1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * linux/include/linux/clk.h
4 *
5 * Copyright (C) 2004 ARM Limited.
6 * Written by Deep Blue Solutions Limited.
7 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
8 */
9#ifndef __LINUX_CLK_H
10#define __LINUX_CLK_H
11
12#include <linux/err.h>
13#include <linux/kernel.h>
14#include <linux/notifier.h>
15
16struct device;
17struct clk;
18struct device_node;
19struct of_phandle_args;
20
21/**
22 * DOC: clk notifier callback types
23 *
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.
29 *
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.
34 *
35 * POST_RATE_CHANGE - called after the clk rate change has successfully
36 * completed. Callbacks must always return NOTIFY_DONE or NOTIFY_OK.
37 *
38 */
39#define PRE_RATE_CHANGE BIT(0)
40#define POST_RATE_CHANGE BIT(1)
41#define ABORT_RATE_CHANGE BIT(2)
42
43/**
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
48 *
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
52 * @notifier_head.
53 */
54struct clk_notifier {
55 struct clk *clk;
56 struct srcu_notifier_head notifier_head;
57 struct list_head node;
58};
59
60/**
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
65 *
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).
70 */
71struct clk_notifier_data {
72 struct clk *clk;
73 unsigned long old_rate;
74 unsigned long new_rate;
75};
76
77/**
78 * struct clk_bulk_data - Data used for bulk clk operations.
79 *
80 * @id: clock consumer ID
81 * @clk: struct clk * to store the associated clock
82 *
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.
86 */
87struct clk_bulk_data {
88 const char *id;
89 struct clk *clk;
90};
91
92#ifdef CONFIG_COMMON_CLK
93
94/**
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
98 *
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
101 * failure.
102 */
103int clk_notifier_register(struct clk *clk, struct notifier_block *nb);
104
105/**
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
109 */
110int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb);
111
112/**
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
117 *
118 * Returns 0 on success, -EERROR otherwise
119 */
120int devm_clk_notifier_register(struct device *dev, struct clk *clk,
121 struct notifier_block *nb);
122
123/**
124 * clk_get_accuracy - obtain the clock accuracy in ppb (parts per billion)
125 * for a clock source.
126 * @clk: clock source
127 *
128 * This gets the clock source accuracy expressed in ppb.
129 * A perfect clock returns 0.
130 */
131long clk_get_accuracy(struct clk *clk);
132
133/**
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
137 *
138 * Shifts the phase of a clock signal by the specified degrees. Returns 0 on
139 * success, -EERROR otherwise.
140 */
141int clk_set_phase(struct clk *clk, int degrees);
142
143/**
144 * clk_get_phase - return the phase shift of a clock signal
145 * @clk: clock signal source
146 *
147 * Returns the phase shift of a clock node in degrees, otherwise returns
148 * -EERROR.
149 */
150int clk_get_phase(struct clk *clk);
151
152/**
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
157 *
158 * Adjust the duty cycle of a clock signal by the specified ratio. Returns 0 on
159 * success, -EERROR otherwise.
160 */
161int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den);
162
163/**
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
167 *
168 * Returns the duty cycle ratio multiplied by the scale provided, otherwise
169 * returns -EERROR.
170 */
171int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale);
172
173/**
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
177 *
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.
181 *
182 * Returns false otherwise. Note that two NULL clks are treated as matching.
183 */
184bool clk_is_match(const struct clk *p, const struct clk *q);
185
186/**
187 * clk_rate_exclusive_get - get exclusivity over the rate control of a
188 * producer
189 * @clk: clock source
190 *
191 * This function allows drivers to get exclusive control over the rate of a
192 * provider. It prevents any other consumer to execute, even indirectly,
193 * opereation which could alter the rate of the provider or cause glitches
194 *
195 * If exlusivity is claimed more than once on clock, even by the same driver,
196 * the rate effectively gets locked as exclusivity can't be preempted.
197 *
198 * Must not be called from within atomic context.
199 *
200 * Returns success (0) or negative errno.
201 */
202int clk_rate_exclusive_get(struct clk *clk);
203
204/**
205 * clk_rate_exclusive_put - release exclusivity over the rate control of a
206 * producer
207 * @clk: clock source
208 *
209 * This function allows drivers to release the exclusivity it previously got
210 * from clk_rate_exclusive_get()
211 *
212 * The caller must balance the number of clk_rate_exclusive_get() and
213 * clk_rate_exclusive_put() calls.
214 *
215 * Must not be called from within atomic context.
216 */
217void clk_rate_exclusive_put(struct clk *clk);
218
219#else
220
221static inline int clk_notifier_register(struct clk *clk,
222 struct notifier_block *nb)
223{
224 return -ENOTSUPP;
225}
226
227static inline int clk_notifier_unregister(struct clk *clk,
228 struct notifier_block *nb)
229{
230 return -ENOTSUPP;
231}
232
233static inline int devm_clk_notifier_register(struct device *dev,
234 struct clk *clk,
235 struct notifier_block *nb)
236{
237 return -ENOTSUPP;
238}
239
240static inline long clk_get_accuracy(struct clk *clk)
241{
242 return -ENOTSUPP;
243}
244
245static inline long clk_set_phase(struct clk *clk, int phase)
246{
247 return -ENOTSUPP;
248}
249
250static inline long clk_get_phase(struct clk *clk)
251{
252 return -ENOTSUPP;
253}
254
255static inline int clk_set_duty_cycle(struct clk *clk, unsigned int num,
256 unsigned int den)
257{
258 return -ENOTSUPP;
259}
260
261static inline unsigned int clk_get_scaled_duty_cycle(struct clk *clk,
262 unsigned int scale)
263{
264 return 0;
265}
266
267static inline bool clk_is_match(const struct clk *p, const struct clk *q)
268{
269 return p == q;
270}
271
272static inline int clk_rate_exclusive_get(struct clk *clk)
273{
274 return 0;
275}
276
277static inline void clk_rate_exclusive_put(struct clk *clk) {}
278
279#endif
280
281#ifdef CONFIG_HAVE_CLK_PREPARE
282/**
283 * clk_prepare - prepare a clock source
284 * @clk: clock source
285 *
286 * This prepares the clock source for use.
287 *
288 * Must not be called from within atomic context.
289 */
290int clk_prepare(struct clk *clk);
291int __must_check clk_bulk_prepare(int num_clks,
292 const struct clk_bulk_data *clks);
293
294/**
295 * clk_is_enabled_when_prepared - indicate if preparing a clock also enables it.
296 * @clk: clock source
297 *
298 * Returns true if clk_prepare() implicitly enables the clock, effectively
299 * making clk_enable()/clk_disable() no-ops, false otherwise.
300 *
301 * This is of interest mainly to the power management code where actually
302 * disabling the clock also requires unpreparing it to have any material
303 * effect.
304 *
305 * Regardless of the value returned here, the caller must always invoke
306 * clk_enable() or clk_prepare_enable() and counterparts for usage counts
307 * to be right.
308 */
309bool clk_is_enabled_when_prepared(struct clk *clk);
310#else
311static inline int clk_prepare(struct clk *clk)
312{
313 might_sleep();
314 return 0;
315}
316
317static inline int __must_check
318clk_bulk_prepare(int num_clks, const struct clk_bulk_data *clks)
319{
320 might_sleep();
321 return 0;
322}
323
324static inline bool clk_is_enabled_when_prepared(struct clk *clk)
325{
326 return false;
327}
328#endif
329
330/**
331 * clk_unprepare - undo preparation of a clock source
332 * @clk: clock source
333 *
334 * This undoes a previously prepared clock. The caller must balance
335 * the number of prepare and unprepare calls.
336 *
337 * Must not be called from within atomic context.
338 */
339#ifdef CONFIG_HAVE_CLK_PREPARE
340void clk_unprepare(struct clk *clk);
341void clk_bulk_unprepare(int num_clks, const struct clk_bulk_data *clks);
342#else
343static inline void clk_unprepare(struct clk *clk)
344{
345 might_sleep();
346}
347static inline void clk_bulk_unprepare(int num_clks,
348 const struct clk_bulk_data *clks)
349{
350 might_sleep();
351}
352#endif
353
354#ifdef CONFIG_HAVE_CLK
355/**
356 * clk_get - lookup and obtain a reference to a clock producer.
357 * @dev: device for clock "consumer"
358 * @id: clock consumer ID
359 *
360 * Returns a struct clk corresponding to the clock producer, or
361 * valid IS_ERR() condition containing errno. The implementation
362 * uses @dev and @id to determine the clock consumer, and thereby
363 * the clock producer. (IOW, @id may be identical strings, but
364 * clk_get may return different clock producers depending on @dev.)
365 *
366 * Drivers must assume that the clock source is not enabled.
367 *
368 * clk_get should not be called from within interrupt context.
369 */
370struct clk *clk_get(struct device *dev, const char *id);
371
372/**
373 * clk_bulk_get - lookup and obtain a number of references to clock producer.
374 * @dev: device for clock "consumer"
375 * @num_clks: the number of clk_bulk_data
376 * @clks: the clk_bulk_data table of consumer
377 *
378 * This helper function allows drivers to get several clk consumers in one
379 * operation. If any of the clk cannot be acquired then any clks
380 * that were obtained will be freed before returning to the caller.
381 *
382 * Returns 0 if all clocks specified in clk_bulk_data table are obtained
383 * successfully, or valid IS_ERR() condition containing errno.
384 * The implementation uses @dev and @clk_bulk_data.id to determine the
385 * clock consumer, and thereby the clock producer.
386 * The clock returned is stored in each @clk_bulk_data.clk field.
387 *
388 * Drivers must assume that the clock source is not enabled.
389 *
390 * clk_bulk_get should not be called from within interrupt context.
391 */
392int __must_check clk_bulk_get(struct device *dev, int num_clks,
393 struct clk_bulk_data *clks);
394/**
395 * clk_bulk_get_all - lookup and obtain all available references to clock
396 * producer.
397 * @dev: device for clock "consumer"
398 * @clks: pointer to the clk_bulk_data table of consumer
399 *
400 * This helper function allows drivers to get all clk consumers in one
401 * operation. If any of the clk cannot be acquired then any clks
402 * that were obtained will be freed before returning to the caller.
403 *
404 * Returns a positive value for the number of clocks obtained while the
405 * clock references are stored in the clk_bulk_data table in @clks field.
406 * Returns 0 if there're none and a negative value if something failed.
407 *
408 * Drivers must assume that the clock source is not enabled.
409 *
410 * clk_bulk_get should not be called from within interrupt context.
411 */
412int __must_check clk_bulk_get_all(struct device *dev,
413 struct clk_bulk_data **clks);
414
415/**
416 * clk_bulk_get_optional - lookup and obtain a number of references to clock producer
417 * @dev: device for clock "consumer"
418 * @num_clks: the number of clk_bulk_data
419 * @clks: the clk_bulk_data table of consumer
420 *
421 * Behaves the same as clk_bulk_get() except where there is no clock producer.
422 * In this case, instead of returning -ENOENT, the function returns 0 and
423 * NULL for a clk for which a clock producer could not be determined.
424 */
425int __must_check clk_bulk_get_optional(struct device *dev, int num_clks,
426 struct clk_bulk_data *clks);
427/**
428 * devm_clk_bulk_get - managed get multiple clk consumers
429 * @dev: device for clock "consumer"
430 * @num_clks: the number of clk_bulk_data
431 * @clks: the clk_bulk_data table of consumer
432 *
433 * Return 0 on success, an errno on failure.
434 *
435 * This helper function allows drivers to get several clk
436 * consumers in one operation with management, the clks will
437 * automatically be freed when the device is unbound.
438 */
439int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
440 struct clk_bulk_data *clks);
441/**
442 * devm_clk_bulk_get_optional - managed get multiple optional consumer clocks
443 * @dev: device for clock "consumer"
444 * @num_clks: the number of clk_bulk_data
445 * @clks: pointer to the clk_bulk_data table of consumer
446 *
447 * Behaves the same as devm_clk_bulk_get() except where there is no clock
448 * producer. In this case, instead of returning -ENOENT, the function returns
449 * NULL for given clk. It is assumed all clocks in clk_bulk_data are optional.
450 *
451 * Returns 0 if all clocks specified in clk_bulk_data table are obtained
452 * successfully or for any clk there was no clk provider available, otherwise
453 * returns valid IS_ERR() condition containing errno.
454 * The implementation uses @dev and @clk_bulk_data.id to determine the
455 * clock consumer, and thereby the clock producer.
456 * The clock returned is stored in each @clk_bulk_data.clk field.
457 *
458 * Drivers must assume that the clock source is not enabled.
459 *
460 * clk_bulk_get should not be called from within interrupt context.
461 */
462int __must_check devm_clk_bulk_get_optional(struct device *dev, int num_clks,
463 struct clk_bulk_data *clks);
464/**
465 * devm_clk_bulk_get_all - managed get multiple clk consumers
466 * @dev: device for clock "consumer"
467 * @clks: pointer to the clk_bulk_data table of consumer
468 *
469 * Returns a positive value for the number of clocks obtained while the
470 * clock references are stored in the clk_bulk_data table in @clks field.
471 * Returns 0 if there're none and a negative value if something failed.
472 *
473 * This helper function allows drivers to get several clk
474 * consumers in one operation with management, the clks will
475 * automatically be freed when the device is unbound.
476 */
477
478int __must_check devm_clk_bulk_get_all(struct device *dev,
479 struct clk_bulk_data **clks);
480
481/**
482 * devm_clk_get - lookup and obtain a managed reference to a clock producer.
483 * @dev: device for clock "consumer"
484 * @id: clock consumer ID
485 *
486 * Context: May sleep.
487 *
488 * Return: a struct clk corresponding to the clock producer, or
489 * valid IS_ERR() condition containing errno. The implementation
490 * uses @dev and @id to determine the clock consumer, and thereby
491 * the clock producer. (IOW, @id may be identical strings, but
492 * clk_get may return different clock producers depending on @dev.)
493 *
494 * Drivers must assume that the clock source is neither prepared nor
495 * enabled.
496 *
497 * The clock will automatically be freed when the device is unbound
498 * from the bus.
499 */
500struct clk *devm_clk_get(struct device *dev, const char *id);
501
502/**
503 * devm_clk_get_prepared - devm_clk_get() + clk_prepare()
504 * @dev: device for clock "consumer"
505 * @id: clock consumer ID
506 *
507 * Context: May sleep.
508 *
509 * Return: a struct clk corresponding to the clock producer, or
510 * valid IS_ERR() condition containing errno. The implementation
511 * uses @dev and @id to determine the clock consumer, and thereby
512 * the clock producer. (IOW, @id may be identical strings, but
513 * clk_get may return different clock producers depending on @dev.)
514 *
515 * The returned clk (if valid) is prepared. Drivers must however assume
516 * that the clock is not enabled.
517 *
518 * The clock will automatically be unprepared and freed when the device
519 * is unbound from the bus.
520 */
521struct clk *devm_clk_get_prepared(struct device *dev, const char *id);
522
523/**
524 * devm_clk_get_enabled - devm_clk_get() + clk_prepare_enable()
525 * @dev: device for clock "consumer"
526 * @id: clock consumer ID
527 *
528 * Context: May sleep.
529 *
530 * Return: a struct clk corresponding to the clock producer, or
531 * valid IS_ERR() condition containing errno. The implementation
532 * uses @dev and @id to determine the clock consumer, and thereby
533 * the clock producer. (IOW, @id may be identical strings, but
534 * clk_get may return different clock producers depending on @dev.)
535 *
536 * The returned clk (if valid) is prepared and enabled.
537 *
538 * The clock will automatically be disabled, unprepared and freed
539 * when the device is unbound from the bus.
540 */
541struct clk *devm_clk_get_enabled(struct device *dev, const char *id);
542
543/**
544 * devm_clk_get_optional - lookup and obtain a managed reference to an optional
545 * clock producer.
546 * @dev: device for clock "consumer"
547 * @id: clock consumer ID
548 *
549 * Context: May sleep.
550 *
551 * Return: a struct clk corresponding to the clock producer, or
552 * valid IS_ERR() condition containing errno. The implementation
553 * uses @dev and @id to determine the clock consumer, and thereby
554 * the clock producer. If no such clk is found, it returns NULL
555 * which serves as a dummy clk. That's the only difference compared
556 * to devm_clk_get().
557 *
558 * Drivers must assume that the clock source is neither prepared nor
559 * enabled.
560 *
561 * The clock will automatically be freed when the device is unbound
562 * from the bus.
563 */
564struct clk *devm_clk_get_optional(struct device *dev, const char *id);
565
566/**
567 * devm_clk_get_optional_prepared - devm_clk_get_optional() + clk_prepare()
568 * @dev: device for clock "consumer"
569 * @id: clock consumer ID
570 *
571 * Context: May sleep.
572 *
573 * Return: a struct clk corresponding to the clock producer, or
574 * valid IS_ERR() condition containing errno. The implementation
575 * uses @dev and @id to determine the clock consumer, and thereby
576 * the clock producer. If no such clk is found, it returns NULL
577 * which serves as a dummy clk. That's the only difference compared
578 * to devm_clk_get_prepared().
579 *
580 * The returned clk (if valid) is prepared. Drivers must however
581 * assume that the clock is not enabled.
582 *
583 * The clock will automatically be unprepared and freed when the
584 * device is unbound from the bus.
585 */
586struct clk *devm_clk_get_optional_prepared(struct device *dev, const char *id);
587
588/**
589 * devm_clk_get_optional_enabled - devm_clk_get_optional() +
590 * clk_prepare_enable()
591 * @dev: device for clock "consumer"
592 * @id: clock consumer ID
593 *
594 * Context: May sleep.
595 *
596 * Return: a struct clk corresponding to the clock producer, or
597 * valid IS_ERR() condition containing errno. The implementation
598 * uses @dev and @id to determine the clock consumer, and thereby
599 * the clock producer. If no such clk is found, it returns NULL
600 * which serves as a dummy clk. That's the only difference compared
601 * to devm_clk_get_enabled().
602 *
603 * The returned clk (if valid) is prepared and enabled.
604 *
605 * The clock will automatically be disabled, unprepared and freed
606 * when the device is unbound from the bus.
607 */
608struct clk *devm_clk_get_optional_enabled(struct device *dev, const char *id);
609
610/**
611 * devm_get_clk_from_child - lookup and obtain a managed reference to a
612 * clock producer from child node.
613 * @dev: device for clock "consumer"
614 * @np: pointer to clock consumer node
615 * @con_id: clock consumer ID
616 *
617 * This function parses the clocks, and uses them to look up the
618 * struct clk from the registered list of clock providers by using
619 * @np and @con_id
620 *
621 * The clock will automatically be freed when the device is unbound
622 * from the bus.
623 */
624struct clk *devm_get_clk_from_child(struct device *dev,
625 struct device_node *np, const char *con_id);
626
627/**
628 * clk_enable - inform the system when the clock source should be running.
629 * @clk: clock source
630 *
631 * If the clock can not be enabled/disabled, this should return success.
632 *
633 * May be called from atomic contexts.
634 *
635 * Returns success (0) or negative errno.
636 */
637int clk_enable(struct clk *clk);
638
639/**
640 * clk_bulk_enable - inform the system when the set of clks should be running.
641 * @num_clks: the number of clk_bulk_data
642 * @clks: the clk_bulk_data table of consumer
643 *
644 * May be called from atomic contexts.
645 *
646 * Returns success (0) or negative errno.
647 */
648int __must_check clk_bulk_enable(int num_clks,
649 const struct clk_bulk_data *clks);
650
651/**
652 * clk_disable - inform the system when the clock source is no longer required.
653 * @clk: clock source
654 *
655 * Inform the system that a clock source is no longer required by
656 * a driver and may be shut down.
657 *
658 * May be called from atomic contexts.
659 *
660 * Implementation detail: if the clock source is shared between
661 * multiple drivers, clk_enable() calls must be balanced by the
662 * same number of clk_disable() calls for the clock source to be
663 * disabled.
664 */
665void clk_disable(struct clk *clk);
666
667/**
668 * clk_bulk_disable - inform the system when the set of clks is no
669 * longer required.
670 * @num_clks: the number of clk_bulk_data
671 * @clks: the clk_bulk_data table of consumer
672 *
673 * Inform the system that a set of clks is no longer required by
674 * a driver and may be shut down.
675 *
676 * May be called from atomic contexts.
677 *
678 * Implementation detail: if the set of clks is shared between
679 * multiple drivers, clk_bulk_enable() calls must be balanced by the
680 * same number of clk_bulk_disable() calls for the clock source to be
681 * disabled.
682 */
683void clk_bulk_disable(int num_clks, const struct clk_bulk_data *clks);
684
685/**
686 * clk_get_rate - obtain the current clock rate (in Hz) for a clock source.
687 * This is only valid once the clock source has been enabled.
688 * @clk: clock source
689 */
690unsigned long clk_get_rate(struct clk *clk);
691
692/**
693 * clk_put - "free" the clock source
694 * @clk: clock source
695 *
696 * Note: drivers must ensure that all clk_enable calls made on this
697 * clock source are balanced by clk_disable calls prior to calling
698 * this function.
699 *
700 * clk_put should not be called from within interrupt context.
701 */
702void clk_put(struct clk *clk);
703
704/**
705 * clk_bulk_put - "free" the clock source
706 * @num_clks: the number of clk_bulk_data
707 * @clks: the clk_bulk_data table of consumer
708 *
709 * Note: drivers must ensure that all clk_bulk_enable calls made on this
710 * clock source are balanced by clk_bulk_disable calls prior to calling
711 * this function.
712 *
713 * clk_bulk_put should not be called from within interrupt context.
714 */
715void clk_bulk_put(int num_clks, struct clk_bulk_data *clks);
716
717/**
718 * clk_bulk_put_all - "free" all the clock source
719 * @num_clks: the number of clk_bulk_data
720 * @clks: the clk_bulk_data table of consumer
721 *
722 * Note: drivers must ensure that all clk_bulk_enable calls made on this
723 * clock source are balanced by clk_bulk_disable calls prior to calling
724 * this function.
725 *
726 * clk_bulk_put_all should not be called from within interrupt context.
727 */
728void clk_bulk_put_all(int num_clks, struct clk_bulk_data *clks);
729
730/**
731 * devm_clk_put - "free" a managed clock source
732 * @dev: device used to acquire the clock
733 * @clk: clock source acquired with devm_clk_get()
734 *
735 * Note: drivers must ensure that all clk_enable calls made on this
736 * clock source are balanced by clk_disable calls prior to calling
737 * this function.
738 *
739 * clk_put should not be called from within interrupt context.
740 */
741void devm_clk_put(struct device *dev, struct clk *clk);
742
743/*
744 * The remaining APIs are optional for machine class support.
745 */
746
747
748/**
749 * clk_round_rate - adjust a rate to the exact rate a clock can provide
750 * @clk: clock source
751 * @rate: desired clock rate in Hz
752 *
753 * This answers the question "if I were to pass @rate to clk_set_rate(),
754 * what clock rate would I end up with?" without changing the hardware
755 * in any way. In other words:
756 *
757 * rate = clk_round_rate(clk, r);
758 *
759 * and:
760 *
761 * clk_set_rate(clk, r);
762 * rate = clk_get_rate(clk);
763 *
764 * are equivalent except the former does not modify the clock hardware
765 * in any way.
766 *
767 * Returns rounded clock rate in Hz, or negative errno.
768 */
769long clk_round_rate(struct clk *clk, unsigned long rate);
770
771/**
772 * clk_set_rate - set the clock rate for a clock source
773 * @clk: clock source
774 * @rate: desired clock rate in Hz
775 *
776 * Updating the rate starts at the top-most affected clock and then
777 * walks the tree down to the bottom-most clock that needs updating.
778 *
779 * Returns success (0) or negative errno.
780 */
781int clk_set_rate(struct clk *clk, unsigned long rate);
782
783/**
784 * clk_set_rate_exclusive- set the clock rate and claim exclusivity over
785 * clock source
786 * @clk: clock source
787 * @rate: desired clock rate in Hz
788 *
789 * This helper function allows drivers to atomically set the rate of a producer
790 * and claim exclusivity over the rate control of the producer.
791 *
792 * It is essentially a combination of clk_set_rate() and
793 * clk_rate_exclusite_get(). Caller must balance this call with a call to
794 * clk_rate_exclusive_put()
795 *
796 * Returns success (0) or negative errno.
797 */
798int clk_set_rate_exclusive(struct clk *clk, unsigned long rate);
799
800/**
801 * clk_has_parent - check if a clock is a possible parent for another
802 * @clk: clock source
803 * @parent: parent clock source
804 *
805 * This function can be used in drivers that need to check that a clock can be
806 * the parent of another without actually changing the parent.
807 *
808 * Returns true if @parent is a possible parent for @clk, false otherwise.
809 */
810bool clk_has_parent(const struct clk *clk, const struct clk *parent);
811
812/**
813 * clk_set_rate_range - set a rate range for a clock source
814 * @clk: clock source
815 * @min: desired minimum clock rate in Hz, inclusive
816 * @max: desired maximum clock rate in Hz, inclusive
817 *
818 * Returns success (0) or negative errno.
819 */
820int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max);
821
822/**
823 * clk_set_min_rate - set a minimum clock rate for a clock source
824 * @clk: clock source
825 * @rate: desired minimum clock rate in Hz, inclusive
826 *
827 * Returns success (0) or negative errno.
828 */
829int clk_set_min_rate(struct clk *clk, unsigned long rate);
830
831/**
832 * clk_set_max_rate - set a maximum clock rate for a clock source
833 * @clk: clock source
834 * @rate: desired maximum clock rate in Hz, inclusive
835 *
836 * Returns success (0) or negative errno.
837 */
838int clk_set_max_rate(struct clk *clk, unsigned long rate);
839
840/**
841 * clk_set_parent - set the parent clock source for this clock
842 * @clk: clock source
843 * @parent: parent clock source
844 *
845 * Returns success (0) or negative errno.
846 */
847int clk_set_parent(struct clk *clk, struct clk *parent);
848
849/**
850 * clk_get_parent - get the parent clock source for this clock
851 * @clk: clock source
852 *
853 * Returns struct clk corresponding to parent clock source, or
854 * valid IS_ERR() condition containing errno.
855 */
856struct clk *clk_get_parent(struct clk *clk);
857
858/**
859 * clk_get_sys - get a clock based upon the device name
860 * @dev_id: device name
861 * @con_id: connection ID
862 *
863 * Returns a struct clk corresponding to the clock producer, or
864 * valid IS_ERR() condition containing errno. The implementation
865 * uses @dev_id and @con_id to determine the clock consumer, and
866 * thereby the clock producer. In contrast to clk_get() this function
867 * takes the device name instead of the device itself for identification.
868 *
869 * Drivers must assume that the clock source is not enabled.
870 *
871 * clk_get_sys should not be called from within interrupt context.
872 */
873struct clk *clk_get_sys(const char *dev_id, const char *con_id);
874
875/**
876 * clk_save_context - save clock context for poweroff
877 *
878 * Saves the context of the clock register for powerstates in which the
879 * contents of the registers will be lost. Occurs deep within the suspend
880 * code so locking is not necessary.
881 */
882int clk_save_context(void);
883
884/**
885 * clk_restore_context - restore clock context after poweroff
886 *
887 * This occurs with all clocks enabled. Occurs deep within the resume code
888 * so locking is not necessary.
889 */
890void clk_restore_context(void);
891
892#else /* !CONFIG_HAVE_CLK */
893
894static inline struct clk *clk_get(struct device *dev, const char *id)
895{
896 return NULL;
897}
898
899static inline int __must_check clk_bulk_get(struct device *dev, int num_clks,
900 struct clk_bulk_data *clks)
901{
902 return 0;
903}
904
905static inline int __must_check clk_bulk_get_optional(struct device *dev,
906 int num_clks, struct clk_bulk_data *clks)
907{
908 return 0;
909}
910
911static inline int __must_check clk_bulk_get_all(struct device *dev,
912 struct clk_bulk_data **clks)
913{
914 return 0;
915}
916
917static inline struct clk *devm_clk_get(struct device *dev, const char *id)
918{
919 return NULL;
920}
921
922static inline struct clk *devm_clk_get_prepared(struct device *dev,
923 const char *id)
924{
925 return NULL;
926}
927
928static inline struct clk *devm_clk_get_enabled(struct device *dev,
929 const char *id)
930{
931 return NULL;
932}
933
934static inline struct clk *devm_clk_get_optional(struct device *dev,
935 const char *id)
936{
937 return NULL;
938}
939
940static inline struct clk *devm_clk_get_optional_prepared(struct device *dev,
941 const char *id)
942{
943 return NULL;
944}
945
946static inline struct clk *devm_clk_get_optional_enabled(struct device *dev,
947 const char *id)
948{
949 return NULL;
950}
951
952static inline int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
953 struct clk_bulk_data *clks)
954{
955 return 0;
956}
957
958static inline int __must_check devm_clk_bulk_get_optional(struct device *dev,
959 int num_clks, struct clk_bulk_data *clks)
960{
961 return 0;
962}
963
964static inline int __must_check devm_clk_bulk_get_all(struct device *dev,
965 struct clk_bulk_data **clks)
966{
967
968 return 0;
969}
970
971static inline struct clk *devm_get_clk_from_child(struct device *dev,
972 struct device_node *np, const char *con_id)
973{
974 return NULL;
975}
976
977static inline void clk_put(struct clk *clk) {}
978
979static inline void clk_bulk_put(int num_clks, struct clk_bulk_data *clks) {}
980
981static inline void clk_bulk_put_all(int num_clks, struct clk_bulk_data *clks) {}
982
983static inline void devm_clk_put(struct device *dev, struct clk *clk) {}
984
985static inline int clk_enable(struct clk *clk)
986{
987 return 0;
988}
989
990static inline int __must_check clk_bulk_enable(int num_clks,
991 const struct clk_bulk_data *clks)
992{
993 return 0;
994}
995
996static inline void clk_disable(struct clk *clk) {}
997
998
999static inline void clk_bulk_disable(int num_clks,
1000 const struct clk_bulk_data *clks) {}
1001
1002static inline unsigned long clk_get_rate(struct clk *clk)
1003{
1004 return 0;
1005}
1006
1007static inline int clk_set_rate(struct clk *clk, unsigned long rate)
1008{
1009 return 0;
1010}
1011
1012static inline int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
1013{
1014 return 0;
1015}
1016
1017static inline long clk_round_rate(struct clk *clk, unsigned long rate)
1018{
1019 return 0;
1020}
1021
1022static inline bool clk_has_parent(struct clk *clk, struct clk *parent)
1023{
1024 return true;
1025}
1026
1027static inline int clk_set_rate_range(struct clk *clk, unsigned long min,
1028 unsigned long max)
1029{
1030 return 0;
1031}
1032
1033static inline int clk_set_min_rate(struct clk *clk, unsigned long rate)
1034{
1035 return 0;
1036}
1037
1038static inline int clk_set_max_rate(struct clk *clk, unsigned long rate)
1039{
1040 return 0;
1041}
1042
1043static inline int clk_set_parent(struct clk *clk, struct clk *parent)
1044{
1045 return 0;
1046}
1047
1048static inline struct clk *clk_get_parent(struct clk *clk)
1049{
1050 return NULL;
1051}
1052
1053static inline struct clk *clk_get_sys(const char *dev_id, const char *con_id)
1054{
1055 return NULL;
1056}
1057
1058static inline int clk_save_context(void)
1059{
1060 return 0;
1061}
1062
1063static inline void clk_restore_context(void) {}
1064
1065#endif
1066
1067/* clk_prepare_enable helps cases using clk_enable in non-atomic context. */
1068static inline int clk_prepare_enable(struct clk *clk)
1069{
1070 int ret;
1071
1072 ret = clk_prepare(clk);
1073 if (ret)
1074 return ret;
1075 ret = clk_enable(clk);
1076 if (ret)
1077 clk_unprepare(clk);
1078
1079 return ret;
1080}
1081
1082/* clk_disable_unprepare helps cases using clk_disable in non-atomic context. */
1083static inline void clk_disable_unprepare(struct clk *clk)
1084{
1085 clk_disable(clk);
1086 clk_unprepare(clk);
1087}
1088
1089static inline int __must_check
1090clk_bulk_prepare_enable(int num_clks, const struct clk_bulk_data *clks)
1091{
1092 int ret;
1093
1094 ret = clk_bulk_prepare(num_clks, clks);
1095 if (ret)
1096 return ret;
1097 ret = clk_bulk_enable(num_clks, clks);
1098 if (ret)
1099 clk_bulk_unprepare(num_clks, clks);
1100
1101 return ret;
1102}
1103
1104static inline void clk_bulk_disable_unprepare(int num_clks,
1105 const struct clk_bulk_data *clks)
1106{
1107 clk_bulk_disable(num_clks, clks);
1108 clk_bulk_unprepare(num_clks, clks);
1109}
1110
1111/**
1112 * clk_drop_range - Reset any range set on that clock
1113 * @clk: clock source
1114 *
1115 * Returns success (0) or negative errno.
1116 */
1117static inline int clk_drop_range(struct clk *clk)
1118{
1119 return clk_set_rate_range(clk, min: 0, ULONG_MAX);
1120}
1121
1122/**
1123 * clk_get_optional - lookup and obtain a reference to an optional clock
1124 * producer.
1125 * @dev: device for clock "consumer"
1126 * @id: clock consumer ID
1127 *
1128 * Behaves the same as clk_get() except where there is no clock producer. In
1129 * this case, instead of returning -ENOENT, the function returns NULL.
1130 */
1131static inline struct clk *clk_get_optional(struct device *dev, const char *id)
1132{
1133 struct clk *clk = clk_get(dev, id);
1134
1135 if (clk == ERR_PTR(error: -ENOENT))
1136 return NULL;
1137
1138 return clk;
1139}
1140
1141#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
1142struct clk *of_clk_get(struct device_node *np, int index);
1143struct clk *of_clk_get_by_name(struct device_node *np, const char *name);
1144struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec);
1145#else
1146static inline struct clk *of_clk_get(struct device_node *np, int index)
1147{
1148 return ERR_PTR(-ENOENT);
1149}
1150static inline struct clk *of_clk_get_by_name(struct device_node *np,
1151 const char *name)
1152{
1153 return ERR_PTR(-ENOENT);
1154}
1155static inline struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
1156{
1157 return ERR_PTR(-ENOENT);
1158}
1159#endif
1160
1161#endif
1162

source code of linux/include/linux/clk.h