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   1 /*
   2  * inode.c -- user mode filesystem api for usb gadget controllers
   3  *
   4  * Copyright (C) 2003-2004 David Brownell
   5  * Copyright (C) 2003 Agilent Technologies
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22
  23 /* #define VERBOSE_DEBUG */
  24
  25 #include <linux/init.h>
  26 #include <linux/module.h>
  27 #include <linux/fs.h>
  28 #include <linux/pagemap.h>
  29 #include <linux/uts.h>
  30 #include <linux/wait.h>
  31 #include <linux/compiler.h>
  32 #include <asm/uaccess.h>
  33 #include <linux/slab.h>
  34 #include <linux/poll.h>
  35
  36 #include <linux/device.h>
  37 #include <linux/moduleparam.h>
  38
  39 #include <linux/usb/gadgetfs.h>
  40 #include <linux/usb/gadget.h>
  41
  42
  43 /*
  44  * The gadgetfs API maps each endpoint to a file descriptor so that you
  45  * can use standard synchronous read/write calls for I/O.  There's some
  46  * O_NONBLOCK and O_ASYNC/FASYNC style i/o support.  Example usermode
  47  * drivers show how this works in practice.  You can also use AIO to
  48  * eliminate I/O gaps between requests, to help when streaming data.
  49  *
  50  * Key parts that must be USB-specific are protocols defining how the
  51  * read/write operations relate to the hardware state machines.  There
  52  * are two types of files.  One type is for the device, implementing ep0.
  53  * The other type is for each IN or OUT endpoint.  In both cases, the
  54  * user mode driver must configure the hardware before using it.
  55  *
  56  * - First, dev_config() is called when /dev/gadget/$CHIP is configured
  57  *   (by writing configuration and device descriptors).  Afterwards it
  58  *   may serve as a source of device events, used to handle all control
  59  *   requests other than basic enumeration.
  60  *
  61  * - Then, after a SET_CONFIGURATION control request, ep_config() is
  62  *   called when each /dev/gadget/ep* file is configured (by writing
  63  *   endpoint descriptors).  Afterwards these files are used to write()
  64  *   IN data or to read() OUT data.  To halt the endpoint, a "wrong
  65  *   direction" request is issued (like reading an IN endpoint).
  66  *
  67  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
  68  * not possible on all hardware.  For example, precise fault handling with
  69  * respect to data left in endpoint fifos after aborted operations; or
  70  * selective clearing of endpoint halts, to implement SET_INTERFACE.
  71  */
  72
  73 #define DRIVER_DESC     "USB Gadget filesystem"
  74 #define DRIVER_VERSION  "24 Aug 2004"
  75
  76 static const char driver_desc [] = DRIVER_DESC;
  77 static const char shortname [] = "gadgetfs";
  78
  79 MODULE_DESCRIPTION (DRIVER_DESC);
  80 MODULE_AUTHOR ("David Brownell");
  81 MODULE_LICENSE ("GPL");
  82
  83
  84 /*----------------------------------------------------------------------*/
  85
  86 #define GADGETFS_MAGIC          0xaee71ee7
  87 #define DMA_ADDR_INVALID        (~(dma_addr_t)0)
  88
  89 /* /dev/gadget/$CHIP represents ep0 and the whole device */
  90 enum ep0_state {
  91         /* DISBLED is the initial state.
  92          */
  93         STATE_DEV_DISABLED = 0,
  94
  95         /* Only one open() of /dev/gadget/$CHIP; only one file tracks
  96          * ep0/device i/o modes and binding to the controller.  Driver
  97          * must always write descriptors to initialize the device, then
  98          * the device becomes UNCONNECTED until enumeration.
  99          */
 100         STATE_DEV_OPENED,
 101
 102         /* From then on, ep0 fd is in either of two basic modes:
 103          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
 104          * - SETUP: read/write will transfer control data and succeed;
 105          *   or if "wrong direction", performs protocol stall
 106          */
 107         STATE_DEV_UNCONNECTED,
 108         STATE_DEV_CONNECTED,
 109         STATE_DEV_SETUP,
 110
 111         /* UNBOUND means the driver closed ep0, so the device won't be
 112          * accessible again (DEV_DISABLED) until all fds are closed.
 113          */
 114         STATE_DEV_UNBOUND,
 115 };
 116
 117 /* enough for the whole queue: most events invalidate others */
 118 #define N_EVENT                 5
 119
 120 struct dev_data {
 121         spinlock_t                      lock;
 122         atomic_t                        count;
 123         enum ep0_state                  state;          /* P: lock */
 124         struct usb_gadgetfs_event       event [N_EVENT];
 125         unsigned                        ev_next;
 126         struct fasync_struct            *fasync;
 127         u8                              current_config;
 128
 129         /* drivers reading ep0 MUST handle control requests (SETUP)
 130          * reported that way; else the host will time out.
 131          */
 132         unsigned                        usermode_setup : 1,
 133                                         setup_in : 1,
 134                                         setup_can_stall : 1,
 135                                         setup_out_ready : 1,
 136                                         setup_out_error : 1,
 137                                         setup_abort : 1;
 138         unsigned                        setup_wLength;
 139
 140         /* the rest is basically write-once */
 141         struct usb_config_descriptor    *config, *hs_config;
 142         struct usb_device_descriptor    *dev;
 143         struct usb_request              *req;
 144         struct usb_gadget               *gadget;
 145         struct list_head                epfiles;
 146         void                            *buf;
 147         wait_queue_head_t               wait;
 148         struct super_block              *sb;
 149         struct dentry                   *dentry;
 150
 151         /* except this scratch i/o buffer for ep0 */
 152         u8                              rbuf [256];
 153 };
 154
 155 static inline void get_dev (struct dev_data *data)
 156 {
 157         atomic_inc (&data->count);
 158 }
 159
 160 static void put_dev (struct dev_data *data)
 161 {
 162         if (likely (!atomic_dec_and_test (&data->count)))
 163                 return;
 164         /* needs no more cleanup */
 165         BUG_ON (waitqueue_active (&data->wait));
 166         kfree (data);
 167 }
 168
 169 static struct dev_data *dev_new (void)
 170 {
 171         struct dev_data         *dev;
 172
 173         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 174         if (!dev)
 175                 return NULL;
 176         dev->state = STATE_DEV_DISABLED;
 177         atomic_set (&dev->count, 1);
 178         spin_lock_init (&dev->lock);
 179         INIT_LIST_HEAD (&dev->epfiles);
 180         init_waitqueue_head (&dev->wait);
 181         return dev;
 182 }
 183
 184 /*----------------------------------------------------------------------*/
 185
 186 /* other /dev/gadget/$ENDPOINT files represent endpoints */
 187 enum ep_state {
 188         STATE_EP_DISABLED = 0,
 189         STATE_EP_READY,
 190         STATE_EP_ENABLED,
 191         STATE_EP_UNBOUND,
 192 };
 193
 194 struct ep_data {
 195         struct semaphore                lock;
 196         enum ep_state                   state;
 197         atomic_t                        count;
 198         struct dev_data                 *dev;
 199         /* must hold dev->lock before accessing ep or req */
 200         struct usb_ep                   *ep;
 201         struct usb_request              *req;
 202         ssize_t                         status;
 203         char                            name [16];
 204         struct usb_endpoint_descriptor  desc, hs_desc;
 205         struct list_head                epfiles;
 206         wait_queue_head_t               wait;
 207         struct dentry                   *dentry;
 208         struct inode                    *inode;
 209 };
 210
 211 static inline void get_ep (struct ep_data *data)
 212 {
 213         atomic_inc (&data->count);
 214 }
 215
 216 static void put_ep (struct ep_data *data)
 217 {
 218         if (likely (!atomic_dec_and_test (&data->count)))
 219                 return;
 220         put_dev (data->dev);
 221         /* needs no more cleanup */
 222         BUG_ON (!list_empty (&data->epfiles));
 223         BUG_ON (waitqueue_active (&data->wait));
 224         kfree (data);
 225 }
 226
 227 /*----------------------------------------------------------------------*/
 228
 229 /* most "how to use the hardware" policy choices are in userspace:
 230  * mapping endpoint roles (which the driver needs) to the capabilities
 231  * which the usb controller has.  most of those capabilities are exposed
 232  * implicitly, starting with the driver name and then endpoint names.
 233  */
 234
 235 static const char *CHIP;
 236
 237 /*----------------------------------------------------------------------*/
 238
 239 /* NOTE:  don't use dev_printk calls before binding to the gadget
 240  * at the end of ep0 configuration, or after unbind.
 241  */
 242
 243 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
 244 #define xprintk(d,level,fmt,args...) \
 245         printk(level "%s: " fmt , shortname , ## args)
 246
 247 #ifdef DEBUG
 248 #define DBG(dev,fmt,args...) \
 249         xprintk(dev , KERN_DEBUG , fmt , ## args)
 250 #else
 251 #define DBG(dev,fmt,args...) \
 252         do { } while (0)
 253 #endif /* DEBUG */
 254
 255 #ifdef VERBOSE_DEBUG
 256 #define VDEBUG  DBG
 257 #else
 258 #define VDEBUG(dev,fmt,args...) \
 259         do { } while (0)
 260 #endif /* DEBUG */
 261
 262 #define ERROR(dev,fmt,args...) \
 263         xprintk(dev , KERN_ERR , fmt , ## args)
 264 #define WARN(dev,fmt,args...) \
 265         xprintk(dev , KERN_WARNING , fmt , ## args)
 266 #define INFO(dev,fmt,args...) \
 267         xprintk(dev , KERN_INFO , fmt , ## args)
 268
 269
 270 /*----------------------------------------------------------------------*/
 271
 272 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 273  *
 274  * After opening, configure non-control endpoints.  Then use normal
 275  * stream read() and write() requests; and maybe ioctl() to get more
 276  * precise FIFO status when recovering from cancellation.
 277  */
 278
 279 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 280 {
 281         struct ep_data  *epdata = ep->driver_data;
 282
 283         if (!req->context)
 284                 return;
 285         if (req->status)
 286                 epdata->status = req->status;
 287         else
 288                 epdata->status = req->actual;
 289         complete ((struct completion *)req->context);
 290 }
 291
 292 /* tasklock endpoint, returning when it's connected.
 293  * still need dev->lock to use epdata->ep.
 294  */
 295 static int
 296 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
 297 {
 298         int     val;
 299
 300         if (f_flags & O_NONBLOCK) {
 301                 if (down_trylock (&epdata->lock) != 0)
 302                         goto nonblock;
 303                 if (epdata->state != STATE_EP_ENABLED) {
 304                         up (&epdata->lock);
 305 nonblock:
 306                         val = -EAGAIN;
 307                 } else
 308                         val = 0;
 309                 return val;
 310         }
 311
 312         if ((val = down_interruptible (&epdata->lock)) < 0)
 313                 return val;
 314
 315         switch (epdata->state) {
 316         case STATE_EP_ENABLED:
 317                 break;
 318         // case STATE_EP_DISABLED:              /* "can't happen" */
 319         // case STATE_EP_READY:                 /* "can't happen" */
 320         default:                                /* error! */
 321                 pr_debug ("%s: ep %p not available, state %d\n",
 322                                 shortname, epdata, epdata->state);
 323                 // FALLTHROUGH
 324         case STATE_EP_UNBOUND:                  /* clean disconnect */
 325                 val = -ENODEV;
 326                 up (&epdata->lock);
 327         }
 328         return val;
 329 }
 330
 331 static ssize_t
 332 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 333 {
 334         DECLARE_COMPLETION_ONSTACK (done);
 335         int value;
 336
 337         spin_lock_irq (&epdata->dev->lock);
 338         if (likely (epdata->ep != NULL)) {
 339                 struct usb_request      *req = epdata->req;
 340
 341                 req->context = &done;
 342                 req->complete = epio_complete;
 343                 req->buf = buf;
 344                 req->length = len;
 345                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 346         } else
 347                 value = -ENODEV;
 348         spin_unlock_irq (&epdata->dev->lock);
 349
 350         if (likely (value == 0)) {
 351                 value = wait_event_interruptible (done.wait, done.done);
 352                 if (value != 0) {
 353                         spin_lock_irq (&epdata->dev->lock);
 354                         if (likely (epdata->ep != NULL)) {
 355                                 DBG (epdata->dev, "%s i/o interrupted\n",
 356                                                 epdata->name);
 357                                 usb_ep_dequeue (epdata->ep, epdata->req);
 358                                 spin_unlock_irq (&epdata->dev->lock);
 359
 360                                 wait_event (done.wait, done.done);
 361                                 if (epdata->status == -ECONNRESET)
 362                                         epdata->status = -EINTR;
 363                         } else {
 364                                 spin_unlock_irq (&epdata->dev->lock);
 365
 366                                 DBG (epdata->dev, "endpoint gone\n");
 367                                 epdata->status = -ENODEV;
 368                         }
 369                 }
 370                 return epdata->status;
 371         }
 372         return value;
 373 }
 374
 375
 376 /* handle a synchronous OUT bulk/intr/iso transfer */
 377 static ssize_t
 378 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 379 {
 380         struct ep_data          *data = fd->private_data;
 381         void                    *kbuf;
 382         ssize_t                 value;
 383
 384         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 385                 return value;
 386
 387         /* halt any endpoint by doing a "wrong direction" i/o call */
 388         if (data->desc.bEndpointAddress & USB_DIR_IN) {
 389                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 390                                 == USB_ENDPOINT_XFER_ISOC)
 391                         return -EINVAL;
 392                 DBG (data->dev, "%s halt\n", data->name);
 393                 spin_lock_irq (&data->dev->lock);
 394                 if (likely (data->ep != NULL))
 395                         usb_ep_set_halt (data->ep);
 396                 spin_unlock_irq (&data->dev->lock);
 397                 up (&data->lock);
 398                 return -EBADMSG;
 399         }
 400
 401         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
 402
 403         value = -ENOMEM;
 404         kbuf = kmalloc (len, GFP_KERNEL);
 405         if (unlikely (!kbuf))
 406                 goto free1;
 407
 408         value = ep_io (data, kbuf, len);
 409         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
 410                 data->name, len, (int) value);
 411         if (value >= 0 && copy_to_user (buf, kbuf, value))
 412                 value = -EFAULT;
 413
 414 free1:
 415         up (&data->lock);
 416         kfree (kbuf);
 417         return value;
 418 }
 419
 420 /* handle a synchronous IN bulk/intr/iso transfer */
 421 static ssize_t
 422 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 423 {
 424         struct ep_data          *data = fd->private_data;
 425         void                    *kbuf;
 426         ssize_t                 value;
 427
 428         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 429                 return value;
 430
 431         /* halt any endpoint by doing a "wrong direction" i/o call */
 432         if (!(data->desc.bEndpointAddress & USB_DIR_IN)) {
 433                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 434                                 == USB_ENDPOINT_XFER_ISOC)
 435                         return -EINVAL;
 436                 DBG (data->dev, "%s halt\n", data->name);
 437                 spin_lock_irq (&data->dev->lock);
 438                 if (likely (data->ep != NULL))
 439                         usb_ep_set_halt (data->ep);
 440                 spin_unlock_irq (&data->dev->lock);
 441                 up (&data->lock);
 442                 return -EBADMSG;
 443         }
 444
 445         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
 446
 447         value = -ENOMEM;
 448         kbuf = kmalloc (len, GFP_KERNEL);
 449         if (!kbuf)
 450                 goto free1;
 451         if (copy_from_user (kbuf, buf, len)) {
 452                 value = -EFAULT;
 453                 goto free1;
 454         }
 455
 456         value = ep_io (data, kbuf, len);
 457         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
 458                 data->name, len, (int) value);
 459 free1:
 460         up (&data->lock);
 461         kfree (kbuf);
 462         return value;
 463 }
 464
 465 static int
 466 ep_release (struct inode *inode, struct file *fd)
 467 {
 468         struct ep_data          *data = fd->private_data;
 469         int value;
 470
 471         if ((value = down_interruptible(&data->lock)) < 0)
 472                 return value;
 473
 474         /* clean up if this can be reopened */
 475         if (data->state != STATE_EP_UNBOUND) {
 476                 data->state = STATE_EP_DISABLED;
 477                 data->desc.bDescriptorType = 0;
 478                 data->hs_desc.bDescriptorType = 0;
 479                 usb_ep_disable(data->ep);
 480         }
 481         up (&data->lock);
 482         put_ep (data);
 483         return 0;
 484 }
 485
 486 static int ep_ioctl (struct inode *inode, struct file *fd,
 487                 unsigned code, unsigned long value)
 488 {
 489         struct ep_data          *data = fd->private_data;
 490         int                     status;
 491
 492         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 493                 return status;
 494
 495         spin_lock_irq (&data->dev->lock);
 496         if (likely (data->ep != NULL)) {
 497                 switch (code) {
 498                 case GADGETFS_FIFO_STATUS:
 499                         status = usb_ep_fifo_status (data->ep);
 500                         break;
 501                 case GADGETFS_FIFO_FLUSH:
 502                         usb_ep_fifo_flush (data->ep);
 503                         break;
 504                 case GADGETFS_CLEAR_HALT:
 505                         status = usb_ep_clear_halt (data->ep);
 506                         break;
 507                 default:
 508                         status = -ENOTTY;
 509                 }
 510         } else
 511                 status = -ENODEV;
 512         spin_unlock_irq (&data->dev->lock);
 513         up (&data->lock);
 514         return status;
 515 }
 516
 517 /*----------------------------------------------------------------------*/
 518
 519 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 520
 521 struct kiocb_priv {
 522         struct usb_request      *req;
 523         struct ep_data          *epdata;
 524         void                    *buf;
 525         const struct iovec      *iv;
 526         unsigned long           nr_segs;
 527         unsigned                actual;
 528 };
 529
 530 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
 531 {
 532         struct kiocb_priv       *priv = iocb->private;
 533         struct ep_data          *epdata;
 534         int                     value;
 535
 536         local_irq_disable();
 537         epdata = priv->epdata;
 538         // spin_lock(&epdata->dev->lock);
 539         kiocbSetCancelled(iocb);
 540         if (likely(epdata && epdata->ep && priv->req))
 541                 value = usb_ep_dequeue (epdata->ep, priv->req);
 542         else
 543                 value = -EINVAL;
 544         // spin_unlock(&epdata->dev->lock);
 545         local_irq_enable();
 546
 547         aio_put_req(iocb);
 548         return value;
 549 }
 550
 551 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
 552 {
 553         struct kiocb_priv       *priv = iocb->private;
 554         ssize_t                 len, total;
 555         void                    *to_copy;
 556         int                     i;
 557
 558         /* we "retry" to get the right mm context for this: */
 559
 560         /* copy stuff into user buffers */
 561         total = priv->actual;
 562         len = 0;
 563         to_copy = priv->buf;
 564         for (i=0; i < priv->nr_segs; i++) {
 565                 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
 566
 567                 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
 568                         if (len == 0)
 569                                 len = -EFAULT;
 570                         break;
 571                 }
 572
 573                 total -= this;
 574                 len += this;
 575                 to_copy += this;
 576                 if (total == 0)
 577                         break;
 578         }
 579         kfree(priv->buf);
 580         kfree(priv);
 581         return len;
 582 }
 583
 584 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 585 {
 586         struct kiocb            *iocb = req->context;
 587         struct kiocb_priv       *priv = iocb->private;
 588         struct ep_data          *epdata = priv->epdata;
 589
 590         /* lock against disconnect (and ideally, cancel) */
 591         spin_lock(&epdata->dev->lock);
 592         priv->req = NULL;
 593         priv->epdata = NULL;
 594
 595         /* if this was a write or a read returning no data then we
 596          * don't need to copy anything to userspace, so we can
 597          * complete the aio request immediately.
 598          */
 599         if (priv->iv == NULL || unlikely(req->actual == 0)) {
 600                 kfree(req->buf);
 601                 kfree(priv);
 602                 iocb->private = NULL;
 603                 /* aio_complete() reports bytes-transferred _and_ faults */
 604                 aio_complete(iocb, req->actual ? req->actual : req->status,
 605                                 req->status);
 606         } else {
 607                 /* retry() won't report both; so we hide some faults */
 608                 if (unlikely(0 != req->status))
 609                         DBG(epdata->dev, "%s fault %d len %d\n",
 610                                 ep->name, req->status, req->actual);
 611
 612                 priv->buf = req->buf;
 613                 priv->actual = req->actual;
 614                 kick_iocb(iocb);
 615         }
 616         spin_unlock(&epdata->dev->lock);
 617
 618         usb_ep_free_request(ep, req);
 619         put_ep(epdata);
 620 }
 621
 622 static ssize_t
 623 ep_aio_rwtail(
 624         struct kiocb    *iocb,
 625         char            *buf,
 626         size_t          len,
 627         struct ep_data  *epdata,
 628         const struct iovec *iv,
 629         unsigned long   nr_segs
 630 )
 631 {
 632         struct kiocb_priv       *priv;
 633         struct usb_request      *req;
 634         ssize_t                 value;
 635
 636         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 637         if (!priv) {
 638                 value = -ENOMEM;
 639 fail:
 640                 kfree(buf);
 641                 return value;
 642         }
 643         iocb->private = priv;
 644         priv->iv = iv;
 645         priv->nr_segs = nr_segs;
 646
 647         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 648         if (unlikely(value < 0)) {
 649                 kfree(priv);
 650                 goto fail;
 651         }
 652
 653         iocb->ki_cancel = ep_aio_cancel;
 654         get_ep(epdata);
 655         priv->epdata = epdata;
 656         priv->actual = 0;
 657
 658         /* each kiocb is coupled to one usb_request, but we can't
 659          * allocate or submit those if the host disconnected.
 660          */
 661         spin_lock_irq(&epdata->dev->lock);
 662         if (likely(epdata->ep)) {
 663                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 664                 if (likely(req)) {
 665                         priv->req = req;
 666                         req->buf = buf;
 667                         req->length = len;
 668                         req->complete = ep_aio_complete;
 669                         req->context = iocb;
 670                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 671                         if (unlikely(0 != value))
 672                                 usb_ep_free_request(epdata->ep, req);
 673                 } else
 674                         value = -EAGAIN;
 675         } else
 676                 value = -ENODEV;
 677         spin_unlock_irq(&epdata->dev->lock);
 678
 679         up(&epdata->lock);
 680
 681         if (unlikely(value)) {
 682                 kfree(priv);
 683                 put_ep(epdata);
 684         } else
 685                 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
 686         return value;
 687 }
 688
 689 static ssize_t
 690 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
 691                 unsigned long nr_segs, loff_t o)
 692 {
 693         struct ep_data          *epdata = iocb->ki_filp->private_data;
 694         char                    *buf;
 695
 696         if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN))
 697                 return -EINVAL;
 698
 699         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 700         if (unlikely(!buf))
 701                 return -ENOMEM;
 702
 703         iocb->ki_retry = ep_aio_read_retry;
 704         return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
 705 }
 706
 707 static ssize_t
 708 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
 709                 unsigned long nr_segs, loff_t o)
 710 {
 711         struct ep_data          *epdata = iocb->ki_filp->private_data;
 712         char                    *buf;
 713         size_t                  len = 0;
 714         int                     i = 0;
 715
 716         if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN)))
 717                 return -EINVAL;
 718
 719         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 720         if (unlikely(!buf))
 721                 return -ENOMEM;
 722
 723         for (i=0; i < nr_segs; i++) {
 724                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
 725                                 iov[i].iov_len) != 0)) {
 726                         kfree(buf);
 727                         return -EFAULT;
 728                 }
 729                 len += iov[i].iov_len;
 730         }
 731         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
 732 }
 733
 734 /*----------------------------------------------------------------------*/
 735
 736 /* used after endpoint configuration */
 737 static const struct file_operations ep_io_operations = {
 738         .owner =        THIS_MODULE,
 739         .llseek =       no_llseek,
 740
 741         .read =         ep_read,
 742         .write =        ep_write,
 743         .ioctl =        ep_ioctl,
 744         .release =      ep_release,
 745
 746         .aio_read =     ep_aio_read,
 747         .aio_write =    ep_aio_write,
 748 };
 749
 750 /* ENDPOINT INITIALIZATION
 751  *
 752  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 753  *     status = write (fd, descriptors, sizeof descriptors)
 754  *
 755  * That write establishes the endpoint configuration, configuring
 756  * the controller to process bulk, interrupt, or isochronous transfers
 757  * at the right maxpacket size, and so on.
 758  *
 759  * The descriptors are message type 1, identified by a host order u32
 760  * at the beginning of what's written.  Descriptor order is: full/low
 761  * speed descriptor, then optional high speed descriptor.
 762  */
 763 static ssize_t
 764 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 765 {
 766         struct ep_data          *data = fd->private_data;
 767         struct usb_ep           *ep;
 768         u32                     tag;
 769         int                     value, length = len;
 770
 771         if ((value = down_interruptible (&data->lock)) < 0)
 772                 return value;
 773
 774         if (data->state != STATE_EP_READY) {
 775                 value = -EL2HLT;
 776                 goto fail;
 777         }
 778
 779         value = len;
 780         if (len < USB_DT_ENDPOINT_SIZE + 4)
 781                 goto fail0;
 782
 783         /* we might need to change message format someday */
 784         if (copy_from_user (&tag, buf, 4)) {
 785                 goto fail1;
 786         }
 787         if (tag != 1) {
 788                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 789                 goto fail0;
 790         }
 791         buf += 4;
 792         len -= 4;
 793
 794         /* NOTE:  audio endpoint extensions not accepted here;
 795          * just don't include the extra bytes.
 796          */
 797
 798         /* full/low speed descriptor, then high speed */
 799         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 800                 goto fail1;
 801         }
 802         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 803                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 804                 goto fail0;
 805         if (len != USB_DT_ENDPOINT_SIZE) {
 806                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 807                         goto fail0;
 808                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 809                                         USB_DT_ENDPOINT_SIZE)) {
 810                         goto fail1;
 811                 }
 812                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 813                                 || data->hs_desc.bDescriptorType
 814                                         != USB_DT_ENDPOINT) {
 815                         DBG(data->dev, "config %s, bad hs length or type\n",
 816                                         data->name);
 817                         goto fail0;
 818                 }
 819         }
 820
 821         spin_lock_irq (&data->dev->lock);
 822         if (data->dev->state == STATE_DEV_UNBOUND) {
 823                 value = -ENOENT;
 824                 goto gone;
 825         } else if ((ep = data->ep) == NULL) {
 826                 value = -ENODEV;
 827                 goto gone;
 828         }
 829         switch (data->dev->gadget->speed) {
 830         case USB_SPEED_LOW:
 831         case USB_SPEED_FULL:
 832                 value = usb_ep_enable (ep, &data->desc);
 833                 if (value == 0)
 834                         data->state = STATE_EP_ENABLED;
 835                 break;
 836 #ifdef  CONFIG_USB_GADGET_DUALSPEED
 837         case USB_SPEED_HIGH:
 838                 /* fails if caller didn't provide that descriptor... */
 839                 value = usb_ep_enable (ep, &data->hs_desc);
 840                 if (value == 0)
 841                         data->state = STATE_EP_ENABLED;
 842                 break;
 843 #endif
 844         default:
 845                 DBG(data->dev, "unconnected, %s init abandoned\n",
 846                                 data->name);
 847                 value = -EINVAL;
 848         }
 849         if (value == 0) {
 850                 fd->f_op = &ep_io_operations;
 851                 value = length;
 852         }
 853 gone:
 854         spin_unlock_irq (&data->dev->lock);
 855         if (value < 0) {
 856 fail:
 857                 data->desc.bDescriptorType = 0;
 858                 data->hs_desc.bDescriptorType = 0;
 859         }
 860         up (&data->lock);
 861         return value;
 862 fail0:
 863         value = -EINVAL;
 864         goto fail;
 865 fail1:
 866         value = -EFAULT;
 867         goto fail;
 868 }
 869
 870 static int
 871 ep_open (struct inode *inode, struct file *fd)
 872 {
 873         struct ep_data          *data = inode->i_private;
 874         int                     value = -EBUSY;
 875
 876         if (down_interruptible (&data->lock) != 0)
 877                 return -EINTR;
 878         spin_lock_irq (&data->dev->lock);
 879         if (data->dev->state == STATE_DEV_UNBOUND)
 880                 value = -ENOENT;
 881         else if (data->state == STATE_EP_DISABLED) {
 882                 value = 0;
 883                 data->state = STATE_EP_READY;
 884                 get_ep (data);
 885                 fd->private_data = data;
 886                 VDEBUG (data->dev, "%s ready\n", data->name);
 887         } else
 888                 DBG (data->dev, "%s state %d\n",
 889                         data->name, data->state);
 890         spin_unlock_irq (&data->dev->lock);
 891         up (&data->lock);
 892         return value;
 893 }
 894
 895 /* used before endpoint configuration */
 896 static const struct file_operations ep_config_operations = {
 897         .owner =        THIS_MODULE,
 898         .llseek =       no_llseek,
 899
 900         .open =         ep_open,
 901         .write =        ep_config,
 902         .release =      ep_release,
 903 };
 904
 905 /*----------------------------------------------------------------------*/
 906
 907 /* EP0 IMPLEMENTATION can be partly in userspace.
 908  *
 909  * Drivers that use this facility receive various events, including
 910  * control requests the kernel doesn't handle.  Drivers that don't
 911  * use this facility may be too simple-minded for real applications.
 912  */
 913
 914 static inline void ep0_readable (struct dev_data *dev)
 915 {
 916         wake_up (&dev->wait);
 917         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 918 }
 919
 920 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 921 {
 922         struct dev_data         *dev = ep->driver_data;
 923
 924         if (req->buf != dev->rbuf) {
 925                 kfree(req->buf);
 926                 req->buf = dev->rbuf;
 927                 req->dma = DMA_ADDR_INVALID;
 928         }
 929         req->complete = epio_complete;
 930         dev->setup_out_ready = 0;
 931 }
 932
 933 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 934 {
 935         struct dev_data         *dev = ep->driver_data;
 936         unsigned long           flags;
 937         int                     free = 1;
 938
 939         /* for control OUT, data must still get to userspace */
 940         spin_lock_irqsave(&dev->lock, flags);
 941         if (!dev->setup_in) {
 942                 dev->setup_out_error = (req->status != 0);
 943                 if (!dev->setup_out_error)
 944                         free = 0;
 945                 dev->setup_out_ready = 1;
 946                 ep0_readable (dev);
 947         }
 948
 949         /* clean up as appropriate */
 950         if (free && req->buf != &dev->rbuf)
 951                 clean_req (ep, req);
 952         req->complete = epio_complete;
 953         spin_unlock_irqrestore(&dev->lock, flags);
 954 }
 955
 956 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 957 {
 958         struct dev_data *dev = ep->driver_data;
 959
 960         if (dev->setup_out_ready) {
 961                 DBG (dev, "ep0 request busy!\n");
 962                 return -EBUSY;
 963         }
 964         if (len > sizeof (dev->rbuf))
 965                 req->buf = kmalloc(len, GFP_ATOMIC);
 966         if (req->buf == NULL) {
 967                 req->buf = dev->rbuf;
 968                 return -ENOMEM;
 969         }
 970         req->complete = ep0_complete;
 971         req->length = len;
 972         req->zero = 0;
 973         return 0;
 974 }
 975
 976 static ssize_t
 977 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 978 {
 979         struct dev_data                 *dev = fd->private_data;
 980         ssize_t                         retval;
 981         enum ep0_state                  state;
 982
 983         spin_lock_irq (&dev->lock);
 984
 985         /* report fd mode change before acting on it */
 986         if (dev->setup_abort) {
 987                 dev->setup_abort = 0;
 988                 retval = -EIDRM;
 989                 goto done;
 990         }
 991
 992         /* control DATA stage */
 993         if ((state = dev->state) == STATE_DEV_SETUP) {
 994
 995                 if (dev->setup_in) {            /* stall IN */
 996                         VDEBUG(dev, "ep0in stall\n");
 997                         (void) usb_ep_set_halt (dev->gadget->ep0);
 998                         retval = -EL2HLT;
 999                         dev->state = STATE_DEV_CONNECTED;
1000
1001                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
1002                         struct usb_ep           *ep = dev->gadget->ep0;
1003                         struct usb_request      *req = dev->req;
1004
1005                         if ((retval = setup_req (ep, req, 0)) == 0)
1006                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1007                         dev->state = STATE_DEV_CONNECTED;
1008
1009                         /* assume that was SET_CONFIGURATION */
1010                         if (dev->current_config) {
1011                                 unsigned power;
1012
1013                                 if (gadget_is_dualspeed(dev->gadget)
1014                                                 && (dev->gadget->speed
1015                                                         == USB_SPEED_HIGH))
1016                                         power = dev->hs_config->bMaxPower;
1017                                 else
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", __func__, 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", __func__);
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", __func__, 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", __func__, 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         int             hs = 0;
1359
1360         /* only one configuration */
1361         if (index > 0)
1362                 return -EINVAL;
1363
1364         if (gadget_is_dualspeed(dev->gadget)) {
1365                 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1366                 if (type == USB_DT_OTHER_SPEED_CONFIG)
1367                         hs = !hs;
1368         }
1369         if (hs) {
1370                 dev->req->buf = dev->hs_config;
1371                 len = le16_to_cpu(dev->hs_config->wTotalLength);
1372         } else {
1373                 dev->req->buf = dev->config;
1374                 len = le16_to_cpu(dev->config->wTotalLength);
1375         }
1376         ((u8 *)dev->req->buf) [1] = type;
1377         return len;
1378 }
1379
1380 static int
1381 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1382 {
1383         struct dev_data                 *dev = get_gadget_data (gadget);
1384         struct usb_request              *req = dev->req;
1385         int                             value = -EOPNOTSUPP;
1386         struct usb_gadgetfs_event       *event;
1387         u16                             w_value = le16_to_cpu(ctrl->wValue);
1388         u16                             w_length = le16_to_cpu(ctrl->wLength);
1389
1390         spin_lock (&dev->lock);
1391         dev->setup_abort = 0;
1392         if (dev->state == STATE_DEV_UNCONNECTED) {
1393                 if (gadget_is_dualspeed(gadget)
1394                                 && gadget->speed == USB_SPEED_HIGH
1395                                 && dev->hs_config == NULL) {
1396                         spin_unlock(&dev->lock);
1397                         ERROR (dev, "no high speed config??\n");
1398                         return -EINVAL;
1399                 }
1400
1401                 dev->state = STATE_DEV_CONNECTED;
1402                 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1403
1404                 INFO (dev, "connected\n");
1405                 event = next_event (dev, GADGETFS_CONNECT);
1406                 event->u.speed = gadget->speed;
1407                 ep0_readable (dev);
1408
1409         /* host may have given up waiting for response.  we can miss control
1410          * requests handled lower down (device/endpoint status and features);
1411          * then ep0_{read,write} will report the wrong status. controller
1412          * driver will have aborted pending i/o.
1413          */
1414         } else if (dev->state == STATE_DEV_SETUP)
1415                 dev->setup_abort = 1;
1416
1417         req->buf = dev->rbuf;
1418         req->dma = DMA_ADDR_INVALID;
1419         req->context = NULL;
1420         value = -EOPNOTSUPP;
1421         switch (ctrl->bRequest) {
1422
1423         case USB_REQ_GET_DESCRIPTOR:
1424                 if (ctrl->bRequestType != USB_DIR_IN)
1425                         goto unrecognized;
1426                 switch (w_value >> 8) {
1427
1428                 case USB_DT_DEVICE:
1429                         value = min (w_length, (u16) sizeof *dev->dev);
1430                         req->buf = dev->dev;
1431                         break;
1432 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1433                 case USB_DT_DEVICE_QUALIFIER:
1434                         if (!dev->hs_config)
1435                                 break;
1436                         value = min (w_length, (u16)
1437                                 sizeof (struct usb_qualifier_descriptor));
1438                         make_qualifier (dev);
1439                         break;
1440                 case USB_DT_OTHER_SPEED_CONFIG:
1441                         // FALLTHROUGH
1442 #endif
1443                 case USB_DT_CONFIG:
1444                         value = config_buf (dev,
1445                                         w_value >> 8,
1446                                         w_value & 0xff);
1447                         if (value >= 0)
1448                                 value = min (w_length, (u16) value);
1449                         break;
1450                 case USB_DT_STRING:
1451                         goto unrecognized;
1452
1453                 default:                // all others are errors
1454                         break;
1455                 }
1456                 break;
1457
1458         /* currently one config, two speeds */
1459         case USB_REQ_SET_CONFIGURATION:
1460                 if (ctrl->bRequestType != 0)
1461                         goto unrecognized;
1462                 if (0 == (u8) w_value) {
1463                         value = 0;
1464                         dev->current_config = 0;
1465                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1466                         // user mode expected to disable endpoints
1467                 } else {
1468                         u8      config, power;
1469
1470                         if (gadget_is_dualspeed(gadget)
1471                                         && gadget->speed == USB_SPEED_HIGH) {
1472                                 config = dev->hs_config->bConfigurationValue;
1473                                 power = dev->hs_config->bMaxPower;
1474                         } else {
1475                                 config = dev->config->bConfigurationValue;
1476                                 power = dev->config->bMaxPower;
1477                         }
1478
1479                         if (config == (u8) w_value) {
1480                                 value = 0;
1481                                 dev->current_config = config;
1482                                 usb_gadget_vbus_draw(gadget, 2 * power);
1483                         }
1484                 }
1485
1486                 /* report SET_CONFIGURATION like any other control request,
1487                  * except that usermode may not stall this.  the next
1488                  * request mustn't be allowed start until this finishes:
1489                  * endpoints and threads set up, etc.
1490                  *
1491                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1492                  * has bad/racey automagic that prevents synchronizing here.
1493                  * even kernel mode drivers often miss them.
1494                  */
1495                 if (value == 0) {
1496                         INFO (dev, "configuration #%d\n", dev->current_config);
1497                         if (dev->usermode_setup) {
1498                                 dev->setup_can_stall = 0;
1499                                 goto delegate;
1500                         }
1501                 }
1502                 break;
1503
1504 #ifndef CONFIG_USB_GADGET_PXA2XX
1505         /* PXA automagically handles this request too */
1506         case USB_REQ_GET_CONFIGURATION:
1507                 if (ctrl->bRequestType != 0x80)
1508                         goto unrecognized;
1509                 *(u8 *)req->buf = dev->current_config;
1510                 value = min (w_length, (u16) 1);
1511                 break;
1512 #endif
1513
1514         default:
1515 unrecognized:
1516                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1517                         dev->usermode_setup ? "delegate" : "fail",
1518                         ctrl->bRequestType, ctrl->bRequest,
1519                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1520
1521                 /* if there's an ep0 reader, don't stall */
1522                 if (dev->usermode_setup) {
1523                         dev->setup_can_stall = 1;
1524 delegate:
1525                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1526                                                 ? 1 : 0;
1527                         dev->setup_wLength = w_length;
1528                         dev->setup_out_ready = 0;
1529                         dev->setup_out_error = 0;
1530                         value = 0;
1531
1532                         /* read DATA stage for OUT right away */
1533                         if (unlikely (!dev->setup_in && w_length)) {
1534                                 value = setup_req (gadget->ep0, dev->req,
1535                                                         w_length);
1536                                 if (value < 0)
1537                                         break;
1538                                 value = usb_ep_queue (gadget->ep0, dev->req,
1539                                                         GFP_ATOMIC);
1540                                 if (value < 0) {
1541                                         clean_req (gadget->ep0, dev->req);
1542                                         break;
1543                                 }
1544
1545                                 /* we can't currently stall these */
1546                                 dev->setup_can_stall = 0;
1547                         }
1548
1549                         /* state changes when reader collects event */
1550                         event = next_event (dev, GADGETFS_SETUP);
1551                         event->u.setup = *ctrl;
1552                         ep0_readable (dev);
1553                         spin_unlock (&dev->lock);
1554                         return 0;
1555                 }
1556         }
1557
1558         /* proceed with data transfer and status phases? */
1559         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1560                 req->length = value;
1561                 req->zero = value < w_length;
1562                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1563                 if (value < 0) {
1564                         DBG (dev, "ep_queue --> %d\n", value);
1565                         req->status = 0;
1566                 }
1567         }
1568
1569         /* device stalls when value < 0 */
1570         spin_unlock (&dev->lock);
1571         return value;
1572 }
1573
1574 static void destroy_ep_files (struct dev_data *dev)
1575 {
1576         struct list_head        *entry, *tmp;
1577
1578         DBG (dev, "%s %d\n", __func__, dev->state);
1579
1580         /* dev->state must prevent interference */
1581 restart:
1582         spin_lock_irq (&dev->lock);
1583         list_for_each_safe (entry, tmp, &dev->epfiles) {
1584                 struct ep_data  *ep;
1585                 struct inode    *parent;
1586                 struct dentry   *dentry;
1587
1588                 /* break link to FS */
1589                 ep = list_entry (entry, struct ep_data, epfiles);
1590                 list_del_init (&ep->epfiles);
1591                 dentry = ep->dentry;
1592                 ep->dentry = NULL;
1593                 parent = dentry->d_parent->d_inode;
1594
1595                 /* break link to controller */
1596                 if (ep->state == STATE_EP_ENABLED)
1597                         (void) usb_ep_disable (ep->ep);
1598                 ep->state = STATE_EP_UNBOUND;
1599                 usb_ep_free_request (ep->ep, ep->req);
1600                 ep->ep = NULL;
1601                 wake_up (&ep->wait);
1602                 put_ep (ep);
1603
1604                 spin_unlock_irq (&dev->lock);
1605
1606                 /* break link to dcache */
1607                 mutex_lock (&parent->i_mutex);
1608                 d_delete (dentry);
1609                 dput (dentry);
1610                 mutex_unlock (&parent->i_mutex);
1611
1612                 /* fds may still be open */
1613                 goto restart;
1614         }
1615         spin_unlock_irq (&dev->lock);
1616 }
1617
1618
1619 static struct inode *
1620 gadgetfs_create_file (struct super_block *sb, char const *name,
1621                 void *data, const struct file_operations *fops,
1622                 struct dentry **dentry_p);
1623
1624 static int activate_ep_files (struct dev_data *dev)
1625 {
1626         struct usb_ep   *ep;
1627         struct ep_data  *data;
1628
1629         gadget_for_each_ep (ep, dev->gadget) {
1630
1631                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1632                 if (!data)
1633                         goto enomem0;
1634                 data->state = STATE_EP_DISABLED;
1635                 init_MUTEX (&data->lock);
1636                 init_waitqueue_head (&data->wait);
1637
1638                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1639                 atomic_set (&data->count, 1);
1640                 data->dev = dev;
1641                 get_dev (dev);
1642
1643                 data->ep = ep;
1644                 ep->driver_data = data;
1645
1646                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1647                 if (!data->req)
1648                         goto enomem1;
1649
1650                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1651                                 data, &ep_config_operations,
1652                                 &data->dentry);
1653                 if (!data->inode)
1654                         goto enomem2;
1655                 list_add_tail (&data->epfiles, &dev->epfiles);
1656         }
1657         return 0;
1658
1659 enomem2:
1660         usb_ep_free_request (ep, data->req);
1661 enomem1:
1662         put_dev (dev);
1663         kfree (data);
1664 enomem0:
1665         DBG (dev, "%s enomem\n", __func__);
1666         destroy_ep_files (dev);
1667         return -ENOMEM;
1668 }
1669
1670 static void
1671 gadgetfs_unbind (struct usb_gadget *gadget)
1672 {
1673         struct dev_data         *dev = get_gadget_data (gadget);
1674
1675         DBG (dev, "%s\n", __func__);
1676
1677         spin_lock_irq (&dev->lock);
1678         dev->state = STATE_DEV_UNBOUND;
1679         spin_unlock_irq (&dev->lock);
1680
1681         destroy_ep_files (dev);
1682         gadget->ep0->driver_data = NULL;
1683         set_gadget_data (gadget, NULL);
1684
1685         /* we've already been disconnected ... no i/o is active */
1686         if (dev->req)
1687                 usb_ep_free_request (gadget->ep0, dev->req);
1688         DBG (dev, "%s done\n", __func__);
1689         put_dev (dev);
1690 }
1691
1692 static struct dev_data          *the_device;
1693
1694 static int
1695 gadgetfs_bind (struct usb_gadget *gadget)
1696 {
1697         struct dev_data         *dev = the_device;
1698
1699         if (!dev)
1700                 return -ESRCH;
1701         if (0 != strcmp (CHIP, gadget->name)) {
1702                 pr_err("%s expected %s controller not %s\n",
1703                         shortname, CHIP, gadget->name);
1704                 return -ENODEV;
1705         }
1706
1707         set_gadget_data (gadget, dev);
1708         dev->gadget = gadget;
1709         gadget->ep0->driver_data = dev;
1710         dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1711
1712         /* preallocate control response and buffer */
1713         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1714         if (!dev->req)
1715                 goto enomem;
1716         dev->req->context = NULL;
1717         dev->req->complete = epio_complete;
1718
1719         if (activate_ep_files (dev) < 0)
1720                 goto enomem;
1721
1722         INFO (dev, "bound to %s driver\n", gadget->name);
1723         spin_lock_irq(&dev->lock);
1724         dev->state = STATE_DEV_UNCONNECTED;
1725         spin_unlock_irq(&dev->lock);
1726         get_dev (dev);
1727         return 0;
1728
1729 enomem:
1730         gadgetfs_unbind (gadget);
1731         return -ENOMEM;
1732 }
1733
1734 static void
1735 gadgetfs_disconnect (struct usb_gadget *gadget)
1736 {
1737         struct dev_data         *dev = get_gadget_data (gadget);
1738
1739         spin_lock (&dev->lock);
1740         if (dev->state == STATE_DEV_UNCONNECTED)
1741                 goto exit;
1742         dev->state = STATE_DEV_UNCONNECTED;
1743
1744         INFO (dev, "disconnected\n");
1745         next_event (dev, GADGETFS_DISCONNECT);
1746         ep0_readable (dev);
1747 exit:
1748         spin_unlock (&dev->lock);
1749 }
1750
1751 static void
1752 gadgetfs_suspend (struct usb_gadget *gadget)
1753 {
1754         struct dev_data         *dev = get_gadget_data (gadget);
1755
1756         INFO (dev, "suspended from state %d\n", dev->state);
1757         spin_lock (&dev->lock);
1758         switch (dev->state) {
1759         case STATE_DEV_SETUP:           // VERY odd... host died??
1760         case STATE_DEV_CONNECTED:
1761         case STATE_DEV_UNCONNECTED:
1762                 next_event (dev, GADGETFS_SUSPEND);
1763                 ep0_readable (dev);
1764                 /* FALLTHROUGH */
1765         default:
1766                 break;
1767         }
1768         spin_unlock (&dev->lock);
1769 }
1770
1771 static struct usb_gadget_driver gadgetfs_driver = {
1772 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1773         .speed          = USB_SPEED_HIGH,
1774 #else
1775         .speed          = USB_SPEED_FULL,
1776 #endif
1777         .function       = (char *) driver_desc,
1778         .bind           = gadgetfs_bind,
1779         .unbind         = gadgetfs_unbind,
1780         .setup          = gadgetfs_setup,
1781         .disconnect     = gadgetfs_disconnect,
1782         .suspend        = gadgetfs_suspend,
1783
1784         .driver = {
1785                 .name           = (char *) shortname,
1786         },
1787 };
1788
1789 /*----------------------------------------------------------------------*/
1790
1791 static void gadgetfs_nop(struct usb_gadget *arg) { }
1792
1793 static int gadgetfs_probe (struct usb_gadget *gadget)
1794 {
1795         CHIP = gadget->name;
1796         return -EISNAM;
1797 }
1798
1799 static struct usb_gadget_driver probe_driver = {
1800         .speed          = USB_SPEED_HIGH,
1801         .bind           = gadgetfs_probe,
1802         .unbind         = gadgetfs_nop,
1803         .setup          = (void *)gadgetfs_nop,
1804         .disconnect     = gadgetfs_nop,
1805         .driver = {
1806                 .name           = "nop",
1807         },
1808 };
1809
1810
1811 /* DEVICE INITIALIZATION
1812  *
1813  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1814  *     status = write (fd, descriptors, sizeof descriptors)
1815  *
1816  * That write establishes the device configuration, so the kernel can
1817  * bind to the controller ... guaranteeing it can handle enumeration
1818  * at all necessary speeds.  Descriptor order is:
1819  *
1820  * . message tag (u32, host order) ... for now, must be zero; it
1821  *      would change to support features like multi-config devices
1822  * . full/low speed config ... all wTotalLength bytes (with interface,
1823  *      class, altsetting, endpoint, and other descriptors)
1824  * . high speed config ... all descriptors, for high speed operation;
1825  *      this one's optional except for high-speed hardware
1826  * . device descriptor
1827  *
1828  * Endpoints are not yet enabled. Drivers must wait until device
1829  * configuration and interface altsetting changes create
1830  * the need to configure (or unconfigure) them.
1831  *
1832  * After initialization, the device stays active for as long as that
1833  * $CHIP file is open.  Events must then be read from that descriptor,
1834  * such as configuration notifications.
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 (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1858                 return -EINVAL;
1859
1860         /* we might need to change message format someday */
1861         if (copy_from_user (&tag, buf, 4))
1862                 return -EFAULT;
1863         if (tag != 0)
1864                 return -EINVAL;
1865         buf += 4;
1866         length -= 4;
1867
1868         kbuf = kmalloc (length, GFP_KERNEL);
1869         if (!kbuf)
1870                 return -ENOMEM;
1871         if (copy_from_user (kbuf, buf, length)) {
1872                 kfree (kbuf);
1873                 return -EFAULT;
1874         }
1875
1876         spin_lock_irq (&dev->lock);
1877         value = -EINVAL;
1878         if (dev->buf)
1879                 goto fail;
1880         dev->buf = kbuf;
1881
1882         /* full or low speed config */
1883         dev->config = (void *) kbuf;
1884         total = le16_to_cpu(dev->config->wTotalLength);
1885         if (!is_valid_config (dev->config) || total >= length)
1886                 goto fail;
1887         kbuf += total;
1888         length -= total;
1889
1890         /* optional high speed config */
1891         if (kbuf [1] == USB_DT_CONFIG) {
1892                 dev->hs_config = (void *) kbuf;
1893                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1894                 if (!is_valid_config (dev->hs_config) || total >= length)
1895                         goto fail;
1896                 kbuf += total;
1897                 length -= total;
1898         }
1899
1900         /* could support multiple configs, using another encoding! */
1901
1902         /* device descriptor (tweaked for paranoia) */
1903         if (length != USB_DT_DEVICE_SIZE)
1904                 goto fail;
1905         dev->dev = (void *)kbuf;
1906         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1907                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1908                         || dev->dev->bNumConfigurations != 1)
1909                 goto fail;
1910         dev->dev->bNumConfigurations = 1;
1911         dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200);
1912
1913         /* triggers gadgetfs_bind(); then we can enumerate. */
1914         spin_unlock_irq (&dev->lock);
1915         value = usb_gadget_register_driver (&gadgetfs_driver);
1916         if (value != 0) {
1917                 kfree (dev->buf);
1918                 dev->buf = NULL;
1919         } else {
1920                 /* at this point "good" hardware has for the first time
1921                  * let the USB the host see us.  alternatively, if users
1922                  * unplug/replug that will clear all the error state.
1923                  *
1924                  * note:  everything running before here was guaranteed
1925                  * to choke driver model style diagnostics.  from here
1926                  * on, they can work ... except in cleanup paths that
1927                  * kick in after the ep0 descriptor is closed.
1928                  */
1929                 fd->f_op = &ep0_io_operations;
1930                 value = len;
1931         }
1932         return value;
1933
1934 fail:
1935         spin_unlock_irq (&dev->lock);
1936         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1937         kfree (dev->buf);
1938         dev->buf = NULL;
1939         return value;
1940 }
1941
1942 static int
1943 dev_open (struct inode *inode, struct file *fd)
1944 {
1945         struct dev_data         *dev = inode->i_private;
1946         int                     value = -EBUSY;
1947
1948         spin_lock_irq(&dev->lock);
1949         if (dev->state == STATE_DEV_DISABLED) {
1950                 dev->ev_next = 0;
1951                 dev->state = STATE_DEV_OPENED;
1952                 fd->private_data = dev;
1953                 get_dev (dev);
1954                 value = 0;
1955         }
1956         spin_unlock_irq(&dev->lock);
1957         return value;
1958 }
1959
1960 static const struct file_operations dev_init_operations = {
1961         .owner =        THIS_MODULE,
1962         .llseek =       no_llseek,
1963
1964         .open =         dev_open,
1965         .write =        dev_config,
1966         .fasync =       ep0_fasync,
1967         .ioctl =        dev_ioctl,
1968         .release =      dev_release,
1969 };
1970
1971 /*----------------------------------------------------------------------*/
1972
1973 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1974  *
1975  * Mounting the filesystem creates a controller file, used first for
1976  * device configuration then later for event monitoring.
1977  */
1978
1979
1980 /* FIXME PAM etc could set this security policy without mount options
1981  * if epfiles inherited ownership and permissons from ep0 ...
1982  */
1983
1984 static unsigned default_uid;
1985 static unsigned default_gid;
1986 static unsigned default_perm = S_IRUSR | S_IWUSR;
1987
1988 module_param (default_uid, uint, 0644);
1989 module_param (default_gid, uint, 0644);
1990 module_param (default_perm, uint, 0644);
1991
1992
1993 static struct inode *
1994 gadgetfs_make_inode (struct super_block *sb,
1995                 void *data, const struct file_operations *fops,
1996                 int mode)
1997 {
1998         struct inode *inode = new_inode (sb);
1999
2000         if (inode) {
2001                 inode->i_mode = mode;
2002                 inode->i_uid = default_uid;
2003                 inode->i_gid = default_gid;
2004                 inode->i_blocks = 0;
2005                 inode->i_atime = inode->i_mtime = inode->i_ctime
2006                                 = CURRENT_TIME;
2007                 inode->i_private = data;
2008                 inode->i_fop = fops;
2009         }
2010         return inode;
2011 }
2012
2013 /* creates in fs root directory, so non-renamable and non-linkable.
2014  * so inode and dentry are paired, until device reconfig.
2015  */
2016 static struct inode *
2017 gadgetfs_create_file (struct super_block *sb, char const *name,
2018                 void *data, const struct file_operations *fops,
2019                 struct dentry **dentry_p)
2020 {
2021         struct dentry   *dentry;
2022         struct inode    *inode;
2023
2024         dentry = d_alloc_name(sb->s_root, name);
2025         if (!dentry)
2026                 return NULL;
2027
2028         inode = gadgetfs_make_inode (sb, data, fops,
2029                         S_IFREG | (default_perm & S_IRWXUGO));
2030         if (!inode) {
2031                 dput(dentry);
2032                 return NULL;
2033         }
2034         d_add (dentry, inode);
2035         *dentry_p = dentry;
2036         return inode;
2037 }
2038
2039 static struct super_operations gadget_fs_operations = {
2040         .statfs =       simple_statfs,
2041         .drop_inode =   generic_delete_inode,
2042 };
2043
2044 static int
2045 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2046 {
2047         struct inode    *inode;
2048         struct dentry   *d;
2049         struct dev_data *dev;
2050
2051         if (the_device)
2052                 return -ESRCH;
2053
2054         /* fake probe to determine $CHIP */
2055         (void) usb_gadget_register_driver (&probe_driver);
2056         if (!CHIP)
2057                 return -ENODEV;
2058
2059         /* superblock */
2060         sb->s_blocksize = PAGE_CACHE_SIZE;
2061         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2062         sb->s_magic = GADGETFS_MAGIC;
2063         sb->s_op = &gadget_fs_operations;
2064         sb->s_time_gran = 1;
2065
2066         /* root inode */
2067         inode = gadgetfs_make_inode (sb,
2068                         NULL, &simple_dir_operations,
2069                         S_IFDIR | S_IRUGO | S_IXUGO);
2070         if (!inode)
2071                 goto enomem0;
2072         inode->i_op = &simple_dir_inode_operations;
2073         if (!(d = d_alloc_root (inode)))
2074                 goto enomem1;
2075         sb->s_root = d;
2076
2077         /* the ep0 file is named after the controller we expect;
2078          * user mode code can use it for sanity checks, like we do.
2079          */
2080         dev = dev_new ();
2081         if (!dev)
2082                 goto enomem2;
2083
2084         dev->sb = sb;
2085         if (!gadgetfs_create_file (sb, CHIP,
2086                                 dev, &dev_init_operations,
2087                                 &dev->dentry))
2088                 goto enomem3;
2089
2090         /* other endpoint files are available after hardware setup,
2091          * from binding to a controller.
2092          */
2093         the_device = dev;
2094         return 0;
2095
2096 enomem3:
2097         put_dev (dev);
2098 enomem2:
2099         dput (d);
2100 enomem1:
2101         iput (inode);
2102 enomem0:
2103         return -ENOMEM;
2104 }
2105
2106 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2107 static int
2108 gadgetfs_get_sb (struct file_system_type *t, int flags,
2109                 const char *path, void *opts, struct vfsmount *mnt)
2110 {
2111         return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt);
2112 }
2113
2114 static void
2115 gadgetfs_kill_sb (struct super_block *sb)
2116 {
2117         kill_litter_super (sb);
2118         if (the_device) {
2119                 put_dev (the_device);
2120                 the_device = NULL;
2121         }
2122 }
2123
2124 /*----------------------------------------------------------------------*/
2125
2126 static struct file_system_type gadgetfs_type = {
2127         .owner          = THIS_MODULE,
2128         .name           = shortname,
2129         .get_sb         = gadgetfs_get_sb,
2130         .kill_sb        = gadgetfs_kill_sb,
2131 };
2132
2133 /*----------------------------------------------------------------------*/
2134
2135 static int __init init (void)
2136 {
2137         int status;
2138
2139         status = register_filesystem (&gadgetfs_type);
2140         if (status == 0)
2141                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2142                         shortname, driver_desc);
2143         return status;
2144 }
2145 module_init (init);
2146
2147 static void __exit cleanup (void)
2148 {
2149         pr_debug ("unregister %s\n", shortname);
2150         unregister_filesystem (&gadgetfs_type);
2151 }
2152 module_exit (cleanup);
2153