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