xref: /openbmc/u-boot/drivers/rtc/pcf8563.c (revision 33620947)
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 static uchar rtc_read  (uchar reg);
19 static void  rtc_write (uchar reg, uchar val);
20 
21 /* ------------------------------------------------------------------------- */
22 
23 int rtc_get (struct rtc_time *tmp)
24 {
25 	int rel = 0;
26 	uchar sec, min, hour, mday, wday, mon_cent, year;
27 
28 	sec	= rtc_read (0x02);
29 	min	= rtc_read (0x03);
30 	hour	= rtc_read (0x04);
31 	mday	= rtc_read (0x05);
32 	wday	= rtc_read (0x06);
33 	mon_cent= rtc_read (0x07);
34 	year	= rtc_read (0x08);
35 
36 	debug ( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
37 		"hr: %02x min: %02x sec: %02x\n",
38 		year, mon_cent, mday, wday,
39 		hour, min, sec );
40 	debug ( "Alarms: wday: %02x day: %02x hour: %02x min: %02x\n",
41 		rtc_read (0x0C),
42 		rtc_read (0x0B),
43 		rtc_read (0x0A),
44 		rtc_read (0x09) );
45 
46 	if (sec & 0x80) {
47 		puts ("### Warning: RTC Low Voltage - date/time not reliable\n");
48 		rel = -1;
49 	}
50 
51 	tmp->tm_sec  = bcd2bin (sec  & 0x7F);
52 	tmp->tm_min  = bcd2bin (min  & 0x7F);
53 	tmp->tm_hour = bcd2bin (hour & 0x3F);
54 	tmp->tm_mday = bcd2bin (mday & 0x3F);
55 	tmp->tm_mon  = bcd2bin (mon_cent & 0x1F);
56 	tmp->tm_year = bcd2bin (year) + ((mon_cent & 0x80) ? 1900 : 2000);
57 	tmp->tm_wday = bcd2bin (wday & 0x07);
58 	tmp->tm_yday = 0;
59 	tmp->tm_isdst= 0;
60 
61 	debug ( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
62 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
63 		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
64 
65 	return rel;
66 }
67 
68 int rtc_set (struct rtc_time *tmp)
69 {
70 	uchar century;
71 
72 	debug ( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
73 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
74 		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
75 
76 	rtc_write (0x08, bin2bcd(tmp->tm_year % 100));
77 
78 	century = (tmp->tm_year >= 2000) ? 0 : 0x80;
79 	rtc_write (0x07, bin2bcd(tmp->tm_mon) | century);
80 
81 	rtc_write (0x06, bin2bcd(tmp->tm_wday));
82 	rtc_write (0x05, bin2bcd(tmp->tm_mday));
83 	rtc_write (0x04, bin2bcd(tmp->tm_hour));
84 	rtc_write (0x03, bin2bcd(tmp->tm_min ));
85 	rtc_write (0x02, bin2bcd(tmp->tm_sec ));
86 
87 	return 0;
88 }
89 
90 void rtc_reset (void)
91 {
92 	/* clear all control & status registers */
93 	rtc_write (0x00, 0x00);
94 	rtc_write (0x01, 0x00);
95 	rtc_write (0x0D, 0x00);
96 
97 	/* clear Voltage Low bit */
98 	rtc_write (0x02, rtc_read (0x02) & 0x7F);
99 
100 	/* reset all alarms */
101 	rtc_write (0x09, 0x00);
102 	rtc_write (0x0A, 0x00);
103 	rtc_write (0x0B, 0x00);
104 	rtc_write (0x0C, 0x00);
105 }
106 
107 /* ------------------------------------------------------------------------- */
108 
109 static uchar rtc_read (uchar reg)
110 {
111 	return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
112 }
113 
114 static void rtc_write (uchar reg, uchar val)
115 {
116 	i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
117 }
118