devio.c

linux core 函数例程

		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; 
}

extern struct list_head usb_driver_list;

#if 0
static int finddriver(struct usb_driver **driver, char *name)
{
	struct list_head *tmp;

	tmp = usb_driver_list.next;
	while (tmp != &usb_driver_list) {
		struct usb_driver *d = list_entry(tmp, struct usb_driver,
							driver_list);

		if (!strcmp(d->name, name)) {
			*driver = d;
			return 0;
		}

		tmp = tmp->next;
	}

	return -EINVAL;
}
#endif

static int check_ctrlrecip(struct dev_state *ps, unsigned int requesttype, unsigned int index)
{
	int ret;

	if (USB_TYPE_VENDOR == (USB_TYPE_MASK & requesttype))
		return 0;

	switch (requesttype & USB_RECIP_MASK) {
	case USB_RECIP_ENDPOINT:
		if ((ret = findintfep(ps->dev, index & 0xff)) < 0)
			return ret;
		if ((ret = checkintf(ps, ret)))
			return ret;
		break;

	case USB_RECIP_INTERFACE:
		if ((ret = findintfif(ps->dev, index & 0xff)) < 0)
			return ret;
		if ((ret = checkintf(ps, ret)))
			return ret;
		break;
	}
	return 0;
}

/*
 * 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;
	dev = inode->u.generic_ip;
	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;

	if (copy_from_user(&ctrl, (void *)arg, sizeof(ctrl)))
		return -EFAULT;
	if ((ret = check_ctrlrecip(ps, ctrl.bRequestType, ctrl.wIndex)))
		return ret;
	if (ctrl.wLength > PAGE_SIZE)
		return -EINVAL;
	if (!(tbuf = (unsigned char *)__get_free_page(GFP_KERNEL)))
		return -ENOMEM;
	tmo = (ctrl.timeout * HZ + 999) / 1000;
	if (ctrl.bRequestType & 0x80) {
		if (ctrl.wLength && !access_ok(VERIFY_WRITE, ctrl.data, ctrl.wLength)) {
			free_page((unsigned long)tbuf);
			return -EINVAL;
		}
		i = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), ctrl.bRequest, ctrl.bRequestType,
				       ctrl.wValue, ctrl.wIndex, tbuf, ctrl.wLength, tmo);
		if ((i > 0) && ctrl.wLength) {
			if (copy_to_user(ctrl.data, tbuf, ctrl.wLength)) {
				free_page((unsigned long)tbuf);
				return -EFAULT;
			}
		}
	} else {
		if (ctrl.wLength) {
			if (copy_from_user(tbuf, ctrl.data, ctrl.wLength)) {
				free_page((unsigned long)tbuf);
				return -EFAULT;
			}
		}
		i = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), ctrl.bRequest, ctrl.bRequestType,
				       ctrl.wValue, ctrl.wIndex, tbuf, ctrl.wLength, tmo);
	}
	free_page((unsigned long)tbuf);
	if (i<0) {
		printk(KERN_DEBUG "usbfs: USBDEVFS_CONTROL failed dev %d rqt %u rq %u len %u ret %d\n", 
		       dev->devnum, ctrl.bRequestType, ctrl.bRequest, ctrl.wLength, 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;

	if (copy_from_user(&bulk, (void *)arg, sizeof(bulk)))
		return -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 (!(tbuf = kmalloc(len1, GFP_KERNEL)))
		return -ENOMEM;
	tmo = (bulk.timeout * HZ + 999) / 1000;
	if (bulk.ep & 0x80) {
		if (len1 && !access_ok(VERIFY_WRITE, bulk.data, len1)) {
			kfree(tbuf);
			return -EINVAL;
		}
		i = usb_bulk_msg(dev, pipe, tbuf, len1, &len2, tmo);
		if (!i && len2) {
			if (copy_to_user(bulk.data, tbuf, len2)) {
				kfree(tbuf);
				return -EFAULT;
			}
		}
	} else {
		if (len1) {
			if (copy_from_user(tbuf, bulk.data, len1)) {
				kfree(tbuf);
				return -EFAULT;
			}
		}
		i = usb_bulk_msg(dev, pipe, tbuf, len1, &len2, tmo);
	}
	kfree(tbuf);
	if (i < 0) {
		printk(KERN_WARNING "usbfs: 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;

	if (get_user(ep, (unsigned int *)arg))
		return -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_clearhalt(struct dev_state *ps, void *arg)
{
	unsigned int ep;
	int pipe;
	int ret;

	if (get_user(ep, (unsigned int *)arg))
		return -EFAULT;
	if ((ret = findintfep(ps->dev, ep)) < 0)
		return ret;
	if ((ret = checkintf(ps, ret)))
		return ret;
	if (ep & USB_DIR_IN)
                pipe = usb_rcvbulkpipe(ps->dev, ep & 0x7f);
        else
                pipe = usb_sndbulkpipe(ps->dev, ep & 0x7f);

	return usb_clear_halt(ps->dev, pipe);
}
		

static int proc_getdriver(struct dev_state *ps, void *arg)
{
	struct usbdevfs_getdriver gd;
	struct usb_interface *interface;
	int ret;

	if (copy_from_user(&gd, arg, sizeof(gd)))
		return -EFAULT;
	if ((ret = findintfif(ps->dev, gd.interface)) < 0)
		return ret;
	interface = usb_ifnum_to_if(ps->dev, gd.interface);
	if (!interface)
		return -EINVAL;
	if (!interface->driver)
		return -ENODATA;
	strcpy(gd.driver, interface->driver->name);
	if (copy_to_user(arg, &gd, sizeof(gd)))
		return -EFAULT;
	return 0;
}

static int proc_connectinfo(struct dev_state *ps, void *arg)
{
	struct usbdevfs_connectinfo ci;

	ci.devnum = ps->dev->devnum;
	ci.slow = ps->dev->speed == USB_SPEED_LOW;
	if (copy_to_user(arg, &ci, sizeof(ci)))
		return -EFAULT;
	return 0;
}

static int proc_resetdevice(struct dev_state *ps)
{
	int i, ret;

	ret = usb_reset_device(ps->dev);
	if (ret < 0)
		return ret;

	for (i = 0; i < ps->dev->actconfig->bNumInterfaces; i++) {
		struct usb_interface *intf = &ps->dev->actconfig->interface[i];

		/* Don't simulate interfaces we've claimed */
		if (test_bit(i, &ps->ifclaimed))
			continue;

		if (intf->driver) {
			const struct usb_device_id *id;
			down(&intf->driver->serialize);
			intf->driver->disconnect(ps->dev, intf->private_data);
			id = usb_match_id(ps->dev,intf,intf->driver->id_table);
			intf->driver->probe(ps->dev, i, id);
			up(&intf->driver->serialize);
		}
	}

	return 0;
}

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

	if (copy_from_user(&setintf, arg, sizeof(setintf)))
		return -EFAULT;
	if ((ret = findintfif(ps->dev, setintf.interface)) < 0)
		return ret;
	interface = usb_ifnum_to_if(ps->dev, setintf.interface);
	if (!interface)
		return -EINVAL;
	if (interface->driver) {
		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;

	if (get_user(u, (unsigned int *)arg))
		return -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 usb_endpoint_descriptor *ep_desc;
	struct async *as;
	struct usb_ctrlrequest *dr = NULL;
	unsigned int u, totlen, isofrmlen;
	int ret;

	if (copy_from_user(&uurb, arg, sizeof(uurb)))
		return -EFAULT;
	if (uurb.flags & ~(USBDEVFS_URB_ISO_ASAP|USBDEVFS_URB_DISABLE_SPD|USBDEVFS_URB_QUEUE_BULK|
			   USB_NO_FSBR|USB_ZERO_PACKET))
		return -EINVAL;
	if (!uurb.buffer)
		return -EINVAL;
	if (uurb.signr != 0 && (uurb.signr < SIGRTMIN || uurb.signr > SIGRTMAX))
		return -EINVAL;
	if (!(uurb.type == USBDEVFS_URB_TYPE_CONTROL && (uurb.endpoint & ~USB_ENDPOINT_DIR_MASK) == 0)) {
		if ((ret = findintfep(ps->dev, uurb.endpoint)) < 0)
			return ret;
		if ((ret = checkintf(ps, ret)))
			return ret;
	}
	switch(uurb.type) {
	case USBDEVFS_URB_TYPE_CONTROL:
		if ((uurb.endpoint & ~USB_ENDPOINT_DIR_MASK) != 0) {
			if (!(ep_desc = usb_epnum_to_ep_desc(ps->dev, uurb.endpoint)))
				return -ENOENT;
			if ((ep_desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_CONTROL)
				return -EINVAL;
		}
		/* min 8 byte setup packet, max arbitrary */
		if (uurb.buffer_length < 8 || uurb.buffer_length > PAGE_SIZE)
			return -EINVAL;
		if (!(dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL)))
			return -ENOMEM;
		if (copy_from_user(dr, (unsigned char*)uurb.buffer, 8)) {
			kfree(dr);
			return -EFAULT;
		}
		if (uurb.buffer_length < (le16_to_cpup(&dr->wLength) + 8)) {
			kfree(dr);
			return -EINVAL;
		}
		if ((ret = check_ctrlrecip(ps, dr->bRequestType, le16_to_cpup(&dr->wIndex)))) {
			kfree(dr);
			return ret;
		}
		uurb.endpoint = (uurb.endpoint & ~USB_ENDPOINT_DIR_MASK) | (dr->bRequestType & USB_ENDPOINT_DIR_MASK);
		uurb.number_of_packets = 0;
		uurb.buffer_length = le16_to_cpup(&dr->wLength);
		uurb.buffer += 8;
		if (!access_ok((uurb.endpoint & USB_DIR_IN) ?  VERIFY_WRITE : VERIFY_READ, uurb.buffer, uurb.buffer_length)) {
			kfree(dr);
			return -EFAULT;
		}
		break;

	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;