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->bMaxPacketSize0,
 281                         desc->inbuf,
 282                         desc->response->transfer_dma);
 283         kfree(desc->orq);
 284         kfree(desc->irq);
 285         kfree(desc->ubuf);
 286         free_urbs(desc);
 287         kfree(desc);
 288 }
 289
 290 static ssize_t wdm_write
 291 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 292 {
 293         u8 *buf;
 294         int rv = -EMSGSIZE, r, we;
 295         struct wdm_device *desc = file->private_data;
 296         struct usb_ctrlrequest *req;
 297
 298         if (count > desc->wMaxCommand)
 299                 count = desc->wMaxCommand;
 300
 301         spin_lock_irq(&desc->iuspin);
 302         we = desc->werr;
 303         desc->werr = 0;
 304         spin_unlock_irq(&desc->iuspin);
 305         if (we < 0)
 306                 return -EIO;
 307
 308         r = mutex_lock_interruptible(&desc->wlock); /* concurrent writes */
 309         rv = -ERESTARTSYS;
 310         if (r)
 311                 goto outnl;
 312
 313         r = usb_autopm_get_interface(desc->intf);
 314         if (r < 0)
 315                 goto outnp;
 316
 317         if (!(file->f_flags & O_NONBLOCK))
 318                 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
 319                                                                 &desc->flags));
 320         else
 321                 if (test_bit(WDM_IN_USE, &desc->flags))
 322                         r = -EAGAIN;
 323         if (r < 0)
 324                 goto out;
 325
 326         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 327                 rv = -ENODEV;
 328                 goto out;
 329         }
 330
 331         desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
 332         if (!buf) {
 333                 rv = -ENOMEM;
 334                 goto out;
 335         }
 336
 337         r = copy_from_user(buf, buffer, count);
 338         if (r > 0) {
 339                 kfree(buf);
 340                 rv = -EFAULT;
 341                 goto out;
 342         }
 343
 344         req = desc->orq;
 345         usb_fill_control_urb(
 346                 desc->command,
 347                 interface_to_usbdev(desc->intf),
 348                 /* using common endpoint 0 */
 349                 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
 350                 (unsigned char *)req,
 351                 buf,
 352                 count,
 353                 wdm_out_callback,
 354                 desc
 355         );
 356
 357         req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
 358                              USB_RECIP_INTERFACE);
 359         req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
 360         req->wValue = 0;
 361         req->wIndex = desc->inum;
 362         req->wLength = cpu_to_le16(count);
 363         set_bit(WDM_IN_USE, &desc->flags);
 364
 365         rv = usb_submit_urb(desc->command, GFP_KERNEL);
 366         if (rv < 0) {
 367                 kfree(buf);
 368                 clear_bit(WDM_IN_USE, &desc->flags);
 369                 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
 370         } else {
 371                 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
 372                         req->wIndex);
 373         }
 374 out:
 375         usb_autopm_put_interface(desc->intf);
 376 outnp:
 377         mutex_unlock(&desc->wlock);
 378 outnl:
 379         return rv < 0 ? rv : count;
 380 }
 381
 382 static ssize_t wdm_read
 383 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 384 {
 385         int rv, cntr = 0;
 386         int i = 0;
 387         struct wdm_device *desc = file->private_data;
 388
 389
 390         rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
 391         if (rv < 0)
 392                 return -ERESTARTSYS;
 393
 394         if (desc->length == 0) {
 395                 desc->read = 0;
 396 retry:
 397                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 398                         rv = -ENODEV;
 399                         goto err;
 400                 }
 401                 i++;
 402                 if (file->f_flags & O_NONBLOCK) {
 403                         if (!test_bit(WDM_READ, &desc->flags)) {
 404                                 rv = cntr ? cntr : -EAGAIN;
 405                                 goto err;
 406                         }
 407                         rv = 0;
 408                 } else {
 409                         rv = wait_event_interruptible(desc->wait,
 410                                 test_bit(WDM_READ, &desc->flags));
 411                 }
 412
 413                 /* may have happened while we slept */
 414                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 415                         rv = -ENODEV;
 416                         goto err;
 417                 }
 418                 usb_mark_last_busy(interface_to_usbdev(desc->intf));
 419                 if (rv < 0) {
 420                         rv = -ERESTARTSYS;
 421                         goto err;
 422                 }
 423
 424                 spin_lock_irq(&desc->iuspin);
 425
 426                 if (desc->rerr) { /* read completed, error happened */
 427                         int t = desc->rerr;
 428                         desc->rerr = 0;
 429                         spin_unlock_irq(&desc->iuspin);
 430                         dev_err(&desc->intf->dev,
 431                                 "reading had resulted in %d\n", t);
 432                         rv = -EIO;
 433                         goto err;
 434                 }
 435                 /*
 436                  * recheck whether we've lost the race
 437                  * against the completion handler
 438                  */
 439                 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
 440                         spin_unlock_irq(&desc->iuspin);
 441                         goto retry;
 442                 }
 443                 if (!desc->reslength) { /* zero length read */
 444                         dev_dbg(&desc->intf->dev, "%s: zero length - clearing WDM_READ\n", __func__);
 445                         clear_bit(WDM_READ, &desc->flags);
 446                         spin_unlock_irq(&desc->iuspin);
 447                         goto retry;
 448                 }
 449                 clear_bit(WDM_READ, &desc->flags);
 450                 spin_unlock_irq(&desc->iuspin);
 451         }
 452
 453         cntr = count > desc->length ? desc->length : count;
 454         rv = copy_to_user(buffer, desc->ubuf, cntr);
 455         if (rv > 0) {
 456                 rv = -EFAULT;
 457                 goto err;
 458         }
 459
 460         for (i = 0; i < desc->length - cntr; i++)
 461                 desc->ubuf[i] = desc->ubuf[i + cntr];
 462
 463         spin_lock_irq(&desc->iuspin);
 464         desc->length -= cntr;
 465         spin_unlock_irq(&desc->iuspin);
 466         /* in case we had outstanding data */
 467         if (!desc->length)
 468                 clear_bit(WDM_READ, &desc->flags);
 469         rv = cntr;
 470
 471 err:
 472         mutex_unlock(&desc->rlock);
 473         if (rv < 0 && rv != -EAGAIN)
 474                 dev_err(&desc->intf->dev, "wdm_read: exit error\n");
 475         return rv;
 476 }
 477
 478 static int wdm_flush(struct file *file, fl_owner_t id)
 479 {
 480         struct wdm_device *desc = file->private_data;
 481
 482         wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
 483         if (desc->werr < 0)
 484                 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
 485                         desc->werr);
 486
 487         return desc->werr;
 488 }
 489
 490 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
 491 {
 492         struct wdm_device *desc = file->private_data;
 493         unsigned long flags;
 494         unsigned int mask = 0;
 495
 496         spin_lock_irqsave(&desc->iuspin, flags);
 497         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 498                 mask = POLLERR;
 499                 spin_unlock_irqrestore(&desc->iuspin, flags);
 500                 goto desc_out;
 501         }
 502         if (test_bit(WDM_READ, &desc->flags))
 503                 mask = POLLIN | POLLRDNORM;
 504         if (desc->rerr || desc->werr)
 505                 mask |= POLLERR;
 506         if (!test_bit(WDM_IN_USE, &desc->flags))
 507                 mask |= POLLOUT | POLLWRNORM;
 508         spin_unlock_irqrestore(&desc->iuspin, flags);
 509
 510         poll_wait(file, &desc->wait, wait);
 511
 512 desc_out:
 513         return mask;
 514 }
 515
 516 static int wdm_open(struct inode *inode, struct file *file)
 517 {
 518         int minor = iminor(inode);
 519         int rv = -ENODEV;
 520         struct usb_interface *intf;
 521         struct wdm_device *desc;
 522
 523         mutex_lock(&wdm_mutex);
 524         intf = usb_find_interface(&wdm_driver, minor);
 525         if (!intf)
 526                 goto out;
 527
 528         desc = usb_get_intfdata(intf);
 529         if (test_bit(WDM_DISCONNECTING, &desc->flags))
 530                 goto out;
 531         file->private_data = desc;
 532
 533         rv = usb_autopm_get_interface(desc->intf);
 534         if (rv < 0) {
 535                 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
 536                 goto out;
 537         }
 538         intf->needs_remote_wakeup = 1;
 539
 540         mutex_lock(&desc->plock);
 541         if (!desc->count++) {
 542                 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
 543                 if (rv < 0) {
 544                         desc->count--;
 545                         dev_err(&desc->intf->dev,
 546                                 "Error submitting int urb - %d\n", rv);
 547                 }
 548         } else {
 549                 rv = 0;
 550         }
 551         mutex_unlock(&desc->plock);
 552         usb_autopm_put_interface(desc->intf);
 553 out:
 554         mutex_unlock(&wdm_mutex);
 555         return rv;
 556 }
 557
 558 static int wdm_release(struct inode *inode, struct file *file)
 559 {
 560         struct wdm_device *desc = file->private_data;
 561
 562         mutex_lock(&wdm_mutex);
 563         mutex_lock(&desc->plock);
 564         desc->count--;
 565         mutex_unlock(&desc->plock);
 566
 567         if (!desc->count) {
 568                 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
 569                 kill_urbs(desc);
 570                 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 571                         desc->intf->needs_remote_wakeup = 0;
 572         }
 573         mutex_unlock(&wdm_mutex);
 574         return 0;
 575 }
 576
 577 static const struct file_operations wdm_fops = {
 578         .owner =        THIS_MODULE,
 579         .read =         wdm_read,
 580         .write =        wdm_write,
 581         .open =         wdm_open,
 582         .flush =        wdm_flush,
 583         .release =      wdm_release,
 584         .poll =         wdm_poll
 585 };
 586
 587 static struct usb_class_driver wdm_class = {
 588         .name =         "cdc-wdm%d",
 589         .fops =         &wdm_fops,
 590         .minor_base =   WDM_MINOR_BASE,
 591 };
 592
 593 /* --- error handling --- */
 594 static void wdm_rxwork(struct work_struct *work)
 595 {
 596         struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
 597         unsigned long flags;
 598         int rv;
 599
 600         spin_lock_irqsave(&desc->iuspin, flags);
 601         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 602                 spin_unlock_irqrestore(&desc->iuspin, flags);
 603         } else {
 604                 spin_unlock_irqrestore(&desc->iuspin, flags);
 605                 rv = usb_submit_urb(desc->response, GFP_KERNEL);
 606                 if (rv < 0 && rv != -EPERM) {
 607                         spin_lock_irqsave(&desc->iuspin, flags);
 608                         if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 609                                 schedule_work(&desc->rxwork);
 610                         spin_unlock_irqrestore(&desc->iuspin, flags);
 611                 }
 612         }
 613 }
 614
 615 /* --- hotplug --- */
 616
 617 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
 618 {
 619         int rv = -EINVAL;
 620         struct usb_device *udev = interface_to_usbdev(intf);
 621         struct wdm_device *desc;
 622         struct usb_host_interface *iface;
 623         struct usb_endpoint_descriptor *ep;
 624         struct usb_cdc_dmm_desc *dmhd;
 625         u8 *buffer = intf->altsetting->extra;
 626         int buflen = intf->altsetting->extralen;
 627         u16 maxcom = 0;
 628
 629         if (!buffer)
 630                 goto out;
 631
 632         while (buflen > 2) {
 633                 if (buffer [1] != USB_DT_CS_INTERFACE) {
 634                         dev_err(&intf->dev, "skipping garbage\n");
 635                         goto next_desc;
 636                 }
 637
 638                 switch (buffer [2]) {
 639                 case USB_CDC_HEADER_TYPE:
 640                         break;
 641                 case USB_CDC_DMM_TYPE:
 642                         dmhd = (struct usb_cdc_dmm_desc *)buffer;
 643                         maxcom = le16_to_cpu(dmhd->wMaxCommand);
 644                         dev_dbg(&intf->dev,
 645                                 "Finding maximum buffer length: %d", maxcom);
 646                         break;
 647                 default:
 648                         dev_err(&intf->dev,
 649                                 "Ignoring extra header, type %d, length %d\n",
 650                                 buffer[2], buffer[0]);
 651                         break;
 652                 }
 653 next_desc:
 654                 buflen -= buffer[0];
 655                 buffer += buffer[0];
 656         }
 657
 658         rv = -ENOMEM;
 659         desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
 660         if (!desc)
 661                 goto out;
 662         mutex_init(&desc->wlock);
 663         mutex_init(&desc->rlock);
 664         mutex_init(&desc->plock);
 665         spin_lock_init(&desc->iuspin);
 666         init_waitqueue_head(&desc->wait);
 667         desc->wMaxCommand = maxcom;
 668         /* this will be expanded and needed in hardware endianness */
 669         desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
 670         desc->intf = intf;
 671         INIT_WORK(&desc->rxwork, wdm_rxwork);
 672
 673         rv = -EINVAL;
 674         iface = intf->cur_altsetting;
 675         if (iface->desc.bNumEndpoints != 1)
 676                 goto err;
 677         ep = &iface->endpoint[0].desc;
 678         if (!ep || !usb_endpoint_is_int_in(ep))
 679                 goto err;
 680
 681         desc->wMaxPacketSize = le16_to_cpu(ep->wMaxPacketSize);
 682         desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0;
 683
 684         desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 685         if (!desc->orq)
 686                 goto err;
 687         desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 688         if (!desc->irq)
 689                 goto err;
 690
 691         desc->validity = usb_alloc_urb(0, GFP_KERNEL);
 692         if (!desc->validity)
 693                 goto err;
 694
 695         desc->response = usb_alloc_urb(0, GFP_KERNEL);
 696         if (!desc->response)
 697                 goto err;
 698
 699         desc->command = usb_alloc_urb(0, GFP_KERNEL);
 700         if (!desc->command)
 701                 goto err;
 702
 703         desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
 704         if (!desc->ubuf)
 705                 goto err;
 706
 707         desc->sbuf = usb_buffer_alloc(interface_to_usbdev(intf),
 708                                         desc->wMaxPacketSize,
 709                                         GFP_KERNEL,
 710                                         &desc->validity->transfer_dma);
 711         if (!desc->sbuf)
 712                 goto err;
 713
 714         desc->inbuf = usb_buffer_alloc(interface_to_usbdev(intf),
 715                                         desc->bMaxPacketSize0,
 716                                         GFP_KERNEL,
 717                                         &desc->response->transfer_dma);
 718         if (!desc->inbuf)
 719                 goto err2;
 720
 721         usb_fill_int_urb(
 722                 desc->validity,
 723                 interface_to_usbdev(intf),
 724                 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
 725                 desc->sbuf,
 726                 desc->wMaxPacketSize,
 727                 wdm_int_callback,
 728                 desc,
 729                 ep->bInterval
 730         );
 731         desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 732
 733         usb_set_intfdata(intf, desc);
 734         rv = usb_register_dev(intf, &wdm_class);
 735         if (rv < 0)
 736                 goto err3;
 737         else
 738                 dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
 739                         intf->minor - WDM_MINOR_BASE);
 740 out:
 741         return rv;
 742 err3:
 743         usb_set_intfdata(intf, NULL);
 744         usb_buffer_free(interface_to_usbdev(desc->intf),
 745                         desc->bMaxPacketSize0,
 746                         desc->inbuf,
 747                         desc->response->transfer_dma);
 748 err2:
 749         usb_buffer_free(interface_to_usbdev(desc->intf),
 750                         desc->wMaxPacketSize,
 751                         desc->sbuf,
 752                         desc->validity->transfer_dma);
 753 err:
 754         free_urbs(desc);
 755         kfree(desc->ubuf);
 756         kfree(desc->orq);
 757         kfree(desc->irq);
 758         kfree(desc);
 759         return rv;
 760 }
 761
 762 static void wdm_disconnect(struct usb_interface *intf)
 763 {
 764         struct wdm_device *desc;
 765         unsigned long flags;
 766
 767         usb_deregister_dev(intf, &wdm_class);
 768         mutex_lock(&wdm_mutex);
 769         desc = usb_get_intfdata(intf);
 770
 771         /* the spinlock makes sure no new urbs are generated in the callbacks */
 772         spin_lock_irqsave(&desc->iuspin, flags);
 773         set_bit(WDM_DISCONNECTING, &desc->flags);
 774         set_bit(WDM_READ, &desc->flags);
 775         /* to terminate pending flushes */
 776         clear_bit(WDM_IN_USE, &desc->flags);
 777         spin_unlock_irqrestore(&desc->iuspin, flags);
 778         cancel_work_sync(&desc->rxwork);
 779         kill_urbs(desc);
 780         wake_up_all(&desc->wait);
 781         if (!desc->count)
 782                 cleanup(desc);
 783         mutex_unlock(&wdm_mutex);
 784 }
 785
 786 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
 787 {
 788         struct wdm_device *desc = usb_get_intfdata(intf);
 789         int rv = 0;
 790
 791         dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
 792
 793         mutex_lock(&desc->plock);
 794 #ifdef CONFIG_PM
 795         if ((message.event & PM_EVENT_AUTO) &&
 796                         test_bit(WDM_IN_USE, &desc->flags)) {
 797                 rv = -EBUSY;
 798         } else {
 799 #endif
 800                 cancel_work_sync(&desc->rxwork);
 801                 kill_urbs(desc);
 802 #ifdef CONFIG_PM
 803         }
 804 #endif
 805         mutex_unlock(&desc->plock);
 806
 807         return rv;
 808 }
 809
 810 static int recover_from_urb_loss(struct wdm_device *desc)
 811 {
 812         int rv = 0;
 813
 814         if (desc->count) {
 815                 rv = usb_submit_urb(desc->validity, GFP_NOIO);
 816                 if (rv < 0)
 817                         dev_err(&desc->intf->dev,
 818                                 "Error resume submitting int urb - %d\n", rv);
 819         }
 820         return rv;
 821 }
 822 static int wdm_resume(struct usb_interface *intf)
 823 {
 824         struct wdm_device *desc = usb_get_intfdata(intf);
 825         int rv;
 826
 827         dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
 828         mutex_lock(&desc->plock);
 829         rv = recover_from_urb_loss(desc);
 830         mutex_unlock(&desc->plock);
 831         return rv;
 832 }
 833
 834 static int wdm_pre_reset(struct usb_interface *intf)
 835 {
 836         struct wdm_device *desc = usb_get_intfdata(intf);
 837
 838         mutex_lock(&desc->plock);
 839         return 0;
 840 }
 841
 842 static int wdm_post_reset(struct usb_interface *intf)
 843 {
 844         struct wdm_device *desc = usb_get_intfdata(intf);
 845         int rv;
 846
 847         rv = recover_from_urb_loss(desc);
 848         mutex_unlock(&desc->plock);
 849         return 0;
 850 }
 851
 852 static struct usb_driver wdm_driver = {
 853         .name =         "cdc_wdm",
 854         .probe =        wdm_probe,
 855         .disconnect =   wdm_disconnect,
 856         .suspend =      wdm_suspend,
 857         .resume =       wdm_resume,
 858         .reset_resume = wdm_resume,
 859         .pre_reset =    wdm_pre_reset,
 860         .post_reset =   wdm_post_reset,
 861         .id_table =     wdm_ids,
 862         .supports_autosuspend = 1,
 863 };
 864
 865 /* --- low level module stuff --- */
 866
 867 static int __init wdm_init(void)
 868 {
 869         int rv;
 870
 871         rv = usb_register(&wdm_driver);
 872
 873         return rv;
 874 }
 875
 876 static void __exit wdm_exit(void)
 877 {
 878         usb_deregister(&wdm_driver);
 879 }
 880
 881 module_init(wdm_init);
 882 module_exit(wdm_exit);
 883
 884 MODULE_AUTHOR(DRIVER_AUTHOR);
 885 MODULE_DESCRIPTION(DRIVER_DESC);
 886 MODULE_LICENSE("GPL");