/*
   * (C) Copyright 2007
   * Matthias Fuchs, esd gmbh, matthias.fuchs@esd-electronics.com.
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  /*
   * Epson RX8025 RTC driver.
   */
  
  #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	0x32
  #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_CTL1_REG_ADDR	0x0e
  #define RTC_CTL2_REG_ADDR	0x0f
  
  /*
   * Control register 1 bits
   */
  #define RTC_CTL1_BIT_2412	0x20
  
  /*
   * Control register 2 bits
   */
  #define RTC_CTL2_BIT_PON	0x10
  #define RTC_CTL2_BIT_VDET	0x40
  #define RTC_CTL2_BIT_XST	0x20
  #define RTC_CTL2_BIT_VDSL	0x80
  
  /*
   * Note: the RX8025 I2C RTC requires register
   * reads and write to consist of a single bus
   * cycle. It is not allowed to write the register
   * address in a first cycle that is terminated by
   * a STOP condition. The chips needs a 'restart'
   * sequence (start sequence without a prior stop).
   * This driver has been written for a 4xx board.
   * U-Boot's 4xx i2c driver is currently not capable
   * to generate such cycles to some work arounds
   * are used.
   */
  
  /* static uchar rtc_read (uchar reg); */
  #define rtc_read(reg) buf[((reg) + 1) & 0xf]
  
  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, ctl2;
  	uchar buf[16];
  
  	if (i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, 16))
  		printf("Error reading from RTC
  ");
  
  	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);
  
  	/* dump status */
  	ctl2 = rtc_read(RTC_CTL2_REG_ADDR);
  	if (ctl2 & RTC_CTL2_BIT_PON) {
  		printf("RTC: power-on detected
  ");
  		rel = -1;
  	}
  
  	if (ctl2 & RTC_CTL2_BIT_VDET) {
  		printf("RTC: voltage drop detected
  ");
  		rel = -1;
  	}
  
  	if (!(ctl2 & RTC_CTL2_BIT_XST)) {
  		printf("RTC: oscillator stop detected
  ");
  		rel = -1;
  	}
  
  	tmp->tm_sec  = bcd2bin (sec & 0x7F);
  	tmp->tm_min  = bcd2bin (min & 0x7F);
  	if (rtc_read(RTC_CTL1_REG_ADDR) & RTC_CTL1_BIT_2412)
  		tmp->tm_hour = bcd2bin (hour & 0x3F);
  	else
  		tmp->tm_hour = bcd2bin (hour & 0x1F) % 12 +
  			       ((hour & 0x20) ? 12 : 0);
  	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 & 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));
  	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));
  
  	rtc_write (RTC_CTL1_REG_ADDR, RTC_CTL1_BIT_2412);
  
  	return 0;
  }
  
  /*
   * Reset the RTC. We setting the date back to 1970-01-01.
   */
  void rtc_reset (void)
  {
  	struct rtc_time tmp;
  	uchar buf[16];
  	uchar ctl2;
  
  	if (i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0,    0,   buf, 16))
  		printf("Error reading from RTC
  ");
  
  	ctl2 = rtc_read(RTC_CTL2_REG_ADDR);
  	ctl2 &= ~(RTC_CTL2_BIT_PON | RTC_CTL2_BIT_VDET);
  	ctl2 |= RTC_CTL2_BIT_XST | RTC_CTL2_BIT_VDSL;
  	rtc_write (RTC_CTL2_REG_ADDR, ctl2);
  
  	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 void rtc_write (uchar reg, uchar val)
  {
  	uchar buf[2];
  	buf[0] = reg << 4;
  	buf[1] = val;
  	if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, 2) != 0)
  		printf("Error writing to RTC
  ");
  
  }
  
  #endif /* CONFIG_RTC_RX8025 && CONFIG_CMD_DATE */