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mos7840.c

/*
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Clean ups from Moschip version and a few ioctl implementations by:
 *    Paul B Schroeder <pschroeder "at" uplogix "dot" com>
 *
 * Originally based on drivers/usb/serial/io_edgeport.c which is:
 *      Copyright (C) 2000 Inside Out Networks, All rights reserved.
 *      Copyright (C) 2001-2002 Greg Kroah-Hartman <greg@kroah.com>
 *
 */

#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/serial.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <asm/uaccess.h>

/*
 * Version Information
 */
#define DRIVER_VERSION "1.3.1"
#define DRIVER_DESC "Moschip 7840/7820 USB Serial Driver"

/*
 * 16C50 UART register defines
 */

#define LCR_BITS_5             0x00 /* 5 bits/char */
#define LCR_BITS_6             0x01 /* 6 bits/char */
#define LCR_BITS_7             0x02 /* 7 bits/char */
#define LCR_BITS_8             0x03 /* 8 bits/char */
#define LCR_BITS_MASK          0x03 /* Mask for bits/char field */

#define LCR_STOP_1             0x00 /* 1 stop bit */
#define LCR_STOP_1_5           0x04 /* 1.5 stop bits (if 5   bits/char) */
#define LCR_STOP_2             0x04 /* 2 stop bits   (if 6-8 bits/char) */
#define LCR_STOP_MASK          0x04 /* Mask for stop bits field */

#define LCR_PAR_NONE           0x00 /* No parity */
#define LCR_PAR_ODD            0x08 /* Odd parity */
#define LCR_PAR_EVEN           0x18 /* Even parity */
#define LCR_PAR_MARK           0x28 /* Force parity bit to 1 */
#define LCR_PAR_SPACE          0x38 /* Force parity bit to 0 */
#define LCR_PAR_MASK           0x38 /* Mask for parity field */

#define LCR_SET_BREAK          0x40 /* Set Break condition */
#define LCR_DL_ENABLE          0x80 /* Enable access to divisor latch */

#define MCR_DTR                0x01 /* Assert DTR */
#define MCR_RTS                0x02 /* Assert RTS */
#define MCR_OUT1               0x04 /* Loopback only: Sets state of RI */
#define MCR_MASTER_IE          0x08 /* Enable interrupt outputs */
#define MCR_LOOPBACK           0x10 /* Set internal (digital) loopback mode */
#define MCR_XON_ANY            0x20 /* Enable any char to exit XOFF mode */

#define MOS7840_MSR_CTS        0x10 /* Current state of CTS */
#define MOS7840_MSR_DSR        0x20 /* Current state of DSR */
#define MOS7840_MSR_RI         0x40 /* Current state of RI */
#define MOS7840_MSR_CD         0x80 /* Current state of CD */

/*
 * Defines used for sending commands to port
 */

#define WAIT_FOR_EVER   (HZ * 0 )   /* timeout urb is wait for ever */
#define MOS_WDR_TIMEOUT (HZ * 5 )   /* default urb timeout */

#define MOS_PORT1       0x0200
#define MOS_PORT2       0x0300
#define MOS_VENREG      0x0000
#define MOS_MAX_PORT    0x02
#define MOS_WRITE       0x0E
#define MOS_READ        0x0D

/* Requests */
#define MCS_RD_RTYPE    0xC0
#define MCS_WR_RTYPE    0x40
#define MCS_RDREQ       0x0D
#define MCS_WRREQ       0x0E
#define MCS_CTRL_TIMEOUT        500
#define VENDOR_READ_LENGTH      (0x01)

#define MAX_NAME_LEN    64

#define ZLP_REG1  0x3A        //Zero_Flag_Reg1    58
#define ZLP_REG5  0x3E        //Zero_Flag_Reg5    62

/* For higher baud Rates use TIOCEXBAUD */
#define TIOCEXBAUD     0x5462

/* vendor id and device id defines */

#define USB_VENDOR_ID_MOSCHIP           0x9710
#define MOSCHIP_DEVICE_ID_7840          0x7840
#define MOSCHIP_DEVICE_ID_7820          0x7820

/* Interrupt Rotinue Defines    */

#define SERIAL_IIR_RLS      0x06
#define SERIAL_IIR_MS       0x00

/*
 *  Emulation of the bit mask on the LINE STATUS REGISTER.
 */
#define SERIAL_LSR_DR       0x0001
#define SERIAL_LSR_OE       0x0002
#define SERIAL_LSR_PE       0x0004
#define SERIAL_LSR_FE       0x0008
#define SERIAL_LSR_BI       0x0010

#define MOS_MSR_DELTA_CTS   0x10
#define MOS_MSR_DELTA_DSR   0x20
#define MOS_MSR_DELTA_RI    0x40
#define MOS_MSR_DELTA_CD    0x80

// Serial Port register Address
#define INTERRUPT_ENABLE_REGISTER  ((__u16)(0x01))
#define FIFO_CONTROL_REGISTER      ((__u16)(0x02))
#define LINE_CONTROL_REGISTER      ((__u16)(0x03))
#define MODEM_CONTROL_REGISTER     ((__u16)(0x04))
#define LINE_STATUS_REGISTER       ((__u16)(0x05))
#define MODEM_STATUS_REGISTER      ((__u16)(0x06))
#define SCRATCH_PAD_REGISTER       ((__u16)(0x07))
#define DIVISOR_LATCH_LSB          ((__u16)(0x00))
#define DIVISOR_LATCH_MSB          ((__u16)(0x01))

#define CLK_MULTI_REGISTER         ((__u16)(0x02))
#define CLK_START_VALUE_REGISTER   ((__u16)(0x03))

#define SERIAL_LCR_DLAB            ((__u16)(0x0080))

/*
 * URB POOL related defines
 */
#define NUM_URBS                        16      /* URB Count */
#define URB_TRANSFER_BUFFER_SIZE        32      /* URB Size  */


static struct usb_device_id moschip_port_id_table[] = {
      {USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7840)},
      {USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7820)},
      {}                /* terminating entry */
};

static __devinitdata struct usb_device_id moschip_id_table_combined[] = {
      {USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7840)},
      {USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7820)},
      {}                /* terminating entry */
};

MODULE_DEVICE_TABLE(usb, moschip_id_table_combined);

/* This structure holds all of the local port information */

struct moschip_port {
      int port_num;           /*Actual port number in the device(1,2,etc) */
      struct urb *write_urb;  /* write URB for this port */
      struct urb *read_urb;   /* read URB for this port */
      struct urb *int_urb;
      __u8 shadowLCR;         /* last LCR value received */
      __u8 shadowMCR;         /* last MCR value received */
      char open;
      char open_ports;
      char zombie;
      wait_queue_head_t wait_chase; /* for handling sleeping while waiting for chase to finish */
      wait_queue_head_t delta_msr_wait;   /* for handling sleeping while waiting for msr change to happen */
      int delta_msr_cond;
      struct async_icount icount;
      struct usb_serial_port *port; /* loop back to the owner of this object */

      /*Offsets */
      __u8 SpRegOffset;
      __u8 ControlRegOffset;
      __u8 DcrRegOffset;
      //for processing control URBS in interrupt context
      struct urb *control_urb;
      struct usb_ctrlrequest *dr;
      char *ctrl_buf;
      int MsrLsr;

      spinlock_t pool_lock;
      struct urb *write_urb_pool[NUM_URBS];
      char busy[NUM_URBS];
};


static int debug;

/*
 * mos7840_set_reg_sync
 *    To set the Control register by calling usb_fill_control_urb function
 *    by passing usb_sndctrlpipe function as parameter.
 */

static int mos7840_set_reg_sync(struct usb_serial_port *port, __u16 reg,
                        __u16 val)
{
      struct usb_device *dev = port->serial->dev;
      val = val & 0x00ff;
      dbg("mos7840_set_reg_sync offset is %x, value %x\n", reg, val);

      return usb_control_msg(dev, usb_sndctrlpipe(dev, 0), MCS_WRREQ,
                         MCS_WR_RTYPE, val, reg, NULL, 0,
                         MOS_WDR_TIMEOUT);
}

/*
 * mos7840_get_reg_sync
 *    To set the Uart register by calling usb_fill_control_urb function by
 *    passing usb_rcvctrlpipe function as parameter.
 */

static int mos7840_get_reg_sync(struct usb_serial_port *port, __u16 reg,
                        __u16 * val)
{
      struct usb_device *dev = port->serial->dev;
      int ret = 0;

      ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), MCS_RDREQ,
                        MCS_RD_RTYPE, 0, reg, val, VENDOR_READ_LENGTH,
                        MOS_WDR_TIMEOUT);
      dbg("mos7840_get_reg_sync offset is %x, return val %x\n", reg, *val);
      *val = (*val) & 0x00ff;
      return ret;
}

/*
 * mos7840_set_uart_reg
 *    To set the Uart register by calling usb_fill_control_urb function by
 *    passing usb_sndctrlpipe function as parameter.
 */

static int mos7840_set_uart_reg(struct usb_serial_port *port, __u16 reg,
                        __u16 val)
{

      struct usb_device *dev = port->serial->dev;
      val = val & 0x00ff;
      // For the UART control registers, the application number need to be Or'ed
      if (port->serial->num_ports == 4) {
            val |=
                (((__u16) port->number - (__u16) (port->serial->minor)) +
                 1) << 8;
            dbg("mos7840_set_uart_reg application number is %x\n", val);
      } else {
            if (((__u16) port->number - (__u16) (port->serial->minor)) == 0) {
                  val |=
                      (((__u16) port->number -
                        (__u16) (port->serial->minor)) + 1) << 8;
                  dbg("mos7840_set_uart_reg application number is %x\n",
                      val);
            } else {
                  val |=
                      (((__u16) port->number -
                        (__u16) (port->serial->minor)) + 2) << 8;
                  dbg("mos7840_set_uart_reg application number is %x\n",
                      val);
            }
      }
      return usb_control_msg(dev, usb_sndctrlpipe(dev, 0), MCS_WRREQ,
                         MCS_WR_RTYPE, val, reg, NULL, 0,
                         MOS_WDR_TIMEOUT);

}

/*
 * mos7840_get_uart_reg
 *    To set the Control register by calling usb_fill_control_urb function
 *    by passing usb_rcvctrlpipe function as parameter.
 */
static int mos7840_get_uart_reg(struct usb_serial_port *port, __u16 reg,
                        __u16 * val)
{
      struct usb_device *dev = port->serial->dev;
      int ret = 0;
      __u16 Wval;

      //dbg("application number is %4x \n",(((__u16)port->number - (__u16)(port->serial->minor))+1)<<8);
      /*Wval  is same as application number */
      if (port->serial->num_ports == 4) {
            Wval =
                (((__u16) port->number - (__u16) (port->serial->minor)) +
                 1) << 8;
            dbg("mos7840_get_uart_reg application number is %x\n", Wval);
      } else {
            if (((__u16) port->number - (__u16) (port->serial->minor)) == 0) {
                  Wval =
                      (((__u16) port->number -
                        (__u16) (port->serial->minor)) + 1) << 8;
                  dbg("mos7840_get_uart_reg application number is %x\n",
                      Wval);
            } else {
                  Wval =
                      (((__u16) port->number -
                        (__u16) (port->serial->minor)) + 2) << 8;
                  dbg("mos7840_get_uart_reg application number is %x\n",
                      Wval);
            }
      }
      ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), MCS_RDREQ,
                        MCS_RD_RTYPE, Wval, reg, val, VENDOR_READ_LENGTH,
                        MOS_WDR_TIMEOUT);
      *val = (*val) & 0x00ff;
      return ret;
}

static void mos7840_dump_serial_port(struct moschip_port *mos7840_port)
{

      dbg("***************************************\n");
      dbg("SpRegOffset is %2x\n", mos7840_port->SpRegOffset);
      dbg("ControlRegOffset is %2x \n", mos7840_port->ControlRegOffset);
      dbg("DCRRegOffset is %2x \n", mos7840_port->DcrRegOffset);
      dbg("***************************************\n");

}

/************************************************************************/
/************************************************************************/
/*             I N T E R F A C E   F U N C T I O N S              */
/*             I N T E R F A C E   F U N C T I O N S              */
/************************************************************************/
/************************************************************************/

static inline void mos7840_set_port_private(struct usb_serial_port *port,
                                  struct moschip_port *data)
{
      usb_set_serial_port_data(port, (void *)data);
}

static inline struct moschip_port *mos7840_get_port_private(struct
                                              usb_serial_port
                                              *port)
{
      return (struct moschip_port *)usb_get_serial_port_data(port);
}

static void mos7840_handle_new_msr(struct moschip_port *port, __u8 new_msr)
{
      struct moschip_port *mos7840_port;
      struct async_icount *icount;
      mos7840_port = port;
      icount = &mos7840_port->icount;
      if (new_msr &
          (MOS_MSR_DELTA_CTS | MOS_MSR_DELTA_DSR | MOS_MSR_DELTA_RI |
           MOS_MSR_DELTA_CD)) {
            icount = &mos7840_port->icount;

            /* update input line counters */
            if (new_msr & MOS_MSR_DELTA_CTS) {
                  icount->cts++;
                  smp_wmb();
            }
            if (new_msr & MOS_MSR_DELTA_DSR) {
                  icount->dsr++;
                  smp_wmb();
            }
            if (new_msr & MOS_MSR_DELTA_CD) {
                  icount->dcd++;
                  smp_wmb();
            }
            if (new_msr & MOS_MSR_DELTA_RI) {
                  icount->rng++;
                  smp_wmb();
            }
      }
}

static void mos7840_handle_new_lsr(struct moschip_port *port, __u8 new_lsr)
{
      struct async_icount *icount;

      dbg("%s - %02x", __FUNCTION__, new_lsr);

      if (new_lsr & SERIAL_LSR_BI) {
            //
            // Parity and Framing errors only count if they
            // occur exclusive of a break being
            // received.
            //
            new_lsr &= (__u8) (SERIAL_LSR_OE | SERIAL_LSR_BI);
      }

      /* update input line counters */
      icount = &port->icount;
      if (new_lsr & SERIAL_LSR_BI) {
            icount->brk++;
            smp_wmb();
      }
      if (new_lsr & SERIAL_LSR_OE) {
            icount->overrun++;
            smp_wmb();
      }
      if (new_lsr & SERIAL_LSR_PE) {
            icount->parity++;
            smp_wmb();
      }
      if (new_lsr & SERIAL_LSR_FE) {
            icount->frame++;
            smp_wmb();
      }
}

/************************************************************************/
/************************************************************************/
/*            U S B  C A L L B A C K   F U N C T I O N S                */
/*            U S B  C A L L B A C K   F U N C T I O N S                */
/************************************************************************/
/************************************************************************/

static void mos7840_control_callback(struct urb *urb)
{
      unsigned char *data;
      struct moschip_port *mos7840_port;
      __u8 regval = 0x0;
      int result = 0;
      int status = urb->status;

      mos7840_port = (struct moschip_port *)urb->context;

      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);
            return;
      default:
            dbg("%s - nonzero urb status received: %d", __FUNCTION__,
                status);
            goto exit;
      }

      dbg("%s urb buffer size is %d\n", __FUNCTION__, urb->actual_length);
      dbg("%s mos7840_port->MsrLsr is %d port %d\n", __FUNCTION__,
          mos7840_port->MsrLsr, mos7840_port->port_num);
      data = urb->transfer_buffer;
      regval = (__u8) data[0];
      dbg("%s data is %x\n", __FUNCTION__, regval);
      if (mos7840_port->MsrLsr == 0)
            mos7840_handle_new_msr(mos7840_port, regval);
      else if (mos7840_port->MsrLsr == 1)
            mos7840_handle_new_lsr(mos7840_port, regval);

exit:
      spin_lock(&mos7840_port->pool_lock);
      if (!mos7840_port->zombie)
            result = usb_submit_urb(mos7840_port->int_urb, GFP_ATOMIC);
      spin_unlock(&mos7840_port->pool_lock);
      if (result) {
            dev_err(&urb->dev->dev,
                  "%s - Error %d submitting interrupt urb\n",
                  __FUNCTION__, result);
      }
}

static int mos7840_get_reg(struct moschip_port *mcs, __u16 Wval, __u16 reg,
                     __u16 * val)
{
      struct usb_device *dev = mcs->port->serial->dev;
      struct usb_ctrlrequest *dr = mcs->dr;
      unsigned char *buffer = mcs->ctrl_buf;
      int ret;

      dr->bRequestType = MCS_RD_RTYPE;
      dr->bRequest = MCS_RDREQ;
      dr->wValue = cpu_to_le16(Wval);     //0;
      dr->wIndex = cpu_to_le16(reg);
      dr->wLength = cpu_to_le16(2);

      usb_fill_control_urb(mcs->control_urb, dev, usb_rcvctrlpipe(dev, 0),
                       (unsigned char *)dr, buffer, 2,
                       mos7840_control_callback, mcs);
      mcs->control_urb->transfer_buffer_length = 2;
      ret = usb_submit_urb(mcs->control_urb, GFP_ATOMIC);
      return ret;
}

/*****************************************************************************
 * mos7840_interrupt_callback
 *    this is the callback function for when we have received data on the
 *    interrupt endpoint.
 *****************************************************************************/

static void mos7840_interrupt_callback(struct urb *urb)
{
      int result;
      int length;
      struct moschip_port *mos7840_port;
      struct usb_serial *serial;
      __u16 Data;
      unsigned char *data;
      __u8 sp[5], st;
      int i, rv = 0;
      __u16 wval, wreg = 0;
      int status = urb->status;

      dbg("%s", " : Entering\n");

      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);
            return;
      default:
            dbg("%s - nonzero urb status received: %d", __FUNCTION__,
                status);
            goto exit;
      }

      length = urb->actual_length;
      data = urb->transfer_buffer;

      serial = (struct usb_serial *)urb->context;

      /* Moschip get 5 bytes
       * Byte 1 IIR Port 1 (port.number is 0)
       * Byte 2 IIR Port 2 (port.number is 1)
       * Byte 3 IIR Port 3 (port.number is 2)
       * Byte 4 IIR Port 4 (port.number is 3)
       * Byte 5 FIFO status for both */

      if (length && length > 5) {
            dbg("%s \n", "Wrong data !!!");
            return;
      }

      sp[0] = (__u8) data[0];
      sp[1] = (__u8) data[1];
      sp[2] = (__u8) data[2];
      sp[3] = (__u8) data[3];
      st = (__u8) data[4];

      for (i = 0; i < serial->num_ports; i++) {
            mos7840_port = mos7840_get_port_private(serial->port[i]);
            wval =
                (((__u16) serial->port[i]->number -
                  (__u16) (serial->minor)) + 1) << 8;
            if (mos7840_port->open) {
                  if (sp[i] & 0x01) {
                        dbg("SP%d No Interrupt !!!\n", i);
                  } else {
                        switch (sp[i] & 0x0f) {
                        case SERIAL_IIR_RLS:
                              dbg("Serial Port %d: Receiver status error or ", i);
                              dbg("address bit detected in 9-bit mode\n");
                              mos7840_port->MsrLsr = 1;
                              wreg = LINE_STATUS_REGISTER;
                              break;
                        case SERIAL_IIR_MS:
                              dbg("Serial Port %d: Modem status change\n", i);
                              mos7840_port->MsrLsr = 0;
                              wreg = MODEM_STATUS_REGISTER;
                              break;
                        }
                        spin_lock(&mos7840_port->pool_lock);
                        if (!mos7840_port->zombie) {
                              rv = mos7840_get_reg(mos7840_port, wval, wreg, &Data);
                        } else {
                              spin_unlock(&mos7840_port->pool_lock);
                              return;
                        }
                        spin_unlock(&mos7840_port->pool_lock);
                  }
            }
      }
      if (!(rv < 0)) /* the completion handler for the control urb will resubmit */
            return;
exit:
      result = usb_submit_urb(urb, GFP_ATOMIC);
      if (result) {
            dev_err(&urb->dev->dev,
                  "%s - Error %d submitting interrupt urb\n",
                  __FUNCTION__, result);
      }
}

static int mos7840_port_paranoia_check(struct usb_serial_port *port,
                               const char *function)
{
      if (!port) {
            dbg("%s - port == NULL", function);
            return -1;
      }
      if (!port->serial) {
            dbg("%s - port->serial == NULL", function);
            return -1;
      }

      return 0;
}

/* Inline functions to check the sanity of a pointer that is passed to us */
static int mos7840_serial_paranoia_check(struct usb_serial *serial,
                               const char *function)
{
      if (!serial) {
            dbg("%s - serial == NULL", function);
            return -1;
      }
      if (!serial->type) {
            dbg("%s - serial->type == NULL!", function);
            return -1;
      }

      return 0;
}

static struct usb_serial *mos7840_get_usb_serial(struct usb_serial_port *port,
                                     const char *function)
{
      /* if no port was specified, or it fails a paranoia check */
      if (!port ||
          mos7840_port_paranoia_check(port, function) ||
          mos7840_serial_paranoia_check(port->serial, function)) {
            /* then say that we don't have a valid usb_serial thing, which will
             * end up genrating -ENODEV return values */
            return NULL;
      }

      return port->serial;
}

/*****************************************************************************
 * mos7840_bulk_in_callback
 *    this is the callback function for when we have received data on the
 *    bulk in endpoint.
 *****************************************************************************/

static void mos7840_bulk_in_callback(struct urb *urb)
{
      int retval;
      unsigned char *data;
      struct usb_serial *serial;
      struct usb_serial_port *port;
      struct moschip_port *mos7840_port;
      struct tty_struct *tty;
      int status = urb->status;

      if (status) {
            dbg("nonzero read bulk status received: %d", status);
            return;
      }

      mos7840_port = (struct moschip_port *)urb->context;
      if (!mos7840_port) {
            dbg("%s", "NULL mos7840_port pointer \n");
            return;
      }

      port = (struct usb_serial_port *)mos7840_port->port;
      if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
            dbg("%s", "Port Paranoia failed \n");
            return;
      }

      serial = mos7840_get_usb_serial(port, __FUNCTION__);
      if (!serial) {
            dbg("%s\n", "Bad serial pointer ");
            return;
      }

      dbg("%s\n", "Entering... \n");

      data = urb->transfer_buffer;

      dbg("%s", "Entering ........... \n");

      if (urb->actual_length) {
            tty = mos7840_port->port->tty;
            if (tty) {
                  tty_buffer_request_room(tty, urb->actual_length);
                  tty_insert_flip_string(tty, data, urb->actual_length);
                  dbg(" %s \n", data);
                  tty_flip_buffer_push(tty);
            }
            mos7840_port->icount.rx += urb->actual_length;
            smp_wmb();
            dbg("mos7840_port->icount.rx is %d:\n",
                mos7840_port->icount.rx);
      }

      if (!mos7840_port->read_urb) {
            dbg("%s", "URB KILLED !!!\n");
            return;
      }


      mos7840_port->read_urb->dev = serial->dev;

      retval = usb_submit_urb(mos7840_port->read_urb, GFP_ATOMIC);

      if (retval) {
            dbg(" usb_submit_urb(read bulk) failed, retval = %d",
             retval);
      }
}

/*****************************************************************************
 * mos7840_bulk_out_data_callback
 *    this is the callback function for when we have finished sending serial data
 *    on the bulk out endpoint.
 *****************************************************************************/

static void mos7840_bulk_out_data_callback(struct urb *urb)
{
      struct moschip_port *mos7840_port;
      struct tty_struct *tty;
      int status = urb->status;
      int i;

      mos7840_port = (struct moschip_port *)urb->context;
      spin_lock(&mos7840_port->pool_lock);
      for (i = 0; i < NUM_URBS; i++) {
            if (urb == mos7840_port->write_urb_pool[i]) {
                  mos7840_port->busy[i] = 0;
                  break;
            }
      }
      spin_unlock(&mos7840_port->pool_lock);

      if (status) {
            dbg("nonzero write bulk status received:%d\n", status);
            return;
      }

      if (mos7840_port_paranoia_check(mos7840_port->port, __FUNCTION__)) {
            dbg("%s", "Port Paranoia failed \n");
            return;
      }

      dbg("%s \n", "Entering .........");

      tty = mos7840_port->port->tty;

      if (tty && mos7840_port->open)
            tty_wakeup(tty);

}

/************************************************************************/
/*       D R I V E R  T T Y  I N T E R F A C E  F U N C T I O N S       */
/************************************************************************/
#ifdef MCSSerialProbe
static int mos7840_serial_probe(struct usb_serial *serial,
                        const struct usb_device_id *id)
{

      /*need to implement the mode_reg reading and updating\
         structures usb_serial_ device_type\
         (i.e num_ports, num_bulkin,bulkout etc) */
      /* Also we can update the changes  attach */
      return 1;
}
#endif

/*****************************************************************************
 * mos7840_open
 *    this function is called by the tty driver when a port is opened
 *    If successful, we return 0
 *    Otherwise we return a negative error number.
 *****************************************************************************/

static int mos7840_open(struct usb_serial_port *port, struct file *filp)
{
      int response;
      int j;
      struct usb_serial *serial;
      struct urb *urb;
      __u16 Data;
      int status;
      struct moschip_port *mos7840_port;
      struct moschip_port *port0;

      if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
            dbg("%s", "Port Paranoia failed \n");
            return -ENODEV;
      }

      serial = port->serial;

      if (mos7840_serial_paranoia_check(serial, __FUNCTION__)) {
            dbg("%s", "Serial Paranoia failed \n");
            return -ENODEV;
      }

      mos7840_port = mos7840_get_port_private(port);
      port0 = mos7840_get_port_private(serial->port[0]);

      if (mos7840_port == NULL || port0 == NULL)
            return -ENODEV;

      usb_clear_halt(serial->dev, port->write_urb->pipe);
      usb_clear_halt(serial->dev, port->read_urb->pipe);
      port0->open_ports++;

      /* Initialising the write urb pool */
      for (j = 0; j < NUM_URBS; ++j) {
            urb = usb_alloc_urb(0, GFP_KERNEL);
            mos7840_port->write_urb_pool[j] = urb;

            if (urb == NULL) {
                  err("No more urbs???");
                  continue;
            }

            urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE, GFP_KERNEL);
            if (!urb->transfer_buffer) {
                  usb_free_urb(urb);
                  mos7840_port->write_urb_pool[j] = NULL;
                  err("%s-out of memory for urb buffers.", __FUNCTION__);
                  continue;
            }
      }

/*****************************************************************************
 * Initialize MCS7840 -- Write Init values to corresponding Registers
 *
 * Register Index
 * 1 : IER
 * 2 : FCR
 * 3 : LCR
 * 4 : MCR
 *
 * 0x08 : SP1/2 Control Reg
 *****************************************************************************/

//NEED to check the following Block

      status = 0;
      Data = 0x0;
      status = mos7840_get_reg_sync(port, mos7840_port->SpRegOffset, &Data);
      if (status < 0) {
            dbg("Reading Spreg failed\n");
            return -1;
      }
      Data |= 0x80;
      status = mos7840_set_reg_sync(port, mos7840_port->SpRegOffset, Data);
      if (status < 0) {
            dbg("writing Spreg failed\n");
            return -1;
      }

      Data &= ~0x80;
      status = mos7840_set_reg_sync(port, mos7840_port->SpRegOffset, Data);
      if (status < 0) {
            dbg("writing Spreg failed\n");
            return -1;
      }
//End of block to be checked

      status = 0;
      Data = 0x0;
      status =
          mos7840_get_reg_sync(port, mos7840_port->ControlRegOffset, &Data);
      if (status < 0) {
            dbg("Reading Controlreg failed\n");
            return -1;
      }
      Data |= 0x08;           //Driver done bit
      Data |= 0x20;           //rx_disable
      status = mos7840_set_reg_sync(port, mos7840_port->ControlRegOffset, Data);
      if (status < 0) {
            dbg("writing Controlreg failed\n");
            return -1;
      }
      //do register settings here
      // Set all regs to the device default values.
      ////////////////////////////////////
      // First Disable all interrupts.
      ////////////////////////////////////

      Data = 0x00;
      status = mos7840_set_uart_reg(port, INTERRUPT_ENABLE_REGISTER, Data);
      if (status < 0) {
            dbg("disableing interrupts failed\n");
            return -1;
      }
      // Set FIFO_CONTROL_REGISTER to the default value
      Data = 0x00;
      status = mos7840_set_uart_reg(port, FIFO_CONTROL_REGISTER, Data);
      if (status < 0) {
            dbg("Writing FIFO_CONTROL_REGISTER  failed\n");
            return -1;
      }

      Data = 0xcf;
      status = mos7840_set_uart_reg(port, FIFO_CONTROL_REGISTER, Data);
      if (status < 0) {
            dbg("Writing FIFO_CONTROL_REGISTER  failed\n");
            return -1;
      }

      Data = 0x03;
      status = mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
      mos7840_port->shadowLCR = Data;

      Data = 0x0b;
      status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
      mos7840_port->shadowMCR = Data;

      Data = 0x00;
      status = mos7840_get_uart_reg(port, LINE_CONTROL_REGISTER, &Data);
      mos7840_port->shadowLCR = Data;

      Data |= SERIAL_LCR_DLAB;      //data latch enable in LCR 0x80
      status = mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);

      Data = 0x0c;
      status = 0;
      status = mos7840_set_uart_reg(port, DIVISOR_LATCH_LSB, Data);

      Data = 0x0;
      status = 0;
      status = mos7840_set_uart_reg(port, DIVISOR_LATCH_MSB, Data);

      Data = 0x00;
      status = 0;
      status = mos7840_get_uart_reg(port, LINE_CONTROL_REGISTER, &Data);

      Data = Data & ~SERIAL_LCR_DLAB;
      status = 0;
      status = mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
      mos7840_port->shadowLCR = Data;

      //clearing Bulkin and Bulkout Fifo
      Data = 0x0;
      status = 0;
      status = mos7840_get_reg_sync(port, mos7840_port->SpRegOffset, &Data);

      Data = Data | 0x0c;
      status = 0;
      status = mos7840_set_reg_sync(port, mos7840_port->SpRegOffset, Data);

      Data = Data & ~0x0c;
      status = 0;
      status = mos7840_set_reg_sync(port, mos7840_port->SpRegOffset, Data);
      //Finally enable all interrupts
      Data = 0x0;
      Data = 0x0c;
      status = 0;
      status = mos7840_set_uart_reg(port, INTERRUPT_ENABLE_REGISTER, Data);

      //clearing rx_disable
      Data = 0x0;
      status = 0;
      status =
          mos7840_get_reg_sync(port, mos7840_port->ControlRegOffset, &Data);
      Data = Data & ~0x20;
      status = 0;
      status =
          mos7840_set_reg_sync(port, mos7840_port->ControlRegOffset, Data);

      // rx_negate
      Data = 0x0;
      status = 0;
      status =
          mos7840_get_reg_sync(port, mos7840_port->ControlRegOffset, &Data);
      Data = Data | 0x10;
      status = 0;
      status =
          mos7840_set_reg_sync(port, mos7840_port->ControlRegOffset, Data);

      /* force low_latency on so that our tty_push actually forces *
       * the data through,otherwise it is scheduled, and with      *
       * high data rates (like with OHCI) data can get lost.       */

      if (port->tty)
            port->tty->low_latency = 1;
/* Check to see if we've set up our endpoint info yet    *
     * (can't set it up in mos7840_startup as the structures *
     * were not set up at that time.)                        */
      if (port0->open_ports == 1) {
            if (serial->port[0]->interrupt_in_buffer == NULL) {

                  /* set up interrupt urb */

                  usb_fill_int_urb(serial->port[0]->interrupt_in_urb,
                               serial->dev,
                               usb_rcvintpipe(serial->dev,
                                          serial->port[0]->
                                          interrupt_in_endpointAddress),
                               serial->port[0]->interrupt_in_buffer,
                               serial->port[0]->interrupt_in_urb->
                               transfer_buffer_length,
                               mos7840_interrupt_callback,
                               serial,
                               serial->port[0]->interrupt_in_urb->
                               interval);

                  /* start interrupt read for mos7840               *
                   * will continue as long as mos7840 is connected  */

                  response =
                      usb_submit_urb(serial->port[0]->interrupt_in_urb,
                                 GFP_KERNEL);
                  if (response) {
                        err("%s - Error %d submitting interrupt urb",
                            __FUNCTION__, response);
                  }

            }

      }

      /* see if we've set up our endpoint info yet   *
       * (can't set it up in mos7840_startup as the  *
       * structures were not set up at that time.)   */

      dbg("port number is %d \n", port->number);
      dbg("serial number is %d \n", port->serial->minor);
      dbg("Bulkin endpoint is %d \n", port->bulk_in_endpointAddress);
      dbg("BulkOut endpoint is %d \n", port->bulk_out_endpointAddress);
      dbg("Interrupt endpoint is %d \n", port->interrupt_in_endpointAddress);
      dbg("port's number in the device is %d\n", mos7840_port->port_num);
      mos7840_port->read_urb = port->read_urb;

      /* set up our bulk in urb */

      usb_fill_bulk_urb(mos7840_port->read_urb,
                    serial->dev,
                    usb_rcvbulkpipe(serial->dev,
                                port->bulk_in_endpointAddress),
                    port->bulk_in_buffer,
                    mos7840_port->read_urb->transfer_buffer_length,
                    mos7840_bulk_in_callback, mos7840_port);

      dbg("mos7840_open: bulkin endpoint is %d\n",
          port->bulk_in_endpointAddress);
      response = usb_submit_urb(mos7840_port->read_urb, GFP_KERNEL);
      if (response) {
            err("%s - Error %d submitting control urb", __FUNCTION__,
                response);
      }

      /* initialize our wait queues */
      init_waitqueue_head(&mos7840_port->wait_chase);
      init_waitqueue_head(&mos7840_port->delta_msr_wait);

      /* initialize our icount structure */
      memset(&(mos7840_port->icount), 0x00, sizeof(mos7840_port->icount));

      /* initialize our port settings */
      mos7840_port->shadowMCR = MCR_MASTER_IE;  /* Must set to enable ints! */
      /* send a open port command */
      mos7840_port->open = 1;
      //mos7840_change_port_settings(mos7840_port,old_termios);
      mos7840_port->icount.tx = 0;
      mos7840_port->icount.rx = 0;

      dbg("\n\nusb_serial serial:%p       mos7840_port:%p\n      usb_serial_port port:%p\n\n", serial, mos7840_port, port);

      return 0;

}

/*****************************************************************************
 * mos7840_chars_in_buffer
 *    this function is called by the tty driver when it wants to know how many
 *    bytes of data we currently have outstanding in the port (data that has
 *    been written, but hasn't made it out the port yet)
 *    If successful, we return the number of bytes left to be written in the
 *    system,
 *    Otherwise we return a negative error number.
 *****************************************************************************/

static int mos7840_chars_in_buffer(struct usb_serial_port *port)
{
      int i;
      int chars = 0;
      unsigned long flags;
      struct moschip_port *mos7840_port;

      dbg("%s \n", " mos7840_chars_in_buffer:entering ...........");

      if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
            dbg("%s", "Invalid port \n");
            return -1;
      }

      mos7840_port = mos7840_get_port_private(port);
      if (mos7840_port == NULL) {
            dbg("%s \n", "mos7840_break:leaving ...........");
            return -1;
      }

      spin_lock_irqsave(&mos7840_port->pool_lock,flags);
      for (i = 0; i < NUM_URBS; ++i) {
            if (mos7840_port->busy[i]) {
                  chars += URB_TRANSFER_BUFFER_SIZE;
            }
      }
      spin_unlock_irqrestore(&mos7840_port->pool_lock,flags);
      dbg("%s - returns %d", __FUNCTION__, chars);
      return chars;

}

/************************************************************************
 *
 * mos7840_block_until_tx_empty
 *
 *    This function will block the close until one of the following:
 *          1. TX count are 0
 *          2. The mos7840 has stopped
 *          3. A timout of 3 seconds without activity has expired
 *
 ************************************************************************/
static void mos7840_block_until_tx_empty(struct moschip_port *mos7840_port)
{
      int timeout = HZ / 10;
      int wait = 30;
      int count;

      while (1) {

            count = mos7840_chars_in_buffer(mos7840_port->port);

            /* Check for Buffer status */
            if (count <= 0) {
                  return;
            }

            /* Block the thread for a while */
            interruptible_sleep_on_timeout(&mos7840_port->wait_chase,
                                     timeout);

            /* No activity.. count down section */
            wait--;
            if (wait == 0) {
                  dbg("%s - TIMEOUT", __FUNCTION__);
                  return;
            } else {
                  /* Reset timout value back to seconds */
                  wait = 30;
            }
      }
}

/*****************************************************************************
 * mos7840_close
 *    this function is called by the tty driver when a port is closed
 *****************************************************************************/

static void mos7840_close(struct usb_serial_port *port, struct file *filp)
{
      struct usb_serial *serial;
      struct moschip_port *mos7840_port;
      struct moschip_port *port0;
      int j;
      __u16 Data;

      dbg("%s\n", "mos7840_close:entering...");

      if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
            dbg("%s", "Port Paranoia failed \n");
            return;
      }

      serial = mos7840_get_usb_serial(port, __FUNCTION__);
      if (!serial) {
            dbg("%s", "Serial Paranoia failed \n");
            return;
      }

      mos7840_port = mos7840_get_port_private(port);
      port0 = mos7840_get_port_private(serial->port[0]);

      if (mos7840_port == NULL || port0 == NULL)
            return;

      for (j = 0; j < NUM_URBS; ++j)
            usb_kill_urb(mos7840_port->write_urb_pool[j]);

      /* Freeing Write URBs */
      for (j = 0; j < NUM_URBS; ++j) {
            if (mos7840_port->write_urb_pool[j]) {
                  if (mos7840_port->write_urb_pool[j]->transfer_buffer)
                        kfree(mos7840_port->write_urb_pool[j]->
                              transfer_buffer);

                  usb_free_urb(mos7840_port->write_urb_pool[j]);
            }
      }

      if (serial->dev) {
            /* flush and block until tx is empty */
            mos7840_block_until_tx_empty(mos7840_port);
      }

      /* While closing port, shutdown all bulk read, write  *
       * and interrupt read if they exists                  */
      if (serial->dev) {

            if (mos7840_port->write_urb) {
                  dbg("%s", "Shutdown bulk write\n");
                  usb_kill_urb(mos7840_port->write_urb);
            }

            if (mos7840_port->read_urb) {
                  dbg("%s", "Shutdown bulk read\n");
                  usb_kill_urb(mos7840_port->read_urb);
            }
            if ((&mos7840_port->control_urb)) {
                  dbg("%s", "Shutdown control read\n");
                  //      usb_kill_urb (mos7840_port->control_urb);

            }
      }
//              if(mos7840_port->ctrl_buf != NULL)
//                      kfree(mos7840_port->ctrl_buf);
      port0->open_ports--;
      dbg("mos7840_num_open_ports in close%d:in port%d\n",
          port0->open_ports, port->number);
      if (port0->open_ports == 0) {
            if (serial->port[0]->interrupt_in_urb) {
                  dbg("%s", "Shutdown interrupt_in_urb\n");
                  usb_kill_urb(serial->port[0]->interrupt_in_urb);
            }
      }

      if (mos7840_port->write_urb) {
            /* if this urb had a transfer buffer already (old tx) free it */

            if (mos7840_port->write_urb->transfer_buffer != NULL) {
                  kfree(mos7840_port->write_urb->transfer_buffer);
            }
            usb_free_urb(mos7840_port->write_urb);
      }

      Data = 0x0;
      mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);

      Data = 0x00;
      mos7840_set_uart_reg(port, INTERRUPT_ENABLE_REGISTER, Data);

      mos7840_port->open = 0;

      dbg("%s \n", "Leaving ............");
}

/************************************************************************
 *
 * mos7840_block_until_chase_response
 *
 *    This function will block the close until one of the following:
 *          1. Response to our Chase comes from mos7840
 *          2. A timout of 10 seconds without activity has expired
 *             (1K of mos7840 data @ 2400 baud ==> 4 sec to empty)
 *
 ************************************************************************/

static void mos7840_block_until_chase_response(struct moschip_port
                                     *mos7840_port)
{
      int timeout = 1 * HZ;
      int wait = 10;
      int count;

      while (1) {
            count = mos7840_chars_in_buffer(mos7840_port->port);

            /* Check for Buffer status */
            if (count <= 0) {
                  return;
            }

            /* Block the thread for a while */
            interruptible_sleep_on_timeout(&mos7840_port->wait_chase,
                                     timeout);
            /* No activity.. count down section */
            wait--;
            if (wait == 0) {
                  dbg("%s - TIMEOUT", __FUNCTION__);
                  return;
            } else {
                  /* Reset timout value back to seconds */
                  wait = 10;
            }
      }

}

/*****************************************************************************
 * mos7840_break
 *    this function sends a break to the port
 *****************************************************************************/
static void mos7840_break(struct usb_serial_port *port, int break_state)
{
      unsigned char data;
      struct usb_serial *serial;
      struct moschip_port *mos7840_port;

      dbg("%s \n", "Entering ...........");
      dbg("mos7840_break: Start\n");

      if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
            dbg("%s", "Port Paranoia failed \n");
            return;
      }

      serial = mos7840_get_usb_serial(port, __FUNCTION__);
      if (!serial) {
            dbg("%s", "Serial Paranoia failed \n");
            return;
      }

      mos7840_port = mos7840_get_port_private(port);

      if (mos7840_port == NULL) {
            return;
      }

      if (serial->dev) {

            /* flush and block until tx is empty */
            mos7840_block_until_chase_response(mos7840_port);
      }

      if (break_state == -1) {
            data = mos7840_port->shadowLCR | LCR_SET_BREAK;
      } else {
            data = mos7840_port->shadowLCR & ~LCR_SET_BREAK;
      }

      mos7840_port->shadowLCR = data;
      dbg("mcs7840_break mos7840_port->shadowLCR is %x\n",
          mos7840_port->shadowLCR);
      mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER,
                       mos7840_port->shadowLCR);

      return;
}

/*****************************************************************************
 * mos7840_write_room
 *    this function is called by the tty driver when it wants to know how many
 *    bytes of data we can accept for a specific port.
 *    If successful, we return the amount of room that we have for this port
 *    Otherwise we return a negative error number.
 *****************************************************************************/

static int mos7840_write_room(struct usb_serial_port *port)
{
      int i;
      int room = 0;
      unsigned long flags;
      struct moschip_port *mos7840_port;

      dbg("%s \n", " mos7840_write_room:entering ...........");

      if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
            dbg("%s", "Invalid port \n");
            dbg("%s \n", " mos7840_write_room:leaving ...........");
            return -1;
      }

      mos7840_port = mos7840_get_port_private(port);
      if (mos7840_port == NULL) {
            dbg("%s \n", "mos7840_break:leaving ...........");
            return -1;
      }

      spin_lock_irqsave(&mos7840_port->pool_lock, flags);
      for (i = 0; i < NUM_URBS; ++i) {
            if (!mos7840_port->busy[i]) {
                  room += URB_TRANSFER_BUFFER_SIZE;
            }
      }
      spin_unlock_irqrestore(&mos7840_port->pool_lock, flags);

      room = (room == 0) ? 0 : room - URB_TRANSFER_BUFFER_SIZE + 1;
      dbg("%s - returns %d", __FUNCTION__, room);
      return room;

}

/*****************************************************************************
 * mos7840_write
 *    this function is called by the tty driver when data should be written to
 *    the port.
 *    If successful, we return the number of bytes written, otherwise we
 *      return a negative error number.
 *****************************************************************************/

static int mos7840_write(struct usb_serial_port *port,
                   const unsigned char *data, int count)
{
      int status;
      int i;
      int bytes_sent = 0;
      int transfer_size;
      unsigned long flags;

      struct moschip_port *mos7840_port;
      struct usb_serial *serial;
      struct urb *urb;
      //__u16 Data;
      const unsigned char *current_position = data;
      unsigned char *data1;
      dbg("%s \n", "entering ...........");
      //dbg("mos7840_write: mos7840_port->shadowLCR is %x\n",mos7840_port->shadowLCR);

#ifdef NOTMOS7840
      Data = 0x00;
      status = 0;
      status = mos7840_get_uart_reg(port, LINE_CONTROL_REGISTER, &Data);
      mos7840_port->shadowLCR = Data;
      dbg("mos7840_write: LINE_CONTROL_REGISTER is %x\n", Data);
      dbg("mos7840_write: mos7840_port->shadowLCR is %x\n",
          mos7840_port->shadowLCR);

      //Data = 0x03;
      //status = mos7840_set_uart_reg(port,LINE_CONTROL_REGISTER,Data);
      //mos7840_port->shadowLCR=Data;//Need to add later

      Data |= SERIAL_LCR_DLAB;      //data latch enable in LCR 0x80
      status = 0;
      status = mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);

      //Data = 0x0c;
      //status = mos7840_set_uart_reg(port,DIVISOR_LATCH_LSB,Data);
      Data = 0x00;
      status = 0;
      status = mos7840_get_uart_reg(port, DIVISOR_LATCH_LSB, &Data);
      dbg("mos7840_write:DLL value is %x\n", Data);

      Data = 0x0;
      status = 0;
      status = mos7840_get_uart_reg(port, DIVISOR_LATCH_MSB, &Data);
      dbg("mos7840_write:DLM value is %x\n", Data);

      Data = Data & ~SERIAL_LCR_DLAB;
      dbg("mos7840_write: mos7840_port->shadowLCR is %x\n",
          mos7840_port->shadowLCR);
      status = 0;
      status = mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
#endif

      if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
            dbg("%s", "Port Paranoia failed \n");
            return -1;
      }

      serial = port->serial;
      if (mos7840_serial_paranoia_check(serial, __FUNCTION__)) {
            dbg("%s", "Serial Paranoia failed \n");
            return -1;
      }

      mos7840_port = mos7840_get_port_private(port);
      if (mos7840_port == NULL) {
            dbg("%s", "mos7840_port is NULL\n");
            return -1;
      }

      /* try to find a free urb in the list */
      urb = NULL;

      spin_lock_irqsave(&mos7840_port->pool_lock, flags);
      for (i = 0; i < NUM_URBS; ++i) {
            if (!mos7840_port->busy[i]) {
                  mos7840_port->busy[i] = 1;
                  urb = mos7840_port->write_urb_pool[i];
                  dbg("\nURB:%d", i);
                  break;
            }
      }
      spin_unlock_irqrestore(&mos7840_port->pool_lock, flags);

      if (urb == NULL) {
            dbg("%s - no more free urbs", __FUNCTION__);
            goto exit;
      }

      if (urb->transfer_buffer == NULL) {
            urb->transfer_buffer =
                kmalloc(URB_TRANSFER_BUFFER_SIZE, GFP_KERNEL);

            if (urb->transfer_buffer == NULL) {
                  err("%s no more kernel memory...", __FUNCTION__);
                  goto exit;
            }
      }
      transfer_size = min(count, URB_TRANSFER_BUFFER_SIZE);

      memcpy(urb->transfer_buffer, current_position, transfer_size);

      /* fill urb with data and submit  */
      usb_fill_bulk_urb(urb,
                    serial->dev,
                    usb_sndbulkpipe(serial->dev,
                                port->bulk_out_endpointAddress),
                    urb->transfer_buffer,
                    transfer_size,
                    mos7840_bulk_out_data_callback, mos7840_port);

      data1 = urb->transfer_buffer;
      dbg("\nbulkout endpoint is %d", port->bulk_out_endpointAddress);

      /* send it down the pipe */
      status = usb_submit_urb(urb, GFP_ATOMIC);

      if (status) {
            mos7840_port->busy[i] = 0;
            err("%s - usb_submit_urb(write bulk) failed with status = %d",
                __FUNCTION__, status);
            bytes_sent = status;
            goto exit;
      }
      bytes_sent = transfer_size;
      mos7840_port->icount.tx += transfer_size;
      smp_wmb();
      dbg("mos7840_port->icount.tx is %d:\n", mos7840_port->icount.tx);
      exit:

      return bytes_sent;

}

/*****************************************************************************
 * mos7840_throttle
 *    this function is called by the tty driver when it wants to stop the data
 *    being read from the port.
 *****************************************************************************/

static void mos7840_throttle(struct usb_serial_port *port)
{
      struct moschip_port *mos7840_port;
      struct tty_struct *tty;
      int status;

      if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
            dbg("%s", "Invalid port \n");
            return;
      }

      dbg("- port %d\n", port->number);

      mos7840_port = mos7840_get_port_private(port);

      if (mos7840_port == NULL)
            return;

      if (!mos7840_port->open) {
            dbg("%s\n", "port not opened");
            return;
      }

      dbg("%s", "Entering .......... \n");

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

      /* if we are implementing XON/XOFF, send the stop character */
      if (I_IXOFF(tty)) {
            unsigned char stop_char = STOP_CHAR(tty);
            status = mos7840_write(port, &stop_char, 1);
            if (status <= 0) {
                  return;
            }
      }

      /* if we are implementing RTS/CTS, toggle that line */
      if (tty->termios->c_cflag & CRTSCTS) {
            mos7840_port->shadowMCR &= ~MCR_RTS;
            status = 0;
            status =
                mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER,
                               mos7840_port->shadowMCR);

            if (status < 0) {
                  return;
            }
      }

      return;
}

/*****************************************************************************
 * mos7840_unthrottle
 *    this function is called by the tty driver when it wants to resume the data
 *    being read from the port (called after SerialThrottle is called)
 *****************************************************************************/
static void mos7840_unthrottle(struct usb_serial_port *port)
{
      struct tty_struct *tty;
      int status;
      struct moschip_port *mos7840_port = mos7840_get_port_private(port);

      if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
            dbg("%s", "Invalid port \n");
            return;
      }

      if (mos7840_port == NULL)
            return;

      if (!mos7840_port->open) {
            dbg("%s - port not opened", __FUNCTION__);
            return;
      }

      dbg("%s", "Entering .......... \n");

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

      /* if we are implementing XON/XOFF, send the start character */
      if (I_IXOFF(tty)) {
            unsigned char start_char = START_CHAR(tty);
            status = mos7840_write(port, &start_char, 1);
            if (status <= 0) {
                  return;
            }
      }

      /* if we are implementing RTS/CTS, toggle that line */
      if (tty->termios->c_cflag & CRTSCTS) {
            mos7840_port->shadowMCR |= MCR_RTS;
            status = 0;
            status =
                mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER,
                               mos7840_port->shadowMCR);
            if (status < 0) {
                  return;
            }
      }

      return;
}

static int mos7840_tiocmget(struct usb_serial_port *port, struct file *file)
{
      struct moschip_port *mos7840_port;
      unsigned int result;
      __u16 msr;
      __u16 mcr;
      int status = 0;
      mos7840_port = mos7840_get_port_private(port);

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

      if (mos7840_port == NULL)
            return -ENODEV;

      status = mos7840_get_uart_reg(port, MODEM_STATUS_REGISTER, &msr);
      status = mos7840_get_uart_reg(port, MODEM_CONTROL_REGISTER, &mcr);
      result = ((mcr & MCR_DTR) ? TIOCM_DTR : 0)
          | ((mcr & MCR_RTS) ? TIOCM_RTS : 0)
          | ((mcr & MCR_LOOPBACK) ? TIOCM_LOOP : 0)
          | ((msr & MOS7840_MSR_CTS) ? TIOCM_CTS : 0)
          | ((msr & MOS7840_MSR_CD) ? TIOCM_CAR : 0)
          | ((msr & MOS7840_MSR_RI) ? TIOCM_RI : 0)
          | ((msr & MOS7840_MSR_DSR) ? TIOCM_DSR : 0);

      dbg("%s - 0x%04X", __FUNCTION__, result);

      return result;
}

static int mos7840_tiocmset(struct usb_serial_port *port, struct file *file,
                      unsigned int set, unsigned int clear)
{
      struct moschip_port *mos7840_port;
      unsigned int mcr;
      unsigned int status;

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

      mos7840_port = mos7840_get_port_private(port);

      if (mos7840_port == NULL)
            return -ENODEV;

      mcr = mos7840_port->shadowMCR;
      if (clear & TIOCM_RTS)
            mcr &= ~MCR_RTS;
      if (clear & TIOCM_DTR)
            mcr &= ~MCR_DTR;
      if (clear & TIOCM_LOOP)
            mcr &= ~MCR_LOOPBACK;

      if (set & TIOCM_RTS)
            mcr |= MCR_RTS;
      if (set & TIOCM_DTR)
            mcr |= MCR_DTR;
      if (set & TIOCM_LOOP)
            mcr |= MCR_LOOPBACK;

      mos7840_port->shadowMCR = mcr;

      status = 0;
      status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, mcr);
      if (status < 0) {
            dbg("setting MODEM_CONTROL_REGISTER Failed\n");
            return -1;
      }

      return 0;
}

/*****************************************************************************
 * mos7840_calc_baud_rate_divisor
 *    this function calculates the proper baud rate divisor for the specified
 *    baud rate.
 *****************************************************************************/
static int mos7840_calc_baud_rate_divisor(int baudRate, int *divisor,
                                __u16 * clk_sel_val)
{

      dbg("%s - %d", __FUNCTION__, baudRate);

      if (baudRate <= 115200) {
            *divisor = 115200 / baudRate;
            *clk_sel_val = 0x0;
      }
      if ((baudRate > 115200) && (baudRate <= 230400)) {
            *divisor = 230400 / baudRate;
            *clk_sel_val = 0x10;
      } else if ((baudRate > 230400) && (baudRate <= 403200)) {
            *divisor = 403200 / baudRate;
            *clk_sel_val = 0x20;
      } else if ((baudRate > 403200) && (baudRate <= 460800)) {
            *divisor = 460800 / baudRate;
            *clk_sel_val = 0x30;
      } else if ((baudRate > 460800) && (baudRate <= 806400)) {
            *divisor = 806400 / baudRate;
            *clk_sel_val = 0x40;
      } else if ((baudRate > 806400) && (baudRate <= 921600)) {
            *divisor = 921600 / baudRate;
            *clk_sel_val = 0x50;
      } else if ((baudRate > 921600) && (baudRate <= 1572864)) {
            *divisor = 1572864 / baudRate;
            *clk_sel_val = 0x60;
      } else if ((baudRate > 1572864) && (baudRate <= 3145728)) {
            *divisor = 3145728 / baudRate;
            *clk_sel_val = 0x70;
      }
      return 0;

#ifdef NOTMCS7840

      for (i = 0; i < ARRAY_SIZE(mos7840_divisor_table); i++) {
            if (mos7840_divisor_table[i].BaudRate == baudrate) {
                  *divisor = mos7840_divisor_table[i].Divisor;
                  return 0;
            }
      }

      /* After trying for all the standard baud rates    *
       * Try calculating the divisor for this baud rate  */

      if (baudrate > 75 && baudrate < 230400) {
            /* get the divisor */
            custom = (__u16) (230400L / baudrate);

            /* Check for round off */
            round1 = (__u16) (2304000L / baudrate);
            round = (__u16) (round1 - (custom * 10));
            if (round > 4) {
                  custom++;
            }
            *divisor = custom;

            dbg(" Baud %d = %d\n", baudrate, custom);
            return 0;
      }

      dbg("%s\n", " Baud calculation Failed...");
      return -1;
#endif
}

/*****************************************************************************
 * mos7840_send_cmd_write_baud_rate
 *    this function sends the proper command to change the baud rate of the
 *    specified port.
 *****************************************************************************/

static int mos7840_send_cmd_write_baud_rate(struct moschip_port *mos7840_port,
                                  int baudRate)
{
      int divisor = 0;
      int status;
      __u16 Data;
      unsigned char number;
      __u16 clk_sel_val;
      struct usb_serial_port *port;

      if (mos7840_port == NULL)
            return -1;

      port = (struct usb_serial_port *)mos7840_port->port;
      if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
            dbg("%s", "Invalid port \n");
            return -1;
      }

      if (mos7840_serial_paranoia_check(port->serial, __FUNCTION__)) {
            dbg("%s", "Invalid Serial \n");
            return -1;
      }

      dbg("%s", "Entering .......... \n");

      number = mos7840_port->port->number - mos7840_port->port->serial->minor;

      dbg("%s - port = %d, baud = %d", __FUNCTION__,
          mos7840_port->port->number, baudRate);
      //reset clk_uart_sel in spregOffset
      if (baudRate > 115200) {
#ifdef HW_flow_control
            //NOTE: need to see the pther register to modify
            //setting h/w flow control bit to 1;
            status = 0;
            Data = 0x2b;
            mos7840_port->shadowMCR = Data;
            status =
                mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
            if (status < 0) {
                  dbg("Writing spreg failed in set_serial_baud\n");
                  return -1;
            }
#endif

      } else {
#ifdef HW_flow_control
            //setting h/w flow control bit to 0;
            status = 0;
            Data = 0xb;
            mos7840_port->shadowMCR = Data;
            status =
                mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
            if (status < 0) {
                  dbg("Writing spreg failed in set_serial_baud\n");
                  return -1;
            }
#endif

      }

      if (1)                  //baudRate <= 115200)
      {
            clk_sel_val = 0x0;
            Data = 0x0;
            status = 0;
            status =
                mos7840_calc_baud_rate_divisor(baudRate, &divisor,
                                       &clk_sel_val);
            status =
                mos7840_get_reg_sync(port, mos7840_port->SpRegOffset,
                               &Data);
            if (status < 0) {
                  dbg("reading spreg failed in set_serial_baud\n");
                  return -1;
            }
            Data = (Data & 0x8f) | clk_sel_val;
            status = 0;
            status =
                mos7840_set_reg_sync(port, mos7840_port->SpRegOffset, Data);
            if (status < 0) {
                  dbg("Writing spreg failed in set_serial_baud\n");
                  return -1;
            }
            /* Calculate the Divisor */

            if (status) {
                  err("%s - bad baud rate", __FUNCTION__);
                  dbg("%s\n", "bad baud rate");
                  return status;
            }
            /* Enable access to divisor latch */
            Data = mos7840_port->shadowLCR | SERIAL_LCR_DLAB;
            mos7840_port->shadowLCR = Data;
            mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);

            /* Write the divisor */
            Data = (unsigned char)(divisor & 0xff);
            dbg("set_serial_baud Value to write DLL is %x\n", Data);
            mos7840_set_uart_reg(port, DIVISOR_LATCH_LSB, Data);

            Data = (unsigned char)((divisor & 0xff00) >> 8);
            dbg("set_serial_baud Value to write DLM is %x\n", Data);
            mos7840_set_uart_reg(port, DIVISOR_LATCH_MSB, Data);

            /* Disable access to divisor latch */
            Data = mos7840_port->shadowLCR & ~SERIAL_LCR_DLAB;
            mos7840_port->shadowLCR = Data;
            mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);

      }

      return status;
}

/*****************************************************************************
 * mos7840_change_port_settings
 *    This routine is called to set the UART on the device to match
 *      the specified new settings.
 *****************************************************************************/

static void mos7840_change_port_settings(struct moschip_port *mos7840_port,
                               struct ktermios *old_termios)
{
      struct tty_struct *tty;
      int baud;
      unsigned cflag;
      unsigned iflag;
      __u8 lData;
      __u8 lParity;
      __u8 lStop;
      int status;
      __u16 Data;
      struct usb_serial_port *port;
      struct usb_serial *serial;

      if (mos7840_port == NULL)
            return;

      port = (struct usb_serial_port *)mos7840_port->port;

      if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
            dbg("%s", "Invalid port \n");
            return;
      }

      if (mos7840_serial_paranoia_check(port->serial, __FUNCTION__)) {
            dbg("%s", "Invalid Serial \n");
            return;
      }

      serial = port->serial;

      dbg("%s - port %d", __FUNCTION__, mos7840_port->port->number);

      if (!mos7840_port->open) {
            dbg("%s - port not opened", __FUNCTION__);
            return;
      }

      tty = mos7840_port->port->tty;

      dbg("%s", "Entering .......... \n");

      lData = LCR_BITS_8;
      lStop = LCR_STOP_1;
      lParity = LCR_PAR_NONE;

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

      /* Change the number of bits */
      if (cflag & CSIZE) {
            switch (cflag & CSIZE) {
            case CS5:
                  lData = LCR_BITS_5;
                  break;

            case CS6:
                  lData = LCR_BITS_6;
                  break;

            case CS7:
                  lData = LCR_BITS_7;
                  break;
            default:
            case CS8:
                  lData = LCR_BITS_8;
                  break;
            }
      }
      /* Change the Parity bit */
      if (cflag & PARENB) {
            if (cflag & PARODD) {
                  lParity = LCR_PAR_ODD;
                  dbg("%s - parity = odd", __FUNCTION__);
            } else {
                  lParity = LCR_PAR_EVEN;
                  dbg("%s - parity = even", __FUNCTION__);
            }

      } else {
            dbg("%s - parity = none", __FUNCTION__);
      }

      if (cflag & CMSPAR) {
            lParity = lParity | 0x20;
      }

      /* Change the Stop bit */
      if (cflag & CSTOPB) {
            lStop = LCR_STOP_2;
            dbg("%s - stop bits = 2", __FUNCTION__);
      } else {
            lStop = LCR_STOP_1;
            dbg("%s - stop bits = 1", __FUNCTION__);
      }

      /* Update the LCR with the correct value */
      mos7840_port->shadowLCR &=
          ~(LCR_BITS_MASK | LCR_STOP_MASK | LCR_PAR_MASK);
      mos7840_port->shadowLCR |= (lData | lParity | lStop);

      dbg("mos7840_change_port_settings mos7840_port->shadowLCR is %x\n",
          mos7840_port->shadowLCR);
      /* Disable Interrupts */
      Data = 0x00;
      mos7840_set_uart_reg(port, INTERRUPT_ENABLE_REGISTER, Data);

      Data = 0x00;
      mos7840_set_uart_reg(port, FIFO_CONTROL_REGISTER, Data);

      Data = 0xcf;
      mos7840_set_uart_reg(port, FIFO_CONTROL_REGISTER, Data);

      /* Send the updated LCR value to the mos7840 */
      Data = mos7840_port->shadowLCR;

      mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);

      Data = 0x00b;
      mos7840_port->shadowMCR = Data;
      mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
      Data = 0x00b;
      mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);

      /* set up the MCR register and send it to the mos7840 */

      mos7840_port->shadowMCR = MCR_MASTER_IE;
      if (cflag & CBAUD) {
            mos7840_port->shadowMCR |= (MCR_DTR | MCR_RTS);
      }

      if (cflag & CRTSCTS) {
            mos7840_port->shadowMCR |= (MCR_XON_ANY);

      } else {
            mos7840_port->shadowMCR &= ~(MCR_XON_ANY);
      }

      Data = mos7840_port->shadowMCR;
      mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);

      /* Determine divisor based on baud rate */
      baud = tty_get_baud_rate(tty);

      if (!baud) {
            /* pick a default, any default... */
            dbg("%s\n", "Picked default baud...");
            baud = 9600;
      }

      dbg("%s - baud rate = %d", __FUNCTION__, baud);
      status = mos7840_send_cmd_write_baud_rate(mos7840_port, baud);

      /* Enable Interrupts */
      Data = 0x0c;
      mos7840_set_uart_reg(port, INTERRUPT_ENABLE_REGISTER, Data);

      if (mos7840_port->read_urb->status != -EINPROGRESS) {
            mos7840_port->read_urb->dev = serial->dev;

            status = usb_submit_urb(mos7840_port->read_urb, GFP_ATOMIC);

            if (status) {
                  dbg(" usb_submit_urb(read bulk) failed, status = %d",
                      status);
            }
      }
      wake_up(&mos7840_port->delta_msr_wait);
      mos7840_port->delta_msr_cond = 1;
      dbg("mos7840_change_port_settings mos7840_port->shadowLCR is End %x\n",
          mos7840_port->shadowLCR);

      return;
}

/*****************************************************************************
 * mos7840_set_termios
 *    this function is called by the tty driver when it wants to change
 *    the termios structure
 *****************************************************************************/

static void mos7840_set_termios(struct usb_serial_port *port,
                        struct ktermios *old_termios)
{
      int status;
      unsigned int cflag;
      struct usb_serial *serial;
      struct moschip_port *mos7840_port;
      struct tty_struct *tty;
      dbg("mos7840_set_termios: START\n");
      if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
            dbg("%s", "Invalid port \n");
            return;
      }

      serial = port->serial;

      if (mos7840_serial_paranoia_check(serial, __FUNCTION__)) {
            dbg("%s", "Invalid Serial \n");
            return;
      }

      mos7840_port = mos7840_get_port_private(port);

      if (mos7840_port == NULL)
            return;

      tty = port->tty;

      if (!mos7840_port->open) {
            dbg("%s - port not opened", __FUNCTION__);
            return;
      }

      dbg("%s\n", "setting termios - ");

      cflag = tty->termios->c_cflag;

      dbg("%s - clfag %08x iflag %08x", __FUNCTION__,
          tty->termios->c_cflag, RELEVANT_IFLAG(tty->termios->c_iflag));
      dbg("%s - old clfag %08x old iflag %08x", __FUNCTION__,
          old_termios->c_cflag, RELEVANT_IFLAG(old_termios->c_iflag));
      dbg("%s - port %d", __FUNCTION__, port->number);

      /* change the port settings to the new ones specified */

      mos7840_change_port_settings(mos7840_port, old_termios);

      if (!mos7840_port->read_urb) {
            dbg("%s", "URB KILLED !!!!!\n");
            return;
      }

      if (mos7840_port->read_urb->status != -EINPROGRESS) {
            mos7840_port->read_urb->dev = serial->dev;
            status = usb_submit_urb(mos7840_port->read_urb, GFP_ATOMIC);
            if (status) {
                  dbg(" usb_submit_urb(read bulk) failed, status = %d",
                      status);
            }
      }
      return;
}

/*****************************************************************************
 * mos7840_get_lsr_info - get line status register info
 *
 * Purpose: Let user call ioctl() to get info when the UART physically
 *        is emptied.  On bus types like RS485, the transmitter must
 *        release the bus after transmitting. This must be done when
 *        the transmit shift register is empty, not be done when the
 *        transmit holding register is empty.  This functionality
 *        allows an RS485 driver to be written in user space.
 *****************************************************************************/

static int mos7840_get_lsr_info(struct moschip_port *mos7840_port,
                        unsigned int __user *value)
{
      int count;
      unsigned int result = 0;

      count = mos7840_chars_in_buffer(mos7840_port->port);
      if (count == 0) {
            dbg("%s -- Empty", __FUNCTION__);
            result = TIOCSER_TEMT;
      }

      if (copy_to_user(value, &result, sizeof(int)))
            return -EFAULT;
      return 0;
}

/*****************************************************************************
 * mos7840_set_modem_info
 *      function to set modem info
 *****************************************************************************/

static int mos7840_set_modem_info(struct moschip_port *mos7840_port,
                          unsigned int cmd, unsigned int __user *value)
{
      unsigned int mcr;
      unsigned int arg;
      __u16 Data;
      int status;
      struct usb_serial_port *port;

      if (mos7840_port == NULL)
            return -1;

      port = (struct usb_serial_port *)mos7840_port->port;
      if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
            dbg("%s", "Invalid port \n");
            return -1;
      }

      mcr = mos7840_port->shadowMCR;

      if (copy_from_user(&arg, value, sizeof(int)))
            return -EFAULT;

      switch (cmd) {
      case TIOCMBIS:
            if (arg & TIOCM_RTS)
                  mcr |= MCR_RTS;
            if (arg & TIOCM_DTR)
                  mcr |= MCR_RTS;
            if (arg & TIOCM_LOOP)
                  mcr |= MCR_LOOPBACK;
            break;

      case TIOCMBIC:
            if (arg & TIOCM_RTS)
                  mcr &= ~MCR_RTS;
            if (arg & TIOCM_DTR)
                  mcr &= ~MCR_RTS;
            if (arg & TIOCM_LOOP)
                  mcr &= ~MCR_LOOPBACK;
            break;

      case TIOCMSET:
            /* turn off the RTS and DTR and LOOPBACK
             * and then only turn on what was asked to */
            mcr &= ~(MCR_RTS | MCR_DTR | MCR_LOOPBACK);
            mcr |= ((arg & TIOCM_RTS) ? MCR_RTS : 0);
            mcr |= ((arg & TIOCM_DTR) ? MCR_DTR : 0);
            mcr |= ((arg & TIOCM_LOOP) ? MCR_LOOPBACK : 0);
            break;
      }

      mos7840_port->shadowMCR = mcr;

      Data = mos7840_port->shadowMCR;
      status = 0;
      status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
      if (status < 0) {
            dbg("setting MODEM_CONTROL_REGISTER Failed\n");
            return -1;
      }

      return 0;
}

/*****************************************************************************
 * mos7840_get_modem_info
 *      function to get modem info
 *****************************************************************************/

static int mos7840_get_modem_info(struct moschip_port *mos7840_port,
                          unsigned int __user *value)
{
      unsigned int result = 0;
      __u16 msr;
      unsigned int mcr = mos7840_port->shadowMCR;
      int status = 0;
      status =
          mos7840_get_uart_reg(mos7840_port->port, MODEM_STATUS_REGISTER,
                         &msr);
      result = ((mcr & MCR_DTR) ? TIOCM_DTR : 0)      /* 0x002 */
          |((mcr & MCR_RTS) ? TIOCM_RTS : 0)    /* 0x004 */
          |((msr & MOS7840_MSR_CTS) ? TIOCM_CTS : 0)  /* 0x020 */
          |((msr & MOS7840_MSR_CD) ? TIOCM_CAR : 0)   /* 0x040 */
          |((msr & MOS7840_MSR_RI) ? TIOCM_RI : 0)    /* 0x080 */
          |((msr & MOS7840_MSR_DSR) ? TIOCM_DSR : 0); /* 0x100 */

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

      if (copy_to_user(value, &result, sizeof(int)))
            return -EFAULT;
      return 0;
}

/*****************************************************************************
 * mos7840_get_serial_info
 *      function to get information about serial port
 *****************************************************************************/

static int mos7840_get_serial_info(struct moschip_port *mos7840_port,
                           struct serial_struct __user *retinfo)
{
      struct serial_struct tmp;

      if (mos7840_port == NULL)
            return -1;

      if (!retinfo)
            return -EFAULT;

      memset(&tmp, 0, sizeof(tmp));

      tmp.type = PORT_16550A;
      tmp.line = mos7840_port->port->serial->minor;
      tmp.port = mos7840_port->port->number;
      tmp.irq = 0;
      tmp.flags = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
      tmp.xmit_fifo_size = NUM_URBS * URB_TRANSFER_BUFFER_SIZE;
      tmp.baud_base = 9600;
      tmp.close_delay = 5 * HZ;
      tmp.closing_wait = 30 * HZ;

      if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
            return -EFAULT;
      return 0;
}

/*****************************************************************************
 * SerialIoctl
 *    this function handles any ioctl calls to the driver
 *****************************************************************************/

static int mos7840_ioctl(struct usb_serial_port *port, struct file *file,
                   unsigned int cmd, unsigned long arg)
{
      void __user *argp = (void __user *)arg;
      struct moschip_port *mos7840_port;
      struct tty_struct *tty;

      struct async_icount cnow;
      struct async_icount cprev;
      struct serial_icounter_struct icount;
      int mosret = 0;

      if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
            dbg("%s", "Invalid port \n");
            return -1;
      }

      mos7840_port = mos7840_get_port_private(port);

      if (mos7840_port == NULL)
            return -1;

      tty = mos7840_port->port->tty;

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

      switch (cmd) {
            /* return number of bytes available */

      case TIOCSERGETLSR:
            dbg("%s (%d) TIOCSERGETLSR", __FUNCTION__, port->number);
            return mos7840_get_lsr_info(mos7840_port, argp);
            return 0;

      case TIOCMBIS:
      case TIOCMBIC:
      case TIOCMSET:
            dbg("%s (%d) TIOCMSET/TIOCMBIC/TIOCMSET", __FUNCTION__,
                port->number);
            mosret =
                mos7840_set_modem_info(mos7840_port, cmd, argp);
            return mosret;

      case TIOCMGET:
            dbg("%s (%d) TIOCMGET", __FUNCTION__, port->number);
            return mos7840_get_modem_info(mos7840_port, argp);

      case TIOCGSERIAL:
            dbg("%s (%d) TIOCGSERIAL", __FUNCTION__, port->number);
            return mos7840_get_serial_info(mos7840_port, argp);

      case TIOCSSERIAL:
            dbg("%s (%d) TIOCSSERIAL", __FUNCTION__, port->number);
            break;

      case TIOCMIWAIT:
            dbg("%s (%d) TIOCMIWAIT", __FUNCTION__, port->number);
            cprev = mos7840_port->icount;
            while (1) {
                  //interruptible_sleep_on(&mos7840_port->delta_msr_wait);
                  mos7840_port->delta_msr_cond = 0;
                  wait_event_interruptible(mos7840_port->delta_msr_wait,
                                     (mos7840_port->
                                      delta_msr_cond == 1));

                  /* see if a signal did it */
                  if (signal_pending(current))
                        return -ERESTARTSYS;
                  cnow = mos7840_port->icount;
                  smp_rmb();
                  if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
                      cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
                        return -EIO;      /* no change => error */
                  if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
                      ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
                      ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
                      ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
                        return 0;
                  }
                  cprev = cnow;
            }
            /* NOTREACHED */
            break;

      case TIOCGICOUNT:
            cnow = mos7840_port->icount;
            smp_rmb();
            icount.cts = cnow.cts;
            icount.dsr = cnow.dsr;
            icount.rng = cnow.rng;
            icount.dcd = cnow.dcd;
            icount.rx = cnow.rx;
            icount.tx = cnow.tx;
            icount.frame = cnow.frame;
            icount.overrun = cnow.overrun;
            icount.parity = cnow.parity;
            icount.brk = cnow.brk;
            icount.buf_overrun = cnow.buf_overrun;

            dbg("%s (%d) TIOCGICOUNT RX=%d, TX=%d", __FUNCTION__,
                port->number, icount.rx, icount.tx);
            if (copy_to_user(argp, &icount, sizeof(icount)))
                  return -EFAULT;
            return 0;

      case TIOCEXBAUD:
            return 0;
      default:
            break;
      }

      return -ENOIOCTLCMD;
}

static int mos7840_calc_num_ports(struct usb_serial *serial)
{
      int mos7840_num_ports = 0;

      dbg("numberofendpoints: %d \n",
          (int)serial->interface->cur_altsetting->desc.bNumEndpoints);
      dbg("numberofendpoints: %d \n",
          (int)serial->interface->altsetting->desc.bNumEndpoints);
      if (serial->interface->cur_altsetting->desc.bNumEndpoints == 5) {
            mos7840_num_ports = serial->num_ports = 2;
      } else if (serial->interface->cur_altsetting->desc.bNumEndpoints == 9) {
            serial->num_bulk_in = 4;
            serial->num_bulk_out = 4;
            mos7840_num_ports = serial->num_ports = 4;
      }

      return mos7840_num_ports;
}

/****************************************************************************
 * mos7840_startup
 ****************************************************************************/

static int mos7840_startup(struct usb_serial *serial)
{
      struct moschip_port *mos7840_port;
      struct usb_device *dev;
      int i, status;

      __u16 Data;
      dbg("%s \n", " mos7840_startup :entering..........");

      if (!serial) {
            dbg("%s\n", "Invalid Handler");
            return -1;
      }

      dev = serial->dev;

      dbg("%s\n", "Entering...");

      /* we set up the pointers to the endpoints in the mos7840_open *
       * function, as the structures aren't created yet.             */

      /* set up port private structures */
      for (i = 0; i < serial->num_ports; ++i) {
            mos7840_port = kzalloc(sizeof(struct moschip_port), GFP_KERNEL);
            if (mos7840_port == NULL) {
                  err("%s - Out of memory", __FUNCTION__);
                  status = -ENOMEM;
                  i--; /* don't follow NULL pointer cleaning up */
                  goto error;
            }

            /* Initialize all port interrupt end point to port 0 int endpoint *
             * Our device has only one interrupt end point comman to all port */

            mos7840_port->port = serial->port[i];
            mos7840_set_port_private(serial->port[i], mos7840_port);
            spin_lock_init(&mos7840_port->pool_lock);

            mos7840_port->port_num = ((serial->port[i]->number -
                                 (serial->port[i]->serial->minor)) +
                                1);

            if (mos7840_port->port_num == 1) {
                  mos7840_port->SpRegOffset = 0x0;
                  mos7840_port->ControlRegOffset = 0x1;
                  mos7840_port->DcrRegOffset = 0x4;
            } else if ((mos7840_port->port_num == 2)
                     && (serial->num_ports == 4)) {
                  mos7840_port->SpRegOffset = 0x8;
                  mos7840_port->ControlRegOffset = 0x9;
                  mos7840_port->DcrRegOffset = 0x16;
            } else if ((mos7840_port->port_num == 2)
                     && (serial->num_ports == 2)) {
                  mos7840_port->SpRegOffset = 0xa;
                  mos7840_port->ControlRegOffset = 0xb;
                  mos7840_port->DcrRegOffset = 0x19;
            } else if ((mos7840_port->port_num == 3)
                     && (serial->num_ports == 4)) {
                  mos7840_port->SpRegOffset = 0xa;
                  mos7840_port->ControlRegOffset = 0xb;
                  mos7840_port->DcrRegOffset = 0x19;
            } else if ((mos7840_port->port_num == 4)
                     && (serial->num_ports == 4)) {
                  mos7840_port->SpRegOffset = 0xc;
                  mos7840_port->ControlRegOffset = 0xd;
                  mos7840_port->DcrRegOffset = 0x1c;
            }
            mos7840_dump_serial_port(mos7840_port);

            mos7840_set_port_private(serial->port[i], mos7840_port);

            //enable rx_disable bit in control register

            status =
                mos7840_get_reg_sync(serial->port[i],
                               mos7840_port->ControlRegOffset, &Data);
            if (status < 0) {
                  dbg("Reading ControlReg failed status-0x%x\n", status);
                  break;
            } else
                  dbg("ControlReg Reading success val is %x, status%d\n",
                      Data, status);
            Data |= 0x08;     //setting driver done bit
            Data |= 0x04;     //sp1_bit to have cts change reflect in modem status reg

            //Data |= 0x20; //rx_disable bit
            status = 0;
            status =
                mos7840_set_reg_sync(serial->port[i],
                               mos7840_port->ControlRegOffset, Data);
            if (status < 0) {
                  dbg("Writing ControlReg failed(rx_disable) status-0x%x\n", status);
                  break;
            } else
                  dbg("ControlReg Writing success(rx_disable) status%d\n",
                      status);

            //Write default values in DCR (i.e 0x01 in DCR0, 0x05 in DCR2 and 0x24 in DCR3
            Data = 0x01;
            status = 0;
            status =
                mos7840_set_reg_sync(serial->port[i],
                               (__u16) (mos7840_port->DcrRegOffset +
                                      0), Data);
            if (status < 0) {
                  dbg("Writing DCR0 failed status-0x%x\n", status);
                  break;
            } else
                  dbg("DCR0 Writing success status%d\n", status);

            Data = 0x05;
            status = 0;
            status =
                mos7840_set_reg_sync(serial->port[i],
                               (__u16) (mos7840_port->DcrRegOffset +
                                      1), Data);
            if (status < 0) {
                  dbg("Writing DCR1 failed status-0x%x\n", status);
                  break;
            } else
                  dbg("DCR1 Writing success status%d\n", status);

            Data = 0x24;
            status = 0;
            status =
                mos7840_set_reg_sync(serial->port[i],
                               (__u16) (mos7840_port->DcrRegOffset +
                                      2), Data);
            if (status < 0) {
                  dbg("Writing DCR2 failed status-0x%x\n", status);
                  break;
            } else
                  dbg("DCR2 Writing success status%d\n", status);

            // write values in clkstart0x0 and clkmulti 0x20
            Data = 0x0;
            status = 0;
            status =
                mos7840_set_reg_sync(serial->port[i],
                               CLK_START_VALUE_REGISTER, Data);
            if (status < 0) {
                  dbg("Writing CLK_START_VALUE_REGISTER failed status-0x%x\n", status);
                  break;
            } else
                  dbg("CLK_START_VALUE_REGISTER Writing success status%d\n", status);

            Data = 0x20;
            status =
                mos7840_set_reg_sync(serial->port[i], CLK_MULTI_REGISTER,
                               Data);
            if (status < 0) {
                  dbg("Writing CLK_MULTI_REGISTER failed status-0x%x\n",
                      status);
                  goto error;
            } else
                  dbg("CLK_MULTI_REGISTER Writing success status%d\n",
                      status);

            //write value 0x0 to scratchpad register
            Data = 0x00;
            status =
                mos7840_set_uart_reg(serial->port[i], SCRATCH_PAD_REGISTER,
                               Data);
            if (status < 0) {
                  dbg("Writing SCRATCH_PAD_REGISTER failed status-0x%x\n",
                      status);
                  break;
            } else
                  dbg("SCRATCH_PAD_REGISTER Writing success status%d\n",
                      status);

            //Zero Length flag register
            if ((mos7840_port->port_num != 1)
                && (serial->num_ports == 2)) {

                  Data = 0xff;
                  status = 0;
                  status = mos7840_set_reg_sync(serial->port[i],
                                          (__u16) (ZLP_REG1 +
                                                 ((__u16)
                                                mos7840_port->
                                                port_num)),
                                          Data);
                  dbg("ZLIP offset%x\n",
                      (__u16) (ZLP_REG1 +
                             ((__u16) mos7840_port->port_num)));
                  if (status < 0) {
                        dbg("Writing ZLP_REG%d failed status-0x%x\n",
                            i + 2, status);
                        break;
                  } else
                        dbg("ZLP_REG%d Writing success status%d\n",
                            i + 2, status);
            } else {
                  Data = 0xff;
                  status = 0;
                  status = mos7840_set_reg_sync(serial->port[i],
                                          (__u16) (ZLP_REG1 +
                                                 ((__u16)
                                                mos7840_port->
                                                port_num) -
                                                 0x1), Data);
                  dbg("ZLIP offset%x\n",
                      (__u16) (ZLP_REG1 +
                             ((__u16) mos7840_port->port_num) - 0x1));
                  if (status < 0) {
                        dbg("Writing ZLP_REG%d failed status-0x%x\n",
                            i + 1, status);
                        break;
                  } else
                        dbg("ZLP_REG%d Writing success status%d\n",
                            i + 1, status);

            }
            mos7840_port->control_urb = usb_alloc_urb(0, GFP_KERNEL);
            mos7840_port->ctrl_buf = kmalloc(16, GFP_KERNEL);
            mos7840_port->dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
            if (!mos7840_port->control_urb || !mos7840_port->ctrl_buf || !mos7840_port->dr) {
                  status = -ENOMEM;
                  goto error;
            }
      }

      //Zero Length flag enable
      Data = 0x0f;
      status = mos7840_set_reg_sync(serial->port[0], ZLP_REG5, Data);
      if (status < 0) {
            dbg("Writing ZLP_REG5 failed status-0x%x\n", status);
            goto error;
      } else
            dbg("ZLP_REG5 Writing success status%d\n", status);

      /* setting configuration feature to one */
      usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
                  (__u8) 0x03, 0x00, 0x01, 0x00, NULL, 0x00, 5 * HZ);
      return 0;
error:
      for (/* nothing */; i >= 0; i--) {
            mos7840_port = mos7840_get_port_private(serial->port[i]);

            kfree(mos7840_port->dr);
            kfree(mos7840_port->ctrl_buf);
            usb_free_urb(mos7840_port->control_urb);
            kfree(mos7840_port);
            serial->port[i] = NULL;
      }
      return status;
}

/****************************************************************************
 * mos7840_shutdown
 *    This function is called whenever the device is removed from the usb bus.
 ****************************************************************************/

static void mos7840_shutdown(struct usb_serial *serial)
{
      int i;
      unsigned long flags;
      struct moschip_port *mos7840_port;
      dbg("%s \n", " shutdown :entering..........");

      if (!serial) {
            dbg("%s", "Invalid Handler \n");
            return;
      }

      /*      check for the ports to be closed,close the ports and disconnect         */

      /* free private structure allocated for serial port  *
       * stop reads and writes on all ports                */

      for (i = 0; i < serial->num_ports; ++i) {
            mos7840_port = mos7840_get_port_private(serial->port[i]);
            spin_lock_irqsave(&mos7840_port->pool_lock, flags);
            mos7840_port->zombie = 1;
            spin_unlock_irqrestore(&mos7840_port->pool_lock, flags);
            usb_kill_urb(mos7840_port->control_urb);
            kfree(mos7840_port->ctrl_buf);
            kfree(mos7840_port->dr);
            kfree(mos7840_port);
            mos7840_set_port_private(serial->port[i], NULL);
      }

      dbg("%s\n", "Thank u :: ");

}

static struct usb_driver io_driver = {
      .name = "mos7840",
      .probe = usb_serial_probe,
      .disconnect = usb_serial_disconnect,
      .id_table = moschip_id_table_combined,
      .no_dynamic_id = 1,
};

static struct usb_serial_driver moschip7840_4port_device = {
      .driver = {
               .owner = THIS_MODULE,
               .name = "mos7840",
               },
      .description = DRIVER_DESC,
      .usb_driver = &io_driver,
      .id_table = moschip_port_id_table,
      .num_interrupt_in = 1,  //NUM_DONT_CARE,//1,
#ifdef check
      .num_bulk_in = 4,
      .num_bulk_out = 4,
      .num_ports = 4,
#endif
      .open = mos7840_open,
      .close = mos7840_close,
      .write = mos7840_write,
      .write_room = mos7840_write_room,
      .chars_in_buffer = mos7840_chars_in_buffer,
      .throttle = mos7840_throttle,
      .unthrottle = mos7840_unthrottle,
      .calc_num_ports = mos7840_calc_num_ports,
#ifdef MCSSerialProbe
      .probe = mos7840_serial_probe,
#endif
      .ioctl = mos7840_ioctl,
      .set_termios = mos7840_set_termios,
      .break_ctl = mos7840_break,
      .tiocmget = mos7840_tiocmget,
      .tiocmset = mos7840_tiocmset,
      .attach = mos7840_startup,
      .shutdown = mos7840_shutdown,
      .read_bulk_callback = mos7840_bulk_in_callback,
      .read_int_callback = mos7840_interrupt_callback,
};

/****************************************************************************
 * moschip7840_init
 *    This is called by the module subsystem, or on startup to initialize us
 ****************************************************************************/
static int __init moschip7840_init(void)
{
      int retval;

      dbg("%s \n", " mos7840_init :entering..........");

      /* Register with the usb serial */
      retval = usb_serial_register(&moschip7840_4port_device);

      if (retval)
            goto failed_port_device_register;

      dbg("%s\n", "Entring...");
      info(DRIVER_DESC " " DRIVER_VERSION);

      /* Register with the usb */
      retval = usb_register(&io_driver);

      if (retval)
            goto failed_usb_register;

      if (retval == 0) {
            dbg("%s\n", "Leaving...");
            return 0;
      }

      failed_usb_register:
      usb_serial_deregister(&moschip7840_4port_device);

      failed_port_device_register:

      return retval;
}

/****************************************************************************
 * moschip7840_exit
 *    Called when the driver is about to be unloaded.
 ****************************************************************************/
static void __exit moschip7840_exit(void)
{

      dbg("%s \n", " mos7840_exit :entering..........");

      usb_deregister(&io_driver);

      usb_serial_deregister(&moschip7840_4port_device);

      dbg("%s\n", "Entring...");
}

module_init(moschip7840_init);
module_exit(moschip7840_exit);

/* Module information */
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");

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