1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * inode.c -- user mode filesystem api for usb gadget controllers 4 * 5 * Copyright (C) 2003-2004 David Brownell 6 * Copyright (C) 2003 Agilent Technologies 7 */ 8 9 10 /* #define VERBOSE_DEBUG */ 11 12 #include <linux/init.h> 13 #include <linux/module.h> 14 #include <linux/fs.h> 15 #include <linux/fs_context.h> 16 #include <linux/pagemap.h> 17 #include <linux/uts.h> 18 #include <linux/wait.h> 19 #include <linux/compiler.h> 20 #include <linux/uaccess.h> 21 #include <linux/sched.h> 22 #include <linux/slab.h> 23 #include <linux/poll.h> 24 #include <linux/kthread.h> 25 #include <linux/aio.h> 26 #include <linux/uio.h> 27 #include <linux/refcount.h> 28 #include <linux/delay.h> 29 #include <linux/device.h> 30 #include <linux/moduleparam.h> 31 32 #include <linux/usb/gadgetfs.h> 33 #include <linux/usb/gadget.h> 34 #include <linux/usb/composite.h> /* for USB_GADGET_DELAYED_STATUS */ 35 36 /* Undef helpers from linux/usb/composite.h as gadgetfs redefines them */ 37 #undef DBG 38 #undef ERROR 39 #undef INFO 40 41 42 /* 43 * The gadgetfs API maps each endpoint to a file descriptor so that you 44 * can use standard synchronous read/write calls for I/O. There's some 45 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode 46 * drivers show how this works in practice. You can also use AIO to 47 * eliminate I/O gaps between requests, to help when streaming data. 48 * 49 * Key parts that must be USB-specific are protocols defining how the 50 * read/write operations relate to the hardware state machines. There 51 * are two types of files. One type is for the device, implementing ep0. 52 * The other type is for each IN or OUT endpoint. In both cases, the 53 * user mode driver must configure the hardware before using it. 54 * 55 * - First, dev_config() is called when /dev/gadget/$CHIP is configured 56 * (by writing configuration and device descriptors). Afterwards it 57 * may serve as a source of device events, used to handle all control 58 * requests other than basic enumeration. 59 * 60 * - Then, after a SET_CONFIGURATION control request, ep_config() is 61 * called when each /dev/gadget/ep* file is configured (by writing 62 * endpoint descriptors). Afterwards these files are used to write() 63 * IN data or to read() OUT data. To halt the endpoint, a "wrong 64 * direction" request is issued (like reading an IN endpoint). 65 * 66 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe 67 * not possible on all hardware. For example, precise fault handling with 68 * respect to data left in endpoint fifos after aborted operations; or 69 * selective clearing of endpoint halts, to implement SET_INTERFACE. 70 */ 71 72 #define DRIVER_DESC "USB Gadget filesystem" 73 #define DRIVER_VERSION "24 Aug 2004" 74 75 static const char driver_desc [] = DRIVER_DESC; 76 static const char shortname [] = "gadgetfs"; 77 78 MODULE_DESCRIPTION (DRIVER_DESC); 79 MODULE_AUTHOR ("David Brownell"); 80 MODULE_LICENSE ("GPL"); 81 82 static int ep_open(struct inode *, struct file *); 83 84 85 /*----------------------------------------------------------------------*/ 86 87 #define GADGETFS_MAGIC 0xaee71ee7 88 89 /* /dev/gadget/$CHIP represents ep0 and the whole device */ 90 enum ep0_state { 91 /* DISABLED is the initial state. */ 92 STATE_DEV_DISABLED = 0, 93 94 /* Only one open() of /dev/gadget/$CHIP; only one file tracks 95 * ep0/device i/o modes and binding to the controller. Driver 96 * must always write descriptors to initialize the device, then 97 * the device becomes UNCONNECTED until enumeration. 98 */ 99 STATE_DEV_OPENED, 100 101 /* From then on, ep0 fd is in either of two basic modes: 102 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it 103 * - SETUP: read/write will transfer control data and succeed; 104 * or if "wrong direction", performs protocol stall 105 */ 106 STATE_DEV_UNCONNECTED, 107 STATE_DEV_CONNECTED, 108 STATE_DEV_SETUP, 109 110 /* UNBOUND means the driver closed ep0, so the device won't be 111 * accessible again (DEV_DISABLED) until all fds are closed. 112 */ 113 STATE_DEV_UNBOUND, 114 }; 115 116 /* enough for the whole queue: most events invalidate others */ 117 #define N_EVENT 5 118 119 #define RBUF_SIZE 256 120 121 struct dev_data { 122 spinlock_t lock; 123 refcount_t count; 124 int udc_usage; 125 enum ep0_state state; /* P: lock */ 126 struct usb_gadgetfs_event event [N_EVENT]; 127 unsigned ev_next; 128 struct fasync_struct *fasync; 129 u8 current_config; 130 131 /* drivers reading ep0 MUST handle control requests (SETUP) 132 * reported that way; else the host will time out. 133 */ 134 unsigned usermode_setup : 1, 135 setup_in : 1, 136 setup_can_stall : 1, 137 setup_out_ready : 1, 138 setup_out_error : 1, 139 setup_abort : 1, 140 gadget_registered : 1; 141 unsigned setup_wLength; 142 143 /* the rest is basically write-once */ 144 struct usb_config_descriptor *config, *hs_config; 145 struct usb_device_descriptor *dev; 146 struct usb_request *req; 147 struct usb_gadget *gadget; 148 struct list_head epfiles; 149 void *buf; 150 wait_queue_head_t wait; 151 struct super_block *sb; 152 struct dentry *dentry; 153 154 /* except this scratch i/o buffer for ep0 */ 155 u8 rbuf[RBUF_SIZE]; 156 }; 157 158 static inline void get_dev (struct dev_data *data) 159 { 160 refcount_inc (&data->count); 161 } 162 163 static void put_dev (struct dev_data *data) 164 { 165 if (likely (!refcount_dec_and_test (&data->count))) 166 return; 167 /* needs no more cleanup */ 168 BUG_ON (waitqueue_active (&data->wait)); 169 kfree (data); 170 } 171 172 static struct dev_data *dev_new (void) 173 { 174 struct dev_data *dev; 175 176 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 177 if (!dev) 178 return NULL; 179 dev->state = STATE_DEV_DISABLED; 180 refcount_set (&dev->count, 1); 181 spin_lock_init (&dev->lock); 182 INIT_LIST_HEAD (&dev->epfiles); 183 init_waitqueue_head (&dev->wait); 184 return dev; 185 } 186 187 /*----------------------------------------------------------------------*/ 188 189 /* other /dev/gadget/$ENDPOINT files represent endpoints */ 190 enum ep_state { 191 STATE_EP_DISABLED = 0, 192 STATE_EP_READY, 193 STATE_EP_ENABLED, 194 STATE_EP_UNBOUND, 195 }; 196 197 struct ep_data { 198 struct mutex lock; 199 enum ep_state state; 200 refcount_t count; 201 struct dev_data *dev; 202 /* must hold dev->lock before accessing ep or req */ 203 struct usb_ep *ep; 204 struct usb_request *req; 205 ssize_t status; 206 char name [16]; 207 struct usb_endpoint_descriptor desc, hs_desc; 208 struct list_head epfiles; 209 wait_queue_head_t wait; 210 struct dentry *dentry; 211 }; 212 213 static inline void get_ep (struct ep_data *data) 214 { 215 refcount_inc (&data->count); 216 } 217 218 static void put_ep (struct ep_data *data) 219 { 220 if (likely (!refcount_dec_and_test (&data->count))) 221 return; 222 put_dev (data->dev); 223 /* needs no more cleanup */ 224 BUG_ON (!list_empty (&data->epfiles)); 225 BUG_ON (waitqueue_active (&data->wait)); 226 kfree (data); 227 } 228 229 /*----------------------------------------------------------------------*/ 230 231 /* most "how to use the hardware" policy choices are in userspace: 232 * mapping endpoint roles (which the driver needs) to the capabilities 233 * which the usb controller has. most of those capabilities are exposed 234 * implicitly, starting with the driver name and then endpoint names. 235 */ 236 237 static const char *CHIP; 238 static DEFINE_MUTEX(sb_mutex); /* Serialize superblock operations */ 239 240 /*----------------------------------------------------------------------*/ 241 242 /* NOTE: don't use dev_printk calls before binding to the gadget 243 * at the end of ep0 configuration, or after unbind. 244 */ 245 246 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */ 247 #define xprintk(d,level,fmt,args...) \ 248 printk(level "%s: " fmt , shortname , ## args) 249 250 #ifdef DEBUG 251 #define DBG(dev,fmt,args...) \ 252 xprintk(dev , KERN_DEBUG , fmt , ## args) 253 #else 254 #define DBG(dev,fmt,args...) \ 255 do { } while (0) 256 #endif /* DEBUG */ 257 258 #ifdef VERBOSE_DEBUG 259 #define VDEBUG DBG 260 #else 261 #define VDEBUG(dev,fmt,args...) \ 262 do { } while (0) 263 #endif /* DEBUG */ 264 265 #define ERROR(dev,fmt,args...) \ 266 xprintk(dev , KERN_ERR , fmt , ## args) 267 #define INFO(dev,fmt,args...) \ 268 xprintk(dev , KERN_INFO , fmt , ## args) 269 270 271 /*----------------------------------------------------------------------*/ 272 273 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso) 274 * 275 * After opening, configure non-control endpoints. Then use normal 276 * stream read() and write() requests; and maybe ioctl() to get more 277 * precise FIFO status when recovering from cancellation. 278 */ 279 280 static void epio_complete (struct usb_ep *ep, struct usb_request *req) 281 { 282 struct ep_data *epdata = ep->driver_data; 283 284 if (!req->context) 285 return; 286 if (req->status) 287 epdata->status = req->status; 288 else 289 epdata->status = req->actual; 290 complete ((struct completion *)req->context); 291 } 292 293 /* tasklock endpoint, returning when it's connected. 294 * still need dev->lock to use epdata->ep. 295 */ 296 static int 297 get_ready_ep (unsigned f_flags, struct ep_data *epdata, bool is_write) 298 { 299 int val; 300 301 if (f_flags & O_NONBLOCK) { 302 if (!mutex_trylock(&epdata->lock)) 303 goto nonblock; 304 if (epdata->state != STATE_EP_ENABLED && 305 (!is_write || epdata->state != STATE_EP_READY)) { 306 mutex_unlock(&epdata->lock); 307 nonblock: 308 val = -EAGAIN; 309 } else 310 val = 0; 311 return val; 312 } 313 314 val = mutex_lock_interruptible(&epdata->lock); 315 if (val < 0) 316 return val; 317 318 switch (epdata->state) { 319 case STATE_EP_ENABLED: 320 return 0; 321 case STATE_EP_READY: /* not configured yet */ 322 if (is_write) 323 return 0; 324 fallthrough; 325 case STATE_EP_UNBOUND: /* clean disconnect */ 326 break; 327 // case STATE_EP_DISABLED: /* "can't happen" */ 328 default: /* error! */ 329 pr_debug ("%s: ep %p not available, state %d\n", 330 shortname, epdata, epdata->state); 331 } 332 mutex_unlock(&epdata->lock); 333 return -ENODEV; 334 } 335 336 static ssize_t 337 ep_io (struct ep_data *epdata, void *buf, unsigned len) 338 { 339 DECLARE_COMPLETION_ONSTACK (done); 340 int value; 341 342 spin_lock_irq (&epdata->dev->lock); 343 if (likely (epdata->ep != NULL)) { 344 struct usb_request *req = epdata->req; 345 346 req->context = &done; 347 req->complete = epio_complete; 348 req->buf = buf; 349 req->length = len; 350 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC); 351 } else 352 value = -ENODEV; 353 spin_unlock_irq (&epdata->dev->lock); 354 355 if (likely (value == 0)) { 356 value = wait_for_completion_interruptible(&done); 357 if (value != 0) { 358 spin_lock_irq (&epdata->dev->lock); 359 if (likely (epdata->ep != NULL)) { 360 DBG (epdata->dev, "%s i/o interrupted\n", 361 epdata->name); 362 usb_ep_dequeue (epdata->ep, epdata->req); 363 spin_unlock_irq (&epdata->dev->lock); 364 365 wait_for_completion(&done); 366 if (epdata->status == -ECONNRESET) 367 epdata->status = -EINTR; 368 } else { 369 spin_unlock_irq (&epdata->dev->lock); 370 371 DBG (epdata->dev, "endpoint gone\n"); 372 wait_for_completion(&done); 373 epdata->status = -ENODEV; 374 } 375 } 376 return epdata->status; 377 } 378 return value; 379 } 380 381 static int 382 ep_release (struct inode *inode, struct file *fd) 383 { 384 struct ep_data *data = fd->private_data; 385 int value; 386 387 value = mutex_lock_interruptible(&data->lock); 388 if (value < 0) 389 return value; 390 391 /* clean up if this can be reopened */ 392 if (data->state != STATE_EP_UNBOUND) { 393 data->state = STATE_EP_DISABLED; 394 data->desc.bDescriptorType = 0; 395 data->hs_desc.bDescriptorType = 0; 396 usb_ep_disable(data->ep); 397 } 398 mutex_unlock(&data->lock); 399 put_ep (data); 400 return 0; 401 } 402 403 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value) 404 { 405 struct ep_data *data = fd->private_data; 406 int status; 407 408 if ((status = get_ready_ep (fd->f_flags, data, false)) < 0) 409 return status; 410 411 spin_lock_irq (&data->dev->lock); 412 if (likely (data->ep != NULL)) { 413 switch (code) { 414 case GADGETFS_FIFO_STATUS: 415 status = usb_ep_fifo_status (data->ep); 416 break; 417 case GADGETFS_FIFO_FLUSH: 418 usb_ep_fifo_flush (data->ep); 419 break; 420 case GADGETFS_CLEAR_HALT: 421 status = usb_ep_clear_halt (data->ep); 422 break; 423 default: 424 status = -ENOTTY; 425 } 426 } else 427 status = -ENODEV; 428 spin_unlock_irq (&data->dev->lock); 429 mutex_unlock(&data->lock); 430 return status; 431 } 432 433 /*----------------------------------------------------------------------*/ 434 435 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */ 436 437 struct kiocb_priv { 438 struct usb_request *req; 439 struct ep_data *epdata; 440 struct kiocb *iocb; 441 struct mm_struct *mm; 442 struct work_struct work; 443 void *buf; 444 struct iov_iter to; 445 const void *to_free; 446 unsigned actual; 447 }; 448 449 static int ep_aio_cancel(struct kiocb *iocb) 450 { 451 struct kiocb_priv *priv = iocb->private; 452 struct ep_data *epdata; 453 int value; 454 455 local_irq_disable(); 456 epdata = priv->epdata; 457 // spin_lock(&epdata->dev->lock); 458 if (likely(epdata && epdata->ep && priv->req)) 459 value = usb_ep_dequeue (epdata->ep, priv->req); 460 else 461 value = -EINVAL; 462 // spin_unlock(&epdata->dev->lock); 463 local_irq_enable(); 464 465 return value; 466 } 467 468 static void ep_user_copy_worker(struct work_struct *work) 469 { 470 struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work); 471 struct mm_struct *mm = priv->mm; 472 struct kiocb *iocb = priv->iocb; 473 size_t ret; 474 475 kthread_use_mm(mm); 476 ret = copy_to_iter(priv->buf, priv->actual, &priv->to); 477 kthread_unuse_mm(mm); 478 if (!ret) 479 ret = -EFAULT; 480 481 /* completing the iocb can drop the ctx and mm, don't touch mm after */ 482 iocb->ki_complete(iocb, ret); 483 484 kfree(priv->buf); 485 kfree(priv->to_free); 486 kfree(priv); 487 } 488 489 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req) 490 { 491 struct kiocb *iocb = req->context; 492 struct kiocb_priv *priv = iocb->private; 493 struct ep_data *epdata = priv->epdata; 494 495 /* lock against disconnect (and ideally, cancel) */ 496 spin_lock(&epdata->dev->lock); 497 priv->req = NULL; 498 priv->epdata = NULL; 499 500 /* if this was a write or a read returning no data then we 501 * don't need to copy anything to userspace, so we can 502 * complete the aio request immediately. 503 */ 504 if (priv->to_free == NULL || unlikely(req->actual == 0)) { 505 kfree(req->buf); 506 kfree(priv->to_free); 507 kfree(priv); 508 iocb->private = NULL; 509 iocb->ki_complete(iocb, 510 req->actual ? req->actual : (long)req->status); 511 } else { 512 /* ep_copy_to_user() won't report both; we hide some faults */ 513 if (unlikely(0 != req->status)) 514 DBG(epdata->dev, "%s fault %d len %d\n", 515 ep->name, req->status, req->actual); 516 517 priv->buf = req->buf; 518 priv->actual = req->actual; 519 INIT_WORK(&priv->work, ep_user_copy_worker); 520 schedule_work(&priv->work); 521 } 522 523 usb_ep_free_request(ep, req); 524 spin_unlock(&epdata->dev->lock); 525 put_ep(epdata); 526 } 527 528 static ssize_t ep_aio(struct kiocb *iocb, 529 struct kiocb_priv *priv, 530 struct ep_data *epdata, 531 char *buf, 532 size_t len) 533 { 534 struct usb_request *req; 535 ssize_t value; 536 537 iocb->private = priv; 538 priv->iocb = iocb; 539 540 kiocb_set_cancel_fn(iocb, ep_aio_cancel); 541 get_ep(epdata); 542 priv->epdata = epdata; 543 priv->actual = 0; 544 priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */ 545 546 /* each kiocb is coupled to one usb_request, but we can't 547 * allocate or submit those if the host disconnected. 548 */ 549 spin_lock_irq(&epdata->dev->lock); 550 value = -ENODEV; 551 if (unlikely(epdata->ep == NULL)) 552 goto fail; 553 554 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC); 555 value = -ENOMEM; 556 if (unlikely(!req)) 557 goto fail; 558 559 priv->req = req; 560 req->buf = buf; 561 req->length = len; 562 req->complete = ep_aio_complete; 563 req->context = iocb; 564 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC); 565 if (unlikely(0 != value)) { 566 usb_ep_free_request(epdata->ep, req); 567 goto fail; 568 } 569 spin_unlock_irq(&epdata->dev->lock); 570 return -EIOCBQUEUED; 571 572 fail: 573 spin_unlock_irq(&epdata->dev->lock); 574 kfree(priv->to_free); 575 kfree(priv); 576 put_ep(epdata); 577 return value; 578 } 579 580 static ssize_t 581 ep_read_iter(struct kiocb *iocb, struct iov_iter *to) 582 { 583 struct file *file = iocb->ki_filp; 584 struct ep_data *epdata = file->private_data; 585 size_t len = iov_iter_count(to); 586 ssize_t value; 587 char *buf; 588 589 if ((value = get_ready_ep(file->f_flags, epdata, false)) < 0) 590 return value; 591 592 /* halt any endpoint by doing a "wrong direction" i/o call */ 593 if (usb_endpoint_dir_in(&epdata->desc)) { 594 if (usb_endpoint_xfer_isoc(&epdata->desc) || 595 !is_sync_kiocb(iocb)) { 596 mutex_unlock(&epdata->lock); 597 return -EINVAL; 598 } 599 DBG (epdata->dev, "%s halt\n", epdata->name); 600 spin_lock_irq(&epdata->dev->lock); 601 if (likely(epdata->ep != NULL)) 602 usb_ep_set_halt(epdata->ep); 603 spin_unlock_irq(&epdata->dev->lock); 604 mutex_unlock(&epdata->lock); 605 return -EBADMSG; 606 } 607 608 buf = kmalloc(len, GFP_KERNEL); 609 if (unlikely(!buf)) { 610 mutex_unlock(&epdata->lock); 611 return -ENOMEM; 612 } 613 if (is_sync_kiocb(iocb)) { 614 value = ep_io(epdata, buf, len); 615 if (value >= 0 && (copy_to_iter(buf, value, to) != value)) 616 value = -EFAULT; 617 } else { 618 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL); 619 value = -ENOMEM; 620 if (!priv) 621 goto fail; 622 priv->to_free = dup_iter(&priv->to, to, GFP_KERNEL); 623 if (!iter_is_ubuf(&priv->to) && !priv->to_free) { 624 kfree(priv); 625 goto fail; 626 } 627 value = ep_aio(iocb, priv, epdata, buf, len); 628 if (value == -EIOCBQUEUED) 629 buf = NULL; 630 } 631 fail: 632 kfree(buf); 633 mutex_unlock(&epdata->lock); 634 return value; 635 } 636 637 static ssize_t ep_config(struct ep_data *, const char *, size_t); 638 639 static ssize_t 640 ep_write_iter(struct kiocb *iocb, struct iov_iter *from) 641 { 642 struct file *file = iocb->ki_filp; 643 struct ep_data *epdata = file->private_data; 644 size_t len = iov_iter_count(from); 645 bool configured; 646 ssize_t value; 647 char *buf; 648 649 if ((value = get_ready_ep(file->f_flags, epdata, true)) < 0) 650 return value; 651 652 configured = epdata->state == STATE_EP_ENABLED; 653 654 /* halt any endpoint by doing a "wrong direction" i/o call */ 655 if (configured && !usb_endpoint_dir_in(&epdata->desc)) { 656 if (usb_endpoint_xfer_isoc(&epdata->desc) || 657 !is_sync_kiocb(iocb)) { 658 mutex_unlock(&epdata->lock); 659 return -EINVAL; 660 } 661 DBG (epdata->dev, "%s halt\n", epdata->name); 662 spin_lock_irq(&epdata->dev->lock); 663 if (likely(epdata->ep != NULL)) 664 usb_ep_set_halt(epdata->ep); 665 spin_unlock_irq(&epdata->dev->lock); 666 mutex_unlock(&epdata->lock); 667 return -EBADMSG; 668 } 669 670 buf = kmalloc(len, GFP_KERNEL); 671 if (unlikely(!buf)) { 672 mutex_unlock(&epdata->lock); 673 return -ENOMEM; 674 } 675 676 if (unlikely(!copy_from_iter_full(buf, len, from))) { 677 value = -EFAULT; 678 goto out; 679 } 680 681 if (unlikely(!configured)) { 682 value = ep_config(epdata, buf, len); 683 } else if (is_sync_kiocb(iocb)) { 684 value = ep_io(epdata, buf, len); 685 } else { 686 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL); 687 value = -ENOMEM; 688 if (priv) { 689 value = ep_aio(iocb, priv, epdata, buf, len); 690 if (value == -EIOCBQUEUED) 691 buf = NULL; 692 } 693 } 694 out: 695 kfree(buf); 696 mutex_unlock(&epdata->lock); 697 return value; 698 } 699 700 /*----------------------------------------------------------------------*/ 701 702 /* used after endpoint configuration */ 703 static const struct file_operations ep_io_operations = { 704 .owner = THIS_MODULE, 705 706 .open = ep_open, 707 .release = ep_release, 708 .llseek = no_llseek, 709 .unlocked_ioctl = ep_ioctl, 710 .read_iter = ep_read_iter, 711 .write_iter = ep_write_iter, 712 }; 713 714 /* ENDPOINT INITIALIZATION 715 * 716 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR) 717 * status = write (fd, descriptors, sizeof descriptors) 718 * 719 * That write establishes the endpoint configuration, configuring 720 * the controller to process bulk, interrupt, or isochronous transfers 721 * at the right maxpacket size, and so on. 722 * 723 * The descriptors are message type 1, identified by a host order u32 724 * at the beginning of what's written. Descriptor order is: full/low 725 * speed descriptor, then optional high speed descriptor. 726 */ 727 static ssize_t 728 ep_config (struct ep_data *data, const char *buf, size_t len) 729 { 730 struct usb_ep *ep; 731 u32 tag; 732 int value, length = len; 733 734 if (data->state != STATE_EP_READY) { 735 value = -EL2HLT; 736 goto fail; 737 } 738 739 value = len; 740 if (len < USB_DT_ENDPOINT_SIZE + 4) 741 goto fail0; 742 743 /* we might need to change message format someday */ 744 memcpy(&tag, buf, 4); 745 if (tag != 1) { 746 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag); 747 goto fail0; 748 } 749 buf += 4; 750 len -= 4; 751 752 /* NOTE: audio endpoint extensions not accepted here; 753 * just don't include the extra bytes. 754 */ 755 756 /* full/low speed descriptor, then high speed */ 757 memcpy(&data->desc, buf, USB_DT_ENDPOINT_SIZE); 758 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE 759 || data->desc.bDescriptorType != USB_DT_ENDPOINT) 760 goto fail0; 761 if (len != USB_DT_ENDPOINT_SIZE) { 762 if (len != 2 * USB_DT_ENDPOINT_SIZE) 763 goto fail0; 764 memcpy(&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE, 765 USB_DT_ENDPOINT_SIZE); 766 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE 767 || data->hs_desc.bDescriptorType 768 != USB_DT_ENDPOINT) { 769 DBG(data->dev, "config %s, bad hs length or type\n", 770 data->name); 771 goto fail0; 772 } 773 } 774 775 spin_lock_irq (&data->dev->lock); 776 if (data->dev->state == STATE_DEV_UNBOUND) { 777 value = -ENOENT; 778 goto gone; 779 } else { 780 ep = data->ep; 781 if (ep == NULL) { 782 value = -ENODEV; 783 goto gone; 784 } 785 } 786 switch (data->dev->gadget->speed) { 787 case USB_SPEED_LOW: 788 case USB_SPEED_FULL: 789 ep->desc = &data->desc; 790 break; 791 case USB_SPEED_HIGH: 792 /* fails if caller didn't provide that descriptor... */ 793 ep->desc = &data->hs_desc; 794 break; 795 default: 796 DBG(data->dev, "unconnected, %s init abandoned\n", 797 data->name); 798 value = -EINVAL; 799 goto gone; 800 } 801 value = usb_ep_enable(ep); 802 if (value == 0) { 803 data->state = STATE_EP_ENABLED; 804 value = length; 805 } 806 gone: 807 spin_unlock_irq (&data->dev->lock); 808 if (value < 0) { 809 fail: 810 data->desc.bDescriptorType = 0; 811 data->hs_desc.bDescriptorType = 0; 812 } 813 return value; 814 fail0: 815 value = -EINVAL; 816 goto fail; 817 } 818 819 static int 820 ep_open (struct inode *inode, struct file *fd) 821 { 822 struct ep_data *data = inode->i_private; 823 int value = -EBUSY; 824 825 if (mutex_lock_interruptible(&data->lock) != 0) 826 return -EINTR; 827 spin_lock_irq (&data->dev->lock); 828 if (data->dev->state == STATE_DEV_UNBOUND) 829 value = -ENOENT; 830 else if (data->state == STATE_EP_DISABLED) { 831 value = 0; 832 data->state = STATE_EP_READY; 833 get_ep (data); 834 fd->private_data = data; 835 VDEBUG (data->dev, "%s ready\n", data->name); 836 } else 837 DBG (data->dev, "%s state %d\n", 838 data->name, data->state); 839 spin_unlock_irq (&data->dev->lock); 840 mutex_unlock(&data->lock); 841 return value; 842 } 843 844 /*----------------------------------------------------------------------*/ 845 846 /* EP0 IMPLEMENTATION can be partly in userspace. 847 * 848 * Drivers that use this facility receive various events, including 849 * control requests the kernel doesn't handle. Drivers that don't 850 * use this facility may be too simple-minded for real applications. 851 */ 852 853 static inline void ep0_readable (struct dev_data *dev) 854 { 855 wake_up (&dev->wait); 856 kill_fasync (&dev->fasync, SIGIO, POLL_IN); 857 } 858 859 static void clean_req (struct usb_ep *ep, struct usb_request *req) 860 { 861 struct dev_data *dev = ep->driver_data; 862 863 if (req->buf != dev->rbuf) { 864 kfree(req->buf); 865 req->buf = dev->rbuf; 866 } 867 req->complete = epio_complete; 868 dev->setup_out_ready = 0; 869 } 870 871 static void ep0_complete (struct usb_ep *ep, struct usb_request *req) 872 { 873 struct dev_data *dev = ep->driver_data; 874 unsigned long flags; 875 int free = 1; 876 877 /* for control OUT, data must still get to userspace */ 878 spin_lock_irqsave(&dev->lock, flags); 879 if (!dev->setup_in) { 880 dev->setup_out_error = (req->status != 0); 881 if (!dev->setup_out_error) 882 free = 0; 883 dev->setup_out_ready = 1; 884 ep0_readable (dev); 885 } 886 887 /* clean up as appropriate */ 888 if (free && req->buf != &dev->rbuf) 889 clean_req (ep, req); 890 req->complete = epio_complete; 891 spin_unlock_irqrestore(&dev->lock, flags); 892 } 893 894 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len) 895 { 896 struct dev_data *dev = ep->driver_data; 897 898 if (dev->setup_out_ready) { 899 DBG (dev, "ep0 request busy!\n"); 900 return -EBUSY; 901 } 902 if (len > sizeof (dev->rbuf)) 903 req->buf = kmalloc(len, GFP_ATOMIC); 904 if (req->buf == NULL) { 905 req->buf = dev->rbuf; 906 return -ENOMEM; 907 } 908 req->complete = ep0_complete; 909 req->length = len; 910 req->zero = 0; 911 return 0; 912 } 913 914 static ssize_t 915 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr) 916 { 917 struct dev_data *dev = fd->private_data; 918 ssize_t retval; 919 enum ep0_state state; 920 921 spin_lock_irq (&dev->lock); 922 if (dev->state <= STATE_DEV_OPENED) { 923 retval = -EINVAL; 924 goto done; 925 } 926 927 /* report fd mode change before acting on it */ 928 if (dev->setup_abort) { 929 dev->setup_abort = 0; 930 retval = -EIDRM; 931 goto done; 932 } 933 934 /* control DATA stage */ 935 if ((state = dev->state) == STATE_DEV_SETUP) { 936 937 if (dev->setup_in) { /* stall IN */ 938 VDEBUG(dev, "ep0in stall\n"); 939 (void) usb_ep_set_halt (dev->gadget->ep0); 940 retval = -EL2HLT; 941 dev->state = STATE_DEV_CONNECTED; 942 943 } else if (len == 0) { /* ack SET_CONFIGURATION etc */ 944 struct usb_ep *ep = dev->gadget->ep0; 945 struct usb_request *req = dev->req; 946 947 if ((retval = setup_req (ep, req, 0)) == 0) { 948 ++dev->udc_usage; 949 spin_unlock_irq (&dev->lock); 950 retval = usb_ep_queue (ep, req, GFP_KERNEL); 951 spin_lock_irq (&dev->lock); 952 --dev->udc_usage; 953 } 954 dev->state = STATE_DEV_CONNECTED; 955 956 /* assume that was SET_CONFIGURATION */ 957 if (dev->current_config) { 958 unsigned power; 959 960 if (gadget_is_dualspeed(dev->gadget) 961 && (dev->gadget->speed 962 == USB_SPEED_HIGH)) 963 power = dev->hs_config->bMaxPower; 964 else 965 power = dev->config->bMaxPower; 966 usb_gadget_vbus_draw(dev->gadget, 2 * power); 967 } 968 969 } else { /* collect OUT data */ 970 if ((fd->f_flags & O_NONBLOCK) != 0 971 && !dev->setup_out_ready) { 972 retval = -EAGAIN; 973 goto done; 974 } 975 spin_unlock_irq (&dev->lock); 976 retval = wait_event_interruptible (dev->wait, 977 dev->setup_out_ready != 0); 978 979 /* FIXME state could change from under us */ 980 spin_lock_irq (&dev->lock); 981 if (retval) 982 goto done; 983 984 if (dev->state != STATE_DEV_SETUP) { 985 retval = -ECANCELED; 986 goto done; 987 } 988 dev->state = STATE_DEV_CONNECTED; 989 990 if (dev->setup_out_error) 991 retval = -EIO; 992 else { 993 len = min (len, (size_t)dev->req->actual); 994 ++dev->udc_usage; 995 spin_unlock_irq(&dev->lock); 996 if (copy_to_user (buf, dev->req->buf, len)) 997 retval = -EFAULT; 998 else 999 retval = len; 1000 spin_lock_irq(&dev->lock); 1001 --dev->udc_usage; 1002 clean_req (dev->gadget->ep0, dev->req); 1003 /* NOTE userspace can't yet choose to stall */ 1004 } 1005 } 1006 goto done; 1007 } 1008 1009 /* else normal: return event data */ 1010 if (len < sizeof dev->event [0]) { 1011 retval = -EINVAL; 1012 goto done; 1013 } 1014 len -= len % sizeof (struct usb_gadgetfs_event); 1015 dev->usermode_setup = 1; 1016 1017 scan: 1018 /* return queued events right away */ 1019 if (dev->ev_next != 0) { 1020 unsigned i, n; 1021 1022 n = len / sizeof (struct usb_gadgetfs_event); 1023 if (dev->ev_next < n) 1024 n = dev->ev_next; 1025 1026 /* ep0 i/o has special semantics during STATE_DEV_SETUP */ 1027 for (i = 0; i < n; i++) { 1028 if (dev->event [i].type == GADGETFS_SETUP) { 1029 dev->state = STATE_DEV_SETUP; 1030 n = i + 1; 1031 break; 1032 } 1033 } 1034 spin_unlock_irq (&dev->lock); 1035 len = n * sizeof (struct usb_gadgetfs_event); 1036 if (copy_to_user (buf, &dev->event, len)) 1037 retval = -EFAULT; 1038 else 1039 retval = len; 1040 if (len > 0) { 1041 /* NOTE this doesn't guard against broken drivers; 1042 * concurrent ep0 readers may lose events. 1043 */ 1044 spin_lock_irq (&dev->lock); 1045 if (dev->ev_next > n) { 1046 memmove(&dev->event[0], &dev->event[n], 1047 sizeof (struct usb_gadgetfs_event) 1048 * (dev->ev_next - n)); 1049 } 1050 dev->ev_next -= n; 1051 spin_unlock_irq (&dev->lock); 1052 } 1053 return retval; 1054 } 1055 if (fd->f_flags & O_NONBLOCK) { 1056 retval = -EAGAIN; 1057 goto done; 1058 } 1059 1060 switch (state) { 1061 default: 1062 DBG (dev, "fail %s, state %d\n", __func__, state); 1063 retval = -ESRCH; 1064 break; 1065 case STATE_DEV_UNCONNECTED: 1066 case STATE_DEV_CONNECTED: 1067 spin_unlock_irq (&dev->lock); 1068 DBG (dev, "%s wait\n", __func__); 1069 1070 /* wait for events */ 1071 retval = wait_event_interruptible (dev->wait, 1072 dev->ev_next != 0); 1073 if (retval < 0) 1074 return retval; 1075 spin_lock_irq (&dev->lock); 1076 goto scan; 1077 } 1078 1079 done: 1080 spin_unlock_irq (&dev->lock); 1081 return retval; 1082 } 1083 1084 static struct usb_gadgetfs_event * 1085 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type) 1086 { 1087 struct usb_gadgetfs_event *event; 1088 unsigned i; 1089 1090 switch (type) { 1091 /* these events purge the queue */ 1092 case GADGETFS_DISCONNECT: 1093 if (dev->state == STATE_DEV_SETUP) 1094 dev->setup_abort = 1; 1095 fallthrough; 1096 case GADGETFS_CONNECT: 1097 dev->ev_next = 0; 1098 break; 1099 case GADGETFS_SETUP: /* previous request timed out */ 1100 case GADGETFS_SUSPEND: /* same effect */ 1101 /* these events can't be repeated */ 1102 for (i = 0; i != dev->ev_next; i++) { 1103 if (dev->event [i].type != type) 1104 continue; 1105 DBG(dev, "discard old event[%d] %d\n", i, type); 1106 dev->ev_next--; 1107 if (i == dev->ev_next) 1108 break; 1109 /* indices start at zero, for simplicity */ 1110 memmove (&dev->event [i], &dev->event [i + 1], 1111 sizeof (struct usb_gadgetfs_event) 1112 * (dev->ev_next - i)); 1113 } 1114 break; 1115 default: 1116 BUG (); 1117 } 1118 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type); 1119 event = &dev->event [dev->ev_next++]; 1120 BUG_ON (dev->ev_next > N_EVENT); 1121 memset (event, 0, sizeof *event); 1122 event->type = type; 1123 return event; 1124 } 1125 1126 static ssize_t 1127 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1128 { 1129 struct dev_data *dev = fd->private_data; 1130 ssize_t retval = -ESRCH; 1131 1132 /* report fd mode change before acting on it */ 1133 if (dev->setup_abort) { 1134 dev->setup_abort = 0; 1135 retval = -EIDRM; 1136 1137 /* data and/or status stage for control request */ 1138 } else if (dev->state == STATE_DEV_SETUP) { 1139 1140 len = min_t(size_t, len, dev->setup_wLength); 1141 if (dev->setup_in) { 1142 retval = setup_req (dev->gadget->ep0, dev->req, len); 1143 if (retval == 0) { 1144 dev->state = STATE_DEV_CONNECTED; 1145 ++dev->udc_usage; 1146 spin_unlock_irq (&dev->lock); 1147 if (copy_from_user (dev->req->buf, buf, len)) 1148 retval = -EFAULT; 1149 else { 1150 if (len < dev->setup_wLength) 1151 dev->req->zero = 1; 1152 retval = usb_ep_queue ( 1153 dev->gadget->ep0, dev->req, 1154 GFP_KERNEL); 1155 } 1156 spin_lock_irq(&dev->lock); 1157 --dev->udc_usage; 1158 if (retval < 0) { 1159 clean_req (dev->gadget->ep0, dev->req); 1160 } else 1161 retval = len; 1162 1163 return retval; 1164 } 1165 1166 /* can stall some OUT transfers */ 1167 } else if (dev->setup_can_stall) { 1168 VDEBUG(dev, "ep0out stall\n"); 1169 (void) usb_ep_set_halt (dev->gadget->ep0); 1170 retval = -EL2HLT; 1171 dev->state = STATE_DEV_CONNECTED; 1172 } else { 1173 DBG(dev, "bogus ep0out stall!\n"); 1174 } 1175 } else 1176 DBG (dev, "fail %s, state %d\n", __func__, dev->state); 1177 1178 return retval; 1179 } 1180 1181 static int 1182 ep0_fasync (int f, struct file *fd, int on) 1183 { 1184 struct dev_data *dev = fd->private_data; 1185 // caller must F_SETOWN before signal delivery happens 1186 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off"); 1187 return fasync_helper (f, fd, on, &dev->fasync); 1188 } 1189 1190 static struct usb_gadget_driver gadgetfs_driver; 1191 1192 static int 1193 dev_release (struct inode *inode, struct file *fd) 1194 { 1195 struct dev_data *dev = fd->private_data; 1196 1197 /* closing ep0 === shutdown all */ 1198 1199 if (dev->gadget_registered) { 1200 usb_gadget_unregister_driver (&gadgetfs_driver); 1201 dev->gadget_registered = false; 1202 } 1203 1204 /* at this point "good" hardware has disconnected the 1205 * device from USB; the host won't see it any more. 1206 * alternatively, all host requests will time out. 1207 */ 1208 1209 kfree (dev->buf); 1210 dev->buf = NULL; 1211 1212 /* other endpoints were all decoupled from this device */ 1213 spin_lock_irq(&dev->lock); 1214 dev->state = STATE_DEV_DISABLED; 1215 spin_unlock_irq(&dev->lock); 1216 1217 put_dev (dev); 1218 return 0; 1219 } 1220 1221 static __poll_t 1222 ep0_poll (struct file *fd, poll_table *wait) 1223 { 1224 struct dev_data *dev = fd->private_data; 1225 __poll_t mask = 0; 1226 1227 if (dev->state <= STATE_DEV_OPENED) 1228 return DEFAULT_POLLMASK; 1229 1230 poll_wait(fd, &dev->wait, wait); 1231 1232 spin_lock_irq(&dev->lock); 1233 1234 /* report fd mode change before acting on it */ 1235 if (dev->setup_abort) { 1236 dev->setup_abort = 0; 1237 mask = EPOLLHUP; 1238 goto out; 1239 } 1240 1241 if (dev->state == STATE_DEV_SETUP) { 1242 if (dev->setup_in || dev->setup_can_stall) 1243 mask = EPOLLOUT; 1244 } else { 1245 if (dev->ev_next != 0) 1246 mask = EPOLLIN; 1247 } 1248 out: 1249 spin_unlock_irq(&dev->lock); 1250 return mask; 1251 } 1252 1253 static long gadget_dev_ioctl (struct file *fd, unsigned code, unsigned long value) 1254 { 1255 struct dev_data *dev = fd->private_data; 1256 struct usb_gadget *gadget = dev->gadget; 1257 long ret = -ENOTTY; 1258 1259 spin_lock_irq(&dev->lock); 1260 if (dev->state == STATE_DEV_OPENED || 1261 dev->state == STATE_DEV_UNBOUND) { 1262 /* Not bound to a UDC */ 1263 } else if (gadget->ops->ioctl) { 1264 ++dev->udc_usage; 1265 spin_unlock_irq(&dev->lock); 1266 1267 ret = gadget->ops->ioctl (gadget, code, value); 1268 1269 spin_lock_irq(&dev->lock); 1270 --dev->udc_usage; 1271 } 1272 spin_unlock_irq(&dev->lock); 1273 1274 return ret; 1275 } 1276 1277 /*----------------------------------------------------------------------*/ 1278 1279 /* The in-kernel gadget driver handles most ep0 issues, in particular 1280 * enumerating the single configuration (as provided from user space). 1281 * 1282 * Unrecognized ep0 requests may be handled in user space. 1283 */ 1284 1285 static void make_qualifier (struct dev_data *dev) 1286 { 1287 struct usb_qualifier_descriptor qual; 1288 struct usb_device_descriptor *desc; 1289 1290 qual.bLength = sizeof qual; 1291 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER; 1292 qual.bcdUSB = cpu_to_le16 (0x0200); 1293 1294 desc = dev->dev; 1295 qual.bDeviceClass = desc->bDeviceClass; 1296 qual.bDeviceSubClass = desc->bDeviceSubClass; 1297 qual.bDeviceProtocol = desc->bDeviceProtocol; 1298 1299 /* assumes ep0 uses the same value for both speeds ... */ 1300 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket; 1301 1302 qual.bNumConfigurations = 1; 1303 qual.bRESERVED = 0; 1304 1305 memcpy (dev->rbuf, &qual, sizeof qual); 1306 } 1307 1308 static int 1309 config_buf (struct dev_data *dev, u8 type, unsigned index) 1310 { 1311 int len; 1312 int hs = 0; 1313 1314 /* only one configuration */ 1315 if (index > 0) 1316 return -EINVAL; 1317 1318 if (gadget_is_dualspeed(dev->gadget)) { 1319 hs = (dev->gadget->speed == USB_SPEED_HIGH); 1320 if (type == USB_DT_OTHER_SPEED_CONFIG) 1321 hs = !hs; 1322 } 1323 if (hs) { 1324 dev->req->buf = dev->hs_config; 1325 len = le16_to_cpu(dev->hs_config->wTotalLength); 1326 } else { 1327 dev->req->buf = dev->config; 1328 len = le16_to_cpu(dev->config->wTotalLength); 1329 } 1330 ((u8 *)dev->req->buf) [1] = type; 1331 return len; 1332 } 1333 1334 static int 1335 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) 1336 { 1337 struct dev_data *dev = get_gadget_data (gadget); 1338 struct usb_request *req = dev->req; 1339 int value = -EOPNOTSUPP; 1340 struct usb_gadgetfs_event *event; 1341 u16 w_value = le16_to_cpu(ctrl->wValue); 1342 u16 w_length = le16_to_cpu(ctrl->wLength); 1343 1344 if (w_length > RBUF_SIZE) { 1345 if (ctrl->bRequestType & USB_DIR_IN) { 1346 /* Cast away the const, we are going to overwrite on purpose. */ 1347 __le16 *temp = (__le16 *)&ctrl->wLength; 1348 1349 *temp = cpu_to_le16(RBUF_SIZE); 1350 w_length = RBUF_SIZE; 1351 } else { 1352 return value; 1353 } 1354 } 1355 1356 spin_lock (&dev->lock); 1357 dev->setup_abort = 0; 1358 if (dev->state == STATE_DEV_UNCONNECTED) { 1359 if (gadget_is_dualspeed(gadget) 1360 && gadget->speed == USB_SPEED_HIGH 1361 && dev->hs_config == NULL) { 1362 spin_unlock(&dev->lock); 1363 ERROR (dev, "no high speed config??\n"); 1364 return -EINVAL; 1365 } 1366 1367 dev->state = STATE_DEV_CONNECTED; 1368 1369 INFO (dev, "connected\n"); 1370 event = next_event (dev, GADGETFS_CONNECT); 1371 event->u.speed = gadget->speed; 1372 ep0_readable (dev); 1373 1374 /* host may have given up waiting for response. we can miss control 1375 * requests handled lower down (device/endpoint status and features); 1376 * then ep0_{read,write} will report the wrong status. controller 1377 * driver will have aborted pending i/o. 1378 */ 1379 } else if (dev->state == STATE_DEV_SETUP) 1380 dev->setup_abort = 1; 1381 1382 req->buf = dev->rbuf; 1383 req->context = NULL; 1384 switch (ctrl->bRequest) { 1385 1386 case USB_REQ_GET_DESCRIPTOR: 1387 if (ctrl->bRequestType != USB_DIR_IN) 1388 goto unrecognized; 1389 switch (w_value >> 8) { 1390 1391 case USB_DT_DEVICE: 1392 value = min (w_length, (u16) sizeof *dev->dev); 1393 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket; 1394 req->buf = dev->dev; 1395 break; 1396 case USB_DT_DEVICE_QUALIFIER: 1397 if (!dev->hs_config) 1398 break; 1399 value = min (w_length, (u16) 1400 sizeof (struct usb_qualifier_descriptor)); 1401 make_qualifier (dev); 1402 break; 1403 case USB_DT_OTHER_SPEED_CONFIG: 1404 case USB_DT_CONFIG: 1405 value = config_buf (dev, 1406 w_value >> 8, 1407 w_value & 0xff); 1408 if (value >= 0) 1409 value = min (w_length, (u16) value); 1410 break; 1411 case USB_DT_STRING: 1412 goto unrecognized; 1413 1414 default: // all others are errors 1415 break; 1416 } 1417 break; 1418 1419 /* currently one config, two speeds */ 1420 case USB_REQ_SET_CONFIGURATION: 1421 if (ctrl->bRequestType != 0) 1422 goto unrecognized; 1423 if (0 == (u8) w_value) { 1424 value = 0; 1425 dev->current_config = 0; 1426 usb_gadget_vbus_draw(gadget, 8 /* mA */ ); 1427 // user mode expected to disable endpoints 1428 } else { 1429 u8 config, power; 1430 1431 if (gadget_is_dualspeed(gadget) 1432 && gadget->speed == USB_SPEED_HIGH) { 1433 config = dev->hs_config->bConfigurationValue; 1434 power = dev->hs_config->bMaxPower; 1435 } else { 1436 config = dev->config->bConfigurationValue; 1437 power = dev->config->bMaxPower; 1438 } 1439 1440 if (config == (u8) w_value) { 1441 value = 0; 1442 dev->current_config = config; 1443 usb_gadget_vbus_draw(gadget, 2 * power); 1444 } 1445 } 1446 1447 /* report SET_CONFIGURATION like any other control request, 1448 * except that usermode may not stall this. the next 1449 * request mustn't be allowed start until this finishes: 1450 * endpoints and threads set up, etc. 1451 * 1452 * NOTE: older PXA hardware (before PXA 255: without UDCCFR) 1453 * has bad/racey automagic that prevents synchronizing here. 1454 * even kernel mode drivers often miss them. 1455 */ 1456 if (value == 0) { 1457 INFO (dev, "configuration #%d\n", dev->current_config); 1458 usb_gadget_set_state(gadget, USB_STATE_CONFIGURED); 1459 if (dev->usermode_setup) { 1460 dev->setup_can_stall = 0; 1461 goto delegate; 1462 } 1463 } 1464 break; 1465 1466 #ifndef CONFIG_USB_PXA25X 1467 /* PXA automagically handles this request too */ 1468 case USB_REQ_GET_CONFIGURATION: 1469 if (ctrl->bRequestType != 0x80) 1470 goto unrecognized; 1471 *(u8 *)req->buf = dev->current_config; 1472 value = min (w_length, (u16) 1); 1473 break; 1474 #endif 1475 1476 default: 1477 unrecognized: 1478 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n", 1479 dev->usermode_setup ? "delegate" : "fail", 1480 ctrl->bRequestType, ctrl->bRequest, 1481 w_value, le16_to_cpu(ctrl->wIndex), w_length); 1482 1483 /* if there's an ep0 reader, don't stall */ 1484 if (dev->usermode_setup) { 1485 dev->setup_can_stall = 1; 1486 delegate: 1487 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN) 1488 ? 1 : 0; 1489 dev->setup_wLength = w_length; 1490 dev->setup_out_ready = 0; 1491 dev->setup_out_error = 0; 1492 1493 /* read DATA stage for OUT right away */ 1494 if (unlikely (!dev->setup_in && w_length)) { 1495 value = setup_req (gadget->ep0, dev->req, 1496 w_length); 1497 if (value < 0) 1498 break; 1499 1500 ++dev->udc_usage; 1501 spin_unlock (&dev->lock); 1502 value = usb_ep_queue (gadget->ep0, dev->req, 1503 GFP_KERNEL); 1504 spin_lock (&dev->lock); 1505 --dev->udc_usage; 1506 if (value < 0) { 1507 clean_req (gadget->ep0, dev->req); 1508 break; 1509 } 1510 1511 /* we can't currently stall these */ 1512 dev->setup_can_stall = 0; 1513 } 1514 1515 /* state changes when reader collects event */ 1516 event = next_event (dev, GADGETFS_SETUP); 1517 event->u.setup = *ctrl; 1518 ep0_readable (dev); 1519 spin_unlock (&dev->lock); 1520 /* 1521 * Return USB_GADGET_DELAYED_STATUS as a workaround to 1522 * stop some UDC drivers (e.g. dwc3) from automatically 1523 * proceeding with the status stage for 0-length 1524 * transfers. 1525 * Should be removed once all UDC drivers are fixed to 1526 * always delay the status stage until a response is 1527 * queued to EP0. 1528 */ 1529 return w_length == 0 ? USB_GADGET_DELAYED_STATUS : 0; 1530 } 1531 } 1532 1533 /* proceed with data transfer and status phases? */ 1534 if (value >= 0 && dev->state != STATE_DEV_SETUP) { 1535 req->length = value; 1536 req->zero = value < w_length; 1537 1538 ++dev->udc_usage; 1539 spin_unlock (&dev->lock); 1540 value = usb_ep_queue (gadget->ep0, req, GFP_KERNEL); 1541 spin_lock(&dev->lock); 1542 --dev->udc_usage; 1543 spin_unlock(&dev->lock); 1544 if (value < 0) { 1545 DBG (dev, "ep_queue --> %d\n", value); 1546 req->status = 0; 1547 } 1548 return value; 1549 } 1550 1551 /* device stalls when value < 0 */ 1552 spin_unlock (&dev->lock); 1553 return value; 1554 } 1555 1556 static void destroy_ep_files (struct dev_data *dev) 1557 { 1558 DBG (dev, "%s %d\n", __func__, dev->state); 1559 1560 /* dev->state must prevent interference */ 1561 spin_lock_irq (&dev->lock); 1562 while (!list_empty(&dev->epfiles)) { 1563 struct ep_data *ep; 1564 struct inode *parent; 1565 struct dentry *dentry; 1566 1567 /* break link to FS */ 1568 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles); 1569 list_del_init (&ep->epfiles); 1570 spin_unlock_irq (&dev->lock); 1571 1572 dentry = ep->dentry; 1573 ep->dentry = NULL; 1574 parent = d_inode(dentry->d_parent); 1575 1576 /* break link to controller */ 1577 mutex_lock(&ep->lock); 1578 if (ep->state == STATE_EP_ENABLED) 1579 (void) usb_ep_disable (ep->ep); 1580 ep->state = STATE_EP_UNBOUND; 1581 usb_ep_free_request (ep->ep, ep->req); 1582 ep->ep = NULL; 1583 mutex_unlock(&ep->lock); 1584 1585 wake_up (&ep->wait); 1586 put_ep (ep); 1587 1588 /* break link to dcache */ 1589 inode_lock(parent); 1590 d_delete (dentry); 1591 dput (dentry); 1592 inode_unlock(parent); 1593 1594 spin_lock_irq (&dev->lock); 1595 } 1596 spin_unlock_irq (&dev->lock); 1597 } 1598 1599 1600 static struct dentry * 1601 gadgetfs_create_file (struct super_block *sb, char const *name, 1602 void *data, const struct file_operations *fops); 1603 1604 static int activate_ep_files (struct dev_data *dev) 1605 { 1606 struct usb_ep *ep; 1607 struct ep_data *data; 1608 1609 gadget_for_each_ep (ep, dev->gadget) { 1610 1611 data = kzalloc(sizeof(*data), GFP_KERNEL); 1612 if (!data) 1613 goto enomem0; 1614 data->state = STATE_EP_DISABLED; 1615 mutex_init(&data->lock); 1616 init_waitqueue_head (&data->wait); 1617 1618 strncpy (data->name, ep->name, sizeof (data->name) - 1); 1619 refcount_set (&data->count, 1); 1620 data->dev = dev; 1621 get_dev (dev); 1622 1623 data->ep = ep; 1624 ep->driver_data = data; 1625 1626 data->req = usb_ep_alloc_request (ep, GFP_KERNEL); 1627 if (!data->req) 1628 goto enomem1; 1629 1630 data->dentry = gadgetfs_create_file (dev->sb, data->name, 1631 data, &ep_io_operations); 1632 if (!data->dentry) 1633 goto enomem2; 1634 list_add_tail (&data->epfiles, &dev->epfiles); 1635 } 1636 return 0; 1637 1638 enomem2: 1639 usb_ep_free_request (ep, data->req); 1640 enomem1: 1641 put_dev (dev); 1642 kfree (data); 1643 enomem0: 1644 DBG (dev, "%s enomem\n", __func__); 1645 destroy_ep_files (dev); 1646 return -ENOMEM; 1647 } 1648 1649 static void 1650 gadgetfs_unbind (struct usb_gadget *gadget) 1651 { 1652 struct dev_data *dev = get_gadget_data (gadget); 1653 1654 DBG (dev, "%s\n", __func__); 1655 1656 spin_lock_irq (&dev->lock); 1657 dev->state = STATE_DEV_UNBOUND; 1658 while (dev->udc_usage > 0) { 1659 spin_unlock_irq(&dev->lock); 1660 usleep_range(1000, 2000); 1661 spin_lock_irq(&dev->lock); 1662 } 1663 spin_unlock_irq (&dev->lock); 1664 1665 destroy_ep_files (dev); 1666 gadget->ep0->driver_data = NULL; 1667 set_gadget_data (gadget, NULL); 1668 1669 /* we've already been disconnected ... no i/o is active */ 1670 if (dev->req) 1671 usb_ep_free_request (gadget->ep0, dev->req); 1672 DBG (dev, "%s done\n", __func__); 1673 put_dev (dev); 1674 } 1675 1676 static struct dev_data *the_device; 1677 1678 static int gadgetfs_bind(struct usb_gadget *gadget, 1679 struct usb_gadget_driver *driver) 1680 { 1681 struct dev_data *dev = the_device; 1682 1683 if (!dev) 1684 return -ESRCH; 1685 if (0 != strcmp (CHIP, gadget->name)) { 1686 pr_err("%s expected %s controller not %s\n", 1687 shortname, CHIP, gadget->name); 1688 return -ENODEV; 1689 } 1690 1691 set_gadget_data (gadget, dev); 1692 dev->gadget = gadget; 1693 gadget->ep0->driver_data = dev; 1694 1695 /* preallocate control response and buffer */ 1696 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL); 1697 if (!dev->req) 1698 goto enomem; 1699 dev->req->context = NULL; 1700 dev->req->complete = epio_complete; 1701 1702 if (activate_ep_files (dev) < 0) 1703 goto enomem; 1704 1705 INFO (dev, "bound to %s driver\n", gadget->name); 1706 spin_lock_irq(&dev->lock); 1707 dev->state = STATE_DEV_UNCONNECTED; 1708 spin_unlock_irq(&dev->lock); 1709 get_dev (dev); 1710 return 0; 1711 1712 enomem: 1713 gadgetfs_unbind (gadget); 1714 return -ENOMEM; 1715 } 1716 1717 static void 1718 gadgetfs_disconnect (struct usb_gadget *gadget) 1719 { 1720 struct dev_data *dev = get_gadget_data (gadget); 1721 unsigned long flags; 1722 1723 spin_lock_irqsave (&dev->lock, flags); 1724 if (dev->state == STATE_DEV_UNCONNECTED) 1725 goto exit; 1726 dev->state = STATE_DEV_UNCONNECTED; 1727 1728 INFO (dev, "disconnected\n"); 1729 next_event (dev, GADGETFS_DISCONNECT); 1730 ep0_readable (dev); 1731 exit: 1732 spin_unlock_irqrestore (&dev->lock, flags); 1733 } 1734 1735 static void 1736 gadgetfs_suspend (struct usb_gadget *gadget) 1737 { 1738 struct dev_data *dev = get_gadget_data (gadget); 1739 unsigned long flags; 1740 1741 INFO (dev, "suspended from state %d\n", dev->state); 1742 spin_lock_irqsave(&dev->lock, flags); 1743 switch (dev->state) { 1744 case STATE_DEV_SETUP: // VERY odd... host died?? 1745 case STATE_DEV_CONNECTED: 1746 case STATE_DEV_UNCONNECTED: 1747 next_event (dev, GADGETFS_SUSPEND); 1748 ep0_readable (dev); 1749 fallthrough; 1750 default: 1751 break; 1752 } 1753 spin_unlock_irqrestore(&dev->lock, flags); 1754 } 1755 1756 static struct usb_gadget_driver gadgetfs_driver = { 1757 .function = (char *) driver_desc, 1758 .bind = gadgetfs_bind, 1759 .unbind = gadgetfs_unbind, 1760 .setup = gadgetfs_setup, 1761 .reset = gadgetfs_disconnect, 1762 .disconnect = gadgetfs_disconnect, 1763 .suspend = gadgetfs_suspend, 1764 1765 .driver = { 1766 .name = shortname, 1767 }, 1768 }; 1769 1770 /*----------------------------------------------------------------------*/ 1771 /* DEVICE INITIALIZATION 1772 * 1773 * fd = open ("/dev/gadget/$CHIP", O_RDWR) 1774 * status = write (fd, descriptors, sizeof descriptors) 1775 * 1776 * That write establishes the device configuration, so the kernel can 1777 * bind to the controller ... guaranteeing it can handle enumeration 1778 * at all necessary speeds. Descriptor order is: 1779 * 1780 * . message tag (u32, host order) ... for now, must be zero; it 1781 * would change to support features like multi-config devices 1782 * . full/low speed config ... all wTotalLength bytes (with interface, 1783 * class, altsetting, endpoint, and other descriptors) 1784 * . high speed config ... all descriptors, for high speed operation; 1785 * this one's optional except for high-speed hardware 1786 * . device descriptor 1787 * 1788 * Endpoints are not yet enabled. Drivers must wait until device 1789 * configuration and interface altsetting changes create 1790 * the need to configure (or unconfigure) them. 1791 * 1792 * After initialization, the device stays active for as long as that 1793 * $CHIP file is open. Events must then be read from that descriptor, 1794 * such as configuration notifications. 1795 */ 1796 1797 static int is_valid_config(struct usb_config_descriptor *config, 1798 unsigned int total) 1799 { 1800 return config->bDescriptorType == USB_DT_CONFIG 1801 && config->bLength == USB_DT_CONFIG_SIZE 1802 && total >= USB_DT_CONFIG_SIZE 1803 && config->bConfigurationValue != 0 1804 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0 1805 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0; 1806 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */ 1807 /* FIXME check lengths: walk to end */ 1808 } 1809 1810 static ssize_t 1811 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 1812 { 1813 struct dev_data *dev = fd->private_data; 1814 ssize_t value, length = len; 1815 unsigned total; 1816 u32 tag; 1817 char *kbuf; 1818 1819 spin_lock_irq(&dev->lock); 1820 if (dev->state > STATE_DEV_OPENED) { 1821 value = ep0_write(fd, buf, len, ptr); 1822 spin_unlock_irq(&dev->lock); 1823 return value; 1824 } 1825 spin_unlock_irq(&dev->lock); 1826 1827 if ((len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) || 1828 (len > PAGE_SIZE * 4)) 1829 return -EINVAL; 1830 1831 /* we might need to change message format someday */ 1832 if (copy_from_user (&tag, buf, 4)) 1833 return -EFAULT; 1834 if (tag != 0) 1835 return -EINVAL; 1836 buf += 4; 1837 length -= 4; 1838 1839 kbuf = memdup_user(buf, length); 1840 if (IS_ERR(kbuf)) 1841 return PTR_ERR(kbuf); 1842 1843 spin_lock_irq (&dev->lock); 1844 value = -EINVAL; 1845 if (dev->buf) { 1846 spin_unlock_irq(&dev->lock); 1847 kfree(kbuf); 1848 return value; 1849 } 1850 dev->buf = kbuf; 1851 1852 /* full or low speed config */ 1853 dev->config = (void *) kbuf; 1854 total = le16_to_cpu(dev->config->wTotalLength); 1855 if (!is_valid_config(dev->config, total) || 1856 total > length - USB_DT_DEVICE_SIZE) 1857 goto fail; 1858 kbuf += total; 1859 length -= total; 1860 1861 /* optional high speed config */ 1862 if (kbuf [1] == USB_DT_CONFIG) { 1863 dev->hs_config = (void *) kbuf; 1864 total = le16_to_cpu(dev->hs_config->wTotalLength); 1865 if (!is_valid_config(dev->hs_config, total) || 1866 total > length - USB_DT_DEVICE_SIZE) 1867 goto fail; 1868 kbuf += total; 1869 length -= total; 1870 } else { 1871 dev->hs_config = NULL; 1872 } 1873 1874 /* could support multiple configs, using another encoding! */ 1875 1876 /* device descriptor (tweaked for paranoia) */ 1877 if (length != USB_DT_DEVICE_SIZE) 1878 goto fail; 1879 dev->dev = (void *)kbuf; 1880 if (dev->dev->bLength != USB_DT_DEVICE_SIZE 1881 || dev->dev->bDescriptorType != USB_DT_DEVICE 1882 || dev->dev->bNumConfigurations != 1) 1883 goto fail; 1884 dev->dev->bcdUSB = cpu_to_le16 (0x0200); 1885 1886 /* triggers gadgetfs_bind(); then we can enumerate. */ 1887 spin_unlock_irq (&dev->lock); 1888 if (dev->hs_config) 1889 gadgetfs_driver.max_speed = USB_SPEED_HIGH; 1890 else 1891 gadgetfs_driver.max_speed = USB_SPEED_FULL; 1892 1893 value = usb_gadget_register_driver(&gadgetfs_driver); 1894 if (value != 0) { 1895 spin_lock_irq(&dev->lock); 1896 goto fail; 1897 } else { 1898 /* at this point "good" hardware has for the first time 1899 * let the USB the host see us. alternatively, if users 1900 * unplug/replug that will clear all the error state. 1901 * 1902 * note: everything running before here was guaranteed 1903 * to choke driver model style diagnostics. from here 1904 * on, they can work ... except in cleanup paths that 1905 * kick in after the ep0 descriptor is closed. 1906 */ 1907 value = len; 1908 dev->gadget_registered = true; 1909 } 1910 return value; 1911 1912 fail: 1913 dev->config = NULL; 1914 dev->hs_config = NULL; 1915 dev->dev = NULL; 1916 spin_unlock_irq (&dev->lock); 1917 pr_debug ("%s: %s fail %zd, %p\n", shortname, __func__, value, dev); 1918 kfree (dev->buf); 1919 dev->buf = NULL; 1920 return value; 1921 } 1922 1923 static int 1924 gadget_dev_open (struct inode *inode, struct file *fd) 1925 { 1926 struct dev_data *dev = inode->i_private; 1927 int value = -EBUSY; 1928 1929 spin_lock_irq(&dev->lock); 1930 if (dev->state == STATE_DEV_DISABLED) { 1931 dev->ev_next = 0; 1932 dev->state = STATE_DEV_OPENED; 1933 fd->private_data = dev; 1934 get_dev (dev); 1935 value = 0; 1936 } 1937 spin_unlock_irq(&dev->lock); 1938 return value; 1939 } 1940 1941 static const struct file_operations ep0_operations = { 1942 .llseek = no_llseek, 1943 1944 .open = gadget_dev_open, 1945 .read = ep0_read, 1946 .write = dev_config, 1947 .fasync = ep0_fasync, 1948 .poll = ep0_poll, 1949 .unlocked_ioctl = gadget_dev_ioctl, 1950 .release = dev_release, 1951 }; 1952 1953 /*----------------------------------------------------------------------*/ 1954 1955 /* FILESYSTEM AND SUPERBLOCK OPERATIONS 1956 * 1957 * Mounting the filesystem creates a controller file, used first for 1958 * device configuration then later for event monitoring. 1959 */ 1960 1961 1962 /* FIXME PAM etc could set this security policy without mount options 1963 * if epfiles inherited ownership and permissons from ep0 ... 1964 */ 1965 1966 static unsigned default_uid; 1967 static unsigned default_gid; 1968 static unsigned default_perm = S_IRUSR | S_IWUSR; 1969 1970 module_param (default_uid, uint, 0644); 1971 module_param (default_gid, uint, 0644); 1972 module_param (default_perm, uint, 0644); 1973 1974 1975 static struct inode * 1976 gadgetfs_make_inode (struct super_block *sb, 1977 void *data, const struct file_operations *fops, 1978 int mode) 1979 { 1980 struct inode *inode = new_inode (sb); 1981 1982 if (inode) { 1983 inode->i_ino = get_next_ino(); 1984 inode->i_mode = mode; 1985 inode->i_uid = make_kuid(&init_user_ns, default_uid); 1986 inode->i_gid = make_kgid(&init_user_ns, default_gid); 1987 simple_inode_init_ts(inode); 1988 inode->i_private = data; 1989 inode->i_fop = fops; 1990 } 1991 return inode; 1992 } 1993 1994 /* creates in fs root directory, so non-renamable and non-linkable. 1995 * so inode and dentry are paired, until device reconfig. 1996 */ 1997 static struct dentry * 1998 gadgetfs_create_file (struct super_block *sb, char const *name, 1999 void *data, const struct file_operations *fops) 2000 { 2001 struct dentry *dentry; 2002 struct inode *inode; 2003 2004 dentry = d_alloc_name(sb->s_root, name); 2005 if (!dentry) 2006 return NULL; 2007 2008 inode = gadgetfs_make_inode (sb, data, fops, 2009 S_IFREG | (default_perm & S_IRWXUGO)); 2010 if (!inode) { 2011 dput(dentry); 2012 return NULL; 2013 } 2014 d_add (dentry, inode); 2015 return dentry; 2016 } 2017 2018 static const struct super_operations gadget_fs_operations = { 2019 .statfs = simple_statfs, 2020 .drop_inode = generic_delete_inode, 2021 }; 2022 2023 static int 2024 gadgetfs_fill_super (struct super_block *sb, struct fs_context *fc) 2025 { 2026 struct inode *inode; 2027 struct dev_data *dev; 2028 int rc; 2029 2030 mutex_lock(&sb_mutex); 2031 2032 if (the_device) { 2033 rc = -ESRCH; 2034 goto Done; 2035 } 2036 2037 CHIP = usb_get_gadget_udc_name(); 2038 if (!CHIP) { 2039 rc = -ENODEV; 2040 goto Done; 2041 } 2042 2043 /* superblock */ 2044 sb->s_blocksize = PAGE_SIZE; 2045 sb->s_blocksize_bits = PAGE_SHIFT; 2046 sb->s_magic = GADGETFS_MAGIC; 2047 sb->s_op = &gadget_fs_operations; 2048 sb->s_time_gran = 1; 2049 2050 /* root inode */ 2051 inode = gadgetfs_make_inode (sb, 2052 NULL, &simple_dir_operations, 2053 S_IFDIR | S_IRUGO | S_IXUGO); 2054 if (!inode) 2055 goto Enomem; 2056 inode->i_op = &simple_dir_inode_operations; 2057 if (!(sb->s_root = d_make_root (inode))) 2058 goto Enomem; 2059 2060 /* the ep0 file is named after the controller we expect; 2061 * user mode code can use it for sanity checks, like we do. 2062 */ 2063 dev = dev_new (); 2064 if (!dev) 2065 goto Enomem; 2066 2067 dev->sb = sb; 2068 dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &ep0_operations); 2069 if (!dev->dentry) { 2070 put_dev(dev); 2071 goto Enomem; 2072 } 2073 2074 /* other endpoint files are available after hardware setup, 2075 * from binding to a controller. 2076 */ 2077 the_device = dev; 2078 rc = 0; 2079 goto Done; 2080 2081 Enomem: 2082 kfree(CHIP); 2083 CHIP = NULL; 2084 rc = -ENOMEM; 2085 2086 Done: 2087 mutex_unlock(&sb_mutex); 2088 return rc; 2089 } 2090 2091 /* "mount -t gadgetfs path /dev/gadget" ends up here */ 2092 static int gadgetfs_get_tree(struct fs_context *fc) 2093 { 2094 return get_tree_single(fc, gadgetfs_fill_super); 2095 } 2096 2097 static const struct fs_context_operations gadgetfs_context_ops = { 2098 .get_tree = gadgetfs_get_tree, 2099 }; 2100 2101 static int gadgetfs_init_fs_context(struct fs_context *fc) 2102 { 2103 fc->ops = &gadgetfs_context_ops; 2104 return 0; 2105 } 2106 2107 static void 2108 gadgetfs_kill_sb (struct super_block *sb) 2109 { 2110 mutex_lock(&sb_mutex); 2111 kill_litter_super (sb); 2112 if (the_device) { 2113 put_dev (the_device); 2114 the_device = NULL; 2115 } 2116 kfree(CHIP); 2117 CHIP = NULL; 2118 mutex_unlock(&sb_mutex); 2119 } 2120 2121 /*----------------------------------------------------------------------*/ 2122 2123 static struct file_system_type gadgetfs_type = { 2124 .owner = THIS_MODULE, 2125 .name = shortname, 2126 .init_fs_context = gadgetfs_init_fs_context, 2127 .kill_sb = gadgetfs_kill_sb, 2128 }; 2129 MODULE_ALIAS_FS("gadgetfs"); 2130 2131 /*----------------------------------------------------------------------*/ 2132 2133 static int __init gadgetfs_init (void) 2134 { 2135 int status; 2136 2137 status = register_filesystem (&gadgetfs_type); 2138 if (status == 0) 2139 pr_info ("%s: %s, version " DRIVER_VERSION "\n", 2140 shortname, driver_desc); 2141 return status; 2142 } 2143 module_init (gadgetfs_init); 2144 2145 static void __exit gadgetfs_cleanup (void) 2146 { 2147 pr_debug ("unregister %s\n", shortname); 2148 unregister_filesystem (&gadgetfs_type); 2149 } 2150 module_exit (gadgetfs_cleanup); 2151 2152