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         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            lock;
  92         wait_queue_head_t       wait;
  93         struct work_struct      rxwork;
  94         int                     werr;
  95         int                     rerr;
  96 };
  97
  98 static struct usb_driver wdm_driver;
  99
 100 /* --- callbacks --- */
 101 static void wdm_out_callback(struct urb *urb)
 102 {
 103         struct wdm_device *desc;
 104         desc = urb->context;
 105         spin_lock(&desc->iuspin);
 106         desc->werr = urb->status;
 107         spin_unlock(&desc->iuspin);
 108         clear_bit(WDM_IN_USE, &desc->flags);
 109         kfree(desc->outbuf);
 110         wake_up(&desc->wait);
 111 }
 112
 113 static void wdm_in_callback(struct urb *urb)
 114 {
 115         struct wdm_device *desc = urb->context;
 116         int status = urb->status;
 117
 118         spin_lock(&desc->iuspin);
 119         clear_bit(WDM_RESPONDING, &desc->flags);
 120
 121         if (status) {
 122                 switch (status) {
 123                 case -ENOENT:
 124                         dev_dbg(&desc->intf->dev,
 125                                 "nonzero urb status received: -ENOENT");
 126                         goto skip_error;
 127                 case -ECONNRESET:
 128                         dev_dbg(&desc->intf->dev,
 129                                 "nonzero urb status received: -ECONNRESET");
 130                         goto skip_error;
 131                 case -ESHUTDOWN:
 132                         dev_dbg(&desc->intf->dev,
 133                                 "nonzero urb status received: -ESHUTDOWN");
 134                         goto skip_error;
 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 skip_error:
 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         set_bit(WDM_RESPONDING, &desc->flags);
 234         if (!test_bit(WDM_DISCONNECTING, &desc->flags)
 235                 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
 236                 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
 237                 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
 238                         __func__, rv);
 239         }
 240         spin_unlock(&desc->iuspin);
 241         if (rv < 0) {
 242                 clear_bit(WDM_RESPONDING, &desc->flags);
 243                 if (rv == -EPERM)
 244                         return;
 245                 if (rv == -ENOMEM) {
 246 sw:
 247                         rv = schedule_work(&desc->rxwork);
 248                         if (rv)
 249                                 dev_err(&desc->intf->dev,
 250                                         "Cannot schedule work\n");
 251                 }
 252         }
 253 exit:
 254         rv = usb_submit_urb(urb, GFP_ATOMIC);
 255         if (rv)
 256                 dev_err(&desc->intf->dev,
 257                         "%s - usb_submit_urb failed with result %d\n",
 258                         __func__, rv);
 259
 260 }
 261
 262 static void kill_urbs(struct wdm_device *desc)
 263 {
 264         /* the order here is essential */
 265         usb_kill_urb(desc->command);
 266         usb_kill_urb(desc->validity);
 267         usb_kill_urb(desc->response);
 268 }
 269
 270 static void free_urbs(struct wdm_device *desc)
 271 {
 272         usb_free_urb(desc->validity);
 273         usb_free_urb(desc->response);
 274         usb_free_urb(desc->command);
 275 }
 276
 277 static void cleanup(struct wdm_device *desc)
 278 {
 279         usb_buffer_free(interface_to_usbdev(desc->intf),
 280                         desc->wMaxPacketSize,
 281                         desc->sbuf,
 282                         desc->validity->transfer_dma);
 283         usb_buffer_free(interface_to_usbdev(desc->intf),
 284                         desc->wMaxCommand,
 285                         desc->inbuf,
 286                         desc->response->transfer_dma);
 287         kfree(desc->orq);
 288         kfree(desc->irq);
 289         kfree(desc->ubuf);
 290         free_urbs(desc);
 291         kfree(desc);
 292 }
 293
 294 static ssize_t wdm_write
 295 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 296 {
 297         u8 *buf;
 298         int rv = -EMSGSIZE, r, we;
 299         struct wdm_device *desc = file->private_data;
 300         struct usb_ctrlrequest *req;
 301
 302         if (count > desc->wMaxCommand)
 303                 count = desc->wMaxCommand;
 304
 305         spin_lock_irq(&desc->iuspin);
 306         we = desc->werr;
 307         desc->werr = 0;
 308         spin_unlock_irq(&desc->iuspin);
 309         if (we < 0)
 310                 return -EIO;
 311
 312         desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
 313         if (!buf) {
 314                 rv = -ENOMEM;
 315                 goto outnl;
 316         }
 317
 318         r = copy_from_user(buf, buffer, count);
 319         if (r > 0) {
 320                 kfree(buf);
 321                 rv = -EFAULT;
 322                 goto outnl;
 323         }
 324
 325         /* concurrent writes and disconnect */
 326         r = mutex_lock_interruptible(&desc->lock);
 327         rv = -ERESTARTSYS;
 328         if (r) {
 329                 kfree(buf);
 330                 goto outnl;
 331         }
 332
 333         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 334                 kfree(buf);
 335                 rv = -ENODEV;
 336                 goto outnp;
 337         }
 338
 339         r = usb_autopm_get_interface(desc->intf);
 340         if (r < 0) {
 341                 kfree(buf);
 342                 goto outnp;
 343         }
 344
 345         if (!file->f_flags && O_NONBLOCK)
 346                 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
 347                                                                 &desc->flags));
 348         else
 349                 if (test_bit(WDM_IN_USE, &desc->flags))
 350                         r = -EAGAIN;
 351         if (r < 0) {
 352                 kfree(buf);
 353                 goto out;
 354         }
 355
 356         req = desc->orq;
 357         usb_fill_control_urb(
 358                 desc->command,
 359                 interface_to_usbdev(desc->intf),
 360                 /* using common endpoint 0 */
 361                 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
 362                 (unsigned char *)req,
 363                 buf,
 364                 count,
 365                 wdm_out_callback,
 366                 desc
 367         );
 368
 369         req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
 370                              USB_RECIP_INTERFACE);
 371         req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
 372         req->wValue = 0;
 373         req->wIndex = desc->inum;
 374         req->wLength = cpu_to_le16(count);
 375         set_bit(WDM_IN_USE, &desc->flags);
 376
 377         rv = usb_submit_urb(desc->command, GFP_KERNEL);
 378         if (rv < 0) {
 379                 kfree(buf);
 380                 clear_bit(WDM_IN_USE, &desc->flags);
 381                 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
 382         } else {
 383                 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
 384                         req->wIndex);
 385         }
 386 out:
 387         usb_autopm_put_interface(desc->intf);
 388 outnp:
 389         mutex_unlock(&desc->lock);
 390 outnl:
 391         return rv < 0 ? rv : count;
 392 }
 393
 394 static ssize_t wdm_read
 395 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 396 {
 397         int rv, cntr = 0;
 398         int i = 0;
 399         struct wdm_device *desc = file->private_data;
 400
 401
 402         rv = mutex_lock_interruptible(&desc->lock); /*concurrent reads */
 403         if (rv < 0)
 404                 return -ERESTARTSYS;
 405
 406         if (desc->length == 0) {
 407                 desc->read = 0;
 408 retry:
 409                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 410                         rv = -ENODEV;
 411                         goto err;
 412                 }
 413                 i++;
 414                 if (file->f_flags & O_NONBLOCK) {
 415                         if (!test_bit(WDM_READ, &desc->flags)) {
 416                                 rv = cntr ? cntr : -EAGAIN;
 417                                 goto err;
 418                         }
 419                         rv = 0;
 420                 } else {
 421                         rv = wait_event_interruptible(desc->wait,
 422                                 test_bit(WDM_READ, &desc->flags));
 423                 }
 424
 425                 /* may have happened while we slept */
 426                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 427                         rv = -ENODEV;
 428                         goto err;
 429                 }
 430                 usb_mark_last_busy(interface_to_usbdev(desc->intf));
 431                 if (rv < 0) {
 432                         rv = -ERESTARTSYS;
 433                         goto err;
 434                 }
 435
 436                 spin_lock_irq(&desc->iuspin);
 437
 438                 if (desc->rerr) { /* read completed, error happened */
 439                         desc->rerr = 0;
 440                         spin_unlock_irq(&desc->iuspin);
 441                         rv = -EIO;
 442                         goto err;
 443                 }
 444                 /*
 445                  * recheck whether we've lost the race
 446                  * against the completion handler
 447                  */
 448                 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
 449                         spin_unlock_irq(&desc->iuspin);
 450                         goto retry;
 451                 }
 452                 if (!desc->reslength) { /* zero length read */
 453                         spin_unlock_irq(&desc->iuspin);
 454                         goto retry;
 455                 }
 456                 clear_bit(WDM_READ, &desc->flags);
 457                 spin_unlock_irq(&desc->iuspin);
 458         }
 459
 460         cntr = count > desc->length ? desc->length : count;
 461         rv = copy_to_user(buffer, desc->ubuf, cntr);
 462         if (rv > 0) {
 463                 rv = -EFAULT;
 464                 goto err;
 465         }
 466
 467         for (i = 0; i < desc->length - cntr; i++)
 468                 desc->ubuf[i] = desc->ubuf[i + cntr];
 469
 470         desc->length -= cntr;
 471         /* in case we had outstanding data */
 472         if (!desc->length)
 473                 clear_bit(WDM_READ, &desc->flags);
 474         rv = cntr;
 475
 476 err:
 477         mutex_unlock(&desc->lock);
 478         return rv;
 479 }
 480
 481 static int wdm_flush(struct file *file, fl_owner_t id)
 482 {
 483         struct wdm_device *desc = file->private_data;
 484
 485         wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
 486         if (desc->werr < 0)
 487                 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
 488                         desc->werr);
 489
 490         return desc->werr;
 491 }
 492
 493 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
 494 {
 495         struct wdm_device *desc = file->private_data;
 496         unsigned long flags;
 497         unsigned int mask = 0;
 498
 499         spin_lock_irqsave(&desc->iuspin, flags);
 500         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 501                 mask = POLLERR;
 502                 spin_unlock_irqrestore(&desc->iuspin, flags);
 503                 goto desc_out;
 504         }
 505         if (test_bit(WDM_READ, &desc->flags))
 506                 mask = POLLIN | POLLRDNORM;
 507         if (desc->rerr || desc->werr)
 508                 mask |= POLLERR;
 509         if (!test_bit(WDM_IN_USE, &desc->flags))
 510                 mask |= POLLOUT | POLLWRNORM;
 511         spin_unlock_irqrestore(&desc->iuspin, flags);
 512
 513         poll_wait(file, &desc->wait, wait);
 514
 515 desc_out:
 516         return mask;
 517 }
 518
 519 static int wdm_open(struct inode *inode, struct file *file)
 520 {
 521         int minor = iminor(inode);
 522         int rv = -ENODEV;
 523         struct usb_interface *intf;
 524         struct wdm_device *desc;
 525
 526         mutex_lock(&wdm_mutex);
 527         intf = usb_find_interface(&wdm_driver, minor);
 528         if (!intf)
 529                 goto out;
 530
 531         desc = usb_get_intfdata(intf);
 532         if (test_bit(WDM_DISCONNECTING, &desc->flags))
 533                 goto out;
 534         file->private_data = desc;
 535
 536         rv = usb_autopm_get_interface(desc->intf);
 537         if (rv < 0) {
 538                 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
 539                 goto out;
 540         }
 541         intf->needs_remote_wakeup = 1;
 542
 543         mutex_lock(&desc->lock);
 544         if (!desc->count++) {
 545                 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
 546                 if (rv < 0) {
 547                         desc->count--;
 548                         dev_err(&desc->intf->dev,
 549                                 "Error submitting int urb - %d\n", rv);
 550                 }
 551         } else {
 552                 rv = 0;
 553         }
 554         mutex_unlock(&desc->lock);
 555         usb_autopm_put_interface(desc->intf);
 556 out:
 557         mutex_unlock(&wdm_mutex);
 558         return rv;
 559 }
 560
 561 static int wdm_release(struct inode *inode, struct file *file)
 562 {
 563         struct wdm_device *desc = file->private_data;
 564
 565         mutex_lock(&wdm_mutex);
 566         mutex_lock(&desc->lock);
 567         desc->count--;
 568         mutex_unlock(&desc->lock);
 569
 570         if (!desc->count) {
 571                 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
 572                 kill_urbs(desc);
 573                 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 574                         desc->intf->needs_remote_wakeup = 0;
 575         }
 576         mutex_unlock(&wdm_mutex);
 577         return 0;
 578 }
 579
 580 static const struct file_operations wdm_fops = {
 581         .owner =        THIS_MODULE,
 582         .read =         wdm_read,
 583         .write =        wdm_write,
 584         .open =         wdm_open,
 585         .flush =        wdm_flush,
 586         .release =      wdm_release,
 587         .poll =         wdm_poll
 588 };
 589
 590 static struct usb_class_driver wdm_class = {
 591         .name =         "cdc-wdm%d",
 592         .fops =         &wdm_fops,
 593         .minor_base =   WDM_MINOR_BASE,
 594 };
 595
 596 /* --- error handling --- */
 597 static void wdm_rxwork(struct work_struct *work)
 598 {
 599         struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
 600         unsigned long flags;
 601         int rv;
 602
 603         spin_lock_irqsave(&desc->iuspin, flags);
 604         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 605                 spin_unlock_irqrestore(&desc->iuspin, flags);
 606         } else {
 607                 spin_unlock_irqrestore(&desc->iuspin, flags);
 608                 rv = usb_submit_urb(desc->response, GFP_KERNEL);
 609                 if (rv < 0 && rv != -EPERM) {
 610                         spin_lock_irqsave(&desc->iuspin, flags);
 611                         if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 612                                 schedule_work(&desc->rxwork);
 613                         spin_unlock_irqrestore(&desc->iuspin, flags);
 614                 }
 615         }
 616 }
 617
 618 /* --- hotplug --- */
 619
 620 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
 621 {
 622         int rv = -EINVAL;
 623         struct usb_device *udev = interface_to_usbdev(intf);
 624         struct wdm_device *desc;
 625         struct usb_host_interface *iface;
 626         struct usb_endpoint_descriptor *ep;
 627         struct usb_cdc_dmm_desc *dmhd;
 628         u8 *buffer = intf->altsetting->extra;
 629         int buflen = intf->altsetting->extralen;
 630         u16 maxcom = 0;
 631
 632         if (!buffer)
 633                 goto out;
 634
 635         while (buflen > 2) {
 636                 if (buffer [1] != USB_DT_CS_INTERFACE) {
 637                         dev_err(&intf->dev, "skipping garbage\n");
 638                         goto next_desc;
 639                 }
 640
 641                 switch (buffer [2]) {
 642                 case USB_CDC_HEADER_TYPE:
 643                         break;
 644                 case USB_CDC_DMM_TYPE:
 645                         dmhd = (struct usb_cdc_dmm_desc *)buffer;
 646                         maxcom = le16_to_cpu(dmhd->wMaxCommand);
 647                         dev_dbg(&intf->dev,
 648                                 "Finding maximum buffer length: %d", maxcom);
 649                         break;
 650                 default:
 651                         dev_err(&intf->dev,
 652                                 "Ignoring extra header, type %d, length %d\n",
 653                                 buffer[2], buffer[0]);
 654                         break;
 655                 }
 656 next_desc:
 657                 buflen -= buffer[0];
 658                 buffer += buffer[0];
 659         }
 660
 661         rv = -ENOMEM;
 662         desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
 663         if (!desc)
 664                 goto out;
 665         mutex_init(&desc->lock);
 666         spin_lock_init(&desc->iuspin);
 667         init_waitqueue_head(&desc->wait);
 668         desc->wMaxCommand = maxcom;
 669         /* this will be expanded and needed in hardware endianness */
 670         desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
 671         desc->intf = intf;
 672         INIT_WORK(&desc->rxwork, wdm_rxwork);
 673
 674         rv = -EINVAL;
 675         iface = intf->cur_altsetting;
 676         if (iface->desc.bNumEndpoints != 1)
 677                 goto err;
 678         ep = &iface->endpoint[0].desc;
 679         if (!ep || !usb_endpoint_is_int_in(ep))
 680                 goto err;
 681
 682         desc->wMaxPacketSize = le16_to_cpu(ep->wMaxPacketSize);
 683         desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0;
 684
 685         desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 686         if (!desc->orq)
 687                 goto err;
 688         desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 689         if (!desc->irq)
 690                 goto err;
 691
 692         desc->validity = usb_alloc_urb(0, GFP_KERNEL);
 693         if (!desc->validity)
 694                 goto err;
 695
 696         desc->response = usb_alloc_urb(0, GFP_KERNEL);
 697         if (!desc->response)
 698                 goto err;
 699
 700         desc->command = usb_alloc_urb(0, GFP_KERNEL);
 701         if (!desc->command)
 702                 goto err;
 703
 704         desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
 705         if (!desc->ubuf)
 706                 goto err;
 707
 708         desc->sbuf = usb_buffer_alloc(interface_to_usbdev(intf),
 709                                         desc->wMaxPacketSize,
 710                                         GFP_KERNEL,
 711                                         &desc->validity->transfer_dma);
 712         if (!desc->sbuf)
 713                 goto err;
 714
 715         desc->inbuf = usb_buffer_alloc(interface_to_usbdev(intf),
 716                                         desc->bMaxPacketSize0,
 717                                         GFP_KERNEL,
 718                                         &desc->response->transfer_dma);
 719         if (!desc->inbuf)
 720                 goto err2;
 721
 722         usb_fill_int_urb(
 723                 desc->validity,
 724                 interface_to_usbdev(intf),
 725                 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
 726                 desc->sbuf,
 727                 desc->wMaxPacketSize,
 728                 wdm_int_callback,
 729                 desc,
 730                 ep->bInterval
 731         );
 732         desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 733
 734         usb_set_intfdata(intf, desc);
 735         rv = usb_register_dev(intf, &wdm_class);
 736         if (rv < 0)
 737                 goto err3;
 738         else
 739                 dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
 740                         intf->minor - WDM_MINOR_BASE);
 741 out:
 742         return rv;
 743 err3:
 744         usb_set_intfdata(intf, NULL);
 745         usb_buffer_free(interface_to_usbdev(desc->intf),
 746                         desc->bMaxPacketSize0,
 747                         desc->inbuf,
 748                         desc->response->transfer_dma);
 749 err2:
 750         usb_buffer_free(interface_to_usbdev(desc->intf),
 751                         desc->wMaxPacketSize,
 752                         desc->sbuf,
 753                         desc->validity->transfer_dma);
 754 err:
 755         free_urbs(desc);
 756         kfree(desc->ubuf);
 757         kfree(desc->orq);
 758         kfree(desc->irq);
 759         kfree(desc);
 760         return rv;
 761 }
 762
 763 static void wdm_disconnect(struct usb_interface *intf)
 764 {
 765         struct wdm_device *desc;
 766         unsigned long flags;
 767
 768         usb_deregister_dev(intf, &wdm_class);
 769         mutex_lock(&wdm_mutex);
 770         desc = usb_get_intfdata(intf);
 771
 772         /* the spinlock makes sure no new urbs are generated in the callbacks */
 773         spin_lock_irqsave(&desc->iuspin, flags);
 774         set_bit(WDM_DISCONNECTING, &desc->flags);
 775         set_bit(WDM_READ, &desc->flags);
 776         /* to terminate pending flushes */
 777         clear_bit(WDM_IN_USE, &desc->flags);
 778         spin_unlock_irqrestore(&desc->iuspin, flags);
 779         mutex_lock(&desc->lock);
 780         kill_urbs(desc);
 781         cancel_work_sync(&desc->rxwork);
 782         mutex_unlock(&desc->lock);
 783         wake_up_all(&desc->wait);
 784         if (!desc->count)
 785                 cleanup(desc);
 786         mutex_unlock(&wdm_mutex);
 787 }
 788
 789 #ifdef CONFIG_PM
 790 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
 791 {
 792         struct wdm_device *desc = usb_get_intfdata(intf);
 793         int rv = 0;
 794
 795         dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
 796
 797         /* if this is an autosuspend the caller does the locking */
 798         if (!(message.event & PM_EVENT_AUTO))
 799                 mutex_lock(&desc->lock);
 800         spin_lock_irq(&desc->iuspin);
 801
 802         if ((message.event & PM_EVENT_AUTO) &&
 803                         (test_bit(WDM_IN_USE, &desc->flags)
 804                         || test_bit(WDM_RESPONDING, &desc->flags))) {
 805                 spin_unlock_irq(&desc->iuspin);
 806                 rv = -EBUSY;
 807         } else {
 808
 809                 set_bit(WDM_SUSPENDING, &desc->flags);
 810                 spin_unlock_irq(&desc->iuspin);
 811                 /* callback submits work - order is essential */
 812                 kill_urbs(desc);
 813                 cancel_work_sync(&desc->rxwork);
 814         }
 815         if (!(message.event & PM_EVENT_AUTO))
 816                 mutex_unlock(&desc->lock);
 817
 818         return rv;
 819 }
 820 #endif
 821
 822 static int recover_from_urb_loss(struct wdm_device *desc)
 823 {
 824         int rv = 0;
 825
 826         if (desc->count) {
 827                 rv = usb_submit_urb(desc->validity, GFP_NOIO);
 828                 if (rv < 0)
 829                         dev_err(&desc->intf->dev,
 830                                 "Error resume submitting int urb - %d\n", rv);
 831         }
 832         return rv;
 833 }
 834
 835 #ifdef CONFIG_PM
 836 static int wdm_resume(struct usb_interface *intf)
 837 {
 838         struct wdm_device *desc = usb_get_intfdata(intf);
 839         int rv;
 840
 841         dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
 842
 843         clear_bit(WDM_SUSPENDING, &desc->flags);
 844         rv = recover_from_urb_loss(desc);
 845
 846         return rv;
 847 }
 848 #endif
 849
 850 static int wdm_pre_reset(struct usb_interface *intf)
 851 {
 852         struct wdm_device *desc = usb_get_intfdata(intf);
 853
 854         mutex_lock(&desc->lock);
 855         return 0;
 856 }
 857
 858 static int wdm_post_reset(struct usb_interface *intf)
 859 {
 860         struct wdm_device *desc = usb_get_intfdata(intf);
 861         int rv;
 862
 863         rv = recover_from_urb_loss(desc);
 864         mutex_unlock(&desc->lock);
 865         return 0;
 866 }
 867
 868 static struct usb_driver wdm_driver = {
 869         .name =         "cdc_wdm",
 870         .probe =        wdm_probe,
 871         .disconnect =   wdm_disconnect,
 872 #ifdef CONFIG_PM
 873         .suspend =      wdm_suspend,
 874         .resume =       wdm_resume,
 875         .reset_resume = wdm_resume,
 876 #endif
 877         .pre_reset =    wdm_pre_reset,
 878         .post_reset =   wdm_post_reset,
 879         .id_table =     wdm_ids,
 880         .supports_autosuspend = 1,
 881 };
 882
 883 /* --- low level module stuff --- */
 884
 885 static int __init wdm_init(void)
 886 {
 887         int rv;
 888
 889         rv = usb_register(&wdm_driver);
 890
 891         return rv;
 892 }
 893
 894 static void __exit wdm_exit(void)
 895 {
 896         usb_deregister(&wdm_driver);
 897 }
 898
 899 module_init(wdm_init);
 900 module_exit(wdm_exit);
 901
 902 MODULE_AUTHOR(DRIVER_AUTHOR);
 903 MODULE_DESCRIPTION(DRIVER_DESC);
 904 MODULE_LICENSE("GPL");