xref: /openbmc/u-boot/drivers/rtc/mc146818.c (revision 53efa1f1)
1 /*
2  * (C) Copyright 2001
3  * Denis Peter MPL AG Switzerland. d.peter@mpl.ch
4  *
5  * See file CREDITS for list of people who contributed to this
6  * project.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of
11  * the License, or (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21  * MA 02111-1307 USA
22  */
23 
24 /*
25  * Date & Time support for the MC146818 (PIXX4) RTC
26  */
27 
28 /*#define	DEBUG*/
29 
30 #include <common.h>
31 #include <command.h>
32 #include <rtc.h>
33 
34 #if defined(CONFIG_CMD_DATE)
35 
36 static uchar rtc_read  (uchar reg);
37 static void  rtc_write (uchar reg, uchar val);
38 
39 #define RTC_PORT_MC146818	CONFIG_SYS_ISA_IO_BASE_ADDRESS +  0x70
40 #define RTC_SECONDS		0x00
41 #define RTC_SECONDS_ALARM	0x01
42 #define RTC_MINUTES		0x02
43 #define RTC_MINUTES_ALARM	0x03
44 #define RTC_HOURS		0x04
45 #define RTC_HOURS_ALARM		0x05
46 #define RTC_DAY_OF_WEEK		0x06
47 #define RTC_DATE_OF_MONTH	0x07
48 #define RTC_MONTH		0x08
49 #define RTC_YEAR		0x09
50 #define RTC_CONFIG_A		0x0A
51 #define RTC_CONFIG_B		0x0B
52 #define RTC_CONFIG_C		0x0C
53 #define RTC_CONFIG_D		0x0D
54 
55 
56 /* ------------------------------------------------------------------------- */
57 
58 int rtc_get (struct rtc_time *tmp)
59 {
60 	uchar sec, min, hour, mday, wday, mon, year;
61   /* here check if rtc can be accessed */
62 	while((rtc_read(RTC_CONFIG_A)&0x80)==0x80);
63 	sec	= rtc_read (RTC_SECONDS);
64 	min	= rtc_read (RTC_MINUTES);
65 	hour	= rtc_read (RTC_HOURS);
66 	mday	= rtc_read (RTC_DATE_OF_MONTH);
67 	wday	= rtc_read (RTC_DAY_OF_WEEK);
68 	mon	= rtc_read (RTC_MONTH);
69 	year	= rtc_read (RTC_YEAR);
70 #ifdef CONFIG_AMIGAONEG3SE
71 	wday -= 1; /* VIA 686 stores Sunday = 1, Monday = 2, ... */
72 #endif
73 #ifdef RTC_DEBUG
74 	printf ( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
75 		"hr: %02x min: %02x sec: %02x\n",
76 		year, mon, mday, wday,
77 		hour, min, sec );
78 	printf ( "Alarms: month: %02x hour: %02x min: %02x sec: %02x\n",
79 		rtc_read (RTC_CONFIG_D) & 0x3F,
80 		rtc_read (RTC_HOURS_ALARM),
81 		rtc_read (RTC_MINUTES_ALARM),
82 		rtc_read (RTC_SECONDS_ALARM) );
83 #endif
84 	tmp->tm_sec  = bcd2bin (sec  & 0x7F);
85 	tmp->tm_min  = bcd2bin (min  & 0x7F);
86 	tmp->tm_hour = bcd2bin (hour & 0x3F);
87 	tmp->tm_mday = bcd2bin (mday & 0x3F);
88 	tmp->tm_mon  = bcd2bin (mon & 0x1F);
89 	tmp->tm_year = bcd2bin (year);
90 	tmp->tm_wday = bcd2bin (wday & 0x07);
91 	if(tmp->tm_year<70)
92 		tmp->tm_year+=2000;
93 	else
94 		tmp->tm_year+=1900;
95 	tmp->tm_yday = 0;
96 	tmp->tm_isdst= 0;
97 #ifdef RTC_DEBUG
98 	printf ( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
99 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
100 		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
101 #endif
102 
103 	return 0;
104 }
105 
106 int rtc_set (struct rtc_time *tmp)
107 {
108 #ifdef RTC_DEBUG
109 	printf ( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
110 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
111 		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
112 #endif
113 	rtc_write(RTC_CONFIG_B,0x82); /* disables the RTC to update the regs */
114 
115 	rtc_write (RTC_YEAR, bin2bcd(tmp->tm_year % 100));
116 	rtc_write (RTC_MONTH, bin2bcd(tmp->tm_mon));
117 #ifdef CONFIG_AMIGAONEG3SE
118 	rtc_write (RTC_DAY_OF_WEEK, bin2bcd(tmp->tm_wday)+1);
119 #else
120 	rtc_write (RTC_DAY_OF_WEEK, bin2bcd(tmp->tm_wday));
121 #endif
122 	rtc_write (RTC_DATE_OF_MONTH, bin2bcd(tmp->tm_mday));
123 	rtc_write (RTC_HOURS, bin2bcd(tmp->tm_hour));
124 	rtc_write (RTC_MINUTES, bin2bcd(tmp->tm_min ));
125 	rtc_write (RTC_SECONDS, bin2bcd(tmp->tm_sec ));
126 	rtc_write(RTC_CONFIG_B,0x02); /* enables the RTC to update the regs */
127 
128 	return 0;
129 }
130 
131 void rtc_reset (void)
132 {
133 	rtc_write(RTC_CONFIG_B,0x82); /* disables the RTC to update the regs */
134 	rtc_write(RTC_CONFIG_A,0x20); /* Normal OP */
135 	rtc_write(RTC_CONFIG_B,0x00);
136 	rtc_write(RTC_CONFIG_B,0x00);
137 	rtc_write(RTC_CONFIG_B,0x02); /* enables the RTC to update the regs */
138 }
139 
140 /* ------------------------------------------------------------------------- */
141 
142 #ifdef CONFIG_SYS_RTC_REG_BASE_ADDR
143 /*
144  * use direct memory access
145  */
146 static uchar rtc_read (uchar reg)
147 {
148 	return(in8(CONFIG_SYS_RTC_REG_BASE_ADDR+reg));
149 }
150 
151 static void rtc_write (uchar reg, uchar val)
152 {
153 	out8(CONFIG_SYS_RTC_REG_BASE_ADDR+reg, val);
154 }
155 #else
156 static uchar rtc_read (uchar reg)
157 {
158 	out8(RTC_PORT_MC146818,reg);
159 	return(in8(RTC_PORT_MC146818+1));
160 }
161 
162 static void rtc_write (uchar reg, uchar val)
163 {
164 	out8(RTC_PORT_MC146818,reg);
165 	out8(RTC_PORT_MC146818+1,val);
166 }
167 #endif
168 
169 #endif
170