MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 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. |
Nishanth Menon | e09651f | 2012-10-29 08:02:23 -0500 | [diff] [blame] | 28 | * @total_time: The total time represented by this instance of |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 29 | * devfreq_dev_status |
Nishanth Menon | e09651f | 2012-10-29 08:02:23 -0500 | [diff] [blame] | 30 | * @busy_time: The time that the device was working among the |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 31 | * total_time. |
Nishanth Menon | e09651f | 2012-10-29 08:02:23 -0500 | [diff] [blame] | 32 | * @current_frequency: The operating frequency. |
| 33 | * @private_data: An entry not specified by the devfreq framework. |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 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; |
Jonathan Corbet | 1a51cfd | 2011-11-07 23:54:53 +0100 | [diff] [blame] | 44 | void *private_data; |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 45 | }; |
| 46 | |
MyungJoo Ham | ab5f299 | 2012-03-16 21:54:53 +0100 | [diff] [blame] | 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 | |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 55 | /** |
| 56 | * struct devfreq_dev_profile - Devfreq's user device profile |
Nishanth Menon | e09651f | 2012-10-29 08:02:23 -0500 | [diff] [blame] | 57 | * @initial_freq: The operating frequency when devfreq_add_device() is |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 58 | * called. |
Nishanth Menon | e09651f | 2012-10-29 08:02:23 -0500 | [diff] [blame] | 59 | * @polling_ms: The polling interval in ms. 0 disables polling. |
| 60 | * @target: The device should set its operating frequency at |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 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. |
MyungJoo Ham | ab5f299 | 2012-03-16 21:54:53 +0100 | [diff] [blame] | 65 | * The "flags" parameter's possible values are |
| 66 | * explained above with "DEVFREQ_FLAG_*" macros. |
Nishanth Menon | e09651f | 2012-10-29 08:02:23 -0500 | [diff] [blame] | 67 | * @get_dev_status: The device should provide the current performance |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 68 | * status to devfreq, which is used by governors. |
Nishanth Menon | e09651f | 2012-10-29 08:02:23 -0500 | [diff] [blame] | 69 | * @get_cur_freq: The device should provide the current frequency |
Rajagopal Venkat | 7f98a90 | 2012-10-26 01:50:26 +0200 | [diff] [blame] | 70 | * at which it is operating. |
Nishanth Menon | e09651f | 2012-10-29 08:02:23 -0500 | [diff] [blame] | 71 | * @exit: An optional callback that is called when devfreq |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 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. |
Jonghwa Lee | e552bba | 2012-08-23 20:00:46 +0900 | [diff] [blame] | 76 | * @freq_table: Optional list of frequencies to support statistics. |
| 77 | * @max_state: The size of freq_table. |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 78 | */ |
| 79 | struct devfreq_dev_profile { |
| 80 | unsigned long initial_freq; |
| 81 | unsigned int polling_ms; |
| 82 | |
MyungJoo Ham | ab5f299 | 2012-03-16 21:54:53 +0100 | [diff] [blame] | 83 | int (*target)(struct device *dev, unsigned long *freq, u32 flags); |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 84 | int (*get_dev_status)(struct device *dev, |
| 85 | struct devfreq_dev_status *stat); |
Rajagopal Venkat | 7f98a90 | 2012-10-26 01:50:26 +0200 | [diff] [blame] | 86 | int (*get_cur_freq)(struct device *dev, unsigned long *freq); |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 87 | void (*exit)(struct device *dev); |
Jonghwa Lee | e552bba | 2012-08-23 20:00:46 +0900 | [diff] [blame] | 88 | |
| 89 | unsigned int *freq_table; |
| 90 | unsigned int max_state; |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 91 | }; |
| 92 | |
| 93 | /** |
| 94 | * struct devfreq_governor - Devfreq policy governor |
Nishanth Menon | 3aa173b | 2012-10-29 15:01:43 -0500 | [diff] [blame] | 95 | * @node: list node - contains registered devfreq governors |
Nishanth Menon | e09651f | 2012-10-29 08:02:23 -0500 | [diff] [blame] | 96 | * @name: Governor's name |
| 97 | * @get_target_freq: Returns desired operating frequency for the device. |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 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. |
Nishanth Menon | e09651f | 2012-10-29 08:02:23 -0500 | [diff] [blame] | 103 | * @event_handler: Callback for devfreq core framework to notify events |
Rajagopal Venkat | 7e6fdd4 | 2012-10-26 01:50:09 +0200 | [diff] [blame] | 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. |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 107 | * |
| 108 | * Note that the callbacks are called with devfreq->lock locked by devfreq. |
| 109 | */ |
| 110 | struct devfreq_governor { |
Nishanth Menon | 3aa173b | 2012-10-29 15:01:43 -0500 | [diff] [blame] | 111 | struct list_head node; |
| 112 | |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 113 | const char name[DEVFREQ_NAME_LEN]; |
| 114 | int (*get_target_freq)(struct devfreq *this, unsigned long *freq); |
Rajagopal Venkat | 7e6fdd4 | 2012-10-26 01:50:09 +0200 | [diff] [blame] | 115 | int (*event_handler)(struct devfreq *devfreq, |
| 116 | unsigned int event, void *data); |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 117 | }; |
| 118 | |
| 119 | /** |
| 120 | * struct devfreq - Device devfreq structure |
Nishanth Menon | e09651f | 2012-10-29 08:02:23 -0500 | [diff] [blame] | 121 | * @node: list node - contains the devices with devfreq that have been |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 122 | * registered. |
Nishanth Menon | e09651f | 2012-10-29 08:02:23 -0500 | [diff] [blame] | 123 | * @lock: a mutex to protect accessing devfreq. |
| 124 | * @dev: device registered by devfreq class. dev.parent is the device |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 125 | * using devfreq. |
Nishanth Menon | e09651f | 2012-10-29 08:02:23 -0500 | [diff] [blame] | 126 | * @profile: device-specific devfreq profile |
| 127 | * @governor: method how to choose frequency based on the usage. |
Nishanth Menon | 1b5c1be | 2012-10-29 15:01:45 -0500 | [diff] [blame] | 128 | * @governor_name: devfreq governor name for use with this devfreq |
Nishanth Menon | e09651f | 2012-10-29 08:02:23 -0500 | [diff] [blame] | 129 | * @nb: notifier block used to notify devfreq object that it should |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 130 | * reevaluate operable frequencies. Devfreq users may use |
| 131 | * devfreq.nb to the corresponding register notifier call chain. |
Nishanth Menon | e09651f | 2012-10-29 08:02:23 -0500 | [diff] [blame] | 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 |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 135 | * touch this. |
Nishanth Menon | e09651f | 2012-10-29 08:02:23 -0500 | [diff] [blame] | 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. |
Jonghwa Lee | e552bba | 2012-08-23 20:00:46 +0900 | [diff] [blame] | 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 |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 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; |
Nishanth Menon | 1b5c1be | 2012-10-29 15:01:45 -0500 | [diff] [blame] | 159 | char governor_name[DEVFREQ_NAME_LEN]; |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 160 | struct notifier_block nb; |
Rajagopal Venkat | 7e6fdd4 | 2012-10-26 01:50:09 +0200 | [diff] [blame] | 161 | struct delayed_work work; |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 162 | |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 163 | unsigned long previous_freq; |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 164 | |
| 165 | void *data; /* private data for governors */ |
| 166 | |
MyungJoo Ham | 6530b9de | 2011-12-09 16:42:19 +0900 | [diff] [blame] | 167 | unsigned long min_freq; |
| 168 | unsigned long max_freq; |
Rajagopal Venkat | 7e6fdd4 | 2012-10-26 01:50:09 +0200 | [diff] [blame] | 169 | bool stop_polling; |
Jonghwa Lee | e552bba | 2012-08-23 20:00:46 +0900 | [diff] [blame] | 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; |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 176 | }; |
| 177 | |
| 178 | #if defined(CONFIG_PM_DEVFREQ) |
| 179 | extern struct devfreq *devfreq_add_device(struct device *dev, |
| 180 | struct devfreq_dev_profile *profile, |
Nishanth Menon | 1b5c1be | 2012-10-29 15:01:45 -0500 | [diff] [blame] | 181 | const char *governor_name, |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 182 | void *data); |
| 183 | extern int devfreq_remove_device(struct devfreq *devfreq); |
Rajagopal Venkat | 206c30c | 2012-10-26 01:50:18 +0200 | [diff] [blame] | 184 | extern int devfreq_suspend_device(struct devfreq *devfreq); |
| 185 | extern int devfreq_resume_device(struct devfreq *devfreq); |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 186 | |
| 187 | /* Helper functions for devfreq user device driver with OPP. */ |
| 188 | extern struct opp *devfreq_recommended_opp(struct device *dev, |
MyungJoo Ham | ab5f299 | 2012-03-16 21:54:53 +0100 | [diff] [blame] | 189 | unsigned long *freq, u32 flags); |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 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 | |
MyungJoo Ham | 883d588 | 2012-11-21 17:17:11 +0900 | [diff] [blame] | 195 | #if IS_ENABLED(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND) |
MyungJoo Ham | ce26c5b | 2011-10-02 00:19:34 +0200 | [diff] [blame] | 196 | /** |
| 197 | * struct devfreq_simple_ondemand_data - void *data fed to struct devfreq |
| 198 | * and devfreq_add_device |
Nishanth Menon | e09651f | 2012-10-29 08:02:23 -0500 | [diff] [blame] | 199 | * @upthreshold: If the load is over this value, the frequency jumps. |
MyungJoo Ham | ce26c5b | 2011-10-02 00:19:34 +0200 | [diff] [blame] | 200 | * Specify 0 to use the default. Valid value = 0 to 100. |
Nishanth Menon | e09651f | 2012-10-29 08:02:23 -0500 | [diff] [blame] | 201 | * @downdifferential: If the load is under upthreshold - downdifferential, |
MyungJoo Ham | ce26c5b | 2011-10-02 00:19:34 +0200 | [diff] [blame] | 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 | |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 215 | #else /* !CONFIG_PM_DEVFREQ */ |
| 216 | static struct devfreq *devfreq_add_device(struct device *dev, |
| 217 | struct devfreq_dev_profile *profile, |
Nishanth Menon | 1b5c1be | 2012-10-29 15:01:45 -0500 | [diff] [blame] | 218 | const char *governor_name, |
MyungJoo Ham | a95e1f5 | 2012-01-11 17:44:28 +0900 | [diff] [blame] | 219 | void *data) |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 220 | { |
| 221 | return NULL; |
| 222 | } |
| 223 | |
MyungJoo Ham | a95e1f5 | 2012-01-11 17:44:28 +0900 | [diff] [blame] | 224 | static int devfreq_remove_device(struct devfreq *devfreq) |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 225 | { |
| 226 | return 0; |
| 227 | } |
| 228 | |
Rajagopal Venkat | 206c30c | 2012-10-26 01:50:18 +0200 | [diff] [blame] | 229 | static int devfreq_suspend_device(struct devfreq *devfreq) |
| 230 | { |
| 231 | return 0; |
| 232 | } |
| 233 | |
| 234 | static int devfreq_resume_device(struct devfreq *devfreq) |
| 235 | { |
| 236 | return 0; |
| 237 | } |
| 238 | |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 239 | static struct opp *devfreq_recommended_opp(struct device *dev, |
MyungJoo Ham | ab5f299 | 2012-03-16 21:54:53 +0100 | [diff] [blame] | 240 | unsigned long *freq, u32 flags) |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 241 | { |
| 242 | return -EINVAL; |
| 243 | } |
| 244 | |
| 245 | static int devfreq_register_opp_notifier(struct device *dev, |
| 246 | struct devfreq *devfreq) |
| 247 | { |
| 248 | return -EINVAL; |
| 249 | } |
| 250 | |
| 251 | static int devfreq_unregister_opp_notifier(struct device *dev, |
| 252 | struct devfreq *devfreq) |
| 253 | { |
| 254 | return -EINVAL; |
| 255 | } |
| 256 | |
MyungJoo Ham | a3c98b8 | 2011-10-02 00:19:15 +0200 | [diff] [blame] | 257 | #endif /* CONFIG_PM_DEVFREQ */ |
| 258 | |
| 259 | #endif /* __LINUX_DEVFREQ_H__ */ |