/*
   * File:         drivers/ata/pata_bf54x.c
   * Author:       Sonic Zhang <sonic.zhang@analog.com>
   *
   * Created:
   * Description:  PATA Driver for blackfin 54x
   *
   * Modified:
   *               Copyright 2007 Analog Devices Inc.
   *
   * Bugs:         Enter bugs at http://blackfin.uclinux.org/
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, see the file COPYING, or write
   * to the Free Software Foundation, Inc.,
   * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/pci.h>
  #include <linux/init.h>
  #include <linux/blkdev.h>
  #include <linux/delay.h>
  #include <linux/device.h>
  #include <scsi/scsi_host.h>
  #include <linux/libata.h>
  #include <linux/platform_device.h>
  #include <asm/dma.h>
  #include <asm/gpio.h>
  #include <asm/portmux.h>
  
  #define DRV_NAME		"pata-bf54x"
  #define DRV_VERSION		"0.9"
  
  #define ATA_REG_CTRL		0x0E
  #define ATA_REG_ALTSTATUS	ATA_REG_CTRL
  
  /* These are the offset of the controller's registers */
  #define ATAPI_OFFSET_CONTROL		0x00
  #define ATAPI_OFFSET_STATUS		0x04
  #define ATAPI_OFFSET_DEV_ADDR		0x08
  #define ATAPI_OFFSET_DEV_TXBUF		0x0c
  #define ATAPI_OFFSET_DEV_RXBUF		0x10
  #define ATAPI_OFFSET_INT_MASK		0x14
  #define ATAPI_OFFSET_INT_STATUS		0x18
  #define ATAPI_OFFSET_XFER_LEN		0x1c
  #define ATAPI_OFFSET_LINE_STATUS	0x20
  #define ATAPI_OFFSET_SM_STATE		0x24
  #define ATAPI_OFFSET_TERMINATE		0x28
  #define ATAPI_OFFSET_PIO_TFRCNT		0x2c
  #define ATAPI_OFFSET_DMA_TFRCNT		0x30
  #define ATAPI_OFFSET_UMAIN_TFRCNT	0x34
  #define ATAPI_OFFSET_UDMAOUT_TFRCNT	0x38
  #define ATAPI_OFFSET_REG_TIM_0		0x40
  #define ATAPI_OFFSET_PIO_TIM_0		0x44
  #define ATAPI_OFFSET_PIO_TIM_1		0x48
  #define ATAPI_OFFSET_MULTI_TIM_0	0x50
  #define ATAPI_OFFSET_MULTI_TIM_1	0x54
  #define ATAPI_OFFSET_MULTI_TIM_2	0x58
  #define ATAPI_OFFSET_ULTRA_TIM_0	0x60
  #define ATAPI_OFFSET_ULTRA_TIM_1	0x64
  #define ATAPI_OFFSET_ULTRA_TIM_2	0x68
  #define ATAPI_OFFSET_ULTRA_TIM_3	0x6c
  
  
  #define ATAPI_GET_CONTROL(base)\
  	bfin_read16(base + ATAPI_OFFSET_CONTROL)
  #define ATAPI_SET_CONTROL(base, val)\
  	bfin_write16(base + ATAPI_OFFSET_CONTROL, val)
  #define ATAPI_GET_STATUS(base)\
  	bfin_read16(base + ATAPI_OFFSET_STATUS)
  #define ATAPI_GET_DEV_ADDR(base)\
  	bfin_read16(base + ATAPI_OFFSET_DEV_ADDR)
  #define ATAPI_SET_DEV_ADDR(base, val)\
  	bfin_write16(base + ATAPI_OFFSET_DEV_ADDR, val)
  #define ATAPI_GET_DEV_TXBUF(base)\
  	bfin_read16(base + ATAPI_OFFSET_DEV_TXBUF)
  #define ATAPI_SET_DEV_TXBUF(base, val)\
  	bfin_write16(base + ATAPI_OFFSET_DEV_TXBUF, val)
  #define ATAPI_GET_DEV_RXBUF(base)\
  	bfin_read16(base + ATAPI_OFFSET_DEV_RXBUF)
  #define ATAPI_SET_DEV_RXBUF(base, val)\
  	bfin_write16(base + ATAPI_OFFSET_DEV_RXBUF, val)
  #define ATAPI_GET_INT_MASK(base)\
  	bfin_read16(base + ATAPI_OFFSET_INT_MASK)
  #define ATAPI_SET_INT_MASK(base, val)\
  	bfin_write16(base + ATAPI_OFFSET_INT_MASK, val)
  #define ATAPI_GET_INT_STATUS(base)\
  	bfin_read16(base + ATAPI_OFFSET_INT_STATUS)
  #define ATAPI_SET_INT_STATUS(base, val)\
  	bfin_write16(base + ATAPI_OFFSET_INT_STATUS, val)
  #define ATAPI_GET_XFER_LEN(base)\
  	bfin_read16(base + ATAPI_OFFSET_XFER_LEN)
  #define ATAPI_SET_XFER_LEN(base, val)\
  	bfin_write16(base + ATAPI_OFFSET_XFER_LEN, val)
  #define ATAPI_GET_LINE_STATUS(base)\
  	bfin_read16(base + ATAPI_OFFSET_LINE_STATUS)
  #define ATAPI_GET_SM_STATE(base)\
  	bfin_read16(base + ATAPI_OFFSET_SM_STATE)
  #define ATAPI_GET_TERMINATE(base)\
  	bfin_read16(base + ATAPI_OFFSET_TERMINATE)
  #define ATAPI_SET_TERMINATE(base, val)\
  	bfin_write16(base + ATAPI_OFFSET_TERMINATE, val)
  #define ATAPI_GET_PIO_TFRCNT(base)\
  	bfin_read16(base + ATAPI_OFFSET_PIO_TFRCNT)
  #define ATAPI_GET_DMA_TFRCNT(base)\
  	bfin_read16(base + ATAPI_OFFSET_DMA_TFRCNT)
  #define ATAPI_GET_UMAIN_TFRCNT(base)\
  	bfin_read16(base + ATAPI_OFFSET_UMAIN_TFRCNT)
  #define ATAPI_GET_UDMAOUT_TFRCNT(base)\
  	bfin_read16(base + ATAPI_OFFSET_UDMAOUT_TFRCNT)
  #define ATAPI_GET_REG_TIM_0(base)\
  	bfin_read16(base + ATAPI_OFFSET_REG_TIM_0)
  #define ATAPI_SET_REG_TIM_0(base, val)\
  	bfin_write16(base + ATAPI_OFFSET_REG_TIM_0, val)
  #define ATAPI_GET_PIO_TIM_0(base)\
  	bfin_read16(base + ATAPI_OFFSET_PIO_TIM_0)
  #define ATAPI_SET_PIO_TIM_0(base, val)\
  	bfin_write16(base + ATAPI_OFFSET_PIO_TIM_0, val)
  #define ATAPI_GET_PIO_TIM_1(base)\
  	bfin_read16(base + ATAPI_OFFSET_PIO_TIM_1)
  #define ATAPI_SET_PIO_TIM_1(base, val)\
  	bfin_write16(base + ATAPI_OFFSET_PIO_TIM_1, val)
  #define ATAPI_GET_MULTI_TIM_0(base)\
  	bfin_read16(base + ATAPI_OFFSET_MULTI_TIM_0)
  #define ATAPI_SET_MULTI_TIM_0(base, val)\
  	bfin_write16(base + ATAPI_OFFSET_MULTI_TIM_0, val)
  #define ATAPI_GET_MULTI_TIM_1(base)\
  	bfin_read16(base + ATAPI_OFFSET_MULTI_TIM_1)
  #define ATAPI_SET_MULTI_TIM_1(base, val)\
  	bfin_write16(base + ATAPI_OFFSET_MULTI_TIM_1, val)
  #define ATAPI_GET_MULTI_TIM_2(base)\
  	bfin_read16(base + ATAPI_OFFSET_MULTI_TIM_2)
  #define ATAPI_SET_MULTI_TIM_2(base, val)\
  	bfin_write16(base + ATAPI_OFFSET_MULTI_TIM_2, val)
  #define ATAPI_GET_ULTRA_TIM_0(base)\
  	bfin_read16(base + ATAPI_OFFSET_ULTRA_TIM_0)
  #define ATAPI_SET_ULTRA_TIM_0(base, val)\
  	bfin_write16(base + ATAPI_OFFSET_ULTRA_TIM_0, val)
  #define ATAPI_GET_ULTRA_TIM_1(base)\
  	bfin_read16(base + ATAPI_OFFSET_ULTRA_TIM_1)
  #define ATAPI_SET_ULTRA_TIM_1(base, val)\
  	bfin_write16(base + ATAPI_OFFSET_ULTRA_TIM_1, val)
  #define ATAPI_GET_ULTRA_TIM_2(base)\
  	bfin_read16(base + ATAPI_OFFSET_ULTRA_TIM_2)
  #define ATAPI_SET_ULTRA_TIM_2(base, val)\
  	bfin_write16(base + ATAPI_OFFSET_ULTRA_TIM_2, val)
  #define ATAPI_GET_ULTRA_TIM_3(base)\
  	bfin_read16(base + ATAPI_OFFSET_ULTRA_TIM_3)
  #define ATAPI_SET_ULTRA_TIM_3(base, val)\
  	bfin_write16(base + ATAPI_OFFSET_ULTRA_TIM_3, val)
  
  /**
   * PIO Mode - Frequency compatibility
   */
  /* mode: 0         1         2         3         4 */
  static const u32 pio_fsclk[] =
  { 33333333, 33333333, 33333333, 33333333, 33333333 };
  
  /**
   * MDMA Mode - Frequency compatibility
   */
  /*               mode:      0         1         2        */
  static const u32 mdma_fsclk[] = { 33333333, 33333333, 33333333 };
  
  /**
   * UDMA Mode - Frequency compatibility
   *
   * UDMA5 - 100 MB/s   - SCLK  = 133 MHz
   * UDMA4 - 66 MB/s    - SCLK >=  80 MHz
   * UDMA3 - 44.4 MB/s  - SCLK >=  50 MHz
   * UDMA2 - 33 MB/s    - SCLK >=  40 MHz
   */
  /* mode: 0         1         2         3         4          5 */
  static const u32 udma_fsclk[] =
  { 33333333, 33333333, 40000000, 50000000, 80000000, 133333333 };
  
  /**
   * Register transfer timing table
   */
  /*               mode:       0    1    2    3    4    */
  /* Cycle Time                     */
  static const u32 reg_t0min[]   = { 600, 383, 330, 180, 120 };
  /* DIOR/DIOW to end cycle         */
  static const u32 reg_t2min[]   = { 290, 290, 290, 70,  25  };
  /* DIOR/DIOW asserted pulse width */
  static const u32 reg_teocmin[] = { 290, 290, 290, 80,  70  };
  
  /**
   * PIO timing table
   */
  /*               mode:       0    1    2    3    4    */
  /* Cycle Time                     */
  static const u32 pio_t0min[]   = { 600, 383, 240, 180, 120 };
  /* Address valid to DIOR/DIORW    */
  static const u32 pio_t1min[]   = { 70,  50,  30,  30,  25  };
  /* DIOR/DIOW to end cycle         */
  static const u32 pio_t2min[]   = { 165, 125, 100, 80,  70  };
  /* DIOR/DIOW asserted pulse width */
  static const u32 pio_teocmin[] = { 165, 125, 100, 70,  25  };
  /* DIOW data hold                 */
  static const u32 pio_t4min[]   = { 30,  20,  15,  10,  10  };
  
  /* ******************************************************************
   * Multiword DMA timing table
   * ******************************************************************
   */
  /*               mode:       0   1    2        */
  /* Cycle Time                     */
  static const u32 mdma_t0min[]  = { 480, 150, 120 };
  /* DIOR/DIOW asserted pulse width */
  static const u32 mdma_tdmin[]  = { 215, 80,  70  };
  /* DMACK to read data released    */
  static const u32 mdma_thmin[]  = { 20,  15,  10  };
  /* DIOR/DIOW to DMACK hold        */
  static const u32 mdma_tjmin[]  = { 20,  5,   5   };
  /* DIOR negated pulse width       */
  static const u32 mdma_tkrmin[] = { 50,  50,  25  };
  /* DIOR negated pulse width       */
  static const u32 mdma_tkwmin[] = { 215, 50,  25  };
  /* CS[1:0] valid to DIOR/DIOW     */
  static const u32 mdma_tmmin[]  = { 50,  30,  25  };
  /* DMACK to read data released    */
  static const u32 mdma_tzmax[]  = { 20,  25,  25  };
  
  /**
   * Ultra DMA timing table
   */
  /*               mode:         0    1    2    3    4    5       */
  static const u32 udma_tcycmin[]  = { 112, 73,  54,  39,  25,  17 };
  static const u32 udma_tdvsmin[]  = { 70,  48,  31,  20,  7,   5  };
  static const u32 udma_tenvmax[]  = { 70,  70,  70,  55,  55,  50 };
  static const u32 udma_trpmin[]   = { 160, 125, 100, 100, 100, 85 };
  static const u32 udma_tmin[]     = { 5,   5,   5,   5,   3,   3  };
  
  
  static const u32 udma_tmlimin = 20;
  static const u32 udma_tzahmin = 20;
  static const u32 udma_tenvmin = 20;
  static const u32 udma_tackmin = 20;
  static const u32 udma_tssmin = 50;
  
  /**
   *
   *	Function:       num_clocks_min
   *
   *	Description:
   *	calculate number of SCLK cycles to meet minimum timing
   */
  static unsigned short num_clocks_min(unsigned long tmin,
  				unsigned long fsclk)
  {
  	unsigned long tmp ;
  	unsigned short result;
  
  	tmp = tmin * (fsclk/1000/1000) / 1000;
  	result = (unsigned short)tmp;
  	if ((tmp*1000*1000) < (tmin*(fsclk/1000))) {
  		result++;
  	}
  
  	return result;
  }
  
  /**
   *	bfin_set_piomode - Initialize host controller PATA PIO timings
   *	@ap: Port whose timings we are configuring
   *	@adev: um
   *
   *	Set PIO mode for device.
   *
   *	LOCKING:
   *	None (inherited from caller).
   */
  
  static void bfin_set_piomode(struct ata_port *ap, struct ata_device *adev)
  {
  	int mode = adev->pio_mode - XFER_PIO_0;
  	void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
  	unsigned int fsclk = get_sclk();
  	unsigned short teoc_reg, t2_reg, teoc_pio;
  	unsigned short t4_reg, t2_pio, t1_reg;
  	unsigned short n0, n6, t6min = 5;
  
  	/* the most restrictive timing value is t6 and tc, the DIOW - data hold
  	* If one SCLK pulse is longer than this minimum value then register
  	* transfers cannot be supported at this frequency.
  	*/
  	n6 = num_clocks_min(t6min, fsclk);
  	if (mode >= 0 && mode <= 4 && n6 >= 1) {

  		dev_dbg(adev->link->ap->dev, "set piomode: mode=%d, fsclk=%ud
  ", mode, fsclk);

  		/* calculate the timing values for register transfers. */
  		while (mode > 0 && pio_fsclk[mode] > fsclk)
  			mode--;
  
  		/* DIOR/DIOW to end cycle time */
  		t2_reg = num_clocks_min(reg_t2min[mode], fsclk);
  		/* DIOR/DIOW asserted pulse width */
  		teoc_reg = num_clocks_min(reg_teocmin[mode], fsclk);
  		/* Cycle Time */
  		n0  = num_clocks_min(reg_t0min[mode], fsclk);
  
  		/* increase t2 until we meed the minimum cycle length */
  		if (t2_reg + teoc_reg < n0)
  			t2_reg = n0 - teoc_reg;
  
  		/* calculate the timing values for pio transfers. */
  
  		/* DIOR/DIOW to end cycle time */
  		t2_pio = num_clocks_min(pio_t2min[mode], fsclk);
  		/* DIOR/DIOW asserted pulse width */
  		teoc_pio = num_clocks_min(pio_teocmin[mode], fsclk);
  		/* Cycle Time */
  		n0  = num_clocks_min(pio_t0min[mode], fsclk);
  
  		/* increase t2 until we meed the minimum cycle length */
  		if (t2_pio + teoc_pio < n0)
  			t2_pio = n0 - teoc_pio;
  
  		/* Address valid to DIOR/DIORW */
  		t1_reg = num_clocks_min(pio_t1min[mode], fsclk);
  
  		/* DIOW data hold */
  		t4_reg = num_clocks_min(pio_t4min[mode], fsclk);
  
  		ATAPI_SET_REG_TIM_0(base, (teoc_reg<<8 | t2_reg));
  		ATAPI_SET_PIO_TIM_0(base, (t4_reg<<12 | t2_pio<<4 | t1_reg));
  		ATAPI_SET_PIO_TIM_1(base, teoc_pio);
  		if (mode > 2) {
  			ATAPI_SET_CONTROL(base,
  				ATAPI_GET_CONTROL(base) | IORDY_EN);
  		} else {
  			ATAPI_SET_CONTROL(base,
  				ATAPI_GET_CONTROL(base) & ~IORDY_EN);
  		}
  
  		/* Disable host ATAPI PIO interrupts */
  		ATAPI_SET_INT_MASK(base, ATAPI_GET_INT_MASK(base)
  			& ~(PIO_DONE_MASK | HOST_TERM_XFER_MASK));
  		SSYNC();
  	}
  }
  
  /**
   *	bfin_set_dmamode - Initialize host controller PATA DMA timings
   *	@ap: Port whose timings we are configuring
   *	@adev: um

   *
   *	Set UDMA mode for device.
   *
   *	LOCKING:
   *	None (inherited from caller).
   */
  
  static void bfin_set_dmamode(struct ata_port *ap, struct ata_device *adev)
  {
  	int mode;
  	void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
  	unsigned long fsclk = get_sclk();
  	unsigned short tenv, tack, tcyc_tdvs, tdvs, tmli, tss, trp, tzah;
  	unsigned short tm, td, tkr, tkw, teoc, th;
  	unsigned short n0, nf, tfmin = 5;
  	unsigned short nmin, tcyc;
  
  	mode = adev->dma_mode - XFER_UDMA_0;
  	if (mode >= 0 && mode <= 5) {

  		dev_dbg(adev->link->ap->dev, "set udmamode: mode=%d
  ", mode);

  		/* the most restrictive timing value is t6 and tc,
  		 * the DIOW - data hold. If one SCLK pulse is longer
  		 * than this minimum value then register
  		 * transfers cannot be supported at this frequency.
  		 */
  		while (mode > 0 && udma_fsclk[mode] > fsclk)
  			mode--;
  
  		nmin = num_clocks_min(udma_tmin[mode], fsclk);
  		if (nmin >= 1) {
  			/* calculate the timing values for Ultra DMA. */
  			tdvs = num_clocks_min(udma_tdvsmin[mode], fsclk);
  			tcyc = num_clocks_min(udma_tcycmin[mode], fsclk);
  			tcyc_tdvs = 2;
  
  			/* increase tcyc - tdvs (tcyc_tdvs) until we meed
  			 * the minimum cycle length
  			 */
  			if (tdvs + tcyc_tdvs < tcyc)
  				tcyc_tdvs = tcyc - tdvs;
  
  			/* Mow assign the values required for the timing
  			 * registers
  			 */
  			if (tcyc_tdvs < 2)
  				tcyc_tdvs = 2;
  
  			if (tdvs < 2)
  				tdvs = 2;
  
  			tack = num_clocks_min(udma_tackmin, fsclk);
  			tss = num_clocks_min(udma_tssmin, fsclk);
  			tmli = num_clocks_min(udma_tmlimin, fsclk);
  			tzah = num_clocks_min(udma_tzahmin, fsclk);
  			trp = num_clocks_min(udma_trpmin[mode], fsclk);
  			tenv = num_clocks_min(udma_tenvmin, fsclk);
  			if (tenv <= udma_tenvmax[mode]) {
  				ATAPI_SET_ULTRA_TIM_0(base, (tenv<<8 | tack));
  				ATAPI_SET_ULTRA_TIM_1(base,
  					(tcyc_tdvs<<8 | tdvs));
  				ATAPI_SET_ULTRA_TIM_2(base, (tmli<<8 | tss));
  				ATAPI_SET_ULTRA_TIM_3(base, (trp<<8 | tzah));
  
  				/* Enable host ATAPI Untra DMA interrupts */
  				ATAPI_SET_INT_MASK(base,
  					ATAPI_GET_INT_MASK(base)
  					| UDMAIN_DONE_MASK
  					| UDMAOUT_DONE_MASK
  					| UDMAIN_TERM_MASK
  					| UDMAOUT_TERM_MASK);
  			}
  		}
  	}
  
  	mode = adev->dma_mode - XFER_MW_DMA_0;
  	if (mode >= 0 && mode <= 2) {

  		dev_dbg(adev->link->ap->dev, "set mdmamode: mode=%d
  ", mode);

  		/* the most restrictive timing value is tf, the DMACK to
  		 * read data released. If one SCLK pulse is longer than
  		 * this maximum value then the MDMA mode
  		 * cannot be supported at this frequency.
  		 */
  		while (mode > 0 && mdma_fsclk[mode] > fsclk)
  			mode--;
  
  		nf = num_clocks_min(tfmin, fsclk);
  		if (nf >= 1) {
  			/* calculate the timing values for Multi-word DMA. */
  
  			/* DIOR/DIOW asserted pulse width */
  			td = num_clocks_min(mdma_tdmin[mode], fsclk);
  
  			/* DIOR negated pulse width */
  			tkw = num_clocks_min(mdma_tkwmin[mode], fsclk);
  
  			/* Cycle Time */
  			n0  = num_clocks_min(mdma_t0min[mode], fsclk);
  
  			/* increase tk until we meed the minimum cycle length */
  			if (tkw + td < n0)
  				tkw = n0 - td;
  
  			/* DIOR negated pulse width - read */
  			tkr = num_clocks_min(mdma_tkrmin[mode], fsclk);
  			/* CS{1:0] valid to DIOR/DIOW */
  			tm = num_clocks_min(mdma_tmmin[mode], fsclk);
  			/* DIOR/DIOW to DMACK hold */
  			teoc = num_clocks_min(mdma_tjmin[mode], fsclk);
  			/* DIOW Data hold */
  			th = num_clocks_min(mdma_thmin[mode], fsclk);
  
  			ATAPI_SET_MULTI_TIM_0(base, (tm<<8 | td));
  			ATAPI_SET_MULTI_TIM_1(base, (tkr<<8 | tkw));
  			ATAPI_SET_MULTI_TIM_2(base, (teoc<<8 | th));
  
  			/* Enable host ATAPI Multi DMA interrupts */
  			ATAPI_SET_INT_MASK(base, ATAPI_GET_INT_MASK(base)
  				| MULTI_DONE_MASK | MULTI_TERM_MASK);
  			SSYNC();
  		}
  	}
  	return;
  }
  
  /**
   *
   *    Function:       wait_complete
   *
   *    Description:    Waits the interrupt from device
   *
   */
  static inline void wait_complete(void __iomem *base, unsigned short mask)
  {
  	unsigned short status;
  	unsigned int i = 0;
  
  #define PATA_BF54X_WAIT_TIMEOUT		10000
  
  	for (i = 0; i < PATA_BF54X_WAIT_TIMEOUT; i++) {
  		status = ATAPI_GET_INT_STATUS(base) & mask;
  		if (status)
  			break;
  	}
  
  	ATAPI_SET_INT_STATUS(base, mask);
  }
  
  /**
   *
   *    Function:       write_atapi_register
   *
   *    Description:    Writes to ATA Device Resgister
   *
   */
  
  static void write_atapi_register(void __iomem *base,
  		unsigned long ata_reg, unsigned short value)
  {
  	/* Program the ATA_DEV_TXBUF register with write data (to be
  	 * written into the device).
  	 */
  	ATAPI_SET_DEV_TXBUF(base, value);
  
  	/* Program the ATA_DEV_ADDR register with address of the
  	 * device register (0x01 to 0x0F).
  	 */
  	ATAPI_SET_DEV_ADDR(base, ata_reg);
  
  	/* Program the ATA_CTRL register with dir set to write (1)
  	 */
  	ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) | XFER_DIR));
  
  	/* ensure PIO DMA is not set */
  	ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) & ~PIO_USE_DMA));
  
  	/* and start the transfer */
  	ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) | PIO_START));
  
  	/* Wait for the interrupt to indicate the end of the transfer.
  	 * (We need to wait on and clear rhe ATA_DEV_INT interrupt status)
  	 */
  	wait_complete(base, PIO_DONE_INT);
  }
  
  /**
   *
   *	Function:       read_atapi_register
   *
   *Description:    Reads from ATA Device Resgister
   *
   */
  
  static unsigned short read_atapi_register(void __iomem *base,
  		unsigned long ata_reg)
  {
  	/* Program the ATA_DEV_ADDR register with address of the
  	 * device register (0x01 to 0x0F).
  	 */
  	ATAPI_SET_DEV_ADDR(base, ata_reg);
  
  	/* Program the ATA_CTRL register with dir set to read (0) and
  	 */
  	ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) & ~XFER_DIR));
  
  	/* ensure PIO DMA is not set */
  	ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) & ~PIO_USE_DMA));
  
  	/* and start the transfer */
  	ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) | PIO_START));
  
  	/* Wait for the interrupt to indicate the end of the transfer.
  	 * (PIO_DONE interrupt is set and it doesn't seem to matter
  	 * that we don't clear it)
  	 */
  	wait_complete(base, PIO_DONE_INT);
  
  	/* Read the ATA_DEV_RXBUF register with write data (to be
  	 * written into the device).
  	 */
  	return ATAPI_GET_DEV_RXBUF(base);
  }
  
  /**
   *
   *    Function:       write_atapi_register_data
   *
   *    Description:    Writes to ATA Device Resgister
   *
   */
  
  static void write_atapi_data(void __iomem *base,
  		int len, unsigned short *buf)
  {
  	int i;
  
  	/* Set transfer length to 1 */
  	ATAPI_SET_XFER_LEN(base, 1);
  
  	/* Program the ATA_DEV_ADDR register with address of the
  	 * ATA_REG_DATA
  	 */
  	ATAPI_SET_DEV_ADDR(base, ATA_REG_DATA);
  
  	/* Program the ATA_CTRL register with dir set to write (1)
  	 */
  	ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) | XFER_DIR));
  
  	/* ensure PIO DMA is not set */
  	ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) & ~PIO_USE_DMA));
  
  	for (i = 0; i < len; i++) {
  		/* Program the ATA_DEV_TXBUF register with write data (to be
  		 * written into the device).
  		 */
  		ATAPI_SET_DEV_TXBUF(base, buf[i]);
  
  		/* and start the transfer */
  		ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) | PIO_START));
  
  		/* Wait for the interrupt to indicate the end of the transfer.
  		 * (We need to wait on and clear rhe ATA_DEV_INT
  		 * interrupt status)
  		 */
  		wait_complete(base, PIO_DONE_INT);
  	}
  }
  
  /**
   *
   *	Function:       read_atapi_register_data
   *
   *	Description:    Reads from ATA Device Resgister
   *
   */
  
  static void read_atapi_data(void __iomem *base,
  		int len, unsigned short *buf)
  {
  	int i;
  
  	/* Set transfer length to 1 */
  	ATAPI_SET_XFER_LEN(base, 1);
  
  	/* Program the ATA_DEV_ADDR register with address of the
  	 * ATA_REG_DATA
  	 */
  	ATAPI_SET_DEV_ADDR(base, ATA_REG_DATA);
  
  	/* Program the ATA_CTRL register with dir set to read (0) and
  	 */
  	ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) & ~XFER_DIR));
  
  	/* ensure PIO DMA is not set */
  	ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) & ~PIO_USE_DMA));
  
  	for (i = 0; i < len; i++) {
  		/* and start the transfer */
  		ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) | PIO_START));
  
  		/* Wait for the interrupt to indicate the end of the transfer.
  		 * (PIO_DONE interrupt is set and it doesn't seem to matter
  		 * that we don't clear it)
  		 */
  		wait_complete(base, PIO_DONE_INT);
  
  		/* Read the ATA_DEV_RXBUF register with write data (to be
  		 * written into the device).
  		 */
  		buf[i] = ATAPI_GET_DEV_RXBUF(base);
  	}
  }
  
  /**
   *	bfin_tf_load - send taskfile registers to host controller
   *	@ap: Port to which output is sent
   *	@tf: ATA taskfile register set
   *

   *	Note: Original code is ata_sff_tf_load().

   */
  
  static void bfin_tf_load(struct ata_port *ap, const struct ata_taskfile *tf)
  {
  	void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
  	unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;
  
  	if (tf->ctl != ap->last_ctl) {
  		write_atapi_register(base, ATA_REG_CTRL, tf->ctl);
  		ap->last_ctl = tf->ctl;
  		ata_wait_idle(ap);
  	}
  
  	if (is_addr) {
  		if (tf->flags & ATA_TFLAG_LBA48) {
  			write_atapi_register(base, ATA_REG_FEATURE,
  						tf->hob_feature);
  			write_atapi_register(base, ATA_REG_NSECT,
  						tf->hob_nsect);
  			write_atapi_register(base, ATA_REG_LBAL, tf->hob_lbal);
  			write_atapi_register(base, ATA_REG_LBAM, tf->hob_lbam);
  			write_atapi_register(base, ATA_REG_LBAH, tf->hob_lbah);

  			dev_dbg(ap->dev, "hob: feat 0x%X nsect 0x%X, lba 0x%X "

  				 "0x%X 0x%X
  ",
  				tf->hob_feature,
  				tf->hob_nsect,
  				tf->hob_lbal,
  				tf->hob_lbam,
  				tf->hob_lbah);
  		}
  
  		write_atapi_register(base, ATA_REG_FEATURE, tf->feature);
  		write_atapi_register(base, ATA_REG_NSECT, tf->nsect);
  		write_atapi_register(base, ATA_REG_LBAL, tf->lbal);
  		write_atapi_register(base, ATA_REG_LBAM, tf->lbam);
  		write_atapi_register(base, ATA_REG_LBAH, tf->lbah);

  		dev_dbg(ap->dev, "feat 0x%X nsect 0x%X lba 0x%X 0x%X 0x%X
  ",

  			tf->feature,
  			tf->nsect,
  			tf->lbal,
  			tf->lbam,
  			tf->lbah);
  	}
  
  	if (tf->flags & ATA_TFLAG_DEVICE) {
  		write_atapi_register(base, ATA_REG_DEVICE, tf->device);

  		dev_dbg(ap->dev, "device 0x%X
  ", tf->device);

  	}
  
  	ata_wait_idle(ap);
  }
  
  /**
   *	bfin_check_status - Read device status reg & clear interrupt
   *	@ap: port where the device is
   *
   *	Note: Original code is ata_check_status().
   */
  
  static u8 bfin_check_status(struct ata_port *ap)
  {
  	void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
  	return read_atapi_register(base, ATA_REG_STATUS);
  }
  
  /**
   *	bfin_tf_read - input device's ATA taskfile shadow registers
   *	@ap: Port from which input is read
   *	@tf: ATA taskfile register set for storing input
   *

   *	Note: Original code is ata_sff_tf_read().

   */
  
  static void bfin_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
  {
  	void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
  
  	tf->command = bfin_check_status(ap);
  	tf->feature = read_atapi_register(base, ATA_REG_ERR);
  	tf->nsect = read_atapi_register(base, ATA_REG_NSECT);
  	tf->lbal = read_atapi_register(base, ATA_REG_LBAL);
  	tf->lbam = read_atapi_register(base, ATA_REG_LBAM);
  	tf->lbah = read_atapi_register(base, ATA_REG_LBAH);
  	tf->device = read_atapi_register(base, ATA_REG_DEVICE);
  
  	if (tf->flags & ATA_TFLAG_LBA48) {
  		write_atapi_register(base, ATA_REG_CTRL, tf->ctl | ATA_HOB);
  		tf->hob_feature = read_atapi_register(base, ATA_REG_ERR);
  		tf->hob_nsect = read_atapi_register(base, ATA_REG_NSECT);
  		tf->hob_lbal = read_atapi_register(base, ATA_REG_LBAL);
  		tf->hob_lbam = read_atapi_register(base, ATA_REG_LBAM);
  		tf->hob_lbah = read_atapi_register(base, ATA_REG_LBAH);
  	}
  }
  
  /**
   *	bfin_exec_command - issue ATA command to host controller
   *	@ap: port to which command is being issued
   *	@tf: ATA taskfile register set
   *

   *	Note: Original code is ata_sff_exec_command().

   */
  
  static void bfin_exec_command(struct ata_port *ap,
  			      const struct ata_taskfile *tf)
  {
  	void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;

  	dev_dbg(ap->dev, "ata%u: cmd 0x%X
  ", ap->print_id, tf->command);

  
  	write_atapi_register(base, ATA_REG_CMD, tf->command);

  	ata_sff_pause(ap);

  }
  
  /**
   *	bfin_check_altstatus - Read device alternate status reg
   *	@ap: port where the device is
   */
  
  static u8 bfin_check_altstatus(struct ata_port *ap)
  {
  	void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
  	return read_atapi_register(base, ATA_REG_ALTSTATUS);
  }
  
  /**

   *	bfin_dev_select - Select device 0/1 on ATA bus

   *	@ap: ATA channel to manipulate
   *	@device: ATA device (numbered from zero) to select
   *

   *	Note: Original code is ata_sff_dev_select().

   */

  static void bfin_dev_select(struct ata_port *ap, unsigned int device)

  {
  	void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
  	u8 tmp;
  
  	if (device == 0)
  		tmp = ATA_DEVICE_OBS;
  	else
  		tmp = ATA_DEVICE_OBS | ATA_DEV1;
  
  	write_atapi_register(base, ATA_REG_DEVICE, tmp);

  	ata_sff_pause(ap);

  }
  
  /**

   *	bfin_set_devctl - Write device control reg
   *	@ap: port where the device is
   *	@ctl: value to write
   */

  static void bfin_set_devctl(struct ata_port *ap, u8 ctl)

  {
  	void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
  	write_atapi_register(base, ATA_REG_CTRL, ctl);
  }
  
  /**

   *	bfin_bmdma_setup - Set up IDE DMA transaction
   *	@qc: Info associated with this ATA transaction.
   *
   *	Note: Original code is ata_bmdma_setup().
   */
  
  static void bfin_bmdma_setup(struct ata_queued_cmd *qc)
  {
  	unsigned short config = WDSIZE_16;
  	struct scatterlist *sg;

  	unsigned int si;

  	dev_dbg(qc->ap->dev, "in atapi dma setup
  ");

  	/* Program the ATA_CTRL register with dir */
  	if (qc->tf.flags & ATA_TFLAG_WRITE) {
  		/* fill the ATAPI DMA controller */
  		set_dma_config(CH_ATAPI_TX, config);
  		set_dma_x_modify(CH_ATAPI_TX, 2);

  		for_each_sg(qc->sg, sg, qc->n_elem, si) {

  			set_dma_start_addr(CH_ATAPI_TX, sg_dma_address(sg));
  			set_dma_x_count(CH_ATAPI_TX, sg_dma_len(sg) >> 1);
  		}
  	} else {
  		config |= WNR;
  		/* fill the ATAPI DMA controller */
  		set_dma_config(CH_ATAPI_RX, config);
  		set_dma_x_modify(CH_ATAPI_RX, 2);

  		for_each_sg(qc->sg, sg, qc->n_elem, si) {

  			set_dma_start_addr(CH_ATAPI_RX, sg_dma_address(sg));
  			set_dma_x_count(CH_ATAPI_RX, sg_dma_len(sg) >> 1);
  		}
  	}
  }
  
  /**
   *	bfin_bmdma_start - Start an IDE DMA transaction
   *	@qc: Info associated with this ATA transaction.
   *
   *	Note: Original code is ata_bmdma_start().
   */
  
  static void bfin_bmdma_start(struct ata_queued_cmd *qc)
  {
  	struct ata_port *ap = qc->ap;
  	void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
  	struct scatterlist *sg;

  	unsigned int si;

  	dev_dbg(qc->ap->dev, "in atapi dma start
  ");

  	if (!(ap->udma_mask || ap->mwdma_mask))
  		return;
  
  	/* start ATAPI DMA controller*/
  	if (qc->tf.flags & ATA_TFLAG_WRITE) {
  		/*
  		 * On blackfin arch, uncacheable memory is not
  		 * allocated with flag GFP_DMA. DMA buffer from
  		 * common kenel code should be flushed if WB
  		 * data cache is enabled. Otherwise, this loop
  		 * is an empty loop and optimized out.
  		 */

  		for_each_sg(qc->sg, sg, qc->n_elem, si) {

  			flush_dcache_range(sg_dma_address(sg),
  				sg_dma_address(sg) + sg_dma_len(sg));
  		}
  		enable_dma(CH_ATAPI_TX);

  		dev_dbg(qc->ap->dev, "enable udma write
  ");

  
  		/* Send ATA DMA write command */
  		bfin_exec_command(ap, &qc->tf);
  
  		/* set ATA DMA write direction */
  		ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base)
  			| XFER_DIR));
  	} else {
  		enable_dma(CH_ATAPI_RX);

  		dev_dbg(qc->ap->dev, "enable udma read
  ");

  
  		/* Send ATA DMA read command */
  		bfin_exec_command(ap, &qc->tf);
  
  		/* set ATA DMA read direction */
  		ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base)
  			& ~XFER_DIR));
  	}
  
  	/* Reset all transfer count */
  	ATAPI_SET_CONTROL(base, ATAPI_GET_CONTROL(base) | TFRCNT_RST);

  	/* Set ATAPI state machine contorl in terminate sequence */
  	ATAPI_SET_CONTROL(base, ATAPI_GET_CONTROL(base) | END_ON_TERM);
  
  	/* Set transfer length to buffer len */

  	for_each_sg(qc->sg, sg, qc->n_elem, si) {

  		ATAPI_SET_XFER_LEN(base, (sg_dma_len(sg) >> 1));
  	}
  
  	/* Enable ATA DMA operation*/
  	if (ap->udma_mask)
  		ATAPI_SET_CONTROL(base, ATAPI_GET_CONTROL(base)
  			| ULTRA_START);
  	else
  		ATAPI_SET_CONTROL(base, ATAPI_GET_CONTROL(base)
  			| MULTI_START);
  }
  
  /**
   *	bfin_bmdma_stop - Stop IDE DMA transfer
   *	@qc: Command we are ending DMA for
   */
  
  static void bfin_bmdma_stop(struct ata_queued_cmd *qc)
  {
  	struct ata_port *ap = qc->ap;
  	struct scatterlist *sg;

  	unsigned int si;

  	dev_dbg(qc->ap->dev, "in atapi dma stop
  ");

  	if (!(ap->udma_mask || ap->mwdma_mask))
  		return;
  
  	/* stop ATAPI DMA controller*/
  	if (qc->tf.flags & ATA_TFLAG_WRITE)
  		disable_dma(CH_ATAPI_TX);
  	else {
  		disable_dma(CH_ATAPI_RX);
  		if (ap->hsm_task_state & HSM_ST_LAST) {
  			/*
  			 * On blackfin arch, uncacheable memory is not
  			 * allocated with flag GFP_DMA. DMA buffer from
  			 * common kenel code should be invalidated if
  			 * data cache is enabled. Otherwise, this loop
  			 * is an empty loop and optimized out.
  			 */

  			for_each_sg(qc->sg, sg, qc->n_elem, si) {

  				invalidate_dcache_range(
  					sg_dma_address(sg),
  					sg_dma_address(sg)
  					+ sg_dma_len(sg));
  			}
  		}
  	}
  }
  
  /**
   *	bfin_devchk - PATA device presence detection
   *	@ap: ATA channel to examine
   *	@device: Device to examine (starting at zero)
   *
   *	Note: Original code is ata_devchk().
   */
  
  static unsigned int bfin_devchk(struct ata_port *ap,
  				unsigned int device)
  {
  	void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
  	u8 nsect, lbal;

  	bfin_dev_select(ap, device);

  
  	write_atapi_register(base, ATA_REG_NSECT, 0x55);
  	write_atapi_register(base, ATA_REG_LBAL, 0xaa);
  
  	write_atapi_register(base, ATA_REG_NSECT, 0xaa);
  	write_atapi_register(base, ATA_REG_LBAL, 0x55);
  
  	write_atapi_register(base, ATA_REG_NSECT, 0x55);
  	write_atapi_register(base, ATA_REG_LBAL, 0xaa);
  
  	nsect = read_atapi_register(base, ATA_REG_NSECT);
  	lbal = read_atapi_register(base, ATA_REG_LBAL);
  
  	if ((nsect == 0x55) && (lbal == 0xaa))
  		return 1;	/* we found a device */
  
  	return 0;		/* nothing found */
  }
  
  /**
   *	bfin_bus_post_reset - PATA device post reset
   *
   *	Note: Original code is ata_bus_post_reset().
   */
  
  static void bfin_bus_post_reset(struct ata_port *ap, unsigned int devmask)
  {
  	void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
  	unsigned int dev0 = devmask & (1 << 0);
  	unsigned int dev1 = devmask & (1 << 1);

  	unsigned long deadline;

  
  	/* if device 0 was found in ata_devchk, wait for its
  	 * BSY bit to clear
  	 */
  	if (dev0)

  		ata_sff_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT);

  
  	/* if device 1 was found in ata_devchk, wait for
  	 * register access, then wait for BSY to clear
  	 */

  	deadline = ata_deadline(jiffies, ATA_TMOUT_BOOT);

  	while (dev1) {
  		u8 nsect, lbal;

  		bfin_dev_select(ap, 1);

  		nsect = read_atapi_register(base, ATA_REG_NSECT);
  		lbal = read_atapi_register(base, ATA_REG_LBAL);
  		if ((nsect == 1) && (lbal == 1))
  			break;

  		if (time_after(jiffies, deadline)) {

  			dev1 = 0;
  			break;
  		}

  		ata_msleep(ap, 50);	/* give drive a breather */

  	}
  	if (dev1)

  		ata_sff_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT);

  
  	/* is all this really necessary? */

  	bfin_dev_select(ap, 0);

  	if (dev1)

  		bfin_dev_select(ap, 1);

  	if (dev0)

  		bfin_dev_select(ap, 0);

  }
  
  /**
   *	bfin_bus_softreset - PATA device software reset
   *
   *	Note: Original code is ata_bus_softreset().
   */
  
  static unsigned int bfin_bus_softreset(struct ata_port *ap,
  				       unsigned int devmask)
  {
  	void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
  
  	/* software reset.  causes dev0 to be selected */
  	write_atapi_register(base, ATA_REG_CTRL, ap->ctl);
  	udelay(20);
  	write_atapi_register(base, ATA_REG_CTRL, ap->ctl | ATA_SRST);
  	udelay(20);
  	write_atapi_register(base, ATA_REG_CTRL, ap->ctl);
  
  	/* spec mandates ">= 2ms" before checking status.
  	 * We wait 150ms, because that was the magic delay used for
  	 * ATAPI devices in Hale Landis's ATADRVR, for the period of time
  	 * between when the ATA command register is written, and then
  	 * status is checked.  Because waiting for "a while" before
  	 * checking status is fine, post SRST, we perform this magic
  	 * delay here as well.
  	 *
  	 * Old drivers/ide uses the 2mS rule and then waits for ready
  	 */

  	ata_msleep(ap, 150);

  
  	/* Before we perform post reset processing we want to see if
  	 * the bus shows 0xFF because the odd clown forgets the D7
  	 * pulldown resistor.
  	 */
  	if (bfin_check_status(ap) == 0xFF)
  		return 0;
  
  	bfin_bus_post_reset(ap, devmask);
  
  	return 0;
  }
  
  /**

   *	bfin_softreset - reset host port via ATA SRST

   *	@ap: port to reset
   *	@classes: resulting classes of attached devices
   *

   *	Note: Original code is ata_sff_softreset().

   */

  static int bfin_softreset(struct ata_link *link, unsigned int *classes,
  			  unsigned long deadline)

  {

  	struct ata_port *ap = link->ap;

  	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
  	unsigned int devmask = 0, err_mask;
  	u8 err;

  	/* determine if device 0/1 are present */
  	if (bfin_devchk(ap, 0))
  		devmask |= (1 << 0);
  	if (slave_possible && bfin_devchk(ap, 1))
  		devmask |= (1 << 1);
  
  	/* select device 0 again */

  	bfin_dev_select(ap, 0);

  
  	/* issue bus reset */
  	err_mask = bfin_bus_softreset(ap, devmask);
  	if (err_mask) {

  		ata_port_err(ap, "SRST failed (err_mask=0x%x)
  ",

  				err_mask);
  		return -EIO;
  	}
  
  	/* determine by signature whether we have ATA or ATAPI devices */

  	classes[0] = ata_sff_dev_classify(&ap->link.device[0],

  				devmask & (1 << 0), &err);

  	if (slave_possible && err != 0x81)

  		classes[1] = ata_sff_dev_classify(&ap->link.device[1],

  					devmask & (1 << 1), &err);

  	return 0;
  }
  
  /**
   *	bfin_bmdma_status - Read IDE DMA status
   *	@ap: Port associated with this ATA transaction.
   */
  
  static unsigned char bfin_bmdma_status(struct ata_port *ap)
  {
  	unsigned char host_stat = 0;
  	void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
  	unsigned short int_status = ATAPI_GET_INT_STATUS(base);

  	if (ATAPI_GET_STATUS(base) & (MULTI_XFER_ON|ULTRA_XFER_ON))

  		host_stat |= ATA_DMA_ACTIVE;

  	if (int_status & (MULTI_DONE_INT|UDMAIN_DONE_INT|UDMAOUT_DONE_INT|
  		ATAPI_DEV_INT))

  		host_stat |= ATA_DMA_INTR;

  	if (int_status & (MULTI_TERM_INT|UDMAIN_TERM_INT|UDMAOUT_TERM_INT))
  		host_stat |= ATA_DMA_ERR|ATA_DMA_INTR;

  	dev_dbg(ap->dev, "ATAPI: host_stat=0x%x
  ", host_stat);

  	return host_stat;
  }
  
  /**
   *	bfin_data_xfer - Transfer data by PIO
   *	@adev: device for this I/O
   *	@buf: data buffer
   *	@buflen: buffer length
   *	@write_data: read/write
   *

   *	Note: Original code is ata_sff_data_xfer().

   */

  static unsigned int bfin_data_xfer(struct ata_device *dev, unsigned char *buf,
  				   unsigned int buflen, int rw)

  {

  	struct ata_port *ap = dev->link->ap;

  	void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;

  	unsigned int words = buflen >> 1;
  	unsigned short *buf16 = (u16 *)buf;

  
  	/* Transfer multiple of 2 bytes */

  	if (rw == READ)

  		read_atapi_data(base, words, buf16);

  	else
  		write_atapi_data(base, words, buf16);

  
  	/* Transfer trailing 1 byte, if any. */
  	if (unlikely(buflen & 0x01)) {
  		unsigned short align_buf[1] = { 0 };
  		unsigned char *trailing_buf = buf + buflen - 1;

  		if (rw == READ) {

  			read_atapi_data(base, 1, align_buf);
  			memcpy(trailing_buf, align_buf, 1);

  		} else {
  			memcpy(align_buf, trailing_buf, 1);
  			write_atapi_data(base, 1, align_buf);

  		}

  		words++;

  	}

  
  	return words << 1;

  }
  
  /**
   *	bfin_irq_clear - Clear ATAPI interrupt.
   *	@ap: Port associated with this ATA transaction.
   *

   *	Note: Original code is ata_bmdma_irq_clear().

   */
  
  static void bfin_irq_clear(struct ata_port *ap)
  {
  	void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;

  	dev_dbg(ap->dev, "in atapi irq clear
  ");

  	ATAPI_SET_INT_STATUS(base, ATAPI_GET_INT_STATUS(base)|ATAPI_DEV_INT
  		| MULTI_DONE_INT | UDMAIN_DONE_INT | UDMAOUT_DONE_INT
  		| MULTI_TERM_INT | UDMAIN_TERM_INT | UDMAOUT_TERM_INT);

  }
  
  /**

   *	bfin_thaw - Thaw DMA controller port

   *	@ap: port to thaw
   *

   *	Note: Original code is ata_sff_thaw().

   */

  void bfin_thaw(struct ata_port *ap)

  {

  	dev_dbg(ap->dev, "in atapi dma thaw
  ");

  	bfin_check_status(ap);

  	ata_sff_irq_on(ap);

  }
  
  /**

   *	bfin_postreset - standard postreset callback

   *	@ap: the target ata_port
   *	@classes: classes of attached devices
   *

   *	Note: Original code is ata_sff_postreset().

   */

  static void bfin_postreset(struct ata_link *link, unsigned int *classes)

  {

  	struct ata_port *ap = link->ap;

  	void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
  
  	/* re-enable interrupts */

  	ata_sff_irq_on(ap);

  
  	/* is double-select really necessary? */
  	if (classes[0] != ATA_DEV_NONE)

  		bfin_dev_select(ap, 1);

  	if (classes[1] != ATA_DEV_NONE)

  		bfin_dev_select(ap, 0);

  
  	/* bail out if no device is present */
  	if (classes[0] == ATA_DEV_NONE && classes[1] == ATA_DEV_NONE) {
  		return;
  	}
  
  	/* set up device control */
  	write_atapi_register(base, ATA_REG_CTRL, ap->ctl);
  }

  static void bfin_port_stop(struct ata_port *ap)
  {

  	dev_dbg(ap->dev, "in atapi port stop
  ");

  	if (ap->udma_mask != 0 || ap->mwdma_mask != 0) {
  		free_dma(CH_ATAPI_RX);
  		free_dma(CH_ATAPI_TX);
  	}
  }
  
  static int bfin_port_start(struct ata_port *ap)
  {

  	dev_dbg(ap->dev, "in atapi port start
  ");

  	if (!(ap->udma_mask || ap->mwdma_mask))
  		return 0;
  
  	if (request_dma(CH_ATAPI_RX, "BFIN ATAPI RX DMA") >= 0) {
  		if (request_dma(CH_ATAPI_TX,
  			"BFIN ATAPI TX DMA") >= 0)
  			return 0;
  
  		free_dma(CH_ATAPI_RX);
  	}
  
  	ap->udma_mask = 0;
  	ap->mwdma_mask = 0;
  	dev_err(ap->dev, "Unable to request ATAPI DMA!"
  		" Continue in PIO mode.
  ");
  
  	return 0;
  }

  static unsigned int bfin_ata_host_intr(struct ata_port *ap,
  				   struct ata_queued_cmd *qc)
  {
  	struct ata_eh_info *ehi = &ap->link.eh_info;
  	u8 status, host_stat = 0;
  
  	VPRINTK("ata%u: protocol %d task_state %d
  ",
  		ap->print_id, qc->tf.protocol, ap->hsm_task_state);
  
  	/* Check whether we are expecting interrupt in this state */
  	switch (ap->hsm_task_state) {
  	case HSM_ST_FIRST:
  		/* Some pre-ATAPI-4 devices assert INTRQ
  		 * at this state when ready to receive CDB.
  		 */
  
  		/* Check the ATA_DFLAG_CDB_INTR flag is enough here.
  		 * The flag was turned on only for atapi devices.
  		 * No need to check is_atapi_taskfile(&qc->tf) again.
  		 */
  		if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
  			goto idle_irq;
  		break;
  	case HSM_ST_LAST:
  		if (qc->tf.protocol == ATA_PROT_DMA ||
  		    qc->tf.protocol == ATAPI_PROT_DMA) {
  			/* check status of DMA engine */
  			host_stat = ap->ops->bmdma_status(ap);
  			VPRINTK("ata%u: host_stat 0x%X
  ",
  				ap->print_id, host_stat);
  
  			/* if it's not our irq... */
  			if (!(host_stat & ATA_DMA_INTR))
  				goto idle_irq;
  
  			/* before we do anything else, clear DMA-Start bit */
  			ap->ops->bmdma_stop(qc);
  
  			if (unlikely(host_stat & ATA_DMA_ERR)) {

  				/* error when transferring data to/from memory */

  				qc->err_mask |= AC_ERR_HOST_BUS;
  				ap->hsm_task_state = HSM_ST_ERR;
  			}
  		}
  		break;
  	case HSM_ST:
  		break;
  	default:
  		goto idle_irq;
  	}
  
  	/* check altstatus */
  	status = ap->ops->sff_check_altstatus(ap);
  	if (status & ATA_BUSY)
  		goto busy_ata;
  
  	/* check main status, clearing INTRQ */
  	status = ap->ops->sff_check_status(ap);
  	if (unlikely(status & ATA_BUSY))
  		goto busy_ata;
  
  	/* ack bmdma irq events */
  	ap->ops->sff_irq_clear(ap);
  
  	ata_sff_hsm_move(ap, qc, status, 0);
  
  	if (unlikely(qc->err_mask) && (qc->tf.protocol == ATA_PROT_DMA ||
  				       qc->tf.protocol == ATAPI_PROT_DMA))
  		ata_ehi_push_desc(ehi, "BMDMA stat 0x%x", host_stat);
  
  busy_ata:
  	return 1;	/* irq handled */
  
  idle_irq:
  	ap->stats.idle_irq++;
  
  #ifdef ATA_IRQ_TRAP
  	if ((ap->stats.idle_irq % 1000) == 0) {
  		ap->ops->irq_ack(ap, 0); /* debug trap */

  		ata_port_warn(ap, "irq trap
  ");

  		return 1;
  	}
  #endif
  	return 0;	/* irq not handled */
  }
  
  static irqreturn_t bfin_ata_interrupt(int irq, void *dev_instance)
  {
  	struct ata_host *host = dev_instance;
  	unsigned int i;
  	unsigned int handled = 0;
  	unsigned long flags;
  
  	/* TODO: make _irqsave conditional on x86 PCI IDE legacy mode */
  	spin_lock_irqsave(&host->lock, flags);
  
  	for (i = 0; i < host->n_ports; i++) {

  		struct ata_port *ap = host->ports[i];
  		struct ata_queued_cmd *qc;

  		qc = ata_qc_from_tag(ap, ap->link.active_tag);
  		if (qc && (!(qc->tf.flags & ATA_TFLAG_POLLING)))
  			handled |= bfin_ata_host_intr(ap, qc);

  	}
  
  	spin_unlock_irqrestore(&host->lock, flags);
  
  	return IRQ_RETVAL(handled);
  }

  static struct scsi_host_template bfin_sht = {

  	ATA_BASE_SHT(DRV_NAME),

  	.sg_tablesize		= SG_NONE,

  	.dma_boundary		= ATA_DMA_BOUNDARY,

  };

  static struct ata_port_operations bfin_pata_ops = {

  	.inherits		= &ata_bmdma_port_ops,

  	.set_piomode		= bfin_set_piomode,
  	.set_dmamode		= bfin_set_dmamode,

  	.sff_tf_load		= bfin_tf_load,
  	.sff_tf_read		= bfin_tf_read,
  	.sff_exec_command	= bfin_exec_command,
  	.sff_check_status	= bfin_check_status,
  	.sff_check_altstatus	= bfin_check_altstatus,
  	.sff_dev_select		= bfin_dev_select,

  	.sff_set_devctl		= bfin_set_devctl,

  
  	.bmdma_setup		= bfin_bmdma_setup,
  	.bmdma_start		= bfin_bmdma_start,
  	.bmdma_stop		= bfin_bmdma_stop,
  	.bmdma_status		= bfin_bmdma_status,

  	.sff_data_xfer		= bfin_data_xfer,

  
  	.qc_prep		= ata_noop_qc_prep,

  	.thaw			= bfin_thaw,
  	.softreset		= bfin_softreset,
  	.postreset		= bfin_postreset,

  	.sff_irq_clear		= bfin_irq_clear,

  
  	.port_start		= bfin_port_start,
  	.port_stop		= bfin_port_stop,
  };
  
  static struct ata_port_info bfin_port_info[] = {
  	{

  		.flags		= ATA_FLAG_SLAVE_POSS,

  		.pio_mask	= ATA_PIO4,

  		.mwdma_mask	= 0,

  		.udma_mask	= 0,

  		.port_ops	= &bfin_pata_ops,
  	},
  };
  
  /**
   *	bfin_reset_controller - initialize BF54x ATAPI controller.
   */
  
  static int bfin_reset_controller(struct ata_host *host)
  {
  	void __iomem *base = (void __iomem *)host->ports[0]->ioaddr.ctl_addr;
  	int count;
  	unsigned short status;
  
  	/* Disable all ATAPI interrupts */
  	ATAPI_SET_INT_MASK(base, 0);
  	SSYNC();
  
  	/* Assert the RESET signal 25us*/
  	ATAPI_SET_CONTROL(base, ATAPI_GET_CONTROL(base) | DEV_RST);
  	udelay(30);
  
  	/* Negate the RESET signal for 2ms*/
  	ATAPI_SET_CONTROL(base, ATAPI_GET_CONTROL(base) & ~DEV_RST);
  	msleep(2);
  
  	/* Wait on Busy flag to clear */
  	count = 10000000;
  	do {
  		status = read_atapi_register(base, ATA_REG_STATUS);

  	} while (--count && (status & ATA_BUSY));

  
  	/* Enable only ATAPI Device interrupt */
  	ATAPI_SET_INT_MASK(base, 1);
  	SSYNC();
  
  	return (!count);
  }
  
  /**
   *	atapi_io_port - define atapi peripheral port pins.
   */
  static unsigned short atapi_io_port[] = {
  	P_ATAPI_RESET,
  	P_ATAPI_DIOR,
  	P_ATAPI_DIOW,
  	P_ATAPI_CS0,
  	P_ATAPI_CS1,
  	P_ATAPI_DMACK,
  	P_ATAPI_DMARQ,
  	P_ATAPI_INTRQ,
  	P_ATAPI_IORDY,

  	P_ATAPI_D0A,
  	P_ATAPI_D1A,
  	P_ATAPI_D2A,
  	P_ATAPI_D3A,
  	P_ATAPI_D4A,
  	P_ATAPI_D5A,
  	P_ATAPI_D6A,
  	P_ATAPI_D7A,
  	P_ATAPI_D8A,
  	P_ATAPI_D9A,
  	P_ATAPI_D10A,
  	P_ATAPI_D11A,
  	P_ATAPI_D12A,
  	P_ATAPI_D13A,
  	P_ATAPI_D14A,
  	P_ATAPI_D15A,
  	P_ATAPI_A0A,
  	P_ATAPI_A1A,
  	P_ATAPI_A2A,

  	0
  };
  
  /**
   *	bfin_atapi_probe	-	attach a bfin atapi interface
   *	@pdev: platform device
   *
   *	Register a bfin atapi interface.
   *
   *
   *	Platform devices are expected to contain 2 resources per port:
   *
   *		- I/O Base (IORESOURCE_IO)
   *		- IRQ	   (IORESOURCE_IRQ)
   *
   */
  static int __devinit bfin_atapi_probe(struct platform_device *pdev)
  {
  	int board_idx = 0;
  	struct resource *res;
  	struct ata_host *host;

  	unsigned int fsclk = get_sclk();
  	int udma_mode = 5;

  	const struct ata_port_info *ppi[] =
  		{ &bfin_port_info[board_idx], NULL };
  
  	/*
  	 * Simple resource validation ..
  	 */
  	if (unlikely(pdev->num_resources != 2)) {
  		dev_err(&pdev->dev, "invalid number of resources
  ");
  		return -EINVAL;
  	}
  
  	/*
  	 * Get the register base first
  	 */
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (res == NULL)
  		return -EINVAL;

  	while (bfin_port_info[board_idx].udma_mask > 0 &&
  			udma_fsclk[udma_mode] > fsclk) {

  		udma_mode--;
  		bfin_port_info[board_idx].udma_mask >>= 1;
  	}

  	/*
  	 * Now that that's out of the way, wire up the port..
  	 */
  	host = ata_host_alloc_pinfo(&pdev->dev, ppi, 1);
  	if (!host)
  		return -ENOMEM;
  
  	host->ports[0]->ioaddr.ctl_addr = (void *)res->start;
  
  	if (peripheral_request_list(atapi_io_port, "atapi-io-port")) {

  		dev_err(&pdev->dev, "Requesting Peripherals failed
  ");

  		return -EFAULT;
  	}
  
  	if (bfin_reset_controller(host)) {
  		peripheral_free_list(atapi_io_port);
  		dev_err(&pdev->dev, "Fail to reset ATAPI device
  ");
  		return -EFAULT;
  	}
  
  	if (ata_host_activate(host, platform_get_irq(pdev, 0),

  		bfin_ata_interrupt, IRQF_SHARED, &bfin_sht) != 0) {

  		peripheral_free_list(atapi_io_port);
  		dev_err(&pdev->dev, "Fail to attach ATAPI device
  ");
  		return -ENODEV;
  	}

  	dev_set_drvdata(&pdev->dev, host);

  	return 0;
  }
  
  /**
   *	bfin_atapi_remove	-	unplug a bfin atapi interface
   *	@pdev: platform device
   *
   *	A bfin atapi device has been unplugged. Perform the needed
   *	cleanup. Also called on module unload for any active devices.
   */
  static int __devexit bfin_atapi_remove(struct platform_device *pdev)
  {
  	struct device *dev = &pdev->dev;
  	struct ata_host *host = dev_get_drvdata(dev);
  
  	ata_host_detach(host);

  	dev_set_drvdata(&pdev->dev, NULL);

  
  	peripheral_free_list(atapi_io_port);
  
  	return 0;
  }
  
  #ifdef CONFIG_PM

  static int bfin_atapi_suspend(struct platform_device *pdev, pm_message_t state)

  {

  	struct ata_host *host = dev_get_drvdata(&pdev->dev);
  	if (host)
  		return ata_host_suspend(host, state);
  	else
  		return 0;

  }

  static int bfin_atapi_resume(struct platform_device *pdev)

  {

  	struct ata_host *host = dev_get_drvdata(&pdev->dev);
  	int ret;
  
  	if (host) {
  		ret = bfin_reset_controller(host);
  		if (ret) {
  			printk(KERN_ERR DRV_NAME ": Error during HW init
  ");
  			return ret;
  		}
  		ata_host_resume(host);
  	}

  	return 0;
  }

  #else
  #define bfin_atapi_suspend NULL
  #define bfin_atapi_resume NULL

  #endif
  
  static struct platform_driver bfin_atapi_driver = {
  	.probe			= bfin_atapi_probe,
  	.remove			= __devexit_p(bfin_atapi_remove),

  	.suspend		= bfin_atapi_suspend,
  	.resume			= bfin_atapi_resume,

  	.driver = {
  		.name		= DRV_NAME,
  		.owner		= THIS_MODULE,

  	},
  };

  #define ATAPI_MODE_SIZE		10
  static char bfin_atapi_mode[ATAPI_MODE_SIZE];

  static int __init bfin_atapi_init(void)
  {
  	pr_info("register bfin atapi driver
  ");

  
  	switch(bfin_atapi_mode[0]) {
  	case 'p':
  	case 'P':
  		break;
  	case 'm':
  	case 'M':
  		bfin_port_info[0].mwdma_mask = ATA_MWDMA2;
  		break;
  	default:
  		bfin_port_info[0].udma_mask = ATA_UDMA5;
  	};

  	return platform_driver_register(&bfin_atapi_driver);
  }
  
  static void __exit bfin_atapi_exit(void)
  {
  	platform_driver_unregister(&bfin_atapi_driver);
  }
  
  module_init(bfin_atapi_init);
  module_exit(bfin_atapi_exit);

  /*
   * ATAPI mode:
   * pio/PIO
   * udma/UDMA (default)
   * mwdma/MWDMA
   */
  module_param_string(bfin_atapi_mode, bfin_atapi_mode, ATAPI_MODE_SIZE, 0);

  
  MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
  MODULE_DESCRIPTION("PATA driver for blackfin 54x ATAPI controller");
  MODULE_LICENSE("GPL");
  MODULE_VERSION(DRV_VERSION);

  MODULE_ALIAS("platform:" DRV_NAME);