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 const 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 #define WDM_RESPONDING          7
  56 #define WDM_SUSPENDING          8
  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         __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            lock;
  91         wait_queue_head_t       wait;
  92         struct work_struct      rxwork;
  93         int                     werr;
  94         int                     rerr;
  95 };
  96
  97 static struct usb_driver wdm_driver;
  98
  99 /* --- callbacks --- */
 100 static void wdm_out_callback(struct urb *urb)
 101 {
 102         struct wdm_device *desc;
 103         desc = urb->context;
 104         spin_lock(&desc->iuspin);
 105         desc->werr = urb->status;
 106         spin_unlock(&desc->iuspin);
 107         clear_bit(WDM_IN_USE, &desc->flags);
 108         kfree(desc->outbuf);
 109         wake_up(&desc->wait);
 110 }
 111
 112 static void wdm_in_callback(struct urb *urb)
 113 {
 114         struct wdm_device *desc = urb->context;
 115         int status = urb->status;
 116
 117         spin_lock(&desc->iuspin);
 118         clear_bit(WDM_RESPONDING, &desc->flags);
 119
 120         if (status) {
 121                 switch (status) {
 122                 case -ENOENT:
 123                         dev_dbg(&desc->intf->dev,
 124                                 "nonzero urb status received: -ENOENT");
 125                         goto skip_error;
 126                 case -ECONNRESET:
 127                         dev_dbg(&desc->intf->dev,
 128                                 "nonzero urb status received: -ECONNRESET");
 129                         goto skip_error;
 130                 case -ESHUTDOWN:
 131                         dev_dbg(&desc->intf->dev,
 132                                 "nonzero urb status received: -ESHUTDOWN");
 133                         goto skip_error;
 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 skip_error:
 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_cdc_notification *dr;
 162
 163         desc = urb->context;
 164         dr = (struct usb_cdc_notification *)desc->sbuf;
 165
 166         if (status) {
 167                 switch (status) {
 168                 case -ESHUTDOWN:
 169                 case -ENOENT:
 170                 case -ECONNRESET:
 171                         return; /* unplug */
 172                 case -EPIPE:
 173                         set_bit(WDM_INT_STALL, &desc->flags);
 174                         dev_err(&desc->intf->dev, "Stall on int endpoint\n");
 175                         goto sw; /* halt is cleared in work */
 176                 default:
 177                         dev_err(&desc->intf->dev,
 178                                 "nonzero urb status received: %d\n", status);
 179                         break;
 180                 }
 181         }
 182
 183         if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
 184                 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
 185                         urb->actual_length);
 186                 goto exit;
 187         }
 188
 189         switch (dr->bNotificationType) {
 190         case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
 191                 dev_dbg(&desc->intf->dev,
 192                         "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
 193                         dr->wIndex, dr->wLength);
 194                 break;
 195
 196         case USB_CDC_NOTIFY_NETWORK_CONNECTION:
 197
 198                 dev_dbg(&desc->intf->dev,
 199                         "NOTIFY_NETWORK_CONNECTION %s network",
 200                         dr->wValue ? "connected to" : "disconnected from");
 201                 goto exit;
 202         default:
 203                 clear_bit(WDM_POLL_RUNNING, &desc->flags);
 204                 dev_err(&desc->intf->dev,
 205                         "unknown notification %d received: index %d len %d\n",
 206                         dr->bNotificationType, dr->wIndex, dr->wLength);
 207                 goto exit;
 208         }
 209
 210         spin_lock(&desc->iuspin);
 211         clear_bit(WDM_READ, &desc->flags);
 212         set_bit(WDM_RESPONDING, &desc->flags);
 213         if (!test_bit(WDM_DISCONNECTING, &desc->flags)
 214                 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
 215                 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
 216                 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
 217                         __func__, rv);
 218         }
 219         spin_unlock(&desc->iuspin);
 220         if (rv < 0) {
 221                 clear_bit(WDM_RESPONDING, &desc->flags);
 222                 if (rv == -EPERM)
 223                         return;
 224                 if (rv == -ENOMEM) {
 225 sw:
 226                         rv = schedule_work(&desc->rxwork);
 227                         if (rv)
 228                                 dev_err(&desc->intf->dev,
 229                                         "Cannot schedule work\n");
 230                 }
 231         }
 232 exit:
 233         rv = usb_submit_urb(urb, GFP_ATOMIC);
 234         if (rv)
 235                 dev_err(&desc->intf->dev,
 236                         "%s - usb_submit_urb failed with result %d\n",
 237                         __func__, rv);
 238
 239 }
 240
 241 static void kill_urbs(struct wdm_device *desc)
 242 {
 243         /* the order here is essential */
 244         usb_kill_urb(desc->command);
 245         usb_kill_urb(desc->validity);
 246         usb_kill_urb(desc->response);
 247 }
 248
 249 static void free_urbs(struct wdm_device *desc)
 250 {
 251         usb_free_urb(desc->validity);
 252         usb_free_urb(desc->response);
 253         usb_free_urb(desc->command);
 254 }
 255
 256 static void cleanup(struct wdm_device *desc)
 257 {
 258         kfree(desc->sbuf);
 259         kfree(desc->inbuf);
 260         kfree(desc->orq);
 261         kfree(desc->irq);
 262         kfree(desc->ubuf);
 263         free_urbs(desc);
 264         kfree(desc);
 265 }
 266
 267 static ssize_t wdm_write
 268 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 269 {
 270         u8 *buf;
 271         int rv = -EMSGSIZE, r, we;
 272         struct wdm_device *desc = file->private_data;
 273         struct usb_ctrlrequest *req;
 274
 275         if (count > desc->wMaxCommand)
 276                 count = desc->wMaxCommand;
 277
 278         spin_lock_irq(&desc->iuspin);
 279         we = desc->werr;
 280         desc->werr = 0;
 281         spin_unlock_irq(&desc->iuspin);
 282         if (we < 0)
 283                 return -EIO;
 284
 285         desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
 286         if (!buf) {
 287                 rv = -ENOMEM;
 288                 goto outnl;
 289         }
 290
 291         r = copy_from_user(buf, buffer, count);
 292         if (r > 0) {
 293                 kfree(buf);
 294                 rv = -EFAULT;
 295                 goto outnl;
 296         }
 297
 298         /* concurrent writes and disconnect */
 299         r = mutex_lock_interruptible(&desc->lock);
 300         rv = -ERESTARTSYS;
 301         if (r) {
 302                 kfree(buf);
 303                 goto outnl;
 304         }
 305
 306         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 307                 kfree(buf);
 308                 rv = -ENODEV;
 309                 goto outnp;
 310         }
 311
 312         r = usb_autopm_get_interface(desc->intf);
 313         if (r < 0) {
 314                 kfree(buf);
 315                 goto outnp;
 316         }
 317
 318         if (!(file->f_flags & O_NONBLOCK))
 319                 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
 320                                                                 &desc->flags));
 321         else
 322                 if (test_bit(WDM_IN_USE, &desc->flags))
 323                         r = -EAGAIN;
 324         if (r < 0) {
 325                 kfree(buf);
 326                 goto out;
 327         }
 328
 329         req = desc->orq;
 330         usb_fill_control_urb(
 331                 desc->command,
 332                 interface_to_usbdev(desc->intf),
 333                 /* using common endpoint 0 */
 334                 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
 335                 (unsigned char *)req,
 336                 buf,
 337                 count,
 338                 wdm_out_callback,
 339                 desc
 340         );
 341
 342         req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
 343                              USB_RECIP_INTERFACE);
 344         req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
 345         req->wValue = 0;
 346         req->wIndex = desc->inum;
 347         req->wLength = cpu_to_le16(count);
 348         set_bit(WDM_IN_USE, &desc->flags);
 349
 350         rv = usb_submit_urb(desc->command, GFP_KERNEL);
 351         if (rv < 0) {
 352                 kfree(buf);
 353                 clear_bit(WDM_IN_USE, &desc->flags);
 354                 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
 355         } else {
 356                 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
 357                         req->wIndex);
 358         }
 359 out:
 360         usb_autopm_put_interface(desc->intf);
 361 outnp:
 362         mutex_unlock(&desc->lock);
 363 outnl:
 364         return rv < 0 ? rv : count;
 365 }
 366
 367 static ssize_t wdm_read
 368 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 369 {
 370         int rv, cntr = 0;
 371         int i = 0;
 372         struct wdm_device *desc = file->private_data;
 373
 374
 375         rv = mutex_lock_interruptible(&desc->lock); /*concurrent reads */
 376         if (rv < 0)
 377                 return -ERESTARTSYS;
 378
 379         if (desc->length == 0) {
 380                 desc->read = 0;
 381 retry:
 382                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 383                         rv = -ENODEV;
 384                         goto err;
 385                 }
 386                 i++;
 387                 if (file->f_flags & O_NONBLOCK) {
 388                         if (!test_bit(WDM_READ, &desc->flags)) {
 389                                 rv = cntr ? cntr : -EAGAIN;
 390                                 goto err;
 391                         }
 392                         rv = 0;
 393                 } else {
 394                         rv = wait_event_interruptible(desc->wait,
 395                                 test_bit(WDM_READ, &desc->flags));
 396                 }
 397
 398                 /* may have happened while we slept */
 399                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 400                         rv = -ENODEV;
 401                         goto err;
 402                 }
 403                 usb_mark_last_busy(interface_to_usbdev(desc->intf));
 404                 if (rv < 0) {
 405                         rv = -ERESTARTSYS;
 406                         goto err;
 407                 }
 408
 409                 spin_lock_irq(&desc->iuspin);
 410
 411                 if (desc->rerr) { /* read completed, error happened */
 412                         desc->rerr = 0;
 413                         spin_unlock_irq(&desc->iuspin);
 414                         rv = -EIO;
 415                         goto err;
 416                 }
 417                 /*
 418                  * recheck whether we've lost the race
 419                  * against the completion handler
 420                  */
 421                 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
 422                         spin_unlock_irq(&desc->iuspin);
 423                         goto retry;
 424                 }
 425                 if (!desc->reslength) { /* zero length read */
 426                         spin_unlock_irq(&desc->iuspin);
 427                         goto retry;
 428                 }
 429                 clear_bit(WDM_READ, &desc->flags);
 430                 spin_unlock_irq(&desc->iuspin);
 431         }
 432
 433         cntr = count > desc->length ? desc->length : count;
 434         rv = copy_to_user(buffer, desc->ubuf, cntr);
 435         if (rv > 0) {
 436                 rv = -EFAULT;
 437                 goto err;
 438         }
 439
 440         for (i = 0; i < desc->length - cntr; i++)
 441                 desc->ubuf[i] = desc->ubuf[i + cntr];
 442
 443         desc->length -= cntr;
 444         /* in case we had outstanding data */
 445         if (!desc->length)
 446                 clear_bit(WDM_READ, &desc->flags);
 447         rv = cntr;
 448
 449 err:
 450         mutex_unlock(&desc->lock);
 451         return rv;
 452 }
 453
 454 static int wdm_flush(struct file *file, fl_owner_t id)
 455 {
 456         struct wdm_device *desc = file->private_data;
 457
 458         wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
 459         if (desc->werr < 0)
 460                 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
 461                         desc->werr);
 462
 463         return desc->werr;
 464 }
 465
 466 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
 467 {
 468         struct wdm_device *desc = file->private_data;
 469         unsigned long flags;
 470         unsigned int mask = 0;
 471
 472         spin_lock_irqsave(&desc->iuspin, flags);
 473         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 474                 mask = POLLERR;
 475                 spin_unlock_irqrestore(&desc->iuspin, flags);
 476                 goto desc_out;
 477         }
 478         if (test_bit(WDM_READ, &desc->flags))
 479                 mask = POLLIN | POLLRDNORM;
 480         if (desc->rerr || desc->werr)
 481                 mask |= POLLERR;
 482         if (!test_bit(WDM_IN_USE, &desc->flags))
 483                 mask |= POLLOUT | POLLWRNORM;
 484         spin_unlock_irqrestore(&desc->iuspin, flags);
 485
 486         poll_wait(file, &desc->wait, wait);
 487
 488 desc_out:
 489         return mask;
 490 }
 491
 492 static int wdm_open(struct inode *inode, struct file *file)
 493 {
 494         int minor = iminor(inode);
 495         int rv = -ENODEV;
 496         struct usb_interface *intf;
 497         struct wdm_device *desc;
 498
 499         mutex_lock(&wdm_mutex);
 500         intf = usb_find_interface(&wdm_driver, minor);
 501         if (!intf)
 502                 goto out;
 503
 504         desc = usb_get_intfdata(intf);
 505         if (test_bit(WDM_DISCONNECTING, &desc->flags))
 506                 goto out;
 507         file->private_data = desc;
 508
 509         rv = usb_autopm_get_interface(desc->intf);
 510         if (rv < 0) {
 511                 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
 512                 goto out;
 513         }
 514         intf->needs_remote_wakeup = 1;
 515
 516         mutex_lock(&desc->lock);
 517         if (!desc->count++) {
 518                 desc->werr = 0;
 519                 desc->rerr = 0;
 520                 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
 521                 if (rv < 0) {
 522                         desc->count--;
 523                         dev_err(&desc->intf->dev,
 524                                 "Error submitting int urb - %d\n", rv);
 525                 }
 526         } else {
 527                 rv = 0;
 528         }
 529         mutex_unlock(&desc->lock);
 530         usb_autopm_put_interface(desc->intf);
 531 out:
 532         mutex_unlock(&wdm_mutex);
 533         return rv;
 534 }
 535
 536 static int wdm_release(struct inode *inode, struct file *file)
 537 {
 538         struct wdm_device *desc = file->private_data;
 539
 540         mutex_lock(&wdm_mutex);
 541         mutex_lock(&desc->lock);
 542         desc->count--;
 543         mutex_unlock(&desc->lock);
 544
 545         if (!desc->count) {
 546                 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
 547                 kill_urbs(desc);
 548                 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 549                         desc->intf->needs_remote_wakeup = 0;
 550         }
 551         mutex_unlock(&wdm_mutex);
 552         return 0;
 553 }
 554
 555 static const struct file_operations wdm_fops = {
 556         .owner =        THIS_MODULE,
 557         .read =         wdm_read,
 558         .write =        wdm_write,
 559         .open =         wdm_open,
 560         .flush =        wdm_flush,
 561         .release =      wdm_release,
 562         .poll =         wdm_poll,
 563         .llseek =       noop_llseek,
 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 wdm_device *desc;
 600         struct usb_host_interface *iface;
 601         struct usb_endpoint_descriptor *ep;
 602         struct usb_cdc_dmm_desc *dmhd;
 603         u8 *buffer = intf->altsetting->extra;
 604         int buflen = intf->altsetting->extralen;
 605         u16 maxcom = 0;
 606
 607         if (!buffer)
 608                 goto out;
 609
 610         while (buflen > 2) {
 611                 if (buffer [1] != USB_DT_CS_INTERFACE) {
 612                         dev_err(&intf->dev, "skipping garbage\n");
 613                         goto next_desc;
 614                 }
 615
 616                 switch (buffer [2]) {
 617                 case USB_CDC_HEADER_TYPE:
 618                         break;
 619                 case USB_CDC_DMM_TYPE:
 620                         dmhd = (struct usb_cdc_dmm_desc *)buffer;
 621                         maxcom = le16_to_cpu(dmhd->wMaxCommand);
 622                         dev_dbg(&intf->dev,
 623                                 "Finding maximum buffer length: %d", maxcom);
 624                         break;
 625                 default:
 626                         dev_err(&intf->dev,
 627                                 "Ignoring extra header, type %d, length %d\n",
 628                                 buffer[2], buffer[0]);
 629                         break;
 630                 }
 631 next_desc:
 632                 buflen -= buffer[0];
 633                 buffer += buffer[0];
 634         }
 635
 636         rv = -ENOMEM;
 637         desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
 638         if (!desc)
 639                 goto out;
 640         mutex_init(&desc->lock);
 641         spin_lock_init(&desc->iuspin);
 642         init_waitqueue_head(&desc->wait);
 643         desc->wMaxCommand = maxcom;
 644         /* this will be expanded and needed in hardware endianness */
 645         desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
 646         desc->intf = intf;
 647         INIT_WORK(&desc->rxwork, wdm_rxwork);
 648
 649         rv = -EINVAL;
 650         iface = intf->cur_altsetting;
 651         if (iface->desc.bNumEndpoints != 1)
 652                 goto err;
 653         ep = &iface->endpoint[0].desc;
 654         if (!ep || !usb_endpoint_is_int_in(ep))
 655                 goto err;
 656
 657         desc->wMaxPacketSize = usb_endpoint_maxp(ep);
 658
 659         desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 660         if (!desc->orq)
 661                 goto err;
 662         desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 663         if (!desc->irq)
 664                 goto err;
 665
 666         desc->validity = usb_alloc_urb(0, GFP_KERNEL);
 667         if (!desc->validity)
 668                 goto err;
 669
 670         desc->response = usb_alloc_urb(0, GFP_KERNEL);
 671         if (!desc->response)
 672                 goto err;
 673
 674         desc->command = usb_alloc_urb(0, GFP_KERNEL);
 675         if (!desc->command)
 676                 goto err;
 677
 678         desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
 679         if (!desc->ubuf)
 680                 goto err;
 681
 682         desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
 683         if (!desc->sbuf)
 684                 goto err;
 685
 686         desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
 687         if (!desc->inbuf)
 688                 goto err;
 689
 690         usb_fill_int_urb(
 691                 desc->validity,
 692                 interface_to_usbdev(intf),
 693                 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
 694                 desc->sbuf,
 695                 desc->wMaxPacketSize,
 696                 wdm_int_callback,
 697                 desc,
 698                 ep->bInterval
 699         );
 700
 701         desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
 702         desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
 703         desc->irq->wValue = 0;
 704         desc->irq->wIndex = desc->inum;
 705         desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
 706
 707         usb_fill_control_urb(
 708                 desc->response,
 709                 interface_to_usbdev(intf),
 710                 /* using common endpoint 0 */
 711                 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
 712                 (unsigned char *)desc->irq,
 713                 desc->inbuf,
 714                 desc->wMaxCommand,
 715                 wdm_in_callback,
 716                 desc
 717         );
 718
 719         usb_set_intfdata(intf, desc);
 720         rv = usb_register_dev(intf, &wdm_class);
 721         if (rv < 0)
 722                 goto err2;
 723         else
 724                 dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
 725                         intf->minor - WDM_MINOR_BASE);
 726 out:
 727         return rv;
 728 err2:
 729         usb_set_intfdata(intf, NULL);
 730 err:
 731         free_urbs(desc);
 732         kfree(desc->inbuf);
 733         kfree(desc->sbuf);
 734         kfree(desc->ubuf);
 735         kfree(desc->orq);
 736         kfree(desc->irq);
 737         kfree(desc);
 738         return rv;
 739 }
 740
 741 static void wdm_disconnect(struct usb_interface *intf)
 742 {
 743         struct wdm_device *desc;
 744         unsigned long flags;
 745
 746         usb_deregister_dev(intf, &wdm_class);
 747         mutex_lock(&wdm_mutex);
 748         desc = usb_get_intfdata(intf);
 749
 750         /* the spinlock makes sure no new urbs are generated in the callbacks */
 751         spin_lock_irqsave(&desc->iuspin, flags);
 752         set_bit(WDM_DISCONNECTING, &desc->flags);
 753         set_bit(WDM_READ, &desc->flags);
 754         /* to terminate pending flushes */
 755         clear_bit(WDM_IN_USE, &desc->flags);
 756         spin_unlock_irqrestore(&desc->iuspin, flags);
 757         mutex_lock(&desc->lock);
 758         kill_urbs(desc);
 759         cancel_work_sync(&desc->rxwork);
 760         mutex_unlock(&desc->lock);
 761         wake_up_all(&desc->wait);
 762         if (!desc->count)
 763                 cleanup(desc);
 764         mutex_unlock(&wdm_mutex);
 765 }
 766
 767 #ifdef CONFIG_PM
 768 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
 769 {
 770         struct wdm_device *desc = usb_get_intfdata(intf);
 771         int rv = 0;
 772
 773         dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
 774
 775         /* if this is an autosuspend the caller does the locking */
 776         if (!PMSG_IS_AUTO(message))
 777                 mutex_lock(&desc->lock);
 778         spin_lock_irq(&desc->iuspin);
 779
 780         if (PMSG_IS_AUTO(message) &&
 781                         (test_bit(WDM_IN_USE, &desc->flags)
 782                         || test_bit(WDM_RESPONDING, &desc->flags))) {
 783                 spin_unlock_irq(&desc->iuspin);
 784                 rv = -EBUSY;
 785         } else {
 786
 787                 set_bit(WDM_SUSPENDING, &desc->flags);
 788                 spin_unlock_irq(&desc->iuspin);
 789                 /* callback submits work - order is essential */
 790                 kill_urbs(desc);
 791                 cancel_work_sync(&desc->rxwork);
 792         }
 793         if (!PMSG_IS_AUTO(message))
 794                 mutex_unlock(&desc->lock);
 795
 796         return rv;
 797 }
 798 #endif
 799
 800 static int recover_from_urb_loss(struct wdm_device *desc)
 801 {
 802         int rv = 0;
 803
 804         if (desc->count) {
 805                 rv = usb_submit_urb(desc->validity, GFP_NOIO);
 806                 if (rv < 0)
 807                         dev_err(&desc->intf->dev,
 808                                 "Error resume submitting int urb - %d\n", rv);
 809         }
 810         return rv;
 811 }
 812
 813 #ifdef CONFIG_PM
 814 static int wdm_resume(struct usb_interface *intf)
 815 {
 816         struct wdm_device *desc = usb_get_intfdata(intf);
 817         int rv;
 818
 819         dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
 820
 821         clear_bit(WDM_SUSPENDING, &desc->flags);
 822         rv = recover_from_urb_loss(desc);
 823
 824         return rv;
 825 }
 826 #endif
 827
 828 static int wdm_pre_reset(struct usb_interface *intf)
 829 {
 830         struct wdm_device *desc = usb_get_intfdata(intf);
 831
 832         mutex_lock(&desc->lock);
 833         kill_urbs(desc);
 834
 835         /*
 836          * we notify everybody using poll of
 837          * an exceptional situation
 838          * must be done before recovery lest a spontaneous
 839          * message from the device is lost
 840          */
 841         spin_lock_irq(&desc->iuspin);
 842         desc->rerr = -EINTR;
 843         spin_unlock_irq(&desc->iuspin);
 844         wake_up_all(&desc->wait);
 845         return 0;
 846 }
 847
 848 static int wdm_post_reset(struct usb_interface *intf)
 849 {
 850         struct wdm_device *desc = usb_get_intfdata(intf);
 851         int rv;
 852
 853         rv = recover_from_urb_loss(desc);
 854         mutex_unlock(&desc->lock);
 855         return 0;
 856 }
 857
 858 static struct usb_driver wdm_driver = {
 859         .name =         "cdc_wdm",
 860         .probe =        wdm_probe,
 861         .disconnect =   wdm_disconnect,
 862 #ifdef CONFIG_PM
 863         .suspend =      wdm_suspend,
 864         .resume =       wdm_resume,
 865         .reset_resume = wdm_resume,
 866 #endif
 867         .pre_reset =    wdm_pre_reset,
 868         .post_reset =   wdm_post_reset,
 869         .id_table =     wdm_ids,
 870         .supports_autosuspend = 1,
 871 };
 872
 873 module_usb_driver(wdm_driver);
 874
 875 MODULE_AUTHOR(DRIVER_AUTHOR);
 876 MODULE_DESCRIPTION(DRIVER_DESC);
 877 MODULE_LICENSE("GPL");