xref: /openbmc/u-boot/drivers/rtc/mc146818.c (revision 33b1d3f4)
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 static uchar bin2bcd   (unsigned int n);
39 static unsigned bcd2bin(uchar c);
40 
41 #define RTC_PORT_MC146818	CONFIG_SYS_ISA_IO_BASE_ADDRESS +  0x70
42 #define RTC_SECONDS		0x00
43 #define RTC_SECONDS_ALARM	0x01
44 #define RTC_MINUTES		0x02
45 #define RTC_MINUTES_ALARM	0x03
46 #define RTC_HOURS		0x04
47 #define RTC_HOURS_ALARM		0x05
48 #define RTC_DAY_OF_WEEK		0x06
49 #define RTC_DATE_OF_MONTH	0x07
50 #define RTC_MONTH		0x08
51 #define RTC_YEAR		0x09
52 #define RTC_CONFIG_A		0x0A
53 #define RTC_CONFIG_B		0x0B
54 #define RTC_CONFIG_C		0x0C
55 #define RTC_CONFIG_D		0x0D
56 
57 
58 /* ------------------------------------------------------------------------- */
59 
60 int rtc_get (struct rtc_time *tmp)
61 {
62 	uchar sec, min, hour, mday, wday, mon, year;
63   /* here check if rtc can be accessed */
64 	while((rtc_read(RTC_CONFIG_A)&0x80)==0x80);
65 	sec	= rtc_read (RTC_SECONDS);
66 	min	= rtc_read (RTC_MINUTES);
67 	hour	= rtc_read (RTC_HOURS);
68 	mday	= rtc_read (RTC_DATE_OF_MONTH);
69 	wday	= rtc_read (RTC_DAY_OF_WEEK);
70 	mon	= rtc_read (RTC_MONTH);
71 	year	= rtc_read (RTC_YEAR);
72 #ifdef CONFIG_AMIGAONEG3SE
73 	wday -= 1; /* VIA 686 stores Sunday = 1, Monday = 2, ... */
74 #endif
75 #ifdef RTC_DEBUG
76 	printf ( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
77 		"hr: %02x min: %02x sec: %02x\n",
78 		year, mon, mday, wday,
79 		hour, min, sec );
80 	printf ( "Alarms: month: %02x hour: %02x min: %02x sec: %02x\n",
81 		rtc_read (RTC_CONFIG_D) & 0x3F,
82 		rtc_read (RTC_HOURS_ALARM),
83 		rtc_read (RTC_MINUTES_ALARM),
84 		rtc_read (RTC_SECONDS_ALARM) );
85 #endif
86 	tmp->tm_sec  = bcd2bin (sec  & 0x7F);
87 	tmp->tm_min  = bcd2bin (min  & 0x7F);
88 	tmp->tm_hour = bcd2bin (hour & 0x3F);
89 	tmp->tm_mday = bcd2bin (mday & 0x3F);
90 	tmp->tm_mon  = bcd2bin (mon & 0x1F);
91 	tmp->tm_year = bcd2bin (year);
92 	tmp->tm_wday = bcd2bin (wday & 0x07);
93 	if(tmp->tm_year<70)
94 		tmp->tm_year+=2000;
95 	else
96 		tmp->tm_year+=1900;
97 	tmp->tm_yday = 0;
98 	tmp->tm_isdst= 0;
99 #ifdef RTC_DEBUG
100 	printf ( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
101 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
102 		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
103 #endif
104 
105 	return 0;
106 }
107 
108 int rtc_set (struct rtc_time *tmp)
109 {
110 #ifdef RTC_DEBUG
111 	printf ( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
112 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
113 		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
114 #endif
115 	rtc_write(RTC_CONFIG_B,0x82); /* disables the RTC to update the regs */
116 
117 	rtc_write (RTC_YEAR, bin2bcd(tmp->tm_year % 100));
118 	rtc_write (RTC_MONTH, bin2bcd(tmp->tm_mon));
119 #ifdef CONFIG_AMIGAONEG3SE
120 	rtc_write (RTC_DAY_OF_WEEK, bin2bcd(tmp->tm_wday)+1);
121 #else
122 	rtc_write (RTC_DAY_OF_WEEK, bin2bcd(tmp->tm_wday));
123 #endif
124 	rtc_write (RTC_DATE_OF_MONTH, bin2bcd(tmp->tm_mday));
125 	rtc_write (RTC_HOURS, bin2bcd(tmp->tm_hour));
126 	rtc_write (RTC_MINUTES, bin2bcd(tmp->tm_min ));
127 	rtc_write (RTC_SECONDS, bin2bcd(tmp->tm_sec ));
128 	rtc_write(RTC_CONFIG_B,0x02); /* enables the RTC to update the regs */
129 
130 	return 0;
131 }
132 
133 void rtc_reset (void)
134 {
135 	rtc_write(RTC_CONFIG_B,0x82); /* disables the RTC to update the regs */
136 	rtc_write(RTC_CONFIG_A,0x20); /* Normal OP */
137 	rtc_write(RTC_CONFIG_B,0x00);
138 	rtc_write(RTC_CONFIG_B,0x00);
139 	rtc_write(RTC_CONFIG_B,0x02); /* enables the RTC to update the regs */
140 }
141 
142 /* ------------------------------------------------------------------------- */
143 
144 #ifdef CONFIG_SYS_RTC_REG_BASE_ADDR
145 /*
146  * use direct memory access
147  */
148 static uchar rtc_read (uchar reg)
149 {
150 	return(in8(CONFIG_SYS_RTC_REG_BASE_ADDR+reg));
151 }
152 
153 static void rtc_write (uchar reg, uchar val)
154 {
155 	out8(CONFIG_SYS_RTC_REG_BASE_ADDR+reg, val);
156 }
157 #else
158 static uchar rtc_read (uchar reg)
159 {
160 	out8(RTC_PORT_MC146818,reg);
161 	return(in8(RTC_PORT_MC146818+1));
162 }
163 
164 static void rtc_write (uchar reg, uchar val)
165 {
166 	out8(RTC_PORT_MC146818,reg);
167 	out8(RTC_PORT_MC146818+1,val);
168 }
169 #endif
170 
171 static unsigned bcd2bin (uchar n)
172 {
173 	return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
174 }
175 
176 static unsigned char bin2bcd (unsigned int n)
177 {
178 	return (((n / 10) << 4) | (n % 10));
179 }
180 
181 #endif
182