xref: /openbmc/linux/drivers/usb/serial/belkin_sa.c (revision b627b4ed)
1 /*
2  * Belkin USB Serial Adapter Driver
3  *
4  *  Copyright (C) 2000		William Greathouse (wgreathouse@smva.com)
5  *  Copyright (C) 2000-2001 	Greg Kroah-Hartman (greg@kroah.com)
6  *
7  *  This program is largely derived from work by the linux-usb group
8  *  and associated source files.  Please see the usb/serial files for
9  *  individual credits and copyrights.
10  *
11  * 	This program is free software; you can redistribute it and/or modify
12  * 	it under the terms of the GNU General Public License as published by
13  * 	the Free Software Foundation; either version 2 of the License, or
14  * 	(at your option) any later version.
15  *
16  * See Documentation/usb/usb-serial.txt for more information on using this
17  * driver
18  *
19  * TODO:
20  * -- Add true modem contol line query capability.  Currently we track the
21  *    states reported by the interrupt and the states we request.
22  * -- Add error reporting back to application for UART error conditions.
23  *    Just point me at how to implement this and I'll do it. I've put the
24  *    framework in, but haven't analyzed the "tty_flip" interface yet.
25  * -- Add support for flush commands
26  * -- Add everything that is missing :)
27  *
28  * 27-Nov-2001 gkh
29  * 	compressed all the differnent device entries into 1.
30  *
31  * 30-May-2001 gkh
32  *	switched from using spinlock to a semaphore, which fixes lots of
33  *	problems.
34  *
35  * 08-Apr-2001 gb
36  *	- Identify version on module load.
37  *
38  * 12-Mar-2001 gkh
39  *	- Added support for the GoHubs GO-COM232 device which is the same as the
40  *	  Peracom device.
41  *
42  * 06-Nov-2000 gkh
43  *	- Added support for the old Belkin and Peracom devices.
44  *	- Made the port able to be opened multiple times.
45  *	- Added some defaults incase the line settings are things these devices
46  *	  can't support.
47  *
48  * 18-Oct-2000 William Greathouse
49  *    Released into the wild (linux-usb-devel)
50  *
51  * 17-Oct-2000 William Greathouse
52  *    Add code to recognize firmware version and set hardware flow control
53  *    appropriately.  Belkin states that firmware prior to 3.05 does not
54  *    operate correctly in hardware handshake mode.  I have verified this
55  *    on firmware 2.05 -- for both RTS and DTR input flow control, the control
56  *    line is not reset.  The test performed by the Belkin Win* driver is
57  *    to enable hardware flow control for firmware 2.06 or greater and
58  *    for 1.00 or prior.  I am only enabling for 2.06 or greater.
59  *
60  * 12-Oct-2000 William Greathouse
61  *    First cut at supporting Belkin USB Serial Adapter F5U103
62  *    I did not have a copy of the original work to support this
63  *    adapter, so pardon any stupid mistakes.  All of the information
64  *    I am using to write this driver was acquired by using a modified
65  *    UsbSnoop on Windows2000 and from examining the other USB drivers.
66  */
67 
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 <linux/uaccess.h>
78 #include <linux/usb.h>
79 #include <linux/usb/serial.h>
80 #include "belkin_sa.h"
81 
82 static int debug;
83 
84 /*
85  * Version Information
86  */
87 #define DRIVER_VERSION "v1.2"
88 #define DRIVER_AUTHOR "William Greathouse <wgreathouse@smva.com>"
89 #define DRIVER_DESC "USB Belkin Serial converter driver"
90 
91 /* function prototypes for a Belkin USB Serial Adapter F5U103 */
92 static int  belkin_sa_startup(struct usb_serial *serial);
93 static void belkin_sa_shutdown(struct usb_serial *serial);
94 static int  belkin_sa_open(struct tty_struct *tty,
95 			struct usb_serial_port *port, struct file *filp);
96 static void belkin_sa_close(struct tty_struct *tty,
97 			struct usb_serial_port *port, struct file *filp);
98 static void belkin_sa_read_int_callback(struct urb *urb);
99 static void belkin_sa_set_termios(struct tty_struct *tty,
100 			struct usb_serial_port *port, struct ktermios * old);
101 static void belkin_sa_break_ctl(struct tty_struct *tty, int break_state);
102 static int  belkin_sa_tiocmget(struct tty_struct *tty, struct file *file);
103 static int  belkin_sa_tiocmset(struct tty_struct *tty, struct file *file,
104 					unsigned int set, unsigned int clear);
105 
106 
107 static struct usb_device_id id_table_combined [] = {
108 	{ USB_DEVICE(BELKIN_SA_VID, BELKIN_SA_PID) },
109 	{ USB_DEVICE(BELKIN_OLD_VID, BELKIN_OLD_PID) },
110 	{ USB_DEVICE(PERACOM_VID, PERACOM_PID) },
111 	{ USB_DEVICE(GOHUBS_VID, GOHUBS_PID) },
112 	{ USB_DEVICE(GOHUBS_VID, HANDYLINK_PID) },
113 	{ USB_DEVICE(BELKIN_DOCKSTATION_VID, BELKIN_DOCKSTATION_PID) },
114 	{ }	/* Terminating entry */
115 };
116 
117 MODULE_DEVICE_TABLE(usb, id_table_combined);
118 
119 static struct usb_driver belkin_driver = {
120 	.name =		"belkin",
121 	.probe =	usb_serial_probe,
122 	.disconnect =	usb_serial_disconnect,
123 	.id_table =	id_table_combined,
124 	.no_dynamic_id = 	1,
125 };
126 
127 /* All of the device info needed for the serial converters */
128 static struct usb_serial_driver belkin_device = {
129 	.driver = {
130 		.owner =	THIS_MODULE,
131 		.name =		"belkin",
132 	},
133 	.description =		"Belkin / Peracom / GoHubs USB Serial Adapter",
134 	.usb_driver =		&belkin_driver,
135 	.id_table =		id_table_combined,
136 	.num_ports =		1,
137 	.open =			belkin_sa_open,
138 	.close =		belkin_sa_close,
139 	.read_int_callback =	belkin_sa_read_int_callback,
140 					/* How we get the status info */
141 	.set_termios =		belkin_sa_set_termios,
142 	.break_ctl =		belkin_sa_break_ctl,
143 	.tiocmget =		belkin_sa_tiocmget,
144 	.tiocmset =		belkin_sa_tiocmset,
145 	.attach =		belkin_sa_startup,
146 	.shutdown =		belkin_sa_shutdown,
147 };
148 
149 
150 struct belkin_sa_private {
151 	spinlock_t		lock;
152 	unsigned long		control_state;
153 	unsigned char		last_lsr;
154 	unsigned char		last_msr;
155 	int			bad_flow_control;
156 };
157 
158 
159 /*
160  * ***************************************************************************
161  * Belkin USB Serial Adapter F5U103 specific driver functions
162  * ***************************************************************************
163  */
164 
165 #define WDR_TIMEOUT 5000 /* default urb timeout */
166 
167 /* assumes that struct usb_serial *serial is available */
168 #define BSA_USB_CMD(c, v) usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), \
169 					    (c), BELKIN_SA_SET_REQUEST_TYPE, \
170 					    (v), 0, NULL, 0, WDR_TIMEOUT)
171 
172 /* do some startup allocations not currently performed by usb_serial_probe() */
173 static int belkin_sa_startup(struct usb_serial *serial)
174 {
175 	struct usb_device *dev = serial->dev;
176 	struct belkin_sa_private *priv;
177 
178 	/* allocate the private data structure */
179 	priv = kmalloc(sizeof(struct belkin_sa_private), GFP_KERNEL);
180 	if (!priv)
181 		return -1; /* error */
182 	/* set initial values for control structures */
183 	spin_lock_init(&priv->lock);
184 	priv->control_state = 0;
185 	priv->last_lsr = 0;
186 	priv->last_msr = 0;
187 	/* see comments at top of file */
188 	priv->bad_flow_control =
189 		(le16_to_cpu(dev->descriptor.bcdDevice) <= 0x0206) ? 1 : 0;
190 	dev_info(&dev->dev, "bcdDevice: %04x, bfc: %d\n",
191 					le16_to_cpu(dev->descriptor.bcdDevice),
192 					priv->bad_flow_control);
193 
194 	init_waitqueue_head(&serial->port[0]->write_wait);
195 	usb_set_serial_port_data(serial->port[0], priv);
196 
197 	return 0;
198 }
199 
200 
201 static void belkin_sa_shutdown(struct usb_serial *serial)
202 {
203 	struct belkin_sa_private *priv;
204 	int i;
205 
206 	dbg("%s", __func__);
207 
208 	/* stop reads and writes on all ports */
209 	for (i = 0; i < serial->num_ports; ++i) {
210 		/* My special items, the standard routines free my urbs */
211 		priv = usb_get_serial_port_data(serial->port[i]);
212 		kfree(priv);
213 	}
214 }
215 
216 
217 static int  belkin_sa_open(struct tty_struct *tty,
218 			struct usb_serial_port *port, struct file *filp)
219 {
220 	int retval = 0;
221 
222 	dbg("%s port %d", __func__, port->number);
223 
224 	/*Start reading from the device*/
225 	/* TODO: Look at possibility of submitting multiple URBs to device to
226 	 *       enhance buffering.  Win trace shows 16 initial read URBs.
227 	 */
228 	port->read_urb->dev = port->serial->dev;
229 	retval = usb_submit_urb(port->read_urb, GFP_KERNEL);
230 	if (retval) {
231 		dev_err(&port->dev, "usb_submit_urb(read bulk) failed\n");
232 		goto exit;
233 	}
234 
235 	port->interrupt_in_urb->dev = port->serial->dev;
236 	retval = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
237 	if (retval) {
238 		usb_kill_urb(port->read_urb);
239 		dev_err(&port->dev, "usb_submit_urb(read int) failed\n");
240 	}
241 
242 exit:
243 	return retval;
244 } /* belkin_sa_open */
245 
246 
247 static void belkin_sa_close(struct tty_struct *tty,
248 			struct usb_serial_port *port, struct file *filp)
249 {
250 	dbg("%s port %d", __func__, port->number);
251 
252 	/* shutdown our bulk reads and writes */
253 	usb_kill_urb(port->write_urb);
254 	usb_kill_urb(port->read_urb);
255 	usb_kill_urb(port->interrupt_in_urb);
256 } /* belkin_sa_close */
257 
258 
259 static void belkin_sa_read_int_callback(struct urb *urb)
260 {
261 	struct usb_serial_port *port = urb->context;
262 	struct belkin_sa_private *priv;
263 	unsigned char *data = urb->transfer_buffer;
264 	int retval;
265 	int status = urb->status;
266 	unsigned long flags;
267 
268 	switch (status) {
269 	case 0:
270 		/* success */
271 		break;
272 	case -ECONNRESET:
273 	case -ENOENT:
274 	case -ESHUTDOWN:
275 		/* this urb is terminated, clean up */
276 		dbg("%s - urb shutting down with status: %d",
277 		    __func__, status);
278 		return;
279 	default:
280 		dbg("%s - nonzero urb status received: %d",
281 		    __func__, status);
282 		goto exit;
283 	}
284 
285 	usb_serial_debug_data(debug, &port->dev, __func__,
286 					urb->actual_length, data);
287 
288 	/* Handle known interrupt data */
289 	/* ignore data[0] and data[1] */
290 
291 	priv = usb_get_serial_port_data(port);
292 	spin_lock_irqsave(&priv->lock, flags);
293 	priv->last_msr = data[BELKIN_SA_MSR_INDEX];
294 
295 	/* Record Control Line states */
296 	if (priv->last_msr & BELKIN_SA_MSR_DSR)
297 		priv->control_state |= TIOCM_DSR;
298 	else
299 		priv->control_state &= ~TIOCM_DSR;
300 
301 	if (priv->last_msr & BELKIN_SA_MSR_CTS)
302 		priv->control_state |= TIOCM_CTS;
303 	else
304 		priv->control_state &= ~TIOCM_CTS;
305 
306 	if (priv->last_msr & BELKIN_SA_MSR_RI)
307 		priv->control_state |= TIOCM_RI;
308 	else
309 		priv->control_state &= ~TIOCM_RI;
310 
311 	if (priv->last_msr & BELKIN_SA_MSR_CD)
312 		priv->control_state |= TIOCM_CD;
313 	else
314 		priv->control_state &= ~TIOCM_CD;
315 
316 	/* Now to report any errors */
317 	priv->last_lsr = data[BELKIN_SA_LSR_INDEX];
318 #if 0
319 	/*
320 	 * fill in the flip buffer here, but I do not know the relation
321 	 * to the current/next receive buffer or characters.  I need
322 	 * to look in to this before committing any code.
323 	 */
324 	if (priv->last_lsr & BELKIN_SA_LSR_ERR) {
325 		tty = tty_port_tty_get(&port->port);
326 		/* Overrun Error */
327 		if (priv->last_lsr & BELKIN_SA_LSR_OE) {
328 		}
329 		/* Parity Error */
330 		if (priv->last_lsr & BELKIN_SA_LSR_PE) {
331 		}
332 		/* Framing Error */
333 		if (priv->last_lsr & BELKIN_SA_LSR_FE) {
334 		}
335 		/* Break Indicator */
336 		if (priv->last_lsr & BELKIN_SA_LSR_BI) {
337 		}
338 		tty_kref_put(tty);
339 	}
340 #endif
341 	spin_unlock_irqrestore(&priv->lock, flags);
342 exit:
343 	retval = usb_submit_urb(urb, GFP_ATOMIC);
344 	if (retval)
345 		dev_err(&port->dev, "%s - usb_submit_urb failed with "
346 			"result %d\n", __func__, retval);
347 }
348 
349 static void belkin_sa_set_termios(struct tty_struct *tty,
350 		struct usb_serial_port *port, struct ktermios *old_termios)
351 {
352 	struct usb_serial *serial = port->serial;
353 	struct belkin_sa_private *priv = usb_get_serial_port_data(port);
354 	unsigned int iflag;
355 	unsigned int cflag;
356 	unsigned int old_iflag = 0;
357 	unsigned int old_cflag = 0;
358 	__u16 urb_value = 0; /* Will hold the new flags */
359 	unsigned long flags;
360 	unsigned long control_state;
361 	int bad_flow_control;
362 	speed_t baud;
363 	struct ktermios *termios = tty->termios;
364 
365 	iflag = termios->c_iflag;
366 	cflag = termios->c_cflag;
367 
368 	termios->c_cflag &= ~CMSPAR;
369 
370 	/* get a local copy of the current port settings */
371 	spin_lock_irqsave(&priv->lock, flags);
372 	control_state = priv->control_state;
373 	bad_flow_control = priv->bad_flow_control;
374 	spin_unlock_irqrestore(&priv->lock, flags);
375 
376 	old_iflag = old_termios->c_iflag;
377 	old_cflag = old_termios->c_cflag;
378 
379 	/* Set the baud rate */
380 	if ((cflag & CBAUD) != (old_cflag & CBAUD)) {
381 		/* reassert DTR and (maybe) RTS on transition from B0 */
382 		if ((old_cflag & CBAUD) == B0) {
383 			control_state |= (TIOCM_DTR|TIOCM_RTS);
384 			if (BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, 1) < 0)
385 				dev_err(&port->dev, "Set DTR error\n");
386 			/* don't set RTS if using hardware flow control */
387 			if (!(old_cflag & CRTSCTS))
388 				if (BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST
389 								, 1) < 0)
390 					dev_err(&port->dev, "Set RTS error\n");
391 		}
392 	}
393 
394 	baud = tty_get_baud_rate(tty);
395 	if (baud) {
396 		urb_value = BELKIN_SA_BAUD(baud);
397 		/* Clip to maximum speed */
398 		if (urb_value == 0)
399 			urb_value = 1;
400 		/* Turn it back into a resulting real baud rate */
401 		baud = BELKIN_SA_BAUD(urb_value);
402 
403 		/* Report the actual baud rate back to the caller */
404 		tty_encode_baud_rate(tty, baud, baud);
405 		if (BSA_USB_CMD(BELKIN_SA_SET_BAUDRATE_REQUEST, urb_value) < 0)
406 			dev_err(&port->dev, "Set baudrate error\n");
407 	} else {
408 		/* Disable flow control */
409 		if (BSA_USB_CMD(BELKIN_SA_SET_FLOW_CTRL_REQUEST,
410 						BELKIN_SA_FLOW_NONE) < 0)
411 			dev_err(&port->dev, "Disable flowcontrol error\n");
412 		/* Drop RTS and DTR */
413 		control_state &= ~(TIOCM_DTR | TIOCM_RTS);
414 		if (BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, 0) < 0)
415 			dev_err(&port->dev, "DTR LOW error\n");
416 		if (BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST, 0) < 0)
417 			dev_err(&port->dev, "RTS LOW error\n");
418 	}
419 
420 	/* set the parity */
421 	if ((cflag ^ old_cflag) & (PARENB | PARODD)) {
422 		if (cflag & PARENB)
423 			urb_value = (cflag & PARODD) ?  BELKIN_SA_PARITY_ODD
424 						: BELKIN_SA_PARITY_EVEN;
425 		else
426 			urb_value = BELKIN_SA_PARITY_NONE;
427 		if (BSA_USB_CMD(BELKIN_SA_SET_PARITY_REQUEST, urb_value) < 0)
428 			dev_err(&port->dev, "Set parity error\n");
429 	}
430 
431 	/* set the number of data bits */
432 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
433 		switch (cflag & CSIZE) {
434 		case CS5:
435 			urb_value = BELKIN_SA_DATA_BITS(5);
436 			break;
437 		case CS6:
438 			urb_value = BELKIN_SA_DATA_BITS(6);
439 			break;
440 		case CS7:
441 			urb_value = BELKIN_SA_DATA_BITS(7);
442 			break;
443 		case CS8:
444 			urb_value = BELKIN_SA_DATA_BITS(8);
445 			break;
446 		default: dbg("CSIZE was not CS5-CS8, using default of 8");
447 			urb_value = BELKIN_SA_DATA_BITS(8);
448 			break;
449 		}
450 		if (BSA_USB_CMD(BELKIN_SA_SET_DATA_BITS_REQUEST, urb_value) < 0)
451 			dev_err(&port->dev, "Set data bits error\n");
452 	}
453 
454 	/* set the number of stop bits */
455 	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
456 		urb_value = (cflag & CSTOPB) ? BELKIN_SA_STOP_BITS(2)
457 						: BELKIN_SA_STOP_BITS(1);
458 		if (BSA_USB_CMD(BELKIN_SA_SET_STOP_BITS_REQUEST,
459 							urb_value) < 0)
460 			dev_err(&port->dev, "Set stop bits error\n");
461 	}
462 
463 	/* Set flow control */
464 	if (((iflag ^ old_iflag) & (IXOFF | IXON)) ||
465 		((cflag ^ old_cflag) & CRTSCTS)) {
466 		urb_value = 0;
467 		if ((iflag & IXOFF) || (iflag & IXON))
468 			urb_value |= (BELKIN_SA_FLOW_OXON | BELKIN_SA_FLOW_IXON);
469 		else
470 			urb_value &= ~(BELKIN_SA_FLOW_OXON | BELKIN_SA_FLOW_IXON);
471 
472 		if (cflag & CRTSCTS)
473 			urb_value |=  (BELKIN_SA_FLOW_OCTS | BELKIN_SA_FLOW_IRTS);
474 		else
475 			urb_value &= ~(BELKIN_SA_FLOW_OCTS | BELKIN_SA_FLOW_IRTS);
476 
477 		if (bad_flow_control)
478 			urb_value &= ~(BELKIN_SA_FLOW_IRTS);
479 
480 		if (BSA_USB_CMD(BELKIN_SA_SET_FLOW_CTRL_REQUEST, urb_value) < 0)
481 			dev_err(&port->dev, "Set flow control error\n");
482 	}
483 
484 	/* save off the modified port settings */
485 	spin_lock_irqsave(&priv->lock, flags);
486 	priv->control_state = control_state;
487 	spin_unlock_irqrestore(&priv->lock, flags);
488 } /* belkin_sa_set_termios */
489 
490 
491 static void belkin_sa_break_ctl(struct tty_struct *tty, int break_state)
492 {
493 	struct usb_serial_port *port = tty->driver_data;
494 	struct usb_serial *serial = port->serial;
495 
496 	if (BSA_USB_CMD(BELKIN_SA_SET_BREAK_REQUEST, break_state ? 1 : 0) < 0)
497 		dev_err(&port->dev, "Set break_ctl %d\n", break_state);
498 }
499 
500 
501 static int belkin_sa_tiocmget(struct tty_struct *tty, struct file *file)
502 {
503 	struct usb_serial_port *port = tty->driver_data;
504 	struct belkin_sa_private *priv = usb_get_serial_port_data(port);
505 	unsigned long control_state;
506 	unsigned long flags;
507 
508 	dbg("%s", __func__);
509 
510 	spin_lock_irqsave(&priv->lock, flags);
511 	control_state = priv->control_state;
512 	spin_unlock_irqrestore(&priv->lock, flags);
513 
514 	return control_state;
515 }
516 
517 
518 static int belkin_sa_tiocmset(struct tty_struct *tty, struct file *file,
519 			       unsigned int set, unsigned int clear)
520 {
521 	struct usb_serial_port *port = tty->driver_data;
522 	struct usb_serial *serial = port->serial;
523 	struct belkin_sa_private *priv = usb_get_serial_port_data(port);
524 	unsigned long control_state;
525 	unsigned long flags;
526 	int retval;
527 	int rts = 0;
528 	int dtr = 0;
529 
530 	dbg("%s", __func__);
531 
532 	spin_lock_irqsave(&priv->lock, flags);
533 	control_state = priv->control_state;
534 
535 	if (set & TIOCM_RTS) {
536 		control_state |= TIOCM_RTS;
537 		rts = 1;
538 	}
539 	if (set & TIOCM_DTR) {
540 		control_state |= TIOCM_DTR;
541 		dtr = 1;
542 	}
543 	if (clear & TIOCM_RTS) {
544 		control_state &= ~TIOCM_RTS;
545 		rts = 0;
546 	}
547 	if (clear & TIOCM_DTR) {
548 		control_state &= ~TIOCM_DTR;
549 		dtr = 0;
550 	}
551 
552 	priv->control_state = control_state;
553 	spin_unlock_irqrestore(&priv->lock, flags);
554 
555 	retval = BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST, rts);
556 	if (retval < 0) {
557 		dev_err(&port->dev, "Set RTS error %d\n", retval);
558 		goto exit;
559 	}
560 
561 	retval = BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, dtr);
562 	if (retval < 0) {
563 		dev_err(&port->dev, "Set DTR error %d\n", retval);
564 		goto exit;
565 	}
566 exit:
567 	return retval;
568 }
569 
570 
571 static int __init belkin_sa_init(void)
572 {
573 	int retval;
574 	retval = usb_serial_register(&belkin_device);
575 	if (retval)
576 		goto failed_usb_serial_register;
577 	retval = usb_register(&belkin_driver);
578 	if (retval)
579 		goto failed_usb_register;
580 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
581 	       DRIVER_DESC "\n");
582 	return 0;
583 failed_usb_register:
584 	usb_serial_deregister(&belkin_device);
585 failed_usb_serial_register:
586 	return retval;
587 }
588 
589 
590 static void __exit belkin_sa_exit (void)
591 {
592 	usb_deregister(&belkin_driver);
593 	usb_serial_deregister(&belkin_device);
594 }
595 
596 
597 module_init(belkin_sa_init);
598 module_exit(belkin_sa_exit);
599 
600 MODULE_AUTHOR(DRIVER_AUTHOR);
601 MODULE_DESCRIPTION(DRIVER_DESC);
602 MODULE_VERSION(DRIVER_VERSION);
603 MODULE_LICENSE("GPL");
604 
605 module_param(debug, bool, S_IRUGO | S_IWUSR);
606 MODULE_PARM_DESC(debug, "Debug enabled or not");
607