drivers/usb/gadget/inode.c

   1 /*
   2  * inode.c -- user mode filesystem api for usb gadget controllers
   3  *
   4  * Copyright (C) 2003-2004 David Brownell
   5  * Copyright (C) 2003 Agilent Technologies
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22
  23 /* #define VERBOSE_DEBUG */
  24
  25 #include <linux/init.h>
  26 #include <linux/module.h>
  27 #include <linux/fs.h>
  28 #include <linux/pagemap.h>
  29 #include <linux/uts.h>
  30 #include <linux/wait.h>
  31 #include <linux/compiler.h>
  32 #include <asm/uaccess.h>
  33 #include <linux/sched.h>
  34 #include <linux/slab.h>
  35 #include <linux/poll.h>
  36
  37 #include <linux/device.h>
  38 #include <linux/moduleparam.h>
  39
  40 #include <linux/usb/gadgetfs.h>
  41 #include <linux/usb/gadget.h>
  42
  43
  44 /*
  45  * The gadgetfs API maps each endpoint to a file descriptor so that you
  46  * can use standard synchronous read/write calls for I/O.  There's some
  47  * O_NONBLOCK and O_ASYNC/FASYNC style i/o support.  Example usermode
  48  * drivers show how this works in practice.  You can also use AIO to
  49  * eliminate I/O gaps between requests, to help when streaming data.
  50  *
  51  * Key parts that must be USB-specific are protocols defining how the
  52  * read/write operations relate to the hardware state machines.  There
  53  * are two types of files.  One type is for the device, implementing ep0.
  54  * The other type is for each IN or OUT endpoint.  In both cases, the
  55  * user mode driver must configure the hardware before using it.
  56  *
  57  * - First, dev_config() is called when /dev/gadget/$CHIP is configured
  58  *   (by writing configuration and device descriptors).  Afterwards it
  59  *   may serve as a source of device events, used to handle all control
  60  *   requests other than basic enumeration.
  61  *
  62  * - Then, after a SET_CONFIGURATION control request, ep_config() is
  63  *   called when each /dev/gadget/ep* file is configured (by writing
  64  *   endpoint descriptors).  Afterwards these files are used to write()
  65  *   IN data or to read() OUT data.  To halt the endpoint, a "wrong
  66  *   direction" request is issued (like reading an IN endpoint).
  67  *
  68  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
  69  * not possible on all hardware.  For example, precise fault handling with
  70  * respect to data left in endpoint fifos after aborted operations; or
  71  * selective clearing of endpoint halts, to implement SET_INTERFACE.
  72  */
  73
  74 #define DRIVER_DESC     "USB Gadget filesystem"
  75 #define DRIVER_VERSION  "24 Aug 2004"
  76
  77 static const char driver_desc [] = DRIVER_DESC;
  78 static const char shortname [] = "gadgetfs";
  79
  80 MODULE_DESCRIPTION (DRIVER_DESC);
  81 MODULE_AUTHOR ("David Brownell");
  82 MODULE_LICENSE ("GPL");
  83
  84
  85 /*----------------------------------------------------------------------*/
  86
  87 #define GADGETFS_MAGIC          0xaee71ee7
  88 #define DMA_ADDR_INVALID        (~(dma_addr_t)0)
  89
  90 /* /dev/gadget/$CHIP represents ep0 and the whole device */
  91 enum ep0_state {
  92         /* DISBLED is the initial state.
  93          */
  94         STATE_DEV_DISABLED = 0,
  95
  96         /* Only one open() of /dev/gadget/$CHIP; only one file tracks
  97          * ep0/device i/o modes and binding to the controller.  Driver
  98          * must always write descriptors to initialize the device, then
  99          * the device becomes UNCONNECTED until enumeration.
 100          */
 101         STATE_DEV_OPENED,
 102
 103         /* From then on, ep0 fd is in either of two basic modes:
 104          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
 105          * - SETUP: read/write will transfer control data and succeed;
 106          *   or if "wrong direction", performs protocol stall
 107          */
 108         STATE_DEV_UNCONNECTED,
 109         STATE_DEV_CONNECTED,
 110         STATE_DEV_SETUP,
 111
 112         /* UNBOUND means the driver closed ep0, so the device won't be
 113          * accessible again (DEV_DISABLED) until all fds are closed.
 114          */
 115         STATE_DEV_UNBOUND,
 116 };
 117
 118 /* enough for the whole queue: most events invalidate others */
 119 #define N_EVENT                 5
 120
 121 struct dev_data {
 122         spinlock_t                      lock;
 123         atomic_t                        count;
 124         enum ep0_state                  state;          /* P: lock */
 125         struct usb_gadgetfs_event       event [N_EVENT];
 126         unsigned                        ev_next;
 127         struct fasync_struct            *fasync;
 128         u8                              current_config;
 129
 130         /* drivers reading ep0 MUST handle control requests (SETUP)
 131          * reported that way; else the host will time out.
 132          */
 133         unsigned                        usermode_setup : 1,
 134                                         setup_in : 1,
 135                                         setup_can_stall : 1,
 136                                         setup_out_ready : 1,
 137                                         setup_out_error : 1,
 138                                         setup_abort : 1;
 139         unsigned                        setup_wLength;
 140
 141         /* the rest is basically write-once */
 142         struct usb_config_descriptor    *config, *hs_config;
 143         struct usb_device_descriptor    *dev;
 144         struct usb_request              *req;
 145         struct usb_gadget               *gadget;
 146         struct list_head                epfiles;
 147         void                            *buf;
 148         wait_queue_head_t               wait;
 149         struct super_block              *sb;
 150         struct dentry                   *dentry;
 151
 152         /* except this scratch i/o buffer for ep0 */
 153         u8                              rbuf [256];
 154 };
 155
 156 static inline void get_dev (struct dev_data *data)
 157 {
 158         atomic_inc (&data->count);
 159 }
 160
 161 static void put_dev (struct dev_data *data)
 162 {
 163         if (likely (!atomic_dec_and_test (&data->count)))
 164                 return;
 165         /* needs no more cleanup */
 166         BUG_ON (waitqueue_active (&data->wait));
 167         kfree (data);
 168 }
 169
 170 static struct dev_data *dev_new (void)
 171 {
 172         struct dev_data         *dev;
 173
 174         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 175         if (!dev)
 176                 return NULL;
 177         dev->state = STATE_DEV_DISABLED;
 178         atomic_set (&dev->count, 1);
 179         spin_lock_init (&dev->lock);
 180         INIT_LIST_HEAD (&dev->epfiles);
 181         init_waitqueue_head (&dev->wait);
 182         return dev;
 183 }
 184
 185 /*----------------------------------------------------------------------*/
 186
 187 /* other /dev/gadget/$ENDPOINT files represent endpoints */
 188 enum ep_state {
 189         STATE_EP_DISABLED = 0,
 190         STATE_EP_READY,
 191         STATE_EP_ENABLED,
 192         STATE_EP_UNBOUND,
 193 };
 194
 195 struct ep_data {
 196         struct mutex                    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         kfree (data);
 226 }
 227
 228 /*----------------------------------------------------------------------*/
 229
 230 /* most "how to use the hardware" policy choices are in userspace:
 231  * mapping endpoint roles (which the driver needs) to the capabilities
 232  * which the usb controller has.  most of those capabilities are exposed
 233  * implicitly, starting with the driver name and then endpoint names.
 234  */
 235
 236 static const char *CHIP;
 237
 238 /*----------------------------------------------------------------------*/
 239
 240 /* NOTE:  don't use dev_printk calls before binding to the gadget
 241  * at the end of ep0 configuration, or after unbind.
 242  */
 243
 244 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
 245 #define xprintk(d,level,fmt,args...) \
 246         printk(level "%s: " fmt , shortname , ## args)
 247
 248 #ifdef DEBUG
 249 #define DBG(dev,fmt,args...) \
 250         xprintk(dev , KERN_DEBUG , fmt , ## args)
 251 #else
 252 #define DBG(dev,fmt,args...) \
 253         do { } while (0)
 254 #endif /* DEBUG */
 255
 256 #ifdef VERBOSE_DEBUG
 257 #define VDEBUG  DBG
 258 #else
 259 #define VDEBUG(dev,fmt,args...) \
 260         do { } while (0)
 261 #endif /* DEBUG */
 262
 263 #define ERROR(dev,fmt,args...) \
 264         xprintk(dev , KERN_ERR , fmt , ## args)
 265 #define INFO(dev,fmt,args...) \
 266         xprintk(dev , KERN_INFO , fmt , ## args)
 267
 268
 269 /*----------------------------------------------------------------------*/
 270
 271 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 272  *
 273  * After opening, configure non-control endpoints.  Then use normal
 274  * stream read() and write() requests; and maybe ioctl() to get more
 275  * precise FIFO status when recovering from cancellation.
 276  */
 277
 278 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 279 {
 280         struct ep_data  *epdata = ep->driver_data;
 281
 282         if (!req->context)
 283                 return;
 284         if (req->status)
 285                 epdata->status = req->status;
 286         else
 287                 epdata->status = req->actual;
 288         complete ((struct completion *)req->context);
 289 }
 290
 291 /* tasklock endpoint, returning when it's connected.
 292  * still need dev->lock to use epdata->ep.
 293  */
 294 static int
 295 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
 296 {
 297         int     val;
 298
 299         if (f_flags & O_NONBLOCK) {
 300                 if (!mutex_trylock(&epdata->lock))
 301                         goto nonblock;
 302                 if (epdata->state != STATE_EP_ENABLED) {
 303                         mutex_unlock(&epdata->lock);
 304 nonblock:
 305                         val = -EAGAIN;
 306                 } else
 307                         val = 0;
 308                 return val;
 309         }
 310
 311         val = mutex_lock_interruptible(&epdata->lock);
 312         if (val < 0)
 313                 return val;
 314
 315         switch (epdata->state) {
 316         case STATE_EP_ENABLED:
 317                 break;
 318         // case STATE_EP_DISABLED:              /* "can't happen" */
 319         // case STATE_EP_READY:                 /* "can't happen" */
 320         default:                                /* error! */
 321                 pr_debug ("%s: ep %p not available, state %d\n",
 322                                 shortname, epdata, epdata->state);
 323                 // FALLTHROUGH
 324         case STATE_EP_UNBOUND:                  /* clean disconnect */
 325                 val = -ENODEV;
 326                 mutex_unlock(&epdata->lock);
 327         }
 328         return val;
 329 }
 330
 331 static ssize_t
 332 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 333 {
 334         DECLARE_COMPLETION_ONSTACK (done);
 335         int value;
 336
 337         spin_lock_irq (&epdata->dev->lock);
 338         if (likely (epdata->ep != NULL)) {
 339                 struct usb_request      *req = epdata->req;
 340
 341                 req->context = &done;
 342                 req->complete = epio_complete;
 343                 req->buf = buf;
 344                 req->length = len;
 345                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 346         } else
 347                 value = -ENODEV;
 348         spin_unlock_irq (&epdata->dev->lock);
 349
 350         if (likely (value == 0)) {
 351                 value = wait_event_interruptible (done.wait, done.done);
 352                 if (value != 0) {
 353                         spin_lock_irq (&epdata->dev->lock);
 354                         if (likely (epdata->ep != NULL)) {
 355                                 DBG (epdata->dev, "%s i/o interrupted\n",
 356                                                 epdata->name);
 357                                 usb_ep_dequeue (epdata->ep, epdata->req);
 358                                 spin_unlock_irq (&epdata->dev->lock);
 359
 360                                 wait_event (done.wait, done.done);
 361                                 if (epdata->status == -ECONNRESET)
 362                                         epdata->status = -EINTR;
 363                         } else {
 364                                 spin_unlock_irq (&epdata->dev->lock);
 365
 366                                 DBG (epdata->dev, "endpoint gone\n");
 367                                 epdata->status = -ENODEV;
 368                         }
 369                 }
 370                 return epdata->status;
 371         }
 372         return value;
 373 }
 374
 375
 376 /* handle a synchronous OUT bulk/intr/iso transfer */
 377 static ssize_t
 378 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 379 {
 380         struct ep_data          *data = fd->private_data;
 381         void                    *kbuf;
 382         ssize_t                 value;
 383
 384         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 385                 return value;
 386
 387         /* halt any endpoint by doing a "wrong direction" i/o call */
 388         if (usb_endpoint_dir_in(&data->desc)) {
 389                 if (usb_endpoint_xfer_isoc(&data->desc)) {
 390                         mutex_unlock(&data->lock);
 391                         return -EINVAL;
 392                 }
 393                 DBG (data->dev, "%s halt\n", data->name);
 394                 spin_lock_irq (&data->dev->lock);
 395                 if (likely (data->ep != NULL))
 396                         usb_ep_set_halt (data->ep);
 397                 spin_unlock_irq (&data->dev->lock);
 398                 mutex_unlock(&data->lock);
 399                 return -EBADMSG;
 400         }
 401
 402         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
 403
 404         value = -ENOMEM;
 405         kbuf = kmalloc (len, GFP_KERNEL);
 406         if (unlikely (!kbuf))
 407                 goto free1;
 408
 409         value = ep_io (data, kbuf, len);
 410         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
 411                 data->name, len, (int) value);
 412         if (value >= 0 && copy_to_user (buf, kbuf, value))
 413                 value = -EFAULT;
 414
 415 free1:
 416         mutex_unlock(&data->lock);
 417         kfree (kbuf);
 418         return value;
 419 }
 420
 421 /* handle a synchronous IN bulk/intr/iso transfer */
 422 static ssize_t
 423 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 424 {
 425         struct ep_data          *data = fd->private_data;
 426         void                    *kbuf;
 427         ssize_t                 value;
 428
 429         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 430                 return value;
 431
 432         /* halt any endpoint by doing a "wrong direction" i/o call */
 433         if (!usb_endpoint_dir_in(&data->desc)) {
 434                 if (usb_endpoint_xfer_isoc(&data->desc)) {
 435                         mutex_unlock(&data->lock);
 436                         return -EINVAL;
 437                 }
 438                 DBG (data->dev, "%s halt\n", data->name);
 439                 spin_lock_irq (&data->dev->lock);
 440                 if (likely (data->ep != NULL))
 441                         usb_ep_set_halt (data->ep);
 442                 spin_unlock_irq (&data->dev->lock);
 443                 mutex_unlock(&data->lock);
 444                 return -EBADMSG;
 445         }
 446
 447         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
 448
 449         value = -ENOMEM;
 450         kbuf = kmalloc (len, GFP_KERNEL);
 451         if (!kbuf)
 452                 goto free1;
 453         if (copy_from_user (kbuf, buf, len)) {
 454                 value = -EFAULT;
 455                 goto free1;
 456         }
 457
 458         value = ep_io (data, kbuf, len);
 459         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
 460                 data->name, len, (int) value);
 461 free1:
 462         mutex_unlock(&data->lock);
 463         kfree (kbuf);
 464         return value;
 465 }
 466
 467 static int
 468 ep_release (struct inode *inode, struct file *fd)
 469 {
 470         struct ep_data          *data = fd->private_data;
 471         int value;
 472
 473         value = mutex_lock_interruptible(&data->lock);
 474         if (value < 0)
 475                 return value;
 476
 477         /* clean up if this can be reopened */
 478         if (data->state != STATE_EP_UNBOUND) {
 479                 data->state = STATE_EP_DISABLED;
 480                 data->desc.bDescriptorType = 0;
 481                 data->hs_desc.bDescriptorType = 0;
 482                 usb_ep_disable(data->ep);
 483         }
 484         mutex_unlock(&data->lock);
 485         put_ep (data);
 486         return 0;
 487 }
 488
 489 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
 490 {
 491         struct ep_data          *data = fd->private_data;
 492         int                     status;
 493
 494         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 495                 return status;
 496
 497         spin_lock_irq (&data->dev->lock);
 498         if (likely (data->ep != NULL)) {
 499                 switch (code) {
 500                 case GADGETFS_FIFO_STATUS:
 501                         status = usb_ep_fifo_status (data->ep);
 502                         break;
 503                 case GADGETFS_FIFO_FLUSH:
 504                         usb_ep_fifo_flush (data->ep);
 505                         break;
 506                 case GADGETFS_CLEAR_HALT:
 507                         status = usb_ep_clear_halt (data->ep);
 508                         break;
 509                 default:
 510                         status = -ENOTTY;
 511                 }
 512         } else
 513                 status = -ENODEV;
 514         spin_unlock_irq (&data->dev->lock);
 515         mutex_unlock(&data->lock);
 516         return status;
 517 }
 518
 519 /*----------------------------------------------------------------------*/
 520
 521 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 522
 523 struct kiocb_priv {
 524         struct usb_request      *req;
 525         struct ep_data          *epdata;
 526         void                    *buf;
 527         const struct iovec      *iv;
 528         unsigned long           nr_segs;
 529         unsigned                actual;
 530 };
 531
 532 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
 533 {
 534         struct kiocb_priv       *priv = iocb->private;
 535         struct ep_data          *epdata;
 536         int                     value;
 537
 538         local_irq_disable();
 539         epdata = priv->epdata;
 540         // spin_lock(&epdata->dev->lock);
 541         kiocbSetCancelled(iocb);
 542         if (likely(epdata && epdata->ep && priv->req))
 543                 value = usb_ep_dequeue (epdata->ep, priv->req);
 544         else
 545                 value = -EINVAL;
 546         // spin_unlock(&epdata->dev->lock);
 547         local_irq_enable();
 548
 549         aio_put_req(iocb);
 550         return value;
 551 }
 552
 553 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
 554 {
 555         struct kiocb_priv       *priv = iocb->private;
 556         ssize_t                 len, total;
 557         void                    *to_copy;
 558         int                     i;
 559
 560         /* we "retry" to get the right mm context for this: */
 561
 562         /* copy stuff into user buffers */
 563         total = priv->actual;
 564         len = 0;
 565         to_copy = priv->buf;
 566         for (i=0; i < priv->nr_segs; i++) {
 567                 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
 568
 569                 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
 570                         if (len == 0)
 571                                 len = -EFAULT;
 572                         break;
 573                 }
 574
 575                 total -= this;
 576                 len += this;
 577                 to_copy += this;
 578                 if (total == 0)
 579                         break;
 580         }
 581         kfree(priv->buf);
 582         kfree(priv);
 583         return len;
 584 }
 585
 586 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 587 {
 588         struct kiocb            *iocb = req->context;
 589         struct kiocb_priv       *priv = iocb->private;
 590         struct ep_data          *epdata = priv->epdata;
 591
 592         /* lock against disconnect (and ideally, cancel) */
 593         spin_lock(&epdata->dev->lock);
 594         priv->req = NULL;
 595         priv->epdata = NULL;
 596
 597         /* if this was a write or a read returning no data then we
 598          * don't need to copy anything to userspace, so we can
 599          * complete the aio request immediately.
 600          */
 601         if (priv->iv == NULL || unlikely(req->actual == 0)) {
 602                 kfree(req->buf);
 603                 kfree(priv);
 604                 iocb->private = NULL;
 605                 /* aio_complete() reports bytes-transferred _and_ faults */
 606                 aio_complete(iocb, req->actual ? req->actual : req->status,
 607                                 req->status);
 608         } else {
 609                 /* retry() won't report both; so we hide some faults */
 610                 if (unlikely(0 != req->status))
 611                         DBG(epdata->dev, "%s fault %d len %d\n",
 612                                 ep->name, req->status, req->actual);
 613
 614                 priv->buf = req->buf;
 615                 priv->actual = req->actual;
 616                 kick_iocb(iocb);
 617         }
 618         spin_unlock(&epdata->dev->lock);
 619
 620         usb_ep_free_request(ep, req);
 621         put_ep(epdata);
 622 }
 623
 624 static ssize_t
 625 ep_aio_rwtail(
 626         struct kiocb    *iocb,
 627         char            *buf,
 628         size_t          len,
 629         struct ep_data  *epdata,
 630         const struct iovec *iv,
 631         unsigned long   nr_segs
 632 )
 633 {
 634         struct kiocb_priv       *priv;
 635         struct usb_request      *req;
 636         ssize_t                 value;
 637
 638         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 639         if (!priv) {
 640                 value = -ENOMEM;
 641 fail:
 642                 kfree(buf);
 643                 return value;
 644         }
 645         iocb->private = priv;
 646         priv->iv = iv;
 647         priv->nr_segs = nr_segs;
 648
 649         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 650         if (unlikely(value < 0)) {
 651                 kfree(priv);
 652                 goto fail;
 653         }
 654
 655         iocb->ki_cancel = ep_aio_cancel;
 656         get_ep(epdata);
 657         priv->epdata = epdata;
 658         priv->actual = 0;
 659
 660         /* each kiocb is coupled to one usb_request, but we can't
 661          * allocate or submit those if the host disconnected.
 662          */
 663         spin_lock_irq(&epdata->dev->lock);
 664         if (likely(epdata->ep)) {
 665                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 666                 if (likely(req)) {
 667                         priv->req = req;
 668                         req->buf = buf;
 669                         req->length = len;
 670                         req->complete = ep_aio_complete;
 671                         req->context = iocb;
 672                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 673                         if (unlikely(0 != value))
 674                                 usb_ep_free_request(epdata->ep, req);
 675                 } else
 676                         value = -EAGAIN;
 677         } else
 678                 value = -ENODEV;
 679         spin_unlock_irq(&epdata->dev->lock);
 680
 681         mutex_unlock(&epdata->lock);
 682
 683         if (unlikely(value)) {
 684                 kfree(priv);
 685                 put_ep(epdata);
 686         } else
 687                 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
 688         return value;
 689 }
 690
 691 static ssize_t
 692 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
 693                 unsigned long nr_segs, loff_t o)
 694 {
 695         struct ep_data          *epdata = iocb->ki_filp->private_data;
 696         char                    *buf;
 697
 698         if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
 699                 return -EINVAL;
 700
 701         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 702         if (unlikely(!buf))
 703                 return -ENOMEM;
 704
 705         iocb->ki_retry = ep_aio_read_retry;
 706         return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
 707 }
 708
 709 static ssize_t
 710 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
 711                 unsigned long nr_segs, loff_t o)
 712 {
 713         struct ep_data          *epdata = iocb->ki_filp->private_data;
 714         char                    *buf;
 715         size_t                  len = 0;
 716         int                     i = 0;
 717
 718         if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
 719                 return -EINVAL;
 720
 721         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 722         if (unlikely(!buf))
 723                 return -ENOMEM;
 724
 725         for (i=0; i < nr_segs; i++) {
 726                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
 727                                 iov[i].iov_len) != 0)) {
 728                         kfree(buf);
 729                         return -EFAULT;
 730                 }
 731                 len += iov[i].iov_len;
 732         }
 733         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
 734 }
 735
 736 /*----------------------------------------------------------------------*/
 737
 738 /* used after endpoint configuration */
 739 static const struct file_operations ep_io_operations = {
 740         .owner =        THIS_MODULE,
 741         .llseek =       no_llseek,
 742
 743         .read =         ep_read,
 744         .write =        ep_write,
 745         .unlocked_ioctl = ep_ioctl,
 746         .release =      ep_release,
 747
 748         .aio_read =     ep_aio_read,
 749         .aio_write =    ep_aio_write,
 750 };
 751
 752 /* ENDPOINT INITIALIZATION
 753  *
 754  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 755  *     status = write (fd, descriptors, sizeof descriptors)
 756  *
 757  * That write establishes the endpoint configuration, configuring
 758  * the controller to process bulk, interrupt, or isochronous transfers
 759  * at the right maxpacket size, and so on.
 760  *
 761  * The descriptors are message type 1, identified by a host order u32
 762  * at the beginning of what's written.  Descriptor order is: full/low
 763  * speed descriptor, then optional high speed descriptor.
 764  */
 765 static ssize_t
 766 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 767 {
 768         struct ep_data          *data = fd->private_data;
 769         struct usb_ep           *ep;
 770         u32                     tag;
 771         int                     value, length = len;
 772
 773         value = mutex_lock_interruptible(&data->lock);
 774         if (value < 0)
 775                 return value;
 776
 777         if (data->state != STATE_EP_READY) {
 778                 value = -EL2HLT;
 779                 goto fail;
 780         }
 781
 782         value = len;
 783         if (len < USB_DT_ENDPOINT_SIZE + 4)
 784                 goto fail0;
 785
 786         /* we might need to change message format someday */
 787         if (copy_from_user (&tag, buf, 4)) {
 788                 goto fail1;
 789         }
 790         if (tag != 1) {
 791                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 792                 goto fail0;
 793         }
 794         buf += 4;
 795         len -= 4;
 796
 797         /* NOTE:  audio endpoint extensions not accepted here;
 798          * just don't include the extra bytes.
 799          */
 800
 801         /* full/low speed descriptor, then high speed */
 802         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 803                 goto fail1;
 804         }
 805         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 806                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 807                 goto fail0;
 808         if (len != USB_DT_ENDPOINT_SIZE) {
 809                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 810                         goto fail0;
 811                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 812                                         USB_DT_ENDPOINT_SIZE)) {
 813                         goto fail1;
 814                 }
 815                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 816                                 || data->hs_desc.bDescriptorType
 817                                         != USB_DT_ENDPOINT) {
 818                         DBG(data->dev, "config %s, bad hs length or type\n",
 819                                         data->name);
 820                         goto fail0;
 821                 }
 822         }
 823
 824         spin_lock_irq (&data->dev->lock);
 825         if (data->dev->state == STATE_DEV_UNBOUND) {
 826                 value = -ENOENT;
 827                 goto gone;
 828         } else if ((ep = data->ep) == NULL) {
 829                 value = -ENODEV;
 830                 goto gone;
 831         }
 832         switch (data->dev->gadget->speed) {
 833         case USB_SPEED_LOW:
 834         case USB_SPEED_FULL:
 835                 value = usb_ep_enable (ep, &data->desc);
 836                 if (value == 0)
 837                         data->state = STATE_EP_ENABLED;
 838                 break;
 839 #ifdef  CONFIG_USB_GADGET_DUALSPEED
 840         case USB_SPEED_HIGH:
 841                 /* fails if caller didn't provide that descriptor... */
 842                 value = usb_ep_enable (ep, &data->hs_desc);
 843                 if (value == 0)
 844                         data->state = STATE_EP_ENABLED;
 845                 break;
 846 #endif
 847         default:
 848                 DBG(data->dev, "unconnected, %s init abandoned\n",
 849                                 data->name);
 850                 value = -EINVAL;
 851         }
 852         if (value == 0) {
 853                 fd->f_op = &ep_io_operations;
 854                 value = length;
 855         }
 856 gone:
 857         spin_unlock_irq (&data->dev->lock);
 858         if (value < 0) {
 859 fail:
 860                 data->desc.bDescriptorType = 0;
 861                 data->hs_desc.bDescriptorType = 0;
 862         }
 863         mutex_unlock(&data->lock);
 864         return value;
 865 fail0:
 866         value = -EINVAL;
 867         goto fail;
 868 fail1:
 869         value = -EFAULT;
 870         goto fail;
 871 }
 872
 873 static int
 874 ep_open (struct inode *inode, struct file *fd)
 875 {
 876         struct ep_data          *data = inode->i_private;
 877         int                     value = -EBUSY;
 878
 879         if (mutex_lock_interruptible(&data->lock) != 0)
 880                 return -EINTR;
 881         spin_lock_irq (&data->dev->lock);
 882         if (data->dev->state == STATE_DEV_UNBOUND)
 883                 value = -ENOENT;
 884         else if (data->state == STATE_EP_DISABLED) {
 885                 value = 0;
 886                 data->state = STATE_EP_READY;
 887                 get_ep (data);
 888                 fd->private_data = data;
 889                 VDEBUG (data->dev, "%s ready\n", data->name);
 890         } else
 891                 DBG (data->dev, "%s state %d\n",
 892                         data->name, data->state);
 893         spin_unlock_irq (&data->dev->lock);
 894         mutex_unlock(&data->lock);
 895         return value;
 896 }
 897
 898 /* used before endpoint configuration */
 899 static const struct file_operations ep_config_operations = {
 900         .owner =        THIS_MODULE,
 901         .llseek =       no_llseek,
 902
 903         .open =         ep_open,
 904         .write =        ep_config,
 905         .release =      ep_release,
 906 };
 907
 908 /*----------------------------------------------------------------------*/
 909
 910 /* EP0 IMPLEMENTATION can be partly in userspace.
 911  *
 912  * Drivers that use this facility receive various events, including
 913  * control requests the kernel doesn't handle.  Drivers that don't
 914  * use this facility may be too simple-minded for real applications.
 915  */
 916
 917 static inline void ep0_readable (struct dev_data *dev)
 918 {
 919         wake_up (&dev->wait);
 920         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 921 }
 922
 923 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 924 {
 925         struct dev_data         *dev = ep->driver_data;
 926
 927         if (req->buf != dev->rbuf) {
 928                 kfree(req->buf);
 929                 req->buf = dev->rbuf;
 930                 req->dma = DMA_ADDR_INVALID;
 931         }
 932         req->complete = epio_complete;
 933         dev->setup_out_ready = 0;
 934 }
 935
 936 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 937 {
 938         struct dev_data         *dev = ep->driver_data;
 939         unsigned long           flags;
 940         int                     free = 1;
 941
 942         /* for control OUT, data must still get to userspace */
 943         spin_lock_irqsave(&dev->lock, flags);
 944         if (!dev->setup_in) {
 945                 dev->setup_out_error = (req->status != 0);
 946                 if (!dev->setup_out_error)
 947                         free = 0;
 948                 dev->setup_out_ready = 1;
 949                 ep0_readable (dev);
 950         }
 951
 952         /* clean up as appropriate */
 953         if (free && req->buf != &dev->rbuf)
 954                 clean_req (ep, req);
 955         req->complete = epio_complete;
 956         spin_unlock_irqrestore(&dev->lock, flags);
 957 }
 958
 959 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 960 {
 961         struct dev_data *dev = ep->driver_data;
 962
 963         if (dev->setup_out_ready) {
 964                 DBG (dev, "ep0 request busy!\n");
 965                 return -EBUSY;
 966         }
 967         if (len > sizeof (dev->rbuf))
 968                 req->buf = kmalloc(len, GFP_ATOMIC);
 969         if (req->buf == NULL) {
 970                 req->buf = dev->rbuf;
 971                 return -ENOMEM;
 972         }
 973         req->complete = ep0_complete;
 974         req->length = len;
 975         req->zero = 0;
 976         return 0;
 977 }
 978
 979 static ssize_t
 980 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 981 {
 982         struct dev_data                 *dev = fd->private_data;
 983         ssize_t                         retval;
 984         enum ep0_state                  state;
 985
 986         spin_lock_irq (&dev->lock);
 987
 988         /* report fd mode change before acting on it */
 989         if (dev->setup_abort) {
 990                 dev->setup_abort = 0;
 991                 retval = -EIDRM;
 992                 goto done;
 993         }
 994
 995         /* control DATA stage */
 996         if ((state = dev->state) == STATE_DEV_SETUP) {
 997
 998                 if (dev->setup_in) {            /* stall IN */
 999                         VDEBUG(dev, "ep0in stall\n");
1000                         (void) usb_ep_set_halt (dev->gadget->ep0);
1001                         retval = -EL2HLT;
1002                         dev->state = STATE_DEV_CONNECTED;
1003
1004                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
1005                         struct usb_ep           *ep = dev->gadget->ep0;
1006                         struct usb_request      *req = dev->req;
1007
1008                         if ((retval = setup_req (ep, req, 0)) == 0)
1009                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1010                         dev->state = STATE_DEV_CONNECTED;
1011
1012                         /* assume that was SET_CONFIGURATION */
1013                         if (dev->current_config) {
1014                                 unsigned power;
1015
1016                                 if (gadget_is_dualspeed(dev->gadget)
1017                                                 && (dev->gadget->speed
1018                                                         == USB_SPEED_HIGH))
1019                                         power = dev->hs_config->bMaxPower;
1020                                 else
1021                                         power = dev->config->bMaxPower;
1022                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1023                         }
1024
1025                 } else {                        /* collect OUT data */
1026                         if ((fd->f_flags & O_NONBLOCK) != 0
1027                                         && !dev->setup_out_ready) {
1028                                 retval = -EAGAIN;
1029                                 goto done;
1030                         }
1031                         spin_unlock_irq (&dev->lock);
1032                         retval = wait_event_interruptible (dev->wait,
1033                                         dev->setup_out_ready != 0);
1034
1035                         /* FIXME state could change from under us */
1036                         spin_lock_irq (&dev->lock);
1037                         if (retval)
1038                                 goto done;
1039
1040                         if (dev->state != STATE_DEV_SETUP) {
1041                                 retval = -ECANCELED;
1042                                 goto done;
1043                         }
1044                         dev->state = STATE_DEV_CONNECTED;
1045
1046                         if (dev->setup_out_error)
1047                                 retval = -EIO;
1048                         else {
1049                                 len = min (len, (size_t)dev->req->actual);
1050 // FIXME don't call this with the spinlock held ...
1051                                 if (copy_to_user (buf, dev->req->buf, len))
1052                                         retval = -EFAULT;
1053                                 clean_req (dev->gadget->ep0, dev->req);
1054                                 /* NOTE userspace can't yet choose to stall */
1055                         }
1056                 }
1057                 goto done;
1058         }
1059
1060         /* else normal: return event data */
1061         if (len < sizeof dev->event [0]) {
1062                 retval = -EINVAL;
1063                 goto done;
1064         }
1065         len -= len % sizeof (struct usb_gadgetfs_event);
1066         dev->usermode_setup = 1;
1067
1068 scan:
1069         /* return queued events right away */
1070         if (dev->ev_next != 0) {
1071                 unsigned                i, n;
1072
1073                 n = len / sizeof (struct usb_gadgetfs_event);
1074                 if (dev->ev_next < n)
1075                         n = dev->ev_next;
1076
1077                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1078                 for (i = 0; i < n; i++) {
1079                         if (dev->event [i].type == GADGETFS_SETUP) {
1080                                 dev->state = STATE_DEV_SETUP;
1081                                 n = i + 1;
1082                                 break;
1083                         }
1084                 }
1085                 spin_unlock_irq (&dev->lock);
1086                 len = n * sizeof (struct usb_gadgetfs_event);
1087                 if (copy_to_user (buf, &dev->event, len))
1088                         retval = -EFAULT;
1089                 else
1090                         retval = len;
1091                 if (len > 0) {
1092                         /* NOTE this doesn't guard against broken drivers;
1093                          * concurrent ep0 readers may lose events.
1094                          */
1095                         spin_lock_irq (&dev->lock);
1096                         if (dev->ev_next > n) {
1097                                 memmove(&dev->event[0], &dev->event[n],
1098                                         sizeof (struct usb_gadgetfs_event)
1099                                                 * (dev->ev_next - n));
1100                         }
1101                         dev->ev_next -= n;
1102                         spin_unlock_irq (&dev->lock);
1103                 }
1104                 return retval;
1105         }
1106         if (fd->f_flags & O_NONBLOCK) {
1107                 retval = -EAGAIN;
1108                 goto done;
1109         }
1110
1111         switch (state) {
1112         default:
1113                 DBG (dev, "fail %s, state %d\n", __func__, state);
1114                 retval = -ESRCH;
1115                 break;
1116         case STATE_DEV_UNCONNECTED:
1117         case STATE_DEV_CONNECTED:
1118                 spin_unlock_irq (&dev->lock);
1119                 DBG (dev, "%s wait\n", __func__);
1120
1121                 /* wait for events */
1122                 retval = wait_event_interruptible (dev->wait,
1123                                 dev->ev_next != 0);
1124                 if (retval < 0)
1125                         return retval;
1126                 spin_lock_irq (&dev->lock);
1127                 goto scan;
1128         }
1129
1130 done:
1131         spin_unlock_irq (&dev->lock);
1132         return retval;
1133 }
1134
1135 static struct usb_gadgetfs_event *
1136 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1137 {
1138         struct usb_gadgetfs_event       *event;
1139         unsigned                        i;
1140
1141         switch (type) {
1142         /* these events purge the queue */
1143         case GADGETFS_DISCONNECT:
1144                 if (dev->state == STATE_DEV_SETUP)
1145                         dev->setup_abort = 1;
1146                 // FALL THROUGH
1147         case GADGETFS_CONNECT:
1148                 dev->ev_next = 0;
1149                 break;
1150         case GADGETFS_SETUP:            /* previous request timed out */
1151         case GADGETFS_SUSPEND:          /* same effect */
1152                 /* these events can't be repeated */
1153                 for (i = 0; i != dev->ev_next; i++) {
1154                         if (dev->event [i].type != type)
1155                                 continue;
1156                         DBG(dev, "discard old event[%d] %d\n", i, type);
1157                         dev->ev_next--;
1158                         if (i == dev->ev_next)
1159                                 break;
1160                         /* indices start at zero, for simplicity */
1161                         memmove (&dev->event [i], &dev->event [i + 1],
1162                                 sizeof (struct usb_gadgetfs_event)
1163                                         * (dev->ev_next - i));
1164                 }
1165                 break;
1166         default:
1167                 BUG ();
1168         }
1169         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1170         event = &dev->event [dev->ev_next++];
1171         BUG_ON (dev->ev_next > N_EVENT);
1172         memset (event, 0, sizeof *event);
1173         event->type = type;
1174         return event;
1175 }
1176
1177 static ssize_t
1178 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1179 {
1180         struct dev_data         *dev = fd->private_data;
1181         ssize_t                 retval = -ESRCH;
1182
1183         spin_lock_irq (&dev->lock);
1184
1185         /* report fd mode change before acting on it */
1186         if (dev->setup_abort) {
1187                 dev->setup_abort = 0;
1188                 retval = -EIDRM;
1189
1190         /* data and/or status stage for control request */
1191         } else if (dev->state == STATE_DEV_SETUP) {
1192
1193                 /* IN DATA+STATUS caller makes len <= wLength */
1194                 if (dev->setup_in) {
1195                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1196                         if (retval == 0) {
1197                                 dev->state = STATE_DEV_CONNECTED;
1198                                 spin_unlock_irq (&dev->lock);
1199                                 if (copy_from_user (dev->req->buf, buf, len))
1200                                         retval = -EFAULT;
1201                                 else {
1202                                         if (len < dev->setup_wLength)
1203                                                 dev->req->zero = 1;
1204                                         retval = usb_ep_queue (
1205                                                 dev->gadget->ep0, dev->req,
1206                                                 GFP_KERNEL);
1207                                 }
1208                                 if (retval < 0) {
1209                                         spin_lock_irq (&dev->lock);
1210                                         clean_req (dev->gadget->ep0, dev->req);
1211                                         spin_unlock_irq (&dev->lock);
1212                                 } else
1213                                         retval = len;
1214
1215                                 return retval;
1216                         }
1217
1218                 /* can stall some OUT transfers */
1219                 } else if (dev->setup_can_stall) {
1220                         VDEBUG(dev, "ep0out stall\n");
1221                         (void) usb_ep_set_halt (dev->gadget->ep0);
1222                         retval = -EL2HLT;
1223                         dev->state = STATE_DEV_CONNECTED;
1224                 } else {
1225                         DBG(dev, "bogus ep0out stall!\n");
1226                 }
1227         } else
1228                 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1229
1230         spin_unlock_irq (&dev->lock);
1231         return retval;
1232 }
1233
1234 static int
1235 ep0_fasync (int f, struct file *fd, int on)
1236 {
1237         struct dev_data         *dev = fd->private_data;
1238         // caller must F_SETOWN before signal delivery happens
1239         VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1240         return fasync_helper (f, fd, on, &dev->fasync);
1241 }
1242
1243 static struct usb_gadget_driver gadgetfs_driver;
1244
1245 static int
1246 dev_release (struct inode *inode, struct file *fd)
1247 {
1248         struct dev_data         *dev = fd->private_data;
1249
1250         /* closing ep0 === shutdown all */
1251
1252         usb_gadget_unregister_driver (&gadgetfs_driver);
1253
1254         /* at this point "good" hardware has disconnected the
1255          * device from USB; the host won't see it any more.
1256          * alternatively, all host requests will time out.
1257          */
1258
1259         kfree (dev->buf);
1260         dev->buf = NULL;
1261         put_dev (dev);
1262
1263         /* other endpoints were all decoupled from this device */
1264         spin_lock_irq(&dev->lock);
1265         dev->state = STATE_DEV_DISABLED;
1266         spin_unlock_irq(&dev->lock);
1267         return 0;
1268 }
1269
1270 static unsigned int
1271 ep0_poll (struct file *fd, poll_table *wait)
1272 {
1273        struct dev_data         *dev = fd->private_data;
1274        int                     mask = 0;
1275
1276        poll_wait(fd, &dev->wait, wait);
1277
1278        spin_lock_irq (&dev->lock);
1279
1280        /* report fd mode change before acting on it */
1281        if (dev->setup_abort) {
1282                dev->setup_abort = 0;
1283                mask = POLLHUP;
1284                goto out;
1285        }
1286
1287        if (dev->state == STATE_DEV_SETUP) {
1288                if (dev->setup_in || dev->setup_can_stall)
1289                        mask = POLLOUT;
1290        } else {
1291                if (dev->ev_next != 0)
1292                        mask = POLLIN;
1293        }
1294 out:
1295        spin_unlock_irq(&dev->lock);
1296        return mask;
1297 }
1298
1299 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1300 {
1301         struct dev_data         *dev = fd->private_data;
1302         struct usb_gadget       *gadget = dev->gadget;
1303         long ret = -ENOTTY;
1304
1305         if (gadget->ops->ioctl)
1306                 ret = gadget->ops->ioctl (gadget, code, value);
1307
1308         return ret;
1309 }
1310
1311 /* used after device configuration */
1312 static const struct file_operations ep0_io_operations = {
1313         .owner =        THIS_MODULE,
1314         .llseek =       no_llseek,
1315
1316         .read =         ep0_read,
1317         .write =        ep0_write,
1318         .fasync =       ep0_fasync,
1319         .poll =         ep0_poll,
1320         .unlocked_ioctl =       dev_ioctl,
1321         .release =      dev_release,
1322 };
1323
1324 /*----------------------------------------------------------------------*/
1325
1326 /* The in-kernel gadget driver handles most ep0 issues, in particular
1327  * enumerating the single configuration (as provided from user space).
1328  *
1329  * Unrecognized ep0 requests may be handled in user space.
1330  */
1331
1332 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1333 static void make_qualifier (struct dev_data *dev)
1334 {
1335         struct usb_qualifier_descriptor         qual;
1336         struct usb_device_descriptor            *desc;
1337
1338         qual.bLength = sizeof qual;
1339         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1340         qual.bcdUSB = cpu_to_le16 (0x0200);
1341
1342         desc = dev->dev;
1343         qual.bDeviceClass = desc->bDeviceClass;
1344         qual.bDeviceSubClass = desc->bDeviceSubClass;
1345         qual.bDeviceProtocol = desc->bDeviceProtocol;
1346
1347         /* assumes ep0 uses the same value for both speeds ... */
1348         qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
1349
1350         qual.bNumConfigurations = 1;
1351         qual.bRESERVED = 0;
1352
1353         memcpy (dev->rbuf, &qual, sizeof qual);
1354 }
1355 #endif
1356
1357 static int
1358 config_buf (struct dev_data *dev, u8 type, unsigned index)
1359 {
1360         int             len;
1361         int             hs = 0;
1362
1363         /* only one configuration */
1364         if (index > 0)
1365                 return -EINVAL;
1366
1367         if (gadget_is_dualspeed(dev->gadget)) {
1368                 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1369                 if (type == USB_DT_OTHER_SPEED_CONFIG)
1370                         hs = !hs;
1371         }
1372         if (hs) {
1373                 dev->req->buf = dev->hs_config;
1374                 len = le16_to_cpu(dev->hs_config->wTotalLength);
1375         } else {
1376                 dev->req->buf = dev->config;
1377                 len = le16_to_cpu(dev->config->wTotalLength);
1378         }
1379         ((u8 *)dev->req->buf) [1] = type;
1380         return len;
1381 }
1382
1383 static int
1384 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1385 {
1386         struct dev_data                 *dev = get_gadget_data (gadget);
1387         struct usb_request              *req = dev->req;
1388         int                             value = -EOPNOTSUPP;
1389         struct usb_gadgetfs_event       *event;
1390         u16                             w_value = le16_to_cpu(ctrl->wValue);
1391         u16                             w_length = le16_to_cpu(ctrl->wLength);
1392
1393         spin_lock (&dev->lock);
1394         dev->setup_abort = 0;
1395         if (dev->state == STATE_DEV_UNCONNECTED) {
1396                 if (gadget_is_dualspeed(gadget)
1397                                 && gadget->speed == USB_SPEED_HIGH
1398                                 && dev->hs_config == NULL) {
1399                         spin_unlock(&dev->lock);
1400                         ERROR (dev, "no high speed config??\n");
1401                         return -EINVAL;
1402                 }
1403
1404                 dev->state = STATE_DEV_CONNECTED;
1405                 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1406
1407                 INFO (dev, "connected\n");
1408                 event = next_event (dev, GADGETFS_CONNECT);
1409                 event->u.speed = gadget->speed;
1410                 ep0_readable (dev);
1411
1412         /* host may have given up waiting for response.  we can miss control
1413          * requests handled lower down (device/endpoint status and features);
1414          * then ep0_{read,write} will report the wrong status. controller
1415          * driver will have aborted pending i/o.
1416          */
1417         } else if (dev->state == STATE_DEV_SETUP)
1418                 dev->setup_abort = 1;
1419
1420         req->buf = dev->rbuf;
1421         req->dma = DMA_ADDR_INVALID;
1422         req->context = NULL;
1423         value = -EOPNOTSUPP;
1424         switch (ctrl->bRequest) {
1425
1426         case USB_REQ_GET_DESCRIPTOR:
1427                 if (ctrl->bRequestType != USB_DIR_IN)
1428                         goto unrecognized;
1429                 switch (w_value >> 8) {
1430
1431                 case USB_DT_DEVICE:
1432                         value = min (w_length, (u16) sizeof *dev->dev);
1433                         req->buf = dev->dev;
1434                         break;
1435 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1436                 case USB_DT_DEVICE_QUALIFIER:
1437                         if (!dev->hs_config)
1438                                 break;
1439                         value = min (w_length, (u16)
1440                                 sizeof (struct usb_qualifier_descriptor));
1441                         make_qualifier (dev);
1442                         break;
1443                 case USB_DT_OTHER_SPEED_CONFIG:
1444                         // FALLTHROUGH
1445 #endif
1446                 case USB_DT_CONFIG:
1447                         value = config_buf (dev,
1448                                         w_value >> 8,
1449                                         w_value & 0xff);
1450                         if (value >= 0)
1451                                 value = min (w_length, (u16) value);
1452                         break;
1453                 case USB_DT_STRING:
1454                         goto unrecognized;
1455
1456                 default:                // all others are errors
1457                         break;
1458                 }
1459                 break;
1460
1461         /* currently one config, two speeds */
1462         case USB_REQ_SET_CONFIGURATION:
1463                 if (ctrl->bRequestType != 0)
1464                         goto unrecognized;
1465                 if (0 == (u8) w_value) {
1466                         value = 0;
1467                         dev->current_config = 0;
1468                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1469                         // user mode expected to disable endpoints
1470                 } else {
1471                         u8      config, power;
1472
1473                         if (gadget_is_dualspeed(gadget)
1474                                         && gadget->speed == USB_SPEED_HIGH) {
1475                                 config = dev->hs_config->bConfigurationValue;
1476                                 power = dev->hs_config->bMaxPower;
1477                         } else {
1478                                 config = dev->config->bConfigurationValue;
1479                                 power = dev->config->bMaxPower;
1480                         }
1481
1482                         if (config == (u8) w_value) {
1483                                 value = 0;
1484                                 dev->current_config = config;
1485                                 usb_gadget_vbus_draw(gadget, 2 * power);
1486                         }
1487                 }
1488
1489                 /* report SET_CONFIGURATION like any other control request,
1490                  * except that usermode may not stall this.  the next
1491                  * request mustn't be allowed start until this finishes:
1492                  * endpoints and threads set up, etc.
1493                  *
1494                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1495                  * has bad/racey automagic that prevents synchronizing here.
1496                  * even kernel mode drivers often miss them.
1497                  */
1498                 if (value == 0) {
1499                         INFO (dev, "configuration #%d\n", dev->current_config);
1500                         if (dev->usermode_setup) {
1501                                 dev->setup_can_stall = 0;
1502                                 goto delegate;
1503                         }
1504                 }
1505                 break;
1506
1507 #ifndef CONFIG_USB_GADGET_PXA25X
1508         /* PXA automagically handles this request too */
1509         case USB_REQ_GET_CONFIGURATION:
1510                 if (ctrl->bRequestType != 0x80)
1511                         goto unrecognized;
1512                 *(u8 *)req->buf = dev->current_config;
1513                 value = min (w_length, (u16) 1);
1514                 break;
1515 #endif
1516
1517         default:
1518 unrecognized:
1519                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1520                         dev->usermode_setup ? "delegate" : "fail",
1521                         ctrl->bRequestType, ctrl->bRequest,
1522                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1523
1524                 /* if there's an ep0 reader, don't stall */
1525                 if (dev->usermode_setup) {
1526                         dev->setup_can_stall = 1;
1527 delegate:
1528                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1529                                                 ? 1 : 0;
1530                         dev->setup_wLength = w_length;
1531                         dev->setup_out_ready = 0;
1532                         dev->setup_out_error = 0;
1533                         value = 0;
1534
1535                         /* read DATA stage for OUT right away */
1536                         if (unlikely (!dev->setup_in && w_length)) {
1537                                 value = setup_req (gadget->ep0, dev->req,
1538                                                         w_length);
1539                                 if (value < 0)
1540                                         break;
1541                                 value = usb_ep_queue (gadget->ep0, dev->req,
1542                                                         GFP_ATOMIC);
1543                                 if (value < 0) {
1544                                         clean_req (gadget->ep0, dev->req);
1545                                         break;
1546                                 }
1547
1548                                 /* we can't currently stall these */
1549                                 dev->setup_can_stall = 0;
1550                         }
1551
1552                         /* state changes when reader collects event */
1553                         event = next_event (dev, GADGETFS_SETUP);
1554                         event->u.setup = *ctrl;
1555                         ep0_readable (dev);
1556                         spin_unlock (&dev->lock);
1557                         return 0;
1558                 }
1559         }
1560
1561         /* proceed with data transfer and status phases? */
1562         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1563                 req->length = value;
1564                 req->zero = value < w_length;
1565                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1566                 if (value < 0) {
1567                         DBG (dev, "ep_queue --> %d\n", value);
1568                         req->status = 0;
1569                 }
1570         }
1571
1572         /* device stalls when value < 0 */
1573         spin_unlock (&dev->lock);
1574         return value;
1575 }
1576
1577 static void destroy_ep_files (struct dev_data *dev)
1578 {
1579         struct list_head        *entry, *tmp;
1580
1581         DBG (dev, "%s %d\n", __func__, dev->state);
1582
1583         /* dev->state must prevent interference */
1584 restart:
1585         spin_lock_irq (&dev->lock);
1586         list_for_each_safe (entry, tmp, &dev->epfiles) {
1587                 struct ep_data  *ep;
1588                 struct inode    *parent;
1589                 struct dentry   *dentry;
1590
1591                 /* break link to FS */
1592                 ep = list_entry (entry, struct ep_data, epfiles);
1593                 list_del_init (&ep->epfiles);
1594                 dentry = ep->dentry;
1595                 ep->dentry = NULL;
1596                 parent = dentry->d_parent->d_inode;
1597
1598                 /* break link to controller */
1599                 if (ep->state == STATE_EP_ENABLED)
1600                         (void) usb_ep_disable (ep->ep);
1601                 ep->state = STATE_EP_UNBOUND;
1602                 usb_ep_free_request (ep->ep, ep->req);
1603                 ep->ep = NULL;
1604                 wake_up (&ep->wait);
1605                 put_ep (ep);
1606
1607                 spin_unlock_irq (&dev->lock);
1608
1609                 /* break link to dcache */
1610                 mutex_lock (&parent->i_mutex);
1611                 d_delete (dentry);
1612                 dput (dentry);
1613                 mutex_unlock (&parent->i_mutex);
1614
1615                 /* fds may still be open */
1616                 goto restart;
1617         }
1618         spin_unlock_irq (&dev->lock);
1619 }
1620
1621
1622 static struct inode *
1623 gadgetfs_create_file (struct super_block *sb, char const *name,
1624                 void *data, const struct file_operations *fops,
1625                 struct dentry **dentry_p);
1626
1627 static int activate_ep_files (struct dev_data *dev)
1628 {
1629         struct usb_ep   *ep;
1630         struct ep_data  *data;
1631
1632         gadget_for_each_ep (ep, dev->gadget) {
1633
1634                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1635                 if (!data)
1636                         goto enomem0;
1637                 data->state = STATE_EP_DISABLED;
1638                 mutex_init(&data->lock);
1639                 init_waitqueue_head (&data->wait);
1640
1641                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1642                 atomic_set (&data->count, 1);
1643                 data->dev = dev;
1644                 get_dev (dev);
1645
1646                 data->ep = ep;
1647                 ep->driver_data = data;
1648
1649                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1650                 if (!data->req)
1651                         goto enomem1;
1652
1653                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1654                                 data, &ep_config_operations,
1655                                 &data->dentry);
1656                 if (!data->inode)
1657                         goto enomem2;
1658                 list_add_tail (&data->epfiles, &dev->epfiles);
1659         }
1660         return 0;
1661
1662 enomem2:
1663         usb_ep_free_request (ep, data->req);
1664 enomem1:
1665         put_dev (dev);
1666         kfree (data);
1667 enomem0:
1668         DBG (dev, "%s enomem\n", __func__);
1669         destroy_ep_files (dev);
1670         return -ENOMEM;
1671 }
1672
1673 static void
1674 gadgetfs_unbind (struct usb_gadget *gadget)
1675 {
1676         struct dev_data         *dev = get_gadget_data (gadget);
1677
1678         DBG (dev, "%s\n", __func__);
1679
1680         spin_lock_irq (&dev->lock);
1681         dev->state = STATE_DEV_UNBOUND;
1682         spin_unlock_irq (&dev->lock);
1683
1684         destroy_ep_files (dev);
1685         gadget->ep0->driver_data = NULL;
1686         set_gadget_data (gadget, NULL);
1687
1688         /* we've already been disconnected ... no i/o is active */
1689         if (dev->req)
1690                 usb_ep_free_request (gadget->ep0, dev->req);
1691         DBG (dev, "%s done\n", __func__);
1692         put_dev (dev);
1693 }
1694
1695 static struct dev_data          *the_device;
1696
1697 static int
1698 gadgetfs_bind (struct usb_gadget *gadget)
1699 {
1700         struct dev_data         *dev = the_device;
1701
1702         if (!dev)
1703                 return -ESRCH;
1704         if (0 != strcmp (CHIP, gadget->name)) {
1705                 pr_err("%s expected %s controller not %s\n",
1706                         shortname, CHIP, gadget->name);
1707                 return -ENODEV;
1708         }
1709
1710         set_gadget_data (gadget, dev);
1711         dev->gadget = gadget;
1712         gadget->ep0->driver_data = dev;
1713         dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1714
1715         /* preallocate control response and buffer */
1716         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1717         if (!dev->req)
1718                 goto enomem;
1719         dev->req->context = NULL;
1720         dev->req->complete = epio_complete;
1721
1722         if (activate_ep_files (dev) < 0)
1723                 goto enomem;
1724
1725         INFO (dev, "bound to %s driver\n", gadget->name);
1726         spin_lock_irq(&dev->lock);
1727         dev->state = STATE_DEV_UNCONNECTED;
1728         spin_unlock_irq(&dev->lock);
1729         get_dev (dev);
1730         return 0;
1731
1732 enomem:
1733         gadgetfs_unbind (gadget);
1734         return -ENOMEM;
1735 }
1736
1737 static void
1738 gadgetfs_disconnect (struct usb_gadget *gadget)
1739 {
1740         struct dev_data         *dev = get_gadget_data (gadget);
1741
1742         spin_lock (&dev->lock);
1743         if (dev->state == STATE_DEV_UNCONNECTED)
1744                 goto exit;
1745         dev->state = STATE_DEV_UNCONNECTED;
1746
1747         INFO (dev, "disconnected\n");
1748         next_event (dev, GADGETFS_DISCONNECT);
1749         ep0_readable (dev);
1750 exit:
1751         spin_unlock (&dev->lock);
1752 }
1753
1754 static void
1755 gadgetfs_suspend (struct usb_gadget *gadget)
1756 {
1757         struct dev_data         *dev = get_gadget_data (gadget);
1758
1759         INFO (dev, "suspended from state %d\n", dev->state);
1760         spin_lock (&dev->lock);
1761         switch (dev->state) {
1762         case STATE_DEV_SETUP:           // VERY odd... host died??
1763         case STATE_DEV_CONNECTED:
1764         case STATE_DEV_UNCONNECTED:
1765                 next_event (dev, GADGETFS_SUSPEND);
1766                 ep0_readable (dev);
1767                 /* FALLTHROUGH */
1768         default:
1769                 break;
1770         }
1771         spin_unlock (&dev->lock);
1772 }
1773
1774 static struct usb_gadget_driver gadgetfs_driver = {
1775 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1776         .speed          = USB_SPEED_HIGH,
1777 #else
1778         .speed          = USB_SPEED_FULL,
1779 #endif
1780         .function       = (char *) driver_desc,
1781         .unbind         = gadgetfs_unbind,
1782         .setup          = gadgetfs_setup,
1783         .disconnect     = gadgetfs_disconnect,
1784         .suspend        = gadgetfs_suspend,
1785
1786         .driver = {
1787                 .name           = (char *) shortname,
1788         },
1789 };
1790
1791 /*----------------------------------------------------------------------*/
1792
1793 static void gadgetfs_nop(struct usb_gadget *arg) { }
1794
1795 static int gadgetfs_probe (struct usb_gadget *gadget)
1796 {
1797         CHIP = gadget->name;
1798         return -EISNAM;
1799 }
1800
1801 static struct usb_gadget_driver probe_driver = {
1802         .speed          = USB_SPEED_HIGH,
1803         .unbind         = gadgetfs_nop,
1804         .setup          = (void *)gadgetfs_nop,
1805         .disconnect     = gadgetfs_nop,
1806         .driver = {
1807                 .name           = "nop",
1808         },
1809 };
1810
1811
1812 /* DEVICE INITIALIZATION
1813  *
1814  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1815  *     status = write (fd, descriptors, sizeof descriptors)
1816  *
1817  * That write establishes the device configuration, so the kernel can
1818  * bind to the controller ... guaranteeing it can handle enumeration
1819  * at all necessary speeds.  Descriptor order is:
1820  *
1821  * . message tag (u32, host order) ... for now, must be zero; it
1822  *      would change to support features like multi-config devices
1823  * . full/low speed config ... all wTotalLength bytes (with interface,
1824  *      class, altsetting, endpoint, and other descriptors)
1825  * . high speed config ... all descriptors, for high speed operation;
1826  *      this one's optional except for high-speed hardware
1827  * . device descriptor
1828  *
1829  * Endpoints are not yet enabled. Drivers must wait until device
1830  * configuration and interface altsetting changes create
1831  * the need to configure (or unconfigure) them.
1832  *
1833  * After initialization, the device stays active for as long as that
1834  * $CHIP file is open.  Events must then be read from that descriptor,
1835  * such as configuration notifications.
1836  */
1837
1838 static int is_valid_config (struct usb_config_descriptor *config)
1839 {
1840         return config->bDescriptorType == USB_DT_CONFIG
1841                 && config->bLength == USB_DT_CONFIG_SIZE
1842                 && config->bConfigurationValue != 0
1843                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1844                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1845         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1846         /* FIXME check lengths: walk to end */
1847 }
1848
1849 static ssize_t
1850 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1851 {
1852         struct dev_data         *dev = fd->private_data;
1853         ssize_t                 value = len, length = len;
1854         unsigned                total;
1855         u32                     tag;
1856         char                    *kbuf;
1857
1858         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1859                 return -EINVAL;
1860
1861         /* we might need to change message format someday */
1862         if (copy_from_user (&tag, buf, 4))
1863                 return -EFAULT;
1864         if (tag != 0)
1865                 return -EINVAL;
1866         buf += 4;
1867         length -= 4;
1868
1869         kbuf = memdup_user(buf, length);
1870         if (IS_ERR(kbuf))
1871                 return PTR_ERR(kbuf);
1872
1873         spin_lock_irq (&dev->lock);
1874         value = -EINVAL;
1875         if (dev->buf)
1876                 goto fail;
1877         dev->buf = kbuf;
1878
1879         /* full or low speed config */
1880         dev->config = (void *) kbuf;
1881         total = le16_to_cpu(dev->config->wTotalLength);
1882         if (!is_valid_config (dev->config) || total >= length)
1883                 goto fail;
1884         kbuf += total;
1885         length -= total;
1886
1887         /* optional high speed config */
1888         if (kbuf [1] == USB_DT_CONFIG) {
1889                 dev->hs_config = (void *) kbuf;
1890                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1891                 if (!is_valid_config (dev->hs_config) || total >= length)
1892                         goto fail;
1893                 kbuf += total;
1894                 length -= total;
1895         }
1896
1897         /* could support multiple configs, using another encoding! */
1898
1899         /* device descriptor (tweaked for paranoia) */
1900         if (length != USB_DT_DEVICE_SIZE)
1901                 goto fail;
1902         dev->dev = (void *)kbuf;
1903         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1904                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1905                         || dev->dev->bNumConfigurations != 1)
1906                 goto fail;
1907         dev->dev->bNumConfigurations = 1;
1908         dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1909
1910         /* triggers gadgetfs_bind(); then we can enumerate. */
1911         spin_unlock_irq (&dev->lock);
1912         value = usb_gadget_probe_driver(&gadgetfs_driver, gadgetfs_bind);
1913         if (value != 0) {
1914                 kfree (dev->buf);
1915                 dev->buf = NULL;
1916         } else {
1917                 /* at this point "good" hardware has for the first time
1918                  * let the USB the host see us.  alternatively, if users
1919                  * unplug/replug that will clear all the error state.
1920                  *
1921                  * note:  everything running before here was guaranteed
1922                  * to choke driver model style diagnostics.  from here
1923                  * on, they can work ... except in cleanup paths that
1924                  * kick in after the ep0 descriptor is closed.
1925                  */
1926                 fd->f_op = &ep0_io_operations;
1927                 value = len;
1928         }
1929         return value;
1930
1931 fail:
1932         spin_unlock_irq (&dev->lock);
1933         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1934         kfree (dev->buf);
1935         dev->buf = NULL;
1936         return value;
1937 }
1938
1939 static int
1940 dev_open (struct inode *inode, struct file *fd)
1941 {
1942         struct dev_data         *dev = inode->i_private;
1943         int                     value = -EBUSY;
1944
1945         spin_lock_irq(&dev->lock);
1946         if (dev->state == STATE_DEV_DISABLED) {
1947                 dev->ev_next = 0;
1948                 dev->state = STATE_DEV_OPENED;
1949                 fd->private_data = dev;
1950                 get_dev (dev);
1951                 value = 0;
1952         }
1953         spin_unlock_irq(&dev->lock);
1954         return value;
1955 }
1956
1957 static const struct file_operations dev_init_operations = {
1958         .owner =        THIS_MODULE,
1959         .llseek =       no_llseek,
1960
1961         .open =         dev_open,
1962         .write =        dev_config,
1963         .fasync =       ep0_fasync,
1964         .unlocked_ioctl = dev_ioctl,
1965         .release =      dev_release,
1966 };
1967
1968 /*----------------------------------------------------------------------*/
1969
1970 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1971  *
1972  * Mounting the filesystem creates a controller file, used first for
1973  * device configuration then later for event monitoring.
1974  */
1975
1976
1977 /* FIXME PAM etc could set this security policy without mount options
1978  * if epfiles inherited ownership and permissons from ep0 ...
1979  */
1980
1981 static unsigned default_uid;
1982 static unsigned default_gid;
1983 static unsigned default_perm = S_IRUSR | S_IWUSR;
1984
1985 module_param (default_uid, uint, 0644);
1986 module_param (default_gid, uint, 0644);
1987 module_param (default_perm, uint, 0644);
1988
1989
1990 static struct inode *
1991 gadgetfs_make_inode (struct super_block *sb,
1992                 void *data, const struct file_operations *fops,
1993                 int mode)
1994 {
1995         struct inode *inode = new_inode (sb);
1996
1997         if (inode) {
1998                 inode->i_ino = get_next_ino();
1999                 inode->i_mode = mode;
2000                 inode->i_uid = default_uid;
2001                 inode->i_gid = default_gid;
2002                 inode->i_atime = inode->i_mtime = inode->i_ctime
2003                                 = CURRENT_TIME;
2004                 inode->i_private = data;
2005                 inode->i_fop = fops;
2006         }
2007         return inode;
2008 }
2009
2010 /* creates in fs root directory, so non-renamable and non-linkable.
2011  * so inode and dentry are paired, until device reconfig.
2012  */
2013 static struct inode *
2014 gadgetfs_create_file (struct super_block *sb, char const *name,
2015                 void *data, const struct file_operations *fops,
2016                 struct dentry **dentry_p)
2017 {
2018         struct dentry   *dentry;
2019         struct inode    *inode;
2020
2021         dentry = d_alloc_name(sb->s_root, name);
2022         if (!dentry)
2023                 return NULL;
2024
2025         inode = gadgetfs_make_inode (sb, data, fops,
2026                         S_IFREG | (default_perm & S_IRWXUGO));
2027         if (!inode) {
2028                 dput(dentry);
2029                 return NULL;
2030         }
2031         d_add (dentry, inode);
2032         *dentry_p = dentry;
2033         return inode;
2034 }
2035
2036 static const struct super_operations gadget_fs_operations = {
2037         .statfs =       simple_statfs,
2038         .drop_inode =   generic_delete_inode,
2039 };
2040
2041 static int
2042 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2043 {
2044         struct inode    *inode;
2045         struct dentry   *d;
2046         struct dev_data *dev;
2047
2048         if (the_device)
2049                 return -ESRCH;
2050
2051         /* fake probe to determine $CHIP */
2052         (void) usb_gadget_probe_driver(&probe_driver, gadgetfs_probe);
2053         if (!CHIP)
2054                 return -ENODEV;
2055
2056         /* superblock */
2057         sb->s_blocksize = PAGE_CACHE_SIZE;
2058         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2059         sb->s_magic = GADGETFS_MAGIC;
2060         sb->s_op = &gadget_fs_operations;
2061         sb->s_time_gran = 1;
2062
2063         /* root inode */
2064         inode = gadgetfs_make_inode (sb,
2065                         NULL, &simple_dir_operations,
2066                         S_IFDIR | S_IRUGO | S_IXUGO);
2067         if (!inode)
2068                 goto enomem0;
2069         inode->i_op = &simple_dir_inode_operations;
2070         if (!(d = d_alloc_root (inode)))
2071                 goto enomem1;
2072         sb->s_root = d;
2073
2074         /* the ep0 file is named after the controller we expect;
2075          * user mode code can use it for sanity checks, like we do.
2076          */
2077         dev = dev_new ();
2078         if (!dev)
2079                 goto enomem2;
2080
2081         dev->sb = sb;
2082         if (!gadgetfs_create_file (sb, CHIP,
2083                                 dev, &dev_init_operations,
2084                                 &dev->dentry))
2085                 goto enomem3;
2086
2087         /* other endpoint files are available after hardware setup,
2088          * from binding to a controller.
2089          */
2090         the_device = dev;
2091         return 0;
2092
2093 enomem3:
2094         put_dev (dev);
2095 enomem2:
2096         dput (d);
2097 enomem1:
2098         iput (inode);
2099 enomem0:
2100         return -ENOMEM;
2101 }
2102
2103 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2104 static struct dentry *
2105 gadgetfs_mount (struct file_system_type *t, int flags,
2106                 const char *path, void *opts)
2107 {
2108         return mount_single (t, flags, opts, gadgetfs_fill_super);
2109 }
2110
2111 static void
2112 gadgetfs_kill_sb (struct super_block *sb)
2113 {
2114         kill_litter_super (sb);
2115         if (the_device) {
2116                 put_dev (the_device);
2117                 the_device = NULL;
2118         }
2119 }
2120
2121 /*----------------------------------------------------------------------*/
2122
2123 static struct file_system_type gadgetfs_type = {
2124         .owner          = THIS_MODULE,
2125         .name           = shortname,
2126         .mount          = gadgetfs_mount,
2127         .kill_sb        = gadgetfs_kill_sb,
2128 };
2129
2130 /*----------------------------------------------------------------------*/
2131
2132 static int __init init (void)
2133 {
2134         int status;
2135
2136         status = register_filesystem (&gadgetfs_type);
2137         if (status == 0)
2138                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2139                         shortname, driver_desc);
2140         return status;
2141 }
2142 module_init (init);
2143
2144 static void __exit cleanup (void)
2145 {
2146         pr_debug ("unregister %s\n", shortname);
2147         unregister_filesystem (&gadgetfs_type);
2148 }
2149 module_exit (cleanup);
2150