devfreq-governor.h

  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
  9 */
 10
 11#ifndef __LINUX_DEVFREQ_DEVFREQ_H__
 12#define __LINUX_DEVFREQ_DEVFREQ_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_interval 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 * @event_handler:      Callback for devfreq core framework to notify events
 61 *                      to governors. Events include per device governor
 62 *                      init and exit, opp changes out of devfreq, suspend
 63 *                      and resume of per device devfreq during device idle.
 64 *
 65 * Note that the callbacks are called with devfreq->lock locked by devfreq.
 66 */
 67struct devfreq_governor {
 68	struct list_head node;
 69
 70	const char name[DEVFREQ_NAME_LEN];
 71	const u64 attrs;
 72	const u64 flags;
 73	int (*get_target_freq)(struct devfreq *this, unsigned long *freq);
 74	int (*event_handler)(struct devfreq *devfreq,
 75				unsigned int event, void *data);
 76};
 77
 78void devfreq_monitor_start(struct devfreq *devfreq);
 79void devfreq_monitor_stop(struct devfreq *devfreq);
 80void devfreq_monitor_suspend(struct devfreq *devfreq);
 81void devfreq_monitor_resume(struct devfreq *devfreq);
 82void devfreq_update_interval(struct devfreq *devfreq, unsigned int *delay);
 83
 84int devfreq_add_governor(struct devfreq_governor *governor);
 85int devfreq_remove_governor(struct devfreq_governor *governor);
 86
 87int devm_devfreq_add_governor(struct device *dev,
 88			      struct devfreq_governor *governor);
 89
 90int devfreq_update_status(struct devfreq *devfreq, unsigned long freq);
 91int devfreq_update_target(struct devfreq *devfreq, unsigned long freq);
 92void devfreq_get_freq_range(struct devfreq *devfreq, unsigned long *min_freq,
 93			    unsigned long *max_freq);
 94
 95static inline int devfreq_update_stats(struct devfreq *df)
 96{
 97	if (!df->profile->get_dev_status)
 98		return -EINVAL;
 99
100	return df->profile->get_dev_status(df->dev.parent, &df->last_status);
101}
102#endif /* __LINUX_DEVFREQ_DEVFREQ_H__ */