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 * SPDX-License-Identifier: GPL-2.0+ 8 */ 9 10 /* 11 * Date & Time support (no alarms) for Dallas Semiconductor (now Maxim) 12 * DS1307 and DS1338/9 Real Time Clock (RTC). 13 * 14 * based on ds1337.c 15 */ 16 17 #include <common.h> 18 #include <command.h> 19 #include <rtc.h> 20 #include <i2c.h> 21 22 #if defined(CONFIG_CMD_DATE) 23 24 /*---------------------------------------------------------------------*/ 25 #undef DEBUG_RTC 26 27 #ifdef DEBUG_RTC 28 #define DEBUGR(fmt,args...) printf(fmt ,##args) 29 #else 30 #define DEBUGR(fmt,args...) 31 #endif 32 /*---------------------------------------------------------------------*/ 33 34 #ifndef CONFIG_SYS_I2C_RTC_ADDR 35 # define CONFIG_SYS_I2C_RTC_ADDR 0x68 36 #endif 37 38 #if defined(CONFIG_RTC_DS1307) && (CONFIG_SYS_I2C_SPEED > 100000) 39 # error The DS1307 is specified only up to 100kHz! 40 #endif 41 42 /* 43 * RTC register addresses 44 */ 45 #define RTC_SEC_REG_ADDR 0x00 46 #define RTC_MIN_REG_ADDR 0x01 47 #define RTC_HR_REG_ADDR 0x02 48 #define RTC_DAY_REG_ADDR 0x03 49 #define RTC_DATE_REG_ADDR 0x04 50 #define RTC_MON_REG_ADDR 0x05 51 #define RTC_YR_REG_ADDR 0x06 52 #define RTC_CTL_REG_ADDR 0x07 53 54 #define RTC_SEC_BIT_CH 0x80 /* Clock Halt (in Register 0) */ 55 56 #define RTC_CTL_BIT_RS0 0x01 /* Rate select 0 */ 57 #define RTC_CTL_BIT_RS1 0x02 /* Rate select 1 */ 58 #define RTC_CTL_BIT_SQWE 0x10 /* Square Wave Enable */ 59 #define RTC_CTL_BIT_OUT 0x80 /* Output Control */ 60 61 static uchar rtc_read (uchar reg); 62 static void rtc_write (uchar reg, uchar val); 63 64 /* 65 * Get the current time from the RTC 66 */ 67 int rtc_get (struct rtc_time *tmp) 68 { 69 int rel = 0; 70 uchar sec, min, hour, mday, wday, mon, year; 71 72 sec = rtc_read (RTC_SEC_REG_ADDR); 73 min = rtc_read (RTC_MIN_REG_ADDR); 74 hour = rtc_read (RTC_HR_REG_ADDR); 75 wday = rtc_read (RTC_DAY_REG_ADDR); 76 mday = rtc_read (RTC_DATE_REG_ADDR); 77 mon = rtc_read (RTC_MON_REG_ADDR); 78 year = rtc_read (RTC_YR_REG_ADDR); 79 80 DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x " 81 "hr: %02x min: %02x sec: %02x\n", 82 year, mon, mday, wday, hour, min, sec); 83 84 if (sec & RTC_SEC_BIT_CH) { 85 printf ("### Warning: RTC oscillator has stopped\n"); 86 /* clear the CH flag */ 87 rtc_write (RTC_SEC_REG_ADDR, 88 rtc_read (RTC_SEC_REG_ADDR) & ~RTC_SEC_BIT_CH); 89 rel = -1; 90 } 91 92 tmp->tm_sec = bcd2bin (sec & 0x7F); 93 tmp->tm_min = bcd2bin (min & 0x7F); 94 tmp->tm_hour = bcd2bin (hour & 0x3F); 95 tmp->tm_mday = bcd2bin (mday & 0x3F); 96 tmp->tm_mon = bcd2bin (mon & 0x1F); 97 tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000); 98 tmp->tm_wday = bcd2bin ((wday - 1) & 0x07); 99 tmp->tm_yday = 0; 100 tmp->tm_isdst= 0; 101 102 DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 103 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 104 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 105 106 return rel; 107 } 108 109 110 /* 111 * Set the RTC 112 */ 113 int rtc_set (struct rtc_time *tmp) 114 { 115 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 116 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 117 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 118 119 if (tmp->tm_year < 1970 || tmp->tm_year > 2069) 120 printf("WARNING: year should be between 1970 and 2069!\n"); 121 122 rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100)); 123 rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon)); 124 rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1)); 125 rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday)); 126 rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour)); 127 rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min)); 128 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec)); 129 130 return 0; 131 } 132 133 134 /* 135 * Reset the RTC. We setting the date back to 1970-01-01. 136 * We also enable the oscillator output on the SQW/OUT pin and program 137 * it for 32,768 Hz output. Note that according to the datasheet, turning 138 * on the square wave output increases the current drain on the backup 139 * battery to something between 480nA and 800nA. 140 */ 141 void rtc_reset (void) 142 { 143 struct rtc_time tmp; 144 145 rtc_write (RTC_SEC_REG_ADDR, 0x00); /* clearing Clock Halt */ 146 rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS0); 147 148 tmp.tm_year = 1970; 149 tmp.tm_mon = 1; 150 tmp.tm_mday= 1; 151 tmp.tm_hour = 0; 152 tmp.tm_min = 0; 153 tmp.tm_sec = 0; 154 155 rtc_set(&tmp); 156 157 printf ( "RTC: %4d-%02d-%02d %2d:%02d:%02d UTC\n", 158 tmp.tm_year, tmp.tm_mon, tmp.tm_mday, 159 tmp.tm_hour, tmp.tm_min, tmp.tm_sec); 160 161 return; 162 } 163 164 165 /* 166 * Helper functions 167 */ 168 169 static 170 uchar rtc_read (uchar reg) 171 { 172 return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg)); 173 } 174 175 176 static void rtc_write (uchar reg, uchar val) 177 { 178 i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val); 179 } 180 #endif 181