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   1 /*
   2  * inode.c -- user mode filesystem api for usb gadget controllers
   3  *
   4  * Copyright (C) 2003-2004 David Brownell
   5  * Copyright (C) 2003 Agilent Technologies
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22
  23 // #define      DEBUG                   /* data to help fault diagnosis */
  24 // #define      VERBOSE         /* extra debug messages (success too) */
  25
  26 #include <linux/init.h>
  27 #include <linux/module.h>
  28 #include <linux/fs.h>
  29 #include <linux/pagemap.h>
  30 #include <linux/uts.h>
  31 #include <linux/wait.h>
  32 #include <linux/compiler.h>
  33 #include <asm/uaccess.h>
  34 #include <linux/slab.h>
  35 #include <linux/poll.h>
  36
  37 #include <linux/device.h>
  38 #include <linux/moduleparam.h>
  39
  40 #include <linux/usb_gadgetfs.h>
  41 #include <linux/usb_gadget.h>
  42
  43
  44 /*
  45  * The gadgetfs API maps each endpoint to a file descriptor so that you
  46  * can use standard synchronous read/write calls for I/O.  There's some
  47  * O_NONBLOCK and O_ASYNC/FASYNC style i/o support.  Example usermode
  48  * drivers show how this works in practice.  You can also use AIO to
  49  * eliminate I/O gaps between requests, to help when streaming data.
  50  *
  51  * Key parts that must be USB-specific are protocols defining how the
  52  * read/write operations relate to the hardware state machines.  There
  53  * are two types of files.  One type is for the device, implementing ep0.
  54  * The other type is for each IN or OUT endpoint.  In both cases, the
  55  * user mode driver must configure the hardware before using it.
  56  *
  57  * - First, dev_config() is called when /dev/gadget/$CHIP is configured
  58  *   (by writing configuration and device descriptors).  Afterwards it
  59  *   may serve as a source of device events, used to handle all control
  60  *   requests other than basic enumeration.
  61  *
  62  * - Then either immediately, or after a SET_CONFIGURATION control request,
  63  *   ep_config() is called when each /dev/gadget/ep* file is configured
  64  *   (by writing endpoint descriptors).  Afterwards these files are used
  65  *   to write() IN data or to read() OUT data.  To halt the endpoint, a
  66  *   "wrong direction" request is issued (like reading an IN endpoint).
  67  *
  68  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
  69  * not possible on all hardware.  For example, precise fault handling with
  70  * respect to data left in endpoint fifos after aborted operations; or
  71  * selective clearing of endpoint halts, to implement SET_INTERFACE.
  72  */
  73
  74 #define DRIVER_DESC     "USB Gadget filesystem"
  75 #define DRIVER_VERSION  "24 Aug 2004"
  76
  77 static const char driver_desc [] = DRIVER_DESC;
  78 static const char shortname [] = "gadgetfs";
  79
  80 MODULE_DESCRIPTION (DRIVER_DESC);
  81 MODULE_AUTHOR ("David Brownell");
  82 MODULE_LICENSE ("GPL");
  83
  84
  85 /*----------------------------------------------------------------------*/
  86
  87 #define GADGETFS_MAGIC          0xaee71ee7
  88 #define DMA_ADDR_INVALID        (~(dma_addr_t)0)
  89
  90 /* /dev/gadget/$CHIP represents ep0 and the whole device */
  91 enum ep0_state {
  92         /* DISBLED is the initial state.
  93          */
  94         STATE_DEV_DISABLED = 0,
  95
  96         /* Only one open() of /dev/gadget/$CHIP; only one file tracks
  97          * ep0/device i/o modes and binding to the controller.  Driver
  98          * must always write descriptors to initialize the device, then
  99          * the device becomes UNCONNECTED until enumeration.
 100          */
 101         STATE_OPENED,
 102
 103         /* From then on, ep0 fd is in either of two basic modes:
 104          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
 105          * - SETUP: read/write will transfer control data and succeed;
 106          *   or if "wrong direction", performs protocol stall
 107          */
 108         STATE_UNCONNECTED,
 109         STATE_CONNECTED,
 110         STATE_SETUP,
 111
 112         /* UNBOUND means the driver closed ep0, so the device won't be
 113          * accessible again (DEV_DISABLED) until all fds are closed.
 114          */
 115         STATE_DEV_UNBOUND,
 116 };
 117
 118 /* enough for the whole queue: most events invalidate others */
 119 #define N_EVENT                 5
 120
 121 struct dev_data {
 122         spinlock_t                      lock;
 123         atomic_t                        count;
 124         enum ep0_state                  state;
 125         struct usb_gadgetfs_event       event [N_EVENT];
 126         unsigned                        ev_next;
 127         struct fasync_struct            *fasync;
 128         u8                              current_config;
 129
 130         /* drivers reading ep0 MUST handle control requests (SETUP)
 131          * reported that way; else the host will time out.
 132          */
 133         unsigned                        usermode_setup : 1,
 134                                         setup_in : 1,
 135                                         setup_can_stall : 1,
 136                                         setup_out_ready : 1,
 137                                         setup_out_error : 1,
 138                                         setup_abort : 1;
 139         unsigned                        setup_wLength;
 140
 141         /* the rest is basically write-once */
 142         struct usb_config_descriptor    *config, *hs_config;
 143         struct usb_device_descriptor    *dev;
 144         struct usb_request              *req;
 145         struct usb_gadget               *gadget;
 146         struct list_head                epfiles;
 147         void                            *buf;
 148         wait_queue_head_t               wait;
 149         struct super_block              *sb;
 150         struct dentry                   *dentry;
 151
 152         /* except this scratch i/o buffer for ep0 */
 153         u8                              rbuf [256];
 154 };
 155
 156 static inline void get_dev (struct dev_data *data)
 157 {
 158         atomic_inc (&data->count);
 159 }
 160
 161 static void put_dev (struct dev_data *data)
 162 {
 163         if (likely (!atomic_dec_and_test (&data->count)))
 164                 return;
 165         /* needs no more cleanup */
 166         BUG_ON (waitqueue_active (&data->wait));
 167         kfree (data);
 168 }
 169
 170 static struct dev_data *dev_new (void)
 171 {
 172         struct dev_data         *dev;
 173
 174         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 175         if (!dev)
 176                 return NULL;
 177         dev->state = STATE_DEV_DISABLED;
 178         atomic_set (&dev->count, 1);
 179         spin_lock_init (&dev->lock);
 180         INIT_LIST_HEAD (&dev->epfiles);
 181         init_waitqueue_head (&dev->wait);
 182         return dev;
 183 }
 184
 185 /*----------------------------------------------------------------------*/
 186
 187 /* other /dev/gadget/$ENDPOINT files represent endpoints */
 188 enum ep_state {
 189         STATE_EP_DISABLED = 0,
 190         STATE_EP_READY,
 191         STATE_EP_DEFER_ENABLE,
 192         STATE_EP_ENABLED,
 193         STATE_EP_UNBOUND,
 194 };
 195
 196 struct ep_data {
 197         struct semaphore                lock;
 198         enum ep_state                   state;
 199         atomic_t                        count;
 200         struct dev_data                 *dev;
 201         /* must hold dev->lock before accessing ep or req */
 202         struct usb_ep                   *ep;
 203         struct usb_request              *req;
 204         ssize_t                         status;
 205         char                            name [16];
 206         struct usb_endpoint_descriptor  desc, hs_desc;
 207         struct list_head                epfiles;
 208         wait_queue_head_t               wait;
 209         struct dentry                   *dentry;
 210         struct inode                    *inode;
 211 };
 212
 213 static inline void get_ep (struct ep_data *data)
 214 {
 215         atomic_inc (&data->count);
 216 }
 217
 218 static void put_ep (struct ep_data *data)
 219 {
 220         if (likely (!atomic_dec_and_test (&data->count)))
 221                 return;
 222         put_dev (data->dev);
 223         /* needs no more cleanup */
 224         BUG_ON (!list_empty (&data->epfiles));
 225         BUG_ON (waitqueue_active (&data->wait));
 226         kfree (data);
 227 }
 228
 229 /*----------------------------------------------------------------------*/
 230
 231 /* most "how to use the hardware" policy choices are in userspace:
 232  * mapping endpoint roles (which the driver needs) to the capabilities
 233  * which the usb controller has.  most of those capabilities are exposed
 234  * implicitly, starting with the driver name and then endpoint names.
 235  */
 236
 237 static const char *CHIP;
 238
 239 /*----------------------------------------------------------------------*/
 240
 241 /* NOTE:  don't use dev_printk calls before binding to the gadget
 242  * at the end of ep0 configuration, or after unbind.
 243  */
 244
 245 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
 246 #define xprintk(d,level,fmt,args...) \
 247         printk(level "%s: " fmt , shortname , ## args)
 248
 249 #ifdef DEBUG
 250 #define DBG(dev,fmt,args...) \
 251         xprintk(dev , KERN_DEBUG , fmt , ## args)
 252 #else
 253 #define DBG(dev,fmt,args...) \
 254         do { } while (0)
 255 #endif /* DEBUG */
 256
 257 #ifdef VERBOSE
 258 #define VDEBUG  DBG
 259 #else
 260 #define VDEBUG(dev,fmt,args...) \
 261         do { } while (0)
 262 #endif /* DEBUG */
 263
 264 #define ERROR(dev,fmt,args...) \
 265         xprintk(dev , KERN_ERR , fmt , ## args)
 266 #define WARN(dev,fmt,args...) \
 267         xprintk(dev , KERN_WARNING , fmt , ## args)
 268 #define INFO(dev,fmt,args...) \
 269         xprintk(dev , KERN_INFO , fmt , ## args)
 270
 271
 272 /*----------------------------------------------------------------------*/
 273
 274 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 275  *
 276  * After opening, configure non-control endpoints.  Then use normal
 277  * stream read() and write() requests; and maybe ioctl() to get more
 278  * precise FIFO status when recovering from cancellation.
 279  */
 280
 281 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 282 {
 283         struct ep_data  *epdata = ep->driver_data;
 284
 285         if (!req->context)
 286                 return;
 287         if (req->status)
 288                 epdata->status = req->status;
 289         else
 290                 epdata->status = req->actual;
 291         complete ((struct completion *)req->context);
 292 }
 293
 294 /* tasklock endpoint, returning when it's connected.
 295  * still need dev->lock to use epdata->ep.
 296  */
 297 static int
 298 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
 299 {
 300         int     val;
 301
 302         if (f_flags & O_NONBLOCK) {
 303                 if (down_trylock (&epdata->lock) != 0)
 304                         goto nonblock;
 305                 if (epdata->state != STATE_EP_ENABLED) {
 306                         up (&epdata->lock);
 307 nonblock:
 308                         val = -EAGAIN;
 309                 } else
 310                         val = 0;
 311                 return val;
 312         }
 313
 314         if ((val = down_interruptible (&epdata->lock)) < 0)
 315                 return val;
 316 newstate:
 317         switch (epdata->state) {
 318         case STATE_EP_ENABLED:
 319                 break;
 320         case STATE_EP_DEFER_ENABLE:
 321                 DBG (epdata->dev, "%s wait for host\n", epdata->name);
 322                 if ((val = wait_event_interruptible (epdata->wait,
 323                                 epdata->state != STATE_EP_DEFER_ENABLE
 324                                 || epdata->dev->state == STATE_DEV_UNBOUND
 325                                 )) < 0)
 326                         goto fail;
 327                 goto newstate;
 328         // case STATE_EP_DISABLED:              /* "can't happen" */
 329         // case STATE_EP_READY:                 /* "can't happen" */
 330         default:                                /* error! */
 331                 pr_debug ("%s: ep %p not available, state %d\n",
 332                                 shortname, epdata, epdata->state);
 333                 // FALLTHROUGH
 334         case STATE_EP_UNBOUND:                  /* clean disconnect */
 335                 val = -ENODEV;
 336 fail:
 337                 up (&epdata->lock);
 338         }
 339         return val;
 340 }
 341
 342 static ssize_t
 343 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 344 {
 345         DECLARE_COMPLETION_ONSTACK (done);
 346         int value;
 347
 348         spin_lock_irq (&epdata->dev->lock);
 349         if (likely (epdata->ep != NULL)) {
 350                 struct usb_request      *req = epdata->req;
 351
 352                 req->context = &done;
 353                 req->complete = epio_complete;
 354                 req->buf = buf;
 355                 req->length = len;
 356                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 357         } else
 358                 value = -ENODEV;
 359         spin_unlock_irq (&epdata->dev->lock);
 360
 361         if (likely (value == 0)) {
 362                 value = wait_event_interruptible (done.wait, done.done);
 363                 if (value != 0) {
 364                         spin_lock_irq (&epdata->dev->lock);
 365                         if (likely (epdata->ep != NULL)) {
 366                                 DBG (epdata->dev, "%s i/o interrupted\n",
 367                                                 epdata->name);
 368                                 usb_ep_dequeue (epdata->ep, epdata->req);
 369                                 spin_unlock_irq (&epdata->dev->lock);
 370
 371                                 wait_event (done.wait, done.done);
 372                                 if (epdata->status == -ECONNRESET)
 373                                         epdata->status = -EINTR;
 374                         } else {
 375                                 spin_unlock_irq (&epdata->dev->lock);
 376
 377                                 DBG (epdata->dev, "endpoint gone\n");
 378                                 epdata->status = -ENODEV;
 379                         }
 380                 }
 381                 return epdata->status;
 382         }
 383         return value;
 384 }
 385
 386
 387 /* handle a synchronous OUT bulk/intr/iso transfer */
 388 static ssize_t
 389 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 390 {
 391         struct ep_data          *data = fd->private_data;
 392         void                    *kbuf;
 393         ssize_t                 value;
 394
 395         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 396                 return value;
 397
 398         /* halt any endpoint by doing a "wrong direction" i/o call */
 399         if (data->desc.bEndpointAddress & USB_DIR_IN) {
 400                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 401                                 == USB_ENDPOINT_XFER_ISOC)
 402                         return -EINVAL;
 403                 DBG (data->dev, "%s halt\n", data->name);
 404                 spin_lock_irq (&data->dev->lock);
 405                 if (likely (data->ep != NULL))
 406                         usb_ep_set_halt (data->ep);
 407                 spin_unlock_irq (&data->dev->lock);
 408                 up (&data->lock);
 409                 return -EBADMSG;
 410         }
 411
 412         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
 413
 414         value = -ENOMEM;
 415         kbuf = kmalloc (len, GFP_KERNEL);
 416         if (unlikely (!kbuf))
 417                 goto free1;
 418
 419         value = ep_io (data, kbuf, len);
 420         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
 421                 data->name, len, (int) value);
 422         if (value >= 0 && copy_to_user (buf, kbuf, value))
 423                 value = -EFAULT;
 424
 425 free1:
 426         up (&data->lock);
 427         kfree (kbuf);
 428         return value;
 429 }
 430
 431 /* handle a synchronous IN bulk/intr/iso transfer */
 432 static ssize_t
 433 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 434 {
 435         struct ep_data          *data = fd->private_data;
 436         void                    *kbuf;
 437         ssize_t                 value;
 438
 439         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 440                 return value;
 441
 442         /* halt any endpoint by doing a "wrong direction" i/o call */
 443         if (!(data->desc.bEndpointAddress & USB_DIR_IN)) {
 444                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 445                                 == USB_ENDPOINT_XFER_ISOC)
 446                         return -EINVAL;
 447                 DBG (data->dev, "%s halt\n", data->name);
 448                 spin_lock_irq (&data->dev->lock);
 449                 if (likely (data->ep != NULL))
 450                         usb_ep_set_halt (data->ep);
 451                 spin_unlock_irq (&data->dev->lock);
 452                 up (&data->lock);
 453                 return -EBADMSG;
 454         }
 455
 456         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
 457
 458         value = -ENOMEM;
 459         kbuf = kmalloc (len, GFP_KERNEL);
 460         if (!kbuf)
 461                 goto free1;
 462         if (copy_from_user (kbuf, buf, len)) {
 463                 value = -EFAULT;
 464                 goto free1;
 465         }
 466
 467         value = ep_io (data, kbuf, len);
 468         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
 469                 data->name, len, (int) value);
 470 free1:
 471         up (&data->lock);
 472         kfree (kbuf);
 473         return value;
 474 }
 475
 476 static int
 477 ep_release (struct inode *inode, struct file *fd)
 478 {
 479         struct ep_data          *data = fd->private_data;
 480         int value;
 481
 482         if ((value = down_interruptible(&data->lock)) < 0)
 483                 return value;
 484
 485         /* clean up if this can be reopened */
 486         if (data->state != STATE_EP_UNBOUND) {
 487                 data->state = STATE_EP_DISABLED;
 488                 data->desc.bDescriptorType = 0;
 489                 data->hs_desc.bDescriptorType = 0;
 490                 usb_ep_disable(data->ep);
 491         }
 492         up (&data->lock);
 493         put_ep (data);
 494         return 0;
 495 }
 496
 497 static int ep_ioctl (struct inode *inode, struct file *fd,
 498                 unsigned code, unsigned long value)
 499 {
 500         struct ep_data          *data = fd->private_data;
 501         int                     status;
 502
 503         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 504                 return status;
 505
 506         spin_lock_irq (&data->dev->lock);
 507         if (likely (data->ep != NULL)) {
 508                 switch (code) {
 509                 case GADGETFS_FIFO_STATUS:
 510                         status = usb_ep_fifo_status (data->ep);
 511                         break;
 512                 case GADGETFS_FIFO_FLUSH:
 513                         usb_ep_fifo_flush (data->ep);
 514                         break;
 515                 case GADGETFS_CLEAR_HALT:
 516                         status = usb_ep_clear_halt (data->ep);
 517                         break;
 518                 default:
 519                         status = -ENOTTY;
 520                 }
 521         } else
 522                 status = -ENODEV;
 523         spin_unlock_irq (&data->dev->lock);
 524         up (&data->lock);
 525         return status;
 526 }
 527
 528 /*----------------------------------------------------------------------*/
 529
 530 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 531
 532 struct kiocb_priv {
 533         struct usb_request      *req;
 534         struct ep_data          *epdata;
 535         void                    *buf;
 536         const struct iovec      *iv;
 537         unsigned long           nr_segs;
 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                 len, total;
 566         int                     i;
 567
 568         /* we "retry" to get the right mm context for this: */
 569
 570         /* copy stuff into user buffers */
 571         total = priv->actual;
 572         len = 0;
 573         for (i=0; i < priv->nr_segs; i++) {
 574                 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
 575
 576                 if (copy_to_user(priv->iv[i].iov_base, priv->buf, this)) {
 577                         if (len == 0)
 578                                 len = -EFAULT;
 579                         break;
 580                 }
 581
 582                 total -= this;
 583                 len += this;
 584                 if (total == 0)
 585                         break;
 586         }
 587         kfree(priv->buf);
 588         kfree(priv);
 589         aio_put_req(iocb);
 590         return len;
 591 }
 592
 593 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 594 {
 595         struct kiocb            *iocb = req->context;
 596         struct kiocb_priv       *priv = iocb->private;
 597         struct ep_data          *epdata = priv->epdata;
 598
 599         /* lock against disconnect (and ideally, cancel) */
 600         spin_lock(&epdata->dev->lock);
 601         priv->req = NULL;
 602         priv->epdata = NULL;
 603         if (priv->iv == NULL
 604                         || unlikely(req->actual == 0)
 605                         || unlikely(kiocbIsCancelled(iocb))) {
 606                 kfree(req->buf);
 607                 kfree(priv);
 608                 iocb->private = NULL;
 609                 /* aio_complete() reports bytes-transferred _and_ faults */
 610                 if (unlikely(kiocbIsCancelled(iocb)))
 611                         aio_put_req(iocb);
 612                 else
 613                         aio_complete(iocb,
 614                                 req->actual ? req->actual : req->status,
 615                                 req->status);
 616         } else {
 617                 /* retry() won't report both; so we hide some faults */
 618                 if (unlikely(0 != req->status))
 619                         DBG(epdata->dev, "%s fault %d len %d\n",
 620                                 ep->name, req->status, req->actual);
 621
 622                 priv->buf = req->buf;
 623                 priv->actual = req->actual;
 624                 kick_iocb(iocb);
 625         }
 626         spin_unlock(&epdata->dev->lock);
 627
 628         usb_ep_free_request(ep, req);
 629         put_ep(epdata);
 630 }
 631
 632 static ssize_t
 633 ep_aio_rwtail(
 634         struct kiocb    *iocb,
 635         char            *buf,
 636         size_t          len,
 637         struct ep_data  *epdata,
 638         const struct iovec *iv,
 639         unsigned long   nr_segs
 640 )
 641 {
 642         struct kiocb_priv       *priv;
 643         struct usb_request      *req;
 644         ssize_t                 value;
 645
 646         priv = kmalloc(sizeof *priv, GFP_KERNEL);
 647         if (!priv) {
 648                 value = -ENOMEM;
 649 fail:
 650                 kfree(buf);
 651                 return value;
 652         }
 653         iocb->private = priv;
 654         priv->iv = iv;
 655         priv->nr_segs = nr_segs;
 656
 657         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 658         if (unlikely(value < 0)) {
 659                 kfree(priv);
 660                 goto fail;
 661         }
 662
 663         iocb->ki_cancel = ep_aio_cancel;
 664         get_ep(epdata);
 665         priv->epdata = epdata;
 666         priv->actual = 0;
 667
 668         /* each kiocb is coupled to one usb_request, but we can't
 669          * allocate or submit those if the host disconnected.
 670          */
 671         spin_lock_irq(&epdata->dev->lock);
 672         if (likely(epdata->ep)) {
 673                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 674                 if (likely(req)) {
 675                         priv->req = req;
 676                         req->buf = buf;
 677                         req->length = len;
 678                         req->complete = ep_aio_complete;
 679                         req->context = iocb;
 680                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 681                         if (unlikely(0 != value))
 682                                 usb_ep_free_request(epdata->ep, req);
 683                 } else
 684                         value = -EAGAIN;
 685         } else
 686                 value = -ENODEV;
 687         spin_unlock_irq(&epdata->dev->lock);
 688
 689         up(&epdata->lock);
 690
 691         if (unlikely(value)) {
 692                 kfree(priv);
 693                 put_ep(epdata);
 694         } else
 695                 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
 696         return value;
 697 }
 698
 699 static ssize_t
 700 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
 701                 unsigned long nr_segs, loff_t o)
 702 {
 703         struct ep_data          *epdata = iocb->ki_filp->private_data;
 704         char                    *buf;
 705
 706         if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN))
 707                 return -EINVAL;
 708
 709         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 710         if (unlikely(!buf))
 711                 return -ENOMEM;
 712
 713         iocb->ki_retry = ep_aio_read_retry;
 714         return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
 715 }
 716
 717 static ssize_t
 718 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
 719                 unsigned long nr_segs, loff_t o)
 720 {
 721         struct ep_data          *epdata = iocb->ki_filp->private_data;
 722         char                    *buf;
 723         size_t                  len = 0;
 724         int                     i = 0;
 725
 726         if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN)))
 727                 return -EINVAL;
 728
 729         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 730         if (unlikely(!buf))
 731                 return -ENOMEM;
 732
 733         for (i=0; i < nr_segs; i++) {
 734                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
 735                                 iov[i].iov_len) != 0)) {
 736                         kfree(buf);
 737                         return -EFAULT;
 738                 }
 739                 len += iov[i].iov_len;
 740         }
 741         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
 742 }
 743
 744 /*----------------------------------------------------------------------*/
 745
 746 /* used after endpoint configuration */
 747 static const struct file_operations ep_io_operations = {
 748         .owner =        THIS_MODULE,
 749         .llseek =       no_llseek,
 750
 751         .read =         ep_read,
 752         .write =        ep_write,
 753         .ioctl =        ep_ioctl,
 754         .release =      ep_release,
 755
 756         .aio_read =     ep_aio_read,
 757         .aio_write =    ep_aio_write,
 758 };
 759
 760 /* ENDPOINT INITIALIZATION
 761  *
 762  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 763  *     status = write (fd, descriptors, sizeof descriptors)
 764  *
 765  * That write establishes the endpoint configuration, configuring
 766  * the controller to process bulk, interrupt, or isochronous transfers
 767  * at the right maxpacket size, and so on.
 768  *
 769  * The descriptors are message type 1, identified by a host order u32
 770  * at the beginning of what's written.  Descriptor order is: full/low
 771  * speed descriptor, then optional high speed descriptor.
 772  */
 773 static ssize_t
 774 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 775 {
 776         struct ep_data          *data = fd->private_data;
 777         struct usb_ep           *ep;
 778         u32                     tag;
 779         int                     value, length = len;
 780
 781         if ((value = down_interruptible (&data->lock)) < 0)
 782                 return value;
 783
 784         if (data->state != STATE_EP_READY) {
 785                 value = -EL2HLT;
 786                 goto fail;
 787         }
 788
 789         value = len;
 790         if (len < USB_DT_ENDPOINT_SIZE + 4)
 791                 goto fail0;
 792
 793         /* we might need to change message format someday */
 794         if (copy_from_user (&tag, buf, 4)) {
 795                 goto fail1;
 796         }
 797         if (tag != 1) {
 798                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 799                 goto fail0;
 800         }
 801         buf += 4;
 802         len -= 4;
 803
 804         /* NOTE:  audio endpoint extensions not accepted here;
 805          * just don't include the extra bytes.
 806          */
 807
 808         /* full/low speed descriptor, then high speed */
 809         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 810                 goto fail1;
 811         }
 812         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 813                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 814                 goto fail0;
 815         if (len != USB_DT_ENDPOINT_SIZE) {
 816                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 817                         goto fail0;
 818                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 819                                         USB_DT_ENDPOINT_SIZE)) {
 820                         goto fail1;
 821                 }
 822                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 823                                 || data->hs_desc.bDescriptorType
 824                                         != USB_DT_ENDPOINT) {
 825                         DBG(data->dev, "config %s, bad hs length or type\n",
 826                                         data->name);
 827                         goto fail0;
 828                 }
 829         }
 830
 831         spin_lock_irq (&data->dev->lock);
 832         if (data->dev->state == STATE_DEV_UNBOUND) {
 833                 value = -ENOENT;
 834                 goto gone;
 835         } else if ((ep = data->ep) == NULL) {
 836                 value = -ENODEV;
 837                 goto gone;
 838         }
 839         switch (data->dev->gadget->speed) {
 840         case USB_SPEED_LOW:
 841         case USB_SPEED_FULL:
 842                 value = usb_ep_enable (ep, &data->desc);
 843                 if (value == 0)
 844                         data->state = STATE_EP_ENABLED;
 845                 break;
 846 #ifdef  CONFIG_USB_GADGET_DUALSPEED
 847         case USB_SPEED_HIGH:
 848                 /* fails if caller didn't provide that descriptor... */
 849                 value = usb_ep_enable (ep, &data->hs_desc);
 850                 if (value == 0)
 851                         data->state = STATE_EP_ENABLED;
 852                 break;
 853 #endif
 854         default:
 855                 DBG (data->dev, "unconnected, %s init deferred\n",
 856                                 data->name);
 857                 data->state = STATE_EP_DEFER_ENABLE;
 858         }
 859         if (value == 0) {
 860                 fd->f_op = &ep_io_operations;
 861                 value = length;
 862         }
 863 gone:
 864         spin_unlock_irq (&data->dev->lock);
 865         if (value < 0) {
 866 fail:
 867                 data->desc.bDescriptorType = 0;
 868                 data->hs_desc.bDescriptorType = 0;
 869         }
 870         up (&data->lock);
 871         return value;
 872 fail0:
 873         value = -EINVAL;
 874         goto fail;
 875 fail1:
 876         value = -EFAULT;
 877         goto fail;
 878 }
 879
 880 static int
 881 ep_open (struct inode *inode, struct file *fd)
 882 {
 883         struct ep_data          *data = inode->i_private;
 884         int                     value = -EBUSY;
 885
 886         if (down_interruptible (&data->lock) != 0)
 887                 return -EINTR;
 888         spin_lock_irq (&data->dev->lock);
 889         if (data->dev->state == STATE_DEV_UNBOUND)
 890                 value = -ENOENT;
 891         else if (data->state == STATE_EP_DISABLED) {
 892                 value = 0;
 893                 data->state = STATE_EP_READY;
 894                 get_ep (data);
 895                 fd->private_data = data;
 896                 VDEBUG (data->dev, "%s ready\n", data->name);
 897         } else
 898                 DBG (data->dev, "%s state %d\n",
 899                         data->name, data->state);
 900         spin_unlock_irq (&data->dev->lock);
 901         up (&data->lock);
 902         return value;
 903 }
 904
 905 /* used before endpoint configuration */
 906 static const struct file_operations ep_config_operations = {
 907         .owner =        THIS_MODULE,
 908         .llseek =       no_llseek,
 909
 910         .open =         ep_open,
 911         .write =        ep_config,
 912         .release =      ep_release,
 913 };
 914
 915 /*----------------------------------------------------------------------*/
 916
 917 /* EP0 IMPLEMENTATION can be partly in userspace.
 918  *
 919  * Drivers that use this facility receive various events, including
 920  * control requests the kernel doesn't handle.  Drivers that don't
 921  * use this facility may be too simple-minded for real applications.
 922  */
 923
 924 static inline void ep0_readable (struct dev_data *dev)
 925 {
 926         wake_up (&dev->wait);
 927         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 928 }
 929
 930 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 931 {
 932         struct dev_data         *dev = ep->driver_data;
 933
 934         if (req->buf != dev->rbuf) {
 935                 usb_ep_free_buffer (ep, req->buf, req->dma, req->length);
 936                 req->buf = dev->rbuf;
 937                 req->dma = DMA_ADDR_INVALID;
 938         }
 939         req->complete = epio_complete;
 940         dev->setup_out_ready = 0;
 941 }
 942
 943 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 944 {
 945         struct dev_data         *dev = ep->driver_data;
 946         int                     free = 1;
 947
 948         /* for control OUT, data must still get to userspace */
 949         if (!dev->setup_in) {
 950                 dev->setup_out_error = (req->status != 0);
 951                 if (!dev->setup_out_error)
 952                         free = 0;
 953                 dev->setup_out_ready = 1;
 954                 ep0_readable (dev);
 955         } else if (dev->state == STATE_SETUP)
 956                 dev->state = STATE_CONNECTED;
 957
 958         /* clean up as appropriate */
 959         if (free && req->buf != &dev->rbuf)
 960                 clean_req (ep, req);
 961         req->complete = epio_complete;
 962 }
 963
 964 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 965 {
 966         struct dev_data *dev = ep->driver_data;
 967
 968         if (dev->setup_out_ready) {
 969                 DBG (dev, "ep0 request busy!\n");
 970                 return -EBUSY;
 971         }
 972         if (len > sizeof (dev->rbuf))
 973                 req->buf = usb_ep_alloc_buffer (ep, len, &req->dma, GFP_ATOMIC);
 974         if (req->buf == 0) {
 975                 req->buf = dev->rbuf;
 976                 return -ENOMEM;
 977         }
 978         req->complete = ep0_complete;
 979         req->length = len;
 980         req->zero = 0;
 981         return 0;
 982 }
 983
 984 static ssize_t
 985 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 986 {
 987         struct dev_data                 *dev = fd->private_data;
 988         ssize_t                         retval;
 989         enum ep0_state                  state;
 990
 991         spin_lock_irq (&dev->lock);
 992
 993         /* report fd mode change before acting on it */
 994         if (dev->setup_abort) {
 995                 dev->setup_abort = 0;
 996                 retval = -EIDRM;
 997                 goto done;
 998         }
 999
1000         /* control DATA stage */
1001         if ((state = dev->state) == STATE_SETUP) {
1002
1003                 if (dev->setup_in) {            /* stall IN */
1004                         VDEBUG(dev, "ep0in stall\n");
1005                         (void) usb_ep_set_halt (dev->gadget->ep0);
1006                         retval = -EL2HLT;
1007                         dev->state = STATE_CONNECTED;
1008
1009                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
1010                         struct usb_ep           *ep = dev->gadget->ep0;
1011                         struct usb_request      *req = dev->req;
1012
1013                         if ((retval = setup_req (ep, req, 0)) == 0)
1014                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1015                         dev->state = STATE_CONNECTED;
1016
1017                         /* assume that was SET_CONFIGURATION */
1018                         if (dev->current_config) {
1019                                 unsigned power;
1020 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1021                                 if (dev->gadget->speed == USB_SPEED_HIGH)
1022                                         power = dev->hs_config->bMaxPower;
1023                                 else
1024 #endif
1025                                         power = dev->config->bMaxPower;
1026                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1027                         }
1028
1029                 } else {                        /* collect OUT data */
1030                         if ((fd->f_flags & O_NONBLOCK) != 0
1031                                         && !dev->setup_out_ready) {
1032                                 retval = -EAGAIN;
1033                                 goto done;
1034                         }
1035                         spin_unlock_irq (&dev->lock);
1036                         retval = wait_event_interruptible (dev->wait,
1037                                         dev->setup_out_ready != 0);
1038
1039                         /* FIXME state could change from under us */
1040                         spin_lock_irq (&dev->lock);
1041                         if (retval)
1042                                 goto done;
1043                         if (dev->setup_out_error)
1044                                 retval = -EIO;
1045                         else {
1046                                 len = min (len, (size_t)dev->req->actual);
1047 // FIXME don't call this with the spinlock held ...
1048                                 if (copy_to_user (buf, dev->req->buf, len))
1049                                         retval = -EFAULT;
1050                                 clean_req (dev->gadget->ep0, dev->req);
1051                                 /* NOTE userspace can't yet choose to stall */
1052                         }
1053                 }
1054                 goto done;
1055         }
1056
1057         /* else normal: return event data */
1058         if (len < sizeof dev->event [0]) {
1059                 retval = -EINVAL;
1060                 goto done;
1061         }
1062         len -= len % sizeof (struct usb_gadgetfs_event);
1063         dev->usermode_setup = 1;
1064
1065 scan:
1066         /* return queued events right away */
1067         if (dev->ev_next != 0) {
1068                 unsigned                i, n;
1069                 int                     tmp = dev->ev_next;
1070
1071                 len = min (len, tmp * sizeof (struct usb_gadgetfs_event));
1072                 n = len / sizeof (struct usb_gadgetfs_event);
1073
1074                 /* ep0 can't deliver events when STATE_SETUP */
1075                 for (i = 0; i < n; i++) {
1076                         if (dev->event [i].type == GADGETFS_SETUP) {
1077                                 len = i + 1;
1078                                 len *= sizeof (struct usb_gadgetfs_event);
1079                                 n = 0;
1080                                 break;
1081                         }
1082                 }
1083                 spin_unlock_irq (&dev->lock);
1084                 if (copy_to_user (buf, &dev->event, len))
1085                         retval = -EFAULT;
1086                 else
1087                         retval = len;
1088                 if (len > 0) {
1089                         len /= sizeof (struct usb_gadgetfs_event);
1090
1091                         /* NOTE this doesn't guard against broken drivers;
1092                          * concurrent ep0 readers may lose events.
1093                          */
1094                         spin_lock_irq (&dev->lock);
1095                         dev->ev_next -= len;
1096                         if (dev->ev_next != 0)
1097                                 memmove (&dev->event, &dev->event [len],
1098                                         sizeof (struct usb_gadgetfs_event)
1099                                                 * (tmp - len));
1100                         if (n == 0)
1101                                 dev->state = STATE_SETUP;
1102                         spin_unlock_irq (&dev->lock);
1103                 }
1104                 return retval;
1105         }
1106         if (fd->f_flags & O_NONBLOCK) {
1107                 retval = -EAGAIN;
1108                 goto done;
1109         }
1110
1111         switch (state) {
1112         default:
1113                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, state);
1114                 retval = -ESRCH;
1115                 break;
1116         case STATE_UNCONNECTED:
1117         case STATE_CONNECTED:
1118                 spin_unlock_irq (&dev->lock);
1119                 DBG (dev, "%s wait\n", __FUNCTION__);
1120
1121                 /* wait for events */
1122                 retval = wait_event_interruptible (dev->wait,
1123                                 dev->ev_next != 0);
1124                 if (retval < 0)
1125                         return retval;
1126                 spin_lock_irq (&dev->lock);
1127                 goto scan;
1128         }
1129
1130 done:
1131         spin_unlock_irq (&dev->lock);
1132         return retval;
1133 }
1134
1135 static struct usb_gadgetfs_event *
1136 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1137 {
1138         struct usb_gadgetfs_event       *event;
1139         unsigned                        i;
1140
1141         switch (type) {
1142         /* these events purge the queue */
1143         case GADGETFS_DISCONNECT:
1144                 if (dev->state == STATE_SETUP)
1145                         dev->setup_abort = 1;
1146                 // FALL THROUGH
1147         case GADGETFS_CONNECT:
1148                 dev->ev_next = 0;
1149                 break;
1150         case GADGETFS_SETUP:            /* previous request timed out */
1151         case GADGETFS_SUSPEND:          /* same effect */
1152                 /* these events can't be repeated */
1153                 for (i = 0; i != dev->ev_next; i++) {
1154                         if (dev->event [i].type != type)
1155                                 continue;
1156                         DBG (dev, "discard old event %d\n", type);
1157                         dev->ev_next--;
1158                         if (i == dev->ev_next)
1159                                 break;
1160                         /* indices start at zero, for simplicity */
1161                         memmove (&dev->event [i], &dev->event [i + 1],
1162                                 sizeof (struct usb_gadgetfs_event)
1163                                         * (dev->ev_next - i));
1164                 }
1165                 break;
1166         default:
1167                 BUG ();
1168         }
1169         event = &dev->event [dev->ev_next++];
1170         BUG_ON (dev->ev_next > N_EVENT);
1171         VDEBUG (dev, "ev %d, next %d\n", type, dev->ev_next);
1172         memset (event, 0, sizeof *event);
1173         event->type = type;
1174         return event;
1175 }
1176
1177 static ssize_t
1178 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1179 {
1180         struct dev_data         *dev = fd->private_data;
1181         ssize_t                 retval = -ESRCH;
1182
1183         spin_lock_irq (&dev->lock);
1184
1185         /* report fd mode change before acting on it */
1186         if (dev->setup_abort) {
1187                 dev->setup_abort = 0;
1188                 retval = -EIDRM;
1189
1190         /* data and/or status stage for control request */
1191         } else if (dev->state == STATE_SETUP) {
1192
1193                 /* IN DATA+STATUS caller makes len <= wLength */
1194                 if (dev->setup_in) {
1195                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1196                         if (retval == 0) {
1197                                 spin_unlock_irq (&dev->lock);
1198                                 if (copy_from_user (dev->req->buf, buf, len))
1199                                         retval = -EFAULT;
1200                                 else {
1201                                         if (len < dev->setup_wLength)
1202                                                 dev->req->zero = 1;
1203                                         retval = usb_ep_queue (
1204                                                 dev->gadget->ep0, dev->req,
1205                                                 GFP_KERNEL);
1206                                 }
1207                                 if (retval < 0) {
1208                                         spin_lock_irq (&dev->lock);
1209                                         clean_req (dev->gadget->ep0, dev->req);
1210                                         spin_unlock_irq (&dev->lock);
1211                                 } else
1212                                         retval = len;
1213
1214                                 return retval;
1215                         }
1216
1217                 /* can stall some OUT transfers */
1218                 } else if (dev->setup_can_stall) {
1219                         VDEBUG(dev, "ep0out stall\n");
1220                         (void) usb_ep_set_halt (dev->gadget->ep0);
1221                         retval = -EL2HLT;
1222                         dev->state = STATE_CONNECTED;
1223                 } else {
1224                         DBG(dev, "bogus ep0out stall!\n");
1225                 }
1226         } else
1227                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state);
1228
1229         spin_unlock_irq (&dev->lock);
1230         return retval;
1231 }
1232
1233 static int
1234 ep0_fasync (int f, struct file *fd, int on)
1235 {
1236         struct dev_data         *dev = fd->private_data;
1237         // caller must F_SETOWN before signal delivery happens
1238         VDEBUG (dev, "%s %s\n", __FUNCTION__, on ? "on" : "off");
1239         return fasync_helper (f, fd, on, &dev->fasync);
1240 }
1241
1242 static struct usb_gadget_driver gadgetfs_driver;
1243
1244 static int
1245 dev_release (struct inode *inode, struct file *fd)
1246 {
1247         struct dev_data         *dev = fd->private_data;
1248
1249         /* closing ep0 === shutdown all */
1250
1251         usb_gadget_unregister_driver (&gadgetfs_driver);
1252
1253         /* at this point "good" hardware has disconnected the
1254          * device from USB; the host won't see it any more.
1255          * alternatively, all host requests will time out.
1256          */
1257
1258         fasync_helper (-1, fd, 0, &dev->fasync);
1259         kfree (dev->buf);
1260         dev->buf = NULL;
1261         put_dev (dev);
1262
1263         /* other endpoints were all decoupled from this device */
1264         dev->state = STATE_DEV_DISABLED;
1265         return 0;
1266 }
1267
1268 static unsigned int
1269 ep0_poll (struct file *fd, poll_table *wait)
1270 {
1271        struct dev_data         *dev = fd->private_data;
1272        int                     mask = 0;
1273
1274        poll_wait(fd, &dev->wait, wait);
1275
1276        spin_lock_irq (&dev->lock);
1277
1278        /* report fd mode change before acting on it */
1279        if (dev->setup_abort) {
1280                dev->setup_abort = 0;
1281                mask = POLLHUP;
1282                goto out;
1283        }
1284
1285        if (dev->state == STATE_SETUP) {
1286                if (dev->setup_in || dev->setup_can_stall)
1287                        mask = POLLOUT;
1288        } else {
1289                if (dev->ev_next != 0)
1290                        mask = POLLIN;
1291        }
1292 out:
1293        spin_unlock_irq(&dev->lock);
1294        return mask;
1295 }
1296
1297 static int dev_ioctl (struct inode *inode, struct file *fd,
1298                 unsigned code, unsigned long value)
1299 {
1300         struct dev_data         *dev = fd->private_data;
1301         struct usb_gadget       *gadget = dev->gadget;
1302
1303         if (gadget->ops->ioctl)
1304                 return gadget->ops->ioctl (gadget, code, value);
1305         return -ENOTTY;
1306 }
1307
1308 /* used after device configuration */
1309 static const struct file_operations ep0_io_operations = {
1310         .owner =        THIS_MODULE,
1311         .llseek =       no_llseek,
1312
1313         .read =         ep0_read,
1314         .write =        ep0_write,
1315         .fasync =       ep0_fasync,
1316         .poll =         ep0_poll,
1317         .ioctl =        dev_ioctl,
1318         .release =      dev_release,
1319 };
1320
1321 /*----------------------------------------------------------------------*/
1322
1323 /* The in-kernel gadget driver handles most ep0 issues, in particular
1324  * enumerating the single configuration (as provided from user space).
1325  *
1326  * Unrecognized ep0 requests may be handled in user space.
1327  */
1328
1329 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1330 static void make_qualifier (struct dev_data *dev)
1331 {
1332         struct usb_qualifier_descriptor         qual;
1333         struct usb_device_descriptor            *desc;
1334
1335         qual.bLength = sizeof qual;
1336         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1337         qual.bcdUSB = __constant_cpu_to_le16 (0x0200);
1338
1339         desc = dev->dev;
1340         qual.bDeviceClass = desc->bDeviceClass;
1341         qual.bDeviceSubClass = desc->bDeviceSubClass;
1342         qual.bDeviceProtocol = desc->bDeviceProtocol;
1343
1344         /* assumes ep0 uses the same value for both speeds ... */
1345         qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
1346
1347         qual.bNumConfigurations = 1;
1348         qual.bRESERVED = 0;
1349
1350         memcpy (dev->rbuf, &qual, sizeof qual);
1351 }
1352 #endif
1353
1354 static int
1355 config_buf (struct dev_data *dev, u8 type, unsigned index)
1356 {
1357         int             len;
1358 #ifdef CONFIG_USB_GADGET_DUALSPEED
1359         int             hs;
1360 #endif
1361
1362         /* only one configuration */
1363         if (index > 0)
1364                 return -EINVAL;
1365
1366 #ifdef CONFIG_USB_GADGET_DUALSPEED
1367         hs = (dev->gadget->speed == USB_SPEED_HIGH);
1368         if (type == USB_DT_OTHER_SPEED_CONFIG)
1369                 hs = !hs;
1370         if (hs) {
1371                 dev->req->buf = dev->hs_config;
1372                 len = le16_to_cpup (&dev->hs_config->wTotalLength);
1373         } else
1374 #endif
1375         {
1376                 dev->req->buf = dev->config;
1377                 len = le16_to_cpup (&dev->config->wTotalLength);
1378         }
1379         ((u8 *)dev->req->buf) [1] = type;
1380         return len;
1381 }
1382
1383 static int
1384 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1385 {
1386         struct dev_data                 *dev = get_gadget_data (gadget);
1387         struct usb_request              *req = dev->req;
1388         int                             value = -EOPNOTSUPP;
1389         struct usb_gadgetfs_event       *event;
1390         u16                             w_value = le16_to_cpu(ctrl->wValue);
1391         u16                             w_length = le16_to_cpu(ctrl->wLength);
1392
1393         spin_lock (&dev->lock);
1394         dev->setup_abort = 0;
1395         if (dev->state == STATE_UNCONNECTED) {
1396                 struct usb_ep   *ep;
1397                 struct ep_data  *data;
1398
1399                 dev->state = STATE_CONNECTED;
1400                 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1401
1402 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1403                 if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) {
1404                         ERROR (dev, "no high speed config??\n");
1405                         return -EINVAL;
1406                 }
1407 #endif  /* CONFIG_USB_GADGET_DUALSPEED */
1408
1409                 INFO (dev, "connected\n");
1410                 event = next_event (dev, GADGETFS_CONNECT);
1411                 event->u.speed = gadget->speed;
1412                 ep0_readable (dev);
1413
1414                 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
1415                         data = ep->driver_data;
1416                         /* ... down_trylock (&data->lock) ... */
1417                         if (data->state != STATE_EP_DEFER_ENABLE)
1418                                 continue;
1419 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1420                         if (gadget->speed == USB_SPEED_HIGH)
1421                                 value = usb_ep_enable (ep, &data->hs_desc);
1422                         else
1423 #endif  /* CONFIG_USB_GADGET_DUALSPEED */
1424                                 value = usb_ep_enable (ep, &data->desc);
1425                         if (value) {
1426                                 ERROR (dev, "deferred %s enable --> %d\n",
1427                                         data->name, value);
1428                                 continue;
1429                         }
1430                         data->state = STATE_EP_ENABLED;
1431                         wake_up (&data->wait);
1432                         DBG (dev, "woke up %s waiters\n", data->name);
1433                 }
1434
1435         /* host may have given up waiting for response.  we can miss control
1436          * requests handled lower down (device/endpoint status and features);
1437          * then ep0_{read,write} will report the wrong status. controller
1438          * driver will have aborted pending i/o.
1439          */
1440         } else if (dev->state == STATE_SETUP)
1441                 dev->setup_abort = 1;
1442
1443         req->buf = dev->rbuf;
1444         req->dma = DMA_ADDR_INVALID;
1445         req->context = NULL;
1446         value = -EOPNOTSUPP;
1447         switch (ctrl->bRequest) {
1448
1449         case USB_REQ_GET_DESCRIPTOR:
1450                 if (ctrl->bRequestType != USB_DIR_IN)
1451                         goto unrecognized;
1452                 switch (w_value >> 8) {
1453
1454                 case USB_DT_DEVICE:
1455                         value = min (w_length, (u16) sizeof *dev->dev);
1456                         req->buf = dev->dev;
1457                         break;
1458 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1459                 case USB_DT_DEVICE_QUALIFIER:
1460                         if (!dev->hs_config)
1461                                 break;
1462                         value = min (w_length, (u16)
1463                                 sizeof (struct usb_qualifier_descriptor));
1464                         make_qualifier (dev);
1465                         break;
1466                 case USB_DT_OTHER_SPEED_CONFIG:
1467                         // FALLTHROUGH
1468 #endif
1469                 case USB_DT_CONFIG:
1470                         value = config_buf (dev,
1471                                         w_value >> 8,
1472                                         w_value & 0xff);
1473                         if (value >= 0)
1474                                 value = min (w_length, (u16) value);
1475                         break;
1476                 case USB_DT_STRING:
1477                         goto unrecognized;
1478
1479                 default:                // all others are errors
1480                         break;
1481                 }
1482                 break;
1483
1484         /* currently one config, two speeds */
1485         case USB_REQ_SET_CONFIGURATION:
1486                 if (ctrl->bRequestType != 0)
1487                         break;
1488                 if (0 == (u8) w_value) {
1489                         value = 0;
1490                         dev->current_config = 0;
1491                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1492                         // user mode expected to disable endpoints
1493                 } else {
1494                         u8      config, power;
1495 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1496                         if (gadget->speed == USB_SPEED_HIGH) {
1497                                 config = dev->hs_config->bConfigurationValue;
1498                                 power = dev->hs_config->bMaxPower;
1499                         } else
1500 #endif
1501                         {
1502                                 config = dev->config->bConfigurationValue;
1503                                 power = dev->config->bMaxPower;
1504                         }
1505
1506                         if (config == (u8) w_value) {
1507                                 value = 0;
1508                                 dev->current_config = config;
1509                                 usb_gadget_vbus_draw(gadget, 2 * power);
1510                         }
1511                 }
1512
1513                 /* report SET_CONFIGURATION like any other control request,
1514                  * except that usermode may not stall this.  the next
1515                  * request mustn't be allowed start until this finishes:
1516                  * endpoints and threads set up, etc.
1517                  *
1518                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1519                  * has bad/racey automagic that prevents synchronizing here.
1520                  * even kernel mode drivers often miss them.
1521                  */
1522                 if (value == 0) {
1523                         INFO (dev, "configuration #%d\n", dev->current_config);
1524                         if (dev->usermode_setup) {
1525                                 dev->setup_can_stall = 0;
1526                                 goto delegate;
1527                         }
1528                 }
1529                 break;
1530
1531 #ifndef CONFIG_USB_GADGETFS_PXA2XX
1532         /* PXA automagically handles this request too */
1533         case USB_REQ_GET_CONFIGURATION:
1534                 if (ctrl->bRequestType != 0x80)
1535                         break;
1536                 *(u8 *)req->buf = dev->current_config;
1537                 value = min (w_length, (u16) 1);
1538                 break;
1539 #endif
1540
1541         default:
1542 unrecognized:
1543                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1544                         dev->usermode_setup ? "delegate" : "fail",
1545                         ctrl->bRequestType, ctrl->bRequest,
1546                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1547
1548                 /* if there's an ep0 reader, don't stall */
1549                 if (dev->usermode_setup) {
1550                         dev->setup_can_stall = 1;
1551 delegate:
1552                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1553                                                 ? 1 : 0;
1554                         dev->setup_wLength = w_length;
1555                         dev->setup_out_ready = 0;
1556                         dev->setup_out_error = 0;
1557                         value = 0;
1558
1559                         /* read DATA stage for OUT right away */
1560                         if (unlikely (!dev->setup_in && w_length)) {
1561                                 value = setup_req (gadget->ep0, dev->req,
1562                                                         w_length);
1563                                 if (value < 0)
1564                                         break;
1565                                 value = usb_ep_queue (gadget->ep0, dev->req,
1566                                                         GFP_ATOMIC);
1567                                 if (value < 0) {
1568                                         clean_req (gadget->ep0, dev->req);
1569                                         break;
1570                                 }
1571
1572                                 /* we can't currently stall these */
1573                                 dev->setup_can_stall = 0;
1574                         }
1575
1576                         /* state changes when reader collects event */
1577                         event = next_event (dev, GADGETFS_SETUP);
1578                         event->u.setup = *ctrl;
1579                         ep0_readable (dev);
1580                         spin_unlock (&dev->lock);
1581                         return 0;
1582                 }
1583         }
1584
1585         /* proceed with data transfer and status phases? */
1586         if (value >= 0 && dev->state != STATE_SETUP) {
1587                 req->length = value;
1588                 req->zero = value < w_length;
1589                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1590                 if (value < 0) {
1591                         DBG (dev, "ep_queue --> %d\n", value);
1592                         req->status = 0;
1593                 }
1594         }
1595
1596         /* device stalls when value < 0 */
1597         spin_unlock (&dev->lock);
1598         return value;
1599 }
1600
1601 static void destroy_ep_files (struct dev_data *dev)
1602 {
1603         struct list_head        *entry, *tmp;
1604
1605         DBG (dev, "%s %d\n", __FUNCTION__, dev->state);
1606
1607         /* dev->state must prevent interference */
1608 restart:
1609         spin_lock_irq (&dev->lock);
1610         list_for_each_safe (entry, tmp, &dev->epfiles) {
1611                 struct ep_data  *ep;
1612                 struct inode    *parent;
1613                 struct dentry   *dentry;
1614
1615                 /* break link to FS */
1616                 ep = list_entry (entry, struct ep_data, epfiles);
1617                 list_del_init (&ep->epfiles);
1618                 dentry = ep->dentry;
1619                 ep->dentry = NULL;
1620                 parent = dentry->d_parent->d_inode;
1621
1622                 /* break link to controller */
1623                 if (ep->state == STATE_EP_ENABLED)
1624                         (void) usb_ep_disable (ep->ep);
1625                 ep->state = STATE_EP_UNBOUND;
1626                 usb_ep_free_request (ep->ep, ep->req);
1627                 ep->ep = NULL;
1628                 wake_up (&ep->wait);
1629                 put_ep (ep);
1630
1631                 spin_unlock_irq (&dev->lock);
1632
1633                 /* break link to dcache */
1634                 mutex_lock (&parent->i_mutex);
1635                 d_delete (dentry);
1636                 dput (dentry);
1637                 mutex_unlock (&parent->i_mutex);
1638
1639                 /* fds may still be open */
1640                 goto restart;
1641         }
1642         spin_unlock_irq (&dev->lock);
1643 }
1644
1645
1646 static struct inode *
1647 gadgetfs_create_file (struct super_block *sb, char const *name,
1648                 void *data, const struct file_operations *fops,
1649                 struct dentry **dentry_p);
1650
1651 static int activate_ep_files (struct dev_data *dev)
1652 {
1653         struct usb_ep   *ep;
1654         struct ep_data  *data;
1655
1656         gadget_for_each_ep (ep, dev->gadget) {
1657
1658                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1659                 if (!data)
1660                         goto enomem0;
1661                 data->state = STATE_EP_DISABLED;
1662                 init_MUTEX (&data->lock);
1663                 init_waitqueue_head (&data->wait);
1664
1665                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1666                 atomic_set (&data->count, 1);
1667                 data->dev = dev;
1668                 get_dev (dev);
1669
1670                 data->ep = ep;
1671                 ep->driver_data = data;
1672
1673                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1674                 if (!data->req)
1675                         goto enomem1;
1676
1677                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1678                                 data, &ep_config_operations,
1679                                 &data->dentry);
1680                 if (!data->inode)
1681                         goto enomem2;
1682                 list_add_tail (&data->epfiles, &dev->epfiles);
1683         }
1684         return 0;
1685
1686 enomem2:
1687         usb_ep_free_request (ep, data->req);
1688 enomem1:
1689         put_dev (dev);
1690         kfree (data);
1691 enomem0:
1692         DBG (dev, "%s enomem\n", __FUNCTION__);
1693         destroy_ep_files (dev);
1694         return -ENOMEM;
1695 }
1696
1697 static void
1698 gadgetfs_unbind (struct usb_gadget *gadget)
1699 {
1700         struct dev_data         *dev = get_gadget_data (gadget);
1701
1702         DBG (dev, "%s\n", __FUNCTION__);
1703
1704         spin_lock_irq (&dev->lock);
1705         dev->state = STATE_DEV_UNBOUND;
1706         spin_unlock_irq (&dev->lock);
1707
1708         destroy_ep_files (dev);
1709         gadget->ep0->driver_data = NULL;
1710         set_gadget_data (gadget, NULL);
1711
1712         /* we've already been disconnected ... no i/o is active */
1713         if (dev->req)
1714                 usb_ep_free_request (gadget->ep0, dev->req);
1715         DBG (dev, "%s done\n", __FUNCTION__);
1716         put_dev (dev);
1717 }
1718
1719 static struct dev_data          *the_device;
1720
1721 static int
1722 gadgetfs_bind (struct usb_gadget *gadget)
1723 {
1724         struct dev_data         *dev = the_device;
1725
1726         if (!dev)
1727                 return -ESRCH;
1728         if (0 != strcmp (CHIP, gadget->name)) {
1729                 printk (KERN_ERR "%s expected %s controller not %s\n",
1730                         shortname, CHIP, gadget->name);
1731                 return -ENODEV;
1732         }
1733
1734         set_gadget_data (gadget, dev);
1735         dev->gadget = gadget;
1736         gadget->ep0->driver_data = dev;
1737         dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1738
1739         /* preallocate control response and buffer */
1740         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1741         if (!dev->req)
1742                 goto enomem;
1743         dev->req->context = NULL;
1744         dev->req->complete = epio_complete;
1745
1746         if (activate_ep_files (dev) < 0)
1747                 goto enomem;
1748
1749         INFO (dev, "bound to %s driver\n", gadget->name);
1750         dev->state = STATE_UNCONNECTED;
1751         get_dev (dev);
1752         return 0;
1753
1754 enomem:
1755         gadgetfs_unbind (gadget);
1756         return -ENOMEM;
1757 }
1758
1759 static void
1760 gadgetfs_disconnect (struct usb_gadget *gadget)
1761 {
1762         struct dev_data         *dev = get_gadget_data (gadget);
1763
1764         spin_lock (&dev->lock);
1765         if (dev->state == STATE_UNCONNECTED) {
1766                 DBG (dev, "already unconnected\n");
1767                 goto exit;
1768         }
1769         dev->state = STATE_UNCONNECTED;
1770
1771         INFO (dev, "disconnected\n");
1772         next_event (dev, GADGETFS_DISCONNECT);
1773         ep0_readable (dev);
1774 exit:
1775         spin_unlock (&dev->lock);
1776 }
1777
1778 static void
1779 gadgetfs_suspend (struct usb_gadget *gadget)
1780 {
1781         struct dev_data         *dev = get_gadget_data (gadget);
1782
1783         INFO (dev, "suspended from state %d\n", dev->state);
1784         spin_lock (&dev->lock);
1785         switch (dev->state) {
1786         case STATE_SETUP:               // VERY odd... host died??
1787         case STATE_CONNECTED:
1788         case STATE_UNCONNECTED:
1789                 next_event (dev, GADGETFS_SUSPEND);
1790                 ep0_readable (dev);
1791                 /* FALLTHROUGH */
1792         default:
1793                 break;
1794         }
1795         spin_unlock (&dev->lock);
1796 }
1797
1798 static struct usb_gadget_driver gadgetfs_driver = {
1799 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1800         .speed          = USB_SPEED_HIGH,
1801 #else
1802         .speed          = USB_SPEED_FULL,
1803 #endif
1804         .function       = (char *) driver_desc,
1805         .bind           = gadgetfs_bind,
1806         .unbind         = gadgetfs_unbind,
1807         .setup          = gadgetfs_setup,
1808         .disconnect     = gadgetfs_disconnect,
1809         .suspend        = gadgetfs_suspend,
1810
1811         .driver         = {
1812                 .name           = (char *) shortname,
1813         },
1814 };
1815
1816 /*----------------------------------------------------------------------*/
1817
1818 static void gadgetfs_nop(struct usb_gadget *arg) { }
1819
1820 static int gadgetfs_probe (struct usb_gadget *gadget)
1821 {
1822         CHIP = gadget->name;
1823         return -EISNAM;
1824 }
1825
1826 static struct usb_gadget_driver probe_driver = {
1827         .speed          = USB_SPEED_HIGH,
1828         .bind           = gadgetfs_probe,
1829         .unbind         = gadgetfs_nop,
1830         .setup          = (void *)gadgetfs_nop,
1831         .disconnect     = gadgetfs_nop,
1832         .driver         = {
1833                 .name           = "nop",
1834         },
1835 };
1836
1837
1838 /* DEVICE INITIALIZATION
1839  *
1840  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1841  *     status = write (fd, descriptors, sizeof descriptors)
1842  *
1843  * That write establishes the device configuration, so the kernel can
1844  * bind to the controller ... guaranteeing it can handle enumeration
1845  * at all necessary speeds.  Descriptor order is:
1846  *
1847  * . message tag (u32, host order) ... for now, must be zero; it
1848  *      would change to support features like multi-config devices
1849  * . full/low speed config ... all wTotalLength bytes (with interface,
1850  *      class, altsetting, endpoint, and other descriptors)
1851  * . high speed config ... all descriptors, for high speed operation;
1852  *      this one's optional except for high-speed hardware
1853  * . device descriptor
1854  *
1855  * Endpoints are not yet enabled. Drivers may want to immediately
1856  * initialize them, using the /dev/gadget/ep* files that are available
1857  * as soon as the kernel sees the configuration, or they can wait
1858  * until device configuration and interface altsetting changes create
1859  * the need to configure (or unconfigure) them.
1860  *
1861  * After initialization, the device stays active for as long as that
1862  * $CHIP file is open.  Events may then be read from that descriptor,
1863  * such as configuration notifications.  More complex drivers will handle
1864  * some control requests in user space.
1865  */
1866
1867 static int is_valid_config (struct usb_config_descriptor *config)
1868 {
1869         return config->bDescriptorType == USB_DT_CONFIG
1870                 && config->bLength == USB_DT_CONFIG_SIZE
1871                 && config->bConfigurationValue != 0
1872                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1873                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1874         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1875         /* FIXME check lengths: walk to end */
1876 }
1877
1878 static ssize_t
1879 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1880 {
1881         struct dev_data         *dev = fd->private_data;
1882         ssize_t                 value = len, length = len;
1883         unsigned                total;
1884         u32                     tag;
1885         char                    *kbuf;
1886
1887         if (dev->state != STATE_OPENED)
1888                 return -EEXIST;
1889
1890         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1891                 return -EINVAL;
1892
1893         /* we might need to change message format someday */
1894         if (copy_from_user (&tag, buf, 4))
1895                 return -EFAULT;
1896         if (tag != 0)
1897                 return -EINVAL;
1898         buf += 4;
1899         length -= 4;
1900
1901         kbuf = kmalloc (length, GFP_KERNEL);
1902         if (!kbuf)
1903                 return -ENOMEM;
1904         if (copy_from_user (kbuf, buf, length)) {
1905                 kfree (kbuf);
1906                 return -EFAULT;
1907         }
1908
1909         spin_lock_irq (&dev->lock);
1910         value = -EINVAL;
1911         if (dev->buf)
1912                 goto fail;
1913         dev->buf = kbuf;
1914
1915         /* full or low speed config */
1916         dev->config = (void *) kbuf;
1917         total = le16_to_cpup (&dev->config->wTotalLength);
1918         if (!is_valid_config (dev->config) || total >= length)
1919                 goto fail;
1920         kbuf += total;
1921         length -= total;
1922
1923         /* optional high speed config */
1924         if (kbuf [1] == USB_DT_CONFIG) {
1925                 dev->hs_config = (void *) kbuf;
1926                 total = le16_to_cpup (&dev->hs_config->wTotalLength);
1927                 if (!is_valid_config (dev->hs_config) || total >= length)
1928                         goto fail;
1929                 kbuf += total;
1930                 length -= total;
1931         }
1932
1933         /* could support multiple configs, using another encoding! */
1934
1935         /* device descriptor (tweaked for paranoia) */
1936         if (length != USB_DT_DEVICE_SIZE)
1937                 goto fail;
1938         dev->dev = (void *)kbuf;
1939         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1940                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1941                         || dev->dev->bNumConfigurations != 1)
1942                 goto fail;
1943         dev->dev->bNumConfigurations = 1;
1944         dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200);
1945
1946         /* triggers gadgetfs_bind(); then we can enumerate. */
1947         spin_unlock_irq (&dev->lock);
1948         value = usb_gadget_register_driver (&gadgetfs_driver);
1949         if (value != 0) {
1950                 kfree (dev->buf);
1951                 dev->buf = NULL;
1952         } else {
1953                 /* at this point "good" hardware has for the first time
1954                  * let the USB the host see us.  alternatively, if users
1955                  * unplug/replug that will clear all the error state.
1956                  *
1957                  * note:  everything running before here was guaranteed
1958                  * to choke driver model style diagnostics.  from here
1959                  * on, they can work ... except in cleanup paths that
1960                  * kick in after the ep0 descriptor is closed.
1961                  */
1962                 fd->f_op = &ep0_io_operations;
1963                 value = len;
1964         }
1965         return value;
1966
1967 fail:
1968         spin_unlock_irq (&dev->lock);
1969         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __FUNCTION__, value, dev);
1970         kfree (dev->buf);
1971         dev->buf = NULL;
1972         return value;
1973 }
1974
1975 static int
1976 dev_open (struct inode *inode, struct file *fd)
1977 {
1978         struct dev_data         *dev = inode->i_private;
1979         int                     value = -EBUSY;
1980
1981         if (dev->state == STATE_DEV_DISABLED) {
1982                 dev->ev_next = 0;
1983                 dev->state = STATE_OPENED;
1984                 fd->private_data = dev;
1985                 get_dev (dev);
1986                 value = 0;
1987         }
1988         return value;
1989 }
1990
1991 static const struct file_operations dev_init_operations = {
1992         .owner =        THIS_MODULE,
1993         .llseek =       no_llseek,
1994
1995         .open =         dev_open,
1996         .write =        dev_config,
1997         .fasync =       ep0_fasync,
1998         .ioctl =        dev_ioctl,
1999         .release =      dev_release,
2000 };
2001
2002 /*----------------------------------------------------------------------*/
2003
2004 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
2005  *
2006  * Mounting the filesystem creates a controller file, used first for
2007  * device configuration then later for event monitoring.
2008  */
2009
2010
2011 /* FIXME PAM etc could set this security policy without mount options
2012  * if epfiles inherited ownership and permissons from ep0 ...
2013  */
2014
2015 static unsigned default_uid;
2016 static unsigned default_gid;
2017 static unsigned default_perm = S_IRUSR | S_IWUSR;
2018
2019 module_param (default_uid, uint, 0644);
2020 module_param (default_gid, uint, 0644);
2021 module_param (default_perm, uint, 0644);
2022
2023
2024 static struct inode *
2025 gadgetfs_make_inode (struct super_block *sb,
2026                 void *data, const struct file_operations *fops,
2027                 int mode)
2028 {
2029         struct inode *inode = new_inode (sb);
2030
2031         if (inode) {
2032                 inode->i_mode = mode;
2033                 inode->i_uid = default_uid;
2034                 inode->i_gid = default_gid;
2035                 inode->i_blocks = 0;
2036                 inode->i_atime = inode->i_mtime = inode->i_ctime
2037                                 = CURRENT_TIME;
2038                 inode->i_private = data;
2039                 inode->i_fop = fops;
2040         }
2041         return inode;
2042 }
2043
2044 /* creates in fs root directory, so non-renamable and non-linkable.
2045  * so inode and dentry are paired, until device reconfig.
2046  */
2047 static struct inode *
2048 gadgetfs_create_file (struct super_block *sb, char const *name,
2049                 void *data, const struct file_operations *fops,
2050                 struct dentry **dentry_p)
2051 {
2052         struct dentry   *dentry;
2053         struct inode    *inode;
2054
2055         dentry = d_alloc_name(sb->s_root, name);
2056         if (!dentry)
2057                 return NULL;
2058
2059         inode = gadgetfs_make_inode (sb, data, fops,
2060                         S_IFREG | (default_perm & S_IRWXUGO));
2061         if (!inode) {
2062                 dput(dentry);
2063                 return NULL;
2064         }
2065         d_add (dentry, inode);
2066         *dentry_p = dentry;
2067         return inode;
2068 }
2069
2070 static struct super_operations gadget_fs_operations = {
2071         .statfs =       simple_statfs,
2072         .drop_inode =   generic_delete_inode,
2073 };
2074
2075 static int
2076 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2077 {
2078         struct inode    *inode;
2079         struct dentry   *d;
2080         struct dev_data *dev;
2081
2082         if (the_device)
2083                 return -ESRCH;
2084
2085         /* fake probe to determine $CHIP */
2086         (void) usb_gadget_register_driver (&probe_driver);
2087         if (!CHIP)
2088                 return -ENODEV;
2089
2090         /* superblock */
2091         sb->s_blocksize = PAGE_CACHE_SIZE;
2092         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2093         sb->s_magic = GADGETFS_MAGIC;
2094         sb->s_op = &gadget_fs_operations;
2095         sb->s_time_gran = 1;
2096
2097         /* root inode */
2098         inode = gadgetfs_make_inode (sb,
2099                         NULL, &simple_dir_operations,
2100                         S_IFDIR | S_IRUGO | S_IXUGO);
2101         if (!inode)
2102                 goto enomem0;
2103         inode->i_op = &simple_dir_inode_operations;
2104         if (!(d = d_alloc_root (inode)))
2105                 goto enomem1;
2106         sb->s_root = d;
2107
2108         /* the ep0 file is named after the controller we expect;
2109          * user mode code can use it for sanity checks, like we do.
2110          */
2111         dev = dev_new ();
2112         if (!dev)
2113                 goto enomem2;
2114
2115         dev->sb = sb;
2116         if (!gadgetfs_create_file (sb, CHIP,
2117                                 dev, &dev_init_operations,
2118                                 &dev->dentry))
2119                 goto enomem3;
2120
2121         /* other endpoint files are available after hardware setup,
2122          * from binding to a controller.
2123          */
2124         the_device = dev;
2125         return 0;
2126
2127 enomem3:
2128         put_dev (dev);
2129 enomem2:
2130         dput (d);
2131 enomem1:
2132         iput (inode);
2133 enomem0:
2134         return -ENOMEM;
2135 }
2136
2137 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2138 static int
2139 gadgetfs_get_sb (struct file_system_type *t, int flags,
2140                 const char *path, void *opts, struct vfsmount *mnt)
2141 {
2142         return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt);
2143 }
2144
2145 static void
2146 gadgetfs_kill_sb (struct super_block *sb)
2147 {
2148         kill_litter_super (sb);
2149         if (the_device) {
2150                 put_dev (the_device);
2151                 the_device = NULL;
2152         }
2153 }
2154
2155 /*----------------------------------------------------------------------*/
2156
2157 static struct file_system_type gadgetfs_type = {
2158         .owner          = THIS_MODULE,
2159         .name           = shortname,
2160         .get_sb         = gadgetfs_get_sb,
2161         .kill_sb        = gadgetfs_kill_sb,
2162 };
2163
2164 /*----------------------------------------------------------------------*/
2165
2166 static int __init init (void)
2167 {
2168         int status;
2169
2170         status = register_filesystem (&gadgetfs_type);
2171         if (status == 0)
2172                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2173                         shortname, driver_desc);
2174         return status;
2175 }
2176 module_init (init);
2177
2178 static void __exit cleanup (void)
2179 {
2180         pr_debug ("unregister %s\n", shortname);
2181         unregister_filesystem (&gadgetfs_type);
2182 }
2183 module_exit (cleanup);
2184