/*      $OpenBSD: mcclock.c,v 1.6 2025/06/28 16:04:09 miod Exp $        */
/*      $NetBSD: mcclock.c,v 1.4 1996/10/13 02:59:41 christos Exp $     */

/*
 * Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University.
 * All rights reserved.
 *
 * Author: Chris G. Demetriou
 *
 * Permission to use, copy, modify and distribute this software and
 * its documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie the
 * rights to redistribute these changes.
 */

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/device.h>

#include <alpha/alpha/clockvar.h>
#include <alpha/alpha/mcclockvar.h>
#include <dev/ic/mc146818reg.h>

struct cfdriver mcclock_cd = {
        NULL, "mcclock", DV_DULL,
};

void    mcclock_init(struct device *);
void    mcclock_get(struct device *, time_t, struct clocktime *);
void    mcclock_set(struct device *, struct clocktime *);

const struct clockfns mcclock_clockfns = {
        mcclock_init, mcclock_get, mcclock_set,
};

#define mc146818_write(dev, reg, datum)                                 \
            (*(dev)->sc_busfns->mc_bf_write)(dev, reg, datum)
#define mc146818_read(dev, reg)                                         \
            (*(dev)->sc_busfns->mc_bf_read)(dev, reg)

void
mcclock_attach(struct mcclock_softc *sc, const struct mcclock_busfns *busfns)
{

        printf(": mc146818 or compatible");

        sc->sc_busfns = busfns;

        /* Turn interrupts off, just in case. */
        mc146818_write(sc, MC_REGB, MC_REGB_BINARY | MC_REGB_24HR);

        clockattach(&sc->sc_dev, &mcclock_clockfns);
}

void
mcclock_init(struct device *dev)
{
        struct mcclock_softc *sc = (struct mcclock_softc *)dev;

        mc146818_write(sc, MC_REGA, MC_BASE_32_KHz | MC_RATE_1024_Hz);
        mc146818_write(sc, MC_REGB,
            MC_REGB_PIE | MC_REGB_SQWE | MC_REGB_BINARY | MC_REGB_24HR);
}

/*
 * Get the time of day, based on the clock's value and/or the base value.
 */
void
mcclock_get(struct device *dev, time_t base, struct clocktime *ct)
{
        struct mcclock_softc *sc = (struct mcclock_softc *)dev;
        mc_todregs regs;
        int s;

        s = splclock();
        MC146818_GETTOD(sc, &regs)
        splx(s);

        ct->sec = regs[MC_SEC];
        ct->min = regs[MC_MIN];
        ct->hour = regs[MC_HOUR];
        ct->dow = regs[MC_DOW];
        ct->day = regs[MC_DOM];
        ct->mon = regs[MC_MONTH];
        ct->year = regs[MC_YEAR];
}

/*
 * Reset the TODR based on the time value.
 */
void
mcclock_set(struct device *dev, struct clocktime *ct)
{
        struct mcclock_softc *sc = (struct mcclock_softc *)dev;
        mc_todregs regs;
        int s;

        s = splclock();
        MC146818_GETTOD(sc, &regs);
        splx(s);

        regs[MC_SEC] = ct->sec;
        regs[MC_MIN] = ct->min;
        regs[MC_HOUR] = ct->hour;
        regs[MC_DOW] = ct->dow;
        regs[MC_DOM] = ct->day;
        regs[MC_MONTH] = ct->mon;
        regs[MC_YEAR] = ct->year;

        s = splclock();
        MC146818_PUTTOD(sc, &regs);
        splx(s);
}