drivers/usb/gadget/inode.c

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