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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> | |
18 | #include <linux/opp.h> | |
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 |
a3c98b8b | 68 | * status to devfreq, which is used by governors. |
e09651fc | 69 | * @get_cur_freq: The device should provide the current frequency |
7f98a905 | 70 | * at which it is operating. |
e09651fc | 71 | * @exit: An optional callback that is called when devfreq |
a3c98b8b MH |
72 | * is removing the devfreq object due to error or |
73 | * from devfreq_remove_device() call. If the user | |
74 | * has registered devfreq->nb at a notifier-head, | |
75 | * this is the time to unregister it. | |
e552bbaf JL |
76 | * @freq_table: Optional list of frequencies to support statistics. |
77 | * @max_state: The size of freq_table. | |
a3c98b8b MH |
78 | */ |
79 | struct devfreq_dev_profile { | |
80 | unsigned long initial_freq; | |
81 | unsigned int polling_ms; | |
82 | ||
ab5f299f | 83 | int (*target)(struct device *dev, unsigned long *freq, u32 flags); |
a3c98b8b MH |
84 | int (*get_dev_status)(struct device *dev, |
85 | struct devfreq_dev_status *stat); | |
7f98a905 | 86 | int (*get_cur_freq)(struct device *dev, unsigned long *freq); |
a3c98b8b | 87 | void (*exit)(struct device *dev); |
e552bbaf JL |
88 | |
89 | unsigned int *freq_table; | |
90 | unsigned int max_state; | |
a3c98b8b MH |
91 | }; |
92 | ||
93 | /** | |
94 | * struct devfreq_governor - Devfreq policy governor | |
3aa173b8 | 95 | * @node: list node - contains registered devfreq governors |
e09651fc NM |
96 | * @name: Governor's name |
97 | * @get_target_freq: Returns desired operating frequency for the device. | |
a3c98b8b MH |
98 | * Basically, get_target_freq will run |
99 | * devfreq_dev_profile.get_dev_status() to get the | |
100 | * status of the device (load = busy_time / total_time). | |
101 | * If no_central_polling is set, this callback is called | |
102 | * only with update_devfreq() notified by OPP. | |
e09651fc | 103 | * @event_handler: Callback for devfreq core framework to notify events |
7e6fdd4b RV |
104 | * to governors. Events include per device governor |
105 | * init and exit, opp changes out of devfreq, suspend | |
106 | * and resume of per device devfreq during device idle. | |
a3c98b8b MH |
107 | * |
108 | * Note that the callbacks are called with devfreq->lock locked by devfreq. | |
109 | */ | |
110 | struct devfreq_governor { | |
3aa173b8 NM |
111 | struct list_head node; |
112 | ||
a3c98b8b MH |
113 | const char name[DEVFREQ_NAME_LEN]; |
114 | int (*get_target_freq)(struct devfreq *this, unsigned long *freq); | |
7e6fdd4b RV |
115 | int (*event_handler)(struct devfreq *devfreq, |
116 | unsigned int event, void *data); | |
a3c98b8b MH |
117 | }; |
118 | ||
119 | /** | |
120 | * struct devfreq - Device devfreq structure | |
e09651fc | 121 | * @node: list node - contains the devices with devfreq that have been |
a3c98b8b | 122 | * registered. |
e09651fc NM |
123 | * @lock: a mutex to protect accessing devfreq. |
124 | * @dev: device registered by devfreq class. dev.parent is the device | |
a3c98b8b | 125 | * using devfreq. |
e09651fc NM |
126 | * @profile: device-specific devfreq profile |
127 | * @governor: method how to choose frequency based on the usage. | |
1b5c1be2 | 128 | * @governor_name: devfreq governor name for use with this devfreq |
e09651fc | 129 | * @nb: notifier block used to notify devfreq object that it should |
a3c98b8b MH |
130 | * reevaluate operable frequencies. Devfreq users may use |
131 | * devfreq.nb to the corresponding register notifier call chain. | |
e09651fc NM |
132 | * @work: delayed work for load monitoring. |
133 | * @previous_freq: previously configured frequency value. | |
134 | * @data: Private data of the governor. The devfreq framework does not | |
a3c98b8b | 135 | * touch this. |
e09651fc NM |
136 | * @min_freq: Limit minimum frequency requested by user (0: none) |
137 | * @max_freq: Limit maximum frequency requested by user (0: none) | |
138 | * @stop_polling: devfreq polling status of a device. | |
e552bbaf JL |
139 | * @total_trans: Number of devfreq transitions |
140 | * @trans_table: Statistics of devfreq transitions | |
141 | * @time_in_state: Statistics of devfreq states | |
142 | * @last_stat_updated: The last time stat updated | |
a3c98b8b MH |
143 | * |
144 | * This structure stores the devfreq information for a give device. | |
145 | * | |
146 | * Note that when a governor accesses entries in struct devfreq in its | |
147 | * functions except for the context of callbacks defined in struct | |
148 | * devfreq_governor, the governor should protect its access with the | |
149 | * struct mutex lock in struct devfreq. A governor may use this mutex | |
150 | * to protect its own private data in void *data as well. | |
151 | */ | |
152 | struct devfreq { | |
153 | struct list_head node; | |
154 | ||
155 | struct mutex lock; | |
156 | struct device dev; | |
157 | struct devfreq_dev_profile *profile; | |
158 | const struct devfreq_governor *governor; | |
1b5c1be2 | 159 | char governor_name[DEVFREQ_NAME_LEN]; |
a3c98b8b | 160 | struct notifier_block nb; |
7e6fdd4b | 161 | struct delayed_work work; |
a3c98b8b | 162 | |
a3c98b8b | 163 | unsigned long previous_freq; |
a3c98b8b MH |
164 | |
165 | void *data; /* private data for governors */ | |
166 | ||
6530b9de MH |
167 | unsigned long min_freq; |
168 | unsigned long max_freq; | |
7e6fdd4b | 169 | bool stop_polling; |
e552bbaf JL |
170 | |
171 | /* information for device freqeuncy transition */ | |
172 | unsigned int total_trans; | |
173 | unsigned int *trans_table; | |
174 | unsigned long *time_in_state; | |
175 | unsigned long last_stat_updated; | |
a3c98b8b MH |
176 | }; |
177 | ||
178 | #if defined(CONFIG_PM_DEVFREQ) | |
179 | extern struct devfreq *devfreq_add_device(struct device *dev, | |
180 | struct devfreq_dev_profile *profile, | |
1b5c1be2 | 181 | const char *governor_name, |
a3c98b8b MH |
182 | void *data); |
183 | extern int devfreq_remove_device(struct devfreq *devfreq); | |
206c30cf RV |
184 | extern int devfreq_suspend_device(struct devfreq *devfreq); |
185 | extern int devfreq_resume_device(struct devfreq *devfreq); | |
a3c98b8b MH |
186 | |
187 | /* Helper functions for devfreq user device driver with OPP. */ | |
188 | extern struct opp *devfreq_recommended_opp(struct device *dev, | |
ab5f299f | 189 | unsigned long *freq, u32 flags); |
a3c98b8b MH |
190 | extern int devfreq_register_opp_notifier(struct device *dev, |
191 | struct devfreq *devfreq); | |
192 | extern int devfreq_unregister_opp_notifier(struct device *dev, | |
193 | struct devfreq *devfreq); | |
194 | ||
883d588e | 195 | #if IS_ENABLED(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND) |
ce26c5bb MH |
196 | /** |
197 | * struct devfreq_simple_ondemand_data - void *data fed to struct devfreq | |
198 | * and devfreq_add_device | |
e09651fc | 199 | * @upthreshold: If the load is over this value, the frequency jumps. |
ce26c5bb | 200 | * Specify 0 to use the default. Valid value = 0 to 100. |
e09651fc | 201 | * @downdifferential: If the load is under upthreshold - downdifferential, |
ce26c5bb MH |
202 | * the governor may consider slowing the frequency down. |
203 | * Specify 0 to use the default. Valid value = 0 to 100. | |
204 | * downdifferential < upthreshold must hold. | |
205 | * | |
206 | * If the fed devfreq_simple_ondemand_data pointer is NULL to the governor, | |
207 | * the governor uses the default values. | |
208 | */ | |
209 | struct devfreq_simple_ondemand_data { | |
210 | unsigned int upthreshold; | |
211 | unsigned int downdifferential; | |
212 | }; | |
213 | #endif | |
214 | ||
a3c98b8b | 215 | #else /* !CONFIG_PM_DEVFREQ */ |
5faaa035 | 216 | static inline struct devfreq *devfreq_add_device(struct device *dev, |
a3c98b8b | 217 | struct devfreq_dev_profile *profile, |
1b5c1be2 | 218 | const char *governor_name, |
a95e1f5d | 219 | void *data) |
a3c98b8b MH |
220 | { |
221 | return NULL; | |
222 | } | |
223 | ||
5faaa035 | 224 | static inline int devfreq_remove_device(struct devfreq *devfreq) |
a3c98b8b MH |
225 | { |
226 | return 0; | |
227 | } | |
228 | ||
5faaa035 | 229 | static inline int devfreq_suspend_device(struct devfreq *devfreq) |
206c30cf RV |
230 | { |
231 | return 0; | |
232 | } | |
233 | ||
5faaa035 | 234 | static inline int devfreq_resume_device(struct devfreq *devfreq) |
206c30cf RV |
235 | { |
236 | return 0; | |
237 | } | |
238 | ||
5faaa035 | 239 | static inline struct opp *devfreq_recommended_opp(struct device *dev, |
ab5f299f | 240 | unsigned long *freq, u32 flags) |
a3c98b8b | 241 | { |
5faaa035 | 242 | return ERR_PTR(-EINVAL); |
a3c98b8b MH |
243 | } |
244 | ||
5faaa035 | 245 | static inline int devfreq_register_opp_notifier(struct device *dev, |
a3c98b8b MH |
246 | struct devfreq *devfreq) |
247 | { | |
248 | return -EINVAL; | |
249 | } | |
250 | ||
5faaa035 | 251 | static inline int devfreq_unregister_opp_notifier(struct device *dev, |
a3c98b8b MH |
252 | struct devfreq *devfreq) |
253 | { | |
254 | return -EINVAL; | |
255 | } | |
256 | ||
257 | #endif /* CONFIG_PM_DEVFREQ */ | |
258 | ||
259 | #endif /* __LINUX_DEVFREQ_H__ */ |