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 #define WDM_RESETTING           9
  74
  75 #define WDM_MAX                 16
  76
  77 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
  78 #define WDM_DEFAULT_BUFSIZE     256
  79
  80 static DEFINE_MUTEX(wdm_mutex);
  81 static DEFINE_SPINLOCK(wdm_device_list_lock);
  82 static LIST_HEAD(wdm_device_list);
  83
  84 /* --- method tables --- */
  85
  86 struct wdm_device {
  87         u8                      *inbuf; /* buffer for response */
  88         u8                      *outbuf; /* buffer for command */
  89         u8                      *sbuf; /* buffer for status */
  90         u8                      *ubuf; /* buffer for copy to user space */
  91
  92         struct urb              *command;
  93         struct urb              *response;
  94         struct urb              *validity;
  95         struct usb_interface    *intf;
  96         struct usb_ctrlrequest  *orq;
  97         struct usb_ctrlrequest  *irq;
  98         spinlock_t              iuspin;
  99
 100         unsigned long           flags;
 101         u16                     bufsize;
 102         u16                     wMaxCommand;
 103         u16                     wMaxPacketSize;
 104         __le16                  inum;
 105         int                     reslength;
 106         int                     length;
 107         int                     read;
 108         int                     count;
 109         dma_addr_t              shandle;
 110         dma_addr_t              ihandle;
 111         struct mutex            wlock;
 112         struct mutex            rlock;
 113         wait_queue_head_t       wait;
 114         struct work_struct      rxwork;
 115         int                     werr;
 116         int                     rerr;
 117
 118         struct list_head        device_list;
 119 };
 120
 121 static struct usb_driver wdm_driver;
 122
 123 /* return intfdata if we own the interface, else look up intf in the list */
 124 static struct wdm_device *wdm_find_device(struct usb_interface *intf)
 125 {
 126         struct wdm_device *desc = NULL;
 127
 128         spin_lock(&wdm_device_list_lock);
 129         list_for_each_entry(desc, &wdm_device_list, device_list)
 130                 if (desc->intf == intf)
 131                         break;
 132         spin_unlock(&wdm_device_list_lock);
 133
 134         return desc;
 135 }
 136
 137 static struct wdm_device *wdm_find_device_by_minor(int minor)
 138 {
 139         struct wdm_device *desc = NULL;
 140
 141         spin_lock(&wdm_device_list_lock);
 142         list_for_each_entry(desc, &wdm_device_list, device_list)
 143                 if (desc->intf->minor == minor)
 144                         break;
 145         spin_unlock(&wdm_device_list_lock);
 146
 147         return desc;
 148 }
 149
 150 /* --- callbacks --- */
 151 static void wdm_out_callback(struct urb *urb)
 152 {
 153         struct wdm_device *desc;
 154         desc = urb->context;
 155         spin_lock(&desc->iuspin);
 156         desc->werr = urb->status;
 157         spin_unlock(&desc->iuspin);
 158         clear_bit(WDM_IN_USE, &desc->flags);
 159         kfree(desc->outbuf);
 160         wake_up(&desc->wait);
 161 }
 162
 163 static void wdm_in_callback(struct urb *urb)
 164 {
 165         struct wdm_device *desc = urb->context;
 166         int status = urb->status;
 167
 168         spin_lock(&desc->iuspin);
 169         clear_bit(WDM_RESPONDING, &desc->flags);
 170
 171         if (status) {
 172                 switch (status) {
 173                 case -ENOENT:
 174                         dev_dbg(&desc->intf->dev,
 175                                 "nonzero urb status received: -ENOENT");
 176                         goto skip_error;
 177                 case -ECONNRESET:
 178                         dev_dbg(&desc->intf->dev,
 179                                 "nonzero urb status received: -ECONNRESET");
 180                         goto skip_error;
 181                 case -ESHUTDOWN:
 182                         dev_dbg(&desc->intf->dev,
 183                                 "nonzero urb status received: -ESHUTDOWN");
 184                         goto skip_error;
 185                 case -EPIPE:
 186                         dev_err(&desc->intf->dev,
 187                                 "nonzero urb status received: -EPIPE\n");
 188                         break;
 189                 default:
 190                         dev_err(&desc->intf->dev,
 191                                 "Unexpected error %d\n", status);
 192                         break;
 193                 }
 194         }
 195
 196         desc->rerr = status;
 197         desc->reslength = urb->actual_length;
 198         memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
 199         desc->length += desc->reslength;
 200 skip_error:
 201         wake_up(&desc->wait);
 202
 203         set_bit(WDM_READ, &desc->flags);
 204         spin_unlock(&desc->iuspin);
 205 }
 206
 207 static void wdm_int_callback(struct urb *urb)
 208 {
 209         int rv = 0;
 210         int status = urb->status;
 211         struct wdm_device *desc;
 212         struct usb_cdc_notification *dr;
 213
 214         desc = urb->context;
 215         dr = (struct usb_cdc_notification *)desc->sbuf;
 216
 217         if (status) {
 218                 switch (status) {
 219                 case -ESHUTDOWN:
 220                 case -ENOENT:
 221                 case -ECONNRESET:
 222                         return; /* unplug */
 223                 case -EPIPE:
 224                         set_bit(WDM_INT_STALL, &desc->flags);
 225                         dev_err(&desc->intf->dev, "Stall on int endpoint\n");
 226                         goto sw; /* halt is cleared in work */
 227                 default:
 228                         dev_err(&desc->intf->dev,
 229                                 "nonzero urb status received: %d\n", status);
 230                         break;
 231                 }
 232         }
 233
 234         if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
 235                 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
 236                         urb->actual_length);
 237                 goto exit;
 238         }
 239
 240         switch (dr->bNotificationType) {
 241         case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
 242                 dev_dbg(&desc->intf->dev,
 243                         "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
 244                         dr->wIndex, dr->wLength);
 245                 break;
 246
 247         case USB_CDC_NOTIFY_NETWORK_CONNECTION:
 248
 249                 dev_dbg(&desc->intf->dev,
 250                         "NOTIFY_NETWORK_CONNECTION %s network",
 251                         dr->wValue ? "connected to" : "disconnected from");
 252                 goto exit;
 253         default:
 254                 clear_bit(WDM_POLL_RUNNING, &desc->flags);
 255                 dev_err(&desc->intf->dev,
 256                         "unknown notification %d received: index %d len %d\n",
 257                         dr->bNotificationType, dr->wIndex, dr->wLength);
 258                 goto exit;
 259         }
 260
 261         spin_lock(&desc->iuspin);
 262         clear_bit(WDM_READ, &desc->flags);
 263         set_bit(WDM_RESPONDING, &desc->flags);
 264         if (!test_bit(WDM_DISCONNECTING, &desc->flags)
 265                 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
 266                 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
 267                 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
 268                         __func__, rv);
 269         }
 270         spin_unlock(&desc->iuspin);
 271         if (rv < 0) {
 272                 clear_bit(WDM_RESPONDING, &desc->flags);
 273                 if (rv == -EPERM)
 274                         return;
 275                 if (rv == -ENOMEM) {
 276 sw:
 277                         rv = schedule_work(&desc->rxwork);
 278                         if (rv)
 279                                 dev_err(&desc->intf->dev,
 280                                         "Cannot schedule work\n");
 281                 }
 282         }
 283 exit:
 284         rv = usb_submit_urb(urb, GFP_ATOMIC);
 285         if (rv)
 286                 dev_err(&desc->intf->dev,
 287                         "%s - usb_submit_urb failed with result %d\n",
 288                         __func__, rv);
 289
 290 }
 291
 292 static void kill_urbs(struct wdm_device *desc)
 293 {
 294         /* the order here is essential */
 295         usb_kill_urb(desc->command);
 296         usb_kill_urb(desc->validity);
 297         usb_kill_urb(desc->response);
 298 }
 299
 300 static void free_urbs(struct wdm_device *desc)
 301 {
 302         usb_free_urb(desc->validity);
 303         usb_free_urb(desc->response);
 304         usb_free_urb(desc->command);
 305 }
 306
 307 static void cleanup(struct wdm_device *desc)
 308 {
 309         spin_lock(&wdm_device_list_lock);
 310         list_del(&desc->device_list);
 311         spin_unlock(&wdm_device_list_lock);
 312         kfree(desc->sbuf);
 313         kfree(desc->inbuf);
 314         kfree(desc->orq);
 315         kfree(desc->irq);
 316         kfree(desc->ubuf);
 317         free_urbs(desc);
 318         kfree(desc);
 319 }
 320
 321 static ssize_t wdm_write
 322 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 323 {
 324         u8 *buf;
 325         int rv = -EMSGSIZE, r, we;
 326         struct wdm_device *desc = file->private_data;
 327         struct usb_ctrlrequest *req;
 328
 329         if (count > desc->wMaxCommand)
 330                 count = desc->wMaxCommand;
 331
 332         spin_lock_irq(&desc->iuspin);
 333         we = desc->werr;
 334         desc->werr = 0;
 335         spin_unlock_irq(&desc->iuspin);
 336         if (we < 0)
 337                 return -EIO;
 338
 339         desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
 340         if (!buf) {
 341                 rv = -ENOMEM;
 342                 goto outnl;
 343         }
 344
 345         r = copy_from_user(buf, buffer, count);
 346         if (r > 0) {
 347                 kfree(buf);
 348                 rv = -EFAULT;
 349                 goto outnl;
 350         }
 351
 352         /* concurrent writes and disconnect */
 353         r = mutex_lock_interruptible(&desc->wlock);
 354         rv = -ERESTARTSYS;
 355         if (r) {
 356                 kfree(buf);
 357                 goto outnl;
 358         }
 359
 360         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 361                 kfree(buf);
 362                 rv = -ENODEV;
 363                 goto outnp;
 364         }
 365
 366         r = usb_autopm_get_interface(desc->intf);
 367         if (r < 0) {
 368                 kfree(buf);
 369                 goto outnp;
 370         }
 371
 372         if (!(file->f_flags & O_NONBLOCK))
 373                 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
 374                                                                 &desc->flags));
 375         else
 376                 if (test_bit(WDM_IN_USE, &desc->flags))
 377                         r = -EAGAIN;
 378
 379         if (test_bit(WDM_RESETTING, &desc->flags))
 380                 r = -EIO;
 381
 382         if (r < 0) {
 383                 kfree(buf);
 384                 goto out;
 385         }
 386
 387         req = desc->orq;
 388         usb_fill_control_urb(
 389                 desc->command,
 390                 interface_to_usbdev(desc->intf),
 391                 /* using common endpoint 0 */
 392                 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
 393                 (unsigned char *)req,
 394                 buf,
 395                 count,
 396                 wdm_out_callback,
 397                 desc
 398         );
 399
 400         req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
 401                              USB_RECIP_INTERFACE);
 402         req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
 403         req->wValue = 0;
 404         req->wIndex = desc->inum;
 405         req->wLength = cpu_to_le16(count);
 406         set_bit(WDM_IN_USE, &desc->flags);
 407
 408         rv = usb_submit_urb(desc->command, GFP_KERNEL);
 409         if (rv < 0) {
 410                 kfree(buf);
 411                 clear_bit(WDM_IN_USE, &desc->flags);
 412                 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
 413         } else {
 414                 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
 415                         req->wIndex);
 416         }
 417 out:
 418         usb_autopm_put_interface(desc->intf);
 419 outnp:
 420         mutex_unlock(&desc->wlock);
 421 outnl:
 422         return rv < 0 ? rv : count;
 423 }
 424
 425 static ssize_t wdm_read
 426 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 427 {
 428         int rv, cntr;
 429         int i = 0;
 430         struct wdm_device *desc = file->private_data;
 431
 432
 433         rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
 434         if (rv < 0)
 435                 return -ERESTARTSYS;
 436
 437         cntr = ACCESS_ONCE(desc->length);
 438         if (cntr == 0) {
 439                 desc->read = 0;
 440 retry:
 441                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 442                         rv = -ENODEV;
 443                         goto err;
 444                 }
 445                 i++;
 446                 if (file->f_flags & O_NONBLOCK) {
 447                         if (!test_bit(WDM_READ, &desc->flags)) {
 448                                 rv = cntr ? cntr : -EAGAIN;
 449                                 goto err;
 450                         }
 451                         rv = 0;
 452                 } else {
 453                         rv = wait_event_interruptible(desc->wait,
 454                                 test_bit(WDM_READ, &desc->flags));
 455                 }
 456
 457                 /* may have happened while we slept */
 458                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 459                         rv = -ENODEV;
 460                         goto err;
 461                 }
 462                 if (test_bit(WDM_RESETTING, &desc->flags)) {
 463                         rv = -EIO;
 464                         goto err;
 465                 }
 466                 usb_mark_last_busy(interface_to_usbdev(desc->intf));
 467                 if (rv < 0) {
 468                         rv = -ERESTARTSYS;
 469                         goto err;
 470                 }
 471
 472                 spin_lock_irq(&desc->iuspin);
 473
 474                 if (desc->rerr) { /* read completed, error happened */
 475                         desc->rerr = 0;
 476                         spin_unlock_irq(&desc->iuspin);
 477                         rv = -EIO;
 478                         goto err;
 479                 }
 480                 /*
 481                  * recheck whether we've lost the race
 482                  * against the completion handler
 483                  */
 484                 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
 485                         spin_unlock_irq(&desc->iuspin);
 486                         goto retry;
 487                 }
 488                 if (!desc->reslength) { /* zero length read */
 489                         spin_unlock_irq(&desc->iuspin);
 490                         goto retry;
 491                 }
 492                 cntr = desc->length;
 493                 spin_unlock_irq(&desc->iuspin);
 494         }
 495
 496         if (cntr > count)
 497                 cntr = count;
 498         rv = copy_to_user(buffer, desc->ubuf, cntr);
 499         if (rv > 0) {
 500                 rv = -EFAULT;
 501                 goto err;
 502         }
 503
 504         spin_lock_irq(&desc->iuspin);
 505
 506         for (i = 0; i < desc->length - cntr; i++)
 507                 desc->ubuf[i] = desc->ubuf[i + cntr];
 508
 509         desc->length -= cntr;
 510         /* in case we had outstanding data */
 511         if (!desc->length)
 512                 clear_bit(WDM_READ, &desc->flags);
 513
 514         spin_unlock_irq(&desc->iuspin);
 515
 516         rv = cntr;
 517
 518 err:
 519         mutex_unlock(&desc->rlock);
 520         return rv;
 521 }
 522
 523 static int wdm_flush(struct file *file, fl_owner_t id)
 524 {
 525         struct wdm_device *desc = file->private_data;
 526
 527         wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
 528         if (desc->werr < 0)
 529                 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
 530                         desc->werr);
 531
 532         return desc->werr;
 533 }
 534
 535 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
 536 {
 537         struct wdm_device *desc = file->private_data;
 538         unsigned long flags;
 539         unsigned int mask = 0;
 540
 541         spin_lock_irqsave(&desc->iuspin, flags);
 542         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 543                 mask = POLLERR;
 544                 spin_unlock_irqrestore(&desc->iuspin, flags);
 545                 goto desc_out;
 546         }
 547         if (test_bit(WDM_READ, &desc->flags))
 548                 mask = POLLIN | POLLRDNORM;
 549         if (desc->rerr || desc->werr)
 550                 mask |= POLLERR;
 551         if (!test_bit(WDM_IN_USE, &desc->flags))
 552                 mask |= POLLOUT | POLLWRNORM;
 553         spin_unlock_irqrestore(&desc->iuspin, flags);
 554
 555         poll_wait(file, &desc->wait, wait);
 556
 557 desc_out:
 558         return mask;
 559 }
 560
 561 static int wdm_open(struct inode *inode, struct file *file)
 562 {
 563         int minor = iminor(inode);
 564         int rv = -ENODEV;
 565         struct usb_interface *intf;
 566         struct wdm_device *desc;
 567
 568         mutex_lock(&wdm_mutex);
 569         desc = wdm_find_device_by_minor(minor);
 570         if (!desc)
 571                 goto out;
 572
 573         intf = desc->intf;
 574         if (test_bit(WDM_DISCONNECTING, &desc->flags))
 575                 goto out;
 576         file->private_data = desc;
 577
 578         rv = usb_autopm_get_interface(desc->intf);
 579         if (rv < 0) {
 580                 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
 581                 goto out;
 582         }
 583         intf->needs_remote_wakeup = 1;
 584
 585         /* using write lock to protect desc->count */
 586         mutex_lock(&desc->wlock);
 587         if (!desc->count++) {
 588                 desc->werr = 0;
 589                 desc->rerr = 0;
 590                 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
 591                 if (rv < 0) {
 592                         desc->count--;
 593                         dev_err(&desc->intf->dev,
 594                                 "Error submitting int urb - %d\n", rv);
 595                 }
 596         } else {
 597                 rv = 0;
 598         }
 599         mutex_unlock(&desc->wlock);
 600         usb_autopm_put_interface(desc->intf);
 601 out:
 602         mutex_unlock(&wdm_mutex);
 603         return rv;
 604 }
 605
 606 static int wdm_release(struct inode *inode, struct file *file)
 607 {
 608         struct wdm_device *desc = file->private_data;
 609
 610         mutex_lock(&wdm_mutex);
 611
 612         /* using write lock to protect desc->count */
 613         mutex_lock(&desc->wlock);
 614         desc->count--;
 615         mutex_unlock(&desc->wlock);
 616
 617         if (!desc->count) {
 618                 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
 619                 kill_urbs(desc);
 620                 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 621                         desc->intf->needs_remote_wakeup = 0;
 622         }
 623         mutex_unlock(&wdm_mutex);
 624         return 0;
 625 }
 626
 627 static const struct file_operations wdm_fops = {
 628         .owner =        THIS_MODULE,
 629         .read =         wdm_read,
 630         .write =        wdm_write,
 631         .open =         wdm_open,
 632         .flush =        wdm_flush,
 633         .release =      wdm_release,
 634         .poll =         wdm_poll,
 635         .llseek =       noop_llseek,
 636 };
 637
 638 static struct usb_class_driver wdm_class = {
 639         .name =         "cdc-wdm%d",
 640         .fops =         &wdm_fops,
 641         .minor_base =   WDM_MINOR_BASE,
 642 };
 643
 644 /* --- error handling --- */
 645 static void wdm_rxwork(struct work_struct *work)
 646 {
 647         struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
 648         unsigned long flags;
 649         int rv;
 650
 651         spin_lock_irqsave(&desc->iuspin, flags);
 652         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 653                 spin_unlock_irqrestore(&desc->iuspin, flags);
 654         } else {
 655                 spin_unlock_irqrestore(&desc->iuspin, flags);
 656                 rv = usb_submit_urb(desc->response, GFP_KERNEL);
 657                 if (rv < 0 && rv != -EPERM) {
 658                         spin_lock_irqsave(&desc->iuspin, flags);
 659                         if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 660                                 schedule_work(&desc->rxwork);
 661                         spin_unlock_irqrestore(&desc->iuspin, flags);
 662                 }
 663         }
 664 }
 665
 666 /* --- hotplug --- */
 667
 668 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep, u16 bufsize)
 669 {
 670         int rv = -ENOMEM;
 671         struct wdm_device *desc;
 672
 673         desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
 674         if (!desc)
 675                 goto out;
 676         INIT_LIST_HEAD(&desc->device_list);
 677         mutex_init(&desc->rlock);
 678         mutex_init(&desc->wlock);
 679         spin_lock_init(&desc->iuspin);
 680         init_waitqueue_head(&desc->wait);
 681         desc->wMaxCommand = bufsize;
 682         /* this will be expanded and needed in hardware endianness */
 683         desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
 684         desc->intf = intf;
 685         INIT_WORK(&desc->rxwork, wdm_rxwork);
 686
 687         rv = -EINVAL;
 688         if (!usb_endpoint_is_int_in(ep))
 689                 goto err;
 690
 691         desc->wMaxPacketSize = usb_endpoint_maxp(ep);
 692
 693         desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 694         if (!desc->orq)
 695                 goto err;
 696         desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 697         if (!desc->irq)
 698                 goto err;
 699
 700         desc->validity = usb_alloc_urb(0, GFP_KERNEL);
 701         if (!desc->validity)
 702                 goto err;
 703
 704         desc->response = usb_alloc_urb(0, GFP_KERNEL);
 705         if (!desc->response)
 706                 goto err;
 707
 708         desc->command = usb_alloc_urb(0, GFP_KERNEL);
 709         if (!desc->command)
 710                 goto err;
 711
 712         desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
 713         if (!desc->ubuf)
 714                 goto err;
 715
 716         desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
 717         if (!desc->sbuf)
 718                 goto err;
 719
 720         desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
 721         if (!desc->inbuf)
 722                 goto err;
 723
 724         usb_fill_int_urb(
 725                 desc->validity,
 726                 interface_to_usbdev(intf),
 727                 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
 728                 desc->sbuf,
 729                 desc->wMaxPacketSize,
 730                 wdm_int_callback,
 731                 desc,
 732                 ep->bInterval
 733         );
 734
 735         desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
 736         desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
 737         desc->irq->wValue = 0;
 738         desc->irq->wIndex = desc->inum;
 739         desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
 740
 741         usb_fill_control_urb(
 742                 desc->response,
 743                 interface_to_usbdev(intf),
 744                 /* using common endpoint 0 */
 745                 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
 746                 (unsigned char *)desc->irq,
 747                 desc->inbuf,
 748                 desc->wMaxCommand,
 749                 wdm_in_callback,
 750                 desc
 751         );
 752
 753         spin_lock(&wdm_device_list_lock);
 754         list_add(&desc->device_list, &wdm_device_list);
 755         spin_unlock(&wdm_device_list_lock);
 756
 757         rv = usb_register_dev(intf, &wdm_class);
 758         if (rv < 0)
 759                 goto err;
 760         else
 761                 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
 762 out:
 763         return rv;
 764 err:
 765         cleanup(desc);
 766         return rv;
 767 }
 768
 769 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
 770 {
 771         int rv = -EINVAL;
 772         struct usb_host_interface *iface;
 773         struct usb_endpoint_descriptor *ep;
 774         struct usb_cdc_dmm_desc *dmhd;
 775         u8 *buffer = intf->altsetting->extra;
 776         int buflen = intf->altsetting->extralen;
 777         u16 maxcom = WDM_DEFAULT_BUFSIZE;
 778
 779         if (!buffer)
 780                 goto err;
 781         while (buflen > 2) {
 782                 if (buffer[1] != USB_DT_CS_INTERFACE) {
 783                         dev_err(&intf->dev, "skipping garbage\n");
 784                         goto next_desc;
 785                 }
 786
 787                 switch (buffer[2]) {
 788                 case USB_CDC_HEADER_TYPE:
 789                         break;
 790                 case USB_CDC_DMM_TYPE:
 791                         dmhd = (struct usb_cdc_dmm_desc *)buffer;
 792                         maxcom = le16_to_cpu(dmhd->wMaxCommand);
 793                         dev_dbg(&intf->dev,
 794                                 "Finding maximum buffer length: %d", maxcom);
 795                         break;
 796                 default:
 797                         dev_err(&intf->dev,
 798                                 "Ignoring extra header, type %d, length %d\n",
 799                                 buffer[2], buffer[0]);
 800                         break;
 801                 }
 802 next_desc:
 803                 buflen -= buffer[0];
 804                 buffer += buffer[0];
 805         }
 806
 807         iface = intf->cur_altsetting;
 808         if (iface->desc.bNumEndpoints != 1)
 809                 goto err;
 810         ep = &iface->endpoint[0].desc;
 811
 812         rv = wdm_create(intf, ep, maxcom);
 813
 814 err:
 815         return rv;
 816 }
 817
 818 static void wdm_disconnect(struct usb_interface *intf)
 819 {
 820         struct wdm_device *desc;
 821         unsigned long flags;
 822
 823         usb_deregister_dev(intf, &wdm_class);
 824         desc = wdm_find_device(intf);
 825         mutex_lock(&wdm_mutex);
 826
 827         /* the spinlock makes sure no new urbs are generated in the callbacks */
 828         spin_lock_irqsave(&desc->iuspin, flags);
 829         set_bit(WDM_DISCONNECTING, &desc->flags);
 830         set_bit(WDM_READ, &desc->flags);
 831         /* to terminate pending flushes */
 832         clear_bit(WDM_IN_USE, &desc->flags);
 833         spin_unlock_irqrestore(&desc->iuspin, flags);
 834         wake_up_all(&desc->wait);
 835         mutex_lock(&desc->rlock);
 836         mutex_lock(&desc->wlock);
 837         kill_urbs(desc);
 838         cancel_work_sync(&desc->rxwork);
 839         mutex_unlock(&desc->wlock);
 840         mutex_unlock(&desc->rlock);
 841         if (!desc->count)
 842                 cleanup(desc);
 843         mutex_unlock(&wdm_mutex);
 844 }
 845
 846 #ifdef CONFIG_PM
 847 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
 848 {
 849         struct wdm_device *desc = wdm_find_device(intf);
 850         int rv = 0;
 851
 852         dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
 853
 854         /* if this is an autosuspend the caller does the locking */
 855         if (!PMSG_IS_AUTO(message)) {
 856                 mutex_lock(&desc->rlock);
 857                 mutex_lock(&desc->wlock);
 858         }
 859         spin_lock_irq(&desc->iuspin);
 860
 861         if (PMSG_IS_AUTO(message) &&
 862                         (test_bit(WDM_IN_USE, &desc->flags)
 863                         || test_bit(WDM_RESPONDING, &desc->flags))) {
 864                 spin_unlock_irq(&desc->iuspin);
 865                 rv = -EBUSY;
 866         } else {
 867
 868                 set_bit(WDM_SUSPENDING, &desc->flags);
 869                 spin_unlock_irq(&desc->iuspin);
 870                 /* callback submits work - order is essential */
 871                 kill_urbs(desc);
 872                 cancel_work_sync(&desc->rxwork);
 873         }
 874         if (!PMSG_IS_AUTO(message)) {
 875                 mutex_unlock(&desc->wlock);
 876                 mutex_unlock(&desc->rlock);
 877         }
 878
 879         return rv;
 880 }
 881 #endif
 882
 883 static int recover_from_urb_loss(struct wdm_device *desc)
 884 {
 885         int rv = 0;
 886
 887         if (desc->count) {
 888                 rv = usb_submit_urb(desc->validity, GFP_NOIO);
 889                 if (rv < 0)
 890                         dev_err(&desc->intf->dev,
 891                                 "Error resume submitting int urb - %d\n", rv);
 892         }
 893         return rv;
 894 }
 895
 896 #ifdef CONFIG_PM
 897 static int wdm_resume(struct usb_interface *intf)
 898 {
 899         struct wdm_device *desc = wdm_find_device(intf);
 900         int rv;
 901
 902         dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
 903
 904         clear_bit(WDM_SUSPENDING, &desc->flags);
 905         rv = recover_from_urb_loss(desc);
 906
 907         return rv;
 908 }
 909 #endif
 910
 911 static int wdm_pre_reset(struct usb_interface *intf)
 912 {
 913         struct wdm_device *desc = wdm_find_device(intf);
 914
 915         /*
 916          * we notify everybody using poll of
 917          * an exceptional situation
 918          * must be done before recovery lest a spontaneous
 919          * message from the device is lost
 920          */
 921         spin_lock_irq(&desc->iuspin);
 922         set_bit(WDM_RESETTING, &desc->flags);   /* inform read/write */
 923         set_bit(WDM_READ, &desc->flags);        /* unblock read */
 924         clear_bit(WDM_IN_USE, &desc->flags);    /* unblock write */
 925         desc->rerr = -EINTR;
 926         spin_unlock_irq(&desc->iuspin);
 927         wake_up_all(&desc->wait);
 928         mutex_lock(&desc->rlock);
 929         mutex_lock(&desc->wlock);
 930         kill_urbs(desc);
 931         cancel_work_sync(&desc->rxwork);
 932         return 0;
 933 }
 934
 935 static int wdm_post_reset(struct usb_interface *intf)
 936 {
 937         struct wdm_device *desc = wdm_find_device(intf);
 938         int rv;
 939
 940         clear_bit(WDM_RESETTING, &desc->flags);
 941         rv = recover_from_urb_loss(desc);
 942         mutex_unlock(&desc->wlock);
 943         mutex_unlock(&desc->rlock);
 944         return 0;
 945 }
 946
 947 static struct usb_driver wdm_driver = {
 948         .name =         "cdc_wdm",
 949         .probe =        wdm_probe,
 950         .disconnect =   wdm_disconnect,
 951 #ifdef CONFIG_PM
 952         .suspend =      wdm_suspend,
 953         .resume =       wdm_resume,
 954         .reset_resume = wdm_resume,
 955 #endif
 956         .pre_reset =    wdm_pre_reset,
 957         .post_reset =   wdm_post_reset,
 958         .id_table =     wdm_ids,
 959         .supports_autosuspend = 1,
 960 };
 961
 962 module_usb_driver(wdm_driver);
 963
 964 MODULE_AUTHOR(DRIVER_AUTHOR);
 965 MODULE_DESCRIPTION(DRIVER_DESC);
 966 MODULE_LICENSE("GPL");