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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         unsigned                        setup_wLength;
 139
 140         /* the rest is basically write-once */
 141         struct usb_config_descriptor    *config, *hs_config;
 142         struct usb_device_descriptor    *dev;
 143         struct usb_request              *req;
 144         struct usb_gadget               *gadget;
 145         struct list_head                epfiles;
 146         void                            *buf;
 147         wait_queue_head_t               wait;
 148         struct super_block              *sb;
 149         struct dentry                   *dentry;
 150
 151         /* except this scratch i/o buffer for ep0 */
 152         u8                              rbuf [256];
 153 };
 154
 155 static inline void get_dev (struct dev_data *data)
 156 {
 157         atomic_inc (&data->count);
 158 }
 159
 160 static void put_dev (struct dev_data *data)
 161 {
 162         if (likely (!atomic_dec_and_test (&data->count)))
 163                 return;
 164         /* needs no more cleanup */
 165         BUG_ON (waitqueue_active (&data->wait));
 166         kfree (data);
 167 }
 168
 169 static struct dev_data *dev_new (void)
 170 {
 171         struct dev_data         *dev;
 172
 173         dev = kmalloc (sizeof *dev, GFP_KERNEL);
 174         if (!dev)
 175                 return NULL;
 176         memset (dev, 0, sizeof *dev);
 177         dev->state = STATE_DEV_DISABLED;
 178         atomic_set (&dev->count, 1);
 179         spin_lock_init (&dev->lock);
 180         INIT_LIST_HEAD (&dev->epfiles);
 181         init_waitqueue_head (&dev->wait);
 182         return dev;
 183 }
 184
 185 /*----------------------------------------------------------------------*/
 186
 187 /* other /dev/gadget/$ENDPOINT files represent endpoints */
 188 enum ep_state {
 189         STATE_EP_DISABLED = 0,
 190         STATE_EP_READY,
 191         STATE_EP_DEFER_ENABLE,
 192         STATE_EP_ENABLED,
 193         STATE_EP_UNBOUND,
 194 };
 195
 196 struct ep_data {
 197         struct semaphore                lock;
 198         enum ep_state                   state;
 199         atomic_t                        count;
 200         struct dev_data                 *dev;
 201         /* must hold dev->lock before accessing ep or req */
 202         struct usb_ep                   *ep;
 203         struct usb_request              *req;
 204         ssize_t                         status;
 205         char                            name [16];
 206         struct usb_endpoint_descriptor  desc, hs_desc;
 207         struct list_head                epfiles;
 208         wait_queue_head_t               wait;
 209         struct dentry                   *dentry;
 210         struct inode                    *inode;
 211 };
 212
 213 static inline void get_ep (struct ep_data *data)
 214 {
 215         atomic_inc (&data->count);
 216 }
 217
 218 static void put_ep (struct ep_data *data)
 219 {
 220         if (likely (!atomic_dec_and_test (&data->count)))
 221                 return;
 222         put_dev (data->dev);
 223         /* needs no more cleanup */
 224         BUG_ON (!list_empty (&data->epfiles));
 225         BUG_ON (waitqueue_active (&data->wait));
 226         BUG_ON (down_trylock (&data->lock) != 0);
 227         kfree (data);
 228 }
 229
 230 /*----------------------------------------------------------------------*/
 231
 232 /* most "how to use the hardware" policy choices are in userspace:
 233  * mapping endpoint roles (which the driver needs) to the capabilities
 234  * which the usb controller has.  most of those capabilities are exposed
 235  * implicitly, starting with the driver name and then endpoint names.
 236  */
 237
 238 static const char *CHIP;
 239
 240 /*----------------------------------------------------------------------*/
 241
 242 /* NOTE:  don't use dev_printk calls before binding to the gadget
 243  * at the end of ep0 configuration, or after unbind.
 244  */
 245
 246 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
 247 #define xprintk(d,level,fmt,args...) \
 248         printk(level "%s: " fmt , shortname , ## args)
 249
 250 #ifdef DEBUG
 251 #define DBG(dev,fmt,args...) \
 252         xprintk(dev , KERN_DEBUG , fmt , ## args)
 253 #else
 254 #define DBG(dev,fmt,args...) \
 255         do { } while (0)
 256 #endif /* DEBUG */
 257
 258 #ifdef VERBOSE
 259 #define VDEBUG  DBG
 260 #else
 261 #define VDEBUG(dev,fmt,args...) \
 262         do { } while (0)
 263 #endif /* DEBUG */
 264
 265 #define ERROR(dev,fmt,args...) \
 266         xprintk(dev , KERN_ERR , fmt , ## args)
 267 #define WARN(dev,fmt,args...) \
 268         xprintk(dev , KERN_WARNING , fmt , ## args)
 269 #define INFO(dev,fmt,args...) \
 270         xprintk(dev , KERN_INFO , fmt , ## args)
 271
 272
 273 /*----------------------------------------------------------------------*/
 274
 275 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 276  *
 277  * After opening, configure non-control endpoints.  Then use normal
 278  * stream read() and write() requests; and maybe ioctl() to get more
 279  * precise FIFO status when recovering from cancellation.
 280  */
 281
 282 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 283 {
 284         struct ep_data  *epdata = ep->driver_data;
 285
 286         if (!req->context)
 287                 return;
 288         if (req->status)
 289                 epdata->status = req->status;
 290         else
 291                 epdata->status = req->actual;
 292         complete ((struct completion *)req->context);
 293 }
 294
 295 /* tasklock endpoint, returning when it's connected.
 296  * still need dev->lock to use epdata->ep.
 297  */
 298 static int
 299 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
 300 {
 301         int     val;
 302
 303         if (f_flags & O_NONBLOCK) {
 304                 if (down_trylock (&epdata->lock) != 0)
 305                         goto nonblock;
 306                 if (epdata->state != STATE_EP_ENABLED) {
 307                         up (&epdata->lock);
 308 nonblock:
 309                         val = -EAGAIN;
 310                 } else
 311                         val = 0;
 312                 return val;
 313         }
 314
 315         if ((val = down_interruptible (&epdata->lock)) < 0)
 316                 return val;
 317 newstate:
 318         switch (epdata->state) {
 319         case STATE_EP_ENABLED:
 320                 break;
 321         case STATE_EP_DEFER_ENABLE:
 322                 DBG (epdata->dev, "%s wait for host\n", epdata->name);
 323                 if ((val = wait_event_interruptible (epdata->wait,
 324                                 epdata->state != STATE_EP_DEFER_ENABLE
 325                                 || epdata->dev->state == STATE_DEV_UNBOUND
 326                                 )) < 0)
 327                         goto fail;
 328                 goto newstate;
 329         // case STATE_EP_DISABLED:              /* "can't happen" */
 330         // case STATE_EP_READY:                 /* "can't happen" */
 331         default:                                /* error! */
 332                 pr_debug ("%s: ep %p not available, state %d\n",
 333                                 shortname, epdata, epdata->state);
 334                 // FALLTHROUGH
 335         case STATE_EP_UNBOUND:                  /* clean disconnect */
 336                 val = -ENODEV;
 337 fail:
 338                 up (&epdata->lock);
 339         }
 340         return val;
 341 }
 342
 343 static ssize_t
 344 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 345 {
 346         DECLARE_COMPLETION (done);
 347         int value;
 348
 349         spin_lock_irq (&epdata->dev->lock);
 350         if (likely (epdata->ep != NULL)) {
 351                 struct usb_request      *req = epdata->req;
 352
 353                 req->context = &done;
 354                 req->complete = epio_complete;
 355                 req->buf = buf;
 356                 req->length = len;
 357                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 358         } else
 359                 value = -ENODEV;
 360         spin_unlock_irq (&epdata->dev->lock);
 361
 362         if (likely (value == 0)) {
 363                 value = wait_event_interruptible (done.wait, done.done);
 364                 if (value != 0) {
 365                         spin_lock_irq (&epdata->dev->lock);
 366                         if (likely (epdata->ep != NULL)) {
 367                                 DBG (epdata->dev, "%s i/o interrupted\n",
 368                                                 epdata->name);
 369                                 usb_ep_dequeue (epdata->ep, epdata->req);
 370                                 spin_unlock_irq (&epdata->dev->lock);
 371
 372                                 wait_event (done.wait, done.done);
 373                                 if (epdata->status == -ECONNRESET)
 374                                         epdata->status = -EINTR;
 375                         } else {
 376                                 spin_unlock_irq (&epdata->dev->lock);
 377
 378                                 DBG (epdata->dev, "endpoint gone\n");
 379                                 epdata->status = -ENODEV;
 380                         }
 381                 }
 382                 return epdata->status;
 383         }
 384         return value;
 385 }
 386
 387
 388 /* handle a synchronous OUT bulk/intr/iso transfer */
 389 static ssize_t
 390 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 391 {
 392         struct ep_data          *data = fd->private_data;
 393         void                    *kbuf;
 394         ssize_t                 value;
 395
 396         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 397                 return value;
 398
 399         /* halt any endpoint by doing a "wrong direction" i/o call */
 400         if (data->desc.bEndpointAddress & USB_DIR_IN) {
 401                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 402                                 == USB_ENDPOINT_XFER_ISOC)
 403                         return -EINVAL;
 404                 DBG (data->dev, "%s halt\n", data->name);
 405                 spin_lock_irq (&data->dev->lock);
 406                 if (likely (data->ep != NULL))
 407                         usb_ep_set_halt (data->ep);
 408                 spin_unlock_irq (&data->dev->lock);
 409                 up (&data->lock);
 410                 return -EBADMSG;
 411         }
 412
 413         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
 414
 415         value = -ENOMEM;
 416         kbuf = kmalloc (len, SLAB_KERNEL);
 417         if (unlikely (!kbuf))
 418                 goto free1;
 419
 420         value = ep_io (data, kbuf, len);
 421         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
 422                 data->name, len, (int) value);
 423         if (value >= 0 && copy_to_user (buf, kbuf, value))
 424                 value = -EFAULT;
 425
 426 free1:
 427         up (&data->lock);
 428         kfree (kbuf);
 429         return value;
 430 }
 431
 432 /* handle a synchronous IN bulk/intr/iso transfer */
 433 static ssize_t
 434 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 435 {
 436         struct ep_data          *data = fd->private_data;
 437         void                    *kbuf;
 438         ssize_t                 value;
 439
 440         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 441                 return value;
 442
 443         /* halt any endpoint by doing a "wrong direction" i/o call */
 444         if (!(data->desc.bEndpointAddress & USB_DIR_IN)) {
 445                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 446                                 == USB_ENDPOINT_XFER_ISOC)
 447                         return -EINVAL;
 448                 DBG (data->dev, "%s halt\n", data->name);
 449                 spin_lock_irq (&data->dev->lock);
 450                 if (likely (data->ep != NULL))
 451                         usb_ep_set_halt (data->ep);
 452                 spin_unlock_irq (&data->dev->lock);
 453                 up (&data->lock);
 454                 return -EBADMSG;
 455         }
 456
 457         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
 458
 459         value = -ENOMEM;
 460         kbuf = kmalloc (len, SLAB_KERNEL);
 461         if (!kbuf)
 462                 goto free1;
 463         if (copy_from_user (kbuf, buf, len)) {
 464                 value = -EFAULT;
 465                 goto free1;
 466         }
 467
 468         value = ep_io (data, kbuf, len);
 469         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
 470                 data->name, len, (int) value);
 471 free1:
 472         up (&data->lock);
 473         kfree (kbuf);
 474         return value;
 475 }
 476
 477 static int
 478 ep_release (struct inode *inode, struct file *fd)
 479 {
 480         struct ep_data          *data = fd->private_data;
 481
 482         /* clean up if this can be reopened */
 483         if (data->state != STATE_EP_UNBOUND) {
 484                 data->state = STATE_EP_DISABLED;
 485                 data->desc.bDescriptorType = 0;
 486                 data->hs_desc.bDescriptorType = 0;
 487                 usb_ep_disable(data->ep);
 488         }
 489         put_ep (data);
 490         return 0;
 491 }
 492
 493 static int ep_ioctl (struct inode *inode, struct file *fd,
 494                 unsigned code, unsigned long value)
 495 {
 496         struct ep_data          *data = fd->private_data;
 497         int                     status;
 498
 499         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 500                 return status;
 501
 502         spin_lock_irq (&data->dev->lock);
 503         if (likely (data->ep != NULL)) {
 504                 switch (code) {
 505                 case GADGETFS_FIFO_STATUS:
 506                         status = usb_ep_fifo_status (data->ep);
 507                         break;
 508                 case GADGETFS_FIFO_FLUSH:
 509                         usb_ep_fifo_flush (data->ep);
 510                         break;
 511                 case GADGETFS_CLEAR_HALT:
 512                         status = usb_ep_clear_halt (data->ep);
 513                         break;
 514                 default:
 515                         status = -ENOTTY;
 516                 }
 517         } else
 518                 status = -ENODEV;
 519         spin_unlock_irq (&data->dev->lock);
 520         up (&data->lock);
 521         return status;
 522 }
 523
 524 /*----------------------------------------------------------------------*/
 525
 526 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 527
 528 struct kiocb_priv {
 529         struct usb_request      *req;
 530         struct ep_data          *epdata;
 531         void                    *buf;
 532         char __user             *ubuf;
 533         unsigned                actual;
 534 };
 535
 536 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
 537 {
 538         struct kiocb_priv       *priv = iocb->private;
 539         struct ep_data          *epdata;
 540         int                     value;
 541
 542         local_irq_disable();
 543         epdata = priv->epdata;
 544         // spin_lock(&epdata->dev->lock);
 545         kiocbSetCancelled(iocb);
 546         if (likely(epdata && epdata->ep && priv->req))
 547                 value = usb_ep_dequeue (epdata->ep, priv->req);
 548         else
 549                 value = -EINVAL;
 550         // spin_unlock(&epdata->dev->lock);
 551         local_irq_enable();
 552
 553         aio_put_req(iocb);
 554         return value;
 555 }
 556
 557 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
 558 {
 559         struct kiocb_priv       *priv = iocb->private;
 560         ssize_t                 status = priv->actual;
 561
 562         /* we "retry" to get the right mm context for this: */
 563         status = copy_to_user(priv->ubuf, priv->buf, priv->actual);
 564         if (unlikely(0 != status))
 565                 status = -EFAULT;
 566         else
 567                 status = priv->actual;
 568         kfree(priv->buf);
 569         kfree(priv);
 570         aio_put_req(iocb);
 571         return status;
 572 }
 573
 574 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 575 {
 576         struct kiocb            *iocb = req->context;
 577         struct kiocb_priv       *priv = iocb->private;
 578         struct ep_data          *epdata = priv->epdata;
 579
 580         /* lock against disconnect (and ideally, cancel) */
 581         spin_lock(&epdata->dev->lock);
 582         priv->req = NULL;
 583         priv->epdata = NULL;
 584         if (NULL == iocb->ki_retry
 585                         || unlikely(0 == req->actual)
 586                         || unlikely(kiocbIsCancelled(iocb))) {
 587                 kfree(req->buf);
 588                 kfree(priv);
 589                 iocb->private = NULL;
 590                 /* aio_complete() reports bytes-transferred _and_ faults */
 591                 if (unlikely(kiocbIsCancelled(iocb)))
 592                         aio_put_req(iocb);
 593                 else
 594                         aio_complete(iocb,
 595                                 req->actual ? req->actual : req->status,
 596                                 req->status);
 597         } else {
 598                 /* retry() won't report both; so we hide some faults */
 599                 if (unlikely(0 != req->status))
 600                         DBG(epdata->dev, "%s fault %d len %d\n",
 601                                 ep->name, req->status, req->actual);
 602
 603                 priv->buf = req->buf;
 604                 priv->actual = req->actual;
 605                 kick_iocb(iocb);
 606         }
 607         spin_unlock(&epdata->dev->lock);
 608
 609         usb_ep_free_request(ep, req);
 610         put_ep(epdata);
 611 }
 612
 613 static ssize_t
 614 ep_aio_rwtail(
 615         struct kiocb    *iocb,
 616         char            *buf,
 617         size_t          len,
 618         struct ep_data  *epdata,
 619         char __user     *ubuf
 620 )
 621 {
 622         struct kiocb_priv       *priv = (void *) &iocb->private;
 623         struct usb_request      *req;
 624         ssize_t                 value;
 625
 626         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 627         if (!priv) {
 628                 value = -ENOMEM;
 629 fail:
 630                 kfree(buf);
 631                 return value;
 632         }
 633         iocb->private = priv;
 634         priv->ubuf = ubuf;
 635
 636         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 637         if (unlikely(value < 0)) {
 638                 kfree(priv);
 639                 goto fail;
 640         }
 641
 642         iocb->ki_cancel = ep_aio_cancel;
 643         get_ep(epdata);
 644         priv->epdata = epdata;
 645         priv->actual = 0;
 646
 647         /* each kiocb is coupled to one usb_request, but we can't
 648          * allocate or submit those if the host disconnected.
 649          */
 650         spin_lock_irq(&epdata->dev->lock);
 651         if (likely(epdata->ep)) {
 652                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 653                 if (likely(req)) {
 654                         priv->req = req;
 655                         req->buf = buf;
 656                         req->length = len;
 657                         req->complete = ep_aio_complete;
 658                         req->context = iocb;
 659                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 660                         if (unlikely(0 != value))
 661                                 usb_ep_free_request(epdata->ep, req);
 662                 } else
 663                         value = -EAGAIN;
 664         } else
 665                 value = -ENODEV;
 666         spin_unlock_irq(&epdata->dev->lock);
 667
 668         up(&epdata->lock);
 669
 670         if (unlikely(value)) {
 671                 kfree(priv);
 672                 put_ep(epdata);
 673         } else
 674                 value = -EIOCBQUEUED;
 675         return value;
 676 }
 677
 678 static ssize_t
 679 ep_aio_read(struct kiocb *iocb, char __user *ubuf, size_t len, loff_t o)
 680 {
 681         struct ep_data          *epdata = iocb->ki_filp->private_data;
 682         char                    *buf;
 683
 684         if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN))
 685                 return -EINVAL;
 686         buf = kmalloc(len, GFP_KERNEL);
 687         if (unlikely(!buf))
 688                 return -ENOMEM;
 689         iocb->ki_retry = ep_aio_read_retry;
 690         return ep_aio_rwtail(iocb, buf, len, epdata, ubuf);
 691 }
 692
 693 static ssize_t
 694 ep_aio_write(struct kiocb *iocb, const char __user *ubuf, size_t len, loff_t o)
 695 {
 696         struct ep_data          *epdata = iocb->ki_filp->private_data;
 697         char                    *buf;
 698
 699         if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN)))
 700                 return -EINVAL;
 701         buf = kmalloc(len, GFP_KERNEL);
 702         if (unlikely(!buf))
 703                 return -ENOMEM;
 704         if (unlikely(copy_from_user(buf, ubuf, len) != 0)) {
 705                 kfree(buf);
 706                 return -EFAULT;
 707         }
 708         return ep_aio_rwtail(iocb, buf, len, epdata, NULL);
 709 }
 710
 711 /*----------------------------------------------------------------------*/
 712
 713 /* used after endpoint configuration */
 714 static struct file_operations ep_io_operations = {
 715         .owner =        THIS_MODULE,
 716         .llseek =       no_llseek,
 717
 718         .read =         ep_read,
 719         .write =        ep_write,
 720         .ioctl =        ep_ioctl,
 721         .release =      ep_release,
 722
 723         .aio_read =     ep_aio_read,
 724         .aio_write =    ep_aio_write,
 725 };
 726
 727 /* ENDPOINT INITIALIZATION
 728  *
 729  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 730  *     status = write (fd, descriptors, sizeof descriptors)
 731  *
 732  * That write establishes the endpoint configuration, configuring
 733  * the controller to process bulk, interrupt, or isochronous transfers
 734  * at the right maxpacket size, and so on.
 735  *
 736  * The descriptors are message type 1, identified by a host order u32
 737  * at the beginning of what's written.  Descriptor order is: full/low
 738  * speed descriptor, then optional high speed descriptor.
 739  */
 740 static ssize_t
 741 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 742 {
 743         struct ep_data          *data = fd->private_data;
 744         struct usb_ep           *ep;
 745         u32                     tag;
 746         int                     value;
 747
 748         if ((value = down_interruptible (&data->lock)) < 0)
 749                 return value;
 750
 751         if (data->state != STATE_EP_READY) {
 752                 value = -EL2HLT;
 753                 goto fail;
 754         }
 755
 756         value = len;
 757         if (len < USB_DT_ENDPOINT_SIZE + 4)
 758                 goto fail0;
 759
 760         /* we might need to change message format someday */
 761         if (copy_from_user (&tag, buf, 4)) {
 762                 goto fail1;
 763         }
 764         if (tag != 1) {
 765                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 766                 goto fail0;
 767         }
 768         buf += 4;
 769         len -= 4;
 770
 771         /* NOTE:  audio endpoint extensions not accepted here;
 772          * just don't include the extra bytes.
 773          */
 774
 775         /* full/low speed descriptor, then high speed */
 776         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 777                 goto fail1;
 778         }
 779         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 780                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 781                 goto fail0;
 782         if (len != USB_DT_ENDPOINT_SIZE) {
 783                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 784                         goto fail0;
 785                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 786                                         USB_DT_ENDPOINT_SIZE)) {
 787                         goto fail1;
 788                 }
 789                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 790                                 || data->hs_desc.bDescriptorType
 791                                         != USB_DT_ENDPOINT) {
 792                         DBG(data->dev, "config %s, bad hs length or type\n",
 793                                         data->name);
 794                         goto fail0;
 795                 }
 796         }
 797         value = len;
 798
 799         spin_lock_irq (&data->dev->lock);
 800         if (data->dev->state == STATE_DEV_UNBOUND) {
 801                 value = -ENOENT;
 802                 goto gone;
 803         } else if ((ep = data->ep) == NULL) {
 804                 value = -ENODEV;
 805                 goto gone;
 806         }
 807         switch (data->dev->gadget->speed) {
 808         case USB_SPEED_LOW:
 809         case USB_SPEED_FULL:
 810                 value = usb_ep_enable (ep, &data->desc);
 811                 if (value == 0)
 812                         data->state = STATE_EP_ENABLED;
 813                 break;
 814 #ifdef  HIGHSPEED
 815         case USB_SPEED_HIGH:
 816                 /* fails if caller didn't provide that descriptor... */
 817                 value = usb_ep_enable (ep, &data->hs_desc);
 818                 if (value == 0)
 819                         data->state = STATE_EP_ENABLED;
 820                 break;
 821 #endif
 822         default:
 823                 DBG (data->dev, "unconnected, %s init deferred\n",
 824                                 data->name);
 825                 data->state = STATE_EP_DEFER_ENABLE;
 826         }
 827         if (value == 0)
 828                 fd->f_op = &ep_io_operations;
 829 gone:
 830         spin_unlock_irq (&data->dev->lock);
 831         if (value < 0) {
 832 fail:
 833                 data->desc.bDescriptorType = 0;
 834                 data->hs_desc.bDescriptorType = 0;
 835         }
 836         up (&data->lock);
 837         return value;
 838 fail0:
 839         value = -EINVAL;
 840         goto fail;
 841 fail1:
 842         value = -EFAULT;
 843         goto fail;
 844 }
 845
 846 static int
 847 ep_open (struct inode *inode, struct file *fd)
 848 {
 849         struct ep_data          *data = inode->u.generic_ip;
 850         int                     value = -EBUSY;
 851
 852         if (down_interruptible (&data->lock) != 0)
 853                 return -EINTR;
 854         spin_lock_irq (&data->dev->lock);
 855         if (data->dev->state == STATE_DEV_UNBOUND)
 856                 value = -ENOENT;
 857         else if (data->state == STATE_EP_DISABLED) {
 858                 value = 0;
 859                 data->state = STATE_EP_READY;
 860                 get_ep (data);
 861                 fd->private_data = data;
 862                 VDEBUG (data->dev, "%s ready\n", data->name);
 863         } else
 864                 DBG (data->dev, "%s state %d\n",
 865                         data->name, data->state);
 866         spin_unlock_irq (&data->dev->lock);
 867         up (&data->lock);
 868         return value;
 869 }
 870
 871 /* used before endpoint configuration */
 872 static struct file_operations ep_config_operations = {
 873         .owner =        THIS_MODULE,
 874         .llseek =       no_llseek,
 875
 876         .open =         ep_open,
 877         .write =        ep_config,
 878         .release =      ep_release,
 879 };
 880
 881 /*----------------------------------------------------------------------*/
 882
 883 /* EP0 IMPLEMENTATION can be partly in userspace.
 884  *
 885  * Drivers that use this facility receive various events, including
 886  * control requests the kernel doesn't handle.  Drivers that don't
 887  * use this facility may be too simple-minded for real applications.
 888  */
 889
 890 static inline void ep0_readable (struct dev_data *dev)
 891 {
 892         wake_up (&dev->wait);
 893         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 894 }
 895
 896 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 897 {
 898         struct dev_data         *dev = ep->driver_data;
 899
 900         if (req->buf != dev->rbuf) {
 901                 usb_ep_free_buffer (ep, req->buf, req->dma, req->length);
 902                 req->buf = dev->rbuf;
 903                 req->dma = DMA_ADDR_INVALID;
 904         }
 905         req->complete = epio_complete;
 906         dev->setup_out_ready = 0;
 907 }
 908
 909 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 910 {
 911         struct dev_data         *dev = ep->driver_data;
 912         int                     free = 1;
 913
 914         /* for control OUT, data must still get to userspace */
 915         if (!dev->setup_in) {
 916                 dev->setup_out_error = (req->status != 0);
 917                 if (!dev->setup_out_error)
 918                         free = 0;
 919                 dev->setup_out_ready = 1;
 920                 ep0_readable (dev);
 921         } else if (dev->state == STATE_SETUP)
 922                 dev->state = STATE_CONNECTED;
 923
 924         /* clean up as appropriate */
 925         if (free && req->buf != &dev->rbuf)
 926                 clean_req (ep, req);
 927         req->complete = epio_complete;
 928 }
 929
 930 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 931 {
 932         struct dev_data *dev = ep->driver_data;
 933
 934         if (dev->setup_out_ready) {
 935                 DBG (dev, "ep0 request busy!\n");
 936                 return -EBUSY;
 937         }
 938         if (len > sizeof (dev->rbuf))
 939                 req->buf = usb_ep_alloc_buffer (ep, len, &req->dma, GFP_ATOMIC);
 940         if (req->buf == 0) {
 941                 req->buf = dev->rbuf;
 942                 return -ENOMEM;
 943         }
 944         req->complete = ep0_complete;
 945         req->length = len;
 946         req->zero = 0;
 947         return 0;
 948 }
 949
 950 static ssize_t
 951 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 952 {
 953         struct dev_data                 *dev = fd->private_data;
 954         ssize_t                         retval;
 955         enum ep0_state                  state;
 956
 957         spin_lock_irq (&dev->lock);
 958
 959         /* report fd mode change before acting on it */
 960         if (dev->setup_abort) {
 961                 dev->setup_abort = 0;
 962                 retval = -EIDRM;
 963                 goto done;
 964         }
 965
 966         /* control DATA stage */
 967         if ((state = dev->state) == STATE_SETUP) {
 968
 969                 if (dev->setup_in) {            /* stall IN */
 970                         VDEBUG(dev, "ep0in stall\n");
 971                         (void) usb_ep_set_halt (dev->gadget->ep0);
 972                         retval = -EL2HLT;
 973                         dev->state = STATE_CONNECTED;
 974
 975                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
 976                         struct usb_ep           *ep = dev->gadget->ep0;
 977                         struct usb_request      *req = dev->req;
 978
 979                         if ((retval = setup_req (ep, req, 0)) == 0)
 980                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
 981                         dev->state = STATE_CONNECTED;
 982
 983                         /* assume that was SET_CONFIGURATION */
 984                         if (dev->current_config) {
 985                                 unsigned power;
 986 #ifdef  HIGHSPEED
 987                                 if (dev->gadget->speed == USB_SPEED_HIGH)
 988                                         power = dev->hs_config->bMaxPower;
 989                                 else
 990 #endif
 991                                         power = dev->config->bMaxPower;
 992                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
 993                         }
 994
 995                 } else {                        /* collect OUT data */
 996                         if ((fd->f_flags & O_NONBLOCK) != 0
 997                                         && !dev->setup_out_ready) {
 998                                 retval = -EAGAIN;
 999                                 goto done;
1000                         }
1001                         spin_unlock_irq (&dev->lock);
1002                         retval = wait_event_interruptible (dev->wait,
1003                                         dev->setup_out_ready != 0);
1004
1005                         /* FIXME state could change from under us */
1006                         spin_lock_irq (&dev->lock);
1007                         if (retval)
1008                                 goto done;
1009                         if (dev->setup_out_error)
1010                                 retval = -EIO;
1011                         else {
1012                                 len = min (len, (size_t)dev->req->actual);
1013 // FIXME don't call this with the spinlock held ...
1014                                 if (copy_to_user (buf, &dev->req->buf, len))
1015                                         retval = -EFAULT;
1016                                 clean_req (dev->gadget->ep0, dev->req);
1017                                 /* NOTE userspace can't yet choose to stall */
1018                         }
1019                 }
1020                 goto done;
1021         }
1022
1023         /* else normal: return event data */
1024         if (len < sizeof dev->event [0]) {
1025                 retval = -EINVAL;
1026                 goto done;
1027         }
1028         len -= len % sizeof (struct usb_gadgetfs_event);
1029         dev->usermode_setup = 1;
1030
1031 scan:
1032         /* return queued events right away */
1033         if (dev->ev_next != 0) {
1034                 unsigned                i, n;
1035                 int                     tmp = dev->ev_next;
1036
1037                 len = min (len, tmp * sizeof (struct usb_gadgetfs_event));
1038                 n = len / sizeof (struct usb_gadgetfs_event);
1039
1040                 /* ep0 can't deliver events when STATE_SETUP */
1041                 for (i = 0; i < n; i++) {
1042                         if (dev->event [i].type == GADGETFS_SETUP) {
1043                                 len = n = i + 1;
1044                                 len *= sizeof (struct usb_gadgetfs_event);
1045                                 n = 0;
1046                                 break;
1047                         }
1048                 }
1049                 spin_unlock_irq (&dev->lock);
1050                 if (copy_to_user (buf, &dev->event, len))
1051                         retval = -EFAULT;
1052                 else
1053                         retval = len;
1054                 if (len > 0) {
1055                         len /= sizeof (struct usb_gadgetfs_event);
1056
1057                         /* NOTE this doesn't guard against broken drivers;
1058                          * concurrent ep0 readers may lose events.
1059                          */
1060                         spin_lock_irq (&dev->lock);
1061                         dev->ev_next -= len;
1062                         if (dev->ev_next != 0)
1063                                 memmove (&dev->event, &dev->event [len],
1064                                         sizeof (struct usb_gadgetfs_event)
1065                                                 * (tmp - len));
1066                         if (n == 0)
1067                                 dev->state = STATE_SETUP;
1068                         spin_unlock_irq (&dev->lock);
1069                 }
1070                 return retval;
1071         }
1072         if (fd->f_flags & O_NONBLOCK) {
1073                 retval = -EAGAIN;
1074                 goto done;
1075         }
1076
1077         switch (state) {
1078         default:
1079                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, state);
1080                 retval = -ESRCH;
1081                 break;
1082         case STATE_UNCONNECTED:
1083         case STATE_CONNECTED:
1084                 spin_unlock_irq (&dev->lock);
1085                 DBG (dev, "%s wait\n", __FUNCTION__);
1086
1087                 /* wait for events */
1088                 retval = wait_event_interruptible (dev->wait,
1089                                 dev->ev_next != 0);
1090                 if (retval < 0)
1091                         return retval;
1092                 spin_lock_irq (&dev->lock);
1093                 goto scan;
1094         }
1095
1096 done:
1097         spin_unlock_irq (&dev->lock);
1098         return retval;
1099 }
1100
1101 static struct usb_gadgetfs_event *
1102 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1103 {
1104         struct usb_gadgetfs_event       *event;
1105         unsigned                        i;
1106
1107         switch (type) {
1108         /* these events purge the queue */
1109         case GADGETFS_DISCONNECT:
1110                 if (dev->state == STATE_SETUP)
1111                         dev->setup_abort = 1;
1112                 // FALL THROUGH
1113         case GADGETFS_CONNECT:
1114                 dev->ev_next = 0;
1115                 break;
1116         case GADGETFS_SETUP:            /* previous request timed out */
1117         case GADGETFS_SUSPEND:          /* same effect */
1118                 /* these events can't be repeated */
1119                 for (i = 0; i != dev->ev_next; i++) {
1120                         if (dev->event [i].type != type)
1121                                 continue;
1122                         DBG (dev, "discard old event %d\n", type);
1123                         dev->ev_next--;
1124                         if (i == dev->ev_next)
1125                                 break;
1126                         /* indices start at zero, for simplicity */
1127                         memmove (&dev->event [i], &dev->event [i + 1],
1128                                 sizeof (struct usb_gadgetfs_event)
1129                                         * (dev->ev_next - i));
1130                 }
1131                 break;
1132         default:
1133                 BUG ();
1134         }
1135         event = &dev->event [dev->ev_next++];
1136         BUG_ON (dev->ev_next > N_EVENT);
1137         VDEBUG (dev, "ev %d, next %d\n", type, dev->ev_next);
1138         memset (event, 0, sizeof *event);
1139         event->type = type;
1140         return event;
1141 }
1142
1143 static ssize_t
1144 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1145 {
1146         struct dev_data         *dev = fd->private_data;
1147         ssize_t                 retval = -ESRCH;
1148
1149         spin_lock_irq (&dev->lock);
1150
1151         /* report fd mode change before acting on it */
1152         if (dev->setup_abort) {
1153                 dev->setup_abort = 0;
1154                 retval = -EIDRM;
1155
1156         /* data and/or status stage for control request */
1157         } else if (dev->state == STATE_SETUP) {
1158
1159                 /* IN DATA+STATUS caller makes len <= wLength */
1160                 if (dev->setup_in) {
1161                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1162                         if (retval == 0) {
1163                                 spin_unlock_irq (&dev->lock);
1164                                 if (copy_from_user (dev->req->buf, buf, len))
1165                                         retval = -EFAULT;
1166                                 else {
1167                                         if (len < dev->setup_wLength)
1168                                                 dev->req->zero = 1;
1169                                         retval = usb_ep_queue (
1170                                                 dev->gadget->ep0, dev->req,
1171                                                 GFP_KERNEL);
1172                                 }
1173                                 if (retval < 0) {
1174                                         spin_lock_irq (&dev->lock);
1175                                         clean_req (dev->gadget->ep0, dev->req);
1176                                         spin_unlock_irq (&dev->lock);
1177                                 } else
1178                                         retval = len;
1179
1180                                 return retval;
1181                         }
1182
1183                 /* can stall some OUT transfers */
1184                 } else if (dev->setup_can_stall) {
1185                         VDEBUG(dev, "ep0out stall\n");
1186                         (void) usb_ep_set_halt (dev->gadget->ep0);
1187                         retval = -EL2HLT;
1188                         dev->state = STATE_CONNECTED;
1189                 } else {
1190                         DBG(dev, "bogus ep0out stall!\n");
1191                 }
1192         } else
1193                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state);
1194
1195         spin_unlock_irq (&dev->lock);
1196         return retval;
1197 }
1198
1199 static int
1200 ep0_fasync (int f, struct file *fd, int on)
1201 {
1202         struct dev_data         *dev = fd->private_data;
1203         // caller must F_SETOWN before signal delivery happens
1204         VDEBUG (dev, "%s %s\n", __FUNCTION__, on ? "on" : "off");
1205         return fasync_helper (f, fd, on, &dev->fasync);
1206 }
1207
1208 static struct usb_gadget_driver gadgetfs_driver;
1209
1210 static int
1211 dev_release (struct inode *inode, struct file *fd)
1212 {
1213         struct dev_data         *dev = fd->private_data;
1214
1215         /* closing ep0 === shutdown all */
1216
1217         usb_gadget_unregister_driver (&gadgetfs_driver);
1218
1219         /* at this point "good" hardware has disconnected the
1220          * device from USB; the host won't see it any more.
1221          * alternatively, all host requests will time out.
1222          */
1223
1224         fasync_helper (-1, fd, 0, &dev->fasync);
1225         kfree (dev->buf);
1226         dev->buf = NULL;
1227         put_dev (dev);
1228
1229         /* other endpoints were all decoupled from this device */
1230         dev->state = STATE_DEV_DISABLED;
1231         return 0;
1232 }
1233
1234 static int dev_ioctl (struct inode *inode, struct file *fd,
1235                 unsigned code, unsigned long value)
1236 {
1237         struct dev_data         *dev = fd->private_data;
1238         struct usb_gadget       *gadget = dev->gadget;
1239
1240         if (gadget->ops->ioctl)
1241                 return gadget->ops->ioctl (gadget, code, value);
1242         return -ENOTTY;
1243 }
1244
1245 /* used after device configuration */
1246 static struct file_operations ep0_io_operations = {
1247         .owner =        THIS_MODULE,
1248         .llseek =       no_llseek,
1249
1250         .read =         ep0_read,
1251         .write =        ep0_write,
1252         .fasync =       ep0_fasync,
1253         // .poll =      ep0_poll,
1254         .ioctl =        dev_ioctl,
1255         .release =      dev_release,
1256 };
1257
1258 /*----------------------------------------------------------------------*/
1259
1260 /* The in-kernel gadget driver handles most ep0 issues, in particular
1261  * enumerating the single configuration (as provided from user space).
1262  *
1263  * Unrecognized ep0 requests may be handled in user space.
1264  */
1265
1266 #ifdef  HIGHSPEED
1267 static void make_qualifier (struct dev_data *dev)
1268 {
1269         struct usb_qualifier_descriptor         qual;
1270         struct usb_device_descriptor            *desc;
1271
1272         qual.bLength = sizeof qual;
1273         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1274         qual.bcdUSB = __constant_cpu_to_le16 (0x0200);
1275
1276         desc = dev->dev;
1277         qual.bDeviceClass = desc->bDeviceClass;
1278         qual.bDeviceSubClass = desc->bDeviceSubClass;
1279         qual.bDeviceProtocol = desc->bDeviceProtocol;
1280
1281         /* assumes ep0 uses the same value for both speeds ... */
1282         qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
1283
1284         qual.bNumConfigurations = 1;
1285         qual.bRESERVED = 0;
1286
1287         memcpy (dev->rbuf, &qual, sizeof qual);
1288 }
1289 #endif
1290
1291 static int
1292 config_buf (struct dev_data *dev, u8 type, unsigned index)
1293 {
1294         int             len;
1295 #ifdef HIGHSPEED
1296         int             hs;
1297 #endif
1298
1299         /* only one configuration */
1300         if (index > 0)
1301                 return -EINVAL;
1302
1303 #ifdef HIGHSPEED
1304         hs = (dev->gadget->speed == USB_SPEED_HIGH);
1305         if (type == USB_DT_OTHER_SPEED_CONFIG)
1306                 hs = !hs;
1307         if (hs) {
1308                 dev->req->buf = dev->hs_config;
1309                 len = le16_to_cpup (&dev->hs_config->wTotalLength);
1310         } else
1311 #endif
1312         {
1313                 dev->req->buf = dev->config;
1314                 len = le16_to_cpup (&dev->config->wTotalLength);
1315         }
1316         ((u8 *)dev->req->buf) [1] = type;
1317         return len;
1318 }
1319
1320 static int
1321 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1322 {
1323         struct dev_data                 *dev = get_gadget_data (gadget);
1324         struct usb_request              *req = dev->req;
1325         int                             value = -EOPNOTSUPP;
1326         struct usb_gadgetfs_event       *event;
1327         u16                             w_value = le16_to_cpu(ctrl->wValue);
1328         u16                             w_length = le16_to_cpu(ctrl->wLength);
1329
1330         spin_lock (&dev->lock);
1331         dev->setup_abort = 0;
1332         if (dev->state == STATE_UNCONNECTED) {
1333                 struct usb_ep   *ep;
1334                 struct ep_data  *data;
1335
1336                 dev->state = STATE_CONNECTED;
1337                 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1338
1339 #ifdef  HIGHSPEED
1340                 if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) {
1341                         ERROR (dev, "no high speed config??\n");
1342                         return -EINVAL;
1343                 }
1344 #endif  /* HIGHSPEED */
1345
1346                 INFO (dev, "connected\n");
1347                 event = next_event (dev, GADGETFS_CONNECT);
1348                 event->u.speed = gadget->speed;
1349                 ep0_readable (dev);
1350
1351                 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
1352                         data = ep->driver_data;
1353                         /* ... down_trylock (&data->lock) ... */
1354                         if (data->state != STATE_EP_DEFER_ENABLE)
1355                                 continue;
1356 #ifdef  HIGHSPEED
1357                         if (gadget->speed == USB_SPEED_HIGH)
1358                                 value = usb_ep_enable (ep, &data->hs_desc);
1359                         else
1360 #endif  /* HIGHSPEED */
1361                                 value = usb_ep_enable (ep, &data->desc);
1362                         if (value) {
1363                                 ERROR (dev, "deferred %s enable --> %d\n",
1364                                         data->name, value);
1365                                 continue;
1366                         }
1367                         data->state = STATE_EP_ENABLED;
1368                         wake_up (&data->wait);
1369                         DBG (dev, "woke up %s waiters\n", data->name);
1370                 }
1371
1372         /* host may have given up waiting for response.  we can miss control
1373          * requests handled lower down (device/endpoint status and features);
1374          * then ep0_{read,write} will report the wrong status. controller
1375          * driver will have aborted pending i/o.
1376          */
1377         } else if (dev->state == STATE_SETUP)
1378                 dev->setup_abort = 1;
1379
1380         req->buf = dev->rbuf;
1381         req->dma = DMA_ADDR_INVALID;
1382         req->context = NULL;
1383         value = -EOPNOTSUPP;
1384         switch (ctrl->bRequest) {
1385
1386         case USB_REQ_GET_DESCRIPTOR:
1387                 if (ctrl->bRequestType != USB_DIR_IN)
1388                         goto unrecognized;
1389                 switch (w_value >> 8) {
1390
1391                 case USB_DT_DEVICE:
1392                         value = min (w_length, (u16) sizeof *dev->dev);
1393                         req->buf = dev->dev;
1394                         break;
1395 #ifdef  HIGHSPEED
1396                 case USB_DT_DEVICE_QUALIFIER:
1397                         if (!dev->hs_config)
1398                                 break;
1399                         value = min (w_length, (u16)
1400                                 sizeof (struct usb_qualifier_descriptor));
1401                         make_qualifier (dev);
1402                         break;
1403                 case USB_DT_OTHER_SPEED_CONFIG:
1404                         // FALLTHROUGH
1405 #endif
1406                 case USB_DT_CONFIG:
1407                         value = config_buf (dev,
1408                                         w_value >> 8,
1409                                         w_value & 0xff);
1410                         if (value >= 0)
1411                                 value = min (w_length, (u16) value);
1412                         break;
1413                 case USB_DT_STRING:
1414                         goto unrecognized;
1415
1416                 default:                // all others are errors
1417                         break;
1418                 }
1419                 break;
1420
1421         /* currently one config, two speeds */
1422         case USB_REQ_SET_CONFIGURATION:
1423                 if (ctrl->bRequestType != 0)
1424                         break;
1425                 if (0 == (u8) w_value) {
1426                         value = 0;
1427                         dev->current_config = 0;
1428                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1429                         // user mode expected to disable endpoints
1430                 } else {
1431                         u8      config, power;
1432 #ifdef  HIGHSPEED
1433                         if (gadget->speed == USB_SPEED_HIGH) {
1434                                 config = dev->hs_config->bConfigurationValue;
1435                                 power = dev->hs_config->bMaxPower;
1436                         } else
1437 #endif
1438                         {
1439                                 config = dev->config->bConfigurationValue;
1440                                 power = dev->config->bMaxPower;
1441                         }
1442
1443                         if (config == (u8) w_value) {
1444                                 value = 0;
1445                                 dev->current_config = config;
1446                                 usb_gadget_vbus_draw(gadget, 2 * power);
1447                         }
1448                 }
1449
1450                 /* report SET_CONFIGURATION like any other control request,
1451                  * except that usermode may not stall this.  the next
1452                  * request mustn't be allowed start until this finishes:
1453                  * endpoints and threads set up, etc.
1454                  *
1455                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1456                  * has bad/racey automagic that prevents synchronizing here.
1457                  * even kernel mode drivers often miss them.
1458                  */
1459                 if (value == 0) {
1460                         INFO (dev, "configuration #%d\n", dev->current_config);
1461                         if (dev->usermode_setup) {
1462                                 dev->setup_can_stall = 0;
1463                                 goto delegate;
1464                         }
1465                 }
1466                 break;
1467
1468 #ifndef CONFIG_USB_GADGETFS_PXA2XX
1469         /* PXA automagically handles this request too */
1470         case USB_REQ_GET_CONFIGURATION:
1471                 if (ctrl->bRequestType != 0x80)
1472                         break;
1473                 *(u8 *)req->buf = dev->current_config;
1474                 value = min (w_length, (u16) 1);
1475                 break;
1476 #endif
1477
1478         default:
1479 unrecognized:
1480                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1481                         dev->usermode_setup ? "delegate" : "fail",
1482                         ctrl->bRequestType, ctrl->bRequest,
1483                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1484
1485                 /* if there's an ep0 reader, don't stall */
1486                 if (dev->usermode_setup) {
1487                         dev->setup_can_stall = 1;
1488 delegate:
1489                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1490                                                 ? 1 : 0;
1491                         dev->setup_wLength = w_length;
1492                         dev->setup_out_ready = 0;
1493                         dev->setup_out_error = 0;
1494                         value = 0;
1495
1496                         /* read DATA stage for OUT right away */
1497                         if (unlikely (!dev->setup_in && w_length)) {
1498                                 value = setup_req (gadget->ep0, dev->req,
1499                                                         w_length);
1500                                 if (value < 0)
1501                                         break;
1502                                 value = usb_ep_queue (gadget->ep0, dev->req,
1503                                                         GFP_ATOMIC);
1504                                 if (value < 0) {
1505                                         clean_req (gadget->ep0, dev->req);
1506                                         break;
1507                                 }
1508
1509                                 /* we can't currently stall these */
1510                                 dev->setup_can_stall = 0;
1511                         }
1512
1513                         /* state changes when reader collects event */
1514                         event = next_event (dev, GADGETFS_SETUP);
1515                         event->u.setup = *ctrl;
1516                         ep0_readable (dev);
1517                         spin_unlock (&dev->lock);
1518                         return 0;
1519                 }
1520         }
1521
1522         /* proceed with data transfer and status phases? */
1523         if (value >= 0 && dev->state != STATE_SETUP) {
1524                 req->length = value;
1525                 req->zero = value < w_length;
1526                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1527                 if (value < 0) {
1528                         DBG (dev, "ep_queue --> %d\n", value);
1529                         req->status = 0;
1530                 }
1531         }
1532
1533         /* device stalls when value < 0 */
1534         spin_unlock (&dev->lock);
1535         return value;
1536 }
1537
1538 static void destroy_ep_files (struct dev_data *dev)
1539 {
1540         struct list_head        *entry, *tmp;
1541
1542         DBG (dev, "%s %d\n", __FUNCTION__, dev->state);
1543
1544         /* dev->state must prevent interference */
1545 restart:
1546         spin_lock_irq (&dev->lock);
1547         list_for_each_safe (entry, tmp, &dev->epfiles) {
1548                 struct ep_data  *ep;
1549                 struct inode    *parent;
1550                 struct dentry   *dentry;
1551
1552                 /* break link to FS */
1553                 ep = list_entry (entry, struct ep_data, epfiles);
1554                 list_del_init (&ep->epfiles);
1555                 dentry = ep->dentry;
1556                 ep->dentry = NULL;
1557                 parent = dentry->d_parent->d_inode;
1558
1559                 /* break link to controller */
1560                 if (ep->state == STATE_EP_ENABLED)
1561                         (void) usb_ep_disable (ep->ep);
1562                 ep->state = STATE_EP_UNBOUND;
1563                 usb_ep_free_request (ep->ep, ep->req);
1564                 ep->ep = NULL;
1565                 wake_up (&ep->wait);
1566                 put_ep (ep);
1567
1568                 spin_unlock_irq (&dev->lock);
1569
1570                 /* break link to dcache */
1571                 mutex_lock (&parent->i_mutex);
1572                 d_delete (dentry);
1573                 dput (dentry);
1574                 mutex_unlock (&parent->i_mutex);
1575
1576                 /* fds may still be open */
1577                 goto restart;
1578         }
1579         spin_unlock_irq (&dev->lock);
1580 }
1581
1582
1583 static struct inode *
1584 gadgetfs_create_file (struct super_block *sb, char const *name,
1585                 void *data, struct file_operations *fops,
1586                 struct dentry **dentry_p);
1587
1588 static int activate_ep_files (struct dev_data *dev)
1589 {
1590         struct usb_ep   *ep;
1591
1592         gadget_for_each_ep (ep, dev->gadget) {
1593                 struct ep_data  *data;
1594
1595                 data = kmalloc (sizeof *data, GFP_KERNEL);
1596                 if (!data)
1597                         goto enomem;
1598                 memset (data, 0, sizeof data);
1599                 data->state = STATE_EP_DISABLED;
1600                 init_MUTEX (&data->lock);
1601                 init_waitqueue_head (&data->wait);
1602
1603                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1604                 atomic_set (&data->count, 1);
1605                 data->dev = dev;
1606                 get_dev (dev);
1607
1608                 data->ep = ep;
1609                 ep->driver_data = data;
1610
1611                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1612                 if (!data->req)
1613                         goto enomem;
1614
1615                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1616                                 data, &ep_config_operations,
1617                                 &data->dentry);
1618                 if (!data->inode) {
1619                         kfree (data);
1620                         goto enomem;
1621                 }
1622                 list_add_tail (&data->epfiles, &dev->epfiles);
1623         }
1624         return 0;
1625
1626 enomem:
1627         DBG (dev, "%s enomem\n", __FUNCTION__);
1628         destroy_ep_files (dev);
1629         return -ENOMEM;
1630 }
1631
1632 static void
1633 gadgetfs_unbind (struct usb_gadget *gadget)
1634 {
1635         struct dev_data         *dev = get_gadget_data (gadget);
1636
1637         DBG (dev, "%s\n", __FUNCTION__);
1638
1639         spin_lock_irq (&dev->lock);
1640         dev->state = STATE_DEV_UNBOUND;
1641         spin_unlock_irq (&dev->lock);
1642
1643         destroy_ep_files (dev);
1644         gadget->ep0->driver_data = NULL;
1645         set_gadget_data (gadget, NULL);
1646
1647         /* we've already been disconnected ... no i/o is active */
1648         if (dev->req)
1649                 usb_ep_free_request (gadget->ep0, dev->req);
1650         DBG (dev, "%s done\n", __FUNCTION__);
1651         put_dev (dev);
1652 }
1653
1654 static struct dev_data          *the_device;
1655
1656 static int
1657 gadgetfs_bind (struct usb_gadget *gadget)
1658 {
1659         struct dev_data         *dev = the_device;
1660
1661         if (!dev)
1662                 return -ESRCH;
1663         if (0 != strcmp (CHIP, gadget->name)) {
1664                 printk (KERN_ERR "%s expected %s controller not %s\n",
1665                         shortname, CHIP, gadget->name);
1666                 return -ENODEV;
1667         }
1668
1669         set_gadget_data (gadget, dev);
1670         dev->gadget = gadget;
1671         gadget->ep0->driver_data = dev;
1672         dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1673
1674         /* preallocate control response and buffer */
1675         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1676         if (!dev->req)
1677                 goto enomem;
1678         dev->req->context = NULL;
1679         dev->req->complete = epio_complete;
1680
1681         if (activate_ep_files (dev) < 0)
1682                 goto enomem;
1683
1684         INFO (dev, "bound to %s driver\n", gadget->name);
1685         dev->state = STATE_UNCONNECTED;
1686         get_dev (dev);
1687         return 0;
1688
1689 enomem:
1690         gadgetfs_unbind (gadget);
1691         return -ENOMEM;
1692 }
1693
1694 static void
1695 gadgetfs_disconnect (struct usb_gadget *gadget)
1696 {
1697         struct dev_data         *dev = get_gadget_data (gadget);
1698
1699         if (dev->state == STATE_UNCONNECTED) {
1700                 DBG (dev, "already unconnected\n");
1701                 return;
1702         }
1703         dev->state = STATE_UNCONNECTED;
1704
1705         INFO (dev, "disconnected\n");
1706         spin_lock (&dev->lock);
1707         next_event (dev, GADGETFS_DISCONNECT);
1708         ep0_readable (dev);
1709         spin_unlock (&dev->lock);
1710 }
1711
1712 static void
1713 gadgetfs_suspend (struct usb_gadget *gadget)
1714 {
1715         struct dev_data         *dev = get_gadget_data (gadget);
1716
1717         INFO (dev, "suspended from state %d\n", dev->state);
1718         spin_lock (&dev->lock);
1719         switch (dev->state) {
1720         case STATE_SETUP:               // VERY odd... host died??
1721         case STATE_CONNECTED:
1722         case STATE_UNCONNECTED:
1723                 next_event (dev, GADGETFS_SUSPEND);
1724                 ep0_readable (dev);
1725                 /* FALLTHROUGH */
1726         default:
1727                 break;
1728         }
1729         spin_unlock (&dev->lock);
1730 }
1731
1732 static struct usb_gadget_driver gadgetfs_driver = {
1733 #ifdef  HIGHSPEED
1734         .speed          = USB_SPEED_HIGH,
1735 #else
1736         .speed          = USB_SPEED_FULL,
1737 #endif
1738         .function       = (char *) driver_desc,
1739         .bind           = gadgetfs_bind,
1740         .unbind         = gadgetfs_unbind,
1741         .setup          = gadgetfs_setup,
1742         .disconnect     = gadgetfs_disconnect,
1743         .suspend        = gadgetfs_suspend,
1744
1745         .driver         = {
1746                 .name           = (char *) shortname,
1747         },
1748 };
1749
1750 /*----------------------------------------------------------------------*/
1751
1752 static void gadgetfs_nop(struct usb_gadget *arg) { }
1753
1754 static int gadgetfs_probe (struct usb_gadget *gadget)
1755 {
1756         CHIP = gadget->name;
1757         return -EISNAM;
1758 }
1759
1760 static struct usb_gadget_driver probe_driver = {
1761         .speed          = USB_SPEED_HIGH,
1762         .bind           = gadgetfs_probe,
1763         .unbind         = gadgetfs_nop,
1764         .setup          = (void *)gadgetfs_nop,
1765         .disconnect     = gadgetfs_nop,
1766         .driver         = {
1767                 .name           = "nop",
1768         },
1769 };
1770
1771
1772 /* DEVICE INITIALIZATION
1773  *
1774  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1775  *     status = write (fd, descriptors, sizeof descriptors)
1776  *
1777  * That write establishes the device configuration, so the kernel can
1778  * bind to the controller ... guaranteeing it can handle enumeration
1779  * at all necessary speeds.  Descriptor order is:
1780  *
1781  * . message tag (u32, host order) ... for now, must be zero; it
1782  *      would change to support features like multi-config devices
1783  * . full/low speed config ... all wTotalLength bytes (with interface,
1784  *      class, altsetting, endpoint, and other descriptors)
1785  * . high speed config ... all descriptors, for high speed operation;
1786  *      this one's optional except for high-speed hardware
1787  * . device descriptor
1788  *
1789  * Endpoints are not yet enabled. Drivers may want to immediately
1790  * initialize them, using the /dev/gadget/ep* files that are available
1791  * as soon as the kernel sees the configuration, or they can wait
1792  * until device configuration and interface altsetting changes create
1793  * the need to configure (or unconfigure) them.
1794  *
1795  * After initialization, the device stays active for as long as that
1796  * $CHIP file is open.  Events may then be read from that descriptor,
1797  * such configuration notifications.  More complex drivers will handle
1798  * some control requests in user space.
1799  */
1800
1801 static int is_valid_config (struct usb_config_descriptor *config)
1802 {
1803         return config->bDescriptorType == USB_DT_CONFIG
1804                 && config->bLength == USB_DT_CONFIG_SIZE
1805                 && config->bConfigurationValue != 0
1806                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1807                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1808         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1809         /* FIXME check lengths: walk to end */
1810 }
1811
1812 static ssize_t
1813 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1814 {
1815         struct dev_data         *dev = fd->private_data;
1816         ssize_t                 value = len, length = len;
1817         unsigned                total;
1818         u32                     tag;
1819         char                    *kbuf;
1820
1821         if (dev->state != STATE_OPENED)
1822                 return -EEXIST;
1823
1824         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1825                 return -EINVAL;
1826
1827         /* we might need to change message format someday */
1828         if (copy_from_user (&tag, buf, 4))
1829                 return -EFAULT;
1830         if (tag != 0)
1831                 return -EINVAL;
1832         buf += 4;
1833         length -= 4;
1834
1835         kbuf = kmalloc (length, SLAB_KERNEL);
1836         if (!kbuf)
1837                 return -ENOMEM;
1838         if (copy_from_user (kbuf, buf, length)) {
1839                 kfree (kbuf);
1840                 return -EFAULT;
1841         }
1842
1843         spin_lock_irq (&dev->lock);
1844         value = -EINVAL;
1845         if (dev->buf)
1846                 goto fail;
1847         dev->buf = kbuf;
1848
1849         /* full or low speed config */
1850         dev->config = (void *) kbuf;
1851         total = le16_to_cpup (&dev->config->wTotalLength);
1852         if (!is_valid_config (dev->config) || total >= length)
1853                 goto fail;
1854         kbuf += total;
1855         length -= total;
1856
1857         /* optional high speed config */
1858         if (kbuf [1] == USB_DT_CONFIG) {
1859                 dev->hs_config = (void *) kbuf;
1860                 total = le16_to_cpup (&dev->hs_config->wTotalLength);
1861                 if (!is_valid_config (dev->hs_config) || total >= length)
1862                         goto fail;
1863                 kbuf += total;
1864                 length -= total;
1865         }
1866
1867         /* could support multiple configs, using another encoding! */
1868
1869         /* device descriptor (tweaked for paranoia) */
1870         if (length != USB_DT_DEVICE_SIZE)
1871                 goto fail;
1872         dev->dev = (void *)kbuf;
1873         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1874                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1875                         || dev->dev->bNumConfigurations != 1)
1876                 goto fail;
1877         dev->dev->bNumConfigurations = 1;
1878         dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200);
1879
1880         /* triggers gadgetfs_bind(); then we can enumerate. */
1881         spin_unlock_irq (&dev->lock);
1882         value = usb_gadget_register_driver (&gadgetfs_driver);
1883         if (value != 0) {
1884                 kfree (dev->buf);
1885                 dev->buf = NULL;
1886         } else {
1887                 /* at this point "good" hardware has for the first time
1888                  * let the USB the host see us.  alternatively, if users
1889                  * unplug/replug that will clear all the error state.
1890                  *
1891                  * note:  everything running before here was guaranteed
1892                  * to choke driver model style diagnostics.  from here
1893                  * on, they can work ... except in cleanup paths that
1894                  * kick in after the ep0 descriptor is closed.
1895                  */
1896                 fd->f_op = &ep0_io_operations;
1897                 value = len;
1898         }
1899         return value;
1900
1901 fail:
1902         spin_unlock_irq (&dev->lock);
1903         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __FUNCTION__, value, dev);
1904         kfree (dev->buf);
1905         dev->buf = NULL;
1906         return value;
1907 }
1908
1909 static int
1910 dev_open (struct inode *inode, struct file *fd)
1911 {
1912         struct dev_data         *dev = inode->u.generic_ip;
1913         int                     value = -EBUSY;
1914
1915         if (dev->state == STATE_DEV_DISABLED) {
1916                 dev->ev_next = 0;
1917                 dev->state = STATE_OPENED;
1918                 fd->private_data = dev;
1919                 get_dev (dev);
1920                 value = 0;
1921         }
1922         return value;
1923 }
1924
1925 static struct file_operations dev_init_operations = {
1926         .owner =        THIS_MODULE,
1927         .llseek =       no_llseek,
1928
1929         .open =         dev_open,
1930         .write =        dev_config,
1931         .fasync =       ep0_fasync,
1932         .ioctl =        dev_ioctl,
1933         .release =      dev_release,
1934 };
1935
1936 /*----------------------------------------------------------------------*/
1937
1938 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1939  *
1940  * Mounting the filesystem creates a controller file, used first for
1941  * device configuration then later for event monitoring.
1942  */
1943
1944
1945 /* FIXME PAM etc could set this security policy without mount options
1946  * if epfiles inherited ownership and permissons from ep0 ...
1947  */
1948
1949 static unsigned default_uid;
1950 static unsigned default_gid;
1951 static unsigned default_perm = S_IRUSR | S_IWUSR;
1952
1953 module_param (default_uid, uint, 0644);
1954 module_param (default_gid, uint, 0644);
1955 module_param (default_perm, uint, 0644);
1956
1957
1958 static struct inode *
1959 gadgetfs_make_inode (struct super_block *sb,
1960                 void *data, struct file_operations *fops,
1961                 int mode)
1962 {
1963         struct inode *inode = new_inode (sb);
1964
1965         if (inode) {
1966                 inode->i_mode = mode;
1967                 inode->i_uid = default_uid;
1968                 inode->i_gid = default_gid;
1969                 inode->i_blksize = PAGE_CACHE_SIZE;
1970                 inode->i_blocks = 0;
1971                 inode->i_atime = inode->i_mtime = inode->i_ctime
1972                                 = CURRENT_TIME;
1973                 inode->u.generic_ip = data;
1974                 inode->i_fop = fops;
1975         }
1976         return inode;
1977 }
1978
1979 /* creates in fs root directory, so non-renamable and non-linkable.
1980  * so inode and dentry are paired, until device reconfig.
1981  */
1982 static struct inode *
1983 gadgetfs_create_file (struct super_block *sb, char const *name,
1984                 void *data, struct file_operations *fops,
1985                 struct dentry **dentry_p)
1986 {
1987         struct dentry   *dentry;
1988         struct inode    *inode;
1989
1990         dentry = d_alloc_name(sb->s_root, name);
1991         if (!dentry)
1992                 return NULL;
1993
1994         inode = gadgetfs_make_inode (sb, data, fops,
1995                         S_IFREG | (default_perm & S_IRWXUGO));
1996         if (!inode) {
1997                 dput(dentry);
1998                 return NULL;
1999         }
2000         d_add (dentry, inode);
2001         *dentry_p = dentry;
2002         return inode;
2003 }
2004
2005 static struct super_operations gadget_fs_operations = {
2006         .statfs =       simple_statfs,
2007         .drop_inode =   generic_delete_inode,
2008 };
2009
2010 static int
2011 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2012 {
2013         struct inode    *inode;
2014         struct dentry   *d;
2015         struct dev_data *dev;
2016
2017         if (the_device)
2018                 return -ESRCH;
2019
2020         /* fake probe to determine $CHIP */
2021         (void) usb_gadget_register_driver (&probe_driver);
2022         if (!CHIP)
2023                 return -ENODEV;
2024
2025         /* superblock */
2026         sb->s_blocksize = PAGE_CACHE_SIZE;
2027         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2028         sb->s_magic = GADGETFS_MAGIC;
2029         sb->s_op = &gadget_fs_operations;
2030         sb->s_time_gran = 1;
2031
2032         /* root inode */
2033         inode = gadgetfs_make_inode (sb,
2034                         NULL, &simple_dir_operations,
2035                         S_IFDIR | S_IRUGO | S_IXUGO);
2036         if (!inode)
2037                 return -ENOMEM;
2038         inode->i_op = &simple_dir_inode_operations;
2039         if (!(d = d_alloc_root (inode))) {
2040                 iput (inode);
2041                 return -ENOMEM;
2042         }
2043         sb->s_root = d;
2044
2045         /* the ep0 file is named after the controller we expect;
2046          * user mode code can use it for sanity checks, like we do.
2047          */
2048         dev = dev_new ();
2049         if (!dev)
2050                 return -ENOMEM;
2051
2052         dev->sb = sb;
2053         if (!(inode = gadgetfs_create_file (sb, CHIP,
2054                                 dev, &dev_init_operations,
2055                                 &dev->dentry))) {
2056                 put_dev(dev);
2057                 return -ENOMEM;
2058         }
2059
2060         /* other endpoint files are available after hardware setup,
2061          * from binding to a controller.
2062          */
2063         the_device = dev;
2064         return 0;
2065 }
2066
2067 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2068 static struct super_block *
2069 gadgetfs_get_sb (struct file_system_type *t, int flags,
2070                 const char *path, void *opts)
2071 {
2072         return get_sb_single (t, flags, opts, gadgetfs_fill_super);
2073 }
2074
2075 static void
2076 gadgetfs_kill_sb (struct super_block *sb)
2077 {
2078         kill_litter_super (sb);
2079         if (the_device) {
2080                 put_dev (the_device);
2081                 the_device = NULL;
2082         }
2083 }
2084
2085 /*----------------------------------------------------------------------*/
2086
2087 static struct file_system_type gadgetfs_type = {
2088         .owner          = THIS_MODULE,
2089         .name           = shortname,
2090         .get_sb         = gadgetfs_get_sb,
2091         .kill_sb        = gadgetfs_kill_sb,
2092 };
2093
2094 /*----------------------------------------------------------------------*/
2095
2096 static int __init init (void)
2097 {
2098         int status;
2099
2100         status = register_filesystem (&gadgetfs_type);
2101         if (status == 0)
2102                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2103                         shortname, driver_desc);
2104         return status;
2105 }
2106 module_init (init);
2107
2108 static void __exit cleanup (void)
2109 {
2110         pr_debug ("unregister %s\n", shortname);
2111         unregister_filesystem (&gadgetfs_type);
2112 }
2113 module_exit (cleanup);
2114