xref: /linux/drivers/usb/serial/mct_u232.c (revision b0148a98ec5151fec82064d95f11eb9efbc628ea)
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/kernel.h>
68 #include <linux/errno.h>
69 #include <linux/init.h>
70 #include <linux/slab.h>
71 #include <linux/tty.h>
72 #include <linux/tty_driver.h>
73 #include <linux/tty_flip.h>
74 #include <linux/module.h>
75 #include <linux/spinlock.h>
76 #include <asm/uaccess.h>
77 #include <linux/usb.h>
78 #include <linux/usb/serial.h>
79 #include "mct_u232.h"
80 
81 /*
82  * Version Information
83  */
84 #define DRIVER_VERSION "z2.0"		/* Linux in-kernel version */
85 #define DRIVER_AUTHOR "Wolfgang Grandegger <wolfgang@ces.ch>"
86 #define DRIVER_DESC "Magic Control Technology USB-RS232 converter driver"
87 
88 static int debug;
89 
90 /*
91  * Function prototypes
92  */
93 static int  mct_u232_startup	         (struct usb_serial *serial);
94 static void mct_u232_shutdown	         (struct usb_serial *serial);
95 static int  mct_u232_open	         (struct usb_serial_port *port,
96 					  struct file *filp);
97 static void mct_u232_close	         (struct usb_serial_port *port,
98 					  struct file *filp);
99 static void mct_u232_read_int_callback   (struct urb *urb);
100 static void mct_u232_set_termios         (struct usb_serial_port *port,
101 					  struct ktermios * old);
102 static int  mct_u232_ioctl	         (struct usb_serial_port *port,
103 					  struct file * file,
104 					  unsigned int cmd,
105 					  unsigned long arg);
106 static void mct_u232_break_ctl	         (struct usb_serial_port *port,
107 					  int break_state );
108 static int  mct_u232_tiocmget		 (struct usb_serial_port *port,
109 					  struct file *file);
110 static int  mct_u232_tiocmset		 (struct usb_serial_port *port,
111 					  struct file *file, unsigned int set,
112 					  unsigned int clear);
113 /*
114  * All of the device info needed for the MCT USB-RS232 converter.
115  */
116 static struct usb_device_id id_table_combined [] = {
117 	{ USB_DEVICE(MCT_U232_VID, MCT_U232_PID) },
118 	{ USB_DEVICE(MCT_U232_VID, MCT_U232_SITECOM_PID) },
119 	{ USB_DEVICE(MCT_U232_VID, MCT_U232_DU_H3SP_PID) },
120 	{ USB_DEVICE(MCT_U232_BELKIN_F5U109_VID, MCT_U232_BELKIN_F5U109_PID) },
121 	{ }		/* Terminating entry */
122 };
123 
124 MODULE_DEVICE_TABLE (usb, id_table_combined);
125 
126 static struct usb_driver mct_u232_driver = {
127 	.name =		"mct_u232",
128 	.probe =	usb_serial_probe,
129 	.disconnect =	usb_serial_disconnect,
130 	.id_table =	id_table_combined,
131 	.no_dynamic_id = 	1,
132 };
133 
134 static struct usb_serial_driver mct_u232_device = {
135 	.driver = {
136 		.owner =	THIS_MODULE,
137 		.name =		"mct_u232",
138 	},
139 	.description =	     "MCT U232",
140 	.usb_driver = 	     &mct_u232_driver,
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 = kzalloc(sizeof(struct mct_u232_private), GFP_KERNEL);
352 	if (!priv)
353 		return -ENOMEM;
354 	spin_lock_init(&priv->lock);
355 	usb_set_serial_port_data(serial->port[0], priv);
356 
357 	init_waitqueue_head(&serial->port[0]->write_wait);
358 
359 	/* Puh, that's dirty */
360 	port = serial->port[0];
361 	rport = serial->port[1];
362 	/* No unlinking, it wasn't submitted yet. */
363 	usb_free_urb(port->read_urb);
364 	port->read_urb = rport->interrupt_in_urb;
365 	rport->interrupt_in_urb = NULL;
366 	port->read_urb->context = port;
367 
368 	return (0);
369 } /* mct_u232_startup */
370 
371 
372 static void mct_u232_shutdown (struct usb_serial *serial)
373 {
374 	struct mct_u232_private *priv;
375 	int i;
376 
377 	dbg("%s", __FUNCTION__);
378 
379 	for (i=0; i < serial->num_ports; ++i) {
380 		/* My special items, the standard routines free my urbs */
381 		priv = usb_get_serial_port_data(serial->port[i]);
382 		if (priv) {
383 			usb_set_serial_port_data(serial->port[i], NULL);
384 			kfree(priv);
385 		}
386 	}
387 } /* mct_u232_shutdown */
388 
389 static int  mct_u232_open (struct usb_serial_port *port, struct file *filp)
390 {
391 	struct usb_serial *serial = port->serial;
392 	struct mct_u232_private *priv = usb_get_serial_port_data(port);
393 	int retval = 0;
394 	unsigned int control_state;
395 	unsigned long flags;
396 	unsigned char last_lcr;
397 	unsigned char last_msr;
398 
399 	dbg("%s port %d", __FUNCTION__, port->number);
400 
401 	/* Compensate for a hardware bug: although the Sitecom U232-P25
402 	 * device reports a maximum output packet size of 32 bytes,
403 	 * it seems to be able to accept only 16 bytes (and that's what
404 	 * SniffUSB says too...)
405 	 */
406 	if (le16_to_cpu(serial->dev->descriptor.idProduct) == MCT_U232_SITECOM_PID)
407 		port->bulk_out_size = 16;
408 
409 	/* Do a defined restart: the normal serial device seems to
410 	 * always turn on DTR and RTS here, so do the same. I'm not
411 	 * sure if this is really necessary. But it should not harm
412 	 * either.
413 	 */
414 	spin_lock_irqsave(&priv->lock, flags);
415 	if (port->tty->termios->c_cflag & CBAUD)
416 		priv->control_state = TIOCM_DTR | TIOCM_RTS;
417 	else
418 		priv->control_state = 0;
419 
420 	priv->last_lcr = (MCT_U232_DATA_BITS_8 |
421 			  MCT_U232_PARITY_NONE |
422 			  MCT_U232_STOP_BITS_1);
423 	control_state = priv->control_state;
424 	last_lcr = priv->last_lcr;
425 	spin_unlock_irqrestore(&priv->lock, flags);
426 	mct_u232_set_modem_ctrl(serial, control_state);
427 	mct_u232_set_line_ctrl(serial, last_lcr);
428 
429 	/* Read modem status and update control state */
430 	mct_u232_get_modem_stat(serial, &last_msr);
431 	spin_lock_irqsave(&priv->lock, flags);
432 	priv->last_msr = last_msr;
433 	mct_u232_msr_to_state(&priv->control_state, priv->last_msr);
434 	spin_unlock_irqrestore(&priv->lock, flags);
435 
436 	port->read_urb->dev = port->serial->dev;
437 	retval = usb_submit_urb(port->read_urb, GFP_KERNEL);
438 	if (retval) {
439 		err("usb_submit_urb(read bulk) failed pipe 0x%x err %d",
440 		    port->read_urb->pipe, retval);
441 		goto exit;
442 	}
443 
444 	port->interrupt_in_urb->dev = port->serial->dev;
445 	retval = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
446 	if (retval)
447 		err(" usb_submit_urb(read int) failed pipe 0x%x err %d",
448 		    port->interrupt_in_urb->pipe, retval);
449 
450 exit:
451 	return 0;
452 } /* mct_u232_open */
453 
454 
455 static void mct_u232_close (struct usb_serial_port *port, struct file *filp)
456 {
457 	dbg("%s port %d", __FUNCTION__, port->number);
458 
459 	if (port->serial->dev) {
460 		/* shutdown our urbs */
461 		usb_kill_urb(port->write_urb);
462 		usb_kill_urb(port->read_urb);
463 		usb_kill_urb(port->interrupt_in_urb);
464 	}
465 } /* mct_u232_close */
466 
467 
468 static void mct_u232_read_int_callback (struct urb *urb)
469 {
470 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
471 	struct mct_u232_private *priv = usb_get_serial_port_data(port);
472 	struct usb_serial *serial = port->serial;
473 	struct tty_struct *tty;
474 	unsigned char *data = urb->transfer_buffer;
475 	int status;
476 	unsigned long flags;
477 
478 	switch (urb->status) {
479 	case 0:
480 		/* success */
481 		break;
482 	case -ECONNRESET:
483 	case -ENOENT:
484 	case -ESHUTDOWN:
485 		/* this urb is terminated, clean up */
486 		dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
487 		return;
488 	default:
489 		dbg("%s - nonzero urb status received: %d", __FUNCTION__, urb->status);
490 		goto exit;
491 	}
492 
493 	if (!serial) {
494 		dbg("%s - bad serial pointer, exiting", __FUNCTION__);
495 		return;
496 	}
497 
498         dbg("%s - port %d", __FUNCTION__, port->number);
499 	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
500 
501 	/*
502 	 * Work-a-round: handle the 'usual' bulk-in pipe here
503 	 */
504 	if (urb->transfer_buffer_length > 2) {
505 		int i;
506 		tty = port->tty;
507 		if (urb->actual_length) {
508 			for (i = 0; i < urb->actual_length ; ++i) {
509 				tty_insert_flip_char(tty, data[i], 0);
510 			}
511 			tty_flip_buffer_push(tty);
512 		}
513 		goto exit;
514 	}
515 
516 	/*
517 	 * The interrupt-in pipe signals exceptional conditions (modem line
518 	 * signal changes and errors). data[0] holds MSR, data[1] holds LSR.
519 	 */
520 	spin_lock_irqsave(&priv->lock, flags);
521 	priv->last_msr = data[MCT_U232_MSR_INDEX];
522 
523 	/* Record Control Line states */
524 	mct_u232_msr_to_state(&priv->control_state, priv->last_msr);
525 
526 #if 0
527 	/* Not yet handled. See belin_sa.c for further information */
528 	/* Now to report any errors */
529 	priv->last_lsr = data[MCT_U232_LSR_INDEX];
530 	/*
531 	 * fill in the flip buffer here, but I do not know the relation
532 	 * to the current/next receive buffer or characters.  I need
533 	 * to look in to this before committing any code.
534 	 */
535 	if (priv->last_lsr & MCT_U232_LSR_ERR) {
536 		tty = port->tty;
537 		/* Overrun Error */
538 		if (priv->last_lsr & MCT_U232_LSR_OE) {
539 		}
540 		/* Parity Error */
541 		if (priv->last_lsr & MCT_U232_LSR_PE) {
542 		}
543 		/* Framing Error */
544 		if (priv->last_lsr & MCT_U232_LSR_FE) {
545 		}
546 		/* Break Indicator */
547 		if (priv->last_lsr & MCT_U232_LSR_BI) {
548 		}
549 	}
550 #endif
551 	spin_unlock_irqrestore(&priv->lock, flags);
552 exit:
553 	status = usb_submit_urb (urb, GFP_ATOMIC);
554 	if (status)
555 		err ("%s - usb_submit_urb failed with result %d",
556 		     __FUNCTION__, status);
557 } /* mct_u232_read_int_callback */
558 
559 static void mct_u232_set_termios (struct usb_serial_port *port,
560 				  struct ktermios *old_termios)
561 {
562 	struct usb_serial *serial = port->serial;
563 	struct mct_u232_private *priv = usb_get_serial_port_data(port);
564 	unsigned int iflag = port->tty->termios->c_iflag;
565 	unsigned int cflag = port->tty->termios->c_cflag;
566 	unsigned int old_cflag = old_termios->c_cflag;
567 	unsigned long flags;
568 	unsigned int control_state, new_state;
569 	unsigned char last_lcr;
570 
571 	/* get a local copy of the current port settings */
572 	spin_lock_irqsave(&priv->lock, flags);
573 	control_state = priv->control_state;
574 	spin_unlock_irqrestore(&priv->lock, flags);
575 	last_lcr = 0;
576 
577 	/*
578 	 * Update baud rate.
579 	 * Do not attempt to cache old rates and skip settings,
580 	 * disconnects screw such tricks up completely.
581 	 * Premature optimization is the root of all evil.
582 	 */
583 
584         /* reassert DTR and (maybe) RTS on transition from B0 */
585 	if ((old_cflag & CBAUD) == B0) {
586 		dbg("%s: baud was B0", __FUNCTION__);
587 		control_state |= TIOCM_DTR;
588 		/* don't set RTS if using hardware flow control */
589 		if (!(old_cflag & CRTSCTS)) {
590 			control_state |= TIOCM_RTS;
591 		}
592 		mct_u232_set_modem_ctrl(serial, control_state);
593 	}
594 
595 	mct_u232_set_baud_rate(serial, cflag & CBAUD);
596 
597 	if ((cflag & CBAUD) == B0 ) {
598 		dbg("%s: baud is B0", __FUNCTION__);
599 		/* Drop RTS and DTR */
600 		control_state &= ~(TIOCM_DTR | TIOCM_RTS);
601        		mct_u232_set_modem_ctrl(serial, control_state);
602 	}
603 
604 	/*
605 	 * Update line control register (LCR)
606 	 */
607 
608 	/* set the parity */
609 	if (cflag & PARENB)
610 		last_lcr |= (cflag & PARODD) ?
611 			MCT_U232_PARITY_ODD : MCT_U232_PARITY_EVEN;
612 	else
613 		last_lcr |= MCT_U232_PARITY_NONE;
614 
615 	/* set the number of data bits */
616 	switch (cflag & CSIZE) {
617 	case CS5:
618 		last_lcr |= MCT_U232_DATA_BITS_5; break;
619 	case CS6:
620 		last_lcr |= MCT_U232_DATA_BITS_6; break;
621 	case CS7:
622 		last_lcr |= MCT_U232_DATA_BITS_7; break;
623 	case CS8:
624 		last_lcr |= MCT_U232_DATA_BITS_8; break;
625 	default:
626 		err("CSIZE was not CS5-CS8, using default of 8");
627 		last_lcr |= MCT_U232_DATA_BITS_8;
628 		break;
629 	}
630 
631 	/* set the number of stop bits */
632 	last_lcr |= (cflag & CSTOPB) ?
633 		MCT_U232_STOP_BITS_2 : MCT_U232_STOP_BITS_1;
634 
635 	mct_u232_set_line_ctrl(serial, last_lcr);
636 
637 	/*
638 	 * Set flow control: well, I do not really now how to handle DTR/RTS.
639 	 * Just do what we have seen with SniffUSB on Win98.
640 	 */
641 	/* Drop DTR/RTS if no flow control otherwise assert */
642 	new_state = control_state;
643 	if ((iflag & IXOFF) || (iflag & IXON) || (cflag & CRTSCTS))
644 		new_state |= TIOCM_DTR | TIOCM_RTS;
645 	else
646 		new_state &= ~(TIOCM_DTR | TIOCM_RTS);
647 	if (new_state != control_state) {
648 		mct_u232_set_modem_ctrl(serial, new_state);
649 		control_state = new_state;
650 	}
651 
652 	/* save off the modified port settings */
653 	spin_lock_irqsave(&priv->lock, flags);
654 	priv->control_state = control_state;
655 	priv->last_lcr = last_lcr;
656 	spin_unlock_irqrestore(&priv->lock, flags);
657 } /* mct_u232_set_termios */
658 
659 static void mct_u232_break_ctl( struct usb_serial_port *port, int break_state )
660 {
661 	struct usb_serial *serial = port->serial;
662 	struct mct_u232_private *priv = usb_get_serial_port_data(port);
663 	unsigned char lcr;
664 	unsigned long flags;
665 
666 	dbg("%sstate=%d", __FUNCTION__, break_state);
667 
668 	spin_lock_irqsave(&priv->lock, flags);
669 	lcr = priv->last_lcr;
670 	spin_unlock_irqrestore(&priv->lock, flags);
671 
672 	if (break_state)
673 		lcr |= MCT_U232_SET_BREAK;
674 
675 	mct_u232_set_line_ctrl(serial, lcr);
676 } /* mct_u232_break_ctl */
677 
678 
679 static int mct_u232_tiocmget (struct usb_serial_port *port, struct file *file)
680 {
681 	struct mct_u232_private *priv = usb_get_serial_port_data(port);
682 	unsigned int control_state;
683 	unsigned long flags;
684 
685 	dbg("%s", __FUNCTION__);
686 
687 	spin_lock_irqsave(&priv->lock, flags);
688 	control_state = priv->control_state;
689 	spin_unlock_irqrestore(&priv->lock, flags);
690 
691 	return control_state;
692 }
693 
694 static int mct_u232_tiocmset (struct usb_serial_port *port, struct file *file,
695 			      unsigned int set, unsigned int clear)
696 {
697 	struct usb_serial *serial = port->serial;
698 	struct mct_u232_private *priv = usb_get_serial_port_data(port);
699 	unsigned int control_state;
700 	unsigned long flags;
701 
702 	dbg("%s", __FUNCTION__);
703 
704 	spin_lock_irqsave(&priv->lock, flags);
705 	control_state = priv->control_state;
706 
707 	if (set & TIOCM_RTS)
708 		control_state |= TIOCM_RTS;
709 	if (set & TIOCM_DTR)
710 		control_state |= TIOCM_DTR;
711 	if (clear & TIOCM_RTS)
712 		control_state &= ~TIOCM_RTS;
713 	if (clear & TIOCM_DTR)
714 		control_state &= ~TIOCM_DTR;
715 
716 	priv->control_state = control_state;
717 	spin_unlock_irqrestore(&priv->lock, flags);
718 	return mct_u232_set_modem_ctrl(serial, control_state);
719 }
720 
721 static int mct_u232_ioctl (struct usb_serial_port *port, struct file * file,
722 			   unsigned int cmd, unsigned long arg)
723 {
724 	dbg("%scmd=0x%x", __FUNCTION__, cmd);
725 
726 	/* Based on code from acm.c and others */
727 	switch (cmd) {
728 	case TIOCMIWAIT:
729 		/* wait for any of the 4 modem inputs (DCD,RI,DSR,CTS)*/
730 		/* TODO */
731 		return( 0 );
732 
733 	case TIOCGICOUNT:
734 		/* return count of modemline transitions */
735 		/* TODO */
736 		return 0;
737 
738 	default:
739 		dbg("%s: arg not supported - 0x%04x", __FUNCTION__,cmd);
740 		return(-ENOIOCTLCMD);
741 		break;
742 	}
743 	return 0;
744 } /* mct_u232_ioctl */
745 
746 
747 static int __init mct_u232_init (void)
748 {
749 	int retval;
750 	retval = usb_serial_register(&mct_u232_device);
751 	if (retval)
752 		goto failed_usb_serial_register;
753 	retval = usb_register(&mct_u232_driver);
754 	if (retval)
755 		goto failed_usb_register;
756 	info(DRIVER_DESC " " DRIVER_VERSION);
757 	return 0;
758 failed_usb_register:
759 	usb_serial_deregister(&mct_u232_device);
760 failed_usb_serial_register:
761 	return retval;
762 }
763 
764 
765 static void __exit mct_u232_exit (void)
766 {
767 	usb_deregister (&mct_u232_driver);
768 	usb_serial_deregister (&mct_u232_device);
769 }
770 
771 
772 module_init (mct_u232_init);
773 module_exit(mct_u232_exit);
774 
775 MODULE_AUTHOR( DRIVER_AUTHOR );
776 MODULE_DESCRIPTION( DRIVER_DESC );
777 MODULE_LICENSE("GPL");
778 
779 module_param(debug, bool, S_IRUGO | S_IWUSR);
780 MODULE_PARM_DESC(debug, "Debug enabled or not");
781