drivers/usb/serial/ssu100.c

   1 /*
   2  * usb-serial driver for Quatech SSU-100
   3  *
   4  * based on ftdi_sio.c and the original serqt_usb.c from Quatech
   5  *
   6  */
   7
   8 #include <linux/errno.h>
   9 #include <linux/init.h>
  10 #include <linux/slab.h>
  11 #include <linux/tty.h>
  12 #include <linux/tty_driver.h>
  13 #include <linux/tty_flip.h>
  14 #include <linux/module.h>
  15 #include <linux/serial.h>
  16 #include <linux/usb.h>
  17 #include <linux/usb/serial.h>
  18 #include <linux/serial_reg.h>
  19 #include <linux/uaccess.h>
  20
  21 #define QT_OPEN_CLOSE_CHANNEL       0xca
  22 #define QT_SET_GET_DEVICE           0xc2
  23 #define QT_SET_GET_REGISTER         0xc0
  24 #define QT_GET_SET_PREBUF_TRIG_LVL  0xcc
  25 #define QT_SET_ATF                  0xcd
  26 #define QT_GET_SET_UART             0xc1
  27 #define QT_TRANSFER_IN              0xc0
  28 #define QT_HW_FLOW_CONTROL_MASK     0xc5
  29 #define QT_SW_FLOW_CONTROL_MASK     0xc6
  30
  31 #define  SERIAL_MSR_MASK            0xf0
  32
  33 #define  SERIAL_CRTSCTS ((UART_MCR_RTS << 8) | UART_MSR_CTS)
  34
  35 #define  SERIAL_EVEN_PARITY         (UART_LCR_PARITY | UART_LCR_EPAR)
  36
  37 #define  MAX_BAUD_RATE              460800
  38
  39 #define ATC_DISABLED                0x00
  40 #define DUPMODE_BITS        0xc0
  41 #define RR_BITS             0x03
  42 #define LOOPMODE_BITS       0x41
  43 #define RS232_MODE          0x00
  44 #define RTSCTS_TO_CONNECTOR 0x40
  45 #define CLKS_X4             0x02
  46 #define FULLPWRBIT          0x00000080
  47 #define NEXT_BOARD_POWER_BIT        0x00000004
  48
  49 static int debug = 1;
  50
  51 /* Version Information */
  52 #define DRIVER_VERSION "v0.1"
  53 #define DRIVER_DESC "Quatech SSU-100 USB to Serial Driver"
  54
  55 #define USB_VENDOR_ID_QUATECH   0x061d  /* Quatech VID */
  56 #define QUATECH_SSU100  0xC020  /* SSU100 */
  57
  58 static const struct usb_device_id id_table[] = {
  59         {USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_SSU100)},
  60         {}                      /* Terminating entry */
  61 };
  62
  63 MODULE_DEVICE_TABLE(usb, id_table);
  64
  65
  66 static struct usb_driver ssu100_driver = {
  67         .name                          = "ssu100",
  68         .probe                         = usb_serial_probe,
  69         .disconnect                    = usb_serial_disconnect,
  70         .id_table                      = id_table,
  71         .suspend                       = usb_serial_suspend,
  72         .resume                        = usb_serial_resume,
  73         .no_dynamic_id                 = 1,
  74         .supports_autosuspend          = 1,
  75 };
  76
  77 struct ssu100_port_private {
  78         spinlock_t status_lock;
  79         u8 shadowLSR;
  80         u8 shadowMSR;
  81         wait_queue_head_t delta_msr_wait; /* Used for TIOCMIWAIT */
  82         unsigned short max_packet_size;
  83 };
  84
  85 static void ssu100_release(struct usb_serial *serial)
  86 {
  87         struct ssu100_port_private *priv = usb_get_serial_port_data(*serial->port);
  88
  89         dbg("%s", __func__);
  90         kfree(priv);
  91 }
  92
  93 static inline int ssu100_control_msg(struct usb_device *dev,
  94                                      u8 request, u16 data, u16 index)
  95 {
  96         return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
  97                                request, 0x40, data, index,
  98                                NULL, 0, 300);
  99 }
 100
 101 static inline int ssu100_setdevice(struct usb_device *dev, u8 *data)
 102 {
 103         u16 x = ((u16)(data[1] << 8) | (u16)(data[0]));
 104
 105         return ssu100_control_msg(dev, QT_SET_GET_DEVICE, x, 0);
 106 }
 107
 108
 109 static inline int ssu100_getdevice(struct usb_device *dev, u8 *data)
 110 {
 111         return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 112                                QT_SET_GET_DEVICE, 0xc0, 0, 0,
 113                                data, 3, 300);
 114 }
 115
 116 static inline int ssu100_getregister(struct usb_device *dev,
 117                                      unsigned short uart,
 118                                      unsigned short reg,
 119                                      u8 *data)
 120 {
 121         return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 122                                QT_SET_GET_REGISTER, 0xc0, reg,
 123                                uart, data, sizeof(*data), 300);
 124
 125 }
 126
 127
 128 static inline int ssu100_setregister(struct usb_device *dev,
 129                                      unsigned short uart,
 130                                      u16 data)
 131 {
 132         u16 value = (data << 8) | UART_MCR;
 133
 134         return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
 135                                QT_SET_GET_REGISTER, 0x40, value, uart,
 136                                NULL, 0, 300);
 137
 138 }
 139
 140 #define set_mctrl(dev, set)             update_mctrl((dev), (set), 0)
 141 #define clear_mctrl(dev, clear) update_mctrl((dev), 0, (clear))
 142
 143 /* these do not deal with device that have more than 1 port */
 144 static inline int update_mctrl(struct usb_device *dev, unsigned int set,
 145                                unsigned int clear)
 146 {
 147         unsigned urb_value;
 148         int result;
 149
 150         if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0) {
 151                 dbg("%s - DTR|RTS not being set|cleared", __func__);
 152                 return 0;       /* no change */
 153         }
 154
 155         clear &= ~set;  /* 'set' takes precedence over 'clear' */
 156         urb_value = 0;
 157         if (set & TIOCM_DTR)
 158                 urb_value |= UART_MCR_DTR;
 159         if (set & TIOCM_RTS)
 160                 urb_value |= UART_MCR_RTS;
 161
 162         result = ssu100_setregister(dev, 0, urb_value);
 163         if (result < 0)
 164                 dbg("%s Error from MODEM_CTRL urb", __func__);
 165
 166         return result;
 167 }
 168
 169 static int ssu100_initdevice(struct usb_device *dev)
 170 {
 171         u8 *data;
 172         int result = 0;
 173
 174         dbg("%s", __func__);
 175
 176         data = kzalloc(3, GFP_KERNEL);
 177         if (!data)
 178                 return -ENOMEM;
 179
 180         result = ssu100_getdevice(dev, data);
 181         if (result < 0) {
 182                 dbg("%s - get_device failed %i", __func__, result);
 183                 goto out;
 184         }
 185
 186         data[1] &= ~FULLPWRBIT;
 187
 188         result = ssu100_setdevice(dev, data);
 189         if (result < 0) {
 190                 dbg("%s - setdevice failed %i", __func__, result);
 191                 goto out;
 192         }
 193
 194         result = ssu100_control_msg(dev, QT_GET_SET_PREBUF_TRIG_LVL, 128, 0);
 195         if (result < 0) {
 196                 dbg("%s - set prebuffer level failed %i", __func__, result);
 197                 goto out;
 198         }
 199
 200         result = ssu100_control_msg(dev, QT_SET_ATF, ATC_DISABLED, 0);
 201         if (result < 0) {
 202                 dbg("%s - set ATFprebuffer level failed %i", __func__, result);
 203                 goto out;
 204         }
 205
 206         result = ssu100_getdevice(dev, data);
 207         if (result < 0) {
 208                 dbg("%s - get_device failed %i", __func__, result);
 209                 goto out;
 210         }
 211
 212         data[0] &= ~(RR_BITS | DUPMODE_BITS);
 213         data[0] |= CLKS_X4;
 214         data[1] &= ~(LOOPMODE_BITS);
 215         data[1] |= RS232_MODE;
 216
 217         result = ssu100_setdevice(dev, data);
 218         if (result < 0) {
 219                 dbg("%s - setdevice failed %i", __func__, result);
 220                 goto out;
 221         }
 222
 223 out:    kfree(data);
 224         return result;
 225
 226 }
 227
 228
 229 static void ssu100_set_termios(struct tty_struct *tty,
 230                                struct usb_serial_port *port,
 231                                struct ktermios *old_termios)
 232 {
 233         struct usb_device *dev = port->serial->dev;
 234         struct ktermios *termios = tty->termios;
 235         u16 baud, divisor, remainder;
 236         unsigned int cflag = termios->c_cflag;
 237         u16 urb_value = 0; /* will hold the new flags */
 238         int result;
 239
 240         dbg("%s", __func__);
 241
 242         if (cflag & PARENB) {
 243                 if (cflag & PARODD)
 244                         urb_value |= UART_LCR_PARITY;
 245                 else
 246                         urb_value |= SERIAL_EVEN_PARITY;
 247         }
 248
 249         switch (cflag & CSIZE) {
 250         case CS5:
 251                 urb_value |= UART_LCR_WLEN5;
 252                 break;
 253         case CS6:
 254                 urb_value |= UART_LCR_WLEN6;
 255                 break;
 256         case CS7:
 257                 urb_value |= UART_LCR_WLEN7;
 258                 break;
 259         default:
 260         case CS8:
 261                 urb_value |= UART_LCR_WLEN8;
 262                 break;
 263         }
 264
 265         baud = tty_get_baud_rate(tty);
 266         if (!baud)
 267                 baud = 9600;
 268
 269         dbg("%s - got baud = %d\n", __func__, baud);
 270
 271
 272         divisor = MAX_BAUD_RATE / baud;
 273         remainder = MAX_BAUD_RATE % baud;
 274         if (((remainder * 2) >= baud) && (baud != 110))
 275                 divisor++;
 276
 277         urb_value = urb_value << 8;
 278
 279         result = ssu100_control_msg(dev, QT_GET_SET_UART, divisor, urb_value);
 280         if (result < 0)
 281                 dbg("%s - set uart failed", __func__);
 282
 283         if (cflag & CRTSCTS)
 284                 result = ssu100_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
 285                                             SERIAL_CRTSCTS, 0);
 286         else
 287                 result = ssu100_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
 288                                             0, 0);
 289         if (result < 0)
 290                 dbg("%s - set HW flow control failed", __func__);
 291
 292         if (I_IXOFF(tty) || I_IXON(tty)) {
 293                 u16 x = ((u16)(START_CHAR(tty) << 8) | (u16)(STOP_CHAR(tty)));
 294
 295                 result = ssu100_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
 296                                             x, 0);
 297         } else
 298                 result = ssu100_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
 299                                             0, 0);
 300
 301         if (result < 0)
 302                 dbg("%s - set SW flow control failed", __func__);
 303
 304 }
 305
 306
 307 static int ssu100_open(struct tty_struct *tty, struct usb_serial_port *port)
 308 {
 309         struct usb_device *dev = port->serial->dev;
 310         struct ssu100_port_private *priv = usb_get_serial_port_data(port);
 311         u8 *data;
 312         int result;
 313         unsigned long flags;
 314
 315         dbg("%s - port %d", __func__, port->number);
 316
 317         data = kzalloc(2, GFP_KERNEL);
 318         if (!data)
 319                 return -ENOMEM;
 320
 321         result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 322                                  QT_OPEN_CLOSE_CHANNEL,
 323                                  QT_TRANSFER_IN, 0x01,
 324                                  0, data, 2, 300);
 325         if (result < 0) {
 326                 dbg("%s - open failed %i", __func__, result);
 327                 kfree(data);
 328                 return result;
 329         }
 330
 331         spin_lock_irqsave(&priv->status_lock, flags);
 332         priv->shadowLSR = data[0]  & (UART_LSR_OE | UART_LSR_PE |
 333                                       UART_LSR_FE | UART_LSR_BI);
 334
 335         priv->shadowMSR = data[1]  & (UART_MSR_CTS | UART_MSR_DSR |
 336                                       UART_MSR_RI | UART_MSR_DCD);
 337         spin_unlock_irqrestore(&priv->status_lock, flags);
 338
 339         kfree(data);
 340
 341 /* set to 9600 */
 342         result = ssu100_control_msg(dev, QT_GET_SET_UART, 0x30, 0x0300);
 343         if (result < 0)
 344                 dbg("%s - set uart failed", __func__);
 345
 346         if (tty)
 347                 ssu100_set_termios(tty, port, tty->termios);
 348
 349         return usb_serial_generic_open(tty, port);
 350 }
 351
 352 static void ssu100_close(struct usb_serial_port *port)
 353 {
 354         dbg("%s", __func__);
 355         usb_serial_generic_close(port);
 356 }
 357
 358 static int get_serial_info(struct usb_serial_port *port,
 359                            struct serial_struct __user *retinfo)
 360 {
 361         struct serial_struct tmp;
 362
 363         if (!retinfo)
 364                 return -EFAULT;
 365
 366         memset(&tmp, 0, sizeof(tmp));
 367         tmp.line                = port->serial->minor;
 368         tmp.port                = 0;
 369         tmp.irq                 = 0;
 370         tmp.flags               = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
 371         tmp.xmit_fifo_size      = port->bulk_out_size;
 372         tmp.baud_base           = 9600;
 373         tmp.close_delay         = 5*HZ;
 374         tmp.closing_wait        = 30*HZ;
 375
 376         if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
 377                 return -EFAULT;
 378         return 0;
 379 }
 380
 381 static int ssu100_ioctl(struct tty_struct *tty, struct file *file,
 382                     unsigned int cmd, unsigned long arg)
 383 {
 384         struct usb_serial_port *port = tty->driver_data;
 385         struct ssu100_port_private *priv = usb_get_serial_port_data(port);
 386
 387         dbg("%s cmd 0x%04x", __func__, cmd);
 388
 389         switch (cmd) {
 390         case TIOCGSERIAL:
 391                 return get_serial_info(port,
 392                                        (struct serial_struct __user *) arg);
 393
 394         case TIOCMIWAIT:
 395                 while (priv != NULL) {
 396                         u8 prevMSR = priv->shadowMSR & SERIAL_MSR_MASK;
 397                         interruptible_sleep_on(&priv->delta_msr_wait);
 398                         /* see if a signal did it */
 399                         if (signal_pending(current))
 400                                 return -ERESTARTSYS;
 401                         else {
 402                                 u8 diff = (priv->shadowMSR & SERIAL_MSR_MASK) ^ prevMSR;
 403                                 if (!diff)
 404                                         return -EIO; /* no change => error */
 405
 406                                 /* Return 0 if caller wanted to know about
 407                                    these bits */
 408
 409                                 if (((arg & TIOCM_RNG) && (diff & UART_MSR_RI)) ||
 410                                     ((arg & TIOCM_DSR) && (diff & UART_MSR_DSR)) ||
 411                                     ((arg & TIOCM_CD) && (diff & UART_MSR_DCD)) ||
 412                                     ((arg & TIOCM_CTS) && (diff & UART_MSR_CTS)))
 413                                         return 0;
 414                         }
 415                 }
 416                 return 0;
 417
 418         default:
 419                 break;
 420         }
 421
 422         dbg("%s arg not supported", __func__);
 423
 424         return -ENOIOCTLCMD;
 425 }
 426
 427 static void ssu100_set_max_packet_size(struct usb_serial_port *port)
 428 {
 429         struct ssu100_port_private *priv = usb_get_serial_port_data(port);
 430         struct usb_serial *serial = port->serial;
 431         struct usb_device *udev = serial->dev;
 432
 433         struct usb_interface *interface = serial->interface;
 434         struct usb_endpoint_descriptor *ep_desc = &interface->cur_altsetting->endpoint[1].desc;
 435
 436         unsigned num_endpoints;
 437         int i;
 438         unsigned long flags;
 439
 440         num_endpoints = interface->cur_altsetting->desc.bNumEndpoints;
 441         dev_info(&udev->dev, "Number of endpoints %d\n", num_endpoints);
 442
 443         for (i = 0; i < num_endpoints; i++) {
 444                 dev_info(&udev->dev, "Endpoint %d MaxPacketSize %d\n", i+1,
 445                         interface->cur_altsetting->endpoint[i].desc.wMaxPacketSize);
 446                 ep_desc = &interface->cur_altsetting->endpoint[i].desc;
 447         }
 448
 449         /* set max packet size based on descriptor */
 450         spin_lock_irqsave(&priv->status_lock, flags);
 451         priv->max_packet_size = ep_desc->wMaxPacketSize;
 452         spin_unlock_irqrestore(&priv->status_lock, flags);
 453
 454         dev_info(&udev->dev, "Setting MaxPacketSize %d\n", priv->max_packet_size);
 455 }
 456
 457 static int ssu100_attach(struct usb_serial *serial)
 458 {
 459         struct ssu100_port_private *priv;
 460         struct usb_serial_port *port = *serial->port;
 461
 462         dbg("%s", __func__);
 463
 464         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 465         if (!priv) {
 466                 dev_err(&port->dev, "%s- kmalloc(%Zd) failed.\n", __func__,
 467                         sizeof(*priv));
 468                 return -ENOMEM;
 469         }
 470
 471         spin_lock_init(&priv->status_lock);
 472         init_waitqueue_head(&priv->delta_msr_wait);
 473         usb_set_serial_port_data(port, priv);
 474         ssu100_set_max_packet_size(port);
 475
 476         return ssu100_initdevice(serial->dev);
 477 }
 478
 479 static int ssu100_tiocmget(struct tty_struct *tty, struct file *file)
 480 {
 481         struct usb_serial_port *port = tty->driver_data;
 482         struct usb_device *dev = port->serial->dev;
 483         u8 *d;
 484         int r;
 485
 486         dbg("%s\n", __func__);
 487
 488         d = kzalloc(2, GFP_KERNEL);
 489         if (!d)
 490                 return -ENOMEM;
 491
 492         r = ssu100_getregister(dev, 0, UART_MCR, d);
 493         if (r < 0)
 494                 goto mget_out;
 495
 496         r = ssu100_getregister(dev, 0, UART_MSR, d+1);
 497         if (r < 0)
 498                 goto mget_out;
 499
 500         r = (d[0] & UART_MCR_DTR ? TIOCM_DTR : 0) |
 501                 (d[0] & UART_MCR_RTS ? TIOCM_RTS : 0) |
 502                 (d[1] & UART_MSR_CTS ? TIOCM_CTS : 0) |
 503                 (d[1] & UART_MSR_DCD ? TIOCM_CAR : 0) |
 504                 (d[1] & UART_MSR_RI ? TIOCM_RI : 0) |
 505                 (d[1] & UART_MSR_DSR ? TIOCM_DSR : 0);
 506
 507 mget_out:
 508         kfree(d);
 509         return r;
 510 }
 511
 512 static int ssu100_tiocmset(struct tty_struct *tty, struct file *file,
 513                            unsigned int set, unsigned int clear)
 514 {
 515         struct usb_serial_port *port = tty->driver_data;
 516         struct usb_device *dev = port->serial->dev;
 517
 518         dbg("%s\n", __func__);
 519         return update_mctrl(dev, set, clear);
 520 }
 521
 522 static void ssu100_dtr_rts(struct usb_serial_port *port, int on)
 523 {
 524         struct usb_device *dev = port->serial->dev;
 525
 526         dbg("%s\n", __func__);
 527
 528         mutex_lock(&port->serial->disc_mutex);
 529         if (!port->serial->disconnected) {
 530                 /* Disable flow control */
 531                 if (!on &&
 532                     ssu100_setregister(dev, 0, 0) < 0)
 533                         dev_err(&port->dev, "error from flowcontrol urb\n");
 534                 /* drop RTS and DTR */
 535                 if (on)
 536                         set_mctrl(dev, TIOCM_DTR | TIOCM_RTS);
 537                 else
 538                         clear_mctrl(dev, TIOCM_DTR | TIOCM_RTS);
 539         }
 540         mutex_unlock(&port->serial->disc_mutex);
 541 }
 542
 543 static int ssu100_process_packet(struct tty_struct *tty,
 544                                  struct usb_serial_port *port,
 545                                  struct ssu100_port_private *priv,
 546                                  char *packet, int len)
 547 {
 548         int i;
 549         char flag;
 550         char *ch;
 551
 552         dbg("%s - port %d", __func__, port->number);
 553
 554         if ((len >= 4) &&
 555             (packet[0] == 0x1b) && (packet[1] == 0x1b) &&
 556             ((packet[2] == 0x00) || (packet[2] == 0x01))) {
 557                 if (packet[2] == 0x00)
 558                         priv->shadowLSR = packet[3] & (UART_LSR_OE |
 559                                                        UART_LSR_PE |
 560                                                        UART_LSR_FE |
 561                                                        UART_LSR_BI);
 562
 563                 if (packet[2] == 0x01) {
 564                         priv->shadowMSR = packet[3];
 565                         wake_up_interruptible(&priv->delta_msr_wait);
 566                 }
 567
 568                 len -= 4;
 569                 ch = packet + 4;
 570         } else
 571                 ch = packet;
 572
 573         if (!len)
 574                 return 0;       /* status only */
 575
 576         if (port->port.console && port->sysrq) {
 577                 for (i = 0; i < len; i++, ch++) {
 578                         if (!usb_serial_handle_sysrq_char(tty, port, *ch))
 579                                 tty_insert_flip_char(tty, *ch, flag);
 580                 }
 581         } else
 582                 tty_insert_flip_string_fixed_flag(tty, ch, flag, len);
 583
 584         return len;
 585 }
 586
 587 static void ssu100_process_read_urb(struct urb *urb)
 588 {
 589         struct usb_serial_port *port = urb->context;
 590         struct ssu100_port_private *priv = usb_get_serial_port_data(port);
 591         char *data = (char *)urb->transfer_buffer;
 592         struct tty_struct *tty;
 593         int count = 0;
 594         int i;
 595         int len;
 596
 597         dbg("%s", __func__);
 598
 599         tty = tty_port_tty_get(&port->port);
 600         if (!tty)
 601                 return;
 602
 603         for (i = 0; i < urb->actual_length; i += priv->max_packet_size) {
 604                 len = min_t(int, urb->actual_length - i, priv->max_packet_size);
 605                 count += ssu100_process_packet(tty, port, priv, &data[i], len);
 606         }
 607
 608         if (count)
 609                 tty_flip_buffer_push(tty);
 610         tty_kref_put(tty);
 611 }
 612
 613
 614 static struct usb_serial_driver ssu100_device = {
 615         .driver = {
 616                 .owner = THIS_MODULE,
 617                 .name = "ssu100",
 618         },
 619         .description         = DRIVER_DESC,
 620         .id_table            = id_table,
 621         .usb_driver          = &ssu100_driver,
 622         .num_ports           = 1,
 623         .bulk_in_size        = 256,
 624         .bulk_out_size       = 256,
 625         .open                = ssu100_open,
 626         .close               = ssu100_close,
 627         .attach              = ssu100_attach,
 628         .release             = ssu100_release,
 629         .dtr_rts             = ssu100_dtr_rts,
 630         .process_read_urb    = ssu100_process_read_urb,
 631         .tiocmget            = ssu100_tiocmget,
 632         .tiocmset            = ssu100_tiocmset,
 633         .ioctl               = ssu100_ioctl,
 634         .set_termios         = ssu100_set_termios,
 635 };
 636
 637 static int __init ssu100_init(void)
 638 {
 639         int retval;
 640
 641         dbg("%s", __func__);
 642
 643         /* register with usb-serial */
 644         retval = usb_serial_register(&ssu100_device);
 645
 646         if (retval)
 647                 goto failed_usb_sio_register;
 648
 649         retval = usb_register(&ssu100_driver);
 650         if (retval)
 651                 goto failed_usb_register;
 652
 653         printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
 654                DRIVER_DESC "\n");
 655
 656         return 0;
 657
 658 failed_usb_register:
 659         usb_serial_deregister(&ssu100_device);
 660 failed_usb_sio_register:
 661         return retval;
 662 }
 663
 664 static void __exit ssu100_exit(void)
 665 {
 666         usb_deregister(&ssu100_driver);
 667         usb_serial_deregister(&ssu100_device);
 668 }
 669
 670 module_init(ssu100_init);
 671 module_exit(ssu100_exit);
 672
 673 MODULE_DESCRIPTION(DRIVER_DESC);
 674 MODULE_LICENSE("GPL");
 675
 676 module_param(debug, bool, S_IRUGO | S_IWUSR);
 677 MODULE_PARM_DESC(debug, "Debug enabled or not");