drivers/usb/gadget/legacy/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 #include <linux/mmu_context.h>
  28 #include <linux/aio.h>
  29
  30 #include <linux/device.h>
  31 #include <linux/moduleparam.h>
  32
  33 #include <linux/usb/gadgetfs.h>
  34 #include <linux/usb/gadget.h>
  35
  36
  37 /*
  38  * The gadgetfs API maps each endpoint to a file descriptor so that you
  39  * can use standard synchronous read/write calls for I/O.  There's some
  40  * O_NONBLOCK and O_ASYNC/FASYNC style i/o support.  Example usermode
  41  * drivers show how this works in practice.  You can also use AIO to
  42  * eliminate I/O gaps between requests, to help when streaming data.
  43  *
  44  * Key parts that must be USB-specific are protocols defining how the
  45  * read/write operations relate to the hardware state machines.  There
  46  * are two types of files.  One type is for the device, implementing ep0.
  47  * The other type is for each IN or OUT endpoint.  In both cases, the
  48  * user mode driver must configure the hardware before using it.
  49  *
  50  * - First, dev_config() is called when /dev/gadget/$CHIP is configured
  51  *   (by writing configuration and device descriptors).  Afterwards it
  52  *   may serve as a source of device events, used to handle all control
  53  *   requests other than basic enumeration.
  54  *
  55  * - Then, after a SET_CONFIGURATION control request, ep_config() is
  56  *   called when each /dev/gadget/ep* file is configured (by writing
  57  *   endpoint descriptors).  Afterwards these files are used to write()
  58  *   IN data or to read() OUT data.  To halt the endpoint, a "wrong
  59  *   direction" request is issued (like reading an IN endpoint).
  60  *
  61  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
  62  * not possible on all hardware.  For example, precise fault handling with
  63  * respect to data left in endpoint fifos after aborted operations; or
  64  * selective clearing of endpoint halts, to implement SET_INTERFACE.
  65  */
  66
  67 #define DRIVER_DESC     "USB Gadget filesystem"
  68 #define DRIVER_VERSION  "24 Aug 2004"
  69
  70 static const char driver_desc [] = DRIVER_DESC;
  71 static const char shortname [] = "gadgetfs";
  72
  73 MODULE_DESCRIPTION (DRIVER_DESC);
  74 MODULE_AUTHOR ("David Brownell");
  75 MODULE_LICENSE ("GPL");
  76
  77
  78 /*----------------------------------------------------------------------*/
  79
  80 #define GADGETFS_MAGIC          0xaee71ee7
  81
  82 /* /dev/gadget/$CHIP represents ep0 and the whole device */
  83 enum ep0_state {
  84         /* DISBLED is the initial state.
  85          */
  86         STATE_DEV_DISABLED = 0,
  87
  88         /* Only one open() of /dev/gadget/$CHIP; only one file tracks
  89          * ep0/device i/o modes and binding to the controller.  Driver
  90          * must always write descriptors to initialize the device, then
  91          * the device becomes UNCONNECTED until enumeration.
  92          */
  93         STATE_DEV_OPENED,
  94
  95         /* From then on, ep0 fd is in either of two basic modes:
  96          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
  97          * - SETUP: read/write will transfer control data and succeed;
  98          *   or if "wrong direction", performs protocol stall
  99          */
 100         STATE_DEV_UNCONNECTED,
 101         STATE_DEV_CONNECTED,
 102         STATE_DEV_SETUP,
 103
 104         /* UNBOUND means the driver closed ep0, so the device won't be
 105          * accessible again (DEV_DISABLED) until all fds are closed.
 106          */
 107         STATE_DEV_UNBOUND,
 108 };
 109
 110 /* enough for the whole queue: most events invalidate others */
 111 #define N_EVENT                 5
 112
 113 struct dev_data {
 114         spinlock_t                      lock;
 115         atomic_t                        count;
 116         enum ep0_state                  state;          /* P: lock */
 117         struct usb_gadgetfs_event       event [N_EVENT];
 118         unsigned                        ev_next;
 119         struct fasync_struct            *fasync;
 120         u8                              current_config;
 121
 122         /* drivers reading ep0 MUST handle control requests (SETUP)
 123          * reported that way; else the host will time out.
 124          */
 125         unsigned                        usermode_setup : 1,
 126                                         setup_in : 1,
 127                                         setup_can_stall : 1,
 128                                         setup_out_ready : 1,
 129                                         setup_out_error : 1,
 130                                         setup_abort : 1;
 131         unsigned                        setup_wLength;
 132
 133         /* the rest is basically write-once */
 134         struct usb_config_descriptor    *config, *hs_config;
 135         struct usb_device_descriptor    *dev;
 136         struct usb_request              *req;
 137         struct usb_gadget               *gadget;
 138         struct list_head                epfiles;
 139         void                            *buf;
 140         wait_queue_head_t               wait;
 141         struct super_block              *sb;
 142         struct dentry                   *dentry;
 143
 144         /* except this scratch i/o buffer for ep0 */
 145         u8                              rbuf [256];
 146 };
 147
 148 static inline void get_dev (struct dev_data *data)
 149 {
 150         atomic_inc (&data->count);
 151 }
 152
 153 static void put_dev (struct dev_data *data)
 154 {
 155         if (likely (!atomic_dec_and_test (&data->count)))
 156                 return;
 157         /* needs no more cleanup */
 158         BUG_ON (waitqueue_active (&data->wait));
 159         kfree (data);
 160 }
 161
 162 static struct dev_data *dev_new (void)
 163 {
 164         struct dev_data         *dev;
 165
 166         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 167         if (!dev)
 168                 return NULL;
 169         dev->state = STATE_DEV_DISABLED;
 170         atomic_set (&dev->count, 1);
 171         spin_lock_init (&dev->lock);
 172         INIT_LIST_HEAD (&dev->epfiles);
 173         init_waitqueue_head (&dev->wait);
 174         return dev;
 175 }
 176
 177 /*----------------------------------------------------------------------*/
 178
 179 /* other /dev/gadget/$ENDPOINT files represent endpoints */
 180 enum ep_state {
 181         STATE_EP_DISABLED = 0,
 182         STATE_EP_READY,
 183         STATE_EP_ENABLED,
 184         STATE_EP_UNBOUND,
 185 };
 186
 187 struct ep_data {
 188         struct mutex                    lock;
 189         enum ep_state                   state;
 190         atomic_t                        count;
 191         struct dev_data                 *dev;
 192         /* must hold dev->lock before accessing ep or req */
 193         struct usb_ep                   *ep;
 194         struct usb_request              *req;
 195         ssize_t                         status;
 196         char                            name [16];
 197         struct usb_endpoint_descriptor  desc, hs_desc;
 198         struct list_head                epfiles;
 199         wait_queue_head_t               wait;
 200         struct dentry                   *dentry;
 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 = memdup_user(buf, len);
 442         if (IS_ERR(kbuf)) {
 443                 value = PTR_ERR(kbuf);
 444                 kbuf = NULL;
 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         struct kiocb            *iocb;
 517         struct mm_struct        *mm;
 518         struct work_struct      work;
 519         void                    *buf;
 520         const struct iovec      *iv;
 521         unsigned long           nr_segs;
 522         unsigned                actual;
 523 };
 524
 525 static int ep_aio_cancel(struct kiocb *iocb)
 526 {
 527         struct kiocb_priv       *priv = iocb->private;
 528         struct ep_data          *epdata;
 529         int                     value;
 530
 531         local_irq_disable();
 532         epdata = priv->epdata;
 533         // spin_lock(&epdata->dev->lock);
 534         if (likely(epdata && epdata->ep && priv->req))
 535                 value = usb_ep_dequeue (epdata->ep, priv->req);
 536         else
 537                 value = -EINVAL;
 538         // spin_unlock(&epdata->dev->lock);
 539         local_irq_enable();
 540
 541         return value;
 542 }
 543
 544 static ssize_t ep_copy_to_user(struct kiocb_priv *priv)
 545 {
 546         ssize_t                 len, total;
 547         void                    *to_copy;
 548         int                     i;
 549
 550         /* copy stuff into user buffers */
 551         total = priv->actual;
 552         len = 0;
 553         to_copy = priv->buf;
 554         for (i=0; i < priv->nr_segs; i++) {
 555                 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
 556
 557                 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
 558                         if (len == 0)
 559                                 len = -EFAULT;
 560                         break;
 561                 }
 562
 563                 total -= this;
 564                 len += this;
 565                 to_copy += this;
 566                 if (total == 0)
 567                         break;
 568         }
 569
 570         return len;
 571 }
 572
 573 static void ep_user_copy_worker(struct work_struct *work)
 574 {
 575         struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work);
 576         struct mm_struct *mm = priv->mm;
 577         struct kiocb *iocb = priv->iocb;
 578         size_t ret;
 579
 580         use_mm(mm);
 581         ret = ep_copy_to_user(priv);
 582         unuse_mm(mm);
 583
 584         /* completing the iocb can drop the ctx and mm, don't touch mm after */
 585         aio_complete(iocb, ret, ret);
 586
 587         kfree(priv->buf);
 588         kfree(priv);
 589 }
 590
 591 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 592 {
 593         struct kiocb            *iocb = req->context;
 594         struct kiocb_priv       *priv = iocb->private;
 595         struct ep_data          *epdata = priv->epdata;
 596
 597         /* lock against disconnect (and ideally, cancel) */
 598         spin_lock(&epdata->dev->lock);
 599         priv->req = NULL;
 600         priv->epdata = NULL;
 601
 602         /* if this was a write or a read returning no data then we
 603          * don't need to copy anything to userspace, so we can
 604          * complete the aio request immediately.
 605          */
 606         if (priv->iv == NULL || unlikely(req->actual == 0)) {
 607                 kfree(req->buf);
 608                 kfree(priv);
 609                 iocb->private = NULL;
 610                 /* aio_complete() reports bytes-transferred _and_ faults */
 611                 aio_complete(iocb, req->actual ? req->actual : req->status,
 612                                 req->status);
 613         } else {
 614                 /* ep_copy_to_user() won't report both; we hide some faults */
 615                 if (unlikely(0 != req->status))
 616                         DBG(epdata->dev, "%s fault %d len %d\n",
 617                                 ep->name, req->status, req->actual);
 618
 619                 priv->buf = req->buf;
 620                 priv->actual = req->actual;
 621                 schedule_work(&priv->work);
 622         }
 623         spin_unlock(&epdata->dev->lock);
 624
 625         usb_ep_free_request(ep, req);
 626         put_ep(epdata);
 627 }
 628
 629 static ssize_t
 630 ep_aio_rwtail(
 631         struct kiocb    *iocb,
 632         char            *buf,
 633         size_t          len,
 634         struct ep_data  *epdata,
 635         const struct iovec *iv,
 636         unsigned long   nr_segs
 637 )
 638 {
 639         struct kiocb_priv       *priv;
 640         struct usb_request      *req;
 641         ssize_t                 value;
 642
 643         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 644         if (!priv) {
 645                 value = -ENOMEM;
 646 fail:
 647                 kfree(buf);
 648                 return value;
 649         }
 650         iocb->private = priv;
 651         priv->iocb = iocb;
 652         priv->iv = iv;
 653         priv->nr_segs = nr_segs;
 654         INIT_WORK(&priv->work, ep_user_copy_worker);
 655
 656         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 657         if (unlikely(value < 0)) {
 658                 kfree(priv);
 659                 goto fail;
 660         }
 661
 662         kiocb_set_cancel_fn(iocb, ep_aio_cancel);
 663         get_ep(epdata);
 664         priv->epdata = epdata;
 665         priv->actual = 0;
 666         priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */
 667
 668         /* each kiocb is coupled to one usb_request, but we can't
 669          * allocate or submit those if the host disconnected.
 670          */
 671         spin_lock_irq(&epdata->dev->lock);
 672         if (likely(epdata->ep)) {
 673                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 674                 if (likely(req)) {
 675                         priv->req = req;
 676                         req->buf = buf;
 677                         req->length = len;
 678                         req->complete = ep_aio_complete;
 679                         req->context = iocb;
 680                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 681                         if (unlikely(0 != value))
 682                                 usb_ep_free_request(epdata->ep, req);
 683                 } else
 684                         value = -EAGAIN;
 685         } else
 686                 value = -ENODEV;
 687         spin_unlock_irq(&epdata->dev->lock);
 688
 689         mutex_unlock(&epdata->lock);
 690
 691         if (unlikely(value)) {
 692                 kfree(priv);
 693                 put_ep(epdata);
 694         } else
 695                 value = -EIOCBQUEUED;
 696         return value;
 697 }
 698
 699 static ssize_t
 700 ep_aio_read(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
 706         if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
 707                 return -EINVAL;
 708
 709         buf = kmalloc(iocb->ki_nbytes, GFP_KERNEL);
 710         if (unlikely(!buf))
 711                 return -ENOMEM;
 712
 713         return ep_aio_rwtail(iocb, buf, iocb->ki_nbytes, epdata, iov, nr_segs);
 714 }
 715
 716 static ssize_t
 717 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
 718                 unsigned long nr_segs, loff_t o)
 719 {
 720         struct ep_data          *epdata = iocb->ki_filp->private_data;
 721         char                    *buf;
 722         size_t                  len = 0;
 723         int                     i = 0;
 724
 725         if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
 726                 return -EINVAL;
 727
 728         buf = kmalloc(iocb->ki_nbytes, GFP_KERNEL);
 729         if (unlikely(!buf))
 730                 return -ENOMEM;
 731
 732         for (i=0; i < nr_segs; i++) {
 733                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
 734                                 iov[i].iov_len) != 0)) {
 735                         kfree(buf);
 736                         return -EFAULT;
 737                 }
 738                 len += iov[i].iov_len;
 739         }
 740         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
 741 }
 742
 743 /*----------------------------------------------------------------------*/
 744
 745 /* used after endpoint configuration */
 746 static const struct file_operations ep_io_operations = {
 747         .owner =        THIS_MODULE,
 748         .llseek =       no_llseek,
 749
 750         .read =         ep_read,
 751         .write =        ep_write,
 752         .unlocked_ioctl = ep_ioctl,
 753         .release =      ep_release,
 754
 755         .aio_read =     ep_aio_read,
 756         .aio_write =    ep_aio_write,
 757 };
 758
 759 /* ENDPOINT INITIALIZATION
 760  *
 761  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 762  *     status = write (fd, descriptors, sizeof descriptors)
 763  *
 764  * That write establishes the endpoint configuration, configuring
 765  * the controller to process bulk, interrupt, or isochronous transfers
 766  * at the right maxpacket size, and so on.
 767  *
 768  * The descriptors are message type 1, identified by a host order u32
 769  * at the beginning of what's written.  Descriptor order is: full/low
 770  * speed descriptor, then optional high speed descriptor.
 771  */
 772 static ssize_t
 773 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 774 {
 775         struct ep_data          *data = fd->private_data;
 776         struct usb_ep           *ep;
 777         u32                     tag;
 778         int                     value, length = len;
 779
 780         value = mutex_lock_interruptible(&data->lock);
 781         if (value < 0)
 782                 return value;
 783
 784         if (data->state != STATE_EP_READY) {
 785                 value = -EL2HLT;
 786                 goto fail;
 787         }
 788
 789         value = len;
 790         if (len < USB_DT_ENDPOINT_SIZE + 4)
 791                 goto fail0;
 792
 793         /* we might need to change message format someday */
 794         if (copy_from_user (&tag, buf, 4)) {
 795                 goto fail1;
 796         }
 797         if (tag != 1) {
 798                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 799                 goto fail0;
 800         }
 801         buf += 4;
 802         len -= 4;
 803
 804         /* NOTE:  audio endpoint extensions not accepted here;
 805          * just don't include the extra bytes.
 806          */
 807
 808         /* full/low speed descriptor, then high speed */
 809         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 810                 goto fail1;
 811         }
 812         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 813                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 814                 goto fail0;
 815         if (len != USB_DT_ENDPOINT_SIZE) {
 816                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 817                         goto fail0;
 818                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 819                                         USB_DT_ENDPOINT_SIZE)) {
 820                         goto fail1;
 821                 }
 822                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 823                                 || data->hs_desc.bDescriptorType
 824                                         != USB_DT_ENDPOINT) {
 825                         DBG(data->dev, "config %s, bad hs length or type\n",
 826                                         data->name);
 827                         goto fail0;
 828                 }
 829         }
 830
 831         spin_lock_irq (&data->dev->lock);
 832         if (data->dev->state == STATE_DEV_UNBOUND) {
 833                 value = -ENOENT;
 834                 goto gone;
 835         } else if ((ep = data->ep) == NULL) {
 836                 value = -ENODEV;
 837                 goto gone;
 838         }
 839         switch (data->dev->gadget->speed) {
 840         case USB_SPEED_LOW:
 841         case USB_SPEED_FULL:
 842                 ep->desc = &data->desc;
 843                 value = usb_ep_enable(ep);
 844                 if (value == 0)
 845                         data->state = STATE_EP_ENABLED;
 846                 break;
 847         case USB_SPEED_HIGH:
 848                 /* fails if caller didn't provide that descriptor... */
 849                 ep->desc = &data->hs_desc;
 850                 value = usb_ep_enable(ep);
 851                 if (value == 0)
 852                         data->state = STATE_EP_ENABLED;
 853                 break;
 854         default:
 855                 DBG(data->dev, "unconnected, %s init abandoned\n",
 856                                 data->name);
 857                 value = -EINVAL;
 858         }
 859         if (value == 0) {
 860                 fd->f_op = &ep_io_operations;
 861                 value = length;
 862         }
 863 gone:
 864         spin_unlock_irq (&data->dev->lock);
 865         if (value < 0) {
 866 fail:
 867                 data->desc.bDescriptorType = 0;
 868                 data->hs_desc.bDescriptorType = 0;
 869         }
 870         mutex_unlock(&data->lock);
 871         return value;
 872 fail0:
 873         value = -EINVAL;
 874         goto fail;
 875 fail1:
 876         value = -EFAULT;
 877         goto fail;
 878 }
 879
 880 static int
 881 ep_open (struct inode *inode, struct file *fd)
 882 {
 883         struct ep_data          *data = inode->i_private;
 884         int                     value = -EBUSY;
 885
 886         if (mutex_lock_interruptible(&data->lock) != 0)
 887                 return -EINTR;
 888         spin_lock_irq (&data->dev->lock);
 889         if (data->dev->state == STATE_DEV_UNBOUND)
 890                 value = -ENOENT;
 891         else if (data->state == STATE_EP_DISABLED) {
 892                 value = 0;
 893                 data->state = STATE_EP_READY;
 894                 get_ep (data);
 895                 fd->private_data = data;
 896                 VDEBUG (data->dev, "%s ready\n", data->name);
 897         } else
 898                 DBG (data->dev, "%s state %d\n",
 899                         data->name, data->state);
 900         spin_unlock_irq (&data->dev->lock);
 901         mutex_unlock(&data->lock);
 902         return value;
 903 }
 904
 905 /* used before endpoint configuration */
 906 static const struct file_operations ep_config_operations = {
 907         .llseek =       no_llseek,
 908
 909         .open =         ep_open,
 910         .write =        ep_config,
 911         .release =      ep_release,
 912 };
 913
 914 /*----------------------------------------------------------------------*/
 915
 916 /* EP0 IMPLEMENTATION can be partly in userspace.
 917  *
 918  * Drivers that use this facility receive various events, including
 919  * control requests the kernel doesn't handle.  Drivers that don't
 920  * use this facility may be too simple-minded for real applications.
 921  */
 922
 923 static inline void ep0_readable (struct dev_data *dev)
 924 {
 925         wake_up (&dev->wait);
 926         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 927 }
 928
 929 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 930 {
 931         struct dev_data         *dev = ep->driver_data;
 932
 933         if (req->buf != dev->rbuf) {
 934                 kfree(req->buf);
 935                 req->buf = dev->rbuf;
 936         }
 937         req->complete = epio_complete;
 938         dev->setup_out_ready = 0;
 939 }
 940
 941 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 942 {
 943         struct dev_data         *dev = ep->driver_data;
 944         unsigned long           flags;
 945         int                     free = 1;
 946
 947         /* for control OUT, data must still get to userspace */
 948         spin_lock_irqsave(&dev->lock, flags);
 949         if (!dev->setup_in) {
 950                 dev->setup_out_error = (req->status != 0);
 951                 if (!dev->setup_out_error)
 952                         free = 0;
 953                 dev->setup_out_ready = 1;
 954                 ep0_readable (dev);
 955         }
 956
 957         /* clean up as appropriate */
 958         if (free && req->buf != &dev->rbuf)
 959                 clean_req (ep, req);
 960         req->complete = epio_complete;
 961         spin_unlock_irqrestore(&dev->lock, flags);
 962 }
 963
 964 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 965 {
 966         struct dev_data *dev = ep->driver_data;
 967
 968         if (dev->setup_out_ready) {
 969                 DBG (dev, "ep0 request busy!\n");
 970                 return -EBUSY;
 971         }
 972         if (len > sizeof (dev->rbuf))
 973                 req->buf = kmalloc(len, GFP_ATOMIC);
 974         if (req->buf == NULL) {
 975                 req->buf = dev->rbuf;
 976                 return -ENOMEM;
 977         }
 978         req->complete = ep0_complete;
 979         req->length = len;
 980         req->zero = 0;
 981         return 0;
 982 }
 983
 984 static ssize_t
 985 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 986 {
 987         struct dev_data                 *dev = fd->private_data;
 988         ssize_t                         retval;
 989         enum ep0_state                  state;
 990
 991         spin_lock_irq (&dev->lock);
 992
 993         /* report fd mode change before acting on it */
 994         if (dev->setup_abort) {
 995                 dev->setup_abort = 0;
 996                 retval = -EIDRM;
 997                 goto done;
 998         }
 999
1000         /* control DATA stage */
1001         if ((state = dev->state) == STATE_DEV_SETUP) {
1002
1003                 if (dev->setup_in) {            /* stall IN */
1004                         VDEBUG(dev, "ep0in stall\n");
1005                         (void) usb_ep_set_halt (dev->gadget->ep0);
1006                         retval = -EL2HLT;
1007                         dev->state = STATE_DEV_CONNECTED;
1008
1009                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
1010                         struct usb_ep           *ep = dev->gadget->ep0;
1011                         struct usb_request      *req = dev->req;
1012
1013                         if ((retval = setup_req (ep, req, 0)) == 0)
1014                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1015                         dev->state = STATE_DEV_CONNECTED;
1016
1017                         /* assume that was SET_CONFIGURATION */
1018                         if (dev->current_config) {
1019                                 unsigned power;
1020
1021                                 if (gadget_is_dualspeed(dev->gadget)
1022                                                 && (dev->gadget->speed
1023                                                         == USB_SPEED_HIGH))
1024                                         power = dev->hs_config->bMaxPower;
1025                                 else
1026                                         power = dev->config->bMaxPower;
1027                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1028                         }
1029
1030                 } else {                        /* collect OUT data */
1031                         if ((fd->f_flags & O_NONBLOCK) != 0
1032                                         && !dev->setup_out_ready) {
1033                                 retval = -EAGAIN;
1034                                 goto done;
1035                         }
1036                         spin_unlock_irq (&dev->lock);
1037                         retval = wait_event_interruptible (dev->wait,
1038                                         dev->setup_out_ready != 0);
1039
1040                         /* FIXME state could change from under us */
1041                         spin_lock_irq (&dev->lock);
1042                         if (retval)
1043                                 goto done;
1044
1045                         if (dev->state != STATE_DEV_SETUP) {
1046                                 retval = -ECANCELED;
1047                                 goto done;
1048                         }
1049                         dev->state = STATE_DEV_CONNECTED;
1050
1051                         if (dev->setup_out_error)
1052                                 retval = -EIO;
1053                         else {
1054                                 len = min (len, (size_t)dev->req->actual);
1055 // FIXME don't call this with the spinlock held ...
1056                                 if (copy_to_user (buf, dev->req->buf, len))
1057                                         retval = -EFAULT;
1058                                 else
1059                                         retval = len;
1060                                 clean_req (dev->gadget->ep0, dev->req);
1061                                 /* NOTE userspace can't yet choose to stall */
1062                         }
1063                 }
1064                 goto done;
1065         }
1066
1067         /* else normal: return event data */
1068         if (len < sizeof dev->event [0]) {
1069                 retval = -EINVAL;
1070                 goto done;
1071         }
1072         len -= len % sizeof (struct usb_gadgetfs_event);
1073         dev->usermode_setup = 1;
1074
1075 scan:
1076         /* return queued events right away */
1077         if (dev->ev_next != 0) {
1078                 unsigned                i, n;
1079
1080                 n = len / sizeof (struct usb_gadgetfs_event);
1081                 if (dev->ev_next < n)
1082                         n = dev->ev_next;
1083
1084                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1085                 for (i = 0; i < n; i++) {
1086                         if (dev->event [i].type == GADGETFS_SETUP) {
1087                                 dev->state = STATE_DEV_SETUP;
1088                                 n = i + 1;
1089                                 break;
1090                         }
1091                 }
1092                 spin_unlock_irq (&dev->lock);
1093                 len = n * sizeof (struct usb_gadgetfs_event);
1094                 if (copy_to_user (buf, &dev->event, len))
1095                         retval = -EFAULT;
1096                 else
1097                         retval = len;
1098                 if (len > 0) {
1099                         /* NOTE this doesn't guard against broken drivers;
1100                          * concurrent ep0 readers may lose events.
1101                          */
1102                         spin_lock_irq (&dev->lock);
1103                         if (dev->ev_next > n) {
1104                                 memmove(&dev->event[0], &dev->event[n],
1105                                         sizeof (struct usb_gadgetfs_event)
1106                                                 * (dev->ev_next - n));
1107                         }
1108                         dev->ev_next -= n;
1109                         spin_unlock_irq (&dev->lock);
1110                 }
1111                 return retval;
1112         }
1113         if (fd->f_flags & O_NONBLOCK) {
1114                 retval = -EAGAIN;
1115                 goto done;
1116         }
1117
1118         switch (state) {
1119         default:
1120                 DBG (dev, "fail %s, state %d\n", __func__, state);
1121                 retval = -ESRCH;
1122                 break;
1123         case STATE_DEV_UNCONNECTED:
1124         case STATE_DEV_CONNECTED:
1125                 spin_unlock_irq (&dev->lock);
1126                 DBG (dev, "%s wait\n", __func__);
1127
1128                 /* wait for events */
1129                 retval = wait_event_interruptible (dev->wait,
1130                                 dev->ev_next != 0);
1131                 if (retval < 0)
1132                         return retval;
1133                 spin_lock_irq (&dev->lock);
1134                 goto scan;
1135         }
1136
1137 done:
1138         spin_unlock_irq (&dev->lock);
1139         return retval;
1140 }
1141
1142 static struct usb_gadgetfs_event *
1143 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1144 {
1145         struct usb_gadgetfs_event       *event;
1146         unsigned                        i;
1147
1148         switch (type) {
1149         /* these events purge the queue */
1150         case GADGETFS_DISCONNECT:
1151                 if (dev->state == STATE_DEV_SETUP)
1152                         dev->setup_abort = 1;
1153                 // FALL THROUGH
1154         case GADGETFS_CONNECT:
1155                 dev->ev_next = 0;
1156                 break;
1157         case GADGETFS_SETUP:            /* previous request timed out */
1158         case GADGETFS_SUSPEND:          /* same effect */
1159                 /* these events can't be repeated */
1160                 for (i = 0; i != dev->ev_next; i++) {
1161                         if (dev->event [i].type != type)
1162                                 continue;
1163                         DBG(dev, "discard old event[%d] %d\n", i, type);
1164                         dev->ev_next--;
1165                         if (i == dev->ev_next)
1166                                 break;
1167                         /* indices start at zero, for simplicity */
1168                         memmove (&dev->event [i], &dev->event [i + 1],
1169                                 sizeof (struct usb_gadgetfs_event)
1170                                         * (dev->ev_next - i));
1171                 }
1172                 break;
1173         default:
1174                 BUG ();
1175         }
1176         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1177         event = &dev->event [dev->ev_next++];
1178         BUG_ON (dev->ev_next > N_EVENT);
1179         memset (event, 0, sizeof *event);
1180         event->type = type;
1181         return event;
1182 }
1183
1184 static ssize_t
1185 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1186 {
1187         struct dev_data         *dev = fd->private_data;
1188         ssize_t                 retval = -ESRCH;
1189
1190         spin_lock_irq (&dev->lock);
1191
1192         /* report fd mode change before acting on it */
1193         if (dev->setup_abort) {
1194                 dev->setup_abort = 0;
1195                 retval = -EIDRM;
1196
1197         /* data and/or status stage for control request */
1198         } else if (dev->state == STATE_DEV_SETUP) {
1199
1200                 /* IN DATA+STATUS caller makes len <= wLength */
1201                 if (dev->setup_in) {
1202                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1203                         if (retval == 0) {
1204                                 dev->state = STATE_DEV_CONNECTED;
1205                                 spin_unlock_irq (&dev->lock);
1206                                 if (copy_from_user (dev->req->buf, buf, len))
1207                                         retval = -EFAULT;
1208                                 else {
1209                                         if (len < dev->setup_wLength)
1210                                                 dev->req->zero = 1;
1211                                         retval = usb_ep_queue (
1212                                                 dev->gadget->ep0, dev->req,
1213                                                 GFP_KERNEL);
1214                                 }
1215                                 if (retval < 0) {
1216                                         spin_lock_irq (&dev->lock);
1217                                         clean_req (dev->gadget->ep0, dev->req);
1218                                         spin_unlock_irq (&dev->lock);
1219                                 } else
1220                                         retval = len;
1221
1222                                 return retval;
1223                         }
1224
1225                 /* can stall some OUT transfers */
1226                 } else if (dev->setup_can_stall) {
1227                         VDEBUG(dev, "ep0out stall\n");
1228                         (void) usb_ep_set_halt (dev->gadget->ep0);
1229                         retval = -EL2HLT;
1230                         dev->state = STATE_DEV_CONNECTED;
1231                 } else {
1232                         DBG(dev, "bogus ep0out stall!\n");
1233                 }
1234         } else
1235                 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1236
1237         spin_unlock_irq (&dev->lock);
1238         return retval;
1239 }
1240
1241 static int
1242 ep0_fasync (int f, struct file *fd, int on)
1243 {
1244         struct dev_data         *dev = fd->private_data;
1245         // caller must F_SETOWN before signal delivery happens
1246         VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1247         return fasync_helper (f, fd, on, &dev->fasync);
1248 }
1249
1250 static struct usb_gadget_driver gadgetfs_driver;
1251
1252 static int
1253 dev_release (struct inode *inode, struct file *fd)
1254 {
1255         struct dev_data         *dev = fd->private_data;
1256
1257         /* closing ep0 === shutdown all */
1258
1259         usb_gadget_unregister_driver (&gadgetfs_driver);
1260
1261         /* at this point "good" hardware has disconnected the
1262          * device from USB; the host won't see it any more.
1263          * alternatively, all host requests will time out.
1264          */
1265
1266         kfree (dev->buf);
1267         dev->buf = NULL;
1268
1269         /* other endpoints were all decoupled from this device */
1270         spin_lock_irq(&dev->lock);
1271         dev->state = STATE_DEV_DISABLED;
1272         spin_unlock_irq(&dev->lock);
1273
1274         put_dev (dev);
1275         return 0;
1276 }
1277
1278 static unsigned int
1279 ep0_poll (struct file *fd, poll_table *wait)
1280 {
1281        struct dev_data         *dev = fd->private_data;
1282        int                     mask = 0;
1283
1284        poll_wait(fd, &dev->wait, wait);
1285
1286        spin_lock_irq (&dev->lock);
1287
1288        /* report fd mode change before acting on it */
1289        if (dev->setup_abort) {
1290                dev->setup_abort = 0;
1291                mask = POLLHUP;
1292                goto out;
1293        }
1294
1295        if (dev->state == STATE_DEV_SETUP) {
1296                if (dev->setup_in || dev->setup_can_stall)
1297                        mask = POLLOUT;
1298        } else {
1299                if (dev->ev_next != 0)
1300                        mask = POLLIN;
1301        }
1302 out:
1303        spin_unlock_irq(&dev->lock);
1304        return mask;
1305 }
1306
1307 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1308 {
1309         struct dev_data         *dev = fd->private_data;
1310         struct usb_gadget       *gadget = dev->gadget;
1311         long ret = -ENOTTY;
1312
1313         if (gadget->ops->ioctl)
1314                 ret = gadget->ops->ioctl (gadget, code, value);
1315
1316         return ret;
1317 }
1318
1319 /* used after device configuration */
1320 static const struct file_operations ep0_io_operations = {
1321         .owner =        THIS_MODULE,
1322         .llseek =       no_llseek,
1323
1324         .read =         ep0_read,
1325         .write =        ep0_write,
1326         .fasync =       ep0_fasync,
1327         .poll =         ep0_poll,
1328         .unlocked_ioctl =       dev_ioctl,
1329         .release =      dev_release,
1330 };
1331
1332 /*----------------------------------------------------------------------*/
1333
1334 /* The in-kernel gadget driver handles most ep0 issues, in particular
1335  * enumerating the single configuration (as provided from user space).
1336  *
1337  * Unrecognized ep0 requests may be handled in user space.
1338  */
1339
1340 static void make_qualifier (struct dev_data *dev)
1341 {
1342         struct usb_qualifier_descriptor         qual;
1343         struct usb_device_descriptor            *desc;
1344
1345         qual.bLength = sizeof qual;
1346         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1347         qual.bcdUSB = cpu_to_le16 (0x0200);
1348
1349         desc = dev->dev;
1350         qual.bDeviceClass = desc->bDeviceClass;
1351         qual.bDeviceSubClass = desc->bDeviceSubClass;
1352         qual.bDeviceProtocol = desc->bDeviceProtocol;
1353
1354         /* assumes ep0 uses the same value for both speeds ... */
1355         qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1356
1357         qual.bNumConfigurations = 1;
1358         qual.bRESERVED = 0;
1359
1360         memcpy (dev->rbuf, &qual, sizeof qual);
1361 }
1362
1363 static int
1364 config_buf (struct dev_data *dev, u8 type, unsigned index)
1365 {
1366         int             len;
1367         int             hs = 0;
1368
1369         /* only one configuration */
1370         if (index > 0)
1371                 return -EINVAL;
1372
1373         if (gadget_is_dualspeed(dev->gadget)) {
1374                 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1375                 if (type == USB_DT_OTHER_SPEED_CONFIG)
1376                         hs = !hs;
1377         }
1378         if (hs) {
1379                 dev->req->buf = dev->hs_config;
1380                 len = le16_to_cpu(dev->hs_config->wTotalLength);
1381         } else {
1382                 dev->req->buf = dev->config;
1383                 len = le16_to_cpu(dev->config->wTotalLength);
1384         }
1385         ((u8 *)dev->req->buf) [1] = type;
1386         return len;
1387 }
1388
1389 static int
1390 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1391 {
1392         struct dev_data                 *dev = get_gadget_data (gadget);
1393         struct usb_request              *req = dev->req;
1394         int                             value = -EOPNOTSUPP;
1395         struct usb_gadgetfs_event       *event;
1396         u16                             w_value = le16_to_cpu(ctrl->wValue);
1397         u16                             w_length = le16_to_cpu(ctrl->wLength);
1398
1399         spin_lock (&dev->lock);
1400         dev->setup_abort = 0;
1401         if (dev->state == STATE_DEV_UNCONNECTED) {
1402                 if (gadget_is_dualspeed(gadget)
1403                                 && gadget->speed == USB_SPEED_HIGH
1404                                 && dev->hs_config == NULL) {
1405                         spin_unlock(&dev->lock);
1406                         ERROR (dev, "no high speed config??\n");
1407                         return -EINVAL;
1408                 }
1409
1410                 dev->state = STATE_DEV_CONNECTED;
1411
1412                 INFO (dev, "connected\n");
1413                 event = next_event (dev, GADGETFS_CONNECT);
1414                 event->u.speed = gadget->speed;
1415                 ep0_readable (dev);
1416
1417         /* host may have given up waiting for response.  we can miss control
1418          * requests handled lower down (device/endpoint status and features);
1419          * then ep0_{read,write} will report the wrong status. controller
1420          * driver will have aborted pending i/o.
1421          */
1422         } else if (dev->state == STATE_DEV_SETUP)
1423                 dev->setup_abort = 1;
1424
1425         req->buf = dev->rbuf;
1426         req->context = NULL;
1427         value = -EOPNOTSUPP;
1428         switch (ctrl->bRequest) {
1429
1430         case USB_REQ_GET_DESCRIPTOR:
1431                 if (ctrl->bRequestType != USB_DIR_IN)
1432                         goto unrecognized;
1433                 switch (w_value >> 8) {
1434
1435                 case USB_DT_DEVICE:
1436                         value = min (w_length, (u16) sizeof *dev->dev);
1437                         dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1438                         req->buf = dev->dev;
1439                         break;
1440                 case USB_DT_DEVICE_QUALIFIER:
1441                         if (!dev->hs_config)
1442                                 break;
1443                         value = min (w_length, (u16)
1444                                 sizeof (struct usb_qualifier_descriptor));
1445                         make_qualifier (dev);
1446                         break;
1447                 case USB_DT_OTHER_SPEED_CONFIG:
1448                         // FALLTHROUGH
1449                 case USB_DT_CONFIG:
1450                         value = config_buf (dev,
1451                                         w_value >> 8,
1452                                         w_value & 0xff);
1453                         if (value >= 0)
1454                                 value = min (w_length, (u16) value);
1455                         break;
1456                 case USB_DT_STRING:
1457                         goto unrecognized;
1458
1459                 default:                // all others are errors
1460                         break;
1461                 }
1462                 break;
1463
1464         /* currently one config, two speeds */
1465         case USB_REQ_SET_CONFIGURATION:
1466                 if (ctrl->bRequestType != 0)
1467                         goto unrecognized;
1468                 if (0 == (u8) w_value) {
1469                         value = 0;
1470                         dev->current_config = 0;
1471                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1472                         // user mode expected to disable endpoints
1473                 } else {
1474                         u8      config, power;
1475
1476                         if (gadget_is_dualspeed(gadget)
1477                                         && gadget->speed == USB_SPEED_HIGH) {
1478                                 config = dev->hs_config->bConfigurationValue;
1479                                 power = dev->hs_config->bMaxPower;
1480                         } else {
1481                                 config = dev->config->bConfigurationValue;
1482                                 power = dev->config->bMaxPower;
1483                         }
1484
1485                         if (config == (u8) w_value) {
1486                                 value = 0;
1487                                 dev->current_config = config;
1488                                 usb_gadget_vbus_draw(gadget, 2 * power);
1489                         }
1490                 }
1491
1492                 /* report SET_CONFIGURATION like any other control request,
1493                  * except that usermode may not stall this.  the next
1494                  * request mustn't be allowed start until this finishes:
1495                  * endpoints and threads set up, etc.
1496                  *
1497                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1498                  * has bad/racey automagic that prevents synchronizing here.
1499                  * even kernel mode drivers often miss them.
1500                  */
1501                 if (value == 0) {
1502                         INFO (dev, "configuration #%d\n", dev->current_config);
1503                         usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
1504                         if (dev->usermode_setup) {
1505                                 dev->setup_can_stall = 0;
1506                                 goto delegate;
1507                         }
1508                 }
1509                 break;
1510
1511 #ifndef CONFIG_USB_PXA25X
1512         /* PXA automagically handles this request too */
1513         case USB_REQ_GET_CONFIGURATION:
1514                 if (ctrl->bRequestType != 0x80)
1515                         goto unrecognized;
1516                 *(u8 *)req->buf = dev->current_config;
1517                 value = min (w_length, (u16) 1);
1518                 break;
1519 #endif
1520
1521         default:
1522 unrecognized:
1523                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1524                         dev->usermode_setup ? "delegate" : "fail",
1525                         ctrl->bRequestType, ctrl->bRequest,
1526                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1527
1528                 /* if there's an ep0 reader, don't stall */
1529                 if (dev->usermode_setup) {
1530                         dev->setup_can_stall = 1;
1531 delegate:
1532                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1533                                                 ? 1 : 0;
1534                         dev->setup_wLength = w_length;
1535                         dev->setup_out_ready = 0;
1536                         dev->setup_out_error = 0;
1537                         value = 0;
1538
1539                         /* read DATA stage for OUT right away */
1540                         if (unlikely (!dev->setup_in && w_length)) {
1541                                 value = setup_req (gadget->ep0, dev->req,
1542                                                         w_length);
1543                                 if (value < 0)
1544                                         break;
1545                                 value = usb_ep_queue (gadget->ep0, dev->req,
1546                                                         GFP_ATOMIC);
1547                                 if (value < 0) {
1548                                         clean_req (gadget->ep0, dev->req);
1549                                         break;
1550                                 }
1551
1552                                 /* we can't currently stall these */
1553                                 dev->setup_can_stall = 0;
1554                         }
1555
1556                         /* state changes when reader collects event */
1557                         event = next_event (dev, GADGETFS_SETUP);
1558                         event->u.setup = *ctrl;
1559                         ep0_readable (dev);
1560                         spin_unlock (&dev->lock);
1561                         return 0;
1562                 }
1563         }
1564
1565         /* proceed with data transfer and status phases? */
1566         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1567                 req->length = value;
1568                 req->zero = value < w_length;
1569                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1570                 if (value < 0) {
1571                         DBG (dev, "ep_queue --> %d\n", value);
1572                         req->status = 0;
1573                 }
1574         }
1575
1576         /* device stalls when value < 0 */
1577         spin_unlock (&dev->lock);
1578         return value;
1579 }
1580
1581 static void destroy_ep_files (struct dev_data *dev)
1582 {
1583         DBG (dev, "%s %d\n", __func__, dev->state);
1584
1585         /* dev->state must prevent interference */
1586         spin_lock_irq (&dev->lock);
1587         while (!list_empty(&dev->epfiles)) {
1588                 struct ep_data  *ep;
1589                 struct inode    *parent;
1590                 struct dentry   *dentry;
1591
1592                 /* break link to FS */
1593                 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1594                 list_del_init (&ep->epfiles);
1595                 dentry = ep->dentry;
1596                 ep->dentry = NULL;
1597                 parent = dentry->d_parent->d_inode;
1598
1599                 /* break link to controller */
1600                 if (ep->state == STATE_EP_ENABLED)
1601                         (void) usb_ep_disable (ep->ep);
1602                 ep->state = STATE_EP_UNBOUND;
1603                 usb_ep_free_request (ep->ep, ep->req);
1604                 ep->ep = NULL;
1605                 wake_up (&ep->wait);
1606                 put_ep (ep);
1607
1608                 spin_unlock_irq (&dev->lock);
1609
1610                 /* break link to dcache */
1611                 mutex_lock (&parent->i_mutex);
1612                 d_delete (dentry);
1613                 dput (dentry);
1614                 mutex_unlock (&parent->i_mutex);
1615
1616                 spin_lock_irq (&dev->lock);
1617         }
1618         spin_unlock_irq (&dev->lock);
1619 }
1620
1621
1622 static struct dentry *
1623 gadgetfs_create_file (struct super_block *sb, char const *name,
1624                 void *data, const struct file_operations *fops);
1625
1626 static int activate_ep_files (struct dev_data *dev)
1627 {
1628         struct usb_ep   *ep;
1629         struct ep_data  *data;
1630
1631         gadget_for_each_ep (ep, dev->gadget) {
1632
1633                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1634                 if (!data)
1635                         goto enomem0;
1636                 data->state = STATE_EP_DISABLED;
1637                 mutex_init(&data->lock);
1638                 init_waitqueue_head (&data->wait);
1639
1640                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1641                 atomic_set (&data->count, 1);
1642                 data->dev = dev;
1643                 get_dev (dev);
1644
1645                 data->ep = ep;
1646                 ep->driver_data = data;
1647
1648                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1649                 if (!data->req)
1650                         goto enomem1;
1651
1652                 data->dentry = gadgetfs_create_file (dev->sb, data->name,
1653                                 data, &ep_config_operations);
1654                 if (!data->dentry)
1655                         goto enomem2;
1656                 list_add_tail (&data->epfiles, &dev->epfiles);
1657         }
1658         return 0;
1659
1660 enomem2:
1661         usb_ep_free_request (ep, data->req);
1662 enomem1:
1663         put_dev (dev);
1664         kfree (data);
1665 enomem0:
1666         DBG (dev, "%s enomem\n", __func__);
1667         destroy_ep_files (dev);
1668         return -ENOMEM;
1669 }
1670
1671 static void
1672 gadgetfs_unbind (struct usb_gadget *gadget)
1673 {
1674         struct dev_data         *dev = get_gadget_data (gadget);
1675
1676         DBG (dev, "%s\n", __func__);
1677
1678         spin_lock_irq (&dev->lock);
1679         dev->state = STATE_DEV_UNBOUND;
1680         spin_unlock_irq (&dev->lock);
1681
1682         destroy_ep_files (dev);
1683         gadget->ep0->driver_data = NULL;
1684         set_gadget_data (gadget, NULL);
1685
1686         /* we've already been disconnected ... no i/o is active */
1687         if (dev->req)
1688                 usb_ep_free_request (gadget->ep0, dev->req);
1689         DBG (dev, "%s done\n", __func__);
1690         put_dev (dev);
1691 }
1692
1693 static struct dev_data          *the_device;
1694
1695 static int gadgetfs_bind(struct usb_gadget *gadget,
1696                 struct usb_gadget_driver *driver)
1697 {
1698         struct dev_data         *dev = the_device;
1699
1700         if (!dev)
1701                 return -ESRCH;
1702         if (0 != strcmp (CHIP, gadget->name)) {
1703                 pr_err("%s expected %s controller not %s\n",
1704                         shortname, CHIP, gadget->name);
1705                 return -ENODEV;
1706         }
1707
1708         set_gadget_data (gadget, dev);
1709         dev->gadget = gadget;
1710         gadget->ep0->driver_data = dev;
1711
1712         /* preallocate control response and buffer */
1713         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1714         if (!dev->req)
1715                 goto enomem;
1716         dev->req->context = NULL;
1717         dev->req->complete = epio_complete;
1718
1719         if (activate_ep_files (dev) < 0)
1720                 goto enomem;
1721
1722         INFO (dev, "bound to %s driver\n", gadget->name);
1723         spin_lock_irq(&dev->lock);
1724         dev->state = STATE_DEV_UNCONNECTED;
1725         spin_unlock_irq(&dev->lock);
1726         get_dev (dev);
1727         return 0;
1728
1729 enomem:
1730         gadgetfs_unbind (gadget);
1731         return -ENOMEM;
1732 }
1733
1734 static void
1735 gadgetfs_disconnect (struct usb_gadget *gadget)
1736 {
1737         struct dev_data         *dev = get_gadget_data (gadget);
1738         unsigned long           flags;
1739
1740         spin_lock_irqsave (&dev->lock, flags);
1741         if (dev->state == STATE_DEV_UNCONNECTED)
1742                 goto exit;
1743         dev->state = STATE_DEV_UNCONNECTED;
1744
1745         INFO (dev, "disconnected\n");
1746         next_event (dev, GADGETFS_DISCONNECT);
1747         ep0_readable (dev);
1748 exit:
1749         spin_unlock_irqrestore (&dev->lock, flags);
1750 }
1751
1752 static void
1753 gadgetfs_suspend (struct usb_gadget *gadget)
1754 {
1755         struct dev_data         *dev = get_gadget_data (gadget);
1756
1757         INFO (dev, "suspended from state %d\n", dev->state);
1758         spin_lock (&dev->lock);
1759         switch (dev->state) {
1760         case STATE_DEV_SETUP:           // VERY odd... host died??
1761         case STATE_DEV_CONNECTED:
1762         case STATE_DEV_UNCONNECTED:
1763                 next_event (dev, GADGETFS_SUSPEND);
1764                 ep0_readable (dev);
1765                 /* FALLTHROUGH */
1766         default:
1767                 break;
1768         }
1769         spin_unlock (&dev->lock);
1770 }
1771
1772 static struct usb_gadget_driver gadgetfs_driver = {
1773         .function       = (char *) driver_desc,
1774         .bind           = gadgetfs_bind,
1775         .unbind         = gadgetfs_unbind,
1776         .setup          = gadgetfs_setup,
1777         .reset          = gadgetfs_disconnect,
1778         .disconnect     = gadgetfs_disconnect,
1779         .suspend        = gadgetfs_suspend,
1780
1781         .driver = {
1782                 .name           = (char *) shortname,
1783         },
1784 };
1785
1786 /*----------------------------------------------------------------------*/
1787
1788 static void gadgetfs_nop(struct usb_gadget *arg) { }
1789
1790 static int gadgetfs_probe(struct usb_gadget *gadget,
1791                 struct usb_gadget_driver *driver)
1792 {
1793         CHIP = gadget->name;
1794         return -EISNAM;
1795 }
1796
1797 static struct usb_gadget_driver probe_driver = {
1798         .max_speed      = USB_SPEED_HIGH,
1799         .bind           = gadgetfs_probe,
1800         .unbind         = gadgetfs_nop,
1801         .setup          = (void *)gadgetfs_nop,
1802         .disconnect     = gadgetfs_nop,
1803         .driver = {
1804                 .name           = "nop",
1805         },
1806 };
1807
1808
1809 /* DEVICE INITIALIZATION
1810  *
1811  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1812  *     status = write (fd, descriptors, sizeof descriptors)
1813  *
1814  * That write establishes the device configuration, so the kernel can
1815  * bind to the controller ... guaranteeing it can handle enumeration
1816  * at all necessary speeds.  Descriptor order is:
1817  *
1818  * . message tag (u32, host order) ... for now, must be zero; it
1819  *      would change to support features like multi-config devices
1820  * . full/low speed config ... all wTotalLength bytes (with interface,
1821  *      class, altsetting, endpoint, and other descriptors)
1822  * . high speed config ... all descriptors, for high speed operation;
1823  *      this one's optional except for high-speed hardware
1824  * . device descriptor
1825  *
1826  * Endpoints are not yet enabled. Drivers must wait until device
1827  * configuration and interface altsetting changes create
1828  * the need to configure (or unconfigure) them.
1829  *
1830  * After initialization, the device stays active for as long as that
1831  * $CHIP file is open.  Events must then be read from that descriptor,
1832  * such as configuration notifications.
1833  */
1834
1835 static int is_valid_config (struct usb_config_descriptor *config)
1836 {
1837         return config->bDescriptorType == USB_DT_CONFIG
1838                 && config->bLength == USB_DT_CONFIG_SIZE
1839                 && config->bConfigurationValue != 0
1840                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1841                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1842         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1843         /* FIXME check lengths: walk to end */
1844 }
1845
1846 static ssize_t
1847 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1848 {
1849         struct dev_data         *dev = fd->private_data;
1850         ssize_t                 value = len, length = len;
1851         unsigned                total;
1852         u32                     tag;
1853         char                    *kbuf;
1854
1855         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1856                 return -EINVAL;
1857
1858         /* we might need to change message format someday */
1859         if (copy_from_user (&tag, buf, 4))
1860                 return -EFAULT;
1861         if (tag != 0)
1862                 return -EINVAL;
1863         buf += 4;
1864         length -= 4;
1865
1866         kbuf = memdup_user(buf, length);
1867         if (IS_ERR(kbuf))
1868                 return PTR_ERR(kbuf);
1869
1870         spin_lock_irq (&dev->lock);
1871         value = -EINVAL;
1872         if (dev->buf)
1873                 goto fail;
1874         dev->buf = kbuf;
1875
1876         /* full or low speed config */
1877         dev->config = (void *) kbuf;
1878         total = le16_to_cpu(dev->config->wTotalLength);
1879         if (!is_valid_config (dev->config) || total >= length)
1880                 goto fail;
1881         kbuf += total;
1882         length -= total;
1883
1884         /* optional high speed config */
1885         if (kbuf [1] == USB_DT_CONFIG) {
1886                 dev->hs_config = (void *) kbuf;
1887                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1888                 if (!is_valid_config (dev->hs_config) || total >= length)
1889                         goto fail;
1890                 kbuf += total;
1891                 length -= total;
1892         }
1893
1894         /* could support multiple configs, using another encoding! */
1895
1896         /* device descriptor (tweaked for paranoia) */
1897         if (length != USB_DT_DEVICE_SIZE)
1898                 goto fail;
1899         dev->dev = (void *)kbuf;
1900         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1901                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1902                         || dev->dev->bNumConfigurations != 1)
1903                 goto fail;
1904         dev->dev->bNumConfigurations = 1;
1905         dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1906
1907         /* triggers gadgetfs_bind(); then we can enumerate. */
1908         spin_unlock_irq (&dev->lock);
1909         if (dev->hs_config)
1910                 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1911         else
1912                 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1913
1914         value = usb_gadget_probe_driver(&gadgetfs_driver);
1915         if (value != 0) {
1916                 kfree (dev->buf);
1917                 dev->buf = NULL;
1918         } else {
1919                 /* at this point "good" hardware has for the first time
1920                  * let the USB the host see us.  alternatively, if users
1921                  * unplug/replug that will clear all the error state.
1922                  *
1923                  * note:  everything running before here was guaranteed
1924                  * to choke driver model style diagnostics.  from here
1925                  * on, they can work ... except in cleanup paths that
1926                  * kick in after the ep0 descriptor is closed.
1927                  */
1928                 fd->f_op = &ep0_io_operations;
1929                 value = len;
1930         }
1931         return value;
1932
1933 fail:
1934         spin_unlock_irq (&dev->lock);
1935         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1936         kfree (dev->buf);
1937         dev->buf = NULL;
1938         return value;
1939 }
1940
1941 static int
1942 dev_open (struct inode *inode, struct file *fd)
1943 {
1944         struct dev_data         *dev = inode->i_private;
1945         int                     value = -EBUSY;
1946
1947         spin_lock_irq(&dev->lock);
1948         if (dev->state == STATE_DEV_DISABLED) {
1949                 dev->ev_next = 0;
1950                 dev->state = STATE_DEV_OPENED;
1951                 fd->private_data = dev;
1952                 get_dev (dev);
1953                 value = 0;
1954         }
1955         spin_unlock_irq(&dev->lock);
1956         return value;
1957 }
1958
1959 static const struct file_operations dev_init_operations = {
1960         .llseek =       no_llseek,
1961
1962         .open =         dev_open,
1963         .write =        dev_config,
1964         .fasync =       ep0_fasync,
1965         .unlocked_ioctl = dev_ioctl,
1966         .release =      dev_release,
1967 };
1968
1969 /*----------------------------------------------------------------------*/
1970
1971 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1972  *
1973  * Mounting the filesystem creates a controller file, used first for
1974  * device configuration then later for event monitoring.
1975  */
1976
1977
1978 /* FIXME PAM etc could set this security policy without mount options
1979  * if epfiles inherited ownership and permissons from ep0 ...
1980  */
1981
1982 static unsigned default_uid;
1983 static unsigned default_gid;
1984 static unsigned default_perm = S_IRUSR | S_IWUSR;
1985
1986 module_param (default_uid, uint, 0644);
1987 module_param (default_gid, uint, 0644);
1988 module_param (default_perm, uint, 0644);
1989
1990
1991 static struct inode *
1992 gadgetfs_make_inode (struct super_block *sb,
1993                 void *data, const struct file_operations *fops,
1994                 int mode)
1995 {
1996         struct inode *inode = new_inode (sb);
1997
1998         if (inode) {
1999                 inode->i_ino = get_next_ino();
2000                 inode->i_mode = mode;
2001                 inode->i_uid = make_kuid(&init_user_ns, default_uid);
2002                 inode->i_gid = make_kgid(&init_user_ns, default_gid);
2003                 inode->i_atime = inode->i_mtime = inode->i_ctime
2004                                 = CURRENT_TIME;
2005                 inode->i_private = data;
2006                 inode->i_fop = fops;
2007         }
2008         return inode;
2009 }
2010
2011 /* creates in fs root directory, so non-renamable and non-linkable.
2012  * so inode and dentry are paired, until device reconfig.
2013  */
2014 static struct dentry *
2015 gadgetfs_create_file (struct super_block *sb, char const *name,
2016                 void *data, const struct file_operations *fops)
2017 {
2018         struct dentry   *dentry;
2019         struct inode    *inode;
2020
2021         dentry = d_alloc_name(sb->s_root, name);
2022         if (!dentry)
2023                 return NULL;
2024
2025         inode = gadgetfs_make_inode (sb, data, fops,
2026                         S_IFREG | (default_perm & S_IRWXUGO));
2027         if (!inode) {
2028                 dput(dentry);
2029                 return NULL;
2030         }
2031         d_add (dentry, inode);
2032         return dentry;
2033 }
2034
2035 static const struct super_operations gadget_fs_operations = {
2036         .statfs =       simple_statfs,
2037         .drop_inode =   generic_delete_inode,
2038 };
2039
2040 static int
2041 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2042 {
2043         struct inode    *inode;
2044         struct dev_data *dev;
2045
2046         if (the_device)
2047                 return -ESRCH;
2048
2049         /* fake probe to determine $CHIP */
2050         CHIP = NULL;
2051         usb_gadget_probe_driver(&probe_driver);
2052         if (!CHIP)
2053                 return -ENODEV;
2054
2055         /* superblock */
2056         sb->s_blocksize = PAGE_CACHE_SIZE;
2057         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2058         sb->s_magic = GADGETFS_MAGIC;
2059         sb->s_op = &gadget_fs_operations;
2060         sb->s_time_gran = 1;
2061
2062         /* root inode */
2063         inode = gadgetfs_make_inode (sb,
2064                         NULL, &simple_dir_operations,
2065                         S_IFDIR | S_IRUGO | S_IXUGO);
2066         if (!inode)
2067                 goto Enomem;
2068         inode->i_op = &simple_dir_inode_operations;
2069         if (!(sb->s_root = d_make_root (inode)))
2070                 goto Enomem;
2071
2072         /* the ep0 file is named after the controller we expect;
2073          * user mode code can use it for sanity checks, like we do.
2074          */
2075         dev = dev_new ();
2076         if (!dev)
2077                 goto Enomem;
2078
2079         dev->sb = sb;
2080         dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &dev_init_operations);
2081         if (!dev->dentry) {
2082                 put_dev(dev);
2083                 goto Enomem;
2084         }
2085
2086         /* other endpoint files are available after hardware setup,
2087          * from binding to a controller.
2088          */
2089         the_device = dev;
2090         return 0;
2091
2092 Enomem:
2093         return -ENOMEM;
2094 }
2095
2096 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2097 static struct dentry *
2098 gadgetfs_mount (struct file_system_type *t, int flags,
2099                 const char *path, void *opts)
2100 {
2101         return mount_single (t, flags, opts, gadgetfs_fill_super);
2102 }
2103
2104 static void
2105 gadgetfs_kill_sb (struct super_block *sb)
2106 {
2107         kill_litter_super (sb);
2108         if (the_device) {
2109                 put_dev (the_device);
2110                 the_device = NULL;
2111         }
2112 }
2113
2114 /*----------------------------------------------------------------------*/
2115
2116 static struct file_system_type gadgetfs_type = {
2117         .owner          = THIS_MODULE,
2118         .name           = shortname,
2119         .mount          = gadgetfs_mount,
2120         .kill_sb        = gadgetfs_kill_sb,
2121 };
2122 MODULE_ALIAS_FS("gadgetfs");
2123
2124 /*----------------------------------------------------------------------*/
2125
2126 static int __init init (void)
2127 {
2128         int status;
2129
2130         status = register_filesystem (&gadgetfs_type);
2131         if (status == 0)
2132                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2133                         shortname, driver_desc);
2134         return status;
2135 }
2136 module_init (init);
2137
2138 static void __exit cleanup (void)
2139 {
2140         pr_debug ("unregister %s\n", shortname);
2141         unregister_filesystem (&gadgetfs_type);
2142 }
2143 module_exit (cleanup);
2144