/*
   *  pata_sch.c - Intel SCH PATA controllers
   *
   *  Copyright (c) 2008 Alek Du <alek.du@intel.com>
   *
   *  This program is free software; you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License 2 as published
   *  by the Free Software Foundation.
   *
   *  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; see the file COPYING.  If not, write to
   *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
   *
   */
  
  /*
   *  Supports:
   *    Intel SCH (AF82US15W, AF82US15L, AF82UL11L) chipsets -- see spec at:
   *    http://download.intel.com/design/chipsets/embedded/datashts/319537.pdf
   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/pci.h>
  #include <linux/blkdev.h>
  #include <linux/delay.h>
  #include <linux/device.h>
  #include <scsi/scsi_host.h>
  #include <linux/libata.h>
  #include <linux/dmi.h>
  
  #define DRV_NAME	"pata_sch"
  #define DRV_VERSION	"0.2"
  
  /* see SCH datasheet page 351 */
  enum {
  	D0TIM	= 0x80,		/* Device 0 Timing Register */
  	D1TIM	= 0x84,		/* Device 1 Timing Register */
  	PM	= 0x07,		/* PIO Mode Bit Mask */
  	MDM	= (0x03 << 8),	/* Multi-word DMA Mode Bit Mask */
  	UDM	= (0x07 << 16), /* Ultra DMA Mode Bit Mask */
  	PPE	= (1 << 30),	/* Prefetch/Post Enable */
  	USD	= (1 << 31),	/* Use Synchronous DMA */
  };
  
  static int sch_init_one(struct pci_dev *pdev,
  			 const struct pci_device_id *ent);
  static void sch_set_piomode(struct ata_port *ap, struct ata_device *adev);
  static void sch_set_dmamode(struct ata_port *ap, struct ata_device *adev);
  
  static const struct pci_device_id sch_pci_tbl[] = {
  	/* Intel SCH PATA Controller */
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_SCH_IDE), 0 },
  	{ }	/* terminate list */
  };
  
  static struct pci_driver sch_pci_driver = {
  	.name			= DRV_NAME,
  	.id_table		= sch_pci_tbl,
  	.probe			= sch_init_one,
  	.remove			= ata_pci_remove_one,
  #ifdef CONFIG_PM_SLEEP
  	.suspend		= ata_pci_device_suspend,
  	.resume			= ata_pci_device_resume,
  #endif
  };
  
  static struct scsi_host_template sch_sht = {
  	ATA_BMDMA_SHT(DRV_NAME),
  };
  
  static struct ata_port_operations sch_pata_ops = {
  	.inherits		= &ata_bmdma_port_ops,
  	.cable_detect		= ata_cable_unknown,
  	.set_piomode		= sch_set_piomode,
  	.set_dmamode		= sch_set_dmamode,
  };
  
  static struct ata_port_info sch_port_info = {
  	.flags		= ATA_FLAG_SLAVE_POSS,
  	.pio_mask	= ATA_PIO4,
  	.mwdma_mask	= ATA_MWDMA2,
  	.udma_mask	= ATA_UDMA5,
  	.port_ops	= &sch_pata_ops,
  };
  
  MODULE_AUTHOR("Alek Du <alek.du@intel.com>");
  MODULE_DESCRIPTION("SCSI low-level driver for Intel SCH PATA controllers");
  MODULE_LICENSE("GPL");
  MODULE_DEVICE_TABLE(pci, sch_pci_tbl);
  MODULE_VERSION(DRV_VERSION);
  
  /**
   *	sch_set_piomode - Initialize host controller PATA PIO timings
   *	@ap: Port whose timings we are configuring
   *	@adev: ATA device
   *
   *	Set PIO mode for device, in host controller PCI config space.
   *
   *	LOCKING:
   *	None (inherited from caller).
   */
  
  static void sch_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 port	= adev->devno ? D1TIM : D0TIM;
  	unsigned int data;
  
  	pci_read_config_dword(dev, port, &data);
  	/* see SCH datasheet page 351 */
  	/* set PIO mode */
  	data &= ~(PM | PPE);
  	data |= pio;
  	/* enable PPE for block device */
  	if (adev->class == ATA_DEV_ATA)
  		data |= PPE;
  	pci_write_config_dword(dev, port, data);
  }
  
  /**
   *	sch_set_dmamode - Initialize host controller PATA DMA timings
   *	@ap: Port whose timings we are configuring
   *	@adev: ATA device
   *
   *	Set MW/UDMA mode for device, in host controller PCI config space.
   *
   *	LOCKING:
   *	None (inherited from caller).
   */
  
  static void sch_set_dmamode(struct ata_port *ap, struct ata_device *adev)
  {
  	unsigned int dma_mode	= adev->dma_mode;
  	struct pci_dev *dev	= to_pci_dev(ap->host->dev);
  	unsigned int port	= adev->devno ? D1TIM : D0TIM;
  	unsigned int data;
  
  	pci_read_config_dword(dev, port, &data);
  	/* see SCH datasheet page 351 */
  	if (dma_mode >= XFER_UDMA_0) {
  		/* enable Synchronous DMA mode */
  		data |= USD;
  		data &= ~UDM;
  		data |= (dma_mode - XFER_UDMA_0) << 16;
  	} else { /* must be MWDMA mode, since we masked SWDMA already */
  		data &= ~(USD | MDM);
  		data |= (dma_mode - XFER_MW_DMA_0) << 8;
  	}
  	pci_write_config_dword(dev, port, data);
  }
  
  /**
   *	sch_init_one - Register SCH ATA PCI device with kernel services
   *	@pdev: PCI device to register
   *	@ent: Entry in sch_pci_tbl matching with @pdev
   *
   *	LOCKING:
   *	Inherited from PCI layer (may sleep).
   *
   *	RETURNS:
   *	Zero on success, or -ERRNO value.
   */
  
  static int sch_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
  {
  	const struct ata_port_info *ppi[] = { &sch_port_info, NULL };
  
  	ata_print_version_once(&pdev->dev, DRV_VERSION);
  
  	return ata_pci_bmdma_init_one(pdev, ppi, &sch_sht, NULL, 0);
  }
  
  module_pci_driver(sch_pci_driver);