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 DEVFREQ_NAME_LEN 16 17 18 #define to_devfreq(DEV) container_of((DEV), struct devfreq, dev) 19 20 /* Devfreq events */ 21 #define DEVFREQ_GOV_START 0x1 22 #define DEVFREQ_GOV_STOP 0x2 23 #define DEVFREQ_GOV_UPDATE_INTERVAL 0x3 24 #define DEVFREQ_GOV_SUSPEND 0x4 25 #define DEVFREQ_GOV_RESUME 0x5 26 27 #define DEVFREQ_MIN_FREQ 0 28 #define DEVFREQ_MAX_FREQ ULONG_MAX 29 30 /* 31 * Definition of the governor feature flags 32 * - DEVFREQ_GOV_FLAG_IMMUTABLE 33 * : This governor is never changeable to other governors. 34 * - DEVFREQ_GOV_FLAG_IRQ_DRIVEN 35 * : The devfreq won't schedule the work for this governor. 36 */ 37 #define DEVFREQ_GOV_FLAG_IMMUTABLE BIT(0) 38 #define DEVFREQ_GOV_FLAG_IRQ_DRIVEN BIT(1) 39 40 /* 41 * Definition of governor attribute flags except for common sysfs attributes 42 * - DEVFREQ_GOV_ATTR_POLLING_INTERVAL 43 * : Indicate polling_interal sysfs attribute 44 * - DEVFREQ_GOV_ATTR_TIMER 45 * : Indicate timer sysfs attribute 46 */ 47 #define DEVFREQ_GOV_ATTR_POLLING_INTERVAL BIT(0) 48 #define DEVFREQ_GOV_ATTR_TIMER BIT(1) 49 50 /** 51 * struct devfreq_governor - Devfreq policy governor 52 * @node: list node - contains registered devfreq governors 53 * @name: Governor's name 54 * @attrs: Governor's sysfs attribute flags 55 * @flags: Governor's feature flags 56 * @get_target_freq: Returns desired operating frequency for the device. 57 * Basically, get_target_freq will run 58 * devfreq_dev_profile.get_dev_status() to get the 59 * status of the device (load = busy_time / total_time). 60 * If no_central_polling is set, this callback is called 61 * only with update_devfreq() notified by OPP. 62 * @event_handler: Callback for devfreq core framework to notify events 63 * to governors. Events include per device governor 64 * init and exit, opp changes out of devfreq, suspend 65 * and resume of per device devfreq during device idle. 66 * 67 * Note that the callbacks are called with devfreq->lock locked by devfreq. 68 */ 69 struct devfreq_governor { 70 struct list_head node; 71 72 const char name[DEVFREQ_NAME_LEN]; 73 const u64 attrs; 74 const u64 flags; 75 int (*get_target_freq)(struct devfreq *this, unsigned long *freq); 76 int (*event_handler)(struct devfreq *devfreq, 77 unsigned int event, void *data); 78 }; 79 80 void devfreq_monitor_start(struct devfreq *devfreq); 81 void devfreq_monitor_stop(struct devfreq *devfreq); 82 void devfreq_monitor_suspend(struct devfreq *devfreq); 83 void devfreq_monitor_resume(struct devfreq *devfreq); 84 void devfreq_update_interval(struct devfreq *devfreq, unsigned int *delay); 85 86 int devfreq_add_governor(struct devfreq_governor *governor); 87 int devfreq_remove_governor(struct devfreq_governor *governor); 88 89 int devfreq_update_status(struct devfreq *devfreq, unsigned long freq); 90 int devfreq_update_target(struct devfreq *devfreq, unsigned long freq); 91 92 static inline int devfreq_update_stats(struct devfreq *df) 93 { 94 return df->profile->get_dev_status(df->dev.parent, &df->last_status); 95 } 96 #endif /* _GOVERNOR_H */ 97