xref: /openbmc/linux/drivers/usb/serial/kl5kusb105.c (revision 32078f915d1acab356080b144aa89fe3487f3979)
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 bool 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,
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 	.id_table =	id_table,
92 };
93 
94 static struct usb_serial_driver kl5kusb105d_device = {
95 	.driver = {
96 		.owner =	THIS_MODULE,
97 		.name =		"kl5kusb105d",
98 	},
99 	.description =		"KL5KUSB105D / PalmConnect",
100 	.id_table =		id_table,
101 	.num_ports =		1,
102 	.bulk_out_size =	64,
103 	.open =			klsi_105_open,
104 	.close =		klsi_105_close,
105 	.set_termios =		klsi_105_set_termios,
106 	/*.break_ctl =		klsi_105_break_ctl,*/
107 	.tiocmget =		klsi_105_tiocmget,
108 	.tiocmset =		klsi_105_tiocmset,
109 	.attach =		klsi_105_startup,
110 	.release =		klsi_105_release,
111 	.throttle =		usb_serial_generic_throttle,
112 	.unthrottle =		usb_serial_generic_unthrottle,
113 	.process_read_urb =	klsi_105_process_read_urb,
114 	.prepare_write_buffer =	klsi_105_prepare_write_buffer,
115 };
116 
117 static struct usb_serial_driver * const serial_drivers[] = {
118 	&kl5kusb105d_device, NULL
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 	for (i = 0; i < serial->num_ports; ++i)
284 		kfree(usb_get_serial_port_data(serial->port[i]));
285 }
286 
287 static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port)
288 {
289 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
290 	int retval = 0;
291 	int rc;
292 	int i;
293 	unsigned long line_state;
294 	struct klsi_105_port_settings *cfg;
295 	unsigned long flags;
296 
297 	/* Do a defined restart:
298 	 * Set up sane default baud rate and send the 'READ_ON'
299 	 * vendor command.
300 	 * FIXME: set modem line control (how?)
301 	 * Then read the modem line control and store values in
302 	 * priv->line_state.
303 	 */
304 	cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
305 	if (!cfg) {
306 		dev_err(&port->dev, "%s - out of memory for config buffer.\n",
307 				__func__);
308 		return -ENOMEM;
309 	}
310 	cfg->pktlen   = 5;
311 	cfg->baudrate = kl5kusb105a_sio_b9600;
312 	cfg->databits = kl5kusb105a_dtb_8;
313 	cfg->unknown1 = 0;
314 	cfg->unknown2 = 1;
315 	klsi_105_chg_port_settings(port, cfg);
316 
317 	/* set up termios structure */
318 	spin_lock_irqsave(&priv->lock, flags);
319 	priv->termios.c_iflag = tty->termios->c_iflag;
320 	priv->termios.c_oflag = tty->termios->c_oflag;
321 	priv->termios.c_cflag = tty->termios->c_cflag;
322 	priv->termios.c_lflag = tty->termios->c_lflag;
323 	for (i = 0; i < NCCS; i++)
324 		priv->termios.c_cc[i] = tty->termios->c_cc[i];
325 	priv->cfg.pktlen   = cfg->pktlen;
326 	priv->cfg.baudrate = cfg->baudrate;
327 	priv->cfg.databits = cfg->databits;
328 	priv->cfg.unknown1 = cfg->unknown1;
329 	priv->cfg.unknown2 = cfg->unknown2;
330 	spin_unlock_irqrestore(&priv->lock, flags);
331 
332 	/* READ_ON and urb submission */
333 	rc = usb_serial_generic_open(tty, port);
334 	if (rc) {
335 		retval = rc;
336 		goto exit;
337 	}
338 
339 	rc = usb_control_msg(port->serial->dev,
340 			     usb_sndctrlpipe(port->serial->dev, 0),
341 			     KL5KUSB105A_SIO_CONFIGURE,
342 			     USB_TYPE_VENDOR|USB_DIR_OUT|USB_RECIP_INTERFACE,
343 			     KL5KUSB105A_SIO_CONFIGURE_READ_ON,
344 			     0, /* index */
345 			     NULL,
346 			     0,
347 			     KLSI_TIMEOUT);
348 	if (rc < 0) {
349 		dev_err(&port->dev, "Enabling read failed (error = %d)\n", rc);
350 		retval = rc;
351 	} else
352 		dbg("%s - enabled reading", __func__);
353 
354 	rc = klsi_105_get_line_state(port, &line_state);
355 	if (rc >= 0) {
356 		spin_lock_irqsave(&priv->lock, flags);
357 		priv->line_state = line_state;
358 		spin_unlock_irqrestore(&priv->lock, flags);
359 		dbg("%s - read line state 0x%lx", __func__, line_state);
360 		retval = 0;
361 	} else
362 		retval = rc;
363 
364 exit:
365 	kfree(cfg);
366 	return retval;
367 }
368 
369 static void klsi_105_close(struct usb_serial_port *port)
370 {
371 	int rc;
372 
373 	mutex_lock(&port->serial->disc_mutex);
374 	if (!port->serial->disconnected) {
375 		/* send READ_OFF */
376 		rc = usb_control_msg(port->serial->dev,
377 				     usb_sndctrlpipe(port->serial->dev, 0),
378 				     KL5KUSB105A_SIO_CONFIGURE,
379 				     USB_TYPE_VENDOR | USB_DIR_OUT,
380 				     KL5KUSB105A_SIO_CONFIGURE_READ_OFF,
381 				     0, /* index */
382 				     NULL, 0,
383 				     KLSI_TIMEOUT);
384 		if (rc < 0)
385 			dev_err(&port->dev,
386 				"Disabling read failed (error = %d)\n", rc);
387 	}
388 	mutex_unlock(&port->serial->disc_mutex);
389 
390 	/* shutdown our bulk reads and writes */
391 	usb_serial_generic_close(port);
392 
393 	/* wgg - do I need this? I think so. */
394 	usb_kill_urb(port->interrupt_in_urb);
395 }
396 
397 /* We need to write a complete 64-byte data block and encode the
398  * number actually sent in the first double-byte, LSB-order. That
399  * leaves at most 62 bytes of payload.
400  */
401 #define KLSI_HDR_LEN		2
402 static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
403 						void *dest, size_t size)
404 {
405 	unsigned char *buf = dest;
406 	int count;
407 
408 	count = kfifo_out_locked(&port->write_fifo, buf + KLSI_HDR_LEN, size,
409 								&port->lock);
410 	put_unaligned_le16(count, buf);
411 
412 	return count + KLSI_HDR_LEN;
413 }
414 
415 /* The data received is preceded by a length double-byte in LSB-first order.
416  */
417 static void klsi_105_process_read_urb(struct urb *urb)
418 {
419 	struct usb_serial_port *port = urb->context;
420 	unsigned char *data = urb->transfer_buffer;
421 	struct tty_struct *tty;
422 	unsigned len;
423 
424 	/* empty urbs seem to happen, we ignore them */
425 	if (!urb->actual_length)
426 		return;
427 
428 	if (urb->actual_length <= KLSI_HDR_LEN) {
429 		dbg("%s - malformed packet", __func__);
430 		return;
431 	}
432 
433 	tty = tty_port_tty_get(&port->port);
434 	if (!tty)
435 		return;
436 
437 	len = get_unaligned_le16(data);
438 	if (len > urb->actual_length - KLSI_HDR_LEN) {
439 		dbg("%s - packet length mismatch", __func__);
440 		len = urb->actual_length - KLSI_HDR_LEN;
441 	}
442 
443 	tty_insert_flip_string(tty, data + KLSI_HDR_LEN, len);
444 	tty_flip_buffer_push(tty);
445 	tty_kref_put(tty);
446 }
447 
448 static void klsi_105_set_termios(struct tty_struct *tty,
449 				 struct usb_serial_port *port,
450 				 struct ktermios *old_termios)
451 {
452 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
453 	unsigned int iflag = tty->termios->c_iflag;
454 	unsigned int old_iflag = old_termios->c_iflag;
455 	unsigned int cflag = tty->termios->c_cflag;
456 	unsigned int old_cflag = old_termios->c_cflag;
457 	struct klsi_105_port_settings *cfg;
458 	unsigned long flags;
459 	speed_t baud;
460 
461 	cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
462 	if (!cfg) {
463 		dev_err(&port->dev, "%s - out of memory for config buffer.\n",
464 				__func__);
465 		return;
466 	}
467 
468 	/* lock while we are modifying the settings */
469 	spin_lock_irqsave(&priv->lock, flags);
470 
471 	/*
472 	 * Update baud rate
473 	 */
474 	baud = tty_get_baud_rate(tty);
475 
476 	if ((cflag & CBAUD) != (old_cflag & CBAUD)) {
477 		/* reassert DTR and (maybe) RTS on transition from B0 */
478 		if ((old_cflag & CBAUD) == B0) {
479 			dbg("%s: baud was B0", __func__);
480 #if 0
481 			priv->control_state |= TIOCM_DTR;
482 			/* don't set RTS if using hardware flow control */
483 			if (!(old_cflag & CRTSCTS))
484 				priv->control_state |= TIOCM_RTS;
485 			mct_u232_set_modem_ctrl(serial, priv->control_state);
486 #endif
487 		}
488 	}
489 	switch (baud) {
490 	case 0: /* handled below */
491 		break;
492 	case 1200:
493 		priv->cfg.baudrate = kl5kusb105a_sio_b1200;
494 		break;
495 	case 2400:
496 		priv->cfg.baudrate = kl5kusb105a_sio_b2400;
497 		break;
498 	case 4800:
499 		priv->cfg.baudrate = kl5kusb105a_sio_b4800;
500 		break;
501 	case 9600:
502 		priv->cfg.baudrate = kl5kusb105a_sio_b9600;
503 		break;
504 	case 19200:
505 		priv->cfg.baudrate = kl5kusb105a_sio_b19200;
506 		break;
507 	case 38400:
508 		priv->cfg.baudrate = kl5kusb105a_sio_b38400;
509 		break;
510 	case 57600:
511 		priv->cfg.baudrate = kl5kusb105a_sio_b57600;
512 		break;
513 	case 115200:
514 		priv->cfg.baudrate = kl5kusb105a_sio_b115200;
515 		break;
516 	default:
517 		dbg("KLSI USB->Serial converter:"
518 		    " unsupported baudrate request, using default of 9600");
519 			priv->cfg.baudrate = kl5kusb105a_sio_b9600;
520 		baud = 9600;
521 		break;
522 	}
523 	if ((cflag & CBAUD) == B0) {
524 		dbg("%s: baud is B0", __func__);
525 		/* Drop RTS and DTR */
526 		/* maybe this should be simulated by sending read
527 		 * disable and read enable messages?
528 		 */
529 		;
530 #if 0
531 		priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
532 		mct_u232_set_modem_ctrl(serial, priv->control_state);
533 #endif
534 	}
535 	tty_encode_baud_rate(tty, baud, baud);
536 
537 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
538 		/* set the number of data bits */
539 		switch (cflag & CSIZE) {
540 		case CS5:
541 			dbg("%s - 5 bits/byte not supported", __func__);
542 			spin_unlock_irqrestore(&priv->lock, flags);
543 			goto err;
544 		case CS6:
545 			dbg("%s - 6 bits/byte not supported", __func__);
546 			spin_unlock_irqrestore(&priv->lock, flags);
547 			goto err;
548 		case CS7:
549 			priv->cfg.databits = kl5kusb105a_dtb_7;
550 			break;
551 		case CS8:
552 			priv->cfg.databits = kl5kusb105a_dtb_8;
553 			break;
554 		default:
555 			dev_err(&port->dev,
556 				"CSIZE was not CS5-CS8, using default of 8\n");
557 			priv->cfg.databits = kl5kusb105a_dtb_8;
558 			break;
559 		}
560 	}
561 
562 	/*
563 	 * Update line control register (LCR)
564 	 */
565 	if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))
566 	    || (cflag & CSTOPB) != (old_cflag & CSTOPB)) {
567 		/* Not currently supported */
568 		tty->termios->c_cflag &= ~(PARENB|PARODD|CSTOPB);
569 #if 0
570 		priv->last_lcr = 0;
571 
572 		/* set the parity */
573 		if (cflag & PARENB)
574 			priv->last_lcr |= (cflag & PARODD) ?
575 				MCT_U232_PARITY_ODD : MCT_U232_PARITY_EVEN;
576 		else
577 			priv->last_lcr |= MCT_U232_PARITY_NONE;
578 
579 		/* set the number of stop bits */
580 		priv->last_lcr |= (cflag & CSTOPB) ?
581 			MCT_U232_STOP_BITS_2 : MCT_U232_STOP_BITS_1;
582 
583 		mct_u232_set_line_ctrl(serial, priv->last_lcr);
584 #endif
585 		;
586 	}
587 	/*
588 	 * Set flow control: well, I do not really now how to handle DTR/RTS.
589 	 * Just do what we have seen with SniffUSB on Win98.
590 	 */
591 	if ((iflag & IXOFF) != (old_iflag & IXOFF)
592 	    || (iflag & IXON) != (old_iflag & IXON)
593 	    ||  (cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
594 		/* Not currently supported */
595 		tty->termios->c_cflag &= ~CRTSCTS;
596 		/* Drop DTR/RTS if no flow control otherwise assert */
597 #if 0
598 		if ((iflag & IXOFF) || (iflag & IXON) || (cflag & CRTSCTS))
599 			priv->control_state |= TIOCM_DTR | TIOCM_RTS;
600 		else
601 			priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
602 		mct_u232_set_modem_ctrl(serial, priv->control_state);
603 #endif
604 		;
605 	}
606 	memcpy(cfg, &priv->cfg, sizeof(*cfg));
607 	spin_unlock_irqrestore(&priv->lock, flags);
608 
609 	/* now commit changes to device */
610 	klsi_105_chg_port_settings(port, cfg);
611 err:
612 	kfree(cfg);
613 }
614 
615 #if 0
616 static void mct_u232_break_ctl(struct tty_struct *tty, int break_state)
617 {
618 	struct usb_serial_port *port = tty->driver_data;
619 	struct usb_serial *serial = port->serial;
620 	struct mct_u232_private *priv =
621 				(struct mct_u232_private *)port->private;
622 	unsigned char lcr = priv->last_lcr;
623 
624 	dbg("%sstate=%d", __func__, break_state);
625 
626 	/* LOCKING */
627 	if (break_state)
628 		lcr |= MCT_U232_SET_BREAK;
629 
630 	mct_u232_set_line_ctrl(serial, lcr);
631 }
632 #endif
633 
634 static int klsi_105_tiocmget(struct tty_struct *tty)
635 {
636 	struct usb_serial_port *port = tty->driver_data;
637 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
638 	unsigned long flags;
639 	int rc;
640 	unsigned long line_state;
641 
642 	rc = klsi_105_get_line_state(port, &line_state);
643 	if (rc < 0) {
644 		dev_err(&port->dev,
645 			"Reading line control failed (error = %d)\n", rc);
646 		/* better return value? EAGAIN? */
647 		return rc;
648 	}
649 
650 	spin_lock_irqsave(&priv->lock, flags);
651 	priv->line_state = line_state;
652 	spin_unlock_irqrestore(&priv->lock, flags);
653 	dbg("%s - read line state 0x%lx", __func__, line_state);
654 	return (int)line_state;
655 }
656 
657 static int klsi_105_tiocmset(struct tty_struct *tty,
658 			     unsigned int set, unsigned int clear)
659 {
660 	int retval = -EINVAL;
661 
662 /* if this ever gets implemented, it should be done something like this:
663 	struct usb_serial *serial = port->serial;
664 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
665 	unsigned long flags;
666 	int control;
667 
668 	spin_lock_irqsave (&priv->lock, flags);
669 	if (set & TIOCM_RTS)
670 		priv->control_state |= TIOCM_RTS;
671 	if (set & TIOCM_DTR)
672 		priv->control_state |= TIOCM_DTR;
673 	if (clear & TIOCM_RTS)
674 		priv->control_state &= ~TIOCM_RTS;
675 	if (clear & TIOCM_DTR)
676 		priv->control_state &= ~TIOCM_DTR;
677 	control = priv->control_state;
678 	spin_unlock_irqrestore (&priv->lock, flags);
679 	retval = mct_u232_set_modem_ctrl(serial, control);
680 */
681 	return retval;
682 }
683 
684 module_usb_serial_driver(kl5kusb105d_driver, serial_drivers);
685 
686 MODULE_AUTHOR(DRIVER_AUTHOR);
687 MODULE_DESCRIPTION(DRIVER_DESC);
688 MODULE_LICENSE("GPL");
689 
690 module_param(debug, bool, S_IRUGO | S_IWUSR);
691 MODULE_PARM_DESC(debug, "enable extensive debugging messages");
692