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   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  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22
  23 // #define      DEBUG                   /* data to help fault diagnosis */
  24 // #define      VERBOSE         /* extra debug messages (success too) */
  25
  26 #include <linux/init.h>
  27 #include <linux/module.h>
  28 #include <linux/fs.h>
  29 #include <linux/pagemap.h>
  30 #include <linux/uts.h>
  31 #include <linux/wait.h>
  32 #include <linux/compiler.h>
  33 #include <asm/uaccess.h>
  34 #include <linux/slab.h>
  35
  36 #include <linux/device.h>
  37 #include <linux/moduleparam.h>
  38
  39 #include <linux/usb_gadgetfs.h>
  40 #include <linux/usb_gadget.h>
  41
  42
  43 /*
  44  * The gadgetfs API maps each endpoint to a file descriptor so that you
  45  * can use standard synchronous read/write calls for I/O.  There's some
  46  * O_NONBLOCK and O_ASYNC/FASYNC style i/o support.  Example usermode
  47  * drivers show how this works in practice.  You can also use AIO to
  48  * eliminate I/O gaps between requests, to help when streaming data.
  49  *
  50  * Key parts that must be USB-specific are protocols defining how the
  51  * read/write operations relate to the hardware state machines.  There
  52  * are two types of files.  One type is for the device, implementing ep0.
  53  * The other type is for each IN or OUT endpoint.  In both cases, the
  54  * user mode driver must configure the hardware before using it.
  55  *
  56  * - First, dev_config() is called when /dev/gadget/$CHIP is configured
  57  *   (by writing configuration and device descriptors).  Afterwards it
  58  *   may serve as a source of device events, used to handle all control
  59  *   requests other than basic enumeration.
  60  *
  61  * - Then either immediately, or after a SET_CONFIGURATION control request,
  62  *   ep_config() is called when each /dev/gadget/ep* file is configured
  63  *   (by writing endpoint descriptors).  Afterwards these files are used
  64  *   to write() IN data or to read() OUT data.  To halt the endpoint, a
  65  *   "wrong direction" request is issued (like reading an IN endpoint).
  66  *
  67  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
  68  * not possible on all hardware.  For example, precise fault handling with
  69  * respect to data left in endpoint fifos after aborted operations; or
  70  * selective clearing of endpoint halts, to implement SET_INTERFACE.
  71  */
  72
  73 #define DRIVER_DESC     "USB Gadget filesystem"
  74 #define DRIVER_VERSION  "24 Aug 2004"
  75
  76 static const char driver_desc [] = DRIVER_DESC;
  77 static const char shortname [] = "gadgetfs";
  78
  79 MODULE_DESCRIPTION (DRIVER_DESC);
  80 MODULE_AUTHOR ("David Brownell");
  81 MODULE_LICENSE ("GPL");
  82
  83
  84 /*----------------------------------------------------------------------*/
  85
  86 #define GADGETFS_MAGIC          0xaee71ee7
  87 #define DMA_ADDR_INVALID        (~(dma_addr_t)0)
  88
  89 /* /dev/gadget/$CHIP represents ep0 and the whole device */
  90 enum ep0_state {
  91         /* DISBLED is the initial state.
  92          */
  93         STATE_DEV_DISABLED = 0,
  94
  95         /* Only one open() of /dev/gadget/$CHIP; only one file tracks
  96          * ep0/device i/o modes and binding to the controller.  Driver
  97          * must always write descriptors to initialize the device, then
  98          * the device becomes UNCONNECTED until enumeration.
  99          */
 100         STATE_OPENED,
 101
 102         /* From then on, ep0 fd is in either of two basic modes:
 103          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
 104          * - SETUP: read/write will transfer control data and succeed;
 105          *   or if "wrong direction", performs protocol stall
 106          */
 107         STATE_UNCONNECTED,
 108         STATE_CONNECTED,
 109         STATE_SETUP,
 110
 111         /* UNBOUND means the driver closed ep0, so the device won't be
 112          * accessible again (DEV_DISABLED) until all fds are closed.
 113          */
 114         STATE_DEV_UNBOUND,
 115 };
 116
 117 /* enough for the whole queue: most events invalidate others */
 118 #define N_EVENT                 5
 119
 120 struct dev_data {
 121         spinlock_t                      lock;
 122         atomic_t                        count;
 123         enum ep0_state                  state;
 124         struct usb_gadgetfs_event       event [N_EVENT];
 125         unsigned                        ev_next;
 126         struct fasync_struct            *fasync;
 127         u8                              current_config;
 128
 129         /* drivers reading ep0 MUST handle control requests (SETUP)
 130          * reported that way; else the host will time out.
 131          */
 132         unsigned                        usermode_setup : 1,
 133                                         setup_in : 1,
 134                                         setup_can_stall : 1,
 135                                         setup_out_ready : 1,
 136                                         setup_out_error : 1,
 137                                         setup_abort : 1;
 138
 139         /* the rest is basically write-once */
 140         struct usb_config_descriptor    *config, *hs_config;
 141         struct usb_device_descriptor    *dev;
 142         struct usb_request              *req;
 143         struct usb_gadget               *gadget;
 144         struct list_head                epfiles;
 145         void                            *buf;
 146         wait_queue_head_t               wait;
 147         struct super_block              *sb;
 148         struct dentry                   *dentry;
 149
 150         /* except this scratch i/o buffer for ep0 */
 151         u8                              rbuf [256];
 152 };
 153
 154 static inline void get_dev (struct dev_data *data)
 155 {
 156         atomic_inc (&data->count);
 157 }
 158
 159 static void put_dev (struct dev_data *data)
 160 {
 161         if (likely (!atomic_dec_and_test (&data->count)))
 162                 return;
 163         /* needs no more cleanup */
 164         BUG_ON (waitqueue_active (&data->wait));
 165         kfree (data);
 166 }
 167
 168 static struct dev_data *dev_new (void)
 169 {
 170         struct dev_data         *dev;
 171
 172         dev = kmalloc (sizeof *dev, GFP_KERNEL);
 173         if (!dev)
 174                 return NULL;
 175         memset (dev, 0, sizeof *dev);
 176         dev->state = STATE_DEV_DISABLED;
 177         atomic_set (&dev->count, 1);
 178         spin_lock_init (&dev->lock);
 179         INIT_LIST_HEAD (&dev->epfiles);
 180         init_waitqueue_head (&dev->wait);
 181         return dev;
 182 }
 183
 184 /*----------------------------------------------------------------------*/
 185
 186 /* other /dev/gadget/$ENDPOINT files represent endpoints */
 187 enum ep_state {
 188         STATE_EP_DISABLED = 0,
 189         STATE_EP_READY,
 190         STATE_EP_DEFER_ENABLE,
 191         STATE_EP_ENABLED,
 192         STATE_EP_UNBOUND,
 193 };
 194
 195 struct ep_data {
 196         struct semaphore                lock;
 197         enum ep_state                   state;
 198         atomic_t                        count;
 199         struct dev_data                 *dev;
 200         /* must hold dev->lock before accessing ep or req */
 201         struct usb_ep                   *ep;
 202         struct usb_request              *req;
 203         ssize_t                         status;
 204         char                            name [16];
 205         struct usb_endpoint_descriptor  desc, hs_desc;
 206         struct list_head                epfiles;
 207         wait_queue_head_t               wait;
 208         struct dentry                   *dentry;
 209         struct inode                    *inode;
 210 };
 211
 212 static inline void get_ep (struct ep_data *data)
 213 {
 214         atomic_inc (&data->count);
 215 }
 216
 217 static void put_ep (struct ep_data *data)
 218 {
 219         if (likely (!atomic_dec_and_test (&data->count)))
 220                 return;
 221         put_dev (data->dev);
 222         /* needs no more cleanup */
 223         BUG_ON (!list_empty (&data->epfiles));
 224         BUG_ON (waitqueue_active (&data->wait));
 225         BUG_ON (down_trylock (&data->lock) != 0);
 226         kfree (data);
 227 }
 228
 229 /*----------------------------------------------------------------------*/
 230
 231 /* most "how to use the hardware" policy choices are in userspace:
 232  * mapping endpoint roles (which the driver needs) to the capabilities
 233  * which the usb controller has.  most of those capabilities are exposed
 234  * implicitly, starting with the driver name and then endpoint names.
 235  */
 236
 237 static const char *CHIP;
 238
 239 /*----------------------------------------------------------------------*/
 240
 241 /* NOTE:  don't use dev_printk calls before binding to the gadget
 242  * at the end of ep0 configuration, or after unbind.
 243  */
 244
 245 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
 246 #define xprintk(d,level,fmt,args...) \
 247         printk(level "%s: " fmt , shortname , ## args)
 248
 249 #ifdef DEBUG
 250 #define DBG(dev,fmt,args...) \
 251         xprintk(dev , KERN_DEBUG , fmt , ## args)
 252 #else
 253 #define DBG(dev,fmt,args...) \
 254         do { } while (0)
 255 #endif /* DEBUG */
 256
 257 #ifdef VERBOSE
 258 #define VDEBUG  DBG
 259 #else
 260 #define VDEBUG(dev,fmt,args...) \
 261         do { } while (0)
 262 #endif /* DEBUG */
 263
 264 #define ERROR(dev,fmt,args...) \
 265         xprintk(dev , KERN_ERR , fmt , ## args)
 266 #define WARN(dev,fmt,args...) \
 267         xprintk(dev , KERN_WARNING , fmt , ## args)
 268 #define INFO(dev,fmt,args...) \
 269         xprintk(dev , KERN_INFO , fmt , ## args)
 270
 271
 272 /*----------------------------------------------------------------------*/
 273
 274 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 275  *
 276  * After opening, configure non-control endpoints.  Then use normal
 277  * stream read() and write() requests; and maybe ioctl() to get more
 278  * precise FIFO status when recovering from cancellation.
 279  */
 280
 281 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 282 {
 283         struct ep_data  *epdata = ep->driver_data;
 284
 285         if (!req->context)
 286                 return;
 287         if (req->status)
 288                 epdata->status = req->status;
 289         else
 290                 epdata->status = req->actual;
 291         complete ((struct completion *)req->context);
 292 }
 293
 294 /* tasklock endpoint, returning when it's connected.
 295  * still need dev->lock to use epdata->ep.
 296  */
 297 static int
 298 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
 299 {
 300         int     val;
 301
 302         if (f_flags & O_NONBLOCK) {
 303                 if (down_trylock (&epdata->lock) != 0)
 304                         goto nonblock;
 305                 if (epdata->state != STATE_EP_ENABLED) {
 306                         up (&epdata->lock);
 307 nonblock:
 308                         val = -EAGAIN;
 309                 } else
 310                         val = 0;
 311                 return val;
 312         }
 313
 314         if ((val = down_interruptible (&epdata->lock)) < 0)
 315                 return val;
 316 newstate:
 317         switch (epdata->state) {
 318         case STATE_EP_ENABLED:
 319                 break;
 320         case STATE_EP_DEFER_ENABLE:
 321                 DBG (epdata->dev, "%s wait for host\n", epdata->name);
 322                 if ((val = wait_event_interruptible (epdata->wait,
 323                                 epdata->state != STATE_EP_DEFER_ENABLE
 324                                 || epdata->dev->state == STATE_DEV_UNBOUND
 325                                 )) < 0)
 326                         goto fail;
 327                 goto newstate;
 328         // case STATE_EP_DISABLED:              /* "can't happen" */
 329         // case STATE_EP_READY:                 /* "can't happen" */
 330         default:                                /* error! */
 331                 pr_debug ("%s: ep %p not available, state %d\n",
 332                                 shortname, epdata, epdata->state);
 333                 // FALLTHROUGH
 334         case STATE_EP_UNBOUND:                  /* clean disconnect */
 335                 val = -ENODEV;
 336 fail:
 337                 up (&epdata->lock);
 338         }
 339         return val;
 340 }
 341
 342 static ssize_t
 343 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 344 {
 345         DECLARE_COMPLETION (done);
 346         int value;
 347
 348         spin_lock_irq (&epdata->dev->lock);
 349         if (likely (epdata->ep != NULL)) {
 350                 struct usb_request      *req = epdata->req;
 351
 352                 req->context = &done;
 353                 req->complete = epio_complete;
 354                 req->buf = buf;
 355                 req->length = len;
 356                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 357         } else
 358                 value = -ENODEV;
 359         spin_unlock_irq (&epdata->dev->lock);
 360
 361         if (likely (value == 0)) {
 362                 value = wait_event_interruptible (done.wait, done.done);
 363                 if (value != 0) {
 364                         spin_lock_irq (&epdata->dev->lock);
 365                         if (likely (epdata->ep != NULL)) {
 366                                 DBG (epdata->dev, "%s i/o interrupted\n",
 367                                                 epdata->name);
 368                                 usb_ep_dequeue (epdata->ep, epdata->req);
 369                                 spin_unlock_irq (&epdata->dev->lock);
 370
 371                                 wait_event (done.wait, done.done);
 372                                 if (epdata->status == -ECONNRESET)
 373                                         epdata->status = -EINTR;
 374                         } else {
 375                                 spin_unlock_irq (&epdata->dev->lock);
 376
 377                                 DBG (epdata->dev, "endpoint gone\n");
 378                                 epdata->status = -ENODEV;
 379                         }
 380                 }
 381                 return epdata->status;
 382         }
 383         return value;
 384 }
 385
 386
 387 /* handle a synchronous OUT bulk/intr/iso transfer */
 388 static ssize_t
 389 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 390 {
 391         struct ep_data          *data = fd->private_data;
 392         void                    *kbuf;
 393         ssize_t                 value;
 394
 395         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 396                 return value;
 397
 398         /* halt any endpoint by doing a "wrong direction" i/o call */
 399         if (data->desc.bEndpointAddress & USB_DIR_IN) {
 400                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 401                                 == USB_ENDPOINT_XFER_ISOC)
 402                         return -EINVAL;
 403                 DBG (data->dev, "%s halt\n", data->name);
 404                 spin_lock_irq (&data->dev->lock);
 405                 if (likely (data->ep != NULL))
 406                         usb_ep_set_halt (data->ep);
 407                 spin_unlock_irq (&data->dev->lock);
 408                 up (&data->lock);
 409                 return -EBADMSG;
 410         }
 411
 412         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
 413
 414         value = -ENOMEM;
 415         kbuf = kmalloc (len, SLAB_KERNEL);
 416         if (unlikely (!kbuf))
 417                 goto free1;
 418
 419         value = ep_io (data, kbuf, len);
 420         VDEBUG (data->dev, "%s read %d OUT, status %d\n",
 421                 data->name, len, value);
 422         if (value >= 0 && copy_to_user (buf, kbuf, value))
 423                 value = -EFAULT;
 424
 425 free1:
 426         up (&data->lock);
 427         kfree (kbuf);
 428         return value;
 429 }
 430
 431 /* handle a synchronous IN bulk/intr/iso transfer */
 432 static ssize_t
 433 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 434 {
 435         struct ep_data          *data = fd->private_data;
 436         void                    *kbuf;
 437         ssize_t                 value;
 438
 439         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 440                 return value;
 441
 442         /* halt any endpoint by doing a "wrong direction" i/o call */
 443         if (!(data->desc.bEndpointAddress & USB_DIR_IN)) {
 444                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 445                                 == USB_ENDPOINT_XFER_ISOC)
 446                         return -EINVAL;
 447                 DBG (data->dev, "%s halt\n", data->name);
 448                 spin_lock_irq (&data->dev->lock);
 449                 if (likely (data->ep != NULL))
 450                         usb_ep_set_halt (data->ep);
 451                 spin_unlock_irq (&data->dev->lock);
 452                 up (&data->lock);
 453                 return -EBADMSG;
 454         }
 455
 456         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
 457
 458         value = -ENOMEM;
 459         kbuf = kmalloc (len, SLAB_KERNEL);
 460         if (!kbuf)
 461                 goto free1;
 462         if (copy_from_user (kbuf, buf, len)) {
 463                 value = -EFAULT;
 464                 goto free1;
 465         }
 466
 467         value = ep_io (data, kbuf, len);
 468         VDEBUG (data->dev, "%s write %d IN, status %d\n",
 469                 data->name, len, value);
 470 free1:
 471         up (&data->lock);
 472         kfree (kbuf);
 473         return value;
 474 }
 475
 476 static int
 477 ep_release (struct inode *inode, struct file *fd)
 478 {
 479         struct ep_data          *data = fd->private_data;
 480
 481         /* clean up if this can be reopened */
 482         if (data->state != STATE_EP_UNBOUND) {
 483                 data->state = STATE_EP_DISABLED;
 484                 data->desc.bDescriptorType = 0;
 485                 data->hs_desc.bDescriptorType = 0;
 486         }
 487         put_ep (data);
 488         return 0;
 489 }
 490
 491 static int ep_ioctl (struct inode *inode, struct file *fd,
 492                 unsigned code, unsigned long value)
 493 {
 494         struct ep_data          *data = fd->private_data;
 495         int                     status;
 496
 497         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 498                 return status;
 499
 500         spin_lock_irq (&data->dev->lock);
 501         if (likely (data->ep != NULL)) {
 502                 switch (code) {
 503                 case GADGETFS_FIFO_STATUS:
 504                         status = usb_ep_fifo_status (data->ep);
 505                         break;
 506                 case GADGETFS_FIFO_FLUSH:
 507                         usb_ep_fifo_flush (data->ep);
 508                         break;
 509                 case GADGETFS_CLEAR_HALT:
 510                         status = usb_ep_clear_halt (data->ep);
 511                         break;
 512                 default:
 513                         status = -ENOTTY;
 514                 }
 515         } else
 516                 status = -ENODEV;
 517         spin_unlock_irq (&data->dev->lock);
 518         up (&data->lock);
 519         return status;
 520 }
 521
 522 /*----------------------------------------------------------------------*/
 523
 524 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 525
 526 struct kiocb_priv {
 527         struct usb_request      *req;
 528         struct ep_data          *epdata;
 529         void                    *buf;
 530         char __user             *ubuf;
 531         unsigned                actual;
 532 };
 533
 534 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
 535 {
 536         struct kiocb_priv       *priv = iocb->private;
 537         struct ep_data          *epdata;
 538         int                     value;
 539
 540         local_irq_disable();
 541         epdata = priv->epdata;
 542         // spin_lock(&epdata->dev->lock);
 543         kiocbSetCancelled(iocb);
 544         if (likely(epdata && epdata->ep && priv->req))
 545                 value = usb_ep_dequeue (epdata->ep, priv->req);
 546         else
 547                 value = -EINVAL;
 548         // spin_unlock(&epdata->dev->lock);
 549         local_irq_enable();
 550
 551         aio_put_req(iocb);
 552         return value;
 553 }
 554
 555 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
 556 {
 557         struct kiocb_priv       *priv = iocb->private;
 558         ssize_t                 status = priv->actual;
 559
 560         /* we "retry" to get the right mm context for this: */
 561         status = copy_to_user(priv->ubuf, priv->buf, priv->actual);
 562         if (unlikely(0 != status))
 563                 status = -EFAULT;
 564         else
 565                 status = priv->actual;
 566         kfree(priv->buf);
 567         kfree(priv);
 568         aio_put_req(iocb);
 569         return status;
 570 }
 571
 572 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 573 {
 574         struct kiocb            *iocb = req->context;
 575         struct kiocb_priv       *priv = iocb->private;
 576         struct ep_data          *epdata = priv->epdata;
 577
 578         /* lock against disconnect (and ideally, cancel) */
 579         spin_lock(&epdata->dev->lock);
 580         priv->req = NULL;
 581         priv->epdata = NULL;
 582         if (NULL == iocb->ki_retry
 583                         || unlikely(0 == req->actual)
 584                         || unlikely(kiocbIsCancelled(iocb))) {
 585                 kfree(req->buf);
 586                 kfree(priv);
 587                 iocb->private = NULL;
 588                 /* aio_complete() reports bytes-transferred _and_ faults */
 589                 if (unlikely(kiocbIsCancelled(iocb)))
 590                         aio_put_req(iocb);
 591                 else
 592                         aio_complete(iocb,
 593                                 req->actual ? req->actual : req->status,
 594                                 req->status);
 595         } else {
 596                 /* retry() won't report both; so we hide some faults */
 597                 if (unlikely(0 != req->status))
 598                         DBG(epdata->dev, "%s fault %d len %d\n",
 599                                 ep->name, req->status, req->actual);
 600
 601                 priv->buf = req->buf;
 602                 priv->actual = req->actual;
 603                 kick_iocb(iocb);
 604         }
 605         spin_unlock(&epdata->dev->lock);
 606
 607         usb_ep_free_request(ep, req);
 608         put_ep(epdata);
 609 }
 610
 611 static ssize_t
 612 ep_aio_rwtail(
 613         struct kiocb    *iocb,
 614         char            *buf,
 615         size_t          len,
 616         struct ep_data  *epdata,
 617         char __user     *ubuf
 618 )
 619 {
 620         struct kiocb_priv       *priv = (void *) &iocb->private;
 621         struct usb_request      *req;
 622         ssize_t                 value;
 623
 624         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 625         if (!priv) {
 626                 value = -ENOMEM;
 627 fail:
 628                 kfree(buf);
 629                 return value;
 630         }
 631         iocb->private = priv;
 632         priv->ubuf = ubuf;
 633
 634         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 635         if (unlikely(value < 0)) {
 636                 kfree(priv);
 637                 goto fail;
 638         }
 639
 640         iocb->ki_cancel = ep_aio_cancel;
 641         get_ep(epdata);
 642         priv->epdata = epdata;
 643         priv->actual = 0;
 644
 645         /* each kiocb is coupled to one usb_request, but we can't
 646          * allocate or submit those if the host disconnected.
 647          */
 648         spin_lock_irq(&epdata->dev->lock);
 649         if (likely(epdata->ep)) {
 650                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 651                 if (likely(req)) {
 652                         priv->req = req;
 653                         req->buf = buf;
 654                         req->length = len;
 655                         req->complete = ep_aio_complete;
 656                         req->context = iocb;
 657                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 658                         if (unlikely(0 != value))
 659                                 usb_ep_free_request(epdata->ep, req);
 660                 } else
 661                         value = -EAGAIN;
 662         } else
 663                 value = -ENODEV;
 664         spin_unlock_irq(&epdata->dev->lock);
 665
 666         up(&epdata->lock);
 667
 668         if (unlikely(value)) {
 669                 kfree(priv);
 670                 put_ep(epdata);
 671         } else
 672                 value = -EIOCBQUEUED;
 673         return value;
 674 }
 675
 676 static ssize_t
 677 ep_aio_read(struct kiocb *iocb, char __user *ubuf, size_t len, loff_t o)
 678 {
 679         struct ep_data          *epdata = iocb->ki_filp->private_data;
 680         char                    *buf;
 681
 682         if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN))
 683                 return -EINVAL;
 684         buf = kmalloc(len, GFP_KERNEL);
 685         if (unlikely(!buf))
 686                 return -ENOMEM;
 687         iocb->ki_retry = ep_aio_read_retry;
 688         return ep_aio_rwtail(iocb, buf, len, epdata, ubuf);
 689 }
 690
 691 static ssize_t
 692 ep_aio_write(struct kiocb *iocb, const char __user *ubuf, size_t len, loff_t o)
 693 {
 694         struct ep_data          *epdata = iocb->ki_filp->private_data;
 695         char                    *buf;
 696
 697         if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN)))
 698                 return -EINVAL;
 699         buf = kmalloc(len, GFP_KERNEL);
 700         if (unlikely(!buf))
 701                 return -ENOMEM;
 702         if (unlikely(copy_from_user(buf, ubuf, len) != 0)) {
 703                 kfree(buf);
 704                 return -EFAULT;
 705         }
 706         return ep_aio_rwtail(iocb, buf, len, epdata, NULL);
 707 }
 708
 709 /*----------------------------------------------------------------------*/
 710
 711 /* used after endpoint configuration */
 712 static struct file_operations ep_io_operations = {
 713         .owner =        THIS_MODULE,
 714         .llseek =       no_llseek,
 715
 716         .read =         ep_read,
 717         .write =        ep_write,
 718         .ioctl =        ep_ioctl,
 719         .release =      ep_release,
 720
 721         .aio_read =     ep_aio_read,
 722         .aio_write =    ep_aio_write,
 723 };
 724
 725 /* ENDPOINT INITIALIZATION
 726  *
 727  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 728  *     status = write (fd, descriptors, sizeof descriptors)
 729  *
 730  * That write establishes the endpoint configuration, configuring
 731  * the controller to process bulk, interrupt, or isochronous transfers
 732  * at the right maxpacket size, and so on.
 733  *
 734  * The descriptors are message type 1, identified by a host order u32
 735  * at the beginning of what's written.  Descriptor order is: full/low
 736  * speed descriptor, then optional high speed descriptor.
 737  */
 738 static ssize_t
 739 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 740 {
 741         struct ep_data          *data = fd->private_data;
 742         struct usb_ep           *ep;
 743         u32                     tag;
 744         int                     value;
 745
 746         if ((value = down_interruptible (&data->lock)) < 0)
 747                 return value;
 748
 749         if (data->state != STATE_EP_READY) {
 750                 value = -EL2HLT;
 751                 goto fail;
 752         }
 753
 754         value = len;
 755         if (len < USB_DT_ENDPOINT_SIZE + 4)
 756                 goto fail0;
 757
 758         /* we might need to change message format someday */
 759         if (copy_from_user (&tag, buf, 4)) {
 760                 goto fail1;
 761         }
 762         if (tag != 1) {
 763                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 764                 goto fail0;
 765         }
 766         buf += 4;
 767         len -= 4;
 768
 769         /* NOTE:  audio endpoint extensions not accepted here;
 770          * just don't include the extra bytes.
 771          */
 772
 773         /* full/low speed descriptor, then high speed */
 774         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 775                 goto fail1;
 776         }
 777         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 778                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 779                 goto fail0;
 780         if (len != USB_DT_ENDPOINT_SIZE) {
 781                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 782                         goto fail0;
 783                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 784                                         USB_DT_ENDPOINT_SIZE)) {
 785                         goto fail1;
 786                 }
 787                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 788                                 || data->hs_desc.bDescriptorType
 789                                         != USB_DT_ENDPOINT) {
 790                         DBG(data->dev, "config %s, bad hs length or type\n",
 791                                         data->name);
 792                         goto fail0;
 793                 }
 794         }
 795         value = len;
 796
 797         spin_lock_irq (&data->dev->lock);
 798         if (data->dev->state == STATE_DEV_UNBOUND) {
 799                 value = -ENOENT;
 800                 goto gone;
 801         } else if ((ep = data->ep) == NULL) {
 802                 value = -ENODEV;
 803                 goto gone;
 804         }
 805         switch (data->dev->gadget->speed) {
 806         case USB_SPEED_LOW:
 807         case USB_SPEED_FULL:
 808                 value = usb_ep_enable (ep, &data->desc);
 809                 if (value == 0)
 810                         data->state = STATE_EP_ENABLED;
 811                 break;
 812 #ifdef  HIGHSPEED
 813         case USB_SPEED_HIGH:
 814                 /* fails if caller didn't provide that descriptor... */
 815                 value = usb_ep_enable (ep, &data->hs_desc);
 816                 if (value == 0)
 817                         data->state = STATE_EP_ENABLED;
 818                 break;
 819 #endif
 820         default:
 821                 DBG (data->dev, "unconnected, %s init deferred\n",
 822                                 data->name);
 823                 data->state = STATE_EP_DEFER_ENABLE;
 824         }
 825         if (value == 0)
 826                 fd->f_op = &ep_io_operations;
 827 gone:
 828         spin_unlock_irq (&data->dev->lock);
 829         if (value < 0) {
 830 fail:
 831                 data->desc.bDescriptorType = 0;
 832                 data->hs_desc.bDescriptorType = 0;
 833         }
 834         up (&data->lock);
 835         return value;
 836 fail0:
 837         value = -EINVAL;
 838         goto fail;
 839 fail1:
 840         value = -EFAULT;
 841         goto fail;
 842 }
 843
 844 static int
 845 ep_open (struct inode *inode, struct file *fd)
 846 {
 847         struct ep_data          *data = inode->u.generic_ip;
 848         int                     value = -EBUSY;
 849
 850         if (down_interruptible (&data->lock) != 0)
 851                 return -EINTR;
 852         spin_lock_irq (&data->dev->lock);
 853         if (data->dev->state == STATE_DEV_UNBOUND)
 854                 value = -ENOENT;
 855         else if (data->state == STATE_EP_DISABLED) {
 856                 value = 0;
 857                 data->state = STATE_EP_READY;
 858                 get_ep (data);
 859                 fd->private_data = data;
 860                 VDEBUG (data->dev, "%s ready\n", data->name);
 861         } else
 862                 DBG (data->dev, "%s state %d\n",
 863                         data->name, data->state);
 864         spin_unlock_irq (&data->dev->lock);
 865         up (&data->lock);
 866         return value;
 867 }
 868
 869 /* used before endpoint configuration */
 870 static struct file_operations ep_config_operations = {
 871         .owner =        THIS_MODULE,
 872         .llseek =       no_llseek,
 873
 874         .open =         ep_open,
 875         .write =        ep_config,
 876         .release =      ep_release,
 877 };
 878
 879 /*----------------------------------------------------------------------*/
 880
 881 /* EP0 IMPLEMENTATION can be partly in userspace.
 882  *
 883  * Drivers that use this facility receive various events, including
 884  * control requests the kernel doesn't handle.  Drivers that don't
 885  * use this facility may be too simple-minded for real applications.
 886  */
 887
 888 static inline void ep0_readable (struct dev_data *dev)
 889 {
 890         wake_up (&dev->wait);
 891         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 892 }
 893
 894 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 895 {
 896         struct dev_data         *dev = ep->driver_data;
 897
 898         if (req->buf != dev->rbuf) {
 899                 usb_ep_free_buffer (ep, req->buf, req->dma, req->length);
 900                 req->buf = dev->rbuf;
 901                 req->dma = DMA_ADDR_INVALID;
 902         }
 903         req->complete = epio_complete;
 904         dev->setup_out_ready = 0;
 905 }
 906
 907 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 908 {
 909         struct dev_data         *dev = ep->driver_data;
 910         int                     free = 1;
 911
 912         /* for control OUT, data must still get to userspace */
 913         if (!dev->setup_in) {
 914                 dev->setup_out_error = (req->status != 0);
 915                 if (!dev->setup_out_error)
 916                         free = 0;
 917                 dev->setup_out_ready = 1;
 918                 ep0_readable (dev);
 919         } else if (dev->state == STATE_SETUP)
 920                 dev->state = STATE_CONNECTED;
 921
 922         /* clean up as appropriate */
 923         if (free && req->buf != &dev->rbuf)
 924                 clean_req (ep, req);
 925         req->complete = epio_complete;
 926 }
 927
 928 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 929 {
 930         struct dev_data *dev = ep->driver_data;
 931
 932         if (dev->setup_out_ready) {
 933                 DBG (dev, "ep0 request busy!\n");
 934                 return -EBUSY;
 935         }
 936         if (len > sizeof (dev->rbuf))
 937                 req->buf = usb_ep_alloc_buffer (ep, len, &req->dma, GFP_ATOMIC);
 938         if (req->buf == 0) {
 939                 req->buf = dev->rbuf;
 940                 return -ENOMEM;
 941         }
 942         req->complete = ep0_complete;
 943         req->length = len;
 944         return 0;
 945 }
 946
 947 static ssize_t
 948 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 949 {
 950         struct dev_data                 *dev = fd->private_data;
 951         ssize_t                         retval;
 952         enum ep0_state                  state;
 953
 954         spin_lock_irq (&dev->lock);
 955
 956         /* report fd mode change before acting on it */
 957         if (dev->setup_abort) {
 958                 dev->setup_abort = 0;
 959                 retval = -EIDRM;
 960                 goto done;
 961         }
 962
 963         /* control DATA stage */
 964         if ((state = dev->state) == STATE_SETUP) {
 965
 966                 if (dev->setup_in) {            /* stall IN */
 967                         VDEBUG(dev, "ep0in stall\n");
 968                         (void) usb_ep_set_halt (dev->gadget->ep0);
 969                         retval = -EL2HLT;
 970                         dev->state = STATE_CONNECTED;
 971
 972                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
 973                         struct usb_ep           *ep = dev->gadget->ep0;
 974                         struct usb_request      *req = dev->req;
 975
 976                         if ((retval = setup_req (ep, req, 0)) == 0)
 977                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
 978                         dev->state = STATE_CONNECTED;
 979
 980                         /* assume that was SET_CONFIGURATION */
 981                         if (dev->current_config) {
 982                                 unsigned power;
 983 #ifdef  HIGHSPEED
 984                                 if (dev->gadget->speed == USB_SPEED_HIGH)
 985                                         power = dev->hs_config->bMaxPower;
 986                                 else
 987 #endif
 988                                         power = dev->config->bMaxPower;
 989                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
 990                         }
 991
 992                 } else {                        /* collect OUT data */
 993                         if ((fd->f_flags & O_NONBLOCK) != 0
 994                                         && !dev->setup_out_ready) {
 995                                 retval = -EAGAIN;
 996                                 goto done;
 997                         }
 998                         spin_unlock_irq (&dev->lock);
 999                         retval = wait_event_interruptible (dev->wait,
1000                                         dev->setup_out_ready != 0);
1001
1002                         /* FIXME state could change from under us */
1003                         spin_lock_irq (&dev->lock);
1004                         if (retval)
1005                                 goto done;
1006                         if (dev->setup_out_error)
1007                                 retval = -EIO;
1008                         else {
1009                                 len = min (len, (size_t)dev->req->actual);
1010 // FIXME don't call this with the spinlock held ...
1011                                 if (copy_to_user (buf, &dev->req->buf, len))
1012                                         retval = -EFAULT;
1013                                 clean_req (dev->gadget->ep0, dev->req);
1014                                 /* NOTE userspace can't yet choose to stall */
1015                         }
1016                 }
1017                 goto done;
1018         }
1019
1020         /* else normal: return event data */
1021         if (len < sizeof dev->event [0]) {
1022                 retval = -EINVAL;
1023                 goto done;
1024         }
1025         len -= len % sizeof (struct usb_gadgetfs_event);
1026         dev->usermode_setup = 1;
1027
1028 scan:
1029         /* return queued events right away */
1030         if (dev->ev_next != 0) {
1031                 unsigned                i, n;
1032                 int                     tmp = dev->ev_next;
1033
1034                 len = min (len, tmp * sizeof (struct usb_gadgetfs_event));
1035                 n = len / sizeof (struct usb_gadgetfs_event);
1036
1037                 /* ep0 can't deliver events when STATE_SETUP */
1038                 for (i = 0; i < n; i++) {
1039                         if (dev->event [i].type == GADGETFS_SETUP) {
1040                                 len = n = i + 1;
1041                                 len *= sizeof (struct usb_gadgetfs_event);
1042                                 n = 0;
1043                                 break;
1044                         }
1045                 }
1046                 spin_unlock_irq (&dev->lock);
1047                 if (copy_to_user (buf, &dev->event, len))
1048                         retval = -EFAULT;
1049                 else
1050                         retval = len;
1051                 if (len > 0) {
1052                         len /= sizeof (struct usb_gadgetfs_event);
1053
1054                         /* NOTE this doesn't guard against broken drivers;
1055                          * concurrent ep0 readers may lose events.
1056                          */
1057                         spin_lock_irq (&dev->lock);
1058                         dev->ev_next -= len;
1059                         if (dev->ev_next != 0)
1060                                 memmove (&dev->event, &dev->event [len],
1061                                         sizeof (struct usb_gadgetfs_event)
1062                                                 * (tmp - len));
1063                         if (n == 0)
1064                                 dev->state = STATE_SETUP;
1065                         spin_unlock_irq (&dev->lock);
1066                 }
1067                 return retval;
1068         }
1069         if (fd->f_flags & O_NONBLOCK) {
1070                 retval = -EAGAIN;
1071                 goto done;
1072         }
1073
1074         switch (state) {
1075         default:
1076                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, state);
1077                 retval = -ESRCH;
1078                 break;
1079         case STATE_UNCONNECTED:
1080         case STATE_CONNECTED:
1081                 spin_unlock_irq (&dev->lock);
1082                 DBG (dev, "%s wait\n", __FUNCTION__);
1083
1084                 /* wait for events */
1085                 retval = wait_event_interruptible (dev->wait,
1086                                 dev->ev_next != 0);
1087                 if (retval < 0)
1088                         return retval;
1089                 spin_lock_irq (&dev->lock);
1090                 goto scan;
1091         }
1092
1093 done:
1094         spin_unlock_irq (&dev->lock);
1095         return retval;
1096 }
1097
1098 static struct usb_gadgetfs_event *
1099 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1100 {
1101         struct usb_gadgetfs_event       *event;
1102         unsigned                        i;
1103
1104         switch (type) {
1105         /* these events purge the queue */
1106         case GADGETFS_DISCONNECT:
1107                 if (dev->state == STATE_SETUP)
1108                         dev->setup_abort = 1;
1109                 // FALL THROUGH
1110         case GADGETFS_CONNECT:
1111                 dev->ev_next = 0;
1112                 break;
1113         case GADGETFS_SETUP:            /* previous request timed out */
1114         case GADGETFS_SUSPEND:          /* same effect */
1115                 /* these events can't be repeated */
1116                 for (i = 0; i != dev->ev_next; i++) {
1117                         if (dev->event [i].type != type)
1118                                 continue;
1119                         DBG (dev, "discard old event %d\n", type);
1120                         dev->ev_next--;
1121                         if (i == dev->ev_next)
1122                                 break;
1123                         /* indices start at zero, for simplicity */
1124                         memmove (&dev->event [i], &dev->event [i + 1],
1125                                 sizeof (struct usb_gadgetfs_event)
1126                                         * (dev->ev_next - i));
1127                 }
1128                 break;
1129         default:
1130                 BUG ();
1131         }
1132         event = &dev->event [dev->ev_next++];
1133         BUG_ON (dev->ev_next > N_EVENT);
1134         VDEBUG (dev, "ev %d, next %d\n", type, dev->ev_next);
1135         memset (event, 0, sizeof *event);
1136         event->type = type;
1137         return event;
1138 }
1139
1140 static ssize_t
1141 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1142 {
1143         struct dev_data         *dev = fd->private_data;
1144         ssize_t                 retval = -ESRCH;
1145
1146         spin_lock_irq (&dev->lock);
1147
1148         /* report fd mode change before acting on it */
1149         if (dev->setup_abort) {
1150                 dev->setup_abort = 0;
1151                 retval = -EIDRM;
1152
1153         /* data and/or status stage for control request */
1154         } else if (dev->state == STATE_SETUP) {
1155
1156                 /* IN DATA+STATUS caller makes len <= wLength */
1157                 if (dev->setup_in) {
1158                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1159                         if (retval == 0) {
1160                                 spin_unlock_irq (&dev->lock);
1161                                 if (copy_from_user (dev->req->buf, buf, len))
1162                                         retval = -EFAULT;
1163                                 else
1164                                         retval = usb_ep_queue (
1165                                                 dev->gadget->ep0, dev->req,
1166                                                 GFP_KERNEL);
1167                                 if (retval < 0) {
1168                                         spin_lock_irq (&dev->lock);
1169                                         clean_req (dev->gadget->ep0, dev->req);
1170                                         spin_unlock_irq (&dev->lock);
1171                                 } else
1172                                         retval = len;
1173
1174                                 return retval;
1175                         }
1176
1177                 /* can stall some OUT transfers */
1178                 } else if (dev->setup_can_stall) {
1179                         VDEBUG(dev, "ep0out stall\n");
1180                         (void) usb_ep_set_halt (dev->gadget->ep0);
1181                         retval = -EL2HLT;
1182                         dev->state = STATE_CONNECTED;
1183                 } else {
1184                         DBG(dev, "bogus ep0out stall!\n");
1185                 }
1186         } else
1187                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state);
1188
1189         spin_unlock_irq (&dev->lock);
1190         return retval;
1191 }
1192
1193 static int
1194 ep0_fasync (int f, struct file *fd, int on)
1195 {
1196         struct dev_data         *dev = fd->private_data;
1197         // caller must F_SETOWN before signal delivery happens
1198         VDEBUG (dev, "%s %s\n", __FUNCTION__, on ? "on" : "off");
1199         return fasync_helper (f, fd, on, &dev->fasync);
1200 }
1201
1202 static struct usb_gadget_driver gadgetfs_driver;
1203
1204 static int
1205 dev_release (struct inode *inode, struct file *fd)
1206 {
1207         struct dev_data         *dev = fd->private_data;
1208
1209         /* closing ep0 === shutdown all */
1210
1211         usb_gadget_unregister_driver (&gadgetfs_driver);
1212
1213         /* at this point "good" hardware has disconnected the
1214          * device from USB; the host won't see it any more.
1215          * alternatively, all host requests will time out.
1216          */
1217
1218         fasync_helper (-1, fd, 0, &dev->fasync);
1219         kfree (dev->buf);
1220         dev->buf = NULL;
1221         put_dev (dev);
1222
1223         /* other endpoints were all decoupled from this device */
1224         dev->state = STATE_DEV_DISABLED;
1225         return 0;
1226 }
1227
1228 static int dev_ioctl (struct inode *inode, struct file *fd,
1229                 unsigned code, unsigned long value)
1230 {
1231         struct dev_data         *dev = fd->private_data;
1232         struct usb_gadget       *gadget = dev->gadget;
1233
1234         if (gadget->ops->ioctl)
1235                 return gadget->ops->ioctl (gadget, code, value);
1236         return -ENOTTY;
1237 }
1238
1239 /* used after device configuration */
1240 static struct file_operations ep0_io_operations = {
1241         .owner =        THIS_MODULE,
1242         .llseek =       no_llseek,
1243
1244         .read =         ep0_read,
1245         .write =        ep0_write,
1246         .fasync =       ep0_fasync,
1247         // .poll =      ep0_poll,
1248         .ioctl =        dev_ioctl,
1249         .release =      dev_release,
1250 };
1251
1252 /*----------------------------------------------------------------------*/
1253
1254 /* The in-kernel gadget driver handles most ep0 issues, in particular
1255  * enumerating the single configuration (as provided from user space).
1256  *
1257  * Unrecognized ep0 requests may be handled in user space.
1258  */
1259
1260 #ifdef  HIGHSPEED
1261 static void make_qualifier (struct dev_data *dev)
1262 {
1263         struct usb_qualifier_descriptor         qual;
1264         struct usb_device_descriptor            *desc;
1265
1266         qual.bLength = sizeof qual;
1267         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1268         qual.bcdUSB = __constant_cpu_to_le16 (0x0200);
1269
1270         desc = dev->dev;
1271         qual.bDeviceClass = desc->bDeviceClass;
1272         qual.bDeviceSubClass = desc->bDeviceSubClass;
1273         qual.bDeviceProtocol = desc->bDeviceProtocol;
1274
1275         /* assumes ep0 uses the same value for both speeds ... */
1276         qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
1277
1278         qual.bNumConfigurations = 1;
1279         qual.bRESERVED = 0;
1280
1281         memcpy (dev->rbuf, &qual, sizeof qual);
1282 }
1283 #endif
1284
1285 static int
1286 config_buf (struct dev_data *dev, u8 type, unsigned index)
1287 {
1288         int             len;
1289 #ifdef HIGHSPEED
1290         int             hs;
1291 #endif
1292
1293         /* only one configuration */
1294         if (index > 0)
1295                 return -EINVAL;
1296
1297 #ifdef HIGHSPEED
1298         hs = (dev->gadget->speed == USB_SPEED_HIGH);
1299         if (type == USB_DT_OTHER_SPEED_CONFIG)
1300                 hs = !hs;
1301         if (hs) {
1302                 dev->req->buf = dev->hs_config;
1303                 len = le16_to_cpup (&dev->hs_config->wTotalLength);
1304         } else
1305 #endif
1306         {
1307                 dev->req->buf = dev->config;
1308                 len = le16_to_cpup (&dev->config->wTotalLength);
1309         }
1310         ((u8 *)dev->req->buf) [1] = type;
1311         return len;
1312 }
1313
1314 static int
1315 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1316 {
1317         struct dev_data                 *dev = get_gadget_data (gadget);
1318         struct usb_request              *req = dev->req;
1319         int                             value = -EOPNOTSUPP;
1320         struct usb_gadgetfs_event       *event;
1321         u16                             w_value = ctrl->wValue;
1322         u16                             w_length = ctrl->wLength;
1323
1324         spin_lock (&dev->lock);
1325         dev->setup_abort = 0;
1326         if (dev->state == STATE_UNCONNECTED) {
1327                 struct usb_ep   *ep;
1328                 struct ep_data  *data;
1329
1330                 dev->state = STATE_CONNECTED;
1331                 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1332
1333 #ifdef  HIGHSPEED
1334                 if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) {
1335                         ERROR (dev, "no high speed config??\n");
1336                         return -EINVAL;
1337                 }
1338 #endif  /* HIGHSPEED */
1339
1340                 INFO (dev, "connected\n");
1341                 event = next_event (dev, GADGETFS_CONNECT);
1342                 event->u.speed = gadget->speed;
1343                 ep0_readable (dev);
1344
1345                 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
1346                         data = ep->driver_data;
1347                         /* ... down_trylock (&data->lock) ... */
1348                         if (data->state != STATE_EP_DEFER_ENABLE)
1349                                 continue;
1350 #ifdef  HIGHSPEED
1351                         if (gadget->speed == USB_SPEED_HIGH)
1352                                 value = usb_ep_enable (ep, &data->hs_desc);
1353                         else
1354 #endif  /* HIGHSPEED */
1355                                 value = usb_ep_enable (ep, &data->desc);
1356                         if (value) {
1357                                 ERROR (dev, "deferred %s enable --> %d\n",
1358                                         data->name, value);
1359                                 continue;
1360                         }
1361                         data->state = STATE_EP_ENABLED;
1362                         wake_up (&data->wait);
1363                         DBG (dev, "woke up %s waiters\n", data->name);
1364                 }
1365
1366         /* host may have given up waiting for response.  we can miss control
1367          * requests handled lower down (device/endpoint status and features);
1368          * then ep0_{read,write} will report the wrong status. controller
1369          * driver will have aborted pending i/o.
1370          */
1371         } else if (dev->state == STATE_SETUP)
1372                 dev->setup_abort = 1;
1373
1374         req->buf = dev->rbuf;
1375         req->dma = DMA_ADDR_INVALID;
1376         req->context = NULL;
1377         value = -EOPNOTSUPP;
1378         switch (ctrl->bRequest) {
1379
1380         case USB_REQ_GET_DESCRIPTOR:
1381                 if (ctrl->bRequestType != USB_DIR_IN)
1382                         goto unrecognized;
1383                 switch (w_value >> 8) {
1384
1385                 case USB_DT_DEVICE:
1386                         value = min (w_length, (u16) sizeof *dev->dev);
1387                         req->buf = dev->dev;
1388                         break;
1389 #ifdef  HIGHSPEED
1390                 case USB_DT_DEVICE_QUALIFIER:
1391                         if (!dev->hs_config)
1392                                 break;
1393                         value = min (w_length, (u16)
1394                                 sizeof (struct usb_qualifier_descriptor));
1395                         make_qualifier (dev);
1396                         break;
1397                 case USB_DT_OTHER_SPEED_CONFIG:
1398                         // FALLTHROUGH
1399 #endif
1400                 case USB_DT_CONFIG:
1401                         value = config_buf (dev,
1402                                         w_value >> 8,
1403                                         w_value & 0xff);
1404                         if (value >= 0)
1405                                 value = min (w_length, (u16) value);
1406                         break;
1407                 case USB_DT_STRING:
1408                         goto unrecognized;
1409
1410                 default:                // all others are errors
1411                         break;
1412                 }
1413                 break;
1414
1415         /* currently one config, two speeds */
1416         case USB_REQ_SET_CONFIGURATION:
1417                 if (ctrl->bRequestType != 0)
1418                         break;
1419                 if (0 == (u8) w_value) {
1420                         value = 0;
1421                         dev->current_config = 0;
1422                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1423                         // user mode expected to disable endpoints
1424                 } else {
1425                         u8      config, power;
1426 #ifdef  HIGHSPEED
1427                         if (gadget->speed == USB_SPEED_HIGH) {
1428                                 config = dev->hs_config->bConfigurationValue;
1429                                 power = dev->hs_config->bMaxPower;
1430                         } else
1431 #endif
1432                         {
1433                                 config = dev->config->bConfigurationValue;
1434                                 power = dev->config->bMaxPower;
1435                         }
1436
1437                         if (config == (u8) w_value) {
1438                                 value = 0;
1439                                 dev->current_config = config;
1440                                 usb_gadget_vbus_draw(gadget, 2 * power);
1441                         }
1442                 }
1443
1444                 /* report SET_CONFIGURATION like any other control request,
1445                  * except that usermode may not stall this.  the next
1446                  * request mustn't be allowed start until this finishes:
1447                  * endpoints and threads set up, etc.
1448                  *
1449                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1450                  * has bad/racey automagic that prevents synchronizing here.
1451                  * even kernel mode drivers often miss them.
1452                  */
1453                 if (value == 0) {
1454                         INFO (dev, "configuration #%d\n", dev->current_config);
1455                         if (dev->usermode_setup) {
1456                                 dev->setup_can_stall = 0;
1457                                 goto delegate;
1458                         }
1459                 }
1460                 break;
1461
1462 #ifndef CONFIG_USB_GADGETFS_PXA2XX
1463         /* PXA automagically handles this request too */
1464         case USB_REQ_GET_CONFIGURATION:
1465                 if (ctrl->bRequestType != 0x80)
1466                         break;
1467                 *(u8 *)req->buf = dev->current_config;
1468                 value = min (w_length, (u16) 1);
1469                 break;
1470 #endif
1471
1472         default:
1473 unrecognized:
1474                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1475                         dev->usermode_setup ? "delegate" : "fail",
1476                         ctrl->bRequestType, ctrl->bRequest,
1477                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1478
1479                 /* if there's an ep0 reader, don't stall */
1480                 if (dev->usermode_setup) {
1481                         dev->setup_can_stall = 1;
1482 delegate:
1483                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1484                                                 ? 1 : 0;
1485                         dev->setup_out_ready = 0;
1486                         dev->setup_out_error = 0;
1487                         value = 0;
1488
1489                         /* read DATA stage for OUT right away */
1490                         if (unlikely (!dev->setup_in && w_length)) {
1491                                 value = setup_req (gadget->ep0, dev->req,
1492                                                         w_length);
1493                                 if (value < 0)
1494                                         break;
1495                                 value = usb_ep_queue (gadget->ep0, dev->req,
1496                                                         GFP_ATOMIC);
1497                                 if (value < 0) {
1498                                         clean_req (gadget->ep0, dev->req);
1499                                         break;
1500                                 }
1501
1502                                 /* we can't currently stall these */
1503                                 dev->setup_can_stall = 0;
1504                         }
1505
1506                         /* state changes when reader collects event */
1507                         event = next_event (dev, GADGETFS_SETUP);
1508                         event->u.setup = *ctrl;
1509                         ep0_readable (dev);
1510                         spin_unlock (&dev->lock);
1511                         return 0;
1512                 }
1513         }
1514
1515         /* proceed with data transfer and status phases? */
1516         if (value >= 0 && dev->state != STATE_SETUP) {
1517                 req->length = value;
1518                 req->zero = value < w_length;
1519                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1520                 if (value < 0) {
1521                         DBG (dev, "ep_queue --> %d\n", value);
1522                         req->status = 0;
1523                 }
1524         }
1525
1526         /* device stalls when value < 0 */
1527         spin_unlock (&dev->lock);
1528         return value;
1529 }
1530
1531 static void destroy_ep_files (struct dev_data *dev)
1532 {
1533         struct list_head        *entry, *tmp;
1534
1535         DBG (dev, "%s %d\n", __FUNCTION__, dev->state);
1536
1537         /* dev->state must prevent interference */
1538 restart:
1539         spin_lock_irq (&dev->lock);
1540         list_for_each_safe (entry, tmp, &dev->epfiles) {
1541                 struct ep_data  *ep;
1542                 struct inode    *parent;
1543                 struct dentry   *dentry;
1544
1545                 /* break link to FS */
1546                 ep = list_entry (entry, struct ep_data, epfiles);
1547                 list_del_init (&ep->epfiles);
1548                 dentry = ep->dentry;
1549                 ep->dentry = NULL;
1550                 parent = dentry->d_parent->d_inode;
1551
1552                 /* break link to controller */
1553                 if (ep->state == STATE_EP_ENABLED)
1554                         (void) usb_ep_disable (ep->ep);
1555                 ep->state = STATE_EP_UNBOUND;
1556                 usb_ep_free_request (ep->ep, ep->req);
1557                 ep->ep = NULL;
1558                 wake_up (&ep->wait);
1559                 put_ep (ep);
1560
1561                 spin_unlock_irq (&dev->lock);
1562
1563                 /* break link to dcache */
1564                 down (&parent->i_sem);
1565                 d_delete (dentry);
1566                 dput (dentry);
1567                 up (&parent->i_sem);
1568
1569                 /* fds may still be open */
1570                 goto restart;
1571         }
1572         spin_unlock_irq (&dev->lock);
1573 }
1574
1575
1576 static struct inode *
1577 gadgetfs_create_file (struct super_block *sb, char const *name,
1578                 void *data, struct file_operations *fops,
1579                 struct dentry **dentry_p);
1580
1581 static int activate_ep_files (struct dev_data *dev)
1582 {
1583         struct usb_ep   *ep;
1584
1585         gadget_for_each_ep (ep, dev->gadget) {
1586                 struct ep_data  *data;
1587
1588                 data = kmalloc (sizeof *data, GFP_KERNEL);
1589                 if (!data)
1590                         goto enomem;
1591                 memset (data, 0, sizeof data);
1592                 data->state = STATE_EP_DISABLED;
1593                 init_MUTEX (&data->lock);
1594                 init_waitqueue_head (&data->wait);
1595
1596                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1597                 atomic_set (&data->count, 1);
1598                 data->dev = dev;
1599                 get_dev (dev);
1600
1601                 data->ep = ep;
1602                 ep->driver_data = data;
1603
1604                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1605                 if (!data->req)
1606                         goto enomem;
1607
1608                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1609                                 data, &ep_config_operations,
1610                                 &data->dentry);
1611                 if (!data->inode) {
1612                         kfree (data);
1613                         goto enomem;
1614                 }
1615                 list_add_tail (&data->epfiles, &dev->epfiles);
1616         }
1617         return 0;
1618
1619 enomem:
1620         DBG (dev, "%s enomem\n", __FUNCTION__);
1621         destroy_ep_files (dev);
1622         return -ENOMEM;
1623 }
1624
1625 static void
1626 gadgetfs_unbind (struct usb_gadget *gadget)
1627 {
1628         struct dev_data         *dev = get_gadget_data (gadget);
1629
1630         DBG (dev, "%s\n", __FUNCTION__);
1631
1632         spin_lock_irq (&dev->lock);
1633         dev->state = STATE_DEV_UNBOUND;
1634         spin_unlock_irq (&dev->lock);
1635
1636         destroy_ep_files (dev);
1637         gadget->ep0->driver_data = NULL;
1638         set_gadget_data (gadget, NULL);
1639
1640         /* we've already been disconnected ... no i/o is active */
1641         if (dev->req)
1642                 usb_ep_free_request (gadget->ep0, dev->req);
1643         DBG (dev, "%s done\n", __FUNCTION__);
1644         put_dev (dev);
1645 }
1646
1647 static struct dev_data          *the_device;
1648
1649 static int
1650 gadgetfs_bind (struct usb_gadget *gadget)
1651 {
1652         struct dev_data         *dev = the_device;
1653
1654         if (!dev)
1655                 return -ESRCH;
1656         if (0 != strcmp (CHIP, gadget->name)) {
1657                 printk (KERN_ERR "%s expected %s controller not %s\n",
1658                         shortname, CHIP, gadget->name);
1659                 return -ENODEV;
1660         }
1661
1662         set_gadget_data (gadget, dev);
1663         dev->gadget = gadget;
1664         gadget->ep0->driver_data = dev;
1665         dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
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         dev->state = STATE_UNCONNECTED;
1679         get_dev (dev);
1680         return 0;
1681
1682 enomem:
1683         gadgetfs_unbind (gadget);
1684         return -ENOMEM;
1685 }
1686
1687 static void
1688 gadgetfs_disconnect (struct usb_gadget *gadget)
1689 {
1690         struct dev_data         *dev = get_gadget_data (gadget);
1691
1692         if (dev->state == STATE_UNCONNECTED) {
1693                 DBG (dev, "already unconnected\n");
1694                 return;
1695         }
1696         dev->state = STATE_UNCONNECTED;
1697
1698         INFO (dev, "disconnected\n");
1699         spin_lock (&dev->lock);
1700         next_event (dev, GADGETFS_DISCONNECT);
1701         ep0_readable (dev);
1702         spin_unlock (&dev->lock);
1703 }
1704
1705 static void
1706 gadgetfs_suspend (struct usb_gadget *gadget)
1707 {
1708         struct dev_data         *dev = get_gadget_data (gadget);
1709
1710         INFO (dev, "suspended from state %d\n", dev->state);
1711         spin_lock (&dev->lock);
1712         switch (dev->state) {
1713         case STATE_SETUP:               // VERY odd... host died??
1714         case STATE_CONNECTED:
1715         case STATE_UNCONNECTED:
1716                 next_event (dev, GADGETFS_SUSPEND);
1717                 ep0_readable (dev);
1718                 /* FALLTHROUGH */
1719         default:
1720                 break;
1721         }
1722         spin_unlock (&dev->lock);
1723 }
1724
1725 static struct usb_gadget_driver gadgetfs_driver = {
1726 #ifdef  HIGHSPEED
1727         .speed          = USB_SPEED_HIGH,
1728 #else
1729         .speed          = USB_SPEED_FULL,
1730 #endif
1731         .function       = (char *) driver_desc,
1732         .bind           = gadgetfs_bind,
1733         .unbind         = gadgetfs_unbind,
1734         .setup          = gadgetfs_setup,
1735         .disconnect     = gadgetfs_disconnect,
1736         .suspend        = gadgetfs_suspend,
1737
1738         .driver         = {
1739                 .name           = (char *) shortname,
1740                 // .shutdown = ...
1741                 // .suspend = ...
1742                 // .resume = ...
1743         },
1744 };
1745
1746 /*----------------------------------------------------------------------*/
1747
1748 static void gadgetfs_nop(struct usb_gadget *arg) { }
1749
1750 static int gadgetfs_probe (struct usb_gadget *gadget)
1751 {
1752         CHIP = gadget->name;
1753         return -EISNAM;
1754 }
1755
1756 static struct usb_gadget_driver probe_driver = {
1757         .speed          = USB_SPEED_HIGH,
1758         .bind           = gadgetfs_probe,
1759         .unbind         = gadgetfs_nop,
1760         .setup          = (void *)gadgetfs_nop,
1761         .disconnect     = gadgetfs_nop,
1762         .driver         = {
1763                 .name           = "nop",
1764         },
1765 };
1766
1767
1768 /* DEVICE INITIALIZATION
1769  *
1770  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1771  *     status = write (fd, descriptors, sizeof descriptors)
1772  *
1773  * That write establishes the device configuration, so the kernel can
1774  * bind to the controller ... guaranteeing it can handle enumeration
1775  * at all necessary speeds.  Descriptor order is:
1776  *
1777  * . message tag (u32, host order) ... for now, must be zero; it
1778  *      would change to support features like multi-config devices
1779  * . full/low speed config ... all wTotalLength bytes (with interface,
1780  *      class, altsetting, endpoint, and other descriptors)
1781  * . high speed config ... all descriptors, for high speed operation;
1782  *      this one's optional except for high-speed hardware
1783  * . device descriptor
1784  *
1785  * Endpoints are not yet enabled. Drivers may want to immediately
1786  * initialize them, using the /dev/gadget/ep* files that are available
1787  * as soon as the kernel sees the configuration, or they can wait
1788  * until device configuration and interface altsetting changes create
1789  * the need to configure (or unconfigure) them.
1790  *
1791  * After initialization, the device stays active for as long as that
1792  * $CHIP file is open.  Events may then be read from that descriptor,
1793  * such configuration notifications.  More complex drivers will handle
1794  * some control requests in user space.
1795  */
1796
1797 static int is_valid_config (struct usb_config_descriptor *config)
1798 {
1799         return config->bDescriptorType == USB_DT_CONFIG
1800                 && config->bLength == USB_DT_CONFIG_SIZE
1801                 && config->bConfigurationValue != 0
1802                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1803                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1804         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1805         /* FIXME check lengths: walk to end */
1806 }
1807
1808 static ssize_t
1809 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1810 {
1811         struct dev_data         *dev = fd->private_data;
1812         ssize_t                 value = len, length = len;
1813         unsigned                total;
1814         u32                     tag;
1815         char                    *kbuf;
1816
1817         if (dev->state != STATE_OPENED)
1818                 return -EEXIST;
1819
1820         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1821                 return -EINVAL;
1822
1823         /* we might need to change message format someday */
1824         if (copy_from_user (&tag, buf, 4))
1825                 return -EFAULT;
1826         if (tag != 0)
1827                 return -EINVAL;
1828         buf += 4;
1829         length -= 4;
1830
1831         kbuf = kmalloc (length, SLAB_KERNEL);
1832         if (!kbuf)
1833                 return -ENOMEM;
1834         if (copy_from_user (kbuf, buf, length)) {
1835                 kfree (kbuf);
1836                 return -EFAULT;
1837         }
1838
1839         spin_lock_irq (&dev->lock);
1840         value = -EINVAL;
1841         if (dev->buf)
1842                 goto fail;
1843         dev->buf = kbuf;
1844
1845         /* full or low speed config */
1846         dev->config = (void *) kbuf;
1847         total = le16_to_cpup (&dev->config->wTotalLength);
1848         if (!is_valid_config (dev->config) || total >= length)
1849                 goto fail;
1850         kbuf += total;
1851         length -= total;
1852
1853         /* optional high speed config */
1854         if (kbuf [1] == USB_DT_CONFIG) {
1855                 dev->hs_config = (void *) kbuf;
1856                 total = le16_to_cpup (&dev->hs_config->wTotalLength);
1857                 if (!is_valid_config (dev->hs_config) || total >= length)
1858                         goto fail;
1859                 kbuf += total;
1860                 length -= total;
1861         }
1862
1863         /* could support multiple configs, using another encoding! */
1864
1865         /* device descriptor (tweaked for paranoia) */
1866         if (length != USB_DT_DEVICE_SIZE)
1867                 goto fail;
1868         dev->dev = (void *)kbuf;
1869         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1870                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1871                         || dev->dev->bNumConfigurations != 1)
1872                 goto fail;
1873         dev->dev->bNumConfigurations = 1;
1874         dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200);
1875
1876         /* triggers gadgetfs_bind(); then we can enumerate. */
1877         spin_unlock_irq (&dev->lock);
1878         value = usb_gadget_register_driver (&gadgetfs_driver);
1879         if (value != 0) {
1880                 kfree (dev->buf);
1881                 dev->buf = NULL;
1882         } else {
1883                 /* at this point "good" hardware has for the first time
1884                  * let the USB the host see us.  alternatively, if users
1885                  * unplug/replug that will clear all the error state.
1886                  *
1887                  * note:  everything running before here was guaranteed
1888                  * to choke driver model style diagnostics.  from here
1889                  * on, they can work ... except in cleanup paths that
1890                  * kick in after the ep0 descriptor is closed.
1891                  */
1892                 fd->f_op = &ep0_io_operations;
1893                 value = len;
1894         }
1895         return value;
1896
1897 fail:
1898         spin_unlock_irq (&dev->lock);
1899         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __FUNCTION__, value, dev);
1900         kfree (dev->buf);
1901         dev->buf = NULL;
1902         return value;
1903 }
1904
1905 static int
1906 dev_open (struct inode *inode, struct file *fd)
1907 {
1908         struct dev_data         *dev = inode->u.generic_ip;
1909         int                     value = -EBUSY;
1910
1911         if (dev->state == STATE_DEV_DISABLED) {
1912                 dev->ev_next = 0;
1913                 dev->state = STATE_OPENED;
1914                 fd->private_data = dev;
1915                 get_dev (dev);
1916                 value = 0;
1917         }
1918         return value;
1919 }
1920
1921 static struct file_operations dev_init_operations = {
1922         .owner =        THIS_MODULE,
1923         .llseek =       no_llseek,
1924
1925         .open =         dev_open,
1926         .write =        dev_config,
1927         .fasync =       ep0_fasync,
1928         .ioctl =        dev_ioctl,
1929         .release =      dev_release,
1930 };
1931
1932 /*----------------------------------------------------------------------*/
1933
1934 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1935  *
1936  * Mounting the filesystem creates a controller file, used first for
1937  * device configuration then later for event monitoring.
1938  */
1939
1940
1941 /* FIXME PAM etc could set this security policy without mount options
1942  * if epfiles inherited ownership and permissons from ep0 ...
1943  */
1944
1945 static unsigned default_uid;
1946 static unsigned default_gid;
1947 static unsigned default_perm = S_IRUSR | S_IWUSR;
1948
1949 module_param (default_uid, uint, 0644);
1950 module_param (default_gid, uint, 0644);
1951 module_param (default_perm, uint, 0644);
1952
1953
1954 static struct inode *
1955 gadgetfs_make_inode (struct super_block *sb,
1956                 void *data, struct file_operations *fops,
1957                 int mode)
1958 {
1959         struct inode *inode = new_inode (sb);
1960
1961         if (inode) {
1962                 inode->i_mode = mode;
1963                 inode->i_uid = default_uid;
1964                 inode->i_gid = default_gid;
1965                 inode->i_blksize = PAGE_CACHE_SIZE;
1966                 inode->i_blocks = 0;
1967                 inode->i_atime = inode->i_mtime = inode->i_ctime
1968                                 = CURRENT_TIME;
1969                 inode->u.generic_ip = data;
1970                 inode->i_fop = fops;
1971         }
1972         return inode;
1973 }
1974
1975 /* creates in fs root directory, so non-renamable and non-linkable.
1976  * so inode and dentry are paired, until device reconfig.
1977  */
1978 static struct inode *
1979 gadgetfs_create_file (struct super_block *sb, char const *name,
1980                 void *data, struct file_operations *fops,
1981                 struct dentry **dentry_p)
1982 {
1983         struct dentry   *dentry;
1984         struct inode    *inode;
1985
1986         dentry = d_alloc_name(sb->s_root, name);
1987         if (!dentry)
1988                 return NULL;
1989
1990         inode = gadgetfs_make_inode (sb, data, fops,
1991                         S_IFREG | (default_perm & S_IRWXUGO));
1992         if (!inode) {
1993                 dput(dentry);
1994                 return NULL;
1995         }
1996         d_add (dentry, inode);
1997         *dentry_p = dentry;
1998         return inode;
1999 }
2000
2001 static struct super_operations gadget_fs_operations = {
2002         .statfs =       simple_statfs,
2003         .drop_inode =   generic_delete_inode,
2004 };
2005
2006 static int
2007 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2008 {
2009         struct inode    *inode;
2010         struct dentry   *d;
2011         struct dev_data *dev;
2012
2013         if (the_device)
2014                 return -ESRCH;
2015
2016         /* fake probe to determine $CHIP */
2017         (void) usb_gadget_register_driver (&probe_driver);
2018         if (!CHIP)
2019                 return -ENODEV;
2020
2021         /* superblock */
2022         sb->s_blocksize = PAGE_CACHE_SIZE;
2023         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2024         sb->s_magic = GADGETFS_MAGIC;
2025         sb->s_op = &gadget_fs_operations;
2026         sb->s_time_gran = 1;
2027
2028         /* root inode */
2029         inode = gadgetfs_make_inode (sb,
2030                         NULL, &simple_dir_operations,
2031                         S_IFDIR | S_IRUGO | S_IXUGO);
2032         if (!inode)
2033                 return -ENOMEM;
2034         inode->i_op = &simple_dir_inode_operations;
2035         if (!(d = d_alloc_root (inode))) {
2036                 iput (inode);
2037                 return -ENOMEM;
2038         }
2039         sb->s_root = d;
2040
2041         /* the ep0 file is named after the controller we expect;
2042          * user mode code can use it for sanity checks, like we do.
2043          */
2044         dev = dev_new ();
2045         if (!dev)
2046                 return -ENOMEM;
2047
2048         dev->sb = sb;
2049         if (!(inode = gadgetfs_create_file (sb, CHIP,
2050                                 dev, &dev_init_operations,
2051                                 &dev->dentry))) {
2052                 put_dev(dev);
2053                 return -ENOMEM;
2054         }
2055
2056         /* other endpoint files are available after hardware setup,
2057          * from binding to a controller.
2058          */
2059         the_device = dev;
2060         return 0;
2061 }
2062
2063 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2064 static struct super_block *
2065 gadgetfs_get_sb (struct file_system_type *t, int flags,
2066                 const char *path, void *opts)
2067 {
2068         return get_sb_single (t, flags, opts, gadgetfs_fill_super);
2069 }
2070
2071 static void
2072 gadgetfs_kill_sb (struct super_block *sb)
2073 {
2074         kill_litter_super (sb);
2075         if (the_device) {
2076                 put_dev (the_device);
2077                 the_device = NULL;
2078         }
2079 }
2080
2081 /*----------------------------------------------------------------------*/
2082
2083 static struct file_system_type gadgetfs_type = {
2084         .owner          = THIS_MODULE,
2085         .name           = shortname,
2086         .get_sb         = gadgetfs_get_sb,
2087         .kill_sb        = gadgetfs_kill_sb,
2088 };
2089
2090 /*----------------------------------------------------------------------*/
2091
2092 static int __init init (void)
2093 {
2094         int status;
2095
2096         status = register_filesystem (&gadgetfs_type);
2097         if (status == 0)
2098                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2099                         shortname, driver_desc);
2100         return status;
2101 }
2102 module_init (init);
2103
2104 static void __exit cleanup (void)
2105 {
2106         pr_debug ("unregister %s\n", shortname);
2107         unregister_filesystem (&gadgetfs_type);
2108 }
2109 module_exit (cleanup);
2110