rz1000.c

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/*
 *  Copyright (C) 1995-1998  Linus Torvalds & author (see below)
 */

/*
 *  Principal Author:  [email protected] (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)\n", pci_name(dev));
        return 0;
    } else {
        printk(KERN_INFO "%s: serialized, disabled unmasking "
            "(buggy RZ1000/RZ1001)\n", pci_name(dev));
        return 1;
    }
}

static const struct ide_port_info rz1000_chipset __devinitconst = {
    .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");