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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Russell Kingf8ce2542006-01-07 16:15:52 +00002 * linux/include/linux/clk.h
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
4 * Copyright (C) 2004 ARM Limited.
5 * Written by Deep Blue Solutions Limited.
Mike Turquetteb24764902012-03-15 23:11:19 -07006 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 *
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 */
Todd Poynor686f8c52006-03-25 18:15:24 +000012#ifndef __LINUX_CLK_H
13#define __LINUX_CLK_H
Linus Torvalds1da177e2005-04-16 15:20:36 -070014
Shawn Guo9f1612d2012-07-18 11:52:22 +080015#include <linux/err.h>
Russell King40d3e0f2011-09-22 11:30:50 +010016#include <linux/kernel.h>
Mike Turquetteb24764902012-03-15 23:11:19 -070017#include <linux/notifier.h>
Russell King40d3e0f2011-09-22 11:30:50 +010018
Linus Torvalds1da177e2005-04-16 15:20:36 -070019struct device;
20
Linus Torvalds1da177e2005-04-16 15:20:36 -070021struct clk;
22
Mike Turquetteb24764902012-03-15 23:11:19 -070023/**
24 * DOC: clk notifier callback types
25 *
26 * PRE_RATE_CHANGE - called immediately before the clk rate is changed,
27 * to indicate that the rate change will proceed. Drivers must
28 * immediately terminate any operations that will be affected by the
Soren Brinkmannfb72a052013-04-03 12:17:12 -070029 * rate change. Callbacks may either return NOTIFY_DONE, NOTIFY_OK,
30 * NOTIFY_STOP or NOTIFY_BAD.
Mike Turquetteb24764902012-03-15 23:11:19 -070031 *
32 * ABORT_RATE_CHANGE: called if the rate change failed for some reason
33 * after PRE_RATE_CHANGE. In this case, all registered notifiers on
34 * the clk will be called with ABORT_RATE_CHANGE. Callbacks must
Soren Brinkmannfb72a052013-04-03 12:17:12 -070035 * always return NOTIFY_DONE or NOTIFY_OK.
Mike Turquetteb24764902012-03-15 23:11:19 -070036 *
37 * POST_RATE_CHANGE - called after the clk rate change has successfully
Soren Brinkmannfb72a052013-04-03 12:17:12 -070038 * completed. Callbacks must always return NOTIFY_DONE or NOTIFY_OK.
Mike Turquetteb24764902012-03-15 23:11:19 -070039 *
40 */
41#define PRE_RATE_CHANGE BIT(0)
42#define POST_RATE_CHANGE BIT(1)
43#define ABORT_RATE_CHANGE BIT(2)
44
45/**
46 * struct clk_notifier - associate a clk with a notifier
47 * @clk: struct clk * to associate the notifier with
48 * @notifier_head: a blocking_notifier_head for this clk
49 * @node: linked list pointers
50 *
51 * A list of struct clk_notifier is maintained by the notifier code.
52 * An entry is created whenever code registers the first notifier on a
53 * particular @clk. Future notifiers on that @clk are added to the
54 * @notifier_head.
55 */
56struct clk_notifier {
57 struct clk *clk;
58 struct srcu_notifier_head notifier_head;
59 struct list_head node;
60};
61
62/**
63 * struct clk_notifier_data - rate data to pass to the notifier callback
64 * @clk: struct clk * being changed
65 * @old_rate: previous rate of this clk
66 * @new_rate: new rate of this clk
67 *
68 * For a pre-notifier, old_rate is the clk's rate before this rate
69 * change, and new_rate is what the rate will be in the future. For a
70 * post-notifier, old_rate and new_rate are both set to the clk's
71 * current rate (this was done to optimize the implementation).
72 */
73struct clk_notifier_data {
74 struct clk *clk;
75 unsigned long old_rate;
76 unsigned long new_rate;
77};
78
Krzysztof Kozlowskie81b87d2016-06-28 13:25:04 +020079#ifdef CONFIG_COMMON_CLK
80
Mike Turquette86bcfa22014-02-24 16:08:41 -080081/**
82 * clk_notifier_register: register a clock rate-change notifier callback
83 * @clk: clock whose rate we are interested in
84 * @nb: notifier block with callback function pointer
85 *
86 * ProTip: debugging across notifier chains can be frustrating. Make sure that
87 * your notifier callback function prints a nice big warning in case of
88 * failure.
89 */
Mike Turquetteb24764902012-03-15 23:11:19 -070090int clk_notifier_register(struct clk *clk, struct notifier_block *nb);
91
Mike Turquette86bcfa22014-02-24 16:08:41 -080092/**
93 * clk_notifier_unregister: unregister a clock rate-change notifier callback
94 * @clk: clock whose rate we are no longer interested in
95 * @nb: notifier block which will be unregistered
96 */
Mike Turquetteb24764902012-03-15 23:11:19 -070097int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb);
98
Boris BREZILLON5279fc42013-12-21 10:34:47 +010099/**
100 * clk_get_accuracy - obtain the clock accuracy in ppb (parts per billion)
101 * for a clock source.
102 * @clk: clock source
103 *
104 * This gets the clock source accuracy expressed in ppb.
105 * A perfect clock returns 0.
106 */
107long clk_get_accuracy(struct clk *clk);
108
Mike Turquettee59c5372014-02-18 21:21:25 -0800109/**
110 * clk_set_phase - adjust the phase shift of a clock signal
111 * @clk: clock signal source
112 * @degrees: number of degrees the signal is shifted
113 *
114 * Shifts the phase of a clock signal by the specified degrees. Returns 0 on
115 * success, -EERROR otherwise.
116 */
117int clk_set_phase(struct clk *clk, int degrees);
118
119/**
120 * clk_get_phase - return the phase shift of a clock signal
121 * @clk: clock signal source
122 *
123 * Returns the phase shift of a clock node in degrees, otherwise returns
124 * -EERROR.
125 */
126int clk_get_phase(struct clk *clk);
127
Michael Turquette3d3801e2015-02-25 09:11:01 -0800128/**
129 * clk_is_match - check if two clk's point to the same hardware clock
130 * @p: clk compared against q
131 * @q: clk compared against p
132 *
133 * Returns true if the two struct clk pointers both point to the same hardware
134 * clock node. Put differently, returns true if struct clk *p and struct clk *q
135 * share the same struct clk_core object.
136 *
137 * Returns false otherwise. Note that two NULL clks are treated as matching.
138 */
139bool clk_is_match(const struct clk *p, const struct clk *q);
140
Boris BREZILLON5279fc42013-12-21 10:34:47 +0100141#else
142
Krzysztof Kozlowskie81b87d2016-06-28 13:25:04 +0200143static inline int clk_notifier_register(struct clk *clk,
144 struct notifier_block *nb)
145{
146 return -ENOTSUPP;
147}
148
149static inline int clk_notifier_unregister(struct clk *clk,
150 struct notifier_block *nb)
151{
152 return -ENOTSUPP;
153}
154
Boris BREZILLON5279fc42013-12-21 10:34:47 +0100155static inline long clk_get_accuracy(struct clk *clk)
156{
157 return -ENOTSUPP;
158}
159
Mike Turquettee59c5372014-02-18 21:21:25 -0800160static inline long clk_set_phase(struct clk *clk, int phase)
161{
162 return -ENOTSUPP;
163}
164
165static inline long clk_get_phase(struct clk *clk)
166{
167 return -ENOTSUPP;
168}
169
Michael Turquette3d3801e2015-02-25 09:11:01 -0800170static inline bool clk_is_match(const struct clk *p, const struct clk *q)
171{
172 return p == q;
173}
174
Mark Brown7e87aed2012-04-01 15:31:23 +0100175#endif
Mike Turquetteb24764902012-03-15 23:11:19 -0700176
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177/**
Viresh Kumar93abe8e2012-07-30 14:39:27 -0700178 * clk_prepare - prepare a clock source
179 * @clk: clock source
180 *
181 * This prepares the clock source for use.
182 *
183 * Must not be called from within atomic context.
184 */
185#ifdef CONFIG_HAVE_CLK_PREPARE
186int clk_prepare(struct clk *clk);
187#else
188static inline int clk_prepare(struct clk *clk)
189{
190 might_sleep();
191 return 0;
192}
193#endif
194
195/**
196 * clk_unprepare - undo preparation of a clock source
197 * @clk: clock source
198 *
199 * This undoes a previously prepared clock. The caller must balance
200 * the number of prepare and unprepare calls.
201 *
202 * Must not be called from within atomic context.
203 */
204#ifdef CONFIG_HAVE_CLK_PREPARE
205void clk_unprepare(struct clk *clk);
206#else
207static inline void clk_unprepare(struct clk *clk)
208{
209 might_sleep();
210}
211#endif
212
213#ifdef CONFIG_HAVE_CLK
214/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 * clk_get - lookup and obtain a reference to a clock producer.
216 * @dev: device for clock "consumer"
Jan-Simon Möllera58b3a42012-07-23 20:48:56 +0200217 * @id: clock consumer ID
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 *
219 * Returns a struct clk corresponding to the clock producer, or
Russell Kingea3f4ea2005-04-27 18:19:55 +0100220 * valid IS_ERR() condition containing errno. The implementation
221 * uses @dev and @id to determine the clock consumer, and thereby
222 * the clock producer. (IOW, @id may be identical strings, but
223 * clk_get may return different clock producers depending on @dev.)
Russell Kingf47fc0a2006-01-03 18:34:20 +0000224 *
225 * Drivers must assume that the clock source is not enabled.
Alex Raimondif7ad1602008-10-15 22:02:03 -0700226 *
227 * clk_get should not be called from within interrupt context.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 */
229struct clk *clk_get(struct device *dev, const char *id);
230
231/**
Mark Browna8a97db2012-04-05 11:42:09 +0100232 * devm_clk_get - lookup and obtain a managed reference to a clock producer.
233 * @dev: device for clock "consumer"
Jan-Simon Möllera58b3a42012-07-23 20:48:56 +0200234 * @id: clock consumer ID
Mark Browna8a97db2012-04-05 11:42:09 +0100235 *
236 * Returns a struct clk corresponding to the clock producer, or
237 * valid IS_ERR() condition containing errno. The implementation
238 * uses @dev and @id to determine the clock consumer, and thereby
239 * the clock producer. (IOW, @id may be identical strings, but
240 * clk_get may return different clock producers depending on @dev.)
241 *
242 * Drivers must assume that the clock source is not enabled.
243 *
244 * devm_clk_get should not be called from within interrupt context.
245 *
246 * The clock will automatically be freed when the device is unbound
247 * from the bus.
248 */
249struct clk *devm_clk_get(struct device *dev, const char *id);
250
251/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 * clk_enable - inform the system when the clock source should be running.
253 * @clk: clock source
254 *
255 * If the clock can not be enabled/disabled, this should return success.
256 *
Russell King40d3e0f2011-09-22 11:30:50 +0100257 * May be called from atomic contexts.
258 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 * Returns success (0) or negative errno.
260 */
261int clk_enable(struct clk *clk);
262
263/**
264 * clk_disable - inform the system when the clock source is no longer required.
265 * @clk: clock source
Russell Kingf47fc0a2006-01-03 18:34:20 +0000266 *
267 * Inform the system that a clock source is no longer required by
268 * a driver and may be shut down.
269 *
Russell King40d3e0f2011-09-22 11:30:50 +0100270 * May be called from atomic contexts.
271 *
Russell Kingf47fc0a2006-01-03 18:34:20 +0000272 * Implementation detail: if the clock source is shared between
273 * multiple drivers, clk_enable() calls must be balanced by the
274 * same number of clk_disable() calls for the clock source to be
275 * disabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 */
277void clk_disable(struct clk *clk);
278
279/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 * clk_get_rate - obtain the current clock rate (in Hz) for a clock source.
281 * This is only valid once the clock source has been enabled.
282 * @clk: clock source
283 */
284unsigned long clk_get_rate(struct clk *clk);
285
286/**
287 * clk_put - "free" the clock source
288 * @clk: clock source
Russell Kingf47fc0a2006-01-03 18:34:20 +0000289 *
290 * Note: drivers must ensure that all clk_enable calls made on this
291 * clock source are balanced by clk_disable calls prior to calling
292 * this function.
Alex Raimondif7ad1602008-10-15 22:02:03 -0700293 *
294 * clk_put should not be called from within interrupt context.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 */
296void clk_put(struct clk *clk);
297
Mark Browna8a97db2012-04-05 11:42:09 +0100298/**
299 * devm_clk_put - "free" a managed clock source
Masanari Iidada3dae52014-09-09 01:27:23 +0900300 * @dev: device used to acquire the clock
Mark Browna8a97db2012-04-05 11:42:09 +0100301 * @clk: clock source acquired with devm_clk_get()
302 *
303 * Note: drivers must ensure that all clk_enable calls made on this
304 * clock source are balanced by clk_disable calls prior to calling
305 * this function.
306 *
307 * clk_put should not be called from within interrupt context.
308 */
309void devm_clk_put(struct device *dev, struct clk *clk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310
311/*
312 * The remaining APIs are optional for machine class support.
313 */
314
315
316/**
317 * clk_round_rate - adjust a rate to the exact rate a clock can provide
318 * @clk: clock source
319 * @rate: desired clock rate in Hz
320 *
Russell Kingd2d14a72015-03-14 15:12:35 +0000321 * This answers the question "if I were to pass @rate to clk_set_rate(),
322 * what clock rate would I end up with?" without changing the hardware
323 * in any way. In other words:
324 *
325 * rate = clk_round_rate(clk, r);
326 *
327 * and:
328 *
329 * clk_set_rate(clk, r);
330 * rate = clk_get_rate(clk);
331 *
332 * are equivalent except the former does not modify the clock hardware
333 * in any way.
334 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 * Returns rounded clock rate in Hz, or negative errno.
336 */
337long clk_round_rate(struct clk *clk, unsigned long rate);
Rob Herring8b7730d2012-04-09 15:24:59 -0500338
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339/**
340 * clk_set_rate - set the clock rate for a clock source
341 * @clk: clock source
342 * @rate: desired clock rate in Hz
343 *
344 * Returns success (0) or negative errno.
345 */
346int clk_set_rate(struct clk *clk, unsigned long rate);
Rob Herring8b7730d2012-04-09 15:24:59 -0500347
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348/**
Thierry Reding4e88f3d2015-01-21 17:13:00 +0100349 * clk_has_parent - check if a clock is a possible parent for another
350 * @clk: clock source
351 * @parent: parent clock source
352 *
353 * This function can be used in drivers that need to check that a clock can be
354 * the parent of another without actually changing the parent.
355 *
356 * Returns true if @parent is a possible parent for @clk, false otherwise.
357 */
358bool clk_has_parent(struct clk *clk, struct clk *parent);
359
360/**
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +0100361 * clk_set_rate_range - set a rate range for a clock source
362 * @clk: clock source
363 * @min: desired minimum clock rate in Hz, inclusive
364 * @max: desired maximum clock rate in Hz, inclusive
365 *
366 * Returns success (0) or negative errno.
367 */
368int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max);
369
370/**
371 * clk_set_min_rate - set a minimum clock rate for a clock source
372 * @clk: clock source
373 * @rate: desired minimum clock rate in Hz, inclusive
374 *
375 * Returns success (0) or negative errno.
376 */
377int clk_set_min_rate(struct clk *clk, unsigned long rate);
378
379/**
380 * clk_set_max_rate - set a maximum clock rate for a clock source
381 * @clk: clock source
382 * @rate: desired maximum clock rate in Hz, inclusive
383 *
384 * Returns success (0) or negative errno.
385 */
386int clk_set_max_rate(struct clk *clk, unsigned long rate);
387
388/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 * clk_set_parent - set the parent clock source for this clock
390 * @clk: clock source
391 * @parent: parent clock source
392 *
393 * Returns success (0) or negative errno.
394 */
395int clk_set_parent(struct clk *clk, struct clk *parent);
396
397/**
398 * clk_get_parent - get the parent clock source for this clock
399 * @clk: clock source
400 *
401 * Returns struct clk corresponding to parent clock source, or
402 * valid IS_ERR() condition containing errno.
403 */
404struct clk *clk_get_parent(struct clk *clk);
405
Sascha Hauer05fd8e72009-03-07 12:55:49 +0100406/**
407 * clk_get_sys - get a clock based upon the device name
408 * @dev_id: device name
409 * @con_id: connection ID
410 *
411 * Returns a struct clk corresponding to the clock producer, or
412 * valid IS_ERR() condition containing errno. The implementation
413 * uses @dev_id and @con_id to determine the clock consumer, and
414 * thereby the clock producer. In contrast to clk_get() this function
415 * takes the device name instead of the device itself for identification.
416 *
417 * Drivers must assume that the clock source is not enabled.
418 *
419 * clk_get_sys should not be called from within interrupt context.
420 */
421struct clk *clk_get_sys(const char *dev_id, const char *con_id);
422
Viresh Kumar93abe8e2012-07-30 14:39:27 -0700423#else /* !CONFIG_HAVE_CLK */
424
425static inline struct clk *clk_get(struct device *dev, const char *id)
426{
427 return NULL;
428}
429
430static inline struct clk *devm_clk_get(struct device *dev, const char *id)
431{
432 return NULL;
433}
434
435static inline void clk_put(struct clk *clk) {}
436
437static inline void devm_clk_put(struct device *dev, struct clk *clk) {}
438
439static inline int clk_enable(struct clk *clk)
440{
441 return 0;
442}
443
444static inline void clk_disable(struct clk *clk) {}
445
446static inline unsigned long clk_get_rate(struct clk *clk)
447{
448 return 0;
449}
450
451static inline int clk_set_rate(struct clk *clk, unsigned long rate)
452{
453 return 0;
454}
455
456static inline long clk_round_rate(struct clk *clk, unsigned long rate)
457{
458 return 0;
459}
460
Thierry Reding4e88f3d2015-01-21 17:13:00 +0100461static inline bool clk_has_parent(struct clk *clk, struct clk *parent)
462{
463 return true;
464}
465
Viresh Kumar93abe8e2012-07-30 14:39:27 -0700466static inline int clk_set_parent(struct clk *clk, struct clk *parent)
467{
468 return 0;
469}
470
471static inline struct clk *clk_get_parent(struct clk *clk)
472{
473 return NULL;
474}
475
Daniel Lezcanob81ea962016-06-02 22:44:49 +0200476static inline struct clk *clk_get_sys(const char *dev_id, const char *con_id)
477{
478 return NULL;
479}
Viresh Kumar93abe8e2012-07-30 14:39:27 -0700480#endif
481
482/* clk_prepare_enable helps cases using clk_enable in non-atomic context. */
483static inline int clk_prepare_enable(struct clk *clk)
484{
485 int ret;
486
487 ret = clk_prepare(clk);
488 if (ret)
489 return ret;
490 ret = clk_enable(clk);
491 if (ret)
492 clk_unprepare(clk);
493
494 return ret;
495}
496
497/* clk_disable_unprepare helps cases using clk_disable in non-atomic context. */
498static inline void clk_disable_unprepare(struct clk *clk)
499{
500 clk_disable(clk);
501 clk_unprepare(clk);
502}
503
Grant Likely766e6a42012-04-09 14:50:06 -0500504struct device_node;
505struct of_phandle_args;
506
Rob Herring137f8a72012-07-18 11:52:23 +0800507#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
Grant Likely766e6a42012-04-09 14:50:06 -0500508struct clk *of_clk_get(struct device_node *np, int index);
509struct clk *of_clk_get_by_name(struct device_node *np, const char *name);
510struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec);
511#else
512static inline struct clk *of_clk_get(struct device_node *np, int index)
513{
Shawn Guo9f1612d2012-07-18 11:52:22 +0800514 return ERR_PTR(-ENOENT);
Grant Likely766e6a42012-04-09 14:50:06 -0500515}
516static inline struct clk *of_clk_get_by_name(struct device_node *np,
517 const char *name)
518{
Shawn Guo9f1612d2012-07-18 11:52:22 +0800519 return ERR_PTR(-ENOENT);
Grant Likely766e6a42012-04-09 14:50:06 -0500520}
521#endif
522
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523#endif