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
  13
  14 /* #define VERBOSE_DEBUG */
  15
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/fs.h>
  19 #include <linux/pagemap.h>
  20 #include <linux/uts.h>
  21 #include <linux/wait.h>
  22 #include <linux/compiler.h>
  23 #include <asm/uaccess.h>
  24 #include <linux/sched.h>
  25 #include <linux/slab.h>
  26 #include <linux/poll.h>
  27 #include <linux/mmu_context.h>
  28 #include <linux/aio.h>
  29
  30 #include <linux/device.h>
  31 #include <linux/moduleparam.h>
  32
  33 #include <linux/usb/gadgetfs.h>
  34 #include <linux/usb/gadget.h>
  35
  36
  37 /*
  38  * The gadgetfs API maps each endpoint to a file descriptor so that you
  39  * can use standard synchronous read/write calls for I/O.  There's some
  40  * O_NONBLOCK and O_ASYNC/FASYNC style i/o support.  Example usermode
  41  * drivers show how this works in practice.  You can also use AIO to
  42  * eliminate I/O gaps between requests, to help when streaming data.
  43  *
  44  * Key parts that must be USB-specific are protocols defining how the
  45  * read/write operations relate to the hardware state machines.  There
  46  * are two types of files.  One type is for the device, implementing ep0.
  47  * The other type is for each IN or OUT endpoint.  In both cases, the
  48  * user mode driver must configure the hardware before using it.
  49  *
  50  * - First, dev_config() is called when /dev/gadget/$CHIP is configured
  51  *   (by writing configuration and device descriptors).  Afterwards it
  52  *   may serve as a source of device events, used to handle all control
  53  *   requests other than basic enumeration.
  54  *
  55  * - Then, after a SET_CONFIGURATION control request, ep_config() is
  56  *   called when each /dev/gadget/ep* file is configured (by writing
  57  *   endpoint descriptors).  Afterwards these files are used to write()
  58  *   IN data or to read() OUT data.  To halt the endpoint, a "wrong
  59  *   direction" request is issued (like reading an IN endpoint).
  60  *
  61  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
  62  * not possible on all hardware.  For example, precise fault handling with
  63  * respect to data left in endpoint fifos after aborted operations; or
  64  * selective clearing of endpoint halts, to implement SET_INTERFACE.
  65  */
  66
  67 #define DRIVER_DESC     "USB Gadget filesystem"
  68 #define DRIVER_VERSION  "24 Aug 2004"
  69
  70 static const char driver_desc [] = DRIVER_DESC;
  71 static const char shortname [] = "gadgetfs";
  72
  73 MODULE_DESCRIPTION (DRIVER_DESC);
  74 MODULE_AUTHOR ("David Brownell");
  75 MODULE_LICENSE ("GPL");
  76
  77
  78 /*----------------------------------------------------------------------*/
  79
  80 #define GADGETFS_MAGIC          0xaee71ee7
  81
  82 /* /dev/gadget/$CHIP represents ep0 and the whole device */
  83 enum ep0_state {
  84         /* DISBLED is the initial state.
  85          */
  86         STATE_DEV_DISABLED = 0,
  87
  88         /* Only one open() of /dev/gadget/$CHIP; only one file tracks
  89          * ep0/device i/o modes and binding to the controller.  Driver
  90          * must always write descriptors to initialize the device, then
  91          * the device becomes UNCONNECTED until enumeration.
  92          */
  93         STATE_DEV_OPENED,
  94
  95         /* From then on, ep0 fd is in either of two basic modes:
  96          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
  97          * - SETUP: read/write will transfer control data and succeed;
  98          *   or if "wrong direction", performs protocol stall
  99          */
 100         STATE_DEV_UNCONNECTED,
 101         STATE_DEV_CONNECTED,
 102         STATE_DEV_SETUP,
 103
 104         /* UNBOUND means the driver closed ep0, so the device won't be
 105          * accessible again (DEV_DISABLED) until all fds are closed.
 106          */
 107         STATE_DEV_UNBOUND,
 108 };
 109
 110 /* enough for the whole queue: most events invalidate others */
 111 #define N_EVENT                 5
 112
 113 struct dev_data {
 114         spinlock_t                      lock;
 115         atomic_t                        count;
 116         enum ep0_state                  state;          /* P: lock */
 117         struct usb_gadgetfs_event       event [N_EVENT];
 118         unsigned                        ev_next;
 119         struct fasync_struct            *fasync;
 120         u8                              current_config;
 121
 122         /* drivers reading ep0 MUST handle control requests (SETUP)
 123          * reported that way; else the host will time out.
 124          */
 125         unsigned                        usermode_setup : 1,
 126                                         setup_in : 1,
 127                                         setup_can_stall : 1,
 128                                         setup_out_ready : 1,
 129                                         setup_out_error : 1,
 130                                         setup_abort : 1;
 131         unsigned                        setup_wLength;
 132
 133         /* the rest is basically write-once */
 134         struct usb_config_descriptor    *config, *hs_config;
 135         struct usb_device_descriptor    *dev;
 136         struct usb_request              *req;
 137         struct usb_gadget               *gadget;
 138         struct list_head                epfiles;
 139         void                            *buf;
 140         wait_queue_head_t               wait;
 141         struct super_block              *sb;
 142         struct dentry                   *dentry;
 143
 144         /* except this scratch i/o buffer for ep0 */
 145         u8                              rbuf [256];
 146 };
 147
 148 static inline void get_dev (struct dev_data *data)
 149 {
 150         atomic_inc (&data->count);
 151 }
 152
 153 static void put_dev (struct dev_data *data)
 154 {
 155         if (likely (!atomic_dec_and_test (&data->count)))
 156                 return;
 157         /* needs no more cleanup */
 158         BUG_ON (waitqueue_active (&data->wait));
 159         kfree (data);
 160 }
 161
 162 static struct dev_data *dev_new (void)
 163 {
 164         struct dev_data         *dev;
 165
 166         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 167         if (!dev)
 168                 return NULL;
 169         dev->state = STATE_DEV_DISABLED;
 170         atomic_set (&dev->count, 1);
 171         spin_lock_init (&dev->lock);
 172         INIT_LIST_HEAD (&dev->epfiles);
 173         init_waitqueue_head (&dev->wait);
 174         return dev;
 175 }
 176
 177 /*----------------------------------------------------------------------*/
 178
 179 /* other /dev/gadget/$ENDPOINT files represent endpoints */
 180 enum ep_state {
 181         STATE_EP_DISABLED = 0,
 182         STATE_EP_READY,
 183         STATE_EP_ENABLED,
 184         STATE_EP_UNBOUND,
 185 };
 186
 187 struct ep_data {
 188         struct mutex                    lock;
 189         enum ep_state                   state;
 190         atomic_t                        count;
 191         struct dev_data                 *dev;
 192         /* must hold dev->lock before accessing ep or req */
 193         struct usb_ep                   *ep;
 194         struct usb_request              *req;
 195         ssize_t                         status;
 196         char                            name [16];
 197         struct usb_endpoint_descriptor  desc, hs_desc;
 198         struct list_head                epfiles;
 199         wait_queue_head_t               wait;
 200         struct dentry                   *dentry;
 201         struct inode                    *inode;
 202 };
 203
 204 static inline void get_ep (struct ep_data *data)
 205 {
 206         atomic_inc (&data->count);
 207 }
 208
 209 static void put_ep (struct ep_data *data)
 210 {
 211         if (likely (!atomic_dec_and_test (&data->count)))
 212                 return;
 213         put_dev (data->dev);
 214         /* needs no more cleanup */
 215         BUG_ON (!list_empty (&data->epfiles));
 216         BUG_ON (waitqueue_active (&data->wait));
 217         kfree (data);
 218 }
 219
 220 /*----------------------------------------------------------------------*/
 221
 222 /* most "how to use the hardware" policy choices are in userspace:
 223  * mapping endpoint roles (which the driver needs) to the capabilities
 224  * which the usb controller has.  most of those capabilities are exposed
 225  * implicitly, starting with the driver name and then endpoint names.
 226  */
 227
 228 static const char *CHIP;
 229
 230 /*----------------------------------------------------------------------*/
 231
 232 /* NOTE:  don't use dev_printk calls before binding to the gadget
 233  * at the end of ep0 configuration, or after unbind.
 234  */
 235
 236 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
 237 #define xprintk(d,level,fmt,args...) \
 238         printk(level "%s: " fmt , shortname , ## args)
 239
 240 #ifdef DEBUG
 241 #define DBG(dev,fmt,args...) \
 242         xprintk(dev , KERN_DEBUG , fmt , ## args)
 243 #else
 244 #define DBG(dev,fmt,args...) \
 245         do { } while (0)
 246 #endif /* DEBUG */
 247
 248 #ifdef VERBOSE_DEBUG
 249 #define VDEBUG  DBG
 250 #else
 251 #define VDEBUG(dev,fmt,args...) \
 252         do { } while (0)
 253 #endif /* DEBUG */
 254
 255 #define ERROR(dev,fmt,args...) \
 256         xprintk(dev , KERN_ERR , fmt , ## args)
 257 #define INFO(dev,fmt,args...) \
 258         xprintk(dev , KERN_INFO , fmt , ## args)
 259
 260
 261 /*----------------------------------------------------------------------*/
 262
 263 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 264  *
 265  * After opening, configure non-control endpoints.  Then use normal
 266  * stream read() and write() requests; and maybe ioctl() to get more
 267  * precise FIFO status when recovering from cancellation.
 268  */
 269
 270 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 271 {
 272         struct ep_data  *epdata = ep->driver_data;
 273
 274         if (!req->context)
 275                 return;
 276         if (req->status)
 277                 epdata->status = req->status;
 278         else
 279                 epdata->status = req->actual;
 280         complete ((struct completion *)req->context);
 281 }
 282
 283 /* tasklock endpoint, returning when it's connected.
 284  * still need dev->lock to use epdata->ep.
 285  */
 286 static int
 287 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
 288 {
 289         int     val;
 290
 291         if (f_flags & O_NONBLOCK) {
 292                 if (!mutex_trylock(&epdata->lock))
 293                         goto nonblock;
 294                 if (epdata->state != STATE_EP_ENABLED) {
 295                         mutex_unlock(&epdata->lock);
 296 nonblock:
 297                         val = -EAGAIN;
 298                 } else
 299                         val = 0;
 300                 return val;
 301         }
 302
 303         val = mutex_lock_interruptible(&epdata->lock);
 304         if (val < 0)
 305                 return val;
 306
 307         switch (epdata->state) {
 308         case STATE_EP_ENABLED:
 309                 break;
 310         // case STATE_EP_DISABLED:              /* "can't happen" */
 311         // case STATE_EP_READY:                 /* "can't happen" */
 312         default:                                /* error! */
 313                 pr_debug ("%s: ep %p not available, state %d\n",
 314                                 shortname, epdata, epdata->state);
 315                 // FALLTHROUGH
 316         case STATE_EP_UNBOUND:                  /* clean disconnect */
 317                 val = -ENODEV;
 318                 mutex_unlock(&epdata->lock);
 319         }
 320         return val;
 321 }
 322
 323 static ssize_t
 324 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 325 {
 326         DECLARE_COMPLETION_ONSTACK (done);
 327         int value;
 328
 329         spin_lock_irq (&epdata->dev->lock);
 330         if (likely (epdata->ep != NULL)) {
 331                 struct usb_request      *req = epdata->req;
 332
 333                 req->context = &done;
 334                 req->complete = epio_complete;
 335                 req->buf = buf;
 336                 req->length = len;
 337                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 338         } else
 339                 value = -ENODEV;
 340         spin_unlock_irq (&epdata->dev->lock);
 341
 342         if (likely (value == 0)) {
 343                 value = wait_event_interruptible (done.wait, done.done);
 344                 if (value != 0) {
 345                         spin_lock_irq (&epdata->dev->lock);
 346                         if (likely (epdata->ep != NULL)) {
 347                                 DBG (epdata->dev, "%s i/o interrupted\n",
 348                                                 epdata->name);
 349                                 usb_ep_dequeue (epdata->ep, epdata->req);
 350                                 spin_unlock_irq (&epdata->dev->lock);
 351
 352                                 wait_event (done.wait, done.done);
 353                                 if (epdata->status == -ECONNRESET)
 354                                         epdata->status = -EINTR;
 355                         } else {
 356                                 spin_unlock_irq (&epdata->dev->lock);
 357
 358                                 DBG (epdata->dev, "endpoint gone\n");
 359                                 epdata->status = -ENODEV;
 360                         }
 361                 }
 362                 return epdata->status;
 363         }
 364         return value;
 365 }
 366
 367
 368 /* handle a synchronous OUT bulk/intr/iso transfer */
 369 static ssize_t
 370 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 371 {
 372         struct ep_data          *data = fd->private_data;
 373         void                    *kbuf;
 374         ssize_t                 value;
 375
 376         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 377                 return value;
 378
 379         /* halt any endpoint by doing a "wrong direction" i/o call */
 380         if (usb_endpoint_dir_in(&data->desc)) {
 381                 if (usb_endpoint_xfer_isoc(&data->desc)) {
 382                         mutex_unlock(&data->lock);
 383                         return -EINVAL;
 384                 }
 385                 DBG (data->dev, "%s halt\n", data->name);
 386                 spin_lock_irq (&data->dev->lock);
 387                 if (likely (data->ep != NULL))
 388                         usb_ep_set_halt (data->ep);
 389                 spin_unlock_irq (&data->dev->lock);
 390                 mutex_unlock(&data->lock);
 391                 return -EBADMSG;
 392         }
 393
 394         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
 395
 396         value = -ENOMEM;
 397         kbuf = kmalloc (len, GFP_KERNEL);
 398         if (unlikely (!kbuf))
 399                 goto free1;
 400
 401         value = ep_io (data, kbuf, len);
 402         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
 403                 data->name, len, (int) value);
 404         if (value >= 0 && copy_to_user (buf, kbuf, value))
 405                 value = -EFAULT;
 406
 407 free1:
 408         mutex_unlock(&data->lock);
 409         kfree (kbuf);
 410         return value;
 411 }
 412
 413 /* handle a synchronous IN bulk/intr/iso transfer */
 414 static ssize_t
 415 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 416 {
 417         struct ep_data          *data = fd->private_data;
 418         void                    *kbuf;
 419         ssize_t                 value;
 420
 421         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 422                 return value;
 423
 424         /* halt any endpoint by doing a "wrong direction" i/o call */
 425         if (!usb_endpoint_dir_in(&data->desc)) {
 426                 if (usb_endpoint_xfer_isoc(&data->desc)) {
 427                         mutex_unlock(&data->lock);
 428                         return -EINVAL;
 429                 }
 430                 DBG (data->dev, "%s halt\n", data->name);
 431                 spin_lock_irq (&data->dev->lock);
 432                 if (likely (data->ep != NULL))
 433                         usb_ep_set_halt (data->ep);
 434                 spin_unlock_irq (&data->dev->lock);
 435                 mutex_unlock(&data->lock);
 436                 return -EBADMSG;
 437         }
 438
 439         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
 440
 441         value = -ENOMEM;
 442         kbuf = memdup_user(buf, len);
 443         if (!kbuf) {
 444                 value = PTR_ERR(kbuf);
 445                 goto free1;
 446         }
 447
 448         value = ep_io (data, kbuf, len);
 449         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
 450                 data->name, len, (int) value);
 451 free1:
 452         mutex_unlock(&data->lock);
 453         return value;
 454 }
 455
 456 static int
 457 ep_release (struct inode *inode, struct file *fd)
 458 {
 459         struct ep_data          *data = fd->private_data;
 460         int value;
 461
 462         value = mutex_lock_interruptible(&data->lock);
 463         if (value < 0)
 464                 return value;
 465
 466         /* clean up if this can be reopened */
 467         if (data->state != STATE_EP_UNBOUND) {
 468                 data->state = STATE_EP_DISABLED;
 469                 data->desc.bDescriptorType = 0;
 470                 data->hs_desc.bDescriptorType = 0;
 471                 usb_ep_disable(data->ep);
 472         }
 473         mutex_unlock(&data->lock);
 474         put_ep (data);
 475         return 0;
 476 }
 477
 478 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
 479 {
 480         struct ep_data          *data = fd->private_data;
 481         int                     status;
 482
 483         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 484                 return status;
 485
 486         spin_lock_irq (&data->dev->lock);
 487         if (likely (data->ep != NULL)) {
 488                 switch (code) {
 489                 case GADGETFS_FIFO_STATUS:
 490                         status = usb_ep_fifo_status (data->ep);
 491                         break;
 492                 case GADGETFS_FIFO_FLUSH:
 493                         usb_ep_fifo_flush (data->ep);
 494                         break;
 495                 case GADGETFS_CLEAR_HALT:
 496                         status = usb_ep_clear_halt (data->ep);
 497                         break;
 498                 default:
 499                         status = -ENOTTY;
 500                 }
 501         } else
 502                 status = -ENODEV;
 503         spin_unlock_irq (&data->dev->lock);
 504         mutex_unlock(&data->lock);
 505         return status;
 506 }
 507
 508 /*----------------------------------------------------------------------*/
 509
 510 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 511
 512 struct kiocb_priv {
 513         struct usb_request      *req;
 514         struct ep_data          *epdata;
 515         struct kiocb            *iocb;
 516         struct mm_struct        *mm;
 517         struct work_struct      work;
 518         void                    *buf;
 519         const struct iovec      *iv;
 520         unsigned long           nr_segs;
 521         unsigned                actual;
 522 };
 523
 524 static int ep_aio_cancel(struct kiocb *iocb)
 525 {
 526         struct kiocb_priv       *priv = iocb->private;
 527         struct ep_data          *epdata;
 528         int                     value;
 529
 530         local_irq_disable();
 531         epdata = priv->epdata;
 532         // spin_lock(&epdata->dev->lock);
 533         if (likely(epdata && epdata->ep && priv->req))
 534                 value = usb_ep_dequeue (epdata->ep, priv->req);
 535         else
 536                 value = -EINVAL;
 537         // spin_unlock(&epdata->dev->lock);
 538         local_irq_enable();
 539
 540         return value;
 541 }
 542
 543 static ssize_t ep_copy_to_user(struct kiocb_priv *priv)
 544 {
 545         ssize_t                 len, total;
 546         void                    *to_copy;
 547         int                     i;
 548
 549         /* copy stuff into user buffers */
 550         total = priv->actual;
 551         len = 0;
 552         to_copy = priv->buf;
 553         for (i=0; i < priv->nr_segs; i++) {
 554                 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
 555
 556                 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
 557                         if (len == 0)
 558                                 len = -EFAULT;
 559                         break;
 560                 }
 561
 562                 total -= this;
 563                 len += this;
 564                 to_copy += this;
 565                 if (total == 0)
 566                         break;
 567         }
 568
 569         return len;
 570 }
 571
 572 static void ep_user_copy_worker(struct work_struct *work)
 573 {
 574         struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work);
 575         struct mm_struct *mm = priv->mm;
 576         struct kiocb *iocb = priv->iocb;
 577         size_t ret;
 578
 579         use_mm(mm);
 580         ret = ep_copy_to_user(priv);
 581         unuse_mm(mm);
 582
 583         /* completing the iocb can drop the ctx and mm, don't touch mm after */
 584         aio_complete(iocb, ret, ret);
 585
 586         kfree(priv->buf);
 587         kfree(priv);
 588 }
 589
 590 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 591 {
 592         struct kiocb            *iocb = req->context;
 593         struct kiocb_priv       *priv = iocb->private;
 594         struct ep_data          *epdata = priv->epdata;
 595
 596         /* lock against disconnect (and ideally, cancel) */
 597         spin_lock(&epdata->dev->lock);
 598         priv->req = NULL;
 599         priv->epdata = NULL;
 600
 601         /* if this was a write or a read returning no data then we
 602          * don't need to copy anything to userspace, so we can
 603          * complete the aio request immediately.
 604          */
 605         if (priv->iv == NULL || unlikely(req->actual == 0)) {
 606                 kfree(req->buf);
 607                 kfree(priv);
 608                 iocb->private = NULL;
 609                 /* aio_complete() reports bytes-transferred _and_ faults */
 610                 aio_complete(iocb, req->actual ? req->actual : req->status,
 611                                 req->status);
 612         } else {
 613                 /* ep_copy_to_user() won't report both; we hide some faults */
 614                 if (unlikely(0 != req->status))
 615                         DBG(epdata->dev, "%s fault %d len %d\n",
 616                                 ep->name, req->status, req->actual);
 617
 618                 priv->buf = req->buf;
 619                 priv->actual = req->actual;
 620                 schedule_work(&priv->work);
 621         }
 622         spin_unlock(&epdata->dev->lock);
 623
 624         usb_ep_free_request(ep, req);
 625         put_ep(epdata);
 626 }
 627
 628 static ssize_t
 629 ep_aio_rwtail(
 630         struct kiocb    *iocb,
 631         char            *buf,
 632         size_t          len,
 633         struct ep_data  *epdata,
 634         const struct iovec *iv,
 635         unsigned long   nr_segs
 636 )
 637 {
 638         struct kiocb_priv       *priv;
 639         struct usb_request      *req;
 640         ssize_t                 value;
 641
 642         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 643         if (!priv) {
 644                 value = -ENOMEM;
 645 fail:
 646                 kfree(buf);
 647                 return value;
 648         }
 649         iocb->private = priv;
 650         priv->iocb = iocb;
 651         priv->iv = iv;
 652         priv->nr_segs = nr_segs;
 653         INIT_WORK(&priv->work, ep_user_copy_worker);
 654
 655         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 656         if (unlikely(value < 0)) {
 657                 kfree(priv);
 658                 goto fail;
 659         }
 660
 661         kiocb_set_cancel_fn(iocb, ep_aio_cancel);
 662         get_ep(epdata);
 663         priv->epdata = epdata;
 664         priv->actual = 0;
 665         priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */
 666
 667         /* each kiocb is coupled to one usb_request, but we can't
 668          * allocate or submit those if the host disconnected.
 669          */
 670         spin_lock_irq(&epdata->dev->lock);
 671         if (likely(epdata->ep)) {
 672                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 673                 if (likely(req)) {
 674                         priv->req = req;
 675                         req->buf = buf;
 676                         req->length = len;
 677                         req->complete = ep_aio_complete;
 678                         req->context = iocb;
 679                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 680                         if (unlikely(0 != value))
 681                                 usb_ep_free_request(epdata->ep, req);
 682                 } else
 683                         value = -EAGAIN;
 684         } else
 685                 value = -ENODEV;
 686         spin_unlock_irq(&epdata->dev->lock);
 687
 688         mutex_unlock(&epdata->lock);
 689
 690         if (unlikely(value)) {
 691                 kfree(priv);
 692                 put_ep(epdata);
 693         } else
 694                 value = -EIOCBQUEUED;
 695         return value;
 696 }
 697
 698 static ssize_t
 699 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
 700                 unsigned long nr_segs, loff_t o)
 701 {
 702         struct ep_data          *epdata = iocb->ki_filp->private_data;
 703         char                    *buf;
 704
 705         if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
 706                 return -EINVAL;
 707
 708         buf = kmalloc(iocb->ki_nbytes, GFP_KERNEL);
 709         if (unlikely(!buf))
 710                 return -ENOMEM;
 711
 712         return ep_aio_rwtail(iocb, buf, iocb->ki_nbytes, epdata, iov, nr_segs);
 713 }
 714
 715 static ssize_t
 716 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
 717                 unsigned long nr_segs, loff_t o)
 718 {
 719         struct ep_data          *epdata = iocb->ki_filp->private_data;
 720         char                    *buf;
 721         size_t                  len = 0;
 722         int                     i = 0;
 723
 724         if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
 725                 return -EINVAL;
 726
 727         buf = kmalloc(iocb->ki_nbytes, GFP_KERNEL);
 728         if (unlikely(!buf))
 729                 return -ENOMEM;
 730
 731         for (i=0; i < nr_segs; i++) {
 732                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
 733                                 iov[i].iov_len) != 0)) {
 734                         kfree(buf);
 735                         return -EFAULT;
 736                 }
 737                 len += iov[i].iov_len;
 738         }
 739         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
 740 }
 741
 742 /*----------------------------------------------------------------------*/
 743
 744 /* used after endpoint configuration */
 745 static const struct file_operations ep_io_operations = {
 746         .owner =        THIS_MODULE,
 747         .llseek =       no_llseek,
 748
 749         .read =         ep_read,
 750         .write =        ep_write,
 751         .unlocked_ioctl = ep_ioctl,
 752         .release =      ep_release,
 753
 754         .aio_read =     ep_aio_read,
 755         .aio_write =    ep_aio_write,
 756 };
 757
 758 /* ENDPOINT INITIALIZATION
 759  *
 760  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 761  *     status = write (fd, descriptors, sizeof descriptors)
 762  *
 763  * That write establishes the endpoint configuration, configuring
 764  * the controller to process bulk, interrupt, or isochronous transfers
 765  * at the right maxpacket size, and so on.
 766  *
 767  * The descriptors are message type 1, identified by a host order u32
 768  * at the beginning of what's written.  Descriptor order is: full/low
 769  * speed descriptor, then optional high speed descriptor.
 770  */
 771 static ssize_t
 772 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 773 {
 774         struct ep_data          *data = fd->private_data;
 775         struct usb_ep           *ep;
 776         u32                     tag;
 777         int                     value, length = len;
 778
 779         value = mutex_lock_interruptible(&data->lock);
 780         if (value < 0)
 781                 return value;
 782
 783         if (data->state != STATE_EP_READY) {
 784                 value = -EL2HLT;
 785                 goto fail;
 786         }
 787
 788         value = len;
 789         if (len < USB_DT_ENDPOINT_SIZE + 4)
 790                 goto fail0;
 791
 792         /* we might need to change message format someday */
 793         if (copy_from_user (&tag, buf, 4)) {
 794                 goto fail1;
 795         }
 796         if (tag != 1) {
 797                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 798                 goto fail0;
 799         }
 800         buf += 4;
 801         len -= 4;
 802
 803         /* NOTE:  audio endpoint extensions not accepted here;
 804          * just don't include the extra bytes.
 805          */
 806
 807         /* full/low speed descriptor, then high speed */
 808         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 809                 goto fail1;
 810         }
 811         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 812                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 813                 goto fail0;
 814         if (len != USB_DT_ENDPOINT_SIZE) {
 815                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 816                         goto fail0;
 817                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 818                                         USB_DT_ENDPOINT_SIZE)) {
 819                         goto fail1;
 820                 }
 821                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 822                                 || data->hs_desc.bDescriptorType
 823                                         != USB_DT_ENDPOINT) {
 824                         DBG(data->dev, "config %s, bad hs length or type\n",
 825                                         data->name);
 826                         goto fail0;
 827                 }
 828         }
 829
 830         spin_lock_irq (&data->dev->lock);
 831         if (data->dev->state == STATE_DEV_UNBOUND) {
 832                 value = -ENOENT;
 833                 goto gone;
 834         } else if ((ep = data->ep) == NULL) {
 835                 value = -ENODEV;
 836                 goto gone;
 837         }
 838         switch (data->dev->gadget->speed) {
 839         case USB_SPEED_LOW:
 840         case USB_SPEED_FULL:
 841                 ep->desc = &data->desc;
 842                 value = usb_ep_enable(ep);
 843                 if (value == 0)
 844                         data->state = STATE_EP_ENABLED;
 845                 break;
 846         case USB_SPEED_HIGH:
 847                 /* fails if caller didn't provide that descriptor... */
 848                 ep->desc = &data->hs_desc;
 849                 value = usb_ep_enable(ep);
 850                 if (value == 0)
 851                         data->state = STATE_EP_ENABLED;
 852                 break;
 853         default:
 854                 DBG(data->dev, "unconnected, %s init abandoned\n",
 855                                 data->name);
 856                 value = -EINVAL;
 857         }
 858         if (value == 0) {
 859                 fd->f_op = &ep_io_operations;
 860                 value = length;
 861         }
 862 gone:
 863         spin_unlock_irq (&data->dev->lock);
 864         if (value < 0) {
 865 fail:
 866                 data->desc.bDescriptorType = 0;
 867                 data->hs_desc.bDescriptorType = 0;
 868         }
 869         mutex_unlock(&data->lock);
 870         return value;
 871 fail0:
 872         value = -EINVAL;
 873         goto fail;
 874 fail1:
 875         value = -EFAULT;
 876         goto fail;
 877 }
 878
 879 static int
 880 ep_open (struct inode *inode, struct file *fd)
 881 {
 882         struct ep_data          *data = inode->i_private;
 883         int                     value = -EBUSY;
 884
 885         if (mutex_lock_interruptible(&data->lock) != 0)
 886                 return -EINTR;
 887         spin_lock_irq (&data->dev->lock);
 888         if (data->dev->state == STATE_DEV_UNBOUND)
 889                 value = -ENOENT;
 890         else if (data->state == STATE_EP_DISABLED) {
 891                 value = 0;
 892                 data->state = STATE_EP_READY;
 893                 get_ep (data);
 894                 fd->private_data = data;
 895                 VDEBUG (data->dev, "%s ready\n", data->name);
 896         } else
 897                 DBG (data->dev, "%s state %d\n",
 898                         data->name, data->state);
 899         spin_unlock_irq (&data->dev->lock);
 900         mutex_unlock(&data->lock);
 901         return value;
 902 }
 903
 904 /* used before endpoint configuration */
 905 static const struct file_operations ep_config_operations = {
 906         .llseek =       no_llseek,
 907
 908         .open =         ep_open,
 909         .write =        ep_config,
 910         .release =      ep_release,
 911 };
 912
 913 /*----------------------------------------------------------------------*/
 914
 915 /* EP0 IMPLEMENTATION can be partly in userspace.
 916  *
 917  * Drivers that use this facility receive various events, including
 918  * control requests the kernel doesn't handle.  Drivers that don't
 919  * use this facility may be too simple-minded for real applications.
 920  */
 921
 922 static inline void ep0_readable (struct dev_data *dev)
 923 {
 924         wake_up (&dev->wait);
 925         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 926 }
 927
 928 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 929 {
 930         struct dev_data         *dev = ep->driver_data;
 931
 932         if (req->buf != dev->rbuf) {
 933                 kfree(req->buf);
 934                 req->buf = dev->rbuf;
 935         }
 936         req->complete = epio_complete;
 937         dev->setup_out_ready = 0;
 938 }
 939
 940 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 941 {
 942         struct dev_data         *dev = ep->driver_data;
 943         unsigned long           flags;
 944         int                     free = 1;
 945
 946         /* for control OUT, data must still get to userspace */
 947         spin_lock_irqsave(&dev->lock, flags);
 948         if (!dev->setup_in) {
 949                 dev->setup_out_error = (req->status != 0);
 950                 if (!dev->setup_out_error)
 951                         free = 0;
 952                 dev->setup_out_ready = 1;
 953                 ep0_readable (dev);
 954         }
 955
 956         /* clean up as appropriate */
 957         if (free && req->buf != &dev->rbuf)
 958                 clean_req (ep, req);
 959         req->complete = epio_complete;
 960         spin_unlock_irqrestore(&dev->lock, flags);
 961 }
 962
 963 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 964 {
 965         struct dev_data *dev = ep->driver_data;
 966
 967         if (dev->setup_out_ready) {
 968                 DBG (dev, "ep0 request busy!\n");
 969                 return -EBUSY;
 970         }
 971         if (len > sizeof (dev->rbuf))
 972                 req->buf = kmalloc(len, GFP_ATOMIC);
 973         if (req->buf == NULL) {
 974                 req->buf = dev->rbuf;
 975                 return -ENOMEM;
 976         }
 977         req->complete = ep0_complete;
 978         req->length = len;
 979         req->zero = 0;
 980         return 0;
 981 }
 982
 983 static ssize_t
 984 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 985 {
 986         struct dev_data                 *dev = fd->private_data;
 987         ssize_t                         retval;
 988         enum ep0_state                  state;
 989
 990         spin_lock_irq (&dev->lock);
 991
 992         /* report fd mode change before acting on it */
 993         if (dev->setup_abort) {
 994                 dev->setup_abort = 0;
 995                 retval = -EIDRM;
 996                 goto done;
 997         }
 998
 999         /* control DATA stage */
1000         if ((state = dev->state) == STATE_DEV_SETUP) {
1001
1002                 if (dev->setup_in) {            /* stall IN */
1003                         VDEBUG(dev, "ep0in stall\n");
1004                         (void) usb_ep_set_halt (dev->gadget->ep0);
1005                         retval = -EL2HLT;
1006                         dev->state = STATE_DEV_CONNECTED;
1007
1008                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
1009                         struct usb_ep           *ep = dev->gadget->ep0;
1010                         struct usb_request      *req = dev->req;
1011
1012                         if ((retval = setup_req (ep, req, 0)) == 0)
1013                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1014                         dev->state = STATE_DEV_CONNECTED;
1015
1016                         /* assume that was SET_CONFIGURATION */
1017                         if (dev->current_config) {
1018                                 unsigned power;
1019
1020                                 if (gadget_is_dualspeed(dev->gadget)
1021                                                 && (dev->gadget->speed
1022                                                         == USB_SPEED_HIGH))
1023                                         power = dev->hs_config->bMaxPower;
1024                                 else
1025                                         power = dev->config->bMaxPower;
1026                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1027                         }
1028
1029                 } else {                        /* collect OUT data */
1030                         if ((fd->f_flags & O_NONBLOCK) != 0
1031                                         && !dev->setup_out_ready) {
1032                                 retval = -EAGAIN;
1033                                 goto done;
1034                         }
1035                         spin_unlock_irq (&dev->lock);
1036                         retval = wait_event_interruptible (dev->wait,
1037                                         dev->setup_out_ready != 0);
1038
1039                         /* FIXME state could change from under us */
1040                         spin_lock_irq (&dev->lock);
1041                         if (retval)
1042                                 goto done;
1043
1044                         if (dev->state != STATE_DEV_SETUP) {
1045                                 retval = -ECANCELED;
1046                                 goto done;
1047                         }
1048                         dev->state = STATE_DEV_CONNECTED;
1049
1050                         if (dev->setup_out_error)
1051                                 retval = -EIO;
1052                         else {
1053                                 len = min (len, (size_t)dev->req->actual);
1054 // FIXME don't call this with the spinlock held ...
1055                                 if (copy_to_user (buf, dev->req->buf, len))
1056                                         retval = -EFAULT;
1057                                 else
1058                                         retval = len;
1059                                 clean_req (dev->gadget->ep0, dev->req);
1060                                 /* NOTE userspace can't yet choose to stall */
1061                         }
1062                 }
1063                 goto done;
1064         }
1065
1066         /* else normal: return event data */
1067         if (len < sizeof dev->event [0]) {
1068                 retval = -EINVAL;
1069                 goto done;
1070         }
1071         len -= len % sizeof (struct usb_gadgetfs_event);
1072         dev->usermode_setup = 1;
1073
1074 scan:
1075         /* return queued events right away */
1076         if (dev->ev_next != 0) {
1077                 unsigned                i, n;
1078
1079                 n = len / sizeof (struct usb_gadgetfs_event);
1080                 if (dev->ev_next < n)
1081                         n = dev->ev_next;
1082
1083                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1084                 for (i = 0; i < n; i++) {
1085                         if (dev->event [i].type == GADGETFS_SETUP) {
1086                                 dev->state = STATE_DEV_SETUP;
1087                                 n = i + 1;
1088                                 break;
1089                         }
1090                 }
1091                 spin_unlock_irq (&dev->lock);
1092                 len = n * sizeof (struct usb_gadgetfs_event);
1093                 if (copy_to_user (buf, &dev->event, len))
1094                         retval = -EFAULT;
1095                 else
1096                         retval = len;
1097                 if (len > 0) {
1098                         /* NOTE this doesn't guard against broken drivers;
1099                          * concurrent ep0 readers may lose events.
1100                          */
1101                         spin_lock_irq (&dev->lock);
1102                         if (dev->ev_next > n) {
1103                                 memmove(&dev->event[0], &dev->event[n],
1104                                         sizeof (struct usb_gadgetfs_event)
1105                                                 * (dev->ev_next - n));
1106                         }
1107                         dev->ev_next -= n;
1108                         spin_unlock_irq (&dev->lock);
1109                 }
1110                 return retval;
1111         }
1112         if (fd->f_flags & O_NONBLOCK) {
1113                 retval = -EAGAIN;
1114                 goto done;
1115         }
1116
1117         switch (state) {
1118         default:
1119                 DBG (dev, "fail %s, state %d\n", __func__, state);
1120                 retval = -ESRCH;
1121                 break;
1122         case STATE_DEV_UNCONNECTED:
1123         case STATE_DEV_CONNECTED:
1124                 spin_unlock_irq (&dev->lock);
1125                 DBG (dev, "%s wait\n", __func__);
1126
1127                 /* wait for events */
1128                 retval = wait_event_interruptible (dev->wait,
1129                                 dev->ev_next != 0);
1130                 if (retval < 0)
1131                         return retval;
1132                 spin_lock_irq (&dev->lock);
1133                 goto scan;
1134         }
1135
1136 done:
1137         spin_unlock_irq (&dev->lock);
1138         return retval;
1139 }
1140
1141 static struct usb_gadgetfs_event *
1142 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1143 {
1144         struct usb_gadgetfs_event       *event;
1145         unsigned                        i;
1146
1147         switch (type) {
1148         /* these events purge the queue */
1149         case GADGETFS_DISCONNECT:
1150                 if (dev->state == STATE_DEV_SETUP)
1151                         dev->setup_abort = 1;
1152                 // FALL THROUGH
1153         case GADGETFS_CONNECT:
1154                 dev->ev_next = 0;
1155                 break;
1156         case GADGETFS_SETUP:            /* previous request timed out */
1157         case GADGETFS_SUSPEND:          /* same effect */
1158                 /* these events can't be repeated */
1159                 for (i = 0; i != dev->ev_next; i++) {
1160                         if (dev->event [i].type != type)
1161                                 continue;
1162                         DBG(dev, "discard old event[%d] %d\n", i, type);
1163                         dev->ev_next--;
1164                         if (i == dev->ev_next)
1165                                 break;
1166                         /* indices start at zero, for simplicity */
1167                         memmove (&dev->event [i], &dev->event [i + 1],
1168                                 sizeof (struct usb_gadgetfs_event)
1169                                         * (dev->ev_next - i));
1170                 }
1171                 break;
1172         default:
1173                 BUG ();
1174         }
1175         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1176         event = &dev->event [dev->ev_next++];
1177         BUG_ON (dev->ev_next > N_EVENT);
1178         memset (event, 0, sizeof *event);
1179         event->type = type;
1180         return event;
1181 }
1182
1183 static ssize_t
1184 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1185 {
1186         struct dev_data         *dev = fd->private_data;
1187         ssize_t                 retval = -ESRCH;
1188
1189         spin_lock_irq (&dev->lock);
1190
1191         /* report fd mode change before acting on it */
1192         if (dev->setup_abort) {
1193                 dev->setup_abort = 0;
1194                 retval = -EIDRM;
1195
1196         /* data and/or status stage for control request */
1197         } else if (dev->state == STATE_DEV_SETUP) {
1198
1199                 /* IN DATA+STATUS caller makes len <= wLength */
1200                 if (dev->setup_in) {
1201                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1202                         if (retval == 0) {
1203                                 dev->state = STATE_DEV_CONNECTED;
1204                                 spin_unlock_irq (&dev->lock);
1205                                 if (copy_from_user (dev->req->buf, buf, len))
1206                                         retval = -EFAULT;
1207                                 else {
1208                                         if (len < dev->setup_wLength)
1209                                                 dev->req->zero = 1;
1210                                         retval = usb_ep_queue (
1211                                                 dev->gadget->ep0, dev->req,
1212                                                 GFP_KERNEL);
1213                                 }
1214                                 if (retval < 0) {
1215                                         spin_lock_irq (&dev->lock);
1216                                         clean_req (dev->gadget->ep0, dev->req);
1217                                         spin_unlock_irq (&dev->lock);
1218                                 } else
1219                                         retval = len;
1220
1221                                 return retval;
1222                         }
1223
1224                 /* can stall some OUT transfers */
1225                 } else if (dev->setup_can_stall) {
1226                         VDEBUG(dev, "ep0out stall\n");
1227                         (void) usb_ep_set_halt (dev->gadget->ep0);
1228                         retval = -EL2HLT;
1229                         dev->state = STATE_DEV_CONNECTED;
1230                 } else {
1231                         DBG(dev, "bogus ep0out stall!\n");
1232                 }
1233         } else
1234                 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1235
1236         spin_unlock_irq (&dev->lock);
1237         return retval;
1238 }
1239
1240 static int
1241 ep0_fasync (int f, struct file *fd, int on)
1242 {
1243         struct dev_data         *dev = fd->private_data;
1244         // caller must F_SETOWN before signal delivery happens
1245         VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1246         return fasync_helper (f, fd, on, &dev->fasync);
1247 }
1248
1249 static struct usb_gadget_driver gadgetfs_driver;
1250
1251 static int
1252 dev_release (struct inode *inode, struct file *fd)
1253 {
1254         struct dev_data         *dev = fd->private_data;
1255
1256         /* closing ep0 === shutdown all */
1257
1258         usb_gadget_unregister_driver (&gadgetfs_driver);
1259
1260         /* at this point "good" hardware has disconnected the
1261          * device from USB; the host won't see it any more.
1262          * alternatively, all host requests will time out.
1263          */
1264
1265         kfree (dev->buf);
1266         dev->buf = NULL;
1267         put_dev (dev);
1268
1269         return 0;
1270 }
1271
1272 static unsigned int
1273 ep0_poll (struct file *fd, poll_table *wait)
1274 {
1275        struct dev_data         *dev = fd->private_data;
1276        int                     mask = 0;
1277
1278        poll_wait(fd, &dev->wait, wait);
1279
1280        spin_lock_irq (&dev->lock);
1281
1282        /* report fd mode change before acting on it */
1283        if (dev->setup_abort) {
1284                dev->setup_abort = 0;
1285                mask = POLLHUP;
1286                goto out;
1287        }
1288
1289        if (dev->state == STATE_DEV_SETUP) {
1290                if (dev->setup_in || dev->setup_can_stall)
1291                        mask = POLLOUT;
1292        } else {
1293                if (dev->ev_next != 0)
1294                        mask = POLLIN;
1295        }
1296 out:
1297        spin_unlock_irq(&dev->lock);
1298        return mask;
1299 }
1300
1301 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1302 {
1303         struct dev_data         *dev = fd->private_data;
1304         struct usb_gadget       *gadget = dev->gadget;
1305         long ret = -ENOTTY;
1306
1307         if (gadget->ops->ioctl)
1308                 ret = gadget->ops->ioctl (gadget, code, value);
1309
1310         return ret;
1311 }
1312
1313 /* used after device configuration */
1314 static const struct file_operations ep0_io_operations = {
1315         .owner =        THIS_MODULE,
1316         .llseek =       no_llseek,
1317
1318         .read =         ep0_read,
1319         .write =        ep0_write,
1320         .fasync =       ep0_fasync,
1321         .poll =         ep0_poll,
1322         .unlocked_ioctl =       dev_ioctl,
1323         .release =      dev_release,
1324 };
1325
1326 /*----------------------------------------------------------------------*/
1327
1328 /* The in-kernel gadget driver handles most ep0 issues, in particular
1329  * enumerating the single configuration (as provided from user space).
1330  *
1331  * Unrecognized ep0 requests may be handled in user space.
1332  */
1333
1334 static void make_qualifier (struct dev_data *dev)
1335 {
1336         struct usb_qualifier_descriptor         qual;
1337         struct usb_device_descriptor            *desc;
1338
1339         qual.bLength = sizeof qual;
1340         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1341         qual.bcdUSB = cpu_to_le16 (0x0200);
1342
1343         desc = dev->dev;
1344         qual.bDeviceClass = desc->bDeviceClass;
1345         qual.bDeviceSubClass = desc->bDeviceSubClass;
1346         qual.bDeviceProtocol = desc->bDeviceProtocol;
1347
1348         /* assumes ep0 uses the same value for both speeds ... */
1349         qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1350
1351         qual.bNumConfigurations = 1;
1352         qual.bRESERVED = 0;
1353
1354         memcpy (dev->rbuf, &qual, sizeof qual);
1355 }
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
1406                 INFO (dev, "connected\n");
1407                 event = next_event (dev, GADGETFS_CONNECT);
1408                 event->u.speed = gadget->speed;
1409                 ep0_readable (dev);
1410
1411         /* host may have given up waiting for response.  we can miss control
1412          * requests handled lower down (device/endpoint status and features);
1413          * then ep0_{read,write} will report the wrong status. controller
1414          * driver will have aborted pending i/o.
1415          */
1416         } else if (dev->state == STATE_DEV_SETUP)
1417                 dev->setup_abort = 1;
1418
1419         req->buf = dev->rbuf;
1420         req->context = NULL;
1421         value = -EOPNOTSUPP;
1422         switch (ctrl->bRequest) {
1423
1424         case USB_REQ_GET_DESCRIPTOR:
1425                 if (ctrl->bRequestType != USB_DIR_IN)
1426                         goto unrecognized;
1427                 switch (w_value >> 8) {
1428
1429                 case USB_DT_DEVICE:
1430                         value = min (w_length, (u16) sizeof *dev->dev);
1431                         dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1432                         req->buf = dev->dev;
1433                         break;
1434                 case USB_DT_DEVICE_QUALIFIER:
1435                         if (!dev->hs_config)
1436                                 break;
1437                         value = min (w_length, (u16)
1438                                 sizeof (struct usb_qualifier_descriptor));
1439                         make_qualifier (dev);
1440                         break;
1441                 case USB_DT_OTHER_SPEED_CONFIG:
1442                         // FALLTHROUGH
1443                 case USB_DT_CONFIG:
1444                         value = config_buf (dev,
1445                                         w_value >> 8,
1446                                         w_value & 0xff);
1447                         if (value >= 0)
1448                                 value = min (w_length, (u16) value);
1449                         break;
1450                 case USB_DT_STRING:
1451                         goto unrecognized;
1452
1453                 default:                // all others are errors
1454                         break;
1455                 }
1456                 break;
1457
1458         /* currently one config, two speeds */
1459         case USB_REQ_SET_CONFIGURATION:
1460                 if (ctrl->bRequestType != 0)
1461                         goto unrecognized;
1462                 if (0 == (u8) w_value) {
1463                         value = 0;
1464                         dev->current_config = 0;
1465                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1466                         // user mode expected to disable endpoints
1467                 } else {
1468                         u8      config, power;
1469
1470                         if (gadget_is_dualspeed(gadget)
1471                                         && gadget->speed == USB_SPEED_HIGH) {
1472                                 config = dev->hs_config->bConfigurationValue;
1473                                 power = dev->hs_config->bMaxPower;
1474                         } else {
1475                                 config = dev->config->bConfigurationValue;
1476                                 power = dev->config->bMaxPower;
1477                         }
1478
1479                         if (config == (u8) w_value) {
1480                                 value = 0;
1481                                 dev->current_config = config;
1482                                 usb_gadget_vbus_draw(gadget, 2 * power);
1483                         }
1484                 }
1485
1486                 /* report SET_CONFIGURATION like any other control request,
1487                  * except that usermode may not stall this.  the next
1488                  * request mustn't be allowed start until this finishes:
1489                  * endpoints and threads set up, etc.
1490                  *
1491                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1492                  * has bad/racey automagic that prevents synchronizing here.
1493                  * even kernel mode drivers often miss them.
1494                  */
1495                 if (value == 0) {
1496                         INFO (dev, "configuration #%d\n", dev->current_config);
1497                         if (dev->usermode_setup) {
1498                                 dev->setup_can_stall = 0;
1499                                 goto delegate;
1500                         }
1501                 }
1502                 break;
1503
1504 #ifndef CONFIG_USB_GADGET_PXA25X
1505         /* PXA automagically handles this request too */
1506         case USB_REQ_GET_CONFIGURATION:
1507                 if (ctrl->bRequestType != 0x80)
1508                         goto unrecognized;
1509                 *(u8 *)req->buf = dev->current_config;
1510                 value = min (w_length, (u16) 1);
1511                 break;
1512 #endif
1513
1514         default:
1515 unrecognized:
1516                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1517                         dev->usermode_setup ? "delegate" : "fail",
1518                         ctrl->bRequestType, ctrl->bRequest,
1519                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1520
1521                 /* if there's an ep0 reader, don't stall */
1522                 if (dev->usermode_setup) {
1523                         dev->setup_can_stall = 1;
1524 delegate:
1525                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1526                                                 ? 1 : 0;
1527                         dev->setup_wLength = w_length;
1528                         dev->setup_out_ready = 0;
1529                         dev->setup_out_error = 0;
1530                         value = 0;
1531
1532                         /* read DATA stage for OUT right away */
1533                         if (unlikely (!dev->setup_in && w_length)) {
1534                                 value = setup_req (gadget->ep0, dev->req,
1535                                                         w_length);
1536                                 if (value < 0)
1537                                         break;
1538                                 value = usb_ep_queue (gadget->ep0, dev->req,
1539                                                         GFP_ATOMIC);
1540                                 if (value < 0) {
1541                                         clean_req (gadget->ep0, dev->req);
1542                                         break;
1543                                 }
1544
1545                                 /* we can't currently stall these */
1546                                 dev->setup_can_stall = 0;
1547                         }
1548
1549                         /* state changes when reader collects event */
1550                         event = next_event (dev, GADGETFS_SETUP);
1551                         event->u.setup = *ctrl;
1552                         ep0_readable (dev);
1553                         spin_unlock (&dev->lock);
1554                         return 0;
1555                 }
1556         }
1557
1558         /* proceed with data transfer and status phases? */
1559         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1560                 req->length = value;
1561                 req->zero = value < w_length;
1562                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1563                 if (value < 0) {
1564                         DBG (dev, "ep_queue --> %d\n", value);
1565                         req->status = 0;
1566                 }
1567         }
1568
1569         /* device stalls when value < 0 */
1570         spin_unlock (&dev->lock);
1571         return value;
1572 }
1573
1574 static void destroy_ep_files (struct dev_data *dev)
1575 {
1576         DBG (dev, "%s %d\n", __func__, dev->state);
1577
1578         /* dev->state must prevent interference */
1579         spin_lock_irq (&dev->lock);
1580         while (!list_empty(&dev->epfiles)) {
1581                 struct ep_data  *ep;
1582                 struct inode    *parent;
1583                 struct dentry   *dentry;
1584
1585                 /* break link to FS */
1586                 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1587                 list_del_init (&ep->epfiles);
1588                 dentry = ep->dentry;
1589                 ep->dentry = NULL;
1590                 parent = dentry->d_parent->d_inode;
1591
1592                 /* break link to controller */
1593                 if (ep->state == STATE_EP_ENABLED)
1594                         (void) usb_ep_disable (ep->ep);
1595                 ep->state = STATE_EP_UNBOUND;
1596                 usb_ep_free_request (ep->ep, ep->req);
1597                 ep->ep = NULL;
1598                 wake_up (&ep->wait);
1599                 put_ep (ep);
1600
1601                 spin_unlock_irq (&dev->lock);
1602
1603                 /* break link to dcache */
1604                 mutex_lock (&parent->i_mutex);
1605                 d_delete (dentry);
1606                 dput (dentry);
1607                 mutex_unlock (&parent->i_mutex);
1608
1609                 spin_lock_irq (&dev->lock);
1610         }
1611         spin_unlock_irq (&dev->lock);
1612 }
1613
1614
1615 static struct inode *
1616 gadgetfs_create_file (struct super_block *sb, char const *name,
1617                 void *data, const struct file_operations *fops,
1618                 struct dentry **dentry_p);
1619
1620 static int activate_ep_files (struct dev_data *dev)
1621 {
1622         struct usb_ep   *ep;
1623         struct ep_data  *data;
1624
1625         gadget_for_each_ep (ep, dev->gadget) {
1626
1627                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1628                 if (!data)
1629                         goto enomem0;
1630                 data->state = STATE_EP_DISABLED;
1631                 mutex_init(&data->lock);
1632                 init_waitqueue_head (&data->wait);
1633
1634                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1635                 atomic_set (&data->count, 1);
1636                 data->dev = dev;
1637                 get_dev (dev);
1638
1639                 data->ep = ep;
1640                 ep->driver_data = data;
1641
1642                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1643                 if (!data->req)
1644                         goto enomem1;
1645
1646                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1647                                 data, &ep_config_operations,
1648                                 &data->dentry);
1649                 if (!data->inode)
1650                         goto enomem2;
1651                 list_add_tail (&data->epfiles, &dev->epfiles);
1652         }
1653         return 0;
1654
1655 enomem2:
1656         usb_ep_free_request (ep, data->req);
1657 enomem1:
1658         put_dev (dev);
1659         kfree (data);
1660 enomem0:
1661         DBG (dev, "%s enomem\n", __func__);
1662         destroy_ep_files (dev);
1663         return -ENOMEM;
1664 }
1665
1666 static void
1667 gadgetfs_unbind (struct usb_gadget *gadget)
1668 {
1669         struct dev_data         *dev = get_gadget_data (gadget);
1670
1671         DBG (dev, "%s\n", __func__);
1672
1673         spin_lock_irq (&dev->lock);
1674         dev->state = STATE_DEV_UNBOUND;
1675         spin_unlock_irq (&dev->lock);
1676
1677         destroy_ep_files (dev);
1678         gadget->ep0->driver_data = NULL;
1679         set_gadget_data (gadget, NULL);
1680
1681         /* we've already been disconnected ... no i/o is active */
1682         if (dev->req)
1683                 usb_ep_free_request (gadget->ep0, dev->req);
1684         DBG (dev, "%s done\n", __func__);
1685         put_dev (dev);
1686 }
1687
1688 static struct dev_data          *the_device;
1689
1690 static int gadgetfs_bind(struct usb_gadget *gadget,
1691                 struct usb_gadget_driver *driver)
1692 {
1693         struct dev_data         *dev = the_device;
1694
1695         if (!dev)
1696                 return -ESRCH;
1697         if (0 != strcmp (CHIP, gadget->name)) {
1698                 pr_err("%s expected %s controller not %s\n",
1699                         shortname, CHIP, gadget->name);
1700                 return -ENODEV;
1701         }
1702
1703         set_gadget_data (gadget, dev);
1704         dev->gadget = gadget;
1705         gadget->ep0->driver_data = dev;
1706
1707         /* preallocate control response and buffer */
1708         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1709         if (!dev->req)
1710                 goto enomem;
1711         dev->req->context = NULL;
1712         dev->req->complete = epio_complete;
1713
1714         if (activate_ep_files (dev) < 0)
1715                 goto enomem;
1716
1717         INFO (dev, "bound to %s driver\n", gadget->name);
1718         spin_lock_irq(&dev->lock);
1719         dev->state = STATE_DEV_UNCONNECTED;
1720         spin_unlock_irq(&dev->lock);
1721         get_dev (dev);
1722         return 0;
1723
1724 enomem:
1725         gadgetfs_unbind (gadget);
1726         return -ENOMEM;
1727 }
1728
1729 static void
1730 gadgetfs_disconnect (struct usb_gadget *gadget)
1731 {
1732         struct dev_data         *dev = get_gadget_data (gadget);
1733         unsigned long           flags;
1734
1735         spin_lock_irqsave (&dev->lock, flags);
1736         if (dev->state == STATE_DEV_UNCONNECTED)
1737                 goto exit;
1738         dev->state = STATE_DEV_UNCONNECTED;
1739
1740         INFO (dev, "disconnected\n");
1741         next_event (dev, GADGETFS_DISCONNECT);
1742         ep0_readable (dev);
1743 exit:
1744         spin_unlock_irqrestore (&dev->lock, flags);
1745 }
1746
1747 static void
1748 gadgetfs_suspend (struct usb_gadget *gadget)
1749 {
1750         struct dev_data         *dev = get_gadget_data (gadget);
1751
1752         INFO (dev, "suspended from state %d\n", dev->state);
1753         spin_lock (&dev->lock);
1754         switch (dev->state) {
1755         case STATE_DEV_SETUP:           // VERY odd... host died??
1756         case STATE_DEV_CONNECTED:
1757         case STATE_DEV_UNCONNECTED:
1758                 next_event (dev, GADGETFS_SUSPEND);
1759                 ep0_readable (dev);
1760                 /* FALLTHROUGH */
1761         default:
1762                 break;
1763         }
1764         spin_unlock (&dev->lock);
1765 }
1766
1767 static struct usb_gadget_driver gadgetfs_driver = {
1768         .function       = (char *) driver_desc,
1769         .bind           = gadgetfs_bind,
1770         .unbind         = gadgetfs_unbind,
1771         .setup          = gadgetfs_setup,
1772         .disconnect     = gadgetfs_disconnect,
1773         .suspend        = gadgetfs_suspend,
1774
1775         .driver = {
1776                 .name           = (char *) shortname,
1777         },
1778 };
1779
1780 /*----------------------------------------------------------------------*/
1781
1782 static void gadgetfs_nop(struct usb_gadget *arg) { }
1783
1784 static int gadgetfs_probe(struct usb_gadget *gadget,
1785                 struct usb_gadget_driver *driver)
1786 {
1787         CHIP = gadget->name;
1788         return -EISNAM;
1789 }
1790
1791 static struct usb_gadget_driver probe_driver = {
1792         .max_speed      = USB_SPEED_HIGH,
1793         .bind           = gadgetfs_probe,
1794         .unbind         = gadgetfs_nop,
1795         .setup          = (void *)gadgetfs_nop,
1796         .disconnect     = gadgetfs_nop,
1797         .driver = {
1798                 .name           = "nop",
1799         },
1800 };
1801
1802
1803 /* DEVICE INITIALIZATION
1804  *
1805  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1806  *     status = write (fd, descriptors, sizeof descriptors)
1807  *
1808  * That write establishes the device configuration, so the kernel can
1809  * bind to the controller ... guaranteeing it can handle enumeration
1810  * at all necessary speeds.  Descriptor order is:
1811  *
1812  * . message tag (u32, host order) ... for now, must be zero; it
1813  *      would change to support features like multi-config devices
1814  * . full/low speed config ... all wTotalLength bytes (with interface,
1815  *      class, altsetting, endpoint, and other descriptors)
1816  * . high speed config ... all descriptors, for high speed operation;
1817  *      this one's optional except for high-speed hardware
1818  * . device descriptor
1819  *
1820  * Endpoints are not yet enabled. Drivers must wait until device
1821  * configuration and interface altsetting changes create
1822  * the need to configure (or unconfigure) them.
1823  *
1824  * After initialization, the device stays active for as long as that
1825  * $CHIP file is open.  Events must then be read from that descriptor,
1826  * such as configuration notifications.
1827  */
1828
1829 static int is_valid_config (struct usb_config_descriptor *config)
1830 {
1831         return config->bDescriptorType == USB_DT_CONFIG
1832                 && config->bLength == USB_DT_CONFIG_SIZE
1833                 && config->bConfigurationValue != 0
1834                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1835                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1836         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1837         /* FIXME check lengths: walk to end */
1838 }
1839
1840 static ssize_t
1841 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1842 {
1843         struct dev_data         *dev = fd->private_data;
1844         ssize_t                 value = len, length = len;
1845         unsigned                total;
1846         u32                     tag;
1847         char                    *kbuf;
1848
1849         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1850                 return -EINVAL;
1851
1852         /* we might need to change message format someday */
1853         if (copy_from_user (&tag, buf, 4))
1854                 return -EFAULT;
1855         if (tag != 0)
1856                 return -EINVAL;
1857         buf += 4;
1858         length -= 4;
1859
1860         kbuf = memdup_user(buf, length);
1861         if (IS_ERR(kbuf))
1862                 return PTR_ERR(kbuf);
1863
1864         spin_lock_irq (&dev->lock);
1865         value = -EINVAL;
1866         if (dev->buf)
1867                 goto fail;
1868         dev->buf = kbuf;
1869
1870         /* full or low speed config */
1871         dev->config = (void *) kbuf;
1872         total = le16_to_cpu(dev->config->wTotalLength);
1873         if (!is_valid_config (dev->config) || total >= length)
1874                 goto fail;
1875         kbuf += total;
1876         length -= total;
1877
1878         /* optional high speed config */
1879         if (kbuf [1] == USB_DT_CONFIG) {
1880                 dev->hs_config = (void *) kbuf;
1881                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1882                 if (!is_valid_config (dev->hs_config) || total >= length)
1883                         goto fail;
1884                 kbuf += total;
1885                 length -= total;
1886         }
1887
1888         /* could support multiple configs, using another encoding! */
1889
1890         /* device descriptor (tweaked for paranoia) */
1891         if (length != USB_DT_DEVICE_SIZE)
1892                 goto fail;
1893         dev->dev = (void *)kbuf;
1894         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1895                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1896                         || dev->dev->bNumConfigurations != 1)
1897                 goto fail;
1898         dev->dev->bNumConfigurations = 1;
1899         dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1900
1901         /* triggers gadgetfs_bind(); then we can enumerate. */
1902         spin_unlock_irq (&dev->lock);
1903         if (dev->hs_config)
1904                 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1905         else
1906                 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1907
1908         value = usb_gadget_probe_driver(&gadgetfs_driver);
1909         if (value != 0) {
1910                 kfree (dev->buf);
1911                 dev->buf = NULL;
1912         } else {
1913                 /* at this point "good" hardware has for the first time
1914                  * let the USB the host see us.  alternatively, if users
1915                  * unplug/replug that will clear all the error state.
1916                  *
1917                  * note:  everything running before here was guaranteed
1918                  * to choke driver model style diagnostics.  from here
1919                  * on, they can work ... except in cleanup paths that
1920                  * kick in after the ep0 descriptor is closed.
1921                  */
1922                 fd->f_op = &ep0_io_operations;
1923                 value = len;
1924         }
1925         return value;
1926
1927 fail:
1928         spin_unlock_irq (&dev->lock);
1929         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1930         kfree (dev->buf);
1931         dev->buf = NULL;
1932         return value;
1933 }
1934
1935 static int
1936 dev_open (struct inode *inode, struct file *fd)
1937 {
1938         struct dev_data         *dev = inode->i_private;
1939         int                     value = -EBUSY;
1940
1941         spin_lock_irq(&dev->lock);
1942         if (dev->state == STATE_DEV_DISABLED) {
1943                 dev->ev_next = 0;
1944                 dev->state = STATE_DEV_OPENED;
1945                 fd->private_data = dev;
1946                 get_dev (dev);
1947                 value = 0;
1948         }
1949         spin_unlock_irq(&dev->lock);
1950         return value;
1951 }
1952
1953 static const struct file_operations dev_init_operations = {
1954         .llseek =       no_llseek,
1955
1956         .open =         dev_open,
1957         .write =        dev_config,
1958         .fasync =       ep0_fasync,
1959         .unlocked_ioctl = dev_ioctl,
1960         .release =      dev_release,
1961 };
1962
1963 /*----------------------------------------------------------------------*/
1964
1965 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1966  *
1967  * Mounting the filesystem creates a controller file, used first for
1968  * device configuration then later for event monitoring.
1969  */
1970
1971
1972 /* FIXME PAM etc could set this security policy without mount options
1973  * if epfiles inherited ownership and permissons from ep0 ...
1974  */
1975
1976 static unsigned default_uid;
1977 static unsigned default_gid;
1978 static unsigned default_perm = S_IRUSR | S_IWUSR;
1979
1980 module_param (default_uid, uint, 0644);
1981 module_param (default_gid, uint, 0644);
1982 module_param (default_perm, uint, 0644);
1983
1984
1985 static struct inode *
1986 gadgetfs_make_inode (struct super_block *sb,
1987                 void *data, const struct file_operations *fops,
1988                 int mode)
1989 {
1990         struct inode *inode = new_inode (sb);
1991
1992         if (inode) {
1993                 inode->i_ino = get_next_ino();
1994                 inode->i_mode = mode;
1995                 inode->i_uid = make_kuid(&init_user_ns, default_uid);
1996                 inode->i_gid = make_kgid(&init_user_ns, default_gid);
1997                 inode->i_atime = inode->i_mtime = inode->i_ctime
1998                                 = CURRENT_TIME;
1999                 inode->i_private = data;
2000                 inode->i_fop = fops;
2001         }
2002         return inode;
2003 }
2004
2005 /* creates in fs root directory, so non-renamable and non-linkable.
2006  * so inode and dentry are paired, until device reconfig.
2007  */
2008 static struct inode *
2009 gadgetfs_create_file (struct super_block *sb, char const *name,
2010                 void *data, const struct file_operations *fops,
2011                 struct dentry **dentry_p)
2012 {
2013         struct dentry   *dentry;
2014         struct inode    *inode;
2015
2016         dentry = d_alloc_name(sb->s_root, name);
2017         if (!dentry)
2018                 return NULL;
2019
2020         inode = gadgetfs_make_inode (sb, data, fops,
2021                         S_IFREG | (default_perm & S_IRWXUGO));
2022         if (!inode) {
2023                 dput(dentry);
2024                 return NULL;
2025         }
2026         d_add (dentry, inode);
2027         *dentry_p = dentry;
2028         return inode;
2029 }
2030
2031 static const struct super_operations gadget_fs_operations = {
2032         .statfs =       simple_statfs,
2033         .drop_inode =   generic_delete_inode,
2034 };
2035
2036 static int
2037 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2038 {
2039         struct inode    *inode;
2040         struct dev_data *dev;
2041
2042         if (the_device)
2043                 return -ESRCH;
2044
2045         /* fake probe to determine $CHIP */
2046         CHIP = NULL;
2047         usb_gadget_probe_driver(&probe_driver);
2048         if (!CHIP)
2049                 return -ENODEV;
2050
2051         /* superblock */
2052         sb->s_blocksize = PAGE_CACHE_SIZE;
2053         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2054         sb->s_magic = GADGETFS_MAGIC;
2055         sb->s_op = &gadget_fs_operations;
2056         sb->s_time_gran = 1;
2057
2058         /* root inode */
2059         inode = gadgetfs_make_inode (sb,
2060                         NULL, &simple_dir_operations,
2061                         S_IFDIR | S_IRUGO | S_IXUGO);
2062         if (!inode)
2063                 goto Enomem;
2064         inode->i_op = &simple_dir_inode_operations;
2065         if (!(sb->s_root = d_make_root (inode)))
2066                 goto Enomem;
2067
2068         /* the ep0 file is named after the controller we expect;
2069          * user mode code can use it for sanity checks, like we do.
2070          */
2071         dev = dev_new ();
2072         if (!dev)
2073                 goto Enomem;
2074
2075         dev->sb = sb;
2076         if (!gadgetfs_create_file (sb, CHIP,
2077                                 dev, &dev_init_operations,
2078                                 &dev->dentry)) {
2079                 put_dev(dev);
2080                 goto Enomem;
2081         }
2082
2083         /* other endpoint files are available after hardware setup,
2084          * from binding to a controller.
2085          */
2086         the_device = dev;
2087         return 0;
2088
2089 Enomem:
2090         return -ENOMEM;
2091 }
2092
2093 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2094 static struct dentry *
2095 gadgetfs_mount (struct file_system_type *t, int flags,
2096                 const char *path, void *opts)
2097 {
2098         return mount_single (t, flags, opts, gadgetfs_fill_super);
2099 }
2100
2101 static void
2102 gadgetfs_kill_sb (struct super_block *sb)
2103 {
2104         kill_litter_super (sb);
2105         if (the_device) {
2106                 put_dev (the_device);
2107                 the_device = NULL;
2108         }
2109 }
2110
2111 /*----------------------------------------------------------------------*/
2112
2113 static struct file_system_type gadgetfs_type = {
2114         .owner          = THIS_MODULE,
2115         .name           = shortname,
2116         .mount          = gadgetfs_mount,
2117         .kill_sb        = gadgetfs_kill_sb,
2118 };
2119 MODULE_ALIAS_FS("gadgetfs");
2120
2121 /*----------------------------------------------------------------------*/
2122
2123 static int __init init (void)
2124 {
2125         int status;
2126
2127         status = register_filesystem (&gadgetfs_type);
2128         if (status == 0)
2129                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2130                         shortname, driver_desc);
2131         return status;
2132 }
2133 module_init (init);
2134
2135 static void __exit cleanup (void)
2136 {
2137         pr_debug ("unregister %s\n", shortname);
2138         unregister_filesystem (&gadgetfs_type);
2139 }
2140 module_exit (cleanup);
2141