USB: Moschip 7840 USB-Serial Driver

Signed-off-by: Paul B Schroeder <pschroeder@uplogix.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 2978 insertions, 0 deletions

diff --git a/drivers/usb/serial/Kconfig b/drivers/usb/serial/Kconfig
index e4df0ac358f..5076b9d9705 100644
--- a/drivers/usb/serial/Kconfig
+++ b/drivers/usb/serial/Kconfig
@@ -422,6 +422,21 @@ config USB_SERIAL_MCT_U232
 	  To compile this driver as a module, choose M here: the
 	  module will be called mct_u232.
 
+config USB_SERIAL_MOS7840
+	tristate "USB Moschip 7840/7820 USB Serial Driver"
+	depends on USB_SERIAL
+	---help---
+	  Say Y here if you want to use a MCS7840 Quad-Serial or MCS7820
+	  Dual-Serial port device from MosChip Semiconductor.
+
+	  The MCS7840 and MCS7820 have been developed to connect a wide range
+	  of standard serial devices to a USB host.  The MCS7840 has a USB
+	  device controller connected to four (4) individual UARTs while the
+	  MCS7820 controller connects to two (2) individual UARTs.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called mos7840.  If unsure, choose N.
+
 config USB_SERIAL_NAVMAN
 	tristate "USB Navman GPS device"
 	depends on USB_SERIAL
diff --git a/drivers/usb/serial/Makefile b/drivers/usb/serial/Makefile
index 029e2a1d7bf..8dce83340e3 100644
--- a/drivers/usb/serial/Makefile
+++ b/drivers/usb/serial/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_USB_SERIAL_KEYSPAN_PDA)		+= keyspan_pda.o
 obj-$(CONFIG_USB_SERIAL_KLSI)			+= kl5kusb105.o
 obj-$(CONFIG_USB_SERIAL_KOBIL_SCT)		+= kobil_sct.o
 obj-$(CONFIG_USB_SERIAL_MCT_U232)		+= mct_u232.o
+obj-$(CONFIG_USB_SERIAL_MOS7840)		+= mos7840.o
 obj-$(CONFIG_USB_SERIAL_NAVMAN)			+= navman.o
 obj-$(CONFIG_USB_SERIAL_OMNINET)		+= omninet.o
 obj-$(CONFIG_USB_SERIAL_OPTION)			+= option.o
diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
new file mode 100644
index 00000000000..95bf57166c5
--- /dev/null
+++ b/drivers/usb/serial/mos7840.c
@@ -0,0 +1,2962 @@
+/*
+ * 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 */
+	__u8 shadowLCR;		/* last LCR value received */
+	__u8 shadowMCR;		/* last MCR value received */
+	char open;
+	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;
+	char *ctrl_buf;
+	int MsrLsr;
+
+	struct urb *write_urb_pool[NUM_URBS];
+};
+
+
+static int debug;
+static int mos7840_num_ports;	//this says the number of ports in the device
+static int mos7840_num_open_ports;
+
+
+/*
+ * 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 (mos7840_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 (mos7840_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 int 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++;
+		}
+		if (new_msr & MOS_MSR_DELTA_DSR) {
+			icount->dsr++;
+		}
+		if (new_msr & MOS_MSR_DELTA_CD) {
+			icount->dcd++;
+		}
+		if (new_msr & MOS_MSR_DELTA_RI) {
+			icount->rng++;
+		}
+	}
+
+	return 0;
+}
+
+static int 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++;
+	}
+	if (new_lsr & SERIAL_LSR_OE) {
+		icount->overrun++;
+	}
+	if (new_lsr & SERIAL_LSR_PE) {
+		icount->parity++;
+	}
+	if (new_lsr & SERIAL_LSR_FE) {
+		icount->frame++;
+	}
+
+	return 0;
+}
+
+/************************************************************************/
+/************************************************************************/
+/*            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, struct pt_regs *regs)
+{
+	unsigned char *data;
+	struct moschip_port *mos7840_port;
+	__u8 regval = 0x0;
+
+	if (!urb) {
+		dbg("%s", "Invalid Pointer !!!!:\n");
+		return;
+	}
+
+	switch (urb->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__,
+		    urb->status);
+		return;
+	default:
+		dbg("%s - nonzero urb status received: %d", __FUNCTION__,
+		    urb->status);
+		goto exit;
+	}
+
+	mos7840_port = (struct moschip_port *)urb->context;
+
+	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:
+	return;
+}
+
+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 = NULL;
+	unsigned char *buffer = NULL;
+	int ret = 0;
+	buffer = (__u8 *) mcs->ctrl_buf;
+
+//      dr=(struct usb_ctrlrequest *)(buffer);
+	dr = (void *)(buffer + 2);
+	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, struct pt_regs *regs)
+{
+	int result;
+	int length;
+	struct moschip_port *mos7840_port;
+	struct usb_serial *serial;
+	__u16 Data;
+	unsigned char *data;
+	__u8 sp[5], st;
+	int i;
+	__u16 wval;
+
+	dbg("%s", " : Entering\n");
+	if (!urb) {
+		dbg("%s", "Invalid Pointer !!!!:\n");
+		return;
+	}
+
+	switch (urb->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__,
+		    urb->status);
+		return;
+	default:
+		dbg("%s - nonzero urb status received: %d", __FUNCTION__,
+		    urb->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;
+					mos7840_get_reg(mos7840_port, wval,
+							LINE_STATUS_REGISTER,
+							&Data);
+					break;
+				case SERIAL_IIR_MS:
+					dbg("Serial Port %d: Modem status change\n", i);
+					mos7840_port->MsrLsr = 0;
+					mos7840_get_reg(mos7840_port, wval,
+							MODEM_STATUS_REGISTER,
+							&Data);
+					break;
+				}
+			}
+		}
+	}
+      exit:
+	result = usb_submit_urb(urb, GFP_ATOMIC);
+	if (result) {
+		dev_err(&urb->dev->dev,
+			"%s - Error %d submitting interrupt urb\n",
+			__FUNCTION__, result);
+	}
+
+	return;
+
+}
+
+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, struct pt_regs *regs)
+{
+	int status;
+	unsigned char *data;
+	struct usb_serial *serial;
+	struct usb_serial_port *port;
+	struct moschip_port *mos7840_port;
+	struct tty_struct *tty;
+
+	if (!urb) {
+		dbg("%s", "Invalid Pointer !!!!:\n");
+		return;
+	}
+
+	if (urb->status) {
+		dbg("nonzero read bulk status received: %d", urb->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;
+		dbg("mos7840_port->icount.rx is %d:\n",
+		    mos7840_port->icount.rx);
+	}
+
+	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);
+		}
+	}
+}
+
+/*****************************************************************************
+ * 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 pt_regs *regs)
+{
+	struct moschip_port *mos7840_port;
+	struct tty_struct *tty;
+	if (!urb) {
+		dbg("%s", "Invalid Pointer !!!!:\n");
+		return;
+	}
+
+	if (urb->status) {
+		dbg("nonzero write bulk status received:%d\n", urb->status);
+		return;
+	}
+
+	mos7840_port = (struct moschip_port *)urb->context;
+	if (!mos7840_port) {
+		dbg("%s", "NULL mos7840_port pointer \n");
+		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) {
+		/* let the tty driver wakeup if it has a special *
+		 * write_wakeup function                         */
+
+		if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP))
+		    && tty->ldisc.write_wakeup) {
+			(tty->ldisc.write_wakeup) (tty);
+		}
+
+		/* tell the tty driver that something has changed */
+		wake_up_interruptible(&tty->write_wait);
+	}
+
+}
+
+/************************************************************************/
+/*       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;
+
+	if (mos7840_port_paranoia_check(port, __FUNCTION__)) {
+		dbg("%s", "Port Paranoia failed \n");
+		return -ENODEV;
+	}
+
+	mos7840_num_open_ports++;
+	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);
+
+	if (mos7840_port == NULL)
+		return -ENODEV;
+
+	usb_clear_halt(serial->dev, port->write_urb->pipe);
+	usb_clear_halt(serial->dev, port->read_urb->pipe);
+
+	/* Initialising the write urb pool */
+	for (j = 0; j < NUM_URBS; ++j) {
+		urb = usb_alloc_urb(0, SLAB_ATOMIC);
+		mos7840_port->write_urb_pool[j] = urb;
+
+		if (urb == NULL) {
+			err("No more urbs???");
+			continue;
+		}
+
+		urb->transfer_buffer = NULL;
+		urb->transfer_buffer =
+		    kmalloc(URB_TRANSFER_BUFFER_SIZE, GFP_KERNEL);
+		if (!urb->transfer_buffer) {
+			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 = 0;
+	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 = 0;
+	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 = 0;
+	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 = 0;
+	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 = 0;
+	status = mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
+	mos7840_port->shadowLCR = Data;
+
+	Data = 0x0b;
+	status = 0;
+	status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
+	mos7840_port->shadowMCR = Data;
+
+	Data = 0x00;
+	status = 0;
+	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 = 0;
+	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 (mos7840_num_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);