/*      $NetBSD: msm6242b.c,v 1.7 2025/09/07 21:45:16 thorpej Exp $ */

/*-
 * Copyright (c) 2012 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Radoslaw Kujawa.
 *
 * 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.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: msm6242b.c,v 1.7 2025/09/07 21:45:16 thorpej Exp $");

/* 
 * Driver for OKI MSM6242B Real Time Clock. Somewhat based on an ancient, amiga
 * specific a2kbbc driver (which was turned into frontend to this driver).
 */

#include <sys/param.h>
#include <sys/device.h>
#include <sys/bus.h>

#include <dev/clock_subr.h>

#include <dev/ic/msm6242bvar.h>
#include <dev/ic/msm6242breg.h>

/* #define MSM6242B_DEBUG 1 */

static int msm6242b_gettime_ymdhms(todr_chip_handle_t, struct clock_ymdhms *); 
int msm6242b_settime_ymdhms(todr_chip_handle_t, struct clock_ymdhms *);

bool msm6242b_hold(struct msm6242b_softc *sc);
void msm6242b_free(struct msm6242b_softc *sc);
static uint8_t msm6242b_read(struct msm6242b_softc *, uint8_t);
static void msm6242b_write(struct msm6242b_softc *, uint8_t, uint8_t);
static void msm6242b_set(struct msm6242b_softc *, uint8_t, uint8_t);
static void msm6242b_unset(struct msm6242b_softc *, uint8_t, uint8_t);

void
msm6242b_attach(struct msm6242b_softc *sc)
{
        struct clock_ymdhms dt;

        todr_chip_handle_t handle;
        aprint_normal(": OKI MSM6242B\n");

        handle = &sc->sc_handle;
        handle->todr_dev = sc->sc_dev;
        handle->todr_gettime_ymdhms = msm6242b_gettime_ymdhms;
        handle->todr_settime_ymdhms = msm6242b_settime_ymdhms;

        if (msm6242b_gettime_ymdhms(handle, &dt) != 0) {
                aprint_error_dev(sc->sc_dev, "RTC does not work correctly\n");
                return;
        }

#ifdef MSM6242B_DEBUG
        aprint_normal_dev(sc->sc_dev, "the time is %d %d %d %d %d %d\n",
            dt.dt_year, dt.dt_mon, dt.dt_day, dt.dt_hour, dt.dt_min, dt.dt_sec);
#endif /* MSM6242B_DEBUG */
        todr_attach(handle);
}

static int
msm6242b_gettime_ymdhms(todr_chip_handle_t handle, struct clock_ymdhms *dt)
{
        struct msm6242b_softc *sc = device_private(handle->todr_dev);
        
        /* XXX: splsched(); */

        if(!msm6242b_hold(sc))
                return (ENXIO);

        dt->dt_sec = msm6242b_read(sc, MSM6242B_10SECOND) * 10 +
            msm6242b_read(sc, MSM6242B_1SECOND);
        dt->dt_min = msm6242b_read(sc, MSM6242B_10MINUTE) * 10 +
            msm6242b_read(sc, MSM6242B_1MINUTE);
        dt->dt_hour = (msm6242b_read(sc, MSM6242B_10HOUR_PMAM) &
            MSM6242B_10HOUR_MASK) * 10 + msm6242b_read(sc, MSM6242B_1HOUR);
        dt->dt_day = msm6242b_read(sc, MSM6242B_10DAY) * 10 +
            msm6242b_read(sc, MSM6242B_1DAY);
        dt->dt_mon = msm6242b_read(sc, MSM6242B_10MONTH) * 10 +
            msm6242b_read(sc, MSM6242B_1MONTH);
        dt->dt_year = msm6242b_read(sc, MSM6242B_10YEAR) * 10 +
            msm6242b_read(sc, MSM6242B_1YEAR);
        dt->dt_wday = msm6242b_read(sc, MSM6242B_WEEK);

#ifdef MSM6242B_DEBUG
        aprint_normal_dev(sc->sc_dev, "the time is %d %d %d %d %d %d\n",
            dt->dt_year, dt->dt_mon, dt->dt_day, dt->dt_hour, dt->dt_min, dt->dt_sec);
#endif /* MSM6242B_DEBUG */

        /* handle 12h mode */
        if ((msm6242b_read(sc, MSM6242B_CONTROL_F) & 
            MSM6242B_CONTROL_F_24H) == 0) {
                if ((msm6242b_read(sc, MSM6242B_10HOUR_PMAM) & 
                    MSM6242B_PMAM_BIT) == 0 && dt->dt_hour == 12)
                        dt->dt_hour = 0;
                else if ((msm6242b_read(sc, MSM6242B_10HOUR_PMAM) & 
                    MSM6242B_PMAM_BIT) && dt->dt_hour != 12)
                        dt->dt_hour += 12;
        }

        msm6242b_free(sc);

        dt->dt_year += MSM6242B_BASE_YEAR;
        if (dt->dt_year < POSIX_BASE_YEAR)
                dt->dt_year += 100;

        if ((dt->dt_hour > 23) ||
            (dt->dt_day  > 31) ||
            (dt->dt_mon  > 12) ||
            (dt->dt_year > 2036))
                return (EINVAL);

        return 0; 
}

bool
msm6242b_hold(struct msm6242b_softc *sc)
{
        int try;

#define TRY_MAX 10
        for (try = 0; try < TRY_MAX; try++) {
                msm6242b_set(sc, MSM6242B_CONTROL_D, MSM6242B_CONTROL_D_HOLD);
                if (msm6242b_read(sc, MSM6242B_CONTROL_D) 
                    & MSM6242B_CONTROL_D_BUSY) {
#ifdef MSM6242B_DEBUG
                        aprint_normal_dev(sc->sc_dev, "gotta idle\n");
#endif /* MSM6242B_DEBUG */
                        msm6242b_unset(sc, MSM6242B_CONTROL_D, 
                            MSM6242B_CONTROL_D_HOLD);
                        delay(70);
                } else {
#ifdef MSM6242B_DEBUG
                        aprint_normal_dev(sc->sc_dev, "not busy\n");
#endif /* MSM6242B_DEBUG */
                        break;
                }
        }               

        if (try == TRY_MAX) {
                aprint_error_dev(sc->sc_dev, "can't hold the chip\n");
                return false;
        }
        return true;
}

void
msm6242b_free(struct msm6242b_softc *sc)
{
        msm6242b_unset(sc, MSM6242B_CONTROL_D, MSM6242B_CONTROL_D_HOLD);
}

static uint8_t
msm6242b_read(struct msm6242b_softc *sc, uint8_t reg)
{
        uint8_t r;
        r = bus_space_read_1(sc->sc_iot, sc->sc_ioh, reg) & MSM6242B_MASK;
        return r;
}

static void
msm6242b_write(struct msm6242b_softc *sc, uint8_t reg, uint8_t val)
{
        bus_space_write_1(sc->sc_iot, sc->sc_ioh, reg, val);
}

static void
msm6242b_set(struct msm6242b_softc *sc, uint8_t reg, uint8_t bits)
{
        uint8_t v;
        v = msm6242b_read(sc, reg) | bits;
        msm6242b_write(sc, reg, v);     
}

static void
msm6242b_unset(struct msm6242b_softc *sc, uint8_t reg, uint8_t bits)
{
        uint8_t v;
        v = msm6242b_read(sc, reg) & ~bits;
        msm6242b_write(sc, reg, v);
}

int 
msm6242b_settime_ymdhms(todr_chip_handle_t handle, struct clock_ymdhms *dt) 
{
        struct msm6242b_softc *sc = device_private(handle->todr_dev);
        int ampm;

        /* XXX: splsched(); */

        if(!msm6242b_hold(sc))
                return (ENXIO);

        ampm = 0;
        if ((msm6242b_read(sc, MSM6242B_CONTROL_F) & 
            MSM6242B_CONTROL_F_24H) == 0) {
                if (dt->dt_hour >= 12) { 
                        ampm = MSM6242B_CONTROL_F_24H;
                        if (dt->dt_hour != 12)
                                dt->dt_hour -= 12;
                } else if (dt->dt_hour == 0) { 
                        dt->dt_hour = 12;
                }
        }

        msm6242b_write(sc, MSM6242B_10HOUR_PMAM, (dt->dt_hour / 10) | ampm);
        msm6242b_write(sc, MSM6242B_1HOUR, dt->dt_hour % 10);
        msm6242b_write(sc, MSM6242B_10SECOND, dt->dt_sec / 10);
        msm6242b_write(sc, MSM6242B_1SECOND, dt->dt_sec % 10);
        msm6242b_write(sc, MSM6242B_10MINUTE, dt->dt_min / 10);
        msm6242b_write(sc, MSM6242B_1MINUTE, dt->dt_min % 10);
        msm6242b_write(sc, MSM6242B_10DAY, dt->dt_day / 10);
        msm6242b_write(sc, MSM6242B_1DAY, dt->dt_day % 10);
        msm6242b_write(sc, MSM6242B_10MONTH, dt->dt_mon / 10);
        msm6242b_write(sc, MSM6242B_1MONTH, dt->dt_mon % 10);
        msm6242b_write(sc, MSM6242B_10YEAR, (dt->dt_year / 10) % 10);
        msm6242b_write(sc, MSM6242B_1YEAR, dt->dt_year % 10);
        msm6242b_write(sc, MSM6242B_WEEK, dt->dt_wday);

        msm6242b_free(sc);

        return 0;
}