Staging: Add serqt_usb2, a rewrite of serqt_usb for the usb-serial layer

This is the serqt_usb driver rewritten to use usb-serial.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 1674 insertions, 0 deletions

diff --git a/drivers/staging/serqt_usb2/Kconfig b/drivers/staging/serqt_usb2/Kconfig
new file mode 100644
index 0000000..f4fed40
--- /dev/null
+++ b/drivers/staging/serqt_usb2/Kconfig
@@ -0,0 +1,9 @@
+config USB_SERIAL_QUATECH2
+	tristate "USB Quatech ESU-100 8 Port Serial Driver"
+	depends on USB_SERIAL
+	help
+	  Say Y here if you want to use the Quatech ESU-100 8 port usb to
+	  serial adapter.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called serqt_usb2.
diff --git a/drivers/staging/serqt_usb2/Makefile b/drivers/staging/serqt_usb2/Makefile
new file mode 100644
index 0000000..2157861
--- /dev/null
+++ b/drivers/staging/serqt_usb2/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_USB_SERIAL_QUATECH2)		+= serqt_usb2.o
diff --git a/drivers/staging/serqt_usb2/serqt_usb2.c b/drivers/staging/serqt_usb2/serqt_usb2.c
new file mode 100644
index 0000000..581232b
--- /dev/null
+++ b/drivers/staging/serqt_usb2/serqt_usb2.c
@@ -0,0 +1,1664 @@
+/*
+ * This code was developed for the Quatech USB line for linux, it used
+ * much of the code developed by Greg Kroah-Hartman for USB serial devices
+ *
+ */
+
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/module.h>
+#include <linux/serial.h>
+#include <linux/usb.h>
+#include <linux/usb/serial.h>
+#include <linux/uaccess.h>
+
+static int debug;
+
+/* Version Information */
+#define DRIVER_VERSION "v2.14"
+#define DRIVER_AUTHOR "Tim Gobeli, Quatech, Inc"
+#define DRIVER_DESC "Quatech USB to Serial Driver"
+
+#define	USB_VENDOR_ID_QUATECH			0x061d	/* Quatech VID */
+#define QUATECH_SSU100	0xC020	/* SSU100 */
+#define QUATECH_SSU200	0xC030	/* SSU200 */
+#define QUATECH_DSU100	0xC040	/* DSU100 */
+#define QUATECH_DSU200	0xC050	/* DSU200 */
+#define QUATECH_QSU100	0xC060	/* QSU100 */
+#define QUATECH_QSU200	0xC070	/* QSU200 */
+#define QUATECH_ESU100A	0xC080	/* ESU100A */
+#define QUATECH_ESU100B	0xC081	/* ESU100B */
+#define QUATECH_ESU200A	0xC0A0	/* ESU200A */
+#define QUATECH_ESU200B	0xC0A1	/* ESU200B */
+#define QUATECH_HSU100A	0xC090	/* HSU100A */
+#define QUATECH_HSU100B	0xC091	/* HSU100B */
+#define QUATECH_HSU100C	0xC092	/* HSU100C */
+#define QUATECH_HSU100D	0xC093	/* HSU100D */
+#define QUATECH_HSU200A	0xC0B0	/* HSU200A */
+#define QUATECH_HSU200B	0xC0B1	/* HSU200B */
+#define QUATECH_HSU200C	0xC0B2	/* HSU200C */
+#define QUATECH_HSU200D	0xC0B3	/* HSU200D */
+#define QUATECH_SSU100_2  0xC120	/* SSU100_2 */
+#define QUATECH_DSU100_2  0xC140	/* DSU100_2 */
+#define QUATECH_DSU400_2  0xC150	/* DSU400_2 */
+#define QUATECH_QSU100_2  0xC160	/* QSU100_2 */
+#define QUATECH_QSU400_2  0xC170	/* QSU400_2 */
+#define QUATECH_ESU400_2  0xC180	/* ESU400_2 */
+#define QUATECH_ESU100_2  0xC1A0	/* ESU100_2 */
+
+#define QT_SET_GET_DEVICE           0xc2
+#define QT_OPEN_CLOSE_CHANNEL       0xca
+#define QT_GET_SET_PREBUF_TRIG_LVL  0xcc
+#define QT_SET_ATF                  0xcd
+#define QT_GET_SET_REGISTER         0xc0
+#define QT_GET_SET_UART             0xc1
+#define QT_HW_FLOW_CONTROL_MASK     0xc5
+#define QT_SW_FLOW_CONTROL_MASK     0xc6
+#define QT_SW_FLOW_CONTROL_DISABLE  0xc7
+#define QT_BREAK_CONTROL            0xc8
+
+#define USBD_TRANSFER_DIRECTION_IN    0xc0
+#define USBD_TRANSFER_DIRECTION_OUT   0x40
+
+#define  MAX_BAUD_RATE              460800
+#define  MAX_BAUD_REMAINDER         4608
+
+#define  DIV_LATCH_LS               0x00
+#define  XMT_HOLD_REGISTER          0x00
+#define  XVR_BUFFER_REGISTER        0x00
+#define  DIV_LATCH_MS               0x01
+#define  FIFO_CONTROL_REGISTER      0x02
+#define  LINE_CONTROL_REGISTER      0x03
+#define  MODEM_CONTROL_REGISTER     0x04
+#define  LINE_STATUS_REGISTER       0x05
+#define  MODEM_STATUS_REGISTER      0x06
+
+#define  SERIAL_MCR_DTR             0x01
+#define  SERIAL_MCR_RTS             0x02
+#define  SERIAL_MCR_LOOP            0x10
+
+#define  SERIAL_MSR_CTS             0x10
+#define  SERIAL_MSR_CD              0x80
+#define  SERIAL_MSR_RI              0x40
+#define  SERIAL_MSR_DSR             0x20
+#define  SERIAL_MSR_MASK            0xf0
+
+#define  SERIAL_8_DATA              0x03
+#define  SERIAL_7_DATA              0x02
+#define  SERIAL_6_DATA              0x01
+#define  SERIAL_5_DATA              0x00
+
+#define  SERIAL_ODD_PARITY          0X08
+#define  SERIAL_EVEN_PARITY         0X18
+#define  SERIAL_TWO_STOPB           0x04
+#define  SERIAL_ONE_STOPB           0x00
+
+#define DEFAULT_DIVISOR  0x30	/* gives 9600 baud rate */
+#define DEFAULT_LCR SERIAL_8_DATA	/* 8, none , 1 */
+
+#define FULLPWRBIT          0x00000080
+#define NEXT_BOARD_POWER_BIT        0x00000004
+
+#define SERIAL_LSR_OE       0x02
+#define SERIAL_LSR_PE       0x04
+#define SERIAL_LSR_FE       0x08
+#define SERIAL_LSR_BI       0x10
+
+#define  SERIAL_MSR_CTS             0x10
+#define  SERIAL_MSR_CD              0x80
+#define  SERIAL_MSR_RI              0x40
+#define  SERIAL_MSR_DSR             0x20
+#define  SERIAL_MSR_MASK            0xf0
+
+#define PREFUFF_LEVEL_CONSERVATIVE  128
+#define ATC_DISABLED                0x0
+
+#define RR_BITS             0x03	/* for clearing clock bits */
+#define DUPMODE_BITS        0xc0
+#define CLKS_X4             0x02
+
+#define LOOPMODE_BITS       0x41	/* LOOP1 = b6, LOOP0 = b0 (PORT B) */
+#define ALL_LOOPBACK        0x01
+#define MODEM_CTRL          0x40
+#define RS232_MODE          0x00
+
+static struct usb_device_id serqt_id_table[] = {
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_SSU100)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_SSU200)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_DSU100)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_DSU200)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_QSU100)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_QSU200)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU100A)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU100B)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU200A)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU200B)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_HSU100A)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_HSU100B)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_HSU100C)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_HSU100D)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_HSU200A)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_HSU200B)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_HSU200C)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_HSU200D)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_SSU100_2)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_DSU100_2)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_DSU400_2)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_QSU100_2)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_QSU400_2)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU400_2)},
+	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU100_2)},
+	{}			/* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, serqt_id_table);
+
+struct qt_get_device_data {
+	__u8 porta;
+	__u8 portb;
+	__u8 portc;
+};
+
+struct qt_open_channel_data {
+	__u8 line_status;
+	__u8 modem_status;
+};
+
+struct quatech_port {
+	int port_num;		/* number of the port */
+	struct urb *write_urb;	/* write URB for this port */
+	struct urb *read_urb;	/* read URB for this port */
+	struct urb *int_urb;
+
+	__u8 shadowLCR;		/* last LCR value received */
+	__u8 shadowMCR;		/* last MCR value received */
+	__u8 shadowMSR;		/* last MSR value received */
+	__u8 shadowLSR;		/* last LSR value received */
+	char open_ports;
+
+	/* Used for TIOCMIWAIT */
+	wait_queue_head_t msr_wait;
+	char prev_status, diff_status;
+
+	wait_queue_head_t wait;
+
+	struct async_icount icount;
+
+	struct usb_serial_port *port;	/* owner of this object */
+	struct qt_get_device_data DeviceData;
+	spinlock_t lock;
+	bool read_urb_busy;
+	int RxHolding;
+	int ReadBulkStopped;
+	char closePending;
+};
+
+static struct usb_driver serqt_usb_driver = {
+	.name = "quatech-usb-serial",
+	.probe = usb_serial_probe,
+	.disconnect = usb_serial_disconnect,
+	.id_table = serqt_id_table,
+	.no_dynamic_id = 1,
+};
+
+static int port_paranoia_check(struct usb_serial_port *port,
+			       const char *function)
+{
+	if (!port) {
+		dbg("%s - port == NULL", function);
+		return -1;
+	}
+	if (!port->serial) {
+		dbg("%s - port->serial == NULL\n", function);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int serial_paranoia_check(struct usb_serial *serial,
+				 const char *function)
+{
+	if (!serial) {
+		dbg("%s - serial == NULL\n", function);
+		return -1;
+	}
+
+	if (!serial->type) {
+		dbg("%s - serial->type == NULL!", function);
+		return -1;
+	}
+
+	return 0;
+}
+
+static inline struct quatech_port *qt_get_port_private(struct usb_serial_port
+						       *port)
+{
+	return (struct quatech_port *)usb_get_serial_port_data(port);
+}
+
+static inline void qt_set_port_private(struct usb_serial_port *port,
+				       struct quatech_port *data)
+{
+	usb_set_serial_port_data(port, (void *)data);
+}
+
+static struct usb_serial *get_usb_serial(struct usb_serial_port *port,
+					 const char *function)
+{
+	/* if no port was specified, or it fails a paranoia check */
+	if (!port ||
+	    port_paranoia_check(port, function) ||
+	    serial_paranoia_check(port->serial, function)) {
+		/*
+		 * then say that we dont have a valid usb_serial thing,
+		 * which will end up genrating -ENODEV return values
+		 */
+		return NULL;
+	}
+
+	return port->serial;
+}
+
+static void ProcessLineStatus(struct quatech_port *qt_port,
+			      unsigned char line_status)
+{
+
+	qt_port->shadowLSR =
+	    line_status & (SERIAL_LSR_OE | SERIAL_LSR_PE | SERIAL_LSR_FE |
+			   SERIAL_LSR_BI);
+	return;
+}
+
+static void ProcessModemStatus(struct quatech_port *qt_port,
+			       unsigned char modem_status)
+{
+
+	qt_port->shadowMSR = modem_status;
+	wake_up_interruptible(&qt_port->wait);
+	return;
+}
+
+static void ProcessRxChar(struct usb_serial_port *port, unsigned char Data)
+{
+	struct tty_struct *tty;
+	struct urb *urb = port->read_urb;
+	tty = tty_port_tty_get(&port->port);
+
+	/* if we insert more than TTY_FLIPBUF_SIZE characters, we drop them. */
+
+	if (tty && urb->actual_length) {
+		tty_buffer_request_room(tty, 1);
+		tty_insert_flip_string(tty, &Data, 1);
+		/* tty_flip_buffer_push(tty); */
+	}
+
+	return;
+}
+
+static void qt_write_bulk_callback(struct urb *urb)
+{
+	struct tty_struct *tty;
+	int status;
+	struct quatech_port *quatech_port;
+
+	status = urb->status;
+
+	if (status) {
+		dbg("nonzero write bulk status received:%d\n", status);
+		return;
+	}
+
+	quatech_port = urb->context;
+
+	dbg("%s - port %d\n", __func__, quatech_port->port_num);
+
+	tty = tty_port_tty_get(&quatech_port->port->port);
+
+	if (tty)
+		tty_wakeup(tty);
+	tty_kref_put(tty);
+}
+
+static void qt_interrupt_callback(struct urb *urb)
+{
+	/* FIXME */
+}
+
+static void qt_read_bulk_callback(struct urb *urb)
+{
+
+	struct usb_serial_port *port = urb->context;
+	struct usb_serial *serial = get_usb_serial(port, __func__);
+	struct quatech_port *qt_port = qt_get_port_private(port);
+	unsigned char *data;
+	struct tty_struct *tty;
+	unsigned int index;
+	unsigned int RxCount;
+	int i, result;
+	int flag, flag_data;
+
+	if (urb->status) {
+		qt_port->ReadBulkStopped = 1;
+		dbg("%s - nonzero write bulk status received: %d\n",
+		    __func__, urb->status);
+		return;
+	}
+
+	tty = tty_port_tty_get(&port->port);
+	if (!tty) {
+		dbg("%s - bad tty pointer - exiting", __func__);
+		return;
+	}
+
+	data = urb->transfer_buffer;
+
+	RxCount = urb->actual_length;
+
+	/* index = MINOR(port->tty->device) - serial->minor; */
+	index = tty->index - serial->minor;
+
+	dbg("%s - port %d\n", __func__, port->number);
+	dbg("%s - port->RxHolding = %d\n", __func__, qt_port->RxHolding);
+
+	if (port_paranoia_check(port, __func__) != 0) {
+		dbg("%s - port_paranoia_check, exiting\n", __func__);
+		qt_port->ReadBulkStopped = 1;
+		return;
+	}
+
+	if (!serial) {
+		dbg("%s - bad serial pointer, exiting\n", __func__);
+		return;
+	}
+	if (qt_port->closePending == 1) {
+		/* Were closing , stop reading */
+		dbg("%s - (qt_port->closepending == 1\n", __func__);
+		qt_port->ReadBulkStopped = 1;
+		return;
+	}
+
+	/*
+	 * RxHolding is asserted by throttle, if we assert it, we're not
+	 * receiving any more characters and let the box handle the flow
+	 * control
+	 */
+	if (qt_port->RxHolding == 1) {
+		qt_port->ReadBulkStopped = 1;
+		return;
+	}
+
+	if (urb->status) {
+		qt_port->ReadBulkStopped = 1;
+
+		dbg("%s - nonzero read bulk status received: %d\n",
+		    __func__, urb->status);
+		return;
+	}
+
+	if (tty && RxCount) {
+		flag_data = 0;
+		for (i = 0; i < RxCount; ++i) {
+			/* Look ahead code here */
+			if ((i <= (RxCount - 3)) && (data[i] == 0x1b)
+			    && (data[i + 1] == 0x1b)) {
+				flag = 0;
+				switch (data[i + 2]) {
+				case 0x00:
+					/* line status change 4th byte must follow */
+					if (i > (RxCount - 4)) {
+						dbg("Illegal escape seuences in received data\n");
+						break;
+					}
+					ProcessLineStatus(qt_port, data[i + 3]);
+					i += 3;
+					flag = 1;
+					break;
+
+				case 0x01:
+					/* Modem status status change 4th byte must follow */
+					dbg("Modem status status. \n");
+					if (i > (RxCount - 4)) {
+						dbg("Illegal escape sequences in received data\n");
+						break;
+					}
+					ProcessModemStatus(qt_port,
+							   data[i + 3]);
+					i += 3;
+					flag = 1;
+					break;
+				case 0xff:
+					dbg("No status sequence. \n");
+
+					ProcessRxChar(port, data[i]);
+					ProcessRxChar(port, data[i + 1]);
+					i += 2;
+					break;
+				}
+				if (flag == 1)
+					continue;
+			}
+
+			if (tty && urb->actual_length) {
+				tty_buffer_request_room(tty, 1);
+				tty_insert_flip_string(tty, (data + i), 1);
+			}
+
+		}
+		tty_flip_buffer_push(tty);
+	}
+
+	/* Continue trying to always read  */
+	usb_fill_bulk_urb(port->read_urb, serial->dev,
+			  usb_rcvbulkpipe(serial->dev,
+					  port->bulk_in_endpointAddress),
+			  port->read_urb->transfer_buffer,
+			  port->read_urb->transfer_buffer_length,
+			  qt_read_bulk_callback, port);
+	result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
+	if (result)
+		dbg("%s - failed resubmitting read urb, error %d",
+		    __func__, result);
+	else {
+		if (tty && RxCount) {
+			tty_flip_buffer_push(tty);
+			tty_schedule_flip(tty);
+		}
+	}
+
+	schedule_work(&port->work);
+}
+
+/*
+ * qt_get_device
+ *   Issue a GET_DEVICE vendor-specific request on the default control pipe If
+ *   successful, fills in the qt_get_device_data structure pointed to by
+ *   device_data, otherwise return a negative error number of the problem.
+ */
+
+static int qt_get_device(struct usb_serial *serial,
+			 struct qt_get_device_data *device_data)
+{
+	int result;
+	unsigned char *transfer_buffer;
+
+	transfer_buffer =
+	    kmalloc(sizeof(struct qt_get_device_data), GFP_KERNEL);
+	if (!transfer_buffer)
+		return -ENOMEM;
+
+	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
+				 QT_SET_GET_DEVICE, 0xc0, 0, 0,
+				 transfer_buffer,
+				 sizeof(struct qt_get_device_data), 300);
+	if (result > 0)
+		memcpy(device_data, transfer_buffer,
+		       sizeof(struct qt_get_device_data));
+	kfree(transfer_buffer);
+
+	return result;
+}
+
+/****************************************************************************
+ *  BoxSetPrebufferLevel
+   TELLS BOX WHEN TO ASSERT FLOW CONTROL
+ ****************************************************************************/
+static int BoxSetPrebufferLevel(struct usb_serial *serial)
+{
+	int result;
+	__u16 buffer_length;
+
+	buffer_length = PREFUFF_LEVEL_CONSERVATIVE;
+	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+				 QT_GET_SET_PREBUF_TRIG_LVL, 0x40,
+				 buffer_length, 0, NULL, 0, 300);
+	return result;
+}
+
+/****************************************************************************
+ *  BoxSetATC
+   TELLS BOX WHEN TO ASSERT automatic transmitter control
+   ****************************************************************************/
+static int BoxSetATC(struct usb_serial *serial, __u16 n_Mode)
+{
+	int result;
+	__u16 buffer_length;
+
+	buffer_length = PREFUFF_LEVEL_CONSERVATIVE;
+
+	result =
+	    usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+			    QT_SET_ATF, 0x40, n_Mode, 0, NULL, 0, 300);
+
+	return result;
+}
+
+/**
+ * qt_set_device
+ *   Issue a SET_DEVICE vendor-specific request on the default control pipe If
+ *   successful returns the number of bytes written, otherwise it returns a
+ *   negative error number of the problem.
+ */
+static int qt_set_device(struct usb_serial *serial,
+			 struct qt_get_device_data *device_data)
+{
+	int result;
+	__u16 length;
+	__u16 PortSettings;
+
+	PortSettings = ((__u16) (device_data->portb));
+	PortSettings = (PortSettings << 8);
+	PortSettings += ((__u16) (device_data->porta));
+
+	length = sizeof(struct qt_get_device_data);
+	dbg("%s - PortSettings = 0x%x\n", __func__, PortSettings);
+
+	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+				 QT_SET_GET_DEVICE, 0x40, PortSettings,
+				 0, NULL, 0, 300);
+	return result;
+}
+
+static int qt_open_channel(struct usb_serial *serial, __u16 Uart_Number,
+			   struct qt_open_channel_data *pDeviceData)
+{
+	int result;
+
+	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
+				 QT_OPEN_CLOSE_CHANNEL,
+				 USBD_TRANSFER_DIRECTION_IN, 1, Uart_Number,
+				 pDeviceData,
+				 sizeof(struct qt_open_channel_data), 300);
+
+	return result;
+
+}
+
+static int qt_close_channel(struct usb_serial *serial, __u16 Uart_Number)
+{
+	int result;
+
+	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
+				 QT_OPEN_CLOSE_CHANNEL,
+				 USBD_TRANSFER_DIRECTION_OUT, 0, Uart_Number,
+				 NULL, 0, 300);
+
+	return result;
+
+}
+
+/****************************************************************************
+* BoxGetRegister
+*	issuse a GET_REGISTER vendor-spcific request on the default control pipe
+*	If successful, fills in the  pValue with the register value asked for
+****************************************************************************/
+static int BoxGetRegister(struct usb_serial *serial, unsigned short Uart_Number,
+			  unsigned short Register_Num, __u8 *pValue)
+{
+	int result;
+	__u16 current_length;
+
+	current_length = sizeof(struct qt_get_device_data);
+
+	result =
+	    usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
+			    QT_GET_SET_REGISTER, 0xC0, Register_Num,
+			    Uart_Number, (void *)pValue, sizeof(*pValue), 300);
+
+	return result;
+}
+
+/****************************************************************************
+* BoxSetRegister
+*	issuse a GET_REGISTER vendor-spcific request on the default control pipe
+*	If successful, fills in the  pValue with the register value asked for
+****************************************************************************/
+static int BoxSetRegister(struct usb_serial *serial, unsigned short Uart_Number,
+			  unsigned short Register_Num, unsigned short Value)
+{
+	int result;
+	unsigned short RegAndByte;
+
+	RegAndByte = Value;
+	RegAndByte = RegAndByte << 8;
+	RegAndByte = RegAndByte + Register_Num;
+
+/*
+	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+				 QT_GET_SET_REGISTER, 0xC0, Register_Num,
+				 Uart_Number, NULL, 0, 300);
+*/
+
+	result =
+	    usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+			    QT_GET_SET_REGISTER, 0x40, RegAndByte, Uart_Number,
+			    NULL, 0, 300);
+
+	return result;
+}
+
+/*
+ * qt_setuart
+ * issuse a SET_UART vendor-spcific request on the default control pipe
+ * If successful sets baud rate divisor and LCR value
+ */
+static int qt_setuart(struct usb_serial *serial, unsigned short Uart_Number,
+		      unsigned short default_divisor, unsigned char default_LCR)
+{
+	int result;
+	unsigned short UartNumandLCR;
+
+	UartNumandLCR = (default_LCR << 8) + Uart_Number;
+
+	result =
+	    usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+			    QT_GET_SET_UART, 0x40, default_divisor,
+			    UartNumandLCR, NULL, 0, 300);
+
+	return result;
+}
+
+static int BoxSetHW_FlowCtrl(struct usb_serial *serial, unsigned int index,
+			     int bSet)
+{
+	__u8 mcr = 0;
+	__u8 msr = 0, MOUT_Value = 0;
+	unsigned int status;
+
+	if (bSet == 1) {
+		/* flow control, box will clear RTS line to prevent remote */
+		mcr = SERIAL_MCR_RTS;
+	} /* device from xmitting more chars */
+	else {
+		/* no flow control to remote device */
+		mcr = 0;
+
+	}
+	MOUT_Value = mcr << 8;
+
+	if (bSet == 1) {
+		/* flow control, box will inhibit xmit data if CTS line is
+		 * asserted */
+		msr = SERIAL_MSR_CTS;
+	} else {
+		/* Box will not inhimbe xmit data due to CTS line */
+		msr = 0;
+	}
+	MOUT_Value |= msr;
+
+	status =
+	    usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+			    QT_HW_FLOW_CONTROL_MASK, 0x40, MOUT_Value,
+			    index, NULL, 0, 300);
+	return status;
+
+}
+
+static int BoxSetSW_FlowCtrl(struct usb_serial *serial, __u16 index,
+			     unsigned char stop_char, unsigned char start_char)
+{
+	__u16 nSWflowout;
+	int result;
+
+	nSWflowout = start_char << 8;
+	nSWflowout = (unsigned short)stop_char;
+
+	result =
+	    usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+			    QT_SW_FLOW_CONTROL_MASK, 0x40, nSWflowout,
+			    index, NULL, 0, 300);
+	return result;
+
+}
+
+static int BoxDisable_SW_FlowCtrl(struct usb_serial *serial, __u16 index)
+{
+	int result;
+
+	result =
+	    usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+			    QT_SW_FLOW_CONTROL_DISABLE, 0x40, 0, index,
+			    NULL, 0, 300);
+	return result;
+
+}
+
+static int qt_startup(struct usb_serial *serial)
+{
+	struct usb_serial_port *port;
+	struct quatech_port *qt_port;
+	struct qt_get_device_data DeviceData;
+	int i;
+	int status;
+
+	dbg("enterting %s", __func__);
+
+	/* Now setup per port private data */
+	for (i = 0; i < serial->num_ports; i++) {
+		port = serial->port[i];
+		qt_port = kzalloc(sizeof(*qt_port), GFP_KERNEL);
+		if (!qt_port) {
+			dbg("%s: kmalloc for quatech_port (%d) failed!.",
+			    __func__, i);
+			return -ENOMEM;
+		}
+		spin_lock_init(&qt_port->lock);
+
+		usb_set_serial_port_data(port, qt_port);
+
+	}
+
+	status = qt_get_device(serial, &DeviceData);
+	if (status < 0) {
+		dbg(__FILE__ "box_get_device failed");
+		goto startup_error;
+	}
+
+	dbg(__FILE__ "DeviceData.portb = 0x%x", DeviceData.portb);
+
+	DeviceData.portb &= ~FULLPWRBIT;
+	dbg(__FILE__ "Changing DeviceData.portb to 0x%x", DeviceData.portb);
+
+	status = qt_set_device(serial, &DeviceData);
+	if (status < 0) {
+		dbg(__FILE__ "qt_set_device failed\n");
+		goto startup_error;
+	}
+
+	status = qt_get_device(serial, &DeviceData);
+	if (status < 0) {
+		dbg(__FILE__ "qt_get_device failed");
+		goto startup_error;
+	}
+
+	switch (serial->dev->descriptor.idProduct) {
+	case QUATECH_SSU100:
+	case QUATECH_DSU100:
+	case QUATECH_QSU100:
+	case QUATECH_ESU100A:
+	case QUATECH_ESU100B:
+	case QUATECH_HSU100A:
+	case QUATECH_HSU100B:
+	case QUATECH_HSU100C:
+	case QUATECH_HSU100D:
+		DeviceData.porta &= ~(RR_BITS | DUPMODE_BITS);
+		DeviceData.porta |= CLKS_X4;
+		DeviceData.portb &= ~(LOOPMODE_BITS);
+		DeviceData.portb |= RS232_MODE;
+		break;
+
+	case QUATECH_SSU200:
+	case QUATECH_DSU200:
+	case QUATECH_QSU200:
+	case QUATECH_ESU200A:
+	case QUATECH_ESU200B:
+	case QUATECH_HSU200A:
+	case QUATECH_HSU200B:
+	case QUATECH_HSU200C:
+	case QUATECH_HSU200D:
+		DeviceData.porta &= ~(RR_BITS | DUPMODE_BITS);
+		DeviceData.porta |= CLKS_X4;
+		DeviceData.portb &= ~(LOOPMODE_BITS);
+		DeviceData.portb |= ALL_LOOPBACK;
+		break;
+	default:
+		DeviceData.porta &= ~(RR_BITS | DUPMODE_BITS);
+		DeviceData.porta |= CLKS_X4;
+		DeviceData.portb &= ~(LOOPMODE_BITS);
+		DeviceData.portb |= RS232_MODE;
+		break;
+
+	}
+
+	status = BoxSetPrebufferLevel(serial);	/* sets to default value */
+	if (status < 0) {
+		dbg(__FILE__ "BoxSetPrebufferLevel failed\n");
+		goto startup_error;
+	}
+
+	status = BoxSetATC(serial, ATC_DISABLED);
+	if (status < 0) {
+		dbg(__FILE__ "BoxSetATC failed\n");
+		goto startup_error;
+	}
+
+	dbg(__FILE__ "DeviceData.portb = 0x%x", DeviceData.portb);
+
+	DeviceData.portb |= NEXT_BOARD_POWER_BIT;
+	dbg(__FILE__ "Changing DeviceData.portb to 0x%x", DeviceData.portb);
+
+	status = qt_set_device(serial, &DeviceData);
+	if (status < 0) {
+		dbg(__FILE__ "qt_set_device failed\n");
+		goto startup_error;
+	}
+
+	dbg("Exit Success %s\n", __func__);
+
+	return 0;
+
+startup_error:
+	for (i = 0; i < serial->num_ports; i++) {
+		port = serial->port[i];
+		qt_port = qt_get_port_private(port);
+		kfree(qt_port);
+		usb_set_serial_port_data(port, NULL);
+	}
+
+	dbg("Exit fail %s\n", __func__);
+
+	return -EIO;
+}
+
+static void qt_release(struct usb_serial *serial)
+{
+	struct usb_serial_port *port;
+	struct quatech_port *qt_port;
+	int i;
+
+	dbg("enterting %s", __func__);
+
+	for (i = 0; i < serial->num_ports; i++) {
+		port = serial->port[i];
+		if (!port)
+			continue;
+
+		qt_port = usb_get_serial_port_data(port);
+		kfree(qt_port);
+		usb_set_serial_port_data(port, NULL);
+	}
+
+}
+
+int qt_open(struct tty_struct *tty,
+	    struct usb_serial_port *port, struct file *filp)
+{
+	struct usb_serial *serial;
+	struct quatech_port *quatech_port;
+	struct quatech_port *port0;
+	struct qt_open_channel_data ChannelData;
+
+	int result;
+
+	if (port_paranoia_check(port, __func__))
+		return -ENODEV;
+
+	dbg("%s - port %d\n", __func__, port->number);
+
+	serial = port->serial;
+
+	if (serial_paranoia_check(serial, __func__))
+		return -ENODEV;
+
+	quatech_port = qt_get_port_private(port);
+	port0 = qt_get_port_private(serial->port[0]);
+
+	if (quatech_port == NULL || port0 == NULL)
+		return -ENODEV;
+
+	usb_clear_halt(serial->dev, port->write_urb->pipe);
+	usb_clear_halt(serial->dev, port->read_urb->pipe);
+	port0->open_ports++;
+
+	result = qt_get_device(serial, &port0->DeviceData);
+
+	/* Port specific setups */
+	result = qt_open_channel(serial, port->number, &ChannelData);
+	if (result < 0) {
+		dbg(__FILE__ "qt_open_channel failed\n");
+		return result;
+	}
+	dbg(__FILE__ "qt_open_channel completed.\n");
+
+/* FIXME: are these needed?  Does it even do anything useful? */
+	quatech_port->shadowLSR = ChannelData.line_status &
+	    (SERIAL_LSR_OE | SERIAL_LSR_PE | SERIAL_LSR_FE | SERIAL_LSR_BI);
+
+	quatech_port->shadowMSR = ChannelData.modem_status &
+	    (SERIAL_MSR_CTS | SERIAL_MSR_DSR | SERIAL_MSR_RI | SERIAL_MSR_CD);
+
+	/* Set Baud rate to default and turn off (default)flow control here */
+	result = qt_setuart(serial, port->number, DEFAULT_DIVISOR, DEFAULT_LCR);
+	if (result < 0) {
+		dbg(__FILE__ "qt_setuart failed\n");
+		return result;
+	}
+	dbg(__FILE__ "qt_setuart completed.\n");
+
+	/*
+	 * Put this here to make it responsive to stty and defauls set by
+	 * the tty layer
+	 */
+	/* FIXME: is this needed? */
+	/* qt_set_termios(tty, port, NULL); */
+
+	/*  Check to see if we've set up our endpoint info yet */
+	if (port0->open_ports == 1) {
+		if (serial->port[0]->interrupt_in_buffer == NULL) {
+			/* set up interrupt urb */
+			usb_fill_int_urb(serial->port[0]->interrupt_in_urb,
+					 serial->dev,
+					 usb_rcvintpipe(serial->dev,
+							serial->port[0]->interrupt_in_endpointAddress),
+					 serial->port[0]->interrupt_in_buffer,
+					 serial->port[0]->
+					 interrupt_in_urb->transfer_buffer_length,
+					 qt_interrupt_callback, serial,
+					 serial->port[0]->
+					 interrupt_in_urb->interval);
+
+			result =
+			    usb_submit_urb(serial->port[0]->interrupt_in_urb,
+					   GFP_KERNEL);
+			if (result) {
+				dev_err(&port->dev,
+					"%s - Error %d submitting "
+					"interrupt urb\n", __func__, result);
+			}
+
+		}
+
+	}
+
+	dbg("port number is %d \n", port->number);
+	dbg("serial number is %d \n", port->serial->minor);
+	dbg("Bulkin endpoint is %d \n", port->bulk_in_endpointAddress);
+	dbg("BulkOut endpoint is %d \n", port->bulk_out_endpointAddress);
+	dbg("Interrupt endpoint is %d \n", port->interrupt_in_endpointAddress);
+	dbg("port's number in the device is %d\n", quatech_port->port_num);
+	quatech_port->read_urb = port->read_urb;
+
+	/* set up our bulk in urb */
+
+	usb_fill_bulk_urb(quatech_port->read_urb,
+			  serial->dev,
+			  usb_rcvbulkpipe(serial->dev,
+					  port->bulk_in_endpointAddress),
+			  port->bulk_in_buffer,
+			  quatech_port->read_urb->transfer_buffer_length,
+			  qt_read_bulk_callback, quatech_port);
+
+	dbg("qt_open: bulkin endpoint is %d\n", port->bulk_in_endpointAddress);
+	quatech_port->read_urb_busy = true;
+	result = usb_submit_urb(quatech_port->read_urb, GFP_KERNEL);
+	if (result) {
+		dev_err(&port->dev,
+			"%s - Error %d submitting control urb\n",
+			__func__, result);
+		quatech_port->read_urb_busy = false;
+	}
+
+	/* initialize our wait queues */
+	init_waitqueue_head(&quatech_port->wait);
+	init_waitqueue_head(&quatech_port->msr_wait);
+
+	/* initialize our icount structure */
+	memset(&(quatech_port->icount), 0x00, sizeof(quatech_port->icount));
+
+	return 0;
+
+}
+
+static int qt_chars_in_buffer(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct usb_serial *serial;
+	int chars = 0;
+
+	serial = get_usb_serial(port, __func__);
+
+	dbg("%s - port %d\n", __func__, port->number);
+
+	if (serial->num_bulk_out) {
+		if (port->write_urb->status == -EINPROGRESS)
+			chars = port->write_urb->transfer_buffer_length;
+	}
+
+	dbg("%s - returns %d\n", __func__, chars);
+
+	return chars;
+}
+
+static void qt_block_until_empty(struct tty_struct *tty,
+				 struct quatech_port *qt_port)
+{
+	int timeout = HZ / 10;
+	int wait = 30;
+	int count;
+
+	while (1) {
+
+		count = qt_chars_in_buffer(tty);
+
+		if (count <= 0)
+			return;
+
+		interruptible_sleep_on_timeout(&qt_port->wait, timeout);
+
+		wait--;
+		if (wait == 0) {
+			dbg("%s - TIMEOUT", __func__);
+			return;
+		} else {
+			wait = 30;
+		}
+	}
+}
+
+static void qt_close(struct tty_struct *tty, struct usb_serial_port *port,
+		     struct file *filp)
+{
+	struct usb_serial *serial = port->serial;
+	struct quatech_port *qt_port;
+	struct quatech_port *port0;
+	int status;
+	unsigned int index;
+	status = 0;
+
+	dbg("%s - port %d\n", __func__, port->number);
+	index = tty->index - serial->minor;
+
+	qt_port = qt_get_port_private(port);
+	port0 = qt_get_port_private(serial->port[0]);
+
+	/* shutdown any bulk reads that might be going on */
+	if (serial->num_bulk_out)
+		usb_unlink_urb(port->write_urb);
+	if (serial->num_bulk_in)
+		usb_unlink_urb(port->read_urb);
+
+	/* wait up to for transmitter to empty */
+	if (serial->dev)
+		qt_block_until_empty(tty, qt_port);
+
+	/* Close uart channel */
+	status = qt_close_channel(serial, index);
+	if (status < 0)
+		dbg("%s - port %d qt_close_channel failed.\n",
+		    __func__, port->number);
+
+	port0->open_ports--;
+
+	dbg("qt_num_open_ports in close%d:in port%d\n",
+	    port0->open_ports, port->number);
+
+	if (port0->open_ports == 0) {
+		if (serial->port[0]->interrupt_in_urb) {
+			dbg("%s", "Shutdown interrupt_in_urb\n");
+			usb_kill_urb(serial->port[0]->interrupt_in_urb);
+		}
+
+	}
+
+	if (qt_port->write_urb) {
+		/* if this urb had a transfer buffer already (old tx) free it */
+		if (qt_port->write_urb->transfer_buffer != NULL)
+			kfree(qt_port->write_urb->transfer_buffer);
+		usb_free_urb(qt_port->write_urb);
+	}
+
+}
+
+static int qt_write(struct tty_struct *tty, struct usb_serial_port *port,
+		    const unsigned char *buf, int count)
+{
+	int result;
+	struct usb_serial *serial = get_usb_serial(port, __func__);
+
+	if (serial == NULL)
+		return -ENODEV;
+
+	dbg("%s - port %d\n", __func__, port->number);
+
+	if (count == 0) {
+		dbg("%s - write request of 0 bytes\n", __func__);
+		return 0;
+	}
+
+	/* only do something if we have a bulk out endpoint */
+	if (serial->num_bulk_out) {
+		if (port->write_urb->status == -EINPROGRESS) {
+			dbg("%s - already writing\n", __func__);
+			return 0;
+		}
+
+		count =
+		    (count > port->bulk_out_size) ? port->bulk_out_size : count;
+		memcpy(port->write_urb->transfer_buffer, buf, count);
+
+		/* set up our urb */
+
+		usb_fill_bulk_urb(port->write_urb, serial->dev,
+				  usb_sndbulkpipe(serial->dev,
+						  port->
+						  bulk_out_endpointAddress),
+				  port->write_urb->transfer_buffer, count,
+				  qt_write_bulk_callback, port);
+
+		/* send the data out the bulk port */
+		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
+		if (result)
+			dbg("%s - failed submitting write urb, error %d\n",
+			    __func__, result);
+		else
+			result = count;
+
+		return result;
+	}
+
+	/* no bulk out, so return 0 bytes written */
+	return 0;
+}
+
+static int qt_write_room(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct usb_serial *serial;
+	struct quatech_port *qt_port;
+	unsigned long flags;
+
+	int retval = -EINVAL;
+
+	if (port_paranoia_check(port, __func__)) {
+		dbg("%s", "Invalid port\n");
+		return -1;
+	}
+
+	serial = get_usb_serial(port, __func__);
+
+	if (!serial)
+		return -ENODEV;
+
+	qt_port = qt_get_port_private(port);
+
+	spin_lock_irqsave(&qt_port->lock, flags);
+
+	dbg("%s - port %d\n", __func__, port->number);
+
+	if (serial->num_bulk_out) {
+		if (port->write_urb->status != -EINPROGRESS)
+			retval = port->bulk_out_size;
+	}
+
+	spin_unlock_irqrestore(&qt_port->lock, flags);
+	return retval;
+
+}
+
+static int qt_ioctl(struct tty_struct *tty, struct file *file,
+		    unsigned int cmd, unsigned long arg)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct quatech_port *qt_port = qt_get_port_private(port);
+	struct usb_serial *serial = get_usb_serial(port, __func__);
+	unsigned int index;
+
+	dbg("%s cmd 0x%04x", __func__, cmd);
+
+	index = tty->index - serial->minor;
+
+	if (cmd == TIOCMIWAIT) {
+		while (qt_port != NULL) {
+			interruptible_sleep_on(&qt_port->msr_wait);
+			if (signal_pending(current))
+				return -ERESTARTSYS;
+			else {
+				char diff = qt_port->diff_status;
+
+				if (diff == 0)
+					return -EIO;	/* no change => error */
+
+				/* Consume all events */
+				qt_port->diff_status = 0;
+
+				if (((arg & TIOCM_RNG)
+				     && (diff & SERIAL_MSR_RI))
+				    || ((arg & TIOCM_DSR)
+					&& (diff & SERIAL_MSR_DSR))
+				    || ((arg & TIOCM_CD)
+					&& (diff & SERIAL_MSR_CD))
+				    || ((arg & TIOCM_CTS)
+					&& (diff & SERIAL_MSR_CTS))) {
+					return 0;
+				}
+			}
+		}
+		return 0;
+	}
+
+	dbg("%s -No ioctl for that one.  port = %d\n", __func__, port->number);
+	return -ENOIOCTLCMD;
+}
+
+static void qt_set_termios(struct tty_struct *tty,
+			   struct usb_serial_port *port,
+			   struct ktermios *old_termios)
+{
+	struct ktermios *termios = tty->termios;
+	unsigned char new_LCR = 0;
+	unsigned int cflag = termios->c_cflag;
+	unsigned int index;
+	int baud, divisor, remainder;
+	int status;
+
+	dbg("%s", __func__);
+
+	index = tty->index - port->serial->minor;
+
+	switch (cflag) {
+	case CS5:
+		new_LCR |= SERIAL_5_DATA;
+		break;
+	case CS6:
+		new_LCR |= SERIAL_6_DATA;
+		break;
+	case CS7:
+		new_LCR |= SERIAL_7_DATA;
+		break;
+	default:
+	case CS8:
+		new_LCR |= SERIAL_8_DATA;
+		break;
+	}
+
+	/* Parity stuff */
+	if (cflag & PARENB) {
+		if (cflag & PARODD)
+			new_LCR |= SERIAL_ODD_PARITY;
+		else
+			new_LCR |= SERIAL_EVEN_PARITY;
+	}
+	if (cflag & CSTOPB)
+		new_LCR |= SERIAL_TWO_STOPB;
+	else
+		new_LCR |= SERIAL_TWO_STOPB;
+
+	dbg("%s - 4\n", __func__);
+
+	/* Thats the LCR stuff, go ahead and set it */
+	baud = tty_get_baud_rate(tty);
+	if (!baud)
+		/* pick a default, any default... */
+		baud = 9600;
+
+	dbg("%s - got baud = %d\n", __func__, baud);
+
+	divisor = MAX_BAUD_RATE / baud;
+	remainder = MAX_BAUD_RATE % baud;
+	/* Round to nearest divisor */
+	if (((remainder * 2) >= baud) && (baud != 110))
+		divisor++;
+
+	/*
+	 * Set Baud rate to default and turn off (default)flow control here
+	 */
+	status =
+	    qt_setuart(port->serial, index, (unsigned short)divisor, new_LCR);
+	if (status < 0) {
+		dbg(__FILE__ "qt_setuart failed\n");
+		return;
+	}
+
+	/* Now determine flow control */
+	if (cflag & CRTSCTS) {
+		dbg("%s - Enabling HW flow control port %d\n", __func__,
+		    port->number);
+
+		/* Enable RTS/CTS flow control */
+		status = BoxSetHW_FlowCtrl(port->serial, index, 1);
+
+		if (status < 0) {
+			dbg(__FILE__ "BoxSetHW_FlowCtrl failed\n");
+			return;
+		}
+	} else {
+		/* Disable RTS/CTS flow control */
+		dbg("%s - disabling HW flow control port %d\n", __func__,
+		    port->number);
+
+		status = BoxSetHW_FlowCtrl(port->serial, index, 0);
+		if (status < 0) {
+			dbg(__FILE__ "BoxSetHW_FlowCtrl failed\n");
+			return;
+		}
+
+	}
+
+	/* if we are implementing XON/XOFF, set the start and stop character in
+	 * the device */
+	if (I_IXOFF(tty) || I_IXON(tty)) {
+		unsigned char stop_char = STOP_CHAR(tty);
+		unsigned char start_char = START_CHAR(tty);
+		status =
+		    BoxSetSW_FlowCtrl(port->serial, index, stop_char,
+				      start_char);
+		if (status < 0)
+			dbg(__FILE__ "BoxSetSW_FlowCtrl (enabled) failed\n");
+
+	} else {
+		/* disable SW flow control */
+		status = BoxDisable_SW_FlowCtrl(port->serial, index);
+		if (status < 0)
+			dbg(__FILE__ "BoxSetSW_FlowCtrl (diabling) failed\n");
+
+	}
+	tty->termios->c_cflag &= ~CMSPAR;
+	/* FIXME: Error cases should be returning the actual bits changed only */
+}
+
+static void qt_break(struct tty_struct *tty, int break_state)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct usb_serial *serial = get_usb_serial(port, __func__);
+	struct quatech_port *qt_port;
+	u16 index, onoff;
+	unsigned int result;
+	unsigned long flags;
+
+	index = tty->index - serial->minor;
+
+	qt_port = qt_get_port_private(port);
+
+	if (break_state == -1)
+		onoff = 1;
+	else
+		onoff = 0;
+
+	spin_lock_irqsave(&qt_port->lock, flags);
+
+	dbg("%s - port %d\n", __func__, port->number);
+
+	result =
+	    usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+			    QT_BREAK_CONTROL, 0x40, onoff, index, NULL, 0, 300);
+
+	spin_unlock_irqrestore(&qt_port->lock, flags);
+}
+
+static inline int qt_real_tiocmget(struct tty_struct *tty,
+				   struct usb_serial_port *port,
+				   struct file *file, struct usb_serial *serial)
+{
+
+	u8 mcr;
+	u8 msr;
+	unsigned int result = 0;
+	int status;
+	unsigned int index;
+
+	dbg("%s - port %d, tty =0x%p\n", __func__, port->number, tty);
+
+	index = tty->index - serial->minor;
+	status =
+	    BoxGetRegister(port->serial, index, MODEM_CONTROL_REGISTER, &mcr);
+	if (status >= 0) {
+		status =
+		    BoxGetRegister(port->serial, index,
+				   MODEM_STATUS_REGISTER, &msr);
+
+	}
+
+	if (status >= 0) {
+		result = ((mcr & SERIAL_MCR_DTR) ? TIOCM_DTR : 0)
+		    /* DTR IS SET */
+		    | ((mcr & SERIAL_MCR_RTS) ? TIOCM_RTS : 0)
+		    /* RTS IS SET */
+		    | ((msr & SERIAL_MSR_CTS) ? TIOCM_CTS : 0)
+		    /* CTS is set */
+		    | ((msr & SERIAL_MSR_CD) ? TIOCM_CAR : 0)
+		    /* Carrier detect is set */
+		    | ((msr & SERIAL_MSR_RI) ? TIOCM_RI : 0)
+		    /* Ring indicator set */
+		    | ((msr & SERIAL_MSR_DSR) ? TIOCM_DSR : 0);
+		/* DSR is set */
+		return result;
+
+	} else
+		return -ESPIPE;
+}
+
+static inline int qt_real_tiocmset(struct tty_struct *tty,
+				   struct usb_serial_port *port,
+				   struct file *file,
+				   struct usb_serial *serial,
+				   unsigned int value)
+{
+
+	u8 mcr;
+	int status;
+	unsigned int index;
+
+	dbg("%s - port %d\n", __func__, port->number);
+
+	index = tty->index - serial->minor;
+	status =
+	    BoxGetRegister(port->serial, index, MODEM_CONTROL_REGISTER, &mcr);
+	if (status < 0)
+		return -ESPIPE;
+
+	/*
+	 * Turn off the RTS and DTR and loopbcck and then only turn on what was
+	 * asked for
+	 */
+	mcr &= ~(SERIAL_MCR_RTS | SERIAL_MCR_DTR | SERIAL_MCR_LOOP);
+	if (value & TIOCM_RTS)
+		mcr |= SERIAL_MCR_RTS;
+	if (value & TIOCM_DTR)
+		mcr |= SERIAL_MCR_DTR;
+	if (value & TIOCM_LOOP)
+		mcr |= SERIAL_MCR_LOOP;
+
+	status =
+	    BoxSetRegister(port->serial, index, MODEM_CONTROL_REGISTER, mcr);
+	if (status < 0)
+		return -ESPIPE;
+	else
+		return 0;
+}
+
+static int qt_tiocmget(struct tty_struct *tty, struct file *file)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct usb_serial *serial = get_usb_serial(port, __func__);
+	struct quatech_port *qt_port = qt_get_port_private(port);
+	int retval = -ENODEV;
+	unsigned long flags;
+
+	dbg("In %s \n", __func__);
+
+	if (!serial)
+		return -ENODEV;
+
+	spin_lock_irqsave(&qt_port->lock, flags);
+
+	dbg("%s - port %d\n", __func__, port->number);
+	dbg("%s - port->RxHolding = %d\n", __func__, qt_port->RxHolding);
+
+	retval = qt_real_tiocmget(tty, port, file, serial);
+
+	spin_unlock_irqrestore(&qt_port->lock, flags);
+	return retval;
+}
+
+static int qt_tiocmset(struct tty_struct *tty, struct file *file,
+		       unsigned int set, unsigned int clear)
+{
+
+	struct usb_serial_port *port = tty->driver_data;
+	struct usb_serial *serial = get_usb_serial(port, __func__);
+	struct quatech_port *qt_port = qt_get_port_private(port);
+	unsigned long flags;
+	int retval = -ENODEV;
+
+	dbg("In %s \n", __func__);
+
+	if (!serial)
+		return -ENODEV;
+
+	spin_lock_irqsave(&qt_port->lock, flags);
+
+	dbg("%s - port %d \n", __func__, port->number);
+	dbg("%s - qt_port->RxHolding = %d\n", __func__, qt_port->RxHolding);
+
+	retval = qt_real_tiocmset(tty, port, file, serial, set);
+
+	spin_unlock_irqrestore(&qt_port->lock, flags);
+	return retval;
+}
+
+static void qt_throttle(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct usb_serial *serial = get_usb_serial(port, __func__);
+	struct quatech_port *qt_port;
+	unsigned long flags;
+
+	dbg("%s - port %d\n", __func__, port->number);
+
+	if (!serial)
+		return;
+
+	qt_port = qt_get_port_private(port);
+
+	spin_lock_irqsave(&qt_port->lock, flags);
+
+	/* pass on to the driver specific version of this function */
+	qt_port->RxHolding = 1;
+	dbg("%s - port->RxHolding = 1\n", __func__);
+
+	spin_unlock_irqrestore(&qt_port->lock, flags);
+	return;
+}
+
+static void qt_unthrottle(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct usb_serial *serial = get_usb_serial(port, __func__);
+	struct quatech_port *qt_port;
+	unsigned long flags;
+	unsigned int result;
+
+	if (!serial)
+		return;
+
+	qt_port = qt_get_port_private(port);
+
+	spin_lock_irqsave(&qt_port->lock, flags);
+
+	dbg("%s - port %d\n", __func__, port->number);
+
+	if (qt_port->RxHolding == 1) {
+		dbg("%s -qt_port->RxHolding == 1\n", __func__);
+
+		qt_port->RxHolding = 0;
+		dbg("%s - qt_port->RxHolding = 0\n", __func__);
+
+		/* if we have a bulk endpoint, start it up */
+		if ((serial->num_bulk_in) && (qt_port->ReadBulkStopped == 1)) {
+			/* Start reading from the device */
+			usb_fill_bulk_urb(port->read_urb, serial->dev,
+					  usb_rcvbulkpipe(serial->dev,
+							  port->bulk_in_endpointAddress),
+					  port->read_urb->transfer_buffer,
+					  port->read_urb->
+					  transfer_buffer_length,
+					  qt_read_bulk_callback, port);
+			result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
+			if (result)
+				err("%s - failed restarting read urb, error %d",
+				    __func__, result);
+		}
+	}
+	spin_unlock_irqrestore(&qt_port->lock, flags);
+	return;
+
+}
+
+static int qt_calc_num_ports(struct usb_serial *serial)
+{
+	int num_ports;
+
+	dbg("numberofendpoints: %d \n",
+	    (int)serial->interface->cur_altsetting->desc.bNumEndpoints);
+	dbg("numberofendpoints: %d \n",
+	    (int)serial->interface->altsetting->desc.bNumEndpoints);
+
+	num_ports =
+	    (serial->interface->cur_altsetting->desc.bNumEndpoints - 1) / 2;
+
+	return num_ports;
+}
+
+static struct usb_serial_driver quatech_device = {
+	.driver = {
+		   .owner = THIS_MODULE,
+		   .name = "serqt",
+		   },
+	.description = DRIVER_DESC,
+	.usb_driver = &serqt_usb_driver,
+	.id_table = serqt_id_table,
+	.num_ports = 8,
+	.open = qt_open,
+	.close = qt_close,
+	.write = qt_write,
+	.write_room = qt_write_room,
+	.chars_in_buffer = qt_chars_in_buffer,
+	.throttle = qt_throttle,
+	.unthrottle = qt_unthrottle,
+	.calc_num_ports = qt_calc_num_ports,
+	.ioctl = qt_ioctl,
+	.set_termios = qt_set_termios,
+	.break_ctl = qt_break,
+	.tiocmget = qt_tiocmget,
+	.tiocmset = qt_tiocmset,
+	.attach = qt_startup,
+	.release = qt_release,
+};
+
+static int __init serqt_usb_init(void)
+{
+	int retval;
+
+	dbg("%s\n", __func__);
+
+	/* register with usb-serial */
+	retval = usb_serial_register(&quatech_device);
+
+	if (retval)
+		goto failed_usb_serial_register;
+
+	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
+	       DRIVER_DESC "\n");
+
+	/* register with usb */
+
+	retval = usb_register(&serqt_usb_driver);
+	if (retval == 0)
+		return 0;
+
+	/* if we're here, usb_register() failed */
+	usb_serial_deregister(&quatech_device);
+failed_usb_serial_register:
+	return retval;
+}
+
+static void __exit serqt_usb_exit(void)
+{
+	usb_deregister(&serqt_usb_driver);
+	usb_serial_deregister(&quatech_device);
+}
+
+module_init(serqt_usb_init);
+module_exit(serqt_usb_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");