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 /* List of registered clks that use runtime PM */
41 static HLIST_HEAD(clk_rpm_list);
42 static DEFINE_MUTEX(clk_rpm_list_lock);
44 static const struct hlist_head *all_lists[] = {
50 /*** private data structures ***/
52 struct clk_parent_map {
53 const struct clk_hw *hw;
54 struct clk_core *core;
62 const struct clk_ops *ops;
66 struct hlist_node rpm_node;
67 struct device_node *of_node;
68 struct clk_core *parent;
69 struct clk_parent_map *parents;
73 unsigned long req_rate;
74 unsigned long new_rate;
75 struct clk_core *new_parent;
76 struct clk_core *new_child;
80 unsigned int enable_count;
81 unsigned int prepare_count;
82 unsigned int protect_count;
83 unsigned long min_rate;
84 unsigned long max_rate;
85 unsigned long accuracy;
88 struct hlist_head children;
89 struct hlist_node child_node;
90 struct hlist_head clks;
91 unsigned int notifier_count;
92 #ifdef CONFIG_DEBUG_FS
93 struct dentry *dentry;
94 struct hlist_node debug_node;
99 #define CREATE_TRACE_POINTS
100 #include <trace/events/clk.h>
103 struct clk_core *core;
107 unsigned long min_rate;
108 unsigned long max_rate;
109 unsigned int exclusive_count;
110 struct hlist_node clks_node;
114 static int clk_pm_runtime_get(struct clk_core *core)
116 if (!core->rpm_enabled)
119 return pm_runtime_resume_and_get(core->dev);
122 static void clk_pm_runtime_put(struct clk_core *core)
124 if (!core->rpm_enabled)
127 pm_runtime_put_sync(core->dev);
131 * clk_pm_runtime_get_all() - Runtime "get" all clk provider devices
133 * Call clk_pm_runtime_get() on all runtime PM enabled clks in the clk tree so
134 * that disabling unused clks avoids a deadlock where a device is runtime PM
135 * resuming/suspending and the runtime PM callback is trying to grab the
136 * prepare_lock for something like clk_prepare_enable() while
137 * clk_disable_unused_subtree() holds the prepare_lock and is trying to runtime
138 * PM resume/suspend the device as well.
140 * Context: Acquires the 'clk_rpm_list_lock' and returns with the lock held on
141 * success. Otherwise the lock is released on failure.
143 * Return: 0 on success, negative errno otherwise.
145 static int clk_pm_runtime_get_all(void)
148 struct clk_core *core, *failed;
151 * Grab the list lock to prevent any new clks from being registered
152 * or unregistered until clk_pm_runtime_put_all().
154 mutex_lock(&clk_rpm_list_lock);
157 * Runtime PM "get" all the devices that are needed for the clks
158 * currently registered. Do this without holding the prepare_lock, to
159 * avoid the deadlock.
161 hlist_for_each_entry(core, &clk_rpm_list, rpm_node) {
162 ret = clk_pm_runtime_get(core);
165 pr_err("clk: Failed to runtime PM get '%s' for clk '%s'\n",
166 dev_name(failed->dev), failed->name);
174 hlist_for_each_entry(core, &clk_rpm_list, rpm_node) {
178 clk_pm_runtime_put(core);
180 mutex_unlock(&clk_rpm_list_lock);
186 * clk_pm_runtime_put_all() - Runtime "put" all clk provider devices
188 * Put the runtime PM references taken in clk_pm_runtime_get_all() and release
189 * the 'clk_rpm_list_lock'.
191 static void clk_pm_runtime_put_all(void)
193 struct clk_core *core;
195 hlist_for_each_entry(core, &clk_rpm_list, rpm_node)
196 clk_pm_runtime_put(core);
197 mutex_unlock(&clk_rpm_list_lock);
200 static void clk_pm_runtime_init(struct clk_core *core)
202 struct device *dev = core->dev;
204 if (dev && pm_runtime_enabled(dev)) {
205 core->rpm_enabled = true;
207 mutex_lock(&clk_rpm_list_lock);
208 hlist_add_head(&core->rpm_node, &clk_rpm_list);
209 mutex_unlock(&clk_rpm_list_lock);
214 static void clk_prepare_lock(void)
216 if (!mutex_trylock(&prepare_lock)) {
217 if (prepare_owner == current) {
221 mutex_lock(&prepare_lock);
223 WARN_ON_ONCE(prepare_owner != NULL);
224 WARN_ON_ONCE(prepare_refcnt != 0);
225 prepare_owner = current;
229 static void clk_prepare_unlock(void)
231 WARN_ON_ONCE(prepare_owner != current);
232 WARN_ON_ONCE(prepare_refcnt == 0);
234 if (--prepare_refcnt)
236 prepare_owner = NULL;
237 mutex_unlock(&prepare_lock);
240 static unsigned long clk_enable_lock(void)
241 __acquires(enable_lock)
246 * On UP systems, spin_trylock_irqsave() always returns true, even if
247 * we already hold the lock. So, in that case, we rely only on
248 * reference counting.
250 if (!IS_ENABLED(CONFIG_SMP) ||
251 !spin_trylock_irqsave(&enable_lock, flags)) {
252 if (enable_owner == current) {
254 __acquire(enable_lock);
255 if (!IS_ENABLED(CONFIG_SMP))
256 local_save_flags(flags);
259 spin_lock_irqsave(&enable_lock, flags);
261 WARN_ON_ONCE(enable_owner != NULL);
262 WARN_ON_ONCE(enable_refcnt != 0);
263 enable_owner = current;
268 static void clk_enable_unlock(unsigned long flags)
269 __releases(enable_lock)
271 WARN_ON_ONCE(enable_owner != current);
272 WARN_ON_ONCE(enable_refcnt == 0);
274 if (--enable_refcnt) {
275 __release(enable_lock);
279 spin_unlock_irqrestore(&enable_lock, flags);
282 static bool clk_core_rate_is_protected(struct clk_core *core)
284 return core->protect_count;
287 static bool clk_core_is_prepared(struct clk_core *core)
292 * .is_prepared is optional for clocks that can prepare
293 * fall back to software usage counter if it is missing
295 if (!core->ops->is_prepared)
296 return core->prepare_count;
298 if (!clk_pm_runtime_get(core)) {
299 ret = core->ops->is_prepared(core->hw);
300 clk_pm_runtime_put(core);
306 static bool clk_core_is_enabled(struct clk_core *core)
311 * .is_enabled is only mandatory for clocks that gate
312 * fall back to software usage counter if .is_enabled is missing
314 if (!core->ops->is_enabled)
315 return core->enable_count;
318 * Check if clock controller's device is runtime active before
319 * calling .is_enabled callback. If not, assume that clock is
320 * disabled, because we might be called from atomic context, from
321 * which pm_runtime_get() is not allowed.
322 * This function is called mainly from clk_disable_unused_subtree,
323 * which ensures proper runtime pm activation of controller before
324 * taking enable spinlock, but the below check is needed if one tries
325 * to call it from other places.
327 if (core->rpm_enabled) {
328 pm_runtime_get_noresume(core->dev);
329 if (!pm_runtime_active(core->dev)) {
336 * This could be called with the enable lock held, or from atomic
337 * context. If the parent isn't enabled already, we can't do
338 * anything here. We can also assume this clock isn't enabled.
340 if ((core->flags & CLK_OPS_PARENT_ENABLE) && core->parent)
341 if (!clk_core_is_enabled(core->parent)) {
346 ret = core->ops->is_enabled(core->hw);
348 if (core->rpm_enabled)
349 pm_runtime_put(core->dev);
354 /*** helper functions ***/
356 const char *__clk_get_name(const struct clk *clk)
358 return !clk ? NULL : clk->core->name;
360 EXPORT_SYMBOL_GPL(__clk_get_name);
362 const char *clk_hw_get_name(const struct clk_hw *hw)
364 return hw->core->name;
366 EXPORT_SYMBOL_GPL(clk_hw_get_name);
368 struct clk_hw *__clk_get_hw(struct clk *clk)
370 return !clk ? NULL : clk->core->hw;
372 EXPORT_SYMBOL_GPL(__clk_get_hw);
374 unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
376 return hw->core->num_parents;
378 EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
380 struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
382 return hw->core->parent ? hw->core->parent->hw : NULL;
384 EXPORT_SYMBOL_GPL(clk_hw_get_parent);
386 static struct clk_core *__clk_lookup_subtree(const char *name,
387 struct clk_core *core)
389 struct clk_core *child;
390 struct clk_core *ret;
392 if (!strcmp(core->name, name))
395 hlist_for_each_entry(child, &core->children, child_node) {
396 ret = __clk_lookup_subtree(name, child);
404 static struct clk_core *clk_core_lookup(const char *name)
406 struct clk_core *root_clk;
407 struct clk_core *ret;
412 /* search the 'proper' clk tree first */
413 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
414 ret = __clk_lookup_subtree(name, root_clk);
419 /* if not found, then search the orphan tree */
420 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
421 ret = __clk_lookup_subtree(name, root_clk);
430 static int of_parse_clkspec(const struct device_node *np, int index,
431 const char *name, struct of_phandle_args *out_args);
432 static struct clk_hw *
433 of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec);
435 static inline int of_parse_clkspec(const struct device_node *np, int index,
437 struct of_phandle_args *out_args)
441 static inline struct clk_hw *
442 of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
444 return ERR_PTR(-ENOENT);
449 * clk_core_get - Find the clk_core parent of a clk
450 * @core: clk to find parent of
451 * @p_index: parent index to search for
453 * This is the preferred method for clk providers to find the parent of a
454 * clk when that parent is external to the clk controller. The parent_names
455 * array is indexed and treated as a local name matching a string in the device
456 * node's 'clock-names' property or as the 'con_id' matching the device's
457 * dev_name() in a clk_lookup. This allows clk providers to use their own
458 * namespace instead of looking for a globally unique parent string.
460 * For example the following DT snippet would allow a clock registered by the
461 * clock-controller@c001 that has a clk_init_data::parent_data array
462 * with 'xtal' in the 'name' member to find the clock provided by the
463 * clock-controller@f00abcd without needing to get the globally unique name of
466 * parent: clock-controller@f00abcd {
467 * reg = <0xf00abcd 0xabcd>;
468 * #clock-cells = <0>;
471 * clock-controller@c001 {
472 * reg = <0xc001 0xf00d>;
473 * clocks = <&parent>;
474 * clock-names = "xtal";
475 * #clock-cells = <1>;
478 * Returns: -ENOENT when the provider can't be found or the clk doesn't
479 * exist in the provider or the name can't be found in the DT node or
480 * in a clkdev lookup. NULL when the provider knows about the clk but it
481 * isn't provided on this system.
482 * A valid clk_core pointer when the clk can be found in the provider.
484 static struct clk_core *clk_core_get(struct clk_core *core, u8 p_index)
486 const char *name = core->parents[p_index].fw_name;
487 int index = core->parents[p_index].index;
488 struct clk_hw *hw = ERR_PTR(-ENOENT);
489 struct device *dev = core->dev;
490 const char *dev_id = dev ? dev_name(dev) : NULL;
491 struct device_node *np = core->of_node;
492 struct of_phandle_args clkspec;
494 if (np && (name || index >= 0) &&
495 !of_parse_clkspec(np, index, name, &clkspec)) {
496 hw = of_clk_get_hw_from_clkspec(&clkspec);
497 of_node_put(clkspec.np);
500 * If the DT search above couldn't find the provider fallback to
501 * looking up via clkdev based clk_lookups.
503 hw = clk_find_hw(dev_id, name);
515 static void clk_core_fill_parent_index(struct clk_core *core, u8 index)
517 struct clk_parent_map *entry = &core->parents[index];
518 struct clk_core *parent;
521 parent = entry->hw->core;
523 parent = clk_core_get(core, index);
524 if (PTR_ERR(parent) == -ENOENT && entry->name)
525 parent = clk_core_lookup(entry->name);
529 * We have a direct reference but it isn't registered yet?
530 * Orphan it and let clk_reparent() update the orphan status
531 * when the parent is registered.
534 parent = ERR_PTR(-EPROBE_DEFER);
536 /* Only cache it if it's not an error */
538 entry->core = parent;
541 static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
544 if (!core || index >= core->num_parents || !core->parents)
547 if (!core->parents[index].core)
548 clk_core_fill_parent_index(core, index);
550 return core->parents[index].core;
554 clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
556 struct clk_core *parent;
558 parent = clk_core_get_parent_by_index(hw->core, index);
560 return !parent ? NULL : parent->hw;
562 EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
564 unsigned int __clk_get_enable_count(struct clk *clk)
566 return !clk ? 0 : clk->core->enable_count;
569 static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
574 if (!core->num_parents || core->parent)
578 * Clk must have a parent because num_parents > 0 but the parent isn't
579 * known yet. Best to return 0 as the rate of this clk until we can
580 * properly recalc the rate based on the parent's rate.
585 unsigned long clk_hw_get_rate(const struct clk_hw *hw)
587 return clk_core_get_rate_nolock(hw->core);
589 EXPORT_SYMBOL_GPL(clk_hw_get_rate);
591 static unsigned long clk_core_get_accuracy_no_lock(struct clk_core *core)
596 return core->accuracy;
599 unsigned long clk_hw_get_flags(const struct clk_hw *hw)
601 return hw->core->flags;
603 EXPORT_SYMBOL_GPL(clk_hw_get_flags);
605 bool clk_hw_is_prepared(const struct clk_hw *hw)
607 return clk_core_is_prepared(hw->core);
609 EXPORT_SYMBOL_GPL(clk_hw_is_prepared);
611 bool clk_hw_rate_is_protected(const struct clk_hw *hw)
613 return clk_core_rate_is_protected(hw->core);
615 EXPORT_SYMBOL_GPL(clk_hw_rate_is_protected);
617 bool clk_hw_is_enabled(const struct clk_hw *hw)
619 return clk_core_is_enabled(hw->core);
621 EXPORT_SYMBOL_GPL(clk_hw_is_enabled);
623 bool __clk_is_enabled(struct clk *clk)
628 return clk_core_is_enabled(clk->core);
630 EXPORT_SYMBOL_GPL(__clk_is_enabled);
632 static bool mux_is_better_rate(unsigned long rate, unsigned long now,
633 unsigned long best, unsigned long flags)
635 if (flags & CLK_MUX_ROUND_CLOSEST)
636 return abs(now - rate) < abs(best - rate);
638 return now <= rate && now > best;
641 static void clk_core_init_rate_req(struct clk_core * const core,
642 struct clk_rate_request *req,
645 static int clk_core_round_rate_nolock(struct clk_core *core,
646 struct clk_rate_request *req);
648 static bool clk_core_has_parent(struct clk_core *core, const struct clk_core *parent)
650 struct clk_core *tmp;
653 /* Optimize for the case where the parent is already the parent. */
654 if (core->parent == parent)
657 for (i = 0; i < core->num_parents; i++) {
658 tmp = clk_core_get_parent_by_index(core, i);
670 clk_core_forward_rate_req(struct clk_core *core,
671 const struct clk_rate_request *old_req,
672 struct clk_core *parent,
673 struct clk_rate_request *req,
674 unsigned long parent_rate)
676 if (WARN_ON(!clk_core_has_parent(core, parent)))
679 clk_core_init_rate_req(parent, req, parent_rate);
681 if (req->min_rate < old_req->min_rate)
682 req->min_rate = old_req->min_rate;
684 if (req->max_rate > old_req->max_rate)
685 req->max_rate = old_req->max_rate;
689 clk_core_determine_rate_no_reparent(struct clk_hw *hw,
690 struct clk_rate_request *req)
692 struct clk_core *core = hw->core;
693 struct clk_core *parent = core->parent;
697 if (core->flags & CLK_SET_RATE_PARENT) {
698 struct clk_rate_request parent_req;
705 clk_core_forward_rate_req(core, req, parent, &parent_req,
708 trace_clk_rate_request_start(&parent_req);
710 ret = clk_core_round_rate_nolock(parent, &parent_req);
714 trace_clk_rate_request_done(&parent_req);
716 best = parent_req.rate;
718 best = clk_core_get_rate_nolock(parent);
720 best = clk_core_get_rate_nolock(core);
723 req->best_parent_rate = best;
729 int clk_mux_determine_rate_flags(struct clk_hw *hw,
730 struct clk_rate_request *req,
733 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
734 int i, num_parents, ret;
735 unsigned long best = 0;
737 /* if NO_REPARENT flag set, pass through to current parent */
738 if (core->flags & CLK_SET_RATE_NO_REPARENT)
739 return clk_core_determine_rate_no_reparent(hw, req);
741 /* find the parent that can provide the fastest rate <= rate */
742 num_parents = core->num_parents;
743 for (i = 0; i < num_parents; i++) {
744 unsigned long parent_rate;
746 parent = clk_core_get_parent_by_index(core, i);
750 if (core->flags & CLK_SET_RATE_PARENT) {
751 struct clk_rate_request parent_req;
753 clk_core_forward_rate_req(core, req, parent, &parent_req, req->rate);
755 trace_clk_rate_request_start(&parent_req);
757 ret = clk_core_round_rate_nolock(parent, &parent_req);
761 trace_clk_rate_request_done(&parent_req);
763 parent_rate = parent_req.rate;
765 parent_rate = clk_core_get_rate_nolock(parent);
768 if (mux_is_better_rate(req->rate, parent_rate,
770 best_parent = parent;
778 req->best_parent_hw = best_parent->hw;
779 req->best_parent_rate = best;
784 EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);
786 struct clk *__clk_lookup(const char *name)
788 struct clk_core *core = clk_core_lookup(name);
790 return !core ? NULL : core->hw->clk;
793 static void clk_core_get_boundaries(struct clk_core *core,
794 unsigned long *min_rate,
795 unsigned long *max_rate)
797 struct clk *clk_user;
799 lockdep_assert_held(&prepare_lock);
801 *min_rate = core->min_rate;
802 *max_rate = core->max_rate;
804 hlist_for_each_entry(clk_user, &core->clks, clks_node)
805 *min_rate = max(*min_rate, clk_user->min_rate);
807 hlist_for_each_entry(clk_user, &core->clks, clks_node)
808 *max_rate = min(*max_rate, clk_user->max_rate);
812 * clk_hw_get_rate_range() - returns the clock rate range for a hw clk
813 * @hw: the hw clk we want to get the range from
814 * @min_rate: pointer to the variable that will hold the minimum
815 * @max_rate: pointer to the variable that will hold the maximum
817 * Fills the @min_rate and @max_rate variables with the minimum and
818 * maximum that clock can reach.
820 void clk_hw_get_rate_range(struct clk_hw *hw, unsigned long *min_rate,
821 unsigned long *max_rate)
823 clk_core_get_boundaries(hw->core, min_rate, max_rate);
825 EXPORT_SYMBOL_GPL(clk_hw_get_rate_range);
827 static bool clk_core_check_boundaries(struct clk_core *core,
828 unsigned long min_rate,
829 unsigned long max_rate)
833 lockdep_assert_held(&prepare_lock);
835 if (min_rate > core->max_rate || max_rate < core->min_rate)
838 hlist_for_each_entry(user, &core->clks, clks_node)
839 if (min_rate > user->max_rate || max_rate < user->min_rate)
845 void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
846 unsigned long max_rate)
848 hw->core->min_rate = min_rate;
849 hw->core->max_rate = max_rate;
851 EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
854 * __clk_mux_determine_rate - clk_ops::determine_rate implementation for a mux type clk
855 * @hw: mux type clk to determine rate on
856 * @req: rate request, also used to return preferred parent and frequencies
858 * Helper for finding best parent to provide a given frequency. This can be used
859 * directly as a determine_rate callback (e.g. for a mux), or from a more
860 * complex clock that may combine a mux with other operations.
862 * Returns: 0 on success, -EERROR value on error
864 int __clk_mux_determine_rate(struct clk_hw *hw,
865 struct clk_rate_request *req)
867 return clk_mux_determine_rate_flags(hw, req, 0);
869 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
871 int __clk_mux_determine_rate_closest(struct clk_hw *hw,
872 struct clk_rate_request *req)
874 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
876 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
879 * clk_hw_determine_rate_no_reparent - clk_ops::determine_rate implementation for a clk that doesn't reparent
880 * @hw: mux type clk to determine rate on
881 * @req: rate request, also used to return preferred frequency
883 * Helper for finding best parent rate to provide a given frequency.
884 * This can be used directly as a determine_rate callback (e.g. for a
885 * mux), or from a more complex clock that may combine a mux with other
888 * Returns: 0 on success, -EERROR value on error
890 int clk_hw_determine_rate_no_reparent(struct clk_hw *hw,
891 struct clk_rate_request *req)
893 return clk_core_determine_rate_no_reparent(hw, req);
895 EXPORT_SYMBOL_GPL(clk_hw_determine_rate_no_reparent);
899 static void clk_core_rate_unprotect(struct clk_core *core)
901 lockdep_assert_held(&prepare_lock);
906 if (WARN(core->protect_count == 0,
907 "%s already unprotected\n", core->name))
910 if (--core->protect_count > 0)
913 clk_core_rate_unprotect(core->parent);
916 static int clk_core_rate_nuke_protect(struct clk_core *core)
920 lockdep_assert_held(&prepare_lock);
925 if (core->protect_count == 0)
928 ret = core->protect_count;
929 core->protect_count = 1;
930 clk_core_rate_unprotect(core);
936 * clk_rate_exclusive_put - release exclusivity over clock rate control
937 * @clk: the clk over which the exclusivity is released
939 * clk_rate_exclusive_put() completes a critical section during which a clock
940 * consumer cannot tolerate any other consumer making any operation on the
941 * clock which could result in a rate change or rate glitch. Exclusive clocks
942 * cannot have their rate changed, either directly or indirectly due to changes
943 * further up the parent chain of clocks. As a result, clocks up parent chain
944 * also get under exclusive control of the calling consumer.
946 * If exlusivity is claimed more than once on clock, even by the same consumer,
947 * the rate effectively gets locked as exclusivity can't be preempted.
949 * Calls to clk_rate_exclusive_put() must be balanced with calls to
950 * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
953 void clk_rate_exclusive_put(struct clk *clk)
961 * if there is something wrong with this consumer protect count, stop
962 * here before messing with the provider
964 if (WARN_ON(clk->exclusive_count <= 0))
967 clk_core_rate_unprotect(clk->core);
968 clk->exclusive_count--;
970 clk_prepare_unlock();
972 EXPORT_SYMBOL_GPL(clk_rate_exclusive_put);
974 static void clk_core_rate_protect(struct clk_core *core)
976 lockdep_assert_held(&prepare_lock);
981 if (core->protect_count == 0)
982 clk_core_rate_protect(core->parent);
984 core->protect_count++;
987 static void clk_core_rate_restore_protect(struct clk_core *core, int count)
989 lockdep_assert_held(&prepare_lock);
997 clk_core_rate_protect(core);
998 core->protect_count = count;
1002 * clk_rate_exclusive_get - get exclusivity over the clk rate control
1003 * @clk: the clk over which the exclusity of rate control is requested
1005 * clk_rate_exclusive_get() begins a critical section during which a clock
1006 * consumer cannot tolerate any other consumer making any operation on the
1007 * clock which could result in a rate change or rate glitch. Exclusive clocks
1008 * cannot have their rate changed, either directly or indirectly due to changes
1009 * further up the parent chain of clocks. As a result, clocks up parent chain
1010 * also get under exclusive control of the calling consumer.
1012 * If exlusivity is claimed more than once on clock, even by the same consumer,
1013 * the rate effectively gets locked as exclusivity can't be preempted.
1015 * Calls to clk_rate_exclusive_get() should be balanced with calls to
1016 * clk_rate_exclusive_put(). Calls to this function may sleep.
1017 * Returns 0 on success, -EERROR otherwise
1019 int clk_rate_exclusive_get(struct clk *clk)
1025 clk_core_rate_protect(clk->core);
1026 clk->exclusive_count++;
1027 clk_prepare_unlock();
1031 EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
1033 static void clk_core_unprepare(struct clk_core *core)
1035 lockdep_assert_held(&prepare_lock);
1040 if (WARN(core->prepare_count == 0,
1041 "%s already unprepared\n", core->name))
1044 if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL,
1045 "Unpreparing critical %s\n", core->name))
1048 if (core->flags & CLK_SET_RATE_GATE)
1049 clk_core_rate_unprotect(core);
1051 if (--core->prepare_count > 0)
1054 WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);
1056 trace_clk_unprepare(core);
1058 if (core->ops->unprepare)
1059 core->ops->unprepare(core->hw);
1061 trace_clk_unprepare_complete(core);
1062 clk_core_unprepare(core->parent);
1063 clk_pm_runtime_put(core);
1066 static void clk_core_unprepare_lock(struct clk_core *core)
1069 clk_core_unprepare(core);
1070 clk_prepare_unlock();
1074 * clk_unprepare - undo preparation of a clock source
1075 * @clk: the clk being unprepared
1077 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
1078 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
1079 * if the operation may sleep. One example is a clk which is accessed over
1080 * I2c. In the complex case a clk gate operation may require a fast and a slow
1081 * part. It is this reason that clk_unprepare and clk_disable are not mutually
1082 * exclusive. In fact clk_disable must be called before clk_unprepare.
1084 void clk_unprepare(struct clk *clk)
1086 if (IS_ERR_OR_NULL(clk))
1089 clk_core_unprepare_lock(clk->core);
1091 EXPORT_SYMBOL_GPL(clk_unprepare);
1093 static int clk_core_prepare(struct clk_core *core)
1097 lockdep_assert_held(&prepare_lock);
1102 if (core->prepare_count == 0) {
1103 ret = clk_pm_runtime_get(core);
1107 ret = clk_core_prepare(core->parent);
1111 trace_clk_prepare(core);
1113 if (core->ops->prepare)
1114 ret = core->ops->prepare(core->hw);
1116 trace_clk_prepare_complete(core);
1122 core->prepare_count++;
1125 * CLK_SET_RATE_GATE is a special case of clock protection
1126 * Instead of a consumer claiming exclusive rate control, it is
1127 * actually the provider which prevents any consumer from making any
1128 * operation which could result in a rate change or rate glitch while
1129 * the clock is prepared.
1131 if (core->flags & CLK_SET_RATE_GATE)
1132 clk_core_rate_protect(core);
1136 clk_core_unprepare(core->parent);
1138 clk_pm_runtime_put(core);
1142 static int clk_core_prepare_lock(struct clk_core *core)
1147 ret = clk_core_prepare(core);
1148 clk_prepare_unlock();
1154 * clk_prepare - prepare a clock source
1155 * @clk: the clk being prepared
1157 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
1158 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
1159 * operation may sleep. One example is a clk which is accessed over I2c. In
1160 * the complex case a clk ungate operation may require a fast and a slow part.
1161 * It is this reason that clk_prepare and clk_enable are not mutually
1162 * exclusive. In fact clk_prepare must be called before clk_enable.
1163 * Returns 0 on success, -EERROR otherwise.
1165 int clk_prepare(struct clk *clk)
1170 return clk_core_prepare_lock(clk->core);
1172 EXPORT_SYMBOL_GPL(clk_prepare);
1174 static void clk_core_disable(struct clk_core *core)
1176 lockdep_assert_held(&enable_lock);
1181 if (WARN(core->enable_count == 0, "%s already disabled\n", core->name))
1184 if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL,
1185 "Disabling critical %s\n", core->name))
1188 if (--core->enable_count > 0)
1191 trace_clk_disable(core);
1193 if (core->ops->disable)
1194 core->ops->disable(core->hw);
1196 trace_clk_disable_complete(core);
1198 clk_core_disable(core->parent);
1201 static void clk_core_disable_lock(struct clk_core *core)
1203 unsigned long flags;
1205 flags = clk_enable_lock();
1206 clk_core_disable(core);
1207 clk_enable_unlock(flags);
1211 * clk_disable - gate a clock
1212 * @clk: the clk being gated
1214 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
1215 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
1216 * clk if the operation is fast and will never sleep. One example is a
1217 * SoC-internal clk which is controlled via simple register writes. In the
1218 * complex case a clk gate operation may require a fast and a slow part. It is
1219 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
1220 * In fact clk_disable must be called before clk_unprepare.
1222 void clk_disable(struct clk *clk)
1224 if (IS_ERR_OR_NULL(clk))
1227 clk_core_disable_lock(clk->core);
1229 EXPORT_SYMBOL_GPL(clk_disable);
1231 static int clk_core_enable(struct clk_core *core)
1235 lockdep_assert_held(&enable_lock);
1240 if (WARN(core->prepare_count == 0,
1241 "Enabling unprepared %s\n", core->name))
1244 if (core->enable_count == 0) {
1245 ret = clk_core_enable(core->parent);
1250 trace_clk_enable(core);
1252 if (core->ops->enable)
1253 ret = core->ops->enable(core->hw);
1255 trace_clk_enable_complete(core);
1258 clk_core_disable(core->parent);
1263 core->enable_count++;
1267 static int clk_core_enable_lock(struct clk_core *core)
1269 unsigned long flags;
1272 flags = clk_enable_lock();
1273 ret = clk_core_enable(core);
1274 clk_enable_unlock(flags);
1280 * clk_gate_restore_context - restore context for poweroff
1281 * @hw: the clk_hw pointer of clock whose state is to be restored
1283 * The clock gate restore context function enables or disables
1284 * the gate clocks based on the enable_count. This is done in cases
1285 * where the clock context is lost and based on the enable_count
1286 * the clock either needs to be enabled/disabled. This
1287 * helps restore the state of gate clocks.
1289 void clk_gate_restore_context(struct clk_hw *hw)
1291 struct clk_core *core = hw->core;
1293 if (core->enable_count)
1294 core->ops->enable(hw);
1296 core->ops->disable(hw);
1298 EXPORT_SYMBOL_GPL(clk_gate_restore_context);
1300 static int clk_core_save_context(struct clk_core *core)
1302 struct clk_core *child;
1305 hlist_for_each_entry(child, &core->children, child_node) {
1306 ret = clk_core_save_context(child);
1311 if (core->ops && core->ops->save_context)
1312 ret = core->ops->save_context(core->hw);
1317 static void clk_core_restore_context(struct clk_core *core)
1319 struct clk_core *child;
1321 if (core->ops && core->ops->restore_context)
1322 core->ops->restore_context(core->hw);
1324 hlist_for_each_entry(child, &core->children, child_node)
1325 clk_core_restore_context(child);
1329 * clk_save_context - save clock context for poweroff
1331 * Saves the context of the clock register for powerstates in which the
1332 * contents of the registers will be lost. Occurs deep within the suspend
1333 * code. Returns 0 on success.
1335 int clk_save_context(void)
1337 struct clk_core *clk;
1340 hlist_for_each_entry(clk, &clk_root_list, child_node) {
1341 ret = clk_core_save_context(clk);
1346 hlist_for_each_entry(clk, &clk_orphan_list, child_node) {
1347 ret = clk_core_save_context(clk);
1354 EXPORT_SYMBOL_GPL(clk_save_context);
1357 * clk_restore_context - restore clock context after poweroff
1359 * Restore the saved clock context upon resume.
1362 void clk_restore_context(void)
1364 struct clk_core *core;
1366 hlist_for_each_entry(core, &clk_root_list, child_node)
1367 clk_core_restore_context(core);
1369 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1370 clk_core_restore_context(core);
1372 EXPORT_SYMBOL_GPL(clk_restore_context);
1375 * clk_enable - ungate a clock
1376 * @clk: the clk being ungated
1378 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
1379 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
1380 * if the operation will never sleep. One example is a SoC-internal clk which
1381 * is controlled via simple register writes. In the complex case a clk ungate
1382 * operation may require a fast and a slow part. It is this reason that
1383 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
1384 * must be called before clk_enable. Returns 0 on success, -EERROR
1387 int clk_enable(struct clk *clk)
1392 return clk_core_enable_lock(clk->core);
1394 EXPORT_SYMBOL_GPL(clk_enable);
1397 * clk_is_enabled_when_prepared - indicate if preparing a clock also enables it.
1398 * @clk: clock source
1400 * Returns true if clk_prepare() implicitly enables the clock, effectively
1401 * making clk_enable()/clk_disable() no-ops, false otherwise.
1403 * This is of interest mainly to power management code where actually
1404 * disabling the clock also requires unpreparing it to have any material
1407 * Regardless of the value returned here, the caller must always invoke
1408 * clk_enable() or clk_prepare_enable() and counterparts for usage counts
1411 bool clk_is_enabled_when_prepared(struct clk *clk)
1413 return clk && !(clk->core->ops->enable && clk->core->ops->disable);
1415 EXPORT_SYMBOL_GPL(clk_is_enabled_when_prepared);
1417 static int clk_core_prepare_enable(struct clk_core *core)
1421 ret = clk_core_prepare_lock(core);
1425 ret = clk_core_enable_lock(core);
1427 clk_core_unprepare_lock(core);
1432 static void clk_core_disable_unprepare(struct clk_core *core)
1434 clk_core_disable_lock(core);
1435 clk_core_unprepare_lock(core);
1438 static void __init clk_unprepare_unused_subtree(struct clk_core *core)
1440 struct clk_core *child;
1442 lockdep_assert_held(&prepare_lock);
1444 hlist_for_each_entry(child, &core->children, child_node)
1445 clk_unprepare_unused_subtree(child);
1447 if (core->prepare_count)
1450 if (core->flags & CLK_IGNORE_UNUSED)
1453 if (clk_core_is_prepared(core)) {
1454 trace_clk_unprepare(core);
1455 if (core->ops->unprepare_unused)
1456 core->ops->unprepare_unused(core->hw);
1457 else if (core->ops->unprepare)
1458 core->ops->unprepare(core->hw);
1459 trace_clk_unprepare_complete(core);
1463 static void __init clk_disable_unused_subtree(struct clk_core *core)
1465 struct clk_core *child;
1466 unsigned long flags;
1468 lockdep_assert_held(&prepare_lock);
1470 hlist_for_each_entry(child, &core->children, child_node)
1471 clk_disable_unused_subtree(child);
1473 if (core->flags & CLK_OPS_PARENT_ENABLE)
1474 clk_core_prepare_enable(core->parent);
1476 flags = clk_enable_lock();
1478 if (core->enable_count)
1481 if (core->flags & CLK_IGNORE_UNUSED)
1485 * some gate clocks have special needs during the disable-unused
1486 * sequence. call .disable_unused if available, otherwise fall
1489 if (clk_core_is_enabled(core)) {
1490 trace_clk_disable(core);
1491 if (core->ops->disable_unused)
1492 core->ops->disable_unused(core->hw);
1493 else if (core->ops->disable)
1494 core->ops->disable(core->hw);
1495 trace_clk_disable_complete(core);
1499 clk_enable_unlock(flags);
1500 if (core->flags & CLK_OPS_PARENT_ENABLE)
1501 clk_core_disable_unprepare(core->parent);
1504 static bool clk_ignore_unused __initdata;
1505 static int __init clk_ignore_unused_setup(char *__unused)
1507 clk_ignore_unused = true;
1510 __setup("clk_ignore_unused", clk_ignore_unused_setup);
1512 static int __init clk_disable_unused(void)
1514 struct clk_core *core;
1517 if (clk_ignore_unused) {
1518 pr_warn("clk: Not disabling unused clocks\n");
1522 pr_info("clk: Disabling unused clocks\n");
1524 ret = clk_pm_runtime_get_all();
1528 * Grab the prepare lock to keep the clk topology stable while iterating
1533 hlist_for_each_entry(core, &clk_root_list, child_node)
1534 clk_disable_unused_subtree(core);
1536 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1537 clk_disable_unused_subtree(core);
1539 hlist_for_each_entry(core, &clk_root_list, child_node)
1540 clk_unprepare_unused_subtree(core);
1542 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1543 clk_unprepare_unused_subtree(core);
1545 clk_prepare_unlock();
1547 clk_pm_runtime_put_all();
1551 late_initcall_sync(clk_disable_unused);
1553 static int clk_core_determine_round_nolock(struct clk_core *core,
1554 struct clk_rate_request *req)
1558 lockdep_assert_held(&prepare_lock);
1564 * Some clock providers hand-craft their clk_rate_requests and
1565 * might not fill min_rate and max_rate.
1567 * If it's the case, clamping the rate is equivalent to setting
1568 * the rate to 0 which is bad. Skip the clamping but complain so
1569 * that it gets fixed, hopefully.
1571 if (!req->min_rate && !req->max_rate)
1572 pr_warn("%s: %s: clk_rate_request has initialized min or max rate.\n",
1573 __func__, core->name);
1575 req->rate = clamp(req->rate, req->min_rate, req->max_rate);
1578 * At this point, core protection will be disabled
1579 * - if the provider is not protected at all
1580 * - if the calling consumer is the only one which has exclusivity
1583 if (clk_core_rate_is_protected(core)) {
1584 req->rate = core->rate;
1585 } else if (core->ops->determine_rate) {
1586 return core->ops->determine_rate(core->hw, req);
1587 } else if (core->ops->round_rate) {
1588 rate = core->ops->round_rate(core->hw, req->rate,
1589 &req->best_parent_rate);
1601 static void clk_core_init_rate_req(struct clk_core * const core,
1602 struct clk_rate_request *req,
1605 struct clk_core *parent;
1610 memset(req, 0, sizeof(*req));
1611 req->max_rate = ULONG_MAX;
1618 clk_core_get_boundaries(core, &req->min_rate, &req->max_rate);
1620 parent = core->parent;
1622 req->best_parent_hw = parent->hw;
1623 req->best_parent_rate = parent->rate;
1625 req->best_parent_hw = NULL;
1626 req->best_parent_rate = 0;
1631 * clk_hw_init_rate_request - Initializes a clk_rate_request
1632 * @hw: the clk for which we want to submit a rate request
1633 * @req: the clk_rate_request structure we want to initialise
1634 * @rate: the rate which is to be requested
1636 * Initializes a clk_rate_request structure to submit to
1637 * __clk_determine_rate() or similar functions.
1639 void clk_hw_init_rate_request(const struct clk_hw *hw,
1640 struct clk_rate_request *req,
1643 if (WARN_ON(!hw || !req))
1646 clk_core_init_rate_req(hw->core, req, rate);
1648 EXPORT_SYMBOL_GPL(clk_hw_init_rate_request);
1651 * clk_hw_forward_rate_request - Forwards a clk_rate_request to a clock's parent
1652 * @hw: the original clock that got the rate request
1653 * @old_req: the original clk_rate_request structure we want to forward
1654 * @parent: the clk we want to forward @old_req to
1655 * @req: the clk_rate_request structure we want to initialise
1656 * @parent_rate: The rate which is to be requested to @parent
1658 * Initializes a clk_rate_request structure to submit to a clock parent
1659 * in __clk_determine_rate() or similar functions.
1661 void clk_hw_forward_rate_request(const struct clk_hw *hw,
1662 const struct clk_rate_request *old_req,
1663 const struct clk_hw *parent,
1664 struct clk_rate_request *req,
1665 unsigned long parent_rate)
1667 if (WARN_ON(!hw || !old_req || !parent || !req))
1670 clk_core_forward_rate_req(hw->core, old_req,
1674 EXPORT_SYMBOL_GPL(clk_hw_forward_rate_request);
1676 static bool clk_core_can_round(struct clk_core * const core)
1678 return core->ops->determine_rate || core->ops->round_rate;
1681 static int clk_core_round_rate_nolock(struct clk_core *core,
1682 struct clk_rate_request *req)
1686 lockdep_assert_held(&prepare_lock);
1693 if (clk_core_can_round(core))
1694 return clk_core_determine_round_nolock(core, req);
1696 if (core->flags & CLK_SET_RATE_PARENT) {
1697 struct clk_rate_request parent_req;
1699 clk_core_forward_rate_req(core, req, core->parent, &parent_req, req->rate);
1701 trace_clk_rate_request_start(&parent_req);
1703 ret = clk_core_round_rate_nolock(core->parent, &parent_req);
1707 trace_clk_rate_request_done(&parent_req);
1709 req->best_parent_rate = parent_req.rate;
1710 req->rate = parent_req.rate;
1715 req->rate = core->rate;
1720 * __clk_determine_rate - get the closest rate actually supported by a clock
1721 * @hw: determine the rate of this clock
1722 * @req: target rate request
1724 * Useful for clk_ops such as .set_rate and .determine_rate.
1726 int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
1733 return clk_core_round_rate_nolock(hw->core, req);
1735 EXPORT_SYMBOL_GPL(__clk_determine_rate);
1738 * clk_hw_round_rate() - round the given rate for a hw clk
1739 * @hw: the hw clk for which we are rounding a rate
1740 * @rate: the rate which is to be rounded
1742 * Takes in a rate as input and rounds it to a rate that the clk can actually
1745 * Context: prepare_lock must be held.
1746 * For clk providers to call from within clk_ops such as .round_rate,
1749 * Return: returns rounded rate of hw clk if clk supports round_rate operation
1750 * else returns the parent rate.
1752 unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
1755 struct clk_rate_request req;
1757 clk_core_init_rate_req(hw->core, &req, rate);
1759 trace_clk_rate_request_start(&req);
1761 ret = clk_core_round_rate_nolock(hw->core, &req);
1765 trace_clk_rate_request_done(&req);
1769 EXPORT_SYMBOL_GPL(clk_hw_round_rate);
1772 * clk_round_rate - round the given rate for a clk
1773 * @clk: the clk for which we are rounding a rate
1774 * @rate: the rate which is to be rounded
1776 * Takes in a rate as input and rounds it to a rate that the clk can actually
1777 * use which is then returned. If clk doesn't support round_rate operation
1778 * then the parent rate is returned.
1780 long clk_round_rate(struct clk *clk, unsigned long rate)
1782 struct clk_rate_request req;
1790 if (clk->exclusive_count)
1791 clk_core_rate_unprotect(clk->core);
1793 clk_core_init_rate_req(clk->core, &req, rate);
1795 trace_clk_rate_request_start(&req);
1797 ret = clk_core_round_rate_nolock(clk->core, &req);
1799 trace_clk_rate_request_done(&req);
1801 if (clk->exclusive_count)
1802 clk_core_rate_protect(clk->core);
1804 clk_prepare_unlock();
1811 EXPORT_SYMBOL_GPL(clk_round_rate);
1814 * __clk_notify - call clk notifier chain
1815 * @core: clk that is changing rate
1816 * @msg: clk notifier type (see include/linux/clk.h)
1817 * @old_rate: old clk rate
1818 * @new_rate: new clk rate
1820 * Triggers a notifier call chain on the clk rate-change notification
1821 * for 'clk'. Passes a pointer to the struct clk and the previous
1822 * and current rates to the notifier callback. Intended to be called by
1823 * internal clock code only. Returns NOTIFY_DONE from the last driver
1824 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1825 * a driver returns that.
1827 static int __clk_notify(struct clk_core *core, unsigned long msg,
1828 unsigned long old_rate, unsigned long new_rate)
1830 struct clk_notifier *cn;
1831 struct clk_notifier_data cnd;
1832 int ret = NOTIFY_DONE;
1834 cnd.old_rate = old_rate;
1835 cnd.new_rate = new_rate;
1837 list_for_each_entry(cn, &clk_notifier_list, node) {
1838 if (cn->clk->core == core) {
1840 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
1842 if (ret & NOTIFY_STOP_MASK)
1851 * __clk_recalc_accuracies
1852 * @core: first clk in the subtree
1854 * Walks the subtree of clks starting with clk and recalculates accuracies as
1855 * it goes. Note that if a clk does not implement the .recalc_accuracy
1856 * callback then it is assumed that the clock will take on the accuracy of its
1859 static void __clk_recalc_accuracies(struct clk_core *core)
1861 unsigned long parent_accuracy = 0;
1862 struct clk_core *child;
1864 lockdep_assert_held(&prepare_lock);
1867 parent_accuracy = core->parent->accuracy;
1869 if (core->ops->recalc_accuracy)
1870 core->accuracy = core->ops->recalc_accuracy(core->hw,
1873 core->accuracy = parent_accuracy;
1875 hlist_for_each_entry(child, &core->children, child_node)
1876 __clk_recalc_accuracies(child);
1879 static long clk_core_get_accuracy_recalc(struct clk_core *core)
1881 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
1882 __clk_recalc_accuracies(core);
1884 return clk_core_get_accuracy_no_lock(core);
1888 * clk_get_accuracy - return the accuracy of clk
1889 * @clk: the clk whose accuracy is being returned
1891 * Simply returns the cached accuracy of the clk, unless
1892 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1894 * If clk is NULL then returns 0.
1896 long clk_get_accuracy(struct clk *clk)
1904 accuracy = clk_core_get_accuracy_recalc(clk->core);
1905 clk_prepare_unlock();
1909 EXPORT_SYMBOL_GPL(clk_get_accuracy);
1911 static unsigned long clk_recalc(struct clk_core *core,
1912 unsigned long parent_rate)
1914 unsigned long rate = parent_rate;
1916 if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
1917 rate = core->ops->recalc_rate(core->hw, parent_rate);
1918 clk_pm_runtime_put(core);
1924 * __clk_recalc_rates
1925 * @core: first clk in the subtree
1926 * @update_req: Whether req_rate should be updated with the new rate
1927 * @msg: notification type (see include/linux/clk.h)
1929 * Walks the subtree of clks starting with clk and recalculates rates as it
1930 * goes. Note that if a clk does not implement the .recalc_rate callback then
1931 * it is assumed that the clock will take on the rate of its parent.
1933 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1936 static void __clk_recalc_rates(struct clk_core *core, bool update_req,
1939 unsigned long old_rate;
1940 unsigned long parent_rate = 0;
1941 struct clk_core *child;
1943 lockdep_assert_held(&prepare_lock);
1945 old_rate = core->rate;
1948 parent_rate = core->parent->rate;
1950 core->rate = clk_recalc(core, parent_rate);
1952 core->req_rate = core->rate;
1955 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1956 * & ABORT_RATE_CHANGE notifiers
1958 if (core->notifier_count && msg)
1959 __clk_notify(core, msg, old_rate, core->rate);
1961 hlist_for_each_entry(child, &core->children, child_node)
1962 __clk_recalc_rates(child, update_req, msg);
1965 static unsigned long clk_core_get_rate_recalc(struct clk_core *core)
1967 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1968 __clk_recalc_rates(core, false, 0);
1970 return clk_core_get_rate_nolock(core);
1974 * clk_get_rate - return the rate of clk
1975 * @clk: the clk whose rate is being returned
1977 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1978 * is set, which means a recalc_rate will be issued. Can be called regardless of
1979 * the clock enabledness. If clk is NULL, or if an error occurred, then returns
1982 unsigned long clk_get_rate(struct clk *clk)
1990 rate = clk_core_get_rate_recalc(clk->core);
1991 clk_prepare_unlock();
1995 EXPORT_SYMBOL_GPL(clk_get_rate);
1997 static int clk_fetch_parent_index(struct clk_core *core,
1998 struct clk_core *parent)
2005 for (i = 0; i < core->num_parents; i++) {
2006 /* Found it first try! */
2007 if (core->parents[i].core == parent)
2010 /* Something else is here, so keep looking */
2011 if (core->parents[i].core)
2014 /* Maybe core hasn't been cached but the hw is all we know? */
2015 if (core->parents[i].hw) {
2016 if (core->parents[i].hw == parent->hw)
2019 /* Didn't match, but we're expecting a clk_hw */
2023 /* Maybe it hasn't been cached (clk_set_parent() path) */
2024 if (parent == clk_core_get(core, i))
2027 /* Fallback to comparing globally unique names */
2028 if (core->parents[i].name &&
2029 !strcmp(parent->name, core->parents[i].name))
2033 if (i == core->num_parents)
2036 core->parents[i].core = parent;
2041 * clk_hw_get_parent_index - return the index of the parent clock
2042 * @hw: clk_hw associated with the clk being consumed
2044 * Fetches and returns the index of parent clock. Returns -EINVAL if the given
2045 * clock does not have a current parent.
2047 int clk_hw_get_parent_index(struct clk_hw *hw)
2049 struct clk_hw *parent = clk_hw_get_parent(hw);
2051 if (WARN_ON(parent == NULL))
2054 return clk_fetch_parent_index(hw->core, parent->core);
2056 EXPORT_SYMBOL_GPL(clk_hw_get_parent_index);
2059 * Update the orphan status of @core and all its children.
2061 static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
2063 struct clk_core *child;
2065 core->orphan = is_orphan;
2067 hlist_for_each_entry(child, &core->children, child_node)
2068 clk_core_update_orphan_status(child, is_orphan);
2071 static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
2073 bool was_orphan = core->orphan;
2075 hlist_del(&core->child_node);
2078 bool becomes_orphan = new_parent->orphan;
2080 /* avoid duplicate POST_RATE_CHANGE notifications */
2081 if (new_parent->new_child == core)
2082 new_parent->new_child = NULL;
2084 hlist_add_head(&core->child_node, &new_parent->children);
2086 if (was_orphan != becomes_orphan)
2087 clk_core_update_orphan_status(core, becomes_orphan);
2089 hlist_add_head(&core->child_node, &clk_orphan_list);
2091 clk_core_update_orphan_status(core, true);
2094 core->parent = new_parent;
2097 static struct clk_core *__clk_set_parent_before(struct clk_core *core,
2098 struct clk_core *parent)
2100 unsigned long flags;
2101 struct clk_core *old_parent = core->parent;
2104 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
2106 * 2. Migrate prepare state between parents and prevent race with
2109 * If the clock is not prepared, then a race with
2110 * clk_enable/disable() is impossible since we already have the
2111 * prepare lock (future calls to clk_enable() need to be preceded by
2114 * If the clock is prepared, migrate the prepared state to the new
2115 * parent and also protect against a race with clk_enable() by
2116 * forcing the clock and the new parent on. This ensures that all
2117 * future calls to clk_enable() are practically NOPs with respect to
2118 * hardware and software states.
2120 * See also: Comment for clk_set_parent() below.
2123 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
2124 if (core->flags & CLK_OPS_PARENT_ENABLE) {
2125 clk_core_prepare_enable(old_parent);
2126 clk_core_prepare_enable(parent);
2129 /* migrate prepare count if > 0 */
2130 if (core->prepare_count) {
2131 clk_core_prepare_enable(parent);
2132 clk_core_enable_lock(core);
2135 /* update the clk tree topology */
2136 flags = clk_enable_lock();
2137 clk_reparent(core, parent);
2138 clk_enable_unlock(flags);
2143 static void __clk_set_parent_after(struct clk_core *core,
2144 struct clk_core *parent,
2145 struct clk_core *old_parent)
2148 * Finish the migration of prepare state and undo the changes done
2149 * for preventing a race with clk_enable().
2151 if (core->prepare_count) {
2152 clk_core_disable_lock(core);
2153 clk_core_disable_unprepare(old_parent);
2156 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
2157 if (core->flags & CLK_OPS_PARENT_ENABLE) {
2158 clk_core_disable_unprepare(parent);
2159 clk_core_disable_unprepare(old_parent);
2163 static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
2166 unsigned long flags;
2168 struct clk_core *old_parent;
2170 old_parent = __clk_set_parent_before(core, parent);
2172 trace_clk_set_parent(core, parent);
2174 /* change clock input source */
2175 if (parent && core->ops->set_parent)
2176 ret = core->ops->set_parent(core->hw, p_index);
2178 trace_clk_set_parent_complete(core, parent);
2181 flags = clk_enable_lock();
2182 clk_reparent(core, old_parent);
2183 clk_enable_unlock(flags);
2185 __clk_set_parent_after(core, old_parent, parent);
2190 __clk_set_parent_after(core, parent, old_parent);
2196 * __clk_speculate_rates
2197 * @core: first clk in the subtree
2198 * @parent_rate: the "future" rate of clk's parent
2200 * Walks the subtree of clks starting with clk, speculating rates as it
2201 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
2203 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
2204 * pre-rate change notifications and returns early if no clks in the
2205 * subtree have subscribed to the notifications. Note that if a clk does not
2206 * implement the .recalc_rate callback then it is assumed that the clock will
2207 * take on the rate of its parent.
2209 static int __clk_speculate_rates(struct clk_core *core,
2210 unsigned long parent_rate)
2212 struct clk_core *child;
2213 unsigned long new_rate;
2214 int ret = NOTIFY_DONE;
2216 lockdep_assert_held(&prepare_lock);
2218 new_rate = clk_recalc(core, parent_rate);
2220 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
2221 if (core->notifier_count)
2222 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
2224 if (ret & NOTIFY_STOP_MASK) {
2225 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
2226 __func__, core->name, ret);
2230 hlist_for_each_entry(child, &core->children, child_node) {
2231 ret = __clk_speculate_rates(child, new_rate);
2232 if (ret & NOTIFY_STOP_MASK)
2240 static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
2241 struct clk_core *new_parent, u8 p_index)
2243 struct clk_core *child;
2245 core->new_rate = new_rate;
2246 core->new_parent = new_parent;
2247 core->new_parent_index = p_index;
2248 /* include clk in new parent's PRE_RATE_CHANGE notifications */
2249 core->new_child = NULL;
2250 if (new_parent && new_parent != core->parent)
2251 new_parent->new_child = core;
2253 hlist_for_each_entry(child, &core->children, child_node) {
2254 child->new_rate = clk_recalc(child, new_rate);
2255 clk_calc_subtree(child, child->new_rate, NULL, 0);
2260 * calculate the new rates returning the topmost clock that has to be
2263 static struct clk_core *clk_calc_new_rates(struct clk_core *core,
2266 struct clk_core *top = core;
2267 struct clk_core *old_parent, *parent;
2268 unsigned long best_parent_rate = 0;
2269 unsigned long new_rate;
2270 unsigned long min_rate;
2271 unsigned long max_rate;
2276 if (IS_ERR_OR_NULL(core))
2279 /* save parent rate, if it exists */
2280 parent = old_parent = core->parent;
2282 best_parent_rate = parent->rate;
2284 clk_core_get_boundaries(core, &min_rate, &max_rate);
2286 /* find the closest rate and parent clk/rate */
2287 if (clk_core_can_round(core)) {
2288 struct clk_rate_request req;
2290 clk_core_init_rate_req(core, &req, rate);
2292 trace_clk_rate_request_start(&req);
2294 ret = clk_core_determine_round_nolock(core, &req);
2298 trace_clk_rate_request_done(&req);
2300 best_parent_rate = req.best_parent_rate;
2301 new_rate = req.rate;
2302 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
2304 if (new_rate < min_rate || new_rate > max_rate)
2306 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
2307 /* pass-through clock without adjustable parent */
2308 core->new_rate = core->rate;
2311 /* pass-through clock with adjustable parent */
2312 top = clk_calc_new_rates(parent, rate);
2313 new_rate = parent->new_rate;
2317 /* some clocks must be gated to change parent */
2318 if (parent != old_parent &&
2319 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
2320 pr_debug("%s: %s not gated but wants to reparent\n",
2321 __func__, core->name);
2325 /* try finding the new parent index */
2326 if (parent && core->num_parents > 1) {
2327 p_index = clk_fetch_parent_index(core, parent);
2329 pr_debug("%s: clk %s can not be parent of clk %s\n",
2330 __func__, parent->name, core->name);
2335 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
2336 best_parent_rate != parent->rate)
2337 top = clk_calc_new_rates(parent, best_parent_rate);
2340 clk_calc_subtree(core, new_rate, parent, p_index);
2346 * Notify about rate changes in a subtree. Always walk down the whole tree
2347 * so that in case of an error we can walk down the whole tree again and
2350 static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
2351 unsigned long event)
2353 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
2354 int ret = NOTIFY_DONE;
2356 if (core->rate == core->new_rate)
2359 if (core->notifier_count) {
2360 ret = __clk_notify(core, event, core->rate, core->new_rate);
2361 if (ret & NOTIFY_STOP_MASK)
2365 hlist_for_each_entry(child, &core->children, child_node) {
2366 /* Skip children who will be reparented to another clock */
2367 if (child->new_parent && child->new_parent != core)
2369 tmp_clk = clk_propagate_rate_change(child, event);
2374 /* handle the new child who might not be in core->children yet */
2375 if (core->new_child) {
2376 tmp_clk = clk_propagate_rate_change(core->new_child, event);
2385 * walk down a subtree and set the new rates notifying the rate
2388 static void clk_change_rate(struct clk_core *core)
2390 struct clk_core *child;
2391 struct hlist_node *tmp;
2392 unsigned long old_rate;
2393 unsigned long best_parent_rate = 0;
2394 bool skip_set_rate = false;
2395 struct clk_core *old_parent;
2396 struct clk_core *parent = NULL;
2398 old_rate = core->rate;
2400 if (core->new_parent) {
2401 parent = core->new_parent;
2402 best_parent_rate = core->new_parent->rate;
2403 } else if (core->parent) {
2404 parent = core->parent;
2405 best_parent_rate = core->parent->rate;
2408 if (clk_pm_runtime_get(core))
2411 if (core->flags & CLK_SET_RATE_UNGATE) {
2412 clk_core_prepare(core);
2413 clk_core_enable_lock(core);
2416 if (core->new_parent && core->new_parent != core->parent) {
2417 old_parent = __clk_set_parent_before(core, core->new_parent);
2418 trace_clk_set_parent(core, core->new_parent);
2420 if (core->ops->set_rate_and_parent) {
2421 skip_set_rate = true;
2422 core->ops->set_rate_and_parent(core->hw, core->new_rate,
2424 core->new_parent_index);
2425 } else if (core->ops->set_parent) {
2426 core->ops->set_parent(core->hw, core->new_parent_index);
2429 trace_clk_set_parent_complete(core, core->new_parent);
2430 __clk_set_parent_after(core, core->new_parent, old_parent);
2433 if (core->flags & CLK_OPS_PARENT_ENABLE)
2434 clk_core_prepare_enable(parent);
2436 trace_clk_set_rate(core, core->new_rate);
2438 if (!skip_set_rate && core->ops->set_rate)
2439 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
2441 trace_clk_set_rate_complete(core, core->new_rate);
2443 core->rate = clk_recalc(core, best_parent_rate);
2445 if (core->flags & CLK_SET_RATE_UNGATE) {
2446 clk_core_disable_lock(core);
2447 clk_core_unprepare(core);
2450 if (core->flags & CLK_OPS_PARENT_ENABLE)
2451 clk_core_disable_unprepare(parent);
2453 if (core->notifier_count && old_rate != core->rate)
2454 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
2456 if (core->flags & CLK_RECALC_NEW_RATES)
2457 (void)clk_calc_new_rates(core, core->new_rate);
2460 * Use safe iteration, as change_rate can actually swap parents
2461 * for certain clock types.
2463 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
2464 /* Skip children who will be reparented to another clock */
2465 if (child->new_parent && child->new_parent != core)
2467 clk_change_rate(child);
2470 /* handle the new child who might not be in core->children yet */
2471 if (core->new_child)
2472 clk_change_rate(core->new_child);
2474 clk_pm_runtime_put(core);
2477 static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
2478 unsigned long req_rate)
2481 struct clk_rate_request req;
2483 lockdep_assert_held(&prepare_lock);
2488 /* simulate what the rate would be if it could be freely set */
2489 cnt = clk_core_rate_nuke_protect(core);
2493 clk_core_init_rate_req(core, &req, req_rate);
2495 trace_clk_rate_request_start(&req);
2497 ret = clk_core_round_rate_nolock(core, &req);
2499 trace_clk_rate_request_done(&req);
2501 /* restore the protection */
2502 clk_core_rate_restore_protect(core, cnt);
2504 return ret ? 0 : req.rate;
2507 static int clk_core_set_rate_nolock(struct clk_core *core,
2508 unsigned long req_rate)
2510 struct clk_core *top, *fail_clk;
2517 rate = clk_core_req_round_rate_nolock(core, req_rate);
2519 /* bail early if nothing to do */
2520 if (rate == clk_core_get_rate_nolock(core))
2523 /* fail on a direct rate set of a protected provider */
2524 if (clk_core_rate_is_protected(core))
2527 /* calculate new rates and get the topmost changed clock */
2528 top = clk_calc_new_rates(core, req_rate);
2532 ret = clk_pm_runtime_get(core);
2536 /* notify that we are about to change rates */
2537 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
2539 pr_debug("%s: failed to set %s rate\n", __func__,
2541 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
2546 /* change the rates */
2547 clk_change_rate(top);
2549 core->req_rate = req_rate;
2551 clk_pm_runtime_put(core);
2557 * clk_set_rate - specify a new rate for clk
2558 * @clk: the clk whose rate is being changed
2559 * @rate: the new rate for clk
2561 * In the simplest case clk_set_rate will only adjust the rate of clk.
2563 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
2564 * propagate up to clk's parent; whether or not this happens depends on the
2565 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
2566 * after calling .round_rate then upstream parent propagation is ignored. If
2567 * *parent_rate comes back with a new rate for clk's parent then we propagate
2568 * up to clk's parent and set its rate. Upward propagation will continue
2569 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
2570 * .round_rate stops requesting changes to clk's parent_rate.
2572 * Rate changes are accomplished via tree traversal that also recalculates the
2573 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
2575 * Returns 0 on success, -EERROR otherwise.
2577 int clk_set_rate(struct clk *clk, unsigned long rate)
2584 /* prevent racing with updates to the clock topology */
2587 if (clk->exclusive_count)
2588 clk_core_rate_unprotect(clk->core);
2590 ret = clk_core_set_rate_nolock(clk->core, rate);
2592 if (clk->exclusive_count)
2593 clk_core_rate_protect(clk->core);
2595 clk_prepare_unlock();
2599 EXPORT_SYMBOL_GPL(clk_set_rate);
2602 * clk_set_rate_exclusive - specify a new rate and get exclusive control
2603 * @clk: the clk whose rate is being changed
2604 * @rate: the new rate for clk
2606 * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
2607 * within a critical section
2609 * This can be used initially to ensure that at least 1 consumer is
2610 * satisfied when several consumers are competing for exclusivity over the
2611 * same clock provider.
2613 * The exclusivity is not applied if setting the rate failed.
2615 * Calls to clk_rate_exclusive_get() should be balanced with calls to
2616 * clk_rate_exclusive_put().
2618 * Returns 0 on success, -EERROR otherwise.
2620 int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
2627 /* prevent racing with updates to the clock topology */
2631 * The temporary protection removal is not here, on purpose
2632 * This function is meant to be used instead of clk_rate_protect,
2633 * so before the consumer code path protect the clock provider
2636 ret = clk_core_set_rate_nolock(clk->core, rate);
2638 clk_core_rate_protect(clk->core);
2639 clk->exclusive_count++;
2642 clk_prepare_unlock();
2646 EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
2648 static int clk_set_rate_range_nolock(struct clk *clk,
2653 unsigned long old_min, old_max, rate;
2655 lockdep_assert_held(&prepare_lock);
2660 trace_clk_set_rate_range(clk->core, min, max);
2663 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
2664 __func__, clk->core->name, clk->dev_id, clk->con_id,
2669 if (clk->exclusive_count)
2670 clk_core_rate_unprotect(clk->core);
2672 /* Save the current values in case we need to rollback the change */
2673 old_min = clk->min_rate;
2674 old_max = clk->max_rate;
2675 clk->min_rate = min;
2676 clk->max_rate = max;
2678 if (!clk_core_check_boundaries(clk->core, min, max)) {
2683 rate = clk->core->req_rate;
2684 if (clk->core->flags & CLK_GET_RATE_NOCACHE)
2685 rate = clk_core_get_rate_recalc(clk->core);
2688 * Since the boundaries have been changed, let's give the
2689 * opportunity to the provider to adjust the clock rate based on
2690 * the new boundaries.
2692 * We also need to handle the case where the clock is currently
2693 * outside of the boundaries. Clamping the last requested rate
2694 * to the current minimum and maximum will also handle this.
2697 * There is a catch. It may fail for the usual reason (clock
2698 * broken, clock protected, etc) but also because:
2699 * - round_rate() was not favorable and fell on the wrong
2700 * side of the boundary
2701 * - the determine_rate() callback does not really check for
2702 * this corner case when determining the rate
2704 rate = clamp(rate, min, max);
2705 ret = clk_core_set_rate_nolock(clk->core, rate);
2707 /* rollback the changes */
2708 clk->min_rate = old_min;
2709 clk->max_rate = old_max;
2713 if (clk->exclusive_count)
2714 clk_core_rate_protect(clk->core);
2720 * clk_set_rate_range - set a rate range for a clock source
2721 * @clk: clock source
2722 * @min: desired minimum clock rate in Hz, inclusive
2723 * @max: desired maximum clock rate in Hz, inclusive
2725 * Return: 0 for success or negative errno on failure.
2727 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
2736 ret = clk_set_rate_range_nolock(clk, min, max);
2738 clk_prepare_unlock();
2742 EXPORT_SYMBOL_GPL(clk_set_rate_range);
2745 * clk_set_min_rate - set a minimum clock rate for a clock source
2746 * @clk: clock source
2747 * @rate: desired minimum clock rate in Hz, inclusive
2749 * Returns success (0) or negative errno.
2751 int clk_set_min_rate(struct clk *clk, unsigned long rate)
2756 trace_clk_set_min_rate(clk->core, rate);
2758 return clk_set_rate_range(clk, rate, clk->max_rate);
2760 EXPORT_SYMBOL_GPL(clk_set_min_rate);
2763 * clk_set_max_rate - set a maximum clock rate for a clock source
2764 * @clk: clock source
2765 * @rate: desired maximum clock rate in Hz, inclusive
2767 * Returns success (0) or negative errno.
2769 int clk_set_max_rate(struct clk *clk, unsigned long rate)
2774 trace_clk_set_max_rate(clk->core, rate);
2776 return clk_set_rate_range(clk, clk->min_rate, rate);
2778 EXPORT_SYMBOL_GPL(clk_set_max_rate);
2781 * clk_get_parent - return the parent of a clk
2782 * @clk: the clk whose parent gets returned
2784 * Simply returns clk->parent. Returns NULL if clk is NULL.
2786 struct clk *clk_get_parent(struct clk *clk)
2794 /* TODO: Create a per-user clk and change callers to call clk_put */
2795 parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
2796 clk_prepare_unlock();
2800 EXPORT_SYMBOL_GPL(clk_get_parent);
2802 static struct clk_core *__clk_init_parent(struct clk_core *core)
2806 if (core->num_parents > 1 && core->ops->get_parent)
2807 index = core->ops->get_parent(core->hw);
2809 return clk_core_get_parent_by_index(core, index);
2812 static void clk_core_reparent(struct clk_core *core,
2813 struct clk_core *new_parent)
2815 clk_reparent(core, new_parent);
2816 __clk_recalc_accuracies(core);
2817 __clk_recalc_rates(core, true, POST_RATE_CHANGE);
2820 void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
2825 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
2829 * clk_has_parent - check if a clock is a possible parent for another
2830 * @clk: clock source
2831 * @parent: parent clock source
2833 * This function can be used in drivers that need to check that a clock can be
2834 * the parent of another without actually changing the parent.
2836 * Returns true if @parent is a possible parent for @clk, false otherwise.
2838 bool clk_has_parent(const struct clk *clk, const struct clk *parent)
2840 /* NULL clocks should be nops, so return success if either is NULL. */
2841 if (!clk || !parent)
2844 return clk_core_has_parent(clk->core, parent->core);
2846 EXPORT_SYMBOL_GPL(clk_has_parent);
2848 static int clk_core_set_parent_nolock(struct clk_core *core,
2849 struct clk_core *parent)
2853 unsigned long p_rate = 0;
2855 lockdep_assert_held(&prepare_lock);
2860 if (core->parent == parent)
2863 /* verify ops for multi-parent clks */
2864 if (core->num_parents > 1 && !core->ops->set_parent)
2867 /* check that we are allowed to re-parent if the clock is in use */
2868 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
2871 if (clk_core_rate_is_protected(core))
2874 /* try finding the new parent index */
2876 p_index = clk_fetch_parent_index(core, parent);
2878 pr_debug("%s: clk %s can not be parent of clk %s\n",
2879 __func__, parent->name, core->name);
2882 p_rate = parent->rate;
2885 ret = clk_pm_runtime_get(core);
2889 /* propagate PRE_RATE_CHANGE notifications */
2890 ret = __clk_speculate_rates(core, p_rate);
2892 /* abort if a driver objects */
2893 if (ret & NOTIFY_STOP_MASK)
2896 /* do the re-parent */
2897 ret = __clk_set_parent(core, parent, p_index);
2899 /* propagate rate an accuracy recalculation accordingly */
2901 __clk_recalc_rates(core, true, ABORT_RATE_CHANGE);
2903 __clk_recalc_rates(core, true, POST_RATE_CHANGE);
2904 __clk_recalc_accuracies(core);
2908 clk_pm_runtime_put(core);
2913 int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *parent)
2915 return clk_core_set_parent_nolock(hw->core, parent->core);
2917 EXPORT_SYMBOL_GPL(clk_hw_set_parent);
2920 * clk_set_parent - switch the parent of a mux clk
2921 * @clk: the mux clk whose input we are switching
2922 * @parent: the new input to clk
2924 * Re-parent clk to use parent as its new input source. If clk is in
2925 * prepared state, the clk will get enabled for the duration of this call. If
2926 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2927 * that, the reparenting is glitchy in hardware, etc), use the
2928 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2930 * After successfully changing clk's parent clk_set_parent will update the
2931 * clk topology, sysfs topology and propagate rate recalculation via
2932 * __clk_recalc_rates.
2934 * Returns 0 on success, -EERROR otherwise.
2936 int clk_set_parent(struct clk *clk, struct clk *parent)
2945 if (clk->exclusive_count)
2946 clk_core_rate_unprotect(clk->core);
2948 ret = clk_core_set_parent_nolock(clk->core,
2949 parent ? parent->core : NULL);
2951 if (clk->exclusive_count)
2952 clk_core_rate_protect(clk->core);
2954 clk_prepare_unlock();
2958 EXPORT_SYMBOL_GPL(clk_set_parent);
2960 static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
2964 lockdep_assert_held(&prepare_lock);
2969 if (clk_core_rate_is_protected(core))
2972 trace_clk_set_phase(core, degrees);
2974 if (core->ops->set_phase) {
2975 ret = core->ops->set_phase(core->hw, degrees);
2977 core->phase = degrees;
2980 trace_clk_set_phase_complete(core, degrees);
2986 * clk_set_phase - adjust the phase shift of a clock signal
2987 * @clk: clock signal source
2988 * @degrees: number of degrees the signal is shifted
2990 * Shifts the phase of a clock signal by the specified
2991 * degrees. Returns 0 on success, -EERROR otherwise.
2993 * This function makes no distinction about the input or reference
2994 * signal that we adjust the clock signal phase against. For example
2995 * phase locked-loop clock signal generators we may shift phase with
2996 * respect to feedback clock signal input, but for other cases the
2997 * clock phase may be shifted with respect to some other, unspecified
3000 * Additionally the concept of phase shift does not propagate through
3001 * the clock tree hierarchy, which sets it apart from clock rates and
3002 * clock accuracy. A parent clock phase attribute does not have an
3003 * impact on the phase attribute of a child clock.
3005 int clk_set_phase(struct clk *clk, int degrees)
3012 /* sanity check degrees */
3019 if (clk->exclusive_count)
3020 clk_core_rate_unprotect(clk->core);
3022 ret = clk_core_set_phase_nolock(clk->core, degrees);
3024 if (clk->exclusive_count)
3025 clk_core_rate_protect(clk->core);
3027 clk_prepare_unlock();
3031 EXPORT_SYMBOL_GPL(clk_set_phase);
3033 static int clk_core_get_phase(struct clk_core *core)
3037 lockdep_assert_held(&prepare_lock);
3038 if (!core->ops->get_phase)
3041 /* Always try to update cached phase if possible */
3042 ret = core->ops->get_phase(core->hw);
3050 * clk_get_phase - return the phase shift of a clock signal
3051 * @clk: clock signal source
3053 * Returns the phase shift of a clock node in degrees, otherwise returns
3056 int clk_get_phase(struct clk *clk)
3064 ret = clk_core_get_phase(clk->core);
3065 clk_prepare_unlock();
3069 EXPORT_SYMBOL_GPL(clk_get_phase);
3071 static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
3073 /* Assume a default value of 50% */
3078 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);
3080 static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
3082 struct clk_duty *duty = &core->duty;
3085 if (!core->ops->get_duty_cycle)
3086 return clk_core_update_duty_cycle_parent_nolock(core);
3088 ret = core->ops->get_duty_cycle(core->hw, duty);
3092 /* Don't trust the clock provider too much */
3093 if (duty->den == 0 || duty->num > duty->den) {
3101 clk_core_reset_duty_cycle_nolock(core);
3105 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
3110 core->flags & CLK_DUTY_CYCLE_PARENT) {
3111 ret = clk_core_update_duty_cycle_nolock(core->parent);
3112 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
3114 clk_core_reset_duty_cycle_nolock(core);
3120 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
3121 struct clk_duty *duty);
3123 static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
3124 struct clk_duty *duty)
3128 lockdep_assert_held(&prepare_lock);
3130 if (clk_core_rate_is_protected(core))
3133 trace_clk_set_duty_cycle(core, duty);
3135 if (!core->ops->set_duty_cycle)
3136 return clk_core_set_duty_cycle_parent_nolock(core, duty);
3138 ret = core->ops->set_duty_cycle(core->hw, duty);
3140 memcpy(&core->duty, duty, sizeof(*duty));
3142 trace_clk_set_duty_cycle_complete(core, duty);
3147 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
3148 struct clk_duty *duty)
3153 core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
3154 ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
3155 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
3162 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
3163 * @clk: clock signal source
3164 * @num: numerator of the duty cycle ratio to be applied
3165 * @den: denominator of the duty cycle ratio to be applied
3167 * Apply the duty cycle ratio if the ratio is valid and the clock can
3168 * perform this operation
3170 * Returns (0) on success, a negative errno otherwise.
3172 int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
3175 struct clk_duty duty;
3180 /* sanity check the ratio */
3181 if (den == 0 || num > den)
3189 if (clk->exclusive_count)
3190 clk_core_rate_unprotect(clk->core);
3192 ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
3194 if (clk->exclusive_count)
3195 clk_core_rate_protect(clk->core);
3197 clk_prepare_unlock();
3201 EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
3203 static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
3206 struct clk_duty *duty = &core->duty;
3211 ret = clk_core_update_duty_cycle_nolock(core);
3213 ret = mult_frac(scale, duty->num, duty->den);
3215 clk_prepare_unlock();
3221 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
3222 * @clk: clock signal source
3223 * @scale: scaling factor to be applied to represent the ratio as an integer
3225 * Returns the duty cycle ratio of a clock node multiplied by the provided
3226 * scaling factor, or negative errno on error.
3228 int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
3233 return clk_core_get_scaled_duty_cycle(clk->core, scale);
3235 EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
3238 * clk_is_match - check if two clk's point to the same hardware clock
3239 * @p: clk compared against q
3240 * @q: clk compared against p
3242 * Returns true if the two struct clk pointers both point to the same hardware
3243 * clock node. Put differently, returns true if struct clk *p and struct clk *q
3244 * share the same struct clk_core object.
3246 * Returns false otherwise. Note that two NULL clks are treated as matching.
3248 bool clk_is_match(const struct clk *p, const struct clk *q)
3250 /* trivial case: identical struct clk's or both NULL */
3254 /* true if clk->core pointers match. Avoid dereferencing garbage */
3255 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
3256 if (p->core == q->core)
3261 EXPORT_SYMBOL_GPL(clk_is_match);
3263 /*** debugfs support ***/
3265 #ifdef CONFIG_DEBUG_FS
3266 #include <linux/debugfs.h>
3268 static struct dentry *rootdir;
3269 static int inited = 0;
3270 static DEFINE_MUTEX(clk_debug_lock);
3271 static HLIST_HEAD(clk_debug_list);
3273 static struct hlist_head *orphan_list[] = {
3278 static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
3282 struct clk *clk_user;
3285 seq_printf(s, "%*s%-*s %-7d %-8d %-8d %-11lu %-10lu ",
3287 35 - level * 3, c->name,
3288 c->enable_count, c->prepare_count, c->protect_count,
3289 clk_core_get_rate_recalc(c),
3290 clk_core_get_accuracy_recalc(c));
3292 phase = clk_core_get_phase(c);
3294 seq_printf(s, "%-5d", phase);
3296 seq_puts(s, "-----");
3298 seq_printf(s, " %-6d", clk_core_get_scaled_duty_cycle(c, 100000));
3300 if (c->ops->is_enabled)
3301 seq_printf(s, " %5c ", clk_core_is_enabled(c) ? 'Y' : 'N');
3302 else if (!c->ops->enable)
3303 seq_printf(s, " %5c ", 'Y');
3305 seq_printf(s, " %5c ", '?');
3307 hlist_for_each_entry(clk_user, &c->clks, clks_node) {
3308 seq_printf(s, "%*s%-*s %-25s\n",
3309 level * 3 + 2 + 105 * multi_node, "",
3311 clk_user->dev_id ? clk_user->dev_id : "deviceless",
3312 clk_user->con_id ? clk_user->con_id : "no_connection_id");
3319 static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
3322 struct clk_core *child;
3324 clk_summary_show_one(s, c, level);
3326 hlist_for_each_entry(child, &c->children, child_node)
3327 clk_summary_show_subtree(s, child, level + 1);
3330 static int clk_summary_show(struct seq_file *s, void *data)
3333 struct hlist_head **lists = s->private;
3336 seq_puts(s, " enable prepare protect duty hardware connection\n");
3337 seq_puts(s, " clock count count count rate accuracy phase cycle enable consumer id\n");
3338 seq_puts(s, "---------------------------------------------------------------------------------------------------------------------------------------------\n");
3340 ret = clk_pm_runtime_get_all();
3346 for (; *lists; lists++)
3347 hlist_for_each_entry(c, *lists, child_node)
3348 clk_summary_show_subtree(s, c, 0);
3350 clk_prepare_unlock();
3351 clk_pm_runtime_put_all();
3355 DEFINE_SHOW_ATTRIBUTE(clk_summary);
3357 static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
3360 unsigned long min_rate, max_rate;
3362 clk_core_get_boundaries(c, &min_rate, &max_rate);
3364 /* This should be JSON format, i.e. elements separated with a comma */
3365 seq_printf(s, "\"%s\": { ", c->name);
3366 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
3367 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
3368 seq_printf(s, "\"protect_count\": %d,", c->protect_count);
3369 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate_recalc(c));
3370 seq_printf(s, "\"min_rate\": %lu,", min_rate);
3371 seq_printf(s, "\"max_rate\": %lu,", max_rate);
3372 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy_recalc(c));
3373 phase = clk_core_get_phase(c);
3375 seq_printf(s, "\"phase\": %d,", phase);
3376 seq_printf(s, "\"duty_cycle\": %u",
3377 clk_core_get_scaled_duty_cycle(c, 100000));
3380 static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
3382 struct clk_core *child;
3384 clk_dump_one(s, c, level);
3386 hlist_for_each_entry(child, &c->children, child_node) {
3388 clk_dump_subtree(s, child, level + 1);
3394 static int clk_dump_show(struct seq_file *s, void *data)
3397 bool first_node = true;
3398 struct hlist_head **lists = s->private;
3401 ret = clk_pm_runtime_get_all();
3409 for (; *lists; lists++) {
3410 hlist_for_each_entry(c, *lists, child_node) {
3414 clk_dump_subtree(s, c, 0);
3418 clk_prepare_unlock();
3419 clk_pm_runtime_put_all();
3424 DEFINE_SHOW_ATTRIBUTE(clk_dump);
3426 #undef CLOCK_ALLOW_WRITE_DEBUGFS
3427 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3429 * This can be dangerous, therefore don't provide any real compile time
3430 * configuration option for this feature.
3431 * People who want to use this will need to modify the source code directly.
3433 static int clk_rate_set(void *data, u64 val)
3435 struct clk_core *core = data;
3439 ret = clk_core_set_rate_nolock(core, val);
3440 clk_prepare_unlock();
3445 #define clk_rate_mode 0644
3447 static int clk_phase_set(void *data, u64 val)
3449 struct clk_core *core = data;
3450 int degrees = do_div(val, 360);
3454 ret = clk_core_set_phase_nolock(core, degrees);
3455 clk_prepare_unlock();
3460 #define clk_phase_mode 0644
3462 static int clk_prepare_enable_set(void *data, u64 val)
3464 struct clk_core *core = data;
3468 ret = clk_prepare_enable(core->hw->clk);
3470 clk_disable_unprepare(core->hw->clk);
3475 static int clk_prepare_enable_get(void *data, u64 *val)
3477 struct clk_core *core = data;
3479 *val = core->enable_count && core->prepare_count;
3483 DEFINE_DEBUGFS_ATTRIBUTE(clk_prepare_enable_fops, clk_prepare_enable_get,
3484 clk_prepare_enable_set, "%llu\n");
3487 #define clk_rate_set NULL
3488 #define clk_rate_mode 0444
3490 #define clk_phase_set NULL
3491 #define clk_phase_mode 0644
3494 static int clk_rate_get(void *data, u64 *val)
3496 struct clk_core *core = data;
3499 *val = clk_core_get_rate_recalc(core);
3500 clk_prepare_unlock();
3505 DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops, clk_rate_get, clk_rate_set, "%llu\n");
3507 static int clk_phase_get(void *data, u64 *val)
3509 struct clk_core *core = data;
3515 DEFINE_DEBUGFS_ATTRIBUTE(clk_phase_fops, clk_phase_get, clk_phase_set, "%llu\n");
3517 static const struct {
3521 #define ENTRY(f) { f, #f }
3522 ENTRY(CLK_SET_RATE_GATE),
3523 ENTRY(CLK_SET_PARENT_GATE),
3524 ENTRY(CLK_SET_RATE_PARENT),
3525 ENTRY(CLK_IGNORE_UNUSED),
3526 ENTRY(CLK_GET_RATE_NOCACHE),
3527 ENTRY(CLK_SET_RATE_NO_REPARENT),
3528 ENTRY(CLK_GET_ACCURACY_NOCACHE),
3529 ENTRY(CLK_RECALC_NEW_RATES),
3530 ENTRY(CLK_SET_RATE_UNGATE),
3531 ENTRY(CLK_IS_CRITICAL),
3532 ENTRY(CLK_OPS_PARENT_ENABLE),
3533 ENTRY(CLK_DUTY_CYCLE_PARENT),
3537 static int clk_flags_show(struct seq_file *s, void *data)
3539 struct clk_core *core = s->private;
3540 unsigned long flags = core->flags;
3543 for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
3544 if (flags & clk_flags[i].flag) {
3545 seq_printf(s, "%s\n", clk_flags[i].name);
3546 flags &= ~clk_flags[i].flag;
3551 seq_printf(s, "0x%lx\n", flags);
3556 DEFINE_SHOW_ATTRIBUTE(clk_flags);
3558 static void possible_parent_show(struct seq_file *s, struct clk_core *core,
3559 unsigned int i, char terminator)
3561 struct clk_core *parent;
3562 const char *name = NULL;
3565 * Go through the following options to fetch a parent's name.
3567 * 1. Fetch the registered parent clock and use its name
3568 * 2. Use the global (fallback) name if specified
3569 * 3. Use the local fw_name if provided
3570 * 4. Fetch parent clock's clock-output-name if DT index was set
3572 * This may still fail in some cases, such as when the parent is
3573 * specified directly via a struct clk_hw pointer, but it isn't
3576 parent = clk_core_get_parent_by_index(core, i);
3578 seq_puts(s, parent->name);
3579 } else if (core->parents[i].name) {
3580 seq_puts(s, core->parents[i].name);
3581 } else if (core->parents[i].fw_name) {
3582 seq_printf(s, "<%s>(fw)", core->parents[i].fw_name);
3584 if (core->parents[i].index >= 0)
3585 name = of_clk_get_parent_name(core->of_node, core->parents[i].index);
3592 seq_putc(s, terminator);
3595 static int possible_parents_show(struct seq_file *s, void *data)
3597 struct clk_core *core = s->private;
3600 for (i = 0; i < core->num_parents - 1; i++)
3601 possible_parent_show(s, core, i, ' ');
3603 possible_parent_show(s, core, i, '\n');
3607 DEFINE_SHOW_ATTRIBUTE(possible_parents);
3609 static int current_parent_show(struct seq_file *s, void *data)
3611 struct clk_core *core = s->private;
3614 seq_printf(s, "%s\n", core->parent->name);
3618 DEFINE_SHOW_ATTRIBUTE(current_parent);
3620 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3621 static ssize_t current_parent_write(struct file *file, const char __user *ubuf,
3622 size_t count, loff_t *ppos)
3624 struct seq_file *s = file->private_data;
3625 struct clk_core *core = s->private;
3626 struct clk_core *parent;
3630 err = kstrtou8_from_user(ubuf, count, 0, &idx);
3634 parent = clk_core_get_parent_by_index(core, idx);
3639 err = clk_core_set_parent_nolock(core, parent);
3640 clk_prepare_unlock();
3647 static const struct file_operations current_parent_rw_fops = {
3648 .open = current_parent_open,
3649 .write = current_parent_write,
3651 .llseek = seq_lseek,
3652 .release = single_release,
3656 static int clk_duty_cycle_show(struct seq_file *s, void *data)
3658 struct clk_core *core = s->private;
3659 struct clk_duty *duty = &core->duty;
3661 seq_printf(s, "%u/%u\n", duty->num, duty->den);
3665 DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
3667 static int clk_min_rate_show(struct seq_file *s, void *data)
3669 struct clk_core *core = s->private;
3670 unsigned long min_rate, max_rate;
3673 clk_core_get_boundaries(core, &min_rate, &max_rate);
3674 clk_prepare_unlock();
3675 seq_printf(s, "%lu\n", min_rate);
3679 DEFINE_SHOW_ATTRIBUTE(clk_min_rate);
3681 static int clk_max_rate_show(struct seq_file *s, void *data)
3683 struct clk_core *core = s->private;
3684 unsigned long min_rate, max_rate;
3687 clk_core_get_boundaries(core, &min_rate, &max_rate);
3688 clk_prepare_unlock();
3689 seq_printf(s, "%lu\n", max_rate);
3693 DEFINE_SHOW_ATTRIBUTE(clk_max_rate);
3695 static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
3697 struct dentry *root;
3699 if (!core || !pdentry)
3702 root = debugfs_create_dir(core->name, pdentry);
3703 core->dentry = root;
3705 debugfs_create_file("clk_rate", clk_rate_mode, root, core,
3707 debugfs_create_file("clk_min_rate", 0444, root, core, &clk_min_rate_fops);
3708 debugfs_create_file("clk_max_rate", 0444, root, core, &clk_max_rate_fops);
3709 debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
3710 debugfs_create_file("clk_phase", clk_phase_mode, root, core,
3712 debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
3713 debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
3714 debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
3715 debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
3716 debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
3717 debugfs_create_file("clk_duty_cycle", 0444, root, core,
3718 &clk_duty_cycle_fops);
3719 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3720 debugfs_create_file("clk_prepare_enable", 0644, root, core,
3721 &clk_prepare_enable_fops);
3723 if (core->num_parents > 1)
3724 debugfs_create_file("clk_parent", 0644, root, core,
3725 ¤t_parent_rw_fops);
3728 if (core->num_parents > 0)
3729 debugfs_create_file("clk_parent", 0444, root, core,
3730 ¤t_parent_fops);
3732 if (core->num_parents > 1)
3733 debugfs_create_file("clk_possible_parents", 0444, root, core,
3734 &possible_parents_fops);
3736 if (core->ops->debug_init)
3737 core->ops->debug_init(core->hw, core->dentry);
3741 * clk_debug_register - add a clk node to the debugfs clk directory
3742 * @core: the clk being added to the debugfs clk directory
3744 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
3745 * initialized. Otherwise it bails out early since the debugfs clk directory
3746 * will be created lazily by clk_debug_init as part of a late_initcall.
3748 static void clk_debug_register(struct clk_core *core)
3750 mutex_lock(&clk_debug_lock);
3751 hlist_add_head(&core->debug_node, &clk_debug_list);
3753 clk_debug_create_one(core, rootdir);
3754 mutex_unlock(&clk_debug_lock);
3758 * clk_debug_unregister - remove a clk node from the debugfs clk directory
3759 * @core: the clk being removed from the debugfs clk directory
3761 * Dynamically removes a clk and all its child nodes from the
3762 * debugfs clk directory if clk->dentry points to debugfs created by
3763 * clk_debug_register in __clk_core_init.
3765 static void clk_debug_unregister(struct clk_core *core)
3767 mutex_lock(&clk_debug_lock);
3768 hlist_del_init(&core->debug_node);
3769 debugfs_remove_recursive(core->dentry);
3770 core->dentry = NULL;
3771 mutex_unlock(&clk_debug_lock);
3775 * clk_debug_init - lazily populate the debugfs clk directory
3777 * clks are often initialized very early during boot before memory can be
3778 * dynamically allocated and well before debugfs is setup. This function
3779 * populates the debugfs clk directory once at boot-time when we know that
3780 * debugfs is setup. It should only be called once at boot-time, all other clks
3781 * added dynamically will be done so with clk_debug_register.
3783 static int __init clk_debug_init(void)
3785 struct clk_core *core;
3787 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3789 pr_warn("********************************************************************\n");
3790 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
3792 pr_warn("** WRITEABLE clk DebugFS SUPPORT HAS BEEN ENABLED IN THIS KERNEL **\n");
3794 pr_warn("** This means that this kernel is built to expose clk operations **\n");
3795 pr_warn("** such as parent or rate setting, enabling, disabling, etc. **\n");
3796 pr_warn("** to userspace, which may compromise security on your system. **\n");
3798 pr_warn("** If you see this message and you are not debugging the **\n");
3799 pr_warn("** kernel, report this immediately to your vendor! **\n");
3801 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
3802 pr_warn("********************************************************************\n");
3805 rootdir = debugfs_create_dir("clk", NULL);
3807 debugfs_create_file("clk_summary", 0444, rootdir, &all_lists,
3809 debugfs_create_file("clk_dump", 0444, rootdir, &all_lists,
3811 debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list,
3813 debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list,
3816 mutex_lock(&clk_debug_lock);
3817 hlist_for_each_entry(core, &clk_debug_list, debug_node)
3818 clk_debug_create_one(core, rootdir);
3821 mutex_unlock(&clk_debug_lock);
3825 late_initcall(clk_debug_init);
3827 static inline void clk_debug_register(struct clk_core *core) { }
3828 static inline void clk_debug_unregister(struct clk_core *core)
3833 static void clk_core_reparent_orphans_nolock(void)
3835 struct clk_core *orphan;
3836 struct hlist_node *tmp2;
3839 * walk the list of orphan clocks and reparent any that newly finds a
3842 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
3843 struct clk_core *parent = __clk_init_parent(orphan);
3846 * We need to use __clk_set_parent_before() and _after() to
3847 * properly migrate any prepare/enable count of the orphan
3848 * clock. This is important for CLK_IS_CRITICAL clocks, which
3849 * are enabled during init but might not have a parent yet.
3852 /* update the clk tree topology */
3853 __clk_set_parent_before(orphan, parent);
3854 __clk_set_parent_after(orphan, parent, NULL);
3855 __clk_recalc_accuracies(orphan);
3856 __clk_recalc_rates(orphan, true, 0);
3859 * __clk_init_parent() will set the initial req_rate to
3860 * 0 if the clock doesn't have clk_ops::recalc_rate and
3861 * is an orphan when it's registered.
3863 * 'req_rate' is used by clk_set_rate_range() and
3864 * clk_put() to trigger a clk_set_rate() call whenever
3865 * the boundaries are modified. Let's make sure
3866 * 'req_rate' is set to something non-zero so that
3867 * clk_set_rate_range() doesn't drop the frequency.
3869 orphan->req_rate = orphan->rate;
3875 * __clk_core_init - initialize the data structures in a struct clk_core
3876 * @core: clk_core being initialized
3878 * Initializes the lists in struct clk_core, queries the hardware for the
3879 * parent and rate and sets them both.
3881 static int __clk_core_init(struct clk_core *core)
3884 struct clk_core *parent;
3891 * Set hw->core after grabbing the prepare_lock to synchronize with
3892 * callers of clk_core_fill_parent_index() where we treat hw->core
3893 * being NULL as the clk not being registered yet. This is crucial so
3894 * that clks aren't parented until their parent is fully registered.
3896 core->hw->core = core;
3898 ret = clk_pm_runtime_get(core);
3902 /* check to see if a clock with this name is already registered */
3903 if (clk_core_lookup(core->name)) {
3904 pr_debug("%s: clk %s already initialized\n",
3905 __func__, core->name);
3910 /* check that clk_ops are sane. See Documentation/driver-api/clk.rst */
3911 if (core->ops->set_rate &&
3912 !((core->ops->round_rate || core->ops->determine_rate) &&
3913 core->ops->recalc_rate)) {
3914 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
3915 __func__, core->name);
3920 if (core->ops->set_parent && !core->ops->get_parent) {
3921 pr_err("%s: %s must implement .get_parent & .set_parent\n",
3922 __func__, core->name);
3927 if (core->ops->set_parent && !core->ops->determine_rate) {
3928 pr_err("%s: %s must implement .set_parent & .determine_rate\n",
3929 __func__, core->name);
3934 if (core->num_parents > 1 && !core->ops->get_parent) {
3935 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
3936 __func__, core->name);
3941 if (core->ops->set_rate_and_parent &&
3942 !(core->ops->set_parent && core->ops->set_rate)) {
3943 pr_err("%s: %s must implement .set_parent & .set_rate\n",
3944 __func__, core->name);
3950 * optional platform-specific magic
3952 * The .init callback is not used by any of the basic clock types, but
3953 * exists for weird hardware that must perform initialization magic for
3954 * CCF to get an accurate view of clock for any other callbacks. It may
3955 * also be used needs to perform dynamic allocations. Such allocation
3956 * must be freed in the terminate() callback.
3957 * This callback shall not be used to initialize the parameters state,
3958 * such as rate, parent, etc ...
3960 * If it exist, this callback should called before any other callback of
3963 if (core->ops->init) {
3964 ret = core->ops->init(core->hw);
3969 parent = core->parent = __clk_init_parent(core);
3972 * Populate core->parent if parent has already been clk_core_init'd. If
3973 * parent has not yet been clk_core_init'd then place clk in the orphan
3974 * list. If clk doesn't have any parents then place it in the root
3977 * Every time a new clk is clk_init'd then we walk the list of orphan
3978 * clocks and re-parent any that are children of the clock currently
3982 hlist_add_head(&core->child_node, &parent->children);
3983 core->orphan = parent->orphan;
3984 } else if (!core->num_parents) {
3985 hlist_add_head(&core->child_node, &clk_root_list);
3986 core->orphan = false;
3988 hlist_add_head(&core->child_node, &clk_orphan_list);
3989 core->orphan = true;
3993 * Set clk's accuracy. The preferred method is to use
3994 * .recalc_accuracy. For simple clocks and lazy developers the default
3995 * fallback is to use the parent's accuracy. If a clock doesn't have a
3996 * parent (or is orphaned) then accuracy is set to zero (perfect
3999 if (core->ops->recalc_accuracy)
4000 core->accuracy = core->ops->recalc_accuracy(core->hw,
4001 clk_core_get_accuracy_no_lock(parent));
4003 core->accuracy = parent->accuracy;
4008 * Set clk's phase by clk_core_get_phase() caching the phase.
4009 * Since a phase is by definition relative to its parent, just
4010 * query the current clock phase, or just assume it's in phase.
4012 phase = clk_core_get_phase(core);
4015 pr_warn("%s: Failed to get phase for clk '%s'\n", __func__,
4021 * Set clk's duty cycle.
4023 clk_core_update_duty_cycle_nolock(core);
4026 * Set clk's rate. The preferred method is to use .recalc_rate. For
4027 * simple clocks and lazy developers the default fallback is to use the
4028 * parent's rate. If a clock doesn't have a parent (or is orphaned)
4029 * then rate is set to zero.
4031 if (core->ops->recalc_rate)
4032 rate = core->ops->recalc_rate(core->hw,
4033 clk_core_get_rate_nolock(parent));
4035 rate = parent->rate;
4038 core->rate = core->req_rate = rate;
4041 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
4042 * don't get accidentally disabled when walking the orphan tree and
4043 * reparenting clocks
4045 if (core->flags & CLK_IS_CRITICAL) {
4046 ret = clk_core_prepare(core);
4048 pr_warn("%s: critical clk '%s' failed to prepare\n",
4049 __func__, core->name);
4053 ret = clk_core_enable_lock(core);
4055 pr_warn("%s: critical clk '%s' failed to enable\n",
4056 __func__, core->name);
4057 clk_core_unprepare(core);
4062 clk_core_reparent_orphans_nolock();
4064 clk_pm_runtime_put(core);
4067 hlist_del_init(&core->child_node);
4068 core->hw->core = NULL;
4071 clk_prepare_unlock();
4074 clk_debug_register(core);
4080 * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core
4081 * @core: clk to add consumer to
4082 * @clk: consumer to link to a clk
4084 static void clk_core_link_consumer(struct clk_core *core, struct clk *clk)
4087 hlist_add_head(&clk->clks_node, &core->clks);
4088 clk_prepare_unlock();
4092 * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core
4093 * @clk: consumer to unlink
4095 static void clk_core_unlink_consumer(struct clk *clk)
4097 lockdep_assert_held(&prepare_lock);
4098 hlist_del(&clk->clks_node);
4102 * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core
4103 * @core: clk to allocate a consumer for
4104 * @dev_id: string describing device name
4105 * @con_id: connection ID string on device
4107 * Returns: clk consumer left unlinked from the consumer list
4109 static struct clk *alloc_clk(struct clk_core *core, const char *dev_id,
4114 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
4116 return ERR_PTR(-ENOMEM);
4119 clk->dev_id = dev_id;
4120 clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
4121 clk->max_rate = ULONG_MAX;
4127 * free_clk - Free a clk consumer
4128 * @clk: clk consumer to free
4130 * Note, this assumes the clk has been unlinked from the clk_core consumer
4133 static void free_clk(struct clk *clk)
4135 kfree_const(clk->con_id);
4140 * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given
4142 * @dev: clk consumer device
4143 * @hw: clk_hw associated with the clk being consumed
4144 * @dev_id: string describing device name
4145 * @con_id: connection ID string on device
4147 * This is the main function used to create a clk pointer for use by clk
4148 * consumers. It connects a consumer to the clk_core and clk_hw structures
4149 * used by the framework and clk provider respectively.
4151 struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
4152 const char *dev_id, const char *con_id)
4155 struct clk_core *core;
4157 /* This is to allow this function to be chained to others */
4158 if (IS_ERR_OR_NULL(hw))
4159 return ERR_CAST(hw);
4162 clk = alloc_clk(core, dev_id, con_id);
4167 if (!try_module_get(core->owner)) {
4169 return ERR_PTR(-ENOENT);
4172 kref_get(&core->ref);
4173 clk_core_link_consumer(core, clk);
4179 * clk_hw_get_clk - get clk consumer given an clk_hw
4180 * @hw: clk_hw associated with the clk being consumed
4181 * @con_id: connection ID string on device
4183 * Returns: new clk consumer
4184 * This is the function to be used by providers which need
4185 * to get a consumer clk and act on the clock element
4186 * Calls to this function must be balanced with calls clk_put()
4188 struct clk *clk_hw_get_clk(struct clk_hw *hw, const char *con_id)
4190 struct device *dev = hw->core->dev;
4191 const char *name = dev ? dev_name(dev) : NULL;
4193 return clk_hw_create_clk(dev, hw, name, con_id);
4195 EXPORT_SYMBOL(clk_hw_get_clk);
4197 static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
4207 *dst_p = dst = kstrdup_const(src, GFP_KERNEL);
4214 static int clk_core_populate_parent_map(struct clk_core *core,
4215 const struct clk_init_data *init)
4217 u8 num_parents = init->num_parents;
4218 const char * const *parent_names = init->parent_names;
4219 const struct clk_hw **parent_hws = init->parent_hws;
4220 const struct clk_parent_data *parent_data = init->parent_data;
4222 struct clk_parent_map *parents, *parent;
4228 * Avoid unnecessary string look-ups of clk_core's possible parents by
4229 * having a cache of names/clk_hw pointers to clk_core pointers.
4231 parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
4232 core->parents = parents;
4236 /* Copy everything over because it might be __initdata */
4237 for (i = 0, parent = parents; i < num_parents; i++, parent++) {
4240 /* throw a WARN if any entries are NULL */
4241 WARN(!parent_names[i],
4242 "%s: invalid NULL in %s's .parent_names\n",
4243 __func__, core->name);
4244 ret = clk_cpy_name(&parent->name, parent_names[i],
4246 } else if (parent_data) {
4247 parent->hw = parent_data[i].hw;
4248 parent->index = parent_data[i].index;
4249 ret = clk_cpy_name(&parent->fw_name,
4250 parent_data[i].fw_name, false);
4252 ret = clk_cpy_name(&parent->name,
4253 parent_data[i].name,
4255 } else if (parent_hws) {
4256 parent->hw = parent_hws[i];
4259 WARN(1, "Must specify parents if num_parents > 0\n");
4264 kfree_const(parents[i].name);
4265 kfree_const(parents[i].fw_name);
4276 static void clk_core_free_parent_map(struct clk_core *core)
4278 int i = core->num_parents;
4280 if (!core->num_parents)
4284 kfree_const(core->parents[i].name);
4285 kfree_const(core->parents[i].fw_name);
4288 kfree(core->parents);
4291 /* Free memory allocated for a struct clk_core */
4292 static void __clk_release(struct kref *ref)
4294 struct clk_core *core = container_of(ref, struct clk_core, ref);
4296 if (core->rpm_enabled) {
4297 mutex_lock(&clk_rpm_list_lock);
4298 hlist_del(&core->rpm_node);
4299 mutex_unlock(&clk_rpm_list_lock);
4302 clk_core_free_parent_map(core);
4303 kfree_const(core->name);
4308 __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
4311 struct clk_core *core;
4312 const struct clk_init_data *init = hw->init;
4315 * The init data is not supposed to be used outside of registration path.
4316 * Set it to NULL so that provider drivers can't use it either and so that
4317 * we catch use of hw->init early on in the core.
4321 core = kzalloc(sizeof(*core), GFP_KERNEL);
4327 kref_init(&core->ref);
4329 core->name = kstrdup_const(init->name, GFP_KERNEL);
4335 if (WARN_ON(!init->ops)) {
4339 core->ops = init->ops;
4342 clk_pm_runtime_init(core);
4344 if (dev && dev->driver)
4345 core->owner = dev->driver->owner;
4347 core->flags = init->flags;
4348 core->num_parents = init->num_parents;
4350 core->max_rate = ULONG_MAX;
4352 ret = clk_core_populate_parent_map(core, init);
4356 INIT_HLIST_HEAD(&core->clks);
4359 * Don't call clk_hw_create_clk() here because that would pin the
4360 * provider module to itself and prevent it from ever being removed.
4362 hw->clk = alloc_clk(core, NULL, NULL);
4363 if (IS_ERR(hw->clk)) {
4364 ret = PTR_ERR(hw->clk);
4365 goto fail_create_clk;
4368 clk_core_link_consumer(core, hw->clk);
4370 ret = __clk_core_init(core);
4375 clk_core_unlink_consumer(hw->clk);
4376 clk_prepare_unlock();
4385 kref_put(&core->ref, __clk_release);
4387 return ERR_PTR(ret);
4391 * dev_or_parent_of_node() - Get device node of @dev or @dev's parent
4392 * @dev: Device to get device node of
4394 * Return: device node pointer of @dev, or the device node pointer of
4395 * @dev->parent if dev doesn't have a device node, or NULL if neither
4396 * @dev or @dev->parent have a device node.
4398 static struct device_node *dev_or_parent_of_node(struct device *dev)
4400 struct device_node *np;
4405 np = dev_of_node(dev);
4407 np = dev_of_node(dev->parent);
4413 * clk_register - allocate a new clock, register it and return an opaque cookie
4414 * @dev: device that is registering this clock
4415 * @hw: link to hardware-specific clock data
4417 * clk_register is the *deprecated* interface for populating the clock tree with
4418 * new clock nodes. Use clk_hw_register() instead.
4420 * Returns: a pointer to the newly allocated struct clk which
4421 * cannot be dereferenced by driver code but may be used in conjunction with the
4422 * rest of the clock API. In the event of an error clk_register will return an
4423 * error code; drivers must test for an error code after calling clk_register.
4425 struct clk *clk_register(struct device *dev, struct clk_hw *hw)
4427 return __clk_register(dev, dev_or_parent_of_node(dev), hw);
4429 EXPORT_SYMBOL_GPL(clk_register);
4432 * clk_hw_register - register a clk_hw and return an error code
4433 * @dev: device that is registering this clock
4434 * @hw: link to hardware-specific clock data
4436 * clk_hw_register is the primary interface for populating the clock tree with
4437 * new clock nodes. It returns an integer equal to zero indicating success or
4438 * less than zero indicating failure. Drivers must test for an error code after
4439 * calling clk_hw_register().
4441 int clk_hw_register(struct device *dev, struct clk_hw *hw)
4443 return PTR_ERR_OR_ZERO(__clk_register(dev, dev_or_parent_of_node(dev),
4446 EXPORT_SYMBOL_GPL(clk_hw_register);
4449 * of_clk_hw_register - register a clk_hw and return an error code
4450 * @node: device_node of device that is registering this clock
4451 * @hw: link to hardware-specific clock data
4453 * of_clk_hw_register() is the primary interface for populating the clock tree
4454 * with new clock nodes when a struct device is not available, but a struct
4455 * device_node is. It returns an integer equal to zero indicating success or
4456 * less than zero indicating failure. Drivers must test for an error code after
4457 * calling of_clk_hw_register().
4459 int of_clk_hw_register(struct device_node *node, struct clk_hw *hw)
4461 return PTR_ERR_OR_ZERO(__clk_register(NULL, node, hw));
4463 EXPORT_SYMBOL_GPL(of_clk_hw_register);
4466 * Empty clk_ops for unregistered clocks. These are used temporarily
4467 * after clk_unregister() was called on a clock and until last clock
4468 * consumer calls clk_put() and the struct clk object is freed.
4470 static int clk_nodrv_prepare_enable(struct clk_hw *hw)
4475 static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
4480 static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
4481 unsigned long parent_rate)
4486 static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
4491 static int clk_nodrv_determine_rate(struct clk_hw *hw,
4492 struct clk_rate_request *req)
4497 static const struct clk_ops clk_nodrv_ops = {
4498 .enable = clk_nodrv_prepare_enable,
4499 .disable = clk_nodrv_disable_unprepare,
4500 .prepare = clk_nodrv_prepare_enable,
4501 .unprepare = clk_nodrv_disable_unprepare,
4502 .determine_rate = clk_nodrv_determine_rate,
4503 .set_rate = clk_nodrv_set_rate,
4504 .set_parent = clk_nodrv_set_parent,
4507 static void clk_core_evict_parent_cache_subtree(struct clk_core *root,
4508 const struct clk_core *target)
4511 struct clk_core *child;
4513 for (i = 0; i < root->num_parents; i++)
4514 if (root->parents[i].core == target)
4515 root->parents[i].core = NULL;
4517 hlist_for_each_entry(child, &root->children, child_node)
4518 clk_core_evict_parent_cache_subtree(child, target);
4521 /* Remove this clk from all parent caches */
4522 static void clk_core_evict_parent_cache(struct clk_core *core)
4524 const struct hlist_head **lists;
4525 struct clk_core *root;
4527 lockdep_assert_held(&prepare_lock);
4529 for (lists = all_lists; *lists; lists++)
4530 hlist_for_each_entry(root, *lists, child_node)
4531 clk_core_evict_parent_cache_subtree(root, core);
4536 * clk_unregister - unregister a currently registered clock
4537 * @clk: clock to unregister
4539 void clk_unregister(struct clk *clk)
4541 unsigned long flags;
4542 const struct clk_ops *ops;
4544 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4547 clk_debug_unregister(clk->core);
4551 ops = clk->core->ops;
4552 if (ops == &clk_nodrv_ops) {
4553 pr_err("%s: unregistered clock: %s\n", __func__,
4558 * Assign empty clock ops for consumers that might still hold
4559 * a reference to this clock.
4561 flags = clk_enable_lock();
4562 clk->core->ops = &clk_nodrv_ops;
4563 clk_enable_unlock(flags);
4566 ops->terminate(clk->core->hw);
4568 if (!hlist_empty(&clk->core->children)) {
4569 struct clk_core *child;
4570 struct hlist_node *t;
4572 /* Reparent all children to the orphan list. */
4573 hlist_for_each_entry_safe(child, t, &clk->core->children,
4575 clk_core_set_parent_nolock(child, NULL);
4578 clk_core_evict_parent_cache(clk->core);
4580 hlist_del_init(&clk->core->child_node);
4582 if (clk->core->prepare_count)
4583 pr_warn("%s: unregistering prepared clock: %s\n",
4584 __func__, clk->core->name);
4586 if (clk->core->protect_count)
4587 pr_warn("%s: unregistering protected clock: %s\n",
4588 __func__, clk->core->name);
4590 kref_put(&clk->core->ref, __clk_release);
4593 clk_prepare_unlock();
4595 EXPORT_SYMBOL_GPL(clk_unregister);
4598 * clk_hw_unregister - unregister a currently registered clk_hw
4599 * @hw: hardware-specific clock data to unregister
4601 void clk_hw_unregister(struct clk_hw *hw)
4603 clk_unregister(hw->clk);
4605 EXPORT_SYMBOL_GPL(clk_hw_unregister);
4607 static void devm_clk_unregister_cb(struct device *dev, void *res)
4609 clk_unregister(*(struct clk **)res);
4612 static void devm_clk_hw_unregister_cb(struct device *dev, void *res)
4614 clk_hw_unregister(*(struct clk_hw **)res);
4618 * devm_clk_register - resource managed clk_register()
4619 * @dev: device that is registering this clock
4620 * @hw: link to hardware-specific clock data
4622 * Managed clk_register(). This function is *deprecated*, use devm_clk_hw_register() instead.
4624 * Clocks returned from this function are automatically clk_unregister()ed on
4625 * driver detach. See clk_register() for more information.
4627 struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
4632 clkp = devres_alloc(devm_clk_unregister_cb, sizeof(*clkp), GFP_KERNEL);
4634 return ERR_PTR(-ENOMEM);
4636 clk = clk_register(dev, hw);
4639 devres_add(dev, clkp);
4646 EXPORT_SYMBOL_GPL(devm_clk_register);
4649 * devm_clk_hw_register - resource managed clk_hw_register()
4650 * @dev: device that is registering this clock
4651 * @hw: link to hardware-specific clock data
4653 * Managed clk_hw_register(). Clocks registered by this function are
4654 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
4655 * for more information.
4657 int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
4659 struct clk_hw **hwp;
4662 hwp = devres_alloc(devm_clk_hw_unregister_cb, sizeof(*hwp), GFP_KERNEL);
4666 ret = clk_hw_register(dev, hw);
4669 devres_add(dev, hwp);
4676 EXPORT_SYMBOL_GPL(devm_clk_hw_register);
4678 static void devm_clk_release(struct device *dev, void *res)
4680 clk_put(*(struct clk **)res);
4684 * devm_clk_hw_get_clk - resource managed clk_hw_get_clk()
4685 * @dev: device that is registering this clock
4686 * @hw: clk_hw associated with the clk being consumed
4687 * @con_id: connection ID string on device
4689 * Managed clk_hw_get_clk(). Clocks got with this function are
4690 * automatically clk_put() on driver detach. See clk_put()
4691 * for more information.
4693 struct clk *devm_clk_hw_get_clk(struct device *dev, struct clk_hw *hw,
4699 /* This should not happen because it would mean we have drivers
4700 * passing around clk_hw pointers instead of having the caller use
4701 * proper clk_get() style APIs
4703 WARN_ON_ONCE(dev != hw->core->dev);
4705 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
4707 return ERR_PTR(-ENOMEM);
4709 clk = clk_hw_get_clk(hw, con_id);
4712 devres_add(dev, clkp);
4719 EXPORT_SYMBOL_GPL(devm_clk_hw_get_clk);
4725 void __clk_put(struct clk *clk)
4727 struct module *owner;
4729 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4735 * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
4736 * given user should be balanced with calls to clk_rate_exclusive_put()
4737 * and by that same consumer
4739 if (WARN_ON(clk->exclusive_count)) {
4740 /* We voiced our concern, let's sanitize the situation */
4741 clk->core->protect_count -= (clk->exclusive_count - 1);
4742 clk_core_rate_unprotect(clk->core);
4743 clk->exclusive_count = 0;
4746 hlist_del(&clk->clks_node);
4748 /* If we had any boundaries on that clock, let's drop them. */
4749 if (clk->min_rate > 0 || clk->max_rate < ULONG_MAX)
4750 clk_set_rate_range_nolock(clk, 0, ULONG_MAX);
4752 owner = clk->core->owner;
4753 kref_put(&clk->core->ref, __clk_release);
4755 clk_prepare_unlock();
4762 /*** clk rate change notifiers ***/
4765 * clk_notifier_register - add a clk rate change notifier
4766 * @clk: struct clk * to watch
4767 * @nb: struct notifier_block * with callback info
4769 * Request notification when clk's rate changes. This uses an SRCU
4770 * notifier because we want it to block and notifier unregistrations are
4771 * uncommon. The callbacks associated with the notifier must not
4772 * re-enter into the clk framework by calling any top-level clk APIs;
4773 * this will cause a nested prepare_lock mutex.
4775 * In all notification cases (pre, post and abort rate change) the original
4776 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
4777 * and the new frequency is passed via struct clk_notifier_data.new_rate.
4779 * clk_notifier_register() must be called from non-atomic context.
4780 * Returns -EINVAL if called with null arguments, -ENOMEM upon
4781 * allocation failure; otherwise, passes along the return value of
4782 * srcu_notifier_chain_register().
4784 int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
4786 struct clk_notifier *cn;
4794 /* search the list of notifiers for this clk */
4795 list_for_each_entry(cn, &clk_notifier_list, node)
4799 /* if clk wasn't in the notifier list, allocate new clk_notifier */
4800 cn = kzalloc(sizeof(*cn), GFP_KERNEL);
4805 srcu_init_notifier_head(&cn->notifier_head);
4807 list_add(&cn->node, &clk_notifier_list);
4810 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
4812 clk->core->notifier_count++;
4815 clk_prepare_unlock();
4819 EXPORT_SYMBOL_GPL(clk_notifier_register);
4822 * clk_notifier_unregister - remove a clk rate change notifier
4823 * @clk: struct clk *
4824 * @nb: struct notifier_block * with callback info
4826 * Request no further notification for changes to 'clk' and frees memory
4827 * allocated in clk_notifier_register.
4829 * Returns -EINVAL if called with null arguments; otherwise, passes
4830 * along the return value of srcu_notifier_chain_unregister().
4832 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
4834 struct clk_notifier *cn;
4842 list_for_each_entry(cn, &clk_notifier_list, node) {
4843 if (cn->clk == clk) {
4844 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
4846 clk->core->notifier_count--;
4848 /* XXX the notifier code should handle this better */
4849 if (!cn->notifier_head.head) {
4850 srcu_cleanup_notifier_head(&cn->notifier_head);
4851 list_del(&cn->node);
4858 clk_prepare_unlock();
4862 EXPORT_SYMBOL_GPL(clk_notifier_unregister);
4864 struct clk_notifier_devres {
4866 struct notifier_block *nb;
4869 static void devm_clk_notifier_release(struct device *dev, void *res)
4871 struct clk_notifier_devres *devres = res;
4873 clk_notifier_unregister(devres->clk, devres->nb);
4876 int devm_clk_notifier_register(struct device *dev, struct clk *clk,
4877 struct notifier_block *nb)
4879 struct clk_notifier_devres *devres;
4882 devres = devres_alloc(devm_clk_notifier_release,
4883 sizeof(*devres), GFP_KERNEL);
4888 ret = clk_notifier_register(clk, nb);
4892 devres_add(dev, devres);
4894 devres_free(devres);
4899 EXPORT_SYMBOL_GPL(devm_clk_notifier_register);
4902 static void clk_core_reparent_orphans(void)
4905 clk_core_reparent_orphans_nolock();
4906 clk_prepare_unlock();
4910 * struct of_clk_provider - Clock provider registration structure
4911 * @link: Entry in global list of clock providers
4912 * @node: Pointer to device tree node of clock provider
4913 * @get: Get clock callback. Returns NULL or a struct clk for the
4914 * given clock specifier
4915 * @get_hw: Get clk_hw callback. Returns NULL, ERR_PTR or a
4916 * struct clk_hw for the given clock specifier
4917 * @data: context pointer to be passed into @get callback
4919 struct of_clk_provider {
4920 struct list_head link;
4922 struct device_node *node;
4923 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
4924 struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
4928 extern struct of_device_id __clk_of_table;
4929 static const struct of_device_id __clk_of_table_sentinel
4930 __used __section("__clk_of_table_end");
4932 static LIST_HEAD(of_clk_providers);
4933 static DEFINE_MUTEX(of_clk_mutex);
4935 struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
4940 EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
4942 struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
4946 EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
4948 struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
4950 struct clk_onecell_data *clk_data = data;
4951 unsigned int idx = clkspec->args[0];
4953 if (idx >= clk_data->clk_num) {
4954 pr_err("%s: invalid clock index %u\n", __func__, idx);
4955 return ERR_PTR(-EINVAL);
4958 return clk_data->clks[idx];
4960 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
4963 of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
4965 struct clk_hw_onecell_data *hw_data = data;
4966 unsigned int idx = clkspec->args[0];
4968 if (idx >= hw_data->num) {
4969 pr_err("%s: invalid index %u\n", __func__, idx);
4970 return ERR_PTR(-EINVAL);
4973 return hw_data->hws[idx];
4975 EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
4978 * of_clk_add_provider() - Register a clock provider for a node
4979 * @np: Device node pointer associated with clock provider
4980 * @clk_src_get: callback for decoding clock
4981 * @data: context pointer for @clk_src_get callback.
4983 * This function is *deprecated*. Use of_clk_add_hw_provider() instead.
4985 int of_clk_add_provider(struct device_node *np,
4986 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
4990 struct of_clk_provider *cp;
4996 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
5000 cp->node = of_node_get(np);
5002 cp->get = clk_src_get;
5004 mutex_lock(&of_clk_mutex);
5005 list_add(&cp->link, &of_clk_providers);
5006 mutex_unlock(&of_clk_mutex);
5007 pr_debug("Added clock from %pOF\n", np);
5009 clk_core_reparent_orphans();
5011 ret = of_clk_set_defaults(np, true);
5013 of_clk_del_provider(np);
5015 fwnode_dev_initialized(&np->fwnode, true);
5019 EXPORT_SYMBOL_GPL(of_clk_add_provider);
5022 * of_clk_add_hw_provider() - Register a clock provider for a node
5023 * @np: Device node pointer associated with clock provider
5024 * @get: callback for decoding clk_hw
5025 * @data: context pointer for @get callback.
5027 int of_clk_add_hw_provider(struct device_node *np,
5028 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
5032 struct of_clk_provider *cp;
5038 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
5042 cp->node = of_node_get(np);
5046 mutex_lock(&of_clk_mutex);
5047 list_add(&cp->link, &of_clk_providers);
5048 mutex_unlock(&of_clk_mutex);
5049 pr_debug("Added clk_hw provider from %pOF\n", np);
5051 clk_core_reparent_orphans();
5053 ret = of_clk_set_defaults(np, true);
5055 of_clk_del_provider(np);
5057 fwnode_dev_initialized(&np->fwnode, true);
5061 EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
5063 static void devm_of_clk_release_provider(struct device *dev, void *res)
5065 of_clk_del_provider(*(struct device_node **)res);
5069 * We allow a child device to use its parent device as the clock provider node
5070 * for cases like MFD sub-devices where the child device driver wants to use
5071 * devm_*() APIs but not list the device in DT as a sub-node.
5073 static struct device_node *get_clk_provider_node(struct device *dev)
5075 struct device_node *np, *parent_np;
5078 parent_np = dev->parent ? dev->parent->of_node : NULL;
5080 if (!of_property_present(np, "#clock-cells"))
5081 if (of_property_present(parent_np, "#clock-cells"))
5088 * devm_of_clk_add_hw_provider() - Managed clk provider node registration
5089 * @dev: Device acting as the clock provider (used for DT node and lifetime)
5090 * @get: callback for decoding clk_hw
5091 * @data: context pointer for @get callback
5093 * Registers clock provider for given device's node. If the device has no DT
5094 * node or if the device node lacks of clock provider information (#clock-cells)
5095 * then the parent device's node is scanned for this information. If parent node
5096 * has the #clock-cells then it is used in registration. Provider is
5097 * automatically released at device exit.
5099 * Return: 0 on success or an errno on failure.
5101 int devm_of_clk_add_hw_provider(struct device *dev,
5102 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
5106 struct device_node **ptr, *np;
5109 ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
5114 np = get_clk_provider_node(dev);
5115 ret = of_clk_add_hw_provider(np, get, data);
5118 devres_add(dev, ptr);
5125 EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);
5128 * of_clk_del_provider() - Remove a previously registered clock provider
5129 * @np: Device node pointer associated with clock provider
5131 void of_clk_del_provider(struct device_node *np)
5133 struct of_clk_provider *cp;
5138 mutex_lock(&of_clk_mutex);
5139 list_for_each_entry(cp, &of_clk_providers, link) {
5140 if (cp->node == np) {
5141 list_del(&cp->link);
5142 fwnode_dev_initialized(&np->fwnode, false);
5143 of_node_put(cp->node);
5148 mutex_unlock(&of_clk_mutex);
5150 EXPORT_SYMBOL_GPL(of_clk_del_provider);
5153 * of_parse_clkspec() - Parse a DT clock specifier for a given device node
5154 * @np: device node to parse clock specifier from
5155 * @index: index of phandle to parse clock out of. If index < 0, @name is used
5156 * @name: clock name to find and parse. If name is NULL, the index is used
5157 * @out_args: Result of parsing the clock specifier
5159 * Parses a device node's "clocks" and "clock-names" properties to find the
5160 * phandle and cells for the index or name that is desired. The resulting clock
5161 * specifier is placed into @out_args, or an errno is returned when there's a
5162 * parsing error. The @index argument is ignored if @name is non-NULL.
5166 * phandle1: clock-controller@1 {
5167 * #clock-cells = <2>;
5170 * phandle2: clock-controller@2 {
5171 * #clock-cells = <1>;
5174 * clock-consumer@3 {
5175 * clocks = <&phandle1 1 2 &phandle2 3>;
5176 * clock-names = "name1", "name2";
5179 * To get a device_node for `clock-controller@2' node you may call this
5180 * function a few different ways:
5182 * of_parse_clkspec(clock-consumer@3, -1, "name2", &args);
5183 * of_parse_clkspec(clock-consumer@3, 1, NULL, &args);
5184 * of_parse_clkspec(clock-consumer@3, 1, "name2", &args);
5186 * Return: 0 upon successfully parsing the clock specifier. Otherwise, -ENOENT
5187 * if @name is NULL or -EINVAL if @name is non-NULL and it can't be found in
5188 * the "clock-names" property of @np.
5190 static int of_parse_clkspec(const struct device_node *np, int index,
5191 const char *name, struct of_phandle_args *out_args)
5195 /* Walk up the tree of devices looking for a clock property that matches */
5198 * For named clocks, first look up the name in the
5199 * "clock-names" property. If it cannot be found, then index
5200 * will be an error code and of_parse_phandle_with_args() will
5204 index = of_property_match_string(np, "clock-names", name);
5205 ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells",
5209 if (name && index >= 0)
5213 * No matching clock found on this node. If the parent node
5214 * has a "clock-ranges" property, then we can try one of its
5218 if (np && !of_get_property(np, "clock-ranges", NULL))
5226 static struct clk_hw *
5227 __of_clk_get_hw_from_provider(struct of_clk_provider *provider,
5228 struct of_phandle_args *clkspec)
5232 if (provider->get_hw)
5233 return provider->get_hw(clkspec, provider->data);
5235 clk = provider->get(clkspec, provider->data);
5237 return ERR_CAST(clk);
5238 return __clk_get_hw(clk);
5241 static struct clk_hw *
5242 of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
5244 struct of_clk_provider *provider;
5245 struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER);
5248 return ERR_PTR(-EINVAL);
5250 mutex_lock(&of_clk_mutex);
5251 list_for_each_entry(provider, &of_clk_providers, link) {
5252 if (provider->node == clkspec->np) {
5253 hw = __of_clk_get_hw_from_provider(provider, clkspec);
5258 mutex_unlock(&of_clk_mutex);
5264 * of_clk_get_from_provider() - Lookup a clock from a clock provider
5265 * @clkspec: pointer to a clock specifier data structure
5267 * This function looks up a struct clk from the registered list of clock
5268 * providers, an input is a clock specifier data structure as returned
5269 * from the of_parse_phandle_with_args() function call.
5271 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
5273 struct clk_hw *hw = of_clk_get_hw_from_clkspec(clkspec);
5275 return clk_hw_create_clk(NULL, hw, NULL, __func__);
5277 EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
5279 struct clk_hw *of_clk_get_hw(struct device_node *np, int index,
5284 struct of_phandle_args clkspec;
5286 ret = of_parse_clkspec(np, index, con_id, &clkspec);
5288 return ERR_PTR(ret);
5290 hw = of_clk_get_hw_from_clkspec(&clkspec);
5291 of_node_put(clkspec.np);
5296 static struct clk *__of_clk_get(struct device_node *np,
5297 int index, const char *dev_id,
5300 struct clk_hw *hw = of_clk_get_hw(np, index, con_id);
5302 return clk_hw_create_clk(NULL, hw, dev_id, con_id);
5305 struct clk *of_clk_get(struct device_node *np, int index)
5307 return __of_clk_get(np, index, np->full_name, NULL);
5309 EXPORT_SYMBOL(of_clk_get);
5312 * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
5313 * @np: pointer to clock consumer node
5314 * @name: name of consumer's clock input, or NULL for the first clock reference
5316 * This function parses the clocks and clock-names properties,
5317 * and uses them to look up the struct clk from the registered list of clock
5320 struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
5323 return ERR_PTR(-ENOENT);
5325 return __of_clk_get(np, 0, np->full_name, name);
5327 EXPORT_SYMBOL(of_clk_get_by_name);
5330 * of_clk_get_parent_count() - Count the number of clocks a device node has
5331 * @np: device node to count
5333 * Returns: The number of clocks that are possible parents of this node
5335 unsigned int of_clk_get_parent_count(const struct device_node *np)
5339 count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
5345 EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
5347 const char *of_clk_get_parent_name(const struct device_node *np, int index)
5349 struct of_phandle_args clkspec;
5350 struct property *prop;
5351 const char *clk_name;
5358 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
5363 index = clkspec.args_count ? clkspec.args[0] : 0;
5366 /* if there is an indices property, use it to transfer the index
5367 * specified into an array offset for the clock-output-names property.
5369 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
5376 /* We went off the end of 'clock-indices' without finding it */
5380 if (of_property_read_string_index(clkspec.np, "clock-output-names",
5384 * Best effort to get the name if the clock has been
5385 * registered with the framework. If the clock isn't
5386 * registered, we return the node name as the name of
5387 * the clock as long as #clock-cells = 0.
5389 clk = of_clk_get_from_provider(&clkspec);
5391 if (clkspec.args_count == 0)
5392 clk_name = clkspec.np->name;
5396 clk_name = __clk_get_name(clk);
5402 of_node_put(clkspec.np);
5405 EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
5408 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
5410 * @np: Device node pointer associated with clock provider
5411 * @parents: pointer to char array that hold the parents' names
5412 * @size: size of the @parents array
5414 * Return: number of parents for the clock node.
5416 int of_clk_parent_fill(struct device_node *np, const char **parents,
5421 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
5426 EXPORT_SYMBOL_GPL(of_clk_parent_fill);
5428 struct clock_provider {
5429 void (*clk_init_cb)(struct device_node *);
5430 struct device_node *np;
5431 struct list_head node;
5435 * This function looks for a parent clock. If there is one, then it
5436 * checks that the provider for this parent clock was initialized, in
5437 * this case the parent clock will be ready.
5439 static int parent_ready(struct device_node *np)
5444 struct clk *clk = of_clk_get(np, i);
5446 /* this parent is ready we can check the next one */
5453 /* at least one parent is not ready, we exit now */
5454 if (PTR_ERR(clk) == -EPROBE_DEFER)
5458 * Here we make assumption that the device tree is
5459 * written correctly. So an error means that there is
5460 * no more parent. As we didn't exit yet, then the
5461 * previous parent are ready. If there is no clock
5462 * parent, no need to wait for them, then we can
5463 * consider their absence as being ready
5470 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
5471 * @np: Device node pointer associated with clock provider
5472 * @index: clock index
5473 * @flags: pointer to top-level framework flags
5475 * Detects if the clock-critical property exists and, if so, sets the
5476 * corresponding CLK_IS_CRITICAL flag.
5478 * Do not use this function. It exists only for legacy Device Tree
5479 * bindings, such as the one-clock-per-node style that are outdated.
5480 * Those bindings typically put all clock data into .dts and the Linux
5481 * driver has no clock data, thus making it impossible to set this flag
5482 * correctly from the driver. Only those drivers may call
5483 * of_clk_detect_critical from their setup functions.
5485 * Return: error code or zero on success
5487 int of_clk_detect_critical(struct device_node *np, int index,
5488 unsigned long *flags)
5490 struct property *prop;
5497 of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
5499 *flags |= CLK_IS_CRITICAL;
5505 * of_clk_init() - Scan and init clock providers from the DT
5506 * @matches: array of compatible values and init functions for providers.
5508 * This function scans the device tree for matching clock providers
5509 * and calls their initialization functions. It also does it by trying
5510 * to follow the dependencies.
5512 void __init of_clk_init(const struct of_device_id *matches)
5514 const struct of_device_id *match;
5515 struct device_node *np;
5516 struct clock_provider *clk_provider, *next;
5519 LIST_HEAD(clk_provider_list);
5522 matches = &__clk_of_table;
5524 /* First prepare the list of the clocks providers */
5525 for_each_matching_node_and_match(np, matches, &match) {
5526 struct clock_provider *parent;
5528 if (!of_device_is_available(np))
5531 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
5533 list_for_each_entry_safe(clk_provider, next,
5534 &clk_provider_list, node) {
5535 list_del(&clk_provider->node);
5536 of_node_put(clk_provider->np);
5537 kfree(clk_provider);
5543 parent->clk_init_cb = match->data;
5544 parent->np = of_node_get(np);
5545 list_add_tail(&parent->node, &clk_provider_list);
5548 while (!list_empty(&clk_provider_list)) {
5549 is_init_done = false;
5550 list_for_each_entry_safe(clk_provider, next,
5551 &clk_provider_list, node) {
5552 if (force || parent_ready(clk_provider->np)) {
5554 /* Don't populate platform devices */
5555 of_node_set_flag(clk_provider->np,
5558 clk_provider->clk_init_cb(clk_provider->np);
5559 of_clk_set_defaults(clk_provider->np, true);
5561 list_del(&clk_provider->node);
5562 of_node_put(clk_provider->np);
5563 kfree(clk_provider);
5564 is_init_done = true;
5569 * We didn't manage to initialize any of the
5570 * remaining providers during the last loop, so now we
5571 * initialize all the remaining ones unconditionally
5572 * in case the clock parent was not mandatory