1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework 4 * for Non-CPU Devices. 5 * 6 * Copyright (C) 2011 Samsung Electronics 7 * MyungJoo Ham <myungjoo.ham@samsung.com> 8 */ 9 10 #ifndef __LINUX_DEVFREQ_H__ 11 #define __LINUX_DEVFREQ_H__ 12 13 #include <linux/device.h> 14 #include <linux/notifier.h> 15 #include <linux/pm_opp.h> 16 #include <linux/pm_qos.h> 17 18 /* DEVFREQ governor name */ 19 #define DEVFREQ_GOV_SIMPLE_ONDEMAND "simple_ondemand" 20 #define DEVFREQ_GOV_PERFORMANCE "performance" 21 #define DEVFREQ_GOV_POWERSAVE "powersave" 22 #define DEVFREQ_GOV_USERSPACE "userspace" 23 #define DEVFREQ_GOV_PASSIVE "passive" 24 25 /* DEVFREQ notifier interface */ 26 #define DEVFREQ_TRANSITION_NOTIFIER (0) 27 28 /* Transition notifiers of DEVFREQ_TRANSITION_NOTIFIER */ 29 #define DEVFREQ_PRECHANGE (0) 30 #define DEVFREQ_POSTCHANGE (1) 31 32 /* DEVFREQ work timers */ 33 enum devfreq_timer { 34 DEVFREQ_TIMER_DEFERRABLE = 0, 35 DEVFREQ_TIMER_DELAYED, 36 DEVFREQ_TIMER_NUM, 37 }; 38 39 struct devfreq; 40 struct devfreq_governor; 41 struct devfreq_cpu_data; 42 struct thermal_cooling_device; 43 44 /** 45 * struct devfreq_dev_status - Data given from devfreq user device to 46 * governors. Represents the performance 47 * statistics. 48 * @total_time: The total time represented by this instance of 49 * devfreq_dev_status 50 * @busy_time: The time that the device was working among the 51 * total_time. 52 * @current_frequency: The operating frequency. 53 * @private_data: An entry not specified by the devfreq framework. 54 * A device and a specific governor may have their 55 * own protocol with private_data. However, because 56 * this is governor-specific, a governor using this 57 * will be only compatible with devices aware of it. 58 */ 59 struct devfreq_dev_status { 60 /* both since the last measure */ 61 unsigned long total_time; 62 unsigned long busy_time; 63 unsigned long current_frequency; 64 void *private_data; 65 }; 66 67 /* 68 * The resulting frequency should be at most this. (this bound is the 69 * least upper bound; thus, the resulting freq should be lower or same) 70 * If the flag is not set, the resulting frequency should be at most the 71 * bound (greatest lower bound) 72 */ 73 #define DEVFREQ_FLAG_LEAST_UPPER_BOUND 0x1 74 75 /** 76 * struct devfreq_dev_profile - Devfreq's user device profile 77 * @initial_freq: The operating frequency when devfreq_add_device() is 78 * called. 79 * @polling_ms: The polling interval in ms. 0 disables polling. 80 * @timer: Timer type is either deferrable or delayed timer. 81 * @target: The device should set its operating frequency at 82 * freq or lowest-upper-than-freq value. If freq is 83 * higher than any operable frequency, set maximum. 84 * Before returning, target function should set 85 * freq at the current frequency. 86 * The "flags" parameter's possible values are 87 * explained above with "DEVFREQ_FLAG_*" macros. 88 * @get_dev_status: The device should provide the current performance 89 * status to devfreq. Governors are recommended not to 90 * use this directly. Instead, governors are recommended 91 * to use devfreq_update_stats() along with 92 * devfreq.last_status. 93 * @get_cur_freq: The device should provide the current frequency 94 * at which it is operating. 95 * @exit: An optional callback that is called when devfreq 96 * is removing the devfreq object due to error or 97 * from devfreq_remove_device() call. If the user 98 * has registered devfreq->nb at a notifier-head, 99 * this is the time to unregister it. 100 * @freq_table: Optional list of frequencies to support statistics 101 * and freq_table must be generated in ascending order. 102 * @max_state: The size of freq_table. 103 * 104 * @is_cooling_device: A self-explanatory boolean giving the device a 105 * cooling effect property. 106 */ 107 struct devfreq_dev_profile { 108 unsigned long initial_freq; 109 unsigned int polling_ms; 110 enum devfreq_timer timer; 111 112 int (*target)(struct device *dev, unsigned long *freq, u32 flags); 113 int (*get_dev_status)(struct device *dev, 114 struct devfreq_dev_status *stat); 115 int (*get_cur_freq)(struct device *dev, unsigned long *freq); 116 void (*exit)(struct device *dev); 117 118 unsigned long *freq_table; 119 unsigned int max_state; 120 121 bool is_cooling_device; 122 }; 123 124 /** 125 * struct devfreq_stats - Statistics of devfreq device behavior 126 * @total_trans: Number of devfreq transitions. 127 * @trans_table: Statistics of devfreq transitions. 128 * @time_in_state: Statistics of devfreq states. 129 * @last_update: The last time stats were updated. 130 */ 131 struct devfreq_stats { 132 unsigned int total_trans; 133 unsigned int *trans_table; 134 u64 *time_in_state; 135 u64 last_update; 136 }; 137 138 /** 139 * struct devfreq - Device devfreq structure 140 * @node: list node - contains the devices with devfreq that have been 141 * registered. 142 * @lock: a mutex to protect accessing devfreq. 143 * @dev: device registered by devfreq class. dev.parent is the device 144 * using devfreq. 145 * @profile: device-specific devfreq profile 146 * @governor: method how to choose frequency based on the usage. 147 * @opp_table: Reference to OPP table of dev.parent, if one exists. 148 * @nb: notifier block used to notify devfreq object that it should 149 * reevaluate operable frequencies. Devfreq users may use 150 * devfreq.nb to the corresponding register notifier call chain. 151 * @work: delayed work for load monitoring. 152 * @freq_table: current frequency table used by the devfreq driver. 153 * @max_state: count of entry present in the frequency table. 154 * @previous_freq: previously configured frequency value. 155 * @last_status: devfreq user device info, performance statistics 156 * @data: devfreq driver pass to governors, governor should not change it. 157 * @governor_data: private data for governors, devfreq core doesn't touch it. 158 * @user_min_freq_req: PM QoS minimum frequency request from user (via sysfs) 159 * @user_max_freq_req: PM QoS maximum frequency request from user (via sysfs) 160 * @scaling_min_freq: Limit minimum frequency requested by OPP interface 161 * @scaling_max_freq: Limit maximum frequency requested by OPP interface 162 * @stop_polling: devfreq polling status of a device. 163 * @suspend_freq: frequency of a device set during suspend phase. 164 * @resume_freq: frequency of a device set in resume phase. 165 * @suspend_count: suspend requests counter for a device. 166 * @stats: Statistics of devfreq device behavior 167 * @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier 168 * @cdev: Cooling device pointer if the devfreq has cooling property 169 * @nb_min: Notifier block for DEV_PM_QOS_MIN_FREQUENCY 170 * @nb_max: Notifier block for DEV_PM_QOS_MAX_FREQUENCY 171 * 172 * This structure stores the devfreq information for a given device. 173 * 174 * Note that when a governor accesses entries in struct devfreq in its 175 * functions except for the context of callbacks defined in struct 176 * devfreq_governor, the governor should protect its access with the 177 * struct mutex lock in struct devfreq. A governor may use this mutex 178 * to protect its own private data in ``void *data`` as well. 179 */ 180 struct devfreq { 181 struct list_head node; 182 183 struct mutex lock; 184 struct device dev; 185 struct devfreq_dev_profile *profile; 186 const struct devfreq_governor *governor; 187 struct opp_table *opp_table; 188 struct notifier_block nb; 189 struct delayed_work work; 190 191 unsigned long *freq_table; 192 unsigned int max_state; 193 194 unsigned long previous_freq; 195 struct devfreq_dev_status last_status; 196 197 void *data; 198 void *governor_data; 199 200 struct dev_pm_qos_request user_min_freq_req; 201 struct dev_pm_qos_request user_max_freq_req; 202 unsigned long scaling_min_freq; 203 unsigned long scaling_max_freq; 204 bool stop_polling; 205 206 unsigned long suspend_freq; 207 unsigned long resume_freq; 208 atomic_t suspend_count; 209 210 /* information for device frequency transitions */ 211 struct devfreq_stats stats; 212 213 struct srcu_notifier_head transition_notifier_list; 214 215 /* Pointer to the cooling device if used for thermal mitigation */ 216 struct thermal_cooling_device *cdev; 217 218 struct notifier_block nb_min; 219 struct notifier_block nb_max; 220 }; 221 222 struct devfreq_freqs { 223 unsigned long old; 224 unsigned long new; 225 }; 226 227 #if defined(CONFIG_PM_DEVFREQ) 228 struct devfreq *devfreq_add_device(struct device *dev, 229 struct devfreq_dev_profile *profile, 230 const char *governor_name, 231 void *data); 232 int devfreq_remove_device(struct devfreq *devfreq); 233 struct devfreq *devm_devfreq_add_device(struct device *dev, 234 struct devfreq_dev_profile *profile, 235 const char *governor_name, 236 void *data); 237 void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq); 238 239 /* Supposed to be called by PM callbacks */ 240 int devfreq_suspend_device(struct devfreq *devfreq); 241 int devfreq_resume_device(struct devfreq *devfreq); 242 243 void devfreq_suspend(void); 244 void devfreq_resume(void); 245 246 /* update_devfreq() - Reevaluate the device and configure frequency */ 247 int update_devfreq(struct devfreq *devfreq); 248 249 /* Helper functions for devfreq user device driver with OPP. */ 250 struct dev_pm_opp *devfreq_recommended_opp(struct device *dev, 251 unsigned long *freq, u32 flags); 252 int devfreq_register_opp_notifier(struct device *dev, 253 struct devfreq *devfreq); 254 int devfreq_unregister_opp_notifier(struct device *dev, 255 struct devfreq *devfreq); 256 int devm_devfreq_register_opp_notifier(struct device *dev, 257 struct devfreq *devfreq); 258 void devm_devfreq_unregister_opp_notifier(struct device *dev, 259 struct devfreq *devfreq); 260 int devfreq_register_notifier(struct devfreq *devfreq, 261 struct notifier_block *nb, 262 unsigned int list); 263 int devfreq_unregister_notifier(struct devfreq *devfreq, 264 struct notifier_block *nb, 265 unsigned int list); 266 int devm_devfreq_register_notifier(struct device *dev, 267 struct devfreq *devfreq, 268 struct notifier_block *nb, 269 unsigned int list); 270 void devm_devfreq_unregister_notifier(struct device *dev, 271 struct devfreq *devfreq, 272 struct notifier_block *nb, 273 unsigned int list); 274 struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node); 275 struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev, 276 const char *phandle_name, int index); 277 #endif /* CONFIG_PM_DEVFREQ */ 278 279 /** 280 * struct devfreq_simple_ondemand_data - ``void *data`` fed to struct devfreq 281 * and devfreq_add_device 282 * @upthreshold: If the load is over this value, the frequency jumps. 283 * Specify 0 to use the default. Valid value = 0 to 100. 284 * @downdifferential: If the load is under upthreshold - downdifferential, 285 * the governor may consider slowing the frequency down. 286 * Specify 0 to use the default. Valid value = 0 to 100. 287 * downdifferential < upthreshold must hold. 288 * 289 * If the fed devfreq_simple_ondemand_data pointer is NULL to the governor, 290 * the governor uses the default values. 291 */ 292 struct devfreq_simple_ondemand_data { 293 unsigned int upthreshold; 294 unsigned int downdifferential; 295 }; 296 297 enum devfreq_parent_dev_type { 298 DEVFREQ_PARENT_DEV, 299 CPUFREQ_PARENT_DEV, 300 }; 301 302 /** 303 * struct devfreq_passive_data - ``void *data`` fed to struct devfreq 304 * and devfreq_add_device 305 * @parent: the devfreq instance of parent device. 306 * @get_target_freq: Optional callback, Returns desired operating frequency 307 * for the device using passive governor. That is called 308 * when passive governor should decide the next frequency 309 * by using the new frequency of parent devfreq device 310 * using governors except for passive governor. 311 * If the devfreq device has the specific method to decide 312 * the next frequency, should use this callback. 313 * @parent_type: the parent type of the device. 314 * @this: the devfreq instance of own device. 315 * @nb: the notifier block for DEVFREQ_TRANSITION_NOTIFIER or 316 * CPUFREQ_TRANSITION_NOTIFIER list. 317 * @cpu_data_list: the list of cpu frequency data for all cpufreq_policy. 318 * 319 * The devfreq_passive_data have to set the devfreq instance of parent 320 * device with governors except for the passive governor. But, don't need to 321 * initialize the 'this' and 'nb' field because the devfreq core will handle 322 * them. 323 */ 324 struct devfreq_passive_data { 325 /* Should set the devfreq instance of parent device */ 326 struct devfreq *parent; 327 328 /* Optional callback to decide the next frequency of passvice device */ 329 int (*get_target_freq)(struct devfreq *this, unsigned long *freq); 330 331 /* Should set the type of parent device */ 332 enum devfreq_parent_dev_type parent_type; 333 334 /* For passive governor's internal use. Don't need to set them */ 335 struct devfreq *this; 336 struct notifier_block nb; 337 struct list_head cpu_data_list; 338 }; 339 340 #if !defined(CONFIG_PM_DEVFREQ) 341 static inline struct devfreq *devfreq_add_device(struct device *dev, 342 struct devfreq_dev_profile *profile, 343 const char *governor_name, 344 void *data) 345 { 346 return ERR_PTR(-ENOSYS); 347 } 348 349 static inline int devfreq_remove_device(struct devfreq *devfreq) 350 { 351 return 0; 352 } 353 354 static inline struct devfreq *devm_devfreq_add_device(struct device *dev, 355 struct devfreq_dev_profile *profile, 356 const char *governor_name, 357 void *data) 358 { 359 return ERR_PTR(-ENOSYS); 360 } 361 362 static inline void devm_devfreq_remove_device(struct device *dev, 363 struct devfreq *devfreq) 364 { 365 } 366 367 static inline int devfreq_suspend_device(struct devfreq *devfreq) 368 { 369 return 0; 370 } 371 372 static inline int devfreq_resume_device(struct devfreq *devfreq) 373 { 374 return 0; 375 } 376 377 static inline void devfreq_suspend(void) {} 378 static inline void devfreq_resume(void) {} 379 380 static inline struct dev_pm_opp *devfreq_recommended_opp(struct device *dev, 381 unsigned long *freq, u32 flags) 382 { 383 return ERR_PTR(-EINVAL); 384 } 385 386 static inline int devfreq_register_opp_notifier(struct device *dev, 387 struct devfreq *devfreq) 388 { 389 return -EINVAL; 390 } 391 392 static inline int devfreq_unregister_opp_notifier(struct device *dev, 393 struct devfreq *devfreq) 394 { 395 return -EINVAL; 396 } 397 398 static inline int devm_devfreq_register_opp_notifier(struct device *dev, 399 struct devfreq *devfreq) 400 { 401 return -EINVAL; 402 } 403 404 static inline void devm_devfreq_unregister_opp_notifier(struct device *dev, 405 struct devfreq *devfreq) 406 { 407 } 408 409 static inline int devfreq_register_notifier(struct devfreq *devfreq, 410 struct notifier_block *nb, 411 unsigned int list) 412 { 413 return 0; 414 } 415 416 static inline int devfreq_unregister_notifier(struct devfreq *devfreq, 417 struct notifier_block *nb, 418 unsigned int list) 419 { 420 return 0; 421 } 422 423 static inline int devm_devfreq_register_notifier(struct device *dev, 424 struct devfreq *devfreq, 425 struct notifier_block *nb, 426 unsigned int list) 427 { 428 return 0; 429 } 430 431 static inline void devm_devfreq_unregister_notifier(struct device *dev, 432 struct devfreq *devfreq, 433 struct notifier_block *nb, 434 unsigned int list) 435 { 436 } 437 438 static inline struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node) 439 { 440 return ERR_PTR(-ENODEV); 441 } 442 443 static inline struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev, 444 const char *phandle_name, int index) 445 { 446 return ERR_PTR(-ENODEV); 447 } 448 449 static inline int devfreq_update_stats(struct devfreq *df) 450 { 451 return -EINVAL; 452 } 453 #endif /* CONFIG_PM_DEVFREQ */ 454 455 #endif /* __LINUX_DEVFREQ_H__ */ 456