text: /*
   * (C) Copyright 2001
   * Wolfgang Denk, DENX Software Engineering, wd@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 for Philips PCF8563 RTC
   */
  
  /* #define	DEBUG	*/
  
  #include <common.h>
  #include <command.h>
  #include <rtc.h>
  #include <i2c.h>
  
  #if defined(CONFIG_CMD_DATE)
  
  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);
  
  /* ------------------------------------------------------------------------- */
  
  int rtc_get (struct rtc_time *tmp)
  {
  	int rel = 0;
  	uchar sec, min, hour, mday, wday, mon_cent, year;
  
  	sec	= rtc_read (0x02);
  	min	= rtc_read (0x03);
  	hour	= rtc_read (0x04);
  	mday	= rtc_read (0x05);
  	wday	= rtc_read (0x06);
  	mon_cent= rtc_read (0x07);
  	year	= rtc_read (0x08);
  
  	debug ( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
  		"hr: %02x min: %02x sec: %02x\n",
  		year, mon_cent, mday, wday,
  		hour, min, sec );
  	debug ( "Alarms: wday: %02x day: %02x hour: %02x min: %02x\n",
  		rtc_read (0x0C),
  		rtc_read (0x0B),
  		rtc_read (0x0A),
  		rtc_read (0x09) );
  
  	if (sec & 0x80) {
  		puts ("### Warning: RTC Low Voltage - date/time not reliable\n");
  		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_cent & 0x1F);
  	tmp->tm_year = bcd2bin (year) + ((mon_cent & 0x80) ? 2000 : 1900);
  	tmp->tm_wday = bcd2bin (wday & 0x07);
  	tmp->tm_yday = 0;
  	tmp->tm_isdst= 0;
  
  	debug ( "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;
  }
  
  int rtc_set (struct rtc_time *tmp)
  {
  	uchar century;
  
  	debug ( "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 (0x08, bin2bcd(tmp->tm_year % 100));
  
  	century = (tmp->tm_year >= 2000) ? 0x80 : 0;
  	rtc_write (0x07, bin2bcd(tmp->tm_mon) | century);
  
  	rtc_write (0x06, bin2bcd(tmp->tm_wday));
  	rtc_write (0x05, bin2bcd(tmp->tm_mday));
  	rtc_write (0x04, bin2bcd(tmp->tm_hour));
  	rtc_write (0x03, bin2bcd(tmp->tm_min ));
  	rtc_write (0x02, bin2bcd(tmp->tm_sec ));
  
  	return 0;
  }
  
  void rtc_reset (void)
  {
  	/* clear all control & status registers */
  	rtc_write (0x00, 0x00);
  	rtc_write (0x01, 0x00);
  	rtc_write (0x0D, 0x00);
  
  	/* clear Voltage Low bit */
  	rtc_write (0x02, rtc_read (0x02) & 0x7F);
  
  	/* reset all alarms */
  	rtc_write (0x09, 0x00);
  	rtc_write (0x0A, 0x00);
  	rtc_write (0x0B, 0x00);
  	rtc_write (0x0C, 0x00);
  }
  
  /* ------------------------------------------------------------------------- */
  
  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);
  }
  
  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
  