static int composite_bind(struct usb_gadget *gadget,
		struct usb_gadget_driver *gdriver)
{
	struct usb_composite_dev	*cdev;
	struct usb_composite_driver	*composite = to_cdriver(gdriver);
	int				status = -ENOMEM;

	cdev = kzalloc(sizeof *cdev, GFP_KERNEL);
	if (!cdev)
		return status;

	spin_lock_init(&cdev->lock);
	cdev->gadget = gadget;
	set_gadget_data(gadget, cdev);
	INIT_LIST_HEAD(&cdev->configs);
	INIT_LIST_HEAD(&cdev->gstrings);

	status = composite_dev_prepare(composite, cdev);
	if (status)
		goto fail;

	/* composite gadget needs to assign strings for whole device (like
	 * serial number), register function drivers, potentially update
	 * power state and consumption, etc
	 */
	status = composite->bind(cdev);
	if (status < 0)
		goto fail;

	if (cdev->use_os_string) {
		status = composite_os_desc_req_prepare(cdev, gadget->ep0);
		if (status)
			goto fail;
	}

	update_unchanged_dev_desc(&cdev->desc, composite->dev);

	/* has userspace failed to provide a serial number? */
	if (composite->needs_serial && !cdev->desc.iSerialNumber)
		WARNING(cdev, "userspace failed to provide iSerialNumber\n");

	INFO(cdev, "%s ready\n", composite->name);
	return 0;

fail:
	__composite_unbind(gadget, false);
	return status;
}