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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      DEBUG                   /* data to help fault diagnosis */
  24 // #define      VERBOSE         /* extra debug messages (success too) */
  25
  26 #include <linux/init.h>
  27 #include <linux/module.h>
  28 #include <linux/fs.h>
  29 #include <linux/pagemap.h>
  30 #include <linux/uts.h>
  31 #include <linux/wait.h>
  32 #include <linux/compiler.h>
  33 #include <asm/uaccess.h>
  34 #include <linux/slab.h>
  35 #include <linux/poll.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
 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 WARN(dev,fmt,args...) \
 266         xprintk(dev , KERN_WARNING , fmt , ## args)
 267 #define INFO(dev,fmt,args...) \
 268         xprintk(dev , KERN_INFO , fmt , ## args)
 269
 270
 271 /*----------------------------------------------------------------------*/
 272
 273 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 274  *
 275  * After opening, configure non-control endpoints.  Then use normal
 276  * stream read() and write() requests; and maybe ioctl() to get more
 277  * precise FIFO status when recovering from cancellation.
 278  */
 279
 280 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 281 {
 282         struct ep_data  *epdata = ep->driver_data;
 283
 284         if (!req->context)
 285                 return;
 286         if (req->status)
 287                 epdata->status = req->status;
 288         else
 289                 epdata->status = req->actual;
 290         complete ((struct completion *)req->context);
 291 }
 292
 293 /* tasklock endpoint, returning when it's connected.
 294  * still need dev->lock to use epdata->ep.
 295  */
 296 static int
 297 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
 298 {
 299         int     val;
 300
 301         if (f_flags & O_NONBLOCK) {
 302                 if (down_trylock (&epdata->lock) != 0)
 303                         goto nonblock;
 304                 if (epdata->state != STATE_EP_ENABLED) {
 305                         up (&epdata->lock);
 306 nonblock:
 307                         val = -EAGAIN;
 308                 } else
 309                         val = 0;
 310                 return val;
 311         }
 312
 313         if ((val = down_interruptible (&epdata->lock)) < 0)
 314                 return val;
 315
 316         switch (epdata->state) {
 317         case STATE_EP_ENABLED:
 318                 break;
 319         // case STATE_EP_DISABLED:              /* "can't happen" */
 320         // case STATE_EP_READY:                 /* "can't happen" */
 321         default:                                /* error! */
 322                 pr_debug ("%s: ep %p not available, state %d\n",
 323                                 shortname, epdata, epdata->state);
 324                 // FALLTHROUGH
 325         case STATE_EP_UNBOUND:                  /* clean disconnect */
 326                 val = -ENODEV;
 327                 up (&epdata->lock);
 328         }
 329         return val;
 330 }
 331
 332 static ssize_t
 333 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 334 {
 335         DECLARE_COMPLETION_ONSTACK (done);
 336         int value;
 337
 338         spin_lock_irq (&epdata->dev->lock);
 339         if (likely (epdata->ep != NULL)) {
 340                 struct usb_request      *req = epdata->req;
 341
 342                 req->context = &done;
 343                 req->complete = epio_complete;
 344                 req->buf = buf;
 345                 req->length = len;
 346                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 347         } else
 348                 value = -ENODEV;
 349         spin_unlock_irq (&epdata->dev->lock);
 350
 351         if (likely (value == 0)) {
 352                 value = wait_event_interruptible (done.wait, done.done);
 353                 if (value != 0) {
 354                         spin_lock_irq (&epdata->dev->lock);
 355                         if (likely (epdata->ep != NULL)) {
 356                                 DBG (epdata->dev, "%s i/o interrupted\n",
 357                                                 epdata->name);
 358                                 usb_ep_dequeue (epdata->ep, epdata->req);
 359                                 spin_unlock_irq (&epdata->dev->lock);
 360
 361                                 wait_event (done.wait, done.done);
 362                                 if (epdata->status == -ECONNRESET)
 363                                         epdata->status = -EINTR;
 364                         } else {
 365                                 spin_unlock_irq (&epdata->dev->lock);
 366
 367                                 DBG (epdata->dev, "endpoint gone\n");
 368                                 epdata->status = -ENODEV;
 369                         }
 370                 }
 371                 return epdata->status;
 372         }
 373         return value;
 374 }
 375
 376
 377 /* handle a synchronous OUT bulk/intr/iso transfer */
 378 static ssize_t
 379 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 380 {
 381         struct ep_data          *data = fd->private_data;
 382         void                    *kbuf;
 383         ssize_t                 value;
 384
 385         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 386                 return value;
 387
 388         /* halt any endpoint by doing a "wrong direction" i/o call */
 389         if (data->desc.bEndpointAddress & USB_DIR_IN) {
 390                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 391                                 == USB_ENDPOINT_XFER_ISOC)
 392                         return -EINVAL;
 393                 DBG (data->dev, "%s halt\n", data->name);
 394                 spin_lock_irq (&data->dev->lock);
 395                 if (likely (data->ep != NULL))
 396                         usb_ep_set_halt (data->ep);
 397                 spin_unlock_irq (&data->dev->lock);
 398                 up (&data->lock);
 399                 return -EBADMSG;
 400         }
 401
 402         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
 403
 404         value = -ENOMEM;
 405         kbuf = kmalloc (len, GFP_KERNEL);
 406         if (unlikely (!kbuf))
 407                 goto free1;
 408
 409         value = ep_io (data, kbuf, len);
 410         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
 411                 data->name, len, (int) value);
 412         if (value >= 0 && copy_to_user (buf, kbuf, value))
 413                 value = -EFAULT;
 414
 415 free1:
 416         up (&data->lock);
 417         kfree (kbuf);
 418         return value;
 419 }
 420
 421 /* handle a synchronous IN bulk/intr/iso transfer */
 422 static ssize_t
 423 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 424 {
 425         struct ep_data          *data = fd->private_data;
 426         void                    *kbuf;
 427         ssize_t                 value;
 428
 429         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 430                 return value;
 431
 432         /* halt any endpoint by doing a "wrong direction" i/o call */
 433         if (!(data->desc.bEndpointAddress & USB_DIR_IN)) {
 434                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 435                                 == USB_ENDPOINT_XFER_ISOC)
 436                         return -EINVAL;
 437                 DBG (data->dev, "%s halt\n", data->name);
 438                 spin_lock_irq (&data->dev->lock);
 439                 if (likely (data->ep != NULL))
 440                         usb_ep_set_halt (data->ep);
 441                 spin_unlock_irq (&data->dev->lock);
 442                 up (&data->lock);
 443                 return -EBADMSG;
 444         }
 445
 446         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
 447
 448         value = -ENOMEM;
 449         kbuf = kmalloc (len, GFP_KERNEL);
 450         if (!kbuf)
 451                 goto free1;
 452         if (copy_from_user (kbuf, buf, len)) {
 453                 value = -EFAULT;
 454                 goto free1;
 455         }
 456
 457         value = ep_io (data, kbuf, len);
 458         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
 459                 data->name, len, (int) value);
 460 free1:
 461         up (&data->lock);
 462         kfree (kbuf);
 463         return value;
 464 }
 465
 466 static int
 467 ep_release (struct inode *inode, struct file *fd)
 468 {
 469         struct ep_data          *data = fd->private_data;
 470         int value;
 471
 472         if ((value = down_interruptible(&data->lock)) < 0)
 473                 return value;
 474
 475         /* clean up if this can be reopened */
 476         if (data->state != STATE_EP_UNBOUND) {
 477                 data->state = STATE_EP_DISABLED;
 478                 data->desc.bDescriptorType = 0;
 479                 data->hs_desc.bDescriptorType = 0;
 480                 usb_ep_disable(data->ep);
 481         }
 482         up (&data->lock);
 483         put_ep (data);
 484         return 0;
 485 }
 486
 487 static int ep_ioctl (struct inode *inode, struct file *fd,
 488                 unsigned code, unsigned long value)
 489 {
 490         struct ep_data          *data = fd->private_data;
 491         int                     status;
 492
 493         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 494                 return status;
 495
 496         spin_lock_irq (&data->dev->lock);
 497         if (likely (data->ep != NULL)) {
 498                 switch (code) {
 499                 case GADGETFS_FIFO_STATUS:
 500                         status = usb_ep_fifo_status (data->ep);
 501                         break;
 502                 case GADGETFS_FIFO_FLUSH:
 503                         usb_ep_fifo_flush (data->ep);
 504                         break;
 505                 case GADGETFS_CLEAR_HALT:
 506                         status = usb_ep_clear_halt (data->ep);
 507                         break;
 508                 default:
 509                         status = -ENOTTY;
 510                 }
 511         } else
 512                 status = -ENODEV;
 513         spin_unlock_irq (&data->dev->lock);
 514         up (&data->lock);
 515         return status;
 516 }
 517
 518 /*----------------------------------------------------------------------*/
 519
 520 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 521
 522 struct kiocb_priv {
 523         struct usb_request      *req;
 524         struct ep_data          *epdata;
 525         void                    *buf;
 526         const struct iovec      *iv;
 527         unsigned long           nr_segs;
 528         unsigned                actual;
 529 };
 530
 531 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
 532 {
 533         struct kiocb_priv       *priv = iocb->private;
 534         struct ep_data          *epdata;
 535         int                     value;
 536
 537         local_irq_disable();
 538         epdata = priv->epdata;
 539         // spin_lock(&epdata->dev->lock);
 540         kiocbSetCancelled(iocb);
 541         if (likely(epdata && epdata->ep && priv->req))
 542                 value = usb_ep_dequeue (epdata->ep, priv->req);
 543         else
 544                 value = -EINVAL;
 545         // spin_unlock(&epdata->dev->lock);
 546         local_irq_enable();
 547
 548         aio_put_req(iocb);
 549         return value;
 550 }
 551
 552 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
 553 {
 554         struct kiocb_priv       *priv = iocb->private;
 555         ssize_t                 len, total;
 556         void                    *to_copy;
 557         int                     i;
 558
 559         /* we "retry" to get the right mm context for this: */
 560
 561         /* copy stuff into user buffers */
 562         total = priv->actual;
 563         len = 0;
 564         to_copy = priv->buf;
 565         for (i=0; i < priv->nr_segs; i++) {
 566                 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
 567
 568                 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
 569                         if (len == 0)
 570                                 len = -EFAULT;
 571                         break;
 572                 }
 573
 574                 total -= this;
 575                 len += this;
 576                 to_copy += this;
 577                 if (total == 0)
 578                         break;
 579         }
 580         kfree(priv->buf);
 581         kfree(priv);
 582         return len;
 583 }
 584
 585 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 586 {
 587         struct kiocb            *iocb = req->context;
 588         struct kiocb_priv       *priv = iocb->private;
 589         struct ep_data          *epdata = priv->epdata;
 590
 591         /* lock against disconnect (and ideally, cancel) */
 592         spin_lock(&epdata->dev->lock);
 593         priv->req = NULL;
 594         priv->epdata = NULL;
 595
 596         /* if this was a write or a read returning no data then we
 597          * don't need to copy anything to userspace, so we can
 598          * complete the aio request immediately.
 599          */
 600         if (priv->iv == NULL || unlikely(req->actual == 0)) {
 601                 kfree(req->buf);
 602                 kfree(priv);
 603                 iocb->private = NULL;
 604                 /* aio_complete() reports bytes-transferred _and_ faults */
 605                 aio_complete(iocb, req->actual ? req->actual : req->status,
 606                                 req->status);
 607         } else {
 608                 /* retry() won't report both; so we hide some faults */
 609                 if (unlikely(0 != req->status))
 610                         DBG(epdata->dev, "%s fault %d len %d\n",
 611                                 ep->name, req->status, req->actual);
 612
 613                 priv->buf = req->buf;
 614                 priv->actual = req->actual;
 615                 kick_iocb(iocb);
 616         }
 617         spin_unlock(&epdata->dev->lock);
 618
 619         usb_ep_free_request(ep, req);
 620         put_ep(epdata);
 621 }
 622
 623 static ssize_t
 624 ep_aio_rwtail(
 625         struct kiocb    *iocb,
 626         char            *buf,
 627         size_t          len,
 628         struct ep_data  *epdata,
 629         const struct iovec *iv,
 630         unsigned long   nr_segs
 631 )
 632 {
 633         struct kiocb_priv       *priv;
 634         struct usb_request      *req;
 635         ssize_t                 value;
 636
 637         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 638         if (!priv) {
 639                 value = -ENOMEM;
 640 fail:
 641                 kfree(buf);
 642                 return value;
 643         }
 644         iocb->private = priv;
 645         priv->iv = iv;
 646         priv->nr_segs = nr_segs;
 647
 648         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 649         if (unlikely(value < 0)) {
 650                 kfree(priv);
 651                 goto fail;
 652         }
 653
 654         iocb->ki_cancel = ep_aio_cancel;
 655         get_ep(epdata);
 656         priv->epdata = epdata;
 657         priv->actual = 0;
 658
 659         /* each kiocb is coupled to one usb_request, but we can't
 660          * allocate or submit those if the host disconnected.
 661          */
 662         spin_lock_irq(&epdata->dev->lock);
 663         if (likely(epdata->ep)) {
 664                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 665                 if (likely(req)) {
 666                         priv->req = req;
 667                         req->buf = buf;
 668                         req->length = len;
 669                         req->complete = ep_aio_complete;
 670                         req->context = iocb;
 671                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 672                         if (unlikely(0 != value))
 673                                 usb_ep_free_request(epdata->ep, req);
 674                 } else
 675                         value = -EAGAIN;
 676         } else
 677                 value = -ENODEV;
 678         spin_unlock_irq(&epdata->dev->lock);
 679
 680         up(&epdata->lock);
 681
 682         if (unlikely(value)) {
 683                 kfree(priv);
 684                 put_ep(epdata);
 685         } else
 686                 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
 687         return value;
 688 }
 689
 690 static ssize_t
 691 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
 692                 unsigned long nr_segs, loff_t o)
 693 {
 694         struct ep_data          *epdata = iocb->ki_filp->private_data;
 695         char                    *buf;
 696
 697         if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN))
 698                 return -EINVAL;
 699
 700         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 701         if (unlikely(!buf))
 702                 return -ENOMEM;
 703
 704         iocb->ki_retry = ep_aio_read_retry;
 705         return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
 706 }
 707
 708 static ssize_t
 709 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
 710                 unsigned long nr_segs, loff_t o)
 711 {
 712         struct ep_data          *epdata = iocb->ki_filp->private_data;
 713         char                    *buf;
 714         size_t                  len = 0;
 715         int                     i = 0;
 716
 717         if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN)))
 718                 return -EINVAL;
 719
 720         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 721         if (unlikely(!buf))
 722                 return -ENOMEM;
 723
 724         for (i=0; i < nr_segs; i++) {
 725                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
 726                                 iov[i].iov_len) != 0)) {
 727                         kfree(buf);
 728                         return -EFAULT;
 729                 }
 730                 len += iov[i].iov_len;
 731         }
 732         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
 733 }
 734
 735 /*----------------------------------------------------------------------*/
 736
 737 /* used after endpoint configuration */
 738 static const struct file_operations ep_io_operations = {
 739         .owner =        THIS_MODULE,
 740         .llseek =       no_llseek,
 741
 742         .read =         ep_read,
 743         .write =        ep_write,
 744         .ioctl =        ep_ioctl,
 745         .release =      ep_release,
 746
 747         .aio_read =     ep_aio_read,
 748         .aio_write =    ep_aio_write,
 749 };
 750
 751 /* ENDPOINT INITIALIZATION
 752  *
 753  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 754  *     status = write (fd, descriptors, sizeof descriptors)
 755  *
 756  * That write establishes the endpoint configuration, configuring
 757  * the controller to process bulk, interrupt, or isochronous transfers
 758  * at the right maxpacket size, and so on.
 759  *
 760  * The descriptors are message type 1, identified by a host order u32
 761  * at the beginning of what's written.  Descriptor order is: full/low
 762  * speed descriptor, then optional high speed descriptor.
 763  */
 764 static ssize_t
 765 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 766 {
 767         struct ep_data          *data = fd->private_data;
 768         struct usb_ep           *ep;
 769         u32                     tag;
 770         int                     value, length = len;
 771
 772         if ((value = down_interruptible (&data->lock)) < 0)
 773                 return value;
 774
 775         if (data->state != STATE_EP_READY) {
 776                 value = -EL2HLT;
 777                 goto fail;
 778         }
 779
 780         value = len;
 781         if (len < USB_DT_ENDPOINT_SIZE + 4)
 782                 goto fail0;
 783
 784         /* we might need to change message format someday */
 785         if (copy_from_user (&tag, buf, 4)) {
 786                 goto fail1;
 787         }
 788         if (tag != 1) {
 789                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 790                 goto fail0;
 791         }
 792         buf += 4;
 793         len -= 4;
 794
 795         /* NOTE:  audio endpoint extensions not accepted here;
 796          * just don't include the extra bytes.
 797          */
 798
 799         /* full/low speed descriptor, then high speed */
 800         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 801                 goto fail1;
 802         }
 803         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 804                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 805                 goto fail0;
 806         if (len != USB_DT_ENDPOINT_SIZE) {
 807                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 808                         goto fail0;
 809                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 810                                         USB_DT_ENDPOINT_SIZE)) {
 811                         goto fail1;
 812                 }
 813                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 814                                 || data->hs_desc.bDescriptorType
 815                                         != USB_DT_ENDPOINT) {
 816                         DBG(data->dev, "config %s, bad hs length or type\n",
 817                                         data->name);
 818                         goto fail0;
 819                 }
 820         }
 821
 822         spin_lock_irq (&data->dev->lock);
 823         if (data->dev->state == STATE_DEV_UNBOUND) {
 824                 value = -ENOENT;
 825                 goto gone;
 826         } else if ((ep = data->ep) == NULL) {
 827                 value = -ENODEV;
 828                 goto gone;
 829         }
 830         switch (data->dev->gadget->speed) {
 831         case USB_SPEED_LOW:
 832         case USB_SPEED_FULL:
 833                 value = usb_ep_enable (ep, &data->desc);
 834                 if (value == 0)
 835                         data->state = STATE_EP_ENABLED;
 836                 break;
 837 #ifdef  CONFIG_USB_GADGET_DUALSPEED
 838         case USB_SPEED_HIGH:
 839                 /* fails if caller didn't provide that descriptor... */
 840                 value = usb_ep_enable (ep, &data->hs_desc);
 841                 if (value == 0)
 842                         data->state = STATE_EP_ENABLED;
 843                 break;
 844 #endif
 845         default:
 846                 DBG(data->dev, "unconnected, %s init abandoned\n",
 847                                 data->name);
 848                 value = -EINVAL;
 849         }
 850         if (value == 0) {
 851                 fd->f_op = &ep_io_operations;
 852                 value = length;
 853         }
 854 gone:
 855         spin_unlock_irq (&data->dev->lock);
 856         if (value < 0) {
 857 fail:
 858                 data->desc.bDescriptorType = 0;
 859                 data->hs_desc.bDescriptorType = 0;
 860         }
 861         up (&data->lock);
 862         return value;
 863 fail0:
 864         value = -EINVAL;
 865         goto fail;
 866 fail1:
 867         value = -EFAULT;
 868         goto fail;
 869 }
 870
 871 static int
 872 ep_open (struct inode *inode, struct file *fd)
 873 {
 874         struct ep_data          *data = inode->i_private;
 875         int                     value = -EBUSY;
 876
 877         if (down_interruptible (&data->lock) != 0)
 878                 return -EINTR;
 879         spin_lock_irq (&data->dev->lock);
 880         if (data->dev->state == STATE_DEV_UNBOUND)
 881                 value = -ENOENT;
 882         else if (data->state == STATE_EP_DISABLED) {
 883                 value = 0;
 884                 data->state = STATE_EP_READY;
 885                 get_ep (data);
 886                 fd->private_data = data;
 887                 VDEBUG (data->dev, "%s ready\n", data->name);
 888         } else
 889                 DBG (data->dev, "%s state %d\n",
 890                         data->name, data->state);
 891         spin_unlock_irq (&data->dev->lock);
 892         up (&data->lock);
 893         return value;
 894 }
 895
 896 /* used before endpoint configuration */
 897 static const struct file_operations ep_config_operations = {
 898         .owner =        THIS_MODULE,
 899         .llseek =       no_llseek,
 900
 901         .open =         ep_open,
 902         .write =        ep_config,
 903         .release =      ep_release,
 904 };
 905
 906 /*----------------------------------------------------------------------*/
 907
 908 /* EP0 IMPLEMENTATION can be partly in userspace.
 909  *
 910  * Drivers that use this facility receive various events, including
 911  * control requests the kernel doesn't handle.  Drivers that don't
 912  * use this facility may be too simple-minded for real applications.
 913  */
 914
 915 static inline void ep0_readable (struct dev_data *dev)
 916 {
 917         wake_up (&dev->wait);
 918         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 919 }
 920
 921 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 922 {
 923         struct dev_data         *dev = ep->driver_data;
 924
 925         if (req->buf != dev->rbuf) {
 926                 kfree(req->buf);
 927                 req->buf = dev->rbuf;
 928                 req->dma = DMA_ADDR_INVALID;
 929         }
 930         req->complete = epio_complete;
 931         dev->setup_out_ready = 0;
 932 }
 933
 934 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 935 {
 936         struct dev_data         *dev = ep->driver_data;
 937         unsigned long           flags;
 938         int                     free = 1;
 939
 940         /* for control OUT, data must still get to userspace */
 941         spin_lock_irqsave(&dev->lock, flags);
 942         if (!dev->setup_in) {
 943                 dev->setup_out_error = (req->status != 0);
 944                 if (!dev->setup_out_error)
 945                         free = 0;
 946                 dev->setup_out_ready = 1;
 947                 ep0_readable (dev);
 948         }
 949
 950         /* clean up as appropriate */
 951         if (free && req->buf != &dev->rbuf)
 952                 clean_req (ep, req);
 953         req->complete = epio_complete;
 954         spin_unlock_irqrestore(&dev->lock, flags);
 955 }
 956
 957 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 958 {
 959         struct dev_data *dev = ep->driver_data;
 960
 961         if (dev->setup_out_ready) {
 962                 DBG (dev, "ep0 request busy!\n");
 963                 return -EBUSY;
 964         }
 965         if (len > sizeof (dev->rbuf))
 966                 req->buf = kmalloc(len, GFP_ATOMIC);
 967         if (req->buf == 0) {
 968                 req->buf = dev->rbuf;
 969                 return -ENOMEM;
 970         }
 971         req->complete = ep0_complete;
 972         req->length = len;
 973         req->zero = 0;
 974         return 0;
 975 }
 976
 977 static ssize_t
 978 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 979 {
 980         struct dev_data                 *dev = fd->private_data;
 981         ssize_t                         retval;
 982         enum ep0_state                  state;
 983
 984         spin_lock_irq (&dev->lock);
 985
 986         /* report fd mode change before acting on it */
 987         if (dev->setup_abort) {
 988                 dev->setup_abort = 0;
 989                 retval = -EIDRM;
 990                 goto done;
 991         }
 992
 993         /* control DATA stage */
 994         if ((state = dev->state) == STATE_DEV_SETUP) {
 995
 996                 if (dev->setup_in) {            /* stall IN */
 997                         VDEBUG(dev, "ep0in stall\n");
 998                         (void) usb_ep_set_halt (dev->gadget->ep0);
 999                         retval = -EL2HLT;
1000                         dev->state = STATE_DEV_CONNECTED;
1001
1002                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
1003                         struct usb_ep           *ep = dev->gadget->ep0;
1004                         struct usb_request      *req = dev->req;
1005
1006                         if ((retval = setup_req (ep, req, 0)) == 0)
1007                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1008                         dev->state = STATE_DEV_CONNECTED;
1009
1010                         /* assume that was SET_CONFIGURATION */
1011                         if (dev->current_config) {
1012                                 unsigned power;
1013 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1014                                 if (dev->gadget->speed == USB_SPEED_HIGH)
1015                                         power = dev->hs_config->bMaxPower;
1016                                 else
1017 #endif
1018                                         power = dev->config->bMaxPower;
1019                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1020                         }
1021
1022                 } else {                        /* collect OUT data */
1023                         if ((fd->f_flags & O_NONBLOCK) != 0
1024                                         && !dev->setup_out_ready) {
1025                                 retval = -EAGAIN;
1026                                 goto done;
1027                         }
1028                         spin_unlock_irq (&dev->lock);
1029                         retval = wait_event_interruptible (dev->wait,
1030                                         dev->setup_out_ready != 0);
1031
1032                         /* FIXME state could change from under us */
1033                         spin_lock_irq (&dev->lock);
1034                         if (retval)
1035                                 goto done;
1036
1037                         if (dev->state != STATE_DEV_SETUP) {
1038                                 retval = -ECANCELED;
1039                                 goto done;
1040                         }
1041                         dev->state = STATE_DEV_CONNECTED;
1042
1043                         if (dev->setup_out_error)
1044                                 retval = -EIO;
1045                         else {
1046                                 len = min (len, (size_t)dev->req->actual);
1047 // FIXME don't call this with the spinlock held ...
1048                                 if (copy_to_user (buf, dev->req->buf, len))
1049                                         retval = -EFAULT;
1050                                 clean_req (dev->gadget->ep0, dev->req);
1051                                 /* NOTE userspace can't yet choose to stall */
1052                         }
1053                 }
1054                 goto done;
1055         }
1056
1057         /* else normal: return event data */
1058         if (len < sizeof dev->event [0]) {
1059                 retval = -EINVAL;
1060                 goto done;
1061         }
1062         len -= len % sizeof (struct usb_gadgetfs_event);
1063         dev->usermode_setup = 1;
1064
1065 scan:
1066         /* return queued events right away */
1067         if (dev->ev_next != 0) {
1068                 unsigned                i, n;
1069
1070                 n = len / sizeof (struct usb_gadgetfs_event);
1071                 if (dev->ev_next < n)
1072                         n = dev->ev_next;
1073
1074                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1075                 for (i = 0; i < n; i++) {
1076                         if (dev->event [i].type == GADGETFS_SETUP) {
1077                                 dev->state = STATE_DEV_SETUP;
1078                                 n = i + 1;
1079                                 break;
1080                         }
1081                 }
1082                 spin_unlock_irq (&dev->lock);
1083                 len = n * sizeof (struct usb_gadgetfs_event);
1084                 if (copy_to_user (buf, &dev->event, len))
1085                         retval = -EFAULT;
1086                 else
1087                         retval = len;
1088                 if (len > 0) {
1089                         /* NOTE this doesn't guard against broken drivers;
1090                          * concurrent ep0 readers may lose events.
1091                          */
1092                         spin_lock_irq (&dev->lock);
1093                         if (dev->ev_next > n) {
1094                                 memmove(&dev->event[0], &dev->event[n],
1095                                         sizeof (struct usb_gadgetfs_event)
1096                                                 * (dev->ev_next - n));
1097                         }
1098                         dev->ev_next -= n;
1099                         spin_unlock_irq (&dev->lock);
1100                 }
1101                 return retval;
1102         }
1103         if (fd->f_flags & O_NONBLOCK) {
1104                 retval = -EAGAIN;
1105                 goto done;
1106         }
1107
1108         switch (state) {
1109         default:
1110                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, state);
1111                 retval = -ESRCH;
1112                 break;
1113         case STATE_DEV_UNCONNECTED:
1114         case STATE_DEV_CONNECTED:
1115                 spin_unlock_irq (&dev->lock);
1116                 DBG (dev, "%s wait\n", __FUNCTION__);
1117
1118                 /* wait for events */
1119                 retval = wait_event_interruptible (dev->wait,
1120                                 dev->ev_next != 0);
1121                 if (retval < 0)
1122                         return retval;
1123                 spin_lock_irq (&dev->lock);
1124                 goto scan;
1125         }
1126
1127 done:
1128         spin_unlock_irq (&dev->lock);
1129         return retval;
1130 }
1131
1132 static struct usb_gadgetfs_event *
1133 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1134 {
1135         struct usb_gadgetfs_event       *event;
1136         unsigned                        i;
1137
1138         switch (type) {
1139         /* these events purge the queue */
1140         case GADGETFS_DISCONNECT:
1141                 if (dev->state == STATE_DEV_SETUP)
1142                         dev->setup_abort = 1;
1143                 // FALL THROUGH
1144         case GADGETFS_CONNECT:
1145                 dev->ev_next = 0;
1146                 break;
1147         case GADGETFS_SETUP:            /* previous request timed out */
1148         case GADGETFS_SUSPEND:          /* same effect */
1149                 /* these events can't be repeated */
1150                 for (i = 0; i != dev->ev_next; i++) {
1151                         if (dev->event [i].type != type)
1152                                 continue;
1153                         DBG(dev, "discard old event[%d] %d\n", i, type);
1154                         dev->ev_next--;
1155                         if (i == dev->ev_next)
1156                                 break;
1157                         /* indices start at zero, for simplicity */
1158                         memmove (&dev->event [i], &dev->event [i + 1],
1159                                 sizeof (struct usb_gadgetfs_event)
1160                                         * (dev->ev_next - i));
1161                 }
1162                 break;
1163         default:
1164                 BUG ();
1165         }
1166         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1167         event = &dev->event [dev->ev_next++];
1168         BUG_ON (dev->ev_next > N_EVENT);
1169         memset (event, 0, sizeof *event);
1170         event->type = type;
1171         return event;
1172 }
1173
1174 static ssize_t
1175 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1176 {
1177         struct dev_data         *dev = fd->private_data;
1178         ssize_t                 retval = -ESRCH;
1179
1180         spin_lock_irq (&dev->lock);
1181
1182         /* report fd mode change before acting on it */
1183         if (dev->setup_abort) {
1184                 dev->setup_abort = 0;
1185                 retval = -EIDRM;
1186
1187         /* data and/or status stage for control request */
1188         } else if (dev->state == STATE_DEV_SETUP) {
1189
1190                 /* IN DATA+STATUS caller makes len <= wLength */
1191                 if (dev->setup_in) {
1192                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1193                         if (retval == 0) {
1194                                 dev->state = STATE_DEV_CONNECTED;
1195                                 spin_unlock_irq (&dev->lock);
1196                                 if (copy_from_user (dev->req->buf, buf, len))
1197                                         retval = -EFAULT;
1198                                 else {
1199                                         if (len < dev->setup_wLength)
1200                                                 dev->req->zero = 1;
1201                                         retval = usb_ep_queue (
1202                                                 dev->gadget->ep0, dev->req,
1203                                                 GFP_KERNEL);
1204                                 }
1205                                 if (retval < 0) {
1206                                         spin_lock_irq (&dev->lock);
1207                                         clean_req (dev->gadget->ep0, dev->req);
1208                                         spin_unlock_irq (&dev->lock);
1209                                 } else
1210                                         retval = len;
1211
1212                                 return retval;
1213                         }
1214
1215                 /* can stall some OUT transfers */
1216                 } else if (dev->setup_can_stall) {
1217                         VDEBUG(dev, "ep0out stall\n");
1218                         (void) usb_ep_set_halt (dev->gadget->ep0);
1219                         retval = -EL2HLT;
1220                         dev->state = STATE_DEV_CONNECTED;
1221                 } else {
1222                         DBG(dev, "bogus ep0out stall!\n");
1223                 }
1224         } else
1225                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state);
1226
1227         spin_unlock_irq (&dev->lock);
1228         return retval;
1229 }
1230
1231 static int
1232 ep0_fasync (int f, struct file *fd, int on)
1233 {
1234         struct dev_data         *dev = fd->private_data;
1235         // caller must F_SETOWN before signal delivery happens
1236         VDEBUG (dev, "%s %s\n", __FUNCTION__, on ? "on" : "off");
1237         return fasync_helper (f, fd, on, &dev->fasync);
1238 }
1239
1240 static struct usb_gadget_driver gadgetfs_driver;
1241
1242 static int
1243 dev_release (struct inode *inode, struct file *fd)
1244 {
1245         struct dev_data         *dev = fd->private_data;
1246
1247         /* closing ep0 === shutdown all */
1248
1249         usb_gadget_unregister_driver (&gadgetfs_driver);
1250
1251         /* at this point "good" hardware has disconnected the
1252          * device from USB; the host won't see it any more.
1253          * alternatively, all host requests will time out.
1254          */
1255
1256         fasync_helper (-1, fd, 0, &dev->fasync);
1257         kfree (dev->buf);
1258         dev->buf = NULL;
1259         put_dev (dev);
1260
1261         /* other endpoints were all decoupled from this device */
1262         spin_lock_irq(&dev->lock);
1263         dev->state = STATE_DEV_DISABLED;
1264         spin_unlock_irq(&dev->lock);
1265         return 0;
1266 }
1267
1268 static unsigned int
1269 ep0_poll (struct file *fd, poll_table *wait)
1270 {
1271        struct dev_data         *dev = fd->private_data;
1272        int                     mask = 0;
1273
1274        poll_wait(fd, &dev->wait, wait);
1275
1276        spin_lock_irq (&dev->lock);
1277
1278        /* report fd mode change before acting on it */
1279        if (dev->setup_abort) {
1280                dev->setup_abort = 0;
1281                mask = POLLHUP;
1282                goto out;
1283        }
1284
1285        if (dev->state == STATE_DEV_SETUP) {
1286                if (dev->setup_in || dev->setup_can_stall)
1287                        mask = POLLOUT;
1288        } else {
1289                if (dev->ev_next != 0)
1290                        mask = POLLIN;
1291        }
1292 out:
1293        spin_unlock_irq(&dev->lock);
1294        return mask;
1295 }
1296
1297 static int dev_ioctl (struct inode *inode, struct file *fd,
1298                 unsigned code, unsigned long value)
1299 {
1300         struct dev_data         *dev = fd->private_data;
1301         struct usb_gadget       *gadget = dev->gadget;
1302
1303         if (gadget->ops->ioctl)
1304                 return gadget->ops->ioctl (gadget, code, value);
1305         return -ENOTTY;
1306 }
1307
1308 /* used after device configuration */
1309 static const struct file_operations ep0_io_operations = {
1310         .owner =        THIS_MODULE,
1311         .llseek =       no_llseek,
1312
1313         .read =         ep0_read,
1314         .write =        ep0_write,
1315         .fasync =       ep0_fasync,
1316         .poll =         ep0_poll,
1317         .ioctl =        dev_ioctl,
1318         .release =      dev_release,
1319 };
1320
1321 /*----------------------------------------------------------------------*/
1322
1323 /* The in-kernel gadget driver handles most ep0 issues, in particular
1324  * enumerating the single configuration (as provided from user space).
1325  *
1326  * Unrecognized ep0 requests may be handled in user space.
1327  */
1328
1329 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1330 static void make_qualifier (struct dev_data *dev)
1331 {
1332         struct usb_qualifier_descriptor         qual;
1333         struct usb_device_descriptor            *desc;
1334
1335         qual.bLength = sizeof qual;
1336         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1337         qual.bcdUSB = __constant_cpu_to_le16 (0x0200);
1338
1339         desc = dev->dev;
1340         qual.bDeviceClass = desc->bDeviceClass;
1341         qual.bDeviceSubClass = desc->bDeviceSubClass;
1342         qual.bDeviceProtocol = desc->bDeviceProtocol;
1343
1344         /* assumes ep0 uses the same value for both speeds ... */
1345         qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
1346
1347         qual.bNumConfigurations = 1;
1348         qual.bRESERVED = 0;
1349
1350         memcpy (dev->rbuf, &qual, sizeof qual);
1351 }
1352 #endif
1353
1354 static int
1355 config_buf (struct dev_data *dev, u8 type, unsigned index)
1356 {
1357         int             len;
1358 #ifdef CONFIG_USB_GADGET_DUALSPEED
1359         int             hs;
1360 #endif
1361
1362         /* only one configuration */
1363         if (index > 0)
1364                 return -EINVAL;
1365
1366 #ifdef CONFIG_USB_GADGET_DUALSPEED
1367         hs = (dev->gadget->speed == USB_SPEED_HIGH);
1368         if (type == USB_DT_OTHER_SPEED_CONFIG)
1369                 hs = !hs;
1370         if (hs) {
1371                 dev->req->buf = dev->hs_config;
1372                 len = le16_to_cpu(dev->hs_config->wTotalLength);
1373         } else
1374 #endif
1375         {
1376                 dev->req->buf = dev->config;
1377                 len = le16_to_cpu(dev->config->wTotalLength);
1378         }
1379         ((u8 *)dev->req->buf) [1] = type;
1380         return len;
1381 }
1382
1383 static int
1384 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1385 {
1386         struct dev_data                 *dev = get_gadget_data (gadget);
1387         struct usb_request              *req = dev->req;
1388         int                             value = -EOPNOTSUPP;
1389         struct usb_gadgetfs_event       *event;
1390         u16                             w_value = le16_to_cpu(ctrl->wValue);
1391         u16                             w_length = le16_to_cpu(ctrl->wLength);
1392
1393         spin_lock (&dev->lock);
1394         dev->setup_abort = 0;
1395         if (dev->state == STATE_DEV_UNCONNECTED) {
1396 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1397                 if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) {
1398                         spin_unlock(&dev->lock);
1399                         ERROR (dev, "no high speed config??\n");
1400                         return -EINVAL;
1401                 }
1402 #endif  /* CONFIG_USB_GADGET_DUALSPEED */
1403
1404                 dev->state = STATE_DEV_CONNECTED;
1405                 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1406
1407                 INFO (dev, "connected\n");
1408                 event = next_event (dev, GADGETFS_CONNECT);
1409                 event->u.speed = gadget->speed;
1410                 ep0_readable (dev);
1411
1412         /* host may have given up waiting for response.  we can miss control
1413          * requests handled lower down (device/endpoint status and features);
1414          * then ep0_{read,write} will report the wrong status. controller
1415          * driver will have aborted pending i/o.
1416          */
1417         } else if (dev->state == STATE_DEV_SETUP)
1418                 dev->setup_abort = 1;
1419
1420         req->buf = dev->rbuf;
1421         req->dma = DMA_ADDR_INVALID;
1422         req->context = NULL;
1423         value = -EOPNOTSUPP;
1424         switch (ctrl->bRequest) {
1425
1426         case USB_REQ_GET_DESCRIPTOR:
1427                 if (ctrl->bRequestType != USB_DIR_IN)
1428                         goto unrecognized;
1429                 switch (w_value >> 8) {
1430
1431                 case USB_DT_DEVICE:
1432                         value = min (w_length, (u16) sizeof *dev->dev);
1433                         req->buf = dev->dev;
1434                         break;
1435 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1436                 case USB_DT_DEVICE_QUALIFIER:
1437                         if (!dev->hs_config)
1438                                 break;
1439                         value = min (w_length, (u16)
1440                                 sizeof (struct usb_qualifier_descriptor));
1441                         make_qualifier (dev);
1442                         break;
1443                 case USB_DT_OTHER_SPEED_CONFIG:
1444                         // FALLTHROUGH
1445 #endif
1446                 case USB_DT_CONFIG:
1447                         value = config_buf (dev,
1448                                         w_value >> 8,
1449                                         w_value & 0xff);
1450                         if (value >= 0)
1451                                 value = min (w_length, (u16) value);
1452                         break;
1453                 case USB_DT_STRING:
1454                         goto unrecognized;
1455
1456                 default:                // all others are errors
1457                         break;
1458                 }
1459                 break;
1460
1461         /* currently one config, two speeds */
1462         case USB_REQ_SET_CONFIGURATION:
1463                 if (ctrl->bRequestType != 0)
1464                         break;
1465                 if (0 == (u8) w_value) {
1466                         value = 0;
1467                         dev->current_config = 0;
1468                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1469                         // user mode expected to disable endpoints
1470                 } else {
1471                         u8      config, power;
1472 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1473                         if (gadget->speed == USB_SPEED_HIGH) {
1474                                 config = dev->hs_config->bConfigurationValue;
1475                                 power = dev->hs_config->bMaxPower;
1476                         } else
1477 #endif
1478                         {
1479                                 config = dev->config->bConfigurationValue;
1480                                 power = dev->config->bMaxPower;
1481                         }
1482
1483                         if (config == (u8) w_value) {
1484                                 value = 0;
1485                                 dev->current_config = config;
1486                                 usb_gadget_vbus_draw(gadget, 2 * power);
1487                         }
1488                 }
1489
1490                 /* report SET_CONFIGURATION like any other control request,
1491                  * except that usermode may not stall this.  the next
1492                  * request mustn't be allowed start until this finishes:
1493                  * endpoints and threads set up, etc.
1494                  *
1495                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1496                  * has bad/racey automagic that prevents synchronizing here.
1497                  * even kernel mode drivers often miss them.
1498                  */
1499                 if (value == 0) {
1500                         INFO (dev, "configuration #%d\n", dev->current_config);
1501                         if (dev->usermode_setup) {
1502                                 dev->setup_can_stall = 0;
1503                                 goto delegate;
1504                         }
1505                 }
1506                 break;
1507
1508 #ifndef CONFIG_USB_GADGET_PXA2XX
1509         /* PXA automagically handles this request too */
1510         case USB_REQ_GET_CONFIGURATION:
1511                 if (ctrl->bRequestType != 0x80)
1512                         break;
1513                 *(u8 *)req->buf = dev->current_config;
1514                 value = min (w_length, (u16) 1);
1515                 break;
1516 #endif
1517
1518         default:
1519 unrecognized:
1520                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1521                         dev->usermode_setup ? "delegate" : "fail",
1522                         ctrl->bRequestType, ctrl->bRequest,
1523                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1524
1525                 /* if there's an ep0 reader, don't stall */
1526                 if (dev->usermode_setup) {
1527                         dev->setup_can_stall = 1;
1528 delegate:
1529                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1530                                                 ? 1 : 0;
1531                         dev->setup_wLength = w_length;
1532                         dev->setup_out_ready = 0;
1533                         dev->setup_out_error = 0;
1534                         value = 0;
1535
1536                         /* read DATA stage for OUT right away */
1537                         if (unlikely (!dev->setup_in && w_length)) {
1538                                 value = setup_req (gadget->ep0, dev->req,
1539                                                         w_length);
1540                                 if (value < 0)
1541                                         break;
1542                                 value = usb_ep_queue (gadget->ep0, dev->req,
1543                                                         GFP_ATOMIC);
1544                                 if (value < 0) {
1545                                         clean_req (gadget->ep0, dev->req);
1546                                         break;
1547                                 }
1548
1549                                 /* we can't currently stall these */
1550                                 dev->setup_can_stall = 0;
1551                         }
1552
1553                         /* state changes when reader collects event */
1554                         event = next_event (dev, GADGETFS_SETUP);
1555                         event->u.setup = *ctrl;
1556                         ep0_readable (dev);
1557                         spin_unlock (&dev->lock);
1558                         return 0;
1559                 }
1560         }
1561
1562         /* proceed with data transfer and status phases? */
1563         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1564                 req->length = value;
1565                 req->zero = value < w_length;
1566                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1567                 if (value < 0) {
1568                         DBG (dev, "ep_queue --> %d\n", value);
1569                         req->status = 0;
1570                 }
1571         }
1572
1573         /* device stalls when value < 0 */
1574         spin_unlock (&dev->lock);
1575         return value;
1576 }
1577
1578 static void destroy_ep_files (struct dev_data *dev)
1579 {
1580         struct list_head        *entry, *tmp;
1581
1582         DBG (dev, "%s %d\n", __FUNCTION__, dev->state);
1583
1584         /* dev->state must prevent interference */
1585 restart:
1586         spin_lock_irq (&dev->lock);
1587         list_for_each_safe (entry, tmp, &dev->epfiles) {
1588                 struct ep_data  *ep;
1589                 struct inode    *parent;
1590                 struct dentry   *dentry;
1591
1592                 /* break link to FS */
1593                 ep = list_entry (entry, struct ep_data, epfiles);
1594                 list_del_init (&ep->epfiles);
1595                 dentry = ep->dentry;
1596                 ep->dentry = NULL;
1597                 parent = dentry->d_parent->d_inode;
1598
1599                 /* break link to controller */
1600                 if (ep->state == STATE_EP_ENABLED)
1601                         (void) usb_ep_disable (ep->ep);
1602                 ep->state = STATE_EP_UNBOUND;
1603                 usb_ep_free_request (ep->ep, ep->req);
1604                 ep->ep = NULL;
1605                 wake_up (&ep->wait);
1606                 put_ep (ep);
1607
1608                 spin_unlock_irq (&dev->lock);
1609
1610                 /* break link to dcache */
1611                 mutex_lock (&parent->i_mutex);
1612                 d_delete (dentry);
1613                 dput (dentry);
1614                 mutex_unlock (&parent->i_mutex);
1615
1616                 /* fds may still be open */
1617                 goto restart;
1618         }
1619         spin_unlock_irq (&dev->lock);
1620 }
1621
1622
1623 static struct inode *
1624 gadgetfs_create_file (struct super_block *sb, char const *name,
1625                 void *data, const struct file_operations *fops,
1626                 struct dentry **dentry_p);
1627
1628 static int activate_ep_files (struct dev_data *dev)
1629 {
1630         struct usb_ep   *ep;
1631         struct ep_data  *data;
1632
1633         gadget_for_each_ep (ep, dev->gadget) {
1634
1635                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1636                 if (!data)
1637                         goto enomem0;
1638                 data->state = STATE_EP_DISABLED;
1639                 init_MUTEX (&data->lock);
1640                 init_waitqueue_head (&data->wait);
1641
1642                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1643                 atomic_set (&data->count, 1);
1644                 data->dev = dev;
1645                 get_dev (dev);
1646
1647                 data->ep = ep;
1648                 ep->driver_data = data;
1649
1650                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1651                 if (!data->req)
1652                         goto enomem1;
1653
1654                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1655                                 data, &ep_config_operations,
1656                                 &data->dentry);
1657                 if (!data->inode)
1658                         goto enomem2;
1659                 list_add_tail (&data->epfiles, &dev->epfiles);
1660         }
1661         return 0;
1662
1663 enomem2:
1664         usb_ep_free_request (ep, data->req);
1665 enomem1:
1666         put_dev (dev);
1667         kfree (data);
1668 enomem0:
1669         DBG (dev, "%s enomem\n", __FUNCTION__);
1670         destroy_ep_files (dev);
1671         return -ENOMEM;
1672 }
1673
1674 static void
1675 gadgetfs_unbind (struct usb_gadget *gadget)
1676 {
1677         struct dev_data         *dev = get_gadget_data (gadget);
1678
1679         DBG (dev, "%s\n", __FUNCTION__);
1680
1681         spin_lock_irq (&dev->lock);
1682         dev->state = STATE_DEV_UNBOUND;
1683         spin_unlock_irq (&dev->lock);
1684
1685         destroy_ep_files (dev);
1686         gadget->ep0->driver_data = NULL;
1687         set_gadget_data (gadget, NULL);
1688
1689         /* we've already been disconnected ... no i/o is active */
1690         if (dev->req)
1691                 usb_ep_free_request (gadget->ep0, dev->req);
1692         DBG (dev, "%s done\n", __FUNCTION__);
1693         put_dev (dev);
1694 }
1695
1696 static struct dev_data          *the_device;
1697
1698 static int
1699 gadgetfs_bind (struct usb_gadget *gadget)
1700 {
1701         struct dev_data         *dev = the_device;
1702
1703         if (!dev)
1704                 return -ESRCH;
1705         if (0 != strcmp (CHIP, gadget->name)) {
1706                 printk (KERN_ERR "%s expected %s controller not %s\n",
1707                         shortname, CHIP, gadget->name);
1708                 return -ENODEV;
1709         }
1710
1711         set_gadget_data (gadget, dev);
1712         dev->gadget = gadget;
1713         gadget->ep0->driver_data = dev;
1714         dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1715
1716         /* preallocate control response and buffer */
1717         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1718         if (!dev->req)
1719                 goto enomem;
1720         dev->req->context = NULL;
1721         dev->req->complete = epio_complete;
1722
1723         if (activate_ep_files (dev) < 0)
1724                 goto enomem;
1725
1726         INFO (dev, "bound to %s driver\n", gadget->name);
1727         spin_lock_irq(&dev->lock);
1728         dev->state = STATE_DEV_UNCONNECTED;
1729         spin_unlock_irq(&dev->lock);
1730         get_dev (dev);
1731         return 0;
1732
1733 enomem:
1734         gadgetfs_unbind (gadget);
1735         return -ENOMEM;
1736 }
1737
1738 static void
1739 gadgetfs_disconnect (struct usb_gadget *gadget)
1740 {
1741         struct dev_data         *dev = get_gadget_data (gadget);
1742
1743         spin_lock (&dev->lock);
1744         if (dev->state == STATE_DEV_UNCONNECTED)
1745                 goto exit;
1746         dev->state = STATE_DEV_UNCONNECTED;
1747
1748         INFO (dev, "disconnected\n");
1749         next_event (dev, GADGETFS_DISCONNECT);
1750         ep0_readable (dev);
1751 exit:
1752         spin_unlock (&dev->lock);
1753 }
1754
1755 static void
1756 gadgetfs_suspend (struct usb_gadget *gadget)
1757 {
1758         struct dev_data         *dev = get_gadget_data (gadget);
1759
1760         INFO (dev, "suspended from state %d\n", dev->state);
1761         spin_lock (&dev->lock);
1762         switch (dev->state) {
1763         case STATE_DEV_SETUP:           // VERY odd... host died??
1764         case STATE_DEV_CONNECTED:
1765         case STATE_DEV_UNCONNECTED:
1766                 next_event (dev, GADGETFS_SUSPEND);
1767                 ep0_readable (dev);
1768                 /* FALLTHROUGH */
1769         default:
1770                 break;
1771         }
1772         spin_unlock (&dev->lock);
1773 }
1774
1775 static struct usb_gadget_driver gadgetfs_driver = {
1776 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1777         .speed          = USB_SPEED_HIGH,
1778 #else
1779         .speed          = USB_SPEED_FULL,
1780 #endif
1781         .function       = (char *) driver_desc,
1782         .bind           = gadgetfs_bind,
1783         .unbind         = gadgetfs_unbind,
1784         .setup          = gadgetfs_setup,
1785         .disconnect     = gadgetfs_disconnect,
1786         .suspend        = gadgetfs_suspend,
1787
1788         .driver = {
1789                 .name           = (char *) shortname,
1790         },
1791 };
1792
1793 /*----------------------------------------------------------------------*/
1794
1795 static void gadgetfs_nop(struct usb_gadget *arg) { }
1796
1797 static int gadgetfs_probe (struct usb_gadget *gadget)
1798 {
1799         CHIP = gadget->name;
1800         return -EISNAM;
1801 }
1802
1803 static struct usb_gadget_driver probe_driver = {
1804         .speed          = USB_SPEED_HIGH,
1805         .bind           = gadgetfs_probe,
1806         .unbind         = gadgetfs_nop,
1807         .setup          = (void *)gadgetfs_nop,
1808         .disconnect     = gadgetfs_nop,
1809         .driver = {
1810                 .name           = "nop",
1811         },
1812 };
1813
1814
1815 /* DEVICE INITIALIZATION
1816  *
1817  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1818  *     status = write (fd, descriptors, sizeof descriptors)
1819  *
1820  * That write establishes the device configuration, so the kernel can
1821  * bind to the controller ... guaranteeing it can handle enumeration
1822  * at all necessary speeds.  Descriptor order is:
1823  *
1824  * . message tag (u32, host order) ... for now, must be zero; it
1825  *      would change to support features like multi-config devices
1826  * . full/low speed config ... all wTotalLength bytes (with interface,
1827  *      class, altsetting, endpoint, and other descriptors)
1828  * . high speed config ... all descriptors, for high speed operation;
1829  *      this one's optional except for high-speed hardware
1830  * . device descriptor
1831  *
1832  * Endpoints are not yet enabled. Drivers must wait until device
1833  * configuration and interface altsetting changes create
1834  * the need to configure (or unconfigure) them.
1835  *
1836  * After initialization, the device stays active for as long as that
1837  * $CHIP file is open.  Events must then be read from that descriptor,
1838  * such as configuration notifications.
1839  */
1840
1841 static int is_valid_config (struct usb_config_descriptor *config)
1842 {
1843         return config->bDescriptorType == USB_DT_CONFIG
1844                 && config->bLength == USB_DT_CONFIG_SIZE
1845                 && config->bConfigurationValue != 0
1846                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1847                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1848         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1849         /* FIXME check lengths: walk to end */
1850 }
1851
1852 static ssize_t
1853 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1854 {
1855         struct dev_data         *dev = fd->private_data;
1856         ssize_t                 value = len, length = len;
1857         unsigned                total;
1858         u32                     tag;
1859         char                    *kbuf;
1860
1861         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1862                 return -EINVAL;
1863
1864         /* we might need to change message format someday */
1865         if (copy_from_user (&tag, buf, 4))
1866                 return -EFAULT;
1867         if (tag != 0)
1868                 return -EINVAL;
1869         buf += 4;
1870         length -= 4;
1871
1872         kbuf = kmalloc (length, GFP_KERNEL);
1873         if (!kbuf)
1874                 return -ENOMEM;
1875         if (copy_from_user (kbuf, buf, length)) {
1876                 kfree (kbuf);
1877                 return -EFAULT;
1878         }
1879
1880         spin_lock_irq (&dev->lock);
1881         value = -EINVAL;
1882         if (dev->buf)
1883                 goto fail;
1884         dev->buf = kbuf;
1885
1886         /* full or low speed config */
1887         dev->config = (void *) kbuf;
1888         total = le16_to_cpu(dev->config->wTotalLength);
1889         if (!is_valid_config (dev->config) || total >= length)
1890                 goto fail;
1891         kbuf += total;
1892         length -= total;
1893
1894         /* optional high speed config */
1895         if (kbuf [1] == USB_DT_CONFIG) {
1896                 dev->hs_config = (void *) kbuf;
1897                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1898                 if (!is_valid_config (dev->hs_config) || total >= length)
1899                         goto fail;
1900                 kbuf += total;
1901                 length -= total;
1902         }
1903
1904         /* could support multiple configs, using another encoding! */
1905
1906         /* device descriptor (tweaked for paranoia) */
1907         if (length != USB_DT_DEVICE_SIZE)
1908                 goto fail;
1909         dev->dev = (void *)kbuf;
1910         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1911                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1912                         || dev->dev->bNumConfigurations != 1)
1913                 goto fail;
1914         dev->dev->bNumConfigurations = 1;
1915         dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200);
1916
1917         /* triggers gadgetfs_bind(); then we can enumerate. */
1918         spin_unlock_irq (&dev->lock);
1919         value = usb_gadget_register_driver (&gadgetfs_driver);
1920         if (value != 0) {
1921                 kfree (dev->buf);
1922                 dev->buf = NULL;
1923         } else {
1924                 /* at this point "good" hardware has for the first time
1925                  * let the USB the host see us.  alternatively, if users
1926                  * unplug/replug that will clear all the error state.
1927                  *
1928                  * note:  everything running before here was guaranteed
1929                  * to choke driver model style diagnostics.  from here
1930                  * on, they can work ... except in cleanup paths that
1931                  * kick in after the ep0 descriptor is closed.
1932                  */
1933                 fd->f_op = &ep0_io_operations;
1934                 value = len;
1935         }
1936         return value;
1937
1938 fail:
1939         spin_unlock_irq (&dev->lock);
1940         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __FUNCTION__, value, dev);
1941         kfree (dev->buf);
1942         dev->buf = NULL;
1943         return value;
1944 }
1945
1946 static int
1947 dev_open (struct inode *inode, struct file *fd)
1948 {
1949         struct dev_data         *dev = inode->i_private;
1950         int                     value = -EBUSY;
1951
1952         spin_lock_irq(&dev->lock);
1953         if (dev->state == STATE_DEV_DISABLED) {
1954                 dev->ev_next = 0;
1955                 dev->state = STATE_DEV_OPENED;
1956                 fd->private_data = dev;
1957                 get_dev (dev);
1958                 value = 0;
1959         }
1960         spin_unlock_irq(&dev->lock);
1961         return value;
1962 }
1963
1964 static const struct file_operations dev_init_operations = {
1965         .owner =        THIS_MODULE,
1966         .llseek =       no_llseek,
1967
1968         .open =         dev_open,
1969         .write =        dev_config,
1970         .fasync =       ep0_fasync,
1971         .ioctl =        dev_ioctl,
1972         .release =      dev_release,
1973 };
1974
1975 /*----------------------------------------------------------------------*/
1976
1977 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1978  *
1979  * Mounting the filesystem creates a controller file, used first for
1980  * device configuration then later for event monitoring.
1981  */
1982
1983
1984 /* FIXME PAM etc could set this security policy without mount options
1985  * if epfiles inherited ownership and permissons from ep0 ...
1986  */
1987
1988 static unsigned default_uid;
1989 static unsigned default_gid;
1990 static unsigned default_perm = S_IRUSR | S_IWUSR;
1991
1992 module_param (default_uid, uint, 0644);
1993 module_param (default_gid, uint, 0644);
1994 module_param (default_perm, uint, 0644);
1995
1996
1997 static struct inode *
1998 gadgetfs_make_inode (struct super_block *sb,
1999                 void *data, const struct file_operations *fops,
2000                 int mode)
2001 {
2002         struct inode *inode = new_inode (sb);
2003
2004         if (inode) {
2005                 inode->i_mode = mode;
2006                 inode->i_uid = default_uid;
2007                 inode->i_gid = default_gid;
2008                 inode->i_blocks = 0;
2009                 inode->i_atime = inode->i_mtime = inode->i_ctime
2010                                 = CURRENT_TIME;
2011                 inode->i_private = data;
2012                 inode->i_fop = fops;
2013         }
2014         return inode;
2015 }
2016
2017 /* creates in fs root directory, so non-renamable and non-linkable.
2018  * so inode and dentry are paired, until device reconfig.
2019  */
2020 static struct inode *
2021 gadgetfs_create_file (struct super_block *sb, char const *name,
2022                 void *data, const struct file_operations *fops,
2023                 struct dentry **dentry_p)
2024 {
2025         struct dentry   *dentry;
2026         struct inode    *inode;
2027
2028         dentry = d_alloc_name(sb->s_root, name);
2029         if (!dentry)
2030                 return NULL;
2031
2032         inode = gadgetfs_make_inode (sb, data, fops,
2033                         S_IFREG | (default_perm & S_IRWXUGO));
2034         if (!inode) {
2035                 dput(dentry);
2036                 return NULL;
2037         }
2038         d_add (dentry, inode);
2039         *dentry_p = dentry;
2040         return inode;
2041 }
2042
2043 static struct super_operations gadget_fs_operations = {
2044         .statfs =       simple_statfs,
2045         .drop_inode =   generic_delete_inode,
2046 };
2047
2048 static int
2049 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2050 {
2051         struct inode    *inode;
2052         struct dentry   *d;
2053         struct dev_data *dev;
2054
2055         if (the_device)
2056                 return -ESRCH;
2057
2058         /* fake probe to determine $CHIP */
2059         (void) usb_gadget_register_driver (&probe_driver);
2060         if (!CHIP)
2061                 return -ENODEV;
2062
2063         /* superblock */
2064         sb->s_blocksize = PAGE_CACHE_SIZE;
2065         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2066         sb->s_magic = GADGETFS_MAGIC;
2067         sb->s_op = &gadget_fs_operations;
2068         sb->s_time_gran = 1;
2069
2070         /* root inode */
2071         inode = gadgetfs_make_inode (sb,
2072                         NULL, &simple_dir_operations,
2073                         S_IFDIR | S_IRUGO | S_IXUGO);
2074         if (!inode)
2075                 goto enomem0;
2076         inode->i_op = &simple_dir_inode_operations;
2077         if (!(d = d_alloc_root (inode)))
2078                 goto enomem1;
2079         sb->s_root = d;
2080
2081         /* the ep0 file is named after the controller we expect;
2082          * user mode code can use it for sanity checks, like we do.
2083          */
2084         dev = dev_new ();
2085         if (!dev)
2086                 goto enomem2;
2087
2088         dev->sb = sb;
2089         if (!gadgetfs_create_file (sb, CHIP,
2090                                 dev, &dev_init_operations,
2091                                 &dev->dentry))
2092                 goto enomem3;
2093
2094         /* other endpoint files are available after hardware setup,
2095          * from binding to a controller.
2096          */
2097         the_device = dev;
2098         return 0;
2099
2100 enomem3:
2101         put_dev (dev);
2102 enomem2:
2103         dput (d);
2104 enomem1:
2105         iput (inode);
2106 enomem0:
2107         return -ENOMEM;
2108 }
2109
2110 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2111 static int
2112 gadgetfs_get_sb (struct file_system_type *t, int flags,
2113                 const char *path, void *opts, struct vfsmount *mnt)
2114 {
2115         return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt);
2116 }
2117
2118 static void
2119 gadgetfs_kill_sb (struct super_block *sb)
2120 {
2121         kill_litter_super (sb);
2122         if (the_device) {
2123                 put_dev (the_device);
2124                 the_device = NULL;
2125         }
2126 }
2127
2128 /*----------------------------------------------------------------------*/
2129
2130 static struct file_system_type gadgetfs_type = {
2131         .owner          = THIS_MODULE,
2132         .name           = shortname,
2133         .get_sb         = gadgetfs_get_sb,
2134         .kill_sb        = gadgetfs_kill_sb,
2135 };
2136
2137 /*----------------------------------------------------------------------*/
2138
2139 static int __init init (void)
2140 {
2141         int status;
2142
2143         status = register_filesystem (&gadgetfs_type);
2144         if (status == 0)
2145                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2146                         shortname, driver_desc);
2147         return status;
2148 }
2149 module_init (init);
2150
2151 static void __exit cleanup (void)
2152 {
2153         pr_debug ("unregister %s\n", shortname);
2154         unregister_filesystem (&gadgetfs_type);
2155 }
2156 module_exit (cleanup);
2157