xref: /src/sys/dev/clock_subr.h

/*	$NetBSD: clock_subr.h,v 1.33 2025/09/09 14:52:10 christos Exp $	*/

/*-
 * Copyright (c) 1996, 2020 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Gordon W. Ross
 *
 * 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.
 * 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``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 FOUNDATION OR CONTRIBUTORS
 * 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 _DEV_CLOCK_SUBR_H_
#define _DEV_CLOCK_SUBR_H_

#include <sys/clock.h>
#include <sys/device_if.h>
#include <sys/stdbool.h>

/*
 * "POSIX time" to/from "YY/MM/DD/hh/mm/ss"
 */
struct clock_ymdhms {
	uint64_t dt_year;
	uint8_t dt_mon;
	uint8_t dt_day;
	uint8_t dt_wday;	/* Day of week */
	uint8_t dt_hour;
	uint8_t dt_min;
	uint8_t dt_sec;
};

time_t	clock_ymdhms_to_secs(struct clock_ymdhms *);
int	clock_secs_to_ymdhms(time_t, struct clock_ymdhms *);

/*
 * BCD to binary and binary to BCD.
 */
static __inline unsigned int
bcdtobin(unsigned int bcd)
{
        return ((bcd >> 4) & 0x0f) * 10 + (bcd & 0x0f);
}

static __inline unsigned int
bintobcd(unsigned int bin)
{
	return (((bin / 10) << 4) & 0xf0) | (bin % 10);
}

/*
 * Interface to time-of-day clock devices.
 *
 * todr_gettime: convert time-of-day clock into a `struct timeval'
 * todr_settime: set time-of-day clock from a `struct timeval'
 *
 * (this is probably not so useful:)
 * todr_setwen: provide a machine-dependent TOD clock write-enable callback
 *		function which takes one boolean argument:
 *			1 to enable writes; 0 to disable writes.
 */
struct timeval;
struct todr_chip_handle {
	device_t todr_dev;	/* Device backing the TOD clock */
	void	*todr_devaux;	/* Auxillary data (maybe) needed by device */
	time_t	todr_base_time;	/* Base time (e.g. rootfs time) */

	int	(*todr_gettime)(struct todr_chip_handle *, struct timeval *);
	int	(*todr_settime)(struct todr_chip_handle *, struct timeval *);
	int	(*todr_gettime_ymdhms)(struct todr_chip_handle *,
	    			struct clock_ymdhms *);
	int	(*todr_settime_ymdhms)(struct todr_chip_handle *,
	    			struct clock_ymdhms *);
	int	(*todr_setwen)(struct todr_chip_handle *, int);

};
typedef struct todr_chip_handle *todr_chip_handle_t;

void	todr_init(void);
void	todr_attach(todr_chip_handle_t);
void	todr_lock(void);
void	todr_unlock(void);
bool	todr_lock_owned(void);

void	todr_set_systime(time_t base);
void	todr_save_systime(void);

#endif /* _DEV_CLOCK_SUBR_H_ */