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/slab.h>
  34 #include <linux/poll.h>
  35 #include <linux/smp_lock.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 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         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 (down_trylock (&epdata->lock) != 0)
 301                         goto nonblock;
 302                 if (epdata->state != STATE_EP_ENABLED) {
 303                         up (&epdata->lock);
 304 nonblock:
 305                         val = -EAGAIN;
 306                 } else
 307                         val = 0;
 308                 return val;
 309         }
 310
 311         if ((val = down_interruptible (&epdata->lock)) < 0)
 312                 return val;
 313
 314         switch (epdata->state) {
 315         case STATE_EP_ENABLED:
 316                 break;
 317         // case STATE_EP_DISABLED:              /* "can't happen" */
 318         // case STATE_EP_READY:                 /* "can't happen" */
 319         default:                                /* error! */
 320                 pr_debug ("%s: ep %p not available, state %d\n",
 321                                 shortname, epdata, epdata->state);
 322                 // FALLTHROUGH
 323         case STATE_EP_UNBOUND:                  /* clean disconnect */
 324                 val = -ENODEV;
 325                 up (&epdata->lock);
 326         }
 327         return val;
 328 }
 329
 330 static ssize_t
 331 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 332 {
 333         DECLARE_COMPLETION_ONSTACK (done);
 334         int value;
 335
 336         spin_lock_irq (&epdata->dev->lock);
 337         if (likely (epdata->ep != NULL)) {
 338                 struct usb_request      *req = epdata->req;
 339
 340                 req->context = &done;
 341                 req->complete = epio_complete;
 342                 req->buf = buf;
 343                 req->length = len;
 344                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 345         } else
 346                 value = -ENODEV;
 347         spin_unlock_irq (&epdata->dev->lock);
 348
 349         if (likely (value == 0)) {
 350                 value = wait_event_interruptible (done.wait, done.done);
 351                 if (value != 0) {
 352                         spin_lock_irq (&epdata->dev->lock);
 353                         if (likely (epdata->ep != NULL)) {
 354                                 DBG (epdata->dev, "%s i/o interrupted\n",
 355                                                 epdata->name);
 356                                 usb_ep_dequeue (epdata->ep, epdata->req);
 357                                 spin_unlock_irq (&epdata->dev->lock);
 358
 359                                 wait_event (done.wait, done.done);
 360                                 if (epdata->status == -ECONNRESET)
 361                                         epdata->status = -EINTR;
 362                         } else {
 363                                 spin_unlock_irq (&epdata->dev->lock);
 364
 365                                 DBG (epdata->dev, "endpoint gone\n");
 366                                 epdata->status = -ENODEV;
 367                         }
 368                 }
 369                 return epdata->status;
 370         }
 371         return value;
 372 }
 373
 374
 375 /* handle a synchronous OUT bulk/intr/iso transfer */
 376 static ssize_t
 377 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 378 {
 379         struct ep_data          *data = fd->private_data;
 380         void                    *kbuf;
 381         ssize_t                 value;
 382
 383         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 384                 return value;
 385
 386         /* halt any endpoint by doing a "wrong direction" i/o call */
 387         if (usb_endpoint_dir_in(&data->desc)) {
 388                 if (usb_endpoint_xfer_isoc(&data->desc))
 389                         return -EINVAL;
 390                 DBG (data->dev, "%s halt\n", data->name);
 391                 spin_lock_irq (&data->dev->lock);
 392                 if (likely (data->ep != NULL))
 393                         usb_ep_set_halt (data->ep);
 394                 spin_unlock_irq (&data->dev->lock);
 395                 up (&data->lock);
 396                 return -EBADMSG;
 397         }
 398
 399         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
 400
 401         value = -ENOMEM;
 402         kbuf = kmalloc (len, GFP_KERNEL);
 403         if (unlikely (!kbuf))
 404                 goto free1;
 405
 406         value = ep_io (data, kbuf, len);
 407         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
 408                 data->name, len, (int) value);
 409         if (value >= 0 && copy_to_user (buf, kbuf, value))
 410                 value = -EFAULT;
 411
 412 free1:
 413         up (&data->lock);
 414         kfree (kbuf);
 415         return value;
 416 }
 417
 418 /* handle a synchronous IN bulk/intr/iso transfer */
 419 static ssize_t
 420 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 421 {
 422         struct ep_data          *data = fd->private_data;
 423         void                    *kbuf;
 424         ssize_t                 value;
 425
 426         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 427                 return value;
 428
 429         /* halt any endpoint by doing a "wrong direction" i/o call */
 430         if (!usb_endpoint_dir_in(&data->desc)) {
 431                 if (usb_endpoint_xfer_isoc(&data->desc))
 432                         return -EINVAL;
 433                 DBG (data->dev, "%s halt\n", data->name);
 434                 spin_lock_irq (&data->dev->lock);
 435                 if (likely (data->ep != NULL))
 436                         usb_ep_set_halt (data->ep);
 437                 spin_unlock_irq (&data->dev->lock);
 438                 up (&data->lock);
 439                 return -EBADMSG;
 440         }
 441
 442         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
 443
 444         value = -ENOMEM;
 445         kbuf = kmalloc (len, GFP_KERNEL);
 446         if (!kbuf)
 447                 goto free1;
 448         if (copy_from_user (kbuf, buf, len)) {
 449                 value = -EFAULT;
 450                 goto free1;
 451         }
 452
 453         value = ep_io (data, kbuf, len);
 454         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
 455                 data->name, len, (int) value);
 456 free1:
 457         up (&data->lock);
 458         kfree (kbuf);
 459         return value;
 460 }
 461
 462 static int
 463 ep_release (struct inode *inode, struct file *fd)
 464 {
 465         struct ep_data          *data = fd->private_data;
 466         int value;
 467
 468         if ((value = down_interruptible(&data->lock)) < 0)
 469                 return value;
 470
 471         /* clean up if this can be reopened */
 472         if (data->state != STATE_EP_UNBOUND) {
 473                 data->state = STATE_EP_DISABLED;
 474                 data->desc.bDescriptorType = 0;
 475                 data->hs_desc.bDescriptorType = 0;
 476                 usb_ep_disable(data->ep);
 477         }
 478         up (&data->lock);
 479         put_ep (data);
 480         return 0;
 481 }
 482
 483 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
 484 {
 485         struct ep_data          *data = fd->private_data;
 486         int                     status;
 487
 488         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 489                 return status;
 490
 491         spin_lock_irq (&data->dev->lock);
 492         if (likely (data->ep != NULL)) {
 493                 switch (code) {
 494                 case GADGETFS_FIFO_STATUS:
 495                         status = usb_ep_fifo_status (data->ep);
 496                         break;
 497                 case GADGETFS_FIFO_FLUSH:
 498                         usb_ep_fifo_flush (data->ep);
 499                         break;
 500                 case GADGETFS_CLEAR_HALT:
 501                         status = usb_ep_clear_halt (data->ep);
 502                         break;
 503                 default:
 504                         status = -ENOTTY;
 505                 }
 506         } else
 507                 status = -ENODEV;
 508         spin_unlock_irq (&data->dev->lock);
 509         up (&data->lock);
 510         return status;
 511 }
 512
 513 /*----------------------------------------------------------------------*/
 514
 515 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 516
 517 struct kiocb_priv {
 518         struct usb_request      *req;
 519         struct ep_data          *epdata;
 520         void                    *buf;
 521         const struct iovec      *iv;
 522         unsigned long           nr_segs;
 523         unsigned                actual;
 524 };
 525
 526 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
 527 {
 528         struct kiocb_priv       *priv = iocb->private;
 529         struct ep_data          *epdata;
 530         int                     value;
 531
 532         local_irq_disable();
 533         epdata = priv->epdata;
 534         // spin_lock(&epdata->dev->lock);
 535         kiocbSetCancelled(iocb);
 536         if (likely(epdata && epdata->ep && priv->req))
 537                 value = usb_ep_dequeue (epdata->ep, priv->req);
 538         else
 539                 value = -EINVAL;
 540         // spin_unlock(&epdata->dev->lock);
 541         local_irq_enable();
 542
 543         aio_put_req(iocb);
 544         return value;
 545 }
 546
 547 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
 548 {
 549         struct kiocb_priv       *priv = iocb->private;
 550         ssize_t                 len, total;
 551         void                    *to_copy;
 552         int                     i;
 553
 554         /* we "retry" to get the right mm context for this: */
 555
 556         /* copy stuff into user buffers */
 557         total = priv->actual;
 558         len = 0;
 559         to_copy = priv->buf;
 560         for (i=0; i < priv->nr_segs; i++) {
 561                 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
 562
 563                 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
 564                         if (len == 0)
 565                                 len = -EFAULT;
 566                         break;
 567                 }
 568
 569                 total -= this;
 570                 len += this;
 571                 to_copy += this;
 572                 if (total == 0)
 573                         break;
 574         }
 575         kfree(priv->buf);
 576         kfree(priv);
 577         return len;
 578 }
 579
 580 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 581 {
 582         struct kiocb            *iocb = req->context;
 583         struct kiocb_priv       *priv = iocb->private;
 584         struct ep_data          *epdata = priv->epdata;
 585
 586         /* lock against disconnect (and ideally, cancel) */
 587         spin_lock(&epdata->dev->lock);
 588         priv->req = NULL;
 589         priv->epdata = NULL;
 590
 591         /* if this was a write or a read returning no data then we
 592          * don't need to copy anything to userspace, so we can
 593          * complete the aio request immediately.
 594          */
 595         if (priv->iv == NULL || unlikely(req->actual == 0)) {
 596                 kfree(req->buf);
 597                 kfree(priv);
 598                 iocb->private = NULL;
 599                 /* aio_complete() reports bytes-transferred _and_ faults */
 600                 aio_complete(iocb, req->actual ? req->actual : req->status,
 601                                 req->status);
 602         } else {
 603                 /* retry() won't report both; so we hide some faults */
 604                 if (unlikely(0 != req->status))
 605                         DBG(epdata->dev, "%s fault %d len %d\n",
 606                                 ep->name, req->status, req->actual);
 607
 608                 priv->buf = req->buf;
 609                 priv->actual = req->actual;
 610                 kick_iocb(iocb);
 611         }
 612         spin_unlock(&epdata->dev->lock);
 613
 614         usb_ep_free_request(ep, req);
 615         put_ep(epdata);
 616 }
 617
 618 static ssize_t
 619 ep_aio_rwtail(
 620         struct kiocb    *iocb,
 621         char            *buf,
 622         size_t          len,
 623         struct ep_data  *epdata,
 624         const struct iovec *iv,
 625         unsigned long   nr_segs
 626 )
 627 {
 628         struct kiocb_priv       *priv;
 629         struct usb_request      *req;
 630         ssize_t                 value;
 631
 632         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 633         if (!priv) {
 634                 value = -ENOMEM;
 635 fail:
 636                 kfree(buf);
 637                 return value;
 638         }
 639         iocb->private = priv;
 640         priv->iv = iv;
 641         priv->nr_segs = nr_segs;
 642
 643         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 644         if (unlikely(value < 0)) {
 645                 kfree(priv);
 646                 goto fail;
 647         }
 648
 649         iocb->ki_cancel = ep_aio_cancel;
 650         get_ep(epdata);
 651         priv->epdata = epdata;
 652         priv->actual = 0;
 653
 654         /* each kiocb is coupled to one usb_request, but we can't
 655          * allocate or submit those if the host disconnected.
 656          */
 657         spin_lock_irq(&epdata->dev->lock);
 658         if (likely(epdata->ep)) {
 659                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 660                 if (likely(req)) {
 661                         priv->req = req;
 662                         req->buf = buf;
 663                         req->length = len;
 664                         req->complete = ep_aio_complete;
 665                         req->context = iocb;
 666                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 667                         if (unlikely(0 != value))
 668                                 usb_ep_free_request(epdata->ep, req);
 669                 } else
 670                         value = -EAGAIN;
 671         } else
 672                 value = -ENODEV;
 673         spin_unlock_irq(&epdata->dev->lock);
 674
 675         up(&epdata->lock);
 676
 677         if (unlikely(value)) {
 678                 kfree(priv);
 679                 put_ep(epdata);
 680         } else
 681                 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
 682         return value;
 683 }
 684
 685 static ssize_t
 686 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
 687                 unsigned long nr_segs, loff_t o)
 688 {
 689         struct ep_data          *epdata = iocb->ki_filp->private_data;
 690         char                    *buf;
 691
 692         if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
 693                 return -EINVAL;
 694
 695         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 696         if (unlikely(!buf))
 697                 return -ENOMEM;
 698
 699         iocb->ki_retry = ep_aio_read_retry;
 700         return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
 701 }
 702
 703 static ssize_t
 704 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
 705                 unsigned long nr_segs, loff_t o)
 706 {
 707         struct ep_data          *epdata = iocb->ki_filp->private_data;
 708         char                    *buf;
 709         size_t                  len = 0;
 710         int                     i = 0;
 711
 712         if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
 713                 return -EINVAL;
 714
 715         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 716         if (unlikely(!buf))
 717                 return -ENOMEM;
 718
 719         for (i=0; i < nr_segs; i++) {
 720                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
 721                                 iov[i].iov_len) != 0)) {
 722                         kfree(buf);
 723                         return -EFAULT;
 724                 }
 725                 len += iov[i].iov_len;
 726         }
 727         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
 728 }
 729
 730 /*----------------------------------------------------------------------*/
 731
 732 /* used after endpoint configuration */
 733 static const struct file_operations ep_io_operations = {
 734         .owner =        THIS_MODULE,
 735         .llseek =       no_llseek,
 736
 737         .read =         ep_read,
 738         .write =        ep_write,
 739         .unlocked_ioctl = ep_ioctl,
 740         .release =      ep_release,
 741
 742         .aio_read =     ep_aio_read,
 743         .aio_write =    ep_aio_write,
 744 };
 745
 746 /* ENDPOINT INITIALIZATION
 747  *
 748  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 749  *     status = write (fd, descriptors, sizeof descriptors)
 750  *
 751  * That write establishes the endpoint configuration, configuring
 752  * the controller to process bulk, interrupt, or isochronous transfers
 753  * at the right maxpacket size, and so on.
 754  *
 755  * The descriptors are message type 1, identified by a host order u32
 756  * at the beginning of what's written.  Descriptor order is: full/low
 757  * speed descriptor, then optional high speed descriptor.
 758  */
 759 static ssize_t
 760 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 761 {
 762         struct ep_data          *data = fd->private_data;
 763         struct usb_ep           *ep;
 764         u32                     tag;
 765         int                     value, length = len;
 766
 767         if ((value = down_interruptible (&data->lock)) < 0)
 768                 return value;
 769
 770         if (data->state != STATE_EP_READY) {
 771                 value = -EL2HLT;
 772                 goto fail;
 773         }
 774
 775         value = len;
 776         if (len < USB_DT_ENDPOINT_SIZE + 4)
 777                 goto fail0;
 778
 779         /* we might need to change message format someday */
 780         if (copy_from_user (&tag, buf, 4)) {
 781                 goto fail1;
 782         }
 783         if (tag != 1) {
 784                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 785                 goto fail0;
 786         }
 787         buf += 4;
 788         len -= 4;
 789
 790         /* NOTE:  audio endpoint extensions not accepted here;
 791          * just don't include the extra bytes.
 792          */
 793
 794         /* full/low speed descriptor, then high speed */
 795         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 796                 goto fail1;
 797         }
 798         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 799                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 800                 goto fail0;
 801         if (len != USB_DT_ENDPOINT_SIZE) {
 802                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 803                         goto fail0;
 804                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 805                                         USB_DT_ENDPOINT_SIZE)) {
 806                         goto fail1;
 807                 }
 808                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 809                                 || data->hs_desc.bDescriptorType
 810                                         != USB_DT_ENDPOINT) {
 811                         DBG(data->dev, "config %s, bad hs length or type\n",
 812                                         data->name);
 813                         goto fail0;
 814                 }
 815         }
 816
 817         spin_lock_irq (&data->dev->lock);
 818         if (data->dev->state == STATE_DEV_UNBOUND) {
 819                 value = -ENOENT;
 820                 goto gone;
 821         } else if ((ep = data->ep) == NULL) {
 822                 value = -ENODEV;
 823                 goto gone;
 824         }
 825         switch (data->dev->gadget->speed) {
 826         case USB_SPEED_LOW:
 827         case USB_SPEED_FULL:
 828                 value = usb_ep_enable (ep, &data->desc);
 829                 if (value == 0)
 830                         data->state = STATE_EP_ENABLED;
 831                 break;
 832 #ifdef  CONFIG_USB_GADGET_DUALSPEED
 833         case USB_SPEED_HIGH:
 834                 /* fails if caller didn't provide that descriptor... */
 835                 value = usb_ep_enable (ep, &data->hs_desc);
 836                 if (value == 0)
 837                         data->state = STATE_EP_ENABLED;
 838                 break;
 839 #endif
 840         default:
 841                 DBG(data->dev, "unconnected, %s init abandoned\n",
 842                                 data->name);
 843                 value = -EINVAL;
 844         }
 845         if (value == 0) {
 846                 fd->f_op = &ep_io_operations;
 847                 value = length;
 848         }
 849 gone:
 850         spin_unlock_irq (&data->dev->lock);
 851         if (value < 0) {
 852 fail:
 853                 data->desc.bDescriptorType = 0;
 854                 data->hs_desc.bDescriptorType = 0;
 855         }
 856         up (&data->lock);
 857         return value;
 858 fail0:
 859         value = -EINVAL;
 860         goto fail;
 861 fail1:
 862         value = -EFAULT;
 863         goto fail;
 864 }
 865
 866 static int
 867 ep_open (struct inode *inode, struct file *fd)
 868 {
 869         struct ep_data          *data = inode->i_private;
 870         int                     value = -EBUSY;
 871
 872         if (down_interruptible (&data->lock) != 0)
 873                 return -EINTR;
 874         spin_lock_irq (&data->dev->lock);
 875         if (data->dev->state == STATE_DEV_UNBOUND)
 876                 value = -ENOENT;
 877         else if (data->state == STATE_EP_DISABLED) {
 878                 value = 0;
 879                 data->state = STATE_EP_READY;
 880                 get_ep (data);
 881                 fd->private_data = data;
 882                 VDEBUG (data->dev, "%s ready\n", data->name);
 883         } else
 884                 DBG (data->dev, "%s state %d\n",
 885                         data->name, data->state);
 886         spin_unlock_irq (&data->dev->lock);
 887         up (&data->lock);
 888         return value;
 889 }
 890
 891 /* used before endpoint configuration */
 892 static const struct file_operations ep_config_operations = {
 893         .owner =        THIS_MODULE,
 894         .llseek =       no_llseek,
 895
 896         .open =         ep_open,
 897         .write =        ep_config,
 898         .release =      ep_release,
 899 };
 900
 901 /*----------------------------------------------------------------------*/
 902
 903 /* EP0 IMPLEMENTATION can be partly in userspace.
 904  *
 905  * Drivers that use this facility receive various events, including
 906  * control requests the kernel doesn't handle.  Drivers that don't
 907  * use this facility may be too simple-minded for real applications.
 908  */
 909
 910 static inline void ep0_readable (struct dev_data *dev)
 911 {
 912         wake_up (&dev->wait);
 913         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 914 }
 915
 916 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 917 {
 918         struct dev_data         *dev = ep->driver_data;
 919
 920         if (req->buf != dev->rbuf) {
 921                 kfree(req->buf);
 922                 req->buf = dev->rbuf;
 923                 req->dma = DMA_ADDR_INVALID;
 924         }
 925         req->complete = epio_complete;
 926         dev->setup_out_ready = 0;
 927 }
 928
 929 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 930 {
 931         struct dev_data         *dev = ep->driver_data;
 932         unsigned long           flags;
 933         int                     free = 1;
 934
 935         /* for control OUT, data must still get to userspace */
 936         spin_lock_irqsave(&dev->lock, flags);
 937         if (!dev->setup_in) {
 938                 dev->setup_out_error = (req->status != 0);
 939                 if (!dev->setup_out_error)
 940                         free = 0;
 941                 dev->setup_out_ready = 1;
 942                 ep0_readable (dev);
 943         }
 944
 945         /* clean up as appropriate */
 946         if (free && req->buf != &dev->rbuf)
 947                 clean_req (ep, req);
 948         req->complete = epio_complete;
 949         spin_unlock_irqrestore(&dev->lock, flags);
 950 }
 951
 952 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 953 {
 954         struct dev_data *dev = ep->driver_data;
 955
 956         if (dev->setup_out_ready) {
 957                 DBG (dev, "ep0 request busy!\n");
 958                 return -EBUSY;
 959         }
 960         if (len > sizeof (dev->rbuf))
 961                 req->buf = kmalloc(len, GFP_ATOMIC);
 962         if (req->buf == NULL) {
 963                 req->buf = dev->rbuf;
 964                 return -ENOMEM;
 965         }
 966         req->complete = ep0_complete;
 967         req->length = len;
 968         req->zero = 0;
 969         return 0;
 970 }
 971
 972 static ssize_t
 973 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 974 {
 975         struct dev_data                 *dev = fd->private_data;
 976         ssize_t                         retval;
 977         enum ep0_state                  state;
 978
 979         spin_lock_irq (&dev->lock);
 980
 981         /* report fd mode change before acting on it */
 982         if (dev->setup_abort) {
 983                 dev->setup_abort = 0;
 984                 retval = -EIDRM;
 985                 goto done;
 986         }
 987
 988         /* control DATA stage */
 989         if ((state = dev->state) == STATE_DEV_SETUP) {
 990
 991                 if (dev->setup_in) {            /* stall IN */
 992                         VDEBUG(dev, "ep0in stall\n");
 993                         (void) usb_ep_set_halt (dev->gadget->ep0);
 994                         retval = -EL2HLT;
 995                         dev->state = STATE_DEV_CONNECTED;
 996
 997                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
 998                         struct usb_ep           *ep = dev->gadget->ep0;
 999                         struct usb_request      *req = dev->req;
1000
1001                         if ((retval = setup_req (ep, req, 0)) == 0)
1002                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1003                         dev->state = STATE_DEV_CONNECTED;
1004
1005                         /* assume that was SET_CONFIGURATION */
1006                         if (dev->current_config) {
1007                                 unsigned power;
1008
1009                                 if (gadget_is_dualspeed(dev->gadget)
1010                                                 && (dev->gadget->speed
1011                                                         == USB_SPEED_HIGH))
1012                                         power = dev->hs_config->bMaxPower;
1013                                 else
1014                                         power = dev->config->bMaxPower;
1015                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1016                         }
1017
1018                 } else {                        /* collect OUT data */
1019                         if ((fd->f_flags & O_NONBLOCK) != 0
1020                                         && !dev->setup_out_ready) {
1021                                 retval = -EAGAIN;
1022                                 goto done;
1023                         }
1024                         spin_unlock_irq (&dev->lock);
1025                         retval = wait_event_interruptible (dev->wait,
1026                                         dev->setup_out_ready != 0);
1027
1028                         /* FIXME state could change from under us */
1029                         spin_lock_irq (&dev->lock);
1030                         if (retval)
1031                                 goto done;
1032
1033                         if (dev->state != STATE_DEV_SETUP) {
1034                                 retval = -ECANCELED;
1035                                 goto done;
1036                         }
1037                         dev->state = STATE_DEV_CONNECTED;
1038
1039                         if (dev->setup_out_error)
1040                                 retval = -EIO;
1041                         else {
1042                                 len = min (len, (size_t)dev->req->actual);
1043 // FIXME don't call this with the spinlock held ...
1044                                 if (copy_to_user (buf, dev->req->buf, len))
1045                                         retval = -EFAULT;
1046                                 clean_req (dev->gadget->ep0, dev->req);
1047                                 /* NOTE userspace can't yet choose to stall */
1048                         }
1049                 }
1050                 goto done;
1051         }
1052
1053         /* else normal: return event data */
1054         if (len < sizeof dev->event [0]) {
1055                 retval = -EINVAL;
1056                 goto done;
1057         }
1058         len -= len % sizeof (struct usb_gadgetfs_event);
1059         dev->usermode_setup = 1;
1060
1061 scan:
1062         /* return queued events right away */
1063         if (dev->ev_next != 0) {
1064                 unsigned                i, n;
1065
1066                 n = len / sizeof (struct usb_gadgetfs_event);
1067                 if (dev->ev_next < n)
1068                         n = dev->ev_next;
1069
1070                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1071                 for (i = 0; i < n; i++) {
1072                         if (dev->event [i].type == GADGETFS_SETUP) {
1073                                 dev->state = STATE_DEV_SETUP;
1074                                 n = i + 1;
1075                                 break;
1076                         }
1077                 }
1078                 spin_unlock_irq (&dev->lock);
1079                 len = n * sizeof (struct usb_gadgetfs_event);
1080                 if (copy_to_user (buf, &dev->event, len))
1081                         retval = -EFAULT;
1082                 else
1083                         retval = len;
1084                 if (len > 0) {
1085                         /* NOTE this doesn't guard against broken drivers;
1086                          * concurrent ep0 readers may lose events.
1087                          */
1088                         spin_lock_irq (&dev->lock);
1089                         if (dev->ev_next > n) {
1090                                 memmove(&dev->event[0], &dev->event[n],
1091                                         sizeof (struct usb_gadgetfs_event)
1092                                                 * (dev->ev_next - n));
1093                         }
1094                         dev->ev_next -= n;
1095                         spin_unlock_irq (&dev->lock);
1096                 }
1097                 return retval;
1098         }
1099         if (fd->f_flags & O_NONBLOCK) {
1100                 retval = -EAGAIN;
1101                 goto done;
1102         }
1103
1104         switch (state) {
1105         default:
1106                 DBG (dev, "fail %s, state %d\n", __func__, state);
1107                 retval = -ESRCH;
1108                 break;
1109         case STATE_DEV_UNCONNECTED:
1110         case STATE_DEV_CONNECTED:
1111                 spin_unlock_irq (&dev->lock);
1112                 DBG (dev, "%s wait\n", __func__);
1113
1114                 /* wait for events */
1115                 retval = wait_event_interruptible (dev->wait,
1116                                 dev->ev_next != 0);
1117                 if (retval < 0)
1118                         return retval;
1119                 spin_lock_irq (&dev->lock);
1120                 goto scan;
1121         }
1122
1123 done:
1124         spin_unlock_irq (&dev->lock);
1125         return retval;
1126 }
1127
1128 static struct usb_gadgetfs_event *
1129 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1130 {
1131         struct usb_gadgetfs_event       *event;
1132         unsigned                        i;
1133
1134         switch (type) {
1135         /* these events purge the queue */
1136         case GADGETFS_DISCONNECT:
1137                 if (dev->state == STATE_DEV_SETUP)
1138                         dev->setup_abort = 1;
1139                 // FALL THROUGH
1140         case GADGETFS_CONNECT:
1141                 dev->ev_next = 0;
1142                 break;
1143         case GADGETFS_SETUP:            /* previous request timed out */
1144         case GADGETFS_SUSPEND:          /* same effect */
1145                 /* these events can't be repeated */
1146                 for (i = 0; i != dev->ev_next; i++) {
1147                         if (dev->event [i].type != type)
1148                                 continue;
1149                         DBG(dev, "discard old event[%d] %d\n", i, type);
1150                         dev->ev_next--;
1151                         if (i == dev->ev_next)
1152                                 break;
1153                         /* indices start at zero, for simplicity */
1154                         memmove (&dev->event [i], &dev->event [i + 1],
1155                                 sizeof (struct usb_gadgetfs_event)
1156                                         * (dev->ev_next - i));
1157                 }
1158                 break;
1159         default:
1160                 BUG ();
1161         }
1162         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1163         event = &dev->event [dev->ev_next++];
1164         BUG_ON (dev->ev_next > N_EVENT);
1165         memset (event, 0, sizeof *event);
1166         event->type = type;
1167         return event;
1168 }
1169
1170 static ssize_t
1171 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1172 {
1173         struct dev_data         *dev = fd->private_data;
1174         ssize_t                 retval = -ESRCH;
1175
1176         spin_lock_irq (&dev->lock);
1177
1178         /* report fd mode change before acting on it */
1179         if (dev->setup_abort) {
1180                 dev->setup_abort = 0;
1181                 retval = -EIDRM;
1182
1183         /* data and/or status stage for control request */
1184         } else if (dev->state == STATE_DEV_SETUP) {
1185
1186                 /* IN DATA+STATUS caller makes len <= wLength */
1187                 if (dev->setup_in) {
1188                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1189                         if (retval == 0) {
1190                                 dev->state = STATE_DEV_CONNECTED;
1191                                 spin_unlock_irq (&dev->lock);
1192                                 if (copy_from_user (dev->req->buf, buf, len))
1193                                         retval = -EFAULT;
1194                                 else {
1195                                         if (len < dev->setup_wLength)
1196                                                 dev->req->zero = 1;
1197                                         retval = usb_ep_queue (
1198                                                 dev->gadget->ep0, dev->req,
1199                                                 GFP_KERNEL);
1200                                 }
1201                                 if (retval < 0) {
1202                                         spin_lock_irq (&dev->lock);
1203                                         clean_req (dev->gadget->ep0, dev->req);
1204                                         spin_unlock_irq (&dev->lock);
1205                                 } else
1206                                         retval = len;
1207
1208                                 return retval;
1209                         }
1210
1211                 /* can stall some OUT transfers */
1212                 } else if (dev->setup_can_stall) {
1213                         VDEBUG(dev, "ep0out stall\n");
1214                         (void) usb_ep_set_halt (dev->gadget->ep0);
1215                         retval = -EL2HLT;
1216                         dev->state = STATE_DEV_CONNECTED;
1217                 } else {
1218                         DBG(dev, "bogus ep0out stall!\n");
1219                 }
1220         } else
1221                 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1222
1223         spin_unlock_irq (&dev->lock);
1224         return retval;
1225 }
1226
1227 static int
1228 ep0_fasync (int f, struct file *fd, int on)
1229 {
1230         struct dev_data         *dev = fd->private_data;
1231         // caller must F_SETOWN before signal delivery happens
1232         VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1233         return fasync_helper (f, fd, on, &dev->fasync);
1234 }
1235
1236 static struct usb_gadget_driver gadgetfs_driver;
1237
1238 static int
1239 dev_release (struct inode *inode, struct file *fd)
1240 {
1241         struct dev_data         *dev = fd->private_data;
1242
1243         /* closing ep0 === shutdown all */
1244
1245         usb_gadget_unregister_driver (&gadgetfs_driver);
1246
1247         /* at this point "good" hardware has disconnected the
1248          * device from USB; the host won't see it any more.
1249          * alternatively, all host requests will time out.
1250          */
1251
1252         kfree (dev->buf);
1253         dev->buf = NULL;
1254         put_dev (dev);
1255
1256         /* other endpoints were all decoupled from this device */
1257         spin_lock_irq(&dev->lock);
1258         dev->state = STATE_DEV_DISABLED;
1259         spin_unlock_irq(&dev->lock);
1260         return 0;
1261 }
1262
1263 static unsigned int
1264 ep0_poll (struct file *fd, poll_table *wait)
1265 {
1266        struct dev_data         *dev = fd->private_data;
1267        int                     mask = 0;
1268
1269        poll_wait(fd, &dev->wait, wait);
1270
1271        spin_lock_irq (&dev->lock);
1272
1273        /* report fd mode change before acting on it */
1274        if (dev->setup_abort) {
1275                dev->setup_abort = 0;
1276                mask = POLLHUP;
1277                goto out;
1278        }
1279
1280        if (dev->state == STATE_DEV_SETUP) {
1281                if (dev->setup_in || dev->setup_can_stall)
1282                        mask = POLLOUT;
1283        } else {
1284                if (dev->ev_next != 0)
1285                        mask = POLLIN;
1286        }
1287 out:
1288        spin_unlock_irq(&dev->lock);
1289        return mask;
1290 }
1291
1292 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1293 {
1294         struct dev_data         *dev = fd->private_data;
1295         struct usb_gadget       *gadget = dev->gadget;
1296         long ret = -ENOTTY;
1297
1298         if (gadget->ops->ioctl) {
1299                 lock_kernel();
1300                 ret = gadget->ops->ioctl (gadget, code, value);
1301                 unlock_kernel();
1302         }
1303         return ret;
1304 }
1305
1306 /* used after device configuration */
1307 static const struct file_operations ep0_io_operations = {
1308         .owner =        THIS_MODULE,
1309         .llseek =       no_llseek,
1310
1311         .read =         ep0_read,
1312         .write =        ep0_write,
1313         .fasync =       ep0_fasync,
1314         .poll =         ep0_poll,
1315         .unlocked_ioctl =       dev_ioctl,
1316         .release =      dev_release,
1317 };
1318
1319 /*----------------------------------------------------------------------*/
1320
1321 /* The in-kernel gadget driver handles most ep0 issues, in particular
1322  * enumerating the single configuration (as provided from user space).
1323  *
1324  * Unrecognized ep0 requests may be handled in user space.
1325  */
1326
1327 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1328 static void make_qualifier (struct dev_data *dev)
1329 {
1330         struct usb_qualifier_descriptor         qual;
1331         struct usb_device_descriptor            *desc;
1332
1333         qual.bLength = sizeof qual;
1334         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1335         qual.bcdUSB = cpu_to_le16 (0x0200);
1336
1337         desc = dev->dev;
1338         qual.bDeviceClass = desc->bDeviceClass;
1339         qual.bDeviceSubClass = desc->bDeviceSubClass;
1340         qual.bDeviceProtocol = desc->bDeviceProtocol;
1341
1342         /* assumes ep0 uses the same value for both speeds ... */
1343         qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
1344
1345         qual.bNumConfigurations = 1;
1346         qual.bRESERVED = 0;
1347
1348         memcpy (dev->rbuf, &qual, sizeof qual);
1349 }
1350 #endif
1351
1352 static int
1353 config_buf (struct dev_data *dev, u8 type, unsigned index)
1354 {
1355         int             len;
1356         int             hs = 0;
1357
1358         /* only one configuration */
1359         if (index > 0)
1360                 return -EINVAL;
1361
1362         if (gadget_is_dualspeed(dev->gadget)) {
1363                 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1364                 if (type == USB_DT_OTHER_SPEED_CONFIG)
1365                         hs = !hs;
1366         }
1367         if (hs) {
1368                 dev->req->buf = dev->hs_config;
1369                 len = le16_to_cpu(dev->hs_config->wTotalLength);
1370         } else {
1371                 dev->req->buf = dev->config;
1372                 len = le16_to_cpu(dev->config->wTotalLength);
1373         }
1374         ((u8 *)dev->req->buf) [1] = type;
1375         return len;
1376 }
1377
1378 static int
1379 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1380 {
1381         struct dev_data                 *dev = get_gadget_data (gadget);
1382         struct usb_request              *req = dev->req;
1383         int                             value = -EOPNOTSUPP;
1384         struct usb_gadgetfs_event       *event;
1385         u16                             w_value = le16_to_cpu(ctrl->wValue);
1386         u16                             w_length = le16_to_cpu(ctrl->wLength);
1387
1388         spin_lock (&dev->lock);
1389         dev->setup_abort = 0;
1390         if (dev->state == STATE_DEV_UNCONNECTED) {
1391                 if (gadget_is_dualspeed(gadget)
1392                                 && gadget->speed == USB_SPEED_HIGH
1393                                 && dev->hs_config == NULL) {
1394                         spin_unlock(&dev->lock);
1395                         ERROR (dev, "no high speed config??\n");
1396                         return -EINVAL;
1397                 }
1398
1399                 dev->state = STATE_DEV_CONNECTED;
1400                 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1401
1402                 INFO (dev, "connected\n");
1403                 event = next_event (dev, GADGETFS_CONNECT);
1404                 event->u.speed = gadget->speed;
1405                 ep0_readable (dev);
1406
1407         /* host may have given up waiting for response.  we can miss control
1408          * requests handled lower down (device/endpoint status and features);
1409          * then ep0_{read,write} will report the wrong status. controller
1410          * driver will have aborted pending i/o.
1411          */
1412         } else if (dev->state == STATE_DEV_SETUP)
1413                 dev->setup_abort = 1;
1414
1415         req->buf = dev->rbuf;
1416         req->dma = DMA_ADDR_INVALID;
1417         req->context = NULL;
1418         value = -EOPNOTSUPP;
1419         switch (ctrl->bRequest) {
1420
1421         case USB_REQ_GET_DESCRIPTOR:
1422                 if (ctrl->bRequestType != USB_DIR_IN)
1423                         goto unrecognized;
1424                 switch (w_value >> 8) {
1425
1426                 case USB_DT_DEVICE:
1427                         value = min (w_length, (u16) sizeof *dev->dev);
1428                         req->buf = dev->dev;
1429                         break;
1430 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1431                 case USB_DT_DEVICE_QUALIFIER:
1432                         if (!dev->hs_config)
1433                                 break;
1434                         value = min (w_length, (u16)
1435                                 sizeof (struct usb_qualifier_descriptor));
1436                         make_qualifier (dev);
1437                         break;
1438                 case USB_DT_OTHER_SPEED_CONFIG:
1439                         // FALLTHROUGH
1440 #endif
1441                 case USB_DT_CONFIG:
1442                         value = config_buf (dev,
1443                                         w_value >> 8,
1444                                         w_value & 0xff);
1445                         if (value >= 0)
1446                                 value = min (w_length, (u16) value);
1447                         break;
1448                 case USB_DT_STRING:
1449                         goto unrecognized;
1450
1451                 default:                // all others are errors
1452                         break;
1453                 }
1454                 break;
1455
1456         /* currently one config, two speeds */
1457         case USB_REQ_SET_CONFIGURATION:
1458                 if (ctrl->bRequestType != 0)
1459                         goto unrecognized;
1460                 if (0 == (u8) w_value) {
1461                         value = 0;
1462                         dev->current_config = 0;
1463                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1464                         // user mode expected to disable endpoints
1465                 } else {
1466                         u8      config, power;
1467
1468                         if (gadget_is_dualspeed(gadget)
1469                                         && gadget->speed == USB_SPEED_HIGH) {
1470                                 config = dev->hs_config->bConfigurationValue;
1471                                 power = dev->hs_config->bMaxPower;
1472                         } else {
1473                                 config = dev->config->bConfigurationValue;
1474                                 power = dev->config->bMaxPower;
1475                         }
1476
1477                         if (config == (u8) w_value) {
1478                                 value = 0;
1479                                 dev->current_config = config;
1480                                 usb_gadget_vbus_draw(gadget, 2 * power);
1481                         }
1482                 }
1483
1484                 /* report SET_CONFIGURATION like any other control request,
1485                  * except that usermode may not stall this.  the next
1486                  * request mustn't be allowed start until this finishes:
1487                  * endpoints and threads set up, etc.
1488                  *
1489                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1490                  * has bad/racey automagic that prevents synchronizing here.
1491                  * even kernel mode drivers often miss them.
1492                  */
1493                 if (value == 0) {
1494                         INFO (dev, "configuration #%d\n", dev->current_config);
1495                         if (dev->usermode_setup) {
1496                                 dev->setup_can_stall = 0;
1497                                 goto delegate;
1498                         }
1499                 }
1500                 break;
1501
1502 #ifndef CONFIG_USB_GADGET_PXA25X
1503         /* PXA automagically handles this request too */
1504         case USB_REQ_GET_CONFIGURATION:
1505                 if (ctrl->bRequestType != 0x80)
1506                         goto unrecognized;
1507                 *(u8 *)req->buf = dev->current_config;
1508                 value = min (w_length, (u16) 1);
1509                 break;
1510 #endif
1511
1512         default:
1513 unrecognized:
1514                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1515                         dev->usermode_setup ? "delegate" : "fail",
1516                         ctrl->bRequestType, ctrl->bRequest,
1517                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1518
1519                 /* if there's an ep0 reader, don't stall */
1520                 if (dev->usermode_setup) {
1521                         dev->setup_can_stall = 1;
1522 delegate:
1523                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1524                                                 ? 1 : 0;
1525                         dev->setup_wLength = w_length;
1526                         dev->setup_out_ready = 0;
1527                         dev->setup_out_error = 0;
1528                         value = 0;
1529
1530                         /* read DATA stage for OUT right away */
1531                         if (unlikely (!dev->setup_in && w_length)) {
1532                                 value = setup_req (gadget->ep0, dev->req,
1533                                                         w_length);
1534                                 if (value < 0)
1535                                         break;
1536                                 value = usb_ep_queue (gadget->ep0, dev->req,
1537                                                         GFP_ATOMIC);
1538                                 if (value < 0) {
1539                                         clean_req (gadget->ep0, dev->req);
1540                                         break;
1541                                 }
1542
1543                                 /* we can't currently stall these */
1544                                 dev->setup_can_stall = 0;
1545                         }
1546
1547                         /* state changes when reader collects event */
1548                         event = next_event (dev, GADGETFS_SETUP);
1549                         event->u.setup = *ctrl;
1550                         ep0_readable (dev);
1551                         spin_unlock (&dev->lock);
1552                         return 0;
1553                 }
1554         }
1555
1556         /* proceed with data transfer and status phases? */
1557         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1558                 req->length = value;
1559                 req->zero = value < w_length;
1560                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1561                 if (value < 0) {
1562                         DBG (dev, "ep_queue --> %d\n", value);
1563                         req->status = 0;
1564                 }
1565         }
1566
1567         /* device stalls when value < 0 */
1568         spin_unlock (&dev->lock);
1569         return value;
1570 }
1571
1572 static void destroy_ep_files (struct dev_data *dev)
1573 {
1574         struct list_head        *entry, *tmp;
1575
1576         DBG (dev, "%s %d\n", __func__, dev->state);
1577
1578         /* dev->state must prevent interference */
1579 restart:
1580         spin_lock_irq (&dev->lock);
1581         list_for_each_safe (entry, tmp, &dev->epfiles) {
1582                 struct ep_data  *ep;
1583                 struct inode    *parent;
1584                 struct dentry   *dentry;
1585
1586                 /* break link to FS */
1587                 ep = list_entry (entry, struct ep_data, epfiles);
1588                 list_del_init (&ep->epfiles);
1589                 dentry = ep->dentry;
1590                 ep->dentry = NULL;
1591                 parent = dentry->d_parent->d_inode;
1592
1593                 /* break link to controller */
1594                 if (ep->state == STATE_EP_ENABLED)
1595                         (void) usb_ep_disable (ep->ep);
1596                 ep->state = STATE_EP_UNBOUND;
1597                 usb_ep_free_request (ep->ep, ep->req);
1598                 ep->ep = NULL;
1599                 wake_up (&ep->wait);
1600                 put_ep (ep);
1601
1602                 spin_unlock_irq (&dev->lock);
1603
1604                 /* break link to dcache */
1605                 mutex_lock (&parent->i_mutex);
1606                 d_delete (dentry);
1607                 dput (dentry);
1608                 mutex_unlock (&parent->i_mutex);
1609
1610                 /* fds may still be open */
1611                 goto restart;
1612         }
1613         spin_unlock_irq (&dev->lock);
1614 }
1615
1616
1617 static struct inode *
1618 gadgetfs_create_file (struct super_block *sb, char const *name,
1619                 void *data, const struct file_operations *fops,
1620                 struct dentry **dentry_p);
1621
1622 static int activate_ep_files (struct dev_data *dev)
1623 {
1624         struct usb_ep   *ep;
1625         struct ep_data  *data;
1626
1627         gadget_for_each_ep (ep, dev->gadget) {
1628
1629                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1630                 if (!data)
1631                         goto enomem0;
1632                 data->state = STATE_EP_DISABLED;
1633                 init_MUTEX (&data->lock);
1634                 init_waitqueue_head (&data->wait);
1635
1636                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1637                 atomic_set (&data->count, 1);
1638                 data->dev = dev;
1639                 get_dev (dev);
1640
1641                 data->ep = ep;
1642                 ep->driver_data = data;
1643
1644                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1645                 if (!data->req)
1646                         goto enomem1;
1647
1648                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1649                                 data, &ep_config_operations,
1650                                 &data->dentry);
1651                 if (!data->inode)
1652                         goto enomem2;
1653                 list_add_tail (&data->epfiles, &dev->epfiles);
1654         }
1655         return 0;
1656
1657 enomem2:
1658         usb_ep_free_request (ep, data->req);
1659 enomem1:
1660         put_dev (dev);
1661         kfree (data);
1662 enomem0:
1663         DBG (dev, "%s enomem\n", __func__);
1664         destroy_ep_files (dev);
1665         return -ENOMEM;
1666 }
1667
1668 static void
1669 gadgetfs_unbind (struct usb_gadget *gadget)
1670 {
1671         struct dev_data         *dev = get_gadget_data (gadget);
1672
1673         DBG (dev, "%s\n", __func__);
1674
1675         spin_lock_irq (&dev->lock);
1676         dev->state = STATE_DEV_UNBOUND;
1677         spin_unlock_irq (&dev->lock);
1678
1679         destroy_ep_files (dev);
1680         gadget->ep0->driver_data = NULL;
1681         set_gadget_data (gadget, NULL);
1682
1683         /* we've already been disconnected ... no i/o is active */
1684         if (dev->req)
1685                 usb_ep_free_request (gadget->ep0, dev->req);
1686         DBG (dev, "%s done\n", __func__);
1687         put_dev (dev);
1688 }
1689
1690 static struct dev_data          *the_device;
1691
1692 static int
1693 gadgetfs_bind (struct usb_gadget *gadget)
1694 {
1695         struct dev_data         *dev = the_device;
1696
1697         if (!dev)
1698                 return -ESRCH;
1699         if (0 != strcmp (CHIP, gadget->name)) {
1700                 pr_err("%s expected %s controller not %s\n",
1701                         shortname, CHIP, gadget->name);
1702                 return -ENODEV;
1703         }
1704
1705         set_gadget_data (gadget, dev);
1706         dev->gadget = gadget;
1707         gadget->ep0->driver_data = dev;
1708         dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1709
1710         /* preallocate control response and buffer */
1711         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1712         if (!dev->req)
1713                 goto enomem;
1714         dev->req->context = NULL;
1715         dev->req->complete = epio_complete;
1716
1717         if (activate_ep_files (dev) < 0)
1718                 goto enomem;
1719
1720         INFO (dev, "bound to %s driver\n", gadget->name);
1721         spin_lock_irq(&dev->lock);
1722         dev->state = STATE_DEV_UNCONNECTED;
1723         spin_unlock_irq(&dev->lock);
1724         get_dev (dev);
1725         return 0;
1726
1727 enomem:
1728         gadgetfs_unbind (gadget);
1729         return -ENOMEM;
1730 }
1731
1732 static void
1733 gadgetfs_disconnect (struct usb_gadget *gadget)
1734 {
1735         struct dev_data         *dev = get_gadget_data (gadget);
1736
1737         spin_lock (&dev->lock);
1738         if (dev->state == STATE_DEV_UNCONNECTED)
1739                 goto exit;
1740         dev->state = STATE_DEV_UNCONNECTED;
1741
1742         INFO (dev, "disconnected\n");
1743         next_event (dev, GADGETFS_DISCONNECT);
1744         ep0_readable (dev);
1745 exit:
1746         spin_unlock (&dev->lock);
1747 }
1748
1749 static void
1750 gadgetfs_suspend (struct usb_gadget *gadget)
1751 {
1752         struct dev_data         *dev = get_gadget_data (gadget);
1753
1754         INFO (dev, "suspended from state %d\n", dev->state);
1755         spin_lock (&dev->lock);
1756         switch (dev->state) {
1757         case STATE_DEV_SETUP:           // VERY odd... host died??
1758         case STATE_DEV_CONNECTED:
1759         case STATE_DEV_UNCONNECTED:
1760                 next_event (dev, GADGETFS_SUSPEND);
1761                 ep0_readable (dev);
1762                 /* FALLTHROUGH */
1763         default:
1764                 break;
1765         }
1766         spin_unlock (&dev->lock);
1767 }
1768
1769 static struct usb_gadget_driver gadgetfs_driver = {
1770 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1771         .speed          = USB_SPEED_HIGH,
1772 #else
1773         .speed          = USB_SPEED_FULL,
1774 #endif
1775         .function       = (char *) driver_desc,
1776         .bind           = gadgetfs_bind,
1777         .unbind         = gadgetfs_unbind,
1778         .setup          = gadgetfs_setup,
1779         .disconnect     = gadgetfs_disconnect,
1780         .suspend        = gadgetfs_suspend,
1781
1782         .driver = {
1783                 .name           = (char *) shortname,
1784         },
1785 };
1786
1787 /*----------------------------------------------------------------------*/
1788
1789 static void gadgetfs_nop(struct usb_gadget *arg) { }
1790
1791 static int gadgetfs_probe (struct usb_gadget *gadget)
1792 {
1793         CHIP = gadget->name;
1794         return -EISNAM;
1795 }
1796
1797 static struct usb_gadget_driver probe_driver = {
1798         .speed          = USB_SPEED_HIGH,
1799         .bind           = gadgetfs_probe,
1800         .unbind         = gadgetfs_nop,
1801         .setup          = (void *)gadgetfs_nop,
1802         .disconnect     = gadgetfs_nop,
1803         .driver = {
1804                 .name           = "nop",
1805         },
1806 };
1807
1808
1809 /* DEVICE INITIALIZATION
1810  *
1811  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1812  *     status = write (fd, descriptors, sizeof descriptors)
1813  *
1814  * That write establishes the device configuration, so the kernel can
1815  * bind to the controller ... guaranteeing it can handle enumeration
1816  * at all necessary speeds.  Descriptor order is:
1817  *
1818  * . message tag (u32, host order) ... for now, must be zero; it
1819  *      would change to support features like multi-config devices
1820  * . full/low speed config ... all wTotalLength bytes (with interface,
1821  *      class, altsetting, endpoint, and other descriptors)
1822  * . high speed config ... all descriptors, for high speed operation;
1823  *      this one's optional except for high-speed hardware
1824  * . device descriptor
1825  *
1826  * Endpoints are not yet enabled. Drivers must wait until device
1827  * configuration and interface altsetting changes create
1828  * the need to configure (or unconfigure) them.
1829  *
1830  * After initialization, the device stays active for as long as that
1831  * $CHIP file is open.  Events must then be read from that descriptor,
1832  * such as configuration notifications.
1833  */
1834
1835 static int is_valid_config (struct usb_config_descriptor *config)
1836 {
1837         return config->bDescriptorType == USB_DT_CONFIG
1838                 && config->bLength == USB_DT_CONFIG_SIZE
1839                 && config->bConfigurationValue != 0
1840                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1841                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1842         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1843         /* FIXME check lengths: walk to end */
1844 }
1845
1846 static ssize_t
1847 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1848 {
1849         struct dev_data         *dev = fd->private_data;
1850         ssize_t                 value = len, length = len;
1851         unsigned                total;
1852         u32                     tag;
1853         char                    *kbuf;
1854
1855         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1856                 return -EINVAL;
1857
1858         /* we might need to change message format someday */
1859         if (copy_from_user (&tag, buf, 4))
1860                 return -EFAULT;
1861         if (tag != 0)
1862                 return -EINVAL;
1863         buf += 4;
1864         length -= 4;
1865
1866         kbuf = kmalloc (length, GFP_KERNEL);
1867         if (!kbuf)
1868                 return -ENOMEM;
1869         if (copy_from_user (kbuf, buf, length)) {
1870                 kfree (kbuf);
1871                 return -EFAULT;
1872         }
1873
1874         spin_lock_irq (&dev->lock);
1875         value = -EINVAL;
1876         if (dev->buf)
1877                 goto fail;
1878         dev->buf = kbuf;
1879
1880         /* full or low speed config */
1881         dev->config = (void *) kbuf;
1882         total = le16_to_cpu(dev->config->wTotalLength);
1883         if (!is_valid_config (dev->config) || total >= length)
1884                 goto fail;
1885         kbuf += total;
1886         length -= total;
1887
1888         /* optional high speed config */
1889         if (kbuf [1] == USB_DT_CONFIG) {
1890                 dev->hs_config = (void *) kbuf;
1891                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1892                 if (!is_valid_config (dev->hs_config) || total >= length)
1893                         goto fail;
1894                 kbuf += total;
1895                 length -= total;
1896         }
1897
1898         /* could support multiple configs, using another encoding! */
1899
1900         /* device descriptor (tweaked for paranoia) */
1901         if (length != USB_DT_DEVICE_SIZE)
1902                 goto fail;
1903         dev->dev = (void *)kbuf;
1904         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1905                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1906                         || dev->dev->bNumConfigurations != 1)
1907                 goto fail;
1908         dev->dev->bNumConfigurations = 1;
1909         dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1910
1911         /* triggers gadgetfs_bind(); then we can enumerate. */
1912         spin_unlock_irq (&dev->lock);
1913         value = usb_gadget_register_driver (&gadgetfs_driver);
1914         if (value != 0) {
1915                 kfree (dev->buf);
1916                 dev->buf = NULL;
1917         } else {
1918                 /* at this point "good" hardware has for the first time
1919                  * let the USB the host see us.  alternatively, if users
1920                  * unplug/replug that will clear all the error state.
1921                  *
1922                  * note:  everything running before here was guaranteed
1923                  * to choke driver model style diagnostics.  from here
1924                  * on, they can work ... except in cleanup paths that
1925                  * kick in after the ep0 descriptor is closed.
1926                  */
1927                 fd->f_op = &ep0_io_operations;
1928                 value = len;
1929         }
1930         return value;
1931
1932 fail:
1933         spin_unlock_irq (&dev->lock);
1934         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1935         kfree (dev->buf);
1936         dev->buf = NULL;
1937         return value;
1938 }
1939
1940 static int
1941 dev_open (struct inode *inode, struct file *fd)
1942 {
1943         struct dev_data         *dev = inode->i_private;
1944         int                     value = -EBUSY;
1945
1946         spin_lock_irq(&dev->lock);
1947         if (dev->state == STATE_DEV_DISABLED) {
1948                 dev->ev_next = 0;
1949                 dev->state = STATE_DEV_OPENED;
1950                 fd->private_data = dev;
1951                 get_dev (dev);
1952                 value = 0;
1953         }
1954         spin_unlock_irq(&dev->lock);
1955         return value;
1956 }
1957
1958 static const struct file_operations dev_init_operations = {
1959         .owner =        THIS_MODULE,
1960         .llseek =       no_llseek,
1961
1962         .open =         dev_open,
1963         .write =        dev_config,
1964         .fasync =       ep0_fasync,
1965         .unlocked_ioctl = dev_ioctl,
1966         .release =      dev_release,
1967 };
1968
1969 /*----------------------------------------------------------------------*/
1970
1971 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1972  *
1973  * Mounting the filesystem creates a controller file, used first for
1974  * device configuration then later for event monitoring.
1975  */
1976
1977
1978 /* FIXME PAM etc could set this security policy without mount options
1979  * if epfiles inherited ownership and permissons from ep0 ...
1980  */
1981
1982 static unsigned default_uid;
1983 static unsigned default_gid;
1984 static unsigned default_perm = S_IRUSR | S_IWUSR;
1985
1986 module_param (default_uid, uint, 0644);
1987 module_param (default_gid, uint, 0644);
1988 module_param (default_perm, uint, 0644);
1989
1990
1991 static struct inode *
1992 gadgetfs_make_inode (struct super_block *sb,
1993                 void *data, const struct file_operations *fops,
1994                 int mode)
1995 {
1996         struct inode *inode = new_inode (sb);
1997
1998         if (inode) {
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 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_register_driver (&probe_driver);
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 int
2105 gadgetfs_get_sb (struct file_system_type *t, int flags,
2106                 const char *path, void *opts, struct vfsmount *mnt)
2107 {
2108         return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt);
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         .get_sb         = gadgetfs_get_sb,
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