linux/drivers/media/video/dabusb.c

/*****************************************************************************/

/*
 *      dabusb.c  --  dab usb driver.
 *
 *      Copyright (C) 1999  Deti Fliegl (deti@fliegl.de)
 *
 *      This program is free software; you can redistribute it and/or modify
 *      it under the terms of the GNU General Public License as published by
 *      the Free Software Foundation; either version 2 of the License, or
 *      (at your option) any later version.
 *
 *      This program is distributed in the hope that it will be useful,
 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *      GNU General Public License for more details.
 *
 *      You should have received a copy of the GNU General Public License
 *      along with this program; if not, write to the Free Software
 *      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *
 *
 *  $Id: dabusb.c,v 1.54 2000/07/24 21:39:39 deti Exp $
 *
 */

/*****************************************************************************/

#include <linux/module.h>
#include <linux/socket.h>
#include <linux/list.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/init.h>
#include <asm/uaccess.h>
#include <asm/atomic.h>
#include <linux/delay.h>
#include <linux/usb.h>
#include <linux/mutex.h>
#include <linux/firmware.h>
#include <linux/ihex.h>

#include "dabusb.h"

/*
 * Version Information
 */
#define DRIVER_VERSION "v1.54"
#define DRIVER_AUTHOR "Deti Fliegl, deti@fliegl.de"
#define DRIVER_DESC "DAB-USB Interface Driver for Linux (c)1999"

/* --------------------------------------------------------------------- */

#ifdef CONFIG_USB_DYNAMIC_MINORS
#define NRDABUSB 256
#else
#define NRDABUSB 4
#endif

/*-------------------------------------------------------------------*/

static dabusb_t dabusb[NRDABUSB];
static int buffers = 256;
static struct usb_driver dabusb_driver;

/*-------------------------------------------------------------------*/

static int dabusb_add_buf_tail (pdabusb_t s, struct list_head *dst, struct list_head *src)
{
	unsigned long flags;
	struct list_head *tmp;
	int ret = 0;

	spin_lock_irqsave (&s->lock, flags);

	if (list_empty (src)) {
		// no elements in source buffer
		ret = -1;
		goto err;
	}
	tmp = src->next;
	list_move_tail (tmp, dst);

  err:	spin_unlock_irqrestore (&s->lock, flags);
	return ret;
}
/*-------------------------------------------------------------------*/
#ifdef DEBUG
static void dump_urb (struct urb *urb)
{
	dbg("urb                   :%p", urb);
	dbg("dev                   :%p", urb->dev);
	dbg("pipe                  :%08X", urb->pipe);
	dbg("status                :%d", urb->status);
	dbg("transfer_flags        :%08X", urb->transfer_flags);
	dbg("transfer_buffer       :%p", urb->transfer_buffer);
	dbg("transfer_buffer_length:%d", urb->transfer_buffer_length);
	dbg("actual_length         :%d", urb->actual_length);
	dbg("setup_packet          :%p", urb->setup_packet);
	dbg("start_frame           :%d", urb->start_frame);
	dbg("number_of_packets     :%d", urb->number_of_packets);
	dbg("interval              :%d", urb->interval);
	dbg("error_count           :%d", urb->error_count);
	dbg("context               :%p", urb->context);
	dbg("complete              :%p", urb->complete);
}
#endif
/*-------------------------------------------------------------------*/
static int dabusb_cancel_queue (pdabusb_t s, struct list_head *q)
{
	unsigned long flags;
	pbuff_t b;

	dbg("dabusb_cancel_queue");

	spin_lock_irqsave (&s->lock, flags);

	list_for_each_entry(b, q, buff_list) {
#ifdef DEBUG
		dump_urb(b->purb);
#endif
		usb_unlink_urb (b->purb);
	}
	spin_unlock_irqrestore (&s->lock, flags);
	return 0;
}
/*-------------------------------------------------------------------*/
static int dabusb_free_queue (struct list_head *q)
{
	struct list_head *tmp;
	struct list_head *p;
	pbuff_t b;

	dbg("dabusb_free_queue");
	for (p = q->next; p != q;) {
		b = list_entry (p, buff_t, buff_list);

#ifdef DEBUG
		dump_urb(b->purb);
#endif
		kfree(b->purb->transfer_buffer);
		usb_free_urb(b->purb);
		tmp = p->next;
		list_del (p);
		kfree (b);
		p = tmp;
	}

	return 0;
}
/*-------------------------------------------------------------------*/
static int dabusb_free_buffers (pdabusb_t s)
{
	unsigned long flags;
	dbg("dabusb_free_buffers");

	spin_lock_irqsave(&s->lock, flags);

	dabusb_free_queue (&s->free_buff_list);
	dabusb_free_queue (&s->rec_buff_list);

	spin_unlock_irqrestore(&s->lock, flags);

	s->got_mem = 0;
	return 0;
}
/*-------------------------------------------------------------------*/
static void dabusb_iso_complete (struct urb *purb)
{
	pbuff_t b = purb->context;
	pdabusb_t s = b->s;
	int i;
	int len;
	int dst = 0;
	void *buf = purb->transfer_buffer;

	dbg("dabusb_iso_complete");

	// process if URB was not killed
	if (purb->status != -ENOENT) {
		unsigned int pipe = usb_rcvisocpipe (purb->dev, _DABUSB_ISOPIPE);
		int pipesize = usb_maxpacket (purb->dev, pipe, usb_pipeout (pipe));
		for (i = 0; i < purb->number_of_packets; i++)
			if (!purb->iso_frame_desc[i].status) {
				len = purb->iso_frame_desc[i].actual_length;
				if (len <= pipesize) {
					memcpy (buf + dst, buf + purb->iso_frame_desc[i].offset, len);
					dst += len;
				}
				else
					dev_err(&purb->dev->dev,
						"dabusb_iso_complete: invalid len %d\n", len);
			}
			else
				dev_warn(&purb->dev->dev, "dabusb_iso_complete: corrupted packet status: %d\n", purb->iso_frame_desc[i].status);
		if (dst != purb->actual_length)
			dev_err(&purb->dev->dev,
				"dst!=purb->actual_length:%d!=%d\n",
					dst, purb->actual_length);
	}

	if (atomic_dec_and_test (&s->pending_io) && !s->remove_pending && s->state != _stopped) {
		s->overruns++;
		dev_err(&purb->dev->dev, "overrun (%d)\n", s->overruns);
	}
	wake_up (&s->wait);
}
/*-------------------------------------------------------------------*/
static int dabusb_alloc_buffers (pdabusb_t s)
{
	int transfer_len = 0;
	pbuff_t b;
	unsigned int pipe = usb_rcvisocpipe (s->usbdev, _DABUSB_ISOPIPE);
	int pipesize = usb_maxpacket (s->usbdev, pipe, usb_pipeout (pipe));
	int packets = _ISOPIPESIZE / pipesize;
	int transfer_buffer_length = packets * pipesize;
	int i;

	dbg("dabusb_alloc_buffers pipesize:%d packets:%d transfer_buffer_len:%d",
		 pipesize, packets, transfer_buffer_length);

	while (transfer_len < (s->total_buffer_size << 10)) {
		b = kzalloc(sizeof (buff_t), GFP_KERNEL);
		if (!b) {
			dev_err(&s->usbdev->dev,
				"kzalloc(sizeof(buff_t))==NULL\n");
			goto err;
		}
		b->s = s;
		b->purb = usb_alloc_urb(packets, GFP_KERNEL);
		if (!b->purb) {
			dev_err(&s->usbdev->dev, "usb_alloc_urb == NULL\n");
			kfree (b);
			goto err;
		}

		b->purb->transfer_buffer = kmalloc (transfer_buffer_length, GFP_KERNEL);
		if (!b->purb->transfer_buffer) {
			kfree (b->purb);
			kfree (b);
			dev_err(&s->usbdev->dev,
				"kmalloc(%d)==NULL\n", transfer_buffer_length);
			goto err;
		}

		b->purb->transfer_buffer_length = transfer_buffer_length;
		b->purb->number_of_packets = packets;
		b->purb->complete = dabusb_iso_complete;
		b->purb->context = b;
		b->purb->dev = s->usbdev;
		b->purb->pipe = pipe;
		b->purb->transfer_flags = URB_ISO_ASAP;

		for (i = 0; i < packets; i++) {
			b->purb->iso_frame_desc[i].offset = i * pipesize;
			b->purb->iso_frame_desc[i].length = pipesize;
		}

		transfer_len += transfer_buffer_length;
		list_add_tail (&b->buff_list, &s->free_buff_list);
	}
	s->got_mem = transfer_len;

	return 0;

	err:
	dabusb_free_buffers (s);
	return -ENOMEM;
}
/*-------------------------------------------------------------------*/
static int dabusb_bulk (pdabusb_t s, pbulk_transfer_t pb)
{
	int ret;
	unsigned int pipe;
	int actual_length;

	dbg("dabusb_bulk");

	if (!pb->pipe)
		pipe = usb_rcvbulkpipe (s->usbdev, 2);
	else
		pipe = usb_sndbulkpipe (s->usbdev, 2);

	ret=usb_bulk_msg(s->usbdev, pipe, pb->data, pb->size, &actual_length, 100);
	if(ret<0) {
		dev_err(&s->usbdev->dev,
			"usb_bulk_msg failed(%d)\n", ret);

		if (usb_set_interface (s->usbdev, _DABUSB_IF, 1) < 0) {
			dev_err(&s->usbdev->dev, "set_interface failed\n");
			return -EINVAL;
		}

	}

	if( ret == -EPIPE ) {
		dev_warn(&s->usbdev->dev, "CLEAR_FEATURE request to remove STALL condition.\n");
		if(usb_clear_halt(s->usbdev, usb_pipeendpoint(pipe)))
			dev_err(&s->usbdev->dev, "request failed\n");
	}

	pb->size = actual_length;
	return ret;
}
/* --------------------------------------------------------------------- */
static int dabusb_writemem (pdabusb_t s, int pos, const unsigned char *data,
			    int len)
{
	int ret;
	unsigned char *transfer_buffer =  kmalloc (len, GFP_KERNEL);

	if (!transfer_buffer) {
		dev_err(&s->usbdev->dev,
			"dabusb_writemem: kmalloc(%d) failed.\n", len);
		return -ENOMEM;
	}

	memcpy (transfer_buffer, data, len);

	ret=usb_control_msg(s->usbdev, usb_sndctrlpipe( s->usbdev, 0 ), 0xa0, 0x40, pos, 0, transfer_buffer, len, 300);

	kfree (transfer_buffer);
	return ret;
}
/* --------------------------------------------------------------------- */
static int dabusb_8051_reset (pdabusb_t s, unsigned char reset_bit)
{
	dbg("dabusb_8051_reset: %d",reset_bit);
	return dabusb_writemem (s, CPUCS_REG, &reset_bit, 1);
}
/* --------------------------------------------------------------------- */
static int dabusb_loadmem (pdabusb_t s, const char *fname)
{
	int ret;
	const struct ihex_binrec *rec;
	const struct firmware *uninitialized_var(fw);

	dbg("Enter dabusb_loadmem (internal)");

	ret = request_ihex_firmware(&fw, "dabusb/firmware.fw", &s->usbdev->dev);
	if (ret) {
		dev_err(&s->usbdev->dev,
			"Failed to load \"dabusb/firmware.fw\": %d\n", ret);
		goto out;
	}
	ret = dabusb_8051_reset (s, 1);

	for (rec = (const struct ihex_binrec *)fw->data; rec;
	     rec = ihex_next_binrec(rec)) {
		dbg("dabusb_writemem: %04X %p %d)", be32_to_cpu(rec->addr),
		    rec->data, be16_to_cpu(rec->len));

		ret = dabusb_writemem(s, be32_to_cpu(rec->addr), rec->data,
				       be16_to_cpu(rec->len));
		if (ret < 0) {
			dev_err(&s->usbdev->dev,
				"dabusb_writemem failed (%d %04X %p %d)\n",
				ret, be32_to_cpu(rec->addr),
				rec->data, be16_to_cpu(rec->len));
			break;
		}
	}
	ret = dabusb_8051_reset (s, 0);
	release_firmware(fw);
 out:
	dbg("dabusb_loadmem: exit");

	return ret;
}
/* --------------------------------------------------------------------- */
static int dabusb_fpga_clear (pdabusb_t s, pbulk_transfer_t b)
{
	b->size = 4;
	b->data[0] = 0x2a;
	b->data[1] = 0;
	b->data[2] = 0;
	b->data[3] = 0;

	dbg("dabusb_fpga_clear");

	return dabusb_bulk (s, b);
}
/* --------------------------------------------------------------------- */
static int dabusb_fpga_init (pdabusb_t s, pbulk_transfer_t b)
{
	b->size = 4;
	b->data[0] = 0x2c;
	b->data[1] = 0;
	b->data[2] = 0;
	b->data[3] = 0;

	dbg("dabusb_fpga_init");

	return dabusb_bulk (s, b);
}
/* --------------------------------------------------------------------- */
static int dabusb_fpga_download (pdabusb_t s, const char *fname)
{
	pbulk_transfer_t b = kmalloc (sizeof (bulk_transfer_t), GFP_KERNEL);
	const struct firmware *fw;
	unsigned int blen, n;
	int ret;

	dbg("Enter dabusb_fpga_download (internal)");

	if (!b) {
		dev_err(&s->usbdev->dev,
			"kmalloc(sizeof(bulk_transfer_t))==NULL\n");
		return -ENOMEM;
	}

	ret = request_firmware(&fw, "dabusb/bitstream.bin", &s->usbdev->dev);
	if (ret) {
		dev_err(&s->usbdev->dev,
			"Failed to load \"dabusb/bitstream.bin\": %d\n", ret);
		kfree(b);
		return ret;
	}

	b->pipe = 1;
	ret = dabusb_fpga_clear (s, b);
	mdelay (10);
	blen = fw->data[73] + (fw->data[72] << 8);

	dbg("Bitstream len: %i", blen);

	b->data[0] = 0x2b;
	b->data[1] = 0;
	b->data[2] = 0;
	b->data[3] = 60;

	for (n = 0; n <= blen + 60; n += 60) {
		// some cclks for startup
		b->size = 64;
		memcpy (b->data + 4, fw->data + 74 + n, 60);
		ret = dabusb_bulk (s, b);
		if (ret < 0) {
			dev_err(&s->usbdev->dev, "dabusb_bulk failed.\n");
			break;
		}
		mdelay (1);
	}

	ret = dabusb_fpga_init (s, b);
	kfree (b);
	release_firmware(fw);

	dbg("exit dabusb_fpga_download");

	return ret;
}

static int dabusb_stop (pdabusb_t s)
{
	dbg("dabusb_stop");

	s->state = _stopped;
	dabusb_cancel_queue (s, &s->rec_buff_list);

	dbg("pending_io: %d", s->pending_io.counter);

	s->pending_io.counter = 0;
	return 0;
}

static int dabusb_startrek (pdabusb_t s)
{
	if (!s->got_mem && s->state != _started) {

		dbg("dabusb_startrek");

		if (dabusb_alloc_buffers (s) < 0)
			return -ENOMEM;
		dabusb_stop (s);
		s->state = _started;
		s->readptr = 0;
	}

	if (!list_empty (&s->free_buff_list)) {
		pbuff_t end;
		int ret;

	while (!dabusb_add_buf_tail (s, &s->rec_buff_list, &s->free_buff_list)) {

			dbg("submitting: end:%p s->rec_buff_list:%p", s->rec_buff_list.prev, &s->rec_buff_list);

			end = list_entry (s->rec_buff_list.prev, buff_t, buff_list);

			ret = usb_submit_urb (end->purb, GFP_KERNEL);
			if (ret) {
				dev_err(&s->usbdev->dev,
					"usb_submit_urb returned:%d\n", ret);
				if (dabusb_add_buf_tail (s, &s->free_buff_list, &s->rec_buff_list))
					dev_err(&s->usbdev->dev,
						"startrek: dabusb_add_buf_tail failed\n");
				break;
			}
			else
				atomic_inc (&s->pending_io);
		}
		dbg("pending_io: %d",s->pending_io.counter);
	}

	return 0;
}

static ssize_t dabusb_read (struct file *file, char __user *buf, size_t count, loff_t * ppos)
{
	pdabusb_t s = (pdabusb_t) file->private_data;
	unsigned long flags;
	unsigned ret = 0;
	int rem;
	int cnt;
	pbuff_t b;
	struct urb *purb = NULL;

	dbg("dabusb_read");

	if (*ppos)
		return -ESPIPE;

	if (s->remove_pending)
		return -EIO;


	if (!s->usbdev)
		return -EIO;

	while (count > 0) {
		dabusb_startrek (s);

		spin_lock_irqsave (&s->lock, flags);

		if (list_empty (&s->rec_buff_list)) {

			spin_unlock_irqrestore(&s->lock, flags);

			dev_err(&s->usbdev->dev,
				"error: rec_buf_list is empty\n");
			goto err;
		}

		b = list_entry (s->rec_buff_list.next, buff_t, buff_list);
		purb = b->purb;

		spin_unlock_irqrestore(&s->lock, flags);

		if (purb->status == -EINPROGRESS) {
			if (file->f_flags & O_NONBLOCK)		// return nonblocking
			 {
				if (!ret)
					ret = -EAGAIN;
				goto err;
			}

			interruptible_sleep_on (&s->wait);

			if (signal_pending (current)) {
				if (!ret)
					ret = -ERESTARTSYS;
				goto err;
			}

			spin_lock_irqsave (&s->lock, flags);

			if (list_empty (&s->rec_buff_list)) {
				spin_unlock_irqrestore(&s->lock, flags);
				dev_err(&s->usbdev->dev,
					"error: still no buffer available.\n");
				goto err;
			}
			spin_unlock_irqrestore(&s->lock, flags);
			s->readptr = 0;
		}
		if (s->remove_pending) {
			ret = -EIO;
			goto err;
		}

		rem = purb->actual_length - s->readptr;		// set remaining bytes to copy

		if (count >= rem)
			cnt = rem;
		else
			cnt = count;

		dbg("copy_to_user:%p %p %d",buf, purb->transfer_buffer + s->readptr, cnt);

		if (copy_to_user (buf, purb->transfer_buffer + s->readptr, cnt)) {
			dev_err(&s->usbdev->dev, "read: copy_to_user failed\n");
			if (!ret)
				ret = -EFAULT;
			goto err;
		}

		s->readptr += cnt;
		count -= cnt;
		buf += cnt;
		ret += cnt;

		if (s->readptr == purb->actual_length) {
			// finished, take next buffer
			if (dabusb_add_buf_tail (s, &s->free_buff_list, &s->rec_buff_list))
				dev_err(&s->usbdev->dev,
					"read: dabusb_add_buf_tail failed\n");
			s->readptr = 0;
		}
	}
      err:			//mutex_unlock(&s->mutex);
	return ret;
}

static int dabusb_open (struct inode *inode, struct file *file)
{
	int devnum = iminor(inode);
	pdabusb_t s;

	if (devnum < DABUSB_MINOR || devnum >= (DABUSB_MINOR + NRDABUSB))
		return -EIO;

	s = &dabusb[devnum - DABUSB_MINOR];

	dbg("dabusb_open");
	mutex_lock(&s->mutex);

	while (!s->usbdev || s->opened) {
		mutex_unlock(&s->mutex);

		if (file->f_flags & O_NONBLOCK) {
			return -EBUSY;
		}
		msleep_interruptible(500);

		if (signal_pending (current)) {
			return -EAGAIN;
		}
		mutex_lock(&s->mutex);
	}
	if (usb_set_interface (s->usbdev, _DABUSB_IF, 1) < 0) {
		mutex_unlock(&s->mutex);
		dev_err(&s->usbdev->dev, "set_interface failed\n");
		return -EINVAL;
	}
	s->opened = 1;
	mutex_unlock(&s->mutex);

	file->f_pos = 0;
	file->private_data = s;

	return nonseekable_open(inode, file);
}

static int dabusb_release (struct inode *inode, struct file *file)
{
	pdabusb_t s = (pdabusb_t) file->private_data;

	dbg("dabusb_release");

	mutex_lock(&s->mutex);
	dabusb_stop (s);
	dabusb_free_buffers (s);
	mutex_unlock(&s->mutex);

	if (!s->remove_pending) {
		if (usb_set_interface (s->usbdev, _DABUSB_IF, 0) < 0)
			dev_err(&s->usbdev->dev, "set_interface failed\n");
	}
	else
		wake_up (&s->remove_ok);

	s->opened = 0;
	return 0;
}

static long dabusb_ioctl (struct file *file, unsigned int cmd, unsigned long arg)
{
	pdabusb_t s = (pdabusb_t) file->private_data;
	pbulk_transfer_t pbulk;
	int ret = 0;
	int version = DABUSB_VERSION;

	dbg("dabusb_ioctl");

	lock_kernel();
	if (s->remove_pending) {
		unlock_kernel();
		return -EIO;
	}

	mutex_lock(&s->mutex);

	if (!s->usbdev) {
		mutex_unlock(&s->mutex);
		unlock_kernel();
		return -EIO;
	}

	switch (cmd) {

	case IOCTL_DAB_BULK:
		pbulk = kmalloc(sizeof (bulk_transfer_t), GFP_KERNEL);

		if (!pbulk) {
			ret = -ENOMEM;
			break;
		}

		if (copy_from_user (pbulk, (void __user *) arg, sizeof (bulk_transfer_t))) {
			ret = -EFAULT;
			kfree (pbulk);
			break;
		}

		ret=dabusb_bulk (s, pbulk);
		if(ret==0)
			if (copy_to_user((void __user *)arg, pbulk,
					 sizeof(bulk_transfer_t)))
				ret = -EFAULT;
		kfree (pbulk);
		break;

	case IOCTL_DAB_OVERRUNS:
		ret = put_user (s->overruns, (unsigned int __user *) arg);
		break;

	case IOCTL_DAB_VERSION:
		ret = put_user (version, (unsigned int __user *) arg);
		break;

	default:
		ret = -ENOIOCTLCMD;
		break;
	}
	mutex_unlock(&s->mutex);
	unlock_kernel();
	return ret;
}

static const struct file_operations dabusb_fops =
{
	.owner =	THIS_MODULE,
	.llseek =	no_llseek,
	.read =		dabusb_read,
	.unlocked_ioctl =	dabusb_ioctl,
	.open =		dabusb_open,
	.release =	dabusb_release,
};

static char *dabusb_nodename(struct device *dev)
{
	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
}

static struct usb_class_driver dabusb_class = {
	.name =		"dabusb%d",
	.nodename =	dabusb_nodename,
	.fops =		&dabusb_fops,
	.minor_base =	DABUSB_MINOR,
};


/* --------------------------------------------------------------------- */
static int dabusb_probe (struct usb_interface *intf,
			 const struct usb_device_id *id)
{
	struct usb_device *usbdev = interface_to_usbdev(intf);
	int retval;
	pdabusb_t s;

	dbg("dabusb: probe: vendor id 0x%x, device id 0x%x ifnum:%d",
	    le16_to_cpu(usbdev->descriptor.idVendor),
	    le16_to_cpu(usbdev->descriptor.idProduct),
	    intf->altsetting->desc.bInterfaceNumber);

	/* We don't handle multiple configurations */
	if (usbdev->descriptor.bNumConfigurations != 1)
		return -ENODEV;

	if (intf->altsetting->desc.bInterfaceNumber != _DABUSB_IF &&
	    le16_to_cpu(usbdev->descriptor.idProduct) == 0x9999)
		return -ENODEV;



	s = &dabusb[intf->minor];

	mutex_lock(&s->mutex);
	s->remove_pending = 0;
	s->usbdev = usbdev;
	s->devnum = intf->minor;

	if (usb_reset_configuration (usbdev) < 0) {
		dev_err(&intf->dev, "reset_configuration failed\n");
		goto reject;
	}
	if (le16_to_cpu(usbdev->descriptor.idProduct) == 0x2131) {
		dabusb_loadmem (s, NULL);
		goto reject;
	}
	else {
		dabusb_fpga_download (s, NULL);

		if (usb_set_interface (s->usbdev, _DABUSB_IF, 0) < 0) {
			dev_err(&intf->dev, "set_interface failed\n");
			goto reject;
		}
	}
	dbg("bound to interface: %d", intf->altsetting->desc.bInterfaceNumber);
	usb_set_intfdata (intf, s);
	mutex_unlock(&s->mutex);

	retval = usb_register_dev(intf, &dabusb_class);
	if (retval) {
		usb_set_intfdata (intf, NULL);
		return -ENOMEM;
	}

	return 0;

      reject:
	mutex_unlock(&s->mutex);
	s->usbdev = NULL;
	return -ENODEV;
}

static void dabusb_disconnect (struct usb_interface *intf)
{
	wait_queue_t __wait;
	pdabusb_t s = usb_get_intfdata (intf);

	dbg("dabusb_disconnect");

	init_waitqueue_entry(&__wait, current);

	usb_set_intfdata (intf, NULL);
	if (s) {
		usb_deregister_dev (intf, &dabusb_class);
		s->remove_pending = 1;
		wake_up (&s->wait);
		add_wait_queue(&s->remove_ok, &__wait);
		set_current_state(TASK_UNINTERRUPTIBLE);
		if (s->state == _started)
			schedule();
		current->state = TASK_RUNNING;
		remove_wait_queue(&s->remove_ok, &__wait);

		s->usbdev = NULL;
		s->overruns = 0;
	}
}

static struct usb_device_id dabusb_ids [] = {
	// { USB_DEVICE(0x0547, 0x2131) },	/* An2131 chip, no boot ROM */
	{ USB_DEVICE(0x0547, 0x9999) },
	{ }						/* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, dabusb_ids);

static struct usb_driver dabusb_driver = {
	.name =		"dabusb",
	.probe =	dabusb_probe,
	.disconnect =	dabusb_disconnect,
	.id_table =	dabusb_ids,
};

/* --------------------------------------------------------------------- */

static int __init dabusb_init (void)
{
	int retval;
	unsigned u;

	/* initialize struct */
	for (u = 0; u < NRDABUSB; u++) {
		pdabusb_t s = &dabusb[u];
		memset (s, 0, sizeof (dabusb_t));
		mutex_init (&s->mutex);
		s->usbdev = NULL;
		s->total_buffer_size = buffers;
		init_waitqueue_head (&s->wait);
		init_waitqueue_head (&s->remove_ok);
		spin_lock_init (&s->lock);
		INIT_LIST_HEAD (&s->free_buff_list);
		INIT_LIST_HEAD (&s->rec_buff_list);
	}

	/* register misc device */
	retval = usb_register(&dabusb_driver);
	if (retval)
		goto out;

	dbg("dabusb_init: driver registered");

	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
	       DRIVER_DESC "\n");

out:
	return retval;
}

static void __exit dabusb_cleanup (void)
{
	dbg("dabusb_cleanup");

	usb_deregister (&dabusb_driver);
}

/* --------------------------------------------------------------------- */

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

module_param(buffers, int, 0);
MODULE_PARM_DESC (buffers, "Number of buffers (default=256)");

module_init (dabusb_init);
module_exit (dabusb_cleanup);

/* --------------------------------------------------------------------- */