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      DEBUG                   /* data to help fault diagnosis */
  24 // #define      VERBOSE         /* extra debug messages (success too) */
  25
  26 #include <linux/init.h>
  27 #include <linux/module.h>
  28 #include <linux/fs.h>
  29 #include <linux/pagemap.h>
  30 #include <linux/uts.h>
  31 #include <linux/wait.h>
  32 #include <linux/compiler.h>
  33 #include <asm/uaccess.h>
  34 #include <linux/slab.h>
  35 #include <linux/poll.h>
  36
  37 #include <linux/device.h>
  38 #include <linux/moduleparam.h>
  39
  40 #include <linux/usb_gadgetfs.h>
  41 #include <linux/usb_gadget.h>
  42
  43
  44 /*
  45  * The gadgetfs API maps each endpoint to a file descriptor so that you
  46  * can use standard synchronous read/write calls for I/O.  There's some
  47  * O_NONBLOCK and O_ASYNC/FASYNC style i/o support.  Example usermode
  48  * drivers show how this works in practice.  You can also use AIO to
  49  * eliminate I/O gaps between requests, to help when streaming data.
  50  *
  51  * Key parts that must be USB-specific are protocols defining how the
  52  * read/write operations relate to the hardware state machines.  There
  53  * are two types of files.  One type is for the device, implementing ep0.
  54  * The other type is for each IN or OUT endpoint.  In both cases, the
  55  * user mode driver must configure the hardware before using it.
  56  *
  57  * - First, dev_config() is called when /dev/gadget/$CHIP is configured
  58  *   (by writing configuration and device descriptors).  Afterwards it
  59  *   may serve as a source of device events, used to handle all control
  60  *   requests other than basic enumeration.
  61  *
  62  * - Then either immediately, or after a SET_CONFIGURATION control request,
  63  *   ep_config() is called when each /dev/gadget/ep* file is configured
  64  *   (by writing endpoint descriptors).  Afterwards these files are used
  65  *   to write() IN data or to read() OUT data.  To halt the endpoint, a
  66  *   "wrong direction" request is issued (like reading an IN endpoint).
  67  *
  68  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
  69  * not possible on all hardware.  For example, precise fault handling with
  70  * respect to data left in endpoint fifos after aborted operations; or
  71  * selective clearing of endpoint halts, to implement SET_INTERFACE.
  72  */
  73
  74 #define DRIVER_DESC     "USB Gadget filesystem"
  75 #define DRIVER_VERSION  "24 Aug 2004"
  76
  77 static const char driver_desc [] = DRIVER_DESC;
  78 static const char shortname [] = "gadgetfs";
  79
  80 MODULE_DESCRIPTION (DRIVER_DESC);
  81 MODULE_AUTHOR ("David Brownell");
  82 MODULE_LICENSE ("GPL");
  83
  84
  85 /*----------------------------------------------------------------------*/
  86
  87 #define GADGETFS_MAGIC          0xaee71ee7
  88 #define DMA_ADDR_INVALID        (~(dma_addr_t)0)
  89
  90 /* /dev/gadget/$CHIP represents ep0 and the whole device */
  91 enum ep0_state {
  92         /* DISBLED is the initial state.
  93          */
  94         STATE_DEV_DISABLED = 0,
  95
  96         /* Only one open() of /dev/gadget/$CHIP; only one file tracks
  97          * ep0/device i/o modes and binding to the controller.  Driver
  98          * must always write descriptors to initialize the device, then
  99          * the device becomes UNCONNECTED until enumeration.
 100          */
 101         STATE_OPENED,
 102
 103         /* From then on, ep0 fd is in either of two basic modes:
 104          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
 105          * - SETUP: read/write will transfer control data and succeed;
 106          *   or if "wrong direction", performs protocol stall
 107          */
 108         STATE_UNCONNECTED,
 109         STATE_CONNECTED,
 110         STATE_SETUP,
 111
 112         /* UNBOUND means the driver closed ep0, so the device won't be
 113          * accessible again (DEV_DISABLED) until all fds are closed.
 114          */
 115         STATE_DEV_UNBOUND,
 116 };
 117
 118 /* enough for the whole queue: most events invalidate others */
 119 #define N_EVENT                 5
 120
 121 struct dev_data {
 122         spinlock_t                      lock;
 123         atomic_t                        count;
 124         enum ep0_state                  state;
 125         struct usb_gadgetfs_event       event [N_EVENT];
 126         unsigned                        ev_next;
 127         struct fasync_struct            *fasync;
 128         u8                              current_config;
 129
 130         /* drivers reading ep0 MUST handle control requests (SETUP)
 131          * reported that way; else the host will time out.
 132          */
 133         unsigned                        usermode_setup : 1,
 134                                         setup_in : 1,
 135                                         setup_can_stall : 1,
 136                                         setup_out_ready : 1,
 137                                         setup_out_error : 1,
 138                                         setup_abort : 1;
 139         unsigned                        setup_wLength;
 140
 141         /* the rest is basically write-once */
 142         struct usb_config_descriptor    *config, *hs_config;
 143         struct usb_device_descriptor    *dev;
 144         struct usb_request              *req;
 145         struct usb_gadget               *gadget;
 146         struct list_head                epfiles;
 147         void                            *buf;
 148         wait_queue_head_t               wait;
 149         struct super_block              *sb;
 150         struct dentry                   *dentry;
 151
 152         /* except this scratch i/o buffer for ep0 */
 153         u8                              rbuf [256];
 154 };
 155
 156 static inline void get_dev (struct dev_data *data)
 157 {
 158         atomic_inc (&data->count);
 159 }
 160
 161 static void put_dev (struct dev_data *data)
 162 {
 163         if (likely (!atomic_dec_and_test (&data->count)))
 164                 return;
 165         /* needs no more cleanup */
 166         BUG_ON (waitqueue_active (&data->wait));
 167         kfree (data);
 168 }
 169
 170 static struct dev_data *dev_new (void)
 171 {
 172         struct dev_data         *dev;
 173
 174         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 175         if (!dev)
 176                 return NULL;
 177         dev->state = STATE_DEV_DISABLED;
 178         atomic_set (&dev->count, 1);
 179         spin_lock_init (&dev->lock);
 180         INIT_LIST_HEAD (&dev->epfiles);
 181         init_waitqueue_head (&dev->wait);
 182         return dev;
 183 }
 184
 185 /*----------------------------------------------------------------------*/
 186
 187 /* other /dev/gadget/$ENDPOINT files represent endpoints */
 188 enum ep_state {
 189         STATE_EP_DISABLED = 0,
 190         STATE_EP_READY,
 191         STATE_EP_DEFER_ENABLE,
 192         STATE_EP_ENABLED,
 193         STATE_EP_UNBOUND,
 194 };
 195
 196 struct ep_data {
 197         struct semaphore                lock;
 198         enum ep_state                   state;
 199         atomic_t                        count;
 200         struct dev_data                 *dev;
 201         /* must hold dev->lock before accessing ep or req */
 202         struct usb_ep                   *ep;
 203         struct usb_request              *req;
 204         ssize_t                         status;
 205         char                            name [16];
 206         struct usb_endpoint_descriptor  desc, hs_desc;
 207         struct list_head                epfiles;
 208         wait_queue_head_t               wait;
 209         struct dentry                   *dentry;
 210         struct inode                    *inode;
 211 };
 212
 213 static inline void get_ep (struct ep_data *data)
 214 {
 215         atomic_inc (&data->count);
 216 }
 217
 218 static void put_ep (struct ep_data *data)
 219 {
 220         if (likely (!atomic_dec_and_test (&data->count)))
 221                 return;
 222         put_dev (data->dev);
 223         /* needs no more cleanup */
 224         BUG_ON (!list_empty (&data->epfiles));
 225         BUG_ON (waitqueue_active (&data->wait));
 226         BUG_ON (down_trylock (&data->lock) != 0);
 227         kfree (data);
 228 }
 229
 230 /*----------------------------------------------------------------------*/
 231
 232 /* most "how to use the hardware" policy choices are in userspace:
 233  * mapping endpoint roles (which the driver needs) to the capabilities
 234  * which the usb controller has.  most of those capabilities are exposed
 235  * implicitly, starting with the driver name and then endpoint names.
 236  */
 237
 238 static const char *CHIP;
 239
 240 /*----------------------------------------------------------------------*/
 241
 242 /* NOTE:  don't use dev_printk calls before binding to the gadget
 243  * at the end of ep0 configuration, or after unbind.
 244  */
 245
 246 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
 247 #define xprintk(d,level,fmt,args...) \
 248         printk(level "%s: " fmt , shortname , ## args)
 249
 250 #ifdef DEBUG
 251 #define DBG(dev,fmt,args...) \
 252         xprintk(dev , KERN_DEBUG , fmt , ## args)
 253 #else
 254 #define DBG(dev,fmt,args...) \
 255         do { } while (0)
 256 #endif /* DEBUG */
 257
 258 #ifdef VERBOSE
 259 #define VDEBUG  DBG
 260 #else
 261 #define VDEBUG(dev,fmt,args...) \
 262         do { } while (0)
 263 #endif /* DEBUG */
 264
 265 #define ERROR(dev,fmt,args...) \
 266         xprintk(dev , KERN_ERR , fmt , ## args)
 267 #define WARN(dev,fmt,args...) \
 268         xprintk(dev , KERN_WARNING , fmt , ## args)
 269 #define INFO(dev,fmt,args...) \
 270         xprintk(dev , KERN_INFO , fmt , ## args)
 271
 272
 273 /*----------------------------------------------------------------------*/
 274
 275 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 276  *
 277  * After opening, configure non-control endpoints.  Then use normal
 278  * stream read() and write() requests; and maybe ioctl() to get more
 279  * precise FIFO status when recovering from cancellation.
 280  */
 281
 282 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 283 {
 284         struct ep_data  *epdata = ep->driver_data;
 285
 286         if (!req->context)
 287                 return;
 288         if (req->status)
 289                 epdata->status = req->status;
 290         else
 291                 epdata->status = req->actual;
 292         complete ((struct completion *)req->context);
 293 }
 294
 295 /* tasklock endpoint, returning when it's connected.
 296  * still need dev->lock to use epdata->ep.
 297  */
 298 static int
 299 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
 300 {
 301         int     val;
 302
 303         if (f_flags & O_NONBLOCK) {
 304                 if (down_trylock (&epdata->lock) != 0)
 305                         goto nonblock;
 306                 if (epdata->state != STATE_EP_ENABLED) {
 307                         up (&epdata->lock);
 308 nonblock:
 309                         val = -EAGAIN;
 310                 } else
 311                         val = 0;
 312                 return val;
 313         }
 314
 315         if ((val = down_interruptible (&epdata->lock)) < 0)
 316                 return val;
 317 newstate:
 318         switch (epdata->state) {
 319         case STATE_EP_ENABLED:
 320                 break;
 321         case STATE_EP_DEFER_ENABLE:
 322                 DBG (epdata->dev, "%s wait for host\n", epdata->name);
 323                 if ((val = wait_event_interruptible (epdata->wait,
 324                                 epdata->state != STATE_EP_DEFER_ENABLE
 325                                 || epdata->dev->state == STATE_DEV_UNBOUND
 326                                 )) < 0)
 327                         goto fail;
 328                 goto newstate;
 329         // case STATE_EP_DISABLED:              /* "can't happen" */
 330         // case STATE_EP_READY:                 /* "can't happen" */
 331         default:                                /* error! */
 332                 pr_debug ("%s: ep %p not available, state %d\n",
 333                                 shortname, epdata, epdata->state);
 334                 // FALLTHROUGH
 335         case STATE_EP_UNBOUND:                  /* clean disconnect */
 336                 val = -ENODEV;
 337 fail:
 338                 up (&epdata->lock);
 339         }
 340         return val;
 341 }
 342
 343 static ssize_t
 344 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 345 {
 346         DECLARE_COMPLETION (done);
 347         int value;
 348
 349         spin_lock_irq (&epdata->dev->lock);
 350         if (likely (epdata->ep != NULL)) {
 351                 struct usb_request      *req = epdata->req;
 352
 353                 req->context = &done;
 354                 req->complete = epio_complete;
 355                 req->buf = buf;
 356                 req->length = len;
 357                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 358         } else
 359                 value = -ENODEV;
 360         spin_unlock_irq (&epdata->dev->lock);
 361
 362         if (likely (value == 0)) {
 363                 value = wait_event_interruptible (done.wait, done.done);
 364                 if (value != 0) {
 365                         spin_lock_irq (&epdata->dev->lock);
 366                         if (likely (epdata->ep != NULL)) {
 367                                 DBG (epdata->dev, "%s i/o interrupted\n",
 368                                                 epdata->name);
 369                                 usb_ep_dequeue (epdata->ep, epdata->req);
 370                                 spin_unlock_irq (&epdata->dev->lock);
 371
 372                                 wait_event (done.wait, done.done);
 373                                 if (epdata->status == -ECONNRESET)
 374                                         epdata->status = -EINTR;
 375                         } else {
 376                                 spin_unlock_irq (&epdata->dev->lock);
 377
 378                                 DBG (epdata->dev, "endpoint gone\n");
 379                                 epdata->status = -ENODEV;
 380                         }
 381                 }
 382                 return epdata->status;
 383         }
 384         return value;
 385 }
 386
 387
 388 /* handle a synchronous OUT bulk/intr/iso transfer */
 389 static ssize_t
 390 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 391 {
 392         struct ep_data          *data = fd->private_data;
 393         void                    *kbuf;
 394         ssize_t                 value;
 395
 396         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 397                 return value;
 398
 399         /* halt any endpoint by doing a "wrong direction" i/o call */
 400         if (data->desc.bEndpointAddress & USB_DIR_IN) {
 401                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 402                                 == USB_ENDPOINT_XFER_ISOC)
 403                         return -EINVAL;
 404                 DBG (data->dev, "%s halt\n", data->name);
 405                 spin_lock_irq (&data->dev->lock);
 406                 if (likely (data->ep != NULL))
 407                         usb_ep_set_halt (data->ep);
 408                 spin_unlock_irq (&data->dev->lock);
 409                 up (&data->lock);
 410                 return -EBADMSG;
 411         }
 412
 413         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
 414
 415         value = -ENOMEM;
 416         kbuf = kmalloc (len, SLAB_KERNEL);
 417         if (unlikely (!kbuf))
 418                 goto free1;
 419
 420         value = ep_io (data, kbuf, len);
 421         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
 422                 data->name, len, (int) value);
 423         if (value >= 0 && copy_to_user (buf, kbuf, value))
 424                 value = -EFAULT;
 425
 426 free1:
 427         up (&data->lock);
 428         kfree (kbuf);
 429         return value;
 430 }
 431
 432 /* handle a synchronous IN bulk/intr/iso transfer */
 433 static ssize_t
 434 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 435 {
 436         struct ep_data          *data = fd->private_data;
 437         void                    *kbuf;
 438         ssize_t                 value;
 439
 440         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 441                 return value;
 442
 443         /* halt any endpoint by doing a "wrong direction" i/o call */
 444         if (!(data->desc.bEndpointAddress & USB_DIR_IN)) {
 445                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 446                                 == USB_ENDPOINT_XFER_ISOC)
 447                         return -EINVAL;
 448                 DBG (data->dev, "%s halt\n", data->name);
 449                 spin_lock_irq (&data->dev->lock);
 450                 if (likely (data->ep != NULL))
 451                         usb_ep_set_halt (data->ep);
 452                 spin_unlock_irq (&data->dev->lock);
 453                 up (&data->lock);
 454                 return -EBADMSG;
 455         }
 456
 457         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
 458
 459         value = -ENOMEM;
 460         kbuf = kmalloc (len, SLAB_KERNEL);
 461         if (!kbuf)
 462                 goto free1;
 463         if (copy_from_user (kbuf, buf, len)) {
 464                 value = -EFAULT;
 465                 goto free1;
 466         }
 467
 468         value = ep_io (data, kbuf, len);
 469         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
 470                 data->name, len, (int) value);
 471 free1:
 472         up (&data->lock);
 473         kfree (kbuf);
 474         return value;
 475 }
 476
 477 static int
 478 ep_release (struct inode *inode, struct file *fd)
 479 {
 480         struct ep_data          *data = fd->private_data;
 481         int value;
 482
 483         if ((value = down_interruptible(&data->lock)) < 0)
 484                 return value;
 485
 486         /* clean up if this can be reopened */
 487         if (data->state != STATE_EP_UNBOUND) {
 488                 data->state = STATE_EP_DISABLED;
 489                 data->desc.bDescriptorType = 0;
 490                 data->hs_desc.bDescriptorType = 0;
 491                 usb_ep_disable(data->ep);
 492         }
 493         up (&data->lock);
 494         put_ep (data);
 495         return 0;
 496 }
 497
 498 static int ep_ioctl (struct inode *inode, struct file *fd,
 499                 unsigned code, unsigned long value)
 500 {
 501         struct ep_data          *data = fd->private_data;
 502         int                     status;
 503
 504         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 505                 return status;
 506
 507         spin_lock_irq (&data->dev->lock);
 508         if (likely (data->ep != NULL)) {
 509                 switch (code) {
 510                 case GADGETFS_FIFO_STATUS:
 511                         status = usb_ep_fifo_status (data->ep);
 512                         break;
 513                 case GADGETFS_FIFO_FLUSH:
 514                         usb_ep_fifo_flush (data->ep);
 515                         break;
 516                 case GADGETFS_CLEAR_HALT:
 517                         status = usb_ep_clear_halt (data->ep);
 518                         break;
 519                 default:
 520                         status = -ENOTTY;
 521                 }
 522         } else
 523                 status = -ENODEV;
 524         spin_unlock_irq (&data->dev->lock);
 525         up (&data->lock);
 526         return status;
 527 }
 528
 529 /*----------------------------------------------------------------------*/
 530
 531 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 532
 533 struct kiocb_priv {
 534         struct usb_request      *req;
 535         struct ep_data          *epdata;
 536         void                    *buf;
 537         char __user             *ubuf;          /* NULL for writes */
 538         unsigned                actual;
 539 };
 540
 541 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
 542 {
 543         struct kiocb_priv       *priv = iocb->private;
 544         struct ep_data          *epdata;
 545         int                     value;
 546
 547         local_irq_disable();
 548         epdata = priv->epdata;
 549         // spin_lock(&epdata->dev->lock);
 550         kiocbSetCancelled(iocb);
 551         if (likely(epdata && epdata->ep && priv->req))
 552                 value = usb_ep_dequeue (epdata->ep, priv->req);
 553         else
 554                 value = -EINVAL;
 555         // spin_unlock(&epdata->dev->lock);
 556         local_irq_enable();
 557
 558         aio_put_req(iocb);
 559         return value;
 560 }
 561
 562 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
 563 {
 564         struct kiocb_priv       *priv = iocb->private;
 565         ssize_t                 status = priv->actual;
 566
 567         /* we "retry" to get the right mm context for this: */
 568         status = copy_to_user(priv->ubuf, priv->buf, priv->actual);
 569         if (unlikely(0 != status))
 570                 status = -EFAULT;
 571         else
 572                 status = priv->actual;
 573         kfree(priv->buf);
 574         kfree(priv);
 575         return status;
 576 }
 577
 578 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 579 {
 580         struct kiocb            *iocb = req->context;
 581         struct kiocb_priv       *priv = iocb->private;
 582         struct ep_data          *epdata = priv->epdata;
 583
 584         /* lock against disconnect (and ideally, cancel) */
 585         spin_lock(&epdata->dev->lock);
 586         priv->req = NULL;
 587         priv->epdata = NULL;
 588         if (priv->ubuf == NULL
 589                         || unlikely(req->actual == 0)
 590                         || unlikely(kiocbIsCancelled(iocb))) {
 591                 kfree(req->buf);
 592                 kfree(priv);
 593                 iocb->private = NULL;
 594                 /* aio_complete() reports bytes-transferred _and_ faults */
 595                 if (unlikely(kiocbIsCancelled(iocb)))
 596                         aio_put_req(iocb);
 597                 else
 598                         aio_complete(iocb,
 599                                 req->actual ? req->actual : req->status,
 600                                 req->status);
 601         } else {
 602                 /* retry() won't report both; so we hide some faults */
 603                 if (unlikely(0 != req->status))
 604                         DBG(epdata->dev, "%s fault %d len %d\n",
 605                                 ep->name, req->status, req->actual);
 606
 607                 priv->buf = req->buf;
 608                 priv->actual = req->actual;
 609                 kick_iocb(iocb);
 610         }
 611         spin_unlock(&epdata->dev->lock);
 612
 613         usb_ep_free_request(ep, req);
 614         put_ep(epdata);
 615 }
 616
 617 static ssize_t
 618 ep_aio_rwtail(
 619         struct kiocb    *iocb,
 620         char            *buf,
 621         size_t          len,
 622         struct ep_data  *epdata,
 623         char __user     *ubuf
 624 )
 625 {
 626         struct kiocb_priv       *priv;
 627         struct usb_request      *req;
 628         ssize_t                 value;
 629
 630         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 631         if (!priv) {
 632                 value = -ENOMEM;
 633 fail:
 634                 kfree(buf);
 635                 return value;
 636         }
 637         iocb->private = priv;
 638         priv->ubuf = ubuf;
 639
 640         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 641         if (unlikely(value < 0)) {
 642                 kfree(priv);
 643                 goto fail;
 644         }
 645
 646         iocb->ki_cancel = ep_aio_cancel;
 647         get_ep(epdata);
 648         priv->epdata = epdata;
 649         priv->actual = 0;
 650
 651         /* each kiocb is coupled to one usb_request, but we can't
 652          * allocate or submit those if the host disconnected.
 653          */
 654         spin_lock_irq(&epdata->dev->lock);
 655         if (likely(epdata->ep)) {
 656                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 657                 if (likely(req)) {
 658                         priv->req = req;
 659                         req->buf = buf;
 660                         req->length = len;
 661                         req->complete = ep_aio_complete;
 662                         req->context = iocb;
 663                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 664                         if (unlikely(0 != value))
 665                                 usb_ep_free_request(epdata->ep, req);
 666                 } else
 667                         value = -EAGAIN;
 668         } else
 669                 value = -ENODEV;
 670         spin_unlock_irq(&epdata->dev->lock);
 671
 672         up(&epdata->lock);
 673
 674         if (unlikely(value)) {
 675                 kfree(priv);
 676                 put_ep(epdata);
 677         } else
 678                 value = (ubuf ? -EIOCBRETRY : -EIOCBQUEUED);
 679         return value;
 680 }
 681
 682 static ssize_t
 683 ep_aio_read(struct kiocb *iocb, char __user *ubuf, size_t len, loff_t o)
 684 {
 685         struct ep_data          *epdata = iocb->ki_filp->private_data;
 686         char                    *buf;
 687
 688         if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN))
 689                 return -EINVAL;
 690         buf = kmalloc(len, GFP_KERNEL);
 691         if (unlikely(!buf))
 692                 return -ENOMEM;
 693         iocb->ki_retry = ep_aio_read_retry;
 694         return ep_aio_rwtail(iocb, buf, len, epdata, ubuf);
 695 }
 696
 697 static ssize_t
 698 ep_aio_write(struct kiocb *iocb, const char __user *ubuf, size_t len, loff_t o)
 699 {
 700         struct ep_data          *epdata = iocb->ki_filp->private_data;
 701         char                    *buf;
 702
 703         if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN)))
 704                 return -EINVAL;
 705         buf = kmalloc(len, GFP_KERNEL);
 706         if (unlikely(!buf))
 707                 return -ENOMEM;
 708         if (unlikely(copy_from_user(buf, ubuf, len) != 0)) {
 709                 kfree(buf);
 710                 return -EFAULT;
 711         }
 712         return ep_aio_rwtail(iocb, buf, len, epdata, NULL);
 713 }
 714
 715 /*----------------------------------------------------------------------*/
 716
 717 /* used after endpoint configuration */
 718 static const struct file_operations ep_io_operations = {
 719         .owner =        THIS_MODULE,
 720         .llseek =       no_llseek,
 721
 722         .read =         ep_read,
 723         .write =        ep_write,
 724         .ioctl =        ep_ioctl,
 725         .release =      ep_release,
 726
 727         .aio_read =     ep_aio_read,
 728         .aio_write =    ep_aio_write,
 729 };
 730
 731 /* ENDPOINT INITIALIZATION
 732  *
 733  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 734  *     status = write (fd, descriptors, sizeof descriptors)
 735  *
 736  * That write establishes the endpoint configuration, configuring
 737  * the controller to process bulk, interrupt, or isochronous transfers
 738  * at the right maxpacket size, and so on.
 739  *
 740  * The descriptors are message type 1, identified by a host order u32
 741  * at the beginning of what's written.  Descriptor order is: full/low
 742  * speed descriptor, then optional high speed descriptor.
 743  */
 744 static ssize_t
 745 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 746 {
 747         struct ep_data          *data = fd->private_data;
 748         struct usb_ep           *ep;
 749         u32                     tag;
 750         int                     value, length = len;
 751
 752         if ((value = down_interruptible (&data->lock)) < 0)
 753                 return value;
 754
 755         if (data->state != STATE_EP_READY) {
 756                 value = -EL2HLT;
 757                 goto fail;
 758         }
 759
 760         value = len;
 761         if (len < USB_DT_ENDPOINT_SIZE + 4)
 762                 goto fail0;
 763
 764         /* we might need to change message format someday */
 765         if (copy_from_user (&tag, buf, 4)) {
 766                 goto fail1;
 767         }
 768         if (tag != 1) {
 769                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 770                 goto fail0;
 771         }
 772         buf += 4;
 773         len -= 4;
 774
 775         /* NOTE:  audio endpoint extensions not accepted here;
 776          * just don't include the extra bytes.
 777          */
 778
 779         /* full/low speed descriptor, then high speed */
 780         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 781                 goto fail1;
 782         }
 783         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 784                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 785                 goto fail0;
 786         if (len != USB_DT_ENDPOINT_SIZE) {
 787                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 788                         goto fail0;
 789                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 790                                         USB_DT_ENDPOINT_SIZE)) {
 791                         goto fail1;
 792                 }
 793                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 794                                 || data->hs_desc.bDescriptorType
 795                                         != USB_DT_ENDPOINT) {
 796                         DBG(data->dev, "config %s, bad hs length or type\n",
 797                                         data->name);
 798                         goto fail0;
 799                 }
 800         }
 801
 802         spin_lock_irq (&data->dev->lock);
 803         if (data->dev->state == STATE_DEV_UNBOUND) {
 804                 value = -ENOENT;
 805                 goto gone;
 806         } else if ((ep = data->ep) == NULL) {
 807                 value = -ENODEV;
 808                 goto gone;
 809         }
 810         switch (data->dev->gadget->speed) {
 811         case USB_SPEED_LOW:
 812         case USB_SPEED_FULL:
 813                 value = usb_ep_enable (ep, &data->desc);
 814                 if (value == 0)
 815                         data->state = STATE_EP_ENABLED;
 816                 break;
 817 #ifdef  CONFIG_USB_GADGET_DUALSPEED
 818         case USB_SPEED_HIGH:
 819                 /* fails if caller didn't provide that descriptor... */
 820                 value = usb_ep_enable (ep, &data->hs_desc);
 821                 if (value == 0)
 822                         data->state = STATE_EP_ENABLED;
 823                 break;
 824 #endif
 825         default:
 826                 DBG (data->dev, "unconnected, %s init deferred\n",
 827                                 data->name);
 828                 data->state = STATE_EP_DEFER_ENABLE;
 829         }
 830         if (value == 0) {
 831                 fd->f_op = &ep_io_operations;
 832                 value = length;
 833         }
 834 gone:
 835         spin_unlock_irq (&data->dev->lock);
 836         if (value < 0) {
 837 fail:
 838                 data->desc.bDescriptorType = 0;
 839                 data->hs_desc.bDescriptorType = 0;
 840         }
 841         up (&data->lock);
 842         return value;
 843 fail0:
 844         value = -EINVAL;
 845         goto fail;
 846 fail1:
 847         value = -EFAULT;
 848         goto fail;
 849 }
 850
 851 static int
 852 ep_open (struct inode *inode, struct file *fd)
 853 {
 854         struct ep_data          *data = inode->i_private;
 855         int                     value = -EBUSY;
 856
 857         if (down_interruptible (&data->lock) != 0)
 858                 return -EINTR;
 859         spin_lock_irq (&data->dev->lock);
 860         if (data->dev->state == STATE_DEV_UNBOUND)
 861                 value = -ENOENT;
 862         else if (data->state == STATE_EP_DISABLED) {
 863                 value = 0;
 864                 data->state = STATE_EP_READY;
 865                 get_ep (data);
 866                 fd->private_data = data;
 867                 VDEBUG (data->dev, "%s ready\n", data->name);
 868         } else
 869                 DBG (data->dev, "%s state %d\n",
 870                         data->name, data->state);
 871         spin_unlock_irq (&data->dev->lock);
 872         up (&data->lock);
 873         return value;
 874 }
 875
 876 /* used before endpoint configuration */
 877 static const struct file_operations ep_config_operations = {
 878         .owner =        THIS_MODULE,
 879         .llseek =       no_llseek,
 880
 881         .open =         ep_open,
 882         .write =        ep_config,
 883         .release =      ep_release,
 884 };
 885
 886 /*----------------------------------------------------------------------*/
 887
 888 /* EP0 IMPLEMENTATION can be partly in userspace.
 889  *
 890  * Drivers that use this facility receive various events, including
 891  * control requests the kernel doesn't handle.  Drivers that don't
 892  * use this facility may be too simple-minded for real applications.
 893  */
 894
 895 static inline void ep0_readable (struct dev_data *dev)
 896 {
 897         wake_up (&dev->wait);
 898         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 899 }
 900
 901 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 902 {
 903         struct dev_data         *dev = ep->driver_data;
 904
 905         if (req->buf != dev->rbuf) {
 906                 usb_ep_free_buffer (ep, req->buf, req->dma, req->length);
 907                 req->buf = dev->rbuf;
 908                 req->dma = DMA_ADDR_INVALID;
 909         }
 910         req->complete = epio_complete;
 911         dev->setup_out_ready = 0;
 912 }
 913
 914 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 915 {
 916         struct dev_data         *dev = ep->driver_data;
 917         int                     free = 1;
 918
 919         /* for control OUT, data must still get to userspace */
 920         if (!dev->setup_in) {
 921                 dev->setup_out_error = (req->status != 0);
 922                 if (!dev->setup_out_error)
 923                         free = 0;
 924                 dev->setup_out_ready = 1;
 925                 ep0_readable (dev);
 926         } else if (dev->state == STATE_SETUP)
 927                 dev->state = STATE_CONNECTED;
 928
 929         /* clean up as appropriate */
 930         if (free && req->buf != &dev->rbuf)
 931                 clean_req (ep, req);
 932         req->complete = epio_complete;
 933 }
 934
 935 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 936 {
 937         struct dev_data *dev = ep->driver_data;
 938
 939         if (dev->setup_out_ready) {
 940                 DBG (dev, "ep0 request busy!\n");
 941                 return -EBUSY;
 942         }
 943         if (len > sizeof (dev->rbuf))
 944                 req->buf = usb_ep_alloc_buffer (ep, len, &req->dma, GFP_ATOMIC);
 945         if (req->buf == 0) {
 946                 req->buf = dev->rbuf;
 947                 return -ENOMEM;
 948         }
 949         req->complete = ep0_complete;
 950         req->length = len;
 951         req->zero = 0;
 952         return 0;
 953 }
 954
 955 static ssize_t
 956 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 957 {
 958         struct dev_data                 *dev = fd->private_data;
 959         ssize_t                         retval;
 960         enum ep0_state                  state;
 961
 962         spin_lock_irq (&dev->lock);
 963
 964         /* report fd mode change before acting on it */
 965         if (dev->setup_abort) {
 966                 dev->setup_abort = 0;
 967                 retval = -EIDRM;
 968                 goto done;
 969         }
 970
 971         /* control DATA stage */
 972         if ((state = dev->state) == STATE_SETUP) {
 973
 974                 if (dev->setup_in) {            /* stall IN */
 975                         VDEBUG(dev, "ep0in stall\n");
 976                         (void) usb_ep_set_halt (dev->gadget->ep0);
 977                         retval = -EL2HLT;
 978                         dev->state = STATE_CONNECTED;
 979
 980                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
 981                         struct usb_ep           *ep = dev->gadget->ep0;
 982                         struct usb_request      *req = dev->req;
 983
 984                         if ((retval = setup_req (ep, req, 0)) == 0)
 985                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
 986                         dev->state = STATE_CONNECTED;
 987
 988                         /* assume that was SET_CONFIGURATION */
 989                         if (dev->current_config) {
 990                                 unsigned power;
 991 #ifdef  CONFIG_USB_GADGET_DUALSPEED
 992                                 if (dev->gadget->speed == USB_SPEED_HIGH)
 993                                         power = dev->hs_config->bMaxPower;
 994                                 else
 995 #endif
 996                                         power = dev->config->bMaxPower;
 997                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
 998                         }
 999
1000                 } else {                        /* collect OUT data */
1001                         if ((fd->f_flags & O_NONBLOCK) != 0
1002                                         && !dev->setup_out_ready) {
1003                                 retval = -EAGAIN;
1004                                 goto done;
1005                         }
1006                         spin_unlock_irq (&dev->lock);
1007                         retval = wait_event_interruptible (dev->wait,
1008                                         dev->setup_out_ready != 0);
1009
1010                         /* FIXME state could change from under us */
1011                         spin_lock_irq (&dev->lock);
1012                         if (retval)
1013                                 goto done;
1014                         if (dev->setup_out_error)
1015                                 retval = -EIO;
1016                         else {
1017                                 len = min (len, (size_t)dev->req->actual);
1018 // FIXME don't call this with the spinlock held ...
1019                                 if (copy_to_user (buf, &dev->req->buf, len))
1020                                         retval = -EFAULT;
1021                                 clean_req (dev->gadget->ep0, dev->req);
1022                                 /* NOTE userspace can't yet choose to stall */
1023                         }
1024                 }
1025                 goto done;
1026         }
1027
1028         /* else normal: return event data */
1029         if (len < sizeof dev->event [0]) {
1030                 retval = -EINVAL;
1031                 goto done;
1032         }
1033         len -= len % sizeof (struct usb_gadgetfs_event);
1034         dev->usermode_setup = 1;
1035
1036 scan:
1037         /* return queued events right away */
1038         if (dev->ev_next != 0) {
1039                 unsigned                i, n;
1040                 int                     tmp = dev->ev_next;
1041
1042                 len = min (len, tmp * sizeof (struct usb_gadgetfs_event));
1043                 n = len / sizeof (struct usb_gadgetfs_event);
1044
1045                 /* ep0 can't deliver events when STATE_SETUP */
1046                 for (i = 0; i < n; i++) {
1047                         if (dev->event [i].type == GADGETFS_SETUP) {
1048                                 len = i + 1;
1049                                 len *= sizeof (struct usb_gadgetfs_event);
1050                                 n = 0;
1051                                 break;
1052                         }
1053                 }
1054                 spin_unlock_irq (&dev->lock);
1055                 if (copy_to_user (buf, &dev->event, len))
1056                         retval = -EFAULT;
1057                 else
1058                         retval = len;
1059                 if (len > 0) {
1060                         len /= sizeof (struct usb_gadgetfs_event);
1061
1062                         /* NOTE this doesn't guard against broken drivers;
1063                          * concurrent ep0 readers may lose events.
1064                          */
1065                         spin_lock_irq (&dev->lock);
1066                         dev->ev_next -= len;
1067                         if (dev->ev_next != 0)
1068                                 memmove (&dev->event, &dev->event [len],
1069                                         sizeof (struct usb_gadgetfs_event)
1070                                                 * (tmp - len));
1071                         if (n == 0)
1072                                 dev->state = STATE_SETUP;
1073                         spin_unlock_irq (&dev->lock);
1074                 }
1075                 return retval;
1076         }
1077         if (fd->f_flags & O_NONBLOCK) {
1078                 retval = -EAGAIN;
1079                 goto done;
1080         }
1081
1082         switch (state) {
1083         default:
1084                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, state);
1085                 retval = -ESRCH;
1086                 break;
1087         case STATE_UNCONNECTED:
1088         case STATE_CONNECTED:
1089                 spin_unlock_irq (&dev->lock);
1090                 DBG (dev, "%s wait\n", __FUNCTION__);
1091
1092                 /* wait for events */
1093                 retval = wait_event_interruptible (dev->wait,
1094                                 dev->ev_next != 0);
1095                 if (retval < 0)
1096                         return retval;
1097                 spin_lock_irq (&dev->lock);
1098                 goto scan;
1099         }
1100
1101 done:
1102         spin_unlock_irq (&dev->lock);
1103         return retval;
1104 }
1105
1106 static struct usb_gadgetfs_event *
1107 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1108 {
1109         struct usb_gadgetfs_event       *event;
1110         unsigned                        i;
1111
1112         switch (type) {
1113         /* these events purge the queue */
1114         case GADGETFS_DISCONNECT:
1115                 if (dev->state == STATE_SETUP)
1116                         dev->setup_abort = 1;
1117                 // FALL THROUGH
1118         case GADGETFS_CONNECT:
1119                 dev->ev_next = 0;
1120                 break;
1121         case GADGETFS_SETUP:            /* previous request timed out */
1122         case GADGETFS_SUSPEND:          /* same effect */
1123                 /* these events can't be repeated */
1124                 for (i = 0; i != dev->ev_next; i++) {
1125                         if (dev->event [i].type != type)
1126                                 continue;
1127                         DBG (dev, "discard old event %d\n", type);
1128                         dev->ev_next--;
1129                         if (i == dev->ev_next)
1130                                 break;
1131                         /* indices start at zero, for simplicity */
1132                         memmove (&dev->event [i], &dev->event [i + 1],
1133                                 sizeof (struct usb_gadgetfs_event)
1134                                         * (dev->ev_next - i));
1135                 }
1136                 break;
1137         default:
1138                 BUG ();
1139         }
1140         event = &dev->event [dev->ev_next++];
1141         BUG_ON (dev->ev_next > N_EVENT);
1142         VDEBUG (dev, "ev %d, next %d\n", type, dev->ev_next);
1143         memset (event, 0, sizeof *event);
1144         event->type = type;
1145         return event;
1146 }
1147
1148 static ssize_t
1149 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1150 {
1151         struct dev_data         *dev = fd->private_data;
1152         ssize_t                 retval = -ESRCH;
1153
1154         spin_lock_irq (&dev->lock);
1155
1156         /* report fd mode change before acting on it */
1157         if (dev->setup_abort) {
1158                 dev->setup_abort = 0;
1159                 retval = -EIDRM;
1160
1161         /* data and/or status stage for control request */
1162         } else if (dev->state == STATE_SETUP) {
1163
1164                 /* IN DATA+STATUS caller makes len <= wLength */
1165                 if (dev->setup_in) {
1166                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1167                         if (retval == 0) {
1168                                 spin_unlock_irq (&dev->lock);
1169                                 if (copy_from_user (dev->req->buf, buf, len))
1170                                         retval = -EFAULT;
1171                                 else {
1172                                         if (len < dev->setup_wLength)
1173                                                 dev->req->zero = 1;
1174                                         retval = usb_ep_queue (
1175                                                 dev->gadget->ep0, dev->req,
1176                                                 GFP_KERNEL);
1177                                 }
1178                                 if (retval < 0) {
1179                                         spin_lock_irq (&dev->lock);
1180                                         clean_req (dev->gadget->ep0, dev->req);
1181                                         spin_unlock_irq (&dev->lock);
1182                                 } else
1183                                         retval = len;
1184
1185                                 return retval;
1186                         }
1187
1188                 /* can stall some OUT transfers */
1189                 } else if (dev->setup_can_stall) {
1190                         VDEBUG(dev, "ep0out stall\n");
1191                         (void) usb_ep_set_halt (dev->gadget->ep0);
1192                         retval = -EL2HLT;
1193                         dev->state = STATE_CONNECTED;
1194                 } else {
1195                         DBG(dev, "bogus ep0out stall!\n");
1196                 }
1197         } else
1198                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state);
1199
1200         spin_unlock_irq (&dev->lock);
1201         return retval;
1202 }
1203
1204 static int
1205 ep0_fasync (int f, struct file *fd, int on)
1206 {
1207         struct dev_data         *dev = fd->private_data;
1208         // caller must F_SETOWN before signal delivery happens
1209         VDEBUG (dev, "%s %s\n", __FUNCTION__, on ? "on" : "off");
1210         return fasync_helper (f, fd, on, &dev->fasync);
1211 }
1212
1213 static struct usb_gadget_driver gadgetfs_driver;
1214
1215 static int
1216 dev_release (struct inode *inode, struct file *fd)
1217 {
1218         struct dev_data         *dev = fd->private_data;
1219
1220         /* closing ep0 === shutdown all */
1221
1222         usb_gadget_unregister_driver (&gadgetfs_driver);
1223
1224         /* at this point "good" hardware has disconnected the
1225          * device from USB; the host won't see it any more.
1226          * alternatively, all host requests will time out.
1227          */
1228
1229         fasync_helper (-1, fd, 0, &dev->fasync);
1230         kfree (dev->buf);
1231         dev->buf = NULL;
1232         put_dev (dev);
1233
1234         /* other endpoints were all decoupled from this device */
1235         dev->state = STATE_DEV_DISABLED;
1236         return 0;
1237 }
1238
1239 static unsigned int
1240 ep0_poll (struct file *fd, poll_table *wait)
1241 {
1242        struct dev_data         *dev = fd->private_data;
1243        int                     mask = 0;
1244
1245        poll_wait(fd, &dev->wait, wait);
1246
1247        spin_lock_irq (&dev->lock);
1248
1249        /* report fd mode change before acting on it */
1250        if (dev->setup_abort) {
1251                dev->setup_abort = 0;
1252                mask = POLLHUP;
1253                goto out;
1254        }
1255
1256        if (dev->state == STATE_SETUP) {
1257                if (dev->setup_in || dev->setup_can_stall)
1258                        mask = POLLOUT;
1259        } else {
1260                if (dev->ev_next != 0)
1261                        mask = POLLIN;
1262        }
1263 out:
1264        spin_unlock_irq(&dev->lock);
1265        return mask;
1266 }
1267
1268 static int dev_ioctl (struct inode *inode, struct file *fd,
1269                 unsigned code, unsigned long value)
1270 {
1271         struct dev_data         *dev = fd->private_data;
1272         struct usb_gadget       *gadget = dev->gadget;
1273
1274         if (gadget->ops->ioctl)
1275                 return gadget->ops->ioctl (gadget, code, value);
1276         return -ENOTTY;
1277 }
1278
1279 /* used after device configuration */
1280 static const struct file_operations ep0_io_operations = {
1281         .owner =        THIS_MODULE,
1282         .llseek =       no_llseek,
1283
1284         .read =         ep0_read,
1285         .write =        ep0_write,
1286         .fasync =       ep0_fasync,
1287         .poll =         ep0_poll,
1288         .ioctl =        dev_ioctl,
1289         .release =      dev_release,
1290 };
1291
1292 /*----------------------------------------------------------------------*/
1293
1294 /* The in-kernel gadget driver handles most ep0 issues, in particular
1295  * enumerating the single configuration (as provided from user space).
1296  *
1297  * Unrecognized ep0 requests may be handled in user space.
1298  */
1299
1300 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1301 static void make_qualifier (struct dev_data *dev)
1302 {
1303         struct usb_qualifier_descriptor         qual;
1304         struct usb_device_descriptor            *desc;
1305
1306         qual.bLength = sizeof qual;
1307         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1308         qual.bcdUSB = __constant_cpu_to_le16 (0x0200);
1309
1310         desc = dev->dev;
1311         qual.bDeviceClass = desc->bDeviceClass;
1312         qual.bDeviceSubClass = desc->bDeviceSubClass;
1313         qual.bDeviceProtocol = desc->bDeviceProtocol;
1314
1315         /* assumes ep0 uses the same value for both speeds ... */
1316         qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
1317
1318         qual.bNumConfigurations = 1;
1319         qual.bRESERVED = 0;
1320
1321         memcpy (dev->rbuf, &qual, sizeof qual);
1322 }
1323 #endif
1324
1325 static int
1326 config_buf (struct dev_data *dev, u8 type, unsigned index)
1327 {
1328         int             len;
1329 #ifdef CONFIG_USB_GADGET_DUALSPEED
1330         int             hs;
1331 #endif
1332
1333         /* only one configuration */
1334         if (index > 0)
1335                 return -EINVAL;
1336
1337 #ifdef CONFIG_USB_GADGET_DUALSPEED
1338         hs = (dev->gadget->speed == USB_SPEED_HIGH);
1339         if (type == USB_DT_OTHER_SPEED_CONFIG)
1340                 hs = !hs;
1341         if (hs) {
1342                 dev->req->buf = dev->hs_config;
1343                 len = le16_to_cpup (&dev->hs_config->wTotalLength);
1344         } else
1345 #endif
1346         {
1347                 dev->req->buf = dev->config;
1348                 len = le16_to_cpup (&dev->config->wTotalLength);
1349         }
1350         ((u8 *)dev->req->buf) [1] = type;
1351         return len;
1352 }
1353
1354 static int
1355 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1356 {
1357         struct dev_data                 *dev = get_gadget_data (gadget);
1358         struct usb_request              *req = dev->req;
1359         int                             value = -EOPNOTSUPP;
1360         struct usb_gadgetfs_event       *event;
1361         u16                             w_value = le16_to_cpu(ctrl->wValue);
1362         u16                             w_length = le16_to_cpu(ctrl->wLength);
1363
1364         spin_lock (&dev->lock);
1365         dev->setup_abort = 0;
1366         if (dev->state == STATE_UNCONNECTED) {
1367                 struct usb_ep   *ep;
1368                 struct ep_data  *data;
1369
1370                 dev->state = STATE_CONNECTED;
1371                 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1372
1373 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1374                 if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) {
1375                         ERROR (dev, "no high speed config??\n");
1376                         return -EINVAL;
1377                 }
1378 #endif  /* CONFIG_USB_GADGET_DUALSPEED */
1379
1380                 INFO (dev, "connected\n");
1381                 event = next_event (dev, GADGETFS_CONNECT);
1382                 event->u.speed = gadget->speed;
1383                 ep0_readable (dev);
1384
1385                 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
1386                         data = ep->driver_data;
1387                         /* ... down_trylock (&data->lock) ... */
1388                         if (data->state != STATE_EP_DEFER_ENABLE)
1389                                 continue;
1390 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1391                         if (gadget->speed == USB_SPEED_HIGH)
1392                                 value = usb_ep_enable (ep, &data->hs_desc);
1393                         else
1394 #endif  /* CONFIG_USB_GADGET_DUALSPEED */
1395                                 value = usb_ep_enable (ep, &data->desc);
1396                         if (value) {
1397                                 ERROR (dev, "deferred %s enable --> %d\n",
1398                                         data->name, value);
1399                                 continue;
1400                         }
1401                         data->state = STATE_EP_ENABLED;
1402                         wake_up (&data->wait);
1403                         DBG (dev, "woke up %s waiters\n", data->name);
1404                 }
1405
1406         /* host may have given up waiting for response.  we can miss control
1407          * requests handled lower down (device/endpoint status and features);
1408          * then ep0_{read,write} will report the wrong status. controller
1409          * driver will have aborted pending i/o.
1410          */
1411         } else if (dev->state == STATE_SETUP)
1412                 dev->setup_abort = 1;
1413
1414         req->buf = dev->rbuf;
1415         req->dma = DMA_ADDR_INVALID;
1416         req->context = NULL;
1417         value = -EOPNOTSUPP;
1418         switch (ctrl->bRequest) {
1419
1420         case USB_REQ_GET_DESCRIPTOR:
1421                 if (ctrl->bRequestType != USB_DIR_IN)
1422                         goto unrecognized;
1423                 switch (w_value >> 8) {
1424
1425                 case USB_DT_DEVICE:
1426                         value = min (w_length, (u16) sizeof *dev->dev);
1427                         req->buf = dev->dev;
1428                         break;
1429 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1430                 case USB_DT_DEVICE_QUALIFIER:
1431                         if (!dev->hs_config)
1432                                 break;
1433                         value = min (w_length, (u16)
1434                                 sizeof (struct usb_qualifier_descriptor));
1435                         make_qualifier (dev);
1436                         break;
1437                 case USB_DT_OTHER_SPEED_CONFIG:
1438                         // FALLTHROUGH
1439 #endif
1440                 case USB_DT_CONFIG:
1441                         value = config_buf (dev,
1442                                         w_value >> 8,
1443                                         w_value & 0xff);
1444                         if (value >= 0)
1445                                 value = min (w_length, (u16) value);
1446                         break;
1447                 case USB_DT_STRING:
1448                         goto unrecognized;
1449
1450                 default:                // all others are errors
1451                         break;
1452                 }
1453                 break;
1454
1455         /* currently one config, two speeds */
1456         case USB_REQ_SET_CONFIGURATION:
1457                 if (ctrl->bRequestType != 0)
1458                         break;
1459                 if (0 == (u8) w_value) {
1460                         value = 0;
1461                         dev->current_config = 0;
1462                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1463                         // user mode expected to disable endpoints
1464                 } else {
1465                         u8      config, power;
1466 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1467                         if (gadget->speed == USB_SPEED_HIGH) {
1468                                 config = dev->hs_config->bConfigurationValue;
1469                                 power = dev->hs_config->bMaxPower;
1470                         } else
1471 #endif
1472                         {
1473                                 config = dev->config->bConfigurationValue;
1474                                 power = dev->config->bMaxPower;
1475                         }
1476
1477                         if (config == (u8) w_value) {
1478                                 value = 0;
1479                                 dev->current_config = config;
1480                                 usb_gadget_vbus_draw(gadget, 2 * power);
1481                         }
1482                 }
1483
1484                 /* report SET_CONFIGURATION like any other control request,
1485                  * except that usermode may not stall this.  the next
1486                  * request mustn't be allowed start until this finishes:
1487                  * endpoints and threads set up, etc.
1488                  *
1489                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1490                  * has bad/racey automagic that prevents synchronizing here.
1491                  * even kernel mode drivers often miss them.
1492                  */
1493                 if (value == 0) {
1494                         INFO (dev, "configuration #%d\n", dev->current_config);
1495                         if (dev->usermode_setup) {
1496                                 dev->setup_can_stall = 0;
1497                                 goto delegate;
1498                         }
1499                 }
1500                 break;
1501
1502 #ifndef CONFIG_USB_GADGETFS_PXA2XX
1503         /* PXA automagically handles this request too */
1504         case USB_REQ_GET_CONFIGURATION:
1505                 if (ctrl->bRequestType != 0x80)
1506                         break;
1507                 *(u8 *)req->buf = dev->current_config;
1508                 value = min (w_length, (u16) 1);
1509                 break;
1510 #endif
1511
1512         default:
1513 unrecognized:
1514                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1515                         dev->usermode_setup ? "delegate" : "fail",
1516                         ctrl->bRequestType, ctrl->bRequest,
1517                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1518
1519                 /* if there's an ep0 reader, don't stall */
1520                 if (dev->usermode_setup) {
1521                         dev->setup_can_stall = 1;
1522 delegate:
1523                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1524                                                 ? 1 : 0;
1525                         dev->setup_wLength = w_length;
1526                         dev->setup_out_ready = 0;
1527                         dev->setup_out_error = 0;
1528                         value = 0;
1529
1530                         /* read DATA stage for OUT right away */
1531                         if (unlikely (!dev->setup_in && w_length)) {
1532                                 value = setup_req (gadget->ep0, dev->req,
1533                                                         w_length);
1534                                 if (value < 0)
1535                                         break;
1536                                 value = usb_ep_queue (gadget->ep0, dev->req,
1537                                                         GFP_ATOMIC);
1538                                 if (value < 0) {
1539                                         clean_req (gadget->ep0, dev->req);
1540                                         break;
1541                                 }
1542
1543                                 /* we can't currently stall these */
1544                                 dev->setup_can_stall = 0;
1545                         }
1546
1547                         /* state changes when reader collects event */
1548                         event = next_event (dev, GADGETFS_SETUP);
1549                         event->u.setup = *ctrl;
1550                         ep0_readable (dev);
1551                         spin_unlock (&dev->lock);
1552                         return 0;
1553                 }
1554         }
1555
1556         /* proceed with data transfer and status phases? */
1557         if (value >= 0 && dev->state != STATE_SETUP) {
1558                 req->length = value;
1559                 req->zero = value < w_length;
1560                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1561                 if (value < 0) {
1562                         DBG (dev, "ep_queue --> %d\n", value);
1563                         req->status = 0;
1564                 }
1565         }
1566
1567         /* device stalls when value < 0 */
1568         spin_unlock (&dev->lock);
1569         return value;
1570 }
1571
1572 static void destroy_ep_files (struct dev_data *dev)
1573 {
1574         struct list_head        *entry, *tmp;
1575
1576         DBG (dev, "%s %d\n", __FUNCTION__, dev->state);
1577
1578         /* dev->state must prevent interference */
1579 restart:
1580         spin_lock_irq (&dev->lock);
1581         list_for_each_safe (entry, tmp, &dev->epfiles) {
1582                 struct ep_data  *ep;
1583                 struct inode    *parent;
1584                 struct dentry   *dentry;
1585
1586                 /* break link to FS */
1587                 ep = list_entry (entry, struct ep_data, epfiles);
1588                 list_del_init (&ep->epfiles);
1589                 dentry = ep->dentry;
1590                 ep->dentry = NULL;
1591                 parent = dentry->d_parent->d_inode;
1592
1593                 /* break link to controller */
1594                 if (ep->state == STATE_EP_ENABLED)
1595                         (void) usb_ep_disable (ep->ep);
1596                 ep->state = STATE_EP_UNBOUND;
1597                 usb_ep_free_request (ep->ep, ep->req);
1598                 ep->ep = NULL;
1599                 wake_up (&ep->wait);
1600                 put_ep (ep);
1601
1602                 spin_unlock_irq (&dev->lock);
1603
1604                 /* break link to dcache */
1605                 mutex_lock (&parent->i_mutex);
1606                 d_delete (dentry);
1607                 dput (dentry);
1608                 mutex_unlock (&parent->i_mutex);
1609
1610                 /* fds may still be open */
1611                 goto restart;
1612         }
1613         spin_unlock_irq (&dev->lock);
1614 }
1615
1616
1617 static struct inode *
1618 gadgetfs_create_file (struct super_block *sb, char const *name,
1619                 void *data, const struct file_operations *fops,
1620                 struct dentry **dentry_p);
1621
1622 static int activate_ep_files (struct dev_data *dev)
1623 {
1624         struct usb_ep   *ep;
1625         struct ep_data  *data;
1626
1627         gadget_for_each_ep (ep, dev->gadget) {
1628
1629                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1630                 if (!data)
1631                         goto enomem0;
1632                 data->state = STATE_EP_DISABLED;
1633                 init_MUTEX (&data->lock);
1634                 init_waitqueue_head (&data->wait);
1635
1636                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1637                 atomic_set (&data->count, 1);
1638                 data->dev = dev;
1639                 get_dev (dev);
1640
1641                 data->ep = ep;
1642                 ep->driver_data = data;
1643
1644                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1645                 if (!data->req)
1646                         goto enomem1;
1647
1648                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1649                                 data, &ep_config_operations,
1650                                 &data->dentry);
1651                 if (!data->inode)
1652                         goto enomem2;
1653                 list_add_tail (&data->epfiles, &dev->epfiles);
1654         }
1655         return 0;
1656
1657 enomem2:
1658         usb_ep_free_request (ep, data->req);
1659 enomem1:
1660         put_dev (dev);
1661         kfree (data);
1662 enomem0:
1663         DBG (dev, "%s enomem\n", __FUNCTION__);
1664         destroy_ep_files (dev);
1665         return -ENOMEM;
1666 }
1667
1668 static void
1669 gadgetfs_unbind (struct usb_gadget *gadget)
1670 {
1671         struct dev_data         *dev = get_gadget_data (gadget);
1672
1673         DBG (dev, "%s\n", __FUNCTION__);
1674
1675         spin_lock_irq (&dev->lock);
1676         dev->state = STATE_DEV_UNBOUND;
1677         spin_unlock_irq (&dev->lock);
1678
1679         destroy_ep_files (dev);
1680         gadget->ep0->driver_data = NULL;
1681         set_gadget_data (gadget, NULL);
1682
1683         /* we've already been disconnected ... no i/o is active */
1684         if (dev->req)
1685                 usb_ep_free_request (gadget->ep0, dev->req);
1686         DBG (dev, "%s done\n", __FUNCTION__);
1687         put_dev (dev);
1688 }
1689
1690 static struct dev_data          *the_device;
1691
1692 static int
1693 gadgetfs_bind (struct usb_gadget *gadget)
1694 {
1695         struct dev_data         *dev = the_device;
1696
1697         if (!dev)
1698                 return -ESRCH;
1699         if (0 != strcmp (CHIP, gadget->name)) {
1700                 printk (KERN_ERR "%s expected %s controller not %s\n",
1701                         shortname, CHIP, gadget->name);
1702                 return -ENODEV;
1703         }
1704
1705         set_gadget_data (gadget, dev);
1706         dev->gadget = gadget;
1707         gadget->ep0->driver_data = dev;
1708         dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1709
1710         /* preallocate control response and buffer */
1711         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1712         if (!dev->req)
1713                 goto enomem;
1714         dev->req->context = NULL;
1715         dev->req->complete = epio_complete;
1716
1717         if (activate_ep_files (dev) < 0)
1718                 goto enomem;
1719
1720         INFO (dev, "bound to %s driver\n", gadget->name);
1721         dev->state = STATE_UNCONNECTED;
1722         get_dev (dev);
1723         return 0;
1724
1725 enomem:
1726         gadgetfs_unbind (gadget);
1727         return -ENOMEM;
1728 }
1729
1730 static void
1731 gadgetfs_disconnect (struct usb_gadget *gadget)
1732 {
1733         struct dev_data         *dev = get_gadget_data (gadget);
1734
1735         spin_lock (&dev->lock);
1736         if (dev->state == STATE_UNCONNECTED) {
1737                 DBG (dev, "already unconnected\n");
1738                 goto exit;
1739         }
1740         dev->state = STATE_UNCONNECTED;
1741
1742         INFO (dev, "disconnected\n");
1743         next_event (dev, GADGETFS_DISCONNECT);
1744         ep0_readable (dev);
1745 exit:
1746         spin_unlock (&dev->lock);
1747 }
1748
1749 static void
1750 gadgetfs_suspend (struct usb_gadget *gadget)
1751 {
1752         struct dev_data         *dev = get_gadget_data (gadget);
1753
1754         INFO (dev, "suspended from state %d\n", dev->state);
1755         spin_lock (&dev->lock);
1756         switch (dev->state) {
1757         case STATE_SETUP:               // VERY odd... host died??
1758         case STATE_CONNECTED:
1759         case STATE_UNCONNECTED:
1760                 next_event (dev, GADGETFS_SUSPEND);
1761                 ep0_readable (dev);
1762                 /* FALLTHROUGH */
1763         default:
1764                 break;
1765         }
1766         spin_unlock (&dev->lock);
1767 }
1768
1769 static struct usb_gadget_driver gadgetfs_driver = {
1770 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1771         .speed          = USB_SPEED_HIGH,
1772 #else
1773         .speed          = USB_SPEED_FULL,
1774 #endif
1775         .function       = (char *) driver_desc,
1776         .bind           = gadgetfs_bind,
1777         .unbind         = gadgetfs_unbind,
1778         .setup          = gadgetfs_setup,
1779         .disconnect     = gadgetfs_disconnect,
1780         .suspend        = gadgetfs_suspend,
1781
1782         .driver         = {
1783                 .name           = (char *) shortname,
1784         },
1785 };
1786
1787 /*----------------------------------------------------------------------*/
1788
1789 static void gadgetfs_nop(struct usb_gadget *arg) { }
1790
1791 static int gadgetfs_probe (struct usb_gadget *gadget)
1792 {
1793         CHIP = gadget->name;
1794         return -EISNAM;
1795 }
1796
1797 static struct usb_gadget_driver probe_driver = {
1798         .speed          = USB_SPEED_HIGH,
1799         .bind           = gadgetfs_probe,
1800         .unbind         = gadgetfs_nop,
1801         .setup          = (void *)gadgetfs_nop,
1802         .disconnect     = gadgetfs_nop,
1803         .driver         = {
1804                 .name           = "nop",
1805         },
1806 };
1807
1808
1809 /* DEVICE INITIALIZATION
1810  *
1811  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1812  *     status = write (fd, descriptors, sizeof descriptors)
1813  *
1814  * That write establishes the device configuration, so the kernel can
1815  * bind to the controller ... guaranteeing it can handle enumeration
1816  * at all necessary speeds.  Descriptor order is:
1817  *
1818  * . message tag (u32, host order) ... for now, must be zero; it
1819  *      would change to support features like multi-config devices
1820  * . full/low speed config ... all wTotalLength bytes (with interface,
1821  *      class, altsetting, endpoint, and other descriptors)
1822  * . high speed config ... all descriptors, for high speed operation;
1823  *      this one's optional except for high-speed hardware
1824  * . device descriptor
1825  *
1826  * Endpoints are not yet enabled. Drivers may want to immediately
1827  * initialize them, using the /dev/gadget/ep* files that are available
1828  * as soon as the kernel sees the configuration, or they can wait
1829  * until device configuration and interface altsetting changes create
1830  * the need to configure (or unconfigure) them.
1831  *
1832  * After initialization, the device stays active for as long as that
1833  * $CHIP file is open.  Events may then be read from that descriptor,
1834  * such as configuration notifications.  More complex drivers will handle
1835  * some control requests in user space.
1836  */
1837
1838 static int is_valid_config (struct usb_config_descriptor *config)
1839 {
1840         return config->bDescriptorType == USB_DT_CONFIG
1841                 && config->bLength == USB_DT_CONFIG_SIZE
1842                 && config->bConfigurationValue != 0
1843                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1844                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1845         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1846         /* FIXME check lengths: walk to end */
1847 }
1848
1849 static ssize_t
1850 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1851 {
1852         struct dev_data         *dev = fd->private_data;
1853         ssize_t                 value = len, length = len;
1854         unsigned                total;
1855         u32                     tag;
1856         char                    *kbuf;
1857
1858         if (dev->state != STATE_OPENED)
1859                 return -EEXIST;
1860
1861         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1862                 return -EINVAL;
1863
1864         /* we might need to change message format someday */
1865         if (copy_from_user (&tag, buf, 4))
1866                 return -EFAULT;
1867         if (tag != 0)
1868                 return -EINVAL;
1869         buf += 4;
1870         length -= 4;
1871
1872         kbuf = kmalloc (length, SLAB_KERNEL);
1873         if (!kbuf)
1874                 return -ENOMEM;
1875         if (copy_from_user (kbuf, buf, length)) {
1876                 kfree (kbuf);
1877                 return -EFAULT;
1878         }
1879
1880         spin_lock_irq (&dev->lock);
1881         value = -EINVAL;
1882         if (dev->buf)
1883                 goto fail;
1884         dev->buf = kbuf;
1885
1886         /* full or low speed config */
1887         dev->config = (void *) kbuf;
1888         total = le16_to_cpup (&dev->config->wTotalLength);
1889         if (!is_valid_config (dev->config) || total >= length)
1890                 goto fail;
1891         kbuf += total;
1892         length -= total;
1893
1894         /* optional high speed config */
1895         if (kbuf [1] == USB_DT_CONFIG) {
1896                 dev->hs_config = (void *) kbuf;
1897                 total = le16_to_cpup (&dev->hs_config->wTotalLength);
1898                 if (!is_valid_config (dev->hs_config) || total >= length)
1899                         goto fail;
1900                 kbuf += total;
1901                 length -= total;
1902         }
1903
1904         /* could support multiple configs, using another encoding! */
1905
1906         /* device descriptor (tweaked for paranoia) */
1907         if (length != USB_DT_DEVICE_SIZE)
1908                 goto fail;
1909         dev->dev = (void *)kbuf;
1910         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1911                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1912                         || dev->dev->bNumConfigurations != 1)
1913                 goto fail;
1914         dev->dev->bNumConfigurations = 1;
1915         dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200);
1916
1917         /* triggers gadgetfs_bind(); then we can enumerate. */
1918         spin_unlock_irq (&dev->lock);
1919         value = usb_gadget_register_driver (&gadgetfs_driver);
1920         if (value != 0) {
1921                 kfree (dev->buf);
1922                 dev->buf = NULL;
1923         } else {
1924                 /* at this point "good" hardware has for the first time
1925                  * let the USB the host see us.  alternatively, if users
1926                  * unplug/replug that will clear all the error state.
1927                  *
1928                  * note:  everything running before here was guaranteed
1929                  * to choke driver model style diagnostics.  from here
1930                  * on, they can work ... except in cleanup paths that
1931                  * kick in after the ep0 descriptor is closed.
1932                  */
1933                 fd->f_op = &ep0_io_operations;
1934                 value = len;
1935         }
1936         return value;
1937
1938 fail:
1939         spin_unlock_irq (&dev->lock);
1940         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __FUNCTION__, value, dev);
1941         kfree (dev->buf);
1942         dev->buf = NULL;
1943         return value;
1944 }
1945
1946 static int
1947 dev_open (struct inode *inode, struct file *fd)
1948 {
1949         struct dev_data         *dev = inode->i_private;
1950         int                     value = -EBUSY;
1951
1952         if (dev->state == STATE_DEV_DISABLED) {
1953                 dev->ev_next = 0;
1954                 dev->state = STATE_OPENED;
1955                 fd->private_data = dev;
1956                 get_dev (dev);
1957                 value = 0;
1958         }
1959         return value;
1960 }
1961
1962 static const struct file_operations dev_init_operations = {
1963         .owner =        THIS_MODULE,
1964         .llseek =       no_llseek,
1965
1966         .open =         dev_open,
1967         .write =        dev_config,
1968         .fasync =       ep0_fasync,
1969         .ioctl =        dev_ioctl,
1970         .release =      dev_release,
1971 };
1972
1973 /*----------------------------------------------------------------------*/
1974
1975 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1976  *
1977  * Mounting the filesystem creates a controller file, used first for
1978  * device configuration then later for event monitoring.
1979  */
1980
1981
1982 /* FIXME PAM etc could set this security policy without mount options
1983  * if epfiles inherited ownership and permissons from ep0 ...
1984  */
1985
1986 static unsigned default_uid;
1987 static unsigned default_gid;
1988 static unsigned default_perm = S_IRUSR | S_IWUSR;
1989
1990 module_param (default_uid, uint, 0644);
1991 module_param (default_gid, uint, 0644);
1992 module_param (default_perm, uint, 0644);
1993
1994
1995 static struct inode *
1996 gadgetfs_make_inode (struct super_block *sb,
1997                 void *data, const struct file_operations *fops,
1998                 int mode)
1999 {
2000         struct inode *inode = new_inode (sb);
2001
2002         if (inode) {
2003                 inode->i_mode = mode;
2004                 inode->i_uid = default_uid;
2005                 inode->i_gid = default_gid;
2006                 inode->i_blocks = 0;
2007                 inode->i_atime = inode->i_mtime = inode->i_ctime
2008                                 = CURRENT_TIME;
2009                 inode->i_private = data;
2010                 inode->i_fop = fops;
2011         }
2012         return inode;
2013 }
2014
2015 /* creates in fs root directory, so non-renamable and non-linkable.
2016  * so inode and dentry are paired, until device reconfig.
2017  */
2018 static struct inode *
2019 gadgetfs_create_file (struct super_block *sb, char const *name,
2020                 void *data, const struct file_operations *fops,
2021                 struct dentry **dentry_p)
2022 {
2023         struct dentry   *dentry;
2024         struct inode    *inode;
2025
2026         dentry = d_alloc_name(sb->s_root, name);
2027         if (!dentry)
2028                 return NULL;
2029
2030         inode = gadgetfs_make_inode (sb, data, fops,
2031                         S_IFREG | (default_perm & S_IRWXUGO));
2032         if (!inode) {
2033                 dput(dentry);
2034                 return NULL;
2035         }
2036         d_add (dentry, inode);
2037         *dentry_p = dentry;
2038         return inode;
2039 }
2040
2041 static struct super_operations gadget_fs_operations = {
2042         .statfs =       simple_statfs,
2043         .drop_inode =   generic_delete_inode,
2044 };
2045
2046 static int
2047 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2048 {
2049         struct inode    *inode;
2050         struct dentry   *d;
2051         struct dev_data *dev;
2052
2053         if (the_device)
2054                 return -ESRCH;
2055
2056         /* fake probe to determine $CHIP */
2057         (void) usb_gadget_register_driver (&probe_driver);
2058         if (!CHIP)
2059                 return -ENODEV;
2060
2061         /* superblock */
2062         sb->s_blocksize = PAGE_CACHE_SIZE;
2063         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2064         sb->s_magic = GADGETFS_MAGIC;
2065         sb->s_op = &gadget_fs_operations;
2066         sb->s_time_gran = 1;
2067
2068         /* root inode */
2069         inode = gadgetfs_make_inode (sb,
2070                         NULL, &simple_dir_operations,
2071                         S_IFDIR | S_IRUGO | S_IXUGO);
2072         if (!inode)
2073                 goto enomem0;
2074         inode->i_op = &simple_dir_inode_operations;
2075         if (!(d = d_alloc_root (inode)))
2076                 goto enomem1;
2077         sb->s_root = d;
2078
2079         /* the ep0 file is named after the controller we expect;
2080          * user mode code can use it for sanity checks, like we do.
2081          */
2082         dev = dev_new ();
2083         if (!dev)
2084                 goto enomem2;
2085
2086         dev->sb = sb;
2087         if (!gadgetfs_create_file (sb, CHIP,
2088                                 dev, &dev_init_operations,
2089                                 &dev->dentry))
2090                 goto enomem3;
2091
2092         /* other endpoint files are available after hardware setup,
2093          * from binding to a controller.
2094          */
2095         the_device = dev;
2096         return 0;
2097
2098 enomem3:
2099         put_dev (dev);
2100 enomem2:
2101         dput (d);
2102 enomem1:
2103         iput (inode);
2104 enomem0:
2105         return -ENOMEM;
2106 }
2107
2108 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2109 static int
2110 gadgetfs_get_sb (struct file_system_type *t, int flags,
2111                 const char *path, void *opts, struct vfsmount *mnt)
2112 {
2113         return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt);
2114 }
2115
2116 static void
2117 gadgetfs_kill_sb (struct super_block *sb)
2118 {
2119         kill_litter_super (sb);
2120         if (the_device) {
2121                 put_dev (the_device);
2122                 the_device = NULL;
2123         }
2124 }
2125
2126 /*----------------------------------------------------------------------*/
2127
2128 static struct file_system_type gadgetfs_type = {
2129         .owner          = THIS_MODULE,
2130         .name           = shortname,
2131         .get_sb         = gadgetfs_get_sb,
2132         .kill_sb        = gadgetfs_kill_sb,
2133 };
2134
2135 /*----------------------------------------------------------------------*/
2136
2137 static int __init init (void)
2138 {
2139         int status;
2140
2141         status = register_filesystem (&gadgetfs_type);
2142         if (status == 0)
2143                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2144                         shortname, driver_desc);
2145         return status;
2146 }
2147 module_init (init);
2148
2149 static void __exit cleanup (void)
2150 {
2151         pr_debug ("unregister %s\n", shortname);
2152         unregister_filesystem (&gadgetfs_type);
2153 }
2154 module_exit (cleanup);
2155