/* * (C) Copyright 2001, 2002, 2003 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. * Keith Outwater, keith_outwater@mvis.com` * Steven Scholz, steven.scholz@imc-berlin.de * * SPDX-License-Identifier: GPL-2.0+ */ /* * Date & Time support (no alarms) for Dallas Semiconductor (now Maxim) * DS1307 and DS1338/9 Real Time Clock (RTC). * * based on ds1337.c */ #include <common.h> #include <command.h> #include <rtc.h> #include <i2c.h> #if defined(CONFIG_CMD_DATE) /*---------------------------------------------------------------------*/ #undef DEBUG_RTC #ifdef DEBUG_RTC #define DEBUGR(fmt,args...) printf(fmt ,##args) #else #define DEBUGR(fmt,args...) #endif /*---------------------------------------------------------------------*/ #ifndef CONFIG_SYS_I2C_RTC_ADDR # define CONFIG_SYS_I2C_RTC_ADDR 0x68 #endif #if defined(CONFIG_RTC_DS1307) && (CONFIG_SYS_I2C_SPEED > 100000) # error The DS1307 is specified only up to 100kHz! #endif /* * RTC register addresses */ #define RTC_SEC_REG_ADDR 0x00 #define RTC_MIN_REG_ADDR 0x01 #define RTC_HR_REG_ADDR 0x02 #define RTC_DAY_REG_ADDR 0x03 #define RTC_DATE_REG_ADDR 0x04 #define RTC_MON_REG_ADDR 0x05 #define RTC_YR_REG_ADDR 0x06 #define RTC_CTL_REG_ADDR 0x07 #define RTC_SEC_BIT_CH 0x80 /* Clock Halt (in Register 0) */ #define RTC_CTL_BIT_RS0 0x01 /* Rate select 0 */ #define RTC_CTL_BIT_RS1 0x02 /* Rate select 1 */ #define RTC_CTL_BIT_SQWE 0x10 /* Square Wave Enable */ #define RTC_CTL_BIT_OUT 0x80 /* Output Control */ static uchar rtc_read (uchar reg); static void rtc_write (uchar reg, uchar val); /* * Get the current time from the RTC */ int rtc_get (struct rtc_time *tmp) { int rel = 0; uchar sec, min, hour, mday, wday, mon, year; sec = rtc_read (RTC_SEC_REG_ADDR); min = rtc_read (RTC_MIN_REG_ADDR); hour = rtc_read (RTC_HR_REG_ADDR); wday = rtc_read (RTC_DAY_REG_ADDR); mday = rtc_read (RTC_DATE_REG_ADDR); mon = rtc_read (RTC_MON_REG_ADDR); year = rtc_read (RTC_YR_REG_ADDR); DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x " "hr: %02x min: %02x sec: %02x\n", year, mon, mday, wday, hour, min, sec); if (sec & RTC_SEC_BIT_CH) { printf ("### Warning: RTC oscillator has stopped\n"); /* clear the CH flag */ rtc_write (RTC_SEC_REG_ADDR, rtc_read (RTC_SEC_REG_ADDR) & ~RTC_SEC_BIT_CH); rel = -1; } tmp->tm_sec = bcd2bin (sec & 0x7F); tmp->tm_min = bcd2bin (min & 0x7F); tmp->tm_hour = bcd2bin (hour & 0x3F); tmp->tm_mday = bcd2bin (mday & 0x3F); tmp->tm_mon = bcd2bin (mon & 0x1F); tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000); tmp->tm_wday = bcd2bin ((wday - 1) & 0x07); tmp->tm_yday = 0; tmp->tm_isdst= 0; DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, tmp->tm_hour, tmp->tm_min, tmp->tm_sec); return rel; } /* * Set the RTC */ int rtc_set (struct rtc_time *tmp) { DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, tmp->tm_hour, tmp->tm_min, tmp->tm_sec); if (tmp->tm_year < 1970 || tmp->tm_year > 2069) printf("WARNING: year should be between 1970 and 2069!\n"); rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100)); rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon)); rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1)); rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday)); rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour)); rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min)); rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec)); return 0; } /* * Reset the RTC. We setting the date back to 1970-01-01. * We also enable the oscillator output on the SQW/OUT pin and program * it for 32,768 Hz output. Note that according to the datasheet, turning * on the square wave output increases the current drain on the backup * battery to something between 480nA and 800nA. */ void rtc_reset (void) { struct rtc_time tmp; rtc_write (RTC_SEC_REG_ADDR, 0x00); /* clearing Clock Halt */ rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS0); tmp.tm_year = 1970; tmp.tm_mon = 1; tmp.tm_mday= 1; tmp.tm_hour = 0; tmp.tm_min = 0; tmp.tm_sec = 0; rtc_set(&tmp); printf ( "RTC: %4d-%02d-%02d %2d:%02d:%02d UTC\n", tmp.tm_year, tmp.tm_mon, tmp.tm_mday, tmp.tm_hour, tmp.tm_min, tmp.tm_sec); return; } /* * Helper functions */ static uchar rtc_read (uchar reg) { return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg)); } static void rtc_write (uchar reg, uchar val) { i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val); } #endif