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
16 struct device;
17 struct clk;
18 struct device_node;
19 struct 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 */
54 struct 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 */
71 struct 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 */
87 struct 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 */
103 int 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 */
110 int 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 */
120 int 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 */
131 long 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 */
141 int 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 */
150 int 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 */
161 int 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 */
171 int 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 */
184 bool 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 */
202 int 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 */
214 int 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 */
229 void clk_rate_exclusive_put(struct clk *clk);
230
231 #else
232
clk_notifier_register(struct clk * clk,struct notifier_block * nb)233 static inline int clk_notifier_register(struct clk *clk,
234 struct notifier_block *nb)
235 {
236 return -ENOTSUPP;
237 }
238
clk_notifier_unregister(struct clk * clk,struct notifier_block * nb)239 static inline int clk_notifier_unregister(struct clk *clk,
240 struct notifier_block *nb)
241 {
242 return -ENOTSUPP;
243 }
244
devm_clk_notifier_register(struct device * dev,struct clk * clk,struct notifier_block * nb)245 static inline int devm_clk_notifier_register(struct device *dev,
246 struct clk *clk,
247 struct notifier_block *nb)
248 {
249 return -ENOTSUPP;
250 }
251
clk_get_accuracy(struct clk * clk)252 static inline long clk_get_accuracy(struct clk *clk)
253 {
254 return -ENOTSUPP;
255 }
256
clk_set_phase(struct clk * clk,int phase)257 static inline long clk_set_phase(struct clk *clk, int phase)
258 {
259 return -ENOTSUPP;
260 }
261
clk_get_phase(struct clk * clk)262 static inline long clk_get_phase(struct clk *clk)
263 {
264 return -ENOTSUPP;
265 }
266
clk_set_duty_cycle(struct clk * clk,unsigned int num,unsigned int den)267 static inline int clk_set_duty_cycle(struct clk *clk, unsigned int num,
268 unsigned int den)
269 {
270 return -ENOTSUPP;
271 }
272
clk_get_scaled_duty_cycle(struct clk * clk,unsigned int scale)273 static inline unsigned int clk_get_scaled_duty_cycle(struct clk *clk,
274 unsigned int scale)
275 {
276 return 0;
277 }
278
clk_is_match(const struct clk * p,const struct clk * q)279 static inline bool clk_is_match(const struct clk *p, const struct clk *q)
280 {
281 return p == q;
282 }
283
clk_rate_exclusive_get(struct clk * clk)284 static inline int clk_rate_exclusive_get(struct clk *clk)
285 {
286 return 0;
287 }
288
devm_clk_rate_exclusive_get(struct device * dev,struct clk * clk)289 static inline int devm_clk_rate_exclusive_get(struct device *dev, struct clk *clk)
290 {
291 return 0;
292 }
293
clk_rate_exclusive_put(struct clk * clk)294 static 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 */
307 int clk_prepare(struct clk *clk);
308 int __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 */
326 bool clk_is_enabled_when_prepared(struct clk *clk);
327 #else
clk_prepare(struct clk * clk)328 static inline int clk_prepare(struct clk *clk)
329 {
330 might_sleep();
331 return 0;
332 }
333
334 static inline int __must_check
clk_bulk_prepare(int num_clks,const struct clk_bulk_data * clks)335 clk_bulk_prepare(int num_clks, const struct clk_bulk_data *clks)
336 {
337 might_sleep();
338 return 0;
339 }
340
clk_is_enabled_when_prepared(struct clk * clk)341 static 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
357 void clk_unprepare(struct clk *clk);
358 void clk_bulk_unprepare(int num_clks, const struct clk_bulk_data *clks);
359 #else
clk_unprepare(struct clk * clk)360 static inline void clk_unprepare(struct clk *clk)
361 {
362 might_sleep();
363 }
clk_bulk_unprepare(int num_clks,const struct clk_bulk_data * clks)364 static 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 */
387 struct 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 */
409 int __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 */
429 int __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 */
442 int __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 */
456 int __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 */
479 int __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
495 int __must_check devm_clk_bulk_get_all(struct device *dev,
496 struct clk_bulk_data **clks);
497
498 /**
499 * devm_clk_bulk_get_all_enable - 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 success (0) or negative errno.
504 *
505 * This helper function allows drivers to get all clocks of the
506 * consumer and enables them in one operation with management.
507 * The clks will automatically be disabled and freed when the device
508 * is unbound.
509 */
510
511 int __must_check devm_clk_bulk_get_all_enable(struct device *dev,
512 struct clk_bulk_data **clks);
513
514 /**
515 * devm_clk_get - lookup and obtain a managed reference to a clock producer.
516 * @dev: device for clock "consumer"
517 * @id: clock consumer ID
518 *
519 * Context: May sleep.
520 *
521 * Return: a struct clk corresponding to the clock producer, or
522 * valid IS_ERR() condition containing errno. The implementation
523 * uses @dev and @id to determine the clock consumer, and thereby
524 * the clock producer. (IOW, @id may be identical strings, but
525 * clk_get may return different clock producers depending on @dev.)
526 *
527 * Drivers must assume that the clock source is neither prepared nor
528 * enabled.
529 *
530 * The clock will automatically be freed when the device is unbound
531 * from the bus.
532 */
533 struct clk *devm_clk_get(struct device *dev, const char *id);
534
535 /**
536 * devm_clk_get_prepared - devm_clk_get() + clk_prepare()
537 * @dev: device for clock "consumer"
538 * @id: clock consumer ID
539 *
540 * Context: May sleep.
541 *
542 * Return: a struct clk corresponding to the clock producer, or
543 * valid IS_ERR() condition containing errno. The implementation
544 * uses @dev and @id to determine the clock consumer, and thereby
545 * the clock producer. (IOW, @id may be identical strings, but
546 * clk_get may return different clock producers depending on @dev.)
547 *
548 * The returned clk (if valid) is prepared. Drivers must however assume
549 * that the clock is not enabled.
550 *
551 * The clock will automatically be unprepared and freed when the device
552 * is unbound from the bus.
553 */
554 struct clk *devm_clk_get_prepared(struct device *dev, const char *id);
555
556 /**
557 * devm_clk_get_enabled - devm_clk_get() + clk_prepare_enable()
558 * @dev: device for clock "consumer"
559 * @id: clock consumer ID
560 *
561 * Context: May sleep.
562 *
563 * Return: a struct clk corresponding to the clock producer, or
564 * valid IS_ERR() condition containing errno. The implementation
565 * uses @dev and @id to determine the clock consumer, and thereby
566 * the clock producer. (IOW, @id may be identical strings, but
567 * clk_get may return different clock producers depending on @dev.)
568 *
569 * The returned clk (if valid) is prepared and enabled.
570 *
571 * The clock will automatically be disabled, unprepared and freed
572 * when the device is unbound from the bus.
573 */
574 struct clk *devm_clk_get_enabled(struct device *dev, const char *id);
575
576 /**
577 * devm_clk_get_optional - lookup and obtain a managed reference to an optional
578 * clock producer.
579 * @dev: device for clock "consumer"
580 * @id: clock consumer ID
581 *
582 * Context: May sleep.
583 *
584 * Return: a struct clk corresponding to the clock producer, or
585 * valid IS_ERR() condition containing errno. The implementation
586 * uses @dev and @id to determine the clock consumer, and thereby
587 * the clock producer. If no such clk is found, it returns NULL
588 * which serves as a dummy clk. That's the only difference compared
589 * to devm_clk_get().
590 *
591 * Drivers must assume that the clock source is neither prepared nor
592 * enabled.
593 *
594 * The clock will automatically be freed when the device is unbound
595 * from the bus.
596 */
597 struct clk *devm_clk_get_optional(struct device *dev, const char *id);
598
599 /**
600 * devm_clk_get_optional_prepared - devm_clk_get_optional() + clk_prepare()
601 * @dev: device for clock "consumer"
602 * @id: clock consumer ID
603 *
604 * Context: May sleep.
605 *
606 * Return: a struct clk corresponding to the clock producer, or
607 * valid IS_ERR() condition containing errno. The implementation
608 * uses @dev and @id to determine the clock consumer, and thereby
609 * the clock producer. If no such clk is found, it returns NULL
610 * which serves as a dummy clk. That's the only difference compared
611 * to devm_clk_get_prepared().
612 *
613 * The returned clk (if valid) is prepared. Drivers must however
614 * assume that the clock is not enabled.
615 *
616 * The clock will automatically be unprepared and freed when the
617 * device is unbound from the bus.
618 */
619 struct clk *devm_clk_get_optional_prepared(struct device *dev, const char *id);
620
621 /**
622 * devm_clk_get_optional_enabled - devm_clk_get_optional() +
623 * clk_prepare_enable()
624 * @dev: device for clock "consumer"
625 * @id: clock consumer ID
626 *
627 * Context: May sleep.
628 *
629 * Return: a struct clk corresponding to the clock producer, or
630 * valid IS_ERR() condition containing errno. The implementation
631 * uses @dev and @id to determine the clock consumer, and thereby
632 * the clock producer. If no such clk is found, it returns NULL
633 * which serves as a dummy clk. That's the only difference compared
634 * to devm_clk_get_enabled().
635 *
636 * The returned clk (if valid) is prepared and enabled.
637 *
638 * The clock will automatically be disabled, unprepared and freed
639 * when the device is unbound from the bus.
640 */
641 struct clk *devm_clk_get_optional_enabled(struct device *dev, const char *id);
642
643 /**
644 * devm_get_clk_from_child - lookup and obtain a managed reference to a
645 * clock producer from child node.
646 * @dev: device for clock "consumer"
647 * @np: pointer to clock consumer node
648 * @con_id: clock consumer ID
649 *
650 * This function parses the clocks, and uses them to look up the
651 * struct clk from the registered list of clock providers by using
652 * @np and @con_id
653 *
654 * The clock will automatically be freed when the device is unbound
655 * from the bus.
656 */
657 struct clk *devm_get_clk_from_child(struct device *dev,
658 struct device_node *np, const char *con_id);
659
660 /**
661 * clk_enable - inform the system when the clock source should be running.
662 * @clk: clock source
663 *
664 * If the clock can not be enabled/disabled, this should return success.
665 *
666 * May be called from atomic contexts.
667 *
668 * Returns success (0) or negative errno.
669 */
670 int clk_enable(struct clk *clk);
671
672 /**
673 * clk_bulk_enable - inform the system when the set of clks should be running.
674 * @num_clks: the number of clk_bulk_data
675 * @clks: the clk_bulk_data table of consumer
676 *
677 * May be called from atomic contexts.
678 *
679 * Returns success (0) or negative errno.
680 */
681 int __must_check clk_bulk_enable(int num_clks,
682 const struct clk_bulk_data *clks);
683
684 /**
685 * clk_disable - inform the system when the clock source is no longer required.
686 * @clk: clock source
687 *
688 * Inform the system that a clock source is no longer required by
689 * a driver and may be shut down.
690 *
691 * May be called from atomic contexts.
692 *
693 * Implementation detail: if the clock source is shared between
694 * multiple drivers, clk_enable() calls must be balanced by the
695 * same number of clk_disable() calls for the clock source to be
696 * disabled.
697 */
698 void clk_disable(struct clk *clk);
699
700 /**
701 * clk_bulk_disable - inform the system when the set of clks is no
702 * longer required.
703 * @num_clks: the number of clk_bulk_data
704 * @clks: the clk_bulk_data table of consumer
705 *
706 * Inform the system that a set of clks is no longer required by
707 * a driver and may be shut down.
708 *
709 * May be called from atomic contexts.
710 *
711 * Implementation detail: if the set of clks is shared between
712 * multiple drivers, clk_bulk_enable() calls must be balanced by the
713 * same number of clk_bulk_disable() calls for the clock source to be
714 * disabled.
715 */
716 void clk_bulk_disable(int num_clks, const struct clk_bulk_data *clks);
717
718 /**
719 * clk_get_rate - obtain the current clock rate (in Hz) for a clock source.
720 * This is only valid once the clock source has been enabled.
721 * @clk: clock source
722 */
723 unsigned long clk_get_rate(struct clk *clk);
724
725 /**
726 * clk_put - "free" the clock source
727 * @clk: clock source
728 *
729 * Note: drivers must ensure that all clk_enable calls made on this
730 * clock source are balanced by clk_disable calls prior to calling
731 * this function.
732 *
733 * clk_put should not be called from within interrupt context.
734 */
735 void clk_put(struct clk *clk);
736
737 /**
738 * clk_bulk_put - "free" the clock source
739 * @num_clks: the number of clk_bulk_data
740 * @clks: the clk_bulk_data table of consumer
741 *
742 * Note: drivers must ensure that all clk_bulk_enable calls made on this
743 * clock source are balanced by clk_bulk_disable calls prior to calling
744 * this function.
745 *
746 * clk_bulk_put should not be called from within interrupt context.
747 */
748 void clk_bulk_put(int num_clks, struct clk_bulk_data *clks);
749
750 /**
751 * clk_bulk_put_all - "free" all the clock source
752 * @num_clks: the number of clk_bulk_data
753 * @clks: the clk_bulk_data table of consumer
754 *
755 * Note: drivers must ensure that all clk_bulk_enable calls made on this
756 * clock source are balanced by clk_bulk_disable calls prior to calling
757 * this function.
758 *
759 * clk_bulk_put_all should not be called from within interrupt context.
760 */
761 void clk_bulk_put_all(int num_clks, struct clk_bulk_data *clks);
762
763 /**
764 * devm_clk_put - "free" a managed clock source
765 * @dev: device used to acquire the clock
766 * @clk: clock source acquired with devm_clk_get()
767 *
768 * Note: drivers must ensure that all clk_enable calls made on this
769 * clock source are balanced by clk_disable calls prior to calling
770 * this function.
771 *
772 * clk_put should not be called from within interrupt context.
773 */
774 void devm_clk_put(struct device *dev, struct clk *clk);
775
776 /*
777 * The remaining APIs are optional for machine class support.
778 */
779
780
781 /**
782 * clk_round_rate - adjust a rate to the exact rate a clock can provide
783 * @clk: clock source
784 * @rate: desired clock rate in Hz
785 *
786 * This answers the question "if I were to pass @rate to clk_set_rate(),
787 * what clock rate would I end up with?" without changing the hardware
788 * in any way. In other words:
789 *
790 * rate = clk_round_rate(clk, r);
791 *
792 * and:
793 *
794 * clk_set_rate(clk, r);
795 * rate = clk_get_rate(clk);
796 *
797 * are equivalent except the former does not modify the clock hardware
798 * in any way.
799 *
800 * Returns rounded clock rate in Hz, or negative errno.
801 */
802 long clk_round_rate(struct clk *clk, unsigned long rate);
803
804 /**
805 * clk_set_rate - set the clock rate for a clock source
806 * @clk: clock source
807 * @rate: desired clock rate in Hz
808 *
809 * Updating the rate starts at the top-most affected clock and then
810 * walks the tree down to the bottom-most clock that needs updating.
811 *
812 * Returns success (0) or negative errno.
813 */
814 int clk_set_rate(struct clk *clk, unsigned long rate);
815
816 /**
817 * clk_set_rate_exclusive- set the clock rate and claim exclusivity over
818 * clock source
819 * @clk: clock source
820 * @rate: desired clock rate in Hz
821 *
822 * This helper function allows drivers to atomically set the rate of a producer
823 * and claim exclusivity over the rate control of the producer.
824 *
825 * It is essentially a combination of clk_set_rate() and
826 * clk_rate_exclusite_get(). Caller must balance this call with a call to
827 * clk_rate_exclusive_put()
828 *
829 * Returns success (0) or negative errno.
830 */
831 int clk_set_rate_exclusive(struct clk *clk, unsigned long rate);
832
833 /**
834 * clk_has_parent - check if a clock is a possible parent for another
835 * @clk: clock source
836 * @parent: parent clock source
837 *
838 * This function can be used in drivers that need to check that a clock can be
839 * the parent of another without actually changing the parent.
840 *
841 * Returns true if @parent is a possible parent for @clk, false otherwise.
842 */
843 bool clk_has_parent(const struct clk *clk, const struct clk *parent);
844
845 /**
846 * clk_set_rate_range - set a rate range for a clock source
847 * @clk: clock source
848 * @min: desired minimum clock rate in Hz, inclusive
849 * @max: desired maximum clock rate in Hz, inclusive
850 *
851 * Returns success (0) or negative errno.
852 */
853 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max);
854
855 /**
856 * clk_set_min_rate - set a minimum clock rate for a clock source
857 * @clk: clock source
858 * @rate: desired minimum clock rate in Hz, inclusive
859 *
860 * Returns success (0) or negative errno.
861 */
862 int clk_set_min_rate(struct clk *clk, unsigned long rate);
863
864 /**
865 * clk_set_max_rate - set a maximum clock rate for a clock source
866 * @clk: clock source
867 * @rate: desired maximum clock rate in Hz, inclusive
868 *
869 * Returns success (0) or negative errno.
870 */
871 int clk_set_max_rate(struct clk *clk, unsigned long rate);
872
873 /**
874 * clk_set_parent - set the parent clock source for this clock
875 * @clk: clock source
876 * @parent: parent clock source
877 *
878 * Returns success (0) or negative errno.
879 */
880 int clk_set_parent(struct clk *clk, struct clk *parent);
881
882 /**
883 * clk_get_parent - get the parent clock source for this clock
884 * @clk: clock source
885 *
886 * Returns struct clk corresponding to parent clock source, or
887 * valid IS_ERR() condition containing errno.
888 */
889 struct clk *clk_get_parent(struct clk *clk);
890
891 /**
892 * clk_get_sys - get a clock based upon the device name
893 * @dev_id: device name
894 * @con_id: connection ID
895 *
896 * Returns a struct clk corresponding to the clock producer, or
897 * valid IS_ERR() condition containing errno. The implementation
898 * uses @dev_id and @con_id to determine the clock consumer, and
899 * thereby the clock producer. In contrast to clk_get() this function
900 * takes the device name instead of the device itself for identification.
901 *
902 * Drivers must assume that the clock source is not enabled.
903 *
904 * clk_get_sys should not be called from within interrupt context.
905 */
906 struct clk *clk_get_sys(const char *dev_id, const char *con_id);
907
908 /**
909 * clk_save_context - save clock context for poweroff
910 *
911 * Saves the context of the clock register for powerstates in which the
912 * contents of the registers will be lost. Occurs deep within the suspend
913 * code so locking is not necessary.
914 */
915 int clk_save_context(void);
916
917 /**
918 * clk_restore_context - restore clock context after poweroff
919 *
920 * This occurs with all clocks enabled. Occurs deep within the resume code
921 * so locking is not necessary.
922 */
923 void clk_restore_context(void);
924
925 #else /* !CONFIG_HAVE_CLK */
926
clk_get(struct device * dev,const char * id)927 static inline struct clk *clk_get(struct device *dev, const char *id)
928 {
929 return NULL;
930 }
931
clk_bulk_get(struct device * dev,int num_clks,struct clk_bulk_data * clks)932 static inline int __must_check clk_bulk_get(struct device *dev, int num_clks,
933 struct clk_bulk_data *clks)
934 {
935 return 0;
936 }
937
clk_bulk_get_optional(struct device * dev,int num_clks,struct clk_bulk_data * clks)938 static inline int __must_check clk_bulk_get_optional(struct device *dev,
939 int num_clks, struct clk_bulk_data *clks)
940 {
941 return 0;
942 }
943
clk_bulk_get_all(struct device * dev,struct clk_bulk_data ** clks)944 static inline int __must_check clk_bulk_get_all(struct device *dev,
945 struct clk_bulk_data **clks)
946 {
947 return 0;
948 }
949
devm_clk_get(struct device * dev,const char * id)950 static inline struct clk *devm_clk_get(struct device *dev, const char *id)
951 {
952 return NULL;
953 }
954
devm_clk_get_prepared(struct device * dev,const char * id)955 static inline struct clk *devm_clk_get_prepared(struct device *dev,
956 const char *id)
957 {
958 return NULL;
959 }
960
devm_clk_get_enabled(struct device * dev,const char * id)961 static inline struct clk *devm_clk_get_enabled(struct device *dev,
962 const char *id)
963 {
964 return NULL;
965 }
966
devm_clk_get_optional(struct device * dev,const char * id)967 static inline struct clk *devm_clk_get_optional(struct device *dev,
968 const char *id)
969 {
970 return NULL;
971 }
972
devm_clk_get_optional_prepared(struct device * dev,const char * id)973 static inline struct clk *devm_clk_get_optional_prepared(struct device *dev,
974 const char *id)
975 {
976 return NULL;
977 }
978
devm_clk_get_optional_enabled(struct device * dev,const char * id)979 static inline struct clk *devm_clk_get_optional_enabled(struct device *dev,
980 const char *id)
981 {
982 return NULL;
983 }
984
devm_clk_bulk_get(struct device * dev,int num_clks,struct clk_bulk_data * clks)985 static inline int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
986 struct clk_bulk_data *clks)
987 {
988 return 0;
989 }
990
devm_clk_bulk_get_optional(struct device * dev,int num_clks,struct clk_bulk_data * clks)991 static inline int __must_check devm_clk_bulk_get_optional(struct device *dev,
992 int num_clks, struct clk_bulk_data *clks)
993 {
994 return 0;
995 }
996
devm_clk_bulk_get_all(struct device * dev,struct clk_bulk_data ** clks)997 static inline int __must_check devm_clk_bulk_get_all(struct device *dev,
998 struct clk_bulk_data **clks)
999 {
1000
1001 return 0;
1002 }
1003
devm_clk_bulk_get_all_enable(struct device * dev,struct clk_bulk_data ** clks)1004 static inline int __must_check devm_clk_bulk_get_all_enable(struct device *dev,
1005 struct clk_bulk_data **clks)
1006 {
1007 return 0;
1008 }
1009
devm_get_clk_from_child(struct device * dev,struct device_node * np,const char * con_id)1010 static inline struct clk *devm_get_clk_from_child(struct device *dev,
1011 struct device_node *np, const char *con_id)
1012 {
1013 return NULL;
1014 }
1015
clk_put(struct clk * clk)1016 static inline void clk_put(struct clk *clk) {}
1017
clk_bulk_put(int num_clks,struct clk_bulk_data * clks)1018 static inline void clk_bulk_put(int num_clks, struct clk_bulk_data *clks) {}
1019
clk_bulk_put_all(int num_clks,struct clk_bulk_data * clks)1020 static inline void clk_bulk_put_all(int num_clks, struct clk_bulk_data *clks) {}
1021
devm_clk_put(struct device * dev,struct clk * clk)1022 static inline void devm_clk_put(struct device *dev, struct clk *clk) {}
1023
clk_enable(struct clk * clk)1024 static inline int clk_enable(struct clk *clk)
1025 {
1026 return 0;
1027 }
1028
clk_bulk_enable(int num_clks,const struct clk_bulk_data * clks)1029 static inline int __must_check clk_bulk_enable(int num_clks,
1030 const struct clk_bulk_data *clks)
1031 {
1032 return 0;
1033 }
1034
clk_disable(struct clk * clk)1035 static inline void clk_disable(struct clk *clk) {}
1036
1037
clk_bulk_disable(int num_clks,const struct clk_bulk_data * clks)1038 static inline void clk_bulk_disable(int num_clks,
1039 const struct clk_bulk_data *clks) {}
1040
clk_get_rate(struct clk * clk)1041 static inline unsigned long clk_get_rate(struct clk *clk)
1042 {
1043 return 0;
1044 }
1045
clk_set_rate(struct clk * clk,unsigned long rate)1046 static inline int clk_set_rate(struct clk *clk, unsigned long rate)
1047 {
1048 return 0;
1049 }
1050
clk_set_rate_exclusive(struct clk * clk,unsigned long rate)1051 static inline int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
1052 {
1053 return 0;
1054 }
1055
clk_round_rate(struct clk * clk,unsigned long rate)1056 static inline long clk_round_rate(struct clk *clk, unsigned long rate)
1057 {
1058 return 0;
1059 }
1060
clk_has_parent(struct clk * clk,struct clk * parent)1061 static inline bool clk_has_parent(struct clk *clk, struct clk *parent)
1062 {
1063 return true;
1064 }
1065
clk_set_rate_range(struct clk * clk,unsigned long min,unsigned long max)1066 static inline int clk_set_rate_range(struct clk *clk, unsigned long min,
1067 unsigned long max)
1068 {
1069 return 0;
1070 }
1071
clk_set_min_rate(struct clk * clk,unsigned long rate)1072 static inline int clk_set_min_rate(struct clk *clk, unsigned long rate)
1073 {
1074 return 0;
1075 }
1076
clk_set_max_rate(struct clk * clk,unsigned long rate)1077 static inline int clk_set_max_rate(struct clk *clk, unsigned long rate)
1078 {
1079 return 0;
1080 }
1081
clk_set_parent(struct clk * clk,struct clk * parent)1082 static inline int clk_set_parent(struct clk *clk, struct clk *parent)
1083 {
1084 return 0;
1085 }
1086
clk_get_parent(struct clk * clk)1087 static inline struct clk *clk_get_parent(struct clk *clk)
1088 {
1089 return NULL;
1090 }
1091
clk_get_sys(const char * dev_id,const char * con_id)1092 static inline struct clk *clk_get_sys(const char *dev_id, const char *con_id)
1093 {
1094 return NULL;
1095 }
1096
clk_save_context(void)1097 static inline int clk_save_context(void)
1098 {
1099 return 0;
1100 }
1101
clk_restore_context(void)1102 static inline void clk_restore_context(void) {}
1103
1104 #endif
1105
1106 /* clk_prepare_enable helps cases using clk_enable in non-atomic context. */
clk_prepare_enable(struct clk * clk)1107 static inline int clk_prepare_enable(struct clk *clk)
1108 {
1109 int ret;
1110
1111 ret = clk_prepare(clk);
1112 if (ret)
1113 return ret;
1114 ret = clk_enable(clk);
1115 if (ret)
1116 clk_unprepare(clk);
1117
1118 return ret;
1119 }
1120
1121 /* clk_disable_unprepare helps cases using clk_disable in non-atomic context. */
clk_disable_unprepare(struct clk * clk)1122 static inline void clk_disable_unprepare(struct clk *clk)
1123 {
1124 clk_disable(clk);
1125 clk_unprepare(clk);
1126 }
1127
1128 static inline int __must_check
clk_bulk_prepare_enable(int num_clks,const struct clk_bulk_data * clks)1129 clk_bulk_prepare_enable(int num_clks, const struct clk_bulk_data *clks)
1130 {
1131 int ret;
1132
1133 ret = clk_bulk_prepare(num_clks, clks);
1134 if (ret)
1135 return ret;
1136 ret = clk_bulk_enable(num_clks, clks);
1137 if (ret)
1138 clk_bulk_unprepare(num_clks, clks);
1139
1140 return ret;
1141 }
1142
clk_bulk_disable_unprepare(int num_clks,const struct clk_bulk_data * clks)1143 static inline void clk_bulk_disable_unprepare(int num_clks,
1144 const struct clk_bulk_data *clks)
1145 {
1146 clk_bulk_disable(num_clks, clks);
1147 clk_bulk_unprepare(num_clks, clks);
1148 }
1149
1150 /**
1151 * clk_drop_range - Reset any range set on that clock
1152 * @clk: clock source
1153 *
1154 * Returns success (0) or negative errno.
1155 */
clk_drop_range(struct clk * clk)1156 static inline int clk_drop_range(struct clk *clk)
1157 {
1158 return clk_set_rate_range(clk, 0, ULONG_MAX);
1159 }
1160
1161 /**
1162 * clk_get_optional - lookup and obtain a reference to an optional clock
1163 * producer.
1164 * @dev: device for clock "consumer"
1165 * @id: clock consumer ID
1166 *
1167 * Behaves the same as clk_get() except where there is no clock producer. In
1168 * this case, instead of returning -ENOENT, the function returns NULL.
1169 */
clk_get_optional(struct device * dev,const char * id)1170 static inline struct clk *clk_get_optional(struct device *dev, const char *id)
1171 {
1172 struct clk *clk = clk_get(dev, id);
1173
1174 if (clk == ERR_PTR(-ENOENT))
1175 return NULL;
1176
1177 return clk;
1178 }
1179
1180 #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
1181 struct clk *of_clk_get(struct device_node *np, int index);
1182 struct clk *of_clk_get_by_name(struct device_node *np, const char *name);
1183 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec);
1184 #else
of_clk_get(struct device_node * np,int index)1185 static inline struct clk *of_clk_get(struct device_node *np, int index)
1186 {
1187 return ERR_PTR(-ENOENT);
1188 }
of_clk_get_by_name(struct device_node * np,const char * name)1189 static inline struct clk *of_clk_get_by_name(struct device_node *np,
1190 const char *name)
1191 {
1192 return ERR_PTR(-ENOENT);
1193 }
of_clk_get_from_provider(struct of_phandle_args * clkspec)1194 static inline struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
1195 {
1196 return ERR_PTR(-ENOENT);
1197 }
1198 #endif
1199
1200 #endif
1201