drivers/ide/rz1000.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  Copyright (C) 1995-1998  Linus Torvalds & author (see below)
   4  */
   5
   6 /*
   7  *  Principal Author:  mlord@pobox.com (Mark Lord)
   8  *
   9  *  See linux/MAINTAINERS for address of current maintainer.
  10  *
  11  *  This file provides support for disabling the buggy read-ahead
  12  *  mode of the RZ1000 IDE chipset, commonly used on Intel motherboards.
  13  *
  14  *  Dunno if this fixes both ports, or only the primary port (?).
  15  */
  16
  17 #include <linux/types.h>
  18 #include <linux/module.h>
  19 #include <linux/kernel.h>
  20 #include <linux/pci.h>
  21 #include <linux/ide.h>
  22 #include <linux/init.h>
  23
  24 #define DRV_NAME "rz1000"
  25
  26 static int rz1000_disable_readahead(struct pci_dev *dev)
  27 {
  28         u16 reg;
  29
  30         if (!pci_read_config_word (dev, 0x40, &reg) &&
  31             !pci_write_config_word(dev, 0x40, reg & 0xdfff)) {
  32                 printk(KERN_INFO "%s: disabled chipset read-ahead "
  33                         "(buggy RZ1000/RZ1001)\n", pci_name(dev));
  34                 return 0;
  35         } else {
  36                 printk(KERN_INFO "%s: serialized, disabled unmasking "
  37                         "(buggy RZ1000/RZ1001)\n", pci_name(dev));
  38                 return 1;
  39         }
  40 }
  41
  42 static const struct ide_port_info rz1000_chipset = {
  43         .name           = DRV_NAME,
  44         .host_flags     = IDE_HFLAG_NO_DMA,
  45 };
  46
  47 static int rz1000_init_one(struct pci_dev *dev, const struct pci_device_id *id)
  48 {
  49         struct ide_port_info d = rz1000_chipset;
  50         int rc;
  51
  52         rc = pci_enable_device(dev);
  53         if (rc)
  54                 return rc;
  55
  56         if (rz1000_disable_readahead(dev)) {
  57                 d.host_flags |= IDE_HFLAG_SERIALIZE;
  58                 d.host_flags |= IDE_HFLAG_NO_UNMASK_IRQS;
  59         }
  60
  61         return ide_pci_init_one(dev, &d, NULL);
  62 }
  63
  64 static void rz1000_remove(struct pci_dev *dev)
  65 {
  66         ide_pci_remove(dev);
  67         pci_disable_device(dev);
  68 }
  69
  70 static const struct pci_device_id rz1000_pci_tbl[] = {
  71         { PCI_VDEVICE(PCTECH, PCI_DEVICE_ID_PCTECH_RZ1000), 0 },
  72         { PCI_VDEVICE(PCTECH, PCI_DEVICE_ID_PCTECH_RZ1001), 0 },
  73         { 0, },
  74 };
  75 MODULE_DEVICE_TABLE(pci, rz1000_pci_tbl);
  76
  77 static struct pci_driver rz1000_pci_driver = {
  78         .name           = "RZ1000_IDE",
  79         .id_table       = rz1000_pci_tbl,
  80         .probe          = rz1000_init_one,
  81         .remove         = rz1000_remove,
  82 };
  83
  84 static int __init rz1000_ide_init(void)
  85 {
  86         return ide_pci_register_driver(&rz1000_pci_driver);
  87 }
  88
  89 static void __exit rz1000_ide_exit(void)
  90 {
  91         pci_unregister_driver(&rz1000_pci_driver);
  92 }
  93
  94 module_init(rz1000_ide_init);
  95 module_exit(rz1000_ide_exit);
  96
  97 MODULE_AUTHOR("Andre Hedrick");
  98 MODULE_DESCRIPTION("PCI driver module for RZ1000 IDE");
  99 MODULE_LICENSE("GPL");
 100