drivers/usb/gadget/inode.c

   1 /*
   2  * inode.c -- user mode filesystem api for usb gadget controllers
   3  *
   4  * Copyright (C) 2003-2004 David Brownell
   5  * Copyright (C) 2003 Agilent Technologies
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * 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 = kzalloc(sizeof(*dev), GFP_KERNEL);
 174         if (!dev)
 175                 return NULL;
 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 %zu OUT, status %d\n",
 421                 data->name, len, (int) 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 %zu IN, status %d\n",
 469                 data->name, len, (int) 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                 usb_ep_disable(data->ep);
 487         }
 488         put_ep (data);
 489         return 0;
 490 }
 491
 492 static int ep_ioctl (struct inode *inode, struct file *fd,
 493                 unsigned code, unsigned long value)
 494 {
 495         struct ep_data          *data = fd->private_data;
 496         int                     status;
 497
 498         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 499                 return status;
 500
 501         spin_lock_irq (&data->dev->lock);
 502         if (likely (data->ep != NULL)) {
 503                 switch (code) {
 504                 case GADGETFS_FIFO_STATUS:
 505                         status = usb_ep_fifo_status (data->ep);
 506                         break;
 507                 case GADGETFS_FIFO_FLUSH:
 508                         usb_ep_fifo_flush (data->ep);
 509                         break;
 510                 case GADGETFS_CLEAR_HALT:
 511                         status = usb_ep_clear_halt (data->ep);
 512                         break;
 513                 default:
 514                         status = -ENOTTY;
 515                 }
 516         } else
 517                 status = -ENODEV;
 518         spin_unlock_irq (&data->dev->lock);
 519         up (&data->lock);
 520         return status;
 521 }
 522
 523 /*----------------------------------------------------------------------*/
 524
 525 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 526
 527 struct kiocb_priv {
 528         struct usb_request      *req;
 529         struct ep_data          *epdata;
 530         void                    *buf;
 531         char __user             *ubuf;
 532         unsigned                actual;
 533 };
 534
 535 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
 536 {
 537         struct kiocb_priv       *priv = iocb->private;
 538         struct ep_data          *epdata;
 539         int                     value;
 540
 541         local_irq_disable();
 542         epdata = priv->epdata;
 543         // spin_lock(&epdata->dev->lock);
 544         kiocbSetCancelled(iocb);
 545         if (likely(epdata && epdata->ep && priv->req))
 546                 value = usb_ep_dequeue (epdata->ep, priv->req);
 547         else
 548                 value = -EINVAL;
 549         // spin_unlock(&epdata->dev->lock);
 550         local_irq_enable();
 551
 552         aio_put_req(iocb);
 553         return value;
 554 }
 555
 556 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
 557 {
 558         struct kiocb_priv       *priv = iocb->private;
 559         ssize_t                 status = priv->actual;
 560
 561         /* we "retry" to get the right mm context for this: */
 562         status = copy_to_user(priv->ubuf, priv->buf, priv->actual);
 563         if (unlikely(0 != status))
 564                 status = -EFAULT;
 565         else
 566                 status = priv->actual;
 567         kfree(priv->buf);
 568         kfree(priv);
 569         aio_put_req(iocb);
 570         return status;
 571 }
 572
 573 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 574 {
 575         struct kiocb            *iocb = req->context;
 576         struct kiocb_priv       *priv = iocb->private;
 577         struct ep_data          *epdata = priv->epdata;
 578
 579         /* lock against disconnect (and ideally, cancel) */
 580         spin_lock(&epdata->dev->lock);
 581         priv->req = NULL;
 582         priv->epdata = NULL;
 583         if (NULL == iocb->ki_retry
 584                         || unlikely(0 == req->actual)
 585                         || unlikely(kiocbIsCancelled(iocb))) {
 586                 kfree(req->buf);
 587                 kfree(priv);
 588                 iocb->private = NULL;
 589                 /* aio_complete() reports bytes-transferred _and_ faults */
 590                 if (unlikely(kiocbIsCancelled(iocb)))
 591                         aio_put_req(iocb);
 592                 else
 593                         aio_complete(iocb,
 594                                 req->actual ? req->actual : req->status,
 595                                 req->status);
 596         } else {
 597                 /* retry() won't report both; so we hide some faults */
 598                 if (unlikely(0 != req->status))
 599                         DBG(epdata->dev, "%s fault %d len %d\n",
 600                                 ep->name, req->status, req->actual);
 601
 602                 priv->buf = req->buf;
 603                 priv->actual = req->actual;
 604                 kick_iocb(iocb);
 605         }
 606         spin_unlock(&epdata->dev->lock);
 607
 608         usb_ep_free_request(ep, req);
 609         put_ep(epdata);
 610 }
 611
 612 static ssize_t
 613 ep_aio_rwtail(
 614         struct kiocb    *iocb,
 615         char            *buf,
 616         size_t          len,
 617         struct ep_data  *epdata,
 618         char __user     *ubuf
 619 )
 620 {
 621         struct kiocb_priv       *priv = (void *) &iocb->private;
 622         struct usb_request      *req;
 623         ssize_t                 value;
 624
 625         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 626         if (!priv) {
 627                 value = -ENOMEM;
 628 fail:
 629                 kfree(buf);
 630                 return value;
 631         }
 632         iocb->private = priv;
 633         priv->ubuf = ubuf;
 634
 635         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 636         if (unlikely(value < 0)) {
 637                 kfree(priv);
 638                 goto fail;
 639         }
 640
 641         iocb->ki_cancel = ep_aio_cancel;
 642         get_ep(epdata);
 643         priv->epdata = epdata;
 644         priv->actual = 0;
 645
 646         /* each kiocb is coupled to one usb_request, but we can't
 647          * allocate or submit those if the host disconnected.
 648          */
 649         spin_lock_irq(&epdata->dev->lock);
 650         if (likely(epdata->ep)) {
 651                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 652                 if (likely(req)) {
 653                         priv->req = req;
 654                         req->buf = buf;
 655                         req->length = len;
 656                         req->complete = ep_aio_complete;
 657                         req->context = iocb;
 658                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 659                         if (unlikely(0 != value))
 660                                 usb_ep_free_request(epdata->ep, req);
 661                 } else
 662                         value = -EAGAIN;
 663         } else
 664                 value = -ENODEV;
 665         spin_unlock_irq(&epdata->dev->lock);
 666
 667         up(&epdata->lock);
 668
 669         if (unlikely(value)) {
 670                 kfree(priv);
 671                 put_ep(epdata);
 672         } else
 673                 value = -EIOCBQUEUED;
 674         return value;
 675 }
 676
 677 static ssize_t
 678 ep_aio_read(struct kiocb *iocb, char __user *ubuf, size_t len, loff_t o)
 679 {
 680         struct ep_data          *epdata = iocb->ki_filp->private_data;
 681         char                    *buf;
 682
 683         if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN))
 684                 return -EINVAL;
 685         buf = kmalloc(len, GFP_KERNEL);
 686         if (unlikely(!buf))
 687                 return -ENOMEM;
 688         iocb->ki_retry = ep_aio_read_retry;
 689         return ep_aio_rwtail(iocb, buf, len, epdata, ubuf);
 690 }
 691
 692 static ssize_t
 693 ep_aio_write(struct kiocb *iocb, const char __user *ubuf, size_t len, loff_t o)
 694 {
 695         struct ep_data          *epdata = iocb->ki_filp->private_data;
 696         char                    *buf;
 697
 698         if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN)))
 699                 return -EINVAL;
 700         buf = kmalloc(len, GFP_KERNEL);
 701         if (unlikely(!buf))
 702                 return -ENOMEM;
 703         if (unlikely(copy_from_user(buf, ubuf, len) != 0)) {
 704                 kfree(buf);
 705                 return -EFAULT;
 706         }
 707         return ep_aio_rwtail(iocb, buf, len, epdata, NULL);
 708 }
 709
 710 /*----------------------------------------------------------------------*/
 711
 712 /* used after endpoint configuration */
 713 static struct file_operations ep_io_operations = {
 714         .owner =        THIS_MODULE,
 715         .llseek =       no_llseek,
 716
 717         .read =         ep_read,
 718         .write =        ep_write,
 719         .ioctl =        ep_ioctl,
 720         .release =      ep_release,
 721
 722         .aio_read =     ep_aio_read,
 723         .aio_write =    ep_aio_write,
 724 };
 725
 726 /* ENDPOINT INITIALIZATION
 727  *
 728  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 729  *     status = write (fd, descriptors, sizeof descriptors)
 730  *
 731  * That write establishes the endpoint configuration, configuring
 732  * the controller to process bulk, interrupt, or isochronous transfers
 733  * at the right maxpacket size, and so on.
 734  *
 735  * The descriptors are message type 1, identified by a host order u32
 736  * at the beginning of what's written.  Descriptor order is: full/low
 737  * speed descriptor, then optional high speed descriptor.
 738  */
 739 static ssize_t
 740 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 741 {
 742         struct ep_data          *data = fd->private_data;
 743         struct usb_ep           *ep;
 744         u32                     tag;
 745         int                     value;
 746
 747         if ((value = down_interruptible (&data->lock)) < 0)
 748                 return value;
 749
 750         if (data->state != STATE_EP_READY) {
 751                 value = -EL2HLT;
 752                 goto fail;
 753         }
 754
 755         value = len;
 756         if (len < USB_DT_ENDPOINT_SIZE + 4)
 757                 goto fail0;
 758
 759         /* we might need to change message format someday */
 760         if (copy_from_user (&tag, buf, 4)) {
 761                 goto fail1;
 762         }
 763         if (tag != 1) {
 764                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 765                 goto fail0;
 766         }
 767         buf += 4;
 768         len -= 4;
 769
 770         /* NOTE:  audio endpoint extensions not accepted here;
 771          * just don't include the extra bytes.
 772          */
 773
 774         /* full/low speed descriptor, then high speed */
 775         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 776                 goto fail1;
 777         }
 778         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 779                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 780                 goto fail0;
 781         if (len != USB_DT_ENDPOINT_SIZE) {
 782                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 783                         goto fail0;
 784                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 785                                         USB_DT_ENDPOINT_SIZE)) {
 786                         goto fail1;
 787                 }
 788                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 789                                 || data->hs_desc.bDescriptorType
 790                                         != USB_DT_ENDPOINT) {
 791                         DBG(data->dev, "config %s, bad hs length or type\n",
 792                                         data->name);
 793                         goto fail0;
 794                 }
 795         }
 796         value = len;
 797
 798         spin_lock_irq (&data->dev->lock);
 799         if (data->dev->state == STATE_DEV_UNBOUND) {
 800                 value = -ENOENT;
 801                 goto gone;
 802         } else if ((ep = data->ep) == NULL) {
 803                 value = -ENODEV;
 804                 goto gone;
 805         }
 806         switch (data->dev->gadget->speed) {
 807         case USB_SPEED_LOW:
 808         case USB_SPEED_FULL:
 809                 value = usb_ep_enable (ep, &data->desc);
 810                 if (value == 0)
 811                         data->state = STATE_EP_ENABLED;
 812                 break;
 813 #ifdef  CONFIG_USB_GADGET_DUALSPEED
 814         case USB_SPEED_HIGH:
 815                 /* fails if caller didn't provide that descriptor... */
 816                 value = usb_ep_enable (ep, &data->hs_desc);
 817                 if (value == 0)
 818                         data->state = STATE_EP_ENABLED;
 819                 break;
 820 #endif
 821         default:
 822                 DBG (data->dev, "unconnected, %s init deferred\n",
 823                                 data->name);
 824                 data->state = STATE_EP_DEFER_ENABLE;
 825         }
 826         if (value == 0)
 827                 fd->f_op = &ep_io_operations;
 828 gone:
 829         spin_unlock_irq (&data->dev->lock);
 830         if (value < 0) {
 831 fail:
 832                 data->desc.bDescriptorType = 0;
 833                 data->hs_desc.bDescriptorType = 0;
 834         }
 835         up (&data->lock);
 836         return value;
 837 fail0:
 838         value = -EINVAL;
 839         goto fail;
 840 fail1:
 841         value = -EFAULT;
 842         goto fail;
 843 }
 844
 845 static int
 846 ep_open (struct inode *inode, struct file *fd)
 847 {
 848         struct ep_data          *data = inode->u.generic_ip;
 849         int                     value = -EBUSY;
 850
 851         if (down_interruptible (&data->lock) != 0)
 852                 return -EINTR;
 853         spin_lock_irq (&data->dev->lock);
 854         if (data->dev->state == STATE_DEV_UNBOUND)
 855                 value = -ENOENT;
 856         else if (data->state == STATE_EP_DISABLED) {
 857                 value = 0;
 858                 data->state = STATE_EP_READY;
 859                 get_ep (data);
 860                 fd->private_data = data;
 861                 VDEBUG (data->dev, "%s ready\n", data->name);
 862         } else
 863                 DBG (data->dev, "%s state %d\n",
 864                         data->name, data->state);
 865         spin_unlock_irq (&data->dev->lock);
 866         up (&data->lock);
 867         return value;
 868 }
 869
 870 /* used before endpoint configuration */
 871 static struct file_operations ep_config_operations = {
 872         .owner =        THIS_MODULE,
 873         .llseek =       no_llseek,
 874
 875         .open =         ep_open,
 876         .write =        ep_config,
 877         .release =      ep_release,
 878 };
 879
 880 /*----------------------------------------------------------------------*/
 881
 882 /* EP0 IMPLEMENTATION can be partly in userspace.
 883  *
 884  * Drivers that use this facility receive various events, including
 885  * control requests the kernel doesn't handle.  Drivers that don't
 886  * use this facility may be too simple-minded for real applications.
 887  */
 888
 889 static inline void ep0_readable (struct dev_data *dev)
 890 {
 891         wake_up (&dev->wait);
 892         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 893 }
 894
 895 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 896 {
 897         struct dev_data         *dev = ep->driver_data;
 898
 899         if (req->buf != dev->rbuf) {
 900                 usb_ep_free_buffer (ep, req->buf, req->dma, req->length);
 901                 req->buf = dev->rbuf;
 902                 req->dma = DMA_ADDR_INVALID;
 903         }
 904         req->complete = epio_complete;
 905         dev->setup_out_ready = 0;
 906 }
 907
 908 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 909 {
 910         struct dev_data         *dev = ep->driver_data;
 911         int                     free = 1;
 912
 913         /* for control OUT, data must still get to userspace */
 914         if (!dev->setup_in) {
 915                 dev->setup_out_error = (req->status != 0);
 916                 if (!dev->setup_out_error)
 917                         free = 0;
 918                 dev->setup_out_ready = 1;
 919                 ep0_readable (dev);
 920         } else if (dev->state == STATE_SETUP)
 921                 dev->state = STATE_CONNECTED;
 922
 923         /* clean up as appropriate */
 924         if (free && req->buf != &dev->rbuf)
 925                 clean_req (ep, req);
 926         req->complete = epio_complete;
 927 }
 928
 929 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 930 {
 931         struct dev_data *dev = ep->driver_data;
 932
 933         if (dev->setup_out_ready) {
 934                 DBG (dev, "ep0 request busy!\n");
 935                 return -EBUSY;
 936         }
 937         if (len > sizeof (dev->rbuf))
 938                 req->buf = usb_ep_alloc_buffer (ep, len, &req->dma, GFP_ATOMIC);
 939         if (req->buf == 0) {
 940                 req->buf = dev->rbuf;
 941                 return -ENOMEM;
 942         }
 943         req->complete = ep0_complete;
 944         req->length = len;
 945         req->zero = 0;
 946         return 0;
 947 }
 948
 949 static ssize_t
 950 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 951 {
 952         struct dev_data                 *dev = fd->private_data;
 953         ssize_t                         retval;
 954         enum ep0_state                  state;
 955
 956         spin_lock_irq (&dev->lock);
 957
 958         /* report fd mode change before acting on it */
 959         if (dev->setup_abort) {
 960                 dev->setup_abort = 0;
 961                 retval = -EIDRM;
 962                 goto done;
 963         }
 964
 965         /* control DATA stage */
 966         if ((state = dev->state) == STATE_SETUP) {
 967
 968                 if (dev->setup_in) {            /* stall IN */
 969                         VDEBUG(dev, "ep0in stall\n");
 970                         (void) usb_ep_set_halt (dev->gadget->ep0);
 971                         retval = -EL2HLT;
 972                         dev->state = STATE_CONNECTED;
 973
 974                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
 975                         struct usb_ep           *ep = dev->gadget->ep0;
 976                         struct usb_request      *req = dev->req;
 977
 978                         if ((retval = setup_req (ep, req, 0)) == 0)
 979                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
 980                         dev->state = STATE_CONNECTED;
 981
 982                         /* assume that was SET_CONFIGURATION */
 983                         if (dev->current_config) {
 984                                 unsigned power;
 985 #ifdef  CONFIG_USB_GADGET_DUALSPEED
 986                                 if (dev->gadget->speed == USB_SPEED_HIGH)
 987                                         power = dev->hs_config->bMaxPower;
 988                                 else
 989 #endif
 990                                         power = dev->config->bMaxPower;
 991                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
 992                         }
 993
 994                 } else {                        /* collect OUT data */
 995                         if ((fd->f_flags & O_NONBLOCK) != 0
 996                                         && !dev->setup_out_ready) {
 997                                 retval = -EAGAIN;
 998                                 goto done;
 999                         }
1000                         spin_unlock_irq (&dev->lock);
1001                         retval = wait_event_interruptible (dev->wait,
1002                                         dev->setup_out_ready != 0);
1003
1004                         /* FIXME state could change from under us */
1005                         spin_lock_irq (&dev->lock);
1006                         if (retval)
1007                                 goto done;
1008                         if (dev->setup_out_error)
1009                                 retval = -EIO;
1010                         else {
1011                                 len = min (len, (size_t)dev->req->actual);
1012 // FIXME don't call this with the spinlock held ...
1013                                 if (copy_to_user (buf, &dev->req->buf, len))
1014                                         retval = -EFAULT;
1015                                 clean_req (dev->gadget->ep0, dev->req);
1016                                 /* NOTE userspace can't yet choose to stall */
1017                         }
1018                 }
1019                 goto done;
1020         }
1021
1022         /* else normal: return event data */
1023         if (len < sizeof dev->event [0]) {
1024                 retval = -EINVAL;
1025                 goto done;
1026         }
1027         len -= len % sizeof (struct usb_gadgetfs_event);
1028         dev->usermode_setup = 1;
1029
1030 scan:
1031         /* return queued events right away */
1032         if (dev->ev_next != 0) {
1033                 unsigned                i, n;
1034                 int                     tmp = dev->ev_next;
1035
1036                 len = min (len, tmp * sizeof (struct usb_gadgetfs_event));
1037                 n = len / sizeof (struct usb_gadgetfs_event);
1038
1039                 /* ep0 can't deliver events when STATE_SETUP */
1040                 for (i = 0; i < n; i++) {
1041                         if (dev->event [i].type == GADGETFS_SETUP) {
1042                                 len = n = i + 1;
1043                                 len *= sizeof (struct usb_gadgetfs_event);
1044                                 n = 0;
1045                                 break;
1046                         }
1047                 }
1048                 spin_unlock_irq (&dev->lock);
1049                 if (copy_to_user (buf, &dev->event, len))
1050                         retval = -EFAULT;
1051                 else
1052                         retval = len;
1053                 if (len > 0) {
1054                         len /= sizeof (struct usb_gadgetfs_event);
1055
1056                         /* NOTE this doesn't guard against broken drivers;
1057                          * concurrent ep0 readers may lose events.
1058                          */
1059                         spin_lock_irq (&dev->lock);
1060                         dev->ev_next -= len;
1061                         if (dev->ev_next != 0)
1062                                 memmove (&dev->event, &dev->event [len],
1063                                         sizeof (struct usb_gadgetfs_event)
1064                                                 * (tmp - len));
1065                         if (n == 0)
1066                                 dev->state = STATE_SETUP;
1067                         spin_unlock_irq (&dev->lock);
1068                 }
1069                 return retval;
1070         }
1071         if (fd->f_flags & O_NONBLOCK) {
1072                 retval = -EAGAIN;
1073                 goto done;
1074         }
1075
1076         switch (state) {
1077         default:
1078                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, state);
1079                 retval = -ESRCH;
1080                 break;
1081         case STATE_UNCONNECTED:
1082         case STATE_CONNECTED:
1083                 spin_unlock_irq (&dev->lock);
1084                 DBG (dev, "%s wait\n", __FUNCTION__);
1085
1086                 /* wait for events */
1087                 retval = wait_event_interruptible (dev->wait,
1088                                 dev->ev_next != 0);
1089                 if (retval < 0)
1090                         return retval;
1091                 spin_lock_irq (&dev->lock);
1092                 goto scan;
1093         }
1094
1095 done:
1096         spin_unlock_irq (&dev->lock);
1097         return retval;
1098 }
1099
1100 static struct usb_gadgetfs_event *
1101 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1102 {
1103         struct usb_gadgetfs_event       *event;
1104         unsigned                        i;
1105
1106         switch (type) {
1107         /* these events purge the queue */
1108         case GADGETFS_DISCONNECT:
1109                 if (dev->state == STATE_SETUP)
1110                         dev->setup_abort = 1;
1111                 // FALL THROUGH
1112         case GADGETFS_CONNECT:
1113                 dev->ev_next = 0;
1114                 break;
1115         case GADGETFS_SETUP:            /* previous request timed out */
1116         case GADGETFS_SUSPEND:          /* same effect */
1117                 /* these events can't be repeated */
1118                 for (i = 0; i != dev->ev_next; i++) {
1119                         if (dev->event [i].type != type)
1120                                 continue;
1121                         DBG (dev, "discard old event %d\n", type);
1122                         dev->ev_next--;
1123                         if (i == dev->ev_next)
1124                                 break;
1125                         /* indices start at zero, for simplicity */
1126                         memmove (&dev->event [i], &dev->event [i + 1],
1127                                 sizeof (struct usb_gadgetfs_event)
1128                                         * (dev->ev_next - i));
1129                 }
1130                 break;
1131         default:
1132                 BUG ();
1133         }
1134         event = &dev->event [dev->ev_next++];
1135         BUG_ON (dev->ev_next > N_EVENT);
1136         VDEBUG (dev, "ev %d, next %d\n", type, dev->ev_next);
1137         memset (event, 0, sizeof *event);
1138         event->type = type;
1139         return event;
1140 }
1141
1142 static ssize_t
1143 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1144 {
1145         struct dev_data         *dev = fd->private_data;
1146         ssize_t                 retval = -ESRCH;
1147
1148         spin_lock_irq (&dev->lock);
1149
1150         /* report fd mode change before acting on it */
1151         if (dev->setup_abort) {
1152                 dev->setup_abort = 0;
1153                 retval = -EIDRM;
1154
1155         /* data and/or status stage for control request */
1156         } else if (dev->state == STATE_SETUP) {
1157
1158                 /* IN DATA+STATUS caller makes len <= wLength */
1159                 if (dev->setup_in) {
1160                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1161                         if (retval == 0) {
1162                                 spin_unlock_irq (&dev->lock);
1163                                 if (copy_from_user (dev->req->buf, buf, len))
1164                                         retval = -EFAULT;
1165                                 else {
1166                                         if (len < dev->setup_wLength)
1167                                                 dev->req->zero = 1;
1168                                         retval = usb_ep_queue (
1169                                                 dev->gadget->ep0, dev->req,
1170                                                 GFP_KERNEL);
1171                                 }
1172                                 if (retval < 0) {
1173                                         spin_lock_irq (&dev->lock);
1174                                         clean_req (dev->gadget->ep0, dev->req);
1175                                         spin_unlock_irq (&dev->lock);
1176                                 } else
1177                                         retval = len;
1178
1179                                 return retval;
1180                         }
1181
1182                 /* can stall some OUT transfers */
1183                 } else if (dev->setup_can_stall) {
1184                         VDEBUG(dev, "ep0out stall\n");
1185                         (void) usb_ep_set_halt (dev->gadget->ep0);
1186                         retval = -EL2HLT;
1187                         dev->state = STATE_CONNECTED;
1188                 } else {
1189                         DBG(dev, "bogus ep0out stall!\n");
1190                 }
1191         } else
1192                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state);
1193
1194         spin_unlock_irq (&dev->lock);
1195         return retval;
1196 }
1197
1198 static int
1199 ep0_fasync (int f, struct file *fd, int on)
1200 {
1201         struct dev_data         *dev = fd->private_data;
1202         // caller must F_SETOWN before signal delivery happens
1203         VDEBUG (dev, "%s %s\n", __FUNCTION__, on ? "on" : "off");
1204         return fasync_helper (f, fd, on, &dev->fasync);
1205 }
1206
1207 static struct usb_gadget_driver gadgetfs_driver;
1208
1209 static int
1210 dev_release (struct inode *inode, struct file *fd)
1211 {
1212         struct dev_data         *dev = fd->private_data;
1213
1214         /* closing ep0 === shutdown all */
1215
1216         usb_gadget_unregister_driver (&gadgetfs_driver);
1217
1218         /* at this point "good" hardware has disconnected the
1219          * device from USB; the host won't see it any more.
1220          * alternatively, all host requests will time out.
1221          */
1222
1223         fasync_helper (-1, fd, 0, &dev->fasync);
1224         kfree (dev->buf);
1225         dev->buf = NULL;
1226         put_dev (dev);
1227
1228         /* other endpoints were all decoupled from this device */
1229         dev->state = STATE_DEV_DISABLED;
1230         return 0;
1231 }
1232
1233 static int dev_ioctl (struct inode *inode, struct file *fd,
1234                 unsigned code, unsigned long value)
1235 {
1236         struct dev_data         *dev = fd->private_data;
1237         struct usb_gadget       *gadget = dev->gadget;
1238
1239         if (gadget->ops->ioctl)
1240                 return gadget->ops->ioctl (gadget, code, value);
1241         return -ENOTTY;
1242 }
1243
1244 /* used after device configuration */
1245 static struct file_operations ep0_io_operations = {
1246         .owner =        THIS_MODULE,
1247         .llseek =       no_llseek,
1248
1249         .read =         ep0_read,
1250         .write =        ep0_write,
1251         .fasync =       ep0_fasync,
1252         // .poll =      ep0_poll,
1253         .ioctl =        dev_ioctl,
1254         .release =      dev_release,
1255 };
1256
1257 /*----------------------------------------------------------------------*/
1258
1259 /* The in-kernel gadget driver handles most ep0 issues, in particular
1260  * enumerating the single configuration (as provided from user space).
1261  *
1262  * Unrecognized ep0 requests may be handled in user space.
1263  */
1264
1265 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1266 static void make_qualifier (struct dev_data *dev)
1267 {
1268         struct usb_qualifier_descriptor         qual;
1269         struct usb_device_descriptor            *desc;
1270
1271         qual.bLength = sizeof qual;
1272         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1273         qual.bcdUSB = __constant_cpu_to_le16 (0x0200);
1274
1275         desc = dev->dev;
1276         qual.bDeviceClass = desc->bDeviceClass;
1277         qual.bDeviceSubClass = desc->bDeviceSubClass;
1278         qual.bDeviceProtocol = desc->bDeviceProtocol;
1279
1280         /* assumes ep0 uses the same value for both speeds ... */
1281         qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
1282
1283         qual.bNumConfigurations = 1;
1284         qual.bRESERVED = 0;
1285
1286         memcpy (dev->rbuf, &qual, sizeof qual);
1287 }
1288 #endif
1289
1290 static int
1291 config_buf (struct dev_data *dev, u8 type, unsigned index)
1292 {
1293         int             len;
1294 #ifdef CONFIG_USB_GADGET_DUALSPEED
1295         int             hs;
1296 #endif
1297
1298         /* only one configuration */
1299         if (index > 0)
1300                 return -EINVAL;
1301
1302 #ifdef CONFIG_USB_GADGET_DUALSPEED
1303         hs = (dev->gadget->speed == USB_SPEED_HIGH);
1304         if (type == USB_DT_OTHER_SPEED_CONFIG)
1305                 hs = !hs;
1306         if (hs) {
1307                 dev->req->buf = dev->hs_config;
1308                 len = le16_to_cpup (&dev->hs_config->wTotalLength);
1309         } else
1310 #endif
1311         {
1312                 dev->req->buf = dev->config;
1313                 len = le16_to_cpup (&dev->config->wTotalLength);
1314         }
1315         ((u8 *)dev->req->buf) [1] = type;
1316         return len;
1317 }
1318
1319 static int
1320 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1321 {
1322         struct dev_data                 *dev = get_gadget_data (gadget);
1323         struct usb_request              *req = dev->req;
1324         int                             value = -EOPNOTSUPP;
1325         struct usb_gadgetfs_event       *event;
1326         u16                             w_value = le16_to_cpu(ctrl->wValue);
1327         u16                             w_length = le16_to_cpu(ctrl->wLength);
1328
1329         spin_lock (&dev->lock);
1330         dev->setup_abort = 0;
1331         if (dev->state == STATE_UNCONNECTED) {
1332                 struct usb_ep   *ep;
1333                 struct ep_data  *data;
1334
1335                 dev->state = STATE_CONNECTED;
1336                 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1337
1338 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1339                 if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) {
1340                         ERROR (dev, "no high speed config??\n");
1341                         return -EINVAL;
1342                 }
1343 #endif  /* CONFIG_USB_GADGET_DUALSPEED */
1344
1345                 INFO (dev, "connected\n");
1346                 event = next_event (dev, GADGETFS_CONNECT);
1347                 event->u.speed = gadget->speed;
1348                 ep0_readable (dev);
1349
1350                 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
1351                         data = ep->driver_data;
1352                         /* ... down_trylock (&data->lock) ... */
1353                         if (data->state != STATE_EP_DEFER_ENABLE)
1354                                 continue;
1355 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1356                         if (gadget->speed == USB_SPEED_HIGH)
1357                                 value = usb_ep_enable (ep, &data->hs_desc);
1358                         else
1359 #endif  /* CONFIG_USB_GADGET_DUALSPEED */
1360                                 value = usb_ep_enable (ep, &data->desc);
1361                         if (value) {
1362                                 ERROR (dev, "deferred %s enable --> %d\n",
1363                                         data->name, value);
1364                                 continue;
1365                         }
1366                         data->state = STATE_EP_ENABLED;
1367                         wake_up (&data->wait);
1368                         DBG (dev, "woke up %s waiters\n", data->name);
1369                 }
1370
1371         /* host may have given up waiting for response.  we can miss control
1372          * requests handled lower down (device/endpoint status and features);
1373          * then ep0_{read,write} will report the wrong status. controller
1374          * driver will have aborted pending i/o.
1375          */
1376         } else if (dev->state == STATE_SETUP)
1377                 dev->setup_abort = 1;
1378
1379         req->buf = dev->rbuf;
1380         req->dma = DMA_ADDR_INVALID;
1381         req->context = NULL;
1382         value = -EOPNOTSUPP;
1383         switch (ctrl->bRequest) {
1384
1385         case USB_REQ_GET_DESCRIPTOR:
1386                 if (ctrl->bRequestType != USB_DIR_IN)
1387                         goto unrecognized;
1388                 switch (w_value >> 8) {
1389
1390                 case USB_DT_DEVICE:
1391                         value = min (w_length, (u16) sizeof *dev->dev);
1392                         req->buf = dev->dev;
1393                         break;
1394 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1395                 case USB_DT_DEVICE_QUALIFIER:
1396                         if (!dev->hs_config)
1397                                 break;
1398                         value = min (w_length, (u16)
1399                                 sizeof (struct usb_qualifier_descriptor));
1400                         make_qualifier (dev);
1401                         break;
1402                 case USB_DT_OTHER_SPEED_CONFIG:
1403                         // FALLTHROUGH
1404 #endif
1405                 case USB_DT_CONFIG:
1406                         value = config_buf (dev,
1407                                         w_value >> 8,
1408                                         w_value & 0xff);
1409                         if (value >= 0)
1410                                 value = min (w_length, (u16) value);
1411                         break;
1412                 case USB_DT_STRING:
1413                         goto unrecognized;
1414
1415                 default:                // all others are errors
1416                         break;
1417                 }
1418                 break;
1419
1420         /* currently one config, two speeds */
1421         case USB_REQ_SET_CONFIGURATION:
1422                 if (ctrl->bRequestType != 0)
1423                         break;
1424                 if (0 == (u8) w_value) {
1425                         value = 0;
1426                         dev->current_config = 0;
1427                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1428                         // user mode expected to disable endpoints
1429                 } else {
1430                         u8      config, power;
1431 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1432                         if (gadget->speed == USB_SPEED_HIGH) {
1433                                 config = dev->hs_config->bConfigurationValue;
1434                                 power = dev->hs_config->bMaxPower;
1435                         } else
1436 #endif
1437                         {
1438                                 config = dev->config->bConfigurationValue;
1439                                 power = dev->config->bMaxPower;
1440                         }
1441
1442                         if (config == (u8) w_value) {
1443                                 value = 0;
1444                                 dev->current_config = config;
1445                                 usb_gadget_vbus_draw(gadget, 2 * power);
1446                         }
1447                 }
1448
1449                 /* report SET_CONFIGURATION like any other control request,
1450                  * except that usermode may not stall this.  the next
1451                  * request mustn't be allowed start until this finishes:
1452                  * endpoints and threads set up, etc.
1453                  *
1454                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1455                  * has bad/racey automagic that prevents synchronizing here.
1456                  * even kernel mode drivers often miss them.
1457                  */
1458                 if (value == 0) {
1459                         INFO (dev, "configuration #%d\n", dev->current_config);
1460                         if (dev->usermode_setup) {
1461                                 dev->setup_can_stall = 0;
1462                                 goto delegate;
1463                         }
1464                 }
1465                 break;
1466
1467 #ifndef CONFIG_USB_GADGETFS_PXA2XX
1468         /* PXA automagically handles this request too */
1469         case USB_REQ_GET_CONFIGURATION:
1470                 if (ctrl->bRequestType != 0x80)
1471                         break;
1472                 *(u8 *)req->buf = dev->current_config;
1473                 value = min (w_length, (u16) 1);
1474                 break;
1475 #endif
1476
1477         default:
1478 unrecognized:
1479                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1480                         dev->usermode_setup ? "delegate" : "fail",
1481                         ctrl->bRequestType, ctrl->bRequest,
1482                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1483
1484                 /* if there's an ep0 reader, don't stall */
1485                 if (dev->usermode_setup) {
1486                         dev->setup_can_stall = 1;
1487 delegate:
1488                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1489                                                 ? 1 : 0;
1490                         dev->setup_wLength = w_length;
1491                         dev->setup_out_ready = 0;
1492                         dev->setup_out_error = 0;
1493                         value = 0;
1494
1495                         /* read DATA stage for OUT right away */
1496                         if (unlikely (!dev->setup_in && w_length)) {
1497                                 value = setup_req (gadget->ep0, dev->req,
1498                                                         w_length);
1499                                 if (value < 0)
1500                                         break;
1501                                 value = usb_ep_queue (gadget->ep0, dev->req,
1502                                                         GFP_ATOMIC);
1503                                 if (value < 0) {
1504                                         clean_req (gadget->ep0, dev->req);
1505                                         break;
1506                                 }
1507
1508                                 /* we can't currently stall these */
1509                                 dev->setup_can_stall = 0;
1510                         }
1511
1512                         /* state changes when reader collects event */
1513                         event = next_event (dev, GADGETFS_SETUP);
1514                         event->u.setup = *ctrl;
1515                         ep0_readable (dev);
1516                         spin_unlock (&dev->lock);
1517                         return 0;
1518                 }
1519         }
1520
1521         /* proceed with data transfer and status phases? */
1522         if (value >= 0 && dev->state != STATE_SETUP) {
1523                 req->length = value;
1524                 req->zero = value < w_length;
1525                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1526                 if (value < 0) {
1527                         DBG (dev, "ep_queue --> %d\n", value);
1528                         req->status = 0;
1529                 }
1530         }
1531
1532         /* device stalls when value < 0 */
1533         spin_unlock (&dev->lock);
1534         return value;
1535 }
1536
1537 static void destroy_ep_files (struct dev_data *dev)
1538 {
1539         struct list_head        *entry, *tmp;
1540
1541         DBG (dev, "%s %d\n", __FUNCTION__, dev->state);
1542
1543         /* dev->state must prevent interference */
1544 restart:
1545         spin_lock_irq (&dev->lock);
1546         list_for_each_safe (entry, tmp, &dev->epfiles) {
1547                 struct ep_data  *ep;
1548                 struct inode    *parent;
1549                 struct dentry   *dentry;
1550
1551                 /* break link to FS */
1552                 ep = list_entry (entry, struct ep_data, epfiles);
1553                 list_del_init (&ep->epfiles);
1554                 dentry = ep->dentry;
1555                 ep->dentry = NULL;
1556                 parent = dentry->d_parent->d_inode;
1557
1558                 /* break link to controller */
1559                 if (ep->state == STATE_EP_ENABLED)
1560                         (void) usb_ep_disable (ep->ep);
1561                 ep->state = STATE_EP_UNBOUND;
1562                 usb_ep_free_request (ep->ep, ep->req);
1563                 ep->ep = NULL;
1564                 wake_up (&ep->wait);
1565                 put_ep (ep);
1566
1567                 spin_unlock_irq (&dev->lock);
1568
1569                 /* break link to dcache */
1570                 mutex_lock (&parent->i_mutex);
1571                 d_delete (dentry);
1572                 dput (dentry);
1573                 mutex_unlock (&parent->i_mutex);
1574
1575                 /* fds may still be open */
1576                 goto restart;
1577         }
1578         spin_unlock_irq (&dev->lock);
1579 }
1580
1581
1582 static struct inode *
1583 gadgetfs_create_file (struct super_block *sb, char const *name,
1584                 void *data, const struct file_operations *fops,
1585                 struct dentry **dentry_p);
1586
1587 static int activate_ep_files (struct dev_data *dev)
1588 {
1589         struct usb_ep   *ep;
1590
1591         gadget_for_each_ep (ep, dev->gadget) {
1592                 struct ep_data  *data;
1593
1594                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1595                 if (!data)
1596                         goto enomem;
1597                 data->state = STATE_EP_DISABLED;
1598                 init_MUTEX (&data->lock);
1599                 init_waitqueue_head (&data->wait);
1600
1601                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1602                 atomic_set (&data->count, 1);
1603                 data->dev = dev;
1604                 get_dev (dev);
1605
1606                 data->ep = ep;
1607                 ep->driver_data = data;
1608
1609                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1610                 if (!data->req)
1611                         goto enomem;
1612
1613                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1614                                 data, &ep_config_operations,
1615                                 &data->dentry);
1616                 if (!data->inode) {
1617                         kfree (data);
1618                         goto enomem;
1619                 }
1620                 list_add_tail (&data->epfiles, &dev->epfiles);
1621         }
1622         return 0;
1623
1624 enomem:
1625         DBG (dev, "%s enomem\n", __FUNCTION__);
1626         destroy_ep_files (dev);
1627         return -ENOMEM;
1628 }
1629
1630 static void
1631 gadgetfs_unbind (struct usb_gadget *gadget)
1632 {
1633         struct dev_data         *dev = get_gadget_data (gadget);
1634
1635         DBG (dev, "%s\n", __FUNCTION__);
1636
1637         spin_lock_irq (&dev->lock);
1638         dev->state = STATE_DEV_UNBOUND;
1639         spin_unlock_irq (&dev->lock);
1640
1641         destroy_ep_files (dev);
1642         gadget->ep0->driver_data = NULL;
1643         set_gadget_data (gadget, NULL);
1644
1645         /* we've already been disconnected ... no i/o is active */
1646         if (dev->req)
1647                 usb_ep_free_request (gadget->ep0, dev->req);
1648         DBG (dev, "%s done\n", __FUNCTION__);
1649         put_dev (dev);
1650 }
1651
1652 static struct dev_data          *the_device;
1653
1654 static int
1655 gadgetfs_bind (struct usb_gadget *gadget)
1656 {
1657         struct dev_data         *dev = the_device;
1658
1659         if (!dev)
1660                 return -ESRCH;
1661         if (0 != strcmp (CHIP, gadget->name)) {
1662                 printk (KERN_ERR "%s expected %s controller not %s\n",
1663                         shortname, CHIP, gadget->name);
1664                 return -ENODEV;
1665         }
1666
1667         set_gadget_data (gadget, dev);
1668         dev->gadget = gadget;
1669         gadget->ep0->driver_data = dev;
1670         dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1671
1672         /* preallocate control response and buffer */
1673         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1674         if (!dev->req)
1675                 goto enomem;
1676         dev->req->context = NULL;
1677         dev->req->complete = epio_complete;
1678
1679         if (activate_ep_files (dev) < 0)
1680                 goto enomem;
1681
1682         INFO (dev, "bound to %s driver\n", gadget->name);
1683         dev->state = STATE_UNCONNECTED;
1684         get_dev (dev);
1685         return 0;
1686
1687 enomem:
1688         gadgetfs_unbind (gadget);
1689         return -ENOMEM;
1690 }
1691
1692 static void
1693 gadgetfs_disconnect (struct usb_gadget *gadget)
1694 {
1695         struct dev_data         *dev = get_gadget_data (gadget);
1696
1697         if (dev->state == STATE_UNCONNECTED) {
1698                 DBG (dev, "already unconnected\n");
1699                 return;
1700         }
1701         dev->state = STATE_UNCONNECTED;
1702
1703         INFO (dev, "disconnected\n");
1704         spin_lock (&dev->lock);
1705         next_event (dev, GADGETFS_DISCONNECT);
1706         ep0_readable (dev);
1707         spin_unlock (&dev->lock);
1708 }
1709
1710 static void
1711 gadgetfs_suspend (struct usb_gadget *gadget)
1712 {
1713         struct dev_data         *dev = get_gadget_data (gadget);
1714
1715         INFO (dev, "suspended from state %d\n", dev->state);
1716         spin_lock (&dev->lock);
1717         switch (dev->state) {
1718         case STATE_SETUP:               // VERY odd... host died??
1719         case STATE_CONNECTED:
1720         case STATE_UNCONNECTED:
1721                 next_event (dev, GADGETFS_SUSPEND);
1722                 ep0_readable (dev);
1723                 /* FALLTHROUGH */
1724         default:
1725                 break;
1726         }
1727         spin_unlock (&dev->lock);
1728 }
1729
1730 static struct usb_gadget_driver gadgetfs_driver = {
1731 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1732         .speed          = USB_SPEED_HIGH,
1733 #else
1734         .speed          = USB_SPEED_FULL,
1735 #endif
1736         .function       = (char *) driver_desc,
1737         .bind           = gadgetfs_bind,
1738         .unbind         = gadgetfs_unbind,
1739         .setup          = gadgetfs_setup,
1740         .disconnect     = gadgetfs_disconnect,
1741         .suspend        = gadgetfs_suspend,
1742
1743         .driver         = {
1744                 .name           = (char *) shortname,
1745         },
1746 };
1747
1748 /*----------------------------------------------------------------------*/
1749
1750 static void gadgetfs_nop(struct usb_gadget *arg) { }
1751
1752 static int gadgetfs_probe (struct usb_gadget *gadget)
1753 {
1754         CHIP = gadget->name;
1755         return -EISNAM;
1756 }
1757
1758 static struct usb_gadget_driver probe_driver = {
1759         .speed          = USB_SPEED_HIGH,
1760         .bind           = gadgetfs_probe,
1761         .unbind         = gadgetfs_nop,
1762         .setup          = (void *)gadgetfs_nop,
1763         .disconnect     = gadgetfs_nop,
1764         .driver         = {
1765                 .name           = "nop",
1766         },
1767 };
1768
1769
1770 /* DEVICE INITIALIZATION
1771  *
1772  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1773  *     status = write (fd, descriptors, sizeof descriptors)
1774  *
1775  * That write establishes the device configuration, so the kernel can
1776  * bind to the controller ... guaranteeing it can handle enumeration
1777  * at all necessary speeds.  Descriptor order is:
1778  *
1779  * . message tag (u32, host order) ... for now, must be zero; it
1780  *      would change to support features like multi-config devices
1781  * . full/low speed config ... all wTotalLength bytes (with interface,
1782  *      class, altsetting, endpoint, and other descriptors)
1783  * . high speed config ... all descriptors, for high speed operation;
1784  *      this one's optional except for high-speed hardware
1785  * . device descriptor
1786  *
1787  * Endpoints are not yet enabled. Drivers may want to immediately
1788  * initialize them, using the /dev/gadget/ep* files that are available
1789  * as soon as the kernel sees the configuration, or they can wait
1790  * until device configuration and interface altsetting changes create
1791  * the need to configure (or unconfigure) them.
1792  *
1793  * After initialization, the device stays active for as long as that
1794  * $CHIP file is open.  Events may then be read from that descriptor,
1795  * such configuration notifications.  More complex drivers will handle
1796  * some control requests in user space.
1797  */
1798
1799 static int is_valid_config (struct usb_config_descriptor *config)
1800 {
1801         return config->bDescriptorType == USB_DT_CONFIG
1802                 && config->bLength == USB_DT_CONFIG_SIZE
1803                 && config->bConfigurationValue != 0
1804                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1805                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1806         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1807         /* FIXME check lengths: walk to end */
1808 }
1809
1810 static ssize_t
1811 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1812 {
1813         struct dev_data         *dev = fd->private_data;
1814         ssize_t                 value = len, length = len;
1815         unsigned                total;
1816         u32                     tag;
1817         char                    *kbuf;
1818
1819         if (dev->state != STATE_OPENED)
1820                 return -EEXIST;
1821
1822         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1823                 return -EINVAL;
1824
1825         /* we might need to change message format someday */
1826         if (copy_from_user (&tag, buf, 4))
1827                 return -EFAULT;
1828         if (tag != 0)
1829                 return -EINVAL;
1830         buf += 4;
1831         length -= 4;
1832
1833         kbuf = kmalloc (length, SLAB_KERNEL);
1834         if (!kbuf)
1835                 return -ENOMEM;
1836         if (copy_from_user (kbuf, buf, length)) {
1837                 kfree (kbuf);
1838                 return -EFAULT;
1839         }
1840
1841         spin_lock_irq (&dev->lock);
1842         value = -EINVAL;
1843         if (dev->buf)
1844                 goto fail;
1845         dev->buf = kbuf;
1846
1847         /* full or low speed config */
1848         dev->config = (void *) kbuf;
1849         total = le16_to_cpup (&dev->config->wTotalLength);
1850         if (!is_valid_config (dev->config) || total >= length)
1851                 goto fail;
1852         kbuf += total;
1853         length -= total;
1854
1855         /* optional high speed config */
1856         if (kbuf [1] == USB_DT_CONFIG) {
1857                 dev->hs_config = (void *) kbuf;
1858                 total = le16_to_cpup (&dev->hs_config->wTotalLength);
1859                 if (!is_valid_config (dev->hs_config) || total >= length)
1860                         goto fail;
1861                 kbuf += total;
1862                 length -= total;
1863         }
1864
1865         /* could support multiple configs, using another encoding! */
1866
1867         /* device descriptor (tweaked for paranoia) */
1868         if (length != USB_DT_DEVICE_SIZE)
1869                 goto fail;
1870         dev->dev = (void *)kbuf;
1871         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1872                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1873                         || dev->dev->bNumConfigurations != 1)
1874                 goto fail;
1875         dev->dev->bNumConfigurations = 1;
1876         dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200);
1877
1878         /* triggers gadgetfs_bind(); then we can enumerate. */
1879         spin_unlock_irq (&dev->lock);
1880         value = usb_gadget_register_driver (&gadgetfs_driver);
1881         if (value != 0) {
1882                 kfree (dev->buf);
1883                 dev->buf = NULL;
1884         } else {
1885                 /* at this point "good" hardware has for the first time
1886                  * let the USB the host see us.  alternatively, if users
1887                  * unplug/replug that will clear all the error state.
1888                  *
1889                  * note:  everything running before here was guaranteed
1890                  * to choke driver model style diagnostics.  from here
1891                  * on, they can work ... except in cleanup paths that
1892                  * kick in after the ep0 descriptor is closed.
1893                  */
1894                 fd->f_op = &ep0_io_operations;
1895                 value = len;
1896         }
1897         return value;
1898
1899 fail:
1900         spin_unlock_irq (&dev->lock);
1901         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __FUNCTION__, value, dev);
1902         kfree (dev->buf);
1903         dev->buf = NULL;
1904         return value;
1905 }
1906
1907 static int
1908 dev_open (struct inode *inode, struct file *fd)
1909 {
1910         struct dev_data         *dev = inode->u.generic_ip;
1911         int                     value = -EBUSY;
1912
1913         if (dev->state == STATE_DEV_DISABLED) {
1914                 dev->ev_next = 0;
1915                 dev->state = STATE_OPENED;
1916                 fd->private_data = dev;
1917                 get_dev (dev);
1918                 value = 0;
1919         }
1920         return value;
1921 }
1922
1923 static struct file_operations dev_init_operations = {
1924         .owner =        THIS_MODULE,
1925         .llseek =       no_llseek,
1926
1927         .open =         dev_open,
1928         .write =        dev_config,
1929         .fasync =       ep0_fasync,
1930         .ioctl =        dev_ioctl,
1931         .release =      dev_release,
1932 };
1933
1934 /*----------------------------------------------------------------------*/
1935
1936 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1937  *
1938  * Mounting the filesystem creates a controller file, used first for
1939  * device configuration then later for event monitoring.
1940  */
1941
1942
1943 /* FIXME PAM etc could set this security policy without mount options
1944  * if epfiles inherited ownership and permissons from ep0 ...
1945  */
1946
1947 static unsigned default_uid;
1948 static unsigned default_gid;
1949 static unsigned default_perm = S_IRUSR | S_IWUSR;
1950
1951 module_param (default_uid, uint, 0644);
1952 module_param (default_gid, uint, 0644);
1953 module_param (default_perm, uint, 0644);
1954
1955
1956 static struct inode *
1957 gadgetfs_make_inode (struct super_block *sb,
1958                 void *data, const struct file_operations *fops,
1959                 int mode)
1960 {
1961         struct inode *inode = new_inode (sb);
1962
1963         if (inode) {
1964                 inode->i_mode = mode;
1965                 inode->i_uid = default_uid;
1966                 inode->i_gid = default_gid;
1967                 inode->i_blksize = PAGE_CACHE_SIZE;
1968                 inode->i_blocks = 0;
1969                 inode->i_atime = inode->i_mtime = inode->i_ctime
1970                                 = CURRENT_TIME;
1971                 inode->u.generic_ip = data;
1972                 inode->i_fop = fops;
1973         }
1974         return inode;
1975 }
1976
1977 /* creates in fs root directory, so non-renamable and non-linkable.
1978  * so inode and dentry are paired, until device reconfig.
1979  */
1980 static struct inode *
1981 gadgetfs_create_file (struct super_block *sb, char const *name,
1982                 void *data, const struct file_operations *fops,
1983                 struct dentry **dentry_p)
1984 {
1985         struct dentry   *dentry;
1986         struct inode    *inode;
1987
1988         dentry = d_alloc_name(sb->s_root, name);
1989         if (!dentry)
1990                 return NULL;
1991
1992         inode = gadgetfs_make_inode (sb, data, fops,
1993                         S_IFREG | (default_perm & S_IRWXUGO));
1994         if (!inode) {
1995                 dput(dentry);
1996                 return NULL;
1997         }
1998         d_add (dentry, inode);
1999         *dentry_p = dentry;
2000         return inode;
2001 }
2002
2003 static struct super_operations gadget_fs_operations = {
2004         .statfs =       simple_statfs,
2005         .drop_inode =   generic_delete_inode,
2006 };
2007
2008 static int
2009 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2010 {
2011         struct inode    *inode;
2012         struct dentry   *d;
2013         struct dev_data *dev;
2014
2015         if (the_device)
2016                 return -ESRCH;
2017
2018         /* fake probe to determine $CHIP */
2019         (void) usb_gadget_register_driver (&probe_driver);
2020         if (!CHIP)
2021                 return -ENODEV;
2022
2023         /* superblock */
2024         sb->s_blocksize = PAGE_CACHE_SIZE;
2025         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2026         sb->s_magic = GADGETFS_MAGIC;
2027         sb->s_op = &gadget_fs_operations;
2028         sb->s_time_gran = 1;
2029
2030         /* root inode */
2031         inode = gadgetfs_make_inode (sb,
2032                         NULL, &simple_dir_operations,
2033                         S_IFDIR | S_IRUGO | S_IXUGO);
2034         if (!inode)
2035                 return -ENOMEM;
2036         inode->i_op = &simple_dir_inode_operations;
2037         if (!(d = d_alloc_root (inode))) {
2038                 iput (inode);
2039                 return -ENOMEM;
2040         }
2041         sb->s_root = d;
2042
2043         /* the ep0 file is named after the controller we expect;
2044          * user mode code can use it for sanity checks, like we do.
2045          */
2046         dev = dev_new ();
2047         if (!dev)
2048                 return -ENOMEM;
2049
2050         dev->sb = sb;
2051         if (!(inode = gadgetfs_create_file (sb, CHIP,
2052                                 dev, &dev_init_operations,
2053                                 &dev->dentry))) {
2054                 put_dev(dev);
2055                 return -ENOMEM;
2056         }
2057
2058         /* other endpoint files are available after hardware setup,
2059          * from binding to a controller.
2060          */
2061         the_device = dev;
2062         return 0;
2063 }
2064
2065 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2066 static struct super_block *
2067 gadgetfs_get_sb (struct file_system_type *t, int flags,
2068                 const char *path, void *opts)
2069 {
2070         return get_sb_single (t, flags, opts, gadgetfs_fill_super);
2071 }
2072
2073 static void
2074 gadgetfs_kill_sb (struct super_block *sb)
2075 {
2076         kill_litter_super (sb);
2077         if (the_device) {
2078                 put_dev (the_device);
2079                 the_device = NULL;
2080         }
2081 }
2082
2083 /*----------------------------------------------------------------------*/
2084
2085 static struct file_system_type gadgetfs_type = {
2086         .owner          = THIS_MODULE,
2087         .name           = shortname,
2088         .get_sb         = gadgetfs_get_sb,
2089         .kill_sb        = gadgetfs_kill_sb,
2090 };
2091
2092 /*----------------------------------------------------------------------*/
2093
2094 static int __init init (void)
2095 {
2096         int status;
2097
2098         status = register_filesystem (&gadgetfs_type);
2099         if (status == 0)
2100                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2101                         shortname, driver_desc);
2102         return status;
2103 }
2104 module_init (init);
2105
2106 static void __exit cleanup (void)
2107 {
2108         pr_debug ("unregister %s\n", shortname);
2109         unregister_filesystem (&gadgetfs_type);
2110 }
2111 module_exit (cleanup);
2112