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            wlock;
  92         struct mutex            rlock;
  93         wait_queue_head_t       wait;
  94         struct work_struct      rxwork;
  95         int                     werr;
  96         int                     rerr;
  97 };
  98
  99 static struct usb_driver wdm_driver;
 100
 101 /* --- callbacks --- */
 102 static void wdm_out_callback(struct urb *urb)
 103 {
 104         struct wdm_device *desc;
 105         desc = urb->context;
 106         spin_lock(&desc->iuspin);
 107         desc->werr = urb->status;
 108         spin_unlock(&desc->iuspin);
 109         clear_bit(WDM_IN_USE, &desc->flags);
 110         kfree(desc->outbuf);
 111         wake_up(&desc->wait);
 112 }
 113
 114 static void wdm_in_callback(struct urb *urb)
 115 {
 116         struct wdm_device *desc = urb->context;
 117         int status = urb->status;
 118
 119         spin_lock(&desc->iuspin);
 120         clear_bit(WDM_RESPONDING, &desc->flags);
 121
 122         if (status) {
 123                 switch (status) {
 124                 case -ENOENT:
 125                         dev_dbg(&desc->intf->dev,
 126                                 "nonzero urb status received: -ENOENT");
 127                         goto skip_error;
 128                 case -ECONNRESET:
 129                         dev_dbg(&desc->intf->dev,
 130                                 "nonzero urb status received: -ECONNRESET");
 131                         goto skip_error;
 132                 case -ESHUTDOWN:
 133                         dev_dbg(&desc->intf->dev,
 134                                 "nonzero urb status received: -ESHUTDOWN");
 135                         goto skip_error;
 136                 case -EPIPE:
 137                         dev_err(&desc->intf->dev,
 138                                 "nonzero urb status received: -EPIPE\n");
 139                         break;
 140                 default:
 141                         dev_err(&desc->intf->dev,
 142                                 "Unexpected error %d\n", status);
 143                         break;
 144                 }
 145         }
 146
 147         desc->rerr = status;
 148         desc->reslength = urb->actual_length;
 149         memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
 150         desc->length += desc->reslength;
 151 skip_error:
 152         wake_up(&desc->wait);
 153
 154         set_bit(WDM_READ, &desc->flags);
 155         spin_unlock(&desc->iuspin);
 156 }
 157
 158 static void wdm_int_callback(struct urb *urb)
 159 {
 160         int rv = 0;
 161         int status = urb->status;
 162         struct wdm_device *desc;
 163         struct usb_ctrlrequest *req;
 164         struct usb_cdc_notification *dr;
 165
 166         desc = urb->context;
 167         req = desc->irq;
 168         dr = (struct usb_cdc_notification *)desc->sbuf;
 169
 170         if (status) {
 171                 switch (status) {
 172                 case -ESHUTDOWN:
 173                 case -ENOENT:
 174                 case -ECONNRESET:
 175                         return; /* unplug */
 176                 case -EPIPE:
 177                         set_bit(WDM_INT_STALL, &desc->flags);
 178                         dev_err(&desc->intf->dev, "Stall on int endpoint\n");
 179                         goto sw; /* halt is cleared in work */
 180                 default:
 181                         dev_err(&desc->intf->dev,
 182                                 "nonzero urb status received: %d\n", status);
 183                         break;
 184                 }
 185         }
 186
 187         if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
 188                 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
 189                         urb->actual_length);
 190                 goto exit;
 191         }
 192
 193         switch (dr->bNotificationType) {
 194         case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
 195                 dev_dbg(&desc->intf->dev,
 196                         "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
 197                         dr->wIndex, dr->wLength);
 198                 break;
 199
 200         case USB_CDC_NOTIFY_NETWORK_CONNECTION:
 201
 202                 dev_dbg(&desc->intf->dev,
 203                         "NOTIFY_NETWORK_CONNECTION %s network",
 204                         dr->wValue ? "connected to" : "disconnected from");
 205                 goto exit;
 206         default:
 207                 clear_bit(WDM_POLL_RUNNING, &desc->flags);
 208                 dev_err(&desc->intf->dev,
 209                         "unknown notification %d received: index %d len %d\n",
 210                         dr->bNotificationType, dr->wIndex, dr->wLength);
 211                 goto exit;
 212         }
 213
 214         req->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
 215         req->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
 216         req->wValue = 0;
 217         req->wIndex = desc->inum;
 218         req->wLength = cpu_to_le16(desc->wMaxCommand);
 219
 220         usb_fill_control_urb(
 221                 desc->response,
 222                 interface_to_usbdev(desc->intf),
 223                 /* using common endpoint 0 */
 224                 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
 225                 (unsigned char *)req,
 226                 desc->inbuf,
 227                 desc->wMaxCommand,
 228                 wdm_in_callback,
 229                 desc
 230         );
 231         desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 232         spin_lock(&desc->iuspin);
 233         clear_bit(WDM_READ, &desc->flags);
 234         set_bit(WDM_RESPONDING, &desc->flags);
 235         if (!test_bit(WDM_DISCONNECTING, &desc->flags)
 236                 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
 237                 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
 238                 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
 239                         __func__, rv);
 240         }
 241         spin_unlock(&desc->iuspin);
 242         if (rv < 0) {
 243                 clear_bit(WDM_RESPONDING, &desc->flags);
 244                 if (rv == -EPERM)
 245                         return;
 246                 if (rv == -ENOMEM) {
 247 sw:
 248                         rv = schedule_work(&desc->rxwork);
 249                         if (rv)
 250                                 dev_err(&desc->intf->dev,
 251                                         "Cannot schedule work\n");
 252                 }
 253         }
 254 exit:
 255         rv = usb_submit_urb(urb, GFP_ATOMIC);
 256         if (rv)
 257                 dev_err(&desc->intf->dev,
 258                         "%s - usb_submit_urb failed with result %d\n",
 259                         __func__, rv);
 260
 261 }
 262
 263 static void kill_urbs(struct wdm_device *desc)
 264 {
 265         /* the order here is essential */
 266         usb_kill_urb(desc->command);
 267         usb_kill_urb(desc->validity);
 268         usb_kill_urb(desc->response);
 269 }
 270
 271 static void free_urbs(struct wdm_device *desc)
 272 {
 273         usb_free_urb(desc->validity);
 274         usb_free_urb(desc->response);
 275         usb_free_urb(desc->command);
 276 }
 277
 278 static void cleanup(struct wdm_device *desc)
 279 {
 280         usb_free_coherent(interface_to_usbdev(desc->intf),
 281                           desc->wMaxPacketSize,
 282                           desc->sbuf,
 283                           desc->validity->transfer_dma);
 284         usb_free_coherent(interface_to_usbdev(desc->intf),
 285                           desc->bMaxPacketSize0,
 286                           desc->inbuf,
 287                           desc->response->transfer_dma);
 288         kfree(desc->orq);
 289         kfree(desc->irq);
 290         kfree(desc->ubuf);
 291         free_urbs(desc);
 292         kfree(desc);
 293 }
 294
 295 static ssize_t wdm_write
 296 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 297 {
 298         u8 *buf;
 299         int rv = -EMSGSIZE, r, we;
 300         struct wdm_device *desc = file->private_data;
 301         struct usb_ctrlrequest *req;
 302
 303         if (count > desc->wMaxCommand)
 304                 count = desc->wMaxCommand;
 305
 306         spin_lock_irq(&desc->iuspin);
 307         we = desc->werr;
 308         desc->werr = 0;
 309         spin_unlock_irq(&desc->iuspin);
 310         if (we < 0)
 311                 return -EIO;
 312
 313         desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
 314         if (!buf) {
 315                 rv = -ENOMEM;
 316                 goto outnl;
 317         }
 318
 319         r = copy_from_user(buf, buffer, count);
 320         if (r > 0) {
 321                 kfree(buf);
 322                 rv = -EFAULT;
 323                 goto outnl;
 324         }
 325
 326         /* concurrent writes and disconnect */
 327         r = mutex_lock_interruptible(&desc->wlock);
 328         rv = -ERESTARTSYS;
 329         if (r) {
 330                 kfree(buf);
 331                 goto outnl;
 332         }
 333
 334         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 335                 kfree(buf);
 336                 rv = -ENODEV;
 337                 goto outnp;
 338         }
 339
 340         r = usb_autopm_get_interface(desc->intf);
 341         if (r < 0) {
 342                 kfree(buf);
 343                 goto outnp;
 344         }
 345
 346         if (!(file->f_flags & O_NONBLOCK))
 347                 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
 348                                                                 &desc->flags));
 349         else
 350                 if (test_bit(WDM_IN_USE, &desc->flags))
 351                         r = -EAGAIN;
 352         if (r < 0) {
 353                 kfree(buf);
 354                 goto out;
 355         }
 356
 357         req = desc->orq;
 358         usb_fill_control_urb(
 359                 desc->command,
 360                 interface_to_usbdev(desc->intf),
 361                 /* using common endpoint 0 */
 362                 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
 363                 (unsigned char *)req,
 364                 buf,
 365                 count,
 366                 wdm_out_callback,
 367                 desc
 368         );
 369
 370         req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
 371                              USB_RECIP_INTERFACE);
 372         req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
 373         req->wValue = 0;
 374         req->wIndex = desc->inum;
 375         req->wLength = cpu_to_le16(count);
 376         set_bit(WDM_IN_USE, &desc->flags);
 377
 378         rv = usb_submit_urb(desc->command, GFP_KERNEL);
 379         if (rv < 0) {
 380                 kfree(buf);
 381                 clear_bit(WDM_IN_USE, &desc->flags);
 382                 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
 383         } else {
 384                 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
 385                         req->wIndex);
 386         }
 387 out:
 388         usb_autopm_put_interface(desc->intf);
 389 outnp:
 390         mutex_unlock(&desc->wlock);
 391 outnl:
 392         return rv < 0 ? rv : count;
 393 }
 394
 395 static ssize_t wdm_read
 396 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 397 {
 398         int rv, cntr = 0;
 399         int i = 0;
 400         struct wdm_device *desc = file->private_data;
 401
 402
 403         rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
 404         if (rv < 0)
 405                 return -ERESTARTSYS;
 406
 407         if (desc->length == 0) {
 408                 desc->read = 0;
 409 retry:
 410                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 411                         rv = -ENODEV;
 412                         goto err;
 413                 }
 414                 i++;
 415                 if (file->f_flags & O_NONBLOCK) {
 416                         if (!test_bit(WDM_READ, &desc->flags)) {
 417                                 rv = cntr ? cntr : -EAGAIN;
 418                                 goto err;
 419                         }
 420                         rv = 0;
 421                 } else {
 422                         rv = wait_event_interruptible(desc->wait,
 423                                 test_bit(WDM_READ, &desc->flags));
 424                 }
 425
 426                 /* may have happened while we slept */
 427                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 428                         rv = -ENODEV;
 429                         goto err;
 430                 }
 431                 usb_mark_last_busy(interface_to_usbdev(desc->intf));
 432                 if (rv < 0) {
 433                         rv = -ERESTARTSYS;
 434                         goto err;
 435                 }
 436
 437                 spin_lock_irq(&desc->iuspin);
 438
 439                 if (desc->rerr) { /* read completed, error happened */
 440                         desc->rerr = 0;
 441                         spin_unlock_irq(&desc->iuspin);
 442                         rv = -EIO;
 443                         goto err;
 444                 }
 445                 /*
 446                  * recheck whether we've lost the race
 447                  * against the completion handler
 448                  */
 449                 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
 450                         spin_unlock_irq(&desc->iuspin);
 451                         goto retry;
 452                 }
 453                 if (!desc->reslength) { /* zero length read */
 454                         spin_unlock_irq(&desc->iuspin);
 455                         goto retry;
 456                 }
 457                 clear_bit(WDM_READ, &desc->flags);
 458                 spin_unlock_irq(&desc->iuspin);
 459         }
 460
 461         cntr = count > desc->length ? desc->length : count;
 462         rv = copy_to_user(buffer, desc->ubuf, cntr);
 463         if (rv > 0) {
 464                 rv = -EFAULT;
 465                 goto err;
 466         }
 467
 468         for (i = 0; i < desc->length - cntr; i++)
 469                 desc->ubuf[i] = desc->ubuf[i + cntr];
 470
 471         spin_lock_irq(&desc->iuspin);
 472         desc->length -= cntr;
 473         spin_unlock_irq(&desc->iuspin);
 474         /* in case we had outstanding data */
 475         if (!desc->length)
 476                 clear_bit(WDM_READ, &desc->flags);
 477         rv = cntr;
 478
 479 err:
 480         mutex_unlock(&desc->rlock);
 481         return rv;
 482 }
 483
 484 static int wdm_flush(struct file *file, fl_owner_t id)
 485 {
 486         struct wdm_device *desc = file->private_data;
 487
 488         wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
 489         if (desc->werr < 0)
 490                 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
 491                         desc->werr);
 492
 493         return desc->werr;
 494 }
 495
 496 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
 497 {
 498         struct wdm_device *desc = file->private_data;
 499         unsigned long flags;
 500         unsigned int mask = 0;
 501
 502         spin_lock_irqsave(&desc->iuspin, flags);
 503         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 504                 mask = POLLERR;
 505                 spin_unlock_irqrestore(&desc->iuspin, flags);
 506                 goto desc_out;
 507         }
 508         if (test_bit(WDM_READ, &desc->flags))
 509                 mask = POLLIN | POLLRDNORM;
 510         if (desc->rerr || desc->werr)
 511                 mask |= POLLERR;
 512         if (!test_bit(WDM_IN_USE, &desc->flags))
 513                 mask |= POLLOUT | POLLWRNORM;
 514         spin_unlock_irqrestore(&desc->iuspin, flags);
 515
 516         poll_wait(file, &desc->wait, wait);
 517
 518 desc_out:
 519         return mask;
 520 }
 521
 522 static int wdm_open(struct inode *inode, struct file *file)
 523 {
 524         int minor = iminor(inode);
 525         int rv = -ENODEV;
 526         struct usb_interface *intf;
 527         struct wdm_device *desc;
 528
 529         mutex_lock(&wdm_mutex);
 530         intf = usb_find_interface(&wdm_driver, minor);
 531         if (!intf)
 532                 goto out;
 533
 534         desc = usb_get_intfdata(intf);
 535         if (test_bit(WDM_DISCONNECTING, &desc->flags))
 536                 goto out;
 537         file->private_data = desc;
 538
 539         rv = usb_autopm_get_interface(desc->intf);
 540         if (rv < 0) {
 541                 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
 542                 goto out;
 543         }
 544         intf->needs_remote_wakeup = 1;
 545
 546         /* using write lock to protect desc->count */
 547         mutex_lock(&desc->wlock);
 548         if (!desc->count++) {
 549                 desc->werr = 0;
 550                 desc->rerr = 0;
 551                 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
 552                 if (rv < 0) {
 553                         desc->count--;
 554                         dev_err(&desc->intf->dev,
 555                                 "Error submitting int urb - %d\n", rv);
 556                 }
 557         } else {
 558                 rv = 0;
 559         }
 560         mutex_unlock(&desc->wlock);
 561         usb_autopm_put_interface(desc->intf);
 562 out:
 563         mutex_unlock(&wdm_mutex);
 564         return rv;
 565 }
 566
 567 static int wdm_release(struct inode *inode, struct file *file)
 568 {
 569         struct wdm_device *desc = file->private_data;
 570
 571         mutex_lock(&wdm_mutex);
 572
 573         /* using write lock to protect desc->count */
 574         mutex_lock(&desc->wlock);
 575         desc->count--;
 576         mutex_unlock(&desc->wlock);
 577
 578         if (!desc->count) {
 579                 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
 580                 kill_urbs(desc);
 581                 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 582                         desc->intf->needs_remote_wakeup = 0;
 583         }
 584         mutex_unlock(&wdm_mutex);
 585         return 0;
 586 }
 587
 588 static const struct file_operations wdm_fops = {
 589         .owner =        THIS_MODULE,
 590         .read =         wdm_read,
 591         .write =        wdm_write,
 592         .open =         wdm_open,
 593         .flush =        wdm_flush,
 594         .release =      wdm_release,
 595         .poll =         wdm_poll,
 596         .llseek =       noop_llseek,
 597 };
 598
 599 static struct usb_class_driver wdm_class = {
 600         .name =         "cdc-wdm%d",
 601         .fops =         &wdm_fops,
 602         .minor_base =   WDM_MINOR_BASE,
 603 };
 604
 605 /* --- error handling --- */
 606 static void wdm_rxwork(struct work_struct *work)
 607 {
 608         struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
 609         unsigned long flags;
 610         int rv;
 611
 612         spin_lock_irqsave(&desc->iuspin, flags);
 613         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 614                 spin_unlock_irqrestore(&desc->iuspin, flags);
 615         } else {
 616                 spin_unlock_irqrestore(&desc->iuspin, flags);
 617                 rv = usb_submit_urb(desc->response, GFP_KERNEL);
 618                 if (rv < 0 && rv != -EPERM) {
 619                         spin_lock_irqsave(&desc->iuspin, flags);
 620                         if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 621                                 schedule_work(&desc->rxwork);
 622                         spin_unlock_irqrestore(&desc->iuspin, flags);
 623                 }
 624         }
 625 }
 626
 627 /* --- hotplug --- */
 628
 629 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
 630 {
 631         int rv = -EINVAL;
 632         struct usb_device *udev = interface_to_usbdev(intf);
 633         struct wdm_device *desc;
 634         struct usb_host_interface *iface;
 635         struct usb_endpoint_descriptor *ep;
 636         struct usb_cdc_dmm_desc *dmhd;
 637         u8 *buffer = intf->altsetting->extra;
 638         int buflen = intf->altsetting->extralen;
 639         u16 maxcom = 0;
 640
 641         if (!buffer)
 642                 goto out;
 643
 644         while (buflen > 2) {
 645                 if (buffer [1] != USB_DT_CS_INTERFACE) {
 646                         dev_err(&intf->dev, "skipping garbage\n");
 647                         goto next_desc;
 648                 }
 649
 650                 switch (buffer [2]) {
 651                 case USB_CDC_HEADER_TYPE:
 652                         break;
 653                 case USB_CDC_DMM_TYPE:
 654                         dmhd = (struct usb_cdc_dmm_desc *)buffer;
 655                         maxcom = le16_to_cpu(dmhd->wMaxCommand);
 656                         dev_dbg(&intf->dev,
 657                                 "Finding maximum buffer length: %d", maxcom);
 658                         break;
 659                 default:
 660                         dev_err(&intf->dev,
 661                                 "Ignoring extra header, type %d, length %d\n",
 662                                 buffer[2], buffer[0]);
 663                         break;
 664                 }
 665 next_desc:
 666                 buflen -= buffer[0];
 667                 buffer += buffer[0];
 668         }
 669
 670         rv = -ENOMEM;
 671         desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
 672         if (!desc)
 673                 goto out;
 674         mutex_init(&desc->rlock);
 675         mutex_init(&desc->wlock);
 676         spin_lock_init(&desc->iuspin);
 677         init_waitqueue_head(&desc->wait);
 678         desc->wMaxCommand = maxcom;
 679         /* this will be expanded and needed in hardware endianness */
 680         desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
 681         desc->intf = intf;
 682         INIT_WORK(&desc->rxwork, wdm_rxwork);
 683
 684         rv = -EINVAL;
 685         iface = intf->cur_altsetting;
 686         if (iface->desc.bNumEndpoints != 1)
 687                 goto err;
 688         ep = &iface->endpoint[0].desc;
 689         if (!ep || !usb_endpoint_is_int_in(ep))
 690                 goto err;
 691
 692         desc->wMaxPacketSize = le16_to_cpu(ep->wMaxPacketSize);
 693         desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0;
 694
 695         desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 696         if (!desc->orq)
 697                 goto err;
 698         desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 699         if (!desc->irq)
 700                 goto err;
 701
 702         desc->validity = usb_alloc_urb(0, GFP_KERNEL);
 703         if (!desc->validity)
 704                 goto err;
 705
 706         desc->response = usb_alloc_urb(0, GFP_KERNEL);
 707         if (!desc->response)
 708                 goto err;
 709
 710         desc->command = usb_alloc_urb(0, GFP_KERNEL);
 711         if (!desc->command)
 712                 goto err;
 713
 714         desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
 715         if (!desc->ubuf)
 716                 goto err;
 717
 718         desc->sbuf = usb_alloc_coherent(interface_to_usbdev(intf),
 719                                         desc->wMaxPacketSize,
 720                                         GFP_KERNEL,
 721                                         &desc->validity->transfer_dma);
 722         if (!desc->sbuf)
 723                 goto err;
 724
 725         desc->inbuf = usb_alloc_coherent(interface_to_usbdev(intf),
 726                                          desc->wMaxCommand,
 727                                          GFP_KERNEL,
 728                                          &desc->response->transfer_dma);
 729         if (!desc->inbuf)
 730                 goto err2;
 731
 732         usb_fill_int_urb(
 733                 desc->validity,
 734                 interface_to_usbdev(intf),
 735                 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
 736                 desc->sbuf,
 737                 desc->wMaxPacketSize,
 738                 wdm_int_callback,
 739                 desc,
 740                 ep->bInterval
 741         );
 742         desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 743
 744         usb_set_intfdata(intf, desc);
 745         rv = usb_register_dev(intf, &wdm_class);
 746         if (rv < 0)
 747                 goto err3;
 748         else
 749                 dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
 750                         intf->minor - WDM_MINOR_BASE);
 751 out:
 752         return rv;
 753 err3:
 754         usb_set_intfdata(intf, NULL);
 755         usb_free_coherent(interface_to_usbdev(desc->intf),
 756                           desc->bMaxPacketSize0,
 757                         desc->inbuf,
 758                         desc->response->transfer_dma);
 759 err2:
 760         usb_free_coherent(interface_to_usbdev(desc->intf),
 761                           desc->wMaxPacketSize,
 762                           desc->sbuf,
 763                           desc->validity->transfer_dma);
 764 err:
 765         free_urbs(desc);
 766         kfree(desc->ubuf);
 767         kfree(desc->orq);
 768         kfree(desc->irq);
 769         kfree(desc);
 770         return rv;
 771 }
 772
 773 static void wdm_disconnect(struct usb_interface *intf)
 774 {
 775         struct wdm_device *desc;
 776         unsigned long flags;
 777
 778         usb_deregister_dev(intf, &wdm_class);
 779         mutex_lock(&wdm_mutex);
 780         desc = usb_get_intfdata(intf);
 781
 782         /* the spinlock makes sure no new urbs are generated in the callbacks */
 783         spin_lock_irqsave(&desc->iuspin, flags);
 784         set_bit(WDM_DISCONNECTING, &desc->flags);
 785         set_bit(WDM_READ, &desc->flags);
 786         /* to terminate pending flushes */
 787         clear_bit(WDM_IN_USE, &desc->flags);
 788         spin_unlock_irqrestore(&desc->iuspin, flags);
 789         wake_up_all(&desc->wait);
 790         mutex_lock(&desc->rlock);
 791         mutex_lock(&desc->wlock);
 792         kill_urbs(desc);
 793         cancel_work_sync(&desc->rxwork);
 794         mutex_unlock(&desc->wlock);
 795         mutex_unlock(&desc->rlock);
 796         if (!desc->count)
 797                 cleanup(desc);
 798         mutex_unlock(&wdm_mutex);
 799 }
 800
 801 #ifdef CONFIG_PM
 802 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
 803 {
 804         struct wdm_device *desc = usb_get_intfdata(intf);
 805         int rv = 0;
 806
 807         dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
 808
 809         /* if this is an autosuspend the caller does the locking */
 810         if (!(message.event & PM_EVENT_AUTO)) {
 811                 mutex_lock(&desc->rlock);
 812                 mutex_lock(&desc->wlock);
 813         }
 814         spin_lock_irq(&desc->iuspin);
 815
 816         if ((message.event & PM_EVENT_AUTO) &&
 817                         (test_bit(WDM_IN_USE, &desc->flags)
 818                         || test_bit(WDM_RESPONDING, &desc->flags))) {
 819                 spin_unlock_irq(&desc->iuspin);
 820                 rv = -EBUSY;
 821         } else {
 822
 823                 set_bit(WDM_SUSPENDING, &desc->flags);
 824                 spin_unlock_irq(&desc->iuspin);
 825                 /* callback submits work - order is essential */
 826                 kill_urbs(desc);
 827                 cancel_work_sync(&desc->rxwork);
 828         }
 829         if (!(message.event & PM_EVENT_AUTO)) {
 830                 mutex_unlock(&desc->wlock);
 831                 mutex_unlock(&desc->rlock);
 832         }
 833
 834         return rv;
 835 }
 836 #endif
 837
 838 static int recover_from_urb_loss(struct wdm_device *desc)
 839 {
 840         int rv = 0;
 841
 842         if (desc->count) {
 843                 rv = usb_submit_urb(desc->validity, GFP_NOIO);
 844                 if (rv < 0)
 845                         dev_err(&desc->intf->dev,
 846                                 "Error resume submitting int urb - %d\n", rv);
 847         }
 848         return rv;
 849 }
 850
 851 #ifdef CONFIG_PM
 852 static int wdm_resume(struct usb_interface *intf)
 853 {
 854         struct wdm_device *desc = usb_get_intfdata(intf);
 855         int rv;
 856
 857         dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
 858
 859         clear_bit(WDM_SUSPENDING, &desc->flags);
 860         rv = recover_from_urb_loss(desc);
 861
 862         return rv;
 863 }
 864 #endif
 865
 866 static int wdm_pre_reset(struct usb_interface *intf)
 867 {
 868         struct wdm_device *desc = usb_get_intfdata(intf);
 869
 870         mutex_lock(&desc->rlock);
 871         mutex_lock(&desc->wlock);
 872         kill_urbs(desc);
 873
 874         /*
 875          * we notify everybody using poll of
 876          * an exceptional situation
 877          * must be done before recovery lest a spontaneous
 878          * message from the device is lost
 879          */
 880         spin_lock_irq(&desc->iuspin);
 881         desc->rerr = -EINTR;
 882         spin_unlock_irq(&desc->iuspin);
 883         wake_up_all(&desc->wait);
 884         return 0;
 885 }
 886
 887 static int wdm_post_reset(struct usb_interface *intf)
 888 {
 889         struct wdm_device *desc = usb_get_intfdata(intf);
 890         int rv;
 891
 892         rv = recover_from_urb_loss(desc);
 893         mutex_unlock(&desc->wlock);
 894         mutex_unlock(&desc->rlock);
 895         return 0;
 896 }
 897
 898 static struct usb_driver wdm_driver = {
 899         .name =         "cdc_wdm",
 900         .probe =        wdm_probe,
 901         .disconnect =   wdm_disconnect,
 902 #ifdef CONFIG_PM
 903         .suspend =      wdm_suspend,
 904         .resume =       wdm_resume,
 905         .reset_resume = wdm_resume,
 906 #endif
 907         .pre_reset =    wdm_pre_reset,
 908         .post_reset =   wdm_post_reset,
 909         .id_table =     wdm_ids,
 910         .supports_autosuspend = 1,
 911 };
 912
 913 /* --- low level module stuff --- */
 914
 915 static int __init wdm_init(void)
 916 {
 917         int rv;
 918
 919         rv = usb_register(&wdm_driver);
 920
 921         return rv;
 922 }
 923
 924 static void __exit wdm_exit(void)
 925 {
 926         usb_deregister(&wdm_driver);
 927 }
 928
 929 module_init(wdm_init);
 930 module_exit(wdm_exit);
 931
 932 MODULE_AUTHOR(DRIVER_AUTHOR);
 933 MODULE_DESCRIPTION(DRIVER_DESC);
 934 MODULE_LICENSE("GPL");