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