drivers/usb/serial/ark3116.c - arm/linux-arm64-legacy - Git at Google

 /*
  * Copyright (C) 2006
  *   Simon Schulz (ark3116_driver <at> auctionant.de)
  *
  * ark3116
  * - implements a driver for the arkmicro ark3116 chipset (vendor=0x6547,
  *   productid=0x0232) (used in a datacable called KQ-U8A)
  *
  * - based on code by krisfx -> thanks !!
  *   (see http://www.linuxquestions.org/questions/showthread.php?p=2184457#post2184457)
  *
  *  - based on logs created by usbsnoopy
  *
  * 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.
  */

 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/tty.h>
 #include <linux/module.h>
 #include <linux/usb.h>
 #include <linux/usb/serial.h>
 #include <linux/serial.h>
 #include <linux/uaccess.h>


 static int debug;

 static struct usb_device_id id_table [] = {
 	{ USB_DEVICE(0x6547, 0x0232) },
 	{ },
 };
 MODULE_DEVICE_TABLE(usb, id_table);

 static inline void ARK3116_SND(struct usb_serial *serial, int seq,
 			       __u8 request, __u8 requesttype,
 			       __u16 value, __u16 index)
 {
 	int result;
 	result = usb_control_msg(serial->dev,
 				 usb_sndctrlpipe(serial->dev, 0),
 				 request, requesttype, value, index,
 				 NULL, 0x00, 1000);
 	dbg("%03d > ok", seq);
 }

 static inline void ARK3116_RCV(struct usb_serial *serial, int seq,
 			       __u8 request, __u8 requesttype,
 			       __u16 value, __u16 index, __u8 expected,
 			       char *buf)
 {
 	int result;
 	result = usb_control_msg(serial->dev,
 				 usb_rcvctrlpipe(serial->dev, 0),
 				 request, requesttype, value, index,
 				 buf, 0x0000001, 1000);
 	if (result)
 		dbg("%03d < %d bytes [0x%02X]", seq, result,
 		    ((unsigned char *)buf)[0]);
 	else
 		dbg("%03d < 0 bytes", seq);
 }

 static inline void ARK3116_RCV_QUIET(struct usb_serial *serial,
 				     __u8 request, __u8 requesttype,
 				     __u16 value, __u16 index, char *buf)
 {
 	usb_control_msg(serial->dev,
 			usb_rcvctrlpipe(serial->dev, 0),
 			request, requesttype, value, index,
 			buf, 0x0000001, 1000);
 }

 static int ark3116_attach(struct usb_serial *serial)
 {
 	char *buf;

 	buf = kmalloc(1, GFP_KERNEL);
 	if (!buf) {
 		dbg("error kmalloc -> out of mem?");
 		return -ENOMEM;
 	}

 	/* 3 */
 	ARK3116_SND(serial, 3, 0xFE, 0x40, 0x0008, 0x0002);
 	ARK3116_SND(serial, 4, 0xFE, 0x40, 0x0008, 0x0001);
 	ARK3116_SND(serial, 5, 0xFE, 0x40, 0x0000, 0x0008);
 	ARK3116_SND(serial, 6, 0xFE, 0x40, 0x0000, 0x000B);

 	/* <-- seq7 */
 	ARK3116_RCV(serial,  7, 0xFE, 0xC0, 0x0000, 0x0003, 0x00, buf);
 	ARK3116_SND(serial,  8, 0xFE, 0x40, 0x0080, 0x0003);
 	ARK3116_SND(serial,  9, 0xFE, 0x40, 0x001A, 0x0000);
 	ARK3116_SND(serial, 10, 0xFE, 0x40, 0x0000, 0x0001);
 	ARK3116_SND(serial, 11, 0xFE, 0x40, 0x0000, 0x0003);

 	/* <-- seq12 */
 	ARK3116_RCV(serial, 12, 0xFE, 0xC0, 0x0000, 0x0004, 0x00, buf);
 	ARK3116_SND(serial, 13, 0xFE, 0x40, 0x0000, 0x0004);

 	/* 14 */
 	ARK3116_RCV(serial, 14, 0xFE, 0xC0, 0x0000, 0x0004, 0x00, buf);
 	ARK3116_SND(serial, 15, 0xFE, 0x40, 0x0000, 0x0004);

 	/* 16 */
 	ARK3116_RCV(serial, 16, 0xFE, 0xC0, 0x0000, 0x0004, 0x00, buf);
 	/* --> seq17 */
 	ARK3116_SND(serial, 17, 0xFE, 0x40, 0x0001, 0x0004);

 	/* <-- seq18 */
 	ARK3116_RCV(serial, 18, 0xFE, 0xC0, 0x0000, 0x0004, 0x01, buf);

 	/* --> seq19 */
 	ARK3116_SND(serial, 19, 0xFE, 0x40, 0x0003, 0x0004);

 	/* <-- seq20 */
 	/* seems like serial port status info (RTS, CTS, ...) */
 	/* returns modem control line status?! */
 	ARK3116_RCV(serial, 20, 0xFE, 0xC0, 0x0000, 0x0006, 0xFF, buf);

 	/* set 9600 baud & do some init?! */
 	ARK3116_SND(serial, 147, 0xFE, 0x40, 0x0083, 0x0003);
 	ARK3116_SND(serial, 148, 0xFE, 0x40, 0x0038, 0x0000);
 	ARK3116_SND(serial, 149, 0xFE, 0x40, 0x0001, 0x0001);
 	ARK3116_SND(serial, 150, 0xFE, 0x40, 0x0003, 0x0003);
 	ARK3116_RCV(serial, 151, 0xFE, 0xC0, 0x0000, 0x0004, 0x03, buf);
 	ARK3116_SND(serial, 152, 0xFE, 0x40, 0x0000, 0x0003);
 	ARK3116_RCV(serial, 153, 0xFE, 0xC0, 0x0000, 0x0003, 0x00, buf);
 	ARK3116_SND(serial, 154, 0xFE, 0x40, 0x0003, 0x0003);

 	kfree(buf);
 	return 0;
 }

 static void ark3116_init_termios(struct tty_struct *tty)
 {
 	struct ktermios *termios = tty->termios;
 	*termios = tty_std_termios;
 	termios->c_cflag = B9600 | CS8
 				      | CREAD | HUPCL | CLOCAL;
 	termios->c_ispeed = 9600;
 	termios->c_ospeed = 9600;
 }

 static void ark3116_set_termios(struct tty_struct *tty,
 				struct usb_serial_port *port,
 				struct ktermios *old_termios)
 {
 	struct usb_serial *serial = port->serial;
 	struct ktermios *termios = tty->termios;
 	unsigned int cflag = termios->c_cflag;
 	int baud;
 	int ark3116_baud;
 	char *buf;
 	char config;

 	config = 0;

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


 	cflag = termios->c_cflag;
 	termios->c_cflag &= ~(CMSPAR|CRTSCTS);

 	buf = kmalloc(1, GFP_KERNEL);
 	if (!buf) {
 		dbg("error kmalloc");
 		*termios = *old_termios;
 		return;
 	}

 	/* set data bit count (8/7/6/5) */
 	if (cflag & CSIZE) {
 		switch (cflag & CSIZE) {
 		case CS5:
 			config |= 0x00;
 			dbg("setting CS5");
 			break;
 		case CS6:
 			config |= 0x01;
 			dbg("setting CS6");
 			break;
 		case CS7:
 			config |= 0x02;
 			dbg("setting CS7");
 			break;
 		default:
 			dbg("CSIZE was set but not CS5-CS8, using CS8!");
 			/* fall through */
 		case CS8:
 			config |= 0x03;
 			dbg("setting CS8");
 			break;
 		}
 	}

 	/* set parity (NONE/EVEN/ODD) */
 	if (cflag & PARENB) {
 		if (cflag & PARODD) {
 			config |= 0x08;
 			dbg("setting parity to ODD");
 		} else {
 			config |= 0x18;
 			dbg("setting parity to EVEN");
 		}
 	} else {
 		dbg("setting parity to NONE");
 	}

 	/* set stop bit (1/2) */
 	if (cflag & CSTOPB) {
 		config |= 0x04;
 		dbg("setting 2 stop bits");
 	} else {
 		dbg("setting 1 stop bit");
 	}

 	/* set baudrate */
 	baud = tty_get_baud_rate(tty);

 	switch (baud) {
 	case 75:
 	case 150:
 	case 300:
 	case 600:
 	case 1200:
 	case 1800:
 	case 2400:
 	case 4800:
 	case 9600:
 	case 19200:
 	case 38400:
 	case 57600:
 	case 115200:
 	case 230400:
 	case 460800:
 		/* Report the resulting rate back to the caller */
 		tty_encode_baud_rate(tty, baud, baud);
 		break;
 	/* set 9600 as default (if given baudrate is invalid for example) */
 	default:
 		tty_encode_baud_rate(tty, 9600, 9600);
 	case 0:
 		baud = 9600;
 	}

 	/*
 	 * found by try'n'error, be careful, maybe there are other options
 	 * for multiplicator etc! (3.5 for example)
 	 */
 	if (baud == 460800)
 		/* strange, for 460800 the formula is wrong
 		 * if using round() then 9600baud is wrong) */
 		ark3116_baud = 7;
 	else
 		ark3116_baud = 3000000 / baud;

 	/* ? */
 	ARK3116_RCV(serial, 0, 0xFE, 0xC0, 0x0000, 0x0003, 0x03, buf);

 	/* offset = buf[0]; */
 	/* offset = 0x03; */
 	/* dbg("using 0x%04X as target for 0x0003:", 0x0080 + offset); */

 	/* set baudrate */
 	dbg("setting baudrate to %d (->reg=%d)", baud, ark3116_baud);
 	ARK3116_SND(serial, 147, 0xFE, 0x40, 0x0083, 0x0003);
 	ARK3116_SND(serial, 148, 0xFE, 0x40,
 			    (ark3116_baud & 0x00FF), 0x0000);
 	ARK3116_SND(serial, 149, 0xFE, 0x40,
 			    (ark3116_baud & 0xFF00) >> 8, 0x0001);
 	ARK3116_SND(serial, 150, 0xFE, 0x40, 0x0003, 0x0003);

 	/* ? */
 	ARK3116_RCV(serial, 151, 0xFE, 0xC0, 0x0000, 0x0004, 0x03, buf);
 	ARK3116_SND(serial, 152, 0xFE, 0x40, 0x0000, 0x0003);

 	/* set data bit count, stop bit count & parity: */
 	dbg("updating bit count, stop bit or parity (cfg=0x%02X)", config);
 	ARK3116_RCV(serial, 153, 0xFE, 0xC0, 0x0000, 0x0003, 0x00, buf);
 	ARK3116_SND(serial, 154, 0xFE, 0x40, config, 0x0003);

 	if (cflag & CRTSCTS)
 		dbg("CRTSCTS not supported by chipset?!");

 	/* TEST ARK3116_SND(154, 0xFE, 0x40, 0xFFFF, 0x0006); */

 	kfree(buf);

 	return;
 }

 static int ark3116_open(struct tty_struct *tty, struct usb_serial_port *port)
 {
 	struct ktermios tmp_termios;
 	struct usb_serial *serial = port->serial;
 	char *buf;
 	int result = 0;

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

 	buf = kmalloc(1, GFP_KERNEL);
 	if (!buf) {
 		dbg("error kmalloc -> out of mem?");
 		return -ENOMEM;
 	}

 	result = usb_serial_generic_open(tty, port);
 	if (result)
 		goto err_out;

 	/* open */
 	ARK3116_RCV(serial, 111, 0xFE, 0xC0, 0x0000, 0x0003, 0x02, buf);

 	ARK3116_SND(serial, 112, 0xFE, 0x40, 0x0082, 0x0003);
 	ARK3116_SND(serial, 113, 0xFE, 0x40, 0x001A, 0x0000);
 	ARK3116_SND(serial, 114, 0xFE, 0x40, 0x0000, 0x0001);
 	ARK3116_SND(serial, 115, 0xFE, 0x40, 0x0002, 0x0003);

 	ARK3116_RCV(serial, 116, 0xFE, 0xC0, 0x0000, 0x0004, 0x03, buf);
 	ARK3116_SND(serial, 117, 0xFE, 0x40, 0x0002, 0x0004);

 	ARK3116_RCV(serial, 118, 0xFE, 0xC0, 0x0000, 0x0004, 0x02, buf);
 	ARK3116_SND(serial, 119, 0xFE, 0x40, 0x0000, 0x0004);

 	ARK3116_RCV(serial, 120, 0xFE, 0xC0, 0x0000, 0x0004, 0x00, buf);

 	ARK3116_SND(serial, 121, 0xFE, 0x40, 0x0001, 0x0004);

 	ARK3116_RCV(serial, 122, 0xFE, 0xC0, 0x0000, 0x0004, 0x01, buf);

 	ARK3116_SND(serial, 123, 0xFE, 0x40, 0x0003, 0x0004);

 	/* returns different values (control lines?!) */
 	ARK3116_RCV(serial, 124, 0xFE, 0xC0, 0x0000, 0x0006, 0xFF, buf);

 	/* initialise termios */
 	if (tty)
 		ark3116_set_termios(tty, port, &tmp_termios);

 err_out:
 	kfree(buf);

 	return result;
 }

 static int ark3116_ioctl(struct tty_struct *tty, struct file *file,
 			 unsigned int cmd, unsigned long arg)
 {
 	struct usb_serial_port *port = tty->driver_data;
 	struct serial_struct serstruct;
 	void __user *user_arg = (void __user *)arg;

 	switch (cmd) {
 	case TIOCGSERIAL:
 		/* XXX: Some of these values are probably wrong. */
 		memset(&serstruct, 0, sizeof(serstruct));
 		serstruct.type = PORT_16654;
 		serstruct.line = port->serial->minor;
 		serstruct.port = port->number;
 		serstruct.custom_divisor = 0;
 		serstruct.baud_base = 460800;

 		if (copy_to_user(user_arg, &serstruct, sizeof(serstruct)))
 			return -EFAULT;

 		return 0;
 	case TIOCSSERIAL:
 		if (copy_from_user(&serstruct, user_arg, sizeof(serstruct)))
 			return -EFAULT;
 		return 0;
 	default:
 		dbg("%s cmd 0x%04x not supported", __func__, cmd);
 		break;
 	}

 	return -ENOIOCTLCMD;
 }

 static int ark3116_tiocmget(struct tty_struct *tty, struct file *file)
 {
 	struct usb_serial_port *port = tty->driver_data;
 	struct usb_serial *serial = port->serial;
 	char *buf;
 	char temp;

 	/* seems like serial port status info (RTS, CTS, ...) is stored
 	 * in reg(?) 0x0006
 	 * pcb connection point 11 = GND -> sets bit4 of response
 	 * pcb connection point  7 = GND -> sets bit6 of response
 	 */

 	buf = kmalloc(1, GFP_KERNEL);
 	if (!buf) {
 		dbg("error kmalloc");
 		return -ENOMEM;
 	}

 	/* read register */
 	ARK3116_RCV_QUIET(serial, 0xFE, 0xC0, 0x0000, 0x0006, buf);
 	temp = buf[0];
 	kfree(buf);

 	/* i do not really know if bit4=CTS and bit6=DSR... just a
 	 * quick guess!
 	 */
 	return (temp & (1<<4) ? TIOCM_CTS : 0)
 	       | (temp & (1<<6) ? TIOCM_DSR : 0);
 }

 static struct usb_driver ark3116_driver = {
 	.name =		"ark3116",
 	.probe =	usb_serial_probe,
 	.disconnect =	usb_serial_disconnect,
 	.id_table =	id_table,
 	.no_dynamic_id =	1,
 };

 static struct usb_serial_driver ark3116_device = {
 	.driver = {
 		.owner =	THIS_MODULE,
 		.name =		"ark3116",
 	},
 	.id_table =		id_table,
 	.usb_driver =		&ark3116_driver,
 	.num_ports =		1,
 	.attach =		ark3116_attach,
 	.set_termios =		ark3116_set_termios,
 	.init_termios =		ark3116_init_termios,
 	.ioctl =		ark3116_ioctl,
 	.tiocmget =		ark3116_tiocmget,
 	.open =			ark3116_open,
 };

 static int __init ark3116_init(void)
 {
 	int retval;

 	retval = usb_serial_register(&ark3116_device);
 	if (retval)
 		return retval;
 	retval = usb_register(&ark3116_driver);
 	if (retval)
 		usb_serial_deregister(&ark3116_device);
 	return retval;
 }

 static void __exit ark3116_exit(void)
 {
 	usb_deregister(&ark3116_driver);
 	usb_serial_deregister(&ark3116_device);
 }

 module_init(ark3116_init);
 module_exit(ark3116_exit);
 MODULE_LICENSE("GPL");

 module_param(debug, bool, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(debug, "Debug enabled or not");
	/*
	* Copyright (C) 2006
	* Simon Schulz (ark3116_driver <at> auctionant.de)
	*
	* ark3116
	* - implements a driver for the arkmicro ark3116 chipset (vendor=0x6547,
	* productid=0x0232) (used in a datacable called KQ-U8A)
	*
	* - based on code by krisfx -> thanks !!
	* (see http://www.linuxquestions.org/questions/showthread.php?p=2184457#post2184457)
	*
	* - based on logs created by usbsnoopy
	*
	* 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.
	*/

	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/tty.h>
	#include <linux/module.h>
	#include <linux/usb.h>
	#include <linux/usb/serial.h>
	#include <linux/serial.h>
	#include <linux/uaccess.h>


	static int debug;

	static struct usb_device_id id_table [] = {
	{ USB_DEVICE(0x6547, 0x0232) },
	{ },
	};
	MODULE_DEVICE_TABLE(usb, id_table);

	static inline void ARK3116_SND(struct usb_serial *serial, int seq,
	__u8 request, __u8 requesttype,
	__u16 value, __u16 index)
	{
	int result;
	result = usb_control_msg(serial->dev,
	usb_sndctrlpipe(serial->dev, 0),
	request, requesttype, value, index,
	NULL, 0x00, 1000);
	dbg("%03d > ok", seq);
	}

	static inline void ARK3116_RCV(struct usb_serial *serial, int seq,
	__u8 request, __u8 requesttype,
	__u16 value, __u16 index, __u8 expected,
	char *buf)
	{
	int result;
	result = usb_control_msg(serial->dev,
	usb_rcvctrlpipe(serial->dev, 0),
	request, requesttype, value, index,
	buf, 0x0000001, 1000);
	if (result)
	dbg("%03d < %d bytes [0x%02X]", seq, result,
	((unsigned char *)buf)[0]);
	else
	dbg("%03d < 0 bytes", seq);
	}

	static inline void ARK3116_RCV_QUIET(struct usb_serial *serial,
	__u8 request, __u8 requesttype,
	__u16 value, __u16 index, char *buf)
	{
	usb_control_msg(serial->dev,
	usb_rcvctrlpipe(serial->dev, 0),
	request, requesttype, value, index,
	buf, 0x0000001, 1000);
	}

	static int ark3116_attach(struct usb_serial *serial)
	{
	char *buf;

	buf = kmalloc(1, GFP_KERNEL);
	if (!buf) {
	dbg("error kmalloc -> out of mem?");
	return -ENOMEM;
	}

	/* 3 */
	ARK3116_SND(serial, 3, 0xFE, 0x40, 0x0008, 0x0002);
	ARK3116_SND(serial, 4, 0xFE, 0x40, 0x0008, 0x0001);
	ARK3116_SND(serial, 5, 0xFE, 0x40, 0x0000, 0x0008);
	ARK3116_SND(serial, 6, 0xFE, 0x40, 0x0000, 0x000B);

	/* <-- seq7 */
	ARK3116_RCV(serial, 7, 0xFE, 0xC0, 0x0000, 0x0003, 0x00, buf);
	ARK3116_SND(serial, 8, 0xFE, 0x40, 0x0080, 0x0003);
	ARK3116_SND(serial, 9, 0xFE, 0x40, 0x001A, 0x0000);
	ARK3116_SND(serial, 10, 0xFE, 0x40, 0x0000, 0x0001);
	ARK3116_SND(serial, 11, 0xFE, 0x40, 0x0000, 0x0003);

	/* <-- seq12 */
	ARK3116_RCV(serial, 12, 0xFE, 0xC0, 0x0000, 0x0004, 0x00, buf);
	ARK3116_SND(serial, 13, 0xFE, 0x40, 0x0000, 0x0004);

	/* 14 */
	ARK3116_RCV(serial, 14, 0xFE, 0xC0, 0x0000, 0x0004, 0x00, buf);
	ARK3116_SND(serial, 15, 0xFE, 0x40, 0x0000, 0x0004);

	/* 16 */
	ARK3116_RCV(serial, 16, 0xFE, 0xC0, 0x0000, 0x0004, 0x00, buf);
	/* --> seq17 */
	ARK3116_SND(serial, 17, 0xFE, 0x40, 0x0001, 0x0004);

	/* <-- seq18 */
	ARK3116_RCV(serial, 18, 0xFE, 0xC0, 0x0000, 0x0004, 0x01, buf);

	/* --> seq19 */
	ARK3116_SND(serial, 19, 0xFE, 0x40, 0x0003, 0x0004);

	/* <-- seq20 */
	/* seems like serial port status info (RTS, CTS, ...) */
	/* returns modem control line status?! */
	ARK3116_RCV(serial, 20, 0xFE, 0xC0, 0x0000, 0x0006, 0xFF, buf);

	/* set 9600 baud & do some init?! */
	ARK3116_SND(serial, 147, 0xFE, 0x40, 0x0083, 0x0003);
	ARK3116_SND(serial, 148, 0xFE, 0x40, 0x0038, 0x0000);
	ARK3116_SND(serial, 149, 0xFE, 0x40, 0x0001, 0x0001);
	ARK3116_SND(serial, 150, 0xFE, 0x40, 0x0003, 0x0003);
	ARK3116_RCV(serial, 151, 0xFE, 0xC0, 0x0000, 0x0004, 0x03, buf);
	ARK3116_SND(serial, 152, 0xFE, 0x40, 0x0000, 0x0003);
	ARK3116_RCV(serial, 153, 0xFE, 0xC0, 0x0000, 0x0003, 0x00, buf);
	ARK3116_SND(serial, 154, 0xFE, 0x40, 0x0003, 0x0003);

	kfree(buf);
	return 0;
	}

	static void ark3116_init_termios(struct tty_struct *tty)
	{
	struct ktermios *termios = tty->termios;
	*termios = tty_std_termios;
	termios->c_cflag = B9600 \| CS8
	\| CREAD \| HUPCL \| CLOCAL;
	termios->c_ispeed = 9600;
	termios->c_ospeed = 9600;
	}

	static void ark3116_set_termios(struct tty_struct *tty,
	struct usb_serial_port *port,
	struct ktermios *old_termios)
	{
	struct usb_serial *serial = port->serial;
	struct ktermios *termios = tty->termios;
	unsigned int cflag = termios->c_cflag;
	int baud;
	int ark3116_baud;
	char *buf;
	char config;

	config = 0;

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


	cflag = termios->c_cflag;
	termios->c_cflag &= ~(CMSPAR\|CRTSCTS);

	buf = kmalloc(1, GFP_KERNEL);
	if (!buf) {
	dbg("error kmalloc");
	termios = old_termios;
	return;
	}

	/* set data bit count (8/7/6/5) */
	if (cflag & CSIZE) {
	switch (cflag & CSIZE) {
	case CS5:
	config \|= 0x00;
	dbg("setting CS5");
	break;
	case CS6:
	config \|= 0x01;
	dbg("setting CS6");
	break;
	case CS7:
	config \|= 0x02;
	dbg("setting CS7");
	break;
	default:
	dbg("CSIZE was set but not CS5-CS8, using CS8!");
	/* fall through */
	case CS8:
	config \|= 0x03;
	dbg("setting CS8");
	break;
	}
	}

	/* set parity (NONE/EVEN/ODD) */
	if (cflag & PARENB) {
	if (cflag & PARODD) {
	config \|= 0x08;
	dbg("setting parity to ODD");
	} else {
	config \|= 0x18;
	dbg("setting parity to EVEN");
	}
	} else {
	dbg("setting parity to NONE");
	}

	/* set stop bit (1/2) */
	if (cflag & CSTOPB) {
	config \|= 0x04;
	dbg("setting 2 stop bits");
	} else {
	dbg("setting 1 stop bit");
	}

	/* set baudrate */
	baud = tty_get_baud_rate(tty);

	switch (baud) {
	case 75:
	case 150:
	case 300:
	case 600:
	case 1200:
	case 1800:
	case 2400:
	case 4800:
	case 9600:
	case 19200:
	case 38400:
	case 57600:
	case 115200:
	case 230400:
	case 460800:
	/* Report the resulting rate back to the caller */
	tty_encode_baud_rate(tty, baud, baud);
	break;
	/* set 9600 as default (if given baudrate is invalid for example) */
	default:
	tty_encode_baud_rate(tty, 9600, 9600);
	case 0:
	baud = 9600;
	}

	/*
	* found by try'n'error, be careful, maybe there are other options
	* for multiplicator etc! (3.5 for example)
	*/
	if (baud == 460800)
	/* strange, for 460800 the formula is wrong
	* if using round() then 9600baud is wrong) */
	ark3116_baud = 7;
	else
	ark3116_baud = 3000000 / baud;

	/* ? */
	ARK3116_RCV(serial, 0, 0xFE, 0xC0, 0x0000, 0x0003, 0x03, buf);

	/* offset = buf[0]; */
	/* offset = 0x03; */
	/* dbg("using 0x%04X as target for 0x0003:", 0x0080 + offset); */

	/* set baudrate */
	dbg("setting baudrate to %d (->reg=%d)", baud, ark3116_baud);
	ARK3116_SND(serial, 147, 0xFE, 0x40, 0x0083, 0x0003);
	ARK3116_SND(serial, 148, 0xFE, 0x40,
	(ark3116_baud & 0x00FF), 0x0000);
	ARK3116_SND(serial, 149, 0xFE, 0x40,
	(ark3116_baud & 0xFF00) >> 8, 0x0001);
	ARK3116_SND(serial, 150, 0xFE, 0x40, 0x0003, 0x0003);

	/* ? */
	ARK3116_RCV(serial, 151, 0xFE, 0xC0, 0x0000, 0x0004, 0x03, buf);
	ARK3116_SND(serial, 152, 0xFE, 0x40, 0x0000, 0x0003);

	/* set data bit count, stop bit count & parity: */
	dbg("updating bit count, stop bit or parity (cfg=0x%02X)", config);
	ARK3116_RCV(serial, 153, 0xFE, 0xC0, 0x0000, 0x0003, 0x00, buf);
	ARK3116_SND(serial, 154, 0xFE, 0x40, config, 0x0003);

	if (cflag & CRTSCTS)
	dbg("CRTSCTS not supported by chipset?!");

	/* TEST ARK3116_SND(154, 0xFE, 0x40, 0xFFFF, 0x0006); */

	kfree(buf);

	return;
	}

	static int ark3116_open(struct tty_struct tty, struct usb_serial_port port)
	{
	struct ktermios tmp_termios;
	struct usb_serial *serial = port->serial;
	char *buf;
	int result = 0;

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

	buf = kmalloc(1, GFP_KERNEL);
	if (!buf) {
	dbg("error kmalloc -> out of mem?");
	return -ENOMEM;
	}

	result = usb_serial_generic_open(tty, port);
	if (result)
	goto err_out;

	/* open */
	ARK3116_RCV(serial, 111, 0xFE, 0xC0, 0x0000, 0x0003, 0x02, buf);

	ARK3116_SND(serial, 112, 0xFE, 0x40, 0x0082, 0x0003);
	ARK3116_SND(serial, 113, 0xFE, 0x40, 0x001A, 0x0000);
	ARK3116_SND(serial, 114, 0xFE, 0x40, 0x0000, 0x0001);
	ARK3116_SND(serial, 115, 0xFE, 0x40, 0x0002, 0x0003);

	ARK3116_RCV(serial, 116, 0xFE, 0xC0, 0x0000, 0x0004, 0x03, buf);
	ARK3116_SND(serial, 117, 0xFE, 0x40, 0x0002, 0x0004);

	ARK3116_RCV(serial, 118, 0xFE, 0xC0, 0x0000, 0x0004, 0x02, buf);
	ARK3116_SND(serial, 119, 0xFE, 0x40, 0x0000, 0x0004);

	ARK3116_RCV(serial, 120, 0xFE, 0xC0, 0x0000, 0x0004, 0x00, buf);

	ARK3116_SND(serial, 121, 0xFE, 0x40, 0x0001, 0x0004);

	ARK3116_RCV(serial, 122, 0xFE, 0xC0, 0x0000, 0x0004, 0x01, buf);

	ARK3116_SND(serial, 123, 0xFE, 0x40, 0x0003, 0x0004);

	/* returns different values (control lines?!) */
	ARK3116_RCV(serial, 124, 0xFE, 0xC0, 0x0000, 0x0006, 0xFF, buf);

	/* initialise termios */
	if (tty)
	ark3116_set_termios(tty, port, &tmp_termios);

	err_out:
	kfree(buf);

	return result;
	}

	static int ark3116_ioctl(struct tty_struct tty, struct file file,
	unsigned int cmd, unsigned long arg)
	{
	struct usb_serial_port *port = tty->driver_data;
	struct serial_struct serstruct;
	void __user user_arg = (void __user )arg;

	switch (cmd) {
	case TIOCGSERIAL:
	/* XXX: Some of these values are probably wrong. */
	memset(&serstruct, 0, sizeof(serstruct));
	serstruct.type = PORT_16654;
	serstruct.line = port->serial->minor;
	serstruct.port = port->number;
	serstruct.custom_divisor = 0;
	serstruct.baud_base = 460800;

	if (copy_to_user(user_arg, &serstruct, sizeof(serstruct)))
	return -EFAULT;

	return 0;
	case TIOCSSERIAL:
	if (copy_from_user(&serstruct, user_arg, sizeof(serstruct)))
	return -EFAULT;
	return 0;
	default:
	dbg("%s cmd 0x%04x not supported", __func__, cmd);
	break;
	}

	return -ENOIOCTLCMD;
	}

	static int ark3116_tiocmget(struct tty_struct tty, struct file file)
	{
	struct usb_serial_port *port = tty->driver_data;
	struct usb_serial *serial = port->serial;
	char *buf;
	char temp;

	/* seems like serial port status info (RTS, CTS, ...) is stored
	* in reg(?) 0x0006
	* pcb connection point 11 = GND -> sets bit4 of response
	* pcb connection point 7 = GND -> sets bit6 of response
	*/

	buf = kmalloc(1, GFP_KERNEL);
	if (!buf) {
	dbg("error kmalloc");
	return -ENOMEM;
	}

	/* read register */
	ARK3116_RCV_QUIET(serial, 0xFE, 0xC0, 0x0000, 0x0006, buf);
	temp = buf[0];
	kfree(buf);

	/* i do not really know if bit4=CTS and bit6=DSR... just a
	* quick guess!
	*/
	return (temp & (1<<4) ? TIOCM_CTS : 0)
	\| (temp & (1<<6) ? TIOCM_DSR : 0);
	}

	static struct usb_driver ark3116_driver = {
	.name = "ark3116",
	.probe = usb_serial_probe,
	.disconnect = usb_serial_disconnect,
	.id_table = id_table,
	.no_dynamic_id = 1,
	};

	static struct usb_serial_driver ark3116_device = {
	.driver = {
	.owner = THIS_MODULE,
	.name = "ark3116",
	},
	.id_table = id_table,
	.usb_driver = &ark3116_driver,
	.num_ports = 1,
	.attach = ark3116_attach,
	.set_termios = ark3116_set_termios,
	.init_termios = ark3116_init_termios,
	.ioctl = ark3116_ioctl,
	.tiocmget = ark3116_tiocmget,
	.open = ark3116_open,
	};

	static int __init ark3116_init(void)
	{
	int retval;

	retval = usb_serial_register(&ark3116_device);
	if (retval)
	return retval;
	retval = usb_register(&ark3116_driver);
	if (retval)
	usb_serial_deregister(&ark3116_device);
	return retval;
	}

	static void __exit ark3116_exit(void)
	{
	usb_deregister(&ark3116_driver);
	usb_serial_deregister(&ark3116_device);
	}

	module_init(ark3116_init);
	module_exit(ark3116_exit);
	MODULE_LICENSE("GPL");

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