drivers/usb/serial/usb-serial.c

   1 /*
   2  * USB Serial Converter driver
   3  *
   4  * Copyright (C) 1999 - 2012 Greg Kroah-Hartman (greg@kroah.com)
   5  * Copyright (C) 2000 Peter Berger (pberger@brimson.com)
   6  * Copyright (C) 2000 Al Borchers (borchers@steinerpoint.com)
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License version
  10  *      2 as published by the Free Software Foundation.
  11  *
  12  * This driver was originally based on the ACM driver by Armin Fuerst (which was
  13  * based on a driver by Brad Keryan)
  14  *
  15  * See Documentation/usb/usb-serial.txt for more information on using this
  16  * driver
  17  *
  18  */
  19
  20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  21
  22 #include <linux/kernel.h>
  23 #include <linux/errno.h>
  24 #include <linux/init.h>
  25 #include <linux/slab.h>
  26 #include <linux/tty.h>
  27 #include <linux/tty_driver.h>
  28 #include <linux/tty_flip.h>
  29 #include <linux/module.h>
  30 #include <linux/moduleparam.h>
  31 #include <linux/seq_file.h>
  32 #include <linux/spinlock.h>
  33 #include <linux/mutex.h>
  34 #include <linux/list.h>
  35 #include <linux/uaccess.h>
  36 #include <linux/serial.h>
  37 #include <linux/usb.h>
  38 #include <linux/usb/serial.h>
  39 #include <linux/kfifo.h>
  40 #include "pl2303.h"
  41
  42 #define DRIVER_AUTHOR "Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
  43 #define DRIVER_DESC "USB Serial Driver core"
  44
  45 /* There is no MODULE_DEVICE_TABLE for usbserial.c.  Instead
  46    the MODULE_DEVICE_TABLE declarations in each serial driver
  47    cause the "hotplug" program to pull in whatever module is necessary
  48    via modprobe, and modprobe will load usbserial because the serial
  49    drivers depend on it.
  50 */
  51
  52 /* initially all NULL */
  53 static struct usb_serial *serial_table[SERIAL_TTY_MINORS];
  54 static DEFINE_MUTEX(table_lock);
  55 static LIST_HEAD(usb_serial_driver_list);
  56
  57 /*
  58  * Look up the serial structure.  If it is found and it hasn't been
  59  * disconnected, return with its disc_mutex held and its refcount
  60  * incremented.  Otherwise return NULL.
  61  */
  62 struct usb_serial *usb_serial_get_by_index(unsigned index)
  63 {
  64         struct usb_serial *serial;
  65
  66         mutex_lock(&table_lock);
  67         serial = serial_table[index];
  68
  69         if (serial) {
  70                 mutex_lock(&serial->disc_mutex);
  71                 if (serial->disconnected) {
  72                         mutex_unlock(&serial->disc_mutex);
  73                         serial = NULL;
  74                 } else {
  75                         kref_get(&serial->kref);
  76                 }
  77         }
  78         mutex_unlock(&table_lock);
  79         return serial;
  80 }
  81
  82 static struct usb_serial *get_free_serial(struct usb_serial *serial,
  83                                         int num_ports, unsigned int *minor)
  84 {
  85         unsigned int i, j;
  86         int good_spot;
  87
  88         dev_dbg(&serial->interface->dev, "%s %d\n", __func__, num_ports);
  89
  90         *minor = 0;
  91         mutex_lock(&table_lock);
  92         for (i = 0; i < SERIAL_TTY_MINORS; ++i) {
  93                 if (serial_table[i])
  94                         continue;
  95
  96                 good_spot = 1;
  97                 for (j = 1; j <= num_ports-1; ++j)
  98                         if ((i+j >= SERIAL_TTY_MINORS) || (serial_table[i+j])) {
  99                                 good_spot = 0;
 100                                 i += j;
 101                                 break;
 102                         }
 103                 if (good_spot == 0)
 104                         continue;
 105
 106                 *minor = i;
 107                 j = 0;
 108                 dev_dbg(&serial->interface->dev, "%s - minor base = %d\n", __func__, *minor);
 109                 for (i = *minor; (i < (*minor + num_ports)) && (i < SERIAL_TTY_MINORS); ++i) {
 110                         serial_table[i] = serial;
 111                         serial->port[j++]->number = i;
 112                 }
 113                 mutex_unlock(&table_lock);
 114                 return serial;
 115         }
 116         mutex_unlock(&table_lock);
 117         return NULL;
 118 }
 119
 120 static void return_serial(struct usb_serial *serial)
 121 {
 122         int i;
 123
 124         mutex_lock(&table_lock);
 125         for (i = 0; i < serial->num_ports; ++i)
 126                 serial_table[serial->minor + i] = NULL;
 127         mutex_unlock(&table_lock);
 128 }
 129
 130 static void destroy_serial(struct kref *kref)
 131 {
 132         struct usb_serial *serial;
 133         struct usb_serial_port *port;
 134         int i;
 135
 136         serial = to_usb_serial(kref);
 137
 138         /* return the minor range that this device had */
 139         if (serial->minor != SERIAL_TTY_NO_MINOR)
 140                 return_serial(serial);
 141
 142         if (serial->attached)
 143                 serial->type->release(serial);
 144
 145         /* Now that nothing is using the ports, they can be freed */
 146         for (i = 0; i < serial->num_port_pointers; ++i) {
 147                 port = serial->port[i];
 148                 if (port) {
 149                         port->serial = NULL;
 150                         put_device(&port->dev);
 151                 }
 152         }
 153
 154         usb_put_dev(serial->dev);
 155         kfree(serial);
 156 }
 157
 158 void usb_serial_put(struct usb_serial *serial)
 159 {
 160         kref_put(&serial->kref, destroy_serial);
 161 }
 162
 163 /*****************************************************************************
 164  * Driver tty interface functions
 165  *****************************************************************************/
 166
 167 /**
 168  * serial_install - install tty
 169  * @driver: the driver (USB in our case)
 170  * @tty: the tty being created
 171  *
 172  * Create the termios objects for this tty.  We use the default
 173  * USB serial settings but permit them to be overridden by
 174  * serial->type->init_termios.
 175  *
 176  * This is the first place a new tty gets used.  Hence this is where we
 177  * acquire references to the usb_serial structure and the driver module,
 178  * where we store a pointer to the port, and where we do an autoresume.
 179  * All these actions are reversed in serial_cleanup().
 180  */
 181 static int serial_install(struct tty_driver *driver, struct tty_struct *tty)
 182 {
 183         int idx = tty->index;
 184         struct usb_serial *serial;
 185         struct usb_serial_port *port;
 186         int retval = -ENODEV;
 187
 188         serial = usb_serial_get_by_index(idx);
 189         if (!serial)
 190                 return retval;
 191
 192         port = serial->port[idx - serial->minor];
 193         if (!port)
 194                 goto error_no_port;
 195         if (!try_module_get(serial->type->driver.owner))
 196                 goto error_module_get;
 197
 198         retval = usb_autopm_get_interface(serial->interface);
 199         if (retval)
 200                 goto error_get_interface;
 201
 202         retval = tty_port_install(&port->port, driver, tty);
 203         if (retval)
 204                 goto error_init_termios;
 205
 206         mutex_unlock(&serial->disc_mutex);
 207
 208         /* allow the driver to update the settings */
 209         if (serial->type->init_termios)
 210                 serial->type->init_termios(tty);
 211
 212         tty->driver_data = port;
 213
 214         return retval;
 215
 216  error_init_termios:
 217         usb_autopm_put_interface(serial->interface);
 218  error_get_interface:
 219         module_put(serial->type->driver.owner);
 220  error_module_get:
 221  error_no_port:
 222         usb_serial_put(serial);
 223         mutex_unlock(&serial->disc_mutex);
 224         return retval;
 225 }
 226
 227 static int serial_activate(struct tty_port *tport, struct tty_struct *tty)
 228 {
 229         struct usb_serial_port *port =
 230                 container_of(tport, struct usb_serial_port, port);
 231         struct usb_serial *serial = port->serial;
 232         int retval;
 233
 234         mutex_lock(&serial->disc_mutex);
 235         if (serial->disconnected)
 236                 retval = -ENODEV;
 237         else
 238                 retval = port->serial->type->open(tty, port);
 239         mutex_unlock(&serial->disc_mutex);
 240
 241         if (retval < 0)
 242                 retval = usb_translate_errors(retval);
 243
 244         return retval;
 245 }
 246
 247 static int serial_open(struct tty_struct *tty, struct file *filp)
 248 {
 249         struct usb_serial_port *port = tty->driver_data;
 250
 251         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 252         return tty_port_open(&port->port, tty, filp);
 253 }
 254
 255 /**
 256  * serial_down - shut down hardware
 257  * @tport: tty port to shut down
 258  *
 259  * Shut down a USB serial port unless it is the console.  We never
 260  * shut down the console hardware as it will always be in use. Serialized
 261  * against activate by the tport mutex and kept to matching open/close pairs
 262  * of calls by the ASYNCB_INITIALIZED flag.
 263  */
 264 static void serial_down(struct tty_port *tport)
 265 {
 266         struct usb_serial_port *port =
 267                 container_of(tport, struct usb_serial_port, port);
 268         struct usb_serial_driver *drv = port->serial->type;
 269         /*
 270          * The console is magical.  Do not hang up the console hardware
 271          * or there will be tears.
 272          */
 273         if (port->port.console)
 274                 return;
 275         if (drv->close)
 276                 drv->close(port);
 277 }
 278
 279 static void serial_hangup(struct tty_struct *tty)
 280 {
 281         struct usb_serial_port *port = tty->driver_data;
 282
 283         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 284         tty_port_hangup(&port->port);
 285 }
 286
 287 static void serial_close(struct tty_struct *tty, struct file *filp)
 288 {
 289         struct usb_serial_port *port = tty->driver_data;
 290
 291         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 292         tty_port_close(&port->port, tty, filp);
 293 }
 294
 295 /**
 296  * serial_cleanup - free resources post close/hangup
 297  * @port: port to free up
 298  *
 299  * Do the resource freeing and refcount dropping for the port.
 300  * Avoid freeing the console.
 301  *
 302  * Called asynchronously after the last tty kref is dropped.
 303  */
 304 static void serial_cleanup(struct tty_struct *tty)
 305 {
 306         struct usb_serial_port *port = tty->driver_data;
 307         struct usb_serial *serial;
 308         struct module *owner;
 309
 310         /* The console is magical.  Do not hang up the console hardware
 311          * or there will be tears.
 312          */
 313         if (port->port.console)
 314                 return;
 315
 316         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 317
 318         tty->driver_data = NULL;
 319
 320         serial = port->serial;
 321         owner = serial->type->driver.owner;
 322
 323         mutex_lock(&serial->disc_mutex);
 324         if (!serial->disconnected)
 325                 usb_autopm_put_interface(serial->interface);
 326         mutex_unlock(&serial->disc_mutex);
 327
 328         usb_serial_put(serial);
 329         module_put(owner);
 330 }
 331
 332 static int serial_write(struct tty_struct *tty, const unsigned char *buf,
 333                                                                 int count)
 334 {
 335         struct usb_serial_port *port = tty->driver_data;
 336         int retval = -ENODEV;
 337
 338         if (port->serial->dev->state == USB_STATE_NOTATTACHED)
 339                 goto exit;
 340
 341         dev_dbg(tty->dev, "%s - port %d, %d byte(s)\n", __func__,
 342                 port->number, count);
 343
 344         /* pass on to the driver specific version of this function */
 345         retval = port->serial->type->write(tty, port, buf, count);
 346         if (retval < 0)
 347                 retval = usb_translate_errors(retval);
 348 exit:
 349         return retval;
 350 }
 351
 352 static int serial_write_room(struct tty_struct *tty)
 353 {
 354         struct usb_serial_port *port = tty->driver_data;
 355
 356         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 357         /* pass on to the driver specific version of this function */
 358         return port->serial->type->write_room(tty);
 359 }
 360
 361 static int serial_chars_in_buffer(struct tty_struct *tty)
 362 {
 363         struct usb_serial_port *port = tty->driver_data;
 364         struct usb_serial *serial = port->serial;
 365         int count = 0;
 366
 367         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 368
 369         mutex_lock(&serial->disc_mutex);
 370         /* if the device was unplugged then any remaining characters
 371            fell out of the connector ;) */
 372         if (serial->disconnected)
 373                 count = 0;
 374         else
 375                 count = serial->type->chars_in_buffer(tty);
 376         mutex_unlock(&serial->disc_mutex);
 377
 378         return count;
 379 }
 380
 381 static void serial_throttle(struct tty_struct *tty)
 382 {
 383         struct usb_serial_port *port = tty->driver_data;
 384
 385         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 386
 387         /* pass on to the driver specific version of this function */
 388         if (port->serial->type->throttle)
 389                 port->serial->type->throttle(tty);
 390 }
 391
 392 static void serial_unthrottle(struct tty_struct *tty)
 393 {
 394         struct usb_serial_port *port = tty->driver_data;
 395
 396         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 397
 398         /* pass on to the driver specific version of this function */
 399         if (port->serial->type->unthrottle)
 400                 port->serial->type->unthrottle(tty);
 401 }
 402
 403 static int serial_ioctl(struct tty_struct *tty,
 404                                         unsigned int cmd, unsigned long arg)
 405 {
 406         struct usb_serial_port *port = tty->driver_data;
 407         int retval = -ENODEV;
 408
 409         dev_dbg(tty->dev, "%s - port %d, cmd 0x%.4x\n", __func__,
 410                 port->number, cmd);
 411
 412         /* pass on to the driver specific version of this function
 413            if it is available */
 414         if (port->serial->type->ioctl) {
 415                 retval = port->serial->type->ioctl(tty, cmd, arg);
 416         } else
 417                 retval = -ENOIOCTLCMD;
 418         return retval;
 419 }
 420
 421 static void serial_set_termios(struct tty_struct *tty, struct ktermios *old)
 422 {
 423         struct usb_serial_port *port = tty->driver_data;
 424
 425         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 426
 427         /* pass on to the driver specific version of this function
 428            if it is available */
 429         if (port->serial->type->set_termios)
 430                 port->serial->type->set_termios(tty, port, old);
 431         else
 432                 tty_termios_copy_hw(&tty->termios, old);
 433 }
 434
 435 static int serial_break(struct tty_struct *tty, int break_state)
 436 {
 437         struct usb_serial_port *port = tty->driver_data;
 438
 439         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 440
 441         /* pass on to the driver specific version of this function
 442            if it is available */
 443         if (port->serial->type->break_ctl)
 444                 port->serial->type->break_ctl(tty, break_state);
 445         return 0;
 446 }
 447
 448 static int serial_proc_show(struct seq_file *m, void *v)
 449 {
 450         struct usb_serial *serial;
 451         int i;
 452         char tmp[40];
 453
 454         seq_puts(m, "usbserinfo:1.0 driver:2.0\n");
 455         for (i = 0; i < SERIAL_TTY_MINORS; ++i) {
 456                 serial = usb_serial_get_by_index(i);
 457                 if (serial == NULL)
 458                         continue;
 459
 460                 seq_printf(m, "%d:", i);
 461                 if (serial->type->driver.owner)
 462                         seq_printf(m, " module:%s",
 463                                 module_name(serial->type->driver.owner));
 464                 seq_printf(m, " name:\"%s\"",
 465                                 serial->type->description);
 466                 seq_printf(m, " vendor:%04x product:%04x",
 467                         le16_to_cpu(serial->dev->descriptor.idVendor),
 468                         le16_to_cpu(serial->dev->descriptor.idProduct));
 469                 seq_printf(m, " num_ports:%d", serial->num_ports);
 470                 seq_printf(m, " port:%d", i - serial->minor + 1);
 471                 usb_make_path(serial->dev, tmp, sizeof(tmp));
 472                 seq_printf(m, " path:%s", tmp);
 473
 474                 seq_putc(m, '\n');
 475                 usb_serial_put(serial);
 476                 mutex_unlock(&serial->disc_mutex);
 477         }
 478         return 0;
 479 }
 480
 481 static int serial_proc_open(struct inode *inode, struct file *file)
 482 {
 483         return single_open(file, serial_proc_show, NULL);
 484 }
 485
 486 static const struct file_operations serial_proc_fops = {
 487         .owner          = THIS_MODULE,
 488         .open           = serial_proc_open,
 489         .read           = seq_read,
 490         .llseek         = seq_lseek,
 491         .release        = single_release,
 492 };
 493
 494 static int serial_tiocmget(struct tty_struct *tty)
 495 {
 496         struct usb_serial_port *port = tty->driver_data;
 497
 498         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 499
 500         if (port->serial->type->tiocmget)
 501                 return port->serial->type->tiocmget(tty);
 502         return -EINVAL;
 503 }
 504
 505 static int serial_tiocmset(struct tty_struct *tty,
 506                             unsigned int set, unsigned int clear)
 507 {
 508         struct usb_serial_port *port = tty->driver_data;
 509
 510         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 511
 512         if (port->serial->type->tiocmset)
 513                 return port->serial->type->tiocmset(tty, set, clear);
 514         return -EINVAL;
 515 }
 516
 517 static int serial_get_icount(struct tty_struct *tty,
 518                                 struct serial_icounter_struct *icount)
 519 {
 520         struct usb_serial_port *port = tty->driver_data;
 521
 522         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 523
 524         if (port->serial->type->get_icount)
 525                 return port->serial->type->get_icount(tty, icount);
 526         return -EINVAL;
 527 }
 528
 529 /*
 530  * We would be calling tty_wakeup here, but unfortunately some line
 531  * disciplines have an annoying habit of calling tty->write from
 532  * the write wakeup callback (e.g. n_hdlc.c).
 533  */
 534 void usb_serial_port_softint(struct usb_serial_port *port)
 535 {
 536         schedule_work(&port->work);
 537 }
 538 EXPORT_SYMBOL_GPL(usb_serial_port_softint);
 539
 540 static void usb_serial_port_work(struct work_struct *work)
 541 {
 542         struct usb_serial_port *port =
 543                 container_of(work, struct usb_serial_port, work);
 544
 545         tty_port_tty_wakeup(&port->port);
 546 }
 547
 548 static void kill_traffic(struct usb_serial_port *port)
 549 {
 550         int i;
 551
 552         for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)
 553                 usb_kill_urb(port->read_urbs[i]);
 554         for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
 555                 usb_kill_urb(port->write_urbs[i]);
 556         /*
 557          * This is tricky.
 558          * Some drivers submit the read_urb in the
 559          * handler for the write_urb or vice versa
 560          * this order determines the order in which
 561          * usb_kill_urb() must be used to reliably
 562          * kill the URBs. As it is unknown here,
 563          * both orders must be used in turn.
 564          * The call below is not redundant.
 565          */
 566         usb_kill_urb(port->read_urb);
 567         usb_kill_urb(port->interrupt_in_urb);
 568         usb_kill_urb(port->interrupt_out_urb);
 569 }
 570
 571 static void port_release(struct device *dev)
 572 {
 573         struct usb_serial_port *port = to_usb_serial_port(dev);
 574         int i;
 575
 576         dev_dbg(dev, "%s\n", __func__);
 577
 578         /*
 579          * Stop all the traffic before cancelling the work, so that
 580          * nobody will restart it by calling usb_serial_port_softint.
 581          */
 582         kill_traffic(port);
 583         cancel_work_sync(&port->work);
 584
 585         usb_free_urb(port->interrupt_in_urb);
 586         usb_free_urb(port->interrupt_out_urb);
 587         for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
 588                 usb_free_urb(port->read_urbs[i]);
 589                 kfree(port->bulk_in_buffers[i]);
 590         }
 591         for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) {
 592                 usb_free_urb(port->write_urbs[i]);
 593                 kfree(port->bulk_out_buffers[i]);
 594         }
 595         kfifo_free(&port->write_fifo);
 596         kfree(port->interrupt_in_buffer);
 597         kfree(port->interrupt_out_buffer);
 598         tty_port_destroy(&port->port);
 599         kfree(port);
 600 }
 601
 602 static struct usb_serial *create_serial(struct usb_device *dev,
 603                                         struct usb_interface *interface,
 604                                         struct usb_serial_driver *driver)
 605 {
 606         struct usb_serial *serial;
 607
 608         serial = kzalloc(sizeof(*serial), GFP_KERNEL);
 609         if (!serial) {
 610                 dev_err(&dev->dev, "%s - out of memory\n", __func__);
 611                 return NULL;
 612         }
 613         serial->dev = usb_get_dev(dev);
 614         serial->type = driver;
 615         serial->interface = interface;
 616         kref_init(&serial->kref);
 617         mutex_init(&serial->disc_mutex);
 618         serial->minor = SERIAL_TTY_NO_MINOR;
 619
 620         return serial;
 621 }
 622
 623 static const struct usb_device_id *match_dynamic_id(struct usb_interface *intf,
 624                                             struct usb_serial_driver *drv)
 625 {
 626         struct usb_dynid *dynid;
 627
 628         spin_lock(&drv->dynids.lock);
 629         list_for_each_entry(dynid, &drv->dynids.list, node) {
 630                 if (usb_match_one_id(intf, &dynid->id)) {
 631                         spin_unlock(&drv->dynids.lock);
 632                         return &dynid->id;
 633                 }
 634         }
 635         spin_unlock(&drv->dynids.lock);
 636         return NULL;
 637 }
 638
 639 static const struct usb_device_id *get_iface_id(struct usb_serial_driver *drv,
 640                                                 struct usb_interface *intf)
 641 {
 642         const struct usb_device_id *id;
 643
 644         id = usb_match_id(intf, drv->id_table);
 645         if (id) {
 646                 dev_dbg(&intf->dev, "static descriptor matches\n");
 647                 goto exit;
 648         }
 649         id = match_dynamic_id(intf, drv);
 650         if (id)
 651                 dev_dbg(&intf->dev, "dynamic descriptor matches\n");
 652 exit:
 653         return id;
 654 }
 655
 656 /* Caller must hold table_lock */
 657 static struct usb_serial_driver *search_serial_device(
 658                                         struct usb_interface *iface)
 659 {
 660         const struct usb_device_id *id = NULL;
 661         struct usb_serial_driver *drv;
 662         struct usb_driver *driver = to_usb_driver(iface->dev.driver);
 663
 664         /* Check if the usb id matches a known device */
 665         list_for_each_entry(drv, &usb_serial_driver_list, driver_list) {
 666                 if (drv->usb_driver == driver)
 667                         id = get_iface_id(drv, iface);
 668                 if (id)
 669                         return drv;
 670         }
 671
 672         return NULL;
 673 }
 674
 675 static int serial_carrier_raised(struct tty_port *port)
 676 {
 677         struct usb_serial_port *p = container_of(port, struct usb_serial_port, port);
 678         struct usb_serial_driver *drv = p->serial->type;
 679
 680         if (drv->carrier_raised)
 681                 return drv->carrier_raised(p);
 682         /* No carrier control - don't block */
 683         return 1;
 684 }
 685
 686 static void serial_dtr_rts(struct tty_port *port, int on)
 687 {
 688         struct usb_serial_port *p = container_of(port, struct usb_serial_port, port);
 689         struct usb_serial *serial = p->serial;
 690         struct usb_serial_driver *drv = serial->type;
 691
 692         if (!drv->dtr_rts)
 693                 return;
 694         /*
 695          * Work-around bug in the tty-layer which can result in dtr_rts
 696          * being called after a disconnect (and tty_unregister_device
 697          * has returned). Remove once bug has been squashed.
 698          */
 699         mutex_lock(&serial->disc_mutex);
 700         if (!serial->disconnected)
 701                 drv->dtr_rts(p, on);
 702         mutex_unlock(&serial->disc_mutex);
 703 }
 704
 705 static const struct tty_port_operations serial_port_ops = {
 706         .carrier_raised = serial_carrier_raised,
 707         .dtr_rts = serial_dtr_rts,
 708         .activate = serial_activate,
 709         .shutdown = serial_down,
 710 };
 711
 712 static int usb_serial_probe(struct usb_interface *interface,
 713                                const struct usb_device_id *id)
 714 {
 715         struct device *ddev = &interface->dev;
 716         struct usb_device *dev = interface_to_usbdev(interface);
 717         struct usb_serial *serial = NULL;
 718         struct usb_serial_port *port;
 719         struct usb_host_interface *iface_desc;
 720         struct usb_endpoint_descriptor *endpoint;
 721         struct usb_endpoint_descriptor *interrupt_in_endpoint[MAX_NUM_PORTS];
 722         struct usb_endpoint_descriptor *interrupt_out_endpoint[MAX_NUM_PORTS];
 723         struct usb_endpoint_descriptor *bulk_in_endpoint[MAX_NUM_PORTS];
 724         struct usb_endpoint_descriptor *bulk_out_endpoint[MAX_NUM_PORTS];
 725         struct usb_serial_driver *type = NULL;
 726         int retval;
 727         unsigned int minor;
 728         int buffer_size;
 729         int i;
 730         int j;
 731         int num_interrupt_in = 0;
 732         int num_interrupt_out = 0;
 733         int num_bulk_in = 0;
 734         int num_bulk_out = 0;
 735         int num_ports = 0;
 736         int max_endpoints;
 737
 738         mutex_lock(&table_lock);
 739         type = search_serial_device(interface);
 740         if (!type) {
 741                 mutex_unlock(&table_lock);
 742                 dev_dbg(ddev, "none matched\n");
 743                 return -ENODEV;
 744         }
 745
 746         if (!try_module_get(type->driver.owner)) {
 747                 mutex_unlock(&table_lock);
 748                 dev_err(ddev, "module get failed, exiting\n");
 749                 return -EIO;
 750         }
 751         mutex_unlock(&table_lock);
 752
 753         serial = create_serial(dev, interface, type);
 754         if (!serial) {
 755                 module_put(type->driver.owner);
 756                 dev_err(ddev, "%s - out of memory\n", __func__);
 757                 return -ENOMEM;
 758         }
 759
 760         /* if this device type has a probe function, call it */
 761         if (type->probe) {
 762                 const struct usb_device_id *id;
 763
 764                 id = get_iface_id(type, interface);
 765                 retval = type->probe(serial, id);
 766
 767                 if (retval) {
 768                         dev_dbg(ddev, "sub driver rejected device\n");
 769                         usb_serial_put(serial);
 770                         module_put(type->driver.owner);
 771                         return retval;
 772                 }
 773         }
 774
 775         /* descriptor matches, let's find the endpoints needed */
 776         /* check out the endpoints */
 777         iface_desc = interface->cur_altsetting;
 778         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 779                 endpoint = &iface_desc->endpoint[i].desc;
 780
 781                 if (usb_endpoint_is_bulk_in(endpoint)) {
 782                         /* we found a bulk in endpoint */
 783                         dev_dbg(ddev, "found bulk in on endpoint %d\n", i);
 784                         bulk_in_endpoint[num_bulk_in] = endpoint;
 785                         ++num_bulk_in;
 786                 }
 787
 788                 if (usb_endpoint_is_bulk_out(endpoint)) {
 789                         /* we found a bulk out endpoint */
 790                         dev_dbg(ddev, "found bulk out on endpoint %d\n", i);
 791                         bulk_out_endpoint[num_bulk_out] = endpoint;
 792                         ++num_bulk_out;
 793                 }
 794
 795                 if (usb_endpoint_is_int_in(endpoint)) {
 796                         /* we found a interrupt in endpoint */
 797                         dev_dbg(ddev, "found interrupt in on endpoint %d\n", i);
 798                         interrupt_in_endpoint[num_interrupt_in] = endpoint;
 799                         ++num_interrupt_in;
 800                 }
 801
 802                 if (usb_endpoint_is_int_out(endpoint)) {
 803                         /* we found an interrupt out endpoint */
 804                         dev_dbg(ddev, "found interrupt out on endpoint %d\n", i);
 805                         interrupt_out_endpoint[num_interrupt_out] = endpoint;
 806                         ++num_interrupt_out;
 807                 }
 808         }
 809
 810 #if defined(CONFIG_USB_SERIAL_PL2303) || defined(CONFIG_USB_SERIAL_PL2303_MODULE)
 811         /* BEGIN HORRIBLE HACK FOR PL2303 */
 812         /* this is needed due to the looney way its endpoints are set up */
 813         if (((le16_to_cpu(dev->descriptor.idVendor) == PL2303_VENDOR_ID) &&
 814              (le16_to_cpu(dev->descriptor.idProduct) == PL2303_PRODUCT_ID)) ||
 815             ((le16_to_cpu(dev->descriptor.idVendor) == ATEN_VENDOR_ID) &&
 816              (le16_to_cpu(dev->descriptor.idProduct) == ATEN_PRODUCT_ID)) ||
 817             ((le16_to_cpu(dev->descriptor.idVendor) == ALCOR_VENDOR_ID) &&
 818              (le16_to_cpu(dev->descriptor.idProduct) == ALCOR_PRODUCT_ID)) ||
 819             ((le16_to_cpu(dev->descriptor.idVendor) == SIEMENS_VENDOR_ID) &&
 820              (le16_to_cpu(dev->descriptor.idProduct) == SIEMENS_PRODUCT_ID_EF81))) {
 821                 if (interface != dev->actconfig->interface[0]) {
 822                         /* check out the endpoints of the other interface*/
 823                         iface_desc = dev->actconfig->interface[0]->cur_altsetting;
 824                         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 825                                 endpoint = &iface_desc->endpoint[i].desc;
 826                                 if (usb_endpoint_is_int_in(endpoint)) {
 827                                         /* we found a interrupt in endpoint */
 828                                         dev_dbg(ddev, "found interrupt in for Prolific device on separate interface\n");
 829                                         interrupt_in_endpoint[num_interrupt_in] = endpoint;
 830                                         ++num_interrupt_in;
 831                                 }
 832                         }
 833                 }
 834
 835                 /* Now make sure the PL-2303 is configured correctly.
 836                  * If not, give up now and hope this hack will work
 837                  * properly during a later invocation of usb_serial_probe
 838                  */
 839                 if (num_bulk_in == 0 || num_bulk_out == 0) {
 840                         dev_info(ddev, "PL-2303 hack: descriptors matched but endpoints did not\n");
 841                         usb_serial_put(serial);
 842                         module_put(type->driver.owner);
 843                         return -ENODEV;
 844                 }
 845         }
 846         /* END HORRIBLE HACK FOR PL2303 */
 847 #endif
 848
 849 #ifdef CONFIG_USB_SERIAL_GENERIC
 850         if (type == &usb_serial_generic_device) {
 851                 num_ports = num_bulk_out;
 852                 if (num_ports == 0) {
 853                         dev_err(ddev, "Generic device with no bulk out, not allowed.\n");
 854                         usb_serial_put(serial);
 855                         module_put(type->driver.owner);
 856                         return -EIO;
 857                 }
 858                 dev_info(ddev, "The \"generic\" usb-serial driver is only for testing and one-off prototypes.\n");
 859                 dev_info(ddev, "Tell linux-usb@vger.kernel.org to add your device to a proper driver.\n");
 860         }
 861 #endif
 862         if (!num_ports) {
 863                 /* if this device type has a calc_num_ports function, call it */
 864                 if (type->calc_num_ports)
 865                         num_ports = type->calc_num_ports(serial);
 866                 if (!num_ports)
 867                         num_ports = type->num_ports;
 868         }
 869
 870         serial->num_ports = num_ports;
 871         serial->num_bulk_in = num_bulk_in;
 872         serial->num_bulk_out = num_bulk_out;
 873         serial->num_interrupt_in = num_interrupt_in;
 874         serial->num_interrupt_out = num_interrupt_out;
 875
 876         /* found all that we need */
 877         dev_info(ddev, "%s converter detected\n", type->description);
 878
 879         /* create our ports, we need as many as the max endpoints */
 880         /* we don't use num_ports here because some devices have more
 881            endpoint pairs than ports */
 882         max_endpoints = max(num_bulk_in, num_bulk_out);
 883         max_endpoints = max(max_endpoints, num_interrupt_in);
 884         max_endpoints = max(max_endpoints, num_interrupt_out);
 885         max_endpoints = max(max_endpoints, (int)serial->num_ports);
 886         serial->num_port_pointers = max_endpoints;
 887
 888         dev_dbg(ddev, "setting up %d port structures for this device", max_endpoints);
 889         for (i = 0; i < max_endpoints; ++i) {
 890                 port = kzalloc(sizeof(struct usb_serial_port), GFP_KERNEL);
 891                 if (!port)
 892                         goto probe_error;
 893                 tty_port_init(&port->port);
 894                 port->port.ops = &serial_port_ops;
 895                 port->serial = serial;
 896                 spin_lock_init(&port->lock);
 897                 /* Keep this for private driver use for the moment but
 898                    should probably go away */
 899                 INIT_WORK(&port->work, usb_serial_port_work);
 900                 serial->port[i] = port;
 901                 port->dev.parent = &interface->dev;
 902                 port->dev.driver = NULL;
 903                 port->dev.bus = &usb_serial_bus_type;
 904                 port->dev.release = &port_release;
 905                 device_initialize(&port->dev);
 906         }
 907
 908         /* set up the endpoint information */
 909         for (i = 0; i < num_bulk_in; ++i) {
 910                 endpoint = bulk_in_endpoint[i];
 911                 port = serial->port[i];
 912                 buffer_size = max_t(int, serial->type->bulk_in_size,
 913                                 usb_endpoint_maxp(endpoint));
 914                 port->bulk_in_size = buffer_size;
 915                 port->bulk_in_endpointAddress = endpoint->bEndpointAddress;
 916
 917                 for (j = 0; j < ARRAY_SIZE(port->read_urbs); ++j) {
 918                         set_bit(j, &port->read_urbs_free);
 919                         port->read_urbs[j] = usb_alloc_urb(0, GFP_KERNEL);
 920                         if (!port->read_urbs[j]) {
 921                                 dev_err(ddev, "No free urbs available\n");
 922                                 goto probe_error;
 923                         }
 924                         port->bulk_in_buffers[j] = kmalloc(buffer_size,
 925                                                                 GFP_KERNEL);
 926                         if (!port->bulk_in_buffers[j]) {
 927                                 dev_err(ddev, "Couldn't allocate bulk_in_buffer\n");
 928                                 goto probe_error;
 929                         }
 930                         usb_fill_bulk_urb(port->read_urbs[j], dev,
 931                                         usb_rcvbulkpipe(dev,
 932                                                 endpoint->bEndpointAddress),
 933                                         port->bulk_in_buffers[j], buffer_size,
 934                                         serial->type->read_bulk_callback,
 935                                         port);
 936                 }
 937
 938                 port->read_urb = port->read_urbs[0];
 939                 port->bulk_in_buffer = port->bulk_in_buffers[0];
 940         }
 941
 942         for (i = 0; i < num_bulk_out; ++i) {
 943                 endpoint = bulk_out_endpoint[i];
 944                 port = serial->port[i];
 945                 if (kfifo_alloc(&port->write_fifo, PAGE_SIZE, GFP_KERNEL))
 946                         goto probe_error;
 947                 buffer_size = serial->type->bulk_out_size;
 948                 if (!buffer_size)
 949                         buffer_size = usb_endpoint_maxp(endpoint);
 950                 port->bulk_out_size = buffer_size;
 951                 port->bulk_out_endpointAddress = endpoint->bEndpointAddress;
 952
 953                 for (j = 0; j < ARRAY_SIZE(port->write_urbs); ++j) {
 954                         set_bit(j, &port->write_urbs_free);
 955                         port->write_urbs[j] = usb_alloc_urb(0, GFP_KERNEL);
 956                         if (!port->write_urbs[j]) {
 957                                 dev_err(ddev, "No free urbs available\n");
 958                                 goto probe_error;
 959                         }
 960                         port->bulk_out_buffers[j] = kmalloc(buffer_size,
 961                                                                 GFP_KERNEL);
 962                         if (!port->bulk_out_buffers[j]) {
 963                                 dev_err(ddev, "Couldn't allocate bulk_out_buffer\n");
 964                                 goto probe_error;
 965                         }
 966                         usb_fill_bulk_urb(port->write_urbs[j], dev,
 967                                         usb_sndbulkpipe(dev,
 968                                                 endpoint->bEndpointAddress),
 969                                         port->bulk_out_buffers[j], buffer_size,
 970                                         serial->type->write_bulk_callback,
 971                                         port);
 972                 }
 973
 974                 port->write_urb = port->write_urbs[0];
 975                 port->bulk_out_buffer = port->bulk_out_buffers[0];
 976         }
 977
 978         if (serial->type->read_int_callback) {
 979                 for (i = 0; i < num_interrupt_in; ++i) {
 980                         endpoint = interrupt_in_endpoint[i];
 981                         port = serial->port[i];
 982                         port->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 983                         if (!port->interrupt_in_urb) {
 984                                 dev_err(ddev, "No free urbs available\n");
 985                                 goto probe_error;
 986                         }
 987                         buffer_size = usb_endpoint_maxp(endpoint);
 988                         port->interrupt_in_endpointAddress =
 989                                                 endpoint->bEndpointAddress;
 990                         port->interrupt_in_buffer = kmalloc(buffer_size,
 991                                                                 GFP_KERNEL);
 992                         if (!port->interrupt_in_buffer) {
 993                                 dev_err(ddev, "Couldn't allocate interrupt_in_buffer\n");
 994                                 goto probe_error;
 995                         }
 996                         usb_fill_int_urb(port->interrupt_in_urb, dev,
 997                                 usb_rcvintpipe(dev,
 998                                                 endpoint->bEndpointAddress),
 999                                 port->interrupt_in_buffer, buffer_size,
1000                                 serial->type->read_int_callback, port,
1001                                 endpoint->bInterval);
1002                 }
1003         } else if (num_interrupt_in) {
1004                 dev_dbg(ddev, "The device claims to support interrupt in transfers, but read_int_callback is not defined\n");
1005         }
1006
1007         if (serial->type->write_int_callback) {
1008                 for (i = 0; i < num_interrupt_out; ++i) {
1009                         endpoint = interrupt_out_endpoint[i];
1010                         port = serial->port[i];
1011                         port->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
1012                         if (!port->interrupt_out_urb) {
1013                                 dev_err(ddev, "No free urbs available\n");
1014                                 goto probe_error;
1015                         }
1016                         buffer_size = usb_endpoint_maxp(endpoint);
1017                         port->interrupt_out_size = buffer_size;
1018                         port->interrupt_out_endpointAddress =
1019                                                 endpoint->bEndpointAddress;
1020                         port->interrupt_out_buffer = kmalloc(buffer_size,
1021                                                                 GFP_KERNEL);
1022                         if (!port->interrupt_out_buffer) {
1023                                 dev_err(ddev, "Couldn't allocate interrupt_out_buffer\n");
1024                                 goto probe_error;
1025                         }
1026                         usb_fill_int_urb(port->interrupt_out_urb, dev,
1027                                 usb_sndintpipe(dev,
1028                                                   endpoint->bEndpointAddress),
1029                                 port->interrupt_out_buffer, buffer_size,
1030                                 serial->type->write_int_callback, port,
1031                                 endpoint->bInterval);
1032                 }
1033         } else if (num_interrupt_out) {
1034                 dev_dbg(ddev, "The device claims to support interrupt out transfers, but write_int_callback is not defined\n");
1035         }
1036
1037         usb_set_intfdata(interface, serial);
1038
1039         /* if this device type has an attach function, call it */
1040         if (type->attach) {
1041                 retval = type->attach(serial);
1042                 if (retval < 0)
1043                         goto probe_error;
1044                 serial->attached = 1;
1045                 if (retval > 0) {
1046                         /* quietly accept this device, but don't bind to a
1047                            serial port as it's about to disappear */
1048                         serial->num_ports = 0;
1049                         goto exit;
1050                 }
1051         } else {
1052                 serial->attached = 1;
1053         }
1054
1055         /* Avoid race with tty_open and serial_install by setting the
1056          * disconnected flag and not clearing it until all ports have been
1057          * registered.
1058          */
1059         serial->disconnected = 1;
1060
1061         if (get_free_serial(serial, num_ports, &minor) == NULL) {
1062                 dev_err(ddev, "No more free serial devices\n");
1063                 goto probe_error;
1064         }
1065         serial->minor = minor;
1066
1067         /* register all of the individual ports with the driver core */
1068         for (i = 0; i < num_ports; ++i) {
1069                 port = serial->port[i];
1070                 dev_set_name(&port->dev, "ttyUSB%d", port->number);
1071                 dev_dbg(ddev, "registering %s", dev_name(&port->dev));
1072                 device_enable_async_suspend(&port->dev);
1073
1074                 retval = device_add(&port->dev);
1075                 if (retval)
1076                         dev_err(ddev, "Error registering port device, continuing\n");
1077         }
1078
1079         serial->disconnected = 0;
1080
1081         usb_serial_console_init(minor);
1082 exit:
1083         module_put(type->driver.owner);
1084         return 0;
1085
1086 probe_error:
1087         usb_serial_put(serial);
1088         module_put(type->driver.owner);
1089         return -EIO;
1090 }
1091
1092 static void usb_serial_disconnect(struct usb_interface *interface)
1093 {
1094         int i;
1095         struct usb_serial *serial = usb_get_intfdata(interface);
1096         struct device *dev = &interface->dev;
1097         struct usb_serial_port *port;
1098
1099         usb_serial_console_disconnect(serial);
1100
1101         mutex_lock(&serial->disc_mutex);
1102         /* must set a flag, to signal subdrivers */
1103         serial->disconnected = 1;
1104         mutex_unlock(&serial->disc_mutex);
1105
1106         for (i = 0; i < serial->num_ports; ++i) {
1107                 port = serial->port[i];
1108                 if (port) {
1109                         struct tty_struct *tty = tty_port_tty_get(&port->port);
1110                         if (tty) {
1111                                 tty_vhangup(tty);
1112                                 tty_kref_put(tty);
1113                         }
1114                         kill_traffic(port);
1115                         cancel_work_sync(&port->work);
1116                         if (device_is_registered(&port->dev))
1117                                 device_del(&port->dev);
1118                 }
1119         }
1120         serial->type->disconnect(serial);
1121
1122         /* let the last holder of this object cause it to be cleaned up */
1123         usb_serial_put(serial);
1124         dev_info(dev, "device disconnected\n");
1125 }
1126
1127 int usb_serial_suspend(struct usb_interface *intf, pm_message_t message)
1128 {
1129         struct usb_serial *serial = usb_get_intfdata(intf);
1130         struct usb_serial_port *port;
1131         int i, r = 0;
1132
1133         serial->suspending = 1;
1134
1135         if (serial->type->suspend) {
1136                 r = serial->type->suspend(serial, message);
1137                 if (r < 0) {
1138                         serial->suspending = 0;
1139                         goto err_out;
1140                 }
1141         }
1142
1143         for (i = 0; i < serial->num_ports; ++i) {
1144                 port = serial->port[i];
1145                 if (port)
1146                         kill_traffic(port);
1147         }
1148
1149 err_out:
1150         return r;
1151 }
1152 EXPORT_SYMBOL(usb_serial_suspend);
1153
1154 int usb_serial_resume(struct usb_interface *intf)
1155 {
1156         struct usb_serial *serial = usb_get_intfdata(intf);
1157         int rv;
1158
1159         serial->suspending = 0;
1160         if (serial->type->resume)
1161                 rv = serial->type->resume(serial);
1162         else
1163                 rv = usb_serial_generic_resume(serial);
1164
1165         return rv;
1166 }
1167 EXPORT_SYMBOL(usb_serial_resume);
1168
1169 static int usb_serial_reset_resume(struct usb_interface *intf)
1170 {
1171         struct usb_serial *serial = usb_get_intfdata(intf);
1172         int rv;
1173
1174         serial->suspending = 0;
1175         if (serial->type->reset_resume)
1176                 rv = serial->type->reset_resume(serial);
1177         else {
1178                 rv = -EOPNOTSUPP;
1179                 intf->needs_binding = 1;
1180         }
1181
1182         return rv;
1183 }
1184
1185 static const struct tty_operations serial_ops = {
1186         .open =                 serial_open,
1187         .close =                serial_close,
1188         .write =                serial_write,
1189         .hangup =               serial_hangup,
1190         .write_room =           serial_write_room,
1191         .ioctl =                serial_ioctl,
1192         .set_termios =          serial_set_termios,
1193         .throttle =             serial_throttle,
1194         .unthrottle =           serial_unthrottle,
1195         .break_ctl =            serial_break,
1196         .chars_in_buffer =      serial_chars_in_buffer,
1197         .tiocmget =             serial_tiocmget,
1198         .tiocmset =             serial_tiocmset,
1199         .get_icount =           serial_get_icount,
1200         .cleanup =              serial_cleanup,
1201         .install =              serial_install,
1202         .proc_fops =            &serial_proc_fops,
1203 };
1204
1205
1206 struct tty_driver *usb_serial_tty_driver;
1207
1208 /* Driver structure we register with the USB core */
1209 static struct usb_driver usb_serial_driver = {
1210         .name =         "usbserial",
1211         .probe =        usb_serial_probe,
1212         .disconnect =   usb_serial_disconnect,
1213         .suspend =      usb_serial_suspend,
1214         .resume =       usb_serial_resume,
1215         .no_dynamic_id =        1,
1216         .supports_autosuspend = 1,
1217 };
1218
1219 static int __init usb_serial_init(void)
1220 {
1221         int i;
1222         int result;
1223
1224         usb_serial_tty_driver = alloc_tty_driver(SERIAL_TTY_MINORS);
1225         if (!usb_serial_tty_driver)
1226                 return -ENOMEM;
1227
1228         /* Initialize our global data */
1229         for (i = 0; i < SERIAL_TTY_MINORS; ++i)
1230                 serial_table[i] = NULL;
1231
1232         result = bus_register(&usb_serial_bus_type);
1233         if (result) {
1234                 pr_err("%s - registering bus driver failed\n", __func__);
1235                 goto exit_bus;
1236         }
1237
1238         usb_serial_tty_driver->driver_name = "usbserial";
1239         usb_serial_tty_driver->name = "ttyUSB";
1240         usb_serial_tty_driver->major = SERIAL_TTY_MAJOR;
1241         usb_serial_tty_driver->minor_start = 0;
1242         usb_serial_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
1243         usb_serial_tty_driver->subtype = SERIAL_TYPE_NORMAL;
1244         usb_serial_tty_driver->flags = TTY_DRIVER_REAL_RAW |
1245                                                 TTY_DRIVER_DYNAMIC_DEV;
1246         usb_serial_tty_driver->init_termios = tty_std_termios;
1247         usb_serial_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD
1248                                                         | HUPCL | CLOCAL;
1249         usb_serial_tty_driver->init_termios.c_ispeed = 9600;
1250         usb_serial_tty_driver->init_termios.c_ospeed = 9600;
1251         tty_set_operations(usb_serial_tty_driver, &serial_ops);
1252         result = tty_register_driver(usb_serial_tty_driver);
1253         if (result) {
1254                 pr_err("%s - tty_register_driver failed\n", __func__);
1255                 goto exit_reg_driver;
1256         }
1257
1258         /* register the USB driver */
1259         result = usb_register(&usb_serial_driver);
1260         if (result < 0) {
1261                 pr_err("%s - usb_register failed\n", __func__);
1262                 goto exit_tty;
1263         }
1264
1265         /* register the generic driver, if we should */
1266         result = usb_serial_generic_register();
1267         if (result < 0) {
1268                 pr_err("%s - registering generic driver failed\n", __func__);
1269                 goto exit_generic;
1270         }
1271
1272         return result;
1273
1274 exit_generic:
1275         usb_deregister(&usb_serial_driver);
1276
1277 exit_tty:
1278         tty_unregister_driver(usb_serial_tty_driver);
1279
1280 exit_reg_driver:
1281         bus_unregister(&usb_serial_bus_type);
1282
1283 exit_bus:
1284         pr_err("%s - returning with error %d\n", __func__, result);
1285         put_tty_driver(usb_serial_tty_driver);
1286         return result;
1287 }
1288
1289
1290 static void __exit usb_serial_exit(void)
1291 {
1292         usb_serial_console_exit();
1293
1294         usb_serial_generic_deregister();
1295
1296         usb_deregister(&usb_serial_driver);
1297         tty_unregister_driver(usb_serial_tty_driver);
1298         put_tty_driver(usb_serial_tty_driver);
1299         bus_unregister(&usb_serial_bus_type);
1300 }
1301
1302
1303 module_init(usb_serial_init);
1304 module_exit(usb_serial_exit);
1305
1306 #define set_to_generic_if_null(type, function)                          \
1307         do {                                                            \
1308                 if (!type->function) {                                  \
1309                         type->function = usb_serial_generic_##function; \
1310                         pr_debug("Had to override the " #function       \
1311                                 " usb serial operation with the generic one.");\
1312                         }                                               \
1313         } while (0)
1314
1315 static void fixup_generic(struct usb_serial_driver *device)
1316 {
1317         set_to_generic_if_null(device, open);
1318         set_to_generic_if_null(device, write);
1319         set_to_generic_if_null(device, close);
1320         set_to_generic_if_null(device, write_room);
1321         set_to_generic_if_null(device, chars_in_buffer);
1322         set_to_generic_if_null(device, read_bulk_callback);
1323         set_to_generic_if_null(device, write_bulk_callback);
1324         set_to_generic_if_null(device, disconnect);
1325         set_to_generic_if_null(device, release);
1326         set_to_generic_if_null(device, process_read_urb);
1327         set_to_generic_if_null(device, prepare_write_buffer);
1328 }
1329
1330 static int usb_serial_register(struct usb_serial_driver *driver)
1331 {
1332         int retval;
1333
1334         if (usb_disabled())
1335                 return -ENODEV;
1336
1337         fixup_generic(driver);
1338
1339         if (!driver->description)
1340                 driver->description = driver->driver.name;
1341         if (!driver->usb_driver) {
1342                 WARN(1, "Serial driver %s has no usb_driver\n",
1343                                 driver->description);
1344                 return -EINVAL;
1345         }
1346
1347         /* Add this device to our list of devices */
1348         mutex_lock(&table_lock);
1349         list_add(&driver->driver_list, &usb_serial_driver_list);
1350
1351         retval = usb_serial_bus_register(driver);
1352         if (retval) {
1353                 pr_err("problem %d when registering driver %s\n", retval, driver->description);
1354                 list_del(&driver->driver_list);
1355         } else
1356                 pr_info("USB Serial support registered for %s\n", driver->description);
1357
1358         mutex_unlock(&table_lock);
1359         return retval;
1360 }
1361
1362 static void usb_serial_deregister(struct usb_serial_driver *device)
1363 {
1364         pr_info("USB Serial deregistering driver %s\n", device->description);
1365         mutex_lock(&table_lock);
1366         list_del(&device->driver_list);
1367         usb_serial_bus_deregister(device);
1368         mutex_unlock(&table_lock);
1369 }
1370
1371 /**
1372  * usb_serial_register_drivers - register drivers for a usb-serial module
1373  * @serial_drivers: NULL-terminated array of pointers to drivers to be registered
1374  * @name: name of the usb_driver for this set of @serial_drivers
1375  * @id_table: list of all devices this @serial_drivers set binds to
1376  *
1377  * Registers all the drivers in the @serial_drivers array, and dynamically
1378  * creates a struct usb_driver with the name @name and id_table of @id_table.
1379  */
1380 int usb_serial_register_drivers(struct usb_serial_driver *const serial_drivers[],
1381                                 const char *name,
1382                                 const struct usb_device_id *id_table)
1383 {
1384         int rc;
1385         struct usb_driver *udriver;
1386         struct usb_serial_driver * const *sd;
1387
1388         /*
1389          * udriver must be registered before any of the serial drivers,
1390          * because the store_new_id() routine for the serial drivers (in
1391          * bus.c) probes udriver.
1392          *
1393          * Performance hack: We don't want udriver to be probed until
1394          * the serial drivers are registered, because the probe would
1395          * simply fail for lack of a matching serial driver.
1396          * So we leave udriver's id_table set to NULL until we are all set.
1397          *
1398          * Suspend/resume support is implemented in the usb-serial core,
1399          * so fill in the PM-related fields in udriver.
1400          */
1401         udriver = kzalloc(sizeof(*udriver), GFP_KERNEL);
1402         if (!udriver)
1403                 return -ENOMEM;
1404
1405         udriver->name = name;
1406         udriver->no_dynamic_id = 1;
1407         udriver->supports_autosuspend = 1;
1408         udriver->suspend = usb_serial_suspend;
1409         udriver->resume = usb_serial_resume;
1410         udriver->probe = usb_serial_probe;
1411         udriver->disconnect = usb_serial_disconnect;
1412
1413         /* we only set the reset_resume field if the serial_driver has one */
1414         for (sd = serial_drivers; *sd; ++sd) {
1415                 if ((*sd)->reset_resume) {
1416                         udriver->reset_resume = usb_serial_reset_resume;
1417                         break;
1418                 }
1419         }
1420
1421         rc = usb_register(udriver);
1422         if (rc)
1423                 return rc;
1424
1425         for (sd = serial_drivers; *sd; ++sd) {
1426                 (*sd)->usb_driver = udriver;
1427                 rc = usb_serial_register(*sd);
1428                 if (rc)
1429                         goto failed;
1430         }
1431
1432         /* Now set udriver's id_table and look for matches */
1433         udriver->id_table = id_table;
1434         rc = driver_attach(&udriver->drvwrap.driver);
1435         return 0;
1436
1437  failed:
1438         while (sd-- > serial_drivers)
1439                 usb_serial_deregister(*sd);
1440         usb_deregister(udriver);
1441         return rc;
1442 }
1443 EXPORT_SYMBOL_GPL(usb_serial_register_drivers);
1444
1445 /**
1446  * usb_serial_deregister_drivers - deregister drivers for a usb-serial module
1447  * @serial_drivers: NULL-terminated array of pointers to drivers to be deregistered
1448  *
1449  * Deregisters all the drivers in the @serial_drivers array and deregisters and
1450  * frees the struct usb_driver that was created by the call to
1451  * usb_serial_register_drivers().
1452  */
1453 void usb_serial_deregister_drivers(struct usb_serial_driver *const serial_drivers[])
1454 {
1455         struct usb_driver *udriver = (*serial_drivers)->usb_driver;
1456
1457         for (; *serial_drivers; ++serial_drivers)
1458                 usb_serial_deregister(*serial_drivers);
1459         usb_deregister(udriver);
1460         kfree(udriver);
1461 }
1462 EXPORT_SYMBOL_GPL(usb_serial_deregister_drivers);
1463
1464 /* Module information */
1465 MODULE_AUTHOR(DRIVER_AUTHOR);
1466 MODULE_DESCRIPTION(DRIVER_DESC);
1467 MODULE_LICENSE("GPL");