/*
   * (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
  ",
  		year, mon, mday, wday, hour, min, sec);
  
  	if (sec & RTC_SEC_BIT_CH) {
  		printf ("### Warning: RTC oscillator has stopped
  ");
  		/* 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
  ",
  		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
  ",
  		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!
  ");
  
  	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
  ",
  		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