drivers/usb/serial/belkin_sa.c

   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");