drivers/usb/class/cdc-wdm.c

   1 /*
   2  * cdc-wdm.c
   3  *
   4  * This driver supports USB CDC WCM Device Management.
   5  *
   6  * Copyright (c) 2007-2009 Oliver Neukum
   7  *
   8  * Some code taken from cdc-acm.c
   9  *
  10  * Released under the GPLv2.
  11  *
  12  * Many thanks to Carl Nordbeck
  13  */
  14 #include <linux/kernel.h>
  15 #include <linux/errno.h>
  16 #include <linux/slab.h>
  17 #include <linux/module.h>
  18 #include <linux/mutex.h>
  19 #include <linux/uaccess.h>
  20 #include <linux/bitops.h>
  21 #include <linux/poll.h>
  22 #include <linux/usb.h>
  23 #include <linux/usb/cdc.h>
  24 #include <asm/byteorder.h>
  25 #include <asm/unaligned.h>
  26
  27 /*
  28  * Version Information
  29  */
  30 #define DRIVER_VERSION "v0.03"
  31 #define DRIVER_AUTHOR "Oliver Neukum"
  32 #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management"
  33
  34 static const struct usb_device_id wdm_ids[] = {
  35         {
  36                 .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS |
  37                                  USB_DEVICE_ID_MATCH_INT_SUBCLASS,
  38                 .bInterfaceClass = USB_CLASS_COMM,
  39                 .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM
  40         },
  41         { }
  42 };
  43
  44 MODULE_DEVICE_TABLE (usb, wdm_ids);
  45
  46 #define WDM_MINOR_BASE  176
  47
  48
  49 #define WDM_IN_USE              1
  50 #define WDM_DISCONNECTING       2
  51 #define WDM_RESULT              3
  52 #define WDM_READ                4
  53 #define WDM_INT_STALL           5
  54 #define WDM_POLL_RUNNING        6
  55
  56
  57 #define WDM_MAX                 16
  58
  59
  60 static DEFINE_MUTEX(wdm_mutex);
  61
  62 /* --- method tables --- */
  63
  64 struct wdm_device {
  65         u8                      *inbuf; /* buffer for response */
  66         u8                      *outbuf; /* buffer for command */
  67         u8                      *sbuf; /* buffer for status */
  68         u8                      *ubuf; /* buffer for copy to user space */
  69
  70         struct urb              *command;
  71         struct urb              *response;
  72         struct urb              *validity;
  73         struct usb_interface    *intf;
  74         struct usb_ctrlrequest  *orq;
  75         struct usb_ctrlrequest  *irq;
  76         spinlock_t              iuspin;
  77
  78         unsigned long           flags;
  79         u16                     bufsize;
  80         u16                     wMaxCommand;
  81         u16                     wMaxPacketSize;
  82         u16                     bMaxPacketSize0;
  83         __le16                  inum;
  84         int                     reslength;
  85         int                     length;
  86         int                     read;
  87         int                     count;
  88         dma_addr_t              shandle;
  89         dma_addr_t              ihandle;
  90         struct mutex            wlock;
  91         struct mutex            rlock;
  92         struct mutex            plock;
  93         wait_queue_head_t       wait;
  94         struct work_struct      rxwork;
  95         int                     werr;
  96         int                     rerr;
  97 };
  98
  99 static struct usb_driver wdm_driver;
 100
 101 /* --- callbacks --- */
 102 static void wdm_out_callback(struct urb *urb)
 103 {
 104         struct wdm_device *desc;
 105         desc = urb->context;
 106         spin_lock(&desc->iuspin);
 107         desc->werr = urb->status;
 108         spin_unlock(&desc->iuspin);
 109         clear_bit(WDM_IN_USE, &desc->flags);
 110         kfree(desc->outbuf);
 111         wake_up(&desc->wait);
 112 }
 113
 114 static void wdm_in_callback(struct urb *urb)
 115 {
 116         struct wdm_device *desc = urb->context;
 117         int status = urb->status;
 118
 119         spin_lock(&desc->iuspin);
 120
 121         if (status) {
 122                 switch (status) {
 123                 case -ENOENT:
 124                         dev_dbg(&desc->intf->dev,
 125                                 "nonzero urb status received: -ENOENT");
 126                         break;
 127                 case -ECONNRESET:
 128                         dev_dbg(&desc->intf->dev,
 129                                 "nonzero urb status received: -ECONNRESET");
 130                         break;
 131                 case -ESHUTDOWN:
 132                         dev_dbg(&desc->intf->dev,
 133                                 "nonzero urb status received: -ESHUTDOWN");
 134                         break;
 135                 case -EPIPE:
 136                         dev_err(&desc->intf->dev,
 137                                 "nonzero urb status received: -EPIPE\n");
 138                         break;
 139                 default:
 140                         dev_err(&desc->intf->dev,
 141                                 "Unexpected error %d\n", status);
 142                         break;
 143                 }
 144         }
 145
 146         desc->rerr = status;
 147         desc->reslength = urb->actual_length;
 148         memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
 149         desc->length += desc->reslength;
 150         wake_up(&desc->wait);
 151
 152         set_bit(WDM_READ, &desc->flags);
 153         spin_unlock(&desc->iuspin);
 154 }
 155
 156 static void wdm_int_callback(struct urb *urb)
 157 {
 158         int rv = 0;
 159         int status = urb->status;
 160         struct wdm_device *desc;
 161         struct usb_ctrlrequest *req;
 162         struct usb_cdc_notification *dr;
 163
 164         desc = urb->context;
 165         req = desc->irq;
 166         dr = (struct usb_cdc_notification *)desc->sbuf;
 167
 168         if (status) {
 169                 switch (status) {
 170                 case -ESHUTDOWN:
 171                 case -ENOENT:
 172                 case -ECONNRESET:
 173                         return; /* unplug */
 174                 case -EPIPE:
 175                         set_bit(WDM_INT_STALL, &desc->flags);
 176                         dev_err(&desc->intf->dev, "Stall on int endpoint\n");
 177                         goto sw; /* halt is cleared in work */
 178                 default:
 179                         dev_err(&desc->intf->dev,
 180                                 "nonzero urb status received: %d\n", status);
 181                         break;
 182                 }
 183         }
 184
 185         if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
 186                 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
 187                         urb->actual_length);
 188                 goto exit;
 189         }
 190
 191         switch (dr->bNotificationType) {
 192         case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
 193                 dev_dbg(&desc->intf->dev,
 194                         "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
 195                         dr->wIndex, dr->wLength);
 196                 break;
 197
 198         case USB_CDC_NOTIFY_NETWORK_CONNECTION:
 199
 200                 dev_dbg(&desc->intf->dev,
 201                         "NOTIFY_NETWORK_CONNECTION %s network",
 202                         dr->wValue ? "connected to" : "disconnected from");
 203                 goto exit;
 204         default:
 205                 clear_bit(WDM_POLL_RUNNING, &desc->flags);
 206                 dev_err(&desc->intf->dev,
 207                         "unknown notification %d received: index %d len %d\n",
 208                         dr->bNotificationType, dr->wIndex, dr->wLength);
 209                 goto exit;
 210         }
 211
 212         req->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
 213         req->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
 214         req->wValue = 0;
 215         req->wIndex = desc->inum;
 216         req->wLength = cpu_to_le16(desc->wMaxCommand);
 217
 218         usb_fill_control_urb(
 219                 desc->response,
 220                 interface_to_usbdev(desc->intf),
 221                 /* using common endpoint 0 */
 222                 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
 223                 (unsigned char *)req,
 224                 desc->inbuf,
 225                 desc->wMaxCommand,
 226                 wdm_in_callback,
 227                 desc
 228         );
 229         desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 230         spin_lock(&desc->iuspin);
 231         clear_bit(WDM_READ, &desc->flags);
 232         if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
 233                 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
 234                 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
 235                         __func__, rv);
 236         }
 237         spin_unlock(&desc->iuspin);
 238         if (rv < 0) {
 239                 if (rv == -EPERM)
 240                         return;
 241                 if (rv == -ENOMEM) {
 242 sw:
 243                         rv = schedule_work(&desc->rxwork);
 244                         if (rv)
 245                                 dev_err(&desc->intf->dev,
 246                                         "Cannot schedule work\n");
 247                 }
 248         }
 249 exit:
 250         rv = usb_submit_urb(urb, GFP_ATOMIC);
 251         if (rv)
 252                 dev_err(&desc->intf->dev,
 253                         "%s - usb_submit_urb failed with result %d\n",
 254                         __func__, rv);
 255
 256 }
 257
 258 static void kill_urbs(struct wdm_device *desc)
 259 {
 260         /* the order here is essential */
 261         usb_kill_urb(desc->command);
 262         usb_kill_urb(desc->validity);
 263         usb_kill_urb(desc->response);
 264 }
 265
 266 static void free_urbs(struct wdm_device *desc)
 267 {
 268         usb_free_urb(desc->validity);
 269         usb_free_urb(desc->response);
 270         usb_free_urb(desc->command);
 271 }
 272
 273 static void cleanup(struct wdm_device *desc)
 274 {
 275         usb_buffer_free(interface_to_usbdev(desc->intf),
 276                         desc->wMaxPacketSize,
 277                         desc->sbuf,
 278                         desc->validity->transfer_dma);
 279         usb_buffer_free(interface_to_usbdev(desc->intf),
 280                         desc->wMaxCommand,
 281                         desc->inbuf,
 282                         desc->response->transfer_dma);
 283         kfree(desc->orq);
 284         kfree(desc->irq);
 285         kfree(desc->ubuf);
 286         free_urbs(desc);
 287         kfree(desc);
 288 }
 289
 290 static ssize_t wdm_write
 291 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 292 {
 293         u8 *buf;
 294         int rv = -EMSGSIZE, r, we;
 295         struct wdm_device *desc = file->private_data;
 296         struct usb_ctrlrequest *req;
 297
 298         if (count > desc->wMaxCommand)
 299                 count = desc->wMaxCommand;
 300
 301         spin_lock_irq(&desc->iuspin);
 302         we = desc->werr;
 303         desc->werr = 0;
 304         spin_unlock_irq(&desc->iuspin);
 305         if (we < 0)
 306                 return -EIO;
 307
 308         r = mutex_lock_interruptible(&desc->wlock); /* concurrent writes */
 309         rv = -ERESTARTSYS;
 310         if (r)
 311                 goto outnl;
 312
 313         r = usb_autopm_get_interface(desc->intf);
 314         if (r < 0)
 315                 goto outnp;
 316
 317         if (!file->f_flags && O_NONBLOCK)
 318                 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
 319                                                                 &desc->flags));
 320         else
 321                 if (test_bit(WDM_IN_USE, &desc->flags))
 322                         r = -EAGAIN;
 323         if (r < 0)
 324                 goto out;
 325
 326         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 327                 rv = -ENODEV;
 328                 goto out;
 329         }
 330
 331         desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
 332         if (!buf) {
 333                 rv = -ENOMEM;
 334                 goto out;
 335         }
 336
 337         r = copy_from_user(buf, buffer, count);
 338         if (r > 0) {
 339                 kfree(buf);
 340                 rv = -EFAULT;
 341                 goto out;
 342         }
 343
 344         req = desc->orq;
 345         usb_fill_control_urb(
 346                 desc->command,
 347                 interface_to_usbdev(desc->intf),
 348                 /* using common endpoint 0 */
 349                 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
 350                 (unsigned char *)req,
 351                 buf,
 352                 count,
 353                 wdm_out_callback,
 354                 desc
 355         );
 356
 357         req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
 358                              USB_RECIP_INTERFACE);
 359         req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
 360         req->wValue = 0;
 361         req->wIndex = desc->inum;
 362         req->wLength = cpu_to_le16(count);
 363         set_bit(WDM_IN_USE, &desc->flags);
 364
 365         rv = usb_submit_urb(desc->command, GFP_KERNEL);
 366         if (rv < 0) {
 367                 kfree(buf);
 368                 clear_bit(WDM_IN_USE, &desc->flags);
 369                 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
 370         } else {
 371                 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
 372                         req->wIndex);
 373         }
 374 out:
 375         usb_autopm_put_interface(desc->intf);
 376 outnp:
 377         mutex_unlock(&desc->wlock);
 378 outnl:
 379         return rv < 0 ? rv : count;
 380 }
 381
 382 static ssize_t wdm_read
 383 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 384 {
 385         int rv, cntr = 0;
 386         int i = 0;
 387         struct wdm_device *desc = file->private_data;
 388
 389
 390         rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
 391         if (rv < 0)
 392                 return -ERESTARTSYS;
 393
 394         if (desc->length == 0) {
 395                 desc->read = 0;
 396 retry:
 397                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 398                         rv = -ENODEV;
 399                         goto err;
 400                 }
 401                 i++;
 402                 if (file->f_flags & O_NONBLOCK) {
 403                         if (!test_bit(WDM_READ, &desc->flags)) {
 404                                 rv = cntr ? cntr : -EAGAIN;
 405                                 goto err;
 406                         }
 407                         rv = 0;
 408                 } else {
 409                         rv = wait_event_interruptible(desc->wait,
 410                                 test_bit(WDM_READ, &desc->flags));
 411                 }
 412
 413                 /* may have happened while we slept */
 414                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 415                         rv = -ENODEV;
 416                         goto err;
 417                 }
 418                 usb_mark_last_busy(interface_to_usbdev(desc->intf));
 419                 if (rv < 0) {
 420                         rv = -ERESTARTSYS;
 421                         goto err;
 422                 }
 423
 424                 spin_lock_irq(&desc->iuspin);
 425
 426                 if (desc->rerr) { /* read completed, error happened */
 427                         int t = desc->rerr;
 428                         desc->rerr = 0;
 429                         spin_unlock_irq(&desc->iuspin);
 430                         dev_err(&desc->intf->dev,
 431                                 "reading had resulted in %d\n", t);
 432                         rv = -EIO;
 433                         goto err;
 434                 }
 435                 /*
 436                  * recheck whether we've lost the race
 437                  * against the completion handler
 438                  */
 439                 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
 440                         spin_unlock_irq(&desc->iuspin);
 441                         goto retry;
 442                 }
 443                 if (!desc->reslength) { /* zero length read */
 444                         spin_unlock_irq(&desc->iuspin);
 445                         goto retry;
 446                 }
 447                 clear_bit(WDM_READ, &desc->flags);
 448                 spin_unlock_irq(&desc->iuspin);
 449         }
 450
 451         cntr = count > desc->length ? desc->length : count;
 452         rv = copy_to_user(buffer, desc->ubuf, cntr);
 453         if (rv > 0) {
 454                 rv = -EFAULT;
 455                 goto err;
 456         }
 457
 458         for (i = 0; i < desc->length - cntr; i++)
 459                 desc->ubuf[i] = desc->ubuf[i + cntr];
 460
 461         desc->length -= cntr;
 462         /* in case we had outstanding data */
 463         if (!desc->length)
 464                 clear_bit(WDM_READ, &desc->flags);
 465         rv = cntr;
 466
 467 err:
 468         mutex_unlock(&desc->rlock);
 469         if (rv < 0 && rv != -EAGAIN)
 470                 dev_err(&desc->intf->dev, "wdm_read: exit error\n");
 471         return rv;
 472 }
 473
 474 static int wdm_flush(struct file *file, fl_owner_t id)
 475 {
 476         struct wdm_device *desc = file->private_data;
 477
 478         wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
 479         if (desc->werr < 0)
 480                 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
 481                         desc->werr);
 482
 483         return desc->werr;
 484 }
 485
 486 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
 487 {
 488         struct wdm_device *desc = file->private_data;
 489         unsigned long flags;
 490         unsigned int mask = 0;
 491
 492         spin_lock_irqsave(&desc->iuspin, flags);
 493         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 494                 mask = POLLERR;
 495                 spin_unlock_irqrestore(&desc->iuspin, flags);
 496                 goto desc_out;
 497         }
 498         if (test_bit(WDM_READ, &desc->flags))
 499                 mask = POLLIN | POLLRDNORM;
 500         if (desc->rerr || desc->werr)
 501                 mask |= POLLERR;
 502         if (!test_bit(WDM_IN_USE, &desc->flags))
 503                 mask |= POLLOUT | POLLWRNORM;
 504         spin_unlock_irqrestore(&desc->iuspin, flags);
 505
 506         poll_wait(file, &desc->wait, wait);
 507
 508 desc_out:
 509         return mask;
 510 }
 511
 512 static int wdm_open(struct inode *inode, struct file *file)
 513 {
 514         int minor = iminor(inode);
 515         int rv = -ENODEV;
 516         struct usb_interface *intf;
 517         struct wdm_device *desc;
 518
 519         mutex_lock(&wdm_mutex);
 520         intf = usb_find_interface(&wdm_driver, minor);
 521         if (!intf)
 522                 goto out;
 523
 524         desc = usb_get_intfdata(intf);
 525         if (test_bit(WDM_DISCONNECTING, &desc->flags))
 526                 goto out;
 527         file->private_data = desc;
 528
 529         rv = usb_autopm_get_interface(desc->intf);
 530         if (rv < 0) {
 531                 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
 532                 goto out;
 533         }
 534         intf->needs_remote_wakeup = 1;
 535
 536         mutex_lock(&desc->plock);
 537         if (!desc->count++) {
 538                 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
 539                 if (rv < 0) {
 540                         desc->count--;
 541                         dev_err(&desc->intf->dev,
 542                                 "Error submitting int urb - %d\n", rv);
 543                 }
 544         } else {
 545                 rv = 0;
 546         }
 547         mutex_unlock(&desc->plock);
 548         usb_autopm_put_interface(desc->intf);
 549 out:
 550         mutex_unlock(&wdm_mutex);
 551         return rv;
 552 }
 553
 554 static int wdm_release(struct inode *inode, struct file *file)
 555 {
 556         struct wdm_device *desc = file->private_data;
 557
 558         mutex_lock(&wdm_mutex);
 559         mutex_lock(&desc->plock);
 560         desc->count--;
 561         mutex_unlock(&desc->plock);
 562
 563         if (!desc->count) {
 564                 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
 565                 kill_urbs(desc);
 566                 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 567                         desc->intf->needs_remote_wakeup = 0;
 568         }
 569         mutex_unlock(&wdm_mutex);
 570         return 0;
 571 }
 572
 573 static const struct file_operations wdm_fops = {
 574         .owner =        THIS_MODULE,
 575         .read =         wdm_read,
 576         .write =        wdm_write,
 577         .open =         wdm_open,
 578         .flush =        wdm_flush,
 579         .release =      wdm_release,
 580         .poll =         wdm_poll
 581 };
 582
 583 static struct usb_class_driver wdm_class = {
 584         .name =         "cdc-wdm%d",
 585         .fops =         &wdm_fops,
 586         .minor_base =   WDM_MINOR_BASE,
 587 };
 588
 589 /* --- error handling --- */
 590 static void wdm_rxwork(struct work_struct *work)
 591 {
 592         struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
 593         unsigned long flags;
 594         int rv;
 595
 596         spin_lock_irqsave(&desc->iuspin, flags);
 597         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 598                 spin_unlock_irqrestore(&desc->iuspin, flags);
 599         } else {
 600                 spin_unlock_irqrestore(&desc->iuspin, flags);
 601                 rv = usb_submit_urb(desc->response, GFP_KERNEL);
 602                 if (rv < 0 && rv != -EPERM) {
 603                         spin_lock_irqsave(&desc->iuspin, flags);
 604                         if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 605                                 schedule_work(&desc->rxwork);
 606                         spin_unlock_irqrestore(&desc->iuspin, flags);
 607                 }
 608         }
 609 }
 610
 611 /* --- hotplug --- */
 612
 613 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
 614 {
 615         int rv = -EINVAL;
 616         struct usb_device *udev = interface_to_usbdev(intf);
 617         struct wdm_device *desc;
 618         struct usb_host_interface *iface;
 619         struct usb_endpoint_descriptor *ep;
 620         struct usb_cdc_dmm_desc *dmhd;
 621         u8 *buffer = intf->altsetting->extra;
 622         int buflen = intf->altsetting->extralen;
 623         u16 maxcom = 0;
 624
 625         if (!buffer)
 626                 goto out;
 627
 628         while (buflen > 2) {
 629                 if (buffer [1] != USB_DT_CS_INTERFACE) {
 630                         dev_err(&intf->dev, "skipping garbage\n");
 631                         goto next_desc;
 632                 }
 633
 634                 switch (buffer [2]) {
 635                 case USB_CDC_HEADER_TYPE:
 636                         break;
 637                 case USB_CDC_DMM_TYPE:
 638                         dmhd = (struct usb_cdc_dmm_desc *)buffer;
 639                         maxcom = le16_to_cpu(dmhd->wMaxCommand);
 640                         dev_dbg(&intf->dev,
 641                                 "Finding maximum buffer length: %d", maxcom);
 642                         break;
 643                 default:
 644                         dev_err(&intf->dev,
 645                                 "Ignoring extra header, type %d, length %d\n",
 646                                 buffer[2], buffer[0]);
 647                         break;
 648                 }
 649 next_desc:
 650                 buflen -= buffer[0];
 651                 buffer += buffer[0];
 652         }
 653
 654         rv = -ENOMEM;
 655         desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
 656         if (!desc)
 657                 goto out;
 658         mutex_init(&desc->wlock);
 659         mutex_init(&desc->rlock);
 660         mutex_init(&desc->plock);
 661         spin_lock_init(&desc->iuspin);
 662         init_waitqueue_head(&desc->wait);
 663         desc->wMaxCommand = maxcom;
 664         /* this will be expanded and needed in hardware endianness */
 665         desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
 666         desc->intf = intf;
 667         INIT_WORK(&desc->rxwork, wdm_rxwork);
 668
 669         rv = -EINVAL;
 670         iface = intf->cur_altsetting;
 671         if (iface->desc.bNumEndpoints != 1)
 672                 goto err;
 673         ep = &iface->endpoint[0].desc;
 674         if (!ep || !usb_endpoint_is_int_in(ep))
 675                 goto err;
 676
 677         desc->wMaxPacketSize = le16_to_cpu(ep->wMaxPacketSize);
 678         desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0;
 679
 680         desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 681         if (!desc->orq)
 682                 goto err;
 683         desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 684         if (!desc->irq)
 685                 goto err;
 686
 687         desc->validity = usb_alloc_urb(0, GFP_KERNEL);
 688         if (!desc->validity)
 689                 goto err;
 690
 691         desc->response = usb_alloc_urb(0, GFP_KERNEL);
 692         if (!desc->response)
 693                 goto err;
 694
 695         desc->command = usb_alloc_urb(0, GFP_KERNEL);
 696         if (!desc->command)
 697                 goto err;
 698
 699         desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
 700         if (!desc->ubuf)
 701                 goto err;
 702
 703         desc->sbuf = usb_buffer_alloc(interface_to_usbdev(intf),
 704                                         desc->wMaxPacketSize,
 705                                         GFP_KERNEL,
 706                                         &desc->validity->transfer_dma);
 707         if (!desc->sbuf)
 708                 goto err;
 709
 710         desc->inbuf = usb_buffer_alloc(interface_to_usbdev(intf),
 711                                         desc->bMaxPacketSize0,
 712                                         GFP_KERNEL,
 713                                         &desc->response->transfer_dma);
 714         if (!desc->inbuf)
 715                 goto err2;
 716
 717         usb_fill_int_urb(
 718                 desc->validity,
 719                 interface_to_usbdev(intf),
 720                 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
 721                 desc->sbuf,
 722                 desc->wMaxPacketSize,
 723                 wdm_int_callback,
 724                 desc,
 725                 ep->bInterval
 726         );
 727         desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 728
 729         usb_set_intfdata(intf, desc);
 730         rv = usb_register_dev(intf, &wdm_class);
 731         if (rv < 0)
 732                 goto err3;
 733         else
 734                 dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
 735                         intf->minor - WDM_MINOR_BASE);
 736 out:
 737         return rv;
 738 err3:
 739         usb_set_intfdata(intf, NULL);
 740         usb_buffer_free(interface_to_usbdev(desc->intf),
 741                         desc->bMaxPacketSize0,
 742                         desc->inbuf,
 743                         desc->response->transfer_dma);
 744 err2:
 745         usb_buffer_free(interface_to_usbdev(desc->intf),
 746                         desc->wMaxPacketSize,
 747                         desc->sbuf,
 748                         desc->validity->transfer_dma);
 749 err:
 750         free_urbs(desc);
 751         kfree(desc->ubuf);
 752         kfree(desc->orq);
 753         kfree(desc->irq);
 754         kfree(desc);
 755         return rv;
 756 }
 757
 758 static void wdm_disconnect(struct usb_interface *intf)
 759 {
 760         struct wdm_device *desc;
 761         unsigned long flags;
 762
 763         usb_deregister_dev(intf, &wdm_class);
 764         mutex_lock(&wdm_mutex);
 765         desc = usb_get_intfdata(intf);
 766
 767         /* the spinlock makes sure no new urbs are generated in the callbacks */
 768         spin_lock_irqsave(&desc->iuspin, flags);
 769         set_bit(WDM_DISCONNECTING, &desc->flags);
 770         set_bit(WDM_READ, &desc->flags);
 771         /* to terminate pending flushes */
 772         clear_bit(WDM_IN_USE, &desc->flags);
 773         spin_unlock_irqrestore(&desc->iuspin, flags);
 774         cancel_work_sync(&desc->rxwork);
 775         kill_urbs(desc);
 776         wake_up_all(&desc->wait);
 777         if (!desc->count)
 778                 cleanup(desc);
 779         mutex_unlock(&wdm_mutex);
 780 }
 781
 782 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
 783 {
 784         struct wdm_device *desc = usb_get_intfdata(intf);
 785         int rv = 0;
 786
 787         dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
 788
 789         mutex_lock(&desc->plock);
 790 #ifdef CONFIG_PM
 791         if ((message.event & PM_EVENT_AUTO) &&
 792                         test_bit(WDM_IN_USE, &desc->flags)) {
 793                 rv = -EBUSY;
 794         } else {
 795 #endif
 796                 cancel_work_sync(&desc->rxwork);
 797                 kill_urbs(desc);
 798 #ifdef CONFIG_PM
 799         }
 800 #endif
 801         mutex_unlock(&desc->plock);
 802
 803         return rv;
 804 }
 805
 806 static int recover_from_urb_loss(struct wdm_device *desc)
 807 {
 808         int rv = 0;
 809
 810         if (desc->count) {
 811                 rv = usb_submit_urb(desc->validity, GFP_NOIO);
 812                 if (rv < 0)
 813                         dev_err(&desc->intf->dev,
 814                                 "Error resume submitting int urb - %d\n", rv);
 815         }
 816         return rv;
 817 }
 818 static int wdm_resume(struct usb_interface *intf)
 819 {
 820         struct wdm_device *desc = usb_get_intfdata(intf);
 821         int rv;
 822
 823         dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
 824         mutex_lock(&desc->plock);
 825         rv = recover_from_urb_loss(desc);
 826         mutex_unlock(&desc->plock);
 827         return rv;
 828 }
 829
 830 static int wdm_pre_reset(struct usb_interface *intf)
 831 {
 832         struct wdm_device *desc = usb_get_intfdata(intf);
 833
 834         mutex_lock(&desc->plock);
 835         return 0;
 836 }
 837
 838 static int wdm_post_reset(struct usb_interface *intf)
 839 {
 840         struct wdm_device *desc = usb_get_intfdata(intf);
 841         int rv;
 842
 843         rv = recover_from_urb_loss(desc);
 844         mutex_unlock(&desc->plock);
 845         return 0;
 846 }
 847
 848 static struct usb_driver wdm_driver = {
 849         .name =         "cdc_wdm",
 850         .probe =        wdm_probe,
 851         .disconnect =   wdm_disconnect,
 852         .suspend =      wdm_suspend,
 853         .resume =       wdm_resume,
 854         .reset_resume = wdm_resume,
 855         .pre_reset =    wdm_pre_reset,
 856         .post_reset =   wdm_post_reset,
 857         .id_table =     wdm_ids,
 858         .supports_autosuspend = 1,
 859 };
 860
 861 /* --- low level module stuff --- */
 862
 863 static int __init wdm_init(void)
 864 {
 865         int rv;
 866
 867         rv = usb_register(&wdm_driver);
 868
 869         return rv;
 870 }
 871
 872 static void __exit wdm_exit(void)
 873 {
 874         usb_deregister(&wdm_driver);
 875 }
 876
 877 module_init(wdm_init);
 878 module_exit(wdm_exit);
 879
 880 MODULE_AUTHOR(DRIVER_AUTHOR);
 881 MODULE_DESCRIPTION(DRIVER_DESC);
 882 MODULE_LICENSE("GPL");