1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework
4 * for Non-CPU Devices.
5 *
6 * Copyright (C) 2011 Samsung Electronics
7 * MyungJoo Ham <myungjoo.ham@samsung.com>
8 */
9
10 #ifndef __LINUX_DEVFREQ_H__
11 #define __LINUX_DEVFREQ_H__
12
13 #include <linux/device.h>
14 #include <linux/notifier.h>
15 #include <linux/pm_opp.h>
16 #include <linux/pm_qos.h>
17
18 /* DEVFREQ governor name */
19 #define DEVFREQ_GOV_SIMPLE_ONDEMAND "simple_ondemand"
20 #define DEVFREQ_GOV_PERFORMANCE "performance"
21 #define DEVFREQ_GOV_POWERSAVE "powersave"
22 #define DEVFREQ_GOV_USERSPACE "userspace"
23 #define DEVFREQ_GOV_PASSIVE "passive"
24
25 /* DEVFREQ notifier interface */
26 #define DEVFREQ_TRANSITION_NOTIFIER (0)
27
28 /* Transition notifiers of DEVFREQ_TRANSITION_NOTIFIER */
29 #define DEVFREQ_PRECHANGE (0)
30 #define DEVFREQ_POSTCHANGE (1)
31
32 /* DEVFREQ work timers */
33 enum devfreq_timer {
34 DEVFREQ_TIMER_DEFERRABLE = 0,
35 DEVFREQ_TIMER_DELAYED,
36 DEVFREQ_TIMER_NUM,
37 };
38
39 struct devfreq;
40 struct devfreq_governor;
41 struct devfreq_cpu_data;
42 struct thermal_cooling_device;
43
44 /**
45 * struct devfreq_dev_status - Data given from devfreq user device to
46 * governors. Represents the performance
47 * statistics.
48 * @total_time: The total time represented by this instance of
49 * devfreq_dev_status
50 * @busy_time: The time that the device was working among the
51 * total_time.
52 * @current_frequency: The operating frequency.
53 * @private_data: An entry not specified by the devfreq framework.
54 * A device and a specific governor may have their
55 * own protocol with private_data. However, because
56 * this is governor-specific, a governor using this
57 * will be only compatible with devices aware of it.
58 */
59 struct devfreq_dev_status {
60 /* both since the last measure */
61 unsigned long total_time;
62 unsigned long busy_time;
63 unsigned long current_frequency;
64 void *private_data;
65 };
66
67 /*
68 * The resulting frequency should be at most this. (this bound is the
69 * least upper bound; thus, the resulting freq should be lower or same)
70 * If the flag is not set, the resulting frequency should be at most the
71 * bound (greatest lower bound)
72 */
73 #define DEVFREQ_FLAG_LEAST_UPPER_BOUND 0x1
74
75 /**
76 * struct devfreq_dev_profile - Devfreq's user device profile
77 * @initial_freq: The operating frequency when devfreq_add_device() is
78 * called.
79 * @polling_ms: The polling interval in ms. 0 disables polling.
80 * @timer: Timer type is either deferrable or delayed timer.
81 * @target: The device should set its operating frequency at
82 * freq or lowest-upper-than-freq value. If freq is
83 * higher than any operable frequency, set maximum.
84 * Before returning, target function should set
85 * freq at the current frequency.
86 * The "flags" parameter's possible values are
87 * explained above with "DEVFREQ_FLAG_*" macros.
88 * @get_dev_status: The device should provide the current performance
89 * status to devfreq. Governors are recommended not to
90 * use this directly. Instead, governors are recommended
91 * to use devfreq_update_stats() along with
92 * devfreq.last_status.
93 * @get_cur_freq: The device should provide the current frequency
94 * at which it is operating.
95 * @exit: An optional callback that is called when devfreq
96 * is removing the devfreq object due to error or
97 * from devfreq_remove_device() call. If the user
98 * has registered devfreq->nb at a notifier-head,
99 * this is the time to unregister it.
100 * @freq_table: Optional list of frequencies to support statistics
101 * and freq_table must be generated in ascending order.
102 * @max_state: The size of freq_table.
103 *
104 * @is_cooling_device: A self-explanatory boolean giving the device a
105 * cooling effect property.
106 */
107 struct devfreq_dev_profile {
108 unsigned long initial_freq;
109 unsigned int polling_ms;
110 enum devfreq_timer timer;
111 bool is_cooling_device;
112
113 int (*target)(struct device *dev, unsigned long *freq, u32 flags);
114 int (*get_dev_status)(struct device *dev,
115 struct devfreq_dev_status *stat);
116 int (*get_cur_freq)(struct device *dev, unsigned long *freq);
117 void (*exit)(struct device *dev);
118
119 unsigned long *freq_table;
120 unsigned int max_state;
121 };
122
123 /**
124 * struct devfreq_stats - Statistics of devfreq device behavior
125 * @total_trans: Number of devfreq transitions.
126 * @trans_table: Statistics of devfreq transitions.
127 * @time_in_state: Statistics of devfreq states.
128 * @last_update: The last time stats were updated.
129 */
130 struct devfreq_stats {
131 unsigned int total_trans;
132 unsigned int *trans_table;
133 u64 *time_in_state;
134 u64 last_update;
135 };
136
137 /**
138 * struct devfreq - Device devfreq structure
139 * @node: list node - contains the devices with devfreq that have been
140 * registered.
141 * @lock: a mutex to protect accessing devfreq.
142 * @dev: device registered by devfreq class. dev.parent is the device
143 * using devfreq.
144 * @profile: device-specific devfreq profile
145 * @governor: method how to choose frequency based on the usage.
146 * @opp_table: Reference to OPP table of dev.parent, if one exists.
147 * @nb: notifier block used to notify devfreq object that it should
148 * reevaluate operable frequencies. Devfreq users may use
149 * devfreq.nb to the corresponding register notifier call chain.
150 * @work: delayed work for load monitoring.
151 * @freq_table: current frequency table used by the devfreq driver.
152 * @max_state: count of entry present in the frequency table.
153 * @previous_freq: previously configured frequency value.
154 * @last_status: devfreq user device info, performance statistics
155 * @data: devfreq driver pass to governors, governor should not change it.
156 * @governor_data: private data for governors, devfreq core doesn't touch it.
157 * @user_min_freq_req: PM QoS minimum frequency request from user (via sysfs)
158 * @user_max_freq_req: PM QoS maximum frequency request from user (via sysfs)
159 * @scaling_min_freq: Limit minimum frequency requested by OPP interface
160 * @scaling_max_freq: Limit maximum frequency requested by OPP interface
161 * @stop_polling: devfreq polling status of a device.
162 * @suspend_freq: frequency of a device set during suspend phase.
163 * @resume_freq: frequency of a device set in resume phase.
164 * @suspend_count: suspend requests counter for a device.
165 * @stats: Statistics of devfreq device behavior
166 * @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier
167 * @cdev: Cooling device pointer if the devfreq has cooling property
168 * @nb_min: Notifier block for DEV_PM_QOS_MIN_FREQUENCY
169 * @nb_max: Notifier block for DEV_PM_QOS_MAX_FREQUENCY
170 *
171 * This structure stores the devfreq information for a given device.
172 *
173 * Note that when a governor accesses entries in struct devfreq in its
174 * functions except for the context of callbacks defined in struct
175 * devfreq_governor, the governor should protect its access with the
176 * struct mutex lock in struct devfreq. A governor may use this mutex
177 * to protect its own private data in ``void *data`` as well.
178 */
179 struct devfreq {
180 struct list_head node;
181
182 struct mutex lock;
183 struct device dev;
184 struct devfreq_dev_profile *profile;
185 const struct devfreq_governor *governor;
186 struct opp_table *opp_table;
187 struct notifier_block nb;
188 struct delayed_work work;
189
190 unsigned long *freq_table;
191 unsigned int max_state;
192
193 unsigned long previous_freq;
194 struct devfreq_dev_status last_status;
195
196 void *data;
197 void *governor_data;
198
199 struct dev_pm_qos_request user_min_freq_req;
200 struct dev_pm_qos_request user_max_freq_req;
201 unsigned long scaling_min_freq;
202 unsigned long scaling_max_freq;
203 bool stop_polling;
204
205 unsigned long suspend_freq;
206 unsigned long resume_freq;
207 atomic_t suspend_count;
208
209 /* information for device frequency transitions */
210 struct devfreq_stats stats;
211
212 struct srcu_notifier_head transition_notifier_list;
213
214 /* Pointer to the cooling device if used for thermal mitigation */
215 struct thermal_cooling_device *cdev;
216
217 struct notifier_block nb_min;
218 struct notifier_block nb_max;
219 };
220
221 struct devfreq_freqs {
222 unsigned long old;
223 unsigned long new;
224 };
225
226 #if defined(CONFIG_PM_DEVFREQ)
227 struct devfreq *devfreq_add_device(struct device *dev,
228 struct devfreq_dev_profile *profile,
229 const char *governor_name,
230 void *data);
231 int devfreq_remove_device(struct devfreq *devfreq);
232 struct devfreq *devm_devfreq_add_device(struct device *dev,
233 struct devfreq_dev_profile *profile,
234 const char *governor_name,
235 void *data);
236 void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq);
237
238 /* Supposed to be called by PM callbacks */
239 int devfreq_suspend_device(struct devfreq *devfreq);
240 int devfreq_resume_device(struct devfreq *devfreq);
241
242 void devfreq_suspend(void);
243 void devfreq_resume(void);
244
245 /* update_devfreq() - Reevaluate the device and configure frequency */
246 int update_devfreq(struct devfreq *devfreq);
247
248 /* Helper functions for devfreq user device driver with OPP. */
249 struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
250 unsigned long *freq, u32 flags);
251 int devfreq_register_opp_notifier(struct device *dev,
252 struct devfreq *devfreq);
253 int devfreq_unregister_opp_notifier(struct device *dev,
254 struct devfreq *devfreq);
255 int devm_devfreq_register_opp_notifier(struct device *dev,
256 struct devfreq *devfreq);
257 void devm_devfreq_unregister_opp_notifier(struct device *dev,
258 struct devfreq *devfreq);
259 int devfreq_register_notifier(struct devfreq *devfreq,
260 struct notifier_block *nb,
261 unsigned int list);
262 int devfreq_unregister_notifier(struct devfreq *devfreq,
263 struct notifier_block *nb,
264 unsigned int list);
265 int devm_devfreq_register_notifier(struct device *dev,
266 struct devfreq *devfreq,
267 struct notifier_block *nb,
268 unsigned int list);
269 void devm_devfreq_unregister_notifier(struct device *dev,
270 struct devfreq *devfreq,
271 struct notifier_block *nb,
272 unsigned int list);
273 struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node);
274 struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
275 const char *phandle_name, int index);
276
277 #if IS_ENABLED(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND)
278 /**
279 * struct devfreq_simple_ondemand_data - ``void *data`` fed to struct devfreq
280 * and devfreq_add_device
281 * @upthreshold: If the load is over this value, the frequency jumps.
282 * Specify 0 to use the default. Valid value = 0 to 100.
283 * @downdifferential: If the load is under upthreshold - downdifferential,
284 * the governor may consider slowing the frequency down.
285 * Specify 0 to use the default. Valid value = 0 to 100.
286 * downdifferential < upthreshold must hold.
287 *
288 * If the fed devfreq_simple_ondemand_data pointer is NULL to the governor,
289 * the governor uses the default values.
290 */
291 struct devfreq_simple_ondemand_data {
292 unsigned int upthreshold;
293 unsigned int downdifferential;
294 };
295 #endif
296
297 #if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
298 enum devfreq_parent_dev_type {
299 DEVFREQ_PARENT_DEV,
300 CPUFREQ_PARENT_DEV,
301 };
302
303 /**
304 * struct devfreq_passive_data - ``void *data`` fed to struct devfreq
305 * and devfreq_add_device
306 * @parent: the devfreq instance of parent device.
307 * @get_target_freq: Optional callback, Returns desired operating frequency
308 * for the device using passive governor. That is called
309 * when passive governor should decide the next frequency
310 * by using the new frequency of parent devfreq device
311 * using governors except for passive governor.
312 * If the devfreq device has the specific method to decide
313 * the next frequency, should use this callback.
314 * @parent_type: the parent type of the device.
315 * @this: the devfreq instance of own device.
316 * @nb: the notifier block for DEVFREQ_TRANSITION_NOTIFIER or
317 * CPUFREQ_TRANSITION_NOTIFIER list.
318 * @cpu_data_list: the list of cpu frequency data for all cpufreq_policy.
319 *
320 * The devfreq_passive_data have to set the devfreq instance of parent
321 * device with governors except for the passive governor. But, don't need to
322 * initialize the 'this' and 'nb' field because the devfreq core will handle
323 * them.
324 */
325 struct devfreq_passive_data {
326 /* Should set the devfreq instance of parent device */
327 struct devfreq *parent;
328
329 /* Optional callback to decide the next frequency of passvice device */
330 int (*get_target_freq)(struct devfreq *this, unsigned long *freq);
331
332 /* Should set the type of parent device */
333 enum devfreq_parent_dev_type parent_type;
334
335 /* For passive governor's internal use. Don't need to set them */
336 struct devfreq *this;
337 struct notifier_block nb;
338 struct list_head cpu_data_list;
339 };
340 #endif
341
342 #else /* !CONFIG_PM_DEVFREQ */
devfreq_add_device(struct device * dev,struct devfreq_dev_profile * profile,const char * governor_name,void * data)343 static inline struct devfreq *devfreq_add_device(struct device *dev,
344 struct devfreq_dev_profile *profile,
345 const char *governor_name,
346 void *data)
347 {
348 return ERR_PTR(-ENOSYS);
349 }
350
devfreq_remove_device(struct devfreq * devfreq)351 static inline int devfreq_remove_device(struct devfreq *devfreq)
352 {
353 return 0;
354 }
355
devm_devfreq_add_device(struct device * dev,struct devfreq_dev_profile * profile,const char * governor_name,void * data)356 static inline struct devfreq *devm_devfreq_add_device(struct device *dev,
357 struct devfreq_dev_profile *profile,
358 const char *governor_name,
359 void *data)
360 {
361 return ERR_PTR(-ENOSYS);
362 }
363
devm_devfreq_remove_device(struct device * dev,struct devfreq * devfreq)364 static inline void devm_devfreq_remove_device(struct device *dev,
365 struct devfreq *devfreq)
366 {
367 }
368
devfreq_suspend_device(struct devfreq * devfreq)369 static inline int devfreq_suspend_device(struct devfreq *devfreq)
370 {
371 return 0;
372 }
373
devfreq_resume_device(struct devfreq * devfreq)374 static inline int devfreq_resume_device(struct devfreq *devfreq)
375 {
376 return 0;
377 }
378
devfreq_suspend(void)379 static inline void devfreq_suspend(void) {}
devfreq_resume(void)380 static inline void devfreq_resume(void) {}
381
devfreq_recommended_opp(struct device * dev,unsigned long * freq,u32 flags)382 static inline struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
383 unsigned long *freq, u32 flags)
384 {
385 return ERR_PTR(-EINVAL);
386 }
387
devfreq_register_opp_notifier(struct device * dev,struct devfreq * devfreq)388 static inline int devfreq_register_opp_notifier(struct device *dev,
389 struct devfreq *devfreq)
390 {
391 return -EINVAL;
392 }
393
devfreq_unregister_opp_notifier(struct device * dev,struct devfreq * devfreq)394 static inline int devfreq_unregister_opp_notifier(struct device *dev,
395 struct devfreq *devfreq)
396 {
397 return -EINVAL;
398 }
399
devm_devfreq_register_opp_notifier(struct device * dev,struct devfreq * devfreq)400 static inline int devm_devfreq_register_opp_notifier(struct device *dev,
401 struct devfreq *devfreq)
402 {
403 return -EINVAL;
404 }
405
devm_devfreq_unregister_opp_notifier(struct device * dev,struct devfreq * devfreq)406 static inline void devm_devfreq_unregister_opp_notifier(struct device *dev,
407 struct devfreq *devfreq)
408 {
409 }
410
devfreq_register_notifier(struct devfreq * devfreq,struct notifier_block * nb,unsigned int list)411 static inline int devfreq_register_notifier(struct devfreq *devfreq,
412 struct notifier_block *nb,
413 unsigned int list)
414 {
415 return 0;
416 }
417
devfreq_unregister_notifier(struct devfreq * devfreq,struct notifier_block * nb,unsigned int list)418 static inline int devfreq_unregister_notifier(struct devfreq *devfreq,
419 struct notifier_block *nb,
420 unsigned int list)
421 {
422 return 0;
423 }
424
devm_devfreq_register_notifier(struct device * dev,struct devfreq * devfreq,struct notifier_block * nb,unsigned int list)425 static inline int devm_devfreq_register_notifier(struct device *dev,
426 struct devfreq *devfreq,
427 struct notifier_block *nb,
428 unsigned int list)
429 {
430 return 0;
431 }
432
devm_devfreq_unregister_notifier(struct device * dev,struct devfreq * devfreq,struct notifier_block * nb,unsigned int list)433 static inline void devm_devfreq_unregister_notifier(struct device *dev,
434 struct devfreq *devfreq,
435 struct notifier_block *nb,
436 unsigned int list)
437 {
438 }
439
devfreq_get_devfreq_by_node(struct device_node * node)440 static inline struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node)
441 {
442 return ERR_PTR(-ENODEV);
443 }
444
devfreq_get_devfreq_by_phandle(struct device * dev,const char * phandle_name,int index)445 static inline struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
446 const char *phandle_name, int index)
447 {
448 return ERR_PTR(-ENODEV);
449 }
450
devfreq_update_stats(struct devfreq * df)451 static inline int devfreq_update_stats(struct devfreq *df)
452 {
453 return -EINVAL;
454 }
455 #endif /* CONFIG_PM_DEVFREQ */
456
457 #endif /* __LINUX_DEVFREQ_H__ */
458