Logo Search packages:      
Sourcecode: linux version File versions  Download package

cypress_m8.c

/*
 * USB Cypress M8 driver
 *
 *    Copyright (C) 2004
 *        Lonnie Mendez (dignome@gmail.com) 
 *    Copyright (C) 2003,2004
 *        Neil Whelchel (koyama@firstlight.net)
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    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 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.
 *
 *  Lonnie Mendez <dignome@gmail.com>
 *  12-15-2004
 *    Incorporated write buffering from pl2303 driver.  Fixed bug with line
 *    handling so both lines are raised in cypress_open. (was dropping rts)
 *      Various code cleanups made as well along with other misc bug fixes.
 *
 *  Lonnie Mendez <dignome@gmail.com>
 *  04-10-2004
 *    Driver modified to support dynamic line settings.  Various improvments
 *      and features.
 *
 *  Neil Whelchel
 *  10-2003
 *    Driver first released.
 *
 */

/* 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. */


#include <linux/kernel.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/moduleparam.h>
#include <linux/spinlock.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/serial.h>
#include <linux/delay.h>
#include <asm/uaccess.h>

#include "cypress_m8.h"


#ifdef CONFIG_USB_SERIAL_DEBUG
      static int debug = 1;
#else
      static int debug;
#endif
static int stats;
static int interval;

/*
 * Version Information
 */
#define DRIVER_VERSION "v1.09"
#define DRIVER_AUTHOR "Lonnie Mendez <dignome@gmail.com>, Neil Whelchel <koyama@firstlight.net>"
#define DRIVER_DESC "Cypress USB to Serial Driver"

/* write buffer size defines */
#define CYPRESS_BUF_SIZE      1024
#define CYPRESS_CLOSING_WAIT  (30*HZ)

static struct usb_device_id id_table_earthmate [] = {
      { USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
      { USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
      { }                                 /* Terminating entry */
};

static struct usb_device_id id_table_cyphidcomrs232 [] = {
      { USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
      { }                                 /* Terminating entry */
};

static struct usb_device_id id_table_nokiaca42v2 [] = {
      { USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
      { }                                 /* Terminating entry */
};

static struct usb_device_id id_table_combined [] = {
      { USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
      { USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
      { USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
      { USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
      { }                                 /* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, id_table_combined);

static struct usb_driver cypress_driver = {
      .name =           "cypress",
      .probe =    usb_serial_probe,
      .disconnect =     usb_serial_disconnect,
      .id_table = id_table_combined,
      .no_dynamic_id =  1,
};

struct cypress_private {
      spinlock_t lock;           /* private lock */
      int chiptype;                    /* identifier of device, for quirks/etc */
      int bytes_in;                    /* used for statistics */
      int bytes_out;                   /* used for statistics */
      int cmd_count;                   /* used for statistics */
      int cmd_ctrl;                    /* always set this to 1 before issuing a command */
      struct cypress_buf *buf;         /* write buffer */
      int write_urb_in_use;            /* write urb in use indicator */
      int write_urb_interval;            /* interval to use for write urb */
      int read_urb_interval;             /* interval to use for read urb */
      int comm_is_ok;                    /* true if communication is (still) ok */
      int termios_initialized;
      __u8 line_control;               /* holds dtr / rts value */
      __u8 current_status;             /* received from last read - info on dsr,cts,cd,ri,etc */
      __u8 current_config;             /* stores the current configuration byte */
      __u8 rx_flags;                   /* throttling - used from whiteheat/ftdi_sio */
      int baud_rate;                   /* stores current baud rate in integer form */
      int cbr_mask;                    /* stores current baud rate in masked 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 */
      struct ktermios tmp_termios;     /* stores the old termios settings */
};

/* write buffer structure */
struct cypress_buf {
      unsigned int      buf_size;
      char        *buf_buf;
      char        *buf_get;
      char        *buf_put;
};

/* 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);
/* baud helper functions */
static int   mask_to_rate           (unsigned mask);
static unsigned  rate_to_mask       (int rate);
/* 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 struct usb_serial_driver cypress_earthmate_device = {
      .driver = {
            .owner =          THIS_MODULE,
            .name =                 "earthmate",
      },
      .description =                "DeLorme Earthmate USB",
      .usb_driver =                 &cypress_driver,
      .id_table =             id_table_earthmate,
      .num_interrupt_in =           1,
      .num_interrupt_out =          1,
      .num_bulk_in =                NUM_DONT_CARE,
      .num_bulk_out =               NUM_DONT_CARE,
      .num_ports =                  1,
      .attach =               cypress_earthmate_startup,
      .shutdown =             cypress_shutdown,
      .open =                       cypress_open,
      .close =                cypress_close,
      .write =                cypress_write,
      .write_room =                 cypress_write_room,
      .ioctl =                cypress_ioctl,
      .set_termios =                cypress_set_termios,
      .tiocmget =             cypress_tiocmget,
      .tiocmset =             cypress_tiocmset,
      .chars_in_buffer =            cypress_chars_in_buffer,
      .throttle =             cypress_throttle,
      .unthrottle =                 cypress_unthrottle,
      .read_int_callback =          cypress_read_int_callback,
      .write_int_callback =         cypress_write_int_callback,
};

static struct usb_serial_driver cypress_hidcom_device = {
      .driver = {
            .owner =          THIS_MODULE,
            .name =                 "cyphidcom",
      },
      .description =                "HID->COM RS232 Adapter",
      .usb_driver =                 &cypress_driver,
      .id_table =             id_table_cyphidcomrs232,
      .num_interrupt_in =           1,
      .num_interrupt_out =          1,
      .num_bulk_in =                NUM_DONT_CARE,
      .num_bulk_out =               NUM_DONT_CARE,
      .num_ports =                  1,
      .attach =               cypress_hidcom_startup,
      .shutdown =             cypress_shutdown,
      .open =                       cypress_open,
      .close =                cypress_close,
      .write =                cypress_write,
      .write_room =                 cypress_write_room,
      .ioctl =                cypress_ioctl,
      .set_termios =                cypress_set_termios,
      .tiocmget =             cypress_tiocmget,
      .tiocmset =             cypress_tiocmset,
      .chars_in_buffer =            cypress_chars_in_buffer,
      .throttle =             cypress_throttle,
      .unthrottle =                 cypress_unthrottle,
      .read_int_callback =          cypress_read_int_callback,
      .write_int_callback =         cypress_write_int_callback,
};

static struct usb_serial_driver cypress_ca42v2_device = {
      .driver = {
            .owner =          THIS_MODULE,
                .name =             "nokiaca42v2",
      },
      .description =                "Nokia CA-42 V2 Adapter",
      .usb_driver =                 &cypress_driver,
      .id_table =             id_table_nokiaca42v2,
      .num_interrupt_in =           1,
      .num_interrupt_out =          1,
      .num_bulk_in =                NUM_DONT_CARE,
      .num_bulk_out =               NUM_DONT_CARE,
      .num_ports =                  1,
      .attach =               cypress_ca42v2_startup,
      .shutdown =             cypress_shutdown,
      .open =                       cypress_open,
      .close =                cypress_close,
      .write =                cypress_write,
      .write_room =                 cypress_write_room,
      .ioctl =                cypress_ioctl,
      .set_termios =                cypress_set_termios,
      .tiocmget =             cypress_tiocmget,
      .tiocmset =             cypress_tiocmset,
      .chars_in_buffer =            cypress_chars_in_buffer,
      .throttle =             cypress_throttle,
      .unthrottle =                 cypress_unthrottle,
      .read_int_callback =          cypress_read_int_callback,
      .write_int_callback =         cypress_write_int_callback,
};

/*****************************************************************************
 * Cypress serial helper functions
 *****************************************************************************/


/* This function can either set or retrieve the current serial line settings */
static int cypress_serial_control (struct usb_serial_port *port, unsigned baud_mask, 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;
      __u8 feature_buffer[8];
      unsigned long flags;

      dbg("%s", __FUNCTION__);
      
      priv = usb_get_serial_port_data(port);

      if (!priv->comm_is_ok)
            return -ENODEV;

      switch(cypress_request_type) {
            case CYPRESS_SET_CONFIG:

                  /*
                   * The general purpose firmware for the Cypress M8 allows for a maximum speed
                   * of 57600bps (I have no idea whether DeLorme chose to use the general purpose
                   * firmware or not), if you need to modify this speed setting for your own
                   * project please add your own chiptype and modify the code likewise.  The
                   * Cypress HID->COM device will work successfully up to 115200bps (but the
                   * actual throughput is around 3kBps).
                   */
                  if (baud_mask != priv->cbr_mask) {
                        dbg("%s - baud rate is changing", __FUNCTION__);
                        if ( priv->chiptype == CT_EARTHMATE ) {
                              /* 300 and 600 baud rates are supported under the generic firmware,
                               * but are not used with NMEA and SiRF protocols */
                              
                              if ( (baud_mask == B300) || (baud_mask == B600) ) {
                                    err("%s - failed setting baud rate, unsupported speed",
                                        __FUNCTION__);
                                    new_baudrate = priv->baud_rate;
                              } else if ( (new_baudrate = mask_to_rate(baud_mask)) == -1) {
                                    err("%s - failed setting baud rate, unsupported speed",
                                        __FUNCTION__);
                                    new_baudrate = priv->baud_rate;
                              }
                        } else if (priv->chiptype == CT_CYPHIDCOM) {
                              if ( (new_baudrate = mask_to_rate(baud_mask)) == -1) {
                                    err("%s - failed setting baud rate, unsupported speed",
                                        __FUNCTION__);
                                    new_baudrate = priv->baud_rate;
                              }
                        } else if (priv->chiptype == CT_CA42V2) {
                              if ( (new_baudrate = mask_to_rate(baud_mask)) == -1) {
                                    err("%s - failed setting baud rate, unsupported speed",
                                        __FUNCTION__);
                                    new_baudrate = priv->baud_rate;
                              }
                        } else if (priv->chiptype == CT_GENERIC) {
                              if ( (new_baudrate = mask_to_rate(baud_mask)) == -1) {
                                    err("%s - failed setting baud rate, unsupported speed",
                                        __FUNCTION__);
                                    new_baudrate = priv->baud_rate;
                              }
                        } else {
                              info("%s - please define your chiptype", __FUNCTION__);
                              new_baudrate = priv->baud_rate;
                        }
                  } else {  /* baud rate not changing, keep the old */
                        new_baudrate = priv->baud_rate;
                  }
                  dbg("%s - baud rate is being sent as %d", __FUNCTION__, new_baudrate);
                  
                  memset(feature_buffer, 0, 8);
                  /* 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:", __FUNCTION__);
                  dbg("%s - %02X - %02X - %02X - %02X - %02X", __FUNCTION__, 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, 8, 500);

                        if (tries++ >= 3)
                              break;

                  } while (retval != 8 && retval != -ENODEV);

                  if (retval != 8) {
                        err("%s - failed sending serial line settings - %d", __FUNCTION__, retval);
                        cypress_set_dead(port);
                  } else {
                        spin_lock_irqsave(&priv->lock, flags);
                        priv->baud_rate = new_baudrate;
                        priv->cbr_mask = baud_mask;
                        priv->current_config = feature_buffer[4];
                        spin_unlock_irqrestore(&priv->lock, flags);
                  }
            break;
            case CYPRESS_GET_CONFIG:
                  dbg("%s - retreiving serial line settings", __FUNCTION__);
                  /* set initial values in feature buffer */
                  memset(feature_buffer, 0, 8);

                  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, 8, 500);
                        
                        if (tries++ >= 3)
                              break;

                  } while (retval != 5 && retval != -ENODEV);

                  if (retval != 5) {
                        err("%s - failed to retrieve serial line settings - %d", __FUNCTION__, 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);
                        
                        if ( (priv->cbr_mask = rate_to_mask(priv->baud_rate)) == 0x40)
                              dbg("%s - failed setting the baud mask (not defined)", __FUNCTION__);
                        spin_unlock_irqrestore(&priv->lock, flags);
                  }
      }
      spin_lock_irqsave(&priv->lock, flags);
      ++priv->cmd_count;
      spin_unlock_irqrestore(&priv->lock, flags);

      return retval;
} /* cypress_serial_control */


static void cypress_set_dead(struct usb_serial_port *port)
{
      struct cypress_private *priv = usb_get_serial_port_data(port);
      unsigned long flags;

      spin_lock_irqsave(&priv->lock, flags);
      if (!priv->comm_is_ok) {
            spin_unlock_irqrestore(&priv->lock, flags);
            return;
      }
      priv->comm_is_ok = 0;
      spin_unlock_irqrestore(&priv->lock, flags);

      err("cypress_m8 suspending failing port %d - interval might be too short",
          port->number);
}


/* given a baud mask, it will return integer baud on success */
static int mask_to_rate (unsigned mask)
{
      int rate;

      switch (mask) {
            case B0: rate = 0; break;
            case B300: rate = 300; break;
            case B600: rate = 600; break;
            case B1200: rate = 1200; break;
            case B2400: rate = 2400; break;
            case B4800: rate = 4800; break;
            case B9600: rate = 9600; break;
            case B19200: rate = 19200; break;
            case B38400: rate = 38400; break;
            case B57600: rate = 57600; break;
            case B115200: rate = 115200; break;
            default: rate = -1;
      }

      return rate;
}


static unsigned rate_to_mask (int rate)
{
      unsigned mask;

      switch (rate) {
            case 0: mask = B0; break;
            case 300: mask = B300; break;
            case 600: mask = B600; break;
            case 1200: mask = B1200; break;
            case 2400: mask = B2400; break;
            case 4800: mask = B4800; break;
            case 9600: mask = B9600; break;
            case 19200: mask = B19200; break;
            case 38400: mask = B38400; break;
            case 57600: mask = B57600; break;
            case 115200: mask = B115200; break;
            default: mask = 0x40;
      }

      return mask;
}
/*****************************************************************************
 * Cypress serial driver functions
 *****************************************************************************/


static int generic_startup (struct usb_serial *serial)
{
      struct cypress_private *priv;
      struct usb_serial_port *port = serial->port[0];

      dbg("%s - port %d", __FUNCTION__, port->number);

      priv = kzalloc(sizeof (struct cypress_private), GFP_KERNEL);
      if (!priv)
            return -ENOMEM;

      priv->comm_is_ok = !0;
      spin_lock_init(&priv->lock);
      priv->buf = cypress_buf_alloc(CYPRESS_BUF_SIZE);
      if (priv->buf == NULL) {
            kfree(priv);
            return -ENOMEM;
      }
      init_waitqueue_head(&priv->delta_msr_wait);
      
      usb_reset_configuration (serial->dev);
      
      priv->cmd_ctrl = 0;
      priv->line_control = 0;
      priv->termios_initialized = 0;
      priv->rx_flags = 0;
      priv->cbr_mask = B300;
      if (interval > 0) {
            priv->write_urb_interval = interval;
            priv->read_urb_interval = interval;
            dbg("%s - port %d read & write intervals forced to %d",
                __FUNCTION__,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",
                __FUNCTION__,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)
{
      struct cypress_private *priv;

      dbg("%s", __FUNCTION__);

      if (generic_startup(serial)) {
            dbg("%s - Failed setting up port %d", __FUNCTION__,
                        serial->port[0]->number);
            return 1;
      }

      priv = usb_get_serial_port_data(serial->port[0]);
      priv->chiptype = CT_EARTHMATE;

      return 0;
} /* cypress_earthmate_startup */


static int cypress_hidcom_startup (struct usb_serial *serial)
{
      struct cypress_private *priv;

      dbg("%s", __FUNCTION__);

      if (generic_startup(serial)) {
            dbg("%s - Failed setting up port %d", __FUNCTION__,
                        serial->port[0]->number);
            return 1;
      }

      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)
{
      struct cypress_private *priv;

      dbg("%s", __FUNCTION__);

      if (generic_startup(serial)) {
            dbg("%s - Failed setting up port %d", __FUNCTION__,
                        serial->port[0]->number);
            return 1;
      }

      priv = usb_get_serial_port_data(serial->port[0]);
      priv->chiptype = CT_CA42V2;

      return 0;
} /* cypress_ca42v2_startup */


static void cypress_shutdown (struct usb_serial *serial)
{
      struct cypress_private *priv;

      dbg ("%s - port %d", __FUNCTION__, serial->port[0]->number);

      /* all open ports are closed at this point */

      priv = usb_get_serial_port_data(serial->port[0]);

      if (priv) {
            cypress_buf_free(priv->buf);
            kfree(priv);
            usb_set_serial_port_data(serial->port[0], NULL);
      }
}


static int cypress_open (struct usb_serial_port *port, struct file *filp)
{
      struct cypress_private *priv = usb_get_serial_port_data(port);
      struct usb_serial *serial = port->serial;
      unsigned long flags;
      int result = 0;

      dbg("%s - port %d", __FUNCTION__, port->number);

      if (!priv->comm_is_ok)
            return -EIO;

      /* clear halts before open */
      usb_clear_halt(serial->dev, 0x81);
      usb_clear_halt(serial->dev, 0x02);

      spin_lock_irqsave(&priv->lock, flags);
      /* reset read/write statistics */
      priv->bytes_in = 0;
      priv->bytes_out = 0;
      priv->cmd_count = 0;
      priv->rx_flags = 0;
      spin_unlock_irqrestore(&priv->lock, flags);

      /* setting to zero could cause data loss */
      port->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);

      if (result) {
            dev_err(&port->dev, "%s - failed setting the control lines - error %d\n", __FUNCTION__, result);
            return result;
      } else
            dbg("%s - success setting the control lines", __FUNCTION__);      

      cypress_set_termios(port, &priv->tmp_termios);

      /* setup the port and start reading from the device */
      if(!port->interrupt_in_urb){
            err("%s - interrupt_in_urb is empty!", __FUNCTION__);
            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,
            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", __FUNCTION__, result);
            cypress_set_dead(port);
      }

      return result;
} /* cypress_open */


static void cypress_close(struct usb_serial_port *port, struct file * filp)
{
      struct cypress_private *priv = usb_get_serial_port_data(port);
      unsigned int c_cflag;
      unsigned long flags;
      int bps;
      long timeout;
      wait_queue_t wait;

      dbg("%s - port %d", __FUNCTION__, port->number);

      /* wait for data to drain from buffer */
      spin_lock_irqsave(&priv->lock, flags);
      timeout = CYPRESS_CLOSING_WAIT;
      init_waitqueue_entry(&wait, current);
      add_wait_queue(&port->tty->write_wait, &wait);
      for (;;) {
            set_current_state(TASK_INTERRUPTIBLE);
            if (cypress_buf_data_avail(priv->buf) == 0
            || timeout == 0 || signal_pending(current)
            || !usb_get_intfdata(port->serial->interface))
                  break;
            spin_unlock_irqrestore(&priv->lock, flags);
            timeout = schedule_timeout(timeout);
            spin_lock_irqsave(&priv->lock, flags);
      }
      set_current_state(TASK_RUNNING);
      remove_wait_queue(&port->tty->write_wait, &wait);
      /* clear out any remaining data in the buffer */
      cypress_buf_clear(priv->buf);
      spin_unlock_irqrestore(&priv->lock, flags);
      
      /* 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);

      dbg("%s - stopping urbs", __FUNCTION__);
      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 (c_cflag & HUPCL) {
                  /* drop dtr and rts */
                  priv = usb_get_serial_port_data(port);
                  spin_lock_irqsave(&priv->lock, flags);
                  priv->line_control = 0;
                  priv->cmd_ctrl = 1;
                  spin_unlock_irqrestore(&priv->lock, flags);
                  cypress_write(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);
} /* cypress_close */


static int cypress_write(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", __FUNCTION__, port->number, count);

      /* line control commands, which need to be executed immediately,
         are not put into the buffer for obvious reasons.
       */
      if (priv->cmd_ctrl) {
            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);

finish:
      cypress_send(port);

      return count;
} /* cypress_write */


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", __FUNCTION__, port->number);
      dbg("%s - interrupt out size is %d", __FUNCTION__, port->interrupt_out_size);
      
      spin_lock_irqsave(&priv->lock, flags);
      if (priv->write_urb_in_use) {
            dbg("%s - can't write, urb in use", __FUNCTION__);
            spin_unlock_irqrestore(&priv->lock, flags);
            return;
      }
      spin_unlock_irqrestore(&priv->lock, flags);

      /* clear buffer */
      memset(port->interrupt_out_urb->transfer_buffer, 0, port->interrupt_out_size);

      spin_lock_irqsave(&priv->lock, flags);
      switch (port->interrupt_out_size) {
            case 32:
                  /* this is for the CY7C64013... */
                  offset = 2;
                  port->interrupt_out_buffer[0] = priv->line_control;
                  break;
            case 8:
                  /* this is for the CY7C63743... */
                  offset = 1;
                  port->interrupt_out_buffer[0] = priv->line_control;
                  break;
            default:
                  dbg("%s - wrong packet size", __FUNCTION__);
                  spin_unlock_irqrestore(&priv->lock, flags);
                  return;
      }

      if (priv->line_control & CONTROL_RESET)
            priv->line_control &= ~CONTROL_RESET;

      if (priv->cmd_ctrl) {
            priv->cmd_count++;
            dbg("%s - line control command being issued", __FUNCTION__);
            spin_unlock_irqrestore(&priv->lock, flags);
            goto send;
      } else
            spin_unlock_irqrestore(&priv->lock, flags);

      count = cypress_buf_get(priv->buf, &port->interrupt_out_buffer[offset],
                        port->interrupt_out_size-offset);

      if (count == 0) {
            return;
      }

      switch (port->interrupt_out_size) {
            case 32:
                  port->interrupt_out_buffer[1] = count;
                  break;
            case 8:
                  port->interrupt_out_buffer[0] |= count;
      }

      dbg("%s - count is %d", __FUNCTION__, count);

send:
      spin_lock_irqsave(&priv->lock, flags);
      priv->write_urb_in_use = 1;
      spin_unlock_irqrestore(&priv->lock, flags);

      if (priv->cmd_ctrl)
            actual_size = 1;
      else
            actual_size = count + (port->interrupt_out_size == 32 ? 2 : 1);
      
      usb_serial_debug_data(debug, &port->dev, __FUNCTION__, 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);
      if (result) {
            dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__,
                  result);
            priv->write_urb_in_use = 0;
            cypress_set_dead(port);
      }

      spin_lock_irqsave(&priv->lock, flags);
      if (priv->cmd_ctrl) {
            priv->cmd_ctrl = 0;
      }
      priv->bytes_out += count; /* do not count the line control and size bytes */
      spin_unlock_irqrestore(&priv->lock, flags);

      usb_serial_port_softint(port);
} /* cypress_send */


/* returns how much space is available in the soft buffer */
static int cypress_write_room(struct usb_serial_port *port)
{
      struct cypress_private *priv = usb_get_serial_port_data(port);
      int room = 0;
      unsigned long flags;

      dbg("%s - port %d", __FUNCTION__, port->number);

      spin_lock_irqsave(&priv->lock, flags);
      room = cypress_buf_space_avail(priv->buf);
      spin_unlock_irqrestore(&priv->lock, flags);

      dbg("%s - returns %d", __FUNCTION__, room);
      return room;
}


static int cypress_tiocmget (struct usb_serial_port *port, struct file *file)
{
      struct cypress_private *priv = usb_get_serial_port_data(port);
      __u8 status, control;
      unsigned int result = 0;
      unsigned long flags;
      
      dbg("%s - port %d", __FUNCTION__, port->number);

      spin_lock_irqsave(&priv->lock, flags);
      control = priv->line_control;
      status = priv->current_status;
      spin_unlock_irqrestore(&priv->lock, flags);

      result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
            | ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
            | ((status & UART_CTS)        ? TIOCM_CTS : 0)
            | ((status & UART_DSR)        ? TIOCM_DSR : 0)
            | ((status & UART_RI)         ? TIOCM_RI  : 0)
            | ((status & UART_CD)         ? TIOCM_CD  : 0);

      dbg("%s - result = %x", __FUNCTION__, result);

      return result;
}


static int cypress_tiocmset (struct usb_serial_port *port, struct file *file,
                         unsigned int set, unsigned int clear)
{
      struct cypress_private *priv = usb_get_serial_port_data(port);
      unsigned long flags;
      
      dbg("%s - port %d", __FUNCTION__, port->number);

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

      priv->cmd_ctrl = 1;
      return cypress_write(port, NULL, 0);
}


static int cypress_ioctl (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg)
{
      struct cypress_private *priv = usb_get_serial_port_data(port);

      dbg("%s - port %d, cmd 0x%.4x", __FUNCTION__, port->number, cmd);

      switch (cmd) {
            case TIOCGSERIAL:
                  if (copy_to_user((void __user *)arg, port->tty->termios, sizeof(struct ktermios))) {
                        return -EFAULT;
                  }
                  return (0);
                  break;
            case TIOCSSERIAL:
                  if (copy_from_user(port->tty->termios, (void __user *)arg, sizeof(struct ktermios))) {
                        return -EFAULT;
                  }
                  /* here we need to call cypress_set_termios to invoke the new settings */
                  cypress_set_termios(port, &priv->tmp_termios);
                  return (0);
                  break;
            /* 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;
      }

      dbg("%s - arg not supported - it was 0x%04x - check include/asm/ioctls.h", __FUNCTION__, cmd);

      return -ENOIOCTLCMD;
} /* cypress_ioctl */


static void cypress_set_termios (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, baud_mask;
      unsigned long flags;
      __u8 oldlines;
      int linechange = 0;

      dbg("%s - port %d", __FUNCTION__, port->number);

      tty = port->tty;
      if ((!tty) || (!tty->termios)) {
            dbg("%s - no tty structures", __FUNCTION__);
            return;
      }

      spin_lock_irqsave(&priv->lock, flags);
      if (!priv->termios_initialized) {
            if (priv->chiptype == CT_EARTHMATE) {
                  *(tty->termios) = tty_std_termios;
                  tty->termios->c_cflag = B4800 | CS8 | CREAD | HUPCL |
                        CLOCAL;
            } else if (priv->chiptype == CT_CYPHIDCOM) {
                  *(tty->termios) = tty_std_termios;
                  tty->termios->c_cflag = B9600 | CS8 | CREAD | HUPCL |
                        CLOCAL;
            } else if (priv->chiptype == CT_CA42V2) {
                  *(tty->termios) = tty_std_termios;
                  tty->termios->c_cflag = B9600 | CS8 | CREAD | HUPCL |
                        CLOCAL;
            }
            priv->termios_initialized = 1;
      }
      spin_unlock_irqrestore(&priv->lock, flags);

      cflag = tty->termios->c_cflag;
      iflag = tty->termios->c_iflag;

      /* check if there are new settings */
      if (old_termios) {
            if ((cflag != old_termios->c_cflag) ||
                  (RELEVANT_IFLAG(iflag) !=
                   RELEVANT_IFLAG(old_termios->c_iflag))) {
                  dbg("%s - attempting to set new termios settings",
                              __FUNCTION__);
                  /* should make a copy of this in case something goes
                   * wrong in the function, we can restore it */
                  spin_lock_irqsave(&priv->lock, flags);
                  priv->tmp_termios = *(tty->termios);
                  spin_unlock_irqrestore(&priv->lock, flags);
            } else {
                  dbg("%s - nothing to do, exiting", __FUNCTION__);
                  return;
            }
      } else
            return;

      /* set number of data bits, parity, stop bits */
      /* when parity is disabled the parity type bit is ignored */

      /* 1 means 2 stop bits, 0 means 1 stop bit */
      stop_bits = cflag & CSTOPB ? 1 : 0;

      if (cflag & PARENB) {
            parity_enable = 1;
            /* 1 means odd parity, 0 means even parity */
            parity_type = cflag & PARODD ? 1 : 0;
      } 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",
                                    __FUNCTION__);
                        data_bits = 3;
            }
      } else
            data_bits = 3;

      spin_lock_irqsave(&priv->lock, flags);
      oldlines = priv->line_control;
      if ((cflag & CBAUD) == B0) {
            /* drop dtr and rts */
            dbg("%s - dropping the lines, baud rate 0bps", __FUNCTION__);
            baud_mask = B0;
            priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
      } else {
            baud_mask = (cflag & CBAUD);
            switch(baud_mask) {
                  case B300:
                        dbg("%s - setting baud 300bps", __FUNCTION__);
                        break;
                  case B600:
                        dbg("%s - setting baud 600bps", __FUNCTION__);
                        break;
                  case B1200:
                        dbg("%s - setting baud 1200bps", __FUNCTION__);
                        break;
                  case B2400:
                        dbg("%s - setting baud 2400bps", __FUNCTION__);
                        break;
                  case B4800:
                        dbg("%s - setting baud 4800bps", __FUNCTION__);
                        break;
                  case B9600:
                        dbg("%s - setting baud 9600bps", __FUNCTION__);
                        break;
                  case B19200:
                        dbg("%s - setting baud 19200bps", __FUNCTION__);
                        break;
                  case B38400:
                        dbg("%s - setting baud 38400bps", __FUNCTION__);
                        break;
                  case B57600:
                        dbg("%s - setting baud 57600bps", __FUNCTION__);
                        break;
                  case B115200:
                        dbg("%s - setting baud 115200bps", __FUNCTION__);
                        break;
                  default:
                        dbg("%s - unknown masked baud rate", __FUNCTION__);
            }
            priv->line_control = (CONTROL_DTR | CONTROL_RTS);
      }
      spin_unlock_irqrestore(&priv->lock, flags);

      dbg("%s - sending %d stop_bits, %d parity_enable, %d parity_type, "
                  "%d data_bits (+5)", __FUNCTION__, stop_bits,
                  parity_enable, parity_type, data_bits);

      cypress_serial_control(port, baud_mask, 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);

      /* 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) ) {
            dbg("Using custom termios settings for a baud rate of "
                        "4800bps.");
            /* define custom termios settings for NMEA protocol */

            tty->termios->c_iflag /* input modes - */
                  &= ~(IGNBRK  /* disable ignore break */
                  | BRKINT     /* disable break causes interrupt */
                  | PARMRK     /* disable mark parity errors */
                  | ISTRIP     /* disable clear high bit of input char */
                  | INLCR      /* disable translate NL to CR */
                  | IGNCR      /* disable ignore CR */
                  | ICRNL      /* disable translate CR to NL */
                  | IXON);     /* disable enable XON/XOFF flow control */

            tty->termios->c_oflag /* output modes */
                  &= ~OPOST;    /* disable postprocess output char */

            tty->termios->c_lflag /* line discipline modes */
                  &= ~(ECHO     /* disable echo input characters */
                  | ECHONL      /* disable echo new line */
                  | ICANON      /* disable erase, kill, werase, and rprnt
                               special characters */
                  | ISIG        /* disable interrupt, quit, and suspend
                               special characters */
                  | IEXTEN);    /* disable non-POSIX special characters */
      } /* CT_CYPHIDCOM: Application should handle this for device */

      linechange = (priv->line_control != oldlines);
      spin_unlock_irqrestore(&priv->lock, flags);

      /* if necessary, set lines */
      if (linechange) {
            priv->cmd_ctrl = 1;
            cypress_write(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)
{
      struct cypress_private *priv = usb_get_serial_port_data(port);
      int chars = 0;
      unsigned long flags;

      dbg("%s - port %d", __FUNCTION__, port->number);
      
      spin_lock_irqsave(&priv->lock, flags);
      chars = cypress_buf_data_avail(priv->buf);
      spin_unlock_irqrestore(&priv->lock, flags);

      dbg("%s - returns %d", __FUNCTION__, chars);
      return chars;
}


static void cypress_throttle (struct usb_serial_port *port)
{
      struct cypress_private *priv = usb_get_serial_port_data(port);
      unsigned long flags;

      dbg("%s - port %d", __FUNCTION__, port->number);

      spin_lock_irqsave(&priv->lock, flags);
      priv->rx_flags = THROTTLED;
      spin_unlock_irqrestore(&priv->lock, flags);
}


static void cypress_unthrottle (struct usb_serial_port *port)
{
      struct cypress_private *priv = usb_get_serial_port_data(port);
      int actually_throttled, result;
      unsigned long flags;

      dbg("%s - port %d", __FUNCTION__, port->number);

      spin_lock_irqsave(&priv->lock, flags);
      actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
      priv->rx_flags = 0;
      spin_unlock_irqrestore(&priv->lock, flags);

      if (!priv->comm_is_ok)
            return;

      if (actually_throttled) {
            port->interrupt_in_urb->dev = port->serial->dev;

            result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
            if (result) {
                  dev_err(&port->dev, "%s - failed submitting read urb, "
                              "error %d\n", __FUNCTION__, result);
                  cypress_set_dead(port);
            }
      }
}


static void cypress_read_int_callback(struct urb *urb)
{
      struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
      struct cypress_private *priv = usb_get_serial_port_data(port);
      struct tty_struct *tty;
      unsigned char *data = urb->transfer_buffer;
      unsigned long flags;
      char tty_flag = TTY_NORMAL;
      int havedata = 0;
      int bytes = 0;
      int result;
      int i = 0;
      int status = urb->status;

      dbg("%s - port %d", __FUNCTION__, port->number);

      switch (status) {
      case 0: /* success */
            break;
      case -ECONNRESET:
      case -ENOENT:
      case -ESHUTDOWN:
            /* precursor to disconnect so just go away */
            return;
      case -EPIPE:
            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",
                  __FUNCTION__, status);
            cypress_set_dead(port);
            return;
      }

      spin_lock_irqsave(&priv->lock, flags);
      if (priv->rx_flags & THROTTLED) {
            dbg("%s - now throttling", __FUNCTION__);
            priv->rx_flags |= ACTUALLY_THROTTLED;
            spin_unlock_irqrestore(&priv->lock, flags);
            return;
      }
      spin_unlock_irqrestore(&priv->lock, flags);

      tty = port->tty;
      if (!tty) {
            dbg("%s - bad tty pointer - exiting", __FUNCTION__);
            return;
      }

      spin_lock_irqsave(&priv->lock, flags);
      switch(urb->actual_length) {
            case 32:
                  /* This is for the CY7C64013... */
                  priv->current_status = data[0] & 0xF8;
                  bytes = data[1] + 2;
                  i = 2;
                  if (bytes > 2)
                        havedata = 1;
                  break;
            case 8:
                  /* This is for the CY7C63743... */
                  priv->current_status = data[0] & 0xF8;
                  bytes = (data[0] & 0x07) + 1;
                  i = 1;
                  if (bytes > 1)
                        havedata = 1;
                  break;
            default:
                  dbg("%s - wrong packet size - received %d bytes",
                              __FUNCTION__, urb->actual_length);
                  spin_unlock_irqrestore(&priv->lock, flags);
                  goto continue_read;
      }
      spin_unlock_irqrestore(&priv->lock, flags);

      usb_serial_debug_data (debug, &port->dev, __FUNCTION__,
                  urb->actual_length, data);

      spin_lock_irqsave(&priv->lock, flags);
      /* check to see if status has changed */
      if (priv != NULL) {
            if (priv->current_status != priv->prev_status) {
                  priv->diff_status |= priv->current_status ^
                        priv->prev_status;
                  wake_up_interruptible(&priv->delta_msr_wait);
                  priv->prev_status = priv->current_status;
            }
      }
      spin_unlock_irqrestore(&priv->lock, flags);

      /* hangup, as defined in acm.c... this might be a bad place for it
       * though */
      if (tty && !(tty->termios->c_cflag & CLOCAL) &&
                  !(priv->current_status & UART_CD)) {
            dbg("%s - calling hangup", __FUNCTION__);
            tty_hangup(tty);
            goto continue_read;
      }

      /* There is one error bit... I'm assuming it is a parity error
       * indicator as the generic firmware will set this bit to 1 if a
       * parity error occurs.
       * I can not find reference to any other error events. */
      spin_lock_irqsave(&priv->lock, flags);
      if (priv->current_status & CYP_ERROR) {
            spin_unlock_irqrestore(&priv->lock, flags);
            tty_flag = TTY_PARITY;
            dbg("%s - Parity Error detected", __FUNCTION__);
      } else
            spin_unlock_irqrestore(&priv->lock, flags);

      /* process read if there is data other than line status */
      if (tty && (bytes > i)) {
            bytes = tty_buffer_request_room(tty, bytes);
            for (; i < bytes ; ++i) {
                  dbg("pushing byte number %d - %d - %c", i, data[i],
                              data[i]);
                  tty_insert_flip_char(tty, data[i], tty_flag);
            }
            tty_flip_buffer_push(port->tty);
      }

      spin_lock_irqsave(&priv->lock, flags);
      /* control and status byte(s) are also counted */
      priv->bytes_in += bytes;
      spin_unlock_irqrestore(&priv->lock, flags);

continue_read:

      /* Continue trying to always read... unless the port has closed. */

      if (port->open_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);
            result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
            if (result) {
                  dev_err(&urb->dev->dev, "%s - failed resubmitting "
                              "read urb, error %d\n", __FUNCTION__,
                              result);
                  cypress_set_dead(port);
            }
      }

      return;
} /* cypress_read_int_callback */


static void cypress_write_int_callback(struct urb *urb)
{
      struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
      struct cypress_private *priv = usb_get_serial_port_data(port);
      int result;
      int status = urb->status;

      dbg("%s - port %d", __FUNCTION__, port->number);

      switch (status) {
            case 0:
                  /* success */
                  break;
            case -ECONNRESET:
            case -ENOENT:
            case -ESHUTDOWN:
                  /* this urb is terminated, clean up */
                  dbg("%s - urb shutting down with status: %d",
                      __FUNCTION__, status);
                  priv->write_urb_in_use = 0;
                  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",
                      __FUNCTION__, 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",
                        __FUNCTION__, result);
                  cypress_set_dead(port);
                  break;
            default:
                  dev_err(&urb->dev->dev,"%s - unexpected nonzero write status received: %d\n",
                        __FUNCTION__, status);
                  cypress_set_dead(port);
                  break;
      }
      
      priv->write_urb_in_use = 0;
      
      /* send any buffered data */
      cypress_send(port);
}


/*****************************************************************************
 * Write buffer functions - buffering code from pl2303 used
 *****************************************************************************/

/*
 * cypress_buf_alloc
 *
 * Allocate a circular buffer and all associated memory.
 */

static struct cypress_buf *cypress_buf_alloc(unsigned int size)
{

      struct cypress_buf *cb;


      if (size == 0)
            return NULL;

      cb = kmalloc(sizeof(struct cypress_buf), GFP_KERNEL);
      if (cb == NULL)
            return NULL;

      cb->buf_buf = kmalloc(size, GFP_KERNEL);
      if (cb->buf_buf == NULL) {
            kfree(cb);
            return NULL;
      }

      cb->buf_size = size;
      cb->buf_get = cb->buf_put = cb->buf_buf;

      return cb;

}


/*
 * cypress_buf_free
 *
 * Free the buffer and all associated memory.
 */

static void cypress_buf_free(struct cypress_buf *cb)
{
      if (cb) {
            kfree(cb->buf_buf);
            kfree(cb);
      }
}


/*
 * cypress_buf_clear
 *
 * Clear out all data in the circular buffer.
 */

static void cypress_buf_clear(struct cypress_buf *cb)
{
      if (cb != NULL)
            cb->buf_get = cb->buf_put;
            /* equivalent to a get of all data available */
}


/*
 * cypress_buf_data_avail
 *
 * Return the number of bytes of data available in the circular
 * buffer.
 */

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);
      else
            return 0;
}


/*
 * cypress_buf_space_avail
 *
 * Return the number of bytes of space available in the circular
 * buffer.
 */

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);
      else
            return 0;
}


/*
 * cypress_buf_put
 *
 * Copy data data from a user buffer and put it into the circular buffer.
 * Restrict to the amount of space available.
 *
 * Return the number of bytes copied.
 */

static unsigned int cypress_buf_put(struct cypress_buf *cb, const char *buf,
      unsigned int count)
{

      unsigned int len;


      if (cb == NULL)
            return 0;

      len  = cypress_buf_space_avail(cb);
      if (count > len)
            count = len;

      if (count == 0)
            return 0;

      len = cb->buf_buf + cb->buf_size - cb->buf_put;
      if (count > len) {
            memcpy(cb->buf_put, buf, len);
            memcpy(cb->buf_buf, buf+len, count - len);
            cb->buf_put = cb->buf_buf + count - len;
      } else {
            memcpy(cb->buf_put, buf, count);
            if (count < len)
                  cb->buf_put += count;
            else /* count == len */
                  cb->buf_put = cb->buf_buf;
      }

      return count;

}


/*
 * cypress_buf_get
 *
 * Get data from the circular buffer and copy to the given buffer.
 * Restrict to the amount of data available.
 *
 * Return the number of bytes copied.
 */

static unsigned int cypress_buf_get(struct cypress_buf *cb, char *buf,
      unsigned int count)
{

      unsigned int len;


      if (cb == NULL)
            return 0;

      len = cypress_buf_data_avail(cb);
      if (count > len)
            count = len;

      if (count == 0)
            return 0;

      len = cb->buf_buf + cb->buf_size - cb->buf_get;
      if (count > len) {
            memcpy(buf, cb->buf_get, len);
            memcpy(buf+len, cb->buf_buf, count - len);
            cb->buf_get = cb->buf_buf + count - len;
      } else {
            memcpy(buf, cb->buf_get, count);
            if (count < len)
                  cb->buf_get += count;
            else /* count == len */
                  cb->buf_get = cb->buf_buf;
      }

      return count;

}

/*****************************************************************************
 * Module functions
 *****************************************************************************/

static int __init cypress_init(void)
{
      int retval;
      
      dbg("%s", __FUNCTION__);
      
      retval = usb_serial_register(&cypress_earthmate_device);
      if (retval)
            goto failed_em_register;
      retval = usb_serial_register(&cypress_hidcom_device);
      if (retval)
            goto failed_hidcom_register;
      retval = usb_serial_register(&cypress_ca42v2_device);
      if (retval)
            goto failed_ca42v2_register;
      retval = usb_register(&cypress_driver);
      if (retval)
            goto failed_usb_register;

      info(DRIVER_DESC " " DRIVER_VERSION);
      return 0;

failed_usb_register:
      usb_serial_deregister(&cypress_ca42v2_device);
failed_ca42v2_register:
      usb_serial_deregister(&cypress_hidcom_device);
failed_hidcom_register:
      usb_serial_deregister(&cypress_earthmate_device);
failed_em_register:
      return retval;
}


static void __exit cypress_exit (void)
{
      dbg("%s", __FUNCTION__);

      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_LICENSE("GPL");

module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");
module_param(stats, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(stats, "Enable statistics or not");
module_param(interval, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(interval, "Overrides interrupt interval");

Generated by  Doxygen 1.6.0   Back to index