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 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 } 100 101 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 } 130 131 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 /* ------------------------------------------------------------------------- */ 158 159 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 } 167 168 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