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   1 /*
   2  * inode.c -- user mode filesystem api for usb gadget controllers
   3  *
   4  * Copyright (C) 2003-2004 David Brownell
   5  * Copyright (C) 2003 Agilent Technologies
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22
  23 /* #define VERBOSE_DEBUG */
  24
  25 #include <linux/init.h>
  26 #include <linux/module.h>
  27 #include <linux/fs.h>
  28 #include <linux/pagemap.h>
  29 #include <linux/uts.h>
  30 #include <linux/wait.h>
  31 #include <linux/compiler.h>
  32 #include <asm/uaccess.h>
  33 #include <linux/sched.h>
  34 #include <linux/slab.h>
  35 #include <linux/poll.h>
  36 #include <linux/smp_lock.h>
  37
  38 #include <linux/device.h>
  39 #include <linux/moduleparam.h>
  40
  41 #include <linux/usb/gadgetfs.h>
  42 #include <linux/usb/gadget.h>
  43
  44
  45 /*
  46  * The gadgetfs API maps each endpoint to a file descriptor so that you
  47  * can use standard synchronous read/write calls for I/O.  There's some
  48  * O_NONBLOCK and O_ASYNC/FASYNC style i/o support.  Example usermode
  49  * drivers show how this works in practice.  You can also use AIO to
  50  * eliminate I/O gaps between requests, to help when streaming data.
  51  *
  52  * Key parts that must be USB-specific are protocols defining how the
  53  * read/write operations relate to the hardware state machines.  There
  54  * are two types of files.  One type is for the device, implementing ep0.
  55  * The other type is for each IN or OUT endpoint.  In both cases, the
  56  * user mode driver must configure the hardware before using it.
  57  *
  58  * - First, dev_config() is called when /dev/gadget/$CHIP is configured
  59  *   (by writing configuration and device descriptors).  Afterwards it
  60  *   may serve as a source of device events, used to handle all control
  61  *   requests other than basic enumeration.
  62  *
  63  * - Then, after a SET_CONFIGURATION control request, ep_config() is
  64  *   called when each /dev/gadget/ep* file is configured (by writing
  65  *   endpoint descriptors).  Afterwards these files are used to write()
  66  *   IN data or to read() OUT data.  To halt the endpoint, a "wrong
  67  *   direction" request is issued (like reading an IN endpoint).
  68  *
  69  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
  70  * not possible on all hardware.  For example, precise fault handling with
  71  * respect to data left in endpoint fifos after aborted operations; or
  72  * selective clearing of endpoint halts, to implement SET_INTERFACE.
  73  */
  74
  75 #define DRIVER_DESC     "USB Gadget filesystem"
  76 #define DRIVER_VERSION  "24 Aug 2004"
  77
  78 static const char driver_desc [] = DRIVER_DESC;
  79 static const char shortname [] = "gadgetfs";
  80
  81 MODULE_DESCRIPTION (DRIVER_DESC);
  82 MODULE_AUTHOR ("David Brownell");
  83 MODULE_LICENSE ("GPL");
  84
  85
  86 /*----------------------------------------------------------------------*/
  87
  88 #define GADGETFS_MAGIC          0xaee71ee7
  89 #define DMA_ADDR_INVALID        (~(dma_addr_t)0)
  90
  91 /* /dev/gadget/$CHIP represents ep0 and the whole device */
  92 enum ep0_state {
  93         /* DISBLED is the initial state.
  94          */
  95         STATE_DEV_DISABLED = 0,
  96
  97         /* Only one open() of /dev/gadget/$CHIP; only one file tracks
  98          * ep0/device i/o modes and binding to the controller.  Driver
  99          * must always write descriptors to initialize the device, then
 100          * the device becomes UNCONNECTED until enumeration.
 101          */
 102         STATE_DEV_OPENED,
 103
 104         /* From then on, ep0 fd is in either of two basic modes:
 105          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
 106          * - SETUP: read/write will transfer control data and succeed;
 107          *   or if "wrong direction", performs protocol stall
 108          */
 109         STATE_DEV_UNCONNECTED,
 110         STATE_DEV_CONNECTED,
 111         STATE_DEV_SETUP,
 112
 113         /* UNBOUND means the driver closed ep0, so the device won't be
 114          * accessible again (DEV_DISABLED) until all fds are closed.
 115          */
 116         STATE_DEV_UNBOUND,
 117 };
 118
 119 /* enough for the whole queue: most events invalidate others */
 120 #define N_EVENT                 5
 121
 122 struct dev_data {
 123         spinlock_t                      lock;
 124         atomic_t                        count;
 125         enum ep0_state                  state;          /* P: lock */
 126         struct usb_gadgetfs_event       event [N_EVENT];
 127         unsigned                        ev_next;
 128         struct fasync_struct            *fasync;
 129         u8                              current_config;
 130
 131         /* drivers reading ep0 MUST handle control requests (SETUP)
 132          * reported that way; else the host will time out.
 133          */
 134         unsigned                        usermode_setup : 1,
 135                                         setup_in : 1,
 136                                         setup_can_stall : 1,
 137                                         setup_out_ready : 1,
 138                                         setup_out_error : 1,
 139                                         setup_abort : 1;
 140         unsigned                        setup_wLength;
 141
 142         /* the rest is basically write-once */
 143         struct usb_config_descriptor    *config, *hs_config;
 144         struct usb_device_descriptor    *dev;
 145         struct usb_request              *req;
 146         struct usb_gadget               *gadget;
 147         struct list_head                epfiles;
 148         void                            *buf;
 149         wait_queue_head_t               wait;
 150         struct super_block              *sb;
 151         struct dentry                   *dentry;
 152
 153         /* except this scratch i/o buffer for ep0 */
 154         u8                              rbuf [256];
 155 };
 156
 157 static inline void get_dev (struct dev_data *data)
 158 {
 159         atomic_inc (&data->count);
 160 }
 161
 162 static void put_dev (struct dev_data *data)
 163 {
 164         if (likely (!atomic_dec_and_test (&data->count)))
 165                 return;
 166         /* needs no more cleanup */
 167         BUG_ON (waitqueue_active (&data->wait));
 168         kfree (data);
 169 }
 170
 171 static struct dev_data *dev_new (void)
 172 {
 173         struct dev_data         *dev;
 174
 175         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 176         if (!dev)
 177                 return NULL;
 178         dev->state = STATE_DEV_DISABLED;
 179         atomic_set (&dev->count, 1);
 180         spin_lock_init (&dev->lock);
 181         INIT_LIST_HEAD (&dev->epfiles);
 182         init_waitqueue_head (&dev->wait);
 183         return dev;
 184 }
 185
 186 /*----------------------------------------------------------------------*/
 187
 188 /* other /dev/gadget/$ENDPOINT files represent endpoints */
 189 enum ep_state {
 190         STATE_EP_DISABLED = 0,
 191         STATE_EP_READY,
 192         STATE_EP_ENABLED,
 193         STATE_EP_UNBOUND,
 194 };
 195
 196 struct ep_data {
 197         struct semaphore                lock;
 198         enum ep_state                   state;
 199         atomic_t                        count;
 200         struct dev_data                 *dev;
 201         /* must hold dev->lock before accessing ep or req */
 202         struct usb_ep                   *ep;
 203         struct usb_request              *req;
 204         ssize_t                         status;
 205         char                            name [16];
 206         struct usb_endpoint_descriptor  desc, hs_desc;
 207         struct list_head                epfiles;
 208         wait_queue_head_t               wait;
 209         struct dentry                   *dentry;
 210         struct inode                    *inode;
 211 };
 212
 213 static inline void get_ep (struct ep_data *data)
 214 {
 215         atomic_inc (&data->count);
 216 }
 217
 218 static void put_ep (struct ep_data *data)
 219 {
 220         if (likely (!atomic_dec_and_test (&data->count)))
 221                 return;
 222         put_dev (data->dev);
 223         /* needs no more cleanup */
 224         BUG_ON (!list_empty (&data->epfiles));
 225         BUG_ON (waitqueue_active (&data->wait));
 226         kfree (data);
 227 }
 228
 229 /*----------------------------------------------------------------------*/
 230
 231 /* most "how to use the hardware" policy choices are in userspace:
 232  * mapping endpoint roles (which the driver needs) to the capabilities
 233  * which the usb controller has.  most of those capabilities are exposed
 234  * implicitly, starting with the driver name and then endpoint names.
 235  */
 236
 237 static const char *CHIP;
 238
 239 /*----------------------------------------------------------------------*/
 240
 241 /* NOTE:  don't use dev_printk calls before binding to the gadget
 242  * at the end of ep0 configuration, or after unbind.
 243  */
 244
 245 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
 246 #define xprintk(d,level,fmt,args...) \
 247         printk(level "%s: " fmt , shortname , ## args)
 248
 249 #ifdef DEBUG
 250 #define DBG(dev,fmt,args...) \
 251         xprintk(dev , KERN_DEBUG , fmt , ## args)
 252 #else
 253 #define DBG(dev,fmt,args...) \
 254         do { } while (0)
 255 #endif /* DEBUG */
 256
 257 #ifdef VERBOSE_DEBUG
 258 #define VDEBUG  DBG
 259 #else
 260 #define VDEBUG(dev,fmt,args...) \
 261         do { } while (0)
 262 #endif /* DEBUG */
 263
 264 #define ERROR(dev,fmt,args...) \
 265         xprintk(dev , KERN_ERR , fmt , ## args)
 266 #define INFO(dev,fmt,args...) \
 267         xprintk(dev , KERN_INFO , fmt , ## args)
 268
 269
 270 /*----------------------------------------------------------------------*/
 271
 272 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 273  *
 274  * After opening, configure non-control endpoints.  Then use normal
 275  * stream read() and write() requests; and maybe ioctl() to get more
 276  * precise FIFO status when recovering from cancellation.
 277  */
 278
 279 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 280 {
 281         struct ep_data  *epdata = ep->driver_data;
 282
 283         if (!req->context)
 284                 return;
 285         if (req->status)
 286                 epdata->status = req->status;
 287         else
 288                 epdata->status = req->actual;
 289         complete ((struct completion *)req->context);
 290 }
 291
 292 /* tasklock endpoint, returning when it's connected.
 293  * still need dev->lock to use epdata->ep.
 294  */
 295 static int
 296 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
 297 {
 298         int     val;
 299
 300         if (f_flags & O_NONBLOCK) {
 301                 if (down_trylock (&epdata->lock) != 0)
 302                         goto nonblock;
 303                 if (epdata->state != STATE_EP_ENABLED) {
 304                         up (&epdata->lock);
 305 nonblock:
 306                         val = -EAGAIN;
 307                 } else
 308                         val = 0;
 309                 return val;
 310         }
 311
 312         if ((val = down_interruptible (&epdata->lock)) < 0)
 313                 return val;
 314
 315         switch (epdata->state) {
 316         case STATE_EP_ENABLED:
 317                 break;
 318         // case STATE_EP_DISABLED:              /* "can't happen" */
 319         // case STATE_EP_READY:                 /* "can't happen" */
 320         default:                                /* error! */
 321                 pr_debug ("%s: ep %p not available, state %d\n",
 322                                 shortname, epdata, epdata->state);
 323                 // FALLTHROUGH
 324         case STATE_EP_UNBOUND:                  /* clean disconnect */
 325                 val = -ENODEV;
 326                 up (&epdata->lock);
 327         }
 328         return val;
 329 }
 330
 331 static ssize_t
 332 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 333 {
 334         DECLARE_COMPLETION_ONSTACK (done);
 335         int value;
 336
 337         spin_lock_irq (&epdata->dev->lock);
 338         if (likely (epdata->ep != NULL)) {
 339                 struct usb_request      *req = epdata->req;
 340
 341                 req->context = &done;
 342                 req->complete = epio_complete;
 343                 req->buf = buf;
 344                 req->length = len;
 345                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 346         } else
 347                 value = -ENODEV;
 348         spin_unlock_irq (&epdata->dev->lock);
 349
 350         if (likely (value == 0)) {
 351                 value = wait_event_interruptible (done.wait, done.done);
 352                 if (value != 0) {
 353                         spin_lock_irq (&epdata->dev->lock);
 354                         if (likely (epdata->ep != NULL)) {
 355                                 DBG (epdata->dev, "%s i/o interrupted\n",
 356                                                 epdata->name);
 357                                 usb_ep_dequeue (epdata->ep, epdata->req);
 358                                 spin_unlock_irq (&epdata->dev->lock);
 359
 360                                 wait_event (done.wait, done.done);
 361                                 if (epdata->status == -ECONNRESET)
 362                                         epdata->status = -EINTR;
 363                         } else {
 364                                 spin_unlock_irq (&epdata->dev->lock);
 365
 366                                 DBG (epdata->dev, "endpoint gone\n");
 367                                 epdata->status = -ENODEV;
 368                         }
 369                 }
 370                 return epdata->status;
 371         }
 372         return value;
 373 }
 374
 375
 376 /* handle a synchronous OUT bulk/intr/iso transfer */
 377 static ssize_t
 378 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 379 {
 380         struct ep_data          *data = fd->private_data;
 381         void                    *kbuf;
 382         ssize_t                 value;
 383
 384         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 385                 return value;
 386
 387         /* halt any endpoint by doing a "wrong direction" i/o call */
 388         if (usb_endpoint_dir_in(&data->desc)) {
 389                 if (usb_endpoint_xfer_isoc(&data->desc))
 390                         return -EINVAL;
 391                 DBG (data->dev, "%s halt\n", data->name);
 392                 spin_lock_irq (&data->dev->lock);
 393                 if (likely (data->ep != NULL))
 394                         usb_ep_set_halt (data->ep);
 395                 spin_unlock_irq (&data->dev->lock);
 396                 up (&data->lock);
 397                 return -EBADMSG;
 398         }
 399
 400         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
 401
 402         value = -ENOMEM;
 403         kbuf = kmalloc (len, GFP_KERNEL);
 404         if (unlikely (!kbuf))
 405                 goto free1;
 406
 407         value = ep_io (data, kbuf, len);
 408         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
 409                 data->name, len, (int) value);
 410         if (value >= 0 && copy_to_user (buf, kbuf, value))
 411                 value = -EFAULT;
 412
 413 free1:
 414         up (&data->lock);
 415         kfree (kbuf);
 416         return value;
 417 }
 418
 419 /* handle a synchronous IN bulk/intr/iso transfer */
 420 static ssize_t
 421 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 422 {
 423         struct ep_data          *data = fd->private_data;
 424         void                    *kbuf;
 425         ssize_t                 value;
 426
 427         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 428                 return value;
 429
 430         /* halt any endpoint by doing a "wrong direction" i/o call */
 431         if (!usb_endpoint_dir_in(&data->desc)) {
 432                 if (usb_endpoint_xfer_isoc(&data->desc))
 433                         return -EINVAL;
 434                 DBG (data->dev, "%s halt\n", data->name);
 435                 spin_lock_irq (&data->dev->lock);
 436                 if (likely (data->ep != NULL))
 437                         usb_ep_set_halt (data->ep);
 438                 spin_unlock_irq (&data->dev->lock);
 439                 up (&data->lock);
 440                 return -EBADMSG;
 441         }
 442
 443         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
 444
 445         value = -ENOMEM;
 446         kbuf = kmalloc (len, GFP_KERNEL);
 447         if (!kbuf)
 448                 goto free1;
 449         if (copy_from_user (kbuf, buf, len)) {
 450                 value = -EFAULT;
 451                 goto free1;
 452         }
 453
 454         value = ep_io (data, kbuf, len);
 455         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
 456                 data->name, len, (int) value);
 457 free1:
 458         up (&data->lock);
 459         kfree (kbuf);
 460         return value;
 461 }
 462
 463 static int
 464 ep_release (struct inode *inode, struct file *fd)
 465 {
 466         struct ep_data          *data = fd->private_data;
 467         int value;
 468
 469         if ((value = down_interruptible(&data->lock)) < 0)
 470                 return value;
 471
 472         /* clean up if this can be reopened */
 473         if (data->state != STATE_EP_UNBOUND) {
 474                 data->state = STATE_EP_DISABLED;
 475                 data->desc.bDescriptorType = 0;
 476                 data->hs_desc.bDescriptorType = 0;
 477                 usb_ep_disable(data->ep);
 478         }
 479         up (&data->lock);
 480         put_ep (data);
 481         return 0;
 482 }
 483
 484 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
 485 {
 486         struct ep_data          *data = fd->private_data;
 487         int                     status;
 488
 489         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 490                 return status;
 491
 492         spin_lock_irq (&data->dev->lock);
 493         if (likely (data->ep != NULL)) {
 494                 switch (code) {
 495                 case GADGETFS_FIFO_STATUS:
 496                         status = usb_ep_fifo_status (data->ep);
 497                         break;
 498                 case GADGETFS_FIFO_FLUSH:
 499                         usb_ep_fifo_flush (data->ep);
 500                         break;
 501                 case GADGETFS_CLEAR_HALT:
 502                         status = usb_ep_clear_halt (data->ep);
 503                         break;
 504                 default:
 505                         status = -ENOTTY;
 506                 }
 507         } else
 508                 status = -ENODEV;
 509         spin_unlock_irq (&data->dev->lock);
 510         up (&data->lock);
 511         return status;
 512 }
 513
 514 /*----------------------------------------------------------------------*/
 515
 516 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 517
 518 struct kiocb_priv {
 519         struct usb_request      *req;
 520         struct ep_data          *epdata;
 521         void                    *buf;
 522         const struct iovec      *iv;
 523         unsigned long           nr_segs;
 524         unsigned                actual;
 525 };
 526
 527 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
 528 {
 529         struct kiocb_priv       *priv = iocb->private;
 530         struct ep_data          *epdata;
 531         int                     value;
 532
 533         local_irq_disable();
 534         epdata = priv->epdata;
 535         // spin_lock(&epdata->dev->lock);
 536         kiocbSetCancelled(iocb);
 537         if (likely(epdata && epdata->ep && priv->req))
 538                 value = usb_ep_dequeue (epdata->ep, priv->req);
 539         else
 540                 value = -EINVAL;
 541         // spin_unlock(&epdata->dev->lock);
 542         local_irq_enable();
 543
 544         aio_put_req(iocb);
 545         return value;
 546 }
 547
 548 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
 549 {
 550         struct kiocb_priv       *priv = iocb->private;
 551         ssize_t                 len, total;
 552         void                    *to_copy;
 553         int                     i;
 554
 555         /* we "retry" to get the right mm context for this: */
 556
 557         /* copy stuff into user buffers */
 558         total = priv->actual;
 559         len = 0;
 560         to_copy = priv->buf;
 561         for (i=0; i < priv->nr_segs; i++) {
 562                 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
 563
 564                 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
 565                         if (len == 0)
 566                                 len = -EFAULT;
 567                         break;
 568                 }
 569
 570                 total -= this;
 571                 len += this;
 572                 to_copy += this;
 573                 if (total == 0)
 574                         break;
 575         }
 576         kfree(priv->buf);
 577         kfree(priv);
 578         return len;
 579 }
 580
 581 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 582 {
 583         struct kiocb            *iocb = req->context;
 584         struct kiocb_priv       *priv = iocb->private;
 585         struct ep_data          *epdata = priv->epdata;
 586
 587         /* lock against disconnect (and ideally, cancel) */
 588         spin_lock(&epdata->dev->lock);
 589         priv->req = NULL;
 590         priv->epdata = NULL;
 591
 592         /* if this was a write or a read returning no data then we
 593          * don't need to copy anything to userspace, so we can
 594          * complete the aio request immediately.
 595          */
 596         if (priv->iv == NULL || unlikely(req->actual == 0)) {
 597                 kfree(req->buf);
 598                 kfree(priv);
 599                 iocb->private = NULL;
 600                 /* aio_complete() reports bytes-transferred _and_ faults */
 601                 aio_complete(iocb, req->actual ? req->actual : req->status,
 602                                 req->status);
 603         } else {
 604                 /* retry() won't report both; so we hide some faults */
 605                 if (unlikely(0 != req->status))
 606                         DBG(epdata->dev, "%s fault %d len %d\n",
 607                                 ep->name, req->status, req->actual);
 608
 609                 priv->buf = req->buf;
 610                 priv->actual = req->actual;
 611                 kick_iocb(iocb);
 612         }
 613         spin_unlock(&epdata->dev->lock);
 614
 615         usb_ep_free_request(ep, req);
 616         put_ep(epdata);
 617 }
 618
 619 static ssize_t
 620 ep_aio_rwtail(
 621         struct kiocb    *iocb,
 622         char            *buf,
 623         size_t          len,
 624         struct ep_data  *epdata,
 625         const struct iovec *iv,
 626         unsigned long   nr_segs
 627 )
 628 {
 629         struct kiocb_priv       *priv;
 630         struct usb_request      *req;
 631         ssize_t                 value;
 632
 633         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 634         if (!priv) {
 635                 value = -ENOMEM;
 636 fail:
 637                 kfree(buf);
 638                 return value;
 639         }
 640         iocb->private = priv;
 641         priv->iv = iv;
 642         priv->nr_segs = nr_segs;
 643
 644         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 645         if (unlikely(value < 0)) {
 646                 kfree(priv);
 647                 goto fail;
 648         }
 649
 650         iocb->ki_cancel = ep_aio_cancel;
 651         get_ep(epdata);
 652         priv->epdata = epdata;
 653         priv->actual = 0;
 654
 655         /* each kiocb is coupled to one usb_request, but we can't
 656          * allocate or submit those if the host disconnected.
 657          */
 658         spin_lock_irq(&epdata->dev->lock);
 659         if (likely(epdata->ep)) {
 660                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 661                 if (likely(req)) {
 662                         priv->req = req;
 663                         req->buf = buf;
 664                         req->length = len;
 665                         req->complete = ep_aio_complete;
 666                         req->context = iocb;
 667                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 668                         if (unlikely(0 != value))
 669                                 usb_ep_free_request(epdata->ep, req);
 670                 } else
 671                         value = -EAGAIN;
 672         } else
 673                 value = -ENODEV;
 674         spin_unlock_irq(&epdata->dev->lock);
 675
 676         up(&epdata->lock);
 677
 678         if (unlikely(value)) {
 679                 kfree(priv);
 680                 put_ep(epdata);
 681         } else
 682                 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
 683         return value;
 684 }
 685
 686 static ssize_t
 687 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
 688                 unsigned long nr_segs, loff_t o)
 689 {
 690         struct ep_data          *epdata = iocb->ki_filp->private_data;
 691         char                    *buf;
 692
 693         if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
 694                 return -EINVAL;
 695
 696         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 697         if (unlikely(!buf))
 698                 return -ENOMEM;
 699
 700         iocb->ki_retry = ep_aio_read_retry;
 701         return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
 702 }
 703
 704 static ssize_t
 705 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
 706                 unsigned long nr_segs, loff_t o)
 707 {
 708         struct ep_data          *epdata = iocb->ki_filp->private_data;
 709         char                    *buf;
 710         size_t                  len = 0;
 711         int                     i = 0;
 712
 713         if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
 714                 return -EINVAL;
 715
 716         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 717         if (unlikely(!buf))
 718                 return -ENOMEM;
 719
 720         for (i=0; i < nr_segs; i++) {
 721                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
 722                                 iov[i].iov_len) != 0)) {
 723                         kfree(buf);
 724                         return -EFAULT;
 725                 }
 726                 len += iov[i].iov_len;
 727         }
 728         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
 729 }
 730
 731 /*----------------------------------------------------------------------*/
 732
 733 /* used after endpoint configuration */
 734 static const struct file_operations ep_io_operations = {
 735         .owner =        THIS_MODULE,
 736         .llseek =       no_llseek,
 737
 738         .read =         ep_read,
 739         .write =        ep_write,
 740         .unlocked_ioctl = ep_ioctl,
 741         .release =      ep_release,
 742
 743         .aio_read =     ep_aio_read,
 744         .aio_write =    ep_aio_write,
 745 };
 746
 747 /* ENDPOINT INITIALIZATION
 748  *
 749  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 750  *     status = write (fd, descriptors, sizeof descriptors)
 751  *
 752  * That write establishes the endpoint configuration, configuring
 753  * the controller to process bulk, interrupt, or isochronous transfers
 754  * at the right maxpacket size, and so on.
 755  *
 756  * The descriptors are message type 1, identified by a host order u32
 757  * at the beginning of what's written.  Descriptor order is: full/low
 758  * speed descriptor, then optional high speed descriptor.
 759  */
 760 static ssize_t
 761 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 762 {
 763         struct ep_data          *data = fd->private_data;
 764         struct usb_ep           *ep;
 765         u32                     tag;
 766         int                     value, length = len;
 767
 768         if ((value = down_interruptible (&data->lock)) < 0)
 769                 return value;
 770
 771         if (data->state != STATE_EP_READY) {
 772                 value = -EL2HLT;
 773                 goto fail;
 774         }
 775
 776         value = len;
 777         if (len < USB_DT_ENDPOINT_SIZE + 4)
 778                 goto fail0;
 779
 780         /* we might need to change message format someday */
 781         if (copy_from_user (&tag, buf, 4)) {
 782                 goto fail1;
 783         }
 784         if (tag != 1) {
 785                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 786                 goto fail0;
 787         }
 788         buf += 4;
 789         len -= 4;
 790
 791         /* NOTE:  audio endpoint extensions not accepted here;
 792          * just don't include the extra bytes.
 793          */
 794
 795         /* full/low speed descriptor, then high speed */
 796         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 797                 goto fail1;
 798         }
 799         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 800                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 801                 goto fail0;
 802         if (len != USB_DT_ENDPOINT_SIZE) {
 803                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 804                         goto fail0;
 805                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 806                                         USB_DT_ENDPOINT_SIZE)) {
 807                         goto fail1;
 808                 }
 809                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 810                                 || data->hs_desc.bDescriptorType
 811                                         != USB_DT_ENDPOINT) {
 812                         DBG(data->dev, "config %s, bad hs length or type\n",
 813                                         data->name);
 814                         goto fail0;
 815                 }
 816         }
 817
 818         spin_lock_irq (&data->dev->lock);
 819         if (data->dev->state == STATE_DEV_UNBOUND) {
 820                 value = -ENOENT;
 821                 goto gone;
 822         } else if ((ep = data->ep) == NULL) {
 823                 value = -ENODEV;
 824                 goto gone;
 825         }
 826         switch (data->dev->gadget->speed) {
 827         case USB_SPEED_LOW:
 828         case USB_SPEED_FULL:
 829                 value = usb_ep_enable (ep, &data->desc);
 830                 if (value == 0)
 831                         data->state = STATE_EP_ENABLED;
 832                 break;
 833 #ifdef  CONFIG_USB_GADGET_DUALSPEED
 834         case USB_SPEED_HIGH:
 835                 /* fails if caller didn't provide that descriptor... */
 836                 value = usb_ep_enable (ep, &data->hs_desc);
 837                 if (value == 0)
 838                         data->state = STATE_EP_ENABLED;
 839                 break;
 840 #endif
 841         default:
 842                 DBG(data->dev, "unconnected, %s init abandoned\n",
 843                                 data->name);
 844                 value = -EINVAL;
 845         }
 846         if (value == 0) {
 847                 fd->f_op = &ep_io_operations;
 848                 value = length;
 849         }
 850 gone:
 851         spin_unlock_irq (&data->dev->lock);
 852         if (value < 0) {
 853 fail:
 854                 data->desc.bDescriptorType = 0;
 855                 data->hs_desc.bDescriptorType = 0;
 856         }
 857         up (&data->lock);
 858         return value;
 859 fail0:
 860         value = -EINVAL;
 861         goto fail;
 862 fail1:
 863         value = -EFAULT;
 864         goto fail;
 865 }
 866
 867 static int
 868 ep_open (struct inode *inode, struct file *fd)
 869 {
 870         struct ep_data          *data = inode->i_private;
 871         int                     value = -EBUSY;
 872
 873         if (down_interruptible (&data->lock) != 0)
 874                 return -EINTR;
 875         spin_lock_irq (&data->dev->lock);
 876         if (data->dev->state == STATE_DEV_UNBOUND)
 877                 value = -ENOENT;
 878         else if (data->state == STATE_EP_DISABLED) {
 879                 value = 0;
 880                 data->state = STATE_EP_READY;
 881                 get_ep (data);
 882                 fd->private_data = data;
 883                 VDEBUG (data->dev, "%s ready\n", data->name);
 884         } else
 885                 DBG (data->dev, "%s state %d\n",
 886                         data->name, data->state);
 887         spin_unlock_irq (&data->dev->lock);
 888         up (&data->lock);
 889         return value;
 890 }
 891
 892 /* used before endpoint configuration */
 893 static const struct file_operations ep_config_operations = {
 894         .owner =        THIS_MODULE,
 895         .llseek =       no_llseek,
 896
 897         .open =         ep_open,
 898         .write =        ep_config,
 899         .release =      ep_release,
 900 };
 901
 902 /*----------------------------------------------------------------------*/
 903
 904 /* EP0 IMPLEMENTATION can be partly in userspace.
 905  *
 906  * Drivers that use this facility receive various events, including
 907  * control requests the kernel doesn't handle.  Drivers that don't
 908  * use this facility may be too simple-minded for real applications.
 909  */
 910
 911 static inline void ep0_readable (struct dev_data *dev)
 912 {
 913         wake_up (&dev->wait);
 914         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 915 }
 916
 917 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 918 {
 919         struct dev_data         *dev = ep->driver_data;
 920
 921         if (req->buf != dev->rbuf) {
 922                 kfree(req->buf);
 923                 req->buf = dev->rbuf;
 924                 req->dma = DMA_ADDR_INVALID;
 925         }
 926         req->complete = epio_complete;
 927         dev->setup_out_ready = 0;
 928 }
 929
 930 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 931 {
 932         struct dev_data         *dev = ep->driver_data;
 933         unsigned long           flags;
 934         int                     free = 1;
 935
 936         /* for control OUT, data must still get to userspace */
 937         spin_lock_irqsave(&dev->lock, flags);
 938         if (!dev->setup_in) {
 939                 dev->setup_out_error = (req->status != 0);
 940                 if (!dev->setup_out_error)
 941                         free = 0;
 942                 dev->setup_out_ready = 1;
 943                 ep0_readable (dev);
 944         }
 945
 946         /* clean up as appropriate */
 947         if (free && req->buf != &dev->rbuf)
 948                 clean_req (ep, req);
 949         req->complete = epio_complete;
 950         spin_unlock_irqrestore(&dev->lock, flags);
 951 }
 952
 953 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 954 {
 955         struct dev_data *dev = ep->driver_data;
 956
 957         if (dev->setup_out_ready) {
 958                 DBG (dev, "ep0 request busy!\n");
 959                 return -EBUSY;
 960         }
 961         if (len > sizeof (dev->rbuf))
 962                 req->buf = kmalloc(len, GFP_ATOMIC);
 963         if (req->buf == NULL) {
 964                 req->buf = dev->rbuf;
 965                 return -ENOMEM;
 966         }
 967         req->complete = ep0_complete;
 968         req->length = len;
 969         req->zero = 0;
 970         return 0;
 971 }
 972
 973 static ssize_t
 974 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 975 {
 976         struct dev_data                 *dev = fd->private_data;
 977         ssize_t                         retval;
 978         enum ep0_state                  state;
 979
 980         spin_lock_irq (&dev->lock);
 981
 982         /* report fd mode change before acting on it */
 983         if (dev->setup_abort) {
 984                 dev->setup_abort = 0;
 985                 retval = -EIDRM;
 986                 goto done;
 987         }
 988
 989         /* control DATA stage */
 990         if ((state = dev->state) == STATE_DEV_SETUP) {
 991
 992                 if (dev->setup_in) {            /* stall IN */
 993                         VDEBUG(dev, "ep0in stall\n");
 994                         (void) usb_ep_set_halt (dev->gadget->ep0);
 995                         retval = -EL2HLT;
 996                         dev->state = STATE_DEV_CONNECTED;
 997
 998                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
 999                         struct usb_ep           *ep = dev->gadget->ep0;
1000                         struct usb_request      *req = dev->req;
1001
1002                         if ((retval = setup_req (ep, req, 0)) == 0)
1003                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1004                         dev->state = STATE_DEV_CONNECTED;
1005
1006                         /* assume that was SET_CONFIGURATION */
1007                         if (dev->current_config) {
1008                                 unsigned power;
1009
1010                                 if (gadget_is_dualspeed(dev->gadget)
1011                                                 && (dev->gadget->speed
1012                                                         == USB_SPEED_HIGH))
1013                                         power = dev->hs_config->bMaxPower;
1014                                 else
1015                                         power = dev->config->bMaxPower;
1016                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1017                         }
1018
1019                 } else {                        /* collect OUT data */
1020                         if ((fd->f_flags & O_NONBLOCK) != 0
1021                                         && !dev->setup_out_ready) {
1022                                 retval = -EAGAIN;
1023                                 goto done;
1024                         }
1025                         spin_unlock_irq (&dev->lock);
1026                         retval = wait_event_interruptible (dev->wait,
1027                                         dev->setup_out_ready != 0);
1028
1029                         /* FIXME state could change from under us */
1030                         spin_lock_irq (&dev->lock);
1031                         if (retval)
1032                                 goto done;
1033
1034                         if (dev->state != STATE_DEV_SETUP) {
1035                                 retval = -ECANCELED;
1036                                 goto done;
1037                         }
1038                         dev->state = STATE_DEV_CONNECTED;
1039
1040                         if (dev->setup_out_error)
1041                                 retval = -EIO;
1042                         else {
1043                                 len = min (len, (size_t)dev->req->actual);
1044 // FIXME don't call this with the spinlock held ...
1045                                 if (copy_to_user (buf, dev->req->buf, len))
1046                                         retval = -EFAULT;
1047                                 clean_req (dev->gadget->ep0, dev->req);
1048                                 /* NOTE userspace can't yet choose to stall */
1049                         }
1050                 }
1051                 goto done;
1052         }
1053
1054         /* else normal: return event data */
1055         if (len < sizeof dev->event [0]) {
1056                 retval = -EINVAL;
1057                 goto done;
1058         }
1059         len -= len % sizeof (struct usb_gadgetfs_event);
1060         dev->usermode_setup = 1;
1061
1062 scan:
1063         /* return queued events right away */
1064         if (dev->ev_next != 0) {
1065                 unsigned                i, n;
1066
1067                 n = len / sizeof (struct usb_gadgetfs_event);
1068                 if (dev->ev_next < n)
1069                         n = dev->ev_next;
1070
1071                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1072                 for (i = 0; i < n; i++) {
1073                         if (dev->event [i].type == GADGETFS_SETUP) {
1074                                 dev->state = STATE_DEV_SETUP;
1075                                 n = i + 1;
1076                                 break;
1077                         }
1078                 }
1079                 spin_unlock_irq (&dev->lock);
1080                 len = n * sizeof (struct usb_gadgetfs_event);
1081                 if (copy_to_user (buf, &dev->event, len))
1082                         retval = -EFAULT;
1083                 else
1084                         retval = len;
1085                 if (len > 0) {
1086                         /* NOTE this doesn't guard against broken drivers;
1087                          * concurrent ep0 readers may lose events.
1088                          */
1089                         spin_lock_irq (&dev->lock);
1090                         if (dev->ev_next > n) {
1091                                 memmove(&dev->event[0], &dev->event[n],
1092                                         sizeof (struct usb_gadgetfs_event)
1093                                                 * (dev->ev_next - n));
1094                         }
1095                         dev->ev_next -= n;
1096                         spin_unlock_irq (&dev->lock);
1097                 }
1098                 return retval;
1099         }
1100         if (fd->f_flags & O_NONBLOCK) {
1101                 retval = -EAGAIN;
1102                 goto done;
1103         }
1104
1105         switch (state) {
1106         default:
1107                 DBG (dev, "fail %s, state %d\n", __func__, state);
1108                 retval = -ESRCH;
1109                 break;
1110         case STATE_DEV_UNCONNECTED:
1111         case STATE_DEV_CONNECTED:
1112                 spin_unlock_irq (&dev->lock);
1113                 DBG (dev, "%s wait\n", __func__);
1114
1115                 /* wait for events */
1116                 retval = wait_event_interruptible (dev->wait,
1117                                 dev->ev_next != 0);
1118                 if (retval < 0)
1119                         return retval;
1120                 spin_lock_irq (&dev->lock);
1121                 goto scan;
1122         }
1123
1124 done:
1125         spin_unlock_irq (&dev->lock);
1126         return retval;
1127 }
1128
1129 static struct usb_gadgetfs_event *
1130 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1131 {
1132         struct usb_gadgetfs_event       *event;
1133         unsigned                        i;
1134
1135         switch (type) {
1136         /* these events purge the queue */
1137         case GADGETFS_DISCONNECT:
1138                 if (dev->state == STATE_DEV_SETUP)
1139                         dev->setup_abort = 1;
1140                 // FALL THROUGH
1141         case GADGETFS_CONNECT:
1142                 dev->ev_next = 0;
1143                 break;
1144         case GADGETFS_SETUP:            /* previous request timed out */
1145         case GADGETFS_SUSPEND:          /* same effect */
1146                 /* these events can't be repeated */
1147                 for (i = 0; i != dev->ev_next; i++) {
1148                         if (dev->event [i].type != type)
1149                                 continue;
1150                         DBG(dev, "discard old event[%d] %d\n", i, type);
1151                         dev->ev_next--;
1152                         if (i == dev->ev_next)
1153                                 break;
1154                         /* indices start at zero, for simplicity */
1155                         memmove (&dev->event [i], &dev->event [i + 1],
1156                                 sizeof (struct usb_gadgetfs_event)
1157                                         * (dev->ev_next - i));
1158                 }
1159                 break;
1160         default:
1161                 BUG ();
1162         }
1163         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1164         event = &dev->event [dev->ev_next++];
1165         BUG_ON (dev->ev_next > N_EVENT);
1166         memset (event, 0, sizeof *event);
1167         event->type = type;
1168         return event;
1169 }
1170
1171 static ssize_t
1172 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1173 {
1174         struct dev_data         *dev = fd->private_data;
1175         ssize_t                 retval = -ESRCH;
1176
1177         spin_lock_irq (&dev->lock);
1178
1179         /* report fd mode change before acting on it */
1180         if (dev->setup_abort) {
1181                 dev->setup_abort = 0;
1182                 retval = -EIDRM;
1183
1184         /* data and/or status stage for control request */
1185         } else if (dev->state == STATE_DEV_SETUP) {
1186
1187                 /* IN DATA+STATUS caller makes len <= wLength */
1188                 if (dev->setup_in) {
1189                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1190                         if (retval == 0) {
1191                                 dev->state = STATE_DEV_CONNECTED;
1192                                 spin_unlock_irq (&dev->lock);
1193                                 if (copy_from_user (dev->req->buf, buf, len))
1194                                         retval = -EFAULT;
1195                                 else {
1196                                         if (len < dev->setup_wLength)
1197                                                 dev->req->zero = 1;
1198                                         retval = usb_ep_queue (
1199                                                 dev->gadget->ep0, dev->req,
1200                                                 GFP_KERNEL);
1201                                 }
1202                                 if (retval < 0) {
1203                                         spin_lock_irq (&dev->lock);
1204                                         clean_req (dev->gadget->ep0, dev->req);
1205                                         spin_unlock_irq (&dev->lock);
1206                                 } else
1207                                         retval = len;
1208
1209                                 return retval;
1210                         }
1211
1212                 /* can stall some OUT transfers */
1213                 } else if (dev->setup_can_stall) {
1214                         VDEBUG(dev, "ep0out stall\n");
1215                         (void) usb_ep_set_halt (dev->gadget->ep0);
1216                         retval = -EL2HLT;
1217                         dev->state = STATE_DEV_CONNECTED;
1218                 } else {
1219                         DBG(dev, "bogus ep0out stall!\n");
1220                 }
1221         } else
1222                 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1223
1224         spin_unlock_irq (&dev->lock);
1225         return retval;
1226 }
1227
1228 static int
1229 ep0_fasync (int f, struct file *fd, int on)
1230 {
1231         struct dev_data         *dev = fd->private_data;
1232         // caller must F_SETOWN before signal delivery happens
1233         VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1234         return fasync_helper (f, fd, on, &dev->fasync);
1235 }
1236
1237 static struct usb_gadget_driver gadgetfs_driver;
1238
1239 static int
1240 dev_release (struct inode *inode, struct file *fd)
1241 {
1242         struct dev_data         *dev = fd->private_data;
1243
1244         /* closing ep0 === shutdown all */
1245
1246         usb_gadget_unregister_driver (&gadgetfs_driver);
1247
1248         /* at this point "good" hardware has disconnected the
1249          * device from USB; the host won't see it any more.
1250          * alternatively, all host requests will time out.
1251          */
1252
1253         kfree (dev->buf);
1254         dev->buf = NULL;
1255         put_dev (dev);
1256
1257         /* other endpoints were all decoupled from this device */
1258         spin_lock_irq(&dev->lock);
1259         dev->state = STATE_DEV_DISABLED;
1260         spin_unlock_irq(&dev->lock);
1261         return 0;
1262 }
1263
1264 static unsigned int
1265 ep0_poll (struct file *fd, poll_table *wait)
1266 {
1267        struct dev_data         *dev = fd->private_data;
1268        int                     mask = 0;
1269
1270        poll_wait(fd, &dev->wait, wait);
1271
1272        spin_lock_irq (&dev->lock);
1273
1274        /* report fd mode change before acting on it */
1275        if (dev->setup_abort) {
1276                dev->setup_abort = 0;
1277                mask = POLLHUP;
1278                goto out;
1279        }
1280
1281        if (dev->state == STATE_DEV_SETUP) {
1282                if (dev->setup_in || dev->setup_can_stall)
1283                        mask = POLLOUT;
1284        } else {
1285                if (dev->ev_next != 0)
1286                        mask = POLLIN;
1287        }
1288 out:
1289        spin_unlock_irq(&dev->lock);
1290        return mask;
1291 }
1292
1293 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1294 {
1295         struct dev_data         *dev = fd->private_data;
1296         struct usb_gadget       *gadget = dev->gadget;
1297         long ret = -ENOTTY;
1298
1299         if (gadget->ops->ioctl) {
1300                 lock_kernel();
1301                 ret = gadget->ops->ioctl (gadget, code, value);
1302                 unlock_kernel();
1303         }
1304         return ret;
1305 }
1306
1307 /* used after device configuration */
1308 static const struct file_operations ep0_io_operations = {
1309         .owner =        THIS_MODULE,
1310         .llseek =       no_llseek,
1311
1312         .read =         ep0_read,
1313         .write =        ep0_write,
1314         .fasync =       ep0_fasync,
1315         .poll =         ep0_poll,
1316         .unlocked_ioctl =       dev_ioctl,
1317         .release =      dev_release,
1318 };
1319
1320 /*----------------------------------------------------------------------*/
1321
1322 /* The in-kernel gadget driver handles most ep0 issues, in particular
1323  * enumerating the single configuration (as provided from user space).
1324  *
1325  * Unrecognized ep0 requests may be handled in user space.
1326  */
1327
1328 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1329 static void make_qualifier (struct dev_data *dev)
1330 {
1331         struct usb_qualifier_descriptor         qual;
1332         struct usb_device_descriptor            *desc;
1333
1334         qual.bLength = sizeof qual;
1335         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1336         qual.bcdUSB = cpu_to_le16 (0x0200);
1337
1338         desc = dev->dev;
1339         qual.bDeviceClass = desc->bDeviceClass;
1340         qual.bDeviceSubClass = desc->bDeviceSubClass;
1341         qual.bDeviceProtocol = desc->bDeviceProtocol;
1342
1343         /* assumes ep0 uses the same value for both speeds ... */
1344         qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
1345
1346         qual.bNumConfigurations = 1;
1347         qual.bRESERVED = 0;
1348
1349         memcpy (dev->rbuf, &qual, sizeof qual);
1350 }
1351 #endif
1352
1353 static int
1354 config_buf (struct dev_data *dev, u8 type, unsigned index)
1355 {
1356         int             len;
1357         int             hs = 0;
1358
1359         /* only one configuration */
1360         if (index > 0)
1361                 return -EINVAL;
1362
1363         if (gadget_is_dualspeed(dev->gadget)) {
1364                 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1365                 if (type == USB_DT_OTHER_SPEED_CONFIG)
1366                         hs = !hs;
1367         }
1368         if (hs) {
1369                 dev->req->buf = dev->hs_config;
1370                 len = le16_to_cpu(dev->hs_config->wTotalLength);
1371         } else {
1372                 dev->req->buf = dev->config;
1373                 len = le16_to_cpu(dev->config->wTotalLength);
1374         }
1375         ((u8 *)dev->req->buf) [1] = type;
1376         return len;
1377 }
1378
1379 static int
1380 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1381 {
1382         struct dev_data                 *dev = get_gadget_data (gadget);
1383         struct usb_request              *req = dev->req;
1384         int                             value = -EOPNOTSUPP;
1385         struct usb_gadgetfs_event       *event;
1386         u16                             w_value = le16_to_cpu(ctrl->wValue);
1387         u16                             w_length = le16_to_cpu(ctrl->wLength);
1388
1389         spin_lock (&dev->lock);
1390         dev->setup_abort = 0;
1391         if (dev->state == STATE_DEV_UNCONNECTED) {
1392                 if (gadget_is_dualspeed(gadget)
1393                                 && gadget->speed == USB_SPEED_HIGH
1394                                 && dev->hs_config == NULL) {
1395                         spin_unlock(&dev->lock);
1396                         ERROR (dev, "no high speed config??\n");
1397                         return -EINVAL;
1398                 }
1399
1400                 dev->state = STATE_DEV_CONNECTED;
1401                 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1402
1403                 INFO (dev, "connected\n");
1404                 event = next_event (dev, GADGETFS_CONNECT);
1405                 event->u.speed = gadget->speed;
1406                 ep0_readable (dev);
1407
1408         /* host may have given up waiting for response.  we can miss control
1409          * requests handled lower down (device/endpoint status and features);
1410          * then ep0_{read,write} will report the wrong status. controller
1411          * driver will have aborted pending i/o.
1412          */
1413         } else if (dev->state == STATE_DEV_SETUP)
1414                 dev->setup_abort = 1;
1415
1416         req->buf = dev->rbuf;
1417         req->dma = DMA_ADDR_INVALID;
1418         req->context = NULL;
1419         value = -EOPNOTSUPP;
1420         switch (ctrl->bRequest) {
1421
1422         case USB_REQ_GET_DESCRIPTOR:
1423                 if (ctrl->bRequestType != USB_DIR_IN)
1424                         goto unrecognized;
1425                 switch (w_value >> 8) {
1426
1427                 case USB_DT_DEVICE:
1428                         value = min (w_length, (u16) sizeof *dev->dev);
1429                         req->buf = dev->dev;
1430                         break;
1431 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1432                 case USB_DT_DEVICE_QUALIFIER:
1433                         if (!dev->hs_config)
1434                                 break;
1435                         value = min (w_length, (u16)
1436                                 sizeof (struct usb_qualifier_descriptor));
1437                         make_qualifier (dev);
1438                         break;
1439                 case USB_DT_OTHER_SPEED_CONFIG:
1440                         // FALLTHROUGH
1441 #endif
1442                 case USB_DT_CONFIG:
1443                         value = config_buf (dev,
1444                                         w_value >> 8,
1445                                         w_value & 0xff);
1446                         if (value >= 0)
1447                                 value = min (w_length, (u16) value);
1448                         break;
1449                 case USB_DT_STRING:
1450                         goto unrecognized;
1451
1452                 default:                // all others are errors
1453                         break;
1454                 }
1455                 break;
1456
1457         /* currently one config, two speeds */
1458         case USB_REQ_SET_CONFIGURATION:
1459                 if (ctrl->bRequestType != 0)
1460                         goto unrecognized;
1461                 if (0 == (u8) w_value) {
1462                         value = 0;
1463                         dev->current_config = 0;
1464                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1465                         // user mode expected to disable endpoints
1466                 } else {
1467                         u8      config, power;
1468
1469                         if (gadget_is_dualspeed(gadget)
1470                                         && gadget->speed == USB_SPEED_HIGH) {
1471                                 config = dev->hs_config->bConfigurationValue;
1472                                 power = dev->hs_config->bMaxPower;
1473                         } else {
1474                                 config = dev->config->bConfigurationValue;
1475                                 power = dev->config->bMaxPower;
1476                         }
1477
1478                         if (config == (u8) w_value) {
1479                                 value = 0;
1480                                 dev->current_config = config;
1481                                 usb_gadget_vbus_draw(gadget, 2 * power);
1482                         }
1483                 }
1484
1485                 /* report SET_CONFIGURATION like any other control request,
1486                  * except that usermode may not stall this.  the next
1487                  * request mustn't be allowed start until this finishes:
1488                  * endpoints and threads set up, etc.
1489                  *
1490                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1491                  * has bad/racey automagic that prevents synchronizing here.
1492                  * even kernel mode drivers often miss them.
1493                  */
1494                 if (value == 0) {
1495                         INFO (dev, "configuration #%d\n", dev->current_config);
1496                         if (dev->usermode_setup) {
1497                                 dev->setup_can_stall = 0;
1498                                 goto delegate;
1499                         }
1500                 }
1501                 break;
1502
1503 #ifndef CONFIG_USB_GADGET_PXA25X
1504         /* PXA automagically handles this request too */
1505         case USB_REQ_GET_CONFIGURATION:
1506                 if (ctrl->bRequestType != 0x80)
1507                         goto unrecognized;
1508                 *(u8 *)req->buf = dev->current_config;
1509                 value = min (w_length, (u16) 1);
1510                 break;
1511 #endif
1512
1513         default:
1514 unrecognized:
1515                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1516                         dev->usermode_setup ? "delegate" : "fail",
1517                         ctrl->bRequestType, ctrl->bRequest,
1518                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1519
1520                 /* if there's an ep0 reader, don't stall */
1521                 if (dev->usermode_setup) {
1522                         dev->setup_can_stall = 1;
1523 delegate:
1524                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1525                                                 ? 1 : 0;
1526                         dev->setup_wLength = w_length;
1527                         dev->setup_out_ready = 0;
1528                         dev->setup_out_error = 0;
1529                         value = 0;
1530
1531                         /* read DATA stage for OUT right away */
1532                         if (unlikely (!dev->setup_in && w_length)) {
1533                                 value = setup_req (gadget->ep0, dev->req,
1534                                                         w_length);
1535                                 if (value < 0)
1536                                         break;
1537                                 value = usb_ep_queue (gadget->ep0, dev->req,
1538                                                         GFP_ATOMIC);
1539                                 if (value < 0) {
1540                                         clean_req (gadget->ep0, dev->req);
1541                                         break;
1542                                 }
1543
1544                                 /* we can't currently stall these */
1545                                 dev->setup_can_stall = 0;
1546                         }
1547
1548                         /* state changes when reader collects event */
1549                         event = next_event (dev, GADGETFS_SETUP);
1550                         event->u.setup = *ctrl;
1551                         ep0_readable (dev);
1552                         spin_unlock (&dev->lock);
1553                         return 0;
1554                 }
1555         }
1556
1557         /* proceed with data transfer and status phases? */
1558         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1559                 req->length = value;
1560                 req->zero = value < w_length;
1561                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1562                 if (value < 0) {
1563                         DBG (dev, "ep_queue --> %d\n", value);
1564                         req->status = 0;
1565                 }
1566         }
1567
1568         /* device stalls when value < 0 */
1569         spin_unlock (&dev->lock);
1570         return value;
1571 }
1572
1573 static void destroy_ep_files (struct dev_data *dev)
1574 {
1575         struct list_head        *entry, *tmp;
1576
1577         DBG (dev, "%s %d\n", __func__, dev->state);
1578
1579         /* dev->state must prevent interference */
1580 restart:
1581         spin_lock_irq (&dev->lock);
1582         list_for_each_safe (entry, tmp, &dev->epfiles) {
1583                 struct ep_data  *ep;
1584                 struct inode    *parent;
1585                 struct dentry   *dentry;
1586
1587                 /* break link to FS */
1588                 ep = list_entry (entry, struct ep_data, epfiles);
1589                 list_del_init (&ep->epfiles);
1590                 dentry = ep->dentry;
1591                 ep->dentry = NULL;
1592                 parent = dentry->d_parent->d_inode;
1593
1594                 /* break link to controller */
1595                 if (ep->state == STATE_EP_ENABLED)
1596                         (void) usb_ep_disable (ep->ep);
1597                 ep->state = STATE_EP_UNBOUND;
1598                 usb_ep_free_request (ep->ep, ep->req);
1599                 ep->ep = NULL;
1600                 wake_up (&ep->wait);
1601                 put_ep (ep);
1602
1603                 spin_unlock_irq (&dev->lock);
1604
1605                 /* break link to dcache */
1606                 mutex_lock (&parent->i_mutex);
1607                 d_delete (dentry);
1608                 dput (dentry);
1609                 mutex_unlock (&parent->i_mutex);
1610
1611                 /* fds may still be open */
1612                 goto restart;
1613         }
1614         spin_unlock_irq (&dev->lock);
1615 }
1616
1617
1618 static struct inode *
1619 gadgetfs_create_file (struct super_block *sb, char const *name,
1620                 void *data, const struct file_operations *fops,
1621                 struct dentry **dentry_p);
1622
1623 static int activate_ep_files (struct dev_data *dev)
1624 {
1625         struct usb_ep   *ep;
1626         struct ep_data  *data;
1627
1628         gadget_for_each_ep (ep, dev->gadget) {
1629
1630                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1631                 if (!data)
1632                         goto enomem0;
1633                 data->state = STATE_EP_DISABLED;
1634                 init_MUTEX (&data->lock);
1635                 init_waitqueue_head (&data->wait);
1636
1637                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1638                 atomic_set (&data->count, 1);
1639                 data->dev = dev;
1640                 get_dev (dev);
1641
1642                 data->ep = ep;
1643                 ep->driver_data = data;
1644
1645                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1646                 if (!data->req)
1647                         goto enomem1;
1648
1649                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1650                                 data, &ep_config_operations,
1651                                 &data->dentry);
1652                 if (!data->inode)
1653                         goto enomem2;
1654                 list_add_tail (&data->epfiles, &dev->epfiles);
1655         }
1656         return 0;
1657
1658 enomem2:
1659         usb_ep_free_request (ep, data->req);
1660 enomem1:
1661         put_dev (dev);
1662         kfree (data);
1663 enomem0:
1664         DBG (dev, "%s enomem\n", __func__);
1665         destroy_ep_files (dev);
1666         return -ENOMEM;
1667 }
1668
1669 static void
1670 gadgetfs_unbind (struct usb_gadget *gadget)
1671 {
1672         struct dev_data         *dev = get_gadget_data (gadget);
1673
1674         DBG (dev, "%s\n", __func__);
1675
1676         spin_lock_irq (&dev->lock);
1677         dev->state = STATE_DEV_UNBOUND;
1678         spin_unlock_irq (&dev->lock);
1679
1680         destroy_ep_files (dev);
1681         gadget->ep0->driver_data = NULL;
1682         set_gadget_data (gadget, NULL);
1683
1684         /* we've already been disconnected ... no i/o is active */
1685         if (dev->req)
1686                 usb_ep_free_request (gadget->ep0, dev->req);
1687         DBG (dev, "%s done\n", __func__);
1688         put_dev (dev);
1689 }
1690
1691 static struct dev_data          *the_device;
1692
1693 static int
1694 gadgetfs_bind (struct usb_gadget *gadget)
1695 {
1696         struct dev_data         *dev = the_device;
1697
1698         if (!dev)
1699                 return -ESRCH;
1700         if (0 != strcmp (CHIP, gadget->name)) {
1701                 pr_err("%s expected %s controller not %s\n",
1702                         shortname, CHIP, gadget->name);
1703                 return -ENODEV;
1704         }
1705
1706         set_gadget_data (gadget, dev);
1707         dev->gadget = gadget;
1708         gadget->ep0->driver_data = dev;
1709         dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1710
1711         /* preallocate control response and buffer */
1712         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1713         if (!dev->req)
1714                 goto enomem;
1715         dev->req->context = NULL;
1716         dev->req->complete = epio_complete;
1717
1718         if (activate_ep_files (dev) < 0)
1719                 goto enomem;
1720
1721         INFO (dev, "bound to %s driver\n", gadget->name);
1722         spin_lock_irq(&dev->lock);
1723         dev->state = STATE_DEV_UNCONNECTED;
1724         spin_unlock_irq(&dev->lock);
1725         get_dev (dev);
1726         return 0;
1727
1728 enomem:
1729         gadgetfs_unbind (gadget);
1730         return -ENOMEM;
1731 }
1732
1733 static void
1734 gadgetfs_disconnect (struct usb_gadget *gadget)
1735 {
1736         struct dev_data         *dev = get_gadget_data (gadget);
1737
1738         spin_lock (&dev->lock);
1739         if (dev->state == STATE_DEV_UNCONNECTED)
1740                 goto exit;
1741         dev->state = STATE_DEV_UNCONNECTED;
1742
1743         INFO (dev, "disconnected\n");
1744         next_event (dev, GADGETFS_DISCONNECT);
1745         ep0_readable (dev);
1746 exit:
1747         spin_unlock (&dev->lock);
1748 }
1749
1750 static void
1751 gadgetfs_suspend (struct usb_gadget *gadget)
1752 {
1753         struct dev_data         *dev = get_gadget_data (gadget);
1754
1755         INFO (dev, "suspended from state %d\n", dev->state);
1756         spin_lock (&dev->lock);
1757         switch (dev->state) {
1758         case STATE_DEV_SETUP:           // VERY odd... host died??
1759         case STATE_DEV_CONNECTED:
1760         case STATE_DEV_UNCONNECTED:
1761                 next_event (dev, GADGETFS_SUSPEND);
1762                 ep0_readable (dev);
1763                 /* FALLTHROUGH */
1764         default:
1765                 break;
1766         }
1767         spin_unlock (&dev->lock);
1768 }
1769
1770 static struct usb_gadget_driver gadgetfs_driver = {
1771 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1772         .speed          = USB_SPEED_HIGH,
1773 #else
1774         .speed          = USB_SPEED_FULL,
1775 #endif
1776         .function       = (char *) driver_desc,
1777         .bind           = gadgetfs_bind,
1778         .unbind         = gadgetfs_unbind,
1779         .setup          = gadgetfs_setup,
1780         .disconnect     = gadgetfs_disconnect,
1781         .suspend        = gadgetfs_suspend,
1782
1783         .driver = {
1784                 .name           = (char *) shortname,
1785         },
1786 };
1787
1788 /*----------------------------------------------------------------------*/
1789
1790 static void gadgetfs_nop(struct usb_gadget *arg) { }
1791
1792 static int gadgetfs_probe (struct usb_gadget *gadget)
1793 {
1794         CHIP = gadget->name;
1795         return -EISNAM;
1796 }
1797
1798 static struct usb_gadget_driver probe_driver = {
1799         .speed          = USB_SPEED_HIGH,
1800         .bind           = gadgetfs_probe,
1801         .unbind         = gadgetfs_nop,
1802         .setup          = (void *)gadgetfs_nop,
1803         .disconnect     = gadgetfs_nop,
1804         .driver = {
1805                 .name           = "nop",
1806         },
1807 };
1808
1809
1810 /* DEVICE INITIALIZATION
1811  *
1812  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1813  *     status = write (fd, descriptors, sizeof descriptors)
1814  *
1815  * That write establishes the device configuration, so the kernel can
1816  * bind to the controller ... guaranteeing it can handle enumeration
1817  * at all necessary speeds.  Descriptor order is:
1818  *
1819  * . message tag (u32, host order) ... for now, must be zero; it
1820  *      would change to support features like multi-config devices
1821  * . full/low speed config ... all wTotalLength bytes (with interface,
1822  *      class, altsetting, endpoint, and other descriptors)
1823  * . high speed config ... all descriptors, for high speed operation;
1824  *      this one's optional except for high-speed hardware
1825  * . device descriptor
1826  *
1827  * Endpoints are not yet enabled. Drivers must wait until device
1828  * configuration and interface altsetting changes create
1829  * the need to configure (or unconfigure) them.
1830  *
1831  * After initialization, the device stays active for as long as that
1832  * $CHIP file is open.  Events must then be read from that descriptor,
1833  * such as configuration notifications.
1834  */
1835
1836 static int is_valid_config (struct usb_config_descriptor *config)
1837 {
1838         return config->bDescriptorType == USB_DT_CONFIG
1839                 && config->bLength == USB_DT_CONFIG_SIZE
1840                 && config->bConfigurationValue != 0
1841                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1842                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1843         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1844         /* FIXME check lengths: walk to end */
1845 }
1846
1847 static ssize_t
1848 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1849 {
1850         struct dev_data         *dev = fd->private_data;
1851         ssize_t                 value = len, length = len;
1852         unsigned                total;
1853         u32                     tag;
1854         char                    *kbuf;
1855
1856         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1857                 return -EINVAL;
1858
1859         /* we might need to change message format someday */
1860         if (copy_from_user (&tag, buf, 4))
1861                 return -EFAULT;
1862         if (tag != 0)
1863                 return -EINVAL;
1864         buf += 4;
1865         length -= 4;
1866
1867         kbuf = kmalloc (length, GFP_KERNEL);
1868         if (!kbuf)
1869                 return -ENOMEM;
1870         if (copy_from_user (kbuf, buf, length)) {
1871                 kfree (kbuf);
1872                 return -EFAULT;
1873         }
1874
1875         spin_lock_irq (&dev->lock);
1876         value = -EINVAL;
1877         if (dev->buf)
1878                 goto fail;
1879         dev->buf = kbuf;
1880
1881         /* full or low speed config */
1882         dev->config = (void *) kbuf;
1883         total = le16_to_cpu(dev->config->wTotalLength);
1884         if (!is_valid_config (dev->config) || total >= length)
1885                 goto fail;
1886         kbuf += total;
1887         length -= total;
1888
1889         /* optional high speed config */
1890         if (kbuf [1] == USB_DT_CONFIG) {
1891                 dev->hs_config = (void *) kbuf;
1892                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1893                 if (!is_valid_config (dev->hs_config) || total >= length)
1894                         goto fail;
1895                 kbuf += total;
1896                 length -= total;
1897         }
1898
1899         /* could support multiple configs, using another encoding! */
1900
1901         /* device descriptor (tweaked for paranoia) */
1902         if (length != USB_DT_DEVICE_SIZE)
1903                 goto fail;
1904         dev->dev = (void *)kbuf;
1905         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1906                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1907                         || dev->dev->bNumConfigurations != 1)
1908                 goto fail;
1909         dev->dev->bNumConfigurations = 1;
1910         dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1911
1912         /* triggers gadgetfs_bind(); then we can enumerate. */
1913         spin_unlock_irq (&dev->lock);
1914         value = usb_gadget_register_driver (&gadgetfs_driver);
1915         if (value != 0) {
1916                 kfree (dev->buf);
1917                 dev->buf = NULL;
1918         } else {
1919                 /* at this point "good" hardware has for the first time
1920                  * let the USB the host see us.  alternatively, if users
1921                  * unplug/replug that will clear all the error state.
1922                  *
1923                  * note:  everything running before here was guaranteed
1924                  * to choke driver model style diagnostics.  from here
1925                  * on, they can work ... except in cleanup paths that
1926                  * kick in after the ep0 descriptor is closed.
1927                  */
1928                 fd->f_op = &ep0_io_operations;
1929                 value = len;
1930         }
1931         return value;
1932
1933 fail:
1934         spin_unlock_irq (&dev->lock);
1935         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1936         kfree (dev->buf);
1937         dev->buf = NULL;
1938         return value;
1939 }
1940
1941 static int
1942 dev_open (struct inode *inode, struct file *fd)
1943 {
1944         struct dev_data         *dev = inode->i_private;
1945         int                     value = -EBUSY;
1946
1947         spin_lock_irq(&dev->lock);
1948         if (dev->state == STATE_DEV_DISABLED) {
1949                 dev->ev_next = 0;
1950                 dev->state = STATE_DEV_OPENED;
1951                 fd->private_data = dev;
1952                 get_dev (dev);
1953                 value = 0;
1954         }
1955         spin_unlock_irq(&dev->lock);
1956         return value;
1957 }
1958
1959 static const struct file_operations dev_init_operations = {
1960         .owner =        THIS_MODULE,
1961         .llseek =       no_llseek,
1962
1963         .open =         dev_open,
1964         .write =        dev_config,
1965         .fasync =       ep0_fasync,
1966         .unlocked_ioctl = dev_ioctl,
1967         .release =      dev_release,
1968 };
1969
1970 /*----------------------------------------------------------------------*/
1971
1972 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1973  *
1974  * Mounting the filesystem creates a controller file, used first for
1975  * device configuration then later for event monitoring.
1976  */
1977
1978
1979 /* FIXME PAM etc could set this security policy without mount options
1980  * if epfiles inherited ownership and permissons from ep0 ...
1981  */
1982
1983 static unsigned default_uid;
1984 static unsigned default_gid;
1985 static unsigned default_perm = S_IRUSR | S_IWUSR;
1986
1987 module_param (default_uid, uint, 0644);
1988 module_param (default_gid, uint, 0644);
1989 module_param (default_perm, uint, 0644);
1990
1991
1992 static struct inode *
1993 gadgetfs_make_inode (struct super_block *sb,
1994                 void *data, const struct file_operations *fops,
1995                 int mode)
1996 {
1997         struct inode *inode = new_inode (sb);
1998
1999         if (inode) {
2000                 inode->i_mode = mode;
2001                 inode->i_uid = default_uid;
2002                 inode->i_gid = default_gid;
2003                 inode->i_atime = inode->i_mtime = inode->i_ctime
2004                                 = CURRENT_TIME;
2005                 inode->i_private = data;
2006                 inode->i_fop = fops;
2007         }
2008         return inode;
2009 }
2010
2011 /* creates in fs root directory, so non-renamable and non-linkable.
2012  * so inode and dentry are paired, until device reconfig.
2013  */
2014 static struct inode *
2015 gadgetfs_create_file (struct super_block *sb, char const *name,
2016                 void *data, const struct file_operations *fops,
2017                 struct dentry **dentry_p)
2018 {
2019         struct dentry   *dentry;
2020         struct inode    *inode;
2021
2022         dentry = d_alloc_name(sb->s_root, name);
2023         if (!dentry)
2024                 return NULL;
2025
2026         inode = gadgetfs_make_inode (sb, data, fops,
2027                         S_IFREG | (default_perm & S_IRWXUGO));
2028         if (!inode) {
2029                 dput(dentry);
2030                 return NULL;
2031         }
2032         d_add (dentry, inode);
2033         *dentry_p = dentry;
2034         return inode;
2035 }
2036
2037 static const struct super_operations gadget_fs_operations = {
2038         .statfs =       simple_statfs,
2039         .drop_inode =   generic_delete_inode,
2040 };
2041
2042 static int
2043 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2044 {
2045         struct inode    *inode;
2046         struct dentry   *d;
2047         struct dev_data *dev;
2048
2049         if (the_device)
2050                 return -ESRCH;
2051
2052         /* fake probe to determine $CHIP */
2053         (void) usb_gadget_register_driver (&probe_driver);
2054         if (!CHIP)
2055                 return -ENODEV;
2056
2057         /* superblock */
2058         sb->s_blocksize = PAGE_CACHE_SIZE;
2059         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2060         sb->s_magic = GADGETFS_MAGIC;
2061         sb->s_op = &gadget_fs_operations;
2062         sb->s_time_gran = 1;
2063
2064         /* root inode */
2065         inode = gadgetfs_make_inode (sb,
2066                         NULL, &simple_dir_operations,
2067                         S_IFDIR | S_IRUGO | S_IXUGO);
2068         if (!inode)
2069                 goto enomem0;
2070         inode->i_op = &simple_dir_inode_operations;
2071         if (!(d = d_alloc_root (inode)))
2072                 goto enomem1;
2073         sb->s_root = d;
2074
2075         /* the ep0 file is named after the controller we expect;
2076          * user mode code can use it for sanity checks, like we do.
2077          */
2078         dev = dev_new ();
2079         if (!dev)
2080                 goto enomem2;
2081
2082         dev->sb = sb;
2083         if (!gadgetfs_create_file (sb, CHIP,
2084                                 dev, &dev_init_operations,
2085                                 &dev->dentry))
2086                 goto enomem3;
2087
2088         /* other endpoint files are available after hardware setup,
2089          * from binding to a controller.
2090          */
2091         the_device = dev;
2092         return 0;
2093
2094 enomem3:
2095         put_dev (dev);
2096 enomem2:
2097         dput (d);
2098 enomem1:
2099         iput (inode);
2100 enomem0:
2101         return -ENOMEM;
2102 }
2103
2104 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2105 static int
2106 gadgetfs_get_sb (struct file_system_type *t, int flags,
2107                 const char *path, void *opts, struct vfsmount *mnt)
2108 {
2109         return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt);
2110 }
2111
2112 static void
2113 gadgetfs_kill_sb (struct super_block *sb)
2114 {
2115         kill_litter_super (sb);
2116         if (the_device) {
2117                 put_dev (the_device);
2118                 the_device = NULL;
2119         }
2120 }
2121
2122 /*----------------------------------------------------------------------*/
2123
2124 static struct file_system_type gadgetfs_type = {
2125         .owner          = THIS_MODULE,
2126         .name           = shortname,
2127         .get_sb         = gadgetfs_get_sb,
2128         .kill_sb        = gadgetfs_kill_sb,
2129 };
2130
2131 /*----------------------------------------------------------------------*/
2132
2133 static int __init init (void)
2134 {
2135         int status;
2136
2137         status = register_filesystem (&gadgetfs_type);
2138         if (status == 0)
2139                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2140                         shortname, driver_desc);
2141         return status;
2142 }
2143 module_init (init);
2144
2145 static void __exit cleanup (void)
2146 {
2147         pr_debug ("unregister %s\n", shortname);
2148         unregister_filesystem (&gadgetfs_type);
2149 }
2150 module_exit (cleanup);
2151