[PATCH] cypress_m8: add usb-serial driver 'cypress_m8' to kernel tree

This patch adds the cypress_m8 usb-serial driver for the Delorme Earthmate usb gps and the Cypress hid->com rs232 adapter to the kernel tree.
Signed-off-by: Lonnie Mendez <lmendez19@austin.rr.com>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

Documentation/usb/usb-serial.txt

@@ -211,6 +211,62 @@ ZyXEL omni.net lcd plus ISDN TA
   azummo@towertech.it
 
 
+Cypress M8 CY4601 Family Serial Driver
+
+  This driver was in most part developed by Neil "koyama" Whelchel.  It
+  has been improved since that previous form to support dynamic serial
+  line settings and improved line handling.  The driver is for the most
+  part stable and has been tested on an smp machine. (dual p2)
+
+    Chipsets supported under CY4601 family:
+	
+		CY7C63723, CY7C63742, CY7C63743, CY7C64013
+
+    Devices supported:
+
+		-DeLorme's USB Earthmate (SiRF Star II lp arch)
+		-Cypress HID->COM RS232 adapter
+	
+		Note: Cypress Semiconductor claims no affiliation with the
+			the hid->com device.
+
+	Most devices using chipsets under the CY4601 family should
+     work with the driver.  As long as they stay true to the CY4601
+     usbserial specification.
+
+    Technical notes:
+
+        The Earthmate starts out at 4800 8N1 by default... the driver will
+	upon start init to this setting.  usbserial core provides the rest
+	of the termios settings, along with some custom termios so that the
+	output is in proper format and parsable.
+	
+	The device can be put into sirf mode by issuing NMEA command:
+		$PSRF100,<protocol>,<baud>,<databits>,<stopbits>,<parity>*CHECKSUM
+		$PSRF100,0,9600,8,1,0*0C
+
+		It should then be sufficient to change the port termios to match this
+		to begin communicating.
+
+	As far as I can tell it supports pretty much every sirf command as
+	documented online available with firmware 2.31, with some unknown
+	message ids.
+
+	The hid->com adapter can run at a maximum baud of 115200bps.  Please note
+	that the device has trouble or is incapable of raising line voltage properly.
+	It will be fine with null modem links, as long as you do not try to link two
+	together without hacking the adapter to set the line high.
+
+	The driver is smp safe.  Performance with the driver is rather low when using
+	it for transfering files.  This is being worked on, but I would be willing to
+	accept patches.  An urb queue or packet buffer would likely fit the bill here.
+
+	If you have any questions, problems, patches, feature requests, etc. you can
+	contact me here via email:
+					dignome@gmail.com
+		(your problems/patches can alternately be submitted to usb-devel)
+
+
 Digi AccelePort Driver
 
   This driver supports the Digi AccelePort USB 2 and 4 devices, 2 port

MAINTAINERS

@@ -2337,6 +2337,15 @@ L:	linux-usb-users@lists.sourceforge.net
 L:	linux-usb-devel@lists.sourceforge.net
 S:	Maintained
 
+USB SERIAL CYPRESS M8 DRIVER
+P:	Lonnie Mendez
+M:	dignome@gmail.com
+L:	linux-usb-users@lists.sourceforge.net
+L:	linux-usb-devel@lists.sourceforge.net
+S:	Maintained
+W:	http://geocities.com/i0xox0i
+W:	http://firstlight.net/cvs
+
 USB SERIAL CYBERJACK PINPAD/E-COM DRIVER
 L:	linux-usb-users@lists.sourceforge.net
 L:	linux-usb-devel@lists.sourceforge.net

drivers/usb/serial/Kconfig

@@ -89,6 +89,21 @@ config USB_SERIAL_DIGI_ACCELEPORT
 	  To compile this driver as a module, choose M here: the
 	  module will be called digi_acceleport.
 
+config USB_SERIAL_CYPRESS_M8
+	tristate "USB Cypress M8 USB Serial Driver"
+	depends on USB_SERIAL && EXPERIMENTAL
+	help
+	  Say Y here if you want to use a device that contains the Cypress
+	  USB to Serial microcontroller, such as the DeLorme Earthmate GPS.
+
+		Attempted SMP support... send bug reports!
+
+	  Supported microcontrollers in the CY4601 family are:
+		CY7C63741 CY7C63742 CY7C63743 CY7C64013
+	
+	  To compile this driver as a module, choose M here: the
+	  module will be called cypress_m8.
+
 config USB_SERIAL_EMPEG
 	tristate "USB Empeg empeg-car Mark I/II Driver"
 	depends on USB_SERIAL

drivers/usb/serial/Makefile

@@ -13,6 +13,7 @@ usbserial-objs	:= usb-serial.o generic.o bus.o $(usbserial-obj-y)
 
 obj-$(CONFIG_USB_SERIAL_BELKIN)			+= belkin_sa.o
 obj-$(CONFIG_USB_SERIAL_CYBERJACK)		+= cyberjack.o
+obj-$(CONFIG_USB_SERIAL_CYPRESS_M8)		+= cypress_m8.o
 obj-$(CONFIG_USB_SERIAL_DIGI_ACCELEPORT)	+= digi_acceleport.o
 obj-$(CONFIG_USB_SERIAL_EDGEPORT)		+= io_edgeport.o
 obj-$(CONFIG_USB_SERIAL_EDGEPORT_TI)		+= io_ti.o

drivers/usb/serial/cypress_m8.c

+/*
+ * USB Cypress M8 driver
+ *
+ * 	Copyright (C) 2004
+ * 	    Lonnie Mendez (dignome@gmail.com) 
+ *	Copyright (C) 2003,2004
+ *	    Neil Whelchel (koyama@firstlight.net)
+ *
+ * 	This program is free software; you can redistribute it and/or modify
+ * 	it under the terms of the GNU General Public License as published by
+ * 	the Free Software Foundation; either version 2 of the License, or
+ * 	(at your option) any later version.
+ *
+ * See Documentation/usb/usb-serial.txt for more information on using this driver
+ *
+ * See http://geocities.com/i0xox0i for information on this driver and the
+ * earthmate usb device.
+ *
+ *
+ *  Lonnie Mendez <dignome@gmail.com>
+ *  04-10-2004
+ *	Driver modified to support dynamic line settings.  Various improvments
+ *      and features.
+ *
+ *  Neil Whelchel
+ *  10-2003
+ *	Driver first released.
+ *
+ *
+ * Long Term TODO:
+ *	Improve transfer speeds - both read/write are somewhat slow
+ *   at this point.
+ */
+
+/* Neil Whelchel wrote the cypress m8 implementation */
+/* Thanks to cypress for providing references for the hid reports. */
+/* Thanks to Jiang Zhang for providing links and for general help. */
+/* Code originates and was built up from ftdi_sio, belkin, pl2303 and others. */
+
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/spinlock.h>
+#include <asm/uaccess.h>
+#include <linux/usb.h>
+#include <linux/serial.h>
+
+#ifdef CONFIG_USB_SERIAL_DEBUG
+	static int debug = 1;
+#else
+	static int debug;
+#endif
+
+static int stats;
+
+#include "usb-serial.h"
+#include "cypress_m8.h"
+
+/*
+ * Version Information
+ */
+#define DRIVER_VERSION "v1.06"
+#define DRIVER_AUTHOR "Lonnie Mendez <dignome@gmail.com>, Neil Whelchel <koyama@firstlight.net>"
+#define DRIVER_DESC "Cypress USB to Serial Driver"
+
+static struct usb_device_id id_table_earthmate [] = {
+	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
+	{ }						/* Terminating entry */
+};
+
+static struct usb_device_id id_table_cyphidcomrs232 [] = {
+	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
+	{ }						/* Terminating entry */
+};
+
+static struct usb_device_id id_table_combined [] = {
+	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
+	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
+	{ }						/* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE (usb, id_table_combined);
+
+static struct usb_driver cypress_driver = {
+	.name =		"cypress",
+	.probe =	usb_serial_probe,
+	.disconnect =	usb_serial_disconnect,
+	.id_table =	id_table_combined,
+};
+
+struct cypress_private {
+	spinlock_t lock;		   /* private lock */
+	int chiptype;			   /* identifier of device, for quirks/etc */
+	int bytes_in;			   /* used for statistics */
+	int bytes_out;			   /* used for statistics */
+	int cmd_count;			   /* used for statistics */
+	int cmd_ctrl;			   /* always set this to 1 before issuing a command */
+	int termios_initialized;
+	__u8 line_control;	   	   /* holds dtr / rts value */
+	__u8 current_status;	   	   /* received from last read - info on dsr,cts,cd,ri,etc */
+	__u8 current_config;	   	   /* stores the current configuration byte */
+	__u8 rx_flags;			   /* throttling - used from whiteheat/ftdi_sio */
+	int baud_rate;			   /* stores current baud rate in integer form */
+	int cbr_mask;			   /* stores current baud rate in masked form */
+	int isthrottled;		   /* if throttled, discard reads */
+	wait_queue_head_t delta_msr_wait;  /* used for TIOCMIWAIT */
+	char prev_status, diff_status;	   /* used for TIOCMIWAIT */
+	/* we pass a pointer to this as the arguement sent to cypress_set_termios old_termios */
+	struct termios tmp_termios; 	   /* stores the old termios settings */
+	int write_interval;		   /* interrupt out write interval, as obtained from interrupt_out_urb */
+	int writepipe;			   /* used for clear halt, if necessary */
+};
+
+/* function prototypes for the Cypress USB to serial device */
+static int  cypress_earthmate_startup	(struct usb_serial *serial);
+static int  cypress_hidcom_startup	(struct usb_serial *serial);
+static void cypress_shutdown		(struct usb_serial *serial);
+static int  cypress_open		(struct usb_serial_port *port, struct file *filp);
+static void cypress_close		(struct usb_serial_port *port, struct file *filp);
+static int  cypress_write		(struct usb_serial_port *port, const unsigned char *buf, int count);
+static int  cypress_write_room		(struct usb_serial_port *port);
+static int  cypress_ioctl		(struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg);
+static void cypress_set_termios		(struct usb_serial_port *port, struct termios * old);
+static int  cypress_tiocmget		(struct usb_serial_port *port, struct file *file);
+static int  cypress_tiocmset		(struct usb_serial_port *port, struct file *file, unsigned int set, unsigned int clear);
+static int  cypress_chars_in_buffer	(struct usb_serial_port *port);
+static void cypress_throttle		(struct usb_serial_port *port);
+static void cypress_unthrottle		(struct usb_serial_port *port);
+static void cypress_read_int_callback	(struct urb *urb, struct pt_regs *regs);
+static void cypress_write_int_callback	(struct urb *urb, struct pt_regs *regs);
+static int  mask_to_rate		(unsigned mask);
+static unsigned rate_to_mask		(int rate);
+
+static struct usb_serial_device_type cypress_earthmate_device = {
+	.owner =			THIS_MODULE,
+	.name =				"DeLorme Earthmate USB",
+	.short_name =			"earthmate",
+	.id_table =			id_table_earthmate,
+	.num_interrupt_in = 		1,
+	.num_interrupt_out =		1,
+	.num_bulk_in =			NUM_DONT_CARE,
+	.num_bulk_out =			NUM_DONT_CARE,
+	.num_ports =			1,
+	.attach =			cypress_earthmate_startup,
+	.shutdown =			cypress_shutdown,
+	.open =				cypress_open,
+	.close =			cypress_close,
+	.write =			cypress_write,
+	.write_room =			cypress_write_room,
+	.ioctl =			cypress_ioctl,
+	.set_termios =			cypress_set_termios,
+	.tiocmget =			cypress_tiocmget,
+	.tiocmset =			cypress_tiocmset,
+	.chars_in_buffer =		cypress_chars_in_buffer,
+	.throttle =		 	cypress_throttle,
+	.unthrottle =			cypress_unthrottle,
+	.read_int_callback =		cypress_read_int_callback,
+	.write_int_callback =		cypress_write_int_callback,
+};
+
+static struct usb_serial_device_type cypress_hidcom_device = {
+	.owner =			THIS_MODULE,
+	.name =				"HID->COM RS232 Adapter",
+	.short_name =			"cyphidcom",
+	.id_table =			id_table_cyphidcomrs232,
+	.num_interrupt_in =		1,
+	.num_interrupt_out =		1,
+	.num_bulk_in =			NUM_DONT_CARE,
+	.num_bulk_out =			NUM_DONT_CARE,
+	.num_ports =			1,
+	.attach =			cypress_hidcom_startup,
+	.shutdown =			cypress_shutdown,
+	.open =				cypress_open,
+	.close =			cypress_close,
+	.write =			cypress_write,
+	.write_room =			cypress_write_room,
+	.ioctl =			cypress_ioctl,
+	.set_termios =			cypress_set_termios,
+	.tiocmget =			cypress_tiocmget,
+	.tiocmset =			cypress_tiocmset,
+	.chars_in_buffer =		cypress_chars_in_buffer,
+	.throttle =			cypress_throttle,
+	.unthrottle =			cypress_unthrottle,
+	.read_int_callback =		cypress_read_int_callback,
+	.write_int_callback =		cypress_write_int_callback,
+};
+
+
+/*****************************************************************************
+ * Cypress serial helper functions
+ *****************************************************************************/
+
+
+/* This function can either set or retreive the current serial line settings */
+static int cypress_serial_control (struct usb_serial_port *port, unsigned baud_mask, int data_bits, int stop_bits,
+				   int parity_enable, int parity_type, int reset, int cypress_request_type)
+{
+	int i, n_baud_rate = 0, retval = 0;
+	struct cypress_private *priv;
+	__u8 feature_buffer[5];
+	__u8 config;
+	unsigned long flags;
+
+	dbg("%s", __FUNCTION__);
+	
+	priv = usb_get_serial_port_data(port);
+
+	switch(cypress_request_type) {
+		case CYPRESS_SET_CONFIG:
+
+			/*
+			 * The general purpose firmware for the Cypress M8 allows for a maximum speed
+ 			 * of 57600bps (I have no idea whether DeLorme chose to use the general purpose
+			 * firmware or not), if you need to modify this speed setting for your own
+			 * project please add your own chiptype and modify the code likewise.  The
+			 * Cypress HID->COM device will work successfully up to 115200bps.
+			 */
+			if (baud_mask != priv->cbr_mask) {
+				dbg("%s - baud rate is changing", __FUNCTION__);
+				if ( priv->chiptype == CT_EARTHMATE ) {
+					/* 300 and 600 baud rates are supported under the generic firmware,
+					 * but are not used with NMEA and SiRF protocols */
+					
+					if ( (baud_mask == B300) || (baud_mask == B600) ) {
+						err("%s - failed setting baud rate, unsupported speed (default to 4800)",
+						    __FUNCTION__);
+						n_baud_rate = 4800;
+					} else if ( (n_baud_rate = mask_to_rate(baud_mask)) == -1) {
+						err("%s - failed setting baud rate, unsupported speed (default to 4800)",
+						    __FUNCTION__);
+						n_baud_rate = 4800;
+					}
+				} else if (priv->chiptype == CT_CYPHIDCOM) {
+					if ( (n_baud_rate = mask_to_rate(baud_mask)) == -1) {
+						err("%s - failed setting baud rate, unsupported speed (default to 4800)",
+						    __FUNCTION__);
+						n_baud_rate = 4800;
+					}
+				} else if (priv->chiptype == CT_GENERIC) {
+					if ( (n_baud_rate = mask_to_rate(baud_mask)) == -1) {
+						err("%s - failed setting baud rate, unsupported speed (default to 4800)",
+						    __FUNCTION__);
+						n_baud_rate = 4800;
+					}
+				} else {
+					info("%s - please define your chiptype, using 4800bps default", __FUNCTION__);
+					n_baud_rate = 4800;
+				}
+			} else {  /* baud rate not changing, keep the old */
+				n_baud_rate = priv->baud_rate;
+			}
+			dbg("%s - baud rate is being sent as %d", __FUNCTION__, n_baud_rate);
+
+			
+			/*
+			 * This algorithm accredited to Jiang Jay Zhang... thanks for all the help!
+			 */
+			for (i = 0; i < 4; ++i) {
+				feature_buffer[i] = ( n_baud_rate >> (i*8) & 0xFF );
+			}
+
+			config = 0;	                 // reset config byte
+			config |= data_bits;	         // assign data bits in 2 bit space ( max 3 )
+			/* 1 bit gap */
+			config |= (stop_bits << 3);      // assign stop bits in 1 bit space
+			config |= (parity_enable << 4);  // assign parity flag in 1 bit space
+			config |= (parity_type << 5); 	 // assign parity type in 1 bit space
+			/* 1 bit gap */
+			config |= (reset << 7);		 // assign reset at end of byte, 1 bit space
+
+			feature_buffer[4] = config;
+				
+			dbg("%s - device is being sent this feature report:", __FUNCTION__);
+			dbg("%s - %02X - %02X - %02X - %02X - %02X", __FUNCTION__, feature_buffer[0], feature_buffer[1],
+		            feature_buffer[2], feature_buffer[3], feature_buffer[4]);
+			
+			retval = usb_control_msg (port->serial->dev, usb_sndctrlpipe(port->serial->dev, 0),
+					  	  HID_REQ_SET_REPORT, USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
+					  	  0x0300, 0, feature_buffer, 5, 500);
+
+			if (retval != 5)
+				err("%s - failed sending serial line settings - %d", __FUNCTION__, retval);
+			else {
+				spin_lock_irqsave(&priv->lock, flags);
+				priv->baud_rate = n_baud_rate;
+				priv->cbr_mask = baud_mask;
+				priv->current_config = config;
+				++priv->cmd_count;
+				spin_unlock_irqrestore(&priv->lock, flags);
+			}
+		break;
+		case CYPRESS_GET_CONFIG:
+			dbg("%s - retreiving serial line settings", __FUNCTION__);
+			/* reset values in feature buffer */
+			memset(feature_buffer, 0, 5);
+
+			retval = usb_control_msg (port->serial->dev, usb_rcvctrlpipe(port->serial->dev, 0),
+						  HID_REQ_GET_REPORT, USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
+						  0x0300, 0, feature_buffer, 5, 500);
+			if (retval != 5) {
+				err("%s - failed to retreive serial line settings - %d", __FUNCTION__, retval);
+				return retval;
+			} else {
+				spin_lock_irqsave(&priv->lock, flags);
+				/* store the config in one byte, and later use bit masks to check values */
+				priv->current_config = feature_buffer[4];
+				/* reverse the process above to get the baud_mask value */
+				n_baud_rate = 0; // reset bits
+				for (i = 0; i < 4; ++i) {
+					n_baud_rate |= ( feature_buffer[i] << (i*8) );
+				}
+				
+				priv->baud_rate = n_baud_rate;
+				if ( (priv->cbr_mask = rate_to_mask(n_baud_rate)) == 0x40)
+					dbg("%s - failed setting the baud mask (not defined)", __FUNCTION__);
+				++priv->cmd_count;
+				spin_unlock_irqrestore(&priv->lock, flags);
+			}
+			break;
+		default:
+			err("%s - unsupported serial control command issued", __FUNCTION__);
+	}
+	return retval;
+} /* cypress_serial_control */
+
+
+/* given a baud mask, it will return speed on success */
+static int mask_to_rate (unsigned mask)
+{
+	int rate;
+
+	switch (mask) {
+		case B0: rate = 0; break;
+		case B300: rate = 300; break;
+		case B600: rate = 600; break;
+		case B1200: rate = 1200; break;
+		case B2400: rate = 2400; break;
+		case B4800: rate = 4800; break;
+		case B9600: rate = 9600; break;
+		case B19200: rate = 19200; break;
+		case B38400: rate = 38400; break;
+		case B57600: rate = 57600; break;
+		case B115200: rate = 115200; break;
+		default: rate = -1;
+	}
+
+	return rate;
+}
+
+
+static unsigned rate_to_mask (int rate)
+{
+	unsigned mask;
+
+	switch (rate) {
+		case 0: mask = B0; break;
+		case 300: mask = B300; break;
+		case 600: mask = B600; break;
+		case 1200: mask = B1200; break;
+		case 2400: mask = B2400; break;
+		case 4800: mask = B4800; break;
+		case 9600: mask = B9600; break;
+		case 19200: mask = B19200; break;
+		case 38400: mask = B38400; break;
+		case 57600: mask = B57600; break;
+		case 115200: mask = B115200; break;
+		default: mask = 0x40;
+	}
+
+	return mask;
+}
+/*****************************************************************************
+ * Cypress serial driver functions
+ *****************************************************************************/
+
+
+static int generic_startup (struct usb_serial *serial)
+{
+	struct cypress_private *priv;
+
+	dbg("%s - port %d", __FUNCTION__, serial->port[0]->number);
+
+	priv = kmalloc(sizeof (struct cypress_private), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	memset(priv, 0x00, sizeof (struct cypress_private));
+	spin_lock_init(&priv->lock);
+	init_waitqueue_head(&priv->delta_msr_wait);
+	priv->writepipe = serial->port[0]->interrupt_out_urb->pipe;
+	
+	/* free up interrupt_out buffer / urb allocated by usbserial
+ 	 * for this port as we use our own urbs for writing */
+	if (serial->port[0]->interrupt_out_buffer) {
+		kfree(serial->port[0]->interrupt_out_buffer);
+		serial->port[0]->interrupt_out_buffer = NULL;
+	}
+	if (serial->port[0]->interrupt_out_urb) {
+		priv->write_interval = serial->port[0]->interrupt_out_urb->interval;
+		usb_free_urb(serial->port[0]->interrupt_out_urb);
+		serial->port[0]->interrupt_out_urb = NULL;
+	} else /* still need a write interval */
+		priv->write_interval = 10;
+
+	priv->cmd_ctrl = 0;
+	priv->line_control = 0;
+	priv->termios_initialized = 0;
+	priv->rx_flags = 0;
+	usb_set_serial_port_data(serial->port[0], priv);
+	
+	return (0);	
+}	
+
+
+static int cypress_earthmate_startup (struct usb_serial *serial)
+{
+	struct cypress_private *priv;
+
+	dbg("%s", __FUNCTION__);
+
+	if (generic_startup(serial)) {
+		dbg("%s - Failed setting up port %d", __FUNCTION__, serial->port[0]->number);
+		return 1;
+	}
+
+	priv = usb_get_serial_port_data(serial->port[0]);
+	priv->chiptype = CT_EARTHMATE;
+	
+	return (0);	
+} /* cypress_earthmate_startup */
+
+
+static int cypress_hidcom_startup (struct usb_serial *serial)
+{
+	struct cypress_private *priv;
+
+	dbg("%s", __FUNCTION__);
+
+	if (generic_startup(serial)) {
+		dbg("%s - Failed setting up port %d", __FUNCTION__, serial->port[0]->number);
+		return 1;
+	}
+
+	priv = usb_get_serial_port_data(serial->port[0]);
+	priv->chiptype = CT_CYPHIDCOM;
+	
+	return (0);	
+} /* cypress_hidcom_startup */
+
+
+static void cypress_shutdown (struct usb_serial *serial)
+{
+	struct cypress_private *priv;
+
+	dbg ("%s - port %d", __FUNCTION__, serial->port[0]->number);
+
+	/* all open ports are closed at this point */
+
+	priv = usb_get_serial_port_data(serial->port[0]);
+
+	if (priv) {
+		kfree(priv);
+		usb_set_serial_port_data(serial->port[0], NULL);
+	}
+}
+
+
+static int cypress_open (struct usb_serial_port *port, struct file *filp)
+{
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	struct usb_serial *serial = port->serial;
+	unsigned long flags;
+	int result = 0;
+
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	/* reset read/write statistics */
+	priv->bytes_in = 0;
+	priv->bytes_out = 0;
+	priv->cmd_count = 0;
+
+	/* turn on dtr / rts since we are not flow controlling by default */
+	priv->line_control = CONTROL_DTR | CONTROL_RTS; /* sent in status byte */
+	spin_unlock_irqrestore(&priv->lock, flags);
+	priv->cmd_ctrl = 1;
+	result = cypress_write(port, NULL, 0);
+	
+	port->tty->low_latency = 1;
+
+	/* termios defaults are set by usb_serial_init */
+	
+	cypress_set_termios(port, &priv->tmp_termios);
+
+	if (result) {
+		dev_err(&port->dev, "%s - failed setting the control lines - error %d\n", __FUNCTION__, result);
+		return result;
+	} else
+		dbg("%s - success setting the control lines", __FUNCTION__);
+
+	/* throttling off */
+	spin_lock_irqsave(&priv->lock, flags);
+	priv->rx_flags = 0;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	/* setup the port and
+	 * start reading from the device */
+	if(!port->interrupt_in_urb){
+		err("%s - interrupt_in_urb is empty!", __FUNCTION__);
+		return(-1);
+	}
+
+	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
+		usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
+		port->interrupt_in_urb->transfer_buffer, port->interrupt_in_urb->transfer_buffer_length,
+		cypress_read_int_callback, port, port->interrupt_in_urb->interval);
+	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
+
+	if (result){
+		dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);
+	}
+
+	return result;
+} /* cypress_open */
+
+
+static void cypress_close(struct usb_serial_port *port, struct file * filp)
+{
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	unsigned int c_cflag;
+	unsigned long flags;
+
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	if (port->tty) {
+		c_cflag = port->tty->termios->c_cflag;
+		if (c_cflag & HUPCL) {
+			/* drop dtr and rts */
+			priv = usb_get_serial_port_data(port);
+			spin_lock_irqsave(&priv->lock, flags);
+			priv->line_control = 0;
+			priv->cmd_ctrl = 1;
+			spin_unlock_irqrestore(&priv->lock, flags);
+			cypress_write(port, NULL, 0);
+		}
+	}
+
+	if (port->interrupt_in_urb) {
+		dbg("%s - stopping read urb", __FUNCTION__);
+		usb_kill_urb (port->interrupt_in_urb);
+	}
+
+	if (stats)
+		dev_info (&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
+		          priv->bytes_in, priv->bytes_out, priv->cmd_count);
+} /* cypress_close */
+
+
+static int cypress_write(struct usb_serial_port *port, const unsigned char *buf, int count)
+{
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	struct urb *urb;
+	int status, s_pos = 0;
+	__u8 transfer_size = 0;
+	__u8 *buffer;
+
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (count == 0 && !priv->cmd_ctrl) {
+		spin_unlock_irqrestore(&priv->lock, flags);
+		dbg("%s - write request of 0 bytes", __FUNCTION__);
+		return 0;
+	}
+
+	if (priv->cmd_ctrl)
+		++priv->cmd_count;
+	priv->cmd_ctrl = 0;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	dbg("%s - interrupt out size is %d", __FUNCTION__, port->interrupt_out_size);
+	dbg("%s - count is %d", __FUNCTION__, count);
+
+	/* Allocate buffer and urb */
+	buffer = kmalloc (port->interrupt_out_size, GFP_ATOMIC);
+	if (!buffer) {
+		dev_err(&port->dev, "ran out of memory for buffer\n");
+		return -ENOMEM;
+	}
+
+	urb = usb_alloc_urb (0, GFP_ATOMIC);
+	if (!urb) {
+		dev_err(&port->dev, "failed allocating write urb\n");
+		kfree (buffer);
+		return -ENOMEM;
+	}
+
+	memset(buffer, 0, port->interrupt_out_size); // test if this is needed... probably not since loop removed
+
+	spin_lock_irqsave(&priv->lock, flags);
+	switch (port->interrupt_out_size) {
+		case 32:
+			// this is for the CY7C64013...
+			transfer_size = min (count, 30);
+			buffer[0] = priv->line_control;
+			buffer[1] = transfer_size;
+			s_pos = 2;
+			break;
+		case 8:
+			// this is for the CY7C63743...
+			transfer_size = min (count, 7);
+			buffer[0] = priv->line_control | transfer_size;
+			s_pos = 1;
+			break;
+		default:
+			dbg("%s - wrong packet size", __FUNCTION__);
+			spin_unlock_irqrestore(&priv->lock, flags);
+			kfree (buffer);
+			usb_free_urb (urb);
+			return -1;
+	}
+
+	if (priv->line_control & CONTROL_RESET)
+		priv->line_control &= ~CONTROL_RESET;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	/* copy data to offset position in urb transfer buffer */
+	memcpy (&buffer[s_pos], buf, transfer_size);
+
+	usb_serial_debug_data (debug, &port->dev, __FUNCTION__, port->interrupt_out_size, buffer);
+
+	/* build up the urb */
+	usb_fill_int_urb (urb, port->serial->dev,
+			  usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
+			  buffer, port->interrupt_out_size,
+			  cypress_write_int_callback, port, priv->write_interval);
+
+	status = usb_submit_urb(urb, GFP_ATOMIC);
+
+	if (status) {
+		dev_err(&port->dev, "%s - usb_submit_urb (write interrupt) failed with status %d\n",
+			__FUNCTION__, status);
+		transfer_size = status;
+		kfree (buffer);
+		goto exit;
+	}
+
+	spin_lock_irqsave(&priv->lock, flags);
+	priv->bytes_out += transfer_size;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+exit:
+	/* buffer free'd in callback */
+	usb_free_urb (urb);
+
+	return transfer_size;
+
+} /* cypress_write */
+
+
+static int cypress_write_room(struct usb_serial_port *port)
+{
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	/*
+	 * We really can take anything the user throw at us
+	 * but let's pick a nice big number to tell the tty
+	 * layer that we have lots of free space
+	 */	
+
+	return 2048;
+}
+
+
+static int cypress_tiocmget (struct usb_serial_port *port, struct file *file)
+{
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	__u8 status, control;
+	unsigned int result = 0;
+	unsigned long flags;
+	
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	control = priv->line_control;
+	status = priv->current_status;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
+		| ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
+		| ((status & UART_CTS)        ? TIOCM_CTS : 0)
+		| ((status & UART_DSR)        ? TIOCM_DSR : 0)
+		| ((status & UART_RI)         ? TIOCM_RI  : 0)
+		| ((status & UART_CD)         ? TIOCM_CD  : 0);
+
+	dbg("%s - result = %x", __FUNCTION__, result);
+
+	return result;
+}
+
+
+static int cypress_tiocmset (struct usb_serial_port *port, struct file *file,
+			       unsigned int set, unsigned int clear)
+{
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (set & TIOCM_RTS)
+		priv->line_control |= CONTROL_RTS;
+	if (set & TIOCM_DTR)
+		priv->line_control |= CONTROL_DTR;
+	if (clear & TIOCM_RTS)
+		priv->line_control &= ~CONTROL_RTS;
+	if (clear & TIOCM_DTR)
+		priv->line_control &= ~CONTROL_DTR;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	priv->cmd_ctrl = 1;
+	return cypress_write(port, NULL, 0);
+}
+
+
+static int cypress_ioctl (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg)
+{
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+
+	dbg("%s - port %d, cmd 0x%.4x", __FUNCTION__, port->number, cmd);
+
+	switch (cmd) {
+		case TIOCGSERIAL:
+			if (copy_to_user((void *)arg, port->tty->termios, sizeof(struct termios))) {
+				return -EFAULT;
+			}
+			return (0);
+			break;
+		case TIOCSSERIAL:
+			if (copy_from_user(port->tty->termios, (void *)arg, sizeof(struct termios))) {
+				return -EFAULT;
+			}
+			/* here we need to call cypress_set_termios to invoke the new settings */
+			cypress_set_termios(port, &priv->tmp_termios);
+			return (0);
+			break;
+		/* these are called when setting baud rate from gpsd */
+		case TCGETS:
+			if (copy_to_user((void *)arg, port->tty->termios, sizeof(struct termios))) {
+				return -EFAULT;
+			}
+			return (0);
+			break;
+		case TCSETS:
+			if (copy_from_user(port->tty->termios, (void *)arg, sizeof(struct termios))) {
+				return -EFAULT;
+			}
+			/* here we need to call cypress_set_termios to invoke the new settings */
+			cypress_set_termios(port, &priv->tmp_termios);
+			return (0);
+			break;
+		/* This code comes from drivers/char/serial.c and ftdi_sio.c */
+		case TIOCMIWAIT:
+			while (priv != NULL) {
+				interruptible_sleep_on(&priv->delta_msr_wait);
+				/* see if a signal did it */
+				if (signal_pending(current))
+					return -ERESTARTSYS;
+				else {
+					char diff = priv->diff_status;
+
+					if (diff == 0) {
+						return -EIO; /* no change => error */
+					}
+					
+					/* consume all events */
+					priv->diff_status = 0;
+
+					/* return 0 if caller wanted to know about these bits */
+					if ( ((arg & TIOCM_RNG) && (diff & UART_RI)) ||
+					     ((arg & TIOCM_DSR) && (diff & UART_DSR)) ||
+					     ((arg & TIOCM_CD) && (diff & UART_CD)) ||
+					     ((arg & TIOCM_CTS) && (diff & UART_CTS)) ) {
+						return 0;
+					}
+					/* otherwise caller can't care less about what happened,
+					 * and so we continue to wait for more events.
+					 */
+				}
+			}
+			return 0;
+			break;
+		default:
+			break;
+	}
+
+	dbg("%s - arg not supported - it was 0x%04x - check include/asm/ioctls.h", __FUNCTION__, cmd);
+
+	return -ENOIOCTLCMD;
+} /* cypress_ioctl */
+
+
+static void cypress_set_termios (struct usb_serial_port *port, struct termios *old_termios)
+{
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	struct tty_struct *tty;
+	int data_bits, stop_bits, parity_type, parity_enable;
+	unsigned cflag, iflag, baud_mask;
+	unsigned long flags;
+	
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	tty = port->tty;
+	if ((!tty) || (!tty->termios)) {
+		dbg("%s - no tty structures", __FUNCTION__);
+		return;
+	}
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (!priv->termios_initialized) {
+		if (priv->chiptype == CT_EARTHMATE) {
+			*(tty->termios) = tty_std_termios;
+			tty->termios->c_cflag = B4800 | CS8 | CREAD | HUPCL | CLOCAL;
+		} else if (priv->chiptype == CT_CYPHIDCOM) {
+			*(tty->termios) = tty_std_termios;
+			tty->termios->c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+		}
+		priv->termios_initialized = 1;
+	}
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	cflag = tty->termios->c_cflag;
+	iflag = tty->termios->c_iflag;
+
+	/* check if there are new settings */
+	if (old_termios) {
+		if ((cflag != old_termios->c_cflag) ||
+		    (RELEVANT_IFLAG(iflag) != RELEVANT_IFLAG(old_termios->c_iflag))) {
+			dbg("%s - attempting to set new termios settings", __FUNCTION__);
+			/* should make a copy of this in case something goes wrong in the function, we can restore it */
+			spin_lock_irqsave(&priv->lock, flags);
+			priv->tmp_termios = *(tty->termios);
+			spin_unlock_irqrestore(&priv->lock, flags); 
+		} else {
+			dbg("%s - nothing to do, exiting", __FUNCTION__);
+			return;
+		}
+	} else
+		return;
+
+	/* set number of data bits, parity, stop bits */
+	/* when parity is disabled the parity type bit is ignored */
+
+	stop_bits = cflag & CSTOPB ? 1 : 0; /* 1 means 2 stop bits, 0 means 1 stop bit */
+	
+	if (cflag & PARENB) {
+		parity_enable = 1;
+		parity_type = cflag & PARODD ? 1 : 0; /* 1 means odd parity, 0 means even parity */
+	} else
+		parity_enable = parity_type = 0;
+
+	if (cflag & CSIZE) {
+		switch (cflag & CSIZE) {
+			case CS5: data_bits = 0; break;
+			case CS6: data_bits = 1; break;
+			case CS7: data_bits = 2; break;
+			case CS8: data_bits = 3; break;
+			default: err("%s - CSIZE was set, but not CS5-CS8", __FUNCTION__); data_bits = 3;
+		}
+	} else
+		data_bits = 3;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if ((cflag & CBAUD) == B0) {
+		/* drop dtr and rts */
+		dbg("%s - dropping the lines, baud rate 0bps", __FUNCTION__);
+		baud_mask = B0;
+		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
+	} else {
+		baud_mask = (cflag & CBAUD);
+		switch(baud_mask) {
+			case B300: dbg("%s - setting baud 300bps", __FUNCTION__); break;
+			case B600: dbg("%s - setting baud 600bps", __FUNCTION__); break;
+			case B1200: dbg("%s - setting baud 1200bps", __FUNCTION__); break;
+			case B2400: dbg("%s - setting baud 2400bps", __FUNCTION__); break;
+			case B4800: dbg("%s - setting baud 4800bps", __FUNCTION__); break;
+			case B9600: dbg("%s - setting baud 9600bps", __FUNCTION__); break;
+			case B19200: dbg("%s - setting baud 19200bps", __FUNCTION__); break;
+			case B38400: dbg("%s - setting baud 38400bps", __FUNCTION__); break;
+			case B57600: dbg("%s - setting baud 57600bps", __FUNCTION__); break;
+			case B115200: dbg("%s - setting baud 115200bps", __FUNCTION__); break;
+			default: dbg("%s - unknown masked baud rate", __FUNCTION__);
+		}
+		priv->line_control |= CONTROL_DTR;
+		
+		/* this is probably not what I think it is... check into it */
+		if (cflag & CRTSCTS)
+			priv->line_control |= CONTROL_RTS;
+		else
+			priv->line_control &= ~CONTROL_RTS;
+	}
+	spin_unlock_irqrestore(&priv->lock, flags);
+	
+	dbg("%s - sending %d stop_bits, %d parity_enable, %d parity_type, %d data_bits (+5)", __FUNCTION__,
+	    stop_bits, parity_enable, parity_type, data_bits);
+
+	cypress_serial_control(port, baud_mask, data_bits, stop_bits, parity_enable,
+			       parity_type, 0, CYPRESS_SET_CONFIG);
+
+	set_current_state(TASK_INTERRUPTIBLE);
+	schedule_timeout(50*HZ/1000); /* give some time between change and read (50ms) */ 
+
+	/* we perform a CYPRESS_GET_CONFIG so that the current settings are filled into the private structure
+         * this should confirm that all is working if it returns what we just set */
+	cypress_serial_control(port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
+
+	/* Here we can define custom tty settings for devices
+         *
+         * the main tty base comes from empeg.c
+         */
+
+	spin_lock_irqsave(&priv->lock, flags);	
+	if ( (priv->chiptype == CT_EARTHMATE) && (priv->baud_rate == 4800) ) {
+
+		dbg("Using custom termios settings for a baud rate of 4800bps.");
+		/* define custom termios settings for NMEA protocol */
+
+		
+		tty->termios->c_iflag /* input modes - */
+			&= ~(IGNBRK		/* disable ignore break */
+			| BRKINT		/* disable break causes interrupt */
+			| PARMRK		/* disable mark parity errors */
+			| ISTRIP		/* disable clear high bit of input characters */
+			| INLCR			/* disable translate NL to CR */
+			| IGNCR			/* disable ignore CR */
+			| ICRNL			/* disable translate CR to NL */
+			| IXON);		/* disable enable XON/XOFF flow control */
+		
+		tty->termios->c_oflag /* output modes */
+			&= ~OPOST;		/* disable postprocess output characters */
+		
+		tty->termios->c_lflag /* line discipline modes */
+			&= ~(ECHO 		/* disable echo input characters */
+			| ECHONL		/* disable echo new line */
+			| ICANON		/* disable erase, kill, werase, and rprnt special characters */
+			| ISIG			/* disable interrupt, quit, and suspend special characters */
+			| IEXTEN);		/* disable non-POSIX special characters */
+
+	} else if (priv->chiptype == CT_CYPHIDCOM) {
+
+		// Software app handling it for device...	
+
+	} else {
+		
+		/* do something here */
+
+	}
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	/* set lines */
+	priv->cmd_ctrl = 1;
+	cypress_write(port, NULL, 0);
+	
+	return;
+} /* cypress_set_termios */
+
+
+static int cypress_chars_in_buffer(struct usb_serial_port *port)
+{
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	/*
+	 * We can't really account for how much data we
+	 * have sent out, but hasn't made it through to the
+	 * device, so just tell the tty layer that everything
+	 * is flushed.
+	 */
+
+	return 0;
+}
+
+
+static void cypress_throttle (struct usb_serial_port *port)
+{
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	priv->rx_flags = THROTTLED;
+	spin_unlock_irqrestore(&priv->lock, flags);	   
+}
+
+
+static void cypress_unthrottle (struct usb_serial_port *port)
+{
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	int actually_throttled, result;
+	unsigned long flags;
+
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
+	priv->rx_flags = 0;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	if (actually_throttled) {
+		port->interrupt_in_urb->dev = port->serial->dev;
+
+		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
+		if (result)
+			dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);
+	}
+}
+
+
+static void cypress_read_int_callback(struct urb *urb, struct pt_regs *regs)
+{
+	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	struct tty_struct *tty;
+	unsigned char *data = urb->transfer_buffer;
+	unsigned long flags;
+	char tty_flag = TTY_NORMAL;
+	int bytes=0;
+	int result;
+	int i=0;
+
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	if (urb->status) {
+		dbg("%s - nonzero read status received: %d", __FUNCTION__, urb->status);
+		return;
+	}
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (priv->rx_flags & THROTTLED) {
+		priv->rx_flags |= ACTUALLY_THROTTLED;
+		spin_unlock_irqrestore(&priv->lock, flags);
+		return;
+	}
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	tty = port->tty;
+	if (!tty) {
+		dbg("%s - bad tty pointer - exiting", __FUNCTION__);
+		return;
+	}
+
+	usb_serial_debug_data (debug, &port->dev, __FUNCTION__, urb->actual_length, data);
+	
+	spin_lock_irqsave(&priv->lock, flags);
+	switch(urb->actual_length) {
+		case 32:
+			// This is for the CY7C64013...
+			priv->current_status = data[0] & 0xF8;
+			bytes = data[1]+2;
+			i=2;
+			break;
+		case 8:
+			// This is for the CY7C63743...
+			priv->current_status = data[0] & 0xF8;
+			bytes = (data[0] & 0x07)+1;
+			i=1;
+			break;
+		default:
+			dbg("%s - wrong packet size - received %d bytes", __FUNCTION__, urb->actual_length);
+			spin_unlock_irqrestore(&priv->lock, flags);
+			goto continue_read;
+	}
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	/* check to see if status has changed */
+	if (priv != NULL) {
+		if (priv->current_status != priv->prev_status) {
+			priv->diff_status |= priv->current_status ^ priv->prev_status;
+			wake_up_interruptible(&priv->delta_msr_wait);
+			priv->prev_status = priv->current_status;
+		}
+	}
+	spin_unlock_irqrestore(&priv->lock, flags);	
+
+	/* hangup, as defined in acm.c... this might be a bad place for it though */
+	if (tty && !(tty->termios->c_cflag & CLOCAL) && !(priv->current_status & UART_CD)) {
+		dbg("%s - calling hangup", __FUNCTION__);
+		tty_hangup(tty);
+		goto continue_read;
+	}
+
+	/* There is one error bit... I'm assuming it is a parity error indicator
+	 * as the generic firmware will set this bit to 1 if a parity error occurs.
+	 * I can not find reference to any other error events.
+	 *
+	 */
+	spin_lock_irqsave(&priv->lock, flags);
+	if (priv->current_status & CYP_ERROR) {
+		spin_unlock_irqrestore(&priv->lock, flags);
+		tty_flag = TTY_PARITY;
+		dbg("%s - Parity Error detected", __FUNCTION__);
+	} else
+		spin_unlock_irqrestore(&priv->lock, flags);
+
+	/* process read if there is data other than line status */
+	if (tty && (bytes > i)) {
+		for (; i < bytes ; ++i) {
+			dbg("pushing byte number %d - %d",i,data[i]);
+			if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
+				tty_flip_buffer_push(tty);
+			}
+			tty_insert_flip_char(tty, data[i], tty_flag);
+		}
+		tty_flip_buffer_push(port->tty);
+	}
+
+	spin_lock_irqsave(&priv->lock, flags);
+	priv->bytes_in += bytes;  /* control and status byte(s) are also counted */
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+continue_read:
+	
+	/* Continue trying to always read... unless the port has closed.  */
+
+	if (port->open_count > 0) {
+	usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
+		usb_rcvintpipe(port->serial->dev, port->interrupt_in_endpointAddress),
+		port->interrupt_in_urb->transfer_buffer,
+		port->interrupt_in_urb->transfer_buffer_length,
+		cypress_read_int_callback, port,
+		port->interrupt_in_urb->interval);
+	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
+	if (result)
+		dev_err(&urb->dev->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
+	}
+	
+	return;
+} /* cypress_read_int_callback */
+
+
+static void cypress_write_int_callback(struct urb *urb, struct pt_regs *regs)
+{
+	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
+
+	/* free up the transfer buffer, as usb_free_urb() does not do this */
+	kfree (urb->transfer_buffer);
+
+	dbg("%s - port %d", __FUNCTION__, port->number);
+	
+	if (urb->status) {
+		dbg("%s - nonzero write status received: %d", __FUNCTION__, urb->status);
+		return;
+	}
+
+	schedule_work(&port->work);
+}
+
+
+/*****************************************************************************
+ * Module functions
+ *****************************************************************************/
+
+static int __init cypress_init(void)
+{
+	int retval;
+	
+	dbg("%s", __FUNCTION__);
+	
+	retval = usb_serial_register(&cypress_earthmate_device);
+	if (retval)
+		goto failed_em_register;
+	retval = usb_serial_register(&cypress_hidcom_device);
+	if (retval)
+		goto failed_hidcom_register;
+	retval = usb_register(&cypress_driver);
+	if (retval)
+		goto failed_usb_register;
+
+	info(DRIVER_DESC " " DRIVER_VERSION);
+	return 0;
+failed_usb_register:
+	usb_deregister(&cypress_driver);
+failed_hidcom_register:
+	usb_serial_deregister(&cypress_hidcom_device);
+failed_em_register:
+	usb_serial_deregister(&cypress_earthmate_device);
+
+	return retval;
+}
+
+
+static void __exit cypress_exit (void)
+{
+	dbg("%s", __FUNCTION__);
+
+	usb_deregister (&cypress_driver);
+	usb_serial_deregister (&cypress_earthmate_device);
+	usb_serial_deregister (&cypress_hidcom_device);
+}
+
+
+module_init(cypress_init);
+module_exit(cypress_exit);
+
+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");
+module_param(stats, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(stats, "Enable statistics or not");

drivers/usb/serial/cypress_m8.h

+#ifndef CYPRESS_M8_H
+#define CYPRESS_M8_H
+
+/* definitions and function prototypes used for the cypress USB to Serial controller */
+
+/* For sending our feature buffer - controlling serial communication states */
+/* Linux HID has no support for serial devices so we do this through the driver */
+#define HID_REQ_GET_REPORT 0x01
+#define HID_REQ_SET_REPORT 0x09
+
+/* List other cypress USB to Serial devices here, and add them to the id_table */
+
+/* DeLorme Earthmate USB - a GPS device */
+#define	VENDOR_ID_DELORME		 0x1163
+#define PRODUCT_ID_EARTHMATEUSB		 0x0100
+
+/* Cypress HID->COM RS232 Adapter */
+#define VENDOR_ID_CYPRESS		 0x04b4
+#define PRODUCT_ID_CYPHIDCOM		 0x5500
+/* End of device listing */
+
+/* Used for setting / requesting serial line settings */
+#define CYPRESS_SET_CONFIG 0x01
+#define CYPRESS_GET_CONFIG 0x02
+
+/* Used for throttle control */
+#define THROTTLED 0x1
+#define ACTUALLY_THROTTLED 0x2
+
+/* chiptypes - used in case firmware differs from the generic form ... offering
+ * 	different baud speeds/etc.
+ */
+
+#define CT_EARTHMATE	0x01
+#define CT_CYPHIDCOM	0x02
+#define CT_GENERIC	0x0F
+/* End of chiptype definitions */
+
+/* RS-232 serial data communication protocol definitions */
+/* these are sent / read at byte 0 of the input/output hid reports */
+/* You can find these values defined in the CY4601 USB to Serial design notes */
+
+#define CONTROL_DTR 	0x20	/* data terminal ready - flow control - host to device */
+#define UART_DSR	0x20	/* data set ready - flow control - device to host */
+#define CONTROL_RTS 	0x10	/* request to send - flow control - host to device */
+#define UART_CTS	0x10	/* clear to send - flow control - device to host */
+#define	UART_RI		0x10	/* ring indicator - modem - device to host */ 
+#define UART_CD		0x40	/* carrier detect - modem - device to host */
+#define CYP_ERROR 	0x08	/* received from input report - device to host */
+/* Note - the below has nothing to to with the "feature report" reset */
+#define CONTROL_RESET	0x08  	/* sent with output report - host to device */
+
+/* End of RS-232 protocol definitions */
+
+#endif /* CYPRESS_M8_H */