/*
   *  Copyright (C) 1996  Linus Torvalds & author (see below)
   */
  
  #include <linux/module.h>
  #include <linux/types.h>
  #include <linux/kernel.h>
  #include <linux/delay.h>
  #include <linux/timer.h>
  #include <linux/mm.h>
  #include <linux/ioport.h>
  #include <linux/blkdev.h>
  #include <linux/ide.h>
  #include <linux/init.h>
  
  #include <asm/io.h>
  
  #define DRV_NAME "dtc2278"
  
  /*
   * Changing this #undef to #define may solve start up problems in some systems.
   */
  #undef ALWAYS_SET_DTC2278_PIO_MODE
  
  /*
   * From: andy@cercle.cts.com (Dyan Wile)
   *
   * Below is a patch for DTC-2278 - alike software-programmable controllers
   * The code enables the secondary IDE controller and the PIO4 (3?) timings on
   * the primary (EIDE). You may probably have to enable the 32-bit support to
   * get the full speed. You better get the disk interrupts disabled ( hdparm -u0
   * /dev/hd.. ) for the drives connected to the EIDE interface. (I get my
   * filesystem  corrupted with -u1, but under heavy disk load only :-)
   *
   * This card is now forced to use the "serialize" feature,
   * and irq-unmasking is disallowed.  If io_32bit is enabled,
   * it must be done for BOTH drives on each interface.
   *
   * This code was written for the DTC2278E, but might work with any of these:
   *
   * DTC2278S has only a single IDE interface.
   * DTC2278D has two IDE interfaces and is otherwise identical to the S version.
   * DTC2278E also has serial ports and a printer port
   * DTC2278EB: has onboard BIOS, and "works like a charm" -- Kent Bradford <kent@theory.caltech.edu>
   *
   * There may be a fourth controller type. The S and D versions use the
   * Winbond chip, and I think the E version does also.
   *
   */
  
  static void sub22 (char b, char c)
  {
  	int i;
  
  	for(i = 0; i < 3; ++i) {
  		inb(0x3f6);
  		outb_p(b,0xb0);
  		inb(0x3f6);
  		outb_p(c,0xb4);
  		inb(0x3f6);
  		if(inb(0xb4) == c) {
  			outb_p(7,0xb0);
  			inb(0x3f6);
  			return;	/* success */
  		}
  	}
  }
  
  static DEFINE_SPINLOCK(dtc2278_lock);
  
  static void dtc2278_set_pio_mode(ide_hwif_t *hwif, ide_drive_t *drive)
  {
  	unsigned long flags;
  
  	if (drive->pio_mode >= XFER_PIO_3) {
  		spin_lock_irqsave(&dtc2278_lock, flags);
  		/*
  		 * This enables PIO mode4 (3?) on the first interface
  		 */
  		sub22(1,0xc3);
  		sub22(0,0xa0);
  		spin_unlock_irqrestore(&dtc2278_lock, flags);
  	} else {
  		/* we don't know how to set it back again.. */
  		/* Actually we do - there is a data sheet available for the
  		   Winbond but does anyone actually care */
  	}
  }
  
  static const struct ide_port_ops dtc2278_port_ops = {
  	.set_pio_mode		= dtc2278_set_pio_mode,
  };
  
  static const struct ide_port_info dtc2278_port_info __initconst = {
  	.name			= DRV_NAME,
  	.chipset		= ide_dtc2278,
  	.port_ops		= &dtc2278_port_ops,
  	.host_flags		= IDE_HFLAG_SERIALIZE |
  				  IDE_HFLAG_NO_UNMASK_IRQS |
  				  IDE_HFLAG_IO_32BIT |
  				  /* disallow ->io_32bit changes */
  				  IDE_HFLAG_NO_IO_32BIT |
  				  IDE_HFLAG_NO_DMA |
  				  IDE_HFLAG_DTC2278,
  	.pio_mask		= ATA_PIO4,
  };
  
  static int __init dtc2278_probe(void)
  {
  	unsigned long flags;
  
  	local_irq_save(flags);
  	/*
  	 * This enables the second interface
  	 */
  	outb_p(4,0xb0);
  	inb(0x3f6);
  	outb_p(0x20,0xb4);
  	inb(0x3f6);
  #ifdef ALWAYS_SET_DTC2278_PIO_MODE
  	/*
  	 * This enables PIO mode4 (3?) on the first interface
  	 * and may solve start-up problems for some people.
  	 */
  	sub22(1,0xc3);
  	sub22(0,0xa0);
  #endif
  	local_irq_restore(flags);
  
  	return ide_legacy_device_add(&dtc2278_port_info, 0);
  }
  
  static bool probe_dtc2278;
  
  module_param_named(probe, probe_dtc2278, bool, 0);
  MODULE_PARM_DESC(probe, "probe for DTC2278xx chipsets");
  
  static int __init dtc2278_init(void)
  {
  	if (probe_dtc2278 == 0)
  		return -ENODEV;
  
  	if (dtc2278_probe()) {
  		printk(KERN_ERR "dtc2278: ide interfaces already in use!
  ");
  		return -EBUSY;
  	}
  	return 0;
  }
  
  module_init(dtc2278_init);
  
  MODULE_AUTHOR("See Local File");
  MODULE_DESCRIPTION("support of DTC-2278 VLB IDE chipsets");
  MODULE_LICENSE("GPL");