xref: /linux/drivers/usb/serial/kl5kusb105.c (revision f49f4ab95c301dbccad0efe85296d908b8ae7ad4)
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 /*
53  * Version Information
54  */
55 #define DRIVER_VERSION "v0.4"
56 #define DRIVER_AUTHOR "Utz-Uwe Haus <haus@uuhaus.de>, Johan Hovold <jhovold@gmail.com>"
57 #define DRIVER_DESC "KLSI KL5KUSB105 chipset USB->Serial Converter driver"
58 
59 
60 /*
61  * Function prototypes
62  */
63 static int klsi_105_port_probe(struct usb_serial_port *port);
64 static int klsi_105_port_remove(struct usb_serial_port *port);
65 static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port);
66 static void klsi_105_close(struct usb_serial_port *port);
67 static void klsi_105_set_termios(struct tty_struct *tty,
68 			struct usb_serial_port *port, struct ktermios *old);
69 static int  klsi_105_tiocmget(struct tty_struct *tty);
70 static int  klsi_105_tiocmset(struct tty_struct *tty,
71 			unsigned int set, unsigned int clear);
72 static void klsi_105_process_read_urb(struct urb *urb);
73 static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
74 						void *dest, size_t size);
75 
76 /*
77  * All of the device info needed for the KLSI converters.
78  */
79 static const struct usb_device_id id_table[] = {
80 	{ USB_DEVICE(PALMCONNECT_VID, PALMCONNECT_PID) },
81 	{ USB_DEVICE(KLSI_VID, KLSI_KL5KUSB105D_PID) },
82 	{ }		/* Terminating entry */
83 };
84 
85 MODULE_DEVICE_TABLE(usb, id_table);
86 
87 static struct usb_serial_driver kl5kusb105d_device = {
88 	.driver = {
89 		.owner =	THIS_MODULE,
90 		.name =		"kl5kusb105d",
91 	},
92 	.description =		"KL5KUSB105D / PalmConnect",
93 	.id_table =		id_table,
94 	.num_ports =		1,
95 	.bulk_out_size =	64,
96 	.open =			klsi_105_open,
97 	.close =		klsi_105_close,
98 	.set_termios =		klsi_105_set_termios,
99 	/*.break_ctl =		klsi_105_break_ctl,*/
100 	.tiocmget =		klsi_105_tiocmget,
101 	.tiocmset =		klsi_105_tiocmset,
102 	.port_probe =		klsi_105_port_probe,
103 	.port_remove =		klsi_105_port_remove,
104 	.throttle =		usb_serial_generic_throttle,
105 	.unthrottle =		usb_serial_generic_unthrottle,
106 	.process_read_urb =	klsi_105_process_read_urb,
107 	.prepare_write_buffer =	klsi_105_prepare_write_buffer,
108 };
109 
110 static struct usb_serial_driver * const serial_drivers[] = {
111 	&kl5kusb105d_device, NULL
112 };
113 
114 struct klsi_105_port_settings {
115 	__u8	pktlen;		/* always 5, it seems */
116 	__u8	baudrate;
117 	__u8	databits;
118 	__u8	unknown1;
119 	__u8	unknown2;
120 } __attribute__ ((packed));
121 
122 struct klsi_105_private {
123 	struct klsi_105_port_settings	cfg;
124 	struct ktermios			termios;
125 	unsigned long			line_state; /* modem line settings */
126 	spinlock_t			lock;
127 };
128 
129 
130 /*
131  * Handle vendor specific USB requests
132  */
133 
134 
135 #define KLSI_TIMEOUT	 5000 /* default urb timeout */
136 
137 static int klsi_105_chg_port_settings(struct usb_serial_port *port,
138 				      struct klsi_105_port_settings *settings)
139 {
140 	int rc;
141 
142 	rc = usb_control_msg(port->serial->dev,
143 			usb_sndctrlpipe(port->serial->dev, 0),
144 			KL5KUSB105A_SIO_SET_DATA,
145 			USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_INTERFACE,
146 			0, /* value */
147 			0, /* index */
148 			settings,
149 			sizeof(struct klsi_105_port_settings),
150 			KLSI_TIMEOUT);
151 	if (rc < 0)
152 		dev_err(&port->dev,
153 			"Change port settings failed (error = %d)\n", rc);
154 	dev_info(&port->serial->dev->dev,
155 		 "%d byte block, baudrate %x, databits %d, u1 %d, u2 %d\n",
156 		 settings->pktlen, settings->baudrate, settings->databits,
157 		 settings->unknown1, settings->unknown2);
158 	return rc;
159 }
160 
161 /* translate a 16-bit status value from the device to linux's TIO bits */
162 static unsigned long klsi_105_status2linestate(const __u16 status)
163 {
164 	unsigned long res = 0;
165 
166 	res =   ((status & KL5KUSB105A_DSR) ? TIOCM_DSR : 0)
167 	      | ((status & KL5KUSB105A_CTS) ? TIOCM_CTS : 0)
168 	      ;
169 
170 	return res;
171 }
172 
173 /*
174  * Read line control via vendor command and return result through
175  * *line_state_p
176  */
177 /* It seems that the status buffer has always only 2 bytes length */
178 #define KLSI_STATUSBUF_LEN	2
179 static int klsi_105_get_line_state(struct usb_serial_port *port,
180 				   unsigned long *line_state_p)
181 {
182 	int rc;
183 	u8 *status_buf;
184 	__u16 status;
185 
186 	dev_info(&port->serial->dev->dev, "sending SIO Poll request\n");
187 
188 	status_buf = kmalloc(KLSI_STATUSBUF_LEN, GFP_KERNEL);
189 	if (!status_buf) {
190 		dev_err(&port->dev, "%s - out of memory for status buffer.\n",
191 				__func__);
192 		return -ENOMEM;
193 	}
194 	status_buf[0] = 0xff;
195 	status_buf[1] = 0xff;
196 	rc = usb_control_msg(port->serial->dev,
197 			     usb_rcvctrlpipe(port->serial->dev, 0),
198 			     KL5KUSB105A_SIO_POLL,
199 			     USB_TYPE_VENDOR | USB_DIR_IN,
200 			     0, /* value */
201 			     0, /* index */
202 			     status_buf, KLSI_STATUSBUF_LEN,
203 			     10000
204 			     );
205 	if (rc < 0)
206 		dev_err(&port->dev, "Reading line status failed (error = %d)\n",
207 			rc);
208 	else {
209 		status = get_unaligned_le16(status_buf);
210 
211 		dev_info(&port->serial->dev->dev, "read status %x %x",
212 			 status_buf[0], status_buf[1]);
213 
214 		*line_state_p = klsi_105_status2linestate(status);
215 	}
216 
217 	kfree(status_buf);
218 	return rc;
219 }
220 
221 
222 /*
223  * Driver's tty interface functions
224  */
225 
226 static int klsi_105_port_probe(struct usb_serial_port *port)
227 {
228 	struct klsi_105_private *priv;
229 
230 	priv = kmalloc(sizeof(*priv), GFP_KERNEL);
231 	if (!priv)
232 		return -ENOMEM;
233 
234 	/* set initial values for control structures */
235 	priv->cfg.pktlen    = 5;
236 	priv->cfg.baudrate  = kl5kusb105a_sio_b9600;
237 	priv->cfg.databits  = kl5kusb105a_dtb_8;
238 	priv->cfg.unknown1  = 0;
239 	priv->cfg.unknown2  = 1;
240 
241 	priv->line_state    = 0;
242 
243 	spin_lock_init(&priv->lock);
244 
245 	/* priv->termios is left uninitialized until port opening */
246 
247 	usb_set_serial_port_data(port, priv);
248 
249 	return 0;
250 }
251 
252 static int klsi_105_port_remove(struct usb_serial_port *port)
253 {
254 	struct klsi_105_private *priv;
255 
256 	priv = usb_get_serial_port_data(port);
257 	kfree(priv);
258 
259 	return 0;
260 }
261 
262 static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port)
263 {
264 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
265 	int retval = 0;
266 	int rc;
267 	int i;
268 	unsigned long line_state;
269 	struct klsi_105_port_settings *cfg;
270 	unsigned long flags;
271 
272 	/* Do a defined restart:
273 	 * Set up sane default baud rate and send the 'READ_ON'
274 	 * vendor command.
275 	 * FIXME: set modem line control (how?)
276 	 * Then read the modem line control and store values in
277 	 * priv->line_state.
278 	 */
279 	cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
280 	if (!cfg) {
281 		dev_err(&port->dev, "%s - out of memory for config buffer.\n",
282 				__func__);
283 		return -ENOMEM;
284 	}
285 	cfg->pktlen   = 5;
286 	cfg->baudrate = kl5kusb105a_sio_b9600;
287 	cfg->databits = kl5kusb105a_dtb_8;
288 	cfg->unknown1 = 0;
289 	cfg->unknown2 = 1;
290 	klsi_105_chg_port_settings(port, cfg);
291 
292 	/* set up termios structure */
293 	spin_lock_irqsave(&priv->lock, flags);
294 	priv->termios.c_iflag = tty->termios.c_iflag;
295 	priv->termios.c_oflag = tty->termios.c_oflag;
296 	priv->termios.c_cflag = tty->termios.c_cflag;
297 	priv->termios.c_lflag = tty->termios.c_lflag;
298 	for (i = 0; i < NCCS; i++)
299 		priv->termios.c_cc[i] = tty->termios.c_cc[i];
300 	priv->cfg.pktlen   = cfg->pktlen;
301 	priv->cfg.baudrate = cfg->baudrate;
302 	priv->cfg.databits = cfg->databits;
303 	priv->cfg.unknown1 = cfg->unknown1;
304 	priv->cfg.unknown2 = cfg->unknown2;
305 	spin_unlock_irqrestore(&priv->lock, flags);
306 
307 	/* READ_ON and urb submission */
308 	rc = usb_serial_generic_open(tty, port);
309 	if (rc) {
310 		retval = rc;
311 		goto exit;
312 	}
313 
314 	rc = usb_control_msg(port->serial->dev,
315 			     usb_sndctrlpipe(port->serial->dev, 0),
316 			     KL5KUSB105A_SIO_CONFIGURE,
317 			     USB_TYPE_VENDOR|USB_DIR_OUT|USB_RECIP_INTERFACE,
318 			     KL5KUSB105A_SIO_CONFIGURE_READ_ON,
319 			     0, /* index */
320 			     NULL,
321 			     0,
322 			     KLSI_TIMEOUT);
323 	if (rc < 0) {
324 		dev_err(&port->dev, "Enabling read failed (error = %d)\n", rc);
325 		retval = rc;
326 	} else
327 		dev_dbg(&port->dev, "%s - enabled reading\n", __func__);
328 
329 	rc = klsi_105_get_line_state(port, &line_state);
330 	if (rc >= 0) {
331 		spin_lock_irqsave(&priv->lock, flags);
332 		priv->line_state = line_state;
333 		spin_unlock_irqrestore(&priv->lock, flags);
334 		dev_dbg(&port->dev, "%s - read line state 0x%lx\n", __func__, line_state);
335 		retval = 0;
336 	} else
337 		retval = rc;
338 
339 exit:
340 	kfree(cfg);
341 	return retval;
342 }
343 
344 static void klsi_105_close(struct usb_serial_port *port)
345 {
346 	int rc;
347 
348 	mutex_lock(&port->serial->disc_mutex);
349 	if (!port->serial->disconnected) {
350 		/* send READ_OFF */
351 		rc = usb_control_msg(port->serial->dev,
352 				     usb_sndctrlpipe(port->serial->dev, 0),
353 				     KL5KUSB105A_SIO_CONFIGURE,
354 				     USB_TYPE_VENDOR | USB_DIR_OUT,
355 				     KL5KUSB105A_SIO_CONFIGURE_READ_OFF,
356 				     0, /* index */
357 				     NULL, 0,
358 				     KLSI_TIMEOUT);
359 		if (rc < 0)
360 			dev_err(&port->dev,
361 				"Disabling read failed (error = %d)\n", rc);
362 	}
363 	mutex_unlock(&port->serial->disc_mutex);
364 
365 	/* shutdown our bulk reads and writes */
366 	usb_serial_generic_close(port);
367 
368 	/* wgg - do I need this? I think so. */
369 	usb_kill_urb(port->interrupt_in_urb);
370 }
371 
372 /* We need to write a complete 64-byte data block and encode the
373  * number actually sent in the first double-byte, LSB-order. That
374  * leaves at most 62 bytes of payload.
375  */
376 #define KLSI_HDR_LEN		2
377 static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
378 						void *dest, size_t size)
379 {
380 	unsigned char *buf = dest;
381 	int count;
382 
383 	count = kfifo_out_locked(&port->write_fifo, buf + KLSI_HDR_LEN, size,
384 								&port->lock);
385 	put_unaligned_le16(count, buf);
386 
387 	return count + KLSI_HDR_LEN;
388 }
389 
390 /* The data received is preceded by a length double-byte in LSB-first order.
391  */
392 static void klsi_105_process_read_urb(struct urb *urb)
393 {
394 	struct usb_serial_port *port = urb->context;
395 	unsigned char *data = urb->transfer_buffer;
396 	struct tty_struct *tty;
397 	unsigned len;
398 
399 	/* empty urbs seem to happen, we ignore them */
400 	if (!urb->actual_length)
401 		return;
402 
403 	if (urb->actual_length <= KLSI_HDR_LEN) {
404 		dev_dbg(&port->dev, "%s - malformed packet\n", __func__);
405 		return;
406 	}
407 
408 	tty = tty_port_tty_get(&port->port);
409 	if (!tty)
410 		return;
411 
412 	len = get_unaligned_le16(data);
413 	if (len > urb->actual_length - KLSI_HDR_LEN) {
414 		dev_dbg(&port->dev, "%s - packet length mismatch\n", __func__);
415 		len = urb->actual_length - KLSI_HDR_LEN;
416 	}
417 
418 	tty_insert_flip_string(tty, data + KLSI_HDR_LEN, len);
419 	tty_flip_buffer_push(tty);
420 	tty_kref_put(tty);
421 }
422 
423 static void klsi_105_set_termios(struct tty_struct *tty,
424 				 struct usb_serial_port *port,
425 				 struct ktermios *old_termios)
426 {
427 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
428 	struct device *dev = &port->dev;
429 	unsigned int iflag = tty->termios.c_iflag;
430 	unsigned int old_iflag = old_termios->c_iflag;
431 	unsigned int cflag = tty->termios.c_cflag;
432 	unsigned int old_cflag = old_termios->c_cflag;
433 	struct klsi_105_port_settings *cfg;
434 	unsigned long flags;
435 	speed_t baud;
436 
437 	cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
438 	if (!cfg) {
439 		dev_err(dev, "%s - out of memory for config buffer.\n", __func__);
440 		return;
441 	}
442 
443 	/* lock while we are modifying the settings */
444 	spin_lock_irqsave(&priv->lock, flags);
445 
446 	/*
447 	 * Update baud rate
448 	 */
449 	baud = tty_get_baud_rate(tty);
450 
451 	if ((cflag & CBAUD) != (old_cflag & CBAUD)) {
452 		/* reassert DTR and (maybe) RTS on transition from B0 */
453 		if ((old_cflag & CBAUD) == B0) {
454 			dev_dbg(dev, "%s: baud was B0\n", __func__);
455 #if 0
456 			priv->control_state |= TIOCM_DTR;
457 			/* don't set RTS if using hardware flow control */
458 			if (!(old_cflag & CRTSCTS))
459 				priv->control_state |= TIOCM_RTS;
460 			mct_u232_set_modem_ctrl(serial, priv->control_state);
461 #endif
462 		}
463 	}
464 	switch (baud) {
465 	case 0: /* handled below */
466 		break;
467 	case 1200:
468 		priv->cfg.baudrate = kl5kusb105a_sio_b1200;
469 		break;
470 	case 2400:
471 		priv->cfg.baudrate = kl5kusb105a_sio_b2400;
472 		break;
473 	case 4800:
474 		priv->cfg.baudrate = kl5kusb105a_sio_b4800;
475 		break;
476 	case 9600:
477 		priv->cfg.baudrate = kl5kusb105a_sio_b9600;
478 		break;
479 	case 19200:
480 		priv->cfg.baudrate = kl5kusb105a_sio_b19200;
481 		break;
482 	case 38400:
483 		priv->cfg.baudrate = kl5kusb105a_sio_b38400;
484 		break;
485 	case 57600:
486 		priv->cfg.baudrate = kl5kusb105a_sio_b57600;
487 		break;
488 	case 115200:
489 		priv->cfg.baudrate = kl5kusb105a_sio_b115200;
490 		break;
491 	default:
492 		dev_dbg(dev, "KLSI USB->Serial converter: unsupported baudrate request, using default of 9600");
493 		priv->cfg.baudrate = kl5kusb105a_sio_b9600;
494 		baud = 9600;
495 		break;
496 	}
497 	if ((cflag & CBAUD) == B0) {
498 		dev_dbg(dev, "%s: baud is B0\n", __func__);
499 		/* Drop RTS and DTR */
500 		/* maybe this should be simulated by sending read
501 		 * disable and read enable messages?
502 		 */
503 		;
504 #if 0
505 		priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
506 		mct_u232_set_modem_ctrl(serial, priv->control_state);
507 #endif
508 	}
509 	tty_encode_baud_rate(tty, baud, baud);
510 
511 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
512 		/* set the number of data bits */
513 		switch (cflag & CSIZE) {
514 		case CS5:
515 			dev_dbg(dev, "%s - 5 bits/byte not supported\n", __func__);
516 			spin_unlock_irqrestore(&priv->lock, flags);
517 			goto err;
518 		case CS6:
519 			dev_dbg(dev, "%s - 6 bits/byte not supported\n", __func__);
520 			spin_unlock_irqrestore(&priv->lock, flags);
521 			goto err;
522 		case CS7:
523 			priv->cfg.databits = kl5kusb105a_dtb_7;
524 			break;
525 		case CS8:
526 			priv->cfg.databits = kl5kusb105a_dtb_8;
527 			break;
528 		default:
529 			dev_err(dev, "CSIZE was not CS5-CS8, using default of 8\n");
530 			priv->cfg.databits = kl5kusb105a_dtb_8;
531 			break;
532 		}
533 	}
534 
535 	/*
536 	 * Update line control register (LCR)
537 	 */
538 	if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))
539 	    || (cflag & CSTOPB) != (old_cflag & CSTOPB)) {
540 		/* Not currently supported */
541 		tty->termios.c_cflag &= ~(PARENB|PARODD|CSTOPB);
542 #if 0
543 		priv->last_lcr = 0;
544 
545 		/* set the parity */
546 		if (cflag & PARENB)
547 			priv->last_lcr |= (cflag & PARODD) ?
548 				MCT_U232_PARITY_ODD : MCT_U232_PARITY_EVEN;
549 		else
550 			priv->last_lcr |= MCT_U232_PARITY_NONE;
551 
552 		/* set the number of stop bits */
553 		priv->last_lcr |= (cflag & CSTOPB) ?
554 			MCT_U232_STOP_BITS_2 : MCT_U232_STOP_BITS_1;
555 
556 		mct_u232_set_line_ctrl(serial, priv->last_lcr);
557 #endif
558 		;
559 	}
560 	/*
561 	 * Set flow control: well, I do not really now how to handle DTR/RTS.
562 	 * Just do what we have seen with SniffUSB on Win98.
563 	 */
564 	if ((iflag & IXOFF) != (old_iflag & IXOFF)
565 	    || (iflag & IXON) != (old_iflag & IXON)
566 	    ||  (cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
567 		/* Not currently supported */
568 		tty->termios.c_cflag &= ~CRTSCTS;
569 		/* Drop DTR/RTS if no flow control otherwise assert */
570 #if 0
571 		if ((iflag & IXOFF) || (iflag & IXON) || (cflag & CRTSCTS))
572 			priv->control_state |= TIOCM_DTR | TIOCM_RTS;
573 		else
574 			priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
575 		mct_u232_set_modem_ctrl(serial, priv->control_state);
576 #endif
577 		;
578 	}
579 	memcpy(cfg, &priv->cfg, sizeof(*cfg));
580 	spin_unlock_irqrestore(&priv->lock, flags);
581 
582 	/* now commit changes to device */
583 	klsi_105_chg_port_settings(port, cfg);
584 err:
585 	kfree(cfg);
586 }
587 
588 #if 0
589 static void mct_u232_break_ctl(struct tty_struct *tty, int break_state)
590 {
591 	struct usb_serial_port *port = tty->driver_data;
592 	struct usb_serial *serial = port->serial;
593 	struct mct_u232_private *priv =
594 				(struct mct_u232_private *)port->private;
595 	unsigned char lcr = priv->last_lcr;
596 
597 	dev_dbg(&port->dev, "%s - state=%d\n", __func__, break_state);
598 
599 	/* LOCKING */
600 	if (break_state)
601 		lcr |= MCT_U232_SET_BREAK;
602 
603 	mct_u232_set_line_ctrl(serial, lcr);
604 }
605 #endif
606 
607 static int klsi_105_tiocmget(struct tty_struct *tty)
608 {
609 	struct usb_serial_port *port = tty->driver_data;
610 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
611 	unsigned long flags;
612 	int rc;
613 	unsigned long line_state;
614 
615 	rc = klsi_105_get_line_state(port, &line_state);
616 	if (rc < 0) {
617 		dev_err(&port->dev,
618 			"Reading line control failed (error = %d)\n", rc);
619 		/* better return value? EAGAIN? */
620 		return rc;
621 	}
622 
623 	spin_lock_irqsave(&priv->lock, flags);
624 	priv->line_state = line_state;
625 	spin_unlock_irqrestore(&priv->lock, flags);
626 	dev_dbg(&port->dev, "%s - read line state 0x%lx\n", __func__, line_state);
627 	return (int)line_state;
628 }
629 
630 static int klsi_105_tiocmset(struct tty_struct *tty,
631 			     unsigned int set, unsigned int clear)
632 {
633 	int retval = -EINVAL;
634 
635 /* if this ever gets implemented, it should be done something like this:
636 	struct usb_serial *serial = port->serial;
637 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
638 	unsigned long flags;
639 	int control;
640 
641 	spin_lock_irqsave (&priv->lock, flags);
642 	if (set & TIOCM_RTS)
643 		priv->control_state |= TIOCM_RTS;
644 	if (set & TIOCM_DTR)
645 		priv->control_state |= TIOCM_DTR;
646 	if (clear & TIOCM_RTS)
647 		priv->control_state &= ~TIOCM_RTS;
648 	if (clear & TIOCM_DTR)
649 		priv->control_state &= ~TIOCM_DTR;
650 	control = priv->control_state;
651 	spin_unlock_irqrestore (&priv->lock, flags);
652 	retval = mct_u232_set_modem_ctrl(serial, control);
653 */
654 	return retval;
655 }
656 
657 module_usb_serial_driver(serial_drivers, id_table);
658 
659 MODULE_AUTHOR(DRIVER_AUTHOR);
660 MODULE_DESCRIPTION(DRIVER_DESC);
661 MODULE_LICENSE("GPL");
662