drivers/usb/gadget/inode.c

   1 /*
   2  * inode.c -- user mode filesystem api for usb gadget controllers
   3  *
   4  * Copyright (C) 2003-2004 David Brownell
   5  * Copyright (C) 2003 Agilent Technologies
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22
  23 /* #define VERBOSE_DEBUG */
  24
  25 #include <linux/init.h>
  26 #include <linux/module.h>
  27 #include <linux/fs.h>
  28 #include <linux/pagemap.h>
  29 #include <linux/uts.h>
  30 #include <linux/wait.h>
  31 #include <linux/compiler.h>
  32 #include <asm/uaccess.h>
  33 #include <linux/sched.h>
  34 #include <linux/slab.h>
  35 #include <linux/poll.h>
  36 #include <linux/smp_lock.h>
  37
  38 #include <linux/device.h>
  39 #include <linux/moduleparam.h>
  40
  41 #include <linux/usb/gadgetfs.h>
  42 #include <linux/usb/gadget.h>
  43
  44
  45 /*
  46  * The gadgetfs API maps each endpoint to a file descriptor so that you
  47  * can use standard synchronous read/write calls for I/O.  There's some
  48  * O_NONBLOCK and O_ASYNC/FASYNC style i/o support.  Example usermode
  49  * drivers show how this works in practice.  You can also use AIO to
  50  * eliminate I/O gaps between requests, to help when streaming data.
  51  *
  52  * Key parts that must be USB-specific are protocols defining how the
  53  * read/write operations relate to the hardware state machines.  There
  54  * are two types of files.  One type is for the device, implementing ep0.
  55  * The other type is for each IN or OUT endpoint.  In both cases, the
  56  * user mode driver must configure the hardware before using it.
  57  *
  58  * - First, dev_config() is called when /dev/gadget/$CHIP is configured
  59  *   (by writing configuration and device descriptors).  Afterwards it
  60  *   may serve as a source of device events, used to handle all control
  61  *   requests other than basic enumeration.
  62  *
  63  * - Then, after a SET_CONFIGURATION control request, ep_config() is
  64  *   called when each /dev/gadget/ep* file is configured (by writing
  65  *   endpoint descriptors).  Afterwards these files are used to write()
  66  *   IN data or to read() OUT data.  To halt the endpoint, a "wrong
  67  *   direction" request is issued (like reading an IN endpoint).
  68  *
  69  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
  70  * not possible on all hardware.  For example, precise fault handling with
  71  * respect to data left in endpoint fifos after aborted operations; or
  72  * selective clearing of endpoint halts, to implement SET_INTERFACE.
  73  */
  74
  75 #define DRIVER_DESC     "USB Gadget filesystem"
  76 #define DRIVER_VERSION  "24 Aug 2004"
  77
  78 static const char driver_desc [] = DRIVER_DESC;
  79 static const char shortname [] = "gadgetfs";
  80
  81 MODULE_DESCRIPTION (DRIVER_DESC);
  82 MODULE_AUTHOR ("David Brownell");
  83 MODULE_LICENSE ("GPL");
  84
  85
  86 /*----------------------------------------------------------------------*/
  87
  88 #define GADGETFS_MAGIC          0xaee71ee7
  89 #define DMA_ADDR_INVALID        (~(dma_addr_t)0)
  90
  91 /* /dev/gadget/$CHIP represents ep0 and the whole device */
  92 enum ep0_state {
  93         /* DISBLED is the initial state.
  94          */
  95         STATE_DEV_DISABLED = 0,
  96
  97         /* Only one open() of /dev/gadget/$CHIP; only one file tracks
  98          * ep0/device i/o modes and binding to the controller.  Driver
  99          * must always write descriptors to initialize the device, then
 100          * the device becomes UNCONNECTED until enumeration.
 101          */
 102         STATE_DEV_OPENED,
 103
 104         /* From then on, ep0 fd is in either of two basic modes:
 105          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
 106          * - SETUP: read/write will transfer control data and succeed;
 107          *   or if "wrong direction", performs protocol stall
 108          */
 109         STATE_DEV_UNCONNECTED,
 110         STATE_DEV_CONNECTED,
 111         STATE_DEV_SETUP,
 112
 113         /* UNBOUND means the driver closed ep0, so the device won't be
 114          * accessible again (DEV_DISABLED) until all fds are closed.
 115          */
 116         STATE_DEV_UNBOUND,
 117 };
 118
 119 /* enough for the whole queue: most events invalidate others */
 120 #define N_EVENT                 5
 121
 122 struct dev_data {
 123         spinlock_t                      lock;
 124         atomic_t                        count;
 125         enum ep0_state                  state;          /* P: lock */
 126         struct usb_gadgetfs_event       event [N_EVENT];
 127         unsigned                        ev_next;
 128         struct fasync_struct            *fasync;
 129         u8                              current_config;
 130
 131         /* drivers reading ep0 MUST handle control requests (SETUP)
 132          * reported that way; else the host will time out.
 133          */
 134         unsigned                        usermode_setup : 1,
 135                                         setup_in : 1,
 136                                         setup_can_stall : 1,
 137                                         setup_out_ready : 1,
 138                                         setup_out_error : 1,
 139                                         setup_abort : 1;
 140         unsigned                        setup_wLength;
 141
 142         /* the rest is basically write-once */
 143         struct usb_config_descriptor    *config, *hs_config;
 144         struct usb_device_descriptor    *dev;
 145         struct usb_request              *req;
 146         struct usb_gadget               *gadget;
 147         struct list_head                epfiles;
 148         void                            *buf;
 149         wait_queue_head_t               wait;
 150         struct super_block              *sb;
 151         struct dentry                   *dentry;
 152
 153         /* except this scratch i/o buffer for ep0 */
 154         u8                              rbuf [256];
 155 };
 156
 157 static inline void get_dev (struct dev_data *data)
 158 {
 159         atomic_inc (&data->count);
 160 }
 161
 162 static void put_dev (struct dev_data *data)
 163 {
 164         if (likely (!atomic_dec_and_test (&data->count)))
 165                 return;
 166         /* needs no more cleanup */
 167         BUG_ON (waitqueue_active (&data->wait));
 168         kfree (data);
 169 }
 170
 171 static struct dev_data *dev_new (void)
 172 {
 173         struct dev_data         *dev;
 174
 175         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 176         if (!dev)
 177                 return NULL;
 178         dev->state = STATE_DEV_DISABLED;
 179         atomic_set (&dev->count, 1);
 180         spin_lock_init (&dev->lock);
 181         INIT_LIST_HEAD (&dev->epfiles);
 182         init_waitqueue_head (&dev->wait);
 183         return dev;
 184 }
 185
 186 /*----------------------------------------------------------------------*/
 187
 188 /* other /dev/gadget/$ENDPOINT files represent endpoints */
 189 enum ep_state {
 190         STATE_EP_DISABLED = 0,
 191         STATE_EP_READY,
 192         STATE_EP_ENABLED,
 193         STATE_EP_UNBOUND,
 194 };
 195
 196 struct ep_data {
 197         struct mutex                    lock;
 198         enum ep_state                   state;
 199         atomic_t                        count;
 200         struct dev_data                 *dev;
 201         /* must hold dev->lock before accessing ep or req */
 202         struct usb_ep                   *ep;
 203         struct usb_request              *req;
 204         ssize_t                         status;
 205         char                            name [16];
 206         struct usb_endpoint_descriptor  desc, hs_desc;
 207         struct list_head                epfiles;
 208         wait_queue_head_t               wait;
 209         struct dentry                   *dentry;
 210         struct inode                    *inode;
 211 };
 212
 213 static inline void get_ep (struct ep_data *data)
 214 {
 215         atomic_inc (&data->count);
 216 }
 217
 218 static void put_ep (struct ep_data *data)
 219 {
 220         if (likely (!atomic_dec_and_test (&data->count)))
 221                 return;
 222         put_dev (data->dev);
 223         /* needs no more cleanup */
 224         BUG_ON (!list_empty (&data->epfiles));
 225         BUG_ON (waitqueue_active (&data->wait));
 226         kfree (data);
 227 }
 228
 229 /*----------------------------------------------------------------------*/
 230
 231 /* most "how to use the hardware" policy choices are in userspace:
 232  * mapping endpoint roles (which the driver needs) to the capabilities
 233  * which the usb controller has.  most of those capabilities are exposed
 234  * implicitly, starting with the driver name and then endpoint names.
 235  */
 236
 237 static const char *CHIP;
 238
 239 /*----------------------------------------------------------------------*/
 240
 241 /* NOTE:  don't use dev_printk calls before binding to the gadget
 242  * at the end of ep0 configuration, or after unbind.
 243  */
 244
 245 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
 246 #define xprintk(d,level,fmt,args...) \
 247         printk(level "%s: " fmt , shortname , ## args)
 248
 249 #ifdef DEBUG
 250 #define DBG(dev,fmt,args...) \
 251         xprintk(dev , KERN_DEBUG , fmt , ## args)
 252 #else
 253 #define DBG(dev,fmt,args...) \
 254         do { } while (0)
 255 #endif /* DEBUG */
 256
 257 #ifdef VERBOSE_DEBUG
 258 #define VDEBUG  DBG
 259 #else
 260 #define VDEBUG(dev,fmt,args...) \
 261         do { } while (0)
 262 #endif /* DEBUG */
 263
 264 #define ERROR(dev,fmt,args...) \
 265         xprintk(dev , KERN_ERR , fmt , ## args)
 266 #define INFO(dev,fmt,args...) \
 267         xprintk(dev , KERN_INFO , fmt , ## args)
 268
 269
 270 /*----------------------------------------------------------------------*/
 271
 272 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 273  *
 274  * After opening, configure non-control endpoints.  Then use normal
 275  * stream read() and write() requests; and maybe ioctl() to get more
 276  * precise FIFO status when recovering from cancellation.
 277  */
 278
 279 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 280 {
 281         struct ep_data  *epdata = ep->driver_data;
 282
 283         if (!req->context)
 284                 return;
 285         if (req->status)
 286                 epdata->status = req->status;
 287         else
 288                 epdata->status = req->actual;
 289         complete ((struct completion *)req->context);
 290 }
 291
 292 /* tasklock endpoint, returning when it's connected.
 293  * still need dev->lock to use epdata->ep.
 294  */
 295 static int
 296 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
 297 {
 298         int     val;
 299
 300         if (f_flags & O_NONBLOCK) {
 301                 if (!mutex_trylock(&epdata->lock))
 302                         goto nonblock;
 303                 if (epdata->state != STATE_EP_ENABLED) {
 304                         mutex_unlock(&epdata->lock);
 305 nonblock:
 306                         val = -EAGAIN;
 307                 } else
 308                         val = 0;
 309                 return val;
 310         }
 311
 312         val = mutex_lock_interruptible(&epdata->lock);
 313         if (val < 0)
 314                 return val;
 315
 316         switch (epdata->state) {
 317         case STATE_EP_ENABLED:
 318                 break;
 319         // case STATE_EP_DISABLED:              /* "can't happen" */
 320         // case STATE_EP_READY:                 /* "can't happen" */
 321         default:                                /* error! */
 322                 pr_debug ("%s: ep %p not available, state %d\n",
 323                                 shortname, epdata, epdata->state);
 324                 // FALLTHROUGH
 325         case STATE_EP_UNBOUND:                  /* clean disconnect */
 326                 val = -ENODEV;
 327                 mutex_unlock(&epdata->lock);
 328         }
 329         return val;
 330 }
 331
 332 static ssize_t
 333 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 334 {
 335         DECLARE_COMPLETION_ONSTACK (done);
 336         int value;
 337
 338         spin_lock_irq (&epdata->dev->lock);
 339         if (likely (epdata->ep != NULL)) {
 340                 struct usb_request      *req = epdata->req;
 341
 342                 req->context = &done;
 343                 req->complete = epio_complete;
 344                 req->buf = buf;
 345                 req->length = len;
 346                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 347         } else
 348                 value = -ENODEV;
 349         spin_unlock_irq (&epdata->dev->lock);
 350
 351         if (likely (value == 0)) {
 352                 value = wait_event_interruptible (done.wait, done.done);
 353                 if (value != 0) {
 354                         spin_lock_irq (&epdata->dev->lock);
 355                         if (likely (epdata->ep != NULL)) {
 356                                 DBG (epdata->dev, "%s i/o interrupted\n",
 357                                                 epdata->name);
 358                                 usb_ep_dequeue (epdata->ep, epdata->req);
 359                                 spin_unlock_irq (&epdata->dev->lock);
 360
 361                                 wait_event (done.wait, done.done);
 362                                 if (epdata->status == -ECONNRESET)
 363                                         epdata->status = -EINTR;
 364                         } else {
 365                                 spin_unlock_irq (&epdata->dev->lock);
 366
 367                                 DBG (epdata->dev, "endpoint gone\n");
 368                                 epdata->status = -ENODEV;
 369                         }
 370                 }
 371                 return epdata->status;
 372         }
 373         return value;
 374 }
 375
 376
 377 /* handle a synchronous OUT bulk/intr/iso transfer */
 378 static ssize_t
 379 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 380 {
 381         struct ep_data          *data = fd->private_data;
 382         void                    *kbuf;
 383         ssize_t                 value;
 384
 385         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 386                 return value;
 387
 388         /* halt any endpoint by doing a "wrong direction" i/o call */
 389         if (usb_endpoint_dir_in(&data->desc)) {
 390                 if (usb_endpoint_xfer_isoc(&data->desc))
 391                         return -EINVAL;
 392                 DBG (data->dev, "%s halt\n", data->name);
 393                 spin_lock_irq (&data->dev->lock);
 394                 if (likely (data->ep != NULL))
 395                         usb_ep_set_halt (data->ep);
 396                 spin_unlock_irq (&data->dev->lock);
 397                 mutex_unlock(&data->lock);
 398                 return -EBADMSG;
 399         }
 400
 401         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
 402
 403         value = -ENOMEM;
 404         kbuf = kmalloc (len, GFP_KERNEL);
 405         if (unlikely (!kbuf))
 406                 goto free1;
 407
 408         value = ep_io (data, kbuf, len);
 409         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
 410                 data->name, len, (int) value);
 411         if (value >= 0 && copy_to_user (buf, kbuf, value))
 412                 value = -EFAULT;
 413
 414 free1:
 415         mutex_unlock(&data->lock);
 416         kfree (kbuf);
 417         return value;
 418 }
 419
 420 /* handle a synchronous IN bulk/intr/iso transfer */
 421 static ssize_t
 422 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 423 {
 424         struct ep_data          *data = fd->private_data;
 425         void                    *kbuf;
 426         ssize_t                 value;
 427
 428         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 429                 return value;
 430
 431         /* halt any endpoint by doing a "wrong direction" i/o call */
 432         if (!usb_endpoint_dir_in(&data->desc)) {
 433                 if (usb_endpoint_xfer_isoc(&data->desc))
 434                         return -EINVAL;
 435                 DBG (data->dev, "%s halt\n", data->name);
 436                 spin_lock_irq (&data->dev->lock);
 437                 if (likely (data->ep != NULL))
 438                         usb_ep_set_halt (data->ep);
 439                 spin_unlock_irq (&data->dev->lock);
 440                 mutex_unlock(&data->lock);
 441                 return -EBADMSG;
 442         }
 443
 444         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
 445
 446         value = -ENOMEM;
 447         kbuf = kmalloc (len, GFP_KERNEL);
 448         if (!kbuf)
 449                 goto free1;
 450         if (copy_from_user (kbuf, buf, len)) {
 451                 value = -EFAULT;
 452                 goto free1;
 453         }
 454
 455         value = ep_io (data, kbuf, len);
 456         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
 457                 data->name, len, (int) value);
 458 free1:
 459         mutex_unlock(&data->lock);
 460         kfree (kbuf);
 461         return value;
 462 }
 463
 464 static int
 465 ep_release (struct inode *inode, struct file *fd)
 466 {
 467         struct ep_data          *data = fd->private_data;
 468         int value;
 469
 470         value = mutex_lock_interruptible(&data->lock);
 471         if (value < 0)
 472                 return value;
 473
 474         /* clean up if this can be reopened */
 475         if (data->state != STATE_EP_UNBOUND) {
 476                 data->state = STATE_EP_DISABLED;
 477                 data->desc.bDescriptorType = 0;
 478                 data->hs_desc.bDescriptorType = 0;
 479                 usb_ep_disable(data->ep);
 480         }
 481         mutex_unlock(&data->lock);
 482         put_ep (data);
 483         return 0;
 484 }
 485
 486 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
 487 {
 488         struct ep_data          *data = fd->private_data;
 489         int                     status;
 490
 491         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 492                 return status;
 493
 494         spin_lock_irq (&data->dev->lock);
 495         if (likely (data->ep != NULL)) {
 496                 switch (code) {
 497                 case GADGETFS_FIFO_STATUS:
 498                         status = usb_ep_fifo_status (data->ep);
 499                         break;
 500                 case GADGETFS_FIFO_FLUSH:
 501                         usb_ep_fifo_flush (data->ep);
 502                         break;
 503                 case GADGETFS_CLEAR_HALT:
 504                         status = usb_ep_clear_halt (data->ep);
 505                         break;
 506                 default:
 507                         status = -ENOTTY;
 508                 }
 509         } else
 510                 status = -ENODEV;
 511         spin_unlock_irq (&data->dev->lock);
 512         mutex_unlock(&data->lock);
 513         return status;
 514 }
 515
 516 /*----------------------------------------------------------------------*/
 517
 518 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 519
 520 struct kiocb_priv {
 521         struct usb_request      *req;
 522         struct ep_data          *epdata;
 523         void                    *buf;
 524         const struct iovec      *iv;
 525         unsigned long           nr_segs;
 526         unsigned                actual;
 527 };
 528
 529 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
 530 {
 531         struct kiocb_priv       *priv = iocb->private;
 532         struct ep_data          *epdata;
 533         int                     value;
 534
 535         local_irq_disable();
 536         epdata = priv->epdata;
 537         // spin_lock(&epdata->dev->lock);
 538         kiocbSetCancelled(iocb);
 539         if (likely(epdata && epdata->ep && priv->req))
 540                 value = usb_ep_dequeue (epdata->ep, priv->req);
 541         else
 542                 value = -EINVAL;
 543         // spin_unlock(&epdata->dev->lock);
 544         local_irq_enable();
 545
 546         aio_put_req(iocb);
 547         return value;
 548 }
 549
 550 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
 551 {
 552         struct kiocb_priv       *priv = iocb->private;
 553         ssize_t                 len, total;
 554         void                    *to_copy;
 555         int                     i;
 556
 557         /* we "retry" to get the right mm context for this: */
 558
 559         /* copy stuff into user buffers */
 560         total = priv->actual;
 561         len = 0;
 562         to_copy = priv->buf;
 563         for (i=0; i < priv->nr_segs; i++) {
 564                 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
 565
 566                 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
 567                         if (len == 0)
 568                                 len = -EFAULT;
 569                         break;
 570                 }
 571
 572                 total -= this;
 573                 len += this;
 574                 to_copy += this;
 575                 if (total == 0)
 576                         break;
 577         }
 578         kfree(priv->buf);
 579         kfree(priv);
 580         return len;
 581 }
 582
 583 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 584 {
 585         struct kiocb            *iocb = req->context;
 586         struct kiocb_priv       *priv = iocb->private;
 587         struct ep_data          *epdata = priv->epdata;
 588
 589         /* lock against disconnect (and ideally, cancel) */
 590         spin_lock(&epdata->dev->lock);
 591         priv->req = NULL;
 592         priv->epdata = NULL;
 593
 594         /* if this was a write or a read returning no data then we
 595          * don't need to copy anything to userspace, so we can
 596          * complete the aio request immediately.
 597          */
 598         if (priv->iv == NULL || unlikely(req->actual == 0)) {
 599                 kfree(req->buf);
 600                 kfree(priv);
 601                 iocb->private = NULL;
 602                 /* aio_complete() reports bytes-transferred _and_ faults */
 603                 aio_complete(iocb, req->actual ? req->actual : req->status,
 604                                 req->status);
 605         } else {
 606                 /* retry() won't report both; so we hide some faults */
 607                 if (unlikely(0 != req->status))
 608                         DBG(epdata->dev, "%s fault %d len %d\n",
 609                                 ep->name, req->status, req->actual);
 610
 611                 priv->buf = req->buf;
 612                 priv->actual = req->actual;
 613                 kick_iocb(iocb);
 614         }
 615         spin_unlock(&epdata->dev->lock);
 616
 617         usb_ep_free_request(ep, req);
 618         put_ep(epdata);
 619 }
 620
 621 static ssize_t
 622 ep_aio_rwtail(
 623         struct kiocb    *iocb,
 624         char            *buf,
 625         size_t          len,
 626         struct ep_data  *epdata,
 627         const struct iovec *iv,
 628         unsigned long   nr_segs
 629 )
 630 {
 631         struct kiocb_priv       *priv;
 632         struct usb_request      *req;
 633         ssize_t                 value;
 634
 635         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 636         if (!priv) {
 637                 value = -ENOMEM;
 638 fail:
 639                 kfree(buf);
 640                 return value;
 641         }
 642         iocb->private = priv;
 643         priv->iv = iv;
 644         priv->nr_segs = nr_segs;
 645
 646         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 647         if (unlikely(value < 0)) {
 648                 kfree(priv);
 649                 goto fail;
 650         }
 651
 652         iocb->ki_cancel = ep_aio_cancel;
 653         get_ep(epdata);
 654         priv->epdata = epdata;
 655         priv->actual = 0;
 656
 657         /* each kiocb is coupled to one usb_request, but we can't
 658          * allocate or submit those if the host disconnected.
 659          */
 660         spin_lock_irq(&epdata->dev->lock);
 661         if (likely(epdata->ep)) {
 662                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 663                 if (likely(req)) {
 664                         priv->req = req;
 665                         req->buf = buf;
 666                         req->length = len;
 667                         req->complete = ep_aio_complete;
 668                         req->context = iocb;
 669                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 670                         if (unlikely(0 != value))
 671                                 usb_ep_free_request(epdata->ep, req);
 672                 } else
 673                         value = -EAGAIN;
 674         } else
 675                 value = -ENODEV;
 676         spin_unlock_irq(&epdata->dev->lock);
 677
 678         mutex_unlock(&epdata->lock);
 679
 680         if (unlikely(value)) {
 681                 kfree(priv);
 682                 put_ep(epdata);
 683         } else
 684                 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
 685         return value;
 686 }
 687
 688 static ssize_t
 689 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
 690                 unsigned long nr_segs, loff_t o)
 691 {
 692         struct ep_data          *epdata = iocb->ki_filp->private_data;
 693         char                    *buf;
 694
 695         if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
 696                 return -EINVAL;
 697
 698         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 699         if (unlikely(!buf))
 700                 return -ENOMEM;
 701
 702         iocb->ki_retry = ep_aio_read_retry;
 703         return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
 704 }
 705
 706 static ssize_t
 707 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
 708                 unsigned long nr_segs, loff_t o)
 709 {
 710         struct ep_data          *epdata = iocb->ki_filp->private_data;
 711         char                    *buf;
 712         size_t                  len = 0;
 713         int                     i = 0;
 714
 715         if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
 716                 return -EINVAL;
 717
 718         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 719         if (unlikely(!buf))
 720                 return -ENOMEM;
 721
 722         for (i=0; i < nr_segs; i++) {
 723                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
 724                                 iov[i].iov_len) != 0)) {
 725                         kfree(buf);
 726                         return -EFAULT;
 727                 }
 728                 len += iov[i].iov_len;
 729         }
 730         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
 731 }
 732
 733 /*----------------------------------------------------------------------*/
 734
 735 /* used after endpoint configuration */
 736 static const struct file_operations ep_io_operations = {
 737         .owner =        THIS_MODULE,
 738         .llseek =       no_llseek,
 739
 740         .read =         ep_read,
 741         .write =        ep_write,
 742         .unlocked_ioctl = ep_ioctl,
 743         .release =      ep_release,
 744
 745         .aio_read =     ep_aio_read,
 746         .aio_write =    ep_aio_write,
 747 };
 748
 749 /* ENDPOINT INITIALIZATION
 750  *
 751  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 752  *     status = write (fd, descriptors, sizeof descriptors)
 753  *
 754  * That write establishes the endpoint configuration, configuring
 755  * the controller to process bulk, interrupt, or isochronous transfers
 756  * at the right maxpacket size, and so on.
 757  *
 758  * The descriptors are message type 1, identified by a host order u32
 759  * at the beginning of what's written.  Descriptor order is: full/low
 760  * speed descriptor, then optional high speed descriptor.
 761  */
 762 static ssize_t
 763 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 764 {
 765         struct ep_data          *data = fd->private_data;
 766         struct usb_ep           *ep;
 767         u32                     tag;
 768         int                     value, length = len;
 769
 770         value = mutex_lock_interruptible(&data->lock);
 771         if (value < 0)
 772                 return value;
 773
 774         if (data->state != STATE_EP_READY) {
 775                 value = -EL2HLT;
 776                 goto fail;
 777         }
 778
 779         value = len;
 780         if (len < USB_DT_ENDPOINT_SIZE + 4)
 781                 goto fail0;
 782
 783         /* we might need to change message format someday */
 784         if (copy_from_user (&tag, buf, 4)) {
 785                 goto fail1;
 786         }
 787         if (tag != 1) {
 788                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 789                 goto fail0;
 790         }
 791         buf += 4;
 792         len -= 4;
 793
 794         /* NOTE:  audio endpoint extensions not accepted here;
 795          * just don't include the extra bytes.
 796          */
 797
 798         /* full/low speed descriptor, then high speed */
 799         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 800                 goto fail1;
 801         }
 802         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 803                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 804                 goto fail0;
 805         if (len != USB_DT_ENDPOINT_SIZE) {
 806                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 807                         goto fail0;
 808                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 809                                         USB_DT_ENDPOINT_SIZE)) {
 810                         goto fail1;
 811                 }
 812                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 813                                 || data->hs_desc.bDescriptorType
 814                                         != USB_DT_ENDPOINT) {
 815                         DBG(data->dev, "config %s, bad hs length or type\n",
 816                                         data->name);
 817                         goto fail0;
 818                 }
 819         }
 820
 821         spin_lock_irq (&data->dev->lock);
 822         if (data->dev->state == STATE_DEV_UNBOUND) {
 823                 value = -ENOENT;
 824                 goto gone;
 825         } else if ((ep = data->ep) == NULL) {
 826                 value = -ENODEV;
 827                 goto gone;
 828         }
 829         switch (data->dev->gadget->speed) {
 830         case USB_SPEED_LOW:
 831         case USB_SPEED_FULL:
 832                 value = usb_ep_enable (ep, &data->desc);
 833                 if (value == 0)
 834                         data->state = STATE_EP_ENABLED;
 835                 break;
 836 #ifdef  CONFIG_USB_GADGET_DUALSPEED
 837         case USB_SPEED_HIGH:
 838                 /* fails if caller didn't provide that descriptor... */
 839                 value = usb_ep_enable (ep, &data->hs_desc);
 840                 if (value == 0)
 841                         data->state = STATE_EP_ENABLED;
 842                 break;
 843 #endif
 844         default:
 845                 DBG(data->dev, "unconnected, %s init abandoned\n",
 846                                 data->name);
 847                 value = -EINVAL;
 848         }
 849         if (value == 0) {
 850                 fd->f_op = &ep_io_operations;
 851                 value = length;
 852         }
 853 gone:
 854         spin_unlock_irq (&data->dev->lock);
 855         if (value < 0) {
 856 fail:
 857                 data->desc.bDescriptorType = 0;
 858                 data->hs_desc.bDescriptorType = 0;
 859         }
 860         mutex_unlock(&data->lock);
 861         return value;
 862 fail0:
 863         value = -EINVAL;
 864         goto fail;
 865 fail1:
 866         value = -EFAULT;
 867         goto fail;
 868 }
 869
 870 static int
 871 ep_open (struct inode *inode, struct file *fd)
 872 {
 873         struct ep_data          *data = inode->i_private;
 874         int                     value = -EBUSY;
 875
 876         if (mutex_lock_interruptible(&data->lock) != 0)
 877                 return -EINTR;
 878         spin_lock_irq (&data->dev->lock);
 879         if (data->dev->state == STATE_DEV_UNBOUND)
 880                 value = -ENOENT;
 881         else if (data->state == STATE_EP_DISABLED) {
 882                 value = 0;
 883                 data->state = STATE_EP_READY;
 884                 get_ep (data);
 885                 fd->private_data = data;
 886                 VDEBUG (data->dev, "%s ready\n", data->name);
 887         } else
 888                 DBG (data->dev, "%s state %d\n",
 889                         data->name, data->state);
 890         spin_unlock_irq (&data->dev->lock);
 891         mutex_unlock(&data->lock);
 892         return value;
 893 }
 894
 895 /* used before endpoint configuration */
 896 static const struct file_operations ep_config_operations = {
 897         .owner =        THIS_MODULE,
 898         .llseek =       no_llseek,
 899
 900         .open =         ep_open,
 901         .write =        ep_config,
 902         .release =      ep_release,
 903 };
 904
 905 /*----------------------------------------------------------------------*/
 906
 907 /* EP0 IMPLEMENTATION can be partly in userspace.
 908  *
 909  * Drivers that use this facility receive various events, including
 910  * control requests the kernel doesn't handle.  Drivers that don't
 911  * use this facility may be too simple-minded for real applications.
 912  */
 913
 914 static inline void ep0_readable (struct dev_data *dev)
 915 {
 916         wake_up (&dev->wait);
 917         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 918 }
 919
 920 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 921 {
 922         struct dev_data         *dev = ep->driver_data;
 923
 924         if (req->buf != dev->rbuf) {
 925                 kfree(req->buf);
 926                 req->buf = dev->rbuf;
 927                 req->dma = DMA_ADDR_INVALID;
 928         }
 929         req->complete = epio_complete;
 930         dev->setup_out_ready = 0;
 931 }
 932
 933 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 934 {
 935         struct dev_data         *dev = ep->driver_data;
 936         unsigned long           flags;
 937         int                     free = 1;
 938
 939         /* for control OUT, data must still get to userspace */
 940         spin_lock_irqsave(&dev->lock, flags);
 941         if (!dev->setup_in) {
 942                 dev->setup_out_error = (req->status != 0);
 943                 if (!dev->setup_out_error)
 944                         free = 0;
 945                 dev->setup_out_ready = 1;
 946                 ep0_readable (dev);
 947         }
 948
 949         /* clean up as appropriate */
 950         if (free && req->buf != &dev->rbuf)
 951                 clean_req (ep, req);
 952         req->complete = epio_complete;
 953         spin_unlock_irqrestore(&dev->lock, flags);
 954 }
 955
 956 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 957 {
 958         struct dev_data *dev = ep->driver_data;
 959
 960         if (dev->setup_out_ready) {
 961                 DBG (dev, "ep0 request busy!\n");
 962                 return -EBUSY;
 963         }
 964         if (len > sizeof (dev->rbuf))
 965                 req->buf = kmalloc(len, GFP_ATOMIC);
 966         if (req->buf == NULL) {
 967                 req->buf = dev->rbuf;
 968                 return -ENOMEM;
 969         }
 970         req->complete = ep0_complete;
 971         req->length = len;
 972         req->zero = 0;
 973         return 0;
 974 }
 975
 976 static ssize_t
 977 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 978 {
 979         struct dev_data                 *dev = fd->private_data;
 980         ssize_t                         retval;
 981         enum ep0_state                  state;
 982
 983         spin_lock_irq (&dev->lock);
 984
 985         /* report fd mode change before acting on it */
 986         if (dev->setup_abort) {
 987                 dev->setup_abort = 0;
 988                 retval = -EIDRM;
 989                 goto done;
 990         }
 991
 992         /* control DATA stage */
 993         if ((state = dev->state) == STATE_DEV_SETUP) {
 994
 995                 if (dev->setup_in) {            /* stall IN */
 996                         VDEBUG(dev, "ep0in stall\n");
 997                         (void) usb_ep_set_halt (dev->gadget->ep0);
 998                         retval = -EL2HLT;
 999                         dev->state = STATE_DEV_CONNECTED;
1000
1001                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
1002                         struct usb_ep           *ep = dev->gadget->ep0;
1003                         struct usb_request      *req = dev->req;
1004
1005                         if ((retval = setup_req (ep, req, 0)) == 0)
1006                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1007                         dev->state = STATE_DEV_CONNECTED;
1008
1009                         /* assume that was SET_CONFIGURATION */
1010                         if (dev->current_config) {
1011                                 unsigned power;
1012
1013                                 if (gadget_is_dualspeed(dev->gadget)
1014                                                 && (dev->gadget->speed
1015                                                         == USB_SPEED_HIGH))
1016                                         power = dev->hs_config->bMaxPower;
1017                                 else
1018                                         power = dev->config->bMaxPower;
1019                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1020                         }
1021
1022                 } else {                        /* collect OUT data */
1023                         if ((fd->f_flags & O_NONBLOCK) != 0
1024                                         && !dev->setup_out_ready) {
1025                                 retval = -EAGAIN;
1026                                 goto done;
1027                         }
1028                         spin_unlock_irq (&dev->lock);
1029                         retval = wait_event_interruptible (dev->wait,
1030                                         dev->setup_out_ready != 0);
1031
1032                         /* FIXME state could change from under us */
1033                         spin_lock_irq (&dev->lock);
1034                         if (retval)
1035                                 goto done;
1036
1037                         if (dev->state != STATE_DEV_SETUP) {
1038                                 retval = -ECANCELED;
1039                                 goto done;
1040                         }
1041                         dev->state = STATE_DEV_CONNECTED;
1042
1043                         if (dev->setup_out_error)
1044                                 retval = -EIO;
1045                         else {
1046                                 len = min (len, (size_t)dev->req->actual);
1047 // FIXME don't call this with the spinlock held ...
1048                                 if (copy_to_user (buf, dev->req->buf, len))
1049                                         retval = -EFAULT;
1050                                 clean_req (dev->gadget->ep0, dev->req);
1051                                 /* NOTE userspace can't yet choose to stall */
1052                         }
1053                 }
1054                 goto done;
1055         }
1056
1057         /* else normal: return event data */
1058         if (len < sizeof dev->event [0]) {
1059                 retval = -EINVAL;
1060                 goto done;
1061         }
1062         len -= len % sizeof (struct usb_gadgetfs_event);
1063         dev->usermode_setup = 1;
1064
1065 scan:
1066         /* return queued events right away */
1067         if (dev->ev_next != 0) {
1068                 unsigned                i, n;
1069
1070                 n = len / sizeof (struct usb_gadgetfs_event);
1071                 if (dev->ev_next < n)
1072                         n = dev->ev_next;
1073
1074                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1075                 for (i = 0; i < n; i++) {
1076                         if (dev->event [i].type == GADGETFS_SETUP) {
1077                                 dev->state = STATE_DEV_SETUP;
1078                                 n = i + 1;
1079                                 break;
1080                         }
1081                 }
1082                 spin_unlock_irq (&dev->lock);
1083                 len = n * sizeof (struct usb_gadgetfs_event);
1084                 if (copy_to_user (buf, &dev->event, len))
1085                         retval = -EFAULT;
1086                 else
1087                         retval = len;
1088                 if (len > 0) {
1089                         /* NOTE this doesn't guard against broken drivers;
1090                          * concurrent ep0 readers may lose events.
1091                          */
1092                         spin_lock_irq (&dev->lock);
1093                         if (dev->ev_next > n) {
1094                                 memmove(&dev->event[0], &dev->event[n],
1095                                         sizeof (struct usb_gadgetfs_event)
1096                                                 * (dev->ev_next - n));
1097                         }
1098                         dev->ev_next -= n;
1099                         spin_unlock_irq (&dev->lock);
1100                 }
1101                 return retval;
1102         }
1103         if (fd->f_flags & O_NONBLOCK) {
1104                 retval = -EAGAIN;
1105                 goto done;
1106         }
1107
1108         switch (state) {
1109         default:
1110                 DBG (dev, "fail %s, state %d\n", __func__, state);
1111                 retval = -ESRCH;
1112                 break;
1113         case STATE_DEV_UNCONNECTED:
1114         case STATE_DEV_CONNECTED:
1115                 spin_unlock_irq (&dev->lock);
1116                 DBG (dev, "%s wait\n", __func__);
1117
1118                 /* wait for events */
1119                 retval = wait_event_interruptible (dev->wait,
1120                                 dev->ev_next != 0);
1121                 if (retval < 0)
1122                         return retval;
1123                 spin_lock_irq (&dev->lock);
1124                 goto scan;
1125         }
1126
1127 done:
1128         spin_unlock_irq (&dev->lock);
1129         return retval;
1130 }
1131
1132 static struct usb_gadgetfs_event *
1133 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1134 {
1135         struct usb_gadgetfs_event       *event;
1136         unsigned                        i;
1137
1138         switch (type) {
1139         /* these events purge the queue */
1140         case GADGETFS_DISCONNECT:
1141                 if (dev->state == STATE_DEV_SETUP)
1142                         dev->setup_abort = 1;
1143                 // FALL THROUGH
1144         case GADGETFS_CONNECT:
1145                 dev->ev_next = 0;
1146                 break;
1147         case GADGETFS_SETUP:            /* previous request timed out */
1148         case GADGETFS_SUSPEND:          /* same effect */
1149                 /* these events can't be repeated */
1150                 for (i = 0; i != dev->ev_next; i++) {
1151                         if (dev->event [i].type != type)
1152                                 continue;
1153                         DBG(dev, "discard old event[%d] %d\n", i, type);
1154                         dev->ev_next--;
1155                         if (i == dev->ev_next)
1156                                 break;
1157                         /* indices start at zero, for simplicity */
1158                         memmove (&dev->event [i], &dev->event [i + 1],
1159                                 sizeof (struct usb_gadgetfs_event)
1160                                         * (dev->ev_next - i));
1161                 }
1162                 break;
1163         default:
1164                 BUG ();
1165         }
1166         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1167         event = &dev->event [dev->ev_next++];
1168         BUG_ON (dev->ev_next > N_EVENT);
1169         memset (event, 0, sizeof *event);
1170         event->type = type;
1171         return event;
1172 }
1173
1174 static ssize_t
1175 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1176 {
1177         struct dev_data         *dev = fd->private_data;
1178         ssize_t                 retval = -ESRCH;
1179
1180         spin_lock_irq (&dev->lock);
1181
1182         /* report fd mode change before acting on it */
1183         if (dev->setup_abort) {
1184                 dev->setup_abort = 0;
1185                 retval = -EIDRM;
1186
1187         /* data and/or status stage for control request */
1188         } else if (dev->state == STATE_DEV_SETUP) {
1189
1190                 /* IN DATA+STATUS caller makes len <= wLength */
1191                 if (dev->setup_in) {
1192                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1193                         if (retval == 0) {
1194                                 dev->state = STATE_DEV_CONNECTED;
1195                                 spin_unlock_irq (&dev->lock);
1196                                 if (copy_from_user (dev->req->buf, buf, len))
1197                                         retval = -EFAULT;
1198                                 else {
1199                                         if (len < dev->setup_wLength)
1200                                                 dev->req->zero = 1;
1201                                         retval = usb_ep_queue (
1202                                                 dev->gadget->ep0, dev->req,
1203                                                 GFP_KERNEL);
1204                                 }
1205                                 if (retval < 0) {
1206                                         spin_lock_irq (&dev->lock);
1207                                         clean_req (dev->gadget->ep0, dev->req);
1208                                         spin_unlock_irq (&dev->lock);
1209                                 } else
1210                                         retval = len;
1211
1212                                 return retval;
1213                         }
1214
1215                 /* can stall some OUT transfers */
1216                 } else if (dev->setup_can_stall) {
1217                         VDEBUG(dev, "ep0out stall\n");
1218                         (void) usb_ep_set_halt (dev->gadget->ep0);
1219                         retval = -EL2HLT;
1220                         dev->state = STATE_DEV_CONNECTED;
1221                 } else {
1222                         DBG(dev, "bogus ep0out stall!\n");
1223                 }
1224         } else
1225                 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1226
1227         spin_unlock_irq (&dev->lock);
1228         return retval;
1229 }
1230
1231 static int
1232 ep0_fasync (int f, struct file *fd, int on)
1233 {
1234         struct dev_data         *dev = fd->private_data;
1235         // caller must F_SETOWN before signal delivery happens
1236         VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1237         return fasync_helper (f, fd, on, &dev->fasync);
1238 }
1239
1240 static struct usb_gadget_driver gadgetfs_driver;
1241
1242 static int
1243 dev_release (struct inode *inode, struct file *fd)
1244 {
1245         struct dev_data         *dev = fd->private_data;
1246
1247         /* closing ep0 === shutdown all */
1248
1249         usb_gadget_unregister_driver (&gadgetfs_driver);
1250
1251         /* at this point "good" hardware has disconnected the
1252          * device from USB; the host won't see it any more.
1253          * alternatively, all host requests will time out.
1254          */
1255
1256         kfree (dev->buf);
1257         dev->buf = NULL;
1258         put_dev (dev);
1259
1260         /* other endpoints were all decoupled from this device */
1261         spin_lock_irq(&dev->lock);
1262         dev->state = STATE_DEV_DISABLED;
1263         spin_unlock_irq(&dev->lock);
1264         return 0;
1265 }
1266
1267 static unsigned int
1268 ep0_poll (struct file *fd, poll_table *wait)
1269 {
1270        struct dev_data         *dev = fd->private_data;
1271        int                     mask = 0;
1272
1273        poll_wait(fd, &dev->wait, wait);
1274
1275        spin_lock_irq (&dev->lock);
1276
1277        /* report fd mode change before acting on it */
1278        if (dev->setup_abort) {
1279                dev->setup_abort = 0;
1280                mask = POLLHUP;
1281                goto out;
1282        }
1283
1284        if (dev->state == STATE_DEV_SETUP) {
1285                if (dev->setup_in || dev->setup_can_stall)
1286                        mask = POLLOUT;
1287        } else {
1288                if (dev->ev_next != 0)
1289                        mask = POLLIN;
1290        }
1291 out:
1292        spin_unlock_irq(&dev->lock);
1293        return mask;
1294 }
1295
1296 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1297 {
1298         struct dev_data         *dev = fd->private_data;
1299         struct usb_gadget       *gadget = dev->gadget;
1300         long ret = -ENOTTY;
1301
1302         if (gadget->ops->ioctl)
1303                 ret = gadget->ops->ioctl (gadget, code, value);
1304
1305         return ret;
1306 }
1307
1308 /* used after device configuration */
1309 static const struct file_operations ep0_io_operations = {
1310         .owner =        THIS_MODULE,
1311         .llseek =       no_llseek,
1312
1313         .read =         ep0_read,
1314         .write =        ep0_write,
1315         .fasync =       ep0_fasync,
1316         .poll =         ep0_poll,
1317         .unlocked_ioctl =       dev_ioctl,
1318         .release =      dev_release,
1319 };
1320
1321 /*----------------------------------------------------------------------*/
1322
1323 /* The in-kernel gadget driver handles most ep0 issues, in particular
1324  * enumerating the single configuration (as provided from user space).
1325  *
1326  * Unrecognized ep0 requests may be handled in user space.
1327  */
1328
1329 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1330 static void make_qualifier (struct dev_data *dev)
1331 {
1332         struct usb_qualifier_descriptor         qual;
1333         struct usb_device_descriptor            *desc;
1334
1335         qual.bLength = sizeof qual;
1336         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1337         qual.bcdUSB = cpu_to_le16 (0x0200);
1338
1339         desc = dev->dev;
1340         qual.bDeviceClass = desc->bDeviceClass;
1341         qual.bDeviceSubClass = desc->bDeviceSubClass;
1342         qual.bDeviceProtocol = desc->bDeviceProtocol;
1343
1344         /* assumes ep0 uses the same value for both speeds ... */
1345         qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
1346
1347         qual.bNumConfigurations = 1;
1348         qual.bRESERVED = 0;
1349
1350         memcpy (dev->rbuf, &qual, sizeof qual);
1351 }
1352 #endif
1353
1354 static int
1355 config_buf (struct dev_data *dev, u8 type, unsigned index)
1356 {
1357         int             len;
1358         int             hs = 0;
1359
1360         /* only one configuration */
1361         if (index > 0)
1362                 return -EINVAL;
1363
1364         if (gadget_is_dualspeed(dev->gadget)) {
1365                 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1366                 if (type == USB_DT_OTHER_SPEED_CONFIG)
1367                         hs = !hs;
1368         }
1369         if (hs) {
1370                 dev->req->buf = dev->hs_config;
1371                 len = le16_to_cpu(dev->hs_config->wTotalLength);
1372         } else {
1373                 dev->req->buf = dev->config;
1374                 len = le16_to_cpu(dev->config->wTotalLength);
1375         }
1376         ((u8 *)dev->req->buf) [1] = type;
1377         return len;
1378 }
1379
1380 static int
1381 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1382 {
1383         struct dev_data                 *dev = get_gadget_data (gadget);
1384         struct usb_request              *req = dev->req;
1385         int                             value = -EOPNOTSUPP;
1386         struct usb_gadgetfs_event       *event;
1387         u16                             w_value = le16_to_cpu(ctrl->wValue);
1388         u16                             w_length = le16_to_cpu(ctrl->wLength);
1389
1390         spin_lock (&dev->lock);
1391         dev->setup_abort = 0;
1392         if (dev->state == STATE_DEV_UNCONNECTED) {
1393                 if (gadget_is_dualspeed(gadget)
1394                                 && gadget->speed == USB_SPEED_HIGH
1395                                 && dev->hs_config == NULL) {
1396                         spin_unlock(&dev->lock);
1397                         ERROR (dev, "no high speed config??\n");
1398                         return -EINVAL;
1399                 }
1400
1401                 dev->state = STATE_DEV_CONNECTED;
1402                 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1403
1404                 INFO (dev, "connected\n");
1405                 event = next_event (dev, GADGETFS_CONNECT);
1406                 event->u.speed = gadget->speed;
1407                 ep0_readable (dev);
1408
1409         /* host may have given up waiting for response.  we can miss control
1410          * requests handled lower down (device/endpoint status and features);
1411          * then ep0_{read,write} will report the wrong status. controller
1412          * driver will have aborted pending i/o.
1413          */
1414         } else if (dev->state == STATE_DEV_SETUP)
1415                 dev->setup_abort = 1;
1416
1417         req->buf = dev->rbuf;
1418         req->dma = DMA_ADDR_INVALID;
1419         req->context = NULL;
1420         value = -EOPNOTSUPP;
1421         switch (ctrl->bRequest) {
1422
1423         case USB_REQ_GET_DESCRIPTOR:
1424                 if (ctrl->bRequestType != USB_DIR_IN)
1425                         goto unrecognized;
1426                 switch (w_value >> 8) {
1427
1428                 case USB_DT_DEVICE:
1429                         value = min (w_length, (u16) sizeof *dev->dev);
1430                         req->buf = dev->dev;
1431                         break;
1432 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1433                 case USB_DT_DEVICE_QUALIFIER:
1434                         if (!dev->hs_config)
1435                                 break;
1436                         value = min (w_length, (u16)
1437                                 sizeof (struct usb_qualifier_descriptor));
1438                         make_qualifier (dev);
1439                         break;
1440                 case USB_DT_OTHER_SPEED_CONFIG:
1441                         // FALLTHROUGH
1442 #endif
1443                 case USB_DT_CONFIG:
1444                         value = config_buf (dev,
1445                                         w_value >> 8,
1446                                         w_value & 0xff);
1447                         if (value >= 0)
1448                                 value = min (w_length, (u16) value);
1449                         break;
1450                 case USB_DT_STRING:
1451                         goto unrecognized;
1452
1453                 default:                // all others are errors
1454                         break;
1455                 }
1456                 break;
1457
1458         /* currently one config, two speeds */
1459         case USB_REQ_SET_CONFIGURATION:
1460                 if (ctrl->bRequestType != 0)
1461                         goto unrecognized;
1462                 if (0 == (u8) w_value) {
1463                         value = 0;
1464                         dev->current_config = 0;
1465                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1466                         // user mode expected to disable endpoints
1467                 } else {
1468                         u8      config, power;
1469
1470                         if (gadget_is_dualspeed(gadget)
1471                                         && gadget->speed == USB_SPEED_HIGH) {
1472                                 config = dev->hs_config->bConfigurationValue;
1473                                 power = dev->hs_config->bMaxPower;
1474                         } else {
1475                                 config = dev->config->bConfigurationValue;
1476                                 power = dev->config->bMaxPower;
1477                         }
1478
1479                         if (config == (u8) w_value) {
1480                                 value = 0;
1481                                 dev->current_config = config;
1482                                 usb_gadget_vbus_draw(gadget, 2 * power);
1483                         }
1484                 }
1485
1486                 /* report SET_CONFIGURATION like any other control request,
1487                  * except that usermode may not stall this.  the next
1488                  * request mustn't be allowed start until this finishes:
1489                  * endpoints and threads set up, etc.
1490                  *
1491                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1492                  * has bad/racey automagic that prevents synchronizing here.
1493                  * even kernel mode drivers often miss them.
1494                  */
1495                 if (value == 0) {
1496                         INFO (dev, "configuration #%d\n", dev->current_config);
1497                         if (dev->usermode_setup) {
1498                                 dev->setup_can_stall = 0;
1499                                 goto delegate;
1500                         }
1501                 }
1502                 break;
1503
1504 #ifndef CONFIG_USB_GADGET_PXA25X
1505         /* PXA automagically handles this request too */
1506         case USB_REQ_GET_CONFIGURATION:
1507                 if (ctrl->bRequestType != 0x80)
1508                         goto unrecognized;
1509                 *(u8 *)req->buf = dev->current_config;
1510                 value = min (w_length, (u16) 1);
1511                 break;
1512 #endif
1513
1514         default:
1515 unrecognized:
1516                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1517                         dev->usermode_setup ? "delegate" : "fail",
1518                         ctrl->bRequestType, ctrl->bRequest,
1519                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1520
1521                 /* if there's an ep0 reader, don't stall */
1522                 if (dev->usermode_setup) {
1523                         dev->setup_can_stall = 1;
1524 delegate:
1525                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1526                                                 ? 1 : 0;
1527                         dev->setup_wLength = w_length;
1528                         dev->setup_out_ready = 0;
1529                         dev->setup_out_error = 0;
1530                         value = 0;
1531
1532                         /* read DATA stage for OUT right away */
1533                         if (unlikely (!dev->setup_in && w_length)) {
1534                                 value = setup_req (gadget->ep0, dev->req,
1535                                                         w_length);
1536                                 if (value < 0)
1537                                         break;
1538                                 value = usb_ep_queue (gadget->ep0, dev->req,
1539                                                         GFP_ATOMIC);
1540                                 if (value < 0) {
1541                                         clean_req (gadget->ep0, dev->req);
1542                                         break;
1543                                 }
1544
1545                                 /* we can't currently stall these */
1546                                 dev->setup_can_stall = 0;
1547                         }
1548
1549                         /* state changes when reader collects event */
1550                         event = next_event (dev, GADGETFS_SETUP);
1551                         event->u.setup = *ctrl;
1552                         ep0_readable (dev);
1553                         spin_unlock (&dev->lock);
1554                         return 0;
1555                 }
1556         }
1557
1558         /* proceed with data transfer and status phases? */
1559         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1560                 req->length = value;
1561                 req->zero = value < w_length;
1562                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1563                 if (value < 0) {
1564                         DBG (dev, "ep_queue --> %d\n", value);
1565                         req->status = 0;
1566                 }
1567         }
1568
1569         /* device stalls when value < 0 */
1570         spin_unlock (&dev->lock);
1571         return value;
1572 }
1573
1574 static void destroy_ep_files (struct dev_data *dev)
1575 {
1576         struct list_head        *entry, *tmp;
1577
1578         DBG (dev, "%s %d\n", __func__, dev->state);
1579
1580         /* dev->state must prevent interference */
1581 restart:
1582         spin_lock_irq (&dev->lock);
1583         list_for_each_safe (entry, tmp, &dev->epfiles) {
1584                 struct ep_data  *ep;
1585                 struct inode    *parent;
1586                 struct dentry   *dentry;
1587
1588                 /* break link to FS */
1589                 ep = list_entry (entry, 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                 /* fds may still be open */
1613                 goto restart;
1614         }
1615         spin_unlock_irq (&dev->lock);
1616 }
1617
1618
1619 static struct inode *
1620 gadgetfs_create_file (struct super_block *sb, char const *name,
1621                 void *data, const struct file_operations *fops,
1622                 struct dentry **dentry_p);
1623
1624 static int activate_ep_files (struct dev_data *dev)
1625 {
1626         struct usb_ep   *ep;
1627         struct ep_data  *data;
1628
1629         gadget_for_each_ep (ep, dev->gadget) {
1630
1631                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1632                 if (!data)
1633                         goto enomem0;
1634                 data->state = STATE_EP_DISABLED;
1635                 mutex_init(&data->lock);
1636                 init_waitqueue_head (&data->wait);
1637
1638                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1639                 atomic_set (&data->count, 1);
1640                 data->dev = dev;
1641                 get_dev (dev);
1642
1643                 data->ep = ep;
1644                 ep->driver_data = data;
1645
1646                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1647                 if (!data->req)
1648                         goto enomem1;
1649
1650                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1651                                 data, &ep_config_operations,
1652                                 &data->dentry);
1653                 if (!data->inode)
1654                         goto enomem2;
1655                 list_add_tail (&data->epfiles, &dev->epfiles);
1656         }
1657         return 0;
1658
1659 enomem2:
1660         usb_ep_free_request (ep, data->req);
1661 enomem1:
1662         put_dev (dev);
1663         kfree (data);
1664 enomem0:
1665         DBG (dev, "%s enomem\n", __func__);
1666         destroy_ep_files (dev);
1667         return -ENOMEM;
1668 }
1669
1670 static void
1671 gadgetfs_unbind (struct usb_gadget *gadget)
1672 {
1673         struct dev_data         *dev = get_gadget_data (gadget);
1674
1675         DBG (dev, "%s\n", __func__);
1676
1677         spin_lock_irq (&dev->lock);
1678         dev->state = STATE_DEV_UNBOUND;
1679         spin_unlock_irq (&dev->lock);
1680
1681         destroy_ep_files (dev);
1682         gadget->ep0->driver_data = NULL;
1683         set_gadget_data (gadget, NULL);
1684
1685         /* we've already been disconnected ... no i/o is active */
1686         if (dev->req)
1687                 usb_ep_free_request (gadget->ep0, dev->req);
1688         DBG (dev, "%s done\n", __func__);
1689         put_dev (dev);
1690 }
1691
1692 static struct dev_data          *the_device;
1693
1694 static int
1695 gadgetfs_bind (struct usb_gadget *gadget)
1696 {
1697         struct dev_data         *dev = the_device;
1698
1699         if (!dev)
1700                 return -ESRCH;
1701         if (0 != strcmp (CHIP, gadget->name)) {
1702                 pr_err("%s expected %s controller not %s\n",
1703                         shortname, CHIP, gadget->name);
1704                 return -ENODEV;
1705         }
1706
1707         set_gadget_data (gadget, dev);
1708         dev->gadget = gadget;
1709         gadget->ep0->driver_data = dev;
1710         dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
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
1739         spin_lock (&dev->lock);
1740         if (dev->state == STATE_DEV_UNCONNECTED)
1741                 goto exit;
1742         dev->state = STATE_DEV_UNCONNECTED;
1743
1744         INFO (dev, "disconnected\n");
1745         next_event (dev, GADGETFS_DISCONNECT);
1746         ep0_readable (dev);
1747 exit:
1748         spin_unlock (&dev->lock);
1749 }
1750
1751 static void
1752 gadgetfs_suspend (struct usb_gadget *gadget)
1753 {
1754         struct dev_data         *dev = get_gadget_data (gadget);
1755
1756         INFO (dev, "suspended from state %d\n", dev->state);
1757         spin_lock (&dev->lock);
1758         switch (dev->state) {
1759         case STATE_DEV_SETUP:           // VERY odd... host died??
1760         case STATE_DEV_CONNECTED:
1761         case STATE_DEV_UNCONNECTED:
1762                 next_event (dev, GADGETFS_SUSPEND);
1763                 ep0_readable (dev);
1764                 /* FALLTHROUGH */
1765         default:
1766                 break;
1767         }
1768         spin_unlock (&dev->lock);
1769 }
1770
1771 static struct usb_gadget_driver gadgetfs_driver = {
1772 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1773         .speed          = USB_SPEED_HIGH,
1774 #else
1775         .speed          = USB_SPEED_FULL,
1776 #endif
1777         .function       = (char *) driver_desc,
1778         .bind           = gadgetfs_bind,
1779         .unbind         = gadgetfs_unbind,
1780         .setup          = gadgetfs_setup,
1781         .disconnect     = gadgetfs_disconnect,
1782         .suspend        = gadgetfs_suspend,
1783
1784         .driver = {
1785                 .name           = (char *) shortname,
1786         },
1787 };
1788
1789 /*----------------------------------------------------------------------*/
1790
1791 static void gadgetfs_nop(struct usb_gadget *arg) { }
1792
1793 static int gadgetfs_probe (struct usb_gadget *gadget)
1794 {
1795         CHIP = gadget->name;
1796         return -EISNAM;
1797 }
1798
1799 static struct usb_gadget_driver probe_driver = {
1800         .speed          = USB_SPEED_HIGH,
1801         .bind           = gadgetfs_probe,
1802         .unbind         = gadgetfs_nop,
1803         .setup          = (void *)gadgetfs_nop,
1804         .disconnect     = gadgetfs_nop,
1805         .driver = {
1806                 .name           = "nop",
1807         },
1808 };
1809
1810
1811 /* DEVICE INITIALIZATION
1812  *
1813  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1814  *     status = write (fd, descriptors, sizeof descriptors)
1815  *
1816  * That write establishes the device configuration, so the kernel can
1817  * bind to the controller ... guaranteeing it can handle enumeration
1818  * at all necessary speeds.  Descriptor order is:
1819  *
1820  * . message tag (u32, host order) ... for now, must be zero; it
1821  *      would change to support features like multi-config devices
1822  * . full/low speed config ... all wTotalLength bytes (with interface,
1823  *      class, altsetting, endpoint, and other descriptors)
1824  * . high speed config ... all descriptors, for high speed operation;
1825  *      this one's optional except for high-speed hardware
1826  * . device descriptor
1827  *
1828  * Endpoints are not yet enabled. Drivers must wait until device
1829  * configuration and interface altsetting changes create
1830  * the need to configure (or unconfigure) them.
1831  *
1832  * After initialization, the device stays active for as long as that
1833  * $CHIP file is open.  Events must then be read from that descriptor,
1834  * such as configuration notifications.
1835  */
1836
1837 static int is_valid_config (struct usb_config_descriptor *config)
1838 {
1839         return config->bDescriptorType == USB_DT_CONFIG
1840                 && config->bLength == USB_DT_CONFIG_SIZE
1841                 && config->bConfigurationValue != 0
1842                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1843                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1844         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1845         /* FIXME check lengths: walk to end */
1846 }
1847
1848 static ssize_t
1849 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1850 {
1851         struct dev_data         *dev = fd->private_data;
1852         ssize_t                 value = len, length = len;
1853         unsigned                total;
1854         u32                     tag;
1855         char                    *kbuf;
1856
1857         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1858                 return -EINVAL;
1859
1860         /* we might need to change message format someday */
1861         if (copy_from_user (&tag, buf, 4))
1862                 return -EFAULT;
1863         if (tag != 0)
1864                 return -EINVAL;
1865         buf += 4;
1866         length -= 4;
1867
1868         kbuf = memdup_user(buf, length);
1869         if (IS_ERR(kbuf))
1870                 return PTR_ERR(kbuf);
1871
1872         spin_lock_irq (&dev->lock);
1873         value = -EINVAL;
1874         if (dev->buf)
1875                 goto fail;
1876         dev->buf = kbuf;
1877
1878         /* full or low speed config */
1879         dev->config = (void *) kbuf;
1880         total = le16_to_cpu(dev->config->wTotalLength);
1881         if (!is_valid_config (dev->config) || total >= length)
1882                 goto fail;
1883         kbuf += total;
1884         length -= total;
1885
1886         /* optional high speed config */
1887         if (kbuf [1] == USB_DT_CONFIG) {
1888                 dev->hs_config = (void *) kbuf;
1889                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1890                 if (!is_valid_config (dev->hs_config) || total >= length)
1891                         goto fail;
1892                 kbuf += total;
1893                 length -= total;
1894         }
1895
1896         /* could support multiple configs, using another encoding! */
1897
1898         /* device descriptor (tweaked for paranoia) */
1899         if (length != USB_DT_DEVICE_SIZE)
1900                 goto fail;
1901         dev->dev = (void *)kbuf;
1902         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1903                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1904                         || dev->dev->bNumConfigurations != 1)
1905                 goto fail;
1906         dev->dev->bNumConfigurations = 1;
1907         dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1908
1909         /* triggers gadgetfs_bind(); then we can enumerate. */
1910         spin_unlock_irq (&dev->lock);
1911         value = usb_gadget_register_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         .owner =        THIS_MODULE,
1958         .llseek =       no_llseek,
1959
1960         .open =         dev_open,
1961         .write =        dev_config,
1962         .fasync =       ep0_fasync,
1963         .unlocked_ioctl = dev_ioctl,
1964         .release =      dev_release,
1965 };
1966
1967 /*----------------------------------------------------------------------*/
1968
1969 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1970  *
1971  * Mounting the filesystem creates a controller file, used first for
1972  * device configuration then later for event monitoring.
1973  */
1974
1975
1976 /* FIXME PAM etc could set this security policy without mount options
1977  * if epfiles inherited ownership and permissons from ep0 ...
1978  */
1979
1980 static unsigned default_uid;
1981 static unsigned default_gid;
1982 static unsigned default_perm = S_IRUSR | S_IWUSR;
1983
1984 module_param (default_uid, uint, 0644);
1985 module_param (default_gid, uint, 0644);
1986 module_param (default_perm, uint, 0644);
1987
1988
1989 static struct inode *
1990 gadgetfs_make_inode (struct super_block *sb,
1991                 void *data, const struct file_operations *fops,
1992                 int mode)
1993 {
1994         struct inode *inode = new_inode (sb);
1995
1996         if (inode) {
1997                 inode->i_mode = mode;
1998                 inode->i_uid = default_uid;
1999                 inode->i_gid = 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 dentry   *d;
2044         struct dev_data *dev;
2045
2046         if (the_device)
2047                 return -ESRCH;
2048
2049         /* fake probe to determine $CHIP */
2050         (void) usb_gadget_register_driver (&probe_driver);
2051         if (!CHIP)
2052                 return -ENODEV;
2053
2054         /* superblock */
2055         sb->s_blocksize = PAGE_CACHE_SIZE;
2056         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2057         sb->s_magic = GADGETFS_MAGIC;
2058         sb->s_op = &gadget_fs_operations;
2059         sb->s_time_gran = 1;
2060
2061         /* root inode */
2062         inode = gadgetfs_make_inode (sb,
2063                         NULL, &simple_dir_operations,
2064                         S_IFDIR | S_IRUGO | S_IXUGO);
2065         if (!inode)
2066                 goto enomem0;
2067         inode->i_op = &simple_dir_inode_operations;
2068         if (!(d = d_alloc_root (inode)))
2069                 goto enomem1;
2070         sb->s_root = d;
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 enomem2;
2078
2079         dev->sb = sb;
2080         if (!gadgetfs_create_file (sb, CHIP,
2081                                 dev, &dev_init_operations,
2082                                 &dev->dentry))
2083                 goto enomem3;
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 enomem3:
2092         put_dev (dev);
2093 enomem2:
2094         dput (d);
2095 enomem1:
2096         iput (inode);
2097 enomem0:
2098         return -ENOMEM;
2099 }
2100
2101 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2102 static int
2103 gadgetfs_get_sb (struct file_system_type *t, int flags,
2104                 const char *path, void *opts, struct vfsmount *mnt)
2105 {
2106         return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt);
2107 }
2108
2109 static void
2110 gadgetfs_kill_sb (struct super_block *sb)
2111 {
2112         kill_litter_super (sb);
2113         if (the_device) {
2114                 put_dev (the_device);
2115                 the_device = NULL;
2116         }
2117 }
2118
2119 /*----------------------------------------------------------------------*/
2120
2121 static struct file_system_type gadgetfs_type = {
2122         .owner          = THIS_MODULE,
2123         .name           = shortname,
2124         .get_sb         = gadgetfs_get_sb,
2125         .kill_sb        = gadgetfs_kill_sb,
2126 };
2127
2128 /*----------------------------------------------------------------------*/
2129
2130 static int __init init (void)
2131 {
2132         int status;
2133
2134         status = register_filesystem (&gadgetfs_type);
2135         if (status == 0)
2136                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2137                         shortname, driver_desc);
2138         return status;
2139 }
2140 module_init (init);
2141
2142 static void __exit cleanup (void)
2143 {
2144         pr_debug ("unregister %s\n", shortname);
2145         unregister_filesystem (&gadgetfs_type);
2146 }
2147 module_exit (cleanup);
2148