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 * @dev_groups: Optional device-specific sysfs attribute groups that to
107 * be attached to the devfreq device.
108 */
109 struct devfreq_dev_profile {
110 unsigned long initial_freq;
111 unsigned int polling_ms;
112 enum devfreq_timer timer;
113
114 int (*target)(struct device *dev, unsigned long *freq, u32 flags);
115 int (*get_dev_status)(struct device *dev,
116 struct devfreq_dev_status *stat);
117 int (*get_cur_freq)(struct device *dev, unsigned long *freq);
118 void (*exit)(struct device *dev);
119
120 unsigned long *freq_table;
121 unsigned int max_state;
122
123 bool is_cooling_device;
124
125 const struct attribute_group **dev_groups;
126 };
127
128 /**
129 * struct devfreq_stats - Statistics of devfreq device behavior
130 * @total_trans: Number of devfreq transitions.
131 * @trans_table: Statistics of devfreq transitions.
132 * @time_in_state: Statistics of devfreq states.
133 * @last_update: The last time stats were updated.
134 */
135 struct devfreq_stats {
136 unsigned int total_trans;
137 unsigned int *trans_table;
138 u64 *time_in_state;
139 u64 last_update;
140 };
141
142 /**
143 * struct devfreq - Device devfreq structure
144 * @node: list node - contains the devices with devfreq that have been
145 * registered.
146 * @lock: a mutex to protect accessing devfreq.
147 * @dev: device registered by devfreq class. dev.parent is the device
148 * using devfreq.
149 * @profile: device-specific devfreq profile
150 * @governor: method how to choose frequency based on the usage.
151 * @opp_table: Reference to OPP table of dev.parent, if one exists.
152 * @nb: notifier block used to notify devfreq object that it should
153 * reevaluate operable frequencies. Devfreq users may use
154 * devfreq.nb to the corresponding register notifier call chain.
155 * @work: delayed work for load monitoring.
156 * @freq_table: current frequency table used by the devfreq driver.
157 * @max_state: count of entry present in the frequency table.
158 * @previous_freq: previously configured frequency value.
159 * @last_status: devfreq user device info, performance statistics
160 * @data: devfreq driver pass to governors, governor should not change it.
161 * @governor_data: private data for governors, devfreq core doesn't touch it.
162 * @user_min_freq_req: PM QoS minimum frequency request from user (via sysfs)
163 * @user_max_freq_req: PM QoS maximum frequency request from user (via sysfs)
164 * @scaling_min_freq: Limit minimum frequency requested by OPP interface
165 * @scaling_max_freq: Limit maximum frequency requested by OPP interface
166 * @stop_polling: devfreq polling status of a device.
167 * @suspend_freq: frequency of a device set during suspend phase.
168 * @resume_freq: frequency of a device set in resume phase.
169 * @suspend_count: suspend requests counter for a device.
170 * @stats: Statistics of devfreq device behavior
171 * @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier
172 * @cdev: Cooling device pointer if the devfreq has cooling property
173 * @nb_min: Notifier block for DEV_PM_QOS_MIN_FREQUENCY
174 * @nb_max: Notifier block for DEV_PM_QOS_MAX_FREQUENCY
175 *
176 * This structure stores the devfreq information for a given device.
177 *
178 * Note that when a governor accesses entries in struct devfreq in its
179 * functions except for the context of callbacks defined in struct
180 * devfreq_governor, the governor should protect its access with the
181 * struct mutex lock in struct devfreq. A governor may use this mutex
182 * to protect its own private data in ``void *data`` as well.
183 */
184 struct devfreq {
185 struct list_head node;
186
187 struct mutex lock;
188 struct device dev;
189 struct devfreq_dev_profile *profile;
190 const struct devfreq_governor *governor;
191 struct opp_table *opp_table;
192 struct notifier_block nb;
193 struct delayed_work work;
194
195 unsigned long *freq_table;
196 unsigned int max_state;
197
198 unsigned long previous_freq;
199 struct devfreq_dev_status last_status;
200
201 void *data;
202 void *governor_data;
203
204 struct dev_pm_qos_request user_min_freq_req;
205 struct dev_pm_qos_request user_max_freq_req;
206 unsigned long scaling_min_freq;
207 unsigned long scaling_max_freq;
208 bool stop_polling;
209
210 unsigned long suspend_freq;
211 unsigned long resume_freq;
212 atomic_t suspend_count;
213
214 /* information for device frequency transitions */
215 struct devfreq_stats stats;
216
217 struct srcu_notifier_head transition_notifier_list;
218
219 /* Pointer to the cooling device if used for thermal mitigation */
220 struct thermal_cooling_device *cdev;
221
222 struct notifier_block nb_min;
223 struct notifier_block nb_max;
224 };
225
226 struct devfreq_freqs {
227 unsigned long old;
228 unsigned long new;
229 };
230
231 #if defined(CONFIG_PM_DEVFREQ)
232 struct devfreq *devfreq_add_device(struct device *dev,
233 struct devfreq_dev_profile *profile,
234 const char *governor_name,
235 void *data);
236 int devfreq_remove_device(struct devfreq *devfreq);
237 struct devfreq *devm_devfreq_add_device(struct device *dev,
238 struct devfreq_dev_profile *profile,
239 const char *governor_name,
240 void *data);
241 void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq);
242
243 /* Supposed to be called by PM callbacks */
244 int devfreq_suspend_device(struct devfreq *devfreq);
245 int devfreq_resume_device(struct devfreq *devfreq);
246
247 void devfreq_suspend(void);
248 void devfreq_resume(void);
249
250 /* update_devfreq() - Reevaluate the device and configure frequency */
251 int update_devfreq(struct devfreq *devfreq);
252
253 /* Helper functions for devfreq user device driver with OPP. */
254 struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
255 unsigned long *freq, u32 flags);
256 int devfreq_register_opp_notifier(struct device *dev,
257 struct devfreq *devfreq);
258 int devfreq_unregister_opp_notifier(struct device *dev,
259 struct devfreq *devfreq);
260 int devm_devfreq_register_opp_notifier(struct device *dev,
261 struct devfreq *devfreq);
262 void devm_devfreq_unregister_opp_notifier(struct device *dev,
263 struct devfreq *devfreq);
264 int devfreq_register_notifier(struct devfreq *devfreq,
265 struct notifier_block *nb,
266 unsigned int list);
267 int devfreq_unregister_notifier(struct devfreq *devfreq,
268 struct notifier_block *nb,
269 unsigned int list);
270 int devm_devfreq_register_notifier(struct device *dev,
271 struct devfreq *devfreq,
272 struct notifier_block *nb,
273 unsigned int list);
274 void devm_devfreq_unregister_notifier(struct device *dev,
275 struct devfreq *devfreq,
276 struct notifier_block *nb,
277 unsigned int list);
278 struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node);
279 struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
280 const char *phandle_name, int index);
281 #endif /* CONFIG_PM_DEVFREQ */
282
283 /**
284 * struct devfreq_simple_ondemand_data - ``void *data`` fed to struct devfreq
285 * and devfreq_add_device
286 * @upthreshold: If the load is over this value, the frequency jumps.
287 * Specify 0 to use the default. Valid value = 0 to 100.
288 * @downdifferential: If the load is under upthreshold - downdifferential,
289 * the governor may consider slowing the frequency down.
290 * Specify 0 to use the default. Valid value = 0 to 100.
291 * downdifferential < upthreshold must hold.
292 *
293 * If the fed devfreq_simple_ondemand_data pointer is NULL to the governor,
294 * the governor uses the default values.
295 */
296 struct devfreq_simple_ondemand_data {
297 unsigned int upthreshold;
298 unsigned int downdifferential;
299 };
300
301 enum devfreq_parent_dev_type {
302 DEVFREQ_PARENT_DEV,
303 CPUFREQ_PARENT_DEV,
304 };
305
306 /**
307 * struct devfreq_passive_data - ``void *data`` fed to struct devfreq
308 * and devfreq_add_device
309 * @parent: the devfreq instance of parent device.
310 * @get_target_freq: Optional callback, Returns desired operating frequency
311 * for the device using passive governor. That is called
312 * when passive governor should decide the next frequency
313 * by using the new frequency of parent devfreq device
314 * using governors except for passive governor.
315 * If the devfreq device has the specific method to decide
316 * the next frequency, should use this callback.
317 * @parent_type: the parent type of the device.
318 * @this: the devfreq instance of own device.
319 * @nb: the notifier block for DEVFREQ_TRANSITION_NOTIFIER or
320 * CPUFREQ_TRANSITION_NOTIFIER list.
321 * @cpu_data_list: the list of cpu frequency data for all cpufreq_policy.
322 *
323 * The devfreq_passive_data have to set the devfreq instance of parent
324 * device with governors except for the passive governor. But, don't need to
325 * initialize the 'this' and 'nb' field because the devfreq core will handle
326 * them.
327 */
328 struct devfreq_passive_data {
329 /* Should set the devfreq instance of parent device */
330 struct devfreq *parent;
331
332 /* Optional callback to decide the next frequency of passvice device */
333 int (*get_target_freq)(struct devfreq *this, unsigned long *freq);
334
335 /* Should set the type of parent device */
336 enum devfreq_parent_dev_type parent_type;
337
338 /* For passive governor's internal use. Don't need to set them */
339 struct devfreq *this;
340 struct notifier_block nb;
341 struct list_head cpu_data_list;
342 };
343
344 #if !defined(CONFIG_PM_DEVFREQ)
devfreq_add_device(struct device * dev,struct devfreq_dev_profile * profile,const char * governor_name,void * data)345 static inline struct devfreq *devfreq_add_device(struct device *dev,
346 struct devfreq_dev_profile *profile,
347 const char *governor_name,
348 void *data)
349 {
350 return ERR_PTR(-ENOSYS);
351 }
352
devfreq_remove_device(struct devfreq * devfreq)353 static inline int devfreq_remove_device(struct devfreq *devfreq)
354 {
355 return 0;
356 }
357
devm_devfreq_add_device(struct device * dev,struct devfreq_dev_profile * profile,const char * governor_name,void * data)358 static inline struct devfreq *devm_devfreq_add_device(struct device *dev,
359 struct devfreq_dev_profile *profile,
360 const char *governor_name,
361 void *data)
362 {
363 return ERR_PTR(-ENOSYS);
364 }
365
devm_devfreq_remove_device(struct device * dev,struct devfreq * devfreq)366 static inline void devm_devfreq_remove_device(struct device *dev,
367 struct devfreq *devfreq)
368 {
369 }
370
devfreq_suspend_device(struct devfreq * devfreq)371 static inline int devfreq_suspend_device(struct devfreq *devfreq)
372 {
373 return 0;
374 }
375
devfreq_resume_device(struct devfreq * devfreq)376 static inline int devfreq_resume_device(struct devfreq *devfreq)
377 {
378 return 0;
379 }
380
devfreq_suspend(void)381 static inline void devfreq_suspend(void) {}
devfreq_resume(void)382 static inline void devfreq_resume(void) {}
383
devfreq_recommended_opp(struct device * dev,unsigned long * freq,u32 flags)384 static inline struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
385 unsigned long *freq, u32 flags)
386 {
387 return ERR_PTR(-EINVAL);
388 }
389
devfreq_register_opp_notifier(struct device * dev,struct devfreq * devfreq)390 static inline int devfreq_register_opp_notifier(struct device *dev,
391 struct devfreq *devfreq)
392 {
393 return -EINVAL;
394 }
395
devfreq_unregister_opp_notifier(struct device * dev,struct devfreq * devfreq)396 static inline int devfreq_unregister_opp_notifier(struct device *dev,
397 struct devfreq *devfreq)
398 {
399 return -EINVAL;
400 }
401
devm_devfreq_register_opp_notifier(struct device * dev,struct devfreq * devfreq)402 static inline int devm_devfreq_register_opp_notifier(struct device *dev,
403 struct devfreq *devfreq)
404 {
405 return -EINVAL;
406 }
407
devm_devfreq_unregister_opp_notifier(struct device * dev,struct devfreq * devfreq)408 static inline void devm_devfreq_unregister_opp_notifier(struct device *dev,
409 struct devfreq *devfreq)
410 {
411 }
412
devfreq_register_notifier(struct devfreq * devfreq,struct notifier_block * nb,unsigned int list)413 static inline int devfreq_register_notifier(struct devfreq *devfreq,
414 struct notifier_block *nb,
415 unsigned int list)
416 {
417 return 0;
418 }
419
devfreq_unregister_notifier(struct devfreq * devfreq,struct notifier_block * nb,unsigned int list)420 static inline int devfreq_unregister_notifier(struct devfreq *devfreq,
421 struct notifier_block *nb,
422 unsigned int list)
423 {
424 return 0;
425 }
426
devm_devfreq_register_notifier(struct device * dev,struct devfreq * devfreq,struct notifier_block * nb,unsigned int list)427 static inline int devm_devfreq_register_notifier(struct device *dev,
428 struct devfreq *devfreq,
429 struct notifier_block *nb,
430 unsigned int list)
431 {
432 return 0;
433 }
434
devm_devfreq_unregister_notifier(struct device * dev,struct devfreq * devfreq,struct notifier_block * nb,unsigned int list)435 static inline void devm_devfreq_unregister_notifier(struct device *dev,
436 struct devfreq *devfreq,
437 struct notifier_block *nb,
438 unsigned int list)
439 {
440 }
441
devfreq_get_devfreq_by_node(struct device_node * node)442 static inline struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node)
443 {
444 return ERR_PTR(-ENODEV);
445 }
446
devfreq_get_devfreq_by_phandle(struct device * dev,const char * phandle_name,int index)447 static inline struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
448 const char *phandle_name, int index)
449 {
450 return ERR_PTR(-ENODEV);
451 }
452
devfreq_update_stats(struct devfreq * df)453 static inline int devfreq_update_stats(struct devfreq *df)
454 {
455 return -EINVAL;
456 }
457 #endif /* CONFIG_PM_DEVFREQ */
458
459 #endif /* __LINUX_DEVFREQ_H__ */
460