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      DEBUG                   /* data to help fault diagnosis */
  24 // #define      VERBOSE         /* extra debug messages (success too) */
  25
  26 #include <linux/init.h>
  27 #include <linux/module.h>
  28 #include <linux/fs.h>
  29 #include <linux/pagemap.h>
  30 #include <linux/uts.h>
  31 #include <linux/wait.h>
  32 #include <linux/compiler.h>
  33 #include <asm/uaccess.h>
  34 #include <linux/slab.h>
  35
  36 #include <linux/device.h>
  37 #include <linux/moduleparam.h>
  38
  39 #include <linux/usb_gadgetfs.h>
  40 #include <linux/usb_gadget.h>
  41
  42
  43 /*
  44  * The gadgetfs API maps each endpoint to a file descriptor so that you
  45  * can use standard synchronous read/write calls for I/O.  There's some
  46  * O_NONBLOCK and O_ASYNC/FASYNC style i/o support.  Example usermode
  47  * drivers show how this works in practice.  You can also use AIO to
  48  * eliminate I/O gaps between requests, to help when streaming data.
  49  *
  50  * Key parts that must be USB-specific are protocols defining how the
  51  * read/write operations relate to the hardware state machines.  There
  52  * are two types of files.  One type is for the device, implementing ep0.
  53  * The other type is for each IN or OUT endpoint.  In both cases, the
  54  * user mode driver must configure the hardware before using it.
  55  *
  56  * - First, dev_config() is called when /dev/gadget/$CHIP is configured
  57  *   (by writing configuration and device descriptors).  Afterwards it
  58  *   may serve as a source of device events, used to handle all control
  59  *   requests other than basic enumeration.
  60  *
  61  * - Then either immediately, or after a SET_CONFIGURATION control request,
  62  *   ep_config() is called when each /dev/gadget/ep* file is configured
  63  *   (by writing endpoint descriptors).  Afterwards these files are used
  64  *   to write() IN data or to read() OUT data.  To halt the endpoint, a
  65  *   "wrong direction" request is issued (like reading an IN endpoint).
  66  *
  67  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
  68  * not possible on all hardware.  For example, precise fault handling with
  69  * respect to data left in endpoint fifos after aborted operations; or
  70  * selective clearing of endpoint halts, to implement SET_INTERFACE.
  71  */
  72
  73 #define DRIVER_DESC     "USB Gadget filesystem"
  74 #define DRIVER_VERSION  "24 Aug 2004"
  75
  76 static const char driver_desc [] = DRIVER_DESC;
  77 static const char shortname [] = "gadgetfs";
  78
  79 MODULE_DESCRIPTION (DRIVER_DESC);
  80 MODULE_AUTHOR ("David Brownell");
  81 MODULE_LICENSE ("GPL");
  82
  83
  84 /*----------------------------------------------------------------------*/
  85
  86 #define GADGETFS_MAGIC          0xaee71ee7
  87 #define DMA_ADDR_INVALID        (~(dma_addr_t)0)
  88
  89 /* /dev/gadget/$CHIP represents ep0 and the whole device */
  90 enum ep0_state {
  91         /* DISBLED is the initial state.
  92          */
  93         STATE_DEV_DISABLED = 0,
  94
  95         /* Only one open() of /dev/gadget/$CHIP; only one file tracks
  96          * ep0/device i/o modes and binding to the controller.  Driver
  97          * must always write descriptors to initialize the device, then
  98          * the device becomes UNCONNECTED until enumeration.
  99          */
 100         STATE_OPENED,
 101
 102         /* From then on, ep0 fd is in either of two basic modes:
 103          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
 104          * - SETUP: read/write will transfer control data and succeed;
 105          *   or if "wrong direction", performs protocol stall
 106          */
 107         STATE_UNCONNECTED,
 108         STATE_CONNECTED,
 109         STATE_SETUP,
 110
 111         /* UNBOUND means the driver closed ep0, so the device won't be
 112          * accessible again (DEV_DISABLED) until all fds are closed.
 113          */
 114         STATE_DEV_UNBOUND,
 115 };
 116
 117 /* enough for the whole queue: most events invalidate others */
 118 #define N_EVENT                 5
 119
 120 struct dev_data {
 121         spinlock_t                      lock;
 122         atomic_t                        count;
 123         enum ep0_state                  state;
 124         struct usb_gadgetfs_event       event [N_EVENT];
 125         unsigned                        ev_next;
 126         struct fasync_struct            *fasync;
 127         u8                              current_config;
 128
 129         /* drivers reading ep0 MUST handle control requests (SETUP)
 130          * reported that way; else the host will time out.
 131          */
 132         unsigned                        usermode_setup : 1,
 133                                         setup_in : 1,
 134                                         setup_can_stall : 1,
 135                                         setup_out_ready : 1,
 136                                         setup_out_error : 1,
 137                                         setup_abort : 1;
 138         unsigned                        setup_wLength;
 139
 140         /* the rest is basically write-once */
 141         struct usb_config_descriptor    *config, *hs_config;
 142         struct usb_device_descriptor    *dev;
 143         struct usb_request              *req;
 144         struct usb_gadget               *gadget;
 145         struct list_head                epfiles;
 146         void                            *buf;
 147         wait_queue_head_t               wait;
 148         struct super_block              *sb;
 149         struct dentry                   *dentry;
 150
 151         /* except this scratch i/o buffer for ep0 */
 152         u8                              rbuf [256];
 153 };
 154
 155 static inline void get_dev (struct dev_data *data)
 156 {
 157         atomic_inc (&data->count);
 158 }
 159
 160 static void put_dev (struct dev_data *data)
 161 {
 162         if (likely (!atomic_dec_and_test (&data->count)))
 163                 return;
 164         /* needs no more cleanup */
 165         BUG_ON (waitqueue_active (&data->wait));
 166         kfree (data);
 167 }
 168
 169 static struct dev_data *dev_new (void)
 170 {
 171         struct dev_data         *dev;
 172
 173         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 174         if (!dev)
 175                 return NULL;
 176         dev->state = STATE_DEV_DISABLED;
 177         atomic_set (&dev->count, 1);
 178         spin_lock_init (&dev->lock);
 179         INIT_LIST_HEAD (&dev->epfiles);
 180         init_waitqueue_head (&dev->wait);
 181         return dev;
 182 }
 183
 184 /*----------------------------------------------------------------------*/
 185
 186 /* other /dev/gadget/$ENDPOINT files represent endpoints */
 187 enum ep_state {
 188         STATE_EP_DISABLED = 0,
 189         STATE_EP_READY,
 190         STATE_EP_DEFER_ENABLE,
 191         STATE_EP_ENABLED,
 192         STATE_EP_UNBOUND,
 193 };
 194
 195 struct ep_data {
 196         struct semaphore                lock;
 197         enum ep_state                   state;
 198         atomic_t                        count;
 199         struct dev_data                 *dev;
 200         /* must hold dev->lock before accessing ep or req */
 201         struct usb_ep                   *ep;
 202         struct usb_request              *req;
 203         ssize_t                         status;
 204         char                            name [16];
 205         struct usb_endpoint_descriptor  desc, hs_desc;
 206         struct list_head                epfiles;
 207         wait_queue_head_t               wait;
 208         struct dentry                   *dentry;
 209         struct inode                    *inode;
 210 };
 211
 212 static inline void get_ep (struct ep_data *data)
 213 {
 214         atomic_inc (&data->count);
 215 }
 216
 217 static void put_ep (struct ep_data *data)
 218 {
 219         if (likely (!atomic_dec_and_test (&data->count)))
 220                 return;
 221         put_dev (data->dev);
 222         /* needs no more cleanup */
 223         BUG_ON (!list_empty (&data->epfiles));
 224         BUG_ON (waitqueue_active (&data->wait));
 225         BUG_ON (down_trylock (&data->lock) != 0);
 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
 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 WARN(dev,fmt,args...) \
 267         xprintk(dev , KERN_WARNING , fmt , ## args)
 268 #define INFO(dev,fmt,args...) \
 269         xprintk(dev , KERN_INFO , fmt , ## args)
 270
 271
 272 /*----------------------------------------------------------------------*/
 273
 274 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 275  *
 276  * After opening, configure non-control endpoints.  Then use normal
 277  * stream read() and write() requests; and maybe ioctl() to get more
 278  * precise FIFO status when recovering from cancellation.
 279  */
 280
 281 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 282 {
 283         struct ep_data  *epdata = ep->driver_data;
 284
 285         if (!req->context)
 286                 return;
 287         if (req->status)
 288                 epdata->status = req->status;
 289         else
 290                 epdata->status = req->actual;
 291         complete ((struct completion *)req->context);
 292 }
 293
 294 /* tasklock endpoint, returning when it's connected.
 295  * still need dev->lock to use epdata->ep.
 296  */
 297 static int
 298 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
 299 {
 300         int     val;
 301
 302         if (f_flags & O_NONBLOCK) {
 303                 if (down_trylock (&epdata->lock) != 0)
 304                         goto nonblock;
 305                 if (epdata->state != STATE_EP_ENABLED) {
 306                         up (&epdata->lock);
 307 nonblock:
 308                         val = -EAGAIN;
 309                 } else
 310                         val = 0;
 311                 return val;
 312         }
 313
 314         if ((val = down_interruptible (&epdata->lock)) < 0)
 315                 return val;
 316 newstate:
 317         switch (epdata->state) {
 318         case STATE_EP_ENABLED:
 319                 break;
 320         case STATE_EP_DEFER_ENABLE:
 321                 DBG (epdata->dev, "%s wait for host\n", epdata->name);
 322                 if ((val = wait_event_interruptible (epdata->wait,
 323                                 epdata->state != STATE_EP_DEFER_ENABLE
 324                                 || epdata->dev->state == STATE_DEV_UNBOUND
 325                                 )) < 0)
 326                         goto fail;
 327                 goto newstate;
 328         // case STATE_EP_DISABLED:              /* "can't happen" */
 329         // case STATE_EP_READY:                 /* "can't happen" */
 330         default:                                /* error! */
 331                 pr_debug ("%s: ep %p not available, state %d\n",
 332                                 shortname, epdata, epdata->state);
 333                 // FALLTHROUGH
 334         case STATE_EP_UNBOUND:                  /* clean disconnect */
 335                 val = -ENODEV;
 336 fail:
 337                 up (&epdata->lock);
 338         }
 339         return val;
 340 }
 341
 342 static ssize_t
 343 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 344 {
 345         DECLARE_COMPLETION (done);
 346         int value;
 347
 348         spin_lock_irq (&epdata->dev->lock);
 349         if (likely (epdata->ep != NULL)) {
 350                 struct usb_request      *req = epdata->req;
 351
 352                 req->context = &done;
 353                 req->complete = epio_complete;
 354                 req->buf = buf;
 355                 req->length = len;
 356                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 357         } else
 358                 value = -ENODEV;
 359         spin_unlock_irq (&epdata->dev->lock);
 360
 361         if (likely (value == 0)) {
 362                 value = wait_event_interruptible (done.wait, done.done);
 363                 if (value != 0) {
 364                         spin_lock_irq (&epdata->dev->lock);
 365                         if (likely (epdata->ep != NULL)) {
 366                                 DBG (epdata->dev, "%s i/o interrupted\n",
 367                                                 epdata->name);
 368                                 usb_ep_dequeue (epdata->ep, epdata->req);
 369                                 spin_unlock_irq (&epdata->dev->lock);
 370
 371                                 wait_event (done.wait, done.done);
 372                                 if (epdata->status == -ECONNRESET)
 373                                         epdata->status = -EINTR;
 374                         } else {
 375                                 spin_unlock_irq (&epdata->dev->lock);
 376
 377                                 DBG (epdata->dev, "endpoint gone\n");
 378                                 epdata->status = -ENODEV;
 379                         }
 380                 }
 381                 return epdata->status;
 382         }
 383         return value;
 384 }
 385
 386
 387 /* handle a synchronous OUT bulk/intr/iso transfer */
 388 static ssize_t
 389 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 390 {
 391         struct ep_data          *data = fd->private_data;
 392         void                    *kbuf;
 393         ssize_t                 value;
 394
 395         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 396                 return value;
 397
 398         /* halt any endpoint by doing a "wrong direction" i/o call */
 399         if (data->desc.bEndpointAddress & USB_DIR_IN) {
 400                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 401                                 == USB_ENDPOINT_XFER_ISOC)
 402                         return -EINVAL;
 403                 DBG (data->dev, "%s halt\n", data->name);
 404                 spin_lock_irq (&data->dev->lock);
 405                 if (likely (data->ep != NULL))
 406                         usb_ep_set_halt (data->ep);
 407                 spin_unlock_irq (&data->dev->lock);
 408                 up (&data->lock);
 409                 return -EBADMSG;
 410         }
 411
 412         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
 413
 414         value = -ENOMEM;
 415         kbuf = kmalloc (len, SLAB_KERNEL);
 416         if (unlikely (!kbuf))
 417                 goto free1;
 418
 419         value = ep_io (data, kbuf, len);
 420         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
 421                 data->name, len, (int) value);
 422         if (value >= 0 && copy_to_user (buf, kbuf, value))
 423                 value = -EFAULT;
 424
 425 free1:
 426         up (&data->lock);
 427         kfree (kbuf);
 428         return value;
 429 }
 430
 431 /* handle a synchronous IN bulk/intr/iso transfer */
 432 static ssize_t
 433 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 434 {
 435         struct ep_data          *data = fd->private_data;
 436         void                    *kbuf;
 437         ssize_t                 value;
 438
 439         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 440                 return value;
 441
 442         /* halt any endpoint by doing a "wrong direction" i/o call */
 443         if (!(data->desc.bEndpointAddress & USB_DIR_IN)) {
 444                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 445                                 == USB_ENDPOINT_XFER_ISOC)
 446                         return -EINVAL;
 447                 DBG (data->dev, "%s halt\n", data->name);
 448                 spin_lock_irq (&data->dev->lock);
 449                 if (likely (data->ep != NULL))
 450                         usb_ep_set_halt (data->ep);
 451                 spin_unlock_irq (&data->dev->lock);
 452                 up (&data->lock);
 453                 return -EBADMSG;
 454         }
 455
 456         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
 457
 458         value = -ENOMEM;
 459         kbuf = kmalloc (len, SLAB_KERNEL);
 460         if (!kbuf)
 461                 goto free1;
 462         if (copy_from_user (kbuf, buf, len)) {
 463                 value = -EFAULT;
 464                 goto free1;
 465         }
 466
 467         value = ep_io (data, kbuf, len);
 468         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
 469                 data->name, len, (int) value);
 470 free1:
 471         up (&data->lock);
 472         kfree (kbuf);
 473         return value;
 474 }
 475
 476 static int
 477 ep_release (struct inode *inode, struct file *fd)
 478 {
 479         struct ep_data          *data = fd->private_data;
 480         int value;
 481
 482         if ((value = down_interruptible(&data->lock)) < 0)
 483                 return value;
 484
 485         /* clean up if this can be reopened */
 486         if (data->state != STATE_EP_UNBOUND) {
 487                 data->state = STATE_EP_DISABLED;
 488                 data->desc.bDescriptorType = 0;
 489                 data->hs_desc.bDescriptorType = 0;
 490                 usb_ep_disable(data->ep);
 491         }
 492         up (&data->lock);
 493         put_ep (data);
 494         return 0;
 495 }
 496
 497 static int ep_ioctl (struct inode *inode, struct file *fd,
 498                 unsigned code, unsigned long value)
 499 {
 500         struct ep_data          *data = fd->private_data;
 501         int                     status;
 502
 503         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 504                 return status;
 505
 506         spin_lock_irq (&data->dev->lock);
 507         if (likely (data->ep != NULL)) {
 508                 switch (code) {
 509                 case GADGETFS_FIFO_STATUS:
 510                         status = usb_ep_fifo_status (data->ep);
 511                         break;
 512                 case GADGETFS_FIFO_FLUSH:
 513                         usb_ep_fifo_flush (data->ep);
 514                         break;
 515                 case GADGETFS_CLEAR_HALT:
 516                         status = usb_ep_clear_halt (data->ep);
 517                         break;
 518                 default:
 519                         status = -ENOTTY;
 520                 }
 521         } else
 522                 status = -ENODEV;
 523         spin_unlock_irq (&data->dev->lock);
 524         up (&data->lock);
 525         return status;
 526 }
 527
 528 /*----------------------------------------------------------------------*/
 529
 530 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 531
 532 struct kiocb_priv {
 533         struct usb_request      *req;
 534         struct ep_data          *epdata;
 535         void                    *buf;
 536         char __user             *ubuf;          /* NULL for writes */
 537         unsigned                actual;
 538 };
 539
 540 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
 541 {
 542         struct kiocb_priv       *priv = iocb->private;
 543         struct ep_data          *epdata;
 544         int                     value;
 545
 546         local_irq_disable();
 547         epdata = priv->epdata;
 548         // spin_lock(&epdata->dev->lock);
 549         kiocbSetCancelled(iocb);
 550         if (likely(epdata && epdata->ep && priv->req))
 551                 value = usb_ep_dequeue (epdata->ep, priv->req);
 552         else
 553                 value = -EINVAL;
 554         // spin_unlock(&epdata->dev->lock);
 555         local_irq_enable();
 556
 557         aio_put_req(iocb);
 558         return value;
 559 }
 560
 561 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
 562 {
 563         struct kiocb_priv       *priv = iocb->private;
 564         ssize_t                 status = priv->actual;
 565
 566         /* we "retry" to get the right mm context for this: */
 567         status = copy_to_user(priv->ubuf, priv->buf, priv->actual);
 568         if (unlikely(0 != status))
 569                 status = -EFAULT;
 570         else
 571                 status = priv->actual;
 572         kfree(priv->buf);
 573         kfree(priv);
 574         return status;
 575 }
 576
 577 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 578 {
 579         struct kiocb            *iocb = req->context;
 580         struct kiocb_priv       *priv = iocb->private;
 581         struct ep_data          *epdata = priv->epdata;
 582
 583         /* lock against disconnect (and ideally, cancel) */
 584         spin_lock(&epdata->dev->lock);
 585         priv->req = NULL;
 586         priv->epdata = NULL;
 587         if (priv->ubuf == NULL
 588                         || unlikely(req->actual == 0)
 589                         || unlikely(kiocbIsCancelled(iocb))) {
 590                 kfree(req->buf);
 591                 kfree(priv);
 592                 iocb->private = NULL;
 593                 /* aio_complete() reports bytes-transferred _and_ faults */
 594                 if (unlikely(kiocbIsCancelled(iocb)))
 595                         aio_put_req(iocb);
 596                 else
 597                         aio_complete(iocb,
 598                                 req->actual ? req->actual : req->status,
 599                                 req->status);
 600         } else {
 601                 /* retry() won't report both; so we hide some faults */
 602                 if (unlikely(0 != req->status))
 603                         DBG(epdata->dev, "%s fault %d len %d\n",
 604                                 ep->name, req->status, req->actual);
 605
 606                 priv->buf = req->buf;
 607                 priv->actual = req->actual;
 608                 kick_iocb(iocb);
 609         }
 610         spin_unlock(&epdata->dev->lock);
 611
 612         usb_ep_free_request(ep, req);
 613         put_ep(epdata);
 614 }
 615
 616 static ssize_t
 617 ep_aio_rwtail(
 618         struct kiocb    *iocb,
 619         char            *buf,
 620         size_t          len,
 621         struct ep_data  *epdata,
 622         char __user     *ubuf
 623 )
 624 {
 625         struct kiocb_priv       *priv;
 626         struct usb_request      *req;
 627         ssize_t                 value;
 628
 629         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 630         if (!priv) {
 631                 value = -ENOMEM;
 632 fail:
 633                 kfree(buf);
 634                 return value;
 635         }
 636         iocb->private = priv;
 637         priv->ubuf = ubuf;
 638
 639         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 640         if (unlikely(value < 0)) {
 641                 kfree(priv);
 642                 goto fail;
 643         }
 644
 645         iocb->ki_cancel = ep_aio_cancel;
 646         get_ep(epdata);
 647         priv->epdata = epdata;
 648         priv->actual = 0;
 649
 650         /* each kiocb is coupled to one usb_request, but we can't
 651          * allocate or submit those if the host disconnected.
 652          */
 653         spin_lock_irq(&epdata->dev->lock);
 654         if (likely(epdata->ep)) {
 655                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 656                 if (likely(req)) {
 657                         priv->req = req;
 658                         req->buf = buf;
 659                         req->length = len;
 660                         req->complete = ep_aio_complete;
 661                         req->context = iocb;
 662                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 663                         if (unlikely(0 != value))
 664                                 usb_ep_free_request(epdata->ep, req);
 665                 } else
 666                         value = -EAGAIN;
 667         } else
 668                 value = -ENODEV;
 669         spin_unlock_irq(&epdata->dev->lock);
 670
 671         up(&epdata->lock);
 672
 673         if (unlikely(value)) {
 674                 kfree(priv);
 675                 put_ep(epdata);
 676         } else
 677                 value = (ubuf ? -EIOCBRETRY : -EIOCBQUEUED);
 678         return value;
 679 }
 680
 681 static ssize_t
 682 ep_aio_read(struct kiocb *iocb, char __user *ubuf, size_t len, loff_t o)
 683 {
 684         struct ep_data          *epdata = iocb->ki_filp->private_data;
 685         char                    *buf;
 686
 687         if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN))
 688                 return -EINVAL;
 689         buf = kmalloc(len, GFP_KERNEL);
 690         if (unlikely(!buf))
 691                 return -ENOMEM;
 692         iocb->ki_retry = ep_aio_read_retry;
 693         return ep_aio_rwtail(iocb, buf, len, epdata, ubuf);
 694 }
 695
 696 static ssize_t
 697 ep_aio_write(struct kiocb *iocb, const char __user *ubuf, size_t len, loff_t o)
 698 {
 699         struct ep_data          *epdata = iocb->ki_filp->private_data;
 700         char                    *buf;
 701
 702         if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN)))
 703                 return -EINVAL;
 704         buf = kmalloc(len, GFP_KERNEL);
 705         if (unlikely(!buf))
 706                 return -ENOMEM;
 707         if (unlikely(copy_from_user(buf, ubuf, len) != 0)) {
 708                 kfree(buf);
 709                 return -EFAULT;
 710         }
 711         return ep_aio_rwtail(iocb, buf, len, epdata, NULL);
 712 }
 713
 714 /*----------------------------------------------------------------------*/
 715
 716 /* used after endpoint configuration */
 717 static const struct file_operations ep_io_operations = {
 718         .owner =        THIS_MODULE,
 719         .llseek =       no_llseek,
 720
 721         .read =         ep_read,
 722         .write =        ep_write,
 723         .ioctl =        ep_ioctl,
 724         .release =      ep_release,
 725
 726         .aio_read =     ep_aio_read,
 727         .aio_write =    ep_aio_write,
 728 };
 729
 730 /* ENDPOINT INITIALIZATION
 731  *
 732  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 733  *     status = write (fd, descriptors, sizeof descriptors)
 734  *
 735  * That write establishes the endpoint configuration, configuring
 736  * the controller to process bulk, interrupt, or isochronous transfers
 737  * at the right maxpacket size, and so on.
 738  *
 739  * The descriptors are message type 1, identified by a host order u32
 740  * at the beginning of what's written.  Descriptor order is: full/low
 741  * speed descriptor, then optional high speed descriptor.
 742  */
 743 static ssize_t
 744 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 745 {
 746         struct ep_data          *data = fd->private_data;
 747         struct usb_ep           *ep;
 748         u32                     tag;
 749         int                     value, length = len;
 750
 751         if ((value = down_interruptible (&data->lock)) < 0)
 752                 return value;
 753
 754         if (data->state != STATE_EP_READY) {
 755                 value = -EL2HLT;
 756                 goto fail;
 757         }
 758
 759         value = len;
 760         if (len < USB_DT_ENDPOINT_SIZE + 4)
 761                 goto fail0;
 762
 763         /* we might need to change message format someday */
 764         if (copy_from_user (&tag, buf, 4)) {
 765                 goto fail1;
 766         }
 767         if (tag != 1) {
 768                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 769                 goto fail0;
 770         }
 771         buf += 4;
 772         len -= 4;
 773
 774         /* NOTE:  audio endpoint extensions not accepted here;
 775          * just don't include the extra bytes.
 776          */
 777
 778         /* full/low speed descriptor, then high speed */
 779         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 780                 goto fail1;
 781         }
 782         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 783                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 784                 goto fail0;
 785         if (len != USB_DT_ENDPOINT_SIZE) {
 786                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 787                         goto fail0;
 788                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 789                                         USB_DT_ENDPOINT_SIZE)) {
 790                         goto fail1;
 791                 }
 792                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 793                                 || data->hs_desc.bDescriptorType
 794                                         != USB_DT_ENDPOINT) {
 795                         DBG(data->dev, "config %s, bad hs length or type\n",
 796                                         data->name);
 797                         goto fail0;
 798                 }
 799         }
 800
 801         spin_lock_irq (&data->dev->lock);
 802         if (data->dev->state == STATE_DEV_UNBOUND) {
 803                 value = -ENOENT;
 804                 goto gone;
 805         } else if ((ep = data->ep) == NULL) {
 806                 value = -ENODEV;
 807                 goto gone;
 808         }
 809         switch (data->dev->gadget->speed) {
 810         case USB_SPEED_LOW:
 811         case USB_SPEED_FULL:
 812                 value = usb_ep_enable (ep, &data->desc);
 813                 if (value == 0)
 814                         data->state = STATE_EP_ENABLED;
 815                 break;
 816 #ifdef  CONFIG_USB_GADGET_DUALSPEED
 817         case USB_SPEED_HIGH:
 818                 /* fails if caller didn't provide that descriptor... */
 819                 value = usb_ep_enable (ep, &data->hs_desc);
 820                 if (value == 0)
 821                         data->state = STATE_EP_ENABLED;
 822                 break;
 823 #endif
 824         default:
 825                 DBG (data->dev, "unconnected, %s init deferred\n",
 826                                 data->name);
 827                 data->state = STATE_EP_DEFER_ENABLE;
 828         }
 829         if (value == 0) {
 830                 fd->f_op = &ep_io_operations;
 831                 value = length;
 832         }
 833 gone:
 834         spin_unlock_irq (&data->dev->lock);
 835         if (value < 0) {
 836 fail:
 837                 data->desc.bDescriptorType = 0;
 838                 data->hs_desc.bDescriptorType = 0;
 839         }
 840         up (&data->lock);
 841         return value;
 842 fail0:
 843         value = -EINVAL;
 844         goto fail;
 845 fail1:
 846         value = -EFAULT;
 847         goto fail;
 848 }
 849
 850 static int
 851 ep_open (struct inode *inode, struct file *fd)
 852 {
 853         struct ep_data          *data = inode->i_private;
 854         int                     value = -EBUSY;
 855
 856         if (down_interruptible (&data->lock) != 0)
 857                 return -EINTR;
 858         spin_lock_irq (&data->dev->lock);
 859         if (data->dev->state == STATE_DEV_UNBOUND)
 860                 value = -ENOENT;
 861         else if (data->state == STATE_EP_DISABLED) {
 862                 value = 0;
 863                 data->state = STATE_EP_READY;
 864                 get_ep (data);
 865                 fd->private_data = data;
 866                 VDEBUG (data->dev, "%s ready\n", data->name);
 867         } else
 868                 DBG (data->dev, "%s state %d\n",
 869                         data->name, data->state);
 870         spin_unlock_irq (&data->dev->lock);
 871         up (&data->lock);
 872         return value;
 873 }
 874
 875 /* used before endpoint configuration */
 876 static const struct file_operations ep_config_operations = {
 877         .owner =        THIS_MODULE,
 878         .llseek =       no_llseek,
 879
 880         .open =         ep_open,
 881         .write =        ep_config,
 882         .release =      ep_release,
 883 };
 884
 885 /*----------------------------------------------------------------------*/
 886
 887 /* EP0 IMPLEMENTATION can be partly in userspace.
 888  *
 889  * Drivers that use this facility receive various events, including
 890  * control requests the kernel doesn't handle.  Drivers that don't
 891  * use this facility may be too simple-minded for real applications.
 892  */
 893
 894 static inline void ep0_readable (struct dev_data *dev)
 895 {
 896         wake_up (&dev->wait);
 897         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 898 }
 899
 900 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 901 {
 902         struct dev_data         *dev = ep->driver_data;
 903
 904         if (req->buf != dev->rbuf) {
 905                 usb_ep_free_buffer (ep, req->buf, req->dma, req->length);
 906                 req->buf = dev->rbuf;
 907                 req->dma = DMA_ADDR_INVALID;
 908         }
 909         req->complete = epio_complete;
 910         dev->setup_out_ready = 0;
 911 }
 912
 913 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 914 {
 915         struct dev_data         *dev = ep->driver_data;
 916         int                     free = 1;
 917
 918         /* for control OUT, data must still get to userspace */
 919         if (!dev->setup_in) {
 920                 dev->setup_out_error = (req->status != 0);
 921                 if (!dev->setup_out_error)
 922                         free = 0;
 923                 dev->setup_out_ready = 1;
 924                 ep0_readable (dev);
 925         } else if (dev->state == STATE_SETUP)
 926                 dev->state = STATE_CONNECTED;
 927
 928         /* clean up as appropriate */
 929         if (free && req->buf != &dev->rbuf)
 930                 clean_req (ep, req);
 931         req->complete = epio_complete;
 932 }
 933
 934 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 935 {
 936         struct dev_data *dev = ep->driver_data;
 937
 938         if (dev->setup_out_ready) {
 939                 DBG (dev, "ep0 request busy!\n");
 940                 return -EBUSY;
 941         }
 942         if (len > sizeof (dev->rbuf))
 943                 req->buf = usb_ep_alloc_buffer (ep, len, &req->dma, GFP_ATOMIC);
 944         if (req->buf == 0) {
 945                 req->buf = dev->rbuf;
 946                 return -ENOMEM;
 947         }
 948         req->complete = ep0_complete;
 949         req->length = len;
 950         req->zero = 0;
 951         return 0;
 952 }
 953
 954 static ssize_t
 955 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 956 {
 957         struct dev_data                 *dev = fd->private_data;
 958         ssize_t                         retval;
 959         enum ep0_state                  state;
 960
 961         spin_lock_irq (&dev->lock);
 962
 963         /* report fd mode change before acting on it */
 964         if (dev->setup_abort) {
 965                 dev->setup_abort = 0;
 966                 retval = -EIDRM;
 967                 goto done;
 968         }
 969
 970         /* control DATA stage */
 971         if ((state = dev->state) == STATE_SETUP) {
 972
 973                 if (dev->setup_in) {            /* stall IN */
 974                         VDEBUG(dev, "ep0in stall\n");
 975                         (void) usb_ep_set_halt (dev->gadget->ep0);
 976                         retval = -EL2HLT;
 977                         dev->state = STATE_CONNECTED;
 978
 979                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
 980                         struct usb_ep           *ep = dev->gadget->ep0;
 981                         struct usb_request      *req = dev->req;
 982
 983                         if ((retval = setup_req (ep, req, 0)) == 0)
 984                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
 985                         dev->state = STATE_CONNECTED;
 986
 987                         /* assume that was SET_CONFIGURATION */
 988                         if (dev->current_config) {
 989                                 unsigned power;
 990 #ifdef  CONFIG_USB_GADGET_DUALSPEED
 991                                 if (dev->gadget->speed == USB_SPEED_HIGH)
 992                                         power = dev->hs_config->bMaxPower;
 993                                 else
 994 #endif
 995                                         power = dev->config->bMaxPower;
 996                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
 997                         }
 998
 999                 } else {                        /* collect OUT data */
1000                         if ((fd->f_flags & O_NONBLOCK) != 0
1001                                         && !dev->setup_out_ready) {
1002                                 retval = -EAGAIN;
1003                                 goto done;
1004                         }
1005                         spin_unlock_irq (&dev->lock);
1006                         retval = wait_event_interruptible (dev->wait,
1007                                         dev->setup_out_ready != 0);
1008
1009                         /* FIXME state could change from under us */
1010                         spin_lock_irq (&dev->lock);
1011                         if (retval)
1012                                 goto done;
1013                         if (dev->setup_out_error)
1014                                 retval = -EIO;
1015                         else {
1016                                 len = min (len, (size_t)dev->req->actual);
1017 // FIXME don't call this with the spinlock held ...
1018                                 if (copy_to_user (buf, &dev->req->buf, len))
1019                                         retval = -EFAULT;
1020                                 clean_req (dev->gadget->ep0, dev->req);
1021                                 /* NOTE userspace can't yet choose to stall */
1022                         }
1023                 }
1024                 goto done;
1025         }
1026
1027         /* else normal: return event data */
1028         if (len < sizeof dev->event [0]) {
1029                 retval = -EINVAL;
1030                 goto done;
1031         }
1032         len -= len % sizeof (struct usb_gadgetfs_event);
1033         dev->usermode_setup = 1;
1034
1035 scan:
1036         /* return queued events right away */
1037         if (dev->ev_next != 0) {
1038                 unsigned                i, n;
1039                 int                     tmp = dev->ev_next;
1040
1041                 len = min (len, tmp * sizeof (struct usb_gadgetfs_event));
1042                 n = len / sizeof (struct usb_gadgetfs_event);
1043
1044                 /* ep0 can't deliver events when STATE_SETUP */
1045                 for (i = 0; i < n; i++) {
1046                         if (dev->event [i].type == GADGETFS_SETUP) {
1047                                 len = i + 1;
1048                                 len *= sizeof (struct usb_gadgetfs_event);
1049                                 n = 0;
1050                                 break;
1051                         }
1052                 }
1053                 spin_unlock_irq (&dev->lock);
1054                 if (copy_to_user (buf, &dev->event, len))
1055                         retval = -EFAULT;
1056                 else
1057                         retval = len;
1058                 if (len > 0) {
1059                         len /= sizeof (struct usb_gadgetfs_event);
1060
1061                         /* NOTE this doesn't guard against broken drivers;
1062                          * concurrent ep0 readers may lose events.
1063                          */
1064                         spin_lock_irq (&dev->lock);
1065                         dev->ev_next -= len;
1066                         if (dev->ev_next != 0)
1067                                 memmove (&dev->event, &dev->event [len],
1068                                         sizeof (struct usb_gadgetfs_event)
1069                                                 * (tmp - len));
1070                         if (n == 0)
1071                                 dev->state = STATE_SETUP;
1072                         spin_unlock_irq (&dev->lock);
1073                 }
1074                 return retval;
1075         }
1076         if (fd->f_flags & O_NONBLOCK) {
1077                 retval = -EAGAIN;
1078                 goto done;
1079         }
1080
1081         switch (state) {
1082         default:
1083                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, state);
1084                 retval = -ESRCH;
1085                 break;
1086         case STATE_UNCONNECTED:
1087         case STATE_CONNECTED:
1088                 spin_unlock_irq (&dev->lock);
1089                 DBG (dev, "%s wait\n", __FUNCTION__);
1090
1091                 /* wait for events */
1092                 retval = wait_event_interruptible (dev->wait,
1093                                 dev->ev_next != 0);
1094                 if (retval < 0)
1095                         return retval;
1096                 spin_lock_irq (&dev->lock);
1097                 goto scan;
1098         }
1099
1100 done:
1101         spin_unlock_irq (&dev->lock);
1102         return retval;
1103 }
1104
1105 static struct usb_gadgetfs_event *
1106 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1107 {
1108         struct usb_gadgetfs_event       *event;
1109         unsigned                        i;
1110
1111         switch (type) {
1112         /* these events purge the queue */
1113         case GADGETFS_DISCONNECT:
1114                 if (dev->state == STATE_SETUP)
1115                         dev->setup_abort = 1;
1116                 // FALL THROUGH
1117         case GADGETFS_CONNECT:
1118                 dev->ev_next = 0;
1119                 break;
1120         case GADGETFS_SETUP:            /* previous request timed out */
1121         case GADGETFS_SUSPEND:          /* same effect */
1122                 /* these events can't be repeated */
1123                 for (i = 0; i != dev->ev_next; i++) {
1124                         if (dev->event [i].type != type)
1125                                 continue;
1126                         DBG (dev, "discard old event %d\n", type);
1127                         dev->ev_next--;
1128                         if (i == dev->ev_next)
1129                                 break;
1130                         /* indices start at zero, for simplicity */
1131                         memmove (&dev->event [i], &dev->event [i + 1],
1132                                 sizeof (struct usb_gadgetfs_event)
1133                                         * (dev->ev_next - i));
1134                 }
1135                 break;
1136         default:
1137                 BUG ();
1138         }
1139         event = &dev->event [dev->ev_next++];
1140         BUG_ON (dev->ev_next > N_EVENT);
1141         VDEBUG (dev, "ev %d, next %d\n", type, dev->ev_next);
1142         memset (event, 0, sizeof *event);
1143         event->type = type;
1144         return event;
1145 }
1146
1147 static ssize_t
1148 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1149 {
1150         struct dev_data         *dev = fd->private_data;
1151         ssize_t                 retval = -ESRCH;
1152
1153         spin_lock_irq (&dev->lock);
1154
1155         /* report fd mode change before acting on it */
1156         if (dev->setup_abort) {
1157                 dev->setup_abort = 0;
1158                 retval = -EIDRM;
1159
1160         /* data and/or status stage for control request */
1161         } else if (dev->state == STATE_SETUP) {
1162
1163                 /* IN DATA+STATUS caller makes len <= wLength */
1164                 if (dev->setup_in) {
1165                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1166                         if (retval == 0) {
1167                                 spin_unlock_irq (&dev->lock);
1168                                 if (copy_from_user (dev->req->buf, buf, len))
1169                                         retval = -EFAULT;
1170                                 else {
1171                                         if (len < dev->setup_wLength)
1172                                                 dev->req->zero = 1;
1173                                         retval = usb_ep_queue (
1174                                                 dev->gadget->ep0, dev->req,
1175                                                 GFP_KERNEL);
1176                                 }
1177                                 if (retval < 0) {
1178                                         spin_lock_irq (&dev->lock);
1179                                         clean_req (dev->gadget->ep0, dev->req);
1180                                         spin_unlock_irq (&dev->lock);
1181                                 } else
1182                                         retval = len;
1183
1184                                 return retval;
1185                         }
1186
1187                 /* can stall some OUT transfers */
1188                 } else if (dev->setup_can_stall) {
1189                         VDEBUG(dev, "ep0out stall\n");
1190                         (void) usb_ep_set_halt (dev->gadget->ep0);
1191                         retval = -EL2HLT;
1192                         dev->state = STATE_CONNECTED;
1193                 } else {
1194                         DBG(dev, "bogus ep0out stall!\n");
1195                 }
1196         } else
1197                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state);
1198
1199         spin_unlock_irq (&dev->lock);
1200         return retval;
1201 }
1202
1203 static int
1204 ep0_fasync (int f, struct file *fd, int on)
1205 {
1206         struct dev_data         *dev = fd->private_data;
1207         // caller must F_SETOWN before signal delivery happens
1208         VDEBUG (dev, "%s %s\n", __FUNCTION__, on ? "on" : "off");
1209         return fasync_helper (f, fd, on, &dev->fasync);
1210 }
1211
1212 static struct usb_gadget_driver gadgetfs_driver;
1213
1214 static int
1215 dev_release (struct inode *inode, struct file *fd)
1216 {
1217         struct dev_data         *dev = fd->private_data;
1218
1219         /* closing ep0 === shutdown all */
1220
1221         usb_gadget_unregister_driver (&gadgetfs_driver);
1222
1223         /* at this point "good" hardware has disconnected the
1224          * device from USB; the host won't see it any more.
1225          * alternatively, all host requests will time out.
1226          */
1227
1228         fasync_helper (-1, fd, 0, &dev->fasync);
1229         kfree (dev->buf);
1230         dev->buf = NULL;
1231         put_dev (dev);
1232
1233         /* other endpoints were all decoupled from this device */
1234         dev->state = STATE_DEV_DISABLED;
1235         return 0;
1236 }
1237
1238 static int dev_ioctl (struct inode *inode, struct file *fd,
1239                 unsigned code, unsigned long value)
1240 {
1241         struct dev_data         *dev = fd->private_data;
1242         struct usb_gadget       *gadget = dev->gadget;
1243
1244         if (gadget->ops->ioctl)
1245                 return gadget->ops->ioctl (gadget, code, value);
1246         return -ENOTTY;
1247 }
1248
1249 /* used after device configuration */
1250 static const struct file_operations ep0_io_operations = {
1251         .owner =        THIS_MODULE,
1252         .llseek =       no_llseek,
1253
1254         .read =         ep0_read,
1255         .write =        ep0_write,
1256         .fasync =       ep0_fasync,
1257         // .poll =      ep0_poll,
1258         .ioctl =        dev_ioctl,
1259         .release =      dev_release,
1260 };
1261
1262 /*----------------------------------------------------------------------*/
1263
1264 /* The in-kernel gadget driver handles most ep0 issues, in particular
1265  * enumerating the single configuration (as provided from user space).
1266  *
1267  * Unrecognized ep0 requests may be handled in user space.
1268  */
1269
1270 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1271 static void make_qualifier (struct dev_data *dev)
1272 {
1273         struct usb_qualifier_descriptor         qual;
1274         struct usb_device_descriptor            *desc;
1275
1276         qual.bLength = sizeof qual;
1277         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1278         qual.bcdUSB = __constant_cpu_to_le16 (0x0200);
1279
1280         desc = dev->dev;
1281         qual.bDeviceClass = desc->bDeviceClass;
1282         qual.bDeviceSubClass = desc->bDeviceSubClass;
1283         qual.bDeviceProtocol = desc->bDeviceProtocol;
1284
1285         /* assumes ep0 uses the same value for both speeds ... */
1286         qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
1287
1288         qual.bNumConfigurations = 1;
1289         qual.bRESERVED = 0;
1290
1291         memcpy (dev->rbuf, &qual, sizeof qual);
1292 }
1293 #endif
1294
1295 static int
1296 config_buf (struct dev_data *dev, u8 type, unsigned index)
1297 {
1298         int             len;
1299 #ifdef CONFIG_USB_GADGET_DUALSPEED
1300         int             hs;
1301 #endif
1302
1303         /* only one configuration */
1304         if (index > 0)
1305                 return -EINVAL;
1306
1307 #ifdef CONFIG_USB_GADGET_DUALSPEED
1308         hs = (dev->gadget->speed == USB_SPEED_HIGH);
1309         if (type == USB_DT_OTHER_SPEED_CONFIG)
1310                 hs = !hs;
1311         if (hs) {
1312                 dev->req->buf = dev->hs_config;
1313                 len = le16_to_cpup (&dev->hs_config->wTotalLength);
1314         } else
1315 #endif
1316         {
1317                 dev->req->buf = dev->config;
1318                 len = le16_to_cpup (&dev->config->wTotalLength);
1319         }
1320         ((u8 *)dev->req->buf) [1] = type;
1321         return len;
1322 }
1323
1324 static int
1325 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1326 {
1327         struct dev_data                 *dev = get_gadget_data (gadget);
1328         struct usb_request              *req = dev->req;
1329         int                             value = -EOPNOTSUPP;
1330         struct usb_gadgetfs_event       *event;
1331         u16                             w_value = le16_to_cpu(ctrl->wValue);
1332         u16                             w_length = le16_to_cpu(ctrl->wLength);
1333
1334         spin_lock (&dev->lock);
1335         dev->setup_abort = 0;
1336         if (dev->state == STATE_UNCONNECTED) {
1337                 struct usb_ep   *ep;
1338                 struct ep_data  *data;
1339
1340                 dev->state = STATE_CONNECTED;
1341                 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1342
1343 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1344                 if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) {
1345                         ERROR (dev, "no high speed config??\n");
1346                         return -EINVAL;
1347                 }
1348 #endif  /* CONFIG_USB_GADGET_DUALSPEED */
1349
1350                 INFO (dev, "connected\n");
1351                 event = next_event (dev, GADGETFS_CONNECT);
1352                 event->u.speed = gadget->speed;
1353                 ep0_readable (dev);
1354
1355                 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
1356                         data = ep->driver_data;
1357                         /* ... down_trylock (&data->lock) ... */
1358                         if (data->state != STATE_EP_DEFER_ENABLE)
1359                                 continue;
1360 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1361                         if (gadget->speed == USB_SPEED_HIGH)
1362                                 value = usb_ep_enable (ep, &data->hs_desc);
1363                         else
1364 #endif  /* CONFIG_USB_GADGET_DUALSPEED */
1365                                 value = usb_ep_enable (ep, &data->desc);
1366                         if (value) {
1367                                 ERROR (dev, "deferred %s enable --> %d\n",
1368                                         data->name, value);
1369                                 continue;
1370                         }
1371                         data->state = STATE_EP_ENABLED;
1372                         wake_up (&data->wait);
1373                         DBG (dev, "woke up %s waiters\n", data->name);
1374                 }
1375
1376         /* host may have given up waiting for response.  we can miss control
1377          * requests handled lower down (device/endpoint status and features);
1378          * then ep0_{read,write} will report the wrong status. controller
1379          * driver will have aborted pending i/o.
1380          */
1381         } else if (dev->state == STATE_SETUP)
1382                 dev->setup_abort = 1;
1383
1384         req->buf = dev->rbuf;
1385         req->dma = DMA_ADDR_INVALID;
1386         req->context = NULL;
1387         value = -EOPNOTSUPP;
1388         switch (ctrl->bRequest) {
1389
1390         case USB_REQ_GET_DESCRIPTOR:
1391                 if (ctrl->bRequestType != USB_DIR_IN)
1392                         goto unrecognized;
1393                 switch (w_value >> 8) {
1394
1395                 case USB_DT_DEVICE:
1396                         value = min (w_length, (u16) sizeof *dev->dev);
1397                         req->buf = dev->dev;
1398                         break;
1399 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1400                 case USB_DT_DEVICE_QUALIFIER:
1401                         if (!dev->hs_config)
1402                                 break;
1403                         value = min (w_length, (u16)
1404                                 sizeof (struct usb_qualifier_descriptor));
1405                         make_qualifier (dev);
1406                         break;
1407                 case USB_DT_OTHER_SPEED_CONFIG:
1408                         // FALLTHROUGH
1409 #endif
1410                 case USB_DT_CONFIG:
1411                         value = config_buf (dev,
1412                                         w_value >> 8,
1413                                         w_value & 0xff);
1414                         if (value >= 0)
1415                                 value = min (w_length, (u16) value);
1416                         break;
1417                 case USB_DT_STRING:
1418                         goto unrecognized;
1419
1420                 default:                // all others are errors
1421                         break;
1422                 }
1423                 break;
1424
1425         /* currently one config, two speeds */
1426         case USB_REQ_SET_CONFIGURATION:
1427                 if (ctrl->bRequestType != 0)
1428                         break;
1429                 if (0 == (u8) w_value) {
1430                         value = 0;
1431                         dev->current_config = 0;
1432                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1433                         // user mode expected to disable endpoints
1434                 } else {
1435                         u8      config, power;
1436 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1437                         if (gadget->speed == USB_SPEED_HIGH) {
1438                                 config = dev->hs_config->bConfigurationValue;
1439                                 power = dev->hs_config->bMaxPower;
1440                         } else
1441 #endif
1442                         {
1443                                 config = dev->config->bConfigurationValue;
1444                                 power = dev->config->bMaxPower;
1445                         }
1446
1447                         if (config == (u8) w_value) {
1448                                 value = 0;
1449                                 dev->current_config = config;
1450                                 usb_gadget_vbus_draw(gadget, 2 * power);
1451                         }
1452                 }
1453
1454                 /* report SET_CONFIGURATION like any other control request,
1455                  * except that usermode may not stall this.  the next
1456                  * request mustn't be allowed start until this finishes:
1457                  * endpoints and threads set up, etc.
1458                  *
1459                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1460                  * has bad/racey automagic that prevents synchronizing here.
1461                  * even kernel mode drivers often miss them.
1462                  */
1463                 if (value == 0) {
1464                         INFO (dev, "configuration #%d\n", dev->current_config);
1465                         if (dev->usermode_setup) {
1466                                 dev->setup_can_stall = 0;
1467                                 goto delegate;
1468                         }
1469                 }
1470                 break;
1471
1472 #ifndef CONFIG_USB_GADGETFS_PXA2XX
1473         /* PXA automagically handles this request too */
1474         case USB_REQ_GET_CONFIGURATION:
1475                 if (ctrl->bRequestType != 0x80)
1476                         break;
1477                 *(u8 *)req->buf = dev->current_config;
1478                 value = min (w_length, (u16) 1);
1479                 break;
1480 #endif
1481
1482         default:
1483 unrecognized:
1484                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1485                         dev->usermode_setup ? "delegate" : "fail",
1486                         ctrl->bRequestType, ctrl->bRequest,
1487                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1488
1489                 /* if there's an ep0 reader, don't stall */
1490                 if (dev->usermode_setup) {
1491                         dev->setup_can_stall = 1;
1492 delegate:
1493                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1494                                                 ? 1 : 0;
1495                         dev->setup_wLength = w_length;
1496                         dev->setup_out_ready = 0;
1497                         dev->setup_out_error = 0;
1498                         value = 0;
1499
1500                         /* read DATA stage for OUT right away */
1501                         if (unlikely (!dev->setup_in && w_length)) {
1502                                 value = setup_req (gadget->ep0, dev->req,
1503                                                         w_length);
1504                                 if (value < 0)
1505                                         break;
1506                                 value = usb_ep_queue (gadget->ep0, dev->req,
1507                                                         GFP_ATOMIC);
1508                                 if (value < 0) {
1509                                         clean_req (gadget->ep0, dev->req);
1510                                         break;
1511                                 }
1512
1513                                 /* we can't currently stall these */
1514                                 dev->setup_can_stall = 0;
1515                         }
1516
1517                         /* state changes when reader collects event */
1518                         event = next_event (dev, GADGETFS_SETUP);
1519                         event->u.setup = *ctrl;
1520                         ep0_readable (dev);
1521                         spin_unlock (&dev->lock);
1522                         return 0;
1523                 }
1524         }
1525
1526         /* proceed with data transfer and status phases? */
1527         if (value >= 0 && dev->state != STATE_SETUP) {
1528                 req->length = value;
1529                 req->zero = value < w_length;
1530                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1531                 if (value < 0) {
1532                         DBG (dev, "ep_queue --> %d\n", value);
1533                         req->status = 0;
1534                 }
1535         }
1536
1537         /* device stalls when value < 0 */
1538         spin_unlock (&dev->lock);
1539         return value;
1540 }
1541
1542 static void destroy_ep_files (struct dev_data *dev)
1543 {
1544         struct list_head        *entry, *tmp;
1545
1546         DBG (dev, "%s %d\n", __FUNCTION__, dev->state);
1547
1548         /* dev->state must prevent interference */
1549 restart:
1550         spin_lock_irq (&dev->lock);
1551         list_for_each_safe (entry, tmp, &dev->epfiles) {
1552                 struct ep_data  *ep;
1553                 struct inode    *parent;
1554                 struct dentry   *dentry;
1555
1556                 /* break link to FS */
1557                 ep = list_entry (entry, struct ep_data, epfiles);
1558                 list_del_init (&ep->epfiles);
1559                 dentry = ep->dentry;
1560                 ep->dentry = NULL;
1561                 parent = dentry->d_parent->d_inode;
1562
1563                 /* break link to controller */
1564                 if (ep->state == STATE_EP_ENABLED)
1565                         (void) usb_ep_disable (ep->ep);
1566                 ep->state = STATE_EP_UNBOUND;
1567                 usb_ep_free_request (ep->ep, ep->req);
1568                 ep->ep = NULL;
1569                 wake_up (&ep->wait);
1570                 put_ep (ep);
1571
1572                 spin_unlock_irq (&dev->lock);
1573
1574                 /* break link to dcache */
1575                 mutex_lock (&parent->i_mutex);
1576                 d_delete (dentry);
1577                 dput (dentry);
1578                 mutex_unlock (&parent->i_mutex);
1579
1580                 /* fds may still be open */
1581                 goto restart;
1582         }
1583         spin_unlock_irq (&dev->lock);
1584 }
1585
1586
1587 static struct inode *
1588 gadgetfs_create_file (struct super_block *sb, char const *name,
1589                 void *data, const struct file_operations *fops,
1590                 struct dentry **dentry_p);
1591
1592 static int activate_ep_files (struct dev_data *dev)
1593 {
1594         struct usb_ep   *ep;
1595         struct ep_data  *data;
1596
1597         gadget_for_each_ep (ep, dev->gadget) {
1598
1599                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1600                 if (!data)
1601                         goto enomem0;
1602                 data->state = STATE_EP_DISABLED;
1603                 init_MUTEX (&data->lock);
1604                 init_waitqueue_head (&data->wait);
1605
1606                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1607                 atomic_set (&data->count, 1);
1608                 data->dev = dev;
1609                 get_dev (dev);
1610
1611                 data->ep = ep;
1612                 ep->driver_data = data;
1613
1614                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1615                 if (!data->req)
1616                         goto enomem1;
1617
1618                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1619                                 data, &ep_config_operations,
1620                                 &data->dentry);
1621                 if (!data->inode)
1622                         goto enomem2;
1623                 list_add_tail (&data->epfiles, &dev->epfiles);
1624         }
1625         return 0;
1626
1627 enomem2:
1628         usb_ep_free_request (ep, data->req);
1629 enomem1:
1630         put_dev (dev);
1631         kfree (data);
1632 enomem0:
1633         DBG (dev, "%s enomem\n", __FUNCTION__);
1634         destroy_ep_files (dev);
1635         return -ENOMEM;
1636 }
1637
1638 static void
1639 gadgetfs_unbind (struct usb_gadget *gadget)
1640 {
1641         struct dev_data         *dev = get_gadget_data (gadget);
1642
1643         DBG (dev, "%s\n", __FUNCTION__);
1644
1645         spin_lock_irq (&dev->lock);
1646         dev->state = STATE_DEV_UNBOUND;
1647         spin_unlock_irq (&dev->lock);
1648
1649         destroy_ep_files (dev);
1650         gadget->ep0->driver_data = NULL;
1651         set_gadget_data (gadget, NULL);
1652
1653         /* we've already been disconnected ... no i/o is active */
1654         if (dev->req)
1655                 usb_ep_free_request (gadget->ep0, dev->req);
1656         DBG (dev, "%s done\n", __FUNCTION__);
1657         put_dev (dev);
1658 }
1659
1660 static struct dev_data          *the_device;
1661
1662 static int
1663 gadgetfs_bind (struct usb_gadget *gadget)
1664 {
1665         struct dev_data         *dev = the_device;
1666
1667         if (!dev)
1668                 return -ESRCH;
1669         if (0 != strcmp (CHIP, gadget->name)) {
1670                 printk (KERN_ERR "%s expected %s controller not %s\n",
1671                         shortname, CHIP, gadget->name);
1672                 return -ENODEV;
1673         }
1674
1675         set_gadget_data (gadget, dev);
1676         dev->gadget = gadget;
1677         gadget->ep0->driver_data = dev;
1678         dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1679
1680         /* preallocate control response and buffer */
1681         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1682         if (!dev->req)
1683                 goto enomem;
1684         dev->req->context = NULL;
1685         dev->req->complete = epio_complete;
1686
1687         if (activate_ep_files (dev) < 0)
1688                 goto enomem;
1689
1690         INFO (dev, "bound to %s driver\n", gadget->name);
1691         dev->state = STATE_UNCONNECTED;
1692         get_dev (dev);
1693         return 0;
1694
1695 enomem:
1696         gadgetfs_unbind (gadget);
1697         return -ENOMEM;
1698 }
1699
1700 static void
1701 gadgetfs_disconnect (struct usb_gadget *gadget)
1702 {
1703         struct dev_data         *dev = get_gadget_data (gadget);
1704
1705         spin_lock (&dev->lock);
1706         if (dev->state == STATE_UNCONNECTED) {
1707                 DBG (dev, "already unconnected\n");
1708                 goto exit;
1709         }
1710         dev->state = STATE_UNCONNECTED;
1711
1712         INFO (dev, "disconnected\n");
1713         next_event (dev, GADGETFS_DISCONNECT);
1714         ep0_readable (dev);
1715 exit:
1716         spin_unlock (&dev->lock);
1717 }
1718
1719 static void
1720 gadgetfs_suspend (struct usb_gadget *gadget)
1721 {
1722         struct dev_data         *dev = get_gadget_data (gadget);
1723
1724         INFO (dev, "suspended from state %d\n", dev->state);
1725         spin_lock (&dev->lock);
1726         switch (dev->state) {
1727         case STATE_SETUP:               // VERY odd... host died??
1728         case STATE_CONNECTED:
1729         case STATE_UNCONNECTED:
1730                 next_event (dev, GADGETFS_SUSPEND);
1731                 ep0_readable (dev);
1732                 /* FALLTHROUGH */
1733         default:
1734                 break;
1735         }
1736         spin_unlock (&dev->lock);
1737 }
1738
1739 static struct usb_gadget_driver gadgetfs_driver = {
1740 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1741         .speed          = USB_SPEED_HIGH,
1742 #else
1743         .speed          = USB_SPEED_FULL,
1744 #endif
1745         .function       = (char *) driver_desc,
1746         .bind           = gadgetfs_bind,
1747         .unbind         = gadgetfs_unbind,
1748         .setup          = gadgetfs_setup,
1749         .disconnect     = gadgetfs_disconnect,
1750         .suspend        = gadgetfs_suspend,
1751
1752         .driver         = {
1753                 .name           = (char *) shortname,
1754         },
1755 };
1756
1757 /*----------------------------------------------------------------------*/
1758
1759 static void gadgetfs_nop(struct usb_gadget *arg) { }
1760
1761 static int gadgetfs_probe (struct usb_gadget *gadget)
1762 {
1763         CHIP = gadget->name;
1764         return -EISNAM;
1765 }
1766
1767 static struct usb_gadget_driver probe_driver = {
1768         .speed          = USB_SPEED_HIGH,
1769         .bind           = gadgetfs_probe,
1770         .unbind         = gadgetfs_nop,
1771         .setup          = (void *)gadgetfs_nop,
1772         .disconnect     = gadgetfs_nop,
1773         .driver         = {
1774                 .name           = "nop",
1775         },
1776 };
1777
1778
1779 /* DEVICE INITIALIZATION
1780  *
1781  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1782  *     status = write (fd, descriptors, sizeof descriptors)
1783  *
1784  * That write establishes the device configuration, so the kernel can
1785  * bind to the controller ... guaranteeing it can handle enumeration
1786  * at all necessary speeds.  Descriptor order is:
1787  *
1788  * . message tag (u32, host order) ... for now, must be zero; it
1789  *      would change to support features like multi-config devices
1790  * . full/low speed config ... all wTotalLength bytes (with interface,
1791  *      class, altsetting, endpoint, and other descriptors)
1792  * . high speed config ... all descriptors, for high speed operation;
1793  *      this one's optional except for high-speed hardware
1794  * . device descriptor
1795  *
1796  * Endpoints are not yet enabled. Drivers may want to immediately
1797  * initialize them, using the /dev/gadget/ep* files that are available
1798  * as soon as the kernel sees the configuration, or they can wait
1799  * until device configuration and interface altsetting changes create
1800  * the need to configure (or unconfigure) them.
1801  *
1802  * After initialization, the device stays active for as long as that
1803  * $CHIP file is open.  Events may then be read from that descriptor,
1804  * such as configuration notifications.  More complex drivers will handle
1805  * some control requests in user space.
1806  */
1807
1808 static int is_valid_config (struct usb_config_descriptor *config)
1809 {
1810         return config->bDescriptorType == USB_DT_CONFIG
1811                 && config->bLength == USB_DT_CONFIG_SIZE
1812                 && config->bConfigurationValue != 0
1813                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1814                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1815         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1816         /* FIXME check lengths: walk to end */
1817 }
1818
1819 static ssize_t
1820 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1821 {
1822         struct dev_data         *dev = fd->private_data;
1823         ssize_t                 value = len, length = len;
1824         unsigned                total;
1825         u32                     tag;
1826         char                    *kbuf;
1827
1828         if (dev->state != STATE_OPENED)
1829                 return -EEXIST;
1830
1831         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1832                 return -EINVAL;
1833
1834         /* we might need to change message format someday */
1835         if (copy_from_user (&tag, buf, 4))
1836                 return -EFAULT;
1837         if (tag != 0)
1838                 return -EINVAL;
1839         buf += 4;
1840         length -= 4;
1841
1842         kbuf = kmalloc (length, SLAB_KERNEL);
1843         if (!kbuf)
1844                 return -ENOMEM;
1845         if (copy_from_user (kbuf, buf, length)) {
1846                 kfree (kbuf);
1847                 return -EFAULT;
1848         }
1849
1850         spin_lock_irq (&dev->lock);
1851         value = -EINVAL;
1852         if (dev->buf)
1853                 goto fail;
1854         dev->buf = kbuf;
1855
1856         /* full or low speed config */
1857         dev->config = (void *) kbuf;
1858         total = le16_to_cpup (&dev->config->wTotalLength);
1859         if (!is_valid_config (dev->config) || total >= length)
1860                 goto fail;
1861         kbuf += total;
1862         length -= total;
1863
1864         /* optional high speed config */
1865         if (kbuf [1] == USB_DT_CONFIG) {
1866                 dev->hs_config = (void *) kbuf;
1867                 total = le16_to_cpup (&dev->hs_config->wTotalLength);
1868                 if (!is_valid_config (dev->hs_config) || total >= length)
1869                         goto fail;
1870                 kbuf += total;
1871                 length -= total;
1872         }
1873
1874         /* could support multiple configs, using another encoding! */
1875
1876         /* device descriptor (tweaked for paranoia) */
1877         if (length != USB_DT_DEVICE_SIZE)
1878                 goto fail;
1879         dev->dev = (void *)kbuf;
1880         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1881                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1882                         || dev->dev->bNumConfigurations != 1)
1883                 goto fail;
1884         dev->dev->bNumConfigurations = 1;
1885         dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200);
1886
1887         /* triggers gadgetfs_bind(); then we can enumerate. */
1888         spin_unlock_irq (&dev->lock);
1889         value = usb_gadget_register_driver (&gadgetfs_driver);
1890         if (value != 0) {
1891                 kfree (dev->buf);
1892                 dev->buf = NULL;
1893         } else {
1894                 /* at this point "good" hardware has for the first time
1895                  * let the USB the host see us.  alternatively, if users
1896                  * unplug/replug that will clear all the error state.
1897                  *
1898                  * note:  everything running before here was guaranteed
1899                  * to choke driver model style diagnostics.  from here
1900                  * on, they can work ... except in cleanup paths that
1901                  * kick in after the ep0 descriptor is closed.
1902                  */
1903                 fd->f_op = &ep0_io_operations;
1904                 value = len;
1905         }
1906         return value;
1907
1908 fail:
1909         spin_unlock_irq (&dev->lock);
1910         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __FUNCTION__, value, dev);
1911         kfree (dev->buf);
1912         dev->buf = NULL;
1913         return value;
1914 }
1915
1916 static int
1917 dev_open (struct inode *inode, struct file *fd)
1918 {
1919         struct dev_data         *dev = inode->i_private;
1920         int                     value = -EBUSY;
1921
1922         if (dev->state == STATE_DEV_DISABLED) {
1923                 dev->ev_next = 0;
1924                 dev->state = STATE_OPENED;
1925                 fd->private_data = dev;
1926                 get_dev (dev);
1927                 value = 0;
1928         }
1929         return value;
1930 }
1931
1932 static const struct file_operations dev_init_operations = {
1933         .owner =        THIS_MODULE,
1934         .llseek =       no_llseek,
1935
1936         .open =         dev_open,
1937         .write =        dev_config,
1938         .fasync =       ep0_fasync,
1939         .ioctl =        dev_ioctl,
1940         .release =      dev_release,
1941 };
1942
1943 /*----------------------------------------------------------------------*/
1944
1945 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1946  *
1947  * Mounting the filesystem creates a controller file, used first for
1948  * device configuration then later for event monitoring.
1949  */
1950
1951
1952 /* FIXME PAM etc could set this security policy without mount options
1953  * if epfiles inherited ownership and permissons from ep0 ...
1954  */
1955
1956 static unsigned default_uid;
1957 static unsigned default_gid;
1958 static unsigned default_perm = S_IRUSR | S_IWUSR;
1959
1960 module_param (default_uid, uint, 0644);
1961 module_param (default_gid, uint, 0644);
1962 module_param (default_perm, uint, 0644);
1963
1964
1965 static struct inode *
1966 gadgetfs_make_inode (struct super_block *sb,
1967                 void *data, const struct file_operations *fops,
1968                 int mode)
1969 {
1970         struct inode *inode = new_inode (sb);
1971
1972         if (inode) {
1973                 inode->i_mode = mode;
1974                 inode->i_uid = default_uid;
1975                 inode->i_gid = default_gid;
1976                 inode->i_blocks = 0;
1977                 inode->i_atime = inode->i_mtime = inode->i_ctime
1978                                 = CURRENT_TIME;
1979                 inode->i_private = data;
1980                 inode->i_fop = fops;
1981         }
1982         return inode;
1983 }
1984
1985 /* creates in fs root directory, so non-renamable and non-linkable.
1986  * so inode and dentry are paired, until device reconfig.
1987  */
1988 static struct inode *
1989 gadgetfs_create_file (struct super_block *sb, char const *name,
1990                 void *data, const struct file_operations *fops,
1991                 struct dentry **dentry_p)
1992 {
1993         struct dentry   *dentry;
1994         struct inode    *inode;
1995
1996         dentry = d_alloc_name(sb->s_root, name);
1997         if (!dentry)
1998                 return NULL;
1999
2000         inode = gadgetfs_make_inode (sb, data, fops,
2001                         S_IFREG | (default_perm & S_IRWXUGO));
2002         if (!inode) {
2003                 dput(dentry);
2004                 return NULL;
2005         }
2006         d_add (dentry, inode);
2007         *dentry_p = dentry;
2008         return inode;
2009 }
2010
2011 static struct super_operations gadget_fs_operations = {
2012         .statfs =       simple_statfs,
2013         .drop_inode =   generic_delete_inode,
2014 };
2015
2016 static int
2017 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2018 {
2019         struct inode    *inode;
2020         struct dentry   *d;
2021         struct dev_data *dev;
2022
2023         if (the_device)
2024                 return -ESRCH;
2025
2026         /* fake probe to determine $CHIP */
2027         (void) usb_gadget_register_driver (&probe_driver);
2028         if (!CHIP)
2029                 return -ENODEV;
2030
2031         /* superblock */
2032         sb->s_blocksize = PAGE_CACHE_SIZE;
2033         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2034         sb->s_magic = GADGETFS_MAGIC;
2035         sb->s_op = &gadget_fs_operations;
2036         sb->s_time_gran = 1;
2037
2038         /* root inode */
2039         inode = gadgetfs_make_inode (sb,
2040                         NULL, &simple_dir_operations,
2041                         S_IFDIR | S_IRUGO | S_IXUGO);
2042         if (!inode)
2043                 goto enomem0;
2044         inode->i_op = &simple_dir_inode_operations;
2045         if (!(d = d_alloc_root (inode)))
2046                 goto enomem1;
2047         sb->s_root = d;
2048
2049         /* the ep0 file is named after the controller we expect;
2050          * user mode code can use it for sanity checks, like we do.
2051          */
2052         dev = dev_new ();
2053         if (!dev)
2054                 goto enomem2;
2055
2056         dev->sb = sb;
2057         if (!gadgetfs_create_file (sb, CHIP,
2058                                 dev, &dev_init_operations,
2059                                 &dev->dentry))
2060                 goto enomem3;
2061
2062         /* other endpoint files are available after hardware setup,
2063          * from binding to a controller.
2064          */
2065         the_device = dev;
2066         return 0;
2067
2068 enomem3:
2069         put_dev (dev);
2070 enomem2:
2071         dput (d);
2072 enomem1:
2073         iput (inode);
2074 enomem0:
2075         return -ENOMEM;
2076 }
2077
2078 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2079 static int
2080 gadgetfs_get_sb (struct file_system_type *t, int flags,
2081                 const char *path, void *opts, struct vfsmount *mnt)
2082 {
2083         return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt);
2084 }
2085
2086 static void
2087 gadgetfs_kill_sb (struct super_block *sb)
2088 {
2089         kill_litter_super (sb);
2090         if (the_device) {
2091                 put_dev (the_device);
2092                 the_device = NULL;
2093         }
2094 }
2095
2096 /*----------------------------------------------------------------------*/
2097
2098 static struct file_system_type gadgetfs_type = {
2099         .owner          = THIS_MODULE,
2100         .name           = shortname,
2101         .get_sb         = gadgetfs_get_sb,
2102         .kill_sb        = gadgetfs_kill_sb,
2103 };
2104
2105 /*----------------------------------------------------------------------*/
2106
2107 static int __init init (void)
2108 {
2109         int status;
2110
2111         status = register_filesystem (&gadgetfs_type);
2112         if (status == 0)
2113                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2114                         shortname, driver_desc);
2115         return status;
2116 }
2117 module_init (init);
2118
2119 static void __exit cleanup (void)
2120 {
2121         pr_debug ("unregister %s\n", shortname);
2122         unregister_filesystem (&gadgetfs_type);
2123 }
2124 module_exit (cleanup);
2125