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 #include <linux/uio.h>
  30 #include <linux/delay.h>
  31 #include <linux/device.h>
  32 #include <linux/moduleparam.h>
  33
  34 #include <linux/usb/gadgetfs.h>
  35 #include <linux/usb/gadget.h>
  36
  37
  38 /*
  39  * The gadgetfs API maps each endpoint to a file descriptor so that you
  40  * can use standard synchronous read/write calls for I/O.  There's some
  41  * O_NONBLOCK and O_ASYNC/FASYNC style i/o support.  Example usermode
  42  * drivers show how this works in practice.  You can also use AIO to
  43  * eliminate I/O gaps between requests, to help when streaming data.
  44  *
  45  * Key parts that must be USB-specific are protocols defining how the
  46  * read/write operations relate to the hardware state machines.  There
  47  * are two types of files.  One type is for the device, implementing ep0.
  48  * The other type is for each IN or OUT endpoint.  In both cases, the
  49  * user mode driver must configure the hardware before using it.
  50  *
  51  * - First, dev_config() is called when /dev/gadget/$CHIP is configured
  52  *   (by writing configuration and device descriptors).  Afterwards it
  53  *   may serve as a source of device events, used to handle all control
  54  *   requests other than basic enumeration.
  55  *
  56  * - Then, after a SET_CONFIGURATION control request, ep_config() is
  57  *   called when each /dev/gadget/ep* file is configured (by writing
  58  *   endpoint descriptors).  Afterwards these files are used to write()
  59  *   IN data or to read() OUT data.  To halt the endpoint, a "wrong
  60  *   direction" request is issued (like reading an IN endpoint).
  61  *
  62  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
  63  * not possible on all hardware.  For example, precise fault handling with
  64  * respect to data left in endpoint fifos after aborted operations; or
  65  * selective clearing of endpoint halts, to implement SET_INTERFACE.
  66  */
  67
  68 #define DRIVER_DESC     "USB Gadget filesystem"
  69 #define DRIVER_VERSION  "24 Aug 2004"
  70
  71 static const char driver_desc [] = DRIVER_DESC;
  72 static const char shortname [] = "gadgetfs";
  73
  74 MODULE_DESCRIPTION (DRIVER_DESC);
  75 MODULE_AUTHOR ("David Brownell");
  76 MODULE_LICENSE ("GPL");
  77
  78 static int ep_open(struct inode *, struct file *);
  79
  80
  81 /*----------------------------------------------------------------------*/
  82
  83 #define GADGETFS_MAGIC          0xaee71ee7
  84
  85 /* /dev/gadget/$CHIP represents ep0 and the whole device */
  86 enum ep0_state {
  87         /* DISBLED is the initial state.
  88          */
  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         atomic_t                        count;
 119         int                             udc_usage;
 120         enum ep0_state                  state;          /* P: lock */
 121         struct usb_gadgetfs_event       event [N_EVENT];
 122         unsigned                        ev_next;
 123         struct fasync_struct            *fasync;
 124         u8                              current_config;
 125
 126         /* drivers reading ep0 MUST handle control requests (SETUP)
 127          * reported that way; else the host will time out.
 128          */
 129         unsigned                        usermode_setup : 1,
 130                                         setup_in : 1,
 131                                         setup_can_stall : 1,
 132                                         setup_out_ready : 1,
 133                                         setup_out_error : 1,
 134                                         setup_abort : 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         atomic_inc (&data->count);
 155 }
 156
 157 static void put_dev (struct dev_data *data)
 158 {
 159         if (likely (!atomic_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         atomic_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         atomic_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         atomic_inc (&data->count);
 210 }
 211
 212 static void put_ep (struct ep_data *data)
 213 {
 214         if (likely (!atomic_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
 517         usb_ep_free_request(ep, req);
 518         spin_unlock(&epdata->dev->lock);
 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))
 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(buf, len, from) != len)) {
 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                                 ++dev->udc_usage;
 943                                 spin_unlock_irq (&dev->lock);
 944                                 retval = usb_ep_queue (ep, req, GFP_KERNEL);
 945                                 spin_lock_irq (&dev->lock);
 946                                 --dev->udc_usage;
 947                         }
 948                         dev->state = STATE_DEV_CONNECTED;
 949
 950                         /* assume that was SET_CONFIGURATION */
 951                         if (dev->current_config) {
 952                                 unsigned power;
 953
 954                                 if (gadget_is_dualspeed(dev->gadget)
 955                                                 && (dev->gadget->speed
 956                                                         == USB_SPEED_HIGH))
 957                                         power = dev->hs_config->bMaxPower;
 958                                 else
 959                                         power = dev->config->bMaxPower;
 960                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
 961                         }
 962
 963                 } else {                        /* collect OUT data */
 964                         if ((fd->f_flags & O_NONBLOCK) != 0
 965                                         && !dev->setup_out_ready) {
 966                                 retval = -EAGAIN;
 967                                 goto done;
 968                         }
 969                         spin_unlock_irq (&dev->lock);
 970                         retval = wait_event_interruptible (dev->wait,
 971                                         dev->setup_out_ready != 0);
 972
 973                         /* FIXME state could change from under us */
 974                         spin_lock_irq (&dev->lock);
 975                         if (retval)
 976                                 goto done;
 977
 978                         if (dev->state != STATE_DEV_SETUP) {
 979                                 retval = -ECANCELED;
 980                                 goto done;
 981                         }
 982                         dev->state = STATE_DEV_CONNECTED;
 983
 984                         if (dev->setup_out_error)
 985                                 retval = -EIO;
 986                         else {
 987                                 len = min (len, (size_t)dev->req->actual);
 988                                 ++dev->udc_usage;
 989                                 spin_unlock_irq(&dev->lock);
 990                                 if (copy_to_user (buf, dev->req->buf, len))
 991                                         retval = -EFAULT;
 992                                 else
 993                                         retval = len;
 994                                 spin_lock_irq(&dev->lock);
 995                                 --dev->udc_usage;
 996                                 clean_req (dev->gadget->ep0, dev->req);
 997                                 /* NOTE userspace can't yet choose to stall */
 998                         }
 999                 }
1000                 goto done;
1001         }
1002
1003         /* else normal: return event data */
1004         if (len < sizeof dev->event [0]) {
1005                 retval = -EINVAL;
1006                 goto done;
1007         }
1008         len -= len % sizeof (struct usb_gadgetfs_event);
1009         dev->usermode_setup = 1;
1010
1011 scan:
1012         /* return queued events right away */
1013         if (dev->ev_next != 0) {
1014                 unsigned                i, n;
1015
1016                 n = len / sizeof (struct usb_gadgetfs_event);
1017                 if (dev->ev_next < n)
1018                         n = dev->ev_next;
1019
1020                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1021                 for (i = 0; i < n; i++) {
1022                         if (dev->event [i].type == GADGETFS_SETUP) {
1023                                 dev->state = STATE_DEV_SETUP;
1024                                 n = i + 1;
1025                                 break;
1026                         }
1027                 }
1028                 spin_unlock_irq (&dev->lock);
1029                 len = n * sizeof (struct usb_gadgetfs_event);
1030                 if (copy_to_user (buf, &dev->event, len))
1031                         retval = -EFAULT;
1032                 else
1033                         retval = len;
1034                 if (len > 0) {
1035                         /* NOTE this doesn't guard against broken drivers;
1036                          * concurrent ep0 readers may lose events.
1037                          */
1038                         spin_lock_irq (&dev->lock);
1039                         if (dev->ev_next > n) {
1040                                 memmove(&dev->event[0], &dev->event[n],
1041                                         sizeof (struct usb_gadgetfs_event)
1042                                                 * (dev->ev_next - n));
1043                         }
1044                         dev->ev_next -= n;
1045                         spin_unlock_irq (&dev->lock);
1046                 }
1047                 return retval;
1048         }
1049         if (fd->f_flags & O_NONBLOCK) {
1050                 retval = -EAGAIN;
1051                 goto done;
1052         }
1053
1054         switch (state) {
1055         default:
1056                 DBG (dev, "fail %s, state %d\n", __func__, state);
1057                 retval = -ESRCH;
1058                 break;
1059         case STATE_DEV_UNCONNECTED:
1060         case STATE_DEV_CONNECTED:
1061                 spin_unlock_irq (&dev->lock);
1062                 DBG (dev, "%s wait\n", __func__);
1063
1064                 /* wait for events */
1065                 retval = wait_event_interruptible (dev->wait,
1066                                 dev->ev_next != 0);
1067                 if (retval < 0)
1068                         return retval;
1069                 spin_lock_irq (&dev->lock);
1070                 goto scan;
1071         }
1072
1073 done:
1074         spin_unlock_irq (&dev->lock);
1075         return retval;
1076 }
1077
1078 static struct usb_gadgetfs_event *
1079 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1080 {
1081         struct usb_gadgetfs_event       *event;
1082         unsigned                        i;
1083
1084         switch (type) {
1085         /* these events purge the queue */
1086         case GADGETFS_DISCONNECT:
1087                 if (dev->state == STATE_DEV_SETUP)
1088                         dev->setup_abort = 1;
1089                 // FALL THROUGH
1090         case GADGETFS_CONNECT:
1091                 dev->ev_next = 0;
1092                 break;
1093         case GADGETFS_SETUP:            /* previous request timed out */
1094         case GADGETFS_SUSPEND:          /* same effect */
1095                 /* these events can't be repeated */
1096                 for (i = 0; i != dev->ev_next; i++) {
1097                         if (dev->event [i].type != type)
1098                                 continue;
1099                         DBG(dev, "discard old event[%d] %d\n", i, type);
1100                         dev->ev_next--;
1101                         if (i == dev->ev_next)
1102                                 break;
1103                         /* indices start at zero, for simplicity */
1104                         memmove (&dev->event [i], &dev->event [i + 1],
1105                                 sizeof (struct usb_gadgetfs_event)
1106                                         * (dev->ev_next - i));
1107                 }
1108                 break;
1109         default:
1110                 BUG ();
1111         }
1112         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1113         event = &dev->event [dev->ev_next++];
1114         BUG_ON (dev->ev_next > N_EVENT);
1115         memset (event, 0, sizeof *event);
1116         event->type = type;
1117         return event;
1118 }
1119
1120 static ssize_t
1121 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1122 {
1123         struct dev_data         *dev = fd->private_data;
1124         ssize_t                 retval = -ESRCH;
1125
1126         /* report fd mode change before acting on it */
1127         if (dev->setup_abort) {
1128                 dev->setup_abort = 0;
1129                 retval = -EIDRM;
1130
1131         /* data and/or status stage for control request */
1132         } else if (dev->state == STATE_DEV_SETUP) {
1133
1134                 len = min_t(size_t, len, dev->setup_wLength);
1135                 if (dev->setup_in) {
1136                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1137                         if (retval == 0) {
1138                                 dev->state = STATE_DEV_CONNECTED;
1139                                 ++dev->udc_usage;
1140                                 spin_unlock_irq (&dev->lock);
1141                                 if (copy_from_user (dev->req->buf, buf, len))
1142                                         retval = -EFAULT;
1143                                 else {
1144                                         if (len < dev->setup_wLength)
1145                                                 dev->req->zero = 1;
1146                                         retval = usb_ep_queue (
1147                                                 dev->gadget->ep0, dev->req,
1148                                                 GFP_KERNEL);
1149                                 }
1150                                 spin_lock_irq(&dev->lock);
1151                                 --dev->udc_usage;
1152                                 if (retval < 0) {
1153                                         clean_req (dev->gadget->ep0, dev->req);
1154                                 } else
1155                                         retval = len;
1156
1157                                 return retval;
1158                         }
1159
1160                 /* can stall some OUT transfers */
1161                 } else if (dev->setup_can_stall) {
1162                         VDEBUG(dev, "ep0out stall\n");
1163                         (void) usb_ep_set_halt (dev->gadget->ep0);
1164                         retval = -EL2HLT;
1165                         dev->state = STATE_DEV_CONNECTED;
1166                 } else {
1167                         DBG(dev, "bogus ep0out stall!\n");
1168                 }
1169         } else
1170                 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1171
1172         return retval;
1173 }
1174
1175 static int
1176 ep0_fasync (int f, struct file *fd, int on)
1177 {
1178         struct dev_data         *dev = fd->private_data;
1179         // caller must F_SETOWN before signal delivery happens
1180         VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1181         return fasync_helper (f, fd, on, &dev->fasync);
1182 }
1183
1184 static struct usb_gadget_driver gadgetfs_driver;
1185
1186 static int
1187 dev_release (struct inode *inode, struct file *fd)
1188 {
1189         struct dev_data         *dev = fd->private_data;
1190
1191         /* closing ep0 === shutdown all */
1192
1193         usb_gadget_unregister_driver (&gadgetfs_driver);
1194
1195         /* at this point "good" hardware has disconnected the
1196          * device from USB; the host won't see it any more.
1197          * alternatively, all host requests will time out.
1198          */
1199
1200         kfree (dev->buf);
1201         dev->buf = NULL;
1202
1203         /* other endpoints were all decoupled from this device */
1204         spin_lock_irq(&dev->lock);
1205         dev->state = STATE_DEV_DISABLED;
1206         spin_unlock_irq(&dev->lock);
1207
1208         put_dev (dev);
1209         return 0;
1210 }
1211
1212 static unsigned int
1213 ep0_poll (struct file *fd, poll_table *wait)
1214 {
1215        struct dev_data         *dev = fd->private_data;
1216        int                     mask = 0;
1217
1218         if (dev->state <= STATE_DEV_OPENED)
1219                 return DEFAULT_POLLMASK;
1220
1221        poll_wait(fd, &dev->wait, wait);
1222
1223        spin_lock_irq (&dev->lock);
1224
1225        /* report fd mode change before acting on it */
1226        if (dev->setup_abort) {
1227                dev->setup_abort = 0;
1228                mask = POLLHUP;
1229                goto out;
1230        }
1231
1232        if (dev->state == STATE_DEV_SETUP) {
1233                if (dev->setup_in || dev->setup_can_stall)
1234                        mask = POLLOUT;
1235        } else {
1236                if (dev->ev_next != 0)
1237                        mask = POLLIN;
1238        }
1239 out:
1240        spin_unlock_irq(&dev->lock);
1241        return mask;
1242 }
1243
1244 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1245 {
1246         struct dev_data         *dev = fd->private_data;
1247         struct usb_gadget       *gadget = dev->gadget;
1248         long ret = -ENOTTY;
1249
1250         spin_lock_irq(&dev->lock);
1251         if (dev->state == STATE_DEV_OPENED ||
1252                         dev->state == STATE_DEV_UNBOUND) {
1253                 /* Not bound to a UDC */
1254         } else if (gadget->ops->ioctl) {
1255                 ++dev->udc_usage;
1256                 spin_unlock_irq(&dev->lock);
1257
1258                 ret = gadget->ops->ioctl (gadget, code, value);
1259
1260                 spin_lock_irq(&dev->lock);
1261                 --dev->udc_usage;
1262         }
1263         spin_unlock_irq(&dev->lock);
1264
1265         return ret;
1266 }
1267
1268 /*----------------------------------------------------------------------*/
1269
1270 /* The in-kernel gadget driver handles most ep0 issues, in particular
1271  * enumerating the single configuration (as provided from user space).
1272  *
1273  * Unrecognized ep0 requests may be handled in user space.
1274  */
1275
1276 static void make_qualifier (struct dev_data *dev)
1277 {
1278         struct usb_qualifier_descriptor         qual;
1279         struct usb_device_descriptor            *desc;
1280
1281         qual.bLength = sizeof qual;
1282         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1283         qual.bcdUSB = cpu_to_le16 (0x0200);
1284
1285         desc = dev->dev;
1286         qual.bDeviceClass = desc->bDeviceClass;
1287         qual.bDeviceSubClass = desc->bDeviceSubClass;
1288         qual.bDeviceProtocol = desc->bDeviceProtocol;
1289
1290         /* assumes ep0 uses the same value for both speeds ... */
1291         qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1292
1293         qual.bNumConfigurations = 1;
1294         qual.bRESERVED = 0;
1295
1296         memcpy (dev->rbuf, &qual, sizeof qual);
1297 }
1298
1299 static int
1300 config_buf (struct dev_data *dev, u8 type, unsigned index)
1301 {
1302         int             len;
1303         int             hs = 0;
1304
1305         /* only one configuration */
1306         if (index > 0)
1307                 return -EINVAL;
1308
1309         if (gadget_is_dualspeed(dev->gadget)) {
1310                 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1311                 if (type == USB_DT_OTHER_SPEED_CONFIG)
1312                         hs = !hs;
1313         }
1314         if (hs) {
1315                 dev->req->buf = dev->hs_config;
1316                 len = le16_to_cpu(dev->hs_config->wTotalLength);
1317         } else {
1318                 dev->req->buf = dev->config;
1319                 len = le16_to_cpu(dev->config->wTotalLength);
1320         }
1321         ((u8 *)dev->req->buf) [1] = type;
1322         return len;
1323 }
1324
1325 static int
1326 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1327 {
1328         struct dev_data                 *dev = get_gadget_data (gadget);
1329         struct usb_request              *req = dev->req;
1330         int                             value = -EOPNOTSUPP;
1331         struct usb_gadgetfs_event       *event;
1332         u16                             w_value = le16_to_cpu(ctrl->wValue);
1333         u16                             w_length = le16_to_cpu(ctrl->wLength);
1334
1335         spin_lock (&dev->lock);
1336         dev->setup_abort = 0;
1337         if (dev->state == STATE_DEV_UNCONNECTED) {
1338                 if (gadget_is_dualspeed(gadget)
1339                                 && gadget->speed == USB_SPEED_HIGH
1340                                 && dev->hs_config == NULL) {
1341                         spin_unlock(&dev->lock);
1342                         ERROR (dev, "no high speed config??\n");
1343                         return -EINVAL;
1344                 }
1345
1346                 dev->state = STATE_DEV_CONNECTED;
1347
1348                 INFO (dev, "connected\n");
1349                 event = next_event (dev, GADGETFS_CONNECT);
1350                 event->u.speed = gadget->speed;
1351                 ep0_readable (dev);
1352
1353         /* host may have given up waiting for response.  we can miss control
1354          * requests handled lower down (device/endpoint status and features);
1355          * then ep0_{read,write} will report the wrong status. controller
1356          * driver will have aborted pending i/o.
1357          */
1358         } else if (dev->state == STATE_DEV_SETUP)
1359                 dev->setup_abort = 1;
1360
1361         req->buf = dev->rbuf;
1362         req->context = NULL;
1363         switch (ctrl->bRequest) {
1364
1365         case USB_REQ_GET_DESCRIPTOR:
1366                 if (ctrl->bRequestType != USB_DIR_IN)
1367                         goto unrecognized;
1368                 switch (w_value >> 8) {
1369
1370                 case USB_DT_DEVICE:
1371                         value = min (w_length, (u16) sizeof *dev->dev);
1372                         dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1373                         req->buf = dev->dev;
1374                         break;
1375                 case USB_DT_DEVICE_QUALIFIER:
1376                         if (!dev->hs_config)
1377                                 break;
1378                         value = min (w_length, (u16)
1379                                 sizeof (struct usb_qualifier_descriptor));
1380                         make_qualifier (dev);
1381                         break;
1382                 case USB_DT_OTHER_SPEED_CONFIG:
1383                         // FALLTHROUGH
1384                 case USB_DT_CONFIG:
1385                         value = config_buf (dev,
1386                                         w_value >> 8,
1387                                         w_value & 0xff);
1388                         if (value >= 0)
1389                                 value = min (w_length, (u16) value);
1390                         break;
1391                 case USB_DT_STRING:
1392                         goto unrecognized;
1393
1394                 default:                // all others are errors
1395                         break;
1396                 }
1397                 break;
1398
1399         /* currently one config, two speeds */
1400         case USB_REQ_SET_CONFIGURATION:
1401                 if (ctrl->bRequestType != 0)
1402                         goto unrecognized;
1403                 if (0 == (u8) w_value) {
1404                         value = 0;
1405                         dev->current_config = 0;
1406                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1407                         // user mode expected to disable endpoints
1408                 } else {
1409                         u8      config, power;
1410
1411                         if (gadget_is_dualspeed(gadget)
1412                                         && gadget->speed == USB_SPEED_HIGH) {
1413                                 config = dev->hs_config->bConfigurationValue;
1414                                 power = dev->hs_config->bMaxPower;
1415                         } else {
1416                                 config = dev->config->bConfigurationValue;
1417                                 power = dev->config->bMaxPower;
1418                         }
1419
1420                         if (config == (u8) w_value) {
1421                                 value = 0;
1422                                 dev->current_config = config;
1423                                 usb_gadget_vbus_draw(gadget, 2 * power);
1424                         }
1425                 }
1426
1427                 /* report SET_CONFIGURATION like any other control request,
1428                  * except that usermode may not stall this.  the next
1429                  * request mustn't be allowed start until this finishes:
1430                  * endpoints and threads set up, etc.
1431                  *
1432                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1433                  * has bad/racey automagic that prevents synchronizing here.
1434                  * even kernel mode drivers often miss them.
1435                  */
1436                 if (value == 0) {
1437                         INFO (dev, "configuration #%d\n", dev->current_config);
1438                         usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
1439                         if (dev->usermode_setup) {
1440                                 dev->setup_can_stall = 0;
1441                                 goto delegate;
1442                         }
1443                 }
1444                 break;
1445
1446 #ifndef CONFIG_USB_PXA25X
1447         /* PXA automagically handles this request too */
1448         case USB_REQ_GET_CONFIGURATION:
1449                 if (ctrl->bRequestType != 0x80)
1450                         goto unrecognized;
1451                 *(u8 *)req->buf = dev->current_config;
1452                 value = min (w_length, (u16) 1);
1453                 break;
1454 #endif
1455
1456         default:
1457 unrecognized:
1458                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1459                         dev->usermode_setup ? "delegate" : "fail",
1460                         ctrl->bRequestType, ctrl->bRequest,
1461                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1462
1463                 /* if there's an ep0 reader, don't stall */
1464                 if (dev->usermode_setup) {
1465                         dev->setup_can_stall = 1;
1466 delegate:
1467                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1468                                                 ? 1 : 0;
1469                         dev->setup_wLength = w_length;
1470                         dev->setup_out_ready = 0;
1471                         dev->setup_out_error = 0;
1472                         value = 0;
1473
1474                         /* read DATA stage for OUT right away */
1475                         if (unlikely (!dev->setup_in && w_length)) {
1476                                 value = setup_req (gadget->ep0, dev->req,
1477                                                         w_length);
1478                                 if (value < 0)
1479                                         break;
1480
1481                                 ++dev->udc_usage;
1482                                 spin_unlock (&dev->lock);
1483                                 value = usb_ep_queue (gadget->ep0, dev->req,
1484                                                         GFP_KERNEL);
1485                                 spin_lock (&dev->lock);
1486                                 --dev->udc_usage;
1487                                 if (value < 0) {
1488                                         clean_req (gadget->ep0, dev->req);
1489                                         break;
1490                                 }
1491
1492                                 /* we can't currently stall these */
1493                                 dev->setup_can_stall = 0;
1494                         }
1495
1496                         /* state changes when reader collects event */
1497                         event = next_event (dev, GADGETFS_SETUP);
1498                         event->u.setup = *ctrl;
1499                         ep0_readable (dev);
1500                         spin_unlock (&dev->lock);
1501                         return 0;
1502                 }
1503         }
1504
1505         /* proceed with data transfer and status phases? */
1506         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1507                 req->length = value;
1508                 req->zero = value < w_length;
1509
1510                 ++dev->udc_usage;
1511                 spin_unlock (&dev->lock);
1512                 value = usb_ep_queue (gadget->ep0, req, GFP_KERNEL);
1513                 spin_lock(&dev->lock);
1514                 --dev->udc_usage;
1515                 spin_unlock(&dev->lock);
1516                 if (value < 0) {
1517                         DBG (dev, "ep_queue --> %d\n", value);
1518                         req->status = 0;
1519                 }
1520                 return value;
1521         }
1522
1523         /* device stalls when value < 0 */
1524         spin_unlock (&dev->lock);
1525         return value;
1526 }
1527
1528 static void destroy_ep_files (struct dev_data *dev)
1529 {
1530         DBG (dev, "%s %d\n", __func__, dev->state);
1531
1532         /* dev->state must prevent interference */
1533         spin_lock_irq (&dev->lock);
1534         while (!list_empty(&dev->epfiles)) {
1535                 struct ep_data  *ep;
1536                 struct inode    *parent;
1537                 struct dentry   *dentry;
1538
1539                 /* break link to FS */
1540                 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1541                 list_del_init (&ep->epfiles);
1542                 spin_unlock_irq (&dev->lock);
1543
1544                 dentry = ep->dentry;
1545                 ep->dentry = NULL;
1546                 parent = d_inode(dentry->d_parent);
1547
1548                 /* break link to controller */
1549                 mutex_lock(&ep->lock);
1550                 if (ep->state == STATE_EP_ENABLED)
1551                         (void) usb_ep_disable (ep->ep);
1552                 ep->state = STATE_EP_UNBOUND;
1553                 usb_ep_free_request (ep->ep, ep->req);
1554                 ep->ep = NULL;
1555                 mutex_unlock(&ep->lock);
1556
1557                 wake_up (&ep->wait);
1558                 put_ep (ep);
1559
1560                 /* break link to dcache */
1561                 mutex_lock (&parent->i_mutex);
1562                 d_delete (dentry);
1563                 dput (dentry);
1564                 mutex_unlock (&parent->i_mutex);
1565
1566                 spin_lock_irq (&dev->lock);
1567         }
1568         spin_unlock_irq (&dev->lock);
1569 }
1570
1571
1572 static struct dentry *
1573 gadgetfs_create_file (struct super_block *sb, char const *name,
1574                 void *data, const struct file_operations *fops);
1575
1576 static int activate_ep_files (struct dev_data *dev)
1577 {
1578         struct usb_ep   *ep;
1579         struct ep_data  *data;
1580
1581         gadget_for_each_ep (ep, dev->gadget) {
1582
1583                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1584                 if (!data)
1585                         goto enomem0;
1586                 data->state = STATE_EP_DISABLED;
1587                 mutex_init(&data->lock);
1588                 init_waitqueue_head (&data->wait);
1589
1590                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1591                 atomic_set (&data->count, 1);
1592                 data->dev = dev;
1593                 get_dev (dev);
1594
1595                 data->ep = ep;
1596                 ep->driver_data = data;
1597
1598                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1599                 if (!data->req)
1600                         goto enomem1;
1601
1602                 data->dentry = gadgetfs_create_file (dev->sb, data->name,
1603                                 data, &ep_io_operations);
1604                 if (!data->dentry)
1605                         goto enomem2;
1606                 list_add_tail (&data->epfiles, &dev->epfiles);
1607         }
1608         return 0;
1609
1610 enomem2:
1611         usb_ep_free_request (ep, data->req);
1612 enomem1:
1613         put_dev (dev);
1614         kfree (data);
1615 enomem0:
1616         DBG (dev, "%s enomem\n", __func__);
1617         destroy_ep_files (dev);
1618         return -ENOMEM;
1619 }
1620
1621 static void
1622 gadgetfs_unbind (struct usb_gadget *gadget)
1623 {
1624         struct dev_data         *dev = get_gadget_data (gadget);
1625
1626         DBG (dev, "%s\n", __func__);
1627
1628         spin_lock_irq (&dev->lock);
1629         dev->state = STATE_DEV_UNBOUND;
1630         while (dev->udc_usage > 0) {
1631                 spin_unlock_irq(&dev->lock);
1632                 usleep_range(1000, 2000);
1633                 spin_lock_irq(&dev->lock);
1634         }
1635         spin_unlock_irq (&dev->lock);
1636
1637         destroy_ep_files (dev);
1638         gadget->ep0->driver_data = NULL;
1639         set_gadget_data (gadget, NULL);
1640
1641         /* we've already been disconnected ... no i/o is active */
1642         if (dev->req)
1643                 usb_ep_free_request (gadget->ep0, dev->req);
1644         DBG (dev, "%s done\n", __func__);
1645         put_dev (dev);
1646 }
1647
1648 static struct dev_data          *the_device;
1649
1650 static int gadgetfs_bind(struct usb_gadget *gadget,
1651                 struct usb_gadget_driver *driver)
1652 {
1653         struct dev_data         *dev = the_device;
1654
1655         if (!dev)
1656                 return -ESRCH;
1657         if (0 != strcmp (CHIP, gadget->name)) {
1658                 pr_err("%s expected %s controller not %s\n",
1659                         shortname, CHIP, gadget->name);
1660                 return -ENODEV;
1661         }
1662
1663         set_gadget_data (gadget, dev);
1664         dev->gadget = gadget;
1665         gadget->ep0->driver_data = dev;
1666
1667         /* preallocate control response and buffer */
1668         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1669         if (!dev->req)
1670                 goto enomem;
1671         dev->req->context = NULL;
1672         dev->req->complete = epio_complete;
1673
1674         if (activate_ep_files (dev) < 0)
1675                 goto enomem;
1676
1677         INFO (dev, "bound to %s driver\n", gadget->name);
1678         spin_lock_irq(&dev->lock);
1679         dev->state = STATE_DEV_UNCONNECTED;
1680         spin_unlock_irq(&dev->lock);
1681         get_dev (dev);
1682         return 0;
1683
1684 enomem:
1685         gadgetfs_unbind (gadget);
1686         return -ENOMEM;
1687 }
1688
1689 static void
1690 gadgetfs_disconnect (struct usb_gadget *gadget)
1691 {
1692         struct dev_data         *dev = get_gadget_data (gadget);
1693         unsigned long           flags;
1694
1695         spin_lock_irqsave (&dev->lock, flags);
1696         if (dev->state == STATE_DEV_UNCONNECTED)
1697                 goto exit;
1698         dev->state = STATE_DEV_UNCONNECTED;
1699
1700         INFO (dev, "disconnected\n");
1701         next_event (dev, GADGETFS_DISCONNECT);
1702         ep0_readable (dev);
1703 exit:
1704         spin_unlock_irqrestore (&dev->lock, flags);
1705 }
1706
1707 static void
1708 gadgetfs_suspend (struct usb_gadget *gadget)
1709 {
1710         struct dev_data         *dev = get_gadget_data (gadget);
1711         unsigned long           flags;
1712
1713         INFO (dev, "suspended from state %d\n", dev->state);
1714         spin_lock_irqsave(&dev->lock, flags);
1715         switch (dev->state) {
1716         case STATE_DEV_SETUP:           // VERY odd... host died??
1717         case STATE_DEV_CONNECTED:
1718         case STATE_DEV_UNCONNECTED:
1719                 next_event (dev, GADGETFS_SUSPEND);
1720                 ep0_readable (dev);
1721                 /* FALLTHROUGH */
1722         default:
1723                 break;
1724         }
1725         spin_unlock_irqrestore(&dev->lock, flags);
1726 }
1727
1728 static struct usb_gadget_driver gadgetfs_driver = {
1729         .function       = (char *) driver_desc,
1730         .bind           = gadgetfs_bind,
1731         .unbind         = gadgetfs_unbind,
1732         .setup          = gadgetfs_setup,
1733         .reset          = gadgetfs_disconnect,
1734         .disconnect     = gadgetfs_disconnect,
1735         .suspend        = gadgetfs_suspend,
1736
1737         .driver = {
1738                 .name           = (char *) shortname,
1739         },
1740 };
1741
1742 /*----------------------------------------------------------------------*/
1743
1744 static void gadgetfs_nop(struct usb_gadget *arg) { }
1745
1746 static int gadgetfs_probe(struct usb_gadget *gadget,
1747                 struct usb_gadget_driver *driver)
1748 {
1749         CHIP = gadget->name;
1750         return -EISNAM;
1751 }
1752
1753 static struct usb_gadget_driver probe_driver = {
1754         .max_speed      = USB_SPEED_HIGH,
1755         .bind           = gadgetfs_probe,
1756         .unbind         = gadgetfs_nop,
1757         .setup          = (void *)gadgetfs_nop,
1758         .disconnect     = gadgetfs_nop,
1759         .driver = {
1760                 .name           = "nop",
1761         },
1762 };
1763
1764
1765 /* DEVICE INITIALIZATION
1766  *
1767  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1768  *     status = write (fd, descriptors, sizeof descriptors)
1769  *
1770  * That write establishes the device configuration, so the kernel can
1771  * bind to the controller ... guaranteeing it can handle enumeration
1772  * at all necessary speeds.  Descriptor order is:
1773  *
1774  * . message tag (u32, host order) ... for now, must be zero; it
1775  *      would change to support features like multi-config devices
1776  * . full/low speed config ... all wTotalLength bytes (with interface,
1777  *      class, altsetting, endpoint, and other descriptors)
1778  * . high speed config ... all descriptors, for high speed operation;
1779  *      this one's optional except for high-speed hardware
1780  * . device descriptor
1781  *
1782  * Endpoints are not yet enabled. Drivers must wait until device
1783  * configuration and interface altsetting changes create
1784  * the need to configure (or unconfigure) them.
1785  *
1786  * After initialization, the device stays active for as long as that
1787  * $CHIP file is open.  Events must then be read from that descriptor,
1788  * such as configuration notifications.
1789  */
1790
1791 static int is_valid_config(struct usb_config_descriptor *config,
1792                 unsigned int total)
1793 {
1794         return config->bDescriptorType == USB_DT_CONFIG
1795                 && config->bLength == USB_DT_CONFIG_SIZE
1796                 && total >= USB_DT_CONFIG_SIZE
1797                 && config->bConfigurationValue != 0
1798                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1799                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1800         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1801         /* FIXME check lengths: walk to end */
1802 }
1803
1804 static ssize_t
1805 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1806 {
1807         struct dev_data         *dev = fd->private_data;
1808         ssize_t                 value, length = len;
1809         unsigned                total;
1810         u32                     tag;
1811         char                    *kbuf;
1812
1813         spin_lock_irq(&dev->lock);
1814         if (dev->state > STATE_DEV_OPENED) {
1815                 value = ep0_write(fd, buf, len, ptr);
1816                 spin_unlock_irq(&dev->lock);
1817                 return value;
1818         }
1819         spin_unlock_irq(&dev->lock);
1820
1821         if ((len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) ||
1822             (len > PAGE_SIZE * 4))
1823                 return -EINVAL;
1824
1825         /* we might need to change message format someday */
1826         if (copy_from_user (&tag, buf, 4))
1827                 return -EFAULT;
1828         if (tag != 0)
1829                 return -EINVAL;
1830         buf += 4;
1831         length -= 4;
1832
1833         kbuf = memdup_user(buf, length);
1834         if (IS_ERR(kbuf))
1835                 return PTR_ERR(kbuf);
1836
1837         spin_lock_irq (&dev->lock);
1838         value = -EINVAL;
1839         if (dev->buf) {
1840                 kfree(kbuf);
1841                 goto fail;
1842         }
1843         dev->buf = kbuf;
1844
1845         /* full or low speed config */
1846         dev->config = (void *) kbuf;
1847         total = le16_to_cpu(dev->config->wTotalLength);
1848         if (!is_valid_config(dev->config, total) ||
1849                         total > length - USB_DT_DEVICE_SIZE)
1850                 goto fail;
1851         kbuf += total;
1852         length -= total;
1853
1854         /* optional high speed config */
1855         if (kbuf [1] == USB_DT_CONFIG) {
1856                 dev->hs_config = (void *) kbuf;
1857                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1858                 if (!is_valid_config(dev->hs_config, total) ||
1859                                 total > length - USB_DT_DEVICE_SIZE)
1860                         goto fail;
1861                 kbuf += total;
1862                 length -= total;
1863         } else {
1864                 dev->hs_config = NULL;
1865         }
1866
1867         /* could support multiple configs, using another encoding! */
1868
1869         /* device descriptor (tweaked for paranoia) */
1870         if (length != USB_DT_DEVICE_SIZE)
1871                 goto fail;
1872         dev->dev = (void *)kbuf;
1873         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1874                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1875                         || dev->dev->bNumConfigurations != 1)
1876                 goto fail;
1877         dev->dev->bNumConfigurations = 1;
1878         dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1879
1880         /* triggers gadgetfs_bind(); then we can enumerate. */
1881         spin_unlock_irq (&dev->lock);
1882         if (dev->hs_config)
1883                 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1884         else
1885                 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1886
1887         value = usb_gadget_probe_driver(&gadgetfs_driver);
1888         if (value != 0) {
1889                 kfree (dev->buf);
1890                 dev->buf = NULL;
1891         } else {
1892                 /* at this point "good" hardware has for the first time
1893                  * let the USB the host see us.  alternatively, if users
1894                  * unplug/replug that will clear all the error state.
1895                  *
1896                  * note:  everything running before here was guaranteed
1897                  * to choke driver model style diagnostics.  from here
1898                  * on, they can work ... except in cleanup paths that
1899                  * kick in after the ep0 descriptor is closed.
1900                  */
1901                 value = len;
1902         }
1903         return value;
1904
1905 fail:
1906         spin_unlock_irq (&dev->lock);
1907         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1908         kfree (dev->buf);
1909         dev->buf = NULL;
1910         return value;
1911 }
1912
1913 static int
1914 dev_open (struct inode *inode, struct file *fd)
1915 {
1916         struct dev_data         *dev = inode->i_private;
1917         int                     value = -EBUSY;
1918
1919         spin_lock_irq(&dev->lock);
1920         if (dev->state == STATE_DEV_DISABLED) {
1921                 dev->ev_next = 0;
1922                 dev->state = STATE_DEV_OPENED;
1923                 fd->private_data = dev;
1924                 get_dev (dev);
1925                 value = 0;
1926         }
1927         spin_unlock_irq(&dev->lock);
1928         return value;
1929 }
1930
1931 static const struct file_operations ep0_operations = {
1932         .llseek =       no_llseek,
1933
1934         .open =         dev_open,
1935         .read =         ep0_read,
1936         .write =        dev_config,
1937         .fasync =       ep0_fasync,
1938         .poll =         ep0_poll,
1939         .unlocked_ioctl = dev_ioctl,
1940         .release =      dev_release,
1941 };
1942
1943 /*----------------------------------------------------------------------*/
1944
1945 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1946  *
1947  * Mounting the filesystem creates a controller file, used first for
1948  * device configuration then later for event monitoring.
1949  */
1950
1951
1952 /* FIXME PAM etc could set this security policy without mount options
1953  * if epfiles inherited ownership and permissons from ep0 ...
1954  */
1955
1956 static unsigned default_uid;
1957 static unsigned default_gid;
1958 static unsigned default_perm = S_IRUSR | S_IWUSR;
1959
1960 module_param (default_uid, uint, 0644);
1961 module_param (default_gid, uint, 0644);
1962 module_param (default_perm, uint, 0644);
1963
1964
1965 static struct inode *
1966 gadgetfs_make_inode (struct super_block *sb,
1967                 void *data, const struct file_operations *fops,
1968                 int mode)
1969 {
1970         struct inode *inode = new_inode (sb);
1971
1972         if (inode) {
1973                 inode->i_ino = get_next_ino();
1974                 inode->i_mode = mode;
1975                 inode->i_uid = make_kuid(&init_user_ns, default_uid);
1976                 inode->i_gid = make_kgid(&init_user_ns, default_gid);
1977                 inode->i_atime = inode->i_mtime = inode->i_ctime
1978                                 = CURRENT_TIME;
1979                 inode->i_private = data;
1980                 inode->i_fop = fops;
1981         }
1982         return inode;
1983 }
1984
1985 /* creates in fs root directory, so non-renamable and non-linkable.
1986  * so inode and dentry are paired, until device reconfig.
1987  */
1988 static struct dentry *
1989 gadgetfs_create_file (struct super_block *sb, char const *name,
1990                 void *data, const struct file_operations *fops)
1991 {
1992         struct dentry   *dentry;
1993         struct inode    *inode;
1994
1995         dentry = d_alloc_name(sb->s_root, name);
1996         if (!dentry)
1997                 return NULL;
1998
1999         inode = gadgetfs_make_inode (sb, data, fops,
2000                         S_IFREG | (default_perm & S_IRWXUGO));
2001         if (!inode) {
2002                 dput(dentry);
2003                 return NULL;
2004         }
2005         d_add (dentry, inode);
2006         return dentry;
2007 }
2008
2009 static const struct super_operations gadget_fs_operations = {
2010         .statfs =       simple_statfs,
2011         .drop_inode =   generic_delete_inode,
2012 };
2013
2014 static int
2015 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2016 {
2017         struct inode    *inode;
2018         struct dev_data *dev;
2019
2020         if (the_device)
2021                 return -ESRCH;
2022
2023         /* fake probe to determine $CHIP */
2024         CHIP = NULL;
2025         usb_gadget_probe_driver(&probe_driver);
2026         if (!CHIP)
2027                 return -ENODEV;
2028
2029         /* superblock */
2030         sb->s_blocksize = PAGE_CACHE_SIZE;
2031         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2032         sb->s_magic = GADGETFS_MAGIC;
2033         sb->s_op = &gadget_fs_operations;
2034         sb->s_time_gran = 1;
2035
2036         /* root inode */
2037         inode = gadgetfs_make_inode (sb,
2038                         NULL, &simple_dir_operations,
2039                         S_IFDIR | S_IRUGO | S_IXUGO);
2040         if (!inode)
2041                 goto Enomem;
2042         inode->i_op = &simple_dir_inode_operations;
2043         if (!(sb->s_root = d_make_root (inode)))
2044                 goto Enomem;
2045
2046         /* the ep0 file is named after the controller we expect;
2047          * user mode code can use it for sanity checks, like we do.
2048          */
2049         dev = dev_new ();
2050         if (!dev)
2051                 goto Enomem;
2052
2053         dev->sb = sb;
2054         dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &ep0_operations);
2055         if (!dev->dentry) {
2056                 put_dev(dev);
2057                 goto Enomem;
2058         }
2059
2060         /* other endpoint files are available after hardware setup,
2061          * from binding to a controller.
2062          */
2063         the_device = dev;
2064         return 0;
2065
2066 Enomem:
2067         return -ENOMEM;
2068 }
2069
2070 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2071 static struct dentry *
2072 gadgetfs_mount (struct file_system_type *t, int flags,
2073                 const char *path, void *opts)
2074 {
2075         return mount_single (t, flags, opts, gadgetfs_fill_super);
2076 }
2077
2078 static void
2079 gadgetfs_kill_sb (struct super_block *sb)
2080 {
2081         kill_litter_super (sb);
2082         if (the_device) {
2083                 put_dev (the_device);
2084                 the_device = NULL;
2085         }
2086 }
2087
2088 /*----------------------------------------------------------------------*/
2089
2090 static struct file_system_type gadgetfs_type = {
2091         .owner          = THIS_MODULE,
2092         .name           = shortname,
2093         .mount          = gadgetfs_mount,
2094         .kill_sb        = gadgetfs_kill_sb,
2095 };
2096 MODULE_ALIAS_FS("gadgetfs");
2097
2098 /*----------------------------------------------------------------------*/
2099
2100 static int __init init (void)
2101 {
2102         int status;
2103
2104         status = register_filesystem (&gadgetfs_type);
2105         if (status == 0)
2106                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2107                         shortname, driver_desc);
2108         return status;
2109 }
2110 module_init (init);
2111
2112 static void __exit cleanup (void)
2113 {
2114         pr_debug ("unregister %s\n", shortname);
2115         unregister_filesystem (&gadgetfs_type);
2116 }
2117 module_exit (cleanup);
2118