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