drivers/usb/serial/mct_u232.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * MCT (Magic Control Technology Corp.) USB RS232 Converter Driver
   4  *
   5  *   Copyright (C) 2000 Wolfgang Grandegger (wolfgang@ces.ch)
   6  *
   7  * This program is largely derived from the Belkin USB Serial Adapter Driver
   8  * (see belkin_sa.[ch]). All of the information about the device was acquired
   9  * by using SniffUSB on Windows98. For technical details see mct_u232.h.
  10  *
  11  * William G. Greathouse and Greg Kroah-Hartman provided great help on how to
  12  * do the reverse engineering and how to write a USB serial device driver.
  13  *
  14  * TO BE DONE, TO BE CHECKED:
  15  *   DTR/RTS signal handling may be incomplete or incorrect. I have mainly
  16  *   implemented what I have seen with SniffUSB or found in belkin_sa.c.
  17  *   For further TODOs check also belkin_sa.c.
  18  */
  19
  20 #include <linux/kernel.h>
  21 #include <linux/errno.h>
  22 #include <linux/slab.h>
  23 #include <linux/tty.h>
  24 #include <linux/tty_driver.h>
  25 #include <linux/tty_flip.h>
  26 #include <linux/module.h>
  27 #include <linux/spinlock.h>
  28 #include <linux/uaccess.h>
  29 #include <asm/unaligned.h>
  30 #include <linux/usb.h>
  31 #include <linux/usb/serial.h>
  32 #include <linux/serial.h>
  33 #include "mct_u232.h"
  34
  35 #define DRIVER_AUTHOR "Wolfgang Grandegger <wolfgang@ces.ch>"
  36 #define DRIVER_DESC "Magic Control Technology USB-RS232 converter driver"
  37
  38 /*
  39  * Function prototypes
  40  */
  41 static int  mct_u232_port_probe(struct usb_serial_port *port);
  42 static void mct_u232_port_remove(struct usb_serial_port *remove);
  43 static int  mct_u232_open(struct tty_struct *tty, struct usb_serial_port *port);
  44 static void mct_u232_close(struct usb_serial_port *port);
  45 static void mct_u232_dtr_rts(struct usb_serial_port *port, int on);
  46 static void mct_u232_read_int_callback(struct urb *urb);
  47 static void mct_u232_set_termios(struct tty_struct *tty,
  48                         struct usb_serial_port *port, struct ktermios *old);
  49 static void mct_u232_break_ctl(struct tty_struct *tty, int break_state);
  50 static int  mct_u232_tiocmget(struct tty_struct *tty);
  51 static int  mct_u232_tiocmset(struct tty_struct *tty,
  52                         unsigned int set, unsigned int clear);
  53 static void mct_u232_throttle(struct tty_struct *tty);
  54 static void mct_u232_unthrottle(struct tty_struct *tty);
  55
  56
  57 /*
  58  * All of the device info needed for the MCT USB-RS232 converter.
  59  */
  60 static const struct usb_device_id id_table[] = {
  61         { USB_DEVICE(MCT_U232_VID, MCT_U232_PID) },
  62         { USB_DEVICE(MCT_U232_VID, MCT_U232_SITECOM_PID) },
  63         { USB_DEVICE(MCT_U232_VID, MCT_U232_DU_H3SP_PID) },
  64         { USB_DEVICE(MCT_U232_BELKIN_F5U109_VID, MCT_U232_BELKIN_F5U109_PID) },
  65         { }             /* Terminating entry */
  66 };
  67 MODULE_DEVICE_TABLE(usb, id_table);
  68
  69 static struct usb_serial_driver mct_u232_device = {
  70         .driver = {
  71                 .owner =        THIS_MODULE,
  72                 .name =         "mct_u232",
  73         },
  74         .description =       "MCT U232",
  75         .id_table =          id_table,
  76         .num_ports =         1,
  77         .open =              mct_u232_open,
  78         .close =             mct_u232_close,
  79         .dtr_rts =           mct_u232_dtr_rts,
  80         .throttle =          mct_u232_throttle,
  81         .unthrottle =        mct_u232_unthrottle,
  82         .read_int_callback = mct_u232_read_int_callback,
  83         .set_termios =       mct_u232_set_termios,
  84         .break_ctl =         mct_u232_break_ctl,
  85         .tiocmget =          mct_u232_tiocmget,
  86         .tiocmset =          mct_u232_tiocmset,
  87         .tiocmiwait =        usb_serial_generic_tiocmiwait,
  88         .port_probe =        mct_u232_port_probe,
  89         .port_remove =       mct_u232_port_remove,
  90         .get_icount =        usb_serial_generic_get_icount,
  91 };
  92
  93 static struct usb_serial_driver * const serial_drivers[] = {
  94         &mct_u232_device, NULL
  95 };
  96
  97 struct mct_u232_private {
  98         struct urb *read_urb;
  99         spinlock_t lock;
 100         unsigned int         control_state; /* Modem Line Setting (TIOCM) */
 101         unsigned char        last_lcr;      /* Line Control Register */
 102         unsigned char        last_lsr;      /* Line Status Register */
 103         unsigned char        last_msr;      /* Modem Status Register */
 104         unsigned int         rx_flags;      /* Throttling flags */
 105 };
 106
 107 #define THROTTLED               0x01
 108
 109 /*
 110  * Handle vendor specific USB requests
 111  */
 112
 113 #define WDR_TIMEOUT 5000 /* default urb timeout */
 114
 115 /*
 116  * Later day 2.6.0-test kernels have new baud rates like B230400 which
 117  * we do not know how to support. We ignore them for the moment.
 118  */
 119 static int mct_u232_calculate_baud_rate(struct usb_serial *serial,
 120                                         speed_t value, speed_t *result)
 121 {
 122         *result = value;
 123
 124         if (le16_to_cpu(serial->dev->descriptor.idProduct) == MCT_U232_SITECOM_PID
 125                 || le16_to_cpu(serial->dev->descriptor.idProduct) == MCT_U232_BELKIN_F5U109_PID) {
 126                 switch (value) {
 127                 case 300:
 128                         return 0x01;
 129                 case 600:
 130                         return 0x02; /* this one not tested */
 131                 case 1200:
 132                         return 0x03;
 133                 case 2400:
 134                         return 0x04;
 135                 case 4800:
 136                         return 0x06;
 137                 case 9600:
 138                         return 0x08;
 139                 case 19200:
 140                         return 0x09;
 141                 case 38400:
 142                         return 0x0a;
 143                 case 57600:
 144                         return 0x0b;
 145                 case 115200:
 146                         return 0x0c;
 147                 default:
 148                         *result = 9600;
 149                         return 0x08;
 150                 }
 151         } else {
 152                 /* FIXME: Can we use any divider - should we do
 153                    divider = 115200/value;
 154                    real baud = 115200/divider */
 155                 switch (value) {
 156                 case 300: break;
 157                 case 600: break;
 158                 case 1200: break;
 159                 case 2400: break;
 160                 case 4800: break;
 161                 case 9600: break;
 162                 case 19200: break;
 163                 case 38400: break;
 164                 case 57600: break;
 165                 case 115200: break;
 166                 default:
 167                         value = 9600;
 168                         *result = 9600;
 169                 }
 170                 return 115200/value;
 171         }
 172 }
 173
 174 static int mct_u232_set_baud_rate(struct tty_struct *tty,
 175         struct usb_serial *serial, struct usb_serial_port *port, speed_t value)
 176 {
 177         unsigned int divisor;
 178         int rc;
 179         unsigned char *buf;
 180         unsigned char cts_enable_byte = 0;
 181         speed_t speed;
 182
 183         buf = kmalloc(MCT_U232_MAX_SIZE, GFP_KERNEL);
 184         if (buf == NULL)
 185                 return -ENOMEM;
 186
 187         divisor = mct_u232_calculate_baud_rate(serial, value, &speed);
 188         put_unaligned_le32(divisor, buf);
 189         rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
 190                                 MCT_U232_SET_BAUD_RATE_REQUEST,
 191                                 MCT_U232_SET_REQUEST_TYPE,
 192                                 0, 0, buf, MCT_U232_SET_BAUD_RATE_SIZE,
 193                                 WDR_TIMEOUT);
 194         if (rc < 0)     /*FIXME: What value speed results */
 195                 dev_err(&port->dev, "Set BAUD RATE %d failed (error = %d)\n",
 196                         value, rc);
 197         else
 198                 tty_encode_baud_rate(tty, speed, speed);
 199         dev_dbg(&port->dev, "set_baud_rate: value: 0x%x, divisor: 0x%x\n", value, divisor);
 200
 201         /* Mimic the MCT-supplied Windows driver (version 1.21P.0104), which
 202            always sends two extra USB 'device request' messages after the
 203            'baud rate change' message.  The actual functionality of the
 204            request codes in these messages is not fully understood but these
 205            particular codes are never seen in any operation besides a baud
 206            rate change.  Both of these messages send a single byte of data.
 207            In the first message, the value of this byte is always zero.
 208
 209            The second message has been determined experimentally to control
 210            whether data will be transmitted to a device which is not asserting
 211            the 'CTS' signal.  If the second message's data byte is zero, data
 212            will be transmitted even if 'CTS' is not asserted (i.e. no hardware
 213            flow control).  if the second message's data byte is nonzero (a
 214            value of 1 is used by this driver), data will not be transmitted to
 215            a device which is not asserting 'CTS'.
 216         */
 217
 218         buf[0] = 0;
 219         rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
 220                                 MCT_U232_SET_UNKNOWN1_REQUEST,
 221                                 MCT_U232_SET_REQUEST_TYPE,
 222                                 0, 0, buf, MCT_U232_SET_UNKNOWN1_SIZE,
 223                                 WDR_TIMEOUT);
 224         if (rc < 0)
 225                 dev_err(&port->dev, "Sending USB device request code %d "
 226                         "failed (error = %d)\n", MCT_U232_SET_UNKNOWN1_REQUEST,
 227                         rc);
 228
 229         if (port && C_CRTSCTS(tty))
 230            cts_enable_byte = 1;
 231
 232         dev_dbg(&port->dev, "set_baud_rate: send second control message, data = %02X\n",
 233                 cts_enable_byte);
 234         buf[0] = cts_enable_byte;
 235         rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
 236                         MCT_U232_SET_CTS_REQUEST,
 237                         MCT_U232_SET_REQUEST_TYPE,
 238                         0, 0, buf, MCT_U232_SET_CTS_SIZE,
 239                         WDR_TIMEOUT);
 240         if (rc < 0)
 241                 dev_err(&port->dev, "Sending USB device request code %d "
 242                         "failed (error = %d)\n", MCT_U232_SET_CTS_REQUEST, rc);
 243
 244         kfree(buf);
 245         return rc;
 246 } /* mct_u232_set_baud_rate */
 247
 248 static int mct_u232_set_line_ctrl(struct usb_serial_port *port,
 249                                   unsigned char lcr)
 250 {
 251         int rc;
 252         unsigned char *buf;
 253
 254         buf = kmalloc(MCT_U232_MAX_SIZE, GFP_KERNEL);
 255         if (buf == NULL)
 256                 return -ENOMEM;
 257
 258         buf[0] = lcr;
 259         rc = usb_control_msg(port->serial->dev, usb_sndctrlpipe(port->serial->dev, 0),
 260                         MCT_U232_SET_LINE_CTRL_REQUEST,
 261                         MCT_U232_SET_REQUEST_TYPE,
 262                         0, 0, buf, MCT_U232_SET_LINE_CTRL_SIZE,
 263                         WDR_TIMEOUT);
 264         if (rc < 0)
 265                 dev_err(&port->dev, "Set LINE CTRL 0x%x failed (error = %d)\n", lcr, rc);
 266         dev_dbg(&port->dev, "set_line_ctrl: 0x%x\n", lcr);
 267         kfree(buf);
 268         return rc;
 269 } /* mct_u232_set_line_ctrl */
 270
 271 static int mct_u232_set_modem_ctrl(struct usb_serial_port *port,
 272                                    unsigned int control_state)
 273 {
 274         int rc;
 275         unsigned char mcr;
 276         unsigned char *buf;
 277
 278         buf = kmalloc(MCT_U232_MAX_SIZE, GFP_KERNEL);
 279         if (buf == NULL)
 280                 return -ENOMEM;
 281
 282         mcr = MCT_U232_MCR_NONE;
 283         if (control_state & TIOCM_DTR)
 284                 mcr |= MCT_U232_MCR_DTR;
 285         if (control_state & TIOCM_RTS)
 286                 mcr |= MCT_U232_MCR_RTS;
 287
 288         buf[0] = mcr;
 289         rc = usb_control_msg(port->serial->dev, usb_sndctrlpipe(port->serial->dev, 0),
 290                         MCT_U232_SET_MODEM_CTRL_REQUEST,
 291                         MCT_U232_SET_REQUEST_TYPE,
 292                         0, 0, buf, MCT_U232_SET_MODEM_CTRL_SIZE,
 293                         WDR_TIMEOUT);
 294         kfree(buf);
 295
 296         dev_dbg(&port->dev, "set_modem_ctrl: state=0x%x ==> mcr=0x%x\n", control_state, mcr);
 297
 298         if (rc < 0) {
 299                 dev_err(&port->dev, "Set MODEM CTRL 0x%x failed (error = %d)\n", mcr, rc);
 300                 return rc;
 301         }
 302         return 0;
 303 } /* mct_u232_set_modem_ctrl */
 304
 305 static int mct_u232_get_modem_stat(struct usb_serial_port *port,
 306                                    unsigned char *msr)
 307 {
 308         int rc;
 309         unsigned char *buf;
 310
 311         buf = kmalloc(MCT_U232_MAX_SIZE, GFP_KERNEL);
 312         if (buf == NULL) {
 313                 *msr = 0;
 314                 return -ENOMEM;
 315         }
 316         rc = usb_control_msg(port->serial->dev, usb_rcvctrlpipe(port->serial->dev, 0),
 317                         MCT_U232_GET_MODEM_STAT_REQUEST,
 318                         MCT_U232_GET_REQUEST_TYPE,
 319                         0, 0, buf, MCT_U232_GET_MODEM_STAT_SIZE,
 320                         WDR_TIMEOUT);
 321         if (rc < MCT_U232_GET_MODEM_STAT_SIZE) {
 322                 dev_err(&port->dev, "Get MODEM STATus failed (error = %d)\n", rc);
 323
 324                 if (rc >= 0)
 325                         rc = -EIO;
 326
 327                 *msr = 0;
 328         } else {
 329                 *msr = buf[0];
 330         }
 331         dev_dbg(&port->dev, "get_modem_stat: 0x%x\n", *msr);
 332         kfree(buf);
 333         return rc;
 334 } /* mct_u232_get_modem_stat */
 335
 336 static void mct_u232_msr_to_icount(struct async_icount *icount,
 337                                                 unsigned char msr)
 338 {
 339         /* Translate Control Line states */
 340         if (msr & MCT_U232_MSR_DDSR)
 341                 icount->dsr++;
 342         if (msr & MCT_U232_MSR_DCTS)
 343                 icount->cts++;
 344         if (msr & MCT_U232_MSR_DRI)
 345                 icount->rng++;
 346         if (msr & MCT_U232_MSR_DCD)
 347                 icount->dcd++;
 348 } /* mct_u232_msr_to_icount */
 349
 350 static void mct_u232_msr_to_state(struct usb_serial_port *port,
 351                                   unsigned int *control_state, unsigned char msr)
 352 {
 353         /* Translate Control Line states */
 354         if (msr & MCT_U232_MSR_DSR)
 355                 *control_state |=  TIOCM_DSR;
 356         else
 357                 *control_state &= ~TIOCM_DSR;
 358         if (msr & MCT_U232_MSR_CTS)
 359                 *control_state |=  TIOCM_CTS;
 360         else
 361                 *control_state &= ~TIOCM_CTS;
 362         if (msr & MCT_U232_MSR_RI)
 363                 *control_state |=  TIOCM_RI;
 364         else
 365                 *control_state &= ~TIOCM_RI;
 366         if (msr & MCT_U232_MSR_CD)
 367                 *control_state |=  TIOCM_CD;
 368         else
 369                 *control_state &= ~TIOCM_CD;
 370         dev_dbg(&port->dev, "msr_to_state: msr=0x%x ==> state=0x%x\n", msr, *control_state);
 371 } /* mct_u232_msr_to_state */
 372
 373 /*
 374  * Driver's tty interface functions
 375  */
 376
 377 static int mct_u232_port_probe(struct usb_serial_port *port)
 378 {
 379         struct usb_serial *serial = port->serial;
 380         struct mct_u232_private *priv;
 381
 382         /* check first to simplify error handling */
 383         if (!serial->port[1] || !serial->port[1]->interrupt_in_urb) {
 384                 dev_err(&port->dev, "expected endpoint missing\n");
 385                 return -ENODEV;
 386         }
 387
 388         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 389         if (!priv)
 390                 return -ENOMEM;
 391
 392         /* Use second interrupt-in endpoint for reading. */
 393         priv->read_urb = serial->port[1]->interrupt_in_urb;
 394         priv->read_urb->context = port;
 395
 396         spin_lock_init(&priv->lock);
 397
 398         usb_set_serial_port_data(port, priv);
 399
 400         return 0;
 401 }
 402
 403 static void mct_u232_port_remove(struct usb_serial_port *port)
 404 {
 405         struct mct_u232_private *priv;
 406
 407         priv = usb_get_serial_port_data(port);
 408         kfree(priv);
 409 }
 410
 411 static int  mct_u232_open(struct tty_struct *tty, struct usb_serial_port *port)
 412 {
 413         struct usb_serial *serial = port->serial;
 414         struct mct_u232_private *priv = usb_get_serial_port_data(port);
 415         int retval = 0;
 416         unsigned int control_state;
 417         unsigned long flags;
 418         unsigned char last_lcr;
 419         unsigned char last_msr;
 420
 421         /* Compensate for a hardware bug: although the Sitecom U232-P25
 422          * device reports a maximum output packet size of 32 bytes,
 423          * it seems to be able to accept only 16 bytes (and that's what
 424          * SniffUSB says too...)
 425          */
 426         if (le16_to_cpu(serial->dev->descriptor.idProduct)
 427                                                 == MCT_U232_SITECOM_PID)
 428                 port->bulk_out_size = 16;
 429
 430         /* Do a defined restart: the normal serial device seems to
 431          * always turn on DTR and RTS here, so do the same. I'm not
 432          * sure if this is really necessary. But it should not harm
 433          * either.
 434          */
 435         spin_lock_irqsave(&priv->lock, flags);
 436         if (tty && C_BAUD(tty))
 437                 priv->control_state = TIOCM_DTR | TIOCM_RTS;
 438         else
 439                 priv->control_state = 0;
 440
 441         priv->last_lcr = (MCT_U232_DATA_BITS_8 |
 442                           MCT_U232_PARITY_NONE |
 443                           MCT_U232_STOP_BITS_1);
 444         control_state = priv->control_state;
 445         last_lcr = priv->last_lcr;
 446         spin_unlock_irqrestore(&priv->lock, flags);
 447         mct_u232_set_modem_ctrl(port, control_state);
 448         mct_u232_set_line_ctrl(port, last_lcr);
 449
 450         /* Read modem status and update control state */
 451         mct_u232_get_modem_stat(port, &last_msr);
 452         spin_lock_irqsave(&priv->lock, flags);
 453         priv->last_msr = last_msr;
 454         mct_u232_msr_to_state(port, &priv->control_state, priv->last_msr);
 455         spin_unlock_irqrestore(&priv->lock, flags);
 456
 457         retval = usb_submit_urb(priv->read_urb, GFP_KERNEL);
 458         if (retval) {
 459                 dev_err(&port->dev,
 460                         "usb_submit_urb(read) failed pipe 0x%x err %d\n",
 461                         port->read_urb->pipe, retval);
 462                 goto error;
 463         }
 464
 465         retval = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 466         if (retval) {
 467                 usb_kill_urb(priv->read_urb);
 468                 dev_err(&port->dev,
 469                         "usb_submit_urb(read int) failed pipe 0x%x err %d",
 470                         port->interrupt_in_urb->pipe, retval);
 471                 goto error;
 472         }
 473         return 0;
 474
 475 error:
 476         return retval;
 477 } /* mct_u232_open */
 478
 479 static void mct_u232_dtr_rts(struct usb_serial_port *port, int on)
 480 {
 481         unsigned int control_state;
 482         struct mct_u232_private *priv = usb_get_serial_port_data(port);
 483
 484         spin_lock_irq(&priv->lock);
 485         if (on)
 486                 priv->control_state |= TIOCM_DTR | TIOCM_RTS;
 487         else
 488                 priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
 489         control_state = priv->control_state;
 490         spin_unlock_irq(&priv->lock);
 491
 492         mct_u232_set_modem_ctrl(port, control_state);
 493 }
 494
 495 static void mct_u232_close(struct usb_serial_port *port)
 496 {
 497         struct mct_u232_private *priv = usb_get_serial_port_data(port);
 498
 499         usb_kill_urb(priv->read_urb);
 500         usb_kill_urb(port->interrupt_in_urb);
 501
 502         usb_serial_generic_close(port);
 503 } /* mct_u232_close */
 504
 505
 506 static void mct_u232_read_int_callback(struct urb *urb)
 507 {
 508         struct usb_serial_port *port = urb->context;
 509         struct mct_u232_private *priv = usb_get_serial_port_data(port);
 510         unsigned char *data = urb->transfer_buffer;
 511         int retval;
 512         int status = urb->status;
 513         unsigned long flags;
 514
 515         switch (status) {
 516         case 0:
 517                 /* success */
 518                 break;
 519         case -ECONNRESET:
 520         case -ENOENT:
 521         case -ESHUTDOWN:
 522                 /* this urb is terminated, clean up */
 523                 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
 524                         __func__, status);
 525                 return;
 526         default:
 527                 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
 528                         __func__, status);
 529                 goto exit;
 530         }
 531
 532         usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
 533
 534         /*
 535          * Work-a-round: handle the 'usual' bulk-in pipe here
 536          */
 537         if (urb->transfer_buffer_length > 2) {
 538                 if (urb->actual_length) {
 539                         tty_insert_flip_string(&port->port, data,
 540                                         urb->actual_length);
 541                         tty_flip_buffer_push(&port->port);
 542                 }
 543                 goto exit;
 544         }
 545
 546         /*
 547          * The interrupt-in pipe signals exceptional conditions (modem line
 548          * signal changes and errors). data[0] holds MSR, data[1] holds LSR.
 549          */
 550         spin_lock_irqsave(&priv->lock, flags);
 551         priv->last_msr = data[MCT_U232_MSR_INDEX];
 552
 553         /* Record Control Line states */
 554         mct_u232_msr_to_state(port, &priv->control_state, priv->last_msr);
 555
 556         mct_u232_msr_to_icount(&port->icount, priv->last_msr);
 557
 558 #if 0
 559         /* Not yet handled. See belkin_sa.c for further information */
 560         /* Now to report any errors */
 561         priv->last_lsr = data[MCT_U232_LSR_INDEX];
 562         /*
 563          * fill in the flip buffer here, but I do not know the relation
 564          * to the current/next receive buffer or characters.  I need
 565          * to look in to this before committing any code.
 566          */
 567         if (priv->last_lsr & MCT_U232_LSR_ERR) {
 568                 tty = tty_port_tty_get(&port->port);
 569                 /* Overrun Error */
 570                 if (priv->last_lsr & MCT_U232_LSR_OE) {
 571                 }
 572                 /* Parity Error */
 573                 if (priv->last_lsr & MCT_U232_LSR_PE) {
 574                 }
 575                 /* Framing Error */
 576                 if (priv->last_lsr & MCT_U232_LSR_FE) {
 577                 }
 578                 /* Break Indicator */
 579                 if (priv->last_lsr & MCT_U232_LSR_BI) {
 580                 }
 581                 tty_kref_put(tty);
 582         }
 583 #endif
 584         wake_up_interruptible(&port->port.delta_msr_wait);
 585         spin_unlock_irqrestore(&priv->lock, flags);
 586 exit:
 587         retval = usb_submit_urb(urb, GFP_ATOMIC);
 588         if (retval)
 589                 dev_err(&port->dev,
 590                         "%s - usb_submit_urb failed with result %d\n",
 591                         __func__, retval);
 592 } /* mct_u232_read_int_callback */
 593
 594 static void mct_u232_set_termios(struct tty_struct *tty,
 595                                  struct usb_serial_port *port,
 596                                  struct ktermios *old_termios)
 597 {
 598         struct usb_serial *serial = port->serial;
 599         struct mct_u232_private *priv = usb_get_serial_port_data(port);
 600         struct ktermios *termios = &tty->termios;
 601         unsigned int cflag = termios->c_cflag;
 602         unsigned int old_cflag = old_termios->c_cflag;
 603         unsigned long flags;
 604         unsigned int control_state;
 605         unsigned char last_lcr;
 606
 607         /* get a local copy of the current port settings */
 608         spin_lock_irqsave(&priv->lock, flags);
 609         control_state = priv->control_state;
 610         spin_unlock_irqrestore(&priv->lock, flags);
 611         last_lcr = 0;
 612
 613         /*
 614          * Update baud rate.
 615          * Do not attempt to cache old rates and skip settings,
 616          * disconnects screw such tricks up completely.
 617          * Premature optimization is the root of all evil.
 618          */
 619
 620         /* reassert DTR and RTS on transition from B0 */
 621         if ((old_cflag & CBAUD) == B0) {
 622                 dev_dbg(&port->dev, "%s: baud was B0\n", __func__);
 623                 control_state |= TIOCM_DTR | TIOCM_RTS;
 624                 mct_u232_set_modem_ctrl(port, control_state);
 625         }
 626
 627         mct_u232_set_baud_rate(tty, serial, port, tty_get_baud_rate(tty));
 628
 629         if ((cflag & CBAUD) == B0) {
 630                 dev_dbg(&port->dev, "%s: baud is B0\n", __func__);
 631                 /* Drop RTS and DTR */
 632                 control_state &= ~(TIOCM_DTR | TIOCM_RTS);
 633                 mct_u232_set_modem_ctrl(port, control_state);
 634         }
 635
 636         /*
 637          * Update line control register (LCR)
 638          */
 639
 640         /* set the parity */
 641         if (cflag & PARENB)
 642                 last_lcr |= (cflag & PARODD) ?
 643                         MCT_U232_PARITY_ODD : MCT_U232_PARITY_EVEN;
 644         else
 645                 last_lcr |= MCT_U232_PARITY_NONE;
 646
 647         /* set the number of data bits */
 648         switch (cflag & CSIZE) {
 649         case CS5:
 650                 last_lcr |= MCT_U232_DATA_BITS_5; break;
 651         case CS6:
 652                 last_lcr |= MCT_U232_DATA_BITS_6; break;
 653         case CS7:
 654                 last_lcr |= MCT_U232_DATA_BITS_7; break;
 655         case CS8:
 656                 last_lcr |= MCT_U232_DATA_BITS_8; break;
 657         default:
 658                 dev_err(&port->dev,
 659                         "CSIZE was not CS5-CS8, using default of 8\n");
 660                 last_lcr |= MCT_U232_DATA_BITS_8;
 661                 break;
 662         }
 663
 664         termios->c_cflag &= ~CMSPAR;
 665
 666         /* set the number of stop bits */
 667         last_lcr |= (cflag & CSTOPB) ?
 668                 MCT_U232_STOP_BITS_2 : MCT_U232_STOP_BITS_1;
 669
 670         mct_u232_set_line_ctrl(port, last_lcr);
 671
 672         /* save off the modified port settings */
 673         spin_lock_irqsave(&priv->lock, flags);
 674         priv->control_state = control_state;
 675         priv->last_lcr = last_lcr;
 676         spin_unlock_irqrestore(&priv->lock, flags);
 677 } /* mct_u232_set_termios */
 678
 679 static void mct_u232_break_ctl(struct tty_struct *tty, int break_state)
 680 {
 681         struct usb_serial_port *port = tty->driver_data;
 682         struct mct_u232_private *priv = usb_get_serial_port_data(port);
 683         unsigned char lcr;
 684         unsigned long flags;
 685
 686         spin_lock_irqsave(&priv->lock, flags);
 687         lcr = priv->last_lcr;
 688
 689         if (break_state)
 690                 lcr |= MCT_U232_SET_BREAK;
 691         spin_unlock_irqrestore(&priv->lock, flags);
 692
 693         mct_u232_set_line_ctrl(port, lcr);
 694 } /* mct_u232_break_ctl */
 695
 696
 697 static int mct_u232_tiocmget(struct tty_struct *tty)
 698 {
 699         struct usb_serial_port *port = tty->driver_data;
 700         struct mct_u232_private *priv = usb_get_serial_port_data(port);
 701         unsigned int control_state;
 702         unsigned long flags;
 703
 704         spin_lock_irqsave(&priv->lock, flags);
 705         control_state = priv->control_state;
 706         spin_unlock_irqrestore(&priv->lock, flags);
 707
 708         return control_state;
 709 }
 710
 711 static int mct_u232_tiocmset(struct tty_struct *tty,
 712                               unsigned int set, unsigned int clear)
 713 {
 714         struct usb_serial_port *port = tty->driver_data;
 715         struct mct_u232_private *priv = usb_get_serial_port_data(port);
 716         unsigned int control_state;
 717         unsigned long flags;
 718
 719         spin_lock_irqsave(&priv->lock, flags);
 720         control_state = priv->control_state;
 721
 722         if (set & TIOCM_RTS)
 723                 control_state |= TIOCM_RTS;
 724         if (set & TIOCM_DTR)
 725                 control_state |= TIOCM_DTR;
 726         if (clear & TIOCM_RTS)
 727                 control_state &= ~TIOCM_RTS;
 728         if (clear & TIOCM_DTR)
 729                 control_state &= ~TIOCM_DTR;
 730
 731         priv->control_state = control_state;
 732         spin_unlock_irqrestore(&priv->lock, flags);
 733         return mct_u232_set_modem_ctrl(port, control_state);
 734 }
 735
 736 static void mct_u232_throttle(struct tty_struct *tty)
 737 {
 738         struct usb_serial_port *port = tty->driver_data;
 739         struct mct_u232_private *priv = usb_get_serial_port_data(port);
 740         unsigned int control_state;
 741
 742         spin_lock_irq(&priv->lock);
 743         priv->rx_flags |= THROTTLED;
 744         if (C_CRTSCTS(tty)) {
 745                 priv->control_state &= ~TIOCM_RTS;
 746                 control_state = priv->control_state;
 747                 spin_unlock_irq(&priv->lock);
 748                 mct_u232_set_modem_ctrl(port, control_state);
 749         } else {
 750                 spin_unlock_irq(&priv->lock);
 751         }
 752 }
 753
 754 static void mct_u232_unthrottle(struct tty_struct *tty)
 755 {
 756         struct usb_serial_port *port = tty->driver_data;
 757         struct mct_u232_private *priv = usb_get_serial_port_data(port);
 758         unsigned int control_state;
 759
 760         spin_lock_irq(&priv->lock);
 761         if ((priv->rx_flags & THROTTLED) && C_CRTSCTS(tty)) {
 762                 priv->rx_flags &= ~THROTTLED;
 763                 priv->control_state |= TIOCM_RTS;
 764                 control_state = priv->control_state;
 765                 spin_unlock_irq(&priv->lock);
 766                 mct_u232_set_modem_ctrl(port, control_state);
 767         } else {
 768                 spin_unlock_irq(&priv->lock);
 769         }
 770 }
 771
 772 module_usb_serial_driver(serial_drivers, id_table);
 773
 774 MODULE_AUTHOR(DRIVER_AUTHOR);
 775 MODULE_DESCRIPTION(DRIVER_DESC);
 776 MODULE_LICENSE("GPL");