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