xref: /openbmc/u-boot/drivers/rtc/mc146818.c (revision a79854a9)
1 /*
2  * (C) Copyright 2001
3  * Denis Peter MPL AG Switzerland. d.peter@mpl.ch
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 /*
9  * Date & Time support for the MC146818 (PIXX4) RTC
10  */
11 
12 /*#define	DEBUG*/
13 
14 #include <common.h>
15 #include <command.h>
16 #include <rtc.h>
17 
18 #ifdef __I386__
19 #include <asm/io.h>
20 #define in8(p) inb(p)
21 #define out8(p, v) outb(v, p)
22 #endif
23 
24 #if defined(CONFIG_CMD_DATE)
25 
26 static uchar rtc_read  (uchar reg);
27 static void  rtc_write (uchar reg, uchar val);
28 
29 #define RTC_PORT_MC146818	CONFIG_SYS_ISA_IO_BASE_ADDRESS +  0x70
30 #define RTC_SECONDS		0x00
31 #define RTC_SECONDS_ALARM	0x01
32 #define RTC_MINUTES		0x02
33 #define RTC_MINUTES_ALARM	0x03
34 #define RTC_HOURS		0x04
35 #define RTC_HOURS_ALARM		0x05
36 #define RTC_DAY_OF_WEEK		0x06
37 #define RTC_DATE_OF_MONTH	0x07
38 #define RTC_MONTH		0x08
39 #define RTC_YEAR		0x09
40 #define RTC_CONFIG_A		0x0A
41 #define RTC_CONFIG_B		0x0B
42 #define RTC_CONFIG_C		0x0C
43 #define RTC_CONFIG_D		0x0D
44 
45 
46 /* ------------------------------------------------------------------------- */
47 
48 int rtc_get (struct rtc_time *tmp)
49 {
50 	uchar sec, min, hour, mday, wday, mon, year;
51   /* here check if rtc can be accessed */
52 	while((rtc_read(RTC_CONFIG_A)&0x80)==0x80);
53 	sec	= rtc_read (RTC_SECONDS);
54 	min	= rtc_read (RTC_MINUTES);
55 	hour	= rtc_read (RTC_HOURS);
56 	mday	= rtc_read (RTC_DATE_OF_MONTH);
57 	wday	= rtc_read (RTC_DAY_OF_WEEK);
58 	mon	= rtc_read (RTC_MONTH);
59 	year	= rtc_read (RTC_YEAR);
60 #ifdef RTC_DEBUG
61 	printf ( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
62 		"hr: %02x min: %02x sec: %02x\n",
63 		year, mon, mday, wday,
64 		hour, min, sec );
65 	printf ( "Alarms: month: %02x hour: %02x min: %02x sec: %02x\n",
66 		rtc_read (RTC_CONFIG_D) & 0x3F,
67 		rtc_read (RTC_HOURS_ALARM),
68 		rtc_read (RTC_MINUTES_ALARM),
69 		rtc_read (RTC_SECONDS_ALARM) );
70 #endif
71 	tmp->tm_sec  = bcd2bin (sec  & 0x7F);
72 	tmp->tm_min  = bcd2bin (min  & 0x7F);
73 	tmp->tm_hour = bcd2bin (hour & 0x3F);
74 	tmp->tm_mday = bcd2bin (mday & 0x3F);
75 	tmp->tm_mon  = bcd2bin (mon & 0x1F);
76 	tmp->tm_year = bcd2bin (year);
77 	tmp->tm_wday = bcd2bin (wday & 0x07);
78 	if(tmp->tm_year<70)
79 		tmp->tm_year+=2000;
80 	else
81 		tmp->tm_year+=1900;
82 	tmp->tm_yday = 0;
83 	tmp->tm_isdst= 0;
84 #ifdef RTC_DEBUG
85 	printf ( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
86 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
87 		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
88 #endif
89 
90 	return 0;
91 }
92 
93 int rtc_set (struct rtc_time *tmp)
94 {
95 #ifdef RTC_DEBUG
96 	printf ( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
97 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
98 		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
99 #endif
100 	rtc_write(RTC_CONFIG_B,0x82); /* disables the RTC to update the regs */
101 
102 	rtc_write (RTC_YEAR, bin2bcd(tmp->tm_year % 100));
103 	rtc_write (RTC_MONTH, bin2bcd(tmp->tm_mon));
104 	rtc_write (RTC_DAY_OF_WEEK, bin2bcd(tmp->tm_wday));
105 	rtc_write (RTC_DATE_OF_MONTH, bin2bcd(tmp->tm_mday));
106 	rtc_write (RTC_HOURS, bin2bcd(tmp->tm_hour));
107 	rtc_write (RTC_MINUTES, bin2bcd(tmp->tm_min ));
108 	rtc_write (RTC_SECONDS, bin2bcd(tmp->tm_sec ));
109 	rtc_write(RTC_CONFIG_B,0x02); /* enables the RTC to update the regs */
110 
111 	return 0;
112 }
113 
114 void rtc_reset (void)
115 {
116 	rtc_write(RTC_CONFIG_B,0x82); /* disables the RTC to update the regs */
117 	rtc_write(RTC_CONFIG_A,0x20); /* Normal OP */
118 	rtc_write(RTC_CONFIG_B,0x00);
119 	rtc_write(RTC_CONFIG_B,0x00);
120 	rtc_write(RTC_CONFIG_B,0x02); /* enables the RTC to update the regs */
121 }
122 
123 /* ------------------------------------------------------------------------- */
124 
125 #ifdef CONFIG_SYS_RTC_REG_BASE_ADDR
126 /*
127  * use direct memory access
128  */
129 static uchar rtc_read (uchar reg)
130 {
131 	return(in8(CONFIG_SYS_RTC_REG_BASE_ADDR+reg));
132 }
133 
134 static void rtc_write (uchar reg, uchar val)
135 {
136 	out8(CONFIG_SYS_RTC_REG_BASE_ADDR+reg, val);
137 }
138 #else
139 static uchar rtc_read (uchar reg)
140 {
141 	out8(RTC_PORT_MC146818,reg);
142 	return(in8(RTC_PORT_MC146818+1));
143 }
144 
145 static void rtc_write (uchar reg, uchar val)
146 {
147 	out8(RTC_PORT_MC146818,reg);
148 	out8(RTC_PORT_MC146818+1,val);
149 }
150 #endif
151 
152 #endif
153