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 #define HUAWEI_VENDOR_ID        0x12D1
  35
  36 static const struct usb_device_id wdm_ids[] = {
  37         {
  38                 .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS |
  39                                  USB_DEVICE_ID_MATCH_INT_SUBCLASS,
  40                 .bInterfaceClass = USB_CLASS_COMM,
  41                 .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM
  42         },
  43         {
  44                 /*
  45                  * Huawei E392, E398 and possibly other Qualcomm based modems
  46                  * embed the Qualcomm QMI protocol inside CDC on CDC ECM like
  47                  * control interfaces.  Userspace access to this is required
  48                  * to configure the accompanying data interface
  49                  */
  50                 .match_flags        = USB_DEVICE_ID_MATCH_VENDOR |
  51                                         USB_DEVICE_ID_MATCH_INT_INFO,
  52                 .idVendor           = HUAWEI_VENDOR_ID,
  53                 .bInterfaceClass    = USB_CLASS_VENDOR_SPEC,
  54                 .bInterfaceSubClass = 1,
  55                 .bInterfaceProtocol = 9, /* NOTE: CDC ECM control interface! */
  56         },
  57         { }
  58 };
  59
  60 MODULE_DEVICE_TABLE (usb, wdm_ids);
  61
  62 #define WDM_MINOR_BASE  176
  63
  64
  65 #define WDM_IN_USE              1
  66 #define WDM_DISCONNECTING       2
  67 #define WDM_RESULT              3
  68 #define WDM_READ                4
  69 #define WDM_INT_STALL           5
  70 #define WDM_POLL_RUNNING        6
  71 #define WDM_RESPONDING          7
  72 #define WDM_SUSPENDING          8
  73
  74 #define WDM_MAX                 16
  75
  76 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
  77 #define WDM_DEFAULT_BUFSIZE     256
  78
  79 static DEFINE_MUTEX(wdm_mutex);
  80
  81 /* --- method tables --- */
  82
  83 struct wdm_device {
  84         u8                      *inbuf; /* buffer for response */
  85         u8                      *outbuf; /* buffer for command */
  86         u8                      *sbuf; /* buffer for status */
  87         u8                      *ubuf; /* buffer for copy to user space */
  88
  89         struct urb              *command;
  90         struct urb              *response;
  91         struct urb              *validity;
  92         struct usb_interface    *intf;
  93         struct usb_ctrlrequest  *orq;
  94         struct usb_ctrlrequest  *irq;
  95         spinlock_t              iuspin;
  96
  97         unsigned long           flags;
  98         u16                     bufsize;
  99         u16                     wMaxCommand;
 100         u16                     wMaxPacketSize;
 101         __le16                  inum;
 102         int                     reslength;
 103         int                     length;
 104         int                     read;
 105         int                     count;
 106         dma_addr_t              shandle;
 107         dma_addr_t              ihandle;
 108         struct mutex            lock;
 109         wait_queue_head_t       wait;
 110         struct work_struct      rxwork;
 111         int                     werr;
 112         int                     rerr;
 113 };
 114
 115 static struct usb_driver wdm_driver;
 116
 117 /* --- callbacks --- */
 118 static void wdm_out_callback(struct urb *urb)
 119 {
 120         struct wdm_device *desc;
 121         desc = urb->context;
 122         spin_lock(&desc->iuspin);
 123         desc->werr = urb->status;
 124         spin_unlock(&desc->iuspin);
 125         clear_bit(WDM_IN_USE, &desc->flags);
 126         kfree(desc->outbuf);
 127         wake_up(&desc->wait);
 128 }
 129
 130 static void wdm_in_callback(struct urb *urb)
 131 {
 132         struct wdm_device *desc = urb->context;
 133         int status = urb->status;
 134
 135         spin_lock(&desc->iuspin);
 136         clear_bit(WDM_RESPONDING, &desc->flags);
 137
 138         if (status) {
 139                 switch (status) {
 140                 case -ENOENT:
 141                         dev_dbg(&desc->intf->dev,
 142                                 "nonzero urb status received: -ENOENT");
 143                         goto skip_error;
 144                 case -ECONNRESET:
 145                         dev_dbg(&desc->intf->dev,
 146                                 "nonzero urb status received: -ECONNRESET");
 147                         goto skip_error;
 148                 case -ESHUTDOWN:
 149                         dev_dbg(&desc->intf->dev,
 150                                 "nonzero urb status received: -ESHUTDOWN");
 151                         goto skip_error;
 152                 case -EPIPE:
 153                         dev_err(&desc->intf->dev,
 154                                 "nonzero urb status received: -EPIPE\n");
 155                         break;
 156                 default:
 157                         dev_err(&desc->intf->dev,
 158                                 "Unexpected error %d\n", status);
 159                         break;
 160                 }
 161         }
 162
 163         desc->rerr = status;
 164         desc->reslength = urb->actual_length;
 165         memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
 166         desc->length += desc->reslength;
 167 skip_error:
 168         wake_up(&desc->wait);
 169
 170         set_bit(WDM_READ, &desc->flags);
 171         spin_unlock(&desc->iuspin);
 172 }
 173
 174 static void wdm_int_callback(struct urb *urb)
 175 {
 176         int rv = 0;
 177         int status = urb->status;
 178         struct wdm_device *desc;
 179         struct usb_cdc_notification *dr;
 180
 181         desc = urb->context;
 182         dr = (struct usb_cdc_notification *)desc->sbuf;
 183
 184         if (status) {
 185                 switch (status) {
 186                 case -ESHUTDOWN:
 187                 case -ENOENT:
 188                 case -ECONNRESET:
 189                         return; /* unplug */
 190                 case -EPIPE:
 191                         set_bit(WDM_INT_STALL, &desc->flags);
 192                         dev_err(&desc->intf->dev, "Stall on int endpoint\n");
 193                         goto sw; /* halt is cleared in work */
 194                 default:
 195                         dev_err(&desc->intf->dev,
 196                                 "nonzero urb status received: %d\n", status);
 197                         break;
 198                 }
 199         }
 200
 201         if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
 202                 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
 203                         urb->actual_length);
 204                 goto exit;
 205         }
 206
 207         switch (dr->bNotificationType) {
 208         case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
 209                 dev_dbg(&desc->intf->dev,
 210                         "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
 211                         dr->wIndex, dr->wLength);
 212                 break;
 213
 214         case USB_CDC_NOTIFY_NETWORK_CONNECTION:
 215
 216                 dev_dbg(&desc->intf->dev,
 217                         "NOTIFY_NETWORK_CONNECTION %s network",
 218                         dr->wValue ? "connected to" : "disconnected from");
 219                 goto exit;
 220         default:
 221                 clear_bit(WDM_POLL_RUNNING, &desc->flags);
 222                 dev_err(&desc->intf->dev,
 223                         "unknown notification %d received: index %d len %d\n",
 224                         dr->bNotificationType, dr->wIndex, dr->wLength);
 225                 goto exit;
 226         }
 227
 228         spin_lock(&desc->iuspin);
 229         clear_bit(WDM_READ, &desc->flags);
 230         set_bit(WDM_RESPONDING, &desc->flags);
 231         if (!test_bit(WDM_DISCONNECTING, &desc->flags)
 232                 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
 233                 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
 234                 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
 235                         __func__, rv);
 236         }
 237         spin_unlock(&desc->iuspin);
 238         if (rv < 0) {
 239                 clear_bit(WDM_RESPONDING, &desc->flags);
 240                 if (rv == -EPERM)
 241                         return;
 242                 if (rv == -ENOMEM) {
 243 sw:
 244                         rv = schedule_work(&desc->rxwork);
 245                         if (rv)
 246                                 dev_err(&desc->intf->dev,
 247                                         "Cannot schedule work\n");
 248                 }
 249         }
 250 exit:
 251         rv = usb_submit_urb(urb, GFP_ATOMIC);
 252         if (rv)
 253                 dev_err(&desc->intf->dev,
 254                         "%s - usb_submit_urb failed with result %d\n",
 255                         __func__, rv);
 256
 257 }
 258
 259 static void kill_urbs(struct wdm_device *desc)
 260 {
 261         /* the order here is essential */
 262         usb_kill_urb(desc->command);
 263         usb_kill_urb(desc->validity);
 264         usb_kill_urb(desc->response);
 265 }
 266
 267 static void free_urbs(struct wdm_device *desc)
 268 {
 269         usb_free_urb(desc->validity);
 270         usb_free_urb(desc->response);
 271         usb_free_urb(desc->command);
 272 }
 273
 274 static void cleanup(struct wdm_device *desc)
 275 {
 276         kfree(desc->sbuf);
 277         kfree(desc->inbuf);
 278         kfree(desc->orq);
 279         kfree(desc->irq);
 280         kfree(desc->ubuf);
 281         free_urbs(desc);
 282         kfree(desc);
 283 }
 284
 285 static ssize_t wdm_write
 286 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 287 {
 288         u8 *buf;
 289         int rv = -EMSGSIZE, r, we;
 290         struct wdm_device *desc = file->private_data;
 291         struct usb_ctrlrequest *req;
 292
 293         if (count > desc->wMaxCommand)
 294                 count = desc->wMaxCommand;
 295
 296         spin_lock_irq(&desc->iuspin);
 297         we = desc->werr;
 298         desc->werr = 0;
 299         spin_unlock_irq(&desc->iuspin);
 300         if (we < 0)
 301                 return -EIO;
 302
 303         desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
 304         if (!buf) {
 305                 rv = -ENOMEM;
 306                 goto outnl;
 307         }
 308
 309         r = copy_from_user(buf, buffer, count);
 310         if (r > 0) {
 311                 kfree(buf);
 312                 rv = -EFAULT;
 313                 goto outnl;
 314         }
 315
 316         /* concurrent writes and disconnect */
 317         r = mutex_lock_interruptible(&desc->lock);
 318         rv = -ERESTARTSYS;
 319         if (r) {
 320                 kfree(buf);
 321                 goto outnl;
 322         }
 323
 324         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 325                 kfree(buf);
 326                 rv = -ENODEV;
 327                 goto outnp;
 328         }
 329
 330         r = usb_autopm_get_interface(desc->intf);
 331         if (r < 0) {
 332                 kfree(buf);
 333                 goto outnp;
 334         }
 335
 336         if (!(file->f_flags & O_NONBLOCK))
 337                 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
 338                                                                 &desc->flags));
 339         else
 340                 if (test_bit(WDM_IN_USE, &desc->flags))
 341                         r = -EAGAIN;
 342         if (r < 0) {
 343                 kfree(buf);
 344                 goto out;
 345         }
 346
 347         req = desc->orq;
 348         usb_fill_control_urb(
 349                 desc->command,
 350                 interface_to_usbdev(desc->intf),
 351                 /* using common endpoint 0 */
 352                 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
 353                 (unsigned char *)req,
 354                 buf,
 355                 count,
 356                 wdm_out_callback,
 357                 desc
 358         );
 359
 360         req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
 361                              USB_RECIP_INTERFACE);
 362         req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
 363         req->wValue = 0;
 364         req->wIndex = desc->inum;
 365         req->wLength = cpu_to_le16(count);
 366         set_bit(WDM_IN_USE, &desc->flags);
 367
 368         rv = usb_submit_urb(desc->command, GFP_KERNEL);
 369         if (rv < 0) {
 370                 kfree(buf);
 371                 clear_bit(WDM_IN_USE, &desc->flags);
 372                 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
 373         } else {
 374                 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
 375                         req->wIndex);
 376         }
 377 out:
 378         usb_autopm_put_interface(desc->intf);
 379 outnp:
 380         mutex_unlock(&desc->lock);
 381 outnl:
 382         return rv < 0 ? rv : count;
 383 }
 384
 385 static ssize_t wdm_read
 386 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 387 {
 388         int rv, cntr = 0;
 389         int i = 0;
 390         struct wdm_device *desc = file->private_data;
 391
 392
 393         rv = mutex_lock_interruptible(&desc->lock); /*concurrent reads */
 394         if (rv < 0)
 395                 return -ERESTARTSYS;
 396
 397         if (desc->length == 0) {
 398                 desc->read = 0;
 399 retry:
 400                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 401                         rv = -ENODEV;
 402                         goto err;
 403                 }
 404                 i++;
 405                 if (file->f_flags & O_NONBLOCK) {
 406                         if (!test_bit(WDM_READ, &desc->flags)) {
 407                                 rv = cntr ? cntr : -EAGAIN;
 408                                 goto err;
 409                         }
 410                         rv = 0;
 411                 } else {
 412                         rv = wait_event_interruptible(desc->wait,
 413                                 test_bit(WDM_READ, &desc->flags));
 414                 }
 415
 416                 /* may have happened while we slept */
 417                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 418                         rv = -ENODEV;
 419                         goto err;
 420                 }
 421                 usb_mark_last_busy(interface_to_usbdev(desc->intf));
 422                 if (rv < 0) {
 423                         rv = -ERESTARTSYS;
 424                         goto err;
 425                 }
 426
 427                 spin_lock_irq(&desc->iuspin);
 428
 429                 if (desc->rerr) { /* read completed, error happened */
 430                         desc->rerr = 0;
 431                         spin_unlock_irq(&desc->iuspin);
 432                         rv = -EIO;
 433                         goto err;
 434                 }
 435                 /*
 436                  * recheck whether we've lost the race
 437                  * against the completion handler
 438                  */
 439                 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
 440                         spin_unlock_irq(&desc->iuspin);
 441                         goto retry;
 442                 }
 443                 if (!desc->reslength) { /* zero length read */
 444                         spin_unlock_irq(&desc->iuspin);
 445                         goto retry;
 446                 }
 447                 clear_bit(WDM_READ, &desc->flags);
 448                 spin_unlock_irq(&desc->iuspin);
 449         }
 450
 451         cntr = count > desc->length ? desc->length : count;
 452         rv = copy_to_user(buffer, desc->ubuf, cntr);
 453         if (rv > 0) {
 454                 rv = -EFAULT;
 455                 goto err;
 456         }
 457
 458         for (i = 0; i < desc->length - cntr; i++)
 459                 desc->ubuf[i] = desc->ubuf[i + cntr];
 460
 461         desc->length -= cntr;
 462         /* in case we had outstanding data */
 463         if (!desc->length)
 464                 clear_bit(WDM_READ, &desc->flags);
 465         rv = cntr;
 466
 467 err:
 468         mutex_unlock(&desc->lock);
 469         return rv;
 470 }
 471
 472 static int wdm_flush(struct file *file, fl_owner_t id)
 473 {
 474         struct wdm_device *desc = file->private_data;
 475
 476         wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
 477         if (desc->werr < 0)
 478                 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
 479                         desc->werr);
 480
 481         return desc->werr;
 482 }
 483
 484 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
 485 {
 486         struct wdm_device *desc = file->private_data;
 487         unsigned long flags;
 488         unsigned int mask = 0;
 489
 490         spin_lock_irqsave(&desc->iuspin, flags);
 491         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 492                 mask = POLLERR;
 493                 spin_unlock_irqrestore(&desc->iuspin, flags);
 494                 goto desc_out;
 495         }
 496         if (test_bit(WDM_READ, &desc->flags))
 497                 mask = POLLIN | POLLRDNORM;
 498         if (desc->rerr || desc->werr)
 499                 mask |= POLLERR;
 500         if (!test_bit(WDM_IN_USE, &desc->flags))
 501                 mask |= POLLOUT | POLLWRNORM;
 502         spin_unlock_irqrestore(&desc->iuspin, flags);
 503
 504         poll_wait(file, &desc->wait, wait);
 505
 506 desc_out:
 507         return mask;
 508 }
 509
 510 static int wdm_open(struct inode *inode, struct file *file)
 511 {
 512         int minor = iminor(inode);
 513         int rv = -ENODEV;
 514         struct usb_interface *intf;
 515         struct wdm_device *desc;
 516
 517         mutex_lock(&wdm_mutex);
 518         intf = usb_find_interface(&wdm_driver, minor);
 519         if (!intf)
 520                 goto out;
 521
 522         desc = usb_get_intfdata(intf);
 523         if (test_bit(WDM_DISCONNECTING, &desc->flags))
 524                 goto out;
 525         file->private_data = desc;
 526
 527         rv = usb_autopm_get_interface(desc->intf);
 528         if (rv < 0) {
 529                 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
 530                 goto out;
 531         }
 532         intf->needs_remote_wakeup = 1;
 533
 534         mutex_lock(&desc->lock);
 535         if (!desc->count++) {
 536                 desc->werr = 0;
 537                 desc->rerr = 0;
 538                 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
 539                 if (rv < 0) {
 540                         desc->count--;
 541                         dev_err(&desc->intf->dev,
 542                                 "Error submitting int urb - %d\n", rv);
 543                 }
 544         } else {
 545                 rv = 0;
 546         }
 547         mutex_unlock(&desc->lock);
 548         usb_autopm_put_interface(desc->intf);
 549 out:
 550         mutex_unlock(&wdm_mutex);
 551         return rv;
 552 }
 553
 554 static int wdm_release(struct inode *inode, struct file *file)
 555 {
 556         struct wdm_device *desc = file->private_data;
 557
 558         mutex_lock(&wdm_mutex);
 559         mutex_lock(&desc->lock);
 560         desc->count--;
 561         mutex_unlock(&desc->lock);
 562
 563         if (!desc->count) {
 564                 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
 565                 kill_urbs(desc);
 566                 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 567                         desc->intf->needs_remote_wakeup = 0;
 568         }
 569         mutex_unlock(&wdm_mutex);
 570         return 0;
 571 }
 572
 573 static const struct file_operations wdm_fops = {
 574         .owner =        THIS_MODULE,
 575         .read =         wdm_read,
 576         .write =        wdm_write,
 577         .open =         wdm_open,
 578         .flush =        wdm_flush,
 579         .release =      wdm_release,
 580         .poll =         wdm_poll,
 581         .llseek =       noop_llseek,
 582 };
 583
 584 static struct usb_class_driver wdm_class = {
 585         .name =         "cdc-wdm%d",
 586         .fops =         &wdm_fops,
 587         .minor_base =   WDM_MINOR_BASE,
 588 };
 589
 590 /* --- error handling --- */
 591 static void wdm_rxwork(struct work_struct *work)
 592 {
 593         struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
 594         unsigned long flags;
 595         int rv;
 596
 597         spin_lock_irqsave(&desc->iuspin, flags);
 598         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 599                 spin_unlock_irqrestore(&desc->iuspin, flags);
 600         } else {
 601                 spin_unlock_irqrestore(&desc->iuspin, flags);
 602                 rv = usb_submit_urb(desc->response, GFP_KERNEL);
 603                 if (rv < 0 && rv != -EPERM) {
 604                         spin_lock_irqsave(&desc->iuspin, flags);
 605                         if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 606                                 schedule_work(&desc->rxwork);
 607                         spin_unlock_irqrestore(&desc->iuspin, flags);
 608                 }
 609         }
 610 }
 611
 612 /* --- hotplug --- */
 613
 614 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
 615 {
 616         int rv = -EINVAL;
 617         struct wdm_device *desc;
 618         struct usb_host_interface *iface;
 619         struct usb_endpoint_descriptor *ep;
 620         struct usb_cdc_dmm_desc *dmhd;
 621         u8 *buffer = intf->altsetting->extra;
 622         int buflen = intf->altsetting->extralen;
 623         u16 maxcom = WDM_DEFAULT_BUFSIZE;
 624
 625         if (!buffer)
 626                 goto out;
 627
 628         while (buflen > 2) {
 629                 if (buffer [1] != USB_DT_CS_INTERFACE) {
 630                         dev_err(&intf->dev, "skipping garbage\n");
 631                         goto next_desc;
 632                 }
 633
 634                 switch (buffer [2]) {
 635                 case USB_CDC_HEADER_TYPE:
 636                         break;
 637                 case USB_CDC_DMM_TYPE:
 638                         dmhd = (struct usb_cdc_dmm_desc *)buffer;
 639                         maxcom = le16_to_cpu(dmhd->wMaxCommand);
 640                         dev_dbg(&intf->dev,
 641                                 "Finding maximum buffer length: %d", maxcom);
 642                         break;
 643                 default:
 644                         dev_err(&intf->dev,
 645                                 "Ignoring extra header, type %d, length %d\n",
 646                                 buffer[2], buffer[0]);
 647                         break;
 648                 }
 649 next_desc:
 650                 buflen -= buffer[0];
 651                 buffer += buffer[0];
 652         }
 653
 654         rv = -ENOMEM;
 655         desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
 656         if (!desc)
 657                 goto out;
 658         mutex_init(&desc->lock);
 659         spin_lock_init(&desc->iuspin);
 660         init_waitqueue_head(&desc->wait);
 661         desc->wMaxCommand = maxcom;
 662         /* this will be expanded and needed in hardware endianness */
 663         desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
 664         desc->intf = intf;
 665         INIT_WORK(&desc->rxwork, wdm_rxwork);
 666
 667         rv = -EINVAL;
 668         iface = intf->cur_altsetting;
 669         if (iface->desc.bNumEndpoints != 1)
 670                 goto err;
 671         ep = &iface->endpoint[0].desc;
 672         if (!ep || !usb_endpoint_is_int_in(ep))
 673                 goto err;
 674
 675         desc->wMaxPacketSize = usb_endpoint_maxp(ep);
 676
 677         desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 678         if (!desc->orq)
 679                 goto err;
 680         desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 681         if (!desc->irq)
 682                 goto err;
 683
 684         desc->validity = usb_alloc_urb(0, GFP_KERNEL);
 685         if (!desc->validity)
 686                 goto err;
 687
 688         desc->response = usb_alloc_urb(0, GFP_KERNEL);
 689         if (!desc->response)
 690                 goto err;
 691
 692         desc->command = usb_alloc_urb(0, GFP_KERNEL);
 693         if (!desc->command)
 694                 goto err;
 695
 696         desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
 697         if (!desc->ubuf)
 698                 goto err;
 699
 700         desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
 701         if (!desc->sbuf)
 702                 goto err;
 703
 704         desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
 705         if (!desc->inbuf)
 706                 goto err;
 707
 708         usb_fill_int_urb(
 709                 desc->validity,
 710                 interface_to_usbdev(intf),
 711                 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
 712                 desc->sbuf,
 713                 desc->wMaxPacketSize,
 714                 wdm_int_callback,
 715                 desc,
 716                 ep->bInterval
 717         );
 718
 719         desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
 720         desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
 721         desc->irq->wValue = 0;
 722         desc->irq->wIndex = desc->inum;
 723         desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
 724
 725         usb_fill_control_urb(
 726                 desc->response,
 727                 interface_to_usbdev(intf),
 728                 /* using common endpoint 0 */
 729                 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
 730                 (unsigned char *)desc->irq,
 731                 desc->inbuf,
 732                 desc->wMaxCommand,
 733                 wdm_in_callback,
 734                 desc
 735         );
 736
 737         usb_set_intfdata(intf, desc);
 738         rv = usb_register_dev(intf, &wdm_class);
 739         if (rv < 0)
 740                 goto err2;
 741         else
 742                 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
 743 out:
 744         return rv;
 745 err2:
 746         usb_set_intfdata(intf, NULL);
 747 err:
 748         free_urbs(desc);
 749         kfree(desc->inbuf);
 750         kfree(desc->sbuf);
 751         kfree(desc->ubuf);
 752         kfree(desc->orq);
 753         kfree(desc->irq);
 754         kfree(desc);
 755         return rv;
 756 }
 757
 758 static void wdm_disconnect(struct usb_interface *intf)
 759 {
 760         struct wdm_device *desc;
 761         unsigned long flags;
 762
 763         usb_deregister_dev(intf, &wdm_class);
 764         mutex_lock(&wdm_mutex);
 765         desc = usb_get_intfdata(intf);
 766
 767         /* the spinlock makes sure no new urbs are generated in the callbacks */
 768         spin_lock_irqsave(&desc->iuspin, flags);
 769         set_bit(WDM_DISCONNECTING, &desc->flags);
 770         set_bit(WDM_READ, &desc->flags);
 771         /* to terminate pending flushes */
 772         clear_bit(WDM_IN_USE, &desc->flags);
 773         spin_unlock_irqrestore(&desc->iuspin, flags);
 774         mutex_lock(&desc->lock);
 775         kill_urbs(desc);
 776         cancel_work_sync(&desc->rxwork);
 777         mutex_unlock(&desc->lock);
 778         wake_up_all(&desc->wait);
 779         if (!desc->count)
 780                 cleanup(desc);
 781         mutex_unlock(&wdm_mutex);
 782 }
 783
 784 #ifdef CONFIG_PM
 785 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
 786 {
 787         struct wdm_device *desc = usb_get_intfdata(intf);
 788         int rv = 0;
 789
 790         dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
 791
 792         /* if this is an autosuspend the caller does the locking */
 793         if (!PMSG_IS_AUTO(message))
 794                 mutex_lock(&desc->lock);
 795         spin_lock_irq(&desc->iuspin);
 796
 797         if (PMSG_IS_AUTO(message) &&
 798                         (test_bit(WDM_IN_USE, &desc->flags)
 799                         || test_bit(WDM_RESPONDING, &desc->flags))) {
 800                 spin_unlock_irq(&desc->iuspin);
 801                 rv = -EBUSY;
 802         } else {
 803
 804                 set_bit(WDM_SUSPENDING, &desc->flags);
 805                 spin_unlock_irq(&desc->iuspin);
 806                 /* callback submits work - order is essential */
 807                 kill_urbs(desc);
 808                 cancel_work_sync(&desc->rxwork);
 809         }
 810         if (!PMSG_IS_AUTO(message))
 811                 mutex_unlock(&desc->lock);
 812
 813         return rv;
 814 }
 815 #endif
 816
 817 static int recover_from_urb_loss(struct wdm_device *desc)
 818 {
 819         int rv = 0;
 820
 821         if (desc->count) {
 822                 rv = usb_submit_urb(desc->validity, GFP_NOIO);
 823                 if (rv < 0)
 824                         dev_err(&desc->intf->dev,
 825                                 "Error resume submitting int urb - %d\n", rv);
 826         }
 827         return rv;
 828 }
 829
 830 #ifdef CONFIG_PM
 831 static int wdm_resume(struct usb_interface *intf)
 832 {
 833         struct wdm_device *desc = usb_get_intfdata(intf);
 834         int rv;
 835
 836         dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
 837
 838         clear_bit(WDM_SUSPENDING, &desc->flags);
 839         rv = recover_from_urb_loss(desc);
 840
 841         return rv;
 842 }
 843 #endif
 844
 845 static int wdm_pre_reset(struct usb_interface *intf)
 846 {
 847         struct wdm_device *desc = usb_get_intfdata(intf);
 848
 849         mutex_lock(&desc->lock);
 850         kill_urbs(desc);
 851
 852         /*
 853          * we notify everybody using poll of
 854          * an exceptional situation
 855          * must be done before recovery lest a spontaneous
 856          * message from the device is lost
 857          */
 858         spin_lock_irq(&desc->iuspin);
 859         desc->rerr = -EINTR;
 860         spin_unlock_irq(&desc->iuspin);
 861         wake_up_all(&desc->wait);
 862         return 0;
 863 }
 864
 865 static int wdm_post_reset(struct usb_interface *intf)
 866 {
 867         struct wdm_device *desc = usb_get_intfdata(intf);
 868         int rv;
 869
 870         rv = recover_from_urb_loss(desc);
 871         mutex_unlock(&desc->lock);
 872         return 0;
 873 }
 874
 875 static struct usb_driver wdm_driver = {
 876         .name =         "cdc_wdm",
 877         .probe =        wdm_probe,
 878         .disconnect =   wdm_disconnect,
 879 #ifdef CONFIG_PM
 880         .suspend =      wdm_suspend,
 881         .resume =       wdm_resume,
 882         .reset_resume = wdm_resume,
 883 #endif
 884         .pre_reset =    wdm_pre_reset,
 885         .post_reset =   wdm_post_reset,
 886         .id_table =     wdm_ids,
 887         .supports_autosuspend = 1,
 888 };
 889
 890 module_usb_driver(wdm_driver);
 891
 892 MODULE_AUTHOR(DRIVER_AUTHOR);
 893 MODULE_DESCRIPTION(DRIVER_DESC);
 894 MODULE_LICENSE("GPL");