aircable.c

linux 内核源代码

	if (num_bulk_out == 0) {
		dbg("Invalid interface, discarding");
		return -ENODEV;
	}

	return 0;
}

static int aircable_attach (struct usb_serial *serial)
{
	struct usb_serial_port *port = serial->port[0];
	struct aircable_private *priv;

	priv = kzalloc(sizeof(struct aircable_private), GFP_KERNEL);
	if (!priv){
		err("%s- kmalloc(%Zd) failed.", __FUNCTION__,
			sizeof(struct aircable_private));
		return -ENOMEM;
	}

	/* Allocation of Circular Buffers */
	priv->tx_buf = serial_buf_alloc();
	if (priv->tx_buf == NULL) {
		kfree(priv);
		return -ENOMEM;
	}

	priv->rx_buf = serial_buf_alloc();
	if (priv->rx_buf == NULL) {
		kfree(priv->tx_buf);
		kfree(priv);
		return -ENOMEM;
	}

	priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
	priv->port = port;
	INIT_WORK(&priv->rx_work, aircable_read);

	usb_set_serial_port_data(serial->port[0], priv);

	return 0;
}

static void aircable_shutdown(struct usb_serial *serial)
{

	struct usb_serial_port *port = serial->port[0];
	struct aircable_private *priv = usb_get_serial_port_data(port);

	dbg("%s", __FUNCTION__);

	if (priv) {
		serial_buf_free(priv->tx_buf);
		serial_buf_free(priv->rx_buf);
		usb_set_serial_port_data(port, NULL);
		kfree(priv);
	}
}

static int aircable_write_room(struct usb_serial_port *port)
{
	struct aircable_private *priv = usb_get_serial_port_data(port);
	return serial_buf_data_avail(priv->tx_buf);
}

static int aircable_write(struct usb_serial_port *port,
			  const unsigned char *source, int count)
{
	struct aircable_private *priv = usb_get_serial_port_data(port);
	int temp;

	dbg("%s - port %d, %d bytes", __FUNCTION__, port->number, count);

	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, source);

	if (!count){
		dbg("%s - write request of 0 bytes", __FUNCTION__);
		return count;
	}

	temp = serial_buf_put(priv->tx_buf, source, count);

	aircable_send(port);

	if (count > AIRCABLE_BUF_SIZE)
		count = AIRCABLE_BUF_SIZE;

	return count;

}

static void aircable_write_bulk_callback(struct urb *urb)
{
	struct usb_serial_port *port = urb->context;
	int status = urb->status;
	int result;

	dbg("%s - urb status: %d", __FUNCTION__ , status);

	/* This has been taken from cypress_m8.c cypress_write_int_callback */
	switch (status) {
		case 0:
			/* success */
			break;
		case -ECONNRESET:
		case -ENOENT:
		case -ESHUTDOWN:
			/* this urb is terminated, clean up */
			dbg("%s - urb shutting down with status: %d",
			    __FUNCTION__, status);
			port->write_urb_busy = 0;
			return;
		default:
			/* error in the urb, so we have to resubmit it */
			dbg("%s - Overflow in write", __FUNCTION__);
			dbg("%s - nonzero write bulk status received: %d",
			    __FUNCTION__, status);
			port->write_urb->transfer_buffer_length = 1;
			port->write_urb->dev = port->serial->dev;
			result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
			if (result)
				dev_err(&urb->dev->dev,
					"%s - failed resubmitting write urb, error %d\n",
					__FUNCTION__, result);
			else
				return;
	}

	port->write_urb_busy = 0;

	aircable_send(port);
}

static void aircable_read_bulk_callback(struct urb *urb)
{
	struct usb_serial_port *port = urb->context;
	struct aircable_private *priv = usb_get_serial_port_data(port);
	struct tty_struct *tty;
	unsigned long no_packages, remaining, package_length, i;
	int result, shift = 0;
	unsigned char *temp;
	int status = urb->status;

	dbg("%s - port %d", __FUNCTION__, port->number);

	if (status) {
		dbg("%s - urb status = %d", __FUNCTION__, status);
		if (!port->open_count) {
			dbg("%s - port is closed, exiting.", __FUNCTION__);
			return;
		}
		if (status == -EPROTO) {
			dbg("%s - caught -EPROTO, resubmitting the urb",
			    __FUNCTION__);
			usb_fill_bulk_urb(port->read_urb, port->serial->dev,
					  usb_rcvbulkpipe(port->serial->dev,
					  		  port->bulk_in_endpointAddress),
					  port->read_urb->transfer_buffer,
					  port->read_urb->transfer_buffer_length,
					  aircable_read_bulk_callback, port);

			result = usb_submit_urb(urb, GFP_ATOMIC);
			if (result)
				dev_err(&urb->dev->dev,
					"%s - failed resubmitting read urb, error %d\n",
					__FUNCTION__, result);
			return;
		}
		dbg("%s - unable to handle the error, exiting.", __FUNCTION__);
		return;
	}

	usb_serial_debug_data(debug, &port->dev, __FUNCTION__,
				urb->actual_length,urb->transfer_buffer);

	tty = port->tty;
	if (tty && urb->actual_length) {
		if (urb->actual_length <= 2) {
			/* This is an incomplete package */
			serial_buf_put(priv->rx_buf, urb->transfer_buffer,
				       urb->actual_length);
		} else {
			temp = urb->transfer_buffer;
			if (temp[0] == RX_HEADER_0)
				shift = HCI_HEADER_LENGTH;

			remaining = urb->actual_length;
			no_packages = urb->actual_length / (HCI_COMPLETE_FRAME);

			if (urb->actual_length % HCI_COMPLETE_FRAME != 0)
				no_packages+=1;

			for (i = 0; i < no_packages ;i++) {
				if (remaining > (HCI_COMPLETE_FRAME))
					package_length = HCI_COMPLETE_FRAME;
				else
					package_length = remaining;
				remaining -= package_length;

				serial_buf_put(priv->rx_buf,
					urb->transfer_buffer + shift +
					(HCI_COMPLETE_FRAME) * (i),
					package_length - shift);
			}
		}
		aircable_read(&priv->rx_work);
	}

	/* Schedule the next read _if_ we are still open */
	if (port->open_count) {
		usb_fill_bulk_urb(port->read_urb, port->serial->dev,
				  usb_rcvbulkpipe(port->serial->dev,
				  		  port->bulk_in_endpointAddress),
				  port->read_urb->transfer_buffer,
				  port->read_urb->transfer_buffer_length,
				  aircable_read_bulk_callback, port);

		result = usb_submit_urb(urb, GFP_ATOMIC);
		if (result)
			dev_err(&urb->dev->dev,
				"%s - failed resubmitting read urb, error %d\n",
				__FUNCTION__, result);
	}

	return;
}

/* Based on ftdi_sio.c throttle */
static void aircable_throttle(struct usb_serial_port *port)
{
	struct aircable_private *priv = usb_get_serial_port_data(port);
	unsigned long flags;

	dbg("%s - port %d", __FUNCTION__, port->number);

	spin_lock_irqsave(&priv->rx_lock, flags);
	priv->rx_flags |= THROTTLED;
	spin_unlock_irqrestore(&priv->rx_lock, flags);
}

/* Based on ftdi_sio.c unthrottle */
static void aircable_unthrottle(struct usb_serial_port *port)
{
	struct aircable_private *priv = usb_get_serial_port_data(port);
	int actually_throttled;
	unsigned long flags;

	dbg("%s - port %d", __FUNCTION__, port->number);

	spin_lock_irqsave(&priv->rx_lock, flags);
	actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
	priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
	spin_unlock_irqrestore(&priv->rx_lock, flags);

	if (actually_throttled)
		schedule_work(&priv->rx_work);
}

static struct usb_driver aircable_driver = {
	.name =		"aircable",
	.probe =	usb_serial_probe,
	.disconnect =	usb_serial_disconnect,
	.id_table =	id_table,
	.no_dynamic_id =	1,
};

static struct usb_serial_driver aircable_device = {
	.driver = {
		.owner =	THIS_MODULE,
		.name =		"aircable",
	},
	.usb_driver = 		&aircable_driver,
	.id_table = 		id_table,
	.num_ports =		1,
	.attach =		aircable_attach,
	.probe =		aircable_probe,
	.shutdown =		aircable_shutdown,
	.write =		aircable_write,
	.write_room =		aircable_write_room,
	.write_bulk_callback =	aircable_write_bulk_callback,
	.read_bulk_callback =	aircable_read_bulk_callback,
	.throttle =		aircable_throttle,
	.unthrottle =		aircable_unthrottle,
};

static int __init aircable_init (void)
{
	int retval;
	retval = usb_serial_register(&aircable_device);
	if (retval)
		goto failed_serial_register;
	retval = usb_register(&aircable_driver);
	if (retval)
		goto failed_usb_register;
	return 0;

failed_serial_register:
	usb_serial_deregister(&aircable_device);
failed_usb_register:
	return retval;
}

static void __exit aircable_exit (void)
{
	usb_deregister(&aircable_driver);
	usb_serial_deregister(&aircable_device);
}

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

module_init(aircable_init);
module_exit(aircable_exit);

module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");