drivers/usb/serial/kl5kusb105.c

   1 /*
   2  * KLSI KL5KUSB105 chip RS232 converter driver
   3  *
   4  *   Copyright (C) 2010 Johan Hovold <jhovold@gmail.com>
   5  *   Copyright (C) 2001 Utz-Uwe Haus <haus@uuhaus.de>
   6  *
   7  *   This program is free software; you can redistribute it and/or modify
   8  *   it under the terms of the GNU General Public License as published by
   9  *   the Free Software Foundation; either version 2 of the License, or
  10  *   (at your option) any later version.
  11  *
  12  * All information about the device was acquired using SniffUSB ans snoopUSB
  13  * on Windows98.
  14  * It was written out of frustration with the PalmConnect USB Serial adapter
  15  * sold by Palm Inc.
  16  * Neither Palm, nor their contractor (MCCI) or their supplier (KLSI) provided
  17  * information that was not already available.
  18  *
  19  * It seems that KLSI bought some silicon-design information from ScanLogic,
  20  * whose SL11R processor is at the core of the KL5KUSB chipset from KLSI.
  21  * KLSI has firmware available for their devices; it is probable that the
  22  * firmware differs from that used by KLSI in their products. If you have an
  23  * original KLSI device and can provide some information on it, I would be
  24  * most interested in adding support for it here. If you have any information
  25  * on the protocol used (or find errors in my reverse-engineered stuff), please
  26  * let me know.
  27  *
  28  * The code was only tested with a PalmConnect USB adapter; if you
  29  * are adventurous, try it with any KLSI-based device and let me know how it
  30  * breaks so that I can fix it!
  31  */
  32
  33 /* TODO:
  34  *      check modem line signals
  35  *      implement handshaking or decide that we do not support it
  36  */
  37
  38 #include <linux/kernel.h>
  39 #include <linux/errno.h>
  40 #include <linux/slab.h>
  41 #include <linux/tty.h>
  42 #include <linux/tty_driver.h>
  43 #include <linux/tty_flip.h>
  44 #include <linux/module.h>
  45 #include <linux/uaccess.h>
  46 #include <asm/unaligned.h>
  47 #include <linux/usb.h>
  48 #include <linux/usb/serial.h>
  49 #include "kl5kusb105.h"
  50
  51 #define DRIVER_AUTHOR "Utz-Uwe Haus <haus@uuhaus.de>, Johan Hovold <jhovold@gmail.com>"
  52 #define DRIVER_DESC "KLSI KL5KUSB105 chipset USB->Serial Converter driver"
  53
  54
  55 /*
  56  * Function prototypes
  57  */
  58 static int klsi_105_port_probe(struct usb_serial_port *port);
  59 static int klsi_105_port_remove(struct usb_serial_port *port);
  60 static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port);
  61 static void klsi_105_close(struct usb_serial_port *port);
  62 static void klsi_105_set_termios(struct tty_struct *tty,
  63                         struct usb_serial_port *port, struct ktermios *old);
  64 static int  klsi_105_tiocmget(struct tty_struct *tty);
  65 static void klsi_105_process_read_urb(struct urb *urb);
  66 static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
  67                                                 void *dest, size_t size);
  68
  69 /*
  70  * All of the device info needed for the KLSI converters.
  71  */
  72 static const struct usb_device_id id_table[] = {
  73         { USB_DEVICE(PALMCONNECT_VID, PALMCONNECT_PID) },
  74         { USB_DEVICE(KLSI_VID, KLSI_KL5KUSB105D_PID) },
  75         { }             /* Terminating entry */
  76 };
  77
  78 MODULE_DEVICE_TABLE(usb, id_table);
  79
  80 static struct usb_serial_driver kl5kusb105d_device = {
  81         .driver = {
  82                 .owner =        THIS_MODULE,
  83                 .name =         "kl5kusb105d",
  84         },
  85         .description =          "KL5KUSB105D / PalmConnect",
  86         .id_table =             id_table,
  87         .num_ports =            1,
  88         .bulk_out_size =        64,
  89         .open =                 klsi_105_open,
  90         .close =                klsi_105_close,
  91         .set_termios =          klsi_105_set_termios,
  92         /*.break_ctl =          klsi_105_break_ctl,*/
  93         .tiocmget =             klsi_105_tiocmget,
  94         .port_probe =           klsi_105_port_probe,
  95         .port_remove =          klsi_105_port_remove,
  96         .throttle =             usb_serial_generic_throttle,
  97         .unthrottle =           usb_serial_generic_unthrottle,
  98         .process_read_urb =     klsi_105_process_read_urb,
  99         .prepare_write_buffer = klsi_105_prepare_write_buffer,
 100 };
 101
 102 static struct usb_serial_driver * const serial_drivers[] = {
 103         &kl5kusb105d_device, NULL
 104 };
 105
 106 struct klsi_105_port_settings {
 107         __u8    pktlen;         /* always 5, it seems */
 108         __u8    baudrate;
 109         __u8    databits;
 110         __u8    unknown1;
 111         __u8    unknown2;
 112 } __attribute__ ((packed));
 113
 114 struct klsi_105_private {
 115         struct klsi_105_port_settings   cfg;
 116         struct ktermios                 termios;
 117         unsigned long                   line_state; /* modem line settings */
 118         spinlock_t                      lock;
 119 };
 120
 121
 122 /*
 123  * Handle vendor specific USB requests
 124  */
 125
 126
 127 #define KLSI_TIMEOUT     5000 /* default urb timeout */
 128
 129 static int klsi_105_chg_port_settings(struct usb_serial_port *port,
 130                                       struct klsi_105_port_settings *settings)
 131 {
 132         int rc;
 133
 134         rc = usb_control_msg(port->serial->dev,
 135                         usb_sndctrlpipe(port->serial->dev, 0),
 136                         KL5KUSB105A_SIO_SET_DATA,
 137                         USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_INTERFACE,
 138                         0, /* value */
 139                         0, /* index */
 140                         settings,
 141                         sizeof(struct klsi_105_port_settings),
 142                         KLSI_TIMEOUT);
 143         if (rc < 0)
 144                 dev_err(&port->dev,
 145                         "Change port settings failed (error = %d)\n", rc);
 146         dev_info(&port->serial->dev->dev,
 147                  "%d byte block, baudrate %x, databits %d, u1 %d, u2 %d\n",
 148                  settings->pktlen, settings->baudrate, settings->databits,
 149                  settings->unknown1, settings->unknown2);
 150         return rc;
 151 }
 152
 153 /* translate a 16-bit status value from the device to linux's TIO bits */
 154 static unsigned long klsi_105_status2linestate(const __u16 status)
 155 {
 156         unsigned long res = 0;
 157
 158         res =   ((status & KL5KUSB105A_DSR) ? TIOCM_DSR : 0)
 159               | ((status & KL5KUSB105A_CTS) ? TIOCM_CTS : 0)
 160               ;
 161
 162         return res;
 163 }
 164
 165 /*
 166  * Read line control via vendor command and return result through
 167  * *line_state_p
 168  */
 169 /* It seems that the status buffer has always only 2 bytes length */
 170 #define KLSI_STATUSBUF_LEN      2
 171 static int klsi_105_get_line_state(struct usb_serial_port *port,
 172                                    unsigned long *line_state_p)
 173 {
 174         int rc;
 175         u8 *status_buf;
 176         __u16 status;
 177
 178         dev_info(&port->serial->dev->dev, "sending SIO Poll request\n");
 179
 180         status_buf = kmalloc(KLSI_STATUSBUF_LEN, GFP_KERNEL);
 181         if (!status_buf)
 182                 return -ENOMEM;
 183
 184         status_buf[0] = 0xff;
 185         status_buf[1] = 0xff;
 186         rc = usb_control_msg(port->serial->dev,
 187                              usb_rcvctrlpipe(port->serial->dev, 0),
 188                              KL5KUSB105A_SIO_POLL,
 189                              USB_TYPE_VENDOR | USB_DIR_IN,
 190                              0, /* value */
 191                              0, /* index */
 192                              status_buf, KLSI_STATUSBUF_LEN,
 193                              10000
 194                              );
 195         if (rc != KLSI_STATUSBUF_LEN) {
 196                 dev_err(&port->dev, "reading line status failed: %d\n", rc);
 197                 if (rc >= 0)
 198                         rc = -EIO;
 199         } else {
 200                 status = get_unaligned_le16(status_buf);
 201
 202                 dev_info(&port->serial->dev->dev, "read status %x %x\n",
 203                          status_buf[0], status_buf[1]);
 204
 205                 *line_state_p = klsi_105_status2linestate(status);
 206         }
 207
 208         kfree(status_buf);
 209         return rc;
 210 }
 211
 212
 213 /*
 214  * Driver's tty interface functions
 215  */
 216
 217 static int klsi_105_port_probe(struct usb_serial_port *port)
 218 {
 219         struct klsi_105_private *priv;
 220
 221         priv = kmalloc(sizeof(*priv), GFP_KERNEL);
 222         if (!priv)
 223                 return -ENOMEM;
 224
 225         /* set initial values for control structures */
 226         priv->cfg.pktlen    = 5;
 227         priv->cfg.baudrate  = kl5kusb105a_sio_b9600;
 228         priv->cfg.databits  = kl5kusb105a_dtb_8;
 229         priv->cfg.unknown1  = 0;
 230         priv->cfg.unknown2  = 1;
 231
 232         priv->line_state    = 0;
 233
 234         spin_lock_init(&priv->lock);
 235
 236         /* priv->termios is left uninitialized until port opening */
 237
 238         usb_set_serial_port_data(port, priv);
 239
 240         return 0;
 241 }
 242
 243 static int klsi_105_port_remove(struct usb_serial_port *port)
 244 {
 245         struct klsi_105_private *priv;
 246
 247         priv = usb_get_serial_port_data(port);
 248         kfree(priv);
 249
 250         return 0;
 251 }
 252
 253 static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port)
 254 {
 255         struct klsi_105_private *priv = usb_get_serial_port_data(port);
 256         int retval = 0;
 257         int rc;
 258         int i;
 259         unsigned long line_state;
 260         struct klsi_105_port_settings *cfg;
 261         unsigned long flags;
 262
 263         /* Do a defined restart:
 264          * Set up sane default baud rate and send the 'READ_ON'
 265          * vendor command.
 266          * FIXME: set modem line control (how?)
 267          * Then read the modem line control and store values in
 268          * priv->line_state.
 269          */
 270         cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
 271         if (!cfg)
 272                 return -ENOMEM;
 273
 274         cfg->pktlen   = 5;
 275         cfg->baudrate = kl5kusb105a_sio_b9600;
 276         cfg->databits = kl5kusb105a_dtb_8;
 277         cfg->unknown1 = 0;
 278         cfg->unknown2 = 1;
 279         klsi_105_chg_port_settings(port, cfg);
 280
 281         /* set up termios structure */
 282         spin_lock_irqsave(&priv->lock, flags);
 283         priv->termios.c_iflag = tty->termios.c_iflag;
 284         priv->termios.c_oflag = tty->termios.c_oflag;
 285         priv->termios.c_cflag = tty->termios.c_cflag;
 286         priv->termios.c_lflag = tty->termios.c_lflag;
 287         for (i = 0; i < NCCS; i++)
 288                 priv->termios.c_cc[i] = tty->termios.c_cc[i];
 289         priv->cfg.pktlen   = cfg->pktlen;
 290         priv->cfg.baudrate = cfg->baudrate;
 291         priv->cfg.databits = cfg->databits;
 292         priv->cfg.unknown1 = cfg->unknown1;
 293         priv->cfg.unknown2 = cfg->unknown2;
 294         spin_unlock_irqrestore(&priv->lock, flags);
 295
 296         kfree(cfg);
 297
 298         /* READ_ON and urb submission */
 299         rc = usb_serial_generic_open(tty, port);
 300         if (rc)
 301                 return rc;
 302
 303         rc = usb_control_msg(port->serial->dev,
 304                              usb_sndctrlpipe(port->serial->dev, 0),
 305                              KL5KUSB105A_SIO_CONFIGURE,
 306                              USB_TYPE_VENDOR|USB_DIR_OUT|USB_RECIP_INTERFACE,
 307                              KL5KUSB105A_SIO_CONFIGURE_READ_ON,
 308                              0, /* index */
 309                              NULL,
 310                              0,
 311                              KLSI_TIMEOUT);
 312         if (rc < 0) {
 313                 dev_err(&port->dev, "Enabling read failed (error = %d)\n", rc);
 314                 retval = rc;
 315                 goto err_generic_close;
 316         } else
 317                 dev_dbg(&port->dev, "%s - enabled reading\n", __func__);
 318
 319         rc = klsi_105_get_line_state(port, &line_state);
 320         if (rc < 0) {
 321                 retval = rc;
 322                 goto err_disable_read;
 323         }
 324
 325         spin_lock_irqsave(&priv->lock, flags);
 326         priv->line_state = line_state;
 327         spin_unlock_irqrestore(&priv->lock, flags);
 328         dev_dbg(&port->dev, "%s - read line state 0x%lx\n", __func__,
 329                         line_state);
 330
 331         return 0;
 332
 333 err_disable_read:
 334         usb_control_msg(port->serial->dev,
 335                              usb_sndctrlpipe(port->serial->dev, 0),
 336                              KL5KUSB105A_SIO_CONFIGURE,
 337                              USB_TYPE_VENDOR | USB_DIR_OUT,
 338                              KL5KUSB105A_SIO_CONFIGURE_READ_OFF,
 339                              0, /* index */
 340                              NULL, 0,
 341                              KLSI_TIMEOUT);
 342 err_generic_close:
 343         usb_serial_generic_close(port);
 344
 345         return retval;
 346 }
 347
 348 static void klsi_105_close(struct usb_serial_port *port)
 349 {
 350         int rc;
 351
 352         /* send READ_OFF */
 353         rc = usb_control_msg(port->serial->dev,
 354                              usb_sndctrlpipe(port->serial->dev, 0),
 355                              KL5KUSB105A_SIO_CONFIGURE,
 356                              USB_TYPE_VENDOR | USB_DIR_OUT,
 357                              KL5KUSB105A_SIO_CONFIGURE_READ_OFF,
 358                              0, /* index */
 359                              NULL, 0,
 360                              KLSI_TIMEOUT);
 361         if (rc < 0)
 362                 dev_err(&port->dev, "failed to disable read: %d\n", rc);
 363
 364         /* shutdown our bulk reads and writes */
 365         usb_serial_generic_close(port);
 366 }
 367
 368 /* We need to write a complete 64-byte data block and encode the
 369  * number actually sent in the first double-byte, LSB-order. That
 370  * leaves at most 62 bytes of payload.
 371  */
 372 #define KLSI_HDR_LEN            2
 373 static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
 374                                                 void *dest, size_t size)
 375 {
 376         unsigned char *buf = dest;
 377         int count;
 378
 379         count = kfifo_out_locked(&port->write_fifo, buf + KLSI_HDR_LEN, size,
 380                                                                 &port->lock);
 381         put_unaligned_le16(count, buf);
 382
 383         return count + KLSI_HDR_LEN;
 384 }
 385
 386 /* The data received is preceded by a length double-byte in LSB-first order.
 387  */
 388 static void klsi_105_process_read_urb(struct urb *urb)
 389 {
 390         struct usb_serial_port *port = urb->context;
 391         unsigned char *data = urb->transfer_buffer;
 392         unsigned len;
 393
 394         /* empty urbs seem to happen, we ignore them */
 395         if (!urb->actual_length)
 396                 return;
 397
 398         if (urb->actual_length <= KLSI_HDR_LEN) {
 399                 dev_dbg(&port->dev, "%s - malformed packet\n", __func__);
 400                 return;
 401         }
 402
 403         len = get_unaligned_le16(data);
 404         if (len > urb->actual_length - KLSI_HDR_LEN) {
 405                 dev_dbg(&port->dev, "%s - packet length mismatch\n", __func__);
 406                 len = urb->actual_length - KLSI_HDR_LEN;
 407         }
 408
 409         tty_insert_flip_string(&port->port, data + KLSI_HDR_LEN, len);
 410         tty_flip_buffer_push(&port->port);
 411 }
 412
 413 static void klsi_105_set_termios(struct tty_struct *tty,
 414                                  struct usb_serial_port *port,
 415                                  struct ktermios *old_termios)
 416 {
 417         struct klsi_105_private *priv = usb_get_serial_port_data(port);
 418         struct device *dev = &port->dev;
 419         unsigned int iflag = tty->termios.c_iflag;
 420         unsigned int old_iflag = old_termios->c_iflag;
 421         unsigned int cflag = tty->termios.c_cflag;
 422         unsigned int old_cflag = old_termios->c_cflag;
 423         struct klsi_105_port_settings *cfg;
 424         unsigned long flags;
 425         speed_t baud;
 426
 427         cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
 428         if (!cfg)
 429                 return;
 430
 431         /* lock while we are modifying the settings */
 432         spin_lock_irqsave(&priv->lock, flags);
 433
 434         /*
 435          * Update baud rate
 436          */
 437         baud = tty_get_baud_rate(tty);
 438
 439         if ((cflag & CBAUD) != (old_cflag & CBAUD)) {
 440                 /* reassert DTR and (maybe) RTS on transition from B0 */
 441                 if ((old_cflag & CBAUD) == B0) {
 442                         dev_dbg(dev, "%s: baud was B0\n", __func__);
 443 #if 0
 444                         priv->control_state |= TIOCM_DTR;
 445                         /* don't set RTS if using hardware flow control */
 446                         if (!(old_cflag & CRTSCTS))
 447                                 priv->control_state |= TIOCM_RTS;
 448                         mct_u232_set_modem_ctrl(serial, priv->control_state);
 449 #endif
 450                 }
 451         }
 452         switch (baud) {
 453         case 0: /* handled below */
 454                 break;
 455         case 1200:
 456                 priv->cfg.baudrate = kl5kusb105a_sio_b1200;
 457                 break;
 458         case 2400:
 459                 priv->cfg.baudrate = kl5kusb105a_sio_b2400;
 460                 break;
 461         case 4800:
 462                 priv->cfg.baudrate = kl5kusb105a_sio_b4800;
 463                 break;
 464         case 9600:
 465                 priv->cfg.baudrate = kl5kusb105a_sio_b9600;
 466                 break;
 467         case 19200:
 468                 priv->cfg.baudrate = kl5kusb105a_sio_b19200;
 469                 break;
 470         case 38400:
 471                 priv->cfg.baudrate = kl5kusb105a_sio_b38400;
 472                 break;
 473         case 57600:
 474                 priv->cfg.baudrate = kl5kusb105a_sio_b57600;
 475                 break;
 476         case 115200:
 477                 priv->cfg.baudrate = kl5kusb105a_sio_b115200;
 478                 break;
 479         default:
 480                 dev_dbg(dev, "unsupported baudrate, using 9600\n");
 481                 priv->cfg.baudrate = kl5kusb105a_sio_b9600;
 482                 baud = 9600;
 483                 break;
 484         }
 485         if ((cflag & CBAUD) == B0) {
 486                 dev_dbg(dev, "%s: baud is B0\n", __func__);
 487                 /* Drop RTS and DTR */
 488                 /* maybe this should be simulated by sending read
 489                  * disable and read enable messages?
 490                  */
 491 #if 0
 492                 priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
 493                 mct_u232_set_modem_ctrl(serial, priv->control_state);
 494 #endif
 495         }
 496         tty_encode_baud_rate(tty, baud, baud);
 497
 498         if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
 499                 /* set the number of data bits */
 500                 switch (cflag & CSIZE) {
 501                 case CS5:
 502                         dev_dbg(dev, "%s - 5 bits/byte not supported\n", __func__);
 503                         spin_unlock_irqrestore(&priv->lock, flags);
 504                         goto err;
 505                 case CS6:
 506                         dev_dbg(dev, "%s - 6 bits/byte not supported\n", __func__);
 507                         spin_unlock_irqrestore(&priv->lock, flags);
 508                         goto err;
 509                 case CS7:
 510                         priv->cfg.databits = kl5kusb105a_dtb_7;
 511                         break;
 512                 case CS8:
 513                         priv->cfg.databits = kl5kusb105a_dtb_8;
 514                         break;
 515                 default:
 516                         dev_err(dev, "CSIZE was not CS5-CS8, using default of 8\n");
 517                         priv->cfg.databits = kl5kusb105a_dtb_8;
 518                         break;
 519                 }
 520         }
 521
 522         /*
 523          * Update line control register (LCR)
 524          */
 525         if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))
 526             || (cflag & CSTOPB) != (old_cflag & CSTOPB)) {
 527                 /* Not currently supported */
 528                 tty->termios.c_cflag &= ~(PARENB|PARODD|CSTOPB);
 529 #if 0
 530                 priv->last_lcr = 0;
 531
 532                 /* set the parity */
 533                 if (cflag & PARENB)
 534                         priv->last_lcr |= (cflag & PARODD) ?
 535                                 MCT_U232_PARITY_ODD : MCT_U232_PARITY_EVEN;
 536                 else
 537                         priv->last_lcr |= MCT_U232_PARITY_NONE;
 538
 539                 /* set the number of stop bits */
 540                 priv->last_lcr |= (cflag & CSTOPB) ?
 541                         MCT_U232_STOP_BITS_2 : MCT_U232_STOP_BITS_1;
 542
 543                 mct_u232_set_line_ctrl(serial, priv->last_lcr);
 544 #endif
 545         }
 546         /*
 547          * Set flow control: well, I do not really now how to handle DTR/RTS.
 548          * Just do what we have seen with SniffUSB on Win98.
 549          */
 550         if ((iflag & IXOFF) != (old_iflag & IXOFF)
 551             || (iflag & IXON) != (old_iflag & IXON)
 552             ||  (cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
 553                 /* Not currently supported */
 554                 tty->termios.c_cflag &= ~CRTSCTS;
 555                 /* Drop DTR/RTS if no flow control otherwise assert */
 556 #if 0
 557                 if ((iflag & IXOFF) || (iflag & IXON) || (cflag & CRTSCTS))
 558                         priv->control_state |= TIOCM_DTR | TIOCM_RTS;
 559                 else
 560                         priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
 561                 mct_u232_set_modem_ctrl(serial, priv->control_state);
 562 #endif
 563         }
 564         memcpy(cfg, &priv->cfg, sizeof(*cfg));
 565         spin_unlock_irqrestore(&priv->lock, flags);
 566
 567         /* now commit changes to device */
 568         klsi_105_chg_port_settings(port, cfg);
 569 err:
 570         kfree(cfg);
 571 }
 572
 573 #if 0
 574 static void mct_u232_break_ctl(struct tty_struct *tty, int break_state)
 575 {
 576         struct usb_serial_port *port = tty->driver_data;
 577         struct usb_serial *serial = port->serial;
 578         struct mct_u232_private *priv =
 579                                 (struct mct_u232_private *)port->private;
 580         unsigned char lcr = priv->last_lcr;
 581
 582         dev_dbg(&port->dev, "%s - state=%d\n", __func__, break_state);
 583
 584         /* LOCKING */
 585         if (break_state)
 586                 lcr |= MCT_U232_SET_BREAK;
 587
 588         mct_u232_set_line_ctrl(serial, lcr);
 589 }
 590 #endif
 591
 592 static int klsi_105_tiocmget(struct tty_struct *tty)
 593 {
 594         struct usb_serial_port *port = tty->driver_data;
 595         struct klsi_105_private *priv = usb_get_serial_port_data(port);
 596         unsigned long flags;
 597         int rc;
 598         unsigned long line_state;
 599
 600         rc = klsi_105_get_line_state(port, &line_state);
 601         if (rc < 0) {
 602                 dev_err(&port->dev,
 603                         "Reading line control failed (error = %d)\n", rc);
 604                 /* better return value? EAGAIN? */
 605                 return rc;
 606         }
 607
 608         spin_lock_irqsave(&priv->lock, flags);
 609         priv->line_state = line_state;
 610         spin_unlock_irqrestore(&priv->lock, flags);
 611         dev_dbg(&port->dev, "%s - read line state 0x%lx\n", __func__, line_state);
 612         return (int)line_state;
 613 }
 614
 615 module_usb_serial_driver(serial_drivers, id_table);
 616
 617 MODULE_AUTHOR(DRIVER_AUTHOR);
 618 MODULE_DESCRIPTION(DRIVER_DESC);
 619 MODULE_LICENSE("GPL");