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 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
  61 #define WDM_DEFAULT_BUFSIZE     256
  62
  63 static DEFINE_MUTEX(wdm_mutex);
  64
  65 /* --- method tables --- */
  66
  67 struct wdm_device {
  68         u8                      *inbuf; /* buffer for response */
  69         u8                      *outbuf; /* buffer for command */
  70         u8                      *sbuf; /* buffer for status */
  71         u8                      *ubuf; /* buffer for copy to user space */
  72
  73         struct urb              *command;
  74         struct urb              *response;
  75         struct urb              *validity;
  76         struct usb_interface    *intf;
  77         struct usb_ctrlrequest  *orq;
  78         struct usb_ctrlrequest  *irq;
  79         spinlock_t              iuspin;
  80
  81         unsigned long           flags;
  82         u16                     bufsize;
  83         u16                     wMaxCommand;
  84         u16                     wMaxPacketSize;
  85         u16                     bMaxPacketSize0;
  86         __le16                  inum;
  87         int                     reslength;
  88         int                     length;
  89         int                     read;
  90         int                     count;
  91         dma_addr_t              shandle;
  92         dma_addr_t              ihandle;
  93         struct mutex            wlock;
  94         struct mutex            rlock;
  95         wait_queue_head_t       wait;
  96         struct work_struct      rxwork;
  97         int                     werr;
  98         int                     rerr;
  99 };
 100
 101 static struct usb_driver wdm_driver;
 102
 103 /* --- callbacks --- */
 104 static void wdm_out_callback(struct urb *urb)
 105 {
 106         struct wdm_device *desc;
 107         desc = urb->context;
 108         spin_lock(&desc->iuspin);
 109         desc->werr = urb->status;
 110         spin_unlock(&desc->iuspin);
 111         clear_bit(WDM_IN_USE, &desc->flags);
 112         kfree(desc->outbuf);
 113         wake_up(&desc->wait);
 114 }
 115
 116 static void wdm_in_callback(struct urb *urb)
 117 {
 118         struct wdm_device *desc = urb->context;
 119         int status = urb->status;
 120
 121         spin_lock(&desc->iuspin);
 122         clear_bit(WDM_RESPONDING, &desc->flags);
 123
 124         if (status) {
 125                 switch (status) {
 126                 case -ENOENT:
 127                         dev_dbg(&desc->intf->dev,
 128                                 "nonzero urb status received: -ENOENT");
 129                         goto skip_error;
 130                 case -ECONNRESET:
 131                         dev_dbg(&desc->intf->dev,
 132                                 "nonzero urb status received: -ECONNRESET");
 133                         goto skip_error;
 134                 case -ESHUTDOWN:
 135                         dev_dbg(&desc->intf->dev,
 136                                 "nonzero urb status received: -ESHUTDOWN");
 137                         goto skip_error;
 138                 case -EPIPE:
 139                         dev_err(&desc->intf->dev,
 140                                 "nonzero urb status received: -EPIPE\n");
 141                         break;
 142                 default:
 143                         dev_err(&desc->intf->dev,
 144                                 "Unexpected error %d\n", status);
 145                         break;
 146                 }
 147         }
 148
 149         desc->rerr = status;
 150         desc->reslength = urb->actual_length;
 151         memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
 152         desc->length += desc->reslength;
 153 skip_error:
 154         wake_up(&desc->wait);
 155
 156         set_bit(WDM_READ, &desc->flags);
 157         spin_unlock(&desc->iuspin);
 158 }
 159
 160 static void wdm_int_callback(struct urb *urb)
 161 {
 162         int rv = 0;
 163         int status = urb->status;
 164         struct wdm_device *desc;
 165         struct usb_ctrlrequest *req;
 166         struct usb_cdc_notification *dr;
 167
 168         desc = urb->context;
 169         req = desc->irq;
 170         dr = (struct usb_cdc_notification *)desc->sbuf;
 171
 172         if (status) {
 173                 switch (status) {
 174                 case -ESHUTDOWN:
 175                 case -ENOENT:
 176                 case -ECONNRESET:
 177                         return; /* unplug */
 178                 case -EPIPE:
 179                         set_bit(WDM_INT_STALL, &desc->flags);
 180                         dev_err(&desc->intf->dev, "Stall on int endpoint\n");
 181                         goto sw; /* halt is cleared in work */
 182                 default:
 183                         dev_err(&desc->intf->dev,
 184                                 "nonzero urb status received: %d\n", status);
 185                         break;
 186                 }
 187         }
 188
 189         if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
 190                 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
 191                         urb->actual_length);
 192                 goto exit;
 193         }
 194
 195         switch (dr->bNotificationType) {
 196         case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
 197                 dev_dbg(&desc->intf->dev,
 198                         "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
 199                         dr->wIndex, dr->wLength);
 200                 break;
 201
 202         case USB_CDC_NOTIFY_NETWORK_CONNECTION:
 203
 204                 dev_dbg(&desc->intf->dev,
 205                         "NOTIFY_NETWORK_CONNECTION %s network",
 206                         dr->wValue ? "connected to" : "disconnected from");
 207                 goto exit;
 208         default:
 209                 clear_bit(WDM_POLL_RUNNING, &desc->flags);
 210                 dev_err(&desc->intf->dev,
 211                         "unknown notification %d received: index %d len %d\n",
 212                         dr->bNotificationType, dr->wIndex, dr->wLength);
 213                 goto exit;
 214         }
 215
 216         req->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
 217         req->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
 218         req->wValue = 0;
 219         req->wIndex = desc->inum;
 220         req->wLength = cpu_to_le16(desc->wMaxCommand);
 221
 222         usb_fill_control_urb(
 223                 desc->response,
 224                 interface_to_usbdev(desc->intf),
 225                 /* using common endpoint 0 */
 226                 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
 227                 (unsigned char *)req,
 228                 desc->inbuf,
 229                 desc->wMaxCommand,
 230                 wdm_in_callback,
 231                 desc
 232         );
 233         desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 234         spin_lock(&desc->iuspin);
 235         clear_bit(WDM_READ, &desc->flags);
 236         set_bit(WDM_RESPONDING, &desc->flags);
 237         if (!test_bit(WDM_DISCONNECTING, &desc->flags)
 238                 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
 239                 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
 240                 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
 241                         __func__, rv);
 242         }
 243         spin_unlock(&desc->iuspin);
 244         if (rv < 0) {
 245                 clear_bit(WDM_RESPONDING, &desc->flags);
 246                 if (rv == -EPERM)
 247                         return;
 248                 if (rv == -ENOMEM) {
 249 sw:
 250                         rv = schedule_work(&desc->rxwork);
 251                         if (rv)
 252                                 dev_err(&desc->intf->dev,
 253                                         "Cannot schedule work\n");
 254                 }
 255         }
 256 exit:
 257         rv = usb_submit_urb(urb, GFP_ATOMIC);
 258         if (rv)
 259                 dev_err(&desc->intf->dev,
 260                         "%s - usb_submit_urb failed with result %d\n",
 261                         __func__, rv);
 262
 263 }
 264
 265 static void kill_urbs(struct wdm_device *desc)
 266 {
 267         /* the order here is essential */
 268         usb_kill_urb(desc->command);
 269         usb_kill_urb(desc->validity);
 270         usb_kill_urb(desc->response);
 271 }
 272
 273 static void free_urbs(struct wdm_device *desc)
 274 {
 275         usb_free_urb(desc->validity);
 276         usb_free_urb(desc->response);
 277         usb_free_urb(desc->command);
 278 }
 279
 280 static void cleanup(struct wdm_device *desc)
 281 {
 282         usb_free_coherent(interface_to_usbdev(desc->intf),
 283                           desc->wMaxPacketSize,
 284                           desc->sbuf,
 285                           desc->validity->transfer_dma);
 286         usb_free_coherent(interface_to_usbdev(desc->intf),
 287                           desc->bMaxPacketSize0,
 288                           desc->inbuf,
 289                           desc->response->transfer_dma);
 290         kfree(desc->orq);
 291         kfree(desc->irq);
 292         kfree(desc->ubuf);
 293         free_urbs(desc);
 294         kfree(desc);
 295 }
 296
 297 static ssize_t wdm_write
 298 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 299 {
 300         u8 *buf;
 301         int rv = -EMSGSIZE, r, we;
 302         struct wdm_device *desc = file->private_data;
 303         struct usb_ctrlrequest *req;
 304
 305         if (count > desc->wMaxCommand)
 306                 count = desc->wMaxCommand;
 307
 308         spin_lock_irq(&desc->iuspin);
 309         we = desc->werr;
 310         desc->werr = 0;
 311         spin_unlock_irq(&desc->iuspin);
 312         if (we < 0)
 313                 return -EIO;
 314
 315         desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
 316         if (!buf) {
 317                 rv = -ENOMEM;
 318                 goto outnl;
 319         }
 320
 321         r = copy_from_user(buf, buffer, count);
 322         if (r > 0) {
 323                 kfree(buf);
 324                 rv = -EFAULT;
 325                 goto outnl;
 326         }
 327
 328         /* concurrent writes and disconnect */
 329         r = mutex_lock_interruptible(&desc->wlock);
 330         rv = -ERESTARTSYS;
 331         if (r) {
 332                 kfree(buf);
 333                 goto outnl;
 334         }
 335
 336         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 337                 kfree(buf);
 338                 rv = -ENODEV;
 339                 goto outnp;
 340         }
 341
 342         r = usb_autopm_get_interface(desc->intf);
 343         if (r < 0) {
 344                 kfree(buf);
 345                 goto outnp;
 346         }
 347
 348         if (!(file->f_flags & O_NONBLOCK))
 349                 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
 350                                                                 &desc->flags));
 351         else
 352                 if (test_bit(WDM_IN_USE, &desc->flags))
 353                         r = -EAGAIN;
 354         if (r < 0) {
 355                 kfree(buf);
 356                 goto out;
 357         }
 358
 359         req = desc->orq;
 360         usb_fill_control_urb(
 361                 desc->command,
 362                 interface_to_usbdev(desc->intf),
 363                 /* using common endpoint 0 */
 364                 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
 365                 (unsigned char *)req,
 366                 buf,
 367                 count,
 368                 wdm_out_callback,
 369                 desc
 370         );
 371
 372         req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
 373                              USB_RECIP_INTERFACE);
 374         req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
 375         req->wValue = 0;
 376         req->wIndex = desc->inum;
 377         req->wLength = cpu_to_le16(count);
 378         set_bit(WDM_IN_USE, &desc->flags);
 379
 380         rv = usb_submit_urb(desc->command, GFP_KERNEL);
 381         if (rv < 0) {
 382                 kfree(buf);
 383                 clear_bit(WDM_IN_USE, &desc->flags);
 384                 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
 385         } else {
 386                 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
 387                         req->wIndex);
 388         }
 389 out:
 390         usb_autopm_put_interface(desc->intf);
 391 outnp:
 392         mutex_unlock(&desc->wlock);
 393 outnl:
 394         return rv < 0 ? rv : count;
 395 }
 396
 397 static ssize_t wdm_read
 398 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 399 {
 400         int rv, cntr;
 401         int i = 0;
 402         struct wdm_device *desc = file->private_data;
 403
 404
 405         rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
 406         if (rv < 0)
 407                 return -ERESTARTSYS;
 408
 409         cntr = ACCESS_ONCE(desc->length);
 410         if (cntr == 0) {
 411                 desc->read = 0;
 412 retry:
 413                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 414                         rv = -ENODEV;
 415                         goto err;
 416                 }
 417                 i++;
 418                 if (file->f_flags & O_NONBLOCK) {
 419                         if (!test_bit(WDM_READ, &desc->flags)) {
 420                                 rv = cntr ? cntr : -EAGAIN;
 421                                 goto err;
 422                         }
 423                         rv = 0;
 424                 } else {
 425                         rv = wait_event_interruptible(desc->wait,
 426                                 test_bit(WDM_READ, &desc->flags));
 427                 }
 428
 429                 /* may have happened while we slept */
 430                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 431                         rv = -ENODEV;
 432                         goto err;
 433                 }
 434                 usb_mark_last_busy(interface_to_usbdev(desc->intf));
 435                 if (rv < 0) {
 436                         rv = -ERESTARTSYS;
 437                         goto err;
 438                 }
 439
 440                 spin_lock_irq(&desc->iuspin);
 441
 442                 if (desc->rerr) { /* read completed, error happened */
 443                         desc->rerr = 0;
 444                         spin_unlock_irq(&desc->iuspin);
 445                         rv = -EIO;
 446                         goto err;
 447                 }
 448                 /*
 449                  * recheck whether we've lost the race
 450                  * against the completion handler
 451                  */
 452                 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
 453                         spin_unlock_irq(&desc->iuspin);
 454                         goto retry;
 455                 }
 456                 if (!desc->reslength) { /* zero length read */
 457                         spin_unlock_irq(&desc->iuspin);
 458                         goto retry;
 459                 }
 460                 clear_bit(WDM_READ, &desc->flags);
 461                 cntr = desc->length;
 462                 spin_unlock_irq(&desc->iuspin);
 463         }
 464
 465         if (cntr > count)
 466                 cntr = count;
 467         rv = copy_to_user(buffer, desc->ubuf, cntr);
 468         if (rv > 0) {
 469                 rv = -EFAULT;
 470                 goto err;
 471         }
 472
 473         spin_lock_irq(&desc->iuspin);
 474
 475         for (i = 0; i < desc->length - cntr; i++)
 476                 desc->ubuf[i] = desc->ubuf[i + cntr];
 477
 478         desc->length -= cntr;
 479         /* in case we had outstanding data */
 480         if (!desc->length)
 481                 clear_bit(WDM_READ, &desc->flags);
 482
 483         spin_unlock_irq(&desc->iuspin);
 484
 485         rv = cntr;
 486
 487 err:
 488         mutex_unlock(&desc->rlock);
 489         return rv;
 490 }
 491
 492 static int wdm_flush(struct file *file, fl_owner_t id)
 493 {
 494         struct wdm_device *desc = file->private_data;
 495
 496         wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
 497         if (desc->werr < 0)
 498                 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
 499                         desc->werr);
 500
 501         return desc->werr;
 502 }
 503
 504 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
 505 {
 506         struct wdm_device *desc = file->private_data;
 507         unsigned long flags;
 508         unsigned int mask = 0;
 509
 510         spin_lock_irqsave(&desc->iuspin, flags);
 511         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 512                 mask = POLLERR;
 513                 spin_unlock_irqrestore(&desc->iuspin, flags);
 514                 goto desc_out;
 515         }
 516         if (test_bit(WDM_READ, &desc->flags))
 517                 mask = POLLIN | POLLRDNORM;
 518         if (desc->rerr || desc->werr)
 519                 mask |= POLLERR;
 520         if (!test_bit(WDM_IN_USE, &desc->flags))
 521                 mask |= POLLOUT | POLLWRNORM;
 522         spin_unlock_irqrestore(&desc->iuspin, flags);
 523
 524         poll_wait(file, &desc->wait, wait);
 525
 526 desc_out:
 527         return mask;
 528 }
 529
 530 static int wdm_open(struct inode *inode, struct file *file)
 531 {
 532         int minor = iminor(inode);
 533         int rv = -ENODEV;
 534         struct usb_interface *intf;
 535         struct wdm_device *desc;
 536
 537         mutex_lock(&wdm_mutex);
 538         intf = usb_find_interface(&wdm_driver, minor);
 539         if (!intf)
 540                 goto out;
 541
 542         desc = usb_get_intfdata(intf);
 543         if (test_bit(WDM_DISCONNECTING, &desc->flags))
 544                 goto out;
 545         file->private_data = desc;
 546
 547         rv = usb_autopm_get_interface(desc->intf);
 548         if (rv < 0) {
 549                 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
 550                 goto out;
 551         }
 552         intf->needs_remote_wakeup = 1;
 553
 554         /* using write lock to protect desc->count */
 555         mutex_lock(&desc->wlock);
 556         if (!desc->count++) {
 557                 desc->werr = 0;
 558                 desc->rerr = 0;
 559                 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
 560                 if (rv < 0) {
 561                         desc->count--;
 562                         dev_err(&desc->intf->dev,
 563                                 "Error submitting int urb - %d\n", rv);
 564                 }
 565         } else {
 566                 rv = 0;
 567         }
 568         mutex_unlock(&desc->wlock);
 569         usb_autopm_put_interface(desc->intf);
 570 out:
 571         mutex_unlock(&wdm_mutex);
 572         return rv;
 573 }
 574
 575 static int wdm_release(struct inode *inode, struct file *file)
 576 {
 577         struct wdm_device *desc = file->private_data;
 578
 579         mutex_lock(&wdm_mutex);
 580
 581         /* using write lock to protect desc->count */
 582         mutex_lock(&desc->wlock);
 583         desc->count--;
 584         mutex_unlock(&desc->wlock);
 585
 586         if (!desc->count) {
 587                 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
 588                 kill_urbs(desc);
 589                 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 590                         desc->intf->needs_remote_wakeup = 0;
 591         }
 592         mutex_unlock(&wdm_mutex);
 593         return 0;
 594 }
 595
 596 static const struct file_operations wdm_fops = {
 597         .owner =        THIS_MODULE,
 598         .read =         wdm_read,
 599         .write =        wdm_write,
 600         .open =         wdm_open,
 601         .flush =        wdm_flush,
 602         .release =      wdm_release,
 603         .poll =         wdm_poll,
 604         .llseek =       noop_llseek,
 605 };
 606
 607 static struct usb_class_driver wdm_class = {
 608         .name =         "cdc-wdm%d",
 609         .fops =         &wdm_fops,
 610         .minor_base =   WDM_MINOR_BASE,
 611 };
 612
 613 /* --- error handling --- */
 614 static void wdm_rxwork(struct work_struct *work)
 615 {
 616         struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
 617         unsigned long flags;
 618         int rv;
 619
 620         spin_lock_irqsave(&desc->iuspin, flags);
 621         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 622                 spin_unlock_irqrestore(&desc->iuspin, flags);
 623         } else {
 624                 spin_unlock_irqrestore(&desc->iuspin, flags);
 625                 rv = usb_submit_urb(desc->response, GFP_KERNEL);
 626                 if (rv < 0 && rv != -EPERM) {
 627                         spin_lock_irqsave(&desc->iuspin, flags);
 628                         if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 629                                 schedule_work(&desc->rxwork);
 630                         spin_unlock_irqrestore(&desc->iuspin, flags);
 631                 }
 632         }
 633 }
 634
 635 /* --- hotplug --- */
 636
 637 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
 638 {
 639         int rv = -EINVAL;
 640         struct usb_device *udev = interface_to_usbdev(intf);
 641         struct wdm_device *desc;
 642         struct usb_host_interface *iface;
 643         struct usb_endpoint_descriptor *ep;
 644         struct usb_cdc_dmm_desc *dmhd;
 645         u8 *buffer = intf->altsetting->extra;
 646         int buflen = intf->altsetting->extralen;
 647         u16 maxcom = WDM_DEFAULT_BUFSIZE;
 648
 649         if (!buffer)
 650                 goto out;
 651
 652         while (buflen > 2) {
 653                 if (buffer [1] != USB_DT_CS_INTERFACE) {
 654                         dev_err(&intf->dev, "skipping garbage\n");
 655                         goto next_desc;
 656                 }
 657
 658                 switch (buffer [2]) {
 659                 case USB_CDC_HEADER_TYPE:
 660                         break;
 661                 case USB_CDC_DMM_TYPE:
 662                         dmhd = (struct usb_cdc_dmm_desc *)buffer;
 663                         maxcom = le16_to_cpu(dmhd->wMaxCommand);
 664                         dev_dbg(&intf->dev,
 665                                 "Finding maximum buffer length: %d", maxcom);
 666                         break;
 667                 default:
 668                         dev_err(&intf->dev,
 669                                 "Ignoring extra header, type %d, length %d\n",
 670                                 buffer[2], buffer[0]);
 671                         break;
 672                 }
 673 next_desc:
 674                 buflen -= buffer[0];
 675                 buffer += buffer[0];
 676         }
 677
 678         rv = -ENOMEM;
 679         desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
 680         if (!desc)
 681                 goto out;
 682         mutex_init(&desc->rlock);
 683         mutex_init(&desc->wlock);
 684         spin_lock_init(&desc->iuspin);
 685         init_waitqueue_head(&desc->wait);
 686         desc->wMaxCommand = maxcom;
 687         /* this will be expanded and needed in hardware endianness */
 688         desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
 689         desc->intf = intf;
 690         INIT_WORK(&desc->rxwork, wdm_rxwork);
 691
 692         rv = -EINVAL;
 693         iface = intf->cur_altsetting;
 694         if (iface->desc.bNumEndpoints != 1)
 695                 goto err;
 696         ep = &iface->endpoint[0].desc;
 697         if (!ep || !usb_endpoint_is_int_in(ep))
 698                 goto err;
 699
 700         desc->wMaxPacketSize = usb_endpoint_maxp(ep);
 701         desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0;
 702
 703         desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 704         if (!desc->orq)
 705                 goto err;
 706         desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 707         if (!desc->irq)
 708                 goto err;
 709
 710         desc->validity = usb_alloc_urb(0, GFP_KERNEL);
 711         if (!desc->validity)
 712                 goto err;
 713
 714         desc->response = usb_alloc_urb(0, GFP_KERNEL);
 715         if (!desc->response)
 716                 goto err;
 717
 718         desc->command = usb_alloc_urb(0, GFP_KERNEL);
 719         if (!desc->command)
 720                 goto err;
 721
 722         desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
 723         if (!desc->ubuf)
 724                 goto err;
 725
 726         desc->sbuf = usb_alloc_coherent(interface_to_usbdev(intf),
 727                                         desc->wMaxPacketSize,
 728                                         GFP_KERNEL,
 729                                         &desc->validity->transfer_dma);
 730         if (!desc->sbuf)
 731                 goto err;
 732
 733         desc->inbuf = usb_alloc_coherent(interface_to_usbdev(intf),
 734                                          desc->wMaxCommand,
 735                                          GFP_KERNEL,
 736                                          &desc->response->transfer_dma);
 737         if (!desc->inbuf)
 738                 goto err2;
 739
 740         usb_fill_int_urb(
 741                 desc->validity,
 742                 interface_to_usbdev(intf),
 743                 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
 744                 desc->sbuf,
 745                 desc->wMaxPacketSize,
 746                 wdm_int_callback,
 747                 desc,
 748                 ep->bInterval
 749         );
 750         desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 751
 752         usb_set_intfdata(intf, desc);
 753         rv = usb_register_dev(intf, &wdm_class);
 754         if (rv < 0)
 755                 goto err3;
 756         else
 757                 dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
 758                         intf->minor - WDM_MINOR_BASE);
 759 out:
 760         return rv;
 761 err3:
 762         usb_set_intfdata(intf, NULL);
 763         usb_free_coherent(interface_to_usbdev(desc->intf),
 764                           desc->bMaxPacketSize0,
 765                         desc->inbuf,
 766                         desc->response->transfer_dma);
 767 err2:
 768         usb_free_coherent(interface_to_usbdev(desc->intf),
 769                           desc->wMaxPacketSize,
 770                           desc->sbuf,
 771                           desc->validity->transfer_dma);
 772 err:
 773         free_urbs(desc);
 774         kfree(desc->ubuf);
 775         kfree(desc->orq);
 776         kfree(desc->irq);
 777         kfree(desc);
 778         return rv;
 779 }
 780
 781 static void wdm_disconnect(struct usb_interface *intf)
 782 {
 783         struct wdm_device *desc;
 784         unsigned long flags;
 785
 786         usb_deregister_dev(intf, &wdm_class);
 787         mutex_lock(&wdm_mutex);
 788         desc = usb_get_intfdata(intf);
 789
 790         /* the spinlock makes sure no new urbs are generated in the callbacks */
 791         spin_lock_irqsave(&desc->iuspin, flags);
 792         set_bit(WDM_DISCONNECTING, &desc->flags);
 793         set_bit(WDM_READ, &desc->flags);
 794         /* to terminate pending flushes */
 795         clear_bit(WDM_IN_USE, &desc->flags);
 796         spin_unlock_irqrestore(&desc->iuspin, flags);
 797         wake_up_all(&desc->wait);
 798         mutex_lock(&desc->rlock);
 799         mutex_lock(&desc->wlock);
 800         kill_urbs(desc);
 801         cancel_work_sync(&desc->rxwork);
 802         mutex_unlock(&desc->wlock);
 803         mutex_unlock(&desc->rlock);
 804         if (!desc->count)
 805                 cleanup(desc);
 806         mutex_unlock(&wdm_mutex);
 807 }
 808
 809 #ifdef CONFIG_PM
 810 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
 811 {
 812         struct wdm_device *desc = usb_get_intfdata(intf);
 813         int rv = 0;
 814
 815         dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
 816
 817         /* if this is an autosuspend the caller does the locking */
 818         if (!PMSG_IS_AUTO(message)) {
 819                 mutex_lock(&desc->rlock);
 820                 mutex_lock(&desc->wlock);
 821         }
 822         spin_lock_irq(&desc->iuspin);
 823
 824         if (PMSG_IS_AUTO(message) &&
 825                         (test_bit(WDM_IN_USE, &desc->flags)
 826                         || test_bit(WDM_RESPONDING, &desc->flags))) {
 827                 spin_unlock_irq(&desc->iuspin);
 828                 rv = -EBUSY;
 829         } else {
 830
 831                 set_bit(WDM_SUSPENDING, &desc->flags);
 832                 spin_unlock_irq(&desc->iuspin);
 833                 /* callback submits work - order is essential */
 834                 kill_urbs(desc);
 835                 cancel_work_sync(&desc->rxwork);
 836         }
 837         if (!PMSG_IS_AUTO(message)) {
 838                 mutex_unlock(&desc->wlock);
 839                 mutex_unlock(&desc->rlock);
 840         }
 841
 842         return rv;
 843 }
 844 #endif
 845
 846 static int recover_from_urb_loss(struct wdm_device *desc)
 847 {
 848         int rv = 0;
 849
 850         if (desc->count) {
 851                 rv = usb_submit_urb(desc->validity, GFP_NOIO);
 852                 if (rv < 0)
 853                         dev_err(&desc->intf->dev,
 854                                 "Error resume submitting int urb - %d\n", rv);
 855         }
 856         return rv;
 857 }
 858
 859 #ifdef CONFIG_PM
 860 static int wdm_resume(struct usb_interface *intf)
 861 {
 862         struct wdm_device *desc = usb_get_intfdata(intf);
 863         int rv;
 864
 865         dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
 866
 867         clear_bit(WDM_SUSPENDING, &desc->flags);
 868         rv = recover_from_urb_loss(desc);
 869
 870         return rv;
 871 }
 872 #endif
 873
 874 static int wdm_pre_reset(struct usb_interface *intf)
 875 {
 876         struct wdm_device *desc = usb_get_intfdata(intf);
 877
 878         mutex_lock(&desc->rlock);
 879         mutex_lock(&desc->wlock);
 880         kill_urbs(desc);
 881
 882         /*
 883          * we notify everybody using poll of
 884          * an exceptional situation
 885          * must be done before recovery lest a spontaneous
 886          * message from the device is lost
 887          */
 888         spin_lock_irq(&desc->iuspin);
 889         desc->rerr = -EINTR;
 890         spin_unlock_irq(&desc->iuspin);
 891         wake_up_all(&desc->wait);
 892         return 0;
 893 }
 894
 895 static int wdm_post_reset(struct usb_interface *intf)
 896 {
 897         struct wdm_device *desc = usb_get_intfdata(intf);
 898         int rv;
 899
 900         rv = recover_from_urb_loss(desc);
 901         mutex_unlock(&desc->wlock);
 902         mutex_unlock(&desc->rlock);
 903         return 0;
 904 }
 905
 906 static struct usb_driver wdm_driver = {
 907         .name =         "cdc_wdm",
 908         .probe =        wdm_probe,
 909         .disconnect =   wdm_disconnect,
 910 #ifdef CONFIG_PM
 911         .suspend =      wdm_suspend,
 912         .resume =       wdm_resume,
 913         .reset_resume = wdm_resume,
 914 #endif
 915         .pre_reset =    wdm_pre_reset,
 916         .post_reset =   wdm_post_reset,
 917         .id_table =     wdm_ids,
 918         .supports_autosuspend = 1,
 919 };
 920
 921 /* --- low level module stuff --- */
 922
 923 static int __init wdm_init(void)
 924 {
 925         int rv;
 926
 927         rv = usb_register(&wdm_driver);
 928
 929         return rv;
 930 }
 931
 932 static void __exit wdm_exit(void)
 933 {
 934         usb_deregister(&wdm_driver);
 935 }
 936
 937 module_init(wdm_init);
 938 module_exit(wdm_exit);
 939
 940 MODULE_AUTHOR(DRIVER_AUTHOR);
 941 MODULE_DESCRIPTION(DRIVER_DESC);
 942 MODULE_LICENSE("GPL");