blob: 0dd91148165e4e7df78beb5582b89910c1615f26 [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
81int clk_notifier_register(struct clk *clk, struct notifier_block *nb);
82
83int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb);
84
Boris BREZILLON5279fc42013-12-21 10:34:47 +010085/**
86 * clk_get_accuracy - obtain the clock accuracy in ppb (parts per billion)
87 * for a clock source.
88 * @clk: clock source
89 *
90 * This gets the clock source accuracy expressed in ppb.
91 * A perfect clock returns 0.
92 */
93long clk_get_accuracy(struct clk *clk);
94
95#else
96
97static inline long clk_get_accuracy(struct clk *clk)
98{
99 return -ENOTSUPP;
100}
101
Mark Brown7e87aed2012-04-01 15:31:23 +0100102#endif
Mike Turquetteb24764902012-03-15 23:11:19 -0700103
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104/**
Viresh Kumar93abe8e2012-07-30 14:39:27 -0700105 * clk_prepare - prepare a clock source
106 * @clk: clock source
107 *
108 * This prepares the clock source for use.
109 *
110 * Must not be called from within atomic context.
111 */
112#ifdef CONFIG_HAVE_CLK_PREPARE
113int clk_prepare(struct clk *clk);
114#else
115static inline int clk_prepare(struct clk *clk)
116{
117 might_sleep();
118 return 0;
119}
120#endif
121
122/**
123 * clk_unprepare - undo preparation of a clock source
124 * @clk: clock source
125 *
126 * This undoes a previously prepared clock. The caller must balance
127 * the number of prepare and unprepare calls.
128 *
129 * Must not be called from within atomic context.
130 */
131#ifdef CONFIG_HAVE_CLK_PREPARE
132void clk_unprepare(struct clk *clk);
133#else
134static inline void clk_unprepare(struct clk *clk)
135{
136 might_sleep();
137}
138#endif
139
140#ifdef CONFIG_HAVE_CLK
141/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 * clk_get - lookup and obtain a reference to a clock producer.
143 * @dev: device for clock "consumer"
Jan-Simon Möllera58b3a42012-07-23 20:48:56 +0200144 * @id: clock consumer ID
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 *
146 * Returns a struct clk corresponding to the clock producer, or
Russell Kingea3f4ea2005-04-27 18:19:55 +0100147 * valid IS_ERR() condition containing errno. The implementation
148 * uses @dev and @id to determine the clock consumer, and thereby
149 * the clock producer. (IOW, @id may be identical strings, but
150 * clk_get may return different clock producers depending on @dev.)
Russell Kingf47fc0a2006-01-03 18:34:20 +0000151 *
152 * Drivers must assume that the clock source is not enabled.
Alex Raimondif7ad1602008-10-15 22:02:03 -0700153 *
154 * clk_get should not be called from within interrupt context.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 */
156struct clk *clk_get(struct device *dev, const char *id);
157
158/**
Mark Browna8a97db2012-04-05 11:42:09 +0100159 * devm_clk_get - lookup and obtain a managed reference to a clock producer.
160 * @dev: device for clock "consumer"
Jan-Simon Möllera58b3a42012-07-23 20:48:56 +0200161 * @id: clock consumer ID
Mark Browna8a97db2012-04-05 11:42:09 +0100162 *
163 * Returns a struct clk corresponding to the clock producer, or
164 * valid IS_ERR() condition containing errno. The implementation
165 * uses @dev and @id to determine the clock consumer, and thereby
166 * the clock producer. (IOW, @id may be identical strings, but
167 * clk_get may return different clock producers depending on @dev.)
168 *
169 * Drivers must assume that the clock source is not enabled.
170 *
171 * devm_clk_get should not be called from within interrupt context.
172 *
173 * The clock will automatically be freed when the device is unbound
174 * from the bus.
175 */
176struct clk *devm_clk_get(struct device *dev, const char *id);
177
178/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 * clk_enable - inform the system when the clock source should be running.
180 * @clk: clock source
181 *
182 * If the clock can not be enabled/disabled, this should return success.
183 *
Russell King40d3e0f2011-09-22 11:30:50 +0100184 * May be called from atomic contexts.
185 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 * Returns success (0) or negative errno.
187 */
188int clk_enable(struct clk *clk);
189
190/**
191 * clk_disable - inform the system when the clock source is no longer required.
192 * @clk: clock source
Russell Kingf47fc0a2006-01-03 18:34:20 +0000193 *
194 * Inform the system that a clock source is no longer required by
195 * a driver and may be shut down.
196 *
Russell King40d3e0f2011-09-22 11:30:50 +0100197 * May be called from atomic contexts.
198 *
Russell Kingf47fc0a2006-01-03 18:34:20 +0000199 * Implementation detail: if the clock source is shared between
200 * multiple drivers, clk_enable() calls must be balanced by the
201 * same number of clk_disable() calls for the clock source to be
202 * disabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 */
204void clk_disable(struct clk *clk);
205
206/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 * clk_get_rate - obtain the current clock rate (in Hz) for a clock source.
208 * This is only valid once the clock source has been enabled.
209 * @clk: clock source
210 */
211unsigned long clk_get_rate(struct clk *clk);
212
213/**
214 * clk_put - "free" the clock source
215 * @clk: clock source
Russell Kingf47fc0a2006-01-03 18:34:20 +0000216 *
217 * Note: drivers must ensure that all clk_enable calls made on this
218 * clock source are balanced by clk_disable calls prior to calling
219 * this function.
Alex Raimondif7ad1602008-10-15 22:02:03 -0700220 *
221 * clk_put should not be called from within interrupt context.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 */
223void clk_put(struct clk *clk);
224
Mark Browna8a97db2012-04-05 11:42:09 +0100225/**
226 * devm_clk_put - "free" a managed clock source
227 * @dev: device used to acuqire the clock
228 * @clk: clock source acquired with devm_clk_get()
229 *
230 * Note: drivers must ensure that all clk_enable calls made on this
231 * clock source are balanced by clk_disable calls prior to calling
232 * this function.
233 *
234 * clk_put should not be called from within interrupt context.
235 */
236void devm_clk_put(struct device *dev, struct clk *clk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237
238/*
239 * The remaining APIs are optional for machine class support.
240 */
241
242
243/**
244 * clk_round_rate - adjust a rate to the exact rate a clock can provide
245 * @clk: clock source
246 * @rate: desired clock rate in Hz
247 *
248 * Returns rounded clock rate in Hz, or negative errno.
249 */
250long clk_round_rate(struct clk *clk, unsigned long rate);
Rob Herring8b7730d2012-04-09 15:24:59 -0500251
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252/**
253 * clk_set_rate - set the clock rate for a clock source
254 * @clk: clock source
255 * @rate: desired clock rate in Hz
256 *
257 * Returns success (0) or negative errno.
258 */
259int clk_set_rate(struct clk *clk, unsigned long rate);
Rob Herring8b7730d2012-04-09 15:24:59 -0500260
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261/**
262 * clk_set_parent - set the parent clock source for this clock
263 * @clk: clock source
264 * @parent: parent clock source
265 *
266 * Returns success (0) or negative errno.
267 */
268int clk_set_parent(struct clk *clk, struct clk *parent);
269
270/**
271 * clk_get_parent - get the parent clock source for this clock
272 * @clk: clock source
273 *
274 * Returns struct clk corresponding to parent clock source, or
275 * valid IS_ERR() condition containing errno.
276 */
277struct clk *clk_get_parent(struct clk *clk);
278
Sascha Hauer05fd8e72009-03-07 12:55:49 +0100279/**
280 * clk_get_sys - get a clock based upon the device name
281 * @dev_id: device name
282 * @con_id: connection ID
283 *
284 * Returns a struct clk corresponding to the clock producer, or
285 * valid IS_ERR() condition containing errno. The implementation
286 * uses @dev_id and @con_id to determine the clock consumer, and
287 * thereby the clock producer. In contrast to clk_get() this function
288 * takes the device name instead of the device itself for identification.
289 *
290 * Drivers must assume that the clock source is not enabled.
291 *
292 * clk_get_sys should not be called from within interrupt context.
293 */
294struct clk *clk_get_sys(const char *dev_id, const char *con_id);
295
Viresh Kumar93abe8e2012-07-30 14:39:27 -0700296#else /* !CONFIG_HAVE_CLK */
297
298static inline struct clk *clk_get(struct device *dev, const char *id)
299{
300 return NULL;
301}
302
303static inline struct clk *devm_clk_get(struct device *dev, const char *id)
304{
305 return NULL;
306}
307
308static inline void clk_put(struct clk *clk) {}
309
310static inline void devm_clk_put(struct device *dev, struct clk *clk) {}
311
312static inline int clk_enable(struct clk *clk)
313{
314 return 0;
315}
316
317static inline void clk_disable(struct clk *clk) {}
318
319static inline unsigned long clk_get_rate(struct clk *clk)
320{
321 return 0;
322}
323
324static inline int clk_set_rate(struct clk *clk, unsigned long rate)
325{
326 return 0;
327}
328
329static inline long clk_round_rate(struct clk *clk, unsigned long rate)
330{
331 return 0;
332}
333
334static inline int clk_set_parent(struct clk *clk, struct clk *parent)
335{
336 return 0;
337}
338
339static inline struct clk *clk_get_parent(struct clk *clk)
340{
341 return NULL;
342}
343
344#endif
345
346/* clk_prepare_enable helps cases using clk_enable in non-atomic context. */
347static inline int clk_prepare_enable(struct clk *clk)
348{
349 int ret;
350
351 ret = clk_prepare(clk);
352 if (ret)
353 return ret;
354 ret = clk_enable(clk);
355 if (ret)
356 clk_unprepare(clk);
357
358 return ret;
359}
360
361/* clk_disable_unprepare helps cases using clk_disable in non-atomic context. */
362static inline void clk_disable_unprepare(struct clk *clk)
363{
364 clk_disable(clk);
365 clk_unprepare(clk);
366}
367
Tony Lindgrenc0683032009-06-03 17:43:14 +0100368/**
369 * clk_add_alias - add a new clock alias
370 * @alias: name for clock alias
371 * @alias_dev_name: device name
372 * @id: platform specific clock name
373 * @dev: device
374 *
375 * Allows using generic clock names for drivers by adding a new alias.
376 * Assumes clkdev, see clkdev.h for more info.
377 */
378int clk_add_alias(const char *alias, const char *alias_dev_name, char *id,
379 struct device *dev);
380
Grant Likely766e6a42012-04-09 14:50:06 -0500381struct device_node;
382struct of_phandle_args;
383
Rob Herring137f8a72012-07-18 11:52:23 +0800384#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
Grant Likely766e6a42012-04-09 14:50:06 -0500385struct clk *of_clk_get(struct device_node *np, int index);
386struct clk *of_clk_get_by_name(struct device_node *np, const char *name);
387struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec);
388#else
389static inline struct clk *of_clk_get(struct device_node *np, int index)
390{
Shawn Guo9f1612d2012-07-18 11:52:22 +0800391 return ERR_PTR(-ENOENT);
Grant Likely766e6a42012-04-09 14:50:06 -0500392}
393static inline struct clk *of_clk_get_by_name(struct device_node *np,
394 const char *name)
395{
Shawn Guo9f1612d2012-07-18 11:52:22 +0800396 return ERR_PTR(-ENOENT);
Grant Likely766e6a42012-04-09 14:50:06 -0500397}
398#endif
399
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400#endif