1 /* 2 * (C) Copyright 2001 3 * ARIO Data Networks, Inc. dchiu@ariodata.com 4 * 5 * Based on MontaVista DS1743 code and U-Boot mc146818 code 6 * 7 * SPDX-License-Identifier: GPL-2.0+ 8 */ 9 10 /* 11 * Date & Time support for the DS174x RTC 12 */ 13 14 /*#define DEBUG*/ 15 16 #include <common.h> 17 #include <command.h> 18 #include <rtc.h> 19 20 #if defined(CONFIG_CMD_DATE) 21 22 static uchar rtc_read( unsigned int addr ); 23 static void rtc_write( unsigned int addr, uchar val); 24 25 #define RTC_BASE ( CONFIG_SYS_NVRAM_SIZE + CONFIG_SYS_NVRAM_BASE_ADDR ) 26 27 #define RTC_YEAR ( RTC_BASE + 7 ) 28 #define RTC_MONTH ( RTC_BASE + 6 ) 29 #define RTC_DAY_OF_MONTH ( RTC_BASE + 5 ) 30 #define RTC_DAY_OF_WEEK ( RTC_BASE + 4 ) 31 #define RTC_HOURS ( RTC_BASE + 3 ) 32 #define RTC_MINUTES ( RTC_BASE + 2 ) 33 #define RTC_SECONDS ( RTC_BASE + 1 ) 34 #define RTC_CENTURY ( RTC_BASE + 0 ) 35 36 #define RTC_CONTROLA RTC_CENTURY 37 #define RTC_CONTROLB RTC_SECONDS 38 #define RTC_CONTROLC RTC_DAY_OF_WEEK 39 40 #define RTC_CA_WRITE 0x80 41 #define RTC_CA_READ 0x40 42 43 #define RTC_CB_OSC_DISABLE 0x80 44 45 #define RTC_CC_BATTERY_FLAG 0x80 46 #define RTC_CC_FREQ_TEST 0x40 47 48 /* ------------------------------------------------------------------------- */ 49 50 int rtc_get( struct rtc_time *tmp ) 51 { 52 uchar sec, min, hour; 53 uchar mday, wday, mon, year; 54 55 int century; 56 57 uchar reg_a; 58 59 reg_a = rtc_read( RTC_CONTROLA ); 60 /* lock clock registers for read */ 61 rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_READ )); 62 63 sec = rtc_read( RTC_SECONDS ); 64 min = rtc_read( RTC_MINUTES ); 65 hour = rtc_read( RTC_HOURS ); 66 mday = rtc_read( RTC_DAY_OF_MONTH ); 67 wday = rtc_read( RTC_DAY_OF_WEEK ); 68 mon = rtc_read( RTC_MONTH ); 69 year = rtc_read( RTC_YEAR ); 70 century = rtc_read( RTC_CENTURY ); 71 72 /* unlock clock registers after read */ 73 rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_READ )); 74 75 #ifdef RTC_DEBUG 76 printf( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x " 77 "hr: %02x min: %02x sec: %02x\n", 78 year, mon_cent, mday, wday, 79 hour, min, sec ); 80 #endif 81 tmp->tm_sec = bcd2bin( sec & 0x7F ); 82 tmp->tm_min = bcd2bin( min & 0x7F ); 83 tmp->tm_hour = bcd2bin( hour & 0x3F ); 84 tmp->tm_mday = bcd2bin( mday & 0x3F ); 85 tmp->tm_mon = bcd2bin( mon & 0x1F ); 86 tmp->tm_wday = bcd2bin( wday & 0x07 ); 87 88 /* glue year from century and year in century */ 89 tmp->tm_year = bcd2bin( year ) + 90 ( bcd2bin( century & 0x3F ) * 100 ); 91 92 tmp->tm_yday = 0; 93 tmp->tm_isdst= 0; 94 #ifdef RTC_DEBUG 95 printf( "Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 96 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 97 tmp->tm_hour, tmp->tm_min, tmp->tm_sec ); 98 #endif 99 return 0; 100 } 101 102 int rtc_set( struct rtc_time *tmp ) 103 { 104 uchar reg_a; 105 #ifdef RTC_DEBUG 106 printf( "Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 107 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 108 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 109 #endif 110 /* lock clock registers for write */ 111 reg_a = rtc_read( RTC_CONTROLA ); 112 rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_WRITE )); 113 114 rtc_write( RTC_MONTH, bin2bcd( tmp->tm_mon )); 115 116 rtc_write( RTC_DAY_OF_WEEK, bin2bcd( tmp->tm_wday )); 117 rtc_write( RTC_DAY_OF_MONTH, bin2bcd( tmp->tm_mday )); 118 rtc_write( RTC_HOURS, bin2bcd( tmp->tm_hour )); 119 rtc_write( RTC_MINUTES, bin2bcd( tmp->tm_min )); 120 rtc_write( RTC_SECONDS, bin2bcd( tmp->tm_sec )); 121 122 /* break year up into century and year in century */ 123 rtc_write( RTC_YEAR, bin2bcd( tmp->tm_year % 100 )); 124 rtc_write( RTC_CENTURY, bin2bcd( tmp->tm_year / 100 )); 125 126 /* unlock clock registers after read */ 127 rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_WRITE )); 128 129 return 0; 130 } 131 132 void rtc_reset (void) 133 { 134 uchar reg_a, reg_b, reg_c; 135 136 reg_a = rtc_read( RTC_CONTROLA ); 137 reg_b = rtc_read( RTC_CONTROLB ); 138 139 if ( reg_b & RTC_CB_OSC_DISABLE ) 140 { 141 printf( "real-time-clock was stopped. Now starting...\n" ); 142 reg_a |= RTC_CA_WRITE; 143 reg_b &= ~RTC_CB_OSC_DISABLE; 144 145 rtc_write( RTC_CONTROLA, reg_a ); 146 rtc_write( RTC_CONTROLB, reg_b ); 147 } 148 149 /* make sure read/write clock register bits are cleared */ 150 reg_a &= ~( RTC_CA_WRITE | RTC_CA_READ ); 151 rtc_write( RTC_CONTROLA, reg_a ); 152 153 reg_c = rtc_read( RTC_CONTROLC ); 154 if (( reg_c & RTC_CC_BATTERY_FLAG ) == 0 ) 155 printf( "RTC battery low. Clock setting may not be reliable.\n" ); 156 } 157 158 /* ------------------------------------------------------------------------- */ 159 160 static uchar rtc_read( unsigned int addr ) 161 { 162 uchar val = in8( addr ); 163 #ifdef RTC_DEBUG 164 printf( "rtc_read: %x:%x\n", addr, val ); 165 #endif 166 return( val ); 167 } 168 169 static void rtc_write( unsigned int addr, uchar val ) 170 { 171 #ifdef RTC_DEBUG 172 printf( "rtc_write: %x:%x\n", addr, val ); 173 #endif 174 out8( addr, val ); 175 } 176 177 #endif 178