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 int  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 int 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         return 0;
 411 }
 412
 413 static int  mct_u232_open(struct tty_struct *tty, struct usb_serial_port *port)
 414 {
 415         struct usb_serial *serial = port->serial;
 416         struct mct_u232_private *priv = usb_get_serial_port_data(port);
 417         int retval = 0;
 418         unsigned int control_state;
 419         unsigned long flags;
 420         unsigned char last_lcr;
 421         unsigned char last_msr;
 422
 423         /* Compensate for a hardware bug: although the Sitecom U232-P25
 424          * device reports a maximum output packet size of 32 bytes,
 425          * it seems to be able to accept only 16 bytes (and that's what
 426          * SniffUSB says too...)
 427          */
 428         if (le16_to_cpu(serial->dev->descriptor.idProduct)
 429                                                 == MCT_U232_SITECOM_PID)
 430                 port->bulk_out_size = 16;
 431
 432         /* Do a defined restart: the normal serial device seems to
 433          * always turn on DTR and RTS here, so do the same. I'm not
 434          * sure if this is really necessary. But it should not harm
 435          * either.
 436          */
 437         spin_lock_irqsave(&priv->lock, flags);
 438         if (tty && C_BAUD(tty))
 439                 priv->control_state = TIOCM_DTR | TIOCM_RTS;
 440         else
 441                 priv->control_state = 0;
 442
 443         priv->last_lcr = (MCT_U232_DATA_BITS_8 |
 444                           MCT_U232_PARITY_NONE |
 445                           MCT_U232_STOP_BITS_1);
 446         control_state = priv->control_state;
 447         last_lcr = priv->last_lcr;
 448         spin_unlock_irqrestore(&priv->lock, flags);
 449         mct_u232_set_modem_ctrl(port, control_state);
 450         mct_u232_set_line_ctrl(port, last_lcr);
 451
 452         /* Read modem status and update control state */
 453         mct_u232_get_modem_stat(port, &last_msr);
 454         spin_lock_irqsave(&priv->lock, flags);
 455         priv->last_msr = last_msr;
 456         mct_u232_msr_to_state(port, &priv->control_state, priv->last_msr);
 457         spin_unlock_irqrestore(&priv->lock, flags);
 458
 459         retval = usb_submit_urb(priv->read_urb, GFP_KERNEL);
 460         if (retval) {
 461                 dev_err(&port->dev,
 462                         "usb_submit_urb(read) failed pipe 0x%x err %d\n",
 463                         port->read_urb->pipe, retval);
 464                 goto error;
 465         }
 466
 467         retval = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 468         if (retval) {
 469                 usb_kill_urb(priv->read_urb);
 470                 dev_err(&port->dev,
 471                         "usb_submit_urb(read int) failed pipe 0x%x err %d",
 472                         port->interrupt_in_urb->pipe, retval);
 473                 goto error;
 474         }
 475         return 0;
 476
 477 error:
 478         return retval;
 479 } /* mct_u232_open */
 480
 481 static void mct_u232_dtr_rts(struct usb_serial_port *port, int on)
 482 {
 483         unsigned int control_state;
 484         struct mct_u232_private *priv = usb_get_serial_port_data(port);
 485
 486         spin_lock_irq(&priv->lock);
 487         if (on)
 488                 priv->control_state |= TIOCM_DTR | TIOCM_RTS;
 489         else
 490                 priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
 491         control_state = priv->control_state;
 492         spin_unlock_irq(&priv->lock);
 493
 494         mct_u232_set_modem_ctrl(port, control_state);
 495 }
 496
 497 static void mct_u232_close(struct usb_serial_port *port)
 498 {
 499         struct mct_u232_private *priv = usb_get_serial_port_data(port);
 500
 501         usb_kill_urb(priv->read_urb);
 502         usb_kill_urb(port->interrupt_in_urb);
 503
 504         usb_serial_generic_close(port);
 505 } /* mct_u232_close */
 506
 507
 508 static void mct_u232_read_int_callback(struct urb *urb)
 509 {
 510         struct usb_serial_port *port = urb->context;
 511         struct mct_u232_private *priv = usb_get_serial_port_data(port);
 512         unsigned char *data = urb->transfer_buffer;
 513         int retval;
 514         int status = urb->status;
 515         unsigned long flags;
 516
 517         switch (status) {
 518         case 0:
 519                 /* success */
 520                 break;
 521         case -ECONNRESET:
 522         case -ENOENT:
 523         case -ESHUTDOWN:
 524                 /* this urb is terminated, clean up */
 525                 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
 526                         __func__, status);
 527                 return;
 528         default:
 529                 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
 530                         __func__, status);
 531                 goto exit;
 532         }
 533
 534         usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
 535
 536         /*
 537          * Work-a-round: handle the 'usual' bulk-in pipe here
 538          */
 539         if (urb->transfer_buffer_length > 2) {
 540                 if (urb->actual_length) {
 541                         tty_insert_flip_string(&port->port, data,
 542                                         urb->actual_length);
 543                         tty_flip_buffer_push(&port->port);
 544                 }
 545                 goto exit;
 546         }
 547
 548         /*
 549          * The interrupt-in pipe signals exceptional conditions (modem line
 550          * signal changes and errors). data[0] holds MSR, data[1] holds LSR.
 551          */
 552         spin_lock_irqsave(&priv->lock, flags);
 553         priv->last_msr = data[MCT_U232_MSR_INDEX];
 554
 555         /* Record Control Line states */
 556         mct_u232_msr_to_state(port, &priv->control_state, priv->last_msr);
 557
 558         mct_u232_msr_to_icount(&port->icount, priv->last_msr);
 559
 560 #if 0
 561         /* Not yet handled. See belkin_sa.c for further information */
 562         /* Now to report any errors */
 563         priv->last_lsr = data[MCT_U232_LSR_INDEX];
 564         /*
 565          * fill in the flip buffer here, but I do not know the relation
 566          * to the current/next receive buffer or characters.  I need
 567          * to look in to this before committing any code.
 568          */
 569         if (priv->last_lsr & MCT_U232_LSR_ERR) {
 570                 tty = tty_port_tty_get(&port->port);
 571                 /* Overrun Error */
 572                 if (priv->last_lsr & MCT_U232_LSR_OE) {
 573                 }
 574                 /* Parity Error */
 575                 if (priv->last_lsr & MCT_U232_LSR_PE) {
 576                 }
 577                 /* Framing Error */
 578                 if (priv->last_lsr & MCT_U232_LSR_FE) {
 579                 }
 580                 /* Break Indicator */
 581                 if (priv->last_lsr & MCT_U232_LSR_BI) {
 582                 }
 583                 tty_kref_put(tty);
 584         }
 585 #endif
 586         wake_up_interruptible(&port->port.delta_msr_wait);
 587         spin_unlock_irqrestore(&priv->lock, flags);
 588 exit:
 589         retval = usb_submit_urb(urb, GFP_ATOMIC);
 590         if (retval)
 591                 dev_err(&port->dev,
 592                         "%s - usb_submit_urb failed with result %d\n",
 593                         __func__, retval);
 594 } /* mct_u232_read_int_callback */
 595
 596 static void mct_u232_set_termios(struct tty_struct *tty,
 597                                  struct usb_serial_port *port,
 598                                  struct ktermios *old_termios)
 599 {
 600         struct usb_serial *serial = port->serial;
 601         struct mct_u232_private *priv = usb_get_serial_port_data(port);
 602         struct ktermios *termios = &tty->termios;
 603         unsigned int cflag = termios->c_cflag;
 604         unsigned int old_cflag = old_termios->c_cflag;
 605         unsigned long flags;
 606         unsigned int control_state;
 607         unsigned char last_lcr;
 608
 609         /* get a local copy of the current port settings */
 610         spin_lock_irqsave(&priv->lock, flags);
 611         control_state = priv->control_state;
 612         spin_unlock_irqrestore(&priv->lock, flags);
 613         last_lcr = 0;
 614
 615         /*
 616          * Update baud rate.
 617          * Do not attempt to cache old rates and skip settings,
 618          * disconnects screw such tricks up completely.
 619          * Premature optimization is the root of all evil.
 620          */
 621
 622         /* reassert DTR and RTS on transition from B0 */
 623         if ((old_cflag & CBAUD) == B0) {
 624                 dev_dbg(&port->dev, "%s: baud was B0\n", __func__);
 625                 control_state |= TIOCM_DTR | TIOCM_RTS;
 626                 mct_u232_set_modem_ctrl(port, control_state);
 627         }
 628
 629         mct_u232_set_baud_rate(tty, serial, port, tty_get_baud_rate(tty));
 630
 631         if ((cflag & CBAUD) == B0) {
 632                 dev_dbg(&port->dev, "%s: baud is B0\n", __func__);
 633                 /* Drop RTS and DTR */
 634                 control_state &= ~(TIOCM_DTR | TIOCM_RTS);
 635                 mct_u232_set_modem_ctrl(port, control_state);
 636         }
 637
 638         /*
 639          * Update line control register (LCR)
 640          */
 641
 642         /* set the parity */
 643         if (cflag & PARENB)
 644                 last_lcr |= (cflag & PARODD) ?
 645                         MCT_U232_PARITY_ODD : MCT_U232_PARITY_EVEN;
 646         else
 647                 last_lcr |= MCT_U232_PARITY_NONE;
 648
 649         /* set the number of data bits */
 650         switch (cflag & CSIZE) {
 651         case CS5:
 652                 last_lcr |= MCT_U232_DATA_BITS_5; break;
 653         case CS6:
 654                 last_lcr |= MCT_U232_DATA_BITS_6; break;
 655         case CS7:
 656                 last_lcr |= MCT_U232_DATA_BITS_7; break;
 657         case CS8:
 658                 last_lcr |= MCT_U232_DATA_BITS_8; break;
 659         default:
 660                 dev_err(&port->dev,
 661                         "CSIZE was not CS5-CS8, using default of 8\n");
 662                 last_lcr |= MCT_U232_DATA_BITS_8;
 663                 break;
 664         }
 665
 666         termios->c_cflag &= ~CMSPAR;
 667
 668         /* set the number of stop bits */
 669         last_lcr |= (cflag & CSTOPB) ?
 670                 MCT_U232_STOP_BITS_2 : MCT_U232_STOP_BITS_1;
 671
 672         mct_u232_set_line_ctrl(port, last_lcr);
 673
 674         /* save off the modified port settings */
 675         spin_lock_irqsave(&priv->lock, flags);
 676         priv->control_state = control_state;
 677         priv->last_lcr = last_lcr;
 678         spin_unlock_irqrestore(&priv->lock, flags);
 679 } /* mct_u232_set_termios */
 680
 681 static void mct_u232_break_ctl(struct tty_struct *tty, int break_state)
 682 {
 683         struct usb_serial_port *port = tty->driver_data;
 684         struct mct_u232_private *priv = usb_get_serial_port_data(port);
 685         unsigned char lcr;
 686         unsigned long flags;
 687
 688         spin_lock_irqsave(&priv->lock, flags);
 689         lcr = priv->last_lcr;
 690
 691         if (break_state)
 692                 lcr |= MCT_U232_SET_BREAK;
 693         spin_unlock_irqrestore(&priv->lock, flags);
 694
 695         mct_u232_set_line_ctrl(port, lcr);
 696 } /* mct_u232_break_ctl */
 697
 698
 699 static int mct_u232_tiocmget(struct tty_struct *tty)
 700 {
 701         struct usb_serial_port *port = tty->driver_data;
 702         struct mct_u232_private *priv = usb_get_serial_port_data(port);
 703         unsigned int control_state;
 704         unsigned long flags;
 705
 706         spin_lock_irqsave(&priv->lock, flags);
 707         control_state = priv->control_state;
 708         spin_unlock_irqrestore(&priv->lock, flags);
 709
 710         return control_state;
 711 }
 712
 713 static int mct_u232_tiocmset(struct tty_struct *tty,
 714                               unsigned int set, unsigned int clear)
 715 {
 716         struct usb_serial_port *port = tty->driver_data;
 717         struct mct_u232_private *priv = usb_get_serial_port_data(port);
 718         unsigned int control_state;
 719         unsigned long flags;
 720
 721         spin_lock_irqsave(&priv->lock, flags);
 722         control_state = priv->control_state;
 723
 724         if (set & TIOCM_RTS)
 725                 control_state |= TIOCM_RTS;
 726         if (set & TIOCM_DTR)
 727                 control_state |= TIOCM_DTR;
 728         if (clear & TIOCM_RTS)
 729                 control_state &= ~TIOCM_RTS;
 730         if (clear & TIOCM_DTR)
 731                 control_state &= ~TIOCM_DTR;
 732
 733         priv->control_state = control_state;
 734         spin_unlock_irqrestore(&priv->lock, flags);
 735         return mct_u232_set_modem_ctrl(port, control_state);
 736 }
 737
 738 static void mct_u232_throttle(struct tty_struct *tty)
 739 {
 740         struct usb_serial_port *port = tty->driver_data;
 741         struct mct_u232_private *priv = usb_get_serial_port_data(port);
 742         unsigned int control_state;
 743
 744         spin_lock_irq(&priv->lock);
 745         priv->rx_flags |= THROTTLED;
 746         if (C_CRTSCTS(tty)) {
 747                 priv->control_state &= ~TIOCM_RTS;
 748                 control_state = priv->control_state;
 749                 spin_unlock_irq(&priv->lock);
 750                 mct_u232_set_modem_ctrl(port, control_state);
 751         } else {
 752                 spin_unlock_irq(&priv->lock);
 753         }
 754 }
 755
 756 static void mct_u232_unthrottle(struct tty_struct *tty)
 757 {
 758         struct usb_serial_port *port = tty->driver_data;
 759         struct mct_u232_private *priv = usb_get_serial_port_data(port);
 760         unsigned int control_state;
 761
 762         spin_lock_irq(&priv->lock);
 763         if ((priv->rx_flags & THROTTLED) && C_CRTSCTS(tty)) {
 764                 priv->rx_flags &= ~THROTTLED;
 765                 priv->control_state |= TIOCM_RTS;
 766                 control_state = priv->control_state;
 767                 spin_unlock_irq(&priv->lock);
 768                 mct_u232_set_modem_ctrl(port, control_state);
 769         } else {
 770                 spin_unlock_irq(&priv->lock);
 771         }
 772 }
 773
 774 module_usb_serial_driver(serial_drivers, id_table);
 775
 776 MODULE_AUTHOR(DRIVER_AUTHOR);
 777 MODULE_DESCRIPTION(DRIVER_DESC);
 778 MODULE_LICENSE("GPL");