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 * See file CREDITS for list of people who contributed to this 8 * project. 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License as 12 * published by the Free Software Foundation; either version 2 of 13 * the License, or (at your option) any later version. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public License 21 * along with this program; if not, write to the Free Software 22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 23 * MA 02111-1307 USA 24 */ 25 26 /* 27 * Date & Time support for the DS174x RTC 28 */ 29 30 /*#define DEBUG*/ 31 32 #include <common.h> 33 #include <command.h> 34 #include <rtc.h> 35 36 #if defined(CONFIG_CMD_DATE) 37 38 static uchar rtc_read( unsigned int addr ); 39 static void rtc_write( unsigned int addr, uchar val); 40 41 #define RTC_BASE ( CONFIG_SYS_NVRAM_SIZE + CONFIG_SYS_NVRAM_BASE_ADDR ) 42 43 #define RTC_YEAR ( RTC_BASE + 7 ) 44 #define RTC_MONTH ( RTC_BASE + 6 ) 45 #define RTC_DAY_OF_MONTH ( RTC_BASE + 5 ) 46 #define RTC_DAY_OF_WEEK ( RTC_BASE + 4 ) 47 #define RTC_HOURS ( RTC_BASE + 3 ) 48 #define RTC_MINUTES ( RTC_BASE + 2 ) 49 #define RTC_SECONDS ( RTC_BASE + 1 ) 50 #define RTC_CENTURY ( RTC_BASE + 0 ) 51 52 #define RTC_CONTROLA RTC_CENTURY 53 #define RTC_CONTROLB RTC_SECONDS 54 #define RTC_CONTROLC RTC_DAY_OF_WEEK 55 56 #define RTC_CA_WRITE 0x80 57 #define RTC_CA_READ 0x40 58 59 #define RTC_CB_OSC_DISABLE 0x80 60 61 #define RTC_CC_BATTERY_FLAG 0x80 62 #define RTC_CC_FREQ_TEST 0x40 63 64 /* ------------------------------------------------------------------------- */ 65 66 int rtc_get( struct rtc_time *tmp ) 67 { 68 uchar sec, min, hour; 69 uchar mday, wday, mon, year; 70 71 int century; 72 73 uchar reg_a; 74 75 reg_a = rtc_read( RTC_CONTROLA ); 76 /* lock clock registers for read */ 77 rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_READ )); 78 79 sec = rtc_read( RTC_SECONDS ); 80 min = rtc_read( RTC_MINUTES ); 81 hour = rtc_read( RTC_HOURS ); 82 mday = rtc_read( RTC_DAY_OF_MONTH ); 83 wday = rtc_read( RTC_DAY_OF_WEEK ); 84 mon = rtc_read( RTC_MONTH ); 85 year = rtc_read( RTC_YEAR ); 86 century = rtc_read( RTC_CENTURY ); 87 88 /* unlock clock registers after read */ 89 rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_READ )); 90 91 #ifdef RTC_DEBUG 92 printf( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x " 93 "hr: %02x min: %02x sec: %02x\n", 94 year, mon_cent, mday, wday, 95 hour, min, sec ); 96 #endif 97 tmp->tm_sec = bcd2bin( sec & 0x7F ); 98 tmp->tm_min = bcd2bin( min & 0x7F ); 99 tmp->tm_hour = bcd2bin( hour & 0x3F ); 100 tmp->tm_mday = bcd2bin( mday & 0x3F ); 101 tmp->tm_mon = bcd2bin( mon & 0x1F ); 102 tmp->tm_wday = bcd2bin( wday & 0x07 ); 103 104 /* glue year from century and year in century */ 105 tmp->tm_year = bcd2bin( year ) + 106 ( bcd2bin( century & 0x3F ) * 100 ); 107 108 tmp->tm_yday = 0; 109 tmp->tm_isdst= 0; 110 #ifdef RTC_DEBUG 111 printf( "Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 112 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 113 tmp->tm_hour, tmp->tm_min, tmp->tm_sec ); 114 #endif 115 return 0; 116 } 117 118 int rtc_set( struct rtc_time *tmp ) 119 { 120 uchar reg_a; 121 #ifdef RTC_DEBUG 122 printf( "Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 123 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 124 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 125 #endif 126 /* lock clock registers for write */ 127 reg_a = rtc_read( RTC_CONTROLA ); 128 rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_WRITE )); 129 130 rtc_write( RTC_MONTH, bin2bcd( tmp->tm_mon )); 131 132 rtc_write( RTC_DAY_OF_WEEK, bin2bcd( tmp->tm_wday )); 133 rtc_write( RTC_DAY_OF_MONTH, bin2bcd( tmp->tm_mday )); 134 rtc_write( RTC_HOURS, bin2bcd( tmp->tm_hour )); 135 rtc_write( RTC_MINUTES, bin2bcd( tmp->tm_min )); 136 rtc_write( RTC_SECONDS, bin2bcd( tmp->tm_sec )); 137 138 /* break year up into century and year in century */ 139 rtc_write( RTC_YEAR, bin2bcd( tmp->tm_year % 100 )); 140 rtc_write( RTC_CENTURY, bin2bcd( tmp->tm_year / 100 )); 141 142 /* unlock clock registers after read */ 143 rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_WRITE )); 144 145 return 0; 146 } 147 148 void rtc_reset (void) 149 { 150 uchar reg_a, reg_b, reg_c; 151 152 reg_a = rtc_read( RTC_CONTROLA ); 153 reg_b = rtc_read( RTC_CONTROLB ); 154 155 if ( reg_b & RTC_CB_OSC_DISABLE ) 156 { 157 printf( "real-time-clock was stopped. Now starting...\n" ); 158 reg_a |= RTC_CA_WRITE; 159 reg_b &= ~RTC_CB_OSC_DISABLE; 160 161 rtc_write( RTC_CONTROLA, reg_a ); 162 rtc_write( RTC_CONTROLB, reg_b ); 163 } 164 165 /* make sure read/write clock register bits are cleared */ 166 reg_a &= ~( RTC_CA_WRITE | RTC_CA_READ ); 167 rtc_write( RTC_CONTROLA, reg_a ); 168 169 reg_c = rtc_read( RTC_CONTROLC ); 170 if (( reg_c & RTC_CC_BATTERY_FLAG ) == 0 ) 171 printf( "RTC battery low. Clock setting may not be reliable.\n" ); 172 } 173 174 /* ------------------------------------------------------------------------- */ 175 176 static uchar rtc_read( unsigned int addr ) 177 { 178 uchar val = in8( addr ); 179 #ifdef RTC_DEBUG 180 printf( "rtc_read: %x:%x\n", addr, val ); 181 #endif 182 return( val ); 183 } 184 185 static void rtc_write( unsigned int addr, uchar val ) 186 { 187 #ifdef RTC_DEBUG 188 printf( "rtc_write: %x:%x\n", addr, val ); 189 #endif 190 out8( addr, val ); 191 } 192 193 #endif 194