1 /* 2 * (C) Copyright 2001, 2002, 2003 3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4 * Keith Outwater, keith_outwater@mvis.com` 5 * Steven Scholz, steven.scholz@imc-berlin.de 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 (no alarms) for Dallas Semiconductor (now Maxim) 28 * DS1307 and DS1338 Real Time Clock (RTC). 29 * 30 * based on ds1337.c 31 */ 32 33 #include <common.h> 34 #include <command.h> 35 #include <rtc.h> 36 #include <i2c.h> 37 38 #if (defined(CONFIG_RTC_DS1307) || defined(CONFIG_RTC_DS1338) ) && \ 39 defined(CONFIG_CMD_DATE) 40 41 /*---------------------------------------------------------------------*/ 42 #undef DEBUG_RTC 43 44 #ifdef DEBUG_RTC 45 #define DEBUGR(fmt,args...) printf(fmt ,##args) 46 #else 47 #define DEBUGR(fmt,args...) 48 #endif 49 /*---------------------------------------------------------------------*/ 50 51 #ifndef CFG_I2C_RTC_ADDR 52 # define CFG_I2C_RTC_ADDR 0x68 53 #endif 54 55 #if defined(CONFIG_RTC_DS1307) && (CFG_I2C_SPEED > 100000) 56 # error The DS1307 is specified only up to 100kHz! 57 #endif 58 59 /* 60 * RTC register addresses 61 */ 62 #define RTC_SEC_REG_ADDR 0x00 63 #define RTC_MIN_REG_ADDR 0x01 64 #define RTC_HR_REG_ADDR 0x02 65 #define RTC_DAY_REG_ADDR 0x03 66 #define RTC_DATE_REG_ADDR 0x04 67 #define RTC_MON_REG_ADDR 0x05 68 #define RTC_YR_REG_ADDR 0x06 69 #define RTC_CTL_REG_ADDR 0x07 70 71 #define RTC_SEC_BIT_CH 0x80 /* Clock Halt (in Register 0) */ 72 73 #define RTC_CTL_BIT_RS0 0x01 /* Rate select 0 */ 74 #define RTC_CTL_BIT_RS1 0x02 /* Rate select 1 */ 75 #define RTC_CTL_BIT_SQWE 0x10 /* Square Wave Enable */ 76 #define RTC_CTL_BIT_OUT 0x80 /* Output Control */ 77 78 static uchar rtc_read (uchar reg); 79 static void rtc_write (uchar reg, uchar val); 80 static uchar bin2bcd (unsigned int n); 81 static unsigned bcd2bin (uchar c); 82 83 /* 84 * Get the current time from the RTC 85 */ 86 int rtc_get (struct rtc_time *tmp) 87 { 88 int rel = 0; 89 uchar sec, min, hour, mday, wday, mon, year; 90 91 sec = rtc_read (RTC_SEC_REG_ADDR); 92 min = rtc_read (RTC_MIN_REG_ADDR); 93 hour = rtc_read (RTC_HR_REG_ADDR); 94 wday = rtc_read (RTC_DAY_REG_ADDR); 95 mday = rtc_read (RTC_DATE_REG_ADDR); 96 mon = rtc_read (RTC_MON_REG_ADDR); 97 year = rtc_read (RTC_YR_REG_ADDR); 98 99 DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x " 100 "hr: %02x min: %02x sec: %02x\n", 101 year, mon, mday, wday, hour, min, sec); 102 103 if (sec & RTC_SEC_BIT_CH) { 104 printf ("### Warning: RTC oscillator has stopped\n"); 105 /* clear the CH flag */ 106 rtc_write (RTC_SEC_REG_ADDR, 107 rtc_read (RTC_SEC_REG_ADDR) & ~RTC_SEC_BIT_CH); 108 rel = -1; 109 } 110 111 tmp->tm_sec = bcd2bin (sec & 0x7F); 112 tmp->tm_min = bcd2bin (min & 0x7F); 113 tmp->tm_hour = bcd2bin (hour & 0x3F); 114 tmp->tm_mday = bcd2bin (mday & 0x3F); 115 tmp->tm_mon = bcd2bin (mon & 0x1F); 116 tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000); 117 tmp->tm_wday = bcd2bin ((wday - 1) & 0x07); 118 tmp->tm_yday = 0; 119 tmp->tm_isdst= 0; 120 121 DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 122 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 123 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 124 125 return rel; 126 } 127 128 129 /* 130 * Set the RTC 131 */ 132 void rtc_set (struct rtc_time *tmp) 133 { 134 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 135 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 136 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 137 138 if (tmp->tm_year < 1970 || tmp->tm_year > 2069) 139 printf("WARNING: year should be between 1970 and 2069!\n"); 140 141 rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100)); 142 rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon)); 143 rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1)); 144 rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday)); 145 rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour)); 146 rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min)); 147 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec)); 148 } 149 150 151 /* 152 * Reset the RTC. We setting the date back to 1970-01-01. 153 * We also enable the oscillator output on the SQW/OUT pin and program 154 * it for 32,768 Hz output. Note that according to the datasheet, turning 155 * on the square wave output increases the current drain on the backup 156 * battery to something between 480nA and 800nA. 157 */ 158 void rtc_reset (void) 159 { 160 struct rtc_time tmp; 161 162 rtc_write (RTC_SEC_REG_ADDR, 0x00); /* clearing Clock Halt */ 163 rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS0); 164 165 tmp.tm_year = 1970; 166 tmp.tm_mon = 1; 167 tmp.tm_mday= 1; 168 tmp.tm_hour = 0; 169 tmp.tm_min = 0; 170 tmp.tm_sec = 0; 171 172 rtc_set(&tmp); 173 174 printf ( "RTC: %4d-%02d-%02d %2d:%02d:%02d UTC\n", 175 tmp.tm_year, tmp.tm_mon, tmp.tm_mday, 176 tmp.tm_hour, tmp.tm_min, tmp.tm_sec); 177 178 return; 179 } 180 181 182 /* 183 * Helper functions 184 */ 185 186 static 187 uchar rtc_read (uchar reg) 188 { 189 return (i2c_reg_read (CFG_I2C_RTC_ADDR, reg)); 190 } 191 192 193 static void rtc_write (uchar reg, uchar val) 194 { 195 i2c_reg_write (CFG_I2C_RTC_ADDR, reg, val); 196 } 197 198 static unsigned bcd2bin (uchar n) 199 { 200 return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F)); 201 } 202 203 static unsigned char bin2bcd (unsigned int n) 204 { 205 return (((n / 10) << 4) | (n % 10)); 206 } 207 208 #endif 209