xref: /openbmc/u-boot/drivers/rtc/pcf8563.c (revision 33b1d3f4)
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_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 int rtc_get (struct rtc_time *tmp)
45 {
46 	int rel = 0;
47 	uchar sec, min, hour, mday, wday, mon_cent, year;
48 
49 	sec	= rtc_read (0x02);
50 	min	= rtc_read (0x03);
51 	hour	= rtc_read (0x04);
52 	mday	= rtc_read (0x05);
53 	wday	= rtc_read (0x06);
54 	mon_cent= rtc_read (0x07);
55 	year	= rtc_read (0x08);
56 
57 	debug ( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
58 		"hr: %02x min: %02x sec: %02x\n",
59 		year, mon_cent, mday, wday,
60 		hour, min, sec );
61 	debug ( "Alarms: wday: %02x day: %02x hour: %02x min: %02x\n",
62 		rtc_read (0x0C),
63 		rtc_read (0x0B),
64 		rtc_read (0x0A),
65 		rtc_read (0x09) );
66 
67 	if (sec & 0x80) {
68 		puts ("### Warning: RTC Low Voltage - date/time not reliable\n");
69 		rel = -1;
70 	}
71 
72 	tmp->tm_sec  = bcd2bin (sec  & 0x7F);
73 	tmp->tm_min  = bcd2bin (min  & 0x7F);
74 	tmp->tm_hour = bcd2bin (hour & 0x3F);
75 	tmp->tm_mday = bcd2bin (mday & 0x3F);
76 	tmp->tm_mon  = bcd2bin (mon_cent & 0x1F);
77 	tmp->tm_year = bcd2bin (year) + ((mon_cent & 0x80) ? 2000 : 1900);
78 	tmp->tm_wday = bcd2bin (wday & 0x07);
79 	tmp->tm_yday = 0;
80 	tmp->tm_isdst= 0;
81 
82 	debug ( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
83 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
84 		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
85 
86 	return rel;
87 }
88 
89 int rtc_set (struct rtc_time *tmp)
90 {
91 	uchar century;
92 
93 	debug ( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
94 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
95 		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
96 
97 	rtc_write (0x08, bin2bcd(tmp->tm_year % 100));
98 
99 	century = (tmp->tm_year >= 2000) ? 0x80 : 0;
100 	rtc_write (0x07, bin2bcd(tmp->tm_mon) | century);
101 
102 	rtc_write (0x06, bin2bcd(tmp->tm_wday));
103 	rtc_write (0x05, bin2bcd(tmp->tm_mday));
104 	rtc_write (0x04, bin2bcd(tmp->tm_hour));
105 	rtc_write (0x03, bin2bcd(tmp->tm_min ));
106 	rtc_write (0x02, bin2bcd(tmp->tm_sec ));
107 
108 	return 0;
109 }
110 
111 void rtc_reset (void)
112 {
113 	/* clear all control & status registers */
114 	rtc_write (0x00, 0x00);
115 	rtc_write (0x01, 0x00);
116 	rtc_write (0x0D, 0x00);
117 
118 	/* clear Voltage Low bit */
119 	rtc_write (0x02, rtc_read (0x02) & 0x7F);
120 
121 	/* reset all alarms */
122 	rtc_write (0x09, 0x00);
123 	rtc_write (0x0A, 0x00);
124 	rtc_write (0x0B, 0x00);
125 	rtc_write (0x0C, 0x00);
126 }
127 
128 /* ------------------------------------------------------------------------- */
129 
130 static uchar rtc_read (uchar reg)
131 {
132 	return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
133 }
134 
135 static void rtc_write (uchar reg, uchar val)
136 {
137 	i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
138 }
139 
140 static unsigned bcd2bin (uchar n)
141 {
142 	return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
143 }
144 
145 static unsigned char bin2bcd (unsigned int n)
146 {
147 	return (((n / 10) << 4) | (n % 10));
148 }
149 
150 #endif
151