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 <linux/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 #include <linux/uio.h>
  30 #include <linux/refcount.h>
  31
  32 #include <linux/device.h>
  33 #include <linux/moduleparam.h>
  34
  35 #include <linux/usb/gadgetfs.h>
  36 #include <linux/usb/gadget.h>
  37
  38
  39 /*
  40  * The gadgetfs API maps each endpoint to a file descriptor so that you
  41  * can use standard synchronous read/write calls for I/O.  There's some
  42  * O_NONBLOCK and O_ASYNC/FASYNC style i/o support.  Example usermode
  43  * drivers show how this works in practice.  You can also use AIO to
  44  * eliminate I/O gaps between requests, to help when streaming data.
  45  *
  46  * Key parts that must be USB-specific are protocols defining how the
  47  * read/write operations relate to the hardware state machines.  There
  48  * are two types of files.  One type is for the device, implementing ep0.
  49  * The other type is for each IN or OUT endpoint.  In both cases, the
  50  * user mode driver must configure the hardware before using it.
  51  *
  52  * - First, dev_config() is called when /dev/gadget/$CHIP is configured
  53  *   (by writing configuration and device descriptors).  Afterwards it
  54  *   may serve as a source of device events, used to handle all control
  55  *   requests other than basic enumeration.
  56  *
  57  * - Then, after a SET_CONFIGURATION control request, ep_config() is
  58  *   called when each /dev/gadget/ep* file is configured (by writing
  59  *   endpoint descriptors).  Afterwards these files are used to write()
  60  *   IN data or to read() OUT data.  To halt the endpoint, a "wrong
  61  *   direction" request is issued (like reading an IN endpoint).
  62  *
  63  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
  64  * not possible on all hardware.  For example, precise fault handling with
  65  * respect to data left in endpoint fifos after aborted operations; or
  66  * selective clearing of endpoint halts, to implement SET_INTERFACE.
  67  */
  68
  69 #define DRIVER_DESC     "USB Gadget filesystem"
  70 #define DRIVER_VERSION  "24 Aug 2004"
  71
  72 static const char driver_desc [] = DRIVER_DESC;
  73 static const char shortname [] = "gadgetfs";
  74
  75 MODULE_DESCRIPTION (DRIVER_DESC);
  76 MODULE_AUTHOR ("David Brownell");
  77 MODULE_LICENSE ("GPL");
  78
  79 static int ep_open(struct inode *, struct file *);
  80
  81
  82 /*----------------------------------------------------------------------*/
  83
  84 #define GADGETFS_MAGIC          0xaee71ee7
  85
  86 /* /dev/gadget/$CHIP represents ep0 and the whole device */
  87 enum ep0_state {
  88         /* DISABLED is the initial state. */
  89         STATE_DEV_DISABLED = 0,
  90
  91         /* Only one open() of /dev/gadget/$CHIP; only one file tracks
  92          * ep0/device i/o modes and binding to the controller.  Driver
  93          * must always write descriptors to initialize the device, then
  94          * the device becomes UNCONNECTED until enumeration.
  95          */
  96         STATE_DEV_OPENED,
  97
  98         /* From then on, ep0 fd is in either of two basic modes:
  99          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
 100          * - SETUP: read/write will transfer control data and succeed;
 101          *   or if "wrong direction", performs protocol stall
 102          */
 103         STATE_DEV_UNCONNECTED,
 104         STATE_DEV_CONNECTED,
 105         STATE_DEV_SETUP,
 106
 107         /* UNBOUND means the driver closed ep0, so the device won't be
 108          * accessible again (DEV_DISABLED) until all fds are closed.
 109          */
 110         STATE_DEV_UNBOUND,
 111 };
 112
 113 /* enough for the whole queue: most events invalidate others */
 114 #define N_EVENT                 5
 115
 116 struct dev_data {
 117         spinlock_t                      lock;
 118         refcount_t                      count;
 119         enum ep0_state                  state;          /* P: lock */
 120         struct usb_gadgetfs_event       event [N_EVENT];
 121         unsigned                        ev_next;
 122         struct fasync_struct            *fasync;
 123         u8                              current_config;
 124
 125         /* drivers reading ep0 MUST handle control requests (SETUP)
 126          * reported that way; else the host will time out.
 127          */
 128         unsigned                        usermode_setup : 1,
 129                                         setup_in : 1,
 130                                         setup_can_stall : 1,
 131                                         setup_out_ready : 1,
 132                                         setup_out_error : 1,
 133                                         setup_abort : 1,
 134                                         gadget_registered : 1;
 135         unsigned                        setup_wLength;
 136
 137         /* the rest is basically write-once */
 138         struct usb_config_descriptor    *config, *hs_config;
 139         struct usb_device_descriptor    *dev;
 140         struct usb_request              *req;
 141         struct usb_gadget               *gadget;
 142         struct list_head                epfiles;
 143         void                            *buf;
 144         wait_queue_head_t               wait;
 145         struct super_block              *sb;
 146         struct dentry                   *dentry;
 147
 148         /* except this scratch i/o buffer for ep0 */
 149         u8                              rbuf [256];
 150 };
 151
 152 static inline void get_dev (struct dev_data *data)
 153 {
 154         refcount_inc (&data->count);
 155 }
 156
 157 static void put_dev (struct dev_data *data)
 158 {
 159         if (likely (!refcount_dec_and_test (&data->count)))
 160                 return;
 161         /* needs no more cleanup */
 162         BUG_ON (waitqueue_active (&data->wait));
 163         kfree (data);
 164 }
 165
 166 static struct dev_data *dev_new (void)
 167 {
 168         struct dev_data         *dev;
 169
 170         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 171         if (!dev)
 172                 return NULL;
 173         dev->state = STATE_DEV_DISABLED;
 174         refcount_set (&dev->count, 1);
 175         spin_lock_init (&dev->lock);
 176         INIT_LIST_HEAD (&dev->epfiles);
 177         init_waitqueue_head (&dev->wait);
 178         return dev;
 179 }
 180
 181 /*----------------------------------------------------------------------*/
 182
 183 /* other /dev/gadget/$ENDPOINT files represent endpoints */
 184 enum ep_state {
 185         STATE_EP_DISABLED = 0,
 186         STATE_EP_READY,
 187         STATE_EP_ENABLED,
 188         STATE_EP_UNBOUND,
 189 };
 190
 191 struct ep_data {
 192         struct mutex                    lock;
 193         enum ep_state                   state;
 194         refcount_t                      count;
 195         struct dev_data                 *dev;
 196         /* must hold dev->lock before accessing ep or req */
 197         struct usb_ep                   *ep;
 198         struct usb_request              *req;
 199         ssize_t                         status;
 200         char                            name [16];
 201         struct usb_endpoint_descriptor  desc, hs_desc;
 202         struct list_head                epfiles;
 203         wait_queue_head_t               wait;
 204         struct dentry                   *dentry;
 205 };
 206
 207 static inline void get_ep (struct ep_data *data)
 208 {
 209         refcount_inc (&data->count);
 210 }
 211
 212 static void put_ep (struct ep_data *data)
 213 {
 214         if (likely (!refcount_dec_and_test (&data->count)))
 215                 return;
 216         put_dev (data->dev);
 217         /* needs no more cleanup */
 218         BUG_ON (!list_empty (&data->epfiles));
 219         BUG_ON (waitqueue_active (&data->wait));
 220         kfree (data);
 221 }
 222
 223 /*----------------------------------------------------------------------*/
 224
 225 /* most "how to use the hardware" policy choices are in userspace:
 226  * mapping endpoint roles (which the driver needs) to the capabilities
 227  * which the usb controller has.  most of those capabilities are exposed
 228  * implicitly, starting with the driver name and then endpoint names.
 229  */
 230
 231 static const char *CHIP;
 232
 233 /*----------------------------------------------------------------------*/
 234
 235 /* NOTE:  don't use dev_printk calls before binding to the gadget
 236  * at the end of ep0 configuration, or after unbind.
 237  */
 238
 239 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
 240 #define xprintk(d,level,fmt,args...) \
 241         printk(level "%s: " fmt , shortname , ## args)
 242
 243 #ifdef DEBUG
 244 #define DBG(dev,fmt,args...) \
 245         xprintk(dev , KERN_DEBUG , fmt , ## args)
 246 #else
 247 #define DBG(dev,fmt,args...) \
 248         do { } while (0)
 249 #endif /* DEBUG */
 250
 251 #ifdef VERBOSE_DEBUG
 252 #define VDEBUG  DBG
 253 #else
 254 #define VDEBUG(dev,fmt,args...) \
 255         do { } while (0)
 256 #endif /* DEBUG */
 257
 258 #define ERROR(dev,fmt,args...) \
 259         xprintk(dev , KERN_ERR , fmt , ## args)
 260 #define INFO(dev,fmt,args...) \
 261         xprintk(dev , KERN_INFO , fmt , ## args)
 262
 263
 264 /*----------------------------------------------------------------------*/
 265
 266 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 267  *
 268  * After opening, configure non-control endpoints.  Then use normal
 269  * stream read() and write() requests; and maybe ioctl() to get more
 270  * precise FIFO status when recovering from cancellation.
 271  */
 272
 273 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 274 {
 275         struct ep_data  *epdata = ep->driver_data;
 276
 277         if (!req->context)
 278                 return;
 279         if (req->status)
 280                 epdata->status = req->status;
 281         else
 282                 epdata->status = req->actual;
 283         complete ((struct completion *)req->context);
 284 }
 285
 286 /* tasklock endpoint, returning when it's connected.
 287  * still need dev->lock to use epdata->ep.
 288  */
 289 static int
 290 get_ready_ep (unsigned f_flags, struct ep_data *epdata, bool is_write)
 291 {
 292         int     val;
 293
 294         if (f_flags & O_NONBLOCK) {
 295                 if (!mutex_trylock(&epdata->lock))
 296                         goto nonblock;
 297                 if (epdata->state != STATE_EP_ENABLED &&
 298                     (!is_write || epdata->state != STATE_EP_READY)) {
 299                         mutex_unlock(&epdata->lock);
 300 nonblock:
 301                         val = -EAGAIN;
 302                 } else
 303                         val = 0;
 304                 return val;
 305         }
 306
 307         val = mutex_lock_interruptible(&epdata->lock);
 308         if (val < 0)
 309                 return val;
 310
 311         switch (epdata->state) {
 312         case STATE_EP_ENABLED:
 313                 return 0;
 314         case STATE_EP_READY:                    /* not configured yet */
 315                 if (is_write)
 316                         return 0;
 317                 // FALLTHRU
 318         case STATE_EP_UNBOUND:                  /* clean disconnect */
 319                 break;
 320         // case STATE_EP_DISABLED:              /* "can't happen" */
 321         default:                                /* error! */
 322                 pr_debug ("%s: ep %p not available, state %d\n",
 323                                 shortname, epdata, epdata->state);
 324         }
 325         mutex_unlock(&epdata->lock);
 326         return -ENODEV;
 327 }
 328
 329 static ssize_t
 330 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 331 {
 332         DECLARE_COMPLETION_ONSTACK (done);
 333         int value;
 334
 335         spin_lock_irq (&epdata->dev->lock);
 336         if (likely (epdata->ep != NULL)) {
 337                 struct usb_request      *req = epdata->req;
 338
 339                 req->context = &done;
 340                 req->complete = epio_complete;
 341                 req->buf = buf;
 342                 req->length = len;
 343                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 344         } else
 345                 value = -ENODEV;
 346         spin_unlock_irq (&epdata->dev->lock);
 347
 348         if (likely (value == 0)) {
 349                 value = wait_event_interruptible (done.wait, done.done);
 350                 if (value != 0) {
 351                         spin_lock_irq (&epdata->dev->lock);
 352                         if (likely (epdata->ep != NULL)) {
 353                                 DBG (epdata->dev, "%s i/o interrupted\n",
 354                                                 epdata->name);
 355                                 usb_ep_dequeue (epdata->ep, epdata->req);
 356                                 spin_unlock_irq (&epdata->dev->lock);
 357
 358                                 wait_event (done.wait, done.done);
 359                                 if (epdata->status == -ECONNRESET)
 360                                         epdata->status = -EINTR;
 361                         } else {
 362                                 spin_unlock_irq (&epdata->dev->lock);
 363
 364                                 DBG (epdata->dev, "endpoint gone\n");
 365                                 epdata->status = -ENODEV;
 366                         }
 367                 }
 368                 return epdata->status;
 369         }
 370         return value;
 371 }
 372
 373 static int
 374 ep_release (struct inode *inode, struct file *fd)
 375 {
 376         struct ep_data          *data = fd->private_data;
 377         int value;
 378
 379         value = mutex_lock_interruptible(&data->lock);
 380         if (value < 0)
 381                 return value;
 382
 383         /* clean up if this can be reopened */
 384         if (data->state != STATE_EP_UNBOUND) {
 385                 data->state = STATE_EP_DISABLED;
 386                 data->desc.bDescriptorType = 0;
 387                 data->hs_desc.bDescriptorType = 0;
 388                 usb_ep_disable(data->ep);
 389         }
 390         mutex_unlock(&data->lock);
 391         put_ep (data);
 392         return 0;
 393 }
 394
 395 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
 396 {
 397         struct ep_data          *data = fd->private_data;
 398         int                     status;
 399
 400         if ((status = get_ready_ep (fd->f_flags, data, false)) < 0)
 401                 return status;
 402
 403         spin_lock_irq (&data->dev->lock);
 404         if (likely (data->ep != NULL)) {
 405                 switch (code) {
 406                 case GADGETFS_FIFO_STATUS:
 407                         status = usb_ep_fifo_status (data->ep);
 408                         break;
 409                 case GADGETFS_FIFO_FLUSH:
 410                         usb_ep_fifo_flush (data->ep);
 411                         break;
 412                 case GADGETFS_CLEAR_HALT:
 413                         status = usb_ep_clear_halt (data->ep);
 414                         break;
 415                 default:
 416                         status = -ENOTTY;
 417                 }
 418         } else
 419                 status = -ENODEV;
 420         spin_unlock_irq (&data->dev->lock);
 421         mutex_unlock(&data->lock);
 422         return status;
 423 }
 424
 425 /*----------------------------------------------------------------------*/
 426
 427 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 428
 429 struct kiocb_priv {
 430         struct usb_request      *req;
 431         struct ep_data          *epdata;
 432         struct kiocb            *iocb;
 433         struct mm_struct        *mm;
 434         struct work_struct      work;
 435         void                    *buf;
 436         struct iov_iter         to;
 437         const void              *to_free;
 438         unsigned                actual;
 439 };
 440
 441 static int ep_aio_cancel(struct kiocb *iocb)
 442 {
 443         struct kiocb_priv       *priv = iocb->private;
 444         struct ep_data          *epdata;
 445         int                     value;
 446
 447         local_irq_disable();
 448         epdata = priv->epdata;
 449         // spin_lock(&epdata->dev->lock);
 450         if (likely(epdata && epdata->ep && priv->req))
 451                 value = usb_ep_dequeue (epdata->ep, priv->req);
 452         else
 453                 value = -EINVAL;
 454         // spin_unlock(&epdata->dev->lock);
 455         local_irq_enable();
 456
 457         return value;
 458 }
 459
 460 static void ep_user_copy_worker(struct work_struct *work)
 461 {
 462         struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work);
 463         struct mm_struct *mm = priv->mm;
 464         struct kiocb *iocb = priv->iocb;
 465         size_t ret;
 466
 467         use_mm(mm);
 468         ret = copy_to_iter(priv->buf, priv->actual, &priv->to);
 469         unuse_mm(mm);
 470         if (!ret)
 471                 ret = -EFAULT;
 472
 473         /* completing the iocb can drop the ctx and mm, don't touch mm after */
 474         iocb->ki_complete(iocb, ret, ret);
 475
 476         kfree(priv->buf);
 477         kfree(priv->to_free);
 478         kfree(priv);
 479 }
 480
 481 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 482 {
 483         struct kiocb            *iocb = req->context;
 484         struct kiocb_priv       *priv = iocb->private;
 485         struct ep_data          *epdata = priv->epdata;
 486
 487         /* lock against disconnect (and ideally, cancel) */
 488         spin_lock(&epdata->dev->lock);
 489         priv->req = NULL;
 490         priv->epdata = NULL;
 491
 492         /* if this was a write or a read returning no data then we
 493          * don't need to copy anything to userspace, so we can
 494          * complete the aio request immediately.
 495          */
 496         if (priv->to_free == NULL || unlikely(req->actual == 0)) {
 497                 kfree(req->buf);
 498                 kfree(priv->to_free);
 499                 kfree(priv);
 500                 iocb->private = NULL;
 501                 /* aio_complete() reports bytes-transferred _and_ faults */
 502
 503                 iocb->ki_complete(iocb, req->actual ? req->actual : req->status,
 504                                 req->status);
 505         } else {
 506                 /* ep_copy_to_user() won't report both; we hide some faults */
 507                 if (unlikely(0 != req->status))
 508                         DBG(epdata->dev, "%s fault %d len %d\n",
 509                                 ep->name, req->status, req->actual);
 510
 511                 priv->buf = req->buf;
 512                 priv->actual = req->actual;
 513                 INIT_WORK(&priv->work, ep_user_copy_worker);
 514                 schedule_work(&priv->work);
 515         }
 516         spin_unlock(&epdata->dev->lock);
 517
 518         usb_ep_free_request(ep, req);
 519         put_ep(epdata);
 520 }
 521
 522 static ssize_t ep_aio(struct kiocb *iocb,
 523                       struct kiocb_priv *priv,
 524                       struct ep_data *epdata,
 525                       char *buf,
 526                       size_t len)
 527 {
 528         struct usb_request *req;
 529         ssize_t value;
 530
 531         iocb->private = priv;
 532         priv->iocb = iocb;
 533
 534         kiocb_set_cancel_fn(iocb, ep_aio_cancel);
 535         get_ep(epdata);
 536         priv->epdata = epdata;
 537         priv->actual = 0;
 538         priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */
 539
 540         /* each kiocb is coupled to one usb_request, but we can't
 541          * allocate or submit those if the host disconnected.
 542          */
 543         spin_lock_irq(&epdata->dev->lock);
 544         value = -ENODEV;
 545         if (unlikely(epdata->ep == NULL))
 546                 goto fail;
 547
 548         req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 549         value = -ENOMEM;
 550         if (unlikely(!req))
 551                 goto fail;
 552
 553         priv->req = req;
 554         req->buf = buf;
 555         req->length = len;
 556         req->complete = ep_aio_complete;
 557         req->context = iocb;
 558         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 559         if (unlikely(0 != value)) {
 560                 usb_ep_free_request(epdata->ep, req);
 561                 goto fail;
 562         }
 563         spin_unlock_irq(&epdata->dev->lock);
 564         return -EIOCBQUEUED;
 565
 566 fail:
 567         spin_unlock_irq(&epdata->dev->lock);
 568         kfree(priv->to_free);
 569         kfree(priv);
 570         put_ep(epdata);
 571         return value;
 572 }
 573
 574 static ssize_t
 575 ep_read_iter(struct kiocb *iocb, struct iov_iter *to)
 576 {
 577         struct file *file = iocb->ki_filp;
 578         struct ep_data *epdata = file->private_data;
 579         size_t len = iov_iter_count(to);
 580         ssize_t value;
 581         char *buf;
 582
 583         if ((value = get_ready_ep(file->f_flags, epdata, false)) < 0)
 584                 return value;
 585
 586         /* halt any endpoint by doing a "wrong direction" i/o call */
 587         if (usb_endpoint_dir_in(&epdata->desc)) {
 588                 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
 589                     !is_sync_kiocb(iocb)) {
 590                         mutex_unlock(&epdata->lock);
 591                         return -EINVAL;
 592                 }
 593                 DBG (epdata->dev, "%s halt\n", epdata->name);
 594                 spin_lock_irq(&epdata->dev->lock);
 595                 if (likely(epdata->ep != NULL))
 596                         usb_ep_set_halt(epdata->ep);
 597                 spin_unlock_irq(&epdata->dev->lock);
 598                 mutex_unlock(&epdata->lock);
 599                 return -EBADMSG;
 600         }
 601
 602         buf = kmalloc(len, GFP_KERNEL);
 603         if (unlikely(!buf)) {
 604                 mutex_unlock(&epdata->lock);
 605                 return -ENOMEM;
 606         }
 607         if (is_sync_kiocb(iocb)) {
 608                 value = ep_io(epdata, buf, len);
 609                 if (value >= 0 && (copy_to_iter(buf, value, to) != value))
 610                         value = -EFAULT;
 611         } else {
 612                 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
 613                 value = -ENOMEM;
 614                 if (!priv)
 615                         goto fail;
 616                 priv->to_free = dup_iter(&priv->to, to, GFP_KERNEL);
 617                 if (!priv->to_free) {
 618                         kfree(priv);
 619                         goto fail;
 620                 }
 621                 value = ep_aio(iocb, priv, epdata, buf, len);
 622                 if (value == -EIOCBQUEUED)
 623                         buf = NULL;
 624         }
 625 fail:
 626         kfree(buf);
 627         mutex_unlock(&epdata->lock);
 628         return value;
 629 }
 630
 631 static ssize_t ep_config(struct ep_data *, const char *, size_t);
 632
 633 static ssize_t
 634 ep_write_iter(struct kiocb *iocb, struct iov_iter *from)
 635 {
 636         struct file *file = iocb->ki_filp;
 637         struct ep_data *epdata = file->private_data;
 638         size_t len = iov_iter_count(from);
 639         bool configured;
 640         ssize_t value;
 641         char *buf;
 642
 643         if ((value = get_ready_ep(file->f_flags, epdata, true)) < 0)
 644                 return value;
 645
 646         configured = epdata->state == STATE_EP_ENABLED;
 647
 648         /* halt any endpoint by doing a "wrong direction" i/o call */
 649         if (configured && !usb_endpoint_dir_in(&epdata->desc)) {
 650                 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
 651                     !is_sync_kiocb(iocb)) {
 652                         mutex_unlock(&epdata->lock);
 653                         return -EINVAL;
 654                 }
 655                 DBG (epdata->dev, "%s halt\n", epdata->name);
 656                 spin_lock_irq(&epdata->dev->lock);
 657                 if (likely(epdata->ep != NULL))
 658                         usb_ep_set_halt(epdata->ep);
 659                 spin_unlock_irq(&epdata->dev->lock);
 660                 mutex_unlock(&epdata->lock);
 661                 return -EBADMSG;
 662         }
 663
 664         buf = kmalloc(len, GFP_KERNEL);
 665         if (unlikely(!buf)) {
 666                 mutex_unlock(&epdata->lock);
 667                 return -ENOMEM;
 668         }
 669
 670         if (unlikely(!copy_from_iter_full(buf, len, from))) {
 671                 value = -EFAULT;
 672                 goto out;
 673         }
 674
 675         if (unlikely(!configured)) {
 676                 value = ep_config(epdata, buf, len);
 677         } else if (is_sync_kiocb(iocb)) {
 678                 value = ep_io(epdata, buf, len);
 679         } else {
 680                 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
 681                 value = -ENOMEM;
 682                 if (priv) {
 683                         value = ep_aio(iocb, priv, epdata, buf, len);
 684                         if (value == -EIOCBQUEUED)
 685                                 buf = NULL;
 686                 }
 687         }
 688 out:
 689         kfree(buf);
 690         mutex_unlock(&epdata->lock);
 691         return value;
 692 }
 693
 694 /*----------------------------------------------------------------------*/
 695
 696 /* used after endpoint configuration */
 697 static const struct file_operations ep_io_operations = {
 698         .owner =        THIS_MODULE,
 699
 700         .open =         ep_open,
 701         .release =      ep_release,
 702         .llseek =       no_llseek,
 703         .unlocked_ioctl = ep_ioctl,
 704         .read_iter =    ep_read_iter,
 705         .write_iter =   ep_write_iter,
 706 };
 707
 708 /* ENDPOINT INITIALIZATION
 709  *
 710  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 711  *     status = write (fd, descriptors, sizeof descriptors)
 712  *
 713  * That write establishes the endpoint configuration, configuring
 714  * the controller to process bulk, interrupt, or isochronous transfers
 715  * at the right maxpacket size, and so on.
 716  *
 717  * The descriptors are message type 1, identified by a host order u32
 718  * at the beginning of what's written.  Descriptor order is: full/low
 719  * speed descriptor, then optional high speed descriptor.
 720  */
 721 static ssize_t
 722 ep_config (struct ep_data *data, const char *buf, size_t len)
 723 {
 724         struct usb_ep           *ep;
 725         u32                     tag;
 726         int                     value, length = len;
 727
 728         if (data->state != STATE_EP_READY) {
 729                 value = -EL2HLT;
 730                 goto fail;
 731         }
 732
 733         value = len;
 734         if (len < USB_DT_ENDPOINT_SIZE + 4)
 735                 goto fail0;
 736
 737         /* we might need to change message format someday */
 738         memcpy(&tag, buf, 4);
 739         if (tag != 1) {
 740                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 741                 goto fail0;
 742         }
 743         buf += 4;
 744         len -= 4;
 745
 746         /* NOTE:  audio endpoint extensions not accepted here;
 747          * just don't include the extra bytes.
 748          */
 749
 750         /* full/low speed descriptor, then high speed */
 751         memcpy(&data->desc, buf, USB_DT_ENDPOINT_SIZE);
 752         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 753                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 754                 goto fail0;
 755         if (len != USB_DT_ENDPOINT_SIZE) {
 756                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 757                         goto fail0;
 758                 memcpy(&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 759                         USB_DT_ENDPOINT_SIZE);
 760                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 761                                 || data->hs_desc.bDescriptorType
 762                                         != USB_DT_ENDPOINT) {
 763                         DBG(data->dev, "config %s, bad hs length or type\n",
 764                                         data->name);
 765                         goto fail0;
 766                 }
 767         }
 768
 769         spin_lock_irq (&data->dev->lock);
 770         if (data->dev->state == STATE_DEV_UNBOUND) {
 771                 value = -ENOENT;
 772                 goto gone;
 773         } else {
 774                 ep = data->ep;
 775                 if (ep == NULL) {
 776                         value = -ENODEV;
 777                         goto gone;
 778                 }
 779         }
 780         switch (data->dev->gadget->speed) {
 781         case USB_SPEED_LOW:
 782         case USB_SPEED_FULL:
 783                 ep->desc = &data->desc;
 784                 break;
 785         case USB_SPEED_HIGH:
 786                 /* fails if caller didn't provide that descriptor... */
 787                 ep->desc = &data->hs_desc;
 788                 break;
 789         default:
 790                 DBG(data->dev, "unconnected, %s init abandoned\n",
 791                                 data->name);
 792                 value = -EINVAL;
 793                 goto gone;
 794         }
 795         value = usb_ep_enable(ep);
 796         if (value == 0) {
 797                 data->state = STATE_EP_ENABLED;
 798                 value = length;
 799         }
 800 gone:
 801         spin_unlock_irq (&data->dev->lock);
 802         if (value < 0) {
 803 fail:
 804                 data->desc.bDescriptorType = 0;
 805                 data->hs_desc.bDescriptorType = 0;
 806         }
 807         return value;
 808 fail0:
 809         value = -EINVAL;
 810         goto fail;
 811 }
 812
 813 static int
 814 ep_open (struct inode *inode, struct file *fd)
 815 {
 816         struct ep_data          *data = inode->i_private;
 817         int                     value = -EBUSY;
 818
 819         if (mutex_lock_interruptible(&data->lock) != 0)
 820                 return -EINTR;
 821         spin_lock_irq (&data->dev->lock);
 822         if (data->dev->state == STATE_DEV_UNBOUND)
 823                 value = -ENOENT;
 824         else if (data->state == STATE_EP_DISABLED) {
 825                 value = 0;
 826                 data->state = STATE_EP_READY;
 827                 get_ep (data);
 828                 fd->private_data = data;
 829                 VDEBUG (data->dev, "%s ready\n", data->name);
 830         } else
 831                 DBG (data->dev, "%s state %d\n",
 832                         data->name, data->state);
 833         spin_unlock_irq (&data->dev->lock);
 834         mutex_unlock(&data->lock);
 835         return value;
 836 }
 837
 838 /*----------------------------------------------------------------------*/
 839
 840 /* EP0 IMPLEMENTATION can be partly in userspace.
 841  *
 842  * Drivers that use this facility receive various events, including
 843  * control requests the kernel doesn't handle.  Drivers that don't
 844  * use this facility may be too simple-minded for real applications.
 845  */
 846
 847 static inline void ep0_readable (struct dev_data *dev)
 848 {
 849         wake_up (&dev->wait);
 850         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 851 }
 852
 853 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 854 {
 855         struct dev_data         *dev = ep->driver_data;
 856
 857         if (req->buf != dev->rbuf) {
 858                 kfree(req->buf);
 859                 req->buf = dev->rbuf;
 860         }
 861         req->complete = epio_complete;
 862         dev->setup_out_ready = 0;
 863 }
 864
 865 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 866 {
 867         struct dev_data         *dev = ep->driver_data;
 868         unsigned long           flags;
 869         int                     free = 1;
 870
 871         /* for control OUT, data must still get to userspace */
 872         spin_lock_irqsave(&dev->lock, flags);
 873         if (!dev->setup_in) {
 874                 dev->setup_out_error = (req->status != 0);
 875                 if (!dev->setup_out_error)
 876                         free = 0;
 877                 dev->setup_out_ready = 1;
 878                 ep0_readable (dev);
 879         }
 880
 881         /* clean up as appropriate */
 882         if (free && req->buf != &dev->rbuf)
 883                 clean_req (ep, req);
 884         req->complete = epio_complete;
 885         spin_unlock_irqrestore(&dev->lock, flags);
 886 }
 887
 888 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 889 {
 890         struct dev_data *dev = ep->driver_data;
 891
 892         if (dev->setup_out_ready) {
 893                 DBG (dev, "ep0 request busy!\n");
 894                 return -EBUSY;
 895         }
 896         if (len > sizeof (dev->rbuf))
 897                 req->buf = kmalloc(len, GFP_ATOMIC);
 898         if (req->buf == NULL) {
 899                 req->buf = dev->rbuf;
 900                 return -ENOMEM;
 901         }
 902         req->complete = ep0_complete;
 903         req->length = len;
 904         req->zero = 0;
 905         return 0;
 906 }
 907
 908 static ssize_t
 909 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 910 {
 911         struct dev_data                 *dev = fd->private_data;
 912         ssize_t                         retval;
 913         enum ep0_state                  state;
 914
 915         spin_lock_irq (&dev->lock);
 916         if (dev->state <= STATE_DEV_OPENED) {
 917                 retval = -EINVAL;
 918                 goto done;
 919         }
 920
 921         /* report fd mode change before acting on it */
 922         if (dev->setup_abort) {
 923                 dev->setup_abort = 0;
 924                 retval = -EIDRM;
 925                 goto done;
 926         }
 927
 928         /* control DATA stage */
 929         if ((state = dev->state) == STATE_DEV_SETUP) {
 930
 931                 if (dev->setup_in) {            /* stall IN */
 932                         VDEBUG(dev, "ep0in stall\n");
 933                         (void) usb_ep_set_halt (dev->gadget->ep0);
 934                         retval = -EL2HLT;
 935                         dev->state = STATE_DEV_CONNECTED;
 936
 937                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
 938                         struct usb_ep           *ep = dev->gadget->ep0;
 939                         struct usb_request      *req = dev->req;
 940
 941                         if ((retval = setup_req (ep, req, 0)) == 0) {
 942                                 spin_unlock_irq (&dev->lock);
 943                                 retval = usb_ep_queue (ep, req, GFP_KERNEL);
 944                                 spin_lock_irq (&dev->lock);
 945                         }
 946                         dev->state = STATE_DEV_CONNECTED;
 947
 948                         /* assume that was SET_CONFIGURATION */
 949                         if (dev->current_config) {
 950                                 unsigned power;
 951
 952                                 if (gadget_is_dualspeed(dev->gadget)
 953                                                 && (dev->gadget->speed
 954                                                         == USB_SPEED_HIGH))
 955                                         power = dev->hs_config->bMaxPower;
 956                                 else
 957                                         power = dev->config->bMaxPower;
 958                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
 959                         }
 960
 961                 } else {                        /* collect OUT data */
 962                         if ((fd->f_flags & O_NONBLOCK) != 0
 963                                         && !dev->setup_out_ready) {
 964                                 retval = -EAGAIN;
 965                                 goto done;
 966                         }
 967                         spin_unlock_irq (&dev->lock);
 968                         retval = wait_event_interruptible (dev->wait,
 969                                         dev->setup_out_ready != 0);
 970
 971                         /* FIXME state could change from under us */
 972                         spin_lock_irq (&dev->lock);
 973                         if (retval)
 974                                 goto done;
 975
 976                         if (dev->state != STATE_DEV_SETUP) {
 977                                 retval = -ECANCELED;
 978                                 goto done;
 979                         }
 980                         dev->state = STATE_DEV_CONNECTED;
 981
 982                         if (dev->setup_out_error)
 983                                 retval = -EIO;
 984                         else {
 985                                 len = min (len, (size_t)dev->req->actual);
 986 // FIXME don't call this with the spinlock held ...
 987                                 if (copy_to_user (buf, dev->req->buf, len))
 988                                         retval = -EFAULT;
 989                                 else
 990                                         retval = len;
 991                                 clean_req (dev->gadget->ep0, dev->req);
 992                                 /* NOTE userspace can't yet choose to stall */
 993                         }
 994                 }
 995                 goto done;
 996         }
 997
 998         /* else normal: return event data */
 999         if (len < sizeof dev->event [0]) {
1000                 retval = -EINVAL;
1001                 goto done;
1002         }
1003         len -= len % sizeof (struct usb_gadgetfs_event);
1004         dev->usermode_setup = 1;
1005
1006 scan:
1007         /* return queued events right away */
1008         if (dev->ev_next != 0) {
1009                 unsigned                i, n;
1010
1011                 n = len / sizeof (struct usb_gadgetfs_event);
1012                 if (dev->ev_next < n)
1013                         n = dev->ev_next;
1014
1015                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1016                 for (i = 0; i < n; i++) {
1017                         if (dev->event [i].type == GADGETFS_SETUP) {
1018                                 dev->state = STATE_DEV_SETUP;
1019                                 n = i + 1;
1020                                 break;
1021                         }
1022                 }
1023                 spin_unlock_irq (&dev->lock);
1024                 len = n * sizeof (struct usb_gadgetfs_event);
1025                 if (copy_to_user (buf, &dev->event, len))
1026                         retval = -EFAULT;
1027                 else
1028                         retval = len;
1029                 if (len > 0) {
1030                         /* NOTE this doesn't guard against broken drivers;
1031                          * concurrent ep0 readers may lose events.
1032                          */
1033                         spin_lock_irq (&dev->lock);
1034                         if (dev->ev_next > n) {
1035                                 memmove(&dev->event[0], &dev->event[n],
1036                                         sizeof (struct usb_gadgetfs_event)
1037                                                 * (dev->ev_next - n));
1038                         }
1039                         dev->ev_next -= n;
1040                         spin_unlock_irq (&dev->lock);
1041                 }
1042                 return retval;
1043         }
1044         if (fd->f_flags & O_NONBLOCK) {
1045                 retval = -EAGAIN;
1046                 goto done;
1047         }
1048
1049         switch (state) {
1050         default:
1051                 DBG (dev, "fail %s, state %d\n", __func__, state);
1052                 retval = -ESRCH;
1053                 break;
1054         case STATE_DEV_UNCONNECTED:
1055         case STATE_DEV_CONNECTED:
1056                 spin_unlock_irq (&dev->lock);
1057                 DBG (dev, "%s wait\n", __func__);
1058
1059                 /* wait for events */
1060                 retval = wait_event_interruptible (dev->wait,
1061                                 dev->ev_next != 0);
1062                 if (retval < 0)
1063                         return retval;
1064                 spin_lock_irq (&dev->lock);
1065                 goto scan;
1066         }
1067
1068 done:
1069         spin_unlock_irq (&dev->lock);
1070         return retval;
1071 }
1072
1073 static struct usb_gadgetfs_event *
1074 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1075 {
1076         struct usb_gadgetfs_event       *event;
1077         unsigned                        i;
1078
1079         switch (type) {
1080         /* these events purge the queue */
1081         case GADGETFS_DISCONNECT:
1082                 if (dev->state == STATE_DEV_SETUP)
1083                         dev->setup_abort = 1;
1084                 // FALL THROUGH
1085         case GADGETFS_CONNECT:
1086                 dev->ev_next = 0;
1087                 break;
1088         case GADGETFS_SETUP:            /* previous request timed out */
1089         case GADGETFS_SUSPEND:          /* same effect */
1090                 /* these events can't be repeated */
1091                 for (i = 0; i != dev->ev_next; i++) {
1092                         if (dev->event [i].type != type)
1093                                 continue;
1094                         DBG(dev, "discard old event[%d] %d\n", i, type);
1095                         dev->ev_next--;
1096                         if (i == dev->ev_next)
1097                                 break;
1098                         /* indices start at zero, for simplicity */
1099                         memmove (&dev->event [i], &dev->event [i + 1],
1100                                 sizeof (struct usb_gadgetfs_event)
1101                                         * (dev->ev_next - i));
1102                 }
1103                 break;
1104         default:
1105                 BUG ();
1106         }
1107         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1108         event = &dev->event [dev->ev_next++];
1109         BUG_ON (dev->ev_next > N_EVENT);
1110         memset (event, 0, sizeof *event);
1111         event->type = type;
1112         return event;
1113 }
1114
1115 static ssize_t
1116 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1117 {
1118         struct dev_data         *dev = fd->private_data;
1119         ssize_t                 retval = -ESRCH;
1120
1121         /* report fd mode change before acting on it */
1122         if (dev->setup_abort) {
1123                 dev->setup_abort = 0;
1124                 retval = -EIDRM;
1125
1126         /* data and/or status stage for control request */
1127         } else if (dev->state == STATE_DEV_SETUP) {
1128
1129                 len = min_t(size_t, len, dev->setup_wLength);
1130                 if (dev->setup_in) {
1131                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1132                         if (retval == 0) {
1133                                 dev->state = STATE_DEV_CONNECTED;
1134                                 spin_unlock_irq (&dev->lock);
1135                                 if (copy_from_user (dev->req->buf, buf, len))
1136                                         retval = -EFAULT;
1137                                 else {
1138                                         if (len < dev->setup_wLength)
1139                                                 dev->req->zero = 1;
1140                                         retval = usb_ep_queue (
1141                                                 dev->gadget->ep0, dev->req,
1142                                                 GFP_KERNEL);
1143                                 }
1144                                 spin_lock_irq(&dev->lock);
1145                                 if (retval < 0) {
1146                                         clean_req (dev->gadget->ep0, dev->req);
1147                                 } else
1148                                         retval = len;
1149
1150                                 return retval;
1151                         }
1152
1153                 /* can stall some OUT transfers */
1154                 } else if (dev->setup_can_stall) {
1155                         VDEBUG(dev, "ep0out stall\n");
1156                         (void) usb_ep_set_halt (dev->gadget->ep0);
1157                         retval = -EL2HLT;
1158                         dev->state = STATE_DEV_CONNECTED;
1159                 } else {
1160                         DBG(dev, "bogus ep0out stall!\n");
1161                 }
1162         } else
1163                 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1164
1165         return retval;
1166 }
1167
1168 static int
1169 ep0_fasync (int f, struct file *fd, int on)
1170 {
1171         struct dev_data         *dev = fd->private_data;
1172         // caller must F_SETOWN before signal delivery happens
1173         VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1174         return fasync_helper (f, fd, on, &dev->fasync);
1175 }
1176
1177 static struct usb_gadget_driver gadgetfs_driver;
1178
1179 static int
1180 dev_release (struct inode *inode, struct file *fd)
1181 {
1182         struct dev_data         *dev = fd->private_data;
1183
1184         /* closing ep0 === shutdown all */
1185
1186         if (dev->gadget_registered) {
1187                 usb_gadget_unregister_driver (&gadgetfs_driver);
1188                 dev->gadget_registered = false;
1189         }
1190
1191         /* at this point "good" hardware has disconnected the
1192          * device from USB; the host won't see it any more.
1193          * alternatively, all host requests will time out.
1194          */
1195
1196         kfree (dev->buf);
1197         dev->buf = NULL;
1198
1199         /* other endpoints were all decoupled from this device */
1200         spin_lock_irq(&dev->lock);
1201         dev->state = STATE_DEV_DISABLED;
1202         spin_unlock_irq(&dev->lock);
1203
1204         put_dev (dev);
1205         return 0;
1206 }
1207
1208 static unsigned int
1209 ep0_poll (struct file *fd, poll_table *wait)
1210 {
1211        struct dev_data         *dev = fd->private_data;
1212        int                     mask = 0;
1213
1214         if (dev->state <= STATE_DEV_OPENED)
1215                 return DEFAULT_POLLMASK;
1216
1217        poll_wait(fd, &dev->wait, wait);
1218
1219        spin_lock_irq (&dev->lock);
1220
1221        /* report fd mode change before acting on it */
1222        if (dev->setup_abort) {
1223                dev->setup_abort = 0;
1224                mask = POLLHUP;
1225                goto out;
1226        }
1227
1228        if (dev->state == STATE_DEV_SETUP) {
1229                if (dev->setup_in || dev->setup_can_stall)
1230                        mask = POLLOUT;
1231        } else {
1232                if (dev->ev_next != 0)
1233                        mask = POLLIN;
1234        }
1235 out:
1236        spin_unlock_irq(&dev->lock);
1237        return mask;
1238 }
1239
1240 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1241 {
1242         struct dev_data         *dev = fd->private_data;
1243         struct usb_gadget       *gadget = dev->gadget;
1244         long ret = -ENOTTY;
1245
1246         if (gadget->ops->ioctl)
1247                 ret = gadget->ops->ioctl (gadget, code, value);
1248
1249         return ret;
1250 }
1251
1252 /*----------------------------------------------------------------------*/
1253
1254 /* The in-kernel gadget driver handles most ep0 issues, in particular
1255  * enumerating the single configuration (as provided from user space).
1256  *
1257  * Unrecognized ep0 requests may be handled in user space.
1258  */
1259
1260 static void make_qualifier (struct dev_data *dev)
1261 {
1262         struct usb_qualifier_descriptor         qual;
1263         struct usb_device_descriptor            *desc;
1264
1265         qual.bLength = sizeof qual;
1266         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1267         qual.bcdUSB = cpu_to_le16 (0x0200);
1268
1269         desc = dev->dev;
1270         qual.bDeviceClass = desc->bDeviceClass;
1271         qual.bDeviceSubClass = desc->bDeviceSubClass;
1272         qual.bDeviceProtocol = desc->bDeviceProtocol;
1273
1274         /* assumes ep0 uses the same value for both speeds ... */
1275         qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1276
1277         qual.bNumConfigurations = 1;
1278         qual.bRESERVED = 0;
1279
1280         memcpy (dev->rbuf, &qual, sizeof qual);
1281 }
1282
1283 static int
1284 config_buf (struct dev_data *dev, u8 type, unsigned index)
1285 {
1286         int             len;
1287         int             hs = 0;
1288
1289         /* only one configuration */
1290         if (index > 0)
1291                 return -EINVAL;
1292
1293         if (gadget_is_dualspeed(dev->gadget)) {
1294                 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1295                 if (type == USB_DT_OTHER_SPEED_CONFIG)
1296                         hs = !hs;
1297         }
1298         if (hs) {
1299                 dev->req->buf = dev->hs_config;
1300                 len = le16_to_cpu(dev->hs_config->wTotalLength);
1301         } else {
1302                 dev->req->buf = dev->config;
1303                 len = le16_to_cpu(dev->config->wTotalLength);
1304         }
1305         ((u8 *)dev->req->buf) [1] = type;
1306         return len;
1307 }
1308
1309 static int
1310 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1311 {
1312         struct dev_data                 *dev = get_gadget_data (gadget);
1313         struct usb_request              *req = dev->req;
1314         int                             value = -EOPNOTSUPP;
1315         struct usb_gadgetfs_event       *event;
1316         u16                             w_value = le16_to_cpu(ctrl->wValue);
1317         u16                             w_length = le16_to_cpu(ctrl->wLength);
1318
1319         spin_lock (&dev->lock);
1320         dev->setup_abort = 0;
1321         if (dev->state == STATE_DEV_UNCONNECTED) {
1322                 if (gadget_is_dualspeed(gadget)
1323                                 && gadget->speed == USB_SPEED_HIGH
1324                                 && dev->hs_config == NULL) {
1325                         spin_unlock(&dev->lock);
1326                         ERROR (dev, "no high speed config??\n");
1327                         return -EINVAL;
1328                 }
1329
1330                 dev->state = STATE_DEV_CONNECTED;
1331
1332                 INFO (dev, "connected\n");
1333                 event = next_event (dev, GADGETFS_CONNECT);
1334                 event->u.speed = gadget->speed;
1335                 ep0_readable (dev);
1336
1337         /* host may have given up waiting for response.  we can miss control
1338          * requests handled lower down (device/endpoint status and features);
1339          * then ep0_{read,write} will report the wrong status. controller
1340          * driver will have aborted pending i/o.
1341          */
1342         } else if (dev->state == STATE_DEV_SETUP)
1343                 dev->setup_abort = 1;
1344
1345         req->buf = dev->rbuf;
1346         req->context = NULL;
1347         value = -EOPNOTSUPP;
1348         switch (ctrl->bRequest) {
1349
1350         case USB_REQ_GET_DESCRIPTOR:
1351                 if (ctrl->bRequestType != USB_DIR_IN)
1352                         goto unrecognized;
1353                 switch (w_value >> 8) {
1354
1355                 case USB_DT_DEVICE:
1356                         value = min (w_length, (u16) sizeof *dev->dev);
1357                         dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1358                         req->buf = dev->dev;
1359                         break;
1360                 case USB_DT_DEVICE_QUALIFIER:
1361                         if (!dev->hs_config)
1362                                 break;
1363                         value = min (w_length, (u16)
1364                                 sizeof (struct usb_qualifier_descriptor));
1365                         make_qualifier (dev);
1366                         break;
1367                 case USB_DT_OTHER_SPEED_CONFIG:
1368                         // FALLTHROUGH
1369                 case USB_DT_CONFIG:
1370                         value = config_buf (dev,
1371                                         w_value >> 8,
1372                                         w_value & 0xff);
1373                         if (value >= 0)
1374                                 value = min (w_length, (u16) value);
1375                         break;
1376                 case USB_DT_STRING:
1377                         goto unrecognized;
1378
1379                 default:                // all others are errors
1380                         break;
1381                 }
1382                 break;
1383
1384         /* currently one config, two speeds */
1385         case USB_REQ_SET_CONFIGURATION:
1386                 if (ctrl->bRequestType != 0)
1387                         goto unrecognized;
1388                 if (0 == (u8) w_value) {
1389                         value = 0;
1390                         dev->current_config = 0;
1391                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1392                         // user mode expected to disable endpoints
1393                 } else {
1394                         u8      config, power;
1395
1396                         if (gadget_is_dualspeed(gadget)
1397                                         && gadget->speed == USB_SPEED_HIGH) {
1398                                 config = dev->hs_config->bConfigurationValue;
1399                                 power = dev->hs_config->bMaxPower;
1400                         } else {
1401                                 config = dev->config->bConfigurationValue;
1402                                 power = dev->config->bMaxPower;
1403                         }
1404
1405                         if (config == (u8) w_value) {
1406                                 value = 0;
1407                                 dev->current_config = config;
1408                                 usb_gadget_vbus_draw(gadget, 2 * power);
1409                         }
1410                 }
1411
1412                 /* report SET_CONFIGURATION like any other control request,
1413                  * except that usermode may not stall this.  the next
1414                  * request mustn't be allowed start until this finishes:
1415                  * endpoints and threads set up, etc.
1416                  *
1417                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1418                  * has bad/racey automagic that prevents synchronizing here.
1419                  * even kernel mode drivers often miss them.
1420                  */
1421                 if (value == 0) {
1422                         INFO (dev, "configuration #%d\n", dev->current_config);
1423                         usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
1424                         if (dev->usermode_setup) {
1425                                 dev->setup_can_stall = 0;
1426                                 goto delegate;
1427                         }
1428                 }
1429                 break;
1430
1431 #ifndef CONFIG_USB_PXA25X
1432         /* PXA automagically handles this request too */
1433         case USB_REQ_GET_CONFIGURATION:
1434                 if (ctrl->bRequestType != 0x80)
1435                         goto unrecognized;
1436                 *(u8 *)req->buf = dev->current_config;
1437                 value = min (w_length, (u16) 1);
1438                 break;
1439 #endif
1440
1441         default:
1442 unrecognized:
1443                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1444                         dev->usermode_setup ? "delegate" : "fail",
1445                         ctrl->bRequestType, ctrl->bRequest,
1446                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1447
1448                 /* if there's an ep0 reader, don't stall */
1449                 if (dev->usermode_setup) {
1450                         dev->setup_can_stall = 1;
1451 delegate:
1452                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1453                                                 ? 1 : 0;
1454                         dev->setup_wLength = w_length;
1455                         dev->setup_out_ready = 0;
1456                         dev->setup_out_error = 0;
1457                         value = 0;
1458
1459                         /* read DATA stage for OUT right away */
1460                         if (unlikely (!dev->setup_in && w_length)) {
1461                                 value = setup_req (gadget->ep0, dev->req,
1462                                                         w_length);
1463                                 if (value < 0)
1464                                         break;
1465
1466                                 spin_unlock (&dev->lock);
1467                                 value = usb_ep_queue (gadget->ep0, dev->req,
1468                                                         GFP_KERNEL);
1469                                 spin_lock (&dev->lock);
1470                                 if (value < 0) {
1471                                         clean_req (gadget->ep0, dev->req);
1472                                         break;
1473                                 }
1474
1475                                 /* we can't currently stall these */
1476                                 dev->setup_can_stall = 0;
1477                         }
1478
1479                         /* state changes when reader collects event */
1480                         event = next_event (dev, GADGETFS_SETUP);
1481                         event->u.setup = *ctrl;
1482                         ep0_readable (dev);
1483                         spin_unlock (&dev->lock);
1484                         return 0;
1485                 }
1486         }
1487
1488         /* proceed with data transfer and status phases? */
1489         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1490                 req->length = value;
1491                 req->zero = value < w_length;
1492
1493                 spin_unlock (&dev->lock);
1494                 value = usb_ep_queue (gadget->ep0, req, GFP_KERNEL);
1495                 if (value < 0) {
1496                         DBG (dev, "ep_queue --> %d\n", value);
1497                         req->status = 0;
1498                 }
1499                 return value;
1500         }
1501
1502         /* device stalls when value < 0 */
1503         spin_unlock (&dev->lock);
1504         return value;
1505 }
1506
1507 static void destroy_ep_files (struct dev_data *dev)
1508 {
1509         DBG (dev, "%s %d\n", __func__, dev->state);
1510
1511         /* dev->state must prevent interference */
1512         spin_lock_irq (&dev->lock);
1513         while (!list_empty(&dev->epfiles)) {
1514                 struct ep_data  *ep;
1515                 struct inode    *parent;
1516                 struct dentry   *dentry;
1517
1518                 /* break link to FS */
1519                 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1520                 list_del_init (&ep->epfiles);
1521                 dentry = ep->dentry;
1522                 ep->dentry = NULL;
1523                 parent = d_inode(dentry->d_parent);
1524
1525                 /* break link to controller */
1526                 if (ep->state == STATE_EP_ENABLED)
1527                         (void) usb_ep_disable (ep->ep);
1528                 ep->state = STATE_EP_UNBOUND;
1529                 usb_ep_free_request (ep->ep, ep->req);
1530                 ep->ep = NULL;
1531                 wake_up (&ep->wait);
1532                 put_ep (ep);
1533
1534                 spin_unlock_irq (&dev->lock);
1535
1536                 /* break link to dcache */
1537                 inode_lock(parent);
1538                 d_delete (dentry);
1539                 dput (dentry);
1540                 inode_unlock(parent);
1541
1542                 spin_lock_irq (&dev->lock);
1543         }
1544         spin_unlock_irq (&dev->lock);
1545 }
1546
1547
1548 static struct dentry *
1549 gadgetfs_create_file (struct super_block *sb, char const *name,
1550                 void *data, const struct file_operations *fops);
1551
1552 static int activate_ep_files (struct dev_data *dev)
1553 {
1554         struct usb_ep   *ep;
1555         struct ep_data  *data;
1556
1557         gadget_for_each_ep (ep, dev->gadget) {
1558
1559                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1560                 if (!data)
1561                         goto enomem0;
1562                 data->state = STATE_EP_DISABLED;
1563                 mutex_init(&data->lock);
1564                 init_waitqueue_head (&data->wait);
1565
1566                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1567                 refcount_set (&data->count, 1);
1568                 data->dev = dev;
1569                 get_dev (dev);
1570
1571                 data->ep = ep;
1572                 ep->driver_data = data;
1573
1574                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1575                 if (!data->req)
1576                         goto enomem1;
1577
1578                 data->dentry = gadgetfs_create_file (dev->sb, data->name,
1579                                 data, &ep_io_operations);
1580                 if (!data->dentry)
1581                         goto enomem2;
1582                 list_add_tail (&data->epfiles, &dev->epfiles);
1583         }
1584         return 0;
1585
1586 enomem2:
1587         usb_ep_free_request (ep, data->req);
1588 enomem1:
1589         put_dev (dev);
1590         kfree (data);
1591 enomem0:
1592         DBG (dev, "%s enomem\n", __func__);
1593         destroy_ep_files (dev);
1594         return -ENOMEM;
1595 }
1596
1597 static void
1598 gadgetfs_unbind (struct usb_gadget *gadget)
1599 {
1600         struct dev_data         *dev = get_gadget_data (gadget);
1601
1602         DBG (dev, "%s\n", __func__);
1603
1604         spin_lock_irq (&dev->lock);
1605         dev->state = STATE_DEV_UNBOUND;
1606         spin_unlock_irq (&dev->lock);
1607
1608         destroy_ep_files (dev);
1609         gadget->ep0->driver_data = NULL;
1610         set_gadget_data (gadget, NULL);
1611
1612         /* we've already been disconnected ... no i/o is active */
1613         if (dev->req)
1614                 usb_ep_free_request (gadget->ep0, dev->req);
1615         DBG (dev, "%s done\n", __func__);
1616         put_dev (dev);
1617 }
1618
1619 static struct dev_data          *the_device;
1620
1621 static int gadgetfs_bind(struct usb_gadget *gadget,
1622                 struct usb_gadget_driver *driver)
1623 {
1624         struct dev_data         *dev = the_device;
1625
1626         if (!dev)
1627                 return -ESRCH;
1628         if (0 != strcmp (CHIP, gadget->name)) {
1629                 pr_err("%s expected %s controller not %s\n",
1630                         shortname, CHIP, gadget->name);
1631                 return -ENODEV;
1632         }
1633
1634         set_gadget_data (gadget, dev);
1635         dev->gadget = gadget;
1636         gadget->ep0->driver_data = dev;
1637
1638         /* preallocate control response and buffer */
1639         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1640         if (!dev->req)
1641                 goto enomem;
1642         dev->req->context = NULL;
1643         dev->req->complete = epio_complete;
1644
1645         if (activate_ep_files (dev) < 0)
1646                 goto enomem;
1647
1648         INFO (dev, "bound to %s driver\n", gadget->name);
1649         spin_lock_irq(&dev->lock);
1650         dev->state = STATE_DEV_UNCONNECTED;
1651         spin_unlock_irq(&dev->lock);
1652         get_dev (dev);
1653         return 0;
1654
1655 enomem:
1656         gadgetfs_unbind (gadget);
1657         return -ENOMEM;
1658 }
1659
1660 static void
1661 gadgetfs_disconnect (struct usb_gadget *gadget)
1662 {
1663         struct dev_data         *dev = get_gadget_data (gadget);
1664         unsigned long           flags;
1665
1666         spin_lock_irqsave (&dev->lock, flags);
1667         if (dev->state == STATE_DEV_UNCONNECTED)
1668                 goto exit;
1669         dev->state = STATE_DEV_UNCONNECTED;
1670
1671         INFO (dev, "disconnected\n");
1672         next_event (dev, GADGETFS_DISCONNECT);
1673         ep0_readable (dev);
1674 exit:
1675         spin_unlock_irqrestore (&dev->lock, flags);
1676 }
1677
1678 static void
1679 gadgetfs_suspend (struct usb_gadget *gadget)
1680 {
1681         struct dev_data         *dev = get_gadget_data (gadget);
1682
1683         INFO (dev, "suspended from state %d\n", dev->state);
1684         spin_lock (&dev->lock);
1685         switch (dev->state) {
1686         case STATE_DEV_SETUP:           // VERY odd... host died??
1687         case STATE_DEV_CONNECTED:
1688         case STATE_DEV_UNCONNECTED:
1689                 next_event (dev, GADGETFS_SUSPEND);
1690                 ep0_readable (dev);
1691                 /* FALLTHROUGH */
1692         default:
1693                 break;
1694         }
1695         spin_unlock (&dev->lock);
1696 }
1697
1698 static struct usb_gadget_driver gadgetfs_driver = {
1699         .function       = (char *) driver_desc,
1700         .bind           = gadgetfs_bind,
1701         .unbind         = gadgetfs_unbind,
1702         .setup          = gadgetfs_setup,
1703         .reset          = gadgetfs_disconnect,
1704         .disconnect     = gadgetfs_disconnect,
1705         .suspend        = gadgetfs_suspend,
1706
1707         .driver = {
1708                 .name           = (char *) shortname,
1709         },
1710 };
1711
1712 /*----------------------------------------------------------------------*/
1713 /* DEVICE INITIALIZATION
1714  *
1715  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1716  *     status = write (fd, descriptors, sizeof descriptors)
1717  *
1718  * That write establishes the device configuration, so the kernel can
1719  * bind to the controller ... guaranteeing it can handle enumeration
1720  * at all necessary speeds.  Descriptor order is:
1721  *
1722  * . message tag (u32, host order) ... for now, must be zero; it
1723  *      would change to support features like multi-config devices
1724  * . full/low speed config ... all wTotalLength bytes (with interface,
1725  *      class, altsetting, endpoint, and other descriptors)
1726  * . high speed config ... all descriptors, for high speed operation;
1727  *      this one's optional except for high-speed hardware
1728  * . device descriptor
1729  *
1730  * Endpoints are not yet enabled. Drivers must wait until device
1731  * configuration and interface altsetting changes create
1732  * the need to configure (or unconfigure) them.
1733  *
1734  * After initialization, the device stays active for as long as that
1735  * $CHIP file is open.  Events must then be read from that descriptor,
1736  * such as configuration notifications.
1737  */
1738
1739 static int is_valid_config(struct usb_config_descriptor *config,
1740                 unsigned int total)
1741 {
1742         return config->bDescriptorType == USB_DT_CONFIG
1743                 && config->bLength == USB_DT_CONFIG_SIZE
1744                 && total >= USB_DT_CONFIG_SIZE
1745                 && config->bConfigurationValue != 0
1746                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1747                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1748         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1749         /* FIXME check lengths: walk to end */
1750 }
1751
1752 static ssize_t
1753 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1754 {
1755         struct dev_data         *dev = fd->private_data;
1756         ssize_t                 value = len, length = len;
1757         unsigned                total;
1758         u32                     tag;
1759         char                    *kbuf;
1760
1761         spin_lock_irq(&dev->lock);
1762         if (dev->state > STATE_DEV_OPENED) {
1763                 value = ep0_write(fd, buf, len, ptr);
1764                 spin_unlock_irq(&dev->lock);
1765                 return value;
1766         }
1767         spin_unlock_irq(&dev->lock);
1768
1769         if ((len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) ||
1770             (len > PAGE_SIZE * 4))
1771                 return -EINVAL;
1772
1773         /* we might need to change message format someday */
1774         if (copy_from_user (&tag, buf, 4))
1775                 return -EFAULT;
1776         if (tag != 0)
1777                 return -EINVAL;
1778         buf += 4;
1779         length -= 4;
1780
1781         kbuf = memdup_user(buf, length);
1782         if (IS_ERR(kbuf))
1783                 return PTR_ERR(kbuf);
1784
1785         spin_lock_irq (&dev->lock);
1786         value = -EINVAL;
1787         if (dev->buf) {
1788                 kfree(kbuf);
1789                 goto fail;
1790         }
1791         dev->buf = kbuf;
1792
1793         /* full or low speed config */
1794         dev->config = (void *) kbuf;
1795         total = le16_to_cpu(dev->config->wTotalLength);
1796         if (!is_valid_config(dev->config, total) ||
1797                         total > length - USB_DT_DEVICE_SIZE)
1798                 goto fail;
1799         kbuf += total;
1800         length -= total;
1801
1802         /* optional high speed config */
1803         if (kbuf [1] == USB_DT_CONFIG) {
1804                 dev->hs_config = (void *) kbuf;
1805                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1806                 if (!is_valid_config(dev->hs_config, total) ||
1807                                 total > length - USB_DT_DEVICE_SIZE)
1808                         goto fail;
1809                 kbuf += total;
1810                 length -= total;
1811         } else {
1812                 dev->hs_config = NULL;
1813         }
1814
1815         /* could support multiple configs, using another encoding! */
1816
1817         /* device descriptor (tweaked for paranoia) */
1818         if (length != USB_DT_DEVICE_SIZE)
1819                 goto fail;
1820         dev->dev = (void *)kbuf;
1821         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1822                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1823                         || dev->dev->bNumConfigurations != 1)
1824                 goto fail;
1825         dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1826
1827         /* triggers gadgetfs_bind(); then we can enumerate. */
1828         spin_unlock_irq (&dev->lock);
1829         if (dev->hs_config)
1830                 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1831         else
1832                 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1833
1834         value = usb_gadget_probe_driver(&gadgetfs_driver);
1835         if (value != 0) {
1836                 kfree (dev->buf);
1837                 dev->buf = NULL;
1838         } else {
1839                 /* at this point "good" hardware has for the first time
1840                  * let the USB the host see us.  alternatively, if users
1841                  * unplug/replug that will clear all the error state.
1842                  *
1843                  * note:  everything running before here was guaranteed
1844                  * to choke driver model style diagnostics.  from here
1845                  * on, they can work ... except in cleanup paths that
1846                  * kick in after the ep0 descriptor is closed.
1847                  */
1848                 value = len;
1849                 dev->gadget_registered = true;
1850         }
1851         return value;
1852
1853 fail:
1854         spin_unlock_irq (&dev->lock);
1855         pr_debug ("%s: %s fail %zd, %p\n", shortname, __func__, value, dev);
1856         kfree (dev->buf);
1857         dev->buf = NULL;
1858         return value;
1859 }
1860
1861 static int
1862 dev_open (struct inode *inode, struct file *fd)
1863 {
1864         struct dev_data         *dev = inode->i_private;
1865         int                     value = -EBUSY;
1866
1867         spin_lock_irq(&dev->lock);
1868         if (dev->state == STATE_DEV_DISABLED) {
1869                 dev->ev_next = 0;
1870                 dev->state = STATE_DEV_OPENED;
1871                 fd->private_data = dev;
1872                 get_dev (dev);
1873                 value = 0;
1874         }
1875         spin_unlock_irq(&dev->lock);
1876         return value;
1877 }
1878
1879 static const struct file_operations ep0_operations = {
1880         .llseek =       no_llseek,
1881
1882         .open =         dev_open,
1883         .read =         ep0_read,
1884         .write =        dev_config,
1885         .fasync =       ep0_fasync,
1886         .poll =         ep0_poll,
1887         .unlocked_ioctl = dev_ioctl,
1888         .release =      dev_release,
1889 };
1890
1891 /*----------------------------------------------------------------------*/
1892
1893 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1894  *
1895  * Mounting the filesystem creates a controller file, used first for
1896  * device configuration then later for event monitoring.
1897  */
1898
1899
1900 /* FIXME PAM etc could set this security policy without mount options
1901  * if epfiles inherited ownership and permissons from ep0 ...
1902  */
1903
1904 static unsigned default_uid;
1905 static unsigned default_gid;
1906 static unsigned default_perm = S_IRUSR | S_IWUSR;
1907
1908 module_param (default_uid, uint, 0644);
1909 module_param (default_gid, uint, 0644);
1910 module_param (default_perm, uint, 0644);
1911
1912
1913 static struct inode *
1914 gadgetfs_make_inode (struct super_block *sb,
1915                 void *data, const struct file_operations *fops,
1916                 int mode)
1917 {
1918         struct inode *inode = new_inode (sb);
1919
1920         if (inode) {
1921                 inode->i_ino = get_next_ino();
1922                 inode->i_mode = mode;
1923                 inode->i_uid = make_kuid(&init_user_ns, default_uid);
1924                 inode->i_gid = make_kgid(&init_user_ns, default_gid);
1925                 inode->i_atime = inode->i_mtime = inode->i_ctime
1926                                 = current_time(inode);
1927                 inode->i_private = data;
1928                 inode->i_fop = fops;
1929         }
1930         return inode;
1931 }
1932
1933 /* creates in fs root directory, so non-renamable and non-linkable.
1934  * so inode and dentry are paired, until device reconfig.
1935  */
1936 static struct dentry *
1937 gadgetfs_create_file (struct super_block *sb, char const *name,
1938                 void *data, const struct file_operations *fops)
1939 {
1940         struct dentry   *dentry;
1941         struct inode    *inode;
1942
1943         dentry = d_alloc_name(sb->s_root, name);
1944         if (!dentry)
1945                 return NULL;
1946
1947         inode = gadgetfs_make_inode (sb, data, fops,
1948                         S_IFREG | (default_perm & S_IRWXUGO));
1949         if (!inode) {
1950                 dput(dentry);
1951                 return NULL;
1952         }
1953         d_add (dentry, inode);
1954         return dentry;
1955 }
1956
1957 static const struct super_operations gadget_fs_operations = {
1958         .statfs =       simple_statfs,
1959         .drop_inode =   generic_delete_inode,
1960 };
1961
1962 static int
1963 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
1964 {
1965         struct inode    *inode;
1966         struct dev_data *dev;
1967
1968         if (the_device)
1969                 return -ESRCH;
1970
1971         CHIP = usb_get_gadget_udc_name();
1972         if (!CHIP)
1973                 return -ENODEV;
1974
1975         /* superblock */
1976         sb->s_blocksize = PAGE_SIZE;
1977         sb->s_blocksize_bits = PAGE_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         kfree(CHIP);
2033         CHIP = NULL;
2034 }
2035
2036 /*----------------------------------------------------------------------*/
2037
2038 static struct file_system_type gadgetfs_type = {
2039         .owner          = THIS_MODULE,
2040         .name           = shortname,
2041         .mount          = gadgetfs_mount,
2042         .kill_sb        = gadgetfs_kill_sb,
2043 };
2044 MODULE_ALIAS_FS("gadgetfs");
2045
2046 /*----------------------------------------------------------------------*/
2047
2048 static int __init init (void)
2049 {
2050         int status;
2051
2052         status = register_filesystem (&gadgetfs_type);
2053         if (status == 0)
2054                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2055                         shortname, driver_desc);
2056         return status;
2057 }
2058 module_init (init);
2059
2060 static void __exit cleanup (void)
2061 {
2062         pr_debug ("unregister %s\n", shortname);
2063         unregister_filesystem (&gadgetfs_type);
2064 }
2065 module_exit (cleanup);
2066