/*
   * (C) Copyright 2002
   * Andrew May, Viasat Inc, amay@viasat.com
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  /*
   * M41T11 Serial Access Timekeeper(R) SRAM
   * can you believe a trademark on that?
   */
  
  /* #define DEBUG 1 */
  
  #include <common.h>
  #include <command.h>
  #include <rtc.h>
  #include <i2c.h>
  
  /*
  	I Don't have an example config file but this
  	is what should be done.
  
  #define CONFIG_RTC_M41T11 1
  #define CONFIG_SYS_I2C_RTC_ADDR 0x68
  #if 0
  #define CONFIG_SYS_M41T11_EXT_CENTURY_DATA
  #else
  #define CONFIG_SYS_M41T11_BASE_YEAR 2000
  #endif
  */
  
  #if defined(CONFIG_SYS_I2C_RTC_ADDR) && defined(CONFIG_CMD_DATE)
  
  /* ------------------------------------------------------------------------- */
  /*
    these are simple defines for the chip local to here so they aren't too
    verbose
    DAY/DATE aren't nice but that is how they are on the data sheet
  */
  #define RTC_SEC_ADDR       0x0
  #define RTC_MIN_ADDR       0x1
  #define RTC_HOUR_ADDR      0x2
  #define RTC_DAY_ADDR       0x3
  #define RTC_DATE_ADDR      0x4
  #define RTC_MONTH_ADDR     0x5
  #define RTC_YEARS_ADDR     0x6
  
  #define RTC_REG_CNT        7
  
  #define RTC_CONTROL_ADDR   0x7
  
  
  #ifndef CONFIG_SYS_M41T11_EXT_CENTURY_DATA
  
  #define REG_CNT            (RTC_REG_CNT+1)
  
  /*
    you only get 00-99 for the year we will asume you
    want from the year 2000 if you don't set the config
  */
  #ifndef CONFIG_SYS_M41T11_BASE_YEAR
  #define CONFIG_SYS_M41T11_BASE_YEAR 2000
  #endif
  
  #else
  /* we will store extra year info in byte 9*/
  #define M41T11_YEAR_DATA   0x8
  #define M41T11_YEAR_SIZE   1
  #define REG_CNT            (RTC_REG_CNT+1+M41T11_YEAR_SIZE)
  #endif
  
  #define M41T11_STORAGE_SZ  (64-REG_CNT)
  
  int rtc_get (struct rtc_time *tmp)
  {
  	int rel = 0;
  	uchar data[RTC_REG_CNT];
  
  	i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, data, RTC_REG_CNT);
  
  	if( data[RTC_SEC_ADDR] & 0x80 ){
  		printf( "m41t11 RTC Clock stopped!!!
  " );
  		rel = -1;
  	}
  	tmp->tm_sec  = bcd2bin (data[RTC_SEC_ADDR]  & 0x7F);
  	tmp->tm_min  = bcd2bin (data[RTC_MIN_ADDR]  & 0x7F);
  	tmp->tm_hour = bcd2bin (data[RTC_HOUR_ADDR] & 0x3F);
  	tmp->tm_mday = bcd2bin (data[RTC_DATE_ADDR] & 0x3F);
  	tmp->tm_mon  = bcd2bin (data[RTC_MONTH_ADDR]& 0x1F);
  #ifndef CONFIG_SYS_M41T11_EXT_CENTURY_DATA
  	tmp->tm_year = CONFIG_SYS_M41T11_BASE_YEAR
  		+ bcd2bin(data[RTC_YEARS_ADDR])
  		+ ((data[RTC_HOUR_ADDR]&0x40) ? 100 : 0);
  #else
  	{
  		unsigned char cent;
  		i2c_read(CONFIG_SYS_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, &cent, M41T11_YEAR_SIZE);
  		if( !(data[RTC_HOUR_ADDR] & 0x80) ){
  			printf( "m41t11 RTC: cann't keep track of years without CEB set
  " );
  			rel = -1;
  		}
  		if( (cent & 0x1) != ((data[RTC_HOUR_ADDR]&0x40)>>7) ){
  			/*century flip store off new year*/
  			cent += 1;
  			i2c_write(CONFIG_SYS_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, &cent, M41T11_YEAR_SIZE);
  		}
  		tmp->tm_year =((int)cent*100)+bcd2bin(data[RTC_YEARS_ADDR]);
  	}
  #endif
  	tmp->tm_wday = bcd2bin (data[RTC_DAY_ADDR]  & 0x07);
  	tmp->tm_yday = 0;
  	tmp->tm_isdst= 0;
  
  	debug ( "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);
  
  	return rel;
  }
  
  int rtc_set (struct rtc_time *tmp)
  {
  	uchar data[RTC_REG_CNT];
  
  	debug ( "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);
  
  	data[RTC_SEC_ADDR]    = bin2bcd(tmp->tm_sec) &  0x7F;/*just in case*/
  	data[RTC_MIN_ADDR]    = bin2bcd(tmp->tm_min);
  	data[RTC_HOUR_ADDR]   = bin2bcd(tmp->tm_hour) & 0x3F;/*handle cent stuff later*/
  	data[RTC_DATE_ADDR]   = bin2bcd(tmp->tm_mday) & 0x3F;
  	data[RTC_MONTH_ADDR]  = bin2bcd(tmp->tm_mon);
  	data[RTC_DAY_ADDR]    = bin2bcd(tmp->tm_wday) & 0x07;
  
  	data[RTC_HOUR_ADDR]   |= 0x80;/*we will always use CEB*/
  
  	data[RTC_YEARS_ADDR]  = bin2bcd(tmp->tm_year%100);/*same thing either way*/
  #ifndef CONFIG_SYS_M41T11_EXT_CENTURY_DATA
  	if( ((tmp->tm_year - CONFIG_SYS_M41T11_BASE_YEAR) > 200) ||
  	    (tmp->tm_year < CONFIG_SYS_M41T11_BASE_YEAR) ){
  		printf( "m41t11 RTC setting year out of range!!need recompile
  " );
  	}
  	data[RTC_HOUR_ADDR] |= (tmp->tm_year - CONFIG_SYS_M41T11_BASE_YEAR) > 100 ? 0x40 : 0;
  #else
  	{
  		unsigned char cent;
  		cent = tmp->tm_year ? tmp->tm_year / 100 : 0;
  		data[RTC_HOUR_ADDR] |= (cent & 0x1) ? 0x40 : 0;
  		i2c_write(CONFIG_SYS_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, &cent, M41T11_YEAR_SIZE);
  	}
  #endif
  	i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, data, RTC_REG_CNT);
  
  	return 0;
  }
  
  void rtc_reset (void)
  {
  	unsigned char val;
  	/* clear all control & status registers */
  	i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, &val, 1);
  	val = val & 0x7F;/*make sure we are running*/
  	i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, &val, RTC_REG_CNT);
  
  	i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_CONTROL_ADDR, 1, &val, 1);
  	val = val & 0x3F;/*turn off freq test keep calibration*/
  	i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_CONTROL_ADDR, 1, &val, 1);
  }
  #endif