/*
   * (C) Copyright 2002 SIXNET, dge@sixnetio.com.
   *

   * (C) Copyright 2004, Li-Pro.Net <www.li-pro.net>
   * Stephan Linz <linz@li-pro.net>
   *

   * SPDX-License-Identifier:	GPL-2.0+

   */
  
  /*

   * Date & Time support for DS1306 RTC using SPI:
   *
   *    - SXNI855T:    it uses its own soft SPI here in this file
   *    - all other:   use the external spi_xfer() function
   *                   (see include/spi.h)

   */
  
  #include <common.h>
  #include <command.h>
  #include <rtc.h>

  #include <spi.h>

  #if defined(CONFIG_CMD_DATE)

  #define	RTC_SECONDS		0x00
  #define	RTC_MINUTES		0x01
  #define	RTC_HOURS		0x02
  #define	RTC_DAY_OF_WEEK		0x03
  #define	RTC_DATE_OF_MONTH	0x04
  #define	RTC_MONTH		0x05
  #define	RTC_YEAR		0x06
  
  #define	RTC_SECONDS_ALARM0	0x07
  #define	RTC_MINUTES_ALARM0	0x08
  #define	RTC_HOURS_ALARM0	0x09
  #define	RTC_DAY_OF_WEEK_ALARM0	0x0a
  
  #define	RTC_SECONDS_ALARM1	0x0b
  #define	RTC_MINUTES_ALARM1	0x0c
  #define	RTC_HOURS_ALARM1	0x0d
  #define	RTC_DAY_OF_WEEK_ALARM1	0x0e
  
  #define	RTC_CONTROL		0x0f
  #define	RTC_STATUS		0x10
  #define	RTC_TRICKLE_CHARGER	0x11
  
  #define	RTC_USER_RAM_BASE	0x20

  /* ************************************************************************* */
  #ifdef CONFIG_SXNI855T		/* !!! SHOULD BE CHANGED TO NEW CODE !!! */
  
  static void soft_spi_send (unsigned char n);
  static unsigned char soft_spi_read (void);
  static void init_spi (void);

  
  /*-----------------------------------------------------------------------
   * Definitions
   */
  
  #define	PB_SPISCK	0x00000002	/* PB 30 */
  #define PB_SPIMOSI	0x00000004	/* PB 29 */
  #define PB_SPIMISO	0x00000008	/* PB 28 */
  #define PB_SPI_CE	0x00010000	/* PB 15 */
  
  /* ------------------------------------------------------------------------- */
  
  /* read clock time from DS1306 and return it in *tmp */

  int rtc_get (struct rtc_time *tmp)

  {

  	volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;

  	unsigned char spi_byte;	/* Data Byte */
  
  	init_spi ();		/* set port B for software SPI */
  
  	/* Now we can enable the DS1306 RTC */
  	immap->im_cpm.cp_pbdat |= PB_SPI_CE;
  	udelay (10);
  
  	/* Shift out the address (0) of the time in the Clock Chip */
  	soft_spi_send (0);
  
  	/* Put the clock readings into the rtc_time structure */
  	tmp->tm_sec = bcd2bin (soft_spi_read ());	/* Read seconds */
  	tmp->tm_min = bcd2bin (soft_spi_read ());	/* Read minutes */
  
  	/* Hours are trickier */
  	spi_byte = soft_spi_read ();	/* Read Hours into temporary value */
  	if (spi_byte & 0x40) {
  		/* 12 hour mode bit is set (time is in 1-12 format) */
  		if (spi_byte & 0x20) {
  			/* since PM we add 11 to get 0-23 for hours */
  			tmp->tm_hour = (bcd2bin (spi_byte & 0x1F)) + 11;
  		} else {
  			/* since AM we subtract 1 to get 0-23 for hours */
  			tmp->tm_hour = (bcd2bin (spi_byte & 0x1F)) - 1;
  		}
  	} else {
  		/* Otherwise, 0-23 hour format */
  		tmp->tm_hour = (bcd2bin (spi_byte & 0x3F));
  	}

  	soft_spi_read ();	/* Read and discard Day of week */
  	tmp->tm_mday = bcd2bin (soft_spi_read ());	/* Read Day of the Month */
  	tmp->tm_mon = bcd2bin (soft_spi_read ());	/* Read Month */

  	/* Read Year and convert to this century */
  	tmp->tm_year = bcd2bin (soft_spi_read ()) + 2000;

  	/* Now we can disable the DS1306 RTC */
  	immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;	/* Disable DS1306 Chip */
  	udelay (10);

  	GregorianDay (tmp);	/* Determine the day of week */

  	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;

  }
  
  /* ------------------------------------------------------------------------- */
  
  /* set clock time in DS1306 RTC and in MPC8xx RTC */

  int rtc_set (struct rtc_time *tmp)

  {

  	volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;

  
  	init_spi ();		/* set port B for software SPI */
  
  	/* Now we can enable the DS1306 RTC */
  	immap->im_cpm.cp_pbdat |= PB_SPI_CE;	/* Enable DS1306 Chip */
  	udelay (10);
  
  	/* First disable write protect in the clock chip control register */
  	soft_spi_send (0x8F);	/* send address of the control register */
  	soft_spi_send (0x00);	/* send control register contents */
  
  	/* Now disable the DS1306 to terminate the write */
  	immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;
  	udelay (10);
  
  	/* Now enable the DS1306 to initiate a new write */
  	immap->im_cpm.cp_pbdat |= PB_SPI_CE;
  	udelay (10);
  
  	/* Next, send the address of the clock time write registers */
  	soft_spi_send (0x80);	/* send address of the first time register */
  
  	/* Use Burst Mode to send all of the time data to the clock */
  	bin2bcd (tmp->tm_sec);
  	soft_spi_send (bin2bcd (tmp->tm_sec));	/* Send Seconds */
  	soft_spi_send (bin2bcd (tmp->tm_min));	/* Send Minutes */
  	soft_spi_send (bin2bcd (tmp->tm_hour));	/* Send Hour */
  	soft_spi_send (bin2bcd (tmp->tm_wday));	/* Send Day of the Week */
  	soft_spi_send (bin2bcd (tmp->tm_mday));	/* Send Day of Month */
  	soft_spi_send (bin2bcd (tmp->tm_mon));	/* Send Month */
  	soft_spi_send (bin2bcd (tmp->tm_year - 2000));	/* Send Year */
  
  	/* Now we can disable the Clock chip to terminate the burst write */
  	immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;	/* Disable DS1306 Chip */
  	udelay (10);
  
  	/* Now we can enable the Clock chip to initiate a new write */
  	immap->im_cpm.cp_pbdat |= PB_SPI_CE;	/* Enable DS1306 Chip */
  	udelay (10);
  
  	/* First we Enable write protect in the clock chip control register */
  	soft_spi_send (0x8F);	/* send address of the control register */
  	soft_spi_send (0x40);	/* send out Control Register contents */
  
  	/* Now disable the DS1306 */
  	immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;	/*  Disable DS1306 Chip */
  	udelay (10);
  
  	/* Set standard MPC8xx clock to the same time so Linux will
  	 * see the time even if it doesn't have a DS1306 clock driver.
  	 * This helps with experimenting with standard kernels.
  	 */
  	{
  		ulong tim;
  
  		tim = mktime (tmp->tm_year, tmp->tm_mon, tmp->tm_mday,
  			      tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  
  		immap->im_sitk.sitk_rtck = KAPWR_KEY;
  		immap->im_sit.sit_rtc = tim;

  	}

  	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);

  
  	return 0;

  }

  /* ------------------------------------------------------------------------- */

  /* Initialize Port B for software SPI */
  static void init_spi (void)
  {

  	volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;

  	/* Force output pins to begin at logic 0 */
  	immap->im_cpm.cp_pbdat &= ~(PB_SPI_CE | PB_SPIMOSI | PB_SPISCK);

  	/* Set these 3 signals as outputs */
  	immap->im_cpm.cp_pbdir |= (PB_SPIMOSI | PB_SPI_CE | PB_SPISCK);
  
  	immap->im_cpm.cp_pbdir &= ~PB_SPIMISO;	/* Make MISO pin an input */
  	udelay (10);

  }
  
  /* ------------------------------------------------------------------------- */

  /* NOTE: soft_spi_send() assumes that the I/O lines are configured already */
  static void soft_spi_send (unsigned char n)

  {

  	volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;

  	unsigned char bitpos;	/* bit position to receive */
  	unsigned char i;	/* Loop Control */
  
  	/* bit position to send, start with most significant bit */
  	bitpos = 0x80;
  
  	/* Send 8 bits to software SPI */
  	for (i = 0; i < 8; i++) {	/* Loop for 8 bits */
  		immap->im_cpm.cp_pbdat |= PB_SPISCK;	/* Raise SCK */
  
  		if (n & bitpos)
  			immap->im_cpm.cp_pbdat |= PB_SPIMOSI;	/* Set MOSI to 1 */
  		else
  			immap->im_cpm.cp_pbdat &= ~PB_SPIMOSI;	/* Set MOSI to 0 */
  		udelay (10);
  
  		immap->im_cpm.cp_pbdat &= ~PB_SPISCK;	/* Lower SCK */
  		udelay (10);
  
  		bitpos >>= 1;	/* Shift for next bit position */
  	}

  }
  
  /* ------------------------------------------------------------------------- */

  /* NOTE: soft_spi_read() assumes that the I/O lines are configured already */
  static unsigned char soft_spi_read (void)

  {

  	volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;

  
  	unsigned char spi_byte = 0;	/* Return value, assume success */
  	unsigned char bitpos;	/* bit position to receive */
  	unsigned char i;	/* Loop Control */
  
  	/* bit position to receive, start with most significant bit */
  	bitpos = 0x80;
  
  	/* Read 8 bits here */
  	for (i = 0; i < 8; i++) {	/* Do 8 bits in loop */
  		immap->im_cpm.cp_pbdat |= PB_SPISCK;	/* Raise SCK */
  		udelay (10);
  		if (immap->im_cpm.cp_pbdat & PB_SPIMISO)	/* Get a bit of data */
  			spi_byte |= bitpos;	/* Set data accordingly */
  		immap->im_cpm.cp_pbdat &= ~PB_SPISCK;	/* Lower SCK */
  		udelay (10);
  		bitpos >>= 1;	/* Shift for next bit position */
  	}
  
  	return spi_byte;	/* Return the byte read */

  }
  
  /* ------------------------------------------------------------------------- */

  void rtc_reset (void)

  {

  	return;			/* nothing to do */
  }
  
  #else  /* not CONFIG_SXNI855T */
  /* ************************************************************************* */

  static unsigned char rtc_read (unsigned char reg);
  static void rtc_write (unsigned char reg, unsigned char val);

  static struct spi_slave *slave;

  /* read clock time from DS1306 and return it in *tmp */

  int rtc_get (struct rtc_time *tmp)

  {
  	unsigned char sec, min, hour, mday, wday, mon, year;

  	/*
  	 * Assuming Vcc = 2.0V (lowest speed)
  	 *
  	 * REVISIT: If we add an rtc_init() function we can do this
  	 * step just once.
  	 */
  	if (!slave) {

  		slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,

  				SPI_MODE_3 | SPI_CS_HIGH);
  		if (!slave)
  			return;
  	}
  
  	if (spi_claim_bus(slave))
  		return;

  	sec = rtc_read (RTC_SECONDS);
  	min = rtc_read (RTC_MINUTES);
  	hour = rtc_read (RTC_HOURS);
  	mday = rtc_read (RTC_DATE_OF_MONTH);
  	wday = rtc_read (RTC_DAY_OF_WEEK);
  	mon = rtc_read (RTC_MONTH);
  	year = rtc_read (RTC_YEAR);

  	spi_release_bus(slave);

  	debug ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
  	       "hr: %02x min: %02x sec: %02x
  ",
  	       year, mon, mday, wday, hour, min, sec);
  	debug ("Alarms[0]: wday: %02x hour: %02x min: %02x sec: %02x
  ",
  	       rtc_read (RTC_DAY_OF_WEEK_ALARM0),
  	       rtc_read (RTC_HOURS_ALARM0),
  	       rtc_read (RTC_MINUTES_ALARM0), rtc_read (RTC_SECONDS_ALARM0));
  	debug ("Alarms[1]: wday: %02x hour: %02x min: %02x sec: %02x
  ",
  	       rtc_read (RTC_DAY_OF_WEEK_ALARM1),
  	       rtc_read (RTC_HOURS_ALARM1),
  	       rtc_read (RTC_MINUTES_ALARM1), rtc_read (RTC_SECONDS_ALARM1));
  
  	tmp->tm_sec = bcd2bin (sec & 0x7F);	/* convert Seconds */
  	tmp->tm_min = bcd2bin (min & 0x7F);	/* convert Minutes */
  
  	/* convert Hours */
  	tmp->tm_hour = (hour & 0x40)
  		? ((hour & 0x20)	/* 12 hour mode */
  		   ? bcd2bin (hour & 0x1F) + 11	/* PM */
  		   : bcd2bin (hour & 0x1F) - 1	/* AM */
  		)
  		: bcd2bin (hour & 0x3F);	/* 24 hour mode */
  
  	tmp->tm_mday = bcd2bin (mday & 0x3F);	/* convert Day of the Month */
  	tmp->tm_mon = bcd2bin (mon & 0x1F);	/* convert Month */
  	tmp->tm_year = bcd2bin (year) + 2000;	/* convert Year */
  	tmp->tm_wday = bcd2bin (wday & 0x07) - 1;	/* convert Day of the Week */
  	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;

  }
  
  /* ------------------------------------------------------------------------- */

  /* set clock time from *tmp in DS1306 RTC */

  int rtc_set (struct rtc_time *tmp)

  {

  	/* Assuming Vcc = 2.0V (lowest speed) */
  	if (!slave) {

  		slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,

  				SPI_MODE_3 | SPI_CS_HIGH);
  		if (!slave)
  			return;
  	}
  
  	if (spi_claim_bus(slave))
  		return;

  	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);

  	rtc_write (RTC_SECONDS, bin2bcd (tmp->tm_sec));

  	rtc_write (RTC_MINUTES, bin2bcd (tmp->tm_min));
  	rtc_write (RTC_HOURS, bin2bcd (tmp->tm_hour));
  	rtc_write (RTC_DAY_OF_WEEK, bin2bcd (tmp->tm_wday + 1));
  	rtc_write (RTC_DATE_OF_MONTH, bin2bcd (tmp->tm_mday));
  	rtc_write (RTC_MONTH, bin2bcd (tmp->tm_mon));
  	rtc_write (RTC_YEAR, bin2bcd (tmp->tm_year - 2000));

  
  	spi_release_bus(slave);

  }
  
  /* ------------------------------------------------------------------------- */

  /* reset the DS1306 */
  void rtc_reset (void)
  {

  	/* Assuming Vcc = 2.0V (lowest speed) */
  	if (!slave) {

  		slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,

  				SPI_MODE_3 | SPI_CS_HIGH);
  		if (!slave)
  			return;
  	}
  
  	if (spi_claim_bus(slave))
  		return;

  	/* clear the control register */
  	rtc_write (RTC_CONTROL, 0x00);	/* 1st step: reset WP */
  	rtc_write (RTC_CONTROL, 0x00);	/* 2nd step: reset 1Hz, AIE1, AIE0 */
  
  	/* reset all alarms */
  	rtc_write (RTC_SECONDS_ALARM0, 0x00);
  	rtc_write (RTC_SECONDS_ALARM1, 0x00);
  	rtc_write (RTC_MINUTES_ALARM0, 0x00);
  	rtc_write (RTC_MINUTES_ALARM1, 0x00);
  	rtc_write (RTC_HOURS_ALARM0, 0x00);
  	rtc_write (RTC_HOURS_ALARM1, 0x00);
  	rtc_write (RTC_DAY_OF_WEEK_ALARM0, 0x00);
  	rtc_write (RTC_DAY_OF_WEEK_ALARM1, 0x00);

  
  	spi_release_bus(slave);

  }
  
  /* ------------------------------------------------------------------------- */

  static unsigned char rtc_read (unsigned char reg)
  {

  	int ret;

  	ret = spi_w8r8(slave, reg);
  	return ret < 0 ? 0 : ret;

  }
  
  /* ------------------------------------------------------------------------- */

  static void rtc_write (unsigned char reg, unsigned char val)

  {

  	unsigned char dout[2];	/* SPI Output Data Bytes */
  	unsigned char din[2];	/* SPI Input Data Bytes */

  	dout[0] = 0x80 | reg;
  	dout[1] = val;

  	spi_xfer (slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END);

  }

  #endif /* end of code exclusion (see #ifdef CONFIG_SXNI855T above) */

  #endif