2 * Silicon Laboratories CP2101/CP2102 USB to RS232 serial adaptor driver
4 * Copyright (C) 2005 Craig Shelley (craig@microtron.org.uk)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License version
8 * 2 as published by the Free Software Foundation.
10 * Support to set flow control line levels using TIOCMGET and TIOCMSET
11 * thanks to Karl Hiramoto karl@hiramoto.org. RTSCTS hardware flow
12 * control thanks to Munir Nassar nassarmu@real-time.com
15 * Buffers are not flushed when the port is opened.
16 * Multiple calls to write() may fail with "Resource temporarily unavailable"
20 #include <linux/kernel.h>
21 #include <linux/errno.h>
22 #include <linux/slab.h>
23 #include <linux/tty.h>
24 #include <linux/tty_flip.h>
25 #include <linux/module.h>
26 #include <linux/moduleparam.h>
27 #include <linux/usb.h>
28 #include <asm/uaccess.h>
29 #include <linux/usb/serial.h>
34 #define DRIVER_VERSION "v0.07"
35 #define DRIVER_DESC "Silicon Labs CP2101/CP2102 RS232 serial adaptor driver"
40 static int cp2101_open(struct usb_serial_port*, struct file*);
41 static void cp2101_cleanup(struct usb_serial_port*);
42 static void cp2101_close(struct usb_serial_port*, struct file*);
43 static void cp2101_get_termios(struct usb_serial_port*);
44 static void cp2101_set_termios(struct usb_serial_port*, struct termios*);
45 static int cp2101_tiocmget (struct usb_serial_port *, struct file *);
46 static int cp2101_tiocmset (struct usb_serial_port *, struct file *,
47 unsigned int, unsigned int);
48 static void cp2101_break_ctl(struct usb_serial_port*, int);
49 static int cp2101_startup (struct usb_serial *);
50 static void cp2101_shutdown(struct usb_serial*);
55 static struct usb_device_id id_table [] = {
56 { USB_DEVICE(0x0FCF, 0x1003) }, /* Dynastream ANT development board */
57 { USB_DEVICE(0x10A6, 0xAA26) }, /* Knock-off DCU-11 cable */
58 { USB_DEVICE(0x10AB, 0x10C5) }, /* Siemens MC60 Cable */
59 { USB_DEVICE(0x10B5, 0xAC70) }, /* Nokia CA-42 USB */
60 { USB_DEVICE(0x10C4, 0x803B) }, /* Pololu USB-serial converter */
61 { USB_DEVICE(0x10C4, 0x8066) }, /* Argussoft In-System Programmer */
62 { USB_DEVICE(0x10C4, 0x807A) }, /* Crumb128 board */
63 { USB_DEVICE(0x10C4, 0x80CA) }, /* Degree Controls Inc */
64 { USB_DEVICE(0x10C4, 0x80F6) }, /* Suunto sports instrument */
65 { USB_DEVICE(0x10C4, 0x813D) }, /* Burnside Telecom Deskmobile */
66 { USB_DEVICE(0x10C4, 0x815E) }, /* Helicomm IP-Link 1220-DVM */
67 { USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
68 { USB_DEVICE(0x16D6, 0x0001) }, /* Jablotron serial interface */
69 { } /* Terminating Entry */
72 MODULE_DEVICE_TABLE (usb, id_table);
74 static struct usb_driver cp2101_driver = {
76 .probe = usb_serial_probe,
77 .disconnect = usb_serial_disconnect,
82 static struct usb_serial_driver cp2101_device = {
88 .num_interrupt_in = 0,
93 .close = cp2101_close,
94 .break_ctl = cp2101_break_ctl,
95 .set_termios = cp2101_set_termios,
96 .tiocmget = cp2101_tiocmget,
97 .tiocmset = cp2101_tiocmset,
98 .attach = cp2101_startup,
99 .shutdown = cp2101_shutdown,
102 /* Config request types */
103 #define REQTYPE_HOST_TO_DEVICE 0x41
104 #define REQTYPE_DEVICE_TO_HOST 0xc1
106 /* Config SET requests. To GET, add 1 to the request number */
107 #define CP2101_UART 0x00 /* Enable / Disable */
108 #define CP2101_BAUDRATE 0x01 /* (BAUD_RATE_GEN_FREQ / baudrate) */
109 #define CP2101_BITS 0x03 /* 0x(0)(databits)(parity)(stopbits) */
110 #define CP2101_BREAK 0x05 /* On / Off */
111 #define CP2101_CONTROL 0x07 /* Flow control line states */
112 #define CP2101_MODEMCTL 0x13 /* Modem controls */
113 #define CP2101_CONFIG_6 0x19 /* 6 bytes of config data ??? */
116 #define UART_ENABLE 0x0001
117 #define UART_DISABLE 0x0000
119 /* CP2101_BAUDRATE */
120 #define BAUD_RATE_GEN_FREQ 0x384000
123 #define BITS_DATA_MASK 0X0f00
124 #define BITS_DATA_5 0X0500
125 #define BITS_DATA_6 0X0600
126 #define BITS_DATA_7 0X0700
127 #define BITS_DATA_8 0X0800
128 #define BITS_DATA_9 0X0900
130 #define BITS_PARITY_MASK 0x00f0
131 #define BITS_PARITY_NONE 0x0000
132 #define BITS_PARITY_ODD 0x0010
133 #define BITS_PARITY_EVEN 0x0020
134 #define BITS_PARITY_MARK 0x0030
135 #define BITS_PARITY_SPACE 0x0040
137 #define BITS_STOP_MASK 0x000f
138 #define BITS_STOP_1 0x0000
139 #define BITS_STOP_1_5 0x0001
140 #define BITS_STOP_2 0x0002
143 #define BREAK_ON 0x0000
144 #define BREAK_OFF 0x0001
147 #define CONTROL_DTR 0x0001
148 #define CONTROL_RTS 0x0002
149 #define CONTROL_CTS 0x0010
150 #define CONTROL_DSR 0x0020
151 #define CONTROL_RING 0x0040
152 #define CONTROL_DCD 0x0080
153 #define CONTROL_WRITE_DTR 0x0100
154 #define CONTROL_WRITE_RTS 0x0200
158 * Reads from the CP2101 configuration registers
159 * 'size' is specified in bytes.
160 * 'data' is a pointer to a pre-allocated array of integers large
161 * enough to hold 'size' bytes (with 4 bytes to each integer)
163 static int cp2101_get_config(struct usb_serial_port* port, u8 request,
164 unsigned int *data, int size)
166 struct usb_serial *serial = port->serial;
168 int result, i, length;
170 /* Number of integers required to contain the array */
171 length = (((size - 1) | 3) + 1)/4;
173 buf = kcalloc(length, sizeof(u32), GFP_KERNEL);
175 dev_err(&port->dev, "%s - out of memory.\n", __FUNCTION__);
179 /* For get requests, the request number must be incremented */
182 /* Issue the request, attempting to read 'size' bytes */
183 result = usb_control_msg (serial->dev,usb_rcvctrlpipe (serial->dev, 0),
184 request, REQTYPE_DEVICE_TO_HOST, 0x0000,
187 /* Convert data into an array of integers */
188 for (i=0; i<length; i++)
189 data[i] = le32_to_cpu(buf[i]);
193 if (result != size) {
194 dev_err(&port->dev, "%s - Unable to send config request, "
195 "request=0x%x size=%d result=%d\n",
196 __FUNCTION__, request, size, result);
205 * Writes to the CP2101 configuration registers
206 * Values less than 16 bits wide are sent directly
207 * 'size' is specified in bytes.
209 static int cp2101_set_config(struct usb_serial_port* port, u8 request,
210 unsigned int *data, int size)
212 struct usb_serial *serial = port->serial;
214 int result, i, length;
216 /* Number of integers required to contain the array */
217 length = (((size - 1) | 3) + 1)/4;
219 buf = kmalloc(length * sizeof(u32), GFP_KERNEL);
221 dev_err(&port->dev, "%s - out of memory.\n",
226 /* Array of integers into bytes */
227 for (i = 0; i < length; i++)
228 buf[i] = cpu_to_le32(data[i]);
231 result = usb_control_msg (serial->dev,
232 usb_sndctrlpipe(serial->dev, 0),
233 request, REQTYPE_HOST_TO_DEVICE, 0x0000,
236 result = usb_control_msg (serial->dev,
237 usb_sndctrlpipe(serial->dev, 0),
238 request, REQTYPE_HOST_TO_DEVICE, data[0],
244 if ((size > 2 && result != size) || result < 0) {
245 dev_err(&port->dev, "%s - Unable to send request, "
246 "request=0x%x size=%d result=%d\n",
247 __FUNCTION__, request, size, result);
251 /* Single data value */
252 result = usb_control_msg (serial->dev,
253 usb_sndctrlpipe(serial->dev, 0),
254 request, REQTYPE_HOST_TO_DEVICE, data[0],
260 * cp2101_set_config_single
261 * Convenience function for calling cp2101_set_config on single data values
262 * without requiring an integer pointer
264 static inline int cp2101_set_config_single(struct usb_serial_port* port,
265 u8 request, unsigned int data)
267 return cp2101_set_config(port, request, &data, 2);
270 static int cp2101_open (struct usb_serial_port *port, struct file *filp)
272 struct usb_serial *serial = port->serial;
275 dbg("%s - port %d", __FUNCTION__, port->number);
277 if (cp2101_set_config_single(port, CP2101_UART, UART_ENABLE)) {
278 dev_err(&port->dev, "%s - Unable to enable UART\n",
283 /* Start reading from the device */
284 usb_fill_bulk_urb (port->read_urb, serial->dev,
285 usb_rcvbulkpipe(serial->dev,
286 port->bulk_in_endpointAddress),
287 port->read_urb->transfer_buffer,
288 port->read_urb->transfer_buffer_length,
289 serial->type->read_bulk_callback,
291 result = usb_submit_urb(port->read_urb, GFP_KERNEL);
293 dev_err(&port->dev, "%s - failed resubmitting read urb, "
294 "error %d\n", __FUNCTION__, result);
298 /* Configure the termios structure */
299 cp2101_get_termios(port);
301 /* Set the DTR and RTS pins low */
302 cp2101_tiocmset(port, NULL, TIOCM_DTR | TIOCM_RTS, 0);
307 static void cp2101_cleanup (struct usb_serial_port *port)
309 struct usb_serial *serial = port->serial;
311 dbg("%s - port %d", __FUNCTION__, port->number);
314 /* shutdown any bulk reads that might be going on */
315 if (serial->num_bulk_out)
316 usb_kill_urb(port->write_urb);
317 if (serial->num_bulk_in)
318 usb_kill_urb(port->read_urb);
322 static void cp2101_close (struct usb_serial_port *port, struct file * filp)
324 dbg("%s - port %d", __FUNCTION__, port->number);
326 /* shutdown our urbs */
327 dbg("%s - shutting down urbs", __FUNCTION__);
328 usb_kill_urb(port->write_urb);
329 usb_kill_urb(port->read_urb);
331 cp2101_set_config_single(port, CP2101_UART, UART_DISABLE);
336 * Reads the baud rate, data bits, parity, stop bits and flow control mode
337 * from the device, corrects any unsupported values, and configures the
338 * termios structure to reflect the state of the device
340 static void cp2101_get_termios (struct usb_serial_port *port)
342 unsigned int cflag, modem_ctl[4];
346 dbg("%s - port %d", __FUNCTION__, port->number);
348 if ((!port->tty) || (!port->tty->termios)) {
349 dbg("%s - no tty structures", __FUNCTION__);
352 cflag = port->tty->termios->c_cflag;
354 cp2101_get_config(port, CP2101_BAUDRATE, &baud, 2);
355 /* Convert to baudrate */
357 baud = BAUD_RATE_GEN_FREQ / baud;
359 dbg("%s - baud rate = %d", __FUNCTION__, baud);
363 * The baud rates which are commented out below
364 * appear to be supported by the device
365 * but are non-standard
367 case 600: cflag |= B600; break;
368 case 1200: cflag |= B1200; break;
369 case 1800: cflag |= B1800; break;
370 case 2400: cflag |= B2400; break;
371 case 4800: cflag |= B4800; break;
372 /*case 7200: cflag |= B7200; break;*/
373 case 9600: cflag |= B9600; break;
374 /*case 14400: cflag |= B14400; break;*/
375 case 19200: cflag |= B19200; break;
376 /*case 28800: cflag |= B28800; break;*/
377 case 38400: cflag |= B38400; break;
378 /*case 55854: cflag |= B55054; break;*/
379 case 57600: cflag |= B57600; break;
380 case 115200: cflag |= B115200; break;
381 /*case 127117: cflag |= B127117; break;*/
382 case 230400: cflag |= B230400; break;
383 case 460800: cflag |= B460800; break;
384 case 921600: cflag |= B921600; break;
385 /*case 3686400: cflag |= B3686400; break;*/
387 dbg("%s - Baud rate is not supported, "
388 "using 9600 baud", __FUNCTION__);
390 cp2101_set_config_single(port, CP2101_BAUDRATE,
391 (BAUD_RATE_GEN_FREQ/9600));
395 cp2101_get_config(port, CP2101_BITS, &bits, 2);
397 switch(bits & BITS_DATA_MASK) {
399 dbg("%s - data bits = 5", __FUNCTION__);
403 dbg("%s - data bits = 6", __FUNCTION__);
407 dbg("%s - data bits = 7", __FUNCTION__);
411 dbg("%s - data bits = 8", __FUNCTION__);
415 dbg("%s - data bits = 9 (not supported, "
416 "using 8 data bits)", __FUNCTION__);
418 bits &= ~BITS_DATA_MASK;
420 cp2101_set_config(port, CP2101_BITS, &bits, 2);
423 dbg("%s - Unknown number of data bits, "
424 "using 8", __FUNCTION__);
426 bits &= ~BITS_DATA_MASK;
428 cp2101_set_config(port, CP2101_BITS, &bits, 2);
432 switch(bits & BITS_PARITY_MASK) {
433 case BITS_PARITY_NONE:
434 dbg("%s - parity = NONE", __FUNCTION__);
437 case BITS_PARITY_ODD:
438 dbg("%s - parity = ODD", __FUNCTION__);
439 cflag |= (PARENB|PARODD);
441 case BITS_PARITY_EVEN:
442 dbg("%s - parity = EVEN", __FUNCTION__);
446 case BITS_PARITY_MARK:
447 dbg("%s - parity = MARK (not supported, "
448 "disabling parity)", __FUNCTION__);
450 bits &= ~BITS_PARITY_MASK;
451 cp2101_set_config(port, CP2101_BITS, &bits, 2);
453 case BITS_PARITY_SPACE:
454 dbg("%s - parity = SPACE (not supported, "
455 "disabling parity)", __FUNCTION__);
457 bits &= ~BITS_PARITY_MASK;
458 cp2101_set_config(port, CP2101_BITS, &bits, 2);
461 dbg("%s - Unknown parity mode, "
462 "disabling parity", __FUNCTION__);
464 bits &= ~BITS_PARITY_MASK;
465 cp2101_set_config(port, CP2101_BITS, &bits, 2);
470 switch(bits & BITS_STOP_MASK) {
472 dbg("%s - stop bits = 1", __FUNCTION__);
475 dbg("%s - stop bits = 1.5 (not supported, "
476 "using 1 stop bit)", __FUNCTION__);
477 bits &= ~BITS_STOP_MASK;
478 cp2101_set_config(port, CP2101_BITS, &bits, 2);
481 dbg("%s - stop bits = 2", __FUNCTION__);
485 dbg("%s - Unknown number of stop bits, "
486 "using 1 stop bit", __FUNCTION__);
487 bits &= ~BITS_STOP_MASK;
488 cp2101_set_config(port, CP2101_BITS, &bits, 2);
492 cp2101_get_config(port, CP2101_MODEMCTL, modem_ctl, 16);
493 if (modem_ctl[0] & 0x0008) {
494 dbg("%s - flow control = CRTSCTS", __FUNCTION__);
497 dbg("%s - flow control = NONE", __FUNCTION__);
501 port->tty->termios->c_cflag = cflag;
504 static void cp2101_set_termios (struct usb_serial_port *port,
505 struct termios *old_termios)
507 unsigned int cflag, old_cflag=0;
509 unsigned int modem_ctl[4];
511 dbg("%s - port %d", __FUNCTION__, port->number);
513 if ((!port->tty) || (!port->tty->termios)) {
514 dbg("%s - no tty structures", __FUNCTION__);
517 cflag = port->tty->termios->c_cflag;
519 /* Check that they really want us to change something */
521 if ((cflag == old_termios->c_cflag) &&
522 (RELEVANT_IFLAG(port->tty->termios->c_iflag)
523 == RELEVANT_IFLAG(old_termios->c_iflag))) {
524 dbg("%s - nothing to change...", __FUNCTION__);
528 old_cflag = old_termios->c_cflag;
531 /* If the baud rate is to be updated*/
532 if ((cflag & CBAUD) != (old_cflag & CBAUD)) {
533 switch (cflag & CBAUD) {
535 * The baud rates which are commented out below
536 * appear to be supported by the device
537 * but are non-standard
539 case B0: baud = 0; break;
540 case B600: baud = 600; break;
541 case B1200: baud = 1200; break;
542 case B1800: baud = 1800; break;
543 case B2400: baud = 2400; break;
544 case B4800: baud = 4800; break;
545 /*case B7200: baud = 7200; break;*/
546 case B9600: baud = 9600; break;
547 /*ase B14400: baud = 14400; break;*/
548 case B19200: baud = 19200; break;
549 /*case B28800: baud = 28800; break;*/
550 case B38400: baud = 38400; break;
551 /*case B55854: baud = 55054; break;*/
552 case B57600: baud = 57600; break;
553 case B115200: baud = 115200; break;
554 /*case B127117: baud = 127117; break;*/
555 case B230400: baud = 230400; break;
556 case B460800: baud = 460800; break;
557 case B921600: baud = 921600; break;
558 /*case B3686400: baud = 3686400; break;*/
560 dev_err(&port->dev, "cp2101 driver does not "
561 "support the baudrate requested\n");
566 dbg("%s - Setting baud rate to %d baud", __FUNCTION__,
568 if (cp2101_set_config_single(port, CP2101_BAUDRATE,
569 (BAUD_RATE_GEN_FREQ / baud)))
570 dev_err(&port->dev, "Baud rate requested not "
571 "supported by device\n");
575 /* If the number of data bits is to be updated */
576 if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
577 cp2101_get_config(port, CP2101_BITS, &bits, 2);
578 bits &= ~BITS_DATA_MASK;
579 switch (cflag & CSIZE) {
582 dbg("%s - data bits = 5", __FUNCTION__);
586 dbg("%s - data bits = 6", __FUNCTION__);
590 dbg("%s - data bits = 7", __FUNCTION__);
594 dbg("%s - data bits = 8", __FUNCTION__);
598 dbg("%s - data bits = 9", __FUNCTION__);
601 dev_err(&port->dev, "cp2101 driver does not "
602 "support the number of bits requested,"
603 " using 8 bit mode\n");
607 if (cp2101_set_config(port, CP2101_BITS, &bits, 2))
608 dev_err(&port->dev, "Number of data bits requested "
609 "not supported by device\n");
612 if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))) {
613 cp2101_get_config(port, CP2101_BITS, &bits, 2);
614 bits &= ~BITS_PARITY_MASK;
615 if (cflag & PARENB) {
616 if (cflag & PARODD) {
617 bits |= BITS_PARITY_ODD;
618 dbg("%s - parity = ODD", __FUNCTION__);
620 bits |= BITS_PARITY_EVEN;
621 dbg("%s - parity = EVEN", __FUNCTION__);
624 if (cp2101_set_config(port, CP2101_BITS, &bits, 2))
625 dev_err(&port->dev, "Parity mode not supported "
629 if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
630 cp2101_get_config(port, CP2101_BITS, &bits, 2);
631 bits &= ~BITS_STOP_MASK;
632 if (cflag & CSTOPB) {
634 dbg("%s - stop bits = 2", __FUNCTION__);
637 dbg("%s - stop bits = 1", __FUNCTION__);
639 if (cp2101_set_config(port, CP2101_BITS, &bits, 2))
640 dev_err(&port->dev, "Number of stop bits requested "
641 "not supported by device\n");
644 if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
645 cp2101_get_config(port, CP2101_MODEMCTL, modem_ctl, 16);
646 dbg("%s - read modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x",
647 __FUNCTION__, modem_ctl[0], modem_ctl[1],
648 modem_ctl[2], modem_ctl[3]);
650 if (cflag & CRTSCTS) {
651 modem_ctl[0] &= ~0x7B;
652 modem_ctl[0] |= 0x09;
654 dbg("%s - flow control = CRTSCTS", __FUNCTION__);
656 modem_ctl[0] &= ~0x7B;
657 modem_ctl[0] |= 0x01;
658 modem_ctl[1] |= 0x40;
659 dbg("%s - flow control = NONE", __FUNCTION__);
662 dbg("%s - write modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x",
663 __FUNCTION__, modem_ctl[0], modem_ctl[1],
664 modem_ctl[2], modem_ctl[3]);
665 cp2101_set_config(port, CP2101_MODEMCTL, modem_ctl, 16);
670 static int cp2101_tiocmset (struct usb_serial_port *port, struct file *file,
671 unsigned int set, unsigned int clear)
675 dbg("%s - port %d", __FUNCTION__, port->number);
677 if (set & TIOCM_RTS) {
678 control |= CONTROL_RTS;
679 control |= CONTROL_WRITE_RTS;
681 if (set & TIOCM_DTR) {
682 control |= CONTROL_DTR;
683 control |= CONTROL_WRITE_DTR;
685 if (clear & TIOCM_RTS) {
686 control &= ~CONTROL_RTS;
687 control |= CONTROL_WRITE_RTS;
689 if (clear & TIOCM_DTR) {
690 control &= ~CONTROL_DTR;
691 control |= CONTROL_WRITE_DTR;
694 dbg("%s - control = 0x%.4x", __FUNCTION__, control);
696 return cp2101_set_config(port, CP2101_CONTROL, &control, 2);
700 static int cp2101_tiocmget (struct usb_serial_port *port, struct file *file)
704 dbg("%s - port %d", __FUNCTION__, port->number);
706 cp2101_get_config(port, CP2101_CONTROL, &control, 1);
708 result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
709 |((control & CONTROL_RTS) ? TIOCM_RTS : 0)
710 |((control & CONTROL_CTS) ? TIOCM_CTS : 0)
711 |((control & CONTROL_DSR) ? TIOCM_DSR : 0)
712 |((control & CONTROL_RING)? TIOCM_RI : 0)
713 |((control & CONTROL_DCD) ? TIOCM_CD : 0);
715 dbg("%s - control = 0x%.2x", __FUNCTION__, control);
720 static void cp2101_break_ctl (struct usb_serial_port *port, int break_state)
724 dbg("%s - port %d", __FUNCTION__, port->number);
725 if (break_state == 0)
729 dbg("%s - turning break %s", __FUNCTION__,
730 state==BREAK_OFF ? "off" : "on");
731 cp2101_set_config(port, CP2101_BREAK, &state, 2);
734 static int cp2101_startup (struct usb_serial *serial)
736 /* CP2101 buffers behave strangely unless device is reset */
737 usb_reset_device(serial->dev);
741 static void cp2101_shutdown (struct usb_serial *serial)
745 dbg("%s", __FUNCTION__);
747 /* Stop reads and writes on all ports */
748 for (i=0; i < serial->num_ports; ++i) {
749 cp2101_cleanup(serial->port[i]);
753 static int __init cp2101_init (void)
757 retval = usb_serial_register(&cp2101_device);
759 return retval; /* Failed to register */
761 retval = usb_register(&cp2101_driver);
763 /* Failed to register */
764 usb_serial_deregister(&cp2101_device);
769 info(DRIVER_DESC " " DRIVER_VERSION);
773 static void __exit cp2101_exit (void)
775 usb_deregister (&cp2101_driver);
776 usb_serial_deregister (&cp2101_device);
779 module_init(cp2101_init);
780 module_exit(cp2101_exit);
782 MODULE_DESCRIPTION(DRIVER_DESC);
783 MODULE_VERSION(DRIVER_VERSION);
784 MODULE_LICENSE("GPL");
786 module_param(debug, bool, S_IRUGO | S_IWUSR);
787 MODULE_PARM_DESC(debug, "Enable verbose debugging messages");