1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2001
4 * ARIO Data Networks, Inc. dchiu@ariodata.com
5 *
6 * Based on MontaVista DS1743 code and U-Boot mc146818 code
7 */
8
9 /*
10 * Date & Time support for the DS174x RTC
11 */
12
13 /*#define DEBUG*/
14
15 #include <common.h>
16 #include <command.h>
17 #include <rtc.h>
18
19 #if defined(CONFIG_CMD_DATE)
20
21 static uchar rtc_read( unsigned int addr );
22 static void rtc_write( unsigned int addr, uchar val);
23
24 #define RTC_BASE ( CONFIG_SYS_NVRAM_SIZE + CONFIG_SYS_NVRAM_BASE_ADDR )
25
26 #define RTC_YEAR ( RTC_BASE + 7 )
27 #define RTC_MONTH ( RTC_BASE + 6 )
28 #define RTC_DAY_OF_MONTH ( RTC_BASE + 5 )
29 #define RTC_DAY_OF_WEEK ( RTC_BASE + 4 )
30 #define RTC_HOURS ( RTC_BASE + 3 )
31 #define RTC_MINUTES ( RTC_BASE + 2 )
32 #define RTC_SECONDS ( RTC_BASE + 1 )
33 #define RTC_CENTURY ( RTC_BASE + 0 )
34
35 #define RTC_CONTROLA RTC_CENTURY
36 #define RTC_CONTROLB RTC_SECONDS
37 #define RTC_CONTROLC RTC_DAY_OF_WEEK
38
39 #define RTC_CA_WRITE 0x80
40 #define RTC_CA_READ 0x40
41
42 #define RTC_CB_OSC_DISABLE 0x80
43
44 #define RTC_CC_BATTERY_FLAG 0x80
45 #define RTC_CC_FREQ_TEST 0x40
46
47 /* ------------------------------------------------------------------------- */
48
rtc_get(struct rtc_time * tmp)49 int rtc_get( struct rtc_time *tmp )
50 {
51 uchar sec, min, hour;
52 uchar mday, wday, mon, year;
53
54 int century;
55
56 uchar reg_a;
57
58 reg_a = rtc_read( RTC_CONTROLA );
59 /* lock clock registers for read */
60 rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_READ ));
61
62 sec = rtc_read( RTC_SECONDS );
63 min = rtc_read( RTC_MINUTES );
64 hour = rtc_read( RTC_HOURS );
65 mday = rtc_read( RTC_DAY_OF_MONTH );
66 wday = rtc_read( RTC_DAY_OF_WEEK );
67 mon = rtc_read( RTC_MONTH );
68 year = rtc_read( RTC_YEAR );
69 century = rtc_read( RTC_CENTURY );
70
71 /* unlock clock registers after read */
72 rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_READ ));
73
74 #ifdef RTC_DEBUG
75 printf( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
76 "hr: %02x min: %02x sec: %02x\n",
77 year, mon_cent, mday, wday,
78 hour, min, sec );
79 #endif
80 tmp->tm_sec = bcd2bin( sec & 0x7F );
81 tmp->tm_min = bcd2bin( min & 0x7F );
82 tmp->tm_hour = bcd2bin( hour & 0x3F );
83 tmp->tm_mday = bcd2bin( mday & 0x3F );
84 tmp->tm_mon = bcd2bin( mon & 0x1F );
85 tmp->tm_wday = bcd2bin( wday & 0x07 );
86
87 /* glue year from century and year in century */
88 tmp->tm_year = bcd2bin( year ) +
89 ( bcd2bin( century & 0x3F ) * 100 );
90
91 tmp->tm_yday = 0;
92 tmp->tm_isdst= 0;
93 #ifdef RTC_DEBUG
94 printf( "Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
95 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
96 tmp->tm_hour, tmp->tm_min, tmp->tm_sec );
97 #endif
98 return 0;
99 }
100
rtc_set(struct rtc_time * tmp)101 int rtc_set( struct rtc_time *tmp )
102 {
103 uchar reg_a;
104 #ifdef RTC_DEBUG
105 printf( "Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
106 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
107 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
108 #endif
109 /* lock clock registers for write */
110 reg_a = rtc_read( RTC_CONTROLA );
111 rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_WRITE ));
112
113 rtc_write( RTC_MONTH, bin2bcd( tmp->tm_mon ));
114
115 rtc_write( RTC_DAY_OF_WEEK, bin2bcd( tmp->tm_wday ));
116 rtc_write( RTC_DAY_OF_MONTH, bin2bcd( tmp->tm_mday ));
117 rtc_write( RTC_HOURS, bin2bcd( tmp->tm_hour ));
118 rtc_write( RTC_MINUTES, bin2bcd( tmp->tm_min ));
119 rtc_write( RTC_SECONDS, bin2bcd( tmp->tm_sec ));
120
121 /* break year up into century and year in century */
122 rtc_write( RTC_YEAR, bin2bcd( tmp->tm_year % 100 ));
123 rtc_write( RTC_CENTURY, bin2bcd( tmp->tm_year / 100 ));
124
125 /* unlock clock registers after read */
126 rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_WRITE ));
127
128 return 0;
129 }
130
rtc_reset(void)131 void rtc_reset (void)
132 {
133 uchar reg_a, reg_b, reg_c;
134
135 reg_a = rtc_read( RTC_CONTROLA );
136 reg_b = rtc_read( RTC_CONTROLB );
137
138 if ( reg_b & RTC_CB_OSC_DISABLE )
139 {
140 printf( "real-time-clock was stopped. Now starting...\n" );
141 reg_a |= RTC_CA_WRITE;
142 reg_b &= ~RTC_CB_OSC_DISABLE;
143
144 rtc_write( RTC_CONTROLA, reg_a );
145 rtc_write( RTC_CONTROLB, reg_b );
146 }
147
148 /* make sure read/write clock register bits are cleared */
149 reg_a &= ~( RTC_CA_WRITE | RTC_CA_READ );
150 rtc_write( RTC_CONTROLA, reg_a );
151
152 reg_c = rtc_read( RTC_CONTROLC );
153 if (( reg_c & RTC_CC_BATTERY_FLAG ) == 0 )
154 printf( "RTC battery low. Clock setting may not be reliable.\n" );
155 }
156
157 /* ------------------------------------------------------------------------- */
158
rtc_read(unsigned int addr)159 static uchar rtc_read( unsigned int addr )
160 {
161 uchar val = in8( addr );
162 #ifdef RTC_DEBUG
163 printf( "rtc_read: %x:%x\n", addr, val );
164 #endif
165 return( val );
166 }
167
rtc_write(unsigned int addr,uchar val)168 static void rtc_write( unsigned int addr, uchar val )
169 {
170 #ifdef RTC_DEBUG
171 printf( "rtc_write: %x:%x\n", addr, val );
172 #endif
173 out8( addr, val );
174 }
175
176 #endif
177