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

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

Version: ~ [ linux-5.9-rc6 ] ~ [ linux-5.8.10 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.66 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.146 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.198 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.236 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.236 ] ~ [ 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-3.16.85 ] ~ [ 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-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  * devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework
  3  *          for Non-CPU Devices.
  4  *
  5  * Copyright (C) 2011 Samsung Electronics
  6  *      MyungJoo Ham <myungjoo.ham@samsung.com>
  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 
 13 #ifndef __LINUX_DEVFREQ_H__
 14 #define __LINUX_DEVFREQ_H__
 15 
 16 #include <linux/device.h>
 17 #include <linux/notifier.h>
 18 #include <linux/pm_opp.h>
 19 
 20 #define DEVFREQ_NAME_LEN 16
 21 
 22 /* DEVFREQ notifier interface */
 23 #define DEVFREQ_TRANSITION_NOTIFIER     (0)
 24 
 25 /* Transition notifiers of DEVFREQ_TRANSITION_NOTIFIER */
 26 #define DEVFREQ_PRECHANGE               (0)
 27 #define DEVFREQ_POSTCHANGE              (1)
 28 
 29 struct devfreq;
 30 
 31 /**
 32  * struct devfreq_dev_status - Data given from devfreq user device to
 33  *                           governors. Represents the performance
 34  *                           statistics.
 35  * @total_time:         The total time represented by this instance of
 36  *                      devfreq_dev_status
 37  * @busy_time:          The time that the device was working among the
 38  *                      total_time.
 39  * @current_frequency:  The operating frequency.
 40  * @private_data:       An entry not specified by the devfreq framework.
 41  *                      A device and a specific governor may have their
 42  *                      own protocol with private_data. However, because
 43  *                      this is governor-specific, a governor using this
 44  *                      will be only compatible with devices aware of it.
 45  */
 46 struct devfreq_dev_status {
 47         /* both since the last measure */
 48         unsigned long total_time;
 49         unsigned long busy_time;
 50         unsigned long current_frequency;
 51         void *private_data;
 52 };
 53 
 54 /*
 55  * The resulting frequency should be at most this. (this bound is the
 56  * least upper bound; thus, the resulting freq should be lower or same)
 57  * If the flag is not set, the resulting frequency should be at most the
 58  * bound (greatest lower bound)
 59  */
 60 #define DEVFREQ_FLAG_LEAST_UPPER_BOUND          0x1
 61 
 62 /**
 63  * struct devfreq_dev_profile - Devfreq's user device profile
 64  * @initial_freq:       The operating frequency when devfreq_add_device() is
 65  *                      called.
 66  * @polling_ms:         The polling interval in ms. 0 disables polling.
 67  * @target:             The device should set its operating frequency at
 68  *                      freq or lowest-upper-than-freq value. If freq is
 69  *                      higher than any operable frequency, set maximum.
 70  *                      Before returning, target function should set
 71  *                      freq at the current frequency.
 72  *                      The "flags" parameter's possible values are
 73  *                      explained above with "DEVFREQ_FLAG_*" macros.
 74  * @get_dev_status:     The device should provide the current performance
 75  *                      status to devfreq. Governors are recommended not to
 76  *                      use this directly. Instead, governors are recommended
 77  *                      to use devfreq_update_stats() along with
 78  *                      devfreq.last_status.
 79  * @get_cur_freq:       The device should provide the current frequency
 80  *                      at which it is operating.
 81  * @exit:               An optional callback that is called when devfreq
 82  *                      is removing the devfreq object due to error or
 83  *                      from devfreq_remove_device() call. If the user
 84  *                      has registered devfreq->nb at a notifier-head,
 85  *                      this is the time to unregister it.
 86  * @freq_table: Optional list of frequencies to support statistics.
 87  * @max_state:  The size of freq_table.
 88  */
 89 struct devfreq_dev_profile {
 90         unsigned long initial_freq;
 91         unsigned int polling_ms;
 92 
 93         int (*target)(struct device *dev, unsigned long *freq, u32 flags);
 94         int (*get_dev_status)(struct device *dev,
 95                               struct devfreq_dev_status *stat);
 96         int (*get_cur_freq)(struct device *dev, unsigned long *freq);
 97         void (*exit)(struct device *dev);
 98 
 99         unsigned long *freq_table;
100         unsigned int max_state;
101 };
102 
103 /**
104  * struct devfreq_governor - Devfreq policy governor
105  * @node:               list node - contains registered devfreq governors
106  * @name:               Governor's name
107  * @get_target_freq:    Returns desired operating frequency for the device.
108  *                      Basically, get_target_freq will run
109  *                      devfreq_dev_profile.get_dev_status() to get the
110  *                      status of the device (load = busy_time / total_time).
111  *                      If no_central_polling is set, this callback is called
112  *                      only with update_devfreq() notified by OPP.
113  * @event_handler:      Callback for devfreq core framework to notify events
114  *                      to governors. Events include per device governor
115  *                      init and exit, opp changes out of devfreq, suspend
116  *                      and resume of per device devfreq during device idle.
117  *
118  * Note that the callbacks are called with devfreq->lock locked by devfreq.
119  */
120 struct devfreq_governor {
121         struct list_head node;
122 
123         const char name[DEVFREQ_NAME_LEN];
124         int (*get_target_freq)(struct devfreq *this, unsigned long *freq);
125         int (*event_handler)(struct devfreq *devfreq,
126                                 unsigned int event, void *data);
127 };
128 
129 /**
130  * struct devfreq - Device devfreq structure
131  * @node:       list node - contains the devices with devfreq that have been
132  *              registered.
133  * @lock:       a mutex to protect accessing devfreq.
134  * @dev:        device registered by devfreq class. dev.parent is the device
135  *              using devfreq.
136  * @profile:    device-specific devfreq profile
137  * @governor:   method how to choose frequency based on the usage.
138  * @governor_name:      devfreq governor name for use with this devfreq
139  * @nb:         notifier block used to notify devfreq object that it should
140  *              reevaluate operable frequencies. Devfreq users may use
141  *              devfreq.nb to the corresponding register notifier call chain.
142  * @work:       delayed work for load monitoring.
143  * @previous_freq:      previously configured frequency value.
144  * @data:       Private data of the governor. The devfreq framework does not
145  *              touch this.
146  * @min_freq:   Limit minimum frequency requested by user (0: none)
147  * @max_freq:   Limit maximum frequency requested by user (0: none)
148  * @stop_polling:        devfreq polling status of a device.
149  * @total_trans:        Number of devfreq transitions
150  * @trans_table:        Statistics of devfreq transitions
151  * @time_in_state:      Statistics of devfreq states
152  * @last_stat_updated:  The last time stat updated
153  * @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier
154  *
155  * This structure stores the devfreq information for a give device.
156  *
157  * Note that when a governor accesses entries in struct devfreq in its
158  * functions except for the context of callbacks defined in struct
159  * devfreq_governor, the governor should protect its access with the
160  * struct mutex lock in struct devfreq. A governor may use this mutex
161  * to protect its own private data in void *data as well.
162  */
163 struct devfreq {
164         struct list_head node;
165 
166         struct mutex lock;
167         struct device dev;
168         struct devfreq_dev_profile *profile;
169         const struct devfreq_governor *governor;
170         char governor_name[DEVFREQ_NAME_LEN];
171         struct notifier_block nb;
172         struct delayed_work work;
173 
174         unsigned long previous_freq;
175         struct devfreq_dev_status last_status;
176 
177         void *data; /* private data for governors */
178 
179         unsigned long min_freq;
180         unsigned long max_freq;
181         bool stop_polling;
182 
183         /* information for device frequency transition */
184         unsigned int total_trans;
185         unsigned int *trans_table;
186         unsigned long *time_in_state;
187         unsigned long last_stat_updated;
188 
189         struct srcu_notifier_head transition_notifier_list;
190 };
191 
192 struct devfreq_freqs {
193         unsigned long old;
194         unsigned long new;
195 };
196 
197 #if defined(CONFIG_PM_DEVFREQ)
198 extern struct devfreq *devfreq_add_device(struct device *dev,
199                                   struct devfreq_dev_profile *profile,
200                                   const char *governor_name,
201                                   void *data);
202 extern int devfreq_remove_device(struct devfreq *devfreq);
203 extern struct devfreq *devm_devfreq_add_device(struct device *dev,
204                                   struct devfreq_dev_profile *profile,
205                                   const char *governor_name,
206                                   void *data);
207 extern void devm_devfreq_remove_device(struct device *dev,
208                                   struct devfreq *devfreq);
209 
210 /* Supposed to be called by PM callbacks */
211 extern int devfreq_suspend_device(struct devfreq *devfreq);
212 extern int devfreq_resume_device(struct devfreq *devfreq);
213 
214 /* Helper functions for devfreq user device driver with OPP. */
215 extern struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
216                                            unsigned long *freq, u32 flags);
217 extern int devfreq_register_opp_notifier(struct device *dev,
218                                          struct devfreq *devfreq);
219 extern int devfreq_unregister_opp_notifier(struct device *dev,
220                                            struct devfreq *devfreq);
221 extern int devm_devfreq_register_opp_notifier(struct device *dev,
222                                               struct devfreq *devfreq);
223 extern void devm_devfreq_unregister_opp_notifier(struct device *dev,
224                                                 struct devfreq *devfreq);
225 extern int devfreq_register_notifier(struct devfreq *devfreq,
226                                         struct notifier_block *nb,
227                                         unsigned int list);
228 extern int devfreq_unregister_notifier(struct devfreq *devfreq,
229                                         struct notifier_block *nb,
230                                         unsigned int list);
231 extern int devm_devfreq_register_notifier(struct device *dev,
232                                 struct devfreq *devfreq,
233                                 struct notifier_block *nb,
234                                 unsigned int list);
235 extern void devm_devfreq_unregister_notifier(struct device *dev,
236                                 struct devfreq *devfreq,
237                                 struct notifier_block *nb,
238                                 unsigned int list);
239 extern struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
240                                                 int index);
241 
242 /**
243  * devfreq_update_stats() - update the last_status pointer in struct devfreq
244  * @df:         the devfreq instance whose status needs updating
245  *
246  *  Governors are recommended to use this function along with last_status,
247  * which allows other entities to reuse the last_status without affecting
248  * the values fetched later by governors.
249  */
250 static inline int devfreq_update_stats(struct devfreq *df)
251 {
252         return df->profile->get_dev_status(df->dev.parent, &df->last_status);
253 }
254 
255 #if IS_ENABLED(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND)
256 /**
257  * struct devfreq_simple_ondemand_data - void *data fed to struct devfreq
258  *      and devfreq_add_device
259  * @upthreshold:        If the load is over this value, the frequency jumps.
260  *                      Specify 0 to use the default. Valid value = 0 to 100.
261  * @downdifferential:   If the load is under upthreshold - downdifferential,
262  *                      the governor may consider slowing the frequency down.
263  *                      Specify 0 to use the default. Valid value = 0 to 100.
264  *                      downdifferential < upthreshold must hold.
265  *
266  * If the fed devfreq_simple_ondemand_data pointer is NULL to the governor,
267  * the governor uses the default values.
268  */
269 struct devfreq_simple_ondemand_data {
270         unsigned int upthreshold;
271         unsigned int downdifferential;
272 };
273 #endif
274 
275 #if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
276 /**
277  * struct devfreq_passive_data - void *data fed to struct devfreq
278  *      and devfreq_add_device
279  * @parent:     the devfreq instance of parent device.
280  * @get_target_freq:    Optional callback, Returns desired operating frequency
281  *                      for the device using passive governor. That is called
282  *                      when passive governor should decide the next frequency
283  *                      by using the new frequency of parent devfreq device
284  *                      using governors except for passive governor.
285  *                      If the devfreq device has the specific method to decide
286  *                      the next frequency, should use this callback.
287  * @this:       the devfreq instance of own device.
288  * @nb:         the notifier block for DEVFREQ_TRANSITION_NOTIFIER list
289  *
290  * The devfreq_passive_data have to set the devfreq instance of parent
291  * device with governors except for the passive governor. But, don't need to
292  * initialize the 'this' and 'nb' field because the devfreq core will handle
293  * them.
294  */
295 struct devfreq_passive_data {
296         /* Should set the devfreq instance of parent device */
297         struct devfreq *parent;
298 
299         /* Optional callback to decide the next frequency of passvice device */
300         int (*get_target_freq)(struct devfreq *this, unsigned long *freq);
301 
302         /* For passive governor's internal use. Don't need to set them */
303         struct devfreq *this;
304         struct notifier_block nb;
305 };
306 #endif
307 
308 #else /* !CONFIG_PM_DEVFREQ */
309 static inline struct devfreq *devfreq_add_device(struct device *dev,
310                                           struct devfreq_dev_profile *profile,
311                                           const char *governor_name,
312                                           void *data)
313 {
314         return ERR_PTR(-ENOSYS);
315 }
316 
317 static inline int devfreq_remove_device(struct devfreq *devfreq)
318 {
319         return 0;
320 }
321 
322 static inline struct devfreq *devm_devfreq_add_device(struct device *dev,
323                                         struct devfreq_dev_profile *profile,
324                                         const char *governor_name,
325                                         void *data)
326 {
327         return ERR_PTR(-ENOSYS);
328 }
329 
330 static inline void devm_devfreq_remove_device(struct device *dev,
331                                         struct devfreq *devfreq)
332 {
333 }
334 
335 static inline int devfreq_suspend_device(struct devfreq *devfreq)
336 {
337         return 0;
338 }
339 
340 static inline int devfreq_resume_device(struct devfreq *devfreq)
341 {
342         return 0;
343 }
344 
345 static inline struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
346                                            unsigned long *freq, u32 flags)
347 {
348         return ERR_PTR(-EINVAL);
349 }
350 
351 static inline int devfreq_register_opp_notifier(struct device *dev,
352                                          struct devfreq *devfreq)
353 {
354         return -EINVAL;
355 }
356 
357 static inline int devfreq_unregister_opp_notifier(struct device *dev,
358                                            struct devfreq *devfreq)
359 {
360         return -EINVAL;
361 }
362 
363 static inline int devm_devfreq_register_opp_notifier(struct device *dev,
364                                                      struct devfreq *devfreq)
365 {
366         return -EINVAL;
367 }
368 
369 static inline void devm_devfreq_unregister_opp_notifier(struct device *dev,
370                                                         struct devfreq *devfreq)
371 {
372 }
373 
374 static inline int devfreq_register_notifier(struct devfreq *devfreq,
375                                         struct notifier_block *nb,
376                                         unsigned int list)
377 {
378         return 0;
379 }
380 
381 static inline int devfreq_unregister_notifier(struct devfreq *devfreq,
382                                         struct notifier_block *nb,
383                                         unsigned int list)
384 {
385         return 0;
386 }
387 
388 static inline int devm_devfreq_register_notifier(struct device *dev,
389                                 struct devfreq *devfreq,
390                                 struct notifier_block *nb,
391                                 unsigned int list)
392 {
393         return 0;
394 }
395 
396 static inline void devm_devfreq_unregister_notifier(struct device *dev,
397                                 struct devfreq *devfreq,
398                                 struct notifier_block *nb,
399                                 unsigned int list)
400 {
401 }
402 
403 static inline struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
404                                                         int index)
405 {
406         return ERR_PTR(-ENODEV);
407 }
408 
409 static inline int devfreq_update_stats(struct devfreq *df)
410 {
411         return -EINVAL;
412 }
413 #endif /* CONFIG_PM_DEVFREQ */
414 
415 #endif /* __LINUX_DEVFREQ_H__ */
416 

~ [ 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