USB: add USB serial mos7720 driver

Add support for Moschip 7720 USB dual port usb to serial device.

This driver is originally based on the drivers/usb/io_edgeport.c driver.

Cleaned up and forward ported by me.

Cc: VijayaKumar <vijaykumar@aspirecom.net>
Cc: AjayKumar <ajay@aspirecom.net>
Cc: Gurudeva <gurudev@aspirecom.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 1694 insertions, 0 deletions

diff --git a/drivers/usb/serial/Kconfig b/drivers/usb/serial/Kconfig
index 5076b9d..8ca6d3f 100644
--- a/drivers/usb/serial/Kconfig
+++ b/drivers/usb/serial/Kconfig
@@ -422,6 +422,16 @@ 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_MOS7720
+	tristate "USB Moschip 7720 Single Port Serial Driver"
+	depends on USB_SERIAL
+	---help---
+	  Say Y here if you want to use a USB Serial single port adapter from
+	  Moschip Semiconductor Tech.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called mos7720.
+
 config USB_SERIAL_MOS7840
 	tristate "USB Moschip 7840/7820 USB Serial Driver"
 	depends on USB_SERIAL
diff --git a/drivers/usb/serial/Makefile b/drivers/usb/serial/Makefile
index 8dce833..a5047dc 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-$(CONFIG_USB_SERIAL_MOS7720)		+= mos7720.o
 obj-$(CONFIG_USB_SERIAL_MOS7840)		+= mos7840.o
 obj-$(CONFIG_USB_SERIAL_NAVMAN)			+= navman.o
 obj-$(CONFIG_USB_SERIAL_OMNINET)		+= omninet.o
diff --git a/drivers/usb/serial/mos7720.c b/drivers/usb/serial/mos7720.c
new file mode 100644
index 0000000..82cd15b
--- /dev/null
+++ b/drivers/usb/serial/mos7720.c
@@ -0,0 +1,1683 @@
+/*
+ * mos7720.c
+ *   Controls the Moschip 7720 usb to dual port serial convertor
+ *
+ * Copyright 2006 Moschip Semiconductor Tech. Ltd.
+ *
+ * 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, version 2 of the License.
+ *
+ * Developed by:
+ * 	VijayaKumar.G.N. <vijaykumar@aspirecom.net>
+ *	AjayKumar <ajay@aspirecom.net>
+ *	Gurudeva.N. <gurudev@aspirecom.net>
+ *
+ * Cleaned up from the original by:
+ *	Greg Kroah-Hartman <gregkh@suse.de>
+ *
+ * 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/spinlock.h>
+#include <linux/serial.h>
+#include <linux/serial_reg.h>
+#include <linux/usb.h>
+#include <linux/usb/serial.h>
+#include <asm/uaccess.h>
+
+
+/*
+ * Version Information
+ */
+#define DRIVER_VERSION "1.0.0.4F"
+#define DRIVER_AUTHOR "Aspire Communications pvt Ltd."
+#define DRIVER_DESC "Moschip USB Serial Driver"
+
+/* default urb timeout */
+#define MOS_WDR_TIMEOUT	(HZ * 5)
+
+#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
+
+/* Interrupt Rotinue Defines	*/
+#define SERIAL_IIR_RLS	0x06
+#define SERIAL_IIR_RDA	0x04
+#define SERIAL_IIR_CTI	0x0c
+#define SERIAL_IIR_THR	0x02
+#define SERIAL_IIR_MS	0x00
+
+#define NUM_URBS			16	/* URB Count */
+#define URB_TRANSFER_BUFFER_SIZE	32	/* URB Size */
+
+/* This structure holds all of the local port information */
+struct moschip_port
+{
+	__u8	shadowLCR;		/* last LCR value received */
+	__u8	shadowMCR;		/* last MCR value received */
+	__u8	shadowMSR;		/* last MSR value received */
+	char			open;
+	struct async_icount	icount;
+	struct usb_serial_port	*port;	/* loop back to the owner */
+	struct urb		*write_urb_pool[NUM_URBS];
+};
+
+/* This structure holds all of the individual serial device information */
+struct moschip_serial
+{
+	int interrupt_started;
+};
+
+static int debug;
+
+#define USB_VENDOR_ID_MOSCHIP		0x9710
+#define MOSCHIP_DEVICE_ID_7720		0x7720
+#define MOSCHIP_DEVICE_ID_7715		0x7715
+
+static struct usb_device_id moschip_port_id_table [] = {
+	{ USB_DEVICE(USB_VENDOR_ID_MOSCHIP,MOSCHIP_DEVICE_ID_7720) },
+	{ } /* terminating entry */
+};
+MODULE_DEVICE_TABLE(usb, moschip_port_id_table);
+
+
+/*
+ * mos7720_interrupt_callback
+ *	this is the callback function for when we have received data on the
+ *	interrupt endpoint.
+ */
+static void mos7720_interrupt_callback(struct urb *urb)
+{
+	int result;
+	int length;
+	__u32 *data;
+	unsigned int status;
+	__u8 sp1;
+	__u8 sp2;
+	__u8 st;
+
+	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;
+
+	/* Moschip get 4 bytes
+	 * Byte 1 IIR Port 1 (port.number is 0)
+	 * Byte 2 IIR Port 2 (port.number is 1)
+	 * Byte 3 --------------
+	 * Byte 4 FIFO status for both */
+	if (length && length > 4) {
+		dbg("Wrong data !!!");
+		return;
+	}
+
+	status = *data;
+
+	sp1 = (status & 0xff000000)>>24;
+	sp2 = (status & 0x00ff0000)>>16;
+	st = status & 0x000000ff;
+
+	if ((sp1 & 0x01) || (sp2 & 0x01)) {
+		/* No Interrupt Pending in both the ports */
+		dbg("No Interrupt !!!");
+	} else {
+		switch (sp1 & 0x0f) {
+		case SERIAL_IIR_RLS:
+			dbg("Serial Port 1: Receiver status error or address "
+			    "bit detected in 9-bit mode\n");
+			break;
+		case SERIAL_IIR_CTI:
+			dbg("Serial Port 1: Receiver time out");
+			break;
+		case SERIAL_IIR_MS:
+			dbg("Serial Port 1: Modem status change");
+			break;
+		}
+
+		switch (sp2 & 0x0f) {
+		case SERIAL_IIR_RLS:
+			dbg("Serial Port 2: Receiver status error or address "
+			    "bit detected in 9-bit mode");
+			break;
+		case SERIAL_IIR_CTI:
+			dbg("Serial Port 2: Receiver time out");
+			break;
+		case SERIAL_IIR_MS:
+			dbg("Serial Port 2: Modem status change");
+			break;
+		}
+	}
+
+exit:
+	result = usb_submit_urb(urb, GFP_ATOMIC);
+	if (result)
+		dev_err(&urb->dev->dev,
+			"%s - Error %d submitting control urb\n",
+			__FUNCTION__, result);
+	return;
+}
+
+/*
+ * mos7720_bulk_in_callback
+ *	this is the callback function for when we have received data on the
+ *	bulk in endpoint.
+ */
+static void mos7720_bulk_in_callback(struct urb *urb)
+{
+	int status;
+	unsigned char *data ;
+	struct usb_serial_port *port;
+	struct moschip_port *mos7720_port;
+	struct tty_struct *tty;
+
+	if (urb->status) {
+		dbg("nonzero read bulk status received: %d",urb->status);
+		return;
+	}
+
+	mos7720_port = urb->context;
+	if (!mos7720_port) {
+		dbg("%s","NULL mos7720_port pointer \n");
+		return ;
+	}
+
+	port = mos7720_port->port;
+
+	dbg("Entering...%s", __FUNCTION__);
+
+	data = urb->transfer_buffer;
+
+	tty = port->tty;
+	if (tty && urb->actual_length) {
+		tty_buffer_request_room(tty, urb->actual_length);
+		tty_insert_flip_string(tty, data, urb->actual_length);
+		tty_flip_buffer_push(tty);
+	}
+
+	if (!port->read_urb) {
+		dbg("URB KILLED !!!");
+		return;
+	}
+
+	if (port->read_urb->status != -EINPROGRESS) {
+		port->read_urb->dev = port->serial->dev;
+
+		status = usb_submit_urb(port->read_urb, GFP_ATOMIC);
+		if (status)
+			dbg("usb_submit_urb(read bulk) failed, status = %d",
+			    status);
+	}
+}
+
+/*
+ * mos7720_bulk_out_data_callback
+ *	this is the callback function for when we have finished sending serial
+ *	data on the bulk out endpoint.
+ */
+static void mos7720_bulk_out_data_callback(struct urb *urb)
+{
+	struct moschip_port *mos7720_port;
+	struct tty_struct *tty;
+
+	if (urb->status) {
+		dbg("nonzero write bulk status received:%d", urb->status);
+		return;
+	}
+
+	mos7720_port = urb->context;
+	if (!mos7720_port) {
+		dbg("NULL mos7720_port pointer");
+		return ;
+	}
+
+	dbg("Entering .........");
+
+	tty = mos7720_port->port->tty;
+
+	if (tty && mos7720_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);
+	}
+
+	/* schedule_work(&mos7720_port->port->work); */
+}
+
+/*
+ * send_mos_cmd
+ *	this function will be used for sending command to device
+ */
+static int send_mos_cmd(struct usb_serial *serial, __u8 request, __u16 value,
+			__u16 index, void *data)
+{
+	int status;
+	unsigned int pipe;
+	u16 product = le16_to_cpu(serial->dev->descriptor.idProduct);
+	__u8 requesttype;
+	__u16 size = 0x0000;
+
+	if (value < MOS_MAX_PORT) {
+		if (product == MOSCHIP_DEVICE_ID_7715) {
+			value = value*0x100+0x100;
+		} else {
+			value = value*0x100+0x200;
+		}
+	} else {
+		value = 0x0000;
+		if ((product == MOSCHIP_DEVICE_ID_7715) &&
+		    (index != 0x08)) {
+			dbg("serial->product== MOSCHIP_DEVICE_ID_7715");
+			//index = 0x01 ;
+		}
+	}
+
+	if (request == MOS_WRITE) {
+		request = (__u8)MOS_WRITE;
+		requesttype = (__u8)0x40;
+		value  = value + (__u16)*((unsigned char *)data);
+		data = NULL;
+		pipe = usb_sndctrlpipe(serial->dev, 0);
+	} else {
+		request = (__u8)MOS_READ;
+		requesttype = (__u8)0xC0;
+		size = 0x01;
+		pipe = usb_rcvctrlpipe(serial->dev,0);
+	}
+
+	status = usb_control_msg(serial->dev, pipe, request, requesttype,
+				 value, index, data, size, MOS_WDR_TIMEOUT);
+
+	if (status < 0)
+		dbg("Command Write failed Value %x index %x\n",value,index);
+
+	return status;
+}
+
+static int mos7720_open(struct usb_serial_port *port, struct file * filp)
+{
+	struct usb_serial *serial;
+	struct usb_serial_port *port0;
+	struct urb *urb;
+	struct moschip_serial *mos7720_serial;
+	struct moschip_port *mos7720_port;
+	int response;
+	int port_number;
+	char data;
+	int j;
+
+	serial = port->serial;
+
+	mos7720_port = usb_get_serial_port_data(port);
+	if (mos7720_port == NULL)
+		return -ENODEV;
+
+	port0 = serial->port[0];
+
+	mos7720_serial = usb_get_serial_data(serial);
+
+	if (mos7720_serial == NULL || port0 == 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);
+		mos7720_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) {
+			err("%s-out of memory for urb buffers.", __FUNCTION__);
+			continue;
+		}
+	}
+
+	 /* Initialize MCS7720 -- Write Init values to corresponding Registers
+	  *
+	  * Register Index
+	  * 1 : IER
+	  * 2 : FCR
+	  * 3 : LCR
+	  * 4 : MCR
+	  *
+	  * 0x08 : SP1/2 Control Reg
+	  */
+	port_number = port->number - port->serial->minor;
+	send_mos_cmd(port->serial, MOS_READ, port_number, UART_LSR, &data);
+	dbg("SS::%p LSR:%x\n",mos7720_port, data);
+
+	dbg("Check:Sending Command ..........");
+
+	data = 0x02;
+	send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT, 0x01, &data);
+	data = 0x02;
+	send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT, 0x02, &data);
+
+	data = 0x00;
+	send_mos_cmd(serial, MOS_WRITE, port_number, 0x01, &data);
+	data = 0x00;
+	send_mos_cmd(serial, MOS_WRITE, port_number, 0x02, &data);
+
+	data = 0xCF;
+	send_mos_cmd(serial, MOS_WRITE, port_number, 0x02, &data);
+	data = 0x03;
+        mos7720_port->shadowLCR  = data;
+	send_mos_cmd(serial, MOS_WRITE, port_number, 0x03, &data);
+	data = 0x0b;
+        mos7720_port->shadowMCR  = data;
+	send_mos_cmd(serial, MOS_WRITE, port_number, 0x04, &data);
+	data = 0x0b;
+	send_mos_cmd(serial, MOS_WRITE, port_number, 0x04, &data);
+
+	data = 0x00;
+	send_mos_cmd(serial, MOS_READ, MOS_MAX_PORT, 0x08, &data);
+	data = 0x00;
+	send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT, 0x08, &data);
+
+/*	data = 0x00;
+	send_mos_cmd(serial, MOS_READ, MOS_MAX_PORT, port_number + 1, &data);
+	data = 0x03;
+	send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT, port_number + 1, &data);
+	data = 0x00;
+	send_mos_cmd(port->serial, MOS_WRITE, MOS_MAX_PORT, port_number + 1, &data);
+*/
+	data = 0x00;
+	send_mos_cmd(serial, MOS_READ, MOS_MAX_PORT, 0x08, &data);
+
+	data = data | (port->number - port->serial->minor + 1);
+	send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT, 0x08, &data);
+
+	data = 0x83;
+        mos7720_port->shadowLCR  = data;
+	send_mos_cmd(serial, MOS_WRITE, port_number, 0x03, &data);
+	data = 0x0c;
+	send_mos_cmd(serial, MOS_WRITE, port_number, 0x00, &data);
+	data = 0x00;
+	send_mos_cmd(serial, MOS_WRITE, port_number, 0x01, &data);
+	data = 0x03;
+        mos7720_port->shadowLCR  = data;
+	send_mos_cmd(serial, MOS_WRITE, port_number, 0x03, &data);
+	data = 0x0c;
+	send_mos_cmd(serial, MOS_WRITE, port_number, 0x01, &data);
+	data = 0x0c;
+	send_mos_cmd(serial, MOS_WRITE, port_number, 0x01, &data);
+
+//Matrix
+
+	/* 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;
+
+	/* see if we've set up our endpoint info yet   *
+	 * (can't set it up in mos7720_startup as the  *
+	 * structures were not set up at that time.)   */
+	if (!mos7720_serial->interrupt_started) {
+		dbg("Interrupt buffer NULL !!!");
+
+		/* not set up yet, so do it now */
+		mos7720_serial->interrupt_started = 1;
+
+		dbg("To Submit URB !!!");
+
+		/* set up our interrupt urb */
+		usb_fill_int_urb(port0->interrupt_in_urb, serial->dev,
+				 usb_rcvintpipe(serial->dev,
+				 		port->interrupt_in_endpointAddress),
+				 port0->interrupt_in_buffer,
+				 port0->interrupt_in_urb->transfer_buffer_length,
+				 mos7720_interrupt_callback, mos7720_port,
+				 port0->interrupt_in_urb->interval);
+
+		/* start interrupt read for this mos7720 this interrupt *
+	         * will continue as long as the mos7720 is connected    */
+		dbg("Submit URB over !!!");
+		response = usb_submit_urb(port0->interrupt_in_urb, GFP_KERNEL);
+		if (response)
+			dev_err(&port->dev,
+				"%s - Error %d submitting control urb",
+				__FUNCTION__, response);
+	}
+
+	/* set up our bulk in urb */
+	usb_fill_bulk_urb(port->read_urb, serial->dev,
+			  usb_rcvbulkpipe(serial->dev,
+			  		  port->bulk_in_endpointAddress),
+			  port->bulk_in_buffer,
+			  port->read_urb->transfer_buffer_length,
+			  mos7720_bulk_in_callback, mos7720_port);
+	response = usb_submit_urb(port->read_urb, GFP_KERNEL);
+	if (response)
+		dev_err(&port->dev,
+			"%s - Error %d submitting read urb", __FUNCTION__, response);
+
+	/* initialize our icount structure */
+	memset(&(mos7720_port->icount), 0x00, sizeof(mos7720_port->icount));
+
+	/* initialize our port settings */
+	mos7720_port->shadowMCR = UART_MCR_OUT2; /* Must set to enable ints! */
+
+	/* send a open port command */
+	mos7720_port->open = 1;
+
+	return 0;
+}
+
+/*
+ * mos7720_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 mos7720_chars_in_buffer(struct usb_serial_port *port)
+{
+	int i;
+	int chars = 0;
+	struct moschip_port *mos7720_port;
+
+	dbg("%s:entering ...........", __FUNCTION__);
+
+	mos7720_port = usb_get_serial_port_data(port);
+	if (mos7720_port == NULL) {
+		dbg("%s:leaving ...........", __FUNCTION__);
+		return -ENODEV;
+	}
+
+	for (i = 0; i < NUM_URBS; ++i) {
+		if (mos7720_port->write_urb_pool[i]->status == -EINPROGRESS)
+			chars += URB_TRANSFER_BUFFER_SIZE;
+	}
+	dbg("%s - returns %d", __FUNCTION__, chars);
+	return chars;
+}
+
+static void mos7720_close(struct usb_serial_port *port, struct file *filp)
+{
+	struct usb_serial *serial;
+	struct moschip_port *mos7720_port;
+	char data;
+	int j;
+
+	dbg("mos7720_close:entering...");
+
+	serial = port->serial;
+
+	mos7720_port = usb_get_serial_port_data(port);
+	if (mos7720_port == NULL)
+		return;
+
+	for (j = 0; j < NUM_URBS; ++j)
+		usb_kill_urb(mos7720_port->write_urb_pool[j]);
+
+	/* Freeing Write URBs */
+	for (j = 0; j < NUM_URBS; ++j) {
+		if (mos7720_port->write_urb_pool[j]) {
+			kfree(mos7720_port->write_urb_pool[j]->transfer_buffer);
+			usb_free_urb(mos7720_port->write_urb_pool[j]);
+		}
+	}
+
+	/* While closing port, shutdown all bulk read, write  *
+	 * and interrupt read if they exists                  */
+	if (serial->dev) {
+		dbg("Shutdown bulk write");
+		usb_kill_urb(port->write_urb);
+		dbg("Shutdown bulk read");
+		usb_kill_urb(port->read_urb);
+	}
+
+	data = 0x00;
+	send_mos_cmd(serial, MOS_WRITE, port->number - port->serial->minor,
+		     0x04, &data);
+
+	data = 0x00;
+	send_mos_cmd(serial, MOS_WRITE, port->number - port->serial->minor,
+		     0x01, &data);
+
+	mos7720_port->open = 0;
+
+	dbg("Leaving %s", __FUNCTION__);
+}
+
+static void mos7720_break(struct usb_serial_port *port, int break_state)
+{
+        unsigned char data;
+	struct usb_serial *serial;
+	struct moschip_port *mos7720_port;
+
+	dbg("Entering %s", __FUNCTION__);
+
+	serial = port->serial;
+
+	mos7720_port = usb_get_serial_port_data(port);
+	if (mos7720_port == NULL)
+		return;
+
+	if (break_state == -1)
+		data = mos7720_port->shadowLCR | UART_LCR_SBC;
+	else
+		data = mos7720_port->shadowLCR & ~UART_LCR_SBC;
+
+	mos7720_port->shadowLCR  = data;
+	send_mos_cmd(serial, MOS_WRITE, port->number - port->serial->minor,
+		     0x03, &data);
+
+	return;
+}
+
+/*
+ * mos7720_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 mos7720_write_room(struct usb_serial_port *port)
+{
+	struct moschip_port *mos7720_port;
+	int room = 0;
+	int i;
+
+	dbg("%s:entering ...........", __FUNCTION__);
+
+	mos7720_port = usb_get_serial_port_data(port);
+	if (mos7720_port == NULL) {
+		dbg("%s:leaving ...........", __FUNCTION__);
+		return -ENODEV;
+	}
+
+	for (i = 0; i < NUM_URBS; ++i) {
+		if (mos7720_port->write_urb_pool[i]->status != -EINPROGRESS)
+			room += URB_TRANSFER_BUFFER_SIZE;
+	}
+
+	dbg("%s - returns %d", __FUNCTION__, room);
+	return room;
+}
+
+static int mos7720_write(struct usb_serial_port *port,
+			 const unsigned char *data, int count)
+{
+	int status;
+	int i;
+	int bytes_sent = 0;
+	int transfer_size;
+
+	struct moschip_port *mos7720_port;
+	struct usb_serial *serial;
+	struct urb    *urb;
+	const unsigned char *current_position = data;
+
+	dbg("%s:entering ...........", __FUNCTION__);
+
+	serial = port->serial;
+
+	mos7720_port = usb_get_serial_port_data(port);
+	if (mos7720_port == NULL) {
+		dbg("mos7720_port is NULL");
+		return -ENODEV;
+	}
+
+	/* try to find a free urb in the list */
+	urb = NULL;
+
+	for (i = 0; i < NUM_URBS; ++i) {
+		if (mos7720_port->write_urb_pool[i]->status != -EINPROGRESS) {
+			urb = mos7720_port->write_urb_pool[i];
+			dbg("URB:%d",i);
+			break;
+		}
+	}
+
+	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);
+	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, transfer_size,
+			      urb->transfer_buffer);
+
+	/* 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,
+			  mos7720_bulk_out_data_callback, mos7720_port);
+
+	/* send it down the pipe */
+	status = usb_submit_urb(urb,GFP_ATOMIC);
+	if (status) {
+		err("%s - usb_submit_urb(write bulk) failed with status = %d",
+		    __FUNCTION__, status);
+		bytes_sent = status;
+		goto exit;
+	}
+	bytes_sent = transfer_size;
+
+exit:
+	return bytes_sent;
+}
+
+static void mos7720_throttle(struct usb_serial_port *port)
+{
+	struct moschip_port *mos7720_port;
+	struct tty_struct *tty;
+	int status;
+
+	dbg("%s- port %d\n", __FUNCTION__, port->number);
+
+	mos7720_port = usb_get_serial_port_data(port);
+
+	if (mos7720_port == NULL)
+		return;
+
+	if (!mos7720_port->open) {
+		dbg("port not opened");
+		return;
+	}
+
+	dbg("%s: Entering ..........", __FUNCTION__);
+
+	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 = mos7720_write(port, &stop_char, 1);
+		if (status <= 0)
+			return;
+	}
+
+	/* if we are implementing RTS/CTS, toggle that line */
+	if (tty->termios->c_cflag & CRTSCTS) {
+		mos7720_port->shadowMCR &= ~UART_MCR_RTS;
+		status = send_mos_cmd(port->serial, MOS_WRITE,
+				      port->number - port->serial->minor,
+				      UART_MCR, &mos7720_port->shadowMCR);
+		if (status != 0)
+			return;
+	}
+}
+
+static void mos7720_unthrottle(struct usb_serial_port *port)
+{
+	struct tty_struct *tty;
+	int status;
+	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
+
+	if (mos7720_port == NULL)
+		return;
+
+	if (!mos7720_port->open) {
+		dbg("%s - port not opened", __FUNCTION__);
+		return;
+	}
+
+	dbg("%s: Entering ..........", __FUNCTION__);
+
+	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 = mos7720_write(port, &start_char, 1);
+		if (status <= 0)
+			return;
+	}
+
+	/* if we are implementing RTS/CTS, toggle that line */
+	if (tty->termios->c_cflag & CRTSCTS) {
+		mos7720_port->shadowMCR |= UART_MCR_RTS;
+		status = send_mos_cmd(port->serial, MOS_WRITE,
+				      port->number - port->serial->minor,
+				      UART_MCR, &mos7720_port->shadowMCR);
+		if (status != 0)
+			return;
+	}
+}
+
+static int set_higher_rates(struct moschip_port *mos7720_port,
+			    unsigned int baud)
+{
+	unsigned char data;
+	struct usb_serial_port *port;
+	struct usb_serial *serial;
+	int port_number;
+
+	if (mos7720_port == NULL)
+		return -EINVAL;
+
+	port = mos7720_port->port;
+	serial = port->serial;
+
+        /***********************************************
+         *      Init Sequence for higher rates
+         ***********************************************/
+	dbg("Sending Setting Commands ..........");
+	port_number = port->number - port->serial->minor;
+
+	data = 0x000;
+	send_mos_cmd(serial, MOS_WRITE, port_number, 0x01, &data);
+	data = 0x000;
+	send_mos_cmd(serial, MOS_WRITE, port_number, 0x02, &data);
+	data = 0x0CF;
+	send_mos_cmd(serial, MOS_WRITE, port->number, 0x02, &data);
+	data = 0x00b;
+        mos7720_port->shadowMCR  = data;
+	send_mos_cmd(serial, MOS_WRITE, port_number, 0x04, &data);
+	data = 0x00b;
+	send_mos_cmd(serial, MOS_WRITE, port_number, 0x04, &data);
+
+	data = 0x000;
+	send_mos_cmd(serial, MOS_READ, MOS_MAX_PORT, 0x08, &data);
+	data = 0x000;
+	send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT, 0x08, &data);
+
+
+        /***********************************************
+         *              Set for higher rates           *
+         ***********************************************/
+
+	data = baud * 0x10;
+	send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT, port_number + 1,&data);
+
+	data = 0x003;
+	send_mos_cmd(serial, MOS_READ, MOS_MAX_PORT, 0x08, &data);
+	data = 0x003;
+	send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT, 0x08, &data);
+
+	data = 0x02b;
+        mos7720_port->shadowMCR  = data;
+	send_mos_cmd(serial, MOS_WRITE, port_number, 0x04, &data);
+	data = 0x02b;
+	send_mos_cmd(serial, MOS_WRITE, port_number, 0x04, &data);
+
+        /***********************************************
+         *              Set DLL/DLM
+         ***********************************************/
+
+	data = mos7720_port->shadowLCR | UART_LCR_DLAB;
+        mos7720_port->shadowLCR  = data;
+	send_mos_cmd(serial, MOS_WRITE, port_number, 0x03, &data);
+
+	data =  0x001; /* DLL */
+        send_mos_cmd(serial, MOS_WRITE, port_number, 0x00, &data);
+	data =  0x000; /* DLM */
+        send_mos_cmd(serial, MOS_WRITE, port_number, 0x01, &data);
+
+	data = mos7720_port->shadowLCR & ~UART_LCR_DLAB;
+        mos7720_port->shadowLCR  = data;
+	send_mos_cmd(serial, MOS_WRITE, port_number, 0x03, &data);
+
+	return 0;
+}
+
+/* baud rate information */
+struct divisor_table_entry
+{
+	__u32  baudrate;
+	__u16  divisor;
+};
+
+/* Define table of divisors for moschip 7720 hardware	   *
+ * These assume a 3.6864MHz crystal, the standard /16, and *
+ * MCR.7 = 0.						   */
+static struct divisor_table_entry divisor_table[] = {
+	{   50,		2304},
+	{   110,	1047},	/* 2094.545455 => 230450   => .0217 % over */
+	{   134,	857},	/* 1713.011152 => 230398.5 => .00065% under */
+	{   150,	768},
+	{   300,	384},
+	{   600,	192},
+	{   1200,	96},
+	{   1800,	64},
+	{   2400,	48},
+	{   4800,	24},
+	{   7200,	16},
+	{   9600,	12},
+	{   19200,	6},
+	{   38400,	3},
+	{   57600,	2},
+	{   115200,	1},
+};
+
+/*****************************************************************************
+ * calc_baud_rate_divisor
+ *	this function calculates the proper baud rate divisor for the specified
+ *	baud rate.
+ *****************************************************************************/
+static int calc_baud_rate_divisor(int baudrate, int *divisor)
+{
+	int i;
+	__u16 custom;
+	__u16 round1;
+	__u16 round;
+
+
+	dbg("%s - %d", __FUNCTION__, baudrate);
+
+	for (i = 0; i < ARRAY_SIZE(divisor_table); i++) {
+		if (divisor_table[i].baudrate == baudrate) {
+			*divisor = 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",baudrate, custom);
+		return 0;
+	}
+
+	dbg("Baud calculation Failed...");
+	return -EINVAL;
+}
+
+/*
+ * send_cmd_write_baud_rate
+ *	this function sends the proper command to change the baud rate of the
+ *	specified port.
+ */
+static int send_cmd_write_baud_rate(struct moschip_port *mos7720_port,
+				    int baudrate)
+{
+	struct usb_serial_port *port;
+	struct usb_serial *serial;
+	int divisor;
+	int status;
+	unsigned char data;
+	unsigned char number;
+
+	if (mos7720_port == NULL)
+		return -1;
+
+	port = mos7720_port->port;
+	serial = port->serial;
+
+	dbg("%s: Entering ..........", __FUNCTION__);
+
+	number = port->number - port->serial->minor;
+	dbg("%s - port = %d, baud = %d", __FUNCTION__, port->number, baudrate);
+
+        /* Calculate the Divisor */
+	status = calc_baud_rate_divisor(baudrate, &divisor);
+	if (status) {
+		err("%s - bad baud rate", __FUNCTION__);
+		return status;
+	}
+
+        /* Enable access to divisor latch */
+        data = mos7720_port->shadowLCR | UART_LCR_DLAB;
+        mos7720_port->shadowLCR  = data;
+        send_mos_cmd(serial, MOS_WRITE, number, UART_LCR, &data);
+
+	/* Write the divisor */
+	data = ((unsigned char)(divisor & 0xff));
+        send_mos_cmd(serial, MOS_WRITE, number, 0x00, &data);
+
+	data = ((unsigned char)((divisor & 0xff00) >> 8));
+        send_mos_cmd(serial, MOS_WRITE, number, 0x01, &data);
+
+        /* Disable access to divisor latch */
+        data = mos7720_port->shadowLCR & ~UART_LCR_DLAB;
+        mos7720_port->shadowLCR = data;
+        send_mos_cmd(serial, MOS_WRITE, number, 0x03, &data);
+
+	return status;
+}
+
+/*
+ * change_port_settings
+ *	This routine is called to set the UART on the device to match
+ *      the specified new settings.
+ */
+static void change_port_settings(struct moschip_port *mos7720_port,
+				 struct termios *old_termios)
+{
+	struct usb_serial_port *port;
+	struct usb_serial *serial;
+	struct tty_struct *tty;
+	int baud;
+	unsigned cflag;
+	unsigned iflag;
+	__u8 mask = 0xff;
+	__u8 lData;
+	__u8 lParity;
+	__u8 lStop;
+	int status;
+	int port_number;
+	char data;
+
+	if (mos7720_port == NULL)
+		return ;
+
+	port = mos7720_port->port;
+	serial = port->serial;
+	port_number = port->number - port->serial->minor;
+
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	if (!mos7720_port->open) {
+		dbg("%s - port not opened", __FUNCTION__);
+		return;
+	}
+
+	tty = mos7720_port->port->tty;
+
+	if ((!tty) || (!tty->termios)) {
+		dbg("%s - no tty structures", __FUNCTION__);
+		return;
+	}
+
+	dbg("%s: Entering ..........", __FUNCTION__);
+
+	lData = UART_LCR_WLEN8;
+	lStop = 0x00;	/* 1 stop bit */
+	lParity = 0x00;	/* No parity */
+
+	cflag = tty->termios->c_cflag;
+	iflag = tty->termios->c_iflag;
+
+	/* Change the number of bits */
+	switch (cflag & CSIZE) {
+	case CS5:
+		lData = UART_LCR_WLEN5;
+		mask = 0x1f;
+		break;
+
+	case CS6:
+		lData = UART_LCR_WLEN6;
+		mask = 0x3f;
+		break;
+
+	case CS7:
+		lData = UART_LCR_WLEN7;
+		mask = 0x7f;
+		break;
+	default:
+	case CS8:
+		lData = UART_LCR_WLEN8;
+		break;
+	}
+
+	/* Change the Parity bit */
+	if (cflag & PARENB) {
+		if (cflag & PARODD) {
+			lParity = UART_LCR_PARITY;
+			dbg("%s - parity = odd", __FUNCTION__);
+		} else {
+			lParity = (UART_LCR_EPAR | UART_LCR_PARITY);
+			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 = UART_LCR_STOP;
+		dbg("%s - stop bits = 2", __FUNCTION__);
+	} else {
+		lStop = 0x00;
+		dbg("%s - stop bits = 1", __FUNCTION__);
+	}
+
+#define LCR_BITS_MASK		0x03	/* Mask for bits/char field */
+#define LCR_STOP_MASK		0x04	/* Mask for stop bits field */
+#define LCR_PAR_MASK		0x38	/* Mask for parity field */
+
+	/* Update the LCR with the correct value */
+	mos7720_port->shadowLCR &= ~(LCR_BITS_MASK | LCR_STOP_MASK | LCR_PAR_MASK);
+	mos7720_port->shadowLCR |= (lData | lParity | lStop);
+
+
+	/* Disable Interrupts */
+	data = 0x00;
+        send_mos_cmd(serial,MOS_WRITE,port->number - port->serial->minor, UART_IER, &data);
+
+	data = 0x00;
+        send_mos_cmd(serial, MOS_WRITE, port_number, UART_FCR, &data);
+
+	data = 0xcf;
+        send_mos_cmd(serial, MOS_WRITE, port_number, UART_FCR, &data);
+
+	/* Send the updated LCR value to the mos7720 */
+	data = mos7720_port->shadowLCR;
+        send_mos_cmd(serial, MOS_WRITE, port_number, UART_LCR, &data);
+
+        data = 0x00b;
+        mos7720_port->shadowMCR = data;
+        send_mos_cmd(serial, MOS_WRITE, port_number, 0x04, &data);
+        data = 0x00b;
+        send_mos_cmd(serial, MOS_WRITE, port_number, 0x04, &data);
+
+	/* set up the MCR register and send it to the mos7720 */
+	mos7720_port->shadowMCR = UART_MCR_OUT2;
+	if (cflag & CBAUD)
+		mos7720_port->shadowMCR |= (UART_MCR_DTR | UART_MCR_RTS);
+
+	if (cflag & CRTSCTS) {
+		mos7720_port->shadowMCR |= (UART_MCR_XONANY);
+
+                /* To set hardware flow control to the specified *
+                 * serial port, in SP1/2_CONTROL_REG             */
+		if (port->number) {
+			data = 0x001;
+			send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT,
+				     0x08, &data);
+		} else {
+			data = 0x002;
+			send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT,
+				     0x08, &data);
+		}
+	} else {
+		mos7720_port->shadowMCR &= ~(UART_MCR_XONANY);
+	}
+
+	data = mos7720_port->shadowMCR;
+	send_mos_cmd(serial, MOS_WRITE, port_number, UART_MCR, &data);
+
+	/* Determine divisor based on baud rate */
+	baud = tty_get_baud_rate(tty);
+	if (!baud) {
+		/* pick a default, any default... */
+		dbg("Picked default baud...");
+		baud = 9600;
+	}
+
+	if (baud >= 230400) {
+		set_higher_rates(mos7720_port, baud);
+		/* Enable Interrupts */
+		data = 0x0c;
+		send_mos_cmd(serial, MOS_WRITE, port_number, UART_IER, &data);
+		return;
+	}
+
+	dbg("%s - baud rate = %d", __FUNCTION__, baud);
+	status = send_cmd_write_baud_rate(mos7720_port, baud);
+
+	/* Enable Interrupts */
+	data = 0x0c;
+	send_mos_cmd(serial, MOS_WRITE, port_number, UART_IER, &data);
+
+	if (port->read_urb->status != -EINPROGRESS) {
+		port->read_urb->dev = serial->dev;
+
+		status = usb_submit_urb(port->read_urb, GFP_ATOMIC);
+		if (status)
+			dbg("usb_submit_urb(read bulk) failed, status = %d",
+			    status);
+	}
+	return;
+}
+
+/*
+ * mos7720_set_termios
+ *	this function is called by the tty driver when it wants to change the
+ *	termios structure.
+ */
+static void mos7720_set_termios(struct usb_serial_port *port,
+				struct termios *old_termios)
+{
+	int status;
+	unsigned int cflag;
+	struct usb_serial *serial;
+	struct moschip_port *mos7720_port;
+	struct tty_struct *tty;
+
+	serial = port->serial;
+
+	mos7720_port = usb_get_serial_port_data(port);
+
+	if (mos7720_port == NULL)
+		return;
+
+	tty = port->tty;
+
+	if (!port->tty || !port->tty->termios) {
+		dbg("%s - no tty or termios", __FUNCTION__);
+		return;
+	}
+
+	if (!mos7720_port->open) {
+		dbg("%s - port not opened", __FUNCTION__);
+		return;
+	}
+
+	dbg("%s\n","setting termios - ASPIRE");
+
+	cflag = tty->termios->c_cflag;
+
+	if (!cflag) {
+		printk("%s %s\n",__FUNCTION__,"cflag is NULL");
+		return;
+	}
+
+	/* check that they really want us to change something */
+	if (old_termios) {
+		if ((cflag == old_termios->c_cflag) &&
+		    (RELEVANT_IFLAG(tty->termios->c_iflag) ==
+		     RELEVANT_IFLAG(old_termios->c_iflag))) {
+			dbg("Nothing to change");
+			return;
+		}
+	}
+
+	dbg("%s - clfag %08x iflag %08x", __FUNCTION__,
+	    tty->termios->c_cflag,
+	    RELEVANT_IFLAG(tty->termios->c_iflag));
+
+	if (old_termios)
+		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 */
+	change_port_settings(mos7720_port, old_termios);
+
+	if(!port->read_urb) {
+		dbg("%s","URB KILLED !!!!!\n");
+		return;
+	}
+
+	if(port->read_urb->status != -EINPROGRESS) {
+		port->read_urb->dev = serial->dev;
+		status = usb_submit_urb(port->read_urb, GFP_ATOMIC);
+		if (status)
+			dbg("usb_submit_urb(read bulk) failed, status = %d",
+			    status);
+	}
+	return;
+}
+
+/*
+ * 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 get_lsr_info(struct moschip_port *mos7720_port,
+			unsigned int __user *value)
+{
+	int count;
+	unsigned int result = 0;
+
+	count = mos7720_chars_in_buffer(mos7720_port->port);
+	if (count == 0) {
+		dbg("%s -- Empty", __FUNCTION__);
+		result = TIOCSER_TEMT;
+	}
+
+	if (copy_to_user(value, &result, sizeof(int)))
+		return -EFAULT;
+	return 0;
+}
+
+/*
+ * get_number_bytes_avail - get number of bytes available
+ *
+ * Purpose: Let user call ioctl to get the count of number of bytes available.
+ */
+static int get_number_bytes_avail(struct moschip_port *mos7720_port,
+				  unsigned int __user *value)
+{
+	unsigned int result = 0;
+	struct tty_struct *tty = mos7720_port->port->tty;
+
+	if (!tty)
+		return -ENOIOCTLCMD;
+
+	result = tty->read_cnt;
+
+	dbg("%s(%d) = %d", __FUNCTION__,  mos7720_port->port->number, result);
+	if (copy_to_user(value, &result, sizeof(int)))
+		return -EFAULT;
+
+	return -ENOIOCTLCMD;
+}
+
+static int set_modem_info(struct moschip_port *mos7720_port, unsigned int cmd,
+			  unsigned int __user *value)
+{
+	unsigned int mcr ;
+	unsigned int arg;
+	unsigned char data;
+
+	struct usb_serial_port *port;
+
+	if (mos7720_port == NULL)
+		return -1;
+
+	port = (struct usb_serial_port*)mos7720_port->port;
+	mcr = mos7720_port->shadowMCR;
+
+	if (copy_from_user(&arg, value, sizeof(int)))
+		return -EFAULT;
+
+	switch (cmd) {
+	case TIOCMBIS:
+		if (arg & TIOCM_RTS)
+			mcr |= UART_MCR_RTS;
+		if (arg & TIOCM_DTR)
+			mcr |= UART_MCR_RTS;
+		if (arg & TIOCM_LOOP)
+			mcr |= UART_MCR_LOOP;
+		break;
+
+	case TIOCMBIC:
+		if (arg & TIOCM_RTS)
+			mcr &= ~UART_MCR_RTS;
+		if (arg & TIOCM_DTR)
+			mcr &= ~UART_MCR_RTS;
+		if (arg & TIOCM_LOOP)
+			mcr &= ~UART_MCR_LOOP;
+		break;
+
+	case TIOCMSET:
+		/* turn off the RTS and DTR and LOOPBACK
+		 * and then only turn on what was asked to */
+		mcr &=  ~(UART_MCR_RTS | UART_MCR_DTR | UART_MCR_LOOP);
+		mcr |= ((arg & TIOCM_RTS) ? UART_MCR_RTS : 0);
+		mcr |= ((arg & TIOCM_DTR) ? UART_MCR_DTR : 0);
+		mcr |= ((arg & TIOCM_LOOP) ? UART_MCR_LOOP : 0);
+		break;
+	}
+
+	mos7720_port->shadowMCR = mcr;
+
+	data = mos7720_port->shadowMCR;
+	send_mos_cmd(port->serial, MOS_WRITE,
+		     port->number - port->serial->minor, UART_MCR, &data);
+
+	return 0;
+}
+
+static int get_modem_info(struct moschip_port *mos7720_port,
+			  unsigned int __user *value)
+{
+	unsigned int result = 0;
+	unsigned int msr = mos7720_port->shadowMSR;
+	unsigned int mcr = mos7720_port->shadowMCR;
+
+	result = ((mcr & UART_MCR_DTR)	? TIOCM_DTR: 0)	  /* 0x002 */
+		  | ((mcr & UART_MCR_RTS)	? TIOCM_RTS: 0)   /* 0x004 */
+		  | ((msr & UART_MSR_CTS)	? TIOCM_CTS: 0)   /* 0x020 */
+		  | ((msr & UART_MSR_DCD)	? TIOCM_CAR: 0)   /* 0x040 */
+		  | ((msr & UART_MSR_RI)	? TIOCM_RI:  0)   /* 0x080 */
+		  | ((msr & UART_MSR_DSR)	? TIOCM_DSR: 0);  /* 0x100 */
+
+
+	dbg("%s -- %x", __FUNCTION__, result);
+
+	if (copy_to_user(value, &result, sizeof(int)))
+		return -EFAULT;
+	return 0;
+}
+
+static int get_serial_info(struct moschip_port *mos7720_port,
+			   struct serial_struct __user *retinfo)
+{
+	struct serial_struct tmp;
+
+	if (!retinfo)
+		return -EFAULT;
+
+	memset(&tmp, 0, sizeof(tmp));
+
+	tmp.type		= PORT_16550A;
+	tmp.line		= mos7720_port->port->serial->minor;
+	tmp.port		= mos7720_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;
+}
+
+static int mos7720_ioctl(struct usb_serial_port *port, struct file *file,
+			 unsigned int cmd, unsigned long arg)
+{
+	struct moschip_port *mos7720_port;
+	struct async_icount cnow;
+	struct async_icount cprev;
+	struct serial_icounter_struct icount;
+
+	mos7720_port = usb_get_serial_port_data(port);
+	if (mos7720_port == NULL)
+		return -ENODEV;
+
+	dbg("%s - port %d, cmd = 0x%x", __FUNCTION__, port->number, cmd);
+
+	switch (cmd) {
+	case TIOCINQ:
+		/* return number of bytes available */
+		dbg("%s (%d) TIOCINQ", __FUNCTION__,  port->number);
+		return get_number_bytes_avail(mos7720_port,
+					      (unsigned int __user *)arg);
+		break;
+
+	case TIOCSERGETLSR:
+		dbg("%s (%d) TIOCSERGETLSR", __FUNCTION__,  port->number);
+		return get_lsr_info(mos7720_port, (unsigned int __user *)arg);
+		return 0;
+
+	case TIOCMBIS:
+	case TIOCMBIC:
+	case TIOCMSET:
+		dbg("%s (%d) TIOCMSET/TIOCMBIC/TIOCMSET", __FUNCTION__,
+		    port->number);
+		return set_modem_info(mos7720_port, cmd,
+				      (unsigned int __user *)arg);
+
+	case TIOCMGET:
+		dbg("%s (%d) TIOCMGET", __FUNCTION__,  port->number);
+		return get_modem_info(mos7720_port,
+				      (unsigned int __user *)arg);
+
+	case TIOCGSERIAL:
+		dbg("%s (%d) TIOCGSERIAL", __FUNCTION__,  port->number);
+		return get_serial_info(mos7720_port,
+				       (struct serial_struct __user *)arg);
+
+	case TIOCSSERIAL:
+		dbg("%s (%d) TIOCSSERIAL", __FUNCTION__,  port->number);
+		break;
+
+	case TIOCMIWAIT:
+		dbg("%s (%d) TIOCMIWAIT", __FUNCTION__,  port->number);
+		cprev = mos7720_port->icount;
+		while (1) {
+			if (signal_pending(current))
+				return -ERESTARTSYS;
+			cnow = mos7720_port->icount;
+			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 = mos7720_port->icount;
+		icount.cts = cnow.cts;
+		icount.dsr = cnow.dsr;
+		icount.rng = cnow.rng;
+		icount.dcd = cnow.dcd;
+		icount.rx = cnow.rx;
+		icount.tx = cnow.tx;
+		icount.frame = cnow.frame;
+		icount.overrun = cnow.overrun;
+		icount.parity = cnow.parity;
+		icount.brk = cnow.brk;
+		icount.buf_overrun = cnow.buf_overrun;
+
+		dbg("%s (%d) TIOCGICOUNT RX=%d, TX=%d", __FUNCTION__,
+		    port->number, icount.rx, icount.tx );
+		if (copy_to_user((void __user *)arg, &icount, sizeof(icount)))
+			return -EFAULT;
+		return 0;
+	}
+
+	return -ENOIOCTLCMD;
+}
+
+static int mos7720_startup(struct usb_serial *serial)
+{
+	struct moschip_serial *mos7720_serial;
+	struct moschip_port *mos7720_port;
+	struct usb_device *dev;
+	int i;
+	char data;
+
+	dbg("%s: Entering ..........", __FUNCTION__);
+
+	if (!serial) {
+		dbg("Invalid Handler");
+		return -ENODEV;
+	}
+
+	dev = serial->dev;
+
+	/* create our private serial structure */
+	mos7720_serial = kzalloc(sizeof(struct moschip_serial), GFP_KERNEL);
+	if (mos7720_serial == NULL) {
+		err("%s - Out of memory", __FUNCTION__);
+		return -ENOMEM;
+	}
+
+	usb_set_serial_data(serial, mos7720_serial);
+
+	/* we set up the pointers to the endpoints in the mos7720_open *
+	 * function, as the structures aren't created yet.             */
+
+	/* set up port private structures */
+	for (i = 0; i < serial->num_ports; ++i) {
+		mos7720_port = kzalloc(sizeof(struct moschip_port), GFP_KERNEL);
+		if (mos7720_port == NULL) {
+			err("%s - Out of memory", __FUNCTION__);
+			usb_set_serial_data(serial, NULL);
+			kfree(mos7720_serial);
+			return -ENOMEM;
+		}
+
+		/* Initialize all port interrupt end point to port 0 int
+		 * endpoint.  Our device has only one interrupt endpoint
+		 * comman to all ports */
+		serial->port[i]->interrupt_in_endpointAddress = serial->port[0]->interrupt_in_endpointAddress;
+
+		mos7720_port->port = serial->port[i];
+		usb_set_serial_port_data(serial->port[i], mos7720_port);
+
+		dbg("port number is %d", serial->port[i]->number);
+		dbg("serial number is %d", serial->minor);
+	}
+
+
+	/* setting configuration feature to one */
+	usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+			(__u8)0x03, 0x00,0x01,0x00, NULL, 0x00, 5*HZ);
+
+	send_mos_cmd(serial,MOS_READ,0x00, UART_LSR, &data);  // LSR For Port 1
+	dbg("LSR:%x",data);
+
+	send_mos_cmd(serial,MOS_READ,0x01, UART_LSR, &data);  // LSR For Port 2
+	dbg("LSR:%x",data);
+
+	return 0;
+}
+
+static void mos7720_shutdown(struct usb_serial *serial)
+{
+	int i;
+
+	/* free private structure allocated for serial port */
+	for (i=0; i < serial->num_ports; ++i) {
+		kfree(usb_get_serial_port_data(serial->port[i]));
+		usb_set_serial_port_data(serial->port[i], NULL);
+	}
+
+	/* free private structure allocated for serial device */
+	kfree(usb_get_serial_data(serial));
+	usb_set_serial_data(serial, NULL);
+}
+
+static struct usb_serial_driver moschip7720_2port_driver = {
+	.driver = {
+		.owner =	THIS_MODULE,
+		.name =		"moschip7720",
+	},
+	.description		= "Moschip 2 port adapter",
+	.id_table		= moschip_port_id_table,
+	.num_interrupt_in	= 1,
+	.num_bulk_in		= 2,
+	.num_bulk_out		= 2,
+	.num_ports		= 2,
+	.open			= mos7720_open,
+	.close			= mos7720_close,
+	.throttle		= mos7720_throttle,
+	.unthrottle		= mos7720_unthrottle,
+	.attach			= mos7720_startup,
+	.shutdown		= mos7720_shutdown,
+	.ioctl			= mos7720_ioctl,
+	.set_termios		= mos7720_set_termios,
+	.write			= mos7720_write,
+	.write_room		= mos7720_write_room,
+	.chars_in_buffer	= mos7720_chars_in_buffer,
+	.break_ctl		= mos7720_break,
+	.read_bulk_callback	= mos7720_bulk_in_callback,
+};
+
+static struct usb_driver usb_driver = {
+	.name =		"moschip7720",
+	.probe =	usb_serial_probe,
+	.disconnect =	usb_serial_disconnect,
+	.id_table =	moschip_port_id_table,
+};
+
+static int __init moschip7720_init(void)
+{
+	int retval;
+
+	dbg("%s: Entering ..........", __FUNCTION__);
+
+	/* Register with the usb serial */
+	retval = usb_serial_register(&moschip7720_2port_driver);
+	if (retval)
+		goto failed_port_device_register;
+
+	info(DRIVER_DESC " " DRIVER_VERSION);
+
+	/* Register with the usb */
+	retval = usb_register(&usb_driver);
+	if (retval)
+		goto failed_usb_register;
+
+	return 0;
+
+failed_usb_register:
+	usb_serial_deregister(&moschip7720_2port_driver);
+
+failed_port_device_register:
+	return retval;
+}
+
+static void __exit moschip7720_exit(void)
+{
+	usb_deregister(&usb_driver);
+	usb_serial_deregister(&moschip7720_2port_driver);
+}
+
+module_init(moschip7720_init);
+module_exit(moschip7720_exit);
+
+/* Module information */
+MODULE_AUTHOR( DRIVER_AUTHOR );
+MODULE_DESCRIPTION( DRIVER_DESC );
+MODULE_LICENSE("GPL");
+
+module_param(debug, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Debug enabled or not");