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 * devm_clk_rate_exclusive_get - devm variant of clk_rate_exclusive_get
206 * @dev: device the exclusivity is bound to
207 * @clk: clock source
208 *
209 * Calls clk_rate_exclusive_get() on @clk and registers a devm cleanup handler
210 * on @dev to call clk_rate_exclusive_put().
211 *
212 * Must not be called from within atomic context.
213 */
214int devm_clk_rate_exclusive_get(struct device *dev, struct clk *clk);
215
216/**
217 * clk_rate_exclusive_put - release exclusivity over the rate control of a
218 * producer
219 * @clk: clock source
220 *
221 * This function allows drivers to release the exclusivity it previously got
222 * from clk_rate_exclusive_get()
223 *
224 * The caller must balance the number of clk_rate_exclusive_get() and
225 * clk_rate_exclusive_put() calls.
226 *
227 * Must not be called from within atomic context.
228 */
229void clk_rate_exclusive_put(struct clk *clk);
230
231#else
232
233static inline int clk_notifier_register(struct clk *clk,
234 struct notifier_block *nb)
235{
236 return -ENOTSUPP;
237}
238
239static inline int clk_notifier_unregister(struct clk *clk,
240 struct notifier_block *nb)
241{
242 return -ENOTSUPP;
243}
244
245static inline int devm_clk_notifier_register(struct device *dev,
246 struct clk *clk,
247 struct notifier_block *nb)
248{
249 return -ENOTSUPP;
250}
251
252static inline long clk_get_accuracy(struct clk *clk)
253{
254 return -ENOTSUPP;
255}
256
257static inline long clk_set_phase(struct clk *clk, int phase)
258{
259 return -ENOTSUPP;
260}
261
262static inline long clk_get_phase(struct clk *clk)
263{
264 return -ENOTSUPP;
265}
266
267static inline int clk_set_duty_cycle(struct clk *clk, unsigned int num,
268 unsigned int den)
269{
270 return -ENOTSUPP;
271}
272
273static inline unsigned int clk_get_scaled_duty_cycle(struct clk *clk,
274 unsigned int scale)
275{
276 return 0;
277}
278
279static inline bool clk_is_match(const struct clk *p, const struct clk *q)
280{
281 return p == q;
282}
283
284static inline int clk_rate_exclusive_get(struct clk *clk)
285{
286 return 0;
287}
288
289static inline int devm_clk_rate_exclusive_get(struct device *dev, struct clk *clk)
290{
291 return 0;
292}
293
294static inline void clk_rate_exclusive_put(struct clk *clk) {}
295
296#endif
297
298#ifdef CONFIG_HAVE_CLK_PREPARE
299/**
300 * clk_prepare - prepare a clock source
301 * @clk: clock source
302 *
303 * This prepares the clock source for use.
304 *
305 * Must not be called from within atomic context.
306 */
307int clk_prepare(struct clk *clk);
308int __must_check clk_bulk_prepare(int num_clks,
309 const struct clk_bulk_data *clks);
310
311/**
312 * clk_is_enabled_when_prepared - indicate if preparing a clock also enables it.
313 * @clk: clock source
314 *
315 * Returns true if clk_prepare() implicitly enables the clock, effectively
316 * making clk_enable()/clk_disable() no-ops, false otherwise.
317 *
318 * This is of interest mainly to the power management code where actually
319 * disabling the clock also requires unpreparing it to have any material
320 * effect.
321 *
322 * Regardless of the value returned here, the caller must always invoke
323 * clk_enable() or clk_prepare_enable() and counterparts for usage counts
324 * to be right.
325 */
326bool clk_is_enabled_when_prepared(struct clk *clk);
327#else
328static inline int clk_prepare(struct clk *clk)
329{
330 might_sleep();
331 return 0;
332}
333
334static inline int __must_check
335clk_bulk_prepare(int num_clks, const struct clk_bulk_data *clks)
336{
337 might_sleep();
338 return 0;
339}
340
341static inline bool clk_is_enabled_when_prepared(struct clk *clk)
342{
343 return false;
344}
345#endif
346
347/**
348 * clk_unprepare - undo preparation of a clock source
349 * @clk: clock source
350 *
351 * This undoes a previously prepared clock. The caller must balance
352 * the number of prepare and unprepare calls.
353 *
354 * Must not be called from within atomic context.
355 */
356#ifdef CONFIG_HAVE_CLK_PREPARE
357void clk_unprepare(struct clk *clk);
358void clk_bulk_unprepare(int num_clks, const struct clk_bulk_data *clks);
359#else
360static inline void clk_unprepare(struct clk *clk)
361{
362 might_sleep();
363}
364static inline void clk_bulk_unprepare(int num_clks,
365 const struct clk_bulk_data *clks)
366{
367 might_sleep();
368}
369#endif
370
371#ifdef CONFIG_HAVE_CLK
372/**
373 * clk_get - lookup and obtain a reference to a clock producer.
374 * @dev: device for clock "consumer"
375 * @id: clock consumer ID
376 *
377 * Returns a struct clk corresponding to the clock producer, or
378 * valid IS_ERR() condition containing errno. The implementation
379 * uses @dev and @id to determine the clock consumer, and thereby
380 * the clock producer. (IOW, @id may be identical strings, but
381 * clk_get may return different clock producers depending on @dev.)
382 *
383 * Drivers must assume that the clock source is not enabled.
384 *
385 * clk_get should not be called from within interrupt context.
386 */
387struct clk *clk_get(struct device *dev, const char *id);
388
389/**
390 * clk_bulk_get - lookup and obtain a number of references to clock producer.
391 * @dev: device for clock "consumer"
392 * @num_clks: the number of clk_bulk_data
393 * @clks: the clk_bulk_data table of consumer
394 *
395 * This helper function allows drivers to get several clk consumers in one
396 * operation. If any of the clk cannot be acquired then any clks
397 * that were obtained will be freed before returning to the caller.
398 *
399 * Returns 0 if all clocks specified in clk_bulk_data table are obtained
400 * successfully, or valid IS_ERR() condition containing errno.
401 * The implementation uses @dev and @clk_bulk_data.id to determine the
402 * clock consumer, and thereby the clock producer.
403 * The clock returned is stored in each @clk_bulk_data.clk field.
404 *
405 * Drivers must assume that the clock source is not enabled.
406 *
407 * clk_bulk_get should not be called from within interrupt context.
408 */
409int __must_check clk_bulk_get(struct device *dev, int num_clks,
410 struct clk_bulk_data *clks);
411/**
412 * clk_bulk_get_all - lookup and obtain all available references to clock
413 * producer.
414 * @dev: device for clock "consumer"
415 * @clks: pointer to the clk_bulk_data table of consumer
416 *
417 * This helper function allows drivers to get all clk consumers in one
418 * operation. If any of the clk cannot be acquired then any clks
419 * that were obtained will be freed before returning to the caller.
420 *
421 * Returns a positive value for the number of clocks obtained while the
422 * clock references are stored in the clk_bulk_data table in @clks field.
423 * Returns 0 if there're none and a negative value if something failed.
424 *
425 * Drivers must assume that the clock source is not enabled.
426 *
427 * clk_bulk_get should not be called from within interrupt context.
428 */
429int __must_check clk_bulk_get_all(struct device *dev,
430 struct clk_bulk_data **clks);
431
432/**
433 * clk_bulk_get_optional - lookup and obtain a number of references to clock producer
434 * @dev: device for clock "consumer"
435 * @num_clks: the number of clk_bulk_data
436 * @clks: the clk_bulk_data table of consumer
437 *
438 * Behaves the same as clk_bulk_get() except where there is no clock producer.
439 * In this case, instead of returning -ENOENT, the function returns 0 and
440 * NULL for a clk for which a clock producer could not be determined.
441 */
442int __must_check clk_bulk_get_optional(struct device *dev, int num_clks,
443 struct clk_bulk_data *clks);
444/**
445 * devm_clk_bulk_get - managed get multiple clk consumers
446 * @dev: device for clock "consumer"
447 * @num_clks: the number of clk_bulk_data
448 * @clks: the clk_bulk_data table of consumer
449 *
450 * Return 0 on success, an errno on failure.
451 *
452 * This helper function allows drivers to get several clk
453 * consumers in one operation with management, the clks will
454 * automatically be freed when the device is unbound.
455 */
456int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
457 struct clk_bulk_data *clks);
458/**
459 * devm_clk_bulk_get_optional - managed get multiple optional consumer clocks
460 * @dev: device for clock "consumer"
461 * @num_clks: the number of clk_bulk_data
462 * @clks: pointer to the clk_bulk_data table of consumer
463 *
464 * Behaves the same as devm_clk_bulk_get() except where there is no clock
465 * producer. In this case, instead of returning -ENOENT, the function returns
466 * NULL for given clk. It is assumed all clocks in clk_bulk_data are optional.
467 *
468 * Returns 0 if all clocks specified in clk_bulk_data table are obtained
469 * successfully or for any clk there was no clk provider available, otherwise
470 * returns valid IS_ERR() condition containing errno.
471 * The implementation uses @dev and @clk_bulk_data.id to determine the
472 * clock consumer, and thereby the clock producer.
473 * The clock returned is stored in each @clk_bulk_data.clk field.
474 *
475 * Drivers must assume that the clock source is not enabled.
476 *
477 * clk_bulk_get should not be called from within interrupt context.
478 */
479int __must_check devm_clk_bulk_get_optional(struct device *dev, int num_clks,
480 struct clk_bulk_data *clks);
481/**
482 * devm_clk_bulk_get_all - managed get multiple clk consumers
483 * @dev: device for clock "consumer"
484 * @clks: pointer to the clk_bulk_data table of consumer
485 *
486 * Returns a positive value for the number of clocks obtained while the
487 * clock references are stored in the clk_bulk_data table in @clks field.
488 * Returns 0 if there're none and a negative value if something failed.
489 *
490 * This helper function allows drivers to get several clk
491 * consumers in one operation with management, the clks will
492 * automatically be freed when the device is unbound.
493 */
494
495int __must_check devm_clk_bulk_get_all(struct device *dev,
496 struct clk_bulk_data **clks);
497
498/**
499 * devm_clk_bulk_get_all_enabled - Get and enable all clocks of the consumer (managed)
500 * @dev: device for clock "consumer"
501 * @clks: pointer to the clk_bulk_data table of consumer
502 *
503 * Returns a positive value for the number of clocks obtained while the
504 * clock references are stored in the clk_bulk_data table in @clks field.
505 * Returns 0 if there're none and a negative value if something failed.
506 *
507 * This helper function allows drivers to get all clocks of the
508 * consumer and enables them in one operation with management.
509 * The clks will automatically be disabled and freed when the device
510 * is unbound.
511 */
512
513int __must_check devm_clk_bulk_get_all_enabled(struct device *dev,
514 struct clk_bulk_data **clks);
515
516/**
517 * devm_clk_get - lookup and obtain a managed reference to a clock producer.
518 * @dev: device for clock "consumer"
519 * @id: clock consumer ID
520 *
521 * Context: May sleep.
522 *
523 * Return: a struct clk corresponding to the clock producer, or
524 * valid IS_ERR() condition containing errno. The implementation
525 * uses @dev and @id to determine the clock consumer, and thereby
526 * the clock producer. (IOW, @id may be identical strings, but
527 * clk_get may return different clock producers depending on @dev.)
528 *
529 * Drivers must assume that the clock source is neither prepared nor
530 * enabled.
531 *
532 * The clock will automatically be freed when the device is unbound
533 * from the bus.
534 */
535struct clk *devm_clk_get(struct device *dev, const char *id);
536
537/**
538 * devm_clk_get_prepared - devm_clk_get() + clk_prepare()
539 * @dev: device for clock "consumer"
540 * @id: clock consumer ID
541 *
542 * Context: May sleep.
543 *
544 * Return: a struct clk corresponding to the clock producer, or
545 * valid IS_ERR() condition containing errno. The implementation
546 * uses @dev and @id to determine the clock consumer, and thereby
547 * the clock producer. (IOW, @id may be identical strings, but
548 * clk_get may return different clock producers depending on @dev.)
549 *
550 * The returned clk (if valid) is prepared. Drivers must however assume
551 * that the clock is not enabled.
552 *
553 * The clock will automatically be unprepared and freed when the device
554 * is unbound from the bus.
555 */
556struct clk *devm_clk_get_prepared(struct device *dev, const char *id);
557
558/**
559 * devm_clk_get_enabled - devm_clk_get() + clk_prepare_enable()
560 * @dev: device for clock "consumer"
561 * @id: clock consumer ID
562 *
563 * Context: May sleep.
564 *
565 * Return: a struct clk corresponding to the clock producer, or
566 * valid IS_ERR() condition containing errno. The implementation
567 * uses @dev and @id to determine the clock consumer, and thereby
568 * the clock producer. (IOW, @id may be identical strings, but
569 * clk_get may return different clock producers depending on @dev.)
570 *
571 * The returned clk (if valid) is prepared and enabled.
572 *
573 * The clock will automatically be disabled, unprepared and freed
574 * when the device is unbound from the bus.
575 */
576struct clk *devm_clk_get_enabled(struct device *dev, const char *id);
577
578/**
579 * devm_clk_get_optional - lookup and obtain a managed reference to an optional
580 * clock producer.
581 * @dev: device for clock "consumer"
582 * @id: clock consumer ID
583 *
584 * Context: May sleep.
585 *
586 * Return: a struct clk corresponding to the clock producer, or
587 * valid IS_ERR() condition containing errno. The implementation
588 * uses @dev and @id to determine the clock consumer, and thereby
589 * the clock producer. If no such clk is found, it returns NULL
590 * which serves as a dummy clk. That's the only difference compared
591 * to devm_clk_get().
592 *
593 * Drivers must assume that the clock source is neither prepared nor
594 * enabled.
595 *
596 * The clock will automatically be freed when the device is unbound
597 * from the bus.
598 */
599struct clk *devm_clk_get_optional(struct device *dev, const char *id);
600
601/**
602 * devm_clk_get_optional_prepared - devm_clk_get_optional() + clk_prepare()
603 * @dev: device for clock "consumer"
604 * @id: clock consumer ID
605 *
606 * Context: May sleep.
607 *
608 * Return: a struct clk corresponding to the clock producer, or
609 * valid IS_ERR() condition containing errno. The implementation
610 * uses @dev and @id to determine the clock consumer, and thereby
611 * the clock producer. If no such clk is found, it returns NULL
612 * which serves as a dummy clk. That's the only difference compared
613 * to devm_clk_get_prepared().
614 *
615 * The returned clk (if valid) is prepared. Drivers must however
616 * assume that the clock is not enabled.
617 *
618 * The clock will automatically be unprepared and freed when the
619 * device is unbound from the bus.
620 */
621struct clk *devm_clk_get_optional_prepared(struct device *dev, const char *id);
622
623/**
624 * devm_clk_get_optional_enabled - devm_clk_get_optional() +
625 * clk_prepare_enable()
626 * @dev: device for clock "consumer"
627 * @id: clock consumer ID
628 *
629 * Context: May sleep.
630 *
631 * Return: a struct clk corresponding to the clock producer, or
632 * valid IS_ERR() condition containing errno. The implementation
633 * uses @dev and @id to determine the clock consumer, and thereby
634 * the clock producer. If no such clk is found, it returns NULL
635 * which serves as a dummy clk. That's the only difference compared
636 * to devm_clk_get_enabled().
637 *
638 * The returned clk (if valid) is prepared and enabled.
639 *
640 * The clock will automatically be disabled, unprepared and freed
641 * when the device is unbound from the bus.
642 */
643struct clk *devm_clk_get_optional_enabled(struct device *dev, const char *id);
644
645/**
646 * devm_clk_get_optional_enabled_with_rate - devm_clk_get_optional() +
647 * clk_set_rate() +
648 * clk_prepare_enable()
649 * @dev: device for clock "consumer"
650 * @id: clock consumer ID
651 * @rate: new clock rate
652 *
653 * Context: May sleep.
654 *
655 * Return: a struct clk corresponding to the clock producer, or
656 * valid IS_ERR() condition containing errno. The implementation
657 * uses @dev and @id to determine the clock consumer, and thereby
658 * the clock producer. If no such clk is found, it returns NULL
659 * which serves as a dummy clk. That's the only difference compared
660 * to devm_clk_get_enabled().
661 *
662 * The returned clk (if valid) is prepared and enabled and rate was set.
663 *
664 * The clock will automatically be disabled, unprepared and freed
665 * when the device is unbound from the bus.
666 */
667struct clk *devm_clk_get_optional_enabled_with_rate(struct device *dev,
668 const char *id,
669 unsigned long rate);
670
671/**
672 * devm_get_clk_from_child - lookup and obtain a managed reference to a
673 * clock producer from child node.
674 * @dev: device for clock "consumer"
675 * @np: pointer to clock consumer node
676 * @con_id: clock consumer ID
677 *
678 * This function parses the clocks, and uses them to look up the
679 * struct clk from the registered list of clock providers by using
680 * @np and @con_id
681 *
682 * The clock will automatically be freed when the device is unbound
683 * from the bus.
684 */
685struct clk *devm_get_clk_from_child(struct device *dev,
686 struct device_node *np, const char *con_id);
687
688/**
689 * clk_enable - inform the system when the clock source should be running.
690 * @clk: clock source
691 *
692 * If the clock can not be enabled/disabled, this should return success.
693 *
694 * May be called from atomic contexts.
695 *
696 * Returns success (0) or negative errno.
697 */
698int clk_enable(struct clk *clk);
699
700/**
701 * clk_bulk_enable - inform the system when the set of clks should be running.
702 * @num_clks: the number of clk_bulk_data
703 * @clks: the clk_bulk_data table of consumer
704 *
705 * May be called from atomic contexts.
706 *
707 * Returns success (0) or negative errno.
708 */
709int __must_check clk_bulk_enable(int num_clks,
710 const struct clk_bulk_data *clks);
711
712/**
713 * clk_disable - inform the system when the clock source is no longer required.
714 * @clk: clock source
715 *
716 * Inform the system that a clock source is no longer required by
717 * a driver and may be shut down.
718 *
719 * May be called from atomic contexts.
720 *
721 * Implementation detail: if the clock source is shared between
722 * multiple drivers, clk_enable() calls must be balanced by the
723 * same number of clk_disable() calls for the clock source to be
724 * disabled.
725 */
726void clk_disable(struct clk *clk);
727
728/**
729 * clk_bulk_disable - inform the system when the set of clks is no
730 * longer required.
731 * @num_clks: the number of clk_bulk_data
732 * @clks: the clk_bulk_data table of consumer
733 *
734 * Inform the system that a set of clks is no longer required by
735 * a driver and may be shut down.
736 *
737 * May be called from atomic contexts.
738 *
739 * Implementation detail: if the set of clks is shared between
740 * multiple drivers, clk_bulk_enable() calls must be balanced by the
741 * same number of clk_bulk_disable() calls for the clock source to be
742 * disabled.
743 */
744void clk_bulk_disable(int num_clks, const struct clk_bulk_data *clks);
745
746/**
747 * clk_get_rate - obtain the current clock rate (in Hz) for a clock source.
748 * This is only valid once the clock source has been enabled.
749 * @clk: clock source
750 */
751unsigned long clk_get_rate(struct clk *clk);
752
753/**
754 * clk_put - "free" the clock source
755 * @clk: clock source
756 *
757 * Note: drivers must ensure that all clk_enable calls made on this
758 * clock source are balanced by clk_disable calls prior to calling
759 * this function.
760 *
761 * clk_put should not be called from within interrupt context.
762 */
763void clk_put(struct clk *clk);
764
765/**
766 * clk_bulk_put - "free" the clock source
767 * @num_clks: the number of clk_bulk_data
768 * @clks: the clk_bulk_data table of consumer
769 *
770 * Note: drivers must ensure that all clk_bulk_enable calls made on this
771 * clock source are balanced by clk_bulk_disable calls prior to calling
772 * this function.
773 *
774 * clk_bulk_put should not be called from within interrupt context.
775 */
776void clk_bulk_put(int num_clks, struct clk_bulk_data *clks);
777
778/**
779 * clk_bulk_put_all - "free" all the clock source
780 * @num_clks: the number of clk_bulk_data
781 * @clks: the clk_bulk_data table of consumer
782 *
783 * Note: drivers must ensure that all clk_bulk_enable calls made on this
784 * clock source are balanced by clk_bulk_disable calls prior to calling
785 * this function.
786 *
787 * clk_bulk_put_all should not be called from within interrupt context.
788 */
789void clk_bulk_put_all(int num_clks, struct clk_bulk_data *clks);
790
791/**
792 * devm_clk_put - "free" a managed clock source
793 * @dev: device used to acquire the clock
794 * @clk: clock source acquired with devm_clk_get()
795 *
796 * Note: drivers must ensure that all clk_enable calls made on this
797 * clock source are balanced by clk_disable calls prior to calling
798 * this function.
799 *
800 * clk_put should not be called from within interrupt context.
801 */
802void devm_clk_put(struct device *dev, struct clk *clk);
803
804/*
805 * The remaining APIs are optional for machine class support.
806 */
807
808
809/**
810 * clk_round_rate - adjust a rate to the exact rate a clock can provide
811 * @clk: clock source
812 * @rate: desired clock rate in Hz
813 *
814 * This answers the question "if I were to pass @rate to clk_set_rate(),
815 * what clock rate would I end up with?" without changing the hardware
816 * in any way. In other words:
817 *
818 * rate = clk_round_rate(clk, r);
819 *
820 * and:
821 *
822 * clk_set_rate(clk, r);
823 * rate = clk_get_rate(clk);
824 *
825 * are equivalent except the former does not modify the clock hardware
826 * in any way.
827 *
828 * Returns rounded clock rate in Hz, or negative errno.
829 */
830long clk_round_rate(struct clk *clk, unsigned long rate);
831
832/**
833 * clk_set_rate - set the clock rate for a clock source
834 * @clk: clock source
835 * @rate: desired clock rate in Hz
836 *
837 * Updating the rate starts at the top-most affected clock and then
838 * walks the tree down to the bottom-most clock that needs updating.
839 *
840 * Returns success (0) or negative errno.
841 */
842int clk_set_rate(struct clk *clk, unsigned long rate);
843
844/**
845 * clk_set_rate_exclusive- set the clock rate and claim exclusivity over
846 * clock source
847 * @clk: clock source
848 * @rate: desired clock rate in Hz
849 *
850 * This helper function allows drivers to atomically set the rate of a producer
851 * and claim exclusivity over the rate control of the producer.
852 *
853 * It is essentially a combination of clk_set_rate() and
854 * clk_rate_exclusite_get(). Caller must balance this call with a call to
855 * clk_rate_exclusive_put()
856 *
857 * Returns success (0) or negative errno.
858 */
859int clk_set_rate_exclusive(struct clk *clk, unsigned long rate);
860
861/**
862 * clk_has_parent - check if a clock is a possible parent for another
863 * @clk: clock source
864 * @parent: parent clock source
865 *
866 * This function can be used in drivers that need to check that a clock can be
867 * the parent of another without actually changing the parent.
868 *
869 * Returns true if @parent is a possible parent for @clk, false otherwise.
870 */
871bool clk_has_parent(const struct clk *clk, const struct clk *parent);
872
873/**
874 * clk_set_rate_range - set a rate range for a clock source
875 * @clk: clock source
876 * @min: desired minimum clock rate in Hz, inclusive
877 * @max: desired maximum clock rate in Hz, inclusive
878 *
879 * Returns success (0) or negative errno.
880 */
881int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max);
882
883/**
884 * clk_set_min_rate - set a minimum clock rate for a clock source
885 * @clk: clock source
886 * @rate: desired minimum clock rate in Hz, inclusive
887 *
888 * Returns success (0) or negative errno.
889 */
890int clk_set_min_rate(struct clk *clk, unsigned long rate);
891
892/**
893 * clk_set_max_rate - set a maximum clock rate for a clock source
894 * @clk: clock source
895 * @rate: desired maximum clock rate in Hz, inclusive
896 *
897 * Returns success (0) or negative errno.
898 */
899int clk_set_max_rate(struct clk *clk, unsigned long rate);
900
901/**
902 * clk_set_parent - set the parent clock source for this clock
903 * @clk: clock source
904 * @parent: parent clock source
905 *
906 * Returns success (0) or negative errno.
907 */
908int clk_set_parent(struct clk *clk, struct clk *parent);
909
910/**
911 * clk_get_parent - get the parent clock source for this clock
912 * @clk: clock source
913 *
914 * Returns struct clk corresponding to parent clock source, or
915 * valid IS_ERR() condition containing errno.
916 */
917struct clk *clk_get_parent(struct clk *clk);
918
919/**
920 * clk_get_sys - get a clock based upon the device name
921 * @dev_id: device name
922 * @con_id: connection ID
923 *
924 * Returns a struct clk corresponding to the clock producer, or
925 * valid IS_ERR() condition containing errno. The implementation
926 * uses @dev_id and @con_id to determine the clock consumer, and
927 * thereby the clock producer. In contrast to clk_get() this function
928 * takes the device name instead of the device itself for identification.
929 *
930 * Drivers must assume that the clock source is not enabled.
931 *
932 * clk_get_sys should not be called from within interrupt context.
933 */
934struct clk *clk_get_sys(const char *dev_id, const char *con_id);
935
936/**
937 * clk_save_context - save clock context for poweroff
938 *
939 * Saves the context of the clock register for powerstates in which the
940 * contents of the registers will be lost. Occurs deep within the suspend
941 * code so locking is not necessary.
942 */
943int clk_save_context(void);
944
945/**
946 * clk_restore_context - restore clock context after poweroff
947 *
948 * This occurs with all clocks enabled. Occurs deep within the resume code
949 * so locking is not necessary.
950 */
951void clk_restore_context(void);
952
953#else /* !CONFIG_HAVE_CLK */
954
955static inline struct clk *clk_get(struct device *dev, const char *id)
956{
957 return NULL;
958}
959
960static inline int __must_check clk_bulk_get(struct device *dev, int num_clks,
961 struct clk_bulk_data *clks)
962{
963 return 0;
964}
965
966static inline int __must_check clk_bulk_get_optional(struct device *dev,
967 int num_clks, struct clk_bulk_data *clks)
968{
969 return 0;
970}
971
972static inline int __must_check clk_bulk_get_all(struct device *dev,
973 struct clk_bulk_data **clks)
974{
975 return 0;
976}
977
978static inline struct clk *devm_clk_get(struct device *dev, const char *id)
979{
980 return NULL;
981}
982
983static inline struct clk *devm_clk_get_prepared(struct device *dev,
984 const char *id)
985{
986 return NULL;
987}
988
989static inline struct clk *devm_clk_get_enabled(struct device *dev,
990 const char *id)
991{
992 return NULL;
993}
994
995static inline struct clk *devm_clk_get_optional(struct device *dev,
996 const char *id)
997{
998 return NULL;
999}
1000
1001static inline struct clk *devm_clk_get_optional_prepared(struct device *dev,
1002 const char *id)
1003{
1004 return NULL;
1005}
1006
1007static inline struct clk *devm_clk_get_optional_enabled(struct device *dev,
1008 const char *id)
1009{
1010 return NULL;
1011}
1012
1013static inline struct clk *
1014devm_clk_get_optional_enabled_with_rate(struct device *dev, const char *id,
1015 unsigned long rate)
1016{
1017 return NULL;
1018}
1019
1020static inline int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
1021 struct clk_bulk_data *clks)
1022{
1023 return 0;
1024}
1025
1026static inline int __must_check devm_clk_bulk_get_optional(struct device *dev,
1027 int num_clks, struct clk_bulk_data *clks)
1028{
1029 return 0;
1030}
1031
1032static inline int __must_check devm_clk_bulk_get_all(struct device *dev,
1033 struct clk_bulk_data **clks)
1034{
1035
1036 return 0;
1037}
1038
1039static inline int __must_check devm_clk_bulk_get_all_enabled(struct device *dev,
1040 struct clk_bulk_data **clks)
1041{
1042 return 0;
1043}
1044
1045static inline struct clk *devm_get_clk_from_child(struct device *dev,
1046 struct device_node *np, const char *con_id)
1047{
1048 return NULL;
1049}
1050
1051static inline void clk_put(struct clk *clk) {}
1052
1053static inline void clk_bulk_put(int num_clks, struct clk_bulk_data *clks) {}
1054
1055static inline void clk_bulk_put_all(int num_clks, struct clk_bulk_data *clks) {}
1056
1057static inline void devm_clk_put(struct device *dev, struct clk *clk) {}
1058
1059static inline int clk_enable(struct clk *clk)
1060{
1061 return 0;
1062}
1063
1064static inline int __must_check clk_bulk_enable(int num_clks,
1065 const struct clk_bulk_data *clks)
1066{
1067 return 0;
1068}
1069
1070static inline void clk_disable(struct clk *clk) {}
1071
1072
1073static inline void clk_bulk_disable(int num_clks,
1074 const struct clk_bulk_data *clks) {}
1075
1076static inline unsigned long clk_get_rate(struct clk *clk)
1077{
1078 return 0;
1079}
1080
1081static inline int clk_set_rate(struct clk *clk, unsigned long rate)
1082{
1083 return 0;
1084}
1085
1086static inline int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
1087{
1088 return 0;
1089}
1090
1091static inline long clk_round_rate(struct clk *clk, unsigned long rate)
1092{
1093 return 0;
1094}
1095
1096static inline bool clk_has_parent(struct clk *clk, struct clk *parent)
1097{
1098 return true;
1099}
1100
1101static inline int clk_set_rate_range(struct clk *clk, unsigned long min,
1102 unsigned long max)
1103{
1104 return 0;
1105}
1106
1107static inline int clk_set_min_rate(struct clk *clk, unsigned long rate)
1108{
1109 return 0;
1110}
1111
1112static inline int clk_set_max_rate(struct clk *clk, unsigned long rate)
1113{
1114 return 0;
1115}
1116
1117static inline int clk_set_parent(struct clk *clk, struct clk *parent)
1118{
1119 return 0;
1120}
1121
1122static inline struct clk *clk_get_parent(struct clk *clk)
1123{
1124 return NULL;
1125}
1126
1127static inline struct clk *clk_get_sys(const char *dev_id, const char *con_id)
1128{
1129 return NULL;
1130}
1131
1132static inline int clk_save_context(void)
1133{
1134 return 0;
1135}
1136
1137static inline void clk_restore_context(void) {}
1138
1139#endif
1140
1141/* clk_prepare_enable helps cases using clk_enable in non-atomic context. */
1142static inline int clk_prepare_enable(struct clk *clk)
1143{
1144 int ret;
1145
1146 ret = clk_prepare(clk);
1147 if (ret)
1148 return ret;
1149 ret = clk_enable(clk);
1150 if (ret)
1151 clk_unprepare(clk);
1152
1153 return ret;
1154}
1155
1156/* clk_disable_unprepare helps cases using clk_disable in non-atomic context. */
1157static inline void clk_disable_unprepare(struct clk *clk)
1158{
1159 clk_disable(clk);
1160 clk_unprepare(clk);
1161}
1162
1163static inline int __must_check
1164clk_bulk_prepare_enable(int num_clks, const struct clk_bulk_data *clks)
1165{
1166 int ret;
1167
1168 ret = clk_bulk_prepare(num_clks, clks);
1169 if (ret)
1170 return ret;
1171 ret = clk_bulk_enable(num_clks, clks);
1172 if (ret)
1173 clk_bulk_unprepare(num_clks, clks);
1174
1175 return ret;
1176}
1177
1178static inline void clk_bulk_disable_unprepare(int num_clks,
1179 const struct clk_bulk_data *clks)
1180{
1181 clk_bulk_disable(num_clks, clks);
1182 clk_bulk_unprepare(num_clks, clks);
1183}
1184
1185/**
1186 * clk_drop_range - Reset any range set on that clock
1187 * @clk: clock source
1188 *
1189 * Returns success (0) or negative errno.
1190 */
1191static inline int clk_drop_range(struct clk *clk)
1192{
1193 return clk_set_rate_range(clk, min: 0, ULONG_MAX);
1194}
1195
1196/**
1197 * clk_get_optional - lookup and obtain a reference to an optional clock
1198 * producer.
1199 * @dev: device for clock "consumer"
1200 * @id: clock consumer ID
1201 *
1202 * Behaves the same as clk_get() except where there is no clock producer. In
1203 * this case, instead of returning -ENOENT, the function returns NULL.
1204 */
1205static inline struct clk *clk_get_optional(struct device *dev, const char *id)
1206{
1207 struct clk *clk = clk_get(dev, id);
1208
1209 if (clk == ERR_PTR(error: -ENOENT))
1210 return NULL;
1211
1212 return clk;
1213}
1214
1215#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
1216struct clk *of_clk_get(struct device_node *np, int index);
1217struct clk *of_clk_get_by_name(struct device_node *np, const char *name);
1218struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec);
1219#else
1220static inline struct clk *of_clk_get(struct device_node *np, int index)
1221{
1222 return ERR_PTR(-ENOENT);
1223}
1224static inline struct clk *of_clk_get_by_name(struct device_node *np,
1225 const char *name)
1226{
1227 return ERR_PTR(-ENOENT);
1228}
1229static inline struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
1230{
1231 return ERR_PTR(-ENOENT);
1232}
1233#endif
1234
1235#endif
1236

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

Morty Proxy This is a proxified and sanitized view of the page, visit original site.