/*      $NetBSD: rtc.c,v 1.13 2025/10/13 15:40:14 thorpej Exp $ */

/*-
 * Copyright (c) 2002 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by UCHIYAMA Yasushi.
 *
 * 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: rtc.c,v 1.13 2025/10/13 15:40:14 thorpej Exp $");

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <sys/systm.h>
#ifdef GPROF
#include <sys/gmon.h>
#endif

#include <dev/clock_subr.h>

#include <sh3/rtcreg.h>

#if defined(DEBUG) && !defined(RTC_DEBUG)
#define RTC_DEBUG
#endif


struct rtc_softc {
        device_t sc_dev;

        int sc_valid;
        struct todr_chip_handle sc_todr;
        u_int sc_year0;
};

static int      rtc_match(device_t, cfdata_t, void *);
static void     rtc_attach(device_t, device_t, void *);

CFATTACH_DECL_NEW(rtc, sizeof(struct rtc_softc),
    rtc_match, rtc_attach, NULL, NULL);


/* todr(9) methods */
static int rtc_gettime_ymdhms(todr_chip_handle_t, struct clock_ymdhms *);
static int rtc_settime_ymdhms(todr_chip_handle_t, struct clock_ymdhms *);

#ifndef SH3_RTC_BASEYEAR
#define SH3_RTC_BASEYEAR        1900
#endif

static int
rtc_match(device_t parent, cfdata_t cfp, void *aux)
{

        return 1;
}


static void
rtc_attach(device_t parent, device_t self, void *aux)
{
        struct rtc_softc *sc;
        uint8_t r;
#ifdef RTC_DEBUG
        char bits[128];
#endif

        aprint_naive("\n");
        aprint_normal("\n");

        sc = device_private(self);
        sc->sc_dev = self;

        r = _reg_read_1(SH_(RCR2));

#ifdef RTC_DEBUG
        snprintb(bits, sizeof(bits), SH_RCR2_BITS, r);
        aprint_debug_dev(sc->sc_dev, "RCR2=%s\n", bits);
#endif

        /* Was the clock running? */
        if ((r & (SH_RCR2_ENABLE | SH_RCR2_START)) == (SH_RCR2_ENABLE
                                                       | SH_RCR2_START))
                sc->sc_valid = 1;
        else {
                sc->sc_valid = 0;
                aprint_error_dev(sc->sc_dev, "WARNING: clock was stopped\n");
        }

        /* Disable carry and alarm interrupts */
        _reg_write_1(SH_(RCR1), 0);

        /* Clock runs, no periodic interrupts, no 30-sec adjustment */
        _reg_write_1(SH_(RCR2), SH_RCR2_ENABLE | SH_RCR2_START);

        sc->sc_todr.todr_dev = self;
        sc->sc_todr.todr_gettime_ymdhms = rtc_gettime_ymdhms;
        sc->sc_todr.todr_settime_ymdhms = rtc_settime_ymdhms;

        sc->sc_year0 = device_getprop_uint_default(self, "start-year",
            SH3_RTC_BASEYEAR);
        aprint_debug_dev(self, "using start-year %u\n", sc->sc_year0);

        todr_attach(&sc->sc_todr);

#ifdef RTC_DEBUG
        {
                struct clock_ymdhms dt;
                rtc_gettime_ymdhms(&sc->sc_todr, &dt);
        }
#endif

        if (!pmf_device_register(self, NULL, NULL))
                aprint_error_dev(self, "unable to establish power handler\n");
}


static int
rtc_gettime_ymdhms(todr_chip_handle_t h, struct clock_ymdhms *dt)
{
        struct rtc_softc *sc = device_private(h->todr_dev);
        unsigned int year;
        int retry = 8;

        if (!sc->sc_valid) {
#ifdef RTC_DEBUG
                aprint_debug_dev(sc->sc_dev, "gettime: not valid\n");
                /* but proceed and read/print it anyway */
#else
                return EIO;
#endif
        }

        /* disable carry interrupt */
        _reg_bclr_1(SH_(RCR1), SH_RCR1_CIE);

        do {
                uint8_t r = _reg_read_1(SH_(RCR1));
                r &= ~SH_RCR1_CF;
                r |= SH_RCR1_AF; /* don't clear alarm flag */
                _reg_write_1(SH_(RCR1), r);

                if (CPU_IS_SH3)
                        year = _reg_read_1(SH3_RYRCNT);
                else
                        year = _reg_read_2(SH4_RYRCNT) & 0x00ff;
                dt->dt_year = bcdtobin(year);

                /* read counter */
#define RTCGET(x, y) \
                dt->dt_ ## x = bcdtobin(_reg_read_1(SH_(R ## y ## CNT)))

                RTCGET(mon, MON);
                RTCGET(wday, WK);
                RTCGET(day, DAY);
                RTCGET(hour, HR);
                RTCGET(min, MIN);
                RTCGET(sec, SEC);
#undef RTCGET
        } while ((_reg_read_1(SH_(RCR1)) & SH_RCR1_CF) && --retry > 0);

        if (retry == 0) {
#ifdef RTC_DEBUG
                aprint_debug_dev(sc->sc_dev, "gettime: retry failed\n");
#endif
                return EIO;
        }

        dt->dt_year += sc->sc_year0;
        if (dt->dt_year < POSIX_BASE_YEAR)
                dt->dt_year += 100;

#ifdef RTC_DEBUG
        aprint_debug_dev(sc->sc_dev,
                         "gettime: %04lu-%02d-%02d %02d:%02d:%02d\n",
                         (unsigned long)dt->dt_year, dt->dt_mon, dt->dt_day,
                         dt->dt_hour, dt->dt_min, dt->dt_sec);

        if (!sc->sc_valid)
                return EIO;
#endif

        return 0;
}


static int
rtc_settime_ymdhms(todr_chip_handle_t h, struct clock_ymdhms *dt)
{
        struct rtc_softc *sc = device_private(h->todr_dev);
        unsigned int year;
        uint8_t r;

        year = dt->dt_year - sc->sc_year0;
        if (year > 99)
                year -= 100;

        year = bintobcd(year);

        r = _reg_read_1(SH_(RCR2));

        /* stop clock */
        _reg_write_1(SH_(RCR2), (r & ~SH_RCR2_START) | SH_RCR2_RESET);

        /* set time */
        if (CPU_IS_SH3)
                _reg_write_1(SH3_RYRCNT, year);
        else
                _reg_write_2(SH4_RYRCNT, year);

#define RTCSET(x, y) \
        _reg_write_1(SH_(R ## x ## CNT), bintobcd(dt->dt_ ## y))

        RTCSET(MON, mon);
        RTCSET(WK, wday);
        RTCSET(DAY, day);
        RTCSET(HR, hour);
        RTCSET(MIN, min);
        RTCSET(SEC, sec);

#undef RTCSET

        /* start clock */
        _reg_write_1(SH_(RCR2), r);
        sc->sc_valid = 1;

#ifdef RTC_DEBUG
        aprint_debug_dev(sc->sc_dev,
                         "settime: %04lu-%02d-%02d %02d:%02d:%02d\n",
                         (unsigned long)dt->dt_year, dt->dt_mon, dt->dt_day,
                         dt->dt_hour, dt->dt_min, dt->dt_sec);
#endif

        return 0;
}