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) 2007-2008 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/smp_lock.h>
  19 #include <linux/mutex.h>
  20 #include <linux/uaccess.h>
  21 #include <linux/bitops.h>
  22 #include <linux/poll.h>
  23 #include <linux/usb.h>
  24 #include <linux/usb/cdc.h>
  25 #include <asm/byteorder.h>
  26 #include <asm/unaligned.h>
  27
  28 /*
  29  * Version Information
  30  */
  31 #define DRIVER_VERSION "v0.03"
  32 #define DRIVER_AUTHOR "Oliver Neukum"
  33 #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management"
  34
  35 static struct usb_device_id wdm_ids[] = {
  36         {
  37                 .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS |
  38                                  USB_DEVICE_ID_MATCH_INT_SUBCLASS,
  39                 .bInterfaceClass = USB_CLASS_COMM,
  40                 .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM
  41         },
  42         { }
  43 };
  44
  45 #define WDM_MINOR_BASE  176
  46
  47
  48 #define WDM_IN_USE              1
  49 #define WDM_DISCONNECTING       2
  50 #define WDM_RESULT              3
  51 #define WDM_READ                4
  52 #define WDM_INT_STALL           5
  53 #define WDM_POLL_RUNNING        6
  54
  55
  56 #define WDM_MAX                 16
  57
  58
  59 static DEFINE_MUTEX(wdm_mutex);
  60
  61 /* --- method tables --- */
  62
  63 struct wdm_device {
  64         u8                      *inbuf; /* buffer for response */
  65         u8                      *outbuf; /* buffer for command */
  66         u8                      *sbuf; /* buffer for status */
  67         u8                      *ubuf; /* buffer for copy to user space */
  68
  69         struct urb              *command;
  70         struct urb              *response;
  71         struct urb              *validity;
  72         struct usb_interface    *intf;
  73         struct usb_ctrlrequest  *orq;
  74         struct usb_ctrlrequest  *irq;
  75         spinlock_t              iuspin;
  76
  77         unsigned long           flags;
  78         u16                     bufsize;
  79         u16                     wMaxCommand;
  80         u16                     wMaxPacketSize;
  81         u16                     bMaxPacketSize0;
  82         __le16                  inum;
  83         int                     reslength;
  84         int                     length;
  85         int                     read;
  86         int                     count;
  87         dma_addr_t              shandle;
  88         dma_addr_t              ihandle;
  89         struct mutex            wlock;
  90         struct mutex            rlock;
  91         struct mutex            plock;
  92         wait_queue_head_t       wait;
  93         struct work_struct      rxwork;
  94         int                     werr;
  95         int                     rerr;
  96 };
  97
  98 static struct usb_driver wdm_driver;
  99
 100 /* --- callbacks --- */
 101 static void wdm_out_callback(struct urb *urb)
 102 {
 103         struct wdm_device *desc;
 104         desc = urb->context;
 105         spin_lock(&desc->iuspin);
 106         desc->werr = urb->status;
 107         spin_unlock(&desc->iuspin);
 108         clear_bit(WDM_IN_USE, &desc->flags);
 109         kfree(desc->outbuf);
 110         wake_up(&desc->wait);
 111 }
 112
 113 static void wdm_in_callback(struct urb *urb)
 114 {
 115         struct wdm_device *desc = urb->context;
 116         int status = urb->status;
 117
 118         spin_lock(&desc->iuspin);
 119
 120         if (status) {
 121                 switch (status) {
 122                 case -ENOENT:
 123                         dev_dbg(&desc->intf->dev,
 124                                 "nonzero urb status received: -ENOENT");
 125                         break;
 126                 case -ECONNRESET:
 127                         dev_dbg(&desc->intf->dev,
 128                                 "nonzero urb status received: -ECONNRESET");
 129                         break;
 130                 case -ESHUTDOWN:
 131                         dev_dbg(&desc->intf->dev,
 132                                 "nonzero urb status received: -ESHUTDOWN");
 133                         break;
 134                 case -EPIPE:
 135                         err("nonzero urb status received: -EPIPE");
 136                         break;
 137                 default:
 138                         err("Unexpected error %d", status);
 139                         break;
 140                 }
 141         }
 142
 143         desc->rerr = status;
 144         desc->reslength = urb->actual_length;
 145         memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
 146         desc->length += desc->reslength;
 147         wake_up(&desc->wait);
 148
 149         set_bit(WDM_READ, &desc->flags);
 150         spin_unlock(&desc->iuspin);
 151 }
 152
 153 static void wdm_int_callback(struct urb *urb)
 154 {
 155         int rv = 0;
 156         int status = urb->status;
 157         struct wdm_device *desc;
 158         struct usb_ctrlrequest *req;
 159         struct usb_cdc_notification *dr;
 160
 161         desc = urb->context;
 162         req = desc->irq;
 163         dr = (struct usb_cdc_notification *)desc->sbuf;
 164
 165         if (status) {
 166                 switch (status) {
 167                 case -ESHUTDOWN:
 168                 case -ENOENT:
 169                 case -ECONNRESET:
 170                         return; /* unplug */
 171                 case -EPIPE:
 172                         set_bit(WDM_INT_STALL, &desc->flags);
 173                         err("Stall on int endpoint");
 174                         goto sw; /* halt is cleared in work */
 175                 default:
 176                         err("nonzero urb status received: %d", status);
 177                         break;
 178                 }
 179         }
 180
 181         if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
 182                 err("wdm_int_callback - %d bytes", urb->actual_length);
 183                 goto exit;
 184         }
 185
 186         switch (dr->bNotificationType) {
 187         case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
 188                 dev_dbg(&desc->intf->dev,
 189                         "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
 190                         dr->wIndex, dr->wLength);
 191                 break;
 192
 193         case USB_CDC_NOTIFY_NETWORK_CONNECTION:
 194
 195                 dev_dbg(&desc->intf->dev,
 196                         "NOTIFY_NETWORK_CONNECTION %s network",
 197                         dr->wValue ? "connected to" : "disconnected from");
 198                 goto exit;
 199         default:
 200                 clear_bit(WDM_POLL_RUNNING, &desc->flags);
 201                 err("unknown notification %d received: index %d len %d",
 202                         dr->bNotificationType, dr->wIndex, dr->wLength);
 203                 goto exit;
 204         }
 205
 206         req->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
 207         req->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
 208         req->wValue = 0;
 209         req->wIndex = desc->inum;
 210         req->wLength = cpu_to_le16(desc->wMaxCommand);
 211
 212         usb_fill_control_urb(
 213                 desc->response,
 214                 interface_to_usbdev(desc->intf),
 215                 /* using common endpoint 0 */
 216                 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
 217                 (unsigned char *)req,
 218                 desc->inbuf,
 219                 desc->wMaxCommand,
 220                 wdm_in_callback,
 221                 desc
 222         );
 223         desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 224         spin_lock(&desc->iuspin);
 225         clear_bit(WDM_READ, &desc->flags);
 226         if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
 227                 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
 228                 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
 229                         __func__, rv);
 230         }
 231         spin_unlock(&desc->iuspin);
 232         if (rv < 0) {
 233                 if (rv == -EPERM)
 234                         return;
 235                 if (rv == -ENOMEM) {
 236 sw:
 237                         rv = schedule_work(&desc->rxwork);
 238                         if (rv)
 239                                 err("Cannot schedule work");
 240                 }
 241         }
 242 exit:
 243         rv = usb_submit_urb(urb, GFP_ATOMIC);
 244         if (rv)
 245                 err("%s - usb_submit_urb failed with result %d",
 246                      __func__, rv);
 247
 248 }
 249
 250 static void kill_urbs(struct wdm_device *desc)
 251 {
 252         /* the order here is essential */
 253         usb_kill_urb(desc->command);
 254         usb_kill_urb(desc->validity);
 255         usb_kill_urb(desc->response);
 256 }
 257
 258 static void free_urbs(struct wdm_device *desc)
 259 {
 260         usb_free_urb(desc->validity);
 261         usb_free_urb(desc->response);
 262         usb_free_urb(desc->command);
 263 }
 264
 265 static void cleanup(struct wdm_device *desc)
 266 {
 267         usb_buffer_free(interface_to_usbdev(desc->intf),
 268                         desc->wMaxPacketSize,
 269                         desc->sbuf,
 270                         desc->validity->transfer_dma);
 271         usb_buffer_free(interface_to_usbdev(desc->intf),
 272                         desc->wMaxCommand,
 273                         desc->inbuf,
 274                         desc->response->transfer_dma);
 275         kfree(desc->orq);
 276         kfree(desc->irq);
 277         kfree(desc->ubuf);
 278         free_urbs(desc);
 279         kfree(desc);
 280 }
 281
 282 static ssize_t wdm_write
 283 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 284 {
 285         u8 *buf;
 286         int rv = -EMSGSIZE, r, we;
 287         struct wdm_device *desc = file->private_data;
 288         struct usb_ctrlrequest *req;
 289
 290         if (count > desc->wMaxCommand)
 291                 count = desc->wMaxCommand;
 292
 293         spin_lock_irq(&desc->iuspin);
 294         we = desc->werr;
 295         desc->werr = 0;
 296         spin_unlock_irq(&desc->iuspin);
 297         if (we < 0)
 298                 return -EIO;
 299
 300         r = mutex_lock_interruptible(&desc->wlock); /* concurrent writes */
 301         rv = -ERESTARTSYS;
 302         if (r)
 303                 goto outnl;
 304
 305         r = usb_autopm_get_interface(desc->intf);
 306         if (r < 0)
 307                 goto outnp;
 308         r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
 309                                                            &desc->flags));
 310         if (r < 0)
 311                 goto out;
 312
 313         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 314                 rv = -ENODEV;
 315                 goto out;
 316         }
 317
 318         desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
 319         if (!buf) {
 320                 rv = -ENOMEM;
 321                 goto out;
 322         }
 323
 324         r = copy_from_user(buf, buffer, count);
 325         if (r > 0) {
 326                 kfree(buf);
 327                 rv = -EFAULT;
 328                 goto out;
 329         }
 330
 331         req = desc->orq;
 332         usb_fill_control_urb(
 333                 desc->command,
 334                 interface_to_usbdev(desc->intf),
 335                 /* using common endpoint 0 */
 336                 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
 337                 (unsigned char *)req,
 338                 buf,
 339                 count,
 340                 wdm_out_callback,
 341                 desc
 342         );
 343
 344         req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
 345                              USB_RECIP_INTERFACE);
 346         req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
 347         req->wValue = 0;
 348         req->wIndex = desc->inum;
 349         req->wLength = cpu_to_le16(count);
 350         set_bit(WDM_IN_USE, &desc->flags);
 351
 352         rv = usb_submit_urb(desc->command, GFP_KERNEL);
 353         if (rv < 0) {
 354                 kfree(buf);
 355                 clear_bit(WDM_IN_USE, &desc->flags);
 356                 err("Tx URB error: %d", rv);
 357         } else {
 358                 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
 359                         req->wIndex);
 360         }
 361 out:
 362         usb_autopm_put_interface(desc->intf);
 363 outnp:
 364         mutex_unlock(&desc->wlock);
 365 outnl:
 366         return rv < 0 ? rv : count;
 367 }
 368
 369 static ssize_t wdm_read
 370 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 371 {
 372         int rv, cntr;
 373         int i = 0;
 374         struct wdm_device *desc = file->private_data;
 375
 376
 377         rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
 378         if (rv < 0)
 379                 return -ERESTARTSYS;
 380
 381         if (desc->length == 0) {
 382                 desc->read = 0;
 383 retry:
 384                 i++;
 385                 rv = wait_event_interruptible(desc->wait,
 386                                               test_bit(WDM_READ, &desc->flags));
 387
 388                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 389                         rv = -ENODEV;
 390                         goto err;
 391                 }
 392                 usb_mark_last_busy(interface_to_usbdev(desc->intf));
 393                 if (rv < 0) {
 394                         rv = -ERESTARTSYS;
 395                         goto err;
 396                 }
 397
 398                 spin_lock_irq(&desc->iuspin);
 399
 400                 if (desc->rerr) { /* read completed, error happened */
 401                         int t = desc->rerr;
 402                         desc->rerr = 0;
 403                         spin_unlock_irq(&desc->iuspin);
 404                         err("reading had resulted in %d", t);
 405                         rv = -EIO;
 406                         goto err;
 407                 }
 408                 /*
 409                  * recheck whether we've lost the race
 410                  * against the completion handler
 411                  */
 412                 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
 413                         spin_unlock_irq(&desc->iuspin);
 414                         goto retry;
 415                 }
 416                 if (!desc->reslength) { /* zero length read */
 417                         spin_unlock_irq(&desc->iuspin);
 418                         goto retry;
 419                 }
 420                 clear_bit(WDM_READ, &desc->flags);
 421                 spin_unlock_irq(&desc->iuspin);
 422         }
 423
 424         cntr = count > desc->length ? desc->length : count;
 425         rv = copy_to_user(buffer, desc->ubuf, cntr);
 426         if (rv > 0) {
 427                 rv = -EFAULT;
 428                 goto err;
 429         }
 430
 431         for (i = 0; i < desc->length - cntr; i++)
 432                 desc->ubuf[i] = desc->ubuf[i + cntr];
 433
 434         desc->length -= cntr;
 435         /* in case we had outstanding data */
 436         if (!desc->length)
 437                 clear_bit(WDM_READ, &desc->flags);
 438         rv = cntr;
 439
 440 err:
 441         mutex_unlock(&desc->rlock);
 442         if (rv < 0)
 443                 err("wdm_read: exit error");
 444         return rv;
 445 }
 446
 447 static int wdm_flush(struct file *file, fl_owner_t id)
 448 {
 449         struct wdm_device *desc = file->private_data;
 450
 451         wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
 452         if (desc->werr < 0)
 453                 err("Error in flush path: %d", desc->werr);
 454
 455         return desc->werr;
 456 }
 457
 458 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
 459 {
 460         struct wdm_device *desc = file->private_data;
 461         unsigned long flags;
 462         unsigned int mask = 0;
 463
 464         spin_lock_irqsave(&desc->iuspin, flags);
 465         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 466                 mask = POLLERR;
 467                 spin_unlock_irqrestore(&desc->iuspin, flags);
 468                 goto desc_out;
 469         }
 470         if (test_bit(WDM_READ, &desc->flags))
 471                 mask = POLLIN | POLLRDNORM;
 472         if (desc->rerr || desc->werr)
 473                 mask |= POLLERR;
 474         if (!test_bit(WDM_IN_USE, &desc->flags))
 475                 mask |= POLLOUT | POLLWRNORM;
 476         spin_unlock_irqrestore(&desc->iuspin, flags);
 477
 478         poll_wait(file, &desc->wait, wait);
 479
 480 desc_out:
 481         return mask;
 482 }
 483
 484 static int wdm_open(struct inode *inode, struct file *file)
 485 {
 486         int minor = iminor(inode);
 487         int rv = -ENODEV;
 488         struct usb_interface *intf;
 489         struct wdm_device *desc;
 490
 491         mutex_lock(&wdm_mutex);
 492         intf = usb_find_interface(&wdm_driver, minor);
 493         if (!intf)
 494                 goto out;
 495
 496         desc = usb_get_intfdata(intf);
 497         if (test_bit(WDM_DISCONNECTING, &desc->flags))
 498                 goto out;
 499
 500         ;
 501         file->private_data = desc;
 502
 503         rv = usb_autopm_get_interface(desc->intf);
 504         if (rv < 0) {
 505                 err("Error autopm - %d", rv);
 506                 goto out;
 507         }
 508         intf->needs_remote_wakeup = 1;
 509
 510         mutex_lock(&desc->plock);
 511         if (!desc->count++) {
 512                 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
 513                 if (rv < 0) {
 514                         desc->count--;
 515                         err("Error submitting int urb - %d", rv);
 516                 }
 517         } else {
 518                 rv = 0;
 519         }
 520         mutex_unlock(&desc->plock);
 521         usb_autopm_put_interface(desc->intf);
 522 out:
 523         mutex_unlock(&wdm_mutex);
 524         return rv;
 525 }
 526
 527 static int wdm_release(struct inode *inode, struct file *file)
 528 {
 529         struct wdm_device *desc = file->private_data;
 530
 531         mutex_lock(&wdm_mutex);
 532         mutex_lock(&desc->plock);
 533         desc->count--;
 534         mutex_unlock(&desc->plock);
 535
 536         if (!desc->count) {
 537                 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
 538                 kill_urbs(desc);
 539                 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 540                         desc->intf->needs_remote_wakeup = 0;
 541         }
 542         mutex_unlock(&wdm_mutex);
 543         return 0;
 544 }
 545
 546 static const struct file_operations wdm_fops = {
 547         .owner =        THIS_MODULE,
 548         .read =         wdm_read,
 549         .write =        wdm_write,
 550         .open =         wdm_open,
 551         .flush =        wdm_flush,
 552         .release =      wdm_release,
 553         .poll =         wdm_poll
 554 };
 555
 556 static struct usb_class_driver wdm_class = {
 557         .name =         "cdc-wdm%d",
 558         .fops =         &wdm_fops,
 559         .minor_base =   WDM_MINOR_BASE,
 560 };
 561
 562 /* --- error handling --- */
 563 static void wdm_rxwork(struct work_struct *work)
 564 {
 565         struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
 566         unsigned long flags;
 567         int rv;
 568
 569         spin_lock_irqsave(&desc->iuspin, flags);
 570         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 571                 spin_unlock_irqrestore(&desc->iuspin, flags);
 572         } else {
 573                 spin_unlock_irqrestore(&desc->iuspin, flags);
 574                 rv = usb_submit_urb(desc->response, GFP_KERNEL);
 575                 if (rv < 0 && rv != -EPERM) {
 576                         spin_lock_irqsave(&desc->iuspin, flags);
 577                         if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 578                                 schedule_work(&desc->rxwork);
 579                         spin_unlock_irqrestore(&desc->iuspin, flags);
 580                 }
 581         }
 582 }
 583
 584 /* --- hotplug --- */
 585
 586 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
 587 {
 588         int rv = -EINVAL;
 589         struct usb_device *udev = interface_to_usbdev(intf);
 590         struct wdm_device *desc;
 591         struct usb_host_interface *iface;
 592         struct usb_endpoint_descriptor *ep;
 593         struct usb_cdc_dmm_desc *dmhd;
 594         u8 *buffer = intf->altsetting->extra;
 595         int buflen = intf->altsetting->extralen;
 596         u16 maxcom = 0;
 597
 598         if (!buffer)
 599                 goto out;
 600
 601         while (buflen > 0) {
 602                 if (buffer [1] != USB_DT_CS_INTERFACE) {
 603                         err("skipping garbage");
 604                         goto next_desc;
 605                 }
 606
 607                 switch (buffer [2]) {
 608                 case USB_CDC_HEADER_TYPE:
 609                         break;
 610                 case USB_CDC_DMM_TYPE:
 611                         dmhd = (struct usb_cdc_dmm_desc *)buffer;
 612                         maxcom = le16_to_cpu(dmhd->wMaxCommand);
 613                         dev_dbg(&intf->dev,
 614                                 "Finding maximum buffer length: %d", maxcom);
 615                         break;
 616                 default:
 617                         err("Ignoring extra header, type %d, length %d",
 618                                 buffer[2], buffer[0]);
 619                         break;
 620                 }
 621 next_desc:
 622                 buflen -= buffer[0];
 623                 buffer += buffer[0];
 624         }
 625
 626         rv = -ENOMEM;
 627         desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
 628         if (!desc)
 629                 goto out;
 630         mutex_init(&desc->wlock);
 631         mutex_init(&desc->rlock);
 632         mutex_init(&desc->plock);
 633         spin_lock_init(&desc->iuspin);
 634         init_waitqueue_head(&desc->wait);
 635         desc->wMaxCommand = maxcom;
 636         desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
 637         desc->intf = intf;
 638         INIT_WORK(&desc->rxwork, wdm_rxwork);
 639
 640         iface = &intf->altsetting[0];
 641         ep = &iface->endpoint[0].desc;
 642         if (!usb_endpoint_is_int_in(ep)) {
 643                 rv = -EINVAL;
 644                 goto err;
 645         }
 646
 647         desc->wMaxPacketSize = le16_to_cpu(ep->wMaxPacketSize);
 648         desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0;
 649
 650         desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 651         if (!desc->orq)
 652                 goto err;
 653         desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 654         if (!desc->irq)
 655                 goto err;
 656
 657         desc->validity = usb_alloc_urb(0, GFP_KERNEL);
 658         if (!desc->validity)
 659                 goto err;
 660
 661         desc->response = usb_alloc_urb(0, GFP_KERNEL);
 662         if (!desc->response)
 663                 goto err;
 664
 665         desc->command = usb_alloc_urb(0, GFP_KERNEL);
 666         if (!desc->command)
 667                 goto err;
 668
 669         desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
 670         if (!desc->ubuf)
 671                 goto err;
 672
 673         desc->sbuf = usb_buffer_alloc(interface_to_usbdev(intf),
 674                                         desc->wMaxPacketSize,
 675                                         GFP_KERNEL,
 676                                         &desc->validity->transfer_dma);
 677         if (!desc->sbuf)
 678                 goto err;
 679
 680         desc->inbuf = usb_buffer_alloc(interface_to_usbdev(intf),
 681                                         desc->bMaxPacketSize0,
 682                                         GFP_KERNEL,
 683                                         &desc->response->transfer_dma);
 684         if (!desc->inbuf)
 685                 goto err2;
 686
 687         usb_fill_int_urb(
 688                 desc->validity,
 689                 interface_to_usbdev(intf),
 690                 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
 691                 desc->sbuf,
 692                 desc->wMaxPacketSize,
 693                 wdm_int_callback,
 694                 desc,
 695                 ep->bInterval
 696         );
 697         desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 698
 699         usb_set_intfdata(intf, desc);
 700         rv = usb_register_dev(intf, &wdm_class);
 701         dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
 702                  intf->minor - WDM_MINOR_BASE);
 703         if (rv < 0)
 704                 goto err;
 705 out:
 706         return rv;
 707 err2:
 708         usb_buffer_free(interface_to_usbdev(desc->intf),
 709                         desc->wMaxPacketSize,
 710                         desc->sbuf,
 711                         desc->validity->transfer_dma);
 712 err:
 713         free_urbs(desc);
 714         kfree(desc->ubuf);
 715         kfree(desc->orq);
 716         kfree(desc->irq);
 717         kfree(desc);
 718         return rv;
 719 }
 720
 721 static void wdm_disconnect(struct usb_interface *intf)
 722 {
 723         struct wdm_device *desc;
 724         unsigned long flags;
 725
 726         usb_deregister_dev(intf, &wdm_class);
 727         mutex_lock(&wdm_mutex);
 728         desc = usb_get_intfdata(intf);
 729
 730         /* the spinlock makes sure no new urbs are generated in the callbacks */
 731         spin_lock_irqsave(&desc->iuspin, flags);
 732         set_bit(WDM_DISCONNECTING, &desc->flags);
 733         set_bit(WDM_READ, &desc->flags);
 734         /* to terminate pending flushes */
 735         clear_bit(WDM_IN_USE, &desc->flags);
 736         spin_unlock_irqrestore(&desc->iuspin, flags);
 737         cancel_work_sync(&desc->rxwork);
 738         kill_urbs(desc);
 739         wake_up_all(&desc->wait);
 740         if (!desc->count)
 741                 cleanup(desc);
 742         mutex_unlock(&wdm_mutex);
 743 }
 744
 745 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
 746 {
 747         struct wdm_device *desc = usb_get_intfdata(intf);
 748         int rv = 0;
 749
 750         dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
 751
 752         mutex_lock(&desc->plock);
 753 #ifdef CONFIG_PM
 754         if (interface_to_usbdev(desc->intf)->auto_pm && test_bit(WDM_IN_USE, &desc->flags)) {
 755                 rv = -EBUSY;
 756         } else {
 757 #endif
 758                 cancel_work_sync(&desc->rxwork);
 759                 kill_urbs(desc);
 760 #ifdef CONFIG_PM
 761         }
 762 #endif
 763         mutex_unlock(&desc->plock);
 764
 765         return rv;
 766 }
 767
 768 static int recover_from_urb_loss(struct wdm_device *desc)
 769 {
 770         int rv = 0;
 771
 772         if (desc->count) {
 773                 rv = usb_submit_urb(desc->validity, GFP_NOIO);
 774                 if (rv < 0)
 775                         err("Error resume submitting int urb - %d", rv);
 776         }
 777         return rv;
 778 }
 779 static int wdm_resume(struct usb_interface *intf)
 780 {
 781         struct wdm_device *desc = usb_get_intfdata(intf);
 782         int rv;
 783
 784         dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
 785         mutex_lock(&desc->plock);
 786         rv = recover_from_urb_loss(desc);
 787         mutex_unlock(&desc->plock);
 788         return rv;
 789 }
 790
 791 static int wdm_pre_reset(struct usb_interface *intf)
 792 {
 793         struct wdm_device *desc = usb_get_intfdata(intf);
 794
 795         mutex_lock(&desc->plock);
 796         return 0;
 797 }
 798
 799 static int wdm_post_reset(struct usb_interface *intf)
 800 {
 801         struct wdm_device *desc = usb_get_intfdata(intf);
 802         int rv;
 803
 804         rv = recover_from_urb_loss(desc);
 805         mutex_unlock(&desc->plock);
 806         return 0;
 807 }
 808
 809 static struct usb_driver wdm_driver = {
 810         .name =         "cdc_wdm",
 811         .probe =        wdm_probe,
 812         .disconnect =   wdm_disconnect,
 813         .suspend =      wdm_suspend,
 814         .resume =       wdm_resume,
 815         .reset_resume = wdm_resume,
 816         .pre_reset =    wdm_pre_reset,
 817         .post_reset =   wdm_post_reset,
 818         .id_table =     wdm_ids,
 819         .supports_autosuspend = 1,
 820 };
 821
 822 /* --- low level module stuff --- */
 823
 824 static int __init wdm_init(void)
 825 {
 826         int rv;
 827
 828         rv = usb_register(&wdm_driver);
 829
 830         return rv;
 831 }
 832
 833 static void __exit wdm_exit(void)
 834 {
 835         usb_deregister(&wdm_driver);
 836 }
 837
 838 module_init(wdm_init);
 839 module_exit(wdm_exit);
 840
 841 MODULE_AUTHOR(DRIVER_AUTHOR);
 842 MODULE_DESCRIPTION(DRIVER_DESC);
 843 MODULE_LICENSE("GPL");