/*
   *	ACPI PATA driver
   *

   *	(c) 2007 Red Hat

   */
  
  #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 <linux/gfp.h>

  #include <scsi/scsi_host.h>
  #include <acpi/acpi_bus.h>

  
  #include <linux/libata.h>
  #include <linux/ata.h>
  
  #define DRV_NAME	"pata_acpi"
  #define DRV_VERSION	"0.2.3"
  
  struct pata_acpi {
  	struct ata_acpi_gtm gtm;
  	void *last;
  	unsigned long mask[2];
  };
  
  /**
   *	pacpi_pre_reset	-	check for 40/80 pin
   *	@ap: Port
   *	@deadline: deadline jiffies for the operation
   *
   *	Perform the PATA port setup we need.
   */
  
  static int pacpi_pre_reset(struct ata_link *link, unsigned long deadline)
  {
  	struct ata_port *ap = link->ap;
  	struct pata_acpi *acpi = ap->private_data;
  	if (ap->acpi_handle == NULL || ata_acpi_gtm(ap, &acpi->gtm) < 0)
  		return -ENODEV;

  	return ata_sff_prereset(link, deadline);

  }
  
  /**
   *	pacpi_cable_detect	-	cable type detection
   *	@ap: port to detect
   *
   *	Perform device specific cable detection
   */
  
  static int pacpi_cable_detect(struct ata_port *ap)
  {
  	struct pata_acpi *acpi = ap->private_data;
  
  	if ((acpi->mask[0] | acpi->mask[1]) & (0xF8 << ATA_SHIFT_UDMA))
  		return ATA_CBL_PATA80;
  	else
  		return ATA_CBL_PATA40;
  }
  
  /**

   *	pacpi_discover_modes	-	filter non ACPI modes
   *	@adev: ATA device
   *	@mask: proposed modes
   *
   *	Try the modes available and see which ones the ACPI method will
   *	set up sensibly. From this we get a mask of ACPI modes we can use
   */
  
  static unsigned long pacpi_discover_modes(struct ata_port *ap, struct ata_device *adev)
  {

  	struct pata_acpi *acpi = ap->private_data;

  	struct ata_acpi_gtm probe;

  	unsigned int xfer_mask;

  
  	probe = acpi->gtm;

  	ata_acpi_gtm(ap, &probe);

  	xfer_mask = ata_acpi_gtm_xfermask(adev, &probe);

  	if (xfer_mask & (0xF8 << ATA_SHIFT_UDMA))

  		ap->cbl = ATA_CBL_PATA80;

  
  	return xfer_mask;

  }
  
  /**
   *	pacpi_mode_filter	-	mode filter for ACPI
   *	@adev: device
   *	@mask: mask of valid modes
   *
   *	Filter the valid mode list according to our own specific rules, in
   *	this case the list of discovered valid modes obtained by ACPI probing
   */
  
  static unsigned long pacpi_mode_filter(struct ata_device *adev, unsigned long mask)
  {
  	struct pata_acpi *acpi = adev->link->ap->private_data;

  	return mask & acpi->mask[adev->devno];

  }
  
  /**
   *	pacpi_set_piomode	-	set initial PIO mode data
   *	@ap: ATA interface
   *	@adev: ATA device
   */
  
  static void pacpi_set_piomode(struct ata_port *ap, struct ata_device *adev)
  {
  	int unit = adev->devno;
  	struct pata_acpi *acpi = ap->private_data;

  	const struct ata_timing *t;

  	if (!(acpi->gtm.flags & 0x10))

  		unit = 0;
  
  	/* Now stuff the nS values into the structure */

  	t = ata_timing_find_mode(adev->pio_mode);
  	acpi->gtm.drive[unit].pio = t->cycle;

  	ata_acpi_stm(ap, &acpi->gtm);
  	/* See what mode we actually got */
  	ata_acpi_gtm(ap, &acpi->gtm);
  }
  
  /**
   *	pacpi_set_dmamode	-	set initial DMA mode data
   *	@ap: ATA interface
   *	@adev: ATA device
   */
  
  static void pacpi_set_dmamode(struct ata_port *ap, struct ata_device *adev)
  {
  	int unit = adev->devno;
  	struct pata_acpi *acpi = ap->private_data;

  	const struct ata_timing *t;

  	if (!(acpi->gtm.flags & 0x10))

  		unit = 0;
  
  	/* Now stuff the nS values into the structure */

  	t = ata_timing_find_mode(adev->dma_mode);

  	if (adev->dma_mode >= XFER_UDMA_0) {

  		acpi->gtm.drive[unit].dma = t->udma;

  		acpi->gtm.flags |= (1 << (2 * unit));
  	} else {

  		acpi->gtm.drive[unit].dma = t->cycle;

  		acpi->gtm.flags &= ~(1 << (2 * unit));
  	}
  	ata_acpi_stm(ap, &acpi->gtm);
  	/* See what mode we actually got */
  	ata_acpi_gtm(ap, &acpi->gtm);
  }
  
  /**

   *	pacpi_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.

   */

  static unsigned int pacpi_qc_issue(struct ata_queued_cmd *qc)

  {
  	struct ata_port *ap = qc->ap;
  	struct ata_device *adev = qc->dev;
  	struct pata_acpi *acpi = ap->private_data;
  
  	if (acpi->gtm.flags & 0x10)

  		return ata_bmdma_qc_issue(qc);

  
  	if (adev != acpi->last) {
  		pacpi_set_piomode(ap, adev);

  		if (ata_dma_enabled(adev))

  			pacpi_set_dmamode(ap, adev);
  		acpi->last = adev;
  	}

  	return ata_bmdma_qc_issue(qc);

  }
  
  /**
   *	pacpi_port_start	-	port setup
   *	@ap: ATA port being set up
   *
   *	Use the port_start hook to maintain private control structures
   */
  
  static int pacpi_port_start(struct ata_port *ap)
  {
  	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
  	struct pata_acpi *acpi;

  	if (ap->acpi_handle == NULL)
  		return -ENODEV;
  
  	acpi = ap->private_data = devm_kzalloc(&pdev->dev, sizeof(struct pata_acpi), GFP_KERNEL);
  	if (ap->private_data == NULL)
  		return -ENOMEM;
  	acpi->mask[0] = pacpi_discover_modes(ap, &ap->link.device[0]);
  	acpi->mask[1] = pacpi_discover_modes(ap, &ap->link.device[1]);

  	return ata_bmdma_port_start(ap);

  }
  
  static struct scsi_host_template pacpi_sht = {

  	ATA_BMDMA_SHT(DRV_NAME),

  };

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

  	.qc_issue		= pacpi_qc_issue,

  	.cable_detect		= pacpi_cable_detect,
  	.mode_filter		= pacpi_mode_filter,

  	.set_piomode		= pacpi_set_piomode,
  	.set_dmamode		= pacpi_set_dmamode,

  	.prereset		= pacpi_pre_reset,

  	.port_start		= pacpi_port_start,
  };
  
  
  /**
   *	pacpi_init_one - Register ACPI ATA PCI device with kernel services
   *	@pdev: PCI device to register
   *	@ent: Entry in pacpi_pci_tbl matching with @pdev
   *
   *	Called from kernel PCI layer.
   *
   *	LOCKING:
   *	Inherited from PCI layer (may sleep).
   *
   *	RETURNS:
   *	Zero on success, or -ERRNO value.
   */
  
  static int pacpi_init_one (struct pci_dev *pdev, const struct pci_device_id *id)
  {
  	static const struct ata_port_info info = {

  		.flags		= ATA_FLAG_SLAVE_POSS,

  		.pio_mask	= ATA_PIO4,
  		.mwdma_mask	= ATA_MWDMA2,
  		.udma_mask 	= ATA_UDMA6,

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

  	if (pdev->vendor == PCI_VENDOR_ID_ATI) {
  		int rc = pcim_enable_device(pdev);
  		if (rc < 0)
  			return rc;
  		pcim_pin_device(pdev);
  	}

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

  }
  
  static const struct pci_device_id pacpi_pci_tbl[] = {
  	{ PCI_ANY_ID,		PCI_ANY_ID,			   PCI_ANY_ID, PCI_ANY_ID, PCI_CLASS_STORAGE_IDE << 8, 0xFFFFFF00UL, 1},
  	{ }	/* terminate list */
  };
  
  static struct pci_driver pacpi_pci_driver = {
  	.name			= DRV_NAME,
  	.id_table		= pacpi_pci_tbl,
  	.probe			= pacpi_init_one,
  	.remove			= ata_pci_remove_one,

  #ifdef CONFIG_PM

  	.suspend		= ata_pci_device_suspend,
  	.resume			= ata_pci_device_resume,

  #endif

  };
  
  static int __init pacpi_init(void)
  {
  	return pci_register_driver(&pacpi_pci_driver);
  }
  
  static void __exit pacpi_exit(void)
  {
  	pci_unregister_driver(&pacpi_pci_driver);
  }
  
  module_init(pacpi_init);
  module_exit(pacpi_exit);
  
  MODULE_AUTHOR("Alan Cox");
  MODULE_DESCRIPTION("SCSI low-level driver for ATA in ACPI mode");
  MODULE_LICENSE("GPL");
  MODULE_DEVICE_TABLE(pci, pacpi_pci_tbl);
  MODULE_VERSION(DRV_VERSION);