xref: /linux/drivers/usb/serial/mct_u232.c (revision 858259cf7d1c443c836a2022b78cb281f0a9b95e)
1 /*
2  * MCT (Magic Control Technology Corp.) USB RS232 Converter Driver
3  *
4  *   Copyright (C) 2000 Wolfgang Grandegger (wolfgang@ces.ch)
5  *
6  *   This program is free software; you can redistribute it and/or modify
7  *   it under the terms of the GNU General Public License as published by
8  *   the Free Software Foundation; either version 2 of the License, or
9  *   (at your option) any later version.
10  *
11  * This program is largely derived from the Belkin USB Serial Adapter Driver
12  * (see belkin_sa.[ch]). All of the information about the device was acquired
13  * by using SniffUSB on Windows98. For technical details see mct_u232.h.
14  *
15  * William G. Greathouse and Greg Kroah-Hartman provided great help on how to
16  * do the reverse engineering and how to write a USB serial device driver.
17  *
18  * TO BE DONE, TO BE CHECKED:
19  *   DTR/RTS signal handling may be incomplete or incorrect. I have mainly
20  *   implemented what I have seen with SniffUSB or found in belkin_sa.c.
21  *   For further TODOs check also belkin_sa.c.
22  *
23  * TEST STATUS:
24  *   Basic tests have been performed with minicom/zmodem transfers and
25  *   modem dialing under Linux 2.4.0-test10 (for me it works fine).
26  *
27  * 04-Nov-2003 Bill Marr <marr at flex dot com>
28  *   - Mimic Windows driver by sending 2 USB 'device request' messages
29  *     following normal 'baud rate change' message.  This allows data to be
30  *     transmitted to RS-232 devices which don't assert the 'CTS' signal.
31  *
32  * 10-Nov-2001 Wolfgang Grandegger
33  *   - Fixed an endianess problem with the baudrate selection for PowerPC.
34  *
35  * 06-Dec-2001 Martin Hamilton <martinh@gnu.org>
36  *	Added support for the Belkin F5U109 DB9 adaptor
37  *
38  * 30-May-2001 Greg Kroah-Hartman
39  *	switched from using spinlock to a semaphore, which fixes lots of problems.
40  *
41  * 04-May-2001 Stelian Pop
42  *   - Set the maximum bulk output size for Sitecom U232-P25 model to 16 bytes
43  *     instead of the device reported 32 (using 32 bytes causes many data
44  *     loss, Windows driver uses 16 too).
45  *
46  * 02-May-2001 Stelian Pop
47  *   - Fixed the baud calculation for Sitecom U232-P25 model
48  *
49  * 08-Apr-2001 gb
50  *   - Identify version on module load.
51  *
52  * 06-Jan-2001 Cornel Ciocirlan
53  *   - Added support for Sitecom U232-P25 model (Product Id 0x0230)
54  *   - Added support for D-Link DU-H3SP USB BAY (Product Id 0x0200)
55  *
56  * 29-Nov-2000 Greg Kroah-Hartman
57  *   - Added device id table to fit with 2.4.0-test11 structure.
58  *   - took out DEAL_WITH_TWO_INT_IN_ENDPOINTS #define as it's not needed
59  *     (lots of things will change if/when the usb-serial core changes to
60  *     handle these issues.
61  *
62  * 27-Nov-2000 Wolfgang Grandegger
63  *   A version for kernel 2.4.0-test10 released to the Linux community
64  *   (via linux-usb-devel).
65  */
66 
67 #include <linux/config.h>
68 #include <linux/kernel.h>
69 #include <linux/errno.h>
70 #include <linux/init.h>
71 #include <linux/slab.h>
72 #include <linux/tty.h>
73 #include <linux/tty_driver.h>
74 #include <linux/tty_flip.h>
75 #include <linux/module.h>
76 #include <linux/spinlock.h>
77 #include <asm/uaccess.h>
78 #include <linux/usb.h>
79 #include "usb-serial.h"
80 #include "mct_u232.h"
81 
82 /*
83  * Version Information
84  */
85 #define DRIVER_VERSION "z2.0"		/* Linux in-kernel version */
86 #define DRIVER_AUTHOR "Wolfgang Grandegger <wolfgang@ces.ch>"
87 #define DRIVER_DESC "Magic Control Technology USB-RS232 converter driver"
88 
89 static int debug;
90 
91 /*
92  * Function prototypes
93  */
94 static int  mct_u232_startup	         (struct usb_serial *serial);
95 static void mct_u232_shutdown	         (struct usb_serial *serial);
96 static int  mct_u232_open	         (struct usb_serial_port *port,
97 					  struct file *filp);
98 static void mct_u232_close	         (struct usb_serial_port *port,
99 					  struct file *filp);
100 static void mct_u232_read_int_callback   (struct urb *urb, struct pt_regs *regs);
101 static void mct_u232_set_termios         (struct usb_serial_port *port,
102 					  struct termios * old);
103 static int  mct_u232_ioctl	         (struct usb_serial_port *port,
104 					  struct file * file,
105 					  unsigned int cmd,
106 					  unsigned long arg);
107 static void mct_u232_break_ctl	         (struct usb_serial_port *port,
108 					  int break_state );
109 static int  mct_u232_tiocmget		 (struct usb_serial_port *port,
110 					  struct file *file);
111 static int  mct_u232_tiocmset		 (struct usb_serial_port *port,
112 					  struct file *file, unsigned int set,
113 					  unsigned int clear);
114 /*
115  * All of the device info needed for the MCT USB-RS232 converter.
116  */
117 static struct usb_device_id id_table_combined [] = {
118 	{ USB_DEVICE(MCT_U232_VID, MCT_U232_PID) },
119 	{ USB_DEVICE(MCT_U232_VID, MCT_U232_SITECOM_PID) },
120 	{ USB_DEVICE(MCT_U232_VID, MCT_U232_DU_H3SP_PID) },
121 	{ USB_DEVICE(MCT_U232_BELKIN_F5U109_VID, MCT_U232_BELKIN_F5U109_PID) },
122 	{ }		/* Terminating entry */
123 };
124 
125 MODULE_DEVICE_TABLE (usb, id_table_combined);
126 
127 static struct usb_driver mct_u232_driver = {
128 	.owner =	THIS_MODULE,
129 	.name =		"mct_u232",
130 	.probe =	usb_serial_probe,
131 	.disconnect =	usb_serial_disconnect,
132 	.id_table =	id_table_combined,
133 };
134 
135 static struct usb_serial_driver mct_u232_device = {
136 	.driver = {
137 		.owner =	THIS_MODULE,
138 		.name =		"mct_u232",
139 	},
140 	.description =	     "MCT U232",
141 	.id_table =	     id_table_combined,
142 	.num_interrupt_in =  2,
143 	.num_bulk_in =	     0,
144 	.num_bulk_out =	     1,
145 	.num_ports =	     1,
146 	.open =		     mct_u232_open,
147 	.close =	     mct_u232_close,
148 	.read_int_callback = mct_u232_read_int_callback,
149 	.ioctl =	     mct_u232_ioctl,
150 	.set_termios =	     mct_u232_set_termios,
151 	.break_ctl =	     mct_u232_break_ctl,
152 	.tiocmget =	     mct_u232_tiocmget,
153 	.tiocmset =	     mct_u232_tiocmset,
154 	.attach =	     mct_u232_startup,
155 	.shutdown =	     mct_u232_shutdown,
156 };
157 
158 
159 struct mct_u232_private {
160 	spinlock_t lock;
161 	unsigned int	     control_state; /* Modem Line Setting (TIOCM) */
162 	unsigned char        last_lcr;      /* Line Control Register */
163 	unsigned char	     last_lsr;      /* Line Status Register */
164 	unsigned char	     last_msr;      /* Modem Status Register */
165 };
166 
167 /*
168  * Handle vendor specific USB requests
169  */
170 
171 #define WDR_TIMEOUT 5000 /* default urb timeout */
172 
173 /*
174  * Later day 2.6.0-test kernels have new baud rates like B230400 which
175  * we do not know how to support. We ignore them for the moment.
176  * XXX Rate-limit the error message, it's user triggerable.
177  */
178 static int mct_u232_calculate_baud_rate(struct usb_serial *serial, int value)
179 {
180 	if (le16_to_cpu(serial->dev->descriptor.idProduct) == MCT_U232_SITECOM_PID
181 	  || le16_to_cpu(serial->dev->descriptor.idProduct) == MCT_U232_BELKIN_F5U109_PID) {
182 		switch (value) {
183 		case    B300: return 0x01;
184 		case    B600: return 0x02; /* this one not tested */
185 		case   B1200: return 0x03;
186 		case   B2400: return 0x04;
187 		case   B4800: return 0x06;
188 		case   B9600: return 0x08;
189 		case  B19200: return 0x09;
190 		case  B38400: return 0x0a;
191 		case  B57600: return 0x0b;
192 		case B115200: return 0x0c;
193 		default:
194 			err("MCT USB-RS232: unsupported baudrate request 0x%x,"
195 			    " using default of B9600", value);
196 			return 0x08;
197 		}
198 	} else {
199 		switch (value) {
200 		case    B300: value =     300; break;
201 		case    B600: value =     600; break;
202 		case   B1200: value =    1200; break;
203 		case   B2400: value =    2400; break;
204 		case   B4800: value =    4800; break;
205 		case   B9600: value =    9600; break;
206 		case  B19200: value =   19200; break;
207 		case  B38400: value =   38400; break;
208 		case  B57600: value =   57600; break;
209 		case B115200: value =  115200; break;
210 		default:
211 			err("MCT USB-RS232: unsupported baudrate request 0x%x,"
212 			    " using default of B9600", value);
213 			value = 9600;
214 		}
215 		return 115200/value;
216 	}
217 }
218 
219 static int mct_u232_set_baud_rate(struct usb_serial *serial, int value)
220 {
221 	__le32 divisor;
222         int rc;
223         unsigned char zero_byte = 0;
224 
225 	divisor = cpu_to_le32(mct_u232_calculate_baud_rate(serial, value));
226 
227         rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
228                              MCT_U232_SET_BAUD_RATE_REQUEST,
229 			     MCT_U232_SET_REQUEST_TYPE,
230                              0, 0, &divisor, MCT_U232_SET_BAUD_RATE_SIZE,
231 			     WDR_TIMEOUT);
232 	if (rc < 0)
233 		err("Set BAUD RATE %d failed (error = %d)", value, rc);
234 	dbg("set_baud_rate: value: 0x%x, divisor: 0x%x", value, divisor);
235 
236 	/* Mimic the MCT-supplied Windows driver (version 1.21P.0104), which
237 	   always sends two extra USB 'device request' messages after the
238 	   'baud rate change' message.  The actual functionality of the
239 	   request codes in these messages is not fully understood but these
240 	   particular codes are never seen in any operation besides a baud
241 	   rate change.  Both of these messages send a single byte of data
242 	   whose value is always zero.  The second of these two extra messages
243 	   is required in order for data to be properly written to an RS-232
244 	   device which does not assert the 'CTS' signal. */
245 
246 	rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
247 			     MCT_U232_SET_UNKNOWN1_REQUEST,
248 			     MCT_U232_SET_REQUEST_TYPE,
249 			     0, 0, &zero_byte, MCT_U232_SET_UNKNOWN1_SIZE,
250 			     WDR_TIMEOUT);
251 	if (rc < 0)
252 		err("Sending USB device request code %d failed (error = %d)",
253 		    MCT_U232_SET_UNKNOWN1_REQUEST, rc);
254 
255 	rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
256 			     MCT_U232_SET_UNKNOWN2_REQUEST,
257 			     MCT_U232_SET_REQUEST_TYPE,
258 			     0, 0, &zero_byte, MCT_U232_SET_UNKNOWN2_SIZE,
259 			     WDR_TIMEOUT);
260 	if (rc < 0)
261 		err("Sending USB device request code %d failed (error = %d)",
262 		    MCT_U232_SET_UNKNOWN2_REQUEST, rc);
263 
264         return rc;
265 } /* mct_u232_set_baud_rate */
266 
267 static int mct_u232_set_line_ctrl(struct usb_serial *serial, unsigned char lcr)
268 {
269         int rc;
270         rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
271                              MCT_U232_SET_LINE_CTRL_REQUEST,
272 			     MCT_U232_SET_REQUEST_TYPE,
273                              0, 0, &lcr, MCT_U232_SET_LINE_CTRL_SIZE,
274 			     WDR_TIMEOUT);
275 	if (rc < 0)
276 		err("Set LINE CTRL 0x%x failed (error = %d)", lcr, rc);
277 	dbg("set_line_ctrl: 0x%x", lcr);
278         return rc;
279 } /* mct_u232_set_line_ctrl */
280 
281 static int mct_u232_set_modem_ctrl(struct usb_serial *serial,
282 				   unsigned int control_state)
283 {
284         int rc;
285 	unsigned char mcr = MCT_U232_MCR_NONE;
286 
287 	if (control_state & TIOCM_DTR)
288 		mcr |= MCT_U232_MCR_DTR;
289 	if (control_state & TIOCM_RTS)
290 		mcr |= MCT_U232_MCR_RTS;
291 
292         rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
293                              MCT_U232_SET_MODEM_CTRL_REQUEST,
294 			     MCT_U232_SET_REQUEST_TYPE,
295                              0, 0, &mcr, MCT_U232_SET_MODEM_CTRL_SIZE,
296 			     WDR_TIMEOUT);
297 	if (rc < 0)
298 		err("Set MODEM CTRL 0x%x failed (error = %d)", mcr, rc);
299 	dbg("set_modem_ctrl: state=0x%x ==> mcr=0x%x", control_state, mcr);
300 
301         return rc;
302 } /* mct_u232_set_modem_ctrl */
303 
304 static int mct_u232_get_modem_stat(struct usb_serial *serial, unsigned char *msr)
305 {
306         int rc;
307         rc = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
308                              MCT_U232_GET_MODEM_STAT_REQUEST,
309 			     MCT_U232_GET_REQUEST_TYPE,
310                              0, 0, msr, MCT_U232_GET_MODEM_STAT_SIZE,
311 			     WDR_TIMEOUT);
312 	if (rc < 0) {
313 		err("Get MODEM STATus failed (error = %d)", rc);
314 		*msr = 0;
315 	}
316 	dbg("get_modem_stat: 0x%x", *msr);
317         return rc;
318 } /* mct_u232_get_modem_stat */
319 
320 static void mct_u232_msr_to_state(unsigned int *control_state, unsigned char msr)
321 {
322  	/* Translate Control Line states */
323 	if (msr & MCT_U232_MSR_DSR)
324 		*control_state |=  TIOCM_DSR;
325 	else
326 		*control_state &= ~TIOCM_DSR;
327 	if (msr & MCT_U232_MSR_CTS)
328 		*control_state |=  TIOCM_CTS;
329 	else
330 		*control_state &= ~TIOCM_CTS;
331 	if (msr & MCT_U232_MSR_RI)
332 		*control_state |=  TIOCM_RI;
333 	else
334 		*control_state &= ~TIOCM_RI;
335 	if (msr & MCT_U232_MSR_CD)
336 		*control_state |=  TIOCM_CD;
337 	else
338 		*control_state &= ~TIOCM_CD;
339  	dbg("msr_to_state: msr=0x%x ==> state=0x%x", msr, *control_state);
340 } /* mct_u232_msr_to_state */
341 
342 /*
343  * Driver's tty interface functions
344  */
345 
346 static int mct_u232_startup (struct usb_serial *serial)
347 {
348 	struct mct_u232_private *priv;
349 	struct usb_serial_port *port, *rport;
350 
351 	priv = kmalloc(sizeof(struct mct_u232_private), GFP_KERNEL);
352 	if (!priv)
353 		return -ENOMEM;
354 	memset(priv, 0, sizeof(struct mct_u232_private));
355 	spin_lock_init(&priv->lock);
356 	usb_set_serial_port_data(serial->port[0], priv);
357 
358 	init_waitqueue_head(&serial->port[0]->write_wait);
359 
360 	/* Puh, that's dirty */
361 	port = serial->port[0];
362 	rport = serial->port[1];
363 	if (port->read_urb) {
364 		/* No unlinking, it wasn't submitted yet. */
365 		usb_free_urb(port->read_urb);
366 	}
367 	port->read_urb = rport->interrupt_in_urb;
368 	rport->interrupt_in_urb = NULL;
369 	port->read_urb->context = port;
370 
371 	return (0);
372 } /* mct_u232_startup */
373 
374 
375 static void mct_u232_shutdown (struct usb_serial *serial)
376 {
377 	struct mct_u232_private *priv;
378 	int i;
379 
380 	dbg("%s", __FUNCTION__);
381 
382 	for (i=0; i < serial->num_ports; ++i) {
383 		/* My special items, the standard routines free my urbs */
384 		priv = usb_get_serial_port_data(serial->port[i]);
385 		if (priv) {
386 			usb_set_serial_port_data(serial->port[i], NULL);
387 			kfree(priv);
388 		}
389 	}
390 } /* mct_u232_shutdown */
391 
392 static int  mct_u232_open (struct usb_serial_port *port, struct file *filp)
393 {
394 	struct usb_serial *serial = port->serial;
395 	struct mct_u232_private *priv = usb_get_serial_port_data(port);
396 	int retval = 0;
397 	unsigned int control_state;
398 	unsigned long flags;
399 	unsigned char last_lcr;
400 	unsigned char last_msr;
401 
402 	dbg("%s port %d", __FUNCTION__, port->number);
403 
404 	/* Compensate for a hardware bug: although the Sitecom U232-P25
405 	 * device reports a maximum output packet size of 32 bytes,
406 	 * it seems to be able to accept only 16 bytes (and that's what
407 	 * SniffUSB says too...)
408 	 */
409 	if (le16_to_cpu(serial->dev->descriptor.idProduct) == MCT_U232_SITECOM_PID)
410 		port->bulk_out_size = 16;
411 
412 	/* Do a defined restart: the normal serial device seems to
413 	 * always turn on DTR and RTS here, so do the same. I'm not
414 	 * sure if this is really necessary. But it should not harm
415 	 * either.
416 	 */
417 	spin_lock_irqsave(&priv->lock, flags);
418 	if (port->tty->termios->c_cflag & CBAUD)
419 		priv->control_state = TIOCM_DTR | TIOCM_RTS;
420 	else
421 		priv->control_state = 0;
422 
423 	priv->last_lcr = (MCT_U232_DATA_BITS_8 |
424 			  MCT_U232_PARITY_NONE |
425 			  MCT_U232_STOP_BITS_1);
426 	control_state = priv->control_state;
427 	last_lcr = priv->last_lcr;
428 	spin_unlock_irqrestore(&priv->lock, flags);
429 	mct_u232_set_modem_ctrl(serial, control_state);
430 	mct_u232_set_line_ctrl(serial, last_lcr);
431 
432 	/* Read modem status and update control state */
433 	mct_u232_get_modem_stat(serial, &last_msr);
434 	spin_lock_irqsave(&priv->lock, flags);
435 	priv->last_msr = last_msr;
436 	mct_u232_msr_to_state(&priv->control_state, priv->last_msr);
437 	spin_unlock_irqrestore(&priv->lock, flags);
438 
439 	port->read_urb->dev = port->serial->dev;
440 	retval = usb_submit_urb(port->read_urb, GFP_KERNEL);
441 	if (retval) {
442 		err("usb_submit_urb(read bulk) failed pipe 0x%x err %d",
443 		    port->read_urb->pipe, retval);
444 		goto exit;
445 	}
446 
447 	port->interrupt_in_urb->dev = port->serial->dev;
448 	retval = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
449 	if (retval)
450 		err(" usb_submit_urb(read int) failed pipe 0x%x err %d",
451 		    port->interrupt_in_urb->pipe, retval);
452 
453 exit:
454 	return 0;
455 } /* mct_u232_open */
456 
457 
458 static void mct_u232_close (struct usb_serial_port *port, struct file *filp)
459 {
460 	dbg("%s port %d", __FUNCTION__, port->number);
461 
462 	if (port->serial->dev) {
463 		/* shutdown our urbs */
464 		usb_kill_urb(port->write_urb);
465 		usb_kill_urb(port->read_urb);
466 		usb_kill_urb(port->interrupt_in_urb);
467 	}
468 } /* mct_u232_close */
469 
470 
471 static void mct_u232_read_int_callback (struct urb *urb, struct pt_regs *regs)
472 {
473 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
474 	struct mct_u232_private *priv = usb_get_serial_port_data(port);
475 	struct usb_serial *serial = port->serial;
476 	struct tty_struct *tty;
477 	unsigned char *data = urb->transfer_buffer;
478 	int status;
479 	unsigned long flags;
480 
481 	switch (urb->status) {
482 	case 0:
483 		/* success */
484 		break;
485 	case -ECONNRESET:
486 	case -ENOENT:
487 	case -ESHUTDOWN:
488 		/* this urb is terminated, clean up */
489 		dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
490 		return;
491 	default:
492 		dbg("%s - nonzero urb status received: %d", __FUNCTION__, urb->status);
493 		goto exit;
494 	}
495 
496 	if (!serial) {
497 		dbg("%s - bad serial pointer, exiting", __FUNCTION__);
498 		return;
499 	}
500 
501         dbg("%s - port %d", __FUNCTION__, port->number);
502 	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
503 
504 	/*
505 	 * Work-a-round: handle the 'usual' bulk-in pipe here
506 	 */
507 	if (urb->transfer_buffer_length > 2) {
508 		int i;
509 		tty = port->tty;
510 		if (urb->actual_length) {
511 			for (i = 0; i < urb->actual_length ; ++i) {
512 				tty_insert_flip_char(tty, data[i], 0);
513 			}
514 			tty_flip_buffer_push(tty);
515 		}
516 		goto exit;
517 	}
518 
519 	/*
520 	 * The interrupt-in pipe signals exceptional conditions (modem line
521 	 * signal changes and errors). data[0] holds MSR, data[1] holds LSR.
522 	 */
523 	spin_lock_irqsave(&priv->lock, flags);
524 	priv->last_msr = data[MCT_U232_MSR_INDEX];
525 
526 	/* Record Control Line states */
527 	mct_u232_msr_to_state(&priv->control_state, priv->last_msr);
528 
529 #if 0
530 	/* Not yet handled. See belin_sa.c for further information */
531 	/* Now to report any errors */
532 	priv->last_lsr = data[MCT_U232_LSR_INDEX];
533 	/*
534 	 * fill in the flip buffer here, but I do not know the relation
535 	 * to the current/next receive buffer or characters.  I need
536 	 * to look in to this before committing any code.
537 	 */
538 	if (priv->last_lsr & MCT_U232_LSR_ERR) {
539 		tty = port->tty;
540 		/* Overrun Error */
541 		if (priv->last_lsr & MCT_U232_LSR_OE) {
542 		}
543 		/* Parity Error */
544 		if (priv->last_lsr & MCT_U232_LSR_PE) {
545 		}
546 		/* Framing Error */
547 		if (priv->last_lsr & MCT_U232_LSR_FE) {
548 		}
549 		/* Break Indicator */
550 		if (priv->last_lsr & MCT_U232_LSR_BI) {
551 		}
552 	}
553 #endif
554 	spin_unlock_irqrestore(&priv->lock, flags);
555 exit:
556 	status = usb_submit_urb (urb, GFP_ATOMIC);
557 	if (status)
558 		err ("%s - usb_submit_urb failed with result %d",
559 		     __FUNCTION__, status);
560 } /* mct_u232_read_int_callback */
561 
562 static void mct_u232_set_termios (struct usb_serial_port *port,
563 				  struct termios *old_termios)
564 {
565 	struct usb_serial *serial = port->serial;
566 	struct mct_u232_private *priv = usb_get_serial_port_data(port);
567 	unsigned int iflag = port->tty->termios->c_iflag;
568 	unsigned int cflag = port->tty->termios->c_cflag;
569 	unsigned int old_cflag = old_termios->c_cflag;
570 	unsigned long flags;
571 	unsigned int control_state, new_state;
572 	unsigned char last_lcr;
573 
574 	/* get a local copy of the current port settings */
575 	spin_lock_irqsave(&priv->lock, flags);
576 	control_state = priv->control_state;
577 	spin_unlock_irqrestore(&priv->lock, flags);
578 	last_lcr = 0;
579 
580 	/*
581 	 * Update baud rate.
582 	 * Do not attempt to cache old rates and skip settings,
583 	 * disconnects screw such tricks up completely.
584 	 * Premature optimization is the root of all evil.
585 	 */
586 
587         /* reassert DTR and (maybe) RTS on transition from B0 */
588 	if ((old_cflag & CBAUD) == B0) {
589 		dbg("%s: baud was B0", __FUNCTION__);
590 		control_state |= TIOCM_DTR;
591 		/* don't set RTS if using hardware flow control */
592 		if (!(old_cflag & CRTSCTS)) {
593 			control_state |= TIOCM_RTS;
594 		}
595 		mct_u232_set_modem_ctrl(serial, control_state);
596 	}
597 
598 	mct_u232_set_baud_rate(serial, cflag & CBAUD);
599 
600 	if ((cflag & CBAUD) == B0 ) {
601 		dbg("%s: baud is B0", __FUNCTION__);
602 		/* Drop RTS and DTR */
603 		control_state &= ~(TIOCM_DTR | TIOCM_RTS);
604        		mct_u232_set_modem_ctrl(serial, control_state);
605 	}
606 
607 	/*
608 	 * Update line control register (LCR)
609 	 */
610 
611 	/* set the parity */
612 	if (cflag & PARENB)
613 		last_lcr |= (cflag & PARODD) ?
614 			MCT_U232_PARITY_ODD : MCT_U232_PARITY_EVEN;
615 	else
616 		last_lcr |= MCT_U232_PARITY_NONE;
617 
618 	/* set the number of data bits */
619 	switch (cflag & CSIZE) {
620 	case CS5:
621 		last_lcr |= MCT_U232_DATA_BITS_5; break;
622 	case CS6:
623 		last_lcr |= MCT_U232_DATA_BITS_6; break;
624 	case CS7:
625 		last_lcr |= MCT_U232_DATA_BITS_7; break;
626 	case CS8:
627 		last_lcr |= MCT_U232_DATA_BITS_8; break;
628 	default:
629 		err("CSIZE was not CS5-CS8, using default of 8");
630 		last_lcr |= MCT_U232_DATA_BITS_8;
631 		break;
632 	}
633 
634 	/* set the number of stop bits */
635 	last_lcr |= (cflag & CSTOPB) ?
636 		MCT_U232_STOP_BITS_2 : MCT_U232_STOP_BITS_1;
637 
638 	mct_u232_set_line_ctrl(serial, last_lcr);
639 
640 	/*
641 	 * Set flow control: well, I do not really now how to handle DTR/RTS.
642 	 * Just do what we have seen with SniffUSB on Win98.
643 	 */
644 	/* Drop DTR/RTS if no flow control otherwise assert */
645 	new_state = control_state;
646 	if ((iflag & IXOFF) || (iflag & IXON) || (cflag & CRTSCTS))
647 		new_state |= TIOCM_DTR | TIOCM_RTS;
648 	else
649 		new_state &= ~(TIOCM_DTR | TIOCM_RTS);
650 	if (new_state != control_state) {
651 		mct_u232_set_modem_ctrl(serial, new_state);
652 		control_state = new_state;
653 	}
654 
655 	/* save off the modified port settings */
656 	spin_lock_irqsave(&priv->lock, flags);
657 	priv->control_state = control_state;
658 	priv->last_lcr = last_lcr;
659 	spin_unlock_irqrestore(&priv->lock, flags);
660 } /* mct_u232_set_termios */
661 
662 static void mct_u232_break_ctl( struct usb_serial_port *port, int break_state )
663 {
664 	struct usb_serial *serial = port->serial;
665 	struct mct_u232_private *priv = usb_get_serial_port_data(port);
666 	unsigned char lcr;
667 	unsigned long flags;
668 
669 	dbg("%sstate=%d", __FUNCTION__, break_state);
670 
671 	spin_lock_irqsave(&priv->lock, flags);
672 	lcr = priv->last_lcr;
673 	spin_unlock_irqrestore(&priv->lock, flags);
674 
675 	if (break_state)
676 		lcr |= MCT_U232_SET_BREAK;
677 
678 	mct_u232_set_line_ctrl(serial, lcr);
679 } /* mct_u232_break_ctl */
680 
681 
682 static int mct_u232_tiocmget (struct usb_serial_port *port, struct file *file)
683 {
684 	struct mct_u232_private *priv = usb_get_serial_port_data(port);
685 	unsigned int control_state;
686 	unsigned long flags;
687 
688 	dbg("%s", __FUNCTION__);
689 
690 	spin_lock_irqsave(&priv->lock, flags);
691 	control_state = priv->control_state;
692 	spin_unlock_irqrestore(&priv->lock, flags);
693 
694 	return control_state;
695 }
696 
697 static int mct_u232_tiocmset (struct usb_serial_port *port, struct file *file,
698 			      unsigned int set, unsigned int clear)
699 {
700 	struct usb_serial *serial = port->serial;
701 	struct mct_u232_private *priv = usb_get_serial_port_data(port);
702 	unsigned int control_state;
703 	unsigned long flags;
704 
705 	dbg("%s", __FUNCTION__);
706 
707 	spin_lock_irqsave(&priv->lock, flags);
708 	control_state = priv->control_state;
709 
710 	if (set & TIOCM_RTS)
711 		control_state |= TIOCM_RTS;
712 	if (set & TIOCM_DTR)
713 		control_state |= TIOCM_DTR;
714 	if (clear & TIOCM_RTS)
715 		control_state &= ~TIOCM_RTS;
716 	if (clear & TIOCM_DTR)
717 		control_state &= ~TIOCM_DTR;
718 
719 	priv->control_state = control_state;
720 	spin_unlock_irqrestore(&priv->lock, flags);
721 	return mct_u232_set_modem_ctrl(serial, control_state);
722 }
723 
724 static int mct_u232_ioctl (struct usb_serial_port *port, struct file * file,
725 			   unsigned int cmd, unsigned long arg)
726 {
727 	dbg("%scmd=0x%x", __FUNCTION__, cmd);
728 
729 	/* Based on code from acm.c and others */
730 	switch (cmd) {
731 	case TIOCMIWAIT:
732 		/* wait for any of the 4 modem inputs (DCD,RI,DSR,CTS)*/
733 		/* TODO */
734 		return( 0 );
735 
736 	case TIOCGICOUNT:
737 		/* return count of modemline transitions */
738 		/* TODO */
739 		return 0;
740 
741 	default:
742 		dbg("%s: arg not supported - 0x%04x", __FUNCTION__,cmd);
743 		return(-ENOIOCTLCMD);
744 		break;
745 	}
746 	return 0;
747 } /* mct_u232_ioctl */
748 
749 
750 static int __init mct_u232_init (void)
751 {
752 	int retval;
753 	retval = usb_serial_register(&mct_u232_device);
754 	if (retval)
755 		goto failed_usb_serial_register;
756 	retval = usb_register(&mct_u232_driver);
757 	if (retval)
758 		goto failed_usb_register;
759 	info(DRIVER_DESC " " DRIVER_VERSION);
760 	return 0;
761 failed_usb_register:
762 	usb_serial_deregister(&mct_u232_device);
763 failed_usb_serial_register:
764 	return retval;
765 }
766 
767 
768 static void __exit mct_u232_exit (void)
769 {
770 	usb_deregister (&mct_u232_driver);
771 	usb_serial_deregister (&mct_u232_device);
772 }
773 
774 
775 module_init (mct_u232_init);
776 module_exit(mct_u232_exit);
777 
778 MODULE_AUTHOR( DRIVER_AUTHOR );
779 MODULE_DESCRIPTION( DRIVER_DESC );
780 MODULE_LICENSE("GPL");
781 
782 module_param(debug, bool, S_IRUGO | S_IWUSR);
783 MODULE_PARM_DESC(debug, "Debug enabled or not");
784