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