1 /* 2 * (C) Copyright 2001-2008 3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4 * Keith Outwater, keith_outwater@mvis.com` 5 * 6 * See file CREDITS for list of people who contributed to this 7 * project. 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License as 11 * published by the Free Software Foundation; either version 2 of 12 * the License, or (at your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, write to the Free Software 21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 22 * MA 02111-1307 USA 23 */ 24 25 /* 26 * Date & Time support (no alarms) for Dallas Semiconductor (now Maxim) 27 * DS1337 Real Time Clock (RTC). 28 */ 29 30 #include <common.h> 31 #include <command.h> 32 #include <rtc.h> 33 #include <i2c.h> 34 35 #if defined(CONFIG_CMD_DATE) 36 37 /*---------------------------------------------------------------------*/ 38 #undef DEBUG_RTC 39 40 #ifdef DEBUG_RTC 41 #define DEBUGR(fmt,args...) printf(fmt ,##args) 42 #else 43 #define DEBUGR(fmt,args...) 44 #endif 45 /*---------------------------------------------------------------------*/ 46 47 /* 48 * RTC register addresses 49 */ 50 #define RTC_SEC_REG_ADDR 0x0 51 #define RTC_MIN_REG_ADDR 0x1 52 #define RTC_HR_REG_ADDR 0x2 53 #define RTC_DAY_REG_ADDR 0x3 54 #define RTC_DATE_REG_ADDR 0x4 55 #define RTC_MON_REG_ADDR 0x5 56 #define RTC_YR_REG_ADDR 0x6 57 #define RTC_CTL_REG_ADDR 0x0e 58 #define RTC_STAT_REG_ADDR 0x0f 59 #define RTC_TC_REG_ADDR 0x10 60 61 /* 62 * RTC control register bits 63 */ 64 #define RTC_CTL_BIT_A1IE 0x1 /* Alarm 1 interrupt enable */ 65 #define RTC_CTL_BIT_A2IE 0x2 /* Alarm 2 interrupt enable */ 66 #define RTC_CTL_BIT_INTCN 0x4 /* Interrupt control */ 67 #define RTC_CTL_BIT_RS1 0x8 /* Rate select 1 */ 68 #define RTC_CTL_BIT_RS2 0x10 /* Rate select 2 */ 69 #define RTC_CTL_BIT_DOSC 0x80 /* Disable Oscillator */ 70 71 /* 72 * RTC status register bits 73 */ 74 #define RTC_STAT_BIT_A1F 0x1 /* Alarm 1 flag */ 75 #define RTC_STAT_BIT_A2F 0x2 /* Alarm 2 flag */ 76 #define RTC_STAT_BIT_OSF 0x80 /* Oscillator stop flag */ 77 78 79 static uchar rtc_read (uchar reg); 80 static void rtc_write (uchar reg, uchar val); 81 82 /* 83 * Get the current time from the RTC 84 */ 85 int rtc_get (struct rtc_time *tmp) 86 { 87 int rel = 0; 88 uchar sec, min, hour, mday, wday, mon_cent, year, control, status; 89 90 control = rtc_read (RTC_CTL_REG_ADDR); 91 status = rtc_read (RTC_STAT_REG_ADDR); 92 sec = rtc_read (RTC_SEC_REG_ADDR); 93 min = rtc_read (RTC_MIN_REG_ADDR); 94 hour = rtc_read (RTC_HR_REG_ADDR); 95 wday = rtc_read (RTC_DAY_REG_ADDR); 96 mday = rtc_read (RTC_DATE_REG_ADDR); 97 mon_cent = rtc_read (RTC_MON_REG_ADDR); 98 year = rtc_read (RTC_YR_REG_ADDR); 99 100 DEBUGR ("Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x " 101 "hr: %02x min: %02x sec: %02x control: %02x status: %02x\n", 102 year, mon_cent, mday, wday, hour, min, sec, control, status); 103 104 if (status & RTC_STAT_BIT_OSF) { 105 printf ("### Warning: RTC oscillator has stopped\n"); 106 /* clear the OSF flag */ 107 rtc_write (RTC_STAT_REG_ADDR, 108 rtc_read (RTC_STAT_REG_ADDR) & ~RTC_STAT_BIT_OSF); 109 rel = -1; 110 } 111 112 tmp->tm_sec = bcd2bin (sec & 0x7F); 113 tmp->tm_min = bcd2bin (min & 0x7F); 114 tmp->tm_hour = bcd2bin (hour & 0x3F); 115 tmp->tm_mday = bcd2bin (mday & 0x3F); 116 tmp->tm_mon = bcd2bin (mon_cent & 0x1F); 117 tmp->tm_year = bcd2bin (year) + ((mon_cent & 0x80) ? 2000 : 1900); 118 tmp->tm_wday = bcd2bin ((wday - 1) & 0x07); 119 tmp->tm_yday = 0; 120 tmp->tm_isdst= 0; 121 122 DEBUGR ("Get 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); 125 126 return rel; 127 } 128 129 130 /* 131 * Set the RTC 132 */ 133 int rtc_set (struct rtc_time *tmp) 134 { 135 uchar century; 136 137 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 138 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 139 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 140 141 rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100)); 142 143 century = (tmp->tm_year >= 2000) ? 0x80 : 0; 144 rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon) | century); 145 146 rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1)); 147 rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday)); 148 rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour)); 149 rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min)); 150 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec)); 151 152 return 0; 153 } 154 155 156 /* 157 * Reset the RTC. We also enable the oscillator output on the 158 * SQW/INTB* pin and program it for 32,768 Hz output. Note that 159 * according to the datasheet, turning on the square wave output 160 * increases the current drain on the backup battery from about 161 * 600 nA to 2uA. Define CONFIG_SYS_RTC_DS1337_NOOSC if you wish to turn 162 * off the OSC output. 163 */ 164 #ifdef CONFIG_SYS_RTC_DS1337_NOOSC 165 #define RTC_DS1337_RESET_VAL \ 166 (RTC_CTL_BIT_INTCN | RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS2) 167 #else 168 #define RTC_DS1337_RESET_VAL (RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS2) 169 #endif 170 void rtc_reset (void) 171 { 172 rtc_write (RTC_CTL_REG_ADDR, RTC_DS1337_RESET_VAL); 173 #ifdef CONFIG_SYS_DS1339_TCR_VAL 174 rtc_write (RTC_TC_REG_ADDR, CONFIG_SYS_DS1339_TCR_VAL); 175 #endif 176 } 177 178 179 /* 180 * Helper functions 181 */ 182 183 static 184 uchar rtc_read (uchar reg) 185 { 186 return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg)); 187 } 188 189 190 static void rtc_write (uchar reg, uchar val) 191 { 192 i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val); 193 } 194 195 #endif 196