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 /* MCP7941X-specific bits */ 62 #define MCP7941X_BIT_ST 0x80 63 #define MCP7941X_BIT_VBATEN 0x08 64 65 static uchar rtc_read (uchar reg); 66 static void rtc_write (uchar reg, uchar val); 67 68 /* 69 * Get the current time from the RTC 70 */ 71 int rtc_get (struct rtc_time *tmp) 72 { 73 int rel = 0; 74 uchar sec, min, hour, mday, wday, mon, year; 75 76 #ifdef CONFIG_RTC_MCP79411 77 read_rtc: 78 #endif 79 sec = rtc_read (RTC_SEC_REG_ADDR); 80 min = rtc_read (RTC_MIN_REG_ADDR); 81 hour = rtc_read (RTC_HR_REG_ADDR); 82 wday = rtc_read (RTC_DAY_REG_ADDR); 83 mday = rtc_read (RTC_DATE_REG_ADDR); 84 mon = rtc_read (RTC_MON_REG_ADDR); 85 year = rtc_read (RTC_YR_REG_ADDR); 86 87 DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x " 88 "hr: %02x min: %02x sec: %02x\n", 89 year, mon, mday, wday, hour, min, sec); 90 91 #ifdef CONFIG_RTC_DS1307 92 if (sec & RTC_SEC_BIT_CH) { 93 printf ("### Warning: RTC oscillator has stopped\n"); 94 /* clear the CH flag */ 95 rtc_write (RTC_SEC_REG_ADDR, 96 rtc_read (RTC_SEC_REG_ADDR) & ~RTC_SEC_BIT_CH); 97 rel = -1; 98 } 99 #endif 100 101 #ifdef CONFIG_RTC_MCP79411 102 /* make sure that the backup battery is enabled */ 103 if (!(wday & MCP7941X_BIT_VBATEN)) { 104 rtc_write(RTC_DAY_REG_ADDR, 105 wday | MCP7941X_BIT_VBATEN); 106 } 107 108 /* clock halted? turn it on, so clock can tick. */ 109 if (!(sec & MCP7941X_BIT_ST)) { 110 rtc_write(RTC_SEC_REG_ADDR, MCP7941X_BIT_ST); 111 printf("Started RTC\n"); 112 goto read_rtc; 113 } 114 #endif 115 116 117 tmp->tm_sec = bcd2bin (sec & 0x7F); 118 tmp->tm_min = bcd2bin (min & 0x7F); 119 tmp->tm_hour = bcd2bin (hour & 0x3F); 120 tmp->tm_mday = bcd2bin (mday & 0x3F); 121 tmp->tm_mon = bcd2bin (mon & 0x1F); 122 tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000); 123 tmp->tm_wday = bcd2bin ((wday - 1) & 0x07); 124 tmp->tm_yday = 0; 125 tmp->tm_isdst= 0; 126 127 DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 128 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 129 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 130 131 return rel; 132 } 133 134 135 /* 136 * Set the RTC 137 */ 138 int rtc_set (struct rtc_time *tmp) 139 { 140 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 141 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 142 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 143 144 if (tmp->tm_year < 1970 || tmp->tm_year > 2069) 145 printf("WARNING: year should be between 1970 and 2069!\n"); 146 147 rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100)); 148 rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon)); 149 #ifdef CONFIG_RTC_MCP79411 150 rtc_write (RTC_DAY_REG_ADDR, 151 bin2bcd (tmp->tm_wday + 1) | MCP7941X_BIT_VBATEN); 152 #else 153 rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1)); 154 #endif 155 rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday)); 156 rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour)); 157 rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min)); 158 #ifdef CONFIG_RTC_MCP79411 159 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec) | MCP7941X_BIT_ST); 160 #else 161 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec)); 162 #endif 163 164 return 0; 165 } 166 167 168 /* 169 * Reset the RTC. We setting the date back to 1970-01-01. 170 * We also enable the oscillator output on the SQW/OUT pin and program 171 * it for 32,768 Hz output. Note that according to the datasheet, turning 172 * on the square wave output increases the current drain on the backup 173 * battery to something between 480nA and 800nA. 174 */ 175 void rtc_reset (void) 176 { 177 struct rtc_time tmp; 178 179 rtc_write (RTC_SEC_REG_ADDR, 0x00); /* clearing Clock Halt */ 180 rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS0); 181 182 tmp.tm_year = 1970; 183 tmp.tm_mon = 1; 184 tmp.tm_mday= 1; 185 tmp.tm_hour = 0; 186 tmp.tm_min = 0; 187 tmp.tm_sec = 0; 188 189 rtc_set(&tmp); 190 191 printf ( "RTC: %4d-%02d-%02d %2d:%02d:%02d UTC\n", 192 tmp.tm_year, tmp.tm_mon, tmp.tm_mday, 193 tmp.tm_hour, tmp.tm_min, tmp.tm_sec); 194 195 return; 196 } 197 198 199 /* 200 * Helper functions 201 */ 202 203 static 204 uchar rtc_read (uchar reg) 205 { 206 return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg)); 207 } 208 209 210 static void rtc_write (uchar reg, uchar val) 211 { 212 i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val); 213 } 214 #endif 215