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         kfree(desc->outbuf);
 161         desc->outbuf = NULL;
 162         clear_bit(WDM_IN_USE, &desc->flags);
 163         wake_up(&desc->wait);
 164 }
 165
 166 static void wdm_in_callback(struct urb *urb)
 167 {
 168         struct wdm_device *desc = urb->context;
 169         int status = urb->status;
 170
 171         spin_lock(&desc->iuspin);
 172         clear_bit(WDM_RESPONDING, &desc->flags);
 173
 174         if (status) {
 175                 switch (status) {
 176                 case -ENOENT:
 177                         dev_dbg(&desc->intf->dev,
 178                                 "nonzero urb status received: -ENOENT");
 179                         goto skip_error;
 180                 case -ECONNRESET:
 181                         dev_dbg(&desc->intf->dev,
 182                                 "nonzero urb status received: -ECONNRESET");
 183                         goto skip_error;
 184                 case -ESHUTDOWN:
 185                         dev_dbg(&desc->intf->dev,
 186                                 "nonzero urb status received: -ESHUTDOWN");
 187                         goto skip_error;
 188                 case -EPIPE:
 189                         dev_err(&desc->intf->dev,
 190                                 "nonzero urb status received: -EPIPE\n");
 191                         break;
 192                 default:
 193                         dev_err(&desc->intf->dev,
 194                                 "Unexpected error %d\n", status);
 195                         break;
 196                 }
 197         }
 198
 199         desc->rerr = status;
 200         desc->reslength = urb->actual_length;
 201         memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
 202         desc->length += desc->reslength;
 203 skip_error:
 204         wake_up(&desc->wait);
 205
 206         set_bit(WDM_READ, &desc->flags);
 207         spin_unlock(&desc->iuspin);
 208 }
 209
 210 static void wdm_int_callback(struct urb *urb)
 211 {
 212         int rv = 0;
 213         int status = urb->status;
 214         struct wdm_device *desc;
 215         struct usb_cdc_notification *dr;
 216
 217         desc = urb->context;
 218         dr = (struct usb_cdc_notification *)desc->sbuf;
 219
 220         if (status) {
 221                 switch (status) {
 222                 case -ESHUTDOWN:
 223                 case -ENOENT:
 224                 case -ECONNRESET:
 225                         return; /* unplug */
 226                 case -EPIPE:
 227                         set_bit(WDM_INT_STALL, &desc->flags);
 228                         dev_err(&desc->intf->dev, "Stall on int endpoint\n");
 229                         goto sw; /* halt is cleared in work */
 230                 default:
 231                         dev_err(&desc->intf->dev,
 232                                 "nonzero urb status received: %d\n", status);
 233                         break;
 234                 }
 235         }
 236
 237         if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
 238                 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
 239                         urb->actual_length);
 240                 goto exit;
 241         }
 242
 243         switch (dr->bNotificationType) {
 244         case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
 245                 dev_dbg(&desc->intf->dev,
 246                         "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
 247                         dr->wIndex, dr->wLength);
 248                 break;
 249
 250         case USB_CDC_NOTIFY_NETWORK_CONNECTION:
 251
 252                 dev_dbg(&desc->intf->dev,
 253                         "NOTIFY_NETWORK_CONNECTION %s network",
 254                         dr->wValue ? "connected to" : "disconnected from");
 255                 goto exit;
 256         default:
 257                 clear_bit(WDM_POLL_RUNNING, &desc->flags);
 258                 dev_err(&desc->intf->dev,
 259                         "unknown notification %d received: index %d len %d\n",
 260                         dr->bNotificationType, dr->wIndex, dr->wLength);
 261                 goto exit;
 262         }
 263
 264         spin_lock(&desc->iuspin);
 265         clear_bit(WDM_READ, &desc->flags);
 266         set_bit(WDM_RESPONDING, &desc->flags);
 267         if (!test_bit(WDM_DISCONNECTING, &desc->flags)
 268                 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
 269                 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
 270                 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
 271                         __func__, rv);
 272         }
 273         spin_unlock(&desc->iuspin);
 274         if (rv < 0) {
 275                 clear_bit(WDM_RESPONDING, &desc->flags);
 276                 if (rv == -EPERM)
 277                         return;
 278                 if (rv == -ENOMEM) {
 279 sw:
 280                         rv = schedule_work(&desc->rxwork);
 281                         if (rv)
 282                                 dev_err(&desc->intf->dev,
 283                                         "Cannot schedule work\n");
 284                 }
 285         }
 286 exit:
 287         rv = usb_submit_urb(urb, GFP_ATOMIC);
 288         if (rv)
 289                 dev_err(&desc->intf->dev,
 290                         "%s - usb_submit_urb failed with result %d\n",
 291                         __func__, rv);
 292
 293 }
 294
 295 static void kill_urbs(struct wdm_device *desc)
 296 {
 297         /* the order here is essential */
 298         usb_kill_urb(desc->command);
 299         usb_kill_urb(desc->validity);
 300         usb_kill_urb(desc->response);
 301 }
 302
 303 static void free_urbs(struct wdm_device *desc)
 304 {
 305         usb_free_urb(desc->validity);
 306         usb_free_urb(desc->response);
 307         usb_free_urb(desc->command);
 308 }
 309
 310 static void cleanup(struct wdm_device *desc)
 311 {
 312         spin_lock(&wdm_device_list_lock);
 313         list_del(&desc->device_list);
 314         spin_unlock(&wdm_device_list_lock);
 315         kfree(desc->sbuf);
 316         kfree(desc->inbuf);
 317         kfree(desc->orq);
 318         kfree(desc->irq);
 319         kfree(desc->ubuf);
 320         free_urbs(desc);
 321         kfree(desc);
 322 }
 323
 324 static ssize_t wdm_write
 325 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 326 {
 327         u8 *buf;
 328         int rv = -EMSGSIZE, r, we;
 329         struct wdm_device *desc = file->private_data;
 330         struct usb_ctrlrequest *req;
 331
 332         if (count > desc->wMaxCommand)
 333                 count = desc->wMaxCommand;
 334
 335         spin_lock_irq(&desc->iuspin);
 336         we = desc->werr;
 337         desc->werr = 0;
 338         spin_unlock_irq(&desc->iuspin);
 339         if (we < 0)
 340                 return -EIO;
 341
 342         buf = kmalloc(count, GFP_KERNEL);
 343         if (!buf) {
 344                 rv = -ENOMEM;
 345                 goto outnl;
 346         }
 347
 348         r = copy_from_user(buf, buffer, count);
 349         if (r > 0) {
 350                 kfree(buf);
 351                 rv = -EFAULT;
 352                 goto outnl;
 353         }
 354
 355         /* concurrent writes and disconnect */
 356         r = mutex_lock_interruptible(&desc->wlock);
 357         rv = -ERESTARTSYS;
 358         if (r) {
 359                 kfree(buf);
 360                 goto outnl;
 361         }
 362
 363         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 364                 kfree(buf);
 365                 rv = -ENODEV;
 366                 goto outnp;
 367         }
 368
 369         r = usb_autopm_get_interface(desc->intf);
 370         if (r < 0) {
 371                 kfree(buf);
 372                 goto outnp;
 373         }
 374
 375         if (!(file->f_flags & O_NONBLOCK))
 376                 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
 377                                                                 &desc->flags));
 378         else
 379                 if (test_bit(WDM_IN_USE, &desc->flags))
 380                         r = -EAGAIN;
 381
 382         if (test_bit(WDM_RESETTING, &desc->flags))
 383                 r = -EIO;
 384
 385         if (r < 0) {
 386                 kfree(buf);
 387                 goto out;
 388         }
 389
 390         req = desc->orq;
 391         usb_fill_control_urb(
 392                 desc->command,
 393                 interface_to_usbdev(desc->intf),
 394                 /* using common endpoint 0 */
 395                 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
 396                 (unsigned char *)req,
 397                 buf,
 398                 count,
 399                 wdm_out_callback,
 400                 desc
 401         );
 402
 403         req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
 404                              USB_RECIP_INTERFACE);
 405         req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
 406         req->wValue = 0;
 407         req->wIndex = desc->inum;
 408         req->wLength = cpu_to_le16(count);
 409         set_bit(WDM_IN_USE, &desc->flags);
 410         desc->outbuf = buf;
 411
 412         rv = usb_submit_urb(desc->command, GFP_KERNEL);
 413         if (rv < 0) {
 414                 kfree(buf);
 415                 desc->outbuf = NULL;
 416                 clear_bit(WDM_IN_USE, &desc->flags);
 417                 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
 418         } else {
 419                 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
 420                         req->wIndex);
 421         }
 422 out:
 423         usb_autopm_put_interface(desc->intf);
 424 outnp:
 425         mutex_unlock(&desc->wlock);
 426 outnl:
 427         return rv < 0 ? rv : count;
 428 }
 429
 430 static ssize_t wdm_read
 431 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 432 {
 433         int rv, cntr;
 434         int i = 0;
 435         struct wdm_device *desc = file->private_data;
 436
 437
 438         rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
 439         if (rv < 0)
 440                 return -ERESTARTSYS;
 441
 442         cntr = ACCESS_ONCE(desc->length);
 443         if (cntr == 0) {
 444                 desc->read = 0;
 445 retry:
 446                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 447                         rv = -ENODEV;
 448                         goto err;
 449                 }
 450                 i++;
 451                 if (file->f_flags & O_NONBLOCK) {
 452                         if (!test_bit(WDM_READ, &desc->flags)) {
 453                                 rv = cntr ? cntr : -EAGAIN;
 454                                 goto err;
 455                         }
 456                         rv = 0;
 457                 } else {
 458                         rv = wait_event_interruptible(desc->wait,
 459                                 test_bit(WDM_READ, &desc->flags));
 460                 }
 461
 462                 /* may have happened while we slept */
 463                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 464                         rv = -ENODEV;
 465                         goto err;
 466                 }
 467                 if (test_bit(WDM_RESETTING, &desc->flags)) {
 468                         rv = -EIO;
 469                         goto err;
 470                 }
 471                 usb_mark_last_busy(interface_to_usbdev(desc->intf));
 472                 if (rv < 0) {
 473                         rv = -ERESTARTSYS;
 474                         goto err;
 475                 }
 476
 477                 spin_lock_irq(&desc->iuspin);
 478
 479                 if (desc->rerr) { /* read completed, error happened */
 480                         desc->rerr = 0;
 481                         spin_unlock_irq(&desc->iuspin);
 482                         rv = -EIO;
 483                         goto err;
 484                 }
 485                 /*
 486                  * recheck whether we've lost the race
 487                  * against the completion handler
 488                  */
 489                 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
 490                         spin_unlock_irq(&desc->iuspin);
 491                         goto retry;
 492                 }
 493                 if (!desc->reslength) { /* zero length read */
 494                         spin_unlock_irq(&desc->iuspin);
 495                         goto retry;
 496                 }
 497                 cntr = desc->length;
 498                 spin_unlock_irq(&desc->iuspin);
 499         }
 500
 501         if (cntr > count)
 502                 cntr = count;
 503         rv = copy_to_user(buffer, desc->ubuf, cntr);
 504         if (rv > 0) {
 505                 rv = -EFAULT;
 506                 goto err;
 507         }
 508
 509         spin_lock_irq(&desc->iuspin);
 510
 511         for (i = 0; i < desc->length - cntr; i++)
 512                 desc->ubuf[i] = desc->ubuf[i + cntr];
 513
 514         desc->length -= cntr;
 515         /* in case we had outstanding data */
 516         if (!desc->length)
 517                 clear_bit(WDM_READ, &desc->flags);
 518
 519         spin_unlock_irq(&desc->iuspin);
 520
 521         rv = cntr;
 522
 523 err:
 524         mutex_unlock(&desc->rlock);
 525         return rv;
 526 }
 527
 528 static int wdm_flush(struct file *file, fl_owner_t id)
 529 {
 530         struct wdm_device *desc = file->private_data;
 531
 532         wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
 533         if (desc->werr < 0)
 534                 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
 535                         desc->werr);
 536
 537         return desc->werr;
 538 }
 539
 540 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
 541 {
 542         struct wdm_device *desc = file->private_data;
 543         unsigned long flags;
 544         unsigned int mask = 0;
 545
 546         spin_lock_irqsave(&desc->iuspin, flags);
 547         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 548                 mask = POLLERR;
 549                 spin_unlock_irqrestore(&desc->iuspin, flags);
 550                 goto desc_out;
 551         }
 552         if (test_bit(WDM_READ, &desc->flags))
 553                 mask = POLLIN | POLLRDNORM;
 554         if (desc->rerr || desc->werr)
 555                 mask |= POLLERR;
 556         if (!test_bit(WDM_IN_USE, &desc->flags))
 557                 mask |= POLLOUT | POLLWRNORM;
 558         spin_unlock_irqrestore(&desc->iuspin, flags);
 559
 560         poll_wait(file, &desc->wait, wait);
 561
 562 desc_out:
 563         return mask;
 564 }
 565
 566 static int wdm_open(struct inode *inode, struct file *file)
 567 {
 568         int minor = iminor(inode);
 569         int rv = -ENODEV;
 570         struct usb_interface *intf;
 571         struct wdm_device *desc;
 572
 573         mutex_lock(&wdm_mutex);
 574         desc = wdm_find_device_by_minor(minor);
 575         if (!desc)
 576                 goto out;
 577
 578         intf = desc->intf;
 579         if (test_bit(WDM_DISCONNECTING, &desc->flags))
 580                 goto out;
 581         file->private_data = desc;
 582
 583         rv = usb_autopm_get_interface(desc->intf);
 584         if (rv < 0) {
 585                 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
 586                 goto out;
 587         }
 588
 589         /* using write lock to protect desc->count */
 590         mutex_lock(&desc->wlock);
 591         if (!desc->count++) {
 592                 desc->werr = 0;
 593                 desc->rerr = 0;
 594                 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
 595                 if (rv < 0) {
 596                         desc->count--;
 597                         dev_err(&desc->intf->dev,
 598                                 "Error submitting int urb - %d\n", rv);
 599                 }
 600         } else {
 601                 rv = 0;
 602         }
 603         mutex_unlock(&desc->wlock);
 604         if (desc->count == 1)
 605                 desc->manage_power(intf, 1);
 606         usb_autopm_put_interface(desc->intf);
 607 out:
 608         mutex_unlock(&wdm_mutex);
 609         return rv;
 610 }
 611
 612 static int wdm_release(struct inode *inode, struct file *file)
 613 {
 614         struct wdm_device *desc = file->private_data;
 615
 616         mutex_lock(&wdm_mutex);
 617
 618         /* using write lock to protect desc->count */
 619         mutex_lock(&desc->wlock);
 620         desc->count--;
 621         mutex_unlock(&desc->wlock);
 622
 623         if (!desc->count) {
 624                 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
 625                 kill_urbs(desc);
 626                 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 627                         desc->manage_power(desc->intf, 0);
 628         }
 629         mutex_unlock(&wdm_mutex);
 630         return 0;
 631 }
 632
 633 static const struct file_operations wdm_fops = {
 634         .owner =        THIS_MODULE,
 635         .read =         wdm_read,
 636         .write =        wdm_write,
 637         .open =         wdm_open,
 638         .flush =        wdm_flush,
 639         .release =      wdm_release,
 640         .poll =         wdm_poll,
 641         .llseek =       noop_llseek,
 642 };
 643
 644 static struct usb_class_driver wdm_class = {
 645         .name =         "cdc-wdm%d",
 646         .fops =         &wdm_fops,
 647         .minor_base =   WDM_MINOR_BASE,
 648 };
 649
 650 /* --- error handling --- */
 651 static void wdm_rxwork(struct work_struct *work)
 652 {
 653         struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
 654         unsigned long flags;
 655         int rv;
 656
 657         spin_lock_irqsave(&desc->iuspin, flags);
 658         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 659                 spin_unlock_irqrestore(&desc->iuspin, flags);
 660         } else {
 661                 spin_unlock_irqrestore(&desc->iuspin, flags);
 662                 rv = usb_submit_urb(desc->response, GFP_KERNEL);
 663                 if (rv < 0 && rv != -EPERM) {
 664                         spin_lock_irqsave(&desc->iuspin, flags);
 665                         if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 666                                 schedule_work(&desc->rxwork);
 667                         spin_unlock_irqrestore(&desc->iuspin, flags);
 668                 }
 669         }
 670 }
 671
 672 /* --- hotplug --- */
 673
 674 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep,
 675                 u16 bufsize, int (*manage_power)(struct usb_interface *, int))
 676 {
 677         int rv = -ENOMEM;
 678         struct wdm_device *desc;
 679
 680         desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
 681         if (!desc)
 682                 goto out;
 683         INIT_LIST_HEAD(&desc->device_list);
 684         mutex_init(&desc->rlock);
 685         mutex_init(&desc->wlock);
 686         spin_lock_init(&desc->iuspin);
 687         init_waitqueue_head(&desc->wait);
 688         desc->wMaxCommand = bufsize;
 689         /* this will be expanded and needed in hardware endianness */
 690         desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
 691         desc->intf = intf;
 692         INIT_WORK(&desc->rxwork, wdm_rxwork);
 693
 694         rv = -EINVAL;
 695         if (!usb_endpoint_is_int_in(ep))
 696                 goto err;
 697
 698         desc->wMaxPacketSize = usb_endpoint_maxp(ep);
 699
 700         desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 701         if (!desc->orq)
 702                 goto err;
 703         desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 704         if (!desc->irq)
 705                 goto err;
 706
 707         desc->validity = usb_alloc_urb(0, GFP_KERNEL);
 708         if (!desc->validity)
 709                 goto err;
 710
 711         desc->response = usb_alloc_urb(0, GFP_KERNEL);
 712         if (!desc->response)
 713                 goto err;
 714
 715         desc->command = usb_alloc_urb(0, GFP_KERNEL);
 716         if (!desc->command)
 717                 goto err;
 718
 719         desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
 720         if (!desc->ubuf)
 721                 goto err;
 722
 723         desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
 724         if (!desc->sbuf)
 725                 goto err;
 726
 727         desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
 728         if (!desc->inbuf)
 729                 goto err;
 730
 731         usb_fill_int_urb(
 732                 desc->validity,
 733                 interface_to_usbdev(intf),
 734                 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
 735                 desc->sbuf,
 736                 desc->wMaxPacketSize,
 737                 wdm_int_callback,
 738                 desc,
 739                 ep->bInterval
 740         );
 741
 742         desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
 743         desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
 744         desc->irq->wValue = 0;
 745         desc->irq->wIndex = desc->inum;
 746         desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
 747
 748         usb_fill_control_urb(
 749                 desc->response,
 750                 interface_to_usbdev(intf),
 751                 /* using common endpoint 0 */
 752                 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
 753                 (unsigned char *)desc->irq,
 754                 desc->inbuf,
 755                 desc->wMaxCommand,
 756                 wdm_in_callback,
 757                 desc
 758         );
 759
 760         desc->manage_power = manage_power;
 761
 762         spin_lock(&wdm_device_list_lock);
 763         list_add(&desc->device_list, &wdm_device_list);
 764         spin_unlock(&wdm_device_list_lock);
 765
 766         rv = usb_register_dev(intf, &wdm_class);
 767         if (rv < 0)
 768                 goto err;
 769         else
 770                 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
 771 out:
 772         return rv;
 773 err:
 774         cleanup(desc);
 775         return rv;
 776 }
 777
 778 static int wdm_manage_power(struct usb_interface *intf, int on)
 779 {
 780         /* need autopm_get/put here to ensure the usbcore sees the new value */
 781         int rv = usb_autopm_get_interface(intf);
 782         if (rv < 0)
 783                 goto err;
 784
 785         intf->needs_remote_wakeup = on;
 786         usb_autopm_put_interface(intf);
 787 err:
 788         return rv;
 789 }
 790
 791 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
 792 {
 793         int rv = -EINVAL;
 794         struct usb_host_interface *iface;
 795         struct usb_endpoint_descriptor *ep;
 796         struct usb_cdc_dmm_desc *dmhd;
 797         u8 *buffer = intf->altsetting->extra;
 798         int buflen = intf->altsetting->extralen;
 799         u16 maxcom = WDM_DEFAULT_BUFSIZE;
 800
 801         if (!buffer)
 802                 goto err;
 803         while (buflen > 2) {
 804                 if (buffer[1] != USB_DT_CS_INTERFACE) {
 805                         dev_err(&intf->dev, "skipping garbage\n");
 806                         goto next_desc;
 807                 }
 808
 809                 switch (buffer[2]) {
 810                 case USB_CDC_HEADER_TYPE:
 811                         break;
 812                 case USB_CDC_DMM_TYPE:
 813                         dmhd = (struct usb_cdc_dmm_desc *)buffer;
 814                         maxcom = le16_to_cpu(dmhd->wMaxCommand);
 815                         dev_dbg(&intf->dev,
 816                                 "Finding maximum buffer length: %d", maxcom);
 817                         break;
 818                 default:
 819                         dev_err(&intf->dev,
 820                                 "Ignoring extra header, type %d, length %d\n",
 821                                 buffer[2], buffer[0]);
 822                         break;
 823                 }
 824 next_desc:
 825                 buflen -= buffer[0];
 826                 buffer += buffer[0];
 827         }
 828
 829         iface = intf->cur_altsetting;
 830         if (iface->desc.bNumEndpoints != 1)
 831                 goto err;
 832         ep = &iface->endpoint[0].desc;
 833
 834         rv = wdm_create(intf, ep, maxcom, &wdm_manage_power);
 835
 836 err:
 837         return rv;
 838 }
 839
 840 /**
 841  * usb_cdc_wdm_register - register a WDM subdriver
 842  * @intf: usb interface the subdriver will associate with
 843  * @ep: interrupt endpoint to monitor for notifications
 844  * @bufsize: maximum message size to support for read/write
 845  *
 846  * Create WDM usb class character device and associate it with intf
 847  * without binding, allowing another driver to manage the interface.
 848  *
 849  * The subdriver will manage the given interrupt endpoint exclusively
 850  * and will issue control requests referring to the given intf. It
 851  * will otherwise avoid interferring, and in particular not do
 852  * usb_set_intfdata/usb_get_intfdata on intf.
 853  *
 854  * The return value is a pointer to the subdriver's struct usb_driver.
 855  * The registering driver is responsible for calling this subdriver's
 856  * disconnect, suspend, resume, pre_reset and post_reset methods from
 857  * its own.
 858  */
 859 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf,
 860                                         struct usb_endpoint_descriptor *ep,
 861                                         int bufsize,
 862                                         int (*manage_power)(struct usb_interface *, int))
 863 {
 864         int rv = -EINVAL;
 865
 866         rv = wdm_create(intf, ep, bufsize, manage_power);
 867         if (rv < 0)
 868                 goto err;
 869
 870         return &wdm_driver;
 871 err:
 872         return ERR_PTR(rv);
 873 }
 874 EXPORT_SYMBOL(usb_cdc_wdm_register);
 875
 876 static void wdm_disconnect(struct usb_interface *intf)
 877 {
 878         struct wdm_device *desc;
 879         unsigned long flags;
 880
 881         usb_deregister_dev(intf, &wdm_class);
 882         desc = wdm_find_device(intf);
 883         mutex_lock(&wdm_mutex);
 884
 885         /* the spinlock makes sure no new urbs are generated in the callbacks */
 886         spin_lock_irqsave(&desc->iuspin, flags);
 887         set_bit(WDM_DISCONNECTING, &desc->flags);
 888         set_bit(WDM_READ, &desc->flags);
 889         /* to terminate pending flushes */
 890         clear_bit(WDM_IN_USE, &desc->flags);
 891         spin_unlock_irqrestore(&desc->iuspin, flags);
 892         wake_up_all(&desc->wait);
 893         mutex_lock(&desc->rlock);
 894         mutex_lock(&desc->wlock);
 895         kill_urbs(desc);
 896         cancel_work_sync(&desc->rxwork);
 897         mutex_unlock(&desc->wlock);
 898         mutex_unlock(&desc->rlock);
 899         if (!desc->count)
 900                 cleanup(desc);
 901         mutex_unlock(&wdm_mutex);
 902 }
 903
 904 #ifdef CONFIG_PM
 905 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
 906 {
 907         struct wdm_device *desc = wdm_find_device(intf);
 908         int rv = 0;
 909
 910         dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
 911
 912         /* if this is an autosuspend the caller does the locking */
 913         if (!PMSG_IS_AUTO(message)) {
 914                 mutex_lock(&desc->rlock);
 915                 mutex_lock(&desc->wlock);
 916         }
 917         spin_lock_irq(&desc->iuspin);
 918
 919         if (PMSG_IS_AUTO(message) &&
 920                         (test_bit(WDM_IN_USE, &desc->flags)
 921                         || test_bit(WDM_RESPONDING, &desc->flags))) {
 922                 spin_unlock_irq(&desc->iuspin);
 923                 rv = -EBUSY;
 924         } else {
 925
 926                 set_bit(WDM_SUSPENDING, &desc->flags);
 927                 spin_unlock_irq(&desc->iuspin);
 928                 /* callback submits work - order is essential */
 929                 kill_urbs(desc);
 930                 cancel_work_sync(&desc->rxwork);
 931         }
 932         if (!PMSG_IS_AUTO(message)) {
 933                 mutex_unlock(&desc->wlock);
 934                 mutex_unlock(&desc->rlock);
 935         }
 936
 937         return rv;
 938 }
 939 #endif
 940
 941 static int recover_from_urb_loss(struct wdm_device *desc)
 942 {
 943         int rv = 0;
 944
 945         if (desc->count) {
 946                 rv = usb_submit_urb(desc->validity, GFP_NOIO);
 947                 if (rv < 0)
 948                         dev_err(&desc->intf->dev,
 949                                 "Error resume submitting int urb - %d\n", rv);
 950         }
 951         return rv;
 952 }
 953
 954 #ifdef CONFIG_PM
 955 static int wdm_resume(struct usb_interface *intf)
 956 {
 957         struct wdm_device *desc = wdm_find_device(intf);
 958         int rv;
 959
 960         dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
 961
 962         clear_bit(WDM_SUSPENDING, &desc->flags);
 963         rv = recover_from_urb_loss(desc);
 964
 965         return rv;
 966 }
 967 #endif
 968
 969 static int wdm_pre_reset(struct usb_interface *intf)
 970 {
 971         struct wdm_device *desc = wdm_find_device(intf);
 972
 973         /*
 974          * we notify everybody using poll of
 975          * an exceptional situation
 976          * must be done before recovery lest a spontaneous
 977          * message from the device is lost
 978          */
 979         spin_lock_irq(&desc->iuspin);
 980         set_bit(WDM_RESETTING, &desc->flags);   /* inform read/write */
 981         set_bit(WDM_READ, &desc->flags);        /* unblock read */
 982         clear_bit(WDM_IN_USE, &desc->flags);    /* unblock write */
 983         desc->rerr = -EINTR;
 984         spin_unlock_irq(&desc->iuspin);
 985         wake_up_all(&desc->wait);
 986         mutex_lock(&desc->rlock);
 987         mutex_lock(&desc->wlock);
 988         kill_urbs(desc);
 989         cancel_work_sync(&desc->rxwork);
 990         return 0;
 991 }
 992
 993 static int wdm_post_reset(struct usb_interface *intf)
 994 {
 995         struct wdm_device *desc = wdm_find_device(intf);
 996         int rv;
 997
 998         clear_bit(WDM_RESETTING, &desc->flags);
 999         rv = recover_from_urb_loss(desc);
1000         mutex_unlock(&desc->wlock);
1001         mutex_unlock(&desc->rlock);
1002         return 0;
1003 }
1004
1005 static struct usb_driver wdm_driver = {
1006         .name =         "cdc_wdm",
1007         .probe =        wdm_probe,
1008         .disconnect =   wdm_disconnect,
1009 #ifdef CONFIG_PM
1010         .suspend =      wdm_suspend,
1011         .resume =       wdm_resume,
1012         .reset_resume = wdm_resume,
1013 #endif
1014         .pre_reset =    wdm_pre_reset,
1015         .post_reset =   wdm_post_reset,
1016         .id_table =     wdm_ids,
1017         .supports_autosuspend = 1,
1018 };
1019
1020 module_usb_driver(wdm_driver);
1021
1022 MODULE_AUTHOR(DRIVER_AUTHOR);
1023 MODULE_DESCRIPTION(DRIVER_DESC);
1024 MODULE_LICENSE("GPL");