Pileus Git - ~andy/linux/blob - 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 #include <linux/usb/cdc-wdm.h>
  27
  28 /*
  29  * Version Information
  30  */
  31 #define DRIVER_VERSION "v0.03"
  32 #define DRIVER_AUTHOR "Oliver Neukum"
  33 #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management"
  34
  35 #define HUAWEI_VENDOR_ID        0x12D1
  36
  37 static const struct usb_device_id wdm_ids[] = {
  38         {
  39                 .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS |
  40                                  USB_DEVICE_ID_MATCH_INT_SUBCLASS,
  41                 .bInterfaceClass = USB_CLASS_COMM,
  42                 .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM
  43         },
  44         {
  45                 /*
  46                  * Huawei E392, E398 and possibly other Qualcomm based modems
  47                  * embed the Qualcomm QMI protocol inside CDC on CDC ECM like
  48                  * control interfaces.  Userspace access to this is required
  49                  * to configure the accompanying data interface
  50                  */
  51                 .match_flags        = USB_DEVICE_ID_MATCH_VENDOR |
  52                                         USB_DEVICE_ID_MATCH_INT_INFO,
  53                 .idVendor           = HUAWEI_VENDOR_ID,
  54                 .bInterfaceClass    = USB_CLASS_VENDOR_SPEC,
  55                 .bInterfaceSubClass = 1,
  56                 .bInterfaceProtocol = 9, /* NOTE: CDC ECM control interface! */
  57         },
  58         { }
  59 };
  60
  61 MODULE_DEVICE_TABLE (usb, wdm_ids);
  62
  63 #define WDM_MINOR_BASE  176
  64
  65
  66 #define WDM_IN_USE              1
  67 #define WDM_DISCONNECTING       2
  68 #define WDM_RESULT              3
  69 #define WDM_READ                4
  70 #define WDM_INT_STALL           5
  71 #define WDM_POLL_RUNNING        6
  72 #define WDM_RESPONDING          7
  73 #define WDM_SUSPENDING          8
  74 #define WDM_RESETTING           9
  75
  76 #define WDM_MAX                 16
  77
  78 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
  79 #define WDM_DEFAULT_BUFSIZE     256
  80
  81 static DEFINE_MUTEX(wdm_mutex);
  82 static DEFINE_SPINLOCK(wdm_device_list_lock);
  83 static LIST_HEAD(wdm_device_list);
  84
  85 /* --- method tables --- */
  86
  87 struct wdm_device {
  88         u8                      *inbuf; /* buffer for response */
  89         u8                      *outbuf; /* buffer for command */
  90         u8                      *sbuf; /* buffer for status */
  91         u8                      *ubuf; /* buffer for copy to user space */
  92
  93         struct urb              *command;
  94         struct urb              *response;
  95         struct urb              *validity;
  96         struct usb_interface    *intf;
  97         struct usb_ctrlrequest  *orq;
  98         struct usb_ctrlrequest  *irq;
  99         spinlock_t              iuspin;
 100
 101         unsigned long           flags;
 102         u16                     bufsize;
 103         u16                     wMaxCommand;
 104         u16                     wMaxPacketSize;
 105         __le16                  inum;
 106         int                     reslength;
 107         int                     length;
 108         int                     read;
 109         int                     count;
 110         dma_addr_t              shandle;
 111         dma_addr_t              ihandle;
 112         struct mutex            wlock;
 113         struct mutex            rlock;
 114         wait_queue_head_t       wait;
 115         struct work_struct      rxwork;
 116         int                     werr;
 117         int                     rerr;
 118
 119         struct list_head        device_list;
 120         int                     (*manage_power)(struct usb_interface *, int);
 121 };
 122
 123 static struct usb_driver wdm_driver;
 124
 125 /* return intfdata if we own the interface, else look up intf in the list */
 126 static struct wdm_device *wdm_find_device(struct usb_interface *intf)
 127 {
 128         struct wdm_device *desc = NULL;
 129
 130         spin_lock(&wdm_device_list_lock);
 131         list_for_each_entry(desc, &wdm_device_list, device_list)
 132                 if (desc->intf == intf)
 133                         break;
 134         spin_unlock(&wdm_device_list_lock);
 135
 136         return desc;
 137 }
 138
 139 static struct wdm_device *wdm_find_device_by_minor(int minor)
 140 {
 141         struct wdm_device *desc = NULL;
 142
 143         spin_lock(&wdm_device_list_lock);
 144         list_for_each_entry(desc, &wdm_device_list, device_list)
 145                 if (desc->intf->minor == minor)
 146                         break;
 147         spin_unlock(&wdm_device_list_lock);
 148
 149         return desc;
 150 }
 151
 152 /* --- callbacks --- */
 153 static void wdm_out_callback(struct urb *urb)
 154 {
 155         struct wdm_device *desc;
 156         desc = urb->context;
 157         spin_lock(&desc->iuspin);
 158         desc->werr = urb->status;
 159         spin_unlock(&desc->iuspin);
 160         clear_bit(WDM_IN_USE, &desc->flags);
 161         kfree(desc->outbuf);
 162         wake_up(&desc->wait);
 163 }
 164
 165 static void wdm_in_callback(struct urb *urb)
 166 {
 167         struct wdm_device *desc = urb->context;
 168         int status = urb->status;
 169
 170         spin_lock(&desc->iuspin);
 171         clear_bit(WDM_RESPONDING, &desc->flags);
 172
 173         if (status) {
 174                 switch (status) {
 175                 case -ENOENT:
 176                         dev_dbg(&desc->intf->dev,
 177                                 "nonzero urb status received: -ENOENT");
 178                         goto skip_error;
 179                 case -ECONNRESET:
 180                         dev_dbg(&desc->intf->dev,
 181                                 "nonzero urb status received: -ECONNRESET");
 182                         goto skip_error;
 183                 case -ESHUTDOWN:
 184                         dev_dbg(&desc->intf->dev,
 185                                 "nonzero urb status received: -ESHUTDOWN");
 186                         goto skip_error;
 187                 case -EPIPE:
 188                         dev_err(&desc->intf->dev,
 189                                 "nonzero urb status received: -EPIPE\n");
 190                         break;
 191                 default:
 192                         dev_err(&desc->intf->dev,
 193                                 "Unexpected error %d\n", status);
 194                         break;
 195                 }
 196         }
 197
 198         desc->rerr = status;
 199         desc->reslength = urb->actual_length;
 200         memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
 201         desc->length += desc->reslength;
 202 skip_error:
 203         wake_up(&desc->wait);
 204
 205         set_bit(WDM_READ, &desc->flags);
 206         spin_unlock(&desc->iuspin);
 207 }
 208
 209 static void wdm_int_callback(struct urb *urb)
 210 {
 211         int rv = 0;
 212         int status = urb->status;
 213         struct wdm_device *desc;
 214         struct usb_cdc_notification *dr;
 215
 216         desc = urb->context;
 217         dr = (struct usb_cdc_notification *)desc->sbuf;
 218
 219         if (status) {
 220                 switch (status) {
 221                 case -ESHUTDOWN:
 222                 case -ENOENT:
 223                 case -ECONNRESET:
 224                         return; /* unplug */
 225                 case -EPIPE:
 226                         set_bit(WDM_INT_STALL, &desc->flags);
 227                         dev_err(&desc->intf->dev, "Stall on int endpoint\n");
 228                         goto sw; /* halt is cleared in work */
 229                 default:
 230                         dev_err(&desc->intf->dev,
 231                                 "nonzero urb status received: %d\n", status);
 232                         break;
 233                 }
 234         }
 235
 236         if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
 237                 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
 238                         urb->actual_length);
 239                 goto exit;
 240         }
 241
 242         switch (dr->bNotificationType) {
 243         case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
 244                 dev_dbg(&desc->intf->dev,
 245                         "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
 246                         dr->wIndex, dr->wLength);
 247                 break;
 248
 249         case USB_CDC_NOTIFY_NETWORK_CONNECTION:
 250
 251                 dev_dbg(&desc->intf->dev,
 252                         "NOTIFY_NETWORK_CONNECTION %s network",
 253                         dr->wValue ? "connected to" : "disconnected from");
 254                 goto exit;
 255         default:
 256                 clear_bit(WDM_POLL_RUNNING, &desc->flags);
 257                 dev_err(&desc->intf->dev,
 258                         "unknown notification %d received: index %d len %d\n",
 259                         dr->bNotificationType, dr->wIndex, dr->wLength);
 260                 goto exit;
 261         }
 262
 263         spin_lock(&desc->iuspin);
 264         clear_bit(WDM_READ, &desc->flags);
 265         set_bit(WDM_RESPONDING, &desc->flags);
 266         if (!test_bit(WDM_DISCONNECTING, &desc->flags)
 267                 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
 268                 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
 269                 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
 270                         __func__, rv);
 271         }
 272         spin_unlock(&desc->iuspin);
 273         if (rv < 0) {
 274                 clear_bit(WDM_RESPONDING, &desc->flags);
 275                 if (rv == -EPERM)
 276                         return;
 277                 if (rv == -ENOMEM) {
 278 sw:
 279                         rv = schedule_work(&desc->rxwork);
 280                         if (rv)
 281                                 dev_err(&desc->intf->dev,
 282                                         "Cannot schedule work\n");
 283                 }
 284         }
 285 exit:
 286         rv = usb_submit_urb(urb, GFP_ATOMIC);
 287         if (rv)
 288                 dev_err(&desc->intf->dev,
 289                         "%s - usb_submit_urb failed with result %d\n",
 290                         __func__, rv);
 291
 292 }
 293
 294 static void kill_urbs(struct wdm_device *desc)
 295 {
 296         /* the order here is essential */
 297         usb_kill_urb(desc->command);
 298         usb_kill_urb(desc->validity);
 299         usb_kill_urb(desc->response);
 300 }
 301
 302 static void free_urbs(struct wdm_device *desc)
 303 {
 304         usb_free_urb(desc->validity);
 305         usb_free_urb(desc->response);
 306         usb_free_urb(desc->command);
 307 }
 308
 309 static void cleanup(struct wdm_device *desc)
 310 {
 311         spin_lock(&wdm_device_list_lock);
 312         list_del(&desc->device_list);
 313         spin_unlock(&wdm_device_list_lock);
 314         kfree(desc->sbuf);
 315         kfree(desc->inbuf);
 316         kfree(desc->orq);
 317         kfree(desc->irq);
 318         kfree(desc->ubuf);
 319         free_urbs(desc);
 320         kfree(desc);
 321 }
 322
 323 static ssize_t wdm_write
 324 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 325 {
 326         u8 *buf;
 327         int rv = -EMSGSIZE, r, we;
 328         struct wdm_device *desc = file->private_data;
 329         struct usb_ctrlrequest *req;
 330
 331         if (count > desc->wMaxCommand)
 332                 count = desc->wMaxCommand;
 333
 334         spin_lock_irq(&desc->iuspin);
 335         we = desc->werr;
 336         desc->werr = 0;
 337         spin_unlock_irq(&desc->iuspin);
 338         if (we < 0)
 339                 return -EIO;
 340
 341         desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
 342         if (!buf) {
 343                 rv = -ENOMEM;
 344                 goto outnl;
 345         }
 346
 347         r = copy_from_user(buf, buffer, count);
 348         if (r > 0) {
 349                 kfree(buf);
 350                 rv = -EFAULT;
 351                 goto outnl;
 352         }
 353
 354         /* concurrent writes and disconnect */
 355         r = mutex_lock_interruptible(&desc->wlock);
 356         rv = -ERESTARTSYS;
 357         if (r) {
 358                 kfree(buf);
 359                 goto outnl;
 360         }
 361
 362         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 363                 kfree(buf);
 364                 rv = -ENODEV;
 365                 goto outnp;
 366         }
 367
 368         r = usb_autopm_get_interface(desc->intf);
 369         if (r < 0) {
 370                 kfree(buf);
 371                 goto outnp;
 372         }
 373
 374         if (!(file->f_flags & O_NONBLOCK))
 375                 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
 376                                                                 &desc->flags));
 377         else
 378                 if (test_bit(WDM_IN_USE, &desc->flags))
 379                         r = -EAGAIN;
 380
 381         if (test_bit(WDM_RESETTING, &desc->flags))
 382                 r = -EIO;
 383
 384         if (r < 0) {
 385                 kfree(buf);
 386                 goto out;
 387         }
 388
 389         req = desc->orq;
 390         usb_fill_control_urb(
 391                 desc->command,
 392                 interface_to_usbdev(desc->intf),
 393                 /* using common endpoint 0 */
 394                 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
 395                 (unsigned char *)req,
 396                 buf,
 397                 count,
 398                 wdm_out_callback,
 399                 desc
 400         );
 401
 402         req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
 403                              USB_RECIP_INTERFACE);
 404         req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
 405         req->wValue = 0;
 406         req->wIndex = desc->inum;
 407         req->wLength = cpu_to_le16(count);
 408         set_bit(WDM_IN_USE, &desc->flags);
 409
 410         rv = usb_submit_urb(desc->command, GFP_KERNEL);
 411         if (rv < 0) {
 412                 kfree(buf);
 413                 clear_bit(WDM_IN_USE, &desc->flags);
 414                 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
 415         } else {
 416                 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
 417                         req->wIndex);
 418         }
 419 out:
 420         usb_autopm_put_interface(desc->intf);
 421 outnp:
 422         mutex_unlock(&desc->wlock);
 423 outnl:
 424         return rv < 0 ? rv : count;
 425 }
 426
 427 static ssize_t wdm_read
 428 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 429 {
 430         int rv, cntr;
 431         int i = 0;
 432         struct wdm_device *desc = file->private_data;
 433
 434
 435         rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
 436         if (rv < 0)
 437                 return -ERESTARTSYS;
 438
 439         cntr = ACCESS_ONCE(desc->length);
 440         if (cntr == 0) {
 441                 desc->read = 0;
 442 retry:
 443                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 444                         rv = -ENODEV;
 445                         goto err;
 446                 }
 447                 i++;
 448                 if (file->f_flags & O_NONBLOCK) {
 449                         if (!test_bit(WDM_READ, &desc->flags)) {
 450                                 rv = cntr ? cntr : -EAGAIN;
 451                                 goto err;
 452                         }
 453                         rv = 0;
 454                 } else {
 455                         rv = wait_event_interruptible(desc->wait,
 456                                 test_bit(WDM_READ, &desc->flags));
 457                 }
 458
 459                 /* may have happened while we slept */
 460                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 461                         rv = -ENODEV;
 462                         goto err;
 463                 }
 464                 if (test_bit(WDM_RESETTING, &desc->flags)) {
 465                         rv = -EIO;
 466                         goto err;
 467                 }
 468                 usb_mark_last_busy(interface_to_usbdev(desc->intf));
 469                 if (rv < 0) {
 470                         rv = -ERESTARTSYS;
 471                         goto err;
 472                 }
 473
 474                 spin_lock_irq(&desc->iuspin);
 475
 476                 if (desc->rerr) { /* read completed, error happened */
 477                         desc->rerr = 0;
 478                         spin_unlock_irq(&desc->iuspin);
 479                         rv = -EIO;
 480                         goto err;
 481                 }
 482                 /*
 483                  * recheck whether we've lost the race
 484                  * against the completion handler
 485                  */
 486                 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
 487                         spin_unlock_irq(&desc->iuspin);
 488                         goto retry;
 489                 }
 490                 if (!desc->reslength) { /* zero length read */
 491                         spin_unlock_irq(&desc->iuspin);
 492                         goto retry;
 493                 }
 494                 cntr = desc->length;
 495                 spin_unlock_irq(&desc->iuspin);
 496         }
 497
 498         if (cntr > count)
 499                 cntr = count;
 500         rv = copy_to_user(buffer, desc->ubuf, cntr);
 501         if (rv > 0) {
 502                 rv = -EFAULT;
 503                 goto err;
 504         }
 505
 506         spin_lock_irq(&desc->iuspin);
 507
 508         for (i = 0; i < desc->length - cntr; i++)
 509                 desc->ubuf[i] = desc->ubuf[i + cntr];
 510
 511         desc->length -= cntr;
 512         /* in case we had outstanding data */
 513         if (!desc->length)
 514                 clear_bit(WDM_READ, &desc->flags);
 515
 516         spin_unlock_irq(&desc->iuspin);
 517
 518         rv = cntr;
 519
 520 err:
 521         mutex_unlock(&desc->rlock);
 522         return rv;
 523 }
 524
 525 static int wdm_flush(struct file *file, fl_owner_t id)
 526 {
 527         struct wdm_device *desc = file->private_data;
 528
 529         wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
 530         if (desc->werr < 0)
 531                 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
 532                         desc->werr);
 533
 534         return desc->werr;
 535 }
 536
 537 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
 538 {
 539         struct wdm_device *desc = file->private_data;
 540         unsigned long flags;
 541         unsigned int mask = 0;
 542
 543         spin_lock_irqsave(&desc->iuspin, flags);
 544         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 545                 mask = POLLERR;
 546                 spin_unlock_irqrestore(&desc->iuspin, flags);
 547                 goto desc_out;
 548         }
 549         if (test_bit(WDM_READ, &desc->flags))
 550                 mask = POLLIN | POLLRDNORM;
 551         if (desc->rerr || desc->werr)
 552                 mask |= POLLERR;
 553         if (!test_bit(WDM_IN_USE, &desc->flags))
 554                 mask |= POLLOUT | POLLWRNORM;
 555         spin_unlock_irqrestore(&desc->iuspin, flags);
 556
 557         poll_wait(file, &desc->wait, wait);
 558
 559 desc_out:
 560         return mask;
 561 }
 562
 563 static int wdm_open(struct inode *inode, struct file *file)
 564 {
 565         int minor = iminor(inode);
 566         int rv = -ENODEV;
 567         struct usb_interface *intf;
 568         struct wdm_device *desc;
 569
 570         mutex_lock(&wdm_mutex);
 571         desc = wdm_find_device_by_minor(minor);
 572         if (!desc)
 573                 goto out;
 574
 575         intf = desc->intf;
 576         if (test_bit(WDM_DISCONNECTING, &desc->flags))
 577                 goto out;
 578         file->private_data = desc;
 579
 580         rv = usb_autopm_get_interface(desc->intf);
 581         if (rv < 0) {
 582                 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
 583                 goto out;
 584         }
 585
 586         /* using write lock to protect desc->count */
 587         mutex_lock(&desc->wlock);
 588         if (!desc->count++) {
 589                 desc->werr = 0;
 590                 desc->rerr = 0;
 591                 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
 592                 if (rv < 0) {
 593                         desc->count--;
 594                         dev_err(&desc->intf->dev,
 595                                 "Error submitting int urb - %d\n", rv);
 596                 }
 597         } else {
 598                 rv = 0;
 599         }
 600         mutex_unlock(&desc->wlock);
 601         if (desc->count == 1)
 602                 desc->manage_power(intf, 1);
 603         usb_autopm_put_interface(desc->intf);
 604 out:
 605         mutex_unlock(&wdm_mutex);
 606         return rv;
 607 }
 608
 609 static int wdm_release(struct inode *inode, struct file *file)
 610 {
 611         struct wdm_device *desc = file->private_data;
 612
 613         mutex_lock(&wdm_mutex);
 614
 615         /* using write lock to protect desc->count */
 616         mutex_lock(&desc->wlock);
 617         desc->count--;
 618         mutex_unlock(&desc->wlock);
 619
 620         if (!desc->count) {
 621                 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
 622                 kill_urbs(desc);
 623                 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 624                         desc->manage_power(desc->intf, 0);
 625         }
 626         mutex_unlock(&wdm_mutex);
 627         return 0;
 628 }
 629
 630 static const struct file_operations wdm_fops = {
 631         .owner =        THIS_MODULE,
 632         .read =         wdm_read,
 633         .write =        wdm_write,
 634         .open =         wdm_open,
 635         .flush =        wdm_flush,
 636         .release =      wdm_release,
 637         .poll =         wdm_poll,
 638         .llseek =       noop_llseek,
 639 };
 640
 641 static struct usb_class_driver wdm_class = {
 642         .name =         "cdc-wdm%d",
 643         .fops =         &wdm_fops,
 644         .minor_base =   WDM_MINOR_BASE,
 645 };
 646
 647 /* --- error handling --- */
 648 static void wdm_rxwork(struct work_struct *work)
 649 {
 650         struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
 651         unsigned long flags;
 652         int rv;
 653
 654         spin_lock_irqsave(&desc->iuspin, flags);
 655         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 656                 spin_unlock_irqrestore(&desc->iuspin, flags);
 657         } else {
 658                 spin_unlock_irqrestore(&desc->iuspin, flags);
 659                 rv = usb_submit_urb(desc->response, GFP_KERNEL);
 660                 if (rv < 0 && rv != -EPERM) {
 661                         spin_lock_irqsave(&desc->iuspin, flags);
 662                         if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 663                                 schedule_work(&desc->rxwork);
 664                         spin_unlock_irqrestore(&desc->iuspin, flags);
 665                 }
 666         }
 667 }
 668
 669 /* --- hotplug --- */
 670
 671 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep,
 672                 u16 bufsize, int (*manage_power)(struct usb_interface *, int))
 673 {
 674         int rv = -ENOMEM;
 675         struct wdm_device *desc;
 676
 677         desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
 678         if (!desc)
 679                 goto out;
 680         INIT_LIST_HEAD(&desc->device_list);
 681         mutex_init(&desc->rlock);
 682         mutex_init(&desc->wlock);
 683         spin_lock_init(&desc->iuspin);
 684         init_waitqueue_head(&desc->wait);
 685         desc->wMaxCommand = bufsize;
 686         /* this will be expanded and needed in hardware endianness */
 687         desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
 688         desc->intf = intf;
 689         INIT_WORK(&desc->rxwork, wdm_rxwork);
 690
 691         rv = -EINVAL;
 692         if (!usb_endpoint_is_int_in(ep))
 693                 goto err;
 694
 695         desc->wMaxPacketSize = usb_endpoint_maxp(ep);
 696
 697         desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 698         if (!desc->orq)
 699                 goto err;
 700         desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 701         if (!desc->irq)
 702                 goto err;
 703
 704         desc->validity = usb_alloc_urb(0, GFP_KERNEL);
 705         if (!desc->validity)
 706                 goto err;
 707
 708         desc->response = usb_alloc_urb(0, GFP_KERNEL);
 709         if (!desc->response)
 710                 goto err;
 711
 712         desc->command = usb_alloc_urb(0, GFP_KERNEL);
 713         if (!desc->command)
 714                 goto err;
 715
 716         desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
 717         if (!desc->ubuf)
 718                 goto err;
 719
 720         desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
 721         if (!desc->sbuf)
 722                 goto err;
 723
 724         desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
 725         if (!desc->inbuf)
 726                 goto err;
 727
 728         usb_fill_int_urb(
 729                 desc->validity,
 730                 interface_to_usbdev(intf),
 731                 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
 732                 desc->sbuf,
 733                 desc->wMaxPacketSize,
 734                 wdm_int_callback,
 735                 desc,
 736                 ep->bInterval
 737         );
 738
 739         desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
 740         desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
 741         desc->irq->wValue = 0;
 742         desc->irq->wIndex = desc->inum;
 743         desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
 744
 745         usb_fill_control_urb(
 746                 desc->response,
 747                 interface_to_usbdev(intf),
 748                 /* using common endpoint 0 */
 749                 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
 750                 (unsigned char *)desc->irq,
 751                 desc->inbuf,
 752                 desc->wMaxCommand,
 753                 wdm_in_callback,
 754                 desc
 755         );
 756
 757         desc->manage_power = manage_power;
 758
 759         spin_lock(&wdm_device_list_lock);
 760         list_add(&desc->device_list, &wdm_device_list);
 761         spin_unlock(&wdm_device_list_lock);
 762
 763         rv = usb_register_dev(intf, &wdm_class);
 764         if (rv < 0)
 765                 goto err;
 766         else
 767                 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
 768 out:
 769         return rv;
 770 err:
 771         cleanup(desc);
 772         return rv;
 773 }
 774
 775 static int wdm_manage_power(struct usb_interface *intf, int on)
 776 {
 777         /* need autopm_get/put here to ensure the usbcore sees the new value */
 778         int rv = usb_autopm_get_interface(intf);
 779         if (rv < 0)
 780                 goto err;
 781
 782         intf->needs_remote_wakeup = on;
 783         usb_autopm_put_interface(intf);
 784 err:
 785         return rv;
 786 }
 787
 788 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
 789 {
 790         int rv = -EINVAL;
 791         struct usb_host_interface *iface;
 792         struct usb_endpoint_descriptor *ep;
 793         struct usb_cdc_dmm_desc *dmhd;
 794         u8 *buffer = intf->altsetting->extra;
 795         int buflen = intf->altsetting->extralen;
 796         u16 maxcom = WDM_DEFAULT_BUFSIZE;
 797
 798         if (!buffer)
 799                 goto err;
 800         while (buflen > 2) {
 801                 if (buffer[1] != USB_DT_CS_INTERFACE) {
 802                         dev_err(&intf->dev, "skipping garbage\n");
 803                         goto next_desc;
 804                 }
 805
 806                 switch (buffer[2]) {
 807                 case USB_CDC_HEADER_TYPE:
 808                         break;
 809                 case USB_CDC_DMM_TYPE:
 810                         dmhd = (struct usb_cdc_dmm_desc *)buffer;
 811                         maxcom = le16_to_cpu(dmhd->wMaxCommand);
 812                         dev_dbg(&intf->dev,
 813                                 "Finding maximum buffer length: %d", maxcom);
 814                         break;
 815                 default:
 816                         dev_err(&intf->dev,
 817                                 "Ignoring extra header, type %d, length %d\n",
 818                                 buffer[2], buffer[0]);
 819                         break;
 820                 }
 821 next_desc:
 822                 buflen -= buffer[0];
 823                 buffer += buffer[0];
 824         }
 825
 826         iface = intf->cur_altsetting;
 827         if (iface->desc.bNumEndpoints != 1)
 828                 goto err;
 829         ep = &iface->endpoint[0].desc;
 830
 831         rv = wdm_create(intf, ep, maxcom, &wdm_manage_power);
 832
 833 err:
 834         return rv;
 835 }
 836
 837 /**
 838  * usb_cdc_wdm_register - register a WDM subdriver
 839  * @intf: usb interface the subdriver will associate with
 840  * @ep: interrupt endpoint to monitor for notifications
 841  * @bufsize: maximum message size to support for read/write
 842  *
 843  * Create WDM usb class character device and associate it with intf
 844  * without binding, allowing another driver to manage the interface.
 845  *
 846  * The subdriver will manage the given interrupt endpoint exclusively
 847  * and will issue control requests referring to the given intf. It
 848  * will otherwise avoid interferring, and in particular not do
 849  * usb_set_intfdata/usb_get_intfdata on intf.
 850  *
 851  * The return value is a pointer to the subdriver's struct usb_driver.
 852  * The registering driver is responsible for calling this subdriver's
 853  * disconnect, suspend, resume, pre_reset and post_reset methods from
 854  * its own.
 855  */
 856 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf,
 857                                         struct usb_endpoint_descriptor *ep,
 858                                         int bufsize,
 859                                         int (*manage_power)(struct usb_interface *, int))
 860 {
 861         int rv = -EINVAL;
 862
 863         rv = wdm_create(intf, ep, bufsize, manage_power);
 864         if (rv < 0)
 865                 goto err;
 866
 867         return &wdm_driver;
 868 err:
 869         return ERR_PTR(rv);
 870 }
 871 EXPORT_SYMBOL(usb_cdc_wdm_register);
 872
 873 static void wdm_disconnect(struct usb_interface *intf)
 874 {
 875         struct wdm_device *desc;
 876         unsigned long flags;
 877
 878         usb_deregister_dev(intf, &wdm_class);
 879         desc = wdm_find_device(intf);
 880         mutex_lock(&wdm_mutex);
 881
 882         /* the spinlock makes sure no new urbs are generated in the callbacks */
 883         spin_lock_irqsave(&desc->iuspin, flags);
 884         set_bit(WDM_DISCONNECTING, &desc->flags);
 885         set_bit(WDM_READ, &desc->flags);
 886         /* to terminate pending flushes */
 887         clear_bit(WDM_IN_USE, &desc->flags);
 888         spin_unlock_irqrestore(&desc->iuspin, flags);
 889         wake_up_all(&desc->wait);
 890         mutex_lock(&desc->rlock);
 891         mutex_lock(&desc->wlock);
 892         kill_urbs(desc);
 893         cancel_work_sync(&desc->rxwork);
 894         mutex_unlock(&desc->wlock);
 895         mutex_unlock(&desc->rlock);
 896         if (!desc->count)
 897                 cleanup(desc);
 898         mutex_unlock(&wdm_mutex);
 899 }
 900
 901 #ifdef CONFIG_PM
 902 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
 903 {
 904         struct wdm_device *desc = wdm_find_device(intf);
 905         int rv = 0;
 906
 907         dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
 908
 909         /* if this is an autosuspend the caller does the locking */
 910         if (!PMSG_IS_AUTO(message)) {
 911                 mutex_lock(&desc->rlock);
 912                 mutex_lock(&desc->wlock);
 913         }
 914         spin_lock_irq(&desc->iuspin);
 915
 916         if (PMSG_IS_AUTO(message) &&
 917                         (test_bit(WDM_IN_USE, &desc->flags)
 918                         || test_bit(WDM_RESPONDING, &desc->flags))) {
 919                 spin_unlock_irq(&desc->iuspin);
 920                 rv = -EBUSY;
 921         } else {
 922
 923                 set_bit(WDM_SUSPENDING, &desc->flags);
 924                 spin_unlock_irq(&desc->iuspin);
 925                 /* callback submits work - order is essential */
 926                 kill_urbs(desc);
 927                 cancel_work_sync(&desc->rxwork);
 928         }
 929         if (!PMSG_IS_AUTO(message)) {
 930                 mutex_unlock(&desc->wlock);
 931                 mutex_unlock(&desc->rlock);
 932         }
 933
 934         return rv;
 935 }
 936 #endif
 937
 938 static int recover_from_urb_loss(struct wdm_device *desc)
 939 {
 940         int rv = 0;
 941
 942         if (desc->count) {
 943                 rv = usb_submit_urb(desc->validity, GFP_NOIO);
 944                 if (rv < 0)
 945                         dev_err(&desc->intf->dev,
 946                                 "Error resume submitting int urb - %d\n", rv);
 947         }
 948         return rv;
 949 }
 950
 951 #ifdef CONFIG_PM
 952 static int wdm_resume(struct usb_interface *intf)
 953 {
 954         struct wdm_device *desc = wdm_find_device(intf);
 955         int rv;
 956
 957         dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
 958
 959         clear_bit(WDM_SUSPENDING, &desc->flags);
 960         rv = recover_from_urb_loss(desc);
 961
 962         return rv;
 963 }
 964 #endif
 965
 966 static int wdm_pre_reset(struct usb_interface *intf)
 967 {
 968         struct wdm_device *desc = wdm_find_device(intf);
 969
 970         /*
 971          * we notify everybody using poll of
 972          * an exceptional situation
 973          * must be done before recovery lest a spontaneous
 974          * message from the device is lost
 975          */
 976         spin_lock_irq(&desc->iuspin);
 977         set_bit(WDM_RESETTING, &desc->flags);   /* inform read/write */
 978         set_bit(WDM_READ, &desc->flags);        /* unblock read */
 979         clear_bit(WDM_IN_USE, &desc->flags);    /* unblock write */
 980         desc->rerr = -EINTR;
 981         spin_unlock_irq(&desc->iuspin);
 982         wake_up_all(&desc->wait);
 983         mutex_lock(&desc->rlock);
 984         mutex_lock(&desc->wlock);
 985         kill_urbs(desc);
 986         cancel_work_sync(&desc->rxwork);
 987         return 0;
 988 }
 989
 990 static int wdm_post_reset(struct usb_interface *intf)
 991 {
 992         struct wdm_device *desc = wdm_find_device(intf);
 993         int rv;
 994
 995         clear_bit(WDM_RESETTING, &desc->flags);
 996         rv = recover_from_urb_loss(desc);
 997         mutex_unlock(&desc->wlock);
 998         mutex_unlock(&desc->rlock);
 999         return 0;
1000 }
1001
1002 static struct usb_driver wdm_driver = {
1003         .name =         "cdc_wdm",
1004         .probe =        wdm_probe,
1005         .disconnect =   wdm_disconnect,
1006 #ifdef CONFIG_PM
1007         .suspend =      wdm_suspend,
1008         .resume =       wdm_resume,
1009         .reset_resume = wdm_resume,
1010 #endif
1011         .pre_reset =    wdm_pre_reset,
1012         .post_reset =   wdm_post_reset,
1013         .id_table =     wdm_ids,
1014         .supports_autosuspend = 1,
1015 };
1016
1017 module_usb_driver(wdm_driver);
1018
1019 MODULE_AUTHOR(DRIVER_AUTHOR);
1020 MODULE_DESCRIPTION(DRIVER_DESC);
1021 MODULE_LICENSE("GPL");