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