/*
   *	IDE tuning and bus mastering support for the CS5510/CS5520
   *	chipsets
   *
   *	The CS5510/CS5520 are slightly unusual devices. Unlike the 
   *	typical IDE controllers they do bus mastering with the drive in
   *	PIO mode and smarter silicon.
   *
   *	The practical upshot of this is that we must always tune the
   *	drive for the right PIO mode. We must also ignore all the blacklists
   *	and the drive bus mastering DMA information.
   *
   *	*** This driver is strictly experimental ***
   *
   *	(c) Copyright Red Hat Inc 2002
   * 
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License as published by the
   * Free Software Foundation; either version 2, or (at your option) any
   * later version.
   *
   * This program is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * General Public License for more details.
   *
   * For the avoidance of doubt the "preferred form" of this code is one which
   * is in an open non patent encumbered format. Where cryptographic key signing
   * forms part of the process of creating an executable the information
   * including keys needed to generate an equivalently functional executable
   * are deemed to be part of the source code.
   *
   */
   
  #include <linux/module.h>
  #include <linux/types.h>
  #include <linux/kernel.h>
  #include <linux/init.h>
  #include <linux/pci.h>
  #include <linux/ide.h>
  #include <linux/dma-mapping.h>
  
  #define DRV_NAME "cs5520"
  
  struct pio_clocks
  {
  	int address;
  	int assert;
  	int recovery;
  };
  
  static struct pio_clocks cs5520_pio_clocks[]={
  	{3, 6, 11},
  	{2, 5, 6},
  	{1, 4, 3},
  	{1, 3, 2},
  	{1, 2, 1}
  };
  
  static void cs5520_set_pio_mode(ide_hwif_t *hwif, ide_drive_t *drive)
  {
  	struct pci_dev *pdev = to_pci_dev(hwif->dev);
  	int controller = drive->dn > 1 ? 1 : 0;
  	const u8 pio = drive->pio_mode - XFER_PIO_0;
  
  	/* 8bit CAT/CRT - 8bit command timing for channel */
  	pci_write_config_byte(pdev, 0x62 + controller, 
  		(cs5520_pio_clocks[pio].recovery << 4) |
  		(cs5520_pio_clocks[pio].assert));
  
  	/* 0x64 - 16bit Primary, 0x68 - 16bit Secondary */
  
  	/* FIXME: should these use address ? */
  	/* Data read timing */
  	pci_write_config_byte(pdev, 0x64 + 4*controller + (drive->dn&1),
  		(cs5520_pio_clocks[pio].recovery << 4) |
  		(cs5520_pio_clocks[pio].assert));
  	/* Write command timing */
  	pci_write_config_byte(pdev, 0x66 + 4*controller + (drive->dn&1),
  		(cs5520_pio_clocks[pio].recovery << 4) |
  		(cs5520_pio_clocks[pio].assert));
  }
  
  static void cs5520_set_dma_mode(ide_hwif_t *hwif, ide_drive_t *drive)
  {
  	printk(KERN_ERR "cs55x0: bad ide timing.
  ");
  
  	drive->pio_mode = XFER_PIO_0 + 0;
  	cs5520_set_pio_mode(hwif, drive);
  }
  
  static const struct ide_port_ops cs5520_port_ops = {
  	.set_pio_mode		= cs5520_set_pio_mode,
  	.set_dma_mode		= cs5520_set_dma_mode,
  };
  
  static const struct ide_port_info cyrix_chipset = {
  	.name		= DRV_NAME,
  	.enablebits	= { { 0x60, 0x01, 0x01 }, { 0x60, 0x02, 0x02 } },
  	.port_ops	= &cs5520_port_ops,
  	.host_flags	= IDE_HFLAG_ISA_PORTS | IDE_HFLAG_CS5520,
  	.pio_mask	= ATA_PIO4,
  };
  
  /*
   *	The 5510/5520 are a bit weird. They don't quite set up the way
   *	the PCI helper layer expects so we must do much of the set up 
   *	work longhand.
   */
   
  static int cs5520_init_one(struct pci_dev *dev, const struct pci_device_id *id)
  {
  	const struct ide_port_info *d = &cyrix_chipset;
  	struct ide_hw hw[2], *hws[] = { NULL, NULL };
  
  	ide_setup_pci_noise(dev, d);
  
  	/* We must not grab the entire device, it has 'ISA' space in its
  	 * BARS too and we will freak out other bits of the kernel
  	 */
  	if (pci_enable_device_io(dev)) {
  		printk(KERN_WARNING "%s: Unable to enable 55x0.
  ", d->name);
  		return -ENODEV;
  	}
  	pci_set_master(dev);
  	if (pci_set_dma_mask(dev, DMA_BIT_MASK(32))) {
  		printk(KERN_WARNING "%s: No suitable DMA available.
  ",
  			d->name);
  		return -ENODEV;
  	}
  
  	/*
  	 *	Now the chipset is configured we can let the core
  	 *	do all the device setup for us
  	 */
  
  	ide_pci_setup_ports(dev, d, &hw[0], &hws[0]);
  	hw[0].irq = 14;
  	hw[1].irq = 15;
  
  	return ide_host_add(d, hws, 2, NULL);
  }
  
  static const struct pci_device_id cs5520_pci_tbl[] = {
  	{ PCI_VDEVICE(CYRIX, PCI_DEVICE_ID_CYRIX_5510), 0 },
  	{ PCI_VDEVICE(CYRIX, PCI_DEVICE_ID_CYRIX_5520), 1 },
  	{ 0, },
  };
  MODULE_DEVICE_TABLE(pci, cs5520_pci_tbl);
  
  static struct pci_driver cs5520_pci_driver = {
  	.name		= "Cyrix_IDE",
  	.id_table	= cs5520_pci_tbl,
  	.probe		= cs5520_init_one,
  	.suspend	= ide_pci_suspend,
  	.resume		= ide_pci_resume,
  };
  
  static int __init cs5520_ide_init(void)
  {
  	return ide_pci_register_driver(&cs5520_pci_driver);
  }
  
  module_init(cs5520_ide_init);
  
  MODULE_AUTHOR("Alan Cox");
  MODULE_DESCRIPTION("PCI driver module for Cyrix 5510/5520 IDE");
  MODULE_LICENSE("GPL");