return mdc800;
}


/*
 * Disconnect USB device (maybe the MDC800)
 */
static void mdc800_usb_disconnect (struct usb_device *dev,void* ptr)
{
	struct mdc800_data* mdc800=(struct mdc800_data*) ptr;

	dbg ("(mdc800_usb_disconnect) called");

	if (mdc800->state == NOT_CONNECTED)
		return;
	
	usb_deregister_dev (&mdc800_usb_driver, 1, mdc800->minor);

	mdc800->state=NOT_CONNECTED;

	usb_unlink_urb (mdc800->irq_urb);
	usb_unlink_urb (mdc800->write_urb);
	usb_unlink_urb (mdc800->download_urb);

	usb_driver_release_interface (&mdc800_usb_driver, &dev->actconfig->interface[1]);

	mdc800->dev=0;
	info ("Mustek MDC800 disconnected from USB.");
}


/***************************************************************************
	The Misc device Part (file_operations)
****************************************************************************/

/*
 * This Function calc the Answersize for a command.
 */
static int mdc800_getAnswerSize (char command)
{
	switch ((unsigned char) command)
	{
		case 0x2a:
		case 0x49:
		case 0x51:
		case 0x0d:
		case 0x20:
		case 0x07:
		case 0x01:
		case 0x25:
		case 0x00:
			return 8;

		case 0x05:
		case 0x3e:
			return mdc800->pic_len;

		case 0x09:
			return 4096;

		default:
			return 0;
	}
}


/*
 * Init the device: (1) alloc mem (2) Increase MOD Count ..
 */
static int mdc800_device_open (struct inode* inode, struct file *file)
{
	int retval=0;
	int errn=0;

	down (&mdc800->io_lock);
	
	if (mdc800->state == NOT_CONNECTED)
	{
		errn=-EBUSY;
		goto error_out;
	}
	if (mdc800->open)
	{
		errn=-EBUSY;
		goto error_out;
	}

	mdc800->in_count=0;
	mdc800->out_count=0;
	mdc800->out_ptr=0;
	mdc800->pic_index=0;
	mdc800->pic_len=-1;
	mdc800->download_left=0;

	mdc800->camera_busy=0;
	mdc800->camera_request_ready=0;

	retval=0;
	mdc800->irq_urb->dev = mdc800->dev;
	if (usb_submit_urb (mdc800->irq_urb, GFP_KERNEL))
	{
		err ("request USB irq fails (submit_retval=%i urb_status=%i).",retval, mdc800->irq_urb->status);
		errn = -EIO;
		goto error_out;
	}

	mdc800->open=1;
	dbg ("Mustek MDC800 device opened.");

error_out:
	up (&mdc800->io_lock);
	return errn;
}


/*
 * Close the Camera and release Memory
 */
static int mdc800_device_release (struct inode* inode, struct file *file)
{
	int retval=0;
	dbg ("Mustek MDC800 device closed.");

	down (&mdc800->io_lock);
	if (mdc800->open && (mdc800->state != NOT_CONNECTED))
	{
		usb_unlink_urb (mdc800->irq_urb);
		usb_unlink_urb (mdc800->write_urb);
		usb_unlink_urb (mdc800->download_urb);
		mdc800->open=0;
	}
	else
	{
		retval=-EIO;
	}

	up(&mdc800->io_lock);
	return retval;
}


/*
 * The Device read callback Function
 */
static ssize_t mdc800_device_read (struct file *file, char *buf, size_t len, loff_t *pos)
{
	int   left=len, sts=len; /* single transfer size */
	char* ptr=buf;
	DECLARE_WAITQUEUE(wait, current);

	down (&mdc800->io_lock);
	if (mdc800->state == NOT_CONNECTED)
	{
		up (&mdc800->io_lock);
		return -EBUSY;
	}
	if (mdc800->state == WORKING)
	{
		warn ("Illegal State \"working\" reached during read ?!");
		up (&mdc800->io_lock);
		return -EBUSY;
	}
	if (!mdc800->open)
	{
		up (&mdc800->io_lock);
		return -EBUSY;
	}

	while (left)
	{
		if (signal_pending (current)) 
		{
			up (&mdc800->io_lock);
			return -EINTR;
		}

		sts=left > (mdc800->out_count-mdc800->out_ptr)?mdc800->out_count-mdc800->out_ptr:left;

		if (sts <= 0)
		{
			/* Too less Data in buffer */
			if (mdc800->state == DOWNLOAD)
			{
				mdc800->out_count=0;
				mdc800->out_ptr=0;

				/* Download -> Request new bytes */
				mdc800->download_urb->dev = mdc800->dev;
				if (usb_submit_urb (mdc800->download_urb, GFP_KERNEL))
				{
					err ("Can't submit download urb (status=%i)",mdc800->download_urb->status);
					up (&mdc800->io_lock);
					return len-left;
				}
				add_wait_queue(&mdc800->download_wait, &wait);
				set_current_state(TASK_INTERRUPTIBLE);
				if (!mdc800->downloaded)
				{
					schedule_timeout (TO_DOWNLOAD_GET_READY*HZ/1000);
				}
				set_current_state(TASK_RUNNING);
				remove_wait_queue(&mdc800->download_wait, &wait);
				mdc800->downloaded = 0;
				if (mdc800->download_urb->status != 0)
				{
					err ("request download-bytes fails (status=%i)",mdc800->download_urb->status);
					up (&mdc800->io_lock);
					return len-left;
				}
			}
			else
			{
				/* No more bytes -> that's an error*/
				up (&mdc800->io_lock);
				return -EIO;
			}
		}
		else
		{
			/* memcpy Bytes */
			memcpy (ptr, &mdc800->out [mdc800->out_ptr], sts);
			ptr+=sts;
			left-=sts;
			mdc800->out_ptr+=sts;
		}
	}

	up (&mdc800->io_lock);
	return len-left;
}


/*
 * The Device write callback Function
 * If a 8Byte Command is received, it will be send to the camera.
 * After this the driver initiates the request for the answer or
 * just waits until the camera becomes ready.
 */
static ssize_t mdc800_device_write (struct file *file, const char *buf, size_t len, loff_t *pos)
{
	int i=0;
	DECLARE_WAITQUEUE(wait, current);

	down (&mdc800->io_lock);
	if (mdc800->state != READY)
	{
		up (&mdc800->io_lock);
		return -EBUSY;
	}
	if (!mdc800->open )
	{
		up (&mdc800->io_lock);
		return -EBUSY;
	}

	while (i<len)
	{
		if (signal_pending (current)) 
		{
			up (&mdc800->io_lock);
			return -EINTR;
		}

		/* check for command start */
		if (buf [i] == (char) 0x55)
		{
			mdc800->in_count=0;
			mdc800->out_count=0;
			mdc800->out_ptr=0;
			mdc800->download_left=0;
		}

		/* save command byte */
		if (mdc800->in_count < 8)
		{
			mdc800->in[mdc800->in_count]=buf[i];
			mdc800->in_count++;
		}
		else
		{
			err ("Command is to long !\n");
			up (&mdc800->io_lock);
			return -EIO;
		}

		/* Command Buffer full ? -> send it to camera */
		if (mdc800->in_count == 8)
		{
			int answersize;

			if (mdc800_usb_waitForIRQ (0,TO_GET_READY))
			{
				err ("Camera didn't get ready.\n");
				up (&mdc800->io_lock);
				return -EIO;
			}

			answersize=mdc800_getAnswerSize (mdc800->in[1]);

			mdc800->state=WORKING;
			memcpy (mdc800->write_urb->transfer_buffer, mdc800->in,8);
			mdc800->write_urb->dev = mdc800->dev;
			if (usb_submit_urb (mdc800->write_urb, GFP_KERNEL))
			{
				err ("submitting write urb fails (status=%i)", mdc800->write_urb->status);
				up (&mdc800->io_lock);
				return -EIO;
			}
			add_wait_queue(&mdc800->write_wait, &wait);
			set_current_state(TASK_INTERRUPTIBLE);
			if (!mdc800->written)
			{
				schedule_timeout (TO_WRITE_GET_READY*HZ/1000);
			}
                        set_current_state(TASK_RUNNING);
			remove_wait_queue(&mdc800->write_wait, &wait);
			mdc800->written = 0;
			if (mdc800->state == WORKING)
			{
				usb_unlink_urb (mdc800->write_urb);
				up (&mdc800->io_lock);
				return -EIO;
			}

			switch ((unsigned char) mdc800->in[1])
			{
				case 0x05: /* Download Image */
				case 0x3e: /* Take shot in Fine Mode (WCam Mode) */
					if (mdc800->pic_len < 0)
					{
						err ("call 0x07 before 0x05,0x3e");
						mdc800->state=READY;
						up (&mdc800->io_lock);
						return -EIO;
					}
					mdc800->pic_len=-1;

				case 0x09: /* Download Thumbnail */
					mdc800->download_left=answersize+64;
					mdc800->state=DOWNLOAD;
					mdc800_usb_waitForIRQ (0,TO_DOWNLOAD_GET_BUSY);
					break;


				default:
					if (answersize)
					{

						if (mdc800_usb_waitForIRQ (1,TO_READ_FROM_IRQ))
						{
							err ("requesting answer from irq fails");
							up (&mdc800->io_lock);
							return -EIO;
						}

						/* Write dummy data, (this is ugly but part of the USB Protokoll */
						/* if you use endpoint 1 as bulk and not as irq */
						memcpy (mdc800->out, mdc800->camera_response,8);

						/* This is the interpreted answer */
						memcpy (&mdc800->out[8], mdc800->camera_response,8);

						mdc800->out_ptr=0;
						mdc800->out_count=16;

						/* Cache the Imagesize, if command was getImageSize */
						if (mdc800->in [1] == (char) 0x07)
						{
							mdc800->pic_len=(int) 65536*(unsigned char) mdc800->camera_response[0]+256*(unsigned char) mdc800->camera_response[1]+(unsigned char) mdc800->camera_response[2];

							dbg ("cached imagesize = %i",mdc800->pic_len);
						}

					}
					else
					{
						if (mdc800_usb_waitForIRQ (0,TO_DEFAULT_COMMAND))
						{
							err ("Command Timeout.");
							up (&mdc800->io_lock);
							return -EIO;
						}
					}
					mdc800->state=READY;
					break;
			}
		}
		i++;
	}
	up (&mdc800->io_lock);
	return i;
}


/***************************************************************************
	Init and Cleanup this driver (Structs and types)
****************************************************************************/

/* File Operations of this drivers */
static struct file_operations mdc800_device_ops =
{
	owner:		THIS_MODULE,
	read:		mdc800_device_read,
	write:		mdc800_device_write,
	open:		mdc800_device_open,
	release:	mdc800_device_release,
};



static struct usb_device_id mdc800_table [] = {
	{ USB_DEVICE(MDC800_VENDOR_ID, MDC800_PRODUCT_ID) },
	{ }						/* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, mdc800_table);
/*
 * USB Driver Struct for this device
 */
static struct usb_driver mdc800_usb_driver =
{
	name:		"mdc800",
	probe:		mdc800_usb_probe,
	disconnect:	mdc800_usb_disconnect,
	fops:		&mdc800_device_ops,
	minor:		MDC800_DEVICE_MINOR_BASE,
	num_minors:	1,
	id_table:	mdc800_table
};



/************************************************************************
	Init and Cleanup this driver (Main Functions)
*************************************************************************/

#define try(A)           if ((A) == 0) goto cleanup_on_fail;
#define try_free_mem(A)  if (A != 0) { kfree (A); A=0; }
#define try_free_urb(A)  if (A != 0) { usb_free_urb (A); A=0; }

int __init usb_mdc800_init (void)
{
	/* Allocate Memory */
	try (mdc800=kmalloc (sizeof (struct mdc800_data), GFP_KERNEL));

	memset(mdc800, 0, sizeof(struct mdc800_data));
	mdc800->dev=0;
	mdc800->open=0;
	mdc800->state=NOT_CONNECTED;
	init_MUTEX (&mdc800->io_lock);

	init_waitqueue_head (&mdc800->irq_wait);
	init_waitqueue_head (&mdc800->write_wait);
	init_waitqueue_head (&mdc800->download_wait);

	mdc800->irq_woken = 0;
	mdc800->downloaded = 0;
	mdc800->written = 0;

	try (mdc800->irq_urb_buffer=kmalloc (8, GFP_KERNEL));
	try (mdc800->write_urb_buffer=kmalloc (8, GFP_KERNEL));
	try (mdc800->download_urb_buffer=kmalloc (64, GFP_KERNEL));

	try (mdc800->irq_urb=usb_alloc_urb (0, GFP_KERNEL));
	try (mdc800->download_urb=usb_alloc_urb (0, GFP_KERNEL));
	try (mdc800->write_urb=usb_alloc_urb (0, GFP_KERNEL));

	/* Register the driver */
	if (usb_register (&mdc800_usb_driver) < 0)
		goto cleanup_on_fail;

	info (DRIVER_VERSION ":" DRIVER_DESC);

	return 0;

	/* Clean driver up, when something fails */

cleanup_on_fail:

	if (mdc800 != 0)
	{
		err ("can't alloc memory!");

		try_free_mem (mdc800->download_urb_buffer);
		try_free_mem (mdc800->write_urb_buffer);
		try_free_mem (mdc800->irq_urb_buffer);

		try_free_urb (mdc800->write_urb);
		try_free_urb (mdc800->download_urb);
		try_free_urb (mdc800->irq_urb);

		kfree (mdc800);
	}
	mdc800=0;
	return -1;
}


void __exit usb_mdc800_cleanup (void)
{
	usb_deregister (&mdc800_usb_driver);

	usb_free_urb (mdc800->irq_urb);
	usb_free_urb (mdc800->download_urb);
	usb_free_urb (mdc800->write_urb);

	kfree (mdc800->irq_urb_buffer);
	kfree (mdc800->write_urb_buffer);
	kfree (mdc800->download_urb_buffer);

	kfree (mdc800);
	mdc800=0;
}

module_init (usb_mdc800_init);
module_exit (usb_mdc800_cleanup);

MODULE_AUTHOR( DRIVER_AUTHOR );
MODULE_DESCRIPTION( DRIVER_DESC );
MODULE_LICENSE("GPL");