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