/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * governor.h - internal header for devfreq governors.
 *
 * Copyright (C) 2011 Samsung Electronics
 *      MyungJoo Ham <myungjoo.ham@samsung.com>
 *
 * This header is for devfreq governors
 */

#ifndef __LINUX_DEVFREQ_DEVFREQ_H__
#define __LINUX_DEVFREQ_DEVFREQ_H__

#include <linux/devfreq.h>

#define DEVFREQ_NAME_LEN                        16

#define to_devfreq(DEV) container_of((DEV), struct devfreq, dev)

/* Devfreq events */
#define DEVFREQ_GOV_START                       0x1
#define DEVFREQ_GOV_STOP                        0x2
#define DEVFREQ_GOV_UPDATE_INTERVAL             0x3
#define DEVFREQ_GOV_SUSPEND                     0x4
#define DEVFREQ_GOV_RESUME                      0x5

#define DEVFREQ_MIN_FREQ                        0
#define DEVFREQ_MAX_FREQ                        ULONG_MAX

/*
 * Definition of the governor feature flags
 * - DEVFREQ_GOV_FLAG_IMMUTABLE
 *   : This governor is never changeable to other governors.
 * - DEVFREQ_GOV_FLAG_IRQ_DRIVEN
 *   : The devfreq won't schedule the work for this governor.
 */
#define DEVFREQ_GOV_FLAG_IMMUTABLE                      BIT(0)
#define DEVFREQ_GOV_FLAG_IRQ_DRIVEN                     BIT(1)

/*
 * Definition of governor attribute flags except for common sysfs attributes
 * - DEVFREQ_GOV_ATTR_POLLING_INTERVAL
 *   : Indicate polling_interval sysfs attribute
 * - DEVFREQ_GOV_ATTR_TIMER
 *   : Indicate timer sysfs attribute
 */
#define DEVFREQ_GOV_ATTR_POLLING_INTERVAL               BIT(0)
#define DEVFREQ_GOV_ATTR_TIMER                          BIT(1)

/**
 * struct devfreq_governor - Devfreq policy governor
 * @node:               list node - contains registered devfreq governors
 * @name:               Governor's name
 * @attrs:              Governor's sysfs attribute flags
 * @flags:              Governor's feature flags
 * @get_target_freq:    Returns desired operating frequency for the device.
 *                      Basically, get_target_freq will run
 *                      devfreq_dev_profile.get_dev_status() to get the
 *                      status of the device (load = busy_time / total_time).
 * @event_handler:      Callback for devfreq core framework to notify events
 *                      to governors. Events include per device governor
 *                      init and exit, opp changes out of devfreq, suspend
 *                      and resume of per device devfreq during device idle.
 *
 * Note that the callbacks are called with devfreq->lock locked by devfreq.
 */
struct devfreq_governor {
        struct list_head node;

        const char name[DEVFREQ_NAME_LEN];
        const u64 attrs;
        const u64 flags;
        int (*get_target_freq)(struct devfreq *this, unsigned long *freq);
        int (*event_handler)(struct devfreq *devfreq,
                                unsigned int event, void *data);
};

void devfreq_monitor_start(struct devfreq *devfreq);
void devfreq_monitor_stop(struct devfreq *devfreq);
void devfreq_monitor_suspend(struct devfreq *devfreq);
void devfreq_monitor_resume(struct devfreq *devfreq);
void devfreq_update_interval(struct devfreq *devfreq, unsigned int *delay);

int devfreq_add_governor(struct devfreq_governor *governor);
int devfreq_remove_governor(struct devfreq_governor *governor);

int devm_devfreq_add_governor(struct device *dev,
                              struct devfreq_governor *governor);

int devfreq_update_status(struct devfreq *devfreq, unsigned long freq);
int devfreq_update_target(struct devfreq *devfreq, unsigned long freq);
void devfreq_get_freq_range(struct devfreq *devfreq, unsigned long *min_freq,
                            unsigned long *max_freq);

static inline int devfreq_update_stats(struct devfreq *df)
{
        if (!df->profile->get_dev_status)
                return -EINVAL;

        return df->profile->get_dev_status(df->dev.parent, &df->last_status);
}
#endif /* __LINUX_DEVFREQ_DEVFREQ_H__ */