~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/include/linux/clk.h

Version: ~ [ linux-5.4-rc7 ] ~ [ linux-5.3.10 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.83 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.153 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.200 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.200 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.76 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  *  linux/include/linux/clk.h
  3  *
  4  *  Copyright (C) 2004 ARM Limited.
  5  *  Written by Deep Blue Solutions Limited.
  6  *  Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
  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  */
 12 #ifndef __LINUX_CLK_H
 13 #define __LINUX_CLK_H
 14 
 15 #include <linux/err.h>
 16 #include <linux/kernel.h>
 17 #include <linux/notifier.h>
 18 
 19 struct device;
 20 
 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
 31  *     rate change.  Callbacks may either return NOTIFY_DONE or
 32  *     NOTIFY_STOP.
 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
 37  *     always return NOTIFY_DONE.
 38  *
 39  * POST_RATE_CHANGE - called after the clk rate change has successfully
 40  *     completed.  Callbacks must always return NOTIFY_DONE.
 41  *
 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  */
 58 struct 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  */
 75 struct clk_notifier_data {
 76         struct clk              *clk;
 77         unsigned long           old_rate;
 78         unsigned long           new_rate;
 79 };
 80 
 81 int clk_notifier_register(struct clk *clk, struct notifier_block *nb);
 82 
 83 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb);
 84 
 85 #endif
 86 
 87 /**
 88  * clk_prepare - prepare a clock source
 89  * @clk: clock source
 90  *
 91  * This prepares the clock source for use.
 92  *
 93  * Must not be called from within atomic context.
 94  */
 95 #ifdef CONFIG_HAVE_CLK_PREPARE
 96 int clk_prepare(struct clk *clk);
 97 #else
 98 static inline int clk_prepare(struct clk *clk)
 99 {
100         might_sleep();
101         return 0;
102 }
103 #endif
104 
105 /**
106  * clk_unprepare - undo preparation of a clock source
107  * @clk: clock source
108  *
109  * This undoes a previously prepared clock.  The caller must balance
110  * the number of prepare and unprepare calls.
111  *
112  * Must not be called from within atomic context.
113  */
114 #ifdef CONFIG_HAVE_CLK_PREPARE
115 void clk_unprepare(struct clk *clk);
116 #else
117 static inline void clk_unprepare(struct clk *clk)
118 {
119         might_sleep();
120 }
121 #endif
122 
123 #ifdef CONFIG_HAVE_CLK
124 /**
125  * clk_get - lookup and obtain a reference to a clock producer.
126  * @dev: device for clock "consumer"
127  * @id: clock consumer ID
128  *
129  * Returns a struct clk corresponding to the clock producer, or
130  * valid IS_ERR() condition containing errno.  The implementation
131  * uses @dev and @id to determine the clock consumer, and thereby
132  * the clock producer.  (IOW, @id may be identical strings, but
133  * clk_get may return different clock producers depending on @dev.)
134  *
135  * Drivers must assume that the clock source is not enabled.
136  *
137  * clk_get should not be called from within interrupt context.
138  */
139 struct clk *clk_get(struct device *dev, const char *id);
140 
141 /**
142  * devm_clk_get - lookup and obtain a managed reference to a clock producer.
143  * @dev: device for clock "consumer"
144  * @id: clock consumer ID
145  *
146  * Returns a struct clk corresponding to the clock producer, or
147  * 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.)
151  *
152  * Drivers must assume that the clock source is not enabled.
153  *
154  * devm_clk_get should not be called from within interrupt context.
155  *
156  * The clock will automatically be freed when the device is unbound
157  * from the bus.
158  */
159 struct clk *devm_clk_get(struct device *dev, const char *id);
160 
161 /**
162  * clk_enable - inform the system when the clock source should be running.
163  * @clk: clock source
164  *
165  * If the clock can not be enabled/disabled, this should return success.
166  *
167  * May be called from atomic contexts.
168  *
169  * Returns success (0) or negative errno.
170  */
171 int clk_enable(struct clk *clk);
172 
173 /**
174  * clk_disable - inform the system when the clock source is no longer required.
175  * @clk: clock source
176  *
177  * Inform the system that a clock source is no longer required by
178  * a driver and may be shut down.
179  *
180  * May be called from atomic contexts.
181  *
182  * Implementation detail: if the clock source is shared between
183  * multiple drivers, clk_enable() calls must be balanced by the
184  * same number of clk_disable() calls for the clock source to be
185  * disabled.
186  */
187 void clk_disable(struct clk *clk);
188 
189 /**
190  * clk_get_rate - obtain the current clock rate (in Hz) for a clock source.
191  *                This is only valid once the clock source has been enabled.
192  * @clk: clock source
193  */
194 unsigned long clk_get_rate(struct clk *clk);
195 
196 /**
197  * clk_put      - "free" the clock source
198  * @clk: clock source
199  *
200  * Note: drivers must ensure that all clk_enable calls made on this
201  * clock source are balanced by clk_disable calls prior to calling
202  * this function.
203  *
204  * clk_put should not be called from within interrupt context.
205  */
206 void clk_put(struct clk *clk);
207 
208 /**
209  * devm_clk_put - "free" a managed clock source
210  * @dev: device used to acuqire the clock
211  * @clk: clock source acquired with devm_clk_get()
212  *
213  * Note: drivers must ensure that all clk_enable calls made on this
214  * clock source are balanced by clk_disable calls prior to calling
215  * this function.
216  *
217  * clk_put should not be called from within interrupt context.
218  */
219 void devm_clk_put(struct device *dev, struct clk *clk);
220 
221 /*
222  * The remaining APIs are optional for machine class support.
223  */
224 
225 
226 /**
227  * clk_round_rate - adjust a rate to the exact rate a clock can provide
228  * @clk: clock source
229  * @rate: desired clock rate in Hz
230  *
231  * Returns rounded clock rate in Hz, or negative errno.
232  */
233 long clk_round_rate(struct clk *clk, unsigned long rate);
234 
235 /**
236  * clk_set_rate - set the clock rate for a clock source
237  * @clk: clock source
238  * @rate: desired clock rate in Hz
239  *
240  * Returns success (0) or negative errno.
241  */
242 int clk_set_rate(struct clk *clk, unsigned long rate);
243 
244 /**
245  * clk_set_parent - set the parent clock source for this clock
246  * @clk: clock source
247  * @parent: parent clock source
248  *
249  * Returns success (0) or negative errno.
250  */
251 int clk_set_parent(struct clk *clk, struct clk *parent);
252 
253 /**
254  * clk_get_parent - get the parent clock source for this clock
255  * @clk: clock source
256  *
257  * Returns struct clk corresponding to parent clock source, or
258  * valid IS_ERR() condition containing errno.
259  */
260 struct clk *clk_get_parent(struct clk *clk);
261 
262 /**
263  * clk_get_sys - get a clock based upon the device name
264  * @dev_id: device name
265  * @con_id: connection ID
266  *
267  * Returns a struct clk corresponding to the clock producer, or
268  * valid IS_ERR() condition containing errno.  The implementation
269  * uses @dev_id and @con_id to determine the clock consumer, and
270  * thereby the clock producer. In contrast to clk_get() this function
271  * takes the device name instead of the device itself for identification.
272  *
273  * Drivers must assume that the clock source is not enabled.
274  *
275  * clk_get_sys should not be called from within interrupt context.
276  */
277 struct clk *clk_get_sys(const char *dev_id, const char *con_id);
278 
279 #else /* !CONFIG_HAVE_CLK */
280 
281 static inline struct clk *clk_get(struct device *dev, const char *id)
282 {
283         return NULL;
284 }
285 
286 static inline struct clk *devm_clk_get(struct device *dev, const char *id)
287 {
288         return NULL;
289 }
290 
291 static inline void clk_put(struct clk *clk) {}
292 
293 static inline void devm_clk_put(struct device *dev, struct clk *clk) {}
294 
295 static inline int clk_enable(struct clk *clk)
296 {
297         return 0;
298 }
299 
300 static inline void clk_disable(struct clk *clk) {}
301 
302 static inline unsigned long clk_get_rate(struct clk *clk)
303 {
304         return 0;
305 }
306 
307 static inline int clk_set_rate(struct clk *clk, unsigned long rate)
308 {
309         return 0;
310 }
311 
312 static inline long clk_round_rate(struct clk *clk, unsigned long rate)
313 {
314         return 0;
315 }
316 
317 static inline int clk_set_parent(struct clk *clk, struct clk *parent)
318 {
319         return 0;
320 }
321 
322 static inline struct clk *clk_get_parent(struct clk *clk)
323 {
324         return NULL;
325 }
326 
327 #endif
328 
329 /* clk_prepare_enable helps cases using clk_enable in non-atomic context. */
330 static inline int clk_prepare_enable(struct clk *clk)
331 {
332         int ret;
333 
334         ret = clk_prepare(clk);
335         if (ret)
336                 return ret;
337         ret = clk_enable(clk);
338         if (ret)
339                 clk_unprepare(clk);
340 
341         return ret;
342 }
343 
344 /* clk_disable_unprepare helps cases using clk_disable in non-atomic context. */
345 static inline void clk_disable_unprepare(struct clk *clk)
346 {
347         clk_disable(clk);
348         clk_unprepare(clk);
349 }
350 
351 /**
352  * clk_add_alias - add a new clock alias
353  * @alias: name for clock alias
354  * @alias_dev_name: device name
355  * @id: platform specific clock name
356  * @dev: device
357  *
358  * Allows using generic clock names for drivers by adding a new alias.
359  * Assumes clkdev, see clkdev.h for more info.
360  */
361 int clk_add_alias(const char *alias, const char *alias_dev_name, char *id,
362                         struct device *dev);
363 
364 struct device_node;
365 struct of_phandle_args;
366 
367 #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
368 struct clk *of_clk_get(struct device_node *np, int index);
369 struct clk *of_clk_get_by_name(struct device_node *np, const char *name);
370 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec);
371 #else
372 static inline struct clk *of_clk_get(struct device_node *np, int index)
373 {
374         return ERR_PTR(-ENOENT);
375 }
376 static inline struct clk *of_clk_get_by_name(struct device_node *np,
377                                              const char *name)
378 {
379         return ERR_PTR(-ENOENT);
380 }
381 #endif
382 
383 #endif
384 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp