USB: serial: add quatech2 usb to serial driver
authorBill Pemberton <wfp5p@virginia.edu>
Thu, 10 May 2012 19:36:02 +0000 (15:36 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 10 May 2012 19:46:20 +0000 (12:46 -0700)
This supports the Quatech USB 2 usb to serial adapters.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/serial/Kconfig
drivers/usb/serial/Makefile
drivers/usb/serial/quatech2.c [new file with mode: 0644]

index 7141d6599060c3a6fa6bd428b589b20527d0f211..325d2910f9f9462b8a23f263d6e576f7fbe54cf7 100644 (file)
@@ -669,6 +669,15 @@ config USB_SERIAL_SSU100
          To compile this driver as a module, choose M here: the
          module will be called ssu100.
 
+config USB_SERIAL_QT2
+       tristate "USB Quatech Serial Driver for USB 2 devices"
+       help
+         Say Y here if you want to use the Quatech USB 2
+         serial adapters.
+
+         To compile this driver as a module, choose M here: the
+         module will be called quatech-serial.
+
 config USB_SERIAL_DEBUG
        tristate "USB Debugging Device"
        help
index 07f198ee0486f503778a966471b0cfb5bfb92050..1dc483a8bfc79af7d537b97a64ca557dc78d4f8e 100644 (file)
@@ -49,6 +49,7 @@ obj-$(CONFIG_USB_SERIAL_OTI6858)              += oti6858.o
 obj-$(CONFIG_USB_SERIAL_PL2303)                        += pl2303.o
 obj-$(CONFIG_USB_SERIAL_QCAUX)                 += qcaux.o
 obj-$(CONFIG_USB_SERIAL_QUALCOMM)              += qcserial.o
+obj-$(CONFIG_USB_SERIAL_QT2)                   += quatech2.o
 obj-$(CONFIG_USB_SERIAL_SAFE)                  += safe_serial.o
 obj-$(CONFIG_USB_SERIAL_SIEMENS_MPI)           += siemens_mpi.o
 obj-$(CONFIG_USB_SERIAL_SIERRAWIRELESS)                += sierra.o
diff --git a/drivers/usb/serial/quatech2.c b/drivers/usb/serial/quatech2.c
new file mode 100644 (file)
index 0000000..3aa63f1
--- /dev/null
@@ -0,0 +1,1149 @@
+/*
+ * usb-serial driver for Quatech USB 2 devices
+ *
+ *
+ *  These devices all have only 1 bulk in and 1 bulk out that is shared
+ *  for all serial ports.
+ *
+ */
+
+#include <asm/unaligned.h>
+#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/serial_reg.h>
+#include <linux/uaccess.h>
+
+static bool debug;
+
+/* default urb timeout for usb operations */
+#define QT2_USB_TIMEOUT USB_CTRL_SET_TIMEOUT
+
+#define QT_OPEN_CLOSE_CHANNEL       0xca
+#define QT_SET_GET_DEVICE           0xc2
+#define QT_SET_GET_REGISTER         0xc0
+#define QT_GET_SET_PREBUF_TRIG_LVL  0xcc
+#define QT_SET_ATF                  0xcd
+#define QT_TRANSFER_IN              0xc0
+#define QT_HW_FLOW_CONTROL_MASK     0xc5
+#define QT_SW_FLOW_CONTROL_MASK     0xc6
+#define QT2_BREAK_CONTROL          0xc8
+#define QT2_GET_SET_UART            0xc1
+#define QT2_FLUSH_DEVICE           0xc4
+#define QT2_GET_SET_QMCR            0xe1
+#define QT2_QMCR_RS232              0x40
+#define QT2_QMCR_RS422              0x10
+
+#define  SERIAL_CRTSCTS ((UART_MCR_RTS << 8) | UART_MSR_CTS)
+
+#define  SERIAL_EVEN_PARITY         (UART_LCR_PARITY | UART_LCR_EPAR)
+
+/* status bytes for the device */
+#define QT2_CONTROL_BYTE    0x1b
+#define QT2_LINE_STATUS     0x00  /* following 1 byte is line status */
+#define QT2_MODEM_STATUS    0x01  /* following 1 byte is modem status */
+#define QT2_XMIT_HOLD       0x02  /* following 2 bytes are ?? */
+#define QT2_CHANGE_PORT     0x03  /* following 1 byte is port to change to */
+#define QT2_REC_FLUSH       0x04  /* no following info */
+#define QT2_XMIT_FLUSH      0x05  /* no following info */
+#define QT2_CONTROL_ESCAPE  0xff  /* pass through previous 2 control bytes */
+
+#define  MAX_BAUD_RATE              921600
+#define  DEFAULT_BAUD_RATE          9600
+
+#define QT2_WRITE_BUFFER_SIZE   512  /* size of write buffer */
+#define QT2_WRITE_CONTROL_SIZE  5    /* control bytes used for a write */
+
+/* Version Information */
+#define DRIVER_VERSION "v0.1"
+#define DRIVER_DESC "Quatech 2nd gen USB to Serial Driver"
+
+#define        USB_VENDOR_ID_QUATECH   0x061d
+#define QUATECH_SSU2_100       0xC120  /* RS232 single port */
+#define QUATECH_DSU2_100       0xC140  /* RS232 dual port */
+#define QUATECH_DSU2_400       0xC150  /* RS232/422/485 dual port */
+#define QUATECH_QSU2_100       0xC160  /* RS232 four port */
+#define QUATECH_QSU2_400       0xC170  /* RS232/422/485 four port */
+#define QUATECH_ESU2_100       0xC1A0  /* RS232 eight port */
+#define QUATECH_ESU2_400       0xC180  /* RS232/422/485 eight port */
+
+struct qt2_device_detail {
+       int product_id;
+       int num_ports;
+};
+
+#define QT_DETAILS(prod, ports)        \
+       .product_id = (prod),   \
+       .num_ports = (ports)
+
+static const struct qt2_device_detail qt2_device_details[] = {
+       {QT_DETAILS(QUATECH_SSU2_100, 1)},
+       {QT_DETAILS(QUATECH_DSU2_400, 2)},
+       {QT_DETAILS(QUATECH_DSU2_100, 2)},
+       {QT_DETAILS(QUATECH_QSU2_400, 4)},
+       {QT_DETAILS(QUATECH_QSU2_100, 4)},
+       {QT_DETAILS(QUATECH_ESU2_400, 8)},
+       {QT_DETAILS(QUATECH_ESU2_100, 8)},
+       {QT_DETAILS(0, 0)}      /* Terminating entry */
+};
+
+static const struct usb_device_id id_table[] = {
+       {USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_SSU2_100)},
+       {USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_DSU2_100)},
+       {USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_DSU2_400)},
+       {USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_QSU2_100)},
+       {USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_QSU2_400)},
+       {USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU2_100)},
+       {USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU2_400)},
+       {}                      /* Terminating entry */
+};
+MODULE_DEVICE_TABLE(usb, id_table);
+
+struct qt2_serial_private {
+       unsigned char current_port;  /* current port for incoming data */
+
+       struct urb      *read_urb;   /* shared among all ports */
+       char            read_buffer[512];
+};
+
+struct qt2_port_private {
+       bool is_open;
+       u8   device_port;
+
+       spinlock_t urb_lock;
+       bool       urb_in_use;
+       struct urb *write_urb;
+       char       write_buffer[QT2_WRITE_BUFFER_SIZE];
+
+       spinlock_t  lock;
+       u8          shadowLSR;
+       u8          shadowMSR;
+
+       wait_queue_head_t   delta_msr_wait; /* Used for TIOCMIWAIT */
+       struct async_icount icount;
+
+       struct usb_serial_port *port;
+};
+
+static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch);
+static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch);
+static void qt2_write_bulk_callback(struct urb *urb);
+static void qt2_read_bulk_callback(struct urb *urb);
+
+static void qt2_release(struct usb_serial *serial)
+{
+       int i;
+
+       kfree(usb_get_serial_data(serial));
+
+       for (i = 0; i < serial->num_ports; i++)
+               kfree(usb_get_serial_port_data(serial->port[i]));
+}
+
+static inline int calc_baud_divisor(int baudrate)
+{
+       int divisor, rem;
+
+       divisor = MAX_BAUD_RATE / baudrate;
+       rem = MAX_BAUD_RATE % baudrate;
+       /* Round to nearest divisor */
+       if (((rem * 2) >= baudrate) && (baudrate != 110))
+               divisor++;
+
+       return divisor;
+}
+
+static inline int qt2_set_port_config(struct usb_device *dev,
+                                     unsigned char port_number,
+                                     u16 baudrate, u16 lcr)
+{
+       int divisor = calc_baud_divisor(baudrate);
+       u16 index = ((u16) (lcr << 8) | (u16) (port_number));
+
+       return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+                              QT2_GET_SET_UART, 0x40,
+                              divisor, index, NULL, 0, QT2_USB_TIMEOUT);
+}
+
+static inline int qt2_control_msg(struct usb_device *dev,
+                                 u8 request, u16 data, u16 index)
+{
+       return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+                              request, 0x40, data, index,
+                              NULL, 0, QT2_USB_TIMEOUT);
+}
+
+static inline int qt2_setdevice(struct usb_device *dev, u8 *data)
+{
+       u16 x = ((u16) (data[1] << 8) | (u16) (data[0]));
+
+       return qt2_control_msg(dev, QT_SET_GET_DEVICE, x, 0);
+}
+
+
+static inline int qt2_getdevice(struct usb_device *dev, u8 *data)
+{
+       return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
+                              QT_SET_GET_DEVICE, 0xc0, 0, 0,
+                              data, 3, QT2_USB_TIMEOUT);
+}
+
+static inline int qt2_getregister(struct usb_device *dev,
+                                 u8 uart,
+                                 u8 reg,
+                                 u8 *data)
+{
+       return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
+                              QT_SET_GET_REGISTER, 0xc0, reg,
+                              uart, data, sizeof(*data), QT2_USB_TIMEOUT);
+
+}
+
+static inline int qt2_setregister(struct usb_device *dev,
+                                 u8 uart, u8 reg, u16 data)
+{
+       u16 value = (data << 8) | reg;
+
+       return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+                              QT_SET_GET_REGISTER, 0x40, value, uart,
+                              NULL, 0, QT2_USB_TIMEOUT);
+}
+
+static inline int update_mctrl(struct qt2_port_private *port_priv,
+                              unsigned int set, unsigned int clear)
+{
+       struct usb_serial_port *port = port_priv->port;
+       struct usb_device *dev = port->serial->dev;
+       unsigned urb_value;
+       int status;
+
+       if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0) {
+               dev_dbg(&port->dev,
+                       "update_mctrl - DTR|RTS not being set|cleared\n");
+               return 0;       /* no change */
+       }
+
+       clear &= ~set;  /* 'set' takes precedence over 'clear' */
+       urb_value = 0;
+       if (set & TIOCM_DTR)
+               urb_value |= UART_MCR_DTR;
+       if (set & TIOCM_RTS)
+               urb_value |= UART_MCR_RTS;
+
+       status = qt2_setregister(dev, port_priv->device_port, UART_MCR,
+                                urb_value);
+       if (status < 0)
+               dev_err(&port->dev,
+                       "update_mctrl - Error from MODEM_CTRL urb: %i\n",
+                       status);
+       return status;
+}
+
+static int qt2_calc_num_ports(struct usb_serial *serial)
+{
+       struct qt2_device_detail d;
+       int i;
+
+       for (i = 0; d = qt2_device_details[i], d.product_id != 0; i++) {
+               if (d.product_id == le16_to_cpu(serial->dev->descriptor.idProduct))
+                       return d.num_ports;
+       }
+
+       /* we didn't recognize the device */
+       dev_err(&serial->dev->dev,
+                "don't know the number of ports, assuming 1\n");
+
+       return 1;
+}
+
+static void qt2_set_termios(struct tty_struct *tty,
+                           struct usb_serial_port *port,
+                           struct ktermios *old_termios)
+{
+       struct usb_device *dev = port->serial->dev;
+       struct qt2_port_private *port_priv;
+       struct ktermios *termios = tty->termios;
+       u16 baud;
+       unsigned int cflag = termios->c_cflag;
+       u16 new_lcr = 0;
+       int status;
+
+       port_priv = usb_get_serial_port_data(port);
+
+       if (cflag & PARENB) {
+               if (cflag & PARODD)
+                       new_lcr |= UART_LCR_PARITY;
+               else
+                       new_lcr |= SERIAL_EVEN_PARITY;
+       }
+
+       switch (cflag & CSIZE) {
+       case CS5:
+               new_lcr |= UART_LCR_WLEN5;
+               break;
+       case CS6:
+               new_lcr |= UART_LCR_WLEN6;
+               break;
+       case CS7:
+               new_lcr |= UART_LCR_WLEN7;
+               break;
+       default:
+       case CS8:
+               new_lcr |= UART_LCR_WLEN8;
+               break;
+       }
+
+       baud = tty_get_baud_rate(tty);
+       if (!baud)
+               baud = 9600;
+
+       status = qt2_set_port_config(dev, port_priv->device_port, baud,
+                                    new_lcr);
+       if (status < 0)
+               dev_err(&port->dev, "%s - qt2_set_port_config failed: %i\n",
+                       __func__, status);
+
+       if (cflag & CRTSCTS)
+               status = qt2_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
+                                        SERIAL_CRTSCTS,
+                                        port_priv->device_port);
+       else
+               status = qt2_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
+                                        0, port_priv->device_port);
+       if (status < 0)
+               dev_err(&port->dev, "%s - set HW flow control failed: %i\n",
+                       __func__, status);
+
+       if (I_IXOFF(tty) || I_IXON(tty)) {
+               u16 x = ((u16) (START_CHAR(tty) << 8) | (u16) (STOP_CHAR(tty)));
+
+               status = qt2_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
+                                        x, port_priv->device_port);
+       } else
+               status = qt2_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
+                                        0, port_priv->device_port);
+
+       if (status < 0)
+               dev_err(&port->dev, "%s - set SW flow control failed: %i\n",
+                       __func__, status);
+
+}
+
+static int qt2_open(struct tty_struct *tty, struct usb_serial_port *port)
+{
+       struct usb_serial *serial;
+       struct qt2_serial_private *serial_priv;
+       struct qt2_port_private *port_priv;
+       u8 *data;
+       u16 device_port;
+       int status;
+       unsigned long flags;
+
+       device_port = (u16) (port->number - port->serial->minor);
+
+       serial = port->serial;
+
+       port_priv = usb_get_serial_port_data(port);
+       serial_priv = usb_get_serial_data(serial);
+
+       /* set the port to RS232 mode */
+       status = qt2_control_msg(serial->dev, QT2_GET_SET_QMCR,
+                                QT2_QMCR_RS232, device_port);
+       if (status < 0) {
+               dev_err(&port->dev,
+                       "%s failed to set RS232 mode for port %i error %i\n",
+                       __func__, device_port, status);
+               return status;
+       }
+
+       data = kzalloc(2, GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       /* open the port */
+       status = usb_control_msg(serial->dev,
+                                usb_rcvctrlpipe(serial->dev, 0),
+                                QT_OPEN_CLOSE_CHANNEL,
+                                0xc0, 0,
+                                device_port, data, 2, QT2_USB_TIMEOUT);
+
+       if (status < 0) {
+               dev_err(&port->dev, "%s - open port failed %i", __func__,
+                       status);
+               kfree(data);
+               return status;
+       }
+
+       spin_lock_irqsave(&port_priv->lock, flags);
+       port_priv->shadowLSR = data[0];
+       port_priv->shadowMSR = data[1];
+       spin_unlock_irqrestore(&port_priv->lock, flags);
+
+       kfree(data);
+
+       /* set to default speed and 8bit word size */
+       status = qt2_set_port_config(serial->dev, device_port,
+                                    DEFAULT_BAUD_RATE, UART_LCR_WLEN8);
+       if (status < 0) {
+               dev_err(&port->dev,
+                       "%s - initial setup failed for port %i (%i)\n",
+                       __func__, port->number, device_port);
+               return status;
+       }
+
+       port_priv->is_open = true;
+       port_priv->device_port = (u8) device_port;
+
+       if (tty)
+               qt2_set_termios(tty, port, tty->termios);
+
+       return 0;
+
+}
+
+static void qt2_close(struct usb_serial_port *port)
+{
+       struct usb_serial *serial;
+       struct qt2_serial_private *serial_priv;
+       struct qt2_port_private *port_priv;
+       unsigned long flags;
+       int i;
+
+       serial = port->serial;
+       serial_priv = usb_get_serial_data(serial);
+       port_priv = usb_get_serial_port_data(port);
+
+       port_priv->is_open = false;
+
+       spin_lock_irqsave(&port_priv->urb_lock, flags);
+       if (port_priv->write_urb->status == -EINPROGRESS)
+               usb_kill_urb(port_priv->write_urb);
+       port_priv->urb_in_use = false;
+       spin_unlock_irqrestore(&port_priv->urb_lock, flags);
+
+       /* flush the port transmit buffer */
+       i = usb_control_msg(serial->dev,
+                           usb_rcvctrlpipe(serial->dev, 0),
+                           QT2_FLUSH_DEVICE, 0x40, 1,
+                           port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
+
+       if (i < 0)
+               dev_err(&port->dev, "%s - transmit buffer flush failed: %i\n",
+                       __func__, i);
+
+       /* flush the port receive buffer */
+       i = usb_control_msg(serial->dev,
+                           usb_rcvctrlpipe(serial->dev, 0),
+                           QT2_FLUSH_DEVICE, 0x40, 0,
+                           port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
+
+       if (i < 0)
+               dev_err(&port->dev, "%s - receive buffer flush failed: %i\n",
+                       __func__, i);
+
+       /* close the port */
+       i = usb_control_msg(serial->dev,
+                           usb_sndctrlpipe(serial->dev, 0),
+                           QT_OPEN_CLOSE_CHANNEL,
+                           0x40, 0,
+                           port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
+
+       if (i < 0)
+               dev_err(&port->dev, "%s - close port failed %i\n",
+                       __func__, i);
+
+}
+
+static void qt2_disconnect(struct usb_serial *serial)
+{
+       struct qt2_serial_private *serial_priv = usb_get_serial_data(serial);
+       struct qt2_port_private *port_priv;
+       int i;
+
+       if (serial_priv->read_urb->status == -EINPROGRESS)
+               usb_kill_urb(serial_priv->read_urb);
+
+       usb_free_urb(serial_priv->read_urb);
+
+       for (i = 0; i < serial->num_ports; i++) {
+               port_priv = usb_get_serial_port_data(serial->port[i]);
+
+               if (port_priv->write_urb->status == -EINPROGRESS)
+                       usb_kill_urb(port_priv->write_urb);
+               usb_free_urb(port_priv->write_urb);
+       }
+}
+
+static int get_serial_info(struct usb_serial_port *port,
+                          struct serial_struct __user *retinfo)
+{
+       struct serial_struct tmp;
+
+       if (!retinfo)
+               return -EFAULT;
+
+       memset(&tmp, 0, sizeof(tmp));
+       tmp.line                = port->serial->minor;
+       tmp.port                = 0;
+       tmp.irq                 = 0;
+       tmp.flags               = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
+       tmp.xmit_fifo_size      = port->bulk_out_size;
+       tmp.baud_base           = 9600;
+       tmp.close_delay         = 5*HZ;
+       tmp.closing_wait        = 30*HZ;
+
+       if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
+               return -EFAULT;
+       return 0;
+}
+
+static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
+{
+       struct qt2_port_private *priv = usb_get_serial_port_data(port);
+       struct async_icount prev, cur;
+       unsigned long flags;
+
+       spin_lock_irqsave(&priv->lock, flags);
+       prev = priv->icount;
+       spin_unlock_irqrestore(&priv->lock, flags);
+
+       while (1) {
+               wait_event_interruptible(priv->delta_msr_wait,
+                                        ((priv->icount.rng != prev.rng) ||
+                                         (priv->icount.dsr != prev.dsr) ||
+                                         (priv->icount.dcd != prev.dcd) ||
+                                         (priv->icount.cts != prev.cts)));
+
+               if (signal_pending(current))
+                       return -ERESTARTSYS;
+
+               spin_lock_irqsave(&priv->lock, flags);
+               cur = priv->icount;
+               spin_unlock_irqrestore(&priv->lock, flags);
+
+               if ((prev.rng == cur.rng) &&
+                   (prev.dsr == cur.dsr) &&
+                   (prev.dcd == cur.dcd) &&
+                   (prev.cts == cur.cts))
+                       return -EIO;
+
+               if ((arg & TIOCM_RNG && (prev.rng != cur.rng)) ||
+                   (arg & TIOCM_DSR && (prev.dsr != cur.dsr)) ||
+                   (arg & TIOCM_CD && (prev.dcd != cur.dcd)) ||
+                   (arg & TIOCM_CTS && (prev.cts != cur.cts)))
+                       return 0;
+       }
+       return 0;
+}
+
+static int qt2_get_icount(struct tty_struct *tty,
+                         struct serial_icounter_struct *icount)
+{
+       struct usb_serial_port *port = tty->driver_data;
+       struct qt2_port_private *priv = usb_get_serial_port_data(port);
+       struct async_icount cnow = priv->icount;
+
+       icount->cts = cnow.cts;
+       icount->dsr = cnow.dsr;
+       icount->rng = cnow.rng;
+       icount->dcd = cnow.dcd;
+       icount->rx = cnow.rx;
+       icount->tx = cnow.tx;
+       icount->frame = cnow.frame;
+       icount->overrun = cnow.overrun;
+       icount->parity = cnow.parity;
+       icount->brk = cnow.brk;
+       icount->buf_overrun = cnow.buf_overrun;
+
+       return 0;
+}
+
+static int qt2_ioctl(struct tty_struct *tty,
+                    unsigned int cmd, unsigned long arg)
+{
+       struct usb_serial_port *port = tty->driver_data;
+
+       switch (cmd) {
+       case TIOCGSERIAL:
+               return get_serial_info(port,
+                                      (struct serial_struct __user *)arg);
+
+       case TIOCMIWAIT:
+               return wait_modem_info(port, arg);
+
+       default:
+               break;
+       }
+
+       return -ENOIOCTLCMD;
+}
+
+static void qt2_process_status(struct usb_serial_port *port, unsigned char *ch)
+{
+       switch (*ch) {
+       case QT2_LINE_STATUS:
+               qt2_update_lsr(port, ch + 1);
+               break;
+       case QT2_MODEM_STATUS:
+               qt2_update_msr(port, ch + 1);
+               break;
+       }
+}
+
+/* not needed, kept to document functionality */
+static void qt2_process_xmit_empty(struct usb_serial_port *port,
+                                  unsigned char *ch)
+{
+       int bytes_written;
+
+       bytes_written = (int)(*ch) + (int)(*(ch + 1) << 4);
+}
+
+/* not needed, kept to document functionality */
+static void qt2_process_flush(struct usb_serial_port *port, unsigned char *ch)
+{
+       return;
+}
+
+void qt2_process_read_urb(struct urb *urb)
+{
+       struct usb_serial *serial;
+       struct qt2_serial_private *serial_priv;
+       struct usb_serial_port *port;
+       struct qt2_port_private *port_priv;
+       struct tty_struct *tty;
+       bool escapeflag;
+       unsigned char *ch;
+       int i;
+       unsigned char newport;
+       int len = urb->actual_length;
+
+       if (!len)
+               return;
+
+       ch = urb->transfer_buffer;
+       tty = NULL;
+       serial = urb->context;
+       serial_priv = usb_get_serial_data(serial);
+       port = serial->port[serial_priv->current_port];
+       port_priv = usb_get_serial_port_data(port);
+
+       if (port_priv->is_open)
+               tty = tty_port_tty_get(&port->port);
+
+       for (i = 0; i < urb->actual_length; i++) {
+               ch = (unsigned char *)urb->transfer_buffer + i;
+               if ((i <= (len - 3)) &&
+                   (*ch == QT2_CONTROL_BYTE) &&
+                   (*(ch + 1) == QT2_CONTROL_BYTE)) {
+                       escapeflag = false;
+                       switch (*(ch + 2)) {
+                       case QT2_LINE_STATUS:
+                       case QT2_MODEM_STATUS:
+                               if (i > (len - 4)) {
+                                       dev_warn(&port->dev,
+                                                "%s - status message too short\n",
+                                               __func__);
+                                       break;
+                               }
+                               qt2_process_status(port, ch + 2);
+                               i += 3;
+                               escapeflag = true;
+                               break;
+                       case QT2_XMIT_HOLD:
+                               if (i > (len - 5)) {
+                                       dev_warn(&port->dev,
+                                                "%s - xmit_empty message too short\n",
+                                                __func__);
+                                       break;
+                               }
+                               qt2_process_xmit_empty(port, ch + 3);
+                               i += 4;
+                               escapeflag = true;
+                               break;
+                       case QT2_CHANGE_PORT:
+                               if (i > (len - 4)) {
+                                       dev_warn(&port->dev,
+                                                "%s - change_port message too short\n",
+                                                __func__);
+                                       break;
+                               }
+                               if (tty) {
+                                       tty_flip_buffer_push(tty);
+                                       tty_kref_put(tty);
+                               }
+
+                               newport = *(ch + 3);
+
+                               if (newport > serial->num_ports) {
+                                       dev_err(&port->dev,
+                                               "%s - port change to invalid port: %i\n",
+                                               __func__, newport);
+                                       break;
+                               }
+
+                               serial_priv->current_port = newport;
+                               port = serial->port[serial_priv->current_port];
+                               port_priv = usb_get_serial_port_data(port);
+                               if (port_priv->is_open)
+                                       tty = tty_port_tty_get(&port->port);
+                               else
+                                       tty = NULL;
+                               i += 3;
+                               escapeflag = true;
+                               break;
+                       case QT2_REC_FLUSH:
+                       case QT2_XMIT_FLUSH:
+                               qt2_process_flush(port, ch + 2);
+                               i += 2;
+                               escapeflag = true;
+                               break;
+                       case QT2_CONTROL_ESCAPE:
+                               tty_buffer_request_room(tty, 2);
+                               tty_insert_flip_string(tty, ch, 2);
+                               i += 2;
+                               escapeflag = true;
+                               break;
+                       default:
+                               dev_warn(&port->dev,
+                                        "%s - unsupported command %i\n",
+                                        __func__, *(ch + 2));
+                               break;
+                       }
+                       if (escapeflag)
+                               continue;
+               }
+
+               if (tty) {
+                       tty_buffer_request_room(tty, 1);
+                       tty_insert_flip_string(tty, ch, 1);
+               }
+       }
+
+       if (tty) {
+               tty_flip_buffer_push(tty);
+               tty_kref_put(tty);
+       }
+}
+
+static void qt2_write_bulk_callback(struct urb *urb)
+{
+       struct usb_serial_port *port;
+       struct qt2_port_private *port_priv;
+
+       port = urb->context;
+       port_priv = usb_get_serial_port_data(port);
+
+       spin_lock(&port_priv->urb_lock);
+
+       port_priv->urb_in_use = false;
+       usb_serial_port_softint(port);
+
+       spin_unlock(&port_priv->urb_lock);
+
+}
+
+static void qt2_read_bulk_callback(struct urb *urb)
+{
+       struct usb_serial *serial = urb->context;
+       int status;
+
+       if (urb->status) {
+               dev_warn(&serial->dev->dev,
+                        "%s - non-zero urb status: %i\n", __func__,
+                        urb->status);
+               return;
+       }
+
+       qt2_process_read_urb(urb);
+
+       status = usb_submit_urb(urb, GFP_ATOMIC);
+       if (status != 0)
+               dev_err(&serial->dev->dev,
+                       "%s - resubmit read urb failed: %i\n",
+                       __func__, status);
+}
+
+static int qt2_setup_urbs(struct usb_serial *serial)
+{
+       struct usb_serial_port *port;
+       struct usb_serial_port *port0;
+       struct qt2_serial_private *serial_priv;
+       struct qt2_port_private *port_priv;
+       int pcount, status;
+
+       port0 = serial->port[0];
+
+       serial_priv = usb_get_serial_data(serial);
+       serial_priv->read_urb = usb_alloc_urb(0, GFP_KERNEL);
+       if (!serial_priv->read_urb) {
+               dev_err(&serial->dev->dev, "No free urbs available\n");
+               return -ENOMEM;
+       }
+
+       usb_fill_bulk_urb(serial_priv->read_urb, serial->dev,
+                         usb_rcvbulkpipe(serial->dev,
+                                         port0->bulk_in_endpointAddress),
+                         serial_priv->read_buffer,
+                         sizeof(serial_priv->read_buffer),
+                         qt2_read_bulk_callback, serial);
+
+       /* setup write_urb for each port */
+       for (pcount = 0; pcount < serial->num_ports; pcount++) {
+
+               port = serial->port[pcount];
+               port_priv = usb_get_serial_port_data(port);
+
+               port_priv->write_urb = usb_alloc_urb(0, GFP_KERNEL);
+               if (!port_priv->write_urb) {
+                       dev_err(&serial->dev->dev,
+                               "failed to alloc write_urb for port %i\n",
+                               pcount);
+                       return -ENOMEM;
+               }
+
+               usb_fill_bulk_urb(port_priv->write_urb,
+                                 serial->dev,
+                                 usb_sndbulkpipe(serial->dev,
+                                                 port0->
+                                                 bulk_out_endpointAddress),
+                                 port_priv->write_buffer,
+                                 sizeof(port_priv->write_buffer),
+                                 qt2_write_bulk_callback, port);
+       }
+
+       status = usb_submit_urb(serial_priv->read_urb, GFP_KERNEL);
+       if (status != 0) {
+               dev_err(&serial->dev->dev,
+                       "%s - submit read urb failed %i\n", __func__, status);
+               return status;
+       }
+
+       return 0;
+
+}
+
+static int qt2_attach(struct usb_serial *serial)
+{
+       struct qt2_serial_private *serial_priv;
+       struct qt2_port_private *port_priv;
+       int status, pcount;
+
+       /* power on unit */
+       status = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
+                                0xc2, 0x40, 0x8000, 0, NULL, 0,
+                                QT2_USB_TIMEOUT);
+       if (status < 0) {
+               dev_err(&serial->dev->dev,
+                       "%s - failed to power on unit: %i\n", __func__, status);
+               return status;
+       }
+
+       serial_priv = kzalloc(sizeof(*serial_priv), GFP_KERNEL);
+       if (!serial_priv) {
+               dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
+               return -ENOMEM;
+       }
+
+       usb_set_serial_data(serial, serial_priv);
+
+       for (pcount = 0; pcount < serial->num_ports; pcount++) {
+               port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL);
+               if (!port_priv) {
+                       dev_err(&serial->dev->dev,
+                               "%s- kmalloc(%Zd) failed.\n", __func__,
+                               sizeof(*port_priv));
+                       pcount--;
+                       status = -ENOMEM;
+                       goto attach_failed;
+               }
+
+               spin_lock_init(&port_priv->lock);
+               spin_lock_init(&port_priv->urb_lock);
+               init_waitqueue_head(&port_priv->delta_msr_wait);
+
+               port_priv->port = serial->port[pcount];
+
+               usb_set_serial_port_data(serial->port[pcount], port_priv);
+       }
+
+       status = qt2_setup_urbs(serial);
+       if (status != 0)
+               goto attach_failed;
+
+       return 0;
+
+attach_failed:
+       for (/* empty */; pcount >= 0; pcount--) {
+               port_priv = usb_get_serial_port_data(serial->port[pcount]);
+               kfree(port_priv);
+       }
+       kfree(serial_priv);
+       return status;
+}
+
+static int qt2_tiocmget(struct tty_struct *tty)
+{
+       struct usb_serial_port *port = tty->driver_data;
+       struct usb_device *dev = port->serial->dev;
+       struct qt2_port_private *port_priv = usb_get_serial_port_data(port);
+       u8 *d;
+       int r;
+
+       d = kzalloc(2, GFP_KERNEL);
+       if (!d)
+               return -ENOMEM;
+
+       r = qt2_getregister(dev, port_priv->device_port, UART_MCR, d);
+       if (r < 0)
+               goto mget_out;
+
+       r = qt2_getregister(dev, port_priv->device_port, UART_MSR, d + 1);
+       if (r < 0)
+               goto mget_out;
+
+       r = (d[0] & UART_MCR_DTR ? TIOCM_DTR : 0) |
+           (d[0] & UART_MCR_RTS ? TIOCM_RTS : 0) |
+           (d[1] & UART_MSR_CTS ? TIOCM_CTS : 0) |
+           (d[1] & UART_MSR_DCD ? TIOCM_CAR : 0) |
+           (d[1] & UART_MSR_RI ? TIOCM_RI : 0) |
+           (d[1] & UART_MSR_DSR ? TIOCM_DSR : 0);
+
+mget_out:
+       kfree(d);
+       return r;
+}
+
+static int qt2_tiocmset(struct tty_struct *tty,
+                       unsigned int set, unsigned int clear)
+{
+       struct qt2_port_private *port_priv;
+
+       port_priv = usb_get_serial_port_data(tty->driver_data);
+       return update_mctrl(port_priv, set, clear);
+}
+
+static void qt2_break_ctl(struct tty_struct *tty, int break_state)
+{
+       struct usb_serial_port *port = tty->driver_data;
+       struct qt2_port_private *port_priv;
+       int status;
+       u16 val;
+
+       port_priv = usb_get_serial_port_data(port);
+
+       if (!port_priv->is_open) {
+               dev_err(&port->dev,
+                       "%s - port is not open\n", __func__);
+               return;
+       }
+
+       val = (break_state == -1) ? 1 : 0;
+
+       status = qt2_control_msg(port->serial->dev, QT2_BREAK_CONTROL,
+                                val, port_priv->device_port);
+       if (status < 0)
+               dev_warn(&port->dev,
+                        "%s - failed to send control message: %i\n", __func__,
+                        status);
+}
+
+
+
+static void qt2_dtr_rts(struct usb_serial_port *port, int on)
+{
+       struct usb_device *dev = port->serial->dev;
+       struct qt2_port_private *port_priv = usb_get_serial_port_data(port);
+
+       mutex_lock(&port->serial->disc_mutex);
+       if (!port->serial->disconnected) {
+               /* Disable flow control */
+               if (!on && qt2_setregister(dev, port_priv->device_port,
+                                          UART_MCR, 0) < 0)
+                       dev_warn(&port->dev, "error from flowcontrol urb\n");
+               /* drop RTS and DTR */
+               if (on)
+                       update_mctrl(port_priv, TIOCM_DTR | TIOCM_RTS, 0);
+               else
+                       update_mctrl(port_priv, 0, TIOCM_DTR | TIOCM_RTS);
+       }
+       mutex_unlock(&port->serial->disc_mutex);
+}
+
+static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch)
+{
+       struct qt2_port_private *port_priv;
+       u8 newMSR = (u8) *ch;
+       unsigned long flags;
+
+       port_priv = usb_get_serial_port_data(port);
+
+       spin_lock_irqsave(&port_priv->lock, flags);
+       port_priv->shadowMSR = newMSR;
+       spin_unlock_irqrestore(&port_priv->lock, flags);
+
+       if (newMSR & UART_MSR_ANY_DELTA) {
+               /* update input line counters */
+               if (newMSR & UART_MSR_DCTS)
+                       port_priv->icount.cts++;
+
+               if (newMSR & UART_MSR_DDSR)
+                       port_priv->icount.dsr++;
+
+               if (newMSR & UART_MSR_DDCD)
+                       port_priv->icount.dcd++;
+
+               if (newMSR & UART_MSR_TERI)
+                       port_priv->icount.rng++;
+
+               wake_up_interruptible(&port_priv->delta_msr_wait);
+       }
+}
+
+static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch)
+{
+       struct qt2_port_private *port_priv;
+       struct async_icount *icount;
+       unsigned long flags;
+       u8 newLSR = (u8) *ch;
+
+       port_priv = usb_get_serial_port_data(port);
+
+       if (newLSR & UART_LSR_BI)
+               newLSR &= (u8) (UART_LSR_OE | UART_LSR_BI);
+
+       spin_lock_irqsave(&port_priv->lock, flags);
+       port_priv->shadowLSR = newLSR;
+       spin_unlock_irqrestore(&port_priv->lock, flags);
+
+       icount = &port_priv->icount;
+
+       if (newLSR & UART_LSR_BRK_ERROR_BITS) {
+
+               if (newLSR & UART_LSR_BI)
+                       icount->brk++;
+
+               if (newLSR & UART_LSR_OE)
+                       icount->overrun++;
+
+               if (newLSR & UART_LSR_PE)
+                       icount->parity++;
+
+               if (newLSR & UART_LSR_FE)
+                       icount->frame++;
+       }
+
+}
+
+static int qt2_write_room(struct tty_struct *tty)
+{
+       struct usb_serial_port *port = tty->driver_data;
+       struct qt2_port_private *port_priv;
+       unsigned long flags = 0;
+       int r;
+
+       port_priv = usb_get_serial_port_data(port);
+
+       spin_lock_irqsave(&port_priv->urb_lock, flags);
+
+       if (port_priv->urb_in_use)
+               r = 0;
+       else
+               r = QT2_WRITE_BUFFER_SIZE - QT2_WRITE_CONTROL_SIZE;
+
+       spin_unlock_irqrestore(&port_priv->urb_lock, flags);
+
+       return r;
+}
+
+static int qt2_write(struct tty_struct *tty,
+                    struct usb_serial_port *port,
+                    const unsigned char *buf, int count)
+{
+       struct qt2_port_private *port_priv;
+       struct urb *write_urb;
+       unsigned char *data;
+       unsigned long flags;
+       int status;
+       int bytes_out = 0;
+
+       port_priv = usb_get_serial_port_data(port);
+
+       if (port_priv->write_urb == NULL) {
+               dev_err(&port->dev, "%s - no output urb\n", __func__);
+               return 0;
+       }
+       write_urb = port_priv->write_urb;
+
+       count = min(count, QT2_WRITE_BUFFER_SIZE - QT2_WRITE_CONTROL_SIZE);
+
+       data = write_urb->transfer_buffer;
+       spin_lock_irqsave(&port_priv->urb_lock, flags);
+       if (port_priv->urb_in_use == true) {
+               printk(KERN_INFO "qt2_write - urb is in use\n");
+               goto write_out;
+       }
+
+       *data++ = QT2_CONTROL_BYTE;
+       *data++ = QT2_CONTROL_BYTE;
+       *data++ = port_priv->device_port;
+       put_unaligned_le16(count, data);
+       data += 2;
+       memcpy(data, buf, count);
+
+       write_urb->transfer_buffer_length = count + QT2_WRITE_CONTROL_SIZE;
+
+       status = usb_submit_urb(write_urb, GFP_ATOMIC);
+       if (status == 0) {
+               port_priv->urb_in_use = true;
+               bytes_out += count;
+       }
+
+write_out:
+       spin_unlock_irqrestore(&port_priv->urb_lock, flags);
+       return bytes_out;
+}
+
+
+static struct usb_serial_driver qt2_device = {
+       .driver = {
+               .owner = THIS_MODULE,
+               .name = "quatech-serial",
+       },
+       .description         = DRIVER_DESC,
+       .id_table            = id_table,
+       .open                = qt2_open,
+       .close               = qt2_close,
+       .write               = qt2_write,
+       .write_room          = qt2_write_room,
+       .calc_num_ports      = qt2_calc_num_ports,
+       .attach              = qt2_attach,
+       .release             = qt2_release,
+       .disconnect          = qt2_disconnect,
+       .dtr_rts             = qt2_dtr_rts,
+       .break_ctl           = qt2_break_ctl,
+       .tiocmget            = qt2_tiocmget,
+       .tiocmset            = qt2_tiocmset,
+       .get_icount          = qt2_get_icount,
+       .ioctl               = qt2_ioctl,
+       .set_termios         = qt2_set_termios,
+};
+
+static struct usb_serial_driver *const serial_drivers[] = {
+       &qt2_device, NULL
+};
+
+module_usb_serial_driver(serial_drivers, id_table);
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+
+module_param(debug, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Debug enabled or not");