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 #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         struct inode                    *inode;
 202 };
 203
 204 static inline void get_ep (struct ep_data *data)
 205 {
 206         atomic_inc (&data->count);
 207 }
 208
 209 static void put_ep (struct ep_data *data)
 210 {
 211         if (likely (!atomic_dec_and_test (&data->count)))
 212                 return;
 213         put_dev (data->dev);
 214         /* needs no more cleanup */
 215         BUG_ON (!list_empty (&data->epfiles));
 216         BUG_ON (waitqueue_active (&data->wait));
 217         kfree (data);
 218 }
 219
 220 /*----------------------------------------------------------------------*/
 221
 222 /* most "how to use the hardware" policy choices are in userspace:
 223  * mapping endpoint roles (which the driver needs) to the capabilities
 224  * which the usb controller has.  most of those capabilities are exposed
 225  * implicitly, starting with the driver name and then endpoint names.
 226  */
 227
 228 static const char *CHIP;
 229
 230 /*----------------------------------------------------------------------*/
 231
 232 /* NOTE:  don't use dev_printk calls before binding to the gadget
 233  * at the end of ep0 configuration, or after unbind.
 234  */
 235
 236 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
 237 #define xprintk(d,level,fmt,args...) \
 238         printk(level "%s: " fmt , shortname , ## args)
 239
 240 #ifdef DEBUG
 241 #define DBG(dev,fmt,args...) \
 242         xprintk(dev , KERN_DEBUG , fmt , ## args)
 243 #else
 244 #define DBG(dev,fmt,args...) \
 245         do { } while (0)
 246 #endif /* DEBUG */
 247
 248 #ifdef VERBOSE_DEBUG
 249 #define VDEBUG  DBG
 250 #else
 251 #define VDEBUG(dev,fmt,args...) \
 252         do { } while (0)
 253 #endif /* DEBUG */
 254
 255 #define ERROR(dev,fmt,args...) \
 256         xprintk(dev , KERN_ERR , fmt , ## args)
 257 #define INFO(dev,fmt,args...) \
 258         xprintk(dev , KERN_INFO , fmt , ## args)
 259
 260
 261 /*----------------------------------------------------------------------*/
 262
 263 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 264  *
 265  * After opening, configure non-control endpoints.  Then use normal
 266  * stream read() and write() requests; and maybe ioctl() to get more
 267  * precise FIFO status when recovering from cancellation.
 268  */
 269
 270 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 271 {
 272         struct ep_data  *epdata = ep->driver_data;
 273
 274         if (!req->context)
 275                 return;
 276         if (req->status)
 277                 epdata->status = req->status;
 278         else
 279                 epdata->status = req->actual;
 280         complete ((struct completion *)req->context);
 281 }
 282
 283 /* tasklock endpoint, returning when it's connected.
 284  * still need dev->lock to use epdata->ep.
 285  */
 286 static int
 287 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
 288 {
 289         int     val;
 290
 291         if (f_flags & O_NONBLOCK) {
 292                 if (!mutex_trylock(&epdata->lock))
 293                         goto nonblock;
 294                 if (epdata->state != STATE_EP_ENABLED) {
 295                         mutex_unlock(&epdata->lock);
 296 nonblock:
 297                         val = -EAGAIN;
 298                 } else
 299                         val = 0;
 300                 return val;
 301         }
 302
 303         val = mutex_lock_interruptible(&epdata->lock);
 304         if (val < 0)
 305                 return val;
 306
 307         switch (epdata->state) {
 308         case STATE_EP_ENABLED:
 309                 break;
 310         // case STATE_EP_DISABLED:              /* "can't happen" */
 311         // case STATE_EP_READY:                 /* "can't happen" */
 312         default:                                /* error! */
 313                 pr_debug ("%s: ep %p not available, state %d\n",
 314                                 shortname, epdata, epdata->state);
 315                 // FALLTHROUGH
 316         case STATE_EP_UNBOUND:                  /* clean disconnect */
 317                 val = -ENODEV;
 318                 mutex_unlock(&epdata->lock);
 319         }
 320         return val;
 321 }
 322
 323 static ssize_t
 324 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 325 {
 326         DECLARE_COMPLETION_ONSTACK (done);
 327         int value;
 328
 329         spin_lock_irq (&epdata->dev->lock);
 330         if (likely (epdata->ep != NULL)) {
 331                 struct usb_request      *req = epdata->req;
 332
 333                 req->context = &done;
 334                 req->complete = epio_complete;
 335                 req->buf = buf;
 336                 req->length = len;
 337                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 338         } else
 339                 value = -ENODEV;
 340         spin_unlock_irq (&epdata->dev->lock);
 341
 342         if (likely (value == 0)) {
 343                 value = wait_event_interruptible (done.wait, done.done);
 344                 if (value != 0) {
 345                         spin_lock_irq (&epdata->dev->lock);
 346                         if (likely (epdata->ep != NULL)) {
 347                                 DBG (epdata->dev, "%s i/o interrupted\n",
 348                                                 epdata->name);
 349                                 usb_ep_dequeue (epdata->ep, epdata->req);
 350                                 spin_unlock_irq (&epdata->dev->lock);
 351
 352                                 wait_event (done.wait, done.done);
 353                                 if (epdata->status == -ECONNRESET)
 354                                         epdata->status = -EINTR;
 355                         } else {
 356                                 spin_unlock_irq (&epdata->dev->lock);
 357
 358                                 DBG (epdata->dev, "endpoint gone\n");
 359                                 epdata->status = -ENODEV;
 360                         }
 361                 }
 362                 return epdata->status;
 363         }
 364         return value;
 365 }
 366
 367
 368 /* handle a synchronous OUT bulk/intr/iso transfer */
 369 static ssize_t
 370 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 371 {
 372         struct ep_data          *data = fd->private_data;
 373         void                    *kbuf;
 374         ssize_t                 value;
 375
 376         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 377                 return value;
 378
 379         /* halt any endpoint by doing a "wrong direction" i/o call */
 380         if (usb_endpoint_dir_in(&data->desc)) {
 381                 if (usb_endpoint_xfer_isoc(&data->desc)) {
 382                         mutex_unlock(&data->lock);
 383                         return -EINVAL;
 384                 }
 385                 DBG (data->dev, "%s halt\n", data->name);
 386                 spin_lock_irq (&data->dev->lock);
 387                 if (likely (data->ep != NULL))
 388                         usb_ep_set_halt (data->ep);
 389                 spin_unlock_irq (&data->dev->lock);
 390                 mutex_unlock(&data->lock);
 391                 return -EBADMSG;
 392         }
 393
 394         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
 395
 396         value = -ENOMEM;
 397         kbuf = kmalloc (len, GFP_KERNEL);
 398         if (unlikely (!kbuf))
 399                 goto free1;
 400
 401         value = ep_io (data, kbuf, len);
 402         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
 403                 data->name, len, (int) value);
 404         if (value >= 0 && copy_to_user (buf, kbuf, value))
 405                 value = -EFAULT;
 406
 407 free1:
 408         mutex_unlock(&data->lock);
 409         kfree (kbuf);
 410         return value;
 411 }
 412
 413 /* handle a synchronous IN bulk/intr/iso transfer */
 414 static ssize_t
 415 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 416 {
 417         struct ep_data          *data = fd->private_data;
 418         void                    *kbuf;
 419         ssize_t                 value;
 420
 421         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 422                 return value;
 423
 424         /* halt any endpoint by doing a "wrong direction" i/o call */
 425         if (!usb_endpoint_dir_in(&data->desc)) {
 426                 if (usb_endpoint_xfer_isoc(&data->desc)) {
 427                         mutex_unlock(&data->lock);
 428                         return -EINVAL;
 429                 }
 430                 DBG (data->dev, "%s halt\n", data->name);
 431                 spin_lock_irq (&data->dev->lock);
 432                 if (likely (data->ep != NULL))
 433                         usb_ep_set_halt (data->ep);
 434                 spin_unlock_irq (&data->dev->lock);
 435                 mutex_unlock(&data->lock);
 436                 return -EBADMSG;
 437         }
 438
 439         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
 440
 441         value = -ENOMEM;
 442         kbuf = kmalloc (len, GFP_KERNEL);
 443         if (!kbuf)
 444                 goto free1;
 445         if (copy_from_user (kbuf, buf, len)) {
 446                 value = -EFAULT;
 447                 goto free1;
 448         }
 449
 450         value = ep_io (data, kbuf, len);
 451         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
 452                 data->name, len, (int) value);
 453 free1:
 454         mutex_unlock(&data->lock);
 455         kfree (kbuf);
 456         return value;
 457 }
 458
 459 static int
 460 ep_release (struct inode *inode, struct file *fd)
 461 {
 462         struct ep_data          *data = fd->private_data;
 463         int value;
 464
 465         value = mutex_lock_interruptible(&data->lock);
 466         if (value < 0)
 467                 return value;
 468
 469         /* clean up if this can be reopened */
 470         if (data->state != STATE_EP_UNBOUND) {
 471                 data->state = STATE_EP_DISABLED;
 472                 data->desc.bDescriptorType = 0;
 473                 data->hs_desc.bDescriptorType = 0;
 474                 usb_ep_disable(data->ep);
 475         }
 476         mutex_unlock(&data->lock);
 477         put_ep (data);
 478         return 0;
 479 }
 480
 481 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
 482 {
 483         struct ep_data          *data = fd->private_data;
 484         int                     status;
 485
 486         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 487                 return status;
 488
 489         spin_lock_irq (&data->dev->lock);
 490         if (likely (data->ep != NULL)) {
 491                 switch (code) {
 492                 case GADGETFS_FIFO_STATUS:
 493                         status = usb_ep_fifo_status (data->ep);
 494                         break;
 495                 case GADGETFS_FIFO_FLUSH:
 496                         usb_ep_fifo_flush (data->ep);
 497                         break;
 498                 case GADGETFS_CLEAR_HALT:
 499                         status = usb_ep_clear_halt (data->ep);
 500                         break;
 501                 default:
 502                         status = -ENOTTY;
 503                 }
 504         } else
 505                 status = -ENODEV;
 506         spin_unlock_irq (&data->dev->lock);
 507         mutex_unlock(&data->lock);
 508         return status;
 509 }
 510
 511 /*----------------------------------------------------------------------*/
 512
 513 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 514
 515 struct kiocb_priv {
 516         struct usb_request      *req;
 517         struct ep_data          *epdata;
 518         struct kiocb            *iocb;
 519         struct mm_struct        *mm;
 520         struct work_struct      work;
 521         void                    *buf;
 522         const struct iovec      *iv;
 523         unsigned long           nr_segs;
 524         unsigned                actual;
 525 };
 526
 527 static int ep_aio_cancel(struct kiocb *iocb)
 528 {
 529         struct kiocb_priv       *priv = iocb->private;
 530         struct ep_data          *epdata;
 531         int                     value;
 532
 533         local_irq_disable();
 534         epdata = priv->epdata;
 535         // spin_lock(&epdata->dev->lock);
 536         if (likely(epdata && epdata->ep && priv->req))
 537                 value = usb_ep_dequeue (epdata->ep, priv->req);
 538         else
 539                 value = -EINVAL;
 540         // spin_unlock(&epdata->dev->lock);
 541         local_irq_enable();
 542
 543         return value;
 544 }
 545
 546 static ssize_t ep_copy_to_user(struct kiocb_priv *priv)
 547 {
 548         ssize_t                 len, total;
 549         void                    *to_copy;
 550         int                     i;
 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
 572         return len;
 573 }
 574
 575 static void ep_user_copy_worker(struct work_struct *work)
 576 {
 577         struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work);
 578         struct mm_struct *mm = priv->mm;
 579         struct kiocb *iocb = priv->iocb;
 580         size_t ret;
 581
 582         use_mm(mm);
 583         ret = ep_copy_to_user(priv);
 584         unuse_mm(mm);
 585
 586         /* completing the iocb can drop the ctx and mm, don't touch mm after */
 587         aio_complete(iocb, ret, ret);
 588
 589         kfree(priv->buf);
 590         kfree(priv);
 591 }
 592
 593 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 594 {
 595         struct kiocb            *iocb = req->context;
 596         struct kiocb_priv       *priv = iocb->private;
 597         struct ep_data          *epdata = priv->epdata;
 598
 599         /* lock against disconnect (and ideally, cancel) */
 600         spin_lock(&epdata->dev->lock);
 601         priv->req = NULL;
 602         priv->epdata = NULL;
 603
 604         /* if this was a write or a read returning no data then we
 605          * don't need to copy anything to userspace, so we can
 606          * complete the aio request immediately.
 607          */
 608         if (priv->iv == NULL || unlikely(req->actual == 0)) {
 609                 kfree(req->buf);
 610                 kfree(priv);
 611                 iocb->private = NULL;
 612                 /* aio_complete() reports bytes-transferred _and_ faults */
 613                 aio_complete(iocb, req->actual ? req->actual : req->status,
 614                                 req->status);
 615         } else {
 616                 /* ep_copy_to_user() won't report both; we hide some faults */
 617                 if (unlikely(0 != req->status))
 618                         DBG(epdata->dev, "%s fault %d len %d\n",
 619                                 ep->name, req->status, req->actual);
 620
 621                 priv->buf = req->buf;
 622                 priv->actual = req->actual;
 623                 schedule_work(&priv->work);
 624         }
 625         spin_unlock(&epdata->dev->lock);
 626
 627         usb_ep_free_request(ep, req);
 628         put_ep(epdata);
 629 }
 630
 631 static ssize_t
 632 ep_aio_rwtail(
 633         struct kiocb    *iocb,
 634         char            *buf,
 635         size_t          len,
 636         struct ep_data  *epdata,
 637         const struct iovec *iv,
 638         unsigned long   nr_segs
 639 )
 640 {
 641         struct kiocb_priv       *priv;
 642         struct usb_request      *req;
 643         ssize_t                 value;
 644
 645         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 646         if (!priv) {
 647                 value = -ENOMEM;
 648 fail:
 649                 kfree(buf);
 650                 return value;
 651         }
 652         iocb->private = priv;
 653         priv->iocb = iocb;
 654         priv->iv = iv;
 655         priv->nr_segs = nr_segs;
 656         INIT_WORK(&priv->work, ep_user_copy_worker);
 657
 658         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 659         if (unlikely(value < 0)) {
 660                 kfree(priv);
 661                 goto fail;
 662         }
 663
 664         kiocb_set_cancel_fn(iocb, ep_aio_cancel);
 665         get_ep(epdata);
 666         priv->epdata = epdata;
 667         priv->actual = 0;
 668         priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */
 669
 670         /* each kiocb is coupled to one usb_request, but we can't
 671          * allocate or submit those if the host disconnected.
 672          */
 673         spin_lock_irq(&epdata->dev->lock);
 674         if (likely(epdata->ep)) {
 675                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 676                 if (likely(req)) {
 677                         priv->req = req;
 678                         req->buf = buf;
 679                         req->length = len;
 680                         req->complete = ep_aio_complete;
 681                         req->context = iocb;
 682                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 683                         if (unlikely(0 != value))
 684                                 usb_ep_free_request(epdata->ep, req);
 685                 } else
 686                         value = -EAGAIN;
 687         } else
 688                 value = -ENODEV;
 689         spin_unlock_irq(&epdata->dev->lock);
 690
 691         mutex_unlock(&epdata->lock);
 692
 693         if (unlikely(value)) {
 694                 kfree(priv);
 695                 put_ep(epdata);
 696         } else
 697                 value = -EIOCBQUEUED;
 698         return value;
 699 }
 700
 701 static ssize_t
 702 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
 703                 unsigned long nr_segs, loff_t o)
 704 {
 705         struct ep_data          *epdata = iocb->ki_filp->private_data;
 706         char                    *buf;
 707
 708         if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
 709                 return -EINVAL;
 710
 711         buf = kmalloc(iocb->ki_nbytes, GFP_KERNEL);
 712         if (unlikely(!buf))
 713                 return -ENOMEM;
 714
 715         return ep_aio_rwtail(iocb, buf, iocb->ki_nbytes, epdata, iov, nr_segs);
 716 }
 717
 718 static ssize_t
 719 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
 720                 unsigned long nr_segs, loff_t o)
 721 {
 722         struct ep_data          *epdata = iocb->ki_filp->private_data;
 723         char                    *buf;
 724         size_t                  len = 0;
 725         int                     i = 0;
 726
 727         if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
 728                 return -EINVAL;
 729
 730         buf = kmalloc(iocb->ki_nbytes, GFP_KERNEL);
 731         if (unlikely(!buf))
 732                 return -ENOMEM;
 733
 734         for (i=0; i < nr_segs; i++) {
 735                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
 736                                 iov[i].iov_len) != 0)) {
 737                         kfree(buf);
 738                         return -EFAULT;
 739                 }
 740                 len += iov[i].iov_len;
 741         }
 742         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
 743 }
 744
 745 /*----------------------------------------------------------------------*/
 746
 747 /* used after endpoint configuration */
 748 static const struct file_operations ep_io_operations = {
 749         .owner =        THIS_MODULE,
 750         .llseek =       no_llseek,
 751
 752         .read =         ep_read,
 753         .write =        ep_write,
 754         .unlocked_ioctl = ep_ioctl,
 755         .release =      ep_release,
 756
 757         .aio_read =     ep_aio_read,
 758         .aio_write =    ep_aio_write,
 759 };
 760
 761 /* ENDPOINT INITIALIZATION
 762  *
 763  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 764  *     status = write (fd, descriptors, sizeof descriptors)
 765  *
 766  * That write establishes the endpoint configuration, configuring
 767  * the controller to process bulk, interrupt, or isochronous transfers
 768  * at the right maxpacket size, and so on.
 769  *
 770  * The descriptors are message type 1, identified by a host order u32
 771  * at the beginning of what's written.  Descriptor order is: full/low
 772  * speed descriptor, then optional high speed descriptor.
 773  */
 774 static ssize_t
 775 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 776 {
 777         struct ep_data          *data = fd->private_data;
 778         struct usb_ep           *ep;
 779         u32                     tag;
 780         int                     value, length = len;
 781
 782         value = mutex_lock_interruptible(&data->lock);
 783         if (value < 0)
 784                 return value;
 785
 786         if (data->state != STATE_EP_READY) {
 787                 value = -EL2HLT;
 788                 goto fail;
 789         }
 790
 791         value = len;
 792         if (len < USB_DT_ENDPOINT_SIZE + 4)
 793                 goto fail0;
 794
 795         /* we might need to change message format someday */
 796         if (copy_from_user (&tag, buf, 4)) {
 797                 goto fail1;
 798         }
 799         if (tag != 1) {
 800                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 801                 goto fail0;
 802         }
 803         buf += 4;
 804         len -= 4;
 805
 806         /* NOTE:  audio endpoint extensions not accepted here;
 807          * just don't include the extra bytes.
 808          */
 809
 810         /* full/low speed descriptor, then high speed */
 811         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 812                 goto fail1;
 813         }
 814         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 815                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 816                 goto fail0;
 817         if (len != USB_DT_ENDPOINT_SIZE) {
 818                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 819                         goto fail0;
 820                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 821                                         USB_DT_ENDPOINT_SIZE)) {
 822                         goto fail1;
 823                 }
 824                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 825                                 || data->hs_desc.bDescriptorType
 826                                         != USB_DT_ENDPOINT) {
 827                         DBG(data->dev, "config %s, bad hs length or type\n",
 828                                         data->name);
 829                         goto fail0;
 830                 }
 831         }
 832
 833         spin_lock_irq (&data->dev->lock);
 834         if (data->dev->state == STATE_DEV_UNBOUND) {
 835                 value = -ENOENT;
 836                 goto gone;
 837         } else if ((ep = data->ep) == NULL) {
 838                 value = -ENODEV;
 839                 goto gone;
 840         }
 841         switch (data->dev->gadget->speed) {
 842         case USB_SPEED_LOW:
 843         case USB_SPEED_FULL:
 844                 ep->desc = &data->desc;
 845                 value = usb_ep_enable(ep);
 846                 if (value == 0)
 847                         data->state = STATE_EP_ENABLED;
 848                 break;
 849         case USB_SPEED_HIGH:
 850                 /* fails if caller didn't provide that descriptor... */
 851                 ep->desc = &data->hs_desc;
 852                 value = usb_ep_enable(ep);
 853                 if (value == 0)
 854                         data->state = STATE_EP_ENABLED;
 855                 break;
 856         default:
 857                 DBG(data->dev, "unconnected, %s init abandoned\n",
 858                                 data->name);
 859                 value = -EINVAL;
 860         }
 861         if (value == 0) {
 862                 fd->f_op = &ep_io_operations;
 863                 value = length;
 864         }
 865 gone:
 866         spin_unlock_irq (&data->dev->lock);
 867         if (value < 0) {
 868 fail:
 869                 data->desc.bDescriptorType = 0;
 870                 data->hs_desc.bDescriptorType = 0;
 871         }
 872         mutex_unlock(&data->lock);
 873         return value;
 874 fail0:
 875         value = -EINVAL;
 876         goto fail;
 877 fail1:
 878         value = -EFAULT;
 879         goto fail;
 880 }
 881
 882 static int
 883 ep_open (struct inode *inode, struct file *fd)
 884 {
 885         struct ep_data          *data = inode->i_private;
 886         int                     value = -EBUSY;
 887
 888         if (mutex_lock_interruptible(&data->lock) != 0)
 889                 return -EINTR;
 890         spin_lock_irq (&data->dev->lock);
 891         if (data->dev->state == STATE_DEV_UNBOUND)
 892                 value = -ENOENT;
 893         else if (data->state == STATE_EP_DISABLED) {
 894                 value = 0;
 895                 data->state = STATE_EP_READY;
 896                 get_ep (data);
 897                 fd->private_data = data;
 898                 VDEBUG (data->dev, "%s ready\n", data->name);
 899         } else
 900                 DBG (data->dev, "%s state %d\n",
 901                         data->name, data->state);
 902         spin_unlock_irq (&data->dev->lock);
 903         mutex_unlock(&data->lock);
 904         return value;
 905 }
 906
 907 /* used before endpoint configuration */
 908 static const struct file_operations ep_config_operations = {
 909         .llseek =       no_llseek,
 910
 911         .open =         ep_open,
 912         .write =        ep_config,
 913         .release =      ep_release,
 914 };
 915
 916 /*----------------------------------------------------------------------*/
 917
 918 /* EP0 IMPLEMENTATION can be partly in userspace.
 919  *
 920  * Drivers that use this facility receive various events, including
 921  * control requests the kernel doesn't handle.  Drivers that don't
 922  * use this facility may be too simple-minded for real applications.
 923  */
 924
 925 static inline void ep0_readable (struct dev_data *dev)
 926 {
 927         wake_up (&dev->wait);
 928         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 929 }
 930
 931 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 932 {
 933         struct dev_data         *dev = ep->driver_data;
 934
 935         if (req->buf != dev->rbuf) {
 936                 kfree(req->buf);
 937                 req->buf = dev->rbuf;
 938         }
 939         req->complete = epio_complete;
 940         dev->setup_out_ready = 0;
 941 }
 942
 943 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 944 {
 945         struct dev_data         *dev = ep->driver_data;
 946         unsigned long           flags;
 947         int                     free = 1;
 948
 949         /* for control OUT, data must still get to userspace */
 950         spin_lock_irqsave(&dev->lock, flags);
 951         if (!dev->setup_in) {
 952                 dev->setup_out_error = (req->status != 0);
 953                 if (!dev->setup_out_error)
 954                         free = 0;
 955                 dev->setup_out_ready = 1;
 956                 ep0_readable (dev);
 957         }
 958
 959         /* clean up as appropriate */
 960         if (free && req->buf != &dev->rbuf)
 961                 clean_req (ep, req);
 962         req->complete = epio_complete;
 963         spin_unlock_irqrestore(&dev->lock, flags);
 964 }
 965
 966 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 967 {
 968         struct dev_data *dev = ep->driver_data;
 969
 970         if (dev->setup_out_ready) {
 971                 DBG (dev, "ep0 request busy!\n");
 972                 return -EBUSY;
 973         }
 974         if (len > sizeof (dev->rbuf))
 975                 req->buf = kmalloc(len, GFP_ATOMIC);
 976         if (req->buf == NULL) {
 977                 req->buf = dev->rbuf;
 978                 return -ENOMEM;
 979         }
 980         req->complete = ep0_complete;
 981         req->length = len;
 982         req->zero = 0;
 983         return 0;
 984 }
 985
 986 static ssize_t
 987 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 988 {
 989         struct dev_data                 *dev = fd->private_data;
 990         ssize_t                         retval;
 991         enum ep0_state                  state;
 992
 993         spin_lock_irq (&dev->lock);
 994
 995         /* report fd mode change before acting on it */
 996         if (dev->setup_abort) {
 997                 dev->setup_abort = 0;
 998                 retval = -EIDRM;
 999                 goto done;
1000         }
1001
1002         /* control DATA stage */
1003         if ((state = dev->state) == STATE_DEV_SETUP) {
1004
1005                 if (dev->setup_in) {            /* stall IN */
1006                         VDEBUG(dev, "ep0in stall\n");
1007                         (void) usb_ep_set_halt (dev->gadget->ep0);
1008                         retval = -EL2HLT;
1009                         dev->state = STATE_DEV_CONNECTED;
1010
1011                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
1012                         struct usb_ep           *ep = dev->gadget->ep0;
1013                         struct usb_request      *req = dev->req;
1014
1015                         if ((retval = setup_req (ep, req, 0)) == 0)
1016                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1017                         dev->state = STATE_DEV_CONNECTED;
1018
1019                         /* assume that was SET_CONFIGURATION */
1020                         if (dev->current_config) {
1021                                 unsigned power;
1022
1023                                 if (gadget_is_dualspeed(dev->gadget)
1024                                                 && (dev->gadget->speed
1025                                                         == USB_SPEED_HIGH))
1026                                         power = dev->hs_config->bMaxPower;
1027                                 else
1028                                         power = dev->config->bMaxPower;
1029                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1030                         }
1031
1032                 } else {                        /* collect OUT data */
1033                         if ((fd->f_flags & O_NONBLOCK) != 0
1034                                         && !dev->setup_out_ready) {
1035                                 retval = -EAGAIN;
1036                                 goto done;
1037                         }
1038                         spin_unlock_irq (&dev->lock);
1039                         retval = wait_event_interruptible (dev->wait,
1040                                         dev->setup_out_ready != 0);
1041
1042                         /* FIXME state could change from under us */
1043                         spin_lock_irq (&dev->lock);
1044                         if (retval)
1045                                 goto done;
1046
1047                         if (dev->state != STATE_DEV_SETUP) {
1048                                 retval = -ECANCELED;
1049                                 goto done;
1050                         }
1051                         dev->state = STATE_DEV_CONNECTED;
1052
1053                         if (dev->setup_out_error)
1054                                 retval = -EIO;
1055                         else {
1056                                 len = min (len, (size_t)dev->req->actual);
1057 // FIXME don't call this with the spinlock held ...
1058                                 if (copy_to_user (buf, dev->req->buf, len))
1059                                         retval = -EFAULT;
1060                                 else
1061                                         retval = len;
1062                                 clean_req (dev->gadget->ep0, dev->req);
1063                                 /* NOTE userspace can't yet choose to stall */
1064                         }
1065                 }
1066                 goto done;
1067         }
1068
1069         /* else normal: return event data */
1070         if (len < sizeof dev->event [0]) {
1071                 retval = -EINVAL;
1072                 goto done;
1073         }
1074         len -= len % sizeof (struct usb_gadgetfs_event);
1075         dev->usermode_setup = 1;
1076
1077 scan:
1078         /* return queued events right away */
1079         if (dev->ev_next != 0) {
1080                 unsigned                i, n;
1081
1082                 n = len / sizeof (struct usb_gadgetfs_event);
1083                 if (dev->ev_next < n)
1084                         n = dev->ev_next;
1085
1086                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1087                 for (i = 0; i < n; i++) {
1088                         if (dev->event [i].type == GADGETFS_SETUP) {
1089                                 dev->state = STATE_DEV_SETUP;
1090                                 n = i + 1;
1091                                 break;
1092                         }
1093                 }
1094                 spin_unlock_irq (&dev->lock);
1095                 len = n * sizeof (struct usb_gadgetfs_event);
1096                 if (copy_to_user (buf, &dev->event, len))
1097                         retval = -EFAULT;
1098                 else
1099                         retval = len;
1100                 if (len > 0) {
1101                         /* NOTE this doesn't guard against broken drivers;
1102                          * concurrent ep0 readers may lose events.
1103                          */
1104                         spin_lock_irq (&dev->lock);
1105                         if (dev->ev_next > n) {
1106                                 memmove(&dev->event[0], &dev->event[n],
1107                                         sizeof (struct usb_gadgetfs_event)
1108                                                 * (dev->ev_next - n));
1109                         }
1110                         dev->ev_next -= n;
1111                         spin_unlock_irq (&dev->lock);
1112                 }
1113                 return retval;
1114         }
1115         if (fd->f_flags & O_NONBLOCK) {
1116                 retval = -EAGAIN;
1117                 goto done;
1118         }
1119
1120         switch (state) {
1121         default:
1122                 DBG (dev, "fail %s, state %d\n", __func__, state);
1123                 retval = -ESRCH;
1124                 break;
1125         case STATE_DEV_UNCONNECTED:
1126         case STATE_DEV_CONNECTED:
1127                 spin_unlock_irq (&dev->lock);
1128                 DBG (dev, "%s wait\n", __func__);
1129
1130                 /* wait for events */
1131                 retval = wait_event_interruptible (dev->wait,
1132                                 dev->ev_next != 0);
1133                 if (retval < 0)
1134                         return retval;
1135                 spin_lock_irq (&dev->lock);
1136                 goto scan;
1137         }
1138
1139 done:
1140         spin_unlock_irq (&dev->lock);
1141         return retval;
1142 }
1143
1144 static struct usb_gadgetfs_event *
1145 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1146 {
1147         struct usb_gadgetfs_event       *event;
1148         unsigned                        i;
1149
1150         switch (type) {
1151         /* these events purge the queue */
1152         case GADGETFS_DISCONNECT:
1153                 if (dev->state == STATE_DEV_SETUP)
1154                         dev->setup_abort = 1;
1155                 // FALL THROUGH
1156         case GADGETFS_CONNECT:
1157                 dev->ev_next = 0;
1158                 break;
1159         case GADGETFS_SETUP:            /* previous request timed out */
1160         case GADGETFS_SUSPEND:          /* same effect */
1161                 /* these events can't be repeated */
1162                 for (i = 0; i != dev->ev_next; i++) {
1163                         if (dev->event [i].type != type)
1164                                 continue;
1165                         DBG(dev, "discard old event[%d] %d\n", i, type);
1166                         dev->ev_next--;
1167                         if (i == dev->ev_next)
1168                                 break;
1169                         /* indices start at zero, for simplicity */
1170                         memmove (&dev->event [i], &dev->event [i + 1],
1171                                 sizeof (struct usb_gadgetfs_event)
1172                                         * (dev->ev_next - i));
1173                 }
1174                 break;
1175         default:
1176                 BUG ();
1177         }
1178         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1179         event = &dev->event [dev->ev_next++];
1180         BUG_ON (dev->ev_next > N_EVENT);
1181         memset (event, 0, sizeof *event);
1182         event->type = type;
1183         return event;
1184 }
1185
1186 static ssize_t
1187 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1188 {
1189         struct dev_data         *dev = fd->private_data;
1190         ssize_t                 retval = -ESRCH;
1191
1192         spin_lock_irq (&dev->lock);
1193
1194         /* report fd mode change before acting on it */
1195         if (dev->setup_abort) {
1196                 dev->setup_abort = 0;
1197                 retval = -EIDRM;
1198
1199         /* data and/or status stage for control request */
1200         } else if (dev->state == STATE_DEV_SETUP) {
1201
1202                 /* IN DATA+STATUS caller makes len <= wLength */
1203                 if (dev->setup_in) {
1204                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1205                         if (retval == 0) {
1206                                 dev->state = STATE_DEV_CONNECTED;
1207                                 spin_unlock_irq (&dev->lock);
1208                                 if (copy_from_user (dev->req->buf, buf, len))
1209                                         retval = -EFAULT;
1210                                 else {
1211                                         if (len < dev->setup_wLength)
1212                                                 dev->req->zero = 1;
1213                                         retval = usb_ep_queue (
1214                                                 dev->gadget->ep0, dev->req,
1215                                                 GFP_KERNEL);
1216                                 }
1217                                 if (retval < 0) {
1218                                         spin_lock_irq (&dev->lock);
1219                                         clean_req (dev->gadget->ep0, dev->req);
1220                                         spin_unlock_irq (&dev->lock);
1221                                 } else
1222                                         retval = len;
1223
1224                                 return retval;
1225                         }
1226
1227                 /* can stall some OUT transfers */
1228                 } else if (dev->setup_can_stall) {
1229                         VDEBUG(dev, "ep0out stall\n");
1230                         (void) usb_ep_set_halt (dev->gadget->ep0);
1231                         retval = -EL2HLT;
1232                         dev->state = STATE_DEV_CONNECTED;
1233                 } else {
1234                         DBG(dev, "bogus ep0out stall!\n");
1235                 }
1236         } else
1237                 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1238
1239         spin_unlock_irq (&dev->lock);
1240         return retval;
1241 }
1242
1243 static int
1244 ep0_fasync (int f, struct file *fd, int on)
1245 {
1246         struct dev_data         *dev = fd->private_data;
1247         // caller must F_SETOWN before signal delivery happens
1248         VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1249         return fasync_helper (f, fd, on, &dev->fasync);
1250 }
1251
1252 static struct usb_gadget_driver gadgetfs_driver;
1253
1254 static int
1255 dev_release (struct inode *inode, struct file *fd)
1256 {
1257         struct dev_data         *dev = fd->private_data;
1258
1259         /* closing ep0 === shutdown all */
1260
1261         usb_gadget_unregister_driver (&gadgetfs_driver);
1262
1263         /* at this point "good" hardware has disconnected the
1264          * device from USB; the host won't see it any more.
1265          * alternatively, all host requests will time out.
1266          */
1267
1268         kfree (dev->buf);
1269         dev->buf = NULL;
1270         put_dev (dev);
1271
1272         return 0;
1273 }
1274
1275 static unsigned int
1276 ep0_poll (struct file *fd, poll_table *wait)
1277 {
1278        struct dev_data         *dev = fd->private_data;
1279        int                     mask = 0;
1280
1281        poll_wait(fd, &dev->wait, wait);
1282
1283        spin_lock_irq (&dev->lock);
1284
1285        /* report fd mode change before acting on it */
1286        if (dev->setup_abort) {
1287                dev->setup_abort = 0;
1288                mask = POLLHUP;
1289                goto out;
1290        }
1291
1292        if (dev->state == STATE_DEV_SETUP) {
1293                if (dev->setup_in || dev->setup_can_stall)
1294                        mask = POLLOUT;
1295        } else {
1296                if (dev->ev_next != 0)
1297                        mask = POLLIN;
1298        }
1299 out:
1300        spin_unlock_irq(&dev->lock);
1301        return mask;
1302 }
1303
1304 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1305 {
1306         struct dev_data         *dev = fd->private_data;
1307         struct usb_gadget       *gadget = dev->gadget;
1308         long ret = -ENOTTY;
1309
1310         if (gadget->ops->ioctl)
1311                 ret = gadget->ops->ioctl (gadget, code, value);
1312
1313         return ret;
1314 }
1315
1316 /* used after device configuration */
1317 static const struct file_operations ep0_io_operations = {
1318         .owner =        THIS_MODULE,
1319         .llseek =       no_llseek,
1320
1321         .read =         ep0_read,
1322         .write =        ep0_write,
1323         .fasync =       ep0_fasync,
1324         .poll =         ep0_poll,
1325         .unlocked_ioctl =       dev_ioctl,
1326         .release =      dev_release,
1327 };
1328
1329 /*----------------------------------------------------------------------*/
1330
1331 /* The in-kernel gadget driver handles most ep0 issues, in particular
1332  * enumerating the single configuration (as provided from user space).
1333  *
1334  * Unrecognized ep0 requests may be handled in user space.
1335  */
1336
1337 static void make_qualifier (struct dev_data *dev)
1338 {
1339         struct usb_qualifier_descriptor         qual;
1340         struct usb_device_descriptor            *desc;
1341
1342         qual.bLength = sizeof qual;
1343         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1344         qual.bcdUSB = cpu_to_le16 (0x0200);
1345
1346         desc = dev->dev;
1347         qual.bDeviceClass = desc->bDeviceClass;
1348         qual.bDeviceSubClass = desc->bDeviceSubClass;
1349         qual.bDeviceProtocol = desc->bDeviceProtocol;
1350
1351         /* assumes ep0 uses the same value for both speeds ... */
1352         qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1353
1354         qual.bNumConfigurations = 1;
1355         qual.bRESERVED = 0;
1356
1357         memcpy (dev->rbuf, &qual, sizeof qual);
1358 }
1359
1360 static int
1361 config_buf (struct dev_data *dev, u8 type, unsigned index)
1362 {
1363         int             len;
1364         int             hs = 0;
1365
1366         /* only one configuration */
1367         if (index > 0)
1368                 return -EINVAL;
1369
1370         if (gadget_is_dualspeed(dev->gadget)) {
1371                 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1372                 if (type == USB_DT_OTHER_SPEED_CONFIG)
1373                         hs = !hs;
1374         }
1375         if (hs) {
1376                 dev->req->buf = dev->hs_config;
1377                 len = le16_to_cpu(dev->hs_config->wTotalLength);
1378         } else {
1379                 dev->req->buf = dev->config;
1380                 len = le16_to_cpu(dev->config->wTotalLength);
1381         }
1382         ((u8 *)dev->req->buf) [1] = type;
1383         return len;
1384 }
1385
1386 static int
1387 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1388 {
1389         struct dev_data                 *dev = get_gadget_data (gadget);
1390         struct usb_request              *req = dev->req;
1391         int                             value = -EOPNOTSUPP;
1392         struct usb_gadgetfs_event       *event;
1393         u16                             w_value = le16_to_cpu(ctrl->wValue);
1394         u16                             w_length = le16_to_cpu(ctrl->wLength);
1395
1396         spin_lock (&dev->lock);
1397         dev->setup_abort = 0;
1398         if (dev->state == STATE_DEV_UNCONNECTED) {
1399                 if (gadget_is_dualspeed(gadget)
1400                                 && gadget->speed == USB_SPEED_HIGH
1401                                 && dev->hs_config == NULL) {
1402                         spin_unlock(&dev->lock);
1403                         ERROR (dev, "no high speed config??\n");
1404                         return -EINVAL;
1405                 }
1406
1407                 dev->state = STATE_DEV_CONNECTED;
1408
1409                 INFO (dev, "connected\n");
1410                 event = next_event (dev, GADGETFS_CONNECT);
1411                 event->u.speed = gadget->speed;
1412                 ep0_readable (dev);
1413
1414         /* host may have given up waiting for response.  we can miss control
1415          * requests handled lower down (device/endpoint status and features);
1416          * then ep0_{read,write} will report the wrong status. controller
1417          * driver will have aborted pending i/o.
1418          */
1419         } else if (dev->state == STATE_DEV_SETUP)
1420                 dev->setup_abort = 1;
1421
1422         req->buf = dev->rbuf;
1423         req->context = NULL;
1424         value = -EOPNOTSUPP;
1425         switch (ctrl->bRequest) {
1426
1427         case USB_REQ_GET_DESCRIPTOR:
1428                 if (ctrl->bRequestType != USB_DIR_IN)
1429                         goto unrecognized;
1430                 switch (w_value >> 8) {
1431
1432                 case USB_DT_DEVICE:
1433                         value = min (w_length, (u16) sizeof *dev->dev);
1434                         dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1435                         req->buf = dev->dev;
1436                         break;
1437                 case USB_DT_DEVICE_QUALIFIER:
1438                         if (!dev->hs_config)
1439                                 break;
1440                         value = min (w_length, (u16)
1441                                 sizeof (struct usb_qualifier_descriptor));
1442                         make_qualifier (dev);
1443                         break;
1444                 case USB_DT_OTHER_SPEED_CONFIG:
1445                         // FALLTHROUGH
1446                 case USB_DT_CONFIG:
1447                         value = config_buf (dev,
1448                                         w_value >> 8,
1449                                         w_value & 0xff);
1450                         if (value >= 0)
1451                                 value = min (w_length, (u16) value);
1452                         break;
1453                 case USB_DT_STRING:
1454                         goto unrecognized;
1455
1456                 default:                // all others are errors
1457                         break;
1458                 }
1459                 break;
1460
1461         /* currently one config, two speeds */
1462         case USB_REQ_SET_CONFIGURATION:
1463                 if (ctrl->bRequestType != 0)
1464                         goto unrecognized;
1465                 if (0 == (u8) w_value) {
1466                         value = 0;
1467                         dev->current_config = 0;
1468                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1469                         // user mode expected to disable endpoints
1470                 } else {
1471                         u8      config, power;
1472
1473                         if (gadget_is_dualspeed(gadget)
1474                                         && gadget->speed == USB_SPEED_HIGH) {
1475                                 config = dev->hs_config->bConfigurationValue;
1476                                 power = dev->hs_config->bMaxPower;
1477                         } else {
1478                                 config = dev->config->bConfigurationValue;
1479                                 power = dev->config->bMaxPower;
1480                         }
1481
1482                         if (config == (u8) w_value) {
1483                                 value = 0;
1484                                 dev->current_config = config;
1485                                 usb_gadget_vbus_draw(gadget, 2 * power);
1486                         }
1487                 }
1488
1489                 /* report SET_CONFIGURATION like any other control request,
1490                  * except that usermode may not stall this.  the next
1491                  * request mustn't be allowed start until this finishes:
1492                  * endpoints and threads set up, etc.
1493                  *
1494                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1495                  * has bad/racey automagic that prevents synchronizing here.
1496                  * even kernel mode drivers often miss them.
1497                  */
1498                 if (value == 0) {
1499                         INFO (dev, "configuration #%d\n", dev->current_config);
1500                         if (dev->usermode_setup) {
1501                                 dev->setup_can_stall = 0;
1502                                 goto delegate;
1503                         }
1504                 }
1505                 break;
1506
1507 #ifndef CONFIG_USB_GADGET_PXA25X
1508         /* PXA automagically handles this request too */
1509         case USB_REQ_GET_CONFIGURATION:
1510                 if (ctrl->bRequestType != 0x80)
1511                         goto unrecognized;
1512                 *(u8 *)req->buf = dev->current_config;
1513                 value = min (w_length, (u16) 1);
1514                 break;
1515 #endif
1516
1517         default:
1518 unrecognized:
1519                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1520                         dev->usermode_setup ? "delegate" : "fail",
1521                         ctrl->bRequestType, ctrl->bRequest,
1522                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1523
1524                 /* if there's an ep0 reader, don't stall */
1525                 if (dev->usermode_setup) {
1526                         dev->setup_can_stall = 1;
1527 delegate:
1528                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1529                                                 ? 1 : 0;
1530                         dev->setup_wLength = w_length;
1531                         dev->setup_out_ready = 0;
1532                         dev->setup_out_error = 0;
1533                         value = 0;
1534
1535                         /* read DATA stage for OUT right away */
1536                         if (unlikely (!dev->setup_in && w_length)) {
1537                                 value = setup_req (gadget->ep0, dev->req,
1538                                                         w_length);
1539                                 if (value < 0)
1540                                         break;
1541                                 value = usb_ep_queue (gadget->ep0, dev->req,
1542                                                         GFP_ATOMIC);
1543                                 if (value < 0) {
1544                                         clean_req (gadget->ep0, dev->req);
1545                                         break;
1546                                 }
1547
1548                                 /* we can't currently stall these */
1549                                 dev->setup_can_stall = 0;
1550                         }
1551
1552                         /* state changes when reader collects event */
1553                         event = next_event (dev, GADGETFS_SETUP);
1554                         event->u.setup = *ctrl;
1555                         ep0_readable (dev);
1556                         spin_unlock (&dev->lock);
1557                         return 0;
1558                 }
1559         }
1560
1561         /* proceed with data transfer and status phases? */
1562         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1563                 req->length = value;
1564                 req->zero = value < w_length;
1565                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1566                 if (value < 0) {
1567                         DBG (dev, "ep_queue --> %d\n", value);
1568                         req->status = 0;
1569                 }
1570         }
1571
1572         /* device stalls when value < 0 */
1573         spin_unlock (&dev->lock);
1574         return value;
1575 }
1576
1577 static void destroy_ep_files (struct dev_data *dev)
1578 {
1579         DBG (dev, "%s %d\n", __func__, dev->state);
1580
1581         /* dev->state must prevent interference */
1582         spin_lock_irq (&dev->lock);
1583         while (!list_empty(&dev->epfiles)) {
1584                 struct ep_data  *ep;
1585                 struct inode    *parent;
1586                 struct dentry   *dentry;
1587
1588                 /* break link to FS */
1589                 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1590                 list_del_init (&ep->epfiles);
1591                 dentry = ep->dentry;
1592                 ep->dentry = NULL;
1593                 parent = dentry->d_parent->d_inode;
1594
1595                 /* break link to controller */
1596                 if (ep->state == STATE_EP_ENABLED)
1597                         (void) usb_ep_disable (ep->ep);
1598                 ep->state = STATE_EP_UNBOUND;
1599                 usb_ep_free_request (ep->ep, ep->req);
1600                 ep->ep = NULL;
1601                 wake_up (&ep->wait);
1602                 put_ep (ep);
1603
1604                 spin_unlock_irq (&dev->lock);
1605
1606                 /* break link to dcache */
1607                 mutex_lock (&parent->i_mutex);
1608                 d_delete (dentry);
1609                 dput (dentry);
1610                 mutex_unlock (&parent->i_mutex);
1611
1612                 spin_lock_irq (&dev->lock);
1613         }
1614         spin_unlock_irq (&dev->lock);
1615 }
1616
1617
1618 static struct inode *
1619 gadgetfs_create_file (struct super_block *sb, char const *name,
1620                 void *data, const struct file_operations *fops,
1621                 struct dentry **dentry_p);
1622
1623 static int activate_ep_files (struct dev_data *dev)
1624 {
1625         struct usb_ep   *ep;
1626         struct ep_data  *data;
1627
1628         gadget_for_each_ep (ep, dev->gadget) {
1629
1630                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1631                 if (!data)
1632                         goto enomem0;
1633                 data->state = STATE_EP_DISABLED;
1634                 mutex_init(&data->lock);
1635                 init_waitqueue_head (&data->wait);
1636
1637                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1638                 atomic_set (&data->count, 1);
1639                 data->dev = dev;
1640                 get_dev (dev);
1641
1642                 data->ep = ep;
1643                 ep->driver_data = data;
1644
1645                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1646                 if (!data->req)
1647                         goto enomem1;
1648
1649                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1650                                 data, &ep_config_operations,
1651                                 &data->dentry);
1652                 if (!data->inode)
1653                         goto enomem2;
1654                 list_add_tail (&data->epfiles, &dev->epfiles);
1655         }
1656         return 0;
1657
1658 enomem2:
1659         usb_ep_free_request (ep, data->req);
1660 enomem1:
1661         put_dev (dev);
1662         kfree (data);
1663 enomem0:
1664         DBG (dev, "%s enomem\n", __func__);
1665         destroy_ep_files (dev);
1666         return -ENOMEM;
1667 }
1668
1669 static void
1670 gadgetfs_unbind (struct usb_gadget *gadget)
1671 {
1672         struct dev_data         *dev = get_gadget_data (gadget);
1673
1674         DBG (dev, "%s\n", __func__);
1675
1676         spin_lock_irq (&dev->lock);
1677         dev->state = STATE_DEV_UNBOUND;
1678         spin_unlock_irq (&dev->lock);
1679
1680         destroy_ep_files (dev);
1681         gadget->ep0->driver_data = NULL;
1682         set_gadget_data (gadget, NULL);
1683
1684         /* we've already been disconnected ... no i/o is active */
1685         if (dev->req)
1686                 usb_ep_free_request (gadget->ep0, dev->req);
1687         DBG (dev, "%s done\n", __func__);
1688         put_dev (dev);
1689 }
1690
1691 static struct dev_data          *the_device;
1692
1693 static int gadgetfs_bind(struct usb_gadget *gadget,
1694                 struct usb_gadget_driver *driver)
1695 {
1696         struct dev_data         *dev = the_device;
1697
1698         if (!dev)
1699                 return -ESRCH;
1700         if (0 != strcmp (CHIP, gadget->name)) {
1701                 pr_err("%s expected %s controller not %s\n",
1702                         shortname, CHIP, gadget->name);
1703                 return -ENODEV;
1704         }
1705
1706         set_gadget_data (gadget, dev);
1707         dev->gadget = gadget;
1708         gadget->ep0->driver_data = dev;
1709
1710         /* preallocate control response and buffer */
1711         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1712         if (!dev->req)
1713                 goto enomem;
1714         dev->req->context = NULL;
1715         dev->req->complete = epio_complete;
1716
1717         if (activate_ep_files (dev) < 0)
1718                 goto enomem;
1719
1720         INFO (dev, "bound to %s driver\n", gadget->name);
1721         spin_lock_irq(&dev->lock);
1722         dev->state = STATE_DEV_UNCONNECTED;
1723         spin_unlock_irq(&dev->lock);
1724         get_dev (dev);
1725         return 0;
1726
1727 enomem:
1728         gadgetfs_unbind (gadget);
1729         return -ENOMEM;
1730 }
1731
1732 static void
1733 gadgetfs_disconnect (struct usb_gadget *gadget)
1734 {
1735         struct dev_data         *dev = get_gadget_data (gadget);
1736         unsigned long           flags;
1737
1738         spin_lock_irqsave (&dev->lock, flags);
1739         if (dev->state == STATE_DEV_UNCONNECTED)
1740                 goto exit;
1741         dev->state = STATE_DEV_UNCONNECTED;
1742
1743         INFO (dev, "disconnected\n");
1744         next_event (dev, GADGETFS_DISCONNECT);
1745         ep0_readable (dev);
1746 exit:
1747         spin_unlock_irqrestore (&dev->lock, flags);
1748 }
1749
1750 static void
1751 gadgetfs_suspend (struct usb_gadget *gadget)
1752 {
1753         struct dev_data         *dev = get_gadget_data (gadget);
1754
1755         INFO (dev, "suspended from state %d\n", dev->state);
1756         spin_lock (&dev->lock);
1757         switch (dev->state) {
1758         case STATE_DEV_SETUP:           // VERY odd... host died??
1759         case STATE_DEV_CONNECTED:
1760         case STATE_DEV_UNCONNECTED:
1761                 next_event (dev, GADGETFS_SUSPEND);
1762                 ep0_readable (dev);
1763                 /* FALLTHROUGH */
1764         default:
1765                 break;
1766         }
1767         spin_unlock (&dev->lock);
1768 }
1769
1770 static struct usb_gadget_driver gadgetfs_driver = {
1771         .function       = (char *) driver_desc,
1772         .bind           = gadgetfs_bind,
1773         .unbind         = gadgetfs_unbind,
1774         .setup          = gadgetfs_setup,
1775         .disconnect     = gadgetfs_disconnect,
1776         .suspend        = gadgetfs_suspend,
1777
1778         .driver = {
1779                 .name           = (char *) shortname,
1780         },
1781 };
1782
1783 /*----------------------------------------------------------------------*/
1784
1785 static void gadgetfs_nop(struct usb_gadget *arg) { }
1786
1787 static int gadgetfs_probe(struct usb_gadget *gadget,
1788                 struct usb_gadget_driver *driver)
1789 {
1790         CHIP = gadget->name;
1791         return -EISNAM;
1792 }
1793
1794 static struct usb_gadget_driver probe_driver = {
1795         .max_speed      = USB_SPEED_HIGH,
1796         .bind           = gadgetfs_probe,
1797         .unbind         = gadgetfs_nop,
1798         .setup          = (void *)gadgetfs_nop,
1799         .disconnect     = gadgetfs_nop,
1800         .driver = {
1801                 .name           = "nop",
1802         },
1803 };
1804
1805
1806 /* DEVICE INITIALIZATION
1807  *
1808  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1809  *     status = write (fd, descriptors, sizeof descriptors)
1810  *
1811  * That write establishes the device configuration, so the kernel can
1812  * bind to the controller ... guaranteeing it can handle enumeration
1813  * at all necessary speeds.  Descriptor order is:
1814  *
1815  * . message tag (u32, host order) ... for now, must be zero; it
1816  *      would change to support features like multi-config devices
1817  * . full/low speed config ... all wTotalLength bytes (with interface,
1818  *      class, altsetting, endpoint, and other descriptors)
1819  * . high speed config ... all descriptors, for high speed operation;
1820  *      this one's optional except for high-speed hardware
1821  * . device descriptor
1822  *
1823  * Endpoints are not yet enabled. Drivers must wait until device
1824  * configuration and interface altsetting changes create
1825  * the need to configure (or unconfigure) them.
1826  *
1827  * After initialization, the device stays active for as long as that
1828  * $CHIP file is open.  Events must then be read from that descriptor,
1829  * such as configuration notifications.
1830  */
1831
1832 static int is_valid_config (struct usb_config_descriptor *config)
1833 {
1834         return config->bDescriptorType == USB_DT_CONFIG
1835                 && config->bLength == USB_DT_CONFIG_SIZE
1836                 && config->bConfigurationValue != 0
1837                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1838                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1839         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1840         /* FIXME check lengths: walk to end */
1841 }
1842
1843 static ssize_t
1844 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1845 {
1846         struct dev_data         *dev = fd->private_data;
1847         ssize_t                 value = len, length = len;
1848         unsigned                total;
1849         u32                     tag;
1850         char                    *kbuf;
1851
1852         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1853                 return -EINVAL;
1854
1855         /* we might need to change message format someday */
1856         if (copy_from_user (&tag, buf, 4))
1857                 return -EFAULT;
1858         if (tag != 0)
1859                 return -EINVAL;
1860         buf += 4;
1861         length -= 4;
1862
1863         kbuf = memdup_user(buf, length);
1864         if (IS_ERR(kbuf))
1865                 return PTR_ERR(kbuf);
1866
1867         spin_lock_irq (&dev->lock);
1868         value = -EINVAL;
1869         if (dev->buf)
1870                 goto fail;
1871         dev->buf = kbuf;
1872
1873         /* full or low speed config */
1874         dev->config = (void *) kbuf;
1875         total = le16_to_cpu(dev->config->wTotalLength);
1876         if (!is_valid_config (dev->config) || total >= length)
1877                 goto fail;
1878         kbuf += total;
1879         length -= total;
1880
1881         /* optional high speed config */
1882         if (kbuf [1] == USB_DT_CONFIG) {
1883                 dev->hs_config = (void *) kbuf;
1884                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1885                 if (!is_valid_config (dev->hs_config) || total >= length)
1886                         goto fail;
1887                 kbuf += total;
1888                 length -= total;
1889         }
1890
1891         /* could support multiple configs, using another encoding! */
1892
1893         /* device descriptor (tweaked for paranoia) */
1894         if (length != USB_DT_DEVICE_SIZE)
1895                 goto fail;
1896         dev->dev = (void *)kbuf;
1897         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1898                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1899                         || dev->dev->bNumConfigurations != 1)
1900                 goto fail;
1901         dev->dev->bNumConfigurations = 1;
1902         dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1903
1904         /* triggers gadgetfs_bind(); then we can enumerate. */
1905         spin_unlock_irq (&dev->lock);
1906         if (dev->hs_config)
1907                 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1908         else
1909                 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1910
1911         value = usb_gadget_probe_driver(&gadgetfs_driver);
1912         if (value != 0) {
1913                 kfree (dev->buf);
1914                 dev->buf = NULL;
1915         } else {
1916                 /* at this point "good" hardware has for the first time
1917                  * let the USB the host see us.  alternatively, if users
1918                  * unplug/replug that will clear all the error state.
1919                  *
1920                  * note:  everything running before here was guaranteed
1921                  * to choke driver model style diagnostics.  from here
1922                  * on, they can work ... except in cleanup paths that
1923                  * kick in after the ep0 descriptor is closed.
1924                  */
1925                 fd->f_op = &ep0_io_operations;
1926                 value = len;
1927         }
1928         return value;
1929
1930 fail:
1931         spin_unlock_irq (&dev->lock);
1932         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1933         kfree (dev->buf);
1934         dev->buf = NULL;
1935         return value;
1936 }
1937
1938 static int
1939 dev_open (struct inode *inode, struct file *fd)
1940 {
1941         struct dev_data         *dev = inode->i_private;
1942         int                     value = -EBUSY;
1943
1944         spin_lock_irq(&dev->lock);
1945         if (dev->state == STATE_DEV_DISABLED) {
1946                 dev->ev_next = 0;
1947                 dev->state = STATE_DEV_OPENED;
1948                 fd->private_data = dev;
1949                 get_dev (dev);
1950                 value = 0;
1951         }
1952         spin_unlock_irq(&dev->lock);
1953         return value;
1954 }
1955
1956 static const struct file_operations dev_init_operations = {
1957         .llseek =       no_llseek,
1958
1959         .open =         dev_open,
1960         .write =        dev_config,
1961         .fasync =       ep0_fasync,
1962         .unlocked_ioctl = dev_ioctl,
1963         .release =      dev_release,
1964 };
1965
1966 /*----------------------------------------------------------------------*/
1967
1968 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1969  *
1970  * Mounting the filesystem creates a controller file, used first for
1971  * device configuration then later for event monitoring.
1972  */
1973
1974
1975 /* FIXME PAM etc could set this security policy without mount options
1976  * if epfiles inherited ownership and permissons from ep0 ...
1977  */
1978
1979 static unsigned default_uid;
1980 static unsigned default_gid;
1981 static unsigned default_perm = S_IRUSR | S_IWUSR;
1982
1983 module_param (default_uid, uint, 0644);
1984 module_param (default_gid, uint, 0644);
1985 module_param (default_perm, uint, 0644);
1986
1987
1988 static struct inode *
1989 gadgetfs_make_inode (struct super_block *sb,
1990                 void *data, const struct file_operations *fops,
1991                 int mode)
1992 {
1993         struct inode *inode = new_inode (sb);
1994
1995         if (inode) {
1996                 inode->i_ino = get_next_ino();
1997                 inode->i_mode = mode;
1998                 inode->i_uid = make_kuid(&init_user_ns, default_uid);
1999                 inode->i_gid = make_kgid(&init_user_ns, default_gid);
2000                 inode->i_atime = inode->i_mtime = inode->i_ctime
2001                                 = CURRENT_TIME;
2002                 inode->i_private = data;
2003                 inode->i_fop = fops;
2004         }
2005         return inode;
2006 }
2007
2008 /* creates in fs root directory, so non-renamable and non-linkable.
2009  * so inode and dentry are paired, until device reconfig.
2010  */
2011 static struct inode *
2012 gadgetfs_create_file (struct super_block *sb, char const *name,
2013                 void *data, const struct file_operations *fops,
2014                 struct dentry **dentry_p)
2015 {
2016         struct dentry   *dentry;
2017         struct inode    *inode;
2018
2019         dentry = d_alloc_name(sb->s_root, name);
2020         if (!dentry)
2021                 return NULL;
2022
2023         inode = gadgetfs_make_inode (sb, data, fops,
2024                         S_IFREG | (default_perm & S_IRWXUGO));
2025         if (!inode) {
2026                 dput(dentry);
2027                 return NULL;
2028         }
2029         d_add (dentry, inode);
2030         *dentry_p = dentry;
2031         return inode;
2032 }
2033
2034 static const struct super_operations gadget_fs_operations = {
2035         .statfs =       simple_statfs,
2036         .drop_inode =   generic_delete_inode,
2037 };
2038
2039 static int
2040 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2041 {
2042         struct inode    *inode;
2043         struct dev_data *dev;
2044
2045         if (the_device)
2046                 return -ESRCH;
2047
2048         /* fake probe to determine $CHIP */
2049         usb_gadget_probe_driver(&probe_driver);
2050         if (!CHIP)
2051                 return -ENODEV;
2052
2053         /* superblock */
2054         sb->s_blocksize = PAGE_CACHE_SIZE;
2055         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2056         sb->s_magic = GADGETFS_MAGIC;
2057         sb->s_op = &gadget_fs_operations;
2058         sb->s_time_gran = 1;
2059
2060         /* root inode */
2061         inode = gadgetfs_make_inode (sb,
2062                         NULL, &simple_dir_operations,
2063                         S_IFDIR | S_IRUGO | S_IXUGO);
2064         if (!inode)
2065                 goto Enomem;
2066         inode->i_op = &simple_dir_inode_operations;
2067         if (!(sb->s_root = d_make_root (inode)))
2068                 goto Enomem;
2069
2070         /* the ep0 file is named after the controller we expect;
2071          * user mode code can use it for sanity checks, like we do.
2072          */
2073         dev = dev_new ();
2074         if (!dev)
2075                 goto Enomem;
2076
2077         dev->sb = sb;
2078         if (!gadgetfs_create_file (sb, CHIP,
2079                                 dev, &dev_init_operations,
2080                                 &dev->dentry)) {
2081                 put_dev(dev);
2082                 goto Enomem;
2083         }
2084
2085         /* other endpoint files are available after hardware setup,
2086          * from binding to a controller.
2087          */
2088         the_device = dev;
2089         return 0;
2090
2091 Enomem:
2092         return -ENOMEM;
2093 }
2094
2095 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2096 static struct dentry *
2097 gadgetfs_mount (struct file_system_type *t, int flags,
2098                 const char *path, void *opts)
2099 {
2100         return mount_single (t, flags, opts, gadgetfs_fill_super);
2101 }
2102
2103 static void
2104 gadgetfs_kill_sb (struct super_block *sb)
2105 {
2106         kill_litter_super (sb);
2107         if (the_device) {
2108                 put_dev (the_device);
2109                 the_device = NULL;
2110         }
2111 }
2112
2113 /*----------------------------------------------------------------------*/
2114
2115 static struct file_system_type gadgetfs_type = {
2116         .owner          = THIS_MODULE,
2117         .name           = shortname,
2118         .mount          = gadgetfs_mount,
2119         .kill_sb        = gadgetfs_kill_sb,
2120 };
2121 MODULE_ALIAS_FS("gadgetfs");
2122
2123 /*----------------------------------------------------------------------*/
2124
2125 static int __init init (void)
2126 {
2127         int status;
2128
2129         status = register_filesystem (&gadgetfs_type);
2130         if (status == 0)
2131                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2132                         shortname, driver_desc);
2133         return status;
2134 }
2135 module_init (init);
2136
2137 static void __exit cleanup (void)
2138 {
2139         pr_debug ("unregister %s\n", shortname);
2140         unregister_filesystem (&gadgetfs_type);
2141 }
2142 module_exit (cleanup);
2143