/*
   *    pata_oldpiix.c - Intel PATA/SATA controllers
   *

   *	(C) 2005 Red Hat

   *
   *    Some parts based on ata_piix.c by Jeff Garzik and others.
   *
   *    Early PIIX differs significantly from the later PIIX as it lacks
   *    SITRE and the slave timing registers. This means that you have to
   *    set timing per channel, or be clever. Libata tells us whenever it
   *    does drive selection and we use this to reload the timings.
   *
   *    Because of these behaviour differences PIIX gets its own driver module.
   */
  
  #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/ata.h>
  
  #define DRV_NAME	"pata_oldpiix"

  #define DRV_VERSION	"0.5.5"

  
  /**
   *	oldpiix_pre_reset		-	probe begin

   *	@link: ATA link

   *	@deadline: deadline jiffies for the operation

   *
   *	Set up cable type and use generic probe init
   */

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

  {

  	struct ata_port *ap = link->ap;

  	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
  	static const struct pci_bits oldpiix_enable_bits[] = {
  		{ 0x41U, 1U, 0x80UL, 0x80UL },	/* port 0 */
  		{ 0x43U, 1U, 0x80UL, 0x80UL },	/* port 1 */
  	};

  	if (!pci_test_config_bits(pdev, &oldpiix_enable_bits[ap->port_no]))
  		return -ENOENT;

  	return ata_sff_prereset(link, deadline);

  }
  
  /**

   *	oldpiix_set_piomode - Initialize host controller PATA PIO timings
   *	@ap: Port whose timings we are configuring

   *	@adev: Device whose timings we are configuring

   *
   *	Set PIO mode for device, in host controller PCI config space.
   *
   *	LOCKING:
   *	None (inherited from caller).
   */
  
  static void oldpiix_set_piomode (struct ata_port *ap, struct ata_device *adev)
  {
  	unsigned int pio	= adev->pio_mode - XFER_PIO_0;
  	struct pci_dev *dev	= to_pci_dev(ap->host->dev);
  	unsigned int idetm_port= ap->port_no ? 0x42 : 0x40;
  	u16 idetm_data;
  	int control = 0;
  
  	/*
  	 *	See Intel Document 298600-004 for the timing programing rules
  	 *	for PIIX/ICH. Note that the early PIIX does not have the slave
  	 *	timing port at 0x44.
  	 */
  
  	static const	 /* ISP  RTC */
  	u8 timings[][2]	= { { 0, 0 },
  			    { 0, 0 },
  			    { 1, 0 },
  			    { 2, 1 },
  			    { 2, 3 }, };

  	if (pio > 1)
  		control |= 1;	/* TIME */

  	if (ata_pio_need_iordy(adev))

  		control |= 2;	/* IE */

  	/* Intel specifies that the prefetch/posting is for disk only */

  	if (adev->class == ATA_DEV_ATA)

  		control |= 4;	/* PPE */

  
  	pci_read_config_word(dev, idetm_port, &idetm_data);

  	/*
  	 * Set PPE, IE and TIME as appropriate.
  	 * Clear the other drive's timing bits.
  	 */

  	if (adev->devno == 0) {
  		idetm_data &= 0xCCE0;
  		idetm_data |= control;
  	} else {
  		idetm_data &= 0xCC0E;
  		idetm_data |= (control << 4);
  	}
  	idetm_data |= (timings[pio][0] << 12) |
  			(timings[pio][1] << 8);
  	pci_write_config_word(dev, idetm_port, idetm_data);
  
  	/* Track which port is configured */
  	ap->private_data = adev;
  }
  
  /**
   *	oldpiix_set_dmamode - Initialize host controller PATA DMA timings
   *	@ap: Port whose timings we are configuring
   *	@adev: Device to program

   *
   *	Set MWDMA mode for device, in host controller PCI config space.
   *
   *	LOCKING:
   *	None (inherited from caller).
   */
  
  static void oldpiix_set_dmamode (struct ata_port *ap, struct ata_device *adev)
  {
  	struct pci_dev *dev	= to_pci_dev(ap->host->dev);
  	u8 idetm_port		= ap->port_no ? 0x42 : 0x40;
  	u16 idetm_data;
  
  	static const	 /* ISP  RTC */
  	u8 timings[][2]	= { { 0, 0 },
  			    { 0, 0 },
  			    { 1, 0 },
  			    { 2, 1 },
  			    { 2, 3 }, };
  
  	/*
  	 * MWDMA is driven by the PIO timings. We must also enable
  	 * IORDY unconditionally along with TIME1. PPE has already
  	 * been set when the PIO timing was set.
  	 */
  
  	unsigned int mwdma	= adev->dma_mode - XFER_MW_DMA_0;
  	unsigned int control;
  	const unsigned int needed_pio[3] = {
  		XFER_PIO_0, XFER_PIO_3, XFER_PIO_4
  	};
  	int pio = needed_pio[mwdma] - XFER_PIO_0;
  
  	pci_read_config_word(dev, idetm_port, &idetm_data);
  
  	control = 3;	/* IORDY|TIME0 */
  	/* Intel specifies that the PPE functionality is for disk only */
  	if (adev->class == ATA_DEV_ATA)
  		control |= 4;	/* PPE enable */
  
  	/* If the drive MWDMA is faster than it can do PIO then
  	   we must force PIO into PIO0 */
  
  	if (adev->pio_mode < needed_pio[mwdma])
  		/* Enable DMA timing only */
  		control |= 8;	/* PIO cycles in PIO0 */
  
  	/* Mask out the relevant control and timing bits we will load. Also
  	   clear the other drive TIME register as a precaution */
  	if (adev->devno == 0) {
  		idetm_data &= 0xCCE0;
  		idetm_data |= control;
  	} else {
  		idetm_data &= 0xCC0E;
  		idetm_data |= (control << 4);
  	}
  	idetm_data |= (timings[pio][0] << 12) | (timings[pio][1] << 8);
  	pci_write_config_word(dev, idetm_port, idetm_data);
  
  	/* Track which port is configured */
  	ap->private_data = adev;
  }
  
  /**

   *	oldpiix_qc_issue	-	command issue

   *	@qc: command pending
   *
   *	Called when the libata layer is about to issue a command. We wrap
   *	this interface so that we can load the correct ATA timings if

   *	necessary. Our logic also clears TIME0/TIME1 for the other device so

   *	that, even if we get this wrong, cycles to the other device will
   *	be made PIO0.
   */

  static unsigned int oldpiix_qc_issue(struct ata_queued_cmd *qc)

  {
  	struct ata_port *ap = qc->ap;
  	struct ata_device *adev = qc->dev;
  
  	if (adev != ap->private_data) {

  		oldpiix_set_piomode(ap, adev);

  		if (ata_dma_enabled(adev))

  			oldpiix_set_dmamode(ap, adev);

  	}

  	return ata_bmdma_qc_issue(qc);

  }
  
  
  static struct scsi_host_template oldpiix_sht = {

  	ATA_BMDMA_SHT(DRV_NAME),

  };

  static struct ata_port_operations oldpiix_pata_ops = {
  	.inherits		= &ata_bmdma_port_ops,

  	.qc_issue		= oldpiix_qc_issue,

  	.cable_detect		= ata_cable_40wire,

  	.set_piomode		= oldpiix_set_piomode,
  	.set_dmamode		= oldpiix_set_dmamode,

  	.prereset		= oldpiix_pre_reset,

  };
  
  
  /**
   *	oldpiix_init_one - Register PIIX ATA PCI device with kernel services
   *	@pdev: PCI device to register
   *	@ent: Entry in oldpiix_pci_tbl matching with @pdev
   *
   *	Called from kernel PCI layer.  We probe for combined mode (sigh),
   *	and then hand over control to libata, for it to do the rest.
   *
   *	LOCKING:
   *	Inherited from PCI layer (may sleep).
   *
   *	RETURNS:
   *	Zero on success, or -ERRNO value.
   */
  
  static int oldpiix_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
  {

  	static const struct ata_port_info info = {

  		.flags		= ATA_FLAG_SLAVE_POSS,

  		.pio_mask	= ATA_PIO4,

  		.mwdma_mask	= ATA_MWDMA12_ONLY,

  		.port_ops	= &oldpiix_pata_ops,
  	};

  	const struct ata_port_info *ppi[] = { &info, NULL };

  	ata_print_version_once(&pdev->dev, DRV_VERSION);

  	return ata_pci_bmdma_init_one(pdev, ppi, &oldpiix_sht, NULL, 0);

  }
  
  static const struct pci_device_id oldpiix_pci_tbl[] = {

  	{ PCI_VDEVICE(INTEL, 0x1230), },

  	{ }	/* terminate list */
  };
  
  static struct pci_driver oldpiix_pci_driver = {
  	.name			= DRV_NAME,
  	.id_table		= oldpiix_pci_tbl,
  	.probe			= oldpiix_init_one,
  	.remove			= ata_pci_remove_one,

  #ifdef CONFIG_PM

  	.suspend		= ata_pci_device_suspend,
  	.resume			= ata_pci_device_resume,

  #endif

  };
  
  static int __init oldpiix_init(void)
  {
  	return pci_register_driver(&oldpiix_pci_driver);
  }
  
  static void __exit oldpiix_exit(void)
  {
  	pci_unregister_driver(&oldpiix_pci_driver);
  }

  module_init(oldpiix_init);
  module_exit(oldpiix_exit);
  
  MODULE_AUTHOR("Alan Cox");
  MODULE_DESCRIPTION("SCSI low-level driver for early PIIX series controllers");
  MODULE_LICENSE("GPL");
  MODULE_DEVICE_TABLE(pci, oldpiix_pci_tbl);
  MODULE_VERSION(DRV_VERSION);