/* * (C) Copyright 2006 * Markus Klotzbuecher, mk@denx.de * * See file CREDITS for list of people who contributed to this * project. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of * the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, * MA 02111-1307 USA *//* * Date & Time support (no alarms) for Dallas Semiconductor (now Maxim) * Extremly Accurate DS3231 Real Time Clock (RTC). * * copied from ds1337.c */#include <common.h>#include <command.h>#include <rtc.h>#include <i2c.h>#if defined(CONFIG_RTC_DS3231) && defined(CONFIG_CMD_DATE)/*---------------------------------------------------------------------*/#undef DEBUG_RTC#ifdef DEBUG_RTC#define DEBUGR(fmt,args...) printf(fmt ,##args)#else#define DEBUGR(fmt,args...)#endif/*---------------------------------------------------------------------*//* * RTC register addresses */#define RTC_SEC_REG_ADDR	0x0#define RTC_MIN_REG_ADDR	0x1#define RTC_HR_REG_ADDR		0x2#define RTC_DAY_REG_ADDR	0x3#define RTC_DATE_REG_ADDR	0x4#define RTC_MON_REG_ADDR	0x5#define RTC_YR_REG_ADDR		0x6#define RTC_CTL_REG_ADDR	0x0e#define RTC_STAT_REG_ADDR	0x0f/* * RTC control register bits */#define RTC_CTL_BIT_A1IE	0x1	/* Alarm 1 interrupt enable     */#define RTC_CTL_BIT_A2IE	0x2	/* Alarm 2 interrupt enable     */#define RTC_CTL_BIT_INTCN	0x4	/* Interrupt control            */#define RTC_CTL_BIT_RS1		0x8	/* Rate select 1                */#define RTC_CTL_BIT_RS2		0x10	/* Rate select 2                */#define RTC_CTL_BIT_DOSC	0x80	/* Disable Oscillator           *//* * RTC status register bits */#define RTC_STAT_BIT_A1F	0x1	/* Alarm 1 flag                 */#define RTC_STAT_BIT_A2F	0x2	/* Alarm 2 flag                 */#define RTC_STAT_BIT_OSF	0x80	/* Oscillator stop flag         */static uchar rtc_read (uchar reg);static void rtc_write (uchar reg, uchar val);static uchar bin2bcd (unsigned int n);static unsigned bcd2bin (uchar c);/* * Get the current time from the RTC */void rtc_get (struct rtc_time *tmp){	uchar sec, min, hour, mday, wday, mon_cent, year, control, status;	control = rtc_read (RTC_CTL_REG_ADDR);	status = rtc_read (RTC_STAT_REG_ADDR);	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_cent = rtc_read (RTC_MON_REG_ADDR);	year = rtc_read (RTC_YR_REG_ADDR);	DEBUGR ("Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "		"hr: %02x min: %02x sec: %02x control: %02x status: %02x\n",		year, mon_cent, mday, wday, hour, min, sec, control, status);	if (status & RTC_STAT_BIT_OSF) {		printf ("### Warning: RTC oscillator has stopped\n");		/* clear the OSF flag */		rtc_write (RTC_STAT_REG_ADDR,			   rtc_read (RTC_STAT_REG_ADDR) & ~RTC_STAT_BIT_OSF);	}	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_cent & 0x1F);	tmp->tm_year = bcd2bin (year) + ((mon_cent & 0x80) ? 2000 : 1900);	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);}/* * Set the RTC */void rtc_set (struct rtc_time *tmp){	uchar century;	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);	rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));	century = (tmp->tm_year >= 2000) ? 0x80 : 0;	rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon) | century);	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));}/* * Reset the RTC.  We also enable the oscillator output on the * SQW/INTB* 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 from about * 600 nA to 2uA. */void rtc_reset (void){	rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS2);}/* * Helper functions */staticuchar rtc_read (uchar reg){	return (i2c_reg_read (CFG_I2C_RTC_ADDR, reg));}static void rtc_write (uchar reg, uchar val){	i2c_reg_write (CFG_I2C_RTC_ADDR, reg, val);}static unsigned bcd2bin (uchar n){	return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));}static unsigned char bin2bcd (unsigned int n){	return (((n / 10) << 4) | (n % 10));}#endif