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 60 /* 61 * RTC control register bits 62 */ 63 #define RTC_CTL_BIT_A1IE 0x1 /* Alarm 1 interrupt enable */ 64 #define RTC_CTL_BIT_A2IE 0x2 /* Alarm 2 interrupt enable */ 65 #define RTC_CTL_BIT_INTCN 0x4 /* Interrupt control */ 66 #define RTC_CTL_BIT_RS1 0x8 /* Rate select 1 */ 67 #define RTC_CTL_BIT_RS2 0x10 /* Rate select 2 */ 68 #define RTC_CTL_BIT_DOSC 0x80 /* Disable Oscillator */ 69 70 /* 71 * RTC status register bits 72 */ 73 #define RTC_STAT_BIT_A1F 0x1 /* Alarm 1 flag */ 74 #define RTC_STAT_BIT_A2F 0x2 /* Alarm 2 flag */ 75 #define RTC_STAT_BIT_OSF 0x80 /* Oscillator stop flag */ 76 77 78 static uchar rtc_read (uchar reg); 79 static void rtc_write (uchar reg, uchar val); 80 81 /* 82 * Get the current time from the RTC 83 */ 84 int rtc_get (struct rtc_time *tmp) 85 { 86 int rel = 0; 87 uchar sec, min, hour, mday, wday, mon_cent, year, control, status; 88 89 control = rtc_read (RTC_CTL_REG_ADDR); 90 status = rtc_read (RTC_STAT_REG_ADDR); 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_cent = rtc_read (RTC_MON_REG_ADDR); 97 year = rtc_read (RTC_YR_REG_ADDR); 98 99 DEBUGR ("Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x " 100 "hr: %02x min: %02x sec: %02x control: %02x status: %02x\n", 101 year, mon_cent, mday, wday, hour, min, sec, control, status); 102 103 if (status & RTC_STAT_BIT_OSF) { 104 printf ("### Warning: RTC oscillator has stopped\n"); 105 /* clear the OSF flag */ 106 rtc_write (RTC_STAT_REG_ADDR, 107 rtc_read (RTC_STAT_REG_ADDR) & ~RTC_STAT_BIT_OSF); 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_cent & 0x1F); 116 tmp->tm_year = bcd2bin (year) + ((mon_cent & 0x80) ? 2000 : 1900); 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 int rtc_set (struct rtc_time *tmp) 133 { 134 uchar century; 135 136 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 137 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 138 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 139 140 rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100)); 141 142 century = (tmp->tm_year >= 2000) ? 0x80 : 0; 143 rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon) | century); 144 145 rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1)); 146 rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday)); 147 rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour)); 148 rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min)); 149 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec)); 150 151 return 0; 152 } 153 154 155 /* 156 * Reset the RTC. We also enable the oscillator output on the 157 * SQW/INTB* pin and program it for 32,768 Hz output. Note that 158 * according to the datasheet, turning on the square wave output 159 * increases the current drain on the backup battery from about 160 * 600 nA to 2uA. Define CONFIG_SYS_RTC_DS1337_NOOSC if you wish to turn 161 * off the OSC output. 162 */ 163 #ifdef CONFIG_SYS_RTC_DS1337_NOOSC 164 #define RTC_DS1337_RESET_VAL \ 165 (RTC_CTL_BIT_INTCN | RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS2) 166 #else 167 #define RTC_DS1337_RESET_VAL (RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS2) 168 #endif 169 void rtc_reset (void) 170 { 171 rtc_write (RTC_CTL_REG_ADDR, RTC_DS1337_RESET_VAL); 172 } 173 174 175 /* 176 * Helper functions 177 */ 178 179 static 180 uchar rtc_read (uchar reg) 181 { 182 return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg)); 183 } 184 185 186 static void rtc_write (uchar reg, uchar val) 187 { 188 i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val); 189 } 190 191 #endif 192