Pileus Git - ~andy/linux/blob - 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/$CHIP is configured
  49  *   (by writing configuration and device descriptors).  Afterwards it
  50  *   may serve as a source of device events, used to handle all control
  51  *   requests other than basic enumeration.
  52  *
  53  * - Then, after a SET_CONFIGURATION control request, ep_config() is
  54  *   called when each /dev/gadget/ep* file is configured (by writing
  55  *   endpoint descriptors).  Afterwards these files are used to write()
  56  *   IN data or to read() OUT data.  To halt the endpoint, a "wrong
  57  *   direction" request is issued (like reading an IN endpoint).
  58  *
  59  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
  60  * not possible on all hardware.  For example, precise fault handling with
  61  * respect to data left in endpoint fifos after aborted operations; or
  62  * selective clearing of endpoint halts, to implement SET_INTERFACE.
  63  */
  64
  65 #define DRIVER_DESC     "USB Gadget filesystem"
  66 #define DRIVER_VERSION  "24 Aug 2004"
  67
  68 static const char driver_desc [] = DRIVER_DESC;
  69 static const char shortname [] = "gadgetfs";
  70
  71 MODULE_DESCRIPTION (DRIVER_DESC);
  72 MODULE_AUTHOR ("David Brownell");
  73 MODULE_LICENSE ("GPL");
  74
  75
  76 /*----------------------------------------------------------------------*/
  77
  78 #define GADGETFS_MAGIC          0xaee71ee7
  79
  80 /* /dev/gadget/$CHIP represents ep0 and the whole device */
  81 enum ep0_state {
  82         /* DISBLED is the initial state.
  83          */
  84         STATE_DEV_DISABLED = 0,
  85
  86         /* Only one open() of /dev/gadget/$CHIP; only one file tracks
  87          * ep0/device i/o modes and binding to the controller.  Driver
  88          * must always write descriptors to initialize the device, then
  89          * the device becomes UNCONNECTED until enumeration.
  90          */
  91         STATE_DEV_OPENED,
  92
  93         /* From then on, ep0 fd is in either of two basic modes:
  94          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
  95          * - SETUP: read/write will transfer control data and succeed;
  96          *   or if "wrong direction", performs protocol stall
  97          */
  98         STATE_DEV_UNCONNECTED,
  99         STATE_DEV_CONNECTED,
 100         STATE_DEV_SETUP,
 101
 102         /* UNBOUND means the driver closed ep0, so the device won't be
 103          * accessible again (DEV_DISABLED) until all fds are closed.
 104          */
 105         STATE_DEV_UNBOUND,
 106 };
 107
 108 /* enough for the whole queue: most events invalidate others */
 109 #define N_EVENT                 5
 110
 111 struct dev_data {
 112         spinlock_t                      lock;
 113         atomic_t                        count;
 114         enum ep0_state                  state;          /* P: lock */
 115         struct usb_gadgetfs_event       event [N_EVENT];
 116         unsigned                        ev_next;
 117         struct fasync_struct            *fasync;
 118         u8                              current_config;
 119
 120         /* drivers reading ep0 MUST handle control requests (SETUP)
 121          * reported that way; else the host will time out.
 122          */
 123         unsigned                        usermode_setup : 1,
 124                                         setup_in : 1,
 125                                         setup_can_stall : 1,
 126                                         setup_out_ready : 1,
 127                                         setup_out_error : 1,
 128                                         setup_abort : 1;
 129         unsigned                        setup_wLength;
 130
 131         /* the rest is basically write-once */
 132         struct usb_config_descriptor    *config, *hs_config;
 133         struct usb_device_descriptor    *dev;
 134         struct usb_request              *req;
 135         struct usb_gadget               *gadget;
 136         struct list_head                epfiles;
 137         void                            *buf;
 138         wait_queue_head_t               wait;
 139         struct super_block              *sb;
 140         struct dentry                   *dentry;
 141
 142         /* except this scratch i/o buffer for ep0 */
 143         u8                              rbuf [256];
 144 };
 145
 146 static inline void get_dev (struct dev_data *data)
 147 {
 148         atomic_inc (&data->count);
 149 }
 150
 151 static void put_dev (struct dev_data *data)
 152 {
 153         if (likely (!atomic_dec_and_test (&data->count)))
 154                 return;
 155         /* needs no more cleanup */
 156         BUG_ON (waitqueue_active (&data->wait));
 157         kfree (data);
 158 }
 159
 160 static struct dev_data *dev_new (void)
 161 {
 162         struct dev_data         *dev;
 163
 164         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 165         if (!dev)
 166                 return NULL;
 167         dev->state = STATE_DEV_DISABLED;
 168         atomic_set (&dev->count, 1);
 169         spin_lock_init (&dev->lock);
 170         INIT_LIST_HEAD (&dev->epfiles);
 171         init_waitqueue_head (&dev->wait);
 172         return dev;
 173 }
 174
 175 /*----------------------------------------------------------------------*/
 176
 177 /* other /dev/gadget/$ENDPOINT files represent endpoints */
 178 enum ep_state {
 179         STATE_EP_DISABLED = 0,
 180         STATE_EP_READY,
 181         STATE_EP_ENABLED,
 182         STATE_EP_UNBOUND,
 183 };
 184
 185 struct ep_data {
 186         struct mutex                    lock;
 187         enum ep_state                   state;
 188         atomic_t                        count;
 189         struct dev_data                 *dev;
 190         /* must hold dev->lock before accessing ep or req */
 191         struct usb_ep                   *ep;
 192         struct usb_request              *req;
 193         ssize_t                         status;
 194         char                            name [16];
 195         struct usb_endpoint_descriptor  desc, hs_desc;
 196         struct list_head                epfiles;
 197         wait_queue_head_t               wait;
 198         struct dentry                   *dentry;
 199         struct inode                    *inode;
 200 };
 201
 202 static inline void get_ep (struct ep_data *data)
 203 {
 204         atomic_inc (&data->count);
 205 }
 206
 207 static void put_ep (struct ep_data *data)
 208 {
 209         if (likely (!atomic_dec_and_test (&data->count)))
 210                 return;
 211         put_dev (data->dev);
 212         /* needs no more cleanup */
 213         BUG_ON (!list_empty (&data->epfiles));
 214         BUG_ON (waitqueue_active (&data->wait));
 215         kfree (data);
 216 }
 217
 218 /*----------------------------------------------------------------------*/
 219
 220 /* most "how to use the hardware" policy choices are in userspace:
 221  * mapping endpoint roles (which the driver needs) to the capabilities
 222  * which the usb controller has.  most of those capabilities are exposed
 223  * implicitly, starting with the driver name and then endpoint names.
 224  */
 225
 226 static const char *CHIP;
 227
 228 /*----------------------------------------------------------------------*/
 229
 230 /* NOTE:  don't use dev_printk calls before binding to the gadget
 231  * at the end of ep0 configuration, or after unbind.
 232  */
 233
 234 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
 235 #define xprintk(d,level,fmt,args...) \
 236         printk(level "%s: " fmt , shortname , ## args)
 237
 238 #ifdef DEBUG
 239 #define DBG(dev,fmt,args...) \
 240         xprintk(dev , KERN_DEBUG , fmt , ## args)
 241 #else
 242 #define DBG(dev,fmt,args...) \
 243         do { } while (0)
 244 #endif /* DEBUG */
 245
 246 #ifdef VERBOSE_DEBUG
 247 #define VDEBUG  DBG
 248 #else
 249 #define VDEBUG(dev,fmt,args...) \
 250         do { } while (0)
 251 #endif /* DEBUG */
 252
 253 #define ERROR(dev,fmt,args...) \
 254         xprintk(dev , KERN_ERR , fmt , ## args)
 255 #define INFO(dev,fmt,args...) \
 256         xprintk(dev , KERN_INFO , fmt , ## args)
 257
 258
 259 /*----------------------------------------------------------------------*/
 260
 261 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 262  *
 263  * After opening, configure non-control endpoints.  Then use normal
 264  * stream read() and write() requests; and maybe ioctl() to get more
 265  * precise FIFO status when recovering from cancellation.
 266  */
 267
 268 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 269 {
 270         struct ep_data  *epdata = ep->driver_data;
 271
 272         if (!req->context)
 273                 return;
 274         if (req->status)
 275                 epdata->status = req->status;
 276         else
 277                 epdata->status = req->actual;
 278         complete ((struct completion *)req->context);
 279 }
 280
 281 /* tasklock endpoint, returning when it's connected.
 282  * still need dev->lock to use epdata->ep.
 283  */
 284 static int
 285 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
 286 {
 287         int     val;
 288
 289         if (f_flags & O_NONBLOCK) {
 290                 if (!mutex_trylock(&epdata->lock))
 291                         goto nonblock;
 292                 if (epdata->state != STATE_EP_ENABLED) {
 293                         mutex_unlock(&epdata->lock);
 294 nonblock:
 295                         val = -EAGAIN;
 296                 } else
 297                         val = 0;
 298                 return val;
 299         }
 300
 301         val = mutex_lock_interruptible(&epdata->lock);
 302         if (val < 0)
 303                 return val;
 304
 305         switch (epdata->state) {
 306         case STATE_EP_ENABLED:
 307                 break;
 308         // case STATE_EP_DISABLED:              /* "can't happen" */
 309         // case STATE_EP_READY:                 /* "can't happen" */
 310         default:                                /* error! */
 311                 pr_debug ("%s: ep %p not available, state %d\n",
 312                                 shortname, epdata, epdata->state);
 313                 // FALLTHROUGH
 314         case STATE_EP_UNBOUND:                  /* clean disconnect */
 315                 val = -ENODEV;
 316                 mutex_unlock(&epdata->lock);
 317         }
 318         return val;
 319 }
 320
 321 static ssize_t
 322 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 323 {
 324         DECLARE_COMPLETION_ONSTACK (done);
 325         int value;
 326
 327         spin_lock_irq (&epdata->dev->lock);
 328         if (likely (epdata->ep != NULL)) {
 329                 struct usb_request      *req = epdata->req;
 330
 331                 req->context = &done;
 332                 req->complete = epio_complete;
 333                 req->buf = buf;
 334                 req->length = len;
 335                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 336         } else
 337                 value = -ENODEV;
 338         spin_unlock_irq (&epdata->dev->lock);
 339
 340         if (likely (value == 0)) {
 341                 value = wait_event_interruptible (done.wait, done.done);
 342                 if (value != 0) {
 343                         spin_lock_irq (&epdata->dev->lock);
 344                         if (likely (epdata->ep != NULL)) {
 345                                 DBG (epdata->dev, "%s i/o interrupted\n",
 346                                                 epdata->name);
 347                                 usb_ep_dequeue (epdata->ep, epdata->req);
 348                                 spin_unlock_irq (&epdata->dev->lock);
 349
 350                                 wait_event (done.wait, done.done);
 351                                 if (epdata->status == -ECONNRESET)
 352                                         epdata->status = -EINTR;
 353                         } else {
 354                                 spin_unlock_irq (&epdata->dev->lock);
 355
 356                                 DBG (epdata->dev, "endpoint gone\n");
 357                                 epdata->status = -ENODEV;
 358                         }
 359                 }
 360                 return epdata->status;
 361         }
 362         return value;
 363 }
 364
 365
 366 /* handle a synchronous OUT bulk/intr/iso transfer */
 367 static ssize_t
 368 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 369 {
 370         struct ep_data          *data = fd->private_data;
 371         void                    *kbuf;
 372         ssize_t                 value;
 373
 374         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 375                 return value;
 376
 377         /* halt any endpoint by doing a "wrong direction" i/o call */
 378         if (usb_endpoint_dir_in(&data->desc)) {
 379                 if (usb_endpoint_xfer_isoc(&data->desc)) {
 380                         mutex_unlock(&data->lock);
 381                         return -EINVAL;
 382                 }
 383                 DBG (data->dev, "%s halt\n", data->name);
 384                 spin_lock_irq (&data->dev->lock);
 385                 if (likely (data->ep != NULL))
 386                         usb_ep_set_halt (data->ep);
 387                 spin_unlock_irq (&data->dev->lock);
 388                 mutex_unlock(&data->lock);
 389                 return -EBADMSG;
 390         }
 391
 392         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
 393
 394         value = -ENOMEM;
 395         kbuf = kmalloc (len, GFP_KERNEL);
 396         if (unlikely (!kbuf))
 397                 goto free1;
 398
 399         value = ep_io (data, kbuf, len);
 400         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
 401                 data->name, len, (int) value);
 402         if (value >= 0 && copy_to_user (buf, kbuf, value))
 403                 value = -EFAULT;
 404
 405 free1:
 406         mutex_unlock(&data->lock);
 407         kfree (kbuf);
 408         return value;
 409 }
 410
 411 /* handle a synchronous IN bulk/intr/iso transfer */
 412 static ssize_t
 413 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 414 {
 415         struct ep_data          *data = fd->private_data;
 416         void                    *kbuf;
 417         ssize_t                 value;
 418
 419         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 420                 return value;
 421
 422         /* halt any endpoint by doing a "wrong direction" i/o call */
 423         if (!usb_endpoint_dir_in(&data->desc)) {
 424                 if (usb_endpoint_xfer_isoc(&data->desc)) {
 425                         mutex_unlock(&data->lock);
 426                         return -EINVAL;
 427                 }
 428                 DBG (data->dev, "%s halt\n", data->name);
 429                 spin_lock_irq (&data->dev->lock);
 430                 if (likely (data->ep != NULL))
 431                         usb_ep_set_halt (data->ep);
 432                 spin_unlock_irq (&data->dev->lock);
 433                 mutex_unlock(&data->lock);
 434                 return -EBADMSG;
 435         }
 436
 437         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
 438
 439         value = -ENOMEM;
 440         kbuf = kmalloc (len, GFP_KERNEL);
 441         if (!kbuf)
 442                 goto free1;
 443         if (copy_from_user (kbuf, buf, len)) {
 444                 value = -EFAULT;
 445                 goto free1;
 446         }
 447
 448         value = ep_io (data, kbuf, len);
 449         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
 450                 data->name, len, (int) value);
 451 free1:
 452         mutex_unlock(&data->lock);
 453         kfree (kbuf);
 454         return value;
 455 }
 456
 457 static int
 458 ep_release (struct inode *inode, struct file *fd)
 459 {
 460         struct ep_data          *data = fd->private_data;
 461         int value;
 462
 463         value = mutex_lock_interruptible(&data->lock);
 464         if (value < 0)
 465                 return value;
 466
 467         /* clean up if this can be reopened */
 468         if (data->state != STATE_EP_UNBOUND) {
 469                 data->state = STATE_EP_DISABLED;
 470                 data->desc.bDescriptorType = 0;
 471                 data->hs_desc.bDescriptorType = 0;
 472                 usb_ep_disable(data->ep);
 473         }
 474         mutex_unlock(&data->lock);
 475         put_ep (data);
 476         return 0;
 477 }
 478
 479 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
 480 {
 481         struct ep_data          *data = fd->private_data;
 482         int                     status;
 483
 484         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 485                 return status;
 486
 487         spin_lock_irq (&data->dev->lock);
 488         if (likely (data->ep != NULL)) {
 489                 switch (code) {
 490                 case GADGETFS_FIFO_STATUS:
 491                         status = usb_ep_fifo_status (data->ep);
 492                         break;
 493                 case GADGETFS_FIFO_FLUSH:
 494                         usb_ep_fifo_flush (data->ep);
 495                         break;
 496                 case GADGETFS_CLEAR_HALT:
 497                         status = usb_ep_clear_halt (data->ep);
 498                         break;
 499                 default:
 500                         status = -ENOTTY;
 501                 }
 502         } else
 503                 status = -ENODEV;
 504         spin_unlock_irq (&data->dev->lock);
 505         mutex_unlock(&data->lock);
 506         return status;
 507 }
 508
 509 /*----------------------------------------------------------------------*/
 510
 511 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 512
 513 struct kiocb_priv {
 514         struct usb_request      *req;
 515         struct ep_data          *epdata;
 516         void                    *buf;
 517         const struct iovec      *iv;
 518         unsigned long           nr_segs;
 519         unsigned                actual;
 520 };
 521
 522 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
 523 {
 524         struct kiocb_priv       *priv = iocb->private;
 525         struct ep_data          *epdata;
 526         int                     value;
 527
 528         local_irq_disable();
 529         epdata = priv->epdata;
 530         // spin_lock(&epdata->dev->lock);
 531         kiocbSetCancelled(iocb);
 532         if (likely(epdata && epdata->ep && priv->req))
 533                 value = usb_ep_dequeue (epdata->ep, priv->req);
 534         else
 535                 value = -EINVAL;
 536         // spin_unlock(&epdata->dev->lock);
 537         local_irq_enable();
 538
 539         aio_put_req(iocb);
 540         return value;
 541 }
 542
 543 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
 544 {
 545         struct kiocb_priv       *priv = iocb->private;
 546         ssize_t                 len, total;
 547         void                    *to_copy;
 548         int                     i;
 549
 550         /* we "retry" to get the right mm context for this: */
 551
 552         /* copy stuff into user buffers */
 553         total = priv->actual;
 554         len = 0;
 555         to_copy = priv->buf;
 556         for (i=0; i < priv->nr_segs; i++) {
 557                 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
 558
 559                 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
 560                         if (len == 0)
 561                                 len = -EFAULT;
 562                         break;
 563                 }
 564
 565                 total -= this;
 566                 len += this;
 567                 to_copy += this;
 568                 if (total == 0)
 569                         break;
 570         }
 571         kfree(priv->buf);
 572         kfree(priv);
 573         return len;
 574 }
 575
 576 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 577 {
 578         struct kiocb            *iocb = req->context;
 579         struct kiocb_priv       *priv = iocb->private;
 580         struct ep_data          *epdata = priv->epdata;
 581
 582         /* lock against disconnect (and ideally, cancel) */
 583         spin_lock(&epdata->dev->lock);
 584         priv->req = NULL;
 585         priv->epdata = NULL;
 586
 587         /* if this was a write or a read returning no data then we
 588          * don't need to copy anything to userspace, so we can
 589          * complete the aio request immediately.
 590          */
 591         if (priv->iv == NULL || unlikely(req->actual == 0)) {
 592                 kfree(req->buf);
 593                 kfree(priv);
 594                 iocb->private = NULL;
 595                 /* aio_complete() reports bytes-transferred _and_ faults */
 596                 aio_complete(iocb, req->actual ? req->actual : req->status,
 597                                 req->status);
 598         } else {
 599                 /* retry() won't report both; so we hide some faults */
 600                 if (unlikely(0 != req->status))
 601                         DBG(epdata->dev, "%s fault %d len %d\n",
 602                                 ep->name, req->status, req->actual);
 603
 604                 priv->buf = req->buf;
 605                 priv->actual = req->actual;
 606                 kick_iocb(iocb);
 607         }
 608         spin_unlock(&epdata->dev->lock);
 609
 610         usb_ep_free_request(ep, req);
 611         put_ep(epdata);
 612 }
 613
 614 static ssize_t
 615 ep_aio_rwtail(
 616         struct kiocb    *iocb,
 617         char            *buf,
 618         size_t          len,
 619         struct ep_data  *epdata,
 620         const struct iovec *iv,
 621         unsigned long   nr_segs
 622 )
 623 {
 624         struct kiocb_priv       *priv;
 625         struct usb_request      *req;
 626         ssize_t                 value;
 627
 628         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 629         if (!priv) {
 630                 value = -ENOMEM;
 631 fail:
 632                 kfree(buf);
 633                 return value;
 634         }
 635         iocb->private = priv;
 636         priv->iv = iv;
 637         priv->nr_segs = nr_segs;
 638
 639         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 640         if (unlikely(value < 0)) {
 641                 kfree(priv);
 642                 goto fail;
 643         }
 644
 645         iocb->ki_cancel = ep_aio_cancel;
 646         get_ep(epdata);
 647         priv->epdata = epdata;
 648         priv->actual = 0;
 649
 650         /* each kiocb is coupled to one usb_request, but we can't
 651          * allocate or submit those if the host disconnected.
 652          */
 653         spin_lock_irq(&epdata->dev->lock);
 654         if (likely(epdata->ep)) {
 655                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 656                 if (likely(req)) {
 657                         priv->req = req;
 658                         req->buf = buf;
 659                         req->length = len;
 660                         req->complete = ep_aio_complete;
 661                         req->context = iocb;
 662                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 663                         if (unlikely(0 != value))
 664                                 usb_ep_free_request(epdata->ep, req);
 665                 } else
 666                         value = -EAGAIN;
 667         } else
 668                 value = -ENODEV;
 669         spin_unlock_irq(&epdata->dev->lock);
 670
 671         mutex_unlock(&epdata->lock);
 672
 673         if (unlikely(value)) {
 674                 kfree(priv);
 675                 put_ep(epdata);
 676         } else
 677                 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
 678         return value;
 679 }
 680
 681 static ssize_t
 682 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
 683                 unsigned long nr_segs, loff_t o)
 684 {
 685         struct ep_data          *epdata = iocb->ki_filp->private_data;
 686         char                    *buf;
 687
 688         if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
 689                 return -EINVAL;
 690
 691         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 692         if (unlikely(!buf))
 693                 return -ENOMEM;
 694
 695         iocb->ki_retry = ep_aio_read_retry;
 696         return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
 697 }
 698
 699 static ssize_t
 700 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
 701                 unsigned long nr_segs, loff_t o)
 702 {
 703         struct ep_data          *epdata = iocb->ki_filp->private_data;
 704         char                    *buf;
 705         size_t                  len = 0;
 706         int                     i = 0;
 707
 708         if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
 709                 return -EINVAL;
 710
 711         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 712         if (unlikely(!buf))
 713                 return -ENOMEM;
 714
 715         for (i=0; i < nr_segs; i++) {
 716                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
 717                                 iov[i].iov_len) != 0)) {
 718                         kfree(buf);
 719                         return -EFAULT;
 720                 }
 721                 len += iov[i].iov_len;
 722         }
 723         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
 724 }
 725
 726 /*----------------------------------------------------------------------*/
 727
 728 /* used after endpoint configuration */
 729 static const struct file_operations ep_io_operations = {
 730         .owner =        THIS_MODULE,
 731         .llseek =       no_llseek,
 732
 733         .read =         ep_read,
 734         .write =        ep_write,
 735         .unlocked_ioctl = ep_ioctl,
 736         .release =      ep_release,
 737
 738         .aio_read =     ep_aio_read,
 739         .aio_write =    ep_aio_write,
 740 };
 741
 742 /* ENDPOINT INITIALIZATION
 743  *
 744  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 745  *     status = write (fd, descriptors, sizeof descriptors)
 746  *
 747  * That write establishes the endpoint configuration, configuring
 748  * the controller to process bulk, interrupt, or isochronous transfers
 749  * at the right maxpacket size, and so on.
 750  *
 751  * The descriptors are message type 1, identified by a host order u32
 752  * at the beginning of what's written.  Descriptor order is: full/low
 753  * speed descriptor, then optional high speed descriptor.
 754  */
 755 static ssize_t
 756 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 757 {
 758         struct ep_data          *data = fd->private_data;
 759         struct usb_ep           *ep;
 760         u32                     tag;
 761         int                     value, length = len;
 762
 763         value = mutex_lock_interruptible(&data->lock);
 764         if (value < 0)
 765                 return value;
 766
 767         if (data->state != STATE_EP_READY) {
 768                 value = -EL2HLT;
 769                 goto fail;
 770         }
 771
 772         value = len;
 773         if (len < USB_DT_ENDPOINT_SIZE + 4)
 774                 goto fail0;
 775
 776         /* we might need to change message format someday */
 777         if (copy_from_user (&tag, buf, 4)) {
 778                 goto fail1;
 779         }
 780         if (tag != 1) {
 781                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 782                 goto fail0;
 783         }
 784         buf += 4;
 785         len -= 4;
 786
 787         /* NOTE:  audio endpoint extensions not accepted here;
 788          * just don't include the extra bytes.
 789          */
 790
 791         /* full/low speed descriptor, then high speed */
 792         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 793                 goto fail1;
 794         }
 795         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 796                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 797                 goto fail0;
 798         if (len != USB_DT_ENDPOINT_SIZE) {
 799                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 800                         goto fail0;
 801                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 802                                         USB_DT_ENDPOINT_SIZE)) {
 803                         goto fail1;
 804                 }
 805                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 806                                 || data->hs_desc.bDescriptorType
 807                                         != USB_DT_ENDPOINT) {
 808                         DBG(data->dev, "config %s, bad hs length or type\n",
 809                                         data->name);
 810                         goto fail0;
 811                 }
 812         }
 813
 814         spin_lock_irq (&data->dev->lock);
 815         if (data->dev->state == STATE_DEV_UNBOUND) {
 816                 value = -ENOENT;
 817                 goto gone;
 818         } else if ((ep = data->ep) == NULL) {
 819                 value = -ENODEV;
 820                 goto gone;
 821         }
 822         switch (data->dev->gadget->speed) {
 823         case USB_SPEED_LOW:
 824         case USB_SPEED_FULL:
 825                 ep->desc = &data->desc;
 826                 value = usb_ep_enable(ep);
 827                 if (value == 0)
 828                         data->state = STATE_EP_ENABLED;
 829                 break;
 830         case USB_SPEED_HIGH:
 831                 /* fails if caller didn't provide that descriptor... */
 832                 ep->desc = &data->hs_desc;
 833                 value = usb_ep_enable(ep);
 834                 if (value == 0)
 835                         data->state = STATE_EP_ENABLED;
 836                 break;
 837         default:
 838                 DBG(data->dev, "unconnected, %s init abandoned\n",
 839                                 data->name);
 840                 value = -EINVAL;
 841         }
 842         if (value == 0) {
 843                 fd->f_op = &ep_io_operations;
 844                 value = length;
 845         }
 846 gone:
 847         spin_unlock_irq (&data->dev->lock);
 848         if (value < 0) {
 849 fail:
 850                 data->desc.bDescriptorType = 0;
 851                 data->hs_desc.bDescriptorType = 0;
 852         }
 853         mutex_unlock(&data->lock);
 854         return value;
 855 fail0:
 856         value = -EINVAL;
 857         goto fail;
 858 fail1:
 859         value = -EFAULT;
 860         goto fail;
 861 }
 862
 863 static int
 864 ep_open (struct inode *inode, struct file *fd)
 865 {
 866         struct ep_data          *data = inode->i_private;
 867         int                     value = -EBUSY;
 868
 869         if (mutex_lock_interruptible(&data->lock) != 0)
 870                 return -EINTR;
 871         spin_lock_irq (&data->dev->lock);
 872         if (data->dev->state == STATE_DEV_UNBOUND)
 873                 value = -ENOENT;
 874         else if (data->state == STATE_EP_DISABLED) {
 875                 value = 0;
 876                 data->state = STATE_EP_READY;
 877                 get_ep (data);
 878                 fd->private_data = data;
 879                 VDEBUG (data->dev, "%s ready\n", data->name);
 880         } else
 881                 DBG (data->dev, "%s state %d\n",
 882                         data->name, data->state);
 883         spin_unlock_irq (&data->dev->lock);
 884         mutex_unlock(&data->lock);
 885         return value;
 886 }
 887
 888 /* used before endpoint configuration */
 889 static const struct file_operations ep_config_operations = {
 890         .owner =        THIS_MODULE,
 891         .llseek =       no_llseek,
 892
 893         .open =         ep_open,
 894         .write =        ep_config,
 895         .release =      ep_release,
 896 };
 897
 898 /*----------------------------------------------------------------------*/
 899
 900 /* EP0 IMPLEMENTATION can be partly in userspace.
 901  *
 902  * Drivers that use this facility receive various events, including
 903  * control requests the kernel doesn't handle.  Drivers that don't
 904  * use this facility may be too simple-minded for real applications.
 905  */
 906
 907 static inline void ep0_readable (struct dev_data *dev)
 908 {
 909         wake_up (&dev->wait);
 910         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 911 }
 912
 913 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 914 {
 915         struct dev_data         *dev = ep->driver_data;
 916
 917         if (req->buf != dev->rbuf) {
 918                 kfree(req->buf);
 919                 req->buf = dev->rbuf;
 920         }
 921         req->complete = epio_complete;
 922         dev->setup_out_ready = 0;
 923 }
 924
 925 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 926 {
 927         struct dev_data         *dev = ep->driver_data;
 928         unsigned long           flags;
 929         int                     free = 1;
 930
 931         /* for control OUT, data must still get to userspace */
 932         spin_lock_irqsave(&dev->lock, flags);
 933         if (!dev->setup_in) {
 934                 dev->setup_out_error = (req->status != 0);
 935                 if (!dev->setup_out_error)
 936                         free = 0;
 937                 dev->setup_out_ready = 1;
 938                 ep0_readable (dev);
 939         }
 940
 941         /* clean up as appropriate */
 942         if (free && req->buf != &dev->rbuf)
 943                 clean_req (ep, req);
 944         req->complete = epio_complete;
 945         spin_unlock_irqrestore(&dev->lock, flags);
 946 }
 947
 948 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 949 {
 950         struct dev_data *dev = ep->driver_data;
 951
 952         if (dev->setup_out_ready) {
 953                 DBG (dev, "ep0 request busy!\n");
 954                 return -EBUSY;
 955         }
 956         if (len > sizeof (dev->rbuf))
 957                 req->buf = kmalloc(len, GFP_ATOMIC);
 958         if (req->buf == NULL) {
 959                 req->buf = dev->rbuf;
 960                 return -ENOMEM;
 961         }
 962         req->complete = ep0_complete;
 963         req->length = len;
 964         req->zero = 0;
 965         return 0;
 966 }
 967
 968 static ssize_t
 969 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 970 {
 971         struct dev_data                 *dev = fd->private_data;
 972         ssize_t                         retval;
 973         enum ep0_state                  state;
 974
 975         spin_lock_irq (&dev->lock);
 976
 977         /* report fd mode change before acting on it */
 978         if (dev->setup_abort) {
 979                 dev->setup_abort = 0;
 980                 retval = -EIDRM;
 981                 goto done;
 982         }
 983
 984         /* control DATA stage */
 985         if ((state = dev->state) == STATE_DEV_SETUP) {
 986
 987                 if (dev->setup_in) {            /* stall IN */
 988                         VDEBUG(dev, "ep0in stall\n");
 989                         (void) usb_ep_set_halt (dev->gadget->ep0);
 990                         retval = -EL2HLT;
 991                         dev->state = STATE_DEV_CONNECTED;
 992
 993                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
 994                         struct usb_ep           *ep = dev->gadget->ep0;
 995                         struct usb_request      *req = dev->req;
 996
 997                         if ((retval = setup_req (ep, req, 0)) == 0)
 998                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
 999                         dev->state = STATE_DEV_CONNECTED;
1000
1001                         /* assume that was SET_CONFIGURATION */
1002                         if (dev->current_config) {
1003                                 unsigned power;
1004
1005                                 if (gadget_is_dualspeed(dev->gadget)
1006                                                 && (dev->gadget->speed
1007                                                         == USB_SPEED_HIGH))
1008                                         power = dev->hs_config->bMaxPower;
1009                                 else
1010                                         power = dev->config->bMaxPower;
1011                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1012                         }
1013
1014                 } else {                        /* collect OUT data */
1015                         if ((fd->f_flags & O_NONBLOCK) != 0
1016                                         && !dev->setup_out_ready) {
1017                                 retval = -EAGAIN;
1018                                 goto done;
1019                         }
1020                         spin_unlock_irq (&dev->lock);
1021                         retval = wait_event_interruptible (dev->wait,
1022                                         dev->setup_out_ready != 0);
1023
1024                         /* FIXME state could change from under us */
1025                         spin_lock_irq (&dev->lock);
1026                         if (retval)
1027                                 goto done;
1028
1029                         if (dev->state != STATE_DEV_SETUP) {
1030                                 retval = -ECANCELED;
1031                                 goto done;
1032                         }
1033                         dev->state = STATE_DEV_CONNECTED;
1034
1035                         if (dev->setup_out_error)
1036                                 retval = -EIO;
1037                         else {
1038                                 len = min (len, (size_t)dev->req->actual);
1039 // FIXME don't call this with the spinlock held ...
1040                                 if (copy_to_user (buf, dev->req->buf, len))
1041                                         retval = -EFAULT;
1042                                 else
1043                                         retval = len;
1044                                 clean_req (dev->gadget->ep0, dev->req);
1045                                 /* NOTE userspace can't yet choose to stall */
1046                         }
1047                 }
1048                 goto done;
1049         }
1050
1051         /* else normal: return event data */
1052         if (len < sizeof dev->event [0]) {
1053                 retval = -EINVAL;
1054                 goto done;
1055         }
1056         len -= len % sizeof (struct usb_gadgetfs_event);
1057         dev->usermode_setup = 1;
1058
1059 scan:
1060         /* return queued events right away */
1061         if (dev->ev_next != 0) {
1062                 unsigned                i, n;
1063
1064                 n = len / sizeof (struct usb_gadgetfs_event);
1065                 if (dev->ev_next < n)
1066                         n = dev->ev_next;
1067
1068                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1069                 for (i = 0; i < n; i++) {
1070                         if (dev->event [i].type == GADGETFS_SETUP) {
1071                                 dev->state = STATE_DEV_SETUP;
1072                                 n = i + 1;
1073                                 break;
1074                         }
1075                 }
1076                 spin_unlock_irq (&dev->lock);
1077                 len = n * sizeof (struct usb_gadgetfs_event);
1078                 if (copy_to_user (buf, &dev->event, len))
1079                         retval = -EFAULT;
1080                 else
1081                         retval = len;
1082                 if (len > 0) {
1083                         /* NOTE this doesn't guard against broken drivers;
1084                          * concurrent ep0 readers may lose events.
1085                          */
1086                         spin_lock_irq (&dev->lock);
1087                         if (dev->ev_next > n) {
1088                                 memmove(&dev->event[0], &dev->event[n],
1089                                         sizeof (struct usb_gadgetfs_event)
1090                                                 * (dev->ev_next - n));
1091                         }
1092                         dev->ev_next -= n;
1093                         spin_unlock_irq (&dev->lock);
1094                 }
1095                 return retval;
1096         }
1097         if (fd->f_flags & O_NONBLOCK) {
1098                 retval = -EAGAIN;
1099                 goto done;
1100         }
1101
1102         switch (state) {
1103         default:
1104                 DBG (dev, "fail %s, state %d\n", __func__, state);
1105                 retval = -ESRCH;
1106                 break;
1107         case STATE_DEV_UNCONNECTED:
1108         case STATE_DEV_CONNECTED:
1109                 spin_unlock_irq (&dev->lock);
1110                 DBG (dev, "%s wait\n", __func__);
1111
1112                 /* wait for events */
1113                 retval = wait_event_interruptible (dev->wait,
1114                                 dev->ev_next != 0);
1115                 if (retval < 0)
1116                         return retval;
1117                 spin_lock_irq (&dev->lock);
1118                 goto scan;
1119         }
1120
1121 done:
1122         spin_unlock_irq (&dev->lock);
1123         return retval;
1124 }
1125
1126 static struct usb_gadgetfs_event *
1127 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1128 {
1129         struct usb_gadgetfs_event       *event;
1130         unsigned                        i;
1131
1132         switch (type) {
1133         /* these events purge the queue */
1134         case GADGETFS_DISCONNECT:
1135                 if (dev->state == STATE_DEV_SETUP)
1136                         dev->setup_abort = 1;
1137                 // FALL THROUGH
1138         case GADGETFS_CONNECT:
1139                 dev->ev_next = 0;
1140                 break;
1141         case GADGETFS_SETUP:            /* previous request timed out */
1142         case GADGETFS_SUSPEND:          /* same effect */
1143                 /* these events can't be repeated */
1144                 for (i = 0; i != dev->ev_next; i++) {
1145                         if (dev->event [i].type != type)
1146                                 continue;
1147                         DBG(dev, "discard old event[%d] %d\n", i, type);
1148                         dev->ev_next--;
1149                         if (i == dev->ev_next)
1150                                 break;
1151                         /* indices start at zero, for simplicity */
1152                         memmove (&dev->event [i], &dev->event [i + 1],
1153                                 sizeof (struct usb_gadgetfs_event)
1154                                         * (dev->ev_next - i));
1155                 }
1156                 break;
1157         default:
1158                 BUG ();
1159         }
1160         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1161         event = &dev->event [dev->ev_next++];
1162         BUG_ON (dev->ev_next > N_EVENT);
1163         memset (event, 0, sizeof *event);
1164         event->type = type;
1165         return event;
1166 }
1167
1168 static ssize_t
1169 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1170 {
1171         struct dev_data         *dev = fd->private_data;
1172         ssize_t                 retval = -ESRCH;
1173
1174         spin_lock_irq (&dev->lock);
1175
1176         /* report fd mode change before acting on it */
1177         if (dev->setup_abort) {
1178                 dev->setup_abort = 0;
1179                 retval = -EIDRM;
1180
1181         /* data and/or status stage for control request */
1182         } else if (dev->state == STATE_DEV_SETUP) {
1183
1184                 /* IN DATA+STATUS caller makes len <= wLength */
1185                 if (dev->setup_in) {
1186                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1187                         if (retval == 0) {
1188                                 dev->state = STATE_DEV_CONNECTED;
1189                                 spin_unlock_irq (&dev->lock);
1190                                 if (copy_from_user (dev->req->buf, buf, len))
1191                                         retval = -EFAULT;
1192                                 else {
1193                                         if (len < dev->setup_wLength)
1194                                                 dev->req->zero = 1;
1195                                         retval = usb_ep_queue (
1196                                                 dev->gadget->ep0, dev->req,
1197                                                 GFP_KERNEL);
1198                                 }
1199                                 if (retval < 0) {
1200                                         spin_lock_irq (&dev->lock);
1201                                         clean_req (dev->gadget->ep0, dev->req);
1202                                         spin_unlock_irq (&dev->lock);
1203                                 } else
1204                                         retval = len;
1205
1206                                 return retval;
1207                         }
1208
1209                 /* can stall some OUT transfers */
1210                 } else if (dev->setup_can_stall) {
1211                         VDEBUG(dev, "ep0out stall\n");
1212                         (void) usb_ep_set_halt (dev->gadget->ep0);
1213                         retval = -EL2HLT;
1214                         dev->state = STATE_DEV_CONNECTED;
1215                 } else {
1216                         DBG(dev, "bogus ep0out stall!\n");
1217                 }
1218         } else
1219                 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1220
1221         spin_unlock_irq (&dev->lock);
1222         return retval;
1223 }
1224
1225 static int
1226 ep0_fasync (int f, struct file *fd, int on)
1227 {
1228         struct dev_data         *dev = fd->private_data;
1229         // caller must F_SETOWN before signal delivery happens
1230         VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1231         return fasync_helper (f, fd, on, &dev->fasync);
1232 }
1233
1234 static struct usb_gadget_driver gadgetfs_driver;
1235
1236 static int
1237 dev_release (struct inode *inode, struct file *fd)
1238 {
1239         struct dev_data         *dev = fd->private_data;
1240
1241         /* closing ep0 === shutdown all */
1242
1243         usb_gadget_unregister_driver (&gadgetfs_driver);
1244
1245         /* at this point "good" hardware has disconnected the
1246          * device from USB; the host won't see it any more.
1247          * alternatively, all host requests will time out.
1248          */
1249
1250         kfree (dev->buf);
1251         dev->buf = NULL;
1252         put_dev (dev);
1253
1254         /* other endpoints were all decoupled from this device */
1255         spin_lock_irq(&dev->lock);
1256         dev->state = STATE_DEV_DISABLED;
1257         spin_unlock_irq(&dev->lock);
1258         return 0;
1259 }
1260
1261 static unsigned int
1262 ep0_poll (struct file *fd, poll_table *wait)
1263 {
1264        struct dev_data         *dev = fd->private_data;
1265        int                     mask = 0;
1266
1267        poll_wait(fd, &dev->wait, wait);
1268
1269        spin_lock_irq (&dev->lock);
1270
1271        /* report fd mode change before acting on it */
1272        if (dev->setup_abort) {
1273                dev->setup_abort = 0;
1274                mask = POLLHUP;
1275                goto out;
1276        }
1277
1278        if (dev->state == STATE_DEV_SETUP) {
1279                if (dev->setup_in || dev->setup_can_stall)
1280                        mask = POLLOUT;
1281        } else {
1282                if (dev->ev_next != 0)
1283                        mask = POLLIN;
1284        }
1285 out:
1286        spin_unlock_irq(&dev->lock);
1287        return mask;
1288 }
1289
1290 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1291 {
1292         struct dev_data         *dev = fd->private_data;
1293         struct usb_gadget       *gadget = dev->gadget;
1294         long ret = -ENOTTY;
1295
1296         if (gadget->ops->ioctl)
1297                 ret = gadget->ops->ioctl (gadget, code, value);
1298
1299         return ret;
1300 }
1301
1302 /* used after device configuration */
1303 static const struct file_operations ep0_io_operations = {
1304         .owner =        THIS_MODULE,
1305         .llseek =       no_llseek,
1306
1307         .read =         ep0_read,
1308         .write =        ep0_write,
1309         .fasync =       ep0_fasync,
1310         .poll =         ep0_poll,
1311         .unlocked_ioctl =       dev_ioctl,
1312         .release =      dev_release,
1313 };
1314
1315 /*----------------------------------------------------------------------*/
1316
1317 /* The in-kernel gadget driver handles most ep0 issues, in particular
1318  * enumerating the single configuration (as provided from user space).
1319  *
1320  * Unrecognized ep0 requests may be handled in user space.
1321  */
1322
1323 static void make_qualifier (struct dev_data *dev)
1324 {
1325         struct usb_qualifier_descriptor         qual;
1326         struct usb_device_descriptor            *desc;
1327
1328         qual.bLength = sizeof qual;
1329         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1330         qual.bcdUSB = cpu_to_le16 (0x0200);
1331
1332         desc = dev->dev;
1333         qual.bDeviceClass = desc->bDeviceClass;
1334         qual.bDeviceSubClass = desc->bDeviceSubClass;
1335         qual.bDeviceProtocol = desc->bDeviceProtocol;
1336
1337         /* assumes ep0 uses the same value for both speeds ... */
1338         qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1339
1340         qual.bNumConfigurations = 1;
1341         qual.bRESERVED = 0;
1342
1343         memcpy (dev->rbuf, &qual, sizeof qual);
1344 }
1345
1346 static int
1347 config_buf (struct dev_data *dev, u8 type, unsigned index)
1348 {
1349         int             len;
1350         int             hs = 0;
1351
1352         /* only one configuration */
1353         if (index > 0)
1354                 return -EINVAL;
1355
1356         if (gadget_is_dualspeed(dev->gadget)) {
1357                 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1358                 if (type == USB_DT_OTHER_SPEED_CONFIG)
1359                         hs = !hs;
1360         }
1361         if (hs) {
1362                 dev->req->buf = dev->hs_config;
1363                 len = le16_to_cpu(dev->hs_config->wTotalLength);
1364         } else {
1365                 dev->req->buf = dev->config;
1366                 len = le16_to_cpu(dev->config->wTotalLength);
1367         }
1368         ((u8 *)dev->req->buf) [1] = type;
1369         return len;
1370 }
1371
1372 static int
1373 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1374 {
1375         struct dev_data                 *dev = get_gadget_data (gadget);
1376         struct usb_request              *req = dev->req;
1377         int                             value = -EOPNOTSUPP;
1378         struct usb_gadgetfs_event       *event;
1379         u16                             w_value = le16_to_cpu(ctrl->wValue);
1380         u16                             w_length = le16_to_cpu(ctrl->wLength);
1381
1382         spin_lock (&dev->lock);
1383         dev->setup_abort = 0;
1384         if (dev->state == STATE_DEV_UNCONNECTED) {
1385                 if (gadget_is_dualspeed(gadget)
1386                                 && gadget->speed == USB_SPEED_HIGH
1387                                 && dev->hs_config == NULL) {
1388                         spin_unlock(&dev->lock);
1389                         ERROR (dev, "no high speed config??\n");
1390                         return -EINVAL;
1391                 }
1392
1393                 dev->state = STATE_DEV_CONNECTED;
1394
1395                 INFO (dev, "connected\n");
1396                 event = next_event (dev, GADGETFS_CONNECT);
1397                 event->u.speed = gadget->speed;
1398                 ep0_readable (dev);
1399
1400         /* host may have given up waiting for response.  we can miss control
1401          * requests handled lower down (device/endpoint status and features);
1402          * then ep0_{read,write} will report the wrong status. controller
1403          * driver will have aborted pending i/o.
1404          */
1405         } else if (dev->state == STATE_DEV_SETUP)
1406                 dev->setup_abort = 1;
1407
1408         req->buf = dev->rbuf;
1409         req->context = NULL;
1410         value = -EOPNOTSUPP;
1411         switch (ctrl->bRequest) {
1412
1413         case USB_REQ_GET_DESCRIPTOR:
1414                 if (ctrl->bRequestType != USB_DIR_IN)
1415                         goto unrecognized;
1416                 switch (w_value >> 8) {
1417
1418                 case USB_DT_DEVICE:
1419                         value = min (w_length, (u16) sizeof *dev->dev);
1420                         dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1421                         req->buf = dev->dev;
1422                         break;
1423                 case USB_DT_DEVICE_QUALIFIER:
1424                         if (!dev->hs_config)
1425                                 break;
1426                         value = min (w_length, (u16)
1427                                 sizeof (struct usb_qualifier_descriptor));
1428                         make_qualifier (dev);
1429                         break;
1430                 case USB_DT_OTHER_SPEED_CONFIG:
1431                         // FALLTHROUGH
1432                 case USB_DT_CONFIG:
1433                         value = config_buf (dev,
1434                                         w_value >> 8,
1435                                         w_value & 0xff);
1436                         if (value >= 0)
1437                                 value = min (w_length, (u16) value);
1438                         break;
1439                 case USB_DT_STRING:
1440                         goto unrecognized;
1441
1442                 default:                // all others are errors
1443                         break;
1444                 }
1445                 break;
1446
1447         /* currently one config, two speeds */
1448         case USB_REQ_SET_CONFIGURATION:
1449                 if (ctrl->bRequestType != 0)
1450                         goto unrecognized;
1451                 if (0 == (u8) w_value) {
1452                         value = 0;
1453                         dev->current_config = 0;
1454                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1455                         // user mode expected to disable endpoints
1456                 } else {
1457                         u8      config, power;
1458
1459                         if (gadget_is_dualspeed(gadget)
1460                                         && gadget->speed == USB_SPEED_HIGH) {
1461                                 config = dev->hs_config->bConfigurationValue;
1462                                 power = dev->hs_config->bMaxPower;
1463                         } else {
1464                                 config = dev->config->bConfigurationValue;
1465                                 power = dev->config->bMaxPower;
1466                         }
1467
1468                         if (config == (u8) w_value) {
1469                                 value = 0;
1470                                 dev->current_config = config;
1471                                 usb_gadget_vbus_draw(gadget, 2 * power);
1472                         }
1473                 }
1474
1475                 /* report SET_CONFIGURATION like any other control request,
1476                  * except that usermode may not stall this.  the next
1477                  * request mustn't be allowed start until this finishes:
1478                  * endpoints and threads set up, etc.
1479                  *
1480                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1481                  * has bad/racey automagic that prevents synchronizing here.
1482                  * even kernel mode drivers often miss them.
1483                  */
1484                 if (value == 0) {
1485                         INFO (dev, "configuration #%d\n", dev->current_config);
1486                         if (dev->usermode_setup) {
1487                                 dev->setup_can_stall = 0;
1488                                 goto delegate;
1489                         }
1490                 }
1491                 break;
1492
1493 #ifndef CONFIG_USB_GADGET_PXA25X
1494         /* PXA automagically handles this request too */
1495         case USB_REQ_GET_CONFIGURATION:
1496                 if (ctrl->bRequestType != 0x80)
1497                         goto unrecognized;
1498                 *(u8 *)req->buf = dev->current_config;
1499                 value = min (w_length, (u16) 1);
1500                 break;
1501 #endif
1502
1503         default:
1504 unrecognized:
1505                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1506                         dev->usermode_setup ? "delegate" : "fail",
1507                         ctrl->bRequestType, ctrl->bRequest,
1508                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1509
1510                 /* if there's an ep0 reader, don't stall */
1511                 if (dev->usermode_setup) {
1512                         dev->setup_can_stall = 1;
1513 delegate:
1514                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1515                                                 ? 1 : 0;
1516                         dev->setup_wLength = w_length;
1517                         dev->setup_out_ready = 0;
1518                         dev->setup_out_error = 0;
1519                         value = 0;
1520
1521                         /* read DATA stage for OUT right away */
1522                         if (unlikely (!dev->setup_in && w_length)) {
1523                                 value = setup_req (gadget->ep0, dev->req,
1524                                                         w_length);
1525                                 if (value < 0)
1526                                         break;
1527                                 value = usb_ep_queue (gadget->ep0, dev->req,
1528                                                         GFP_ATOMIC);
1529                                 if (value < 0) {
1530                                         clean_req (gadget->ep0, dev->req);
1531                                         break;
1532                                 }
1533
1534                                 /* we can't currently stall these */
1535                                 dev->setup_can_stall = 0;
1536                         }
1537
1538                         /* state changes when reader collects event */
1539                         event = next_event (dev, GADGETFS_SETUP);
1540                         event->u.setup = *ctrl;
1541                         ep0_readable (dev);
1542                         spin_unlock (&dev->lock);
1543                         return 0;
1544                 }
1545         }
1546
1547         /* proceed with data transfer and status phases? */
1548         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1549                 req->length = value;
1550                 req->zero = value < w_length;
1551                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1552                 if (value < 0) {
1553                         DBG (dev, "ep_queue --> %d\n", value);
1554                         req->status = 0;
1555                 }
1556         }
1557
1558         /* device stalls when value < 0 */
1559         spin_unlock (&dev->lock);
1560         return value;
1561 }
1562
1563 static void destroy_ep_files (struct dev_data *dev)
1564 {
1565         DBG (dev, "%s %d\n", __func__, dev->state);
1566
1567         /* dev->state must prevent interference */
1568         spin_lock_irq (&dev->lock);
1569         while (!list_empty(&dev->epfiles)) {
1570                 struct ep_data  *ep;
1571                 struct inode    *parent;
1572                 struct dentry   *dentry;
1573
1574                 /* break link to FS */
1575                 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1576                 list_del_init (&ep->epfiles);
1577                 dentry = ep->dentry;
1578                 ep->dentry = NULL;
1579                 parent = dentry->d_parent->d_inode;
1580
1581                 /* break link to controller */
1582                 if (ep->state == STATE_EP_ENABLED)
1583                         (void) usb_ep_disable (ep->ep);
1584                 ep->state = STATE_EP_UNBOUND;
1585                 usb_ep_free_request (ep->ep, ep->req);
1586                 ep->ep = NULL;
1587                 wake_up (&ep->wait);
1588                 put_ep (ep);
1589
1590                 spin_unlock_irq (&dev->lock);
1591
1592                 /* break link to dcache */
1593                 mutex_lock (&parent->i_mutex);
1594                 d_delete (dentry);
1595                 dput (dentry);
1596                 mutex_unlock (&parent->i_mutex);
1597
1598                 spin_lock_irq (&dev->lock);
1599         }
1600         spin_unlock_irq (&dev->lock);
1601 }
1602
1603
1604 static struct inode *
1605 gadgetfs_create_file (struct super_block *sb, char const *name,
1606                 void *data, const struct file_operations *fops,
1607                 struct dentry **dentry_p);
1608
1609 static int activate_ep_files (struct dev_data *dev)
1610 {
1611         struct usb_ep   *ep;
1612         struct ep_data  *data;
1613
1614         gadget_for_each_ep (ep, dev->gadget) {
1615
1616                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1617                 if (!data)
1618                         goto enomem0;
1619                 data->state = STATE_EP_DISABLED;
1620                 mutex_init(&data->lock);
1621                 init_waitqueue_head (&data->wait);
1622
1623                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1624                 atomic_set (&data->count, 1);
1625                 data->dev = dev;
1626                 get_dev (dev);
1627
1628                 data->ep = ep;
1629                 ep->driver_data = data;
1630
1631                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1632                 if (!data->req)
1633                         goto enomem1;
1634
1635                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1636                                 data, &ep_config_operations,
1637                                 &data->dentry);
1638                 if (!data->inode)
1639                         goto enomem2;
1640                 list_add_tail (&data->epfiles, &dev->epfiles);
1641         }
1642         return 0;
1643
1644 enomem2:
1645         usb_ep_free_request (ep, data->req);
1646 enomem1:
1647         put_dev (dev);
1648         kfree (data);
1649 enomem0:
1650         DBG (dev, "%s enomem\n", __func__);
1651         destroy_ep_files (dev);
1652         return -ENOMEM;
1653 }
1654
1655 static void
1656 gadgetfs_unbind (struct usb_gadget *gadget)
1657 {
1658         struct dev_data         *dev = get_gadget_data (gadget);
1659
1660         DBG (dev, "%s\n", __func__);
1661
1662         spin_lock_irq (&dev->lock);
1663         dev->state = STATE_DEV_UNBOUND;
1664         spin_unlock_irq (&dev->lock);
1665
1666         destroy_ep_files (dev);
1667         gadget->ep0->driver_data = NULL;
1668         set_gadget_data (gadget, NULL);
1669
1670         /* we've already been disconnected ... no i/o is active */
1671         if (dev->req)
1672                 usb_ep_free_request (gadget->ep0, dev->req);
1673         DBG (dev, "%s done\n", __func__);
1674         put_dev (dev);
1675 }
1676
1677 static struct dev_data          *the_device;
1678
1679 static int gadgetfs_bind(struct usb_gadget *gadget,
1680                 struct usb_gadget_driver *driver)
1681 {
1682         struct dev_data         *dev = the_device;
1683
1684         if (!dev)
1685                 return -ESRCH;
1686         if (0 != strcmp (CHIP, gadget->name)) {
1687                 pr_err("%s expected %s controller not %s\n",
1688                         shortname, CHIP, gadget->name);
1689                 return -ENODEV;
1690         }
1691
1692         set_gadget_data (gadget, dev);
1693         dev->gadget = gadget;
1694         gadget->ep0->driver_data = dev;
1695
1696         /* preallocate control response and buffer */
1697         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1698         if (!dev->req)
1699                 goto enomem;
1700         dev->req->context = NULL;
1701         dev->req->complete = epio_complete;
1702
1703         if (activate_ep_files (dev) < 0)
1704                 goto enomem;
1705
1706         INFO (dev, "bound to %s driver\n", gadget->name);
1707         spin_lock_irq(&dev->lock);
1708         dev->state = STATE_DEV_UNCONNECTED;
1709         spin_unlock_irq(&dev->lock);
1710         get_dev (dev);
1711         return 0;
1712
1713 enomem:
1714         gadgetfs_unbind (gadget);
1715         return -ENOMEM;
1716 }
1717
1718 static void
1719 gadgetfs_disconnect (struct usb_gadget *gadget)
1720 {
1721         struct dev_data         *dev = get_gadget_data (gadget);
1722         unsigned long           flags;
1723
1724         spin_lock_irqsave (&dev->lock, flags);
1725         if (dev->state == STATE_DEV_UNCONNECTED)
1726                 goto exit;
1727         dev->state = STATE_DEV_UNCONNECTED;
1728
1729         INFO (dev, "disconnected\n");
1730         next_event (dev, GADGETFS_DISCONNECT);
1731         ep0_readable (dev);
1732 exit:
1733         spin_unlock_irqrestore (&dev->lock, flags);
1734 }
1735
1736 static void
1737 gadgetfs_suspend (struct usb_gadget *gadget)
1738 {
1739         struct dev_data         *dev = get_gadget_data (gadget);
1740
1741         INFO (dev, "suspended from state %d\n", dev->state);
1742         spin_lock (&dev->lock);
1743         switch (dev->state) {
1744         case STATE_DEV_SETUP:           // VERY odd... host died??
1745         case STATE_DEV_CONNECTED:
1746         case STATE_DEV_UNCONNECTED:
1747                 next_event (dev, GADGETFS_SUSPEND);
1748                 ep0_readable (dev);
1749                 /* FALLTHROUGH */
1750         default:
1751                 break;
1752         }
1753         spin_unlock (&dev->lock);
1754 }
1755
1756 static struct usb_gadget_driver gadgetfs_driver = {
1757         .function       = (char *) driver_desc,
1758         .bind           = gadgetfs_bind,
1759         .unbind         = gadgetfs_unbind,
1760         .setup          = gadgetfs_setup,
1761         .disconnect     = gadgetfs_disconnect,
1762         .suspend        = gadgetfs_suspend,
1763
1764         .driver = {
1765                 .name           = (char *) shortname,
1766         },
1767 };
1768
1769 /*----------------------------------------------------------------------*/
1770
1771 static void gadgetfs_nop(struct usb_gadget *arg) { }
1772
1773 static int gadgetfs_probe(struct usb_gadget *gadget,
1774                 struct usb_gadget_driver *driver)
1775 {
1776         CHIP = gadget->name;
1777         return -EISNAM;
1778 }
1779
1780 static struct usb_gadget_driver probe_driver = {
1781         .max_speed      = USB_SPEED_HIGH,
1782         .bind           = gadgetfs_probe,
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
1897         value = usb_gadget_probe_driver(&gadgetfs_driver);
1898         if (value != 0) {
1899                 kfree (dev->buf);
1900                 dev->buf = NULL;
1901         } else {
1902                 /* at this point "good" hardware has for the first time
1903                  * let the USB the host see us.  alternatively, if users
1904                  * unplug/replug that will clear all the error state.
1905                  *
1906                  * note:  everything running before here was guaranteed
1907                  * to choke driver model style diagnostics.  from here
1908                  * on, they can work ... except in cleanup paths that
1909                  * kick in after the ep0 descriptor is closed.
1910                  */
1911                 fd->f_op = &ep0_io_operations;
1912                 value = len;
1913         }
1914         return value;
1915
1916 fail:
1917         spin_unlock_irq (&dev->lock);
1918         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1919         kfree (dev->buf);
1920         dev->buf = NULL;
1921         return value;
1922 }
1923
1924 static int
1925 dev_open (struct inode *inode, struct file *fd)
1926 {
1927         struct dev_data         *dev = inode->i_private;
1928         int                     value = -EBUSY;
1929
1930         spin_lock_irq(&dev->lock);
1931         if (dev->state == STATE_DEV_DISABLED) {
1932                 dev->ev_next = 0;
1933                 dev->state = STATE_DEV_OPENED;
1934                 fd->private_data = dev;
1935                 get_dev (dev);
1936                 value = 0;
1937         }
1938         spin_unlock_irq(&dev->lock);
1939         return value;
1940 }
1941
1942 static const struct file_operations dev_init_operations = {
1943         .owner =        THIS_MODULE,
1944         .llseek =       no_llseek,
1945
1946         .open =         dev_open,
1947         .write =        dev_config,
1948         .fasync =       ep0_fasync,
1949         .unlocked_ioctl = dev_ioctl,
1950         .release =      dev_release,
1951 };
1952
1953 /*----------------------------------------------------------------------*/
1954
1955 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1956  *
1957  * Mounting the filesystem creates a controller file, used first for
1958  * device configuration then later for event monitoring.
1959  */
1960
1961
1962 /* FIXME PAM etc could set this security policy without mount options
1963  * if epfiles inherited ownership and permissons from ep0 ...
1964  */
1965
1966 static unsigned default_uid;
1967 static unsigned default_gid;
1968 static unsigned default_perm = S_IRUSR | S_IWUSR;
1969
1970 module_param (default_uid, uint, 0644);
1971 module_param (default_gid, uint, 0644);
1972 module_param (default_perm, uint, 0644);
1973
1974
1975 static struct inode *
1976 gadgetfs_make_inode (struct super_block *sb,
1977                 void *data, const struct file_operations *fops,
1978                 int mode)
1979 {
1980         struct inode *inode = new_inode (sb);
1981
1982         if (inode) {
1983                 inode->i_ino = get_next_ino();
1984                 inode->i_mode = mode;
1985                 inode->i_uid = make_kuid(&init_user_ns, default_uid);
1986                 inode->i_gid = make_kgid(&init_user_ns, default_gid);
1987                 inode->i_atime = inode->i_mtime = inode->i_ctime
1988                                 = CURRENT_TIME;
1989                 inode->i_private = data;
1990                 inode->i_fop = fops;
1991         }
1992         return inode;
1993 }
1994
1995 /* creates in fs root directory, so non-renamable and non-linkable.
1996  * so inode and dentry are paired, until device reconfig.
1997  */
1998 static struct inode *
1999 gadgetfs_create_file (struct super_block *sb, char const *name,
2000                 void *data, const struct file_operations *fops,
2001                 struct dentry **dentry_p)
2002 {
2003         struct dentry   *dentry;
2004         struct inode    *inode;
2005
2006         dentry = d_alloc_name(sb->s_root, name);
2007         if (!dentry)
2008                 return NULL;
2009
2010         inode = gadgetfs_make_inode (sb, data, fops,
2011                         S_IFREG | (default_perm & S_IRWXUGO));
2012         if (!inode) {
2013                 dput(dentry);
2014                 return NULL;
2015         }
2016         d_add (dentry, inode);
2017         *dentry_p = dentry;
2018         return inode;
2019 }
2020
2021 static const struct super_operations gadget_fs_operations = {
2022         .statfs =       simple_statfs,
2023         .drop_inode =   generic_delete_inode,
2024 };
2025
2026 static int
2027 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2028 {
2029         struct inode    *inode;
2030         struct dev_data *dev;
2031
2032         if (the_device)
2033                 return -ESRCH;
2034
2035         /* fake probe to determine $CHIP */
2036         usb_gadget_probe_driver(&probe_driver);
2037         if (!CHIP)
2038                 return -ENODEV;
2039
2040         /* superblock */
2041         sb->s_blocksize = PAGE_CACHE_SIZE;
2042         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2043         sb->s_magic = GADGETFS_MAGIC;
2044         sb->s_op = &gadget_fs_operations;
2045         sb->s_time_gran = 1;
2046
2047         /* root inode */
2048         inode = gadgetfs_make_inode (sb,
2049                         NULL, &simple_dir_operations,
2050                         S_IFDIR | S_IRUGO | S_IXUGO);
2051         if (!inode)
2052                 goto Enomem;
2053         inode->i_op = &simple_dir_inode_operations;
2054         if (!(sb->s_root = d_make_root (inode)))
2055                 goto Enomem;
2056
2057         /* the ep0 file is named after the controller we expect;
2058          * user mode code can use it for sanity checks, like we do.
2059          */
2060         dev = dev_new ();
2061         if (!dev)
2062                 goto Enomem;
2063
2064         dev->sb = sb;
2065         if (!gadgetfs_create_file (sb, CHIP,
2066                                 dev, &dev_init_operations,
2067                                 &dev->dentry)) {
2068                 put_dev(dev);
2069                 goto Enomem;
2070         }
2071
2072         /* other endpoint files are available after hardware setup,
2073          * from binding to a controller.
2074          */
2075         the_device = dev;
2076         return 0;
2077
2078 Enomem:
2079         return -ENOMEM;
2080 }
2081
2082 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2083 static struct dentry *
2084 gadgetfs_mount (struct file_system_type *t, int flags,
2085                 const char *path, void *opts)
2086 {
2087         return mount_single (t, flags, opts, gadgetfs_fill_super);
2088 }
2089
2090 static void
2091 gadgetfs_kill_sb (struct super_block *sb)
2092 {
2093         kill_litter_super (sb);
2094         if (the_device) {
2095                 put_dev (the_device);
2096                 the_device = NULL;
2097         }
2098 }
2099
2100 /*----------------------------------------------------------------------*/
2101
2102 static struct file_system_type gadgetfs_type = {
2103         .owner          = THIS_MODULE,
2104         .name           = shortname,
2105         .mount          = gadgetfs_mount,
2106         .kill_sb        = gadgetfs_kill_sb,
2107 };
2108
2109 /*----------------------------------------------------------------------*/
2110
2111 static int __init init (void)
2112 {
2113         int status;
2114
2115         status = register_filesystem (&gadgetfs_type);
2116         if (status == 0)
2117                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2118                         shortname, driver_desc);
2119         return status;
2120 }
2121 module_init (init);
2122
2123 static void __exit cleanup (void)
2124 {
2125         pr_debug ("unregister %s\n", shortname);
2126         unregister_filesystem (&gadgetfs_type);
2127 }
2128 module_exit (cleanup);
2129