/*

   * Driver for GE FPGA based GPIO

   *

   * Author: Martyn Welch <martyn.welch@ge.com>

   *

   * 2008 (c) GE Intelligent Platforms Embedded Systems, Inc.

   *
   * This file is licensed under the terms of the GNU General Public License
   * version 2.  This program is licensed "as is" without any warranty of any
   * kind, whether express or implied.
   */
  
  /* TODO
   *
   * Configuration of output modes (totem-pole/open-drain)
   * Interrupt configuration - interrupts are always generated the FPGA relies on

   * the I/O interrupt controllers mask to stop them propergating

   */
  
  #include <linux/kernel.h>

  #include <linux/io.h>

  #include <linux/slab.h>

  #include <linux/of_device.h>

  #include <linux/of_gpio.h>

  #include <linux/of_address.h>

  #include <linux/module.h>

  #include <linux/gpio/driver.h>

  
  #define GEF_GPIO_DIRECT		0x00
  #define GEF_GPIO_IN		0x04
  #define GEF_GPIO_OUT		0x08
  #define GEF_GPIO_TRIG		0x0C
  #define GEF_GPIO_POLAR_A	0x10
  #define GEF_GPIO_POLAR_B	0x14
  #define GEF_GPIO_INT_STAT	0x18
  #define GEF_GPIO_OVERRUN	0x1C
  #define GEF_GPIO_MODE		0x20

  static const struct of_device_id gef_gpio_ids[] = {
  	{
  		.compatible	= "gef,sbc610-gpio",
  		.data		= (void *)19,
  	}, {
  		.compatible	= "gef,sbc310-gpio",
  		.data		= (void *)6,
  	}, {
  		.compatible	= "ge,imp3a-gpio",
  		.data		= (void *)16,
  	},
  	{ }
  };
  MODULE_DEVICE_TABLE(of, gef_gpio_ids);

  static int __init gef_gpio_probe(struct platform_device *pdev)

  {

  	const struct of_device_id *of_id =
  		of_match_device(gef_gpio_ids, &pdev->dev);

  	struct gpio_chip *gc;

  	void __iomem *regs;
  	int ret;

  	gc = devm_kzalloc(&pdev->dev, sizeof(*gc), GFP_KERNEL);
  	if (!gc)

  		return -ENOMEM;

  	regs = of_iomap(pdev->dev.of_node, 0);
  	if (!regs)
  		return -ENOMEM;

  	ret = bgpio_init(gc, &pdev->dev, 4, regs + GEF_GPIO_IN,

  			 regs + GEF_GPIO_OUT, NULL, NULL,
  			 regs + GEF_GPIO_DIRECT, BGPIOF_BIG_ENDIAN_BYTE_ORDER);
  	if (ret) {
  		dev_err(&pdev->dev, "bgpio_init failed
  ");
  		goto err0;
  	}

  	/* Setup pointers to chip functions */

  	gc->label = devm_kstrdup(&pdev->dev, pdev->dev.of_node->full_name,

  				     GFP_KERNEL);

  	if (!gc->label) {

  		ret = -ENOMEM;

  		goto err0;

  	}

  	gc->base = -1;
  	gc->ngpio = (u16)(uintptr_t)of_id->data;
  	gc->of_gpio_n_cells = 2;
  	gc->of_node = pdev->dev.of_node;

  
  	/* This function adds a memory mapped GPIO chip */

  	ret = devm_gpiochip_add_data(&pdev->dev, gc, NULL);

  	if (ret)

  		goto err0;

  
  	return 0;

  err0:
  	iounmap(regs);
  	pr_err("%s: GPIO chip registration failed
  ",
  			pdev->dev.of_node->full_name);
  	return ret;

  };

  static struct platform_driver gef_gpio_driver = {
  	.driver = {
  		.name		= "gef-gpio",

  		.of_match_table	= gef_gpio_ids,
  	},

  };

  module_platform_driver_probe(gef_gpio_driver, gef_gpio_probe);

  MODULE_DESCRIPTION("GE I/O FPGA GPIO driver");
  MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com");

  MODULE_LICENSE("GPL");