}static void pl2303_update_line_status(struct usb_serial_port *port,				      unsigned char *data,				      unsigned int actual_length){	struct pl2303_private *priv = usb_get_serial_port_data(port);	unsigned long flags;	u8 status_idx = UART_STATE;	u8 length = UART_STATE + 1;	if ((le16_to_cpu(port->serial->dev->descriptor.idVendor) == SIEMENS_VENDOR_ID) &&	    (le16_to_cpu(port->serial->dev->descriptor.idProduct) == SIEMENS_PRODUCT_ID_X65 ||	     le16_to_cpu(port->serial->dev->descriptor.idProduct) == SIEMENS_PRODUCT_ID_SX1 ||	     le16_to_cpu(port->serial->dev->descriptor.idProduct) == SIEMENS_PRODUCT_ID_X75)) {		length = 1;		status_idx = 0;	}	if (actual_length < length)		goto exit;        /* Save off the uart status for others to look at */	spin_lock_irqsave(&priv->lock, flags);	priv->line_status = data[status_idx];	spin_unlock_irqrestore(&priv->lock, flags);	wake_up_interruptible (&priv->delta_msr_wait);exit:	return;}static void pl2303_read_int_callback (struct urb *urb, struct pt_regs *regs){	struct usb_serial_port *port = (struct usb_serial_port *) urb->context;	unsigned char *data = urb->transfer_buffer;	unsigned int actual_length = urb->actual_length;	int status;	dbg("%s (%d)", __FUNCTION__, port->number);	switch (urb->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__, urb->status);		return;	default:		dbg("%s - nonzero urb status received: %d", __FUNCTION__, urb->status);		goto exit;	}	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, urb->transfer_buffer);	pl2303_update_line_status(port, data, actual_length);exit:	status = usb_submit_urb (urb, GFP_ATOMIC);	if (status)		dev_err(&urb->dev->dev, "%s - usb_submit_urb failed with result %d\n",			__FUNCTION__, status);}static void pl2303_read_bulk_callback (struct urb *urb, struct pt_regs *regs){	struct usb_serial_port *port = (struct usb_serial_port *) urb->context;	struct pl2303_private *priv = usb_get_serial_port_data(port);	struct tty_struct *tty;	unsigned char *data = urb->transfer_buffer;	unsigned long flags;	int i;	int result;	u8 status;	char tty_flag;	dbg("%s - port %d", __FUNCTION__, port->number);	if (urb->status) {		dbg("%s - urb->status = %d", __FUNCTION__, urb->status);		if (!port->open_count) {			dbg("%s - port is closed, exiting.", __FUNCTION__);			return;		}		if (urb->status == -EPROTO) {			/* PL2303 mysteriously fails with -EPROTO reschedule the read */			dbg("%s - caught -EPROTO, resubmitting the urb", __FUNCTION__);			urb->status = 0;			urb->dev = port->serial->dev;			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, data);	/* get tty_flag from status */	tty_flag = TTY_NORMAL;	spin_lock_irqsave(&priv->lock, flags);	status = priv->line_status;	priv->line_status &= ~UART_STATE_TRANSIENT_MASK;	spin_unlock_irqrestore(&priv->lock, flags);	wake_up_interruptible (&priv->delta_msr_wait);	/* break takes precedence over parity, */	/* which takes precedence over framing errors */	if (status & UART_BREAK_ERROR )		tty_flag = TTY_BREAK;	else if (status & UART_PARITY_ERROR)		tty_flag = TTY_PARITY;	else if (status & UART_FRAME_ERROR)		tty_flag = TTY_FRAME;	dbg("%s - tty_flag = %d", __FUNCTION__, tty_flag);	tty = port->tty;	if (tty && urb->actual_length) {		tty_buffer_request_room(tty, urb->actual_length + 1);		/* overrun is special, not associated with a char */		if (status & UART_OVERRUN_ERROR)			tty_insert_flip_char(tty, 0, TTY_OVERRUN);		for (i = 0; i < urb->actual_length; ++i)			tty_insert_flip_char (tty, data[i], tty_flag);		tty_flip_buffer_push (tty);	}	/* Schedule the next read _if_ we are still open */	if (port->open_count) {		urb->dev = port->serial->dev;		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;}static void pl2303_write_bulk_callback (struct urb *urb, struct pt_regs *regs){	struct usb_serial_port *port = (struct usb_serial_port *) urb->context;	struct pl2303_private *priv = usb_get_serial_port_data(port);	int result;	dbg("%s - port %d", __FUNCTION__, port->number);	switch (urb->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__, urb->status);		priv->write_urb_in_use = 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__, urb->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;	}	priv->write_urb_in_use = 0;	/* send any buffered data */	pl2303_send(port);}/* * pl2303_buf_alloc * * Allocate a circular buffer and all associated memory. */static struct pl2303_buf *pl2303_buf_alloc(unsigned int size){	struct pl2303_buf *pb;	if (size == 0)		return NULL;	pb = (struct pl2303_buf *)kmalloc(sizeof(struct pl2303_buf), GFP_KERNEL);	if (pb == NULL)		return NULL;	pb->buf_buf = kmalloc(size, GFP_KERNEL);	if (pb->buf_buf == NULL) {		kfree(pb);		return NULL;	}	pb->buf_size = size;	pb->buf_get = pb->buf_put = pb->buf_buf;	return pb;}/* * pl2303_buf_free * * Free the buffer and all associated memory. */static void pl2303_buf_free(struct pl2303_buf *pb){	if (pb) {		kfree(pb->buf_buf);		kfree(pb);	}}/* * pl2303_buf_clear * * Clear out all data in the circular buffer. */static void pl2303_buf_clear(struct pl2303_buf *pb){	if (pb != NULL)		pb->buf_get = pb->buf_put;		/* equivalent to a get of all data available */}/* * pl2303_buf_data_avail * * Return the number of bytes of data available in the circular * buffer. */static unsigned int pl2303_buf_data_avail(struct pl2303_buf *pb){	if (pb != NULL)		return ((pb->buf_size + pb->buf_put - pb->buf_get) % pb->buf_size);	else		return 0;}/* * pl2303_buf_space_avail * * Return the number of bytes of space available in the circular * buffer. */static unsigned int pl2303_buf_space_avail(struct pl2303_buf *pb){	if (pb != NULL)		return ((pb->buf_size + pb->buf_get - pb->buf_put - 1) % pb->buf_size);	else		return 0;}/* * pl2303_buf_put * * Copy data data from a user buffer and put it into the circular buffer. * Restrict to the amount of space available. * * Return the number of bytes copied. */static unsigned int pl2303_buf_put(struct pl2303_buf *pb, const char *buf,	unsigned int count){	unsigned int len;	if (pb == NULL)		return 0;	len  = pl2303_buf_space_avail(pb);	if (count > len)		count = len;	if (count == 0)		return 0;	len = pb->buf_buf + pb->buf_size - pb->buf_put;	if (count > len) {		memcpy(pb->buf_put, buf, len);		memcpy(pb->buf_buf, buf+len, count - len);		pb->buf_put = pb->buf_buf + count - len;	} else {		memcpy(pb->buf_put, buf, count);		if (count < len)			pb->buf_put += count;		else /* count == len */			pb->buf_put = pb->buf_buf;	}	return count;}/* * pl2303_buf_get * * Get data from the circular buffer and copy to the given buffer. * Restrict to the amount of data available. * * Return the number of bytes copied. */static unsigned int pl2303_buf_get(struct pl2303_buf *pb, char *buf,	unsigned int count){	unsigned int len;	if (pb == NULL)		return 0;	len = pl2303_buf_data_avail(pb);	if (count > len)		count = len;	if (count == 0)		return 0;	len = pb->buf_buf + pb->buf_size - pb->buf_get;	if (count > len) {		memcpy(buf, pb->buf_get, len);		memcpy(buf+len, pb->buf_buf, count - len);		pb->buf_get = pb->buf_buf + count - len;	} else {		memcpy(buf, pb->buf_get, count);		if (count < len)			pb->buf_get += count;		else /* count == len */			pb->buf_get = pb->buf_buf;	}	return count;}static int __init pl2303_init (void){	int retval;	retval = usb_serial_register(&pl2303_device);	if (retval)		goto failed_usb_serial_register;	retval = usb_register(&pl2303_driver);	if (retval)		goto failed_usb_register;	info(DRIVER_DESC);	return 0;failed_usb_register:	usb_serial_deregister(&pl2303_device);failed_usb_serial_register:	return retval;}static void __exit pl2303_exit (void){	usb_deregister (&pl2303_driver);	usb_serial_deregister (&pl2303_device);}module_init(pl2303_init);module_exit(pl2303_exit);MODULE_DESCRIPTION(DRIVER_DESC);MODULE_LICENSE("GPL");module_param(debug, bool, S_IRUGO | S_IWUSR);MODULE_PARM_DESC(debug, "Debug enabled or not");