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TOMOYO Linux Cross Reference
Linux/include/linux/clk.h

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  1 /*
  2  *  linux/include/linux/clk.h
  3  *
  4  *  Copyright (C) 2004 ARM Limited.
  5  *  Written by Deep Blue Solutions Limited.
  6  *  Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
  7  *
  8  * This program is free software; you can redistribute it and/or modify
  9  * it under the terms of the GNU General Public License version 2 as
 10  * published by the Free Software Foundation.
 11  */
 12 #ifndef __LINUX_CLK_H
 13 #define __LINUX_CLK_H
 14 
 15 #include <linux/err.h>
 16 #include <linux/kernel.h>
 17 #include <linux/notifier.h>
 18 
 19 struct device;
 20 struct clk;
 21 struct device_node;
 22 struct of_phandle_args;
 23 
 24 /**
 25  * DOC: clk notifier callback types
 26  *
 27  * PRE_RATE_CHANGE - called immediately before the clk rate is changed,
 28  *     to indicate that the rate change will proceed.  Drivers must
 29  *     immediately terminate any operations that will be affected by the
 30  *     rate change.  Callbacks may either return NOTIFY_DONE, NOTIFY_OK,
 31  *     NOTIFY_STOP or NOTIFY_BAD.
 32  *
 33  * ABORT_RATE_CHANGE: called if the rate change failed for some reason
 34  *     after PRE_RATE_CHANGE.  In this case, all registered notifiers on
 35  *     the clk will be called with ABORT_RATE_CHANGE. Callbacks must
 36  *     always return NOTIFY_DONE or NOTIFY_OK.
 37  *
 38  * POST_RATE_CHANGE - called after the clk rate change has successfully
 39  *     completed.  Callbacks must always return NOTIFY_DONE or NOTIFY_OK.
 40  *
 41  */
 42 #define PRE_RATE_CHANGE                 BIT(0)
 43 #define POST_RATE_CHANGE                BIT(1)
 44 #define ABORT_RATE_CHANGE               BIT(2)
 45 
 46 /**
 47  * struct clk_notifier - associate a clk with a notifier
 48  * @clk: struct clk * to associate the notifier with
 49  * @notifier_head: a blocking_notifier_head for this clk
 50  * @node: linked list pointers
 51  *
 52  * A list of struct clk_notifier is maintained by the notifier code.
 53  * An entry is created whenever code registers the first notifier on a
 54  * particular @clk.  Future notifiers on that @clk are added to the
 55  * @notifier_head.
 56  */
 57 struct clk_notifier {
 58         struct clk                      *clk;
 59         struct srcu_notifier_head       notifier_head;
 60         struct list_head                node;
 61 };
 62 
 63 /**
 64  * struct clk_notifier_data - rate data to pass to the notifier callback
 65  * @clk: struct clk * being changed
 66  * @old_rate: previous rate of this clk
 67  * @new_rate: new rate of this clk
 68  *
 69  * For a pre-notifier, old_rate is the clk's rate before this rate
 70  * change, and new_rate is what the rate will be in the future.  For a
 71  * post-notifier, old_rate and new_rate are both set to the clk's
 72  * current rate (this was done to optimize the implementation).
 73  */
 74 struct clk_notifier_data {
 75         struct clk              *clk;
 76         unsigned long           old_rate;
 77         unsigned long           new_rate;
 78 };
 79 
 80 /**
 81  * struct clk_bulk_data - Data used for bulk clk operations.
 82  *
 83  * @id: clock consumer ID
 84  * @clk: struct clk * to store the associated clock
 85  *
 86  * The CLK APIs provide a series of clk_bulk_() API calls as
 87  * a convenience to consumers which require multiple clks.  This
 88  * structure is used to manage data for these calls.
 89  */
 90 struct clk_bulk_data {
 91         const char              *id;
 92         struct clk              *clk;
 93 };
 94 
 95 #ifdef CONFIG_COMMON_CLK
 96 
 97 /**
 98  * clk_notifier_register: register a clock rate-change notifier callback
 99  * @clk: clock whose rate we are interested in
100  * @nb: notifier block with callback function pointer
101  *
102  * ProTip: debugging across notifier chains can be frustrating. Make sure that
103  * your notifier callback function prints a nice big warning in case of
104  * failure.
105  */
106 int clk_notifier_register(struct clk *clk, struct notifier_block *nb);
107 
108 /**
109  * clk_notifier_unregister: unregister a clock rate-change notifier callback
110  * @clk: clock whose rate we are no longer interested in
111  * @nb: notifier block which will be unregistered
112  */
113 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb);
114 
115 /**
116  * clk_get_accuracy - obtain the clock accuracy in ppb (parts per billion)
117  *                    for a clock source.
118  * @clk: clock source
119  *
120  * This gets the clock source accuracy expressed in ppb.
121  * A perfect clock returns 0.
122  */
123 long clk_get_accuracy(struct clk *clk);
124 
125 /**
126  * clk_set_phase - adjust the phase shift of a clock signal
127  * @clk: clock signal source
128  * @degrees: number of degrees the signal is shifted
129  *
130  * Shifts the phase of a clock signal by the specified degrees. Returns 0 on
131  * success, -EERROR otherwise.
132  */
133 int clk_set_phase(struct clk *clk, int degrees);
134 
135 /**
136  * clk_get_phase - return the phase shift of a clock signal
137  * @clk: clock signal source
138  *
139  * Returns the phase shift of a clock node in degrees, otherwise returns
140  * -EERROR.
141  */
142 int clk_get_phase(struct clk *clk);
143 
144 /**
145  * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
146  * @clk: clock signal source
147  * @num: numerator of the duty cycle ratio to be applied
148  * @den: denominator of the duty cycle ratio to be applied
149  *
150  * Adjust the duty cycle of a clock signal by the specified ratio. Returns 0 on
151  * success, -EERROR otherwise.
152  */
153 int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den);
154 
155 /**
156  * clk_get_duty_cycle - return the duty cycle ratio of a clock signal
157  * @clk: clock signal source
158  * @scale: scaling factor to be applied to represent the ratio as an integer
159  *
160  * Returns the duty cycle ratio multiplied by the scale provided, otherwise
161  * returns -EERROR.
162  */
163 int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale);
164 
165 /**
166  * clk_is_match - check if two clk's point to the same hardware clock
167  * @p: clk compared against q
168  * @q: clk compared against p
169  *
170  * Returns true if the two struct clk pointers both point to the same hardware
171  * clock node. Put differently, returns true if @p and @q
172  * share the same &struct clk_core object.
173  *
174  * Returns false otherwise. Note that two NULL clks are treated as matching.
175  */
176 bool clk_is_match(const struct clk *p, const struct clk *q);
177 
178 #else
179 
180 static inline int clk_notifier_register(struct clk *clk,
181                                         struct notifier_block *nb)
182 {
183         return -ENOTSUPP;
184 }
185 
186 static inline int clk_notifier_unregister(struct clk *clk,
187                                           struct notifier_block *nb)
188 {
189         return -ENOTSUPP;
190 }
191 
192 static inline long clk_get_accuracy(struct clk *clk)
193 {
194         return -ENOTSUPP;
195 }
196 
197 static inline long clk_set_phase(struct clk *clk, int phase)
198 {
199         return -ENOTSUPP;
200 }
201 
202 static inline long clk_get_phase(struct clk *clk)
203 {
204         return -ENOTSUPP;
205 }
206 
207 static inline int clk_set_duty_cycle(struct clk *clk, unsigned int num,
208                                      unsigned int den)
209 {
210         return -ENOTSUPP;
211 }
212 
213 static inline unsigned int clk_get_scaled_duty_cycle(struct clk *clk,
214                                                      unsigned int scale)
215 {
216         return 0;
217 }
218 
219 static inline bool clk_is_match(const struct clk *p, const struct clk *q)
220 {
221         return p == q;
222 }
223 
224 #endif
225 
226 /**
227  * clk_prepare - prepare a clock source
228  * @clk: clock source
229  *
230  * This prepares the clock source for use.
231  *
232  * Must not be called from within atomic context.
233  */
234 #ifdef CONFIG_HAVE_CLK_PREPARE
235 int clk_prepare(struct clk *clk);
236 int __must_check clk_bulk_prepare(int num_clks,
237                                   const struct clk_bulk_data *clks);
238 #else
239 static inline int clk_prepare(struct clk *clk)
240 {
241         might_sleep();
242         return 0;
243 }
244 
245 static inline int __must_check clk_bulk_prepare(int num_clks, struct clk_bulk_data *clks)
246 {
247         might_sleep();
248         return 0;
249 }
250 #endif
251 
252 /**
253  * clk_unprepare - undo preparation of a clock source
254  * @clk: clock source
255  *
256  * This undoes a previously prepared clock.  The caller must balance
257  * the number of prepare and unprepare calls.
258  *
259  * Must not be called from within atomic context.
260  */
261 #ifdef CONFIG_HAVE_CLK_PREPARE
262 void clk_unprepare(struct clk *clk);
263 void clk_bulk_unprepare(int num_clks, const struct clk_bulk_data *clks);
264 #else
265 static inline void clk_unprepare(struct clk *clk)
266 {
267         might_sleep();
268 }
269 static inline void clk_bulk_unprepare(int num_clks, struct clk_bulk_data *clks)
270 {
271         might_sleep();
272 }
273 #endif
274 
275 #ifdef CONFIG_HAVE_CLK
276 /**
277  * clk_get - lookup and obtain a reference to a clock producer.
278  * @dev: device for clock "consumer"
279  * @id: clock consumer ID
280  *
281  * Returns a struct clk corresponding to the clock producer, or
282  * valid IS_ERR() condition containing errno.  The implementation
283  * uses @dev and @id to determine the clock consumer, and thereby
284  * the clock producer.  (IOW, @id may be identical strings, but
285  * clk_get may return different clock producers depending on @dev.)
286  *
287  * Drivers must assume that the clock source is not enabled.
288  *
289  * clk_get should not be called from within interrupt context.
290  */
291 struct clk *clk_get(struct device *dev, const char *id);
292 
293 /**
294  * clk_bulk_get - lookup and obtain a number of references to clock producer.
295  * @dev: device for clock "consumer"
296  * @num_clks: the number of clk_bulk_data
297  * @clks: the clk_bulk_data table of consumer
298  *
299  * This helper function allows drivers to get several clk consumers in one
300  * operation. If any of the clk cannot be acquired then any clks
301  * that were obtained will be freed before returning to the caller.
302  *
303  * Returns 0 if all clocks specified in clk_bulk_data table are obtained
304  * successfully, or valid IS_ERR() condition containing errno.
305  * The implementation uses @dev and @clk_bulk_data.id to determine the
306  * clock consumer, and thereby the clock producer.
307  * The clock returned is stored in each @clk_bulk_data.clk field.
308  *
309  * Drivers must assume that the clock source is not enabled.
310  *
311  * clk_bulk_get should not be called from within interrupt context.
312  */
313 int __must_check clk_bulk_get(struct device *dev, int num_clks,
314                               struct clk_bulk_data *clks);
315 /**
316  * clk_bulk_get_all - lookup and obtain all available references to clock
317  *                    producer.
318  * @dev: device for clock "consumer"
319  * @clks: pointer to the clk_bulk_data table of consumer
320  *
321  * This helper function allows drivers to get all clk consumers in one
322  * operation. If any of the clk cannot be acquired then any clks
323  * that were obtained will be freed before returning to the caller.
324  *
325  * Returns a positive value for the number of clocks obtained while the
326  * clock references are stored in the clk_bulk_data table in @clks field.
327  * Returns 0 if there're none and a negative value if something failed.
328  *
329  * Drivers must assume that the clock source is not enabled.
330  *
331  * clk_bulk_get should not be called from within interrupt context.
332  */
333 int __must_check clk_bulk_get_all(struct device *dev,
334                                   struct clk_bulk_data **clks);
335 /**
336  * devm_clk_bulk_get - managed get multiple clk consumers
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  * Return 0 on success, an errno on failure.
342  *
343  * This helper function allows drivers to get several clk
344  * consumers in one operation with management, the clks will
345  * automatically be freed when the device is unbound.
346  */
347 int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
348                                    struct clk_bulk_data *clks);
349 /**
350  * devm_clk_bulk_get_all - managed get multiple clk consumers
351  * @dev: device for clock "consumer"
352  * @clks: pointer to the clk_bulk_data table of consumer
353  *
354  * Returns a positive value for the number of clocks obtained while the
355  * clock references are stored in the clk_bulk_data table in @clks field.
356  * Returns 0 if there're none and a negative value if something failed.
357  *
358  * This helper function allows drivers to get several clk
359  * consumers in one operation with management, the clks will
360  * automatically be freed when the device is unbound.
361  */
362 
363 int __must_check devm_clk_bulk_get_all(struct device *dev,
364                                        struct clk_bulk_data **clks);
365 
366 /**
367  * devm_clk_get - lookup and obtain a managed reference to a clock producer.
368  * @dev: device for clock "consumer"
369  * @id: clock consumer ID
370  *
371  * Returns a struct clk corresponding to the clock producer, or
372  * valid IS_ERR() condition containing errno.  The implementation
373  * uses @dev and @id to determine the clock consumer, and thereby
374  * the clock producer.  (IOW, @id may be identical strings, but
375  * clk_get may return different clock producers depending on @dev.)
376  *
377  * Drivers must assume that the clock source is not enabled.
378  *
379  * devm_clk_get should not be called from within interrupt context.
380  *
381  * The clock will automatically be freed when the device is unbound
382  * from the bus.
383  */
384 struct clk *devm_clk_get(struct device *dev, const char *id);
385 
386 /**
387  * devm_clk_get_optional - lookup and obtain a managed reference to an optional
388  *                         clock producer.
389  * @dev: device for clock "consumer"
390  * @id: clock consumer ID
391  *
392  * Behaves the same as devm_clk_get() except where there is no clock producer.
393  * In this case, instead of returning -ENOENT, the function returns NULL.
394  */
395 struct clk *devm_clk_get_optional(struct device *dev, const char *id);
396 
397 /**
398  * devm_get_clk_from_child - lookup and obtain a managed reference to a
399  *                           clock producer from child node.
400  * @dev: device for clock "consumer"
401  * @np: pointer to clock consumer node
402  * @con_id: clock consumer ID
403  *
404  * This function parses the clocks, and uses them to look up the
405  * struct clk from the registered list of clock providers by using
406  * @np and @con_id
407  *
408  * The clock will automatically be freed when the device is unbound
409  * from the bus.
410  */
411 struct clk *devm_get_clk_from_child(struct device *dev,
412                                     struct device_node *np, const char *con_id);
413 /**
414  * clk_rate_exclusive_get - get exclusivity over the rate control of a
415  *                          producer
416  * @clk: clock source
417  *
418  * This function allows drivers to get exclusive control over the rate of a
419  * provider. It prevents any other consumer to execute, even indirectly,
420  * opereation which could alter the rate of the provider or cause glitches
421  *
422  * If exlusivity is claimed more than once on clock, even by the same driver,
423  * the rate effectively gets locked as exclusivity can't be preempted.
424  *
425  * Must not be called from within atomic context.
426  *
427  * Returns success (0) or negative errno.
428  */
429 int clk_rate_exclusive_get(struct clk *clk);
430 
431 /**
432  * clk_rate_exclusive_put - release exclusivity over the rate control of a
433  *                          producer
434  * @clk: clock source
435  *
436  * This function allows drivers to release the exclusivity it previously got
437  * from clk_rate_exclusive_get()
438  *
439  * The caller must balance the number of clk_rate_exclusive_get() and
440  * clk_rate_exclusive_put() calls.
441  *
442  * Must not be called from within atomic context.
443  */
444 void clk_rate_exclusive_put(struct clk *clk);
445 
446 /**
447  * clk_enable - inform the system when the clock source should be running.
448  * @clk: clock source
449  *
450  * If the clock can not be enabled/disabled, this should return success.
451  *
452  * May be called from atomic contexts.
453  *
454  * Returns success (0) or negative errno.
455  */
456 int clk_enable(struct clk *clk);
457 
458 /**
459  * clk_bulk_enable - inform the system when the set of clks should be running.
460  * @num_clks: the number of clk_bulk_data
461  * @clks: the clk_bulk_data table of consumer
462  *
463  * May be called from atomic contexts.
464  *
465  * Returns success (0) or negative errno.
466  */
467 int __must_check clk_bulk_enable(int num_clks,
468                                  const struct clk_bulk_data *clks);
469 
470 /**
471  * clk_disable - inform the system when the clock source is no longer required.
472  * @clk: clock source
473  *
474  * Inform the system that a clock source is no longer required by
475  * a driver and may be shut down.
476  *
477  * May be called from atomic contexts.
478  *
479  * Implementation detail: if the clock source is shared between
480  * multiple drivers, clk_enable() calls must be balanced by the
481  * same number of clk_disable() calls for the clock source to be
482  * disabled.
483  */
484 void clk_disable(struct clk *clk);
485 
486 /**
487  * clk_bulk_disable - inform the system when the set of clks is no
488  *                    longer required.
489  * @num_clks: the number of clk_bulk_data
490  * @clks: the clk_bulk_data table of consumer
491  *
492  * Inform the system that a set of clks is no longer required by
493  * a driver and may be shut down.
494  *
495  * May be called from atomic contexts.
496  *
497  * Implementation detail: if the set of clks is shared between
498  * multiple drivers, clk_bulk_enable() calls must be balanced by the
499  * same number of clk_bulk_disable() calls for the clock source to be
500  * disabled.
501  */
502 void clk_bulk_disable(int num_clks, const struct clk_bulk_data *clks);
503 
504 /**
505  * clk_get_rate - obtain the current clock rate (in Hz) for a clock source.
506  *                This is only valid once the clock source has been enabled.
507  * @clk: clock source
508  */
509 unsigned long clk_get_rate(struct clk *clk);
510 
511 /**
512  * clk_put      - "free" the clock source
513  * @clk: clock source
514  *
515  * Note: drivers must ensure that all clk_enable calls made on this
516  * clock source are balanced by clk_disable calls prior to calling
517  * this function.
518  *
519  * clk_put should not be called from within interrupt context.
520  */
521 void clk_put(struct clk *clk);
522 
523 /**
524  * clk_bulk_put - "free" the clock source
525  * @num_clks: the number of clk_bulk_data
526  * @clks: the clk_bulk_data table of consumer
527  *
528  * Note: drivers must ensure that all clk_bulk_enable calls made on this
529  * clock source are balanced by clk_bulk_disable calls prior to calling
530  * this function.
531  *
532  * clk_bulk_put should not be called from within interrupt context.
533  */
534 void clk_bulk_put(int num_clks, struct clk_bulk_data *clks);
535 
536 /**
537  * clk_bulk_put_all - "free" all the clock source
538  * @num_clks: the number of clk_bulk_data
539  * @clks: the clk_bulk_data table of consumer
540  *
541  * Note: drivers must ensure that all clk_bulk_enable calls made on this
542  * clock source are balanced by clk_bulk_disable calls prior to calling
543  * this function.
544  *
545  * clk_bulk_put_all should not be called from within interrupt context.
546  */
547 void clk_bulk_put_all(int num_clks, struct clk_bulk_data *clks);
548 
549 /**
550  * devm_clk_put - "free" a managed clock source
551  * @dev: device used to acquire the clock
552  * @clk: clock source acquired with devm_clk_get()
553  *
554  * Note: drivers must ensure that all clk_enable calls made on this
555  * clock source are balanced by clk_disable calls prior to calling
556  * this function.
557  *
558  * clk_put should not be called from within interrupt context.
559  */
560 void devm_clk_put(struct device *dev, struct clk *clk);
561 
562 /*
563  * The remaining APIs are optional for machine class support.
564  */
565 
566 
567 /**
568  * clk_round_rate - adjust a rate to the exact rate a clock can provide
569  * @clk: clock source
570  * @rate: desired clock rate in Hz
571  *
572  * This answers the question "if I were to pass @rate to clk_set_rate(),
573  * what clock rate would I end up with?" without changing the hardware
574  * in any way.  In other words:
575  *
576  *   rate = clk_round_rate(clk, r);
577  *
578  * and:
579  *
580  *   clk_set_rate(clk, r);
581  *   rate = clk_get_rate(clk);
582  *
583  * are equivalent except the former does not modify the clock hardware
584  * in any way.
585  *
586  * Returns rounded clock rate in Hz, or negative errno.
587  */
588 long clk_round_rate(struct clk *clk, unsigned long rate);
589 
590 /**
591  * clk_set_rate - set the clock rate for a clock source
592  * @clk: clock source
593  * @rate: desired clock rate in Hz
594  *
595  * Returns success (0) or negative errno.
596  */
597 int clk_set_rate(struct clk *clk, unsigned long rate);
598 
599 /**
600  * clk_set_rate_exclusive- set the clock rate and claim exclusivity over
601  *                         clock source
602  * @clk: clock source
603  * @rate: desired clock rate in Hz
604  *
605  * This helper function allows drivers to atomically set the rate of a producer
606  * and claim exclusivity over the rate control of the producer.
607  *
608  * It is essentially a combination of clk_set_rate() and
609  * clk_rate_exclusite_get(). Caller must balance this call with a call to
610  * clk_rate_exclusive_put()
611  *
612  * Returns success (0) or negative errno.
613  */
614 int clk_set_rate_exclusive(struct clk *clk, unsigned long rate);
615 
616 /**
617  * clk_has_parent - check if a clock is a possible parent for another
618  * @clk: clock source
619  * @parent: parent clock source
620  *
621  * This function can be used in drivers that need to check that a clock can be
622  * the parent of another without actually changing the parent.
623  *
624  * Returns true if @parent is a possible parent for @clk, false otherwise.
625  */
626 bool clk_has_parent(struct clk *clk, struct clk *parent);
627 
628 /**
629  * clk_set_rate_range - set a rate range for a clock source
630  * @clk: clock source
631  * @min: desired minimum clock rate in Hz, inclusive
632  * @max: desired maximum clock rate in Hz, inclusive
633  *
634  * Returns success (0) or negative errno.
635  */
636 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max);
637 
638 /**
639  * clk_set_min_rate - set a minimum clock rate for a clock source
640  * @clk: clock source
641  * @rate: desired minimum clock rate in Hz, inclusive
642  *
643  * Returns success (0) or negative errno.
644  */
645 int clk_set_min_rate(struct clk *clk, unsigned long rate);
646 
647 /**
648  * clk_set_max_rate - set a maximum clock rate for a clock source
649  * @clk: clock source
650  * @rate: desired maximum clock rate in Hz, inclusive
651  *
652  * Returns success (0) or negative errno.
653  */
654 int clk_set_max_rate(struct clk *clk, unsigned long rate);
655 
656 /**
657  * clk_set_parent - set the parent clock source for this clock
658  * @clk: clock source
659  * @parent: parent clock source
660  *
661  * Returns success (0) or negative errno.
662  */
663 int clk_set_parent(struct clk *clk, struct clk *parent);
664 
665 /**
666  * clk_get_parent - get the parent clock source for this clock
667  * @clk: clock source
668  *
669  * Returns struct clk corresponding to parent clock source, or
670  * valid IS_ERR() condition containing errno.
671  */
672 struct clk *clk_get_parent(struct clk *clk);
673 
674 /**
675  * clk_get_sys - get a clock based upon the device name
676  * @dev_id: device name
677  * @con_id: connection ID
678  *
679  * Returns a struct clk corresponding to the clock producer, or
680  * valid IS_ERR() condition containing errno.  The implementation
681  * uses @dev_id and @con_id to determine the clock consumer, and
682  * thereby the clock producer. In contrast to clk_get() this function
683  * takes the device name instead of the device itself for identification.
684  *
685  * Drivers must assume that the clock source is not enabled.
686  *
687  * clk_get_sys should not be called from within interrupt context.
688  */
689 struct clk *clk_get_sys(const char *dev_id, const char *con_id);
690 
691 /**
692  * clk_save_context - save clock context for poweroff
693  *
694  * Saves the context of the clock register for powerstates in which the
695  * contents of the registers will be lost. Occurs deep within the suspend
696  * code so locking is not necessary.
697  */
698 int clk_save_context(void);
699 
700 /**
701  * clk_restore_context - restore clock context after poweroff
702  *
703  * This occurs with all clocks enabled. Occurs deep within the resume code
704  * so locking is not necessary.
705  */
706 void clk_restore_context(void);
707 
708 #else /* !CONFIG_HAVE_CLK */
709 
710 static inline struct clk *clk_get(struct device *dev, const char *id)
711 {
712         return NULL;
713 }
714 
715 static inline int __must_check clk_bulk_get(struct device *dev, int num_clks,
716                                             struct clk_bulk_data *clks)
717 {
718         return 0;
719 }
720 
721 static inline int __must_check clk_bulk_get_all(struct device *dev,
722                                          struct clk_bulk_data **clks)
723 {
724         return 0;
725 }
726 
727 static inline struct clk *devm_clk_get(struct device *dev, const char *id)
728 {
729         return NULL;
730 }
731 
732 static inline struct clk *devm_clk_get_optional(struct device *dev,
733                                                 const char *id)
734 {
735         return NULL;
736 }
737 
738 static inline int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
739                                                  struct clk_bulk_data *clks)
740 {
741         return 0;
742 }
743 
744 static inline int __must_check devm_clk_bulk_get_all(struct device *dev,
745                                                      struct clk_bulk_data **clks)
746 {
747 
748         return 0;
749 }
750 
751 static inline struct clk *devm_get_clk_from_child(struct device *dev,
752                                 struct device_node *np, const char *con_id)
753 {
754         return NULL;
755 }
756 
757 static inline void clk_put(struct clk *clk) {}
758 
759 static inline void clk_bulk_put(int num_clks, struct clk_bulk_data *clks) {}
760 
761 static inline void clk_bulk_put_all(int num_clks, struct clk_bulk_data *clks) {}
762 
763 static inline void devm_clk_put(struct device *dev, struct clk *clk) {}
764 
765 
766 static inline int clk_rate_exclusive_get(struct clk *clk)
767 {
768         return 0;
769 }
770 
771 static inline void clk_rate_exclusive_put(struct clk *clk) {}
772 
773 static inline int clk_enable(struct clk *clk)
774 {
775         return 0;
776 }
777 
778 static inline int __must_check clk_bulk_enable(int num_clks, struct clk_bulk_data *clks)
779 {
780         return 0;
781 }
782 
783 static inline void clk_disable(struct clk *clk) {}
784 
785 
786 static inline void clk_bulk_disable(int num_clks,
787                                     struct clk_bulk_data *clks) {}
788 
789 static inline unsigned long clk_get_rate(struct clk *clk)
790 {
791         return 0;
792 }
793 
794 static inline int clk_set_rate(struct clk *clk, unsigned long rate)
795 {
796         return 0;
797 }
798 
799 static inline int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
800 {
801         return 0;
802 }
803 
804 static inline long clk_round_rate(struct clk *clk, unsigned long rate)
805 {
806         return 0;
807 }
808 
809 static inline bool clk_has_parent(struct clk *clk, struct clk *parent)
810 {
811         return true;
812 }
813 
814 static inline int clk_set_rate_range(struct clk *clk, unsigned long min,
815                                      unsigned long max)
816 {
817         return 0;
818 }
819 
820 static inline int clk_set_min_rate(struct clk *clk, unsigned long rate)
821 {
822         return 0;
823 }
824 
825 static inline int clk_set_max_rate(struct clk *clk, unsigned long rate)
826 {
827         return 0;
828 }
829 
830 static inline int clk_set_parent(struct clk *clk, struct clk *parent)
831 {
832         return 0;
833 }
834 
835 static inline struct clk *clk_get_parent(struct clk *clk)
836 {
837         return NULL;
838 }
839 
840 static inline struct clk *clk_get_sys(const char *dev_id, const char *con_id)
841 {
842         return NULL;
843 }
844 
845 static inline int clk_save_context(void)
846 {
847         return 0;
848 }
849 
850 static inline void clk_restore_context(void) {}
851 
852 #endif
853 
854 /* clk_prepare_enable helps cases using clk_enable in non-atomic context. */
855 static inline int clk_prepare_enable(struct clk *clk)
856 {
857         int ret;
858 
859         ret = clk_prepare(clk);
860         if (ret)
861                 return ret;
862         ret = clk_enable(clk);
863         if (ret)
864                 clk_unprepare(clk);
865 
866         return ret;
867 }
868 
869 /* clk_disable_unprepare helps cases using clk_disable in non-atomic context. */
870 static inline void clk_disable_unprepare(struct clk *clk)
871 {
872         clk_disable(clk);
873         clk_unprepare(clk);
874 }
875 
876 static inline int __must_check clk_bulk_prepare_enable(int num_clks,
877                                         struct clk_bulk_data *clks)
878 {
879         int ret;
880 
881         ret = clk_bulk_prepare(num_clks, clks);
882         if (ret)
883                 return ret;
884         ret = clk_bulk_enable(num_clks, clks);
885         if (ret)
886                 clk_bulk_unprepare(num_clks, clks);
887 
888         return ret;
889 }
890 
891 static inline void clk_bulk_disable_unprepare(int num_clks,
892                                               struct clk_bulk_data *clks)
893 {
894         clk_bulk_disable(num_clks, clks);
895         clk_bulk_unprepare(num_clks, clks);
896 }
897 
898 /**
899  * clk_get_optional - lookup and obtain a reference to an optional clock
900  *                    producer.
901  * @dev: device for clock "consumer"
902  * @id: clock consumer ID
903  *
904  * Behaves the same as clk_get() except where there is no clock producer. In
905  * this case, instead of returning -ENOENT, the function returns NULL.
906  */
907 static inline struct clk *clk_get_optional(struct device *dev, const char *id)
908 {
909         struct clk *clk = clk_get(dev, id);
910 
911         if (clk == ERR_PTR(-ENOENT))
912                 return NULL;
913 
914         return clk;
915 }
916 
917 #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
918 struct clk *of_clk_get(struct device_node *np, int index);
919 struct clk *of_clk_get_by_name(struct device_node *np, const char *name);
920 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec);
921 #else
922 static inline struct clk *of_clk_get(struct device_node *np, int index)
923 {
924         return ERR_PTR(-ENOENT);
925 }
926 static inline struct clk *of_clk_get_by_name(struct device_node *np,
927                                              const char *name)
928 {
929         return ERR_PTR(-ENOENT);
930 }
931 static inline struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
932 {
933         return ERR_PTR(-ENOENT);
934 }
935 #endif
936 
937 #endif
938 

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