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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 : 3 : static inline int clk_prepare_enable(struct clk *clk)
904 : : {
905 : : int ret;
906 : :
907 : 3 : ret = clk_prepare(clk);
908 : 3 : if (ret)
909 : : return ret;
910 : 3 : ret = clk_enable(clk);
911 : 3 : if (ret)
912 : 0 : clk_unprepare(clk);
913 : :
914 : 3 : 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 : 3 : clk_disable(clk);
921 : 3 : 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
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