data[i].index;
4065 ret = clk_cpy_name(&parent->fw_name,
4066 parent_data[i].fw_name, false);
4068 ret = clk_cpy_name(&parent->name,
4069 parent_data[i].name,
4071 } else if (parent_hws) {
4072 parent->hw = parent_hws[i];
4075 WARN(1, "Must specify parents if num_parents > 0\n");
4080 kfree_const(parents[i].name);
4081 kfree_const(parents[i].fw_name);
4092 static void clk_core_free_parent_map(struct clk_core *core)
4094 int i = core->num_parents;
4096 if (!core->num_parents)
4100 kfree_const(core->parents[i].name);
4101 kfree_const(core->parents[i].fw_name);
4104 kfree(core->parents);
4108 __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
4111 struct clk_core *core;
4112 const struct clk_init_data *init = hw->init;
4115 * The init data is not supposed to be used outside of registration path.
4116 * Set it to NULL so that provider drivers can't use it either and so that
4117 * we catch use of hw->init early on in the core.
4121 core = kzalloc(sizeof(*core), GFP_KERNEL);
4127 core->name = kstrdup_const(init->name, GFP_KERNEL);
4133 if (WARN_ON(!init->ops)) {
4137 core->ops = init->ops;
4139 if (dev && pm_runtime_enabled(dev))
4140 core->rpm_enabled = true;
4143 if (dev && dev->driver)
4144 core->owner = dev->driver->owner;
4146 core->flags = init->flags;
4147 core->num_parents = init->num_parents;
4149 core->max_rate = ULONG_MAX;
4151 ret = clk_core_populate_parent_map(core, init);
4155 INIT_HLIST_HEAD(&core->clks);
4158 * Don't call clk_hw_create_clk() here because that would pin the
4159 * provider module to itself and prevent it from ever being removed.
4161 hw->clk = alloc_clk(core, NULL, NULL);
4162 if (IS_ERR(hw->clk)) {
4163 ret = PTR_ERR(hw->clk);
4164 goto fail_create_clk;
4167 clk_core_link_consumer(core, hw->clk);
4169 ret = __clk_core_init(core);
4174 clk_core_unlink_consumer(hw->clk);
4175 clk_prepare_unlock();
4181 clk_core_free_parent_map(core);
4184 kfree_const(core->name);
4188 return ERR_PTR(ret);
4192 * dev_or_parent_of_node() - Get device node of @dev or @dev's parent
4193 * @dev: Device to get device node of
4195 * Return: device node pointer of @dev, or the device node pointer of
4196 * @dev->parent if dev doesn't have a device node, or NULL if neither
4197 * @dev or @dev->parent have a device node.
4199 static struct device_node *dev_or_parent_of_node(struct device *dev)
4201 struct device_node *np;
4206 np = dev_of_node(dev);
4208 np = dev_of_node(dev->parent);
4214 * clk_register - allocate a new clock, register it and return an opaque cookie
4215 * @dev: device that is registering this clock
4216 * @hw: link to hardware-specific clock data
4218 * clk_register is the *deprecated* interface for populating the clock tree with
4219 * new clock nodes. Use clk_hw_register() instead.
4221 * Returns: a pointer to the newly allocated struct clk which
4222 * cannot be dereferenced by driver code but may be used in conjunction with the
4223 * rest of the clock API. In the event of an error clk_register will return an
4224 * error code; drivers must test for an error code after calling clk_register.
4226 struct clk *clk_register(struct device *dev, struct clk_hw *hw)
4228 return __clk_register(dev, dev_or_parent_of_node(dev), hw);
4230 EXPORT_SYMBOL_GPL(clk_register);
4233 * clk_hw_register - register a clk_hw and return an error code
4234 * @dev: device that is registering this clock
4235 * @hw: link to hardware-specific clock data
4237 * clk_hw_register is the primary interface for populating the clock tree with
4238 * new clock nodes. It returns an integer equal to zero indicating success or
4239 * less than zero indicating failure. Drivers must test for an error code after
4240 * calling clk_hw_register().
4242 int clk_hw_register(struct device *dev, struct clk_hw *hw)
4244 return PTR_ERR_OR_ZERO(__clk_register(dev, dev_or_parent_of_node(dev),
4247 EXPORT_SYMBOL_GPL(clk_hw_register);
4250 * of_clk_hw_register - register a clk_hw and return an error code
4251 * @node: device_node of device that is registering this clock
4252 * @hw: link to hardware-specific clock data
4254 * of_clk_hw_register() is the primary interface for populating the clock tree
4255 * with new clock nodes when a struct device is not available, but a struct
4256 * device_node is. It returns an integer equal to zero indicating success or
4257 * less than zero indicating failure. Drivers must test for an error code after
4258 * calling of_clk_hw_register().
4260 int of_clk_hw_register(struct device_node *node, struct clk_hw *hw)
4262 return PTR_ERR_OR_ZERO(__clk_register(NULL, node, hw));
4264 EXPORT_SYMBOL_GPL(of_clk_hw_register);
4266 /* Free memory allocated for a clock. */
4267 static void __clk_release(struct kref *ref)
4269 struct clk_core *core = container_of(ref, struct clk_core, ref);
4271 lockdep_assert_held(&prepare_lock);
4273 clk_core_free_parent_map(core);
4274 kfree_const(core->name);
4279 * Empty clk_ops for unregistered clocks. These are used temporarily
4280 * after clk_unregister() was called on a clock and until last clock
4281 * consumer calls clk_put() and the struct clk object is freed.
4283 static int clk_nodrv_prepare_enable(struct clk_hw *hw)
4288 static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
4293 static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
4294 unsigned long parent_rate)
4299 static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
4304 static const struct clk_ops clk_nodrv_ops = {
4305 .enable = clk_nodrv_prepare_enable,
4306 .disable = clk_nodrv_disable_unprepare,
4307 .prepare = clk_nodrv_prepare_enable,
4308 .unprepare = clk_nodrv_disable_unprepare,
4309 .set_rate = clk_nodrv_set_rate,
4310 .set_parent = clk_nodrv_set_parent,
4313 static void clk_core_evict_parent_cache_subtree(struct clk_core *root,
4314 const struct clk_core *target)
4317 struct clk_core *child;
4319 for (i = 0; i < root->num_parents; i++)
4320 if (root->parents[i].core == target)
4321 root->parents[i].core = NULL;
4323 hlist_for_each_entry(child, &root->children, child_node)
4324 clk_core_evict_parent_cache_subtree(child, target);
4327 /* Remove this clk from all parent caches */
4328 static void clk_core_evict_parent_cache(struct clk_core *core)
4330 const struct hlist_head **lists;
4331 struct clk_core *root;
4333 lockdep_assert_held(&prepare_lock);
4335 for (lists = all_lists; *lists; lists++)
4336 hlist_for_each_entry(root, *lists, child_node)
4337 clk_core_evict_parent_cache_subtree(root, core);
4342 * clk_unregister - unregister a currently registered clock
4343 * @clk: clock to unregister
4345 void clk_unregister(struct clk *clk)
4347 unsigned long flags;
4348 const struct clk_ops *ops;
4350 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4353 clk_debug_unregister(clk->core);
4357 ops = clk->core->ops;
4358 if (ops == &clk_nodrv_ops) {
4359 pr_err("%s: unregistered clock: %s\n", __func__,
4364 * Assign empty clock ops for consumers that might still hold
4365 * a reference to this clock.
4367 flags = clk_enable_lock();
4368 clk->core->ops = &clk_nodrv_ops;
4369 clk_enable_unlock(flags);
4372 ops->terminate(clk->core->hw);
4374 if (!hlist_empty(&clk->core->children)) {
4375 struct clk_core *child;
4376 struct hlist_node *t;
4378 /* Reparent all children to the orphan list. */
4379 hlist_for_each_entry_safe(child, t, &clk->core->children,
4381 clk_core_set_parent_nolock(child, NULL);
4384 clk_core_evict_parent_cache(clk->core);
4386 hlist_del_init(&clk->core->child_node);
4388 if (clk->core->prepare_count)
4389 pr_warn("%s: unregistering prepared clock: %s\n",
4390 __func__, clk->core->name);
4392 if (clk->core->protect_count)
4393 pr_warn("%s: unregistering protected clock: %s\n",
4394 __func__, clk->core->name);
4396 kref_put(&clk->core->ref, __clk_release);
4399 clk_prepare_unlock();
4401 EXPORT_SYMBOL_GPL(clk_unregister);
4404 * clk_hw_unregister - unregister a currently registered clk_hw
4405 * @hw: hardware-specific clock data to unregister
4407 void clk_hw_unregister(struct clk_hw *hw)
4409 clk_unregister(hw->clk);
4411 EXPORT_SYMBOL_GPL(clk_hw_unregister);
4413 static void devm_clk_unregister_cb(struct device *dev, void *res)
4415 clk_unregister(*(struct clk **)res);
4418 static void devm_clk_hw_unregister_cb(struct device *dev, void *res)
4420 clk_hw_unregister(*(struct clk_hw **)res);
4424 * devm_clk_register - resource managed clk_register()
4425 * @dev: device that is registering this clock
4426 * @hw: link to hardware-specific clock data
4428 * Managed clk_register(). This function is *deprecated*, use devm_clk_hw_register() instead.
4430 * Clocks returned from this function are automatically clk_unregister()ed on
4431 * driver detach. See clk_register() for more information.
4433 struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
4438 clkp = devres_alloc(devm_clk_unregister_cb, sizeof(*clkp), GFP_KERNEL);
4440 return ERR_PTR(-ENOMEM);
4442 clk = clk_register(dev, hw);
4445 devres_add(dev, clkp);
4452 EXPORT_SYMBOL_GPL(devm_clk_register);
4455 * devm_clk_hw_register - resource managed clk_hw_register()
4456 * @dev: device that is registering this clock
4457 * @hw: link to hardware-specific clock data
4459 * Managed clk_hw_register(). Clocks registered by this function are
4460 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
4461 * for more information.
4463 int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
4465 struct clk_hw **hwp;
4468 hwp = devres_alloc(devm_clk_hw_unregister_cb, sizeof(*hwp), GFP_KERNEL);
4472 ret = clk_hw_register(dev, hw);
4475 devres_add(dev, hwp);
4482 EXPORT_SYMBOL_GPL(devm_clk_hw_register);
4484 static void devm_clk_release(struct device *dev, void *res)
4486 clk_put(*(struct clk **)res);
4490 * devm_clk_hw_get_clk - resource managed clk_hw_get_clk()
4491 * @dev: device that is registering this clock
4492 * @hw: clk_hw associated with the clk being consumed
4493 * @con_id: connection ID string on device
4495 * Managed clk_hw_get_clk(). Clocks got with this function are
4496 * automatically clk_put() on driver detach. See clk_put()
4497 * for more information.
4499 struct clk *devm_clk_hw_get_clk(struct device *dev, struct clk_hw *hw,
4505 /* This should not happen because it would mean we have drivers
4506 * passing around clk_hw pointers instead of having the caller use
4507 * proper clk_get() style APIs
4509 WARN_ON_ONCE(dev != hw->core->dev);
4511 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
4513 return ERR_PTR(-ENOMEM);
4515 clk = clk_hw_get_clk(hw, con_id);
4518 devres_add(dev, clkp);
4525 EXPORT_SYMBOL_GPL(devm_clk_hw_get_clk);
4531 void __clk_put(struct clk *clk)
4533 struct module *owner;
4535 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4541 * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
4542 * given user should be balanced with calls to clk_rate_exclusive_put()
4543 * and by that same consumer
4545 if (WARN_ON(clk->exclusive_count)) {
4546 /* We voiced our concern, let's sanitize the situation */
4547 clk->core->protect_count -= (clk->exclusive_count - 1);
4548 clk_core_rate_unprotect(clk->core);
4549 clk->exclusive_count = 0;
4552 hlist_del(&clk->clks_node);
4554 /* If we had any boundaries on that clock, let's drop them. */
4555 if (clk->min_rate > 0 || clk->max_rate < ULONG_MAX)
4556 clk_set_rate_range_nolock(clk, 0, ULONG_MAX);
4558 owner = clk->core->owner;
4559 kref_put(&clk->core->ref, __clk_release);
4561 clk_prepare_unlock();
4568 /*** clk rate change notifiers ***/
4571 * clk_notifier_register - add a clk rate change notifier
4572 * @clk: struct clk * to watch
4573 * @nb: struct notifier_block * with callback info
4575 * Request notification when clk's rate changes. This uses an SRCU
4576 * notifier because we want it to block and notifier unregistrations are
4577 * uncommon. The callbacks associated with the notifier must not
4578 * re-enter into the clk framework by calling any top-level clk APIs;
4579 * this will cause a nested prepare_lock mutex.
4581 * In all notification cases (pre, post and abort rate change) the original
4582 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
4583 * and the new frequency is passed via struct clk_notifier_data.new_rate.
4585 * clk_notifier_register() must be called from non-atomic context.
4586 * Returns -EINVAL if called with null arguments, -ENOMEM upon
4587 * allocation failure; otherwise, passes along the return value of
4588 * srcu_notifier_chain_register().
4590 int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
4592 struct clk_notifier *cn;
4600 /* search the list of notifiers for this clk */
4601 list_for_each_entry(cn, &clk_notifier_list, node)
4605 /* if clk wasn't in the notifier list, allocate new clk_notifier */
4606 cn = kzalloc(sizeof(*cn), GFP_KERNEL);
4611 srcu_init_notifier_head(&cn->notifier_head);
4613 list_add(&cn->node, &clk_notifier_list);
4616 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
4618 clk->core->notifier_count++;
4621 clk_prepare_unlock();
4625 EXPORT_SYMBOL_GPL(clk_notifier_register);
4628 * clk_notifier_unregister - remove a clk rate change notifier
4629 * @clk: struct clk *
4630 * @nb: struct notifier_block * with callback info
4632 * Request no further notification for changes to 'clk' and frees memory
4633 * allocated in clk_notifier_register.
4635 * Returns -EINVAL if called with null arguments; otherwise, passes
4636 * along the return value of srcu_notifier_chain_unregister().
4638 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
4640 struct clk_notifier *cn;
4648 list_for_each_entry(cn, &clk_notifier_list, node) {
4649 if (cn->clk == clk) {
4650 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
4652 clk->core->notifier_count--;
4654 /* XXX the notifier code should handle this better */
4655 if (!cn->notifier_head.head) {
4656 srcu_cleanup_notifier_head(&cn->notifier_head);
4657 list_del(&cn->node);
4664 clk_prepare_unlock();
4668 EXPORT_SYMBOL_GPL(clk_notifier_unregister);
4670 struct clk_notifier_devres {
4672 struct notifier_block *nb;
4675 static void devm_clk_notifier_release(struct device *dev, void *res)
4677 struct clk_notifier_devres *devres = res;
4679 clk_notifier_unregister(devres->clk, devres->nb);
4682 int devm_clk_notifier_register(struct device *dev, struct clk *clk,
4683 struct notifier_block *nb)
4685 struct clk_notifier_devres *devres;
4688 devres = devres_alloc(devm_clk_notifier_release,
4689 sizeof(*devres), GFP_KERNEL);
4694 ret = clk_notifier_register(clk, nb);
4699 devres_free(devres);
4704 EXPORT_SYMBOL_GPL(devm_clk_notifier_register);
4707 static void clk_core_reparent_orphans(void)
4710 clk_core_reparent_orphans_nolock();
4711 clk_prepare_unlock();
4715 * struct of_clk_provider - Clock provider registration structure
4716 * @link: Entry in global list of clock providers
4717 * @node: Pointer to device tree node of clock provider
4718 * @get: Get clock callback. Returns NULL or a struct clk for the
4719 * given clock specifier
4720 * @get_hw: Get clk_hw callback. Returns NULL, ERR_PTR or a
4721 * struct clk_hw for the given clock specifier
4722 * @data: context pointer to be passed into @get callback
4724 struct of_clk_provider {
4725 struct list_head link;
4727 struct device_node *node;
4728 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
4729 struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
4733 extern struct of_device_id __clk_of_table;
4734 static const struct of_device_id __clk_of_table_sentinel
4735 __used __section("__clk_of_table_end");
4737 static LIST_HEAD(of_clk_providers);
4738 static DEFINE_MUTEX(of_clk_mutex);
4740 struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
4745 EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
4747 struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
4751 EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
4753 struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
4755 struct clk_onecell_data *clk_data = data;
4756 unsigned int idx = clkspec->args[0];
4758 if (idx >= clk_data->clk_num) {
4759 pr_err("%s: invalid clock index %u\n", __func__, idx);
4760 return ERR_PTR(-EINVAL);
4763 return clk_data->clks[idx];
4765 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
4768 of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
4770 struct clk_hw_onecell_data *hw_data = data;
4771 unsigned int idx = clkspec->args[0];
4773 if (idx >= hw_data->num) {
4774 pr_err("%s: invalid index %u\n", __func__, idx);
4775 return ERR_PTR(-EINVAL);
4778 return hw_data->hws[idx];
4780 EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
4783 * of_clk_add_provider() - Register a clock provider for a node
4784 * @np: Device node pointer associated with clock provider
4785 * @clk_src_get: callback for decoding clock
4786 * @data: context pointer for @clk_src_get callback.
4788 * This function is *deprecated*. Use of_clk_add_hw_provider() instead.
4790 int of_clk_add_provider(struct device_node *np,
4791 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
4795 struct of_clk_provider *cp;
4801 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
4805 cp->node = of_node_get(np);
4807 cp->get = clk_src_get;
4809 mutex_lock(&of_clk_mutex);
4810 list_add(&cp->link, &of_clk_providers);
4811 mutex_unlock(&of_clk_mutex);
4812 pr_debug("Added clock from %pOF\n", np);
4814 clk_core_reparent_orphans();
4816 ret = of_clk_set_defaults(np, true);
4818 of_clk_del_provider(np);
4820 fwnode_dev_initialized(&np->fwnode, true);
4824 EXPORT_SYMBOL_GPL(of_clk_add_provider);
4827 * of_clk_add_hw_provider() - Register a clock provider for a node
4828 * @np: Device node pointer associated with clock provider
4829 * @get: callback for decoding clk_hw
4830 * @data: context pointer for @get callback.
4832 int of_clk_add_hw_provider(struct device_node *np,
4833 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
4837 struct of_clk_provider *cp;
4843 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
4847 cp->node = of_node_get(np);
4851 mutex_lock(&of_clk_mutex);
4852 list_add(&cp->link, &of_clk_providers);
4853 mutex_unlock(&of_clk_mutex);
4854 pr_debug("Added clk_hw provider from %pOF\n", np);
4856 clk_core_reparent_orphans();
4858 ret = of_clk_set_defaults(np, true);
4860 of_clk_del_provider(np);
4862 fwnode_dev_initialized(&np->fwnode, true);
4866 EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
4868 static void devm_of_clk_release_provider(struct device *dev, void *res)
4870 of_clk_del_provider(*(struct device_node **)res);
4874 * We allow a child device to use its parent device as the clock provider node
4875 * for cases like MFD sub-devices where the child device driver wants to use
4876 * devm_*() APIs but not list the device in DT as a sub-node.
4878 static struct device_node *get_clk_provider_node(struct device *dev)
4880 struct device_node *np, *parent_np;
4883 parent_np = dev->parent ? dev->parent->of_node : NULL;
4885 if (!of_property_present(np, "#clock-cells"))
4886 if (of_property_present(parent_np, "#clock-cells"))
4893 * devm_of_clk_add_hw_provider() - Managed clk provider node registration
4894 * @dev: Device acting as the clock provider (used for DT node and lifetime)
4895 * @get: callback for decoding clk_hw
4896 * @data: context pointer for @get callback
4898 * Registers clock provider for given device's node. If the device has no DT
4899 * node or if the device node lacks of clock provider information (#clock-cells)
4900 * then the parent device's node is scanned for this information. If parent node
4901 * has the #clock-cells then it is used in registration. Provider is
4902 * automatically released at device exit.
4904 * Return: 0 on success or an errno on failure.
4906 int devm_of_clk_add_hw_provider(struct device *dev,
4907 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
4911 struct device_node **ptr, *np;
4914 ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
4919 np = get_clk_provider_node(dev);
4920 ret = of_clk_add_hw_provider(np, get, data);
4923 devres_add(dev, ptr);
4930 EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);
4933 * of_clk_del_provider() - Remove a previously registered clock provider
4934 * @np: Device node pointer associated with clock provider
4936 void of_clk_del_provider(struct device_node *np)
4938 struct of_clk_provider *cp;
4943 mutex_lock(&of_clk_mutex);
4944 list_for_each_entry(cp, &of_clk_providers, link) {
4945 if (cp->node == np) {
4946 list_del(&cp->link);
4947 fwnode_dev_initialized(&np->fwnode, false);
4948 of_node_put(cp->node);
4953 mutex_unlock(&of_clk_mutex);
4955 EXPORT_SYMBOL_GPL(of_clk_del_provider);
4958 * of_parse_clkspec() - Parse a DT clock specifier for a given device node
4959 * @np: device node to parse clock specifier from
4960 * @index: index of phandle to parse clock out of. If index < 0, @name is used
4961 * @name: clock name to find and parse. If name is NULL, the index is used
4962 * @out_args: Result of parsing the clock specifier
4964 * Parses a device node's "clocks" and "clock-names" properties to find the
4965 * phandle and cells for the index or name that is desired. The resulting clock
4966 * specifier is placed into @out_args, or an errno is returned when there's a
4967 * parsing error. The @index argument is ignored if @name is non-NULL.
4971 * phandle1: clock-controller@1 {
4972 * #clock-cells = <2>;
4975 * phandle2: clock-controller@2 {
4976 * #clock-cells = <1>;
4979 * clock-consumer@3 {
4980 * clocks = <&phandle1 1 2 &phandle2 3>;
4981 * clock-names = "name1", "name2";
4984 * To get a device_node for `clock-controller@2' node you may call this
4985 * function a few different ways:
4987 * of_parse_clkspec(clock-consumer@3, -1, "name2", &args);
4988 * of_parse_clkspec(clock-consumer@3, 1, NULL, &args);
4989 * of_parse_clkspec(clock-consumer@3, 1, "name2", &args);
4991 * Return: 0 upon successfully parsing the clock specifier. Otherwise, -ENOENT
4992 * if @name is NULL or -EINVAL if @name is non-NULL and it can't be found in
4993 * the "clock-names" property of @np.
4995 static int of_parse_clkspec(const struct device_node *np, int index,
4996 const char *name, struct of_phandle_args *out_args)
5000 /* Walk up the tree of devices looking for a clock property that matches */
5003 * For named clocks, first look up the name in the
5004 * "clock-names" property. If it cannot be found, then index
5005 * will be an error code and of_parse_phandle_with_args() will
5009 index = of_property_match_string(np, "clock-names", name);
5010 ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells",
5014 if (name && index >= 0)
5018 * No matching clock found on this node. If the parent node
5019 * has a "clock-ranges" property, then we can try one of its
5023 if (np && !of_get_property(np, "clock-ranges", NULL))
5031 static struct clk_hw *
5032 __of_clk_get_hw_from_provider(struct of_clk_provider *provider,
5033 struct of_phandle_args *clkspec)
5037 if (provider->get_hw)
5038 return provider->get_hw(clkspec, provider->data);
5040 clk = provider->get(clkspec, provider->data);
5042 return ERR_CAST(clk);
5043 return __clk_get_hw(clk);
5046 static struct clk_hw *
5047 of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
5049 struct of_clk_provider *provider;
5050 struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER);
5053 return ERR_PTR(-EINVAL);
5055 mutex_lock(&of_clk_mutex);
5056 list_for_each_entry(provider, &of_clk_providers, link) {
5057 if (provider->node == clkspec->np) {
5058 hw = __of_clk_get_hw_from_provider(provider, clkspec);
5063 mutex_unlock(&of_clk_mutex);
5069 * of_clk_get_from_provider() - Lookup a clock from a clock provider
5070 * @clkspec: pointer to a clock specifier data structure
5072 * This function looks up a struct clk from the registered list of clock
5073 * providers, an input is a clock specifier data structure as returned
5074 * from the of_parse_phandle_with_args() function call.
5076 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
5078 struct clk_hw *hw = of_clk_get_hw_from_clkspec(clkspec);
5080 return clk_hw_create_clk(NULL, hw, NULL, __func__);
5082 EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
5084 struct clk_hw *of_clk_get_hw(struct device_node *np, int index,
5089 struct of_phandle_args clkspec;
5091 ret = of_parse_clkspec(np, index, con_id, &clkspec);
5093 return ERR_PTR(ret);
5095 hw = of_clk_get_hw_from_clkspec(&clkspec);
5096 of_node_put(clkspec.np);
5101 static struct clk *__of_clk_get(struct device_node *np,
5102 int index, const char *dev_id,
5105 struct clk_hw *hw = of_clk_get_hw(np, index, con_id);
5107 return clk_hw_create_clk(NULL, hw, dev_id, con_id);
5110 struct clk *of_clk_get(struct device_node *np, int index)
5112 return __of_clk_get(np, index, np->full_name, NULL);
5114 EXPORT_SYMBOL(of_clk_get);
5117 * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
5118 * @np: pointer to clock consumer node
5119 * @name: name of consumer's clock input, or NULL for the first clock reference
5121 * This function parses the clocks and clock-names properties,
5122 * and uses them to look up the struct clk from the registered list of clock
5125 struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
5128 return ERR_PTR(-ENOENT);
5130 return __of_clk_get(np, 0, np->full_name, name);
5132 EXPORT_SYMBOL(of_clk_get_by_name);
5135 * of_clk_get_parent_count() - Count the number of clocks a device node has
5136 * @np: device node to count
5138 * Returns: The number of clocks that are possible parents of this node
5140 unsigned int of_clk_get_parent_count(const struct device_node *np)
5144 count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
5150 EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
5152 const char *of_clk_get_parent_name(const struct device_node *np, int index)
5154 struct of_phandle_args clkspec;
5155 struct property *prop;
5156 const char *clk_name;
5163 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
5168 index = clkspec.args_count ? clkspec.args[0] : 0;
5171 /* if there is an indices property, use it to transfer the index
5172 * specified into an array offset for the clock-output-names property.
5174 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
5181 /* We went off the end of 'clock-indices' without finding it */
5185 if (of_property_read_string_index(clkspec.np, "clock-output-names",
5189 * Best effort to get the name if the clock has been
5190 * registered with the framework. If the clock isn't
5191 * registered, we return the node name as the name of
5192 * the clock as long as #clock-cells = 0.
5194 clk = of_clk_get_from_provider(&clkspec);
5196 if (clkspec.args_count == 0)
5197 clk_name = clkspec.np->name;
5201 clk_name = __clk_get_name(clk);
5207 of_node_put(clkspec.np);
5210 EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
5213 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
5215 * @np: Device node pointer associated with clock provider
5216 * @parents: pointer to char array that hold the parents' names
5217 * @size: size of the @parents array
5219 * Return: number of parents for the clock node.
5221 int of_clk_parent_fill(struct device_node *np, const char **parents,
5226 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
5231 EXPORT_SYMBOL_GPL(of_clk_parent_fill);
5233 struct clock_provider {
5234 void (*clk_init_cb)(struct device_node *);
5235 struct device_node *np;
5236 struct list_head node;
5240 * This function looks for a parent clock. If there is one, then it
5241 * checks that the provider for this parent clock was initialized, in
5242 * this case the parent clock will be ready.
5244 static int parent_ready(struct device_node *np)
5249 struct clk *clk = of_clk_get(np, i);
5251 /* this parent is ready we can check the next one */
5258 /* at least one parent is not ready, we exit now */
5259 if (PTR_ERR(clk) == -EPROBE_DEFER)
5263 * Here we make assumption that the device tree is
5264 * written correctly. So an error means that there is
5265 * no more parent. As we didn't exit yet, then the
5266 * previous parent are ready. If there is no clock
5267 * parent, no need to wait for them, then we can
5268 * consider their absence as being ready
5275 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
5276 * @np: Device node pointer associated with clock provider
5277 * @index: clock index
5278 * @flags: pointer to top-level framework flags
5280 * Detects if the clock-critical property exists and, if so, sets the
5281 * corresponding CLK_IS_CRITICAL flag.
5283 * Do not use this function. It exists only for legacy Device Tree
5284 * bindings, such as the one-clock-per-node style that are outdated.
5285 * Those bindings typically put all clock data into .dts and the Linux
5286 * driver has no clock data, thus making it impossible to set this flag
5287 * correctly from the driver. Only those drivers may call
5288 * of_clk_detect_critical from their setup functions.
5290 * Return: error code or zero on success
5292 int of_clk_detect_critical(struct device_node *np, int index,
5293 unsigned long *flags)
5295 struct property *prop;
5302 of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
5304 *flags |= CLK_IS_CRITICAL;
5310 * of_clk_init() - Scan and init clock providers from the DT
5311 * @matches: array of compatible values and init functions for providers.
5313 * This function scans the device tree for matching clock providers
5314 * and calls their initialization functions. It also does it by trying
5315 * to follow the dependencies.
5317 void __init of_clk_init(const struct of_device_id *matches)
5319 const struct of_device_id *match;
5320 struct device_node *np;
5321 struct clock_provider *clk_provider, *next;
5324 LIST_HEAD(clk_provider_list);
5327 matches = &__clk_of_table;
5329 /* First prepare the list of the clocks providers */
5330 for_each_matching_node_and_match(np, matches, &match) {
5331 struct clock_provider *parent;
5333 if (!of_device_is_available(np))
5336 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
5338 list_for_each_entry_safe(clk_provider, next,
5339 &clk_provider_list, node) {
5340 list_del(&clk_provider->node);
5341 of_node_put(clk_provider->np);
5342 kfree(clk_provider);
5348 parent->clk_init_cb = match->data;
5349 parent->np = of_node_get(np);
5350 list_add_tail(&parent->node, &clk_provider_list);
5353 while (!list_empty(&clk_provider_list)) {
5354 is_init_done = false;
5355 list_for_each_entry_safe(clk_provider, next,
5356 &clk_provider_list, node) {
5357 if (force || parent_ready(clk_provider->np)) {
5359 /* Don't populate platform devices */
5360 of_node_set_flag(clk_provider->np,
5363 clk_provider->clk_init_cb(clk_provider->np);
5364 of_clk_set_defaults(clk_provider->np, true);
5366 list_del(&clk_provider->node);
5367 of_node_put(clk_provider->np);
5368 kfree(clk_provider);
5369 is_init_done = true;
5374 * We didn't manage to initialize any of the
5375 * remaining providers during the last loop, so now we
5376 * initialize all the remaining ones unconditionally
5377 * in case the clock parent was not mandatory