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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 
clk_notifier_register(struct clk * clk,struct notifier_block * nb)177 static inline int clk_notifier_register(struct clk *clk,
178 					struct notifier_block *nb)
179 {
180 	return -ENOTSUPP;
181 }
182 
clk_notifier_unregister(struct clk * clk,struct notifier_block * nb)183 static inline int clk_notifier_unregister(struct clk *clk,
184 					  struct notifier_block *nb)
185 {
186 	return -ENOTSUPP;
187 }
188 
clk_get_accuracy(struct clk * clk)189 static inline long clk_get_accuracy(struct clk *clk)
190 {
191 	return -ENOTSUPP;
192 }
193 
clk_set_phase(struct clk * clk,int phase)194 static inline long clk_set_phase(struct clk *clk, int phase)
195 {
196 	return -ENOTSUPP;
197 }
198 
clk_get_phase(struct clk * clk)199 static inline long clk_get_phase(struct clk *clk)
200 {
201 	return -ENOTSUPP;
202 }
203 
clk_set_duty_cycle(struct clk * clk,unsigned int num,unsigned int den)204 static inline int clk_set_duty_cycle(struct clk *clk, unsigned int num,
205 				     unsigned int den)
206 {
207 	return -ENOTSUPP;
208 }
209 
clk_get_scaled_duty_cycle(struct clk * clk,unsigned int scale)210 static inline unsigned int clk_get_scaled_duty_cycle(struct clk *clk,
211 						     unsigned int scale)
212 {
213 	return 0;
214 }
215 
clk_is_match(const struct clk * p,const struct clk * q)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
clk_prepare(struct clk * clk)236 static inline int clk_prepare(struct clk *clk)
237 {
238 	might_sleep();
239 	return 0;
240 }
241 
242 static inline int __must_check
clk_bulk_prepare(int num_clks,const struct clk_bulk_data * clks)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
clk_unprepare(struct clk * clk)263 static inline void clk_unprepare(struct clk *clk)
264 {
265 	might_sleep();
266 }
clk_bulk_unprepare(int num_clks,const struct clk_bulk_data * clks)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  * Updating the rate starts at the top-most affected clock and then
631  * walks the tree down to the bottom-most clock that needs updating.
632  *
633  * Returns success (0) or negative errno.
634  */
635 int clk_set_rate(struct clk *clk, unsigned long rate);
636 
637 /**
638  * clk_set_rate_exclusive- set the clock rate and claim exclusivity over
639  *                         clock source
640  * @clk: clock source
641  * @rate: desired clock rate in Hz
642  *
643  * This helper function allows drivers to atomically set the rate of a producer
644  * and claim exclusivity over the rate control of the producer.
645  *
646  * It is essentially a combination of clk_set_rate() and
647  * clk_rate_exclusite_get(). Caller must balance this call with a call to
648  * clk_rate_exclusive_put()
649  *
650  * Returns success (0) or negative errno.
651  */
652 int clk_set_rate_exclusive(struct clk *clk, unsigned long rate);
653 
654 /**
655  * clk_has_parent - check if a clock is a possible parent for another
656  * @clk: clock source
657  * @parent: parent clock source
658  *
659  * This function can be used in drivers that need to check that a clock can be
660  * the parent of another without actually changing the parent.
661  *
662  * Returns true if @parent is a possible parent for @clk, false otherwise.
663  */
664 bool clk_has_parent(struct clk *clk, struct clk *parent);
665 
666 /**
667  * clk_set_rate_range - set a rate range for a clock source
668  * @clk: clock source
669  * @min: desired minimum clock rate in Hz, inclusive
670  * @max: desired maximum clock rate in Hz, inclusive
671  *
672  * Returns success (0) or negative errno.
673  */
674 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max);
675 
676 /**
677  * clk_set_min_rate - set a minimum clock rate for a clock source
678  * @clk: clock source
679  * @rate: desired minimum clock rate in Hz, inclusive
680  *
681  * Returns success (0) or negative errno.
682  */
683 int clk_set_min_rate(struct clk *clk, unsigned long rate);
684 
685 /**
686  * clk_set_max_rate - set a maximum clock rate for a clock source
687  * @clk: clock source
688  * @rate: desired maximum clock rate in Hz, inclusive
689  *
690  * Returns success (0) or negative errno.
691  */
692 int clk_set_max_rate(struct clk *clk, unsigned long rate);
693 
694 /**
695  * clk_set_parent - set the parent clock source for this clock
696  * @clk: clock source
697  * @parent: parent clock source
698  *
699  * Returns success (0) or negative errno.
700  */
701 int clk_set_parent(struct clk *clk, struct clk *parent);
702 
703 /**
704  * clk_get_parent - get the parent clock source for this clock
705  * @clk: clock source
706  *
707  * Returns struct clk corresponding to parent clock source, or
708  * valid IS_ERR() condition containing errno.
709  */
710 struct clk *clk_get_parent(struct clk *clk);
711 
712 /**
713  * clk_get_sys - get a clock based upon the device name
714  * @dev_id: device name
715  * @con_id: connection ID
716  *
717  * Returns a struct clk corresponding to the clock producer, or
718  * valid IS_ERR() condition containing errno.  The implementation
719  * uses @dev_id and @con_id to determine the clock consumer, and
720  * thereby the clock producer. In contrast to clk_get() this function
721  * takes the device name instead of the device itself for identification.
722  *
723  * Drivers must assume that the clock source is not enabled.
724  *
725  * clk_get_sys should not be called from within interrupt context.
726  */
727 struct clk *clk_get_sys(const char *dev_id, const char *con_id);
728 
729 /**
730  * clk_save_context - save clock context for poweroff
731  *
732  * Saves the context of the clock register for powerstates in which the
733  * contents of the registers will be lost. Occurs deep within the suspend
734  * code so locking is not necessary.
735  */
736 int clk_save_context(void);
737 
738 /**
739  * clk_restore_context - restore clock context after poweroff
740  *
741  * This occurs with all clocks enabled. Occurs deep within the resume code
742  * so locking is not necessary.
743  */
744 void clk_restore_context(void);
745 
746 #else /* !CONFIG_HAVE_CLK */
747 
clk_get(struct device * dev,const char * id)748 static inline struct clk *clk_get(struct device *dev, const char *id)
749 {
750 	return NULL;
751 }
752 
clk_bulk_get(struct device * dev,int num_clks,struct clk_bulk_data * clks)753 static inline int __must_check clk_bulk_get(struct device *dev, int num_clks,
754 					    struct clk_bulk_data *clks)
755 {
756 	return 0;
757 }
758 
clk_bulk_get_optional(struct device * dev,int num_clks,struct clk_bulk_data * clks)759 static inline int __must_check clk_bulk_get_optional(struct device *dev,
760 				int num_clks, struct clk_bulk_data *clks)
761 {
762 	return 0;
763 }
764 
clk_bulk_get_all(struct device * dev,struct clk_bulk_data ** clks)765 static inline int __must_check clk_bulk_get_all(struct device *dev,
766 					 struct clk_bulk_data **clks)
767 {
768 	return 0;
769 }
770 
devm_clk_get(struct device * dev,const char * id)771 static inline struct clk *devm_clk_get(struct device *dev, const char *id)
772 {
773 	return NULL;
774 }
775 
devm_clk_get_optional(struct device * dev,const char * id)776 static inline struct clk *devm_clk_get_optional(struct device *dev,
777 						const char *id)
778 {
779 	return NULL;
780 }
781 
devm_clk_bulk_get(struct device * dev,int num_clks,struct clk_bulk_data * clks)782 static inline int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
783 						 struct clk_bulk_data *clks)
784 {
785 	return 0;
786 }
787 
devm_clk_bulk_get_optional(struct device * dev,int num_clks,struct clk_bulk_data * clks)788 static inline int __must_check devm_clk_bulk_get_optional(struct device *dev,
789 				int num_clks, struct clk_bulk_data *clks)
790 {
791 	return 0;
792 }
793 
devm_clk_bulk_get_all(struct device * dev,struct clk_bulk_data ** clks)794 static inline int __must_check devm_clk_bulk_get_all(struct device *dev,
795 						     struct clk_bulk_data **clks)
796 {
797 
798 	return 0;
799 }
800 
devm_get_clk_from_child(struct device * dev,struct device_node * np,const char * con_id)801 static inline struct clk *devm_get_clk_from_child(struct device *dev,
802 				struct device_node *np, const char *con_id)
803 {
804 	return NULL;
805 }
806 
clk_put(struct clk * clk)807 static inline void clk_put(struct clk *clk) {}
808 
clk_bulk_put(int num_clks,struct clk_bulk_data * clks)809 static inline void clk_bulk_put(int num_clks, struct clk_bulk_data *clks) {}
810 
clk_bulk_put_all(int num_clks,struct clk_bulk_data * clks)811 static inline void clk_bulk_put_all(int num_clks, struct clk_bulk_data *clks) {}
812 
devm_clk_put(struct device * dev,struct clk * clk)813 static inline void devm_clk_put(struct device *dev, struct clk *clk) {}
814 
815 
clk_rate_exclusive_get(struct clk * clk)816 static inline int clk_rate_exclusive_get(struct clk *clk)
817 {
818 	return 0;
819 }
820 
clk_rate_exclusive_put(struct clk * clk)821 static inline void clk_rate_exclusive_put(struct clk *clk) {}
822 
clk_enable(struct clk * clk)823 static inline int clk_enable(struct clk *clk)
824 {
825 	return 0;
826 }
827 
clk_bulk_enable(int num_clks,const struct clk_bulk_data * clks)828 static inline int __must_check clk_bulk_enable(int num_clks,
829 					       const struct clk_bulk_data *clks)
830 {
831 	return 0;
832 }
833 
clk_disable(struct clk * clk)834 static inline void clk_disable(struct clk *clk) {}
835 
836 
clk_bulk_disable(int num_clks,const struct clk_bulk_data * clks)837 static inline void clk_bulk_disable(int num_clks,
838 				    const struct clk_bulk_data *clks) {}
839 
clk_get_rate(struct clk * clk)840 static inline unsigned long clk_get_rate(struct clk *clk)
841 {
842 	return 0;
843 }
844 
clk_set_rate(struct clk * clk,unsigned long rate)845 static inline int clk_set_rate(struct clk *clk, unsigned long rate)
846 {
847 	return 0;
848 }
849 
clk_set_rate_exclusive(struct clk * clk,unsigned long rate)850 static inline int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
851 {
852 	return 0;
853 }
854 
clk_round_rate(struct clk * clk,unsigned long rate)855 static inline long clk_round_rate(struct clk *clk, unsigned long rate)
856 {
857 	return 0;
858 }
859 
clk_has_parent(struct clk * clk,struct clk * parent)860 static inline bool clk_has_parent(struct clk *clk, struct clk *parent)
861 {
862 	return true;
863 }
864 
clk_set_rate_range(struct clk * clk,unsigned long min,unsigned long max)865 static inline int clk_set_rate_range(struct clk *clk, unsigned long min,
866 				     unsigned long max)
867 {
868 	return 0;
869 }
870 
clk_set_min_rate(struct clk * clk,unsigned long rate)871 static inline int clk_set_min_rate(struct clk *clk, unsigned long rate)
872 {
873 	return 0;
874 }
875 
clk_set_max_rate(struct clk * clk,unsigned long rate)876 static inline int clk_set_max_rate(struct clk *clk, unsigned long rate)
877 {
878 	return 0;
879 }
880 
clk_set_parent(struct clk * clk,struct clk * parent)881 static inline int clk_set_parent(struct clk *clk, struct clk *parent)
882 {
883 	return 0;
884 }
885 
clk_get_parent(struct clk * clk)886 static inline struct clk *clk_get_parent(struct clk *clk)
887 {
888 	return NULL;
889 }
890 
clk_get_sys(const char * dev_id,const char * con_id)891 static inline struct clk *clk_get_sys(const char *dev_id, const char *con_id)
892 {
893 	return NULL;
894 }
895 
clk_save_context(void)896 static inline int clk_save_context(void)
897 {
898 	return 0;
899 }
900 
clk_restore_context(void)901 static inline void clk_restore_context(void) {}
902 
903 #endif
904 
905 /* clk_prepare_enable helps cases using clk_enable in non-atomic context. */
clk_prepare_enable(struct clk * clk)906 static inline int clk_prepare_enable(struct clk *clk)
907 {
908 	int ret;
909 
910 	ret = clk_prepare(clk);
911 	if (ret)
912 		return ret;
913 	ret = clk_enable(clk);
914 	if (ret)
915 		clk_unprepare(clk);
916 
917 	return ret;
918 }
919 
920 /* clk_disable_unprepare helps cases using clk_disable in non-atomic context. */
clk_disable_unprepare(struct clk * clk)921 static inline void clk_disable_unprepare(struct clk *clk)
922 {
923 	clk_disable(clk);
924 	clk_unprepare(clk);
925 }
926 
927 static inline int __must_check
clk_bulk_prepare_enable(int num_clks,const struct clk_bulk_data * clks)928 clk_bulk_prepare_enable(int num_clks, const struct clk_bulk_data *clks)
929 {
930 	int ret;
931 
932 	ret = clk_bulk_prepare(num_clks, clks);
933 	if (ret)
934 		return ret;
935 	ret = clk_bulk_enable(num_clks, clks);
936 	if (ret)
937 		clk_bulk_unprepare(num_clks, clks);
938 
939 	return ret;
940 }
941 
clk_bulk_disable_unprepare(int num_clks,const struct clk_bulk_data * clks)942 static inline void clk_bulk_disable_unprepare(int num_clks,
943 					      const struct clk_bulk_data *clks)
944 {
945 	clk_bulk_disable(num_clks, clks);
946 	clk_bulk_unprepare(num_clks, clks);
947 }
948 
949 /**
950  * clk_get_optional - lookup and obtain a reference to an optional clock
951  *		      producer.
952  * @dev: device for clock "consumer"
953  * @id: clock consumer ID
954  *
955  * Behaves the same as clk_get() except where there is no clock producer. In
956  * this case, instead of returning -ENOENT, the function returns NULL.
957  */
clk_get_optional(struct device * dev,const char * id)958 static inline struct clk *clk_get_optional(struct device *dev, const char *id)
959 {
960 	struct clk *clk = clk_get(dev, id);
961 
962 	if (clk == ERR_PTR(-ENOENT))
963 		return NULL;
964 
965 	return clk;
966 }
967 
968 #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
969 struct clk *of_clk_get(struct device_node *np, int index);
970 struct clk *of_clk_get_by_name(struct device_node *np, const char *name);
971 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec);
972 #else
of_clk_get(struct device_node * np,int index)973 static inline struct clk *of_clk_get(struct device_node *np, int index)
974 {
975 	return ERR_PTR(-ENOENT);
976 }
of_clk_get_by_name(struct device_node * np,const char * name)977 static inline struct clk *of_clk_get_by_name(struct device_node *np,
978 					     const char *name)
979 {
980 	return ERR_PTR(-ENOENT);
981 }
of_clk_get_from_provider(struct of_phandle_args * clkspec)982 static inline struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
983 {
984 	return ERR_PTR(-ENOENT);
985 }
986 #endif
987 
988 #endif
989