1 /* 2 * (C) Copyright 2002 3 * ARIO Data Networks, Inc. dchiu@ariodata.com 4 * 5 * modified for DS1556: 6 * Frank Panno <fpanno@delphintech.com>, Delphin Technology AG 7 * 8 * Based on MontaVista DS1743 code and U-Boot mc146818 code 9 * 10 * SPDX-License-Identifier: GPL-2.0+ 11 */ 12 13 /* 14 * Date & Time support for the DS1556 RTC 15 */ 16 17 /*#define RTC_DEBUG */ 18 19 #include <common.h> 20 #include <command.h> 21 #include <rtc.h> 22 23 #if defined(CONFIG_CMD_DATE) 24 25 static uchar rtc_read( unsigned int addr ); 26 static void rtc_write( unsigned int addr, uchar val); 27 28 #define RTC_BASE ( CONFIG_SYS_NVRAM_SIZE + CONFIG_SYS_NVRAM_BASE_ADDR ) 29 30 #define RTC_YEAR ( RTC_BASE + 0xf ) 31 #define RTC_MONTH ( RTC_BASE + 0xe ) 32 #define RTC_DAY_OF_MONTH ( RTC_BASE + 0xd ) 33 #define RTC_DAY_OF_WEEK ( RTC_BASE + 0xc ) 34 #define RTC_HOURS ( RTC_BASE + 0xb ) 35 #define RTC_MINUTES ( RTC_BASE + 0xa ) 36 #define RTC_SECONDS ( RTC_BASE + 0x9 ) 37 #define RTC_CENTURY ( RTC_BASE + 0x8 ) 38 39 #define RTC_CONTROLA RTC_CENTURY 40 #define RTC_CONTROLB RTC_SECONDS 41 #define RTC_CONTROLC RTC_BASE 42 43 #define RTC_CA_WRITE 0x80 44 #define RTC_CA_READ 0x40 45 46 #define RTC_CB_OSC_DISABLE 0x80 47 48 #define RTC_CC_BATTERY_FLAG 0x10 49 #define RTC_CC_FREQ_TEST 0x40 50 51 /* ------------------------------------------------------------------------- */ 52 53 int rtc_get( struct rtc_time *tmp ) 54 { 55 uchar sec, min, hour; 56 uchar mday, wday, mon, year; 57 58 int century; 59 60 uchar reg_a; 61 62 reg_a = rtc_read( RTC_CONTROLA ); 63 /* lock clock registers for read */ 64 rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_READ )); 65 66 sec = rtc_read( RTC_SECONDS ); 67 min = rtc_read( RTC_MINUTES ); 68 hour = rtc_read( RTC_HOURS ); 69 mday = rtc_read( RTC_DAY_OF_MONTH ); 70 wday = rtc_read( RTC_DAY_OF_WEEK ); 71 mon = rtc_read( RTC_MONTH ); 72 year = rtc_read( RTC_YEAR ); 73 century = rtc_read( RTC_CENTURY ); 74 75 /* unlock clock registers after read */ 76 rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_READ )); 77 78 #ifdef RTC_DEBUG 79 printf( "Get RTC year: %02x mon/cent: %02x mon: %02x mday: %02x wday: %02x " 80 "hr: %02x min: %02x sec: %02x\n", 81 year, century, mon, mday, wday, 82 hour, min, sec ); 83 #endif 84 tmp->tm_sec = bcd2bin( sec & 0x7F ); 85 tmp->tm_min = bcd2bin( min & 0x7F ); 86 tmp->tm_hour = bcd2bin( hour & 0x3F ); 87 tmp->tm_mday = bcd2bin( mday & 0x3F ); 88 tmp->tm_mon = bcd2bin( mon & 0x1F ); 89 tmp->tm_wday = bcd2bin( wday & 0x07 ); 90 91 /* glue year from century and year in century */ 92 tmp->tm_year = bcd2bin( year ) + 93 ( bcd2bin( century & 0x3F ) * 100 ); 94 95 tmp->tm_yday = 0; 96 tmp->tm_isdst= 0; 97 #ifdef RTC_DEBUG 98 printf( "Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 99 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 100 tmp->tm_hour, tmp->tm_min, tmp->tm_sec ); 101 #endif 102 return 0; 103 } 104 105 int rtc_set( struct rtc_time *tmp ) 106 { 107 uchar reg_a; 108 #ifdef RTC_DEBUG 109 printf( "Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 110 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 111 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 112 #endif 113 /* lock clock registers for write */ 114 reg_a = rtc_read( RTC_CONTROLA ); 115 rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_WRITE )); 116 117 rtc_write( RTC_MONTH, bin2bcd( tmp->tm_mon )); 118 119 rtc_write( RTC_DAY_OF_WEEK, bin2bcd( tmp->tm_wday )); 120 rtc_write( RTC_DAY_OF_MONTH, bin2bcd( tmp->tm_mday )); 121 rtc_write( RTC_HOURS, bin2bcd( tmp->tm_hour )); 122 rtc_write( RTC_MINUTES, bin2bcd( tmp->tm_min )); 123 rtc_write( RTC_SECONDS, bin2bcd( tmp->tm_sec )); 124 125 /* break year up into century and year in century */ 126 rtc_write( RTC_YEAR, bin2bcd( tmp->tm_year % 100 )); 127 rtc_write( RTC_CENTURY, bin2bcd( tmp->tm_year / 100 )); 128 129 /* unlock clock registers after read */ 130 rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_WRITE )); 131 132 return 0; 133 } 134 135 void rtc_reset (void) 136 { 137 uchar reg_a, reg_b, reg_c; 138 139 reg_a = rtc_read( RTC_CONTROLA ); 140 reg_b = rtc_read( RTC_CONTROLB ); 141 142 if ( reg_b & RTC_CB_OSC_DISABLE ) 143 { 144 printf( "real-time-clock was stopped. Now starting...\n" ); 145 reg_a |= RTC_CA_WRITE; 146 reg_b &= ~RTC_CB_OSC_DISABLE; 147 148 rtc_write( RTC_CONTROLA, reg_a ); 149 rtc_write( RTC_CONTROLB, reg_b ); 150 } 151 152 /* make sure read/write clock register bits are cleared */ 153 reg_a &= ~( RTC_CA_WRITE | RTC_CA_READ ); 154 rtc_write( RTC_CONTROLA, reg_a ); 155 156 reg_c = rtc_read( RTC_CONTROLC ); 157 if (( reg_c & RTC_CC_BATTERY_FLAG ) == 0 ) 158 printf( "RTC battery low. Clock setting may not be reliable.\n" ); 159 } 160 161 /* ------------------------------------------------------------------------- */ 162 163 static uchar rtc_read( unsigned int addr ) 164 { 165 uchar val = *(volatile unsigned char*)(addr); 166 #ifdef RTC_DEBUG 167 printf( "rtc_read: %x:%x\n", addr, val ); 168 #endif 169 return( val ); 170 } 171 172 static void rtc_write( unsigned int addr, uchar val ) 173 { 174 #ifdef RTC_DEBUG 175 printf( "rtc_write: %x:%x\n", addr, val ); 176 #endif 177 *(volatile unsigned char*)(addr) = val; 178 } 179 180 #endif 181