1 /* 2 * (C) Copyright 2006 3 * Markus Klotzbuecher, mk@denx.de 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 (no alarms) for Dallas Semiconductor (now Maxim) 26 * Extremly Accurate DS3231 Real Time Clock (RTC). 27 * 28 * copied from ds1337.c 29 */ 30 31 #include <common.h> 32 #include <command.h> 33 #include <rtc.h> 34 #include <i2c.h> 35 36 #if defined(CONFIG_CMD_DATE) 37 38 /*---------------------------------------------------------------------*/ 39 #undef DEBUG_RTC 40 41 #ifdef DEBUG_RTC 42 #define DEBUGR(fmt,args...) printf(fmt ,##args) 43 #else 44 #define DEBUGR(fmt,args...) 45 #endif 46 /*---------------------------------------------------------------------*/ 47 48 /* 49 * RTC register addresses 50 */ 51 #define RTC_SEC_REG_ADDR 0x0 52 #define RTC_MIN_REG_ADDR 0x1 53 #define RTC_HR_REG_ADDR 0x2 54 #define RTC_DAY_REG_ADDR 0x3 55 #define RTC_DATE_REG_ADDR 0x4 56 #define RTC_MON_REG_ADDR 0x5 57 #define RTC_YR_REG_ADDR 0x6 58 #define RTC_CTL_REG_ADDR 0x0e 59 #define RTC_STAT_REG_ADDR 0x0f 60 61 62 /* 63 * RTC control register bits 64 */ 65 #define RTC_CTL_BIT_A1IE 0x1 /* Alarm 1 interrupt enable */ 66 #define RTC_CTL_BIT_A2IE 0x2 /* Alarm 2 interrupt enable */ 67 #define RTC_CTL_BIT_INTCN 0x4 /* Interrupt control */ 68 #define RTC_CTL_BIT_RS1 0x8 /* Rate select 1 */ 69 #define RTC_CTL_BIT_RS2 0x10 /* Rate select 2 */ 70 #define RTC_CTL_BIT_DOSC 0x80 /* Disable Oscillator */ 71 72 /* 73 * RTC status register bits 74 */ 75 #define RTC_STAT_BIT_A1F 0x1 /* Alarm 1 flag */ 76 #define RTC_STAT_BIT_A2F 0x2 /* Alarm 2 flag */ 77 #define RTC_STAT_BIT_OSF 0x80 /* Oscillator stop flag */ 78 79 80 static uchar rtc_read (uchar reg); 81 static void rtc_write (uchar reg, uchar val); 82 83 84 /* 85 * Get the current time from the RTC 86 */ 87 int rtc_get (struct rtc_time *tmp) 88 { 89 int rel = 0; 90 uchar sec, min, hour, mday, wday, mon_cent, year, control, status; 91 92 control = rtc_read (RTC_CTL_REG_ADDR); 93 status = rtc_read (RTC_STAT_REG_ADDR); 94 sec = rtc_read (RTC_SEC_REG_ADDR); 95 min = rtc_read (RTC_MIN_REG_ADDR); 96 hour = rtc_read (RTC_HR_REG_ADDR); 97 wday = rtc_read (RTC_DAY_REG_ADDR); 98 mday = rtc_read (RTC_DATE_REG_ADDR); 99 mon_cent = rtc_read (RTC_MON_REG_ADDR); 100 year = rtc_read (RTC_YR_REG_ADDR); 101 102 DEBUGR ("Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x " 103 "hr: %02x min: %02x sec: %02x control: %02x status: %02x\n", 104 year, mon_cent, mday, wday, hour, min, sec, control, status); 105 106 if (status & RTC_STAT_BIT_OSF) { 107 printf ("### Warning: RTC oscillator has stopped\n"); 108 /* clear the OSF flag */ 109 rtc_write (RTC_STAT_REG_ADDR, 110 rtc_read (RTC_STAT_REG_ADDR) & ~RTC_STAT_BIT_OSF); 111 rel = -1; 112 } 113 114 tmp->tm_sec = bcd2bin (sec & 0x7F); 115 tmp->tm_min = bcd2bin (min & 0x7F); 116 tmp->tm_hour = bcd2bin (hour & 0x3F); 117 tmp->tm_mday = bcd2bin (mday & 0x3F); 118 tmp->tm_mon = bcd2bin (mon_cent & 0x1F); 119 tmp->tm_year = bcd2bin (year) + ((mon_cent & 0x80) ? 2000 : 1900); 120 tmp->tm_wday = bcd2bin ((wday - 1) & 0x07); 121 tmp->tm_yday = 0; 122 tmp->tm_isdst= 0; 123 124 DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 125 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 126 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 127 128 return rel; 129 } 130 131 132 /* 133 * Set the RTC 134 */ 135 int rtc_set (struct rtc_time *tmp) 136 { 137 uchar century; 138 139 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 140 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 141 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 142 143 rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100)); 144 145 century = (tmp->tm_year >= 2000) ? 0x80 : 0; 146 rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon) | century); 147 148 rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1)); 149 rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday)); 150 rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour)); 151 rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min)); 152 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec)); 153 154 return 0; 155 } 156 157 158 /* 159 * Reset the RTC. We also enable the oscillator output on the 160 * SQW/INTB* pin and program it for 32,768 Hz output. Note that 161 * according to the datasheet, turning on the square wave output 162 * increases the current drain on the backup battery from about 163 * 600 nA to 2uA. 164 */ 165 void rtc_reset (void) 166 { 167 rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS2); 168 } 169 170 171 /* 172 * Helper functions 173 */ 174 175 static 176 uchar rtc_read (uchar reg) 177 { 178 return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg)); 179 } 180 181 182 static void rtc_write (uchar reg, uchar val) 183 { 184 i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val); 185 } 186 187 #endif 188