1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * governor.h - internal header for devfreq governors. 4 * 5 * Copyright (C) 2011 Samsung Electronics 6 * MyungJoo Ham <myungjoo.ham@samsung.com> 7 * 8 * This header is for devfreq governors in drivers/devfreq/ 9 */ 10 11 #ifndef _GOVERNOR_H 12 #define _GOVERNOR_H 13 14 #include <linux/devfreq.h> 15 16 #define to_devfreq(DEV) container_of((DEV), struct devfreq, dev) 17 18 /* Devfreq events */ 19 #define DEVFREQ_GOV_START 0x1 20 #define DEVFREQ_GOV_STOP 0x2 21 #define DEVFREQ_GOV_INTERVAL 0x3 22 #define DEVFREQ_GOV_SUSPEND 0x4 23 #define DEVFREQ_GOV_RESUME 0x5 24 25 #define DEVFREQ_MIN_FREQ 0 26 #define DEVFREQ_MAX_FREQ ULONG_MAX 27 28 /** 29 * struct devfreq_governor - Devfreq policy governor 30 * @node: list node - contains registered devfreq governors 31 * @name: Governor's name 32 * @immutable: Immutable flag for governor. If the value is 1, 33 * this govenror is never changeable to other governor. 34 * @get_target_freq: Returns desired operating frequency for the device. 35 * Basically, get_target_freq will run 36 * devfreq_dev_profile.get_dev_status() to get the 37 * status of the device (load = busy_time / total_time). 38 * If no_central_polling is set, this callback is called 39 * only with update_devfreq() notified by OPP. 40 * @event_handler: Callback for devfreq core framework to notify events 41 * to governors. Events include per device governor 42 * init and exit, opp changes out of devfreq, suspend 43 * and resume of per device devfreq during device idle. 44 * 45 * Note that the callbacks are called with devfreq->lock locked by devfreq. 46 */ 47 struct devfreq_governor { 48 struct list_head node; 49 50 const char name[DEVFREQ_NAME_LEN]; 51 const unsigned int immutable; 52 int (*get_target_freq)(struct devfreq *this, unsigned long *freq); 53 int (*event_handler)(struct devfreq *devfreq, 54 unsigned int event, void *data); 55 }; 56 57 extern void devfreq_monitor_start(struct devfreq *devfreq); 58 extern void devfreq_monitor_stop(struct devfreq *devfreq); 59 extern void devfreq_monitor_suspend(struct devfreq *devfreq); 60 extern void devfreq_monitor_resume(struct devfreq *devfreq); 61 extern void devfreq_interval_update(struct devfreq *devfreq, 62 unsigned int *delay); 63 64 extern int devfreq_add_governor(struct devfreq_governor *governor); 65 extern int devfreq_remove_governor(struct devfreq_governor *governor); 66 67 extern int devfreq_update_status(struct devfreq *devfreq, unsigned long freq); 68 69 static inline int devfreq_update_stats(struct devfreq *df) 70 { 71 return df->profile->get_dev_status(df->dev.parent, &df->last_status); 72 } 73 #endif /* _GOVERNOR_H */ 74