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