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