Pileus Git - ~andy/linux/blob - 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/init.h>
  41 #include <linux/slab.h>
  42 #include <linux/tty.h>
  43 #include <linux/tty_driver.h>
  44 #include <linux/tty_flip.h>
  45 #include <linux/module.h>
  46 #include <linux/uaccess.h>
  47 #include <asm/unaligned.h>
  48 #include <linux/usb.h>
  49 #include <linux/usb/serial.h>
  50 #include "kl5kusb105.h"
  51
  52 #define DRIVER_AUTHOR "Utz-Uwe Haus <haus@uuhaus.de>, Johan Hovold <jhovold@gmail.com>"
  53 #define DRIVER_DESC "KLSI KL5KUSB105 chipset USB->Serial Converter driver"
  54
  55
  56 /*
  57  * Function prototypes
  58  */
  59 static int klsi_105_port_probe(struct usb_serial_port *port);
  60 static int klsi_105_port_remove(struct usb_serial_port *port);
  61 static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port);
  62 static void klsi_105_close(struct usb_serial_port *port);
  63 static void klsi_105_set_termios(struct tty_struct *tty,
  64                         struct usb_serial_port *port, struct ktermios *old);
  65 static int  klsi_105_tiocmget(struct tty_struct *tty);
  66 static int  klsi_105_tiocmset(struct tty_struct *tty,
  67                         unsigned int set, unsigned int clear);
  68 static void klsi_105_process_read_urb(struct urb *urb);
  69 static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
  70                                                 void *dest, size_t size);
  71
  72 /*
  73  * All of the device info needed for the KLSI converters.
  74  */
  75 static const struct usb_device_id id_table[] = {
  76         { USB_DEVICE(PALMCONNECT_VID, PALMCONNECT_PID) },
  77         { USB_DEVICE(KLSI_VID, KLSI_KL5KUSB105D_PID) },
  78         { }             /* Terminating entry */
  79 };
  80
  81 MODULE_DEVICE_TABLE(usb, id_table);
  82
  83 static struct usb_serial_driver kl5kusb105d_device = {
  84         .driver = {
  85                 .owner =        THIS_MODULE,
  86                 .name =         "kl5kusb105d",
  87         },
  88         .description =          "KL5KUSB105D / PalmConnect",
  89         .id_table =             id_table,
  90         .num_ports =            1,
  91         .bulk_out_size =        64,
  92         .open =                 klsi_105_open,
  93         .close =                klsi_105_close,
  94         .set_termios =          klsi_105_set_termios,
  95         /*.break_ctl =          klsi_105_break_ctl,*/
  96         .tiocmget =             klsi_105_tiocmget,
  97         .tiocmset =             klsi_105_tiocmset,
  98         .port_probe =           klsi_105_port_probe,
  99         .port_remove =          klsi_105_port_remove,
 100         .throttle =             usb_serial_generic_throttle,
 101         .unthrottle =           usb_serial_generic_unthrottle,
 102         .process_read_urb =     klsi_105_process_read_urb,
 103         .prepare_write_buffer = klsi_105_prepare_write_buffer,
 104 };
 105
 106 static struct usb_serial_driver * const serial_drivers[] = {
 107         &kl5kusb105d_device, NULL
 108 };
 109
 110 struct klsi_105_port_settings {
 111         __u8    pktlen;         /* always 5, it seems */
 112         __u8    baudrate;
 113         __u8    databits;
 114         __u8    unknown1;
 115         __u8    unknown2;
 116 } __attribute__ ((packed));
 117
 118 struct klsi_105_private {
 119         struct klsi_105_port_settings   cfg;
 120         struct ktermios                 termios;
 121         unsigned long                   line_state; /* modem line settings */
 122         spinlock_t                      lock;
 123 };
 124
 125
 126 /*
 127  * Handle vendor specific USB requests
 128  */
 129
 130
 131 #define KLSI_TIMEOUT     5000 /* default urb timeout */
 132
 133 static int klsi_105_chg_port_settings(struct usb_serial_port *port,
 134                                       struct klsi_105_port_settings *settings)
 135 {
 136         int rc;
 137
 138         rc = usb_control_msg(port->serial->dev,
 139                         usb_sndctrlpipe(port->serial->dev, 0),
 140                         KL5KUSB105A_SIO_SET_DATA,
 141                         USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_INTERFACE,
 142                         0, /* value */
 143                         0, /* index */
 144                         settings,
 145                         sizeof(struct klsi_105_port_settings),
 146                         KLSI_TIMEOUT);
 147         if (rc < 0)
 148                 dev_err(&port->dev,
 149                         "Change port settings failed (error = %d)\n", rc);
 150         dev_info(&port->serial->dev->dev,
 151                  "%d byte block, baudrate %x, databits %d, u1 %d, u2 %d\n",
 152                  settings->pktlen, settings->baudrate, settings->databits,
 153                  settings->unknown1, settings->unknown2);
 154         return rc;
 155 }
 156
 157 /* translate a 16-bit status value from the device to linux's TIO bits */
 158 static unsigned long klsi_105_status2linestate(const __u16 status)
 159 {
 160         unsigned long res = 0;
 161
 162         res =   ((status & KL5KUSB105A_DSR) ? TIOCM_DSR : 0)
 163               | ((status & KL5KUSB105A_CTS) ? TIOCM_CTS : 0)
 164               ;
 165
 166         return res;
 167 }
 168
 169 /*
 170  * Read line control via vendor command and return result through
 171  * *line_state_p
 172  */
 173 /* It seems that the status buffer has always only 2 bytes length */
 174 #define KLSI_STATUSBUF_LEN      2
 175 static int klsi_105_get_line_state(struct usb_serial_port *port,
 176                                    unsigned long *line_state_p)
 177 {
 178         int rc;
 179         u8 *status_buf;
 180         __u16 status;
 181
 182         dev_info(&port->serial->dev->dev, "sending SIO Poll request\n");
 183
 184         status_buf = kmalloc(KLSI_STATUSBUF_LEN, GFP_KERNEL);
 185         if (!status_buf) {
 186                 dev_err(&port->dev, "%s - out of memory for status buffer.\n",
 187                                 __func__);
 188                 return -ENOMEM;
 189         }
 190         status_buf[0] = 0xff;
 191         status_buf[1] = 0xff;
 192         rc = usb_control_msg(port->serial->dev,
 193                              usb_rcvctrlpipe(port->serial->dev, 0),
 194                              KL5KUSB105A_SIO_POLL,
 195                              USB_TYPE_VENDOR | USB_DIR_IN,
 196                              0, /* value */
 197                              0, /* index */
 198                              status_buf, KLSI_STATUSBUF_LEN,
 199                              10000
 200                              );
 201         if (rc < 0)
 202                 dev_err(&port->dev, "Reading line status failed (error = %d)\n",
 203                         rc);
 204         else {
 205                 status = get_unaligned_le16(status_buf);
 206
 207                 dev_info(&port->serial->dev->dev, "read status %x %x",
 208                          status_buf[0], status_buf[1]);
 209
 210                 *line_state_p = klsi_105_status2linestate(status);
 211         }
 212
 213         kfree(status_buf);
 214         return rc;
 215 }
 216
 217
 218 /*
 219  * Driver's tty interface functions
 220  */
 221
 222 static int klsi_105_port_probe(struct usb_serial_port *port)
 223 {
 224         struct klsi_105_private *priv;
 225
 226         priv = kmalloc(sizeof(*priv), GFP_KERNEL);
 227         if (!priv)
 228                 return -ENOMEM;
 229
 230         /* set initial values for control structures */
 231         priv->cfg.pktlen    = 5;
 232         priv->cfg.baudrate  = kl5kusb105a_sio_b9600;
 233         priv->cfg.databits  = kl5kusb105a_dtb_8;
 234         priv->cfg.unknown1  = 0;
 235         priv->cfg.unknown2  = 1;
 236
 237         priv->line_state    = 0;
 238
 239         spin_lock_init(&priv->lock);
 240
 241         /* priv->termios is left uninitialized until port opening */
 242
 243         usb_set_serial_port_data(port, priv);
 244
 245         return 0;
 246 }
 247
 248 static int klsi_105_port_remove(struct usb_serial_port *port)
 249 {
 250         struct klsi_105_private *priv;
 251
 252         priv = usb_get_serial_port_data(port);
 253         kfree(priv);
 254
 255         return 0;
 256 }
 257
 258 static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port)
 259 {
 260         struct klsi_105_private *priv = usb_get_serial_port_data(port);
 261         int retval = 0;
 262         int rc;
 263         int i;
 264         unsigned long line_state;
 265         struct klsi_105_port_settings *cfg;
 266         unsigned long flags;
 267
 268         /* Do a defined restart:
 269          * Set up sane default baud rate and send the 'READ_ON'
 270          * vendor command.
 271          * FIXME: set modem line control (how?)
 272          * Then read the modem line control and store values in
 273          * priv->line_state.
 274          */
 275         cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
 276         if (!cfg) {
 277                 dev_err(&port->dev, "%s - out of memory for config buffer.\n",
 278                                 __func__);
 279                 return -ENOMEM;
 280         }
 281         cfg->pktlen   = 5;
 282         cfg->baudrate = kl5kusb105a_sio_b9600;
 283         cfg->databits = kl5kusb105a_dtb_8;
 284         cfg->unknown1 = 0;
 285         cfg->unknown2 = 1;
 286         klsi_105_chg_port_settings(port, cfg);
 287
 288         /* set up termios structure */
 289         spin_lock_irqsave(&priv->lock, flags);
 290         priv->termios.c_iflag = tty->termios.c_iflag;
 291         priv->termios.c_oflag = tty->termios.c_oflag;
 292         priv->termios.c_cflag = tty->termios.c_cflag;
 293         priv->termios.c_lflag = tty->termios.c_lflag;
 294         for (i = 0; i < NCCS; i++)
 295                 priv->termios.c_cc[i] = tty->termios.c_cc[i];
 296         priv->cfg.pktlen   = cfg->pktlen;
 297         priv->cfg.baudrate = cfg->baudrate;
 298         priv->cfg.databits = cfg->databits;
 299         priv->cfg.unknown1 = cfg->unknown1;
 300         priv->cfg.unknown2 = cfg->unknown2;
 301         spin_unlock_irqrestore(&priv->lock, flags);
 302
 303         /* READ_ON and urb submission */
 304         rc = usb_serial_generic_open(tty, port);
 305         if (rc) {
 306                 retval = rc;
 307                 goto exit;
 308         }
 309
 310         rc = usb_control_msg(port->serial->dev,
 311                              usb_sndctrlpipe(port->serial->dev, 0),
 312                              KL5KUSB105A_SIO_CONFIGURE,
 313                              USB_TYPE_VENDOR|USB_DIR_OUT|USB_RECIP_INTERFACE,
 314                              KL5KUSB105A_SIO_CONFIGURE_READ_ON,
 315                              0, /* index */
 316                              NULL,
 317                              0,
 318                              KLSI_TIMEOUT);
 319         if (rc < 0) {
 320                 dev_err(&port->dev, "Enabling read failed (error = %d)\n", rc);
 321                 retval = rc;
 322         } else
 323                 dev_dbg(&port->dev, "%s - enabled reading\n", __func__);
 324
 325         rc = klsi_105_get_line_state(port, &line_state);
 326         if (rc >= 0) {
 327                 spin_lock_irqsave(&priv->lock, flags);
 328                 priv->line_state = line_state;
 329                 spin_unlock_irqrestore(&priv->lock, flags);
 330                 dev_dbg(&port->dev, "%s - read line state 0x%lx\n", __func__, line_state);
 331                 retval = 0;
 332         } else
 333                 retval = rc;
 334
 335 exit:
 336         kfree(cfg);
 337         return retval;
 338 }
 339
 340 static void klsi_105_close(struct usb_serial_port *port)
 341 {
 342         int rc;
 343
 344         mutex_lock(&port->serial->disc_mutex);
 345         if (!port->serial->disconnected) {
 346                 /* send READ_OFF */
 347                 rc = usb_control_msg(port->serial->dev,
 348                                      usb_sndctrlpipe(port->serial->dev, 0),
 349                                      KL5KUSB105A_SIO_CONFIGURE,
 350                                      USB_TYPE_VENDOR | USB_DIR_OUT,
 351                                      KL5KUSB105A_SIO_CONFIGURE_READ_OFF,
 352                                      0, /* index */
 353                                      NULL, 0,
 354                                      KLSI_TIMEOUT);
 355                 if (rc < 0)
 356                         dev_err(&port->dev,
 357                                 "Disabling read failed (error = %d)\n", rc);
 358         }
 359         mutex_unlock(&port->serial->disc_mutex);
 360
 361         /* shutdown our bulk reads and writes */
 362         usb_serial_generic_close(port);
 363
 364         /* wgg - do I need this? I think so. */
 365         usb_kill_urb(port->interrupt_in_urb);
 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         struct tty_struct *tty;
 393         unsigned len;
 394
 395         /* empty urbs seem to happen, we ignore them */
 396         if (!urb->actual_length)
 397                 return;
 398
 399         if (urb->actual_length <= KLSI_HDR_LEN) {
 400                 dev_dbg(&port->dev, "%s - malformed packet\n", __func__);
 401                 return;
 402         }
 403
 404         tty = tty_port_tty_get(&port->port);
 405         if (!tty)
 406                 return;
 407
 408         len = get_unaligned_le16(data);
 409         if (len > urb->actual_length - KLSI_HDR_LEN) {
 410                 dev_dbg(&port->dev, "%s - packet length mismatch\n", __func__);
 411                 len = urb->actual_length - KLSI_HDR_LEN;
 412         }
 413
 414         tty_insert_flip_string(tty, data + KLSI_HDR_LEN, len);
 415         tty_flip_buffer_push(tty);
 416         tty_kref_put(tty);
 417 }
 418
 419 static void klsi_105_set_termios(struct tty_struct *tty,
 420                                  struct usb_serial_port *port,
 421                                  struct ktermios *old_termios)
 422 {
 423         struct klsi_105_private *priv = usb_get_serial_port_data(port);
 424         struct device *dev = &port->dev;
 425         unsigned int iflag = tty->termios.c_iflag;
 426         unsigned int old_iflag = old_termios->c_iflag;
 427         unsigned int cflag = tty->termios.c_cflag;
 428         unsigned int old_cflag = old_termios->c_cflag;
 429         struct klsi_105_port_settings *cfg;
 430         unsigned long flags;
 431         speed_t baud;
 432
 433         cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
 434         if (!cfg) {
 435                 dev_err(dev, "%s - out of memory for config buffer.\n", __func__);
 436                 return;
 437         }
 438
 439         /* lock while we are modifying the settings */
 440         spin_lock_irqsave(&priv->lock, flags);
 441
 442         /*
 443          * Update baud rate
 444          */
 445         baud = tty_get_baud_rate(tty);
 446
 447         if ((cflag & CBAUD) != (old_cflag & CBAUD)) {
 448                 /* reassert DTR and (maybe) RTS on transition from B0 */
 449                 if ((old_cflag & CBAUD) == B0) {
 450                         dev_dbg(dev, "%s: baud was B0\n", __func__);
 451 #if 0
 452                         priv->control_state |= TIOCM_DTR;
 453                         /* don't set RTS if using hardware flow control */
 454                         if (!(old_cflag & CRTSCTS))
 455                                 priv->control_state |= TIOCM_RTS;
 456                         mct_u232_set_modem_ctrl(serial, priv->control_state);
 457 #endif
 458                 }
 459         }
 460         switch (baud) {
 461         case 0: /* handled below */
 462                 break;
 463         case 1200:
 464                 priv->cfg.baudrate = kl5kusb105a_sio_b1200;
 465                 break;
 466         case 2400:
 467                 priv->cfg.baudrate = kl5kusb105a_sio_b2400;
 468                 break;
 469         case 4800:
 470                 priv->cfg.baudrate = kl5kusb105a_sio_b4800;
 471                 break;
 472         case 9600:
 473                 priv->cfg.baudrate = kl5kusb105a_sio_b9600;
 474                 break;
 475         case 19200:
 476                 priv->cfg.baudrate = kl5kusb105a_sio_b19200;
 477                 break;
 478         case 38400:
 479                 priv->cfg.baudrate = kl5kusb105a_sio_b38400;
 480                 break;
 481         case 57600:
 482                 priv->cfg.baudrate = kl5kusb105a_sio_b57600;
 483                 break;
 484         case 115200:
 485                 priv->cfg.baudrate = kl5kusb105a_sio_b115200;
 486                 break;
 487         default:
 488                 dev_dbg(dev, "KLSI USB->Serial converter: unsupported baudrate request, using default of 9600");
 489                 priv->cfg.baudrate = kl5kusb105a_sio_b9600;
 490                 baud = 9600;
 491                 break;
 492         }
 493         if ((cflag & CBAUD) == B0) {
 494                 dev_dbg(dev, "%s: baud is B0\n", __func__);
 495                 /* Drop RTS and DTR */
 496                 /* maybe this should be simulated by sending read
 497                  * disable and read enable messages?
 498                  */
 499                 ;
 500 #if 0
 501                 priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
 502                 mct_u232_set_modem_ctrl(serial, priv->control_state);
 503 #endif
 504         }
 505         tty_encode_baud_rate(tty, baud, baud);
 506
 507         if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
 508                 /* set the number of data bits */
 509                 switch (cflag & CSIZE) {
 510                 case CS5:
 511                         dev_dbg(dev, "%s - 5 bits/byte not supported\n", __func__);
 512                         spin_unlock_irqrestore(&priv->lock, flags);
 513                         goto err;
 514                 case CS6:
 515                         dev_dbg(dev, "%s - 6 bits/byte not supported\n", __func__);
 516                         spin_unlock_irqrestore(&priv->lock, flags);
 517                         goto err;
 518                 case CS7:
 519                         priv->cfg.databits = kl5kusb105a_dtb_7;
 520                         break;
 521                 case CS8:
 522                         priv->cfg.databits = kl5kusb105a_dtb_8;
 523                         break;
 524                 default:
 525                         dev_err(dev, "CSIZE was not CS5-CS8, using default of 8\n");
 526                         priv->cfg.databits = kl5kusb105a_dtb_8;
 527                         break;
 528                 }
 529         }
 530
 531         /*
 532          * Update line control register (LCR)
 533          */
 534         if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))
 535             || (cflag & CSTOPB) != (old_cflag & CSTOPB)) {
 536                 /* Not currently supported */
 537                 tty->termios.c_cflag &= ~(PARENB|PARODD|CSTOPB);
 538 #if 0
 539                 priv->last_lcr = 0;
 540
 541                 /* set the parity */
 542                 if (cflag & PARENB)
 543                         priv->last_lcr |= (cflag & PARODD) ?
 544                                 MCT_U232_PARITY_ODD : MCT_U232_PARITY_EVEN;
 545                 else
 546                         priv->last_lcr |= MCT_U232_PARITY_NONE;
 547
 548                 /* set the number of stop bits */
 549                 priv->last_lcr |= (cflag & CSTOPB) ?
 550                         MCT_U232_STOP_BITS_2 : MCT_U232_STOP_BITS_1;
 551
 552                 mct_u232_set_line_ctrl(serial, priv->last_lcr);
 553 #endif
 554                 ;
 555         }
 556         /*
 557          * Set flow control: well, I do not really now how to handle DTR/RTS.
 558          * Just do what we have seen with SniffUSB on Win98.
 559          */
 560         if ((iflag & IXOFF) != (old_iflag & IXOFF)
 561             || (iflag & IXON) != (old_iflag & IXON)
 562             ||  (cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
 563                 /* Not currently supported */
 564                 tty->termios.c_cflag &= ~CRTSCTS;
 565                 /* Drop DTR/RTS if no flow control otherwise assert */
 566 #if 0
 567                 if ((iflag & IXOFF) || (iflag & IXON) || (cflag & CRTSCTS))
 568                         priv->control_state |= TIOCM_DTR | TIOCM_RTS;
 569                 else
 570                         priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
 571                 mct_u232_set_modem_ctrl(serial, priv->control_state);
 572 #endif
 573                 ;
 574         }
 575         memcpy(cfg, &priv->cfg, sizeof(*cfg));
 576         spin_unlock_irqrestore(&priv->lock, flags);
 577
 578         /* now commit changes to device */
 579         klsi_105_chg_port_settings(port, cfg);
 580 err:
 581         kfree(cfg);
 582 }
 583
 584 #if 0
 585 static void mct_u232_break_ctl(struct tty_struct *tty, int break_state)
 586 {
 587         struct usb_serial_port *port = tty->driver_data;
 588         struct usb_serial *serial = port->serial;
 589         struct mct_u232_private *priv =
 590                                 (struct mct_u232_private *)port->private;
 591         unsigned char lcr = priv->last_lcr;
 592
 593         dev_dbg(&port->dev, "%s - state=%d\n", __func__, break_state);
 594
 595         /* LOCKING */
 596         if (break_state)
 597                 lcr |= MCT_U232_SET_BREAK;
 598
 599         mct_u232_set_line_ctrl(serial, lcr);
 600 }
 601 #endif
 602
 603 static int klsi_105_tiocmget(struct tty_struct *tty)
 604 {
 605         struct usb_serial_port *port = tty->driver_data;
 606         struct klsi_105_private *priv = usb_get_serial_port_data(port);
 607         unsigned long flags;
 608         int rc;
 609         unsigned long line_state;
 610
 611         rc = klsi_105_get_line_state(port, &line_state);
 612         if (rc < 0) {
 613                 dev_err(&port->dev,
 614                         "Reading line control failed (error = %d)\n", rc);
 615                 /* better return value? EAGAIN? */
 616                 return rc;
 617         }
 618
 619         spin_lock_irqsave(&priv->lock, flags);
 620         priv->line_state = line_state;
 621         spin_unlock_irqrestore(&priv->lock, flags);
 622         dev_dbg(&port->dev, "%s - read line state 0x%lx\n", __func__, line_state);
 623         return (int)line_state;
 624 }
 625
 626 static int klsi_105_tiocmset(struct tty_struct *tty,
 627                              unsigned int set, unsigned int clear)
 628 {
 629         int retval = -EINVAL;
 630
 631 /* if this ever gets implemented, it should be done something like this:
 632         struct usb_serial *serial = port->serial;
 633         struct klsi_105_private *priv = usb_get_serial_port_data(port);
 634         unsigned long flags;
 635         int control;
 636
 637         spin_lock_irqsave (&priv->lock, flags);
 638         if (set & TIOCM_RTS)
 639                 priv->control_state |= TIOCM_RTS;
 640         if (set & TIOCM_DTR)
 641                 priv->control_state |= TIOCM_DTR;
 642         if (clear & TIOCM_RTS)
 643                 priv->control_state &= ~TIOCM_RTS;
 644         if (clear & TIOCM_DTR)
 645                 priv->control_state &= ~TIOCM_DTR;
 646         control = priv->control_state;
 647         spin_unlock_irqrestore (&priv->lock, flags);
 648         retval = mct_u232_set_modem_ctrl(serial, control);
 649 */
 650         return retval;
 651 }
 652
 653 module_usb_serial_driver(serial_drivers, id_table);
 654
 655 MODULE_AUTHOR(DRIVER_AUTHOR);
 656 MODULE_DESCRIPTION(DRIVER_DESC);
 657 MODULE_LICENSE("GPL");