xref: /netbsd-src/sys/arch/next68k/stand/boot/rtc.c (revision 783bf7199cac9069640f0160391cee3cc6f37264)
1 /*      $NetBSD: rtc.c,v 1.8 2023/02/12 08:25:09 tsutsui 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 <lib/libsa/stand.h>
36 #include <lib/libsa/net.h>
37 
38 #include "samachdep.h"
39 
40 u_char rtc_read(u_char);
41 
42 static volatile u_int *scr2 = (u_int *)NEXT_P_SCR2_CON;
43 static u_char new_clock;
44 
45 u_char
rtc_read(u_char reg)46 rtc_read(u_char reg)
47 {
48 	int i;
49 	u_int tmp;
50 	u_char val;
51 
52 	*scr2 = (*scr2 & ~(SCR2_RTDATA | SCR2_RTCLK)) | SCR2_RTCE;
53 	DELAY(1);
54 
55 	val = reg;
56 	for (i=0; i<8; i++) {
57 		tmp = *scr2 & ~(SCR2_RTDATA | SCR2_RTCLK);
58 		if (val & 0x80)
59 			tmp |= SCR2_RTDATA;
60 
61 		*scr2 = tmp;
62 		DELAY(1);
63 		*scr2 = tmp | SCR2_RTCLK;
64 		DELAY(1);
65 		*scr2 = tmp;
66 		DELAY(1);
67 
68 		val <<= 1;
69 	}
70 
71 	val = 0;			/* should be anyway */
72 	for (i=0; i<8; i++) {
73 		val <<= 1;
74 
75 		tmp = *scr2 & ~(SCR2_RTDATA | SCR2_RTCLK);
76 
77 		*scr2 = tmp | SCR2_RTCLK;
78 		DELAY(1);
79 		*scr2 = tmp;
80 		DELAY(1);
81 
82 		if (*scr2 & SCR2_RTDATA)
83 			val |= 1;
84 	}
85 
86 	*scr2 &= ~(SCR2_RTDATA|SCR2_RTCLK|SCR2_RTCE);
87 	DELAY(1);
88 
89 	return val;
90 }
91 
92 void
rtc_init(void)93 rtc_init(void)
94 {
95 	u_char val;
96 
97 	val = rtc_read(RTC_STATUS);
98 	new_clock = (val & RTC_NEW_CLOCK) ? 1 : 0;
99 }
100 
101 satime_t
getsecs(void)102 getsecs(void)
103 {
104 	u_int secs;
105 
106 	if (new_clock) {
107 		secs = rtc_read(RTC_CNTR0) << 24 |
108 		       rtc_read(RTC_CNTR1) << 16 |
109 		       rtc_read(RTC_CNTR2) << 8  |
110 		       rtc_read(RTC_CNTR3);
111 	} else {
112 		u_char d,h,m,s;
113 #define BCD_DECODE(x) (((x) >> 4) * 10 + ((x) & 0xf))
114 
115 		d = rtc_read(RTC_DAY);
116 		h = rtc_read(RTC_HRS);
117 		m = rtc_read(RTC_MIN);
118 		s = rtc_read(RTC_SEC);
119 		secs = BCD_DECODE(d) * (60*60*24) +
120 		       BCD_DECODE(h) * (60*60) +
121 		       BCD_DECODE(m) * 60 +
122 		       BCD_DECODE(s);
123 	}
124 
125 	return secs;
126 }
127