Commit | Line | Data |
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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 LT |
19 | struct device; |
20 | ||
b2476490 MT |
21 | struct clk; |
22 | ||
23 | #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 | |
fb72a059 SB |
31 | * rate change. Callbacks may either return NOTIFY_DONE, NOTIFY_OK, |
32 | * NOTIFY_STOP or NOTIFY_BAD. | |
b2476490 MT |
33 | * |
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 | |
fb72a059 | 37 | * always return NOTIFY_DONE or NOTIFY_OK. |
b2476490 MT |
38 | * |
39 | * POST_RATE_CHANGE - called after the clk rate change has successfully | |
fb72a059 | 40 | * completed. Callbacks must always return NOTIFY_DONE or NOTIFY_OK. |
b2476490 | 41 | * |
1da177e4 | 42 | */ |
b2476490 MT |
43 | #define PRE_RATE_CHANGE BIT(0) |
44 | #define POST_RATE_CHANGE BIT(1) | |
45 | #define ABORT_RATE_CHANGE BIT(2) | |
1da177e4 | 46 | |
b2476490 MT |
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 | */ | |
58 | struct clk_notifier { | |
59 | struct clk *clk; | |
60 | struct srcu_notifier_head notifier_head; | |
61 | struct list_head node; | |
62 | }; | |
1da177e4 | 63 | |
b2476490 MT |
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). | |
1da177e4 | 74 | */ |
b2476490 MT |
75 | struct clk_notifier_data { |
76 | struct clk *clk; | |
77 | unsigned long old_rate; | |
78 | unsigned long new_rate; | |
79 | }; | |
80 | ||
86bcfa2e MT |
81 | /** |
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 | */ | |
b2476490 MT |
90 | int clk_notifier_register(struct clk *clk, struct notifier_block *nb); |
91 | ||
86bcfa2e MT |
92 | /** |
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 | */ | |
b2476490 MT |
97 | int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb); |
98 | ||
5279fc40 BB |
99 | /** |
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 | */ | |
107 | long clk_get_accuracy(struct clk *clk); | |
108 | ||
e59c5371 MT |
109 | /** |
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 | */ | |
117 | int 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 | */ | |
126 | int clk_get_phase(struct clk *clk); | |
127 | ||
3d3801ef MT |
128 | /** |
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 | */ | |
139 | bool clk_is_match(const struct clk *p, const struct clk *q); | |
140 | ||
5279fc40 BB |
141 | #else |
142 | ||
143 | static inline long clk_get_accuracy(struct clk *clk) | |
144 | { | |
145 | return -ENOTSUPP; | |
146 | } | |
147 | ||
e59c5371 MT |
148 | static inline long clk_set_phase(struct clk *clk, int phase) |
149 | { | |
150 | return -ENOTSUPP; | |
151 | } | |
152 | ||
153 | static inline long clk_get_phase(struct clk *clk) | |
154 | { | |
155 | return -ENOTSUPP; | |
156 | } | |
157 | ||
3d3801ef MT |
158 | static inline bool clk_is_match(const struct clk *p, const struct clk *q) |
159 | { | |
160 | return p == q; | |
161 | } | |
162 | ||
7e87aed9 | 163 | #endif |
1da177e4 | 164 | |
93abe8e4 VK |
165 | /** |
166 | * 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 | |
174 | int clk_prepare(struct clk *clk); | |
175 | #else | |
176 | static 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 | |
193 | void clk_unprepare(struct clk *clk); | |
194 | #else | |
195 | static inline void clk_unprepare(struct clk *clk) | |
196 | { | |
197 | might_sleep(); | |
198 | } | |
199 | #endif | |
200 | ||
201 | #ifdef CONFIG_HAVE_CLK | |
1da177e4 LT |
202 | /** |
203 | * clk_get - lookup and obtain a reference to a clock producer. | |
204 | * @dev: device for clock "consumer" | |
a58b3a4a | 205 | * @id: clock consumer ID |
1da177e4 LT |
206 | * |
207 | * Returns a struct clk corresponding to the clock producer, or | |
ea3f4eac RK |
208 | * 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.) | |
f47fc0ac RK |
212 | * |
213 | * Drivers must assume that the clock source is not enabled. | |
f7ad160b AR |
214 | * |
215 | * clk_get should not be called from within interrupt context. | |
1da177e4 LT |
216 | */ |
217 | struct clk *clk_get(struct device *dev, const char *id); | |
218 | ||
a8a97db9 MB |
219 | /** |
220 | * devm_clk_get - lookup and obtain a managed reference to a clock producer. | |
221 | * @dev: device for clock "consumer" | |
a58b3a4a | 222 | * @id: clock consumer ID |
a8a97db9 MB |
223 | * |
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 | */ | |
237 | struct clk *devm_clk_get(struct device *dev, const char *id); | |
238 | ||
1da177e4 LT |
239 | /** |
240 | * 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 | * | |
40d3e0f4 RK |
245 | * May be called from atomic contexts. |
246 | * | |
1da177e4 LT |
247 | * Returns success (0) or negative errno. |
248 | */ | |
249 | int 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 | |
f47fc0ac RK |
254 | * |
255 | * Inform the system that a clock source is no longer required by | |
256 | * a driver and may be shut down. | |
257 | * | |
40d3e0f4 RK |
258 | * May be called from atomic contexts. |
259 | * | |
f47fc0ac RK |
260 | * 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. | |
1da177e4 LT |
264 | */ |
265 | void clk_disable(struct clk *clk); | |
266 | ||
1da177e4 LT |
267 | /** |
268 | * 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 | */ | |
272 | unsigned long clk_get_rate(struct clk *clk); | |
273 | ||
274 | /** | |
275 | * clk_put - "free" the clock source | |
276 | * @clk: clock source | |
f47fc0ac RK |
277 | * |
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. | |
f7ad160b AR |
281 | * |
282 | * clk_put should not be called from within interrupt context. | |
1da177e4 LT |
283 | */ |
284 | void clk_put(struct clk *clk); | |
285 | ||
a8a97db9 MB |
286 | /** |
287 | * devm_clk_put - "free" a managed clock source | |
da3dae54 | 288 | * @dev: device used to acquire the clock |
a8a97db9 MB |
289 | * @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 | */ | |
297 | void devm_clk_put(struct device *dev, struct clk *clk); | |
1da177e4 LT |
298 | |
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 | * | |
d2d14a77 RK |
309 | * 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 | * | |
1da177e4 LT |
323 | * Returns rounded clock rate in Hz, or negative errno. |
324 | */ | |
325 | long clk_round_rate(struct clk *clk, unsigned long rate); | |
8b7730dd | 326 | |
1da177e4 LT |
327 | /** |
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 | */ | |
334 | int clk_set_rate(struct clk *clk, unsigned long rate); | |
8b7730dd | 335 | |
4e88f3de TR |
336 | /** |
337 | * 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 | */ | |
346 | bool clk_has_parent(struct clk *clk, struct clk *parent); | |
347 | ||
1c8e6004 TV |
348 | /** |
349 | * 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 | */ | |
356 | int 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 | */ | |
365 | int 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 | */ | |
374 | int clk_set_max_rate(struct clk *clk, unsigned long rate); | |
375 | ||
1da177e4 LT |
376 | /** |
377 | * 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 | */ | |
383 | int 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 | */ | |
392 | struct clk *clk_get_parent(struct clk *clk); | |
393 | ||
05fd8e73 SH |
394 | /** |
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 | */ | |
409 | struct clk *clk_get_sys(const char *dev_id, const char *con_id); | |
410 | ||
93abe8e4 VK |
411 | #else /* !CONFIG_HAVE_CLK */ |
412 | ||
413 | static inline struct clk *clk_get(struct device *dev, const char *id) | |
414 | { | |
415 | return NULL; | |
416 | } | |
417 | ||
418 | static inline struct clk *devm_clk_get(struct device *dev, const char *id) | |
419 | { | |
420 | return NULL; | |
421 | } | |
422 | ||
423 | static inline void clk_put(struct clk *clk) {} | |
424 | ||
425 | static inline void devm_clk_put(struct device *dev, struct clk *clk) {} | |
426 | ||
427 | static inline int clk_enable(struct clk *clk) | |
428 | { | |
429 | return 0; | |
430 | } | |
431 | ||
432 | static inline void clk_disable(struct clk *clk) {} | |
433 | ||
434 | static inline unsigned long clk_get_rate(struct clk *clk) | |
435 | { | |
436 | return 0; | |
437 | } | |
438 | ||
439 | static inline int clk_set_rate(struct clk *clk, unsigned long rate) | |
440 | { | |
441 | return 0; | |
442 | } | |
443 | ||
444 | static inline long clk_round_rate(struct clk *clk, unsigned long rate) | |
445 | { | |
446 | return 0; | |
447 | } | |
448 | ||
4e88f3de TR |
449 | static inline bool clk_has_parent(struct clk *clk, struct clk *parent) |
450 | { | |
451 | return true; | |
452 | } | |
453 | ||
93abe8e4 VK |
454 | static inline int clk_set_parent(struct clk *clk, struct clk *parent) |
455 | { | |
456 | return 0; | |
457 | } | |
458 | ||
459 | static 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. */ | |
467 | static 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. */ | |
482 | static inline void clk_disable_unprepare(struct clk *clk) | |
483 | { | |
484 | clk_disable(clk); | |
485 | clk_unprepare(clk); | |
486 | } | |
487 | ||
766e6a4e GL |
488 | struct device_node; |
489 | struct of_phandle_args; | |
490 | ||
137f8a72 | 491 | #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) |
766e6a4e GL |
492 | struct clk *of_clk_get(struct device_node *np, int index); |
493 | struct clk *of_clk_get_by_name(struct device_node *np, const char *name); | |
494 | struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec); | |
495 | #else | |
496 | static inline struct clk *of_clk_get(struct device_node *np, int index) | |
497 | { | |
9f1612d3 | 498 | return ERR_PTR(-ENOENT); |
766e6a4e GL |
499 | } |
500 | static inline struct clk *of_clk_get_by_name(struct device_node *np, | |
501 | const char *name) | |
502 | { | |
9f1612d3 | 503 | return ERR_PTR(-ENOENT); |
766e6a4e GL |
504 | } |
505 | #endif | |
506 | ||
1da177e4 | 507 | #endif |