/*
   * (C) Copyright 2010
   * Heiko Schocher, DENX Software Engineering, hs@denx.de
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  #include <common.h>
  #include <command.h>
  #include <i2c.h>
  #include <rtc.h>
  
  #define RTC_RV3029_CTRL1	0x00
  #define RTC_RV3029_CTRL1_EERE	(1 << 3)
  
  #define RTC_RV3029_CTRL_STATUS	0x03
  #define RTC_RV3029_CTRLS_EEBUSY	(1 << 7)
  
  #define RTC_RV3029_CTRL_RESET	0x04
  #define RTC_RV3029_CTRL_SYS_R	(1 << 4)
  
  #define RTC_RV3029_CLOCK_PAGE	0x08
  #define RTC_RV3029_PAGE_LEN	7
  
  #define RV3029C2_W_SECONDS	0x00
  #define RV3029C2_W_MINUTES	0x01
  #define RV3029C2_W_HOURS	0x02
  #define RV3029C2_W_DATE		0x03
  #define RV3029C2_W_DAYS		0x04
  #define RV3029C2_W_MONTHS	0x05
  #define RV3029C2_W_YEARS	0x06
  
  #define RV3029C2_REG_HR_12_24          (1 << 6)  /* 24h/12h mode */
  #define RV3029C2_REG_HR_PM             (1 << 5)  /* PM/AM bit in 12h mode */
  
  #define RTC_RV3029_EEPROM_CTRL	0x30
  #define RTC_RV3029_TRICKLE_1K	(1 << 4)
  #define RTC_RV3029_TRICKLE_5K	(1 << 5)
  #define RTC_RV3029_TRICKLE_20K	(1 << 6)
  #define RTC_RV3029_TRICKLE_80K	(1 << 7)
  
  int rtc_get( struct rtc_time *tmp )
  {
  	int	ret;
  	unsigned char buf[RTC_RV3029_PAGE_LEN];
  
  	ret = i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CLOCK_PAGE, 1, buf, \
  			RTC_RV3029_PAGE_LEN);
  	if (ret) {
  		printf("%s: error reading RTC: %x
  ", __func__, ret);
  		return -1;
  	}
  	tmp->tm_sec  = bcd2bin( buf[RV3029C2_W_SECONDS] & 0x7f);
  	tmp->tm_min  = bcd2bin( buf[RV3029C2_W_MINUTES] & 0x7f);
  	if (buf[RV3029C2_W_HOURS] & RV3029C2_REG_HR_12_24) {
  		/* 12h format */
  		tmp->tm_hour = bcd2bin(buf[RV3029C2_W_HOURS] & 0x1f);
  		if (buf[RV3029C2_W_HOURS] & RV3029C2_REG_HR_PM)
  			/* PM flag set */
  			tmp->tm_hour += 12;
  	} else
  		tmp->tm_hour = bcd2bin(buf[RV3029C2_W_HOURS] & 0x3f);
  
  	tmp->tm_mday = bcd2bin( buf[RV3029C2_W_DATE] & 0x3F );
  	tmp->tm_mon  = bcd2bin( buf[RV3029C2_W_MONTHS] & 0x1F );
  	tmp->tm_wday = bcd2bin( buf[RV3029C2_W_DAYS] & 0x07 );
  	/* RTC supports only years > 1999 */
  	tmp->tm_year = bcd2bin( buf[RV3029C2_W_YEARS]) + 2000;
  	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 0;
  }
  
  int rtc_set( struct rtc_time *tmp )
  {
  	int	ret;
  	unsigned char buf[RTC_RV3029_PAGE_LEN];
  
  	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);
  
  	if (tmp->tm_year < 2000) {
  		printf("RTC: year %d < 2000 not possible
  ", tmp->tm_year);
  		return -1;
  	}
  	buf[RV3029C2_W_SECONDS] = bin2bcd(tmp->tm_sec);
  	buf[RV3029C2_W_MINUTES] = bin2bcd(tmp->tm_min);
  	buf[RV3029C2_W_HOURS] = bin2bcd(tmp->tm_hour);
  	/* set 24h format */
  	buf[RV3029C2_W_HOURS] &= ~RV3029C2_REG_HR_12_24;
  	buf[RV3029C2_W_DATE] = bin2bcd(tmp->tm_mday);
  	buf[RV3029C2_W_DAYS] = bin2bcd(tmp->tm_wday);
  	buf[RV3029C2_W_MONTHS] = bin2bcd(tmp->tm_mon);
  	tmp->tm_year -= 2000;
  	buf[RV3029C2_W_YEARS] = bin2bcd(tmp->tm_year);
  	ret = i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CLOCK_PAGE, 1,
  			buf, RTC_RV3029_PAGE_LEN);
  
  	/* give the RTC some time to update */
  	udelay(1000);
  	return ret;
  }
  
  /* sets EERE-Bit  (automatic EEPROM refresh) */
  static void set_eere_bit(int state)
  {
  	unsigned char reg_ctrl1;
  
  	(void)i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL1, 1,
  			&reg_ctrl1, 1);
  
  	if (state)
  		reg_ctrl1 |= RTC_RV3029_CTRL1_EERE;
  	else
  		reg_ctrl1 &= (~RTC_RV3029_CTRL1_EERE);
  
  	(void)i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL1, 1,
  		&reg_ctrl1, 1);
  }
  
  /* waits until EEPROM page is no longer busy (times out after 10ms*loops) */
  static int wait_eebusy(int loops)
  {
  	int i;
  	unsigned char ctrl_status;
  
  	for (i = 0; i < loops; i++) {
  		(void)i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL_STATUS,
  			1, &ctrl_status, 1);
  
  		if ((ctrl_status & RTC_RV3029_CTRLS_EEBUSY) == 0)
  			break;
  		udelay(10000);
  	}
  	return i;
  }
  
  void rtc_reset (void)
  {
  	unsigned char buf[RTC_RV3029_PAGE_LEN];
  
  	buf[0] = RTC_RV3029_CTRL_SYS_R;
  	(void)i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL_RESET, 1,
  			buf, 1);
  
  #if defined(CONFIG_SYS_RV3029_TCR)
  	/*
  	 * because EEPROM_CTRL register is in EEPROM page it is necessary to
  	 * disable automatic EEPROM refresh and check if EEPROM is busy
  	 * before EEPORM_CTRL register may be accessed
  	 */
  	set_eere_bit(0);
  	wait_eebusy(100);
  	/* read current trickle charger setting */
  	(void)i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_EEPROM_CTRL,
  			1, buf, 1);
  	/* enable automatic EEPROM refresh again */
  	set_eere_bit(1);
  
  	/*
  	 * to minimize EEPROM access write trickle charger setting only if it
  	 * differs from current value
  	 */
  	if ((buf[0] & 0xF0) != CONFIG_SYS_RV3029_TCR) {
  		buf[0] = (buf[0] & 0x0F) | CONFIG_SYS_RV3029_TCR;
  		/*
  		 * write trickle charger setting (disable autom. EEPROM
  		 * refresh and wait until EEPROM is idle)
  		 */
  		set_eere_bit(0);
  		wait_eebusy(100);
  		(void)i2c_write(CONFIG_SYS_I2C_RTC_ADDR,
  				RTC_RV3029_EEPROM_CTRL, 1, buf, 1);
  		/*
  		 * it is necessary to wait 10ms before EEBUSY-Bit may be read
  		 * (this is not documented in the data sheet yet, but the
  		 * manufacturer recommends it)
  		 */
  		udelay(10000);
  		/* wait until EEPROM write access is finished */
  		wait_eebusy(100);
  		set_eere_bit(1);
  	}
  #endif
  }