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