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 * clk_get_accuracy - obtain the clock accuracy in ppb (parts per billion)
114 * for a clock source.
115 * @clk: clock source
116 *
117 * This gets the clock source accuracy expressed in ppb.
118 * A perfect clock returns 0.
119 */
120 long clk_get_accuracy(struct clk *clk);
121
122 /**
123 * clk_set_phase - adjust the phase shift of a clock signal
124 * @clk: clock signal source
125 * @degrees: number of degrees the signal is shifted
126 *
127 * Shifts the phase of a clock signal by the specified degrees. Returns 0 on
128 * success, -EERROR otherwise.
129 */
130 int clk_set_phase(struct clk *clk, int degrees);
131
132 /**
133 * clk_get_phase - return the phase shift of a clock signal
134 * @clk: clock signal source
135 *
136 * Returns the phase shift of a clock node in degrees, otherwise returns
137 * -EERROR.
138 */
139 int clk_get_phase(struct clk *clk);
140
141 /**
142 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
143 * @clk: clock signal source
144 * @num: numerator of the duty cycle ratio to be applied
145 * @den: denominator of the duty cycle ratio to be applied
146 *
147 * Adjust the duty cycle of a clock signal by the specified ratio. Returns 0 on
148 * success, -EERROR otherwise.
149 */
150 int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den);
151
152 /**
153 * clk_get_duty_cycle - return the duty cycle ratio of a clock signal
154 * @clk: clock signal source
155 * @scale: scaling factor to be applied to represent the ratio as an integer
156 *
157 * Returns the duty cycle ratio multiplied by the scale provided, otherwise
158 * returns -EERROR.
159 */
160 int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale);
161
162 /**
163 * clk_is_match - check if two clk's point to the same hardware clock
164 * @p: clk compared against q
165 * @q: clk compared against p
166 *
167 * Returns true if the two struct clk pointers both point to the same hardware
168 * clock node. Put differently, returns true if @p and @q
169 * share the same &struct clk_core object.
170 *
171 * Returns false otherwise. Note that two NULL clks are treated as matching.
172 */
173 bool clk_is_match(const struct clk *p, const struct clk *q);
174
175 #else
176
177 static inline int clk_notifier_register(struct clk *clk,
178 struct notifier_block *nb)
179 {
180 return -ENOTSUPP;
181 }
182
183 static inline int clk_notifier_unregister(struct clk *clk,
184 struct notifier_block *nb)
185 {
186 return -ENOTSUPP;
187 }
188
189 static inline long clk_get_accuracy(struct clk *clk)
190 {
191 return -ENOTSUPP;
192 }
193
194 static inline long clk_set_phase(struct clk *clk, int phase)
195 {
196 return -ENOTSUPP;
197 }
198
199 static inline long clk_get_phase(struct clk *clk)
200 {
201 return -ENOTSUPP;
202 }
203
204 static inline int clk_set_duty_cycle(struct clk *clk, unsigned int num,
205 unsigned int den)
206 {
207 return -ENOTSUPP;
208 }
209
210 static inline unsigned int clk_get_scaled_duty_cycle(struct clk *clk,
211 unsigned int scale)
212 {
213 return 0;
214 }
215
216 static inline bool clk_is_match(const struct clk *p, const struct clk *q)
217 {
218 return p == q;
219 }
220
221 #endif
222
223 /**
224 * clk_prepare - prepare a clock source
225 * @clk: clock source
226 *
227 * This prepares the clock source for use.
228 *
229 * Must not be called from within atomic context.
230 */
231 #ifdef CONFIG_HAVE_CLK_PREPARE
232 int clk_prepare(struct clk *clk);
233 int __must_check clk_bulk_prepare(int num_clks,
234 const struct clk_bulk_data *clks);
235 #else
236 static inline int clk_prepare(struct clk *clk)
237 {
238 might_sleep();
239 return 0;
240 }
241
242 static inline int __must_check
243 clk_bulk_prepare(int num_clks, const struct clk_bulk_data *clks)
244 {
245 might_sleep();
246 return 0;
247 }
248 #endif
249
250 /**
251 * clk_unprepare - undo preparation of a clock source
252 * @clk: clock source
253 *
254 * This undoes a previously prepared clock. The caller must balance
255 * the number of prepare and unprepare calls.
256 *
257 * Must not be called from within atomic context.
258 */
259 #ifdef CONFIG_HAVE_CLK_PREPARE
260 void clk_unprepare(struct clk *clk);
261 void clk_bulk_unprepare(int num_clks, const struct clk_bulk_data *clks);
262 #else
263 static inline void clk_unprepare(struct clk *clk)
264 {
265 might_sleep();
266 }
267 static inline void clk_bulk_unprepare(int num_clks,
268 const struct clk_bulk_data *clks)
269 {
270 might_sleep();
271 }
272 #endif
273
274 #ifdef CONFIG_HAVE_CLK
275 /**
276 * clk_get - lookup and obtain a reference to a clock producer.
277 * @dev: device for clock "consumer"
278 * @id: clock consumer ID
279 *
280 * Returns a struct clk corresponding to the clock producer, or
281 * valid IS_ERR() condition containing errno. The implementation
282 * uses @dev and @id to determine the clock consumer, and thereby
283 * the clock producer. (IOW, @id may be identical strings, but
284 * clk_get may return different clock producers depending on @dev.)
285 *
286 * Drivers must assume that the clock source is not enabled.
287 *
288 * clk_get should not be called from within interrupt context.
289 */
290 struct clk *clk_get(struct device *dev, const char *id);
291
292 /**
293 * clk_bulk_get - lookup and obtain a number of references to clock producer.
294 * @dev: device for clock "consumer"
295 * @num_clks: the number of clk_bulk_data
296 * @clks: the clk_bulk_data table of consumer
297 *
298 * This helper function allows drivers to get several clk consumers in one
299 * operation. If any of the clk cannot be acquired then any clks
300 * that were obtained will be freed before returning to the caller.
301 *
302 * Returns 0 if all clocks specified in clk_bulk_data table are obtained
303 * successfully, or valid IS_ERR() condition containing errno.
304 * The implementation uses @dev and @clk_bulk_data.id to determine the
305 * clock consumer, and thereby the clock producer.
306 * The clock returned is stored in each @clk_bulk_data.clk field.
307 *
308 * Drivers must assume that the clock source is not enabled.
309 *
310 * clk_bulk_get should not be called from within interrupt context.
311 */
312 int __must_check clk_bulk_get(struct device *dev, int num_clks,
313 struct clk_bulk_data *clks);
314 /**
315 * clk_bulk_get_all - lookup and obtain all available references to clock
316 * producer.
317 * @dev: device for clock "consumer"
318 * @clks: pointer to the clk_bulk_data table of consumer
319 *
320 * This helper function allows drivers to get all clk consumers in one
321 * operation. If any of the clk cannot be acquired then any clks
322 * that were obtained will be freed before returning to the caller.
323 *
324 * Returns a positive value for the number of clocks obtained while the
325 * clock references are stored in the clk_bulk_data table in @clks field.
326 * Returns 0 if there're none and a negative value if something failed.
327 *
328 * Drivers must assume that the clock source is not enabled.
329 *
330 * clk_bulk_get should not be called from within interrupt context.
331 */
332 int __must_check clk_bulk_get_all(struct device *dev,
333 struct clk_bulk_data **clks);
334
335 /**
336 * clk_bulk_get_optional - lookup and obtain a number of references to clock producer
337 * @dev: device for clock "consumer"
338 * @num_clks: the number of clk_bulk_data
339 * @clks: the clk_bulk_data table of consumer
340 *
341 * Behaves the same as clk_bulk_get() except where there is no clock producer.
342 * In this case, instead of returning -ENOENT, the function returns 0 and
343 * NULL for a clk for which a clock producer could not be determined.
344 */
345 int __must_check clk_bulk_get_optional(struct device *dev, int num_clks,
346 struct clk_bulk_data *clks);
347 /**
348 * devm_clk_bulk_get - managed get multiple clk consumers
349 * @dev: device for clock "consumer"
350 * @num_clks: the number of clk_bulk_data
351 * @clks: the clk_bulk_data table of consumer
352 *
353 * Return 0 on success, an errno on failure.
354 *
355 * This helper function allows drivers to get several clk
356 * consumers in one operation with management, the clks will
357 * automatically be freed when the device is unbound.
358 */
359 int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
360 struct clk_bulk_data *clks);
361 /**
362 * devm_clk_bulk_get_optional - managed get multiple optional consumer clocks
363 * @dev: device for clock "consumer"
364 * @num_clks: the number of clk_bulk_data
365 * @clks: pointer to the clk_bulk_data table of consumer
366 *
367 * Behaves the same as devm_clk_bulk_get() except where there is no clock
368 * producer. In this case, instead of returning -ENOENT, the function returns
369 * NULL for given clk. It is assumed all clocks in clk_bulk_data are optional.
370 *
371 * Returns 0 if all clocks specified in clk_bulk_data table are obtained
372 * successfully or for any clk there was no clk provider available, otherwise
373 * returns valid IS_ERR() condition containing errno.
374 * The implementation uses @dev and @clk_bulk_data.id to determine the
375 * clock consumer, and thereby the clock producer.
376 * The clock returned is stored in each @clk_bulk_data.clk field.
377 *
378 * Drivers must assume that the clock source is not enabled.
379 *
380 * clk_bulk_get should not be called from within interrupt context.
381 */
382 int __must_check devm_clk_bulk_get_optional(struct device *dev, int num_clks,
383 struct clk_bulk_data *clks);
384 /**
385 * devm_clk_bulk_get_all - managed get multiple clk consumers
386 * @dev: device for clock "consumer"
387 * @clks: pointer to the clk_bulk_data table of consumer
388 *
389 * Returns a positive value for the number of clocks obtained while the
390 * clock references are stored in the clk_bulk_data table in @clks field.
391 * Returns 0 if there're none and a negative value if something failed.
392 *
393 * This helper function allows drivers to get several clk
394 * consumers in one operation with management, the clks will
395 * automatically be freed when the device is unbound.
396 */
397
398 int __must_check devm_clk_bulk_get_all(struct device *dev,
399 struct clk_bulk_data **clks);
400
401 /**
402 * devm_clk_get - lookup and obtain a managed reference to a clock producer.
403 * @dev: device for clock "consumer"
404 * @id: clock consumer ID
405 *
406 * Returns a struct clk corresponding to the clock producer, or
407 * valid IS_ERR() condition containing errno. The implementation
408 * uses @dev and @id to determine the clock consumer, and thereby
409 * the clock producer. (IOW, @id may be identical strings, but
410 * clk_get may return different clock producers depending on @dev.)
411 *
412 * Drivers must assume that the clock source is not enabled.
413 *
414 * devm_clk_get should not be called from within interrupt context.
415 *
416 * The clock will automatically be freed when the device is unbound
417 * from the bus.
418 */
419 struct clk *devm_clk_get(struct device *dev, const char *id);
420
421 /**
422 * devm_clk_get_optional - lookup and obtain a managed reference to an optional
423 * clock producer.
424 * @dev: device for clock "consumer"
425 * @id: clock consumer ID
426 *
427 * Behaves the same as devm_clk_get() except where there is no clock producer.
428 * In this case, instead of returning -ENOENT, the function returns NULL.
429 */
430 struct clk *devm_clk_get_optional(struct device *dev, const char *id);
431
432 /**
433 * devm_get_clk_from_child - lookup and obtain a managed reference to a
434 * clock producer from child node.
435 * @dev: device for clock "consumer"
436 * @np: pointer to clock consumer node
437 * @con_id: clock consumer ID
438 *
439 * This function parses the clocks, and uses them to look up the
440 * struct clk from the registered list of clock providers by using
441 * @np and @con_id
442 *
443 * The clock will automatically be freed when the device is unbound
444 * from the bus.
445 */
446 struct clk *devm_get_clk_from_child(struct device *dev,
447 struct device_node *np, const char *con_id);
448 /**
449 * clk_rate_exclusive_get - get exclusivity over the rate control of a
450 * producer
451 * @clk: clock source
452 *
453 * This function allows drivers to get exclusive control over the rate of a
454 * provider. It prevents any other consumer to execute, even indirectly,
455 * opereation which could alter the rate of the provider or cause glitches
456 *
457 * If exlusivity is claimed more than once on clock, even by the same driver,
458 * the rate effectively gets locked as exclusivity can't be preempted.
459 *
460 * Must not be called from within atomic context.
461 *
462 * Returns success (0) or negative errno.
463 */
464 int clk_rate_exclusive_get(struct clk *clk);
465
466 /**
467 * clk_rate_exclusive_put - release exclusivity over the rate control of a
468 * producer
469 * @clk: clock source
470 *
471 * This function allows drivers to release the exclusivity it previously got
472 * from clk_rate_exclusive_get()
473 *
474 * The caller must balance the number of clk_rate_exclusive_get() and
475 * clk_rate_exclusive_put() calls.
476 *
477 * Must not be called from within atomic context.
478 */
479 void clk_rate_exclusive_put(struct clk *clk);
480
481 /**
482 * clk_enable - inform the system when the clock source should be running.
483 * @clk: clock source
484 *
485 * If the clock can not be enabled/disabled, this should return success.
486 *
487 * May be called from atomic contexts.
488 *
489 * Returns success (0) or negative errno.
490 */
491 int clk_enable(struct clk *clk);
492
493 /**
494 * clk_bulk_enable - inform the system when the set of clks should be running.
495 * @num_clks: the number of clk_bulk_data
496 * @clks: the clk_bulk_data table of consumer
497 *
498 * May be called from atomic contexts.
499 *
500 * Returns success (0) or negative errno.
501 */
502 int __must_check clk_bulk_enable(int num_clks,
503 const struct clk_bulk_data *clks);
504
505 /**
506 * clk_disable - inform the system when the clock source is no longer required.
507 * @clk: clock source
508 *
509 * Inform the system that a clock source is no longer required by
510 * a driver and may be shut down.
511 *
512 * May be called from atomic contexts.
513 *
514 * Implementation detail: if the clock source is shared between
515 * multiple drivers, clk_enable() calls must be balanced by the
516 * same number of clk_disable() calls for the clock source to be
517 * disabled.
518 */
519 void clk_disable(struct clk *clk);
520
521 /**
522 * clk_bulk_disable - inform the system when the set of clks is no
523 * longer required.
524 * @num_clks: the number of clk_bulk_data
525 * @clks: the clk_bulk_data table of consumer
526 *
527 * Inform the system that a set of clks is no longer required by
528 * a driver and may be shut down.
529 *
530 * May be called from atomic contexts.
531 *
532 * Implementation detail: if the set of clks is shared between
533 * multiple drivers, clk_bulk_enable() calls must be balanced by the
534 * same number of clk_bulk_disable() calls for the clock source to be
535 * disabled.
536 */
537 void clk_bulk_disable(int num_clks, const struct clk_bulk_data *clks);
538
539 /**
540 * clk_get_rate - obtain the current clock rate (in Hz) for a clock source.
541 * This is only valid once the clock source has been enabled.
542 * @clk: clock source
543 */
544 unsigned long clk_get_rate(struct clk *clk);
545
546 /**
547 * clk_put - "free" the clock source
548 * @clk: clock source
549 *
550 * Note: drivers must ensure that all clk_enable calls made on this
551 * clock source are balanced by clk_disable calls prior to calling
552 * this function.
553 *
554 * clk_put should not be called from within interrupt context.
555 */
556 void clk_put(struct clk *clk);
557
558 /**
559 * clk_bulk_put - "free" the clock source
560 * @num_clks: the number of clk_bulk_data
561 * @clks: the clk_bulk_data table of consumer
562 *
563 * Note: drivers must ensure that all clk_bulk_enable calls made on this
564 * clock source are balanced by clk_bulk_disable calls prior to calling
565 * this function.
566 *
567 * clk_bulk_put should not be called from within interrupt context.
568 */
569 void clk_bulk_put(int num_clks, struct clk_bulk_data *clks);
570
571 /**
572 * clk_bulk_put_all - "free" all the clock source
573 * @num_clks: the number of clk_bulk_data
574 * @clks: the clk_bulk_data table of consumer
575 *
576 * Note: drivers must ensure that all clk_bulk_enable calls made on this
577 * clock source are balanced by clk_bulk_disable calls prior to calling
578 * this function.
579 *
580 * clk_bulk_put_all should not be called from within interrupt context.
581 */
582 void clk_bulk_put_all(int num_clks, struct clk_bulk_data *clks);
583
584 /**
585 * devm_clk_put - "free" a managed clock source
586 * @dev: device used to acquire the clock
587 * @clk: clock source acquired with devm_clk_get()
588 *
589 * Note: drivers must ensure that all clk_enable calls made on this
590 * clock source are balanced by clk_disable calls prior to calling
591 * this function.
592 *
593 * clk_put should not be called from within interrupt context.
594 */
595 void devm_clk_put(struct device *dev, struct clk *clk);
596
597 /*
598 * The remaining APIs are optional for machine class support.
599 */
600
601
602 /**
603 * clk_round_rate - adjust a rate to the exact rate a clock can provide
604 * @clk: clock source
605 * @rate: desired clock rate in Hz
606 *
607 * This answers the question "if I were to pass @rate to clk_set_rate(),
608 * what clock rate would I end up with?" without changing the hardware
609 * in any way. In other words:
610 *
611 * rate = clk_round_rate(clk, r);
612 *
613 * and:
614 *
615 * clk_set_rate(clk, r);
616 * rate = clk_get_rate(clk);
617 *
618 * are equivalent except the former does not modify the clock hardware
619 * in any way.
620 *
621 * Returns rounded clock rate in Hz, or negative errno.
622 */
623 long clk_round_rate(struct clk *clk, unsigned long rate);
624
625 /**
626 * clk_set_rate - set the clock rate for a clock source
627 * @clk: clock source
628 * @rate: desired clock rate in Hz
629 *
630 * Returns success (0) or negative errno.
631 */
632 int clk_set_rate(struct clk *clk, unsigned long rate);
633
634 /**
635 * clk_set_rate_exclusive- set the clock rate and claim exclusivity over
636 * clock source
637 * @clk: clock source
638 * @rate: desired clock rate in Hz
639 *
640 * This helper function allows drivers to atomically set the rate of a producer
641 * and claim exclusivity over the rate control of the producer.
642 *
643 * It is essentially a combination of clk_set_rate() and
644 * clk_rate_exclusite_get(). Caller must balance this call with a call to
645 * clk_rate_exclusive_put()
646 *
647 * Returns success (0) or negative errno.
648 */
649 int clk_set_rate_exclusive(struct clk *clk, unsigned long rate);
650
651 /**
652 * clk_has_parent - check if a clock is a possible parent for another
653 * @clk: clock source
654 * @parent: parent clock source
655 *
656 * This function can be used in drivers that need to check that a clock can be
657 * the parent of another without actually changing the parent.
658 *
659 * Returns true if @parent is a possible parent for @clk, false otherwise.
660 */
661 bool clk_has_parent(struct clk *clk, struct clk *parent);
662
663 /**
664 * clk_set_rate_range - set a rate range for a clock source
665 * @clk: clock source
666 * @min: desired minimum clock rate in Hz, inclusive
667 * @max: desired maximum clock rate in Hz, inclusive
668 *
669 * Returns success (0) or negative errno.
670 */
671 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max);
672
673 /**
674 * clk_set_min_rate - set a minimum clock rate for a clock source
675 * @clk: clock source
676 * @rate: desired minimum clock rate in Hz, inclusive
677 *
678 * Returns success (0) or negative errno.
679 */
680 int clk_set_min_rate(struct clk *clk, unsigned long rate);
681
682 /**
683 * clk_set_max_rate - set a maximum clock rate for a clock source
684 * @clk: clock source
685 * @rate: desired maximum clock rate in Hz, inclusive
686 *
687 * Returns success (0) or negative errno.
688 */
689 int clk_set_max_rate(struct clk *clk, unsigned long rate);
690
691 /**
692 * clk_set_parent - set the parent clock source for this clock
693 * @clk: clock source
694 * @parent: parent clock source
695 *
696 * Returns success (0) or negative errno.
697 */
698 int clk_set_parent(struct clk *clk, struct clk *parent);
699
700 /**
701 * clk_get_parent - get the parent clock source for this clock
702 * @clk: clock source
703 *
704 * Returns struct clk corresponding to parent clock source, or
705 * valid IS_ERR() condition containing errno.
706 */
707 struct clk *clk_get_parent(struct clk *clk);
708
709 /**
710 * clk_get_sys - get a clock based upon the device name
711 * @dev_id: device name
712 * @con_id: connection ID
713 *
714 * Returns a struct clk corresponding to the clock producer, or
715 * valid IS_ERR() condition containing errno. The implementation
716 * uses @dev_id and @con_id to determine the clock consumer, and
717 * thereby the clock producer. In contrast to clk_get() this function
718 * takes the device name instead of the device itself for identification.
719 *
720 * Drivers must assume that the clock source is not enabled.
721 *
722 * clk_get_sys should not be called from within interrupt context.
723 */
724 struct clk *clk_get_sys(const char *dev_id, const char *con_id);
725
726 /**
727 * clk_save_context - save clock context for poweroff
728 *
729 * Saves the context of the clock register for powerstates in which the
730 * contents of the registers will be lost. Occurs deep within the suspend
731 * code so locking is not necessary.
732 */
733 int clk_save_context(void);
734
735 /**
736 * clk_restore_context - restore clock context after poweroff
737 *
738 * This occurs with all clocks enabled. Occurs deep within the resume code
739 * so locking is not necessary.
740 */
741 void clk_restore_context(void);
742
743 #else /* !CONFIG_HAVE_CLK */
744
745 static inline struct clk *clk_get(struct device *dev, const char *id)
746 {
747 return NULL;
748 }
749
750 static inline int __must_check clk_bulk_get(struct device *dev, int num_clks,
751 struct clk_bulk_data *clks)
752 {
753 return 0;
754 }
755
756 static inline int __must_check clk_bulk_get_optional(struct device *dev,
757 int num_clks, struct clk_bulk_data *clks)
758 {
759 return 0;
760 }
761
762 static inline int __must_check clk_bulk_get_all(struct device *dev,
763 struct clk_bulk_data **clks)
764 {
765 return 0;
766 }
767
768 static inline struct clk *devm_clk_get(struct device *dev, const char *id)
769 {
770 return NULL;
771 }
772
773 static inline struct clk *devm_clk_get_optional(struct device *dev,
774 const char *id)
775 {
776 return NULL;
777 }
778
779 static inline int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
780 struct clk_bulk_data *clks)
781 {
782 return 0;
783 }
784
785 static inline int __must_check devm_clk_bulk_get_optional(struct device *dev,
786 int num_clks, struct clk_bulk_data *clks)
787 {
788 return 0;
789 }
790
791 static inline int __must_check devm_clk_bulk_get_all(struct device *dev,
792 struct clk_bulk_data **clks)
793 {
794
795 return 0;
796 }
797
798 static inline struct clk *devm_get_clk_from_child(struct device *dev,
799 struct device_node *np, const char *con_id)
800 {
801 return NULL;
802 }
803
804 static inline void clk_put(struct clk *clk) {}
805
806 static inline void clk_bulk_put(int num_clks, struct clk_bulk_data *clks) {}
807
808 static inline void clk_bulk_put_all(int num_clks, struct clk_bulk_data *clks) {}
809
810 static inline void devm_clk_put(struct device *dev, struct clk *clk) {}
811
812
813 static inline int clk_rate_exclusive_get(struct clk *clk)
814 {
815 return 0;
816 }
817
818 static inline void clk_rate_exclusive_put(struct clk *clk) {}
819
820 static inline int clk_enable(struct clk *clk)
821 {
822 return 0;
823 }
824
825 static inline int __must_check clk_bulk_enable(int num_clks,
826 const struct clk_bulk_data *clks)
827 {
828 return 0;
829 }
830
831 static inline void clk_disable(struct clk *clk) {}
832
833
834 static inline void clk_bulk_disable(int num_clks,
835 const struct clk_bulk_data *clks) {}
836
837 static inline unsigned long clk_get_rate(struct clk *clk)
838 {
839 return 0;
840 }
841
842 static inline int clk_set_rate(struct clk *clk, unsigned long rate)
843 {
844 return 0;
845 }
846
847 static inline int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
848 {
849 return 0;
850 }
851
852 static inline long clk_round_rate(struct clk *clk, unsigned long rate)
853 {
854 return 0;
855 }
856
857 static inline bool clk_has_parent(struct clk *clk, struct clk *parent)
858 {
859 return true;
860 }
861
862 static inline int clk_set_rate_range(struct clk *clk, unsigned long min,
863 unsigned long max)
864 {
865 return 0;
866 }
867
868 static inline int clk_set_min_rate(struct clk *clk, unsigned long rate)
869 {
870 return 0;
871 }
872
873 static inline int clk_set_max_rate(struct clk *clk, unsigned long rate)
874 {
875 return 0;
876 }
877
878 static inline int clk_set_parent(struct clk *clk, struct clk *parent)
879 {
880 return 0;
881 }
882
883 static inline struct clk *clk_get_parent(struct clk *clk)
884 {
885 return NULL;
886 }
887
888 static inline struct clk *clk_get_sys(const char *dev_id, const char *con_id)
889 {
890 return NULL;
891 }
892
893 static inline int clk_save_context(void)
894 {
895 return 0;
896 }
897
898 static inline void clk_restore_context(void) {}
899
900 #endif
901
902 /* clk_prepare_enable helps cases using clk_enable in non-atomic context. */
903 static inline int clk_prepare_enable(struct clk *clk)
904 {
905 int ret;
906
907 ret = clk_prepare(clk);
908 if (ret)
909 return ret;
910 ret = clk_enable(clk);
911 if (ret)
912 clk_unprepare(clk);
913
914 return ret;
915 }
916
917 /* clk_disable_unprepare helps cases using clk_disable in non-atomic context. */
918 static inline void clk_disable_unprepare(struct clk *clk)
919 {
920 clk_disable(clk);
921 clk_unprepare(clk);
922 }
923
924 static inline int __must_check
925 clk_bulk_prepare_enable(int num_clks, const struct clk_bulk_data *clks)
926 {
927 int ret;
928
929 ret = clk_bulk_prepare(num_clks, clks);
930 if (ret)
931 return ret;
932 ret = clk_bulk_enable(num_clks, clks);
933 if (ret)
934 clk_bulk_unprepare(num_clks, clks);
935
936 return ret;
937 }
938
939 static inline void clk_bulk_disable_unprepare(int num_clks,
940 const struct clk_bulk_data *clks)
941 {
942 clk_bulk_disable(num_clks, clks);
943 clk_bulk_unprepare(num_clks, clks);
944 }
945
946 /**
947 * clk_get_optional - lookup and obtain a reference to an optional clock
948 * producer.
949 * @dev: device for clock "consumer"
950 * @id: clock consumer ID
951 *
952 * Behaves the same as clk_get() except where there is no clock producer. In
953 * this case, instead of returning -ENOENT, the function returns NULL.
954 */
955 static inline struct clk *clk_get_optional(struct device *dev, const char *id)
956 {
957 struct clk *clk = clk_get(dev, id);
958
959 if (clk == ERR_PTR(-ENOENT))
960 return NULL;
961
962 return clk;
963 }
964
965 #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
966 struct clk *of_clk_get(struct device_node *np, int index);
967 struct clk *of_clk_get_by_name(struct device_node *np, const char *name);
968 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec);
969 #else
970 static inline struct clk *of_clk_get(struct device_node *np, int index)
971 {
972 return ERR_PTR(-ENOENT);
973 }
974 static inline struct clk *of_clk_get_by_name(struct device_node *np,
975 const char *name)
976 {
977 return ERR_PTR(-ENOENT);
978 }
979 static inline struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
980 {
981 return ERR_PTR(-ENOENT);
982 }
983 #endif
984
985 #endif