/* * Silicon Laboratories CP2101/CP2102 USB to RS232 serial adaptor driver * * Copyright (C) 2005 Craig Shelley (craig@microtron.org.uk) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License version * 2 as published by the Free Software Foundation. * * Support to set flow control line levels using TIOCMGET and TIOCMSET * thanks to Karl Hiramoto karl@hiramoto.org. RTSCTS hardware flow * control thanks to Munir Nassar nassarmu@real-time.com * * Outstanding Issues: * Buffers are not flushed when the port is opened. * Multiple calls to write() may fail with "Resource temporarily unavailable" * */ #include #include #include #include #include #include #include #include #include #include /* * Version Information */ #define DRIVER_VERSION "v0.07" #define DRIVER_DESC "Silicon Labs CP2101/CP2102 RS232 serial adaptor driver" /* * Function Prototypes */ static int cp2101_open(struct usb_serial_port*, struct file*); static void cp2101_cleanup(struct usb_serial_port*); static void cp2101_close(struct usb_serial_port*, struct file*); static void cp2101_get_termios(struct usb_serial_port*); static void cp2101_set_termios(struct usb_serial_port*, struct termios*); static int cp2101_tiocmget (struct usb_serial_port *, struct file *); static int cp2101_tiocmset (struct usb_serial_port *, struct file *, unsigned int, unsigned int); static void cp2101_break_ctl(struct usb_serial_port*, int); static int cp2101_startup (struct usb_serial *); static void cp2101_shutdown(struct usb_serial*); static int debug; static struct usb_device_id id_table [] = { { USB_DEVICE(0x0FCF, 0x1003) }, /* Dynastream ANT development board */ { USB_DEVICE(0x10A6, 0xAA26) }, /* Knock-off DCU-11 cable */ { USB_DEVICE(0x10AB, 0x10C5) }, /* Siemens MC60 Cable */ { USB_DEVICE(0x10B5, 0xAC70) }, /* Nokia CA-42 USB */ { USB_DEVICE(0x10C4, 0x803B) }, /* Pololu USB-serial converter */ { USB_DEVICE(0x10C4, 0x8066) }, /* Argussoft In-System Programmer */ { USB_DEVICE(0x10C4, 0x807A) }, /* Crumb128 board */ { USB_DEVICE(0x10C4, 0x80CA) }, /* Degree Controls Inc */ { USB_DEVICE(0x10C4, 0x80F6) }, /* Suunto sports instrument */ { USB_DEVICE(0x10C4, 0x813D) }, /* Burnside Telecom Deskmobile */ { USB_DEVICE(0x10C4, 0x815E) }, /* Helicomm IP-Link 1220-DVM */ { USB_DEVICE(0x10C4, 0x81C8) }, /* Lipowsky Industrie Elektronik GmbH, Baby-JTAG */ { USB_DEVICE(0x10C4, 0x81E2) }, /* Lipowsky Industrie Elektronik GmbH, Baby-LIN */ { USB_DEVICE(0x10C4, 0x8218) }, /* Lipowsky Industrie Elektronik GmbH, HARP-1 */ { USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */ { USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory default */ { USB_DEVICE(0x16D6, 0x0001) }, /* Jablotron serial interface */ { } /* Terminating Entry */ }; MODULE_DEVICE_TABLE (usb, id_table); static struct usb_driver cp2101_driver = { .name = "cp2101", .probe = usb_serial_probe, .disconnect = usb_serial_disconnect, .id_table = id_table, .no_dynamic_id = 1, }; static struct usb_serial_driver cp2101_device = { .driver = { .owner = THIS_MODULE, .name = "cp2101", }, .id_table = id_table, .num_interrupt_in = 0, .num_bulk_in = 0, .num_bulk_out = 0, .num_ports = 1, .open = cp2101_open, .close = cp2101_close, .break_ctl = cp2101_break_ctl, .set_termios = cp2101_set_termios, .tiocmget = cp2101_tiocmget, .tiocmset = cp2101_tiocmset, .attach = cp2101_startup, .shutdown = cp2101_shutdown, }; /* Config request types */ #define REQTYPE_HOST_TO_DEVICE 0x41 #define REQTYPE_DEVICE_TO_HOST 0xc1 /* Config SET requests. To GET, add 1 to the request number */ #define CP2101_UART 0x00 /* Enable / Disable */ #define CP2101_BAUDRATE 0x01 /* (BAUD_RATE_GEN_FREQ / baudrate) */ #define CP2101_BITS 0x03 /* 0x(0)(databits)(parity)(stopbits) */ #define CP2101_BREAK 0x05 /* On / Off */ #define CP2101_CONTROL 0x07 /* Flow control line states */ #define CP2101_MODEMCTL 0x13 /* Modem controls */ #define CP2101_CONFIG_6 0x19 /* 6 bytes of config data ??? */ /* CP2101_UART */ #define UART_ENABLE 0x0001 #define UART_DISABLE 0x0000 /* CP2101_BAUDRATE */ #define BAUD_RATE_GEN_FREQ 0x384000 /* CP2101_BITS */ #define BITS_DATA_MASK 0X0f00 #define BITS_DATA_5 0X0500 #define BITS_DATA_6 0X0600 #define BITS_DATA_7 0X0700 #define BITS_DATA_8 0X0800 #define BITS_DATA_9 0X0900 #define BITS_PARITY_MASK 0x00f0 #define BITS_PARITY_NONE 0x0000 #define BITS_PARITY_ODD 0x0010 #define BITS_PARITY_EVEN 0x0020 #define BITS_PARITY_MARK 0x0030 #define BITS_PARITY_SPACE 0x0040 #define BITS_STOP_MASK 0x000f #define BITS_STOP_1 0x0000 #define BITS_STOP_1_5 0x0001 #define BITS_STOP_2 0x0002 /* CP2101_BREAK */ #define BREAK_ON 0x0000 #define BREAK_OFF 0x0001 /* CP2101_CONTROL */ #define CONTROL_DTR 0x0001 #define CONTROL_RTS 0x0002 #define CONTROL_CTS 0x0010 #define CONTROL_DSR 0x0020 #define CONTROL_RING 0x0040 #define CONTROL_DCD 0x0080 #define CONTROL_WRITE_DTR 0x0100 #define CONTROL_WRITE_RTS 0x0200 /* * cp2101_get_config * Reads from the CP2101 configuration registers * 'size' is specified in bytes. * 'data' is a pointer to a pre-allocated array of integers large * enough to hold 'size' bytes (with 4 bytes to each integer) */ static int cp2101_get_config(struct usb_serial_port* port, u8 request, unsigned int *data, int size) { struct usb_serial *serial = port->serial; u32 *buf; int result, i, length; /* Number of integers required to contain the array */ length = (((size - 1) | 3) + 1)/4; buf = kcalloc(length, sizeof(u32), GFP_KERNEL); if (!buf) { dev_err(&port->dev, "%s - out of memory.\n", __FUNCTION__); return -ENOMEM; } /* For get requests, the request number must be incremented */ request++; /* Issue the request, attempting to read 'size' bytes */ result = usb_control_msg (serial->dev,usb_rcvctrlpipe (serial->dev, 0), request, REQTYPE_DEVICE_TO_HOST, 0x0000, 0, buf, size, 300); /* Convert data into an array of integers */ for (i=0; idev, "%s - Unable to send config request, " "request=0x%x size=%d result=%d\n", __FUNCTION__, request, size, result); return -EPROTO; } return 0; } /* * cp2101_set_config * Writes to the CP2101 configuration registers * Values less than 16 bits wide are sent directly * 'size' is specified in bytes. */ static int cp2101_set_config(struct usb_serial_port* port, u8 request, unsigned int *data, int size) { struct usb_serial *serial = port->serial; u32 *buf; int result, i, length; /* Number of integers required to contain the array */ length = (((size - 1) | 3) + 1)/4; buf = kmalloc(length * sizeof(u32), GFP_KERNEL); if (!buf) { dev_err(&port->dev, "%s - out of memory.\n", __FUNCTION__); return -ENOMEM; } /* Array of integers into bytes */ for (i = 0; i < length; i++) buf[i] = cpu_to_le32(data[i]); if (size > 2) { result = usb_control_msg (serial->dev, usb_sndctrlpipe(serial->dev, 0), request, REQTYPE_HOST_TO_DEVICE, 0x0000, 0, buf, size, 300); } else { result = usb_control_msg (serial->dev, usb_sndctrlpipe(serial->dev, 0), request, REQTYPE_HOST_TO_DEVICE, data[0], 0, NULL, 0, 300); } kfree(buf); if ((size > 2 && result != size) || result < 0) { dev_err(&port->dev, "%s - Unable to send request, " "request=0x%x size=%d result=%d\n", __FUNCTION__, request, size, result); return -EPROTO; } /* Single data value */ result = usb_control_msg (serial->dev, usb_sndctrlpipe(serial->dev, 0), request, REQTYPE_HOST_TO_DEVICE, data[0], 0, NULL, 0, 300); return 0; } /* * cp2101_set_config_single * Convenience function for calling cp2101_set_config on single data values * without requiring an integer pointer */ static inline int cp2101_set_config_single(struct usb_serial_port* port, u8 request, unsigned int data) { return cp2101_set_config(port, request, &data, 2); } static int cp2101_open (struct usb_serial_port *port, struct file *filp) { struct usb_serial *serial = port->serial; int result; dbg("%s - port %d", __FUNCTION__, port->number); if (cp2101_set_config_single(port, CP2101_UART, UART_ENABLE)) { dev_err(&port->dev, "%s - Unable to enable UART\n", __FUNCTION__); return -EPROTO; } /* Start reading from the device */ usb_fill_bulk_urb (port->read_urb, serial->dev, usb_rcvbulkpipe(serial->dev, port->bulk_in_endpointAddress), port->read_urb->transfer_buffer, port->read_urb->transfer_buffer_length, serial->type->read_bulk_callback, port); result = usb_submit_urb(port->read_urb, GFP_KERNEL); if (result) { dev_err(&port->dev, "%s - failed resubmitting read urb, " "error %d\n", __FUNCTION__, result); return result; } /* Configure the termios structure */ cp2101_get_termios(port); /* Set the DTR and RTS pins low */ cp2101_tiocmset(port, NULL, TIOCM_DTR | TIOCM_RTS, 0); return 0; } static void cp2101_cleanup (struct usb_serial_port *port) { struct usb_serial *serial = port->serial; dbg("%s - port %d", __FUNCTION__, port->number); if (serial->dev) { /* shutdown any bulk reads that might be going on */ if (serial->num_bulk_out) usb_kill_urb(port->write_urb); if (serial->num_bulk_in) usb_kill_urb(port->read_urb); } } static void cp2101_close (struct usb_serial_port *port, struct file * filp) { dbg("%s - port %d", __FUNCTION__, port->number); /* shutdown our urbs */ dbg("%s - shutting down urbs", __FUNCTION__); usb_kill_urb(port->write_urb); usb_kill_urb(port->read_urb); cp2101_set_config_single(port, CP2101_UART, UART_DISABLE); } /* * cp2101_get_termios * Reads the baud rate, data bits, parity, stop bits and flow control mode * from the device, corrects any unsupported values, and configures the * termios structure to reflect the state of the device */ static void cp2101_get_termios (struct usb_serial_port *port) { unsigned int cflag, modem_ctl[4]; int baud; int bits; dbg("%s - port %d", __FUNCTION__, port->number); if ((!port->tty) || (!port->tty->termios)) { dbg("%s - no tty structures", __FUNCTION__); return; } cflag = port->tty->termios->c_cflag; cp2101_get_config(port, CP2101_BAUDRATE, &baud, 2); /* Convert to baudrate */ if (baud) baud = BAUD_RATE_GEN_FREQ / baud; dbg("%s - baud rate = %d", __FUNCTION__, baud); cflag &= ~CBAUD; switch (baud) { /* * The baud rates which are commented out below * appear to be supported by the device * but are non-standard */ case 600: cflag |= B600; break; case 1200: cflag |= B1200; break; case 1800: cflag |= B1800; break; case 2400: cflag |= B2400; break; case 4800: cflag |= B4800; break; /*case 7200: cflag |= B7200; break;*/ case 9600: cflag |= B9600; break; /*case 14400: cflag |= B14400; break;*/ case 19200: cflag |= B19200; break; /*case 28800: cflag |= B28800; break;*/ case 38400: cflag |= B38400; break; /*case 55854: cflag |= B55054; break;*/ case 57600: cflag |= B57600; break; case 115200: cflag |= B115200; break; /*case 127117: cflag |= B127117; break;*/ case 230400: cflag |= B230400; break; case 460800: cflag |= B460800; break; case 921600: cflag |= B921600; break; /*case 3686400: cflag |= B3686400; break;*/ default: dbg("%s - Baud rate is not supported, " "using 9600 baud", __FUNCTION__); cflag |= B9600; cp2101_set_config_single(port, CP2101_BAUDRATE, (BAUD_RATE_GEN_FREQ/9600)); break; } cp2101_get_config(port, CP2101_BITS, &bits, 2); cflag &= ~CSIZE; switch(bits & BITS_DATA_MASK) { case BITS_DATA_5: dbg("%s - data bits = 5", __FUNCTION__); cflag |= CS5; break; case BITS_DATA_6: dbg("%s - data bits = 6", __FUNCTION__); cflag |= CS6; break; case BITS_DATA_7: dbg("%s - data bits = 7", __FUNCTION__); cflag |= CS7; break; case BITS_DATA_8: dbg("%s - data bits = 8", __FUNCTION__); cflag |= CS8; break; case BITS_DATA_9: dbg("%s - data bits = 9 (not supported, " "using 8 data bits)", __FUNCTION__); cflag |= CS8; bits &= ~BITS_DATA_MASK; bits |= BITS_DATA_8; cp2101_set_config(port, CP2101_BITS, &bits, 2); break; default: dbg("%s - Unknown number of data bits, " "using 8", __FUNCTION__); cflag |= CS8; bits &= ~BITS_DATA_MASK; bits |= BITS_DATA_8; cp2101_set_config(port, CP2101_BITS, &bits, 2); break; } switch(bits & BITS_PARITY_MASK) { case BITS_PARITY_NONE: dbg("%s - parity = NONE", __FUNCTION__); cflag &= ~PARENB; break; case BITS_PARITY_ODD: dbg("%s - parity = ODD", __FUNCTION__); cflag |= (PARENB|PARODD); break; case BITS_PARITY_EVEN: dbg("%s - parity = EVEN", __FUNCTION__); cflag &= ~PARODD; cflag |= PARENB; break; case BITS_PARITY_MARK: dbg("%s - parity = MARK (not supported, " "disabling parity)", __FUNCTION__); cflag &= ~PARENB; bits &= ~BITS_PARITY_MASK; cp2101_set_config(port, CP2101_BITS, &bits, 2); break; case BITS_PARITY_SPACE: dbg("%s - parity = SPACE (not supported, " "disabling parity)", __FUNCTION__); cflag &= ~PARENB; bits &= ~BITS_PARITY_MASK; cp2101_set_config(port, CP2101_BITS, &bits, 2); break; default: dbg("%s - Unknown parity mode, " "disabling parity", __FUNCTION__); cflag &= ~PARENB; bits &= ~BITS_PARITY_MASK; cp2101_set_config(port, CP2101_BITS, &bits, 2); break; } cflag &= ~CSTOPB; switch(bits & BITS_STOP_MASK) { case BITS_STOP_1: dbg("%s - stop bits = 1", __FUNCTION__); break; case BITS_STOP_1_5: dbg("%s - stop bits = 1.5 (not supported, " "using 1 stop bit)", __FUNCTION__); bits &= ~BITS_STOP_MASK; cp2101_set_config(port, CP2101_BITS, &bits, 2); break; case BITS_STOP_2: dbg("%s - stop bits = 2", __FUNCTION__); cflag |= CSTOPB; break; default: dbg("%s - Unknown number of stop bits, " "using 1 stop bit", __FUNCTION__); bits &= ~BITS_STOP_MASK; cp2101_set_config(port, CP2101_BITS, &bits, 2); break; } cp2101_get_config(port, CP2101_MODEMCTL, modem_ctl, 16); if (modem_ctl[0] & 0x0008) { dbg("%s - flow control = CRTSCTS", __FUNCTION__); cflag |= CRTSCTS; } else { dbg("%s - flow control = NONE", __FUNCTION__); cflag &= ~CRTSCTS; } port->tty->termios->c_cflag = cflag; } static void cp2101_set_termios (struct usb_serial_port *port, struct termios *old_termios) { unsigned int cflag, old_cflag=0; int baud=0, bits; unsigned int modem_ctl[4]; dbg("%s - port %d", __FUNCTION__, port->number); if ((!port->tty) || (!port->tty->termios)) { dbg("%s - no tty structures", __FUNCTION__); return; } cflag = port->tty->termios->c_cflag; /* Check that they really want us to change something */ if (old_termios) { if ((cflag == old_termios->c_cflag) && (RELEVANT_IFLAG(port->tty->termios->c_iflag) == RELEVANT_IFLAG(old_termios->c_iflag))) { dbg("%s - nothing to change...", __FUNCTION__); return; } old_cflag = old_termios->c_cflag; } /* If the baud rate is to be updated*/ if ((cflag & CBAUD) != (old_cflag & CBAUD)) { switch (cflag & CBAUD) { /* * The baud rates which are commented out below * appear to be supported by the device * but are non-standard */ case B0: baud = 0; break; case B600: baud = 600; break; case B1200: baud = 1200; break; case B1800: baud = 1800; break; case B2400: baud = 2400; break; case B4800: baud = 4800; break; /*case B7200: baud = 7200; break;*/ case B9600: baud = 9600; break; /*ase B14400: baud = 14400; break;*/ case B19200: baud = 19200; break; /*case B28800: baud = 28800; break;*/ case B38400: baud = 38400; break; /*case B55854: baud = 55054; break;*/ case B57600: baud = 57600; break; case B115200: baud = 115200; break; /*case B127117: baud = 127117; break;*/ case B230400: baud = 230400; break; case B460800: baud = 460800; break; case B921600: baud = 921600; break; /*case B3686400: baud = 3686400; break;*/ default: dev_err(&port->dev, "cp2101 driver does not " "support the baudrate requested\n"); break; } if (baud) { dbg("%s - Setting baud rate to %d baud", __FUNCTION__, baud); if (cp2101_set_config_single(port, CP2101_BAUDRATE, (BAUD_RATE_GEN_FREQ / baud))) dev_err(&port->dev, "Baud rate requested not " "supported by device\n"); } } /* If the number of data bits is to be updated */ if ((cflag & CSIZE) != (old_cflag & CSIZE)) { cp2101_get_config(port, CP2101_BITS, &bits, 2); bits &= ~BITS_DATA_MASK; switch (cflag & CSIZE) { case CS5: bits |= BITS_DATA_5; dbg("%s - data bits = 5", __FUNCTION__); break; case CS6: bits |= BITS_DATA_6; dbg("%s - data bits = 6", __FUNCTION__); break; case CS7: bits |= BITS_DATA_7; dbg("%s - data bits = 7", __FUNCTION__); break; case CS8: bits |= BITS_DATA_8; dbg("%s - data bits = 8", __FUNCTION__); break; /*case CS9: bits |= BITS_DATA_9; dbg("%s - data bits = 9", __FUNCTION__); break;*/ default: dev_err(&port->dev, "cp2101 driver does not " "support the number of bits requested," " using 8 bit mode\n"); bits |= BITS_DATA_8; break; } if (cp2101_set_config(port, CP2101_BITS, &bits, 2)) dev_err(&port->dev, "Number of data bits requested " "not supported by device\n"); } if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))) { cp2101_get_config(port, CP2101_BITS, &bits, 2); bits &= ~BITS_PARITY_MASK; if (cflag & PARENB) { if (cflag & PARODD) { bits |= BITS_PARITY_ODD; dbg("%s - parity = ODD", __FUNCTION__); } else { bits |= BITS_PARITY_EVEN; dbg("%s - parity = EVEN", __FUNCTION__); } } if (cp2101_set_config(port, CP2101_BITS, &bits, 2)) dev_err(&port->dev, "Parity mode not supported " "by device\n"); } if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) { cp2101_get_config(port, CP2101_BITS, &bits, 2); bits &= ~BITS_STOP_MASK; if (cflag & CSTOPB) { bits |= BITS_STOP_2; dbg("%s - stop bits = 2", __FUNCTION__); } else { bits |= BITS_STOP_1; dbg("%s - stop bits = 1", __FUNCTION__); } if (cp2101_set_config(port, CP2101_BITS, &bits, 2)) dev_err(&port->dev, "Number of stop bits requested " "not supported by device\n"); } if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) { cp2101_get_config(port, CP2101_MODEMCTL, modem_ctl, 16); dbg("%s - read modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x", __FUNCTION__, modem_ctl[0], modem_ctl[1], modem_ctl[2], modem_ctl[3]); if (cflag & CRTSCTS) { modem_ctl[0] &= ~0x7B; modem_ctl[0] |= 0x09; modem_ctl[1] = 0x80; dbg("%s - flow control = CRTSCTS", __FUNCTION__); } else { modem_ctl[0] &= ~0x7B; modem_ctl[0] |= 0x01; modem_ctl[1] |= 0x40; dbg("%s - flow control = NONE", __FUNCTION__); } dbg("%s - write modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x", __FUNCTION__, modem_ctl[0], modem_ctl[1], modem_ctl[2], modem_ctl[3]); cp2101_set_config(port, CP2101_MODEMCTL, modem_ctl, 16); } } static int cp2101_tiocmset (struct usb_serial_port *port, struct file *file, unsigned int set, unsigned int clear) { int control = 0; dbg("%s - port %d", __FUNCTION__, port->number); if (set & TIOCM_RTS) { control |= CONTROL_RTS; control |= CONTROL_WRITE_RTS; } if (set & TIOCM_DTR) { control |= CONTROL_DTR; control |= CONTROL_WRITE_DTR; } if (clear & TIOCM_RTS) { control &= ~CONTROL_RTS; control |= CONTROL_WRITE_RTS; } if (clear & TIOCM_DTR) { control &= ~CONTROL_DTR; control |= CONTROL_WRITE_DTR; } dbg("%s - control = 0x%.4x", __FUNCTION__, control); return cp2101_set_config(port, CP2101_CONTROL, &control, 2); } static int cp2101_tiocmget (struct usb_serial_port *port, struct file *file) { int control, result; dbg("%s - port %d", __FUNCTION__, port->number); cp2101_get_config(port, CP2101_CONTROL, &control, 1); result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0) |((control & CONTROL_RTS) ? TIOCM_RTS : 0) |((control & CONTROL_CTS) ? TIOCM_CTS : 0) |((control & CONTROL_DSR) ? TIOCM_DSR : 0) |((control & CONTROL_RING)? TIOCM_RI : 0) |((control & CONTROL_DCD) ? TIOCM_CD : 0); dbg("%s - control = 0x%.2x", __FUNCTION__, control); return result; } static void cp2101_break_ctl (struct usb_serial_port *port, int break_state) { int state; dbg("%s - port %d", __FUNCTION__, port->number); if (break_state == 0) state = BREAK_OFF; else state = BREAK_ON; dbg("%s - turning break %s", __FUNCTION__, state==BREAK_OFF ? "off" : "on"); cp2101_set_config(port, CP2101_BREAK, &state, 2); } static int cp2101_startup (struct usb_serial *serial) { /* CP2101 buffers behave strangely unless device is reset */ usb_reset_device(serial->dev); return 0; } static void cp2101_shutdown (struct usb_serial *serial) { int i; dbg("%s", __FUNCTION__); /* Stop reads and writes on all ports */ for (i=0; i < serial->num_ports; ++i) { cp2101_cleanup(serial->port[i]); } } static int __init cp2101_init (void) { int retval; retval = usb_serial_register(&cp2101_device); if (retval) return retval; /* Failed to register */ retval = usb_register(&cp2101_driver); if (retval) { /* Failed to register */ usb_serial_deregister(&cp2101_device); return retval; } /* Success */ info(DRIVER_DESC " " DRIVER_VERSION); return 0; } static void __exit cp2101_exit (void) { usb_deregister (&cp2101_driver); usb_serial_deregister (&cp2101_device); } module_init(cp2101_init); module_exit(cp2101_exit); MODULE_DESCRIPTION(DRIVER_DESC); MODULE_VERSION(DRIVER_VERSION); MODULE_LICENSE("GPL"); module_param(debug, bool, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(debug, "Enable verbose debugging messages");