/*      $NetBSD: rtc.c,v 1.8 2023/02/12 08:25:09 tsutsui Exp $        */
/*
* Copyright (c) 1997 Rolf Grossmann
* All rights reserved.
*
* 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. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*      This product includes software developed by Rolf Grossmann.
* 4. The name of the author may not be used to endorse or promote products
*    derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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/param.h>
#include <next68k/dev/clockreg.h>
#include <machine/cpu.h>
#include <lib/libsa/stand.h>
#include <lib/libsa/net.h>

#include "samachdep.h"

u_char rtc_read(u_char);

static volatile u_int *scr2 = (u_int *)NEXT_P_SCR2_CON;
static u_char new_clock;

u_char
rtc_read(u_char reg)
{
       int i;
       u_int tmp;
       u_char val;

       *scr2 = (*scr2 & ~(SCR2_RTDATA | SCR2_RTCLK)) | SCR2_RTCE;
       DELAY(1);

       val = reg;
       for (i=0; i<8; i++) {
               tmp = *scr2 & ~(SCR2_RTDATA | SCR2_RTCLK);
               if (val & 0x80)
                       tmp |= SCR2_RTDATA;

               *scr2 = tmp;
               DELAY(1);
               *scr2 = tmp | SCR2_RTCLK;
               DELAY(1);
               *scr2 = tmp;
               DELAY(1);

               val <<= 1;
       }

       val = 0;                        /* should be anyway */
       for (i=0; i<8; i++) {
               val <<= 1;

               tmp = *scr2 & ~(SCR2_RTDATA | SCR2_RTCLK);

               *scr2 = tmp | SCR2_RTCLK;
               DELAY(1);
               *scr2 = tmp;
               DELAY(1);

               if (*scr2 & SCR2_RTDATA)
                       val |= 1;
       }

       *scr2 &= ~(SCR2_RTDATA|SCR2_RTCLK|SCR2_RTCE);
       DELAY(1);

       return val;
}

void
rtc_init(void)
{
       u_char val;

       val = rtc_read(RTC_STATUS);
       new_clock = (val & RTC_NEW_CLOCK) ? 1 : 0;
}

satime_t
getsecs(void)
{
       u_int secs;

       if (new_clock) {
               secs = rtc_read(RTC_CNTR0) << 24 |
                      rtc_read(RTC_CNTR1) << 16 |
                      rtc_read(RTC_CNTR2) << 8  |
                      rtc_read(RTC_CNTR3);
       } else {
               u_char d,h,m,s;
#define BCD_DECODE(x) (((x) >> 4) * 10 + ((x) & 0xf))

               d = rtc_read(RTC_DAY);
               h = rtc_read(RTC_HRS);
               m = rtc_read(RTC_MIN);
               s = rtc_read(RTC_SEC);
               secs = BCD_DECODE(d) * (60*60*24) +
                      BCD_DECODE(h) * (60*60) +
                      BCD_DECODE(m) * 60 +
                      BCD_DECODE(s);
       }

       return secs;
}