Pileus Git - ~andy/linux/blob - 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_intf(serial->interface);
 155         usb_put_dev(serial->dev);
 156         kfree(serial);
 157 }
 158
 159 void usb_serial_put(struct usb_serial *serial)
 160 {
 161         kref_put(&serial->kref, destroy_serial);
 162 }
 163
 164 /*****************************************************************************
 165  * Driver tty interface functions
 166  *****************************************************************************/
 167
 168 /**
 169  * serial_install - install tty
 170  * @driver: the driver (USB in our case)
 171  * @tty: the tty being created
 172  *
 173  * Create the termios objects for this tty.  We use the default
 174  * USB serial settings but permit them to be overridden by
 175  * serial->type->init_termios.
 176  *
 177  * This is the first place a new tty gets used.  Hence this is where we
 178  * acquire references to the usb_serial structure and the driver module,
 179  * where we store a pointer to the port, and where we do an autoresume.
 180  * All these actions are reversed in serial_cleanup().
 181  */
 182 static int serial_install(struct tty_driver *driver, struct tty_struct *tty)
 183 {
 184         int idx = tty->index;
 185         struct usb_serial *serial;
 186         struct usb_serial_port *port;
 187         int retval = -ENODEV;
 188
 189         serial = usb_serial_get_by_index(idx);
 190         if (!serial)
 191                 return retval;
 192
 193         port = serial->port[idx - serial->minor];
 194         if (!port)
 195                 goto error_no_port;
 196         if (!try_module_get(serial->type->driver.owner))
 197                 goto error_module_get;
 198
 199         retval = usb_autopm_get_interface(serial->interface);
 200         if (retval)
 201                 goto error_get_interface;
 202
 203         retval = tty_port_install(&port->port, driver, tty);
 204         if (retval)
 205                 goto error_init_termios;
 206
 207         mutex_unlock(&serial->disc_mutex);
 208
 209         /* allow the driver to update the settings */
 210         if (serial->type->init_termios)
 211                 serial->type->init_termios(tty);
 212
 213         tty->driver_data = port;
 214
 215         return retval;
 216
 217  error_init_termios:
 218         usb_autopm_put_interface(serial->interface);
 219  error_get_interface:
 220         module_put(serial->type->driver.owner);
 221  error_module_get:
 222  error_no_port:
 223         usb_serial_put(serial);
 224         mutex_unlock(&serial->disc_mutex);
 225         return retval;
 226 }
 227
 228 static int serial_activate(struct tty_port *tport, struct tty_struct *tty)
 229 {
 230         struct usb_serial_port *port =
 231                 container_of(tport, struct usb_serial_port, port);
 232         struct usb_serial *serial = port->serial;
 233         int retval;
 234
 235         mutex_lock(&serial->disc_mutex);
 236         if (serial->disconnected)
 237                 retval = -ENODEV;
 238         else
 239                 retval = port->serial->type->open(tty, port);
 240         mutex_unlock(&serial->disc_mutex);
 241
 242         if (retval < 0)
 243                 retval = usb_translate_errors(retval);
 244
 245         return retval;
 246 }
 247
 248 static int serial_open(struct tty_struct *tty, struct file *filp)
 249 {
 250         struct usb_serial_port *port = tty->driver_data;
 251
 252         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 253         return tty_port_open(&port->port, tty, filp);
 254 }
 255
 256 /**
 257  * serial_down - shut down hardware
 258  * @tport: tty port to shut down
 259  *
 260  * Shut down a USB serial port unless it is the console.  We never
 261  * shut down the console hardware as it will always be in use. Serialized
 262  * against activate by the tport mutex and kept to matching open/close pairs
 263  * of calls by the ASYNCB_INITIALIZED flag.
 264  */
 265 static void serial_down(struct tty_port *tport)
 266 {
 267         struct usb_serial_port *port =
 268                 container_of(tport, struct usb_serial_port, port);
 269         struct usb_serial_driver *drv = port->serial->type;
 270         /*
 271          * The console is magical.  Do not hang up the console hardware
 272          * or there will be tears.
 273          */
 274         if (port->port.console)
 275                 return;
 276         if (drv->close)
 277                 drv->close(port);
 278 }
 279
 280 static void serial_hangup(struct tty_struct *tty)
 281 {
 282         struct usb_serial_port *port = tty->driver_data;
 283
 284         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 285         tty_port_hangup(&port->port);
 286 }
 287
 288 static void serial_close(struct tty_struct *tty, struct file *filp)
 289 {
 290         struct usb_serial_port *port = tty->driver_data;
 291
 292         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 293         tty_port_close(&port->port, tty, filp);
 294 }
 295
 296 /**
 297  * serial_cleanup - free resources post close/hangup
 298  * @port: port to free up
 299  *
 300  * Do the resource freeing and refcount dropping for the port.
 301  * Avoid freeing the console.
 302  *
 303  * Called asynchronously after the last tty kref is dropped.
 304  */
 305 static void serial_cleanup(struct tty_struct *tty)
 306 {
 307         struct usb_serial_port *port = tty->driver_data;
 308         struct usb_serial *serial;
 309         struct module *owner;
 310
 311         /* The console is magical.  Do not hang up the console hardware
 312          * or there will be tears.
 313          */
 314         if (port->port.console)
 315                 return;
 316
 317         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 318
 319         tty->driver_data = NULL;
 320
 321         serial = port->serial;
 322         owner = serial->type->driver.owner;
 323
 324         mutex_lock(&serial->disc_mutex);
 325         if (!serial->disconnected)
 326                 usb_autopm_put_interface(serial->interface);
 327         mutex_unlock(&serial->disc_mutex);
 328
 329         usb_serial_put(serial);
 330         module_put(owner);
 331 }
 332
 333 static int serial_write(struct tty_struct *tty, const unsigned char *buf,
 334                                                                 int count)
 335 {
 336         struct usb_serial_port *port = tty->driver_data;
 337         int retval = -ENODEV;
 338
 339         if (port->serial->dev->state == USB_STATE_NOTATTACHED)
 340                 goto exit;
 341
 342         dev_dbg(tty->dev, "%s - port %d, %d byte(s)\n", __func__,
 343                 port->number, count);
 344
 345         /* pass on to the driver specific version of this function */
 346         retval = port->serial->type->write(tty, port, buf, count);
 347         if (retval < 0)
 348                 retval = usb_translate_errors(retval);
 349 exit:
 350         return retval;
 351 }
 352
 353 static int serial_write_room(struct tty_struct *tty)
 354 {
 355         struct usb_serial_port *port = tty->driver_data;
 356
 357         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 358         /* pass on to the driver specific version of this function */
 359         return port->serial->type->write_room(tty);
 360 }
 361
 362 static int serial_chars_in_buffer(struct tty_struct *tty)
 363 {
 364         struct usb_serial_port *port = tty->driver_data;
 365         struct usb_serial *serial = port->serial;
 366         int count = 0;
 367
 368         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 369
 370         mutex_lock(&serial->disc_mutex);
 371         /* if the device was unplugged then any remaining characters
 372            fell out of the connector ;) */
 373         if (serial->disconnected)
 374                 count = 0;
 375         else
 376                 count = serial->type->chars_in_buffer(tty);
 377         mutex_unlock(&serial->disc_mutex);
 378
 379         return count;
 380 }
 381
 382 static void serial_throttle(struct tty_struct *tty)
 383 {
 384         struct usb_serial_port *port = tty->driver_data;
 385
 386         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 387
 388         /* pass on to the driver specific version of this function */
 389         if (port->serial->type->throttle)
 390                 port->serial->type->throttle(tty);
 391 }
 392
 393 static void serial_unthrottle(struct tty_struct *tty)
 394 {
 395         struct usb_serial_port *port = tty->driver_data;
 396
 397         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 398
 399         /* pass on to the driver specific version of this function */
 400         if (port->serial->type->unthrottle)
 401                 port->serial->type->unthrottle(tty);
 402 }
 403
 404 static int serial_ioctl(struct tty_struct *tty,
 405                                         unsigned int cmd, unsigned long arg)
 406 {
 407         struct usb_serial_port *port = tty->driver_data;
 408         int retval = -ENODEV;
 409
 410         dev_dbg(tty->dev, "%s - port %d, cmd 0x%.4x\n", __func__,
 411                 port->number, cmd);
 412
 413         /* pass on to the driver specific version of this function
 414            if it is available */
 415         if (port->serial->type->ioctl) {
 416                 retval = port->serial->type->ioctl(tty, cmd, arg);
 417         } else
 418                 retval = -ENOIOCTLCMD;
 419         return retval;
 420 }
 421
 422 static void serial_set_termios(struct tty_struct *tty, struct ktermios *old)
 423 {
 424         struct usb_serial_port *port = tty->driver_data;
 425
 426         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 427
 428         /* pass on to the driver specific version of this function
 429            if it is available */
 430         if (port->serial->type->set_termios)
 431                 port->serial->type->set_termios(tty, port, old);
 432         else
 433                 tty_termios_copy_hw(&tty->termios, old);
 434 }
 435
 436 static int serial_break(struct tty_struct *tty, int break_state)
 437 {
 438         struct usb_serial_port *port = tty->driver_data;
 439
 440         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 441
 442         /* pass on to the driver specific version of this function
 443            if it is available */
 444         if (port->serial->type->break_ctl)
 445                 port->serial->type->break_ctl(tty, break_state);
 446         return 0;
 447 }
 448
 449 static int serial_proc_show(struct seq_file *m, void *v)
 450 {
 451         struct usb_serial *serial;
 452         int i;
 453         char tmp[40];
 454
 455         seq_puts(m, "usbserinfo:1.0 driver:2.0\n");
 456         for (i = 0; i < SERIAL_TTY_MINORS; ++i) {
 457                 serial = usb_serial_get_by_index(i);
 458                 if (serial == NULL)
 459                         continue;
 460
 461                 seq_printf(m, "%d:", i);
 462                 if (serial->type->driver.owner)
 463                         seq_printf(m, " module:%s",
 464                                 module_name(serial->type->driver.owner));
 465                 seq_printf(m, " name:\"%s\"",
 466                                 serial->type->description);
 467                 seq_printf(m, " vendor:%04x product:%04x",
 468                         le16_to_cpu(serial->dev->descriptor.idVendor),
 469                         le16_to_cpu(serial->dev->descriptor.idProduct));
 470                 seq_printf(m, " num_ports:%d", serial->num_ports);
 471                 seq_printf(m, " port:%d", i - serial->minor + 1);
 472                 usb_make_path(serial->dev, tmp, sizeof(tmp));
 473                 seq_printf(m, " path:%s", tmp);
 474
 475                 seq_putc(m, '\n');
 476                 usb_serial_put(serial);
 477                 mutex_unlock(&serial->disc_mutex);
 478         }
 479         return 0;
 480 }
 481
 482 static int serial_proc_open(struct inode *inode, struct file *file)
 483 {
 484         return single_open(file, serial_proc_show, NULL);
 485 }
 486
 487 static const struct file_operations serial_proc_fops = {
 488         .owner          = THIS_MODULE,
 489         .open           = serial_proc_open,
 490         .read           = seq_read,
 491         .llseek         = seq_lseek,
 492         .release        = single_release,
 493 };
 494
 495 static int serial_tiocmget(struct tty_struct *tty)
 496 {
 497         struct usb_serial_port *port = tty->driver_data;
 498
 499         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 500
 501         if (port->serial->type->tiocmget)
 502                 return port->serial->type->tiocmget(tty);
 503         return -EINVAL;
 504 }
 505
 506 static int serial_tiocmset(struct tty_struct *tty,
 507                             unsigned int set, unsigned int clear)
 508 {
 509         struct usb_serial_port *port = tty->driver_data;
 510
 511         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 512
 513         if (port->serial->type->tiocmset)
 514                 return port->serial->type->tiocmset(tty, set, clear);
 515         return -EINVAL;
 516 }
 517
 518 static int serial_get_icount(struct tty_struct *tty,
 519                                 struct serial_icounter_struct *icount)
 520 {
 521         struct usb_serial_port *port = tty->driver_data;
 522
 523         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 524
 525         if (port->serial->type->get_icount)
 526                 return port->serial->type->get_icount(tty, icount);
 527         return -EINVAL;
 528 }
 529
 530 /*
 531  * We would be calling tty_wakeup here, but unfortunately some line
 532  * disciplines have an annoying habit of calling tty->write from
 533  * the write wakeup callback (e.g. n_hdlc.c).
 534  */
 535 void usb_serial_port_softint(struct usb_serial_port *port)
 536 {
 537         schedule_work(&port->work);
 538 }
 539 EXPORT_SYMBOL_GPL(usb_serial_port_softint);
 540
 541 static void usb_serial_port_work(struct work_struct *work)
 542 {
 543         struct usb_serial_port *port =
 544                 container_of(work, struct usb_serial_port, work);
 545         struct tty_struct *tty;
 546
 547         tty = tty_port_tty_get(&port->port);
 548         if (!tty)
 549                 return;
 550
 551         dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
 552
 553         tty_wakeup(tty);
 554         tty_kref_put(tty);
 555 }
 556
 557 static void kill_traffic(struct usb_serial_port *port)
 558 {
 559         int i;
 560
 561         for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)
 562                 usb_kill_urb(port->read_urbs[i]);
 563         for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
 564                 usb_kill_urb(port->write_urbs[i]);
 565         /*
 566          * This is tricky.
 567          * Some drivers submit the read_urb in the
 568          * handler for the write_urb or vice versa
 569          * this order determines the order in which
 570          * usb_kill_urb() must be used to reliably
 571          * kill the URBs. As it is unknown here,
 572          * both orders must be used in turn.
 573          * The call below is not redundant.
 574          */
 575         usb_kill_urb(port->read_urb);
 576         usb_kill_urb(port->interrupt_in_urb);
 577         usb_kill_urb(port->interrupt_out_urb);
 578 }
 579
 580 static void port_release(struct device *dev)
 581 {
 582         struct usb_serial_port *port = to_usb_serial_port(dev);
 583         int i;
 584
 585         dev_dbg(dev, "%s\n", __func__);
 586
 587         /*
 588          * Stop all the traffic before cancelling the work, so that
 589          * nobody will restart it by calling usb_serial_port_softint.
 590          */
 591         kill_traffic(port);
 592         cancel_work_sync(&port->work);
 593
 594         usb_free_urb(port->interrupt_in_urb);
 595         usb_free_urb(port->interrupt_out_urb);
 596         for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
 597                 usb_free_urb(port->read_urbs[i]);
 598                 kfree(port->bulk_in_buffers[i]);
 599         }
 600         for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) {
 601                 usb_free_urb(port->write_urbs[i]);
 602                 kfree(port->bulk_out_buffers[i]);
 603         }
 604         kfifo_free(&port->write_fifo);
 605         kfree(port->interrupt_in_buffer);
 606         kfree(port->interrupt_out_buffer);
 607         tty_port_destroy(&port->port);
 608         kfree(port);
 609 }
 610
 611 static struct usb_serial *create_serial(struct usb_device *dev,
 612                                         struct usb_interface *interface,
 613                                         struct usb_serial_driver *driver)
 614 {
 615         struct usb_serial *serial;
 616
 617         serial = kzalloc(sizeof(*serial), GFP_KERNEL);
 618         if (!serial) {
 619                 dev_err(&dev->dev, "%s - out of memory\n", __func__);
 620                 return NULL;
 621         }
 622         serial->dev = usb_get_dev(dev);
 623         serial->type = driver;
 624         serial->interface = usb_get_intf(interface);
 625         kref_init(&serial->kref);
 626         mutex_init(&serial->disc_mutex);
 627         serial->minor = SERIAL_TTY_NO_MINOR;
 628
 629         return serial;
 630 }
 631
 632 static const struct usb_device_id *match_dynamic_id(struct usb_interface *intf,
 633                                             struct usb_serial_driver *drv)
 634 {
 635         struct usb_dynid *dynid;
 636
 637         spin_lock(&drv->dynids.lock);
 638         list_for_each_entry(dynid, &drv->dynids.list, node) {
 639                 if (usb_match_one_id(intf, &dynid->id)) {
 640                         spin_unlock(&drv->dynids.lock);
 641                         return &dynid->id;
 642                 }
 643         }
 644         spin_unlock(&drv->dynids.lock);
 645         return NULL;
 646 }
 647
 648 static const struct usb_device_id *get_iface_id(struct usb_serial_driver *drv,
 649                                                 struct usb_interface *intf)
 650 {
 651         const struct usb_device_id *id;
 652
 653         id = usb_match_id(intf, drv->id_table);
 654         if (id) {
 655                 dev_dbg(&intf->dev, "static descriptor matches\n");
 656                 goto exit;
 657         }
 658         id = match_dynamic_id(intf, drv);
 659         if (id)
 660                 dev_dbg(&intf->dev, "dynamic descriptor matches\n");
 661 exit:
 662         return id;
 663 }
 664
 665 /* Caller must hold table_lock */
 666 static struct usb_serial_driver *search_serial_device(
 667                                         struct usb_interface *iface)
 668 {
 669         const struct usb_device_id *id = NULL;
 670         struct usb_serial_driver *drv;
 671         struct usb_driver *driver = to_usb_driver(iface->dev.driver);
 672
 673         /* Check if the usb id matches a known device */
 674         list_for_each_entry(drv, &usb_serial_driver_list, driver_list) {
 675                 if (drv->usb_driver == driver)
 676                         id = get_iface_id(drv, iface);
 677                 if (id)
 678                         return drv;
 679         }
 680
 681         return NULL;
 682 }
 683
 684 static int serial_carrier_raised(struct tty_port *port)
 685 {
 686         struct usb_serial_port *p = container_of(port, struct usb_serial_port, port);
 687         struct usb_serial_driver *drv = p->serial->type;
 688
 689         if (drv->carrier_raised)
 690                 return drv->carrier_raised(p);
 691         /* No carrier control - don't block */
 692         return 1;
 693 }
 694
 695 static void serial_dtr_rts(struct tty_port *port, int on)
 696 {
 697         struct usb_serial_port *p = container_of(port, struct usb_serial_port, port);
 698         struct usb_serial *serial = p->serial;
 699         struct usb_serial_driver *drv = serial->type;
 700
 701         if (!drv->dtr_rts)
 702                 return;
 703         /*
 704          * Work-around bug in the tty-layer which can result in dtr_rts
 705          * being called after a disconnect (and tty_unregister_device
 706          * has returned). Remove once bug has been squashed.
 707          */
 708         mutex_lock(&serial->disc_mutex);
 709         if (!serial->disconnected)
 710                 drv->dtr_rts(p, on);
 711         mutex_unlock(&serial->disc_mutex);
 712 }
 713
 714 static const struct tty_port_operations serial_port_ops = {
 715         .carrier_raised = serial_carrier_raised,
 716         .dtr_rts = serial_dtr_rts,
 717         .activate = serial_activate,
 718         .shutdown = serial_down,
 719 };
 720
 721 static int usb_serial_probe(struct usb_interface *interface,
 722                                const struct usb_device_id *id)
 723 {
 724         struct device *ddev = &interface->dev;
 725         struct usb_device *dev = interface_to_usbdev(interface);
 726         struct usb_serial *serial = NULL;
 727         struct usb_serial_port *port;
 728         struct usb_host_interface *iface_desc;
 729         struct usb_endpoint_descriptor *endpoint;
 730         struct usb_endpoint_descriptor *interrupt_in_endpoint[MAX_NUM_PORTS];
 731         struct usb_endpoint_descriptor *interrupt_out_endpoint[MAX_NUM_PORTS];
 732         struct usb_endpoint_descriptor *bulk_in_endpoint[MAX_NUM_PORTS];
 733         struct usb_endpoint_descriptor *bulk_out_endpoint[MAX_NUM_PORTS];
 734         struct usb_serial_driver *type = NULL;
 735         int retval;
 736         unsigned int minor;
 737         int buffer_size;
 738         int i;
 739         int j;
 740         int num_interrupt_in = 0;
 741         int num_interrupt_out = 0;
 742         int num_bulk_in = 0;
 743         int num_bulk_out = 0;
 744         int num_ports = 0;
 745         int max_endpoints;
 746
 747         mutex_lock(&table_lock);
 748         type = search_serial_device(interface);
 749         if (!type) {
 750                 mutex_unlock(&table_lock);
 751                 dev_dbg(ddev, "none matched\n");
 752                 return -ENODEV;
 753         }
 754
 755         if (!try_module_get(type->driver.owner)) {
 756                 mutex_unlock(&table_lock);
 757                 dev_err(ddev, "module get failed, exiting\n");
 758                 return -EIO;
 759         }
 760         mutex_unlock(&table_lock);
 761
 762         serial = create_serial(dev, interface, type);
 763         if (!serial) {
 764                 module_put(type->driver.owner);
 765                 dev_err(ddev, "%s - out of memory\n", __func__);
 766                 return -ENOMEM;
 767         }
 768
 769         /* if this device type has a probe function, call it */
 770         if (type->probe) {
 771                 const struct usb_device_id *id;
 772
 773                 id = get_iface_id(type, interface);
 774                 retval = type->probe(serial, id);
 775
 776                 if (retval) {
 777                         dev_dbg(ddev, "sub driver rejected device\n");
 778                         usb_serial_put(serial);
 779                         module_put(type->driver.owner);
 780                         return retval;
 781                 }
 782         }
 783
 784         /* descriptor matches, let's find the endpoints needed */
 785         /* check out the endpoints */
 786         iface_desc = interface->cur_altsetting;
 787         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 788                 endpoint = &iface_desc->endpoint[i].desc;
 789
 790                 if (usb_endpoint_is_bulk_in(endpoint)) {
 791                         /* we found a bulk in endpoint */
 792                         dev_dbg(ddev, "found bulk in on endpoint %d\n", i);
 793                         bulk_in_endpoint[num_bulk_in] = endpoint;
 794                         ++num_bulk_in;
 795                 }
 796
 797                 if (usb_endpoint_is_bulk_out(endpoint)) {
 798                         /* we found a bulk out endpoint */
 799                         dev_dbg(ddev, "found bulk out on endpoint %d\n", i);
 800                         bulk_out_endpoint[num_bulk_out] = endpoint;
 801                         ++num_bulk_out;
 802                 }
 803
 804                 if (usb_endpoint_is_int_in(endpoint)) {
 805                         /* we found a interrupt in endpoint */
 806                         dev_dbg(ddev, "found interrupt in on endpoint %d\n", i);
 807                         interrupt_in_endpoint[num_interrupt_in] = endpoint;
 808                         ++num_interrupt_in;
 809                 }
 810
 811                 if (usb_endpoint_is_int_out(endpoint)) {
 812                         /* we found an interrupt out endpoint */
 813                         dev_dbg(ddev, "found interrupt out on endpoint %d\n", i);
 814                         interrupt_out_endpoint[num_interrupt_out] = endpoint;
 815                         ++num_interrupt_out;
 816                 }
 817         }
 818
 819 #if defined(CONFIG_USB_SERIAL_PL2303) || defined(CONFIG_USB_SERIAL_PL2303_MODULE)
 820         /* BEGIN HORRIBLE HACK FOR PL2303 */
 821         /* this is needed due to the looney way its endpoints are set up */
 822         if (((le16_to_cpu(dev->descriptor.idVendor) == PL2303_VENDOR_ID) &&
 823              (le16_to_cpu(dev->descriptor.idProduct) == PL2303_PRODUCT_ID)) ||
 824             ((le16_to_cpu(dev->descriptor.idVendor) == ATEN_VENDOR_ID) &&
 825              (le16_to_cpu(dev->descriptor.idProduct) == ATEN_PRODUCT_ID)) ||
 826             ((le16_to_cpu(dev->descriptor.idVendor) == ALCOR_VENDOR_ID) &&
 827              (le16_to_cpu(dev->descriptor.idProduct) == ALCOR_PRODUCT_ID)) ||
 828             ((le16_to_cpu(dev->descriptor.idVendor) == SIEMENS_VENDOR_ID) &&
 829              (le16_to_cpu(dev->descriptor.idProduct) == SIEMENS_PRODUCT_ID_EF81))) {
 830                 if (interface != dev->actconfig->interface[0]) {
 831                         /* check out the endpoints of the other interface*/
 832                         iface_desc = dev->actconfig->interface[0]->cur_altsetting;
 833                         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 834                                 endpoint = &iface_desc->endpoint[i].desc;
 835                                 if (usb_endpoint_is_int_in(endpoint)) {
 836                                         /* we found a interrupt in endpoint */
 837                                         dev_dbg(ddev, "found interrupt in for Prolific device on separate interface\n");
 838                                         interrupt_in_endpoint[num_interrupt_in] = endpoint;
 839                                         ++num_interrupt_in;
 840                                 }
 841                         }
 842                 }
 843
 844                 /* Now make sure the PL-2303 is configured correctly.
 845                  * If not, give up now and hope this hack will work
 846                  * properly during a later invocation of usb_serial_probe
 847                  */
 848                 if (num_bulk_in == 0 || num_bulk_out == 0) {
 849                         dev_info(ddev, "PL-2303 hack: descriptors matched but endpoints did not\n");
 850                         usb_serial_put(serial);
 851                         module_put(type->driver.owner);
 852                         return -ENODEV;
 853                 }
 854         }
 855         /* END HORRIBLE HACK FOR PL2303 */
 856 #endif
 857
 858 #ifdef CONFIG_USB_SERIAL_GENERIC
 859         if (type == &usb_serial_generic_device) {
 860                 num_ports = num_bulk_out;
 861                 if (num_ports == 0) {
 862                         dev_err(ddev, "Generic device with no bulk out, not allowed.\n");
 863                         usb_serial_put(serial);
 864                         module_put(type->driver.owner);
 865                         return -EIO;
 866                 }
 867                 dev_info(ddev, "The \"generic\" usb-serial driver is only for testing and one-off prototypes.\n");
 868                 dev_info(ddev, "Tell linux-usb@vger.kernel.org to add your device to a proper driver.\n");
 869         }
 870 #endif
 871         if (!num_ports) {
 872                 /* if this device type has a calc_num_ports function, call it */
 873                 if (type->calc_num_ports)
 874                         num_ports = type->calc_num_ports(serial);
 875                 if (!num_ports)
 876                         num_ports = type->num_ports;
 877         }
 878
 879         serial->num_ports = num_ports;
 880         serial->num_bulk_in = num_bulk_in;
 881         serial->num_bulk_out = num_bulk_out;
 882         serial->num_interrupt_in = num_interrupt_in;
 883         serial->num_interrupt_out = num_interrupt_out;
 884
 885         /* found all that we need */
 886         dev_info(ddev, "%s converter detected\n", type->description);
 887
 888         /* create our ports, we need as many as the max endpoints */
 889         /* we don't use num_ports here because some devices have more
 890            endpoint pairs than ports */
 891         max_endpoints = max(num_bulk_in, num_bulk_out);
 892         max_endpoints = max(max_endpoints, num_interrupt_in);
 893         max_endpoints = max(max_endpoints, num_interrupt_out);
 894         max_endpoints = max(max_endpoints, (int)serial->num_ports);
 895         serial->num_port_pointers = max_endpoints;
 896
 897         dev_dbg(ddev, "setting up %d port structures for this device", max_endpoints);
 898         for (i = 0; i < max_endpoints; ++i) {
 899                 port = kzalloc(sizeof(struct usb_serial_port), GFP_KERNEL);
 900                 if (!port)
 901                         goto probe_error;
 902                 tty_port_init(&port->port);
 903                 port->port.ops = &serial_port_ops;
 904                 port->serial = serial;
 905                 spin_lock_init(&port->lock);
 906                 init_waitqueue_head(&port->delta_msr_wait);
 907                 /* Keep this for private driver use for the moment but
 908                    should probably go away */
 909                 INIT_WORK(&port->work, usb_serial_port_work);
 910                 serial->port[i] = port;
 911                 port->dev.parent = &interface->dev;
 912                 port->dev.driver = NULL;
 913                 port->dev.bus = &usb_serial_bus_type;
 914                 port->dev.release = &port_release;
 915                 device_initialize(&port->dev);
 916         }
 917
 918         /* set up the endpoint information */
 919         for (i = 0; i < num_bulk_in; ++i) {
 920                 endpoint = bulk_in_endpoint[i];
 921                 port = serial->port[i];
 922                 buffer_size = max_t(int, serial->type->bulk_in_size,
 923                                 usb_endpoint_maxp(endpoint));
 924                 port->bulk_in_size = buffer_size;
 925                 port->bulk_in_endpointAddress = endpoint->bEndpointAddress;
 926
 927                 for (j = 0; j < ARRAY_SIZE(port->read_urbs); ++j) {
 928                         set_bit(j, &port->read_urbs_free);
 929                         port->read_urbs[j] = usb_alloc_urb(0, GFP_KERNEL);
 930                         if (!port->read_urbs[j]) {
 931                                 dev_err(ddev, "No free urbs available\n");
 932                                 goto probe_error;
 933                         }
 934                         port->bulk_in_buffers[j] = kmalloc(buffer_size,
 935                                                                 GFP_KERNEL);
 936                         if (!port->bulk_in_buffers[j]) {
 937                                 dev_err(ddev, "Couldn't allocate bulk_in_buffer\n");
 938                                 goto probe_error;
 939                         }
 940                         usb_fill_bulk_urb(port->read_urbs[j], dev,
 941                                         usb_rcvbulkpipe(dev,
 942                                                 endpoint->bEndpointAddress),
 943                                         port->bulk_in_buffers[j], buffer_size,
 944                                         serial->type->read_bulk_callback,
 945                                         port);
 946                 }
 947
 948                 port->read_urb = port->read_urbs[0];
 949                 port->bulk_in_buffer = port->bulk_in_buffers[0];
 950         }
 951
 952         for (i = 0; i < num_bulk_out; ++i) {
 953                 endpoint = bulk_out_endpoint[i];
 954                 port = serial->port[i];
 955                 if (kfifo_alloc(&port->write_fifo, PAGE_SIZE, GFP_KERNEL))
 956                         goto probe_error;
 957                 buffer_size = serial->type->bulk_out_size;
 958                 if (!buffer_size)
 959                         buffer_size = usb_endpoint_maxp(endpoint);
 960                 port->bulk_out_size = buffer_size;
 961                 port->bulk_out_endpointAddress = endpoint->bEndpointAddress;
 962
 963                 for (j = 0; j < ARRAY_SIZE(port->write_urbs); ++j) {
 964                         set_bit(j, &port->write_urbs_free);
 965                         port->write_urbs[j] = usb_alloc_urb(0, GFP_KERNEL);
 966                         if (!port->write_urbs[j]) {
 967                                 dev_err(ddev, "No free urbs available\n");
 968                                 goto probe_error;
 969                         }
 970                         port->bulk_out_buffers[j] = kmalloc(buffer_size,
 971                                                                 GFP_KERNEL);
 972                         if (!port->bulk_out_buffers[j]) {
 973                                 dev_err(ddev, "Couldn't allocate bulk_out_buffer\n");
 974                                 goto probe_error;
 975                         }
 976                         usb_fill_bulk_urb(port->write_urbs[j], dev,
 977                                         usb_sndbulkpipe(dev,
 978                                                 endpoint->bEndpointAddress),
 979                                         port->bulk_out_buffers[j], buffer_size,
 980                                         serial->type->write_bulk_callback,
 981                                         port);
 982                 }
 983
 984                 port->write_urb = port->write_urbs[0];
 985                 port->bulk_out_buffer = port->bulk_out_buffers[0];
 986         }
 987
 988         if (serial->type->read_int_callback) {
 989                 for (i = 0; i < num_interrupt_in; ++i) {
 990                         endpoint = interrupt_in_endpoint[i];
 991                         port = serial->port[i];
 992                         port->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 993                         if (!port->interrupt_in_urb) {
 994                                 dev_err(ddev, "No free urbs available\n");
 995                                 goto probe_error;
 996                         }
 997                         buffer_size = usb_endpoint_maxp(endpoint);
 998                         port->interrupt_in_endpointAddress =
 999                                                 endpoint->bEndpointAddress;
1000                         port->interrupt_in_buffer = kmalloc(buffer_size,
1001                                                                 GFP_KERNEL);
1002                         if (!port->interrupt_in_buffer) {
1003                                 dev_err(ddev, "Couldn't allocate interrupt_in_buffer\n");
1004                                 goto probe_error;
1005                         }
1006                         usb_fill_int_urb(port->interrupt_in_urb, dev,
1007                                 usb_rcvintpipe(dev,
1008                                                 endpoint->bEndpointAddress),
1009                                 port->interrupt_in_buffer, buffer_size,
1010                                 serial->type->read_int_callback, port,
1011                                 endpoint->bInterval);
1012                 }
1013         } else if (num_interrupt_in) {
1014                 dev_dbg(ddev, "The device claims to support interrupt in transfers, but read_int_callback is not defined\n");
1015         }
1016
1017         if (serial->type->write_int_callback) {
1018                 for (i = 0; i < num_interrupt_out; ++i) {
1019                         endpoint = interrupt_out_endpoint[i];
1020                         port = serial->port[i];
1021                         port->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
1022                         if (!port->interrupt_out_urb) {
1023                                 dev_err(ddev, "No free urbs available\n");
1024                                 goto probe_error;
1025                         }
1026                         buffer_size = usb_endpoint_maxp(endpoint);
1027                         port->interrupt_out_size = buffer_size;
1028                         port->interrupt_out_endpointAddress =
1029                                                 endpoint->bEndpointAddress;
1030                         port->interrupt_out_buffer = kmalloc(buffer_size,
1031                                                                 GFP_KERNEL);
1032                         if (!port->interrupt_out_buffer) {
1033                                 dev_err(ddev, "Couldn't allocate interrupt_out_buffer\n");
1034                                 goto probe_error;
1035                         }
1036                         usb_fill_int_urb(port->interrupt_out_urb, dev,
1037                                 usb_sndintpipe(dev,
1038                                                   endpoint->bEndpointAddress),
1039                                 port->interrupt_out_buffer, buffer_size,
1040                                 serial->type->write_int_callback, port,
1041                                 endpoint->bInterval);
1042                 }
1043         } else if (num_interrupt_out) {
1044                 dev_dbg(ddev, "The device claims to support interrupt out transfers, but write_int_callback is not defined\n");
1045         }
1046
1047         usb_set_intfdata(interface, serial);
1048
1049         /* if this device type has an attach function, call it */
1050         if (type->attach) {
1051                 retval = type->attach(serial);
1052                 if (retval < 0)
1053                         goto probe_error;
1054                 serial->attached = 1;
1055                 if (retval > 0) {
1056                         /* quietly accept this device, but don't bind to a
1057                            serial port as it's about to disappear */
1058                         serial->num_ports = 0;
1059                         goto exit;
1060                 }
1061         } else {
1062                 serial->attached = 1;
1063         }
1064
1065         /* Avoid race with tty_open and serial_install by setting the
1066          * disconnected flag and not clearing it until all ports have been
1067          * registered.
1068          */
1069         serial->disconnected = 1;
1070
1071         if (get_free_serial(serial, num_ports, &minor) == NULL) {
1072                 dev_err(ddev, "No more free serial devices\n");
1073                 goto probe_error;
1074         }
1075         serial->minor = minor;
1076
1077         /* register all of the individual ports with the driver core */
1078         for (i = 0; i < num_ports; ++i) {
1079                 port = serial->port[i];
1080                 dev_set_name(&port->dev, "ttyUSB%d", port->number);
1081                 dev_dbg(ddev, "registering %s", dev_name(&port->dev));
1082                 device_enable_async_suspend(&port->dev);
1083
1084                 retval = device_add(&port->dev);
1085                 if (retval)
1086                         dev_err(ddev, "Error registering port device, continuing\n");
1087         }
1088
1089         serial->disconnected = 0;
1090
1091         usb_serial_console_init(minor);
1092 exit:
1093         module_put(type->driver.owner);
1094         return 0;
1095
1096 probe_error:
1097         usb_serial_put(serial);
1098         module_put(type->driver.owner);
1099         return -EIO;
1100 }
1101
1102 static void usb_serial_disconnect(struct usb_interface *interface)
1103 {
1104         int i;
1105         struct usb_serial *serial = usb_get_intfdata(interface);
1106         struct device *dev = &interface->dev;
1107         struct usb_serial_port *port;
1108
1109         usb_serial_console_disconnect(serial);
1110
1111         mutex_lock(&serial->disc_mutex);
1112         /* must set a flag, to signal subdrivers */
1113         serial->disconnected = 1;
1114         mutex_unlock(&serial->disc_mutex);
1115
1116         for (i = 0; i < serial->num_ports; ++i) {
1117                 port = serial->port[i];
1118                 if (port) {
1119                         struct tty_struct *tty = tty_port_tty_get(&port->port);
1120                         if (tty) {
1121                                 tty_vhangup(tty);
1122                                 tty_kref_put(tty);
1123                         }
1124                         kill_traffic(port);
1125                         cancel_work_sync(&port->work);
1126                         if (device_is_registered(&port->dev))
1127                                 device_del(&port->dev);
1128                 }
1129         }
1130         serial->type->disconnect(serial);
1131
1132         /* let the last holder of this object cause it to be cleaned up */
1133         usb_serial_put(serial);
1134         dev_info(dev, "device disconnected\n");
1135 }
1136
1137 int usb_serial_suspend(struct usb_interface *intf, pm_message_t message)
1138 {
1139         struct usb_serial *serial = usb_get_intfdata(intf);
1140         struct usb_serial_port *port;
1141         int i, r = 0;
1142
1143         serial->suspending = 1;
1144
1145         if (serial->type->suspend) {
1146                 r = serial->type->suspend(serial, message);
1147                 if (r < 0) {
1148                         serial->suspending = 0;
1149                         goto err_out;
1150                 }
1151         }
1152
1153         for (i = 0; i < serial->num_ports; ++i) {
1154                 port = serial->port[i];
1155                 if (port)
1156                         kill_traffic(port);
1157         }
1158
1159 err_out:
1160         return r;
1161 }
1162 EXPORT_SYMBOL(usb_serial_suspend);
1163
1164 int usb_serial_resume(struct usb_interface *intf)
1165 {
1166         struct usb_serial *serial = usb_get_intfdata(intf);
1167         int rv;
1168
1169         serial->suspending = 0;
1170         if (serial->type->resume)
1171                 rv = serial->type->resume(serial);
1172         else
1173                 rv = usb_serial_generic_resume(serial);
1174
1175         return rv;
1176 }
1177 EXPORT_SYMBOL(usb_serial_resume);
1178
1179 static int usb_serial_reset_resume(struct usb_interface *intf)
1180 {
1181         struct usb_serial *serial = usb_get_intfdata(intf);
1182         int rv;
1183
1184         serial->suspending = 0;
1185         if (serial->type->reset_resume)
1186                 rv = serial->type->reset_resume(serial);
1187         else {
1188                 rv = -EOPNOTSUPP;
1189                 intf->needs_binding = 1;
1190         }
1191
1192         return rv;
1193 }
1194
1195 static const struct tty_operations serial_ops = {
1196         .open =                 serial_open,
1197         .close =                serial_close,
1198         .write =                serial_write,
1199         .hangup =               serial_hangup,
1200         .write_room =           serial_write_room,
1201         .ioctl =                serial_ioctl,
1202         .set_termios =          serial_set_termios,
1203         .throttle =             serial_throttle,
1204         .unthrottle =           serial_unthrottle,
1205         .break_ctl =            serial_break,
1206         .chars_in_buffer =      serial_chars_in_buffer,
1207         .tiocmget =             serial_tiocmget,
1208         .tiocmset =             serial_tiocmset,
1209         .get_icount =           serial_get_icount,
1210         .cleanup =              serial_cleanup,
1211         .install =              serial_install,
1212         .proc_fops =            &serial_proc_fops,
1213 };
1214
1215
1216 struct tty_driver *usb_serial_tty_driver;
1217
1218 /* Driver structure we register with the USB core */
1219 static struct usb_driver usb_serial_driver = {
1220         .name =         "usbserial",
1221         .probe =        usb_serial_probe,
1222         .disconnect =   usb_serial_disconnect,
1223         .suspend =      usb_serial_suspend,
1224         .resume =       usb_serial_resume,
1225         .no_dynamic_id =        1,
1226         .supports_autosuspend = 1,
1227 };
1228
1229 static int __init usb_serial_init(void)
1230 {
1231         int i;
1232         int result;
1233
1234         usb_serial_tty_driver = alloc_tty_driver(SERIAL_TTY_MINORS);
1235         if (!usb_serial_tty_driver)
1236                 return -ENOMEM;
1237
1238         /* Initialize our global data */
1239         for (i = 0; i < SERIAL_TTY_MINORS; ++i)
1240                 serial_table[i] = NULL;
1241
1242         result = bus_register(&usb_serial_bus_type);
1243         if (result) {
1244                 pr_err("%s - registering bus driver failed\n", __func__);
1245                 goto exit_bus;
1246         }
1247
1248         usb_serial_tty_driver->driver_name = "usbserial";
1249         usb_serial_tty_driver->name = "ttyUSB";
1250         usb_serial_tty_driver->major = SERIAL_TTY_MAJOR;
1251         usb_serial_tty_driver->minor_start = 0;
1252         usb_serial_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
1253         usb_serial_tty_driver->subtype = SERIAL_TYPE_NORMAL;
1254         usb_serial_tty_driver->flags = TTY_DRIVER_REAL_RAW |
1255                                                 TTY_DRIVER_DYNAMIC_DEV;
1256         usb_serial_tty_driver->init_termios = tty_std_termios;
1257         usb_serial_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD
1258                                                         | HUPCL | CLOCAL;
1259         usb_serial_tty_driver->init_termios.c_ispeed = 9600;
1260         usb_serial_tty_driver->init_termios.c_ospeed = 9600;
1261         tty_set_operations(usb_serial_tty_driver, &serial_ops);
1262         result = tty_register_driver(usb_serial_tty_driver);
1263         if (result) {
1264                 pr_err("%s - tty_register_driver failed\n", __func__);
1265                 goto exit_reg_driver;
1266         }
1267
1268         /* register the USB driver */
1269         result = usb_register(&usb_serial_driver);
1270         if (result < 0) {
1271                 pr_err("%s - usb_register failed\n", __func__);
1272                 goto exit_tty;
1273         }
1274
1275         /* register the generic driver, if we should */
1276         result = usb_serial_generic_register();
1277         if (result < 0) {
1278                 pr_err("%s - registering generic driver failed\n", __func__);
1279                 goto exit_generic;
1280         }
1281
1282         return result;
1283
1284 exit_generic:
1285         usb_deregister(&usb_serial_driver);
1286
1287 exit_tty:
1288         tty_unregister_driver(usb_serial_tty_driver);
1289
1290 exit_reg_driver:
1291         bus_unregister(&usb_serial_bus_type);
1292
1293 exit_bus:
1294         pr_err("%s - returning with error %d\n", __func__, result);
1295         put_tty_driver(usb_serial_tty_driver);
1296         return result;
1297 }
1298
1299
1300 static void __exit usb_serial_exit(void)
1301 {
1302         usb_serial_console_exit();
1303
1304         usb_serial_generic_deregister();
1305
1306         usb_deregister(&usb_serial_driver);
1307         tty_unregister_driver(usb_serial_tty_driver);
1308         put_tty_driver(usb_serial_tty_driver);
1309         bus_unregister(&usb_serial_bus_type);
1310 }
1311
1312
1313 module_init(usb_serial_init);
1314 module_exit(usb_serial_exit);
1315
1316 #define set_to_generic_if_null(type, function)                          \
1317         do {                                                            \
1318                 if (!type->function) {                                  \
1319                         type->function = usb_serial_generic_##function; \
1320                         pr_debug("Had to override the " #function       \
1321                                 " usb serial operation with the generic one.");\
1322                         }                                               \
1323         } while (0)
1324
1325 static void fixup_generic(struct usb_serial_driver *device)
1326 {
1327         set_to_generic_if_null(device, open);
1328         set_to_generic_if_null(device, write);
1329         set_to_generic_if_null(device, close);
1330         set_to_generic_if_null(device, write_room);
1331         set_to_generic_if_null(device, chars_in_buffer);
1332         set_to_generic_if_null(device, read_bulk_callback);
1333         set_to_generic_if_null(device, write_bulk_callback);
1334         set_to_generic_if_null(device, disconnect);
1335         set_to_generic_if_null(device, release);
1336         set_to_generic_if_null(device, process_read_urb);
1337         set_to_generic_if_null(device, prepare_write_buffer);
1338 }
1339
1340 static int usb_serial_register(struct usb_serial_driver *driver)
1341 {
1342         int retval;
1343
1344         if (usb_disabled())
1345                 return -ENODEV;
1346
1347         fixup_generic(driver);
1348
1349         if (!driver->description)
1350                 driver->description = driver->driver.name;
1351         if (!driver->usb_driver) {
1352                 WARN(1, "Serial driver %s has no usb_driver\n",
1353                                 driver->description);
1354                 return -EINVAL;
1355         }
1356
1357         /* Add this device to our list of devices */
1358         mutex_lock(&table_lock);
1359         list_add(&driver->driver_list, &usb_serial_driver_list);
1360
1361         retval = usb_serial_bus_register(driver);
1362         if (retval) {
1363                 pr_err("problem %d when registering driver %s\n", retval, driver->description);
1364                 list_del(&driver->driver_list);
1365         } else
1366                 pr_info("USB Serial support registered for %s\n", driver->description);
1367
1368         mutex_unlock(&table_lock);
1369         return retval;
1370 }
1371
1372 static void usb_serial_deregister(struct usb_serial_driver *device)
1373 {
1374         pr_info("USB Serial deregistering driver %s\n", device->description);
1375         mutex_lock(&table_lock);
1376         list_del(&device->driver_list);
1377         usb_serial_bus_deregister(device);
1378         mutex_unlock(&table_lock);
1379 }
1380
1381 /**
1382  * usb_serial_register_drivers - register drivers for a usb-serial module
1383  * @serial_drivers: NULL-terminated array of pointers to drivers to be registered
1384  * @name: name of the usb_driver for this set of @serial_drivers
1385  * @id_table: list of all devices this @serial_drivers set binds to
1386  *
1387  * Registers all the drivers in the @serial_drivers array, and dynamically
1388  * creates a struct usb_driver with the name @name and id_table of @id_table.
1389  */
1390 int usb_serial_register_drivers(struct usb_serial_driver *const serial_drivers[],
1391                                 const char *name,
1392                                 const struct usb_device_id *id_table)
1393 {
1394         int rc;
1395         struct usb_driver *udriver;
1396         struct usb_serial_driver * const *sd;
1397
1398         /*
1399          * udriver must be registered before any of the serial drivers,
1400          * because the store_new_id() routine for the serial drivers (in
1401          * bus.c) probes udriver.
1402          *
1403          * Performance hack: We don't want udriver to be probed until
1404          * the serial drivers are registered, because the probe would
1405          * simply fail for lack of a matching serial driver.
1406          * So we leave udriver's id_table set to NULL until we are all set.
1407          *
1408          * Suspend/resume support is implemented in the usb-serial core,
1409          * so fill in the PM-related fields in udriver.
1410          */
1411         udriver = kzalloc(sizeof(*udriver), GFP_KERNEL);
1412         if (!udriver)
1413                 return -ENOMEM;
1414
1415         udriver->name = name;
1416         udriver->no_dynamic_id = 1;
1417         udriver->supports_autosuspend = 1;
1418         udriver->suspend = usb_serial_suspend;
1419         udriver->resume = usb_serial_resume;
1420         udriver->probe = usb_serial_probe;
1421         udriver->disconnect = usb_serial_disconnect;
1422
1423         /* we only set the reset_resume field if the serial_driver has one */
1424         for (sd = serial_drivers; *sd; ++sd) {
1425                 if ((*sd)->reset_resume) {
1426                         udriver->reset_resume = usb_serial_reset_resume;
1427                         break;
1428                 }
1429         }
1430
1431         rc = usb_register(udriver);
1432         if (rc)
1433                 return rc;
1434
1435         for (sd = serial_drivers; *sd; ++sd) {
1436                 (*sd)->usb_driver = udriver;
1437                 rc = usb_serial_register(*sd);
1438                 if (rc)
1439                         goto failed;
1440         }
1441
1442         /* Now set udriver's id_table and look for matches */
1443         udriver->id_table = id_table;
1444         rc = driver_attach(&udriver->drvwrap.driver);
1445         return 0;
1446
1447  failed:
1448         while (sd-- > serial_drivers)
1449                 usb_serial_deregister(*sd);
1450         usb_deregister(udriver);
1451         return rc;
1452 }
1453 EXPORT_SYMBOL_GPL(usb_serial_register_drivers);
1454
1455 /**
1456  * usb_serial_deregister_drivers - deregister drivers for a usb-serial module
1457  * @serial_drivers: NULL-terminated array of pointers to drivers to be deregistered
1458  *
1459  * Deregisters all the drivers in the @serial_drivers array and deregisters and
1460  * frees the struct usb_driver that was created by the call to
1461  * usb_serial_register_drivers().
1462  */
1463 void usb_serial_deregister_drivers(struct usb_serial_driver *const serial_drivers[])
1464 {
1465         struct usb_driver *udriver = (*serial_drivers)->usb_driver;
1466
1467         for (; *serial_drivers; ++serial_drivers)
1468                 usb_serial_deregister(*serial_drivers);
1469         usb_deregister(udriver);
1470         kfree(udriver);
1471 }
1472 EXPORT_SYMBOL_GPL(usb_serial_deregister_drivers);
1473
1474 /* Module information */
1475 MODULE_AUTHOR(DRIVER_AUTHOR);
1476 MODULE_DESCRIPTION(DRIVER_DESC);
1477 MODULE_LICENSE("GPL");