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_CMD_DATE) 39 40 /*---------------------------------------------------------------------*/ 41 #undef DEBUG_RTC 42 43 #ifdef DEBUG_RTC 44 #define DEBUGR(fmt,args...) printf(fmt ,##args) 45 #else 46 #define DEBUGR(fmt,args...) 47 #endif 48 /*---------------------------------------------------------------------*/ 49 50 #ifndef CONFIG_SYS_I2C_RTC_ADDR 51 # define CONFIG_SYS_I2C_RTC_ADDR 0x68 52 #endif 53 54 #if defined(CONFIG_RTC_DS1307) && (CONFIG_SYS_I2C_SPEED > 100000) 55 # error The DS1307 is specified only up to 100kHz! 56 #endif 57 58 /* 59 * RTC register addresses 60 */ 61 #define RTC_SEC_REG_ADDR 0x00 62 #define RTC_MIN_REG_ADDR 0x01 63 #define RTC_HR_REG_ADDR 0x02 64 #define RTC_DAY_REG_ADDR 0x03 65 #define RTC_DATE_REG_ADDR 0x04 66 #define RTC_MON_REG_ADDR 0x05 67 #define RTC_YR_REG_ADDR 0x06 68 #define RTC_CTL_REG_ADDR 0x07 69 70 #define RTC_SEC_BIT_CH 0x80 /* Clock Halt (in Register 0) */ 71 72 #define RTC_CTL_BIT_RS0 0x01 /* Rate select 0 */ 73 #define RTC_CTL_BIT_RS1 0x02 /* Rate select 1 */ 74 #define RTC_CTL_BIT_SQWE 0x10 /* Square Wave Enable */ 75 #define RTC_CTL_BIT_OUT 0x80 /* Output Control */ 76 77 static uchar rtc_read (uchar reg); 78 static void rtc_write (uchar reg, uchar val); 79 80 /* 81 * Get the current time from the RTC 82 */ 83 int rtc_get (struct rtc_time *tmp) 84 { 85 int rel = 0; 86 uchar sec, min, hour, mday, wday, mon, year; 87 88 sec = rtc_read (RTC_SEC_REG_ADDR); 89 min = rtc_read (RTC_MIN_REG_ADDR); 90 hour = rtc_read (RTC_HR_REG_ADDR); 91 wday = rtc_read (RTC_DAY_REG_ADDR); 92 mday = rtc_read (RTC_DATE_REG_ADDR); 93 mon = rtc_read (RTC_MON_REG_ADDR); 94 year = rtc_read (RTC_YR_REG_ADDR); 95 96 DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x " 97 "hr: %02x min: %02x sec: %02x\n", 98 year, mon, mday, wday, hour, min, sec); 99 100 if (sec & RTC_SEC_BIT_CH) { 101 printf ("### Warning: RTC oscillator has stopped\n"); 102 /* clear the CH flag */ 103 rtc_write (RTC_SEC_REG_ADDR, 104 rtc_read (RTC_SEC_REG_ADDR) & ~RTC_SEC_BIT_CH); 105 rel = -1; 106 } 107 108 tmp->tm_sec = bcd2bin (sec & 0x7F); 109 tmp->tm_min = bcd2bin (min & 0x7F); 110 tmp->tm_hour = bcd2bin (hour & 0x3F); 111 tmp->tm_mday = bcd2bin (mday & 0x3F); 112 tmp->tm_mon = bcd2bin (mon & 0x1F); 113 tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000); 114 tmp->tm_wday = bcd2bin ((wday - 1) & 0x07); 115 tmp->tm_yday = 0; 116 tmp->tm_isdst= 0; 117 118 DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 119 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 120 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 121 122 return rel; 123 } 124 125 126 /* 127 * Set the RTC 128 */ 129 int rtc_set (struct rtc_time *tmp) 130 { 131 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 132 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 133 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 134 135 if (tmp->tm_year < 1970 || tmp->tm_year > 2069) 136 printf("WARNING: year should be between 1970 and 2069!\n"); 137 138 rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100)); 139 rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon)); 140 rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1)); 141 rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday)); 142 rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour)); 143 rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min)); 144 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec)); 145 146 return 0; 147 } 148 149 150 /* 151 * Reset the RTC. We setting the date back to 1970-01-01. 152 * We also enable the oscillator output on the SQW/OUT pin and program 153 * it for 32,768 Hz output. Note that according to the datasheet, turning 154 * on the square wave output increases the current drain on the backup 155 * battery to something between 480nA and 800nA. 156 */ 157 void rtc_reset (void) 158 { 159 struct rtc_time tmp; 160 161 rtc_write (RTC_SEC_REG_ADDR, 0x00); /* clearing Clock Halt */ 162 rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS0); 163 164 tmp.tm_year = 1970; 165 tmp.tm_mon = 1; 166 tmp.tm_mday= 1; 167 tmp.tm_hour = 0; 168 tmp.tm_min = 0; 169 tmp.tm_sec = 0; 170 171 rtc_set(&tmp); 172 173 printf ( "RTC: %4d-%02d-%02d %2d:%02d:%02d UTC\n", 174 tmp.tm_year, tmp.tm_mon, tmp.tm_mday, 175 tmp.tm_hour, tmp.tm_min, tmp.tm_sec); 176 177 return; 178 } 179 180 181 /* 182 * Helper functions 183 */ 184 185 static 186 uchar rtc_read (uchar reg) 187 { 188 return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg)); 189 } 190 191 192 static void rtc_write (uchar reg, uchar val) 193 { 194 i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val); 195 } 196 #endif 197