xref: /openbmc/u-boot/drivers/rtc/pcf8563.c (revision 1ac559d4)
1 /*
2  * (C) Copyright 2001
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
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 Philips PCF8563 RTC
26  */
27 
28 /* #define	DEBUG	*/
29 
30 #include <common.h>
31 #include <command.h>
32 #include <rtc.h>
33 #include <i2c.h>
34 
35 #if defined(CONFIG_RTC_PCF8563) && defined(CONFIG_CMD_DATE)
36 
37 static uchar rtc_read  (uchar reg);
38 static void  rtc_write (uchar reg, uchar val);
39 static uchar bin2bcd   (unsigned int n);
40 static unsigned bcd2bin(uchar c);
41 
42 /* ------------------------------------------------------------------------- */
43 
44 void rtc_get (struct rtc_time *tmp)
45 {
46 	uchar sec, min, hour, mday, wday, mon_cent, year;
47 
48 	sec	= rtc_read (0x02);
49 	min	= rtc_read (0x03);
50 	hour	= rtc_read (0x04);
51 	mday	= rtc_read (0x05);
52 	wday	= rtc_read (0x06);
53 	mon_cent= rtc_read (0x07);
54 	year	= rtc_read (0x08);
55 
56 	debug ( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
57 		"hr: %02x min: %02x sec: %02x\n",
58 		year, mon_cent, mday, wday,
59 		hour, min, sec );
60 	debug ( "Alarms: wday: %02x day: %02x hour: %02x min: %02x\n",
61 		rtc_read (0x0C),
62 		rtc_read (0x0B),
63 		rtc_read (0x0A),
64 		rtc_read (0x09) );
65 
66 	if (sec & 0x80) {
67 		puts ("### Warning: RTC Low Voltage - date/time not reliable\n");
68 	}
69 
70 	tmp->tm_sec  = bcd2bin (sec  & 0x7F);
71 	tmp->tm_min  = bcd2bin (min  & 0x7F);
72 	tmp->tm_hour = bcd2bin (hour & 0x3F);
73 	tmp->tm_mday = bcd2bin (mday & 0x3F);
74 	tmp->tm_mon  = bcd2bin (mon_cent & 0x1F);
75 	tmp->tm_year = bcd2bin (year) + ((mon_cent & 0x80) ? 2000 : 1900);
76 	tmp->tm_wday = bcd2bin (wday & 0x07);
77 	tmp->tm_yday = 0;
78 	tmp->tm_isdst= 0;
79 
80 	debug ( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
81 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
82 		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
83 }
84 
85 void rtc_set (struct rtc_time *tmp)
86 {
87 	uchar century;
88 
89 	debug ( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
90 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
91 		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
92 
93 	rtc_write (0x08, bin2bcd(tmp->tm_year % 100));
94 
95 	century = (tmp->tm_year >= 2000) ? 0x80 : 0;
96 	rtc_write (0x07, bin2bcd(tmp->tm_mon) | century);
97 
98 	rtc_write (0x06, bin2bcd(tmp->tm_wday));
99 	rtc_write (0x05, bin2bcd(tmp->tm_mday));
100 	rtc_write (0x04, bin2bcd(tmp->tm_hour));
101 	rtc_write (0x03, bin2bcd(tmp->tm_min ));
102 	rtc_write (0x02, bin2bcd(tmp->tm_sec ));
103 }
104 
105 void rtc_reset (void)
106 {
107 	/* clear all control & status registers */
108 	rtc_write (0x00, 0x00);
109 	rtc_write (0x01, 0x00);
110 	rtc_write (0x0D, 0x00);
111 
112 	/* clear Voltage Low bit */
113 	rtc_write (0x02, rtc_read (0x02) & 0x7F);
114 
115 	/* reset all alarms */
116 	rtc_write (0x09, 0x00);
117 	rtc_write (0x0A, 0x00);
118 	rtc_write (0x0B, 0x00);
119 	rtc_write (0x0C, 0x00);
120 }
121 
122 /* ------------------------------------------------------------------------- */
123 
124 static uchar rtc_read (uchar reg)
125 {
126 	return (i2c_reg_read (CFG_I2C_RTC_ADDR, reg));
127 }
128 
129 static void rtc_write (uchar reg, uchar val)
130 {
131 	i2c_reg_write (CFG_I2C_RTC_ADDR, reg, val);
132 }
133 
134 static unsigned bcd2bin (uchar n)
135 {
136 	return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
137 }
138 
139 static unsigned char bin2bcd (unsigned int n)
140 {
141 	return (((n / 10) << 4) | (n % 10));
142 }
143 
144 #endif
145