1 /* 2 * (C) Copyright 2001 3 * Erik Theisen, Wave 7 Optics, etheisen@mindspring.com. 4 * 5 * See file CREDITS for list of people who contributed to this 6 * project. 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License as 10 * published by the Free Software Foundation; either version 2 of 11 * the License, or (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 21 * MA 02111-1307 USA 22 */ 23 24 /* 25 * Date & Time support for ST Electronics M48T35Ax RTC 26 */ 27 28 /*#define DEBUG */ 29 30 31 #include <common.h> 32 #include <command.h> 33 #include <rtc.h> 34 #include <config.h> 35 36 #if defined(CONFIG_CMD_DATE) 37 38 static uchar rtc_read (uchar reg); 39 static void rtc_write (uchar reg, uchar val); 40 static uchar bin2bcd (unsigned int n); 41 static unsigned bcd2bin(uchar c); 42 43 /* ------------------------------------------------------------------------- */ 44 45 int rtc_get (struct rtc_time *tmp) 46 { 47 uchar sec, min, hour, cent_day, date, month, year; 48 uchar ccr; /* Clock control register */ 49 50 /* Lock RTC for read using clock control register */ 51 ccr = rtc_read(0); 52 ccr = ccr | 0x40; 53 rtc_write(0, ccr); 54 55 sec = rtc_read (0x1); 56 min = rtc_read (0x2); 57 hour = rtc_read (0x3); 58 cent_day= rtc_read (0x4); 59 date = rtc_read (0x5); 60 month = rtc_read (0x6); 61 year = rtc_read (0x7); 62 63 /* UNLock RTC */ 64 ccr = rtc_read(0); 65 ccr = ccr & 0xBF; 66 rtc_write(0, ccr); 67 68 debug ( "Get RTC year: %02x month: %02x date: %02x cent_day: %02x " 69 "hr: %02x min: %02x sec: %02x\n", 70 year, month, date, cent_day, 71 hour, min, sec ); 72 73 tmp->tm_sec = bcd2bin (sec & 0x7F); 74 tmp->tm_min = bcd2bin (min & 0x7F); 75 tmp->tm_hour = bcd2bin (hour & 0x3F); 76 tmp->tm_mday = bcd2bin (date & 0x3F); 77 tmp->tm_mon = bcd2bin (month & 0x1F); 78 tmp->tm_year = bcd2bin (year) + ((cent_day & 0x10) ? 2000 : 1900); 79 tmp->tm_wday = bcd2bin (cent_day & 0x07); 80 tmp->tm_yday = 0; 81 tmp->tm_isdst= 0; 82 83 debug ( "Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 84 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 85 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 86 87 return 0; 88 } 89 90 int rtc_set (struct rtc_time *tmp) 91 { 92 uchar ccr; /* Clock control register */ 93 uchar century; 94 95 debug ( "Set 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 99 /* Lock RTC for write using clock control register */ 100 ccr = rtc_read(0); 101 ccr = ccr | 0x80; 102 rtc_write(0, ccr); 103 104 rtc_write (0x07, bin2bcd(tmp->tm_year % 100)); 105 rtc_write (0x06, bin2bcd(tmp->tm_mon)); 106 rtc_write (0x05, bin2bcd(tmp->tm_mday)); 107 108 century = ((tmp->tm_year >= 2000) ? 0x10 : 0) | 0x20; 109 rtc_write (0x04, bin2bcd(tmp->tm_wday) | century); 110 111 rtc_write (0x03, bin2bcd(tmp->tm_hour)); 112 rtc_write (0x02, bin2bcd(tmp->tm_min )); 113 rtc_write (0x01, bin2bcd(tmp->tm_sec )); 114 115 /* UNLock RTC */ 116 ccr = rtc_read(0); 117 ccr = ccr & 0x7F; 118 rtc_write(0, ccr); 119 120 return 0; 121 } 122 123 void rtc_reset (void) 124 { 125 uchar val; 126 127 /* Clear all clock control registers */ 128 rtc_write (0x0, 0x80); /* No Read Lock or calibration */ 129 130 /* Clear stop bit */ 131 val = rtc_read (0x1); 132 val &= 0x7f; 133 rtc_write(0x1, val); 134 135 /* Enable century / disable frequency test */ 136 val = rtc_read (0x4); 137 val = (val & 0xBF) | 0x20; 138 rtc_write(0x4, val); 139 140 /* Clear write lock */ 141 rtc_write(0x0, 0); 142 } 143 144 /* ------------------------------------------------------------------------- */ 145 146 static uchar rtc_read (uchar reg) 147 { 148 uchar val; 149 val = *(unsigned char *) 150 ((CONFIG_SYS_NVRAM_BASE_ADDR + CONFIG_SYS_NVRAM_SIZE - 8) + reg); 151 return val; 152 } 153 154 static void rtc_write (uchar reg, uchar val) 155 { 156 *(unsigned char *) 157 ((CONFIG_SYS_NVRAM_BASE_ADDR + CONFIG_SYS_NVRAM_SIZE - 8) + reg) = val; 158 } 159 160 static unsigned bcd2bin (uchar n) 161 { 162 return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F)); 163 } 164 165 static unsigned char bin2bcd (unsigned int n) 166 { 167 return (((n / 10) << 4) | (n % 10)); 168 } 169 170 #endif 171