/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2010-2013 Alexander Motin <mav@FreeBSD.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer,
 *    without modification, immediately at the beginning of the file.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _SYS_TIMEEC_H_
#define _SYS_TIMEEC_H_

#ifndef _KERNEL
#error "no user-serviceable parts inside"
#endif

#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/queue.h>
#include <sys/time.h>

/*
 * `struct eventtimer' is the interface between the hardware which implements
 * a event timer and the MI code which uses this to receive time events.
 */

struct eventtimer;
typedef int et_start_t(struct eventtimer *et,
    sbintime_t first, sbintime_t period);
typedef int et_stop_t(struct eventtimer *et);
typedef void et_event_cb_t(struct eventtimer *et, void *arg);
typedef int et_deregister_cb_t(struct eventtimer *et, void *arg);

struct eventtimer {
        SLIST_ENTRY(eventtimer) et_all;
                /* Pointer to the next event timer. */
        const char              *et_name;
                /* Name of the event timer. */
        int                     et_flags;
                /* Set of capabilities flags: */
#define ET_FLAGS_PERIODIC       1
#define ET_FLAGS_ONESHOT        2
#define ET_FLAGS_PERCPU         4
#define ET_FLAGS_C3STOP         8
#define ET_FLAGS_POW2DIV        16
        int                     et_quality;
                /*
                 * Used to determine if this timecounter is better than
                 * another timecounter. Higher means better.
                 */
        int                     et_active;
        u_int64_t               et_frequency;
                /* Base frequency in Hz. */
        sbintime_t              et_min_period;
        sbintime_t              et_max_period;
        et_start_t              *et_start;
        et_stop_t               *et_stop;
        et_event_cb_t           *et_event_cb;
        et_deregister_cb_t      *et_deregister_cb;
        void                    *et_arg;
        void                    *et_priv;
        struct sysctl_oid       *et_sysctl;
                /* Pointer to the event timer's private parts. */
};

extern struct mtx       et_eventtimers_mtx;
#define ET_LOCK()       mtx_lock(&et_eventtimers_mtx)
#define ET_UNLOCK()     mtx_unlock(&et_eventtimers_mtx)

/* Driver API */
int     et_register(struct eventtimer *et);
int     et_deregister(struct eventtimer *et);
void    et_change_frequency(struct eventtimer *et, uint64_t newfreq);
/* Consumer API  */
struct eventtimer *et_find(const char *name, int check, int want);
int     et_init(struct eventtimer *et, et_event_cb_t *event,
    et_deregister_cb_t *deregister, void *arg);
int     et_start(struct eventtimer *et, sbintime_t first, sbintime_t period);
int     et_stop(struct eventtimer *et);
int     et_ban(struct eventtimer *et);
int     et_free(struct eventtimer *et);

#ifdef SYSCTL_DECL
SYSCTL_DECL(_kern_eventtimer);
#endif
#endif /* !_SYS_TIMETC_H_ */