#include <linux/kernel.h>
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/ide.h>

  #define DRV_NAME "ide-4drives"

  static bool probe_4drives;

  
  module_param_named(probe, probe_4drives, bool, 0);
  MODULE_PARM_DESC(probe, "probe for generic IDE chipset with 4 drives/port");

  static void ide_4drives_init_dev(ide_drive_t *drive)

  {

  	if (drive->hwif->channel)

  		drive->select ^= 0x20;

  }
  
  static const struct ide_port_ops ide_4drives_port_ops = {

  	.init_dev		= ide_4drives_init_dev,

  };
  
  static const struct ide_port_info ide_4drives_port_info = {
  	.port_ops		= &ide_4drives_port_ops,

  	.host_flags		= IDE_HFLAG_SERIALIZE | IDE_HFLAG_NO_DMA |
  				  IDE_HFLAG_4DRIVES,

  	.chipset		= ide_4drives,

  };

  static int __init ide_4drives_init(void)
  {

  	unsigned long base = 0x1f0, ctl = 0x3f6;

  	struct ide_hw hw, *hws[] = { &hw, &hw };

  
  	if (probe_4drives == 0)
  		return -ENODEV;

  	if (!request_region(base, 8, DRV_NAME)) {
  		printk(KERN_ERR "%s: I/O resource 0x%lX-0x%lX not free.
  ",
  				DRV_NAME, base, base + 7);
  		return -EBUSY;
  	}
  
  	if (!request_region(ctl, 1, DRV_NAME)) {
  		printk(KERN_ERR "%s: I/O resource 0x%lX not free.
  ",
  				DRV_NAME, ctl);
  		release_region(base, 8);
  		return -EBUSY;
  	}

  	memset(&hw, 0, sizeof(hw));

  	ide_std_init_ports(&hw, base, ctl);

  	hw.irq = 14;

  	return ide_host_add(&ide_4drives_port_info, hws, 2, NULL);

  }
  
  module_init(ide_4drives_init);
  
  MODULE_AUTHOR("Bartlomiej Zolnierkiewicz");
  MODULE_DESCRIPTION("generic IDE chipset with 4 drives/port support");
  MODULE_LICENSE("GPL");