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
  28 #include <linux/device.h>
  29 #include <linux/moduleparam.h>
  30
  31 #include <linux/usb/gadgetfs.h>
  32 #include <linux/usb/gadget.h>
  33
  34
  35 /*
  36  * The gadgetfs API maps each endpoint to a file descriptor so that you
  37  * can use standard synchronous read/write calls for I/O.  There's some
  38  * O_NONBLOCK and O_ASYNC/FASYNC style i/o support.  Example usermode
  39  * drivers show how this works in practice.  You can also use AIO to
  40  * eliminate I/O gaps between requests, to help when streaming data.
  41  *
  42  * Key parts that must be USB-specific are protocols defining how the
  43  * read/write operations relate to the hardware state machines.  There
  44  * are two types of files.  One type is for the device, implementing ep0.
  45  * The other type is for each IN or OUT endpoint.  In both cases, the
  46  * user mode driver must configure the hardware before using it.
  47  *
  48  * - First, dev_config() is called when /dev/gadget/$CHIP is configured
  49  *   (by writing configuration and device descriptors).  Afterwards it
  50  *   may serve as a source of device events, used to handle all control
  51  *   requests other than basic enumeration.
  52  *
  53  * - Then, after a SET_CONFIGURATION control request, ep_config() is
  54  *   called when each /dev/gadget/ep* file is configured (by writing
  55  *   endpoint descriptors).  Afterwards these files are used to write()
  56  *   IN data or to read() OUT data.  To halt the endpoint, a "wrong
  57  *   direction" request is issued (like reading an IN endpoint).
  58  *
  59  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
  60  * not possible on all hardware.  For example, precise fault handling with
  61  * respect to data left in endpoint fifos after aborted operations; or
  62  * selective clearing of endpoint halts, to implement SET_INTERFACE.
  63  */
  64
  65 #define DRIVER_DESC     "USB Gadget filesystem"
  66 #define DRIVER_VERSION  "24 Aug 2004"
  67
  68 static const char driver_desc [] = DRIVER_DESC;
  69 static const char shortname [] = "gadgetfs";
  70
  71 MODULE_DESCRIPTION (DRIVER_DESC);
  72 MODULE_AUTHOR ("David Brownell");
  73 MODULE_LICENSE ("GPL");
  74
  75
  76 /*----------------------------------------------------------------------*/
  77
  78 #define GADGETFS_MAGIC          0xaee71ee7
  79 #define DMA_ADDR_INVALID        (~(dma_addr_t)0)
  80
  81 /* /dev/gadget/$CHIP represents ep0 and the whole device */
  82 enum ep0_state {
  83         /* DISBLED is the initial state.
  84          */
  85         STATE_DEV_DISABLED = 0,
  86
  87         /* Only one open() of /dev/gadget/$CHIP; only one file tracks
  88          * ep0/device i/o modes and binding to the controller.  Driver
  89          * must always write descriptors to initialize the device, then
  90          * the device becomes UNCONNECTED until enumeration.
  91          */
  92         STATE_DEV_OPENED,
  93
  94         /* From then on, ep0 fd is in either of two basic modes:
  95          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
  96          * - SETUP: read/write will transfer control data and succeed;
  97          *   or if "wrong direction", performs protocol stall
  98          */
  99         STATE_DEV_UNCONNECTED,
 100         STATE_DEV_CONNECTED,
 101         STATE_DEV_SETUP,
 102
 103         /* UNBOUND means the driver closed ep0, so the device won't be
 104          * accessible again (DEV_DISABLED) until all fds are closed.
 105          */
 106         STATE_DEV_UNBOUND,
 107 };
 108
 109 /* enough for the whole queue: most events invalidate others */
 110 #define N_EVENT                 5
 111
 112 struct dev_data {
 113         spinlock_t                      lock;
 114         atomic_t                        count;
 115         enum ep0_state                  state;          /* P: lock */
 116         struct usb_gadgetfs_event       event [N_EVENT];
 117         unsigned                        ev_next;
 118         struct fasync_struct            *fasync;
 119         u8                              current_config;
 120
 121         /* drivers reading ep0 MUST handle control requests (SETUP)
 122          * reported that way; else the host will time out.
 123          */
 124         unsigned                        usermode_setup : 1,
 125                                         setup_in : 1,
 126                                         setup_can_stall : 1,
 127                                         setup_out_ready : 1,
 128                                         setup_out_error : 1,
 129                                         setup_abort : 1;
 130         unsigned                        setup_wLength;
 131
 132         /* the rest is basically write-once */
 133         struct usb_config_descriptor    *config, *hs_config;
 134         struct usb_device_descriptor    *dev;
 135         struct usb_request              *req;
 136         struct usb_gadget               *gadget;
 137         struct list_head                epfiles;
 138         void                            *buf;
 139         wait_queue_head_t               wait;
 140         struct super_block              *sb;
 141         struct dentry                   *dentry;
 142
 143         /* except this scratch i/o buffer for ep0 */
 144         u8                              rbuf [256];
 145 };
 146
 147 static inline void get_dev (struct dev_data *data)
 148 {
 149         atomic_inc (&data->count);
 150 }
 151
 152 static void put_dev (struct dev_data *data)
 153 {
 154         if (likely (!atomic_dec_and_test (&data->count)))
 155                 return;
 156         /* needs no more cleanup */
 157         BUG_ON (waitqueue_active (&data->wait));
 158         kfree (data);
 159 }
 160
 161 static struct dev_data *dev_new (void)
 162 {
 163         struct dev_data         *dev;
 164
 165         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 166         if (!dev)
 167                 return NULL;
 168         dev->state = STATE_DEV_DISABLED;
 169         atomic_set (&dev->count, 1);
 170         spin_lock_init (&dev->lock);
 171         INIT_LIST_HEAD (&dev->epfiles);
 172         init_waitqueue_head (&dev->wait);
 173         return dev;
 174 }
 175
 176 /*----------------------------------------------------------------------*/
 177
 178 /* other /dev/gadget/$ENDPOINT files represent endpoints */
 179 enum ep_state {
 180         STATE_EP_DISABLED = 0,
 181         STATE_EP_READY,
 182         STATE_EP_ENABLED,
 183         STATE_EP_UNBOUND,
 184 };
 185
 186 struct ep_data {
 187         struct mutex                    lock;
 188         enum ep_state                   state;
 189         atomic_t                        count;
 190         struct dev_data                 *dev;
 191         /* must hold dev->lock before accessing ep or req */
 192         struct usb_ep                   *ep;
 193         struct usb_request              *req;
 194         ssize_t                         status;
 195         char                            name [16];
 196         struct usb_endpoint_descriptor  desc, hs_desc;
 197         struct list_head                epfiles;
 198         wait_queue_head_t               wait;
 199         struct dentry                   *dentry;
 200         struct inode                    *inode;
 201 };
 202
 203 static inline void get_ep (struct ep_data *data)
 204 {
 205         atomic_inc (&data->count);
 206 }
 207
 208 static void put_ep (struct ep_data *data)
 209 {
 210         if (likely (!atomic_dec_and_test (&data->count)))
 211                 return;
 212         put_dev (data->dev);
 213         /* needs no more cleanup */
 214         BUG_ON (!list_empty (&data->epfiles));
 215         BUG_ON (waitqueue_active (&data->wait));
 216         kfree (data);
 217 }
 218
 219 /*----------------------------------------------------------------------*/
 220
 221 /* most "how to use the hardware" policy choices are in userspace:
 222  * mapping endpoint roles (which the driver needs) to the capabilities
 223  * which the usb controller has.  most of those capabilities are exposed
 224  * implicitly, starting with the driver name and then endpoint names.
 225  */
 226
 227 static const char *CHIP;
 228
 229 /*----------------------------------------------------------------------*/
 230
 231 /* NOTE:  don't use dev_printk calls before binding to the gadget
 232  * at the end of ep0 configuration, or after unbind.
 233  */
 234
 235 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
 236 #define xprintk(d,level,fmt,args...) \
 237         printk(level "%s: " fmt , shortname , ## args)
 238
 239 #ifdef DEBUG
 240 #define DBG(dev,fmt,args...) \
 241         xprintk(dev , KERN_DEBUG , fmt , ## args)
 242 #else
 243 #define DBG(dev,fmt,args...) \
 244         do { } while (0)
 245 #endif /* DEBUG */
 246
 247 #ifdef VERBOSE_DEBUG
 248 #define VDEBUG  DBG
 249 #else
 250 #define VDEBUG(dev,fmt,args...) \
 251         do { } while (0)
 252 #endif /* DEBUG */
 253
 254 #define ERROR(dev,fmt,args...) \
 255         xprintk(dev , KERN_ERR , fmt , ## args)
 256 #define INFO(dev,fmt,args...) \
 257         xprintk(dev , KERN_INFO , fmt , ## args)
 258
 259
 260 /*----------------------------------------------------------------------*/
 261
 262 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 263  *
 264  * After opening, configure non-control endpoints.  Then use normal
 265  * stream read() and write() requests; and maybe ioctl() to get more
 266  * precise FIFO status when recovering from cancellation.
 267  */
 268
 269 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 270 {
 271         struct ep_data  *epdata = ep->driver_data;
 272
 273         if (!req->context)
 274                 return;
 275         if (req->status)
 276                 epdata->status = req->status;
 277         else
 278                 epdata->status = req->actual;
 279         complete ((struct completion *)req->context);
 280 }
 281
 282 /* tasklock endpoint, returning when it's connected.
 283  * still need dev->lock to use epdata->ep.
 284  */
 285 static int
 286 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
 287 {
 288         int     val;
 289
 290         if (f_flags & O_NONBLOCK) {
 291                 if (!mutex_trylock(&epdata->lock))
 292                         goto nonblock;
 293                 if (epdata->state != STATE_EP_ENABLED) {
 294                         mutex_unlock(&epdata->lock);
 295 nonblock:
 296                         val = -EAGAIN;
 297                 } else
 298                         val = 0;
 299                 return val;
 300         }
 301
 302         val = mutex_lock_interruptible(&epdata->lock);
 303         if (val < 0)
 304                 return val;
 305
 306         switch (epdata->state) {
 307         case STATE_EP_ENABLED:
 308                 break;
 309         // case STATE_EP_DISABLED:              /* "can't happen" */
 310         // case STATE_EP_READY:                 /* "can't happen" */
 311         default:                                /* error! */
 312                 pr_debug ("%s: ep %p not available, state %d\n",
 313                                 shortname, epdata, epdata->state);
 314                 // FALLTHROUGH
 315         case STATE_EP_UNBOUND:                  /* clean disconnect */
 316                 val = -ENODEV;
 317                 mutex_unlock(&epdata->lock);
 318         }
 319         return val;
 320 }
 321
 322 static ssize_t
 323 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 324 {
 325         DECLARE_COMPLETION_ONSTACK (done);
 326         int value;
 327
 328         spin_lock_irq (&epdata->dev->lock);
 329         if (likely (epdata->ep != NULL)) {
 330                 struct usb_request      *req = epdata->req;
 331
 332                 req->context = &done;
 333                 req->complete = epio_complete;
 334                 req->buf = buf;
 335                 req->length = len;
 336                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 337         } else
 338                 value = -ENODEV;
 339         spin_unlock_irq (&epdata->dev->lock);
 340
 341         if (likely (value == 0)) {
 342                 value = wait_event_interruptible (done.wait, done.done);
 343                 if (value != 0) {
 344                         spin_lock_irq (&epdata->dev->lock);
 345                         if (likely (epdata->ep != NULL)) {
 346                                 DBG (epdata->dev, "%s i/o interrupted\n",
 347                                                 epdata->name);
 348                                 usb_ep_dequeue (epdata->ep, epdata->req);
 349                                 spin_unlock_irq (&epdata->dev->lock);
 350
 351                                 wait_event (done.wait, done.done);
 352                                 if (epdata->status == -ECONNRESET)
 353                                         epdata->status = -EINTR;
 354                         } else {
 355                                 spin_unlock_irq (&epdata->dev->lock);
 356
 357                                 DBG (epdata->dev, "endpoint gone\n");
 358                                 epdata->status = -ENODEV;
 359                         }
 360                 }
 361                 return epdata->status;
 362         }
 363         return value;
 364 }
 365
 366
 367 /* handle a synchronous OUT bulk/intr/iso transfer */
 368 static ssize_t
 369 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 370 {
 371         struct ep_data          *data = fd->private_data;
 372         void                    *kbuf;
 373         ssize_t                 value;
 374
 375         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 376                 return value;
 377
 378         /* halt any endpoint by doing a "wrong direction" i/o call */
 379         if (usb_endpoint_dir_in(&data->desc)) {
 380                 if (usb_endpoint_xfer_isoc(&data->desc)) {
 381                         mutex_unlock(&data->lock);
 382                         return -EINVAL;
 383                 }
 384                 DBG (data->dev, "%s halt\n", data->name);
 385                 spin_lock_irq (&data->dev->lock);
 386                 if (likely (data->ep != NULL))
 387                         usb_ep_set_halt (data->ep);
 388                 spin_unlock_irq (&data->dev->lock);
 389                 mutex_unlock(&data->lock);
 390                 return -EBADMSG;
 391         }
 392
 393         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
 394
 395         value = -ENOMEM;
 396         kbuf = kmalloc (len, GFP_KERNEL);
 397         if (unlikely (!kbuf))
 398                 goto free1;
 399
 400         value = ep_io (data, kbuf, len);
 401         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
 402                 data->name, len, (int) value);
 403         if (value >= 0 && copy_to_user (buf, kbuf, value))
 404                 value = -EFAULT;
 405
 406 free1:
 407         mutex_unlock(&data->lock);
 408         kfree (kbuf);
 409         return value;
 410 }
 411
 412 /* handle a synchronous IN bulk/intr/iso transfer */
 413 static ssize_t
 414 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 415 {
 416         struct ep_data          *data = fd->private_data;
 417         void                    *kbuf;
 418         ssize_t                 value;
 419
 420         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 421                 return value;
 422
 423         /* halt any endpoint by doing a "wrong direction" i/o call */
 424         if (!usb_endpoint_dir_in(&data->desc)) {
 425                 if (usb_endpoint_xfer_isoc(&data->desc)) {
 426                         mutex_unlock(&data->lock);
 427                         return -EINVAL;
 428                 }
 429                 DBG (data->dev, "%s halt\n", data->name);
 430                 spin_lock_irq (&data->dev->lock);
 431                 if (likely (data->ep != NULL))
 432                         usb_ep_set_halt (data->ep);
 433                 spin_unlock_irq (&data->dev->lock);
 434                 mutex_unlock(&data->lock);
 435                 return -EBADMSG;
 436         }
 437
 438         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
 439
 440         value = -ENOMEM;
 441         kbuf = kmalloc (len, GFP_KERNEL);
 442         if (!kbuf)
 443                 goto free1;
 444         if (copy_from_user (kbuf, buf, len)) {
 445                 value = -EFAULT;
 446                 goto free1;
 447         }
 448
 449         value = ep_io (data, kbuf, len);
 450         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
 451                 data->name, len, (int) value);
 452 free1:
 453         mutex_unlock(&data->lock);
 454         kfree (kbuf);
 455         return value;
 456 }
 457
 458 static int
 459 ep_release (struct inode *inode, struct file *fd)
 460 {
 461         struct ep_data          *data = fd->private_data;
 462         int value;
 463
 464         value = mutex_lock_interruptible(&data->lock);
 465         if (value < 0)
 466                 return value;
 467
 468         /* clean up if this can be reopened */
 469         if (data->state != STATE_EP_UNBOUND) {
 470                 data->state = STATE_EP_DISABLED;
 471                 data->desc.bDescriptorType = 0;
 472                 data->hs_desc.bDescriptorType = 0;
 473                 usb_ep_disable(data->ep);
 474         }
 475         mutex_unlock(&data->lock);
 476         put_ep (data);
 477         return 0;
 478 }
 479
 480 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
 481 {
 482         struct ep_data          *data = fd->private_data;
 483         int                     status;
 484
 485         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 486                 return status;
 487
 488         spin_lock_irq (&data->dev->lock);
 489         if (likely (data->ep != NULL)) {
 490                 switch (code) {
 491                 case GADGETFS_FIFO_STATUS:
 492                         status = usb_ep_fifo_status (data->ep);
 493                         break;
 494                 case GADGETFS_FIFO_FLUSH:
 495                         usb_ep_fifo_flush (data->ep);
 496                         break;
 497                 case GADGETFS_CLEAR_HALT:
 498                         status = usb_ep_clear_halt (data->ep);
 499                         break;
 500                 default:
 501                         status = -ENOTTY;
 502                 }
 503         } else
 504                 status = -ENODEV;
 505         spin_unlock_irq (&data->dev->lock);
 506         mutex_unlock(&data->lock);
 507         return status;
 508 }
 509
 510 /*----------------------------------------------------------------------*/
 511
 512 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 513
 514 struct kiocb_priv {
 515         struct usb_request      *req;
 516         struct ep_data          *epdata;
 517         void                    *buf;
 518         const struct iovec      *iv;
 519         unsigned long           nr_segs;
 520         unsigned                actual;
 521 };
 522
 523 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
 524 {
 525         struct kiocb_priv       *priv = iocb->private;
 526         struct ep_data          *epdata;
 527         int                     value;
 528
 529         local_irq_disable();
 530         epdata = priv->epdata;
 531         // spin_lock(&epdata->dev->lock);
 532         kiocbSetCancelled(iocb);
 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         aio_put_req(iocb);
 541         return value;
 542 }
 543
 544 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
 545 {
 546         struct kiocb_priv       *priv = iocb->private;
 547         ssize_t                 len, total;
 548         void                    *to_copy;
 549         int                     i;
 550
 551         /* we "retry" to get the right mm context for this: */
 552
 553         /* copy stuff into user buffers */
 554         total = priv->actual;
 555         len = 0;
 556         to_copy = priv->buf;
 557         for (i=0; i < priv->nr_segs; i++) {
 558                 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
 559
 560                 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
 561                         if (len == 0)
 562                                 len = -EFAULT;
 563                         break;
 564                 }
 565
 566                 total -= this;
 567                 len += this;
 568                 to_copy += this;
 569                 if (total == 0)
 570                         break;
 571         }
 572         kfree(priv->buf);
 573         kfree(priv);
 574         return len;
 575 }
 576
 577 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 578 {
 579         struct kiocb            *iocb = req->context;
 580         struct kiocb_priv       *priv = iocb->private;
 581         struct ep_data          *epdata = priv->epdata;
 582
 583         /* lock against disconnect (and ideally, cancel) */
 584         spin_lock(&epdata->dev->lock);
 585         priv->req = NULL;
 586         priv->epdata = NULL;
 587
 588         /* if this was a write or a read returning no data then we
 589          * don't need to copy anything to userspace, so we can
 590          * complete the aio request immediately.
 591          */
 592         if (priv->iv == NULL || unlikely(req->actual == 0)) {
 593                 kfree(req->buf);
 594                 kfree(priv);
 595                 iocb->private = NULL;
 596                 /* aio_complete() reports bytes-transferred _and_ faults */
 597                 aio_complete(iocb, req->actual ? req->actual : req->status,
 598                                 req->status);
 599         } else {
 600                 /* retry() won't report both; so we hide some faults */
 601                 if (unlikely(0 != req->status))
 602                         DBG(epdata->dev, "%s fault %d len %d\n",
 603                                 ep->name, req->status, req->actual);
 604
 605                 priv->buf = req->buf;
 606                 priv->actual = req->actual;
 607                 kick_iocb(iocb);
 608         }
 609         spin_unlock(&epdata->dev->lock);
 610
 611         usb_ep_free_request(ep, req);
 612         put_ep(epdata);
 613 }
 614
 615 static ssize_t
 616 ep_aio_rwtail(
 617         struct kiocb    *iocb,
 618         char            *buf,
 619         size_t          len,
 620         struct ep_data  *epdata,
 621         const struct iovec *iv,
 622         unsigned long   nr_segs
 623 )
 624 {
 625         struct kiocb_priv       *priv;
 626         struct usb_request      *req;
 627         ssize_t                 value;
 628
 629         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 630         if (!priv) {
 631                 value = -ENOMEM;
 632 fail:
 633                 kfree(buf);
 634                 return value;
 635         }
 636         iocb->private = priv;
 637         priv->iv = iv;
 638         priv->nr_segs = nr_segs;
 639
 640         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 641         if (unlikely(value < 0)) {
 642                 kfree(priv);
 643                 goto fail;
 644         }
 645
 646         iocb->ki_cancel = ep_aio_cancel;
 647         get_ep(epdata);
 648         priv->epdata = epdata;
 649         priv->actual = 0;
 650
 651         /* each kiocb is coupled to one usb_request, but we can't
 652          * allocate or submit those if the host disconnected.
 653          */
 654         spin_lock_irq(&epdata->dev->lock);
 655         if (likely(epdata->ep)) {
 656                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 657                 if (likely(req)) {
 658                         priv->req = req;
 659                         req->buf = buf;
 660                         req->length = len;
 661                         req->complete = ep_aio_complete;
 662                         req->context = iocb;
 663                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 664                         if (unlikely(0 != value))
 665                                 usb_ep_free_request(epdata->ep, req);
 666                 } else
 667                         value = -EAGAIN;
 668         } else
 669                 value = -ENODEV;
 670         spin_unlock_irq(&epdata->dev->lock);
 671
 672         mutex_unlock(&epdata->lock);
 673
 674         if (unlikely(value)) {
 675                 kfree(priv);
 676                 put_ep(epdata);
 677         } else
 678                 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
 679         return value;
 680 }
 681
 682 static ssize_t
 683 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
 684                 unsigned long nr_segs, loff_t o)
 685 {
 686         struct ep_data          *epdata = iocb->ki_filp->private_data;
 687         char                    *buf;
 688
 689         if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
 690                 return -EINVAL;
 691
 692         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 693         if (unlikely(!buf))
 694                 return -ENOMEM;
 695
 696         iocb->ki_retry = ep_aio_read_retry;
 697         return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
 698 }
 699
 700 static ssize_t
 701 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
 702                 unsigned long nr_segs, loff_t o)
 703 {
 704         struct ep_data          *epdata = iocb->ki_filp->private_data;
 705         char                    *buf;
 706         size_t                  len = 0;
 707         int                     i = 0;
 708
 709         if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
 710                 return -EINVAL;
 711
 712         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 713         if (unlikely(!buf))
 714                 return -ENOMEM;
 715
 716         for (i=0; i < nr_segs; i++) {
 717                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
 718                                 iov[i].iov_len) != 0)) {
 719                         kfree(buf);
 720                         return -EFAULT;
 721                 }
 722                 len += iov[i].iov_len;
 723         }
 724         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
 725 }
 726
 727 /*----------------------------------------------------------------------*/
 728
 729 /* used after endpoint configuration */
 730 static const struct file_operations ep_io_operations = {
 731         .owner =        THIS_MODULE,
 732         .llseek =       no_llseek,
 733
 734         .read =         ep_read,
 735         .write =        ep_write,
 736         .unlocked_ioctl = ep_ioctl,
 737         .release =      ep_release,
 738
 739         .aio_read =     ep_aio_read,
 740         .aio_write =    ep_aio_write,
 741 };
 742
 743 /* ENDPOINT INITIALIZATION
 744  *
 745  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 746  *     status = write (fd, descriptors, sizeof descriptors)
 747  *
 748  * That write establishes the endpoint configuration, configuring
 749  * the controller to process bulk, interrupt, or isochronous transfers
 750  * at the right maxpacket size, and so on.
 751  *
 752  * The descriptors are message type 1, identified by a host order u32
 753  * at the beginning of what's written.  Descriptor order is: full/low
 754  * speed descriptor, then optional high speed descriptor.
 755  */
 756 static ssize_t
 757 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 758 {
 759         struct ep_data          *data = fd->private_data;
 760         struct usb_ep           *ep;
 761         u32                     tag;
 762         int                     value, length = len;
 763
 764         value = mutex_lock_interruptible(&data->lock);
 765         if (value < 0)
 766                 return value;
 767
 768         if (data->state != STATE_EP_READY) {
 769                 value = -EL2HLT;
 770                 goto fail;
 771         }
 772
 773         value = len;
 774         if (len < USB_DT_ENDPOINT_SIZE + 4)
 775                 goto fail0;
 776
 777         /* we might need to change message format someday */
 778         if (copy_from_user (&tag, buf, 4)) {
 779                 goto fail1;
 780         }
 781         if (tag != 1) {
 782                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 783                 goto fail0;
 784         }
 785         buf += 4;
 786         len -= 4;
 787
 788         /* NOTE:  audio endpoint extensions not accepted here;
 789          * just don't include the extra bytes.
 790          */
 791
 792         /* full/low speed descriptor, then high speed */
 793         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 794                 goto fail1;
 795         }
 796         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 797                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 798                 goto fail0;
 799         if (len != USB_DT_ENDPOINT_SIZE) {
 800                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 801                         goto fail0;
 802                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 803                                         USB_DT_ENDPOINT_SIZE)) {
 804                         goto fail1;
 805                 }
 806                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 807                                 || data->hs_desc.bDescriptorType
 808                                         != USB_DT_ENDPOINT) {
 809                         DBG(data->dev, "config %s, bad hs length or type\n",
 810                                         data->name);
 811                         goto fail0;
 812                 }
 813         }
 814
 815         spin_lock_irq (&data->dev->lock);
 816         if (data->dev->state == STATE_DEV_UNBOUND) {
 817                 value = -ENOENT;
 818                 goto gone;
 819         } else if ((ep = data->ep) == NULL) {
 820                 value = -ENODEV;
 821                 goto gone;
 822         }
 823         switch (data->dev->gadget->speed) {
 824         case USB_SPEED_LOW:
 825         case USB_SPEED_FULL:
 826                 ep->desc = &data->desc;
 827                 value = usb_ep_enable(ep);
 828                 if (value == 0)
 829                         data->state = STATE_EP_ENABLED;
 830                 break;
 831 #ifdef  CONFIG_USB_GADGET_DUALSPEED
 832         case USB_SPEED_HIGH:
 833                 /* fails if caller didn't provide that descriptor... */
 834                 ep->desc = &data->hs_desc;
 835                 value = usb_ep_enable(ep);
 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         mutex_unlock(&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 (mutex_lock_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         mutex_unlock(&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                                 else
1047                                         retval = len;
1048                                 clean_req (dev->gadget->ep0, dev->req);
1049                                 /* NOTE userspace can't yet choose to stall */
1050                         }
1051                 }
1052                 goto done;
1053         }
1054
1055         /* else normal: return event data */
1056         if (len < sizeof dev->event [0]) {
1057                 retval = -EINVAL;
1058                 goto done;
1059         }
1060         len -= len % sizeof (struct usb_gadgetfs_event);
1061         dev->usermode_setup = 1;
1062
1063 scan:
1064         /* return queued events right away */
1065         if (dev->ev_next != 0) {
1066                 unsigned                i, n;
1067
1068                 n = len / sizeof (struct usb_gadgetfs_event);
1069                 if (dev->ev_next < n)
1070                         n = dev->ev_next;
1071
1072                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1073                 for (i = 0; i < n; i++) {
1074                         if (dev->event [i].type == GADGETFS_SETUP) {
1075                                 dev->state = STATE_DEV_SETUP;
1076                                 n = i + 1;
1077                                 break;
1078                         }
1079                 }
1080                 spin_unlock_irq (&dev->lock);
1081                 len = n * sizeof (struct usb_gadgetfs_event);
1082                 if (copy_to_user (buf, &dev->event, len))
1083                         retval = -EFAULT;
1084                 else
1085                         retval = len;
1086                 if (len > 0) {
1087                         /* NOTE this doesn't guard against broken drivers;
1088                          * concurrent ep0 readers may lose events.
1089                          */
1090                         spin_lock_irq (&dev->lock);
1091                         if (dev->ev_next > n) {
1092                                 memmove(&dev->event[0], &dev->event[n],
1093                                         sizeof (struct usb_gadgetfs_event)
1094                                                 * (dev->ev_next - n));
1095                         }
1096                         dev->ev_next -= n;
1097                         spin_unlock_irq (&dev->lock);
1098                 }
1099                 return retval;
1100         }
1101         if (fd->f_flags & O_NONBLOCK) {
1102                 retval = -EAGAIN;
1103                 goto done;
1104         }
1105
1106         switch (state) {
1107         default:
1108                 DBG (dev, "fail %s, state %d\n", __func__, state);
1109                 retval = -ESRCH;
1110                 break;
1111         case STATE_DEV_UNCONNECTED:
1112         case STATE_DEV_CONNECTED:
1113                 spin_unlock_irq (&dev->lock);
1114                 DBG (dev, "%s wait\n", __func__);
1115
1116                 /* wait for events */
1117                 retval = wait_event_interruptible (dev->wait,
1118                                 dev->ev_next != 0);
1119                 if (retval < 0)
1120                         return retval;
1121                 spin_lock_irq (&dev->lock);
1122                 goto scan;
1123         }
1124
1125 done:
1126         spin_unlock_irq (&dev->lock);
1127         return retval;
1128 }
1129
1130 static struct usb_gadgetfs_event *
1131 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1132 {
1133         struct usb_gadgetfs_event       *event;
1134         unsigned                        i;
1135
1136         switch (type) {
1137         /* these events purge the queue */
1138         case GADGETFS_DISCONNECT:
1139                 if (dev->state == STATE_DEV_SETUP)
1140                         dev->setup_abort = 1;
1141                 // FALL THROUGH
1142         case GADGETFS_CONNECT:
1143                 dev->ev_next = 0;
1144                 break;
1145         case GADGETFS_SETUP:            /* previous request timed out */
1146         case GADGETFS_SUSPEND:          /* same effect */
1147                 /* these events can't be repeated */
1148                 for (i = 0; i != dev->ev_next; i++) {
1149                         if (dev->event [i].type != type)
1150                                 continue;
1151                         DBG(dev, "discard old event[%d] %d\n", i, type);
1152                         dev->ev_next--;
1153                         if (i == dev->ev_next)
1154                                 break;
1155                         /* indices start at zero, for simplicity */
1156                         memmove (&dev->event [i], &dev->event [i + 1],
1157                                 sizeof (struct usb_gadgetfs_event)
1158                                         * (dev->ev_next - i));
1159                 }
1160                 break;
1161         default:
1162                 BUG ();
1163         }
1164         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1165         event = &dev->event [dev->ev_next++];
1166         BUG_ON (dev->ev_next > N_EVENT);
1167         memset (event, 0, sizeof *event);
1168         event->type = type;
1169         return event;
1170 }
1171
1172 static ssize_t
1173 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1174 {
1175         struct dev_data         *dev = fd->private_data;
1176         ssize_t                 retval = -ESRCH;
1177
1178         spin_lock_irq (&dev->lock);
1179
1180         /* report fd mode change before acting on it */
1181         if (dev->setup_abort) {
1182                 dev->setup_abort = 0;
1183                 retval = -EIDRM;
1184
1185         /* data and/or status stage for control request */
1186         } else if (dev->state == STATE_DEV_SETUP) {
1187
1188                 /* IN DATA+STATUS caller makes len <= wLength */
1189                 if (dev->setup_in) {
1190                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1191                         if (retval == 0) {
1192                                 dev->state = STATE_DEV_CONNECTED;
1193                                 spin_unlock_irq (&dev->lock);
1194                                 if (copy_from_user (dev->req->buf, buf, len))
1195                                         retval = -EFAULT;
1196                                 else {
1197                                         if (len < dev->setup_wLength)
1198                                                 dev->req->zero = 1;
1199                                         retval = usb_ep_queue (
1200                                                 dev->gadget->ep0, dev->req,
1201                                                 GFP_KERNEL);
1202                                 }
1203                                 if (retval < 0) {
1204                                         spin_lock_irq (&dev->lock);
1205                                         clean_req (dev->gadget->ep0, dev->req);
1206                                         spin_unlock_irq (&dev->lock);
1207                                 } else
1208                                         retval = len;
1209
1210                                 return retval;
1211                         }
1212
1213                 /* can stall some OUT transfers */
1214                 } else if (dev->setup_can_stall) {
1215                         VDEBUG(dev, "ep0out stall\n");
1216                         (void) usb_ep_set_halt (dev->gadget->ep0);
1217                         retval = -EL2HLT;
1218                         dev->state = STATE_DEV_CONNECTED;
1219                 } else {
1220                         DBG(dev, "bogus ep0out stall!\n");
1221                 }
1222         } else
1223                 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1224
1225         spin_unlock_irq (&dev->lock);
1226         return retval;
1227 }
1228
1229 static int
1230 ep0_fasync (int f, struct file *fd, int on)
1231 {
1232         struct dev_data         *dev = fd->private_data;
1233         // caller must F_SETOWN before signal delivery happens
1234         VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1235         return fasync_helper (f, fd, on, &dev->fasync);
1236 }
1237
1238 static struct usb_gadget_driver gadgetfs_driver;
1239
1240 static int
1241 dev_release (struct inode *inode, struct file *fd)
1242 {
1243         struct dev_data         *dev = fd->private_data;
1244
1245         /* closing ep0 === shutdown all */
1246
1247         usb_gadget_unregister_driver (&gadgetfs_driver);
1248
1249         /* at this point "good" hardware has disconnected the
1250          * device from USB; the host won't see it any more.
1251          * alternatively, all host requests will time out.
1252          */
1253
1254         kfree (dev->buf);
1255         dev->buf = NULL;
1256         put_dev (dev);
1257
1258         /* other endpoints were all decoupled from this device */
1259         spin_lock_irq(&dev->lock);
1260         dev->state = STATE_DEV_DISABLED;
1261         spin_unlock_irq(&dev->lock);
1262         return 0;
1263 }
1264
1265 static unsigned int
1266 ep0_poll (struct file *fd, poll_table *wait)
1267 {
1268        struct dev_data         *dev = fd->private_data;
1269        int                     mask = 0;
1270
1271        poll_wait(fd, &dev->wait, wait);
1272
1273        spin_lock_irq (&dev->lock);
1274
1275        /* report fd mode change before acting on it */
1276        if (dev->setup_abort) {
1277                dev->setup_abort = 0;
1278                mask = POLLHUP;
1279                goto out;
1280        }
1281
1282        if (dev->state == STATE_DEV_SETUP) {
1283                if (dev->setup_in || dev->setup_can_stall)
1284                        mask = POLLOUT;
1285        } else {
1286                if (dev->ev_next != 0)
1287                        mask = POLLIN;
1288        }
1289 out:
1290        spin_unlock_irq(&dev->lock);
1291        return mask;
1292 }
1293
1294 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1295 {
1296         struct dev_data         *dev = fd->private_data;
1297         struct usb_gadget       *gadget = dev->gadget;
1298         long ret = -ENOTTY;
1299
1300         if (gadget->ops->ioctl)
1301                 ret = gadget->ops->ioctl (gadget, code, value);
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 = dev->gadget->ep0->maxpacket;
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
1401                 INFO (dev, "connected\n");
1402                 event = next_event (dev, GADGETFS_CONNECT);
1403                 event->u.speed = gadget->speed;
1404                 ep0_readable (dev);
1405
1406         /* host may have given up waiting for response.  we can miss control
1407          * requests handled lower down (device/endpoint status and features);
1408          * then ep0_{read,write} will report the wrong status. controller
1409          * driver will have aborted pending i/o.
1410          */
1411         } else if (dev->state == STATE_DEV_SETUP)
1412                 dev->setup_abort = 1;
1413
1414         req->buf = dev->rbuf;
1415         req->dma = DMA_ADDR_INVALID;
1416         req->context = NULL;
1417         value = -EOPNOTSUPP;
1418         switch (ctrl->bRequest) {
1419
1420         case USB_REQ_GET_DESCRIPTOR:
1421                 if (ctrl->bRequestType != USB_DIR_IN)
1422                         goto unrecognized;
1423                 switch (w_value >> 8) {
1424
1425                 case USB_DT_DEVICE:
1426                         value = min (w_length, (u16) sizeof *dev->dev);
1427                         dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
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         DBG (dev, "%s %d\n", __func__, dev->state);
1575
1576         /* dev->state must prevent interference */
1577 restart:
1578         spin_lock_irq (&dev->lock);
1579         while (!list_empty(&dev->epfiles)) {
1580                 struct ep_data  *ep;
1581                 struct inode    *parent;
1582                 struct dentry   *dentry;
1583
1584                 /* break link to FS */
1585                 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1586                 list_del_init (&ep->epfiles);
1587                 dentry = ep->dentry;
1588                 ep->dentry = NULL;
1589                 parent = dentry->d_parent->d_inode;
1590
1591                 /* break link to controller */
1592                 if (ep->state == STATE_EP_ENABLED)
1593                         (void) usb_ep_disable (ep->ep);
1594                 ep->state = STATE_EP_UNBOUND;
1595                 usb_ep_free_request (ep->ep, ep->req);
1596                 ep->ep = NULL;
1597                 wake_up (&ep->wait);
1598                 put_ep (ep);
1599
1600                 spin_unlock_irq (&dev->lock);
1601
1602                 /* break link to dcache */
1603                 mutex_lock (&parent->i_mutex);
1604                 d_delete (dentry);
1605                 dput (dentry);
1606                 mutex_unlock (&parent->i_mutex);
1607
1608                 spin_lock_irq (&dev->lock);
1609         }
1610         spin_unlock_irq (&dev->lock);
1611 }
1612
1613
1614 static struct inode *
1615 gadgetfs_create_file (struct super_block *sb, char const *name,
1616                 void *data, const struct file_operations *fops,
1617                 struct dentry **dentry_p);
1618
1619 static int activate_ep_files (struct dev_data *dev)
1620 {
1621         struct usb_ep   *ep;
1622         struct ep_data  *data;
1623
1624         gadget_for_each_ep (ep, dev->gadget) {
1625
1626                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1627                 if (!data)
1628                         goto enomem0;
1629                 data->state = STATE_EP_DISABLED;
1630                 mutex_init(&data->lock);
1631                 init_waitqueue_head (&data->wait);
1632
1633                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1634                 atomic_set (&data->count, 1);
1635                 data->dev = dev;
1636                 get_dev (dev);
1637
1638                 data->ep = ep;
1639                 ep->driver_data = data;
1640
1641                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1642                 if (!data->req)
1643                         goto enomem1;
1644
1645                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1646                                 data, &ep_config_operations,
1647                                 &data->dentry);
1648                 if (!data->inode)
1649                         goto enomem2;
1650                 list_add_tail (&data->epfiles, &dev->epfiles);
1651         }
1652         return 0;
1653
1654 enomem2:
1655         usb_ep_free_request (ep, data->req);
1656 enomem1:
1657         put_dev (dev);
1658         kfree (data);
1659 enomem0:
1660         DBG (dev, "%s enomem\n", __func__);
1661         destroy_ep_files (dev);
1662         return -ENOMEM;
1663 }
1664
1665 static void
1666 gadgetfs_unbind (struct usb_gadget *gadget)
1667 {
1668         struct dev_data         *dev = get_gadget_data (gadget);
1669
1670         DBG (dev, "%s\n", __func__);
1671
1672         spin_lock_irq (&dev->lock);
1673         dev->state = STATE_DEV_UNBOUND;
1674         spin_unlock_irq (&dev->lock);
1675
1676         destroy_ep_files (dev);
1677         gadget->ep0->driver_data = NULL;
1678         set_gadget_data (gadget, NULL);
1679
1680         /* we've already been disconnected ... no i/o is active */
1681         if (dev->req)
1682                 usb_ep_free_request (gadget->ep0, dev->req);
1683         DBG (dev, "%s done\n", __func__);
1684         put_dev (dev);
1685 }
1686
1687 static struct dev_data          *the_device;
1688
1689 static int
1690 gadgetfs_bind (struct usb_gadget *gadget)
1691 {
1692         struct dev_data         *dev = the_device;
1693
1694         if (!dev)
1695                 return -ESRCH;
1696         if (0 != strcmp (CHIP, gadget->name)) {
1697                 pr_err("%s expected %s controller not %s\n",
1698                         shortname, CHIP, gadget->name);
1699                 return -ENODEV;
1700         }
1701
1702         set_gadget_data (gadget, dev);
1703         dev->gadget = gadget;
1704         gadget->ep0->driver_data = dev;
1705
1706         /* preallocate control response and buffer */
1707         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1708         if (!dev->req)
1709                 goto enomem;
1710         dev->req->context = NULL;
1711         dev->req->complete = epio_complete;
1712
1713         if (activate_ep_files (dev) < 0)
1714                 goto enomem;
1715
1716         INFO (dev, "bound to %s driver\n", gadget->name);
1717         spin_lock_irq(&dev->lock);
1718         dev->state = STATE_DEV_UNCONNECTED;
1719         spin_unlock_irq(&dev->lock);
1720         get_dev (dev);
1721         return 0;
1722
1723 enomem:
1724         gadgetfs_unbind (gadget);
1725         return -ENOMEM;
1726 }
1727
1728 static void
1729 gadgetfs_disconnect (struct usb_gadget *gadget)
1730 {
1731         struct dev_data         *dev = get_gadget_data (gadget);
1732         unsigned long           flags;
1733
1734         spin_lock_irqsave (&dev->lock, flags);
1735         if (dev->state == STATE_DEV_UNCONNECTED)
1736                 goto exit;
1737         dev->state = STATE_DEV_UNCONNECTED;
1738
1739         INFO (dev, "disconnected\n");
1740         next_event (dev, GADGETFS_DISCONNECT);
1741         ep0_readable (dev);
1742 exit:
1743         spin_unlock_irqrestore (&dev->lock, flags);
1744 }
1745
1746 static void
1747 gadgetfs_suspend (struct usb_gadget *gadget)
1748 {
1749         struct dev_data         *dev = get_gadget_data (gadget);
1750
1751         INFO (dev, "suspended from state %d\n", dev->state);
1752         spin_lock (&dev->lock);
1753         switch (dev->state) {
1754         case STATE_DEV_SETUP:           // VERY odd... host died??
1755         case STATE_DEV_CONNECTED:
1756         case STATE_DEV_UNCONNECTED:
1757                 next_event (dev, GADGETFS_SUSPEND);
1758                 ep0_readable (dev);
1759                 /* FALLTHROUGH */
1760         default:
1761                 break;
1762         }
1763         spin_unlock (&dev->lock);
1764 }
1765
1766 static struct usb_gadget_driver gadgetfs_driver = {
1767 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1768         .max_speed      = USB_SPEED_HIGH,
1769 #else
1770         .max_speed      = USB_SPEED_FULL,
1771 #endif
1772         .function       = (char *) driver_desc,
1773         .unbind         = gadgetfs_unbind,
1774         .setup          = gadgetfs_setup,
1775         .disconnect     = gadgetfs_disconnect,
1776         .suspend        = gadgetfs_suspend,
1777
1778         .driver = {
1779                 .name           = (char *) shortname,
1780         },
1781 };
1782
1783 /*----------------------------------------------------------------------*/
1784
1785 static void gadgetfs_nop(struct usb_gadget *arg) { }
1786
1787 static int gadgetfs_probe (struct usb_gadget *gadget)
1788 {
1789         CHIP = gadget->name;
1790         return -EISNAM;
1791 }
1792
1793 static struct usb_gadget_driver probe_driver = {
1794         .max_speed      = USB_SPEED_HIGH,
1795         .unbind         = gadgetfs_nop,
1796         .setup          = (void *)gadgetfs_nop,
1797         .disconnect     = gadgetfs_nop,
1798         .driver = {
1799                 .name           = "nop",
1800         },
1801 };
1802
1803
1804 /* DEVICE INITIALIZATION
1805  *
1806  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1807  *     status = write (fd, descriptors, sizeof descriptors)
1808  *
1809  * That write establishes the device configuration, so the kernel can
1810  * bind to the controller ... guaranteeing it can handle enumeration
1811  * at all necessary speeds.  Descriptor order is:
1812  *
1813  * . message tag (u32, host order) ... for now, must be zero; it
1814  *      would change to support features like multi-config devices
1815  * . full/low speed config ... all wTotalLength bytes (with interface,
1816  *      class, altsetting, endpoint, and other descriptors)
1817  * . high speed config ... all descriptors, for high speed operation;
1818  *      this one's optional except for high-speed hardware
1819  * . device descriptor
1820  *
1821  * Endpoints are not yet enabled. Drivers must wait until device
1822  * configuration and interface altsetting changes create
1823  * the need to configure (or unconfigure) them.
1824  *
1825  * After initialization, the device stays active for as long as that
1826  * $CHIP file is open.  Events must then be read from that descriptor,
1827  * such as configuration notifications.
1828  */
1829
1830 static int is_valid_config (struct usb_config_descriptor *config)
1831 {
1832         return config->bDescriptorType == USB_DT_CONFIG
1833                 && config->bLength == USB_DT_CONFIG_SIZE
1834                 && config->bConfigurationValue != 0
1835                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1836                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1837         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1838         /* FIXME check lengths: walk to end */
1839 }
1840
1841 static ssize_t
1842 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1843 {
1844         struct dev_data         *dev = fd->private_data;
1845         ssize_t                 value = len, length = len;
1846         unsigned                total;
1847         u32                     tag;
1848         char                    *kbuf;
1849
1850         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1851                 return -EINVAL;
1852
1853         /* we might need to change message format someday */
1854         if (copy_from_user (&tag, buf, 4))
1855                 return -EFAULT;
1856         if (tag != 0)
1857                 return -EINVAL;
1858         buf += 4;
1859         length -= 4;
1860
1861         kbuf = memdup_user(buf, length);
1862         if (IS_ERR(kbuf))
1863                 return PTR_ERR(kbuf);
1864
1865         spin_lock_irq (&dev->lock);
1866         value = -EINVAL;
1867         if (dev->buf)
1868                 goto fail;
1869         dev->buf = kbuf;
1870
1871         /* full or low speed config */
1872         dev->config = (void *) kbuf;
1873         total = le16_to_cpu(dev->config->wTotalLength);
1874         if (!is_valid_config (dev->config) || total >= length)
1875                 goto fail;
1876         kbuf += total;
1877         length -= total;
1878
1879         /* optional high speed config */
1880         if (kbuf [1] == USB_DT_CONFIG) {
1881                 dev->hs_config = (void *) kbuf;
1882                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1883                 if (!is_valid_config (dev->hs_config) || total >= length)
1884                         goto fail;
1885                 kbuf += total;
1886                 length -= total;
1887         }
1888
1889         /* could support multiple configs, using another encoding! */
1890
1891         /* device descriptor (tweaked for paranoia) */
1892         if (length != USB_DT_DEVICE_SIZE)
1893                 goto fail;
1894         dev->dev = (void *)kbuf;
1895         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1896                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1897                         || dev->dev->bNumConfigurations != 1)
1898                 goto fail;
1899         dev->dev->bNumConfigurations = 1;
1900         dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1901
1902         /* triggers gadgetfs_bind(); then we can enumerate. */
1903         spin_unlock_irq (&dev->lock);
1904         value = usb_gadget_probe_driver(&gadgetfs_driver, gadgetfs_bind);
1905         if (value != 0) {
1906                 kfree (dev->buf);
1907                 dev->buf = NULL;
1908         } else {
1909                 /* at this point "good" hardware has for the first time
1910                  * let the USB the host see us.  alternatively, if users
1911                  * unplug/replug that will clear all the error state.
1912                  *
1913                  * note:  everything running before here was guaranteed
1914                  * to choke driver model style diagnostics.  from here
1915                  * on, they can work ... except in cleanup paths that
1916                  * kick in after the ep0 descriptor is closed.
1917                  */
1918                 fd->f_op = &ep0_io_operations;
1919                 value = len;
1920         }
1921         return value;
1922
1923 fail:
1924         spin_unlock_irq (&dev->lock);
1925         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1926         kfree (dev->buf);
1927         dev->buf = NULL;
1928         return value;
1929 }
1930
1931 static int
1932 dev_open (struct inode *inode, struct file *fd)
1933 {
1934         struct dev_data         *dev = inode->i_private;
1935         int                     value = -EBUSY;
1936
1937         spin_lock_irq(&dev->lock);
1938         if (dev->state == STATE_DEV_DISABLED) {
1939                 dev->ev_next = 0;
1940                 dev->state = STATE_DEV_OPENED;
1941                 fd->private_data = dev;
1942                 get_dev (dev);
1943                 value = 0;
1944         }
1945         spin_unlock_irq(&dev->lock);
1946         return value;
1947 }
1948
1949 static const struct file_operations dev_init_operations = {
1950         .owner =        THIS_MODULE,
1951         .llseek =       no_llseek,
1952
1953         .open =         dev_open,
1954         .write =        dev_config,
1955         .fasync =       ep0_fasync,
1956         .unlocked_ioctl = dev_ioctl,
1957         .release =      dev_release,
1958 };
1959
1960 /*----------------------------------------------------------------------*/
1961
1962 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1963  *
1964  * Mounting the filesystem creates a controller file, used first for
1965  * device configuration then later for event monitoring.
1966  */
1967
1968
1969 /* FIXME PAM etc could set this security policy without mount options
1970  * if epfiles inherited ownership and permissons from ep0 ...
1971  */
1972
1973 static unsigned default_uid;
1974 static unsigned default_gid;
1975 static unsigned default_perm = S_IRUSR | S_IWUSR;
1976
1977 module_param (default_uid, uint, 0644);
1978 module_param (default_gid, uint, 0644);
1979 module_param (default_perm, uint, 0644);
1980
1981
1982 static struct inode *
1983 gadgetfs_make_inode (struct super_block *sb,
1984                 void *data, const struct file_operations *fops,
1985                 int mode)
1986 {
1987         struct inode *inode = new_inode (sb);
1988
1989         if (inode) {
1990                 inode->i_ino = get_next_ino();
1991                 inode->i_mode = mode;
1992                 inode->i_uid = default_uid;
1993                 inode->i_gid = default_gid;
1994                 inode->i_atime = inode->i_mtime = inode->i_ctime
1995                                 = CURRENT_TIME;
1996                 inode->i_private = data;
1997                 inode->i_fop = fops;
1998         }
1999         return inode;
2000 }
2001
2002 /* creates in fs root directory, so non-renamable and non-linkable.
2003  * so inode and dentry are paired, until device reconfig.
2004  */
2005 static struct inode *
2006 gadgetfs_create_file (struct super_block *sb, char const *name,
2007                 void *data, const struct file_operations *fops,
2008                 struct dentry **dentry_p)
2009 {
2010         struct dentry   *dentry;
2011         struct inode    *inode;
2012
2013         dentry = d_alloc_name(sb->s_root, name);
2014         if (!dentry)
2015                 return NULL;
2016
2017         inode = gadgetfs_make_inode (sb, data, fops,
2018                         S_IFREG | (default_perm & S_IRWXUGO));
2019         if (!inode) {
2020                 dput(dentry);
2021                 return NULL;
2022         }
2023         d_add (dentry, inode);
2024         *dentry_p = dentry;
2025         return inode;
2026 }
2027
2028 static const struct super_operations gadget_fs_operations = {
2029         .statfs =       simple_statfs,
2030         .drop_inode =   generic_delete_inode,
2031 };
2032
2033 static int
2034 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2035 {
2036         struct inode    *inode;
2037         struct dev_data *dev;
2038
2039         if (the_device)
2040                 return -ESRCH;
2041
2042         /* fake probe to determine $CHIP */
2043         (void) usb_gadget_probe_driver(&probe_driver, gadgetfs_probe);
2044         if (!CHIP)
2045                 return -ENODEV;
2046
2047         /* superblock */
2048         sb->s_blocksize = PAGE_CACHE_SIZE;
2049         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2050         sb->s_magic = GADGETFS_MAGIC;
2051         sb->s_op = &gadget_fs_operations;
2052         sb->s_time_gran = 1;
2053
2054         /* root inode */
2055         inode = gadgetfs_make_inode (sb,
2056                         NULL, &simple_dir_operations,
2057                         S_IFDIR | S_IRUGO | S_IXUGO);
2058         if (!inode)
2059                 goto Enomem;
2060         inode->i_op = &simple_dir_inode_operations;
2061         if (!(sb->s_root = d_make_root (inode)))
2062                 goto Enomem;
2063
2064         /* the ep0 file is named after the controller we expect;
2065          * user mode code can use it for sanity checks, like we do.
2066          */
2067         dev = dev_new ();
2068         if (!dev)
2069                 goto Enomem;
2070
2071         dev->sb = sb;
2072         if (!gadgetfs_create_file (sb, CHIP,
2073                                 dev, &dev_init_operations,
2074                                 &dev->dentry)) {
2075                 put_dev(dev);
2076                 goto Enomem;
2077         }
2078
2079         /* other endpoint files are available after hardware setup,
2080          * from binding to a controller.
2081          */
2082         the_device = dev;
2083         return 0;
2084
2085 Enomem:
2086         return -ENOMEM;
2087 }
2088
2089 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2090 static struct dentry *
2091 gadgetfs_mount (struct file_system_type *t, int flags,
2092                 const char *path, void *opts)
2093 {
2094         return mount_single (t, flags, opts, gadgetfs_fill_super);
2095 }
2096
2097 static void
2098 gadgetfs_kill_sb (struct super_block *sb)
2099 {
2100         kill_litter_super (sb);
2101         if (the_device) {
2102                 put_dev (the_device);
2103                 the_device = NULL;
2104         }
2105 }
2106
2107 /*----------------------------------------------------------------------*/
2108
2109 static struct file_system_type gadgetfs_type = {
2110         .owner          = THIS_MODULE,
2111         .name           = shortname,
2112         .mount          = gadgetfs_mount,
2113         .kill_sb        = gadgetfs_kill_sb,
2114 };
2115
2116 /*----------------------------------------------------------------------*/
2117
2118 static int __init init (void)
2119 {
2120         int status;
2121
2122         status = register_filesystem (&gadgetfs_type);
2123         if (status == 0)
2124                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2125                         shortname, driver_desc);
2126         return status;
2127 }
2128 module_init (init);
2129
2130 static void __exit cleanup (void)
2131 {
2132         pr_debug ("unregister %s\n", shortname);
2133         unregister_filesystem (&gadgetfs_type);
2134 }
2135 module_exit (cleanup);
2136