static int cypress_tiocmset(struct tty_struct *tty,
			       unsigned int set, unsigned int clear)
{
	struct usb_serial_port *port = tty->driver_data;
	struct cypress_private *priv = usb_get_serial_port_data(port);
	unsigned long flags;

	spin_lock_irqsave(&priv->lock, flags);
	if (set & TIOCM_RTS)
		priv->line_control |= CONTROL_RTS;
	if (set & TIOCM_DTR)
		priv->line_control |= CONTROL_DTR;
	if (clear & TIOCM_RTS)
		priv->line_control &= ~CONTROL_RTS;
	if (clear & TIOCM_DTR)
		priv->line_control &= ~CONTROL_DTR;
	priv->cmd_ctrl = 1;
	spin_unlock_irqrestore(&priv->lock, flags);

	return cypress_write(tty, port, NULL, 0);
}

Unknown