#include <linux/types.h>
  #include <linux/string.h>
  #include <linux/kernel.h>

  #include <linux/export.h>

  #include <linux/interrupt.h>
  #include <linux/ide.h>
  #include <linux/bitops.h>
  
  static const char *udma_str[] =
  	 { "UDMA/16", "UDMA/25",  "UDMA/33",  "UDMA/44",
  	   "UDMA/66", "UDMA/100", "UDMA/133", "UDMA7" };
  static const char *mwdma_str[] =

  	{ "MWDMA0", "MWDMA1", "MWDMA2", "MWDMA3", "MWDMA4" };

  static const char *swdma_str[] =
  	{ "SWDMA0", "SWDMA1", "SWDMA2" };
  static const char *pio_str[] =

  	{ "PIO0", "PIO1", "PIO2", "PIO3", "PIO4", "PIO5", "PIO6" };

  
  /**
   *	ide_xfer_verbose	-	return IDE mode names
   *	@mode: transfer mode
   *
   *	Returns a constant string giving the name of the mode
   *	requested.
   */
  
  const char *ide_xfer_verbose(u8 mode)
  {
  	const char *s;
  	u8 i = mode & 0xf;
  
  	if (mode >= XFER_UDMA_0 && mode <= XFER_UDMA_7)
  		s = udma_str[i];

  	else if (mode >= XFER_MW_DMA_0 && mode <= XFER_MW_DMA_4)

  		s = mwdma_str[i];
  	else if (mode >= XFER_SW_DMA_0 && mode <= XFER_SW_DMA_2)
  		s = swdma_str[i];

  	else if (mode >= XFER_PIO_0 && mode <= XFER_PIO_6)

  		s = pio_str[i & 0x7];
  	else if (mode == XFER_PIO_SLOW)
  		s = "PIO SLOW";
  	else
  		s = "XFER ERROR";
  
  	return s;
  }
  EXPORT_SYMBOL(ide_xfer_verbose);
  
  /**
   *	ide_get_best_pio_mode	-	get PIO mode from drive
   *	@drive: drive to consider
   *	@mode_wanted: preferred mode
   *	@max_mode: highest allowed mode
   *
   *	This routine returns the recommended PIO settings for a given drive,
   *	based on the drive->id information and the ide_pio_blacklist[].
   *
   *	Drive PIO mode is auto-selected if 255 is passed as mode_wanted.
   *	This is used by most chipset support modules when "auto-tuning".
   */

  static u8 ide_get_best_pio_mode(ide_drive_t *drive, u8 mode_wanted, u8 max_mode)

  {
  	u16 *id = drive->id;
  	int pio_mode = -1, overridden = 0;
  
  	if (mode_wanted != 255)
  		return min_t(u8, mode_wanted, max_mode);
  
  	if ((drive->hwif->host_flags & IDE_HFLAG_PIO_NO_BLACKLIST) == 0)
  		pio_mode = ide_scan_pio_blacklist((char *)&id[ATA_ID_PROD]);
  
  	if (pio_mode != -1) {
  		printk(KERN_INFO "%s: is on PIO blacklist
  ", drive->name);
  	} else {
  		pio_mode = id[ATA_ID_OLD_PIO_MODES] >> 8;
  		if (pio_mode > 2) {	/* 2 is maximum allowed tPIO value */
  			pio_mode = 2;
  			overridden = 1;
  		}
  
  		if (id[ATA_ID_FIELD_VALID] & 2) {	      /* ATA2? */

  			if (ata_id_is_cfa(id) && (id[ATA_ID_CFA_MODES] & 7))
  				pio_mode = 4 + min_t(int, 2,
  						     id[ATA_ID_CFA_MODES] & 7);
  			else if (ata_id_has_iordy(id)) {

  				if (id[ATA_ID_PIO_MODES] & 7) {
  					overridden = 0;
  					if (id[ATA_ID_PIO_MODES] & 4)
  						pio_mode = 5;
  					else if (id[ATA_ID_PIO_MODES] & 2)
  						pio_mode = 4;
  					else
  						pio_mode = 3;
  				}
  			}
  		}
  
  		if (overridden)
  			printk(KERN_INFO "%s: tPIO > 2, assuming tPIO = 2
  ",
  					 drive->name);
  	}
  
  	if (pio_mode > max_mode)
  		pio_mode = max_mode;
  
  	return pio_mode;
  }

  int ide_pio_need_iordy(ide_drive_t *drive, const u8 pio)
  {

  	/*
  	 * IORDY may lead to controller lock up on certain controllers
  	 * if the port is not occupied.
  	 */
  	if (pio == 0 && (drive->hwif->port_flags & IDE_PFLAG_PROBING))
  		return 0;

  	return ata_id_pio_need_iordy(drive->id, pio);
  }
  EXPORT_SYMBOL_GPL(ide_pio_need_iordy);

  int ide_set_pio_mode(ide_drive_t *drive, const u8 mode)
  {
  	ide_hwif_t *hwif = drive->hwif;
  	const struct ide_port_ops *port_ops = hwif->port_ops;
  
  	if (hwif->host_flags & IDE_HFLAG_NO_SET_MODE)
  		return 0;
  
  	if (port_ops == NULL || port_ops->set_pio_mode == NULL)
  		return -1;
  
  	/*
  	 * TODO: temporary hack for some legacy host drivers that didn't
  	 * set transfer mode on the device in ->set_pio_mode method...
  	 */
  	if (port_ops->set_dma_mode == NULL) {

  		drive->pio_mode = mode;

  		port_ops->set_pio_mode(hwif, drive);

  		return 0;
  	}
  
  	if (hwif->host_flags & IDE_HFLAG_POST_SET_MODE) {
  		if (ide_config_drive_speed(drive, mode))
  			return -1;

  		drive->pio_mode = mode;

  		port_ops->set_pio_mode(hwif, drive);

  		return 0;
  	} else {

  		drive->pio_mode = mode;

  		port_ops->set_pio_mode(hwif, drive);

  		return ide_config_drive_speed(drive, mode);
  	}
  }
  
  int ide_set_dma_mode(ide_drive_t *drive, const u8 mode)
  {
  	ide_hwif_t *hwif = drive->hwif;
  	const struct ide_port_ops *port_ops = hwif->port_ops;
  
  	if (hwif->host_flags & IDE_HFLAG_NO_SET_MODE)
  		return 0;
  
  	if (port_ops == NULL || port_ops->set_dma_mode == NULL)
  		return -1;
  
  	if (hwif->host_flags & IDE_HFLAG_POST_SET_MODE) {
  		if (ide_config_drive_speed(drive, mode))
  			return -1;

  		drive->dma_mode = mode;

  		port_ops->set_dma_mode(hwif, drive);

  		return 0;
  	} else {

  		drive->dma_mode = mode;

  		port_ops->set_dma_mode(hwif, drive);

  		return ide_config_drive_speed(drive, mode);
  	}
  }
  EXPORT_SYMBOL_GPL(ide_set_dma_mode);
  
  /* req_pio == "255" for auto-tune */
  void ide_set_pio(ide_drive_t *drive, u8 req_pio)
  {
  	ide_hwif_t *hwif = drive->hwif;
  	const struct ide_port_ops *port_ops = hwif->port_ops;
  	u8 host_pio, pio;
  
  	if (port_ops == NULL || port_ops->set_pio_mode == NULL ||
  	    (hwif->host_flags & IDE_HFLAG_NO_SET_MODE))
  		return;
  
  	BUG_ON(hwif->pio_mask == 0x00);
  
  	host_pio = fls(hwif->pio_mask) - 1;
  
  	pio = ide_get_best_pio_mode(drive, req_pio, host_pio);
  
  	/*
  	 * TODO:
  	 * - report device max PIO mode
  	 * - check req_pio != 255 against device max PIO mode
  	 */
  	printk(KERN_DEBUG "%s: host max PIO%d wanted PIO%d%s selected PIO%d
  ",
  			  drive->name, host_pio, req_pio,
  			  req_pio == 255 ? "(auto-tune)" : "", pio);
  
  	(void)ide_set_pio_mode(drive, XFER_PIO_0 + pio);
  }
  EXPORT_SYMBOL_GPL(ide_set_pio);
  
  /**
   *	ide_rate_filter		-	filter transfer mode
   *	@drive: IDE device
   *	@speed: desired speed
   *
   *	Given the available transfer modes this function returns
   *	the best available speed at or below the speed requested.
   *
   *	TODO: check device PIO capabilities
   */
  
  static u8 ide_rate_filter(ide_drive_t *drive, u8 speed)
  {
  	ide_hwif_t *hwif = drive->hwif;
  	u8 mode = ide_find_dma_mode(drive, speed);
  
  	if (mode == 0) {
  		if (hwif->pio_mask)
  			mode = fls(hwif->pio_mask) - 1 + XFER_PIO_0;
  		else
  			mode = XFER_PIO_4;
  	}
  
  /*	printk("%s: mode 0x%02x, speed 0x%02x
  ", __func__, mode, speed); */
  
  	return min(speed, mode);
  }
  
  /**
   *	ide_set_xfer_rate	-	set transfer rate
   *	@drive: drive to set
   *	@rate: speed to attempt to set
   *
   *	General helper for setting the speed of an IDE device. This
   *	function knows about user enforced limits from the configuration
   *	which ->set_pio_mode/->set_dma_mode does not.
   */
  
  int ide_set_xfer_rate(ide_drive_t *drive, u8 rate)
  {
  	ide_hwif_t *hwif = drive->hwif;
  	const struct ide_port_ops *port_ops = hwif->port_ops;
  
  	if (port_ops == NULL || port_ops->set_dma_mode == NULL ||
  	    (hwif->host_flags & IDE_HFLAG_NO_SET_MODE))
  		return -1;
  
  	rate = ide_rate_filter(drive, rate);
  
  	BUG_ON(rate < XFER_PIO_0);

  	if (rate >= XFER_PIO_0 && rate <= XFER_PIO_6)

  		return ide_set_pio_mode(drive, rate);
  
  	return ide_set_dma_mode(drive, rate);
  }