drivers/usb/gadget/legacy/inode.c

   1 /*
   2  * inode.c -- user mode filesystem api for usb gadget controllers
   3  *
   4  * Copyright (C) 2003-2004 David Brownell
   5  * Copyright (C) 2003 Agilent Technologies
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  */
  12
  13
  14 /* #define VERBOSE_DEBUG */
  15
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/fs.h>
  19 #include <linux/pagemap.h>
  20 #include <linux/uts.h>
  21 #include <linux/wait.h>
  22 #include <linux/compiler.h>
  23 #include <asm/uaccess.h>
  24 #include <linux/sched.h>
  25 #include <linux/slab.h>
  26 #include <linux/poll.h>
  27 #include <linux/mmu_context.h>
  28 #include <linux/aio.h>
  29
  30 #include <linux/device.h>
  31 #include <linux/moduleparam.h>
  32
  33 #include <linux/usb/gadgetfs.h>
  34 #include <linux/usb/gadget.h>
  35
  36
  37 /*
  38  * The gadgetfs API maps each endpoint to a file descriptor so that you
  39  * can use standard synchronous read/write calls for I/O.  There's some
  40  * O_NONBLOCK and O_ASYNC/FASYNC style i/o support.  Example usermode
  41  * drivers show how this works in practice.  You can also use AIO to
  42  * eliminate I/O gaps between requests, to help when streaming data.
  43  *
  44  * Key parts that must be USB-specific are protocols defining how the
  45  * read/write operations relate to the hardware state machines.  There
  46  * are two types of files.  One type is for the device, implementing ep0.
  47  * The other type is for each IN or OUT endpoint.  In both cases, the
  48  * user mode driver must configure the hardware before using it.
  49  *
  50  * - First, dev_config() is called when /dev/gadget/$CHIP is configured
  51  *   (by writing configuration and device descriptors).  Afterwards it
  52  *   may serve as a source of device events, used to handle all control
  53  *   requests other than basic enumeration.
  54  *
  55  * - Then, after a SET_CONFIGURATION control request, ep_config() is
  56  *   called when each /dev/gadget/ep* file is configured (by writing
  57  *   endpoint descriptors).  Afterwards these files are used to write()
  58  *   IN data or to read() OUT data.  To halt the endpoint, a "wrong
  59  *   direction" request is issued (like reading an IN endpoint).
  60  *
  61  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
  62  * not possible on all hardware.  For example, precise fault handling with
  63  * respect to data left in endpoint fifos after aborted operations; or
  64  * selective clearing of endpoint halts, to implement SET_INTERFACE.
  65  */
  66
  67 #define DRIVER_DESC     "USB Gadget filesystem"
  68 #define DRIVER_VERSION  "24 Aug 2004"
  69
  70 static const char driver_desc [] = DRIVER_DESC;
  71 static const char shortname [] = "gadgetfs";
  72
  73 MODULE_DESCRIPTION (DRIVER_DESC);
  74 MODULE_AUTHOR ("David Brownell");
  75 MODULE_LICENSE ("GPL");
  76
  77 static int ep_open(struct inode *, struct file *);
  78
  79
  80 /*----------------------------------------------------------------------*/
  81
  82 #define GADGETFS_MAGIC          0xaee71ee7
  83
  84 /* /dev/gadget/$CHIP represents ep0 and the whole device */
  85 enum ep0_state {
  86         /* DISBLED is the initial state.
  87          */
  88         STATE_DEV_DISABLED = 0,
  89
  90         /* Only one open() of /dev/gadget/$CHIP; only one file tracks
  91          * ep0/device i/o modes and binding to the controller.  Driver
  92          * must always write descriptors to initialize the device, then
  93          * the device becomes UNCONNECTED until enumeration.
  94          */
  95         STATE_DEV_OPENED,
  96
  97         /* From then on, ep0 fd is in either of two basic modes:
  98          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
  99          * - SETUP: read/write will transfer control data and succeed;
 100          *   or if "wrong direction", performs protocol stall
 101          */
 102         STATE_DEV_UNCONNECTED,
 103         STATE_DEV_CONNECTED,
 104         STATE_DEV_SETUP,
 105
 106         /* UNBOUND means the driver closed ep0, so the device won't be
 107          * accessible again (DEV_DISABLED) until all fds are closed.
 108          */
 109         STATE_DEV_UNBOUND,
 110 };
 111
 112 /* enough for the whole queue: most events invalidate others */
 113 #define N_EVENT                 5
 114
 115 struct dev_data {
 116         spinlock_t                      lock;
 117         atomic_t                        count;
 118         enum ep0_state                  state;          /* P: lock */
 119         struct usb_gadgetfs_event       event [N_EVENT];
 120         unsigned                        ev_next;
 121         struct fasync_struct            *fasync;
 122         u8                              current_config;
 123
 124         /* drivers reading ep0 MUST handle control requests (SETUP)
 125          * reported that way; else the host will time out.
 126          */
 127         unsigned                        usermode_setup : 1,
 128                                         setup_in : 1,
 129                                         setup_can_stall : 1,
 130                                         setup_out_ready : 1,
 131                                         setup_out_error : 1,
 132                                         setup_abort : 1;
 133         unsigned                        setup_wLength;
 134
 135         /* the rest is basically write-once */
 136         struct usb_config_descriptor    *config, *hs_config;
 137         struct usb_device_descriptor    *dev;
 138         struct usb_request              *req;
 139         struct usb_gadget               *gadget;
 140         struct list_head                epfiles;
 141         void                            *buf;
 142         wait_queue_head_t               wait;
 143         struct super_block              *sb;
 144         struct dentry                   *dentry;
 145
 146         /* except this scratch i/o buffer for ep0 */
 147         u8                              rbuf [256];
 148 };
 149
 150 static inline void get_dev (struct dev_data *data)
 151 {
 152         atomic_inc (&data->count);
 153 }
 154
 155 static void put_dev (struct dev_data *data)
 156 {
 157         if (likely (!atomic_dec_and_test (&data->count)))
 158                 return;
 159         /* needs no more cleanup */
 160         BUG_ON (waitqueue_active (&data->wait));
 161         kfree (data);
 162 }
 163
 164 static struct dev_data *dev_new (void)
 165 {
 166         struct dev_data         *dev;
 167
 168         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 169         if (!dev)
 170                 return NULL;
 171         dev->state = STATE_DEV_DISABLED;
 172         atomic_set (&dev->count, 1);
 173         spin_lock_init (&dev->lock);
 174         INIT_LIST_HEAD (&dev->epfiles);
 175         init_waitqueue_head (&dev->wait);
 176         return dev;
 177 }
 178
 179 /*----------------------------------------------------------------------*/
 180
 181 /* other /dev/gadget/$ENDPOINT files represent endpoints */
 182 enum ep_state {
 183         STATE_EP_DISABLED = 0,
 184         STATE_EP_READY,
 185         STATE_EP_ENABLED,
 186         STATE_EP_UNBOUND,
 187 };
 188
 189 struct ep_data {
 190         struct mutex                    lock;
 191         enum ep_state                   state;
 192         atomic_t                        count;
 193         struct dev_data                 *dev;
 194         /* must hold dev->lock before accessing ep or req */
 195         struct usb_ep                   *ep;
 196         struct usb_request              *req;
 197         ssize_t                         status;
 198         char                            name [16];
 199         struct usb_endpoint_descriptor  desc, hs_desc;
 200         struct list_head                epfiles;
 201         wait_queue_head_t               wait;
 202         struct dentry                   *dentry;
 203 };
 204
 205 static inline void get_ep (struct ep_data *data)
 206 {
 207         atomic_inc (&data->count);
 208 }
 209
 210 static void put_ep (struct ep_data *data)
 211 {
 212         if (likely (!atomic_dec_and_test (&data->count)))
 213                 return;
 214         put_dev (data->dev);
 215         /* needs no more cleanup */
 216         BUG_ON (!list_empty (&data->epfiles));
 217         BUG_ON (waitqueue_active (&data->wait));
 218         kfree (data);
 219 }
 220
 221 /*----------------------------------------------------------------------*/
 222
 223 /* most "how to use the hardware" policy choices are in userspace:
 224  * mapping endpoint roles (which the driver needs) to the capabilities
 225  * which the usb controller has.  most of those capabilities are exposed
 226  * implicitly, starting with the driver name and then endpoint names.
 227  */
 228
 229 static const char *CHIP;
 230
 231 /*----------------------------------------------------------------------*/
 232
 233 /* NOTE:  don't use dev_printk calls before binding to the gadget
 234  * at the end of ep0 configuration, or after unbind.
 235  */
 236
 237 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
 238 #define xprintk(d,level,fmt,args...) \
 239         printk(level "%s: " fmt , shortname , ## args)
 240
 241 #ifdef DEBUG
 242 #define DBG(dev,fmt,args...) \
 243         xprintk(dev , KERN_DEBUG , fmt , ## args)
 244 #else
 245 #define DBG(dev,fmt,args...) \
 246         do { } while (0)
 247 #endif /* DEBUG */
 248
 249 #ifdef VERBOSE_DEBUG
 250 #define VDEBUG  DBG
 251 #else
 252 #define VDEBUG(dev,fmt,args...) \
 253         do { } while (0)
 254 #endif /* DEBUG */
 255
 256 #define ERROR(dev,fmt,args...) \
 257         xprintk(dev , KERN_ERR , fmt , ## args)
 258 #define INFO(dev,fmt,args...) \
 259         xprintk(dev , KERN_INFO , fmt , ## args)
 260
 261
 262 /*----------------------------------------------------------------------*/
 263
 264 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 265  *
 266  * After opening, configure non-control endpoints.  Then use normal
 267  * stream read() and write() requests; and maybe ioctl() to get more
 268  * precise FIFO status when recovering from cancellation.
 269  */
 270
 271 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 272 {
 273         struct ep_data  *epdata = ep->driver_data;
 274
 275         if (!req->context)
 276                 return;
 277         if (req->status)
 278                 epdata->status = req->status;
 279         else
 280                 epdata->status = req->actual;
 281         complete ((struct completion *)req->context);
 282 }
 283
 284 /* tasklock endpoint, returning when it's connected.
 285  * still need dev->lock to use epdata->ep.
 286  */
 287 static int
 288 get_ready_ep (unsigned f_flags, struct ep_data *epdata, bool is_write)
 289 {
 290         int     val;
 291
 292         if (f_flags & O_NONBLOCK) {
 293                 if (!mutex_trylock(&epdata->lock))
 294                         goto nonblock;
 295                 if (epdata->state != STATE_EP_ENABLED &&
 296                     (!is_write || epdata->state != STATE_EP_READY)) {
 297                         mutex_unlock(&epdata->lock);
 298 nonblock:
 299                         val = -EAGAIN;
 300                 } else
 301                         val = 0;
 302                 return val;
 303         }
 304
 305         val = mutex_lock_interruptible(&epdata->lock);
 306         if (val < 0)
 307                 return val;
 308
 309         switch (epdata->state) {
 310         case STATE_EP_ENABLED:
 311                 return 0;
 312         case STATE_EP_READY:                    /* not configured yet */
 313                 if (is_write)
 314                         return 0;
 315                 // FALLTHRU
 316         case STATE_EP_UNBOUND:                  /* clean disconnect */
 317                 break;
 318         // case STATE_EP_DISABLED:              /* "can't happen" */
 319         default:                                /* error! */
 320                 pr_debug ("%s: ep %p not available, state %d\n",
 321                                 shortname, epdata, epdata->state);
 322         }
 323         mutex_unlock(&epdata->lock);
 324         return -ENODEV;
 325 }
 326
 327 static ssize_t
 328 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 329 {
 330         DECLARE_COMPLETION_ONSTACK (done);
 331         int value;
 332
 333         spin_lock_irq (&epdata->dev->lock);
 334         if (likely (epdata->ep != NULL)) {
 335                 struct usb_request      *req = epdata->req;
 336
 337                 req->context = &done;
 338                 req->complete = epio_complete;
 339                 req->buf = buf;
 340                 req->length = len;
 341                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 342         } else
 343                 value = -ENODEV;
 344         spin_unlock_irq (&epdata->dev->lock);
 345
 346         if (likely (value == 0)) {
 347                 value = wait_event_interruptible (done.wait, done.done);
 348                 if (value != 0) {
 349                         spin_lock_irq (&epdata->dev->lock);
 350                         if (likely (epdata->ep != NULL)) {
 351                                 DBG (epdata->dev, "%s i/o interrupted\n",
 352                                                 epdata->name);
 353                                 usb_ep_dequeue (epdata->ep, epdata->req);
 354                                 spin_unlock_irq (&epdata->dev->lock);
 355
 356                                 wait_event (done.wait, done.done);
 357                                 if (epdata->status == -ECONNRESET)
 358                                         epdata->status = -EINTR;
 359                         } else {
 360                                 spin_unlock_irq (&epdata->dev->lock);
 361
 362                                 DBG (epdata->dev, "endpoint gone\n");
 363                                 epdata->status = -ENODEV;
 364                         }
 365                 }
 366                 return epdata->status;
 367         }
 368         return value;
 369 }
 370
 371 static int
 372 ep_release (struct inode *inode, struct file *fd)
 373 {
 374         struct ep_data          *data = fd->private_data;
 375         int value;
 376
 377         value = mutex_lock_interruptible(&data->lock);
 378         if (value < 0)
 379                 return value;
 380
 381         /* clean up if this can be reopened */
 382         if (data->state != STATE_EP_UNBOUND) {
 383                 data->state = STATE_EP_DISABLED;
 384                 data->desc.bDescriptorType = 0;
 385                 data->hs_desc.bDescriptorType = 0;
 386                 usb_ep_disable(data->ep);
 387         }
 388         mutex_unlock(&data->lock);
 389         put_ep (data);
 390         return 0;
 391 }
 392
 393 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
 394 {
 395         struct ep_data          *data = fd->private_data;
 396         int                     status;
 397
 398         if ((status = get_ready_ep (fd->f_flags, data, false)) < 0)
 399                 return status;
 400
 401         spin_lock_irq (&data->dev->lock);
 402         if (likely (data->ep != NULL)) {
 403                 switch (code) {
 404                 case GADGETFS_FIFO_STATUS:
 405                         status = usb_ep_fifo_status (data->ep);
 406                         break;
 407                 case GADGETFS_FIFO_FLUSH:
 408                         usb_ep_fifo_flush (data->ep);
 409                         break;
 410                 case GADGETFS_CLEAR_HALT:
 411                         status = usb_ep_clear_halt (data->ep);
 412                         break;
 413                 default:
 414                         status = -ENOTTY;
 415                 }
 416         } else
 417                 status = -ENODEV;
 418         spin_unlock_irq (&data->dev->lock);
 419         mutex_unlock(&data->lock);
 420         return status;
 421 }
 422
 423 /*----------------------------------------------------------------------*/
 424
 425 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 426
 427 struct kiocb_priv {
 428         struct usb_request      *req;
 429         struct ep_data          *epdata;
 430         struct kiocb            *iocb;
 431         struct mm_struct        *mm;
 432         struct work_struct      work;
 433         void                    *buf;
 434         struct iov_iter         to;
 435         const void              *to_free;
 436         unsigned                actual;
 437 };
 438
 439 static int ep_aio_cancel(struct kiocb *iocb)
 440 {
 441         struct kiocb_priv       *priv = iocb->private;
 442         struct ep_data          *epdata;
 443         int                     value;
 444
 445         local_irq_disable();
 446         epdata = priv->epdata;
 447         // spin_lock(&epdata->dev->lock);
 448         if (likely(epdata && epdata->ep && priv->req))
 449                 value = usb_ep_dequeue (epdata->ep, priv->req);
 450         else
 451                 value = -EINVAL;
 452         // spin_unlock(&epdata->dev->lock);
 453         local_irq_enable();
 454
 455         return value;
 456 }
 457
 458 static void ep_user_copy_worker(struct work_struct *work)
 459 {
 460         struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work);
 461         struct mm_struct *mm = priv->mm;
 462         struct kiocb *iocb = priv->iocb;
 463         size_t ret;
 464
 465         use_mm(mm);
 466         ret = copy_to_iter(priv->buf, priv->actual, &priv->to);
 467         unuse_mm(mm);
 468         if (!ret)
 469                 ret = -EFAULT;
 470
 471         /* completing the iocb can drop the ctx and mm, don't touch mm after */
 472         aio_complete(iocb, ret, ret);
 473
 474         kfree(priv->buf);
 475         kfree(priv->to_free);
 476         kfree(priv);
 477 }
 478
 479 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 480 {
 481         struct kiocb            *iocb = req->context;
 482         struct kiocb_priv       *priv = iocb->private;
 483         struct ep_data          *epdata = priv->epdata;
 484
 485         /* lock against disconnect (and ideally, cancel) */
 486         spin_lock(&epdata->dev->lock);
 487         priv->req = NULL;
 488         priv->epdata = NULL;
 489
 490         /* if this was a write or a read returning no data then we
 491          * don't need to copy anything to userspace, so we can
 492          * complete the aio request immediately.
 493          */
 494         if (priv->to_free == NULL || unlikely(req->actual == 0)) {
 495                 kfree(req->buf);
 496                 kfree(priv->to_free);
 497                 kfree(priv);
 498                 iocb->private = NULL;
 499                 /* aio_complete() reports bytes-transferred _and_ faults */
 500                 aio_complete(iocb, req->actual ? req->actual : req->status,
 501                                 req->status);
 502         } else {
 503                 /* ep_copy_to_user() won't report both; we hide some faults */
 504                 if (unlikely(0 != req->status))
 505                         DBG(epdata->dev, "%s fault %d len %d\n",
 506                                 ep->name, req->status, req->actual);
 507
 508                 priv->buf = req->buf;
 509                 priv->actual = req->actual;
 510                 INIT_WORK(&priv->work, ep_user_copy_worker);
 511                 schedule_work(&priv->work);
 512         }
 513         spin_unlock(&epdata->dev->lock);
 514
 515         usb_ep_free_request(ep, req);
 516         put_ep(epdata);
 517 }
 518
 519 static ssize_t ep_aio(struct kiocb *iocb,
 520                       struct kiocb_priv *priv,
 521                       struct ep_data *epdata,
 522                       char *buf,
 523                       size_t len)
 524 {
 525         struct usb_request *req;
 526         ssize_t value;
 527
 528         iocb->private = priv;
 529         priv->iocb = iocb;
 530
 531         kiocb_set_cancel_fn(iocb, ep_aio_cancel);
 532         get_ep(epdata);
 533         priv->epdata = epdata;
 534         priv->actual = 0;
 535         priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */
 536
 537         /* each kiocb is coupled to one usb_request, but we can't
 538          * allocate or submit those if the host disconnected.
 539          */
 540         spin_lock_irq(&epdata->dev->lock);
 541         value = -ENODEV;
 542         if (unlikely(epdata->ep))
 543                 goto fail;
 544
 545         req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 546         value = -ENOMEM;
 547         if (unlikely(!req))
 548                 goto fail;
 549
 550         priv->req = req;
 551         req->buf = buf;
 552         req->length = len;
 553         req->complete = ep_aio_complete;
 554         req->context = iocb;
 555         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 556         if (unlikely(0 != value)) {
 557                 usb_ep_free_request(epdata->ep, req);
 558                 goto fail;
 559         }
 560         spin_unlock_irq(&epdata->dev->lock);
 561         return -EIOCBQUEUED;
 562
 563 fail:
 564         spin_unlock_irq(&epdata->dev->lock);
 565         kfree(priv->to_free);
 566         kfree(priv);
 567         put_ep(epdata);
 568         return value;
 569 }
 570
 571 static ssize_t
 572 ep_read_iter(struct kiocb *iocb, struct iov_iter *to)
 573 {
 574         struct file *file = iocb->ki_filp;
 575         struct ep_data *epdata = file->private_data;
 576         size_t len = iov_iter_count(to);
 577         ssize_t value;
 578         char *buf;
 579
 580         if ((value = get_ready_ep(file->f_flags, epdata, false)) < 0)
 581                 return value;
 582
 583         /* halt any endpoint by doing a "wrong direction" i/o call */
 584         if (usb_endpoint_dir_in(&epdata->desc)) {
 585                 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
 586                     !is_sync_kiocb(iocb)) {
 587                         mutex_unlock(&epdata->lock);
 588                         return -EINVAL;
 589                 }
 590                 DBG (epdata->dev, "%s halt\n", epdata->name);
 591                 spin_lock_irq(&epdata->dev->lock);
 592                 if (likely(epdata->ep != NULL))
 593                         usb_ep_set_halt(epdata->ep);
 594                 spin_unlock_irq(&epdata->dev->lock);
 595                 mutex_unlock(&epdata->lock);
 596                 return -EBADMSG;
 597         }
 598
 599         buf = kmalloc(len, GFP_KERNEL);
 600         if (unlikely(!buf)) {
 601                 mutex_unlock(&epdata->lock);
 602                 return -ENOMEM;
 603         }
 604         if (is_sync_kiocb(iocb)) {
 605                 value = ep_io(epdata, buf, len);
 606                 if (value >= 0 && copy_to_iter(buf, value, to))
 607                         value = -EFAULT;
 608         } else {
 609                 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
 610                 value = -ENOMEM;
 611                 if (!priv)
 612                         goto fail;
 613                 priv->to_free = dup_iter(&priv->to, to, GFP_KERNEL);
 614                 if (!priv->to_free) {
 615                         kfree(priv);
 616                         goto fail;
 617                 }
 618                 value = ep_aio(iocb, priv, epdata, buf, len);
 619                 if (value == -EIOCBQUEUED)
 620                         buf = NULL;
 621         }
 622 fail:
 623         kfree(buf);
 624         mutex_unlock(&epdata->lock);
 625         return value;
 626 }
 627
 628 static ssize_t ep_config(struct ep_data *, const char *, size_t);
 629
 630 static ssize_t
 631 ep_write_iter(struct kiocb *iocb, struct iov_iter *from)
 632 {
 633         struct file *file = iocb->ki_filp;
 634         struct ep_data *epdata = file->private_data;
 635         size_t len = iov_iter_count(from);
 636         bool configured;
 637         ssize_t value;
 638         char *buf;
 639
 640         if ((value = get_ready_ep(file->f_flags, epdata, true)) < 0)
 641                 return value;
 642
 643         configured = epdata->state == STATE_EP_ENABLED;
 644
 645         /* halt any endpoint by doing a "wrong direction" i/o call */
 646         if (configured && !usb_endpoint_dir_in(&epdata->desc)) {
 647                 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
 648                     !is_sync_kiocb(iocb)) {
 649                         mutex_unlock(&epdata->lock);
 650                         return -EINVAL;
 651                 }
 652                 DBG (epdata->dev, "%s halt\n", epdata->name);
 653                 spin_lock_irq(&epdata->dev->lock);
 654                 if (likely(epdata->ep != NULL))
 655                         usb_ep_set_halt(epdata->ep);
 656                 spin_unlock_irq(&epdata->dev->lock);
 657                 mutex_unlock(&epdata->lock);
 658                 return -EBADMSG;
 659         }
 660
 661         buf = kmalloc(len, GFP_KERNEL);
 662         if (unlikely(!buf)) {
 663                 mutex_unlock(&epdata->lock);
 664                 return -ENOMEM;
 665         }
 666
 667         if (unlikely(copy_from_iter(buf, len, from) != len)) {
 668                 value = -EFAULT;
 669                 goto out;
 670         }
 671
 672         if (unlikely(!configured)) {
 673                 value = ep_config(epdata, buf, len);
 674         } else if (is_sync_kiocb(iocb)) {
 675                 value = ep_io(epdata, buf, len);
 676         } else {
 677                 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
 678                 value = -ENOMEM;
 679                 if (priv) {
 680                         value = ep_aio(iocb, priv, epdata, buf, len);
 681                         if (value == -EIOCBQUEUED)
 682                                 buf = NULL;
 683                 }
 684         }
 685 out:
 686         kfree(buf);
 687         mutex_unlock(&epdata->lock);
 688         return value;
 689 }
 690
 691 /*----------------------------------------------------------------------*/
 692
 693 /* used after endpoint configuration */
 694 static const struct file_operations ep_io_operations = {
 695         .owner =        THIS_MODULE,
 696
 697         .open =         ep_open,
 698         .release =      ep_release,
 699         .llseek =       no_llseek,
 700         .read =         new_sync_read,
 701         .write =        new_sync_write,
 702         .unlocked_ioctl = ep_ioctl,
 703         .read_iter =    ep_read_iter,
 704         .write_iter =   ep_write_iter,
 705 };
 706
 707 /* ENDPOINT INITIALIZATION
 708  *
 709  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 710  *     status = write (fd, descriptors, sizeof descriptors)
 711  *
 712  * That write establishes the endpoint configuration, configuring
 713  * the controller to process bulk, interrupt, or isochronous transfers
 714  * at the right maxpacket size, and so on.
 715  *
 716  * The descriptors are message type 1, identified by a host order u32
 717  * at the beginning of what's written.  Descriptor order is: full/low
 718  * speed descriptor, then optional high speed descriptor.
 719  */
 720 static ssize_t
 721 ep_config (struct ep_data *data, const char *buf, size_t len)
 722 {
 723         struct usb_ep           *ep;
 724         u32                     tag;
 725         int                     value, length = len;
 726
 727         if (data->state != STATE_EP_READY) {
 728                 value = -EL2HLT;
 729                 goto fail;
 730         }
 731
 732         value = len;
 733         if (len < USB_DT_ENDPOINT_SIZE + 4)
 734                 goto fail0;
 735
 736         /* we might need to change message format someday */
 737         memcpy(&tag, buf, 4);
 738         if (tag != 1) {
 739                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 740                 goto fail0;
 741         }
 742         buf += 4;
 743         len -= 4;
 744
 745         /* NOTE:  audio endpoint extensions not accepted here;
 746          * just don't include the extra bytes.
 747          */
 748
 749         /* full/low speed descriptor, then high speed */
 750         memcpy(&data->desc, buf, USB_DT_ENDPOINT_SIZE);
 751         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 752                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 753                 goto fail0;
 754         if (len != USB_DT_ENDPOINT_SIZE) {
 755                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 756                         goto fail0;
 757                 memcpy(&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 758                         USB_DT_ENDPOINT_SIZE);
 759                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 760                                 || data->hs_desc.bDescriptorType
 761                                         != USB_DT_ENDPOINT) {
 762                         DBG(data->dev, "config %s, bad hs length or type\n",
 763                                         data->name);
 764                         goto fail0;
 765                 }
 766         }
 767
 768         spin_lock_irq (&data->dev->lock);
 769         if (data->dev->state == STATE_DEV_UNBOUND) {
 770                 value = -ENOENT;
 771                 goto gone;
 772         } else if ((ep = data->ep) == NULL) {
 773                 value = -ENODEV;
 774                 goto gone;
 775         }
 776         switch (data->dev->gadget->speed) {
 777         case USB_SPEED_LOW:
 778         case USB_SPEED_FULL:
 779                 ep->desc = &data->desc;
 780                 break;
 781         case USB_SPEED_HIGH:
 782                 /* fails if caller didn't provide that descriptor... */
 783                 ep->desc = &data->hs_desc;
 784                 break;
 785         default:
 786                 DBG(data->dev, "unconnected, %s init abandoned\n",
 787                                 data->name);
 788                 value = -EINVAL;
 789                 goto gone;
 790         }
 791         value = usb_ep_enable(ep);
 792         if (value == 0) {
 793                 data->state = STATE_EP_ENABLED;
 794                 value = length;
 795         }
 796 gone:
 797         spin_unlock_irq (&data->dev->lock);
 798         if (value < 0) {
 799 fail:
 800                 data->desc.bDescriptorType = 0;
 801                 data->hs_desc.bDescriptorType = 0;
 802         }
 803         return value;
 804 fail0:
 805         value = -EINVAL;
 806         goto fail;
 807 }
 808
 809 static int
 810 ep_open (struct inode *inode, struct file *fd)
 811 {
 812         struct ep_data          *data = inode->i_private;
 813         int                     value = -EBUSY;
 814
 815         if (mutex_lock_interruptible(&data->lock) != 0)
 816                 return -EINTR;
 817         spin_lock_irq (&data->dev->lock);
 818         if (data->dev->state == STATE_DEV_UNBOUND)
 819                 value = -ENOENT;
 820         else if (data->state == STATE_EP_DISABLED) {
 821                 value = 0;
 822                 data->state = STATE_EP_READY;
 823                 get_ep (data);
 824                 fd->private_data = data;
 825                 VDEBUG (data->dev, "%s ready\n", data->name);
 826         } else
 827                 DBG (data->dev, "%s state %d\n",
 828                         data->name, data->state);
 829         spin_unlock_irq (&data->dev->lock);
 830         mutex_unlock(&data->lock);
 831         return value;
 832 }
 833
 834 /*----------------------------------------------------------------------*/
 835
 836 /* EP0 IMPLEMENTATION can be partly in userspace.
 837  *
 838  * Drivers that use this facility receive various events, including
 839  * control requests the kernel doesn't handle.  Drivers that don't
 840  * use this facility may be too simple-minded for real applications.
 841  */
 842
 843 static inline void ep0_readable (struct dev_data *dev)
 844 {
 845         wake_up (&dev->wait);
 846         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 847 }
 848
 849 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 850 {
 851         struct dev_data         *dev = ep->driver_data;
 852
 853         if (req->buf != dev->rbuf) {
 854                 kfree(req->buf);
 855                 req->buf = dev->rbuf;
 856         }
 857         req->complete = epio_complete;
 858         dev->setup_out_ready = 0;
 859 }
 860
 861 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 862 {
 863         struct dev_data         *dev = ep->driver_data;
 864         unsigned long           flags;
 865         int                     free = 1;
 866
 867         /* for control OUT, data must still get to userspace */
 868         spin_lock_irqsave(&dev->lock, flags);
 869         if (!dev->setup_in) {
 870                 dev->setup_out_error = (req->status != 0);
 871                 if (!dev->setup_out_error)
 872                         free = 0;
 873                 dev->setup_out_ready = 1;
 874                 ep0_readable (dev);
 875         }
 876
 877         /* clean up as appropriate */
 878         if (free && req->buf != &dev->rbuf)
 879                 clean_req (ep, req);
 880         req->complete = epio_complete;
 881         spin_unlock_irqrestore(&dev->lock, flags);
 882 }
 883
 884 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 885 {
 886         struct dev_data *dev = ep->driver_data;
 887
 888         if (dev->setup_out_ready) {
 889                 DBG (dev, "ep0 request busy!\n");
 890                 return -EBUSY;
 891         }
 892         if (len > sizeof (dev->rbuf))
 893                 req->buf = kmalloc(len, GFP_ATOMIC);
 894         if (req->buf == NULL) {
 895                 req->buf = dev->rbuf;
 896                 return -ENOMEM;
 897         }
 898         req->complete = ep0_complete;
 899         req->length = len;
 900         req->zero = 0;
 901         return 0;
 902 }
 903
 904 static ssize_t
 905 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 906 {
 907         struct dev_data                 *dev = fd->private_data;
 908         ssize_t                         retval;
 909         enum ep0_state                  state;
 910
 911         spin_lock_irq (&dev->lock);
 912         if (dev->state <= STATE_DEV_OPENED) {
 913                 retval = -EINVAL;
 914                 goto done;
 915         }
 916
 917         /* report fd mode change before acting on it */
 918         if (dev->setup_abort) {
 919                 dev->setup_abort = 0;
 920                 retval = -EIDRM;
 921                 goto done;
 922         }
 923
 924         /* control DATA stage */
 925         if ((state = dev->state) == STATE_DEV_SETUP) {
 926
 927                 if (dev->setup_in) {            /* stall IN */
 928                         VDEBUG(dev, "ep0in stall\n");
 929                         (void) usb_ep_set_halt (dev->gadget->ep0);
 930                         retval = -EL2HLT;
 931                         dev->state = STATE_DEV_CONNECTED;
 932
 933                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
 934                         struct usb_ep           *ep = dev->gadget->ep0;
 935                         struct usb_request      *req = dev->req;
 936
 937                         if ((retval = setup_req (ep, req, 0)) == 0)
 938                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
 939                         dev->state = STATE_DEV_CONNECTED;
 940
 941                         /* assume that was SET_CONFIGURATION */
 942                         if (dev->current_config) {
 943                                 unsigned power;
 944
 945                                 if (gadget_is_dualspeed(dev->gadget)
 946                                                 && (dev->gadget->speed
 947                                                         == USB_SPEED_HIGH))
 948                                         power = dev->hs_config->bMaxPower;
 949                                 else
 950                                         power = dev->config->bMaxPower;
 951                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
 952                         }
 953
 954                 } else {                        /* collect OUT data */
 955                         if ((fd->f_flags & O_NONBLOCK) != 0
 956                                         && !dev->setup_out_ready) {
 957                                 retval = -EAGAIN;
 958                                 goto done;
 959                         }
 960                         spin_unlock_irq (&dev->lock);
 961                         retval = wait_event_interruptible (dev->wait,
 962                                         dev->setup_out_ready != 0);
 963
 964                         /* FIXME state could change from under us */
 965                         spin_lock_irq (&dev->lock);
 966                         if (retval)
 967                                 goto done;
 968
 969                         if (dev->state != STATE_DEV_SETUP) {
 970                                 retval = -ECANCELED;
 971                                 goto done;
 972                         }
 973                         dev->state = STATE_DEV_CONNECTED;
 974
 975                         if (dev->setup_out_error)
 976                                 retval = -EIO;
 977                         else {
 978                                 len = min (len, (size_t)dev->req->actual);
 979 // FIXME don't call this with the spinlock held ...
 980                                 if (copy_to_user (buf, dev->req->buf, len))
 981                                         retval = -EFAULT;
 982                                 else
 983                                         retval = len;
 984                                 clean_req (dev->gadget->ep0, dev->req);
 985                                 /* NOTE userspace can't yet choose to stall */
 986                         }
 987                 }
 988                 goto done;
 989         }
 990
 991         /* else normal: return event data */
 992         if (len < sizeof dev->event [0]) {
 993                 retval = -EINVAL;
 994                 goto done;
 995         }
 996         len -= len % sizeof (struct usb_gadgetfs_event);
 997         dev->usermode_setup = 1;
 998
 999 scan:
1000         /* return queued events right away */
1001         if (dev->ev_next != 0) {
1002                 unsigned                i, n;
1003
1004                 n = len / sizeof (struct usb_gadgetfs_event);
1005                 if (dev->ev_next < n)
1006                         n = dev->ev_next;
1007
1008                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1009                 for (i = 0; i < n; i++) {
1010                         if (dev->event [i].type == GADGETFS_SETUP) {
1011                                 dev->state = STATE_DEV_SETUP;
1012                                 n = i + 1;
1013                                 break;
1014                         }
1015                 }
1016                 spin_unlock_irq (&dev->lock);
1017                 len = n * sizeof (struct usb_gadgetfs_event);
1018                 if (copy_to_user (buf, &dev->event, len))
1019                         retval = -EFAULT;
1020                 else
1021                         retval = len;
1022                 if (len > 0) {
1023                         /* NOTE this doesn't guard against broken drivers;
1024                          * concurrent ep0 readers may lose events.
1025                          */
1026                         spin_lock_irq (&dev->lock);
1027                         if (dev->ev_next > n) {
1028                                 memmove(&dev->event[0], &dev->event[n],
1029                                         sizeof (struct usb_gadgetfs_event)
1030                                                 * (dev->ev_next - n));
1031                         }
1032                         dev->ev_next -= n;
1033                         spin_unlock_irq (&dev->lock);
1034                 }
1035                 return retval;
1036         }
1037         if (fd->f_flags & O_NONBLOCK) {
1038                 retval = -EAGAIN;
1039                 goto done;
1040         }
1041
1042         switch (state) {
1043         default:
1044                 DBG (dev, "fail %s, state %d\n", __func__, state);
1045                 retval = -ESRCH;
1046                 break;
1047         case STATE_DEV_UNCONNECTED:
1048         case STATE_DEV_CONNECTED:
1049                 spin_unlock_irq (&dev->lock);
1050                 DBG (dev, "%s wait\n", __func__);
1051
1052                 /* wait for events */
1053                 retval = wait_event_interruptible (dev->wait,
1054                                 dev->ev_next != 0);
1055                 if (retval < 0)
1056                         return retval;
1057                 spin_lock_irq (&dev->lock);
1058                 goto scan;
1059         }
1060
1061 done:
1062         spin_unlock_irq (&dev->lock);
1063         return retval;
1064 }
1065
1066 static struct usb_gadgetfs_event *
1067 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1068 {
1069         struct usb_gadgetfs_event       *event;
1070         unsigned                        i;
1071
1072         switch (type) {
1073         /* these events purge the queue */
1074         case GADGETFS_DISCONNECT:
1075                 if (dev->state == STATE_DEV_SETUP)
1076                         dev->setup_abort = 1;
1077                 // FALL THROUGH
1078         case GADGETFS_CONNECT:
1079                 dev->ev_next = 0;
1080                 break;
1081         case GADGETFS_SETUP:            /* previous request timed out */
1082         case GADGETFS_SUSPEND:          /* same effect */
1083                 /* these events can't be repeated */
1084                 for (i = 0; i != dev->ev_next; i++) {
1085                         if (dev->event [i].type != type)
1086                                 continue;
1087                         DBG(dev, "discard old event[%d] %d\n", i, type);
1088                         dev->ev_next--;
1089                         if (i == dev->ev_next)
1090                                 break;
1091                         /* indices start at zero, for simplicity */
1092                         memmove (&dev->event [i], &dev->event [i + 1],
1093                                 sizeof (struct usb_gadgetfs_event)
1094                                         * (dev->ev_next - i));
1095                 }
1096                 break;
1097         default:
1098                 BUG ();
1099         }
1100         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1101         event = &dev->event [dev->ev_next++];
1102         BUG_ON (dev->ev_next > N_EVENT);
1103         memset (event, 0, sizeof *event);
1104         event->type = type;
1105         return event;
1106 }
1107
1108 static ssize_t
1109 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1110 {
1111         struct dev_data         *dev = fd->private_data;
1112         ssize_t                 retval = -ESRCH;
1113
1114         /* report fd mode change before acting on it */
1115         if (dev->setup_abort) {
1116                 dev->setup_abort = 0;
1117                 retval = -EIDRM;
1118
1119         /* data and/or status stage for control request */
1120         } else if (dev->state == STATE_DEV_SETUP) {
1121
1122                 /* IN DATA+STATUS caller makes len <= wLength */
1123                 if (dev->setup_in) {
1124                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1125                         if (retval == 0) {
1126                                 dev->state = STATE_DEV_CONNECTED;
1127                                 spin_unlock_irq (&dev->lock);
1128                                 if (copy_from_user (dev->req->buf, buf, len))
1129                                         retval = -EFAULT;
1130                                 else {
1131                                         if (len < dev->setup_wLength)
1132                                                 dev->req->zero = 1;
1133                                         retval = usb_ep_queue (
1134                                                 dev->gadget->ep0, dev->req,
1135                                                 GFP_KERNEL);
1136                                 }
1137                                 if (retval < 0) {
1138                                         spin_lock_irq (&dev->lock);
1139                                         clean_req (dev->gadget->ep0, dev->req);
1140                                         spin_unlock_irq (&dev->lock);
1141                                 } else
1142                                         retval = len;
1143
1144                                 return retval;
1145                         }
1146
1147                 /* can stall some OUT transfers */
1148                 } else if (dev->setup_can_stall) {
1149                         VDEBUG(dev, "ep0out stall\n");
1150                         (void) usb_ep_set_halt (dev->gadget->ep0);
1151                         retval = -EL2HLT;
1152                         dev->state = STATE_DEV_CONNECTED;
1153                 } else {
1154                         DBG(dev, "bogus ep0out stall!\n");
1155                 }
1156         } else
1157                 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1158
1159         return retval;
1160 }
1161
1162 static int
1163 ep0_fasync (int f, struct file *fd, int on)
1164 {
1165         struct dev_data         *dev = fd->private_data;
1166         // caller must F_SETOWN before signal delivery happens
1167         VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1168         return fasync_helper (f, fd, on, &dev->fasync);
1169 }
1170
1171 static struct usb_gadget_driver gadgetfs_driver;
1172
1173 static int
1174 dev_release (struct inode *inode, struct file *fd)
1175 {
1176         struct dev_data         *dev = fd->private_data;
1177
1178         /* closing ep0 === shutdown all */
1179
1180         usb_gadget_unregister_driver (&gadgetfs_driver);
1181
1182         /* at this point "good" hardware has disconnected the
1183          * device from USB; the host won't see it any more.
1184          * alternatively, all host requests will time out.
1185          */
1186
1187         kfree (dev->buf);
1188         dev->buf = NULL;
1189
1190         /* other endpoints were all decoupled from this device */
1191         spin_lock_irq(&dev->lock);
1192         dev->state = STATE_DEV_DISABLED;
1193         spin_unlock_irq(&dev->lock);
1194
1195         put_dev (dev);
1196         return 0;
1197 }
1198
1199 static unsigned int
1200 ep0_poll (struct file *fd, poll_table *wait)
1201 {
1202        struct dev_data         *dev = fd->private_data;
1203        int                     mask = 0;
1204
1205         if (dev->state <= STATE_DEV_OPENED)
1206                 return DEFAULT_POLLMASK;
1207
1208        poll_wait(fd, &dev->wait, wait);
1209
1210        spin_lock_irq (&dev->lock);
1211
1212        /* report fd mode change before acting on it */
1213        if (dev->setup_abort) {
1214                dev->setup_abort = 0;
1215                mask = POLLHUP;
1216                goto out;
1217        }
1218
1219        if (dev->state == STATE_DEV_SETUP) {
1220                if (dev->setup_in || dev->setup_can_stall)
1221                        mask = POLLOUT;
1222        } else {
1223                if (dev->ev_next != 0)
1224                        mask = POLLIN;
1225        }
1226 out:
1227        spin_unlock_irq(&dev->lock);
1228        return mask;
1229 }
1230
1231 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1232 {
1233         struct dev_data         *dev = fd->private_data;
1234         struct usb_gadget       *gadget = dev->gadget;
1235         long ret = -ENOTTY;
1236
1237         if (gadget->ops->ioctl)
1238                 ret = gadget->ops->ioctl (gadget, code, value);
1239
1240         return ret;
1241 }
1242
1243 /*----------------------------------------------------------------------*/
1244
1245 /* The in-kernel gadget driver handles most ep0 issues, in particular
1246  * enumerating the single configuration (as provided from user space).
1247  *
1248  * Unrecognized ep0 requests may be handled in user space.
1249  */
1250
1251 static void make_qualifier (struct dev_data *dev)
1252 {
1253         struct usb_qualifier_descriptor         qual;
1254         struct usb_device_descriptor            *desc;
1255
1256         qual.bLength = sizeof qual;
1257         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1258         qual.bcdUSB = cpu_to_le16 (0x0200);
1259
1260         desc = dev->dev;
1261         qual.bDeviceClass = desc->bDeviceClass;
1262         qual.bDeviceSubClass = desc->bDeviceSubClass;
1263         qual.bDeviceProtocol = desc->bDeviceProtocol;
1264
1265         /* assumes ep0 uses the same value for both speeds ... */
1266         qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1267
1268         qual.bNumConfigurations = 1;
1269         qual.bRESERVED = 0;
1270
1271         memcpy (dev->rbuf, &qual, sizeof qual);
1272 }
1273
1274 static int
1275 config_buf (struct dev_data *dev, u8 type, unsigned index)
1276 {
1277         int             len;
1278         int             hs = 0;
1279
1280         /* only one configuration */
1281         if (index > 0)
1282                 return -EINVAL;
1283
1284         if (gadget_is_dualspeed(dev->gadget)) {
1285                 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1286                 if (type == USB_DT_OTHER_SPEED_CONFIG)
1287                         hs = !hs;
1288         }
1289         if (hs) {
1290                 dev->req->buf = dev->hs_config;
1291                 len = le16_to_cpu(dev->hs_config->wTotalLength);
1292         } else {
1293                 dev->req->buf = dev->config;
1294                 len = le16_to_cpu(dev->config->wTotalLength);
1295         }
1296         ((u8 *)dev->req->buf) [1] = type;
1297         return len;
1298 }
1299
1300 static int
1301 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1302 {
1303         struct dev_data                 *dev = get_gadget_data (gadget);
1304         struct usb_request              *req = dev->req;
1305         int                             value = -EOPNOTSUPP;
1306         struct usb_gadgetfs_event       *event;
1307         u16                             w_value = le16_to_cpu(ctrl->wValue);
1308         u16                             w_length = le16_to_cpu(ctrl->wLength);
1309
1310         spin_lock (&dev->lock);
1311         dev->setup_abort = 0;
1312         if (dev->state == STATE_DEV_UNCONNECTED) {
1313                 if (gadget_is_dualspeed(gadget)
1314                                 && gadget->speed == USB_SPEED_HIGH
1315                                 && dev->hs_config == NULL) {
1316                         spin_unlock(&dev->lock);
1317                         ERROR (dev, "no high speed config??\n");
1318                         return -EINVAL;
1319                 }
1320
1321                 dev->state = STATE_DEV_CONNECTED;
1322
1323                 INFO (dev, "connected\n");
1324                 event = next_event (dev, GADGETFS_CONNECT);
1325                 event->u.speed = gadget->speed;
1326                 ep0_readable (dev);
1327
1328         /* host may have given up waiting for response.  we can miss control
1329          * requests handled lower down (device/endpoint status and features);
1330          * then ep0_{read,write} will report the wrong status. controller
1331          * driver will have aborted pending i/o.
1332          */
1333         } else if (dev->state == STATE_DEV_SETUP)
1334                 dev->setup_abort = 1;
1335
1336         req->buf = dev->rbuf;
1337         req->context = NULL;
1338         value = -EOPNOTSUPP;
1339         switch (ctrl->bRequest) {
1340
1341         case USB_REQ_GET_DESCRIPTOR:
1342                 if (ctrl->bRequestType != USB_DIR_IN)
1343                         goto unrecognized;
1344                 switch (w_value >> 8) {
1345
1346                 case USB_DT_DEVICE:
1347                         value = min (w_length, (u16) sizeof *dev->dev);
1348                         dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1349                         req->buf = dev->dev;
1350                         break;
1351                 case USB_DT_DEVICE_QUALIFIER:
1352                         if (!dev->hs_config)
1353                                 break;
1354                         value = min (w_length, (u16)
1355                                 sizeof (struct usb_qualifier_descriptor));
1356                         make_qualifier (dev);
1357                         break;
1358                 case USB_DT_OTHER_SPEED_CONFIG:
1359                         // FALLTHROUGH
1360                 case USB_DT_CONFIG:
1361                         value = config_buf (dev,
1362                                         w_value >> 8,
1363                                         w_value & 0xff);
1364                         if (value >= 0)
1365                                 value = min (w_length, (u16) value);
1366                         break;
1367                 case USB_DT_STRING:
1368                         goto unrecognized;
1369
1370                 default:                // all others are errors
1371                         break;
1372                 }
1373                 break;
1374
1375         /* currently one config, two speeds */
1376         case USB_REQ_SET_CONFIGURATION:
1377                 if (ctrl->bRequestType != 0)
1378                         goto unrecognized;
1379                 if (0 == (u8) w_value) {
1380                         value = 0;
1381                         dev->current_config = 0;
1382                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1383                         // user mode expected to disable endpoints
1384                 } else {
1385                         u8      config, power;
1386
1387                         if (gadget_is_dualspeed(gadget)
1388                                         && gadget->speed == USB_SPEED_HIGH) {
1389                                 config = dev->hs_config->bConfigurationValue;
1390                                 power = dev->hs_config->bMaxPower;
1391                         } else {
1392                                 config = dev->config->bConfigurationValue;
1393                                 power = dev->config->bMaxPower;
1394                         }
1395
1396                         if (config == (u8) w_value) {
1397                                 value = 0;
1398                                 dev->current_config = config;
1399                                 usb_gadget_vbus_draw(gadget, 2 * power);
1400                         }
1401                 }
1402
1403                 /* report SET_CONFIGURATION like any other control request,
1404                  * except that usermode may not stall this.  the next
1405                  * request mustn't be allowed start until this finishes:
1406                  * endpoints and threads set up, etc.
1407                  *
1408                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1409                  * has bad/racey automagic that prevents synchronizing here.
1410                  * even kernel mode drivers often miss them.
1411                  */
1412                 if (value == 0) {
1413                         INFO (dev, "configuration #%d\n", dev->current_config);
1414                         usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
1415                         if (dev->usermode_setup) {
1416                                 dev->setup_can_stall = 0;
1417                                 goto delegate;
1418                         }
1419                 }
1420                 break;
1421
1422 #ifndef CONFIG_USB_PXA25X
1423         /* PXA automagically handles this request too */
1424         case USB_REQ_GET_CONFIGURATION:
1425                 if (ctrl->bRequestType != 0x80)
1426                         goto unrecognized;
1427                 *(u8 *)req->buf = dev->current_config;
1428                 value = min (w_length, (u16) 1);
1429                 break;
1430 #endif
1431
1432         default:
1433 unrecognized:
1434                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1435                         dev->usermode_setup ? "delegate" : "fail",
1436                         ctrl->bRequestType, ctrl->bRequest,
1437                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1438
1439                 /* if there's an ep0 reader, don't stall */
1440                 if (dev->usermode_setup) {
1441                         dev->setup_can_stall = 1;
1442 delegate:
1443                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1444                                                 ? 1 : 0;
1445                         dev->setup_wLength = w_length;
1446                         dev->setup_out_ready = 0;
1447                         dev->setup_out_error = 0;
1448                         value = 0;
1449
1450                         /* read DATA stage for OUT right away */
1451                         if (unlikely (!dev->setup_in && w_length)) {
1452                                 value = setup_req (gadget->ep0, dev->req,
1453                                                         w_length);
1454                                 if (value < 0)
1455                                         break;
1456                                 value = usb_ep_queue (gadget->ep0, dev->req,
1457                                                         GFP_ATOMIC);
1458                                 if (value < 0) {
1459                                         clean_req (gadget->ep0, dev->req);
1460                                         break;
1461                                 }
1462
1463                                 /* we can't currently stall these */
1464                                 dev->setup_can_stall = 0;
1465                         }
1466
1467                         /* state changes when reader collects event */
1468                         event = next_event (dev, GADGETFS_SETUP);
1469                         event->u.setup = *ctrl;
1470                         ep0_readable (dev);
1471                         spin_unlock (&dev->lock);
1472                         return 0;
1473                 }
1474         }
1475
1476         /* proceed with data transfer and status phases? */
1477         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1478                 req->length = value;
1479                 req->zero = value < w_length;
1480                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1481                 if (value < 0) {
1482                         DBG (dev, "ep_queue --> %d\n", value);
1483                         req->status = 0;
1484                 }
1485         }
1486
1487         /* device stalls when value < 0 */
1488         spin_unlock (&dev->lock);
1489         return value;
1490 }
1491
1492 static void destroy_ep_files (struct dev_data *dev)
1493 {
1494         DBG (dev, "%s %d\n", __func__, dev->state);
1495
1496         /* dev->state must prevent interference */
1497         spin_lock_irq (&dev->lock);
1498         while (!list_empty(&dev->epfiles)) {
1499                 struct ep_data  *ep;
1500                 struct inode    *parent;
1501                 struct dentry   *dentry;
1502
1503                 /* break link to FS */
1504                 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1505                 list_del_init (&ep->epfiles);
1506                 dentry = ep->dentry;
1507                 ep->dentry = NULL;
1508                 parent = dentry->d_parent->d_inode;
1509
1510                 /* break link to controller */
1511                 if (ep->state == STATE_EP_ENABLED)
1512                         (void) usb_ep_disable (ep->ep);
1513                 ep->state = STATE_EP_UNBOUND;
1514                 usb_ep_free_request (ep->ep, ep->req);
1515                 ep->ep = NULL;
1516                 wake_up (&ep->wait);
1517                 put_ep (ep);
1518
1519                 spin_unlock_irq (&dev->lock);
1520
1521                 /* break link to dcache */
1522                 mutex_lock (&parent->i_mutex);
1523                 d_delete (dentry);
1524                 dput (dentry);
1525                 mutex_unlock (&parent->i_mutex);
1526
1527                 spin_lock_irq (&dev->lock);
1528         }
1529         spin_unlock_irq (&dev->lock);
1530 }
1531
1532
1533 static struct dentry *
1534 gadgetfs_create_file (struct super_block *sb, char const *name,
1535                 void *data, const struct file_operations *fops);
1536
1537 static int activate_ep_files (struct dev_data *dev)
1538 {
1539         struct usb_ep   *ep;
1540         struct ep_data  *data;
1541
1542         gadget_for_each_ep (ep, dev->gadget) {
1543
1544                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1545                 if (!data)
1546                         goto enomem0;
1547                 data->state = STATE_EP_DISABLED;
1548                 mutex_init(&data->lock);
1549                 init_waitqueue_head (&data->wait);
1550
1551                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1552                 atomic_set (&data->count, 1);
1553                 data->dev = dev;
1554                 get_dev (dev);
1555
1556                 data->ep = ep;
1557                 ep->driver_data = data;
1558
1559                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1560                 if (!data->req)
1561                         goto enomem1;
1562
1563                 data->dentry = gadgetfs_create_file (dev->sb, data->name,
1564                                 data, &ep_io_operations);
1565                 if (!data->dentry)
1566                         goto enomem2;
1567                 list_add_tail (&data->epfiles, &dev->epfiles);
1568         }
1569         return 0;
1570
1571 enomem2:
1572         usb_ep_free_request (ep, data->req);
1573 enomem1:
1574         put_dev (dev);
1575         kfree (data);
1576 enomem0:
1577         DBG (dev, "%s enomem\n", __func__);
1578         destroy_ep_files (dev);
1579         return -ENOMEM;
1580 }
1581
1582 static void
1583 gadgetfs_unbind (struct usb_gadget *gadget)
1584 {
1585         struct dev_data         *dev = get_gadget_data (gadget);
1586
1587         DBG (dev, "%s\n", __func__);
1588
1589         spin_lock_irq (&dev->lock);
1590         dev->state = STATE_DEV_UNBOUND;
1591         spin_unlock_irq (&dev->lock);
1592
1593         destroy_ep_files (dev);
1594         gadget->ep0->driver_data = NULL;
1595         set_gadget_data (gadget, NULL);
1596
1597         /* we've already been disconnected ... no i/o is active */
1598         if (dev->req)
1599                 usb_ep_free_request (gadget->ep0, dev->req);
1600         DBG (dev, "%s done\n", __func__);
1601         put_dev (dev);
1602 }
1603
1604 static struct dev_data          *the_device;
1605
1606 static int gadgetfs_bind(struct usb_gadget *gadget,
1607                 struct usb_gadget_driver *driver)
1608 {
1609         struct dev_data         *dev = the_device;
1610
1611         if (!dev)
1612                 return -ESRCH;
1613         if (0 != strcmp (CHIP, gadget->name)) {
1614                 pr_err("%s expected %s controller not %s\n",
1615                         shortname, CHIP, gadget->name);
1616                 return -ENODEV;
1617         }
1618
1619         set_gadget_data (gadget, dev);
1620         dev->gadget = gadget;
1621         gadget->ep0->driver_data = dev;
1622
1623         /* preallocate control response and buffer */
1624         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1625         if (!dev->req)
1626                 goto enomem;
1627         dev->req->context = NULL;
1628         dev->req->complete = epio_complete;
1629
1630         if (activate_ep_files (dev) < 0)
1631                 goto enomem;
1632
1633         INFO (dev, "bound to %s driver\n", gadget->name);
1634         spin_lock_irq(&dev->lock);
1635         dev->state = STATE_DEV_UNCONNECTED;
1636         spin_unlock_irq(&dev->lock);
1637         get_dev (dev);
1638         return 0;
1639
1640 enomem:
1641         gadgetfs_unbind (gadget);
1642         return -ENOMEM;
1643 }
1644
1645 static void
1646 gadgetfs_disconnect (struct usb_gadget *gadget)
1647 {
1648         struct dev_data         *dev = get_gadget_data (gadget);
1649         unsigned long           flags;
1650
1651         spin_lock_irqsave (&dev->lock, flags);
1652         if (dev->state == STATE_DEV_UNCONNECTED)
1653                 goto exit;
1654         dev->state = STATE_DEV_UNCONNECTED;
1655
1656         INFO (dev, "disconnected\n");
1657         next_event (dev, GADGETFS_DISCONNECT);
1658         ep0_readable (dev);
1659 exit:
1660         spin_unlock_irqrestore (&dev->lock, flags);
1661 }
1662
1663 static void
1664 gadgetfs_suspend (struct usb_gadget *gadget)
1665 {
1666         struct dev_data         *dev = get_gadget_data (gadget);
1667
1668         INFO (dev, "suspended from state %d\n", dev->state);
1669         spin_lock (&dev->lock);
1670         switch (dev->state) {
1671         case STATE_DEV_SETUP:           // VERY odd... host died??
1672         case STATE_DEV_CONNECTED:
1673         case STATE_DEV_UNCONNECTED:
1674                 next_event (dev, GADGETFS_SUSPEND);
1675                 ep0_readable (dev);
1676                 /* FALLTHROUGH */
1677         default:
1678                 break;
1679         }
1680         spin_unlock (&dev->lock);
1681 }
1682
1683 static struct usb_gadget_driver gadgetfs_driver = {
1684         .function       = (char *) driver_desc,
1685         .bind           = gadgetfs_bind,
1686         .unbind         = gadgetfs_unbind,
1687         .setup          = gadgetfs_setup,
1688         .reset          = gadgetfs_disconnect,
1689         .disconnect     = gadgetfs_disconnect,
1690         .suspend        = gadgetfs_suspend,
1691
1692         .driver = {
1693                 .name           = (char *) shortname,
1694         },
1695 };
1696
1697 /*----------------------------------------------------------------------*/
1698
1699 static void gadgetfs_nop(struct usb_gadget *arg) { }
1700
1701 static int gadgetfs_probe(struct usb_gadget *gadget,
1702                 struct usb_gadget_driver *driver)
1703 {
1704         CHIP = gadget->name;
1705         return -EISNAM;
1706 }
1707
1708 static struct usb_gadget_driver probe_driver = {
1709         .max_speed      = USB_SPEED_HIGH,
1710         .bind           = gadgetfs_probe,
1711         .unbind         = gadgetfs_nop,
1712         .setup          = (void *)gadgetfs_nop,
1713         .disconnect     = gadgetfs_nop,
1714         .driver = {
1715                 .name           = "nop",
1716         },
1717 };
1718
1719
1720 /* DEVICE INITIALIZATION
1721  *
1722  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1723  *     status = write (fd, descriptors, sizeof descriptors)
1724  *
1725  * That write establishes the device configuration, so the kernel can
1726  * bind to the controller ... guaranteeing it can handle enumeration
1727  * at all necessary speeds.  Descriptor order is:
1728  *
1729  * . message tag (u32, host order) ... for now, must be zero; it
1730  *      would change to support features like multi-config devices
1731  * . full/low speed config ... all wTotalLength bytes (with interface,
1732  *      class, altsetting, endpoint, and other descriptors)
1733  * . high speed config ... all descriptors, for high speed operation;
1734  *      this one's optional except for high-speed hardware
1735  * . device descriptor
1736  *
1737  * Endpoints are not yet enabled. Drivers must wait until device
1738  * configuration and interface altsetting changes create
1739  * the need to configure (or unconfigure) them.
1740  *
1741  * After initialization, the device stays active for as long as that
1742  * $CHIP file is open.  Events must then be read from that descriptor,
1743  * such as configuration notifications.
1744  */
1745
1746 static int is_valid_config (struct usb_config_descriptor *config)
1747 {
1748         return config->bDescriptorType == USB_DT_CONFIG
1749                 && config->bLength == USB_DT_CONFIG_SIZE
1750                 && config->bConfigurationValue != 0
1751                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1752                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1753         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1754         /* FIXME check lengths: walk to end */
1755 }
1756
1757 static ssize_t
1758 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1759 {
1760         struct dev_data         *dev = fd->private_data;
1761         ssize_t                 value = len, length = len;
1762         unsigned                total;
1763         u32                     tag;
1764         char                    *kbuf;
1765
1766         spin_lock_irq(&dev->lock);
1767         if (dev->state > STATE_DEV_OPENED) {
1768                 value = ep0_write(fd, buf, len, ptr);
1769                 spin_unlock_irq(&dev->lock);
1770                 return value;
1771         }
1772         spin_unlock_irq(&dev->lock);
1773
1774         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1775                 return -EINVAL;
1776
1777         /* we might need to change message format someday */
1778         if (copy_from_user (&tag, buf, 4))
1779                 return -EFAULT;
1780         if (tag != 0)
1781                 return -EINVAL;
1782         buf += 4;
1783         length -= 4;
1784
1785         kbuf = memdup_user(buf, length);
1786         if (IS_ERR(kbuf))
1787                 return PTR_ERR(kbuf);
1788
1789         spin_lock_irq (&dev->lock);
1790         value = -EINVAL;
1791         if (dev->buf)
1792                 goto fail;
1793         dev->buf = kbuf;
1794
1795         /* full or low speed config */
1796         dev->config = (void *) kbuf;
1797         total = le16_to_cpu(dev->config->wTotalLength);
1798         if (!is_valid_config (dev->config) || total >= length)
1799                 goto fail;
1800         kbuf += total;
1801         length -= total;
1802
1803         /* optional high speed config */
1804         if (kbuf [1] == USB_DT_CONFIG) {
1805                 dev->hs_config = (void *) kbuf;
1806                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1807                 if (!is_valid_config (dev->hs_config) || total >= length)
1808                         goto fail;
1809                 kbuf += total;
1810                 length -= total;
1811         }
1812
1813         /* could support multiple configs, using another encoding! */
1814
1815         /* device descriptor (tweaked for paranoia) */
1816         if (length != USB_DT_DEVICE_SIZE)
1817                 goto fail;
1818         dev->dev = (void *)kbuf;
1819         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1820                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1821                         || dev->dev->bNumConfigurations != 1)
1822                 goto fail;
1823         dev->dev->bNumConfigurations = 1;
1824         dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1825
1826         /* triggers gadgetfs_bind(); then we can enumerate. */
1827         spin_unlock_irq (&dev->lock);
1828         if (dev->hs_config)
1829                 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1830         else
1831                 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1832
1833         value = usb_gadget_probe_driver(&gadgetfs_driver);
1834         if (value != 0) {
1835                 kfree (dev->buf);
1836                 dev->buf = NULL;
1837         } else {
1838                 /* at this point "good" hardware has for the first time
1839                  * let the USB the host see us.  alternatively, if users
1840                  * unplug/replug that will clear all the error state.
1841                  *
1842                  * note:  everything running before here was guaranteed
1843                  * to choke driver model style diagnostics.  from here
1844                  * on, they can work ... except in cleanup paths that
1845                  * kick in after the ep0 descriptor is closed.
1846                  */
1847                 value = len;
1848         }
1849         return value;
1850
1851 fail:
1852         spin_unlock_irq (&dev->lock);
1853         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1854         kfree (dev->buf);
1855         dev->buf = NULL;
1856         return value;
1857 }
1858
1859 static int
1860 dev_open (struct inode *inode, struct file *fd)
1861 {
1862         struct dev_data         *dev = inode->i_private;
1863         int                     value = -EBUSY;
1864
1865         spin_lock_irq(&dev->lock);
1866         if (dev->state == STATE_DEV_DISABLED) {
1867                 dev->ev_next = 0;
1868                 dev->state = STATE_DEV_OPENED;
1869                 fd->private_data = dev;
1870                 get_dev (dev);
1871                 value = 0;
1872         }
1873         spin_unlock_irq(&dev->lock);
1874         return value;
1875 }
1876
1877 static const struct file_operations ep0_operations = {
1878         .llseek =       no_llseek,
1879
1880         .open =         dev_open,
1881         .read =         ep0_read,
1882         .write =        dev_config,
1883         .fasync =       ep0_fasync,
1884         .poll =         ep0_poll,
1885         .unlocked_ioctl = dev_ioctl,
1886         .release =      dev_release,
1887 };
1888
1889 /*----------------------------------------------------------------------*/
1890
1891 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1892  *
1893  * Mounting the filesystem creates a controller file, used first for
1894  * device configuration then later for event monitoring.
1895  */
1896
1897
1898 /* FIXME PAM etc could set this security policy without mount options
1899  * if epfiles inherited ownership and permissons from ep0 ...
1900  */
1901
1902 static unsigned default_uid;
1903 static unsigned default_gid;
1904 static unsigned default_perm = S_IRUSR | S_IWUSR;
1905
1906 module_param (default_uid, uint, 0644);
1907 module_param (default_gid, uint, 0644);
1908 module_param (default_perm, uint, 0644);
1909
1910
1911 static struct inode *
1912 gadgetfs_make_inode (struct super_block *sb,
1913                 void *data, const struct file_operations *fops,
1914                 int mode)
1915 {
1916         struct inode *inode = new_inode (sb);
1917
1918         if (inode) {
1919                 inode->i_ino = get_next_ino();
1920                 inode->i_mode = mode;
1921                 inode->i_uid = make_kuid(&init_user_ns, default_uid);
1922                 inode->i_gid = make_kgid(&init_user_ns, default_gid);
1923                 inode->i_atime = inode->i_mtime = inode->i_ctime
1924                                 = CURRENT_TIME;
1925                 inode->i_private = data;
1926                 inode->i_fop = fops;
1927         }
1928         return inode;
1929 }
1930
1931 /* creates in fs root directory, so non-renamable and non-linkable.
1932  * so inode and dentry are paired, until device reconfig.
1933  */
1934 static struct dentry *
1935 gadgetfs_create_file (struct super_block *sb, char const *name,
1936                 void *data, const struct file_operations *fops)
1937 {
1938         struct dentry   *dentry;
1939         struct inode    *inode;
1940
1941         dentry = d_alloc_name(sb->s_root, name);
1942         if (!dentry)
1943                 return NULL;
1944
1945         inode = gadgetfs_make_inode (sb, data, fops,
1946                         S_IFREG | (default_perm & S_IRWXUGO));
1947         if (!inode) {
1948                 dput(dentry);
1949                 return NULL;
1950         }
1951         d_add (dentry, inode);
1952         return dentry;
1953 }
1954
1955 static const struct super_operations gadget_fs_operations = {
1956         .statfs =       simple_statfs,
1957         .drop_inode =   generic_delete_inode,
1958 };
1959
1960 static int
1961 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
1962 {
1963         struct inode    *inode;
1964         struct dev_data *dev;
1965
1966         if (the_device)
1967                 return -ESRCH;
1968
1969         /* fake probe to determine $CHIP */
1970         CHIP = NULL;
1971         usb_gadget_probe_driver(&probe_driver);
1972         if (!CHIP)
1973                 return -ENODEV;
1974
1975         /* superblock */
1976         sb->s_blocksize = PAGE_CACHE_SIZE;
1977         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1978         sb->s_magic = GADGETFS_MAGIC;
1979         sb->s_op = &gadget_fs_operations;
1980         sb->s_time_gran = 1;
1981
1982         /* root inode */
1983         inode = gadgetfs_make_inode (sb,
1984                         NULL, &simple_dir_operations,
1985                         S_IFDIR | S_IRUGO | S_IXUGO);
1986         if (!inode)
1987                 goto Enomem;
1988         inode->i_op = &simple_dir_inode_operations;
1989         if (!(sb->s_root = d_make_root (inode)))
1990                 goto Enomem;
1991
1992         /* the ep0 file is named after the controller we expect;
1993          * user mode code can use it for sanity checks, like we do.
1994          */
1995         dev = dev_new ();
1996         if (!dev)
1997                 goto Enomem;
1998
1999         dev->sb = sb;
2000         dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &ep0_operations);
2001         if (!dev->dentry) {
2002                 put_dev(dev);
2003                 goto Enomem;
2004         }
2005
2006         /* other endpoint files are available after hardware setup,
2007          * from binding to a controller.
2008          */
2009         the_device = dev;
2010         return 0;
2011
2012 Enomem:
2013         return -ENOMEM;
2014 }
2015
2016 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2017 static struct dentry *
2018 gadgetfs_mount (struct file_system_type *t, int flags,
2019                 const char *path, void *opts)
2020 {
2021         return mount_single (t, flags, opts, gadgetfs_fill_super);
2022 }
2023
2024 static void
2025 gadgetfs_kill_sb (struct super_block *sb)
2026 {
2027         kill_litter_super (sb);
2028         if (the_device) {
2029                 put_dev (the_device);
2030                 the_device = NULL;
2031         }
2032 }
2033
2034 /*----------------------------------------------------------------------*/
2035
2036 static struct file_system_type gadgetfs_type = {
2037         .owner          = THIS_MODULE,
2038         .name           = shortname,
2039         .mount          = gadgetfs_mount,
2040         .kill_sb        = gadgetfs_kill_sb,
2041 };
2042 MODULE_ALIAS_FS("gadgetfs");
2043
2044 /*----------------------------------------------------------------------*/
2045
2046 static int __init init (void)
2047 {
2048         int status;
2049
2050         status = register_filesystem (&gadgetfs_type);
2051         if (status == 0)
2052                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2053                         shortname, driver_desc);
2054         return status;
2055 }
2056 module_init (init);
2057
2058 static void __exit cleanup (void)
2059 {
2060         pr_debug ("unregister %s\n", shortname);
2061         unregister_filesystem (&gadgetfs_type);
2062 }
2063 module_exit (cleanup);
2064