ftdi_sio.c

	struct ftdi_private *priv;
	struct ftdi_sio_quirk *quirk = usb_get_serial_data(port->serial);


	dbg("%s",__func__);

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

	spin_lock_init(&priv->rx_lock);
	spin_lock_init(&priv->tx_lock);
        init_waitqueue_head(&priv->delta_msr_wait);
	/* This will push the characters through immediately rather
	   than queue a task to deliver them */
	priv->flags = ASYNC_LOW_LATENCY;

	if (quirk && quirk->port_probe)
		quirk->port_probe(priv);

	/* Increase the size of read buffers */
	kfree(port->bulk_in_buffer);
	port->bulk_in_buffer = kmalloc (BUFSZ, GFP_KERNEL);
	if (!port->bulk_in_buffer) {
		kfree (priv);
		return -ENOMEM;
	}
	if (port->read_urb) {
		port->read_urb->transfer_buffer = port->bulk_in_buffer;
		port->read_urb->transfer_buffer_length = BUFSZ;
	}

	INIT_DELAYED_WORK(&priv->rx_work, ftdi_process_read);
	priv->port = port;

	/* Free port's existing write urb and transfer buffer. */
	if (port->write_urb) {
		usb_free_urb (port->write_urb);
		port->write_urb = NULL;
	}
	kfree(port->bulk_out_buffer);
	port->bulk_out_buffer = NULL;

	usb_set_serial_port_data(port, priv);

	ftdi_determine_type (port);
	create_sysfs_attrs(port);
	return 0;
}

/* Setup for the USB-UIRT device, which requires hardwired
 * baudrate (38400 gets mapped to 312500) */
/* Called from usbserial:serial_probe */
static void ftdi_USB_UIRT_setup (struct ftdi_private *priv)
{
	dbg("%s",__func__);

	priv->flags |= ASYNC_SPD_CUST;
	priv->custom_divisor = 77;
	priv->force_baud = 38400;
} /* ftdi_USB_UIRT_setup */

/* Setup for the HE-TIRA1 device, which requires hardwired
 * baudrate (38400 gets mapped to 100000) and RTS-CTS enabled.  */
static void ftdi_HE_TIRA1_setup (struct ftdi_private *priv)
{
	dbg("%s",__func__);

	priv->flags |= ASYNC_SPD_CUST;
	priv->custom_divisor = 240;
	priv->force_baud = 38400;
	priv->force_rtscts = 1;
} /* ftdi_HE_TIRA1_setup */

/*
 * First port on JTAG adaptors such as Olimex arm-usb-ocd or the FIC/OpenMoko
 * Neo1973 Debug Board is reserved for JTAG interface and can be accessed from
 * userspace using openocd.
 */
static int ftdi_jtag_probe(struct usb_serial *serial)
{
	struct usb_device *udev = serial->dev;
	struct usb_interface *interface = serial->interface;

	dbg("%s",__func__);

	if (interface == udev->actconfig->interface[0]) {
		info("Ignoring serial port reserved for JTAG");
		return -ENODEV;
	}

	return 0;
}

/*
 * The Matrix Orbital VK204-25-USB has an invalid IN endpoint.
 * We have to correct it if we want to read from it.
 */
static int ftdi_mtxorb_hack_setup(struct usb_serial *serial)
{
	struct usb_host_endpoint *ep = serial->dev->ep_in[1];
	struct usb_endpoint_descriptor *ep_desc = &ep->desc;

	if (ep->enabled && ep_desc->wMaxPacketSize == 0) {
		ep_desc->wMaxPacketSize = 0x40;
		info("Fixing invalid wMaxPacketSize on read pipe");
	}

	return 0;
}

/* ftdi_shutdown is called from usbserial:usb_serial_disconnect
 *   it is called when the usb device is disconnected
 *
 *   usbserial:usb_serial_disconnect
 *      calls __serial_close for each open of the port
 *      shutdown is called then (ie ftdi_shutdown)
 */
static void ftdi_shutdown (struct usb_serial *serial)
{
	dbg("%s", __func__);
}

static int ftdi_sio_port_remove(struct usb_serial_port *port)
{
	struct ftdi_private *priv = usb_get_serial_port_data(port);

	dbg("%s", __func__);

	remove_sysfs_attrs(port);

	/* all open ports are closed at this point
         *    (by usbserial.c:__serial_close, which calls ftdi_close)
	 */

	if (priv) {
		usb_set_serial_port_data(port, NULL);
		kfree(priv);
	}

	return 0;
}

static int  ftdi_open (struct usb_serial_port *port, struct file *filp)
{ /* ftdi_open */
	struct usb_device *dev = port->serial->dev;
	struct ftdi_private *priv = usb_get_serial_port_data(port);
	unsigned long flags;

	int result = 0;
	char buf[1]; /* Needed for the usb_control_msg I think */

	dbg("%s", __func__);

	spin_lock_irqsave(&priv->tx_lock, flags);
	priv->tx_bytes = 0;
	spin_unlock_irqrestore(&priv->tx_lock, flags);
	spin_lock_irqsave(&priv->rx_lock, flags);
	priv->rx_bytes = 0;
	spin_unlock_irqrestore(&priv->rx_lock, flags);

	if (port->tty)
		port->tty->low_latency = (priv->flags & ASYNC_LOW_LATENCY) ? 1 : 0;

	/* No error checking for this (will get errors later anyway) */
	/* See ftdi_sio.h for description of what is reset */
	usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
			FTDI_SIO_RESET_REQUEST, FTDI_SIO_RESET_REQUEST_TYPE,
			FTDI_SIO_RESET_SIO,
			priv->interface, buf, 0, WDR_TIMEOUT);

	/* Termios defaults are set by usb_serial_init. We don't change
	   port->tty->termios - this would loose speed settings, etc.
	   This is same behaviour as serial.c/rs_open() - Kuba */

	/* ftdi_set_termios  will send usb control messages */
	if (port->tty)
		ftdi_set_termios(port, port->tty->termios);

	/* FIXME: Flow control might be enabled, so it should be checked -
	   we have no control of defaults! */
	/* Turn on RTS and DTR since we are not flow controlling by default */
	set_mctrl(port, TIOCM_DTR | TIOCM_RTS);

	/* Not throttled */
	spin_lock_irqsave(&priv->rx_lock, flags);
	priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
	spin_unlock_irqrestore(&priv->rx_lock, flags);

	/* Start reading from the device */
	priv->rx_processed = 0;
	usb_fill_bulk_urb(port->read_urb, dev,
		      usb_rcvbulkpipe(dev, port->bulk_in_endpointAddress),
		      port->read_urb->transfer_buffer, port->read_urb->transfer_buffer_length,
		      ftdi_read_bulk_callback, port);
	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
	if (result)
		err("%s - failed submitting read urb, error %d", __func__, result);


	return result;
} /* ftdi_open */



/*
 * usbserial:__serial_close  only calls ftdi_close if the point is open
 *
 *   This only gets called when it is the last close
 *
 *
 */

static void ftdi_close (struct usb_serial_port *port, struct file *filp)
{ /* ftdi_close */
	unsigned int c_cflag = port->tty->termios->c_cflag;
	struct ftdi_private *priv = usb_get_serial_port_data(port);
	char buf[1];

	dbg("%s", __func__);

	mutex_lock(&port->serial->disc_mutex);
	if (c_cflag & HUPCL && !port->serial->disconnected){
		/* Disable flow control */
		if (usb_control_msg(port->serial->dev,
				    usb_sndctrlpipe(port->serial->dev, 0),
				    FTDI_SIO_SET_FLOW_CTRL_REQUEST,
				    FTDI_SIO_SET_FLOW_CTRL_REQUEST_TYPE,
				    0, priv->interface, buf, 0,
				    WDR_TIMEOUT) < 0) {
			err("error from flowcontrol urb");
		}

		/* drop RTS and DTR */
		clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
	} /* Note change no line if hupcl is off */
	mutex_unlock(&port->serial->disc_mutex);

	/* cancel any scheduled reading */
	cancel_delayed_work(&priv->rx_work);
	flush_scheduled_work();

	/* shutdown our bulk read */
	usb_kill_urb(port->read_urb);
} /* ftdi_close */



/* The SIO requires the first byte to have:
 *  B0 1
 *  B1 0
 *  B2..7 length of message excluding byte 0
 *
 * The new devices do not require this byte
 */
static int ftdi_write (struct usb_serial_port *port,
			   const unsigned char *buf, int count)
{ /* ftdi_write */
	struct ftdi_private *priv = usb_get_serial_port_data(port);
	struct urb *urb;
	unsigned char *buffer;
	int data_offset ;       /* will be 1 for the SIO and 0 otherwise */
	int status;
	int transfer_size;
	unsigned long flags;

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

	if (count == 0) {
		dbg("write request of 0 bytes");
		return 0;
	}
	spin_lock_irqsave(&priv->tx_lock, flags);
	if (priv->tx_outstanding_urbs > URB_UPPER_LIMIT) {
		spin_unlock_irqrestore(&priv->tx_lock, flags);
		dbg("%s - write limit hit\n", __func__);
		return 0;
	}
	priv->tx_outstanding_urbs++;
	spin_unlock_irqrestore(&priv->tx_lock, flags);

	data_offset = priv->write_offset;
        dbg("data_offset set to %d",data_offset);

	/* Determine total transfer size */
	transfer_size = count;
	if (data_offset > 0) {
		/* Original sio needs control bytes too... */
		transfer_size += (data_offset *
				((count + (PKTSZ - 1 - data_offset)) /
				 (PKTSZ - data_offset)));
	}

	buffer = kmalloc (transfer_size, GFP_ATOMIC);
	if (!buffer) {
		err("%s ran out of kernel memory for urb ...", __func__);
		count = -ENOMEM;
		goto error_no_buffer;
	}

	urb = usb_alloc_urb(0, GFP_ATOMIC);
	if (!urb) {
		err("%s - no more free urbs", __func__);
		count = -ENOMEM;
		goto error_no_urb;
	}

	/* Copy data */
	if (data_offset > 0) {
		/* Original sio requires control byte at start of each packet. */
		int user_pktsz = PKTSZ - data_offset;
		int todo = count;
		unsigned char *first_byte = buffer;
		const unsigned char *current_position = buf;

		while (todo > 0) {
			if (user_pktsz > todo) {
				user_pktsz = todo;
			}
			/* Write the control byte at the front of the packet*/
			*first_byte = 1 | ((user_pktsz) << 2);
			/* Copy data for packet */
			memcpy (first_byte + data_offset,
				current_position, user_pktsz);
			first_byte += user_pktsz + data_offset;
			current_position += user_pktsz;
			todo -= user_pktsz;
		}
	} else {
		/* No control byte required. */
		/* Copy in the data to send */
		memcpy (buffer, buf, count);
	}

	usb_serial_debug_data(debug, &port->dev, __func__, transfer_size, buffer);

	/* fill the buffer and send it */
	usb_fill_bulk_urb(urb, port->serial->dev,
		      usb_sndbulkpipe(port->serial->dev, port->bulk_out_endpointAddress),
		      buffer, transfer_size,
		      ftdi_write_bulk_callback, port);

	status = usb_submit_urb(urb, GFP_ATOMIC);
	if (status) {
		err("%s - failed submitting write urb, error %d", __func__, status);
		count = status;
		goto error;
	} else {
		spin_lock_irqsave(&priv->tx_lock, flags);
		priv->tx_outstanding_bytes += count;
		priv->tx_bytes += count;
		spin_unlock_irqrestore(&priv->tx_lock, flags);
	}

	/* we are done with this urb, so let the host driver
	 * really free it when it is finished with it */
	usb_free_urb(urb);

	dbg("%s write returning: %d", __func__, count);
	return count;
error:
	usb_free_urb(urb);
error_no_urb:
	kfree (buffer);
error_no_buffer:
	spin_lock_irqsave(&priv->tx_lock, flags);
	priv->tx_outstanding_urbs--;
	spin_unlock_irqrestore(&priv->tx_lock, flags);
	return count;
} /* ftdi_write */


/* This function may get called when the device is closed */

static void ftdi_write_bulk_callback (struct urb *urb)
{
	unsigned long flags;
	struct usb_serial_port *port = urb->context;
	struct ftdi_private *priv;
	int data_offset;       /* will be 1 for the SIO and 0 otherwise */
	unsigned long countback;
	int status = urb->status;

	/* free up the transfer buffer, as usb_free_urb() does not do this */
	kfree (urb->transfer_buffer);

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

	if (status) {
		dbg("nonzero write bulk status received: %d", status);
		return;
	}

	priv = usb_get_serial_port_data(port);
	if (!priv) {
		dbg("%s - bad port private data pointer - exiting", __func__);
		return;
	}
	/* account for transferred data */
	countback = urb->actual_length;
	data_offset = priv->write_offset;
	if (data_offset > 0) {
		/* Subtract the control bytes */
		countback -= (data_offset * DIV_ROUND_UP(countback, PKTSZ));
	}
	spin_lock_irqsave(&priv->tx_lock, flags);
	--priv->tx_outstanding_urbs;
	priv->tx_outstanding_bytes -= countback;
	spin_unlock_irqrestore(&priv->tx_lock, flags);

	usb_serial_port_softint(port);
} /* ftdi_write_bulk_callback */


static int ftdi_write_room( struct usb_serial_port *port )
{
	struct ftdi_private *priv = usb_get_serial_port_data(port);
	int room;
	unsigned long flags;

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

	spin_lock_irqsave(&priv->tx_lock, flags);
	if (priv->tx_outstanding_urbs < URB_UPPER_LIMIT) {
		/*
		 * We really can take anything the user throws at us
		 * but let's pick a nice big number to tell the tty
		 * layer that we have lots of free space
		 */
		room = 2048;
	} else {
		room = 0;
	}
	spin_unlock_irqrestore(&priv->tx_lock, flags);
	return room;
} /* ftdi_write_room */


static int ftdi_chars_in_buffer (struct usb_serial_port *port)
{ /* ftdi_chars_in_buffer */
	struct ftdi_private *priv = usb_get_serial_port_data(port);
	int buffered;
	unsigned long flags;

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

	spin_lock_irqsave(&priv->tx_lock, flags);
	buffered = (int)priv->tx_outstanding_bytes;
	spin_unlock_irqrestore(&priv->tx_lock, flags);
	if (buffered < 0) {
		err("%s outstanding tx bytes is negative!", __func__);
		buffered = 0;
	}
	return buffered;
} /* ftdi_chars_in_buffer */



static void ftdi_read_bulk_callback (struct urb *urb)
{ /* ftdi_read_bulk_callback */
	struct usb_serial_port *port = urb->context;
	struct tty_struct *tty;
	struct ftdi_private *priv;
	unsigned long countread;
	unsigned long flags;
	int status = urb->status;

	if (urb->number_of_packets > 0) {
		err("%s transfer_buffer_length %d actual_length %d number of packets %d",__func__,
		    urb->transfer_buffer_length, urb->actual_length, urb->number_of_packets );
		err("%s transfer_flags %x ", __func__,urb->transfer_flags );
	}

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

	if (port->open_count <= 0)
		return;

	tty = port->tty;
	if (!tty) {
		dbg("%s - bad tty pointer - exiting",__func__);
		return;
	}

	priv = usb_get_serial_port_data(port);
	if (!priv) {
		dbg("%s - bad port private data pointer - exiting", __func__);
		return;
	}

	if (urb != port->read_urb) {
		err("%s - Not my urb!", __func__);
	}

	if (status) {
		/* This will happen at close every time so it is a dbg not an err */
		dbg("(this is ok on close) nonzero read bulk status received: "
		    "%d", status);
		return;
	}

	/* count data bytes, but not status bytes */
	countread = urb->actual_length;
	countread -= 2 * DIV_ROUND_UP(countread, PKTSZ);
	spin_lock_irqsave(&priv->rx_lock, flags);
	priv->rx_bytes += countread;
	spin_unlock_irqrestore(&priv->rx_lock, flags);

	ftdi_process_read(&priv->rx_work.work);

} /* ftdi_read_bulk_callback */


static void ftdi_process_read (struct work_struct *work)
{ /* ftdi_process_read */
	struct ftdi_private *priv =
		container_of(work, struct ftdi_private, rx_work.work);
	struct usb_serial_port *port = priv->port;
	struct urb *urb;
	struct tty_struct *tty;
	char error_flag;
	unsigned char *data;

	int i;
	int result;
	int need_flip;
	int packet_offset;
	unsigned long flags;

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

	if (port->open_count <= 0)
		return;

	tty = port->tty;
	if (!tty) {
		dbg("%s - bad tty pointer - exiting",__func__);
		return;
	}

	priv = usb_get_serial_port_data(port);
	if (!priv) {
		dbg("%s - bad port private data pointer - exiting", __func__);
		return;
	}

	urb = port->read_urb;
	if (!urb) {
		dbg("%s - bad read_urb pointer - exiting", __func__);
		return;
	}

	data = urb->transfer_buffer;

	if (priv->rx_processed) {
		dbg("%s - already processed: %d bytes, %d remain", __func__,
				priv->rx_processed,
				urb->actual_length - priv->rx_processed);
	} else {
		/* The first two bytes of every read packet are status */
		if (urb->actual_length > 2) {
			usb_serial_debug_data(debug, &port->dev, __func__, urb->actual_length, data);
		} else {
			dbg("Status only: %03oo %03oo",data[0],data[1]);
		}
	}


	/* TO DO -- check for hung up line and handle appropriately: */
	/*   send hangup  */
	/* See acm.c - you do a tty_hangup  - eg tty_hangup(tty) */
	/* if CD is dropped and the line is not CLOCAL then we should hangup */

	need_flip = 0;
	for (packet_offset = priv->rx_processed; packet_offset < urb->actual_length; packet_offset += PKTSZ) {
		int length;

		/* Compare new line status to the old one, signal if different */
		/* N.B. packet may be processed more than once, but differences
		 * are only processed once.  */
		if (priv != NULL) {
			char new_status = data[packet_offset+0] & FTDI_STATUS_B0_MASK;
			if (new_status != priv->prev_status) {
				priv->diff_status |= new_status ^ priv->prev_status;
				wake_up_interruptible(&priv->delta_msr_wait);
				priv->prev_status = new_status;
			}
		}

		length = min(PKTSZ, urb->actual_length-packet_offset)-2;
		if (length < 0) {
			err("%s - bad packet length: %d", __func__, length+2);
			length = 0;
		}

		if (priv->rx_flags & THROTTLED) {
			dbg("%s - throttled", __func__);
			break;
		}
		if (tty_buffer_request_room(tty, length) < length) {
			/* break out & wait for throttling/unthrottling to happen */
			dbg("%s - receive room low", __func__);
			break;
		}

		/* Handle errors and break */
		error_flag = TTY_NORMAL;
		/* Although the device uses a bitmask and hence can have multiple */
		/* errors on a packet - the order here sets the priority the */
		/* error is returned to the tty layer  */

		if ( data[packet_offset+1] & FTDI_RS_OE ) {
			error_flag = TTY_OVERRUN;
			dbg("OVERRRUN error");
		}
		if ( data[packet_offset+1] & FTDI_RS_BI ) {
			error_flag = TTY_BREAK;
			dbg("BREAK received");
		}
		if ( data[packet_offset+1] & FTDI_RS_PE ) {
			error_flag = TTY_PARITY;
			dbg("PARITY error");
		}
		if ( data[packet_offset+1] & FTDI_RS_FE ) {
			error_flag = TTY_FRAME;
			dbg("FRAMING error");
		}
		if (length > 0) {
			for (i = 2; i < length+2; i++) {
				/* Note that the error flag is duplicated for
				   every character received since we don't know
				   which character it applied to */
				tty_insert_flip_char(tty, data[packet_offset+i], error_flag);
			}
			need_flip = 1;
		}

#ifdef NOT_CORRECT_BUT_KEEPING_IT_FOR_NOW
		/* if a parity error is detected you get status packets forever
		   until a character is sent without a parity error.
		   This doesn't work well since the application receives a never
		   ending stream of bad data - even though new data hasn't been sent.
		   Therefore I (bill) have taken this out.
		   However - this might make sense for framing errors and so on
		   so I am leaving the code in for now.
		*/
		else {
			if (error_flag != TTY_NORMAL){
				dbg("error_flag is not normal");
				/* In this case it is just status - if that is an error send a bad character */
				if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
					tty_flip_buffer_push(tty);
				}
				tty_insert_flip_char(tty, 0xff, error_flag);
				need_flip = 1;
			}
		}
#endif
	} /* "for(packet_offset=0..." */

	/* Low latency */
	if (need_flip) {
		tty_flip_buffer_push(tty);
	}

	if (packet_offset < urb->actual_length) {
		/* not completely processed - record progress */
		priv->rx_processed = packet_offset;
		dbg("%s - incomplete, %d bytes processed, %d remain",
				__func__, packet_offset,
				urb->actual_length - packet_offset);
		/* check if we were throttled while processing */
		spin_lock_irqsave(&priv->rx_lock, flags);
		if (priv->rx_flags & THROTTLED) {
			priv->rx_flags |= ACTUALLY_THROTTLED;
			spin_unlock_irqrestore(&priv->rx_lock, flags);
			dbg("%s - deferring remainder until unthrottled",
					__func__);
			return;
		}
		spin_unlock_irqrestore(&priv->rx_lock, flags);
		/* if the port is closed stop trying to read */
		if (port->open_count > 0){
			/* delay processing of remainder */
			schedule_delayed_work(&priv->rx_work, 1);
		} else {
			dbg("%s - port is closed", __func__);
		}
		return;
	}

	/* urb is completely processed */
	priv->rx_processed = 0;

	/* if the port is closed stop trying to read */
	if (port->open_count > 0){
		/* Continue trying to always read  */
		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,
			      ftdi_read_bulk_callback, port);

		result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
		if (result)
			err("%s - failed resubmitting read urb, error %d", __func__, result);
	}

	return;
} /* ftdi_process_read */


static void ftdi_break_ctl( struct usb_serial_port *port, int break_state )
{
	struct ftdi_private *priv = usb_get_serial_port_data(port);
	__u16 urb_value = 0;
	char buf[1];

	/* break_state = -1 to turn on break, and 0 to turn off break */
	/* see drivers/char/tty_io.c to see it used */
	/* last_set_data_urb_value NEVER has the break bit set in it */

	if (break_state) {
		urb_value = priv->last_set_data_urb_value | FTDI_SIO_SET_BREAK;
	} else {
		urb_value = priv->last_set_data_urb_value;
	}


	if (usb_control_msg(port->serial->dev, usb_sndctrlpipe(port->serial->dev, 0),
			    FTDI_SIO_SET_DATA_REQUEST,
			    FTDI_SIO_SET_DATA_REQUEST_TYPE,
			    urb_value , priv->interface,
			    buf, 0, WDR_TIMEOUT) < 0) {
		err("%s FAILED to enable/disable break state (state was %d)", __func__,break_state);
	}

	dbg("%s break state is %d - urb is %d", __func__,break_state, urb_value);

}


/* old_termios contains the original termios settings and tty->termios contains
 * the new setting to be used
 * WARNING: set_termios calls this with old_termios in kernel space
 */

static void ftdi_set_termios (struct usb_serial_port *port, struct ktermios *old_termios)
{ /* ftdi_termios */
	struct usb_device *dev = port->serial->dev;
	struct ftdi_private *priv = usb_get_serial_port_data(port);
	struct ktermios *termios = port->tty->termios;
	unsigned int cflag = termios->c_cflag;
	__u16 urb_value; /* will hold the new flags */
	char buf[1]; /* Perhaps I should dynamically alloc this? */

	// Added for xon/xoff support
	unsigned int iflag = termios->c_iflag;
	unsigned char vstop;
	unsigned char vstart;

	dbg("%s", __func__);

	/* Force baud rate if this device requires it, unless it is set to B0. */
	if (priv->force_baud && ((termios->c_cflag & CBAUD) != B0)) {
		dbg("%s: forcing baud rate for this device", __func__);
		tty_encode_baud_rate(port->tty, priv->force_baud,
					priv->force_baud);
	}

	/* Force RTS-CTS if this device requires it. */
	if (priv->force_rtscts) {
		dbg("%s: forcing rtscts for this device", __func__);
		termios->c_cflag |= CRTSCTS;
	}

	cflag = termios->c_cflag;

	/* FIXME -For this cut I don't care if the line is really changing or
	   not  - so just do the change regardless  - should be able to
	   compare old_termios and tty->termios */
	/* NOTE These routines can get interrupted by
	   ftdi_sio_read_bulk_callback  - need to examine what this
           means - don't see any problems yet */

	/* Set number of data bits, parity, stop bits */

	termios->c_cflag &= ~CMSPAR;

	urb_value = 0;
	urb_value |= (cflag & CSTOPB ? FTDI_SIO_SET_DATA_STOP_BITS_2 :
		      FTDI_SIO_SET_DATA_STOP_BITS_1);
	urb_value |= (cflag & PARENB ?
		      (cflag & PARODD ? FTDI_SIO_SET_DATA_PARITY_ODD :
		       FTDI_SIO_SET_DATA_PARITY_EVEN) :
		      FTDI_SIO_SET_DATA_PARITY_NONE);
	if (cflag & CSIZE) {
		switch (cflag & CSIZE) {
		case CS5: urb_value |= 5; dbg("Setting CS5"); break;
		case CS6: urb_value |= 6; dbg("Setting CS6"); break;
		case CS7: urb_value |= 7; dbg("Setting CS7"); break;
		case CS8: urb_value |= 8; dbg("Setting CS8"); break;
		default:
			err("CSIZE was set but not CS5-CS8");
		}
	}

	/* This is needed by the break command since it uses the same command - but is
	 *  or'ed with this value  */
	priv->last_set_data_urb_value = urb_value;

	if (usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
			    FTDI_SIO_SET_DATA_REQUEST,
			    FTDI_SIO_SET_DATA_REQUEST_TYPE,
			    urb_value , priv->interface,
			    buf, 0, WDR_SHORT_TIMEOUT) < 0) {
		err("%s FAILED to set databits/stopbits/parity", __func__);
	}

	/* Now do the baudrate */
	if ((cflag & CBAUD) == B0 ) {
		/* Disable flow control */
		if (usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
				    FTDI_SIO_SET_FLOW_CTRL_REQUEST,
				    FTDI_SIO_SET_FLOW_CTRL_REQUEST_TYPE,
				    0, priv->interface,
				    buf, 0, WDR_TIMEOUT) < 0) {
			err("%s error from disable flowcontrol urb", __func__);
		}
		/* Drop RTS and DTR */
		clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
	} else {
		/* set the baudrate determined before */
		if (change_speed(port)) {
			err("%s urb failed to set baudrate", __func__);
		}
		/* Ensure RTS and DTR are raised when baudrate changed from 0 */
		if (!old_termios || (old_termios->c_cflag & CBAUD) == B0) {
			set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
		}
	}

	/* Set flow control */
	/* Note device also supports DTR/CD (ugh) and Xon/Xoff in hardware */
	if (cflag & CRTSCTS) {
		dbg("%s Setting to CRTSCTS flow control", __func__);
		if (usb_control_msg(dev,
				    usb_sndctrlpipe(dev, 0),
				    FTDI_SIO_SET_FLOW_CTRL_REQUEST,
				    FTDI_SIO_SET_FLOW_CTRL_REQUEST_TYPE,
				    0 , (FTDI_SIO_RTS_CTS_HS | priv->interface),
				    buf, 0, WDR_TIMEOUT) < 0) {
			err("urb failed to set to rts/cts flow control");
		}

	} else {
		/*
		 * Xon/Xoff code
		 *
		 * Check the IXOFF status in the iflag component of the termios structure
		 * if IXOFF is not set, the pre-xon/xoff code is executed.
		*/
		if (iflag & IXOFF) {
			dbg("%s  request to enable xonxoff iflag=%04x",__func__,iflag);
			// Try to enable the XON/XOFF on the ftdi_sio
			// Set the vstart and vstop -- could have been done up above where
			// a lot of other dereferencing is done but that would be very
			// inefficient as vstart and vstop are not always needed
			vstart = termios->c_cc[VSTART];
			vstop = termios->c_cc[VSTOP];
			urb_value=(vstop << 8) | (vstart);

			if (usb_control_msg(dev,
					    usb_sndctrlpipe(dev, 0),
					    FTDI_SIO_SET_FLOW_CTRL_REQUEST,
					    FTDI_SIO_SET_FLOW_CTRL_REQUEST_TYPE,
					    urb_value , (FTDI_SIO_XON_XOFF_HS
							 | priv->interface),
					    buf, 0, WDR_TIMEOUT) < 0) {
				err("urb failed to set to xon/xoff flow control");
			}
		} else {
			/* else clause to only run if cfag ! CRTSCTS and iflag ! XOFF */
			/* CHECKME Assuming XON/XOFF handled by tty stack - not by device */
			dbg("%s Turning off hardware flow control", __func__);
			if (usb_control_msg(dev,
					    usb_sndctrlpipe(dev, 0),
					    FTDI_SIO_SET_FLOW_CTRL_REQUEST,
					    FTDI_SIO_SET_FLOW_CTRL_REQUEST_TYPE,
					    0, priv->interface,
					    buf, 0, WDR_TIMEOUT) < 0) {
				err("urb failed to clear flow control");
			}
		}

	}
	return;
} /* ftdi_termios */


static int ftdi_tiocmget (struct usb_serial_port *port, struct file *file)
{
	struct ftdi_private *priv = usb_get_serial_port_data(port);
	unsigned char buf[2];
	int ret;

	dbg("%s TIOCMGET", __func__);
	switch (priv->chip_type) {
	case SIO:
		/* Request the status from the device */
		if ((ret = usb_control_msg(port->serial->dev,
					   usb_rcvctrlpipe(port->serial->dev, 0),
					   FTDI_SIO_GET_MODEM_STATUS_REQUEST,
					   FTDI_SIO_GET_MODEM_STATUS_REQUEST_TYPE,
					   0, 0,
					   buf, 1, WDR_TIMEOUT)) < 0 ) {
			err("%s Could not get modem status of device - err: %d", __func__,
			    ret);
			return(ret);
		}
		break;
	case FT8U232AM:
	case FT232BM:
	case FT2232C:
	case FT232RL:
		/* the 8U232AM returns a two byte value (the sio is a 1 byte value) - in the same
		   format as the data returned from the in point */
		if ((ret = usb_control_msg(port->serial->dev,
					   usb_rcvctrlpipe(port->serial->dev, 0),
					   FTDI_SIO_GET_MODEM_STATUS_REQUEST,
					   FTDI_SIO_GET_MODEM_STATUS_REQUEST_TYPE,
					   0, priv->interface,
					   buf, 2, WDR_TIMEOUT)) < 0 ) {
			err("%s Could not get modem status of device - err: %d", __func__,
			    ret);
			return(ret);
		}
		break;
	default:
		return -EFAULT;
		break;
	}

	return  (buf[0] & FTDI_SIO_DSR_MASK ? TIOCM_DSR : 0) |
		(buf[0] & FTDI_SIO_CTS_MASK ? TIOCM_CTS : 0) |
		(buf[0]  & FTDI_SIO_RI_MASK  ? TIOCM_RI  : 0) |
		(buf[0]  & FTDI_SIO_RLSD_MASK ? TIOCM_CD  : 0) |
		priv->last_dtr_rts;
}

static int ftdi_tiocmset(struct usb_serial_port *port, struct file * file, unsigned int set, unsigned int clear)
{
	dbg("%s TIOCMSET", __func__);
	return update_mctrl(port, set, clear);
}


static int ftdi_ioctl (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg)
{
	struct ftdi_private *priv = usb_get_serial_port_data(port);

	dbg("%s cmd 0x%04x", __func__, cmd);

	/* Based on code from acm.c and others */
	switch (cmd) {

	case TIOCGSERIAL: /* gets serial port data */
		return get_serial_info(port, (struct serial_struct __user *) arg);

	case TIOCSSERIAL: /* sets serial port data */
		return set_serial_info(port, (struct serial_struct __user *) arg);

	/*
	 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
	 * - mask passed in arg for lines of interest
	 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
	 * Caller should use TIOCGICOUNT to see which one it was.
	 *
	 * This code is borrowed from linux/drivers/char/serial.c
	 */
	case TIOCMIWAIT:
		while (priv != NULL) {
			interruptible_sleep_on(&priv->delta_msr_wait);
			/* see if a signal did it */
			if (signal_pending(current))
				return -ERESTARTSYS;
			else {
				char diff = priv->diff_status;

				if (diff == 0) {
					return -EIO; /* no change => error */
				}

				/* Consume all events */
				priv->diff_status = 0;

				/* Return 0 if caller wanted to know about these bits */
				if ( ((arg & TIOCM_RNG) && (diff & FTDI_RS0_RI)) ||
				     ((arg & TIOCM_DSR) && (diff & FTDI_RS0_DSR)) ||