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
  13
  14 /* #define VERBOSE_DEBUG */
  15
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/fs.h>
  19 #include <linux/pagemap.h>
  20 #include <linux/uts.h>
  21 #include <linux/wait.h>
  22 #include <linux/compiler.h>
  23 #include <asm/uaccess.h>
  24 #include <linux/sched.h>
  25 #include <linux/slab.h>
  26 #include <linux/poll.h>
  27
  28 #include <linux/device.h>
  29 #include <linux/moduleparam.h>
  30
  31 #include <linux/usb/gadgetfs.h>
  32 #include <linux/usb/gadget.h>
  33
  34
  35 /*
  36  * The gadgetfs API maps each endpoint to a file descriptor so that you
  37  * can use standard synchronous read/write calls for I/O.  There's some
  38  * O_NONBLOCK and O_ASYNC/FASYNC style i/o support.  Example usermode
  39  * drivers show how this works in practice.  You can also use AIO to
  40  * eliminate I/O gaps between requests, to help when streaming data.
  41  *
  42  * Key parts that must be USB-specific are protocols defining how the
  43  * read/write operations relate to the hardware state machines.  There
  44  * are two types of files.  One type is for the device, implementing ep0.
  45  * The other type is for each IN or OUT endpoint.  In both cases, the
  46  * user mode driver must configure the hardware before using it.
  47  *
  48  * - First, dev_config() is called when /dev/gadget/$CHIP is configured
  49  *   (by writing configuration and device descriptors).  Afterwards it
  50  *   may serve as a source of device events, used to handle all control
  51  *   requests other than basic enumeration.
  52  *
  53  * - Then, after a SET_CONFIGURATION control request, ep_config() is
  54  *   called when each /dev/gadget/ep* file is configured (by writing
  55  *   endpoint descriptors).  Afterwards these files are used to write()
  56  *   IN data or to read() OUT data.  To halt the endpoint, a "wrong
  57  *   direction" request is issued (like reading an IN endpoint).
  58  *
  59  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
  60  * not possible on all hardware.  For example, precise fault handling with
  61  * respect to data left in endpoint fifos after aborted operations; or
  62  * selective clearing of endpoint halts, to implement SET_INTERFACE.
  63  */
  64
  65 #define DRIVER_DESC     "USB Gadget filesystem"
  66 #define DRIVER_VERSION  "24 Aug 2004"
  67
  68 static const char driver_desc [] = DRIVER_DESC;
  69 static const char shortname [] = "gadgetfs";
  70
  71 MODULE_DESCRIPTION (DRIVER_DESC);
  72 MODULE_AUTHOR ("David Brownell");
  73 MODULE_LICENSE ("GPL");
  74
  75
  76 /*----------------------------------------------------------------------*/
  77
  78 #define GADGETFS_MAGIC          0xaee71ee7
  79 #define DMA_ADDR_INVALID        (~(dma_addr_t)0)
  80
  81 /* /dev/gadget/$CHIP represents ep0 and the whole device */
  82 enum ep0_state {
  83         /* DISBLED is the initial state.
  84          */
  85         STATE_DEV_DISABLED = 0,
  86
  87         /* Only one open() of /dev/gadget/$CHIP; only one file tracks
  88          * ep0/device i/o modes and binding to the controller.  Driver
  89          * must always write descriptors to initialize the device, then
  90          * the device becomes UNCONNECTED until enumeration.
  91          */
  92         STATE_DEV_OPENED,
  93
  94         /* From then on, ep0 fd is in either of two basic modes:
  95          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
  96          * - SETUP: read/write will transfer control data and succeed;
  97          *   or if "wrong direction", performs protocol stall
  98          */
  99         STATE_DEV_UNCONNECTED,
 100         STATE_DEV_CONNECTED,
 101         STATE_DEV_SETUP,
 102
 103         /* UNBOUND means the driver closed ep0, so the device won't be
 104          * accessible again (DEV_DISABLED) until all fds are closed.
 105          */
 106         STATE_DEV_UNBOUND,
 107 };
 108
 109 /* enough for the whole queue: most events invalidate others */
 110 #define N_EVENT                 5
 111
 112 struct dev_data {
 113         spinlock_t                      lock;
 114         atomic_t                        count;
 115         enum ep0_state                  state;          /* P: lock */
 116         struct usb_gadgetfs_event       event [N_EVENT];
 117         unsigned                        ev_next;
 118         struct fasync_struct            *fasync;
 119         u8                              current_config;
 120
 121         /* drivers reading ep0 MUST handle control requests (SETUP)
 122          * reported that way; else the host will time out.
 123          */
 124         unsigned                        usermode_setup : 1,
 125                                         setup_in : 1,
 126                                         setup_can_stall : 1,
 127                                         setup_out_ready : 1,
 128                                         setup_out_error : 1,
 129                                         setup_abort : 1;
 130         unsigned                        setup_wLength;
 131
 132         /* the rest is basically write-once */
 133         struct usb_config_descriptor    *config, *hs_config;
 134         struct usb_device_descriptor    *dev;
 135         struct usb_request              *req;
 136         struct usb_gadget               *gadget;
 137         struct list_head                epfiles;
 138         void                            *buf;
 139         wait_queue_head_t               wait;
 140         struct super_block              *sb;
 141         struct dentry                   *dentry;
 142
 143         /* except this scratch i/o buffer for ep0 */
 144         u8                              rbuf [256];
 145 };
 146
 147 static inline void get_dev (struct dev_data *data)
 148 {
 149         atomic_inc (&data->count);
 150 }
 151
 152 static void put_dev (struct dev_data *data)
 153 {
 154         if (likely (!atomic_dec_and_test (&data->count)))
 155                 return;
 156         /* needs no more cleanup */
 157         BUG_ON (waitqueue_active (&data->wait));
 158         kfree (data);
 159 }
 160
 161 static struct dev_data *dev_new (void)
 162 {
 163         struct dev_data         *dev;
 164
 165         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 166         if (!dev)
 167                 return NULL;
 168         dev->state = STATE_DEV_DISABLED;
 169         atomic_set (&dev->count, 1);
 170         spin_lock_init (&dev->lock);
 171         INIT_LIST_HEAD (&dev->epfiles);
 172         init_waitqueue_head (&dev->wait);
 173         return dev;
 174 }
 175
 176 /*----------------------------------------------------------------------*/
 177
 178 /* other /dev/gadget/$ENDPOINT files represent endpoints */
 179 enum ep_state {
 180         STATE_EP_DISABLED = 0,
 181         STATE_EP_READY,
 182         STATE_EP_ENABLED,
 183         STATE_EP_UNBOUND,
 184 };
 185
 186 struct ep_data {
 187         struct mutex                    lock;
 188         enum ep_state                   state;
 189         atomic_t                        count;
 190         struct dev_data                 *dev;
 191         /* must hold dev->lock before accessing ep or req */
 192         struct usb_ep                   *ep;
 193         struct usb_request              *req;
 194         ssize_t                         status;
 195         char                            name [16];
 196         struct usb_endpoint_descriptor  desc, hs_desc;
 197         struct list_head                epfiles;
 198         wait_queue_head_t               wait;
 199         struct dentry                   *dentry;
 200         struct inode                    *inode;
 201 };
 202
 203 static inline void get_ep (struct ep_data *data)
 204 {
 205         atomic_inc (&data->count);
 206 }
 207
 208 static void put_ep (struct ep_data *data)
 209 {
 210         if (likely (!atomic_dec_and_test (&data->count)))
 211                 return;
 212         put_dev (data->dev);
 213         /* needs no more cleanup */
 214         BUG_ON (!list_empty (&data->epfiles));
 215         BUG_ON (waitqueue_active (&data->wait));
 216         kfree (data);
 217 }
 218
 219 /*----------------------------------------------------------------------*/
 220
 221 /* most "how to use the hardware" policy choices are in userspace:
 222  * mapping endpoint roles (which the driver needs) to the capabilities
 223  * which the usb controller has.  most of those capabilities are exposed
 224  * implicitly, starting with the driver name and then endpoint names.
 225  */
 226
 227 static const char *CHIP;
 228
 229 /*----------------------------------------------------------------------*/
 230
 231 /* NOTE:  don't use dev_printk calls before binding to the gadget
 232  * at the end of ep0 configuration, or after unbind.
 233  */
 234
 235 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
 236 #define xprintk(d,level,fmt,args...) \
 237         printk(level "%s: " fmt , shortname , ## args)
 238
 239 #ifdef DEBUG
 240 #define DBG(dev,fmt,args...) \
 241         xprintk(dev , KERN_DEBUG , fmt , ## args)
 242 #else
 243 #define DBG(dev,fmt,args...) \
 244         do { } while (0)
 245 #endif /* DEBUG */
 246
 247 #ifdef VERBOSE_DEBUG
 248 #define VDEBUG  DBG
 249 #else
 250 #define VDEBUG(dev,fmt,args...) \
 251         do { } while (0)
 252 #endif /* DEBUG */
 253
 254 #define ERROR(dev,fmt,args...) \
 255         xprintk(dev , KERN_ERR , fmt , ## args)
 256 #define INFO(dev,fmt,args...) \
 257         xprintk(dev , KERN_INFO , fmt , ## args)
 258
 259
 260 /*----------------------------------------------------------------------*/
 261
 262 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 263  *
 264  * After opening, configure non-control endpoints.  Then use normal
 265  * stream read() and write() requests; and maybe ioctl() to get more
 266  * precise FIFO status when recovering from cancellation.
 267  */
 268
 269 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 270 {
 271         struct ep_data  *epdata = ep->driver_data;
 272
 273         if (!req->context)
 274                 return;
 275         if (req->status)
 276                 epdata->status = req->status;
 277         else
 278                 epdata->status = req->actual;
 279         complete ((struct completion *)req->context);
 280 }
 281
 282 /* tasklock endpoint, returning when it's connected.
 283  * still need dev->lock to use epdata->ep.
 284  */
 285 static int
 286 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
 287 {
 288         int     val;
 289
 290         if (f_flags & O_NONBLOCK) {
 291                 if (!mutex_trylock(&epdata->lock))
 292                         goto nonblock;
 293                 if (epdata->state != STATE_EP_ENABLED) {
 294                         mutex_unlock(&epdata->lock);
 295 nonblock:
 296                         val = -EAGAIN;
 297                 } else
 298                         val = 0;
 299                 return val;
 300         }
 301
 302         val = mutex_lock_interruptible(&epdata->lock);
 303         if (val < 0)
 304                 return val;
 305
 306         switch (epdata->state) {
 307         case STATE_EP_ENABLED:
 308                 break;
 309         // case STATE_EP_DISABLED:              /* "can't happen" */
 310         // case STATE_EP_READY:                 /* "can't happen" */
 311         default:                                /* error! */
 312                 pr_debug ("%s: ep %p not available, state %d\n",
 313                                 shortname, epdata, epdata->state);
 314                 // FALLTHROUGH
 315         case STATE_EP_UNBOUND:                  /* clean disconnect */
 316                 val = -ENODEV;
 317                 mutex_unlock(&epdata->lock);
 318         }
 319         return val;
 320 }
 321
 322 static ssize_t
 323 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 324 {
 325         DECLARE_COMPLETION_ONSTACK (done);
 326         int value;
 327
 328         spin_lock_irq (&epdata->dev->lock);
 329         if (likely (epdata->ep != NULL)) {
 330                 struct usb_request      *req = epdata->req;
 331
 332                 req->context = &done;
 333                 req->complete = epio_complete;
 334                 req->buf = buf;
 335                 req->length = len;
 336                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 337         } else
 338                 value = -ENODEV;
 339         spin_unlock_irq (&epdata->dev->lock);
 340
 341         if (likely (value == 0)) {
 342                 value = wait_event_interruptible (done.wait, done.done);
 343                 if (value != 0) {
 344                         spin_lock_irq (&epdata->dev->lock);
 345                         if (likely (epdata->ep != NULL)) {
 346                                 DBG (epdata->dev, "%s i/o interrupted\n",
 347                                                 epdata->name);
 348                                 usb_ep_dequeue (epdata->ep, epdata->req);
 349                                 spin_unlock_irq (&epdata->dev->lock);
 350
 351                                 wait_event (done.wait, done.done);
 352                                 if (epdata->status == -ECONNRESET)
 353                                         epdata->status = -EINTR;
 354                         } else {
 355                                 spin_unlock_irq (&epdata->dev->lock);
 356
 357                                 DBG (epdata->dev, "endpoint gone\n");
 358                                 epdata->status = -ENODEV;
 359                         }
 360                 }
 361                 return epdata->status;
 362         }
 363         return value;
 364 }
 365
 366
 367 /* handle a synchronous OUT bulk/intr/iso transfer */
 368 static ssize_t
 369 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 370 {
 371         struct ep_data          *data = fd->private_data;
 372         void                    *kbuf;
 373         ssize_t                 value;
 374
 375         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 376                 return value;
 377
 378         /* halt any endpoint by doing a "wrong direction" i/o call */
 379         if (usb_endpoint_dir_in(&data->desc)) {
 380                 if (usb_endpoint_xfer_isoc(&data->desc)) {
 381                         mutex_unlock(&data->lock);
 382                         return -EINVAL;
 383                 }
 384                 DBG (data->dev, "%s halt\n", data->name);
 385                 spin_lock_irq (&data->dev->lock);
 386                 if (likely (data->ep != NULL))
 387                         usb_ep_set_halt (data->ep);
 388                 spin_unlock_irq (&data->dev->lock);
 389                 mutex_unlock(&data->lock);
 390                 return -EBADMSG;
 391         }
 392
 393         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
 394
 395         value = -ENOMEM;
 396         kbuf = kmalloc (len, GFP_KERNEL);
 397         if (unlikely (!kbuf))
 398                 goto free1;
 399
 400         value = ep_io (data, kbuf, len);
 401         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
 402                 data->name, len, (int) value);
 403         if (value >= 0 && copy_to_user (buf, kbuf, value))
 404                 value = -EFAULT;
 405
 406 free1:
 407         mutex_unlock(&data->lock);
 408         kfree (kbuf);
 409         return value;
 410 }
 411
 412 /* handle a synchronous IN bulk/intr/iso transfer */
 413 static ssize_t
 414 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 415 {
 416         struct ep_data          *data = fd->private_data;
 417         void                    *kbuf;
 418         ssize_t                 value;
 419
 420         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 421                 return value;
 422
 423         /* halt any endpoint by doing a "wrong direction" i/o call */
 424         if (!usb_endpoint_dir_in(&data->desc)) {
 425                 if (usb_endpoint_xfer_isoc(&data->desc)) {
 426                         mutex_unlock(&data->lock);
 427                         return -EINVAL;
 428                 }
 429                 DBG (data->dev, "%s halt\n", data->name);
 430                 spin_lock_irq (&data->dev->lock);
 431                 if (likely (data->ep != NULL))
 432                         usb_ep_set_halt (data->ep);
 433                 spin_unlock_irq (&data->dev->lock);
 434                 mutex_unlock(&data->lock);
 435                 return -EBADMSG;
 436         }
 437
 438         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
 439
 440         value = -ENOMEM;
 441         kbuf = kmalloc (len, GFP_KERNEL);
 442         if (!kbuf)
 443                 goto free1;
 444         if (copy_from_user (kbuf, buf, len)) {
 445                 value = -EFAULT;
 446                 goto free1;
 447         }
 448
 449         value = ep_io (data, kbuf, len);
 450         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
 451                 data->name, len, (int) value);
 452 free1:
 453         mutex_unlock(&data->lock);
 454         kfree (kbuf);
 455         return value;
 456 }
 457
 458 static int
 459 ep_release (struct inode *inode, struct file *fd)
 460 {
 461         struct ep_data          *data = fd->private_data;
 462         int value;
 463
 464         value = mutex_lock_interruptible(&data->lock);
 465         if (value < 0)
 466                 return value;
 467
 468         /* clean up if this can be reopened */
 469         if (data->state != STATE_EP_UNBOUND) {
 470                 data->state = STATE_EP_DISABLED;
 471                 data->desc.bDescriptorType = 0;
 472                 data->hs_desc.bDescriptorType = 0;
 473                 usb_ep_disable(data->ep);
 474         }
 475         mutex_unlock(&data->lock);
 476         put_ep (data);
 477         return 0;
 478 }
 479
 480 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
 481 {
 482         struct ep_data          *data = fd->private_data;
 483         int                     status;
 484
 485         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 486                 return status;
 487
 488         spin_lock_irq (&data->dev->lock);
 489         if (likely (data->ep != NULL)) {
 490                 switch (code) {
 491                 case GADGETFS_FIFO_STATUS:
 492                         status = usb_ep_fifo_status (data->ep);
 493                         break;
 494                 case GADGETFS_FIFO_FLUSH:
 495                         usb_ep_fifo_flush (data->ep);
 496                         break;
 497                 case GADGETFS_CLEAR_HALT:
 498                         status = usb_ep_clear_halt (data->ep);
 499                         break;
 500                 default:
 501                         status = -ENOTTY;
 502                 }
 503         } else
 504                 status = -ENODEV;
 505         spin_unlock_irq (&data->dev->lock);
 506         mutex_unlock(&data->lock);
 507         return status;
 508 }
 509
 510 /*----------------------------------------------------------------------*/
 511
 512 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 513
 514 struct kiocb_priv {
 515         struct usb_request      *req;
 516         struct ep_data          *epdata;
 517         void                    *buf;
 518         const struct iovec      *iv;
 519         unsigned long           nr_segs;
 520         unsigned                actual;
 521 };
 522
 523 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
 524 {
 525         struct kiocb_priv       *priv = iocb->private;
 526         struct ep_data          *epdata;
 527         int                     value;
 528
 529         local_irq_disable();
 530         epdata = priv->epdata;
 531         // spin_lock(&epdata->dev->lock);
 532         kiocbSetCancelled(iocb);
 533         if (likely(epdata && epdata->ep && priv->req))
 534                 value = usb_ep_dequeue (epdata->ep, priv->req);
 535         else
 536                 value = -EINVAL;
 537         // spin_unlock(&epdata->dev->lock);
 538         local_irq_enable();
 539
 540         aio_put_req(iocb);
 541         return value;
 542 }
 543
 544 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
 545 {
 546         struct kiocb_priv       *priv = iocb->private;
 547         ssize_t                 len, total;
 548         void                    *to_copy;
 549         int                     i;
 550
 551         /* we "retry" to get the right mm context for this: */
 552
 553         /* copy stuff into user buffers */
 554         total = priv->actual;
 555         len = 0;
 556         to_copy = priv->buf;
 557         for (i=0; i < priv->nr_segs; i++) {
 558                 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
 559
 560                 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
 561                         if (len == 0)
 562                                 len = -EFAULT;
 563                         break;
 564                 }
 565
 566                 total -= this;
 567                 len += this;
 568                 to_copy += this;
 569                 if (total == 0)
 570                         break;
 571         }
 572         kfree(priv->buf);
 573         kfree(priv);
 574         return len;
 575 }
 576
 577 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 578 {
 579         struct kiocb            *iocb = req->context;
 580         struct kiocb_priv       *priv = iocb->private;
 581         struct ep_data          *epdata = priv->epdata;
 582
 583         /* lock against disconnect (and ideally, cancel) */
 584         spin_lock(&epdata->dev->lock);
 585         priv->req = NULL;
 586         priv->epdata = NULL;
 587
 588         /* if this was a write or a read returning no data then we
 589          * don't need to copy anything to userspace, so we can
 590          * complete the aio request immediately.
 591          */
 592         if (priv->iv == NULL || unlikely(req->actual == 0)) {
 593                 kfree(req->buf);
 594                 kfree(priv);
 595                 iocb->private = NULL;
 596                 /* aio_complete() reports bytes-transferred _and_ faults */
 597                 aio_complete(iocb, req->actual ? req->actual : req->status,
 598                                 req->status);
 599         } else {
 600                 /* retry() won't report both; so we hide some faults */
 601                 if (unlikely(0 != req->status))
 602                         DBG(epdata->dev, "%s fault %d len %d\n",
 603                                 ep->name, req->status, req->actual);
 604
 605                 priv->buf = req->buf;
 606                 priv->actual = req->actual;
 607                 kick_iocb(iocb);
 608         }
 609         spin_unlock(&epdata->dev->lock);
 610
 611         usb_ep_free_request(ep, req);
 612         put_ep(epdata);
 613 }
 614
 615 static ssize_t
 616 ep_aio_rwtail(
 617         struct kiocb    *iocb,
 618         char            *buf,
 619         size_t          len,
 620         struct ep_data  *epdata,
 621         const struct iovec *iv,
 622         unsigned long   nr_segs
 623 )
 624 {
 625         struct kiocb_priv       *priv;
 626         struct usb_request      *req;
 627         ssize_t                 value;
 628
 629         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 630         if (!priv) {
 631                 value = -ENOMEM;
 632 fail:
 633                 kfree(buf);
 634                 return value;
 635         }
 636         iocb->private = priv;
 637         priv->iv = iv;
 638         priv->nr_segs = nr_segs;
 639
 640         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 641         if (unlikely(value < 0)) {
 642                 kfree(priv);
 643                 goto fail;
 644         }
 645
 646         iocb->ki_cancel = ep_aio_cancel;
 647         get_ep(epdata);
 648         priv->epdata = epdata;
 649         priv->actual = 0;
 650
 651         /* each kiocb is coupled to one usb_request, but we can't
 652          * allocate or submit those if the host disconnected.
 653          */
 654         spin_lock_irq(&epdata->dev->lock);
 655         if (likely(epdata->ep)) {
 656                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 657                 if (likely(req)) {
 658                         priv->req = req;
 659                         req->buf = buf;
 660                         req->length = len;
 661                         req->complete = ep_aio_complete;
 662                         req->context = iocb;
 663                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 664                         if (unlikely(0 != value))
 665                                 usb_ep_free_request(epdata->ep, req);
 666                 } else
 667                         value = -EAGAIN;
 668         } else
 669                 value = -ENODEV;
 670         spin_unlock_irq(&epdata->dev->lock);
 671
 672         mutex_unlock(&epdata->lock);
 673
 674         if (unlikely(value)) {
 675                 kfree(priv);
 676                 put_ep(epdata);
 677         } else
 678                 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
 679         return value;
 680 }
 681
 682 static ssize_t
 683 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
 684                 unsigned long nr_segs, loff_t o)
 685 {
 686         struct ep_data          *epdata = iocb->ki_filp->private_data;
 687         char                    *buf;
 688
 689         if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
 690                 return -EINVAL;
 691
 692         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 693         if (unlikely(!buf))
 694                 return -ENOMEM;
 695
 696         iocb->ki_retry = ep_aio_read_retry;
 697         return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
 698 }
 699
 700 static ssize_t
 701 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
 702                 unsigned long nr_segs, loff_t o)
 703 {
 704         struct ep_data          *epdata = iocb->ki_filp->private_data;
 705         char                    *buf;
 706         size_t                  len = 0;
 707         int                     i = 0;
 708
 709         if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
 710                 return -EINVAL;
 711
 712         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 713         if (unlikely(!buf))
 714                 return -ENOMEM;
 715
 716         for (i=0; i < nr_segs; i++) {
 717                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
 718                                 iov[i].iov_len) != 0)) {
 719                         kfree(buf);
 720                         return -EFAULT;
 721                 }
 722                 len += iov[i].iov_len;
 723         }
 724         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
 725 }
 726
 727 /*----------------------------------------------------------------------*/
 728
 729 /* used after endpoint configuration */
 730 static const struct file_operations ep_io_operations = {
 731         .owner =        THIS_MODULE,
 732         .llseek =       no_llseek,
 733
 734         .read =         ep_read,
 735         .write =        ep_write,
 736         .unlocked_ioctl = ep_ioctl,
 737         .release =      ep_release,
 738
 739         .aio_read =     ep_aio_read,
 740         .aio_write =    ep_aio_write,
 741 };
 742
 743 /* ENDPOINT INITIALIZATION
 744  *
 745  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 746  *     status = write (fd, descriptors, sizeof descriptors)
 747  *
 748  * That write establishes the endpoint configuration, configuring
 749  * the controller to process bulk, interrupt, or isochronous transfers
 750  * at the right maxpacket size, and so on.
 751  *
 752  * The descriptors are message type 1, identified by a host order u32
 753  * at the beginning of what's written.  Descriptor order is: full/low
 754  * speed descriptor, then optional high speed descriptor.
 755  */
 756 static ssize_t
 757 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 758 {
 759         struct ep_data          *data = fd->private_data;
 760         struct usb_ep           *ep;
 761         u32                     tag;
 762         int                     value, length = len;
 763
 764         value = mutex_lock_interruptible(&data->lock);
 765         if (value < 0)
 766                 return value;
 767
 768         if (data->state != STATE_EP_READY) {
 769                 value = -EL2HLT;
 770                 goto fail;
 771         }
 772
 773         value = len;
 774         if (len < USB_DT_ENDPOINT_SIZE + 4)
 775                 goto fail0;
 776
 777         /* we might need to change message format someday */
 778         if (copy_from_user (&tag, buf, 4)) {
 779                 goto fail1;
 780         }
 781         if (tag != 1) {
 782                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 783                 goto fail0;
 784         }
 785         buf += 4;
 786         len -= 4;
 787
 788         /* NOTE:  audio endpoint extensions not accepted here;
 789          * just don't include the extra bytes.
 790          */
 791
 792         /* full/low speed descriptor, then high speed */
 793         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 794                 goto fail1;
 795         }
 796         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 797                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 798                 goto fail0;
 799         if (len != USB_DT_ENDPOINT_SIZE) {
 800                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 801                         goto fail0;
 802                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 803                                         USB_DT_ENDPOINT_SIZE)) {
 804                         goto fail1;
 805                 }
 806                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 807                                 || data->hs_desc.bDescriptorType
 808                                         != USB_DT_ENDPOINT) {
 809                         DBG(data->dev, "config %s, bad hs length or type\n",
 810                                         data->name);
 811                         goto fail0;
 812                 }
 813         }
 814
 815         spin_lock_irq (&data->dev->lock);
 816         if (data->dev->state == STATE_DEV_UNBOUND) {
 817                 value = -ENOENT;
 818                 goto gone;
 819         } else if ((ep = data->ep) == NULL) {
 820                 value = -ENODEV;
 821                 goto gone;
 822         }
 823         switch (data->dev->gadget->speed) {
 824         case USB_SPEED_LOW:
 825         case USB_SPEED_FULL:
 826                 ep->desc = &data->desc;
 827                 value = usb_ep_enable(ep);
 828                 if (value == 0)
 829                         data->state = STATE_EP_ENABLED;
 830                 break;
 831         case USB_SPEED_HIGH:
 832                 /* fails if caller didn't provide that descriptor... */
 833                 ep->desc = &data->hs_desc;
 834                 value = usb_ep_enable(ep);
 835                 if (value == 0)
 836                         data->state = STATE_EP_ENABLED;
 837                 break;
 838         default:
 839                 DBG(data->dev, "unconnected, %s init abandoned\n",
 840                                 data->name);
 841                 value = -EINVAL;
 842         }
 843         if (value == 0) {
 844                 fd->f_op = &ep_io_operations;
 845                 value = length;
 846         }
 847 gone:
 848         spin_unlock_irq (&data->dev->lock);
 849         if (value < 0) {
 850 fail:
 851                 data->desc.bDescriptorType = 0;
 852                 data->hs_desc.bDescriptorType = 0;
 853         }
 854         mutex_unlock(&data->lock);
 855         return value;
 856 fail0:
 857         value = -EINVAL;
 858         goto fail;
 859 fail1:
 860         value = -EFAULT;
 861         goto fail;
 862 }
 863
 864 static int
 865 ep_open (struct inode *inode, struct file *fd)
 866 {
 867         struct ep_data          *data = inode->i_private;
 868         int                     value = -EBUSY;
 869
 870         if (mutex_lock_interruptible(&data->lock) != 0)
 871                 return -EINTR;
 872         spin_lock_irq (&data->dev->lock);
 873         if (data->dev->state == STATE_DEV_UNBOUND)
 874                 value = -ENOENT;
 875         else if (data->state == STATE_EP_DISABLED) {
 876                 value = 0;
 877                 data->state = STATE_EP_READY;
 878                 get_ep (data);
 879                 fd->private_data = data;
 880                 VDEBUG (data->dev, "%s ready\n", data->name);
 881         } else
 882                 DBG (data->dev, "%s state %d\n",
 883                         data->name, data->state);
 884         spin_unlock_irq (&data->dev->lock);
 885         mutex_unlock(&data->lock);
 886         return value;
 887 }
 888
 889 /* used before endpoint configuration */
 890 static const struct file_operations ep_config_operations = {
 891         .owner =        THIS_MODULE,
 892         .llseek =       no_llseek,
 893
 894         .open =         ep_open,
 895         .write =        ep_config,
 896         .release =      ep_release,
 897 };
 898
 899 /*----------------------------------------------------------------------*/
 900
 901 /* EP0 IMPLEMENTATION can be partly in userspace.
 902  *
 903  * Drivers that use this facility receive various events, including
 904  * control requests the kernel doesn't handle.  Drivers that don't
 905  * use this facility may be too simple-minded for real applications.
 906  */
 907
 908 static inline void ep0_readable (struct dev_data *dev)
 909 {
 910         wake_up (&dev->wait);
 911         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 912 }
 913
 914 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 915 {
 916         struct dev_data         *dev = ep->driver_data;
 917
 918         if (req->buf != dev->rbuf) {
 919                 kfree(req->buf);
 920                 req->buf = dev->rbuf;
 921                 req->dma = DMA_ADDR_INVALID;
 922         }
 923         req->complete = epio_complete;
 924         dev->setup_out_ready = 0;
 925 }
 926
 927 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 928 {
 929         struct dev_data         *dev = ep->driver_data;
 930         unsigned long           flags;
 931         int                     free = 1;
 932
 933         /* for control OUT, data must still get to userspace */
 934         spin_lock_irqsave(&dev->lock, flags);
 935         if (!dev->setup_in) {
 936                 dev->setup_out_error = (req->status != 0);
 937                 if (!dev->setup_out_error)
 938                         free = 0;
 939                 dev->setup_out_ready = 1;
 940                 ep0_readable (dev);
 941         }
 942
 943         /* clean up as appropriate */
 944         if (free && req->buf != &dev->rbuf)
 945                 clean_req (ep, req);
 946         req->complete = epio_complete;
 947         spin_unlock_irqrestore(&dev->lock, flags);
 948 }
 949
 950 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 951 {
 952         struct dev_data *dev = ep->driver_data;
 953
 954         if (dev->setup_out_ready) {
 955                 DBG (dev, "ep0 request busy!\n");
 956                 return -EBUSY;
 957         }
 958         if (len > sizeof (dev->rbuf))
 959                 req->buf = kmalloc(len, GFP_ATOMIC);
 960         if (req->buf == NULL) {
 961                 req->buf = dev->rbuf;
 962                 return -ENOMEM;
 963         }
 964         req->complete = ep0_complete;
 965         req->length = len;
 966         req->zero = 0;
 967         return 0;
 968 }
 969
 970 static ssize_t
 971 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 972 {
 973         struct dev_data                 *dev = fd->private_data;
 974         ssize_t                         retval;
 975         enum ep0_state                  state;
 976
 977         spin_lock_irq (&dev->lock);
 978
 979         /* report fd mode change before acting on it */
 980         if (dev->setup_abort) {
 981                 dev->setup_abort = 0;
 982                 retval = -EIDRM;
 983                 goto done;
 984         }
 985
 986         /* control DATA stage */
 987         if ((state = dev->state) == STATE_DEV_SETUP) {
 988
 989                 if (dev->setup_in) {            /* stall IN */
 990                         VDEBUG(dev, "ep0in stall\n");
 991                         (void) usb_ep_set_halt (dev->gadget->ep0);
 992                         retval = -EL2HLT;
 993                         dev->state = STATE_DEV_CONNECTED;
 994
 995                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
 996                         struct usb_ep           *ep = dev->gadget->ep0;
 997                         struct usb_request      *req = dev->req;
 998
 999                         if ((retval = setup_req (ep, req, 0)) == 0)
1000                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1001                         dev->state = STATE_DEV_CONNECTED;
1002
1003                         /* assume that was SET_CONFIGURATION */
1004                         if (dev->current_config) {
1005                                 unsigned power;
1006
1007                                 if (gadget_is_dualspeed(dev->gadget)
1008                                                 && (dev->gadget->speed
1009                                                         == USB_SPEED_HIGH))
1010                                         power = dev->hs_config->bMaxPower;
1011                                 else
1012                                         power = dev->config->bMaxPower;
1013                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1014                         }
1015
1016                 } else {                        /* collect OUT data */
1017                         if ((fd->f_flags & O_NONBLOCK) != 0
1018                                         && !dev->setup_out_ready) {
1019                                 retval = -EAGAIN;
1020                                 goto done;
1021                         }
1022                         spin_unlock_irq (&dev->lock);
1023                         retval = wait_event_interruptible (dev->wait,
1024                                         dev->setup_out_ready != 0);
1025
1026                         /* FIXME state could change from under us */
1027                         spin_lock_irq (&dev->lock);
1028                         if (retval)
1029                                 goto done;
1030
1031                         if (dev->state != STATE_DEV_SETUP) {
1032                                 retval = -ECANCELED;
1033                                 goto done;
1034                         }
1035                         dev->state = STATE_DEV_CONNECTED;
1036
1037                         if (dev->setup_out_error)
1038                                 retval = -EIO;
1039                         else {
1040                                 len = min (len, (size_t)dev->req->actual);
1041 // FIXME don't call this with the spinlock held ...
1042                                 if (copy_to_user (buf, dev->req->buf, len))
1043                                         retval = -EFAULT;
1044                                 else
1045                                         retval = len;
1046                                 clean_req (dev->gadget->ep0, dev->req);
1047                                 /* NOTE userspace can't yet choose to stall */
1048                         }
1049                 }
1050                 goto done;
1051         }
1052
1053         /* else normal: return event data */
1054         if (len < sizeof dev->event [0]) {
1055                 retval = -EINVAL;
1056                 goto done;
1057         }
1058         len -= len % sizeof (struct usb_gadgetfs_event);
1059         dev->usermode_setup = 1;
1060
1061 scan:
1062         /* return queued events right away */
1063         if (dev->ev_next != 0) {
1064                 unsigned                i, n;
1065
1066                 n = len / sizeof (struct usb_gadgetfs_event);
1067                 if (dev->ev_next < n)
1068                         n = dev->ev_next;
1069
1070                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1071                 for (i = 0; i < n; i++) {
1072                         if (dev->event [i].type == GADGETFS_SETUP) {
1073                                 dev->state = STATE_DEV_SETUP;
1074                                 n = i + 1;
1075                                 break;
1076                         }
1077                 }
1078                 spin_unlock_irq (&dev->lock);
1079                 len = n * sizeof (struct usb_gadgetfs_event);
1080                 if (copy_to_user (buf, &dev->event, len))
1081                         retval = -EFAULT;
1082                 else
1083                         retval = len;
1084                 if (len > 0) {
1085                         /* NOTE this doesn't guard against broken drivers;
1086                          * concurrent ep0 readers may lose events.
1087                          */
1088                         spin_lock_irq (&dev->lock);
1089                         if (dev->ev_next > n) {
1090                                 memmove(&dev->event[0], &dev->event[n],
1091                                         sizeof (struct usb_gadgetfs_event)
1092                                                 * (dev->ev_next - n));
1093                         }
1094                         dev->ev_next -= n;
1095                         spin_unlock_irq (&dev->lock);
1096                 }
1097                 return retval;
1098         }
1099         if (fd->f_flags & O_NONBLOCK) {
1100                 retval = -EAGAIN;
1101                 goto done;
1102         }
1103
1104         switch (state) {
1105         default:
1106                 DBG (dev, "fail %s, state %d\n", __func__, state);
1107                 retval = -ESRCH;
1108                 break;
1109         case STATE_DEV_UNCONNECTED:
1110         case STATE_DEV_CONNECTED:
1111                 spin_unlock_irq (&dev->lock);
1112                 DBG (dev, "%s wait\n", __func__);
1113
1114                 /* wait for events */
1115                 retval = wait_event_interruptible (dev->wait,
1116                                 dev->ev_next != 0);
1117                 if (retval < 0)
1118                         return retval;
1119                 spin_lock_irq (&dev->lock);
1120                 goto scan;
1121         }
1122
1123 done:
1124         spin_unlock_irq (&dev->lock);
1125         return retval;
1126 }
1127
1128 static struct usb_gadgetfs_event *
1129 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1130 {
1131         struct usb_gadgetfs_event       *event;
1132         unsigned                        i;
1133
1134         switch (type) {
1135         /* these events purge the queue */
1136         case GADGETFS_DISCONNECT:
1137                 if (dev->state == STATE_DEV_SETUP)
1138                         dev->setup_abort = 1;
1139                 // FALL THROUGH
1140         case GADGETFS_CONNECT:
1141                 dev->ev_next = 0;
1142                 break;
1143         case GADGETFS_SETUP:            /* previous request timed out */
1144         case GADGETFS_SUSPEND:          /* same effect */
1145                 /* these events can't be repeated */
1146                 for (i = 0; i != dev->ev_next; i++) {
1147                         if (dev->event [i].type != type)
1148                                 continue;
1149                         DBG(dev, "discard old event[%d] %d\n", i, type);
1150                         dev->ev_next--;
1151                         if (i == dev->ev_next)
1152                                 break;
1153                         /* indices start at zero, for simplicity */
1154                         memmove (&dev->event [i], &dev->event [i + 1],
1155                                 sizeof (struct usb_gadgetfs_event)
1156                                         * (dev->ev_next - i));
1157                 }
1158                 break;
1159         default:
1160                 BUG ();
1161         }
1162         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1163         event = &dev->event [dev->ev_next++];
1164         BUG_ON (dev->ev_next > N_EVENT);
1165         memset (event, 0, sizeof *event);
1166         event->type = type;
1167         return event;
1168 }
1169
1170 static ssize_t
1171 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1172 {
1173         struct dev_data         *dev = fd->private_data;
1174         ssize_t                 retval = -ESRCH;
1175
1176         spin_lock_irq (&dev->lock);
1177
1178         /* report fd mode change before acting on it */
1179         if (dev->setup_abort) {
1180                 dev->setup_abort = 0;
1181                 retval = -EIDRM;
1182
1183         /* data and/or status stage for control request */
1184         } else if (dev->state == STATE_DEV_SETUP) {
1185
1186                 /* IN DATA+STATUS caller makes len <= wLength */
1187                 if (dev->setup_in) {
1188                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1189                         if (retval == 0) {
1190                                 dev->state = STATE_DEV_CONNECTED;
1191                                 spin_unlock_irq (&dev->lock);
1192                                 if (copy_from_user (dev->req->buf, buf, len))
1193                                         retval = -EFAULT;
1194                                 else {
1195                                         if (len < dev->setup_wLength)
1196                                                 dev->req->zero = 1;
1197                                         retval = usb_ep_queue (
1198                                                 dev->gadget->ep0, dev->req,
1199                                                 GFP_KERNEL);
1200                                 }
1201                                 if (retval < 0) {
1202                                         spin_lock_irq (&dev->lock);
1203                                         clean_req (dev->gadget->ep0, dev->req);
1204                                         spin_unlock_irq (&dev->lock);
1205                                 } else
1206                                         retval = len;
1207
1208                                 return retval;
1209                         }
1210
1211                 /* can stall some OUT transfers */
1212                 } else if (dev->setup_can_stall) {
1213                         VDEBUG(dev, "ep0out stall\n");
1214                         (void) usb_ep_set_halt (dev->gadget->ep0);
1215                         retval = -EL2HLT;
1216                         dev->state = STATE_DEV_CONNECTED;
1217                 } else {
1218                         DBG(dev, "bogus ep0out stall!\n");
1219                 }
1220         } else
1221                 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1222
1223         spin_unlock_irq (&dev->lock);
1224         return retval;
1225 }
1226
1227 static int
1228 ep0_fasync (int f, struct file *fd, int on)
1229 {
1230         struct dev_data         *dev = fd->private_data;
1231         // caller must F_SETOWN before signal delivery happens
1232         VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1233         return fasync_helper (f, fd, on, &dev->fasync);
1234 }
1235
1236 static struct usb_gadget_driver gadgetfs_driver;
1237
1238 static int
1239 dev_release (struct inode *inode, struct file *fd)
1240 {
1241         struct dev_data         *dev = fd->private_data;
1242
1243         /* closing ep0 === shutdown all */
1244
1245         usb_gadget_unregister_driver (&gadgetfs_driver);
1246
1247         /* at this point "good" hardware has disconnected the
1248          * device from USB; the host won't see it any more.
1249          * alternatively, all host requests will time out.
1250          */
1251
1252         kfree (dev->buf);
1253         dev->buf = NULL;
1254         put_dev (dev);
1255
1256         /* other endpoints were all decoupled from this device */
1257         spin_lock_irq(&dev->lock);
1258         dev->state = STATE_DEV_DISABLED;
1259         spin_unlock_irq(&dev->lock);
1260         return 0;
1261 }
1262
1263 static unsigned int
1264 ep0_poll (struct file *fd, poll_table *wait)
1265 {
1266        struct dev_data         *dev = fd->private_data;
1267        int                     mask = 0;
1268
1269        poll_wait(fd, &dev->wait, wait);
1270
1271        spin_lock_irq (&dev->lock);
1272
1273        /* report fd mode change before acting on it */
1274        if (dev->setup_abort) {
1275                dev->setup_abort = 0;
1276                mask = POLLHUP;
1277                goto out;
1278        }
1279
1280        if (dev->state == STATE_DEV_SETUP) {
1281                if (dev->setup_in || dev->setup_can_stall)
1282                        mask = POLLOUT;
1283        } else {
1284                if (dev->ev_next != 0)
1285                        mask = POLLIN;
1286        }
1287 out:
1288        spin_unlock_irq(&dev->lock);
1289        return mask;
1290 }
1291
1292 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1293 {
1294         struct dev_data         *dev = fd->private_data;
1295         struct usb_gadget       *gadget = dev->gadget;
1296         long ret = -ENOTTY;
1297
1298         if (gadget->ops->ioctl)
1299                 ret = gadget->ops->ioctl (gadget, code, value);
1300
1301         return ret;
1302 }
1303
1304 /* used after device configuration */
1305 static const struct file_operations ep0_io_operations = {
1306         .owner =        THIS_MODULE,
1307         .llseek =       no_llseek,
1308
1309         .read =         ep0_read,
1310         .write =        ep0_write,
1311         .fasync =       ep0_fasync,
1312         .poll =         ep0_poll,
1313         .unlocked_ioctl =       dev_ioctl,
1314         .release =      dev_release,
1315 };
1316
1317 /*----------------------------------------------------------------------*/
1318
1319 /* The in-kernel gadget driver handles most ep0 issues, in particular
1320  * enumerating the single configuration (as provided from user space).
1321  *
1322  * Unrecognized ep0 requests may be handled in user space.
1323  */
1324
1325 static void make_qualifier (struct dev_data *dev)
1326 {
1327         struct usb_qualifier_descriptor         qual;
1328         struct usb_device_descriptor            *desc;
1329
1330         qual.bLength = sizeof qual;
1331         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1332         qual.bcdUSB = cpu_to_le16 (0x0200);
1333
1334         desc = dev->dev;
1335         qual.bDeviceClass = desc->bDeviceClass;
1336         qual.bDeviceSubClass = desc->bDeviceSubClass;
1337         qual.bDeviceProtocol = desc->bDeviceProtocol;
1338
1339         /* assumes ep0 uses the same value for both speeds ... */
1340         qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1341
1342         qual.bNumConfigurations = 1;
1343         qual.bRESERVED = 0;
1344
1345         memcpy (dev->rbuf, &qual, sizeof qual);
1346 }
1347
1348 static int
1349 config_buf (struct dev_data *dev, u8 type, unsigned index)
1350 {
1351         int             len;
1352         int             hs = 0;
1353
1354         /* only one configuration */
1355         if (index > 0)
1356                 return -EINVAL;
1357
1358         if (gadget_is_dualspeed(dev->gadget)) {
1359                 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1360                 if (type == USB_DT_OTHER_SPEED_CONFIG)
1361                         hs = !hs;
1362         }
1363         if (hs) {
1364                 dev->req->buf = dev->hs_config;
1365                 len = le16_to_cpu(dev->hs_config->wTotalLength);
1366         } else {
1367                 dev->req->buf = dev->config;
1368                 len = le16_to_cpu(dev->config->wTotalLength);
1369         }
1370         ((u8 *)dev->req->buf) [1] = type;
1371         return len;
1372 }
1373
1374 static int
1375 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1376 {
1377         struct dev_data                 *dev = get_gadget_data (gadget);
1378         struct usb_request              *req = dev->req;
1379         int                             value = -EOPNOTSUPP;
1380         struct usb_gadgetfs_event       *event;
1381         u16                             w_value = le16_to_cpu(ctrl->wValue);
1382         u16                             w_length = le16_to_cpu(ctrl->wLength);
1383
1384         spin_lock (&dev->lock);
1385         dev->setup_abort = 0;
1386         if (dev->state == STATE_DEV_UNCONNECTED) {
1387                 if (gadget_is_dualspeed(gadget)
1388                                 && gadget->speed == USB_SPEED_HIGH
1389                                 && dev->hs_config == NULL) {
1390                         spin_unlock(&dev->lock);
1391                         ERROR (dev, "no high speed config??\n");
1392                         return -EINVAL;
1393                 }
1394
1395                 dev->state = STATE_DEV_CONNECTED;
1396
1397                 INFO (dev, "connected\n");
1398                 event = next_event (dev, GADGETFS_CONNECT);
1399                 event->u.speed = gadget->speed;
1400                 ep0_readable (dev);
1401
1402         /* host may have given up waiting for response.  we can miss control
1403          * requests handled lower down (device/endpoint status and features);
1404          * then ep0_{read,write} will report the wrong status. controller
1405          * driver will have aborted pending i/o.
1406          */
1407         } else if (dev->state == STATE_DEV_SETUP)
1408                 dev->setup_abort = 1;
1409
1410         req->buf = dev->rbuf;
1411         req->dma = DMA_ADDR_INVALID;
1412         req->context = NULL;
1413         value = -EOPNOTSUPP;
1414         switch (ctrl->bRequest) {
1415
1416         case USB_REQ_GET_DESCRIPTOR:
1417                 if (ctrl->bRequestType != USB_DIR_IN)
1418                         goto unrecognized;
1419                 switch (w_value >> 8) {
1420
1421                 case USB_DT_DEVICE:
1422                         value = min (w_length, (u16) sizeof *dev->dev);
1423                         dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1424                         req->buf = dev->dev;
1425                         break;
1426                 case USB_DT_DEVICE_QUALIFIER:
1427                         if (!dev->hs_config)
1428                                 break;
1429                         value = min (w_length, (u16)
1430                                 sizeof (struct usb_qualifier_descriptor));
1431                         make_qualifier (dev);
1432                         break;
1433                 case USB_DT_OTHER_SPEED_CONFIG:
1434                         // FALLTHROUGH
1435                 case USB_DT_CONFIG:
1436                         value = config_buf (dev,
1437                                         w_value >> 8,
1438                                         w_value & 0xff);
1439                         if (value >= 0)
1440                                 value = min (w_length, (u16) value);
1441                         break;
1442                 case USB_DT_STRING:
1443                         goto unrecognized;
1444
1445                 default:                // all others are errors
1446                         break;
1447                 }
1448                 break;
1449
1450         /* currently one config, two speeds */
1451         case USB_REQ_SET_CONFIGURATION:
1452                 if (ctrl->bRequestType != 0)
1453                         goto unrecognized;
1454                 if (0 == (u8) w_value) {
1455                         value = 0;
1456                         dev->current_config = 0;
1457                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1458                         // user mode expected to disable endpoints
1459                 } else {
1460                         u8      config, power;
1461
1462                         if (gadget_is_dualspeed(gadget)
1463                                         && gadget->speed == USB_SPEED_HIGH) {
1464                                 config = dev->hs_config->bConfigurationValue;
1465                                 power = dev->hs_config->bMaxPower;
1466                         } else {
1467                                 config = dev->config->bConfigurationValue;
1468                                 power = dev->config->bMaxPower;
1469                         }
1470
1471                         if (config == (u8) w_value) {
1472                                 value = 0;
1473                                 dev->current_config = config;
1474                                 usb_gadget_vbus_draw(gadget, 2 * power);
1475                         }
1476                 }
1477
1478                 /* report SET_CONFIGURATION like any other control request,
1479                  * except that usermode may not stall this.  the next
1480                  * request mustn't be allowed start until this finishes:
1481                  * endpoints and threads set up, etc.
1482                  *
1483                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1484                  * has bad/racey automagic that prevents synchronizing here.
1485                  * even kernel mode drivers often miss them.
1486                  */
1487                 if (value == 0) {
1488                         INFO (dev, "configuration #%d\n", dev->current_config);
1489                         if (dev->usermode_setup) {
1490                                 dev->setup_can_stall = 0;
1491                                 goto delegate;
1492                         }
1493                 }
1494                 break;
1495
1496 #ifndef CONFIG_USB_GADGET_PXA25X
1497         /* PXA automagically handles this request too */
1498         case USB_REQ_GET_CONFIGURATION:
1499                 if (ctrl->bRequestType != 0x80)
1500                         goto unrecognized;
1501                 *(u8 *)req->buf = dev->current_config;
1502                 value = min (w_length, (u16) 1);
1503                 break;
1504 #endif
1505
1506         default:
1507 unrecognized:
1508                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1509                         dev->usermode_setup ? "delegate" : "fail",
1510                         ctrl->bRequestType, ctrl->bRequest,
1511                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1512
1513                 /* if there's an ep0 reader, don't stall */
1514                 if (dev->usermode_setup) {
1515                         dev->setup_can_stall = 1;
1516 delegate:
1517                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1518                                                 ? 1 : 0;
1519                         dev->setup_wLength = w_length;
1520                         dev->setup_out_ready = 0;
1521                         dev->setup_out_error = 0;
1522                         value = 0;
1523
1524                         /* read DATA stage for OUT right away */
1525                         if (unlikely (!dev->setup_in && w_length)) {
1526                                 value = setup_req (gadget->ep0, dev->req,
1527                                                         w_length);
1528                                 if (value < 0)
1529                                         break;
1530                                 value = usb_ep_queue (gadget->ep0, dev->req,
1531                                                         GFP_ATOMIC);
1532                                 if (value < 0) {
1533                                         clean_req (gadget->ep0, dev->req);
1534                                         break;
1535                                 }
1536
1537                                 /* we can't currently stall these */
1538                                 dev->setup_can_stall = 0;
1539                         }
1540
1541                         /* state changes when reader collects event */
1542                         event = next_event (dev, GADGETFS_SETUP);
1543                         event->u.setup = *ctrl;
1544                         ep0_readable (dev);
1545                         spin_unlock (&dev->lock);
1546                         return 0;
1547                 }
1548         }
1549
1550         /* proceed with data transfer and status phases? */
1551         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1552                 req->length = value;
1553                 req->zero = value < w_length;
1554                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1555                 if (value < 0) {
1556                         DBG (dev, "ep_queue --> %d\n", value);
1557                         req->status = 0;
1558                 }
1559         }
1560
1561         /* device stalls when value < 0 */
1562         spin_unlock (&dev->lock);
1563         return value;
1564 }
1565
1566 static void destroy_ep_files (struct dev_data *dev)
1567 {
1568         DBG (dev, "%s %d\n", __func__, dev->state);
1569
1570         /* dev->state must prevent interference */
1571         spin_lock_irq (&dev->lock);
1572         while (!list_empty(&dev->epfiles)) {
1573                 struct ep_data  *ep;
1574                 struct inode    *parent;
1575                 struct dentry   *dentry;
1576
1577                 /* break link to FS */
1578                 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1579                 list_del_init (&ep->epfiles);
1580                 dentry = ep->dentry;
1581                 ep->dentry = NULL;
1582                 parent = dentry->d_parent->d_inode;
1583
1584                 /* break link to controller */
1585                 if (ep->state == STATE_EP_ENABLED)
1586                         (void) usb_ep_disable (ep->ep);
1587                 ep->state = STATE_EP_UNBOUND;
1588                 usb_ep_free_request (ep->ep, ep->req);
1589                 ep->ep = NULL;
1590                 wake_up (&ep->wait);
1591                 put_ep (ep);
1592
1593                 spin_unlock_irq (&dev->lock);
1594
1595                 /* break link to dcache */
1596                 mutex_lock (&parent->i_mutex);
1597                 d_delete (dentry);
1598                 dput (dentry);
1599                 mutex_unlock (&parent->i_mutex);
1600
1601                 spin_lock_irq (&dev->lock);
1602         }
1603         spin_unlock_irq (&dev->lock);
1604 }
1605
1606
1607 static struct inode *
1608 gadgetfs_create_file (struct super_block *sb, char const *name,
1609                 void *data, const struct file_operations *fops,
1610                 struct dentry **dentry_p);
1611
1612 static int activate_ep_files (struct dev_data *dev)
1613 {
1614         struct usb_ep   *ep;
1615         struct ep_data  *data;
1616
1617         gadget_for_each_ep (ep, dev->gadget) {
1618
1619                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1620                 if (!data)
1621                         goto enomem0;
1622                 data->state = STATE_EP_DISABLED;
1623                 mutex_init(&data->lock);
1624                 init_waitqueue_head (&data->wait);
1625
1626                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1627                 atomic_set (&data->count, 1);
1628                 data->dev = dev;
1629                 get_dev (dev);
1630
1631                 data->ep = ep;
1632                 ep->driver_data = data;
1633
1634                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1635                 if (!data->req)
1636                         goto enomem1;
1637
1638                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1639                                 data, &ep_config_operations,
1640                                 &data->dentry);
1641                 if (!data->inode)
1642                         goto enomem2;
1643                 list_add_tail (&data->epfiles, &dev->epfiles);
1644         }
1645         return 0;
1646
1647 enomem2:
1648         usb_ep_free_request (ep, data->req);
1649 enomem1:
1650         put_dev (dev);
1651         kfree (data);
1652 enomem0:
1653         DBG (dev, "%s enomem\n", __func__);
1654         destroy_ep_files (dev);
1655         return -ENOMEM;
1656 }
1657
1658 static void
1659 gadgetfs_unbind (struct usb_gadget *gadget)
1660 {
1661         struct dev_data         *dev = get_gadget_data (gadget);
1662
1663         DBG (dev, "%s\n", __func__);
1664
1665         spin_lock_irq (&dev->lock);
1666         dev->state = STATE_DEV_UNBOUND;
1667         spin_unlock_irq (&dev->lock);
1668
1669         destroy_ep_files (dev);
1670         gadget->ep0->driver_data = NULL;
1671         set_gadget_data (gadget, NULL);
1672
1673         /* we've already been disconnected ... no i/o is active */
1674         if (dev->req)
1675                 usb_ep_free_request (gadget->ep0, dev->req);
1676         DBG (dev, "%s done\n", __func__);
1677         put_dev (dev);
1678 }
1679
1680 static struct dev_data          *the_device;
1681
1682 static int
1683 gadgetfs_bind (struct usb_gadget *gadget)
1684 {
1685         struct dev_data         *dev = the_device;
1686
1687         if (!dev)
1688                 return -ESRCH;
1689         if (0 != strcmp (CHIP, gadget->name)) {
1690                 pr_err("%s expected %s controller not %s\n",
1691                         shortname, CHIP, gadget->name);
1692                 return -ENODEV;
1693         }
1694
1695         set_gadget_data (gadget, dev);
1696         dev->gadget = gadget;
1697         gadget->ep0->driver_data = dev;
1698
1699         /* preallocate control response and buffer */
1700         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1701         if (!dev->req)
1702                 goto enomem;
1703         dev->req->context = NULL;
1704         dev->req->complete = epio_complete;
1705
1706         if (activate_ep_files (dev) < 0)
1707                 goto enomem;
1708
1709         INFO (dev, "bound to %s driver\n", gadget->name);
1710         spin_lock_irq(&dev->lock);
1711         dev->state = STATE_DEV_UNCONNECTED;
1712         spin_unlock_irq(&dev->lock);
1713         get_dev (dev);
1714         return 0;
1715
1716 enomem:
1717         gadgetfs_unbind (gadget);
1718         return -ENOMEM;
1719 }
1720
1721 static void
1722 gadgetfs_disconnect (struct usb_gadget *gadget)
1723 {
1724         struct dev_data         *dev = get_gadget_data (gadget);
1725         unsigned long           flags;
1726
1727         spin_lock_irqsave (&dev->lock, flags);
1728         if (dev->state == STATE_DEV_UNCONNECTED)
1729                 goto exit;
1730         dev->state = STATE_DEV_UNCONNECTED;
1731
1732         INFO (dev, "disconnected\n");
1733         next_event (dev, GADGETFS_DISCONNECT);
1734         ep0_readable (dev);
1735 exit:
1736         spin_unlock_irqrestore (&dev->lock, flags);
1737 }
1738
1739 static void
1740 gadgetfs_suspend (struct usb_gadget *gadget)
1741 {
1742         struct dev_data         *dev = get_gadget_data (gadget);
1743
1744         INFO (dev, "suspended from state %d\n", dev->state);
1745         spin_lock (&dev->lock);
1746         switch (dev->state) {
1747         case STATE_DEV_SETUP:           // VERY odd... host died??
1748         case STATE_DEV_CONNECTED:
1749         case STATE_DEV_UNCONNECTED:
1750                 next_event (dev, GADGETFS_SUSPEND);
1751                 ep0_readable (dev);
1752                 /* FALLTHROUGH */
1753         default:
1754                 break;
1755         }
1756         spin_unlock (&dev->lock);
1757 }
1758
1759 static struct usb_gadget_driver gadgetfs_driver = {
1760         .function       = (char *) driver_desc,
1761         .unbind         = gadgetfs_unbind,
1762         .setup          = gadgetfs_setup,
1763         .disconnect     = gadgetfs_disconnect,
1764         .suspend        = gadgetfs_suspend,
1765
1766         .driver = {
1767                 .name           = (char *) shortname,
1768         },
1769 };
1770
1771 /*----------------------------------------------------------------------*/
1772
1773 static void gadgetfs_nop(struct usb_gadget *arg) { }
1774
1775 static int gadgetfs_probe (struct usb_gadget *gadget)
1776 {
1777         CHIP = gadget->name;
1778         return -EISNAM;
1779 }
1780
1781 static struct usb_gadget_driver probe_driver = {
1782         .max_speed      = USB_SPEED_HIGH,
1783         .unbind         = gadgetfs_nop,
1784         .setup          = (void *)gadgetfs_nop,
1785         .disconnect     = gadgetfs_nop,
1786         .driver = {
1787                 .name           = "nop",
1788         },
1789 };
1790
1791
1792 /* DEVICE INITIALIZATION
1793  *
1794  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1795  *     status = write (fd, descriptors, sizeof descriptors)
1796  *
1797  * That write establishes the device configuration, so the kernel can
1798  * bind to the controller ... guaranteeing it can handle enumeration
1799  * at all necessary speeds.  Descriptor order is:
1800  *
1801  * . message tag (u32, host order) ... for now, must be zero; it
1802  *      would change to support features like multi-config devices
1803  * . full/low speed config ... all wTotalLength bytes (with interface,
1804  *      class, altsetting, endpoint, and other descriptors)
1805  * . high speed config ... all descriptors, for high speed operation;
1806  *      this one's optional except for high-speed hardware
1807  * . device descriptor
1808  *
1809  * Endpoints are not yet enabled. Drivers must wait until device
1810  * configuration and interface altsetting changes create
1811  * the need to configure (or unconfigure) them.
1812  *
1813  * After initialization, the device stays active for as long as that
1814  * $CHIP file is open.  Events must then be read from that descriptor,
1815  * such as configuration notifications.
1816  */
1817
1818 static int is_valid_config (struct usb_config_descriptor *config)
1819 {
1820         return config->bDescriptorType == USB_DT_CONFIG
1821                 && config->bLength == USB_DT_CONFIG_SIZE
1822                 && config->bConfigurationValue != 0
1823                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1824                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1825         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1826         /* FIXME check lengths: walk to end */
1827 }
1828
1829 static ssize_t
1830 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1831 {
1832         struct dev_data         *dev = fd->private_data;
1833         ssize_t                 value = len, length = len;
1834         unsigned                total;
1835         u32                     tag;
1836         char                    *kbuf;
1837
1838         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1839                 return -EINVAL;
1840
1841         /* we might need to change message format someday */
1842         if (copy_from_user (&tag, buf, 4))
1843                 return -EFAULT;
1844         if (tag != 0)
1845                 return -EINVAL;
1846         buf += 4;
1847         length -= 4;
1848
1849         kbuf = memdup_user(buf, length);
1850         if (IS_ERR(kbuf))
1851                 return PTR_ERR(kbuf);
1852
1853         spin_lock_irq (&dev->lock);
1854         value = -EINVAL;
1855         if (dev->buf)
1856                 goto fail;
1857         dev->buf = kbuf;
1858
1859         /* full or low speed config */
1860         dev->config = (void *) kbuf;
1861         total = le16_to_cpu(dev->config->wTotalLength);
1862         if (!is_valid_config (dev->config) || total >= length)
1863                 goto fail;
1864         kbuf += total;
1865         length -= total;
1866
1867         /* optional high speed config */
1868         if (kbuf [1] == USB_DT_CONFIG) {
1869                 dev->hs_config = (void *) kbuf;
1870                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1871                 if (!is_valid_config (dev->hs_config) || total >= length)
1872                         goto fail;
1873                 kbuf += total;
1874                 length -= total;
1875         }
1876
1877         /* could support multiple configs, using another encoding! */
1878
1879         /* device descriptor (tweaked for paranoia) */
1880         if (length != USB_DT_DEVICE_SIZE)
1881                 goto fail;
1882         dev->dev = (void *)kbuf;
1883         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1884                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1885                         || dev->dev->bNumConfigurations != 1)
1886                 goto fail;
1887         dev->dev->bNumConfigurations = 1;
1888         dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1889
1890         /* triggers gadgetfs_bind(); then we can enumerate. */
1891         spin_unlock_irq (&dev->lock);
1892         if (dev->hs_config)
1893                 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1894         else
1895                 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1896         value = usb_gadget_probe_driver(&gadgetfs_driver, gadgetfs_bind);
1897         if (value != 0) {
1898                 kfree (dev->buf);
1899                 dev->buf = NULL;
1900         } else {
1901                 /* at this point "good" hardware has for the first time
1902                  * let the USB the host see us.  alternatively, if users
1903                  * unplug/replug that will clear all the error state.
1904                  *
1905                  * note:  everything running before here was guaranteed
1906                  * to choke driver model style diagnostics.  from here
1907                  * on, they can work ... except in cleanup paths that
1908                  * kick in after the ep0 descriptor is closed.
1909                  */
1910                 fd->f_op = &ep0_io_operations;
1911                 value = len;
1912         }
1913         return value;
1914
1915 fail:
1916         spin_unlock_irq (&dev->lock);
1917         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1918         kfree (dev->buf);
1919         dev->buf = NULL;
1920         return value;
1921 }
1922
1923 static int
1924 dev_open (struct inode *inode, struct file *fd)
1925 {
1926         struct dev_data         *dev = inode->i_private;
1927         int                     value = -EBUSY;
1928
1929         spin_lock_irq(&dev->lock);
1930         if (dev->state == STATE_DEV_DISABLED) {
1931                 dev->ev_next = 0;
1932                 dev->state = STATE_DEV_OPENED;
1933                 fd->private_data = dev;
1934                 get_dev (dev);
1935                 value = 0;
1936         }
1937         spin_unlock_irq(&dev->lock);
1938         return value;
1939 }
1940
1941 static const struct file_operations dev_init_operations = {
1942         .owner =        THIS_MODULE,
1943         .llseek =       no_llseek,
1944
1945         .open =         dev_open,
1946         .write =        dev_config,
1947         .fasync =       ep0_fasync,
1948         .unlocked_ioctl = dev_ioctl,
1949         .release =      dev_release,
1950 };
1951
1952 /*----------------------------------------------------------------------*/
1953
1954 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1955  *
1956  * Mounting the filesystem creates a controller file, used first for
1957  * device configuration then later for event monitoring.
1958  */
1959
1960
1961 /* FIXME PAM etc could set this security policy without mount options
1962  * if epfiles inherited ownership and permissons from ep0 ...
1963  */
1964
1965 static unsigned default_uid;
1966 static unsigned default_gid;
1967 static unsigned default_perm = S_IRUSR | S_IWUSR;
1968
1969 module_param (default_uid, uint, 0644);
1970 module_param (default_gid, uint, 0644);
1971 module_param (default_perm, uint, 0644);
1972
1973
1974 static struct inode *
1975 gadgetfs_make_inode (struct super_block *sb,
1976                 void *data, const struct file_operations *fops,
1977                 int mode)
1978 {
1979         struct inode *inode = new_inode (sb);
1980
1981         if (inode) {
1982                 inode->i_ino = get_next_ino();
1983                 inode->i_mode = mode;
1984                 inode->i_uid = default_uid;
1985                 inode->i_gid = default_gid;
1986                 inode->i_atime = inode->i_mtime = inode->i_ctime
1987                                 = CURRENT_TIME;
1988                 inode->i_private = data;
1989                 inode->i_fop = fops;
1990         }
1991         return inode;
1992 }
1993
1994 /* creates in fs root directory, so non-renamable and non-linkable.
1995  * so inode and dentry are paired, until device reconfig.
1996  */
1997 static struct inode *
1998 gadgetfs_create_file (struct super_block *sb, char const *name,
1999                 void *data, const struct file_operations *fops,
2000                 struct dentry **dentry_p)
2001 {
2002         struct dentry   *dentry;
2003         struct inode    *inode;
2004
2005         dentry = d_alloc_name(sb->s_root, name);
2006         if (!dentry)
2007                 return NULL;
2008
2009         inode = gadgetfs_make_inode (sb, data, fops,
2010                         S_IFREG | (default_perm & S_IRWXUGO));
2011         if (!inode) {
2012                 dput(dentry);
2013                 return NULL;
2014         }
2015         d_add (dentry, inode);
2016         *dentry_p = dentry;
2017         return inode;
2018 }
2019
2020 static const struct super_operations gadget_fs_operations = {
2021         .statfs =       simple_statfs,
2022         .drop_inode =   generic_delete_inode,
2023 };
2024
2025 static int
2026 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2027 {
2028         struct inode    *inode;
2029         struct dev_data *dev;
2030
2031         if (the_device)
2032                 return -ESRCH;
2033
2034         /* fake probe to determine $CHIP */
2035         (void) usb_gadget_probe_driver(&probe_driver, gadgetfs_probe);
2036         if (!CHIP)
2037                 return -ENODEV;
2038
2039         /* superblock */
2040         sb->s_blocksize = PAGE_CACHE_SIZE;
2041         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2042         sb->s_magic = GADGETFS_MAGIC;
2043         sb->s_op = &gadget_fs_operations;
2044         sb->s_time_gran = 1;
2045
2046         /* root inode */
2047         inode = gadgetfs_make_inode (sb,
2048                         NULL, &simple_dir_operations,
2049                         S_IFDIR | S_IRUGO | S_IXUGO);
2050         if (!inode)
2051                 goto Enomem;
2052         inode->i_op = &simple_dir_inode_operations;
2053         if (!(sb->s_root = d_make_root (inode)))
2054                 goto Enomem;
2055
2056         /* the ep0 file is named after the controller we expect;
2057          * user mode code can use it for sanity checks, like we do.
2058          */
2059         dev = dev_new ();
2060         if (!dev)
2061                 goto Enomem;
2062
2063         dev->sb = sb;
2064         if (!gadgetfs_create_file (sb, CHIP,
2065                                 dev, &dev_init_operations,
2066                                 &dev->dentry)) {
2067                 put_dev(dev);
2068                 goto Enomem;
2069         }
2070
2071         /* other endpoint files are available after hardware setup,
2072          * from binding to a controller.
2073          */
2074         the_device = dev;
2075         return 0;
2076
2077 Enomem:
2078         return -ENOMEM;
2079 }
2080
2081 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2082 static struct dentry *
2083 gadgetfs_mount (struct file_system_type *t, int flags,
2084                 const char *path, void *opts)
2085 {
2086         return mount_single (t, flags, opts, gadgetfs_fill_super);
2087 }
2088
2089 static void
2090 gadgetfs_kill_sb (struct super_block *sb)
2091 {
2092         kill_litter_super (sb);
2093         if (the_device) {
2094                 put_dev (the_device);
2095                 the_device = NULL;
2096         }
2097 }
2098
2099 /*----------------------------------------------------------------------*/
2100
2101 static struct file_system_type gadgetfs_type = {
2102         .owner          = THIS_MODULE,
2103         .name           = shortname,
2104         .mount          = gadgetfs_mount,
2105         .kill_sb        = gadgetfs_kill_sb,
2106 };
2107
2108 /*----------------------------------------------------------------------*/
2109
2110 static int __init init (void)
2111 {
2112         int status;
2113
2114         status = register_filesystem (&gadgetfs_type);
2115         if (status == 0)
2116                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2117                         shortname, driver_desc);
2118         return status;
2119 }
2120 module_init (init);
2121
2122 static void __exit cleanup (void)
2123 {
2124         pr_debug ("unregister %s\n", shortname);
2125         unregister_filesystem (&gadgetfs_type);
2126 }
2127 module_exit (cleanup);
2128