ftdi_sio.c

	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", __FUNCTION__);
		}
		/* 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", __FUNCTION__);
		}
		/* 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", __FUNCTION__);
		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",__FUNCTION__,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=port->tty->termios->c_cc[VSTART];
			vstop=port->tty->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", __FUNCTION__);
			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", __FUNCTION__);
	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", __FUNCTION__,
			    ret);
			return(ret);
		}
		break;
	case FT8U232AM:
	case FT232BM:
	case FT2232C:
		/* 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", __FUNCTION__,
			    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", __FUNCTION__);
	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", __FUNCTION__, 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)) ||
				     ((arg & TIOCM_CD)  && (diff & FTDI_RS0_RLSD)) ||
				     ((arg & TIOCM_CTS) && (diff & FTDI_RS0_CTS)) ) {
					return 0;
				}
				/*
				 * Otherwise caller can't care less about what happened,
				 * and so we continue to wait for more events.
				 */
			}
		}
		return(0);
		break;
	default:
		break;

	}


	/* This is not necessarily an error - turns out the higher layers will do
	 *  some ioctls itself (see comment above)
	 */
	dbg("%s arg not supported - it was 0x%04x - check /usr/include/asm/ioctls.h", __FUNCTION__, cmd);

	return(-ENOIOCTLCMD);
} /* ftdi_ioctl */


static void ftdi_throttle (struct usb_serial_port *port)
{
	struct ftdi_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);
}


static void ftdi_unthrottle (struct usb_serial_port *port)
{
	struct ftdi_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_delayed_work(&priv->rx_work, 0);
}

static int __init ftdi_init (void)
{
	int retval;

	dbg("%s", __FUNCTION__);
	if (vendor > 0 && product > 0) {
		/* Add user specified VID/PID to reserved element of table. */
		int i;
		for (i = 0; id_table_combined[i].idVendor; i++)
			;
		id_table_combined[i].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
		id_table_combined[i].idVendor = vendor;
		id_table_combined[i].idProduct = product;
	}
	retval = usb_serial_register(&ftdi_sio_device);
	if (retval)
		goto failed_sio_register;
	retval = usb_register(&ftdi_driver);
	if (retval)
		goto failed_usb_register;

	info(DRIVER_VERSION ":" DRIVER_DESC);
	return 0;
failed_usb_register:
	usb_serial_deregister(&ftdi_sio_device);
failed_sio_register:
	return retval;
}


static void __exit ftdi_exit (void)
{

	dbg("%s", __FUNCTION__);

	usb_deregister (&ftdi_driver);
	usb_serial_deregister (&ftdi_sio_device);

}


module_init(ftdi_init);
module_exit(ftdi_exit);

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

module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");
module_param(vendor, ushort, 0);
MODULE_PARM_DESC(vendor, "User specified vendor ID (default="
		__MODULE_STRING(FTDI_VID)")");
module_param(product, ushort, 0);
MODULE_PARM_DESC(vendor, "User specified product ID");