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 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         r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
 317                                                            &desc->flags));
 318         if (r < 0)
 319                 goto out;
 320
 321         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 322                 rv = -ENODEV;
 323                 goto out;
 324         }
 325
 326         desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
 327         if (!buf) {
 328                 rv = -ENOMEM;
 329                 goto out;
 330         }
 331
 332         r = copy_from_user(buf, buffer, count);
 333         if (r > 0) {
 334                 kfree(buf);
 335                 rv = -EFAULT;
 336                 goto out;
 337         }
 338
 339         req = desc->orq;
 340         usb_fill_control_urb(
 341                 desc->command,
 342                 interface_to_usbdev(desc->intf),
 343                 /* using common endpoint 0 */
 344                 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
 345                 (unsigned char *)req,
 346                 buf,
 347                 count,
 348                 wdm_out_callback,
 349                 desc
 350         );
 351
 352         req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
 353                              USB_RECIP_INTERFACE);
 354         req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
 355         req->wValue = 0;
 356         req->wIndex = desc->inum;
 357         req->wLength = cpu_to_le16(count);
 358         set_bit(WDM_IN_USE, &desc->flags);
 359
 360         rv = usb_submit_urb(desc->command, GFP_KERNEL);
 361         if (rv < 0) {
 362                 kfree(buf);
 363                 clear_bit(WDM_IN_USE, &desc->flags);
 364                 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
 365         } else {
 366                 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
 367                         req->wIndex);
 368         }
 369 out:
 370         usb_autopm_put_interface(desc->intf);
 371 outnp:
 372         mutex_unlock(&desc->wlock);
 373 outnl:
 374         return rv < 0 ? rv : count;
 375 }
 376
 377 static ssize_t wdm_read
 378 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 379 {
 380         int rv, cntr;
 381         int i = 0;
 382         struct wdm_device *desc = file->private_data;
 383
 384
 385         rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
 386         if (rv < 0)
 387                 return -ERESTARTSYS;
 388
 389         if (desc->length == 0) {
 390                 desc->read = 0;
 391 retry:
 392                 i++;
 393                 rv = wait_event_interruptible(desc->wait,
 394                                               test_bit(WDM_READ, &desc->flags));
 395
 396                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 397                         rv = -ENODEV;
 398                         goto err;
 399                 }
 400                 usb_mark_last_busy(interface_to_usbdev(desc->intf));
 401                 if (rv < 0) {
 402                         rv = -ERESTARTSYS;
 403                         goto err;
 404                 }
 405
 406                 spin_lock_irq(&desc->iuspin);
 407
 408                 if (desc->rerr) { /* read completed, error happened */
 409                         int t = desc->rerr;
 410                         desc->rerr = 0;
 411                         spin_unlock_irq(&desc->iuspin);
 412                         dev_err(&desc->intf->dev,
 413                                 "reading had resulted in %d\n", t);
 414                         rv = -EIO;
 415                         goto err;
 416                 }
 417                 /*
 418                  * recheck whether we've lost the race
 419                  * against the completion handler
 420                  */
 421                 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
 422                         spin_unlock_irq(&desc->iuspin);
 423                         goto retry;
 424                 }
 425                 if (!desc->reslength) { /* zero length read */
 426                         spin_unlock_irq(&desc->iuspin);
 427                         goto retry;
 428                 }
 429                 clear_bit(WDM_READ, &desc->flags);
 430                 spin_unlock_irq(&desc->iuspin);
 431         }
 432
 433         cntr = count > desc->length ? desc->length : count;
 434         rv = copy_to_user(buffer, desc->ubuf, cntr);
 435         if (rv > 0) {
 436                 rv = -EFAULT;
 437                 goto err;
 438         }
 439
 440         for (i = 0; i < desc->length - cntr; i++)
 441                 desc->ubuf[i] = desc->ubuf[i + cntr];
 442
 443         desc->length -= cntr;
 444         /* in case we had outstanding data */
 445         if (!desc->length)
 446                 clear_bit(WDM_READ, &desc->flags);
 447         rv = cntr;
 448
 449 err:
 450         mutex_unlock(&desc->rlock);
 451         if (rv < 0)
 452                 dev_err(&desc->intf->dev, "wdm_read: exit error\n");
 453         return rv;
 454 }
 455
 456 static int wdm_flush(struct file *file, fl_owner_t id)
 457 {
 458         struct wdm_device *desc = file->private_data;
 459
 460         wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
 461         if (desc->werr < 0)
 462                 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
 463                         desc->werr);
 464
 465         return desc->werr;
 466 }
 467
 468 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
 469 {
 470         struct wdm_device *desc = file->private_data;
 471         unsigned long flags;
 472         unsigned int mask = 0;
 473
 474         spin_lock_irqsave(&desc->iuspin, flags);
 475         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 476                 mask = POLLERR;
 477                 spin_unlock_irqrestore(&desc->iuspin, flags);
 478                 goto desc_out;
 479         }
 480         if (test_bit(WDM_READ, &desc->flags))
 481                 mask = POLLIN | POLLRDNORM;
 482         if (desc->rerr || desc->werr)
 483                 mask |= POLLERR;
 484         if (!test_bit(WDM_IN_USE, &desc->flags))
 485                 mask |= POLLOUT | POLLWRNORM;
 486         spin_unlock_irqrestore(&desc->iuspin, flags);
 487
 488         poll_wait(file, &desc->wait, wait);
 489
 490 desc_out:
 491         return mask;
 492 }
 493
 494 static int wdm_open(struct inode *inode, struct file *file)
 495 {
 496         int minor = iminor(inode);
 497         int rv = -ENODEV;
 498         struct usb_interface *intf;
 499         struct wdm_device *desc;
 500
 501         mutex_lock(&wdm_mutex);
 502         intf = usb_find_interface(&wdm_driver, minor);
 503         if (!intf)
 504                 goto out;
 505
 506         desc = usb_get_intfdata(intf);
 507         if (test_bit(WDM_DISCONNECTING, &desc->flags))
 508                 goto out;
 509         file->private_data = desc;
 510
 511         rv = usb_autopm_get_interface(desc->intf);
 512         if (rv < 0) {
 513                 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
 514                 goto out;
 515         }
 516         intf->needs_remote_wakeup = 1;
 517
 518         mutex_lock(&desc->plock);
 519         if (!desc->count++) {
 520                 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
 521                 if (rv < 0) {
 522                         desc->count--;
 523                         dev_err(&desc->intf->dev,
 524                                 "Error submitting int urb - %d\n", rv);
 525                 }
 526         } else {
 527                 rv = 0;
 528         }
 529         mutex_unlock(&desc->plock);
 530         usb_autopm_put_interface(desc->intf);
 531 out:
 532         mutex_unlock(&wdm_mutex);
 533         return rv;
 534 }
 535
 536 static int wdm_release(struct inode *inode, struct file *file)
 537 {
 538         struct wdm_device *desc = file->private_data;
 539
 540         mutex_lock(&wdm_mutex);
 541         mutex_lock(&desc->plock);
 542         desc->count--;
 543         mutex_unlock(&desc->plock);
 544
 545         if (!desc->count) {
 546                 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
 547                 kill_urbs(desc);
 548                 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 549                         desc->intf->needs_remote_wakeup = 0;
 550         }
 551         mutex_unlock(&wdm_mutex);
 552         return 0;
 553 }
 554
 555 static const struct file_operations wdm_fops = {
 556         .owner =        THIS_MODULE,
 557         .read =         wdm_read,
 558         .write =        wdm_write,
 559         .open =         wdm_open,
 560         .flush =        wdm_flush,
 561         .release =      wdm_release,
 562         .poll =         wdm_poll
 563 };
 564
 565 static struct usb_class_driver wdm_class = {
 566         .name =         "cdc-wdm%d",
 567         .fops =         &wdm_fops,
 568         .minor_base =   WDM_MINOR_BASE,
 569 };
 570
 571 /* --- error handling --- */
 572 static void wdm_rxwork(struct work_struct *work)
 573 {
 574         struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
 575         unsigned long flags;
 576         int rv;
 577
 578         spin_lock_irqsave(&desc->iuspin, flags);
 579         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 580                 spin_unlock_irqrestore(&desc->iuspin, flags);
 581         } else {
 582                 spin_unlock_irqrestore(&desc->iuspin, flags);
 583                 rv = usb_submit_urb(desc->response, GFP_KERNEL);
 584                 if (rv < 0 && rv != -EPERM) {
 585                         spin_lock_irqsave(&desc->iuspin, flags);
 586                         if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 587                                 schedule_work(&desc->rxwork);
 588                         spin_unlock_irqrestore(&desc->iuspin, flags);
 589                 }
 590         }
 591 }
 592
 593 /* --- hotplug --- */
 594
 595 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
 596 {
 597         int rv = -EINVAL;
 598         struct usb_device *udev = interface_to_usbdev(intf);
 599         struct wdm_device *desc;
 600         struct usb_host_interface *iface;
 601         struct usb_endpoint_descriptor *ep;
 602         struct usb_cdc_dmm_desc *dmhd;
 603         u8 *buffer = intf->altsetting->extra;
 604         int buflen = intf->altsetting->extralen;
 605         u16 maxcom = 0;
 606
 607         if (!buffer)
 608                 goto out;
 609
 610         while (buflen > 2) {
 611                 if (buffer [1] != USB_DT_CS_INTERFACE) {
 612                         dev_err(&intf->dev, "skipping garbage\n");
 613                         goto next_desc;
 614                 }
 615
 616                 switch (buffer [2]) {
 617                 case USB_CDC_HEADER_TYPE:
 618                         break;
 619                 case USB_CDC_DMM_TYPE:
 620                         dmhd = (struct usb_cdc_dmm_desc *)buffer;
 621                         maxcom = le16_to_cpu(dmhd->wMaxCommand);
 622                         dev_dbg(&intf->dev,
 623                                 "Finding maximum buffer length: %d", maxcom);
 624                         break;
 625                 default:
 626                         dev_err(&intf->dev,
 627                                 "Ignoring extra header, type %d, length %d\n",
 628                                 buffer[2], buffer[0]);
 629                         break;
 630                 }
 631 next_desc:
 632                 buflen -= buffer[0];
 633                 buffer += buffer[0];
 634         }
 635
 636         rv = -ENOMEM;
 637         desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
 638         if (!desc)
 639                 goto out;
 640         mutex_init(&desc->wlock);
 641         mutex_init(&desc->rlock);
 642         mutex_init(&desc->plock);
 643         spin_lock_init(&desc->iuspin);
 644         init_waitqueue_head(&desc->wait);
 645         desc->wMaxCommand = maxcom;
 646         /* this will be expanded and needed in hardware endianness */
 647         desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
 648         desc->intf = intf;
 649         INIT_WORK(&desc->rxwork, wdm_rxwork);
 650
 651         rv = -EINVAL;
 652         iface = intf->cur_altsetting;
 653         if (iface->desc.bNumEndpoints != 1)
 654                 goto err;
 655         ep = &iface->endpoint[0].desc;
 656         if (!ep || !usb_endpoint_is_int_in(ep))
 657                 goto err;
 658
 659         desc->wMaxPacketSize = le16_to_cpu(ep->wMaxPacketSize);
 660         desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0;
 661
 662         desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 663         if (!desc->orq)
 664                 goto err;
 665         desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 666         if (!desc->irq)
 667                 goto err;
 668
 669         desc->validity = usb_alloc_urb(0, GFP_KERNEL);
 670         if (!desc->validity)
 671                 goto err;
 672
 673         desc->response = usb_alloc_urb(0, GFP_KERNEL);
 674         if (!desc->response)
 675                 goto err;
 676
 677         desc->command = usb_alloc_urb(0, GFP_KERNEL);
 678         if (!desc->command)
 679                 goto err;
 680
 681         desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
 682         if (!desc->ubuf)
 683                 goto err;
 684
 685         desc->sbuf = usb_buffer_alloc(interface_to_usbdev(intf),
 686                                         desc->wMaxPacketSize,
 687                                         GFP_KERNEL,
 688                                         &desc->validity->transfer_dma);
 689         if (!desc->sbuf)
 690                 goto err;
 691
 692         desc->inbuf = usb_buffer_alloc(interface_to_usbdev(intf),
 693                                         desc->bMaxPacketSize0,
 694                                         GFP_KERNEL,
 695                                         &desc->response->transfer_dma);
 696         if (!desc->inbuf)
 697                 goto err2;
 698
 699         usb_fill_int_urb(
 700                 desc->validity,
 701                 interface_to_usbdev(intf),
 702                 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
 703                 desc->sbuf,
 704                 desc->wMaxPacketSize,
 705                 wdm_int_callback,
 706                 desc,
 707                 ep->bInterval
 708         );
 709         desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 710
 711         usb_set_intfdata(intf, desc);
 712         rv = usb_register_dev(intf, &wdm_class);
 713         if (rv < 0)
 714                 goto err3;
 715         else
 716                 dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
 717                         intf->minor - WDM_MINOR_BASE);
 718 out:
 719         return rv;
 720 err3:
 721         usb_set_intfdata(intf, NULL);
 722         usb_buffer_free(interface_to_usbdev(desc->intf),
 723                         desc->bMaxPacketSize0,
 724                         desc->inbuf,
 725                         desc->response->transfer_dma);
 726 err2:
 727         usb_buffer_free(interface_to_usbdev(desc->intf),
 728                         desc->wMaxPacketSize,
 729                         desc->sbuf,
 730                         desc->validity->transfer_dma);
 731 err:
 732         free_urbs(desc);
 733         kfree(desc->ubuf);
 734         kfree(desc->orq);
 735         kfree(desc->irq);
 736         kfree(desc);
 737         return rv;
 738 }
 739
 740 static void wdm_disconnect(struct usb_interface *intf)
 741 {
 742         struct wdm_device *desc;
 743         unsigned long flags;
 744
 745         usb_deregister_dev(intf, &wdm_class);
 746         mutex_lock(&wdm_mutex);
 747         desc = usb_get_intfdata(intf);
 748
 749         /* the spinlock makes sure no new urbs are generated in the callbacks */
 750         spin_lock_irqsave(&desc->iuspin, flags);
 751         set_bit(WDM_DISCONNECTING, &desc->flags);
 752         set_bit(WDM_READ, &desc->flags);
 753         /* to terminate pending flushes */
 754         clear_bit(WDM_IN_USE, &desc->flags);
 755         spin_unlock_irqrestore(&desc->iuspin, flags);
 756         cancel_work_sync(&desc->rxwork);
 757         kill_urbs(desc);
 758         wake_up_all(&desc->wait);
 759         if (!desc->count)
 760                 cleanup(desc);
 761         mutex_unlock(&wdm_mutex);
 762 }
 763
 764 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
 765 {
 766         struct wdm_device *desc = usb_get_intfdata(intf);
 767         int rv = 0;
 768
 769         dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
 770
 771         mutex_lock(&desc->plock);
 772 #ifdef CONFIG_PM
 773         if ((message.event & PM_EVENT_AUTO) &&
 774                         test_bit(WDM_IN_USE, &desc->flags)) {
 775                 rv = -EBUSY;
 776         } else {
 777 #endif
 778                 cancel_work_sync(&desc->rxwork);
 779                 kill_urbs(desc);
 780 #ifdef CONFIG_PM
 781         }
 782 #endif
 783         mutex_unlock(&desc->plock);
 784
 785         return rv;
 786 }
 787
 788 static int recover_from_urb_loss(struct wdm_device *desc)
 789 {
 790         int rv = 0;
 791
 792         if (desc->count) {
 793                 rv = usb_submit_urb(desc->validity, GFP_NOIO);
 794                 if (rv < 0)
 795                         dev_err(&desc->intf->dev,
 796                                 "Error resume submitting int urb - %d\n", rv);
 797         }
 798         return rv;
 799 }
 800 static int wdm_resume(struct usb_interface *intf)
 801 {
 802         struct wdm_device *desc = usb_get_intfdata(intf);
 803         int rv;
 804
 805         dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
 806         mutex_lock(&desc->plock);
 807         rv = recover_from_urb_loss(desc);
 808         mutex_unlock(&desc->plock);
 809         return rv;
 810 }
 811
 812 static int wdm_pre_reset(struct usb_interface *intf)
 813 {
 814         struct wdm_device *desc = usb_get_intfdata(intf);
 815
 816         mutex_lock(&desc->plock);
 817         return 0;
 818 }
 819
 820 static int wdm_post_reset(struct usb_interface *intf)
 821 {
 822         struct wdm_device *desc = usb_get_intfdata(intf);
 823         int rv;
 824
 825         rv = recover_from_urb_loss(desc);
 826         mutex_unlock(&desc->plock);
 827         return 0;
 828 }
 829
 830 static struct usb_driver wdm_driver = {
 831         .name =         "cdc_wdm",
 832         .probe =        wdm_probe,
 833         .disconnect =   wdm_disconnect,
 834         .suspend =      wdm_suspend,
 835         .resume =       wdm_resume,
 836         .reset_resume = wdm_resume,
 837         .pre_reset =    wdm_pre_reset,
 838         .post_reset =   wdm_post_reset,
 839         .id_table =     wdm_ids,
 840         .supports_autosuspend = 1,
 841 };
 842
 843 /* --- low level module stuff --- */
 844
 845 static int __init wdm_init(void)
 846 {
 847         int rv;
 848
 849         rv = usb_register(&wdm_driver);
 850
 851         return rv;
 852 }
 853
 854 static void __exit wdm_exit(void)
 855 {
 856         usb_deregister(&wdm_driver);
 857 }
 858
 859 module_init(wdm_init);
 860 module_exit(wdm_exit);
 861
 862 MODULE_AUTHOR(DRIVER_AUTHOR);
 863 MODULE_DESCRIPTION(DRIVER_DESC);
 864 MODULE_LICENSE("GPL");