blob: 0df4a51e1a78d2bd74ac899c655bce9659ea50da [file] [log] [blame]
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#ifdef CONFIG_COMMON_CLK
24
25/**
26 * DOC: clk notifier callback types
27 *
28 * PRE_RATE_CHANGE - called immediately before the clk rate is changed,
29 * to indicate that the rate change will proceed. Drivers must
30 * immediately terminate any operations that will be affected by the
Soren Brinkmannfb72a052013-04-03 12:17:12 -070031 * rate change. Callbacks may either return NOTIFY_DONE, NOTIFY_OK,
32 * NOTIFY_STOP or NOTIFY_BAD.
Mike Turquetteb24764902012-03-15 23:11:19 -070033 *
34 * ABORT_RATE_CHANGE: called if the rate change failed for some reason
35 * after PRE_RATE_CHANGE. In this case, all registered notifiers on
36 * the clk will be called with ABORT_RATE_CHANGE. Callbacks must
Soren Brinkmannfb72a052013-04-03 12:17:12 -070037 * always return NOTIFY_DONE or NOTIFY_OK.
Mike Turquetteb24764902012-03-15 23:11:19 -070038 *
39 * POST_RATE_CHANGE - called after the clk rate change has successfully
Soren Brinkmannfb72a052013-04-03 12:17:12 -070040 * completed. Callbacks must always return NOTIFY_DONE or NOTIFY_OK.
Mike Turquetteb24764902012-03-15 23:11:19 -070041 *
42 */
43#define PRE_RATE_CHANGE BIT(0)
44#define POST_RATE_CHANGE BIT(1)
45#define ABORT_RATE_CHANGE BIT(2)
46
47/**
48 * struct clk_notifier - associate a clk with a notifier
49 * @clk: struct clk * to associate the notifier with
50 * @notifier_head: a blocking_notifier_head for this clk
51 * @node: linked list pointers
52 *
53 * A list of struct clk_notifier is maintained by the notifier code.
54 * An entry is created whenever code registers the first notifier on a
55 * particular @clk. Future notifiers on that @clk are added to the
56 * @notifier_head.
57 */
58struct clk_notifier {
59 struct clk *clk;
60 struct srcu_notifier_head notifier_head;
61 struct list_head node;
62};
63
64/**
65 * struct clk_notifier_data - rate data to pass to the notifier callback
66 * @clk: struct clk * being changed
67 * @old_rate: previous rate of this clk
68 * @new_rate: new rate of this clk
69 *
70 * For a pre-notifier, old_rate is the clk's rate before this rate
71 * change, and new_rate is what the rate will be in the future. For a
72 * post-notifier, old_rate and new_rate are both set to the clk's
73 * current rate (this was done to optimize the implementation).
74 */
75struct clk_notifier_data {
76 struct clk *clk;
77 unsigned long old_rate;
78 unsigned long new_rate;
79};
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
143static inline long clk_get_accuracy(struct clk *clk)
144{
145 return -ENOTSUPP;
146}
147
Mike Turquettee59c5372014-02-18 21:21:25 -0800148static inline long clk_set_phase(struct clk *clk, int phase)
149{
150 return -ENOTSUPP;
151}
152
153static inline long clk_get_phase(struct clk *clk)
154{
155 return -ENOTSUPP;
156}
157
Michael Turquette3d3801e2015-02-25 09:11:01 -0800158static inline bool clk_is_match(const struct clk *p, const struct clk *q)
159{
160 return p == q;
161}
162
Mark Brown7e87aed2012-04-01 15:31:23 +0100163#endif
Mike Turquetteb24764902012-03-15 23:11:19 -0700164
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165/**
Viresh Kumar93abe8e2012-07-30 14:39:27 -0700166 * clk_prepare - prepare a clock source
167 * @clk: clock source
168 *
169 * This prepares the clock source for use.
170 *
171 * Must not be called from within atomic context.
172 */
173#ifdef CONFIG_HAVE_CLK_PREPARE
174int clk_prepare(struct clk *clk);
175#else
176static inline int clk_prepare(struct clk *clk)
177{
178 might_sleep();
179 return 0;
180}
181#endif
182
183/**
184 * clk_unprepare - undo preparation of a clock source
185 * @clk: clock source
186 *
187 * This undoes a previously prepared clock. The caller must balance
188 * the number of prepare and unprepare calls.
189 *
190 * Must not be called from within atomic context.
191 */
192#ifdef CONFIG_HAVE_CLK_PREPARE
193void clk_unprepare(struct clk *clk);
194#else
195static inline void clk_unprepare(struct clk *clk)
196{
197 might_sleep();
198}
199#endif
200
201#ifdef CONFIG_HAVE_CLK
202/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 * clk_get - lookup and obtain a reference to a clock producer.
204 * @dev: device for clock "consumer"
Jan-Simon Möllera58b3a42012-07-23 20:48:56 +0200205 * @id: clock consumer ID
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 *
207 * Returns a struct clk corresponding to the clock producer, or
Russell Kingea3f4ea2005-04-27 18:19:55 +0100208 * valid IS_ERR() condition containing errno. The implementation
209 * uses @dev and @id to determine the clock consumer, and thereby
210 * the clock producer. (IOW, @id may be identical strings, but
211 * clk_get may return different clock producers depending on @dev.)
Russell Kingf47fc0a2006-01-03 18:34:20 +0000212 *
213 * Drivers must assume that the clock source is not enabled.
Alex Raimondif7ad1602008-10-15 22:02:03 -0700214 *
215 * clk_get should not be called from within interrupt context.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 */
217struct clk *clk_get(struct device *dev, const char *id);
218
219/**
Mark Browna8a97db2012-04-05 11:42:09 +0100220 * devm_clk_get - lookup and obtain a managed reference to a clock producer.
221 * @dev: device for clock "consumer"
Jan-Simon Möllera58b3a42012-07-23 20:48:56 +0200222 * @id: clock consumer ID
Mark Browna8a97db2012-04-05 11:42:09 +0100223 *
224 * Returns a struct clk corresponding to the clock producer, or
225 * valid IS_ERR() condition containing errno. The implementation
226 * uses @dev and @id to determine the clock consumer, and thereby
227 * the clock producer. (IOW, @id may be identical strings, but
228 * clk_get may return different clock producers depending on @dev.)
229 *
230 * Drivers must assume that the clock source is not enabled.
231 *
232 * devm_clk_get should not be called from within interrupt context.
233 *
234 * The clock will automatically be freed when the device is unbound
235 * from the bus.
236 */
237struct clk *devm_clk_get(struct device *dev, const char *id);
238
239/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 * clk_enable - inform the system when the clock source should be running.
241 * @clk: clock source
242 *
243 * If the clock can not be enabled/disabled, this should return success.
244 *
Russell King40d3e0f2011-09-22 11:30:50 +0100245 * May be called from atomic contexts.
246 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 * Returns success (0) or negative errno.
248 */
249int clk_enable(struct clk *clk);
250
251/**
252 * clk_disable - inform the system when the clock source is no longer required.
253 * @clk: clock source
Russell Kingf47fc0a2006-01-03 18:34:20 +0000254 *
255 * Inform the system that a clock source is no longer required by
256 * a driver and may be shut down.
257 *
Russell King40d3e0f2011-09-22 11:30:50 +0100258 * May be called from atomic contexts.
259 *
Russell Kingf47fc0a2006-01-03 18:34:20 +0000260 * Implementation detail: if the clock source is shared between
261 * multiple drivers, clk_enable() calls must be balanced by the
262 * same number of clk_disable() calls for the clock source to be
263 * disabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 */
265void clk_disable(struct clk *clk);
266
267/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 * clk_get_rate - obtain the current clock rate (in Hz) for a clock source.
269 * This is only valid once the clock source has been enabled.
270 * @clk: clock source
271 */
272unsigned long clk_get_rate(struct clk *clk);
273
274/**
275 * clk_put - "free" the clock source
276 * @clk: clock source
Russell Kingf47fc0a2006-01-03 18:34:20 +0000277 *
278 * Note: drivers must ensure that all clk_enable calls made on this
279 * clock source are balanced by clk_disable calls prior to calling
280 * this function.
Alex Raimondif7ad1602008-10-15 22:02:03 -0700281 *
282 * clk_put should not be called from within interrupt context.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 */
284void clk_put(struct clk *clk);
285
Mark Browna8a97db2012-04-05 11:42:09 +0100286/**
287 * devm_clk_put - "free" a managed clock source
Masanari Iidada3dae52014-09-09 01:27:23 +0900288 * @dev: device used to acquire the clock
Mark Browna8a97db2012-04-05 11:42:09 +0100289 * @clk: clock source acquired with devm_clk_get()
290 *
291 * Note: drivers must ensure that all clk_enable calls made on this
292 * clock source are balanced by clk_disable calls prior to calling
293 * this function.
294 *
295 * clk_put should not be called from within interrupt context.
296 */
297void devm_clk_put(struct device *dev, struct clk *clk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298
299/*
300 * The remaining APIs are optional for machine class support.
301 */
302
303
304/**
305 * clk_round_rate - adjust a rate to the exact rate a clock can provide
306 * @clk: clock source
307 * @rate: desired clock rate in Hz
308 *
Russell Kingd2d14a72015-03-14 15:12:35 +0000309 * This answers the question "if I were to pass @rate to clk_set_rate(),
310 * what clock rate would I end up with?" without changing the hardware
311 * in any way. In other words:
312 *
313 * rate = clk_round_rate(clk, r);
314 *
315 * and:
316 *
317 * clk_set_rate(clk, r);
318 * rate = clk_get_rate(clk);
319 *
320 * are equivalent except the former does not modify the clock hardware
321 * in any way.
322 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 * Returns rounded clock rate in Hz, or negative errno.
324 */
325long clk_round_rate(struct clk *clk, unsigned long rate);
Rob Herring8b7730d2012-04-09 15:24:59 -0500326
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327/**
328 * clk_set_rate - set the clock rate for a clock source
329 * @clk: clock source
330 * @rate: desired clock rate in Hz
331 *
332 * Returns success (0) or negative errno.
333 */
334int clk_set_rate(struct clk *clk, unsigned long rate);
Rob Herring8b7730d2012-04-09 15:24:59 -0500335
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336/**
Thierry Reding4e88f3d2015-01-21 17:13:00 +0100337 * clk_has_parent - check if a clock is a possible parent for another
338 * @clk: clock source
339 * @parent: parent clock source
340 *
341 * This function can be used in drivers that need to check that a clock can be
342 * the parent of another without actually changing the parent.
343 *
344 * Returns true if @parent is a possible parent for @clk, false otherwise.
345 */
346bool clk_has_parent(struct clk *clk, struct clk *parent);
347
348/**
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +0100349 * clk_set_rate_range - set a rate range for a clock source
350 * @clk: clock source
351 * @min: desired minimum clock rate in Hz, inclusive
352 * @max: desired maximum clock rate in Hz, inclusive
353 *
354 * Returns success (0) or negative errno.
355 */
356int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max);
357
358/**
359 * clk_set_min_rate - set a minimum clock rate for a clock source
360 * @clk: clock source
361 * @rate: desired minimum clock rate in Hz, inclusive
362 *
363 * Returns success (0) or negative errno.
364 */
365int clk_set_min_rate(struct clk *clk, unsigned long rate);
366
367/**
368 * clk_set_max_rate - set a maximum clock rate for a clock source
369 * @clk: clock source
370 * @rate: desired maximum clock rate in Hz, inclusive
371 *
372 * Returns success (0) or negative errno.
373 */
374int clk_set_max_rate(struct clk *clk, unsigned long rate);
375
376/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 * clk_set_parent - set the parent clock source for this clock
378 * @clk: clock source
379 * @parent: parent clock source
380 *
381 * Returns success (0) or negative errno.
382 */
383int clk_set_parent(struct clk *clk, struct clk *parent);
384
385/**
386 * clk_get_parent - get the parent clock source for this clock
387 * @clk: clock source
388 *
389 * Returns struct clk corresponding to parent clock source, or
390 * valid IS_ERR() condition containing errno.
391 */
392struct clk *clk_get_parent(struct clk *clk);
393
Sascha Hauer05fd8e72009-03-07 12:55:49 +0100394/**
395 * clk_get_sys - get a clock based upon the device name
396 * @dev_id: device name
397 * @con_id: connection ID
398 *
399 * Returns a struct clk corresponding to the clock producer, or
400 * valid IS_ERR() condition containing errno. The implementation
401 * uses @dev_id and @con_id to determine the clock consumer, and
402 * thereby the clock producer. In contrast to clk_get() this function
403 * takes the device name instead of the device itself for identification.
404 *
405 * Drivers must assume that the clock source is not enabled.
406 *
407 * clk_get_sys should not be called from within interrupt context.
408 */
409struct clk *clk_get_sys(const char *dev_id, const char *con_id);
410
Viresh Kumar93abe8e2012-07-30 14:39:27 -0700411#else /* !CONFIG_HAVE_CLK */
412
413static inline struct clk *clk_get(struct device *dev, const char *id)
414{
415 return NULL;
416}
417
418static inline struct clk *devm_clk_get(struct device *dev, const char *id)
419{
420 return NULL;
421}
422
423static inline void clk_put(struct clk *clk) {}
424
425static inline void devm_clk_put(struct device *dev, struct clk *clk) {}
426
427static inline int clk_enable(struct clk *clk)
428{
429 return 0;
430}
431
432static inline void clk_disable(struct clk *clk) {}
433
434static inline unsigned long clk_get_rate(struct clk *clk)
435{
436 return 0;
437}
438
439static inline int clk_set_rate(struct clk *clk, unsigned long rate)
440{
441 return 0;
442}
443
444static inline long clk_round_rate(struct clk *clk, unsigned long rate)
445{
446 return 0;
447}
448
Thierry Reding4e88f3d2015-01-21 17:13:00 +0100449static inline bool clk_has_parent(struct clk *clk, struct clk *parent)
450{
451 return true;
452}
453
Viresh Kumar93abe8e2012-07-30 14:39:27 -0700454static inline int clk_set_parent(struct clk *clk, struct clk *parent)
455{
456 return 0;
457}
458
459static inline struct clk *clk_get_parent(struct clk *clk)
460{
461 return NULL;
462}
463
464#endif
465
466/* clk_prepare_enable helps cases using clk_enable in non-atomic context. */
467static inline int clk_prepare_enable(struct clk *clk)
468{
469 int ret;
470
471 ret = clk_prepare(clk);
472 if (ret)
473 return ret;
474 ret = clk_enable(clk);
475 if (ret)
476 clk_unprepare(clk);
477
478 return ret;
479}
480
481/* clk_disable_unprepare helps cases using clk_disable in non-atomic context. */
482static inline void clk_disable_unprepare(struct clk *clk)
483{
484 clk_disable(clk);
485 clk_unprepare(clk);
486}
487
Grant Likely766e6a42012-04-09 14:50:06 -0500488struct device_node;
489struct of_phandle_args;
490
Rob Herring137f8a72012-07-18 11:52:23 +0800491#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
Grant Likely766e6a42012-04-09 14:50:06 -0500492struct clk *of_clk_get(struct device_node *np, int index);
493struct clk *of_clk_get_by_name(struct device_node *np, const char *name);
494struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec);
495#else
496static inline struct clk *of_clk_get(struct device_node *np, int index)
497{
Shawn Guo9f1612d2012-07-18 11:52:22 +0800498 return ERR_PTR(-ENOENT);
Grant Likely766e6a42012-04-09 14:50:06 -0500499}
500static inline struct clk *of_clk_get_by_name(struct device_node *np,
501 const char *name)
502{
Shawn Guo9f1612d2012-07-18 11:52:22 +0800503 return ERR_PTR(-ENOENT);
Grant Likely766e6a42012-04-09 14:50:06 -0500504}
505#endif
506
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507#endif