/*

   *  Copyright (C) 1995-1998  Linus Torvalds & author (see below)
   */
  
  /*
   *  Principal Author:  mlord@pobox.com (Mark Lord)
   *
   *  See linux/MAINTAINERS for address of current maintainer.
   *
   *  This file provides support for disabling the buggy read-ahead
   *  mode of the RZ1000 IDE chipset, commonly used on Intel motherboards.
   *
   *  Dunno if this fixes both ports, or only the primary port (?).
   */

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

  #include <linux/pci.h>
  #include <linux/ide.h>
  #include <linux/init.h>

  #define DRV_NAME "rz1000"

  static int __devinit rz1000_disable_readahead(struct pci_dev *dev)

  {
  	u16 reg;

  	if (!pci_read_config_word (dev, 0x40, &reg) &&
  	    !pci_write_config_word(dev, 0x40, reg & 0xdfff)) {
  		printk(KERN_INFO "%s: disabled chipset read-ahead "

  			"(buggy RZ1000/RZ1001)
  ", pci_name(dev));
  		return 0;

  	} else {

  		printk(KERN_INFO "%s: serialized, disabled unmasking "

  			"(buggy RZ1000/RZ1001)
  ", pci_name(dev));
  		return 1;

  	}
  }

  static const struct ide_port_info rz1000_chipset __devinitdata = {

  	.name		= DRV_NAME,

  	.host_flags	= IDE_HFLAG_NO_DMA,

  };
  
  static int __devinit rz1000_init_one(struct pci_dev *dev, const struct pci_device_id *id)
  {

  	struct ide_port_info d = rz1000_chipset;
  	int rc;
  
  	rc = pci_enable_device(dev);
  	if (rc)
  		return rc;
  
  	if (rz1000_disable_readahead(dev)) {
  		d.host_flags |= IDE_HFLAG_SERIALIZE;
  		d.host_flags |= IDE_HFLAG_NO_UNMASK_IRQS;
  	}
  
  	return ide_pci_init_one(dev, &d, NULL);
  }
  
  static void rz1000_remove(struct pci_dev *dev)
  {
  	ide_pci_remove(dev);
  	pci_disable_device(dev);

  }

  static const struct pci_device_id rz1000_pci_tbl[] = {
  	{ PCI_VDEVICE(PCTECH, PCI_DEVICE_ID_PCTECH_RZ1000), 0 },
  	{ PCI_VDEVICE(PCTECH, PCI_DEVICE_ID_PCTECH_RZ1001), 0 },

  	{ 0, },
  };
  MODULE_DEVICE_TABLE(pci, rz1000_pci_tbl);

  static struct pci_driver rz1000_pci_driver = {

  	.name		= "RZ1000_IDE",
  	.id_table	= rz1000_pci_tbl,
  	.probe		= rz1000_init_one,

  	.remove		= rz1000_remove,

  };

  static int __init rz1000_ide_init(void)

  {

  	return ide_pci_register_driver(&rz1000_pci_driver);

  }

  static void __exit rz1000_ide_exit(void)
  {

  	pci_unregister_driver(&rz1000_pci_driver);

  }

  module_init(rz1000_ide_init);

  module_exit(rz1000_ide_exit);

  
  MODULE_AUTHOR("Andre Hedrick");
  MODULE_DESCRIPTION("PCI driver module for RZ1000 IDE");
  MODULE_LICENSE("GPL");