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
  13
  14 /* #define VERBOSE_DEBUG */
  15
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/fs.h>
  19 #include <linux/pagemap.h>
  20 #include <linux/uts.h>
  21 #include <linux/wait.h>
  22 #include <linux/compiler.h>
  23 #include <asm/uaccess.h>
  24 #include <linux/sched.h>
  25 #include <linux/slab.h>
  26 #include <linux/poll.h>
  27 #include <linux/delay.h>
  28 #include <linux/device.h>
  29 #include <linux/moduleparam.h>
  30
  31 #include <linux/usb/gadgetfs.h>
  32 #include <linux/usb/gadget.h>
  33
  34
  35 /*
  36  * The gadgetfs API maps each endpoint to a file descriptor so that you
  37  * can use standard synchronous read/write calls for I/O.  There's some
  38  * O_NONBLOCK and O_ASYNC/FASYNC style i/o support.  Example usermode
  39  * drivers show how this works in practice.  You can also use AIO to
  40  * eliminate I/O gaps between requests, to help when streaming data.
  41  *
  42  * Key parts that must be USB-specific are protocols defining how the
  43  * read/write operations relate to the hardware state machines.  There
  44  * are two types of files.  One type is for the device, implementing ep0.
  45  * The other type is for each IN or OUT endpoint.  In both cases, the
  46  * user mode driver must configure the hardware before using it.
  47  *
  48  * - First, dev_config() is called when /dev/gadget/$CHIP is configured
  49  *   (by writing configuration and device descriptors).  Afterwards it
  50  *   may serve as a source of device events, used to handle all control
  51  *   requests other than basic enumeration.
  52  *
  53  * - Then, after a SET_CONFIGURATION control request, ep_config() is
  54  *   called when each /dev/gadget/ep* file is configured (by writing
  55  *   endpoint descriptors).  Afterwards these files are used to write()
  56  *   IN data or to read() OUT data.  To halt the endpoint, a "wrong
  57  *   direction" request is issued (like reading an IN endpoint).
  58  *
  59  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
  60  * not possible on all hardware.  For example, precise fault handling with
  61  * respect to data left in endpoint fifos after aborted operations; or
  62  * selective clearing of endpoint halts, to implement SET_INTERFACE.
  63  */
  64
  65 #define DRIVER_DESC     "USB Gadget filesystem"
  66 #define DRIVER_VERSION  "24 Aug 2004"
  67
  68 static const char driver_desc [] = DRIVER_DESC;
  69 static const char shortname [] = "gadgetfs";
  70
  71 MODULE_DESCRIPTION (DRIVER_DESC);
  72 MODULE_AUTHOR ("David Brownell");
  73 MODULE_LICENSE ("GPL");
  74
  75
  76 /*----------------------------------------------------------------------*/
  77
  78 #define GADGETFS_MAGIC          0xaee71ee7
  79 #define DMA_ADDR_INVALID        (~(dma_addr_t)0)
  80
  81 /* /dev/gadget/$CHIP represents ep0 and the whole device */
  82 enum ep0_state {
  83         /* DISBLED is the initial state.
  84          */
  85         STATE_DEV_DISABLED = 0,
  86
  87         /* Only one open() of /dev/gadget/$CHIP; only one file tracks
  88          * ep0/device i/o modes and binding to the controller.  Driver
  89          * must always write descriptors to initialize the device, then
  90          * the device becomes UNCONNECTED until enumeration.
  91          */
  92         STATE_DEV_OPENED,
  93
  94         /* From then on, ep0 fd is in either of two basic modes:
  95          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
  96          * - SETUP: read/write will transfer control data and succeed;
  97          *   or if "wrong direction", performs protocol stall
  98          */
  99         STATE_DEV_UNCONNECTED,
 100         STATE_DEV_CONNECTED,
 101         STATE_DEV_SETUP,
 102
 103         /* UNBOUND means the driver closed ep0, so the device won't be
 104          * accessible again (DEV_DISABLED) until all fds are closed.
 105          */
 106         STATE_DEV_UNBOUND,
 107 };
 108
 109 /* enough for the whole queue: most events invalidate others */
 110 #define N_EVENT                 5
 111
 112 struct dev_data {
 113         spinlock_t                      lock;
 114         atomic_t                        count;
 115         int                             udc_usage;
 116         enum ep0_state                  state;          /* P: lock */
 117         struct usb_gadgetfs_event       event [N_EVENT];
 118         unsigned                        ev_next;
 119         struct fasync_struct            *fasync;
 120         u8                              current_config;
 121
 122         /* drivers reading ep0 MUST handle control requests (SETUP)
 123          * reported that way; else the host will time out.
 124          */
 125         unsigned                        usermode_setup : 1,
 126                                         setup_in : 1,
 127                                         setup_can_stall : 1,
 128                                         setup_out_ready : 1,
 129                                         setup_out_error : 1,
 130                                         setup_abort : 1;
 131         unsigned                        setup_wLength;
 132
 133         /* the rest is basically write-once */
 134         struct usb_config_descriptor    *config, *hs_config;
 135         struct usb_device_descriptor    *dev;
 136         struct usb_request              *req;
 137         struct usb_gadget               *gadget;
 138         struct list_head                epfiles;
 139         void                            *buf;
 140         wait_queue_head_t               wait;
 141         struct super_block              *sb;
 142         struct dentry                   *dentry;
 143
 144         /* except this scratch i/o buffer for ep0 */
 145         u8                              rbuf [256];
 146 };
 147
 148 static inline void get_dev (struct dev_data *data)
 149 {
 150         atomic_inc (&data->count);
 151 }
 152
 153 static void put_dev (struct dev_data *data)
 154 {
 155         if (likely (!atomic_dec_and_test (&data->count)))
 156                 return;
 157         /* needs no more cleanup */
 158         BUG_ON (waitqueue_active (&data->wait));
 159         kfree (data);
 160 }
 161
 162 static struct dev_data *dev_new (void)
 163 {
 164         struct dev_data         *dev;
 165
 166         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 167         if (!dev)
 168                 return NULL;
 169         dev->state = STATE_DEV_DISABLED;
 170         atomic_set (&dev->count, 1);
 171         spin_lock_init (&dev->lock);
 172         INIT_LIST_HEAD (&dev->epfiles);
 173         init_waitqueue_head (&dev->wait);
 174         return dev;
 175 }
 176
 177 /*----------------------------------------------------------------------*/
 178
 179 /* other /dev/gadget/$ENDPOINT files represent endpoints */
 180 enum ep_state {
 181         STATE_EP_DISABLED = 0,
 182         STATE_EP_READY,
 183         STATE_EP_ENABLED,
 184         STATE_EP_UNBOUND,
 185 };
 186
 187 struct ep_data {
 188         struct mutex                    lock;
 189         enum ep_state                   state;
 190         atomic_t                        count;
 191         struct dev_data                 *dev;
 192         /* must hold dev->lock before accessing ep or req */
 193         struct usb_ep                   *ep;
 194         struct usb_request              *req;
 195         ssize_t                         status;
 196         char                            name [16];
 197         struct usb_endpoint_descriptor  desc, hs_desc;
 198         struct list_head                epfiles;
 199         wait_queue_head_t               wait;
 200         struct dentry                   *dentry;
 201         struct inode                    *inode;
 202 };
 203
 204 static inline void get_ep (struct ep_data *data)
 205 {
 206         atomic_inc (&data->count);
 207 }
 208
 209 static void put_ep (struct ep_data *data)
 210 {
 211         if (likely (!atomic_dec_and_test (&data->count)))
 212                 return;
 213         put_dev (data->dev);
 214         /* needs no more cleanup */
 215         BUG_ON (!list_empty (&data->epfiles));
 216         BUG_ON (waitqueue_active (&data->wait));
 217         kfree (data);
 218 }
 219
 220 /*----------------------------------------------------------------------*/
 221
 222 /* most "how to use the hardware" policy choices are in userspace:
 223  * mapping endpoint roles (which the driver needs) to the capabilities
 224  * which the usb controller has.  most of those capabilities are exposed
 225  * implicitly, starting with the driver name and then endpoint names.
 226  */
 227
 228 static const char *CHIP;
 229
 230 /*----------------------------------------------------------------------*/
 231
 232 /* NOTE:  don't use dev_printk calls before binding to the gadget
 233  * at the end of ep0 configuration, or after unbind.
 234  */
 235
 236 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
 237 #define xprintk(d,level,fmt,args...) \
 238         printk(level "%s: " fmt , shortname , ## args)
 239
 240 #ifdef DEBUG
 241 #define DBG(dev,fmt,args...) \
 242         xprintk(dev , KERN_DEBUG , fmt , ## args)
 243 #else
 244 #define DBG(dev,fmt,args...) \
 245         do { } while (0)
 246 #endif /* DEBUG */
 247
 248 #ifdef VERBOSE_DEBUG
 249 #define VDEBUG  DBG
 250 #else
 251 #define VDEBUG(dev,fmt,args...) \
 252         do { } while (0)
 253 #endif /* DEBUG */
 254
 255 #define ERROR(dev,fmt,args...) \
 256         xprintk(dev , KERN_ERR , fmt , ## args)
 257 #define INFO(dev,fmt,args...) \
 258         xprintk(dev , KERN_INFO , fmt , ## args)
 259
 260
 261 /*----------------------------------------------------------------------*/
 262
 263 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
 264  *
 265  * After opening, configure non-control endpoints.  Then use normal
 266  * stream read() and write() requests; and maybe ioctl() to get more
 267  * precise FIFO status when recovering from cancellation.
 268  */
 269
 270 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
 271 {
 272         struct ep_data  *epdata = ep->driver_data;
 273
 274         if (!req->context)
 275                 return;
 276         if (req->status)
 277                 epdata->status = req->status;
 278         else
 279                 epdata->status = req->actual;
 280         complete ((struct completion *)req->context);
 281 }
 282
 283 /* tasklock endpoint, returning when it's connected.
 284  * still need dev->lock to use epdata->ep.
 285  */
 286 static int
 287 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
 288 {
 289         int     val;
 290
 291         if (f_flags & O_NONBLOCK) {
 292                 if (!mutex_trylock(&epdata->lock))
 293                         goto nonblock;
 294                 if (epdata->state != STATE_EP_ENABLED) {
 295                         mutex_unlock(&epdata->lock);
 296 nonblock:
 297                         val = -EAGAIN;
 298                 } else
 299                         val = 0;
 300                 return val;
 301         }
 302
 303         val = mutex_lock_interruptible(&epdata->lock);
 304         if (val < 0)
 305                 return val;
 306
 307         switch (epdata->state) {
 308         case STATE_EP_ENABLED:
 309                 break;
 310         // case STATE_EP_DISABLED:              /* "can't happen" */
 311         // case STATE_EP_READY:                 /* "can't happen" */
 312         default:                                /* error! */
 313                 pr_debug ("%s: ep %p not available, state %d\n",
 314                                 shortname, epdata, epdata->state);
 315                 // FALLTHROUGH
 316         case STATE_EP_UNBOUND:                  /* clean disconnect */
 317                 val = -ENODEV;
 318                 mutex_unlock(&epdata->lock);
 319         }
 320         return val;
 321 }
 322
 323 static ssize_t
 324 ep_io (struct ep_data *epdata, void *buf, unsigned len)
 325 {
 326         DECLARE_COMPLETION_ONSTACK (done);
 327         int value;
 328
 329         spin_lock_irq (&epdata->dev->lock);
 330         if (likely (epdata->ep != NULL)) {
 331                 struct usb_request      *req = epdata->req;
 332
 333                 req->context = &done;
 334                 req->complete = epio_complete;
 335                 req->buf = buf;
 336                 req->length = len;
 337                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
 338         } else
 339                 value = -ENODEV;
 340         spin_unlock_irq (&epdata->dev->lock);
 341
 342         if (likely (value == 0)) {
 343                 value = wait_event_interruptible (done.wait, done.done);
 344                 if (value != 0) {
 345                         spin_lock_irq (&epdata->dev->lock);
 346                         if (likely (epdata->ep != NULL)) {
 347                                 DBG (epdata->dev, "%s i/o interrupted\n",
 348                                                 epdata->name);
 349                                 usb_ep_dequeue (epdata->ep, epdata->req);
 350                                 spin_unlock_irq (&epdata->dev->lock);
 351
 352                                 wait_event (done.wait, done.done);
 353                                 if (epdata->status == -ECONNRESET)
 354                                         epdata->status = -EINTR;
 355                         } else {
 356                                 spin_unlock_irq (&epdata->dev->lock);
 357
 358                                 DBG (epdata->dev, "endpoint gone\n");
 359                                 epdata->status = -ENODEV;
 360                         }
 361                 }
 362                 return epdata->status;
 363         }
 364         return value;
 365 }
 366
 367
 368 /* handle a synchronous OUT bulk/intr/iso transfer */
 369 static ssize_t
 370 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 371 {
 372         struct ep_data          *data = fd->private_data;
 373         void                    *kbuf;
 374         ssize_t                 value;
 375
 376         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 377                 return value;
 378
 379         /* halt any endpoint by doing a "wrong direction" i/o call */
 380         if (usb_endpoint_dir_in(&data->desc)) {
 381                 if (usb_endpoint_xfer_isoc(&data->desc)) {
 382                         mutex_unlock(&data->lock);
 383                         return -EINVAL;
 384                 }
 385                 DBG (data->dev, "%s halt\n", data->name);
 386                 spin_lock_irq (&data->dev->lock);
 387                 if (likely (data->ep != NULL))
 388                         usb_ep_set_halt (data->ep);
 389                 spin_unlock_irq (&data->dev->lock);
 390                 mutex_unlock(&data->lock);
 391                 return -EBADMSG;
 392         }
 393
 394         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
 395
 396         value = -ENOMEM;
 397         kbuf = kmalloc (len, GFP_KERNEL);
 398         if (unlikely (!kbuf))
 399                 goto free1;
 400
 401         value = ep_io (data, kbuf, len);
 402         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
 403                 data->name, len, (int) value);
 404         if (value >= 0 && copy_to_user (buf, kbuf, value))
 405                 value = -EFAULT;
 406
 407 free1:
 408         mutex_unlock(&data->lock);
 409         kfree (kbuf);
 410         return value;
 411 }
 412
 413 /* handle a synchronous IN bulk/intr/iso transfer */
 414 static ssize_t
 415 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 416 {
 417         struct ep_data          *data = fd->private_data;
 418         void                    *kbuf;
 419         ssize_t                 value;
 420
 421         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
 422                 return value;
 423
 424         /* halt any endpoint by doing a "wrong direction" i/o call */
 425         if (!usb_endpoint_dir_in(&data->desc)) {
 426                 if (usb_endpoint_xfer_isoc(&data->desc)) {
 427                         mutex_unlock(&data->lock);
 428                         return -EINVAL;
 429                 }
 430                 DBG (data->dev, "%s halt\n", data->name);
 431                 spin_lock_irq (&data->dev->lock);
 432                 if (likely (data->ep != NULL))
 433                         usb_ep_set_halt (data->ep);
 434                 spin_unlock_irq (&data->dev->lock);
 435                 mutex_unlock(&data->lock);
 436                 return -EBADMSG;
 437         }
 438
 439         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
 440
 441         value = -ENOMEM;
 442         kbuf = kmalloc (len, GFP_KERNEL);
 443         if (!kbuf)
 444                 goto free1;
 445         if (copy_from_user (kbuf, buf, len)) {
 446                 value = -EFAULT;
 447                 goto free1;
 448         }
 449
 450         value = ep_io (data, kbuf, len);
 451         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
 452                 data->name, len, (int) value);
 453 free1:
 454         mutex_unlock(&data->lock);
 455         kfree (kbuf);
 456         return value;
 457 }
 458
 459 static int
 460 ep_release (struct inode *inode, struct file *fd)
 461 {
 462         struct ep_data          *data = fd->private_data;
 463         int value;
 464
 465         value = mutex_lock_interruptible(&data->lock);
 466         if (value < 0)
 467                 return value;
 468
 469         /* clean up if this can be reopened */
 470         if (data->state != STATE_EP_UNBOUND) {
 471                 data->state = STATE_EP_DISABLED;
 472                 data->desc.bDescriptorType = 0;
 473                 data->hs_desc.bDescriptorType = 0;
 474                 usb_ep_disable(data->ep);
 475         }
 476         mutex_unlock(&data->lock);
 477         put_ep (data);
 478         return 0;
 479 }
 480
 481 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
 482 {
 483         struct ep_data          *data = fd->private_data;
 484         int                     status;
 485
 486         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
 487                 return status;
 488
 489         spin_lock_irq (&data->dev->lock);
 490         if (likely (data->ep != NULL)) {
 491                 switch (code) {
 492                 case GADGETFS_FIFO_STATUS:
 493                         status = usb_ep_fifo_status (data->ep);
 494                         break;
 495                 case GADGETFS_FIFO_FLUSH:
 496                         usb_ep_fifo_flush (data->ep);
 497                         break;
 498                 case GADGETFS_CLEAR_HALT:
 499                         status = usb_ep_clear_halt (data->ep);
 500                         break;
 501                 default:
 502                         status = -ENOTTY;
 503                 }
 504         } else
 505                 status = -ENODEV;
 506         spin_unlock_irq (&data->dev->lock);
 507         mutex_unlock(&data->lock);
 508         return status;
 509 }
 510
 511 /*----------------------------------------------------------------------*/
 512
 513 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
 514
 515 struct kiocb_priv {
 516         struct usb_request      *req;
 517         struct ep_data          *epdata;
 518         void                    *buf;
 519         const struct iovec      *iv;
 520         unsigned long           nr_segs;
 521         unsigned                actual;
 522 };
 523
 524 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
 525 {
 526         struct kiocb_priv       *priv = iocb->private;
 527         struct ep_data          *epdata;
 528         int                     value;
 529
 530         local_irq_disable();
 531         epdata = priv->epdata;
 532         // spin_lock(&epdata->dev->lock);
 533         kiocbSetCancelled(iocb);
 534         if (likely(epdata && epdata->ep && priv->req))
 535                 value = usb_ep_dequeue (epdata->ep, priv->req);
 536         else
 537                 value = -EINVAL;
 538         // spin_unlock(&epdata->dev->lock);
 539         local_irq_enable();
 540
 541         aio_put_req(iocb);
 542         return value;
 543 }
 544
 545 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
 546 {
 547         struct kiocb_priv       *priv = iocb->private;
 548         ssize_t                 len, total;
 549         void                    *to_copy;
 550         int                     i;
 551
 552         /* we "retry" to get the right mm context for this: */
 553
 554         /* copy stuff into user buffers */
 555         total = priv->actual;
 556         len = 0;
 557         to_copy = priv->buf;
 558         for (i=0; i < priv->nr_segs; i++) {
 559                 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
 560
 561                 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
 562                         if (len == 0)
 563                                 len = -EFAULT;
 564                         break;
 565                 }
 566
 567                 total -= this;
 568                 len += this;
 569                 to_copy += this;
 570                 if (total == 0)
 571                         break;
 572         }
 573         kfree(priv->buf);
 574         kfree(priv->iv);
 575         kfree(priv);
 576         return len;
 577 }
 578
 579 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 580 {
 581         struct kiocb            *iocb = req->context;
 582         struct kiocb_priv       *priv = iocb->private;
 583         struct ep_data          *epdata = priv->epdata;
 584
 585         /* lock against disconnect (and ideally, cancel) */
 586         spin_lock(&epdata->dev->lock);
 587         priv->req = NULL;
 588         priv->epdata = NULL;
 589
 590         /* if this was a write or a read returning no data then we
 591          * don't need to copy anything to userspace, so we can
 592          * complete the aio request immediately.
 593          */
 594         if (priv->iv == NULL || unlikely(req->actual == 0)) {
 595                 kfree(req->buf);
 596                 kfree(priv->iv);
 597                 kfree(priv);
 598                 iocb->private = NULL;
 599                 /* aio_complete() reports bytes-transferred _and_ faults */
 600                 aio_complete(iocb, req->actual ? req->actual : req->status,
 601                                 req->status);
 602         } else {
 603                 /* retry() won't report both; so we hide some faults */
 604                 if (unlikely(0 != req->status))
 605                         DBG(epdata->dev, "%s fault %d len %d\n",
 606                                 ep->name, req->status, req->actual);
 607
 608                 priv->buf = req->buf;
 609                 priv->actual = req->actual;
 610                 kick_iocb(iocb);
 611         }
 612
 613         usb_ep_free_request(ep, req);
 614         spin_unlock(&epdata->dev->lock);
 615         put_ep(epdata);
 616 }
 617
 618 static ssize_t
 619 ep_aio_rwtail(
 620         struct kiocb    *iocb,
 621         char            *buf,
 622         size_t          len,
 623         struct ep_data  *epdata,
 624         const struct iovec *iv,
 625         unsigned long   nr_segs
 626 )
 627 {
 628         struct kiocb_priv       *priv;
 629         struct usb_request      *req;
 630         ssize_t                 value;
 631
 632         priv = kzalloc(sizeof *priv, GFP_KERNEL);
 633         if (!priv) {
 634                 value = -ENOMEM;
 635 fail:
 636                 kfree(buf);
 637                 return value;
 638         }
 639         iocb->private = priv;
 640         if (iv) {
 641                 priv->iv = kmemdup(iv, nr_segs * sizeof(struct iovec),
 642                                    GFP_KERNEL);
 643                 if (!priv->iv) {
 644                         value = -ENOMEM;
 645                         kfree(priv);
 646                         goto fail;
 647                 }
 648         }
 649         priv->nr_segs = nr_segs;
 650
 651         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 652         if (unlikely(value < 0)) {
 653                 kfree(priv->iv);
 654                 kfree(priv);
 655                 goto fail;
 656         }
 657
 658         iocb->ki_cancel = ep_aio_cancel;
 659         get_ep(epdata);
 660         priv->epdata = epdata;
 661         priv->actual = 0;
 662
 663         /* each kiocb is coupled to one usb_request, but we can't
 664          * allocate or submit those if the host disconnected.
 665          */
 666         spin_lock_irq(&epdata->dev->lock);
 667         if (likely(epdata->ep)) {
 668                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
 669                 if (likely(req)) {
 670                         priv->req = req;
 671                         req->buf = buf;
 672                         req->length = len;
 673                         req->complete = ep_aio_complete;
 674                         req->context = iocb;
 675                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
 676                         if (unlikely(0 != value))
 677                                 usb_ep_free_request(epdata->ep, req);
 678                 } else
 679                         value = -EAGAIN;
 680         } else
 681                 value = -ENODEV;
 682         spin_unlock_irq(&epdata->dev->lock);
 683
 684         mutex_unlock(&epdata->lock);
 685
 686         if (unlikely(value)) {
 687                 kfree(priv->iv);
 688                 kfree(priv);
 689                 put_ep(epdata);
 690         } else
 691                 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
 692         return value;
 693 }
 694
 695 static ssize_t
 696 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
 697                 unsigned long nr_segs, loff_t o)
 698 {
 699         struct ep_data          *epdata = iocb->ki_filp->private_data;
 700         char                    *buf;
 701
 702         if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
 703                 return -EINVAL;
 704
 705         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 706         if (unlikely(!buf))
 707                 return -ENOMEM;
 708
 709         iocb->ki_retry = ep_aio_read_retry;
 710         return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
 711 }
 712
 713 static ssize_t
 714 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
 715                 unsigned long nr_segs, loff_t o)
 716 {
 717         struct ep_data          *epdata = iocb->ki_filp->private_data;
 718         char                    *buf;
 719         size_t                  len = 0;
 720         int                     i = 0;
 721
 722         if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
 723                 return -EINVAL;
 724
 725         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 726         if (unlikely(!buf))
 727                 return -ENOMEM;
 728
 729         for (i=0; i < nr_segs; i++) {
 730                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
 731                                 iov[i].iov_len) != 0)) {
 732                         kfree(buf);
 733                         return -EFAULT;
 734                 }
 735                 len += iov[i].iov_len;
 736         }
 737         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
 738 }
 739
 740 /*----------------------------------------------------------------------*/
 741
 742 /* used after endpoint configuration */
 743 static const struct file_operations ep_io_operations = {
 744         .owner =        THIS_MODULE,
 745         .llseek =       no_llseek,
 746
 747         .read =         ep_read,
 748         .write =        ep_write,
 749         .unlocked_ioctl = ep_ioctl,
 750         .release =      ep_release,
 751
 752         .aio_read =     ep_aio_read,
 753         .aio_write =    ep_aio_write,
 754 };
 755
 756 /* ENDPOINT INITIALIZATION
 757  *
 758  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
 759  *     status = write (fd, descriptors, sizeof descriptors)
 760  *
 761  * That write establishes the endpoint configuration, configuring
 762  * the controller to process bulk, interrupt, or isochronous transfers
 763  * at the right maxpacket size, and so on.
 764  *
 765  * The descriptors are message type 1, identified by a host order u32
 766  * at the beginning of what's written.  Descriptor order is: full/low
 767  * speed descriptor, then optional high speed descriptor.
 768  */
 769 static ssize_t
 770 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 771 {
 772         struct ep_data          *data = fd->private_data;
 773         struct usb_ep           *ep;
 774         u32                     tag;
 775         int                     value, length = len;
 776
 777         value = mutex_lock_interruptible(&data->lock);
 778         if (value < 0)
 779                 return value;
 780
 781         if (data->state != STATE_EP_READY) {
 782                 value = -EL2HLT;
 783                 goto fail;
 784         }
 785
 786         value = len;
 787         if (len < USB_DT_ENDPOINT_SIZE + 4)
 788                 goto fail0;
 789
 790         /* we might need to change message format someday */
 791         if (copy_from_user (&tag, buf, 4)) {
 792                 goto fail1;
 793         }
 794         if (tag != 1) {
 795                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
 796                 goto fail0;
 797         }
 798         buf += 4;
 799         len -= 4;
 800
 801         /* NOTE:  audio endpoint extensions not accepted here;
 802          * just don't include the extra bytes.
 803          */
 804
 805         /* full/low speed descriptor, then high speed */
 806         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
 807                 goto fail1;
 808         }
 809         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
 810                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
 811                 goto fail0;
 812         if (len != USB_DT_ENDPOINT_SIZE) {
 813                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
 814                         goto fail0;
 815                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
 816                                         USB_DT_ENDPOINT_SIZE)) {
 817                         goto fail1;
 818                 }
 819                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
 820                                 || data->hs_desc.bDescriptorType
 821                                         != USB_DT_ENDPOINT) {
 822                         DBG(data->dev, "config %s, bad hs length or type\n",
 823                                         data->name);
 824                         goto fail0;
 825                 }
 826         }
 827
 828         spin_lock_irq (&data->dev->lock);
 829         if (data->dev->state == STATE_DEV_UNBOUND) {
 830                 value = -ENOENT;
 831                 goto gone;
 832         } else if ((ep = data->ep) == NULL) {
 833                 value = -ENODEV;
 834                 goto gone;
 835         }
 836         switch (data->dev->gadget->speed) {
 837         case USB_SPEED_LOW:
 838         case USB_SPEED_FULL:
 839                 ep->desc = &data->desc;
 840                 value = usb_ep_enable(ep);
 841                 if (value == 0)
 842                         data->state = STATE_EP_ENABLED;
 843                 break;
 844 #ifdef  CONFIG_USB_GADGET_DUALSPEED
 845         case USB_SPEED_HIGH:
 846                 /* fails if caller didn't provide that descriptor... */
 847                 ep->desc = &data->hs_desc;
 848                 value = usb_ep_enable(ep);
 849                 if (value == 0)
 850                         data->state = STATE_EP_ENABLED;
 851                 break;
 852 #endif
 853         default:
 854                 DBG(data->dev, "unconnected, %s init abandoned\n",
 855                                 data->name);
 856                 value = -EINVAL;
 857         }
 858         if (value == 0) {
 859                 fd->f_op = &ep_io_operations;
 860                 value = length;
 861         }
 862 gone:
 863         spin_unlock_irq (&data->dev->lock);
 864         if (value < 0) {
 865 fail:
 866                 data->desc.bDescriptorType = 0;
 867                 data->hs_desc.bDescriptorType = 0;
 868         }
 869         mutex_unlock(&data->lock);
 870         return value;
 871 fail0:
 872         value = -EINVAL;
 873         goto fail;
 874 fail1:
 875         value = -EFAULT;
 876         goto fail;
 877 }
 878
 879 static int
 880 ep_open (struct inode *inode, struct file *fd)
 881 {
 882         struct ep_data          *data = inode->i_private;
 883         int                     value = -EBUSY;
 884
 885         if (mutex_lock_interruptible(&data->lock) != 0)
 886                 return -EINTR;
 887         spin_lock_irq (&data->dev->lock);
 888         if (data->dev->state == STATE_DEV_UNBOUND)
 889                 value = -ENOENT;
 890         else if (data->state == STATE_EP_DISABLED) {
 891                 value = 0;
 892                 data->state = STATE_EP_READY;
 893                 get_ep (data);
 894                 fd->private_data = data;
 895                 VDEBUG (data->dev, "%s ready\n", data->name);
 896         } else
 897                 DBG (data->dev, "%s state %d\n",
 898                         data->name, data->state);
 899         spin_unlock_irq (&data->dev->lock);
 900         mutex_unlock(&data->lock);
 901         return value;
 902 }
 903
 904 /* used before endpoint configuration */
 905 static const struct file_operations ep_config_operations = {
 906         .owner =        THIS_MODULE,
 907         .llseek =       no_llseek,
 908
 909         .open =         ep_open,
 910         .write =        ep_config,
 911         .release =      ep_release,
 912 };
 913
 914 /*----------------------------------------------------------------------*/
 915
 916 /* EP0 IMPLEMENTATION can be partly in userspace.
 917  *
 918  * Drivers that use this facility receive various events, including
 919  * control requests the kernel doesn't handle.  Drivers that don't
 920  * use this facility may be too simple-minded for real applications.
 921  */
 922
 923 static inline void ep0_readable (struct dev_data *dev)
 924 {
 925         wake_up (&dev->wait);
 926         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
 927 }
 928
 929 static void clean_req (struct usb_ep *ep, struct usb_request *req)
 930 {
 931         struct dev_data         *dev = ep->driver_data;
 932
 933         if (req->buf != dev->rbuf) {
 934                 kfree(req->buf);
 935                 req->buf = dev->rbuf;
 936                 req->dma = DMA_ADDR_INVALID;
 937         }
 938         req->complete = epio_complete;
 939         dev->setup_out_ready = 0;
 940 }
 941
 942 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
 943 {
 944         struct dev_data         *dev = ep->driver_data;
 945         unsigned long           flags;
 946         int                     free = 1;
 947
 948         /* for control OUT, data must still get to userspace */
 949         spin_lock_irqsave(&dev->lock, flags);
 950         if (!dev->setup_in) {
 951                 dev->setup_out_error = (req->status != 0);
 952                 if (!dev->setup_out_error)
 953                         free = 0;
 954                 dev->setup_out_ready = 1;
 955                 ep0_readable (dev);
 956         }
 957
 958         /* clean up as appropriate */
 959         if (free && req->buf != &dev->rbuf)
 960                 clean_req (ep, req);
 961         req->complete = epio_complete;
 962         spin_unlock_irqrestore(&dev->lock, flags);
 963 }
 964
 965 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 966 {
 967         struct dev_data *dev = ep->driver_data;
 968
 969         if (dev->setup_out_ready) {
 970                 DBG (dev, "ep0 request busy!\n");
 971                 return -EBUSY;
 972         }
 973         if (len > sizeof (dev->rbuf))
 974                 req->buf = kmalloc(len, GFP_ATOMIC);
 975         if (req->buf == NULL) {
 976                 req->buf = dev->rbuf;
 977                 return -ENOMEM;
 978         }
 979         req->complete = ep0_complete;
 980         req->length = len;
 981         req->zero = 0;
 982         return 0;
 983 }
 984
 985 static ssize_t
 986 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 987 {
 988         struct dev_data                 *dev = fd->private_data;
 989         ssize_t                         retval;
 990         enum ep0_state                  state;
 991
 992         spin_lock_irq (&dev->lock);
 993
 994         /* report fd mode change before acting on it */
 995         if (dev->setup_abort) {
 996                 dev->setup_abort = 0;
 997                 retval = -EIDRM;
 998                 goto done;
 999         }
1000
1001         /* control DATA stage */
1002         if ((state = dev->state) == STATE_DEV_SETUP) {
1003
1004                 if (dev->setup_in) {            /* stall IN */
1005                         VDEBUG(dev, "ep0in stall\n");
1006                         (void) usb_ep_set_halt (dev->gadget->ep0);
1007                         retval = -EL2HLT;
1008                         dev->state = STATE_DEV_CONNECTED;
1009
1010                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
1011                         struct usb_ep           *ep = dev->gadget->ep0;
1012                         struct usb_request      *req = dev->req;
1013
1014                         if ((retval = setup_req (ep, req, 0)) == 0) {
1015                                 ++dev->udc_usage;
1016                                 spin_unlock_irq (&dev->lock);
1017                                 retval = usb_ep_queue (ep, req, GFP_KERNEL);
1018                                 spin_lock_irq (&dev->lock);
1019                                 --dev->udc_usage;
1020                         }
1021                         dev->state = STATE_DEV_CONNECTED;
1022
1023                         /* assume that was SET_CONFIGURATION */
1024                         if (dev->current_config) {
1025                                 unsigned power;
1026
1027                                 if (gadget_is_dualspeed(dev->gadget)
1028                                                 && (dev->gadget->speed
1029                                                         == USB_SPEED_HIGH))
1030                                         power = dev->hs_config->bMaxPower;
1031                                 else
1032                                         power = dev->config->bMaxPower;
1033                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1034                         }
1035
1036                 } else {                        /* collect OUT data */
1037                         if ((fd->f_flags & O_NONBLOCK) != 0
1038                                         && !dev->setup_out_ready) {
1039                                 retval = -EAGAIN;
1040                                 goto done;
1041                         }
1042                         spin_unlock_irq (&dev->lock);
1043                         retval = wait_event_interruptible (dev->wait,
1044                                         dev->setup_out_ready != 0);
1045
1046                         /* FIXME state could change from under us */
1047                         spin_lock_irq (&dev->lock);
1048                         if (retval)
1049                                 goto done;
1050
1051                         if (dev->state != STATE_DEV_SETUP) {
1052                                 retval = -ECANCELED;
1053                                 goto done;
1054                         }
1055                         dev->state = STATE_DEV_CONNECTED;
1056
1057                         if (dev->setup_out_error)
1058                                 retval = -EIO;
1059                         else {
1060                                 len = min (len, (size_t)dev->req->actual);
1061                                 ++dev->udc_usage;
1062                                 spin_unlock_irq(&dev->lock);
1063                                 if (copy_to_user (buf, dev->req->buf, len))
1064                                         retval = -EFAULT;
1065                                 else
1066                                         retval = len;
1067                                 spin_lock_irq(&dev->lock);
1068                                 --dev->udc_usage;
1069                                 clean_req (dev->gadget->ep0, dev->req);
1070                                 /* NOTE userspace can't yet choose to stall */
1071                         }
1072                 }
1073                 goto done;
1074         }
1075
1076         /* else normal: return event data */
1077         if (len < sizeof dev->event [0]) {
1078                 retval = -EINVAL;
1079                 goto done;
1080         }
1081         len -= len % sizeof (struct usb_gadgetfs_event);
1082         dev->usermode_setup = 1;
1083
1084 scan:
1085         /* return queued events right away */
1086         if (dev->ev_next != 0) {
1087                 unsigned                i, n;
1088
1089                 n = len / sizeof (struct usb_gadgetfs_event);
1090                 if (dev->ev_next < n)
1091                         n = dev->ev_next;
1092
1093                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1094                 for (i = 0; i < n; i++) {
1095                         if (dev->event [i].type == GADGETFS_SETUP) {
1096                                 dev->state = STATE_DEV_SETUP;
1097                                 n = i + 1;
1098                                 break;
1099                         }
1100                 }
1101                 spin_unlock_irq (&dev->lock);
1102                 len = n * sizeof (struct usb_gadgetfs_event);
1103                 if (copy_to_user (buf, &dev->event, len))
1104                         retval = -EFAULT;
1105                 else
1106                         retval = len;
1107                 if (len > 0) {
1108                         /* NOTE this doesn't guard against broken drivers;
1109                          * concurrent ep0 readers may lose events.
1110                          */
1111                         spin_lock_irq (&dev->lock);
1112                         if (dev->ev_next > n) {
1113                                 memmove(&dev->event[0], &dev->event[n],
1114                                         sizeof (struct usb_gadgetfs_event)
1115                                                 * (dev->ev_next - n));
1116                         }
1117                         dev->ev_next -= n;
1118                         spin_unlock_irq (&dev->lock);
1119                 }
1120                 return retval;
1121         }
1122         if (fd->f_flags & O_NONBLOCK) {
1123                 retval = -EAGAIN;
1124                 goto done;
1125         }
1126
1127         switch (state) {
1128         default:
1129                 DBG (dev, "fail %s, state %d\n", __func__, state);
1130                 retval = -ESRCH;
1131                 break;
1132         case STATE_DEV_UNCONNECTED:
1133         case STATE_DEV_CONNECTED:
1134                 spin_unlock_irq (&dev->lock);
1135                 DBG (dev, "%s wait\n", __func__);
1136
1137                 /* wait for events */
1138                 retval = wait_event_interruptible (dev->wait,
1139                                 dev->ev_next != 0);
1140                 if (retval < 0)
1141                         return retval;
1142                 spin_lock_irq (&dev->lock);
1143                 goto scan;
1144         }
1145
1146 done:
1147         spin_unlock_irq (&dev->lock);
1148         return retval;
1149 }
1150
1151 static struct usb_gadgetfs_event *
1152 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1153 {
1154         struct usb_gadgetfs_event       *event;
1155         unsigned                        i;
1156
1157         switch (type) {
1158         /* these events purge the queue */
1159         case GADGETFS_DISCONNECT:
1160                 if (dev->state == STATE_DEV_SETUP)
1161                         dev->setup_abort = 1;
1162                 // FALL THROUGH
1163         case GADGETFS_CONNECT:
1164                 dev->ev_next = 0;
1165                 break;
1166         case GADGETFS_SETUP:            /* previous request timed out */
1167         case GADGETFS_SUSPEND:          /* same effect */
1168                 /* these events can't be repeated */
1169                 for (i = 0; i != dev->ev_next; i++) {
1170                         if (dev->event [i].type != type)
1171                                 continue;
1172                         DBG(dev, "discard old event[%d] %d\n", i, type);
1173                         dev->ev_next--;
1174                         if (i == dev->ev_next)
1175                                 break;
1176                         /* indices start at zero, for simplicity */
1177                         memmove (&dev->event [i], &dev->event [i + 1],
1178                                 sizeof (struct usb_gadgetfs_event)
1179                                         * (dev->ev_next - i));
1180                 }
1181                 break;
1182         default:
1183                 BUG ();
1184         }
1185         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1186         event = &dev->event [dev->ev_next++];
1187         BUG_ON (dev->ev_next > N_EVENT);
1188         memset (event, 0, sizeof *event);
1189         event->type = type;
1190         return event;
1191 }
1192
1193 static ssize_t
1194 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1195 {
1196         struct dev_data         *dev = fd->private_data;
1197         ssize_t                 retval = -ESRCH;
1198
1199         spin_lock_irq (&dev->lock);
1200
1201         /* report fd mode change before acting on it */
1202         if (dev->setup_abort) {
1203                 dev->setup_abort = 0;
1204                 retval = -EIDRM;
1205
1206         /* data and/or status stage for control request */
1207         } else if (dev->state == STATE_DEV_SETUP) {
1208
1209                 len = min_t(size_t, len, dev->setup_wLength);
1210                 if (dev->setup_in) {
1211                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1212                         if (retval == 0) {
1213                                 dev->state = STATE_DEV_CONNECTED;
1214                                 ++dev->udc_usage;
1215                                 spin_unlock_irq (&dev->lock);
1216                                 if (copy_from_user (dev->req->buf, buf, len))
1217                                         retval = -EFAULT;
1218                                 else {
1219                                         if (len < dev->setup_wLength)
1220                                                 dev->req->zero = 1;
1221                                         retval = usb_ep_queue (
1222                                                 dev->gadget->ep0, dev->req,
1223                                                 GFP_KERNEL);
1224                                 }
1225                                 spin_lock_irq(&dev->lock);
1226                                 --dev->udc_usage;
1227                                 if (retval < 0) {
1228                                         clean_req (dev->gadget->ep0, dev->req);
1229                                 } else
1230                                         retval = len;
1231                                 spin_unlock_irq(&dev->lock);
1232
1233                                 return retval;
1234                         }
1235
1236                 /* can stall some OUT transfers */
1237                 } else if (dev->setup_can_stall) {
1238                         VDEBUG(dev, "ep0out stall\n");
1239                         (void) usb_ep_set_halt (dev->gadget->ep0);
1240                         retval = -EL2HLT;
1241                         dev->state = STATE_DEV_CONNECTED;
1242                 } else {
1243                         DBG(dev, "bogus ep0out stall!\n");
1244                 }
1245         } else
1246                 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1247
1248         spin_unlock_irq (&dev->lock);
1249         return retval;
1250 }
1251
1252 static int
1253 ep0_fasync (int f, struct file *fd, int on)
1254 {
1255         struct dev_data         *dev = fd->private_data;
1256         // caller must F_SETOWN before signal delivery happens
1257         VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1258         return fasync_helper (f, fd, on, &dev->fasync);
1259 }
1260
1261 static struct usb_gadget_driver gadgetfs_driver;
1262
1263 static int
1264 dev_release (struct inode *inode, struct file *fd)
1265 {
1266         struct dev_data         *dev = fd->private_data;
1267
1268         /* closing ep0 === shutdown all */
1269
1270         usb_gadget_unregister_driver (&gadgetfs_driver);
1271
1272         /* at this point "good" hardware has disconnected the
1273          * device from USB; the host won't see it any more.
1274          * alternatively, all host requests will time out.
1275          */
1276
1277         kfree (dev->buf);
1278         dev->buf = NULL;
1279         put_dev (dev);
1280
1281         /* other endpoints were all decoupled from this device */
1282         spin_lock_irq(&dev->lock);
1283         dev->state = STATE_DEV_DISABLED;
1284         spin_unlock_irq(&dev->lock);
1285         return 0;
1286 }
1287
1288 static unsigned int
1289 ep0_poll (struct file *fd, poll_table *wait)
1290 {
1291        struct dev_data         *dev = fd->private_data;
1292        int                     mask = 0;
1293
1294        poll_wait(fd, &dev->wait, wait);
1295
1296        spin_lock_irq (&dev->lock);
1297
1298        /* report fd mode change before acting on it */
1299        if (dev->setup_abort) {
1300                dev->setup_abort = 0;
1301                mask = POLLHUP;
1302                goto out;
1303        }
1304
1305        if (dev->state == STATE_DEV_SETUP) {
1306                if (dev->setup_in || dev->setup_can_stall)
1307                        mask = POLLOUT;
1308        } else {
1309                if (dev->ev_next != 0)
1310                        mask = POLLIN;
1311        }
1312 out:
1313        spin_unlock_irq(&dev->lock);
1314        return mask;
1315 }
1316
1317 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1318 {
1319         struct dev_data         *dev = fd->private_data;
1320         struct usb_gadget       *gadget = dev->gadget;
1321         long ret = -ENOTTY;
1322
1323         spin_lock_irq(&dev->lock);
1324         if (dev->state == STATE_DEV_OPENED ||
1325                         dev->state == STATE_DEV_UNBOUND) {
1326                 /* Not bound to a UDC */
1327         } else if (gadget->ops->ioctl) {
1328                 ++dev->udc_usage;
1329                 spin_unlock_irq(&dev->lock);
1330
1331                 ret = gadget->ops->ioctl (gadget, code, value);
1332
1333                 spin_lock_irq(&dev->lock);
1334                 --dev->udc_usage;
1335         }
1336         spin_unlock_irq(&dev->lock);
1337
1338         return ret;
1339 }
1340
1341 /* used after device configuration */
1342 static const struct file_operations ep0_io_operations = {
1343         .owner =        THIS_MODULE,
1344         .llseek =       no_llseek,
1345
1346         .read =         ep0_read,
1347         .write =        ep0_write,
1348         .fasync =       ep0_fasync,
1349         .poll =         ep0_poll,
1350         .unlocked_ioctl =       dev_ioctl,
1351         .release =      dev_release,
1352 };
1353
1354 /*----------------------------------------------------------------------*/
1355
1356 /* The in-kernel gadget driver handles most ep0 issues, in particular
1357  * enumerating the single configuration (as provided from user space).
1358  *
1359  * Unrecognized ep0 requests may be handled in user space.
1360  */
1361
1362 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1363 static void make_qualifier (struct dev_data *dev)
1364 {
1365         struct usb_qualifier_descriptor         qual;
1366         struct usb_device_descriptor            *desc;
1367
1368         qual.bLength = sizeof qual;
1369         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1370         qual.bcdUSB = cpu_to_le16 (0x0200);
1371
1372         desc = dev->dev;
1373         qual.bDeviceClass = desc->bDeviceClass;
1374         qual.bDeviceSubClass = desc->bDeviceSubClass;
1375         qual.bDeviceProtocol = desc->bDeviceProtocol;
1376
1377         /* assumes ep0 uses the same value for both speeds ... */
1378         qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1379
1380         qual.bNumConfigurations = 1;
1381         qual.bRESERVED = 0;
1382
1383         memcpy (dev->rbuf, &qual, sizeof qual);
1384 }
1385 #endif
1386
1387 static int
1388 config_buf (struct dev_data *dev, u8 type, unsigned index)
1389 {
1390         int             len;
1391         int             hs = 0;
1392
1393         /* only one configuration */
1394         if (index > 0)
1395                 return -EINVAL;
1396
1397         if (gadget_is_dualspeed(dev->gadget)) {
1398                 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1399                 if (type == USB_DT_OTHER_SPEED_CONFIG)
1400                         hs = !hs;
1401         }
1402         if (hs) {
1403                 dev->req->buf = dev->hs_config;
1404                 len = le16_to_cpu(dev->hs_config->wTotalLength);
1405         } else {
1406                 dev->req->buf = dev->config;
1407                 len = le16_to_cpu(dev->config->wTotalLength);
1408         }
1409         ((u8 *)dev->req->buf) [1] = type;
1410         return len;
1411 }
1412
1413 static int
1414 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1415 {
1416         struct dev_data                 *dev = get_gadget_data (gadget);
1417         struct usb_request              *req = dev->req;
1418         int                             value = -EOPNOTSUPP;
1419         struct usb_gadgetfs_event       *event;
1420         u16                             w_value = le16_to_cpu(ctrl->wValue);
1421         u16                             w_length = le16_to_cpu(ctrl->wLength);
1422
1423         spin_lock (&dev->lock);
1424         dev->setup_abort = 0;
1425         if (dev->state == STATE_DEV_UNCONNECTED) {
1426                 if (gadget_is_dualspeed(gadget)
1427                                 && gadget->speed == USB_SPEED_HIGH
1428                                 && dev->hs_config == NULL) {
1429                         spin_unlock(&dev->lock);
1430                         ERROR (dev, "no high speed config??\n");
1431                         return -EINVAL;
1432                 }
1433
1434                 dev->state = STATE_DEV_CONNECTED;
1435
1436                 INFO (dev, "connected\n");
1437                 event = next_event (dev, GADGETFS_CONNECT);
1438                 event->u.speed = gadget->speed;
1439                 ep0_readable (dev);
1440
1441         /* host may have given up waiting for response.  we can miss control
1442          * requests handled lower down (device/endpoint status and features);
1443          * then ep0_{read,write} will report the wrong status. controller
1444          * driver will have aborted pending i/o.
1445          */
1446         } else if (dev->state == STATE_DEV_SETUP)
1447                 dev->setup_abort = 1;
1448
1449         req->buf = dev->rbuf;
1450         req->dma = DMA_ADDR_INVALID;
1451         req->context = NULL;
1452         value = -EOPNOTSUPP;
1453         switch (ctrl->bRequest) {
1454
1455         case USB_REQ_GET_DESCRIPTOR:
1456                 if (ctrl->bRequestType != USB_DIR_IN)
1457                         goto unrecognized;
1458                 switch (w_value >> 8) {
1459
1460                 case USB_DT_DEVICE:
1461                         value = min (w_length, (u16) sizeof *dev->dev);
1462                         dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1463                         req->buf = dev->dev;
1464                         break;
1465 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1466                 case USB_DT_DEVICE_QUALIFIER:
1467                         if (!dev->hs_config)
1468                                 break;
1469                         value = min (w_length, (u16)
1470                                 sizeof (struct usb_qualifier_descriptor));
1471                         make_qualifier (dev);
1472                         break;
1473                 case USB_DT_OTHER_SPEED_CONFIG:
1474                         // FALLTHROUGH
1475 #endif
1476                 case USB_DT_CONFIG:
1477                         value = config_buf (dev,
1478                                         w_value >> 8,
1479                                         w_value & 0xff);
1480                         if (value >= 0)
1481                                 value = min (w_length, (u16) value);
1482                         break;
1483                 case USB_DT_STRING:
1484                         goto unrecognized;
1485
1486                 default:                // all others are errors
1487                         break;
1488                 }
1489                 break;
1490
1491         /* currently one config, two speeds */
1492         case USB_REQ_SET_CONFIGURATION:
1493                 if (ctrl->bRequestType != 0)
1494                         goto unrecognized;
1495                 if (0 == (u8) w_value) {
1496                         value = 0;
1497                         dev->current_config = 0;
1498                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1499                         // user mode expected to disable endpoints
1500                 } else {
1501                         u8      config, power;
1502
1503                         if (gadget_is_dualspeed(gadget)
1504                                         && gadget->speed == USB_SPEED_HIGH) {
1505                                 config = dev->hs_config->bConfigurationValue;
1506                                 power = dev->hs_config->bMaxPower;
1507                         } else {
1508                                 config = dev->config->bConfigurationValue;
1509                                 power = dev->config->bMaxPower;
1510                         }
1511
1512                         if (config == (u8) w_value) {
1513                                 value = 0;
1514                                 dev->current_config = config;
1515                                 usb_gadget_vbus_draw(gadget, 2 * power);
1516                         }
1517                 }
1518
1519                 /* report SET_CONFIGURATION like any other control request,
1520                  * except that usermode may not stall this.  the next
1521                  * request mustn't be allowed start until this finishes:
1522                  * endpoints and threads set up, etc.
1523                  *
1524                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1525                  * has bad/racey automagic that prevents synchronizing here.
1526                  * even kernel mode drivers often miss them.
1527                  */
1528                 if (value == 0) {
1529                         INFO (dev, "configuration #%d\n", dev->current_config);
1530                         if (dev->usermode_setup) {
1531                                 dev->setup_can_stall = 0;
1532                                 goto delegate;
1533                         }
1534                 }
1535                 break;
1536
1537 #ifndef CONFIG_USB_GADGET_PXA25X
1538         /* PXA automagically handles this request too */
1539         case USB_REQ_GET_CONFIGURATION:
1540                 if (ctrl->bRequestType != 0x80)
1541                         goto unrecognized;
1542                 *(u8 *)req->buf = dev->current_config;
1543                 value = min (w_length, (u16) 1);
1544                 break;
1545 #endif
1546
1547         default:
1548 unrecognized:
1549                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1550                         dev->usermode_setup ? "delegate" : "fail",
1551                         ctrl->bRequestType, ctrl->bRequest,
1552                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1553
1554                 /* if there's an ep0 reader, don't stall */
1555                 if (dev->usermode_setup) {
1556                         dev->setup_can_stall = 1;
1557 delegate:
1558                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1559                                                 ? 1 : 0;
1560                         dev->setup_wLength = w_length;
1561                         dev->setup_out_ready = 0;
1562                         dev->setup_out_error = 0;
1563                         value = 0;
1564
1565                         /* read DATA stage for OUT right away */
1566                         if (unlikely (!dev->setup_in && w_length)) {
1567                                 value = setup_req (gadget->ep0, dev->req,
1568                                                         w_length);
1569                                 if (value < 0)
1570                                         break;
1571
1572                                 ++dev->udc_usage;
1573                                 spin_unlock (&dev->lock);
1574                                 value = usb_ep_queue (gadget->ep0, dev->req,
1575                                                         GFP_KERNEL);
1576                                 spin_lock (&dev->lock);
1577                                 --dev->udc_usage;
1578                                 if (value < 0) {
1579                                         clean_req (gadget->ep0, dev->req);
1580                                         break;
1581                                 }
1582
1583                                 /* we can't currently stall these */
1584                                 dev->setup_can_stall = 0;
1585                         }
1586
1587                         /* state changes when reader collects event */
1588                         event = next_event (dev, GADGETFS_SETUP);
1589                         event->u.setup = *ctrl;
1590                         ep0_readable (dev);
1591                         spin_unlock (&dev->lock);
1592                         return 0;
1593                 }
1594         }
1595
1596         /* proceed with data transfer and status phases? */
1597         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1598                 req->length = value;
1599                 req->zero = value < w_length;
1600
1601                 ++dev->udc_usage;
1602                 spin_unlock (&dev->lock);
1603                 value = usb_ep_queue (gadget->ep0, req, GFP_KERNEL);
1604                 spin_lock(&dev->lock);
1605                 --dev->udc_usage;
1606                 spin_unlock(&dev->lock);
1607                 if (value < 0) {
1608                         DBG (dev, "ep_queue --> %d\n", value);
1609                         req->status = 0;
1610                 }
1611                 return value;
1612         }
1613
1614         /* device stalls when value < 0 */
1615         spin_unlock (&dev->lock);
1616         return value;
1617 }
1618
1619 static void destroy_ep_files (struct dev_data *dev)
1620 {
1621         struct list_head        *entry, *tmp;
1622
1623         DBG (dev, "%s %d\n", __func__, dev->state);
1624
1625         /* dev->state must prevent interference */
1626 restart:
1627         spin_lock_irq (&dev->lock);
1628         list_for_each_safe (entry, tmp, &dev->epfiles) {
1629                 struct ep_data  *ep;
1630                 struct inode    *parent;
1631                 struct dentry   *dentry;
1632
1633                 /* break link to FS */
1634                 ep = list_entry (entry, struct ep_data, epfiles);
1635                 list_del_init (&ep->epfiles);
1636                 spin_unlock_irq (&dev->lock);
1637
1638                 dentry = ep->dentry;
1639                 ep->dentry = NULL;
1640                 parent = dentry->d_parent->d_inode;
1641
1642                 /* break link to controller */
1643                 mutex_lock(&ep->lock);
1644                 if (ep->state == STATE_EP_ENABLED)
1645                         (void) usb_ep_disable (ep->ep);
1646                 ep->state = STATE_EP_UNBOUND;
1647                 usb_ep_free_request (ep->ep, ep->req);
1648                 ep->ep = NULL;
1649                 mutex_unlock(&ep->lock);
1650
1651                 wake_up (&ep->wait);
1652                 put_ep (ep);
1653
1654                 /* break link to dcache */
1655                 mutex_lock (&parent->i_mutex);
1656                 d_delete (dentry);
1657                 dput (dentry);
1658                 mutex_unlock (&parent->i_mutex);
1659
1660                 /* fds may still be open */
1661                 goto restart;
1662         }
1663         spin_unlock_irq (&dev->lock);
1664 }
1665
1666
1667 static struct inode *
1668 gadgetfs_create_file (struct super_block *sb, char const *name,
1669                 void *data, const struct file_operations *fops,
1670                 struct dentry **dentry_p);
1671
1672 static int activate_ep_files (struct dev_data *dev)
1673 {
1674         struct usb_ep   *ep;
1675         struct ep_data  *data;
1676
1677         gadget_for_each_ep (ep, dev->gadget) {
1678
1679                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1680                 if (!data)
1681                         goto enomem0;
1682                 data->state = STATE_EP_DISABLED;
1683                 mutex_init(&data->lock);
1684                 init_waitqueue_head (&data->wait);
1685
1686                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1687                 atomic_set (&data->count, 1);
1688                 data->dev = dev;
1689                 get_dev (dev);
1690
1691                 data->ep = ep;
1692                 ep->driver_data = data;
1693
1694                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1695                 if (!data->req)
1696                         goto enomem1;
1697
1698                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1699                                 data, &ep_config_operations,
1700                                 &data->dentry);
1701                 if (!data->inode)
1702                         goto enomem2;
1703                 list_add_tail (&data->epfiles, &dev->epfiles);
1704         }
1705         return 0;
1706
1707 enomem2:
1708         usb_ep_free_request (ep, data->req);
1709 enomem1:
1710         put_dev (dev);
1711         kfree (data);
1712 enomem0:
1713         DBG (dev, "%s enomem\n", __func__);
1714         destroy_ep_files (dev);
1715         return -ENOMEM;
1716 }
1717
1718 static void
1719 gadgetfs_unbind (struct usb_gadget *gadget)
1720 {
1721         struct dev_data         *dev = get_gadget_data (gadget);
1722
1723         DBG (dev, "%s\n", __func__);
1724
1725         spin_lock_irq (&dev->lock);
1726         dev->state = STATE_DEV_UNBOUND;
1727         while (dev->udc_usage > 0) {
1728                 spin_unlock_irq(&dev->lock);
1729                 usleep_range(1000, 2000);
1730                 spin_lock_irq(&dev->lock);
1731         }
1732         spin_unlock_irq (&dev->lock);
1733
1734         destroy_ep_files (dev);
1735         gadget->ep0->driver_data = NULL;
1736         set_gadget_data (gadget, NULL);
1737
1738         /* we've already been disconnected ... no i/o is active */
1739         if (dev->req)
1740                 usb_ep_free_request (gadget->ep0, dev->req);
1741         DBG (dev, "%s done\n", __func__);
1742         put_dev (dev);
1743 }
1744
1745 static struct dev_data          *the_device;
1746
1747 static int
1748 gadgetfs_bind (struct usb_gadget *gadget)
1749 {
1750         struct dev_data         *dev = the_device;
1751
1752         if (!dev)
1753                 return -ESRCH;
1754         if (0 != strcmp (CHIP, gadget->name)) {
1755                 pr_err("%s expected %s controller not %s\n",
1756                         shortname, CHIP, gadget->name);
1757                 return -ENODEV;
1758         }
1759
1760         set_gadget_data (gadget, dev);
1761         dev->gadget = gadget;
1762         gadget->ep0->driver_data = dev;
1763
1764         /* preallocate control response and buffer */
1765         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1766         if (!dev->req)
1767                 goto enomem;
1768         dev->req->context = NULL;
1769         dev->req->complete = epio_complete;
1770
1771         if (activate_ep_files (dev) < 0)
1772                 goto enomem;
1773
1774         INFO (dev, "bound to %s driver\n", gadget->name);
1775         spin_lock_irq(&dev->lock);
1776         dev->state = STATE_DEV_UNCONNECTED;
1777         spin_unlock_irq(&dev->lock);
1778         get_dev (dev);
1779         return 0;
1780
1781 enomem:
1782         gadgetfs_unbind (gadget);
1783         return -ENOMEM;
1784 }
1785
1786 static void
1787 gadgetfs_disconnect (struct usb_gadget *gadget)
1788 {
1789         struct dev_data         *dev = get_gadget_data (gadget);
1790         unsigned long           flags;
1791
1792         spin_lock_irqsave (&dev->lock, flags);
1793         if (dev->state == STATE_DEV_UNCONNECTED)
1794                 goto exit;
1795         dev->state = STATE_DEV_UNCONNECTED;
1796
1797         INFO (dev, "disconnected\n");
1798         next_event (dev, GADGETFS_DISCONNECT);
1799         ep0_readable (dev);
1800 exit:
1801         spin_unlock_irqrestore (&dev->lock, flags);
1802 }
1803
1804 static void
1805 gadgetfs_suspend (struct usb_gadget *gadget)
1806 {
1807         struct dev_data         *dev = get_gadget_data (gadget);
1808         unsigned long           flags;
1809
1810         INFO (dev, "suspended from state %d\n", dev->state);
1811         spin_lock_irqsave(&dev->lock, flags);
1812         switch (dev->state) {
1813         case STATE_DEV_SETUP:           // VERY odd... host died??
1814         case STATE_DEV_CONNECTED:
1815         case STATE_DEV_UNCONNECTED:
1816                 next_event (dev, GADGETFS_SUSPEND);
1817                 ep0_readable (dev);
1818                 /* FALLTHROUGH */
1819         default:
1820                 break;
1821         }
1822         spin_unlock_irqrestore(&dev->lock, flags);
1823 }
1824
1825 static struct usb_gadget_driver gadgetfs_driver = {
1826 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1827         .speed          = USB_SPEED_HIGH,
1828 #else
1829         .speed          = USB_SPEED_FULL,
1830 #endif
1831         .function       = (char *) driver_desc,
1832         .unbind         = gadgetfs_unbind,
1833         .setup          = gadgetfs_setup,
1834         .disconnect     = gadgetfs_disconnect,
1835         .suspend        = gadgetfs_suspend,
1836
1837         .driver = {
1838                 .name           = (char *) shortname,
1839         },
1840 };
1841
1842 /*----------------------------------------------------------------------*/
1843
1844 static void gadgetfs_nop(struct usb_gadget *arg) { }
1845
1846 static int gadgetfs_probe (struct usb_gadget *gadget)
1847 {
1848         CHIP = gadget->name;
1849         return -EISNAM;
1850 }
1851
1852 static struct usb_gadget_driver probe_driver = {
1853         .speed          = USB_SPEED_HIGH,
1854         .unbind         = gadgetfs_nop,
1855         .setup          = (void *)gadgetfs_nop,
1856         .disconnect     = gadgetfs_nop,
1857         .driver = {
1858                 .name           = "nop",
1859         },
1860 };
1861
1862
1863 /* DEVICE INITIALIZATION
1864  *
1865  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1866  *     status = write (fd, descriptors, sizeof descriptors)
1867  *
1868  * That write establishes the device configuration, so the kernel can
1869  * bind to the controller ... guaranteeing it can handle enumeration
1870  * at all necessary speeds.  Descriptor order is:
1871  *
1872  * . message tag (u32, host order) ... for now, must be zero; it
1873  *      would change to support features like multi-config devices
1874  * . full/low speed config ... all wTotalLength bytes (with interface,
1875  *      class, altsetting, endpoint, and other descriptors)
1876  * . high speed config ... all descriptors, for high speed operation;
1877  *      this one's optional except for high-speed hardware
1878  * . device descriptor
1879  *
1880  * Endpoints are not yet enabled. Drivers must wait until device
1881  * configuration and interface altsetting changes create
1882  * the need to configure (or unconfigure) them.
1883  *
1884  * After initialization, the device stays active for as long as that
1885  * $CHIP file is open.  Events must then be read from that descriptor,
1886  * such as configuration notifications.
1887  */
1888
1889 static int is_valid_config(struct usb_config_descriptor *config,
1890                 unsigned int total)
1891 {
1892         return config->bDescriptorType == USB_DT_CONFIG
1893                 && config->bLength == USB_DT_CONFIG_SIZE
1894                 && total >= USB_DT_CONFIG_SIZE
1895                 && config->bConfigurationValue != 0
1896                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1897                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1898         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1899         /* FIXME check lengths: walk to end */
1900 }
1901
1902 static ssize_t
1903 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1904 {
1905         struct dev_data         *dev = fd->private_data;
1906         ssize_t                 value = len, length = len;
1907         unsigned                total;
1908         u32                     tag;
1909         char                    *kbuf;
1910
1911         if ((len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) ||
1912             (len > PAGE_SIZE * 4))
1913                 return -EINVAL;
1914
1915         /* we might need to change message format someday */
1916         if (copy_from_user (&tag, buf, 4))
1917                 return -EFAULT;
1918         if (tag != 0)
1919                 return -EINVAL;
1920         buf += 4;
1921         length -= 4;
1922
1923         kbuf = memdup_user(buf, length);
1924         if (IS_ERR(kbuf))
1925                 return PTR_ERR(kbuf);
1926
1927         spin_lock_irq (&dev->lock);
1928         value = -EINVAL;
1929         if (dev->buf)
1930                 goto fail;
1931         dev->buf = kbuf;
1932
1933         /* full or low speed config */
1934         dev->config = (void *) kbuf;
1935         total = le16_to_cpu(dev->config->wTotalLength);
1936         if (!is_valid_config(dev->config, total) ||
1937                         total > length - USB_DT_DEVICE_SIZE)
1938                 goto fail;
1939         kbuf += total;
1940         length -= total;
1941
1942         /* optional high speed config */
1943         if (kbuf [1] == USB_DT_CONFIG) {
1944                 dev->hs_config = (void *) kbuf;
1945                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1946                 if (!is_valid_config(dev->hs_config, total) ||
1947                                 total > length - USB_DT_DEVICE_SIZE)
1948                         goto fail;
1949                 kbuf += total;
1950                 length -= total;
1951         } else {
1952                 dev->hs_config = NULL;
1953         }
1954
1955         /* could support multiple configs, using another encoding! */
1956
1957         /* device descriptor (tweaked for paranoia) */
1958         if (length != USB_DT_DEVICE_SIZE)
1959                 goto fail;
1960         dev->dev = (void *)kbuf;
1961         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1962                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1963                         || dev->dev->bNumConfigurations != 1)
1964                 goto fail;
1965         dev->dev->bNumConfigurations = 1;
1966         dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1967
1968         /* triggers gadgetfs_bind(); then we can enumerate. */
1969         spin_unlock_irq (&dev->lock);
1970         value = usb_gadget_probe_driver(&gadgetfs_driver, gadgetfs_bind);
1971         if (value != 0) {
1972                 kfree (dev->buf);
1973                 dev->buf = NULL;
1974         } else {
1975                 /* at this point "good" hardware has for the first time
1976                  * let the USB the host see us.  alternatively, if users
1977                  * unplug/replug that will clear all the error state.
1978                  *
1979                  * note:  everything running before here was guaranteed
1980                  * to choke driver model style diagnostics.  from here
1981                  * on, they can work ... except in cleanup paths that
1982                  * kick in after the ep0 descriptor is closed.
1983                  */
1984                 fd->f_op = &ep0_io_operations;
1985                 value = len;
1986         }
1987         return value;
1988
1989 fail:
1990         spin_unlock_irq (&dev->lock);
1991         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1992         kfree (dev->buf);
1993         dev->buf = NULL;
1994         return value;
1995 }
1996
1997 static int
1998 dev_open (struct inode *inode, struct file *fd)
1999 {
2000         struct dev_data         *dev = inode->i_private;
2001         int                     value = -EBUSY;
2002
2003         spin_lock_irq(&dev->lock);
2004         if (dev->state == STATE_DEV_DISABLED) {
2005                 dev->ev_next = 0;
2006                 dev->state = STATE_DEV_OPENED;
2007                 fd->private_data = dev;
2008                 get_dev (dev);
2009                 value = 0;
2010         }
2011         spin_unlock_irq(&dev->lock);
2012         return value;
2013 }
2014
2015 static const struct file_operations dev_init_operations = {
2016         .owner =        THIS_MODULE,
2017         .llseek =       no_llseek,
2018
2019         .open =         dev_open,
2020         .write =        dev_config,
2021         .fasync =       ep0_fasync,
2022         .unlocked_ioctl = dev_ioctl,
2023         .release =      dev_release,
2024 };
2025
2026 /*----------------------------------------------------------------------*/
2027
2028 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
2029  *
2030  * Mounting the filesystem creates a controller file, used first for
2031  * device configuration then later for event monitoring.
2032  */
2033
2034
2035 /* FIXME PAM etc could set this security policy without mount options
2036  * if epfiles inherited ownership and permissons from ep0 ...
2037  */
2038
2039 static unsigned default_uid;
2040 static unsigned default_gid;
2041 static unsigned default_perm = S_IRUSR | S_IWUSR;
2042
2043 module_param (default_uid, uint, 0644);
2044 module_param (default_gid, uint, 0644);
2045 module_param (default_perm, uint, 0644);
2046
2047
2048 static struct inode *
2049 gadgetfs_make_inode (struct super_block *sb,
2050                 void *data, const struct file_operations *fops,
2051                 int mode)
2052 {
2053         struct inode *inode = new_inode (sb);
2054
2055         if (inode) {
2056                 inode->i_ino = get_next_ino();
2057                 inode->i_mode = mode;
2058                 inode->i_uid = default_uid;
2059                 inode->i_gid = default_gid;
2060                 inode->i_atime = inode->i_mtime = inode->i_ctime
2061                                 = CURRENT_TIME;
2062                 inode->i_private = data;
2063                 inode->i_fop = fops;
2064         }
2065         return inode;
2066 }
2067
2068 /* creates in fs root directory, so non-renamable and non-linkable.
2069  * so inode and dentry are paired, until device reconfig.
2070  */
2071 static struct inode *
2072 gadgetfs_create_file (struct super_block *sb, char const *name,
2073                 void *data, const struct file_operations *fops,
2074                 struct dentry **dentry_p)
2075 {
2076         struct dentry   *dentry;
2077         struct inode    *inode;
2078
2079         dentry = d_alloc_name(sb->s_root, name);
2080         if (!dentry)
2081                 return NULL;
2082
2083         inode = gadgetfs_make_inode (sb, data, fops,
2084                         S_IFREG | (default_perm & S_IRWXUGO));
2085         if (!inode) {
2086                 dput(dentry);
2087                 return NULL;
2088         }
2089         d_add (dentry, inode);
2090         *dentry_p = dentry;
2091         return inode;
2092 }
2093
2094 static const struct super_operations gadget_fs_operations = {
2095         .statfs =       simple_statfs,
2096         .drop_inode =   generic_delete_inode,
2097 };
2098
2099 static int
2100 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2101 {
2102         struct inode    *inode;
2103         struct dentry   *d;
2104         struct dev_data *dev;
2105
2106         if (the_device)
2107                 return -ESRCH;
2108
2109         /* fake probe to determine $CHIP */
2110         (void) usb_gadget_probe_driver(&probe_driver, gadgetfs_probe);
2111         if (!CHIP)
2112                 return -ENODEV;
2113
2114         /* superblock */
2115         sb->s_blocksize = PAGE_CACHE_SIZE;
2116         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2117         sb->s_magic = GADGETFS_MAGIC;
2118         sb->s_op = &gadget_fs_operations;
2119         sb->s_time_gran = 1;
2120
2121         /* root inode */
2122         inode = gadgetfs_make_inode (sb,
2123                         NULL, &simple_dir_operations,
2124                         S_IFDIR | S_IRUGO | S_IXUGO);
2125         if (!inode)
2126                 goto enomem0;
2127         inode->i_op = &simple_dir_inode_operations;
2128         if (!(d = d_alloc_root (inode)))
2129                 goto enomem1;
2130         sb->s_root = d;
2131
2132         /* the ep0 file is named after the controller we expect;
2133          * user mode code can use it for sanity checks, like we do.
2134          */
2135         dev = dev_new ();
2136         if (!dev)
2137                 goto enomem2;
2138
2139         dev->sb = sb;
2140         if (!gadgetfs_create_file (sb, CHIP,
2141                                 dev, &dev_init_operations,
2142                                 &dev->dentry))
2143                 goto enomem3;
2144
2145         /* other endpoint files are available after hardware setup,
2146          * from binding to a controller.
2147          */
2148         the_device = dev;
2149         return 0;
2150
2151 enomem3:
2152         put_dev (dev);
2153 enomem2:
2154         dput (d);
2155 enomem1:
2156         iput (inode);
2157 enomem0:
2158         return -ENOMEM;
2159 }
2160
2161 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2162 static struct dentry *
2163 gadgetfs_mount (struct file_system_type *t, int flags,
2164                 const char *path, void *opts)
2165 {
2166         return mount_single (t, flags, opts, gadgetfs_fill_super);
2167 }
2168
2169 static void
2170 gadgetfs_kill_sb (struct super_block *sb)
2171 {
2172         kill_litter_super (sb);
2173         if (the_device) {
2174                 put_dev (the_device);
2175                 the_device = NULL;
2176         }
2177 }
2178
2179 /*----------------------------------------------------------------------*/
2180
2181 static struct file_system_type gadgetfs_type = {
2182         .owner          = THIS_MODULE,
2183         .name           = shortname,
2184         .mount          = gadgetfs_mount,
2185         .kill_sb        = gadgetfs_kill_sb,
2186 };
2187
2188 /*----------------------------------------------------------------------*/
2189
2190 static int __init init (void)
2191 {
2192         int status;
2193
2194         status = register_filesystem (&gadgetfs_type);
2195         if (status == 0)
2196                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2197                         shortname, driver_desc);
2198         return status;
2199 }
2200 module_init (init);
2201
2202 static void __exit cleanup (void)
2203 {
2204         pr_debug ("unregister %s\n", shortname);
2205         unregister_filesystem (&gadgetfs_type);
2206 }
2207 module_exit (cleanup);
2208