/*
   * pata_triflex.c 	- Compaq PATA for new ATA layer
   *			  (C) 2005 Red Hat Inc

   *			  Alan Cox <alan@lxorguk.ukuu.org.uk>

   *
   * based upon
   *
   * triflex.c
   *
   * IDE Chipset driver for the Compaq TriFlex IDE controller.
   *
   * Known to work with the Compaq Workstation 5x00 series.
   *
   * Copyright (C) 2002 Hewlett-Packard Development Group, L.P.
   * Author: Torben Mathiasen <torben.mathiasen@hp.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 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; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   *
   * Loosely based on the piix & svwks drivers.
   *
   * Documentation:

   *	Not publicly available.

   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/pci.h>

  #include <linux/blkdev.h>
  #include <linux/delay.h>
  #include <scsi/scsi_host.h>
  #include <linux/libata.h>
  
  #define DRV_NAME "pata_triflex"

  #define DRV_VERSION "0.2.8"

  
  /**

   *	triflex_prereset		-	probe begin

   *	@link: ATA link

   *	@deadline: deadline jiffies for the operation

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

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

  {
  	static const struct pci_bits triflex_enable_bits[] = {
  		{ 0x80, 1, 0x01, 0x01 },
  		{ 0x80, 1, 0x02, 0x02 }
  	};

  	struct ata_port *ap = link->ap;

  	struct pci_dev *pdev = to_pci_dev(ap->host->dev);

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

  	return ata_sff_prereset(link, deadline);

  }

  /**
   *	triflex_load_timing		-	timing configuration
   *	@ap: ATA interface
   *	@adev: Device on the bus
   *	@speed: speed to configure
   *
   *	The Triflex has one set of timings per device per channel. This
   *	means we must do some switching. As the PIO and DMA timings don't
   *	match we have to do some reloading unlike PIIX devices where tuning
   *	tricks can avoid it.
   */
  
  static void triflex_load_timing(struct ata_port *ap, struct ata_device *adev, int speed)
  {
  	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
  	u32 timing = 0;
  	u32 triflex_timing, old_triflex_timing;
  	int channel_offset = ap->port_no ? 0x74: 0x70;
  	unsigned int is_slave	= (adev->devno != 0);
  
  
  	pci_read_config_dword(pdev, channel_offset, &old_triflex_timing);
  	triflex_timing = old_triflex_timing;
  
  	switch(speed)
  	{
  		case XFER_MW_DMA_2:
  			timing = 0x0103;break;
  		case XFER_MW_DMA_1:
  			timing = 0x0203;break;
  		case XFER_MW_DMA_0:
  			timing = 0x0808;break;
  		case XFER_SW_DMA_2:
  		case XFER_SW_DMA_1:
  		case XFER_SW_DMA_0:
  			timing = 0x0F0F;break;
  		case XFER_PIO_4:
  			timing = 0x0202;break;
  		case XFER_PIO_3:
  			timing = 0x0204;break;
  		case XFER_PIO_2:
  			timing = 0x0404;break;
  		case XFER_PIO_1:
  			timing = 0x0508;break;
  		case XFER_PIO_0:
  			timing = 0x0808;break;
  		default:
  			BUG();
  	}
  	triflex_timing &= ~ (0xFFFF << (16 * is_slave));
  	triflex_timing |= (timing << (16 * is_slave));
  
  	if (triflex_timing != old_triflex_timing)
  		pci_write_config_dword(pdev, channel_offset, triflex_timing);
  }
  
  /**
   *	triflex_set_piomode	-	set initial PIO mode data
   *	@ap: ATA interface
   *	@adev: ATA device
   *
   *	Use the timing loader to set up the PIO mode. We have to do this
   *	because DMA start/stop will only be called once DMA occurs. If there
   *	has been no DMA then the PIO timings are still needed.
   */
  static void triflex_set_piomode(struct ata_port *ap, struct ata_device *adev)
  {
  	triflex_load_timing(ap, adev, adev->pio_mode);
  }
  
  /**
   *	triflex_dma_start	-	DMA start callback
   *	@qc: Command in progress
   *
   *	Usually drivers set the DMA timing at the point the set_dmamode call
   *	is made. Triflex however requires we load new timings on the
   *	transition or keep matching PIO/DMA pairs (ie MWDMA2/PIO4 etc).
   *	We load the DMA timings just before starting DMA and then restore
   *	the PIO timing when the DMA is finished.
   */
  
  static void triflex_bmdma_start(struct ata_queued_cmd *qc)
  {
  	triflex_load_timing(qc->ap, qc->dev, qc->dev->dma_mode);
  	ata_bmdma_start(qc);
  }
  
  /**
   *	triflex_dma_stop	-	DMA stop callback
   *	@ap: ATA interface
   *	@adev: ATA device
   *
   *	We loaded new timings in dma_start, as a result we need to restore
   *	the PIO timings in dma_stop so that the next command issue gets the
   *	right clock values.
   */
  
  static void triflex_bmdma_stop(struct ata_queued_cmd *qc)
  {
  	ata_bmdma_stop(qc);
  	triflex_load_timing(qc->ap, qc->dev, qc->dev->pio_mode);
  }
  
  static struct scsi_host_template triflex_sht = {

  	ATA_BMDMA_SHT(DRV_NAME),

  };
  
  static struct ata_port_operations triflex_port_ops = {

  	.inherits	= &ata_bmdma_port_ops,

  	.bmdma_start 	= triflex_bmdma_start,
  	.bmdma_stop	= triflex_bmdma_stop,

  	.cable_detect	= ata_cable_40wire,
  	.set_piomode	= triflex_set_piomode,

  	.prereset	= triflex_prereset,

  };
  
  static int triflex_init_one(struct pci_dev *dev, 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,

  		.port_ops = &triflex_port_ops
  	};

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

  	ata_print_version_once(&dev->dev, DRV_VERSION);

  	return ata_pci_bmdma_init_one(dev, ppi, &triflex_sht, NULL, 0);

  }
  
  static const struct pci_device_id triflex[] = {

  	{ PCI_VDEVICE(COMPAQ, PCI_DEVICE_ID_COMPAQ_TRIFLEX_IDE), },
  
  	{ },

  };

  #ifdef CONFIG_PM_SLEEP

  static int triflex_ata_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg)
  {

  	struct ata_host *host = pci_get_drvdata(pdev);

  	int rc = 0;
  
  	rc = ata_host_suspend(host, mesg);
  	if (rc)
  		return rc;
  
  	/*
  	 * We must not disable or powerdown the device.
  	 * APM bios refuses to suspend if IDE is not accessible.
  	 */
  	pci_save_state(pdev);
  
  	return 0;
  }
  
  #endif

  static struct pci_driver triflex_pci_driver = {

  	.name 		= DRV_NAME,

  	.id_table	= triflex,
  	.probe 		= triflex_init_one,

  	.remove		= ata_pci_remove_one,

  #ifdef CONFIG_PM_SLEEP

  	.suspend	= triflex_ata_pci_device_suspend,

  	.resume		= ata_pci_device_resume,

  #endif

  };

  module_pci_driver(triflex_pci_driver);

  MODULE_AUTHOR("Alan Cox");
  MODULE_DESCRIPTION("low-level driver for Compaq Triflex");
  MODULE_LICENSE("GPL");
  MODULE_DEVICE_TABLE(pci, triflex);
  MODULE_VERSION(DRV_VERSION);