]> pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - drivers/usb/serial/cypress_m8.c
hrtimer: convert kvm-ia64 to the new hrtimer apis
[linux-2.6-omap-h63xx.git] / drivers / usb / serial / cypress_m8.c
index 0230d3c0888af92e816d2d432f60a7171c4f547d..22837a3f2f899e963f0d944814d222bcd2e494f5 100644 (file)
@@ -2,7 +2,7 @@
  * USB Cypress M8 driver
  *
  *     Copyright (C) 2004
- *         Lonnie Mendez (dignome@gmail.com) 
+ *         Lonnie Mendez (dignome@gmail.com)
  *     Copyright (C) 2003,2004
  *         Neil Whelchel (koyama@firstlight.net)
  *
  *     the Free Software Foundation; either version 2 of the License, or
  *     (at your option) any later version.
  *
- * See Documentation/usb/usb-serial.txt for more information on using this driver
+ * See Documentation/usb/usb-serial.txt for more information on using this
+ * driver
  *
  * See http://geocities.com/i0xox0i for information on this driver and the
  * earthmate usb device.
  *
  *  Lonnie Mendez <dignome@gmail.com>
  *  4-29-2005
- *     Fixed problem where setting or retreiving the serial config would fail with
- *     EPIPE.  Removed CRTS toggling so the driver behaves more like other usbserial
- *     adapters.  Issued new interval of 1ms instead of the default 10ms.  As a
- *     result, transfer speed has been substantially increased.  From avg. 850bps to
- *     avg. 3300bps.  initial termios has also been modified.  Cleaned up code and
- *     formatting issues so it is more readable.  Replaced the C++ style comments.
+ *     Fixed problem where setting or retreiving the serial config would fail
+ *     with EPIPE.  Removed CRTS toggling so the driver behaves more like
+ *     other usbserial adapters.  Issued new interval of 1ms instead of the
+ *     default 10ms.  As a result, transfer speed has been substantially
+ *     increased from avg. 850bps to avg. 3300bps.  initial termios has also
+ *     been modified.  Cleaned up code and formatting issues so it is more
+ *     readable.  Replaced the C++ style comments.
  *
  *  Lonnie Mendez <dignome@gmail.com>
  *  12-15-2004
  *
  */
 
-/* Thanks to Neil Whelchel for writing the first cypress m8 implementation for linux. */
+/* Thanks to Neil Whelchel for writing the first cypress m8 implementation
+   for linux. */
 /* Thanks to cypress for providing references for the hid reports. */
 /* Thanks to Jiang Zhang for providing links and for general help. */
-/* Code originates and was built up from ftdi_sio, belkin, pl2303 and others. */
+/* Code originates and was built up from ftdi_sio, belkin, pl2303 and others.*/
 
 
 #include <linux/kernel.h>
@@ -62,7 +65,7 @@
 #include <linux/usb/serial.h>
 #include <linux/serial.h>
 #include <linux/delay.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
 
 #include "cypress_m8.h"
 
@@ -112,7 +115,7 @@ static struct usb_device_id id_table_combined [] = {
        { }                                             /* Terminating entry */
 };
 
-MODULE_DEVICE_TABLE (usb, id_table_combined);
+MODULE_DEVICE_TABLE(usb, id_table_combined);
 
 static struct usb_driver cypress_driver = {
        .name =         "cypress",
@@ -146,11 +149,13 @@ struct cypress_private {
        __u8 rx_flags;                     /* throttling - used from whiteheat/ftdi_sio */
        enum packet_format pkt_fmt;        /* format to use for packet send / receive */
        int get_cfg_unsafe;                /* If true, the CYPRESS_GET_CONFIG is unsafe */
-       int baud_rate;                     /* stores current baud rate in integer form */
+       int baud_rate;                     /* stores current baud rate in
+                                             integer form */
        int isthrottled;                   /* if throttled, discard reads */
        wait_queue_head_t delta_msr_wait;  /* used for TIOCMIWAIT */
        char prev_status, diff_status;     /* used for TIOCMIWAIT */
-       /* we pass a pointer to this as the arguement sent to cypress_set_termios old_termios */
+       /* we pass a pointer to this as the arguement sent to
+          cypress_set_termios old_termios */
        struct ktermios tmp_termios;       /* stores the old termios settings */
 };
 
@@ -163,33 +168,41 @@ struct cypress_buf {
 };
 
 /* function prototypes for the Cypress USB to serial device */
-static int  cypress_earthmate_startup  (struct usb_serial *serial);
-static int  cypress_hidcom_startup     (struct usb_serial *serial);
-static int  cypress_ca42v2_startup     (struct usb_serial *serial);
-static void cypress_shutdown           (struct usb_serial *serial);
-static int  cypress_open               (struct usb_serial_port *port, struct file *filp);
-static void cypress_close              (struct usb_serial_port *port, struct file *filp);
-static int  cypress_write              (struct usb_serial_port *port, const unsigned char *buf, int count);
-static void cypress_send               (struct usb_serial_port *port);
-static int  cypress_write_room         (struct usb_serial_port *port);
-static int  cypress_ioctl              (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg);
-static void cypress_set_termios                (struct usb_serial_port *port, struct ktermios * old);
-static int  cypress_tiocmget           (struct usb_serial_port *port, struct file *file);
-static int  cypress_tiocmset           (struct usb_serial_port *port, struct file *file, unsigned int set, unsigned int clear);
-static int  cypress_chars_in_buffer    (struct usb_serial_port *port);
-static void cypress_throttle           (struct usb_serial_port *port);
-static void cypress_unthrottle         (struct usb_serial_port *port);
-static void cypress_set_dead           (struct usb_serial_port *port);
-static void cypress_read_int_callback  (struct urb *urb);
-static void cypress_write_int_callback (struct urb *urb);
+static int  cypress_earthmate_startup(struct usb_serial *serial);
+static int  cypress_hidcom_startup(struct usb_serial *serial);
+static int  cypress_ca42v2_startup(struct usb_serial *serial);
+static void cypress_shutdown(struct usb_serial *serial);
+static int  cypress_open(struct tty_struct *tty,
+                       struct usb_serial_port *port, struct file *filp);
+static void cypress_close(struct tty_struct *tty,
+                       struct usb_serial_port *port, struct file *filp);
+static int  cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
+                       const unsigned char *buf, int count);
+static void cypress_send(struct usb_serial_port *port);
+static int  cypress_write_room(struct tty_struct *tty);
+static int  cypress_ioctl(struct tty_struct *tty, struct file *file,
+                       unsigned int cmd, unsigned long arg);
+static void cypress_set_termios(struct tty_struct *tty,
+                       struct usb_serial_port *port, struct ktermios *old);
+static int  cypress_tiocmget(struct tty_struct *tty, struct file *file);
+static int  cypress_tiocmset(struct tty_struct *tty, struct file *file,
+                       unsigned int set, unsigned int clear);
+static int  cypress_chars_in_buffer(struct tty_struct *tty);
+static void cypress_throttle(struct tty_struct *tty);
+static void cypress_unthrottle(struct tty_struct *tty);
+static void cypress_set_dead(struct usb_serial_port *port);
+static void cypress_read_int_callback(struct urb *urb);
+static void cypress_write_int_callback(struct urb *urb);
 /* write buffer functions */
 static struct cypress_buf *cypress_buf_alloc(unsigned int size);
-static void              cypress_buf_free(struct cypress_buf *cb);
-static void              cypress_buf_clear(struct cypress_buf *cb);
-static unsigned int      cypress_buf_data_avail(struct cypress_buf *cb);
-static unsigned int      cypress_buf_space_avail(struct cypress_buf *cb);
-static unsigned int      cypress_buf_put(struct cypress_buf *cb, const char *buf, unsigned int count);
-static unsigned int      cypress_buf_get(struct cypress_buf *cb, char *buf, unsigned int count);
+static void cypress_buf_free(struct cypress_buf *cb);
+static void cypress_buf_clear(struct cypress_buf *cb);
+static unsigned int cypress_buf_data_avail(struct cypress_buf *cb);
+static unsigned int cypress_buf_space_avail(struct cypress_buf *cb);
+static unsigned int cypress_buf_put(struct cypress_buf *cb,
+                                       const char *buf, unsigned int count);
+static unsigned int cypress_buf_get(struct cypress_buf *cb,
+                                       char *buf, unsigned int count);
 
 
 static struct usb_serial_driver cypress_earthmate_device = {
@@ -247,7 +260,7 @@ static struct usb_serial_driver cypress_hidcom_device = {
 static struct usb_serial_driver cypress_ca42v2_device = {
        .driver = {
                .owner =                THIS_MODULE,
-                .name =                        "nokiaca42v2",
+               .name =                 "nokiaca42v2",
        },
        .description =                  "Nokia CA-42 V2 Adapter",
        .usb_driver =                   &cypress_driver,
@@ -322,8 +335,10 @@ static int analyze_baud_rate(struct usb_serial_port *port, speed_t new_rate)
 
 
 /* This function can either set or retrieve the current serial line settings */
-static int cypress_serial_control (struct usb_serial_port *port, speed_t baud_rate, int data_bits, int stop_bits,
-                                  int parity_enable, int parity_type, int reset, int cypress_request_type)
+static int cypress_serial_control(struct tty_struct *tty,
+       struct usb_serial_port *port, speed_t baud_rate, int data_bits,
+       int stop_bits, int parity_enable, int parity_type, int reset,
+       int cypress_request_type)
 {
        int new_baudrate = 0, retval = 0, tries = 0;
        struct cypress_private *priv;
@@ -331,111 +346,114 @@ static int cypress_serial_control (struct usb_serial_port *port, speed_t baud_ra
        unsigned long flags;
 
        dbg("%s", __func__);
-       
+
        priv = usb_get_serial_port_data(port);
 
        if (!priv->comm_is_ok)
                return -ENODEV;
 
-       switch(cypress_request_type) {
-               case CYPRESS_SET_CONFIG:
+       switch (cypress_request_type) {
+       case CYPRESS_SET_CONFIG:
+               new_baudrate = priv->baud_rate;
+               /* 0 means 'Hang up' so doesn't change the true bit rate */
+               if (baud_rate == 0)
                        new_baudrate = priv->baud_rate;
-                       /* 0 means 'Hang up' so doesn't change the true bit rate */
-                       if (baud_rate == 0)
-                               new_baudrate = priv->baud_rate;
-                       /* Change of speed ? */
-                       else if (baud_rate != priv->baud_rate) {
-                               dbg("%s - baud rate is changing", __func__);
-                               retval = analyze_baud_rate(port, baud_rate);
-                               if (retval >=  0) {
-                                       new_baudrate = retval;
-                                       dbg("%s - New baud rate set to %d",
-                                           __func__, new_baudrate);
-                               }
-                       }
-                       dbg("%s - baud rate is being sent as %d", __func__, new_baudrate);
-                       
-                       memset(feature_buffer, 0, sizeof(feature_buffer));
-                       /* fill the feature_buffer with new configuration */
-                       *((u_int32_t *)feature_buffer) = new_baudrate;
-
-                       feature_buffer[4] |= data_bits;   /* assign data bits in 2 bit space ( max 3 ) */
-                       /* 1 bit gap */
-                       feature_buffer[4] |= (stop_bits << 3);   /* assign stop bits in 1 bit space */
-                       feature_buffer[4] |= (parity_enable << 4);   /* assign parity flag in 1 bit space */
-                       feature_buffer[4] |= (parity_type << 5);   /* assign parity type in 1 bit space */
-                       /* 1 bit gap */
-                       feature_buffer[4] |= (reset << 7);   /* assign reset at end of byte, 1 bit space */
-                               
-                       dbg("%s - device is being sent this feature report:", __func__);
-                       dbg("%s - %02X - %02X - %02X - %02X - %02X", __func__, feature_buffer[0], feature_buffer[1],
-                           feature_buffer[2], feature_buffer[3], feature_buffer[4]);
-                       
-                       do {
-                               retval = usb_control_msg(port->serial->dev,
-                                               usb_sndctrlpipe(port->serial->dev, 0),
-                                               HID_REQ_SET_REPORT,
-                                               USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
-                                               0x0300, 0, feature_buffer,
-                                               sizeof(feature_buffer), 500);
-
-                               if (tries++ >= 3)
-                                       break;
-
-                       } while (retval != sizeof(feature_buffer) &&
-                                retval != -ENODEV);
-
-                       if (retval != sizeof(feature_buffer)) {
-                               err("%s - failed sending serial line settings - %d", __func__, retval);
-                               cypress_set_dead(port);
-                       } else {
-                               spin_lock_irqsave(&priv->lock, flags);
-                               priv->baud_rate = new_baudrate;
-                               priv->current_config = feature_buffer[4];
-                               spin_unlock_irqrestore(&priv->lock, flags);
-                               /* If we asked for a speed change encode it */
-                               if (baud_rate)
-                                       tty_encode_baud_rate(port->tty,
-                                                       new_baudrate, new_baudrate);
-                       }
-               break;
-               case CYPRESS_GET_CONFIG:
-                       if (priv->get_cfg_unsafe) {
-                               /* Not implemented for this device,
-                                  and if we try to do it we're likely
-                                  to crash the hardware. */
-                               return -ENOTTY;
-                       }
-                       dbg("%s - retreiving serial line settings", __func__);
-                       /* set initial values in feature buffer */
-                       memset(feature_buffer, 0, sizeof(feature_buffer));
-
-                       do {
-                               retval = usb_control_msg(port->serial->dev,
-                                               usb_rcvctrlpipe(port->serial->dev, 0),
-                                               HID_REQ_GET_REPORT,
-                                               USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
-                                               0x0300, 0, feature_buffer,
-                                               sizeof(feature_buffer), 500);
-
-                               if (tries++ >= 3)
-                                       break;
-
-                       } while (retval != sizeof(feature_buffer) &&
-                                retval != -ENODEV);
-
-                       if (retval != sizeof(feature_buffer)) {
-                               err("%s - failed to retrieve serial line settings - %d", __func__, retval);
-                               cypress_set_dead(port);
-                               return retval;
-                       } else {
-                               spin_lock_irqsave(&priv->lock, flags);
-
-                               /* store the config in one byte, and later use bit masks to check values */
-                               priv->current_config = feature_buffer[4];
-                               priv->baud_rate = *((u_int32_t *)feature_buffer);
-                               spin_unlock_irqrestore(&priv->lock, flags);
+               /* Change of speed ? */
+               else if (baud_rate != priv->baud_rate) {
+                       dbg("%s - baud rate is changing", __func__);
+                       retval = analyze_baud_rate(port, baud_rate);
+                       if (retval >=  0) {
+                               new_baudrate = retval;
+                               dbg("%s - New baud rate set to %d",
+                                   __func__, new_baudrate);
                        }
+               }
+               dbg("%s - baud rate is being sent as %d",
+                                       __func__, new_baudrate);
+
+               memset(feature_buffer, 0, sizeof(feature_buffer));
+               /* fill the feature_buffer with new configuration */
+               *((u_int32_t *)feature_buffer) = new_baudrate;
+               feature_buffer[4] |= data_bits;   /* assign data bits in 2 bit space ( max 3 ) */
+               /* 1 bit gap */
+               feature_buffer[4] |= (stop_bits << 3);   /* assign stop bits in 1 bit space */
+               feature_buffer[4] |= (parity_enable << 4);   /* assign parity flag in 1 bit space */
+               feature_buffer[4] |= (parity_type << 5);   /* assign parity type in 1 bit space */
+               /* 1 bit gap */
+               feature_buffer[4] |= (reset << 7);   /* assign reset at end of byte, 1 bit space */
+
+               dbg("%s - device is being sent this feature report:",
+                                                               __func__);
+               dbg("%s - %02X - %02X - %02X - %02X - %02X", __func__,
+                       feature_buffer[0], feature_buffer[1],
+                       feature_buffer[2], feature_buffer[3],
+                       feature_buffer[4]);
+
+               do {
+                       retval = usb_control_msg(port->serial->dev,
+                                       usb_sndctrlpipe(port->serial->dev, 0),
+                                       HID_REQ_SET_REPORT,
+                                       USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
+                                       0x0300, 0, feature_buffer,
+                                       sizeof(feature_buffer), 500);
+
+                       if (tries++ >= 3)
+                               break;
+
+               } while (retval != sizeof(feature_buffer) &&
+                        retval != -ENODEV);
+
+               if (retval != sizeof(feature_buffer)) {
+                       err("%s - failed sending serial line settings - %d",
+                                                       __func__, retval);
+                       cypress_set_dead(port);
+               } else {
+                       spin_lock_irqsave(&priv->lock, flags);
+                       priv->baud_rate = new_baudrate;
+                       priv->current_config = feature_buffer[4];
+                       spin_unlock_irqrestore(&priv->lock, flags);
+                       /* If we asked for a speed change encode it */
+                       if (baud_rate)
+                               tty_encode_baud_rate(tty,
+                                       new_baudrate, new_baudrate);
+               }
+       break;
+       case CYPRESS_GET_CONFIG:
+               if (priv->get_cfg_unsafe) {
+                       /* Not implemented for this device,
+                          and if we try to do it we're likely
+                          to crash the hardware. */
+                       return -ENOTTY;
+               }
+               dbg("%s - retreiving serial line settings", __func__);
+               /* set initial values in feature buffer */
+               memset(feature_buffer, 0, sizeof(feature_buffer));
+
+               do {
+                       retval = usb_control_msg(port->serial->dev,
+                                       usb_rcvctrlpipe(port->serial->dev, 0),
+                                       HID_REQ_GET_REPORT,
+                                       USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
+                                       0x0300, 0, feature_buffer,
+                                       sizeof(feature_buffer), 500);
+
+                       if (tries++ >= 3)
+                               break;
+               } while (retval != sizeof(feature_buffer)
+                                               && retval != -ENODEV);
+
+               if (retval != sizeof(feature_buffer)) {
+                       err("%s - failed to retrieve serial line settings - %d", __func__, retval);
+                       cypress_set_dead(port);
+                       return retval;
+               } else {
+                       spin_lock_irqsave(&priv->lock, flags);
+                       /* store the config in one byte, and later
+                          use bit masks to check values */
+                       priv->current_config = feature_buffer[4];
+                       priv->baud_rate = *((u_int32_t *)feature_buffer);
+                       spin_unlock_irqrestore(&priv->lock, flags);
+               }
        }
        spin_lock_irqsave(&priv->lock, flags);
        ++priv->cmd_count;
@@ -468,14 +486,14 @@ static void cypress_set_dead(struct usb_serial_port *port)
  *****************************************************************************/
 
 
-static int generic_startup (struct usb_serial *serial)
+static int generic_startup(struct usb_serial *serial)
 {
        struct cypress_private *priv;
        struct usb_serial_port *port = serial->port[0];
 
        dbg("%s - port %d", __func__, port->number);
 
-       priv = kzalloc(sizeof (struct cypress_private), GFP_KERNEL);
+       priv = kzalloc(sizeof(struct cypress_private), GFP_KERNEL);
        if (!priv)
                return -ENOMEM;
 
@@ -487,9 +505,9 @@ static int generic_startup (struct usb_serial *serial)
                return -ENOMEM;
        }
        init_waitqueue_head(&priv->delta_msr_wait);
-       
-       usb_reset_configuration (serial->dev);
-       
+
+       usb_reset_configuration(serial->dev);
+
        priv->cmd_ctrl = 0;
        priv->line_control = 0;
        priv->termios_initialized = 0;
@@ -500,30 +518,30 @@ static int generic_startup (struct usb_serial *serial)
           small.  Otherwise we can use the slightly more compact
           format.  This is in accordance with the cypress_m8 serial
           converter app note. */
-       if (port->interrupt_out_size > 9) {
+       if (port->interrupt_out_size > 9)
                priv->pkt_fmt = packet_format_1;
-       } else {
+       else
                priv->pkt_fmt = packet_format_2;
-       }
+
        if (interval > 0) {
                priv->write_urb_interval = interval;
                priv->read_urb_interval = interval;
                dbg("%s - port %d read & write intervals forced to %d",
-                   __func__,port->number,interval);
+                   __func__, port->number, interval);
        } else {
                priv->write_urb_interval = port->interrupt_out_urb->interval;
                priv->read_urb_interval = port->interrupt_in_urb->interval;
                dbg("%s - port %d intervals: read=%d write=%d",
-                   __func__,port->number,
-                   priv->read_urb_interval,priv->write_urb_interval);
+                   __func__, port->number,
+                   priv->read_urb_interval, priv->write_urb_interval);
        }
        usb_set_serial_port_data(port, priv);
-       
+
        return 0;
 }
 
 
-static int cypress_earthmate_startup (struct usb_serial *serial)
+static int cypress_earthmate_startup(struct usb_serial *serial)
 {
        struct cypress_private *priv;
        struct usb_serial_port *port = serial->port[0];
@@ -541,7 +559,8 @@ static int cypress_earthmate_startup (struct usb_serial *serial)
        /* All Earthmate devices use the separated-count packet
           format!  Idiotic. */
        priv->pkt_fmt = packet_format_1;
-       if (serial->dev->descriptor.idProduct != cpu_to_le16(PRODUCT_ID_EARTHMATEUSB)) {
+       if (serial->dev->descriptor.idProduct !=
+                               cpu_to_le16(PRODUCT_ID_EARTHMATEUSB)) {
                /* The old original USB Earthmate seemed able to
                   handle GET_CONFIG requests; everything they've
                   produced since that time crashes if this command is
@@ -555,7 +574,7 @@ static int cypress_earthmate_startup (struct usb_serial *serial)
 } /* cypress_earthmate_startup */
 
 
-static int cypress_hidcom_startup (struct usb_serial *serial)
+static int cypress_hidcom_startup(struct usb_serial *serial)
 {
        struct cypress_private *priv;
 
@@ -569,12 +588,12 @@ static int cypress_hidcom_startup (struct usb_serial *serial)
 
        priv = usb_get_serial_port_data(serial->port[0]);
        priv->chiptype = CT_CYPHIDCOM;
-       
+
        return 0;
 } /* cypress_hidcom_startup */
 
 
-static int cypress_ca42v2_startup (struct usb_serial *serial)
+static int cypress_ca42v2_startup(struct usb_serial *serial)
 {
        struct cypress_private *priv;
 
@@ -593,11 +612,11 @@ static int cypress_ca42v2_startup (struct usb_serial *serial)
 } /* cypress_ca42v2_startup */
 
 
-static void cypress_shutdown (struct usb_serial *serial)
+static void cypress_shutdown(struct usb_serial *serial)
 {
        struct cypress_private *priv;
 
-       dbg ("%s - port %d", __func__, serial->port[0]->number);
+       dbg("%s - port %d", __func__, serial->port[0]->number);
 
        /* all open ports are closed at this point */
 
@@ -611,7 +630,8 @@ static void cypress_shutdown (struct usb_serial *serial)
 }
 
 
-static int cypress_open (struct usb_serial_port *port, struct file *filp)
+static int cypress_open(struct tty_struct *tty,
+                       struct usb_serial_port *port, struct file *filp)
 {
        struct cypress_private *priv = usb_get_serial_port_data(port);
        struct usb_serial *serial = port->serial;
@@ -636,37 +656,44 @@ static int cypress_open (struct usb_serial_port *port, struct file *filp)
        spin_unlock_irqrestore(&priv->lock, flags);
 
        /* setting to zero could cause data loss */
-       port->tty->low_latency = 1;
+       if (tty)
+               tty->low_latency = 1;
 
        /* raise both lines and set termios */
        spin_lock_irqsave(&priv->lock, flags);
        priv->line_control = CONTROL_DTR | CONTROL_RTS;
        priv->cmd_ctrl = 1;
        spin_unlock_irqrestore(&priv->lock, flags);
-       result = cypress_write(port, NULL, 0);
+       result = cypress_write(tty, port, NULL, 0);
 
        if (result) {
-               dev_err(&port->dev, "%s - failed setting the control lines - error %d\n", __func__, result);
+               dev_err(&port->dev,
+                       "%s - failed setting the control lines - error %d\n",
+                                                       __func__, result);
                return result;
        } else
                dbg("%s - success setting the control lines", __func__);
 
-       cypress_set_termios(port, &priv->tmp_termios);
+       if (tty)
+               cypress_set_termios(tty, port, &priv->tmp_termios);
 
        /* setup the port and start reading from the device */
-       if(!port->interrupt_in_urb){
+       if (!port->interrupt_in_urb) {
                err("%s - interrupt_in_urb is empty!", __func__);
-               return(-1);
+               return -1;
        }
 
        usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
                usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
-               port->interrupt_in_urb->transfer_buffer, port->interrupt_in_urb->transfer_buffer_length,
+               port->interrupt_in_urb->transfer_buffer,
+               port->interrupt_in_urb->transfer_buffer_length,
                cypress_read_int_callback, port, priv->read_urb_interval);
        result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 
-       if (result){
-               dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __func__, result);
+       if (result) {
+               dev_err(&port->dev,
+                       "%s - failed submitting read urb, error %d\n",
+                                                       __func__, result);
                cypress_set_dead(port);
        }
 
@@ -674,7 +701,8 @@ static int cypress_open (struct usb_serial_port *port, struct file *filp)
 } /* cypress_open */
 
 
-static void cypress_close(struct usb_serial_port *port, struct file * filp)
+static void cypress_close(struct tty_struct *tty,
+                       struct usb_serial_port *port, struct file *filp)
 {
        struct cypress_private *priv = usb_get_serial_port_data(port);
        unsigned int c_cflag;
@@ -688,7 +716,7 @@ static void cypress_close(struct usb_serial_port *port, struct file * filp)
        spin_lock_irq(&priv->lock);
        timeout = CYPRESS_CLOSING_WAIT;
        init_waitqueue_entry(&wait, current);
-       add_wait_queue(&port->tty->write_wait, &wait);
+       add_wait_queue(&tty->write_wait, &wait);
        for (;;) {
                set_current_state(TASK_INTERRUPTIBLE);
                if (cypress_buf_data_avail(priv->buf) == 0
@@ -701,7 +729,7 @@ static void cypress_close(struct usb_serial_port *port, struct file * filp)
                spin_lock_irq(&priv->lock);
        }
        set_current_state(TASK_RUNNING);
-       remove_wait_queue(&port->tty->write_wait, &wait);
+       remove_wait_queue(&tty->write_wait, &wait);
        /* clear out any remaining data in the buffer */
        cypress_buf_clear(priv->buf);
        spin_unlock_irq(&priv->lock);
@@ -713,19 +741,21 @@ static void cypress_close(struct usb_serial_port *port, struct file * filp)
                return;
        }
        /* wait for characters to drain from device */
-       bps = tty_get_baud_rate(port->tty);
-       if (bps > 1200)
-               timeout = max((HZ*2560)/bps,HZ/10);
-       else
-               timeout = 2*HZ;
-       schedule_timeout_interruptible(timeout);
+       if (tty) {
+               bps = tty_get_baud_rate(tty);
+               if (bps > 1200)
+                       timeout = max((HZ * 2560) / bps, HZ / 10);
+               else
+                       timeout = 2 * HZ;
+               schedule_timeout_interruptible(timeout);
+       }
 
        dbg("%s - stopping urbs", __func__);
-       usb_kill_urb (port->interrupt_in_urb);
-       usb_kill_urb (port->interrupt_out_urb);
+       usb_kill_urb(port->interrupt_in_urb);
+       usb_kill_urb(port->interrupt_out_urb);
 
-       if (port->tty) {
-               c_cflag = port->tty->termios->c_cflag;
+       if (tty) {
+               c_cflag = tty->termios->c_cflag;
                if (c_cflag & HUPCL) {
                        /* drop dtr and rts */
                        priv = usb_get_serial_port_data(port);
@@ -733,22 +763,23 @@ static void cypress_close(struct usb_serial_port *port, struct file * filp)
                        priv->line_control = 0;
                        priv->cmd_ctrl = 1;
                        spin_unlock_irq(&priv->lock);
-                       cypress_write(port, NULL, 0);
+                       cypress_write(tty, port, NULL, 0);
                }
        }
 
        if (stats)
-               dev_info (&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
-                         priv->bytes_in, priv->bytes_out, priv->cmd_count);
+               dev_info(&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
+                       priv->bytes_in, priv->bytes_out, priv->cmd_count);
        mutex_unlock(&port->serial->disc_mutex);
 } /* cypress_close */
 
 
-static int cypress_write(struct usb_serial_port *port, const unsigned char *buf, int count)
+static int cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
+                                       const unsigned char *buf, int count)
 {
        struct cypress_private *priv = usb_get_serial_port_data(port);
        unsigned long flags;
-       
+
        dbg("%s - port %d, %d bytes", __func__, port->number, count);
 
        /* line control commands, which need to be executed immediately,
@@ -758,10 +789,10 @@ static int cypress_write(struct usb_serial_port *port, const unsigned char *buf,
                count = 0;
                goto finish;
        }
-       
+
        if (!count)
                return count;
-       
+
        spin_lock_irqsave(&priv->lock, flags);
        count = cypress_buf_put(priv->buf, buf, count);
        spin_unlock_irqrestore(&priv->lock, flags);
@@ -778,13 +809,14 @@ static void cypress_send(struct usb_serial_port *port)
        int count = 0, result, offset, actual_size;
        struct cypress_private *priv = usb_get_serial_port_data(port);
        unsigned long flags;
-       
+
        if (!priv->comm_is_ok)
                return;
 
        dbg("%s - port %d", __func__, port->number);
-       dbg("%s - interrupt out size is %d", __func__, port->interrupt_out_size);
-       
+       dbg("%s - interrupt out size is %d", __func__,
+                                               port->interrupt_out_size);
+
        spin_lock_irqsave(&priv->lock, flags);
        if (priv->write_urb_in_use) {
                dbg("%s - can't write, urb in use", __func__);
@@ -794,7 +826,8 @@ static void cypress_send(struct usb_serial_port *port)
        spin_unlock_irqrestore(&priv->lock, flags);
 
        /* clear buffer */
-       memset(port->interrupt_out_urb->transfer_buffer, 0, port->interrupt_out_size);
+       memset(port->interrupt_out_urb->transfer_buffer, 0,
+                                               port->interrupt_out_size);
 
        spin_lock_irqsave(&priv->lock, flags);
        switch (priv->pkt_fmt) {
@@ -825,9 +858,8 @@ static void cypress_send(struct usb_serial_port *port)
        count = cypress_buf_get(priv->buf, &port->interrupt_out_buffer[offset],
                                port->interrupt_out_size-offset);
 
-       if (count == 0) {
+       if (count == 0)
                return;
-       }
 
        switch (priv->pkt_fmt) {
        default:
@@ -851,26 +883,29 @@ send:
                actual_size = count +
                              (priv->pkt_fmt == packet_format_1 ? 2 : 1);
 
-       usb_serial_debug_data(debug, &port->dev, __func__, port->interrupt_out_size,
-                             port->interrupt_out_urb->transfer_buffer);
+       usb_serial_debug_data(debug, &port->dev, __func__,
+               port->interrupt_out_size,
+               port->interrupt_out_urb->transfer_buffer);
 
        usb_fill_int_urb(port->interrupt_out_urb, port->serial->dev,
                usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
                port->interrupt_out_buffer, port->interrupt_out_size,
                cypress_write_int_callback, port, priv->write_urb_interval);
-       result = usb_submit_urb (port->interrupt_out_urb, GFP_ATOMIC);
+       result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
        if (result) {
-               dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __func__,
-                       result);
+               dev_err(&port->dev,
+                               "%s - failed submitting write urb, error %d\n",
+                                                       __func__, result);
                priv->write_urb_in_use = 0;
                cypress_set_dead(port);
        }
 
        spin_lock_irqsave(&priv->lock, flags);
-       if (priv->cmd_ctrl) {
+       if (priv->cmd_ctrl)
                priv->cmd_ctrl = 0;
-       }
-       priv->bytes_out += count; /* do not count the line control and size bytes */
+
+       /* do not count the line control and size bytes */
+       priv->bytes_out += count;
        spin_unlock_irqrestore(&priv->lock, flags);
 
        usb_serial_port_softint(port);
@@ -878,8 +913,9 @@ send:
 
 
 /* returns how much space is available in the soft buffer */
-static int cypress_write_room(struct usb_serial_port *port)
+static int cypress_write_room(struct tty_struct *tty)
 {
+       struct usb_serial_port *port = tty->driver_data;
        struct cypress_private *priv = usb_get_serial_port_data(port);
        int room = 0;
        unsigned long flags;
@@ -895,13 +931,14 @@ static int cypress_write_room(struct usb_serial_port *port)
 }
 
 
-static int cypress_tiocmget (struct usb_serial_port *port, struct file *file)
+static int cypress_tiocmget(struct tty_struct *tty, struct file *file)
 {
+       struct usb_serial_port *port = tty->driver_data;
        struct cypress_private *priv = usb_get_serial_port_data(port);
        __u8 status, control;
        unsigned int result = 0;
        unsigned long flags;
-       
+
        dbg("%s - port %d", __func__, port->number);
 
        spin_lock_irqsave(&priv->lock, flags);
@@ -922,12 +959,13 @@ static int cypress_tiocmget (struct usb_serial_port *port, struct file *file)
 }
 
 
-static int cypress_tiocmset (struct usb_serial_port *port, struct file *file,
+static int cypress_tiocmset(struct tty_struct *tty, struct file *file,
                               unsigned int set, unsigned int clear)
 {
+       struct usb_serial_port *port = tty->driver_data;
        struct cypress_private *priv = usb_get_serial_port_data(port);
        unsigned long flags;
-       
+
        dbg("%s - port %d", __func__, port->number);
 
        spin_lock_irqsave(&priv->lock, flags);
@@ -942,63 +980,60 @@ static int cypress_tiocmset (struct usb_serial_port *port, struct file *file,
        priv->cmd_ctrl = 1;
        spin_unlock_irqrestore(&priv->lock, flags);
 
-       return cypress_write(port, NULL, 0);
+       return cypress_write(tty, port, NULL, 0);
 }
 
 
-static int cypress_ioctl (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg)
+static int cypress_ioctl(struct tty_struct *tty, struct file *file,
+                                       unsigned int cmd, unsigned long arg)
 {
+       struct usb_serial_port *port = tty->driver_data;
        struct cypress_private *priv = usb_get_serial_port_data(port);
 
        dbg("%s - port %d, cmd 0x%.4x", __func__, port->number, cmd);
 
        switch (cmd) {
-               /* This code comes from drivers/char/serial.c and ftdi_sio.c */
-               case TIOCMIWAIT:
-                       while (priv != NULL) {
-                               interruptible_sleep_on(&priv->delta_msr_wait);
-                               /* see if a signal did it */
-                               if (signal_pending(current))
-                                       return -ERESTARTSYS;
-                               else {
-                                       char diff = priv->diff_status;
-
-                                       if (diff == 0) {
-                                               return -EIO; /* no change => error */
-                                       }
-                                       
-                                       /* consume all events */
-                                       priv->diff_status = 0;
-
-                                       /* return 0 if caller wanted to know about these bits */
-                                       if ( ((arg & TIOCM_RNG) && (diff & UART_RI)) ||
-                                            ((arg & TIOCM_DSR) && (diff & UART_DSR)) ||
-                                            ((arg & TIOCM_CD) && (diff & UART_CD)) ||
-                                            ((arg & TIOCM_CTS) && (diff & UART_CTS)) ) {
-                                               return 0;
-                                       }
-                                       /* otherwise caller can't care less about what happened,
-                                        * and so we continue to wait for more events.
-                                        */
-                               }
+       /* This code comes from drivers/char/serial.c and ftdi_sio.c */
+       case TIOCMIWAIT:
+               while (priv != NULL) {
+                       interruptible_sleep_on(&priv->delta_msr_wait);
+                       /* see if a signal did it */
+                       if (signal_pending(current))
+                               return -ERESTARTSYS;
+                       else {
+                               char diff = priv->diff_status;
+                               if (diff == 0)
+                                       return -EIO; /* no change => error */
+
+                               /* consume all events */
+                               priv->diff_status = 0;
+
+                               /* return 0 if caller wanted to know about
+                                  these bits */
+                               if (((arg & TIOCM_RNG) && (diff & UART_RI)) ||
+                                   ((arg & TIOCM_DSR) && (diff & UART_DSR)) ||
+                                   ((arg & TIOCM_CD) && (diff & UART_CD)) ||
+                                   ((arg & TIOCM_CTS) && (diff & UART_CTS)))
+                                       return 0;
+                               /* otherwise caller can't care less about what
+                                * happened, and so we continue to wait for
+                                * more events.
+                                */
                        }
-                       return 0;
-                       break;
-               default:
-                       break;
+               }
+               return 0;
+       default:
+               break;
        }
-
        dbg("%s - arg not supported - it was 0x%04x - check include/asm/ioctls.h", __func__, cmd);
-
        return -ENOIOCTLCMD;
 } /* cypress_ioctl */
 
 
-static void cypress_set_termios (struct usb_serial_port *port,
-               struct ktermios *old_termios)
+static void cypress_set_termios(struct tty_struct *tty,
+       struct usb_serial_port *port, struct ktermios *old_termios)
 {
        struct cypress_private *priv = usb_get_serial_port_data(port);
-       struct tty_struct *tty;
        int data_bits, stop_bits, parity_type, parity_enable;
        unsigned cflag, iflag;
        unsigned long flags;
@@ -1007,8 +1042,6 @@ static void cypress_set_termios (struct usb_serial_port *port,
 
        dbg("%s - port %d", __func__, port->number);
 
-       tty = port->tty;
-
        spin_lock_irqsave(&priv->lock, flags);
        if (!priv->termios_initialized) {
                if (priv->chiptype == CT_EARTHMATE) {
@@ -1060,28 +1093,24 @@ static void cypress_set_termios (struct usb_serial_port *port,
        } else
                parity_enable = parity_type = 0;
 
-       if (cflag & CSIZE) {
-               switch (cflag & CSIZE) {
-                       case CS5:
-                               data_bits = 0;
-                               break;
-                       case CS6:
-                               data_bits = 1;
-                               break;
-                       case CS7:
-                               data_bits = 2;
-                               break;
-                       case CS8:
-                               data_bits = 3;
-                               break;
-                       default:
-                               err("%s - CSIZE was set, but not CS5-CS8",
-                                               __func__);
-                               data_bits = 3;
-               }
-       } else
+       switch (cflag & CSIZE) {
+       case CS5:
+               data_bits = 0;
+               break;
+       case CS6:
+               data_bits = 1;
+               break;
+       case CS7:
+               data_bits = 2;
+               break;
+       case CS8:
                data_bits = 3;
-
+               break;
+       default:
+               err("%s - CSIZE was set, but not CS5-CS8",
+                               __func__);
+               data_bits = 3;
+       }
        spin_lock_irqsave(&priv->lock, flags);
        oldlines = priv->line_control;
        if ((cflag & CBAUD) == B0) {
@@ -1096,19 +1125,21 @@ static void cypress_set_termios (struct usb_serial_port *port,
                        "%d data_bits (+5)", __func__, stop_bits,
                        parity_enable, parity_type, data_bits);
 
-       cypress_serial_control(port, tty_get_baud_rate(tty), data_bits, stop_bits,
-                       parity_enable, parity_type, 0, CYPRESS_SET_CONFIG);
+       cypress_serial_control(tty, port, tty_get_baud_rate(tty),
+                       data_bits, stop_bits,
+                       parity_enable, parity_type,
+                       0, CYPRESS_SET_CONFIG);
 
        /* we perform a CYPRESS_GET_CONFIG so that the current settings are
         * filled into the private structure this should confirm that all is
         * working if it returns what we just set */
-       cypress_serial_control(port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
+       cypress_serial_control(tty, port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
 
        /* Here we can define custom tty settings for devices; the main tty
         * termios flag base comes from empeg.c */
 
        spin_lock_irqsave(&priv->lock, flags);
-       if ( (priv->chiptype == CT_EARTHMATE) && (priv->baud_rate == 4800) ) {
+       if (priv->chiptype == CT_EARTHMATE && priv->baud_rate == 4800) {
                dbg("Using custom termios settings for a baud rate of "
                                "4800bps.");
                /* define custom termios settings for NMEA protocol */
@@ -1142,20 +1173,21 @@ static void cypress_set_termios (struct usb_serial_port *port,
        /* if necessary, set lines */
        if (linechange) {
                priv->cmd_ctrl = 1;
-               cypress_write(port, NULL, 0);
+               cypress_write(tty, port, NULL, 0);
        }
 } /* cypress_set_termios */
 
 
 /* returns amount of data still left in soft buffer */
-static int cypress_chars_in_buffer(struct usb_serial_port *port)
+static int cypress_chars_in_buffer(struct tty_struct *tty)
 {
+       struct usb_serial_port *port = tty->driver_data;
        struct cypress_private *priv = usb_get_serial_port_data(port);
        int chars = 0;
        unsigned long flags;
 
        dbg("%s - port %d", __func__, port->number);
-       
+
        spin_lock_irqsave(&priv->lock, flags);
        chars = cypress_buf_data_avail(priv->buf);
        spin_unlock_irqrestore(&priv->lock, flags);
@@ -1165,8 +1197,9 @@ static int cypress_chars_in_buffer(struct usb_serial_port *port)
 }
 
 
-static void cypress_throttle (struct usb_serial_port *port)
+static void cypress_throttle(struct tty_struct *tty)
 {
+       struct usb_serial_port *port = tty->driver_data;
        struct cypress_private *priv = usb_get_serial_port_data(port);
        unsigned long flags;
 
@@ -1178,8 +1211,9 @@ static void cypress_throttle (struct usb_serial_port *port)
 }
 
 
-static void cypress_unthrottle (struct usb_serial_port *port)
+static void cypress_unthrottle(struct tty_struct *tty)
 {
+       struct usb_serial_port *port = tty->driver_data;
        struct cypress_private *priv = usb_get_serial_port_data(port);
        int actually_throttled, result;
        unsigned long flags;
@@ -1232,12 +1266,13 @@ static void cypress_read_int_callback(struct urb *urb)
                /* precursor to disconnect so just go away */
                return;
        case -EPIPE:
-               usb_clear_halt(port->serial->dev,0x81);
+               usb_clear_halt(port->serial->dev, 0x81);
                break;
        default:
                /* something ugly is going on... */
-               dev_err(&urb->dev->dev,"%s - unexpected nonzero read status received: %d\n",
-                       __func__, status);
+               dev_err(&urb->dev->dev,
+                       "%s - unexpected nonzero read status received: %d\n",
+                                                       __func__, status);
                cypress_set_dead(port);
                return;
        }
@@ -1251,7 +1286,7 @@ static void cypress_read_int_callback(struct urb *urb)
        }
        spin_unlock_irqrestore(&priv->lock, flags);
 
-       tty = port->tty;
+       tty = port->port.tty;
        if (!tty) {
                dbg("%s - bad tty pointer - exiting", __func__);
                return;
@@ -1285,8 +1320,8 @@ static void cypress_read_int_callback(struct urb *urb)
                goto continue_read;
        }
 
-       usb_serial_debug_data (debug, &port->dev, __func__,
-                       urb->actual_length, data);
+       usb_serial_debug_data(debug, &port->dev, __func__,
+                                               urb->actual_length, data);
 
        spin_lock_irqsave(&priv->lock, flags);
        /* check to see if status has changed */
@@ -1327,7 +1362,7 @@ static void cypress_read_int_callback(struct urb *urb)
                                        data[i]);
                        tty_insert_flip_char(tty, data[i], tty_flag);
                }
-               tty_flip_buffer_push(port->tty);
+               tty_flip_buffer_push(port->port.tty);
        }
 
        spin_lock_irqsave(&priv->lock, flags);
@@ -1339,13 +1374,14 @@ continue_read:
 
        /* Continue trying to always read... unless the port has closed. */
 
-       if (port->open_count > 0 && priv->comm_is_ok) {
+       if (port->port.count > 0 && priv->comm_is_ok) {
                usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
                                usb_rcvintpipe(port->serial->dev,
                                        port->interrupt_in_endpointAddress),
                                port->interrupt_in_urb->transfer_buffer,
                                port->interrupt_in_urb->transfer_buffer_length,
-                               cypress_read_int_callback, port, priv->read_urb_interval);
+                               cypress_read_int_callback, port,
+                               priv->read_urb_interval);
                result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
                if (result) {
                        dev_err(&urb->dev->dev, "%s - failed resubmitting "
@@ -1369,42 +1405,43 @@ static void cypress_write_int_callback(struct urb *urb)
        dbg("%s - port %d", __func__, port->number);
 
        switch (status) {
-               case 0:
-                       /* success */
+       case 0:
+               /* success */
+               break;
+       case -ECONNRESET:
+       case -ENOENT:
+       case -ESHUTDOWN:
+               /* this urb is terminated, clean up */
+               dbg("%s - urb shutting down with status: %d",
+                                               __func__, status);
+               priv->write_urb_in_use = 0;
+               return;
+       case -EPIPE: /* no break needed; clear halt and resubmit */
+               if (!priv->comm_is_ok)
                        break;
-               case -ECONNRESET:
-               case -ENOENT:
-               case -ESHUTDOWN:
-                       /* this urb is terminated, clean up */
-                       dbg("%s - urb shutting down with status: %d",
-                           __func__, status);
-                       priv->write_urb_in_use = 0;
+               usb_clear_halt(port->serial->dev, 0x02);
+               /* error in the urb, so we have to resubmit it */
+               dbg("%s - nonzero write bulk status received: %d",
+                       __func__, status);
+               port->interrupt_out_urb->transfer_buffer_length = 1;
+               port->interrupt_out_urb->dev = port->serial->dev;
+               result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
+               if (!result)
                        return;
-               case -EPIPE: /* no break needed; clear halt and resubmit */
-                       if (!priv->comm_is_ok)
-                               break;
-                       usb_clear_halt(port->serial->dev, 0x02);
-                       /* error in the urb, so we have to resubmit it */
-                       dbg("%s - nonzero write bulk status received: %d",
-                           __func__, status);
-                       port->interrupt_out_urb->transfer_buffer_length = 1;
-                       port->interrupt_out_urb->dev = port->serial->dev;
-                       result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
-                       if (!result)
-                               return;
-                       dev_err(&urb->dev->dev, "%s - failed resubmitting write urb, error %d\n",
-                               __func__, result);
-                       cypress_set_dead(port);
-                       break;
-               default:
-                       dev_err(&urb->dev->dev,"%s - unexpected nonzero write status received: %d\n",
-                               __func__, status);
-                       cypress_set_dead(port);
-                       break;
+               dev_err(&urb->dev->dev,
+                       "%s - failed resubmitting write urb, error %d\n",
+                                                       __func__, result);
+               cypress_set_dead(port);
+               break;
+       default:
+               dev_err(&urb->dev->dev,
+                        "%s - unexpected nonzero write status received: %d\n",
+                                                       __func__, status);
+               cypress_set_dead(port);
+               break;
        }
-       
        priv->write_urb_in_use = 0;
-       
+
        /* send any buffered data */
        cypress_send(port);
 }
@@ -1486,7 +1523,8 @@ static void cypress_buf_clear(struct cypress_buf *cb)
 static unsigned int cypress_buf_data_avail(struct cypress_buf *cb)
 {
        if (cb != NULL)
-               return ((cb->buf_size + cb->buf_put - cb->buf_get) % cb->buf_size);
+               return (cb->buf_size + cb->buf_put - cb->buf_get)
+                                                       % cb->buf_size;
        else
                return 0;
 }
@@ -1502,7 +1540,8 @@ static unsigned int cypress_buf_data_avail(struct cypress_buf *cb)
 static unsigned int cypress_buf_space_avail(struct cypress_buf *cb)
 {
        if (cb != NULL)
-               return ((cb->buf_size + cb->buf_get - cb->buf_put - 1) % cb->buf_size);
+               return (cb->buf_size + cb->buf_get - cb->buf_put - 1)
+                                                       % cb->buf_size;
        else
                return 0;
 }
@@ -1602,9 +1641,9 @@ static unsigned int cypress_buf_get(struct cypress_buf *cb, char *buf,
 static int __init cypress_init(void)
 {
        int retval;
-       
+
        dbg("%s", __func__);
-       
+
        retval = usb_serial_register(&cypress_earthmate_device);
        if (retval)
                goto failed_em_register;
@@ -1632,23 +1671,23 @@ failed_em_register:
 }
 
 
-static void __exit cypress_exit (void)
+static void __exit cypress_exit(void)
 {
        dbg("%s", __func__);
 
-       usb_deregister (&cypress_driver);
-       usb_serial_deregister (&cypress_earthmate_device);
-       usb_serial_deregister (&cypress_hidcom_device);
-       usb_serial_deregister (&cypress_ca42v2_device);
+       usb_deregister(&cypress_driver);
+       usb_serial_deregister(&cypress_earthmate_device);
+       usb_serial_deregister(&cypress_hidcom_device);
+       usb_serial_deregister(&cypress_ca42v2_device);
 }
 
 
 module_init(cypress_init);
 module_exit(cypress_exit);
 
-MODULE_AUTHOR( DRIVER_AUTHOR );
-MODULE_DESCRIPTION( DRIVER_DESC );
-MODULE_VERSION( DRIVER_VERSION );
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_VERSION(DRIVER_VERSION);
 MODULE_LICENSE("GPL");
 
 module_param(debug, bool, S_IRUGO | S_IWUSR);