mct_u232.c

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/*
 * MCT (Magic Control Technology Corp.) USB RS232 Converter Driver
 *
 *   Copyright (C) 2000 Wolfgang Grandegger ([e-mail])
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 * This program is largely derived from the Belkin USB Serial Adapter Driver
 * (see belkin_sa.[ch]). All of the information about the device was acquired
 * by using SniffUSB on Windows98. For technical details see mct_u232.h.
 *
 * William G. Greathouse and Greg Kroah-Hartman provided great help on how to
 * do the reverse engineering and how to write a USB serial device driver.
 *
 * TO BE DONE, TO BE CHECKED:
 *   DTR/RTS signal handling may be incomplete or incorrect. I have mainly
 *   implemented what I have seen with SniffUSB or found in belkin_sa.c.
 *   For further TODOs check also belkin_sa.c.
 *
 * TEST STATUS:
 *   Basic tests have been performed with minicom/zmodem transfers and
 *   modem dialing under Linux 2.4.0-test10 (for me it works fine).
 *
 * 04-Nov-2003 Bill Marr <marr at flex dot com>
 *   - Mimic Windows driver by sending 2 USB 'device request' messages
 *     following normal 'baud rate change' message.  This allows data to be
 *     transmitted to RS-232 devices which don't assert the 'CTS' signal.
 *
 * 10-Nov-2001 Wolfgang Grandegger
 *   - Fixed an endianess problem with the baudrate selection for PowerPC.
 *
 * 06-Dec-2001 Martin Hamilton <[e-mail]>
 *	Added support for the Belkin F5U109 DB9 adaptor
 *
 * 30-May-2001 Greg Kroah-Hartman
 *	switched from using spinlock to a semaphore, which fixes lots of problems.
 *
 * 04-May-2001 Stelian Pop
 *   - Set the maximum bulk output size for Sitecom U232-P25 model to 16 bytes
 *     instead of the device reported 32 (using 32 bytes causes many data
 *     loss, Windows driver uses 16 too).
 *
 * 02-May-2001 Stelian Pop
 *   - Fixed the baud calculation for Sitecom U232-P25 model
 *
 * 08-Apr-2001 gb
 *   - Identify version on module load.
 *
 * 06-Jan-2001 Cornel Ciocirlan 
 *   - Added support for Sitecom U232-P25 model (Product Id 0x0230)
 *   - Added support for D-Link DU-H3SP USB BAY (Product Id 0x0200)
 *
 * 29-Nov-2000 Greg Kroah-Hartman
 *   - Added device id table to fit with 2.4.0-test11 structure.
 *   - took out DEAL_WITH_TWO_INT_IN_ENDPOINTS #define as it's not needed
 *     (lots of things will change if/when the usb-serial core changes to
 *     handle these issues.
 *
 * 27-Nov-2000 Wolfgang Grandegger
 *   A version for kernel 2.4.0-test10 released to the Linux community 
 *   (via linux-usb-devel).
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <asm/uaccess.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include "mct_u232.h"

/*
 * Version Information
 */
#define DRIVER_VERSION "z2.1"		/* Linux in-kernel version */
#define DRIVER_AUTHOR "Wolfgang Grandegger <[e-mail]>"
#define DRIVER_DESC "Magic Control Technology USB-RS232 converter driver"

static int debug;

/*
 * Function prototypes
 */
static int  mct_u232_startup	         (struct usb_serial *serial);
static void mct_u232_shutdown	         (struct usb_serial *serial);
static int  mct_u232_open	         (struct usb_serial_port *port,
					  struct file *filp);
static void mct_u232_close	         (struct usb_serial_port *port,
					  struct file *filp);
static void mct_u232_read_int_callback   (struct urb *urb);
static void mct_u232_set_termios         (struct usb_serial_port *port,
					  struct ktermios * old);
static int  mct_u232_ioctl	         (struct usb_serial_port *port,
					  struct file * file,
					  unsigned int cmd,
					  unsigned long arg);
static void mct_u232_break_ctl	         (struct usb_serial_port *port,
					  int break_state );
static int  mct_u232_tiocmget		 (struct usb_serial_port *port,
					  struct file *file);
static int  mct_u232_tiocmset		 (struct usb_serial_port *port,
					  struct file *file, unsigned int set,
					  unsigned int clear);
static void mct_u232_throttle		 (struct usb_serial_port *port);
static void mct_u232_unthrottle		 (struct usb_serial_port *port);


/*
 * All of the device info needed for the MCT USB-RS232 converter.
 */
static struct usb_device_id id_table_combined [] = {
	{ USB_DEVICE(MCT_U232_VID, MCT_U232_PID) },
	{ USB_DEVICE(MCT_U232_VID, MCT_U232_SITECOM_PID) },
	{ USB_DEVICE(MCT_U232_VID, MCT_U232_DU_H3SP_PID) },
	{ USB_DEVICE(MCT_U232_BELKIN_F5U109_VID, MCT_U232_BELKIN_F5U109_PID) },
	{ }		/* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, id_table_combined);

static struct usb_driver mct_u232_driver = {
	.name =		"mct_u232",
	.probe =	usb_serial_probe,
	.disconnect =	usb_serial_disconnect,
	.id_table =	id_table_combined,
	.no_dynamic_id = 	1,
};

static struct usb_serial_driver mct_u232_device = {
	.driver = {
		.owner =	THIS_MODULE,
		.name =		"mct_u232",
	},
	.description =	     "MCT U232",
	.usb_driver = 	     &mct_u232_driver,
	.id_table =	     id_table_combined,
	.num_interrupt_in =  2,
	.num_bulk_in =	     0,
	.num_bulk_out =	     1,
	.num_ports =	     1,
	.open =		     mct_u232_open,
	.close =	     mct_u232_close,
	.throttle =	     mct_u232_throttle,
	.unthrottle =	     mct_u232_unthrottle,
	.read_int_callback = mct_u232_read_int_callback,
	.ioctl =	     mct_u232_ioctl,
	.set_termios =	     mct_u232_set_termios,
	.break_ctl =	     mct_u232_break_ctl,
	.tiocmget =	     mct_u232_tiocmget,
	.tiocmset =	     mct_u232_tiocmset,
	.attach =	     mct_u232_startup,
	.shutdown =	     mct_u232_shutdown,
};


struct mct_u232_private {
	spinlock_t lock;
	unsigned int	     control_state; /* Modem Line Setting (TIOCM) */
	unsigned char        last_lcr;      /* Line Control Register */
	unsigned char	     last_lsr;      /* Line Status Register */
	unsigned char	     last_msr;      /* Modem Status Register */
	unsigned int	     rx_flags;      /* Throttling flags */
};

#define THROTTLED		0x01

/*
 * Handle vendor specific USB requests
 */

#define WDR_TIMEOUT 5000 /* default urb timeout */

/*
 * Later day 2.6.0-test kernels have new baud rates like B230400 which
 * we do not know how to support. We ignore them for the moment.
 * XXX Rate-limit the error message, it's user triggerable.
 */
static int mct_u232_calculate_baud_rate(struct usb_serial *serial, speed_t value)
{
	if (le16_to_cpu(serial->dev->descriptor.idProduct) == MCT_U232_SITECOM_PID
	  || le16_to_cpu(serial->dev->descriptor.idProduct) == MCT_U232_BELKIN_F5U109_PID) {
		switch (value) {
		case    300: return 0x01;
		case    600: return 0x02; /* this one not tested */
		case   1200: return 0x03;
		case   2400: return 0x04;
		case   4800: return 0x06;
		case   9600: return 0x08;
		case  19200: return 0x09;
		case  38400: return 0x0a;
		case  57600: return 0x0b;
		case 115200: return 0x0c;
		default:
			err("MCT USB-RS232: unsupported baudrate request 0x%x,"
			    " using default of B9600", value);
			return 0x08;
		}
	} else {
		switch (value) {
		case 300: break;
		case 600: break;
		case 1200: break;
		case 2400: break;
		case 4800: break;
		case 9600: break;
		case 19200: break;
		case 38400: break;
		case 57600: break;
		case 115200: break;
		default:
			err("MCT USB-RS232: unsupported baudrate request 0x%x,"
			    " using default of B9600", value);
			value = 9600;
		}
		return 115200/value;
	}
}

static int mct_u232_set_baud_rate(struct usb_serial *serial, struct usb_serial_port *port,
				  speed_t value)
{
	__le32 divisor;
        int rc;
        unsigned char zero_byte = 0;
        unsigned char cts_enable_byte = 0;

	divisor = cpu_to_le32(mct_u232_calculate_baud_rate(serial, value));

        rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
                             MCT_U232_SET_BAUD_RATE_REQUEST,
			     MCT_U232_SET_REQUEST_TYPE,
                             0, 0, &divisor, MCT_U232_SET_BAUD_RATE_SIZE,
			     WDR_TIMEOUT);
	if (rc < 0)
		err("Set BAUD RATE %d failed (error = %d)", value, rc);
	dbg("set_baud_rate: value: 0x%x, divisor: 0x%x", value, divisor);

	/* Mimic the MCT-supplied Windows driver (version 1.21P.0104), which
	   always sends two extra USB 'device request' messages after the
	   'baud rate change' message.  The actual functionality of the
	   request codes in these messages is not fully understood but these
	   particular codes are never seen in any operation besides a baud
	   rate change.  Both of these messages send a single byte of data.
	   In the first message, the value of this byte is always zero.

	   The second message has been determined experimentally to control
	   whether data will be transmitted to a device which is not asserting
	   the 'CTS' signal.  If the second message's data byte is zero, data
	   will be transmitted even if 'CTS' is not asserted (i.e. no hardware
	   flow control).  if the second message's data byte is nonzero (a value
	   of 1 is used by this driver), data will not be transmitted to a device
	   which is not asserting 'CTS'.
	*/

	rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
			     MCT_U232_SET_UNKNOWN1_REQUEST, 
			     MCT_U232_SET_REQUEST_TYPE,
			     0, 0, &zero_byte, MCT_U232_SET_UNKNOWN1_SIZE, 
			     WDR_TIMEOUT);
	if (rc < 0)
		err("Sending USB device request code %d failed (error = %d)", 
		    MCT_U232_SET_UNKNOWN1_REQUEST, rc);

	if (port && C_CRTSCTS(port->tty)) {
	   cts_enable_byte = 1;
	}

        dbg("set_baud_rate: send second control message, data = %02X", cts_enable_byte);
	rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
			     MCT_U232_SET_CTS_REQUEST,
			     MCT_U232_SET_REQUEST_TYPE,
			     0, 0, &cts_enable_byte, MCT_U232_SET_CTS_SIZE,
			     WDR_TIMEOUT);
	if (rc < 0)
	  err("Sending USB device request code %d failed (error = %d)",
	      MCT_U232_SET_CTS_REQUEST, rc);

        return rc;
} /* mct_u232_set_baud_rate */

static int mct_u232_set_line_ctrl(struct usb_serial *serial, unsigned char lcr)
{
        int rc;
        rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
                             MCT_U232_SET_LINE_CTRL_REQUEST,
			     MCT_U232_SET_REQUEST_TYPE,
                             0, 0, &lcr, MCT_U232_SET_LINE_CTRL_SIZE,
			     WDR_TIMEOUT);
	if (rc < 0)
		err("Set LINE CTRL 0x%x failed (error = %d)", lcr, rc);
	dbg("set_line_ctrl: 0x%x", lcr);
        return rc;
} /* mct_u232_set_line_ctrl */

static int mct_u232_set_modem_ctrl(struct usb_serial *serial,
				   unsigned int control_state)
{
        int rc;
	unsigned char mcr = MCT_U232_MCR_NONE;

	if (control_state & TIOCM_DTR)
		mcr |= MCT_U232_MCR_DTR;
	if (control_state & TIOCM_RTS)
		mcr |= MCT_U232_MCR_RTS;

        rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
                             MCT_U232_SET_MODEM_CTRL_REQUEST,
			     MCT_U232_SET_REQUEST_TYPE,
                             0, 0, &mcr, MCT_U232_SET_MODEM_CTRL_SIZE,
			     WDR_TIMEOUT);
	if (rc < 0)
		err("Set MODEM CTRL 0x%x failed (error = %d)", mcr, rc);
	dbg("set_modem_ctrl: state=0x%x ==> mcr=0x%x", control_state, mcr);

        return rc;
} /* mct_u232_set_modem_ctrl */

static int mct_u232_get_modem_stat(struct usb_serial *serial, unsigned char *msr)
{
        int rc;
        rc = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
                             MCT_U232_GET_MODEM_STAT_REQUEST,
			     MCT_U232_GET_REQUEST_TYPE,
                             0, 0, msr, MCT_U232_GET_MODEM_STAT_SIZE,
			     WDR_TIMEOUT);
	if (rc < 0) {
		err("Get MODEM STATus failed (error = %d)", rc);
		*msr = 0;
	}
	dbg("get_modem_stat: 0x%x", *msr);
        return rc;
} /* mct_u232_get_modem_stat */

static void mct_u232_msr_to_state(unsigned int *control_state, unsigned char msr)
{
 	/* Translate Control Line states */
	if (msr & MCT_U232_MSR_DSR)
		*control_state |=  TIOCM_DSR;
	else
		*control_state &= ~TIOCM_DSR;
	if (msr & MCT_U232_MSR_CTS)
		*control_state |=  TIOCM_CTS;
	else
		*control_state &= ~TIOCM_CTS;
	if (msr & MCT_U232_MSR_RI)
		*control_state |=  TIOCM_RI;
	else
		*control_state &= ~TIOCM_RI;
	if (msr & MCT_U232_MSR_CD)
		*control_state |=  TIOCM_CD;
	else
		*control_state &= ~TIOCM_CD;
 	dbg("msr_to_state: msr=0x%x ==> state=0x%x", msr, *control_state);
} /* mct_u232_msr_to_state */

/*
 * Driver's tty interface functions
 */

static int mct_u232_startup (struct usb_serial *serial)
{
	struct mct_u232_private *priv;
	struct usb_serial_port *port, *rport;

	priv = kzalloc(sizeof(struct mct_u232_private), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;
	spin_lock_init(&priv->lock);
	usb_set_serial_port_data(serial->port[0], priv);

	init_waitqueue_head(&serial->port[0]->write_wait);

	/* Puh, that's dirty */
	port = serial->port[0];
	rport = serial->port[1];
	/* No unlinking, it wasn't submitted yet. */
	usb_free_urb(port->read_urb);
	port->read_urb = rport->interrupt_in_urb;
	rport->interrupt_in_urb = NULL;
	port->read_urb->context = port;

	return (0);
} /* mct_u232_startup */


static void mct_u232_shutdown (struct usb_serial *serial)
{
	struct mct_u232_private *priv;
	int i;
	
	dbg("%s", __FUNCTION__);

	for (i=0; i < serial->num_ports; ++i) {
		/* My special items, the standard routines free my urbs */
		priv = usb_get_serial_port_data(serial->port[i]);
		if (priv) {
			usb_set_serial_port_data(serial->port[i], NULL);
			kfree(priv);
		}
	}
} /* mct_u232_shutdown */

static int  mct_u232_open (struct usb_serial_port *port, struct file *filp)
{
	struct usb_serial *serial = port->serial;
	struct mct_u232_private *priv = usb_get_serial_port_data(port);
	int retval = 0;
	unsigned int control_state;
	unsigned long flags;
	unsigned char last_lcr;
	unsigned char last_msr;

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

	/* Compensate for a hardware bug: although the Sitecom U232-P25
	 * device reports a maximum output packet size of 32 bytes,
	 * it seems to be able to accept only 16 bytes (and that's what