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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/$CHIP is configured
  58  *   (by writing configuration and device descriptors).  Afterwards it
  59  *   may serve as a source of device events, used to handle all control
  60  *   requests other than basic enumeration.
  61  *
  62  * - Then either immediately, or after a SET_CONFIGURATION control request,
  63  *   ep_config() is called when each /dev/gadget/ep* file is configured
  64  *   (by writing endpoint descriptors).  Afterwards these files are used
  65  *   to write() IN data or to read() OUT data.  To halt the endpoint, a
  66  *   "wrong direction" request is issued (like reading an IN endpoint).
  67  *
  68  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
  69  * not possible on all hardware.  For example, precise fault handling with
  70  * respect to data left in endpoint fifos after aborted operations; or
  71  * selective clearing of endpoint halts, to implement SET_INTERFACE.
  72  */
  73
  74 #define DRIVER_DESC     "USB Gadget filesystem"
  75 #define DRIVER_VERSION  "24 Aug 2004"
  76
  77 static const char driver_desc [] = DRIVER_DESC;
  78 static const char shortname [] = "gadgetfs";
  79
  80 MODULE_DESCRIPTION (DRIVER_DESC);
  81 MODULE_AUTHOR ("David Brownell");
  82 MODULE_LICENSE ("GPL");
  83
  84
  85 /*----------------------------------------------------------------------*/
  86
  87 #define GADGETFS_MAGIC          0xaee71ee7
  88 #define DMA_ADDR_INVALID        (~(dma_addr_t)0)
  89
  90 /* /dev/gadget/$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_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_UNCONNECTED,
 109         STATE_CONNECTED,
 110         STATE_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;
 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_DEFER_ENABLE,
 192         STATE_EP_ENABLED,
 193         STATE_EP_UNBOUND,
 194 };
 195
 196 struct ep_data {
 197         struct semaphore                lock;
 198         enum ep_state                   state;
 199         atomic_t                        count;
 200         struct dev_data                 *dev;
 201         /* must hold dev->lock before accessing ep or req */
 202         struct usb_ep                   *ep;
 203         struct usb_request              *req;
 204         ssize_t                         status;
 205         char                            name [16];
 206         struct usb_endpoint_descriptor  desc, hs_desc;
 207         struct list_head                epfiles;
 208         wait_queue_head_t               wait;
 209         struct dentry                   *dentry;
 210         struct inode                    *inode;
 211 };
 212
 213 static inline void get_ep (struct ep_data *data)
 214 {
 215         atomic_inc (&data->count);
 216 }
 217
 218 static void put_ep (struct ep_data *data)
 219 {
 220         if (likely (!atomic_dec_and_test (&data->count)))
 221                 return;
 222         put_dev (data->dev);
 223         /* needs no more cleanup */
 224         BUG_ON (!list_empty (&data->epfiles));
 225         BUG_ON (waitqueue_active (&data->wait));
 226         kfree (data);
 227 }
 228
 229 /*----------------------------------------------------------------------*/
 230
 231 /* most "how to use the hardware" policy choices are in userspace:
 232  * mapping endpoint roles (which the driver needs) to the capabilities
 233  * which the usb controller has.  most of those capabilities are exposed
 234  * implicitly, starting with the driver name and then endpoint names.
 235  */
 236
 237 static const char *CHIP;
 238
 239 /*----------------------------------------------------------------------*/
 240
 241 /* NOTE:  don't use dev_printk calls before binding to the gadget
 242  * at the end of ep0 configuration, or after unbind.
 243  */
 244
 245 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
 246 #define xprintk(d,level,fmt,args...) \
 247         printk(level "%s: " fmt , shortname , ## args)
 248
 249 #ifdef DEBUG
 250 #define DBG(dev,fmt,args...) \
 251         xprintk(dev , KERN_DEBUG , fmt , ## args)
 252 #else
 253 #define DBG(dev,fmt,args...) \
 254         do { } while (0)
 255 #endif /* DEBUG */
 256
 257 #ifdef VERBOSE
 258 #define VDEBUG  DBG
 259 #else
 260 #define VDEBUG(dev,fmt,args...) \
 261         do { } while (0)
 262 #endif /* DEBUG */
 263
 264 #define ERROR(dev,fmt,args...) \
 265         xprintk(dev , KERN_ERR , fmt , ## args)
 266 #define WARN(dev,fmt,args...) \
 267         xprintk(dev , KERN_WARNING , fmt , ## args)
 268 #define INFO(dev,fmt,args...) \
 269         xprintk(dev , KERN_INFO , fmt , ## args)
 270
 271
 272 /*----------------------------------------------------------------------*/
 273
 274 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 275  *
 276  * After opening, configure non-control endpoints.  Then use normal
 277  * stream read() and write() requests; and maybe ioctl() to get more
 278  * precise FIFO status when recovering from cancellation.
 279  */
 280
 281 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 282 {
 283         struct ep_data  *epdata = ep->driver_data;
 284
 285         if (!req->context)
 286                 return;
 287         if (req->status)
 288                 epdata->status = req->status;
 289         else
 290                 epdata->status = req->actual;
 291         complete ((struct completion *)req->context);
 292 }
 293
 294 /* tasklock endpoint, returning when it's connected.
 295  * still need dev->lock to use epdata->ep.
 296  */
 297 static int
 298 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
 299 {
 300         int     val;
 301
 302         if (f_flags & O_NONBLOCK) {
 303                 if (down_trylock (&epdata->lock) != 0)
 304                         goto nonblock;
 305                 if (epdata->state != STATE_EP_ENABLED) {
 306                         up (&epdata->lock);
 307 nonblock:
 308                         val = -EAGAIN;
 309                 } else
 310                         val = 0;
 311                 return val;
 312         }
 313
 314         if ((val = down_interruptible (&epdata->lock)) < 0)
 315                 return val;
 316 newstate:
 317         switch (epdata->state) {
 318         case STATE_EP_ENABLED:
 319                 break;
 320         case STATE_EP_DEFER_ENABLE:
 321                 DBG (epdata->dev, "%s wait for host\n", epdata->name);
 322                 if ((val = wait_event_interruptible (epdata->wait,
 323                                 epdata->state != STATE_EP_DEFER_ENABLE
 324                                 || epdata->dev->state == STATE_DEV_UNBOUND
 325                                 )) < 0)
 326                         goto fail;
 327                 goto newstate;
 328         // case STATE_EP_DISABLED:              /* "can't happen" */
 329         // case STATE_EP_READY:                 /* "can't happen" */
 330         default:                                /* error! */
 331                 pr_debug ("%s: ep %p not available, state %d\n",
 332                                 shortname, epdata, epdata->state);
 333                 // FALLTHROUGH
 334         case STATE_EP_UNBOUND:                  /* clean disconnect */
 335                 val = -ENODEV;
 336 fail:
 337                 up (&epdata->lock);
 338         }
 339         return val;
 340 }
 341
 342 static ssize_t
 343 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 344 {
 345         DECLARE_COMPLETION (done);
 346         int value;
 347
 348         spin_lock_irq (&epdata->dev->lock);
 349         if (likely (epdata->ep != NULL)) {
 350                 struct usb_request      *req = epdata->req;
 351
 352                 req->context = &done;
 353                 req->complete = epio_complete;
 354                 req->buf = buf;
 355                 req->length = len;
 356                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 357         } else
 358                 value = -ENODEV;
 359         spin_unlock_irq (&epdata->dev->lock);
 360
 361         if (likely (value == 0)) {
 362                 value = wait_event_interruptible (done.wait, done.done);
 363                 if (value != 0) {
 364                         spin_lock_irq (&epdata->dev->lock);
 365                         if (likely (epdata->ep != NULL)) {
 366                                 DBG (epdata->dev, "%s i/o interrupted\n",
 367                                                 epdata->name);
 368                                 usb_ep_dequeue (epdata->ep, epdata->req);
 369                                 spin_unlock_irq (&epdata->dev->lock);
 370
 371                                 wait_event (done.wait, done.done);
 372                                 if (epdata->status == -ECONNRESET)
 373                                         epdata->status = -EINTR;
 374                         } else {
 375                                 spin_unlock_irq (&epdata->dev->lock);
 376
 377                                 DBG (epdata->dev, "endpoint gone\n");
 378                                 epdata->status = -ENODEV;
 379                         }
 380                 }
 381                 return epdata->status;
 382         }
 383         return value;
 384 }
 385
 386
 387 /* handle a synchronous OUT bulk/intr/iso transfer */
 388 static ssize_t
 389 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 390 {
 391         struct ep_data          *data = fd->private_data;
 392         void                    *kbuf;
 393         ssize_t                 value;
 394
 395         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 396                 return value;
 397
 398         /* halt any endpoint by doing a "wrong direction" i/o call */
 399         if (data->desc.bEndpointAddress & USB_DIR_IN) {
 400                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 401                                 == USB_ENDPOINT_XFER_ISOC)
 402                         return -EINVAL;
 403                 DBG (data->dev, "%s halt\n", data->name);
 404                 spin_lock_irq (&data->dev->lock);
 405                 if (likely (data->ep != NULL))
 406                         usb_ep_set_halt (data->ep);
 407                 spin_unlock_irq (&data->dev->lock);
 408                 up (&data->lock);
 409                 return -EBADMSG;
 410         }
 411
 412         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
 413
 414         value = -ENOMEM;
 415         kbuf = kmalloc (len, SLAB_KERNEL);
 416         if (unlikely (!kbuf))
 417                 goto free1;
 418
 419         value = ep_io (data, kbuf, len);
 420         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
 421                 data->name, len, (int) value);
 422         if (value >= 0 && copy_to_user (buf, kbuf, value))
 423                 value = -EFAULT;
 424
 425 free1:
 426         up (&data->lock);
 427         kfree (kbuf);
 428         return value;
 429 }
 430
 431 /* handle a synchronous IN bulk/intr/iso transfer */
 432 static ssize_t
 433 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 434 {
 435         struct ep_data          *data = fd->private_data;
 436         void                    *kbuf;
 437         ssize_t                 value;
 438
 439         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 440                 return value;
 441
 442         /* halt any endpoint by doing a "wrong direction" i/o call */
 443         if (!(data->desc.bEndpointAddress & USB_DIR_IN)) {
 444                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 445                                 == USB_ENDPOINT_XFER_ISOC)
 446                         return -EINVAL;
 447                 DBG (data->dev, "%s halt\n", data->name);
 448                 spin_lock_irq (&data->dev->lock);
 449                 if (likely (data->ep != NULL))
 450                         usb_ep_set_halt (data->ep);
 451                 spin_unlock_irq (&data->dev->lock);
 452                 up (&data->lock);
 453                 return -EBADMSG;
 454         }
 455
 456         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
 457
 458         value = -ENOMEM;
 459         kbuf = kmalloc (len, SLAB_KERNEL);
 460         if (!kbuf)
 461                 goto free1;
 462         if (copy_from_user (kbuf, buf, len)) {
 463                 value = -EFAULT;
 464                 goto free1;
 465         }
 466
 467         value = ep_io (data, kbuf, len);
 468         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
 469                 data->name, len, (int) value);
 470 free1:
 471         up (&data->lock);
 472         kfree (kbuf);
 473         return value;
 474 }
 475
 476 static int
 477 ep_release (struct inode *inode, struct file *fd)
 478 {
 479         struct ep_data          *data = fd->private_data;
 480         int value;
 481
 482         if ((value = down_interruptible(&data->lock)) < 0)
 483                 return value;
 484
 485         /* clean up if this can be reopened */
 486         if (data->state != STATE_EP_UNBOUND) {
 487                 data->state = STATE_EP_DISABLED;
 488                 data->desc.bDescriptorType = 0;
 489                 data->hs_desc.bDescriptorType = 0;
 490                 usb_ep_disable(data->ep);
 491         }
 492         up (&data->lock);
 493         put_ep (data);
 494         return 0;
 495 }
 496
 497 static int ep_ioctl (struct inode *inode, struct file *fd,
 498                 unsigned code, unsigned long value)
 499 {
 500         struct ep_data          *data = fd->private_data;
 501         int                     status;
 502
 503         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 504                 return status;
 505
 506         spin_lock_irq (&data->dev->lock);
 507         if (likely (data->ep != NULL)) {
 508                 switch (code) {
 509                 case GADGETFS_FIFO_STATUS:
 510                         status = usb_ep_fifo_status (data->ep);
 511                         break;
 512                 case GADGETFS_FIFO_FLUSH:
 513                         usb_ep_fifo_flush (data->ep);
 514                         break;
 515                 case GADGETFS_CLEAR_HALT:
 516                         status = usb_ep_clear_halt (data->ep);
 517                         break;
 518                 default:
 519                         status = -ENOTTY;
 520                 }
 521         } else
 522                 status = -ENODEV;
 523         spin_unlock_irq (&data->dev->lock);
 524         up (&data->lock);
 525         return status;
 526 }
 527
 528 /*----------------------------------------------------------------------*/
 529
 530 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 531
 532 struct kiocb_priv {
 533         struct usb_request      *req;
 534         struct ep_data          *epdata;
 535         void                    *buf;
 536         char __user             *ubuf;          /* NULL for writes */
 537         unsigned                actual;
 538 };
 539
 540 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
 541 {
 542         struct kiocb_priv       *priv = iocb->private;
 543         struct ep_data          *epdata;
 544         int                     value;
 545
 546         local_irq_disable();
 547         epdata = priv->epdata;
 548         // spin_lock(&epdata->dev->lock);
 549         kiocbSetCancelled(iocb);
 550         if (likely(epdata && epdata->ep && priv->req))
 551                 value = usb_ep_dequeue (epdata->ep, priv->req);
 552         else
 553                 value = -EINVAL;
 554         // spin_unlock(&epdata->dev->lock);
 555         local_irq_enable();
 556
 557         aio_put_req(iocb);
 558         return value;
 559 }
 560
 561 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
 562 {
 563         struct kiocb_priv       *priv = iocb->private;
 564         ssize_t                 status = priv->actual;
 565
 566         /* we "retry" to get the right mm context for this: */
 567         status = copy_to_user(priv->ubuf, priv->buf, priv->actual);
 568         if (unlikely(0 != status))
 569                 status = -EFAULT;
 570         else
 571                 status = priv->actual;
 572         kfree(priv->buf);
 573         kfree(priv);
 574         return status;
 575 }
 576
 577 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 578 {
 579         struct kiocb            *iocb = req->context;
 580         struct kiocb_priv       *priv = iocb->private;
 581         struct ep_data          *epdata = priv->epdata;
 582
 583         /* lock against disconnect (and ideally, cancel) */
 584         spin_lock(&epdata->dev->lock);
 585         priv->req = NULL;
 586         priv->epdata = NULL;
 587         if (priv->ubuf == NULL
 588                         || unlikely(req->actual == 0)
 589                         || unlikely(kiocbIsCancelled(iocb))) {
 590                 kfree(req->buf);
 591                 kfree(priv);
 592                 iocb->private = NULL;
 593                 /* aio_complete() reports bytes-transferred _and_ faults */
 594                 if (unlikely(kiocbIsCancelled(iocb)))
 595                         aio_put_req(iocb);
 596                 else
 597                         aio_complete(iocb,
 598                                 req->actual ? req->actual : req->status,
 599                                 req->status);
 600         } else {
 601                 /* retry() won't report both; so we hide some faults */
 602                 if (unlikely(0 != req->status))
 603                         DBG(epdata->dev, "%s fault %d len %d\n",
 604                                 ep->name, req->status, req->actual);
 605
 606                 priv->buf = req->buf;
 607                 priv->actual = req->actual;
 608                 kick_iocb(iocb);
 609         }
 610         spin_unlock(&epdata->dev->lock);
 611
 612         usb_ep_free_request(ep, req);
 613         put_ep(epdata);
 614 }
 615
 616 static ssize_t
 617 ep_aio_rwtail(
 618         struct kiocb    *iocb,
 619         char            *buf,
 620         size_t          len,
 621         struct ep_data  *epdata,
 622         char __user     *ubuf
 623 )
 624 {
 625         struct kiocb_priv       *priv;
 626         struct usb_request      *req;
 627         ssize_t                 value;
 628
 629         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 630         if (!priv) {
 631                 value = -ENOMEM;
 632 fail:
 633                 kfree(buf);
 634                 return value;
 635         }
 636         iocb->private = priv;
 637         priv->ubuf = ubuf;
 638
 639         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 640         if (unlikely(value < 0)) {
 641                 kfree(priv);
 642                 goto fail;
 643         }
 644
 645         iocb->ki_cancel = ep_aio_cancel;
 646         get_ep(epdata);
 647         priv->epdata = epdata;
 648         priv->actual = 0;
 649
 650         /* each kiocb is coupled to one usb_request, but we can't
 651          * allocate or submit those if the host disconnected.
 652          */
 653         spin_lock_irq(&epdata->dev->lock);
 654         if (likely(epdata->ep)) {
 655                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 656                 if (likely(req)) {
 657                         priv->req = req;
 658                         req->buf = buf;
 659                         req->length = len;
 660                         req->complete = ep_aio_complete;
 661                         req->context = iocb;
 662                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 663                         if (unlikely(0 != value))
 664                                 usb_ep_free_request(epdata->ep, req);
 665                 } else
 666                         value = -EAGAIN;
 667         } else
 668                 value = -ENODEV;
 669         spin_unlock_irq(&epdata->dev->lock);
 670
 671         up(&epdata->lock);
 672
 673         if (unlikely(value)) {
 674                 kfree(priv);
 675                 put_ep(epdata);
 676         } else
 677                 value = (ubuf ? -EIOCBRETRY : -EIOCBQUEUED);
 678         return value;
 679 }
 680
 681 static ssize_t
 682 ep_aio_read(struct kiocb *iocb, char __user *ubuf, size_t len, loff_t o)
 683 {
 684         struct ep_data          *epdata = iocb->ki_filp->private_data;
 685         char                    *buf;
 686
 687         if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN))
 688                 return -EINVAL;
 689         buf = kmalloc(len, GFP_KERNEL);
 690         if (unlikely(!buf))
 691                 return -ENOMEM;
 692         iocb->ki_retry = ep_aio_read_retry;
 693         return ep_aio_rwtail(iocb, buf, len, epdata, ubuf);
 694 }
 695
 696 static ssize_t
 697 ep_aio_write(struct kiocb *iocb, const char __user *ubuf, size_t len, loff_t o)
 698 {
 699         struct ep_data          *epdata = iocb->ki_filp->private_data;
 700         char                    *buf;
 701
 702         if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN)))
 703                 return -EINVAL;
 704         buf = kmalloc(len, GFP_KERNEL);
 705         if (unlikely(!buf))
 706                 return -ENOMEM;
 707         if (unlikely(copy_from_user(buf, ubuf, len) != 0)) {
 708                 kfree(buf);
 709                 return -EFAULT;
 710         }
 711         return ep_aio_rwtail(iocb, buf, len, epdata, NULL);
 712 }
 713
 714 /*----------------------------------------------------------------------*/
 715
 716 /* used after endpoint configuration */
 717 static const struct file_operations ep_io_operations = {
 718         .owner =        THIS_MODULE,
 719         .llseek =       no_llseek,
 720
 721         .read =         ep_read,
 722         .write =        ep_write,
 723         .ioctl =        ep_ioctl,
 724         .release =      ep_release,
 725
 726         .aio_read =     ep_aio_read,
 727         .aio_write =    ep_aio_write,
 728 };
 729
 730 /* ENDPOINT INITIALIZATION
 731  *
 732  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 733  *     status = write (fd, descriptors, sizeof descriptors)
 734  *
 735  * That write establishes the endpoint configuration, configuring
 736  * the controller to process bulk, interrupt, or isochronous transfers
 737  * at the right maxpacket size, and so on.
 738  *
 739  * The descriptors are message type 1, identified by a host order u32
 740  * at the beginning of what's written.  Descriptor order is: full/low
 741  * speed descriptor, then optional high speed descriptor.
 742  */
 743 static ssize_t
 744 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 745 {
 746         struct ep_data          *data = fd->private_data;
 747         struct usb_ep           *ep;
 748         u32                     tag;
 749         int                     value, length = len;
 750
 751         if ((value = down_interruptible (&data->lock)) < 0)
 752                 return value;
 753
 754         if (data->state != STATE_EP_READY) {
 755                 value = -EL2HLT;
 756                 goto fail;
 757         }
 758
 759         value = len;
 760         if (len < USB_DT_ENDPOINT_SIZE + 4)
 761                 goto fail0;
 762
 763         /* we might need to change message format someday */
 764         if (copy_from_user (&tag, buf, 4)) {
 765                 goto fail1;
 766         }
 767         if (tag != 1) {
 768                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 769                 goto fail0;
 770         }
 771         buf += 4;
 772         len -= 4;
 773
 774         /* NOTE:  audio endpoint extensions not accepted here;
 775          * just don't include the extra bytes.
 776          */
 777
 778         /* full/low speed descriptor, then high speed */
 779         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 780                 goto fail1;
 781         }
 782         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 783                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 784                 goto fail0;
 785         if (len != USB_DT_ENDPOINT_SIZE) {
 786                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 787                         goto fail0;
 788                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 789                                         USB_DT_ENDPOINT_SIZE)) {
 790                         goto fail1;
 791                 }
 792                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 793                                 || data->hs_desc.bDescriptorType
 794                                         != USB_DT_ENDPOINT) {
 795                         DBG(data->dev, "config %s, bad hs length or type\n",
 796                                         data->name);
 797                         goto fail0;
 798                 }
 799         }
 800
 801         spin_lock_irq (&data->dev->lock);
 802         if (data->dev->state == STATE_DEV_UNBOUND) {
 803                 value = -ENOENT;
 804                 goto gone;
 805         } else if ((ep = data->ep) == NULL) {
 806                 value = -ENODEV;
 807                 goto gone;
 808         }
 809         switch (data->dev->gadget->speed) {
 810         case USB_SPEED_LOW:
 811         case USB_SPEED_FULL:
 812                 value = usb_ep_enable (ep, &data->desc);
 813                 if (value == 0)
 814                         data->state = STATE_EP_ENABLED;
 815                 break;
 816 #ifdef  CONFIG_USB_GADGET_DUALSPEED
 817         case USB_SPEED_HIGH:
 818                 /* fails if caller didn't provide that descriptor... */
 819                 value = usb_ep_enable (ep, &data->hs_desc);
 820                 if (value == 0)
 821                         data->state = STATE_EP_ENABLED;
 822                 break;
 823 #endif
 824         default:
 825                 DBG (data->dev, "unconnected, %s init deferred\n",
 826                                 data->name);
 827                 data->state = STATE_EP_DEFER_ENABLE;
 828         }
 829         if (value == 0) {
 830                 fd->f_op = &ep_io_operations;
 831                 value = length;
 832         }
 833 gone:
 834         spin_unlock_irq (&data->dev->lock);
 835         if (value < 0) {
 836 fail:
 837                 data->desc.bDescriptorType = 0;
 838                 data->hs_desc.bDescriptorType = 0;
 839         }
 840         up (&data->lock);
 841         return value;
 842 fail0:
 843         value = -EINVAL;
 844         goto fail;
 845 fail1:
 846         value = -EFAULT;
 847         goto fail;
 848 }
 849
 850 static int
 851 ep_open (struct inode *inode, struct file *fd)
 852 {
 853         struct ep_data          *data = inode->i_private;
 854         int                     value = -EBUSY;
 855
 856         if (down_interruptible (&data->lock) != 0)
 857                 return -EINTR;
 858         spin_lock_irq (&data->dev->lock);
 859         if (data->dev->state == STATE_DEV_UNBOUND)
 860                 value = -ENOENT;
 861         else if (data->state == STATE_EP_DISABLED) {
 862                 value = 0;
 863                 data->state = STATE_EP_READY;
 864                 get_ep (data);
 865                 fd->private_data = data;
 866                 VDEBUG (data->dev, "%s ready\n", data->name);
 867         } else
 868                 DBG (data->dev, "%s state %d\n",
 869                         data->name, data->state);
 870         spin_unlock_irq (&data->dev->lock);
 871         up (&data->lock);
 872         return value;
 873 }
 874
 875 /* used before endpoint configuration */
 876 static const struct file_operations ep_config_operations = {
 877         .owner =        THIS_MODULE,
 878         .llseek =       no_llseek,
 879
 880         .open =         ep_open,
 881         .write =        ep_config,
 882         .release =      ep_release,
 883 };
 884
 885 /*----------------------------------------------------------------------*/
 886
 887 /* EP0 IMPLEMENTATION can be partly in userspace.
 888  *
 889  * Drivers that use this facility receive various events, including
 890  * control requests the kernel doesn't handle.  Drivers that don't
 891  * use this facility may be too simple-minded for real applications.
 892  */
 893
 894 static inline void ep0_readable (struct dev_data *dev)
 895 {
 896         wake_up (&dev->wait);
 897         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 898 }
 899
 900 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 901 {
 902         struct dev_data         *dev = ep->driver_data;
 903
 904         if (req->buf != dev->rbuf) {
 905                 usb_ep_free_buffer (ep, req->buf, req->dma, req->length);
 906                 req->buf = dev->rbuf;
 907                 req->dma = DMA_ADDR_INVALID;
 908         }
 909         req->complete = epio_complete;
 910         dev->setup_out_ready = 0;
 911 }
 912
 913 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 914 {
 915         struct dev_data         *dev = ep->driver_data;
 916         int                     free = 1;
 917
 918         /* for control OUT, data must still get to userspace */
 919         if (!dev->setup_in) {
 920                 dev->setup_out_error = (req->status != 0);
 921                 if (!dev->setup_out_error)
 922                         free = 0;
 923                 dev->setup_out_ready = 1;
 924                 ep0_readable (dev);
 925         } else if (dev->state == STATE_SETUP)
 926                 dev->state = STATE_CONNECTED;
 927
 928         /* clean up as appropriate */
 929         if (free && req->buf != &dev->rbuf)
 930                 clean_req (ep, req);
 931         req->complete = epio_complete;
 932 }
 933
 934 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 935 {
 936         struct dev_data *dev = ep->driver_data;
 937
 938         if (dev->setup_out_ready) {
 939                 DBG (dev, "ep0 request busy!\n");
 940                 return -EBUSY;
 941         }
 942         if (len > sizeof (dev->rbuf))
 943                 req->buf = usb_ep_alloc_buffer (ep, len, &req->dma, GFP_ATOMIC);
 944         if (req->buf == 0) {
 945                 req->buf = dev->rbuf;
 946                 return -ENOMEM;
 947         }
 948         req->complete = ep0_complete;
 949         req->length = len;
 950         req->zero = 0;
 951         return 0;
 952 }
 953
 954 static ssize_t
 955 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 956 {
 957         struct dev_data                 *dev = fd->private_data;
 958         ssize_t                         retval;
 959         enum ep0_state                  state;
 960
 961         spin_lock_irq (&dev->lock);
 962
 963         /* report fd mode change before acting on it */
 964         if (dev->setup_abort) {
 965                 dev->setup_abort = 0;
 966                 retval = -EIDRM;
 967                 goto done;
 968         }
 969
 970         /* control DATA stage */
 971         if ((state = dev->state) == STATE_SETUP) {
 972
 973                 if (dev->setup_in) {            /* stall IN */
 974                         VDEBUG(dev, "ep0in stall\n");
 975                         (void) usb_ep_set_halt (dev->gadget->ep0);
 976                         retval = -EL2HLT;
 977                         dev->state = STATE_CONNECTED;
 978
 979                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
 980                         struct usb_ep           *ep = dev->gadget->ep0;
 981                         struct usb_request      *req = dev->req;
 982
 983                         if ((retval = setup_req (ep, req, 0)) == 0)
 984                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
 985                         dev->state = STATE_CONNECTED;
 986
 987                         /* assume that was SET_CONFIGURATION */
 988                         if (dev->current_config) {
 989                                 unsigned power;
 990 #ifdef  CONFIG_USB_GADGET_DUALSPEED
 991                                 if (dev->gadget->speed == USB_SPEED_HIGH)
 992                                         power = dev->hs_config->bMaxPower;
 993                                 else
 994 #endif
 995                                         power = dev->config->bMaxPower;
 996                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
 997                         }
 998
 999                 } else {                        /* collect OUT data */
1000                         if ((fd->f_flags & O_NONBLOCK) != 0
1001                                         && !dev->setup_out_ready) {
1002                                 retval = -EAGAIN;
1003                                 goto done;
1004                         }
1005                         spin_unlock_irq (&dev->lock);
1006                         retval = wait_event_interruptible (dev->wait,
1007                                         dev->setup_out_ready != 0);
1008
1009                         /* FIXME state could change from under us */
1010                         spin_lock_irq (&dev->lock);
1011                         if (retval)
1012                                 goto done;
1013                         if (dev->setup_out_error)
1014                                 retval = -EIO;
1015                         else {
1016                                 len = min (len, (size_t)dev->req->actual);
1017 // FIXME don't call this with the spinlock held ...
1018                                 if (copy_to_user (buf, dev->req->buf, len))
1019                                         retval = -EFAULT;
1020                                 clean_req (dev->gadget->ep0, dev->req);
1021                                 /* NOTE userspace can't yet choose to stall */
1022                         }
1023                 }
1024                 goto done;
1025         }
1026
1027         /* else normal: return event data */
1028         if (len < sizeof dev->event [0]) {
1029                 retval = -EINVAL;
1030                 goto done;
1031         }
1032         len -= len % sizeof (struct usb_gadgetfs_event);
1033         dev->usermode_setup = 1;
1034
1035 scan:
1036         /* return queued events right away */
1037         if (dev->ev_next != 0) {
1038                 unsigned                i, n;
1039                 int                     tmp = dev->ev_next;
1040
1041                 len = min (len, tmp * sizeof (struct usb_gadgetfs_event));
1042                 n = len / sizeof (struct usb_gadgetfs_event);
1043
1044                 /* ep0 can't deliver events when STATE_SETUP */
1045                 for (i = 0; i < n; i++) {
1046                         if (dev->event [i].type == GADGETFS_SETUP) {
1047                                 len = i + 1;
1048                                 len *= sizeof (struct usb_gadgetfs_event);
1049                                 n = 0;
1050                                 break;
1051                         }
1052                 }
1053                 spin_unlock_irq (&dev->lock);
1054                 if (copy_to_user (buf, &dev->event, len))
1055                         retval = -EFAULT;
1056                 else
1057                         retval = len;
1058                 if (len > 0) {
1059                         len /= sizeof (struct usb_gadgetfs_event);
1060
1061                         /* NOTE this doesn't guard against broken drivers;
1062                          * concurrent ep0 readers may lose events.
1063                          */
1064                         spin_lock_irq (&dev->lock);
1065                         dev->ev_next -= len;
1066                         if (dev->ev_next != 0)
1067                                 memmove (&dev->event, &dev->event [len],
1068                                         sizeof (struct usb_gadgetfs_event)
1069                                                 * (tmp - len));
1070                         if (n == 0)
1071                                 dev->state = STATE_SETUP;
1072                         spin_unlock_irq (&dev->lock);
1073                 }
1074                 return retval;
1075         }
1076         if (fd->f_flags & O_NONBLOCK) {
1077                 retval = -EAGAIN;
1078                 goto done;
1079         }
1080
1081         switch (state) {
1082         default:
1083                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, state);
1084                 retval = -ESRCH;
1085                 break;
1086         case STATE_UNCONNECTED:
1087         case STATE_CONNECTED:
1088                 spin_unlock_irq (&dev->lock);
1089                 DBG (dev, "%s wait\n", __FUNCTION__);
1090
1091                 /* wait for events */
1092                 retval = wait_event_interruptible (dev->wait,
1093                                 dev->ev_next != 0);
1094                 if (retval < 0)
1095                         return retval;
1096                 spin_lock_irq (&dev->lock);
1097                 goto scan;
1098         }
1099
1100 done:
1101         spin_unlock_irq (&dev->lock);
1102         return retval;
1103 }
1104
1105 static struct usb_gadgetfs_event *
1106 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1107 {
1108         struct usb_gadgetfs_event       *event;
1109         unsigned                        i;
1110
1111         switch (type) {
1112         /* these events purge the queue */
1113         case GADGETFS_DISCONNECT:
1114                 if (dev->state == STATE_SETUP)
1115                         dev->setup_abort = 1;
1116                 // FALL THROUGH
1117         case GADGETFS_CONNECT:
1118                 dev->ev_next = 0;
1119                 break;
1120         case GADGETFS_SETUP:            /* previous request timed out */
1121         case GADGETFS_SUSPEND:          /* same effect */
1122                 /* these events can't be repeated */
1123                 for (i = 0; i != dev->ev_next; i++) {
1124                         if (dev->event [i].type != type)
1125                                 continue;
1126                         DBG (dev, "discard old event %d\n", type);
1127                         dev->ev_next--;
1128                         if (i == dev->ev_next)
1129                                 break;
1130                         /* indices start at zero, for simplicity */
1131                         memmove (&dev->event [i], &dev->event [i + 1],
1132                                 sizeof (struct usb_gadgetfs_event)
1133                                         * (dev->ev_next - i));
1134                 }
1135                 break;
1136         default:
1137                 BUG ();
1138         }
1139         event = &dev->event [dev->ev_next++];
1140         BUG_ON (dev->ev_next > N_EVENT);
1141         VDEBUG (dev, "ev %d, next %d\n", type, dev->ev_next);
1142         memset (event, 0, sizeof *event);
1143         event->type = type;
1144         return event;
1145 }
1146
1147 static ssize_t
1148 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1149 {
1150         struct dev_data         *dev = fd->private_data;
1151         ssize_t                 retval = -ESRCH;
1152
1153         spin_lock_irq (&dev->lock);
1154
1155         /* report fd mode change before acting on it */
1156         if (dev->setup_abort) {
1157                 dev->setup_abort = 0;
1158                 retval = -EIDRM;
1159
1160         /* data and/or status stage for control request */
1161         } else if (dev->state == STATE_SETUP) {
1162
1163                 /* IN DATA+STATUS caller makes len <= wLength */
1164                 if (dev->setup_in) {
1165                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1166                         if (retval == 0) {
1167                                 spin_unlock_irq (&dev->lock);
1168                                 if (copy_from_user (dev->req->buf, buf, len))
1169                                         retval = -EFAULT;
1170                                 else {
1171                                         if (len < dev->setup_wLength)
1172                                                 dev->req->zero = 1;
1173                                         retval = usb_ep_queue (
1174                                                 dev->gadget->ep0, dev->req,
1175                                                 GFP_KERNEL);
1176                                 }
1177                                 if (retval < 0) {
1178                                         spin_lock_irq (&dev->lock);
1179                                         clean_req (dev->gadget->ep0, dev->req);
1180                                         spin_unlock_irq (&dev->lock);
1181                                 } else
1182                                         retval = len;
1183
1184                                 return retval;
1185                         }
1186
1187                 /* can stall some OUT transfers */
1188                 } else if (dev->setup_can_stall) {
1189                         VDEBUG(dev, "ep0out stall\n");
1190                         (void) usb_ep_set_halt (dev->gadget->ep0);
1191                         retval = -EL2HLT;
1192                         dev->state = STATE_CONNECTED;
1193                 } else {
1194                         DBG(dev, "bogus ep0out stall!\n");
1195                 }
1196         } else
1197                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state);
1198
1199         spin_unlock_irq (&dev->lock);
1200         return retval;
1201 }
1202
1203 static int
1204 ep0_fasync (int f, struct file *fd, int on)
1205 {
1206         struct dev_data         *dev = fd->private_data;
1207         // caller must F_SETOWN before signal delivery happens
1208         VDEBUG (dev, "%s %s\n", __FUNCTION__, on ? "on" : "off");
1209         return fasync_helper (f, fd, on, &dev->fasync);
1210 }
1211
1212 static struct usb_gadget_driver gadgetfs_driver;
1213
1214 static int
1215 dev_release (struct inode *inode, struct file *fd)
1216 {
1217         struct dev_data         *dev = fd->private_data;
1218
1219         /* closing ep0 === shutdown all */
1220
1221         usb_gadget_unregister_driver (&gadgetfs_driver);
1222
1223         /* at this point "good" hardware has disconnected the
1224          * device from USB; the host won't see it any more.
1225          * alternatively, all host requests will time out.
1226          */
1227
1228         fasync_helper (-1, fd, 0, &dev->fasync);
1229         kfree (dev->buf);
1230         dev->buf = NULL;
1231         put_dev (dev);
1232
1233         /* other endpoints were all decoupled from this device */
1234         dev->state = STATE_DEV_DISABLED;
1235         return 0;
1236 }
1237
1238 static unsigned int
1239 ep0_poll (struct file *fd, poll_table *wait)
1240 {
1241        struct dev_data         *dev = fd->private_data;
1242        int                     mask = 0;
1243
1244        poll_wait(fd, &dev->wait, wait);
1245
1246        spin_lock_irq (&dev->lock);
1247
1248        /* report fd mode change before acting on it */
1249        if (dev->setup_abort) {
1250                dev->setup_abort = 0;
1251                mask = POLLHUP;
1252                goto out;
1253        }
1254
1255        if (dev->state == STATE_SETUP) {
1256                if (dev->setup_in || dev->setup_can_stall)
1257                        mask = POLLOUT;
1258        } else {
1259                if (dev->ev_next != 0)
1260                        mask = POLLIN;
1261        }
1262 out:
1263        spin_unlock_irq(&dev->lock);
1264        return mask;
1265 }
1266
1267 static int dev_ioctl (struct inode *inode, struct file *fd,
1268                 unsigned code, unsigned long value)
1269 {
1270         struct dev_data         *dev = fd->private_data;
1271         struct usb_gadget       *gadget = dev->gadget;
1272
1273         if (gadget->ops->ioctl)
1274                 return gadget->ops->ioctl (gadget, code, value);
1275         return -ENOTTY;
1276 }
1277
1278 /* used after device configuration */
1279 static const struct file_operations ep0_io_operations = {
1280         .owner =        THIS_MODULE,
1281         .llseek =       no_llseek,
1282
1283         .read =         ep0_read,
1284         .write =        ep0_write,
1285         .fasync =       ep0_fasync,
1286         .poll =         ep0_poll,
1287         .ioctl =        dev_ioctl,
1288         .release =      dev_release,
1289 };
1290
1291 /*----------------------------------------------------------------------*/
1292
1293 /* The in-kernel gadget driver handles most ep0 issues, in particular
1294  * enumerating the single configuration (as provided from user space).
1295  *
1296  * Unrecognized ep0 requests may be handled in user space.
1297  */
1298
1299 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1300 static void make_qualifier (struct dev_data *dev)
1301 {
1302         struct usb_qualifier_descriptor         qual;
1303         struct usb_device_descriptor            *desc;
1304
1305         qual.bLength = sizeof qual;
1306         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1307         qual.bcdUSB = __constant_cpu_to_le16 (0x0200);
1308
1309         desc = dev->dev;
1310         qual.bDeviceClass = desc->bDeviceClass;
1311         qual.bDeviceSubClass = desc->bDeviceSubClass;
1312         qual.bDeviceProtocol = desc->bDeviceProtocol;
1313
1314         /* assumes ep0 uses the same value for both speeds ... */
1315         qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
1316
1317         qual.bNumConfigurations = 1;
1318         qual.bRESERVED = 0;
1319
1320         memcpy (dev->rbuf, &qual, sizeof qual);
1321 }
1322 #endif
1323
1324 static int
1325 config_buf (struct dev_data *dev, u8 type, unsigned index)
1326 {
1327         int             len;
1328 #ifdef CONFIG_USB_GADGET_DUALSPEED
1329         int             hs;
1330 #endif
1331
1332         /* only one configuration */
1333         if (index > 0)
1334                 return -EINVAL;
1335
1336 #ifdef CONFIG_USB_GADGET_DUALSPEED
1337         hs = (dev->gadget->speed == USB_SPEED_HIGH);
1338         if (type == USB_DT_OTHER_SPEED_CONFIG)
1339                 hs = !hs;
1340         if (hs) {
1341                 dev->req->buf = dev->hs_config;
1342                 len = le16_to_cpup (&dev->hs_config->wTotalLength);
1343         } else
1344 #endif
1345         {
1346                 dev->req->buf = dev->config;
1347                 len = le16_to_cpup (&dev->config->wTotalLength);
1348         }
1349         ((u8 *)dev->req->buf) [1] = type;
1350         return len;
1351 }
1352
1353 static int
1354 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1355 {
1356         struct dev_data                 *dev = get_gadget_data (gadget);
1357         struct usb_request              *req = dev->req;
1358         int                             value = -EOPNOTSUPP;
1359         struct usb_gadgetfs_event       *event;
1360         u16                             w_value = le16_to_cpu(ctrl->wValue);
1361         u16                             w_length = le16_to_cpu(ctrl->wLength);
1362
1363         spin_lock (&dev->lock);
1364         dev->setup_abort = 0;
1365         if (dev->state == STATE_UNCONNECTED) {
1366                 struct usb_ep   *ep;
1367                 struct ep_data  *data;
1368
1369                 dev->state = STATE_CONNECTED;
1370                 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1371
1372 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1373                 if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) {
1374                         ERROR (dev, "no high speed config??\n");
1375                         return -EINVAL;
1376                 }
1377 #endif  /* CONFIG_USB_GADGET_DUALSPEED */
1378
1379                 INFO (dev, "connected\n");
1380                 event = next_event (dev, GADGETFS_CONNECT);
1381                 event->u.speed = gadget->speed;
1382                 ep0_readable (dev);
1383
1384                 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
1385                         data = ep->driver_data;
1386                         /* ... down_trylock (&data->lock) ... */
1387                         if (data->state != STATE_EP_DEFER_ENABLE)
1388                                 continue;
1389 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1390                         if (gadget->speed == USB_SPEED_HIGH)
1391                                 value = usb_ep_enable (ep, &data->hs_desc);
1392                         else
1393 #endif  /* CONFIG_USB_GADGET_DUALSPEED */
1394                                 value = usb_ep_enable (ep, &data->desc);
1395                         if (value) {
1396                                 ERROR (dev, "deferred %s enable --> %d\n",
1397                                         data->name, value);
1398                                 continue;
1399                         }
1400                         data->state = STATE_EP_ENABLED;
1401                         wake_up (&data->wait);
1402                         DBG (dev, "woke up %s waiters\n", data->name);
1403                 }
1404
1405         /* host may have given up waiting for response.  we can miss control
1406          * requests handled lower down (device/endpoint status and features);
1407          * then ep0_{read,write} will report the wrong status. controller
1408          * driver will have aborted pending i/o.
1409          */
1410         } else if (dev->state == STATE_SETUP)
1411                 dev->setup_abort = 1;
1412
1413         req->buf = dev->rbuf;
1414         req->dma = DMA_ADDR_INVALID;
1415         req->context = NULL;
1416         value = -EOPNOTSUPP;
1417         switch (ctrl->bRequest) {
1418
1419         case USB_REQ_GET_DESCRIPTOR:
1420                 if (ctrl->bRequestType != USB_DIR_IN)
1421                         goto unrecognized;
1422                 switch (w_value >> 8) {
1423
1424                 case USB_DT_DEVICE:
1425                         value = min (w_length, (u16) sizeof *dev->dev);
1426                         req->buf = dev->dev;
1427                         break;
1428 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1429                 case USB_DT_DEVICE_QUALIFIER:
1430                         if (!dev->hs_config)
1431                                 break;
1432                         value = min (w_length, (u16)
1433                                 sizeof (struct usb_qualifier_descriptor));
1434                         make_qualifier (dev);
1435                         break;
1436                 case USB_DT_OTHER_SPEED_CONFIG:
1437                         // FALLTHROUGH
1438 #endif
1439                 case USB_DT_CONFIG:
1440                         value = config_buf (dev,
1441                                         w_value >> 8,
1442                                         w_value & 0xff);
1443                         if (value >= 0)
1444                                 value = min (w_length, (u16) value);
1445                         break;
1446                 case USB_DT_STRING:
1447                         goto unrecognized;
1448
1449                 default:                // all others are errors
1450                         break;
1451                 }
1452                 break;
1453
1454         /* currently one config, two speeds */
1455         case USB_REQ_SET_CONFIGURATION:
1456                 if (ctrl->bRequestType != 0)
1457                         break;
1458                 if (0 == (u8) w_value) {
1459                         value = 0;
1460                         dev->current_config = 0;
1461                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1462                         // user mode expected to disable endpoints
1463                 } else {
1464                         u8      config, power;
1465 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1466                         if (gadget->speed == USB_SPEED_HIGH) {
1467                                 config = dev->hs_config->bConfigurationValue;
1468                                 power = dev->hs_config->bMaxPower;
1469                         } else
1470 #endif
1471                         {
1472                                 config = dev->config->bConfigurationValue;
1473                                 power = dev->config->bMaxPower;
1474                         }
1475
1476                         if (config == (u8) w_value) {
1477                                 value = 0;
1478                                 dev->current_config = config;
1479                                 usb_gadget_vbus_draw(gadget, 2 * power);
1480                         }
1481                 }
1482
1483                 /* report SET_CONFIGURATION like any other control request,
1484                  * except that usermode may not stall this.  the next
1485                  * request mustn't be allowed start until this finishes:
1486                  * endpoints and threads set up, etc.
1487                  *
1488                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1489                  * has bad/racey automagic that prevents synchronizing here.
1490                  * even kernel mode drivers often miss them.
1491                  */
1492                 if (value == 0) {
1493                         INFO (dev, "configuration #%d\n", dev->current_config);
1494                         if (dev->usermode_setup) {
1495                                 dev->setup_can_stall = 0;
1496                                 goto delegate;
1497                         }
1498                 }
1499                 break;
1500
1501 #ifndef CONFIG_USB_GADGETFS_PXA2XX
1502         /* PXA automagically handles this request too */
1503         case USB_REQ_GET_CONFIGURATION:
1504                 if (ctrl->bRequestType != 0x80)
1505                         break;
1506                 *(u8 *)req->buf = dev->current_config;
1507                 value = min (w_length, (u16) 1);
1508                 break;
1509 #endif
1510
1511         default:
1512 unrecognized:
1513                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1514                         dev->usermode_setup ? "delegate" : "fail",
1515                         ctrl->bRequestType, ctrl->bRequest,
1516                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1517
1518                 /* if there's an ep0 reader, don't stall */
1519                 if (dev->usermode_setup) {
1520                         dev->setup_can_stall = 1;
1521 delegate:
1522                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1523                                                 ? 1 : 0;
1524                         dev->setup_wLength = w_length;
1525                         dev->setup_out_ready = 0;
1526                         dev->setup_out_error = 0;
1527                         value = 0;
1528
1529                         /* read DATA stage for OUT right away */
1530                         if (unlikely (!dev->setup_in && w_length)) {
1531                                 value = setup_req (gadget->ep0, dev->req,
1532                                                         w_length);
1533                                 if (value < 0)
1534                                         break;
1535                                 value = usb_ep_queue (gadget->ep0, dev->req,
1536                                                         GFP_ATOMIC);
1537                                 if (value < 0) {
1538                                         clean_req (gadget->ep0, dev->req);
1539                                         break;
1540                                 }
1541
1542                                 /* we can't currently stall these */
1543                                 dev->setup_can_stall = 0;
1544                         }
1545
1546                         /* state changes when reader collects event */
1547                         event = next_event (dev, GADGETFS_SETUP);
1548                         event->u.setup = *ctrl;
1549                         ep0_readable (dev);
1550                         spin_unlock (&dev->lock);
1551                         return 0;
1552                 }
1553         }
1554
1555         /* proceed with data transfer and status phases? */
1556         if (value >= 0 && dev->state != STATE_SETUP) {
1557                 req->length = value;
1558                 req->zero = value < w_length;
1559                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1560                 if (value < 0) {
1561                         DBG (dev, "ep_queue --> %d\n", value);
1562                         req->status = 0;
1563                 }
1564         }
1565
1566         /* device stalls when value < 0 */
1567         spin_unlock (&dev->lock);
1568         return value;
1569 }
1570
1571 static void destroy_ep_files (struct dev_data *dev)
1572 {
1573         struct list_head        *entry, *tmp;
1574
1575         DBG (dev, "%s %d\n", __FUNCTION__, dev->state);
1576
1577         /* dev->state must prevent interference */
1578 restart:
1579         spin_lock_irq (&dev->lock);
1580         list_for_each_safe (entry, tmp, &dev->epfiles) {
1581                 struct ep_data  *ep;
1582                 struct inode    *parent;
1583                 struct dentry   *dentry;
1584
1585                 /* break link to FS */
1586                 ep = list_entry (entry, struct ep_data, epfiles);
1587                 list_del_init (&ep->epfiles);
1588                 dentry = ep->dentry;
1589                 ep->dentry = NULL;
1590                 parent = dentry->d_parent->d_inode;
1591
1592                 /* break link to controller */
1593                 if (ep->state == STATE_EP_ENABLED)
1594                         (void) usb_ep_disable (ep->ep);
1595                 ep->state = STATE_EP_UNBOUND;
1596                 usb_ep_free_request (ep->ep, ep->req);
1597                 ep->ep = NULL;
1598                 wake_up (&ep->wait);
1599                 put_ep (ep);
1600
1601                 spin_unlock_irq (&dev->lock);
1602
1603                 /* break link to dcache */
1604                 mutex_lock (&parent->i_mutex);
1605                 d_delete (dentry);
1606                 dput (dentry);
1607                 mutex_unlock (&parent->i_mutex);
1608
1609                 /* fds may still be open */
1610                 goto restart;
1611         }
1612         spin_unlock_irq (&dev->lock);
1613 }
1614
1615
1616 static struct inode *
1617 gadgetfs_create_file (struct super_block *sb, char const *name,
1618                 void *data, const struct file_operations *fops,
1619                 struct dentry **dentry_p);
1620
1621 static int activate_ep_files (struct dev_data *dev)
1622 {
1623         struct usb_ep   *ep;
1624         struct ep_data  *data;
1625
1626         gadget_for_each_ep (ep, dev->gadget) {
1627
1628                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1629                 if (!data)
1630                         goto enomem0;
1631                 data->state = STATE_EP_DISABLED;
1632                 init_MUTEX (&data->lock);
1633                 init_waitqueue_head (&data->wait);
1634
1635                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1636                 atomic_set (&data->count, 1);
1637                 data->dev = dev;
1638                 get_dev (dev);
1639
1640                 data->ep = ep;
1641                 ep->driver_data = data;
1642
1643                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1644                 if (!data->req)
1645                         goto enomem1;
1646
1647                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1648                                 data, &ep_config_operations,
1649                                 &data->dentry);
1650                 if (!data->inode)
1651                         goto enomem2;
1652                 list_add_tail (&data->epfiles, &dev->epfiles);
1653         }
1654         return 0;
1655
1656 enomem2:
1657         usb_ep_free_request (ep, data->req);
1658 enomem1:
1659         put_dev (dev);
1660         kfree (data);
1661 enomem0:
1662         DBG (dev, "%s enomem\n", __FUNCTION__);
1663         destroy_ep_files (dev);
1664         return -ENOMEM;
1665 }
1666
1667 static void
1668 gadgetfs_unbind (struct usb_gadget *gadget)
1669 {
1670         struct dev_data         *dev = get_gadget_data (gadget);
1671
1672         DBG (dev, "%s\n", __FUNCTION__);
1673
1674         spin_lock_irq (&dev->lock);
1675         dev->state = STATE_DEV_UNBOUND;
1676         spin_unlock_irq (&dev->lock);
1677
1678         destroy_ep_files (dev);
1679         gadget->ep0->driver_data = NULL;
1680         set_gadget_data (gadget, NULL);
1681
1682         /* we've already been disconnected ... no i/o is active */
1683         if (dev->req)
1684                 usb_ep_free_request (gadget->ep0, dev->req);
1685         DBG (dev, "%s done\n", __FUNCTION__);
1686         put_dev (dev);
1687 }
1688
1689 static struct dev_data          *the_device;
1690
1691 static int
1692 gadgetfs_bind (struct usb_gadget *gadget)
1693 {
1694         struct dev_data         *dev = the_device;
1695
1696         if (!dev)
1697                 return -ESRCH;
1698         if (0 != strcmp (CHIP, gadget->name)) {
1699                 printk (KERN_ERR "%s expected %s controller not %s\n",
1700                         shortname, CHIP, gadget->name);
1701                 return -ENODEV;
1702         }
1703
1704         set_gadget_data (gadget, dev);
1705         dev->gadget = gadget;
1706         gadget->ep0->driver_data = dev;
1707         dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1708
1709         /* preallocate control response and buffer */
1710         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1711         if (!dev->req)
1712                 goto enomem;
1713         dev->req->context = NULL;
1714         dev->req->complete = epio_complete;
1715
1716         if (activate_ep_files (dev) < 0)
1717                 goto enomem;
1718
1719         INFO (dev, "bound to %s driver\n", gadget->name);
1720         dev->state = STATE_UNCONNECTED;
1721         get_dev (dev);
1722         return 0;
1723
1724 enomem:
1725         gadgetfs_unbind (gadget);
1726         return -ENOMEM;
1727 }
1728
1729 static void
1730 gadgetfs_disconnect (struct usb_gadget *gadget)
1731 {
1732         struct dev_data         *dev = get_gadget_data (gadget);
1733
1734         spin_lock (&dev->lock);
1735         if (dev->state == STATE_UNCONNECTED) {
1736                 DBG (dev, "already unconnected\n");
1737                 goto exit;
1738         }
1739         dev->state = STATE_UNCONNECTED;
1740
1741         INFO (dev, "disconnected\n");
1742         next_event (dev, GADGETFS_DISCONNECT);
1743         ep0_readable (dev);
1744 exit:
1745         spin_unlock (&dev->lock);
1746 }
1747
1748 static void
1749 gadgetfs_suspend (struct usb_gadget *gadget)
1750 {
1751         struct dev_data         *dev = get_gadget_data (gadget);
1752
1753         INFO (dev, "suspended from state %d\n", dev->state);
1754         spin_lock (&dev->lock);
1755         switch (dev->state) {
1756         case STATE_SETUP:               // VERY odd... host died??
1757         case STATE_CONNECTED:
1758         case STATE_UNCONNECTED:
1759                 next_event (dev, GADGETFS_SUSPEND);
1760                 ep0_readable (dev);
1761                 /* FALLTHROUGH */
1762         default:
1763                 break;
1764         }
1765         spin_unlock (&dev->lock);
1766 }
1767
1768 static struct usb_gadget_driver gadgetfs_driver = {
1769 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1770         .speed          = USB_SPEED_HIGH,
1771 #else
1772         .speed          = USB_SPEED_FULL,
1773 #endif
1774         .function       = (char *) driver_desc,
1775         .bind           = gadgetfs_bind,
1776         .unbind         = gadgetfs_unbind,
1777         .setup          = gadgetfs_setup,
1778         .disconnect     = gadgetfs_disconnect,
1779         .suspend        = gadgetfs_suspend,
1780
1781         .driver         = {
1782                 .name           = (char *) shortname,
1783         },
1784 };
1785
1786 /*----------------------------------------------------------------------*/
1787
1788 static void gadgetfs_nop(struct usb_gadget *arg) { }
1789
1790 static int gadgetfs_probe (struct usb_gadget *gadget)
1791 {
1792         CHIP = gadget->name;
1793         return -EISNAM;
1794 }
1795
1796 static struct usb_gadget_driver probe_driver = {
1797         .speed          = USB_SPEED_HIGH,
1798         .bind           = gadgetfs_probe,
1799         .unbind         = gadgetfs_nop,
1800         .setup          = (void *)gadgetfs_nop,
1801         .disconnect     = gadgetfs_nop,
1802         .driver         = {
1803                 .name           = "nop",
1804         },
1805 };
1806
1807
1808 /* DEVICE INITIALIZATION
1809  *
1810  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1811  *     status = write (fd, descriptors, sizeof descriptors)
1812  *
1813  * That write establishes the device configuration, so the kernel can
1814  * bind to the controller ... guaranteeing it can handle enumeration
1815  * at all necessary speeds.  Descriptor order is:
1816  *
1817  * . message tag (u32, host order) ... for now, must be zero; it
1818  *      would change to support features like multi-config devices
1819  * . full/low speed config ... all wTotalLength bytes (with interface,
1820  *      class, altsetting, endpoint, and other descriptors)
1821  * . high speed config ... all descriptors, for high speed operation;
1822  *      this one's optional except for high-speed hardware
1823  * . device descriptor
1824  *
1825  * Endpoints are not yet enabled. Drivers may want to immediately
1826  * initialize them, using the /dev/gadget/ep* files that are available
1827  * as soon as the kernel sees the configuration, or they can wait
1828  * until device configuration and interface altsetting changes create
1829  * the need to configure (or unconfigure) them.
1830  *
1831  * After initialization, the device stays active for as long as that
1832  * $CHIP file is open.  Events may then be read from that descriptor,
1833  * such as configuration notifications.  More complex drivers will handle
1834  * some control requests in user space.
1835  */
1836
1837 static int is_valid_config (struct usb_config_descriptor *config)
1838 {
1839         return config->bDescriptorType == USB_DT_CONFIG
1840                 && config->bLength == USB_DT_CONFIG_SIZE
1841                 && config->bConfigurationValue != 0
1842                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1843                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1844         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1845         /* FIXME check lengths: walk to end */
1846 }
1847
1848 static ssize_t
1849 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1850 {
1851         struct dev_data         *dev = fd->private_data;
1852         ssize_t                 value = len, length = len;
1853         unsigned                total;
1854         u32                     tag;
1855         char                    *kbuf;
1856
1857         if (dev->state != STATE_OPENED)
1858                 return -EEXIST;
1859
1860         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1861                 return -EINVAL;
1862
1863         /* we might need to change message format someday */
1864         if (copy_from_user (&tag, buf, 4))
1865                 return -EFAULT;
1866         if (tag != 0)
1867                 return -EINVAL;
1868         buf += 4;
1869         length -= 4;
1870
1871         kbuf = kmalloc (length, SLAB_KERNEL);
1872         if (!kbuf)
1873                 return -ENOMEM;
1874         if (copy_from_user (kbuf, buf, length)) {
1875                 kfree (kbuf);
1876                 return -EFAULT;
1877         }
1878
1879         spin_lock_irq (&dev->lock);
1880         value = -EINVAL;
1881         if (dev->buf)
1882                 goto fail;
1883         dev->buf = kbuf;
1884
1885         /* full or low speed config */
1886         dev->config = (void *) kbuf;
1887         total = le16_to_cpup (&dev->config->wTotalLength);
1888         if (!is_valid_config (dev->config) || total >= length)
1889                 goto fail;
1890         kbuf += total;
1891         length -= total;
1892
1893         /* optional high speed config */
1894         if (kbuf [1] == USB_DT_CONFIG) {
1895                 dev->hs_config = (void *) kbuf;
1896                 total = le16_to_cpup (&dev->hs_config->wTotalLength);
1897                 if (!is_valid_config (dev->hs_config) || total >= length)
1898                         goto fail;
1899                 kbuf += total;
1900                 length -= total;
1901         }
1902
1903         /* could support multiple configs, using another encoding! */
1904
1905         /* device descriptor (tweaked for paranoia) */
1906         if (length != USB_DT_DEVICE_SIZE)
1907                 goto fail;
1908         dev->dev = (void *)kbuf;
1909         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1910                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1911                         || dev->dev->bNumConfigurations != 1)
1912                 goto fail;
1913         dev->dev->bNumConfigurations = 1;
1914         dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200);
1915
1916         /* triggers gadgetfs_bind(); then we can enumerate. */
1917         spin_unlock_irq (&dev->lock);
1918         value = usb_gadget_register_driver (&gadgetfs_driver);
1919         if (value != 0) {
1920                 kfree (dev->buf);
1921                 dev->buf = NULL;
1922         } else {
1923                 /* at this point "good" hardware has for the first time
1924                  * let the USB the host see us.  alternatively, if users
1925                  * unplug/replug that will clear all the error state.
1926                  *
1927                  * note:  everything running before here was guaranteed
1928                  * to choke driver model style diagnostics.  from here
1929                  * on, they can work ... except in cleanup paths that
1930                  * kick in after the ep0 descriptor is closed.
1931                  */
1932                 fd->f_op = &ep0_io_operations;
1933                 value = len;
1934         }
1935         return value;
1936
1937 fail:
1938         spin_unlock_irq (&dev->lock);
1939         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __FUNCTION__, value, dev);
1940         kfree (dev->buf);
1941         dev->buf = NULL;
1942         return value;
1943 }
1944
1945 static int
1946 dev_open (struct inode *inode, struct file *fd)
1947 {
1948         struct dev_data         *dev = inode->i_private;
1949         int                     value = -EBUSY;
1950
1951         if (dev->state == STATE_DEV_DISABLED) {
1952                 dev->ev_next = 0;
1953                 dev->state = STATE_OPENED;
1954                 fd->private_data = dev;
1955                 get_dev (dev);
1956                 value = 0;
1957         }
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         .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