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