/*      $NetBSD: rtc.c,v 1.25 2025/09/07 21:45:13 thorpej Exp $ */

/*
 * Copyright (c) 1988 University of Utah.
 * Copyright (c) 1982, 1990, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * the Systems Programming Group of the University of Utah Computer
 * Science Department.
 *
 * 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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 * from: Utah $Hdr: clock.c 1.18 91/01/21$
 *
 *      @(#)clock.c     8.2 (Berkeley) 1/12/94
 */

/*
 * attachment for HP300 real-time clock (RTC)
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: rtc.c,v 1.25 2025/09/07 21:45:13 thorpej Exp $");

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

#include <hp300/dev/intiovar.h>
#include <hp300/dev/rtcreg.h>

#include <dev/clock_subr.h>

struct rtc_softc {
        device_t sc_dev;
        bus_space_tag_t sc_bst;
        bus_space_handle_t sc_bsh;
        struct todr_chip_handle sc_handle;
};

static int      rtcmatch(device_t, cfdata_t, void *);
static void     rtcattach(device_t, device_t, void *aux);

CFATTACH_DECL_NEW(rtc, sizeof(struct rtc_softc),
    rtcmatch, rtcattach, NULL, NULL);

static int      rtc_gettime_ymdhms(todr_chip_handle_t, struct clock_ymdhms *);
static int      rtc_settime_ymdhms(todr_chip_handle_t, struct clock_ymdhms *);
static uint8_t  rtc_readreg(struct rtc_softc *, int);
static uint8_t  rtc_writereg(struct rtc_softc *, int, uint8_t);


static int
rtcmatch(device_t parent, cfdata_t cf, void *aux)
{
        struct intio_attach_args *ia = aux;

        /* 425e doesn't have the traditional RTC at intio */
        if (machineid == HP_425 && mmuid == MMUID_425_E)
                return 0;

        if (strcmp("rtc", ia->ia_modname) != 0)
                return 0;

        return 1;
}

static void
rtcattach(device_t parent, device_t self, void *aux)
{
        struct rtc_softc *sc = device_private(self);
        struct intio_attach_args *ia = aux;
        struct todr_chip_handle *todr_handle;
        bus_space_tag_t bst = ia->ia_bst;

        sc->sc_dev = self;
        if (bus_space_map(bst, ia->ia_iobase, INTIO_DEVSIZE, 0,
            &sc->sc_bsh)) {
                aprint_error(": can't map registers\n");
                return;
        }

        aprint_normal("\n");

        sc->sc_bst = bst;

        todr_handle = &sc->sc_handle;
        todr_handle->todr_dev = self;
        todr_handle->todr_gettime_ymdhms = rtc_gettime_ymdhms;
        todr_handle->todr_settime_ymdhms = rtc_settime_ymdhms;

        todr_attach(todr_handle);
}

static int
rtc_gettime_ymdhms(todr_chip_handle_t handle, struct clock_ymdhms *dt)
{
        struct rtc_softc *sc = device_private(handle->todr_dev);
        int i, year;
        bool read_okay;
        uint8_t rtc_registers[NUM_RTC_REGS];

        /* read rtc registers */
        read_okay = false;
        while (!read_okay) {
                read_okay = true;
                for (i = 0; i < NUM_RTC_REGS; i++)
                        rtc_registers[i] = rtc_readreg(sc, i);
                for (i = 0; i < NUM_RTC_REGS; i++)
                        if (rtc_registers[i] != rtc_readreg(sc, i))
                                read_okay = false;
        }

#define rtc_to_decimal(a,b)     (rtc_registers[a] * 10 + rtc_registers[b])

        dt->dt_sec  = rtc_to_decimal(1, 0);
        dt->dt_min  = rtc_to_decimal(3, 2);
        dt->dt_hour = (rtc_registers[5] & RTC_REG5_HOUR) * 10 +
            rtc_registers[4];
        dt->dt_day  = rtc_to_decimal(8, 7);
        dt->dt_mon  = rtc_to_decimal(10, 9);

        year = rtc_to_decimal(12, 11) + RTC_BASE_YEAR;
        if (year < POSIX_BASE_YEAR)
                year += 100;
        dt->dt_year = year;

#undef  rtc_to_decimal

        return 0;
}

static int
rtc_settime_ymdhms(todr_chip_handle_t handle, struct clock_ymdhms *dt)
{
        struct rtc_softc *sc = device_private(handle->todr_dev);
        int i, year;
        uint8_t rtc_registers[NUM_RTC_REGS];

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

#define decimal_to_rtc(a,b,n)           \
        rtc_registers[a] = (n) % 10;    \
        rtc_registers[b] = (n) / 10;

        decimal_to_rtc(0, 1, dt->dt_sec);
        decimal_to_rtc(2, 3, dt->dt_min);
        decimal_to_rtc(7, 8, dt->dt_day);
        decimal_to_rtc(9, 10, dt->dt_mon);
        decimal_to_rtc(11, 12, year);

        rtc_registers[4] = dt->dt_hour % 10;
        rtc_registers[5] = ((dt->dt_hour / 10) & RTC_REG5_HOUR) | RTC_REG5_24HR;

        rtc_registers[6] = 0;

#undef  decimal_to_rtc

        /* write rtc registers */
        rtc_writereg(sc, 15, 13);       /* reset prescalar */
        for (i = 0; i < NUM_RTC_REGS; i++)
                if (rtc_registers[i] !=
                    rtc_writereg(sc, i, rtc_registers[i]))
                        return 1;
        return 0;
}

static uint8_t
rtc_readreg(struct rtc_softc *sc, int reg)
{
        bus_space_tag_t bst = sc->sc_bst;
        bus_space_handle_t bsh = sc->sc_bsh;
        uint8_t data;
        int s = splvm();

        data = reg;
        intio_device_writecmd(bst, bsh, RTC_SET_REG, &data, 1);
        intio_device_readcmd(bst, bsh, RTC_READ_REG, &data);

        splx(s);
        return data;
}

static uint8_t
rtc_writereg(struct rtc_softc *sc, int reg, uint8_t data)
{
        bus_space_tag_t bst = sc->sc_bst;
        bus_space_handle_t bsh = sc->sc_bsh;
        uint8_t tmp;
        int s = splvm();

        tmp = (data << 4) | reg;
        intio_device_writecmd(bst, bsh, RTC_SET_REG, &tmp, 1);
        intio_device_writecmd(bst, bsh, RTC_WRITE_REG, NULL, 0);
        intio_device_readcmd(bst, bsh, RTC_READ_REG, &tmp);

        splx(s);
        return tmp;
}