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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/slab.h>
  34 #include <linux/poll.h>
  35 #include <linux/smp_lock.h>
  36
  37 #include <linux/device.h>
  38 #include <linux/moduleparam.h>
  39
  40 #include <linux/usb/gadgetfs.h>
  41 #include <linux/usb/gadget.h>
  42
  43
  44 /*
  45  * The gadgetfs API maps each endpoint to a file descriptor so that you
  46  * can use standard synchronous read/write calls for I/O.  There's some
  47  * O_NONBLOCK and O_ASYNC/FASYNC style i/o support.  Example usermode
  48  * drivers show how this works in practice.  You can also use AIO to
  49  * eliminate I/O gaps between requests, to help when streaming data.
  50  *
  51  * Key parts that must be USB-specific are protocols defining how the
  52  * read/write operations relate to the hardware state machines.  There
  53  * are two types of files.  One type is for the device, implementing ep0.
  54  * The other type is for each IN or OUT endpoint.  In both cases, the
  55  * user mode driver must configure the hardware before using it.
  56  *
  57  * - First, dev_config() is called when /dev/gadget/$CHIP is configured
  58  *   (by writing configuration and device descriptors).  Afterwards it
  59  *   may serve as a source of device events, used to handle all control
  60  *   requests other than basic enumeration.
  61  *
  62  * - Then, after a SET_CONFIGURATION control request, ep_config() is
  63  *   called when each /dev/gadget/ep* file is configured (by writing
  64  *   endpoint descriptors).  Afterwards these files are used to write()
  65  *   IN data or to read() OUT data.  To halt the endpoint, a "wrong
  66  *   direction" request is issued (like reading an IN endpoint).
  67  *
  68  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
  69  * not possible on all hardware.  For example, precise fault handling with
  70  * respect to data left in endpoint fifos after aborted operations; or
  71  * selective clearing of endpoint halts, to implement SET_INTERFACE.
  72  */
  73
  74 #define DRIVER_DESC     "USB Gadget filesystem"
  75 #define DRIVER_VERSION  "24 Aug 2004"
  76
  77 static const char driver_desc [] = DRIVER_DESC;
  78 static const char shortname [] = "gadgetfs";
  79
  80 MODULE_DESCRIPTION (DRIVER_DESC);
  81 MODULE_AUTHOR ("David Brownell");
  82 MODULE_LICENSE ("GPL");
  83
  84
  85 /*----------------------------------------------------------------------*/
  86
  87 #define GADGETFS_MAGIC          0xaee71ee7
  88 #define DMA_ADDR_INVALID        (~(dma_addr_t)0)
  89
  90 /* /dev/gadget/$CHIP represents ep0 and the whole device */
  91 enum ep0_state {
  92         /* DISBLED is the initial state.
  93          */
  94         STATE_DEV_DISABLED = 0,
  95
  96         /* Only one open() of /dev/gadget/$CHIP; only one file tracks
  97          * ep0/device i/o modes and binding to the controller.  Driver
  98          * must always write descriptors to initialize the device, then
  99          * the device becomes UNCONNECTED until enumeration.
 100          */
 101         STATE_DEV_OPENED,
 102
 103         /* From then on, ep0 fd is in either of two basic modes:
 104          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
 105          * - SETUP: read/write will transfer control data and succeed;
 106          *   or if "wrong direction", performs protocol stall
 107          */
 108         STATE_DEV_UNCONNECTED,
 109         STATE_DEV_CONNECTED,
 110         STATE_DEV_SETUP,
 111
 112         /* UNBOUND means the driver closed ep0, so the device won't be
 113          * accessible again (DEV_DISABLED) until all fds are closed.
 114          */
 115         STATE_DEV_UNBOUND,
 116 };
 117
 118 /* enough for the whole queue: most events invalidate others */
 119 #define N_EVENT                 5
 120
 121 struct dev_data {
 122         spinlock_t                      lock;
 123         atomic_t                        count;
 124         enum ep0_state                  state;          /* P: lock */
 125         struct usb_gadgetfs_event       event [N_EVENT];
 126         unsigned                        ev_next;
 127         struct fasync_struct            *fasync;
 128         u8                              current_config;
 129
 130         /* drivers reading ep0 MUST handle control requests (SETUP)
 131          * reported that way; else the host will time out.
 132          */
 133         unsigned                        usermode_setup : 1,
 134                                         setup_in : 1,
 135                                         setup_can_stall : 1,
 136                                         setup_out_ready : 1,
 137                                         setup_out_error : 1,
 138                                         setup_abort : 1;
 139         unsigned                        setup_wLength;
 140
 141         /* the rest is basically write-once */
 142         struct usb_config_descriptor    *config, *hs_config;
 143         struct usb_device_descriptor    *dev;
 144         struct usb_request              *req;
 145         struct usb_gadget               *gadget;
 146         struct list_head                epfiles;
 147         void                            *buf;
 148         wait_queue_head_t               wait;
 149         struct super_block              *sb;
 150         struct dentry                   *dentry;
 151
 152         /* except this scratch i/o buffer for ep0 */
 153         u8                              rbuf [256];
 154 };
 155
 156 static inline void get_dev (struct dev_data *data)
 157 {
 158         atomic_inc (&data->count);
 159 }
 160
 161 static void put_dev (struct dev_data *data)
 162 {
 163         if (likely (!atomic_dec_and_test (&data->count)))
 164                 return;
 165         /* needs no more cleanup */
 166         BUG_ON (waitqueue_active (&data->wait));
 167         kfree (data);
 168 }
 169
 170 static struct dev_data *dev_new (void)
 171 {
 172         struct dev_data         *dev;
 173
 174         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 175         if (!dev)
 176                 return NULL;
 177         dev->state = STATE_DEV_DISABLED;
 178         atomic_set (&dev->count, 1);
 179         spin_lock_init (&dev->lock);
 180         INIT_LIST_HEAD (&dev->epfiles);
 181         init_waitqueue_head (&dev->wait);
 182         return dev;
 183 }
 184
 185 /*----------------------------------------------------------------------*/
 186
 187 /* other /dev/gadget/$ENDPOINT files represent endpoints */
 188 enum ep_state {
 189         STATE_EP_DISABLED = 0,
 190         STATE_EP_READY,
 191         STATE_EP_ENABLED,
 192         STATE_EP_UNBOUND,
 193 };
 194
 195 struct ep_data {
 196         struct semaphore                lock;
 197         enum ep_state                   state;
 198         atomic_t                        count;
 199         struct dev_data                 *dev;
 200         /* must hold dev->lock before accessing ep or req */
 201         struct usb_ep                   *ep;
 202         struct usb_request              *req;
 203         ssize_t                         status;
 204         char                            name [16];
 205         struct usb_endpoint_descriptor  desc, hs_desc;
 206         struct list_head                epfiles;
 207         wait_queue_head_t               wait;
 208         struct dentry                   *dentry;
 209         struct inode                    *inode;
 210 };
 211
 212 static inline void get_ep (struct ep_data *data)
 213 {
 214         atomic_inc (&data->count);
 215 }
 216
 217 static void put_ep (struct ep_data *data)
 218 {
 219         if (likely (!atomic_dec_and_test (&data->count)))
 220                 return;
 221         put_dev (data->dev);
 222         /* needs no more cleanup */
 223         BUG_ON (!list_empty (&data->epfiles));
 224         BUG_ON (waitqueue_active (&data->wait));
 225         kfree (data);
 226 }
 227
 228 /*----------------------------------------------------------------------*/
 229
 230 /* most "how to use the hardware" policy choices are in userspace:
 231  * mapping endpoint roles (which the driver needs) to the capabilities
 232  * which the usb controller has.  most of those capabilities are exposed
 233  * implicitly, starting with the driver name and then endpoint names.
 234  */
 235
 236 static const char *CHIP;
 237
 238 /*----------------------------------------------------------------------*/
 239
 240 /* NOTE:  don't use dev_printk calls before binding to the gadget
 241  * at the end of ep0 configuration, or after unbind.
 242  */
 243
 244 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
 245 #define xprintk(d,level,fmt,args...) \
 246         printk(level "%s: " fmt , shortname , ## args)
 247
 248 #ifdef DEBUG
 249 #define DBG(dev,fmt,args...) \
 250         xprintk(dev , KERN_DEBUG , fmt , ## args)
 251 #else
 252 #define DBG(dev,fmt,args...) \
 253         do { } while (0)
 254 #endif /* DEBUG */
 255
 256 #ifdef VERBOSE_DEBUG
 257 #define VDEBUG  DBG
 258 #else
 259 #define VDEBUG(dev,fmt,args...) \
 260         do { } while (0)
 261 #endif /* DEBUG */
 262
 263 #define ERROR(dev,fmt,args...) \
 264         xprintk(dev , KERN_ERR , fmt , ## args)
 265 #define INFO(dev,fmt,args...) \
 266         xprintk(dev , KERN_INFO , fmt , ## args)
 267
 268
 269 /*----------------------------------------------------------------------*/
 270
 271 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 272  *
 273  * After opening, configure non-control endpoints.  Then use normal
 274  * stream read() and write() requests; and maybe ioctl() to get more
 275  * precise FIFO status when recovering from cancellation.
 276  */
 277
 278 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 279 {
 280         struct ep_data  *epdata = ep->driver_data;
 281
 282         if (!req->context)
 283                 return;
 284         if (req->status)
 285                 epdata->status = req->status;
 286         else
 287                 epdata->status = req->actual;
 288         complete ((struct completion *)req->context);
 289 }
 290
 291 /* tasklock endpoint, returning when it's connected.
 292  * still need dev->lock to use epdata->ep.
 293  */
 294 static int
 295 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
 296 {
 297         int     val;
 298
 299         if (f_flags & O_NONBLOCK) {
 300                 if (down_trylock (&epdata->lock) != 0)
 301                         goto nonblock;
 302                 if (epdata->state != STATE_EP_ENABLED) {
 303                         up (&epdata->lock);
 304 nonblock:
 305                         val = -EAGAIN;
 306                 } else
 307                         val = 0;
 308                 return val;
 309         }
 310
 311         if ((val = down_interruptible (&epdata->lock)) < 0)
 312                 return val;
 313
 314         switch (epdata->state) {
 315         case STATE_EP_ENABLED:
 316                 break;
 317         // case STATE_EP_DISABLED:              /* "can't happen" */
 318         // case STATE_EP_READY:                 /* "can't happen" */
 319         default:                                /* error! */
 320                 pr_debug ("%s: ep %p not available, state %d\n",
 321                                 shortname, epdata, epdata->state);
 322                 // FALLTHROUGH
 323         case STATE_EP_UNBOUND:                  /* clean disconnect */
 324                 val = -ENODEV;
 325                 up (&epdata->lock);
 326         }
 327         return val;
 328 }
 329
 330 static ssize_t
 331 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 332 {
 333         DECLARE_COMPLETION_ONSTACK (done);
 334         int value;
 335
 336         spin_lock_irq (&epdata->dev->lock);
 337         if (likely (epdata->ep != NULL)) {
 338                 struct usb_request      *req = epdata->req;
 339
 340                 req->context = &done;
 341                 req->complete = epio_complete;
 342                 req->buf = buf;
 343                 req->length = len;
 344                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 345         } else
 346                 value = -ENODEV;
 347         spin_unlock_irq (&epdata->dev->lock);
 348
 349         if (likely (value == 0)) {
 350                 value = wait_event_interruptible (done.wait, done.done);
 351                 if (value != 0) {
 352                         spin_lock_irq (&epdata->dev->lock);
 353                         if (likely (epdata->ep != NULL)) {
 354                                 DBG (epdata->dev, "%s i/o interrupted\n",
 355                                                 epdata->name);
 356                                 usb_ep_dequeue (epdata->ep, epdata->req);
 357                                 spin_unlock_irq (&epdata->dev->lock);
 358
 359                                 wait_event (done.wait, done.done);
 360                                 if (epdata->status == -ECONNRESET)
 361                                         epdata->status = -EINTR;
 362                         } else {
 363                                 spin_unlock_irq (&epdata->dev->lock);
 364
 365                                 DBG (epdata->dev, "endpoint gone\n");
 366                                 epdata->status = -ENODEV;
 367                         }
 368                 }
 369                 return epdata->status;
 370         }
 371         return value;
 372 }
 373
 374
 375 /* handle a synchronous OUT bulk/intr/iso transfer */
 376 static ssize_t
 377 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 378 {
 379         struct ep_data          *data = fd->private_data;
 380         void                    *kbuf;
 381         ssize_t                 value;
 382
 383         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 384                 return value;
 385
 386         /* halt any endpoint by doing a "wrong direction" i/o call */
 387         if (data->desc.bEndpointAddress & USB_DIR_IN) {
 388                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 389                                 == USB_ENDPOINT_XFER_ISOC)
 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 (!(data->desc.bEndpointAddress & USB_DIR_IN)) {
 432                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 433                                 == USB_ENDPOINT_XFER_ISOC)
 434                         return -EINVAL;
 435                 DBG (data->dev, "%s halt\n", data->name);
 436                 spin_lock_irq (&data->dev->lock);
 437                 if (likely (data->ep != NULL))
 438                         usb_ep_set_halt (data->ep);
 439                 spin_unlock_irq (&data->dev->lock);
 440                 up (&data->lock);
 441                 return -EBADMSG;
 442         }
 443
 444         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
 445
 446         value = -ENOMEM;
 447         kbuf = kmalloc (len, GFP_KERNEL);
 448         if (!kbuf)
 449                 goto free1;
 450         if (copy_from_user (kbuf, buf, len)) {
 451                 value = -EFAULT;
 452                 goto free1;
 453         }
 454
 455         value = ep_io (data, kbuf, len);
 456         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
 457                 data->name, len, (int) value);
 458 free1:
 459         up (&data->lock);
 460         kfree (kbuf);
 461         return value;
 462 }
 463
 464 static int
 465 ep_release (struct inode *inode, struct file *fd)
 466 {
 467         struct ep_data          *data = fd->private_data;
 468         int value;
 469
 470         if ((value = down_interruptible(&data->lock)) < 0)
 471                 return value;
 472
 473         /* clean up if this can be reopened */
 474         if (data->state != STATE_EP_UNBOUND) {
 475                 data->state = STATE_EP_DISABLED;
 476                 data->desc.bDescriptorType = 0;
 477                 data->hs_desc.bDescriptorType = 0;
 478                 usb_ep_disable(data->ep);
 479         }
 480         up (&data->lock);
 481         put_ep (data);
 482         return 0;
 483 }
 484
 485 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
 486 {
 487         struct ep_data          *data = fd->private_data;
 488         int                     status;
 489
 490         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 491                 return status;
 492
 493         spin_lock_irq (&data->dev->lock);
 494         if (likely (data->ep != NULL)) {
 495                 switch (code) {
 496                 case GADGETFS_FIFO_STATUS:
 497                         status = usb_ep_fifo_status (data->ep);
 498                         break;
 499                 case GADGETFS_FIFO_FLUSH:
 500                         usb_ep_fifo_flush (data->ep);
 501                         break;
 502                 case GADGETFS_CLEAR_HALT:
 503                         status = usb_ep_clear_halt (data->ep);
 504                         break;
 505                 default:
 506                         status = -ENOTTY;
 507                 }
 508         } else
 509                 status = -ENODEV;
 510         spin_unlock_irq (&data->dev->lock);
 511         up (&data->lock);
 512         return status;
 513 }
 514
 515 /*----------------------------------------------------------------------*/
 516
 517 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 518
 519 struct kiocb_priv {
 520         struct usb_request      *req;
 521         struct ep_data          *epdata;
 522         void                    *buf;
 523         const struct iovec      *iv;
 524         unsigned long           nr_segs;
 525         unsigned                actual;
 526 };
 527
 528 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
 529 {
 530         struct kiocb_priv       *priv = iocb->private;
 531         struct ep_data          *epdata;
 532         int                     value;
 533
 534         local_irq_disable();
 535         epdata = priv->epdata;
 536         // spin_lock(&epdata->dev->lock);
 537         kiocbSetCancelled(iocb);
 538         if (likely(epdata && epdata->ep && priv->req))
 539                 value = usb_ep_dequeue (epdata->ep, priv->req);
 540         else
 541                 value = -EINVAL;
 542         // spin_unlock(&epdata->dev->lock);
 543         local_irq_enable();
 544
 545         aio_put_req(iocb);
 546         return value;
 547 }
 548
 549 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
 550 {
 551         struct kiocb_priv       *priv = iocb->private;
 552         ssize_t                 len, total;
 553         void                    *to_copy;
 554         int                     i;
 555
 556         /* we "retry" to get the right mm context for this: */
 557
 558         /* copy stuff into user buffers */
 559         total = priv->actual;
 560         len = 0;
 561         to_copy = priv->buf;
 562         for (i=0; i < priv->nr_segs; i++) {
 563                 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
 564
 565                 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
 566                         if (len == 0)
 567                                 len = -EFAULT;
 568                         break;
 569                 }
 570
 571                 total -= this;
 572                 len += this;
 573                 to_copy += this;
 574                 if (total == 0)
 575                         break;
 576         }
 577         kfree(priv->buf);
 578         kfree(priv);
 579         return len;
 580 }
 581
 582 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 583 {
 584         struct kiocb            *iocb = req->context;
 585         struct kiocb_priv       *priv = iocb->private;
 586         struct ep_data          *epdata = priv->epdata;
 587
 588         /* lock against disconnect (and ideally, cancel) */
 589         spin_lock(&epdata->dev->lock);
 590         priv->req = NULL;
 591         priv->epdata = NULL;
 592
 593         /* if this was a write or a read returning no data then we
 594          * don't need to copy anything to userspace, so we can
 595          * complete the aio request immediately.
 596          */
 597         if (priv->iv == NULL || unlikely(req->actual == 0)) {
 598                 kfree(req->buf);
 599                 kfree(priv);
 600                 iocb->private = NULL;
 601                 /* aio_complete() reports bytes-transferred _and_ faults */
 602                 aio_complete(iocb, req->actual ? req->actual : req->status,
 603                                 req->status);
 604         } else {
 605                 /* retry() won't report both; so we hide some faults */
 606                 if (unlikely(0 != req->status))
 607                         DBG(epdata->dev, "%s fault %d len %d\n",
 608                                 ep->name, req->status, req->actual);
 609
 610                 priv->buf = req->buf;
 611                 priv->actual = req->actual;
 612                 kick_iocb(iocb);
 613         }
 614         spin_unlock(&epdata->dev->lock);
 615
 616         usb_ep_free_request(ep, req);
 617         put_ep(epdata);
 618 }
 619
 620 static ssize_t
 621 ep_aio_rwtail(
 622         struct kiocb    *iocb,
 623         char            *buf,
 624         size_t          len,
 625         struct ep_data  *epdata,
 626         const struct iovec *iv,
 627         unsigned long   nr_segs
 628 )
 629 {
 630         struct kiocb_priv       *priv;
 631         struct usb_request      *req;
 632         ssize_t                 value;
 633
 634         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 635         if (!priv) {
 636                 value = -ENOMEM;
 637 fail:
 638                 kfree(buf);
 639                 return value;
 640         }
 641         iocb->private = priv;
 642         priv->iv = iv;
 643         priv->nr_segs = nr_segs;
 644
 645         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 646         if (unlikely(value < 0)) {
 647                 kfree(priv);
 648                 goto fail;
 649         }
 650
 651         iocb->ki_cancel = ep_aio_cancel;
 652         get_ep(epdata);
 653         priv->epdata = epdata;
 654         priv->actual = 0;
 655
 656         /* each kiocb is coupled to one usb_request, but we can't
 657          * allocate or submit those if the host disconnected.
 658          */
 659         spin_lock_irq(&epdata->dev->lock);
 660         if (likely(epdata->ep)) {
 661                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 662                 if (likely(req)) {
 663                         priv->req = req;
 664                         req->buf = buf;
 665                         req->length = len;
 666                         req->complete = ep_aio_complete;
 667                         req->context = iocb;
 668                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 669                         if (unlikely(0 != value))
 670                                 usb_ep_free_request(epdata->ep, req);
 671                 } else
 672                         value = -EAGAIN;
 673         } else
 674                 value = -ENODEV;
 675         spin_unlock_irq(&epdata->dev->lock);
 676
 677         up(&epdata->lock);
 678
 679         if (unlikely(value)) {
 680                 kfree(priv);
 681                 put_ep(epdata);
 682         } else
 683                 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
 684         return value;
 685 }
 686
 687 static ssize_t
 688 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
 689                 unsigned long nr_segs, loff_t o)
 690 {
 691         struct ep_data          *epdata = iocb->ki_filp->private_data;
 692         char                    *buf;
 693
 694         if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN))
 695                 return -EINVAL;
 696
 697         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 698         if (unlikely(!buf))
 699                 return -ENOMEM;
 700
 701         iocb->ki_retry = ep_aio_read_retry;
 702         return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
 703 }
 704
 705 static ssize_t
 706 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
 707                 unsigned long nr_segs, loff_t o)
 708 {
 709         struct ep_data          *epdata = iocb->ki_filp->private_data;
 710         char                    *buf;
 711         size_t                  len = 0;
 712         int                     i = 0;
 713
 714         if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN)))
 715                 return -EINVAL;
 716
 717         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 718         if (unlikely(!buf))
 719                 return -ENOMEM;
 720
 721         for (i=0; i < nr_segs; i++) {
 722                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
 723                                 iov[i].iov_len) != 0)) {
 724                         kfree(buf);
 725                         return -EFAULT;
 726                 }
 727                 len += iov[i].iov_len;
 728         }
 729         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
 730 }
 731
 732 /*----------------------------------------------------------------------*/
 733
 734 /* used after endpoint configuration */
 735 static const struct file_operations ep_io_operations = {
 736         .owner =        THIS_MODULE,
 737         .llseek =       no_llseek,
 738
 739         .read =         ep_read,
 740         .write =        ep_write,
 741         .unlocked_ioctl = ep_ioctl,
 742         .release =      ep_release,
 743
 744         .aio_read =     ep_aio_read,
 745         .aio_write =    ep_aio_write,
 746 };
 747
 748 /* ENDPOINT INITIALIZATION
 749  *
 750  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 751  *     status = write (fd, descriptors, sizeof descriptors)
 752  *
 753  * That write establishes the endpoint configuration, configuring
 754  * the controller to process bulk, interrupt, or isochronous transfers
 755  * at the right maxpacket size, and so on.
 756  *
 757  * The descriptors are message type 1, identified by a host order u32
 758  * at the beginning of what's written.  Descriptor order is: full/low
 759  * speed descriptor, then optional high speed descriptor.
 760  */
 761 static ssize_t
 762 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 763 {
 764         struct ep_data          *data = fd->private_data;
 765         struct usb_ep           *ep;
 766         u32                     tag;
 767         int                     value, length = len;
 768
 769         if ((value = down_interruptible (&data->lock)) < 0)
 770                 return value;
 771
 772         if (data->state != STATE_EP_READY) {
 773                 value = -EL2HLT;
 774                 goto fail;
 775         }
 776
 777         value = len;
 778         if (len < USB_DT_ENDPOINT_SIZE + 4)
 779                 goto fail0;
 780
 781         /* we might need to change message format someday */
 782         if (copy_from_user (&tag, buf, 4)) {
 783                 goto fail1;
 784         }
 785         if (tag != 1) {
 786                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 787                 goto fail0;
 788         }
 789         buf += 4;
 790         len -= 4;
 791
 792         /* NOTE:  audio endpoint extensions not accepted here;
 793          * just don't include the extra bytes.
 794          */
 795
 796         /* full/low speed descriptor, then high speed */
 797         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 798                 goto fail1;
 799         }
 800         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 801                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 802                 goto fail0;
 803         if (len != USB_DT_ENDPOINT_SIZE) {
 804                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 805                         goto fail0;
 806                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 807                                         USB_DT_ENDPOINT_SIZE)) {
 808                         goto fail1;
 809                 }
 810                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 811                                 || data->hs_desc.bDescriptorType
 812                                         != USB_DT_ENDPOINT) {
 813                         DBG(data->dev, "config %s, bad hs length or type\n",
 814                                         data->name);
 815                         goto fail0;
 816                 }
 817         }
 818
 819         spin_lock_irq (&data->dev->lock);
 820         if (data->dev->state == STATE_DEV_UNBOUND) {
 821                 value = -ENOENT;
 822                 goto gone;
 823         } else if ((ep = data->ep) == NULL) {
 824                 value = -ENODEV;
 825                 goto gone;
 826         }
 827         switch (data->dev->gadget->speed) {
 828         case USB_SPEED_LOW:
 829         case USB_SPEED_FULL:
 830                 value = usb_ep_enable (ep, &data->desc);
 831                 if (value == 0)
 832                         data->state = STATE_EP_ENABLED;
 833                 break;
 834 #ifdef  CONFIG_USB_GADGET_DUALSPEED
 835         case USB_SPEED_HIGH:
 836                 /* fails if caller didn't provide that descriptor... */
 837                 value = usb_ep_enable (ep, &data->hs_desc);
 838                 if (value == 0)
 839                         data->state = STATE_EP_ENABLED;
 840                 break;
 841 #endif
 842         default:
 843                 DBG(data->dev, "unconnected, %s init abandoned\n",
 844                                 data->name);
 845                 value = -EINVAL;
 846         }
 847         if (value == 0) {
 848                 fd->f_op = &ep_io_operations;
 849                 value = length;
 850         }
 851 gone:
 852         spin_unlock_irq (&data->dev->lock);
 853         if (value < 0) {
 854 fail:
 855                 data->desc.bDescriptorType = 0;
 856                 data->hs_desc.bDescriptorType = 0;
 857         }
 858         up (&data->lock);
 859         return value;
 860 fail0:
 861         value = -EINVAL;
 862         goto fail;
 863 fail1:
 864         value = -EFAULT;
 865         goto fail;
 866 }
 867
 868 static int
 869 ep_open (struct inode *inode, struct file *fd)
 870 {
 871         struct ep_data          *data = inode->i_private;
 872         int                     value = -EBUSY;
 873
 874         if (down_interruptible (&data->lock) != 0)
 875                 return -EINTR;
 876         spin_lock_irq (&data->dev->lock);
 877         if (data->dev->state == STATE_DEV_UNBOUND)
 878                 value = -ENOENT;
 879         else if (data->state == STATE_EP_DISABLED) {
 880                 value = 0;
 881                 data->state = STATE_EP_READY;
 882                 get_ep (data);
 883                 fd->private_data = data;
 884                 VDEBUG (data->dev, "%s ready\n", data->name);
 885         } else
 886                 DBG (data->dev, "%s state %d\n",
 887                         data->name, data->state);
 888         spin_unlock_irq (&data->dev->lock);
 889         up (&data->lock);
 890         return value;
 891 }
 892
 893 /* used before endpoint configuration */
 894 static const struct file_operations ep_config_operations = {
 895         .owner =        THIS_MODULE,
 896         .llseek =       no_llseek,
 897
 898         .open =         ep_open,
 899         .write =        ep_config,
 900         .release =      ep_release,
 901 };
 902
 903 /*----------------------------------------------------------------------*/
 904
 905 /* EP0 IMPLEMENTATION can be partly in userspace.
 906  *
 907  * Drivers that use this facility receive various events, including
 908  * control requests the kernel doesn't handle.  Drivers that don't
 909  * use this facility may be too simple-minded for real applications.
 910  */
 911
 912 static inline void ep0_readable (struct dev_data *dev)
 913 {
 914         wake_up (&dev->wait);
 915         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 916 }
 917
 918 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 919 {
 920         struct dev_data         *dev = ep->driver_data;
 921
 922         if (req->buf != dev->rbuf) {
 923                 kfree(req->buf);
 924                 req->buf = dev->rbuf;
 925                 req->dma = DMA_ADDR_INVALID;
 926         }
 927         req->complete = epio_complete;
 928         dev->setup_out_ready = 0;
 929 }
 930
 931 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 932 {
 933         struct dev_data         *dev = ep->driver_data;
 934         unsigned long           flags;
 935         int                     free = 1;
 936
 937         /* for control OUT, data must still get to userspace */
 938         spin_lock_irqsave(&dev->lock, flags);
 939         if (!dev->setup_in) {
 940                 dev->setup_out_error = (req->status != 0);
 941                 if (!dev->setup_out_error)
 942                         free = 0;
 943                 dev->setup_out_ready = 1;
 944                 ep0_readable (dev);
 945         }
 946
 947         /* clean up as appropriate */
 948         if (free && req->buf != &dev->rbuf)
 949                 clean_req (ep, req);
 950         req->complete = epio_complete;
 951         spin_unlock_irqrestore(&dev->lock, flags);
 952 }
 953
 954 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 955 {
 956         struct dev_data *dev = ep->driver_data;
 957
 958         if (dev->setup_out_ready) {
 959                 DBG (dev, "ep0 request busy!\n");
 960                 return -EBUSY;
 961         }
 962         if (len > sizeof (dev->rbuf))
 963                 req->buf = kmalloc(len, GFP_ATOMIC);
 964         if (req->buf == NULL) {
 965                 req->buf = dev->rbuf;
 966                 return -ENOMEM;
 967         }
 968         req->complete = ep0_complete;
 969         req->length = len;
 970         req->zero = 0;
 971         return 0;
 972 }
 973
 974 static ssize_t
 975 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 976 {
 977         struct dev_data                 *dev = fd->private_data;
 978         ssize_t                         retval;
 979         enum ep0_state                  state;
 980
 981         spin_lock_irq (&dev->lock);
 982
 983         /* report fd mode change before acting on it */
 984         if (dev->setup_abort) {
 985                 dev->setup_abort = 0;
 986                 retval = -EIDRM;
 987                 goto done;
 988         }
 989
 990         /* control DATA stage */
 991         if ((state = dev->state) == STATE_DEV_SETUP) {
 992
 993                 if (dev->setup_in) {            /* stall IN */
 994                         VDEBUG(dev, "ep0in stall\n");
 995                         (void) usb_ep_set_halt (dev->gadget->ep0);
 996                         retval = -EL2HLT;
 997                         dev->state = STATE_DEV_CONNECTED;
 998
 999                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
1000                         struct usb_ep           *ep = dev->gadget->ep0;
1001                         struct usb_request      *req = dev->req;
1002
1003                         if ((retval = setup_req (ep, req, 0)) == 0)
1004                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1005                         dev->state = STATE_DEV_CONNECTED;
1006
1007                         /* assume that was SET_CONFIGURATION */
1008                         if (dev->current_config) {
1009                                 unsigned power;
1010
1011                                 if (gadget_is_dualspeed(dev->gadget)
1012                                                 && (dev->gadget->speed
1013                                                         == USB_SPEED_HIGH))
1014                                         power = dev->hs_config->bMaxPower;
1015                                 else
1016                                         power = dev->config->bMaxPower;
1017                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1018                         }
1019
1020                 } else {                        /* collect OUT data */
1021                         if ((fd->f_flags & O_NONBLOCK) != 0
1022                                         && !dev->setup_out_ready) {
1023                                 retval = -EAGAIN;
1024                                 goto done;
1025                         }
1026                         spin_unlock_irq (&dev->lock);
1027                         retval = wait_event_interruptible (dev->wait,
1028                                         dev->setup_out_ready != 0);
1029
1030                         /* FIXME state could change from under us */
1031                         spin_lock_irq (&dev->lock);
1032                         if (retval)
1033                                 goto done;
1034
1035                         if (dev->state != STATE_DEV_SETUP) {
1036                                 retval = -ECANCELED;
1037                                 goto done;
1038                         }
1039                         dev->state = STATE_DEV_CONNECTED;
1040
1041                         if (dev->setup_out_error)
1042                                 retval = -EIO;
1043                         else {
1044                                 len = min (len, (size_t)dev->req->actual);
1045 // FIXME don't call this with the spinlock held ...
1046                                 if (copy_to_user (buf, dev->req->buf, len))
1047                                         retval = -EFAULT;
1048                                 clean_req (dev->gadget->ep0, dev->req);
1049                                 /* NOTE userspace can't yet choose to stall */
1050                         }
1051                 }
1052                 goto done;
1053         }
1054
1055         /* else normal: return event data */
1056         if (len < sizeof dev->event [0]) {
1057                 retval = -EINVAL;
1058                 goto done;
1059         }
1060         len -= len % sizeof (struct usb_gadgetfs_event);
1061         dev->usermode_setup = 1;
1062
1063 scan:
1064         /* return queued events right away */
1065         if (dev->ev_next != 0) {
1066                 unsigned                i, n;
1067
1068                 n = len / sizeof (struct usb_gadgetfs_event);
1069                 if (dev->ev_next < n)
1070                         n = dev->ev_next;
1071
1072                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1073                 for (i = 0; i < n; i++) {
1074                         if (dev->event [i].type == GADGETFS_SETUP) {
1075                                 dev->state = STATE_DEV_SETUP;
1076                                 n = i + 1;
1077                                 break;
1078                         }
1079                 }
1080                 spin_unlock_irq (&dev->lock);
1081                 len = n * sizeof (struct usb_gadgetfs_event);
1082                 if (copy_to_user (buf, &dev->event, len))
1083                         retval = -EFAULT;
1084                 else
1085                         retval = len;
1086                 if (len > 0) {
1087                         /* NOTE this doesn't guard against broken drivers;
1088                          * concurrent ep0 readers may lose events.
1089                          */
1090                         spin_lock_irq (&dev->lock);
1091                         if (dev->ev_next > n) {
1092                                 memmove(&dev->event[0], &dev->event[n],
1093                                         sizeof (struct usb_gadgetfs_event)
1094                                                 * (dev->ev_next - n));
1095                         }
1096                         dev->ev_next -= n;
1097                         spin_unlock_irq (&dev->lock);
1098                 }
1099                 return retval;
1100         }
1101         if (fd->f_flags & O_NONBLOCK) {
1102                 retval = -EAGAIN;
1103                 goto done;
1104         }
1105
1106         switch (state) {
1107         default:
1108                 DBG (dev, "fail %s, state %d\n", __func__, state);
1109                 retval = -ESRCH;
1110                 break;
1111         case STATE_DEV_UNCONNECTED:
1112         case STATE_DEV_CONNECTED:
1113                 spin_unlock_irq (&dev->lock);
1114                 DBG (dev, "%s wait\n", __func__);
1115
1116                 /* wait for events */
1117                 retval = wait_event_interruptible (dev->wait,
1118                                 dev->ev_next != 0);
1119                 if (retval < 0)
1120                         return retval;
1121                 spin_lock_irq (&dev->lock);
1122                 goto scan;
1123         }
1124
1125 done:
1126         spin_unlock_irq (&dev->lock);
1127         return retval;
1128 }
1129
1130 static struct usb_gadgetfs_event *
1131 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1132 {
1133         struct usb_gadgetfs_event       *event;
1134         unsigned                        i;
1135
1136         switch (type) {
1137         /* these events purge the queue */
1138         case GADGETFS_DISCONNECT:
1139                 if (dev->state == STATE_DEV_SETUP)
1140                         dev->setup_abort = 1;
1141                 // FALL THROUGH
1142         case GADGETFS_CONNECT:
1143                 dev->ev_next = 0;
1144                 break;
1145         case GADGETFS_SETUP:            /* previous request timed out */
1146         case GADGETFS_SUSPEND:          /* same effect */
1147                 /* these events can't be repeated */
1148                 for (i = 0; i != dev->ev_next; i++) {
1149                         if (dev->event [i].type != type)
1150                                 continue;
1151                         DBG(dev, "discard old event[%d] %d\n", i, type);
1152                         dev->ev_next--;
1153                         if (i == dev->ev_next)
1154                                 break;
1155                         /* indices start at zero, for simplicity */
1156                         memmove (&dev->event [i], &dev->event [i + 1],
1157                                 sizeof (struct usb_gadgetfs_event)
1158                                         * (dev->ev_next - i));
1159                 }
1160                 break;
1161         default:
1162                 BUG ();
1163         }
1164         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1165         event = &dev->event [dev->ev_next++];
1166         BUG_ON (dev->ev_next > N_EVENT);
1167         memset (event, 0, sizeof *event);
1168         event->type = type;
1169         return event;
1170 }
1171
1172 static ssize_t
1173 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1174 {
1175         struct dev_data         *dev = fd->private_data;
1176         ssize_t                 retval = -ESRCH;
1177
1178         spin_lock_irq (&dev->lock);
1179
1180         /* report fd mode change before acting on it */
1181         if (dev->setup_abort) {
1182                 dev->setup_abort = 0;
1183                 retval = -EIDRM;
1184
1185         /* data and/or status stage for control request */
1186         } else if (dev->state == STATE_DEV_SETUP) {
1187
1188                 /* IN DATA+STATUS caller makes len <= wLength */
1189                 if (dev->setup_in) {
1190                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1191                         if (retval == 0) {
1192                                 dev->state = STATE_DEV_CONNECTED;
1193                                 spin_unlock_irq (&dev->lock);
1194                                 if (copy_from_user (dev->req->buf, buf, len))
1195                                         retval = -EFAULT;
1196                                 else {
1197                                         if (len < dev->setup_wLength)
1198                                                 dev->req->zero = 1;
1199                                         retval = usb_ep_queue (
1200                                                 dev->gadget->ep0, dev->req,
1201                                                 GFP_KERNEL);
1202                                 }
1203                                 if (retval < 0) {
1204                                         spin_lock_irq (&dev->lock);
1205                                         clean_req (dev->gadget->ep0, dev->req);
1206                                         spin_unlock_irq (&dev->lock);
1207                                 } else
1208                                         retval = len;
1209
1210                                 return retval;
1211                         }
1212
1213                 /* can stall some OUT transfers */
1214                 } else if (dev->setup_can_stall) {
1215                         VDEBUG(dev, "ep0out stall\n");
1216                         (void) usb_ep_set_halt (dev->gadget->ep0);
1217                         retval = -EL2HLT;
1218                         dev->state = STATE_DEV_CONNECTED;
1219                 } else {
1220                         DBG(dev, "bogus ep0out stall!\n");
1221                 }
1222         } else
1223                 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1224
1225         spin_unlock_irq (&dev->lock);
1226         return retval;
1227 }
1228
1229 static int
1230 ep0_fasync (int f, struct file *fd, int on)
1231 {
1232         struct dev_data         *dev = fd->private_data;
1233         // caller must F_SETOWN before signal delivery happens
1234         VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1235         return fasync_helper (f, fd, on, &dev->fasync);
1236 }
1237
1238 static struct usb_gadget_driver gadgetfs_driver;
1239
1240 static int
1241 dev_release (struct inode *inode, struct file *fd)
1242 {
1243         struct dev_data         *dev = fd->private_data;
1244
1245         /* closing ep0 === shutdown all */
1246
1247         usb_gadget_unregister_driver (&gadgetfs_driver);
1248
1249         /* at this point "good" hardware has disconnected the
1250          * device from USB; the host won't see it any more.
1251          * alternatively, all host requests will time out.
1252          */
1253
1254         fasync_helper (-1, fd, 0, &dev->fasync);
1255         kfree (dev->buf);
1256         dev->buf = NULL;
1257         put_dev (dev);
1258
1259         /* other endpoints were all decoupled from this device */
1260         spin_lock_irq(&dev->lock);
1261         dev->state = STATE_DEV_DISABLED;
1262         spin_unlock_irq(&dev->lock);
1263         return 0;
1264 }
1265
1266 static unsigned int
1267 ep0_poll (struct file *fd, poll_table *wait)
1268 {
1269        struct dev_data         *dev = fd->private_data;
1270        int                     mask = 0;
1271
1272        poll_wait(fd, &dev->wait, wait);
1273
1274        spin_lock_irq (&dev->lock);
1275
1276        /* report fd mode change before acting on it */
1277        if (dev->setup_abort) {
1278                dev->setup_abort = 0;
1279                mask = POLLHUP;
1280                goto out;
1281        }
1282
1283        if (dev->state == STATE_DEV_SETUP) {
1284                if (dev->setup_in || dev->setup_can_stall)
1285                        mask = POLLOUT;
1286        } else {
1287                if (dev->ev_next != 0)
1288                        mask = POLLIN;
1289        }
1290 out:
1291        spin_unlock_irq(&dev->lock);
1292        return mask;
1293 }
1294
1295 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1296 {
1297         struct dev_data         *dev = fd->private_data;
1298         struct usb_gadget       *gadget = dev->gadget;
1299         long ret = -ENOTTY;
1300
1301         if (gadget->ops->ioctl) {
1302                 lock_kernel();
1303                 ret = gadget->ops->ioctl (gadget, code, value);
1304                 unlock_kernel();
1305         }
1306         return ret;
1307 }
1308
1309 /* used after device configuration */
1310 static const struct file_operations ep0_io_operations = {
1311         .owner =        THIS_MODULE,
1312         .llseek =       no_llseek,
1313
1314         .read =         ep0_read,
1315         .write =        ep0_write,
1316         .fasync =       ep0_fasync,
1317         .poll =         ep0_poll,
1318         .unlocked_ioctl =       dev_ioctl,
1319         .release =      dev_release,
1320 };
1321
1322 /*----------------------------------------------------------------------*/
1323
1324 /* The in-kernel gadget driver handles most ep0 issues, in particular
1325  * enumerating the single configuration (as provided from user space).
1326  *
1327  * Unrecognized ep0 requests may be handled in user space.
1328  */
1329
1330 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1331 static void make_qualifier (struct dev_data *dev)
1332 {
1333         struct usb_qualifier_descriptor         qual;
1334         struct usb_device_descriptor            *desc;
1335
1336         qual.bLength = sizeof qual;
1337         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1338         qual.bcdUSB = __constant_cpu_to_le16 (0x0200);
1339
1340         desc = dev->dev;
1341         qual.bDeviceClass = desc->bDeviceClass;
1342         qual.bDeviceSubClass = desc->bDeviceSubClass;
1343         qual.bDeviceProtocol = desc->bDeviceProtocol;
1344
1345         /* assumes ep0 uses the same value for both speeds ... */
1346         qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
1347
1348         qual.bNumConfigurations = 1;
1349         qual.bRESERVED = 0;
1350
1351         memcpy (dev->rbuf, &qual, sizeof qual);
1352 }
1353 #endif
1354
1355 static int
1356 config_buf (struct dev_data *dev, u8 type, unsigned index)
1357 {
1358         int             len;
1359         int             hs = 0;
1360
1361         /* only one configuration */
1362         if (index > 0)
1363                 return -EINVAL;
1364
1365         if (gadget_is_dualspeed(dev->gadget)) {
1366                 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1367                 if (type == USB_DT_OTHER_SPEED_CONFIG)
1368                         hs = !hs;
1369         }
1370         if (hs) {
1371                 dev->req->buf = dev->hs_config;
1372                 len = le16_to_cpu(dev->hs_config->wTotalLength);
1373         } else {
1374                 dev->req->buf = dev->config;
1375                 len = le16_to_cpu(dev->config->wTotalLength);
1376         }
1377         ((u8 *)dev->req->buf) [1] = type;
1378         return len;
1379 }
1380
1381 static int
1382 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1383 {
1384         struct dev_data                 *dev = get_gadget_data (gadget);
1385         struct usb_request              *req = dev->req;
1386         int                             value = -EOPNOTSUPP;
1387         struct usb_gadgetfs_event       *event;
1388         u16                             w_value = le16_to_cpu(ctrl->wValue);
1389         u16                             w_length = le16_to_cpu(ctrl->wLength);
1390
1391         spin_lock (&dev->lock);
1392         dev->setup_abort = 0;
1393         if (dev->state == STATE_DEV_UNCONNECTED) {
1394                 if (gadget_is_dualspeed(gadget)
1395                                 && gadget->speed == USB_SPEED_HIGH
1396                                 && dev->hs_config == NULL) {
1397                         spin_unlock(&dev->lock);
1398                         ERROR (dev, "no high speed config??\n");
1399                         return -EINVAL;
1400                 }
1401
1402                 dev->state = STATE_DEV_CONNECTED;
1403                 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1404
1405                 INFO (dev, "connected\n");
1406                 event = next_event (dev, GADGETFS_CONNECT);
1407                 event->u.speed = gadget->speed;
1408                 ep0_readable (dev);
1409
1410         /* host may have given up waiting for response.  we can miss control
1411          * requests handled lower down (device/endpoint status and features);
1412          * then ep0_{read,write} will report the wrong status. controller
1413          * driver will have aborted pending i/o.
1414          */
1415         } else if (dev->state == STATE_DEV_SETUP)
1416                 dev->setup_abort = 1;
1417
1418         req->buf = dev->rbuf;
1419         req->dma = DMA_ADDR_INVALID;
1420         req->context = NULL;
1421         value = -EOPNOTSUPP;
1422         switch (ctrl->bRequest) {
1423
1424         case USB_REQ_GET_DESCRIPTOR:
1425                 if (ctrl->bRequestType != USB_DIR_IN)
1426                         goto unrecognized;
1427                 switch (w_value >> 8) {
1428
1429                 case USB_DT_DEVICE:
1430                         value = min (w_length, (u16) sizeof *dev->dev);
1431                         req->buf = dev->dev;
1432                         break;
1433 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1434                 case USB_DT_DEVICE_QUALIFIER:
1435                         if (!dev->hs_config)
1436                                 break;
1437                         value = min (w_length, (u16)
1438                                 sizeof (struct usb_qualifier_descriptor));
1439                         make_qualifier (dev);
1440                         break;
1441                 case USB_DT_OTHER_SPEED_CONFIG:
1442                         // FALLTHROUGH
1443 #endif
1444                 case USB_DT_CONFIG:
1445                         value = config_buf (dev,
1446                                         w_value >> 8,
1447                                         w_value & 0xff);
1448                         if (value >= 0)
1449                                 value = min (w_length, (u16) value);
1450                         break;
1451                 case USB_DT_STRING:
1452                         goto unrecognized;
1453
1454                 default:                // all others are errors
1455                         break;
1456                 }
1457                 break;
1458
1459         /* currently one config, two speeds */
1460         case USB_REQ_SET_CONFIGURATION:
1461                 if (ctrl->bRequestType != 0)
1462                         goto unrecognized;
1463                 if (0 == (u8) w_value) {
1464                         value = 0;
1465                         dev->current_config = 0;
1466                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1467                         // user mode expected to disable endpoints
1468                 } else {
1469                         u8      config, power;
1470
1471                         if (gadget_is_dualspeed(gadget)
1472                                         && gadget->speed == USB_SPEED_HIGH) {
1473                                 config = dev->hs_config->bConfigurationValue;
1474                                 power = dev->hs_config->bMaxPower;
1475                         } else {
1476                                 config = dev->config->bConfigurationValue;
1477                                 power = dev->config->bMaxPower;
1478                         }
1479
1480                         if (config == (u8) w_value) {
1481                                 value = 0;
1482                                 dev->current_config = config;
1483                                 usb_gadget_vbus_draw(gadget, 2 * power);
1484                         }
1485                 }
1486
1487                 /* report SET_CONFIGURATION like any other control request,
1488                  * except that usermode may not stall this.  the next
1489                  * request mustn't be allowed start until this finishes:
1490                  * endpoints and threads set up, etc.
1491                  *
1492                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1493                  * has bad/racey automagic that prevents synchronizing here.
1494                  * even kernel mode drivers often miss them.
1495                  */
1496                 if (value == 0) {
1497                         INFO (dev, "configuration #%d\n", dev->current_config);
1498                         if (dev->usermode_setup) {
1499                                 dev->setup_can_stall = 0;
1500                                 goto delegate;
1501                         }
1502                 }
1503                 break;
1504
1505 #ifndef CONFIG_USB_GADGET_PXA25X
1506         /* PXA automagically handles this request too */
1507         case USB_REQ_GET_CONFIGURATION:
1508                 if (ctrl->bRequestType != 0x80)
1509                         goto unrecognized;
1510                 *(u8 *)req->buf = dev->current_config;
1511                 value = min (w_length, (u16) 1);
1512                 break;
1513 #endif
1514
1515         default:
1516 unrecognized:
1517                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1518                         dev->usermode_setup ? "delegate" : "fail",
1519                         ctrl->bRequestType, ctrl->bRequest,
1520                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1521
1522                 /* if there's an ep0 reader, don't stall */
1523                 if (dev->usermode_setup) {
1524                         dev->setup_can_stall = 1;
1525 delegate:
1526                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1527                                                 ? 1 : 0;
1528                         dev->setup_wLength = w_length;
1529                         dev->setup_out_ready = 0;
1530                         dev->setup_out_error = 0;
1531                         value = 0;
1532
1533                         /* read DATA stage for OUT right away */
1534                         if (unlikely (!dev->setup_in && w_length)) {
1535                                 value = setup_req (gadget->ep0, dev->req,
1536                                                         w_length);
1537                                 if (value < 0)
1538                                         break;
1539                                 value = usb_ep_queue (gadget->ep0, dev->req,
1540                                                         GFP_ATOMIC);
1541                                 if (value < 0) {
1542                                         clean_req (gadget->ep0, dev->req);
1543                                         break;
1544                                 }
1545
1546                                 /* we can't currently stall these */
1547                                 dev->setup_can_stall = 0;
1548                         }
1549
1550                         /* state changes when reader collects event */
1551                         event = next_event (dev, GADGETFS_SETUP);
1552                         event->u.setup = *ctrl;
1553                         ep0_readable (dev);
1554                         spin_unlock (&dev->lock);
1555                         return 0;
1556                 }
1557         }
1558
1559         /* proceed with data transfer and status phases? */
1560         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1561                 req->length = value;
1562                 req->zero = value < w_length;
1563                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1564                 if (value < 0) {
1565                         DBG (dev, "ep_queue --> %d\n", value);
1566                         req->status = 0;
1567                 }
1568         }
1569
1570         /* device stalls when value < 0 */
1571         spin_unlock (&dev->lock);
1572         return value;
1573 }
1574
1575 static void destroy_ep_files (struct dev_data *dev)
1576 {
1577         struct list_head        *entry, *tmp;
1578
1579         DBG (dev, "%s %d\n", __func__, dev->state);
1580
1581         /* dev->state must prevent interference */
1582 restart:
1583         spin_lock_irq (&dev->lock);
1584         list_for_each_safe (entry, tmp, &dev->epfiles) {
1585                 struct ep_data  *ep;
1586                 struct inode    *parent;
1587                 struct dentry   *dentry;
1588
1589                 /* break link to FS */
1590                 ep = list_entry (entry, struct ep_data, epfiles);
1591                 list_del_init (&ep->epfiles);
1592                 dentry = ep->dentry;
1593                 ep->dentry = NULL;
1594                 parent = dentry->d_parent->d_inode;
1595
1596                 /* break link to controller */
1597                 if (ep->state == STATE_EP_ENABLED)
1598                         (void) usb_ep_disable (ep->ep);
1599                 ep->state = STATE_EP_UNBOUND;
1600                 usb_ep_free_request (ep->ep, ep->req);
1601                 ep->ep = NULL;
1602                 wake_up (&ep->wait);
1603                 put_ep (ep);
1604
1605                 spin_unlock_irq (&dev->lock);
1606
1607                 /* break link to dcache */
1608                 mutex_lock (&parent->i_mutex);
1609                 d_delete (dentry);
1610                 dput (dentry);
1611                 mutex_unlock (&parent->i_mutex);
1612
1613                 /* fds may still be open */
1614                 goto restart;
1615         }
1616         spin_unlock_irq (&dev->lock);
1617 }
1618
1619
1620 static struct inode *
1621 gadgetfs_create_file (struct super_block *sb, char const *name,
1622                 void *data, const struct file_operations *fops,
1623                 struct dentry **dentry_p);
1624
1625 static int activate_ep_files (struct dev_data *dev)
1626 {
1627         struct usb_ep   *ep;
1628         struct ep_data  *data;
1629
1630         gadget_for_each_ep (ep, dev->gadget) {
1631
1632                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1633                 if (!data)
1634                         goto enomem0;
1635                 data->state = STATE_EP_DISABLED;
1636                 init_MUTEX (&data->lock);
1637                 init_waitqueue_head (&data->wait);
1638
1639                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1640                 atomic_set (&data->count, 1);
1641                 data->dev = dev;
1642                 get_dev (dev);
1643
1644                 data->ep = ep;
1645                 ep->driver_data = data;
1646
1647                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1648                 if (!data->req)
1649                         goto enomem1;
1650
1651                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1652                                 data, &ep_config_operations,
1653                                 &data->dentry);
1654                 if (!data->inode)
1655                         goto enomem2;
1656                 list_add_tail (&data->epfiles, &dev->epfiles);
1657         }
1658         return 0;
1659
1660 enomem2:
1661         usb_ep_free_request (ep, data->req);
1662 enomem1:
1663         put_dev (dev);
1664         kfree (data);
1665 enomem0:
1666         DBG (dev, "%s enomem\n", __func__);
1667         destroy_ep_files (dev);
1668         return -ENOMEM;
1669 }
1670
1671 static void
1672 gadgetfs_unbind (struct usb_gadget *gadget)
1673 {
1674         struct dev_data         *dev = get_gadget_data (gadget);
1675
1676         DBG (dev, "%s\n", __func__);
1677
1678         spin_lock_irq (&dev->lock);
1679         dev->state = STATE_DEV_UNBOUND;
1680         spin_unlock_irq (&dev->lock);
1681
1682         destroy_ep_files (dev);
1683         gadget->ep0->driver_data = NULL;
1684         set_gadget_data (gadget, NULL);
1685
1686         /* we've already been disconnected ... no i/o is active */
1687         if (dev->req)
1688                 usb_ep_free_request (gadget->ep0, dev->req);
1689         DBG (dev, "%s done\n", __func__);
1690         put_dev (dev);
1691 }
1692
1693 static struct dev_data          *the_device;
1694
1695 static int
1696 gadgetfs_bind (struct usb_gadget *gadget)
1697 {
1698         struct dev_data         *dev = the_device;
1699
1700         if (!dev)
1701                 return -ESRCH;
1702         if (0 != strcmp (CHIP, gadget->name)) {
1703                 pr_err("%s expected %s controller not %s\n",
1704                         shortname, CHIP, gadget->name);
1705                 return -ENODEV;
1706         }
1707
1708         set_gadget_data (gadget, dev);
1709         dev->gadget = gadget;
1710         gadget->ep0->driver_data = dev;
1711         dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1712
1713         /* preallocate control response and buffer */
1714         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1715         if (!dev->req)
1716                 goto enomem;
1717         dev->req->context = NULL;
1718         dev->req->complete = epio_complete;
1719
1720         if (activate_ep_files (dev) < 0)
1721                 goto enomem;
1722
1723         INFO (dev, "bound to %s driver\n", gadget->name);
1724         spin_lock_irq(&dev->lock);
1725         dev->state = STATE_DEV_UNCONNECTED;
1726         spin_unlock_irq(&dev->lock);
1727         get_dev (dev);
1728         return 0;
1729
1730 enomem:
1731         gadgetfs_unbind (gadget);
1732         return -ENOMEM;
1733 }
1734
1735 static void
1736 gadgetfs_disconnect (struct usb_gadget *gadget)
1737 {
1738         struct dev_data         *dev = get_gadget_data (gadget);
1739
1740         spin_lock (&dev->lock);
1741         if (dev->state == STATE_DEV_UNCONNECTED)
1742                 goto exit;
1743         dev->state = STATE_DEV_UNCONNECTED;
1744
1745         INFO (dev, "disconnected\n");
1746         next_event (dev, GADGETFS_DISCONNECT);
1747         ep0_readable (dev);
1748 exit:
1749         spin_unlock (&dev->lock);
1750 }
1751
1752 static void
1753 gadgetfs_suspend (struct usb_gadget *gadget)
1754 {
1755         struct dev_data         *dev = get_gadget_data (gadget);
1756
1757         INFO (dev, "suspended from state %d\n", dev->state);
1758         spin_lock (&dev->lock);
1759         switch (dev->state) {
1760         case STATE_DEV_SETUP:           // VERY odd... host died??
1761         case STATE_DEV_CONNECTED:
1762         case STATE_DEV_UNCONNECTED:
1763                 next_event (dev, GADGETFS_SUSPEND);
1764                 ep0_readable (dev);
1765                 /* FALLTHROUGH */
1766         default:
1767                 break;
1768         }
1769         spin_unlock (&dev->lock);
1770 }
1771
1772 static struct usb_gadget_driver gadgetfs_driver = {
1773 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1774         .speed          = USB_SPEED_HIGH,
1775 #else
1776         .speed          = USB_SPEED_FULL,
1777 #endif
1778         .function       = (char *) driver_desc,
1779         .bind           = gadgetfs_bind,
1780         .unbind         = gadgetfs_unbind,
1781         .setup          = gadgetfs_setup,
1782         .disconnect     = gadgetfs_disconnect,
1783         .suspend        = gadgetfs_suspend,
1784
1785         .driver = {
1786                 .name           = (char *) shortname,
1787         },
1788 };
1789
1790 /*----------------------------------------------------------------------*/
1791
1792 static void gadgetfs_nop(struct usb_gadget *arg) { }
1793
1794 static int gadgetfs_probe (struct usb_gadget *gadget)
1795 {
1796         CHIP = gadget->name;
1797         return -EISNAM;
1798 }
1799
1800 static struct usb_gadget_driver probe_driver = {
1801         .speed          = USB_SPEED_HIGH,
1802         .bind           = gadgetfs_probe,
1803         .unbind         = gadgetfs_nop,
1804         .setup          = (void *)gadgetfs_nop,
1805         .disconnect     = gadgetfs_nop,
1806         .driver = {
1807                 .name           = "nop",
1808         },
1809 };
1810
1811
1812 /* DEVICE INITIALIZATION
1813  *
1814  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1815  *     status = write (fd, descriptors, sizeof descriptors)
1816  *
1817  * That write establishes the device configuration, so the kernel can
1818  * bind to the controller ... guaranteeing it can handle enumeration
1819  * at all necessary speeds.  Descriptor order is:
1820  *
1821  * . message tag (u32, host order) ... for now, must be zero; it
1822  *      would change to support features like multi-config devices
1823  * . full/low speed config ... all wTotalLength bytes (with interface,
1824  *      class, altsetting, endpoint, and other descriptors)
1825  * . high speed config ... all descriptors, for high speed operation;
1826  *      this one's optional except for high-speed hardware
1827  * . device descriptor
1828  *
1829  * Endpoints are not yet enabled. Drivers must wait until device
1830  * configuration and interface altsetting changes create
1831  * the need to configure (or unconfigure) them.
1832  *
1833  * After initialization, the device stays active for as long as that
1834  * $CHIP file is open.  Events must then be read from that descriptor,
1835  * such as configuration notifications.
1836  */
1837
1838 static int is_valid_config (struct usb_config_descriptor *config)
1839 {
1840         return config->bDescriptorType == USB_DT_CONFIG
1841                 && config->bLength == USB_DT_CONFIG_SIZE
1842                 && config->bConfigurationValue != 0
1843                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1844                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1845         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1846         /* FIXME check lengths: walk to end */
1847 }
1848
1849 static ssize_t
1850 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1851 {
1852         struct dev_data         *dev = fd->private_data;
1853         ssize_t                 value = len, length = len;
1854         unsigned                total;
1855         u32                     tag;
1856         char                    *kbuf;
1857
1858         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1859                 return -EINVAL;
1860
1861         /* we might need to change message format someday */
1862         if (copy_from_user (&tag, buf, 4))
1863                 return -EFAULT;
1864         if (tag != 0)
1865                 return -EINVAL;
1866         buf += 4;
1867         length -= 4;
1868
1869         kbuf = kmalloc (length, GFP_KERNEL);
1870         if (!kbuf)
1871                 return -ENOMEM;
1872         if (copy_from_user (kbuf, buf, length)) {
1873                 kfree (kbuf);
1874                 return -EFAULT;
1875         }
1876
1877         spin_lock_irq (&dev->lock);
1878         value = -EINVAL;
1879         if (dev->buf)
1880                 goto fail;
1881         dev->buf = kbuf;
1882
1883         /* full or low speed config */
1884         dev->config = (void *) kbuf;
1885         total = le16_to_cpu(dev->config->wTotalLength);
1886         if (!is_valid_config (dev->config) || total >= length)
1887                 goto fail;
1888         kbuf += total;
1889         length -= total;
1890
1891         /* optional high speed config */
1892         if (kbuf [1] == USB_DT_CONFIG) {
1893                 dev->hs_config = (void *) kbuf;
1894                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1895                 if (!is_valid_config (dev->hs_config) || total >= length)
1896                         goto fail;
1897                 kbuf += total;
1898                 length -= total;
1899         }
1900
1901         /* could support multiple configs, using another encoding! */
1902
1903         /* device descriptor (tweaked for paranoia) */
1904         if (length != USB_DT_DEVICE_SIZE)
1905                 goto fail;
1906         dev->dev = (void *)kbuf;
1907         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1908                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1909                         || dev->dev->bNumConfigurations != 1)
1910                 goto fail;
1911         dev->dev->bNumConfigurations = 1;
1912         dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200);
1913
1914         /* triggers gadgetfs_bind(); then we can enumerate. */
1915         spin_unlock_irq (&dev->lock);
1916         value = usb_gadget_register_driver (&gadgetfs_driver);
1917         if (value != 0) {
1918                 kfree (dev->buf);
1919                 dev->buf = NULL;
1920         } else {
1921                 /* at this point "good" hardware has for the first time
1922                  * let the USB the host see us.  alternatively, if users
1923                  * unplug/replug that will clear all the error state.
1924                  *
1925                  * note:  everything running before here was guaranteed
1926                  * to choke driver model style diagnostics.  from here
1927                  * on, they can work ... except in cleanup paths that
1928                  * kick in after the ep0 descriptor is closed.
1929                  */
1930                 fd->f_op = &ep0_io_operations;
1931                 value = len;
1932         }
1933         return value;
1934
1935 fail:
1936         spin_unlock_irq (&dev->lock);
1937         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1938         kfree (dev->buf);
1939         dev->buf = NULL;
1940         return value;
1941 }
1942
1943 static int
1944 dev_open (struct inode *inode, struct file *fd)
1945 {
1946         struct dev_data         *dev = inode->i_private;
1947         int                     value = -EBUSY;
1948
1949         spin_lock_irq(&dev->lock);
1950         if (dev->state == STATE_DEV_DISABLED) {
1951                 dev->ev_next = 0;
1952                 dev->state = STATE_DEV_OPENED;
1953                 fd->private_data = dev;
1954                 get_dev (dev);
1955                 value = 0;
1956         }
1957         spin_unlock_irq(&dev->lock);
1958         return value;
1959 }
1960
1961 static const struct file_operations dev_init_operations = {
1962         .owner =        THIS_MODULE,
1963         .llseek =       no_llseek,
1964
1965         .open =         dev_open,
1966         .write =        dev_config,
1967         .fasync =       ep0_fasync,
1968         .unlocked_ioctl = dev_ioctl,
1969         .release =      dev_release,
1970 };
1971
1972 /*----------------------------------------------------------------------*/
1973
1974 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1975  *
1976  * Mounting the filesystem creates a controller file, used first for
1977  * device configuration then later for event monitoring.
1978  */
1979
1980
1981 /* FIXME PAM etc could set this security policy without mount options
1982  * if epfiles inherited ownership and permissons from ep0 ...
1983  */
1984
1985 static unsigned default_uid;
1986 static unsigned default_gid;
1987 static unsigned default_perm = S_IRUSR | S_IWUSR;
1988
1989 module_param (default_uid, uint, 0644);
1990 module_param (default_gid, uint, 0644);
1991 module_param (default_perm, uint, 0644);
1992
1993
1994 static struct inode *
1995 gadgetfs_make_inode (struct super_block *sb,
1996                 void *data, const struct file_operations *fops,
1997                 int mode)
1998 {
1999         struct inode *inode = new_inode (sb);
2000
2001         if (inode) {
2002                 inode->i_mode = mode;
2003                 inode->i_uid = default_uid;
2004                 inode->i_gid = default_gid;
2005                 inode->i_blocks = 0;
2006                 inode->i_atime = inode->i_mtime = inode->i_ctime
2007                                 = CURRENT_TIME;
2008                 inode->i_private = data;
2009                 inode->i_fop = fops;
2010         }
2011         return inode;
2012 }
2013
2014 /* creates in fs root directory, so non-renamable and non-linkable.
2015  * so inode and dentry are paired, until device reconfig.
2016  */
2017 static struct inode *
2018 gadgetfs_create_file (struct super_block *sb, char const *name,
2019                 void *data, const struct file_operations *fops,
2020                 struct dentry **dentry_p)
2021 {
2022         struct dentry   *dentry;
2023         struct inode    *inode;
2024
2025         dentry = d_alloc_name(sb->s_root, name);
2026         if (!dentry)
2027                 return NULL;
2028
2029         inode = gadgetfs_make_inode (sb, data, fops,
2030                         S_IFREG | (default_perm & S_IRWXUGO));
2031         if (!inode) {
2032                 dput(dentry);
2033                 return NULL;
2034         }
2035         d_add (dentry, inode);
2036         *dentry_p = dentry;
2037         return inode;
2038 }
2039
2040 static struct super_operations gadget_fs_operations = {
2041         .statfs =       simple_statfs,
2042         .drop_inode =   generic_delete_inode,
2043 };
2044
2045 static int
2046 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2047 {
2048         struct inode    *inode;
2049         struct dentry   *d;
2050         struct dev_data *dev;
2051
2052         if (the_device)
2053                 return -ESRCH;
2054
2055         /* fake probe to determine $CHIP */
2056         (void) usb_gadget_register_driver (&probe_driver);
2057         if (!CHIP)
2058                 return -ENODEV;
2059
2060         /* superblock */
2061         sb->s_blocksize = PAGE_CACHE_SIZE;
2062         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2063         sb->s_magic = GADGETFS_MAGIC;
2064         sb->s_op = &gadget_fs_operations;
2065         sb->s_time_gran = 1;
2066
2067         /* root inode */
2068         inode = gadgetfs_make_inode (sb,
2069                         NULL, &simple_dir_operations,
2070                         S_IFDIR | S_IRUGO | S_IXUGO);
2071         if (!inode)
2072                 goto enomem0;
2073         inode->i_op = &simple_dir_inode_operations;
2074         if (!(d = d_alloc_root (inode)))
2075                 goto enomem1;
2076         sb->s_root = d;
2077
2078         /* the ep0 file is named after the controller we expect;
2079          * user mode code can use it for sanity checks, like we do.
2080          */
2081         dev = dev_new ();
2082         if (!dev)
2083                 goto enomem2;
2084
2085         dev->sb = sb;
2086         if (!gadgetfs_create_file (sb, CHIP,
2087                                 dev, &dev_init_operations,
2088                                 &dev->dentry))
2089                 goto enomem3;
2090
2091         /* other endpoint files are available after hardware setup,
2092          * from binding to a controller.
2093          */
2094         the_device = dev;
2095         return 0;
2096
2097 enomem3:
2098         put_dev (dev);
2099 enomem2:
2100         dput (d);
2101 enomem1:
2102         iput (inode);
2103 enomem0:
2104         return -ENOMEM;
2105 }
2106
2107 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2108 static int
2109 gadgetfs_get_sb (struct file_system_type *t, int flags,
2110                 const char *path, void *opts, struct vfsmount *mnt)
2111 {
2112         return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt);
2113 }
2114
2115 static void
2116 gadgetfs_kill_sb (struct super_block *sb)
2117 {
2118         kill_litter_super (sb);
2119         if (the_device) {
2120                 put_dev (the_device);
2121                 the_device = NULL;
2122         }
2123 }
2124
2125 /*----------------------------------------------------------------------*/
2126
2127 static struct file_system_type gadgetfs_type = {
2128         .owner          = THIS_MODULE,
2129         .name           = shortname,
2130         .get_sb         = gadgetfs_get_sb,
2131         .kill_sb        = gadgetfs_kill_sb,
2132 };
2133
2134 /*----------------------------------------------------------------------*/
2135
2136 static int __init init (void)
2137 {
2138         int status;
2139
2140         status = register_filesystem (&gadgetfs_type);
2141         if (status == 0)
2142                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2143                         shortname, driver_desc);
2144         return status;
2145 }
2146 module_init (init);
2147
2148 static void __exit cleanup (void)
2149 {
2150         pr_debug ("unregister %s\n", shortname);
2151         unregister_filesystem (&gadgetfs_type);
2152 }
2153 module_exit (cleanup);
2154