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1da177e4 | 1 | /* |
f8ce2547 | 2 | * linux/include/linux/clk.h |
1da177e4 LT |
3 | * |
4 | * Copyright (C) 2004 ARM Limited. | |
5 | * Written by Deep Blue Solutions Limited. | |
b2476490 | 6 | * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org> |
1da177e4 LT |
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 | */ | |
686f8c5d TP |
12 | #ifndef __LINUX_CLK_H |
13 | #define __LINUX_CLK_H | |
1da177e4 | 14 | |
9f1612d3 | 15 | #include <linux/err.h> |
40d3e0f4 | 16 | #include <linux/kernel.h> |
b2476490 | 17 | #include <linux/notifier.h> |
40d3e0f4 | 18 | |
1da177e4 | 19 | struct device; |
b2476490 | 20 | struct clk; |
71a2f115 KM |
21 | struct device_node; |
22 | struct of_phandle_args; | |
b2476490 | 23 | |
b2476490 MT |
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 | |
fb72a059 SB |
30 | * rate change. Callbacks may either return NOTIFY_DONE, NOTIFY_OK, |
31 | * NOTIFY_STOP or NOTIFY_BAD. | |
b2476490 MT |
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 | |
fb72a059 | 36 | * always return NOTIFY_DONE or NOTIFY_OK. |
b2476490 MT |
37 | * |
38 | * POST_RATE_CHANGE - called after the clk rate change has successfully | |
fb72a059 | 39 | * completed. Callbacks must always return NOTIFY_DONE or NOTIFY_OK. |
b2476490 | 40 | * |
1da177e4 | 41 | */ |
b2476490 MT |
42 | #define PRE_RATE_CHANGE BIT(0) |
43 | #define POST_RATE_CHANGE BIT(1) | |
44 | #define ABORT_RATE_CHANGE BIT(2) | |
1da177e4 | 45 | |
b2476490 MT |
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 | }; | |
1da177e4 | 62 | |
b2476490 MT |
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). | |
1da177e4 | 73 | */ |
b2476490 MT |
74 | struct clk_notifier_data { |
75 | struct clk *clk; | |
76 | unsigned long old_rate; | |
77 | unsigned long new_rate; | |
78 | }; | |
79 | ||
e81b87d2 KK |
80 | #ifdef CONFIG_COMMON_CLK |
81 | ||
86bcfa2e MT |
82 | /** |
83 | * clk_notifier_register: register a clock rate-change notifier callback | |
84 | * @clk: clock whose rate we are interested in | |
85 | * @nb: notifier block with callback function pointer | |
86 | * | |
87 | * ProTip: debugging across notifier chains can be frustrating. Make sure that | |
88 | * your notifier callback function prints a nice big warning in case of | |
89 | * failure. | |
90 | */ | |
b2476490 MT |
91 | int clk_notifier_register(struct clk *clk, struct notifier_block *nb); |
92 | ||
86bcfa2e MT |
93 | /** |
94 | * clk_notifier_unregister: unregister a clock rate-change notifier callback | |
95 | * @clk: clock whose rate we are no longer interested in | |
96 | * @nb: notifier block which will be unregistered | |
97 | */ | |
b2476490 MT |
98 | int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb); |
99 | ||
5279fc40 BB |
100 | /** |
101 | * clk_get_accuracy - obtain the clock accuracy in ppb (parts per billion) | |
102 | * for a clock source. | |
103 | * @clk: clock source | |
104 | * | |
105 | * This gets the clock source accuracy expressed in ppb. | |
106 | * A perfect clock returns 0. | |
107 | */ | |
108 | long clk_get_accuracy(struct clk *clk); | |
109 | ||
e59c5371 MT |
110 | /** |
111 | * clk_set_phase - adjust the phase shift of a clock signal | |
112 | * @clk: clock signal source | |
113 | * @degrees: number of degrees the signal is shifted | |
114 | * | |
115 | * Shifts the phase of a clock signal by the specified degrees. Returns 0 on | |
116 | * success, -EERROR otherwise. | |
117 | */ | |
118 | int clk_set_phase(struct clk *clk, int degrees); | |
119 | ||
120 | /** | |
121 | * clk_get_phase - return the phase shift of a clock signal | |
122 | * @clk: clock signal source | |
123 | * | |
124 | * Returns the phase shift of a clock node in degrees, otherwise returns | |
125 | * -EERROR. | |
126 | */ | |
127 | int clk_get_phase(struct clk *clk); | |
128 | ||
3d3801ef MT |
129 | /** |
130 | * clk_is_match - check if two clk's point to the same hardware clock | |
131 | * @p: clk compared against q | |
132 | * @q: clk compared against p | |
133 | * | |
134 | * Returns true if the two struct clk pointers both point to the same hardware | |
135 | * clock node. Put differently, returns true if struct clk *p and struct clk *q | |
136 | * share the same struct clk_core object. | |
137 | * | |
138 | * Returns false otherwise. Note that two NULL clks are treated as matching. | |
139 | */ | |
140 | bool clk_is_match(const struct clk *p, const struct clk *q); | |
141 | ||
5279fc40 BB |
142 | #else |
143 | ||
e81b87d2 KK |
144 | static inline int clk_notifier_register(struct clk *clk, |
145 | struct notifier_block *nb) | |
146 | { | |
147 | return -ENOTSUPP; | |
148 | } | |
149 | ||
150 | static inline int clk_notifier_unregister(struct clk *clk, | |
151 | struct notifier_block *nb) | |
152 | { | |
153 | return -ENOTSUPP; | |
154 | } | |
155 | ||
5279fc40 BB |
156 | static inline long clk_get_accuracy(struct clk *clk) |
157 | { | |
158 | return -ENOTSUPP; | |
159 | } | |
160 | ||
e59c5371 MT |
161 | static inline long clk_set_phase(struct clk *clk, int phase) |
162 | { | |
163 | return -ENOTSUPP; | |
164 | } | |
165 | ||
166 | static inline long clk_get_phase(struct clk *clk) | |
167 | { | |
168 | return -ENOTSUPP; | |
169 | } | |
170 | ||
3d3801ef MT |
171 | static inline bool clk_is_match(const struct clk *p, const struct clk *q) |
172 | { | |
173 | return p == q; | |
174 | } | |
175 | ||
7e87aed9 | 176 | #endif |
1da177e4 | 177 | |
93abe8e4 VK |
178 | /** |
179 | * clk_prepare - prepare a clock source | |
180 | * @clk: clock source | |
181 | * | |
182 | * This prepares the clock source for use. | |
183 | * | |
184 | * Must not be called from within atomic context. | |
185 | */ | |
186 | #ifdef CONFIG_HAVE_CLK_PREPARE | |
187 | int clk_prepare(struct clk *clk); | |
188 | #else | |
189 | static inline int clk_prepare(struct clk *clk) | |
190 | { | |
191 | might_sleep(); | |
192 | return 0; | |
193 | } | |
194 | #endif | |
195 | ||
196 | /** | |
197 | * clk_unprepare - undo preparation of a clock source | |
198 | * @clk: clock source | |
199 | * | |
200 | * This undoes a previously prepared clock. The caller must balance | |
201 | * the number of prepare and unprepare calls. | |
202 | * | |
203 | * Must not be called from within atomic context. | |
204 | */ | |
205 | #ifdef CONFIG_HAVE_CLK_PREPARE | |
206 | void clk_unprepare(struct clk *clk); | |
207 | #else | |
208 | static inline void clk_unprepare(struct clk *clk) | |
209 | { | |
210 | might_sleep(); | |
211 | } | |
212 | #endif | |
213 | ||
214 | #ifdef CONFIG_HAVE_CLK | |
1da177e4 LT |
215 | /** |
216 | * clk_get - lookup and obtain a reference to a clock producer. | |
217 | * @dev: device for clock "consumer" | |
a58b3a4a | 218 | * @id: clock consumer ID |
1da177e4 LT |
219 | * |
220 | * Returns a struct clk corresponding to the clock producer, or | |
ea3f4eac RK |
221 | * valid IS_ERR() condition containing errno. The implementation |
222 | * uses @dev and @id to determine the clock consumer, and thereby | |
223 | * the clock producer. (IOW, @id may be identical strings, but | |
224 | * clk_get may return different clock producers depending on @dev.) | |
f47fc0ac RK |
225 | * |
226 | * Drivers must assume that the clock source is not enabled. | |
f7ad160b AR |
227 | * |
228 | * clk_get should not be called from within interrupt context. | |
1da177e4 LT |
229 | */ |
230 | struct clk *clk_get(struct device *dev, const char *id); | |
231 | ||
a8a97db9 MB |
232 | /** |
233 | * devm_clk_get - lookup and obtain a managed reference to a clock producer. | |
234 | * @dev: device for clock "consumer" | |
a58b3a4a | 235 | * @id: clock consumer ID |
a8a97db9 MB |
236 | * |
237 | * Returns a struct clk corresponding to the clock producer, or | |
238 | * valid IS_ERR() condition containing errno. The implementation | |
239 | * uses @dev and @id to determine the clock consumer, and thereby | |
240 | * the clock producer. (IOW, @id may be identical strings, but | |
241 | * clk_get may return different clock producers depending on @dev.) | |
242 | * | |
243 | * Drivers must assume that the clock source is not enabled. | |
244 | * | |
245 | * devm_clk_get should not be called from within interrupt context. | |
246 | * | |
247 | * The clock will automatically be freed when the device is unbound | |
248 | * from the bus. | |
249 | */ | |
250 | struct clk *devm_clk_get(struct device *dev, const char *id); | |
251 | ||
71a2f115 KM |
252 | /** |
253 | * devm_get_clk_from_child - lookup and obtain a managed reference to a | |
254 | * clock producer from child node. | |
255 | * @dev: device for clock "consumer" | |
256 | * @np: pointer to clock consumer node | |
257 | * @con_id: clock consumer ID | |
258 | * | |
259 | * This function parses the clocks, and uses them to look up the | |
260 | * struct clk from the registered list of clock providers by using | |
261 | * @np and @con_id | |
262 | * | |
263 | * The clock will automatically be freed when the device is unbound | |
264 | * from the bus. | |
265 | */ | |
266 | struct clk *devm_get_clk_from_child(struct device *dev, | |
267 | struct device_node *np, const char *con_id); | |
268 | ||
1da177e4 LT |
269 | /** |
270 | * clk_enable - inform the system when the clock source should be running. | |
271 | * @clk: clock source | |
272 | * | |
273 | * If the clock can not be enabled/disabled, this should return success. | |
274 | * | |
40d3e0f4 RK |
275 | * May be called from atomic contexts. |
276 | * | |
1da177e4 LT |
277 | * Returns success (0) or negative errno. |
278 | */ | |
279 | int clk_enable(struct clk *clk); | |
280 | ||
281 | /** | |
282 | * clk_disable - inform the system when the clock source is no longer required. | |
283 | * @clk: clock source | |
f47fc0ac RK |
284 | * |
285 | * Inform the system that a clock source is no longer required by | |
286 | * a driver and may be shut down. | |
287 | * | |
40d3e0f4 RK |
288 | * May be called from atomic contexts. |
289 | * | |
f47fc0ac RK |
290 | * Implementation detail: if the clock source is shared between |
291 | * multiple drivers, clk_enable() calls must be balanced by the | |
292 | * same number of clk_disable() calls for the clock source to be | |
293 | * disabled. | |
1da177e4 LT |
294 | */ |
295 | void clk_disable(struct clk *clk); | |
296 | ||
1da177e4 LT |
297 | /** |
298 | * clk_get_rate - obtain the current clock rate (in Hz) for a clock source. | |
299 | * This is only valid once the clock source has been enabled. | |
300 | * @clk: clock source | |
301 | */ | |
302 | unsigned long clk_get_rate(struct clk *clk); | |
303 | ||
304 | /** | |
305 | * clk_put - "free" the clock source | |
306 | * @clk: clock source | |
f47fc0ac RK |
307 | * |
308 | * Note: drivers must ensure that all clk_enable calls made on this | |
309 | * clock source are balanced by clk_disable calls prior to calling | |
310 | * this function. | |
f7ad160b AR |
311 | * |
312 | * clk_put should not be called from within interrupt context. | |
1da177e4 LT |
313 | */ |
314 | void clk_put(struct clk *clk); | |
315 | ||
a8a97db9 MB |
316 | /** |
317 | * devm_clk_put - "free" a managed clock source | |
da3dae54 | 318 | * @dev: device used to acquire the clock |
a8a97db9 MB |
319 | * @clk: clock source acquired with devm_clk_get() |
320 | * | |
321 | * Note: drivers must ensure that all clk_enable calls made on this | |
322 | * clock source are balanced by clk_disable calls prior to calling | |
323 | * this function. | |
324 | * | |
325 | * clk_put should not be called from within interrupt context. | |
326 | */ | |
327 | void devm_clk_put(struct device *dev, struct clk *clk); | |
1da177e4 LT |
328 | |
329 | /* | |
330 | * The remaining APIs are optional for machine class support. | |
331 | */ | |
332 | ||
333 | ||
334 | /** | |
335 | * clk_round_rate - adjust a rate to the exact rate a clock can provide | |
336 | * @clk: clock source | |
337 | * @rate: desired clock rate in Hz | |
338 | * | |
d2d14a77 RK |
339 | * This answers the question "if I were to pass @rate to clk_set_rate(), |
340 | * what clock rate would I end up with?" without changing the hardware | |
341 | * in any way. In other words: | |
342 | * | |
343 | * rate = clk_round_rate(clk, r); | |
344 | * | |
345 | * and: | |
346 | * | |
347 | * clk_set_rate(clk, r); | |
348 | * rate = clk_get_rate(clk); | |
349 | * | |
350 | * are equivalent except the former does not modify the clock hardware | |
351 | * in any way. | |
352 | * | |
1da177e4 LT |
353 | * Returns rounded clock rate in Hz, or negative errno. |
354 | */ | |
355 | long clk_round_rate(struct clk *clk, unsigned long rate); | |
8b7730dd | 356 | |
1da177e4 LT |
357 | /** |
358 | * clk_set_rate - set the clock rate for a clock source | |
359 | * @clk: clock source | |
360 | * @rate: desired clock rate in Hz | |
361 | * | |
362 | * Returns success (0) or negative errno. | |
363 | */ | |
364 | int clk_set_rate(struct clk *clk, unsigned long rate); | |
8b7730dd | 365 | |
4e88f3de TR |
366 | /** |
367 | * clk_has_parent - check if a clock is a possible parent for another | |
368 | * @clk: clock source | |
369 | * @parent: parent clock source | |
370 | * | |
371 | * This function can be used in drivers that need to check that a clock can be | |
372 | * the parent of another without actually changing the parent. | |
373 | * | |
374 | * Returns true if @parent is a possible parent for @clk, false otherwise. | |
375 | */ | |
376 | bool clk_has_parent(struct clk *clk, struct clk *parent); | |
377 | ||
1c8e6004 TV |
378 | /** |
379 | * clk_set_rate_range - set a rate range for a clock source | |
380 | * @clk: clock source | |
381 | * @min: desired minimum clock rate in Hz, inclusive | |
382 | * @max: desired maximum clock rate in Hz, inclusive | |
383 | * | |
384 | * Returns success (0) or negative errno. | |
385 | */ | |
386 | int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max); | |
387 | ||
388 | /** | |
389 | * clk_set_min_rate - set a minimum clock rate for a clock source | |
390 | * @clk: clock source | |
391 | * @rate: desired minimum clock rate in Hz, inclusive | |
392 | * | |
393 | * Returns success (0) or negative errno. | |
394 | */ | |
395 | int clk_set_min_rate(struct clk *clk, unsigned long rate); | |
396 | ||
397 | /** | |
398 | * clk_set_max_rate - set a maximum clock rate for a clock source | |
399 | * @clk: clock source | |
400 | * @rate: desired maximum clock rate in Hz, inclusive | |
401 | * | |
402 | * Returns success (0) or negative errno. | |
403 | */ | |
404 | int clk_set_max_rate(struct clk *clk, unsigned long rate); | |
405 | ||
1da177e4 LT |
406 | /** |
407 | * clk_set_parent - set the parent clock source for this clock | |
408 | * @clk: clock source | |
409 | * @parent: parent clock source | |
410 | * | |
411 | * Returns success (0) or negative errno. | |
412 | */ | |
413 | int clk_set_parent(struct clk *clk, struct clk *parent); | |
414 | ||
415 | /** | |
416 | * clk_get_parent - get the parent clock source for this clock | |
417 | * @clk: clock source | |
418 | * | |
419 | * Returns struct clk corresponding to parent clock source, or | |
420 | * valid IS_ERR() condition containing errno. | |
421 | */ | |
422 | struct clk *clk_get_parent(struct clk *clk); | |
423 | ||
05fd8e73 SH |
424 | /** |
425 | * clk_get_sys - get a clock based upon the device name | |
426 | * @dev_id: device name | |
427 | * @con_id: connection ID | |
428 | * | |
429 | * Returns a struct clk corresponding to the clock producer, or | |
430 | * valid IS_ERR() condition containing errno. The implementation | |
431 | * uses @dev_id and @con_id to determine the clock consumer, and | |
432 | * thereby the clock producer. In contrast to clk_get() this function | |
433 | * takes the device name instead of the device itself for identification. | |
434 | * | |
435 | * Drivers must assume that the clock source is not enabled. | |
436 | * | |
437 | * clk_get_sys should not be called from within interrupt context. | |
438 | */ | |
439 | struct clk *clk_get_sys(const char *dev_id, const char *con_id); | |
440 | ||
93abe8e4 VK |
441 | #else /* !CONFIG_HAVE_CLK */ |
442 | ||
443 | static inline struct clk *clk_get(struct device *dev, const char *id) | |
444 | { | |
445 | return NULL; | |
446 | } | |
447 | ||
448 | static inline struct clk *devm_clk_get(struct device *dev, const char *id) | |
449 | { | |
450 | return NULL; | |
451 | } | |
452 | ||
71a2f115 KM |
453 | static inline struct clk *devm_get_clk_from_child(struct device *dev, |
454 | struct device_node *np, const char *con_id) | |
455 | { | |
456 | return NULL; | |
457 | } | |
458 | ||
93abe8e4 VK |
459 | static inline void clk_put(struct clk *clk) {} |
460 | ||
461 | static inline void devm_clk_put(struct device *dev, struct clk *clk) {} | |
462 | ||
463 | static inline int clk_enable(struct clk *clk) | |
464 | { | |
465 | return 0; | |
466 | } | |
467 | ||
468 | static inline void clk_disable(struct clk *clk) {} | |
469 | ||
470 | static inline unsigned long clk_get_rate(struct clk *clk) | |
471 | { | |
472 | return 0; | |
473 | } | |
474 | ||
475 | static inline int clk_set_rate(struct clk *clk, unsigned long rate) | |
476 | { | |
477 | return 0; | |
478 | } | |
479 | ||
480 | static inline long clk_round_rate(struct clk *clk, unsigned long rate) | |
481 | { | |
482 | return 0; | |
483 | } | |
484 | ||
4e88f3de TR |
485 | static inline bool clk_has_parent(struct clk *clk, struct clk *parent) |
486 | { | |
487 | return true; | |
488 | } | |
489 | ||
93abe8e4 VK |
490 | static inline int clk_set_parent(struct clk *clk, struct clk *parent) |
491 | { | |
492 | return 0; | |
493 | } | |
494 | ||
495 | static inline struct clk *clk_get_parent(struct clk *clk) | |
496 | { | |
497 | return NULL; | |
498 | } | |
499 | ||
b81ea968 DL |
500 | static inline struct clk *clk_get_sys(const char *dev_id, const char *con_id) |
501 | { | |
502 | return NULL; | |
503 | } | |
93abe8e4 VK |
504 | #endif |
505 | ||
506 | /* clk_prepare_enable helps cases using clk_enable in non-atomic context. */ | |
507 | static inline int clk_prepare_enable(struct clk *clk) | |
508 | { | |
509 | int ret; | |
510 | ||
511 | ret = clk_prepare(clk); | |
512 | if (ret) | |
513 | return ret; | |
514 | ret = clk_enable(clk); | |
515 | if (ret) | |
516 | clk_unprepare(clk); | |
517 | ||
518 | return ret; | |
519 | } | |
520 | ||
521 | /* clk_disable_unprepare helps cases using clk_disable in non-atomic context. */ | |
522 | static inline void clk_disable_unprepare(struct clk *clk) | |
523 | { | |
524 | clk_disable(clk); | |
525 | clk_unprepare(clk); | |
526 | } | |
527 | ||
137f8a72 | 528 | #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) |
766e6a4e GL |
529 | struct clk *of_clk_get(struct device_node *np, int index); |
530 | struct clk *of_clk_get_by_name(struct device_node *np, const char *name); | |
531 | struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec); | |
532 | #else | |
533 | static inline struct clk *of_clk_get(struct device_node *np, int index) | |
534 | { | |
9f1612d3 | 535 | return ERR_PTR(-ENOENT); |
766e6a4e GL |
536 | } |
537 | static inline struct clk *of_clk_get_by_name(struct device_node *np, | |
538 | const char *name) | |
539 | { | |
9f1612d3 | 540 | return ERR_PTR(-ENOENT); |
766e6a4e GL |
541 | } |
542 | #endif | |
543 | ||
1da177e4 | 544 | #endif |