drivers/usb/gadget/legacy/inode.c

   1 /*
   2  * inode.c -- user mode filesystem api for usb gadget controllers
   3  *
   4  * Copyright (C) 2003-2004 David Brownell
   5  * Copyright (C) 2003 Agilent Technologies
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  */
  12
  13
  14 /* #define VERBOSE_DEBUG */
  15
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/fs.h>
  19 #include <linux/pagemap.h>
  20 #include <linux/uts.h>
  21 #include <linux/wait.h>
  22 #include <linux/compiler.h>
  23 #include <asm/uaccess.h>
  24 #include <linux/sched.h>
  25 #include <linux/slab.h>
  26 #include <linux/poll.h>
  27 #include <linux/mmu_context.h>
  28 #include <linux/aio.h>
  29
  30 #include <linux/device.h>
  31 #include <linux/moduleparam.h>
  32
  33 #include <linux/usb/gadgetfs.h>
  34 #include <linux/usb/gadget.h>
  35
  36
  37 /*
  38  * The gadgetfs API maps each endpoint to a file descriptor so that you
  39  * can use standard synchronous read/write calls for I/O.  There's some
  40  * O_NONBLOCK and O_ASYNC/FASYNC style i/o support.  Example usermode
  41  * drivers show how this works in practice.  You can also use AIO to
  42  * eliminate I/O gaps between requests, to help when streaming data.
  43  *
  44  * Key parts that must be USB-specific are protocols defining how the
  45  * read/write operations relate to the hardware state machines.  There
  46  * are two types of files.  One type is for the device, implementing ep0.
  47  * The other type is for each IN or OUT endpoint.  In both cases, the
  48  * user mode driver must configure the hardware before using it.
  49  *
  50  * - First, dev_config() is called when /dev/gadget/$CHIP is configured
  51  *   (by writing configuration and device descriptors).  Afterwards it
  52  *   may serve as a source of device events, used to handle all control
  53  *   requests other than basic enumeration.
  54  *
  55  * - Then, after a SET_CONFIGURATION control request, ep_config() is
  56  *   called when each /dev/gadget/ep* file is configured (by writing
  57  *   endpoint descriptors).  Afterwards these files are used to write()
  58  *   IN data or to read() OUT data.  To halt the endpoint, a "wrong
  59  *   direction" request is issued (like reading an IN endpoint).
  60  *
  61  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
  62  * not possible on all hardware.  For example, precise fault handling with
  63  * respect to data left in endpoint fifos after aborted operations; or
  64  * selective clearing of endpoint halts, to implement SET_INTERFACE.
  65  */
  66
  67 #define DRIVER_DESC     "USB Gadget filesystem"
  68 #define DRIVER_VERSION  "24 Aug 2004"
  69
  70 static const char driver_desc [] = DRIVER_DESC;
  71 static const char shortname [] = "gadgetfs";
  72
  73 MODULE_DESCRIPTION (DRIVER_DESC);
  74 MODULE_AUTHOR ("David Brownell");
  75 MODULE_LICENSE ("GPL");
  76
  77
  78 /*----------------------------------------------------------------------*/
  79
  80 #define GADGETFS_MAGIC          0xaee71ee7
  81
  82 /* /dev/gadget/$CHIP represents ep0 and the whole device */
  83 enum ep0_state {
  84         /* DISBLED is the initial state.
  85          */
  86         STATE_DEV_DISABLED = 0,
  87
  88         /* Only one open() of /dev/gadget/$CHIP; only one file tracks
  89          * ep0/device i/o modes and binding to the controller.  Driver
  90          * must always write descriptors to initialize the device, then
  91          * the device becomes UNCONNECTED until enumeration.
  92          */
  93         STATE_DEV_OPENED,
  94
  95         /* From then on, ep0 fd is in either of two basic modes:
  96          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
  97          * - SETUP: read/write will transfer control data and succeed;
  98          *   or if "wrong direction", performs protocol stall
  99          */
 100         STATE_DEV_UNCONNECTED,
 101         STATE_DEV_CONNECTED,
 102         STATE_DEV_SETUP,
 103
 104         /* UNBOUND means the driver closed ep0, so the device won't be
 105          * accessible again (DEV_DISABLED) until all fds are closed.
 106          */
 107         STATE_DEV_UNBOUND,
 108 };
 109
 110 /* enough for the whole queue: most events invalidate others */
 111 #define N_EVENT                 5
 112
 113 struct dev_data {
 114         spinlock_t                      lock;
 115         atomic_t                        count;
 116         enum ep0_state                  state;          /* P: lock */
 117         struct usb_gadgetfs_event       event [N_EVENT];
 118         unsigned                        ev_next;
 119         struct fasync_struct            *fasync;
 120         u8                              current_config;
 121
 122         /* drivers reading ep0 MUST handle control requests (SETUP)
 123          * reported that way; else the host will time out.
 124          */
 125         unsigned                        usermode_setup : 1,
 126                                         setup_in : 1,
 127                                         setup_can_stall : 1,
 128                                         setup_out_ready : 1,
 129                                         setup_out_error : 1,
 130                                         setup_abort : 1;
 131         unsigned                        setup_wLength;
 132
 133         /* the rest is basically write-once */
 134         struct usb_config_descriptor    *config, *hs_config;
 135         struct usb_device_descriptor    *dev;
 136         struct usb_request              *req;
 137         struct usb_gadget               *gadget;
 138         struct list_head                epfiles;
 139         void                            *buf;
 140         wait_queue_head_t               wait;
 141         struct super_block              *sb;
 142         struct dentry                   *dentry;
 143
 144         /* except this scratch i/o buffer for ep0 */
 145         u8                              rbuf [256];
 146 };
 147
 148 static inline void get_dev (struct dev_data *data)
 149 {
 150         atomic_inc (&data->count);
 151 }
 152
 153 static void put_dev (struct dev_data *data)
 154 {
 155         if (likely (!atomic_dec_and_test (&data->count)))
 156                 return;
 157         /* needs no more cleanup */
 158         BUG_ON (waitqueue_active (&data->wait));
 159         kfree (data);
 160 }
 161
 162 static struct dev_data *dev_new (void)
 163 {
 164         struct dev_data         *dev;
 165
 166         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 167         if (!dev)
 168                 return NULL;
 169         dev->state = STATE_DEV_DISABLED;
 170         atomic_set (&dev->count, 1);
 171         spin_lock_init (&dev->lock);
 172         INIT_LIST_HEAD (&dev->epfiles);
 173         init_waitqueue_head (&dev->wait);
 174         return dev;
 175 }
 176
 177 /*----------------------------------------------------------------------*/
 178
 179 /* other /dev/gadget/$ENDPOINT files represent endpoints */
 180 enum ep_state {
 181         STATE_EP_DISABLED = 0,
 182         STATE_EP_READY,
 183         STATE_EP_ENABLED,
 184         STATE_EP_UNBOUND,
 185 };
 186
 187 struct ep_data {
 188         struct mutex                    lock;
 189         enum ep_state                   state;
 190         atomic_t                        count;
 191         struct dev_data                 *dev;
 192         /* must hold dev->lock before accessing ep or req */
 193         struct usb_ep                   *ep;
 194         struct usb_request              *req;
 195         ssize_t                         status;
 196         char                            name [16];
 197         struct usb_endpoint_descriptor  desc, hs_desc;
 198         struct list_head                epfiles;
 199         wait_queue_head_t               wait;
 200         struct dentry                   *dentry;
 201 };
 202
 203 static inline void get_ep (struct ep_data *data)
 204 {
 205         atomic_inc (&data->count);
 206 }
 207
 208 static void put_ep (struct ep_data *data)
 209 {
 210         if (likely (!atomic_dec_and_test (&data->count)))
 211                 return;
 212         put_dev (data->dev);
 213         /* needs no more cleanup */
 214         BUG_ON (!list_empty (&data->epfiles));
 215         BUG_ON (waitqueue_active (&data->wait));
 216         kfree (data);
 217 }
 218
 219 /*----------------------------------------------------------------------*/
 220
 221 /* most "how to use the hardware" policy choices are in userspace:
 222  * mapping endpoint roles (which the driver needs) to the capabilities
 223  * which the usb controller has.  most of those capabilities are exposed
 224  * implicitly, starting with the driver name and then endpoint names.
 225  */
 226
 227 static const char *CHIP;
 228
 229 /*----------------------------------------------------------------------*/
 230
 231 /* NOTE:  don't use dev_printk calls before binding to the gadget
 232  * at the end of ep0 configuration, or after unbind.
 233  */
 234
 235 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
 236 #define xprintk(d,level,fmt,args...) \
 237         printk(level "%s: " fmt , shortname , ## args)
 238
 239 #ifdef DEBUG
 240 #define DBG(dev,fmt,args...) \
 241         xprintk(dev , KERN_DEBUG , fmt , ## args)
 242 #else
 243 #define DBG(dev,fmt,args...) \
 244         do { } while (0)
 245 #endif /* DEBUG */
 246
 247 #ifdef VERBOSE_DEBUG
 248 #define VDEBUG  DBG
 249 #else
 250 #define VDEBUG(dev,fmt,args...) \
 251         do { } while (0)
 252 #endif /* DEBUG */
 253
 254 #define ERROR(dev,fmt,args...) \
 255         xprintk(dev , KERN_ERR , fmt , ## args)
 256 #define INFO(dev,fmt,args...) \
 257         xprintk(dev , KERN_INFO , fmt , ## args)
 258
 259
 260 /*----------------------------------------------------------------------*/
 261
 262 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 263  *
 264  * After opening, configure non-control endpoints.  Then use normal
 265  * stream read() and write() requests; and maybe ioctl() to get more
 266  * precise FIFO status when recovering from cancellation.
 267  */
 268
 269 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 270 {
 271         struct ep_data  *epdata = ep->driver_data;
 272
 273         if (!req->context)
 274                 return;
 275         if (req->status)
 276                 epdata->status = req->status;
 277         else
 278                 epdata->status = req->actual;
 279         complete ((struct completion *)req->context);
 280 }
 281
 282 /* tasklock endpoint, returning when it's connected.
 283  * still need dev->lock to use epdata->ep.
 284  */
 285 static int
 286 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
 287 {
 288         int     val;
 289
 290         if (f_flags & O_NONBLOCK) {
 291                 if (!mutex_trylock(&epdata->lock))
 292                         goto nonblock;
 293                 if (epdata->state != STATE_EP_ENABLED) {
 294                         mutex_unlock(&epdata->lock);
 295 nonblock:
 296                         val = -EAGAIN;
 297                 } else
 298                         val = 0;
 299                 return val;
 300         }
 301
 302         val = mutex_lock_interruptible(&epdata->lock);
 303         if (val < 0)
 304                 return val;
 305
 306         switch (epdata->state) {
 307         case STATE_EP_ENABLED:
 308                 break;
 309         // case STATE_EP_DISABLED:              /* "can't happen" */
 310         // case STATE_EP_READY:                 /* "can't happen" */
 311         default:                                /* error! */
 312                 pr_debug ("%s: ep %p not available, state %d\n",
 313                                 shortname, epdata, epdata->state);
 314                 // FALLTHROUGH
 315         case STATE_EP_UNBOUND:                  /* clean disconnect */
 316                 val = -ENODEV;
 317                 mutex_unlock(&epdata->lock);
 318         }
 319         return val;
 320 }
 321
 322 static ssize_t
 323 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 324 {
 325         DECLARE_COMPLETION_ONSTACK (done);
 326         int value;
 327
 328         spin_lock_irq (&epdata->dev->lock);
 329         if (likely (epdata->ep != NULL)) {
 330                 struct usb_request      *req = epdata->req;
 331
 332                 req->context = &done;
 333                 req->complete = epio_complete;
 334                 req->buf = buf;
 335                 req->length = len;
 336                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 337         } else
 338                 value = -ENODEV;
 339         spin_unlock_irq (&epdata->dev->lock);
 340
 341         if (likely (value == 0)) {
 342                 value = wait_event_interruptible (done.wait, done.done);
 343                 if (value != 0) {
 344                         spin_lock_irq (&epdata->dev->lock);
 345                         if (likely (epdata->ep != NULL)) {
 346                                 DBG (epdata->dev, "%s i/o interrupted\n",
 347                                                 epdata->name);
 348                                 usb_ep_dequeue (epdata->ep, epdata->req);
 349                                 spin_unlock_irq (&epdata->dev->lock);
 350
 351                                 wait_event (done.wait, done.done);
 352                                 if (epdata->status == -ECONNRESET)
 353                                         epdata->status = -EINTR;
 354                         } else {
 355                                 spin_unlock_irq (&epdata->dev->lock);
 356
 357                                 DBG (epdata->dev, "endpoint gone\n");
 358                                 epdata->status = -ENODEV;
 359                         }
 360                 }
 361                 return epdata->status;
 362         }
 363         return value;
 364 }
 365
 366
 367 /* handle a synchronous OUT bulk/intr/iso transfer */
 368 static ssize_t
 369 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 370 {
 371         struct ep_data          *data = fd->private_data;
 372         void                    *kbuf;
 373         ssize_t                 value;
 374
 375         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 376                 return value;
 377
 378         /* halt any endpoint by doing a "wrong direction" i/o call */
 379         if (usb_endpoint_dir_in(&data->desc)) {
 380                 if (usb_endpoint_xfer_isoc(&data->desc)) {
 381                         mutex_unlock(&data->lock);
 382                         return -EINVAL;
 383                 }
 384                 DBG (data->dev, "%s halt\n", data->name);
 385                 spin_lock_irq (&data->dev->lock);
 386                 if (likely (data->ep != NULL))
 387                         usb_ep_set_halt (data->ep);
 388                 spin_unlock_irq (&data->dev->lock);
 389                 mutex_unlock(&data->lock);
 390                 return -EBADMSG;
 391         }
 392
 393         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
 394
 395         value = -ENOMEM;
 396         kbuf = kmalloc (len, GFP_KERNEL);
 397         if (unlikely (!kbuf))
 398                 goto free1;
 399
 400         value = ep_io (data, kbuf, len);
 401         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
 402                 data->name, len, (int) value);
 403         if (value >= 0 && copy_to_user (buf, kbuf, value))
 404                 value = -EFAULT;
 405
 406 free1:
 407         mutex_unlock(&data->lock);
 408         kfree (kbuf);
 409         return value;
 410 }
 411
 412 /* handle a synchronous IN bulk/intr/iso transfer */
 413 static ssize_t
 414 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 415 {
 416         struct ep_data          *data = fd->private_data;
 417         void                    *kbuf;
 418         ssize_t                 value;
 419
 420         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 421                 return value;
 422
 423         /* halt any endpoint by doing a "wrong direction" i/o call */
 424         if (!usb_endpoint_dir_in(&data->desc)) {
 425                 if (usb_endpoint_xfer_isoc(&data->desc)) {
 426                         mutex_unlock(&data->lock);
 427                         return -EINVAL;
 428                 }
 429                 DBG (data->dev, "%s halt\n", data->name);
 430                 spin_lock_irq (&data->dev->lock);
 431                 if (likely (data->ep != NULL))
 432                         usb_ep_set_halt (data->ep);
 433                 spin_unlock_irq (&data->dev->lock);
 434                 mutex_unlock(&data->lock);
 435                 return -EBADMSG;
 436         }
 437
 438         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
 439
 440         value = -ENOMEM;
 441         kbuf = memdup_user(buf, len);
 442         if (IS_ERR(kbuf)) {
 443                 value = PTR_ERR(kbuf);
 444                 goto free1;
 445         }
 446
 447         value = ep_io (data, kbuf, len);
 448         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
 449                 data->name, len, (int) value);
 450 free1:
 451         mutex_unlock(&data->lock);
 452         return value;
 453 }
 454
 455 static int
 456 ep_release (struct inode *inode, struct file *fd)
 457 {
 458         struct ep_data          *data = fd->private_data;
 459         int value;
 460
 461         value = mutex_lock_interruptible(&data->lock);
 462         if (value < 0)
 463                 return value;
 464
 465         /* clean up if this can be reopened */
 466         if (data->state != STATE_EP_UNBOUND) {
 467                 data->state = STATE_EP_DISABLED;
 468                 data->desc.bDescriptorType = 0;
 469                 data->hs_desc.bDescriptorType = 0;
 470                 usb_ep_disable(data->ep);
 471         }
 472         mutex_unlock(&data->lock);
 473         put_ep (data);
 474         return 0;
 475 }
 476
 477 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
 478 {
 479         struct ep_data          *data = fd->private_data;
 480         int                     status;
 481
 482         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 483                 return status;
 484
 485         spin_lock_irq (&data->dev->lock);
 486         if (likely (data->ep != NULL)) {
 487                 switch (code) {
 488                 case GADGETFS_FIFO_STATUS:
 489                         status = usb_ep_fifo_status (data->ep);
 490                         break;
 491                 case GADGETFS_FIFO_FLUSH:
 492                         usb_ep_fifo_flush (data->ep);
 493                         break;
 494                 case GADGETFS_CLEAR_HALT:
 495                         status = usb_ep_clear_halt (data->ep);
 496                         break;
 497                 default:
 498                         status = -ENOTTY;
 499                 }
 500         } else
 501                 status = -ENODEV;
 502         spin_unlock_irq (&data->dev->lock);
 503         mutex_unlock(&data->lock);
 504         return status;
 505 }
 506
 507 /*----------------------------------------------------------------------*/
 508
 509 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 510
 511 struct kiocb_priv {
 512         struct usb_request      *req;
 513         struct ep_data          *epdata;
 514         struct kiocb            *iocb;
 515         struct mm_struct        *mm;
 516         struct work_struct      work;
 517         void                    *buf;
 518         const struct iovec      *iv;
 519         unsigned long           nr_segs;
 520         unsigned                actual;
 521 };
 522
 523 static int ep_aio_cancel(struct kiocb *iocb)
 524 {
 525         struct kiocb_priv       *priv = iocb->private;
 526         struct ep_data          *epdata;
 527         int                     value;
 528
 529         local_irq_disable();
 530         epdata = priv->epdata;
 531         // spin_lock(&epdata->dev->lock);
 532         if (likely(epdata && epdata->ep && priv->req))
 533                 value = usb_ep_dequeue (epdata->ep, priv->req);
 534         else
 535                 value = -EINVAL;
 536         // spin_unlock(&epdata->dev->lock);
 537         local_irq_enable();
 538
 539         return value;
 540 }
 541
 542 static ssize_t ep_copy_to_user(struct kiocb_priv *priv)
 543 {
 544         ssize_t                 len, total;
 545         void                    *to_copy;
 546         int                     i;
 547
 548         /* copy stuff into user buffers */
 549         total = priv->actual;
 550         len = 0;
 551         to_copy = priv->buf;
 552         for (i=0; i < priv->nr_segs; i++) {
 553                 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
 554
 555                 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
 556                         if (len == 0)
 557                                 len = -EFAULT;
 558                         break;
 559                 }
 560
 561                 total -= this;
 562                 len += this;
 563                 to_copy += this;
 564                 if (total == 0)
 565                         break;
 566         }
 567
 568         return len;
 569 }
 570
 571 static void ep_user_copy_worker(struct work_struct *work)
 572 {
 573         struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work);
 574         struct mm_struct *mm = priv->mm;
 575         struct kiocb *iocb = priv->iocb;
 576         size_t ret;
 577
 578         use_mm(mm);
 579         ret = ep_copy_to_user(priv);
 580         unuse_mm(mm);
 581
 582         /* completing the iocb can drop the ctx and mm, don't touch mm after */
 583         aio_complete(iocb, ret, ret);
 584
 585         kfree(priv->buf);
 586         kfree(priv);
 587 }
 588
 589 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 590 {
 591         struct kiocb            *iocb = req->context;
 592         struct kiocb_priv       *priv = iocb->private;
 593         struct ep_data          *epdata = priv->epdata;
 594
 595         /* lock against disconnect (and ideally, cancel) */
 596         spin_lock(&epdata->dev->lock);
 597         priv->req = NULL;
 598         priv->epdata = NULL;
 599
 600         /* if this was a write or a read returning no data then we
 601          * don't need to copy anything to userspace, so we can
 602          * complete the aio request immediately.
 603          */
 604         if (priv->iv == NULL || unlikely(req->actual == 0)) {
 605                 kfree(req->buf);
 606                 kfree(priv);
 607                 iocb->private = NULL;
 608                 /* aio_complete() reports bytes-transferred _and_ faults */
 609                 aio_complete(iocb, req->actual ? req->actual : req->status,
 610                                 req->status);
 611         } else {
 612                 /* ep_copy_to_user() won't report both; we hide some faults */
 613                 if (unlikely(0 != req->status))
 614                         DBG(epdata->dev, "%s fault %d len %d\n",
 615                                 ep->name, req->status, req->actual);
 616
 617                 priv->buf = req->buf;
 618                 priv->actual = req->actual;
 619                 schedule_work(&priv->work);
 620         }
 621         spin_unlock(&epdata->dev->lock);
 622
 623         usb_ep_free_request(ep, req);
 624         put_ep(epdata);
 625 }
 626
 627 static ssize_t
 628 ep_aio_rwtail(
 629         struct kiocb    *iocb,
 630         char            *buf,
 631         size_t          len,
 632         struct ep_data  *epdata,
 633         const struct iovec *iv,
 634         unsigned long   nr_segs
 635 )
 636 {
 637         struct kiocb_priv       *priv;
 638         struct usb_request      *req;
 639         ssize_t                 value;
 640
 641         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 642         if (!priv) {
 643                 value = -ENOMEM;
 644 fail:
 645                 kfree(buf);
 646                 return value;
 647         }
 648         iocb->private = priv;
 649         priv->iocb = iocb;
 650         priv->iv = iv;
 651         priv->nr_segs = nr_segs;
 652         INIT_WORK(&priv->work, ep_user_copy_worker);
 653
 654         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 655         if (unlikely(value < 0)) {
 656                 kfree(priv);
 657                 goto fail;
 658         }
 659
 660         kiocb_set_cancel_fn(iocb, ep_aio_cancel);
 661         get_ep(epdata);
 662         priv->epdata = epdata;
 663         priv->actual = 0;
 664         priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */
 665
 666         /* each kiocb is coupled to one usb_request, but we can't
 667          * allocate or submit those if the host disconnected.
 668          */
 669         spin_lock_irq(&epdata->dev->lock);
 670         if (likely(epdata->ep)) {
 671                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 672                 if (likely(req)) {
 673                         priv->req = req;
 674                         req->buf = buf;
 675                         req->length = len;
 676                         req->complete = ep_aio_complete;
 677                         req->context = iocb;
 678                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 679                         if (unlikely(0 != value))
 680                                 usb_ep_free_request(epdata->ep, req);
 681                 } else
 682                         value = -EAGAIN;
 683         } else
 684                 value = -ENODEV;
 685         spin_unlock_irq(&epdata->dev->lock);
 686
 687         mutex_unlock(&epdata->lock);
 688
 689         if (unlikely(value)) {
 690                 kfree(priv);
 691                 put_ep(epdata);
 692         } else
 693                 value = -EIOCBQUEUED;
 694         return value;
 695 }
 696
 697 static ssize_t
 698 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
 699                 unsigned long nr_segs, loff_t o)
 700 {
 701         struct ep_data          *epdata = iocb->ki_filp->private_data;
 702         char                    *buf;
 703
 704         if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
 705                 return -EINVAL;
 706
 707         buf = kmalloc(iocb->ki_nbytes, GFP_KERNEL);
 708         if (unlikely(!buf))
 709                 return -ENOMEM;
 710
 711         return ep_aio_rwtail(iocb, buf, iocb->ki_nbytes, epdata, iov, nr_segs);
 712 }
 713
 714 static ssize_t
 715 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
 716                 unsigned long nr_segs, loff_t o)
 717 {
 718         struct ep_data          *epdata = iocb->ki_filp->private_data;
 719         char                    *buf;
 720         size_t                  len = 0;
 721         int                     i = 0;
 722
 723         if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
 724                 return -EINVAL;
 725
 726         buf = kmalloc(iocb->ki_nbytes, GFP_KERNEL);
 727         if (unlikely(!buf))
 728                 return -ENOMEM;
 729
 730         for (i=0; i < nr_segs; i++) {
 731                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
 732                                 iov[i].iov_len) != 0)) {
 733                         kfree(buf);
 734                         return -EFAULT;
 735                 }
 736                 len += iov[i].iov_len;
 737         }
 738         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
 739 }
 740
 741 /*----------------------------------------------------------------------*/
 742
 743 /* used after endpoint configuration */
 744 static const struct file_operations ep_io_operations = {
 745         .owner =        THIS_MODULE,
 746         .llseek =       no_llseek,
 747
 748         .read =         ep_read,
 749         .write =        ep_write,
 750         .unlocked_ioctl = ep_ioctl,
 751         .release =      ep_release,
 752
 753         .aio_read =     ep_aio_read,
 754         .aio_write =    ep_aio_write,
 755 };
 756
 757 /* ENDPOINT INITIALIZATION
 758  *
 759  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 760  *     status = write (fd, descriptors, sizeof descriptors)
 761  *
 762  * That write establishes the endpoint configuration, configuring
 763  * the controller to process bulk, interrupt, or isochronous transfers
 764  * at the right maxpacket size, and so on.
 765  *
 766  * The descriptors are message type 1, identified by a host order u32
 767  * at the beginning of what's written.  Descriptor order is: full/low
 768  * speed descriptor, then optional high speed descriptor.
 769  */
 770 static ssize_t
 771 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 772 {
 773         struct ep_data          *data = fd->private_data;
 774         struct usb_ep           *ep;
 775         u32                     tag;
 776         int                     value, length = len;
 777
 778         value = mutex_lock_interruptible(&data->lock);
 779         if (value < 0)
 780                 return value;
 781
 782         if (data->state != STATE_EP_READY) {
 783                 value = -EL2HLT;
 784                 goto fail;
 785         }
 786
 787         value = len;
 788         if (len < USB_DT_ENDPOINT_SIZE + 4)
 789                 goto fail0;
 790
 791         /* we might need to change message format someday */
 792         if (copy_from_user (&tag, buf, 4)) {
 793                 goto fail1;
 794         }
 795         if (tag != 1) {
 796                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 797                 goto fail0;
 798         }
 799         buf += 4;
 800         len -= 4;
 801
 802         /* NOTE:  audio endpoint extensions not accepted here;
 803          * just don't include the extra bytes.
 804          */
 805
 806         /* full/low speed descriptor, then high speed */
 807         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 808                 goto fail1;
 809         }
 810         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 811                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 812                 goto fail0;
 813         if (len != USB_DT_ENDPOINT_SIZE) {
 814                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 815                         goto fail0;
 816                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 817                                         USB_DT_ENDPOINT_SIZE)) {
 818                         goto fail1;
 819                 }
 820                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 821                                 || data->hs_desc.bDescriptorType
 822                                         != USB_DT_ENDPOINT) {
 823                         DBG(data->dev, "config %s, bad hs length or type\n",
 824                                         data->name);
 825                         goto fail0;
 826                 }
 827         }
 828
 829         spin_lock_irq (&data->dev->lock);
 830         if (data->dev->state == STATE_DEV_UNBOUND) {
 831                 value = -ENOENT;
 832                 goto gone;
 833         } else if ((ep = data->ep) == NULL) {
 834                 value = -ENODEV;
 835                 goto gone;
 836         }
 837         switch (data->dev->gadget->speed) {
 838         case USB_SPEED_LOW:
 839         case USB_SPEED_FULL:
 840                 ep->desc = &data->desc;
 841                 value = usb_ep_enable(ep);
 842                 if (value == 0)
 843                         data->state = STATE_EP_ENABLED;
 844                 break;
 845         case USB_SPEED_HIGH:
 846                 /* fails if caller didn't provide that descriptor... */
 847                 ep->desc = &data->hs_desc;
 848                 value = usb_ep_enable(ep);
 849                 if (value == 0)
 850                         data->state = STATE_EP_ENABLED;
 851                 break;
 852         default:
 853                 DBG(data->dev, "unconnected, %s init abandoned\n",
 854                                 data->name);
 855                 value = -EINVAL;
 856         }
 857         if (value == 0) {
 858                 fd->f_op = &ep_io_operations;
 859                 value = length;
 860         }
 861 gone:
 862         spin_unlock_irq (&data->dev->lock);
 863         if (value < 0) {
 864 fail:
 865                 data->desc.bDescriptorType = 0;
 866                 data->hs_desc.bDescriptorType = 0;
 867         }
 868         mutex_unlock(&data->lock);
 869         return value;
 870 fail0:
 871         value = -EINVAL;
 872         goto fail;
 873 fail1:
 874         value = -EFAULT;
 875         goto fail;
 876 }
 877
 878 static int
 879 ep_open (struct inode *inode, struct file *fd)
 880 {
 881         struct ep_data          *data = inode->i_private;
 882         int                     value = -EBUSY;
 883
 884         if (mutex_lock_interruptible(&data->lock) != 0)
 885                 return -EINTR;
 886         spin_lock_irq (&data->dev->lock);
 887         if (data->dev->state == STATE_DEV_UNBOUND)
 888                 value = -ENOENT;
 889         else if (data->state == STATE_EP_DISABLED) {
 890                 value = 0;
 891                 data->state = STATE_EP_READY;
 892                 get_ep (data);
 893                 fd->private_data = data;
 894                 VDEBUG (data->dev, "%s ready\n", data->name);
 895         } else
 896                 DBG (data->dev, "%s state %d\n",
 897                         data->name, data->state);
 898         spin_unlock_irq (&data->dev->lock);
 899         mutex_unlock(&data->lock);
 900         return value;
 901 }
 902
 903 /* used before endpoint configuration */
 904 static const struct file_operations ep_config_operations = {
 905         .llseek =       no_llseek,
 906
 907         .open =         ep_open,
 908         .write =        ep_config,
 909         .release =      ep_release,
 910 };
 911
 912 /*----------------------------------------------------------------------*/
 913
 914 /* EP0 IMPLEMENTATION can be partly in userspace.
 915  *
 916  * Drivers that use this facility receive various events, including
 917  * control requests the kernel doesn't handle.  Drivers that don't
 918  * use this facility may be too simple-minded for real applications.
 919  */
 920
 921 static inline void ep0_readable (struct dev_data *dev)
 922 {
 923         wake_up (&dev->wait);
 924         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 925 }
 926
 927 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 928 {
 929         struct dev_data         *dev = ep->driver_data;
 930
 931         if (req->buf != dev->rbuf) {
 932                 kfree(req->buf);
 933                 req->buf = dev->rbuf;
 934         }
 935         req->complete = epio_complete;
 936         dev->setup_out_ready = 0;
 937 }
 938
 939 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 940 {
 941         struct dev_data         *dev = ep->driver_data;
 942         unsigned long           flags;
 943         int                     free = 1;
 944
 945         /* for control OUT, data must still get to userspace */
 946         spin_lock_irqsave(&dev->lock, flags);
 947         if (!dev->setup_in) {
 948                 dev->setup_out_error = (req->status != 0);
 949                 if (!dev->setup_out_error)
 950                         free = 0;
 951                 dev->setup_out_ready = 1;
 952                 ep0_readable (dev);
 953         }
 954
 955         /* clean up as appropriate */
 956         if (free && req->buf != &dev->rbuf)
 957                 clean_req (ep, req);
 958         req->complete = epio_complete;
 959         spin_unlock_irqrestore(&dev->lock, flags);
 960 }
 961
 962 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 963 {
 964         struct dev_data *dev = ep->driver_data;
 965
 966         if (dev->setup_out_ready) {
 967                 DBG (dev, "ep0 request busy!\n");
 968                 return -EBUSY;
 969         }
 970         if (len > sizeof (dev->rbuf))
 971                 req->buf = kmalloc(len, GFP_ATOMIC);
 972         if (req->buf == NULL) {
 973                 req->buf = dev->rbuf;
 974                 return -ENOMEM;
 975         }
 976         req->complete = ep0_complete;
 977         req->length = len;
 978         req->zero = 0;
 979         return 0;
 980 }
 981
 982 static ssize_t
 983 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 984 {
 985         struct dev_data                 *dev = fd->private_data;
 986         ssize_t                         retval;
 987         enum ep0_state                  state;
 988
 989         spin_lock_irq (&dev->lock);
 990
 991         /* report fd mode change before acting on it */
 992         if (dev->setup_abort) {
 993                 dev->setup_abort = 0;
 994                 retval = -EIDRM;
 995                 goto done;
 996         }
 997
 998         /* control DATA stage */
 999         if ((state = dev->state) == STATE_DEV_SETUP) {
1000
1001                 if (dev->setup_in) {            /* stall IN */
1002                         VDEBUG(dev, "ep0in stall\n");
1003                         (void) usb_ep_set_halt (dev->gadget->ep0);
1004                         retval = -EL2HLT;
1005                         dev->state = STATE_DEV_CONNECTED;
1006
1007                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
1008                         struct usb_ep           *ep = dev->gadget->ep0;
1009                         struct usb_request      *req = dev->req;
1010
1011                         if ((retval = setup_req (ep, req, 0)) == 0)
1012                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1013                         dev->state = STATE_DEV_CONNECTED;
1014
1015                         /* assume that was SET_CONFIGURATION */
1016                         if (dev->current_config) {
1017                                 unsigned power;
1018
1019                                 if (gadget_is_dualspeed(dev->gadget)
1020                                                 && (dev->gadget->speed
1021                                                         == USB_SPEED_HIGH))
1022                                         power = dev->hs_config->bMaxPower;
1023                                 else
1024                                         power = dev->config->bMaxPower;
1025                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1026                         }
1027
1028                 } else {                        /* collect OUT data */
1029                         if ((fd->f_flags & O_NONBLOCK) != 0
1030                                         && !dev->setup_out_ready) {
1031                                 retval = -EAGAIN;
1032                                 goto done;
1033                         }
1034                         spin_unlock_irq (&dev->lock);
1035                         retval = wait_event_interruptible (dev->wait,
1036                                         dev->setup_out_ready != 0);
1037
1038                         /* FIXME state could change from under us */
1039                         spin_lock_irq (&dev->lock);
1040                         if (retval)
1041                                 goto done;
1042
1043                         if (dev->state != STATE_DEV_SETUP) {
1044                                 retval = -ECANCELED;
1045                                 goto done;
1046                         }
1047                         dev->state = STATE_DEV_CONNECTED;
1048
1049                         if (dev->setup_out_error)
1050                                 retval = -EIO;
1051                         else {
1052                                 len = min (len, (size_t)dev->req->actual);
1053 // FIXME don't call this with the spinlock held ...
1054                                 if (copy_to_user (buf, dev->req->buf, len))
1055                                         retval = -EFAULT;
1056                                 else
1057                                         retval = len;
1058                                 clean_req (dev->gadget->ep0, dev->req);
1059                                 /* NOTE userspace can't yet choose to stall */
1060                         }
1061                 }
1062                 goto done;
1063         }
1064
1065         /* else normal: return event data */
1066         if (len < sizeof dev->event [0]) {
1067                 retval = -EINVAL;
1068                 goto done;
1069         }
1070         len -= len % sizeof (struct usb_gadgetfs_event);
1071         dev->usermode_setup = 1;
1072
1073 scan:
1074         /* return queued events right away */
1075         if (dev->ev_next != 0) {
1076                 unsigned                i, n;
1077
1078                 n = len / sizeof (struct usb_gadgetfs_event);
1079                 if (dev->ev_next < n)
1080                         n = dev->ev_next;
1081
1082                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1083                 for (i = 0; i < n; i++) {
1084                         if (dev->event [i].type == GADGETFS_SETUP) {
1085                                 dev->state = STATE_DEV_SETUP;
1086                                 n = i + 1;
1087                                 break;
1088                         }
1089                 }
1090                 spin_unlock_irq (&dev->lock);
1091                 len = n * sizeof (struct usb_gadgetfs_event);
1092                 if (copy_to_user (buf, &dev->event, len))
1093                         retval = -EFAULT;
1094                 else
1095                         retval = len;
1096                 if (len > 0) {
1097                         /* NOTE this doesn't guard against broken drivers;
1098                          * concurrent ep0 readers may lose events.
1099                          */
1100                         spin_lock_irq (&dev->lock);
1101                         if (dev->ev_next > n) {
1102                                 memmove(&dev->event[0], &dev->event[n],
1103                                         sizeof (struct usb_gadgetfs_event)
1104                                                 * (dev->ev_next - n));
1105                         }
1106                         dev->ev_next -= n;
1107                         spin_unlock_irq (&dev->lock);
1108                 }
1109                 return retval;
1110         }
1111         if (fd->f_flags & O_NONBLOCK) {
1112                 retval = -EAGAIN;
1113                 goto done;
1114         }
1115
1116         switch (state) {
1117         default:
1118                 DBG (dev, "fail %s, state %d\n", __func__, state);
1119                 retval = -ESRCH;
1120                 break;
1121         case STATE_DEV_UNCONNECTED:
1122         case STATE_DEV_CONNECTED:
1123                 spin_unlock_irq (&dev->lock);
1124                 DBG (dev, "%s wait\n", __func__);
1125
1126                 /* wait for events */
1127                 retval = wait_event_interruptible (dev->wait,
1128                                 dev->ev_next != 0);
1129                 if (retval < 0)
1130                         return retval;
1131                 spin_lock_irq (&dev->lock);
1132                 goto scan;
1133         }
1134
1135 done:
1136         spin_unlock_irq (&dev->lock);
1137         return retval;
1138 }
1139
1140 static struct usb_gadgetfs_event *
1141 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1142 {
1143         struct usb_gadgetfs_event       *event;
1144         unsigned                        i;
1145
1146         switch (type) {
1147         /* these events purge the queue */
1148         case GADGETFS_DISCONNECT:
1149                 if (dev->state == STATE_DEV_SETUP)
1150                         dev->setup_abort = 1;
1151                 // FALL THROUGH
1152         case GADGETFS_CONNECT:
1153                 dev->ev_next = 0;
1154                 break;
1155         case GADGETFS_SETUP:            /* previous request timed out */
1156         case GADGETFS_SUSPEND:          /* same effect */
1157                 /* these events can't be repeated */
1158                 for (i = 0; i != dev->ev_next; i++) {
1159                         if (dev->event [i].type != type)
1160                                 continue;
1161                         DBG(dev, "discard old event[%d] %d\n", i, type);
1162                         dev->ev_next--;
1163                         if (i == dev->ev_next)
1164                                 break;
1165                         /* indices start at zero, for simplicity */
1166                         memmove (&dev->event [i], &dev->event [i + 1],
1167                                 sizeof (struct usb_gadgetfs_event)
1168                                         * (dev->ev_next - i));
1169                 }
1170                 break;
1171         default:
1172                 BUG ();
1173         }
1174         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1175         event = &dev->event [dev->ev_next++];
1176         BUG_ON (dev->ev_next > N_EVENT);
1177         memset (event, 0, sizeof *event);
1178         event->type = type;
1179         return event;
1180 }
1181
1182 static ssize_t
1183 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1184 {
1185         struct dev_data         *dev = fd->private_data;
1186         ssize_t                 retval = -ESRCH;
1187
1188         spin_lock_irq (&dev->lock);
1189
1190         /* report fd mode change before acting on it */
1191         if (dev->setup_abort) {
1192                 dev->setup_abort = 0;
1193                 retval = -EIDRM;
1194
1195         /* data and/or status stage for control request */
1196         } else if (dev->state == STATE_DEV_SETUP) {
1197
1198                 /* IN DATA+STATUS caller makes len <= wLength */
1199                 if (dev->setup_in) {
1200                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1201                         if (retval == 0) {
1202                                 dev->state = STATE_DEV_CONNECTED;
1203                                 spin_unlock_irq (&dev->lock);
1204                                 if (copy_from_user (dev->req->buf, buf, len))
1205                                         retval = -EFAULT;
1206                                 else {
1207                                         if (len < dev->setup_wLength)
1208                                                 dev->req->zero = 1;
1209                                         retval = usb_ep_queue (
1210                                                 dev->gadget->ep0, dev->req,
1211                                                 GFP_KERNEL);
1212                                 }
1213                                 if (retval < 0) {
1214                                         spin_lock_irq (&dev->lock);
1215                                         clean_req (dev->gadget->ep0, dev->req);
1216                                         spin_unlock_irq (&dev->lock);
1217                                 } else
1218                                         retval = len;
1219
1220                                 return retval;
1221                         }
1222
1223                 /* can stall some OUT transfers */
1224                 } else if (dev->setup_can_stall) {
1225                         VDEBUG(dev, "ep0out stall\n");
1226                         (void) usb_ep_set_halt (dev->gadget->ep0);
1227                         retval = -EL2HLT;
1228                         dev->state = STATE_DEV_CONNECTED;
1229                 } else {
1230                         DBG(dev, "bogus ep0out stall!\n");
1231                 }
1232         } else
1233                 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1234
1235         spin_unlock_irq (&dev->lock);
1236         return retval;
1237 }
1238
1239 static int
1240 ep0_fasync (int f, struct file *fd, int on)
1241 {
1242         struct dev_data         *dev = fd->private_data;
1243         // caller must F_SETOWN before signal delivery happens
1244         VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1245         return fasync_helper (f, fd, on, &dev->fasync);
1246 }
1247
1248 static struct usb_gadget_driver gadgetfs_driver;
1249
1250 static int
1251 dev_release (struct inode *inode, struct file *fd)
1252 {
1253         struct dev_data         *dev = fd->private_data;
1254
1255         /* closing ep0 === shutdown all */
1256
1257         usb_gadget_unregister_driver (&gadgetfs_driver);
1258
1259         /* at this point "good" hardware has disconnected the
1260          * device from USB; the host won't see it any more.
1261          * alternatively, all host requests will time out.
1262          */
1263
1264         kfree (dev->buf);
1265         dev->buf = NULL;
1266
1267         /* other endpoints were all decoupled from this device */
1268         spin_lock_irq(&dev->lock);
1269         dev->state = STATE_DEV_DISABLED;
1270         spin_unlock_irq(&dev->lock);
1271
1272         put_dev (dev);
1273         return 0;
1274 }
1275
1276 static unsigned int
1277 ep0_poll (struct file *fd, poll_table *wait)
1278 {
1279        struct dev_data         *dev = fd->private_data;
1280        int                     mask = 0;
1281
1282        poll_wait(fd, &dev->wait, wait);
1283
1284        spin_lock_irq (&dev->lock);
1285
1286        /* report fd mode change before acting on it */
1287        if (dev->setup_abort) {
1288                dev->setup_abort = 0;
1289                mask = POLLHUP;
1290                goto out;
1291        }
1292
1293        if (dev->state == STATE_DEV_SETUP) {
1294                if (dev->setup_in || dev->setup_can_stall)
1295                        mask = POLLOUT;
1296        } else {
1297                if (dev->ev_next != 0)
1298                        mask = POLLIN;
1299        }
1300 out:
1301        spin_unlock_irq(&dev->lock);
1302        return mask;
1303 }
1304
1305 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1306 {
1307         struct dev_data         *dev = fd->private_data;
1308         struct usb_gadget       *gadget = dev->gadget;
1309         long ret = -ENOTTY;
1310
1311         if (gadget->ops->ioctl)
1312                 ret = gadget->ops->ioctl (gadget, code, value);
1313
1314         return ret;
1315 }
1316
1317 /* used after device configuration */
1318 static const struct file_operations ep0_io_operations = {
1319         .owner =        THIS_MODULE,
1320         .llseek =       no_llseek,
1321
1322         .read =         ep0_read,
1323         .write =        ep0_write,
1324         .fasync =       ep0_fasync,
1325         .poll =         ep0_poll,
1326         .unlocked_ioctl =       dev_ioctl,
1327         .release =      dev_release,
1328 };
1329
1330 /*----------------------------------------------------------------------*/
1331
1332 /* The in-kernel gadget driver handles most ep0 issues, in particular
1333  * enumerating the single configuration (as provided from user space).
1334  *
1335  * Unrecognized ep0 requests may be handled in user space.
1336  */
1337
1338 static void make_qualifier (struct dev_data *dev)
1339 {
1340         struct usb_qualifier_descriptor         qual;
1341         struct usb_device_descriptor            *desc;
1342
1343         qual.bLength = sizeof qual;
1344         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1345         qual.bcdUSB = cpu_to_le16 (0x0200);
1346
1347         desc = dev->dev;
1348         qual.bDeviceClass = desc->bDeviceClass;
1349         qual.bDeviceSubClass = desc->bDeviceSubClass;
1350         qual.bDeviceProtocol = desc->bDeviceProtocol;
1351
1352         /* assumes ep0 uses the same value for both speeds ... */
1353         qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1354
1355         qual.bNumConfigurations = 1;
1356         qual.bRESERVED = 0;
1357
1358         memcpy (dev->rbuf, &qual, sizeof qual);
1359 }
1360
1361 static int
1362 config_buf (struct dev_data *dev, u8 type, unsigned index)
1363 {
1364         int             len;
1365         int             hs = 0;
1366
1367         /* only one configuration */
1368         if (index > 0)
1369                 return -EINVAL;
1370
1371         if (gadget_is_dualspeed(dev->gadget)) {
1372                 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1373                 if (type == USB_DT_OTHER_SPEED_CONFIG)
1374                         hs = !hs;
1375         }
1376         if (hs) {
1377                 dev->req->buf = dev->hs_config;
1378                 len = le16_to_cpu(dev->hs_config->wTotalLength);
1379         } else {
1380                 dev->req->buf = dev->config;
1381                 len = le16_to_cpu(dev->config->wTotalLength);
1382         }
1383         ((u8 *)dev->req->buf) [1] = type;
1384         return len;
1385 }
1386
1387 static int
1388 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1389 {
1390         struct dev_data                 *dev = get_gadget_data (gadget);
1391         struct usb_request              *req = dev->req;
1392         int                             value = -EOPNOTSUPP;
1393         struct usb_gadgetfs_event       *event;
1394         u16                             w_value = le16_to_cpu(ctrl->wValue);
1395         u16                             w_length = le16_to_cpu(ctrl->wLength);
1396
1397         spin_lock (&dev->lock);
1398         dev->setup_abort = 0;
1399         if (dev->state == STATE_DEV_UNCONNECTED) {
1400                 if (gadget_is_dualspeed(gadget)
1401                                 && gadget->speed == USB_SPEED_HIGH
1402                                 && dev->hs_config == NULL) {
1403                         spin_unlock(&dev->lock);
1404                         ERROR (dev, "no high speed config??\n");
1405                         return -EINVAL;
1406                 }
1407
1408                 dev->state = STATE_DEV_CONNECTED;
1409
1410                 INFO (dev, "connected\n");
1411                 event = next_event (dev, GADGETFS_CONNECT);
1412                 event->u.speed = gadget->speed;
1413                 ep0_readable (dev);
1414
1415         /* host may have given up waiting for response.  we can miss control
1416          * requests handled lower down (device/endpoint status and features);
1417          * then ep0_{read,write} will report the wrong status. controller
1418          * driver will have aborted pending i/o.
1419          */
1420         } else if (dev->state == STATE_DEV_SETUP)
1421                 dev->setup_abort = 1;
1422
1423         req->buf = dev->rbuf;
1424         req->context = NULL;
1425         value = -EOPNOTSUPP;
1426         switch (ctrl->bRequest) {
1427
1428         case USB_REQ_GET_DESCRIPTOR:
1429                 if (ctrl->bRequestType != USB_DIR_IN)
1430                         goto unrecognized;
1431                 switch (w_value >> 8) {
1432
1433                 case USB_DT_DEVICE:
1434                         value = min (w_length, (u16) sizeof *dev->dev);
1435                         dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1436                         req->buf = dev->dev;
1437                         break;
1438                 case USB_DT_DEVICE_QUALIFIER:
1439                         if (!dev->hs_config)
1440                                 break;
1441                         value = min (w_length, (u16)
1442                                 sizeof (struct usb_qualifier_descriptor));
1443                         make_qualifier (dev);
1444                         break;
1445                 case USB_DT_OTHER_SPEED_CONFIG:
1446                         // FALLTHROUGH
1447                 case USB_DT_CONFIG:
1448                         value = config_buf (dev,
1449                                         w_value >> 8,
1450                                         w_value & 0xff);
1451                         if (value >= 0)
1452                                 value = min (w_length, (u16) value);
1453                         break;
1454                 case USB_DT_STRING:
1455                         goto unrecognized;
1456
1457                 default:                // all others are errors
1458                         break;
1459                 }
1460                 break;
1461
1462         /* currently one config, two speeds */
1463         case USB_REQ_SET_CONFIGURATION:
1464                 if (ctrl->bRequestType != 0)
1465                         goto unrecognized;
1466                 if (0 == (u8) w_value) {
1467                         value = 0;
1468                         dev->current_config = 0;
1469                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1470                         // user mode expected to disable endpoints
1471                 } else {
1472                         u8      config, power;
1473
1474                         if (gadget_is_dualspeed(gadget)
1475                                         && gadget->speed == USB_SPEED_HIGH) {
1476                                 config = dev->hs_config->bConfigurationValue;
1477                                 power = dev->hs_config->bMaxPower;
1478                         } else {
1479                                 config = dev->config->bConfigurationValue;
1480                                 power = dev->config->bMaxPower;
1481                         }
1482
1483                         if (config == (u8) w_value) {
1484                                 value = 0;
1485                                 dev->current_config = config;
1486                                 usb_gadget_vbus_draw(gadget, 2 * power);
1487                         }
1488                 }
1489
1490                 /* report SET_CONFIGURATION like any other control request,
1491                  * except that usermode may not stall this.  the next
1492                  * request mustn't be allowed start until this finishes:
1493                  * endpoints and threads set up, etc.
1494                  *
1495                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1496                  * has bad/racey automagic that prevents synchronizing here.
1497                  * even kernel mode drivers often miss them.
1498                  */
1499                 if (value == 0) {
1500                         INFO (dev, "configuration #%d\n", dev->current_config);
1501                         usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
1502                         if (dev->usermode_setup) {
1503                                 dev->setup_can_stall = 0;
1504                                 goto delegate;
1505                         }
1506                 }
1507                 break;
1508
1509 #ifndef CONFIG_USB_PXA25X
1510         /* PXA automagically handles this request too */
1511         case USB_REQ_GET_CONFIGURATION:
1512                 if (ctrl->bRequestType != 0x80)
1513                         goto unrecognized;
1514                 *(u8 *)req->buf = dev->current_config;
1515                 value = min (w_length, (u16) 1);
1516                 break;
1517 #endif
1518
1519         default:
1520 unrecognized:
1521                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1522                         dev->usermode_setup ? "delegate" : "fail",
1523                         ctrl->bRequestType, ctrl->bRequest,
1524                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1525
1526                 /* if there's an ep0 reader, don't stall */
1527                 if (dev->usermode_setup) {
1528                         dev->setup_can_stall = 1;
1529 delegate:
1530                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1531                                                 ? 1 : 0;
1532                         dev->setup_wLength = w_length;
1533                         dev->setup_out_ready = 0;
1534                         dev->setup_out_error = 0;
1535                         value = 0;
1536
1537                         /* read DATA stage for OUT right away */
1538                         if (unlikely (!dev->setup_in && w_length)) {
1539                                 value = setup_req (gadget->ep0, dev->req,
1540                                                         w_length);
1541                                 if (value < 0)
1542                                         break;
1543                                 value = usb_ep_queue (gadget->ep0, dev->req,
1544                                                         GFP_ATOMIC);
1545                                 if (value < 0) {
1546                                         clean_req (gadget->ep0, dev->req);
1547                                         break;
1548                                 }
1549
1550                                 /* we can't currently stall these */
1551                                 dev->setup_can_stall = 0;
1552                         }
1553
1554                         /* state changes when reader collects event */
1555                         event = next_event (dev, GADGETFS_SETUP);
1556                         event->u.setup = *ctrl;
1557                         ep0_readable (dev);
1558                         spin_unlock (&dev->lock);
1559                         return 0;
1560                 }
1561         }
1562
1563         /* proceed with data transfer and status phases? */
1564         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1565                 req->length = value;
1566                 req->zero = value < w_length;
1567                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1568                 if (value < 0) {
1569                         DBG (dev, "ep_queue --> %d\n", value);
1570                         req->status = 0;
1571                 }
1572         }
1573
1574         /* device stalls when value < 0 */
1575         spin_unlock (&dev->lock);
1576         return value;
1577 }
1578
1579 static void destroy_ep_files (struct dev_data *dev)
1580 {
1581         DBG (dev, "%s %d\n", __func__, dev->state);
1582
1583         /* dev->state must prevent interference */
1584         spin_lock_irq (&dev->lock);
1585         while (!list_empty(&dev->epfiles)) {
1586                 struct ep_data  *ep;
1587                 struct inode    *parent;
1588                 struct dentry   *dentry;
1589
1590                 /* break link to FS */
1591                 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1592                 list_del_init (&ep->epfiles);
1593                 dentry = ep->dentry;
1594                 ep->dentry = NULL;
1595                 parent = dentry->d_parent->d_inode;
1596
1597                 /* break link to controller */
1598                 if (ep->state == STATE_EP_ENABLED)
1599                         (void) usb_ep_disable (ep->ep);
1600                 ep->state = STATE_EP_UNBOUND;
1601                 usb_ep_free_request (ep->ep, ep->req);
1602                 ep->ep = NULL;
1603                 wake_up (&ep->wait);
1604                 put_ep (ep);
1605
1606                 spin_unlock_irq (&dev->lock);
1607
1608                 /* break link to dcache */
1609                 mutex_lock (&parent->i_mutex);
1610                 d_delete (dentry);
1611                 dput (dentry);
1612                 mutex_unlock (&parent->i_mutex);
1613
1614                 spin_lock_irq (&dev->lock);
1615         }
1616         spin_unlock_irq (&dev->lock);
1617 }
1618
1619
1620 static struct dentry *
1621 gadgetfs_create_file (struct super_block *sb, char const *name,
1622                 void *data, const struct file_operations *fops);
1623
1624 static int activate_ep_files (struct dev_data *dev)
1625 {
1626         struct usb_ep   *ep;
1627         struct ep_data  *data;
1628
1629         gadget_for_each_ep (ep, dev->gadget) {
1630
1631                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1632                 if (!data)
1633                         goto enomem0;
1634                 data->state = STATE_EP_DISABLED;
1635                 mutex_init(&data->lock);
1636                 init_waitqueue_head (&data->wait);
1637
1638                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1639                 atomic_set (&data->count, 1);
1640                 data->dev = dev;
1641                 get_dev (dev);
1642
1643                 data->ep = ep;
1644                 ep->driver_data = data;
1645
1646                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1647                 if (!data->req)
1648                         goto enomem1;
1649
1650                 data->dentry = gadgetfs_create_file (dev->sb, data->name,
1651                                 data, &ep_config_operations);
1652                 if (!data->dentry)
1653                         goto enomem2;
1654                 list_add_tail (&data->epfiles, &dev->epfiles);
1655         }
1656         return 0;
1657
1658 enomem2:
1659         usb_ep_free_request (ep, data->req);
1660 enomem1:
1661         put_dev (dev);
1662         kfree (data);
1663 enomem0:
1664         DBG (dev, "%s enomem\n", __func__);
1665         destroy_ep_files (dev);
1666         return -ENOMEM;
1667 }
1668
1669 static void
1670 gadgetfs_unbind (struct usb_gadget *gadget)
1671 {
1672         struct dev_data         *dev = get_gadget_data (gadget);
1673
1674         DBG (dev, "%s\n", __func__);
1675
1676         spin_lock_irq (&dev->lock);
1677         dev->state = STATE_DEV_UNBOUND;
1678         spin_unlock_irq (&dev->lock);
1679
1680         destroy_ep_files (dev);
1681         gadget->ep0->driver_data = NULL;
1682         set_gadget_data (gadget, NULL);
1683
1684         /* we've already been disconnected ... no i/o is active */
1685         if (dev->req)
1686                 usb_ep_free_request (gadget->ep0, dev->req);
1687         DBG (dev, "%s done\n", __func__);
1688         put_dev (dev);
1689 }
1690
1691 static struct dev_data          *the_device;
1692
1693 static int gadgetfs_bind(struct usb_gadget *gadget,
1694                 struct usb_gadget_driver *driver)
1695 {
1696         struct dev_data         *dev = the_device;
1697
1698         if (!dev)
1699                 return -ESRCH;
1700         if (0 != strcmp (CHIP, gadget->name)) {
1701                 pr_err("%s expected %s controller not %s\n",
1702                         shortname, CHIP, gadget->name);
1703                 return -ENODEV;
1704         }
1705
1706         set_gadget_data (gadget, dev);
1707         dev->gadget = gadget;
1708         gadget->ep0->driver_data = dev;
1709
1710         /* preallocate control response and buffer */
1711         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1712         if (!dev->req)
1713                 goto enomem;
1714         dev->req->context = NULL;
1715         dev->req->complete = epio_complete;
1716
1717         if (activate_ep_files (dev) < 0)
1718                 goto enomem;
1719
1720         INFO (dev, "bound to %s driver\n", gadget->name);
1721         spin_lock_irq(&dev->lock);
1722         dev->state = STATE_DEV_UNCONNECTED;
1723         spin_unlock_irq(&dev->lock);
1724         get_dev (dev);
1725         return 0;
1726
1727 enomem:
1728         gadgetfs_unbind (gadget);
1729         return -ENOMEM;
1730 }
1731
1732 static void
1733 gadgetfs_disconnect (struct usb_gadget *gadget)
1734 {
1735         struct dev_data         *dev = get_gadget_data (gadget);
1736         unsigned long           flags;
1737
1738         spin_lock_irqsave (&dev->lock, flags);
1739         if (dev->state == STATE_DEV_UNCONNECTED)
1740                 goto exit;
1741         dev->state = STATE_DEV_UNCONNECTED;
1742
1743         INFO (dev, "disconnected\n");
1744         next_event (dev, GADGETFS_DISCONNECT);
1745         ep0_readable (dev);
1746 exit:
1747         spin_unlock_irqrestore (&dev->lock, flags);
1748 }
1749
1750 static void
1751 gadgetfs_suspend (struct usb_gadget *gadget)
1752 {
1753         struct dev_data         *dev = get_gadget_data (gadget);
1754
1755         INFO (dev, "suspended from state %d\n", dev->state);
1756         spin_lock (&dev->lock);
1757         switch (dev->state) {
1758         case STATE_DEV_SETUP:           // VERY odd... host died??
1759         case STATE_DEV_CONNECTED:
1760         case STATE_DEV_UNCONNECTED:
1761                 next_event (dev, GADGETFS_SUSPEND);
1762                 ep0_readable (dev);
1763                 /* FALLTHROUGH */
1764         default:
1765                 break;
1766         }
1767         spin_unlock (&dev->lock);
1768 }
1769
1770 static struct usb_gadget_driver gadgetfs_driver = {
1771         .function       = (char *) driver_desc,
1772         .bind           = gadgetfs_bind,
1773         .unbind         = gadgetfs_unbind,
1774         .setup          = gadgetfs_setup,
1775         .disconnect     = gadgetfs_disconnect,
1776         .suspend        = gadgetfs_suspend,
1777
1778         .driver = {
1779                 .name           = (char *) shortname,
1780         },
1781 };
1782
1783 /*----------------------------------------------------------------------*/
1784
1785 static void gadgetfs_nop(struct usb_gadget *arg) { }
1786
1787 static int gadgetfs_probe(struct usb_gadget *gadget,
1788                 struct usb_gadget_driver *driver)
1789 {
1790         CHIP = gadget->name;
1791         return -EISNAM;
1792 }
1793
1794 static struct usb_gadget_driver probe_driver = {
1795         .max_speed      = USB_SPEED_HIGH,
1796         .bind           = gadgetfs_probe,
1797         .unbind         = gadgetfs_nop,
1798         .setup          = (void *)gadgetfs_nop,
1799         .disconnect     = gadgetfs_nop,
1800         .driver = {
1801                 .name           = "nop",
1802         },
1803 };
1804
1805
1806 /* DEVICE INITIALIZATION
1807  *
1808  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1809  *     status = write (fd, descriptors, sizeof descriptors)
1810  *
1811  * That write establishes the device configuration, so the kernel can
1812  * bind to the controller ... guaranteeing it can handle enumeration
1813  * at all necessary speeds.  Descriptor order is:
1814  *
1815  * . message tag (u32, host order) ... for now, must be zero; it
1816  *      would change to support features like multi-config devices
1817  * . full/low speed config ... all wTotalLength bytes (with interface,
1818  *      class, altsetting, endpoint, and other descriptors)
1819  * . high speed config ... all descriptors, for high speed operation;
1820  *      this one's optional except for high-speed hardware
1821  * . device descriptor
1822  *
1823  * Endpoints are not yet enabled. Drivers must wait until device
1824  * configuration and interface altsetting changes create
1825  * the need to configure (or unconfigure) them.
1826  *
1827  * After initialization, the device stays active for as long as that
1828  * $CHIP file is open.  Events must then be read from that descriptor,
1829  * such as configuration notifications.
1830  */
1831
1832 static int is_valid_config (struct usb_config_descriptor *config)
1833 {
1834         return config->bDescriptorType == USB_DT_CONFIG
1835                 && config->bLength == USB_DT_CONFIG_SIZE
1836                 && config->bConfigurationValue != 0
1837                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1838                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1839         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1840         /* FIXME check lengths: walk to end */
1841 }
1842
1843 static ssize_t
1844 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1845 {
1846         struct dev_data         *dev = fd->private_data;
1847         ssize_t                 value = len, length = len;
1848         unsigned                total;
1849         u32                     tag;
1850         char                    *kbuf;
1851
1852         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1853                 return -EINVAL;
1854
1855         /* we might need to change message format someday */
1856         if (copy_from_user (&tag, buf, 4))
1857                 return -EFAULT;
1858         if (tag != 0)
1859                 return -EINVAL;
1860         buf += 4;
1861         length -= 4;
1862
1863         kbuf = memdup_user(buf, length);
1864         if (IS_ERR(kbuf))
1865                 return PTR_ERR(kbuf);
1866
1867         spin_lock_irq (&dev->lock);
1868         value = -EINVAL;
1869         if (dev->buf)
1870                 goto fail;
1871         dev->buf = kbuf;
1872
1873         /* full or low speed config */
1874         dev->config = (void *) kbuf;
1875         total = le16_to_cpu(dev->config->wTotalLength);
1876         if (!is_valid_config (dev->config) || total >= length)
1877                 goto fail;
1878         kbuf += total;
1879         length -= total;
1880
1881         /* optional high speed config */
1882         if (kbuf [1] == USB_DT_CONFIG) {
1883                 dev->hs_config = (void *) kbuf;
1884                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1885                 if (!is_valid_config (dev->hs_config) || total >= length)
1886                         goto fail;
1887                 kbuf += total;
1888                 length -= total;
1889         }
1890
1891         /* could support multiple configs, using another encoding! */
1892
1893         /* device descriptor (tweaked for paranoia) */
1894         if (length != USB_DT_DEVICE_SIZE)
1895                 goto fail;
1896         dev->dev = (void *)kbuf;
1897         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1898                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1899                         || dev->dev->bNumConfigurations != 1)
1900                 goto fail;
1901         dev->dev->bNumConfigurations = 1;
1902         dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1903
1904         /* triggers gadgetfs_bind(); then we can enumerate. */
1905         spin_unlock_irq (&dev->lock);
1906         if (dev->hs_config)
1907                 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1908         else
1909                 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1910
1911         value = usb_gadget_probe_driver(&gadgetfs_driver);
1912         if (value != 0) {
1913                 kfree (dev->buf);
1914                 dev->buf = NULL;
1915         } else {
1916                 /* at this point "good" hardware has for the first time
1917                  * let the USB the host see us.  alternatively, if users
1918                  * unplug/replug that will clear all the error state.
1919                  *
1920                  * note:  everything running before here was guaranteed
1921                  * to choke driver model style diagnostics.  from here
1922                  * on, they can work ... except in cleanup paths that
1923                  * kick in after the ep0 descriptor is closed.
1924                  */
1925                 fd->f_op = &ep0_io_operations;
1926                 value = len;
1927         }
1928         return value;
1929
1930 fail:
1931         spin_unlock_irq (&dev->lock);
1932         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1933         kfree (dev->buf);
1934         dev->buf = NULL;
1935         return value;
1936 }
1937
1938 static int
1939 dev_open (struct inode *inode, struct file *fd)
1940 {
1941         struct dev_data         *dev = inode->i_private;
1942         int                     value = -EBUSY;
1943
1944         spin_lock_irq(&dev->lock);
1945         if (dev->state == STATE_DEV_DISABLED) {
1946                 dev->ev_next = 0;
1947                 dev->state = STATE_DEV_OPENED;
1948                 fd->private_data = dev;
1949                 get_dev (dev);
1950                 value = 0;
1951         }
1952         spin_unlock_irq(&dev->lock);
1953         return value;
1954 }
1955
1956 static const struct file_operations dev_init_operations = {
1957         .llseek =       no_llseek,
1958
1959         .open =         dev_open,
1960         .write =        dev_config,
1961         .fasync =       ep0_fasync,
1962         .unlocked_ioctl = dev_ioctl,
1963         .release =      dev_release,
1964 };
1965
1966 /*----------------------------------------------------------------------*/
1967
1968 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1969  *
1970  * Mounting the filesystem creates a controller file, used first for
1971  * device configuration then later for event monitoring.
1972  */
1973
1974
1975 /* FIXME PAM etc could set this security policy without mount options
1976  * if epfiles inherited ownership and permissons from ep0 ...
1977  */
1978
1979 static unsigned default_uid;
1980 static unsigned default_gid;
1981 static unsigned default_perm = S_IRUSR | S_IWUSR;
1982
1983 module_param (default_uid, uint, 0644);
1984 module_param (default_gid, uint, 0644);
1985 module_param (default_perm, uint, 0644);
1986
1987
1988 static struct inode *
1989 gadgetfs_make_inode (struct super_block *sb,
1990                 void *data, const struct file_operations *fops,
1991                 int mode)
1992 {
1993         struct inode *inode = new_inode (sb);
1994
1995         if (inode) {
1996                 inode->i_ino = get_next_ino();
1997                 inode->i_mode = mode;
1998                 inode->i_uid = make_kuid(&init_user_ns, default_uid);
1999                 inode->i_gid = make_kgid(&init_user_ns, default_gid);
2000                 inode->i_atime = inode->i_mtime = inode->i_ctime
2001                                 = CURRENT_TIME;
2002                 inode->i_private = data;
2003                 inode->i_fop = fops;
2004         }
2005         return inode;
2006 }
2007
2008 /* creates in fs root directory, so non-renamable and non-linkable.
2009  * so inode and dentry are paired, until device reconfig.
2010  */
2011 static struct dentry *
2012 gadgetfs_create_file (struct super_block *sb, char const *name,
2013                 void *data, const struct file_operations *fops)
2014 {
2015         struct dentry   *dentry;
2016         struct inode    *inode;
2017
2018         dentry = d_alloc_name(sb->s_root, name);
2019         if (!dentry)
2020                 return NULL;
2021
2022         inode = gadgetfs_make_inode (sb, data, fops,
2023                         S_IFREG | (default_perm & S_IRWXUGO));
2024         if (!inode) {
2025                 dput(dentry);
2026                 return NULL;
2027         }
2028         d_add (dentry, inode);
2029         return dentry;
2030 }
2031
2032 static const struct super_operations gadget_fs_operations = {
2033         .statfs =       simple_statfs,
2034         .drop_inode =   generic_delete_inode,
2035 };
2036
2037 static int
2038 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2039 {
2040         struct inode    *inode;
2041         struct dev_data *dev;
2042
2043         if (the_device)
2044                 return -ESRCH;
2045
2046         /* fake probe to determine $CHIP */
2047         CHIP = NULL;
2048         usb_gadget_probe_driver(&probe_driver);
2049         if (!CHIP)
2050                 return -ENODEV;
2051
2052         /* superblock */
2053         sb->s_blocksize = PAGE_CACHE_SIZE;
2054         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2055         sb->s_magic = GADGETFS_MAGIC;
2056         sb->s_op = &gadget_fs_operations;
2057         sb->s_time_gran = 1;
2058
2059         /* root inode */
2060         inode = gadgetfs_make_inode (sb,
2061                         NULL, &simple_dir_operations,
2062                         S_IFDIR | S_IRUGO | S_IXUGO);
2063         if (!inode)
2064                 goto Enomem;
2065         inode->i_op = &simple_dir_inode_operations;
2066         if (!(sb->s_root = d_make_root (inode)))
2067                 goto Enomem;
2068
2069         /* the ep0 file is named after the controller we expect;
2070          * user mode code can use it for sanity checks, like we do.
2071          */
2072         dev = dev_new ();
2073         if (!dev)
2074                 goto Enomem;
2075
2076         dev->sb = sb;
2077         dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &dev_init_operations);
2078         if (!dev->dentry) {
2079                 put_dev(dev);
2080                 goto Enomem;
2081         }
2082
2083         /* other endpoint files are available after hardware setup,
2084          * from binding to a controller.
2085          */
2086         the_device = dev;
2087         return 0;
2088
2089 Enomem:
2090         return -ENOMEM;
2091 }
2092
2093 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2094 static struct dentry *
2095 gadgetfs_mount (struct file_system_type *t, int flags,
2096                 const char *path, void *opts)
2097 {
2098         return mount_single (t, flags, opts, gadgetfs_fill_super);
2099 }
2100
2101 static void
2102 gadgetfs_kill_sb (struct super_block *sb)
2103 {
2104         kill_litter_super (sb);
2105         if (the_device) {
2106                 put_dev (the_device);
2107                 the_device = NULL;
2108         }
2109 }
2110
2111 /*----------------------------------------------------------------------*/
2112
2113 static struct file_system_type gadgetfs_type = {
2114         .owner          = THIS_MODULE,
2115         .name           = shortname,
2116         .mount          = gadgetfs_mount,
2117         .kill_sb        = gadgetfs_kill_sb,
2118 };
2119 MODULE_ALIAS_FS("gadgetfs");
2120
2121 /*----------------------------------------------------------------------*/
2122
2123 static int __init init (void)
2124 {
2125         int status;
2126
2127         status = register_filesystem (&gadgetfs_type);
2128         if (status == 0)
2129                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2130                         shortname, driver_desc);
2131         return status;
2132 }
2133 module_init (init);
2134
2135 static void __exit cleanup (void)
2136 {
2137         pr_debug ("unregister %s\n", shortname);
2138         unregister_filesystem (&gadgetfs_type);
2139 }
2140 module_exit (cleanup);
2141