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rtc.c revision 1.5 
      1 /*      $NetBSD: rtc.c,v 1.5 2006/03/08 03:29:49 christos Exp $        */
      2 /*
      3  * Copyright (c) 1997 Rolf Grossmann
      4  * All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  * 3. All advertising materials mentioning features or use of this software
     15  *    must display the following acknowledgement:
     16  *      This product includes software developed by Rolf Grossmann.
     17  * 4. The name of the author may not be used to endorse or promote products
     18  *    derived from this software without specific prior written permission
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/param.h>
     33 #include <next68k/dev/clockreg.h>
     34 #include <machine/cpu.h>
     35 #include <stand.h>
     36 
     37 u_char rtc_read(u_char);
     38 void rtc_init(void);
     39 time_t getsecs(void);
     40 
     41 
     42 /* ### where shall I put this definition? */
     43 #define	DELAY(n)	{ register int N = (n); while (--N > 0); }
     44 
     45 static volatile u_int *scr2 = (u_int *)NEXT_P_SCR2_CON;
     46 static u_char new_clock;
     47 
     48 u_char
     49 rtc_read(u_char reg)
     50 {
     51 	int i;
     52 	u_int tmp;
     53 	u_char val;
     54 
     55 	*scr2 = (*scr2 & ~(SCR2_RTDATA | SCR2_RTCLK)) | SCR2_RTCE;
     56 	DELAY(1);
     57 
     58 	val = reg;
     59 	for (i=0; i<8; i++) {
     60 		tmp = *scr2 & ~(SCR2_RTDATA | SCR2_RTCLK);
     61 		if (val & 0x80)
     62 			tmp |= SCR2_RTDATA;
     63 
     64 		*scr2 = tmp;
     65 		DELAY(1);
     66 		*scr2 = tmp | SCR2_RTCLK;
     67 		DELAY(1);
     68 		*scr2 = tmp;
     69 		DELAY(1);
     70 
     71 		val <<= 1;
     72 	}
     73 
     74 	val = 0;			/* should be anyway */
     75 	for (i=0; i<8; i++) {
     76 		val <<= 1;
     77 
     78 		tmp = *scr2 & ~(SCR2_RTDATA | SCR2_RTCLK);
     79 
     80 		*scr2 = tmp | SCR2_RTCLK;
     81 		DELAY(1);
     82 		*scr2 = tmp;
     83 		DELAY(1);
     84 
     85 		if (*scr2 & SCR2_RTDATA)
     86 			val |= 1;
     87 	}
     88 
     89 	*scr2 &= ~(SCR2_RTDATA|SCR2_RTCLK|SCR2_RTCE);
     90 	DELAY(1);
     91 
     92 	return val;
     93 }
     94 
     95 void
     96 rtc_init(void)
     97 {
     98 	u_char val;
     99 
    100 	val = rtc_read(RTC_STATUS);
    101 	new_clock = (val & RTC_NEW_CLOCK) ? 1 : 0;
    102 }
    103 
    104 time_t
    105 getsecs(void)
    106 {
    107 	u_int secs;
    108 
    109 	if (new_clock) {
    110 		secs = rtc_read(RTC_CNTR0) << 24 |
    111 		       rtc_read(RTC_CNTR1) << 16 |
    112 		       rtc_read(RTC_CNTR2) << 8  |
    113 		       rtc_read(RTC_CNTR3);
    114 	} else {
    115 		u_char d,h,m,s;
    116 #define BCD_DECODE(x) (((x) >> 4) * 10 + ((x) & 0xf))
    117 
    118 		d = rtc_read(RTC_DAY);
    119 		h = rtc_read(RTC_HRS);
    120 		m = rtc_read(RTC_MIN);
    121 		s = rtc_read(RTC_SEC);
    122 		secs = BCD_DECODE(d) * (60*60*24) +
    123 		       BCD_DECODE(h) * (60*60) +
    124 		       BCD_DECODE(m) * 60 +
    125 		       BCD_DECODE(s);
    126 	}
    127 
    128 	return secs;
    129 }
    130