/*
   * ixp4xx PATA/Compact Flash driver

   * Copyright (C) 2006-07 Tower Technologies

   * Author: Alessandro Zummo <a.zummo@towertech.it>
   *
   * An ATA driver to handle a Compact Flash connected
   * to the ixp4xx expansion bus in TrueIDE mode. The CF
   * must have it chip selects connected to two CS lines

   * on the ixp4xx. In the irq is not available, you might
   * want to modify both this driver and libata to run in
   * polling mode.

   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/libata.h>
  #include <linux/irq.h>
  #include <linux/platform_device.h>
  #include <scsi/scsi_host.h>
  
  #define DRV_NAME	"pata_ixp4xx_cf"

  #define DRV_VERSION	"0.2"

  static int ixp4xx_set_mode(struct ata_link *link, struct ata_device **error)

  {

  	struct ata_device *dev;

  	ata_for_each_dev(dev, link, ENABLED) {
  		ata_dev_printk(dev, KERN_INFO, "configured for PIO0
  ");
  		dev->pio_mode = XFER_PIO_0;
  		dev->xfer_mode = XFER_PIO_0;
  		dev->xfer_shift = ATA_SHIFT_PIO;
  		dev->flags |= ATA_DFLAG_PIO;

  	}

  	return 0;

  }

  static unsigned int ixp4xx_mmio_data_xfer(struct ata_device *dev,
  				unsigned char *buf, unsigned int buflen, int rw)

  {
  	unsigned int i;
  	unsigned int words = buflen >> 1;
  	u16 *buf16 = (u16 *) buf;

  	struct ata_port *ap = dev->link->ap;

  	void __iomem *mmio = ap->ioaddr.data_addr;

  	struct ixp4xx_pata_data *data = ap->host->dev->platform_data;
  
  	/* set the expansion bus in 16bit mode and restore
  	 * 8 bit mode after the transaction.
  	 */
  	*data->cs0_cfg &= ~(0x01);
  	udelay(100);
  
  	/* Transfer multiple of 2 bytes */

  	if (rw == READ)

  		for (i = 0; i < words; i++)
  			buf16[i] = readw(mmio);

  	else
  		for (i = 0; i < words; i++)
  			writew(buf16[i], mmio);

  
  	/* Transfer trailing 1 byte, if any. */
  	if (unlikely(buflen & 0x01)) {
  		u16 align_buf[1] = { 0 };
  		unsigned char *trailing_buf = buf + buflen - 1;

  		if (rw == READ) {

  			align_buf[0] = readw(mmio);
  			memcpy(trailing_buf, align_buf, 1);

  		} else {
  			memcpy(align_buf, trailing_buf, 1);
  			writew(align_buf[0], mmio);

  		}

  		words++;

  	}
  
  	udelay(100);
  	*data->cs0_cfg |= 0x01;

  
  	return words << 1;

  }

  static struct scsi_host_template ixp4xx_sht = {

  	ATA_PIO_SHT(DRV_NAME),

  };
  
  static struct ata_port_operations ixp4xx_port_ops = {

  	.inherits		= &ata_sff_port_ops,

  	.sff_data_xfer		= ixp4xx_mmio_data_xfer,

  	.cable_detect		= ata_cable_40wire,

  	.set_mode		= ixp4xx_set_mode,

  };

  static void ixp4xx_setup_port(struct ata_port *ap,

  			      struct ixp4xx_pata_data *data,
  			      unsigned long raw_cs0, unsigned long raw_cs1)

  {

  	struct ata_ioports *ioaddr = &ap->ioaddr;

  	unsigned long raw_cmd = raw_cs0;
  	unsigned long raw_ctl = raw_cs1 + 0x06;

  	ioaddr->cmd_addr	= data->cs0;
  	ioaddr->altstatus_addr	= data->cs1 + 0x06;
  	ioaddr->ctl_addr	= data->cs1 + 0x06;

  	ata_sff_std_ports(ioaddr);

  
  #ifndef __ARMEB__
  
  	/* adjust the addresses to handle the address swizzling of the
  	 * ixp4xx in little endian mode.
  	 */

  	*(unsigned long *)&ioaddr->data_addr		^= 0x02;
  	*(unsigned long *)&ioaddr->cmd_addr		^= 0x03;
  	*(unsigned long *)&ioaddr->altstatus_addr	^= 0x03;
  	*(unsigned long *)&ioaddr->ctl_addr		^= 0x03;
  	*(unsigned long *)&ioaddr->error_addr		^= 0x03;
  	*(unsigned long *)&ioaddr->feature_addr		^= 0x03;
  	*(unsigned long *)&ioaddr->nsect_addr		^= 0x03;
  	*(unsigned long *)&ioaddr->lbal_addr		^= 0x03;
  	*(unsigned long *)&ioaddr->lbam_addr		^= 0x03;
  	*(unsigned long *)&ioaddr->lbah_addr		^= 0x03;
  	*(unsigned long *)&ioaddr->device_addr		^= 0x03;
  	*(unsigned long *)&ioaddr->status_addr		^= 0x03;
  	*(unsigned long *)&ioaddr->command_addr		^= 0x03;

  
  	raw_cmd ^= 0x03;
  	raw_ctl ^= 0x03;

  #endif

  
  	ata_port_desc(ap, "cmd 0x%lx ctl 0x%lx", raw_cmd, raw_ctl);

  }
  
  static __devinit int ixp4xx_pata_probe(struct platform_device *pdev)
  {

  	unsigned int irq;
  	struct resource *cs0, *cs1;

  	struct ata_host *host;
  	struct ata_port *ap;

  	struct ixp4xx_pata_data *data = pdev->dev.platform_data;
  
  	cs0 = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	cs1 = platform_get_resource(pdev, IORESOURCE_MEM, 1);
  
  	if (!cs0 || !cs1)
  		return -EINVAL;

  	/* allocate host */
  	host = ata_host_alloc(&pdev->dev, 1);
  	if (!host)
  		return -ENOMEM;
  
  	/* acquire resources and fill host */

  	pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);

  	data->cs0 = devm_ioremap(&pdev->dev, cs0->start, 0x1000);
  	data->cs1 = devm_ioremap(&pdev->dev, cs1->start, 0x1000);

  	if (!data->cs0 || !data->cs1)
  		return -ENOMEM;

  	irq = platform_get_irq(pdev, 0);
  	if (irq)

  		set_irq_type(irq, IRQ_TYPE_EDGE_RISING);

  
  	/* Setup expansion bus chip selects */
  	*data->cs0_cfg = data->cs0_bits;
  	*data->cs1_cfg = data->cs1_bits;

  	ap = host->ports[0];

  	ap->ops	= &ixp4xx_port_ops;

  	ap->pio_mask = ATA_PIO4;

  	ap->flags |= ATA_FLAG_MMIO | ATA_FLAG_NO_LEGACY | ATA_FLAG_NO_ATAPI;

  	ixp4xx_setup_port(ap, data, cs0->start, cs1->start);

  
  	dev_printk(KERN_INFO, &pdev->dev, "version " DRV_VERSION "
  ");

  	/* activate host */

  	return ata_host_activate(host, irq, ata_sff_interrupt, 0, &ixp4xx_sht);

  }
  
  static __devexit int ixp4xx_pata_remove(struct platform_device *dev)
  {
  	struct ata_host *host = platform_get_drvdata(dev);

  	ata_host_detach(host);

  
  	return 0;
  }
  
  static struct platform_driver ixp4xx_pata_platform_driver = {
  	.driver	 = {
  		.name   = DRV_NAME,
  		.owner  = THIS_MODULE,
  	},
  	.probe		= ixp4xx_pata_probe,
  	.remove		= __devexit_p(ixp4xx_pata_remove),
  };
  
  static int __init ixp4xx_pata_init(void)
  {
  	return platform_driver_register(&ixp4xx_pata_platform_driver);
  }
  
  static void __exit ixp4xx_pata_exit(void)
  {
  	platform_driver_unregister(&ixp4xx_pata_platform_driver);
  }
  
  MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
  MODULE_DESCRIPTION("low-level driver for ixp4xx Compact Flash PATA");
  MODULE_LICENSE("GPL");
  MODULE_VERSION(DRV_VERSION);

  MODULE_ALIAS("platform:" DRV_NAME);

  
  module_init(ixp4xx_pata_init);
  module_exit(ixp4xx_pata_exit);