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