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

/*
 *      devio.c  --  User space communication with USB devices.
 *
 *      Copyright (C) 1999-2000  Thomas Sailer (sailer@ife.ee.ethz.ch)
 *
 *      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: devio.c,v 1.7 2000/02/01 17:28:48 fliegl Exp $
 *
 *  This file implements the usbdevfs/x/y files, where
 *  x is the bus number and y the device number.
 *
 *  It allows user space programs/"drivers" to communicate directly
 *  with USB devices without intervening kernel driver.
 *
 *  Revision history
 *    22.12.1999   0.1   Initial release (split from proc_usb.c)
 *    04.01.2000   0.2   Turned into its own filesystem
 */

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

#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/signal.h>
#include <linux/poll.h>
#include <linux/usb.h>
#include <asm/uaccess.h>

#include "usbdevice_fs.h"

struct async {
        struct list_head asynclist;
        struct dev_state *ps;
	struct task_struct *task;
	unsigned int signr;
	void *userbuffer;
        void *userurb;
        urb_t urb;
};

/*
 * my own sync control and bulk methods. Here to experiment
 * and because the kernel ones set the process to TASK_UNINTERRUPTIBLE.
 */

struct sync {
	wait_queue_head_t wait;
};

static void sync_completed(purb_t urb)
{
        struct sync *s = (struct sync *)urb->context;
 
        wake_up(&s->wait);	
}

static int do_sync(purb_t urb, int timeout)
{
        DECLARE_WAITQUEUE(wait, current);
	unsigned long tm;
	signed long tmdiff;
	struct sync s;
	int ret;

	tm = jiffies+timeout;
	init_waitqueue_head(&s.wait);
	add_wait_queue(&s.wait, &wait);
	urb->context = &s;
	urb->complete = sync_completed;
	set_current_state(TASK_INTERRUPTIBLE);
	if ((ret = usb_submit_urb(urb)))
		goto out;
	while (urb->status == -EINPROGRESS) {
		tmdiff = tm - jiffies;
		if (tmdiff <= 0) {
			ret = -ETIMEDOUT;
			goto out;
		}
		if (signal_pending(current)) {
			ret = -EINTR;
			goto out;
		}
		schedule_timeout(tmdiff);
	}
	ret = urb->status;
 out:
	set_current_state(TASK_RUNNING);
	usb_unlink_urb(urb);
	remove_wait_queue(&s.wait, &wait);
	return ret;
}

static int my_usb_control_msg(struct usb_device *dev, unsigned int pipe, __u8 request, __u8 requesttype,
			      __u16 value, __u16 index, void *data, __u16 size, int timeout)
{
	urb_t *urb;
	int ret;

	if (!(urb = usb_alloc_urb(0)))
		return -ENOMEM;
	if (!(urb->setup_packet = kmalloc(8, GFP_KERNEL))) {
		usb_free_urb(urb);
		return -ENOMEM;
	}
	urb->setup_packet[0] = requesttype;
	urb->setup_packet[1] = request;
	urb->setup_packet[2] = value;
	urb->setup_packet[3] = value >> 8;
	urb->setup_packet[4] = index;
	urb->setup_packet[5] = index >> 8;
	urb->setup_packet[6] = size;
	urb->setup_packet[7] = size >> 8;
	urb->dev = dev;
        urb->pipe = pipe;
        urb->transfer_buffer = data;
        urb->transfer_buffer_length = size;
	ret = do_sync(urb, timeout);
	//if (ret >= 0)
	//	ret = urb->status;
	if (ret >= 0)
		ret = urb->actual_length;
	kfree(urb->setup_packet);
	usb_free_urb(urb);
	return ret;
}

static int my_usb_bulk_msg(struct usb_device *dev, unsigned int pipe, 
			   void *data, int len, int *actual_length, int timeout)
{
	urb_t *urb;
	int ret;

	if (!(urb = usb_alloc_urb(0)))
		return -ENOMEM;
        urb->dev = dev;
        urb->pipe = pipe;
        urb->transfer_buffer = data;
        urb->transfer_buffer_length = len;
	ret = do_sync(urb, timeout);
	//if (ret >= 0)
	//	ret = urb->status;
	if (ret >= 0 && actual_length != NULL)
		*actual_length = urb->actual_length;
	usb_free_urb(urb);
	return ret;
}

static long long usbdev_lseek(struct file *file, long long offset, int orig)
{
	switch (orig) {
	case 0:
		file->f_pos = offset;
		return file->f_pos;

	case 1:
		file->f_pos += offset;
		return file->f_pos;

	case 2:
		return -EINVAL;

	default:
		return -EINVAL;
	}
}

static ssize_t usbdev_read(struct file *file, char * buf, size_t nbytes, loff_t *ppos)
{
	struct dev_state *ps = (struct dev_state *)file->private_data;
	ssize_t ret = 0;
	unsigned len;
	loff_t pos;

	pos = *ppos;
	down_read(&ps->devsem);
	if (!ps->dev)
		ret = -ENODEV;
	else if (pos < 0)
		ret = -EINVAL;
	else if (pos < sizeof(struct usb_device_descriptor)) {
		len = sizeof(struct usb_device_descriptor) - pos;
		if (len > nbytes)
			len = nbytes;
		if (copy_to_user(buf, ((char *)&ps->dev->descriptor) + pos, len))
			ret = -EFAULT;
		else {
			*ppos += len;
			buf += len;
			nbytes -= len;
			ret += len;
		}
	}
	up_read(&ps->devsem);
	return ret;
}

extern inline unsigned int ld2(unsigned int x)
{
        unsigned int r = 0;
        
        if (x >= 0x10000) {
                x >>= 16;
                r += 16;
        }
        if (x >= 0x100) {
                x >>= 8;
                r += 8;
        }
        if (x >= 0x10) {
                x >>= 4;
                r += 4;
        }
        if (x >= 4) {
                x >>= 2;
                r += 2;
        }
        if (x >= 2)
                r++;
        return r;
}

/*
 * async list handling
 */

static struct async *alloc_async(unsigned int numisoframes)
{
        unsigned int assize = sizeof(struct async) + numisoframes * sizeof(iso_packet_descriptor_t);
        struct async *as = kmalloc(assize, GFP_KERNEL);
        if (!as)
                return NULL;
        memset(as, 0, assize);
        as->urb.number_of_packets = numisoframes;
        return as;
}

static void free_async(struct async *as)
{
        if (as->urb.transfer_buffer)
                kfree(as->urb.transfer_buffer);
        kfree(as);
}

extern __inline__ void async_newpending(struct async *as)
{
        struct dev_state *ps = as->ps;
        unsigned long flags;
        
        spin_lock_irqsave(&ps->lock, flags);
        list_add_tail(&as->asynclist, &ps->async_pending);
        spin_unlock_irqrestore(&ps->lock, flags);
}

extern __inline__ void async_removepending(struct async *as)
{
        struct dev_state *ps = as->ps;
        unsigned long flags;
        
        spin_lock_irqsave(&ps->lock, flags);
        list_del(&as->asynclist);
        INIT_LIST_HEAD(&as->asynclist);
        spin_unlock_irqrestore(&ps->lock, flags);
}

extern __inline__ struct async *async_getcompleted(struct dev_state *ps)
{
        unsigned long flags;
        struct async *as = NULL;

        spin_lock_irqsave(&ps->lock, flags);
        if (!list_empty(&ps->async_completed)) {
                as = list_entry(ps->async_completed.next, struct async, asynclist);
                list_del(&as->asynclist);
                INIT_LIST_HEAD(&as->asynclist);
        }
        spin_unlock_irqrestore(&ps->lock, flags);
        return as;
}

extern __inline__ struct async *async_getpending(struct dev_state *ps, void *userurb)
{
        unsigned long flags;
        struct async *as;
        struct list_head *p;

        spin_lock_irqsave(&ps->lock, flags);
        for (p = ps->async_pending.next; p != &ps->async_pending; ) {
                as = list_entry(p, struct async, asynclist);
                p = p->next;
                if (as->userurb != userurb)
                        continue;
                list_del(&as->asynclist);
                INIT_LIST_HEAD(&as->asynclist);
                spin_unlock_irqrestore(&ps->lock, flags);
                return as;
        }
        spin_unlock_irqrestore(&ps->lock, flags);
        return NULL;
}

static void async_completed(purb_t urb)
{
        struct async *as = (struct async *)urb->context;
        struct dev_state *ps = as->ps;
	struct siginfo sinfo;

#if 1
	printk(KERN_DEBUG "usbdevfs: async_completed: status %d errcount %d actlen %d pipe 0x%x\n", 
	       urb->status, urb->error_count, urb->actual_length, urb->pipe);
#endif
        spin_lock(&ps->lock);
        list_del(&as->asynclist);
        list_add_tail(&as->asynclist, &ps->async_completed);
        spin_unlock(&ps->lock);
        wake_up(&ps->wait);
	if (as->signr) {
		sinfo.si_signo = as->signr;
		sinfo.si_errno = as->urb.status;
		sinfo.si_code = SI_ASYNCIO;
		sinfo.si_addr = as->userurb;
		send_sig_info(as->signr, &sinfo, as->task);
	}
}

static void destroy_all_async(struct dev_state *ps)
{
        struct async *as;
        unsigned long flags;

        spin_lock_irqsave(&ps->lock, flags);
        while (!list_empty(&ps->async_pending)) {
                as = list_entry(ps->async_pending.next, struct async, asynclist);
                list_del(&as->asynclist);
                INIT_LIST_HEAD(&as->asynclist);
                spin_unlock_irqrestore(&ps->lock, flags);
                /* usb_unlink_urb calls the completion handler with status == USB_ST_URB_KILLED */
                usb_unlink_urb(&as->urb);
                spin_lock_irqsave(&ps->lock, flags);
        }
        spin_unlock_irqrestore(&ps->lock, flags);
        while ((as = async_getcompleted(ps)))
                free_async(as);
}

/*
 * interface claiming
 */

static void *driver_probe(struct usb_device *dev, unsigned int intf)
{
	return NULL;
}

static void driver_disconnect(struct usb_device *dev, void *context)
{
	struct dev_state *ps = (struct dev_state *)context;

	ps->ifclaimed = 0;
}

struct usb_driver usbdevfs_driver = {
	"usbdevfs",
	driver_probe,
	driver_disconnect,
	LIST_HEAD_INIT(usbdevfs_driver.driver_list),
	NULL,
	0
};

static int claimintf(struct dev_state *ps, unsigned int intf)
{
	struct usb_device *dev = ps->dev;
	struct usb_interface *iface;
	int err;

	if (intf >= 8*sizeof(ps->ifclaimed) || !dev || intf >= dev->actconfig->bNumInterfaces)
		return -EINVAL;
	/* already claimed */
	if (test_bit(intf, &ps->ifclaimed))
		return 0;
	iface = &dev->actconfig->interface[intf];
	err = -EBUSY;
	lock_kernel();
	if (!usb_interface_claimed(iface)) {
		usb_driver_claim_interface(&usbdevfs_driver, iface, ps);
		set_bit(intf, &ps->ifclaimed);
		err = 0;
	}
	unlock_kernel();
	return err;
}

static int releaseintf(struct dev_state *ps, unsigned int intf)
{
	struct usb_device *dev;
	struct usb_interface *iface;
	int err;

	if (intf >= 8*sizeof(ps->ifclaimed))
		return -EINVAL;
	err = -EINVAL;
	lock_kernel();
	dev = ps->dev;
	if (dev && test_and_clear_bit(intf, &ps->ifclaimed)) {
		iface = &dev->actconfig->interface[intf];
		usb_driver_release_interface(&usbdevfs_driver, iface);
		err = 0;
	}
	unlock_kernel();
	return err;
}

static int checkintf(struct dev_state *ps, unsigned int intf)
{
	if (intf >= 8*sizeof(ps->ifclaimed))
		return -EINVAL;
	if (test_bit(intf, &ps->ifclaimed))
		return 0;
	/* if not yet claimed, claim it for the driver */
	printk(KERN_WARNING "usbdevfs: process %d (%s) did not claim interface %u before use\n",
	       current->pid, current->comm, intf);
	return claimintf(ps, intf);
}

static int findintfep(struct usb_device *dev, unsigned int ep)
{
	unsigned int i, j, e;
        struct usb_interface *iface;
	struct usb_interface_descriptor *alts;
	struct usb_endpoint_descriptor *endpt;

	if (ep & ~(USB_DIR_IN|0xf))
		return -EINVAL;
	for (i = 0; i < dev->actconfig->bNumInterfaces; i++) {
		iface = &dev->actconfig->interface[i];
		for (j = 0; j < iface->num_altsetting; j++) {
                        alts = &iface->altsetting[j];
			for (e = 0; e < alts->bNumEndpoints; e++) {
				endpt = &alts->endpoint[e];
				if (endpt->bEndpointAddress == ep)
					return i;
			}
		}
	}
	return -ENOENT; 
}

static int findintfif(struct usb_device *dev, unsigned int ifn)
{
	unsigned int i, j;
        struct usb_interface *iface;
	struct usb_interface_descriptor *alts;

	if (ifn & ~0xff)
		return -EINVAL;
	for (i = 0; i < dev->actconfig->bNumInterfaces; i++) {
		iface = &dev->actconfig->interface[i];
		for (j = 0; j < iface->num_altsetting; j++) {
                        alts = &iface->altsetting[j];
			if (alts->bInterfaceNumber == ifn)
				return i;
		}
	}
	return -ENOENT; 
}

/*
 * file operations
 */
static int usbdev_open(struct inode *inode, struct file *file)
{
	struct usb_device *dev;
	struct dev_state *ps;
	int ret;

	/* 
	 * no locking necessary here, as both sys_open (actually filp_open)
	 * and the hub thread have the kernel lock
	 * (still acquire the kernel lock for safety)
	 */
	lock_kernel();
	ret = -ENOENT;
	if (ITYPE(inode->i_ino) != IDEVICE)
		goto out;
	dev = inode->u.usbdev_i.p.dev;
	if (!dev)
		goto out;
	ret = -ENOMEM;
	if (!(ps = kmalloc(sizeof(struct dev_state), GFP_KERNEL)))
		goto out;
	ret = 0;
	ps->dev = dev;
	ps->file = file;
	spin_lock_init(&ps->lock);
	INIT_LIST_HEAD(&ps->async_pending);
	INIT_LIST_HEAD(&ps->async_completed);
	init_waitqueue_head(&ps->wait);
	init_rwsem(&ps->devsem);
	ps->discsignr = 0;
	ps->disctask = current;
	ps->disccontext = NULL;
	ps->ifclaimed = 0;
	wmb();
	list_add_tail(&ps->list, &dev->filelist);
	file->private_data = ps;
 out:
	unlock_kernel();
        return ret;
}

static int usbdev_release(struct inode *inode, struct file *file)
{
	struct dev_state *ps = (struct dev_state *)file->private_data;
	unsigned int i;

	lock_kernel();
	list_del(&ps->list);
	INIT_LIST_HEAD(&ps->list);
	if (ps->dev) {
		for (i = 0; ps->ifclaimed && i < 8*sizeof(ps->ifclaimed); i++)
			if (test_bit(i, &ps->ifclaimed))
				releaseintf(ps, i);
	}
	unlock_kernel();
	destroy_all_async(ps);
	kfree(ps);
        return 0;
}

static int proc_control(struct dev_state *ps, void *arg)
{
	struct usb_device *dev = ps->dev;
	struct usbdevfs_ctrltransfer ctrl;
	unsigned int tmo;
	unsigned char *tbuf;
	int i, ret;

	copy_from_user_ret(&ctrl, (void *)arg, sizeof(ctrl), -EFAULT);
	switch (ctrl.requesttype & 0x1f) {
	case USB_RECIP_ENDPOINT:
		if ((ret = findintfep(ps->dev, ctrl.index & 0xff)) < 0)
			return ret;
		if ((ret = checkintf(ps, ret)))
			return ret;
		break;

	case USB_RECIP_INTERFACE:
		if ((ret = findintfif(ps->dev, ctrl.index & 0xff)) < 0)
			return ret;
		if ((ret = checkintf(ps, ret)))
			return ret;
		break;
	}
	if (ctrl.length > PAGE_SIZE)
		return -EINVAL;
	if (!(tbuf = (unsigned char *)__get_free_page(GFP_KERNEL)))
		return -ENOMEM;
	tmo = (ctrl.timeout * HZ + 999) / 1000;
	if (ctrl.requesttype & 0x80) {
		if (ctrl.length && !access_ok(VERIFY_WRITE, ctrl.data, ctrl.length)) {
			free_page((unsigned long)tbuf);
			return -EINVAL;
		}
		i = my_usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), ctrl.request, ctrl.requesttype,
				       ctrl.value, ctrl.index, tbuf, ctrl.length, tmo);
		if ((i > 0) && ctrl.length) {
			copy_to_user_ret(ctrl.data, tbuf, ctrl.length, -EFAULT);
		}
	} else {
		if (ctrl.length) {
			copy_from_user_ret(tbuf, ctrl.data, ctrl.length, -EFAULT);
		}
		i = my_usb_control_msg(dev, usb_sndctrlpipe(dev, 0), ctrl.request, ctrl.requesttype,
				       ctrl.value, ctrl.index, tbuf, ctrl.length, tmo);
	}
	free_page((unsigned long)tbuf);
	if (i<0) {
		printk(KERN_DEBUG "usbdevfs: USBDEVFS_CONTROL failed dev %d rqt %u rq %u len %u ret %d\n", 
		       dev->devnum, ctrl.requesttype, ctrl.request, ctrl.length, i);
	}
	return i;
}

static int proc_bulk(struct dev_state *ps, void *arg)
{
	struct usb_device *dev = ps->dev;
	struct usbdevfs_bulktransfer bulk;
	unsigned int tmo, len1, pipe;
	int len2;
	unsigned char *tbuf;
	int i, ret;

	copy_from_user_ret(&bulk, (void *)arg, sizeof(bulk), -EFAULT);
	if ((ret = findintfep(ps->dev, bulk.ep)) < 0)
		return ret;
	if ((ret = checkintf(ps, ret)))
		return ret;
	if (bulk.ep & USB_DIR_IN)
		pipe = usb_rcvbulkpipe(dev, bulk.ep & 0x7f);
	else
		pipe = usb_sndbulkpipe(dev, bulk.ep & 0x7f);
	if (!usb_maxpacket(dev, pipe, !(bulk.ep & USB_DIR_IN)))
		return -EINVAL;
	len1 = bulk.len;
	if (len1 > PAGE_SIZE)
		len1 = PAGE_SIZE;
	if (!(tbuf = (unsigned char *)__get_free_page(GFP_KERNEL)))
		return -ENOMEM;
	tmo = (bulk.timeout * HZ + 999) / 1000;
	if (bulk.ep & 0x80) {
		if (len1 && !access_ok(VERIFY_WRITE, bulk.data, len1)) {
			free_page((unsigned long)tbuf);
			return -EINVAL;
		}
		i = my_usb_bulk_msg(dev, pipe, tbuf, len1, &len2, tmo);
		if (!i && len2) {
			copy_to_user_ret(bulk.data, tbuf, len2, -EFAULT);
		}
	} else {
		if (len1) {
			copy_from_user_ret(tbuf, bulk.data, len1, -EFAULT);
		}
		i = my_usb_bulk_msg(dev, pipe, tbuf, len1, &len2, tmo);
	}
	free_page((unsigned long)tbuf);
	if (i < 0) {
		printk(KERN_WARNING "usbdevfs: USBDEVFS_BULK failed dev %d ep 0x%x len %u ret %d\n", 
		       dev->devnum, bulk.ep, bulk.len, i);
		return i;
	}
	return len2;
}

static int proc_resetep(struct dev_state *ps, void *arg)
{
	unsigned int ep;
	int ret;

	get_user_ret(ep, (unsigned int *)arg, -EFAULT);
	if ((ret = findintfep(ps->dev, ep)) < 0)
		return ret;
	if ((ret = checkintf(ps, ret)))
		return ret;
	usb_settoggle(ps->dev, ep & 0xf, !(ep & USB_DIR_IN), 0);
	return 0;
}

static int proc_setintf(struct dev_state *ps, void *arg)
{
	struct usbdevfs_setinterface setintf;
	int ret;

	copy_from_user_ret(&setintf, arg, sizeof(setintf), -EFAULT);
	if ((ret = findintfif(ps->dev, setintf.interface)) < 0)
		return ret;
	if ((ret = checkintf(ps, ret)))
		return ret;
	if (usb_set_interface(ps->dev, setintf.interface, setintf.altsetting))
		return -EINVAL;
	return 0;
}

static int proc_setconfig(struct dev_state *ps, void *arg)
{
	unsigned int u;

	get_user_ret(u, (unsigned int *)arg, -EFAULT);
	if (usb_set_configuration(ps->dev, u) < 0)
		return -EINVAL;
	return 0;
}

static int proc_submiturb(struct dev_state *ps, void *arg)
{
	struct usbdevfs_urb uurb;
	struct usbdevfs_iso_packet_desc *isopkt = NULL;
	struct async *as;
	unsigned int u, totlen, isofrmlen;
	int ret;

	copy_from_user_ret(&uurb, arg, sizeof(uurb), -EFAULT);
	if (uurb.flags & ~(USBDEVFS_URB_ISO_ASAP|USBDEVFS_URB_DISABLE_SPD))
		return -EINVAL;
	if (!uurb.buffer)
		return -EINVAL;
	if (uurb.signr != 0 && (uurb.signr < SIGRTMIN || uurb.signr > SIGRTMAX))
		return -EINVAL;
	if ((ret = findintfep(ps->dev, uurb.endpoint)) < 0)
		return ret;
	if ((ret = checkintf(ps, ret)))
		return ret;
	switch(uurb.type) {
	case USBDEVFS_URB_TYPE_BULK:
		uurb.number_of_packets = 0;
		if (uurb.buffer_length > 16384)
			return -EINVAL;
		if (!access_ok((uurb.endpoint & USB_DIR_IN) ? VERIFY_WRITE : VERIFY_READ, uurb.buffer, uurb.buffer_length))
			return -EFAULT;
		break;

	case USBDEVFS_URB_TYPE_ISO:
		/* arbitrary limit */
		if (uurb.number_of_packets < 1 || uurb.number_of_packets > 128)
			return -EINVAL;
		isofrmlen = sizeof(struct usbdevfs_iso_packet_desc) * uurb.number_of_packets;
		if (!(isopkt = kmalloc(isofrmlen, GFP_KERNEL)))
			return -ENOMEM;
		if (copy_from_user(isopkt, &((struct usbdevfs_urb *)arg)->iso_frame_desc, isofrmlen)) {
			kfree(isopkt);
			return -EFAULT;
		}
		for (totlen = u = 0; u < uurb.number_of_packets; u++) {
			if (isopkt[u].length > 1023) {
				kfree(isopkt);
				return -EINVAL;
			}
			totlen += isopkt[u].length;
		}
		if (totlen > 32768) {
			kfree(isopkt);
			return -ENOMEM;
		}
		uurb.buffer_length = totlen;
		break;

	default:
		return -EINVAL;
	}
	if (!(as = alloc_async(uurb.number_of_packets))) {
		if (isopkt)
			kfree(isopkt);
		return -ENOMEM;
	}
	if (!(as->urb.transfer_buffer = kmalloc(uurb.buffer_length, GFP_KERNEL))) {
		if (isopkt)
			kfree(isopkt);
		free_async(as);
		return -ENOMEM;
	}
        as->urb.next = NULL;
        as->urb.dev = ps->dev;
        as->urb.pipe = (uurb.type << 30) | __create_pipe(ps->dev, uurb.endpoint & 0xf) | (uurb.endpoint & USB_DIR_IN);
        as->urb.transfer_flags = uurb.flags;
	as->urb.transfer_buffer_length = uurb.buffer_length;
	as->urb.start_frame = uurb.start_frame;
	as->urb.number_of_packets = uurb.number_of_packets;
        as->urb.context = as;
        as->urb.complete = async_completed;
	for (totlen = u = 0; u < uurb.number_of_packets; u++) {
		as->urb.iso_frame_desc[u].offset = totlen;
		as->urb.iso_frame_desc[u].length = isopkt[u].length;
		totlen += isopkt[u].length;
	}
	if (isopkt)
		kfree(isopkt);
	as->ps = ps;
        as->userurb = arg;
	if (uurb.endpoint & USB_DIR_IN)
		as->userbuffer = uurb.buffer;
	else
		as->userbuffer = NULL;
	as->signr = uurb.signr;
	as->task = current;
	if (!(uurb.endpoint & USB_DIR_IN)) {
		if (copy_from_user(as->urb.transfer_buffer, uurb.buffer, as->urb.transfer_buffer_length)) {
			free_async(as);
			return -EFAULT;
		}
	}
        async_newpending(as);
        if ((ret = usb_submit_urb(&as->urb))) {
		printk(KERN_DEBUG "usbdevfs: usb_submit_urb returned %d\n", ret);
                async_removepending(as);
                free_async(as);
                return ret;
        }
        return 0;
}

static int proc_unlinkurb(struct dev_state *ps, void *arg)
{
	struct async *as;

	as = async_getpending(ps, arg);
	if (!as)
		return -EINVAL;
	usb_unlink_urb(&as->urb);
	return 0;
}

static int processcompl(struct async *as)
{
	unsigned int i;

	if (as->userbuffer)
		if (copy_to_user(as->userbuffer, as->urb.transfer_buffer, as->urb.transfer_buffer_length))
			return -EFAULT;
	put_user_ret(as->urb.status, &((struct usbdevfs_urb *)as->userurb)->status, -EFAULT);
	put_user_ret(as->urb.actual_length, &((struct usbdevfs_urb *)as->userurb)->actual_length, -EFAULT);
	put_user_ret(as->urb.error_count, &((struct usbdevfs_urb *)as->userurb)->error_count, -EFAULT);
	if (!(usb_pipeisoc(as->urb.pipe)))
		return 0;
	for (i = 0; i < as->urb.number_of_packets; i++) {
		put_user_ret(as->urb.iso_frame_desc[i].actual_length, 
			     &((struct usbdevfs_urb *)as->userurb)->iso_frame_desc[i].actual_length, 
			     -EFAULT);
		put_user_ret(as->urb.iso_frame_desc[i].status, 
			     &((struct usbdevfs_urb *)as->userurb)->iso_frame_desc[i].status, 
			     -EFAULT);
	}
	return 0;
}

static int proc_reapurb(struct dev_state *ps, void *arg)
{
        DECLARE_WAITQUEUE(wait, current);
	struct async *as = NULL;
	void *addr;
	int ret;

	add_wait_queue(&ps->wait, &wait);
	while (ps->dev) {
		__set_current_state(TASK_INTERRUPTIBLE);
		if ((as = async_getcompleted(ps)))
			break;
		if (signal_pending(current))
			break;
		up_read(&ps->devsem);
		schedule();
		down_read(&ps->devsem);
	}
	remove_wait_queue(&ps->wait, &wait);
	set_current_state(TASK_RUNNING);
	if (as) {
		ret = processcompl(as);
		addr = as->userurb;
		free_async(as);
		if (ret)
			return ret;
		put_user_ret(addr, (void **)arg, -EFAULT);
		return 0;
	}
	if (signal_pending(current))
		return -EINTR;
	return -EIO;
}

static int proc_reapurbnonblock(struct dev_state *ps, void *arg)
{
	struct async *as;
	void *addr;
	int ret;

	if (!(as = async_getcompleted(ps)))
		return -EAGAIN;
	ret = processcompl(as);
	addr = as->userurb;
	free_async(as);
	if (ret)
		return ret;
	put_user_ret(addr, (void **)arg, -EFAULT);
	return 0;
}

static int proc_disconnectsignal(struct dev_state *ps, void *arg)
{
	struct usbdevfs_disconnectsignal ds;

	copy_from_user_ret(&ds, arg, sizeof(ds), -EFAULT);
	if (ds.signr != 0 && (ds.signr < SIGRTMIN || ds.signr > SIGRTMAX))
		return -EINVAL;
	ps->discsignr = ds.signr;
	ps->disccontext = ds.context;
	return 0;
}

static int proc_claiminterface(struct dev_state *ps, void *arg)
{
	unsigned int intf;
	int ret;

	get_user_ret(intf, (unsigned int *)arg, -EFAULT);
	if ((ret = findintfif(ps->dev, intf)) < 0)
		return ret;
	return claimintf(ps, ret);
}

static int proc_releaseinterface(struct dev_state *ps, void *arg)
{
	unsigned int intf;
	int ret;

	get_user_ret(intf, (unsigned int *)arg, -EFAULT);
	if ((ret = findintfif(ps->dev, intf)) < 0)
		return ret;
	return releaseintf(ps, intf);
}

static int usbdev_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
	struct dev_state *ps = (struct dev_state *)file->private_data;
	int ret = -ENOIOCTLCMD;

	if (!(file->f_mode & FMODE_WRITE))
		return -EPERM;
	down_read(&ps->devsem);
	if (!ps->dev) {
		up_read(&ps->devsem);
		return -ENODEV;
	}
	switch (cmd) {
	case USBDEVFS_CONTROL:
		ret = proc_control(ps, (void *)arg);
		if (ret >= 0)
			inode->i_mtime = CURRENT_TIME;
		break;

	case USBDEVFS_BULK:
		ret = proc_bulk(ps, (void *)arg);
		if (ret >= 0)
			inode->i_mtime = CURRENT_TIME;
		break;

	case USBDEVFS_RESETEP:
		ret = proc_resetep(ps, (void *)arg);
		if (ret >= 0)
			inode->i_mtime = CURRENT_TIME;
		break;

	case USBDEVFS_SETINTERFACE:
		ret = proc_setintf(ps, (void *)arg);
		break;

	case USBDEVFS_SETCONFIGURATION:
		ret = proc_setconfig(ps, (void *)arg);
		break;

	case USBDEVFS_SUBMITURB:
		ret = proc_submiturb(ps, (void *)arg);
		if (ret >= 0)
			inode->i_mtime = CURRENT_TIME;
		break;

	case USBDEVFS_DISCARDURB:
		ret = proc_unlinkurb(ps, (void *)arg);
		break;

	case USBDEVFS_REAPURB:
		ret = proc_reapurb(ps, (void *)arg);
		break;

	case USBDEVFS_REAPURBNDELAY:
		ret = proc_reapurbnonblock(ps, (void *)arg);
		break;

	case USBDEVFS_DISCSIGNAL:
		ret = proc_disconnectsignal(ps, (void *)arg);
		break;

	case USBDEVFS_CLAIMINTERFACE:
		ret = proc_claiminterface(ps, (void *)arg);
		break;

	case USBDEVFS_RELEASEINTERFACE:
		ret = proc_releaseinterface(ps, (void *)arg);
		break;

	}
	up_read(&ps->devsem);
	if (ret >= 0)
		inode->i_atime = CURRENT_TIME;
	return ret;
}

static unsigned int usbdev_poll(struct file *file, struct poll_table_struct *wait)
{
	struct dev_state *ps = (struct dev_state *)file->private_data;
        unsigned int mask = 0;

	poll_wait(file, &ps->wait, wait);
	if (file->f_mode & FMODE_WRITE && !list_empty(&ps->async_completed))
		mask |= POLLOUT | POLLWRNORM;
	if (!ps->dev)
		mask |= POLLERR | POLLHUP;
	return mask;
}

struct file_operations usbdevfs_device_file_operations = {
	llseek:		usbdev_lseek,
	read:		usbdev_read,
	poll:		usbdev_poll,
	ioctl:		usbdev_ioctl,
	open:		usbdev_open,
	release:	usbdev_release,
};
