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 /*
  53  * Version Information
  54  */
  55 #define DRIVER_VERSION "v0.4"
  56 #define DRIVER_AUTHOR "Utz-Uwe Haus <haus@uuhaus.de>, Johan Hovold <jhovold@gmail.com>"
  57 #define DRIVER_DESC "KLSI KL5KUSB105 chipset USB->Serial Converter driver"
  58
  59
  60 /*
  61  * Function prototypes
  62  */
  63 static int klsi_105_port_probe(struct usb_serial_port *port);
  64 static int klsi_105_port_remove(struct usb_serial_port *port);
  65 static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port);
  66 static void klsi_105_close(struct usb_serial_port *port);
  67 static void klsi_105_set_termios(struct tty_struct *tty,
  68                         struct usb_serial_port *port, struct ktermios *old);
  69 static int  klsi_105_tiocmget(struct tty_struct *tty);
  70 static int  klsi_105_tiocmset(struct tty_struct *tty,
  71                         unsigned int set, unsigned int clear);
  72 static void klsi_105_process_read_urb(struct urb *urb);
  73 static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
  74                                                 void *dest, size_t size);
  75
  76 /*
  77  * All of the device info needed for the KLSI converters.
  78  */
  79 static const struct usb_device_id id_table[] = {
  80         { USB_DEVICE(PALMCONNECT_VID, PALMCONNECT_PID) },
  81         { USB_DEVICE(KLSI_VID, KLSI_KL5KUSB105D_PID) },
  82         { }             /* Terminating entry */
  83 };
  84
  85 MODULE_DEVICE_TABLE(usb, id_table);
  86
  87 static struct usb_serial_driver kl5kusb105d_device = {
  88         .driver = {
  89                 .owner =        THIS_MODULE,
  90                 .name =         "kl5kusb105d",
  91         },
  92         .description =          "KL5KUSB105D / PalmConnect",
  93         .id_table =             id_table,
  94         .num_ports =            1,
  95         .bulk_out_size =        64,
  96         .open =                 klsi_105_open,
  97         .close =                klsi_105_close,
  98         .set_termios =          klsi_105_set_termios,
  99         /*.break_ctl =          klsi_105_break_ctl,*/
 100         .tiocmget =             klsi_105_tiocmget,
 101         .tiocmset =             klsi_105_tiocmset,
 102         .port_probe =           klsi_105_port_probe,
 103         .port_remove =          klsi_105_port_remove,
 104         .throttle =             usb_serial_generic_throttle,
 105         .unthrottle =           usb_serial_generic_unthrottle,
 106         .process_read_urb =     klsi_105_process_read_urb,
 107         .prepare_write_buffer = klsi_105_prepare_write_buffer,
 108 };
 109
 110 static struct usb_serial_driver * const serial_drivers[] = {
 111         &kl5kusb105d_device, NULL
 112 };
 113
 114 struct klsi_105_port_settings {
 115         __u8    pktlen;         /* always 5, it seems */
 116         __u8    baudrate;
 117         __u8    databits;
 118         __u8    unknown1;
 119         __u8    unknown2;
 120 } __attribute__ ((packed));
 121
 122 struct klsi_105_private {
 123         struct klsi_105_port_settings   cfg;
 124         struct ktermios                 termios;
 125         unsigned long                   line_state; /* modem line settings */
 126         spinlock_t                      lock;
 127 };
 128
 129
 130 /*
 131  * Handle vendor specific USB requests
 132  */
 133
 134
 135 #define KLSI_TIMEOUT     5000 /* default urb timeout */
 136
 137 static int klsi_105_chg_port_settings(struct usb_serial_port *port,
 138                                       struct klsi_105_port_settings *settings)
 139 {
 140         int rc;
 141
 142         rc = usb_control_msg(port->serial->dev,
 143                         usb_sndctrlpipe(port->serial->dev, 0),
 144                         KL5KUSB105A_SIO_SET_DATA,
 145                         USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_INTERFACE,
 146                         0, /* value */
 147                         0, /* index */
 148                         settings,
 149                         sizeof(struct klsi_105_port_settings),
 150                         KLSI_TIMEOUT);
 151         if (rc < 0)
 152                 dev_err(&port->dev,
 153                         "Change port settings failed (error = %d)\n", rc);
 154         dev_info(&port->serial->dev->dev,
 155                  "%d byte block, baudrate %x, databits %d, u1 %d, u2 %d\n",
 156                  settings->pktlen, settings->baudrate, settings->databits,
 157                  settings->unknown1, settings->unknown2);
 158         return rc;
 159 }
 160
 161 /* translate a 16-bit status value from the device to linux's TIO bits */
 162 static unsigned long klsi_105_status2linestate(const __u16 status)
 163 {
 164         unsigned long res = 0;
 165
 166         res =   ((status & KL5KUSB105A_DSR) ? TIOCM_DSR : 0)
 167               | ((status & KL5KUSB105A_CTS) ? TIOCM_CTS : 0)
 168               ;
 169
 170         return res;
 171 }
 172
 173 /*
 174  * Read line control via vendor command and return result through
 175  * *line_state_p
 176  */
 177 /* It seems that the status buffer has always only 2 bytes length */
 178 #define KLSI_STATUSBUF_LEN      2
 179 static int klsi_105_get_line_state(struct usb_serial_port *port,
 180                                    unsigned long *line_state_p)
 181 {
 182         int rc;
 183         u8 *status_buf;
 184         __u16 status;
 185
 186         dev_info(&port->serial->dev->dev, "sending SIO Poll request\n");
 187
 188         status_buf = kmalloc(KLSI_STATUSBUF_LEN, GFP_KERNEL);
 189         if (!status_buf) {
 190                 dev_err(&port->dev, "%s - out of memory for status buffer.\n",
 191                                 __func__);
 192                 return -ENOMEM;
 193         }
 194         status_buf[0] = 0xff;
 195         status_buf[1] = 0xff;
 196         rc = usb_control_msg(port->serial->dev,
 197                              usb_rcvctrlpipe(port->serial->dev, 0),
 198                              KL5KUSB105A_SIO_POLL,
 199                              USB_TYPE_VENDOR | USB_DIR_IN,
 200                              0, /* value */
 201                              0, /* index */
 202                              status_buf, KLSI_STATUSBUF_LEN,
 203                              10000
 204                              );
 205         if (rc < 0)
 206                 dev_err(&port->dev, "Reading line status failed (error = %d)\n",
 207                         rc);
 208         else {
 209                 status = get_unaligned_le16(status_buf);
 210
 211                 dev_info(&port->serial->dev->dev, "read status %x %x",
 212                          status_buf[0], status_buf[1]);
 213
 214                 *line_state_p = klsi_105_status2linestate(status);
 215         }
 216
 217         kfree(status_buf);
 218         return rc;
 219 }
 220
 221
 222 /*
 223  * Driver's tty interface functions
 224  */
 225
 226 static int klsi_105_port_probe(struct usb_serial_port *port)
 227 {
 228         struct klsi_105_private *priv;
 229
 230         priv = kmalloc(sizeof(*priv), GFP_KERNEL);
 231         if (!priv)
 232                 return -ENOMEM;
 233
 234         /* set initial values for control structures */
 235         priv->cfg.pktlen    = 5;
 236         priv->cfg.baudrate  = kl5kusb105a_sio_b9600;
 237         priv->cfg.databits  = kl5kusb105a_dtb_8;
 238         priv->cfg.unknown1  = 0;
 239         priv->cfg.unknown2  = 1;
 240
 241         priv->line_state    = 0;
 242
 243         spin_lock_init(&priv->lock);
 244
 245         /* priv->termios is left uninitialized until port opening */
 246
 247         usb_set_serial_port_data(port, priv);
 248
 249         return 0;
 250 }
 251
 252 static int klsi_105_port_remove(struct usb_serial_port *port)
 253 {
 254         struct klsi_105_private *priv;
 255
 256         priv = usb_get_serial_port_data(port);
 257         kfree(priv);
 258
 259         return 0;
 260 }
 261
 262 static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port)
 263 {
 264         struct klsi_105_private *priv = usb_get_serial_port_data(port);
 265         int retval = 0;
 266         int rc;
 267         int i;
 268         unsigned long line_state;
 269         struct klsi_105_port_settings *cfg;
 270         unsigned long flags;
 271
 272         /* Do a defined restart:
 273          * Set up sane default baud rate and send the 'READ_ON'
 274          * vendor command.
 275          * FIXME: set modem line control (how?)
 276          * Then read the modem line control and store values in
 277          * priv->line_state.
 278          */
 279         cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
 280         if (!cfg) {
 281                 dev_err(&port->dev, "%s - out of memory for config buffer.\n",
 282                                 __func__);
 283                 return -ENOMEM;
 284         }
 285         cfg->pktlen   = 5;
 286         cfg->baudrate = kl5kusb105a_sio_b9600;
 287         cfg->databits = kl5kusb105a_dtb_8;
 288         cfg->unknown1 = 0;
 289         cfg->unknown2 = 1;
 290         klsi_105_chg_port_settings(port, cfg);
 291
 292         /* set up termios structure */
 293         spin_lock_irqsave(&priv->lock, flags);
 294         priv->termios.c_iflag = tty->termios.c_iflag;
 295         priv->termios.c_oflag = tty->termios.c_oflag;
 296         priv->termios.c_cflag = tty->termios.c_cflag;
 297         priv->termios.c_lflag = tty->termios.c_lflag;
 298         for (i = 0; i < NCCS; i++)
 299                 priv->termios.c_cc[i] = tty->termios.c_cc[i];
 300         priv->cfg.pktlen   = cfg->pktlen;
 301         priv->cfg.baudrate = cfg->baudrate;
 302         priv->cfg.databits = cfg->databits;
 303         priv->cfg.unknown1 = cfg->unknown1;
 304         priv->cfg.unknown2 = cfg->unknown2;
 305         spin_unlock_irqrestore(&priv->lock, flags);
 306
 307         /* READ_ON and urb submission */
 308         rc = usb_serial_generic_open(tty, port);
 309         if (rc) {
 310                 retval = rc;
 311                 goto exit;
 312         }
 313
 314         rc = usb_control_msg(port->serial->dev,
 315                              usb_sndctrlpipe(port->serial->dev, 0),
 316                              KL5KUSB105A_SIO_CONFIGURE,
 317                              USB_TYPE_VENDOR|USB_DIR_OUT|USB_RECIP_INTERFACE,
 318                              KL5KUSB105A_SIO_CONFIGURE_READ_ON,
 319                              0, /* index */
 320                              NULL,
 321                              0,
 322                              KLSI_TIMEOUT);
 323         if (rc < 0) {
 324                 dev_err(&port->dev, "Enabling read failed (error = %d)\n", rc);
 325                 retval = rc;
 326         } else
 327                 dev_dbg(&port->dev, "%s - enabled reading\n", __func__);
 328
 329         rc = klsi_105_get_line_state(port, &line_state);
 330         if (rc >= 0) {
 331                 spin_lock_irqsave(&priv->lock, flags);
 332                 priv->line_state = line_state;
 333                 spin_unlock_irqrestore(&priv->lock, flags);
 334                 dev_dbg(&port->dev, "%s - read line state 0x%lx\n", __func__, line_state);
 335                 retval = 0;
 336         } else
 337                 retval = rc;
 338
 339 exit:
 340         kfree(cfg);
 341         return retval;
 342 }
 343
 344 static void klsi_105_close(struct usb_serial_port *port)
 345 {
 346         int rc;
 347
 348         mutex_lock(&port->serial->disc_mutex);
 349         if (!port->serial->disconnected) {
 350                 /* send READ_OFF */
 351                 rc = usb_control_msg(port->serial->dev,
 352                                      usb_sndctrlpipe(port->serial->dev, 0),
 353                                      KL5KUSB105A_SIO_CONFIGURE,
 354                                      USB_TYPE_VENDOR | USB_DIR_OUT,
 355                                      KL5KUSB105A_SIO_CONFIGURE_READ_OFF,
 356                                      0, /* index */
 357                                      NULL, 0,
 358                                      KLSI_TIMEOUT);
 359                 if (rc < 0)
 360                         dev_err(&port->dev,
 361                                 "Disabling read failed (error = %d)\n", rc);
 362         }
 363         mutex_unlock(&port->serial->disc_mutex);
 364
 365         /* shutdown our bulk reads and writes */
 366         usb_serial_generic_close(port);
 367
 368         /* wgg - do I need this? I think so. */
 369         usb_kill_urb(port->interrupt_in_urb);
 370 }
 371
 372 /* We need to write a complete 64-byte data block and encode the
 373  * number actually sent in the first double-byte, LSB-order. That
 374  * leaves at most 62 bytes of payload.
 375  */
 376 #define KLSI_HDR_LEN            2
 377 static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
 378                                                 void *dest, size_t size)
 379 {
 380         unsigned char *buf = dest;
 381         int count;
 382
 383         count = kfifo_out_locked(&port->write_fifo, buf + KLSI_HDR_LEN, size,
 384                                                                 &port->lock);
 385         put_unaligned_le16(count, buf);
 386
 387         return count + KLSI_HDR_LEN;
 388 }
 389
 390 /* The data received is preceded by a length double-byte in LSB-first order.
 391  */
 392 static void klsi_105_process_read_urb(struct urb *urb)
 393 {
 394         struct usb_serial_port *port = urb->context;
 395         unsigned char *data = urb->transfer_buffer;
 396         struct tty_struct *tty;
 397         unsigned len;
 398
 399         /* empty urbs seem to happen, we ignore them */
 400         if (!urb->actual_length)
 401                 return;
 402
 403         if (urb->actual_length <= KLSI_HDR_LEN) {
 404                 dev_dbg(&port->dev, "%s - malformed packet\n", __func__);
 405                 return;
 406         }
 407
 408         tty = tty_port_tty_get(&port->port);
 409         if (!tty)
 410                 return;
 411
 412         len = get_unaligned_le16(data);
 413         if (len > urb->actual_length - KLSI_HDR_LEN) {
 414                 dev_dbg(&port->dev, "%s - packet length mismatch\n", __func__);
 415                 len = urb->actual_length - KLSI_HDR_LEN;
 416         }
 417
 418         tty_insert_flip_string(tty, data + KLSI_HDR_LEN, len);
 419         tty_flip_buffer_push(tty);
 420         tty_kref_put(tty);
 421 }
 422
 423 static void klsi_105_set_termios(struct tty_struct *tty,
 424                                  struct usb_serial_port *port,
 425                                  struct ktermios *old_termios)
 426 {
 427         struct klsi_105_private *priv = usb_get_serial_port_data(port);
 428         struct device *dev = &port->dev;
 429         unsigned int iflag = tty->termios.c_iflag;
 430         unsigned int old_iflag = old_termios->c_iflag;
 431         unsigned int cflag = tty->termios.c_cflag;
 432         unsigned int old_cflag = old_termios->c_cflag;
 433         struct klsi_105_port_settings *cfg;
 434         unsigned long flags;
 435         speed_t baud;
 436
 437         cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
 438         if (!cfg) {
 439                 dev_err(dev, "%s - out of memory for config buffer.\n", __func__);
 440                 return;
 441         }
 442
 443         /* lock while we are modifying the settings */
 444         spin_lock_irqsave(&priv->lock, flags);
 445
 446         /*
 447          * Update baud rate
 448          */
 449         baud = tty_get_baud_rate(tty);
 450
 451         if ((cflag & CBAUD) != (old_cflag & CBAUD)) {
 452                 /* reassert DTR and (maybe) RTS on transition from B0 */
 453                 if ((old_cflag & CBAUD) == B0) {
 454                         dev_dbg(dev, "%s: baud was B0\n", __func__);
 455 #if 0
 456                         priv->control_state |= TIOCM_DTR;
 457                         /* don't set RTS if using hardware flow control */
 458                         if (!(old_cflag & CRTSCTS))
 459                                 priv->control_state |= TIOCM_RTS;
 460                         mct_u232_set_modem_ctrl(serial, priv->control_state);
 461 #endif
 462                 }
 463         }
 464         switch (baud) {
 465         case 0: /* handled below */
 466                 break;
 467         case 1200:
 468                 priv->cfg.baudrate = kl5kusb105a_sio_b1200;
 469                 break;
 470         case 2400:
 471                 priv->cfg.baudrate = kl5kusb105a_sio_b2400;
 472                 break;
 473         case 4800:
 474                 priv->cfg.baudrate = kl5kusb105a_sio_b4800;
 475                 break;
 476         case 9600:
 477                 priv->cfg.baudrate = kl5kusb105a_sio_b9600;
 478                 break;
 479         case 19200:
 480                 priv->cfg.baudrate = kl5kusb105a_sio_b19200;
 481                 break;
 482         case 38400:
 483                 priv->cfg.baudrate = kl5kusb105a_sio_b38400;
 484                 break;
 485         case 57600:
 486                 priv->cfg.baudrate = kl5kusb105a_sio_b57600;
 487                 break;
 488         case 115200:
 489                 priv->cfg.baudrate = kl5kusb105a_sio_b115200;
 490                 break;
 491         default:
 492                 dev_dbg(dev, "KLSI USB->Serial converter: unsupported baudrate request, using default of 9600");
 493                 priv->cfg.baudrate = kl5kusb105a_sio_b9600;
 494                 baud = 9600;
 495                 break;
 496         }
 497         if ((cflag & CBAUD) == B0) {
 498                 dev_dbg(dev, "%s: baud is B0\n", __func__);
 499                 /* Drop RTS and DTR */
 500                 /* maybe this should be simulated by sending read
 501                  * disable and read enable messages?
 502                  */
 503                 ;
 504 #if 0
 505                 priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
 506                 mct_u232_set_modem_ctrl(serial, priv->control_state);
 507 #endif
 508         }
 509         tty_encode_baud_rate(tty, baud, baud);
 510
 511         if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
 512                 /* set the number of data bits */
 513                 switch (cflag & CSIZE) {
 514                 case CS5:
 515                         dev_dbg(dev, "%s - 5 bits/byte not supported\n", __func__);
 516                         spin_unlock_irqrestore(&priv->lock, flags);
 517                         goto err;
 518                 case CS6:
 519                         dev_dbg(dev, "%s - 6 bits/byte not supported\n", __func__);
 520                         spin_unlock_irqrestore(&priv->lock, flags);
 521                         goto err;
 522                 case CS7:
 523                         priv->cfg.databits = kl5kusb105a_dtb_7;
 524                         break;
 525                 case CS8:
 526                         priv->cfg.databits = kl5kusb105a_dtb_8;
 527                         break;
 528                 default:
 529                         dev_err(dev, "CSIZE was not CS5-CS8, using default of 8\n");
 530                         priv->cfg.databits = kl5kusb105a_dtb_8;
 531                         break;
 532                 }
 533         }
 534
 535         /*
 536          * Update line control register (LCR)
 537          */
 538         if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))
 539             || (cflag & CSTOPB) != (old_cflag & CSTOPB)) {
 540                 /* Not currently supported */
 541                 tty->termios.c_cflag &= ~(PARENB|PARODD|CSTOPB);
 542 #if 0
 543                 priv->last_lcr = 0;
 544
 545                 /* set the parity */
 546                 if (cflag & PARENB)
 547                         priv->last_lcr |= (cflag & PARODD) ?
 548                                 MCT_U232_PARITY_ODD : MCT_U232_PARITY_EVEN;
 549                 else
 550                         priv->last_lcr |= MCT_U232_PARITY_NONE;
 551
 552                 /* set the number of stop bits */
 553                 priv->last_lcr |= (cflag & CSTOPB) ?
 554                         MCT_U232_STOP_BITS_2 : MCT_U232_STOP_BITS_1;
 555
 556                 mct_u232_set_line_ctrl(serial, priv->last_lcr);
 557 #endif
 558                 ;
 559         }
 560         /*
 561          * Set flow control: well, I do not really now how to handle DTR/RTS.
 562          * Just do what we have seen with SniffUSB on Win98.
 563          */
 564         if ((iflag & IXOFF) != (old_iflag & IXOFF)
 565             || (iflag & IXON) != (old_iflag & IXON)
 566             ||  (cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
 567                 /* Not currently supported */
 568                 tty->termios.c_cflag &= ~CRTSCTS;
 569                 /* Drop DTR/RTS if no flow control otherwise assert */
 570 #if 0
 571                 if ((iflag & IXOFF) || (iflag & IXON) || (cflag & CRTSCTS))
 572                         priv->control_state |= TIOCM_DTR | TIOCM_RTS;
 573                 else
 574                         priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
 575                 mct_u232_set_modem_ctrl(serial, priv->control_state);
 576 #endif
 577                 ;
 578         }
 579         memcpy(cfg, &priv->cfg, sizeof(*cfg));
 580         spin_unlock_irqrestore(&priv->lock, flags);
 581
 582         /* now commit changes to device */
 583         klsi_105_chg_port_settings(port, cfg);
 584 err:
 585         kfree(cfg);
 586 }
 587
 588 #if 0
 589 static void mct_u232_break_ctl(struct tty_struct *tty, int break_state)
 590 {
 591         struct usb_serial_port *port = tty->driver_data;
 592         struct usb_serial *serial = port->serial;
 593         struct mct_u232_private *priv =
 594                                 (struct mct_u232_private *)port->private;
 595         unsigned char lcr = priv->last_lcr;
 596
 597         dev_dbg(&port->dev, "%s - state=%d\n", __func__, break_state);
 598
 599         /* LOCKING */
 600         if (break_state)
 601                 lcr |= MCT_U232_SET_BREAK;
 602
 603         mct_u232_set_line_ctrl(serial, lcr);
 604 }
 605 #endif
 606
 607 static int klsi_105_tiocmget(struct tty_struct *tty)
 608 {
 609         struct usb_serial_port *port = tty->driver_data;
 610         struct klsi_105_private *priv = usb_get_serial_port_data(port);
 611         unsigned long flags;
 612         int rc;
 613         unsigned long line_state;
 614
 615         rc = klsi_105_get_line_state(port, &line_state);
 616         if (rc < 0) {
 617                 dev_err(&port->dev,
 618                         "Reading line control failed (error = %d)\n", rc);
 619                 /* better return value? EAGAIN? */
 620                 return rc;
 621         }
 622
 623         spin_lock_irqsave(&priv->lock, flags);
 624         priv->line_state = line_state;
 625         spin_unlock_irqrestore(&priv->lock, flags);
 626         dev_dbg(&port->dev, "%s - read line state 0x%lx\n", __func__, line_state);
 627         return (int)line_state;
 628 }
 629
 630 static int klsi_105_tiocmset(struct tty_struct *tty,
 631                              unsigned int set, unsigned int clear)
 632 {
 633         int retval = -EINVAL;
 634
 635 /* if this ever gets implemented, it should be done something like this:
 636         struct usb_serial *serial = port->serial;
 637         struct klsi_105_private *priv = usb_get_serial_port_data(port);
 638         unsigned long flags;
 639         int control;
 640
 641         spin_lock_irqsave (&priv->lock, flags);
 642         if (set & TIOCM_RTS)
 643                 priv->control_state |= TIOCM_RTS;
 644         if (set & TIOCM_DTR)
 645                 priv->control_state |= TIOCM_DTR;
 646         if (clear & TIOCM_RTS)
 647                 priv->control_state &= ~TIOCM_RTS;
 648         if (clear & TIOCM_DTR)
 649                 priv->control_state &= ~TIOCM_DTR;
 650         control = priv->control_state;
 651         spin_unlock_irqrestore (&priv->lock, flags);
 652         retval = mct_u232_set_modem_ctrl(serial, control);
 653 */
 654         return retval;
 655 }
 656
 657 module_usb_serial_driver(serial_drivers, id_table);
 658
 659 MODULE_AUTHOR(DRIVER_AUTHOR);
 660 MODULE_DESCRIPTION(DRIVER_DESC);
 661 MODULE_LICENSE("GPL");