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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 | |
e09651fc NM |
95 | * @name: Governor's name |
96 | * @get_target_freq: Returns desired operating frequency for the device. | |
a3c98b8b MH |
97 | * Basically, get_target_freq will run |
98 | * devfreq_dev_profile.get_dev_status() to get the | |
99 | * status of the device (load = busy_time / total_time). | |
100 | * If no_central_polling is set, this callback is called | |
101 | * only with update_devfreq() notified by OPP. | |
e09651fc | 102 | * @event_handler: Callback for devfreq core framework to notify events |
7e6fdd4b RV |
103 | * to governors. Events include per device governor |
104 | * init and exit, opp changes out of devfreq, suspend | |
105 | * and resume of per device devfreq during device idle. | |
a3c98b8b MH |
106 | * |
107 | * Note that the callbacks are called with devfreq->lock locked by devfreq. | |
108 | */ | |
109 | struct devfreq_governor { | |
110 | const char name[DEVFREQ_NAME_LEN]; | |
111 | int (*get_target_freq)(struct devfreq *this, unsigned long *freq); | |
7e6fdd4b RV |
112 | int (*event_handler)(struct devfreq *devfreq, |
113 | unsigned int event, void *data); | |
a3c98b8b MH |
114 | }; |
115 | ||
116 | /** | |
117 | * struct devfreq - Device devfreq structure | |
e09651fc | 118 | * @node: list node - contains the devices with devfreq that have been |
a3c98b8b | 119 | * registered. |
e09651fc NM |
120 | * @lock: a mutex to protect accessing devfreq. |
121 | * @dev: device registered by devfreq class. dev.parent is the device | |
a3c98b8b | 122 | * using devfreq. |
e09651fc NM |
123 | * @profile: device-specific devfreq profile |
124 | * @governor: method how to choose frequency based on the usage. | |
125 | * @nb: notifier block used to notify devfreq object that it should | |
a3c98b8b MH |
126 | * reevaluate operable frequencies. Devfreq users may use |
127 | * devfreq.nb to the corresponding register notifier call chain. | |
e09651fc NM |
128 | * @work: delayed work for load monitoring. |
129 | * @previous_freq: previously configured frequency value. | |
130 | * @data: Private data of the governor. The devfreq framework does not | |
a3c98b8b | 131 | * touch this. |
e09651fc NM |
132 | * @min_freq: Limit minimum frequency requested by user (0: none) |
133 | * @max_freq: Limit maximum frequency requested by user (0: none) | |
134 | * @stop_polling: devfreq polling status of a device. | |
e552bbaf JL |
135 | * @total_trans: Number of devfreq transitions |
136 | * @trans_table: Statistics of devfreq transitions | |
137 | * @time_in_state: Statistics of devfreq states | |
138 | * @last_stat_updated: The last time stat updated | |
a3c98b8b MH |
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 | struct notifier_block nb; | |
7e6fdd4b | 156 | struct delayed_work work; |
a3c98b8b | 157 | |
a3c98b8b | 158 | unsigned long previous_freq; |
a3c98b8b MH |
159 | |
160 | void *data; /* private data for governors */ | |
161 | ||
6530b9de MH |
162 | unsigned long min_freq; |
163 | unsigned long max_freq; | |
7e6fdd4b | 164 | bool stop_polling; |
e552bbaf JL |
165 | |
166 | /* information for device freqeuncy transition */ | |
167 | unsigned int total_trans; | |
168 | unsigned int *trans_table; | |
169 | unsigned long *time_in_state; | |
170 | unsigned long last_stat_updated; | |
a3c98b8b MH |
171 | }; |
172 | ||
173 | #if defined(CONFIG_PM_DEVFREQ) | |
174 | extern struct devfreq *devfreq_add_device(struct device *dev, | |
175 | struct devfreq_dev_profile *profile, | |
176 | const struct devfreq_governor *governor, | |
177 | void *data); | |
178 | extern int devfreq_remove_device(struct devfreq *devfreq); | |
206c30cf RV |
179 | extern int devfreq_suspend_device(struct devfreq *devfreq); |
180 | extern int devfreq_resume_device(struct devfreq *devfreq); | |
a3c98b8b MH |
181 | |
182 | /* Helper functions for devfreq user device driver with OPP. */ | |
183 | extern struct opp *devfreq_recommended_opp(struct device *dev, | |
ab5f299f | 184 | unsigned long *freq, u32 flags); |
a3c98b8b MH |
185 | extern int devfreq_register_opp_notifier(struct device *dev, |
186 | struct devfreq *devfreq); | |
187 | extern int devfreq_unregister_opp_notifier(struct device *dev, | |
188 | struct devfreq *devfreq); | |
189 | ||
ce26c5bb MH |
190 | #ifdef CONFIG_DEVFREQ_GOV_POWERSAVE |
191 | extern const struct devfreq_governor devfreq_powersave; | |
192 | #endif | |
193 | #ifdef CONFIG_DEVFREQ_GOV_PERFORMANCE | |
194 | extern const struct devfreq_governor devfreq_performance; | |
195 | #endif | |
196 | #ifdef CONFIG_DEVFREQ_GOV_USERSPACE | |
197 | extern const struct devfreq_governor devfreq_userspace; | |
198 | #endif | |
199 | #ifdef CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND | |
200 | extern const struct devfreq_governor devfreq_simple_ondemand; | |
201 | /** | |
202 | * struct devfreq_simple_ondemand_data - void *data fed to struct devfreq | |
203 | * and devfreq_add_device | |
e09651fc | 204 | * @upthreshold: If the load is over this value, the frequency jumps. |
ce26c5bb | 205 | * Specify 0 to use the default. Valid value = 0 to 100. |
e09651fc | 206 | * @downdifferential: If the load is under upthreshold - downdifferential, |
ce26c5bb MH |
207 | * the governor may consider slowing the frequency down. |
208 | * Specify 0 to use the default. Valid value = 0 to 100. | |
209 | * downdifferential < upthreshold must hold. | |
210 | * | |
211 | * If the fed devfreq_simple_ondemand_data pointer is NULL to the governor, | |
212 | * the governor uses the default values. | |
213 | */ | |
214 | struct devfreq_simple_ondemand_data { | |
215 | unsigned int upthreshold; | |
216 | unsigned int downdifferential; | |
217 | }; | |
218 | #endif | |
219 | ||
a3c98b8b MH |
220 | #else /* !CONFIG_PM_DEVFREQ */ |
221 | static struct devfreq *devfreq_add_device(struct device *dev, | |
222 | struct devfreq_dev_profile *profile, | |
223 | struct devfreq_governor *governor, | |
a95e1f5d | 224 | void *data) |
a3c98b8b MH |
225 | { |
226 | return NULL; | |
227 | } | |
228 | ||
a95e1f5d | 229 | static int devfreq_remove_device(struct devfreq *devfreq) |
a3c98b8b MH |
230 | { |
231 | return 0; | |
232 | } | |
233 | ||
206c30cf RV |
234 | static int devfreq_suspend_device(struct devfreq *devfreq) |
235 | { | |
236 | return 0; | |
237 | } | |
238 | ||
239 | static int devfreq_resume_device(struct devfreq *devfreq) | |
240 | { | |
241 | return 0; | |
242 | } | |
243 | ||
a3c98b8b | 244 | static struct opp *devfreq_recommended_opp(struct device *dev, |
ab5f299f | 245 | unsigned long *freq, u32 flags) |
a3c98b8b MH |
246 | { |
247 | return -EINVAL; | |
248 | } | |
249 | ||
250 | static int devfreq_register_opp_notifier(struct device *dev, | |
251 | struct devfreq *devfreq) | |
252 | { | |
253 | return -EINVAL; | |
254 | } | |
255 | ||
256 | static int devfreq_unregister_opp_notifier(struct device *dev, | |
257 | struct devfreq *devfreq) | |
258 | { | |
259 | return -EINVAL; | |
260 | } | |
261 | ||
ce26c5bb MH |
262 | #define devfreq_powersave NULL |
263 | #define devfreq_performance NULL | |
264 | #define devfreq_userspace NULL | |
265 | #define devfreq_simple_ondemand NULL | |
266 | ||
a3c98b8b MH |
267 | #endif /* CONFIG_PM_DEVFREQ */ |
268 | ||
269 | #endif /* __LINUX_DEVFREQ_H__ */ |