/*
   *  A low-level PATA driver to handle a Compact Flash connected on the
   *  Mikrotik's RouterBoard 532 board.
   *
   *  Copyright (C) 2007 Gabor Juhos <juhosg at openwrt.org>
   *  Copyright (C) 2008 Florian Fainelli <florian@openwrt.org>
   *
   *  This file was based on: drivers/ata/pata_ixp4xx_cf.c
   *	Copyright (C) 2006-07 Tower Technologies
   *	Author: Alessandro Zummo <a.zummo@towertech.it>
   *
   *  Also was based on the driver for Linux 2.4.xx published by Mikrotik for
   *  their RouterBoard 1xx and 5xx series devices. The original Mikrotik code
   *  seems not to have a license.
   *
   *  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/gfp.h>

  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/platform_device.h>
  
  #include <linux/io.h>
  #include <linux/interrupt.h>
  #include <linux/irq.h>
  
  #include <linux/libata.h>
  #include <scsi/scsi_host.h>
  
  #include <asm/gpio.h>

  #define DRV_NAME	"pata-rb532-cf"

  #define DRV_VERSION	"0.1.0"
  #define DRV_DESC	"PATA driver for RouterBOARD 532 Compact Flash"
  
  #define RB500_CF_MAXPORTS	1
  #define RB500_CF_IO_DELAY	400

  #define RB500_CF_REG_BASE	0x0800
  #define RB500_CF_REG_ERR	0x080D

  #define RB500_CF_REG_CTRL	0x080E

  /* 32bit buffered data register offset */
  #define RB500_CF_REG_DBUF32	0x0C00

  struct rb532_cf_info {

  	void __iomem	*iobase;
  	unsigned int	gpio_line;

  	unsigned int	irq;
  };
  
  /* ------------------------------------------------------------------------ */

  static irqreturn_t rb532_pata_irq_handler(int irq, void *dev_instance)

  {
  	struct ata_host *ah = dev_instance;

  	struct rb532_cf_info *info = ah->private_data;

  
  	if (gpio_get_value(info->gpio_line)) {

  		irq_set_irq_type(info->irq, IRQ_TYPE_LEVEL_LOW);

  		ata_sff_interrupt(info->irq, dev_instance);

  	} else {

  		irq_set_irq_type(info->irq, IRQ_TYPE_LEVEL_HIGH);

  	}
  
  	return IRQ_HANDLED;
  }

  static struct ata_port_operations rb532_pata_port_ops = {

  	.inherits		= &ata_sff_port_ops,

  	.sff_data_xfer		= ata_sff_data_xfer32,

  };
  
  /* ------------------------------------------------------------------------ */

  static struct scsi_host_template rb532_pata_sht = {

  	ATA_PIO_SHT(DRV_NAME),

  };
  
  /* ------------------------------------------------------------------------ */

  static void rb532_pata_setup_ports(struct ata_host *ah)

  {

  	struct rb532_cf_info *info = ah->private_data;

  	struct ata_port *ap;
  
  	ap = ah->ports[0];

  	ap->ops		= &rb532_pata_port_ops;

  	ap->pio_mask	= ATA_PIO4;

  	ap->ioaddr.cmd_addr	= info->iobase + RB500_CF_REG_BASE;

  	ap->ioaddr.ctl_addr	= info->iobase + RB500_CF_REG_CTRL;
  	ap->ioaddr.altstatus_addr = info->iobase + RB500_CF_REG_CTRL;

  	ata_sff_std_ports(&ap->ioaddr);

  	ap->ioaddr.data_addr	= info->iobase + RB500_CF_REG_DBUF32;
  	ap->ioaddr.error_addr	= info->iobase + RB500_CF_REG_ERR;

  }

  static __devinit int rb532_pata_driver_probe(struct platform_device *pdev)

  {

  	int irq;

  	int gpio;
  	struct resource *res;
  	struct ata_host *ah;

  	struct rb532_cf_info *info;

  	int ret;
  
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!res) {
  		dev_err(&pdev->dev, "no IOMEM resource found
  ");
  		return -EINVAL;
  	}
  
  	irq = platform_get_irq(pdev, 0);
  	if (irq <= 0) {
  		dev_err(&pdev->dev, "no IRQ resource found
  ");
  		return -ENOENT;
  	}
  
  	gpio = irq_to_gpio(irq);
  	if (gpio < 0) {
  		dev_err(&pdev->dev, "no GPIO found for irq%d
  ", irq);
  		return -ENOENT;
  	}
  
  	ret = gpio_request(gpio, DRV_NAME);
  	if (ret) {
  		dev_err(&pdev->dev, "GPIO request failed
  ");
  		return ret;
  	}
  
  	/* allocate host */
  	ah = ata_host_alloc(&pdev->dev, RB500_CF_MAXPORTS);
  	if (!ah)
  		return -ENOMEM;
  
  	platform_set_drvdata(pdev, ah);
  
  	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
  	if (!info)
  		return -ENOMEM;
  
  	ah->private_data = info;
  	info->gpio_line = gpio;
  	info->irq = irq;
  
  	info->iobase = devm_ioremap_nocache(&pdev->dev, res->start,

  				resource_size(res));

  	if (!info->iobase)
  		return -ENOMEM;
  
  	ret = gpio_direction_input(gpio);
  	if (ret) {
  		dev_err(&pdev->dev, "unable to set GPIO direction, err=%d
  ",
  				ret);
  		goto err_free_gpio;
  	}

  	rb532_pata_setup_ports(ah);

  	ret = ata_host_activate(ah, irq, rb532_pata_irq_handler,
  				IRQF_TRIGGER_LOW, &rb532_pata_sht);

  	if (ret)
  		goto err_free_gpio;
  
  	return 0;
  
  err_free_gpio:
  	gpio_free(gpio);
  
  	return ret;
  }

  static __devexit int rb532_pata_driver_remove(struct platform_device *pdev)

  {
  	struct ata_host *ah = platform_get_drvdata(pdev);

  	struct rb532_cf_info *info = ah->private_data;

  
  	ata_host_detach(ah);
  	gpio_free(info->gpio_line);
  
  	return 0;
  }

  static struct platform_driver rb532_pata_platform_driver = {
  	.probe		= rb532_pata_driver_probe,
  	.remove		= __devexit_p(rb532_pata_driver_remove),

  	.driver	 = {
  		.name   = DRV_NAME,
  		.owner  = THIS_MODULE,
  	},
  };

  #define DRV_INFO DRV_DESC " version " DRV_VERSION

  module_platform_driver(rb532_pata_platform_driver);

  
  MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
  MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
  MODULE_DESCRIPTION(DRV_DESC);
  MODULE_VERSION(DRV_VERSION);
  MODULE_LICENSE("GPL");

  MODULE_ALIAS("platform:" DRV_NAME);