/*
 * Linux Broadcom BCM47xx GPIO char driver
 *
 * Copyright 2007, Broadcom Corporation
 * All Rights Reserved.
 * 
 * THIS SOFTWARE IS OFFERED "AS IS", AND BROADCOM GRANTS NO WARRANTIES OF ANY
 * KIND, EXPRESS OR IMPLIED, BY STATUTE, COMMUNICATION OR OTHERWISE. BROADCOM
 * SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A SPECIFIC PURPOSE OR NONINFRINGEMENT CONCERNING THIS SOFTWARE.
 * $Id$
 *
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <asm/uaccess.h>

#include <typedefs.h>
#include <bcmutils.h>
#include <sbutils.h>
#include <bcmdevs.h>

#include <linux_gpio.h>

/* handle to the sb */
static sb_t *gpio_sbh;

/* major number assigned to the device and device handles */
static int gpio_major;
devfs_handle_t gpiodev_handle;

static int
gpio_open (struct inode *inode, struct file *file)
{
  MOD_INC_USE_COUNT;
  return 0;
}

static int
gpio_release (struct inode *inode, struct file *file)
{
  MOD_DEC_USE_COUNT;
  return 0;
}

static int
gpio_ioctl (struct inode *inode, struct file *file, unsigned int cmd,
	    unsigned long arg)
{
  struct gpio_ioctl gpioioc;

  if (copy_from_user
      (&gpioioc, (struct gpio_ioctl *) arg, sizeof (struct gpio_ioctl)))
    return -EFAULT;

  switch (cmd)
    {
    case GPIO_IOC_RESERVE:
      gpioioc.val =
	sb_gpioreserve (gpio_sbh, gpioioc.mask, GPIO_APP_PRIORITY);
      break;
    case GPIO_IOC_RELEASE:
      /*
       * releasing the gpio doesn't change the current
       * value on the GPIO last write value
       * persists till some one overwrites it
       */
      gpioioc.val =
	sb_gpiorelease (gpio_sbh, gpioioc.mask, GPIO_APP_PRIORITY);
      break;
    case GPIO_IOC_OUT:
      gpioioc.val = sb_gpioout (gpio_sbh, gpioioc.mask, gpioioc.val,
				GPIO_APP_PRIORITY);
      break;
    case GPIO_IOC_OUTEN:
      gpioioc.val = sb_gpioouten (gpio_sbh, gpioioc.mask, gpioioc.val,
				  GPIO_APP_PRIORITY);
      break;
    case GPIO_IOC_IN:
      gpioioc.val = sb_gpioin (gpio_sbh);
      break;
    default:
      break;
    }
  if (copy_to_user
      ((struct gpio_ioctl *) arg, &gpioioc, sizeof (struct gpio_ioctl)))
    return -EFAULT;

  return 0;

}
static struct file_operations gpio_fops = {
owner:THIS_MODULE,
open:gpio_open,
release:gpio_release,
ioctl:gpio_ioctl,
};

static int __init
gpio_init (void)
{
  if (!(gpio_sbh = sb_kattach (SB_OSH)))
    return -ENODEV;

  if ((gpio_major = devfs_register_chrdev (0, "gpio", &gpio_fops)) < 0)
    return gpio_major;

  gpiodev_handle = devfs_register (NULL, "gpio", DEVFS_FL_DEFAULT,
				   gpio_major, 0, S_IFCHR | S_IRUGO | S_IWUGO,
				   &gpio_fops, NULL);

  return 0;
}

static void __exit
gpio_exit (void)
{
  if (gpiodev_handle != NULL)
    devfs_unregister (gpiodev_handle);
  gpiodev_handle = NULL;
  devfs_unregister_chrdev (gpio_major, "gpio");
  sb_detach (gpio_sbh);
}

module_init (gpio_init);
module_exit (gpio_exit);