xref: /netbsd-src/sys/arch/next68k/stand/boot/rtc.c (revision bada23909e740596d0a3785a73bd3583a9807fb8)
1 /*      $NetBSD: rtc.c,v 1.1.1.1 1998/06/09 07:53:06 dbj 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 /* ### where shall I put this definition? */
38 #define	DELAY(n)	{ register int N = (n); while (--N > 0); }
39 
40 static volatile u_int *scr2 = (u_int *)NEXT_P_SCR2_CON;
41 static u_char new_clock;
42 
43 u_char
44 rtc_read(u_char reg)
45 {
46 	int i;
47 	u_int tmp;
48 	u_char val;
49 
50 	*scr2 = (*scr2 & ~(SCR2_RTDATA | SCR2_RTCLK)) | SCR2_RTCE;
51 	DELAY(1);
52 
53 	val = reg;
54 	for (i=0; i<8; i++) {
55 		tmp = *scr2 & ~(SCR2_RTDATA | SCR2_RTCLK);
56 		if (val & 0x80)
57 			tmp |= SCR2_RTDATA;
58 
59 		*scr2 = tmp;
60 		DELAY(1);
61 		*scr2 = tmp | SCR2_RTCLK;
62 		DELAY(1);
63 		*scr2 = tmp;
64 		DELAY(1);
65 
66 		val <<= 1;
67 	}
68 
69 	val = 0;			/* should be anyway */
70 	for (i=0; i<8; i++) {
71 		val <<= 1;
72 
73 		tmp = *scr2 & ~(SCR2_RTDATA | SCR2_RTCLK);
74 
75 		*scr2 = tmp | SCR2_RTCLK;
76 		DELAY(1);
77 		*scr2 = tmp;
78 		DELAY(1);
79 
80 		if (*scr2 & SCR2_RTDATA)
81 			val |= 1;
82 	}
83 
84 	*scr2 &= ~(SCR2_RTDATA|SCR2_RTCLK|SCR2_RTCE);
85 	DELAY(1);
86 
87 	return val;
88 }
89 
90 void
91 rtc_init(void)
92 {
93 	u_char val;
94 
95 	val = rtc_read(RTC_STATUS);
96 	new_clock = (val & RTC_NEW_CLOCK) ? 1 : 0;
97 }
98 
99 time_t
100 getsecs(void)
101 {
102 	u_int secs;
103 
104 	if (new_clock) {
105 		secs = rtc_read(RTC_CNTR3) << 24 |
106 		       rtc_read(RTC_CNTR2) << 16 |
107 		       rtc_read(RTC_CNTR1) << 8  |
108 		       rtc_read(RTC_CNTR0);
109 	} else {
110 		u_char d,h,m,s;
111 #define BCD_DECODE(x) (((x) >> 4) * 10 + ((x) & 0xf))
112 
113 		d = rtc_read(RTC_DAY);
114 		h = rtc_read(RTC_HRS);
115 		m = rtc_read(RTC_MIN);
116 		s = rtc_read(RTC_SEC);
117 		secs = BCD_DECODE(d) * (60*60*24) +
118 		       BCD_DECODE(h) * (60*60) +
119 		       BCD_DECODE(m) * 60 +
120 		       BCD_DECODE(s);
121 	}
122 
123 	return secs;
124 }
125