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->iv);
 574         kfree(priv);
 575         return len;
 576 }
 577
 578 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 579 {
 580         struct kiocb            *iocb = req->context;
 581         struct kiocb_priv       *priv = iocb->private;
 582         struct ep_data          *epdata = priv->epdata;
 583
 584         /* lock against disconnect (and ideally, cancel) */
 585         spin_lock(&epdata->dev->lock);
 586         priv->req = NULL;
 587         priv->epdata = NULL;
 588
 589         /* if this was a write or a read returning no data then we
 590          * don't need to copy anything to userspace, so we can
 591          * complete the aio request immediately.
 592          */
 593         if (priv->iv == NULL || unlikely(req->actual == 0)) {
 594                 kfree(req->buf);
 595                 kfree(priv->iv);
 596                 kfree(priv);
 597                 iocb->private = NULL;
 598                 /* aio_complete() reports bytes-transferred _and_ faults */
 599                 aio_complete(iocb, req->actual ? req->actual : req->status,
 600                                 req->status);
 601         } else {
 602                 /* retry() won't report both; so we hide some faults */
 603                 if (unlikely(0 != req->status))
 604                         DBG(epdata->dev, "%s fault %d len %d\n",
 605                                 ep->name, req->status, req->actual);
 606
 607                 priv->buf = req->buf;
 608                 priv->actual = req->actual;
 609                 kick_iocb(iocb);
 610         }
 611         spin_unlock(&epdata->dev->lock);
 612
 613         usb_ep_free_request(ep, req);
 614         put_ep(epdata);
 615 }
 616
 617 static ssize_t
 618 ep_aio_rwtail(
 619         struct kiocb    *iocb,
 620         char            *buf,
 621         size_t          len,
 622         struct ep_data  *epdata,
 623         const struct iovec *iv,
 624         unsigned long   nr_segs
 625 )
 626 {
 627         struct kiocb_priv       *priv;
 628         struct usb_request      *req;
 629         ssize_t                 value;
 630
 631         priv = kzalloc(sizeof *priv, GFP_KERNEL);
 632         if (!priv) {
 633                 value = -ENOMEM;
 634 fail:
 635                 kfree(buf);
 636                 return value;
 637         }
 638         iocb->private = priv;
 639         if (iv) {
 640                 priv->iv = kmemdup(iv, nr_segs * sizeof(struct iovec),
 641                                    GFP_KERNEL);
 642                 if (!priv->iv) {
 643                         kfree(priv);
 644                         goto fail;
 645                 }
 646         }
 647         priv->nr_segs = nr_segs;
 648
 649         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 650         if (unlikely(value < 0)) {
 651                 kfree(priv->iv);
 652                 kfree(priv);
 653                 goto fail;
 654         }
 655
 656         iocb->ki_cancel = ep_aio_cancel;
 657         get_ep(epdata);
 658         priv->epdata = epdata;
 659         priv->actual = 0;
 660
 661         /* each kiocb is coupled to one usb_request, but we can't
 662          * allocate or submit those if the host disconnected.
 663          */
 664         spin_lock_irq(&epdata->dev->lock);
 665         if (likely(epdata->ep)) {
 666                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 667                 if (likely(req)) {
 668                         priv->req = req;
 669                         req->buf = buf;
 670                         req->length = len;
 671                         req->complete = ep_aio_complete;
 672                         req->context = iocb;
 673                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 674                         if (unlikely(0 != value))
 675                                 usb_ep_free_request(epdata->ep, req);
 676                 } else
 677                         value = -EAGAIN;
 678         } else
 679                 value = -ENODEV;
 680         spin_unlock_irq(&epdata->dev->lock);
 681
 682         mutex_unlock(&epdata->lock);
 683
 684         if (unlikely(value)) {
 685                 kfree(priv->iv);
 686                 kfree(priv);
 687                 put_ep(epdata);
 688         } else
 689                 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
 690         return value;
 691 }
 692
 693 static ssize_t
 694 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
 695                 unsigned long nr_segs, loff_t o)
 696 {
 697         struct ep_data          *epdata = iocb->ki_filp->private_data;
 698         char                    *buf;
 699
 700         if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
 701                 return -EINVAL;
 702
 703         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 704         if (unlikely(!buf))
 705                 return -ENOMEM;
 706
 707         iocb->ki_retry = ep_aio_read_retry;
 708         return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
 709 }
 710
 711 static ssize_t
 712 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
 713                 unsigned long nr_segs, loff_t o)
 714 {
 715         struct ep_data          *epdata = iocb->ki_filp->private_data;
 716         char                    *buf;
 717         size_t                  len = 0;
 718         int                     i = 0;
 719
 720         if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
 721                 return -EINVAL;
 722
 723         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 724         if (unlikely(!buf))
 725                 return -ENOMEM;
 726
 727         for (i=0; i < nr_segs; i++) {
 728                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
 729                                 iov[i].iov_len) != 0)) {
 730                         kfree(buf);
 731                         return -EFAULT;
 732                 }
 733                 len += iov[i].iov_len;
 734         }
 735         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
 736 }
 737
 738 /*----------------------------------------------------------------------*/
 739
 740 /* used after endpoint configuration */
 741 static const struct file_operations ep_io_operations = {
 742         .owner =        THIS_MODULE,
 743         .llseek =       no_llseek,
 744
 745         .read =         ep_read,
 746         .write =        ep_write,
 747         .unlocked_ioctl = ep_ioctl,
 748         .release =      ep_release,
 749
 750         .aio_read =     ep_aio_read,
 751         .aio_write =    ep_aio_write,
 752 };
 753
 754 /* ENDPOINT INITIALIZATION
 755  *
 756  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 757  *     status = write (fd, descriptors, sizeof descriptors)
 758  *
 759  * That write establishes the endpoint configuration, configuring
 760  * the controller to process bulk, interrupt, or isochronous transfers
 761  * at the right maxpacket size, and so on.
 762  *
 763  * The descriptors are message type 1, identified by a host order u32
 764  * at the beginning of what's written.  Descriptor order is: full/low
 765  * speed descriptor, then optional high speed descriptor.
 766  */
 767 static ssize_t
 768 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 769 {
 770         struct ep_data          *data = fd->private_data;
 771         struct usb_ep           *ep;
 772         u32                     tag;
 773         int                     value, length = len;
 774
 775         value = mutex_lock_interruptible(&data->lock);
 776         if (value < 0)
 777                 return value;
 778
 779         if (data->state != STATE_EP_READY) {
 780                 value = -EL2HLT;
 781                 goto fail;
 782         }
 783
 784         value = len;
 785         if (len < USB_DT_ENDPOINT_SIZE + 4)
 786                 goto fail0;
 787
 788         /* we might need to change message format someday */
 789         if (copy_from_user (&tag, buf, 4)) {
 790                 goto fail1;
 791         }
 792         if (tag != 1) {
 793                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 794                 goto fail0;
 795         }
 796         buf += 4;
 797         len -= 4;
 798
 799         /* NOTE:  audio endpoint extensions not accepted here;
 800          * just don't include the extra bytes.
 801          */
 802
 803         /* full/low speed descriptor, then high speed */
 804         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 805                 goto fail1;
 806         }
 807         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 808                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 809                 goto fail0;
 810         if (len != USB_DT_ENDPOINT_SIZE) {
 811                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 812                         goto fail0;
 813                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 814                                         USB_DT_ENDPOINT_SIZE)) {
 815                         goto fail1;
 816                 }
 817                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 818                                 || data->hs_desc.bDescriptorType
 819                                         != USB_DT_ENDPOINT) {
 820                         DBG(data->dev, "config %s, bad hs length or type\n",
 821                                         data->name);
 822                         goto fail0;
 823                 }
 824         }
 825
 826         spin_lock_irq (&data->dev->lock);
 827         if (data->dev->state == STATE_DEV_UNBOUND) {
 828                 value = -ENOENT;
 829                 goto gone;
 830         } else if ((ep = data->ep) == NULL) {
 831                 value = -ENODEV;
 832                 goto gone;
 833         }
 834         switch (data->dev->gadget->speed) {
 835         case USB_SPEED_LOW:
 836         case USB_SPEED_FULL:
 837                 ep->desc = &data->desc;
 838                 value = usb_ep_enable(ep);
 839                 if (value == 0)
 840                         data->state = STATE_EP_ENABLED;
 841                 break;
 842 #ifdef  CONFIG_USB_GADGET_DUALSPEED
 843         case USB_SPEED_HIGH:
 844                 /* fails if caller didn't provide that descriptor... */
 845                 ep->desc = &data->hs_desc;
 846                 value = usb_ep_enable(ep);
 847                 if (value == 0)
 848                         data->state = STATE_EP_ENABLED;
 849                 break;
 850 #endif
 851         default:
 852                 DBG(data->dev, "unconnected, %s init abandoned\n",
 853                                 data->name);
 854                 value = -EINVAL;
 855         }
 856         if (value == 0) {
 857                 fd->f_op = &ep_io_operations;
 858                 value = length;
 859         }
 860 gone:
 861         spin_unlock_irq (&data->dev->lock);
 862         if (value < 0) {
 863 fail:
 864                 data->desc.bDescriptorType = 0;
 865                 data->hs_desc.bDescriptorType = 0;
 866         }
 867         mutex_unlock(&data->lock);
 868         return value;
 869 fail0:
 870         value = -EINVAL;
 871         goto fail;
 872 fail1:
 873         value = -EFAULT;
 874         goto fail;
 875 }
 876
 877 static int
 878 ep_open (struct inode *inode, struct file *fd)
 879 {
 880         struct ep_data          *data = inode->i_private;
 881         int                     value = -EBUSY;
 882
 883         if (mutex_lock_interruptible(&data->lock) != 0)
 884                 return -EINTR;
 885         spin_lock_irq (&data->dev->lock);
 886         if (data->dev->state == STATE_DEV_UNBOUND)
 887                 value = -ENOENT;
 888         else if (data->state == STATE_EP_DISABLED) {
 889                 value = 0;
 890                 data->state = STATE_EP_READY;
 891                 get_ep (data);
 892                 fd->private_data = data;
 893                 VDEBUG (data->dev, "%s ready\n", data->name);
 894         } else
 895                 DBG (data->dev, "%s state %d\n",
 896                         data->name, data->state);
 897         spin_unlock_irq (&data->dev->lock);
 898         mutex_unlock(&data->lock);
 899         return value;
 900 }
 901
 902 /* used before endpoint configuration */
 903 static const struct file_operations ep_config_operations = {
 904         .owner =        THIS_MODULE,
 905         .llseek =       no_llseek,
 906
 907         .open =         ep_open,
 908         .write =        ep_config,
 909         .release =      ep_release,
 910 };
 911
 912 /*----------------------------------------------------------------------*/
 913
 914 /* EP0 IMPLEMENTATION can be partly in userspace.
 915  *
 916  * Drivers that use this facility receive various events, including
 917  * control requests the kernel doesn't handle.  Drivers that don't
 918  * use this facility may be too simple-minded for real applications.
 919  */
 920
 921 static inline void ep0_readable (struct dev_data *dev)
 922 {
 923         wake_up (&dev->wait);
 924         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 925 }
 926
 927 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 928 {
 929         struct dev_data         *dev = ep->driver_data;
 930
 931         if (req->buf != dev->rbuf) {
 932                 kfree(req->buf);
 933                 req->buf = dev->rbuf;
 934                 req->dma = DMA_ADDR_INVALID;
 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                 len = min_t(size_t, len, dev->setup_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         /* other endpoints were all decoupled from this device */
1270         spin_lock_irq(&dev->lock);
1271         dev->state = STATE_DEV_DISABLED;
1272         spin_unlock_irq(&dev->lock);
1273         return 0;
1274 }
1275
1276 static unsigned int
1277 ep0_poll (struct file *fd, poll_table *wait)
1278 {
1279        struct dev_data         *dev = fd->private_data;
1280        int                     mask = 0;
1281
1282        poll_wait(fd, &dev->wait, wait);
1283
1284        spin_lock_irq (&dev->lock);
1285
1286        /* report fd mode change before acting on it */
1287        if (dev->setup_abort) {
1288                dev->setup_abort = 0;
1289                mask = POLLHUP;
1290                goto out;
1291        }
1292
1293        if (dev->state == STATE_DEV_SETUP) {
1294                if (dev->setup_in || dev->setup_can_stall)
1295                        mask = POLLOUT;
1296        } else {
1297                if (dev->ev_next != 0)
1298                        mask = POLLIN;
1299        }
1300 out:
1301        spin_unlock_irq(&dev->lock);
1302        return mask;
1303 }
1304
1305 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1306 {
1307         struct dev_data         *dev = fd->private_data;
1308         struct usb_gadget       *gadget = dev->gadget;
1309         long ret = -ENOTTY;
1310
1311         if (gadget->ops->ioctl)
1312                 ret = gadget->ops->ioctl (gadget, code, value);
1313
1314         return ret;
1315 }
1316
1317 /* used after device configuration */
1318 static const struct file_operations ep0_io_operations = {
1319         .owner =        THIS_MODULE,
1320         .llseek =       no_llseek,
1321
1322         .read =         ep0_read,
1323         .write =        ep0_write,
1324         .fasync =       ep0_fasync,
1325         .poll =         ep0_poll,
1326         .unlocked_ioctl =       dev_ioctl,
1327         .release =      dev_release,
1328 };
1329
1330 /*----------------------------------------------------------------------*/
1331
1332 /* The in-kernel gadget driver handles most ep0 issues, in particular
1333  * enumerating the single configuration (as provided from user space).
1334  *
1335  * Unrecognized ep0 requests may be handled in user space.
1336  */
1337
1338 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1339 static void make_qualifier (struct dev_data *dev)
1340 {
1341         struct usb_qualifier_descriptor         qual;
1342         struct usb_device_descriptor            *desc;
1343
1344         qual.bLength = sizeof qual;
1345         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1346         qual.bcdUSB = cpu_to_le16 (0x0200);
1347
1348         desc = dev->dev;
1349         qual.bDeviceClass = desc->bDeviceClass;
1350         qual.bDeviceSubClass = desc->bDeviceSubClass;
1351         qual.bDeviceProtocol = desc->bDeviceProtocol;
1352
1353         /* assumes ep0 uses the same value for both speeds ... */
1354         qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1355
1356         qual.bNumConfigurations = 1;
1357         qual.bRESERVED = 0;
1358
1359         memcpy (dev->rbuf, &qual, sizeof qual);
1360 }
1361 #endif
1362
1363 static int
1364 config_buf (struct dev_data *dev, u8 type, unsigned index)
1365 {
1366         int             len;
1367         int             hs = 0;
1368
1369         /* only one configuration */
1370         if (index > 0)
1371                 return -EINVAL;
1372
1373         if (gadget_is_dualspeed(dev->gadget)) {
1374                 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1375                 if (type == USB_DT_OTHER_SPEED_CONFIG)
1376                         hs = !hs;
1377         }
1378         if (hs) {
1379                 dev->req->buf = dev->hs_config;
1380                 len = le16_to_cpu(dev->hs_config->wTotalLength);
1381         } else {
1382                 dev->req->buf = dev->config;
1383                 len = le16_to_cpu(dev->config->wTotalLength);
1384         }
1385         ((u8 *)dev->req->buf) [1] = type;
1386         return len;
1387 }
1388
1389 static int
1390 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1391 {
1392         struct dev_data                 *dev = get_gadget_data (gadget);
1393         struct usb_request              *req = dev->req;
1394         int                             value = -EOPNOTSUPP;
1395         struct usb_gadgetfs_event       *event;
1396         u16                             w_value = le16_to_cpu(ctrl->wValue);
1397         u16                             w_length = le16_to_cpu(ctrl->wLength);
1398
1399         spin_lock (&dev->lock);
1400         dev->setup_abort = 0;
1401         if (dev->state == STATE_DEV_UNCONNECTED) {
1402                 if (gadget_is_dualspeed(gadget)
1403                                 && gadget->speed == USB_SPEED_HIGH
1404                                 && dev->hs_config == NULL) {
1405                         spin_unlock(&dev->lock);
1406                         ERROR (dev, "no high speed config??\n");
1407                         return -EINVAL;
1408                 }
1409
1410                 dev->state = STATE_DEV_CONNECTED;
1411
1412                 INFO (dev, "connected\n");
1413                 event = next_event (dev, GADGETFS_CONNECT);
1414                 event->u.speed = gadget->speed;
1415                 ep0_readable (dev);
1416
1417         /* host may have given up waiting for response.  we can miss control
1418          * requests handled lower down (device/endpoint status and features);
1419          * then ep0_{read,write} will report the wrong status. controller
1420          * driver will have aborted pending i/o.
1421          */
1422         } else if (dev->state == STATE_DEV_SETUP)
1423                 dev->setup_abort = 1;
1424
1425         req->buf = dev->rbuf;
1426         req->dma = DMA_ADDR_INVALID;
1427         req->context = NULL;
1428         value = -EOPNOTSUPP;
1429         switch (ctrl->bRequest) {
1430
1431         case USB_REQ_GET_DESCRIPTOR:
1432                 if (ctrl->bRequestType != USB_DIR_IN)
1433                         goto unrecognized;
1434                 switch (w_value >> 8) {
1435
1436                 case USB_DT_DEVICE:
1437                         value = min (w_length, (u16) sizeof *dev->dev);
1438                         dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1439                         req->buf = dev->dev;
1440                         break;
1441 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1442                 case USB_DT_DEVICE_QUALIFIER:
1443                         if (!dev->hs_config)
1444                                 break;
1445                         value = min (w_length, (u16)
1446                                 sizeof (struct usb_qualifier_descriptor));
1447                         make_qualifier (dev);
1448                         break;
1449                 case USB_DT_OTHER_SPEED_CONFIG:
1450                         // FALLTHROUGH
1451 #endif
1452                 case USB_DT_CONFIG:
1453                         value = config_buf (dev,
1454                                         w_value >> 8,
1455                                         w_value & 0xff);
1456                         if (value >= 0)
1457                                 value = min (w_length, (u16) value);
1458                         break;
1459                 case USB_DT_STRING:
1460                         goto unrecognized;
1461
1462                 default:                // all others are errors
1463                         break;
1464                 }
1465                 break;
1466
1467         /* currently one config, two speeds */
1468         case USB_REQ_SET_CONFIGURATION:
1469                 if (ctrl->bRequestType != 0)
1470                         goto unrecognized;
1471                 if (0 == (u8) w_value) {
1472                         value = 0;
1473                         dev->current_config = 0;
1474                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1475                         // user mode expected to disable endpoints
1476                 } else {
1477                         u8      config, power;
1478
1479                         if (gadget_is_dualspeed(gadget)
1480                                         && gadget->speed == USB_SPEED_HIGH) {
1481                                 config = dev->hs_config->bConfigurationValue;
1482                                 power = dev->hs_config->bMaxPower;
1483                         } else {
1484                                 config = dev->config->bConfigurationValue;
1485                                 power = dev->config->bMaxPower;
1486                         }
1487
1488                         if (config == (u8) w_value) {
1489                                 value = 0;
1490                                 dev->current_config = config;
1491                                 usb_gadget_vbus_draw(gadget, 2 * power);
1492                         }
1493                 }
1494
1495                 /* report SET_CONFIGURATION like any other control request,
1496                  * except that usermode may not stall this.  the next
1497                  * request mustn't be allowed start until this finishes:
1498                  * endpoints and threads set up, etc.
1499                  *
1500                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1501                  * has bad/racey automagic that prevents synchronizing here.
1502                  * even kernel mode drivers often miss them.
1503                  */
1504                 if (value == 0) {
1505                         INFO (dev, "configuration #%d\n", dev->current_config);
1506                         if (dev->usermode_setup) {
1507                                 dev->setup_can_stall = 0;
1508                                 goto delegate;
1509                         }
1510                 }
1511                 break;
1512
1513 #ifndef CONFIG_USB_GADGET_PXA25X
1514         /* PXA automagically handles this request too */
1515         case USB_REQ_GET_CONFIGURATION:
1516                 if (ctrl->bRequestType != 0x80)
1517                         goto unrecognized;
1518                 *(u8 *)req->buf = dev->current_config;
1519                 value = min (w_length, (u16) 1);
1520                 break;
1521 #endif
1522
1523         default:
1524 unrecognized:
1525                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1526                         dev->usermode_setup ? "delegate" : "fail",
1527                         ctrl->bRequestType, ctrl->bRequest,
1528                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1529
1530                 /* if there's an ep0 reader, don't stall */
1531                 if (dev->usermode_setup) {
1532                         dev->setup_can_stall = 1;
1533 delegate:
1534                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1535                                                 ? 1 : 0;
1536                         dev->setup_wLength = w_length;
1537                         dev->setup_out_ready = 0;
1538                         dev->setup_out_error = 0;
1539                         value = 0;
1540
1541                         /* read DATA stage for OUT right away */
1542                         if (unlikely (!dev->setup_in && w_length)) {
1543                                 value = setup_req (gadget->ep0, dev->req,
1544                                                         w_length);
1545                                 if (value < 0)
1546                                         break;
1547                                 value = usb_ep_queue (gadget->ep0, dev->req,
1548                                                         GFP_ATOMIC);
1549                                 if (value < 0) {
1550                                         clean_req (gadget->ep0, dev->req);
1551                                         break;
1552                                 }
1553
1554                                 /* we can't currently stall these */
1555                                 dev->setup_can_stall = 0;
1556                         }
1557
1558                         /* state changes when reader collects event */
1559                         event = next_event (dev, GADGETFS_SETUP);
1560                         event->u.setup = *ctrl;
1561                         ep0_readable (dev);
1562                         spin_unlock (&dev->lock);
1563                         return 0;
1564                 }
1565         }
1566
1567         /* proceed with data transfer and status phases? */
1568         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1569                 req->length = value;
1570                 req->zero = value < w_length;
1571                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1572                 if (value < 0) {
1573                         DBG (dev, "ep_queue --> %d\n", value);
1574                         req->status = 0;
1575                 }
1576         }
1577
1578         /* device stalls when value < 0 */
1579         spin_unlock (&dev->lock);
1580         return value;
1581 }
1582
1583 static void destroy_ep_files (struct dev_data *dev)
1584 {
1585         struct list_head        *entry, *tmp;
1586
1587         DBG (dev, "%s %d\n", __func__, dev->state);
1588
1589         /* dev->state must prevent interference */
1590 restart:
1591         spin_lock_irq (&dev->lock);
1592         list_for_each_safe (entry, tmp, &dev->epfiles) {
1593                 struct ep_data  *ep;
1594                 struct inode    *parent;
1595                 struct dentry   *dentry;
1596
1597                 /* break link to FS */
1598                 ep = list_entry (entry, struct ep_data, epfiles);
1599                 list_del_init (&ep->epfiles);
1600                 dentry = ep->dentry;
1601                 ep->dentry = NULL;
1602                 parent = dentry->d_parent->d_inode;
1603
1604                 /* break link to controller */
1605                 if (ep->state == STATE_EP_ENABLED)
1606                         (void) usb_ep_disable (ep->ep);
1607                 ep->state = STATE_EP_UNBOUND;
1608                 usb_ep_free_request (ep->ep, ep->req);
1609                 ep->ep = NULL;
1610                 wake_up (&ep->wait);
1611                 put_ep (ep);
1612
1613                 spin_unlock_irq (&dev->lock);
1614
1615                 /* break link to dcache */
1616                 mutex_lock (&parent->i_mutex);
1617                 d_delete (dentry);
1618                 dput (dentry);
1619                 mutex_unlock (&parent->i_mutex);
1620
1621                 /* fds may still be open */
1622                 goto restart;
1623         }
1624         spin_unlock_irq (&dev->lock);
1625 }
1626
1627
1628 static struct inode *
1629 gadgetfs_create_file (struct super_block *sb, char const *name,
1630                 void *data, const struct file_operations *fops,
1631                 struct dentry **dentry_p);
1632
1633 static int activate_ep_files (struct dev_data *dev)
1634 {
1635         struct usb_ep   *ep;
1636         struct ep_data  *data;
1637
1638         gadget_for_each_ep (ep, dev->gadget) {
1639
1640                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1641                 if (!data)
1642                         goto enomem0;
1643                 data->state = STATE_EP_DISABLED;
1644                 mutex_init(&data->lock);
1645                 init_waitqueue_head (&data->wait);
1646
1647                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1648                 atomic_set (&data->count, 1);
1649                 data->dev = dev;
1650                 get_dev (dev);
1651
1652                 data->ep = ep;
1653                 ep->driver_data = data;
1654
1655                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1656                 if (!data->req)
1657                         goto enomem1;
1658
1659                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1660                                 data, &ep_config_operations,
1661                                 &data->dentry);
1662                 if (!data->inode)
1663                         goto enomem2;
1664                 list_add_tail (&data->epfiles, &dev->epfiles);
1665         }
1666         return 0;
1667
1668 enomem2:
1669         usb_ep_free_request (ep, data->req);
1670 enomem1:
1671         put_dev (dev);
1672         kfree (data);
1673 enomem0:
1674         DBG (dev, "%s enomem\n", __func__);
1675         destroy_ep_files (dev);
1676         return -ENOMEM;
1677 }
1678
1679 static void
1680 gadgetfs_unbind (struct usb_gadget *gadget)
1681 {
1682         struct dev_data         *dev = get_gadget_data (gadget);
1683
1684         DBG (dev, "%s\n", __func__);
1685
1686         spin_lock_irq (&dev->lock);
1687         dev->state = STATE_DEV_UNBOUND;
1688         spin_unlock_irq (&dev->lock);
1689
1690         destroy_ep_files (dev);
1691         gadget->ep0->driver_data = NULL;
1692         set_gadget_data (gadget, NULL);
1693
1694         /* we've already been disconnected ... no i/o is active */
1695         if (dev->req)
1696                 usb_ep_free_request (gadget->ep0, dev->req);
1697         DBG (dev, "%s done\n", __func__);
1698         put_dev (dev);
1699 }
1700
1701 static struct dev_data          *the_device;
1702
1703 static int
1704 gadgetfs_bind (struct usb_gadget *gadget)
1705 {
1706         struct dev_data         *dev = the_device;
1707
1708         if (!dev)
1709                 return -ESRCH;
1710         if (0 != strcmp (CHIP, gadget->name)) {
1711                 pr_err("%s expected %s controller not %s\n",
1712                         shortname, CHIP, gadget->name);
1713                 return -ENODEV;
1714         }
1715
1716         set_gadget_data (gadget, dev);
1717         dev->gadget = gadget;
1718         gadget->ep0->driver_data = dev;
1719
1720         /* preallocate control response and buffer */
1721         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1722         if (!dev->req)
1723                 goto enomem;
1724         dev->req->context = NULL;
1725         dev->req->complete = epio_complete;
1726
1727         if (activate_ep_files (dev) < 0)
1728                 goto enomem;
1729
1730         INFO (dev, "bound to %s driver\n", gadget->name);
1731         spin_lock_irq(&dev->lock);
1732         dev->state = STATE_DEV_UNCONNECTED;
1733         spin_unlock_irq(&dev->lock);
1734         get_dev (dev);
1735         return 0;
1736
1737 enomem:
1738         gadgetfs_unbind (gadget);
1739         return -ENOMEM;
1740 }
1741
1742 static void
1743 gadgetfs_disconnect (struct usb_gadget *gadget)
1744 {
1745         struct dev_data         *dev = get_gadget_data (gadget);
1746         unsigned long           flags;
1747
1748         spin_lock_irqsave (&dev->lock, flags);
1749         if (dev->state == STATE_DEV_UNCONNECTED)
1750                 goto exit;
1751         dev->state = STATE_DEV_UNCONNECTED;
1752
1753         INFO (dev, "disconnected\n");
1754         next_event (dev, GADGETFS_DISCONNECT);
1755         ep0_readable (dev);
1756 exit:
1757         spin_unlock_irqrestore (&dev->lock, flags);
1758 }
1759
1760 static void
1761 gadgetfs_suspend (struct usb_gadget *gadget)
1762 {
1763         struct dev_data         *dev = get_gadget_data (gadget);
1764
1765         INFO (dev, "suspended from state %d\n", dev->state);
1766         spin_lock (&dev->lock);
1767         switch (dev->state) {
1768         case STATE_DEV_SETUP:           // VERY odd... host died??
1769         case STATE_DEV_CONNECTED:
1770         case STATE_DEV_UNCONNECTED:
1771                 next_event (dev, GADGETFS_SUSPEND);
1772                 ep0_readable (dev);
1773                 /* FALLTHROUGH */
1774         default:
1775                 break;
1776         }
1777         spin_unlock (&dev->lock);
1778 }
1779
1780 static struct usb_gadget_driver gadgetfs_driver = {
1781 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1782         .speed          = USB_SPEED_HIGH,
1783 #else
1784         .speed          = USB_SPEED_FULL,
1785 #endif
1786         .function       = (char *) driver_desc,
1787         .unbind         = gadgetfs_unbind,
1788         .setup          = gadgetfs_setup,
1789         .disconnect     = gadgetfs_disconnect,
1790         .suspend        = gadgetfs_suspend,
1791
1792         .driver = {
1793                 .name           = (char *) shortname,
1794         },
1795 };
1796
1797 /*----------------------------------------------------------------------*/
1798
1799 static void gadgetfs_nop(struct usb_gadget *arg) { }
1800
1801 static int gadgetfs_probe (struct usb_gadget *gadget)
1802 {
1803         CHIP = gadget->name;
1804         return -EISNAM;
1805 }
1806
1807 static struct usb_gadget_driver probe_driver = {
1808         .speed          = USB_SPEED_HIGH,
1809         .unbind         = gadgetfs_nop,
1810         .setup          = (void *)gadgetfs_nop,
1811         .disconnect     = gadgetfs_nop,
1812         .driver = {
1813                 .name           = "nop",
1814         },
1815 };
1816
1817
1818 /* DEVICE INITIALIZATION
1819  *
1820  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1821  *     status = write (fd, descriptors, sizeof descriptors)
1822  *
1823  * That write establishes the device configuration, so the kernel can
1824  * bind to the controller ... guaranteeing it can handle enumeration
1825  * at all necessary speeds.  Descriptor order is:
1826  *
1827  * . message tag (u32, host order) ... for now, must be zero; it
1828  *      would change to support features like multi-config devices
1829  * . full/low speed config ... all wTotalLength bytes (with interface,
1830  *      class, altsetting, endpoint, and other descriptors)
1831  * . high speed config ... all descriptors, for high speed operation;
1832  *      this one's optional except for high-speed hardware
1833  * . device descriptor
1834  *
1835  * Endpoints are not yet enabled. Drivers must wait until device
1836  * configuration and interface altsetting changes create
1837  * the need to configure (or unconfigure) them.
1838  *
1839  * After initialization, the device stays active for as long as that
1840  * $CHIP file is open.  Events must then be read from that descriptor,
1841  * such as configuration notifications.
1842  */
1843
1844 static int is_valid_config (struct usb_config_descriptor *config)
1845 {
1846         return config->bDescriptorType == USB_DT_CONFIG
1847                 && config->bLength == USB_DT_CONFIG_SIZE
1848                 && config->bConfigurationValue != 0
1849                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1850                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1851         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1852         /* FIXME check lengths: walk to end */
1853 }
1854
1855 static ssize_t
1856 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1857 {
1858         struct dev_data         *dev = fd->private_data;
1859         ssize_t                 value = len, length = len;
1860         unsigned                total;
1861         u32                     tag;
1862         char                    *kbuf;
1863
1864         if ((len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) ||
1865             (len > PAGE_SIZE * 4))
1866                 return -EINVAL;
1867
1868         /* we might need to change message format someday */
1869         if (copy_from_user (&tag, buf, 4))
1870                 return -EFAULT;
1871         if (tag != 0)
1872                 return -EINVAL;
1873         buf += 4;
1874         length -= 4;
1875
1876         kbuf = memdup_user(buf, length);
1877         if (IS_ERR(kbuf))
1878                 return PTR_ERR(kbuf);
1879
1880         spin_lock_irq (&dev->lock);
1881         value = -EINVAL;
1882         if (dev->buf)
1883                 goto fail;
1884         dev->buf = kbuf;
1885
1886         /* full or low speed config */
1887         dev->config = (void *) kbuf;
1888         total = le16_to_cpu(dev->config->wTotalLength);
1889         if (!is_valid_config (dev->config) || total >= length)
1890                 goto fail;
1891         kbuf += total;
1892         length -= total;
1893
1894         /* optional high speed config */
1895         if (kbuf [1] == USB_DT_CONFIG) {
1896                 dev->hs_config = (void *) kbuf;
1897                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1898                 if (!is_valid_config (dev->hs_config) || total >= length)
1899                         goto fail;
1900                 kbuf += total;
1901                 length -= total;
1902         }
1903
1904         /* could support multiple configs, using another encoding! */
1905
1906         /* device descriptor (tweaked for paranoia) */
1907         if (length != USB_DT_DEVICE_SIZE)
1908                 goto fail;
1909         dev->dev = (void *)kbuf;
1910         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1911                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1912                         || dev->dev->bNumConfigurations != 1)
1913                 goto fail;
1914         dev->dev->bNumConfigurations = 1;
1915         dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1916
1917         /* triggers gadgetfs_bind(); then we can enumerate. */
1918         spin_unlock_irq (&dev->lock);
1919         value = usb_gadget_probe_driver(&gadgetfs_driver, gadgetfs_bind);
1920         if (value != 0) {
1921                 kfree (dev->buf);
1922                 dev->buf = NULL;
1923         } else {
1924                 /* at this point "good" hardware has for the first time
1925                  * let the USB the host see us.  alternatively, if users
1926                  * unplug/replug that will clear all the error state.
1927                  *
1928                  * note:  everything running before here was guaranteed
1929                  * to choke driver model style diagnostics.  from here
1930                  * on, they can work ... except in cleanup paths that
1931                  * kick in after the ep0 descriptor is closed.
1932                  */
1933                 fd->f_op = &ep0_io_operations;
1934                 value = len;
1935         }
1936         return value;
1937
1938 fail:
1939         spin_unlock_irq (&dev->lock);
1940         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1941         kfree (dev->buf);
1942         dev->buf = NULL;
1943         return value;
1944 }
1945
1946 static int
1947 dev_open (struct inode *inode, struct file *fd)
1948 {
1949         struct dev_data         *dev = inode->i_private;
1950         int                     value = -EBUSY;
1951
1952         spin_lock_irq(&dev->lock);
1953         if (dev->state == STATE_DEV_DISABLED) {
1954                 dev->ev_next = 0;
1955                 dev->state = STATE_DEV_OPENED;
1956                 fd->private_data = dev;
1957                 get_dev (dev);
1958                 value = 0;
1959         }
1960         spin_unlock_irq(&dev->lock);
1961         return value;
1962 }
1963
1964 static const struct file_operations dev_init_operations = {
1965         .owner =        THIS_MODULE,
1966         .llseek =       no_llseek,
1967
1968         .open =         dev_open,
1969         .write =        dev_config,
1970         .fasync =       ep0_fasync,
1971         .unlocked_ioctl = dev_ioctl,
1972         .release =      dev_release,
1973 };
1974
1975 /*----------------------------------------------------------------------*/
1976
1977 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1978  *
1979  * Mounting the filesystem creates a controller file, used first for
1980  * device configuration then later for event monitoring.
1981  */
1982
1983
1984 /* FIXME PAM etc could set this security policy without mount options
1985  * if epfiles inherited ownership and permissons from ep0 ...
1986  */
1987
1988 static unsigned default_uid;
1989 static unsigned default_gid;
1990 static unsigned default_perm = S_IRUSR | S_IWUSR;
1991
1992 module_param (default_uid, uint, 0644);
1993 module_param (default_gid, uint, 0644);
1994 module_param (default_perm, uint, 0644);
1995
1996
1997 static struct inode *
1998 gadgetfs_make_inode (struct super_block *sb,
1999                 void *data, const struct file_operations *fops,
2000                 int mode)
2001 {
2002         struct inode *inode = new_inode (sb);
2003
2004         if (inode) {
2005                 inode->i_ino = get_next_ino();
2006                 inode->i_mode = mode;
2007                 inode->i_uid = default_uid;
2008                 inode->i_gid = default_gid;
2009                 inode->i_atime = inode->i_mtime = inode->i_ctime
2010                                 = CURRENT_TIME;
2011                 inode->i_private = data;
2012                 inode->i_fop = fops;
2013         }
2014         return inode;
2015 }
2016
2017 /* creates in fs root directory, so non-renamable and non-linkable.
2018  * so inode and dentry are paired, until device reconfig.
2019  */
2020 static struct inode *
2021 gadgetfs_create_file (struct super_block *sb, char const *name,
2022                 void *data, const struct file_operations *fops,
2023                 struct dentry **dentry_p)
2024 {
2025         struct dentry   *dentry;
2026         struct inode    *inode;
2027
2028         dentry = d_alloc_name(sb->s_root, name);
2029         if (!dentry)
2030                 return NULL;
2031
2032         inode = gadgetfs_make_inode (sb, data, fops,
2033                         S_IFREG | (default_perm & S_IRWXUGO));
2034         if (!inode) {
2035                 dput(dentry);
2036                 return NULL;
2037         }
2038         d_add (dentry, inode);
2039         *dentry_p = dentry;
2040         return inode;
2041 }
2042
2043 static const struct super_operations gadget_fs_operations = {
2044         .statfs =       simple_statfs,
2045         .drop_inode =   generic_delete_inode,
2046 };
2047
2048 static int
2049 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2050 {
2051         struct inode    *inode;
2052         struct dentry   *d;
2053         struct dev_data *dev;
2054
2055         if (the_device)
2056                 return -ESRCH;
2057
2058         /* fake probe to determine $CHIP */
2059         (void) usb_gadget_probe_driver(&probe_driver, gadgetfs_probe);
2060         if (!CHIP)
2061                 return -ENODEV;
2062
2063         /* superblock */
2064         sb->s_blocksize = PAGE_CACHE_SIZE;
2065         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2066         sb->s_magic = GADGETFS_MAGIC;
2067         sb->s_op = &gadget_fs_operations;
2068         sb->s_time_gran = 1;
2069
2070         /* root inode */
2071         inode = gadgetfs_make_inode (sb,
2072                         NULL, &simple_dir_operations,
2073                         S_IFDIR | S_IRUGO | S_IXUGO);
2074         if (!inode)
2075                 goto enomem0;
2076         inode->i_op = &simple_dir_inode_operations;
2077         if (!(d = d_alloc_root (inode)))
2078                 goto enomem1;
2079         sb->s_root = d;
2080
2081         /* the ep0 file is named after the controller we expect;
2082          * user mode code can use it for sanity checks, like we do.
2083          */
2084         dev = dev_new ();
2085         if (!dev)
2086                 goto enomem2;
2087
2088         dev->sb = sb;
2089         if (!gadgetfs_create_file (sb, CHIP,
2090                                 dev, &dev_init_operations,
2091                                 &dev->dentry))
2092                 goto enomem3;
2093
2094         /* other endpoint files are available after hardware setup,
2095          * from binding to a controller.
2096          */
2097         the_device = dev;
2098         return 0;
2099
2100 enomem3:
2101         put_dev (dev);
2102 enomem2:
2103         dput (d);
2104 enomem1:
2105         iput (inode);
2106 enomem0:
2107         return -ENOMEM;
2108 }
2109
2110 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2111 static struct dentry *
2112 gadgetfs_mount (struct file_system_type *t, int flags,
2113                 const char *path, void *opts)
2114 {
2115         return mount_single (t, flags, opts, gadgetfs_fill_super);
2116 }
2117
2118 static void
2119 gadgetfs_kill_sb (struct super_block *sb)
2120 {
2121         kill_litter_super (sb);
2122         if (the_device) {
2123                 put_dev (the_device);
2124                 the_device = NULL;
2125         }
2126 }
2127
2128 /*----------------------------------------------------------------------*/
2129
2130 static struct file_system_type gadgetfs_type = {
2131         .owner          = THIS_MODULE,
2132         .name           = shortname,
2133         .mount          = gadgetfs_mount,
2134         .kill_sb        = gadgetfs_kill_sb,
2135 };
2136
2137 /*----------------------------------------------------------------------*/
2138
2139 static int __init init (void)
2140 {
2141         int status;
2142
2143         status = register_filesystem (&gadgetfs_type);
2144         if (status == 0)
2145                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2146                         shortname, driver_desc);
2147         return status;
2148 }
2149 module_init (init);
2150
2151 static void __exit cleanup (void)
2152 {
2153         pr_debug ("unregister %s\n", shortname);
2154         unregister_filesystem (&gadgetfs_type);
2155 }
2156 module_exit (cleanup);
2157