1 /* SPDX-License-Identifier: GPL-2.0-only */
3 * linux/include/linux/clk.h
5 * Copyright (C) 2004 ARM Limited.
6 * Written by Deep Blue Solutions Limited.
7 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
12 #include <linux/err.h>
13 #include <linux/kernel.h>
14 #include <linux/notifier.h>
19 struct of_phandle_args;
22 * DOC: clk notifier callback types
24 * PRE_RATE_CHANGE - called immediately before the clk rate is changed,
25 * to indicate that the rate change will proceed. Drivers must
26 * immediately terminate any operations that will be affected by the
27 * rate change. Callbacks may either return NOTIFY_DONE, NOTIFY_OK,
28 * NOTIFY_STOP or NOTIFY_BAD.
30 * ABORT_RATE_CHANGE: called if the rate change failed for some reason
31 * after PRE_RATE_CHANGE. In this case, all registered notifiers on
32 * the clk will be called with ABORT_RATE_CHANGE. Callbacks must
33 * always return NOTIFY_DONE or NOTIFY_OK.
35 * POST_RATE_CHANGE - called after the clk rate change has successfully
36 * completed. Callbacks must always return NOTIFY_DONE or NOTIFY_OK.
39 #define PRE_RATE_CHANGE BIT(0)
40 #define POST_RATE_CHANGE BIT(1)
41 #define ABORT_RATE_CHANGE BIT(2)
44 * struct clk_notifier - associate a clk with a notifier
45 * @clk: struct clk * to associate the notifier with
46 * @notifier_head: a blocking_notifier_head for this clk
47 * @node: linked list pointers
49 * A list of struct clk_notifier is maintained by the notifier code.
50 * An entry is created whenever code registers the first notifier on a
51 * particular @clk. Future notifiers on that @clk are added to the
56 struct srcu_notifier_head notifier_head;
57 struct list_head node;
61 * struct clk_notifier_data - rate data to pass to the notifier callback
62 * @clk: struct clk * being changed
63 * @old_rate: previous rate of this clk
64 * @new_rate: new rate of this clk
66 * For a pre-notifier, old_rate is the clk's rate before this rate
67 * change, and new_rate is what the rate will be in the future. For a
68 * post-notifier, old_rate and new_rate are both set to the clk's
69 * current rate (this was done to optimize the implementation).
71 struct clk_notifier_data {
73 unsigned long old_rate;
74 unsigned long new_rate;
78 * struct clk_bulk_data - Data used for bulk clk operations.
80 * @id: clock consumer ID
81 * @clk: struct clk * to store the associated clock
83 * The CLK APIs provide a series of clk_bulk_() API calls as
84 * a convenience to consumers which require multiple clks. This
85 * structure is used to manage data for these calls.
87 struct clk_bulk_data {
92 #ifdef CONFIG_COMMON_CLK
95 * clk_notifier_register: register a clock rate-change notifier callback
96 * @clk: clock whose rate we are interested in
97 * @nb: notifier block with callback function pointer
99 * ProTip: debugging across notifier chains can be frustrating. Make sure that
100 * your notifier callback function prints a nice big warning in case of
103 int clk_notifier_register(struct clk *clk, struct notifier_block *nb);
106 * clk_notifier_unregister: unregister a clock rate-change notifier callback
107 * @clk: clock whose rate we are no longer interested in
108 * @nb: notifier block which will be unregistered
110 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb);
113 * devm_clk_notifier_register - register a managed rate-change notifier callback
114 * @dev: device for clock "consumer"
115 * @clk: clock whose rate we are interested in
116 * @nb: notifier block with callback function pointer
118 * Returns 0 on success, -EERROR otherwise
120 int devm_clk_notifier_register(struct device *dev, struct clk *clk,
121 struct notifier_block *nb);
124 * clk_get_accuracy - obtain the clock accuracy in ppb (parts per billion)
125 * for a clock source.
128 * This gets the clock source accuracy expressed in ppb.
129 * A perfect clock returns 0.
131 long clk_get_accuracy(struct clk *clk);
134 * clk_set_phase - adjust the phase shift of a clock signal
135 * @clk: clock signal source
136 * @degrees: number of degrees the signal is shifted
138 * Shifts the phase of a clock signal by the specified degrees. Returns 0 on
139 * success, -EERROR otherwise.
141 int clk_set_phase(struct clk *clk, int degrees);
144 * clk_get_phase - return the phase shift of a clock signal
145 * @clk: clock signal source
147 * Returns the phase shift of a clock node in degrees, otherwise returns
150 int clk_get_phase(struct clk *clk);
153 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
154 * @clk: clock signal source
155 * @num: numerator of the duty cycle ratio to be applied
156 * @den: denominator of the duty cycle ratio to be applied
158 * Adjust the duty cycle of a clock signal by the specified ratio. Returns 0 on
159 * success, -EERROR otherwise.
161 int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den);
164 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
165 * @clk: clock signal source
166 * @scale: scaling factor to be applied to represent the ratio as an integer
168 * Returns the duty cycle ratio multiplied by the scale provided, otherwise
171 int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale);
174 * clk_is_match - check if two clk's point to the same hardware clock
175 * @p: clk compared against q
176 * @q: clk compared against p
178 * Returns true if the two struct clk pointers both point to the same hardware
179 * clock node. Put differently, returns true if @p and @q
180 * share the same &struct clk_core object.
182 * Returns false otherwise. Note that two NULL clks are treated as matching.
184 bool clk_is_match(const struct clk *p, const struct clk *q);
188 static inline int clk_notifier_register(struct clk *clk,
189 struct notifier_block *nb)
194 static inline int clk_notifier_unregister(struct clk *clk,
195 struct notifier_block *nb)
200 static inline int devm_clk_notifier_register(struct device *dev,
202 struct notifier_block *nb)
207 static inline long clk_get_accuracy(struct clk *clk)
212 static inline long clk_set_phase(struct clk *clk, int phase)
217 static inline long clk_get_phase(struct clk *clk)
222 static inline int clk_set_duty_cycle(struct clk *clk, unsigned int num,
228 static inline unsigned int clk_get_scaled_duty_cycle(struct clk *clk,
234 static inline bool clk_is_match(const struct clk *p, const struct clk *q)
242 * clk_prepare - prepare a clock source
245 * This prepares the clock source for use.
247 * Must not be called from within atomic context.
249 #ifdef CONFIG_HAVE_CLK_PREPARE
250 int clk_prepare(struct clk *clk);
251 int __must_check clk_bulk_prepare(int num_clks,
252 const struct clk_bulk_data *clks);
254 static inline int clk_prepare(struct clk *clk)
260 static inline int __must_check
261 clk_bulk_prepare(int num_clks, const struct clk_bulk_data *clks)
269 * clk_unprepare - undo preparation of a clock source
272 * This undoes a previously prepared clock. The caller must balance
273 * the number of prepare and unprepare calls.
275 * Must not be called from within atomic context.
277 #ifdef CONFIG_HAVE_CLK_PREPARE
278 void clk_unprepare(struct clk *clk);
279 void clk_bulk_unprepare(int num_clks, const struct clk_bulk_data *clks);
281 static inline void clk_unprepare(struct clk *clk)
285 static inline void clk_bulk_unprepare(int num_clks,
286 const struct clk_bulk_data *clks)
292 #ifdef CONFIG_HAVE_CLK
294 * clk_get - lookup and obtain a reference to a clock producer.
295 * @dev: device for clock "consumer"
296 * @id: clock consumer ID
298 * Returns a struct clk corresponding to the clock producer, or
299 * valid IS_ERR() condition containing errno. The implementation
300 * uses @dev and @id to determine the clock consumer, and thereby
301 * the clock producer. (IOW, @id may be identical strings, but
302 * clk_get may return different clock producers depending on @dev.)
304 * Drivers must assume that the clock source is not enabled.
306 * clk_get should not be called from within interrupt context.
308 struct clk *clk_get(struct device *dev, const char *id);
311 * clk_bulk_get - lookup and obtain a number of references to clock producer.
312 * @dev: device for clock "consumer"
313 * @num_clks: the number of clk_bulk_data
314 * @clks: the clk_bulk_data table of consumer
316 * This helper function allows drivers to get several clk consumers in one
317 * operation. If any of the clk cannot be acquired then any clks
318 * that were obtained will be freed before returning to the caller.
320 * Returns 0 if all clocks specified in clk_bulk_data table are obtained
321 * successfully, or valid IS_ERR() condition containing errno.
322 * The implementation uses @dev and @clk_bulk_data.id to determine the
323 * clock consumer, and thereby the clock producer.
324 * The clock returned is stored in each @clk_bulk_data.clk field.
326 * Drivers must assume that the clock source is not enabled.
328 * clk_bulk_get should not be called from within interrupt context.
330 int __must_check clk_bulk_get(struct device *dev, int num_clks,
331 struct clk_bulk_data *clks);
333 * clk_bulk_get_all - lookup and obtain all available references to clock
335 * @dev: device for clock "consumer"
336 * @clks: pointer to the clk_bulk_data table of consumer
338 * This helper function allows drivers to get all clk consumers in one
339 * operation. If any of the clk cannot be acquired then any clks
340 * that were obtained will be freed before returning to the caller.
342 * Returns a positive value for the number of clocks obtained while the
343 * clock references are stored in the clk_bulk_data table in @clks field.
344 * Returns 0 if there're none and a negative value if something failed.
346 * Drivers must assume that the clock source is not enabled.
348 * clk_bulk_get should not be called from within interrupt context.
350 int __must_check clk_bulk_get_all(struct device *dev,
351 struct clk_bulk_data **clks);
354 * clk_bulk_get_optional - lookup and obtain a number of references to clock producer
355 * @dev: device for clock "consumer"
356 * @num_clks: the number of clk_bulk_data
357 * @clks: the clk_bulk_data table of consumer
359 * Behaves the same as clk_bulk_get() except where there is no clock producer.
360 * In this case, instead of returning -ENOENT, the function returns 0 and
361 * NULL for a clk for which a clock producer could not be determined.
363 int __must_check clk_bulk_get_optional(struct device *dev, int num_clks,
364 struct clk_bulk_data *clks);
366 * devm_clk_bulk_get - managed get multiple clk consumers
367 * @dev: device for clock "consumer"
368 * @num_clks: the number of clk_bulk_data
369 * @clks: the clk_bulk_data table of consumer
371 * Return 0 on success, an errno on failure.
373 * This helper function allows drivers to get several clk
374 * consumers in one operation with management, the clks will
375 * automatically be freed when the device is unbound.
377 int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
378 struct clk_bulk_data *clks);
380 * devm_clk_bulk_get_optional - managed get multiple optional consumer clocks
381 * @dev: device for clock "consumer"
382 * @num_clks: the number of clk_bulk_data
383 * @clks: pointer to the clk_bulk_data table of consumer
385 * Behaves the same as devm_clk_bulk_get() except where there is no clock
386 * producer. In this case, instead of returning -ENOENT, the function returns
387 * NULL for given clk. It is assumed all clocks in clk_bulk_data are optional.
389 * Returns 0 if all clocks specified in clk_bulk_data table are obtained
390 * successfully or for any clk there was no clk provider available, otherwise
391 * returns valid IS_ERR() condition containing errno.
392 * The implementation uses @dev and @clk_bulk_data.id to determine the
393 * clock consumer, and thereby the clock producer.
394 * The clock returned is stored in each @clk_bulk_data.clk field.
396 * Drivers must assume that the clock source is not enabled.
398 * clk_bulk_get should not be called from within interrupt context.
400 int __must_check devm_clk_bulk_get_optional(struct device *dev, int num_clks,
401 struct clk_bulk_data *clks);
403 * devm_clk_bulk_get_all - managed get multiple clk consumers
404 * @dev: device for clock "consumer"
405 * @clks: pointer to the clk_bulk_data table of consumer
407 * Returns a positive value for the number of clocks obtained while the
408 * clock references are stored in the clk_bulk_data table in @clks field.
409 * Returns 0 if there're none and a negative value if something failed.
411 * This helper function allows drivers to get several clk
412 * consumers in one operation with management, the clks will
413 * automatically be freed when the device is unbound.
416 int __must_check devm_clk_bulk_get_all(struct device *dev,
417 struct clk_bulk_data **clks);
420 * devm_clk_get - lookup and obtain a managed reference to a clock producer.
421 * @dev: device for clock "consumer"
422 * @id: clock consumer ID
424 * Returns a struct clk corresponding to the clock producer, or
425 * valid IS_ERR() condition containing errno. The implementation
426 * uses @dev and @id to determine the clock consumer, and thereby
427 * the clock producer. (IOW, @id may be identical strings, but
428 * clk_get may return different clock producers depending on @dev.)
430 * Drivers must assume that the clock source is not enabled.
432 * devm_clk_get should not be called from within interrupt context.
434 * The clock will automatically be freed when the device is unbound
437 struct clk *devm_clk_get(struct device *dev, const char *id);
440 * devm_clk_get_optional - lookup and obtain a managed reference to an optional
442 * @dev: device for clock "consumer"
443 * @id: clock consumer ID
445 * Behaves the same as devm_clk_get() except where there is no clock producer.
446 * In this case, instead of returning -ENOENT, the function returns NULL.
448 struct clk *devm_clk_get_optional(struct device *dev, const char *id);
451 * devm_get_clk_from_child - lookup and obtain a managed reference to a
452 * clock producer from child node.
453 * @dev: device for clock "consumer"
454 * @np: pointer to clock consumer node
455 * @con_id: clock consumer ID
457 * This function parses the clocks, and uses them to look up the
458 * struct clk from the registered list of clock providers by using
461 * The clock will automatically be freed when the device is unbound
464 struct clk *devm_get_clk_from_child(struct device *dev,
465 struct device_node *np, const char *con_id);
467 * clk_rate_exclusive_get - get exclusivity over the rate control of a
471 * This function allows drivers to get exclusive control over the rate of a
472 * provider. It prevents any other consumer to execute, even indirectly,
473 * opereation which could alter the rate of the provider or cause glitches
475 * If exlusivity is claimed more than once on clock, even by the same driver,
476 * the rate effectively gets locked as exclusivity can't be preempted.
478 * Must not be called from within atomic context.
480 * Returns success (0) or negative errno.
482 int clk_rate_exclusive_get(struct clk *clk);
485 * clk_rate_exclusive_put - release exclusivity over the rate control of a
489 * This function allows drivers to release the exclusivity it previously got
490 * from clk_rate_exclusive_get()
492 * The caller must balance the number of clk_rate_exclusive_get() and
493 * clk_rate_exclusive_put() calls.
495 * Must not be called from within atomic context.
497 void clk_rate_exclusive_put(struct clk *clk);
500 * clk_enable - inform the system when the clock source should be running.
503 * If the clock can not be enabled/disabled, this should return success.
505 * May be called from atomic contexts.
507 * Returns success (0) or negative errno.
509 int clk_enable(struct clk *clk);
512 * clk_bulk_enable - inform the system when the set of clks should be running.
513 * @num_clks: the number of clk_bulk_data
514 * @clks: the clk_bulk_data table of consumer
516 * May be called from atomic contexts.
518 * Returns success (0) or negative errno.
520 int __must_check clk_bulk_enable(int num_clks,
521 const struct clk_bulk_data *clks);
524 * clk_disable - inform the system when the clock source is no longer required.
527 * Inform the system that a clock source is no longer required by
528 * a driver and may be shut down.
530 * May be called from atomic contexts.
532 * Implementation detail: if the clock source is shared between
533 * multiple drivers, clk_enable() calls must be balanced by the
534 * same number of clk_disable() calls for the clock source to be
537 void clk_disable(struct clk *clk);
540 * clk_bulk_disable - inform the system when the set of clks is no
542 * @num_clks: the number of clk_bulk_data
543 * @clks: the clk_bulk_data table of consumer
545 * Inform the system that a set of clks is no longer required by
546 * a driver and may be shut down.
548 * May be called from atomic contexts.
550 * Implementation detail: if the set of clks is shared between
551 * multiple drivers, clk_bulk_enable() calls must be balanced by the
552 * same number of clk_bulk_disable() calls for the clock source to be
555 void clk_bulk_disable(int num_clks, const struct clk_bulk_data *clks);
558 * clk_get_rate - obtain the current clock rate (in Hz) for a clock source.
559 * This is only valid once the clock source has been enabled.
562 unsigned long clk_get_rate(struct clk *clk);
565 * clk_put - "free" the clock source
568 * Note: drivers must ensure that all clk_enable calls made on this
569 * clock source are balanced by clk_disable calls prior to calling
572 * clk_put should not be called from within interrupt context.
574 void clk_put(struct clk *clk);
577 * clk_bulk_put - "free" the clock source
578 * @num_clks: the number of clk_bulk_data
579 * @clks: the clk_bulk_data table of consumer
581 * Note: drivers must ensure that all clk_bulk_enable calls made on this
582 * clock source are balanced by clk_bulk_disable calls prior to calling
585 * clk_bulk_put should not be called from within interrupt context.
587 void clk_bulk_put(int num_clks, struct clk_bulk_data *clks);
590 * clk_bulk_put_all - "free" all the clock source
591 * @num_clks: the number of clk_bulk_data
592 * @clks: the clk_bulk_data table of consumer
594 * Note: drivers must ensure that all clk_bulk_enable calls made on this
595 * clock source are balanced by clk_bulk_disable calls prior to calling
598 * clk_bulk_put_all should not be called from within interrupt context.
600 void clk_bulk_put_all(int num_clks, struct clk_bulk_data *clks);
603 * devm_clk_put - "free" a managed clock source
604 * @dev: device used to acquire the clock
605 * @clk: clock source acquired with devm_clk_get()
607 * Note: drivers must ensure that all clk_enable calls made on this
608 * clock source are balanced by clk_disable calls prior to calling
611 * clk_put should not be called from within interrupt context.
613 void devm_clk_put(struct device *dev, struct clk *clk);
616 * The remaining APIs are optional for machine class support.
621 * clk_round_rate - adjust a rate to the exact rate a clock can provide
623 * @rate: desired clock rate in Hz
625 * This answers the question "if I were to pass @rate to clk_set_rate(),
626 * what clock rate would I end up with?" without changing the hardware
627 * in any way. In other words:
629 * rate = clk_round_rate(clk, r);
633 * clk_set_rate(clk, r);
634 * rate = clk_get_rate(clk);
636 * are equivalent except the former does not modify the clock hardware
639 * Returns rounded clock rate in Hz, or negative errno.
641 long clk_round_rate(struct clk *clk, unsigned long rate);
644 * clk_set_rate - set the clock rate for a clock source
646 * @rate: desired clock rate in Hz
648 * Updating the rate starts at the top-most affected clock and then
649 * walks the tree down to the bottom-most clock that needs updating.
651 * Returns success (0) or negative errno.
653 int clk_set_rate(struct clk *clk, unsigned long rate);
656 * clk_set_rate_exclusive- set the clock rate and claim exclusivity over
659 * @rate: desired clock rate in Hz
661 * This helper function allows drivers to atomically set the rate of a producer
662 * and claim exclusivity over the rate control of the producer.
664 * It is essentially a combination of clk_set_rate() and
665 * clk_rate_exclusite_get(). Caller must balance this call with a call to
666 * clk_rate_exclusive_put()
668 * Returns success (0) or negative errno.
670 int clk_set_rate_exclusive(struct clk *clk, unsigned long rate);
673 * clk_has_parent - check if a clock is a possible parent for another
675 * @parent: parent clock source
677 * This function can be used in drivers that need to check that a clock can be
678 * the parent of another without actually changing the parent.
680 * Returns true if @parent is a possible parent for @clk, false otherwise.
682 bool clk_has_parent(struct clk *clk, struct clk *parent);
685 * clk_set_rate_range - set a rate range for a clock source
687 * @min: desired minimum clock rate in Hz, inclusive
688 * @max: desired maximum clock rate in Hz, inclusive
690 * Returns success (0) or negative errno.
692 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max);
695 * clk_set_min_rate - set a minimum clock rate for a clock source
697 * @rate: desired minimum clock rate in Hz, inclusive
699 * Returns success (0) or negative errno.
701 int clk_set_min_rate(struct clk *clk, unsigned long rate);
704 * clk_set_max_rate - set a maximum clock rate for a clock source
706 * @rate: desired maximum clock rate in Hz, inclusive
708 * Returns success (0) or negative errno.
710 int clk_set_max_rate(struct clk *clk, unsigned long rate);
713 * clk_set_parent - set the parent clock source for this clock
715 * @parent: parent clock source
717 * Returns success (0) or negative errno.
719 int clk_set_parent(struct clk *clk, struct clk *parent);
722 * clk_get_parent - get the parent clock source for this clock
725 * Returns struct clk corresponding to parent clock source, or
726 * valid IS_ERR() condition containing errno.
728 struct clk *clk_get_parent(struct clk *clk);
731 * clk_get_sys - get a clock based upon the device name
732 * @dev_id: device name
733 * @con_id: connection ID
735 * Returns a struct clk corresponding to the clock producer, or
736 * valid IS_ERR() condition containing errno. The implementation
737 * uses @dev_id and @con_id to determine the clock consumer, and
738 * thereby the clock producer. In contrast to clk_get() this function
739 * takes the device name instead of the device itself for identification.
741 * Drivers must assume that the clock source is not enabled.
743 * clk_get_sys should not be called from within interrupt context.
745 struct clk *clk_get_sys(const char *dev_id, const char *con_id);
748 * clk_save_context - save clock context for poweroff
750 * Saves the context of the clock register for powerstates in which the
751 * contents of the registers will be lost. Occurs deep within the suspend
752 * code so locking is not necessary.
754 int clk_save_context(void);
757 * clk_restore_context - restore clock context after poweroff
759 * This occurs with all clocks enabled. Occurs deep within the resume code
760 * so locking is not necessary.
762 void clk_restore_context(void);
764 #else /* !CONFIG_HAVE_CLK */
766 static inline struct clk *clk_get(struct device *dev, const char *id)
771 static inline int __must_check clk_bulk_get(struct device *dev, int num_clks,
772 struct clk_bulk_data *clks)
777 static inline int __must_check clk_bulk_get_optional(struct device *dev,
778 int num_clks, struct clk_bulk_data *clks)
783 static inline int __must_check clk_bulk_get_all(struct device *dev,
784 struct clk_bulk_data **clks)
789 static inline struct clk *devm_clk_get(struct device *dev, const char *id)
794 static inline struct clk *devm_clk_get_optional(struct device *dev,
800 static inline int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
801 struct clk_bulk_data *clks)
806 static inline int __must_check devm_clk_bulk_get_optional(struct device *dev,
807 int num_clks, struct clk_bulk_data *clks)
812 static inline int __must_check devm_clk_bulk_get_all(struct device *dev,
813 struct clk_bulk_data **clks)
819 static inline struct clk *devm_get_clk_from_child(struct device *dev,
820 struct device_node *np, const char *con_id)
825 static inline void clk_put(struct clk *clk) {}
827 static inline void clk_bulk_put(int num_clks, struct clk_bulk_data *clks) {}
829 static inline void clk_bulk_put_all(int num_clks, struct clk_bulk_data *clks) {}
831 static inline void devm_clk_put(struct device *dev, struct clk *clk) {}
834 static inline int clk_rate_exclusive_get(struct clk *clk)
839 static inline void clk_rate_exclusive_put(struct clk *clk) {}
841 static inline int clk_enable(struct clk *clk)
846 static inline int __must_check clk_bulk_enable(int num_clks,
847 const struct clk_bulk_data *clks)
852 static inline void clk_disable(struct clk *clk) {}
855 static inline void clk_bulk_disable(int num_clks,
856 const struct clk_bulk_data *clks) {}
858 static inline unsigned long clk_get_rate(struct clk *clk)
863 static inline int clk_set_rate(struct clk *clk, unsigned long rate)
868 static inline int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
873 static inline long clk_round_rate(struct clk *clk, unsigned long rate)
878 static inline bool clk_has_parent(struct clk *clk, struct clk *parent)
883 static inline int clk_set_rate_range(struct clk *clk, unsigned long min,
889 static inline int clk_set_min_rate(struct clk *clk, unsigned long rate)
894 static inline int clk_set_max_rate(struct clk *clk, unsigned long rate)
899 static inline int clk_set_parent(struct clk *clk, struct clk *parent)
904 static inline struct clk *clk_get_parent(struct clk *clk)
909 static inline struct clk *clk_get_sys(const char *dev_id, const char *con_id)
914 static inline int clk_save_context(void)
919 static inline void clk_restore_context(void) {}
923 /* clk_prepare_enable helps cases using clk_enable in non-atomic context. */
924 static inline int clk_prepare_enable(struct clk *clk)
928 ret = clk_prepare(clk);
931 ret = clk_enable(clk);
938 /* clk_disable_unprepare helps cases using clk_disable in non-atomic context. */
939 static inline void clk_disable_unprepare(struct clk *clk)
945 static inline int __must_check
946 clk_bulk_prepare_enable(int num_clks, const struct clk_bulk_data *clks)
950 ret = clk_bulk_prepare(num_clks, clks);
953 ret = clk_bulk_enable(num_clks, clks);
955 clk_bulk_unprepare(num_clks, clks);
960 static inline void clk_bulk_disable_unprepare(int num_clks,
961 const struct clk_bulk_data *clks)
963 clk_bulk_disable(num_clks, clks);
964 clk_bulk_unprepare(num_clks, clks);
968 * clk_get_optional - lookup and obtain a reference to an optional clock
970 * @dev: device for clock "consumer"
971 * @id: clock consumer ID
973 * Behaves the same as clk_get() except where there is no clock producer. In
974 * this case, instead of returning -ENOENT, the function returns NULL.
976 static inline struct clk *clk_get_optional(struct device *dev, const char *id)
978 struct clk *clk = clk_get(dev, id);
980 if (clk == ERR_PTR(-ENOENT))
986 #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
987 struct clk *of_clk_get(struct device_node *np, int index);
988 struct clk *of_clk_get_by_name(struct device_node *np, const char *name);
989 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec);
991 static inline struct clk *of_clk_get(struct device_node *np, int index)
993 return ERR_PTR(-ENOENT);
995 static inline struct clk *of_clk_get_by_name(struct device_node *np,
998 return ERR_PTR(-ENOENT);
1000 static inline struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
1002 return ERR_PTR(-ENOENT);