drivers/usb/gadget/f_fs.c

   1 /*
   2  * f_fs.c -- user mode filesystem api for usb composite funtcion controllers
   3  *
   4  * Copyright (C) 2010 Samsung Electronics
   5  * Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
   6  *
   7  * Based on inode.c (GadgetFS):
   8  * Copyright (C) 2003-2004 David Brownell
   9  * Copyright (C) 2003 Agilent Technologies
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  24  */
  25
  26
  27 /* #define DEBUG */
  28 /* #define VERBOSE_DEBUG */
  29
  30 #include <linux/blkdev.h>
  31 #include <asm/unaligned.h>
  32 #include <linux/smp_lock.h>
  33
  34 #include <linux/usb/composite.h>
  35 #include <linux/usb/functionfs.h>
  36
  37
  38 #define FUNCTIONFS_MAGIC        0xa647361 /* Chosen by a honest dice roll ;) */
  39
  40
  41 /* Debuging *****************************************************************/
  42
  43 #define ffs_printk(level, fmt, args...) printk(level "f_fs: " fmt "\n", ## args)
  44
  45 #define FERR(...)  ffs_printk(KERN_ERR,  __VA_ARGS__)
  46 #define FINFO(...) ffs_printk(KERN_INFO, __VA_ARGS__)
  47
  48 #ifdef DEBUG
  49 #  define FDBG(...) ffs_printk(KERN_DEBUG, __VA_ARGS__)
  50 #else
  51 #  define FDBG(...) do { } while (0)
  52 #endif /* DEBUG */
  53
  54 #ifdef VERBOSE_DEBUG
  55 #  define FVDBG FDBG
  56 #else
  57 #  define FVDBG(...) do { } while (0)
  58 #endif /* VERBOSE_DEBUG */
  59
  60 #define ENTER()    FVDBG("%s()", __func__)
  61
  62 #ifdef VERBOSE_DEBUG
  63 #  define ffs_dump_mem(prefix, ptr, len) \
  64         print_hex_dump_bytes("f_fs" prefix ": ", DUMP_PREFIX_NONE, ptr, len)
  65 #else
  66 #  define ffs_dump_mem(prefix, ptr, len) do { } while (0)
  67 #endif
  68
  69
  70 /* The data structure and setup file ****************************************/
  71
  72 enum ffs_state {
  73         /* Waiting for descriptors and strings. */
  74         /* In this state no open(2), read(2) or write(2) on epfiles
  75          * may succeed (which should not be the problem as there
  76          * should be no such files opened in the firts place). */
  77         FFS_READ_DESCRIPTORS,
  78         FFS_READ_STRINGS,
  79
  80         /* We've got descriptors and strings.  We are or have called
  81          * functionfs_ready_callback().  functionfs_bind() may have
  82          * been called but we don't know. */
  83         /* This is the only state in which operations on epfiles may
  84          * succeed. */
  85         FFS_ACTIVE,
  86
  87         /* All endpoints have been closed.  This state is also set if
  88          * we encounter an unrecoverable error.  The only
  89          * unrecoverable error is situation when after reading strings
  90          * from user space we fail to initialise EP files or
  91          * functionfs_ready_callback() returns with error (<0). */
  92         /* In this state no open(2), read(2) or write(2) (both on ep0
  93          * as well as epfile) may succeed (at this point epfiles are
  94          * unlinked and all closed so this is not a problem; ep0 is
  95          * also closed but ep0 file exists and so open(2) on ep0 must
  96          * fail). */
  97         FFS_CLOSING
  98 };
  99
 100
 101 enum ffs_setup_state {
 102         /* There is no setup request pending. */
 103         FFS_NO_SETUP,
 104         /* User has read events and there was a setup request event
 105          * there.  The next read/write on ep0 will handle the
 106          * request. */
 107         FFS_SETUP_PENDING,
 108         /* There was event pending but before user space handled it
 109          * some other event was introduced which canceled existing
 110          * setup.  If this state is set read/write on ep0 return
 111          * -EIDRM.  This state is only set when adding event. */
 112         FFS_SETUP_CANCELED
 113 };
 114
 115
 116
 117 struct ffs_epfile;
 118 struct ffs_function;
 119
 120 struct ffs_data {
 121         struct usb_gadget               *gadget;
 122
 123         /* Protect access read/write operations, only one read/write
 124          * at a time.  As a consequence protects ep0req and company.
 125          * While setup request is being processed (queued) this is
 126          * held. */
 127         struct mutex                    mutex;
 128
 129         /* Protect access to enpoint related structures (basically
 130          * usb_ep_queue(), usb_ep_dequeue(), etc. calls) except for
 131          * endpint zero. */
 132         spinlock_t                      eps_lock;
 133
 134         /* XXX REVISIT do we need our own request? Since we are not
 135          * handling setup requests immidiatelly user space may be so
 136          * slow that another setup will be sent to the gadget but this
 137          * time not to us but another function and then there could be
 138          * a race.  Is taht the case? Or maybe we can use cdev->req
 139          * after all, maybe we just need some spinlock for that? */
 140         struct usb_request              *ep0req;                /* P: mutex */
 141         struct completion               ep0req_completion;      /* P: mutex */
 142         int                             ep0req_status;          /* P: mutex */
 143
 144         /* reference counter */
 145         atomic_t                        ref;
 146         /* how many files are opened (EP0 and others) */
 147         atomic_t                        opened;
 148
 149         /* EP0 state */
 150         enum ffs_state                  state;
 151
 152         /*
 153          * Possible transations:
 154          * + FFS_NO_SETUP       -> FFS_SETUP_PENDING  -- P: ev.waitq.lock
 155          *               happens only in ep0 read which is P: mutex
 156          * + FFS_SETUP_PENDING  -> FFS_NO_SETUP       -- P: ev.waitq.lock
 157          *               happens only in ep0 i/o  which is P: mutex
 158          * + FFS_SETUP_PENDING  -> FFS_SETUP_CANCELED -- P: ev.waitq.lock
 159          * + FFS_SETUP_CANCELED -> FFS_NO_SETUP       -- cmpxchg
 160          */
 161         enum ffs_setup_state            setup_state;
 162
 163 #define FFS_SETUP_STATE(ffs)                                    \
 164         ((enum ffs_setup_state)cmpxchg(&(ffs)->setup_state,     \
 165                                        FFS_SETUP_CANCELED, FFS_NO_SETUP))
 166
 167         /* Events & such. */
 168         struct {
 169                 u8                              types[4];
 170                 unsigned short                  count;
 171                 /* XXX REVISIT need to update it in some places, or do we? */
 172                 unsigned short                  can_stall;
 173                 struct usb_ctrlrequest          setup;
 174
 175                 wait_queue_head_t               waitq;
 176         } ev; /* the whole structure, P: ev.waitq.lock */
 177
 178         /* Flags */
 179         unsigned long                   flags;
 180 #define FFS_FL_CALL_CLOSED_CALLBACK 0
 181 #define FFS_FL_BOUND                1
 182
 183         /* Active function */
 184         struct ffs_function             *func;
 185
 186         /* Device name, write once when file system is mounted.
 187          * Intendet for user to read if she wants. */
 188         const char                      *dev_name;
 189         /* Private data for our user (ie. gadget).  Managed by
 190          * user. */
 191         void                            *private_data;
 192
 193         /* filled by __ffs_data_got_descs() */
 194         /* real descriptors are 16 bytes after raw_descs (so you need
 195          * to skip 16 bytes (ie. ffs->raw_descs + 16) to get to the
 196          * first full speed descriptor).  raw_descs_length and
 197          * raw_fs_descs_length do not have those 16 bytes added. */
 198         const void                      *raw_descs;
 199         unsigned                        raw_descs_length;
 200         unsigned                        raw_fs_descs_length;
 201         unsigned                        fs_descs_count;
 202         unsigned                        hs_descs_count;
 203
 204         unsigned short                  strings_count;
 205         unsigned short                  interfaces_count;
 206         unsigned short                  eps_count;
 207         unsigned short                  _pad1;
 208
 209         /* filled by __ffs_data_got_strings() */
 210         /* ids in stringtabs are set in functionfs_bind() */
 211         const void                      *raw_strings;
 212         struct usb_gadget_strings       **stringtabs;
 213
 214         /* File system's super block, write once when file system is mounted. */
 215         struct super_block              *sb;
 216
 217         /* File permissions, written once when fs is mounted*/
 218         struct ffs_file_perms {
 219                 umode_t                         mode;
 220                 uid_t                           uid;
 221                 gid_t                           gid;
 222         }                               file_perms;
 223
 224         /* The endpoint files, filled by ffs_epfiles_create(),
 225          * destroyed by ffs_epfiles_destroy(). */
 226         struct ffs_epfile               *epfiles;
 227 };
 228
 229 /* Reference counter handling */
 230 static void ffs_data_get(struct ffs_data *ffs);
 231 static void ffs_data_put(struct ffs_data *ffs);
 232 /* Creates new ffs_data object. */
 233 static struct ffs_data *__must_check ffs_data_new(void) __attribute__((malloc));
 234
 235 /* Opened counter handling. */
 236 static void ffs_data_opened(struct ffs_data *ffs);
 237 static void ffs_data_closed(struct ffs_data *ffs);
 238
 239 /* Called with ffs->mutex held; take over ownerrship of data. */
 240 static int __must_check
 241 __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len);
 242 static int __must_check
 243 __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len);
 244
 245
 246 /* The function structure ***************************************************/
 247
 248 struct ffs_ep;
 249
 250 struct ffs_function {
 251         struct usb_configuration        *conf;
 252         struct usb_gadget               *gadget;
 253         struct ffs_data                 *ffs;
 254
 255         struct ffs_ep                   *eps;
 256         u8                              eps_revmap[16];
 257         short                           *interfaces_nums;
 258
 259         struct usb_function             function;
 260 };
 261
 262
 263 static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
 264 {
 265         return container_of(f, struct ffs_function, function);
 266 }
 267
 268 static void ffs_func_free(struct ffs_function *func);
 269
 270
 271 static void ffs_func_eps_disable(struct ffs_function *func);
 272 static int __must_check ffs_func_eps_enable(struct ffs_function *func);
 273
 274
 275 static int ffs_func_bind(struct usb_configuration *,
 276                          struct usb_function *);
 277 static void ffs_func_unbind(struct usb_configuration *,
 278                             struct usb_function *);
 279 static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
 280 static void ffs_func_disable(struct usb_function *);
 281 static int ffs_func_setup(struct usb_function *,
 282                           const struct usb_ctrlrequest *);
 283 static void ffs_func_suspend(struct usb_function *);
 284 static void ffs_func_resume(struct usb_function *);
 285
 286
 287 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num);
 288 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf);
 289
 290
 291
 292 /* The endpoints structures *************************************************/
 293
 294 struct ffs_ep {
 295         struct usb_ep                   *ep;    /* P: ffs->eps_lock */
 296         struct usb_request              *req;   /* P: epfile->mutex */
 297
 298         /* [0]: full speed, [1]: high speed */
 299         struct usb_endpoint_descriptor  *descs[2];
 300
 301         u8                              num;
 302
 303         int                             status; /* P: epfile->mutex */
 304 };
 305
 306 struct ffs_epfile {
 307         /* Protects ep->ep and ep->req. */
 308         struct mutex                    mutex;
 309         wait_queue_head_t               wait;
 310
 311         struct ffs_data                 *ffs;
 312         struct ffs_ep                   *ep;    /* P: ffs->eps_lock */
 313
 314         struct dentry                   *dentry;
 315
 316         char                            name[5];
 317
 318         unsigned char                   in;     /* P: ffs->eps_lock */
 319         unsigned char                   isoc;   /* P: ffs->eps_lock */
 320
 321         unsigned char                   _pad;
 322 };
 323
 324
 325 static int  __must_check ffs_epfiles_create(struct ffs_data *ffs);
 326 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
 327
 328 static struct inode *__must_check
 329 ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
 330                    const struct file_operations *fops,
 331                    struct dentry **dentry_p);
 332
 333
 334 /* Misc helper functions ****************************************************/
 335
 336 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
 337         __attribute__((warn_unused_result, nonnull));
 338 static char *ffs_prepare_buffer(const char * __user buf, size_t len)
 339         __attribute__((warn_unused_result, nonnull));
 340
 341
 342 /* Control file aka ep0 *****************************************************/
 343
 344 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
 345 {
 346         struct ffs_data *ffs = req->context;
 347
 348         complete_all(&ffs->ep0req_completion);
 349 }
 350
 351
 352 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
 353 {
 354         struct usb_request *req = ffs->ep0req;
 355         int ret;
 356
 357         req->zero     = len < le16_to_cpu(ffs->ev.setup.wLength);
 358
 359         spin_unlock_irq(&ffs->ev.waitq.lock);
 360
 361         req->buf      = data;
 362         req->length   = len;
 363
 364         INIT_COMPLETION(ffs->ep0req_completion);
 365
 366         ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
 367         if (unlikely(ret < 0))
 368                 return ret;
 369
 370         ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
 371         if (unlikely(ret)) {
 372                 usb_ep_dequeue(ffs->gadget->ep0, req);
 373                 return -EINTR;
 374         }
 375
 376         ffs->setup_state = FFS_NO_SETUP;
 377         return ffs->ep0req_status;
 378 }
 379
 380 static int __ffs_ep0_stall(struct ffs_data *ffs)
 381 {
 382         if (ffs->ev.can_stall) {
 383                 FVDBG("ep0 stall\n");
 384                 usb_ep_set_halt(ffs->gadget->ep0);
 385                 ffs->setup_state = FFS_NO_SETUP;
 386                 return -EL2HLT;
 387         } else {
 388                 FDBG("bogus ep0 stall!\n");
 389                 return -ESRCH;
 390         }
 391 }
 392
 393
 394 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
 395                              size_t len, loff_t *ptr)
 396 {
 397         struct ffs_data *ffs = file->private_data;
 398         ssize_t ret;
 399         char *data;
 400
 401         ENTER();
 402
 403         /* Fast check if setup was canceled */
 404         if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED)
 405                 return -EIDRM;
 406
 407         /* Acquire mutex */
 408         ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
 409         if (unlikely(ret < 0))
 410                 return ret;
 411
 412
 413         /* Check state */
 414         switch (ffs->state) {
 415         case FFS_READ_DESCRIPTORS:
 416         case FFS_READ_STRINGS:
 417                 /* Copy data */
 418                 if (unlikely(len < 16)) {
 419                         ret = -EINVAL;
 420                         break;
 421                 }
 422
 423                 data = ffs_prepare_buffer(buf, len);
 424                 if (unlikely(IS_ERR(data))) {
 425                         ret = PTR_ERR(data);
 426                         break;
 427                 }
 428
 429                 /* Handle data */
 430                 if (ffs->state == FFS_READ_DESCRIPTORS) {
 431                         FINFO("read descriptors");
 432                         ret = __ffs_data_got_descs(ffs, data, len);
 433                         if (unlikely(ret < 0))
 434                                 break;
 435
 436                         ffs->state = FFS_READ_STRINGS;
 437                         ret = len;
 438                 } else {
 439                         FINFO("read strings");
 440                         ret = __ffs_data_got_strings(ffs, data, len);
 441                         if (unlikely(ret < 0))
 442                                 break;
 443
 444                         ret = ffs_epfiles_create(ffs);
 445                         if (unlikely(ret)) {
 446                                 ffs->state = FFS_CLOSING;
 447                                 break;
 448                         }
 449
 450                         ffs->state = FFS_ACTIVE;
 451                         mutex_unlock(&ffs->mutex);
 452
 453                         ret = functionfs_ready_callback(ffs);
 454                         if (unlikely(ret < 0)) {
 455                                 ffs->state = FFS_CLOSING;
 456                                 return ret;
 457                         }
 458
 459                         set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
 460                         return len;
 461                 }
 462                 break;
 463
 464
 465         case FFS_ACTIVE:
 466                 data = NULL;
 467                 /* We're called from user space, we can use _irq
 468                  * rather then _irqsave */
 469                 spin_lock_irq(&ffs->ev.waitq.lock);
 470                 switch (FFS_SETUP_STATE(ffs)) {
 471                 case FFS_SETUP_CANCELED:
 472                         ret = -EIDRM;
 473                         goto done_spin;
 474
 475                 case FFS_NO_SETUP:
 476                         ret = -ESRCH;
 477                         goto done_spin;
 478
 479                 case FFS_SETUP_PENDING:
 480                         break;
 481                 }
 482
 483                 /* FFS_SETUP_PENDING */
 484                 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
 485                         spin_unlock_irq(&ffs->ev.waitq.lock);
 486                         ret = __ffs_ep0_stall(ffs);
 487                         break;
 488                 }
 489
 490                 /* FFS_SETUP_PENDING and not stall */
 491                 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
 492
 493                 spin_unlock_irq(&ffs->ev.waitq.lock);
 494
 495                 data = ffs_prepare_buffer(buf, len);
 496                 if (unlikely(IS_ERR(data))) {
 497                         ret = PTR_ERR(data);
 498                         break;
 499                 }
 500
 501                 spin_lock_irq(&ffs->ev.waitq.lock);
 502
 503                 /* We are guaranteed to be still in FFS_ACTIVE state
 504                  * but the state of setup could have changed from
 505                  * FFS_SETUP_PENDING to FFS_SETUP_CANCELED so we need
 506                  * to check for that.  If that happened we copied data
 507                  * from user space in vain but it's unlikely. */
 508                 /* For sure we are not in FFS_NO_SETUP since this is
 509                  * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
 510                  * transition can be performed and it's protected by
 511                  * mutex. */
 512
 513                 if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED) {
 514                         ret = -EIDRM;
 515 done_spin:
 516                         spin_unlock_irq(&ffs->ev.waitq.lock);
 517                 } else {
 518                         /* unlocks spinlock */
 519                         ret = __ffs_ep0_queue_wait(ffs, data, len);
 520                 }
 521                 kfree(data);
 522                 break;
 523
 524
 525         default:
 526                 ret = -EBADFD;
 527                 break;
 528         }
 529
 530
 531         mutex_unlock(&ffs->mutex);
 532         return ret;
 533 }
 534
 535
 536
 537 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
 538                                      size_t n)
 539 {
 540         /* We are holding ffs->ev.waitq.lock and ffs->mutex and we need
 541          * to release them. */
 542
 543         struct usb_functionfs_event events[n];
 544         unsigned i = 0;
 545
 546         memset(events, 0, sizeof events);
 547
 548         do {
 549                 events[i].type = ffs->ev.types[i];
 550                 if (events[i].type == FUNCTIONFS_SETUP) {
 551                         events[i].u.setup = ffs->ev.setup;
 552                         ffs->setup_state = FFS_SETUP_PENDING;
 553                 }
 554         } while (++i < n);
 555
 556         if (n < ffs->ev.count) {
 557                 ffs->ev.count -= n;
 558                 memmove(ffs->ev.types, ffs->ev.types + n,
 559                         ffs->ev.count * sizeof *ffs->ev.types);
 560         } else {
 561                 ffs->ev.count = 0;
 562         }
 563
 564         spin_unlock_irq(&ffs->ev.waitq.lock);
 565         mutex_unlock(&ffs->mutex);
 566
 567         return unlikely(__copy_to_user(buf, events, sizeof events))
 568                 ? -EFAULT : sizeof events;
 569 }
 570
 571
 572 static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
 573                             size_t len, loff_t *ptr)
 574 {
 575         struct ffs_data *ffs = file->private_data;
 576         char *data = NULL;
 577         size_t n;
 578         int ret;
 579
 580         ENTER();
 581
 582         /* Fast check if setup was canceled */
 583         if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED)
 584                 return -EIDRM;
 585
 586         /* Acquire mutex */
 587         ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
 588         if (unlikely(ret < 0))
 589                 return ret;
 590
 591
 592         /* Check state */
 593         if (ffs->state != FFS_ACTIVE) {
 594                 ret = -EBADFD;
 595                 goto done_mutex;
 596         }
 597
 598
 599         /* We're called from user space, we can use _irq rather then
 600          * _irqsave */
 601         spin_lock_irq(&ffs->ev.waitq.lock);
 602
 603         switch (FFS_SETUP_STATE(ffs)) {
 604         case FFS_SETUP_CANCELED:
 605                 ret = -EIDRM;
 606                 break;
 607
 608         case FFS_NO_SETUP:
 609                 n = len / sizeof(struct usb_functionfs_event);
 610                 if (unlikely(!n)) {
 611                         ret = -EINVAL;
 612                         break;
 613                 }
 614
 615                 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
 616                         ret = -EAGAIN;
 617                         break;
 618                 }
 619
 620                 if (unlikely(wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq, ffs->ev.count))) {
 621                         ret = -EINTR;
 622                         break;
 623                 }
 624
 625                 return __ffs_ep0_read_events(ffs, buf,
 626                                              min(n, (size_t)ffs->ev.count));
 627
 628
 629         case FFS_SETUP_PENDING:
 630                 if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
 631                         spin_unlock_irq(&ffs->ev.waitq.lock);
 632                         ret = __ffs_ep0_stall(ffs);
 633                         goto done_mutex;
 634                 }
 635
 636                 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
 637
 638                 spin_unlock_irq(&ffs->ev.waitq.lock);
 639
 640                 if (likely(len)) {
 641                         data = kmalloc(len, GFP_KERNEL);
 642                         if (unlikely(!data)) {
 643                                 ret = -ENOMEM;
 644                                 goto done_mutex;
 645                         }
 646                 }
 647
 648                 spin_lock_irq(&ffs->ev.waitq.lock);
 649
 650                 /* See ffs_ep0_write() */
 651                 if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED) {
 652                         ret = -EIDRM;
 653                         break;
 654                 }
 655
 656                 /* unlocks spinlock */
 657                 ret = __ffs_ep0_queue_wait(ffs, data, len);
 658                 if (likely(ret > 0) && unlikely(__copy_to_user(buf, data, len)))
 659                         ret = -EFAULT;
 660                 goto done_mutex;
 661
 662         default:
 663                 ret = -EBADFD;
 664                 break;
 665         }
 666
 667         spin_unlock_irq(&ffs->ev.waitq.lock);
 668 done_mutex:
 669         mutex_unlock(&ffs->mutex);
 670         kfree(data);
 671         return ret;
 672 }
 673
 674
 675
 676 static int ffs_ep0_open(struct inode *inode, struct file *file)
 677 {
 678         struct ffs_data *ffs = inode->i_private;
 679
 680         ENTER();
 681
 682         if (unlikely(ffs->state == FFS_CLOSING))
 683                 return -EBUSY;
 684
 685         file->private_data = ffs;
 686         ffs_data_opened(ffs);
 687
 688         return 0;
 689 }
 690
 691
 692 static int ffs_ep0_release(struct inode *inode, struct file *file)
 693 {
 694         struct ffs_data *ffs = file->private_data;
 695
 696         ENTER();
 697
 698         ffs_data_closed(ffs);
 699
 700         return 0;
 701 }
 702
 703
 704 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value)
 705 {
 706         struct ffs_data *ffs = file->private_data;
 707         struct usb_gadget *gadget = ffs->gadget;
 708         long ret;
 709
 710         ENTER();
 711
 712         if (code == FUNCTIONFS_INTERFACE_REVMAP) {
 713                 struct ffs_function *func = ffs->func;
 714                 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV;
 715         } else if (gadget->ops->ioctl) {
 716                 lock_kernel();
 717                 ret = gadget->ops->ioctl(gadget, code, value);
 718                 unlock_kernel();
 719         } else {
 720                 ret = -ENOTTY;
 721         }
 722
 723         return ret;
 724 }
 725
 726
 727 static const struct file_operations ffs_ep0_operations = {
 728         .owner =        THIS_MODULE,
 729         .llseek =       no_llseek,
 730
 731         .open =         ffs_ep0_open,
 732         .write =        ffs_ep0_write,
 733         .read =         ffs_ep0_read,
 734         .release =      ffs_ep0_release,
 735         .unlocked_ioctl =       ffs_ep0_ioctl,
 736 };
 737
 738
 739 /* "Normal" endpoints operations ********************************************/
 740
 741
 742 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
 743 {
 744         ENTER();
 745         if (likely(req->context)) {
 746                 struct ffs_ep *ep = _ep->driver_data;
 747                 ep->status = req->status ? req->status : req->actual;
 748                 complete(req->context);
 749         }
 750 }
 751
 752
 753 static ssize_t ffs_epfile_io(struct file *file,
 754                              char __user *buf, size_t len, int read)
 755 {
 756         struct ffs_epfile *epfile = file->private_data;
 757         struct ffs_ep *ep;
 758         char *data = NULL;
 759         ssize_t ret;
 760         int halt;
 761
 762         goto first_try;
 763         do {
 764                 spin_unlock_irq(&epfile->ffs->eps_lock);
 765                 mutex_unlock(&epfile->mutex);
 766
 767 first_try:
 768                 /* Are we still active? */
 769                 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) {
 770                         ret = -ENODEV;
 771                         goto error;
 772                 }
 773
 774                 /* Wait for endpoint to be enabled */
 775                 ep = epfile->ep;
 776                 if (!ep) {
 777                         if (file->f_flags & O_NONBLOCK) {
 778                                 ret = -EAGAIN;
 779                                 goto error;
 780                         }
 781
 782                         if (unlikely(wait_event_interruptible
 783                                      (epfile->wait, (ep = epfile->ep)))) {
 784                                 ret = -EINTR;
 785                                 goto error;
 786                         }
 787                 }
 788
 789                 /* Do we halt? */
 790                 halt = !read == !epfile->in;
 791                 if (halt && epfile->isoc) {
 792                         ret = -EINVAL;
 793                         goto error;
 794                 }
 795
 796                 /* Allocate & copy */
 797                 if (!halt && !data) {
 798                         data = kzalloc(len, GFP_KERNEL);
 799                         if (unlikely(!data))
 800                                 return -ENOMEM;
 801
 802                         if (!read &&
 803                             unlikely(__copy_from_user(data, buf, len))) {
 804                                 ret = -EFAULT;
 805                                 goto error;
 806                         }
 807                 }
 808
 809                 /* We will be using request */
 810                 ret = ffs_mutex_lock(&epfile->mutex,
 811                                      file->f_flags & O_NONBLOCK);
 812                 if (unlikely(ret))
 813                         goto error;
 814
 815                 /* We're called from user space, we can use _irq rather then
 816                  * _irqsave */
 817                 spin_lock_irq(&epfile->ffs->eps_lock);
 818
 819                 /* While we were acquiring mutex endpoint got disabled
 820                  * or changed? */
 821         } while (unlikely(epfile->ep != ep));
 822
 823         /* Halt */
 824         if (unlikely(halt)) {
 825                 if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
 826                         usb_ep_set_halt(ep->ep);
 827                 spin_unlock_irq(&epfile->ffs->eps_lock);
 828                 ret = -EBADMSG;
 829         } else {
 830                 /* Fire the request */
 831                 DECLARE_COMPLETION_ONSTACK(done);
 832
 833                 struct usb_request *req = ep->req;
 834                 req->context  = &done;
 835                 req->complete = ffs_epfile_io_complete;
 836                 req->buf      = data;
 837                 req->length   = len;
 838
 839                 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
 840
 841                 spin_unlock_irq(&epfile->ffs->eps_lock);
 842
 843                 if (unlikely(ret < 0)) {
 844                         /* nop */
 845                 } else if (unlikely(wait_for_completion_interruptible(&done))) {
 846                         ret = -EINTR;
 847                         usb_ep_dequeue(ep->ep, req);
 848                 } else {
 849                         ret = ep->status;
 850                         if (read && ret > 0 &&
 851                             unlikely(copy_to_user(buf, data, ret)))
 852                                 ret = -EFAULT;
 853                 }
 854         }
 855
 856         mutex_unlock(&epfile->mutex);
 857 error:
 858         kfree(data);
 859         return ret;
 860 }
 861
 862
 863 static ssize_t
 864 ffs_epfile_write(struct file *file, const char __user *buf, size_t len,
 865                  loff_t *ptr)
 866 {
 867         ENTER();
 868
 869         return ffs_epfile_io(file, (char __user *)buf, len, 0);
 870 }
 871
 872 static ssize_t
 873 ffs_epfile_read(struct file *file, char __user *buf, size_t len, loff_t *ptr)
 874 {
 875         ENTER();
 876
 877         return ffs_epfile_io(file, buf, len, 1);
 878 }
 879
 880 static int
 881 ffs_epfile_open(struct inode *inode, struct file *file)
 882 {
 883         struct ffs_epfile *epfile = inode->i_private;
 884
 885         ENTER();
 886
 887         if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
 888                 return -ENODEV;
 889
 890         file->private_data = epfile;
 891         ffs_data_opened(epfile->ffs);
 892
 893         return 0;
 894 }
 895
 896 static int
 897 ffs_epfile_release(struct inode *inode, struct file *file)
 898 {
 899         struct ffs_epfile *epfile = inode->i_private;
 900
 901         ENTER();
 902
 903         ffs_data_closed(epfile->ffs);
 904
 905         return 0;
 906 }
 907
 908
 909 static long ffs_epfile_ioctl(struct file *file, unsigned code,
 910                              unsigned long value)
 911 {
 912         struct ffs_epfile *epfile = file->private_data;
 913         int ret;
 914
 915         ENTER();
 916
 917         if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
 918                 return -ENODEV;
 919
 920         spin_lock_irq(&epfile->ffs->eps_lock);
 921         if (likely(epfile->ep)) {
 922                 switch (code) {
 923                 case FUNCTIONFS_FIFO_STATUS:
 924                         ret = usb_ep_fifo_status(epfile->ep->ep);
 925                         break;
 926                 case FUNCTIONFS_FIFO_FLUSH:
 927                         usb_ep_fifo_flush(epfile->ep->ep);
 928                         ret = 0;
 929                         break;
 930                 case FUNCTIONFS_CLEAR_HALT:
 931                         ret = usb_ep_clear_halt(epfile->ep->ep);
 932                         break;
 933                 case FUNCTIONFS_ENDPOINT_REVMAP:
 934                         ret = epfile->ep->num;
 935                         break;
 936                 default:
 937                         ret = -ENOTTY;
 938                 }
 939         } else {
 940                 ret = -ENODEV;
 941         }
 942         spin_unlock_irq(&epfile->ffs->eps_lock);
 943
 944         return ret;
 945 }
 946
 947
 948 static const struct file_operations ffs_epfile_operations = {
 949         .owner =        THIS_MODULE,
 950         .llseek =       no_llseek,
 951
 952         .open =         ffs_epfile_open,
 953         .write =        ffs_epfile_write,
 954         .read =         ffs_epfile_read,
 955         .release =      ffs_epfile_release,
 956         .unlocked_ioctl =       ffs_epfile_ioctl,
 957 };
 958
 959
 960
 961 /* File system and super block operations ***********************************/
 962
 963 /*
 964  * Mounting the filesystem creates a controller file, used first for
 965  * function configuration then later for event monitoring.
 966  */
 967
 968
 969 static struct inode *__must_check
 970 ffs_sb_make_inode(struct super_block *sb, void *data,
 971                   const struct file_operations *fops,
 972                   const struct inode_operations *iops,
 973                   struct ffs_file_perms *perms)
 974 {
 975         struct inode *inode;
 976
 977         ENTER();
 978
 979         inode = new_inode(sb);
 980
 981         if (likely(inode)) {
 982                 struct timespec current_time = CURRENT_TIME;
 983
 984                 inode->i_mode    = perms->mode;
 985                 inode->i_uid     = perms->uid;
 986                 inode->i_gid     = perms->gid;
 987                 inode->i_atime   = current_time;
 988                 inode->i_mtime   = current_time;
 989                 inode->i_ctime   = current_time;
 990                 inode->i_private = data;
 991                 if (fops)
 992                         inode->i_fop = fops;
 993                 if (iops)
 994                         inode->i_op  = iops;
 995         }
 996
 997         return inode;
 998 }
 999
1000
1001 /* Create "regular" file */
1002
1003 static struct inode *ffs_sb_create_file(struct super_block *sb,
1004                                         const char *name, void *data,
1005                                         const struct file_operations *fops,
1006                                         struct dentry **dentry_p)
1007 {
1008         struct ffs_data *ffs = sb->s_fs_info;
1009         struct dentry   *dentry;
1010         struct inode    *inode;
1011
1012         ENTER();
1013
1014         dentry = d_alloc_name(sb->s_root, name);
1015         if (unlikely(!dentry))
1016                 return NULL;
1017
1018         inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1019         if (unlikely(!inode)) {
1020                 dput(dentry);
1021                 return NULL;
1022         }
1023
1024         d_add(dentry, inode);
1025         if (dentry_p)
1026                 *dentry_p = dentry;
1027
1028         return inode;
1029 }
1030
1031
1032 /* Super block */
1033
1034 static const struct super_operations ffs_sb_operations = {
1035         .statfs =       simple_statfs,
1036         .drop_inode =   generic_delete_inode,
1037 };
1038
1039 struct ffs_sb_fill_data {
1040         struct ffs_file_perms perms;
1041         umode_t root_mode;
1042         const char *dev_name;
1043 };
1044
1045 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
1046 {
1047         struct ffs_sb_fill_data *data = _data;
1048         struct inode    *inode;
1049         struct dentry   *d;
1050         struct ffs_data *ffs;
1051
1052         ENTER();
1053
1054         /* Initialize data */
1055         ffs = ffs_data_new();
1056         if (unlikely(!ffs))
1057                 goto enomem0;
1058
1059         ffs->sb              = sb;
1060         ffs->dev_name        = data->dev_name;
1061         ffs->file_perms      = data->perms;
1062
1063         sb->s_fs_info        = ffs;
1064         sb->s_blocksize      = PAGE_CACHE_SIZE;
1065         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1066         sb->s_magic          = FUNCTIONFS_MAGIC;
1067         sb->s_op             = &ffs_sb_operations;
1068         sb->s_time_gran      = 1;
1069
1070         /* Root inode */
1071         data->perms.mode = data->root_mode;
1072         inode = ffs_sb_make_inode(sb, NULL,
1073                                   &simple_dir_operations,
1074                                   &simple_dir_inode_operations,
1075                                   &data->perms);
1076         if (unlikely(!inode))
1077                 goto enomem1;
1078         d = d_alloc_root(inode);
1079         if (unlikely(!d))
1080                 goto enomem2;
1081         sb->s_root = d;
1082
1083         /* EP0 file */
1084         if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
1085                                          &ffs_ep0_operations, NULL)))
1086                 goto enomem3;
1087
1088         return 0;
1089
1090 enomem3:
1091         dput(d);
1092 enomem2:
1093         iput(inode);
1094 enomem1:
1095         ffs_data_put(ffs);
1096 enomem0:
1097         return -ENOMEM;
1098 }
1099
1100
1101 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
1102 {
1103         ENTER();
1104
1105         if (!opts || !*opts)
1106                 return 0;
1107
1108         for (;;) {
1109                 char *end, *eq, *comma;
1110                 unsigned long value;
1111
1112                 /* Option limit */
1113                 comma = strchr(opts, ',');
1114                 if (comma)
1115                         *comma = 0;
1116
1117                 /* Value limit */
1118                 eq = strchr(opts, '=');
1119                 if (unlikely(!eq)) {
1120                         FERR("'=' missing in %s", opts);
1121                         return -EINVAL;
1122                 }
1123                 *eq = 0;
1124
1125                 /* Parse value */
1126                 value = simple_strtoul(eq + 1, &end, 0);
1127                 if (unlikely(*end != ',' && *end != 0)) {
1128                         FERR("%s: invalid value: %s", opts, eq + 1);
1129                         return -EINVAL;
1130                 }
1131
1132                 /* Interpret option */
1133                 switch (eq - opts) {
1134                 case 5:
1135                         if (!memcmp(opts, "rmode", 5))
1136                                 data->root_mode  = (value & 0555) | S_IFDIR;
1137                         else if (!memcmp(opts, "fmode", 5))
1138                                 data->perms.mode = (value & 0666) | S_IFREG;
1139                         else
1140                                 goto invalid;
1141                         break;
1142
1143                 case 4:
1144                         if (!memcmp(opts, "mode", 4)) {
1145                                 data->root_mode  = (value & 0555) | S_IFDIR;
1146                                 data->perms.mode = (value & 0666) | S_IFREG;
1147                         } else {
1148                                 goto invalid;
1149                         }
1150                         break;
1151
1152                 case 3:
1153                         if (!memcmp(opts, "uid", 3))
1154                                 data->perms.uid = value;
1155                         else if (!memcmp(opts, "gid", 3))
1156                                 data->perms.gid = value;
1157                         else
1158                                 goto invalid;
1159                         break;
1160
1161                 default:
1162 invalid:
1163                         FERR("%s: invalid option", opts);
1164                         return -EINVAL;
1165                 }
1166
1167                 /* Next iteration */
1168                 if (!comma)
1169                         break;
1170                 opts = comma + 1;
1171         }
1172
1173         return 0;
1174 }
1175
1176
1177 /* "mount -t functionfs dev_name /dev/function" ends up here */
1178
1179 static int
1180 ffs_fs_get_sb(struct file_system_type *t, int flags,
1181               const char *dev_name, void *opts, struct vfsmount *mnt)
1182 {
1183         struct ffs_sb_fill_data data = {
1184                 .perms = {
1185                         .mode = S_IFREG | 0600,
1186                         .uid = 0,
1187                         .gid = 0
1188                 },
1189                 .root_mode = S_IFDIR | 0500,
1190         };
1191         int ret;
1192
1193         ENTER();
1194
1195         ret = functionfs_check_dev_callback(dev_name);
1196         if (unlikely(ret < 0))
1197                 return ret;
1198
1199         ret = ffs_fs_parse_opts(&data, opts);
1200         if (unlikely(ret < 0))
1201                 return ret;
1202
1203         data.dev_name = dev_name;
1204         return get_sb_single(t, flags, &data, ffs_sb_fill, mnt);
1205 }
1206
1207 static void
1208 ffs_fs_kill_sb(struct super_block *sb)
1209 {
1210         void *ptr;
1211
1212         ENTER();
1213
1214         kill_litter_super(sb);
1215         ptr = xchg(&sb->s_fs_info, NULL);
1216         if (ptr)
1217                 ffs_data_put(ptr);
1218 }
1219
1220 static struct file_system_type ffs_fs_type = {
1221         .owner          = THIS_MODULE,
1222         .name           = "functionfs",
1223         .get_sb         = ffs_fs_get_sb,
1224         .kill_sb        = ffs_fs_kill_sb,
1225 };
1226
1227
1228
1229 /* Driver's main init/cleanup functions *************************************/
1230
1231
1232 static int functionfs_init(void)
1233 {
1234         int ret;
1235
1236         ENTER();
1237
1238         ret = register_filesystem(&ffs_fs_type);
1239         if (likely(!ret))
1240                 FINFO("file system registered");
1241         else
1242                 FERR("failed registering file system (%d)", ret);
1243
1244         return ret;
1245 }
1246
1247 static void functionfs_cleanup(void)
1248 {
1249         ENTER();
1250
1251         FINFO("unloading");
1252         unregister_filesystem(&ffs_fs_type);
1253 }
1254
1255
1256
1257 /* ffs_data and ffs_function construction and destruction code **************/
1258
1259 static void ffs_data_clear(struct ffs_data *ffs);
1260 static void ffs_data_reset(struct ffs_data *ffs);
1261
1262
1263 static void ffs_data_get(struct ffs_data *ffs)
1264 {
1265         ENTER();
1266
1267         atomic_inc(&ffs->ref);
1268 }
1269
1270 static void ffs_data_opened(struct ffs_data *ffs)
1271 {
1272         ENTER();
1273
1274         atomic_inc(&ffs->ref);
1275         atomic_inc(&ffs->opened);
1276 }
1277
1278 static void ffs_data_put(struct ffs_data *ffs)
1279 {
1280         ENTER();
1281
1282         if (unlikely(atomic_dec_and_test(&ffs->ref))) {
1283                 FINFO("%s(): freeing", __func__);
1284                 ffs_data_clear(ffs);
1285                 BUG_ON(mutex_is_locked(&ffs->mutex) ||
1286                        spin_is_locked(&ffs->ev.waitq.lock) ||
1287                        waitqueue_active(&ffs->ev.waitq) ||
1288                        waitqueue_active(&ffs->ep0req_completion.wait));
1289                 kfree(ffs);
1290         }
1291 }
1292
1293
1294
1295 static void ffs_data_closed(struct ffs_data *ffs)
1296 {
1297         ENTER();
1298
1299         if (atomic_dec_and_test(&ffs->opened)) {
1300                 ffs->state = FFS_CLOSING;
1301                 ffs_data_reset(ffs);
1302         }
1303
1304         ffs_data_put(ffs);
1305 }
1306
1307
1308 static struct ffs_data *ffs_data_new(void)
1309 {
1310         struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1311         if (unlikely(!ffs))
1312                 return 0;
1313
1314         ENTER();
1315
1316         atomic_set(&ffs->ref, 1);
1317         atomic_set(&ffs->opened, 0);
1318         ffs->state = FFS_READ_DESCRIPTORS;
1319         mutex_init(&ffs->mutex);
1320         spin_lock_init(&ffs->eps_lock);
1321         init_waitqueue_head(&ffs->ev.waitq);
1322         init_completion(&ffs->ep0req_completion);
1323
1324         /* XXX REVISIT need to update it in some places, or do we? */
1325         ffs->ev.can_stall = 1;
1326
1327         return ffs;
1328 }
1329
1330
1331 static void ffs_data_clear(struct ffs_data *ffs)
1332 {
1333         ENTER();
1334
1335         if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags))
1336                 functionfs_closed_callback(ffs);
1337
1338         BUG_ON(ffs->gadget);
1339
1340         if (ffs->epfiles)
1341                 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1342
1343         kfree(ffs->raw_descs);
1344         kfree(ffs->raw_strings);
1345         kfree(ffs->stringtabs);
1346 }
1347
1348
1349 static void ffs_data_reset(struct ffs_data *ffs)
1350 {
1351         ENTER();
1352
1353         ffs_data_clear(ffs);
1354
1355         ffs->epfiles = NULL;
1356         ffs->raw_descs = NULL;
1357         ffs->raw_strings = NULL;
1358         ffs->stringtabs = NULL;
1359
1360         ffs->raw_descs_length = 0;
1361         ffs->raw_fs_descs_length = 0;
1362         ffs->fs_descs_count = 0;
1363         ffs->hs_descs_count = 0;
1364
1365         ffs->strings_count = 0;
1366         ffs->interfaces_count = 0;
1367         ffs->eps_count = 0;
1368
1369         ffs->ev.count = 0;
1370
1371         ffs->state = FFS_READ_DESCRIPTORS;
1372         ffs->setup_state = FFS_NO_SETUP;
1373         ffs->flags = 0;
1374 }
1375
1376
1377 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1378 {
1379         unsigned i, count;
1380
1381         ENTER();
1382
1383         if (WARN_ON(ffs->state != FFS_ACTIVE
1384                  || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1385                 return -EBADFD;
1386
1387         ffs_data_get(ffs);
1388
1389         ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1390         if (unlikely(!ffs->ep0req))
1391                 return -ENOMEM;
1392         ffs->ep0req->complete = ffs_ep0_complete;
1393         ffs->ep0req->context = ffs;
1394
1395         /* Get strings identifiers */
1396         for (count = ffs->strings_count, i = 0; i < count; ++i) {
1397                 struct usb_gadget_strings **lang;
1398
1399                 int id = usb_string_id(cdev);
1400                 if (unlikely(id < 0)) {
1401                         usb_ep_free_request(cdev->gadget->ep0, ffs->ep0req);
1402                         ffs->ep0req = NULL;
1403                         return id;
1404                 }
1405
1406                 lang = ffs->stringtabs;
1407                 do {
1408                         (*lang)->strings[i].id = id;
1409                         ++lang;
1410                 } while (*lang);
1411         }
1412
1413         ffs->gadget = cdev->gadget;
1414         return 0;
1415 }
1416
1417
1418 static void functionfs_unbind(struct ffs_data *ffs)
1419 {
1420         ENTER();
1421
1422         if (!WARN_ON(!ffs->gadget)) {
1423                 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1424                 ffs->ep0req = NULL;
1425                 ffs->gadget = NULL;
1426                 ffs_data_put(ffs);
1427         }
1428 }
1429
1430
1431 static int ffs_epfiles_create(struct ffs_data *ffs)
1432 {
1433         struct ffs_epfile *epfile, *epfiles;
1434         unsigned i, count;
1435
1436         ENTER();
1437
1438         count = ffs->eps_count;
1439         epfiles = kzalloc(count * sizeof *epfiles, GFP_KERNEL);
1440         if (!epfiles)
1441                 return -ENOMEM;
1442
1443         epfile = epfiles;
1444         for (i = 1; i <= count; ++i, ++epfile) {
1445                 epfile->ffs = ffs;
1446                 mutex_init(&epfile->mutex);
1447                 init_waitqueue_head(&epfile->wait);
1448                 sprintf(epfiles->name, "ep%u",  i);
1449                 if (!unlikely(ffs_sb_create_file(ffs->sb, epfiles->name, epfile,
1450                                                  &ffs_epfile_operations,
1451                                                  &epfile->dentry))) {
1452                         ffs_epfiles_destroy(epfiles, i - 1);
1453                         return -ENOMEM;
1454                 }
1455         }
1456
1457         ffs->epfiles = epfiles;
1458         return 0;
1459 }
1460
1461
1462 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1463 {
1464         struct ffs_epfile *epfile = epfiles;
1465
1466         ENTER();
1467
1468         for (; count; --count, ++epfile) {
1469                 BUG_ON(mutex_is_locked(&epfile->mutex) ||
1470                        waitqueue_active(&epfile->wait));
1471                 if (epfile->dentry) {
1472                         d_delete(epfile->dentry);
1473                         dput(epfile->dentry);
1474                         epfile->dentry = NULL;
1475                 }
1476         }
1477
1478         kfree(epfiles);
1479 }
1480
1481
1482 static int functionfs_add(struct usb_composite_dev *cdev,
1483                           struct usb_configuration *c,
1484                           struct ffs_data *ffs)
1485 {
1486         struct ffs_function *func;
1487         int ret;
1488
1489         ENTER();
1490
1491         func = kzalloc(sizeof *func, GFP_KERNEL);
1492         if (unlikely(!func))
1493                 return -ENOMEM;
1494
1495         func->function.name    = "Function FS Gadget";
1496         func->function.strings = ffs->stringtabs;
1497
1498         func->function.bind    = ffs_func_bind;
1499         func->function.unbind  = ffs_func_unbind;
1500         func->function.set_alt = ffs_func_set_alt;
1501         /*func->function.get_alt = ffs_func_get_alt;*/
1502         func->function.disable = ffs_func_disable;
1503         func->function.setup   = ffs_func_setup;
1504         func->function.suspend = ffs_func_suspend;
1505         func->function.resume  = ffs_func_resume;
1506
1507         func->conf   = c;
1508         func->gadget = cdev->gadget;
1509         func->ffs = ffs;
1510         ffs_data_get(ffs);
1511
1512         ret = usb_add_function(c, &func->function);
1513         if (unlikely(ret))
1514                 ffs_func_free(func);
1515
1516         return ret;
1517 }
1518
1519 static void ffs_func_free(struct ffs_function *func)
1520 {
1521         ENTER();
1522
1523         ffs_data_put(func->ffs);
1524
1525         kfree(func->eps);
1526         /* eps and interfaces_nums are allocated in the same chunk so
1527          * only one free is required.  Descriptors are also allocated
1528          * in the same chunk. */
1529
1530         kfree(func);
1531 }
1532
1533
1534 static void ffs_func_eps_disable(struct ffs_function *func)
1535 {
1536         struct ffs_ep *ep         = func->eps;
1537         struct ffs_epfile *epfile = func->ffs->epfiles;
1538         unsigned count            = func->ffs->eps_count;
1539         unsigned long flags;
1540
1541         spin_lock_irqsave(&func->ffs->eps_lock, flags);
1542         do {
1543                 /* pending requests get nuked */
1544                 if (likely(ep->ep))
1545                         usb_ep_disable(ep->ep);
1546                 epfile->ep = NULL;
1547
1548                 ++ep;
1549                 ++epfile;
1550         } while (--count);
1551         spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1552 }
1553
1554 static int ffs_func_eps_enable(struct ffs_function *func)
1555 {
1556         struct ffs_data *ffs      = func->ffs;
1557         struct ffs_ep *ep         = func->eps;
1558         struct ffs_epfile *epfile = ffs->epfiles;
1559         unsigned count            = ffs->eps_count;
1560         unsigned long flags;
1561         int ret = 0;
1562
1563         spin_lock_irqsave(&func->ffs->eps_lock, flags);
1564         do {
1565                 struct usb_endpoint_descriptor *ds;
1566                 ds = ep->descs[ep->descs[1] ? 1 : 0];
1567
1568                 ep->ep->driver_data = ep;
1569                 ret = usb_ep_enable(ep->ep, ds);
1570                 if (likely(!ret)) {
1571                         epfile->ep = ep;
1572                         epfile->in = usb_endpoint_dir_in(ds);
1573                         epfile->isoc = usb_endpoint_xfer_isoc(ds);
1574                 } else {
1575                         break;
1576                 }
1577
1578                 wake_up(&epfile->wait);
1579
1580                 ++ep;
1581                 ++epfile;
1582         } while (--count);
1583         spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1584
1585         return ret;
1586 }
1587
1588
1589 /* Parsing and building descriptors and strings *****************************/
1590
1591
1592 /* This validates if data pointed by data is a valid USB descriptor as
1593  * well as record how many interfaces, endpoints and strings are
1594  * required by given configuration.  Returns address afther the
1595  * descriptor or NULL if data is invalid. */
1596
1597 enum ffs_entity_type {
1598         FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1599 };
1600
1601 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1602                                    u8 *valuep,
1603                                    struct usb_descriptor_header *desc,
1604                                    void *priv);
1605
1606 static int __must_check ffs_do_desc(char *data, unsigned len,
1607                                     ffs_entity_callback entity, void *priv)
1608 {
1609         struct usb_descriptor_header *_ds = (void *)data;
1610         u8 length;
1611         int ret;
1612
1613         ENTER();
1614
1615         /* At least two bytes are required: length and type */
1616         if (len < 2) {
1617                 FVDBG("descriptor too short");
1618                 return -EINVAL;
1619         }
1620
1621         /* If we have at least as many bytes as the descriptor takes? */
1622         length = _ds->bLength;
1623         if (len < length) {
1624                 FVDBG("descriptor longer then available data");
1625                 return -EINVAL;
1626         }
1627
1628 #define __entity_check_INTERFACE(val)  1
1629 #define __entity_check_STRING(val)     (val)
1630 #define __entity_check_ENDPOINT(val)   ((val) & USB_ENDPOINT_NUMBER_MASK)
1631 #define __entity(type, val) do {                                        \
1632                 FVDBG("entity " #type "(%02x)", (val));                 \
1633                 if (unlikely(!__entity_check_ ##type(val))) {           \
1634                         FVDBG("invalid entity's value");                \
1635                         return -EINVAL;                                 \
1636                 }                                                       \
1637                 ret = entity(FFS_ ##type, &val, _ds, priv);             \
1638                 if (unlikely(ret < 0)) {                                \
1639                         FDBG("entity " #type "(%02x); ret = %d",        \
1640                              (val), ret);                               \
1641                         return ret;                                     \
1642                 }                                                       \
1643         } while (0)
1644
1645         /* Parse descriptor depending on type. */
1646         switch (_ds->bDescriptorType) {
1647         case USB_DT_DEVICE:
1648         case USB_DT_CONFIG:
1649         case USB_DT_STRING:
1650         case USB_DT_DEVICE_QUALIFIER:
1651                 /* function can't have any of those */
1652                 FVDBG("descriptor reserved for gadget: %d", _ds->bDescriptorType);
1653                 return -EINVAL;
1654
1655         case USB_DT_INTERFACE: {
1656                 struct usb_interface_descriptor *ds = (void *)_ds;
1657                 FVDBG("interface descriptor");
1658                 if (length != sizeof *ds)
1659                         goto inv_length;
1660
1661                 __entity(INTERFACE, ds->bInterfaceNumber);
1662                 if (ds->iInterface)
1663                         __entity(STRING, ds->iInterface);
1664         }
1665                 break;
1666
1667         case USB_DT_ENDPOINT: {
1668                 struct usb_endpoint_descriptor *ds = (void *)_ds;
1669                 FVDBG("endpoint descriptor");
1670                 if (length != USB_DT_ENDPOINT_SIZE &&
1671                     length != USB_DT_ENDPOINT_AUDIO_SIZE)
1672                         goto inv_length;
1673                 __entity(ENDPOINT, ds->bEndpointAddress);
1674         }
1675                 break;
1676
1677         case USB_DT_OTG:
1678                 if (length != sizeof(struct usb_otg_descriptor))
1679                         goto inv_length;
1680                 break;
1681
1682         case USB_DT_INTERFACE_ASSOCIATION: {
1683                 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
1684                 FVDBG("interface association descriptor");
1685                 if (length != sizeof *ds)
1686                         goto inv_length;
1687                 if (ds->iFunction)
1688                         __entity(STRING, ds->iFunction);
1689         }
1690                 break;
1691
1692         case USB_DT_OTHER_SPEED_CONFIG:
1693         case USB_DT_INTERFACE_POWER:
1694         case USB_DT_DEBUG:
1695         case USB_DT_SECURITY:
1696         case USB_DT_CS_RADIO_CONTROL:
1697                 /* TODO */
1698                 FVDBG("unimplemented descriptor: %d", _ds->bDescriptorType);
1699                 return -EINVAL;
1700
1701         default:
1702                 /* We should never be here */
1703                 FVDBG("unknown descriptor: %d", _ds->bDescriptorType);
1704                 return -EINVAL;
1705
1706         inv_length:
1707                 FVDBG("invalid length: %d (descriptor %d)",
1708                       _ds->bLength, _ds->bDescriptorType);
1709                 return -EINVAL;
1710         }
1711
1712 #undef __entity
1713 #undef __entity_check_DESCRIPTOR
1714 #undef __entity_check_INTERFACE
1715 #undef __entity_check_STRING
1716 #undef __entity_check_ENDPOINT
1717
1718         return length;
1719 }
1720
1721
1722 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
1723                                      ffs_entity_callback entity, void *priv)
1724 {
1725         const unsigned _len = len;
1726         unsigned long num = 0;
1727
1728         ENTER();
1729
1730         for (;;) {
1731                 int ret;
1732
1733                 if (num == count)
1734                         data = NULL;
1735
1736                 /* Record "descriptor" entitny */
1737                 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
1738                 if (unlikely(ret < 0)) {
1739                         FDBG("entity DESCRIPTOR(%02lx); ret = %d", num, ret);
1740                         return ret;
1741                 }
1742
1743                 if (!data)
1744                         return _len - len;
1745
1746                 ret = ffs_do_desc(data, len, entity, priv);
1747                 if (unlikely(ret < 0)) {
1748                         FDBG("%s returns %d", __func__, ret);
1749                         return ret;
1750                 }
1751
1752                 len -= ret;
1753                 data += ret;
1754                 ++num;
1755         }
1756 }
1757
1758
1759 static int __ffs_data_do_entity(enum ffs_entity_type type,
1760                                 u8 *valuep, struct usb_descriptor_header *desc,
1761                                 void *priv)
1762 {
1763         struct ffs_data *ffs = priv;
1764
1765         ENTER();
1766
1767         switch (type) {
1768         case FFS_DESCRIPTOR:
1769                 break;
1770
1771         case FFS_INTERFACE:
1772                 /* Interfaces are indexed from zero so if we
1773                  * encountered interface "n" then there are at least
1774                  * "n+1" interfaces. */
1775                 if (*valuep >= ffs->interfaces_count)
1776                         ffs->interfaces_count = *valuep + 1;
1777                 break;
1778
1779         case FFS_STRING:
1780                 /* Strings are indexed from 1 (0 is magic ;) reserved
1781                  * for languages list or some such) */
1782                 if (*valuep > ffs->strings_count)
1783                         ffs->strings_count = *valuep;
1784                 break;
1785
1786         case FFS_ENDPOINT:
1787                 /* Endpoints are indexed from 1 as well. */
1788                 if ((*valuep & USB_ENDPOINT_NUMBER_MASK) > ffs->eps_count)
1789                         ffs->eps_count = (*valuep & USB_ENDPOINT_NUMBER_MASK);
1790                 break;
1791         }
1792
1793         return 0;
1794 }
1795
1796
1797 static int __ffs_data_got_descs(struct ffs_data *ffs,
1798                                 char *const _data, size_t len)
1799 {
1800         unsigned fs_count, hs_count;
1801         int fs_len, ret = -EINVAL;
1802         char *data = _data;
1803
1804         ENTER();
1805
1806         if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_DESCRIPTORS_MAGIC ||
1807                      get_unaligned_le32(data + 4) != len))
1808                 goto error;
1809         fs_count = get_unaligned_le32(data +  8);
1810         hs_count = get_unaligned_le32(data + 12);
1811
1812         if (!fs_count && !hs_count)
1813                 goto einval;
1814
1815         data += 16;
1816         len  -= 16;
1817
1818         if (likely(fs_count)) {
1819                 fs_len = ffs_do_descs(fs_count, data, len,
1820                                       __ffs_data_do_entity, ffs);
1821                 if (unlikely(fs_len < 0)) {
1822                         ret = fs_len;
1823                         goto error;
1824                 }
1825
1826                 data += fs_len;
1827                 len  -= fs_len;
1828         } else {
1829                 fs_len = 0;
1830         }
1831
1832         if (likely(hs_count)) {
1833                 ret = ffs_do_descs(hs_count, data, len,
1834                                    __ffs_data_do_entity, ffs);
1835                 if (unlikely(ret < 0))
1836                         goto error;
1837         } else {
1838                 ret = 0;
1839         }
1840
1841         if (unlikely(len != ret))
1842                 goto einval;
1843
1844         ffs->raw_fs_descs_length = fs_len;
1845         ffs->raw_descs_length    = fs_len + ret;
1846         ffs->raw_descs           = _data;
1847         ffs->fs_descs_count      = fs_count;
1848         ffs->hs_descs_count      = hs_count;
1849
1850         return 0;
1851
1852 einval:
1853         ret = -EINVAL;
1854 error:
1855         kfree(_data);
1856         return ret;
1857 }
1858
1859
1860
1861 static int __ffs_data_got_strings(struct ffs_data *ffs,
1862                                   char *const _data, size_t len)
1863 {
1864         u32 str_count, needed_count, lang_count;
1865         struct usb_gadget_strings **stringtabs, *t;
1866         struct usb_string *strings, *s;
1867         const char *data = _data;
1868
1869         ENTER();
1870
1871         if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
1872                      get_unaligned_le32(data + 4) != len))
1873                 goto error;
1874         str_count  = get_unaligned_le32(data + 8);
1875         lang_count = get_unaligned_le32(data + 12);
1876
1877         /* if one is zero the other must be zero */
1878         if (unlikely(!str_count != !lang_count))
1879                 goto error;
1880
1881         /* Do we have at least as many strings as descriptors need? */
1882         needed_count = ffs->strings_count;
1883         if (unlikely(str_count < needed_count))
1884                 goto error;
1885
1886         /* If we don't need any strings just return and free all
1887          * memory */
1888         if (!needed_count) {
1889                 kfree(_data);
1890                 return 0;
1891         }
1892
1893         /* Allocate */
1894         {
1895                 /* Allocate everything in one chunk so there's less
1896                  * maintanance. */
1897                 struct {
1898                         struct usb_gadget_strings *stringtabs[lang_count + 1];
1899                         struct usb_gadget_strings stringtab[lang_count];
1900                         struct usb_string strings[lang_count*(needed_count+1)];
1901                 } *d;
1902                 unsigned i = 0;
1903
1904                 d = kmalloc(sizeof *d, GFP_KERNEL);
1905                 if (unlikely(!d)) {
1906                         kfree(_data);
1907                         return -ENOMEM;
1908                 }
1909
1910                 stringtabs = d->stringtabs;
1911                 t = d->stringtab;
1912                 i = lang_count;
1913                 do {
1914                         *stringtabs++ = t++;
1915                 } while (--i);
1916                 *stringtabs = NULL;
1917
1918                 stringtabs = d->stringtabs;
1919                 t = d->stringtab;
1920                 s = d->strings;
1921                 strings = s;
1922         }
1923
1924         /* For each language */
1925         data += 16;
1926         len -= 16;
1927
1928         do { /* lang_count > 0 so we can use do-while */
1929                 unsigned needed = needed_count;
1930
1931                 if (unlikely(len < 3))
1932                         goto error_free;
1933                 t->language = get_unaligned_le16(data);
1934                 t->strings  = s;
1935                 ++t;
1936
1937                 data += 2;
1938                 len -= 2;
1939
1940                 /* For each string */
1941                 do { /* str_count > 0 so we can use do-while */
1942                         size_t length = strnlen(data, len);
1943
1944                         if (unlikely(length == len))
1945                                 goto error_free;
1946
1947                         /* user may provide more strings then we need,
1948                          * if that's the case we simply ingore the
1949                          * rest */
1950                         if (likely(needed)) {
1951                                 /* s->id will be set while adding
1952                                  * function to configuration so for
1953                                  * now just leave garbage here. */
1954                                 s->s = data;
1955                                 --needed;
1956                                 ++s;
1957                         }
1958
1959                         data += length + 1;
1960                         len -= length + 1;
1961                 } while (--str_count);
1962
1963                 s->id = 0;   /* terminator */
1964                 s->s = NULL;
1965                 ++s;
1966
1967         } while (--lang_count);
1968
1969         /* Some garbage left? */
1970         if (unlikely(len))
1971                 goto error_free;
1972
1973         /* Done! */
1974         ffs->stringtabs = stringtabs;
1975         ffs->raw_strings = _data;
1976
1977         return 0;
1978
1979 error_free:
1980         kfree(stringtabs);
1981 error:
1982         kfree(_data);
1983         return -EINVAL;
1984 }
1985
1986
1987
1988
1989 /* Events handling and management *******************************************/
1990
1991 static void __ffs_event_add(struct ffs_data *ffs,
1992                             enum usb_functionfs_event_type type)
1993 {
1994         enum usb_functionfs_event_type rem_type1, rem_type2 = type;
1995         int neg = 0;
1996
1997         /* Abort any unhandled setup */
1998         /* We do not need to worry about some cmpxchg() changing value
1999          * of ffs->setup_state without holding the lock because when
2000          * state is FFS_SETUP_PENDING cmpxchg() in several places in
2001          * the source does nothing. */
2002         if (ffs->setup_state == FFS_SETUP_PENDING)
2003                 ffs->setup_state = FFS_SETUP_CANCELED;
2004
2005         switch (type) {
2006         case FUNCTIONFS_RESUME:
2007                 rem_type2 = FUNCTIONFS_SUSPEND;
2008                 /* FALL THGOUTH */
2009         case FUNCTIONFS_SUSPEND:
2010         case FUNCTIONFS_SETUP:
2011                 rem_type1 = type;
2012                 /* discard all similar events */
2013                 break;
2014
2015         case FUNCTIONFS_BIND:
2016         case FUNCTIONFS_UNBIND:
2017         case FUNCTIONFS_DISABLE:
2018         case FUNCTIONFS_ENABLE:
2019                 /* discard everything other then power management. */
2020                 rem_type1 = FUNCTIONFS_SUSPEND;
2021                 rem_type2 = FUNCTIONFS_RESUME;
2022                 neg = 1;
2023                 break;
2024
2025         default:
2026                 BUG();
2027         }
2028
2029         {
2030                 u8 *ev  = ffs->ev.types, *out = ev;
2031                 unsigned n = ffs->ev.count;
2032                 for (; n; --n, ++ev)
2033                         if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2034                                 *out++ = *ev;
2035                         else
2036                                 FVDBG("purging event %d", *ev);
2037                 ffs->ev.count = out - ffs->ev.types;
2038         }
2039
2040         FVDBG("adding event %d", type);
2041         ffs->ev.types[ffs->ev.count++] = type;
2042         wake_up_locked(&ffs->ev.waitq);
2043 }
2044
2045 static void ffs_event_add(struct ffs_data *ffs,
2046                           enum usb_functionfs_event_type type)
2047 {
2048         unsigned long flags;
2049         spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2050         __ffs_event_add(ffs, type);
2051         spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2052 }
2053
2054
2055 /* Bind/unbind USB function hooks *******************************************/
2056
2057 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2058                                     struct usb_descriptor_header *desc,
2059                                     void *priv)
2060 {
2061         struct usb_endpoint_descriptor *ds = (void *)desc;
2062         struct ffs_function *func = priv;
2063         struct ffs_ep *ffs_ep;
2064
2065         /* If hs_descriptors is not NULL then we are reading hs
2066          * descriptors now */
2067         const int isHS = func->function.hs_descriptors != NULL;
2068         unsigned idx;
2069
2070         if (type != FFS_DESCRIPTOR)
2071                 return 0;
2072
2073         if (isHS)
2074                 func->function.hs_descriptors[(long)valuep] = desc;
2075         else
2076                 func->function.descriptors[(long)valuep]    = desc;
2077
2078         if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2079                 return 0;
2080
2081         idx = (ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK) - 1;
2082         ffs_ep = func->eps + idx;
2083
2084         if (unlikely(ffs_ep->descs[isHS])) {
2085                 FVDBG("two %sspeed descriptors for EP %d",
2086                       isHS ? "high" : "full",
2087                       ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2088                 return -EINVAL;
2089         }
2090         ffs_ep->descs[isHS] = ds;
2091
2092         ffs_dump_mem(": Original  ep desc", ds, ds->bLength);
2093         if (ffs_ep->ep) {
2094                 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2095                 if (!ds->wMaxPacketSize)
2096                         ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2097         } else {
2098                 struct usb_request *req;
2099                 struct usb_ep *ep;
2100
2101                 FVDBG("autoconfig");
2102                 ep = usb_ep_autoconfig(func->gadget, ds);
2103                 if (unlikely(!ep))
2104                         return -ENOTSUPP;
2105                 ep->driver_data = func->eps + idx;;
2106
2107                 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2108                 if (unlikely(!req))
2109                         return -ENOMEM;
2110
2111                 ffs_ep->ep  = ep;
2112                 ffs_ep->req = req;
2113                 func->eps_revmap[ds->bEndpointAddress &
2114                                  USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2115         }
2116         ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2117
2118         return 0;
2119 }
2120
2121
2122 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2123                                    struct usb_descriptor_header *desc,
2124                                    void *priv)
2125 {
2126         struct ffs_function *func = priv;
2127         unsigned idx;
2128         u8 newValue;
2129
2130         switch (type) {
2131         default:
2132         case FFS_DESCRIPTOR:
2133                 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2134                 return 0;
2135
2136         case FFS_INTERFACE:
2137                 idx = *valuep;
2138                 if (func->interfaces_nums[idx] < 0) {
2139                         int id = usb_interface_id(func->conf, &func->function);
2140                         if (unlikely(id < 0))
2141                                 return id;
2142                         func->interfaces_nums[idx] = id;
2143                 }
2144                 newValue = func->interfaces_nums[idx];
2145                 break;
2146
2147         case FFS_STRING:
2148                 /* String' IDs are allocated when fsf_data is bound to cdev */
2149                 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2150                 break;
2151
2152         case FFS_ENDPOINT:
2153                 /* USB_DT_ENDPOINT are handled in
2154                  * __ffs_func_bind_do_descs(). */
2155                 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2156                         return 0;
2157
2158                 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2159                 if (unlikely(!func->eps[idx].ep))
2160                         return -EINVAL;
2161
2162                 {
2163                         struct usb_endpoint_descriptor **descs;
2164                         descs = func->eps[idx].descs;
2165                         newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2166                 }
2167                 break;
2168         }
2169
2170         FVDBG("%02x -> %02x", *valuep, newValue);
2171         *valuep = newValue;
2172         return 0;
2173 }
2174
2175 static int ffs_func_bind(struct usb_configuration *c,
2176                          struct usb_function *f)
2177 {
2178         struct ffs_function *func = ffs_func_from_usb(f);
2179         struct ffs_data *ffs = func->ffs;
2180
2181         const int full = !!func->ffs->fs_descs_count;
2182         const int high = gadget_is_dualspeed(func->gadget) &&
2183                 func->ffs->hs_descs_count;
2184
2185         int ret;
2186
2187         /* Make it a single chunk, less management later on */
2188         struct {
2189                 struct ffs_ep eps[ffs->eps_count];
2190                 struct usb_descriptor_header
2191                         *fs_descs[full ? ffs->fs_descs_count + 1 : 0];
2192                 struct usb_descriptor_header
2193                         *hs_descs[high ? ffs->hs_descs_count + 1 : 0];
2194                 short inums[ffs->interfaces_count];
2195                 char raw_descs[high ? ffs->raw_descs_length
2196                                     : ffs->raw_fs_descs_length];
2197         } *data;
2198
2199         ENTER();
2200
2201         /* Only high speed but not supported by gadget? */
2202         if (unlikely(!(full | high)))
2203                 return -ENOTSUPP;
2204
2205         /* Allocate */
2206         data = kmalloc(sizeof *data, GFP_KERNEL);
2207         if (unlikely(!data))
2208                 return -ENOMEM;
2209
2210         /* Zero */
2211         memset(data->eps, 0, sizeof data->eps);
2212         memcpy(data->raw_descs, ffs->raw_descs + 16, sizeof data->raw_descs);
2213         memset(data->inums, 0xff, sizeof data->inums);
2214         for (ret = ffs->eps_count; ret; --ret)
2215                 data->eps[ret].num = -1;
2216
2217         /* Save pointers */
2218         func->eps             = data->eps;
2219         func->interfaces_nums = data->inums;
2220
2221         /* Go throught all the endpoint descriptors and allocate
2222          * endpoints first, so that later we can rewrite the endpoint
2223          * numbers without worying that it may be described later on. */
2224         if (likely(full)) {
2225                 func->function.descriptors = data->fs_descs;
2226                 ret = ffs_do_descs(ffs->fs_descs_count,
2227                                    data->raw_descs,
2228                                    sizeof data->raw_descs,
2229                                    __ffs_func_bind_do_descs, func);
2230                 if (unlikely(ret < 0))
2231                         goto error;
2232         } else {
2233                 ret = 0;
2234         }
2235
2236         if (likely(high)) {
2237                 func->function.hs_descriptors = data->hs_descs;
2238                 ret = ffs_do_descs(ffs->hs_descs_count,
2239                                    data->raw_descs + ret,
2240                                    (sizeof data->raw_descs) - ret,
2241                                    __ffs_func_bind_do_descs, func);
2242         }
2243
2244         /* Now handle interface numbers allocation and interface and
2245          * enpoint numbers rewritting.  We can do that in one go
2246          * now. */
2247         ret = ffs_do_descs(ffs->fs_descs_count +
2248                            (high ? ffs->hs_descs_count : 0),
2249                            data->raw_descs, sizeof data->raw_descs,
2250                            __ffs_func_bind_do_nums, func);
2251         if (unlikely(ret < 0))
2252                 goto error;
2253
2254         /* And we're done */
2255         ffs_event_add(ffs, FUNCTIONFS_BIND);
2256         return 0;
2257
2258 error:
2259         /* XXX Do we need to release all claimed endpoints here? */
2260         return ret;
2261 }
2262
2263
2264 /* Other USB function hooks *************************************************/
2265
2266 static void ffs_func_unbind(struct usb_configuration *c,
2267                             struct usb_function *f)
2268 {
2269         struct ffs_function *func = ffs_func_from_usb(f);
2270         struct ffs_data *ffs = func->ffs;
2271
2272         ENTER();
2273
2274         if (ffs->func == func) {
2275                 ffs_func_eps_disable(func);
2276                 ffs->func = NULL;
2277         }
2278
2279         ffs_event_add(ffs, FUNCTIONFS_UNBIND);
2280
2281         ffs_func_free(func);
2282 }
2283
2284
2285 static int ffs_func_set_alt(struct usb_function *f,
2286                             unsigned interface, unsigned alt)
2287 {
2288         struct ffs_function *func = ffs_func_from_usb(f);
2289         struct ffs_data *ffs = func->ffs;
2290         int ret = 0, intf;
2291
2292         if (alt != (unsigned)-1) {
2293                 intf = ffs_func_revmap_intf(func, interface);
2294                 if (unlikely(intf < 0))
2295                         return intf;
2296         }
2297
2298         if (ffs->func)
2299                 ffs_func_eps_disable(ffs->func);
2300
2301         if (ffs->state != FFS_ACTIVE)
2302                 return -ENODEV;
2303
2304         if (alt == (unsigned)-1) {
2305                 ffs->func = NULL;
2306                 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
2307                 return 0;
2308         }
2309
2310         ffs->func = func;
2311         ret = ffs_func_eps_enable(func);
2312         if (likely(ret >= 0))
2313                 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
2314         return ret;
2315 }
2316
2317 static void ffs_func_disable(struct usb_function *f)
2318 {
2319         ffs_func_set_alt(f, 0, (unsigned)-1);
2320 }
2321
2322 static int ffs_func_setup(struct usb_function *f,
2323                           const struct usb_ctrlrequest *creq)
2324 {
2325         struct ffs_function *func = ffs_func_from_usb(f);
2326         struct ffs_data *ffs = func->ffs;
2327         unsigned long flags;
2328         int ret;
2329
2330         ENTER();
2331
2332         FVDBG("creq->bRequestType = %02x", creq->bRequestType);
2333         FVDBG("creq->bRequest     = %02x", creq->bRequest);
2334         FVDBG("creq->wValue       = %04x", le16_to_cpu(creq->wValue));
2335         FVDBG("creq->wIndex       = %04x", le16_to_cpu(creq->wIndex));
2336         FVDBG("creq->wLength      = %04x", le16_to_cpu(creq->wLength));
2337
2338         /* Most requests directed to interface go throught here
2339          * (notable exceptions are set/get interface) so we need to
2340          * handle them.  All other either handled by composite or
2341          * passed to usb_configuration->setup() (if one is set).  No
2342          * matter, we will handle requests directed to endpoint here
2343          * as well (as it's straightforward) but what to do with any
2344          * other request? */
2345
2346         if (ffs->state != FFS_ACTIVE)
2347                 return -ENODEV;
2348
2349         switch (creq->bRequestType & USB_RECIP_MASK) {
2350         case USB_RECIP_INTERFACE:
2351                 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
2352                 if (unlikely(ret < 0))
2353                         return ret;
2354                 break;
2355
2356         case USB_RECIP_ENDPOINT:
2357                 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
2358                 if (unlikely(ret < 0))
2359                         return ret;
2360                 break;
2361
2362         default:
2363                 return -EOPNOTSUPP;
2364         }
2365
2366         spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2367         ffs->ev.setup = *creq;
2368         ffs->ev.setup.wIndex = cpu_to_le16(ret);
2369         __ffs_event_add(ffs, FUNCTIONFS_SETUP);
2370         spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2371
2372         return 0;
2373 }
2374
2375 static void ffs_func_suspend(struct usb_function *f)
2376 {
2377         ENTER();
2378         ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
2379 }
2380
2381 static void ffs_func_resume(struct usb_function *f)
2382 {
2383         ENTER();
2384         ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
2385 }
2386
2387
2388
2389 /* Enpoint and interface numbers reverse mapping ****************************/
2390
2391 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
2392 {
2393         num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
2394         return num ? num : -EDOM;
2395 }
2396
2397 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
2398 {
2399         short *nums = func->interfaces_nums;
2400         unsigned count = func->ffs->interfaces_count;
2401
2402         for (; count; --count, ++nums) {
2403                 if (*nums >= 0 && *nums == intf)
2404                         return nums - func->interfaces_nums;
2405         }
2406
2407         return -EDOM;
2408 }
2409
2410
2411 /* Misc helper functions ****************************************************/
2412
2413 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
2414 {
2415         return nonblock
2416                 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
2417                 : mutex_lock_interruptible(mutex);
2418 }
2419
2420
2421 static char *ffs_prepare_buffer(const char * __user buf, size_t len)
2422 {
2423         char *data;
2424
2425         if (unlikely(!len))
2426                 return NULL;
2427
2428         data = kmalloc(len, GFP_KERNEL);
2429         if (unlikely(!data))
2430                 return ERR_PTR(-ENOMEM);
2431
2432         if (unlikely(__copy_from_user(data, buf, len))) {
2433                 kfree(data);
2434                 return ERR_PTR(-EFAULT);
2435         }
2436
2437         FVDBG("Buffer from user space:");
2438         ffs_dump_mem("", data, len);
2439
2440         return data;
2441 }