drivers/usb/serial/cp2101.c - LeafOS-Devices/android_kernel_samsung_universal7904 - Gitiles

 /*
  * Silicon Laboratories CP2101/CP2102 USB to RS232 serial adaptor driver
  *
  * Copyright (C) 2005 Craig Shelley (craig@microtron.org.uk)
  *
  *	This program is free software; you can redistribute it and/or
  *	modify it under the terms of the GNU General Public License version
  *	2 as published by the Free Software Foundation.
  *
  */

 #include <linux/config.h>
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/slab.h>
 #include <linux/tty.h>
 #include <linux/tty_flip.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/usb.h>
 #include <asm/uaccess.h>
 #include "usb-serial.h"

 /*
  * Version Information
  */
 #define DRIVER_VERSION "v0.03"
 #define DRIVER_DESC "Silicon Labs CP2101/CP2102 RS232 serial adaptor driver"

 /*
  * Function Prototypes
  */
 static int cp2101_open(struct usb_serial_port*, struct file*);
 static void cp2101_cleanup(struct usb_serial_port*);
 static void cp2101_close(struct usb_serial_port*, struct file*);
 static void cp2101_get_termios(struct usb_serial_port*);
 static void cp2101_set_termios(struct usb_serial_port*, struct termios*);
 static void cp2101_break_ctl(struct usb_serial_port*, int);
 static int cp2101_startup (struct usb_serial *);
 static void cp2101_shutdown(struct usb_serial*);


 static int debug;

 static struct usb_device_id id_table [] = {
 	{USB_DEVICE(0x10c4, 0xea60) },	/*Silicon labs factory default*/
 	{USB_DEVICE(0x10ab, 0x10c5) },	/*Siemens MC60 Cable*/
 	{ } /* Terminating Entry*/
 };

 MODULE_DEVICE_TABLE (usb, id_table);

 static struct usb_driver cp2101_driver = {
 	.owner		= THIS_MODULE,
 	.name		= "CP2101",
 	.probe		= usb_serial_probe,
 	.disconnect	= usb_serial_disconnect,
 	.id_table	= id_table,
 };

 static struct usb_serial_device_type cp2101_device = {
 	.owner			= THIS_MODULE,
 	.name			= "CP2101",
 	.id_table		= id_table,
 	.num_interrupt_in	= 0,
 	.num_bulk_in		= 0,
 	.num_bulk_out		= 0,
 	.num_ports		= 1,
 	.open			= cp2101_open,
 	.close			= cp2101_close,
 	.break_ctl		= cp2101_break_ctl,
 	.set_termios		= cp2101_set_termios,
 	.attach			= cp2101_startup,
 	.shutdown		= cp2101_shutdown,
 };

 /*Config request types*/
 #define REQTYPE_HOST_TO_DEVICE	0x41
 #define REQTYPE_DEVICE_TO_HOST	0xc1

 /*Config SET requests. To GET, add 1 to the request number*/
 #define CP2101_UART 		0x00	/*Enable / Disable*/
 #define CP2101_BAUDRATE		0x01	/*(BAUD_RATE_GEN_FREQ / baudrate)*/
 #define CP2101_BITS		0x03	/*0x(0)(data bits)(parity)(stop bits)*/
 #define CP2101_BREAK		0x05	/*On / Off*/
 #define CP2101_DTRRTS		0x07	/*101 / 202  ???*/
 #define CP2101_CONFIG_16	0x13	/*16 bytes of config data ???*/
 #define CP2101_CONFIG_6		0x19	/*6 bytes of config data ???*/

 /*CP2101_UART*/
 #define UART_ENABLE		0x0001
 #define UART_DISABLE		0x0000

 /*CP2101_BAUDRATE*/
 #define BAUD_RATE_GEN_FREQ	0x384000

 /*CP2101_BITS*/
 #define BITS_DATA_MASK		0X0f00
 #define BITS_DATA_6		0X0600
 #define BITS_DATA_7		0X0700
 #define BITS_DATA_8		0X0800
 #define BITS_DATA_9		0X0900

 #define BITS_PARITY_MASK	0x00f0
 #define BITS_PARITY_NONE	0x0000
 #define BITS_PARITY_ODD		0x0010
 #define BITS_PARITY_EVEN	0x0020
 #define BITS_PARITY_MARK	0x0030
 #define BITS_PARITY_SPACE	0x0040

 #define BITS_STOP_MASK		0x000f
 #define BITS_STOP_1		0x0000
 #define BITS_STOP_1_5		0x0001
 #define BITS_STOP_2		0x0002
 #define BREAK_ON		0x0000
 #define BREAK_OFF		0x0001


 static int cp2101_get_config(struct usb_serial_port* port, u8 request)
 {
 	struct usb_serial *serial = port->serial;
 	unsigned char buf[4];
 	unsigned int value;
 	int result, i;

 	/*For get requests, the request number must be incremented*/
 	request++;

 	/*Issue the request, attempting to read 4 bytes*/
 	result = usb_control_msg (serial->dev,usb_rcvctrlpipe (serial->dev, 0),
 				request, REQTYPE_DEVICE_TO_HOST, 0x0000,
 				0, buf, 4, 300);

 	if (result < 0) {
 		dev_err(&port->dev, "%s - Unable to send config request, "
 				"request=0x%x result=%d\n",
 				__FUNCTION__, request, result);
 		return result;
 	}

 	/*Assemble each byte read into an integer value*/
 	value = 0;
 	for (i=0; i<4 && i<result; i++)
 		value |= (buf[i] << (i * 8));

 	dbg( " %s - request=0x%x result=%d value=0x%x",
 			__FUNCTION__, request, result, value);

 	return value;
 }

 static int cp2101_set_config(struct usb_serial_port* port, u8 request, u16 value)
 {
 	struct usb_serial *serial = port->serial;
 	int result;
 	result = usb_control_msg (serial->dev, usb_sndctrlpipe(serial->dev, 0),
 			request, REQTYPE_HOST_TO_DEVICE, value,
 			0, NULL, 0, 300);

 	if (result <0) {
 		dev_err(&port->dev, "%s - Unable to send config request, "
 				"request=0x%x value=0x%x result=%d\n",
 				__FUNCTION__, request, value, result);
 		return result;
 	}

 	dbg(" %s - request=0x%x value=0x%x result=%d",
 			__FUNCTION__, request, value, result);

 	return 0;
 }

 static int cp2101_open (struct usb_serial_port *port, struct file *filp)
 {
 	struct usb_serial *serial = port->serial;
 	int result;

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

 	if (cp2101_set_config(port, CP2101_UART, UART_ENABLE)) {
 		dev_err(&port->dev, "%s - Unable to enable UART\n",
 				__FUNCTION__);
 		return -EPROTO;
 	}

 	/* Start reading from the device */
 	usb_fill_bulk_urb (port->read_urb, serial->dev,
 			usb_rcvbulkpipe(serial->dev,
 			port->bulk_in_endpointAddress),
 			port->read_urb->transfer_buffer,
 			port->read_urb->transfer_buffer_length,
 			serial->type->read_bulk_callback,
 			port);
 	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
 	if (result) {
 		dev_err(&port->dev, "%s - failed resubmitting read urb, "
 				"error %d\n", __FUNCTION__, result);
 		return result;
 	}

 	/*Configure the termios structure*/
 	cp2101_get_termios(port);

 	return 0;
 }

 static void cp2101_cleanup (struct usb_serial_port *port)
 {
 	struct usb_serial *serial = port->serial;

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

 	if (serial->dev) {
 		/* shutdown any bulk reads that might be going on */
 		if (serial->num_bulk_out)
 			usb_kill_urb(port->write_urb);
 		if (serial->num_bulk_in)
 			usb_kill_urb(port->read_urb);
 	}
 }

 static void cp2101_close (struct usb_serial_port *port, struct file * filp)
 {
 	dbg("%s - port %d", __FUNCTION__, port->number);

 	/* shutdown our urbs */
 	dbg("%s - shutting down urbs", __FUNCTION__);
 	usb_kill_urb(port->write_urb);
 	usb_kill_urb(port->read_urb);

 	cp2101_set_config(port, CP2101_UART, UART_DISABLE);
 }

 /* cp2101_get_termios*/
 /* Reads the baud rate, data bits, parity and stop bits from the device*/
 /* Corrects any unsupported values*/
 /* Configures the termios structure to reflect the state of the device*/
 static void cp2101_get_termios (struct usb_serial_port *port)
 {
 	unsigned int cflag;
 	int baud;
 	int bits;

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

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

 	baud = cp2101_get_config(port, CP2101_BAUDRATE);
 	/*Convert to baudrate*/
 	if (baud)
 		baud = BAUD_RATE_GEN_FREQ / baud;

 	dbg("%s - baud rate = %d", __FUNCTION__, baud);
 	cflag &= ~CBAUD;
 	switch (baud) {
 		/* The baud rates which are commented out below
 		 * appear to be supported by the device
 		 * but are non-standard
 		 */
 		case 600:	cflag |= B600;		break;
 		case 1200:	cflag |= B1200;		break;
 		case 1800:	cflag |= B1800;		break;
 		case 2400:	cflag |= B2400;		break;
 		case 4800:	cflag |= B4800;		break;
 		/*case 7200:	cflag |= B7200;		break;*/
 		case 9600:	cflag |= B9600;		break;
 		/*case 14400:	cflag |= B14400;	break;*/
 		case 19200:	cflag |= B19200;	break;
 		/*case 28800:	cflag |= B28800;	break;*/
 		case 38400:	cflag |= B38400;	break;
 		/*case 55854:	cflag |= B55054;	break;*/
 		case 57600:	cflag |= B57600;	break;
 		case 115200:	cflag |= B115200;	break;
 		/*case 127117:	cflag |= B127117;	break;*/
 		case 230400:	cflag |= B230400;	break;
 		case 460800:	cflag |= B460800;	break;
 		case 921600:	cflag |= B921600;	break;
 		/*case 3686400:	cflag |= B3686400;	break;*/
 		default:
 			dbg("%s - Baud rate is not supported, "
 					"using 9600 baud", __FUNCTION__);
 			cflag |= B9600;
 			cp2101_set_config(port, CP2101_BAUDRATE,
 					(BAUD_RATE_GEN_FREQ/9600));
 			break;
 	}

 	bits = cp2101_get_config(port, CP2101_BITS);
 	cflag &= ~CSIZE;
 	switch(bits & BITS_DATA_MASK) {
 		case BITS_DATA_6:
 			dbg("%s - data bits = 6", __FUNCTION__);
 			cflag |= CS6;
 			break;
 		case BITS_DATA_7:
 			dbg("%s - data bits = 7", __FUNCTION__);
 			cflag |= CS7;
 			break;
 		case BITS_DATA_8:
 			dbg("%s - data bits = 8", __FUNCTION__);
 			cflag |= CS8;
 			break;
 		case BITS_DATA_9:
 			dbg("%s - data bits = 9 (not supported, "
 					"using 8 data bits)", __FUNCTION__);
 			cflag |= CS8;
 			bits &= ~BITS_DATA_MASK;
 			bits |= BITS_DATA_8;
 			cp2101_set_config(port, CP2101_BITS, bits);
 			break;
 		default:
 			dbg("%s - Unknown number of data bits, "
 					"using 8", __FUNCTION__);
 			cflag |= CS8;
 			bits &= ~BITS_DATA_MASK;
 			bits |= BITS_DATA_8;
 			cp2101_set_config(port, CP2101_BITS, bits);
 			break;
 	}

 	switch(bits & BITS_PARITY_MASK) {
 		case BITS_PARITY_NONE:
 			dbg("%s - parity = NONE", __FUNCTION__);
 			cflag &= ~PARENB;
 			break;
 		case BITS_PARITY_ODD:
 			dbg("%s - parity = ODD", __FUNCTION__);
 			cflag |= (PARENB|PARODD);
 			break;
 		case BITS_PARITY_EVEN:
 			dbg("%s - parity = EVEN", __FUNCTION__);
 			cflag &= ~PARODD;
 			cflag |= PARENB;
 			break;
 		case BITS_PARITY_MARK:
 			dbg("%s - parity = MARK (not supported, "
 					"disabling parity)", __FUNCTION__);
 			cflag &= ~PARENB;
 			bits &= ~BITS_PARITY_MASK;
 			cp2101_set_config(port, CP2101_BITS, bits);
 			break;
 		case BITS_PARITY_SPACE:
 			dbg("%s - parity = SPACE (not supported, "
 					"disabling parity)", __FUNCTION__);
 			cflag &= ~PARENB;
 			bits &= ~BITS_PARITY_MASK;
 			cp2101_set_config(port, CP2101_BITS, bits);
 			break;
 		default:
 			dbg("%s - Unknown parity mode, "
 					"disabling parity", __FUNCTION__);
 			cflag &= ~PARENB;
 			bits &= ~BITS_PARITY_MASK;
 			cp2101_set_config(port, CP2101_BITS, bits);
 			break;
 	}

 	cflag &= ~CSTOPB;
 	switch(bits & BITS_STOP_MASK) {
 		case BITS_STOP_1:
 			dbg("%s - stop bits = 1", __FUNCTION__);
 			break;
 		case BITS_STOP_1_5:
 			dbg("%s - stop bits = 1.5 (not supported, "
 					"using 1 stop bit", __FUNCTION__);
 			bits &= ~BITS_STOP_MASK;
 			cp2101_set_config(port, CP2101_BITS, bits);
 			break;
 		case BITS_STOP_2:
 			dbg("%s - stop bits = 2", __FUNCTION__);
 			cflag |= CSTOPB;
 			break;
 		default:
 			dbg("%s - Unknown number of stop bits, "
 					"using 1 stop bit", __FUNCTION__);
 			bits &= ~BITS_STOP_MASK;
 			cp2101_set_config(port, CP2101_BITS, bits);
 			break;
 	}

 	port->tty->termios->c_cflag = cflag;
 }

 static void cp2101_set_termios (struct usb_serial_port *port,
 		struct termios *old_termios)
 {
 	unsigned int cflag, old_cflag=0;
 	int baud=0;
 	int bits;

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

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

 	/* check that they really want us to change something */
 	if (old_termios) {
 		if ((cflag == old_termios->c_cflag) &&
 				(RELEVANT_IFLAG(port->tty->termios->c_iflag)
 				== RELEVANT_IFLAG(old_termios->c_iflag))) {
 			dbg("%s - nothing to change...", __FUNCTION__);
 			return;
 		}

 		old_cflag = old_termios->c_cflag;
 	}

 	/* If the baud rate is to be updated*/
 	if ((cflag & CBAUD) != (old_cflag & CBAUD)) {
 		switch (cflag & CBAUD) {
 			/* The baud rates which are commented out below
 			 * appear to be supported by the device
 			 * but are non-standard
 			 */
 			case B0:	baud = 0;	break;
 			case B600:	baud = 600;	break;
 			case B1200:	baud = 1200;	break;
 			case B1800:	baud = 1800;	break;
 			case B2400:	baud = 2400;	break;
 			case B4800:	baud = 4800;	break;
 			/*case B7200:	baud = 7200;	break;*/
 			case B9600:	baud = 9600;	break;
 			/*ase B14400:	baud = 14400;	break;*/
 			case B19200:	baud = 19200;	break;
 			/*case B28800:	baud = 28800;	break;*/
 			case B38400:	baud = 38400;	break;
 			/*case B55854:	baud = 55054;	break;*/
 			case B57600:	baud = 57600;	break;
 			case B115200:	baud = 115200;	break;
 			/*case B127117:	baud = 127117;	break;*/
 			case B230400:	baud = 230400;	break;
 			case B460800:	baud = 460800;	break;
 			case B921600:	baud = 921600;	break;
 			/*case B3686400:	baud = 3686400;	break;*/
 			default:
 				dev_err(&port->dev, "cp2101 driver does not "
 					"support the baudrate requested\n");
 				break;
 		}

 		if (baud) {
 			dbg("%s - Setting baud rate to %d baud", __FUNCTION__,
 					baud);
 			if (cp2101_set_config(port, CP2101_BAUDRATE,
 						(BAUD_RATE_GEN_FREQ / baud)))
 				dev_err(&port->dev, "Baud rate requested not "
 						"supported by device\n");
 		}
 	}

 	/*If the number of data bits is to be updated*/
 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
 		bits = cp2101_get_config(port, CP2101_BITS);
 		bits &= ~BITS_DATA_MASK;
 		switch (cflag & CSIZE) {
 			case CS6:
 				bits |= BITS_DATA_6;
 				dbg("%s - data bits = 6", __FUNCTION__);
 				break;
 			case CS7:
 				bits |= BITS_DATA_7;
 				dbg("%s - data bits = 7", __FUNCTION__);
 				break;
 			case CS8:
 				bits |= BITS_DATA_8;
 				dbg("%s - data bits = 8", __FUNCTION__);
 				break;
 			/*case CS9:
 			 	bits |= BITS_DATA_9;
 				dbg("%s - data bits = 9", __FUNCTION__);
 				break;*/
 			default:
 				dev_err(&port->dev, "cp2101 driver does not "
 					"support the number of bits requested,"
 					" using 8 bit mode\n");
 				bits |= BITS_DATA_8;
 				break;
 		}
 		if (cp2101_set_config(port, CP2101_BITS, bits))
 			dev_err(&port->dev, "Number of data bits requested "
 					"not supported by device\n");
 	}

 	if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))) {
 		bits = cp2101_get_config(port, CP2101_BITS);
 		bits &= ~BITS_PARITY_MASK;
 		if (cflag & PARENB) {
 			if (cflag & PARODD) {
 				bits |= BITS_PARITY_ODD;
 				dbg("%s - parity = ODD", __FUNCTION__);
 			} else {
 				bits |= BITS_PARITY_EVEN;
 				dbg("%s - parity = EVEN", __FUNCTION__);
 			}
 		}
 		if (cp2101_set_config(port, CP2101_BITS, bits))
 			dev_err(&port->dev, "Parity mode not supported "
 					"by device\n");
 	}

 	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
 		bits = cp2101_get_config(port, CP2101_BITS);
 		bits &= ~BITS_STOP_MASK;
 		if (cflag & CSTOPB) {
 			bits |= BITS_STOP_2;
 			dbg("%s - stop bits = 2", __FUNCTION__);
 		} else {
 			bits |= BITS_STOP_1;
 			dbg("%s - stop bits = 1", __FUNCTION__);
 		}
 		if (cp2101_set_config(port, CP2101_BITS, bits))
 			dev_err(&port->dev, "Number of stop bits requested "
 					"not supported by device\n");
 	}
 }

 static void cp2101_break_ctl (struct usb_serial_port *port, int break_state)
 {
 	u16 state;

 	dbg("%s - port %d", __FUNCTION__, port->number);
 	if (break_state == 0)
 		state = BREAK_OFF;
 	else
 		state = BREAK_ON;
 	dbg("%s - turning break %s", __FUNCTION__,
 			state==BREAK_OFF ? "off" : "on");
 	cp2101_set_config(port, CP2101_BREAK, state);
 }

 static int cp2101_startup (struct usb_serial *serial)
 {
 	/*CP2101 buffers behave strangely unless device is reset*/
 	usb_reset_device(serial->dev);
 	return 0;
 }

 static void cp2101_shutdown (struct usb_serial *serial)
 {
 	int i;

 	dbg("%s", __FUNCTION__);

 	/* stop reads and writes on all ports */
 	for (i=0; i < serial->num_ports; ++i) {
 		cp2101_cleanup(serial->port[i]);
 	}
 }

 static int __init cp2101_init (void)
 {
 	int retval;

 	retval = usb_serial_register(&cp2101_device);
 	if (retval)
 		return retval; /*Failed to register*/

 	retval = usb_register(&cp2101_driver);
 	if (retval) {
 		/*Failed to register*/
 		usb_serial_deregister(&cp2101_device);
 		return retval;
 	}

 	/*Success*/
 	info(DRIVER_DESC " " DRIVER_VERSION);
 	return 0;
 }

 static void __exit cp2101_exit (void)
 {
 	usb_deregister (&cp2101_driver);
 	usb_serial_deregister (&cp2101_device);
 }

 module_init(cp2101_init);
 module_exit(cp2101_exit);

 MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_VERSION(DRIVER_VERSION);
 MODULE_LICENSE("GPL");

 module_param(debug, bool, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(debug, "Enable verbose debugging messages");
	/*
	* Silicon Laboratories CP2101/CP2102 USB to RS232 serial adaptor driver
	*
	* Copyright (C) 2005 Craig Shelley (craig@microtron.org.uk)
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License version
	* 2 as published by the Free Software Foundation.
	*
	*/

	#include <linux/config.h>
	#include <linux/kernel.h>
	#include <linux/errno.h>
	#include <linux/slab.h>
	#include <linux/tty.h>
	#include <linux/tty_flip.h>
	#include <linux/module.h>
	#include <linux/moduleparam.h>
	#include <linux/usb.h>
	#include <asm/uaccess.h>
	#include "usb-serial.h"

	/*
	* Version Information
	*/
	#define DRIVER_VERSION "v0.03"
	#define DRIVER_DESC "Silicon Labs CP2101/CP2102 RS232 serial adaptor driver"

	/*
	* Function Prototypes
	*/
	static int cp2101_open(struct usb_serial_port, struct file);
	static void cp2101_cleanup(struct usb_serial_port*);
	static void cp2101_close(struct usb_serial_port, struct file);
	static void cp2101_get_termios(struct usb_serial_port*);
	static void cp2101_set_termios(struct usb_serial_port, struct termios);
	static void cp2101_break_ctl(struct usb_serial_port*, int);
	static int cp2101_startup (struct usb_serial *);
	static void cp2101_shutdown(struct usb_serial*);


	static int debug;

	static struct usb_device_id id_table [] = {
	{USB_DEVICE(0x10c4, 0xea60) }, /Silicon labs factory default/
	{USB_DEVICE(0x10ab, 0x10c5) }, /Siemens MC60 Cable/
	{ } /* Terminating Entry*/
	};

	MODULE_DEVICE_TABLE (usb, id_table);

	static struct usb_driver cp2101_driver = {
	.owner = THIS_MODULE,
	.name = "CP2101",
	.probe = usb_serial_probe,
	.disconnect = usb_serial_disconnect,
	.id_table = id_table,
	};

	static struct usb_serial_device_type cp2101_device = {
	.owner = THIS_MODULE,
	.name = "CP2101",
	.id_table = id_table,
	.num_interrupt_in = 0,
	.num_bulk_in = 0,
	.num_bulk_out = 0,
	.num_ports = 1,
	.open = cp2101_open,
	.close = cp2101_close,
	.break_ctl = cp2101_break_ctl,
	.set_termios = cp2101_set_termios,
	.attach = cp2101_startup,
	.shutdown = cp2101_shutdown,
	};

	/Config request types/
	#define REQTYPE_HOST_TO_DEVICE 0x41
	#define REQTYPE_DEVICE_TO_HOST 0xc1

	/Config SET requests. To GET, add 1 to the request number/
	#define CP2101_UART 0x00 /Enable / Disable/
	#define CP2101_BAUDRATE 0x01 /(BAUD_RATE_GEN_FREQ / baudrate)/
	#define CP2101_BITS 0x03 /0x(0)(data bits)(parity)(stop bits)/
	#define CP2101_BREAK 0x05 /On / Off/
	#define CP2101_DTRRTS 0x07 /101 / 202 ???/
	#define CP2101_CONFIG_16 0x13 /16 bytes of config data ???/
	#define CP2101_CONFIG_6 0x19 /6 bytes of config data ???/

	/CP2101_UART/
	#define UART_ENABLE 0x0001
	#define UART_DISABLE 0x0000

	/CP2101_BAUDRATE/
	#define BAUD_RATE_GEN_FREQ 0x384000

	/CP2101_BITS/
	#define BITS_DATA_MASK 0X0f00
	#define BITS_DATA_6 0X0600
	#define BITS_DATA_7 0X0700
	#define BITS_DATA_8 0X0800
	#define BITS_DATA_9 0X0900

	#define BITS_PARITY_MASK 0x00f0
	#define BITS_PARITY_NONE 0x0000
	#define BITS_PARITY_ODD 0x0010
	#define BITS_PARITY_EVEN 0x0020
	#define BITS_PARITY_MARK 0x0030
	#define BITS_PARITY_SPACE 0x0040

	#define BITS_STOP_MASK 0x000f
	#define BITS_STOP_1 0x0000
	#define BITS_STOP_1_5 0x0001
	#define BITS_STOP_2 0x0002
	#define BREAK_ON 0x0000
	#define BREAK_OFF 0x0001


	static int cp2101_get_config(struct usb_serial_port* port, u8 request)
	{
	struct usb_serial *serial = port->serial;
	unsigned char buf[4];
	unsigned int value;
	int result, i;

	/For get requests, the request number must be incremented/
	request++;

	/Issue the request, attempting to read 4 bytes/
	result = usb_control_msg (serial->dev,usb_rcvctrlpipe (serial->dev, 0),
	request, REQTYPE_DEVICE_TO_HOST, 0x0000,
	0, buf, 4, 300);

	if (result < 0) {
	dev_err(&port->dev, "%s - Unable to send config request, "
	"request=0x%x result=%d\n",
	__FUNCTION__, request, result);
	return result;
	}

	/Assemble each byte read into an integer value/
	value = 0;
	for (i=0; i<4 && i<result; i++)
	value \|= (buf[i] << (i * 8));

	dbg( " %s - request=0x%x result=%d value=0x%x",
	__FUNCTION__, request, result, value);

	return value;
	}

	static int cp2101_set_config(struct usb_serial_port* port, u8 request, u16 value)
	{
	struct usb_serial *serial = port->serial;
	int result;
	result = usb_control_msg (serial->dev, usb_sndctrlpipe(serial->dev, 0),
	request, REQTYPE_HOST_TO_DEVICE, value,
	0, NULL, 0, 300);

	if (result <0) {
	dev_err(&port->dev, "%s - Unable to send config request, "
	"request=0x%x value=0x%x result=%d\n",
	__FUNCTION__, request, value, result);
	return result;
	}

	dbg(" %s - request=0x%x value=0x%x result=%d",
	__FUNCTION__, request, value, result);

	return 0;
	}

	static int cp2101_open (struct usb_serial_port port, struct file filp)
	{
	struct usb_serial *serial = port->serial;
	int result;

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

	if (cp2101_set_config(port, CP2101_UART, UART_ENABLE)) {
	dev_err(&port->dev, "%s - Unable to enable UART\n",
	__FUNCTION__);
	return -EPROTO;
	}

	/* Start reading from the device */
	usb_fill_bulk_urb (port->read_urb, serial->dev,
	usb_rcvbulkpipe(serial->dev,
	port->bulk_in_endpointAddress),
	port->read_urb->transfer_buffer,
	port->read_urb->transfer_buffer_length,
	serial->type->read_bulk_callback,
	port);
	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
	if (result) {
	dev_err(&port->dev, "%s - failed resubmitting read urb, "
	"error %d\n", __FUNCTION__, result);
	return result;
	}

	/Configure the termios structure/
	cp2101_get_termios(port);

	return 0;
	}

	static void cp2101_cleanup (struct usb_serial_port *port)
	{
	struct usb_serial *serial = port->serial;

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

	if (serial->dev) {
	/* shutdown any bulk reads that might be going on */
	if (serial->num_bulk_out)
	usb_kill_urb(port->write_urb);
	if (serial->num_bulk_in)
	usb_kill_urb(port->read_urb);
	}
	}

	static void cp2101_close (struct usb_serial_port port, struct file filp)
	{
	dbg("%s - port %d", __FUNCTION__, port->number);

	/* shutdown our urbs */
	dbg("%s - shutting down urbs", __FUNCTION__);
	usb_kill_urb(port->write_urb);
	usb_kill_urb(port->read_urb);

	cp2101_set_config(port, CP2101_UART, UART_DISABLE);
	}

	/* cp2101_get_termios*/
	/* Reads the baud rate, data bits, parity and stop bits from the device*/
	/* Corrects any unsupported values*/
	/* Configures the termios structure to reflect the state of the device*/
	static void cp2101_get_termios (struct usb_serial_port *port)
	{
	unsigned int cflag;
	int baud;
	int bits;

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

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

	baud = cp2101_get_config(port, CP2101_BAUDRATE);
	/Convert to baudrate/
	if (baud)
	baud = BAUD_RATE_GEN_FREQ / baud;

	dbg("%s - baud rate = %d", __FUNCTION__, baud);
	cflag &= ~CBAUD;
	switch (baud) {
	/* The baud rates which are commented out below
	* appear to be supported by the device
	* but are non-standard
	*/
	case 600: cflag \|= B600; break;
	case 1200: cflag \|= B1200; break;
	case 1800: cflag \|= B1800; break;
	case 2400: cflag \|= B2400; break;
	case 4800: cflag \|= B4800; break;
	/case 7200: cflag \|= B7200; break;/
	case 9600: cflag \|= B9600; break;
	/case 14400: cflag \|= B14400; break;/
	case 19200: cflag \|= B19200; break;
	/case 28800: cflag \|= B28800; break;/
	case 38400: cflag \|= B38400; break;
	/case 55854: cflag \|= B55054; break;/
	case 57600: cflag \|= B57600; break;
	case 115200: cflag \|= B115200; break;
	/case 127117: cflag \|= B127117; break;/
	case 230400: cflag \|= B230400; break;
	case 460800: cflag \|= B460800; break;
	case 921600: cflag \|= B921600; break;
	/case 3686400: cflag \|= B3686400; break;/
	default:
	dbg("%s - Baud rate is not supported, "
	"using 9600 baud", __FUNCTION__);
	cflag \|= B9600;
	cp2101_set_config(port, CP2101_BAUDRATE,
	(BAUD_RATE_GEN_FREQ/9600));
	break;
	}

	bits = cp2101_get_config(port, CP2101_BITS);
	cflag &= ~CSIZE;
	switch(bits & BITS_DATA_MASK) {
	case BITS_DATA_6:
	dbg("%s - data bits = 6", __FUNCTION__);
	cflag \|= CS6;
	break;
	case BITS_DATA_7:
	dbg("%s - data bits = 7", __FUNCTION__);
	cflag \|= CS7;
	break;
	case BITS_DATA_8:
	dbg("%s - data bits = 8", __FUNCTION__);
	cflag \|= CS8;
	break;
	case BITS_DATA_9:
	dbg("%s - data bits = 9 (not supported, "
	"using 8 data bits)", __FUNCTION__);
	cflag \|= CS8;
	bits &= ~BITS_DATA_MASK;
	bits \|= BITS_DATA_8;
	cp2101_set_config(port, CP2101_BITS, bits);
	break;
	default:
	dbg("%s - Unknown number of data bits, "
	"using 8", __FUNCTION__);
	cflag \|= CS8;
	bits &= ~BITS_DATA_MASK;
	bits \|= BITS_DATA_8;
	cp2101_set_config(port, CP2101_BITS, bits);
	break;
	}

	switch(bits & BITS_PARITY_MASK) {
	case BITS_PARITY_NONE:
	dbg("%s - parity = NONE", __FUNCTION__);
	cflag &= ~PARENB;
	break;
	case BITS_PARITY_ODD:
	dbg("%s - parity = ODD", __FUNCTION__);
	cflag \|= (PARENB\|PARODD);
	break;
	case BITS_PARITY_EVEN:
	dbg("%s - parity = EVEN", __FUNCTION__);
	cflag &= ~PARODD;
	cflag \|= PARENB;
	break;
	case BITS_PARITY_MARK:
	dbg("%s - parity = MARK (not supported, "
	"disabling parity)", __FUNCTION__);
	cflag &= ~PARENB;
	bits &= ~BITS_PARITY_MASK;
	cp2101_set_config(port, CP2101_BITS, bits);
	break;
	case BITS_PARITY_SPACE:
	dbg("%s - parity = SPACE (not supported, "
	"disabling parity)", __FUNCTION__);
	cflag &= ~PARENB;
	bits &= ~BITS_PARITY_MASK;
	cp2101_set_config(port, CP2101_BITS, bits);
	break;
	default:
	dbg("%s - Unknown parity mode, "
	"disabling parity", __FUNCTION__);
	cflag &= ~PARENB;
	bits &= ~BITS_PARITY_MASK;
	cp2101_set_config(port, CP2101_BITS, bits);
	break;
	}

	cflag &= ~CSTOPB;
	switch(bits & BITS_STOP_MASK) {
	case BITS_STOP_1:
	dbg("%s - stop bits = 1", __FUNCTION__);
	break;
	case BITS_STOP_1_5:
	dbg("%s - stop bits = 1.5 (not supported, "
	"using 1 stop bit", __FUNCTION__);
	bits &= ~BITS_STOP_MASK;
	cp2101_set_config(port, CP2101_BITS, bits);
	break;
	case BITS_STOP_2:
	dbg("%s - stop bits = 2", __FUNCTION__);
	cflag \|= CSTOPB;
	break;
	default:
	dbg("%s - Unknown number of stop bits, "
	"using 1 stop bit", __FUNCTION__);
	bits &= ~BITS_STOP_MASK;
	cp2101_set_config(port, CP2101_BITS, bits);
	break;
	}

	port->tty->termios->c_cflag = cflag;
	}

	static void cp2101_set_termios (struct usb_serial_port *port,
	struct termios *old_termios)
	{
	unsigned int cflag, old_cflag=0;
	int baud=0;
	int bits;

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

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

	/* check that they really want us to change something */
	if (old_termios) {
	if ((cflag == old_termios->c_cflag) &&
	(RELEVANT_IFLAG(port->tty->termios->c_iflag)
	== RELEVANT_IFLAG(old_termios->c_iflag))) {
	dbg("%s - nothing to change...", __FUNCTION__);
	return;
	}

	old_cflag = old_termios->c_cflag;
	}

	/* If the baud rate is to be updated*/
	if ((cflag & CBAUD) != (old_cflag & CBAUD)) {
	switch (cflag & CBAUD) {
	/* The baud rates which are commented out below
	* appear to be supported by the device
	* but are non-standard
	*/
	case B0: baud = 0; break;
	case B600: baud = 600; break;
	case B1200: baud = 1200; break;
	case B1800: baud = 1800; break;
	case B2400: baud = 2400; break;
	case B4800: baud = 4800; break;
	/case B7200: baud = 7200; break;/
	case B9600: baud = 9600; break;
	/ase B14400: baud = 14400; break;/
	case B19200: baud = 19200; break;
	/case B28800: baud = 28800; break;/
	case B38400: baud = 38400; break;
	/case B55854: baud = 55054; break;/
	case B57600: baud = 57600; break;
	case B115200: baud = 115200; break;
	/case B127117: baud = 127117; break;/
	case B230400: baud = 230400; break;
	case B460800: baud = 460800; break;
	case B921600: baud = 921600; break;
	/case B3686400: baud = 3686400; break;/
	default:
	dev_err(&port->dev, "cp2101 driver does not "
	"support the baudrate requested\n");
	break;
	}

	if (baud) {
	dbg("%s - Setting baud rate to %d baud", __FUNCTION__,
	baud);
	if (cp2101_set_config(port, CP2101_BAUDRATE,
	(BAUD_RATE_GEN_FREQ / baud)))
	dev_err(&port->dev, "Baud rate requested not "
	"supported by device\n");
	}
	}

	/If the number of data bits is to be updated/
	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
	bits = cp2101_get_config(port, CP2101_BITS);
	bits &= ~BITS_DATA_MASK;
	switch (cflag & CSIZE) {
	case CS6:
	bits \|= BITS_DATA_6;
	dbg("%s - data bits = 6", __FUNCTION__);
	break;
	case CS7:
	bits \|= BITS_DATA_7;
	dbg("%s - data bits = 7", __FUNCTION__);
	break;
	case CS8:
	bits \|= BITS_DATA_8;
	dbg("%s - data bits = 8", __FUNCTION__);
	break;
	/*case CS9:
	bits \|= BITS_DATA_9;
	dbg("%s - data bits = 9", __FUNCTION__);
	break;*/
	default:
	dev_err(&port->dev, "cp2101 driver does not "
	"support the number of bits requested,"
	" using 8 bit mode\n");
	bits \|= BITS_DATA_8;
	break;
	}
	if (cp2101_set_config(port, CP2101_BITS, bits))
	dev_err(&port->dev, "Number of data bits requested "
	"not supported by device\n");
	}

	if ((cflag & (PARENB\|PARODD)) != (old_cflag & (PARENB\|PARODD))) {
	bits = cp2101_get_config(port, CP2101_BITS);
	bits &= ~BITS_PARITY_MASK;
	if (cflag & PARENB) {
	if (cflag & PARODD) {
	bits \|= BITS_PARITY_ODD;
	dbg("%s - parity = ODD", __FUNCTION__);
	} else {
	bits \|= BITS_PARITY_EVEN;
	dbg("%s - parity = EVEN", __FUNCTION__);
	}
	}
	if (cp2101_set_config(port, CP2101_BITS, bits))
	dev_err(&port->dev, "Parity mode not supported "
	"by device\n");
	}

	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
	bits = cp2101_get_config(port, CP2101_BITS);
	bits &= ~BITS_STOP_MASK;
	if (cflag & CSTOPB) {
	bits \|= BITS_STOP_2;
	dbg("%s - stop bits = 2", __FUNCTION__);
	} else {
	bits \|= BITS_STOP_1;
	dbg("%s - stop bits = 1", __FUNCTION__);
	}
	if (cp2101_set_config(port, CP2101_BITS, bits))
	dev_err(&port->dev, "Number of stop bits requested "
	"not supported by device\n");
	}
	}

	static void cp2101_break_ctl (struct usb_serial_port *port, int break_state)
	{
	u16 state;

	dbg("%s - port %d", __FUNCTION__, port->number);
	if (break_state == 0)
	state = BREAK_OFF;
	else
	state = BREAK_ON;
	dbg("%s - turning break %s", __FUNCTION__,
	state==BREAK_OFF ? "off" : "on");
	cp2101_set_config(port, CP2101_BREAK, state);
	}

	static int cp2101_startup (struct usb_serial *serial)
	{
	/CP2101 buffers behave strangely unless device is reset/
	usb_reset_device(serial->dev);
	return 0;
	}

	static void cp2101_shutdown (struct usb_serial *serial)
	{
	int i;

	dbg("%s", __FUNCTION__);

	/* stop reads and writes on all ports */
	for (i=0; i < serial->num_ports; ++i) {
	cp2101_cleanup(serial->port[i]);
	}
	}

	static int __init cp2101_init (void)
	{
	int retval;

	retval = usb_serial_register(&cp2101_device);
	if (retval)
	return retval; /Failed to register/

	retval = usb_register(&cp2101_driver);
	if (retval) {
	/Failed to register/
	usb_serial_deregister(&cp2101_device);
	return retval;
	}

	/Success/
	info(DRIVER_DESC " " DRIVER_VERSION);
	return 0;
	}

	static void __exit cp2101_exit (void)
	{
	usb_deregister (&cp2101_driver);
	usb_serial_deregister (&cp2101_device);
	}

	module_init(cp2101_init);
	module_exit(cp2101_exit);

	MODULE_DESCRIPTION(DRIVER_DESC);
	MODULE_VERSION(DRIVER_VERSION);
	MODULE_LICENSE("GPL");

	module_param(debug, bool, S_IRUGO \| S_IWUSR);
	MODULE_PARM_DESC(debug, "Enable verbose debugging messages");