xref: /openbmc/u-boot/drivers/rtc/pcf8563.c (revision 8ee59472)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2001
4  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5  */
6 
7 /*
8  * Date & Time support for Philips PCF8563 RTC
9  */
10 
11 /* #define	DEBUG	*/
12 
13 #include <common.h>
14 #include <command.h>
15 #include <rtc.h>
16 #include <i2c.h>
17 
18 #if defined(CONFIG_CMD_DATE)
19 
20 static uchar rtc_read  (uchar reg);
21 static void  rtc_write (uchar reg, uchar val);
22 
23 /* ------------------------------------------------------------------------- */
24 
25 int rtc_get (struct rtc_time *tmp)
26 {
27 	int rel = 0;
28 	uchar sec, min, hour, mday, wday, mon_cent, year;
29 
30 	sec	= rtc_read (0x02);
31 	min	= rtc_read (0x03);
32 	hour	= rtc_read (0x04);
33 	mday	= rtc_read (0x05);
34 	wday	= rtc_read (0x06);
35 	mon_cent= rtc_read (0x07);
36 	year	= rtc_read (0x08);
37 
38 	debug ( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
39 		"hr: %02x min: %02x sec: %02x\n",
40 		year, mon_cent, mday, wday,
41 		hour, min, sec );
42 	debug ( "Alarms: wday: %02x day: %02x hour: %02x min: %02x\n",
43 		rtc_read (0x0C),
44 		rtc_read (0x0B),
45 		rtc_read (0x0A),
46 		rtc_read (0x09) );
47 
48 	if (sec & 0x80) {
49 		puts ("### Warning: RTC Low Voltage - date/time not reliable\n");
50 		rel = -1;
51 	}
52 
53 	tmp->tm_sec  = bcd2bin (sec  & 0x7F);
54 	tmp->tm_min  = bcd2bin (min  & 0x7F);
55 	tmp->tm_hour = bcd2bin (hour & 0x3F);
56 	tmp->tm_mday = bcd2bin (mday & 0x3F);
57 	tmp->tm_mon  = bcd2bin (mon_cent & 0x1F);
58 	tmp->tm_year = bcd2bin (year) + ((mon_cent & 0x80) ? 1900 : 2000);
59 	tmp->tm_wday = bcd2bin (wday & 0x07);
60 	tmp->tm_yday = 0;
61 	tmp->tm_isdst= 0;
62 
63 	debug ( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
64 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
65 		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
66 
67 	return rel;
68 }
69 
70 int rtc_set (struct rtc_time *tmp)
71 {
72 	uchar century;
73 
74 	debug ( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
75 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
76 		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
77 
78 	rtc_write (0x08, bin2bcd(tmp->tm_year % 100));
79 
80 	century = (tmp->tm_year >= 2000) ? 0 : 0x80;
81 	rtc_write (0x07, bin2bcd(tmp->tm_mon) | century);
82 
83 	rtc_write (0x06, bin2bcd(tmp->tm_wday));
84 	rtc_write (0x05, bin2bcd(tmp->tm_mday));
85 	rtc_write (0x04, bin2bcd(tmp->tm_hour));
86 	rtc_write (0x03, bin2bcd(tmp->tm_min ));
87 	rtc_write (0x02, bin2bcd(tmp->tm_sec ));
88 
89 	return 0;
90 }
91 
92 void rtc_reset (void)
93 {
94 	/* clear all control & status registers */
95 	rtc_write (0x00, 0x00);
96 	rtc_write (0x01, 0x00);
97 	rtc_write (0x0D, 0x00);
98 
99 	/* clear Voltage Low bit */
100 	rtc_write (0x02, rtc_read (0x02) & 0x7F);
101 
102 	/* reset all alarms */
103 	rtc_write (0x09, 0x00);
104 	rtc_write (0x0A, 0x00);
105 	rtc_write (0x0B, 0x00);
106 	rtc_write (0x0C, 0x00);
107 }
108 
109 /* ------------------------------------------------------------------------- */
110 
111 static uchar rtc_read (uchar reg)
112 {
113 	return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
114 }
115 
116 static void rtc_write (uchar reg, uchar val)
117 {
118 	i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
119 }
120 
121 #endif
122