// SPDX-License-Identifier: GPL-2.0+

  /*
   * (C) Copyright 2001
   * ARIO Data Networks, Inc. dchiu@ariodata.com
   *
   * Based on MontaVista DS1743 code and U-Boot mc146818 code

   */
  
  /*
   * Date & Time support for the DS174x RTC
   */
  
  /*#define	DEBUG*/
  
  #include <common.h>
  #include <command.h>
  #include <rtc.h>

  static uchar rtc_read( unsigned int addr );
  static void  rtc_write( unsigned int addr, uchar val);

  #define RTC_BASE		( CONFIG_SYS_NVRAM_SIZE + CONFIG_SYS_NVRAM_BASE_ADDR )

  
  #define RTC_YEAR		( RTC_BASE + 7 )
  #define RTC_MONTH		( RTC_BASE + 6 )
  #define RTC_DAY_OF_MONTH	( RTC_BASE + 5 )
  #define RTC_DAY_OF_WEEK		( RTC_BASE + 4 )
  #define RTC_HOURS		( RTC_BASE + 3 )
  #define RTC_MINUTES		( RTC_BASE + 2 )
  #define RTC_SECONDS		( RTC_BASE + 1 )
  #define RTC_CENTURY		( RTC_BASE + 0 )
  
  #define RTC_CONTROLA		RTC_CENTURY
  #define RTC_CONTROLB		RTC_SECONDS
  #define RTC_CONTROLC		RTC_DAY_OF_WEEK
  
  #define RTC_CA_WRITE		0x80
  #define RTC_CA_READ		0x40
  
  #define RTC_CB_OSC_DISABLE	0x80
  
  #define RTC_CC_BATTERY_FLAG	0x80
  #define RTC_CC_FREQ_TEST	0x40
  
  /* ------------------------------------------------------------------------- */

  int rtc_get( struct rtc_time *tmp )

  {
  	uchar sec, min, hour;
  	uchar mday, wday, mon, year;
  
  	int century;
  
  	uchar reg_a;
  
  	reg_a = rtc_read( RTC_CONTROLA );
  	/* lock clock registers for read */
  	rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_READ ));
  
  	sec     = rtc_read( RTC_SECONDS );
  	min     = rtc_read( RTC_MINUTES );
  	hour    = rtc_read( RTC_HOURS );
  	mday    = rtc_read( RTC_DAY_OF_MONTH );
  	wday    = rtc_read( RTC_DAY_OF_WEEK );
  	mon     = rtc_read( RTC_MONTH );
  	year    = rtc_read( RTC_YEAR );
  	century = rtc_read( RTC_CENTURY );
  
  	/* unlock clock registers after read */
  	rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_READ ));
  
  #ifdef RTC_DEBUG
  	printf( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
  		"hr: %02x min: %02x sec: %02x
  ",
  		year, mon_cent, mday, wday,
  		hour, min, sec );
  #endif
  	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_wday = bcd2bin( wday & 0x07 );
  
  	/* glue year from century and year in century */
  	tmp->tm_year = bcd2bin( year ) +
  		( bcd2bin( century & 0x3F ) * 100 );
  
  	tmp->tm_yday = 0;
  	tmp->tm_isdst= 0;
  #ifdef RTC_DEBUG
  	printf( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d
  ",
  		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  		tmp->tm_hour, tmp->tm_min, tmp->tm_sec );
  #endif

  	return 0;

  }

  int rtc_set( struct rtc_time *tmp )

  {
  	uchar reg_a;
  #ifdef RTC_DEBUG
  	printf( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d
  ",
  		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  #endif
  	/* lock clock registers for write */
  	reg_a = rtc_read( RTC_CONTROLA );
  	rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_WRITE ));
  
  	rtc_write( RTC_MONTH, bin2bcd( tmp->tm_mon ));
  
  	rtc_write( RTC_DAY_OF_WEEK, bin2bcd( tmp->tm_wday ));
  	rtc_write( RTC_DAY_OF_MONTH, bin2bcd( tmp->tm_mday ));
  	rtc_write( RTC_HOURS, bin2bcd( tmp->tm_hour ));
  	rtc_write( RTC_MINUTES, bin2bcd( tmp->tm_min ));
  	rtc_write( RTC_SECONDS, bin2bcd( tmp->tm_sec ));
  
  	/* break year up into century and year in century */
  	rtc_write( RTC_YEAR, bin2bcd( tmp->tm_year % 100 ));
  	rtc_write( RTC_CENTURY, bin2bcd( tmp->tm_year / 100 ));
  
  	/* unlock clock registers after read */
  	rtc_write( RTC_CONTROLA, ( reg_a  & ~RTC_CA_WRITE ));

  
  	return 0;

  }
  
  void rtc_reset (void)
  {
  	uchar reg_a, reg_b, reg_c;
  
  	reg_a = rtc_read( RTC_CONTROLA );
  	reg_b = rtc_read( RTC_CONTROLB );
  
  	if ( reg_b & RTC_CB_OSC_DISABLE )
  	{
  		printf( "real-time-clock was stopped. Now starting...
  " );
  		reg_a |= RTC_CA_WRITE;
  		reg_b &= ~RTC_CB_OSC_DISABLE;
  
  		rtc_write( RTC_CONTROLA, reg_a );
  		rtc_write( RTC_CONTROLB, reg_b );
  	}
  
  	/* make sure read/write clock register bits are cleared */
  	reg_a &= ~( RTC_CA_WRITE | RTC_CA_READ );
  	rtc_write( RTC_CONTROLA, reg_a );
  
  	reg_c = rtc_read( RTC_CONTROLC );
  	if (( reg_c & RTC_CC_BATTERY_FLAG ) == 0 )
  		printf( "RTC battery low. Clock setting may not be reliable.
  " );
  }
  
  /* ------------------------------------------------------------------------- */
  
  static uchar rtc_read( unsigned int addr )
  {
  	uchar val = in8( addr );
  #ifdef RTC_DEBUG
  	printf( "rtc_read: %x:%x
  ", addr, val );
  #endif
  	return( val );
  }
  
  static void rtc_write( unsigned int addr, uchar val )
  {
  #ifdef RTC_DEBUG
  	printf( "rtc_write: %x:%x
  ", addr, val );
  #endif
  	out8( addr, val );
  }