xref: /linux/drivers/usb/serial/kl5kusb105.c (revision 60b33c133ca0b7c0b6072c87234b63fee6e80558)
1 /*
2  * KLSI KL5KUSB105 chip RS232 converter driver
3  *
4  *   Copyright (C) 2010 Johan Hovold <jhovold@gmail.com>
5  *   Copyright (C) 2001 Utz-Uwe Haus <haus@uuhaus.de>
6  *
7  *   This program is free software; you can redistribute it and/or modify
8  *   it under the terms of the GNU General Public License as published by
9  *   the Free Software Foundation; either version 2 of the License, or
10  *   (at your option) any later version.
11  *
12  * All information about the device was acquired using SniffUSB ans snoopUSB
13  * on Windows98.
14  * It was written out of frustration with the PalmConnect USB Serial adapter
15  * sold by Palm Inc.
16  * Neither Palm, nor their contractor (MCCI) or their supplier (KLSI) provided
17  * information that was not already available.
18  *
19  * It seems that KLSI bought some silicon-design information from ScanLogic,
20  * whose SL11R processor is at the core of the KL5KUSB chipset from KLSI.
21  * KLSI has firmware available for their devices; it is probable that the
22  * firmware differs from that used by KLSI in their products. If you have an
23  * original KLSI device and can provide some information on it, I would be
24  * most interested in adding support for it here. If you have any information
25  * on the protocol used (or find errors in my reverse-engineered stuff), please
26  * let me know.
27  *
28  * The code was only tested with a PalmConnect USB adapter; if you
29  * are adventurous, try it with any KLSI-based device and let me know how it
30  * breaks so that I can fix it!
31  */
32 
33 /* TODO:
34  *	check modem line signals
35  *	implement handshaking or decide that we do not support it
36  */
37 
38 #include <linux/kernel.h>
39 #include <linux/errno.h>
40 #include <linux/init.h>
41 #include <linux/slab.h>
42 #include <linux/tty.h>
43 #include <linux/tty_driver.h>
44 #include <linux/tty_flip.h>
45 #include <linux/module.h>
46 #include <linux/uaccess.h>
47 #include <asm/unaligned.h>
48 #include <linux/usb.h>
49 #include <linux/usb/serial.h>
50 #include "kl5kusb105.h"
51 
52 static int debug;
53 
54 /*
55  * Version Information
56  */
57 #define DRIVER_VERSION "v0.4"
58 #define DRIVER_AUTHOR "Utz-Uwe Haus <haus@uuhaus.de>, Johan Hovold <jhovold@gmail.com>"
59 #define DRIVER_DESC "KLSI KL5KUSB105 chipset USB->Serial Converter driver"
60 
61 
62 /*
63  * Function prototypes
64  */
65 static int  klsi_105_startup(struct usb_serial *serial);
66 static void klsi_105_release(struct usb_serial *serial);
67 static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port);
68 static void klsi_105_close(struct usb_serial_port *port);
69 static void klsi_105_set_termios(struct tty_struct *tty,
70 			struct usb_serial_port *port, struct ktermios *old);
71 static int  klsi_105_tiocmget(struct tty_struct *tty);
72 static int  klsi_105_tiocmset(struct tty_struct *tty, struct file *file,
73 			unsigned int set, unsigned int clear);
74 static void klsi_105_process_read_urb(struct urb *urb);
75 static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
76 						void *dest, size_t size);
77 
78 /*
79  * All of the device info needed for the KLSI converters.
80  */
81 static const struct usb_device_id id_table[] = {
82 	{ USB_DEVICE(PALMCONNECT_VID, PALMCONNECT_PID) },
83 	{ USB_DEVICE(KLSI_VID, KLSI_KL5KUSB105D_PID) },
84 	{ }		/* Terminating entry */
85 };
86 
87 MODULE_DEVICE_TABLE(usb, id_table);
88 
89 static struct usb_driver kl5kusb105d_driver = {
90 	.name =		"kl5kusb105d",
91 	.probe =	usb_serial_probe,
92 	.disconnect =	usb_serial_disconnect,
93 	.id_table =	id_table,
94 	.no_dynamic_id =	1,
95 };
96 
97 static struct usb_serial_driver kl5kusb105d_device = {
98 	.driver = {
99 		.owner =	THIS_MODULE,
100 		.name =		"kl5kusb105d",
101 	},
102 	.description =		"KL5KUSB105D / PalmConnect",
103 	.usb_driver =		&kl5kusb105d_driver,
104 	.id_table =		id_table,
105 	.num_ports =		1,
106 	.bulk_out_size =	64,
107 	.open =			klsi_105_open,
108 	.close =		klsi_105_close,
109 	.set_termios =		klsi_105_set_termios,
110 	/*.break_ctl =		klsi_105_break_ctl,*/
111 	.tiocmget =		klsi_105_tiocmget,
112 	.tiocmset =		klsi_105_tiocmset,
113 	.attach =		klsi_105_startup,
114 	.release =		klsi_105_release,
115 	.throttle =		usb_serial_generic_throttle,
116 	.unthrottle =		usb_serial_generic_unthrottle,
117 	.process_read_urb =	klsi_105_process_read_urb,
118 	.prepare_write_buffer =	klsi_105_prepare_write_buffer,
119 };
120 
121 struct klsi_105_port_settings {
122 	__u8	pktlen;		/* always 5, it seems */
123 	__u8	baudrate;
124 	__u8	databits;
125 	__u8	unknown1;
126 	__u8	unknown2;
127 } __attribute__ ((packed));
128 
129 struct klsi_105_private {
130 	struct klsi_105_port_settings	cfg;
131 	struct ktermios			termios;
132 	unsigned long			line_state; /* modem line settings */
133 	spinlock_t			lock;
134 };
135 
136 
137 /*
138  * Handle vendor specific USB requests
139  */
140 
141 
142 #define KLSI_TIMEOUT	 5000 /* default urb timeout */
143 
144 static int klsi_105_chg_port_settings(struct usb_serial_port *port,
145 				      struct klsi_105_port_settings *settings)
146 {
147 	int rc;
148 
149 	rc = usb_control_msg(port->serial->dev,
150 			usb_sndctrlpipe(port->serial->dev, 0),
151 			KL5KUSB105A_SIO_SET_DATA,
152 			USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_INTERFACE,
153 			0, /* value */
154 			0, /* index */
155 			settings,
156 			sizeof(struct klsi_105_port_settings),
157 			KLSI_TIMEOUT);
158 	if (rc < 0)
159 		dev_err(&port->dev,
160 			"Change port settings failed (error = %d)\n", rc);
161 	dev_info(&port->serial->dev->dev,
162 		 "%d byte block, baudrate %x, databits %d, u1 %d, u2 %d\n",
163 		 settings->pktlen, settings->baudrate, settings->databits,
164 		 settings->unknown1, settings->unknown2);
165 	return rc;
166 }
167 
168 /* translate a 16-bit status value from the device to linux's TIO bits */
169 static unsigned long klsi_105_status2linestate(const __u16 status)
170 {
171 	unsigned long res = 0;
172 
173 	res =   ((status & KL5KUSB105A_DSR) ? TIOCM_DSR : 0)
174 	      | ((status & KL5KUSB105A_CTS) ? TIOCM_CTS : 0)
175 	      ;
176 
177 	return res;
178 }
179 
180 /*
181  * Read line control via vendor command and return result through
182  * *line_state_p
183  */
184 /* It seems that the status buffer has always only 2 bytes length */
185 #define KLSI_STATUSBUF_LEN	2
186 static int klsi_105_get_line_state(struct usb_serial_port *port,
187 				   unsigned long *line_state_p)
188 {
189 	int rc;
190 	u8 *status_buf;
191 	__u16 status;
192 
193 	dev_info(&port->serial->dev->dev, "sending SIO Poll request\n");
194 
195 	status_buf = kmalloc(KLSI_STATUSBUF_LEN, GFP_KERNEL);
196 	if (!status_buf) {
197 		dev_err(&port->dev, "%s - out of memory for status buffer.\n",
198 				__func__);
199 		return -ENOMEM;
200 	}
201 	status_buf[0] = 0xff;
202 	status_buf[1] = 0xff;
203 	rc = usb_control_msg(port->serial->dev,
204 			     usb_rcvctrlpipe(port->serial->dev, 0),
205 			     KL5KUSB105A_SIO_POLL,
206 			     USB_TYPE_VENDOR | USB_DIR_IN,
207 			     0, /* value */
208 			     0, /* index */
209 			     status_buf, KLSI_STATUSBUF_LEN,
210 			     10000
211 			     );
212 	if (rc < 0)
213 		dev_err(&port->dev, "Reading line status failed (error = %d)\n",
214 			rc);
215 	else {
216 		status = get_unaligned_le16(status_buf);
217 
218 		dev_info(&port->serial->dev->dev, "read status %x %x",
219 			 status_buf[0], status_buf[1]);
220 
221 		*line_state_p = klsi_105_status2linestate(status);
222 	}
223 
224 	kfree(status_buf);
225 	return rc;
226 }
227 
228 
229 /*
230  * Driver's tty interface functions
231  */
232 
233 static int klsi_105_startup(struct usb_serial *serial)
234 {
235 	struct klsi_105_private *priv;
236 	int i;
237 
238 	/* check if we support the product id (see keyspan.c)
239 	 * FIXME
240 	 */
241 
242 	/* allocate the private data structure */
243 	for (i = 0; i < serial->num_ports; i++) {
244 		priv = kmalloc(sizeof(struct klsi_105_private),
245 						   GFP_KERNEL);
246 		if (!priv) {
247 			dbg("%skmalloc for klsi_105_private failed.", __func__);
248 			i--;
249 			goto err_cleanup;
250 		}
251 		/* set initial values for control structures */
252 		priv->cfg.pktlen    = 5;
253 		priv->cfg.baudrate  = kl5kusb105a_sio_b9600;
254 		priv->cfg.databits  = kl5kusb105a_dtb_8;
255 		priv->cfg.unknown1  = 0;
256 		priv->cfg.unknown2  = 1;
257 
258 		priv->line_state    = 0;
259 
260 		usb_set_serial_port_data(serial->port[i], priv);
261 
262 		spin_lock_init(&priv->lock);
263 
264 		/* priv->termios is left uninitialized until port opening */
265 		init_waitqueue_head(&serial->port[i]->write_wait);
266 	}
267 
268 	return 0;
269 
270 err_cleanup:
271 	for (; i >= 0; i--) {
272 		priv = usb_get_serial_port_data(serial->port[i]);
273 		kfree(priv);
274 		usb_set_serial_port_data(serial->port[i], NULL);
275 	}
276 	return -ENOMEM;
277 }
278 
279 static void klsi_105_release(struct usb_serial *serial)
280 {
281 	int i;
282 
283 	dbg("%s", __func__);
284 
285 	for (i = 0; i < serial->num_ports; ++i)
286 		kfree(usb_get_serial_port_data(serial->port[i]));
287 }
288 
289 static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port)
290 {
291 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
292 	int retval = 0;
293 	int rc;
294 	int i;
295 	unsigned long line_state;
296 	struct klsi_105_port_settings *cfg;
297 	unsigned long flags;
298 
299 	dbg("%s port %d", __func__, port->number);
300 
301 	/* Do a defined restart:
302 	 * Set up sane default baud rate and send the 'READ_ON'
303 	 * vendor command.
304 	 * FIXME: set modem line control (how?)
305 	 * Then read the modem line control and store values in
306 	 * priv->line_state.
307 	 */
308 	cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
309 	if (!cfg) {
310 		dev_err(&port->dev, "%s - out of memory for config buffer.\n",
311 				__func__);
312 		return -ENOMEM;
313 	}
314 	cfg->pktlen   = 5;
315 	cfg->baudrate = kl5kusb105a_sio_b9600;
316 	cfg->databits = kl5kusb105a_dtb_8;
317 	cfg->unknown1 = 0;
318 	cfg->unknown2 = 1;
319 	klsi_105_chg_port_settings(port, cfg);
320 
321 	/* set up termios structure */
322 	spin_lock_irqsave(&priv->lock, flags);
323 	priv->termios.c_iflag = tty->termios->c_iflag;
324 	priv->termios.c_oflag = tty->termios->c_oflag;
325 	priv->termios.c_cflag = tty->termios->c_cflag;
326 	priv->termios.c_lflag = tty->termios->c_lflag;
327 	for (i = 0; i < NCCS; i++)
328 		priv->termios.c_cc[i] = tty->termios->c_cc[i];
329 	priv->cfg.pktlen   = cfg->pktlen;
330 	priv->cfg.baudrate = cfg->baudrate;
331 	priv->cfg.databits = cfg->databits;
332 	priv->cfg.unknown1 = cfg->unknown1;
333 	priv->cfg.unknown2 = cfg->unknown2;
334 	spin_unlock_irqrestore(&priv->lock, flags);
335 
336 	/* READ_ON and urb submission */
337 	rc = usb_serial_generic_open(tty, port);
338 	if (rc) {
339 		retval = rc;
340 		goto exit;
341 	}
342 
343 	rc = usb_control_msg(port->serial->dev,
344 			     usb_sndctrlpipe(port->serial->dev, 0),
345 			     KL5KUSB105A_SIO_CONFIGURE,
346 			     USB_TYPE_VENDOR|USB_DIR_OUT|USB_RECIP_INTERFACE,
347 			     KL5KUSB105A_SIO_CONFIGURE_READ_ON,
348 			     0, /* index */
349 			     NULL,
350 			     0,
351 			     KLSI_TIMEOUT);
352 	if (rc < 0) {
353 		dev_err(&port->dev, "Enabling read failed (error = %d)\n", rc);
354 		retval = rc;
355 	} else
356 		dbg("%s - enabled reading", __func__);
357 
358 	rc = klsi_105_get_line_state(port, &line_state);
359 	if (rc >= 0) {
360 		spin_lock_irqsave(&priv->lock, flags);
361 		priv->line_state = line_state;
362 		spin_unlock_irqrestore(&priv->lock, flags);
363 		dbg("%s - read line state 0x%lx", __func__, line_state);
364 		retval = 0;
365 	} else
366 		retval = rc;
367 
368 exit:
369 	kfree(cfg);
370 	return retval;
371 }
372 
373 static void klsi_105_close(struct usb_serial_port *port)
374 {
375 	int rc;
376 
377 	dbg("%s port %d", __func__, port->number);
378 
379 	mutex_lock(&port->serial->disc_mutex);
380 	if (!port->serial->disconnected) {
381 		/* send READ_OFF */
382 		rc = usb_control_msg(port->serial->dev,
383 				     usb_sndctrlpipe(port->serial->dev, 0),
384 				     KL5KUSB105A_SIO_CONFIGURE,
385 				     USB_TYPE_VENDOR | USB_DIR_OUT,
386 				     KL5KUSB105A_SIO_CONFIGURE_READ_OFF,
387 				     0, /* index */
388 				     NULL, 0,
389 				     KLSI_TIMEOUT);
390 		if (rc < 0)
391 			dev_err(&port->dev,
392 				"Disabling read failed (error = %d)\n", rc);
393 	}
394 	mutex_unlock(&port->serial->disc_mutex);
395 
396 	/* shutdown our bulk reads and writes */
397 	usb_serial_generic_close(port);
398 
399 	/* wgg - do I need this? I think so. */
400 	usb_kill_urb(port->interrupt_in_urb);
401 }
402 
403 /* We need to write a complete 64-byte data block and encode the
404  * number actually sent in the first double-byte, LSB-order. That
405  * leaves at most 62 bytes of payload.
406  */
407 #define KLSI_HDR_LEN		2
408 static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
409 						void *dest, size_t size)
410 {
411 	unsigned char *buf = dest;
412 	int count;
413 
414 	count = kfifo_out_locked(&port->write_fifo, buf + KLSI_HDR_LEN, size,
415 								&port->lock);
416 	put_unaligned_le16(count, buf);
417 
418 	return count + KLSI_HDR_LEN;
419 }
420 
421 /* The data received is preceded by a length double-byte in LSB-first order.
422  */
423 static void klsi_105_process_read_urb(struct urb *urb)
424 {
425 	struct usb_serial_port *port = urb->context;
426 	unsigned char *data = urb->transfer_buffer;
427 	struct tty_struct *tty;
428 	unsigned len;
429 
430 	/* empty urbs seem to happen, we ignore them */
431 	if (!urb->actual_length)
432 		return;
433 
434 	if (urb->actual_length <= KLSI_HDR_LEN) {
435 		dbg("%s - malformed packet", __func__);
436 		return;
437 	}
438 
439 	tty = tty_port_tty_get(&port->port);
440 	if (!tty)
441 		return;
442 
443 	len = get_unaligned_le16(data);
444 	if (len > urb->actual_length - KLSI_HDR_LEN) {
445 		dbg("%s - packet length mismatch", __func__);
446 		len = urb->actual_length - KLSI_HDR_LEN;
447 	}
448 
449 	tty_insert_flip_string(tty, data + KLSI_HDR_LEN, len);
450 	tty_flip_buffer_push(tty);
451 	tty_kref_put(tty);
452 }
453 
454 static void klsi_105_set_termios(struct tty_struct *tty,
455 				 struct usb_serial_port *port,
456 				 struct ktermios *old_termios)
457 {
458 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
459 	unsigned int iflag = tty->termios->c_iflag;
460 	unsigned int old_iflag = old_termios->c_iflag;
461 	unsigned int cflag = tty->termios->c_cflag;
462 	unsigned int old_cflag = old_termios->c_cflag;
463 	struct klsi_105_port_settings *cfg;
464 	unsigned long flags;
465 	speed_t baud;
466 
467 	cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
468 	if (!cfg) {
469 		dev_err(&port->dev, "%s - out of memory for config buffer.\n",
470 				__func__);
471 		return;
472 	}
473 
474 	/* lock while we are modifying the settings */
475 	spin_lock_irqsave(&priv->lock, flags);
476 
477 	/*
478 	 * Update baud rate
479 	 */
480 	baud = tty_get_baud_rate(tty);
481 
482 	if ((cflag & CBAUD) != (old_cflag & CBAUD)) {
483 		/* reassert DTR and (maybe) RTS on transition from B0 */
484 		if ((old_cflag & CBAUD) == B0) {
485 			dbg("%s: baud was B0", __func__);
486 #if 0
487 			priv->control_state |= TIOCM_DTR;
488 			/* don't set RTS if using hardware flow control */
489 			if (!(old_cflag & CRTSCTS))
490 				priv->control_state |= TIOCM_RTS;
491 			mct_u232_set_modem_ctrl(serial, priv->control_state);
492 #endif
493 		}
494 	}
495 	switch (baud) {
496 	case 0: /* handled below */
497 		break;
498 	case 1200:
499 		priv->cfg.baudrate = kl5kusb105a_sio_b1200;
500 		break;
501 	case 2400:
502 		priv->cfg.baudrate = kl5kusb105a_sio_b2400;
503 		break;
504 	case 4800:
505 		priv->cfg.baudrate = kl5kusb105a_sio_b4800;
506 		break;
507 	case 9600:
508 		priv->cfg.baudrate = kl5kusb105a_sio_b9600;
509 		break;
510 	case 19200:
511 		priv->cfg.baudrate = kl5kusb105a_sio_b19200;
512 		break;
513 	case 38400:
514 		priv->cfg.baudrate = kl5kusb105a_sio_b38400;
515 		break;
516 	case 57600:
517 		priv->cfg.baudrate = kl5kusb105a_sio_b57600;
518 		break;
519 	case 115200:
520 		priv->cfg.baudrate = kl5kusb105a_sio_b115200;
521 		break;
522 	default:
523 		dbg("KLSI USB->Serial converter:"
524 		    " unsupported baudrate request, using default of 9600");
525 			priv->cfg.baudrate = kl5kusb105a_sio_b9600;
526 		baud = 9600;
527 		break;
528 	}
529 	if ((cflag & CBAUD) == B0) {
530 		dbg("%s: baud is B0", __func__);
531 		/* Drop RTS and DTR */
532 		/* maybe this should be simulated by sending read
533 		 * disable and read enable messages?
534 		 */
535 		;
536 #if 0
537 		priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
538 		mct_u232_set_modem_ctrl(serial, priv->control_state);
539 #endif
540 	}
541 	tty_encode_baud_rate(tty, baud, baud);
542 
543 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
544 		/* set the number of data bits */
545 		switch (cflag & CSIZE) {
546 		case CS5:
547 			dbg("%s - 5 bits/byte not supported", __func__);
548 			spin_unlock_irqrestore(&priv->lock, flags);
549 			goto err;
550 		case CS6:
551 			dbg("%s - 6 bits/byte not supported", __func__);
552 			spin_unlock_irqrestore(&priv->lock, flags);
553 			goto err;
554 		case CS7:
555 			priv->cfg.databits = kl5kusb105a_dtb_7;
556 			break;
557 		case CS8:
558 			priv->cfg.databits = kl5kusb105a_dtb_8;
559 			break;
560 		default:
561 			dev_err(&port->dev,
562 				"CSIZE was not CS5-CS8, using default of 8\n");
563 			priv->cfg.databits = kl5kusb105a_dtb_8;
564 			break;
565 		}
566 	}
567 
568 	/*
569 	 * Update line control register (LCR)
570 	 */
571 	if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))
572 	    || (cflag & CSTOPB) != (old_cflag & CSTOPB)) {
573 		/* Not currently supported */
574 		tty->termios->c_cflag &= ~(PARENB|PARODD|CSTOPB);
575 #if 0
576 		priv->last_lcr = 0;
577 
578 		/* set the parity */
579 		if (cflag & PARENB)
580 			priv->last_lcr |= (cflag & PARODD) ?
581 				MCT_U232_PARITY_ODD : MCT_U232_PARITY_EVEN;
582 		else
583 			priv->last_lcr |= MCT_U232_PARITY_NONE;
584 
585 		/* set the number of stop bits */
586 		priv->last_lcr |= (cflag & CSTOPB) ?
587 			MCT_U232_STOP_BITS_2 : MCT_U232_STOP_BITS_1;
588 
589 		mct_u232_set_line_ctrl(serial, priv->last_lcr);
590 #endif
591 		;
592 	}
593 	/*
594 	 * Set flow control: well, I do not really now how to handle DTR/RTS.
595 	 * Just do what we have seen with SniffUSB on Win98.
596 	 */
597 	if ((iflag & IXOFF) != (old_iflag & IXOFF)
598 	    || (iflag & IXON) != (old_iflag & IXON)
599 	    ||  (cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
600 		/* Not currently supported */
601 		tty->termios->c_cflag &= ~CRTSCTS;
602 		/* Drop DTR/RTS if no flow control otherwise assert */
603 #if 0
604 		if ((iflag & IXOFF) || (iflag & IXON) || (cflag & CRTSCTS))
605 			priv->control_state |= TIOCM_DTR | TIOCM_RTS;
606 		else
607 			priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
608 		mct_u232_set_modem_ctrl(serial, priv->control_state);
609 #endif
610 		;
611 	}
612 	memcpy(cfg, &priv->cfg, sizeof(*cfg));
613 	spin_unlock_irqrestore(&priv->lock, flags);
614 
615 	/* now commit changes to device */
616 	klsi_105_chg_port_settings(port, cfg);
617 err:
618 	kfree(cfg);
619 }
620 
621 #if 0
622 static void mct_u232_break_ctl(struct tty_struct *tty, int break_state)
623 {
624 	struct usb_serial_port *port = tty->driver_data;
625 	struct usb_serial *serial = port->serial;
626 	struct mct_u232_private *priv =
627 				(struct mct_u232_private *)port->private;
628 	unsigned char lcr = priv->last_lcr;
629 
630 	dbg("%sstate=%d", __func__, break_state);
631 
632 	/* LOCKING */
633 	if (break_state)
634 		lcr |= MCT_U232_SET_BREAK;
635 
636 	mct_u232_set_line_ctrl(serial, lcr);
637 }
638 #endif
639 
640 static int klsi_105_tiocmget(struct tty_struct *tty)
641 {
642 	struct usb_serial_port *port = tty->driver_data;
643 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
644 	unsigned long flags;
645 	int rc;
646 	unsigned long line_state;
647 	dbg("%s - request, just guessing", __func__);
648 
649 	rc = klsi_105_get_line_state(port, &line_state);
650 	if (rc < 0) {
651 		dev_err(&port->dev,
652 			"Reading line control failed (error = %d)\n", rc);
653 		/* better return value? EAGAIN? */
654 		return rc;
655 	}
656 
657 	spin_lock_irqsave(&priv->lock, flags);
658 	priv->line_state = line_state;
659 	spin_unlock_irqrestore(&priv->lock, flags);
660 	dbg("%s - read line state 0x%lx", __func__, line_state);
661 	return (int)line_state;
662 }
663 
664 static int klsi_105_tiocmset(struct tty_struct *tty, struct file *file,
665 			     unsigned int set, unsigned int clear)
666 {
667 	int retval = -EINVAL;
668 
669 	dbg("%s", __func__);
670 
671 /* if this ever gets implemented, it should be done something like this:
672 	struct usb_serial *serial = port->serial;
673 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
674 	unsigned long flags;
675 	int control;
676 
677 	spin_lock_irqsave (&priv->lock, flags);
678 	if (set & TIOCM_RTS)
679 		priv->control_state |= TIOCM_RTS;
680 	if (set & TIOCM_DTR)
681 		priv->control_state |= TIOCM_DTR;
682 	if (clear & TIOCM_RTS)
683 		priv->control_state &= ~TIOCM_RTS;
684 	if (clear & TIOCM_DTR)
685 		priv->control_state &= ~TIOCM_DTR;
686 	control = priv->control_state;
687 	spin_unlock_irqrestore (&priv->lock, flags);
688 	retval = mct_u232_set_modem_ctrl(serial, control);
689 */
690 	return retval;
691 }
692 
693 
694 static int __init klsi_105_init(void)
695 {
696 	int retval;
697 	retval = usb_serial_register(&kl5kusb105d_device);
698 	if (retval)
699 		goto failed_usb_serial_register;
700 	retval = usb_register(&kl5kusb105d_driver);
701 	if (retval)
702 		goto failed_usb_register;
703 
704 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
705 	       DRIVER_DESC "\n");
706 	return 0;
707 failed_usb_register:
708 	usb_serial_deregister(&kl5kusb105d_device);
709 failed_usb_serial_register:
710 	return retval;
711 }
712 
713 static void __exit klsi_105_exit(void)
714 {
715 	usb_deregister(&kl5kusb105d_driver);
716 	usb_serial_deregister(&kl5kusb105d_device);
717 }
718 
719 
720 module_init(klsi_105_init);
721 module_exit(klsi_105_exit);
722 
723 MODULE_AUTHOR(DRIVER_AUTHOR);
724 MODULE_DESCRIPTION(DRIVER_DESC);
725 MODULE_LICENSE("GPL");
726 
727 
728 module_param(debug, bool, S_IRUGO | S_IWUSR);
729 MODULE_PARM_DESC(debug, "enable extensive debugging messages");
730