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a3c98b8b MH |
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> | |
e4db1c74 | 18 | #include <linux/pm_opp.h> |
a3c98b8b MH |
19 | |
20 | #define DEVFREQ_NAME_LEN 16 | |
21 | ||
22 | struct devfreq; | |
23 | ||
24 | /** | |
25 | * struct devfreq_dev_status - Data given from devfreq user device to | |
26 | * governors. Represents the performance | |
27 | * statistics. | |
e09651fc | 28 | * @total_time: The total time represented by this instance of |
a3c98b8b | 29 | * devfreq_dev_status |
e09651fc | 30 | * @busy_time: The time that the device was working among the |
a3c98b8b | 31 | * total_time. |
e09651fc NM |
32 | * @current_frequency: The operating frequency. |
33 | * @private_data: An entry not specified by the devfreq framework. | |
a3c98b8b MH |
34 | * A device and a specific governor may have their |
35 | * own protocol with private_data. However, because | |
36 | * this is governor-specific, a governor using this | |
37 | * will be only compatible with devices aware of it. | |
38 | */ | |
39 | struct devfreq_dev_status { | |
40 | /* both since the last measure */ | |
41 | unsigned long total_time; | |
42 | unsigned long busy_time; | |
43 | unsigned long current_frequency; | |
1a51cfdc | 44 | void *private_data; |
a3c98b8b MH |
45 | }; |
46 | ||
ab5f299f MH |
47 | /* |
48 | * The resulting frequency should be at most this. (this bound is the | |
49 | * least upper bound; thus, the resulting freq should be lower or same) | |
50 | * If the flag is not set, the resulting frequency should be at most the | |
51 | * bound (greatest lower bound) | |
52 | */ | |
53 | #define DEVFREQ_FLAG_LEAST_UPPER_BOUND 0x1 | |
54 | ||
a3c98b8b MH |
55 | /** |
56 | * struct devfreq_dev_profile - Devfreq's user device profile | |
e09651fc | 57 | * @initial_freq: The operating frequency when devfreq_add_device() is |
a3c98b8b | 58 | * called. |
e09651fc NM |
59 | * @polling_ms: The polling interval in ms. 0 disables polling. |
60 | * @target: The device should set its operating frequency at | |
a3c98b8b MH |
61 | * freq or lowest-upper-than-freq value. If freq is |
62 | * higher than any operable frequency, set maximum. | |
63 | * Before returning, target function should set | |
64 | * freq at the current frequency. | |
ab5f299f MH |
65 | * The "flags" parameter's possible values are |
66 | * explained above with "DEVFREQ_FLAG_*" macros. | |
e09651fc | 67 | * @get_dev_status: The device should provide the current performance |
d54cdf3f MH |
68 | * status to devfreq. Governors are recommended not to |
69 | * use this directly. Instead, governors are recommended | |
70 | * to use devfreq_update_stats() along with | |
71 | * devfreq.last_status. | |
e09651fc | 72 | * @get_cur_freq: The device should provide the current frequency |
7f98a905 | 73 | * at which it is operating. |
e09651fc | 74 | * @exit: An optional callback that is called when devfreq |
a3c98b8b MH |
75 | * is removing the devfreq object due to error or |
76 | * from devfreq_remove_device() call. If the user | |
77 | * has registered devfreq->nb at a notifier-head, | |
78 | * this is the time to unregister it. | |
e552bbaf JL |
79 | * @freq_table: Optional list of frequencies to support statistics. |
80 | * @max_state: The size of freq_table. | |
a3c98b8b MH |
81 | */ |
82 | struct devfreq_dev_profile { | |
83 | unsigned long initial_freq; | |
84 | unsigned int polling_ms; | |
85 | ||
ab5f299f | 86 | int (*target)(struct device *dev, unsigned long *freq, u32 flags); |
a3c98b8b MH |
87 | int (*get_dev_status)(struct device *dev, |
88 | struct devfreq_dev_status *stat); | |
7f98a905 | 89 | int (*get_cur_freq)(struct device *dev, unsigned long *freq); |
a3c98b8b | 90 | void (*exit)(struct device *dev); |
e552bbaf JL |
91 | |
92 | unsigned int *freq_table; | |
93 | unsigned int max_state; | |
a3c98b8b MH |
94 | }; |
95 | ||
96 | /** | |
97 | * struct devfreq_governor - Devfreq policy governor | |
3aa173b8 | 98 | * @node: list node - contains registered devfreq governors |
e09651fc NM |
99 | * @name: Governor's name |
100 | * @get_target_freq: Returns desired operating frequency for the device. | |
a3c98b8b MH |
101 | * Basically, get_target_freq will run |
102 | * devfreq_dev_profile.get_dev_status() to get the | |
103 | * status of the device (load = busy_time / total_time). | |
104 | * If no_central_polling is set, this callback is called | |
105 | * only with update_devfreq() notified by OPP. | |
e09651fc | 106 | * @event_handler: Callback for devfreq core framework to notify events |
7e6fdd4b RV |
107 | * to governors. Events include per device governor |
108 | * init and exit, opp changes out of devfreq, suspend | |
109 | * and resume of per device devfreq during device idle. | |
a3c98b8b MH |
110 | * |
111 | * Note that the callbacks are called with devfreq->lock locked by devfreq. | |
112 | */ | |
113 | struct devfreq_governor { | |
3aa173b8 NM |
114 | struct list_head node; |
115 | ||
a3c98b8b MH |
116 | const char name[DEVFREQ_NAME_LEN]; |
117 | int (*get_target_freq)(struct devfreq *this, unsigned long *freq); | |
7e6fdd4b RV |
118 | int (*event_handler)(struct devfreq *devfreq, |
119 | unsigned int event, void *data); | |
a3c98b8b MH |
120 | }; |
121 | ||
122 | /** | |
123 | * struct devfreq - Device devfreq structure | |
e09651fc | 124 | * @node: list node - contains the devices with devfreq that have been |
a3c98b8b | 125 | * registered. |
e09651fc NM |
126 | * @lock: a mutex to protect accessing devfreq. |
127 | * @dev: device registered by devfreq class. dev.parent is the device | |
a3c98b8b | 128 | * using devfreq. |
e09651fc NM |
129 | * @profile: device-specific devfreq profile |
130 | * @governor: method how to choose frequency based on the usage. | |
1b5c1be2 | 131 | * @governor_name: devfreq governor name for use with this devfreq |
e09651fc | 132 | * @nb: notifier block used to notify devfreq object that it should |
a3c98b8b MH |
133 | * reevaluate operable frequencies. Devfreq users may use |
134 | * devfreq.nb to the corresponding register notifier call chain. | |
e09651fc NM |
135 | * @work: delayed work for load monitoring. |
136 | * @previous_freq: previously configured frequency value. | |
137 | * @data: Private data of the governor. The devfreq framework does not | |
a3c98b8b | 138 | * touch this. |
e09651fc NM |
139 | * @min_freq: Limit minimum frequency requested by user (0: none) |
140 | * @max_freq: Limit maximum frequency requested by user (0: none) | |
141 | * @stop_polling: devfreq polling status of a device. | |
e552bbaf JL |
142 | * @total_trans: Number of devfreq transitions |
143 | * @trans_table: Statistics of devfreq transitions | |
144 | * @time_in_state: Statistics of devfreq states | |
145 | * @last_stat_updated: The last time stat updated | |
a3c98b8b MH |
146 | * |
147 | * This structure stores the devfreq information for a give device. | |
148 | * | |
149 | * Note that when a governor accesses entries in struct devfreq in its | |
150 | * functions except for the context of callbacks defined in struct | |
151 | * devfreq_governor, the governor should protect its access with the | |
152 | * struct mutex lock in struct devfreq. A governor may use this mutex | |
153 | * to protect its own private data in void *data as well. | |
154 | */ | |
155 | struct devfreq { | |
156 | struct list_head node; | |
157 | ||
158 | struct mutex lock; | |
159 | struct device dev; | |
160 | struct devfreq_dev_profile *profile; | |
161 | const struct devfreq_governor *governor; | |
1b5c1be2 | 162 | char governor_name[DEVFREQ_NAME_LEN]; |
a3c98b8b | 163 | struct notifier_block nb; |
7e6fdd4b | 164 | struct delayed_work work; |
a3c98b8b | 165 | |
a3c98b8b | 166 | unsigned long previous_freq; |
08e75e75 | 167 | struct devfreq_dev_status last_status; |
a3c98b8b MH |
168 | |
169 | void *data; /* private data for governors */ | |
170 | ||
6530b9de MH |
171 | unsigned long min_freq; |
172 | unsigned long max_freq; | |
7e6fdd4b | 173 | bool stop_polling; |
e552bbaf | 174 | |
0585123e | 175 | /* information for device frequency transition */ |
e552bbaf JL |
176 | unsigned int total_trans; |
177 | unsigned int *trans_table; | |
178 | unsigned long *time_in_state; | |
179 | unsigned long last_stat_updated; | |
a3c98b8b MH |
180 | }; |
181 | ||
182 | #if defined(CONFIG_PM_DEVFREQ) | |
183 | extern struct devfreq *devfreq_add_device(struct device *dev, | |
184 | struct devfreq_dev_profile *profile, | |
1b5c1be2 | 185 | const char *governor_name, |
a3c98b8b MH |
186 | void *data); |
187 | extern int devfreq_remove_device(struct devfreq *devfreq); | |
8cd84092 CC |
188 | extern struct devfreq *devm_devfreq_add_device(struct device *dev, |
189 | struct devfreq_dev_profile *profile, | |
190 | const char *governor_name, | |
191 | void *data); | |
192 | extern void devm_devfreq_remove_device(struct device *dev, | |
193 | struct devfreq *devfreq); | |
de9c7394 | 194 | |
464ed18e | 195 | /* Supposed to be called by PM callbacks */ |
206c30cf RV |
196 | extern int devfreq_suspend_device(struct devfreq *devfreq); |
197 | extern int devfreq_resume_device(struct devfreq *devfreq); | |
a3c98b8b MH |
198 | |
199 | /* Helper functions for devfreq user device driver with OPP. */ | |
47d43ba7 | 200 | extern struct dev_pm_opp *devfreq_recommended_opp(struct device *dev, |
ab5f299f | 201 | unsigned long *freq, u32 flags); |
a3c98b8b MH |
202 | extern int devfreq_register_opp_notifier(struct device *dev, |
203 | struct devfreq *devfreq); | |
204 | extern int devfreq_unregister_opp_notifier(struct device *dev, | |
205 | struct devfreq *devfreq); | |
d5b040d0 CC |
206 | extern int devm_devfreq_register_opp_notifier(struct device *dev, |
207 | struct devfreq *devfreq); | |
208 | extern void devm_devfreq_unregister_opp_notifier(struct device *dev, | |
209 | struct devfreq *devfreq); | |
a3c98b8b | 210 | |
08e75e75 JM |
211 | /** |
212 | * devfreq_update_stats() - update the last_status pointer in struct devfreq | |
213 | * @df: the devfreq instance whose status needs updating | |
d54cdf3f MH |
214 | * |
215 | * Governors are recommended to use this function along with last_status, | |
216 | * which allows other entities to reuse the last_status without affecting | |
217 | * the values fetched later by governors. | |
08e75e75 JM |
218 | */ |
219 | static inline int devfreq_update_stats(struct devfreq *df) | |
220 | { | |
221 | return df->profile->get_dev_status(df->dev.parent, &df->last_status); | |
222 | } | |
223 | ||
883d588e | 224 | #if IS_ENABLED(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND) |
ce26c5bb MH |
225 | /** |
226 | * struct devfreq_simple_ondemand_data - void *data fed to struct devfreq | |
227 | * and devfreq_add_device | |
e09651fc | 228 | * @upthreshold: If the load is over this value, the frequency jumps. |
ce26c5bb | 229 | * Specify 0 to use the default. Valid value = 0 to 100. |
e09651fc | 230 | * @downdifferential: If the load is under upthreshold - downdifferential, |
ce26c5bb MH |
231 | * the governor may consider slowing the frequency down. |
232 | * Specify 0 to use the default. Valid value = 0 to 100. | |
233 | * downdifferential < upthreshold must hold. | |
234 | * | |
235 | * If the fed devfreq_simple_ondemand_data pointer is NULL to the governor, | |
236 | * the governor uses the default values. | |
237 | */ | |
238 | struct devfreq_simple_ondemand_data { | |
239 | unsigned int upthreshold; | |
240 | unsigned int downdifferential; | |
241 | }; | |
242 | #endif | |
243 | ||
a3c98b8b | 244 | #else /* !CONFIG_PM_DEVFREQ */ |
5faaa035 | 245 | static inline struct devfreq *devfreq_add_device(struct device *dev, |
a3c98b8b | 246 | struct devfreq_dev_profile *profile, |
1b5c1be2 | 247 | const char *governor_name, |
a95e1f5d | 248 | void *data) |
a3c98b8b | 249 | { |
8cd84092 | 250 | return ERR_PTR(-ENOSYS); |
a3c98b8b MH |
251 | } |
252 | ||
5faaa035 | 253 | static inline int devfreq_remove_device(struct devfreq *devfreq) |
a3c98b8b MH |
254 | { |
255 | return 0; | |
256 | } | |
257 | ||
8cd84092 CC |
258 | static inline struct devfreq *devm_devfreq_add_device(struct device *dev, |
259 | struct devfreq_dev_profile *profile, | |
260 | const char *governor_name, | |
261 | void *data) | |
262 | { | |
263 | return ERR_PTR(-ENOSYS); | |
264 | } | |
265 | ||
266 | static inline void devm_devfreq_remove_device(struct device *dev, | |
267 | struct devfreq *devfreq) | |
268 | { | |
269 | } | |
270 | ||
5faaa035 | 271 | static inline int devfreq_suspend_device(struct devfreq *devfreq) |
206c30cf RV |
272 | { |
273 | return 0; | |
274 | } | |
275 | ||
5faaa035 | 276 | static inline int devfreq_resume_device(struct devfreq *devfreq) |
206c30cf RV |
277 | { |
278 | return 0; | |
279 | } | |
280 | ||
47d43ba7 | 281 | static inline struct dev_pm_opp *devfreq_recommended_opp(struct device *dev, |
ab5f299f | 282 | unsigned long *freq, u32 flags) |
a3c98b8b | 283 | { |
5faaa035 | 284 | return ERR_PTR(-EINVAL); |
a3c98b8b MH |
285 | } |
286 | ||
5faaa035 | 287 | static inline int devfreq_register_opp_notifier(struct device *dev, |
a3c98b8b MH |
288 | struct devfreq *devfreq) |
289 | { | |
290 | return -EINVAL; | |
291 | } | |
292 | ||
5faaa035 | 293 | static inline int devfreq_unregister_opp_notifier(struct device *dev, |
a3c98b8b MH |
294 | struct devfreq *devfreq) |
295 | { | |
296 | return -EINVAL; | |
297 | } | |
298 | ||
d5b040d0 CC |
299 | static inline int devm_devfreq_register_opp_notifier(struct device *dev, |
300 | struct devfreq *devfreq) | |
301 | { | |
302 | return -EINVAL; | |
303 | } | |
304 | ||
305 | static inline void devm_devfreq_unregister_opp_notifier(struct device *dev, | |
306 | struct devfreq *devfreq) | |
307 | { | |
308 | } | |
08e75e75 JM |
309 | |
310 | static inline int devfreq_update_stats(struct devfreq *df) | |
311 | { | |
312 | return -EINVAL; | |
313 | } | |
a3c98b8b MH |
314 | #endif /* CONFIG_PM_DEVFREQ */ |
315 | ||
316 | #endif /* __LINUX_DEVFREQ_H__ */ |